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Topic Review
Potential Flow Around a Circular Cylinder
In mathematics, potential flow around a circular cylinder is a classical solution for the flow of an inviscid, incompressible fluid around a cylinder that is transverse to the flow. Far from the cylinder, the flow is unidirectional and uniform. The flow has no vorticity and thus the velocity field is irrotational and can be modeled as a potential flow. Unlike a real fluid, this solution indicates a net zero drag on the body, a result known as d'Alembert's paradox.
  • 5.9K
  • 31 Oct 2022
Topic Review
Livery
A livery /ˈlɪvəri/ is a uniform, insignia or symbol adorning, in a non-military context, a person, an object or a vehicle that denotes a relationship between the wearer of the livery and an individual or corporate body. Often, elements of the heraldry relating to the individual or corporate body feature in the livery. Alternatively, some kind of a personal emblem or badge, or a distinctive colour, is featured. The word itself derives from the French livrée, meaning dispensed, handed over. Most often it would indicate that the wearer of the livery was a servant, dependant, follower or friend of the owner of the livery, or, in the case of objects, that the object belonged to them. In the late medieval phenomenon of bastard feudalism, livery badges worn by the "retainers" of great lords, sometimes in effect private armies, became a great political concern in England.
  • 5.9K
  • 01 Dec 2022
Topic Review
Immunoformulation for COVID-19
The number of patients infected with the SARS-CoV-2 is still growing worldwide, with no current vaccine or medicinal treatment up to this date. Here we describe the cases of four COVID-19 patients that used a combination of therapeutic/nutraceutical agents for improvement of their symptoms. The ingredients were: immune transfer factor (oligo- and polypeptides fractions from porcine spleen, ultrafiltered at <10 kDa; Imuno TF®), anti-inflammatory natural blend (Uncaria tomentosa, Endopleura uchi and Haematoccocus pluvialis; Miodesin®), zinc, selenium, ascorbic acid, cholecalciferol, ferulic acid, spirulina, N-acetylcysteine, glucosamine sulfate potassium hydrochloride, trans-resveratrol, and maltodextrin-stabilized orthosilicic acid (SiliciuMax®). The four showed improvement in general symptoms after using the combination proposed here. The cases presented here are just a first hint towards its benefit (decreases time necessary for the recovery of the patients), this would be a good starting point to the further investigation of this possible add-on therapy in controlled clinical studies. Limited sample size and study design are limitations for definitive conclusions on the add-on therapy.
  • 5.9K
  • 05 Nov 2020
Topic Review
Dyes, Minerals, and Vitamins Used in Cosmetics
Most minerals and vitamins are beneficial when it comes to the improvement of the condition of the skin, hair or nails, and as they are mostly safe for use, they are valued raw materials and cosmetic ingredients. Dyes and pigments, due to the potential negative impact on human health of many of them, are often controversial components of cosmetic preparations. The constantly growing awareness of consumers makes cosmetics manufacturers strive to eliminate potentially harmful substances and use safe raw materials and ingredients of natural origin.
  • 5.9K
  • 23 Nov 2021
Topic Review
Arms Industry
The arms industry, also known as the defense industry or the arms trade, is a global industry responsible for the manufacturing and sales of weapons and military technology. It consists of a commercial industry involved in the research and development, engineering, production, and servicing of military material, equipment, and facilities. Arms-producing companies, also referred to as arms dealers, defence contractors, or as the military industry, produce arms for the armed forces of states and civilians. Departments of government also operate in the arms industry, buying and selling weapons, munitions and other military items. An arsenal is a place where arms and ammunition are made, maintained and repaired, stored, or issued, in any combination, whether privately or publicly owned. Products include guns, artillery, ammunition, missiles, military aircraft, military vehicles, ships, electronic systems, night vision devices, holographic weapon sights, laser rangefinders, laser sights, hand grenades, landmines and more. The arms industry also provides other logistical and operational support. Stockholm International Peace Research Institute (SIPRI) estimated that 2012 military expenditures were roughly $1.8 trillion. This represents a relative decline from 1990 when military expenditures made up 4% of world GDP. Part of the money goes to the procurement of military hardware and services from the military industry. The combined arms sales of the top 100 largest arms-producing companies amounted to an estimated $395 billion in 2012 according to SIPRI. In 2004 over $30 billion were spent in the international arms trade (a figure that excludes domestic sales of arms). According to SIPRI, the volume of international transfers of major weapons in 2010–14 was 16 per cent higher than in 2005–2009. The five biggest exporters in 2010–2014 were the United States, Russia, China, Germany and France, and the five biggest importers were India, Saudi Arabia, China, the United Arab Emirates and Pakistan. Many industrialized countries have a domestic arms-industry to supply their own military forces. Some countries also have a substantial legal or illegal domestic trade in weapons for use by its citizens, primarily for self-defence, hunting or sporting purposes. Illegal trade in small arms occurs in many countries and regions affected by political instability. The Small Arms Survey estimates that 875 million small arms circulate worldwide, produced by more than 1,000 companies from nearly 100 countries. Contracts to supply a given country's military are awarded by governments, making arms contracts of substantial political importance. The link between politics and the arms trade can result in the development of what U.S. President Dwight D. Eisenhower described as a military-industrial complex, where the armed forces, commerce, and politics become closely linked, similarly to the European multilateral defence procurement. Various corporations, some publicly held, others private, bid for these contracts, which are often worth many billions of dollars. Sometimes, as with the contract for the international Joint Strike Fighter, a competitive tendering process takes place, with the decision made on the merits of the designs submitted by the companies involved. Other times, no bidding or competition takes place.
  • 5.9K
  • 10 Dec 2025
Topic Review
Colorants in Water and Toxicity
Dyes (colorants) are used in many industrial applications, and have become vital to the industrial production infrastructure. However,  effluents of some dyeing industries contain toxic chemicals, which are detrimental to both the environment and human health. Therefore,  wastewater containing dyes must be properly treated before discharging to surrounding water bodies, and this paper summarises that the most effective current method of effluent treatment for dye industries is adsorption using Biochar.
  • 5.9K
  • 08 Feb 2021
Topic Review
Hepatocellular Carcinoma
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related morbidity and mortality worldwide. Most patients are diagnosed with advanced disease, limiting their options for treatment. While current treatments are adequate for lower staged disease, available systemic treatments are limited, with marginal benefit at best. The below section reviews the incidence, prevalence, healthcare associated cost, and etiologies of HCC. In addition, an overview of the classification, treatment algorithm, and treatment modalities are provided.
  • 5.9K
  • 07 Jan 2021
Topic Review
L-Carnitine in Mitochondria
Mitochondria control cellular fate by various mechanisms and are key drivers of cellular metabolism. Although the main function of mitochondria is energy production, they are also involved in cellular detoxification, cellular stabilization, as well as control of ketogenesis and glucogenesis. Conditions like neurodegenerative disease, insulin resistance, endocrine imbalances, liver and kidney disease are intimately linked to metabolic disorders or inflexibility and to mitochondrial dysfunction. Mitochondrial dysfunction due to a relative lack of micronutrients and substrates is implicated in the development of many chronic diseases. l-carnitine is a vital molecule that is found in all living cells. It is a quaternary amine (3-hydroxy-4-N-trimethylaminobutyrate) whose main function in mammalian cells is the transfer of long chain fatty acids across the inner mitochondrial membrane for β- oxidation and generation of ATP energy. 
  • 5.9K
  • 11 Mar 2022
Topic Review
Psychophysics
Psychophysics quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce. Psychophysics has been described as "the scientific study of the relation between stimulus and sensation" or, more completely, as "the analysis of perceptual processes by studying the effect on a subject's experience or behaviour of systematically varying the properties of a stimulus along one or more physical dimensions". Psychophysics also refers to a general class of methods that can be applied to study a perceptual system. Modern applications rely heavily on threshold measurement, ideal observer analysis, and signal detection theory. Psychophysics has widespread and important practical applications. For example, in the study of digital signal processing, psychophysics has informed the development of models and methods of lossy compression. These models explain why humans perceive very little loss of signal quality when audio and video signals are formatted using lossy compression.
  • 5.9K
  • 10 Nov 2022
Topic Review
Bioremediation Techniques
Bioremediation is a process that uses biological organisms to remove or re-treat an environmental pollutant through metabolic processes and plants to eradicate hazardous pollutants and restore the ecosystem to its original condition.
  • 5.9K
  • 24 Apr 2023
Topic Review
Authenticity in Art
Authenticity in art is the different ways in which a work of art or an artistic performance may be considered authentic. Denis Dutton distinguishes between nominal authenticity and expressive authenticity. The first refers to the correct identification of the author of a work of art, to how closely a performance of a play or piece of music conforms to the author's intention, or to how closely a work of art conforms to an artistic tradition. The second sense refers to how much the work possesses original or inherent authority, how much sincerity, genuineness of expression, and moral passion the artist or performer puts into the work. A quite different concern is the authenticity of the experience, which may be impossible to achieve. A modern visitor to a museum may not only see an object in a very different context from that which the artist intended, but may be unable to understand important aspects of the work. The authentic experience may be impossible to recapture. Authenticity is a requirement for inscription upon the UNESCO World Heritage List. According to the Nara Document on Authenticity, it can be expressed through 'form and design; materials and substance; use and function; traditions and techniques; location and setting; spirit and feeling; and other internal and external factors.'
  • 5.9K
  • 09 Nov 2022
Topic Review
Smart Systems and IoT for Aquaponics Automation
Aquaponics is an innovative, smart, and sustainable agricultural technology that integrates aquaculture (farming of fish) with hydroponics in growing vegetable crops symbiotically. The correct implementation of aquaponics helps in providing healthy organic foods with low consumption of water and chemical fertilizers. Numerous research attempts have been directed toward real implementations of this technology feasibly and reliably at large commercial scales and adopting it as a new precision technology. For better management of such technology, there is an urgent need to use the Internet of things (IoT) and smart sensing systems for monitoring and controlling all operations involved in the aquaponic systems.
  • 5.9K
  • 11 Aug 2022
Topic Review
Steroid-Induced Iatrogenic Adrenal Insufficiency
This entry focuses on steroid-induced adrenal insufficiency (SIAI) in children and discusses the latest findings by surveying recent studies. SIAI is a condition involving adrenocorticotropic hormone (ACTH) and cortisol suppression due to high doses or prolonged administration of glucocorticoids. While its chronic symptoms, such as fatigue and loss of appetite, are nonspecific, exposure to physical stressors, such as infection and surgery, increases the risk of adrenal crisis development accompanied by hypoglycemia, hypotension, or shock. The low-dose ACTH stimulation test is generally used for diagnosis, and the early morning serum cortisol level has also been shown to be useful in screening for the condition. 
  • 5.9K
  • 20 Jan 2021
Topic Review
Mindsponge Mechanism
The mindsponge mechanism (mindsponge framework, mindsponge concept, or mindsponge process) provides a way to explain how and why an individual observes and ejects cultural values conditional on the external setting. The term “mindsponge” derives from the metaphor that the mind is analogized to a sponge that squeezes out unsuitable values and absorbs new ones compatible with its core value. Thanks to the complexity and well-structuring, the mechanism has been used to develop various concepts in multiple disciplines. One such concept is "cultural additivity" (https://www.nature.com/articles/s41599-018-0189-2). Recently, the mindsponge mechanism has been developed into mindsponge theory based on various evidence from natural sciences.
  • 5.9K
  • 01 Sep 2022
Topic Review
SRY Gene
SRY: Sex determining region Y. The SRY gene provides instructions for making a protein called the sex-determining region Y protein.
  • 5.9K
  • 22 Dec 2020
Topic Review
Supercontinent Cycle
The supercontinent cycle is the quasi-periodic aggregation and dispersal of Earth's continental crust. There are varying opinions as to whether the amount of continental crust is increasing, decreasing, or staying about the same, but it is agreed that the Earth's crust is constantly being reconfigured. One complete supercontinent cycle is said to take 300 to 500 million years. Continental collision makes fewer and larger continents while rifting makes more and smaller continents.
  • 5.9K
  • 03 Nov 2022
Topic Review Peer Reviewed
Two-Lane Highways: Indispensable Rural Mobility
Two-lane highways refer to roadways consisting of two lanes in the cross section, one for each direction of travel. Occasionally, passing lanes may be added to one or two sides of the roadway extending the cross section to three or four lanes at those locations. In this entry, two-lane highways strictly refer to roads in rural areas meeting the previous definition and do not include urban and suburban streets.
  • 5.9K
  • 13 Apr 2022
Topic Review
Twin-Screw Granulation
Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from the pharmaceutical industry for its potential for the development of oral dosage forms. The technology has evolved rapidly due to the flexibility of the equipment design, the selection of the process variables and the wide range of processed materials. Most importantly, TSG offers the benefits of both batch and continuous manufacturing for pharmaceutical products, accompanied by excellent process control, high product quality which can be achieved through the implementation of Quality by Design (QbD) approaches and the integration of Process Analytical Tools (PAT). 
  • 5.9K
  • 18 May 2021
Topic Review
Distance Measures (Cosmology)
Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some observable quantity (such as the luminosity of a distant quasar, the redshift of a distant galaxy, or the angular size of the acoustic peaks in the cosmic microwave background (CMB) power spectrum) to another quantity that is not directly observable, but is more convenient for calculations (such as the comoving coordinates of the quasar, galaxy, etc.). The distance measures discussed here all reduce to the common notion of Euclidean distance at low redshift. In accord with our present understanding of cosmology, these measures are calculated within the context of general relativity, where the Friedmann–Lemaître–Robertson–Walker solution is used to describe the universe.
  • 5.9K
  • 19 Oct 2022
Topic Review
Transmission (Mechanics)
A transmission is a machine in a power transmission system, which provides controlled application of power. Often the term 5-speed transmission refers simply to the gearbox, that uses gears and gear trains to provide speed and torque block conversions from a rotating power source to another device. The term transmission properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differential, and final drive shafts. In the United States the term is sometimes used in casual speech to refer more specifically to the gearbox alone, and detailed usage differs. The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted. Often, a transmission has multiple gear ratios (or simply "gears") with the ability to switch between them as the speed varies. This switching may be done manually (by the operator) or automatically (by a control unit). Directional (forward and reverse) control may also be provided. Single-ratio transmissions also exist, which simply change the speed and torque (and sometimes direction) of motor output. In motor vehicles, the transmission generally is connected to the engine crankshaft via a flywheel or clutch or fluid coupling, partly because internal combustion engines cannot run below a particular speed. The output of the transmission is transmitted via the driveshaft to one or more differentials, which drive the wheels. While a differential may also provide gear reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at different speeds (essential to avoid wheel slippage on turns) as it changes the direction of rotation. Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation. Alternative mechanisms include torque converters and power transformation (e.g. diesel-electric transmission and hydraulic drive system). Hybrid configurations also exist. Automatic transmissions use a valve body to shift gears using fluid pressures in response to engine RPM, speed, and throttle input.
  • 5.9K
  • 01 Nov 2022
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