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Time–temperature Superposition
The time–temperature superposition principle is a concept in polymer physics and in the physics of glass-forming liquids. This superposition principle is used to determine temperature-dependent mechanical properties of linear viscoelastic materials from known properties at a reference temperature. The elastic moduli of typical amorphous polymers increase with loading rate but decrease when the temperature is increased.Experiments that determine the mechanical properties of polymers often use periodic loading. For such situations, the loading rate is related to the frequency of the applied load. Curves of the instantaneous modulus as a function of time do not change shape as the temperature is changed but appear only to shift left or right. This implies that a master curve at a given temperature can be used as the reference to predict curves at various temperatures by applying a shift operation. The time-temperature superposition principle of linear viscoelasticity is based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheology
Rheology (; ) is the study of the flow of matter, primarily in a fluid (liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with Plasticity (physics), plastic flow rather than deforming Elasticity (physics), elastically in response to an applied force. Rheology is a branch of physics, and it is the science that deals with the Deformation (physics), deformation and flow of materials, both solids and liquids.W. R. Schowalter (1978) Mechanics of Non-Newtonian Fluids Pergamon The term ''wikt:rheology, rheology'' was coined by Eugene C. Bingham, a professor at Lafayette College, in 1920, from a suggestion by a colleague, Markus Reiner.The Deborah Number The term was inspired by the aphorism of Heraclitus (often mistakenly attributed to Simplicius of Cilicia, Simplicius), (, 'everything flows' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer Physics
Polymer physics is the field of physics that studies polymers, their fluctuations, mechanical properties, as well as the kinetics of reactions involving degradation and polymerisation of polymers and monomers respectively.P. Flory, ''Principles of Polymer Chemistry'', Cornell University Press, 1953. .Pierre Gilles De Gennes, ''Scaling Concepts in Polymer Physics'' CORNELL UNIVERSITY PRESS Ithaca and London, 1979M. Doi and S. F. Edwards, ''The Theory of Polymer Dynamics'' Oxford University Inc NY, 1986 While it focuses on the perspective of condensed matter physics, polymer physics is originally a branch of statistical physics. Polymer physics and polymer chemistry are also related with the field of polymer science, where this is considered the applicative part of polymers. Polymers are large molecules and thus are very complicated for solving using a deterministic method. Yet, statistical approaches can yield results and are often pertinent, since large polymers (i.e., polymers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature Dependence Of Liquid Viscosity
Viscosity depends strongly on temperature. In liquids it usually decreases with increasing temperature, whereas, in most gases, viscosity ''increases'' with increasing temperature. This article discusses several models of this dependence, ranging from rigorous first-principles calculations for monatomic gases, to empirical correlations for liquids. Understanding the temperature dependence of viscosity is important in many applications, for instance engineering lubricants that perform well under varying temperature conditions (such as in a car engine), since the performance of a lubricant depends in part on its viscosity. Engineering problems of this type fall under the purview of tribology. Here dynamic viscosity is denoted by \mu and kinematic viscosity by \nu. The formulas given are valid only for an absolute temperature scale; therefore, unless stated otherwise temperatures are in kelvins. Physical causes Viscosity in gases arises from molecules traversing layers of flow and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscoelasticity
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly with time when a 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 bond stretching along crystallographic planes in an ordered solid, viscosity is the result of the diffusion of atoms or molecules inside an amorphous material.Meyers and Chawla (1999): "Mechanical Behavior of Materials", 98-103. Background In the nineteenth century, physicists such as Maxwell, Boltzmann, and Kelvin researched and experimented with creep and recovery of glasses, metals, and rubbers. Viscoelasticity was further examined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). The Kelvin scale is an absolute thermodynamic temperature scale, meaning it uses absolute zero as its null (zero) point. Historically, the Kelvin scale was developed by shifting the starting point of the much-older Celsius scale down from the melting point of water to absolute zero, and its increments still closely approximate the historic definition of a degree Celsius, but since 2019 the scale has been defined by fixing the Boltzmann constant to be exactly . Hence, one kelvin is equal to a change in the thermodynamic temperature that results in a change of thermal energy by . The temperature in degree Celsius is now defined as the temperature in kelvins minus 273.15, meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Curve - Frequency-temperature Superposition Principle
Master or masters may refer to: Ranks or titles * Ascended master, a term used in the Theosophical religious tradition to refer to spiritually enlightened beings who in past incarnations were ordinary humans * Grandmaster (chess), National Master, International Master, FIDE Master, Candidate Master, all ranks of chess player *Grandmaster (martial arts) or Master, an honorary title * Grand master (order), a title denoting the head of an order or knighthood *Grand Master (Freemasonry), the head of a Grand Lodge and the highest rank of a Masonic organization *Maestro, an orchestral conductor, or the master within some other musical discipline *Master, a title of Jesus in the New Testament *Master or shipmaster, the sea captain of a merchant vessel * Master (college), head of a college * Master (form of address), an English honorific for boys and young men *Master (judiciary), a judicial official in the courts of common law jurisdictions *Master mariner, a licensed mariner who is qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Curves On Polymer
Master or masters may refer to: Ranks or titles * Ascended master, a term used in the Theosophical religious tradition to refer to spiritually enlightened beings who in past incarnations were ordinary humans * Grandmaster (chess), National Master, International Master, FIDE Master, Candidate Master, all ranks of chess player *Grandmaster (martial arts) or Master, an honorary title * Grand master (order), a title denoting the head of an order or knighthood *Grand Master (Freemasonry), the head of a Grand Lodge and the highest rank of a Masonic organization *Maestro, an orchestral conductor, or the master within some other musical discipline *Master, a title of Jesus in the New Testament *Master or shipmaster, the sea captain of a merchant vessel * Master (college), head of a college * Master (form of address), an English honorific for boys and young men *Master (judiciary), a judicial official in the courts of common law jurisdictions *Master mariner, a licensed mariner who is qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decadic Logarithm
In mathematics, the common logarithm is the logarithm with base 10. It is also known as the decadic logarithm and as the decimal logarithm, named after its base, or Briggsian logarithm, after Henry Briggs (mathematician), Henry Briggs, an English mathematician who pioneered its use, as well as standard logarithm. Historically, it was known as ''logarithmus decimalis'' or ''logarithmus decadis''. It is indicated by , , or sometimes with a capital (however, this notation is ambiguous, since it can also mean the complex natural logarithmic multi-valued function). On calculators, it is printed as "log", but mathematicians usually mean natural logarithm (logarithm with base e ≈ 2.71828) rather than common logarithm when they write "log". To mitigate this ambiguity, the ISO 80000-2, ISO 80000 specification recommends that should be written , and should be . Before the early 1970s, handheld electronic calculators were not available, and mechanical calculators capable of multiplica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John D
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died c. AD 30), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (lived c. AD 30), one of the twelve apostles of Jesus * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle and Saint Peter * Pope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shift Factor Against Test Temperatures Relative To A Reference Temperature
Shift may refer to: Art, entertainment, and media Gaming * ''Shift'' (series), a 2008 online video game series by Armor Games * '' Need for Speed: Shift'', a 2009 racing video game ** '' Shift 2: Unleashed'', its 2011 sequel Literature * ''Shift'' (novel), a 2010 alternative history book by Tim Kring and Dale Peck * ''Shift'' (novella), a 2013 science fiction book, part two of the Silo trilogy by Hugh Howey * Shift the Ape, a character in ''The Chronicles of Narnia'' novel series Music * ''Shift'' (Nasum album), 2004 * Shift (The Living End album) * Shift (music), a change of level in music * Shift (string technique), a finger movement from one position to another on the same string Other uses in arts, entertainment, and media * ''Shift'' (magazine), a former Canadian technology and culture magazine * Shift (MSNBC), an online live-streaming video network * ''Shift'' (sculpture), an outdoor sculpture by American artist Richard Serra located in King City, Ontario, Canad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boltzmann Constant
The Boltzmann constant ( or ) is the proportionality factor that relates the average relative kinetic energy of particles in a gas with the thermodynamic temperature of the gas. It occurs in the definitions of the kelvin and the gas constant, and in Planck's law of black-body radiation and Boltzmann's entropy formula, and is used in calculating thermal noise in resistors. The Boltzmann constant has dimensions of energy divided by temperature, the same as entropy. It is named after the Austrian scientist Ludwig Boltzmann. As part of the 2019 redefinition of SI base units, the Boltzmann constant is one of the seven " defining constants" that have been given exact definitions. They are used in various combinations to define the seven SI base units. The Boltzmann constant is defined to be exactly . Roles of the Boltzmann constant Macroscopically, the ideal gas law states that, for an ideal gas, the product of pressure and volume is proportional to the product of amount ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
