Glossary of engineering: M–Z

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See also: Glossary of engineering: A–L

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.

Engineering

M

Euler-Bernoulli beams
. Use of Macaulay's technique is very convenient for cases of discontinuous and/or discrete loading. Typically partial uniformly distributed loads (u.d.l.) and uniformly varying loads (u.v.l.) over the span and a number of concentrated loads are conveniently handled using this technique.
Mach number
The ratio of the speed of an object to the speed of sound.
mechanical systems
.
jump, or an arithmetic logic unit (ALU) operation on one or more units of data in the CPU's registers or memory
.
Machine element
Or hardware, refers to an elementary component of a machine. These elements consist of three basic types:
  1. structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,
  2. mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and
  3. control components such as buttons, switches, indicators, sensors, actuators and computer controllers.[1]
While generally not considered to be a machine element, the shape, texture and color of covers are an important part of a machine that provide a styling and operational interface between the mechanical components of a machine and its users. Machine elements are basic mechanical parts and features used as the building blocks of most machines.[2] Most are standardized to common sizes, but customs are also common for specialized applications.[3]
training data", in order to make predictions or decisions without being explicitly programmed to do so.[5] Machine learning algorithms are used in a wide variety of applications, such as in medicine, email filtering, speech recognition, and computer vision, where it is difficult or unfeasible to develop conventional algorithms to perform the needed tasks.[6]
Maclaurin series
In mathematics, the Taylor series of a function is an infinite sum of terms that are expressed in terms of the function's derivatives at a single point. For most common functions, the function and the sum of its Taylor series are equal near this point. Taylor's series are named after Brook Taylor, who introduced them in 1715. If zero is the point where the derivatives are considered, a Taylor series is also called a Maclaurin series, after Colin Maclaurin
, who made extensive use of this special case of Taylor series in the 18th century.
ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a magnetic field that varies with location will exert a force on a range of non-magnetic materials by affecting the motion of their outer atomic electrons. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, they are described as a map assigning a vector to each point of space or, more precisely—because of the way the magnetic field transforms under mirror reflection—as a field of pseudovectors
. In
electromagnetics, the term "magnetic field" is used for two distinct but closely related vector fields denoted by the symbols B and H. In the International System of Units, H, magnetic field strength, is measured in the SI base units of ampere per meter (A/m).[10] B, magnetic flux density, is measured in tesla (in SI base units: kilogram per second2 per ampere),[11] which is equivalent to newton per meter per ampere. H and B differ in how they account for magnetization. In vacuum, the two fields are related through the vacuum permeability
, ; but in a magnetized material, the terms differ by the material's magnetization at each point.
ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt and nickel and their alloys. The rare-earth metals neodymium and samarium are less common examples. The prefix ferro- refers to iron, because permanent magnetism was first observed in lodestone, a form of natural iron ore called magnetite
, Fe3O4.
Manufacturing engineering
Is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering. Manufacturing engineering requires the ability to plan the practices of manufacturing; to research and to develop tools, processes, machines and equipment; and to integrate the facilities and systems for producing quality products with the optimum expenditure of capital.[12] The manufacturing or production engineer's primary focus is to turn raw material into an updated or new product in the most effective, efficient & economic way possible.
conservation law used in the analysis of the system depends on the context of the problem, but all revolve around mass conservation, i.e., that matter cannot disappear or be created spontaneously.[13]
: 59–62 
rho), although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume:[14]
where ρ is the density, m is the mass, and V is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume,[15] although this is scientifically inaccurate – this quantity is more specifically called specific weight.
Mass moment of inertia
The moment of inertia, otherwise known as the mass moment of inertia, angular mass, second moment of mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular acceleration about a rotational axis, akin to how mass determines the force needed for a desired acceleration
. It depends on the body's mass distribution and the axis chosen, with larger moments requiring more torque to change the body's rate of rotation.
atomic mass units. Since protons and neutrons are both baryons, the mass number A is identical with the baryon number B of the nucleus (and also of the whole atom or ion). The mass number is different for each different isotope of a chemical element. Hence, the difference between the mass number and the atomic number Z gives the number of neutrons (N) in a given nucleus: N = A − Z.[17]
The mass number is written either after the element name or as a
superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or 12
C
, which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number (Z) as a subscript to the left of the element symbol directly below the mass number: 12
6C
.[18]
Mass spectrometry
(MS), is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are typically presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures.
ductile failure (yield). Depending on the conditions (such as temperature, state of stress
, loading rate) most materials can fail in a brittle or ductile manner or both. However, for most practical situations, a material may be classified as either brittle or ductile. In mathematical terms, failure theory is expressed in the form of various failure criteria which are valid for specific materials. Failure criteria are functions in stress or strain space which separate "failed" states from "unfailed" states. A precise physical definition of a "failed" state is not easily quantified and several working definitions are in use in the engineering community. Quite often, phenomenological failure criteria of the same form are used to predict brittle failure and ductile yields.
materials selection
.
Materials science
The interdisciplinary field of materials science, also commonly termed materials science and engineering, covers the design and discovery of new materials, particularly solids. The intellectual origins of materials science stem from the Enlightenment, when researchers began to use analytical thinking from chemistry, physics, and engineering to understand ancient, phenomenological observations in metallurgy and mineralogy.[19][20] Materials science still incorporates elements of physics, chemistry, and engineering. As such, the field was long considered by academic institutions as a sub-field of these related fields. Beginning in the 1940s, materials science began to be more widely recognized as a specific and distinct field of science and engineering, and major technical universities around the world created dedicated schools for its study. Materials scientists emphasize understanding, how the history of a material (processing) influences its structure, and thus the material's properties and performance. The understanding of processing-structure-properties relationships is called the materials paradigm. This paradigm is used to advance understanding in a variety of research areas, including nanotechnology, biomaterials, and metallurgy. Materials science is also an important part of forensic engineering and failure analysis – investigating materials, products, structures or components, which fail or do not function as intended, causing personal injury or damage to property. Such investigations are key to understanding, for example, the causes of various aviation accidents and incidents.
Mathematical optimization
Mathematical optimization (alternatively spelled optimisation) or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives.[21] Optimization problems of sorts arise in all quantitative disciplines from computer science and engineering to operations research and economics, and the development of solution methods has been of interest in mathematics for centuries.[22] In the simplest case, an
maximizing or minimizing a real function by systematically choosing input values from within an allowed set and computing the value of the function. The generalization of optimization theory and techniques to other formulations constitutes a large area of applied mathematics. More generally, optimization includes finding "best available" values of some objective function given a defined domain
(or input), including a variety of different types of objective functions and different types of domains.
Mathematical physics
Refers to the development of mathematical methods for application to problems in physics. The Journal of Mathematical Physics defines the field as "the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories".[23]
Mathematics
Includes the study of such topics as quantity (number theory),[24] structure (algebra),[25] space (geometry),[24] and change (analysis).[26][27][28] It has no generally accepted definition.[29][30]
written records exist. The research
required to solve mathematical problems can take years or even centuries of sustained inquiry.
Matrix
In mathematics, a matrix (plural matrices) is a rectangular array or table of numbers, symbols, or expressions, arranged in rows and columns, which is used to represent a mathematical object or a property of such an object. For example,
is a matrix with two rows and three columns; one say often a "two by three matrix", a "2×3-matrix", or a matrix of dimension 2×3. Without further specifications, matrices represent
linear maps, and allow explicit computations in linear algebra. Therefore, the study of matrices is a large part of linear algebra, and most properties and operations of abstract linear algebra can be expressed in terms of matrices. For example, matrix multiplication represents composition
of linear maps. Not all matrices are related to linear algebra. This is in particular the case, in graph theory, of incidence matrices and adjacency matrices.[33]
rest mass and volume. However it does not include massless particles such as photons, or other energy phenomena or waves such as light.[34]: 21 [35] Matter exists in various states (also known as phases). These include classical everyday phases such as solid, liquid, and gas – for example water exists as ice, liquid water, and gaseous steam – but other states are possible, including plasma, Bose–Einstein condensates, fermionic condensates, and quark–gluon plasma.[36]
Maximum-distortion energy theory
.
Maximum-normal-stress theory
.
Maximum shear stress
.
electric circuits
. The equations provide a mathematical model for electric, optical, and radio technologies, such as power generation, electric motors, wireless communication, lenses, radar etc. They describe how electric and magnetic fields are generated by charges, currents, and changes of the fields.[note 1] The equations are named after the physicist and mathematician James Clerk Maxwell, who, in 1861 and 1862, published an early form of the equations that included the Lorentz force law. Maxwell first used the equations to propose that light is an electromagnetic phenomenon. An important consequence of Maxwell's equations is that they demonstrate how fluctuating electric and magnetic fields propagate at a constant speed (c) in vacuum. Known as electromagnetic radiation, these waves may occur at various wavelengths to produce a spectrum of light from radio waves to gamma rays.
Mean
There are several kinds of mean in mathematics, especially in statistics: For a data set, the arithmetic mean, also known as average or arithmetic average, is a central value of a finite set of numbers: specifically, the sum of the values divided by the number of values. The arithmetic mean of a set of numbers x1, x2, ..., xn is typically denoted by [note 2]. If the data set were based on a series of observations obtained by sampling from a statistical population, the arithmetic mean is the sample mean (denoted ) to distinguish it from the mean, or expected value, of the underlying distribution, the population mean (denoted or [note 3]).[37] In
discrete probability distribution
of a random variable X, the mean is equal to the sum over every possible value weighted by the probability of that value; that is, it is computed by taking the product of each possible value x of X and its probability p(x), and then adding all these products together, giving .
continuous probability distribution. Not every probability distribution has a defined mean (see the Cauchy distribution
for an example). Moreover, the mean can be infinite for some distributions. For a finite population, the population mean of a property is equal to the arithmetic mean of the given property, while considering every member of the population. For example, the population mean height is equal to the sum of the heights of every individual—divided by the total number of individuals. The sample mean may differ from the population mean, especially for small samples. The law of large numbers states that the larger the size of the sample, the more likely it is that the sample mean will be close to the population mean.[41] Outside probability and statistics, a wide range of other notions of mean are often used in geometry and mathematical analysis.
averages. The term central tendency dates from the late 1920s.[43]
The most common measures of central tendency are the arithmetic mean, the median, and the mode. A middle tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution. Occasionally authors use central tendency to denote "the tendency of quantitative data to cluster around some central value."[43][44] The central tendency of a distribution is typically contrasted with its dispersion or variability; dispersion and central tendency are the often characterized properties of distributions. Analysis may judge whether data has a strong or a weak central tendency based on its dispersion.
mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the law of the lever. Machine components designed to manage forces and movement in this way are called mechanisms.[45]
An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal mechanism does not include a power source, is frictionless, and is constructed from
rigid bodies
that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal.
mechanical systems.[46] It is one of the oldest and broadest of the engineering branches
.
Mechanical filter
Is a signal processing filter usually used in place of an electronic filter at radio frequencies. Its purpose is the same as that of a normal electronic filter: to pass a range of signal frequencies, but to block others. The filter acts on mechanical vibrations which are the analogue of the electrical signal. At the input and output of the filter, transducers convert the electrical signal into, and then back from, these mechanical vibrations.
Mechanical wave
Is a wave that is an oscillation of matter, and therefore transfers energy through a medium.[47] While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves transport energy. This energy propagates in the same direction as the wave. Any kind of wave (mechanical or electromagnetic) has a certain energy. Mechanical waves can be produced only in media which possess elasticity and inertia.
displacements
, or changes of an object's position relative to its environment. This branch of
Galileo, Kepler, and Newton laid the foundation for what is now known as classical mechanics
. It is a branch of classical physics that deals with particles that are either at rest or are moving with velocities significantly less than the speed of light. It can also be defined as a branch of science which deals with the motion of and forces on bodies not in the quantum realm. The field is today less widely understood in terms of quantum theory.
Mechanism
Is a device that transforms input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components which may include:
breakdown point
of 50%: so long as no more than half the data are contaminated, the median is not an arbitrarily large or small result.
Melting
Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid.
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."[52]
femtometer (1×10−15 m),[53] which is about 0.6 times the size of a proton or neutron. All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond. Heavier mesons decay to lighter mesons and ultimately to stable electrons, neutrinos and photons
.
thermal and electrical resistivity and conductivity, opacity, and luster.[54][55][56][57]
Metallic bonding is not the only type of
mercurous ion
(Hg2+
2).
Middle-out
A combination of top-down and bottom-up design.[58]
sample (statistics) defined as the arithmetic mean of the maximum and minimum values of the data set:[59]
The mid-range is closely related to the range, a measure of statistical dispersion defined as the difference between maximum and minimum values. The two measures are complementary in sense that if one knows the mid-range and the range, one can find the sample maximum and minimum values. The mid-range is rarely used in practical statistical analysis, as it lacks efficiency as an estimator for most distributions of interest, because it ignores all intermediate points, and lacks robustness, as outliers change it significantly. Indeed, it is one of the least efficient and least robust statistics. However, it finds some use in special cases: it is the maximally efficient estimator for the center of a uniform distribution, trimmed mid-ranges address robustness, and as an L-estimator, it is simple to understand and compute.
Midhinge
In statistics, the midhinge is the average of the first and third quartiles and is thus a measure of location. Equivalently, it is the 25%
midsummary; it is an L-estimator
.
The midhinge is related to the interquartile range (IQR), the difference of the third and first quartiles (i.e. ), which is a measure of statistical dispersion. The two are complementary in sense that if one knows the midhinge and the IQR, one can find the first and third quartiles. The use of the term "hinge" for the lower or upper quartiles derives from John Tukey's work on exploratory data analysis in the late 1970s,[60] and "midhinge" is a fairly modern term dating from around that time. The midhinge is slightly simpler to calculate than the trimean (), which originated in the same context and equals the average of the median () and the midhinge.
Mining engineering
Mining in the engineering discipline is the extraction of minerals from underneath, above or on the ground. Mining engineering is associated with many other disciplines, such as mineral processing, exploration, excavation, geology, and metallurgy, geotechnical engineering and surveying. A mining engineer may manage any phase of mining operations, from exploration and discovery of the mineral resources, through feasibility study, mine design, development of plans, production and operations to mine closure.
Miller indices
Miller indices form a notation system in crystallography for planes in crystal (Bravais) lattices
. In particular, a family of lattice planes is determined by three integers h, k, and ℓ, the Miller indices. They are written (hkℓ), and denote the family of planes orthogonal to , where are the basis of the reciprocal lattice vectors (note that the plane is not always orthogonal to the linear combination of direct lattice vectors because the lattice vectors need not be mutually orthogonal). By convention,
negative integers are written with a bar, as in 3 for −3. The integers are usually written in lowest terms, i.e. their greatest common divisor should be 1. Miller indices are also used to designate reflections in X-ray crystallography
. In this case the integers are not necessarily in lowest terms, and can be thought of as corresponding to planes spaced such that the reflections from adjacent planes would have a phase difference of exactly one wavelength (2π), regardless of whether there are atoms on all these planes or not. There are also several related notations:[61]
  • the notation {hkℓ} denotes the set of all planes that are equivalent to (hkℓ) by the symmetry of the lattice.
In the context of crystal directions (not planes), the corresponding notations are:
  • [hkℓ], with square instead of round brackets, denotes a direction in the basis of the direct lattice vectors instead of the reciprocal lattice; and
  • similarly, the notation <hkℓ> denotes the set of all directions that are equivalent to [hkℓ] by symmetry.
information engineering.[63]
Mobile robots have the capability to move around in their environment and are not fixed to one physical location. Mobile robots can be "autonomous" (AMR -
jointed arm (multi-linked manipulator) and gripper assembly (or end effector
), attached to a fixed surface. The joint-arm are controlled by linear actuator or servo motor or stepper motor.
Mode
The mode is the value that appears most often in a set of data values.[66] If X is a discrete random variable, the mode is the value x (i.e., X = x) at which the probability mass function takes its maximum value. In other words, it is the value that is most likely to be sampled. Like the statistical
skewed distributions
.
Modulus of elasticity
An elastic modulus (also known as modulus of elasticity) is a quantity that measures an object or substance's resistance to being deformed elastically (i.e., non-permanently) when a stress is applied to it. The elastic modulus of an object is defined as the slope of its stress–strain curve in the elastic deformation region:[67]
A stiffer material will have a higher elastic modulus. An elastic modulus has the form:
where
strain
 is the ratio of the change in some parameter caused by the deformation to the original value of the parameter. Since strain is a dimensionless quantity, the units of will be the same as the units of stress.[68]
Mohr's circle
A graphical method of analyzing the three-dimensional stresses in a system that has a loading force applied to it.
molarity which is based on a specified volume
of solution. A commonly used unit for molality in chemistry is mol/kg. A solution of concentration 1 mol/kg is also sometimes denoted as 1 molal. The unit mol/kg requires that molar mass be expressed in kg/mol, instead of the usual g/mol or kg/kmol.
intrinsic property of the species. The SI unit of molar attenuation coefficient is the square metre per mole (m2/mol), but in practice, quantities are usually expressed in terms of M−1⋅cm−1 or L⋅mol−1⋅cm−1 (the latter two units are both equal to 0.1 m2/mol). In older literature, the cm2/mol is sometimes used; 1 M−1⋅cm−1 equals 1000 cm2/mol. The molar attenuation coefficient is also known as the molar extinction coefficient and molar absorptivity, but the use of these alternative terms has been discouraged by the IUPAC.[69][70]
italicized M are also used in journals and textbooks.[71]
Molar mass
In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles.[72] It is the mass of 1 mole of the substance or 6.022×1023 particles, expressed in grams. The molar mass is a bulk, not molecular, property of a substance. The molar mass is an average of many instances of the compound, which often vary in mass due to the presence of isotopes. Most commonly, the molar mass is computed from the standard atomic weights and is thus a terrestrial average and a function of the relative abundance of the isotopes of the constituent atoms on Earth. The molar mass is appropriate for converting between the mass of a substance and the amount of a substance for bulk quantities.
Commonwealth English; see spelling differences) is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix.[73]
This itself may have been made using a pattern or model of the final object.
electrical charge
. In
quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and molecule is often used when referring to polyatomic ions
. In the
noble gases are individual atoms.[79]
A molecule may be
water
(two hydrogen atoms and one oxygen atom; H2O). Atoms and complexes connected by
ionic bonds, are typically not considered single molecules.[80]
Molecular physics
Is the study of the physical properties of molecules, the chemical bonds between atoms as well as the molecular dynamics. Its most important experimental techniques are the various types of spectroscopy; scattering is also used. The field is closely related to atomic physics and overlaps greatly with theoretical chemistry, physical chemistry and chemical physics.[81]
Moment of inertia
The moment of inertia, otherwise known as the mass moment of inertia, angular mass, second moment of mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular acceleration about a rotational axis, akin to how mass determines the force needed for a desired acceleration. It depends on the body's mass distribution and the axis chosen, with larger moments requiring more torque to change the body's rate of rotation.
rotational
displacements.
optimization methods to solve design
problems incorporating a number of disciplines. It is also known as multidisciplinary system design optimization (MSDO). MDO allows designers to incorporate all relevant disciplines simultaneously. The optimum of the simultaneous problem is superior to the design found by optimizing each discipline sequentially, since it can exploit the interactions between the disciplines. However, including all disciplines simultaneously significantly increases the complexity of the problem.
Mutual inductance
Is the ratio between the electromotive force induced in one loop or coil by the rate of change of current in another loop or coil. Mutual inductance is given the symbol M.
Muon
The muon, from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a [[spin-1⁄2|spin of]] 1/2, but with a much greater mass. It is classified as a lepton. As with other leptons, the muon is not known to have any sub-structure – that is, it is not thought to be composed of any simpler particles. The muon is an unstable
electromagnetic interaction), and because the mass difference between the muon and the set of its decay products is small, providing few kinetic degrees of freedom for decay. Muon decay almost always produces at least three particles, which must include an electron of the same charge as the muon and two types of neutrinos
.

N

nanoscale. It derives its name from the nanometre, a unit of measurement equalling one billionth of a meter. Nanoengineering is largely a synonym for nanotechnology
, but emphasizes the engineering rather than the pure science aspects of the field.
Nanotechnology
The technology of systems built with moving parts on the order of a nanometre in size.
viscous fluid substances, named after French engineer and physicist Claude-Louis Navier and Anglo-Irish physicist and mathematician George Gabriel Stokes
.
rest mass is so small (-ino) that it was long thought to be zero. The mass of the neutrino is much smaller than that of the other known elementary particles.[84] The weak force has a very short range, the gravitational interaction is extremely weak, and neutrinos do not participate in the strong interaction.[85] Thus, neutrinos typically pass through normal matter unimpeded and undetected.[86][83]
compression
or expansion, respectively.
reactive impedances
as well as resistances.
pipe. A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas
). Nozzles are frequently used to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that emerges from them. In a nozzle, the velocity of fluid increases at the expense of its pressure energy.
nth root
To put a number of function to the exponential power of 1/n.
Nuclear binding energy
The difference between the total mass energy of a nucleus and the mass energy of the isolated nucleons.
Nuclear engineering
The profession that deals with nuclear power.
released
.
Nuclear physics
The science that describes the components of atoms.
Nuclear potential energy
The energy that is given up in decay of an unstable nucleus.
Nuclear power
The use of energy derived from nuclear chain reactions for electricity production or ship propulsion.

O

Ohm
The SI unit of electrical resistance.
Ohm's law
A law describing the relationship between resistance, current, and voltage.
Optics
The study of light.
Organic chemistry
The study of carbon compounds.
Osmosis
The spontaneous movement of molecules or ions through a semi-permable membrane, tending to equalize concentration on both sides.

P

Parallel circuit
A circuit that begins and ends at the same node as another circuit.
divisible by two with no remainders left and its parity is odd if its remainder is 1.[91] For example, -4, 0, 82, and 178 are even because there is no remainder
when dividing it by 2. By contrast, -3, 5, 7, 21 are odd numbers as they leave a remainder of 1 when divided by 2.
coordinate. In three dimensions, it can also refer to the simultaneous flip in the sign of all three spatial coordinates (a point reflection
):
It can also be thought of as a test for chirality of a physical phenomenon, in that a parity inversion transforms a phenomenon into its mirror image. All fundamental interactions of elementary particles, with the exception of the weak interaction, are symmetric under parity. The weak interaction is chiral and thus provides a means for probing chirality in physics. In interactions that are symmetric under parity, such as electromagnetism in atomic and molecular physics, parity serves as a powerful controlling principle underlying quantum transitions. A matrix representation of P (in any number of dimensions) has determinant equal to −1, and hence is distinct from a rotation, which has a determinant equal to 1. In a two-dimensional plane, a simultaneous flip of all coordinates in sign is not a parity transformation; it is the same as a 180°-rotation. In quantum mechanics, wave functions that are unchanged by a parity transformation are described as even functions, while those that change sign under a parity transformation are odd functions.fn=A hydrocarbon compound, solid at room temperature.
magnetic permeability slightly greater than 1 (i.e., a small positive magnetic susceptibility) and hence are attracted to magnetic fields. The magnetic moment induced by the applied field is linear in the field strength and rather weak. It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer
.
Particle accelerator
Is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams.[94]
Particle displacement
Particle displacement or displacement amplitude is a measurement of distance of the movement of a sound particle from its equilibrium position in a medium as it transmits a sound wave.[95] The
air, the particle displacement is evident in the oscillations of air molecules with, and against, the direction in which the sound wave is travelling.[96]
protons, gas particles, or even household dust), particle physics usually investigates the irreducibly smallest detectable particles and the fundamental interactions necessary to explain their behaviour. In current understanding, these elementary particles are excitations of the quantum fields that also govern their interactions. The currently dominant theory explaining these fundamental particles and fields, along with their dynamics, is called the Standard Model. Thus, modern particle physics generally investigates the Standard Model and its various possible extensions, e.g. to the newest "known" particle, the Higgs boson, or even to the oldest known force field, gravity.[97][98]
Pascal's law
Pascal's law (also Pascal's principle[99][100][101] or the principle of transmission of fluid-pressure) is a principle in fluid mechanics that states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.[102] The law was established by French mathematician Blaise Pascal[103] in 1647–48.[104]
oscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called the period. The period depends on the length of the pendulum and also to a slight degree on the amplitude
, the width of the pendulum's swing.
upstream sector of the oil and gas industry. Exploration, by earth scientists, and petroleum engineering are the oil and gas industry's two main subsurface disciplines, which focus on maximizing economic recovery of hydrocarbons from subsurface reservoirs. Petroleum geology and geophysics
focus on provision of a static description of the hydrocarbon reservoir rock, while petroleum engineering focuses on estimation of the recoverable volume of this resource using a detailed understanding of the physical behavior of oil, water and gas within porous rock at very high pressure.
pH
A logarithmic measure of the concentration of hydrogen ions in an acid or base solution.
Phase (matter)
In the physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform.[107][108]: 86 [109]: 3  Examples of physical properties include density, index of refraction, magnetization and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air is a third phase over the ice and water. The glass of the jar is another separate phase. (See state of matter § Glass)
Phase (waves)
In physics and mathematics, the phase of a periodic function of some real variable (such as time) is an angle-like quantity representing the fraction of the cycle covered up to . It is denoted and expressed in such a
turn
as the variable goes through each
period
(and goes through each complete cycle). It may be
radians
, thus increasing by 360° or as the variable completes a full period.[110]
Phase diagram
A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions (pressure, temperature, volume, etc.) at which thermodynamically distinct phases (such as solid, liquid or gaseous states) occur and coexist at equilibrium.
Phase rule
In thermodynamics, the phase rule is a general principle governing "pVT" systems (that is, systems whose states are completely described by the variables pressure (p), volume (V) and temperature (T)) in thermodynamic equilibrium. If F is the number of degrees of freedom, C is the number of components and P is the number of phases, then[111][112]
It was derived by American physicist Josiah Willard Gibbs in his landmark paper titled On the Equilibrium of Heterogeneous Substances, published in parts between 1875 and 1878.[113] The rule assumes the components do not react with each other.
bosons
.
analytical dynamics and chemical equilibrium
.
Physical quantity
A physical quantity is a property of a material or system that can be quantified by measurement. A physical quantity can be expressed as a value, which is the algebraic multiplication of a numerical value and a unit. For example, the physical quantity mass can be quantified as n kg, where n is the numerical value and kg is the unit. A physical quantity possesses at least two characteristics in common. One is numerical magnitude and the other is the unit in which it is measured.
motion and behavior through space and time, and the related entities of energy and force.[115] Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.[c][116][117][118]
Planck constant
The Planck constant, or Planck's constant, is a fundamental physical constant denoted , and is of fundamental importance in quantum mechanics. A photon's energy is equal to its frequency multiplied by the Planck constant. Due to mass–energy equivalence, the Planck constant also relates mass to frequency. In
SI unit.[119]
The SI units are defined in such a way that, when the Planck constant is expressed in SI units, it has the exact value = 6.62607015×10−34 J⋅Hz−1.[120][121]
Plasma (physics)
Is one of the four fundamental states of matter, first systematically studied by Irving Langmuir in the 1920s.[122][123] It consists of a gas of ions – atoms or molecules which have one or more orbital electrons stripped (or, rarely, an extra electron attached), and free electrons.
Plasticity
In physics and materials science, plasticity, also known as plastic deformation, is the ability of a solid material to undergo permanent deformation, a non-reversible change of shape in response to applied forces.[124][125] For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the material itself. In engineering, the transition from elastic behavior to plastic behavior is known as yielding.
Pneumatics
The control of mechanical force and movement, generated by the application of compressed gas.
population mean). More formally, it is the application of a point estimator
to the data to obtain a point estimate. Point estimation can be contrasted with
credible intervals, in the case of Bayesian inference. More generally, a point estimator can be contrasted with a set estimator. Examples are given by confidence sets or credible sets. A point estimator can also be contrasted with a distribution estimator. Examples are given by confidence distributions, randomized estimators, and Bayesian posteriors
.
Polyphase system
An electrical system that uses a set of alternating currents at different phases.
SI unit of power is the watt, one joule per second
. Electric power is usually produced by
electric power grid
. Electric power can be delivered over long distances by
heat with high efficiency.[126]
Power (physics)
In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, power is sometimes called activity.[127][128][129] Power is a scalar quantity.
closed interval of −1 to 1. A power factor of less than one indicates the voltage and current are not in phase, reducing the average product of the two. Real power is the instantaneous product of voltage and current and represents the capacity of the electricity for performing work. Apparent power is the product of RMS
current and voltage. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power may be greater than the real power. A negative power factor occurs when the device (which is normally the load) generates power, which then flows back towards the source.
Gauge pressure (also spelled gage pressure)[d]
is the pressure relative to the ambient pressure. Various
centimetre of water, millimetre of mercury, and inch of mercury are used to express pressures in terms of the height of column of a particular fluid
in a manometer.
Probability
Is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates impossibility of the event and 1 indicates certainty.[note 4][131][132] The higher the probability of an event, the more likely it is that the event will occur. A simple example is the tossing of a fair (unbiased) coin. Since the coin is fair, the two outcomes ("heads" and "tails") are both equally probable; the probability of "heads" equals the probability of "tails"; and since no other outcomes are possible, the probability of either "heads" or "tails" is 1/2 (which could also be written as 0.5 or 50%).
Probability distribution
In probability theory and statistics, a probability distribution is the mathematical function that gives the probabilities of occurrence of different possible outcomes for an experiment.[133][134] It is a mathematical description of a random phenomenon in terms of its sample space and the probabilities of events (subsets of the sample space).[51] For instance, if X is used to denote the outcome of a coin toss ("the experiment"), then the probability distribution of X would take the value 0.5 (1 in 2 or 1/2) for X = heads, and 0.5 for X = tails (assuming that the coin is fair). Examples of random phenomena include the weather condition in a future date, the height of a randomly selected person, the fraction of male students in a school, the results of a survey to be conducted, etc.[135]
axioms. Typically these axioms formalise probability in terms of a probability space, which assigns a measure taking values between 0 and 1, termed the probability measure, to a set of outcomes called the sample space. Any specified subset of these outcomes is called an event
. Central subjects in probability theory include discrete and continuous
probability distributions, and stochastic processes, which provide mathematical abstractions of non-deterministic or uncertain processes or measured quantities
that may either be single occurrences or evolve over time in a random fashion. Although it is not possible to perfectly predict random events, much can be said about their behavior. Two major results in probability theory describing such behaviour are the law of large numbers and the central limit theorem. As a mathematical foundation for statistics, probability theory is essential to many human activities that involve quantitative analysis of data.[136] Methods of probability theory also apply to descriptions of complex systems given only partial knowledge of their state, as in statistical mechanics or sequential estimation. A great discovery of twentieth-century physics was the probabilistic nature of physical phenomena at atomic scales, described in quantum mechanics.[137][unreliable source?]
Process
Pulley
Is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley supported by a frame or shell that does not transfer power to a shaft, but is used to guide the cable or exert a force, the supporting shell is called a block, and the pulley may be called a sheave. A pulley may have a
groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain
.
Pump
Is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.[138] Pumps operate by some mechanism (typically
engines, or wind power
, and come in many sizes, from microscopic for use in medical applications, to large industrial pumps.

Q

electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved. QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons and represents the quantum counterpart of classical electromagnetism
giving a complete account of matter and light interaction.
physical models of subatomic particles and in condensed matter physics to construct models of quasiparticles
.
Quantum mechanics
Is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles.[140]: 1.1  It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science.

R

Regelation
The phenomena of melting under pressure, then freezing when the pressure is reduced.
water at its densest (at 4 °C or 39.2 °F); for gases, the reference is air at room temperature
(20 °C or 68 °F). The term "relative density" is often preferred in scientific usage.
Relative velocity
The relative velocity (also or ) is the velocity of an object or observer B in the rest frame of another object or observer A.
Reliability engineering
Is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time.[143] Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time.
meter (Ω⋅m).[144][145][146]
For example, if a 1 m × 1 m × 1 m solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is 1 Ω, then the resistivity of the material is 1 Ω⋅m.
electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators
. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.
turbulent. The turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow (eddy currents). These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation. Reynolds numbers are an important dimensionless quantity in fluid mechanics
.
Rheology
Is the study of the flow of matter, primarily in a liquid or gas state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force. Rheology is a branch of physics, and it is the science that deals with the deformation and flow of materials, both solids and liquids.[147]
molecules (consisting of the point masses: electrons and nuclei) are often seen as rigid bodies (see classification of molecules as rigid rotors
).
Robonaut
A development project conducted by NASA to create humanoid robots capable of using space tools and working in similar environments to suited astronauts.
minimally-invasive surgical procedures
and to enhance the capabilities of surgeons performing open surgery. In the case of robotically-assisted minimally-invasive surgery, instead of directly moving the instruments, the surgeon uses one of two methods to administer the instruments. These include using a direct telemanipulator or through computer control. A telemanipulator is a remote manipulator that allows the surgeon to perform the normal movements associated with the surgery. The robotic arms carry out those movements using end-effectors and manipulators to perform the actual surgery. In computer-controlled systems, the surgeon uses a computer to control the robotic arms and its end-effectors, though these systems can also still use telemanipulators for their input. One advantage of using the computerized method is that the surgeon does not have to be present, leading to the possibility for remote surgery.
bioengineering, computer engineering, control engineering, software engineering
, among others.
Root mean square
In mathematics and its applications, the root mean square (RMS or rms) is defined as the square root of the mean square (the arithmetic mean of the squares of a set of numbers).[150] The RMS is also known as the quadratic mean
root-mean-square deviation
of an estimator is a measure of the imperfection of the fit of the estimator to the data.
Root-mean-square speed
In the physics of gas molecules, the root-mean-square speed is defined as the square root of the average squared-speed. The RMS speed of an ideal gas is calculated
using the following equation:
where R represents the gas constant, 8.314 J/(mol·K), T is the temperature of the gas in kelvins, and M is the molar mass of the gas in kilograms per mole. In physics, speed is defined as the scalar magnitude of velocity. For a stationary gas, the average speed of its molecules can be in the order of thousands of km/h, even though the average velocity of its molecules is zero.
axis of rotation, the following dependence on the object's moment of inertia
is observed:
where
is the angular velocity
is the moment of inertia around the axis of rotation
is the kinetic energy
cycles per second (cps), radians per second (rad/s), etc.[153]
The symbol for rotational speed is [citation needed](the Greek lowercase letter "omega"). Tangential speed v, rotational speed , and radial distance r, are related by the following equation:[154]
An algebraic rearrangement of this equation allows us to solve for rotational speed:
Thus, the tangential speed will be directly proportional to r when all parts of a system simultaneously have the same ω, as for a wheel, disk, or rigid wand. The direct proportionality of v to r is not valid for the planets, because the planets have different rotational speeds (ω). Rotational speed can measure, for example, how fast a motor is running. Rotational speed and
angular speed are sometimes used as synonyms, but typically they are measured with a different unit. Angular speed, however, tells the change in angle per time unit, which is measured in radians per second
in the SI system. Since there are 2π radians per cycle, or 360 degrees per cycle, we can convert angular speed to rotational speed by
and
where
  • is rotational speed in cycles per second
  • is angular speed in radians per second
  • is angular speed in degrees per second
For example, a stepper motor might turn exactly one complete revolution each second. Its angular speed is 360 degrees per second (360°/s), or 2π radians per second (2π rad/s), while the rotational speed is 60 rpm. Rotational speed is not to be confused with tangential speed, despite some relation between the two concepts. Imagine a rotating merry-go-round. No matter how close or far you stand from the axis of rotation, your rotational speed will remain constant. However, your tangential speed does not remain constant. If you stand two meters from the axis of rotation, your tangential speed will be double the amount if you were standing only one meter from the axis of rotation.

S

Safe failure fraction (SFF)
A term used in functional safety for the proportion of failures that are either non-hazardous or detected automatically. The opposite of SFF is the proportion of undetected, hazardous failures.[155]
hazards
associated with a particular material or product, along with spill-handling procedures. The older MSDS formats could vary from source to source within a country depending on national requirements; however, the newer SDS format is internationally standardized.
potable water
.
Lewis base. The term is used in many contexts and for many classes of chemical compounds. Overall, saturated compounds are less reactive than unsaturated compounds. Saturation is derived from the Latin word saturare, meaning 'to fill')[157]
Scalar (mathematics)
.
Scalar (physics)
.
inner product
of two vectors (where the product is a scalar).
cylinder.[163]
Series circuit
An electrical circuit in which the same current passes through each component, with only one path.
Servo
A motor that moves to and maintains a set position under command, rather than continuously moving.
Servomechanism
An automatic device that uses error-sensing negative feedback to correct the performance of a mechanism.
Shadow matter
In physics, mirror matter, also called shadow matter or Alice matter, is a hypothetical counterpart to ordinary matter.[168]
Shear flow
The term shear flow is used in solid mechanics as well as in fluid dynamics. The expression shear flow is used to indicate:
  • a shear stress over a distance in a thin-walled structure (in solid mechanics);[169]
  • the flow induced by a force (in a fluid).
structural failure when the material or component fails in shear. A shear load is a force
that tends to produce a sliding failure on a material along a plane that is parallel to the direction of the force. When a paper is cut with scissors, the paper fails in shear. In
plates, or bolts). In a reinforced concrete beam, the main purpose of reinforcing bar (rebar) stirrups
is to increase the shear strength.
Normal stress, on the other hand, arises from the force vector component perpendicular
to the material cross section on which it acts.
near-infrared
(NIR) spectra. There is no standard cut-off for the near-infrared range; therefore, the shortwave radiation range is also variously defined. It may be broadly defined to include all radiation with a wavelength of 0.1μm and 5.0μm or narrowly defined so as to include only radiation between 0.2μm and 3.0μm. There is little radiation flux (in terms of
NIR arguably from 0.7μm to 5.0μm, beyond which the infrared is thermal.[170]
Shortwave radiation is distinguished from longwave radiation. Downward shortwave radiation is sensitive to solar zenith angle, cloud cover.[171]
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.[e] Twenty-two derived units have been provided with special names and symbols.[f] The seven base units and the 22 derived units with special names and symbols may be used in combination to express other derived units,[g] which are adopted to facilitate measurement of diverse quantities. The SI 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.
images, and scientific measurements.[172] Signal processing techniques can be used to improve transmission, storage efficiency and subjective quality and to also emphasize or detect components of interest in a measured signal.[173]
Simple machine
Is a mechanical device that changes the direction or magnitude of a force.[174] In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force.[175] Usually the term refers to the six classical simple machines that were defined by Renaissance scientists:[176][177][178]
Siphon
A closed tube that conveys liquids between two levels without pumping.
phase
changes, and other external or internal agents.
Solid-state physics
Is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms a theoretical basis of materials science. It also has direct applications, for example in the technology of transistors and semiconductors.
Solid solution strengthening
Is a type of alloying that can be used to improve the strength of a pure metal. The technique works by adding atoms of one element (the alloying element) to the crystalline lattice of another element (the base metal), forming a solid solution. The local nonuniformity in the lattice due to the alloying element makes plastic deformation more difficult by impeding dislocation motion through stress fields. In contrast, alloying beyond the solubility limit can form a second phase, leading to strengthening via other mechanisms (e.g. the precipitation of intermetallic compounds).
solute to dissolve in a solid, liquid or gaseous solvent. The solubility of a substance fundamentally depends on the physical and chemical properties of the solute and solvent as well as on temperature, pressure and presence of other chemicals (including changes to the pH) of the solution. The extent of the solubility of a substance in a specific solvent is measured as the saturation concentration
, where adding more solute does not increase the concentration of the solution and begins to precipitate the excess amount of solute.
Solubility equilibrium
Is a type of dynamic equilibrium that exists when a chemical compound in the solid state is in chemical equilibrium with a solution of that compound. The solid may dissolve unchanged, with dissociation or with chemical reaction with another constituent of the solution, such as acid or alkali. Each solubility equilibrium is characterized by a temperature-dependent solubility product which functions like an equilibrium constant. Solubility equilibria are important in pharmaceutical, environmental and many other scenarios.
Sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
Special relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates:[179][180][181]
  1. The
    laws of physics are invariant (that is, identical) in all inertial frames of reference (that is, frames of reference with no acceleration
    ).
  2. The speed of light in vacuum is the same for all observers, regardless of the motion of the light source or observer.
Specific heat
The amount of energy required to change the temperature of a unit mass of substance by one degree.
Specific gravity
The ratio between the mass density of a substance to that of water.
Specific volume
The volume of a unit mass of a substance.
Specific weight
The weight of a substance per unit volume.
autoignition.[182]
Stagnation pressure
In fluid dynamics, stagnation pressure (or pitot pressure) is the static pressure at a stagnation point in a fluid flow.[183] At a stagnation point the fluid velocity is zero. In an incompressible flow, stagnation pressure is equal to the sum of the free-stream static pressure and the free-stream dynamic pressure.[184]
Standard electrode potential
.
neutron-degenerate matter, and quark–gluon plasma, which only occur, respectively, in situations of extreme cold, extreme density, and extremely high energy. For a complete list of all exotic states of matter, see the list of states of matter
.
Statics
The study of forces in a non-moving, rigid body.
experiments.[188]
Steam table
Thermodynamic data table containing steam or water properties .[189]
Stefan–Boltzmann law
The Stefan–Boltzmann law describes the power radiated from a black body in terms of its temperature. Specifically, the Stefan–Boltzmann law states that the total energy radiated per unit surface area of a black body across all wavelengths per unit time (also known as the black-body
radiant emittance) is directly proportional to the fourth power of the black body's thermodynamic temperature
T:
The
Stefan–Boltzmann constant, is derived from other known physical constants. Since 2019
, the value of the constant is
where k is the Boltzmann constant, h is the Planck constant, and c is the speed of light in vacuum. The radiance from a specified angle of view (watts per square metre per steradian) is given by
A body that does not absorb all incident radiation (sometimes known as a grey body) emits less total energy than a black body and is characterized by an emissivity, :
The radiant emittance has
SI units of measure are joules per second per square metre, or equivalently, watts per square metre. The SI unit for absolute temperature T is the kelvin
. is the emissivity of the grey body; if it is a perfect blackbody, . In the still more general (and realistic) case, the emissivity depends on the wavelength, . To find the total power radiated from an object, multiply by its surface area, :
Wavelength- and subwavelength-scale particles,[190] metamaterials,[191] and other nanostructures are not subject to ray-optical limits and may be designed to exceed the Stefan–Boltzmann law.
hydraulic jacks or electric linear actuators, attached in pairs to three positions on the platform's baseplate, crossing over to three mounting points on a top plate. All 12 connections are made via universal joints. Devices placed on the top plate can be moved in the six degrees of freedom
in which it is possible for a freely-suspended body to move: three linear movements x, y, z (lateral, longitudinal, and vertical), and the three rotations (pitch, roll, and yaw).
deformation in response to an applied force.[192]
The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.[193]
reactants and products before, during, and following chemical reactions
. Stoichiometry is founded on the
law of conservation of mass
where the total mass of the reactants equals the total mass of the products, leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of the products can be empirically determined, then the amount of the other reactants can also be calculated.
Strain
.
plastic deformation
. Work hardening may be desirable, undesirable, or inconsequential, depending on the context. This strengthening occurs because of
heat treatment, including low-carbon steel, are often work-hardened. Some materials cannot be work-hardened at low temperatures, such as indium,[196] however others can be strengthened only via work hardening, such as pure copper and aluminum.[197]
ultimate strength, Young's modulus, and Poisson's ratio
. In addition, the mechanical element's macroscopic properties (geometric properties) such as its length, width, thickness, boundary constraints and abrupt changes in geometry such as holes are considered.
reaction. These macroscopic forces are actually the net result of a very large number of intermolecular forces and collisions between the particles in those molecules
. Stress is frequently represented by a lowercase Greek letter sigma (σ).
Stress–strain analysis
Stress–strain analysis (or stress analysis) is an engineering discipline that uses many methods to determine the stresses and strains in materials and structures subjected to forces. In continuum mechanics, stress is a physical quantity that expresses the internal forces that neighboring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material. In simple terms we can define stress as the force of resistance per unit per unit area, offered by a body against deformation. Stress is the ratio of force over area (S =R/A, where S is the stress, R is the internal resisting force and A is the cross-sectional area). Strain is the ratio of change in length to the original length, when a given body is subjected to some external force (Strain= change in length÷the original length).
yield strength and the ultimate tensile strength
.
Structural analysis
Is the determination of the effects of loads on physical structures and their components. Structures subject to this type of
stresses, support reactions, accelerations, and stability. The results of the analysis are used to verify a structure's fitness for use, often precluding physical tests. Structural analysis is thus a key part of the engineering design of structures.[198]
specifications. Accepted technical standards are used for acceptance testing and inspection
.
Sublimation
Is the transition of a substance directly from the solid to the gas state,[202] without passing through the liquid state.[203] Sublimation is an endothermic process that occurs at temperatures and pressures below a substance's triple point in its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid. The reverse process of sublimation is deposition or desublimation, in which a substance passes directly from a gas to a solid phase.[204] Sublimation has also been used as a generic term to describe a solid-to-gas transition (sublimation) followed by a gas-to-solid transition (deposition).[205] While vaporization from liquid to gas occurs as evaporation from the surface if it occurs below the boiling point of the liquid, and as boiling with formation of bubbles in the interior of the liquid if it occurs at the boiling point, there is no such distinction for the solid-to-gas transition which always occurs as sublimation from the surface.
autonomous robotics and elsewhere in real-time AI
.
Surface tension
Is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water to float on a water surface without becoming even partly submerged.
Superconductivity
Is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.[209][210][211][212]
GPa) when measured by the Vickers hardness test.[213][214][215][216] They are virtually incompressible solids with high electron density and high bond covalency. As a result of their unique properties, these materials are of great interest in many industrial areas including, but not limited to, abrasives, polishing and cutting tools, disc brakes, and wear
-resistant and protective coatings.
metastable
state; it may be brought to equilibrium by forcing the excess of solute to separate from the solution. The term can also be applied to a mixture of gases.

T

Tangential acceleration
The velocity of a particle moving on a curved path as a function of time can be written as:
with v(t) equal to the speed of travel along the path, and
a
unit vector tangent to the path pointing in the direction of motion at the chosen moment in time. Taking into account both the changing speed v(t) and the changing direction of ut, the acceleration of a particle moving on a curved path can be written using the chain rule of differentiation[217]
for the product of two functions of time as:
where un is the unit (inward)
normal vector to the particle's trajectory (also called the principal normal), and r is its instantaneous radius of curvature based upon the osculating circle at time t. These components are called the tangential acceleration and the normal or radial acceleration (or centripetal acceleration in circular motion, see also circular motion and centripetal force
). Geometrical analysis of three-dimensional space curves, which explains tangent, (principal) normal and binormal, is described by the Frenet–Serret formulas.[218][219]
norm or requirement for a repeatable technical task. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes, and practices. In contrast, a custom, convention, company product, corporate standard, and so forth that becomes generally accepted and dominant is often called a de facto standard
.
temperature scales that historically have used various reference points and thermometric substances for definition. The most common scales are the Celsius scale (formerly called centigrade, denoted °C), the Fahrenheit scale (denoted °F), and the Kelvin scale (denoted K), the last of which is predominantly used for scientific purposes by conventions of the International System of Units
(SI).
Tempering (metallurgy)
Heat treatment to alter the crystal structure of a metal such as steel.
Tensile force
Pulling force, tending to lengthen an object.
Tensile modulus
Young's modulus , the Young modulus, or the
modulus of elasticity in tension, is a mechanical property that measures the tensile stiffness of a solid material. It quantifies the relationship between tensile stress
(force per unit area) and axial strain (proportional deformation) in the linear elastic region of a material and is determined using the formula:[220]
Young's moduli are typically so large that they are expressed not in pascals but in gigapascals (GPa).
Tensile strength
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or within equations,
ductile
materials the ultimate tensile strength can be higher.
strain-hardening characteristics.[226] Uniaxial tensile testing is the most commonly used for obtaining the mechanical characteristics of isotropic
materials. Some materials use biaxial tensile testing. The main difference between these testing machines being how load is applied on the materials.
tensile forces. Examples of tension members are bracing for buildings and bridges, truss members, and cables in suspended roof
systems.
Thermal conduction
Is the transfer of internal energy by microscopic collisions of particles and movement of electrons within a body. The colliding particles, which include molecules, atoms and electrons, transfer disorganized microscopic kinetic and potential energy, jointly known as internal energy. Conduction takes place in all phases: solid, liquid, and gas.
Thermal equilibrium
Two physical systems are in thermal equilibrium if there is no net flow of thermal energy between them when they are connected by a path permeable to heat. Thermal equilibrium obeys the zeroth law of thermodynamics. A system is said to be in thermal equilibrium with itself if the temperature within the system is spatially uniform and temporally constant. Systems in thermodynamic equilibrium are always in thermal equilibrium, but the converse is not always true. If the connection between the systems allows transfer of energy as 'change in internal energy' but does not allow transfer of matter or transfer of energy as work, the two systems may reach thermal equilibrium without reaching thermodynamic equilibrium.
thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. Particle motion results in charge-acceleration or dipole
oscillation which produces electromagnetic radiation.
microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology
.
cosmological and astrophysical realm, including astronomy.[229]
series
connection with a resistance Rth."
  • The equivalent voltage Vth is the voltage obtained at terminals A–B of the network with terminals A–B open circuited.
  • The equivalent resistance Rth is the resistance that the circuit between terminals A and B would have if all ideal voltage sources in the circuit were replaced by a short circuit and all ideal current sources were replaced by an open circuit.
  • If terminals A and B are connected to one another, the current flowing from A to B will be Vth/Rth. This means that Rth could alternatively be calculated as Vth divided by the short-circuit current between A and B when they are connected together.
In
one-port network to be reduced to a single voltage source
and a single impedance. The theorem also applies to frequency domain AC circuits consisting of
resistive impedances
. It means the theorem applies for AC in an exactly same way to DC except that resistances are generalized to impedances.
Three-phase electric power
Is a common method of alternating current electric power generation, transmission, and distribution.[230] It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power. It is also used to power large motors and other heavy loads.
Torque
In physics and mechanics, torque is the rotational equivalent of linear force.[231] It is also referred to as the moment, moment of force, rotational force or turning effect, depending on the field of study. The concept originated with the studies by Archimedes of the usage of levers. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object around a specific axis. Another definition of torque is the product of the magnitude of the force and the perpendicular distance of the line of action of a force from the axis of rotation. The symbol for torque is typically or τ, the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by M.
Torsional vibration
Is angular vibration of an object—commonly a shaft along its axis of rotation. Torsional vibration is often a concern in power transmission systems using rotating shafts or couplings where it can cause failures if not controlled. A second effect of torsional vibrations applies to passenger cars. Torsional vibrations can lead to seat vibrations or noise at certain speeds. Both reduce the comfort.
stressed
. Toughness requires a balance of strength and ductility.[232]
motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates
; hence, a complete trajectory is defined by position and momentum, simultaneously. The mass might be a
central mass
. In
states of a dynamical system (see e.g. Poincaré map). In discrete mathematics
, a trajectory is a sequence of values calculated by the iterated application of a mapping to an element of its source.
Transducer
Is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.[235] Transducers are often employed at the boundaries of
form of energy to another is known as transduction.[236]
passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any one coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction
, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil.
right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis
. The trigonometric functions most widely used in modern mathematics are the
sine, the cosine, and the tangent. Their reciprocals are respectively the cosecant, the secant, and the cotangent, which are less used. Each of these six trigonometric functions has a corresponding inverse function, and an analog among the hyperbolic functions
.
sine.[240]
Trimean
The trimean is a measure of a probability distribution's location defined as a weighted average of the distribution's median and its two quartiles
polymorphs. Helium-4 is a special case that presents a triple point involving two different fluid phases (lambda point).[241]
Trouton's rule
Trouton's rule states that the entropy of vaporization is almost the same value, about 85–88 J/(K·mol), for various kinds of liquids at their boiling points.[242] The entropy of vaporization is defined as the ratio between the enthalpy of vaporization and the boiling temperature. It is named after Frederick Thomas Trouton. It can be expressed as a function of the gas constant R:
A similar way of stating this (Trouton's ratio) is that the latent heat is connected to boiling point roughly as
Truncated mean
A truncated mean or trimmed mean is a statistical measure of central tendency, much like the mean and median. It involves the calculation of the mean after discarding given parts of a probability distribution or sample at the high and low end, and typically discarding an equal amount of both. This number of points to be discarded is usually given as a percentage of the total number of points, but may also be given as a fixed number of points.
Truss
A truss is an assembly of members such as beams, connected by nodes, that creates a rigid structure.[243] In engineering, a truss is a
structure that "consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object".[244] A "two-force member" is a structural component where force is applied to only two points. Although this rigorous definition allows the members to have any shape connected in any stable configuration, trusses typically comprise five or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes
.
waterwheels. Gas, steam, and water
turbines have a casing around the blades that contains and controls the working fluid.
compressors. While a turbine transfers energy from a fluid to a rotor, a compressor transfers energy from a rotor to a fluid.[246][247]
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers.[248]

U

Ultimate tensile strength
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or Ftu within equations,[221][222][223] is the capacity of a material or structure to withstand loads tending to elongate, as opposed to compressive strength, which withstands loads tending to reduce size. In other words, tensile strength resists tension (being pulled apart), whereas compressive strength resists compression (being pushed together). Ultimate tensile strength is measured by the maximum stress that a material can withstand while being stretched or pulled before breaking. In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently.
position x and momentum
p, can be known.
Unicode
A standard for the consistent encoding of textual characters.
spatial vector) of length 1. A unit vector is often denoted by a lowercase letter with a circumflex
, or "hat": (pronounced "i-hat"). The term
direction vector
is used to describe a unit vector being used to represent spatial direction, and such quantities are commonly denoted as d. .
Unsaturated compound
.
Upthrust
Buoyancy, or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid.
end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country
.

V

vesicles and are effectively just larger forms of these.[252]
The organelle has no basic shape or size; its structure varies according to the requirements of the cell.
Vacuum
An absence of mass in a volume.
Valence
In chemistry, the valence or valency of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules. The concept of valence developed in the second half of the 19th century and helped successfully explain the molecular structure of inorganic and organic compounds.[253] The quest for the underlying causes of valence led to the modern theories of chemical bonding, including the cubical atom (1902), Lewis structures (1916), valence bond theory (1927), molecular orbitals (1928), valence shell electron pair repulsion theory (1958), and all of the advanced methods of quantum chemistry.
electronic states. On a graph of the electronic band structure
of a material, the valence band is located below the Fermi level, while the conduction band is located above it. The distinction between the valence and conduction bands is meaningless in metals, because conduction occurs in one or more partially filled bands that take on the properties of both the valence and conduction bands.
Valence bond theory
In chemistry, valence bond (VB) theory is one of the two basic theories, along with molecular orbital (MO) theory, that were developed to use the methods of quantum mechanics to explain chemical bonding. It focuses on how the atomic orbitals of the dissociated atoms combine to give individual chemical bonds when a molecule is formed. In contrast, molecular orbital theory has orbitals that cover the whole molecule.[254]
shared pair
.
Valence shell
The valence shell is the set of orbitals which are energetically accessible for accepting electrons to form chemical bonds. For main group elements, the valence shell consists of the ns and np orbitals in the outermost electron shell. In the case of transition metals (the (n-1)d orbitals), and lanthanides and actinides (the (n-2)f and (n-1)d orbitals), the orbitals involved can also be in an inner electron shell. Thus, the shell terminology is a misnomer as there is no correspondence between the valence shell and any particular electron shell in a given element. A scientifically correct term would be valence orbital to refer to the energetically accessible orbitals of an element.
fittings
, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll.
ideally. The ideal gas law treats gas molecules as point particles that interact with their containers but not each other, meaning they neither take up space nor change kinetic energy during collisions (i.e. all collisions are perfectly elastic).[255] The ideal gas law states that volume (V) occupied by n moles of any gas has a pressure (P) at temperature (T) in kelvins given by the following relationship, where R is the gas constant
:
To account for
the volume
that a real gas molecule takes up, the Van der Waals equation replaces V in the ideal gas law with , where Vm is the molar volume of the gas and b is the volume that is occupied by one mole of the molecules. This leads to:[255]
The second modification made to the ideal gas law accounts for the fact that gas molecules do in fact interact with each other (they usually experience attraction at low pressures and repulsion at high pressures) and that real gases therefore show different compressibility than ideal gases. Van der Waals provided for
intermolecular interaction
by adding to the observed pressure P in the equation of state a term , where a is a constant whose value depends on the gas. The Van der Waals equation is therefore written as:[255]
and, for n moles of gas, can also be written as the equation below:
where Vm is the molar volume of the gas, R is the universal gas constant, T is temperature, P is pressure, and V is volume. When the molar volume Vm is large, b becomes negligible in comparison with Vm, a/Vm2 becomes negligible with respect to P, and the Van der Waals equation reduces to the ideal gas law, PVm=RT.[255] It is available via its traditional derivation (a mechanical equation of state), or via a derivation based in
principle of corresponding states
.
covalent bonds
, these attractions do not result from a chemical electronic bond; they are comparatively weak and therefore more susceptible to disturbance. The Van der Waals force quickly vanishes at longer distances between interacting molecules.
van 't Hoff equation
Relates the change in the equilibrium constant, Keq, of a chemical reaction to the change in temperature, T, given the standard enthalpy change, ΔrH⊖, for the process. It was proposed by Dutch chemist Jacobus Henricus van 't Hoff in 1884 in his book Études de dynamique chimique (Studies in Dynamic Chemistry).[256] The Van 't Hoff equation has been widely utilized to explore the changes in
state functions in a thermodynamic system. The Van 't Hoff plot, which is derived from this equation, is especially effective in estimating the change in enthalpy and entropy of a chemical reaction
.
ion pairing
occurs in solution. At a given instant a small percentage of the ions are paired and count as a single particle. Ion pairing occurs to some extent in all electrolyte solutions. This causes the measured Van 't Hoff factor to be less than that predicted in an ideal solution. The deviation for the Van 't Hoff factor tends to be greatest where the ions have multiple charges.
reactance, e.g. for impedance matching in antenna tuners
.
Variable resistor
.
added together and multiplied ("scaled") by numbers, called scalars. Scalars are often taken to be real numbers, but there are also vector spaces with scalar multiplication by complex numbers, rational numbers, or generally any field. The operations of vector addition and scalar multiplication must satisfy certain requirements, called vector axioms
. To specify that the scalars are real or complex numbers, the terms real vector space and complex vector space are often used.
fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista Venturi
.
random
, such as the movement of a tire on a gravel road. Vibration can be desirable: for example, the motion of a
reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker
. In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motors, or any mechanical device in operation are typically unwanted. Such vibrations could be caused by imbalances in the rotating parts, uneven friction, or the meshing of gear teeth. Careful designs usually minimize unwanted vibrations.
Virtual leak
Traces of gas trapped in cavities within a vacuum chamber, slowly dissipating out in the main chamber, thus appearing like a leak from the outside.
stress
is applied. Elastic materials strain when stretched and immediately return to their original state once the stress is removed. Viscoelastic materials have elements of both of these properties and, as such, exhibit time-dependent strain. Whereas elasticity is usually the result of
amorphous material.[257]
tensile stress.[258] For liquids, it corresponds to the informal concept of "thickness": for example, honey has a higher viscosity than water.[259]
SI units
, 1 VA = 1 N m A−1 s −1 A = 1 N m s −1 = 1 J s −1 = 1 W). VA rating is most useful in rating wires and switches (and other power handling equipment) for inductive loads.
electrical engineer Constantin Budeanu and introduced in 1930 by the IEC in Stockholm, which has adopted it as the unit for reactive
power. Special instruments called varmeters are available to measure the reactive power in a circuit.[262] The unit "var" is allowed by the
directive 80/181/EEC (the "metric directive"), the correct symbol is lower-case "var",[264]
although the spellings "Var" and "VAr" are commonly seen, and "VAR" is widely used throughout the power industry.
electrostatic potential difference between two metals (or one metal and one electrolyte) that are in contact and are in thermodynamic equilibrium. Specifically, it is the potential difference between a point close to the surface of the first metal, and a point close to the surface of the second metal (or electrolyte).[265]
International System of Units, the derived unit for voltage is named volt.[266] In SI units, work per unit charge is expressed as joules per coulomb, where 1 volt = 1 joule (of work) per 1 coulomb (of charge). The official SI definition for volt uses power and current, where 1 volt = 1 watt (of power) per 1 ampere (of current).[266]
SI unit is m3/s (cubic metres per second
).
von Mises yield criterion
The von Mises yield criterion (also known as the maximum distortion energy criterion[267]) suggests that yielding of a ductile material begins when the second deviatoric stress invariant reaches a critical value.
ductile
materials, such as some metals. Prior to yield, material response can be assumed to be of a nonlinear elastic, viscoelastic, or linear elastic behavior. In materials science and engineering the von Mises yield criterion can also be formulated in terms of the von Mises stress or equivalent tensile stress, . This is a scalar value of stress that can be computed from the
yield strength
, . The von Mises stress is used to predict yielding of materials under complex loading from the results of uniaxial tensile tests. The von Mises stress satisfies the property where two stress states with equal distortion energy have an equal von Mises stress.

W

Watt
The SI unit of power, rate of doing work.
Wave
Is a disturbance that transfers energy through matter or space, with little or no associated mass transport. Waves consist of oscillations or vibrations of a physical medium or a field, around relatively fixed locations. From the perspective of mathematics, waves, as functions of time and space, are a class of signals.[269]
Wavelength
Is the spatial period of a periodic wave—the distance over which the wave's shape repeats.[270][271] It is thus the inverse of the spatial frequency. Wavelength is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns.[272][273] Wavelength is commonly designated by the
Greek letter lambda
(λ). The term wavelength is also sometimes applied to
interference of several sinusoids.[274]
' .
normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width.[275][276]
Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle.
Weighted arithmetic mean
The weighted arithmetic mean is similar to an ordinary arithmetic mean (the most common type of average), except that instead of each of the data points contributing equally to the final average, some data points contribute more than others. The notion of weighted mean plays a role in descriptive statistics and also occurs in a more general form in several other areas of mathematics. If all the weights are equal, then the weighted mean is the same as the arithmetic mean. While weighted means generally behave in a similar fashion to arithmetic means, they do have a few counterintuitive properties, as captured for instance in Simpson's paradox.
Wet-bulb temperature
The temperature of a wetted thermometer with an air current across it. Used in psychrometry.
Wheel and axle
Are one of six simple machines identified by Renaissance scientists drawing from Greek texts on technology.[277] The wheel and axle consists of a wheel attached to a smaller axle so that these two parts rotate together in which a force is transferred from one to the other. A hinge or bearing supports the axle, allowing rotation. It can amplify force; a small force applied to the periphery of the large wheel can move a larger load attached to the axle.
weighted average
of the truncated mean and the quantiles at which it is limited, which corresponds to replacing parts with the corresponding quantiles.
plastic deformation. This strengthening occurs because of dislocation movements and dislocation generation within the crystal structure of the material.[194]

X-Z

independent variable.[279]
independent variables.[280]
Yield
The point of maximum elastic deformation of a material; above yield the material is permanently deformed.
Young's modulus
A measure of the stiffness of a material; the amount of force per unit area require to produce a unit strain.
Z-axis
In algebraic geometry, the axis on a graph of at least three dimensions that is usually drawn vertically and usually shows the range of values of a variable dependent on two other variables or the third independent variable.[281]
Zero defects
A quality assurance philosophy that aims to reduce the need for inspection of components by improving their quality.
compression. In a truss a zero force member is often found at pins (any connections within the truss) where no external load is applied and three or fewer truss members meet. Recognizing basic zero force members can be accomplished by analyzing the forces acting on an individual pin in a physical system
. NOTE: If the pin has an external force or moment applied to it, then all of the members attached to that pin are not zero force members UNLESS the external force acts in a manner that fulfills one of the rules below:
  • If two non-collinear members meet in an unloaded joint, both are zero-force members.
  • If three members meet in an unloaded joint of which two are collinear, then the third member is a zero-force member.
Reasons for Zero-force members in a truss system
  • These members contribute to the stability of the structure, by providing buckling prevention for long slender members under compressive forces
  • These members can carry loads in the event that variations are introduced in the normal external loading configuration.
Zeroth law of thermodynamics
The equivalence principle applied to temperature; two systems in thermal equilibrium with a third are also in thermal equilibrium with each other.

See also

Notes

  1. ^ Electric and magnetic fields, according to the theory of relativity, are the components of a single electromagnetic field.
  2. ^ Pronounced "x bar".
  3. ^ Greek letter μ, for "mean", pronounced /'mjuː/.
  4. ^ Strictly speaking, a probability of 0 indicates that an event almost never takes place, whereas a probability of 1 indicates than an event almost certainly takes place. This is an important distinction when the sample space is infinite. For example, for the continuous uniform distribution on the real interval [5, 10], there are an infinite number of possible outcomes, and the probability of any given outcome being observed — for instance, exactly 7 — is 0. This means that when we make an observation, it will almost surely not be exactly 7. However, it does not mean that exactly 7 is impossible. Ultimately some specific outcome (with probability 0) will be observed, and one possibility for that specific outcome is exactly 7.
  1. relativistic mass, depending on its energy, but this varies according to the frame of reference
    .
  2. atomic hypothesis as the single most prolific scientific concept.[114]
  3. philosophical world
    .
  4. ^ The preferred spelling varies by country and even by industry. Further, both spellings are often used within a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.

References

  1. ^ Robert L. Norton, Machine Design, (4th Edition), Prentice-Hall, 2010
  2. ISBN 978-0-7918-0229-8
    .
  3. ISBN 978-0-07-061141-2
    .
  4. OCLC 36417892
    .
  5. doi:10.1007/978-94-009-0279-4_9
    .
  6. ^ Hu, J.; Niu, H.; Carrasco, J.; Lennox, B.; Arvin, F., "Voronoi-Based Multi-Robot Autonomous Exploration in Unknown Environments via Deep Reinforcement Learning" IEEE Transactions on Vehicular Technology, 2020.
  7. ISBN 9780465040858
    .
  8. ISBN 9780321501219
    .
  9. ^ Purcell, Edward. p278. Electricity and Magnetism, 3rd edition, Cambridge University Press, 2013. 839pp.
  10. ISBN 978-92-822-2272-0
    , p. 22
  11. ISBN 978-92-822-2272-0
    , p. 21
  12. ISBN 978-94-011-7040-6
    .
  13. ^ Himmelblau, David M. (1967). Basic Principles and Calculations in Chemical Engineering (2nd ed.). Prentice Hall.
  14. 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 April 9, 2013.
  15. ^ "Density definition in Oil Gas Glossary". Oilgasglossary.com. Archived from the original on August 5, 2010. Retrieved September 14, 2010.
  16. Jensen, William B. (2005). The Origins of the Symbols A and Z for Atomic Weight and Number. J. Chem. Educ. 82: 1764. link Archived 2020-12-02 at the Wayback Machine
    .
  17. ^ "How many protons, electrons and neutrons are in an atom of krypton, carbon, oxygen, neon, silver, gold, etc...?". Thomas Jefferson National Accelerator Facility. Retrieved 2008-08-27.
  18. ^ "Elemental Notation and Isotopes". Science Help Online. Archived from the original on 2008-09-13. Retrieved 2008-08-27.
  19. ^ Eddy, Matthew Daniel (2008). The Language of Mineralogy: John Walker, Chemistry and the Edinburgh Medical School 1750–1800. Ashgate. Archived from the original on 2015-09-03.
  20. ISBN 978-0262191913
    .
  21. ^ "The Nature of Mathematical Programming Archived 2014-03-05 at the Wayback Machine," Mathematical Programming Glossary, INFORMS Computing Society.
  22. ^ Du, D. Z.; Pardalos, P. M.; Wu, W. (2008). "History of Optimization". In Floudas, C.; Pardalos, P. (eds.). Encyclopedia of Optimization. Boston: Springer. pp. 1538–1542.
  23. ^ Definition from the Journal of Mathematical Physics. "Archived copy". Archived from the original on 2006-10-03. Retrieved 2006-10-03.{{cite web}}: CS1 maint: archived copy as title (link)
  24. ^ a b "mathematics, n.". Oxford English Dictionary. Oxford University Press. 2012. Archived from the original on November 16, 2019. Retrieved June 16, 2012. The science of space, number, quantity, and arrangement, whose methods involve logical reasoning and usually the use of symbolic notation, and which includes geometry, arithmetic, algebra, and analysis.
  25. ISBN 978-0-486-41712-7
    . Mathematics ... is simply the study of abstract structures, or formal patterns of connectedness.
  26. ISBN 978-1-4390-4957-0
    . Calculus is the study of change—how things change, and how quickly they change.
  27. ISBN 978-0-07-066753-2
    . The mathematical study of change, motion, growth or decay is calculus.
  28. ISBN 978-3-642-19532-7
    .
  29. S2CID 122351146
    .
  30. ISBN 978-3-0348-0229-1
    . [I]t is first necessary to ask what is meant by mathematics in general. Illustrious scholars have debated this matter until they were blue in the face, and yet no consensus has been reached about whether mathematics is a natural science, a branch of the humanities, or an art form.
  31. ^ Steen, L.A. (April 29, 1988). The Science of Patterns Science, 240: 611–16. And summarized at Association for Supervision and Curriculum Development Archived October 28, 2010, at the Wayback Machine, www.ascd.org.
  32. ^ Devlin, Keith, Mathematics: The Science of Patterns: The Search for Order in Life, Mind and the Universe (Scientific American Paperback Library) 1996, ISBN 978-0-7167-5047-5
  33. ^ However, in the case of adjacency matrices, matrix multiplication or a variant of it allows the simultaneous computation of the number of paths between any two vertices, and of the shortest length of a path between two vertices.
  34. ^ a b
    ISBN 978-0-19-824449-3
    .
  35. ^ "Matter (physics)". McGraw-Hill's Access Science: Encyclopedia of Science and Technology Online. Archived from the original on 17 June 2011. Retrieved 2009-05-24.
  36. ^ "RHIC Scientists Serve Up "Perfect" Liquid" (Press release). Brookhaven National Laboratory. 18 April 2005. Retrieved 2009-09-15.
  37. ISBN 0-7021-3838-X p. 181
  38. ISBN 0471257087
    .
  39. ^ Elementary Statistics by Robert R. Johnson and Patricia J. Kuby, p. 279
  40. ^ Weisstein, Eric W. "Population Mean". mathworld.wolfram.com. Retrieved 2020-08-21.
  41. ^ Schaum's Outline of Theory and Problems of Probability by Seymour Lipschutz and Marc Lipson, p. 141
  42. ISBN 0-8039-4007-6
    p.2
  43. ^
    ISBN 978-0-19-954145-4
    (entry for "central tendency")
  44. ISBN 0-19-920613-9
    (entry for "central tendency")
  45. ISBN 978-0-19-537123-9
    .
  46. ^ "What is Mechanical Engineering?". 28 December 2018.
  47. ^ Giancoli, D. C. (2009) Physics for scientists & engineers with modern physics (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall.
  48. OCLC 1104689918.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link
    )
  49. ^ Dugas, Rene. A History of Classical Mechanics. New York, NY: Dover Publications Inc, 1988, pg 19.
  50. ^ Rana, N.C., and Joag, P.S. Classical Mechanics. West Petal Nagar, New Delhi. Tata McGraw-Hill, 1991, pg 6.
  51. ^ a b Renn, J., Damerow, P., and McLaughlin, P. Aristotle, Archimedes, Euclid, and the Origin of Mechanics: The Perspective of Historical Epistemology. Berlin: Max Planck Institute for the History of Science, 2010, pg 1-2.
  52. PMID 15406812
    .
  53. ^ D. Griffiths (2008)
  54. ^ Metallic bonding. chemguide.co.uk
  55. ^ Metal structures. chemguide.co.uk
  56. ^ Chemical Bonds. chemguide.co.uk
  57. ^ "Physics 133 Lecture Notes" Spring, 2004. Marion Campus. physics.ohio-state.edu
  58. ^ John, Blyler (27 December 2019). "What is middle-out systems engineering?". DesignNews. Retrieved 28 September 2020.
  59. ^ Dodge 2003.
  60. ISBN 0-201-07616-0
  61. OCLC 934604
    .
  62. ^ Hu, J.; Bhowmick, P.; Lanzon, A., "Group Coordinated Control of Networked Mobile Robots with Applications to Object Transportation" IEEE Transactions on Vehicular Technology, 2021.
  63. ^ "Information Engineering Main/Home Page". www.robots.ox.ac.uk. Retrieved 2018-10-03.
  64. ^ Hu, J.; Bhowmick, P.; Jang, I.; Arvin, F.; Lanzon, A., "A Decentralized Cluster Formation Containment Framework for Multirobot Systems" IEEE Transactions on Robotics, 2021.
  65. ^ Hu, J.; Turgut, A.; Lennox, B.; Arvin, F., "Robust Formation Coordination of Robot Swarms with Nonlinear Dynamics and Unknown Disturbances: Design and Experiments" IEEE Transactions on Circuits and Systems II: Express Briefs, 2021.
  66. ^ Damodar N. Gujarati. Essentials of Econometrics. McGraw-Hill Irwin. 3rd edition, 2006: p. 110.
  67. ISBN 978-0-534-55396-8
    .
  68. ISBN 978-0-07-015389-9
    .
  69. doi:10.1351/goldbook.E02293
  70. doi:10.1351/goldbook.A00044
  71. ^ "Typography of unit symbols for Molar and Liter in siunitx". TeX - LaTeX Stack Exchange.
  72. ISBN 0-632-03583-8. p. 41. Electronic version.
  73. ^ "Molding – Definition of molding by Merriam-Webster". merriam-webster.com. 26 June 2023.
  74. doi:10.1351/goldbook.M04002
  75. ISBN 978-0-395-43302-7
    .
  76. ISBN 978-0-13-066997-1
    .
  77. ISBN 978-0-07-115221-1
    .
  78. ISBN 978-0-669-41794-4
    .
  79. ISBN 978-81-224-1512-4
    .
  80. ^ "Molecule". Encyclopædia Britannica. 22 January 2016. Retrieved 23 February 2016.
  81. ^ "Molecular Physics". Archived from the original on 2019-11-16. Retrieved 2021-09-13.
  82. ISBN 978-0-199-69599-7
    .
  83. ^
    ISBN 978-1-780-74647-0
    .
  84. ^ Mertens, Susanne (2016). "Direct neutrino mass experiments". Journal of Physics: Conference Series. 718 (2): 022013. arXiv:1605.01579. Bibcode:2016JPhCS.718b2013M. doi:10.1088/1742-6596/718/2/022013. S2CID 56355240.
  85. ^ Overbye, Dennis (15 April 2020). "Why The Big Bang Produced Something Rather Than Nothing - How did matter gain the edge over antimatter in the early universe? Maybe, just maybe, neutrinos". The New York Times. Retrieved 16 April 2020.
  86. ISBN 978-0-199-69599-7
    .
  87. ISBN 978-1-118-01343-4
    .
  88. ISBN 978-0-521-66396-0
    .
  89. ^ Kundu, P.; Cohen, I. Fluid Mechanics. p. (page needed).
  90. ISBN 978-0-521-11903-0. Archived from the original
    on 2019-04-28. Retrieved 2021-10-02.
  91. ISBN 9788131703571
    .
  92. ISBN 0-13-035471-6
    .
  93. ^ britannica.com
  94. ISBN 978-1-114-44384-6
    .
  95. ^ Gardner, Julian W.; Varadan, Vijay K.; Awadelkarim, Osama O. (2001). Microsensors, MEMS, and Smart Devices John 2. Wiley. pp. 23–322.
    ISBN 978-0-471-86109-6
    .
  96. ^ Arthur Schuster (1904). An Introduction to the Theory of Optics. London: Edward Arnold. An Introduction to the Theory of Optics By Arthur Schuster.
  97. ^ "The Higgs Boson". CERN. 26 May 2023.
  98. ^ "The BEH-Mechanism, Interactions with Short Range Forces and Scalar Particles" (PDF). 8 October 2013.
  99. ^ "Pascal's principle - Definition, Example, & Facts". britannica.com. Archived from the original on 2 June 2015. Retrieved 9 May 2018.
  100. ^ "Pascal's Principle and Hydraulics". www.grc.nasa.gov. Archived from the original on 5 April 2018. Retrieved 9 May 2018.
  101. ^ "Pressure". hyperphysics.phy-astr.gsu.edu. Archived from the original on 28 October 2017. Retrieved 9 May 2018.
  102. ISBN 978-0-471-46886-8
    .
  103. OCLC 16986801. Archived from the original on 2011-04-02. Retrieved 2011-06-14.{{cite journal}}: CS1 maint: unfit URL (link
    ).
  104. O'Connor, J.J.; Robertson, E.F. (August 2006). "Étienne Pascal". University of St. Andrews, Scotland. Archived
    from the original on 19 April 2010. Retrieved 5 February 2010.
  105. ISBN 978-0-87779-017-4
    .
  106. ^ "Petroleum Engineers: Occupational Outlook Handbook: U.S. Bureau of Labor Statistics". www.bls.gov. Retrieved 2018-02-06.
  107. ISBN 978-0-13-914861-3
    .
  108. ISBN 978-0-486-13485-7
    .
  109. ISBN 978-0-521-27456-2
    .
  110. ISBN 978-0-240-80758-4
    .
  111. ISBN 978-1-259-69652-7
    .
  112. ISBN 9780198769866
    .
  113. ^ Gibbs, J. W. (1961), Scientific Papers, Dover, New York{{citation}}: CS1 maint: location missing publisher (link)
  114. ^ Feynman, Leighton & Sands 1963, p. I-2 "If, in some cataclysm, all [] scientific knowledge were to be destroyed [save] one sentence [...] what statement would contain the most information in the fewest words? I believe it is [...] that all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another ..."
  115. ^ Maxwell 1878, p. 9 "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events."
  116. ^ Young & Freedman 2014, p. 1 "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of the human intellect in its quest to understand our world and ourselves."
  117. ^ Young & Freedman 2014, p. 2 "Physics is an experimental science. Physicists observe the phenomena of nature and try to find patterns that relate these phenomena."
  118. ^ Holzner 2006, p. 7 "Physics is the study of your world and the world and universe around you."
  119. ISBN 978-92-822-2272-0
  120. ^ "2022 CODATA Value: Planck constant". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18.
  121. ^ "Resolutions of the 26th CGPM" (PDF). BIPM. 2018-11-16. Archived from the original (PDF) on 2018-11-19. Retrieved 2018-11-20.
  122. ISBN 978-0-7503-0183-1
    .
  123. ISBN 978-1-4398-8132-3
    .
  124. ISBN 978-0-486-46290-5
    .
  125. ISBN 978-1-107-02541-7
    .
  126. ^ Smith, Clare (2001). Environmental Physics. London:
    ISBN 0-415-20191-8
    .
  127. OCLC 1142734534. Archived
    from the original on 23 April 2020. Power or Activity is the time rate of doing work, or if W represents work and P power, P = dw/dt. (p. xxviii) ... ACTIVITY. Power or rate of doing work; unit, the watt. (p. 435)
  128. ^ Heron, C. A. (1906). "Electrical Calculations for Rallway Motors". Purdue Eng. Rev. (2): 77–93. Archived from the original on 23 April 2020. Retrieved 23 April 2020. The activity of a motor is the work done per second, ... Where the joule is employed as the unit of work, the international unit of activity is the joule-per-second, or, as it is commonly called, the watt. (p. 78)
  129. doi:10.1038/066118b0
    . If the watt is assumed as unit of activity...
  130. ISBN 978-0-321-51671-8
    . Retrieved 6 April 2020. Pressure itself is not a Force, even though we sometimes talk "informally" about the "force exerted by the pressure. The correct statement is that the Fluid exerts a force on a surface. In addition, Pressure is a scalar, not a vector.
  131. ISBN 978-0-534-24312-8
    .
  132. ISBN 0-471-25708-7
    .
  133. OCLC 161828328
    .
  134. OCLC 190785258
    .
  135. ^ Ross, Sheldon M. (2010). A first course in probability. Pearson.
  136. ^ Inferring From Data
  137. ^ "Why is quantum mechanics based on probability theory?". Stack Exchange. July 1, 2014.
  138. ^ Pump classifications. Fao.org. Retrieved on 2011-05-25.
  139. ISBN 978-0-201-50397-5
    .
  140. ISBN 978-0201500646
    . Retrieved 2020-12-19.
  141. ^ Dana, Edward Salisbury (1922). A text-book of mineralogy: with an extended treatise on crystallography... New York, London(Chapman Hall): John Wiley and Sons. pp. 195–200, 316.
  142. ISBN 0-471-34856-2
    .
  143. ISBN 1-55937-079-3
  144. ISBN 978-05-2185-902-8
    . Retrieved March 24, 2019.
  145. ISBN 978-81-7008-592-8
    . Retrieved March 24, 2019.
  146. ISBN 978-0-13-066946-9
    . Retrieved March 24, 2019.
  147. ISBN 0-08-021778-8
  148. ^ Andy Ruina and Rudra Pratap (2015). Introduction to Statics and Dynamics. Oxford University Press. (link: [1])
  149. ^ "German National Library". International classification system of the German National Library (GND).
  150. ^
    ISBN 9780199233991
    .
  151. ISBN 9781349004874. Retrieved 5 July 2020.[permanent dead link
    ]
  152. ISBN 9781351661386
    . Retrieved 5 July 2020.
  153. ISBN 9780199587438
    .
  154. ^ "Rotational Quantities".
  155. ^ "Safe Failure Fraction". ScienceDirect. Retrieved 21 September 2020.
  156. ^ "Transport - Transport - UNECE". Unece.org. Retrieved 22 December 2017.
  157. Mosby's Medical, Nursing & Allied Health Dictionary
    , Fourth Edition, Mosby-Year Book Inc., 1994, p. 1394
  158. ISBN 0-321-28713-4
    .
  159. ISBN 0-03-010567-6
    .
  160. ISBN 0-387-98258-2
    .
  161. ISBN 0-471-43334-9
    .
  162. ISBN 0-387-95385-X
    .
  163. ^ a b Young, James F. (2000). "Basic Mechanics". ELEC 201:Introduction to Engineering Design. Electrical and Computer Engineering Dept., Rice Univ. Retrieved 2011-03-29.
  164. ISBN 0-395-20360-0.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  165. ^ "Screw". How Stuff Works website. Discovery Communications. 2011. Retrieved 2011-03-29.
  166. ISBN 978-0-470-41303-6
    .
  167. ISBN 978-0-07-061141-2
    .
  168. ^ "Signs of dark matter may point to mirror matter candidate".
  169. ^ Higdon, Ohlsen, Stiles and Weese (1960), Mechanics of Materials, article 4-9 (2nd edition), John Wiley & Sons, Inc., New York. Library of Congress CCN 66-25222
  170. ^ However, the definition of thermal infrared may start at wavelengths as short as 1.1μm (longer than which optical instruments have difficulty measuring) or anywhere between 2.0μm and 4.0μm, depending on the method of measurement and its purpose.
  171. ^ L. Chen, G. Yan, T. Wang, H. Ren, J. Calbó, J. Zhao, R. McKenzie (2012), Estimation of surface shortwave radiation components under all sky conditions: Modeling and sensitivity analysis, Remote Sensing of Environment, 123: 457–469.
  172. PMID 27286184
    .
  173. ISBN 0-13-216771-9
    .
  174. ISBN 978-81-203-2611-8
    .
  175. ISBN 978-0-88029-251-1
    .
  176. ^ Anderson, William Ballantyne (1914). Physics for Technical Students: Mechanics and Heat. New York: McGraw Hill. p. 112. Retrieved 2008-05-11.
  177. ^ "Mechanics". Encyclopædia Britannica. Vol. 3. John Donaldson. 1773. p. 44. Retrieved 5 April 2020.
  178. ISBN 9780122004001
    .
  179. ^ Albert Einstein (1905) "Zur Elektrodynamik bewegter Körper", Annalen der Physik 17: 891; English translation On the Electrodynamics of Moving Bodies by George Barker Jeffery and Wilfrid Perrett (1923); Another English translation On the Electrodynamics of Moving Bodies by Megh Nad Saha (1920).
  180. ISBN 978-0-321-85656-2
    .
  181. ISBN 0-471-30932-X
    .
  182. ISBN 978-0-9728111-3-2
    .
  183. ^ Clancy, L.J., Aerodynamics, Section 3.5
  184. ^ Stagnation Pressure at Eric Weisstein's World of Physics (Wolfram Research)
  185. ISBN 978-0-19-954145-4
    .
  186. ^ Romijn, Jan-Willem (2014). "Philosophy of statistics". Stanford Encyclopedia of Philosophy.
  187. ^ "Cambridge Dictionary".
  188. ISBN 0-19-920613-9
  189. ^ Chegg Study chegg.com Archived 2021-08-25 at the Wayback Machine Retrieved August 2021
  190. ^ Bohren, Craig F.; Huffman, Donald R. (1998). Absorption and scattering of light by small particles. Wiley. pp. 123–126.
    ISBN 978-0-471-29340-8
    .
  191. ^ Narimanov, Evgenii E.; Smolyaninov, Igor I. (2012). "Beyond Stefan–Boltzmann Law: Thermal Hyper-Conductivity". Conference on Lasers and Electro-Optics 2012. OSA Technical Digest. Optical Society of America. pp. QM2E.1.
    S2CID 36550833
    .
  192. PMID 10853758
    . Stiffness" = "Load" divided by "Deformation
  193. ISBN 978-0-7619-6349-3
  194. ^ a b Degarmo, Black & Kohser 2003, p. 60.
  195. doi:10.1016/s0032-3861(03)00112-5
  196. doi:10.1103/physrev.100.1607
  197. ^ Smith & Hashemi 2006, p. 246.
  198. ^ "Science Direct: Structural Analysis" Archived 2021-05-16 at the Wayback Machine
  199. ISBN 0-7844-0809-2
    .
  200. ^ "1.5.3.1". Eurocode 0: Basis of structural design EN 1990. Bruxelles: European Committee for Standardization. 2002.
  201. ISBN 0-07-004997-1
    .
  202. ^ "Sublimate". Merriam-Webster.com Dictionary.
  203. ISBN 0-03-072373-6
    .
  204. PMID 26796663
    .
  205. ^ "Sublime". Dictionary.com Unabridged (Online). n.d.
  206. S2CID 10542804
    .
  207. ^ Brooks, R. (1986). "Asynchronous distributed control system for a mobile robot.". SPIE Conference on Mobile Robots. pp. 77–84.[permanent dead link]
  208. ^ Brooks, R. A., "A Robust Programming Scheme for a Mobile Robot", Proceedings of NATO Advanced Research Workshop on Languages for Sensor-Based Control in Robotics, Castelvecchio Pascoli, Italy, September 1986.
  209. ISBN 0677000804
    , p. 73
  210. ISBN 978-1-4381-0949-7
    .
  211. ISBN 978-0-7503-0051-3
    .
  212. ISBN 978-0-7503-0721-5
    .
  213. S2CID 34588568
    .
  214. ISBN 0-387-22045-3
    . p. 198
  215. ^ Veprek, S.; Zeer, A. and Riedel, R. (2000) in Handbook of Ceramic Hard Materials, R. Riedel (ed.). Wiley, Weinheim.
    ISBN 3-527-29972-6
  216. PMID 18063772
    .
  217. ^ Weisstein, Eric W. "Chain Rule". Wolfram MathWorld. Wolfram Research. Retrieved 2 August 2016.
  218. ISBN 978-0-8194-4506-3
    .
  219. ISBN 978-81-219-2082-7
    .
  220. ^ Jastrzebski, D. (1959). Nature and Properties of Engineering Materials (Wiley International ed.). John Wiley & Sons, Inc.
  221. ^ a b "Generic MMPDS Mechanical Properties Table". stressebook.com. 6 December 2014. Archived from the original on 1 December 2017. Retrieved 27 April 2018.
  222. ^ a b Degarmo, Black & Kohser 2003, p. 31
  223. ^ a b Smith & Hashemi 2006, p. 223
  224. ISBN 978-3-540-20785-6
    .
  225. ISBN 978-0-87170-806-9
    .
  226. ^ Davis 2004, p. 33.
  227. ^ Einstein A. (1916), Relativity: The Special and General Theory  (Translation 1920), New York: H. Holt and Company
  228. ^ Einstein, Albert (November 28, 1919). "Time, Space, and Gravitation" . The Times.
  229. ^ Will, Clifford M (2010). "Relativity". Grolier Multimedia Encyclopedia. Retrieved 2010-08-01.
  230. ISBN 0-07-061285-4
    , p. 2
  231. ISBN 0-534-40842-7
    .
  232. ^ a b "Toughness", NDT Education Resource Center Archived 2020-04-11 at the Wayback Machine, Brian Larson, editor, 2001–2011, The Collaboration for NDT Education, Iowa State University
  233. OCLC 903959750.{{cite book}}: CS1 maint: location missing publisher (link
    )
  234. ^ Metha, Rohit. "11". The Principles of Physics. p. 378.
  235. ^ Agarwal, Anant. Foundations of Analog and Digital Electronic Circuits.Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 2005, p. 43
  236. ISBN 978-0-240-82100-9
    .
  237. ^ Klein, Christian Felix (1924) [1902]. Elementarmathematik vom höheren Standpunkt aus: Arithmetik, Algebra, Analysis (in German). 1 (3rd ed.). Berlin: J. Springer.
  238. ^ Klein, Christian Felix (2004) [1932]. Elementary Mathematics from an Advanced Standpoint: Arithmetic, Algebra, Analysis. Translated by Hedrick, E. R.; Noble, C. A. (Translation of 3rd German ed.). Dover Publications, Inc. / The Macmillan Company. ISBN 978-0-48643480-3. Archived from the original on 2018-02-15. Retrieved 2017-08-13.
  239. ^ R. Nagel (ed.), Encyclopedia of Science, 2nd Ed., The Gale Group (2002)
  240. ^ Boyer (1991), p. [page needed].
  241. ^
    doi:10.1351/goldbook.T06502
    .
  242. ISBN 9780534420123
    .
  243. ^ "Definition of TRUSS". 8 April 2023.
  244. ISBN 978-0-07-338029-2
    .
  245. ^ Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print.
  246. ^ Logan, Earl. "Handbook of turbomachinery". 1995. Marcel Deckker.
  247. ^ Vandad Talimi (Original author unknown). "Mechanical Equipment and Systems". 2013. Memorial University of Newfoundland. http://www.engr.mun.ca/~yuri/Courses/MechanicalSystems/Turbomachinery.pdf Archived 2018-02-19 at the Wayback Machine
  248. ^ Batchelor, G. (2000). Introduction to Fluid Mechanics.
  249. ^ Sen, D. (2014). "The Uncertainty relations in quantum mechanics" (PDF). Current Science. 107 (2): 203–218.
  250. ISBN 0-9762548-3-2
    .
  251. ISBN 978-3-540-26205-3
    .
  252. ISBN 978-0-07-326807-1
    .
  253. OL 7221486M
    .
  254. ISBN 0-471-90759-6
    .
  255. ^
    ISBN 978-0471215042
    .
  256. ^ Biography on Nobel prize website. Nobelprize.org (1 March 1911). Retrieved on 2013-11-08.
  257. ^ Meyers and Chawla (1999): "Mechanical Behavior of Materials", 98-103.
  258. ^ "viscosity". Merriam-Webster Dictionary. 22 May 2023.
  259. ISBN 978-0-201-07392-8
    .
  260. ^ Ciletti, M. D., Irwin, J. D., Kraus, A. D., Balabanian, N., Bickard, T. A., and Chan, S. P. (1993). Linear circuit analysis. In Electrical Engineering Handbook, edited by R. C. Dorf. Boca Raton: CRC Press. (pp.82–87)
  261. ISBN 0-7381-2601-2
    , page 23
  262. ISBN 978-0-13-093083-5
    .
  263. ^ "SI Brochure, 8th ed". Archived from the original on 2019-03-21. Retrieved 2021-10-02.
  264. ^ Council Directive on units of measurements 80/181/EEC Chapter 1.2.3., p. 6: "Special names for the unit of power: the name volt–ampere (symbol ‘VA’) when it is used to express the apparent power of alternating electric current, and var (symbol ‘var’) when it is used to express reactive electric power."
  265. ^ IUPAC Gold Book, definition of contact (Volta) potential difference.
  266. ^
    ISBN 92-822-2213-6, archived
    (PDF) from the original on 2021-06-04, retrieved 2021-12-16, p. 144
  267. ^ "Von Mises Criterion (Maximum Distortion Energy Criterion)". Engineer's edge. Retrieved 8 February 2018.
  268. ^ von Mises, R. (1913). Mechanik der festen Körper im plastisch deformablen Zustand. Göttin. Nachr. Math. Phys., vol. 1, pp. 582–592.
  269. ^ Pragnan Chakravorty, "What Is a Signal? [Lecture Notes]," IEEE Signal Processing Magazine, vol. 35, no. 5, pp. 175-177, Sept. 2018. https://doi.org/10.1109/MSP.2018.2832195
  270. ^ Hecht, Eugene (1987). Optics (2nd ed.). Addison Wesley. pp. 15–16.
    ISBN 978-0-201-11609-0
    .
  271. ^ Brian Hilton Flowers (2000). "§21.2 Periodic functions". An introduction to numerical methods in C++ (2nd ed.). Cambridge University Press. p. 473.
    ISBN 978-0-19-850693-5
    .
  272. ^ Raymond A. Serway; John W. Jewett (2006). Principles of physics (4th ed.). Cengage Learning. pp. 404, 440.
    ISBN 978-0-534-49143-7
    .
  273. ^ A. A. Sonin (1995). The surface physics of liquid crystals. Taylor & Francis. p. 17.
    ISBN 978-2-88124-995-2
    .
  274. ^ Keqian Zhang & Dejie Li (2007). Electromagnetic Theory for Microwaves and Optoelectronics. Springer. p. 533.
    ISBN 978-3-540-74295-1
    .
  275. ^ Bowser, Edward Albert (1920), An elementary treatise on analytic mechanics: with numerous examples (25th ed.), D. Van Nostrand Company, pp. 202–203.
  276. ^ McGraw-Hill Concise Encyclopedia of Science & Technology, Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, p. 2041.
  277. ^ Wheel and Axle, The World Book Encyclopedia, World Book Inc., 1998, pp. 280-281
  278. ISBN 0-19-920613-9
    (entry for "winsorized estimation")
  279. ^ Wiktionary
  280. ^ Wiktionary
  281. ^ Wiktionary

Sources

Retrieved from "https://en.wikipedia.org/w/index.php?title=Glossary_of_engineering:_M–Z&oldid=1227916205"