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In the field of physical security, security lighting is lighting that intended to deter or detect intrusions or other criminal activity occurring on a property or site. It can also be used to increase a feeling of safety. Lighting is integral to crime prevention through environmental design | https://huggingface.co/datasets/fmars/wiki_stem |
A skylight (sometimes called a rooflight) is a light-permitting structure or window, usually made of transparent or translucent glass, that forms all or part of the roof space of a building for daylighting and ventilation purposes.
History
Open skylights were used in Ancient Roman architecture, such as the oculus of the Pantheon. Glazed 'closed' skylights have been in use since the Industrial Revolution made advances in glass production manufacturing | https://huggingface.co/datasets/fmars/wiki_stem |
The Solight Design, Inc. makes rechargeable solar lanterns, invented by Alice Min Soo Chun.
Products
Solight Design offers portable, cube-shaped, water-resistant solar lanterns that fold flat when not in use | https://huggingface.co/datasets/fmars/wiki_stem |
A staircase timer is an electrical switch used to control lighting on a staircase, corridor or lobby. A single action turns on the lights and they remain on for long enough to ascend or descend the stairs. The lights then turn themselves off automatically | https://huggingface.co/datasets/fmars/wiki_stem |
Sustainable lighting is lighting designed with energy efficient light sources. "There are simple design strategies and some materials that can facilitate the energy saving advantages of natural light. Light colored interiors and open floor plans are good choices | https://huggingface.co/datasets/fmars/wiki_stem |
Often task lighting refers to increasing illuminance to better accomplish a specific activity. However, the illuminance level is not the only factor governing visibility. Contrast is also important, and a poorly positioned light source may cause contrast reduction, resulting in loss of visibility | https://huggingface.co/datasets/fmars/wiki_stem |
Temporal Light Artefacts (TLAs) are undesired effects in the visual perception of a human observer induced by temporal light modulations. Two well-known examples of such unwanted effects are flicker and stroboscopic effect. The term 'flicker' refers to directly visible light modulations at relatively low frequencies (< 80 Hz) and small modulation levels | https://huggingface.co/datasets/fmars/wiki_stem |
Temporal light effects (TLEs) is the general term for all possible effects resulting from temporal light modulations (TLMs).
Root cause
Light emitted from lighting equipment such as luminaires and lamps may vary in strength as function of time, either intentionally or unintentionally. Intentional light variations are applied amongst others for warning, signalling (e | https://huggingface.co/datasets/fmars/wiki_stem |
Temporal light interference (TLI) is an unacceptable degradation of the performance of an equipment or system that has an optical input for its intended functioning and is caused by a temporal light modulation disturbance. A temporal light modulation (TLM) disturbance may be either an intentional or unintentional temporal light modulation (TLM) of lighting equipment such as luminaires or lamps. Examples of equipment that can be interfered are barcode scanners, cameras and test equipment | https://huggingface.co/datasets/fmars/wiki_stem |
A Tensor lamp is a trademarked brand of small high-intensity low-voltage desk lamp invented by Jay Monroe. The lamp was mainly popular during the 1960s and 1970s. The lamp was originally used by doctors and dentists, and later became more widely used | https://huggingface.co/datasets/fmars/wiki_stem |
Thermally activated delayed fluorescence (TADF) is a process through which a molecular species in a non-emitting excited state can incorporate surrounding thermal energy to change states and only then undergo light emission. The TADF process involves an excited molecular species in a triplet state, which commonly has a forbidden transition to the ground state termed phosphorescence. By absorbing nearby thermal energy the triplet state can undergo reverse intersystem crossing (RISC) converting it to a singlet state, which can then de-excite to the ground state and emit light in a process termed fluorescence | https://huggingface.co/datasets/fmars/wiki_stem |
Artificial lighting technology began to be developed tens of thousands of years ago and continues to be refined in the present day.
Antiquity
125,000 BC Widespread control of fire by early humans.
17,500 BC oldest documented lamp, utilizing animal fat as fuel
c | https://huggingface.co/datasets/fmars/wiki_stem |
Aleksandra M. Walczak is a theoretical biophysicist. She works on stochastic gene expression at Ecole Normale Supérieure where she is a research director | https://huggingface.co/datasets/fmars/wiki_stem |
A pole figure is a graphical representation of the orientation of objects in space. For example, pole figures in the form of stereographic projections are used to represent the orientation distribution of crystallographic lattice planes in crystallography and texture analysis in materials science.
Definition
Consider an object with a basis attached to it | https://huggingface.co/datasets/fmars/wiki_stem |
Poly(amidoamine), or PAMAM, is a class of dendrimer which is made of repetitively branched subunits of amide and amine functionality. PAMAM dendrimers, sometimes referred to by the trade name Starburst, have been extensively studied since their synthesis in 1985, and represent the most well-characterized dendrimer family as well as the first to be commercialized. Like other dendrimers, PAMAMs have a sphere-like shape overall, and are typified by an internal molecular architecture consisting of tree-like branching, with each outward 'layer', or generation, containing exponentially more branching points | https://huggingface.co/datasets/fmars/wiki_stem |
Adsorption of polyelectrolytes on solid substrates is a surface phenomenon where long-chained polymer molecules with charged groups (dubbed polyelectrolytes) bind to a surface that is charged in the opposite polarity. On the molecular level, the polymers do not actually bond to the surface, but tend to "stick" to the surface via intermolecular forces and the charges created by the dissociation of various side groups of the polymer. Because the polymer molecules are so long, they have a large amount of surface area with which to contact the surface and thus do not desorb as small molecules are likely to do | https://huggingface.co/datasets/fmars/wiki_stem |
Adsorption is the adhesion of ions or molecules onto the surface of another phase. Adsorption may occur via physisorption and chemisorption. Ions and molecules can adsorb to many types of surfaces including polymer surfaces | https://huggingface.co/datasets/fmars/wiki_stem |
Polymer science or macromolecular science is a subfield of materials science concerned with polymers, primarily synthetic polymers such as plastics and elastomers. The field of polymer science includes researchers in multiple disciplines including chemistry, physics, and engineering.
Subdisciplines
This science comprises three main sub-disciplines:
Polymer chemistry or macromolecular chemistry is concerned with the chemical synthesis and chemical properties of polymers | https://huggingface.co/datasets/fmars/wiki_stem |
The Portevin–Le Chatelier (PLC) effect describes a serrated stress–strain curve or jerky flow, which some materials exhibit as they undergo plastic deformation, specifically inhomogeneous deformation. This effect has been long associated with dynamic strain aging or the competition between diffusing solutes pinning dislocations and dislocations breaking free of this stoppage. The onset of the PLC effect occurs when the strain rate sensitivity becomes negative and inhomogeneous deformation starts | https://huggingface.co/datasets/fmars/wiki_stem |
A powder is an assembly of dry particles dispersed in air. If two different powders are mixed perfectly, theoretically, three types of powder mixtures can be obtained: the random mixture, the ordered mixture or the interactive mixture.
Different powder types
A powder is called free-flowing if the particles do not stick together | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, a precipitate-free zone (PFZ) refers to microscopic localized regions around grain boundaries that are free of precipitates (solid impurities forced outwards from the grain during crystallization). It is a common phenomenon that arises in polycrystalline materials (crystalline materials with stochastically-oriented grains) where heterogeneous nucleation of precipitates is the dominant nucleation mechanism. This is because grain boundaries are high-energy surfaces that act as sinks for vacancies, causing regions adjacent to a grain boundary to be devoid of vacancies | https://huggingface.co/datasets/fmars/wiki_stem |
Pseudoelasticity, sometimes called superelasticity, is an elastic (reversible) response to an applied stress, caused by a phase transformation between the austenitic and martensitic phases of a crystal. It is exhibited in shape-memory alloys.
Overview
Pseudoelasticity is from the reversible motion of domain boundaries during the phase transformation, rather than just bond stretching or the introduction of defects in the crystal lattice (thus it is not true superelasticity but rather pseudoelasticity) | https://huggingface.co/datasets/fmars/wiki_stem |
PTFE fiber is a chemically resistant material. It is used in woven form in certain pump packings as well as in nonwoven form in hot gas bag filters for industries with corrosive exhausts. Because PTFE is relatively insoluble and has a very high melting point, PTFE fibers can not be fashioned from conventional melt or solution spinning | https://huggingface.co/datasets/fmars/wiki_stem |
A pugmill, pug mill, or commonly just pug, is a machine in which clay or other materials are extruded in a plastic state or a similar machine for the trituration of ore. Industrial applications are found in pottery, bricks, cement and some parts of the concrete and asphalt mixing processes. A pugmill may be a fast continuous mixer | https://huggingface.co/datasets/fmars/wiki_stem |
Puncture resistance denotes the relative ability of a material or object to inhibit the intrusion of a foreign object. This is defined by a test method, regulation, or technical specification. It can be measured in several ways ranging from a slow controlled puncture to a rapid impact of a sharp object or a rounded probe | https://huggingface.co/datasets/fmars/wiki_stem |
Quantum materials is an umbrella term in condensed matter physics that encompasses all materials whose essential properties cannot be described in terms of semiclassical particles and low-level quantum mechanics. These are materials that present strong electronic correlations or some type of electronic order, such as superconducting or magnetic orders, or materials whose electronic properties are linked to non-generic quantum effects – topological insulators, Dirac electron systems such as graphene, as well as systems whose collective properties are governed by genuinely quantum behavior, such as ultra-cold atoms, cold excitons, polaritons, and so forth. On the microscopic level, four fundamental degrees of freedom – that of charge, spin, orbit and lattice – become intertwined, resulting in complex electronic states; the concept of emergence is a common thread in the study of quantum materials | https://huggingface.co/datasets/fmars/wiki_stem |
Radiation materials science is a subfield of materials science which studies the interaction of radiation with matter: a broad subject covering many forms of irradiation and of matter.
Main aim of radiation material science
Some of the most profound effects of irradiation on materials occur in the core of nuclear power reactors where atoms comprising the structural components are displaced numerous times over the course of their engineering lifetimes. The consequences of radiation to core components includes changes in shape and volume by tens of percent, increases in hardness by factors of five or more, severe reduction in ductility and increased embrittlement, and susceptibility to environmentally induced cracking | https://huggingface.co/datasets/fmars/wiki_stem |
The rainflow-counting algorithm is used in calculating the fatigue life of a component in order to convert a uniaxial loading sequence of varying stress into an equivalent set of constant amplitude stress reversals. The method successively extracts the smaller interruption cycles from a sequence, which models the material memory effect seen with stress-strain hysteresis cycles. This simplification allows the number of cycles until failure of a component to be determined for each rainflow cycle using either Miner's rule to calculate the fatigue damage, or in a crack growth equation to calculate the crack increments | https://huggingface.co/datasets/fmars/wiki_stem |
Reaction bonded silicon carbide, also known as siliconized silicon carbide or SiSiC, is a type of silicon carbide that is manufactured by a chemical reaction between porous carbon or graphite with molten silicon. Due to the left over traces of silicon, reaction bonded silicon carbide is often referred to as siliconized silicon carbide, or its abbreviation SiSiC. If pure silicon carbide is produced by sintering of silicon carbide powder, it usually contains traces of chemicals called sintering aids, which are added to support the sintering process by allowing lower sintering temperatures | https://huggingface.co/datasets/fmars/wiki_stem |
In metallurgy, recovery is a process by which a metal or alloy's deformed grains can reduce their stored energy by the removal or rearrangement of defects in their crystal structure. These defects, primarily dislocations, are introduced by plastic deformation of the material and act to increase the yield strength of a material. Since recovery reduces the dislocation density, the process is normally accompanied by a reduction in a material's strength and a simultaneous increase in the ductility | https://huggingface.co/datasets/fmars/wiki_stem |
Reinforced concrete, also called ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete | https://huggingface.co/datasets/fmars/wiki_stem |
A peculiarity of thermal motion of very long linear macromolecules in entangled polymer melts or concentrated polymer solutions is reptation. Derived from the word reptile, reptation suggests the movement of entangled polymer chains as being analogous to snakes slithering through one another. Pierre-Gilles de Gennes introduced (and named) the concept of reptation into polymer physics in 1971 to explain the dependence of the mobility of a macromolecule on its length | https://huggingface.co/datasets/fmars/wiki_stem |
Reticulated foam is a very porous, low density solid foam. 'Reticulated' means like a net. Reticulated foams are extremely open foams i | https://huggingface.co/datasets/fmars/wiki_stem |
Retrogression heat treatment (RHT) is a heat treatment process that rapidly heat treats age-hardenable aluminum alloys. Mainly induction heating is used for RHT. In the past, it was mainly used for 6061 and 6063 aluminum alloys | https://huggingface.co/datasets/fmars/wiki_stem |
Reverse roll coating is a roll-to-roll coating method for wet coatings. It is distinguished from other roll coating methods by having two reverse-running nips. The metering roll and the applicator roll contra-rotate, with an accurate gap between them | https://huggingface.co/datasets/fmars/wiki_stem |
Rigid unit modes (RUMs) represent a class of lattice vibrations or phonons that exist in network materials such as quartz, cristobalite or zirconium tungstate. Network materials can be described as three-dimensional networks of polyhedral groups of atoms such as SiO4 tetrahedra or TiO6 octahedra. A RUM is a lattice vibration in which the polyhedra are able to move, by translation and/or rotation, without distorting | https://huggingface.co/datasets/fmars/wiki_stem |
Rigidity theory, or topological constraint theory, is a tool for predicting properties of complex networks (such as glasses) based on their composition. It was introduced by James Charles Phillips in 1979 and 1981, and refined by Michael Thorpe in 1983. Inspired by the study of the stability of mechanical trusses as pioneered by James Clerk Maxwell, and by the seminal work on glass structure done by William Houlder Zachariasen, this theory reduces complex molecular networks to nodes (atoms, molecules, proteins, etc | https://huggingface.co/datasets/fmars/wiki_stem |
The room-temperature densification method was developed for Li2MoO4 ceramics and is based on the water-solubility of Li2MoO4. It can be used for the fabrication of Li2MoO4 ceramics instead of conventional thermal sintering. The method utilizes a small amount of aqueous phase formed by moistening the Li2MoO4 powder | https://huggingface.co/datasets/fmars/wiki_stem |
The Rosiwal scale is a hardness scale in mineralogy, with its name given in memory of the Austrian geologist August Karl Rosiwal. The Rosiwal scale attempts to give more quantitative values of scratch hardness, unlike the Mohs scale which is a qualitative measurement with relative values.
The Rosiwal method (also called the Delesse-Rosiwal method) is a method of petrographic analysis and is performed by scratching a polished surface under a known load using a scratch-tip with a known geometry | https://huggingface.co/datasets/fmars/wiki_stem |
Rot-proof or rot resistant is a condition of preservation or protection, by a process or treatment of materials used in industrial manufacturing or production to prevent biodegradation and chemical decomposition. Decomposition is a factor in which organic matter breaks down over time. It is commonly caused by fungus, mold or mildew | https://huggingface.co/datasets/fmars/wiki_stem |
Rubber toughening is a process in which rubber nanoparticles are interspersed within a polymer matrix to increase the mechanical robustness, or toughness, of the material. By "toughening" a polymer it is meant that the ability of the polymeric substance to absorb energy and plastically deform without fracture is increased. Considering the significant advantages in mechanical properties that rubber toughening offers, most major thermoplastics are available in rubber-toughened versions; for many engineering applications, material toughness is a deciding factor in final material selection | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, a general rule of mixtures is a weighted mean used to predict various properties of a composite material . It provides a theoretical upper- and lower-bound on properties such as the elastic modulus, ultimate tensile strength, thermal conductivity, and electrical conductivity. In general there are two models, one for axial loading (Voigt model), and one for transverse loading (Reuss model) | https://huggingface.co/datasets/fmars/wiki_stem |
Rustproofing is the prevention or delay of rusting of iron and steel objects, or the permanent protection against corrosion. Typically, the protection is achieved by a process of surface finishing or treatment. Depending on mechanical wear or environmental conditions, the degradation may not be stopped completely, unless the process is periodically repeated | https://huggingface.co/datasets/fmars/wiki_stem |
Rutherford backscattering spectrometry (RBS) is an analytical technique used in materials science. Sometimes referred to as high-energy ion scattering (HEIS) spectrometry, RBS is used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions (typically protons or alpha particles) impinging on a sample.
Geiger–Marsden experiment
Rutherford backscattering spectrometry is named after Lord Rutherford, a physicist sometimes referred to as the father of nuclear physics | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, Schmid's law (also Schmid factor) describes the slip plane and the slip direction of a stressed material, which can resolve the most shear stress.
Schmid's Law states that the critically resolved shear stress (τ) is equal to the stress applied to the material (σ) multiplied by the cosine of the angle with the vector normal to the glide plane (φ) and the cosine of the angle with the glide direction (λ). Which can be expressed as:
τ
=
m
σ
{\displaystyle \tau =m\sigma }
where m is known as the Schmid factor
m
=
cos
(
ϕ
)
cos
(
λ
)
{\displaystyle m=\cos(\phi )\cos(\lambda )}
Both factors τ and σ are measured in stress units, which is calculated the same way as pressure (force divided by area) | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, segregation is the enrichment of atoms, ions, or molecules at a microscopic region in a materials system. While the terms segregation and adsorption are essentially synonymous, in practice, segregation is often used to describe the partitioning of molecular constituents to defects from solid solutions, whereas adsorption is generally used to describe such partitioning from liquids and gases to surfaces. The molecular-level segregation discussed in this article is distinct from other types of materials phenomena that are often called segregation, such as particle segregation in granular materials, and phase separation or precipitation, wherein molecules are segregated in to macroscopic regions of different compositions | https://huggingface.co/datasets/fmars/wiki_stem |
Selected area (electron) diffraction (abbreviated as SAD or SAED), is a crystallographic experimental technique typically performed using a transmission electron microscope (TEM). It is a specific case of electron diffraction used primarily in material science and solid state physics as one of the most common experimental techniques. Especially with appropriate analytical software, SAD patterns (SADP) can be used to determine crystal orientation, measure lattice constants or examine its defects | https://huggingface.co/datasets/fmars/wiki_stem |
Material selection is a step in the process of designing any physical object. In the context of product design, the main goal of material selection is to minimize cost while meeting product performance goals. Systematic selection of the best material for a given application begins with properties and costs of candidate materials | https://huggingface.co/datasets/fmars/wiki_stem |
A column can buckle due to its own weight with no other direct forces acting on it, in a failure mode called self-buckling. In conventional column buckling problems, the self-weight is often neglected since it is assumed to be small when compared to the applied axial loads. However, when this assumption is not valid, it is important to take the self-buckling into account | https://huggingface.co/datasets/fmars/wiki_stem |
Self-healing materials are artificial or synthetically created substances that have the built-in ability to automatically repair damages to themselves without any external diagnosis of the problem or human intervention. Generally, materials will degrade over time due to fatigue, environmental conditions, or damage incurred during operation. Cracks and other types of damage on a microscopic level have been shown to change thermal, electrical, and acoustical properties of materials, and the propagation of cracks can lead to eventual failure of the material | https://huggingface.co/datasets/fmars/wiki_stem |
Severe plastic deformation (SPD) is a generic term describing a group of metalworking techniques involving very large strains typically involving a complex stress state or high shear, resulting in a high defect density and equiaxed "ultrafine" grain (UFG) size (d < 500 nm) or nanocrystalline (NC) structure (d < 100 nm).
History
The significance of SPD was known from the ancient times, at least during the transition from the Bronze Age to the Iron Age, when repeated hammering and folding was employed for processing strategic tools such as swords. The development of the principles underlying SPD techniques goes back to the pioneering work of P | https://huggingface.co/datasets/fmars/wiki_stem |
A shear band (or, more generally, a 'strain localization') is a narrow zone of intense shearing strain, usually of plastic nature, developing during severe deformation of ductile materials.
As an example, a soil (overconsolidated silty-clay) specimen is shown in Fig. 1, after an axialsymmetric compression test | https://huggingface.co/datasets/fmars/wiki_stem |
Shrink-fitting is a technique in which an interference fit is achieved by a relative size change after assembly. This is usually achieved by heating or cooling one component before assembly and allowing it to return to the ambient temperature after assembly, employing the phenomenon of thermal expansion to make a joint. For example, the thermal expansion of a piece of a metallic drainpipe allows a builder to fit the cooler piece to it | https://huggingface.co/datasets/fmars/wiki_stem |
SiC–SiC matrix composite is a particular type of ceramic matrix composite (CMC) which have been accumulating interest mainly as high temperature materials for use in applications such as gas turbines, as an alternative to metallic alloys. CMCs are generally a system of materials that are made up of ceramic fibers or particles that lie in a ceramic matrix phase. In this case, a SiC/SiC composite is made by having a SiC (silicon carbide) matrix phase and a fiber phase incorporated together by different processing methods | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, slip is the large displacement of one part of a crystal relative to another part along crystallographic planes and directions. Slip occurs by the passage of dislocations on close/packed planes, which are planes containing the greatest number of atoms per area and in close-packed directions (most atoms per length). Close-packed planes are known as slip or glide planes | https://huggingface.co/datasets/fmars/wiki_stem |
Slip bands or stretcher-strain marks are localized bands of plastic deformation in metals experiencing stresses. Formation of slip bands indicates a concentrated unidirectional slip on certain planes causing a stress concentration. Typically, slip bands induce surface steps (e | https://huggingface.co/datasets/fmars/wiki_stem |
Slot-die coating is a coating technique for the application of solution, slurry, or extruded thin films onto typically flat substrates such as glass, metal, paper, fabric or plastic foils. The process was first developed for the industrial production of photographic papers in the 1950's. It has since become relevant in numerous commercial processes and nanomaterials related research fields | https://huggingface.co/datasets/fmars/wiki_stem |
Smart cut is a technological process that enables the transfer of very fine layers of crystalline silicon material onto a mechanical support. It was invented by Michel Bruel of CEA-Leti, and was protected by US patent 5374564. The application of this technological procedure is mainly in the production of silicon-on-insulator (SOI) wafer substrates | https://huggingface.co/datasets/fmars/wiki_stem |
A solid solution, a term popularly used for metals, is a homogeneous mixture of two different kinds of atoms in solid state and having a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solution" is used to describe the intimate mixing of components at the atomic level and distinguishes these homogeneous materials from physical mixtures of components | https://huggingface.co/datasets/fmars/wiki_stem |
Solid-state chemistry, also sometimes referred as materials chemistry, is the study of the synthesis, structure, and properties of solid phase materials. It therefore has a strong overlap with solid-state physics, mineralogy, crystallography, ceramics, metallurgy, thermodynamics, materials science and electronics with a focus on the synthesis of novel materials and their characterization. A diverse range of synthetic techniques, such as the ceramic method and chemical vapour depostion, make solid-state materials | https://huggingface.co/datasets/fmars/wiki_stem |
In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance is completely solid (crystallized).
The solidus temperature, TS or Tsol, specifies the temperature below which a material is completely solid, and the minimum temperature at which a melt can co-exist with crystals in thermodynamic equilibrium. The solidus is applied, among other materials, to metal alloys, ceramics, and natural rocks and minerals | https://huggingface.co/datasets/fmars/wiki_stem |
In a physical or geochemical system, a solvus is a line (binary system) or surface (ternary system) on a phase diagram which separates a homogeneous solid solution from a field of several phases which may form by exsolution or incongruent melting. The line determines a solid solubility limit which changes as a function of temperature. It is a locus of points on the equilibrium diagram | https://huggingface.co/datasets/fmars/wiki_stem |
Specific modulus is a materials property consisting of the elastic modulus per mass density of a material. It is also known as the stiffness to weight ratio or specific stiffness. High specific modulus materials find wide application in aerospace applications where minimum structural weight is required | https://huggingface.co/datasets/fmars/wiki_stem |
The specific strength is a material's (or muscle's) strength (force per unit area at failure) divided by its density. It is also known as the strength-to-weight ratio or strength/weight ratio or strength-to-mass ratio. In fiber or textile applications, tenacity is the usual measure of specific strength | https://huggingface.co/datasets/fmars/wiki_stem |
Spider silk is a protein fibre spun by spiders. Spiders use their silk to make webs or other structures, which function as sticky nets to catch other animals, or as nests or cocoons to protect their offspring, or to wrap up prey. They can also use their silk to suspend themselves, to float through the air, or to glide away from predators | https://huggingface.co/datasets/fmars/wiki_stem |
Spin echo small angle neutron scattering (SESANS) measures structures from around 20 to 2000 nm in size. The information is presented as a real-space (similar to g(r)) as opposed to a reciprocal space (q(r)) mapping. This can simplify the interpretation for some systems | https://huggingface.co/datasets/fmars/wiki_stem |
Spin engineering describes the control and manipulation of quantum spin systems to develop devices and materials. This includes the use of the spin degrees of freedom as a probe for spin based phenomena.
Because of the basic importance of quantum spin for physical and chemical processes, spin engineering is relevant for a wide range of scientific and technological applications | https://huggingface.co/datasets/fmars/wiki_stem |
Spinmechatronics is neologism referring to an emerging field of research concerned with the exploitation of spin-dependent phenomena and established spintronic methodologies and technologies in conjunction with electro-mechanical, magno-mechanical, acousto-mechanical and opto-mechanical systems. Most especially, spinmechatronics (or spin mechatronics) concerns the integration of micro- and nano- mechatronic systems with spin physics and spintronics.
History and origins
While spinmechatronics has been recognised only recently (2008) as an independent field, hybrid spin-mechanical system development dates back to the early nineteen-nineties, with devices combining spintronics and micromechanics emerging at the turn of the twenty-first century | https://huggingface.co/datasets/fmars/wiki_stem |
Spinodal decomposition is a mechanism by which a single thermodynamic phase spontaneously separates into two phases (without nucleation). Decomposition occurs when there is no thermodynamic barrier to phase separation. As a result, phase separation via decomposition does not require the nucleation events resulting from thermodynamic fluctuations, which normally trigger phase separation | https://huggingface.co/datasets/fmars/wiki_stem |
A split-ring resonator (SRR) is an artificially produced structure common to metamaterials. Its purpose is to produce the desired magnetic susceptibility (magnetic response) in various types of metamaterials up to 200 terahertz.
These media create the necessary strong magnetic coupling to an applied electromagnetic field not otherwise available in conventional materials | https://huggingface.co/datasets/fmars/wiki_stem |
In physics, sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas. It occurs naturally in outer space, and can be an unwelcome source of wear in precision components. However, the fact that it can be made to act on extremely fine layers of material is utilised in science and industry—there, it is used to perform precise etching, carry out analytical techniques, and deposit thin film layers in the manufacture of optical coatings, semiconductor devices and nanotechnology products | https://huggingface.co/datasets/fmars/wiki_stem |
Squeeze flow (also called squeezing flow, squeezing film flow, or squeeze flow theory) is a type of flow in which a material is pressed out or deformed between two parallel plates or objects. First explored in 1874 by Josef Stefan, squeeze flow describes the outward movement of a droplet of material, its area of contact with the plate surfaces, and the effects of internal and external factors such as temperature, viscoelasticity, and heterogeneity of the material. Several squeeze flow models exist to describe Newtonian and non-Newtonian fluids undergoing squeeze flow under various geometries and conditions | https://huggingface.co/datasets/fmars/wiki_stem |
The stacking-fault energy (SFE) is a materials property on a very small scale. It is noted as γSFE in units of energy per area.
A stacking fault is an interruption of the normal stacking sequence of atomic planes in a close-packed crystal structure | https://huggingface.co/datasets/fmars/wiki_stem |
The standard linear solid (SLS), also known as the Zener model, is a method of modeling the behavior of a viscoelastic material using a linear combination of springs and dashpots to represent elastic and viscous components, respectively. Often, the simpler Maxwell model and the Kelvin–Voigt model are used. These models often prove insufficient, however; the Maxwell model does not describe creep or recovery, and the Kelvin–Voigt model does not describe stress relaxation | https://huggingface.co/datasets/fmars/wiki_stem |
Sticking coefficient is the term used in surface physics to describe the ratio of the number of adsorbate atoms (or molecules) that adsorb, or "stick", to a surface to the total number of atoms that impinge upon that surface during the same period of time. Sometimes the symbol Sc is used to denote this coefficient, and its value is between 1 (all impinging atoms stick) and 0 (no atoms stick). The coefficient is a function of surface temperature, surface coverage (θ) and structural details as well as the kinetic energy of the impinging particles | https://huggingface.co/datasets/fmars/wiki_stem |
Stopping and Range of Ions in Matter (SRIM) is a group of computer programs which calculate interactions between ions and matter; the core of SRIM is a program called Transport of Ions in Matter (TRIM). SRIM is popular in the ion implantation research and technology community, and also used widely in other branches of radiation material science.
History
SRIM originated in 1980 as a DOS based program then called TRIM | https://huggingface.co/datasets/fmars/wiki_stem |
In nuclear and materials physics, stopping power is the retarding force acting on charged particles, typically alpha and beta particles, due to interaction with matter, resulting in loss of particle kinetic energy.
Its application is important in areas such as radiation protection, ion implantation and nuclear medicine.
Definition and Bragg curve
Both charged and uncharged particles lose energy while passing through matter | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, strain rate is the change in strain (deformation) of a material with respect to time.
The strain rate at some point within the material measures the rate at which the distances of adjacent parcels of the material change with time in the neighborhood of that point. It comprises both the rate at which the material is expanding or shrinking (expansion rate), and also the rate at which it is being deformed by progressive shearing without changing its volume (shear rate) | https://huggingface.co/datasets/fmars/wiki_stem |
The field of strength of materials (also called mechanics of materials) typically refers to various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. The methods employed to predict the response of a structure under loading and its susceptibility to various failure modes takes into account the properties of the materials such as its yield strength, 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 | https://huggingface.co/datasets/fmars/wiki_stem |
Methods have been devised to modify the yield strength, ductility, and toughness of both crystalline and amorphous materials. These strengthening mechanisms give engineers the ability to tailor the mechanical properties of materials to suit a variety of different applications. For example, the favorable properties of steel result from interstitial incorporation of carbon into the iron lattice | https://huggingface.co/datasets/fmars/wiki_stem |
A stress field is the distribution of internal forces in a body that balance a given set of external forces. Stress fields are widely used in fluid dynamics and materials science.
Consider that one can picture the stress fields as the stress created by adding an extra half plane of atoms to a crystal | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, stress relaxation is the observed decrease in stress in response to strain generated in the structure. This is primarily due to keeping the structure in a strained condition for some finite interval of time hence causing some amount of plastic strain. This should not be confused with creep, which is a constant state of stress with an increasing amount of strain | https://huggingface.co/datasets/fmars/wiki_stem |
Striations are marks produced on the fracture surface that show the incremental growth of a fatigue crack. A striation marks the position of the crack tip at the time it was made. The term striation generally refers to ductile striations which are rounded bands on the fracture surface separated by depressions or fissures and can have the same appearance on both sides of the mating surfaces of the fatigue crack | https://huggingface.co/datasets/fmars/wiki_stem |
Strongly correlated materials are a wide class of compounds that include insulators and electronic materials, and show unusual (often technologically useful) electronic and magnetic properties, such as metal-insulator transitions, heavy fermion behavior, half-metallicity, and spin-charge separation. The essential feature that defines these materials is that the behavior of their electrons or spinons cannot be described effectively in terms of non-interacting entities. Theoretical models of the electronic (fermionic) structure of strongly correlated materials must include electronic (fermionic) correlation to be accurate | https://huggingface.co/datasets/fmars/wiki_stem |
Structure field maps (SFMs) or structure maps are visualizations of the relationship between ionic radii and crystal structures for representing classes of materials. The SFM and its extensions has found broad applications in geochemistry, mineralogy, chemical synthesis of materials, and nowadays in materials informatics.
History
The intuitive concept of the SFMs led to different versions of the visualization method established in different domains of materials science | https://huggingface.co/datasets/fmars/wiki_stem |
SU-8 is a commonly used epoxy-based negative photoresist. Negative refers to a photoresist whereby the parts exposed to UV become cross-linked, while the remainder of the film remains soluble and can be washed away during development.
As shown in the structural diagram, SU-8 derives its name from the presence of 8 epoxy groups | https://huggingface.co/datasets/fmars/wiki_stem |
The sublimation sandwich method (also called the sublimation sandwich process and the sublimation sandwich technique) is a kind of physical vapor deposition used for creating man-made crystals. Silicon carbide is the most common crystal grown this way, though others crystals may also be created with it (notably gallium nitride).
In this method, the environment around a single crystal or a polycrystalline plate is filled with vapor heated to between 1600°C and 2100°C-- changes to this environment can affect the gas phase stoichiometry | https://huggingface.co/datasets/fmars/wiki_stem |
Substrate is a term used in materials science and engineering to describe the base material on which processing is conducted. This surface could be used to produce new film or layers of material such as deposited coatings. It could be the base to which paint, adhesives, or adhesive tape is bonded | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, superplasticity is a state in which solid crystalline material is deformed well beyond its usual breaking point, usually over about 400% during tensile deformation. Such a state is usually achieved at high homologous temperature. Examples of superplastic materials are some fine-grained metals and ceramics | https://huggingface.co/datasets/fmars/wiki_stem |
Surface diffusion is a general process involving the motion of adatoms, molecules, and atomic clusters (adparticles) at solid material surfaces. The process can generally be thought of in terms of particles jumping between adjacent adsorption sites on a surface, as in figure 1. Just as in bulk diffusion, this motion is typically a thermally promoted process with rates increasing with increasing temperature | https://huggingface.co/datasets/fmars/wiki_stem |
Surface engineering is the sub-discipline of materials science which deals with the surface of solid matter. It has applications to chemistry, mechanical engineering, and electrical engineering (particularly in relation to semiconductor manufacturing).
Solids are composed of a bulk material covered by a surface | https://huggingface.co/datasets/fmars/wiki_stem |
Surface modification is the act of modifying the surface of a material by bringing physical, chemical or biological characteristics different from the ones originally found on the surface of a material. This modification is usually made to solid materials, but it is possible to find examples of the modification to the surface of specific liquids.
The modification can be done by different methods with a view to altering a wide range of characteristics of the surface, such as: roughness, hydrophilicity, surface charge, surface energy, biocompatibility and reactivity | https://huggingface.co/datasets/fmars/wiki_stem |
Surface states are electronic states found at the surface of materials. They are formed due to the sharp transition from solid material that ends with a surface and are found only at the atom layers closest to the surface. The termination of a material with a surface leads to a change of the electronic band structure from the bulk material to the vacuum | https://huggingface.co/datasets/fmars/wiki_stem |
Surface stress was first defined by Josiah Willard Gibbs (1839-1903) as the amount of the reversible work per unit area needed to elastically stretch a pre-existing surface. A suggestion is surface stress define as association with the amount of the reversible work per unit area needed to elastically stretch a pre-existing surface instead of up definition. A similar term called "surface free energy", which represents the excess free energy per unit area needed to create a new surface, is easily confused with "surface stress" | https://huggingface.co/datasets/fmars/wiki_stem |
Syntactic foams are composite materials synthesized by filling a metal, polymer, cementitious or ceramic matrix with hollow spheres called microballoons or cenospheres or non-hollow spheres (e. g. perlite) as aggregates | https://huggingface.co/datasets/fmars/wiki_stem |
In mineralogy, tenacity is a mineral's behavior when deformed or broken.
Common terms
Brittleness:
The mineral breaks or powders easily. Most ionic-bonded minerals are brittle | https://huggingface.co/datasets/fmars/wiki_stem |
Terahertz nondestructive evaluation pertains to devices, and techniques of analysis occurring in the terahertz domain of electromagnetic radiation. These devices and techniques evaluate the properties of a material, component or system without causing damage.
Terahertz imaging
Terahertz imaging is an emerging and significant nondestructive evaluation (NDE) technique used for dielectric (nonconducting, i | https://huggingface.co/datasets/fmars/wiki_stem |
Welding of advanced thermoplastic composites is a beneficial method of joining these materials compared to mechanical fastening and adhesive bonding. Mechanical fastening requires intense labor, and creates stress concentrations, while adhesive bonding requires extensive surface preparation, and long curing cycles. Welding these materials is a cost-effective method of joining concerning preparation and execution, and these materials retain their properties upon cooling, so no post processing is necessary | https://huggingface.co/datasets/fmars/wiki_stem |
In physical chemistry and materials science, texture is the distribution of crystallographic orientations of a polycrystalline sample (it is also part of the geological fabric). A sample in which these orientations are fully random is said to have no distinct texture. If the crystallographic orientations are not random, but have some preferred orientation, then the sample has a weak, moderate or strong texture | https://huggingface.co/datasets/fmars/wiki_stem |
A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air. Fins attached to the core tubes serve to increase surface area for heat transfer to air that is forced past them by a fan, thereby heating the passenger compartment | https://huggingface.co/datasets/fmars/wiki_stem |
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