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Blood-spinning is a medical procedure used to shorten the healing time of an injury. Small samples of the patient's blood are taken and spun in a centrifuge, allowing platelets and blood plasma to be isolated from other blood components. The platelets and plasma are then combined forming platelet-rich plasma (PRP), which has high concentrations of natural growth factors | https://huggingface.co/datasets/fmars/wiki_stem |
Boosting is a method of inducing autonomic dysreflexia with the intention of enhancing performance in sport. It can be used by an athlete with a spinal cord injury to increase their blood pressure and is performed by causing a painful stimulus in the lower part of the body. The International Paralympic Committee (IPC) banned the practice in 1994, but many competitors with spinal injuries are still thought to be using it as a performance enhancer | https://huggingface.co/datasets/fmars/wiki_stem |
Caffeine use for sport is a worldwide known and tested idea. Many athletes use caffeine as a legal performance enhancer, as the benefits it provides, both physically and cognitively outweigh the disadvantages. The benefits caffeine provides influences the performance of both endurance athletes and anaerobic athletes | https://huggingface.co/datasets/fmars/wiki_stem |
The use of cannabis by athletes has been banned by many sports commissions. However, some have relaxed their policies as societal attitudes towards its use have shifted. The prohibition "is one of the most controversial issues in anti-doping" | https://huggingface.co/datasets/fmars/wiki_stem |
Some racing drivers have used doping in auto racing to enhance their performance. Deemed unsafe and illegal by the Fédération Internationale de l'Automobile. Appendix A to the International Sporting Code determines which substances are banned and mandates penalties | https://huggingface.co/datasets/fmars/wiki_stem |
The practice of doping in tennis involves the use of prohibited, performance-enhancing substances listed by the International Tennis Federation (ITF) and World Anti-Doping Agency (WADA). The practice is considered unsportsmanlike and unethical, with punishments for such offences ranging from official warnings to career bans, depending on the severity of the offence. Widespread illegal substance abuse in tennis developed during the 1980s and 1990s as performance-enhancing substances became increasingly available in professional sport | https://huggingface.co/datasets/fmars/wiki_stem |
A drug test is a technical analysis of a biological specimen, for example urine, hair, blood, breath, sweat, or oral fluid/saliva—to determine the presence or absence of specified parent drugs or their metabolites. Major applications of drug testing include detection of the presence of performance enhancing steroids in sport, employers and parole/probation officers screening for drugs prohibited by law (such as cocaine, methamphetamine, and heroin) and police officers testing for the presence and concentration of alcohol (ethanol) in the blood commonly referred to as BAC (blood alcohol content). BAC tests are typically administered via a breathalyzer while urinalysis is used for the vast majority of drug testing in sports and the workplace | https://huggingface.co/datasets/fmars/wiki_stem |
The Enhanced Games is a planned international sports event where the athletes will not be subject to drug testing. It is meant to take place in December 2024.
Content
The Enhanced Games was announced in June 2023, is intended to be annual and to include track and field, swimming, weightlifting, gymnastics and combat sports | https://huggingface.co/datasets/fmars/wiki_stem |
Gene doping is the hypothetical non-therapeutic use of gene therapy by athletes in order to improve their performance in those sporting events which prohibit such applications of genetic modification technology, and for reasons other than the treatment of disease. As of April 2015, there is no evidence that gene doping has been used for athletic performance-enhancement in any sporting events. Gene doping would involve the use of gene transfer to increase or decrease gene expression and protein biosynthesis of a specific human protein; this could be done by directly injecting the gene carrier into the person, or by taking cells from the person, transfecting the cells, and administering the cells back to the person | https://huggingface.co/datasets/fmars/wiki_stem |
The International Charter of Physical Education, Physical Activity and Sport is a rights-based document which was adopted by member states of the United Nations Educational, Scientific and Cultural Organization (UNESCO), on 18 November 2015 during the 38th session of the UNESCO General Conference. This document is the legitimate successor of the International Charter of Physical Education and Sport, originally adopted in 1978, during the 20th General Conference of UNESCO.
The original Charter, which was amended in 1991, was the first rights-based document to state that "the practice of physical education and sport is a fundamental right for all" | https://huggingface.co/datasets/fmars/wiki_stem |
The International Convention Against Doping in Sport is a multilateral UNESCO treaty by which states agree to adopt national measures to prevent and eliminate drug doping in sport. The convention was adopted at the General Conference of UNESCO in Paris on 19 October 2005. It entered into force on 1 February 2007 after it had been ratified by 30 state parties | https://huggingface.co/datasets/fmars/wiki_stem |
L. A. Confidentiel: Les secrets de Lance Armstrong (L | https://huggingface.co/datasets/fmars/wiki_stem |
Metandienone, also known as methandienone or methandrostenolone and sold under the brand name Dianabol (D-Bol) among others, is an androgen and anabolic steroid (AAS) medication which is still quite often used because of its affordability and effectiveness for bulking cycles. It is also used non-medically for physique- and performance-enhancing purposes. It is often taken by mouth | https://huggingface.co/datasets/fmars/wiki_stem |
Methyltestosterone, sold under the brand names Android, Metandren, and Testred among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, at low doses as a component of menopausal hormone therapy for menopausal symptoms like hot flashes, osteoporosis, and low sexual desire in women, and to treat breast cancer in women. It is taken by mouth or held in the cheek or under the tongue. Side effects of methyltestosterone include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire | https://huggingface.co/datasets/fmars/wiki_stem |
The NCAA's drug testing program exists to "protect players who play by the rules by playing clean. " The NCAA adopted its drug testing program in 1986, the year after the executive committee formed the Special NCAA Committee on Drug Testing. [1] The drug test ranges from testing player-enhancement drugs to marijuana | https://huggingface.co/datasets/fmars/wiki_stem |
"The Dark Side: Secrets of the Sports Dopers", investigating professional athletes' possible use of performance-enhancing substances, is an episode of Al Jazeera Investigates which was broadcast by Al Jazeera English and Al Jazeera America. The documentary identified Peyton Manning, Ryan Howard, Ryan Zimmerman, James Harrison, and Clay Matthews III.
Content
On December 27, 2015, Al Jazeera English and Al Jazeera America released a report conducted by the Al Jazeera Investigative Unit called The Dark Side: Secrets of the Sports Dopers which investigated professional athletes' potential use of Performance-enhancing drugs (PEDs) naming several prominent athletes as having received drugs from Charles Sly, a pharmacist who had worked at the Guyer Anti-Aging Clinic in Indianapolis during the fall of 2011 | https://huggingface.co/datasets/fmars/wiki_stem |
The World Drug-Free Powerlifting Federation (WDFPF) is an international powerlifting federation, founded in 1988, with 22 member countries. Its current president is Wim Backelant.
The federation is created specifically as a drug-free alternative international platform in order to provide fair competition world-wide for those powerlifters who wish to train and compete without performance-enhancing drugs | https://huggingface.co/datasets/fmars/wiki_stem |
7-Ketodehydroepiandrosterone (7-keto-DHEA,7-oxo-DHEA), also known as 7-oxoprasterone, is a prohormone produced by metabolism of the prohormone dehydroepiandrosterone (DHEA). 7-oxo-DHEA is even more effective than DHEA for inducing heat production (thermogenesis). Because dieting is usually accompanied by reduced resting metabolic rate, obese persons may benefit from using 7-oxo-DHEA when dieting due to increased metabolic rate | https://huggingface.co/datasets/fmars/wiki_stem |
Acetazolamide, sold under the trade name Diamox among others, is a medication used to treat glaucoma, epilepsy, altitude sickness, periodic paralysis, idiopathic intracranial hypertension (raised brain pressure of unclear cause), heart failure and to alkalinize urine. It may be used long term for the treatment of open angle glaucoma and short term for acute angle closure glaucoma until surgery can be carried out. It is taken by mouth or injection into a vein | https://huggingface.co/datasets/fmars/wiki_stem |
Adderall and Mydayis are trade names for a combination drug called mixed amphetamine salts containing four salts of amphetamine. The mixture is composed of equal parts racemic amphetamine and dextroamphetamine, which produces a (3:1) ratio between dextroamphetamine and levoamphetamine, the two enantiomers of amphetamine. Both enantiomers are stimulants, but differ enough to give Adderall an effects profile distinct from those of racemic amphetamine or dextroamphetamine, which are marketed as Evekeo and Dexedrine/Zenzedi, respectively | https://huggingface.co/datasets/fmars/wiki_stem |
Transparent wood composites are novel wood materials which have up to 90% transparency. Some have better mechanical properties than wood itself. They were made for the first time in 1992 | https://huggingface.co/datasets/fmars/wiki_stem |
Whenever two objects rub together, for instance wheels on a road, gears in a motor, there is both friction and wear. Different surfaces have different amounts of friction, for instance a smooth surface compared to a rough one. How much material comes off also depends upon the surfaces, and also how much pressure is used -- for instance using sandpaper to smooth out wood | https://huggingface.co/datasets/fmars/wiki_stem |
Ultimate tensile strength (also called UTS, tensile strength, TS, ultimate strength or
F
tu
{\displaystyle F_{\text{tu}}}
in notation) is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials the ultimate tensile strength is close to the yield point, whereas in ductile materials the ultimate tensile strength can be higher.
The ultimate tensile strength is usually found by performing a tensile test and recording the engineering stress versus strain | https://huggingface.co/datasets/fmars/wiki_stem |
A universal testing machine (UTM), also known as a universal tester, materials testing machine or materials test frame, is used to test the tensile strength and compressive strength of materials. An earlier name for a tensile testing machine is a tensometer. The "universal" part of the name reflects that it can perform many standard tensile and compression tests on materials, components, and structures (in other words, that it is versatile) | https://huggingface.co/datasets/fmars/wiki_stem |
The universality–diversity paradigm is the analysis of biological materials based on the universality and diversity of its fundamental structural elements and functional mechanisms. The analysis of biological systems based on this classification has been a cornerstone of modern biology.
For example, proteins constitute the elementary building blocks of a vast variety of biological materials such as cells, spider silk or bone, where they create extremely robust, multi-functional materials by self-organization of structures over many length- and time scales, from nano to macro | https://huggingface.co/datasets/fmars/wiki_stem |
Vapor polishing is a method of polishing plastics to reduce the surface roughness or improve clarity. Typically, a component is exposed to a chemical vapor causing the surface to flow thereby improving the surface finish. This method of polishing is frequently used to return clear materials to an optical quality finish after machining | https://huggingface.co/datasets/fmars/wiki_stem |
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 | https://huggingface.co/datasets/fmars/wiki_stem |
Volume solid is the volume of paint after it has dried. This is different than the weight solid. Paint may contain solvent, resin, pigments, and additives | https://huggingface.co/datasets/fmars/wiki_stem |
Waviness is the measurement of the more widely spaced component of surface texture. It is a broader view of roughness because it is more strictly defined as "the irregularities whose spacing is greater than the roughness sampling length". It can occur from machine or work deflections, chatter, residual stress, vibrations, or heat treatment | https://huggingface.co/datasets/fmars/wiki_stem |
The wear coefficient is a physical coefficient used to measure, characterize and correlate the wear of materials.
Background
Traditionally, the wear of materials has been characterized by weight loss and wear rate. However, studies have found that wear coefficient is more suitable | https://huggingface.co/datasets/fmars/wiki_stem |
Advanced thermoplastic composites (ACM) have a high strength fibres held together by a thermoplastic matrix. Advanced thermoplastic composites are becoming more widely used in the aerospace, marine, automotive and energy industry. This is due to the decreasing cost and superior strength to weight ratios, over metallic parts | https://huggingface.co/datasets/fmars/wiki_stem |
Wideband material refers to material that can convey Microwave signals (light/sound) over a variety of wavelengths. These materials possess exemplary attenuation and dielectric constants, and are excellent dielectrics for semiconductor gates. Examples of such material include gallium nitride (GaN) and silicon carbide (SiC) | https://huggingface.co/datasets/fmars/wiki_stem |
A Wilhelmy plate is a thin plate that is used to measure equilibrium surface or interfacial tension at an air–liquid or liquid–liquid interface. In this method, the plate is oriented perpendicular to the interface, and the force exerted on it is measured. Based on the work of Ludwig Wilhelmy, this method finds wide use in the preparation and monitoring of Langmuir films | https://huggingface.co/datasets/fmars/wiki_stem |
X-ray absorption spectroscopy (XAS) is a widely used technique for determining the local geometric and/or electronic structure of matter. The experiment is usually performed at synchrotron radiation facilities, which provide intense and tunable X-ray beams. Samples can be in the gas phase, solutions, or solids | https://huggingface.co/datasets/fmars/wiki_stem |
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information | https://huggingface.co/datasets/fmars/wiki_stem |
X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystal structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.
Note that X-ray diffraction is now often considered a sub-set of X-ray scattering, where the scattering is elastic and the scattering object is crystalline, so that the resulting pattern contains sharp spots analyzed by X-ray crystallography (as in the Figure) | https://huggingface.co/datasets/fmars/wiki_stem |
In materials science, the yield strength anomaly refers to materials wherein the yield strength (i. e. , the stress necessary to initiate plastic yielding) increases with temperature | https://huggingface.co/datasets/fmars/wiki_stem |
A yield surface is a five-dimensional surface in the six-dimensional space of stresses. The yield surface is usually convex and the state of stress of inside the yield surface is elastic. When the stress state lies on the surface the material is said to have reached its yield point and the material is said to have become plastic | https://huggingface.co/datasets/fmars/wiki_stem |
The Z-tube is an experimental apparatus for measuring the tensile strength of a liquid.
It consists of a Z-shaped tube with open ends, filled with a liquid, and set on top of a spinning table. If the tube were straight, the liquid would immediately fly out one end or the other of the tube as it began to spin | https://huggingface.co/datasets/fmars/wiki_stem |
Zener pinning is the influence of a dispersion of fine particles on the movement of low- and high-angle grain boundaries through a polycrystalline material. Small particles act to prevent the motion of such boundaries by exerting a pinning pressure which counteracts the driving force pushing the boundaries. Zener pinning is very important in materials processing as it has a strong influence on recovery, recrystallization and grain growth | https://huggingface.co/datasets/fmars/wiki_stem |
Zero-point energy (ZPE) is the lowest possible energy that a quantum mechanical system may have. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state as described by the Heisenberg uncertainty principle. Therefore, even at absolute zero, atoms and molecules retain some vibrational motion | https://huggingface.co/datasets/fmars/wiki_stem |
The Zinagizado is an electrochemical process to provide a ferrous metal material with anti-corrosive properties. It involves the application of a constant electric current through a circuit to break the bonds and these are attached to the metal to be coated by forming a surface coating. The alloy used is called Zinag (Zn-Al-Ag); this alloy has excellent mechanical and corrosive properties, so the piece will have increased by 60% of life | https://huggingface.co/datasets/fmars/wiki_stem |
Zone axis, a term sometimes used to refer to "high-symmetry" orientations in a crystal, most generally refers to any direction referenced to the direct lattice (as distinct from the reciprocal lattice) of a crystal in three dimensions. It is therefore indexed with direct lattice indices, instead of with Miller indices.
High-symmetry zone axes through a crystal lattice, in particular, often lie in the direction of tunnels through the crystal between planes of atoms | https://huggingface.co/datasets/fmars/wiki_stem |
The adaptive machine is a category of flexible industrial machinery characterized by the ability to intelligently adapt itself to the product to be produced, e. g. to move individual products through the manufacturing, assembly, inspection, packaging and other process stations required for to produce them | https://huggingface.co/datasets/fmars/wiki_stem |
An agitator is a device or mechanism to put something into motion by shaking or stirring. There are several types of agitation machines, including washing machine agitators (which rotate back and forth) and magnetic agitators (which contain a magnetic bar rotating in a magnetic field). Agitators can come in many sizes and varieties, depending on the application | https://huggingface.co/datasets/fmars/wiki_stem |
An air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. An air handler is usually a large metal box containing a blower, furnace or A/C elements, filter racks or chambers, sound attenuators, and dampers. Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU | https://huggingface.co/datasets/fmars/wiki_stem |
An air preheater is any device designed to heat air before another process (for example, combustion in a boiler With the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a recuperative heat system or to replace a steam coil.
In particular, this article describes the combustion air preheaters used in large boilers found in thermal power stations producing electric power from e | https://huggingface.co/datasets/fmars/wiki_stem |
Airflow, or air flow, is the movement of air. The primary cause of airflow is the existence of air. Air behaves in a fluid manner, meaning particles naturally flow from areas of higher pressure to those where the pressure is lower | https://huggingface.co/datasets/fmars/wiki_stem |
In manufacturing, an airshaft is a device used for handling winding reels in the processing of web-fed materials, such as continuous-process printing presses. Airshafts—also called Air Expanding shafts—are used in the manufacturing processes for fitting into a core onto which materials such as paper, card and plastic film are wound. An airshaft is designed so that, on fitting into a core, it can be readily expanded, thereby achieving a quick and firm attachment, it may also be easily deflated to facilitate easy withdrawal of the shaft after winding of product is complete | https://huggingface.co/datasets/fmars/wiki_stem |
An automaton clock or automata clock is a type of striking clock featuring automatons. Clocks like these were built from the 1st century BC through to Victorian times in Europe. A Cuckoo clock is a simple form of this type of clock | https://huggingface.co/datasets/fmars/wiki_stem |
An axial fan is a type of fan that causes gas to flow through it in an axial direction, parallel to the shaft about which the blades rotate. The flow is axial at entry and exit. The fan is designed to produce a pressure difference, and hence force, to cause a flow through the fan | https://huggingface.co/datasets/fmars/wiki_stem |
A backdrive is a component used in reverse to obtain its input from its output. This extends to many concepts and systems from thought based to practical mechanical applications.
Not every system can be backdriven | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanical engineering, backlash, sometimes called lash, play, or slop, is a clearance or lost motion in a mechanism caused by gaps between the parts. It can be defined as "the maximum distance or angle through which any part of a mechanical system may be moved in one direction without applying appreciable force or motion to the next part in mechanical sequence. "p | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanical engineering, the Beale number is a parameter that characterizes the performance of Stirling engines. It is often used to estimate the power output of a Stirling engine design. For engines operating with a high temperature differential, typical values for the Beale number are in the range 0 | https://huggingface.co/datasets/fmars/wiki_stem |
Bearing pressure is a particular case of contact mechanics often occurring in cases where a convex surface (male cylinder or sphere) contacts a concave surface (female cylinder or sphere: bore or hemispherical cup). Excessive contact pressure can lead to a typical bearing failure such as a plastic deformation similar to peening. This problem is also referred to as bearing resistance | https://huggingface.co/datasets/fmars/wiki_stem |
A bearing surface in mechanical engineering is the area of contact between two objects. It usually is used in reference to bolted joints and bearings, but can be applied to a wide variety of engineering applications. The choice of bearing surface depends on the application, load, speed, and operating conditions, and the design must be able to withstand high loads, resist wear and corrosion, and operate at high speeds | https://huggingface.co/datasets/fmars/wiki_stem |
A bellcrank is a type of crank that changes motion through an angle. The angle can be any angle from 0 to 360 degrees, but 90 degrees and 180 degrees are most common. The name comes from its first use, changing the vertical pull on a rope to a horizontal pull on the striker of a bell, used for calling staff in large houses or commercial establishments | https://huggingface.co/datasets/fmars/wiki_stem |
A Block and bleed manifold is a hydraulic manifold that combines one or more block/isolate valves, usually ball valves, and one or more bleed/vent valves, usually ball or needle valves, into one component for interface with other components (pressure measurement transmitters, gauges, switches, etc. ) of a hydraulic (fluid) system. The purpose of the block and bleed manifold is to isolate or block the flow of fluid in the system so the fluid from upstream of the manifold does not reach other components of the system that are downstream | https://huggingface.co/datasets/fmars/wiki_stem |
A bolt circle diameter or pitch circle diameter (PCD), sometimes simply called bolt circle or pitch circle, is a common term for when a number of screw holes for bolts are evenly distributed with their centers along an imaginary circle with a given diameter.
An example of use is mounting of car rims, where the bolt circle is one of several factors that determine whether a set of rims will fit a car. For example, a bolt circle of 5×130 or 5-130 indicates that a rim is to be attached to the car via 5 screws evenly spaced along a circle with a diameter of 130 millimeters | https://huggingface.co/datasets/fmars/wiki_stem |
A bolted joint is one of the most common elements in construction and machine design. It consists of a male threaded fastener (e. g | https://huggingface.co/datasets/fmars/wiki_stem |
A bond graph is a graphical representation of a physical dynamic system. It allows the conversion of the system into a state-space representation. It is similar to a block diagram or signal-flow graph, with the major difference that the arcs in bond graphs represent bi-directional exchange of physical energy, while those in block diagrams and signal-flow graphs represent uni-directional flow of information | https://huggingface.co/datasets/fmars/wiki_stem |
Break-in or breaking in, also known as run-in or running in, is the procedure of conditioning a new piece of equipment by giving it an initial period of running, usually under light load, but sometimes under heavy load or normal load. It is generally a process of moving parts wearing against each other to produce the last small bit of size and shape adjustment that will settle them into a stable relationship for the rest of their working life.
One of the most common examples of break-in is engine break-in for petrol engines and diesel engines | https://huggingface.co/datasets/fmars/wiki_stem |
Brinelling is the permanent indentation of a hard surface. It is named after the Brinell scale of hardness, in which a small ball is pushed against a hard surface at a preset level of force, and the depth and diameter of the mark indicates the Brinell hardness of the surface. Brinelling is permanent plastic deformation of a surface, and usually occurs while two surfaces in contact are stationary (such as rolling elements and the raceway of a bearings) and the material yield strength has been exceeded | https://huggingface.co/datasets/fmars/wiki_stem |
A built-up gun is artillery with a specially reinforced barrel. An inner tube of metal stretches within its elastic limit under the pressure of confined powder gases to transmit stress to outer cylinders that are under tension. Concentric metal cylinders or wire windings are assembled to minimize the weight required to resist the pressure of powder gases pushing a projectile out of the barrel | https://huggingface.co/datasets/fmars/wiki_stem |
A bullwheel or bull wheel is a large wheel on which a rope turns, such as in a chairlift or other ropeway. In this application, the bullwheel that is attached to the prime mover is called the drive bullwheel, and the other is the return bullwheel. One of the bullwheels is usually attached to a cable tensioning system, which is usually either hydraulic or fixed counterweights | https://huggingface.co/datasets/fmars/wiki_stem |
Burnishing is the plastic deformation of a surface due to sliding contact with another object. It smooths the surface and makes it shinier. Burnishing may occur on any sliding surface if the contact stress locally exceeds the yield strength of the material | https://huggingface.co/datasets/fmars/wiki_stem |
A bushing or rubber bushing is a type of vibration isolator. It provides an interface between two parts, damping the energy transmitted through the bushing. A common application is in vehicle suspension systems, where a bushing made of rubber (or, more often, synthetic rubber or polyurethane) separates the faces of two metal objects while allowing a certain amount of movement | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanical engineering, a cam follower, also known as a track follower, is a specialized type of roller or needle bearing designed to follow cam lobe profiles. Cam followers come in a vast array of different configurations, however the most defining characteristic is how the cam follower mounts to its mating part; stud style cam followers use a stud while the yoke style has a hole through the middle.
Construction
The modern stud type follower was invented and patented in 1937 by Thomas L | https://huggingface.co/datasets/fmars/wiki_stem |
The cam plastometer is a physical testing machine. It measures the resistance of non-brittle materials to compressive deformation at constant true-strain rates. In this way, it can be compared a bit to the Gleeble® | https://huggingface.co/datasets/fmars/wiki_stem |
A centrifugal pendulum absorber is a type of tuned mass damper. It reduces the amplitude of a torsional vibration in drive trains that use a combustion engine.
History
The centrifugal pendulum absorber was first patented in 1937 by R | https://huggingface.co/datasets/fmars/wiki_stem |
Chilled water is a commodity often used to cool a building's air and equipment, especially in situations where many individual rooms must be controlled separately, such as a hotel. The chilled water can be supplied by a vendor, such as a public utility, or created at the location of the building that will use it, which has been the norm.
Use
Chilled water cooling is not very different from typical residential air conditioning where water is pumped from the chiller to the air handler unit to cool the air | https://huggingface.co/datasets/fmars/wiki_stem |
A chiller is a machine that removes heat from a liquid coolant via a vapor-compression, adsorption refrigeration, or absorption refrigeration cycles. This liquid can then be circulated through a heat exchanger to cool equipment, or another process stream (such as air or process water). As a necessary by-product, refrigeration creates waste heat that must be exhausted to ambience, or for greater efficiency, recovered for heating purposes | https://huggingface.co/datasets/fmars/wiki_stem |
Circle grid analysis (CGA), also known as circle grid strain analysis, is a method of measuring the strain levels of sheet metal after a part is formed by stamping or drawing. The name itself is a fairly accurate description of the process. Literally, a grid of circles of known diameter is etched to the surface of the sheet metal to be formed | https://huggingface.co/datasets/fmars/wiki_stem |
A circulating water plant or circulating water system is an arrangement of flow of water in fossil-fuel power station, chemical plants and in oil refineries. The system is required because various industrial process plants uses heat exchanger, and also for active fire protection measures. In chemical plants, for example in caustic soda production, water is needed in bulk quantity for preparation of brine | https://huggingface.co/datasets/fmars/wiki_stem |
A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turbine (CCGT) plant. The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant | https://huggingface.co/datasets/fmars/wiki_stem |
The compound lever is a simple machine operating on the premise that the resistance from one lever in a system of levers acts as effort for the next, and thus the applied force is transferred from one lever to the next. Almost all scales use some sort of compound lever to work. Other examples include nail clippers and piano keys | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanics, compression is the application of balanced inward ("pushing") forces to different points on a material or structure, that is, forces with no net sum or torque directed so as to reduce its size in one or more directions. It is contrasted with tension or traction, the application of balanced outward ("pulling") forces; and with shearing forces, directed so as to displace layers of the material parallel to each other. The compressive strength of materials and structures is an important engineering consideration | https://huggingface.co/datasets/fmars/wiki_stem |
Constant air volume (CAV) is a type of heating, ventilating, and air-conditioning (HVAC) system. In a simple CAV system, the supply air flow rate is constant, but the supply air temperature is varied to meet the thermal loads of a space. Most CAV systems are small, and serve a single thermal zone | https://huggingface.co/datasets/fmars/wiki_stem |
Constrained-layer damping is a mechanical engineering technique for suppression of vibration. Typically a viscoelastic or other damping material, is sandwiched between two sheets of stiff materials that lack sufficient damping by themselves. The ending result is, any vibration made on either side of the constraining materials (the two stiffer materials on the sides) are trapped and evidently dissipated in the viscoelastic or middle layer | https://huggingface.co/datasets/fmars/wiki_stem |
Contact mechanics is the study of the deformation of solids that touch each other at one or more points. A central distinction in contact mechanics is between stresses acting perpendicular to the contacting bodies' surfaces (known as normal stress) and frictional stresses acting tangentially between the surfaces (shear stress). Normal contact mechanics or frictionless contact mechanics focuses on normal stresses caused by applied normal forces and by the adhesion present on surfaces in close contact, even if they are clean and dry | https://huggingface.co/datasets/fmars/wiki_stem |
Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls overlaps and is usually taught along with electrical engineering and mechanical engineering at many institutions around the world. The practice uses sensors and detectors to measure the output performance of the process being controlled; these measurements are used to provide corrective feedback helping to achieve the desired performance | https://huggingface.co/datasets/fmars/wiki_stem |
In solid mechanics, in the field of rotordynamics, the critical speed is the theoretical angular velocity that excites the natural frequency of a rotating object, such as a shaft, propeller, leadscrew, or gear. As the speed of rotation approaches the object's natural frequency, the object begins to resonate, which dramatically increases system vibration. The resulting resonance occurs regardless of orientation | https://huggingface.co/datasets/fmars/wiki_stem |
In geometry and topology, crumpling is the process whereby a sheet of paper or other two-dimensional manifold undergoes disordered deformation to yield a three-dimensional structure comprising a random network of ridges and facets with variable density. The geometry of crumpled structures is the subject of some interest to the mathematical community within the discipline of topology. Crumpled paper balls have been studied and found to exhibit surprisingly complex structures with compressive strength resulting from frictional interactions at locally flat facets between folds | https://huggingface.co/datasets/fmars/wiki_stem |
Cryogenic engineering is a sub stream of mechanical engineering dealing with cryogenics, and related very low temperature processes such as air liquefaction, cryogenic engines (for rocket propulsion), cryosurgery. Generally, temperatures below cold come under the purview of cryogenic engineering.
Cryogenics may be considered as the recent advancement in the field of refrigeration | https://huggingface.co/datasets/fmars/wiki_stem |
A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air-handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate control -- for example in the case of Volume Control Dampers. Its operation can be manual or automatic | https://huggingface.co/datasets/fmars/wiki_stem |
The deep hole drilling (DHD) measurement technique is a residual stress measurement technique used to measure locked-in and applied stresses in engineering materials and components. DHD is a semi-destructive mechanical strain relaxation (MSR) technique, which seeks to measure the distribution of stresses along the axis of a drilled reference hole. The process is unique in its ability to measure residual stresses at a microscopic level with a penetration of over 750 millimetres (30 in), without total destruction of the original component | https://huggingface.co/datasets/fmars/wiki_stem |
Design for manufacturability (also sometimes known as design for manufacturing or DFM) is the general engineering practice of designing products in such a way that they are easy to manufacture. The concept exists in almost all engineering disciplines, but the implementation differs widely depending on the manufacturing technology. DFM describes the process of designing or engineering a product in order to facilitate the manufacturing process in order to reduce its manufacturing costs | https://huggingface.co/datasets/fmars/wiki_stem |
The term Dexel has two common uses:
Dexel ("depth pixel") is a concept used for a discretized representation of functions defined on surfaces used in geometrical modeling and physical simulation, sometimes also referred to as multilevel Z-map. Dexel is a nodal value of a scalar or vector field on a meshed surface. Dexels are used in simulation of manufacturing processes (such as turning, milling or rapid prototyping), when workpiece surfaces are subject to modifications | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanical engineering, many terms are associated into pairs called duals. A dual of a relationship is formed by interchanging force (stress) and deformation (strain) in an expression.
Here is a partial list of mechanical dualities:
force — deformation
stress — strain
stiffness method — flexibility method
Examples
Constitutive relation
stress and strain (Hooke's law | https://huggingface.co/datasets/fmars/wiki_stem |
Dunkerley's method is used in mechanical engineering to determine the critical speed of a shaft-rotor system. Other methods include the Rayleigh–Ritz method.
Whirling of a shaft
No shaft can ever be perfectly straight or perfectly balanced | https://huggingface.co/datasets/fmars/wiki_stem |
A duty cycle or power cycle is the fraction of one period in which a signal or system is active. Duty cycle is commonly expressed as a percentage or a ratio. A period is the time it takes for a signal to complete an on-and-off cycle | https://huggingface.co/datasets/fmars/wiki_stem |
Elegant degradation is a term used in engineering to describe what occurs to machines which are subject to constant, repetitive stress.
Externally, such a machine maintains the same appearance to the user, appearing to function properly. Internally, the machine slowly weakens over time | https://huggingface.co/datasets/fmars/wiki_stem |
Embedment is a phenomenon in mechanical engineering in which the surfaces between mechanical members of a loaded joint embed. It can lead to failure by fatigue as described below, and is of particular concern when considering the design of critical fastener joints.
Mechanism
The mechanism behind embedment is different from creep | https://huggingface.co/datasets/fmars/wiki_stem |
The engineering design process, also known as the engineering method, is a common series of steps that engineers use in creating functional products and processes. The process is highly iterative - parts of the process often need to be repeated many times before another can be entered - though the part(s) that get iterated and the number of such cycles in any given project may vary.
It is a decision making process (often iterative) in which the basic sciences, mathematics, and engineering sciences are applied to convert resources optimally to meet a stated objective | https://huggingface.co/datasets/fmars/wiki_stem |
Engineering Equation Solver (EES) is a commercial software package used for solution of systems of simultaneous non-linear equations. It provides many useful specialized functions and equations for the solution of thermodynamics and heat transfer problems, making it a useful and widely used program for mechanical engineers working in these fields. EES stores thermodynamic properties, which eliminates iterative problem solving by hand through the use of code that calls properties at the specified thermodynamic properties | https://huggingface.co/datasets/fmars/wiki_stem |
Engineering fits are generally used as part of geometric dimensioning and tolerancing when a part or assembly is designed. In engineering terms, the "fit" is the clearance between two mating parts, and the size of this clearance determines whether the parts can, at one end of the spectrum, move or rotate independently from each other or, at the other end, are temporarily or permanently joined. Engineering fits are generally described as a "shaft and hole" pairing, but are not necessarily limited to just round components | https://huggingface.co/datasets/fmars/wiki_stem |
In mechanical engineering, an envelope is a solid representing all positions which may be occupied by an object during its normal range of motion.
Another (jargon) word for this is a "flop".
Wheel envelope
In automobile design, a wheel envelope may be used to model all positions a wheel and tire combo may be expected to occupy during driving | https://huggingface.co/datasets/fmars/wiki_stem |
In physics and chemistry, an equation of state is a thermodynamic equation relating state variables, which describe the state of matter under a given set of physical conditions, such as pressure, volume, temperature, or internal energy. Most modern equations of state are formulated in the Helmholtz free energy. Equations of state are useful in describing the properties of pure substances and mixtures in liquids, gases, and solid states as well as the state of matter in the interior of stars | https://huggingface.co/datasets/fmars/wiki_stem |
An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials. They are commonly found between sections of buildings, bridges, sidewalks, railway tracks, piping systems, ships, and other structures.
Building faces, concrete slabs, and pipelines expand and contract due to warming and cooling from seasonal variation, or due to other heat sources | https://huggingface.co/datasets/fmars/wiki_stem |
A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner | https://huggingface.co/datasets/fmars/wiki_stem |
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