Glossary of engineering: A–L
From KYNNpedia
This glossary of engineering terms is a list of definitions about the major concepts of engineering. Please see the bottom of the page for glossaries of specific fields of engineering.
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A
- Absolute electrode potential
- In electrochemistry, according to an IUPAC definition,<ref>IUPAC Gold Book – absolute electrode potential</ref> is the electrode potential of a metal measured with respect to a universal reference system (without any additional metal–solution interface).
- Absolute pressure
- Is zero-referenced against a perfect vacuum, using an absolute scale, so it is equal to gauge pressure plus atmospheric pressure.
- Absolute zero
- The lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as 0. Absolute zero is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as −273.15° on the Celsius scale (International System of Units),<ref name=sib2115>"Unit of thermodynamic temperature (kelvin)". SI Brochure, 8th edition. Bureau International des Poids et Mesures. 13 March 2010 [1967]. Section 2.1.1.5. Archived from the original on 7 October 2014. Retrieved 20 June 2017. Note: The triple point of water is 0.01 °C, not 0 °C; thus 0 K is −273.15 °C, not −273.16 °C.</ref><ref name="arora">Arora, C. P. (2001). Thermodynamics. Tata McGraw-Hill. Table 2.4 page 43. ISBN 978-0-07-462014-4.</ref> which equals −459.67° on the Fahrenheit scale (United States customary units or Imperial units).<ref>Zielinski, Sarah (1 January 2008). "Absolute Zero". Smithsonian Institution. Archived from the original on 2013-04-01. Retrieved 2012-01-26.</ref> The corresponding Kelvin and Rankine temperature scales set their zero points at absolute zero by definition.
- Absorbance
- Absorbance or decadic absorbance is the common logarithm of the ratio of incident to transmitted radiant power through a material, and spectral absorbance or spectral decadic absorbance is the common logarithm of the ratio of incident to transmitted spectral radiant power through a material.<ref name=GoldBook>IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Absorbance". doi:10.1351/goldbook.A00028</ref>
- AC power
- Electric power delivered by alternating current; common household power is AC.
- Acceleration
- The rate at which the velocity of a body changes with time, and the direction in which that change is acting.
- Acid
- A molecule or ion capable of donating a hydron (proton or hydrogen ion H+), or, alternatively, capable of forming a covalent bond with an electron pair (a Lewis acid).<ref name="IUPAC_acid">IUPAC Gold Book – acid</ref>
- Acid–base reaction
- A chemical reaction that occurs between an acid and a base, which can be used to determine pH.
- Acid strength
- In strong acids, most of the molecules give up a hydrogen ion and become ionized.
- Acoustics
- The scientific study of sound.
- Activated sludge
- A type of wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa.
- Activated sludge model
- A generic name for a group of mathematical methods to model activated sludge systems.
- Active transport
- In cellular biology, active transport is the movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses ATP, and secondary active transport that uses an electrochemical gradient. An example of active transport in human physiology is the uptake of glucose in the intestines.
- Actuator
- A device that accepts 2 inputs (control signal, energy source) and outputs kinetic energy in the form of physical movement (linear, rotary, or oscillatory). The control signal input specifies which motion should be taken. The energy source input is typically either an electric current, hydraulic pressure, or pneumatic pressure. An actuator can be the final element of a control loop
- Adenosine triphosphate
- A complex organic chemical that provides energy to drive many processes in living cells, e.g. muscle contraction, nerve impulse propagation, chemical synthesis. Found in all forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer.<ref>Knowles, J. R. (1980). "Enzyme-catalyzed phosphoryl transfer reactions". Annu. Rev. Biochem. 49: 877–919. doi:10.1146/annurev.bi.49.070180.004305. PMID 6250450.</ref>
- Adhesion
- The tendency of dissimilar particles or surfaces to cling to one another (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another).
- Adiabatic process
- A process where no heat energy is lost to outside space.
- Adiabatic wall
- A barrier through which heat energy cannot pass.
- Aerobic digestion
- A process in sewage treatment designed to reduce the volume of sewage sludge and make it suitable<ref name="WEF">"Aerobic Diestion" (PDF). Water Environment Federation. Archived from the original (PDF) on 27 March 2016. Retrieved 19 March 2016.</ref> for subsequent use.<ref name="Handbook">"Handbook Biological Wastewater Treatment - Design of Activated Sludge Systems". Retrieved 19 March 2016.</ref>
- Aerodynamics
- The study of the motion of air, particularly its interaction with a solid object, such as an airplane wing. It is a sub-field of fluid dynamics and gas dynamics, and many aspects of aerodynamics theory are common to these fields.
- Aerospace engineering
- Is the primary field of engineering concerned with the development of aircraft and spacecraft.<ref>Encyclopedia of Aerospace Engineering. John Wiley & Sons, 2010. ISBN 978-0-470-75440-5.</ref> It has two major and overlapping branches: Aeronautical engineering and Astronautical Engineering. Avionics engineering is similar, but deals with the electronics side of aerospace engineering.
- Afocal system
- An optical system that produces no net convergence or divergence of the beam, i.e. has an infinite effective focal length.<ref>Daniel Malacara, Zacarias Malacara, Handbook of optical design. Page 379</ref>
- Agricultural engineering
- The profession of designing machinery, processes, and systems for use in agriculture.
- Albedo
- A measure of the fraction of light reflected from an astronomical body or other object.
- Alkane
- An alkane, or paraffin (a historical name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single.<ref name="goldbook-alkanes">"Alkanes". IUPAC Gold Book - alkanes. IUPAC. March 27, 2017. doi:10.1351/goldbook.A00222. ISBN 978-0-9678550-9-7. Retrieved 2018-08-23.</ref>
- Alkene
- An unsaturated hydrocarbon that contains at least one carbon–carbon double bond.<ref name="Wade">Wade, L.G. (2006). Organic Chemistry (6th ed.). Pearson Prentice Hall. p. 279. ISBN 978-1-4058-5345-3.</ref> The words alkene and olefin are often used interchangeably.
- Alkyne
- Is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond.<ref>Alkyne. Encyclopædia Britannica</ref> The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula CnH2n−2.
- Alloy
- is a combination of metals or of a metal and another element. Alloys are defined by a metallic bonding character.<ref>Callister, W. D. "Materials Science and Engineering: An Introduction" 2007, 7th edition, John Wiley and Sons, Inc. New York, Section 4.3 and Chapter 9.</ref>
- Alpha particle
- Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.
- Alternating current
- Electrical current that regularly reverses direction.
- Alternative hypothesis
- In statistical hypothesis testing, the alternative hypothesis (or maintained hypothesis or research hypothesis) and the null hypothesis are the two rival hypotheses which are compared by a statistical hypothesis test. In the domain of science two rival hypotheses can be compared by explanatory power and predictive power.
- Ammeter
- An instrument that measures current.
- Amino acids
- Are organic compounds containing amine (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid.<ref>"Amino". Dictionary.com. 2015. Retrieved 3 July 2015.</ref><ref>"amino acid". Cambridge Dictionaries Online. Cambridge University Press. 2015. Retrieved 3 July 2015.</ref><ref>"amino". FreeDictionary.com. Farlex. 2015. Retrieved 3 July 2015.</ref> The key elements of an amino acid are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), although other elements are found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known (though only 20 appear in the genetic code) and can be classified in many ways.<ref>Wagner I, Musso H (November 1983). "New Naturally Occurring Amino Acids". Angewandte Chemie International Edition in English. 22 (11): 816–28. doi:10.1002/anie.198308161.
</ref> - Amorphous solid
- An amorphous (from the Greek a, without, morphé, shape, form) or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal.
- Ampere
- The SI unit of current flow, one coulomb per second.
- Amphoterism
- In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid as well as a base.<ref>IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "amphoteric". doi:10.1351/goldbook.A00306</ref> Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation states of the oxide. Al2O3 is an example of an amphoteric oxide.
- Amplifier
- A device that replicates a signal with increased power.
- Amplitude
- The amplitude of a periodic variable is a measure of its change over a single period (such as time or spatial period). There are various definitions of amplitude, which are all functions of the magnitude of the difference between the variable's extreme values. In older texts the phase is sometimes called the amplitude.<ref>Knopp, Konrad; Bagemihl, Frederick (1996). Theory of Functions Parts I and II. Dover Publications. p. 3. ISBN 978-0-486-69219-7.</ref>
- Anaerobic digestion
- Is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen.<ref name="nnfcc">National Non-Food Crops Centre. "NNFCC Renewable Fuels and Energy Factsheet: Anaerobic Digestion", Retrieved on 2011-11-22</ref> The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.
- Angular acceleration
- Is the rate of change of angular velocity. In three dimensions, it is a pseudovector. In SI units, it is measured in radians per second squared (rad/s2), and is usually denoted by the Greek letter alpha (α).<ref>"Angular Velocity and Acceleration". Theory.uwinnipeg.ca. Archived from the original on 2012-02-22. Retrieved 2015-04-13.</ref>
- Angular momentum
- In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum. It is an important quantity in physics because it is a conserved quantity—the total angular momentum of a system remains constant unless acted on by an external torque.
- Angular velocity
- In physics, the angular velocity of a particle is the rate at which it rotates around a chosen center point: that is, the time rate of change of its angular displacement relative to the origin (i.e. in layman's terms: how quickly an object goes around something over a period of time - e.g. how fast the earth orbits the sun). It is measured in angle per unit time, radians per second in SI units, and is usually represented by the symbol omega (ω, sometimes Ω). By convention, positive angular velocity indicates counter-clockwise rotation, while negative is clockwise.
- Anion
- Is an ion with more electrons than protons, giving it a net negative charge (since electrons are negatively charged and protons are positively charged).<ref>University of Colorado Boulder (November 21, 2013). "Atoms and Elements, Isotopes and Ions". colorado.edu. Archived from the original on May 13, 2021. Retrieved November 4, 2018.</ref>
- Annealing (metallurgy)
- A heat treatment process that relieves internal stresses.
- Annihilation
- In particle physics, annihilation is the process that occurs when a subatomic particle collides with its respective antiparticle to produce other particles, such as an electron colliding with a positron to produce two photons.<ref> "Antimatter". Lawrence Berkeley National Laboratory. Archived from the original on 23 August 2008. Retrieved 3 September 2008.</ref> The total energy and momentum of the initial pair are conserved in the process and distributed among a set of other particles in the final state. Antiparticles have exactly opposite additive quantum numbers from particles, so the sums of all quantum numbers of such an original pair are zero. Hence, any set of particles may be produced whose total quantum numbers are also zero as long as conservation of energy and conservation of momentum are obeyed.<ref name=Particleadventure.org> "The Standard Model – Particle decays and annihilations". The Particle Adventure: The Fundamentals of Matter and Force. Lawrence Berkeley National Laboratory. Retrieved 17 October 2011.</ref>
- Anode
- The electrode at which current enters a device such as an electrochemical cell or vacuum tube.
- ANSI
- The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.<ref>RFC 4949</ref> The organization also coordinates U.S. standards with international standards so that American products can be used worldwide.
- Anti-gravity
- Anti-gravity (also known as non-gravitational field) is a theory of creating a place or object that is free from the force of gravity. It does not refer to the lack of weight under gravity experienced in free fall or orbit, or to balancing the force of gravity with some other force, such as electromagnetism or aerodynamic lift.
- Applied engineering
- Is the field concerned with the application of management, design, and technical skills for the design and integration of systems, the execution of new product designs, the improvement of manufacturing processes, and the management and direction of physical and/or technical functions of a firm or organization. Applied-engineering degreed programs typically include instruction in basic engineering principles, project management, industrial processes, production and operations management, systems integration and control, quality control, and statistics.<ref>"ATMAE Venn Diagram". Archived from the original on 2017-06-30. Retrieved 2018-11-15.</ref>
- Applied mathematics
- Mathematics used for solutions of practical problems, as opposed to pure mathematics.
- Arc length
- Arc length is the distance between two points along a section of a curve. Determining the length of an irregular arc segment is also called rectification of a curve. The advent of infinitesimal calculus led to a general formula that provides closed-form solutions in some cases.
- Archimedes' principle
- States that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid.<ref>"What is buoyant force?".</ref> Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse<ref name="acottLaw">Acott, Chris (1999). "The diving "Law-ers": A brief resume of their lives". South Pacific Underwater Medicine Society Journal. 29 (1). ISSN 0813-1988. OCLC 16986801. Archived from the original on 2011-07-27. Retrieved 2009-06-13.
{{cite journal}}: CS1 maint: unfit URL (link)</ref> - Area moment of inertia
- The 2nd moment of area, also known as moment of inertia of plane area, area moment of inertia, or second area moment, is a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis. The second moment of area is typically denoted with either an <math>I</math> for an axis that lies in the plane or with a <math>J</math> for an axis perpendicular to the plane. In both cases, it is calculated with a multiple integral over the object in question. Its dimension is L (length) to the fourth power. Its unit of dimension when working with the International System of Units is meters to the fourth power, m4.
- Arithmetic mean
- In mathematics and statistics, the arithmetic mean or simply the mean or average when the context is clear, is the sum of a collection of numbers divided by the number of numbers in the collection.<ref>Jacobs, Harold R. (1994). Mathematics: A Human Endeavor (Third ed.). W. H. Freeman. p. 547. ISBN 978-0-7167-2426-1.</ref>
- Arithmetic progression
- In mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. Difference here means the second minus the first. For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with common difference of 2.
- Aromatic hydrocarbon
- An aromatic hydrocarbon or arene<ref>IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "arenes". doi:10.1351/goldbook.A00435</ref> (or sometimes aryl hydrocarbon)<ref>Mechanisms of Activation of the Aryl Hydrocarbon Receptor by Maria Backlund, Institute of Environmental Medicine, Karolinska Institutet.</ref> is a hydrocarbon with sigma bonds and delocalized pi electrons between carbon atoms forming a circle. In contrast, aliphatic hydrocarbons lack this delocalization. The term "aromatic" was assigned before the physical mechanism determining aromaticity was discovered; the term was coined as such simply because many of the compounds have a sweet or pleasant odour. The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible such hydrocarbon, benzene. Aromatic hydrocarbons can be monocyclic (MAH) or polycyclic (PAH).
- Arrhenius equation
- The Arrhenius equation is a formula for the temperature dependence of reaction rates. The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that Van 't Hoff's equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and reverse reactions. This equation has a vast and important application in determining rate of chemical reactions and for calculation of energy of activation. Arrhenius provided a physical justification and interpretation for the formula.<ref name="Arrhenius96">Arrhenius, S.A. (1889). "Über die Dissociationswärme und den Einfluß der Temperatur auf den Dissociationsgrad der Elektrolyte". Z. Phys. Chem. 4: 96–116. doi:10.1515/zpch-1889-0408. S2CID 202553486.</ref><ref name="Arrhenius226">Arrhenius, S.A. (1889). "Über die Reaktionsgeschwindigkeit bei der Inversion von Rohrzucker durch Säuren". ibid. 4: 226–248.</ref><ref name="Laidler42">Laidler, K. J. (1987) Chemical Kinetics, Third Edition, Harper & Row, p.42</ref> Currently, it is best seen as an empirical relationship.<ref name="Connors">Kenneth Connors, Chemical Kinetics, 1990, VCH Publishers Chemical Kinetics: The Study of Reaction Rates in Solution at Google Books</ref>: 188 It can be used to model the temperature variation of diffusion coefficients, population of crystal vacancies, creep rates, and many other thermally-induced processes/reactions. The Eyring equation, developed in 1935, also expresses the relationship between rate and energy.
- Artificial intelligence
- (AI), is intelligence demonstrated by machines, unlike the natural intelligence displayed by humans and animals. Leading AI textbooks define the field as the study of "intelligent agents": any device that perceives its environment and takes actions that maximize its chance of successfully achieving its goals.<ref name="Definition of AI" group="">Definition of AI as the study of intelligent agents:
- Poole, Mackworth & Goebel (1998), which provides the version that is used in this article. These authors use the term "computational intelligence" as a synonym for artificial intelligence.<ref name="FOOTNOTEPooleMackworthGoebel1998[httppeoplecsubcca~poolecich1pdf p. 1]">Poole, Mackworth & Goebel 1998, p. 1.</ref>
- Russell & Norvig (2003) (who prefer the term "rational agent") and write "The whole-agent view is now widely accepted in the field".<ref name="FOOTNOTERussellNorvig200355">Russell & Norvig 2003, p. 55.</ref>
- Nilsson 1998
- Legg & Hutter 2007</ref> Colloquially, the term "artificial intelligence" is often used to describe machines (or computers) that mimic "cognitive" functions that humans associate with the human mind, such as "learning" and "problem solving".<ref name="FOOTNOTERussellNorvig20092">Russell & Norvig 2009, p. 2.</ref>
- Assembly language
- A computer programming language where most statements correspond to one or a few machine op-codes.
- Atomic orbital
- In atomic theory and quantum mechanics, an atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom.<ref>Orchin, Milton; Macomber, Roger S.; Pinhas, Allan; Wilson, R. Marshall (2005). Atomic Orbital Theory (PDF).</ref> This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term atomic orbital may also refer to the physical region or space where the electron can be calculated to be present, as defined by the particular mathematical form of the orbital.<ref>Daintith, J. (2004). Oxford Dictionary of Chemistry. New York: Oxford University Press. ISBN 978-0-19-860918-6.</ref>
- Atomic packing factor
- The percentage of the volume filled with atomic mass in a crystal formation.
- Audio frequency
- An audio frequency (abbreviation: AF), or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human. The SI unit of audio frequency is the hertz (Hz). It is the property of sound that most determines pitch.<ref>Pilhofer, Michael (2007). Music Theory for Dummies. For Dummies. p. 97. ISBN 978-0-470-16794-6.</ref>
- Austenitization
- Austenitization means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite.<ref>Nichols R (Jul 2001). "Quenching and tempering of welded carbon steel tubulars".</ref> The more open structure of the austenite is then able to absorb carbon from the iron-carbides in carbon steel. An incomplete initial austenitization can leave undissolved carbides in the matrix.<ref name=Lambers>Lambers HG, Tschumak S, Maier HJ, Canadinc D (Apr 2009). "Role of Austenitization and Pre-Deformation on the Kinetics of the Isothermal Bainitic Transformation". Metall. Mater. Trans. A. 40 (6): 1355–1366. Bibcode:2009MMTA...40.1355L. doi:10.1007/s11661-009-9827-z. S2CID 136882327.</ref> For some irons, iron-based metals, and steels, the presence of carbides may occur during the austenitization step. The term commonly used for this is two-phase austenitization.<ref name=smnm>"Austenitization".</ref>
- Automation
- Is the technology by which a process or procedure is performed with minimum human assistance.<ref>Groover, Mikell (2014). Fundamentals of Modern Manufacturing: Materials, Processes, and Systems.</ref> Automation<ref name="Rifkin 1995">Rifkin, Jeremy (1995). The End of Work: The Decline of the Global Labor Force and the Dawn of the Post-Market Era. Putnam Publishing Group. pp. 66, 75. ISBN 978-0-87477-779-6.</ref> or automatic control is the use of various control systems for operating equipment such as machinery, processes in factories, boilers and heat treating ovens, switching on telephone networks, steering and stabilization of ships, aircraft and other applications and vehicles with minimal or reduced human intervention. Some processes have been completely automated.
- Autonomous vehicle
- A vehicle capable of driving from one point to another without input from a human operator.
- Azimuthal quantum number
- The azimuthal quantum number is a quantum number for an atomic orbital that determines its orbital angular momentum and describes the shape of the orbital. The azimuthal quantum number is the second of a set of quantum numbers which describe the unique quantum state of an electron (the others being the principal quantum number, following spectroscopic notation, the magnetic quantum number, and the spin quantum number). It is also known as the orbital angular momentum quantum number, orbital quantum number or second quantum number, and is symbolized as ℓ.
B
- Barometer
- A device for measuring pressure.
- Battery
- Electrochemical cells that transform chemical energy into electricity.
- Base
- In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH−) ions, are slippery to the touch, can taste bitter if an alkali,<ref>Johll, Matthew E. (2009). Investigating chemistry: a forensic science perspective (2nd ed.). New York: W. H. Freeman and Co. ISBN 978-1-4292-0989-2. OCLC 392223218.</ref> change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor, and/or contain completely or partially displaceable OH− ions.
- Baud
- Rate at which data is transferred in symbols/second; a symbol may represent one or more bits.
- Beam
- A structural element whose length is significantly greater than its width or height.
- Beer–Lambert law
- The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law relates the attenuation of light to the properties of the material through which the light is travelling. The law is commonly applied to chemical analysis measurements and used in understanding attenuation in physical optics, for photons, neutrons or rarefied gases. In mathematical physics, this law arises as a solution of the BGK equation.
- Belt
- A closed loop of flexible material used to transmit mechanical power from one pulley to another.
- Belt friction
- Is a term describing the friction forces between a belt and a surface, such as a belt wrapped around a bollard. When one end of the belt is being pulled only part of this force is transmitted to the other end wrapped about a surface. The friction force increases with the amount of wrap about a surface and makes it so the tension in the belt can be different at both ends of the belt. Belt friction can be modeled by the Belt friction equation.<ref name=Attaway>Attaway, Stephen W. (1999). The Mechanics of Friction in Rope Rescue (PDF). International Technical Rescue Symposium. Retrieved February 1, 2010.</ref>
- Bending
- In applied mechanics, bending (also known as flexure) characterizes the behavior of a slender structural element subjected to an external load applied perpendicularly to a longitudinal axis of the element. The structural element is assumed to be such that at least one of its dimensions is a small fraction, typically 1/10 or less, of the other two.<ref name=Boresi>Boresi, A. P. and Schmidt, R. J. and Sidebottom, O. M., 1993, Advanced mechanics of materials, John Wiley and Sons, New York.</ref>
- Bending moment
- In solid mechanics, a bending moment is the reaction induced in a structural element when an external force or moment is applied to the element, causing the element to bend.<ref name=timo>Gere, J.M.; Timoshenko, S.P. (1996), Mechanics of Materials:Forth edition, Nelson Engineering, ISBN 0-534-93429-3</ref> <ref name=beer>Beer, F.; Johnston, E.R. (1984), Vector mechanics for engineers: statics, McGraw Hill, pp. 62–76</ref> The most common or simplest structural element subjected to bending moments is the beam.
- Benefit–cost analysis
- Cost–benefit analysis (CBA), sometimes called benefit costs analysis (BCA), is a systematic approach to estimating the strengths and weaknesses of alternatives (for example in transactions, activities, functional business requirements); it is used to determine options that provide the best approach to achieve benefits while preserving savings.<ref>David, Rodreck; Ngulube, Patrick; Dube, Adock (16 July 2013). "A cost–benefit analysis of document management strategies used at a financial institution in Zimbabwe: A case study". SA Journal of Information Management. 15 (2). doi:10.4102/sajim.v15i2.540.</ref> It may be used to compare potential (or completed) courses of actions; or estimate (or evaluate) the value against costs of a single decision, project, or policy.
- Bernoulli differential equation
- In mathematics, an ordinary differential equation of the form:
- <math>y'+ P(x)y = Q(x)y^n\,</math>
- Bernoulli's equation
- An equation for relating several measurements within a fluid flow, such as velocity, pressure, and potential energy.
- Bernoulli's principle
- In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.<ref name="Clancy1975">Clancy, L. J. (1975). Aerodynamics. Wiley. ISBN 978-0-470-15837-1.</ref>: Ch.3 <ref name="Batchelor2000">Batchelor, G. K. (2000). An Introduction to Fluid Dynamics. Cambridge: University Press. ISBN 978-0-521-66396-0.</ref>: 156–164, § 3.5 The principle is named after Daniel Bernoulli who published it in his book Hydrodynamica in 1738.<ref>"Hydrodynamica". Britannica Online Encyclopedia. Retrieved 2008-10-30.</ref> Although Bernoulli deduced that pressure decreases when the flow speed increases, it was Leonhard Euler who derived Bernoulli's equation in its usual form in 1752.<ref name="Anderson2016">Anderson, J.D. (2016), "Some reflections on the history of fluid dynamics", in Johnson, R.W. (ed.), Handbook of fluid dynamics (2nd ed.), CRC Press, ISBN 978-1-4398-4957-6</ref><ref>Darrigol, O.; Frisch, U. (2008), "From Newton's mechanics to Euler's equations", Physica D: Nonlinear Phenomena, 237 (14–17): 1855–1869, Bibcode:2008PhyD..237.1855D, doi:10.1016/j.physd.2007.08.003</ref> The principle is only applicable for isentropic flows: when the effects of irreversible processes (like turbulence) and non-adiabatic processes (e.g. heat radiation) are small and can be neglected.
- Beta particle
- also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β− decay and β+ decay, which produce electrons and positrons respectively.<ref>Lawrence Berkeley National Laboratory (9 August 2000). "Beta Decay". Nuclear Wall Chart. United States Department of Energy. Archived from the original on 24 March 2020. Retrieved 17 January 2016.</ref>
- Binomial distribution
- In probability theory and statistics, the binomial distribution with parameters n and p is the discrete probability distribution of the number of successes in a sequence of n independent experiments, each asking a yes–no question, and each with its own boolean-valued outcome: a random variable containing a single bit of information: success/yes/true/one (with probability p) or failure/no/false/zero (with probability q = 1 − p). A single success/failure experiment is also called a Bernoulli trial or Bernoulli experiment and a sequence of outcomes is called a Bernoulli process; for a single trial, i.e., n = 1, the binomial distribution is a Bernoulli distribution. The binomial distribution is the basis for the popular binomial test of statistical significance.
- Biocatalysis
- Biocatalysis refers to the use of living (biological) systems or their parts to speed up (catalyze) chemical reactions. In biocatalytic processes, natural catalysts, such as enzymes, perform chemical transformations on organic compounds. Both enzymes that have been more or less isolated and enzymes still residing inside living cells are employed for this task.<ref>Anthonsen, Thorlief (2000). "Reactions Catalyzed by Enzymes". In Adlercreutz, Patrick; Straathof, Adrie J. J. (eds.). Applied Biocatalysis (2nd ed.). Taylor & Francis. pp. 18–59. ISBN 978-90-5823-024-9. Retrieved 9 February 2013.</ref><ref>Faber, Kurt (2011). Biotransformations in Organic Chemistry (6th ed.). Springer. ISBN 978-3-642-17393-6.[page needed]</ref><ref>Jayasinghe, Leonard Y.; Smallridge, Andrew J.; Trewhella, Maurie A. (1993). "The yeast mediated reduction of ethyl acetoacetate in petroleum ether". Tetrahedron Letters. 34 (24): 3949–3950. doi:10.1016/S0040-4039(00)79272-0.</ref> The modern usage of biotechnologically produced and possibly modified enzymes for organic synthesis is termed chemoenzymatic synthesis; the reactions performed are chemoenzymatic reactions.
- Biomedical engineering
- Biomedical Engineering (BME) or Medical Engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes (e.g. diagnostic or therapeutic). This field seeks to close the gap between engineering and medicine, combining the design and problem solving skills of engineering with medical biological sciences to advance health care treatment, including diagnosis, monitoring, and therapy.<ref name="EnderleBronzino2012">John Denis Enderle; Joseph D. Bronzino (2012). Introduction to Biomedical Engineering. Academic Press. pp. 16–. ISBN 978-0-12-374979-6.</ref>
- Biomimetic
- Biomimetics or biomimicry is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems.<ref>Vincent, Julian F. V.; et al. (22 August 2006). "Biomimetics: its practice and theory". Journal of the Royal Society Interface. 3 (9): 471–482. doi:10.1098/rsif.2006.0127. PMC 1664643. PMID 16849244.</ref>
- Bionics
- The application of biological methods to engineering systems.
- Biophysics
- Is an interdisciplinary science that applies approaches and methods traditionally used in physics to study biological phenomena.<ref>"Biophysics | science". Encyclopædia Britannica. Retrieved 2018-07-26.</ref><ref>Zhou HX (March 2011). "Q&A: What is biophysics?". BMC Biology. 9: 13. doi:10.1186/1741-7007-9-13. PMC 3055214. PMID 21371342.</ref><ref>"the definition of biophysics". www.dictionary.com. Retrieved 2018-07-26.</ref> Biophysics covers all scales of biological organization, from molecular to organismic and populations. Biophysical research shares significant overlap with biochemistry, molecular biology, physical chemistry, physiology, nanotechnology, bioengineering, computational biology, biomechanics and systems biology.
- Biot number
- The Biot number (Bi) is a dimensionless quantity used in heat transfer calculations. It is named after the eighteenth century French physicist Jean-Baptiste Biot (1774–1862), and gives a simple index of the ratio of the heat transfer resistances inside of and at the surface of a body. This ratio determines whether or not the temperatures inside a body will vary significantly in space, while the body heats or cools over time, from a thermal gradient applied to its surface.
- Block and tackle
- A system of pulleys and a rope threaded between them, used to lift or pull heavy loads.
- Body force
- Is a force that acts throughout the volume of a body. Forces due to gravity, electric fields and magnetic fields are examples of body forces. Body forces contrast with contact forces or surface forces which are exerted to the surface of an object.
- Boiler
- Is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications,<ref>Frederick M. Steingress (2001). Low Pressure Boilers (4th ed.). American Technical Publishers. ISBN 0-8269-4417-5.</ref><ref>Frederick M. Steingress, Harold J. Frost and Darryl R. Walker (2003). High Pressure Boilers (3rd ed.). American Technical Publishers. ISBN 0-8269-4300-4.</ref> including water heating, central heating, boiler-based power generation, cooking, and sanitation.
- Boiling point
- The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid<ref>Goldberg, David E. (1988). 3,000 Solved Problems in Chemistry (1st ed.). McGraw-Hill. section 17.43, p. 321. ISBN 0-07-023684-4.</ref><ref>Theodore, Louis; Dupont, R. Ryan; Ganesan, Kumar, eds. (1999). Pollution Prevention: The Waste Management Approach to the 21st Century. CRC Press. section 27, p. 15. ISBN 1-56670-495-2.</ref> and the liquid changes into a vapor.
- Boiling-point elevation
- Boiling-point elevation describes the phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as water. The boiling point can be measured accurately using an ebullioscope.
- Boltzmann constant
- The Boltzmann constant (kB or k) is a physical constant relating the average kinetic energy of particles in a gas with the temperature of the gas<ref name=Feynman1Ch39-10>Richard Feynman (1970). The Feynman Lectures on Physics Vol I. Addison Wesley Longman. ISBN 978-0-201-02115-8.</ref> and occurs in Planck's law of black-body radiation and in Boltzmann's entropy formula. It was introduced by Max Planck, but named after Ludwig Boltzmann.
It is the gas constant R divided by the Avogadro constant NA:
- <math> k = \frac{R}{N_\text{A .</math>.}}
... boson: A force-carrying particle, as opposed to a matter particle (fermion). Bosons can be piled on top of each other without limit. Examples include photons, gluons, gravitons, weak bosons, and the Higgs boson. The spin of a boson is always an integer, such as 0, 1, 2, and so on ...</ref> The name boson was coined by Paul Dirac<ref>Notes on Dirac's lecture Developments in Atomic Theory at Le Palais de la Découverte, 6 December 1945. UKNATARCHI Dirac Papers. BW83/2/257889.</ref><ref>Farmelo, Graham (2009-08-25). The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom. Basic Books. p. 331. ISBN 978-0-465-01992-2.</ref> to commemorate the contribution of Indian physicist and professor of physics at University of Calcutta and at University of Dhaka, Satyendra Nath Bose<ref name="AP-20120710">Daigle, Katy (10 July 2012). "India: Enough about Higgs, let's discuss the boson". AP News. Retrieved 10 July 2012.</ref><ref name="NYT-20120919">Bal, Hartosh Singh (19 September 2012). "The Bose in the Boson". The New York Times blog. Retrieved 21 September 2012.</ref> in developing, with Albert Einstein, Bose–Einstein statistics—which theorizes the characteristics of elementary particles.<ref>"Higgs boson: The poetry of subatomic particles". BBC News. 4 July 2012. Retrieved 6 July 2012.</ref>
draper, john william.</ref>) is an experimental gas law that describes how the pressure of a gas tends to increase as the volume of the container decreases. A modern statement of Boyle's law is: The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system.<ref>Levine, Ira. N (1978). "Physical Chemistry" University of Brooklyn: McGraw-Hill</ref><ref name="levine_1">Levine, Ira. N. (1978), p. 12 gives the original definition.</ref>
- <math>\mathbf{R} = n_{1}\mathbf{a}_{1} + n_{2}\mathbf{a}_{2} + n_{3}\mathbf{a}_{3}</math>
C
- Calculus
- The mathematics of change.
- Capacitance
- The ability of a body to store electrical charge.
- Capacitive reactance
- The impedance of a capacitor in an alternating current circuit, the opposition to current flow.
- Capacitor
- An electrical component that stores energy in an electric field.
- Capillary action
- Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paintbrush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.
- Carbonate
- Any mineral with bound carbon dioxide.
- Carnot cycle
- A hypothetical thermodynamic cycle for a heat engine; no thermodynamic cycle can be more efficient than a Carnot cycle operating between the same two temperature limits.
- Cartesian coordinates
- Coordinates within a rectangular Cartesian plane.
- Castigliano's method
- Named for Carlo Alberto Castigliano, is a method for determining the displacements of a linear-elastic system based on the partial derivatives of the energy. He is known for his two theorems. The basic concept may be easy to understand by recalling that a change in energy is equal to the causing force times the resulting displacement. Therefore, the causing force is equal to the change in energy divided by the resulting displacement. Alternatively, the resulting displacement is equal to the change in energy divided by the causing force. Partial derivatives are needed to relate causing forces and resulting displacements to the change in energy.
- Casting
- Forming of an object by pouring molten metal (or other substances) into a mold.
- Cathode
- The terminal of a device by which current exits.
- Cathode ray
- The stream of electrons emitted from a heated negative electrode and attracted to a positive electrode.
- Cell membrane
- The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates the interior of all cells from the outside environment (the extracellular space) which protects the cell from its environment<ref>Kimball's Biology pages Archived 2009-01-25 at the Wayback Machine, Cell Membranes</ref><ref>Singleton P (1999). Bacteria in Biology, Biotechnology and Medicine (5th ed.). New York: Wiley. ISBN 978-0-471-98880-9.</ref> consisting of a lipid bilayer with embedded proteins.
- Cell nucleus
- In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel or seed) is a membrane-enclosed organelle found in eukaryotic cells. Eukaryotes usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.
- Cell theory
- In biology, cell theory is the historic scientific theory, now universally accepted, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
- Center of gravity
- The center of mass of an object, its balance point.
- Center of mass
- The weighted center of an object; a force applied through the center of mass will not cause rotation of the object.
- Center of pressure
- Is the point where the total sum of a pressure field acts on a body, causing a force to act through that point. The total force vector acting at the center of pressure is the value of the integrated vectorial pressure field. The resultant force and center of pressure location produce equivalent force and moment on the body as the original pressure field.
- Central force motion
- .
- Central limit theorem
- In probability theory, the central limit theorem (CLT) establishes that, in some situations, when independent random variables are added, their properly normalized sum tends toward a normal distribution (informally a "bell curve") even if the original variables themselves are not normally distributed. The theorem is a key concept in probability theory because it implies that probabilistic and statistical methods that work for normal distributions can be applicable to many problems involving other types of distributions.
- Central processing unit
- A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logic, controlling and input/output (I/O) operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s.<ref name="weik1961">Weik, Martin H. (1961). "A Third Survey of Domestic Electronic Digital Computing Systems". Ballistic Research Laboratory.</ref> Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.<ref name="kuck">Kuck, David (1978). Computers and Computations, Vol 1. John Wiley & Sons, Inc. p. 12. ISBN 978-0-471-02716-4.</ref>
- Centripetal acceleration
- .
- Centripetal force
- A force acting against rotational acceleration.
- Centroid
- The average point of volume for an object.
- Centrosome
- In cell biology, the centrosome is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell-cycle progression. The centrosome is thought to have evolved only in the metazoan lineage of eukaryotic cells.<ref name="pmid17977464">Bornens, M.; Azimzadeh, J. (2007). "Origin and Evolution of the Centrosome". Eukaryotic Membranes and Cytoskeleton. Advances in Experimental Medicine and Biology. Vol. 607. pp. 119–129. doi:10.1007/978-0-387-74021-8_10. ISBN 978-0-387-74020-1. PMID 17977464.</ref> Fungi and plants lack centrosomes and therefore use structures other than MTOCs to organize their microtubules.<ref name="pmid12224551">Schmit (2002). Acentrosomal microtubule nucleation in higher plants. International Review of Cytology. Vol. 220. pp. 257–289. doi:10.1016/S0074-7696(02)20008-X. ISBN 978-0-12-364624-8. PMID 12224551.</ref><ref name="pmid15473833">Jaspersen, S. L.; Winey, M. (2004). "THE BUDDING YEAST SPINDLE POLE BODY: Structure, Duplication, and Function". Annual Review of Cell and Developmental Biology. 20 (1): 1–28. doi:10.1146/annurev.cellbio.20.022003.114106. PMID 15473833.</ref>
- Chain reaction
- Is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events.
- Change of base rule
- .
- Charles's law
- Charles's law (also known as the law of volumes) is an experimental gas law that describes how gases tend to expand when heated. A modern statement of Charles's law is: When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion.<ref>Fullick, P. (1994), Physics, Heinemann, pp. 141–142, ISBN 0-435-57078-1</ref>
- Chemical bond
- Is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds. The strength of chemical bonds varies considerably; there are "strong bonds" or "primary bonds" such as covalent, ionic and metallic bonds, and "weak bonds" or "secondary bonds" such as dipole–dipole interactions, the London dispersion force and hydrogen bonding.
- Chemical compound
- Is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds. A chemical element bonded to an identical chemical element is not a chemical compound since only one element, not two different elements, is involved.
- Chemical equilibrium
- In a chemical reaction, chemical equilibrium is the state in which both reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system.<ref name=Atkins>Atkins, Peter; De Paula, Julio (2006). Atkins' Physical Chemistry (8th ed.). W. H. Freeman. pp. 200–202. ISBN 978-0-7167-8759-4.</ref> Usually, this state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but equal. Thus, there are no net changes in the concentrations of the reactant(s) and product(s). Such a state is known as dynamic equilibrium.<ref name=aj>Atkins, Peter W.; Jones, Loretta (2008). Chemical Principles: The Quest for Insight (2nd ed.). W.H. Freeman. ISBN 978-0-7167-9903-0.</ref><ref>IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "chemical equilibrium". doi:10.1351/goldbook.C01023</ref>
- Chemical kinetics
- Chemical kinetics, also known as reaction kinetics, is the study of rates of chemical processes. Chemical kinetics includes investigations of how different experimental conditions can influence the speed of a chemical reaction and yield information about the reaction's mechanism and transition states, as well as the construction of mathematical models that can describe the characteristics of a chemical reaction.
- Chemical reaction
- A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another.<ref>IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "chemical reaction". doi:10.1351/goldbook.C01033</ref> Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.
- Chemistry
- Is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.<ref>"What is Chemistry?". Chemweb.ucc.ie. Archived from the original on 3 October 2018. Retrieved 12 June 2011.</ref><ref>"Definition of CHEMISTRY". www.merriam-webster.com. Retrieved 24 August 2020.</ref><ref>"Definition of chemistry | Dictionary.com". www.dictionary.com. Retrieved 24 August 2020.</ref><ref>"Chemistry Is Everywhere". American Chemical Society.</ref>
- Chloride
- Any chemical compound containing the element chlorine.
- Chromate
- Chromate salts contain the chromate anion, CrO2−
4. Dichromate salts contain the dichromate anion, Cr
2O2−
7. They are oxyanions of chromium in the 6+ oxidation state . They are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible. - Circular motion
- In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts. The equations of motion describe the movement of the center of mass of a body.
- Civil engineering
- The profession that deals with the design and construction of structures, or other fixed works.
- Clausius–Clapeyron relation
- The Clausius–Clapeyron relation, named after Rudolf Clausius<ref name="clausius">Clausius, R. (1850). "Ueber die bewegende Kraft der Wärme und die Gesetze, welche sich daraus für die Wärmelehre selbst ableiten lassen" [On the motive power of heat and the laws which can be deduced therefrom regarding the theory of heat]. Annalen der Physik (in Deutsch). 155 (4): 500–524. Bibcode:1850AnP...155..500C. doi:10.1002/andp.18501550403. hdl:2027/uc1.$b242250.</ref> and Benoît Paul Émile Clapeyron,<ref name="clapeyron">Clapeyron, M. C. (1834). "Mémoire sur la puissance motrice de la chaleur". Journal de l'École Polytechnique (in français). 23: 153–190. ark:/12148/bpt6k4336791/f157.</ref> is a way of characterizing a discontinuous phase transition between two phases of matter of a single constituent. On a pressure–temperature (P–T) diagram, the line separating the two phases is known as the coexistence curve. The Clausius–Clapeyron relation gives the slope of the tangents to this curve. Mathematically,
- <math>\frac{\mathrm{d}P}{\mathrm{d}T} = \frac{L}{T\,\Delta v}=\frac{\Delta s}{\Delta v}, </math>
- Clausius inequality
- .
- Clausius theorem
- The Clausius theorem (1855) states that a system exchanging heat with external reservoirs and undergoing a cyclic process, is one that ultimately returns a system to its original state,
- <math>\oint \frac{\delta Q}{T_{surr \leq 0,</math>
where <math>\delta Q</math> is the infinitesimal amount of heat absorbed by the system from the reservoir and <math>T_{surr}</math> is the temperature of the external reservoir (surroundings) at a particular instant in time. In the special case of a reversible process, the equality holds.<ref>Clausius theorem at Wolfram Research</ref> The reversible case is used to introduce the entropy state function. This is because in a cyclic process the variation of a state function is zero. In words, the Clausius statement states that it is impossible to construct a device whose sole effect is the transfer of heat from a cool reservoir to a hot reservoir.<ref>Finn, Colin B. P. Thermal Physics. 2nd ed., CRC Press, 1993.</ref> Equivalently, heat spontaneously flows from a hot body to a cooler one, not the other way around.<ref>Giancoli, Douglas C. Physics: Principles with Applications. 6th ed., Pearson/Prentice Hall, 2005.</ref> The generalized "inequality of Clausius"<ref>Mortimer, R. G. Physical Chemistry. 3rd ed., p. 120, Academic Press, 2008.</ref>
- <math>dS > \frac{\delta Q}{T_{surr}} </math>
for an infinitesimal change in entropy S applies not only to cyclic processes, but to any process that occurs in a closed system. }}
{{cite web}}: CS1 maint: archived copy as title (link)</ref><ref>"COP (Coefficient of performance)".</ref> Higher COPs equate to lower operating costs. The COP usually exceeds 1, especially in heat pumps, because, instead of just converting work to heat (which, if 100% efficient, would be a COP_hp of 1), it pumps additional heat from a heat source to where the heat is required. For complete systems, COP calculations should include energy consumption of all power consuming auxiliaries. COP is highly dependent on operating conditions, especially absolute temperature and relative temperature between sink and system, and is often graphed or averaged against expected conditions.<ref>"Archived copy" (PDF). Archived from the original (PDF) on 2009-01-07. Retrieved 2013-10-16.{{cite web}}: CS1 maint: archived copy as title (link)</ref>Computer System engineering has traditionally been viewed as a combination of both electronic engineering (EE) and computer science (CS).</ref>
- <math>1 ~ \text{C} = 1 ~ \text{A} \cdot 1 ~ \text{s}</math>
- <math>1 ~ \text{C} = 1 ~ \text{F} \cdot 1 ~ \text{V}</math>
- <math>F=k_e\frac{q_1 q_2}{r^2}</math>,
D
- Dalton's law
- In chemistry and physics, Dalton's law (also called Dalton's law of partial pressures) states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.<ref name="Silberberg">Silberberg, Martin S. (2009). Chemistry: the molecular nature of matter and change (5th ed.). Boston: McGraw-Hill. p. 206. ISBN 978-0-07-304859-8.</ref>
- Damped vibration
- Any vibration with a force acting against it to lessen the vibration over time.
- Darcy–Weisbach equation
- An equation used in fluid mechanics to find the pressure change cause by friction within a pipe or conduit.
- DC motor
- An electrical motor driven by direct current.
- Decibel
- A logarithmic unit of ratios.
- Definite integral
- The integral of a function between an upper and lower limit.<ref>Wiktionary</ref>
- Deflection
- Is the degree to which a structural element is displaced under a load. It may refer to an angle or a distance.
- Deformation (engineering)
- In materials science, deformation refers to any changes in the shape or size of an object due to
- an applied force (the deformation energy in this case is transferred through work) or
- a change in temperature (the deformation energy in this case is transferred through heat).
- Deformation (mechanics)
- Deformation in continuum mechanics is the transformation of a body from a reference configuration to a current configuration.<ref>Truesdell, C.; Noll, W. (2004). The non-linear field theories of mechanics (3rd ed.). Springer. p. 48.</ref> A configuration is a set containing the positions of all particles of the body. A deformation may be caused by external loads,<ref name=wu>Wu, H.-C. (2005). Continuum Mechanics and Plasticity. CRC Press. ISBN 978-1-58488-363-0.</ref> body forces (such as gravity or electromagnetic forces), or changes in temperature, moisture content, or chemical reactions, etc.
- Degrees of freedom
- The number of parameters required to define the motion of a dynamical system.
- Delta robot
- A tripod linkage, used to construct fast-acting manipulators with a wide range of movement.
- Delta-wye transformer
- A type of transformer used in three-phase power systems.
- De Moivre–Laplace theorem
- In probability theory, the de Moivre–Laplace theorem, which is a special case of the central limit theorem, states that the normal distribution may be used as an approximation to the binomial distribution under certain conditions. In particular, the theorem shows that the probability mass function of the random number of "successes" observed in a series of <math>n</math> independent Bernoulli trials, each having probability <math>p</math> of success (a binomial distribution with <math>n</math> trials), converges to the probability density function of the normal distribution with mean <math>np</math> and standard deviation<math>\sqrt{np(1-p)}</math>, as <math>n</math> grows large, assuming <math>p</math> is not <math>0</math> or <math>1</math>.
- Density
- The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho), although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume:<ref>The National Aeronautic and Atmospheric Administration's Glenn Research Center. "Gas Density Glenn research Center". grc.nasa.gov. Archived from the original on April 14, 2013. Retrieved March 31, 2019.</ref>
- <math> \rho = \frac{m}{V}</math>
- Derivative
- The derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. For example, the derivative of the position of a moving object with respect to time is the object's velocity: this measures how quickly the position of the object changes when time advances.
- Design engineering
- .
- Dew point
- The pressure and temperature at which air is holding the maximum possible humidity.
- Diamagnetism
- Diamagnetic materials are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field. Diamagnetism is a quantum mechanical effect that occurs in all materials; when it is the only contribution to the magnetism, the material is called diamagnetic. In paramagnetic and ferromagnetic substances the weak diamagnetic force is overcome by the attractive force of magnetic dipoles in the material. The magnetic permeability of diamagnetic materials is less than μ0, the permeability of vacuum. In most materials diamagnetism is a weak effect which can only be detected by sensitive laboratory instruments, but a superconductor acts as a strong diamagnet because it repels a magnetic field entirely from its interior.
- Dielectric
- An insulator, a material that does not permit free flow of electricity.
- Differential pressure
- .
- Differential pulley
- A differential pulley, also called Weston differential pulley, or colloquially chain fall, is used to manually lift very heavy objects like car engines. It is operated by pulling upon the slack section of a continuous chain that wraps around pulleys. The relative size of two connected pulleys determines the maximum weight that can be lifted by hand. The load will remain in place (and not lower under the force of gravity) until the chain is pulled.<ref>Macauley, David; Ardley, Neil (1998). The New Way Things Work. Boston, USA: Houghton Mifflin Company. p. 56. ISBN 978-0-395-93847-8.</ref>
- Differential signaling
- Is a method for electrically transmitting information using two complementary signals.
- Diffusion
- Is the net movement of molecules or atoms from a region of higher concentration (or high chemical potential) to a region of lower concentration (or low chemical potential).
- Dimensional analysis
- is the analysis of the relationships between different physical quantities by identifying their base quantities (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms) and tracking these dimensions as calculations or comparisons are performed. The conversion of units from one dimensional unit to another is often somewhat complex. Dimensional analysis, or more specifically the factor-label method, also known as the unit-factor method, is a widely used technique for such conversions using the rules of algebra.<ref>Goldberg, David (2006). Fundamentals of Chemistry (5th ed.). McGraw-Hill. ISBN 978-0-07-322104-5.</ref><ref>Ogden, James (1999). The Handbook of Chemical Engineering. Research & Education Association. ISBN 978-0-87891-982-6.</ref><ref>"Dimensional Analysis or the Factor Label Method". Mr Kent's Chemistry Page.</ref>
- Direct integration of a beam
- Direct integration is a structural analysis method for measuring internal shear, internal moment, rotation, and deflection of a beam.
For a beam with an applied weight <math>w(x) </math>, taking downward to be positive, the internal shear force is given by taking the negative integral of the weight:
- <math>V(x) = -\int w(x)\, dx</math>
- <math>M(x) = \int V(x)\, dx</math> = <math> -\int [\int w(x)\ \, dx] dx </math>
- <math>\theta (x) = \frac{1}{EI} \int M(x)\, dx </math>
- <math>\nu (x) = \int \theta (x) dx </math>.
E
- Economics
- The scientific study of the production, distribution and consumption of goods.
- Effusion
- In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules.<ref>K.J. Laidler and J.H. Meiser, Physical Chemistry, Benjamin/Cummings 1982, p.18. ISBN 0-8053-5682-7</ref>
- Elastic modulus
- The amount a material will deform per unit force.
- Elasticity
- In physics, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate forces are applied to them. If the material is elastic, the object will return to its initial shape and size when these forces are removed.
- Electric charge
- is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges; positive and negative (commonly carried by protons and electrons respectively). Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects.
- Electric circuit
- Is an electrical network consisting of a closed loop, giving a return path for the current.
- Electric current
- Is a flow of electric charge.<ref name="horowitz">Horowitz, Paul; Hill, Winfield (2015). The art of electronics (3rd ed.). Cambridge University Press. ISBN 978-0-521-80926-9.</ref>: 2 In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma).<ref>Anthony C. Fischer-Cripps (2004). The electronics companion. CRC Press. p. 13. ISBN 978-0-7503-1012-3.</ref> The SI unit for measuring an electric current is the ampere, which is the flow of electric charge across a surface at the rate of one coulomb per second. Electric current is measured using a device called an ammeter.<ref name="learn-physics-today">Lakatos, John; Oenoki, Keiji; Judez, Hector; Oenoki, Kazushi; Hyun Kyu Cho (March 1998). "Learn Physics Today!". Lima, Peru: Colegio Dr. Franklin D. Roosevelt. Archived from the original on 2009-02-27. Retrieved 2009-03-10.</ref>
- Electric displacement field
- In physics, the electric displacement field, denoted by D, is a vector field that appears in Maxwell's equations. It accounts for the effects of free and bound charge within materials. "D" stands for "displacement", as in the related concept of displacement current in dielectrics. In free space, the electric displacement field is equivalent to flux density, a concept that lends understanding to Gauss's law. In the International System of Units (SI), it is expressed in units of coulomb per meter squared (C⋅m−2).
- Electric generator
- In electricity generation, a generator,also called electric generator, electrical generator, and electromagnetic generator. is a device that converts motive power (mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines and even hand cranks.
- Electric field
- Surrounds an electric charge, and exerts force on other charges in the field, attracting or repelling them.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Browne, p 225: "... around every charge there is an aura that fills all space. This aura is the electric field due to the charge. The electric field is a vector field... and has a magnitude and direction."</ref> Electric field is sometimes abbreviated as E-field. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electric field gradient
- In atomic, molecular, and solid-state physics, the electric field gradient (EFG) measures the rate of change of the electric field at an atomic nucleus generated by the electronic charge distribution and the other nuclei. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electric motor
- Is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and winding currents to generate force in the form of rotation. Electric motors can be powered by direct current (DC) sources, such as from batteries, motor vehicles or rectifiers, or by alternating current (AC) sources, such as a power grid, inverters or electrical generators. An electric generator is mechanically identical to an electric motor, but operates in the reverse direction, accepting mechanical energy (such as from flowing water) and converting this mechanical energy into electrical energy. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electric potential
- (Also called the electric field potential, potential drop or the electrostatic potential) is the amount of work needed to move a unit of positive charge from a reference point to a specific point inside the field without producing an acceleration. Typically, the reference point is the Earth or a point at infinity, although any point beyond the influence of the electric field charge can be used. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical potential energy
- Electric potential energy, or electrostatic potential energy, is a potential energy (measured in joules) that results from conservative Coulomb forces and is associated with the configuration of a particular set of point charges within a defined system. An object may have electric potential energy by virtue of two key elements: its own electric charge and its relative position to other electrically charged objects. The term "electric potential energy" is used to describe the potential energy in systems with time-variant electric fields, while the term "electrostatic potential energy" is used to describe the potential energy in systems with time-invariant electric fields. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electric power
- Is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical engineering
- Is a technical discipline concerned with the study, design and application of equipment, devices and systems which use electricity, electronics, and electromagnetism. It emerged as an identified activity in the latter half of the 19th century after commercialization of the electric telegraph, the telephone, and electrical power generation, distribution and use. . <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical conductance
- The electrical resistance of an object is a measure of its opposition to the flow of electric current. The inverse quantity is electrical conductance, and is the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with the notion of mechanical friction. The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical conductor
- Is an object or type of material that allows the flow of charge (electrical current) in one or more directions. Materials made of metal are common electrical conductors. Electrical current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical impedance
- Is the measure of the opposition that a circuit presents to a current when a voltage is applied. The term complex impedance may be used interchangeably. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical insulator
- Is a material whose internal electric charges do not flow freely; very little electric current will flow through it under the influence of an electric field. This contrasts with other materials, semiconductors and conductors, which conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical network
- Is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, current sources, resistances, inductances, capacitances). An electrical circuit is a network consisting of a closed loop, giving a return path for the current. Linear electrical networks, a special type consisting only of sources (voltage or current), linear lumped elements (resistors, capacitors, inductors), and linear distributed elements (transmission lines), have the property that signals are linearly superimposable. They are thus more easily analyzed, using powerful frequency domain methods such as Laplace transforms, to determine DC response, AC response, and transient response. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrical resistance
- The electrical resistance of an object is a measure of its opposition to the flow of electric current. The inverse quantity is electrical conductance, and is the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with the notion of mechanical friction. The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electricity
- Is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electrodynamics
- In physics, the phenomena associated with moving electric charges, and their interaction with electric and magnetic fields; the study of these phenomena.<ref>Wiktionary</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electromagnet
- Is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole, denoting the centre of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electromagnetic field
- An electromagnetic field (also EM field) is a classical (i.e. non-quantum) field produced by accelerating electric charges.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> It is the field described by classical electrodynamics and is the classical counterpart to the quantized electromagnetic field tensor in quantum electrodynamics. The electromagnetic field propagates at the speed of light (in fact, this field can be identified as light) and interacts with charges and currents. Its quantum counterpart is one of the four fundamental forces of nature (the others are gravitation, weak interaction and strong interaction.) <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electromagnetic radiation
- In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy.<ref>*Lua error: Internal error: The interpreter has terminated with signal "24". p 430: "These waves... require no medium to support their propagation. Traveling electromagnetic waves carry energy, and... the Poynting vector describes the energy flow...;" p 440: ... the electromagnetic wave must have the following properties: 1) The field pattern travels with speed c (speed of light); 2) At every point within the wave... the electric field strength E equals "c" times the magnetic field strength B; 3) The electric field and the magnetic field are perpendicular to one another and to the direction of travel, or propagation."</ref> It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.<ref>* Lua error: Internal error: The interpreter has terminated with signal "24".; p319: "For historical reasons, different portions of the EM spectrum are given different names, although they are all the same kind of thing. Visible light constitutes a narrow range of the spectrum, from wavelengths of about 400–800 nm.... ;p 320 "An electromagnetic wave carries forward momentum... If the radiation is absorbed by a surface, the momentum drops to zero and a force is exerted on the surface... Thus the radiation pressure of an electromagnetic wave is (formula)."</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electromechanics
- Electromechanics<ref>Course in Electro-mechanics, for Students in Electrical Engineering, 1st Term of 3d Year, Columbia University, Adapted from Prof. F.E. Nipher's "Electricity and Magnetism". By Fitzhugh Townsend. 1901.</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>The Elements of Electricity, "Part V. Electro-Mechanics." By Wirt Robinson. John Wiley & sons, Incorporated, 1922.</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> combines processes and procedures drawn from electrical engineering and mechanical engineering. Electromechanics focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each other. This process is especially prominent in systems such as those of DC or AC rotating electrical machines which can be designed and operated to generate power from a mechanical process (generator) or used to power a mechanical effect (motor). Electrical engineering in this context also encompasses electronics engineering. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electron
- Is a subatomic particle, symbol Lua error: Internal error: The interpreter has terminated with signal "24". or Lua error: Internal error: The interpreter has terminated with signal "24"., whose electric charge is negative one elementary charge.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> Electrons belong to the first generation of the lepton particle family,<ref name="curtis74"> Lua error: Internal error: The interpreter has terminated with signal "24".</ref> and are generally thought to be elementary particles because they have no known components or substructure.<ref>Lua error: Internal error: The interpreter has terminated with signal "24". OSTI 1446807.</ref> The electron has a mass that is approximately 1/1836 that of the proton.<ref>"CODATA value: proton–electron mass ratio". 2006 CODATA recommended values. National Institute of Standards and Technology. Retrieved 18 July 2009.</ref> Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ. Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle.<ref name="curtis74"/> Like all elementary particles, electrons exhibit properties of both particles and waves: they can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavelength for a given energy. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electronvolt
- In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum. When used as a unit of energy, the numerical value of 1 eV in joules (symbol J) is equivalent to the numerical value of the charge of an electron in coulombs (symbol C). Under the 2019 redefinition of the SI base units, this sets 1 eV equal to the exact value Lua error: Internal error: The interpreter has terminated with signal "24"..<ref name="physconst-eV">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electron pair
- In chemistry, an electron pair, or Lewis pair, consists of two electrons that occupy the same molecular orbital but have opposite spins. Gilbert N. Lewis introduced the concepts of both the electron pair and the covalent bond in a landmark paper he published in 1916.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electronegativity
- Symbolized as χ, is the measurement of the tendency of an atom to attract a shared pair of electrons (or electron density).<ref name="definition">IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Electronegativity". Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".</ref> An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Electronics
- Comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> It uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering which uses passive effects such as resistance, capacitance and inductance to control current flow. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Elemental analysis
- Is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compounds) is analyzed for its elemental and sometimes isotopic composition.Lua error: Internal error: The interpreter has terminated with signal "24". Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative (determining how much of each are present). Elemental analysis falls within the ambit of analytical chemistry, the set of instruments involved in deciphering the chemical nature of our world. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Endothermic process
- Is any process with an increase in the enthalpy H (or internal energy U) of the system.<ref name="Oxtoby8th">Oxtoby, D. W; Gillis, H.P., Butler, L. J. (2015).Principles of Modern Chemistry, Brooks Cole. p. 617. Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".</ref> In such a process, a closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system. It may be a chemical process, such as dissolving ammonium nitrate in water, or a physical process, such as the melting of ice cubes. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Energy
- In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.<ref group=note>The second law of thermodynamics imposes limitations on the capacity of a system to transfer energy by performing work, since some of the system's energy might necessarily be consumed in the form of heat instead. See e.g. Lua error: Internal error: The interpreter has terminated with signal "24".</ref> Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Engine
- An engine or motor is a machine designed to convert one form of energy into mechanical energy.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Dictionary.com: (World heritage) "3. any device that converts another form of energy into mechanical energy so as to produce motion"</ref> Heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a heat engine, in which heat from the combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston, which turns a crankshaft. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and ultimately motion. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Engineering
- Is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> The discipline of engineering encompasses a broad range of more specialized fields of engineering, each with a more specific emphasis on particular areas of applied mathematics, applied science, and types of application. The term engineering is derived from the Latin ingenium, meaning "cleverness" and ingeniare, meaning "to contrive, devise".<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Engineering economics
- Engineering economics, previously known as engineering economy, is a subset of economics concerned with the use and "...application of economic principles"<ref name="Dharmaraj2009">Dharmaraj, E.. Engineering Economics. Mumbai, IN: Himalaya Publishing House, 2009. ProQuest ebrary. Web. 9 November 2016.</ref> in the analysis of engineering decisions.<ref name="Morris1960">Morris, W. Thomas. (1960). Engineering economy: the analysis of management decisions. Homewood, Ill.: R. D. Irwin.</ref> As a discipline, it is focused on the branch of economics known as microeconomics in that it studies the behavior of individuals and firms in making decisions regarding the allocation of limited resources. Thus, it focuses on the decision making process, its context and environment.<ref name="Dharmaraj2009" /> It is pragmatic by nature, integrating economic theory with engineering practice.<ref name="Dharmaraj2009" /> But, it is also a simplified application of microeconomic theory in that it assumes elements such as price determination, competition and demand/supply to be fixed inputs from other sources.<ref name="Dharmaraj2009" /> As a discipline though, it is closely related to others such as statistics, mathematics and cost accounting.<ref name="Dharmaraj2009" /> It draws upon the logical framework of economics but adds to that the analytical power of mathematics and statistics.<ref name="Dharmaraj2009" /> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Engineering ethics
- Is the field of system of moral principles that apply to the practice of engineering. The field examines and sets the obligations by engineers to society, to their clients, and to the profession. As a scholarly discipline, it is closely related to subjects such as the philosophy of science, the philosophy of engineering, and the ethics of technology. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Environmental engineering
- Is a job type that is a professional engineering discipline and takes from broad scientific topics like chemistry, biology, ecology, geology, hydraulics, hydrology, microbiology, and mathematics to create solutions that will protect and also improve the health of living organisms and improve the quality of the environment.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>"Bureau of Labor Statistics, U.S. Department of Labor.U.S. Department of Labor, Occupational Outlook Handbook, 2010–11 Edition"</ref> Environmental engineering is a sub-discipline of civil engineering and chemical engineering. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Engineering physics
- Or engineering science, refers to the study of the combined disciplines of physics, mathematics, chemistry, biology, and engineering, particularly computer, nuclear, electrical, electronic, aerospace, materials or mechanical engineering. By focusing on the scientific method as a rigorous basis, it seeks ways to apply, design, and develop new solutions in engineering.<ref>"Major: Engineering Physics". The Princeton Review. 2017. p. 01. Retrieved June 4, 2017.</ref><ref>"Introduction" (online). Princeton University. Retrieved June 26, 2011.</ref><ref>Khare, P.; A. Swarup (2009-01-26). Engineering Physics: Fundamentals & Modern Applications (13th ed.). Jones & Bartlett Learning. pp. xiii–Preface. ISBN 978-0-7637-7374-8.</ref><ref>Physics (online). Retrieved June 26, 2011.</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Enzyme
- Enzymes are proteins that act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life.<ref name = "Stryer_2002">Lua error: Internal error: The interpreter has terminated with signal "24".
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<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Escape velocity - The minimum velocity at which an object can escape a gravitation field. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Estimator
- In statistics, an estimator is a rule for calculating an estimate of a given quantity based on observed data: thus the rule (the estimator), the quantity of interest (the estimand) and its result (the estimate) are distinguished.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> For example, the sample mean is a commonly used estimator of the population mean. There are point and interval estimators. The point estimators yield single-valued results, although this includes the possibility of single vector-valued results and results that can be expressed as a single function. This is in contrast to an interval estimator, where the result would be a range of plausible values (or vectors or functions). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Euler–Bernoulli beam theory
- Euler–Bernoulli beam theory (also known as engineer's beam theory or classical beam theory)<ref name=Timoshenko>Timoshenko, S., (1953), History of strength of materials, McGraw-Hill New York</ref> is a simplification of the linear theory of elasticity which provides a means of calculating the load-carrying and deflection characteristics of beams. It covers the case for small deflections of a beam that are subjected to lateral loads only. It is thus a special case of Timoshenko beam theory. It was first enunciated circa 1750,<ref name=Truesdell>Truesdell, C., (1960), The rational mechanics of flexible or elastic bodies 1638–1788, Venditioni Exponunt Orell Fussli Turici.</ref> but was not applied on a large scale until the development of the Eiffel Tower and the Ferris wheel in the late 19th century. Following these successful demonstrations, it quickly became a cornerstone of engineering and an enabler of the Second Industrial Revolution. Additional mathematical models have been developed such as plate theory, but the simplicity of beam theory makes it an important tool in the sciences, especially structural and mechanical engineering. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Exothermic process
- In thermodynamics, the term exothermic process (exo- : "outside") describes a process or reaction that releases energy from the system to its surroundings, usually in the form of heat, but also in a form of light (e.g. a spark, flame, or flash), electricity (e.g. a battery), or sound (e.g. explosion heard when burning hydrogen). Its etymology stems from the Greek prefix έξω (exō, which means "outwards") and the Greek word θερμικός (thermikόs, which means "thermal").<ref>"Gate for the Greek language" on-line dictionary Lua error: Internal error: The interpreter has terminated with signal "24".. greek-language.gr</ref>
F
-
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Factor of safety
- (FoS), also known as (and used interchangeably with) safety factor (SF), expresses how much stronger a system is than it needs to be for an intended load. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Falling bodies
- . <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Farad
- <ref>The International System of Units (SI) (8th ed.). Bureau International des Poids et Mesures (International Committee for Weights and Measures). 2006. p. 144.</ref> The farad (symbol: F) is the SI derived unit of electrical capacitance, the ability of a body to store an electrical charge. It is named after the English physicist Michael Faraday. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Faraday constant
- Denoted by the symbol FLua error: Internal error: The interpreter has terminated with signal "24". and sometimes stylized as ℱ, is named after Michael Faraday. In physics and chemistry, this constant represents the magnitude of electric charge per mole of electrons.<ref>The term "magnitude" is used in the sense of "absolute value": The charge of an electron is negative, but F is always defined to be positive.</ref> It has the value
- Lua error: Internal error: The interpreter has terminated with signal "24". C mol−1.<ref name="physconst-F">Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
- <math>F\,=\,eN_{A}</math>
- e = Lua error: Internal error: The interpreter has terminated with signal "24".;<ref name="physconst-e">Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
- NA = Lua error: Internal error: The interpreter has terminated with signal "24"..<ref name="physconst-NA">Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fermat's principle - In optics, Fermat's principle, or the principle of least time, named after French mathematician Pierre de Fermat, is the principle that the path taken between two points by a ray of light is the path that can be traversed in the least time. This principle is sometimes taken as the definition of a ray of light.<ref>Arthur Schuster, An Introduction to the Theory of Optics, London: Edward Arnold, 1904 online.</ref> However, this version of the principle is not general; a more modern statement of the principle is that rays of light traverse the path of stationary optical length with respect to variations of the path.<ref>Lua error: Internal error: The interpreter has terminated with signal "24". </ref> In other words, a ray of light prefers the path such that there are other paths, arbitrarily nearby on either side, along which the ray would take almost exactly the same time to traverse. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fick's laws of diffusion
- Describe diffusion and were derived by Adolf Fick in 1855. They can be used to solve for the diffusion coefficient, D. Fick's first law can be used to derive his second law which in turn is identical to the diffusion equation. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Finite element method
- (FEM), is the most widely used method for solving problems of engineering and mathematical models. Typical problem areas of interest include the traditional fields of structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. The FEM is a particular numerical method for solving partial differential equations in two or three space variables (i.e., some boundary value problems). To solve a problem, the FEM subdivides a large system into smaller, simpler parts that are called finite elements. This is achieved by a particular space discretization in the space dimensions, which is implemented by the construction of a mesh of the object: the numerical domain for the solution, which has a finite number of points. The finite element method formulation of a boundary value problem finally results in a system of algebraic equations. The method approximates the unknown function over the domain.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> The simple equations that model these finite elements are then assembled into a larger system of equations that models the entire problem. The FEM then uses variational methods from the calculus of variations to approximate a solution by minimizing an associated error function. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">FIRST
- For Inspiration and Recognition of Science and Technology – is an organization founded by inventor Dean Kamen in 1989 to develop ways to inspire students in engineering and technology fields. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fission
- In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into two or more smaller, lighter nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Flow velocity
- In continuum mechanics the flow velocity in fluid dynamics, also macroscopic velocity<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> in statistical mechanics, or drift velocity in electromagnetism, is a vector field used to mathematically describe the motion of a continuum. The length of the flow velocity vector is the flow speed and is a scalar. It is also called velocity field; when evaluated along a line, it is called a velocity profile (as in, e.g., law of the wall). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fluid
- In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress, or external force. Fluids are a phase of matter and include liquids, gases and plasmas. They are substances with zero shear modulus, or, in simpler terms, substances which cannot resist any shear force applied to them. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fluid dynamics
- In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fluid mechanics
- Is the branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas) and the forces on them.<ref>White, Frank M. (2011). Fluid Mechanics (7th ed.). McGraw-Hill. Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24"..</ref> It has applications in a wide range of disciplines, including mechanical, civil, chemical and biomedical engineering, geophysics, oceanography, meteorology, astrophysics, and biology. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fluid statics
- Fluid statics, or hydrostatics, is the branch of fluid mechanics that studies "fluids at rest and the pressure in a fluid or exerted by a fluid on an immersed body".<ref name="MW dictionary def">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Flywheel
- Is a mechanical device specifically designed to use the conservation of angular momentum so as to efficiently store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, if we assume the flywheel's moment of inertia to be constant (i.e., a flywheel with fixed mass and second moment of area revolving about some fixed axis) then the stored (rotational) energy is directly associated with the square of its rotational speed. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Focus
- In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics. In the absence of significant aberrations, the smallest possible blur circle is the Airy disc, which is caused by diffraction from the optical system's aperture. Aberrations tend worsen as the aperture diameter increases, while the Airy circle is smallest for large apertures. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Foot-pound
- The foot-pound force (symbol: ft⋅lbf,<ref>IEEE Std 260.1-2004, IEEE Standard Letter Symbols for Units of Measurement (SI Units, Customary Inch-Pound Units, and Certain Other Units)</ref> ft⋅lbf,<ref name="isbn_978-0135018583">Lua error: Internal error: The interpreter has terminated with signal "24".<span title="Lua error: Internal error: The interpreter has terminated with signal "24".">: Lua error: Internal error: The interpreter has terminated with signal "24". </ref> or ft⋅lb <ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref>) is a unit of work or energy in the engineering and gravitational systems in United States customary and imperial units of measure. It is the energy transferred upon applying a force of one pound-force (lbf) through a linear displacement of one foot. The corresponding SI unit is the joule. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fracture toughness
- In materials science, fracture toughness is the critical stress intensity factor of a sharp crack where propagation of the crack suddenly becomes rapid and unlimited. A component's thickness affects the constraint conditions at the tip of a crack with thin components having plane stress conditions and thick components having plane strain conditions. Plane strain conditions give the lowest fracture toughness value which is a material property. The critical value of stress intensity factor in mode I loading measured under plane strain conditions is known as the plane strain fracture toughness, denoted <math>K_\text{Ic}</math>.<ref name="suresh04">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> When a test fails to meet the thickness and other test requirements that are in place to ensure plane strain conditions, the fracture toughness value produced is given the designation <math>K_\text{c}</math>. Fracture toughness is a quantitative way of expressing a material's resistance to crack propagation and standard values for a given material are generally available. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fraunhofer lines
- In physics and optics, the Fraunhofer lines are a set of spectral absorption lines named after the German physicist Joseph von Fraunhofer (1787–1826). The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Free fall
- In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Frequency modulation
- Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Freezing point
- The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the melting point.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Friction
- Is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> There are several types of friction:
- Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1).
- Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other.<ref name="Beer">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Meriam">Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
- Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces.<ref name="Ruina">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Hibbeler">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Soutas-Little">Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
- Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body.
- Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.<ref name="Meriam"/>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Function - In mathematics, a function<ref group=note>The words map, mapping, transformation, correspondence, and operator are often used synonymously. Lua error: Internal error: The interpreter has terminated with signal "24"..</ref> is a binary relation between two sets that associates every element of the first set to exactly one element of the second set. Typical examples are functions from integers to integers, or from the real numbers to real numbers. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fundamental frequency
- The fundamental frequency, often referred to simply as the fundamental, is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical pitch of a note that is perceived as the lowest partial present. In terms of a superposition of sinusoids, the fundamental frequency is the lowest frequency sinusoidal in the sum of harmonically related frequencies, or the frequency of the difference between adjacent frequencies. In some contexts, the fundamental is usually abbreviated as f0, indicating the lowest frequency counting from zero.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> In other contexts, it is more common to abbreviate it as f1, the first harmonic.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> (The second harmonic is then f2 = 2⋅f1, etc. In this context, the zeroth harmonic would be 0 Hz.) <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fundamental interaction
- In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electromagnetic interactions, which produce significant long-range forces whose effects can be seen directly in everyday life, and the strong and weak interactions, which produce forces at minuscule, subatomic distances and govern nuclear interactions. Some scientists hypothesize that a fifth force might exist, but these hypotheses remain speculative.<ref name="Fackler">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Weisstein">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Franklin">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fundamental theorem of calculus
- Is a theorem that links the concept of differentiating a function with the concept of integrating a function. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Fundamentals of Engineering Examination (US)
- The Fundamentals of Engineering (FE) exam, also referred to as the Engineer in Training (EIT) exam, and formerly in some states as the Engineering Intern (EI) exam, is the first of two examinations that engineers must pass in order to be licensed as a Professional Engineer in the United States. The second examination is Principles and Practice of Engineering Examination. The FE exam is open to anyone with a degree in engineering or a related field, or currently enrolled in the last year of an ABET-accredited engineering degree program. Some state licensure boards permit students to take it prior to their final year, and numerous states allow those who have never attended an approved program to take the exam if they have a state-determined number of years of work experience in engineering. Some states allow those with ABET-accredited "Engineering Technology" or "ETAC" degrees to take the examination. The state of Michigan has no admission pre-requisites for the FE.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> The exam is administered by the National Council of Examiners for Engineering and Surveying (NCEES).
G
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<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Galvanic cell
- A galvanic cell or voltaic cell, named after Luigi Galvani or Alessandro Volta, respectively, is an electrochemical cell that derives electrical energy from spontaneous redox reactions taking place within the cell. It generally consists of two different metals immersed in electrolytes, or of individual half-cells with different metals and their ions in solution connected by a salt bridge or separated by a porous membrane. Volta was the inventor of the voltaic pile, the first electrical battery. In common usage, the word "battery" has come to include a single galvanic cell, but a battery properly consists of multiple cells.<ref>"battery" (def. 4b), Merriam-Webster Online Dictionary (2008). Retrieved 6 August 2008.</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gamma rays
- A gamma ray, or gamma radiation (symbol γ or <math>\gamma</math>), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves and so imparts the highest photon energy. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gas
- Is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture, such as air, contains a variety of pure gases. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gauge pressure
- Is zero-referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Geiger counter
- Is an instrument used for detecting and measuring ionizing radiation. Also known as a Geiger–Muller counter (or Geiger–Müller counter), it is widely used in applications such as radiation dosimetry, radiological protection, experimental physics, and the nuclear industry. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">General relativity
- General relativity, also known as the general theory of relativity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Geometric mean
- In mathematics, the geometric mean is a mean or average, which indicates the central tendency or typical value of a set of numbers by using the product of their values (as opposed to the arithmetic mean which uses their sum). The geometric mean is defined as the nLua error: Internal error: The interpreter has terminated with signal "24".th root of the product of n numbers, i.e., for a set of numbers x1, x2, ..., xnLua error: Internal error: The interpreter has terminated with signal "24"., the geometric mean is defined as
- <math>\left(\prod_{i=1}^n x_i\right)^\frac{1}{n} = \sqrt[n]{x_1 x_2 \cdots x_n}</math>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Geometry
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Geophysics
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Geotechnical engineering
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gluon
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Graham's law
- <math>{\mbox{Rate}_1 \over \mbox{Rate}_2}=\sqrt{M_2 \over M_1}</math>,
- Rate1 is the rate of effusion for the first gas. (volume or number of moles per unit time).
- Rate2 is the rate of effusion for the second gas.
- M1 is the molar mass of gas 1
- M2 is the molar mass of gas 2.
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravitational constant
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravitational energy
- <math>U = -\frac{GMm}{R},</math>
- <math>U = mgh</math>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravitational field
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravitational potential
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravitational wave
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Gravity
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ground state
H
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<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Half-life
- The period at which one-half of a quantity of an unstable isotope has decayed into other elements; the time at which half of a substance has diffused out of or otherwise reacted in a system. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Haptic
- Tactile feedback technology using the operator's sense of touch. Also sometimes applied to robot manipulators with their own touch sensitivity. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hardness
- Is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Harmonic mean
- In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average, and in particular, one of the Pythagorean means. Typically, it is appropriate for situations when the average of rates is desired.
The harmonic mean can be expressed as the reciprocal of the arithmetic mean of the reciprocals of the given set of observations. As a simple example, the harmonic mean of 1, 4, and 4 is
- <math>\left(\frac{1^{-1} + 4^{-1} + 4^{-1 {3}\right)^{-1} = \frac{3}{\frac{1}{1} + \frac{1}{4} + \frac{1}{4}} = \frac{3}{1.5} = 2\,.</math>}}
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Heat
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Heat transfer
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Helmholtz free energy
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Henderson–Hasselbalch equation
- <math chem>\ce{pH} = \ce{p}K_\ce{a} + \log_{10} \left( \frac{[\ce{Base}]}{[\ce{Acid}]} \right)</math>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Henry's law
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hertz
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hexapod
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hexapod
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hoist
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Horsepower
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hot working
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Huygens–Fresnel principle
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hydraulics
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Hydrocarbon
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<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ice point
- The freezing point of pure water at one atmosphere; 0°C (32°F).<ref>Wiktionary</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ideal gas
- A model for gases that ignores intermolecular forces. Most gases are approximately ideal at some high temperature and low pressure. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ideal gas constant
- The constant in the gas law that relates pressure, volume and temperature. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ideal gas law
- Also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law.<ref>
Lua error: Internal error: The interpreter has terminated with signal "24". Facsimile at the Bibliothèque nationale de France (pp. 153–90).</ref> The ideal gas law is often written in an empirical form:
- <math>PV = nRT</math>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Identity - In mathematics, an identity is an equality relating one mathematical expression A to another mathematical expression B, such that A and B (which might contain some variables) produce the same value for all values of the variables within a certain range of validity.<ref name=":2">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> In other words, A = B is an identity if A and B define the same functions, and an identity is an equality between functions that are differently defined. For example, <math>(a+b)^2 = a^2 + 2ab + b^2</math> and <math>\cos^2\theta + \sin^2\theta =1</math> are identities.<ref name=":2"/> Identities are sometimes indicated by the triple bar symbol ≡Lua error: Internal error: The interpreter has terminated with signal "24". instead of =Lua error: Internal error: The interpreter has terminated with signal "24"., the equals sign.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Impedance (electrical)
- In electrical engineering, electrical impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Inclined plane
- Also known as a ramp, is a flat supporting surface tilted at an angle, with one end higher than the other, used as an aid for raising or lowering a load.<ref name="Cole">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="Edinformatics">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> The inclined plane is one of the six classical simple machines defined by Renaissance scientists. Inclined planes are widely used to move heavy loads over vertical obstacles; examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade.<ref name="Edinformatics" /> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Indefinite integral
- A function whose derivative is a given function; an antiderivative.<ref>https://en.wiktionary.org/wiki/indefinite_integral Wiktionary</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Inductance
- In electromagnetism and electronics, inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called back EMF. Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> An electronic component designed to add inductance to a circuit is called an inductor. It typically consists of a coil or helix of wire. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Inductor
- An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> An inductor typically consists of an insulated wire wound into a coil. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Industrial engineering
- Is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information and equipment. Industrial engineers use specialized knowledge and skills in the mathematical, physical and social sciences, together with the principles and methods of engineering analysis and design, to specify, predict, and evaluate the results obtained from systems and processes.<ref>Salvendy, Gabriel. Handbook of Industrial Engineering. John Wiley & Sons, Inc; 3rd edition p. 5</ref> From these results, they are able to create new systems, processes or situations for the useful coordination of labour, materials and machines and also improve the quality and productivity of systems, physical or social.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Inertia
- Is the resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight line at a constant speed, when no forces act upon them. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Infrasound
- Infrasound, sometimes referred to as low-frequency sound, describes sound waves with a frequency below the lower limit of audibility (generally 20 Hz). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing low sound, but at higher intensities it is possible to feel infrasound vibrations in various parts of the body. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Integral
- In mathematics, an integral assigns numbers to functions in a way that describes displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with differentiation, integration is a fundamental operation of calculus,<ref group="lower-alpha">Integral calculus is a very well established mathematical discipline for which there are many sources. See Lua error: Internal error: The interpreter has terminated with signal "24". and Lua error: Internal error: The interpreter has terminated with signal "24"., for example.</ref> and serves as a tool to solve problems in mathematics and physics involving the area of an arbitrary shape, the length of a curve, and the volume of a solid, among others. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Integral transform
- In mathematics, an integral transform maps a function from its original function space into another function space via integration, where some of the properties of the original function might be more easily characterized and manipulated than in the original function space. The transformed function can generally be mapped back to the original function space using the inverse transform. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">International System of Units
- The International System of Units (SI, abbreviated from the French Lua error: Internal error: The interpreter has terminated with signal "24".) is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world. It comprises a coherent system of units of measurement starting with seven base units, which are the second (the unit of time with the symbol s), metre (length, m), kilogram (mass, kg), ampere (electric current, A), kelvin (thermodynamic temperature, K), mole (amount of substance, mol), and candela (luminous intensity, cd). The system allows for an unlimited number of additional units, called derived units, which can always be represented as products of powers of the base units.<ref group="Note">For example, the SI unit of velocity is the metre per second, m⋅s−1; of acceleration is the metre per second squared, m⋅s−2; etc.</ref> Twenty-two derived units have been provided with special names and symbols.<ref group="Note">For example the newton (N), the unit of force, equivalent to kg⋅m⋅s−2; the joule (J), the unit of energy, equivalent to kg⋅m2⋅s−2, etc. The most recently named derived unit, the katal, was defined in 1999.</ref> The seven base units and the 22 derived units with special names and symbols may be used in combination to express other derived units,<ref group="Note">For example, the recommended unit for the electric field strength is the volt per metre, V/m, where the volt is the derived unit for electric potential difference. The volt per metre is equal to kg⋅m⋅s−3⋅A−1 when expressed in terms of base units.</ref> which are adopted to facilitate measurement of diverse quantities. The SI system also provides twenty prefixes to the unit names and unit symbols that may be used when specifying power-of-ten (i.e. decimal) multiples and sub-multiples of SI units. The SI is intended to be an evolving system; units and prefixes are created and unit definitions are modified through international agreement as the technology of measurement progresses and the precision of measurements improves. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Interval estimation
- In statistics, interval estimation is the use of sample data to calculate an interval of possible values of an unknown population parameter; this is in contrast to point estimation, which gives a single value. Jerzy Neyman (1937) identified interval estimation ("estimation by interval") as distinct from point estimation ("estimation by unique estimate"). In doing so, he recognized that then-recent work quoting results in the form of an estimate plus-or-minus a standard deviation indicated that interval estimation was actually the problem statisticians really had in mind. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Inorganic chemistry
- Deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ion
- Is a particle, atom or molecule with a net electrical charge. The charge of the electron is considered negative by convention. The negative charge of an ion is equal and opposite to charged proton(s) considered positive by convention. The net charge of an ion is non-zero due to its total number of electrons being unequal to its total number of protons. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ionic bonding
- Is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities,<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding along with covalent bonding and metallic bonding. Ions are atoms (or groups of atoms) with an electrostatic charge. Atoms that gain electrons make negatively charged ions (called anions). Atoms that lose electrons make positively charged ions (called cations). This transfer of electrons is known as electrovalence in contrast to covalence. In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be of a more complex nature, e.g. molecular ions like NHLua error: Internal error: The interpreter has terminated with signal "24". or SOLua error: Internal error: The interpreter has terminated with signal "24".. In simpler words, an ionic bond results from the transfer of electrons from a metal to a non-metal in order to obtain a full valence shell for both atoms. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Ionization
- Ionization or ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Isotope
- Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
J
-
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">J/psi meson
- The Lua error: Internal error: The interpreter has terminated with signal "24". (J/psi) meson Lua error: Internal error: The interpreter has terminated with signal "24". or psion<ref>Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".</ref> is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium". The Lua error: Internal error: The interpreter has terminated with signal "24". is the most common form of charmonium, due to its spin of 1 and its low rest mass. The Lua error: Internal error: The interpreter has terminated with signal "24". has a rest mass of Lua error: Internal error: The interpreter has terminated with signal "24"., just above that of the Lua error: Internal error: The interpreter has terminated with signal "24". (Lua error: Internal error: The interpreter has terminated with signal "24".), and a mean lifetime of Lua error: Internal error: The interpreter has terminated with signal "24".. This lifetime was about a thousand times longer than expected.<ref> Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Joule
- The SI unit of energy. The joule, (symbol: J), is a derived unit of energy in the International System of Units.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> It is equal to the energy transferred to (or work done on) an object when a force of one newton acts on that object in the direction of the object's motion through a distance of one metre (1 newton-metre or N⋅m). It is also the energy dissipated as heat when an electric current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889).<ref>American Heritage Dictionary of the English Language, Online Edition (2009). Houghton Mifflin Co., hosted by Yahoo! Education.</ref><ref>The American Heritage Dictionary, Second College Edition (1985). Boston: Houghton Mifflin Co., p. 691.</ref><ref>McGraw-Hill Dictionary of Physics, Fifth Edition (1997). McGraw-Hill, Inc., p. 224.</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Joule heating
- Also known as resistive, resistance, or Ohmic heating, is the process by which the passage of an electric current through a conductor produces heat.
K
-
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Kalman filter
- In statistics and control theory, Kalman filtering, also known as linear quadratic estimation (LQE), is an algorithm that uses a series of measurements observed over time, containing statistical noise and other inaccuracies, and produces estimates of unknown variables that tend to be more accurate than those based on a single measurement alone, by estimating a joint probability distribution over the variables for each timeframe. The Kalman filter has numerous applications in technology. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Kelvin
- Is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. The kelvin (symbol: K) is the base unit of temperature in the International System of Units (SI). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Kelvin–Planck statement
- (Or the Heat Engine Statement), of the second law of thermodynamics states that it is impossible to devise a cyclically operating heat engine, the effect of which is to absorb energy in the form of heat from a single thermal reservoir and to deliver an equivalent amount of work.<ref name="Rao">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> This implies that it is impossible to build a heat engine that has 100% thermal efficiency.<ref name="Young&Freedman">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Kinematics
- Is a branch of classical mechanics that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces that caused the motion.<ref name="Whittaker">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name=Beggs>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name=Wright>Lua error: Internal error: The interpreter has terminated with signal "24".</ref>
L
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<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Laminar flow
- In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing.<ref>Streeter, V.L. (1951-1966) Fluid Mechanics, Section 3.3 (4th edition). McGraw-Hill</ref> At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids.<ref name="Geankoplis, Christie John 2003">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> In laminar flow, the motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Laplace transform
- In mathematics, the Laplace transform, named after its inventor Pierre-Simon Laplace (Lua error: Internal error: The interpreter has terminated with signal "24".), is an integral transform that converts a function of a real variable <math>t</math> (often time) to a function of a complex variable <math>s</math> (complex frequency). The transform has many applications in science and engineering because it is a tool for solving differential equations. In particular, it transforms differential equations into algebraic equations and convolution into multiplication.<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">LC circuit
- A circuit consisting entirely of inductors (L) and capacitors (C). <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Le Chatelier's principle
- Le Chatelier's principle, also called Chatelier's principle, is a principle of chemistry used to predict the effect of a change in conditions on chemical equilibria. The principle is named after French chemist Henry Louis Le Chatelier, and sometimes also credited to Karl Ferdinand Braun, who discovered it independently. It can be stated as:
Lua error: Internal error: The interpreter has terminated with signal "24".When any system at equilibrium for a long period of time is subjected to a change in concentration, temperature, volume, or pressure, (1) the system changes to a new equilibrium, and (2) this change partly counteracts the applied change.
It is common to treat the principle as a more general observation of systems,<ref name="Systemantics">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> such as
Lua error: Internal error: The interpreter has terminated with signal "24".When a settled system is disturbed, it will adjust to diminish the change that has been made to it
or, "roughly stated",<ref name="Systemantics"/>
Lua error: Internal error: The interpreter has terminated with signal "24".Any change in status quo prompts an opposing reaction in the responding system.
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Lenz's law - Lenz's law, named after the physicist Emil Lenz who formulated it in 1834,<ref>Lenz, E. (1834), "Ueber die Bestimmung der Richtung der durch elektodynamische Vertheilung erregten galvanischen Ströme", Annalen der Physik und Chemie, 107 (31), pp. 483–494. A partial translation of the paper is available in Magie, W. M. (1963), A Source Book in Physics, Harvard: Cambridge MA, pp. 511–513.</ref> states that the direction of the electric current which is induced in a conductor by a changing magnetic field is such that the magnetic field created by the induced current opposes the initial changing magnetic field. It is a qualitative law that specifies the direction of induced current, but states nothing about its magnitude. Lenz's law explains the direction of many effects in electromagnetism, such as the direction of voltage induced in an inductor or wire loop by a changing current, or the drag force of eddy currents exerted on moving objects in a magnetic field. Lenz's law may be seen as analogous to Newton's third law in classical mechanics.<ref name="Electromagnetics explained: a handbook for wireless/RF, EMC, and high-speed electronics">Schmitt, Ron. Electromagnetics explained. 2002. Retrieved 16 July 2010.</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Lepton
- In particle physics, a lepton is an elementary particle of half-integer spin (spin 1⁄2) that does not undergo strong interactions.<ref> Lua error: Internal error: The interpreter has terminated with signal "24".</ref> Two main classes of leptons exist: charged leptons (also known as the electron-like leptons), and neutral leptons (better known as neutrinos). Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. The best known of all leptons is the electron. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Lever
- Is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">L'Hôpital's rule
- In mathematics, more specifically calculus, L'Hôpital's rule or L'Hospital's rule (Lua error: Internal error: The interpreter has terminated with signal "24".,
Lua error: Internal error: The interpreter has terminated with signal "24"., Lua error: Internal error: The interpreter has terminated with signal "24".) provides a technique to evaluate limits of indeterminate forms. Application (or repeated application) of the rule often converts an indeterminate form to an expression that can be easily evaluated by substitution. The rule is named after the 17th-century French mathematician Guillaume de l'Hôpital. Although the rule is often attributed to L'Hôpital, the theorem was first introduced to him in 1694 by the Swiss mathematician Johann Bernoulli.
L'Hôpital's rule states that for functions f and g which are differentiable on an open interval I except possibly at a point c contained in I, if <math>\lim_{x\to c}f(x)=\lim_{x\to c}g(x)=0 \text{ or } \pm\infty,</math> and <math>g'(x)\ne 0</math> for all x in I with x ≠ cLua error: Internal error: The interpreter has terminated with signal "24"., and <math>\lim_{x\to c}\frac{f'(x)}{g'(x)}</math> exists, then
- <math>\lim_{x\to c}\frac{f(x)}{g(x)} = \lim_{x\to c}\frac{f'(x)}{g'(x)}.</math>
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Light - Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye.<ref>CIE (1987). International Lighting Vocabulary Lua error: Internal error: The interpreter has terminated with signal "24".. Number 17.4. CIE, 4th edition. Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24".Lua error: Internal error: The interpreter has terminated with signal "24"..
By the International Lighting Vocabulary, the definition of light is: "Any radiation capable of causing a visual sensation directly."</ref> Visible light is usually defined as having wavelengths in the range of 400–700 nm, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths).<ref name="Pal2001">Lua error: Internal error: The interpreter has terminated with signal "24".</ref><ref name="BuserImbert1992">Lua error: Internal error: The interpreter has terminated with signal "24".</ref> This wavelength means a frequency range of roughly 430–750 terahertz (THz).
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Linear actuator - Is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Linear algebra
- The mathematics of equations where the unknowns are only in the first power. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Linear elasticity
- Is a mathematical model of how solid objects deform and become internally stressed due to prescribed loading conditions. It is a simplification of the more general nonlinear theory of elasticity and a branch of continuum mechanics. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Liquid
- A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena. Water is, by far, the most common liquid on Earth. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Logarithm
- In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a given number x is the exponent to which another fixed number, the base b, must be raised, to produce that number x. In the simplest case, the logarithm counts the number of occurrences of the same factor in repeated multiplication; e.g., since 1000 = 10 × 10 × 10 = 103Lua error: Internal error: The interpreter has terminated with signal "24"., the "logarithm base 10Lua error: Internal error: The interpreter has terminated with signal "24"." of 1000Lua error: Internal error: The interpreter has terminated with signal "24". is 3Lua error: Internal error: The interpreter has terminated with signal "24"., or log10(1000) = 3Lua error: Internal error: The interpreter has terminated with signal "24".. The logarithm of x to base b is denoted as logb(x)Lua error: Internal error: The interpreter has terminated with signal "24"., or without parentheses, logb xLua error: Internal error: The interpreter has terminated with signal "24"., or even without the explicit base, log xLua error: Internal error: The interpreter has terminated with signal "24"., when no confusion is possible, or when the base does not matter such as in big O notation.
More generally, exponentiation allows any positive real number as base to be raised to any real power, always producing a positive result, so logb(x)Lua error: Internal error: The interpreter has terminated with signal "24". for any two positive real numbers b and x, where b is not equal to 1Lua error: Internal error: The interpreter has terminated with signal "24"., is always a unique real number y. More explicitly, the defining relation between exponentiation and logarithm is:
- <math> \log_b(x) = y \ </math> exactly if <math>\ b^y = x\ </math> and <math>\ x > 0</math> and <math>\ b > 0</math> and <math>\ b \ne 1</math>.
<dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Logarithmic identities - Several important formulas, sometimes called logarithmic identities or log laws, relate logarithms to one another.<ref>All statements in this section can be found in Lua error: Internal error: The interpreter has terminated with signal "24"., Lua error: Internal error: The interpreter has terminated with signal "24"., or Lua error: Internal error: The interpreter has terminated with signal "24"., for example.</ref> <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Logarithmic mean temperature difference
- (Also known as log mean temperature difference, LMTD) is used to determine the temperature driving force for heat transfer in flow systems, most notably in heat exchangers. The LMTD is a logarithmic average of the temperature difference between the hot and cold feeds at each end of the double pipe exchanger. For a given heat exchanger with constant area and heat transfer coefficient, the larger the LMTD, the more heat is transferred. The use of the LMTD arises straightforwardly from the analysis of a heat exchanger with constant flow rate and fluid thermal properties. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Lumped capacitance model
- A lumped-capacitance model, also called lumped system analysis,<ref>Lua error: Internal error: The interpreter has terminated with signal "24".</ref> reduces a thermal system to a number of discrete "lumps" and assumes that the temperature difference inside each lump is negligible. This approximation is useful to simplify otherwise complex differential heat equations. It was developed as a mathematical analog of electrical capacitance, although it also includes thermal analogs of electrical resistance as well. <dt class="glossary " id="Lua error: Internal error: The interpreter has terminated with signal "24"." style="margin-top: 0.4em;">Lumped element model
- The lumped-element model (also called lumped-parameter model, or lumped-component model) simplifies the description of the behaviour of spatially distributed physical systems into a topology consisting of discrete entities that approximate the behaviour of the distributed system under certain assumptions. It is useful in electrical systems (including electronics), mechanical multibody systems, heat transfer, acoustics, etc. Mathematically speaking, the simplification reduces the state space of the system to a finite dimension, and the partial differential equations (PDEs) of the continuous (infinite-dimensional) time and space model of the physical system into ordinary differential equations (ODEs) with a finite number of parameters.
M–Z
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See also
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- Engineering
- National Council of Examiners for Engineering and Surveying
- Fundamentals of Engineering Examination
- Principles and Practice of Engineering Examination
- Graduate Aptitude Test in Engineering
- Glossary of aerospace engineering
- Glossary of civil engineering
- Glossary of electrical and electronics engineering
- Glossary of mechanical engineering
- Glossary of structural engineering
- Glossary of architecture
- Glossary of areas of mathematics
- Glossary of artificial intelligence
- Glossary of astronomy
- Glossary of biology
- Glossary of calculus
- Glossary of chemistry
- Glossary of ecology
- Glossary of economics
- Glossary of physics
- Glossary of probability and statistics
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Notes
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References
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Works cited
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