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Gough–Joule Effect
The Gough–Joule effect (a.k.a. Gow–Joule effect) is originally the tendency of elastomers to contract when heated if they are under tension. Elastomers that are not under tension do not see this effect. The term is also used more generally to refer to the dependence of the temperature of any solid on the mechanical deformation. This effect can be observed in nylon strings of classical guitars, whereby the string contracts as a result of heating. If an elastic band is first stretched and then subjected to heating, it will shrink rather than expand. This effect was first observed by John Gough in 1802, and was investigated further by James Joule in the 1850s, when it then became known as the Gough–Joule effect. ''Examples in Literature:'' * Popular Science magazine, January 1972: "A stretched piece of rubber ''contracts'' when heated. In doing so, it exerts a measurable increase in its pull. This surprising property of rubber was first observed by James Prescott Joule about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomer
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tension (physics)
In physics, tension is described as the pulling force transmitted axially by the means of a string, a rope, chain, or similar object, or by each end of a rod, truss member, or similar three-dimensional object; tension might also be described as the action-reaction pair of forces acting at each end of said elements. Tension could be the opposite of compression (physics), compression. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. Tension (as a transmitted force, as an action-reaction pair of forces, or as a restoring force) is measured in newton (unit), newtons in the International System of Units (or pounds-force in Imperial units). The ends of a string or other object transmitt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Gough (natural Philosopher)
John Gough ( ; 17 January 1757 – 28 July 1825) was a blind English natural and experimental philosopher who is known for his own investigations as well as the influence he had on both John Dalton and William Whewell. Life John Gough was born in Kendal, Westmorland, on 17 January 1757, the eldest child of Nathan Gough (d. 1800) and his wife, Susannah (1731–1798). Gough's father was a wool dyer and shearman dyer, while his mother was the eldest daughter of John Wilson, a prosperous farmer with an estate on the west bank of Windermere. Nathan and Susannah Gough had three sons and four daughters, one of whom died in infancy. The family belonged to the Society of Friends, whose communities flourished in Cumberland and Westmorland during this period. Before he was three years old, Gough was attacked by smallpox and lost his sight. In his childhood he expended much effort in developing his sense of touch and hearing, and appears to have been especially eager to learn to recognize ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Joule
James Prescott Joule (; 24 December 1818 11 October 1889) was an English physicist, mathematician and brewer, born in Salford, Lancashire. Joule studied the nature of heat, and discovered its relationship to mechanical work (see energy). This led to the law of conservation of energy, which in turn led to the development of the first law of thermodynamics. The SI derived unit of energy, the joule, is named after him. He worked with Lord Kelvin to develop an absolute thermodynamic temperature scale, which came to be called the Kelvin scale. Joule also made observations of magnetostriction, and he found the relationship between the current through a resistor and the heat dissipated, which is also called Joule's first law. His experiments about energy transformations were first published in 1843. Early years James Joule was born in 1818, the son of Benjamin Joule (1784–1858), a wealthy brewer, and his wife, Alice Prescott, on New Bailey Street in Salford. Joule was tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford University Press
Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books by decree in 1586, it is the second oldest university press after Cambridge University Press. It is a department of the University of Oxford and is governed by a group of 15 academics known as the Delegates of the Press, who are appointed by the vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, opposite Somerville College, in the inner suburb of Jericho. For the last 500 years, OUP has primarily focused on the publication of pedagogical texts and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-ring
An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, forming a seal at the interface. The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Dynamic examples include rotating pump shafts and hydraulic cylinder pistons. Static applications of O-rings may include fluid or gas sealing applications in which: (1) the O-ring is compressed resulting in zero clearance, (2) the O-ring material is vulcanized solid such that it is impermeable to the fluid or gas, and (3) the O-ring material is resistant to degradation by the fluid or gas. The wide range of potential liquids and gases that need to be sealed has necessitated the development of a wide range of materials. O-rings are one of the most common seals used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomers
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensed Matter Physics
Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases which arise from electromagnetic forces between atoms. More generally, the subject deals with "condensed" phases of matter: systems of many constituents with strong interactions between them. More exotic condensed phases include the superconducting phase exhibited by certain materials at low temperature, the ferromagnetic and antiferromagnetic phases of spins on crystal lattices of atoms, and the Bose–Einstein condensate found in ultracold atomic systems. Condensed matter physicists seek to understand the behavior of these phases by experiments to measure various material properties, and by applying the physical laws of quantum mechanics, electromagnetism, statistical mechanics, and other theories to develop mathematical models. The diversity of systems and phenomena available for study makes condensed matter phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber Properties
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and Indonesia are three of the leading rubber producers. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the rubber tree (''Hevea brasiliensis'') or others. The latex is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is refined into the rubber that is ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup. The coagulated lumps are collected and processed into dry forms for sale. Natural rubber is used extensively in many applications and products, either alone or in combination with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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