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Chameleon Coating
Chameleon coating, also known as nano composite tribological coating, is an adaptive adhesive that uses nanotechnology to adjust to environmental fluctuations to make living conditions more suitable to the object that the coat has been applied to. Purpose The purpose of chameleon coating is to provide optimal performance of material in any environment. The idea is that when a sudden change in the environment occurs the particular nano coating will change its chemical properties to better suit itself in the environment in order to avoid wear due to friction and abrasion. Chameleon coating is supposed to resolve the issues with fluid hydraulics where atmospheric pressure changes under different environments. The chemical properties of fluid hydraulics alter under different atmospheric pressure because liquids and gases expand and condense under different pressures. Thus the goal of chameleon coating is to provide the same lubrication in machines from fluids such as oil but without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Review Of Materials Research
The ''Annual Review of Materials Research'' is a peer-reviewed journal that publishes review articles about materials science. It has been published by the nonprofit Annual Reviews since 1971, when it was first released under the title the ''Annual Review of Materials Science''. Four people have served as editors, with the current editor Ram Seshadri stepping into the position in 2024. It has an impact factor of 10.6 as of 2024. As of 2023, it is being published as open access, under the Subscribe to Open model. History The ''Annual Review of Materials Science'' was first published in 1971 by the nonprofit publisher Annual Reviews, making it their sixteenth journal. Its first editor was Robert Huggins. In 2001, its name was changed to the current form, the ''Annual Review of Materials Research''. The name change was intended "to better reflect the broad appeal that materials research has for so many diverse groups of scientists and not simply those who identify themselves w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoengineering
Nanoengineering is the practice of engineering on the 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. History * 4th Century Rome: The Lycurgus Cup was crafted using dichroic glass which is a product of nanoengineering * 6th-15th Centuries: Stained glass windows were created in European cathedrals which contained nanoparticles of gold chloride or other metal oxides or chlorides. These nanoparticles give the glass its vibrant colors. * 9th-17th Centuries: A sparkling layer on the outside of ceramics was used containing silver, copper, or other metallic nanoparticles. * 13th-18th Centuries: "Damascus" saber blades were crafted using techniques that resulted in nanotubes and cementite nanowires. * 1950: Victor La Mer and Robert Dinegar created a process that was used to create speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Rate
In physics, mechanics and other areas of science, shear rate is the rate at which a progressive shear strain is applied to some material, causing shearing to the material. Shear rate is a measure of how the velocity changes with distance. Simple shear The shear rate for a fluid flowing between two parallel plates, one moving at a constant speed and the other one stationary ( Couette flow), is defined by :\dot\gamma = \frac, where: *\dot\gamma is the shear rate, measured in reciprocal seconds; * is the velocity of the moving plate, measured in meters per second; * is the distance between the two parallel plates, measured in meters. Or: : \dot\gamma_ = \frac + \frac. For the simple shear case, it is just a gradient of velocity in a flowing material. The SI unit of measurement for shear rate is s−1, expressed as "reciprocal seconds" or " inverse seconds". However, when modelling fluids in 3D, it is common to consider a scalar value for the shear rate by calculating the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond-like Carbon
Diamond-like carbon (DLC) is a class of amorphous carbon material that displays some of the typical properties of diamond. DLC is usually applied as coatings to other materials that could benefit from such properties. DLC exists in seven different forms. All seven contain significant amounts of sp3 hybridized carbon atoms. The reason that there are different types is that even diamond can be found in two crystalline polytypes. The more common one uses a cubic lattice, while the less common one, lonsdaleite, has a hexagonal lattice. By mixing these polytypes at the nanoscale, DLC coatings can be made that at the same time are amorphous, flexible, and yet purely sp3 bonded "diamond". The hardest, strongest, and slickest is tetrahedral amorphous carbon (ta-C). Ta-C can be considered to be the "pure" form of DLC, since it consists almost entirely of sp3 bonded carbon atoms. Fillers such as hydrogen, graphitic sp2 carbon, and metals are used in the other 6 forms to reduce produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. Silver is found in the Earth's crust in the pure, free elemental form ("native metal, native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of the seven metals of antiquity, silver has had an enduring role in most human cultures. Other than in currency and as an in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactivity (chemistry), reactive chemical elements, being the second-lowest in the reactivity series. It is solid under standard temperature and pressure, standard conditions. Gold often occurs in free elemental (native state (metallurgy), native state), as gold nugget, nuggets or grains, in rock (geology), rocks, vein (geology), veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as in electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerospace
Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics and astronautics. Aerospace organizations research, design, manufacture, operate, maintain, and repair both aircraft and spacecraft. The border between space and the atmosphere has been proposed as above the ground according to the physical explanation that the air density is too low for a lifting body to generate meaningful lift force without exceeding orbital velocity. This border has been called the Kármán line. Overview In most industrial countries, the aerospace industry is a co-operation of the public and private sectors. For example, several states have a civilian space program funded by the government, such as NASA, National Aeronautics and Space Administration in the United States, European Space Agency in Europe, the Canadian Space A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersonic
In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at different speeds; these effects collectively become important around Mach 5–10. The hypersonic regime can also be alternatively defined as speeds where specific heat capacity changes with the temperature of the flow as kinetic energy of the moving object is converted into heat. Characteristics of flow While the definition of hypersonic flow can be quite vague and is generally debatable (especially because of the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow. The peculiarities in hyperso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reusable Launch Vehicle
A reusable launch vehicle has parts that can be recovered and reflown, while carrying payloads from the surface to outer space. Rocket stages are the most common launch vehicle parts aimed for reuse. Smaller parts such as fairings, boosters or rocket engines can also be reused, though reusable spacecraft may be launched on top of an expendable launch vehicle. Reusable launch vehicles do not need to make these parts for each launch, therefore reducing its launch cost significantly. However, these benefits are diminished by the cost of recovery and refurbishment. Reusable launch vehicles may contain additional avionics and propellant, making them heavier than their expendable counterparts. Reused parts may need to enter the atmosphere and navigate through it, so they are often equipped with heat shields, grid fins, and other flight control surfaces. By modifying their shape, spaceplanes can leverage aviation mechanics to aid in its recovery, such as gliding or lift. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubrication
Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on the degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements, reduces the rate of wear, and prevents excessive stresses or seizures at bearings. By repelling water and other substances, it also reduces corrosion. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. Lubrication mechanisms Fluid-lubricated systems As the load incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space
Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as '' spacetime''. The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework. In the 19th and 20th centuries mathematicians began to examine geometries that are non-Euclidean, in which space is conceived as '' curved'', rather than '' flat'', as in the Euclidean space. According to Albert Einstein's theory of general relativity, space around gravitational fields deviates from Euclidean space. Experimental tests of general relativity have confirmed that non-Euclidean geometries provide a bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
