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Topic Review

List of DCS Modules

The below list includes all standalone products (commonly known as "modules") in Digital Combat Simulator, an air combat video game developed by Russian developer Eagle Dynamics. Fighter aircraft, helicopters and trainer aircraft modules can be flown by human players and artificial intelligence. Aircraft carriers, tanker aircraft and airborne early warning and control aircraft cannot be operated by human players.

11.9K
14 Nov 2022

Topic Review

Kraft Pulp Mill Process

Kraft pulp mills produce a fibrous material composed of wood cellulose fibers, constituting the main raw material for papermaking. The kraft process is the dominant technology in the world to produce pulp, allowing the recycling of most of the pulping chemical in two loops, commonly referred to as the sodium cycle and calcium cycle. A third cycle is also relevant to sodium sulphate recovery. Meanwhile, significant amounts of solid, liquid and gaseous emissions are generated, requiring treatment before release into the environment. Some inorganic solid wastes are of particular concern due to the high quantities generated, which are landfilled: green liquor dregs, slaker grits, lime mud, and boiler fly ash.

11.9K
29 Oct 2020

Topic Review

Effects of Petroleum on Soil

Petroleum is the most common global fossil fuel. It is a complex multi-component system mainly composed of various hydrocarbons such as alkanes, cycloalkanes, mono-, bi- and polyaromatic compounds, resins and asphaltenes. In spite of humanity’s need for petroleum, it negatively affects the environment due to its toxicity. The ecological problem is especially serious at petroleum mining sites or during petroleum transportation. Since it is not possible to replace petroleum with less toxic fuel, ways to reduce the toxic impact of petroleum hydrocarbons on the environment need to be developed.

11.9K
08 Jul 2022

Topic Review

Digital Twin: Origin to Future

Digital Twin (DT) refers to the virtual copy or model of any physical entity (physical twin) both of which are interconnected via exchange of data in real time. Conceptually, a DT mimics the state of its physical twin in real time and vice versa. Application of DT includes real-time monitoring, designing/planning, optimization, maintenance, remote access, etc. Its implementation is expected to grow exponentially in the coming decades. The advent of Industry 4.0 has brought complex industrial systems that are more autonomous, smart, and highly interconnected. These systems generate considerable amounts of data useful for several applications such as improving performance, predictive maintenance, training, etc. A sudden influx in the number of publications related to ‘Digital Twin’ has led to confusion between different terminologies related to the digitalization of industries. Another problem that has arisen due to the growing popularity of DT is a lack of consensus on the description of DT as well as so many different types of DT, which adds to the confusion. This paper intends to consolidate the different types of DT and different definitions of DT throughout the literature for easy identification of DT from the rest of the complimentary terms such as ‘product avatar’, ‘digital thread’, ‘digital model’, and ‘digital shadow’. The paper looks at the concept of DT since its inception to its predicted future to realize the value it can bring to certain sectors. Understanding the characteristics and types of DT while weighing its pros and cons is essential for any researcher, business, or sector before investing in the technology.

11.8K
25 Jun 2021

Topic Review

Space Shuttle Main Engine

The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle and is planned to be used on its successor, the Space Launch System. Designed and manufactured in the United States by Rocketdyne (later known as Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN (418,000 lbf) of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine's reliability, safety, and maintenance load. Subsequently, the RS-25D is the most efficient liquid fuel rocket engine currently in use. The engine produces a specific impulse (Isp) of 452 seconds (4.43 km/s) in a vacuum, or 366 seconds (3.59 km/s) at sea level, has a mass of approximately 3.5 tonnes (7,700 pounds), and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. The RS-25 operates at temperatures ranging from −253 °C (−423 °F) to 3300 °C (6000 °F). The Space Shuttle used a cluster of three RS-25 engines mounted in the stern structure of the orbiter, with fuel being drawn from the external tank. The engines were used for propulsion during the entirety of the spacecraft's ascent, with additional thrust being provided by two solid rocket boosters and the orbiter's two AJ-10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, and refurbished before being reused on another mission.

11.8K
24 Oct 2022

Topic Review

HandWiki is an internet Wiki-style encyclopedia for professional researchers in various branches of science and computer science. As other Wiki type encyclopedias, HandWiki is designed for collaborative editing of articles. Unlike the traditional Wikipedia that uses the categories concept for all articles located in the main namespace, HandWiki uses dedicated namespaces for each topic. This allows creation of "Books" or "Manual" by grouping articles under the same namespace. According to the Handwiki designers, this can simplify organization of articles according to particular topic. HandWiki has the following topics included in the dedicated namespaces: Mathematics, Computers, Analysis, Physics, Astronomy, Biology, Chemistry, Unsolved. In addition to the categories preserved from Wikipedia, HandWiki has its own categories for original articles posted to HandWiki. One notable feature of HandWiki is that it allows to collaborate in real-time on many types of documents (lectures, books, technical documents, etc.) with multiple authors. The text can be protected from viewing, and can only be available for groups of people working on the same project. HandWiki can be used to convert such articles to LaTeX and to use BibTeX for referencing. These two features are a significant advantage for preparing research articles for publication. The HandWiki is designed using the MediaWiki software with additional extensions for inclusion of references to programming codes and BibTeX citations. Handwiki allows adding advertisements to the end of the articles. The advertising icons can be grouped according to the HandWiki topics.

11.8K
29 Mar 2025

Topic Review

The testing effect is the finding that long-term memory is often increased when some of the learning period is devoted to retrieving the to-be-remembered information. The effect is also sometimes referred to as retrieval practice, practice testing, or test-enhanced learning. Retrieval practice may be the best way to refer to the testing effect because the benefits of retrieval-related testing are not limited to tests. It can be more broad, including tools like flash cards and quizzes. The testing effect on memory should be distinguished from more general practice effects, defined in the APA Dictionary of Psychology (2007) as "any change or improvement that results from practice or repetition of task items or activities." The term testing effect is also sometimes used in a more general sense; The Oxford Dictionary of Psychology (2003) defines a testing effect as "any effect of taking tests on the respondents, a typical example being test sophistication." Whereas psychologists who develop tests for personality and intelligence want to avoid practice effects, cognitive psychologists working with educators have begun to understand how to take advantage of tests—not as an assessment tool, but as a teaching/learning tool. It is useful for people to test their knowledge of the to-be-remembered material during the learning process, instead of only reading or otherwise passively studying the material. For example, a student can use flashcards to self-test and receive feedback as they study. The testing effect provides a larger benefit to long-term memory when the tested material is difficult enough to require effort, the rate of retrieval success is high, and feedback with correct answers is given after testing. The testing effect is activated by active recall.

11.8K
20 Oct 2022

Topic Review

North–South Divide (England)

In England, the term North–South divide refers to the cultural, economic, and social differences between: The status of the Midlands is often disputed, however counties in the higher midlands, such as West Midlands County (Walsall Metropolitan Borough and Wolverhampton are seen as north too due to their proximity to Staffordshire and Shropshire), Shropshire, Derbyshire, Nottinghamshire, Lincolnshire, Leicestershire, and Staffordshire, are culturally very Northern. A grouping of Central England based on UK EU parliamentary constituency boundaries combines the Midlands and East Anglia. In political terms, the South, and particularly the South-East (outside Greater London) and East Anglia, is largely centre-right, and supportive of the Conservative Party, while Northern England (particularly the towns and cities) is generally more supportive of the Labour Party. An article in The Economist (15–21 September 2012) argued that the gap between the north and south in life expectancy, political inclinations and economics trends was growing to the extent that they were almost separate countries.

11.8K
11 Oct 2022

Topic Review

Hyperspectral Remote Sensing

Hyperspectral imaging is an incorporation of the modern imaging system and traditional spectroscopy technology. Unmanned aerial vehicle (UAV) hyperspectral imaging techniques have recently emerged as a valuable tool in agricultural remote sensing, with tremendous promise for many application such as weed detection and species separation

11.8K
21 Mar 2022

Topic Review

Humid Subtropical Climate

A humid subtropical climate is a zone of climate characterized by hot, humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents, generally between latitudes 25° and 35° and are located poleward from adjacent tropical climates. While many subtropical climates tend to be located at or near coastal locations, in some cases they extend inland, most notably in China and the United States , where they exhibit more pronounced seasonal variations and sharper contrasts between summer and winter, as part of a gradient between the more tropical climates of the southern coasts of these countries and the more continental climates of China and the United States ' northern and central regions (localities around the Ohio and Yangtze rivers exhibiting continental influence from the north, compared to climates around the Gulf of Mexico and the South China Sea, which exhibit tropical influence due to their southern coastal positions). The humid subtropical climate classification was officially created under the Trewartha Climate classification. Trewartha attempted to redefine middle latitude climates in the Koppen system since many climatologists argued that his "C" climate zone was too broad. Trewartha attempted to separate the middle latitude in three zones (subarctic, temperate, and subtropical). In this classification, climates are termed humid subtropical when they have at least 8 months with a mean temperature above 10 °C (50 °F). Under the Holdridge life zones classification, the subtropical climates have a biotemperature between the frost or critical temperature line, 16 to 18 °C (61 to 64 °F) (depending on locations in the world) and 24 °C (75 °F), and these climates are humid (or even perhumid or superhumid) when the potential evapotranspiration (PET) ratio (= PET / Precipitation) is less than 1. In the Holdridge classification, the humid subtropical climates coincide more or less with the warmest Cfa and Cwa climates and the less warm humid tropical "Köppen" climates (Aw, Am and Af). In a humid subtropical climate, summers are typically long, hot and humid. Monthly mean summer temperatures are normally between 24 and 27 °C (75 and 81 °F). A deep current of tropical air dominates the humid subtropics at the time of high sun, and daily intense (but brief) convective thundershowers are common. Summer high temperatures are typically in the high 20s to mid-30s °C (80s or 90s °F), while overnight lows in the summer are typically in the lower 20s °C (70s °F). Monthly mean temperatures in winter are often mild, typically averaging 7.5 to 16 °C (45.5 to 60.8 °F). Daytime highs in winter normally are in the 10 to 16 °C (50 to 61 °F) range, while overnight lows are from 2 to 7 °C (36 to 45 °F), though the poleward boundaries of this climate feature colder temperatures. Rainfall often shows a summer peak, especially where monsoons are well developed, as in Southeast Asia and South Asia. Other areas have a more uniform or varying rainfall cycles, but consistently lack any predictably dry summer months. Most summer rainfall occurs during thunderstorms that build up due to the intense surface heating and strong subtropical sun angle. Weak tropical lows that move in from adjacent warm tropical oceans, as well as infrequent tropical storms often contribute to summer seasonal rainfall peaks. Winter rainfall is often associated with large storms in the westerlies that have fronts that reach down into subtropical latitudes. However, many subtropical climates such as southeast Asia and Florida in the United States have very dry winters, with frequent brush fires and water shortages.

11.8K
01 Dec 2022

Topic Review

Design Concepts for Floating Offshore Wind Turbines

Offshore wind energy is a sustainable renewable energy source that is acquired by harnessing the force of the wind offshore, where the absence of obstructions allows the wind to travel at higher and more steady speeds. Offshore wind has recently grown in popularity because wind energy is more powerful offshore than on land.

11.8K
10 Jan 2023

Topic Review

Queer theory is a field of critical theory that emerged in the early 1990s out of the fields of queer studies and women's studies. Queer theory includes both queer readings of texts and the theorization of 'queerness' itself. Heavily influenced by the work of Lauren Berlant, Leo Bersani, Judith Butler, Lee Edelman, Jack Halberstam, and Eve Kosofsky Sedgwick, queer theory builds both upon feminist challenges to the idea that gender is part of the essential self and upon gay/lesbian studies' close examination of the socially constructed nature of sexual acts and identities. Whereas gay/lesbian studies focused its inquiries into natural and unnatural behavior with respect to homosexual behavior, queer theory expands its focus to encompass any kind of sexual activity or identity that falls into normative and deviant categories. Italian feminist and film theorist Teresa de Lauretis coined the term "queer theory" for a conference she organized at the University of California, Santa Cruz in 1990 and a special issue of Differences: A Journal of Feminist Cultural Studies she edited based on that conference. Through the context of heterosexuality being the origin and foundation of society’s heteronormative stability, the concept of queerness focuses on, “mismatches between sex, gender and desire” Queerness has been associated most prominently with bisexual, lesbian and gay subjects, but its analytic framework also includes such topics as cross-dressing, intersex bodies and identities, gender ambiguity and gender-corrective surgery. Queer theory holds that individual sexuality is a fluid, fragmented, and dynamic collectivity of possible sexualities and it may vary at different points of his life. Its attempted debunking of stable (and correlated) sexes, genders, and sexualities develops out of the specifically lesbian and gay reworking of the post-structuralist figuring of identity as a constellation of multiple and unstable positions. Queer theory also examines the discourses of homosexuality developed in the last century in order to place the "queer" into historical context, deconstructing contemporary arguments both for and against this latest terminology.

11.7K
17 Oct 2022

Topic Review

Types of Transcatheter Aortic Valve Replacement Devices

Transcatheter aortic valve replacement (TAVR) was originally conceptualized in the early 1990s, largely inspired by the pioneering experiences in the field of percutaneous transluminal coronary angioplasty.

11.7K
03 Aug 2022

Topic Review

Tyrannosaurus is a genus of large theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), often called T. rex or colloquially T-Rex, is one of the best represented theropods. Tyrannosaurus lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the Upper Cretaceous period, 68 to 66 million years ago. It was the last known member of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, the forelimbs of Tyrannosaurus were short but unusually powerful for their size, and they had two clawed digits. The most complete specimen measures up to 12.3–12.4 m (40.4–40.7 ft) in length; however, according to most modern estimates, T. rex could grow to lengths of over 12.4 m (40.7 ft), up to 3.66–3.96 m (12–13 ft) tall at the hips, and 8.87 metric tons (9.78 short tons) in body mass. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it is still among the largest known land predators and is estimated to have exerted the strongest bite force among all terrestrial animals. By far the largest carnivore in its environment, Tyrannosaurus rex was most likely an apex predator, preying upon hadrosaurs, juvenile armored herbivores like ceratopsians and ankylosaurs, and possibly sauropods. Some experts have suggested the dinosaur was primarily a scavenger. The question of whether Tyrannosaurus was an apex predator or a pure scavenger was among the longest debates in paleontology. Most paleontologists today accept that Tyrannosaurus was both an active predator and a scavenger. Specimens of Tyrannosaurus rex include some that are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology, including its life history and biomechanics. The feeding habits, physiology, and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial, as some scientists consider Tarbosaurus bataar from Asia to be a second Tyrannosaurus species, while others maintain Tarbosaurus is a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus. As the archetypal theropod, Tyrannosaurus has been one of the best-known dinosaurs since the early 20th century and has been featured in film, advertising, postal stamps, and many other media.

11.7K
06 Dec 2022

Topic Review

Criticisms of Neoclassical Economics

Neo-classical economics has come under critique on the basis of its core ideologies, assumptions, and other matters.

11.7K
29 Nov 2022

Topic Review

Recovery of Banana Waste-Loss

Banana is a tropical fruit grown in more than 130 countries. It is the second most produced fruit after citrus, contributing around 16% of world fruit production and the fourth most important food crop after rice, wheat and corn. Banana is very nutritious and digests better than many other fruits. After harvest, almost 60% of banana biomass is left as waste. Worldwide, about 114.08 million metric tons of banana waste-loss are produced, leading to environmental problems such as the excessive emission of greenhouse gases. These wastes contain a high content of paramount industrial importance, such as cellulose, hemicellulose and natural fibers that various processes can modify, such as bacterial fermentation and anaerobic degradation, to obtain bioplastics, organic fertilizers and biofuels such as ethanol, biogas, hydrogen and biodiesel. In addition, they can be used in wastewater treatment methods by producing low-cost biofilters and obtaining activated carbon from rachis and banana peel. Furthermore, nanometric fibers commonly used in nanotechnology applications and silver nanoparticles useful in therapeutic cancer treatments, can be produced from banana pseudostems.

11.6K
22 Sep 2021

Topic Review

Ingredients of Moisturizers

Moisturizers are one of the most widely used preparations in cosmetics and have been extensively used to soften the skin for consumers. Moisturizers work effectively in combating dry skin which may cause pain, tightness, itch, stinging, and/or tingling. Knowing the characteristics and interactions of active ingredients with the skin will allow for better utilization of available moisturizers.

11.6K
11 Jul 2022

Topic Review

Water literacy may be considered generally as the culmination of water-related knowledge, attitudes and behaviors. It holds growing importance for sustainable water resource use and management. While use and definitions of the concept of water literacy vary broadly in the literature, the synthesis of these identifies common elements and themes in a holistic framework.

11.6K
03 Feb 2022

Topic Review

As is widely recognized, rainfall data is necessary for the mathematical modelling of extreme hydrological events, such as droughts or floods, as well as for evaluating surface and subsurface water resources and their quality. The phase, quantity, and elevation of generic hydrometeors in the atmosphere can be estimated by ground-based radars. Satellites can provide images with visible and infrared radiation, and they can also serve as platforms for radiometers to derive the quantity and phase of hydrometeors. Radars and satellites provide spatial information on precipitation at wide scales, avoiding many problems connected to local ground measurements, including those for the areal inhomogeneity of a network. However, direct rainfall observations at point scale can be obtained only by rain gauges installed at the soil surface.

11.6K
29 Jan 2022

Topic Review

Clay bricks are extensively used as building material worldwide. Natural soil deposits are in constant reduction due to the frequent use of clay to manufacture bricks. About 1600 billion bricks are produced annually by the consumption of millions of tons of natural resources.

11.6K
18 Sep 2021

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