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Topic Review
Applications of polydimethylsiloxane (PDMS) in Engineering
Polydimethylsiloxane (PDMS) is an elastomer with excellent optical, electrical and mechanical properties, which makes it well-suited for several engineering applications. Due to its biocompatibility, PDMS is widely used for biomedical purposes. Some properties can be improved by adding additives.
  • 10.6K
  • 12 Jan 2022
Topic Review
Occupational Stress
Occupational stress is psychological stress related to one's job. Occupational stress refers to a chronic condition. Occupational stress can be managed by understanding what the stressful conditions at work are and taking steps to remediate those conditions. Occupational stress can occur when workers do not feel supported by supervisors or coworkers, feel as if they have little control over the work they perform, or find that their efforts on the job are incommensurate with the job's rewards. Occupational stress is a concern for both employees and employers because stressful job conditions are related to employees' emotional well-being, physical health, and job performance. A landmark study conducted by the World Health Organization and the International Labour Organization found that exposure to long working hours, which are theorized to operate through increased psycho-social occupational stress, is the occupational risk factor with the largest attributable burden of disease, according to these official estimates causing an estimated 745,000 workers to die from ischemic heart disease and stroke events in 2016. A number of disciplines within psychology are concerned with occupational stress including occupational health psychology, human factors and ergonomics, epidemiology, occupational medicine, sociology, industrial and organizational psychology, and industrial engineering.
  • 10.6K
  • 30 Sep 2022
Topic Review
Antenna Gain
In electromagnetics, an antenna's power gain or simply gain is a key performance number which combines the antenna's directivity and electrical efficiency. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. In a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power. When no direction is specified, gain is understood to refer to the peak value of the gain, the gain in the direction of the antenna's main lobe. A plot of the gain as a function of direction is called the gain pattern or radiation pattern. Antenna gain is usually defined as the ratio of the power produced by the antenna from a far-field source on the antenna's beam axis to the power produced by a hypothetical lossless isotropic antenna, which is equally sensitive to signals from all directions. Usually this ratio is expressed in decibels, and these units are referred to as decibels-isotropic (dBi). An alternative definition compares the received power to the power received by a lossless half-wave dipole antenna, in which case the units are written as dBd. Since a lossless dipole antenna has a gain of 2.15 dBi, the relation between these units is [math]\displaystyle{ \mathrm{Gain(dBd)} = \mathrm{Gain(dBi)} - 2.15 }[/math]. For a given frequency, the antenna's effective area is proportional to the power gain. An antenna's effective length is proportional to the square root of the antenna's gain for a particular frequency and radiation resistance. Due to reciprocity, the gain of any reciprocal antenna when receiving is equal to its gain when transmitting. Directive gain or directivity is a different measure which does not take an antenna's electrical efficiency into account. This term is sometimes more relevant in the case of a receiving antenna where one is concerned mainly with the ability of an antenna to receive signals from one direction while rejecting interfering signals coming from a different direction.
  • 10.6K
  • 10 Oct 2022
Topic Review
Digital Protective Relay
In utility and industrial electric power transmission and distribution systems, a digital protective relay is a computer-based system with software-based protection algorithms for the detection of electrical faults. Such relays are also termed as microprocessor type protective relays. They are functional replacements for electro-mechanical protective relays and may include many protection functions in one unit, as well as providing metering, communication, and self-test functions.
  • 10.6K
  • 09 Oct 2022
Topic Review
Social Construct Theory of ADHD
The social construction theory of ADHD argues that attention deficit hyperactivity disorder is not necessarily an actual pathology, but that an ADHD diagnosis is a socially constructed explanation to describe behaviors that simply do not meet prescribed social norms. Some proponents of the social construct theory of ADHD seem to regard the disorder as genuine, though over-diagnosed in some cultures. These proponents cite as evidence that the DSM IV, favored in the United States for defining and diagnosing mental illness, arrives at levels of ADHD three to four times higher than criteria in the ICD 10, the diagnostic guide favored by the World Health Organization. A popular proponent of this theory, Thomas Szasz, has argued that ADHD was "invented and not discovered."
  • 10.6K
  • 22 Nov 2022
Topic Review
Shenyang J-31
The Shenyang J-31 (or "FC-31 fifth Generation Multi-Purpose light Fighter") also known as the "Gyrfalcon" (鹘鹰), or "Falcon Hawk" by some military enthusiasts, is a twin-engine, mid-size fifth-generation jet fighter currently under development by Shenyang Aircraft Corporation. The fighter has also been referred to as the "F-60" or "J-21 Snowy Owl" (雪鸮) in some media reports. Its official name is Shenyang FC-31; J-xx nomenclatures in the Chinese military are reserved to programs launched and financed by the army, while this plane was developed by a state-owned company.
  • 10.6K
  • 10 Nov 2022
Topic Review
Offshore Wind Turbine Technology
Offshore wind turbines are becoming increasingly popular due to their higher wind energy harnessing capabilities and lower visual pollution. Structural integrity of offshore wind turbine and their blades’ aerodynamics are of particular importance, which can lead towards system-level optimal design and operation, leading to reduced maintenance costs. 
  • 10.6K
  • 20 Jan 2022
Topic Review
SLC35B1 is AXER
To fulfil its role in protein biogenesis, the endoplasmic reticulum (ER) depends on the Hsp70 chaperone BiP that requires a constant ATP-supply. While the original biochemical approaches established hallmarks of the ATP transport into the ER, such as nucleotide selectivity, affinity, and antiport mode, the more recent live-cell imaging methods employing sensitive, localized molecular probes identified the low abundant ATP/ADP exchanger in the membrane of the human ER. Our screen of gene expression datasets for member(s) of the family of solute carriers that are co-expressed with BiP and are ER membrane proteins identified SLC35B1 as a potential candidate. Heterologous expression of SLC35B1 in E. coli revealed that SLC35B1 is highly specific for ATP and ADP and acts in antiport mode, two of four characteristics it shared with the ATP transport activity, which is present in rough ER membranes. Moreover, depletion of SLC35B1 from HeLa cells reduced ER ATP levels and, therefore, BiP activity, which implied that SLC35B1 mediates ATP uptake into the ER plus ADP release from the ER in vivo. Thus, human SLC35B1 provides ATP to the ER and was named ATP/ADP exchanger in the ER membrane or AXER. Furthermore, we characterized a regulatory circuit that is able to maintain the ATP supply in the ER ad hoc and was termed ER low energy response or lowER. Recent work by others confirmed the role and mode of action of AXER and also suggested a possible scenario for long term adjustments (termed CaATiER). Most recently, the structure of AXER was solved and allowed the deduction of its molecular mechanism. Thus, the dust has settled on the discovery of AXER.
  • 10.6K
  • 08 Sep 2025
Biography
Theodor Schwann
Theodor Schwann ([1][2] 7 December 1810 – 11 January 1882) was a Germany physician and physiologist.[3] His most significant contribution to biology is considered to be the extension of cell theory to animals. Other contributions include the discovery of Schwann cells in the peripheral nervous system, the discovery and study of pepsin, the discovery of the organic nature of yeast,[4] and the i
  • 10.6K
  • 18 Nov 2022
Topic Review
Demonic Possession
Demonic possession is the belief that a person's actions are controlled by an alien spirit, demon, or entity. Symptoms of demonic possession commonly claimed by victims include missing memories, perceptual distortions, loss of a sense of control, and hyper-suggestibility. Erika Bourguignon found in a study of 488 societies worldwide, seventy-four percent believe in possession by spirits, with the highest numbers of beliefs in Pacific cultures and the lowest incidence among Native Americans of both North and South America.
  • 10.6K
  • 25 Nov 2022
Topic Review
Probability Sampling and Non Probability Sampling
There are two types of sampling methods namely: probability sampling and non-probability sampling. Each of these methods includes different types of techniques of sampling. Non-probability Sampling includes Quota sampling, Snowball sampling, Judgment sampling, and Convenience sampling, furthermore,  Probability Sampling includes Simple random, Stratified random, Cluster sampling, Systematic sampling and Multi stage sampling. 
  • 10.6K
  • 18 Feb 2022
Topic Review
The Transition to Adulthood
The transition to adulthood is a process that brings childhood to an end and turns the individual into a young adult. This process is characterised by the acquisition of new roles for young people, roles linked to the development of personal autonomy that culminate in their emotional and functional independence.
  • 10.5K
  • 31 Aug 2021
Topic Review
HMG-CoA-Reductase
3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) is an enzyme involved in the biosynthesis of cholesterol and an important target in the treatment of hypercholesterolemia.
  • 10.5K
  • 29 Oct 2020
Topic Review
Venus in Culture
Venus, as one of the brightest objects in the sky, has been known since prehistoric times and has been a major fixture in human culture for as long as records have existed. As such, it has a prominent position in human culture, religion, and myth. It has been made sacred to gods of many cultures, and has been a prime inspiration for writers and poets as the morning star and evening star.
  • 10.5K
  • 14 Nov 2022
Topic Review
Coffee By-Products
The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as animal feed.
  • 10.5K
  • 02 Nov 2020
Topic Review
Smart Textile Materials
In the last three decades, the development of new kinds of textiles, so-called smart and interactive textiles, has continued unabated. Smart textile materials and their applications are set to drastically boom as the demand for these textiles have been increasing with the emergence of new fibers, new fabrics, and innovative processing technologies. Moreover, people are eagerly demanding washable, flexible, lightweight, and robust e-textiles. These features depend on the properties of the starting material, the post-treatment, and the integration techniques. In this work, a comprehensive review has been conducted on the integration techniques of conductive materials in and onto a textile structure. The review showed that an e-textile can be developed by applying a conductive component on the surface of a textile substrate via plating, printing, coating, and other surface techniques, or by producing a textile substrate from metals and inherently conductive polymers via the creation of fibers and construction of yarns and fabrics with these. In addition, conductive filament fibers or yarns can be also integrated into conventional textile substrates during the fabrication like braiding, weaving, and knitting or as a post-fabrication of the textile fabric via embroidering. Additionally, layer-by-layer 3D printing of the entire smart textile components is possible, and the concept of 4D could play a significant role in advancing the status of smart textiles to a new level.
  • 10.5K
  • 29 Sep 2021
Biography
Irving Langmuir
Irving Langmuir (1881–1957) was an American chemist and physicist whose groundbreaking work laid the foundation for modern surface science and membrane biophysics. He earned his undergraduate degree in metallurgical engineering from the Columbia University School of Mines and later obtained his doctorate from the University of Göttingen, Germany, under the mentorship of Walther Nernst (Perutz
  • 10.5K
  • 03 Sep 2025
Topic Review
Chalk
Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). Chalk, as seen in Cretaceous deposits of Western Europe, is unusual among sedimentary limestones in the thickness of the beds. Most cliffs of chalk have very few obvious bedding planes unlike most thick sequences of limestone such as the Carboniferous Limestone or the Jurassic oolitic limestones. This may indicate very stable conditions over tens of millions of years. Chalk has greater resistance to weathering and slumping than the clays with which it is usually associated, thus forming tall, steep cliffs where chalk ridges meet the sea. Chalk hills, known as chalk downland, usually form where bands of chalk reach the surface at an angle, so forming a scarp slope. Because chalk is well jointed it can hold a large volume of ground water, providing a natural reservoir that releases water slowly through dry seasons.
  • 10.5K
  • 29 Nov 2022
Topic Review
Pinophyta
The Pinophyta, also known as Coniferophyta or Coniferae, or commonly as conifers, are a division of vascular land plants containing a single extant class, Pinopsida. They are gymnosperms, cone-bearing seed plants. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the immense conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of great economic value for softwood lumber and paper production.
  • 10.5K
  • 21 Oct 2022
Topic Review
Psychological Effects of Method Acting
Method acting is employed by actors to evoke realistic emotions into their performance by drawing on personal experiences. Raymond Hamden, doctor of Clinical and Forensic Psychology, defines the purpose of method acting as “compartmentalizing their own feelings while playing another character [so] they could bring the emotions of that personal feeling to cry if they needed to with that character.” However, when these emotions are not compartmentalized, they can encroach on other facets of life, often seeming to disrupt the actor’s psyche. This occurs as the actor delves into previous emotional experiences, be they joyful or traumatic. The psychological effects, like emotional fatigue, comes when suppressed or unresolved raw emotions are unburied to add to the character, not just from the employing personal emotions in performance. The question becomes whether the actor calls up resolved or unresolved emotions in their acting.
  • 10.5K
  • 16 Nov 2022
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