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Topic Review
Transparency for Architecture
Rowe and Slutzky proposed two types of transparency in architecture in the essay, “Transparency: Literal and Phenomenal”. They divided transparency into literal, meaning the material conditions of glass, and phenomenal, as derived from Cubist paintings. “literal transparency” describes the material quality of being see-through, and phenomenal transparency describes the perceptual attributes that allow the mind to discern the underlying governing concepts or spatial concepts. Through their idea of “phenomenal transparency”, they primarily investigated the relationship of visual perceptions using the human eye with superimposed two-dimensional visions of architectural space and the world.
  • 8.2K
  • 27 Aug 2021
Topic Review
Urban Open Space
In land-use planning, urban open space is open-space areas reserved for parks, "green spaces", and other open areas. The landscape of urban open spaces can range from playing fields to highly maintained environments to relatively natural landscapes. Generally considered open to the public, urban open spaces are sometimes privately owned, such as higher education campuses, neighborhood/community parks/gardens, and institutional or corporate grounds. Areas outside city boundaries, such as state and national parks as well as open space in the countryside, are not considered urban open space. Streets, piazzas, plazas and urban squares are not always defined as urban open space in land use planning.
  • 8.2K
  • 14 Oct 2022
Topic Review
SpaceX Dragon 2
The SpaceX Dragon 2 is a class of reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX as the successor to the Dragon cargo spacecraft. It has two variants: Crew Dragon, a human-rated capsule capable of ferrying up to seven astronauts, and Cargo Dragon, an updated replacement for the original Dragon spacecraft. The spacecraft launches atop a Falcon 9 Block 5 rocket and returns to Earth via an ocean splashdown. Unlike its predecessor, the spacecraft can dock itself to the ISS instead of being berthed. Crew Dragon is equipped with an integrated launch escape system (LES) capable of accelerating the vehicle away from the rocket in an emergency at 11.8 m/s2, accomplished by using a set of four side-mounted thruster pods with two SuperDraco engines each. The spacecraft features redesigned solar arrays and a modified outer mold line compared to the original Dragon, and possess new flight computers and avionics. As of March 2020, four Dragon 2 spacecraft have been manufactured (not counting structural test articles that were never airborne). Crew Dragon serves as one of two spacecraft that is expected to transport crews to and from the International Space Station (ISS) under NASA's Commercial Crew Program, the other being the Boeing CST-100 Starliner. It is also expected to be used in flights by American space tourism company Space Adventures and to shuttle tourists to and from Axiom Space's planned space station. Crew Dragon's first non-piloted test flight occurred in March 2019, and its first crewed flight – with astronauts Robert Behnken and Douglas Hurley – occurred in May 2020. This test flight marked the first time a private company launched a crewed orbital spacecraft. Cargo Dragon is expected to supply cargo to the ISS under a Commercial Resupply Services-2 contract with NASA, along with Northrop Grumman Innovation Systems' Cygnus spacecraft and Sierra Nevada Corporation's Dream Chaser spacecraft. The first flight of the Cargo Dragon is planned to launch in October 2020.
  • 8.2K
  • 26 Oct 2022
Topic Review
List of Kakapo
There are fewer than 250 living individuals of the critically endangered kakapo, a large, flightless parrot native to New Zealand. Every known living kakapo, except some young chicks, has been given a name by officials of the Kakapo Recovery Programme. Many of the older birds were given English-language names, but more recent chicks have been given Māori names. Some kakapo, such as Richard Henry and Moorhouse, are named after people who have provided assistance to the preservation efforts. A kakapo interactive family tree is available.
  • 8.2K
  • 17 Sep 2024
Topic Review
Polyelectrolyte
Polyelectrolytes are polymers of oppositely charged ions and their properties differ profoundly than their repeating units. Over recent years, much advancement has been made in the synthesis, characterization, and application of polyelectrolytes and polyelectrolyte complexes (PECs). It has many applications as flocculation agents, dispersant agents, and as super-plasticizers. In this article, the synthesis, types, characteristics, and application of PECs mainly for drug delivery and dynamics study are reviewed.
  • 8.2K
  • 27 Oct 2020
Topic Review
Red Supergiant Star
Red supergiants (RSGs) are stars with a supergiant luminosity class (Yerkes class I) of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antares are the brightest and best known red supergiants (RSGs), indeed the only first magnitude red supergiant stars.
  • 8.2K
  • 18 Nov 2022
Biography
Stephen Hawking
Stephen William Hawking CH CBE FRS FRSA (8 January 1942 – 14 March 2018) was an English theoretical physicist, cosmologist, and author who was director of research at the Centre for Theoretical Cosmology at the University of Cambridge at the time of his death.[1][2][3] He was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009. Hawking was born in Oxford
  • 8.2K
  • 30 Nov 2022
Topic Review
Wine Tourism
Nowadays, wine has become an important beverage that is increasingly being consumed more frequently all over the world, and its production and marketing has received increasing attention from consumers, specialists, and producers. As a result, the growing importance of wine tourism for many destinations and the role of this type of tourism in supporting local economies is now beginning to be understood. It has also been highlighted that wine tourism can play a significant role in the development of tourism by contributing to the economic and social support of local regions and communities. Wine is one of the ingredients of people's journeys, and journeys dedicated to wine-producing areas have led to the tourism product known as wine tourism.
  • 8.2K
  • 18 Apr 2022
Topic Review
Left-Wing Market Anarchism
Left-wing market anarchism is a strand of free-market anarchism and an individualist anarchist, left-libertarian and libertarian socialist political philosophy and market socialist economic theory stressing the value of radically free markets, termed freed markets to distinguish them from the common conception which these libertarians believe to be riddled with statist and capitalist privileges. Proponents of this approach distinguish themselves from right-libertarians and strongly affirm the classical liberal ideas of self-ownership and free markets while maintaining that taken to their logical conclusions these ideas support anti-capitalist, anti-corporatist, anti-hierarchical and pro-labor positions in economics; anti-imperialism in foreign policy; and thoroughly radical views regarding socio-cultural issues. Key theorists in this area include contemporary scholars such as Kevin Carson, Gary Chartier, Charles W. Johnson, Roderick T. Long, Chris Matthew Sciabarra, Ryan Neugebauer, Sheldon Richman and Brad Spangler. The genealogy of left-wing market anarchism, sometimes labeled market-oriented or free-market left-libertarianism, overlaps to a significant degree with that of Steiner–Vallentyne left-libertarianism as the roots of that tradition are sketched in the book The Origins of Left-Libertarianism. Carson–Long-style left-libertarianism is rooted in 19th-century mutualism and in the work of figures such as Thomas Hodgskin, French Liberal School thinkers such as Gustave de Molinari and American individualist anarchists such as Benjamin Tucker and Lysander Spooner, among others. Several left-wing market anarchists who come from the left-Rothbardian school or tradition cite Murray Rothbard's homestead principle with approval to support worker cooperatives. While with notable exceptions libertarians in the United States after the heyday of individualist anarchism tended to ally with the political right, relationships between such libertarians and the New Left thrived in the 1960s, laying the groundwork for modern left-wing market anarchism. Left-wing market anarchism identifies with left-libertarianism, a position which names several related yet distinct approaches to politics, society, culture and political and social theory, stressing both individual freedom and social justice. Unlike right-libertarians, left-libertarians believe that neither claiming nor mixing one's labor with natural resources is enough to generate full private property rights and maintain that all natural resources such as land, oil and gold ought to be held in some egalitarian manner, either unowned or owned collectively. Those left-libertarians who support private property do so under different property norms and theories, or under the condition that recompense is offered to the local or global community.
  • 8.2K
  • 30 Nov 2022
Topic Review
Triceratops
Triceratops (/traɪˈsɛrəˌtɒps/ trahy-ser-uh-tops; lit. three-horned face) is a genus of herbivorous chasmosaurine ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous period, about 68 million years ago in what is now North America. It is one of the last-known non-avian dinosaur genera, and became extinct in the Cretaceous–Paleogene extinction event 66 million years ago. The name Triceratops, which literally means 'three-horned face', is derived from the Greek words trí- (τρί-) meaning 'three', kéras (κέρας) meaning 'horn', and ṓps (ὤψ) meaning 'face'. Bearing a large bony frill, three horns on the skull, and a large four-legged body, exhibiting convergent evolution with rhinoceroses and bovines, Triceratops is one of the most recognizable of all dinosaurs and the most well-known ceratopsid. It was also one of the largest, up to 8–9 metres (26–30 ft) long and 5–9 metric tons (5.5–9.9 short tons) in body mass. It shared the landscape with and was most likely preyed upon by Tyrannosaurus, though it is less certain that two adults did battle in the fanciful manner often depicted in museum displays and popular images. The functions of the frills and three distinctive facial horns on its head have long inspired debate. Traditionally, these have been viewed as defensive weapons against predators. More recent interpretations find it probable that these features were primarily used in species identification, courtship, and dominance display, much like the antlers and horns of modern ungulates. Triceratops was traditionally placed within the "short-frilled" ceratopsids, but modern cladistic studies show it to be a member of the Chasmosaurinae which usually have long frills. Two species, T. horridus and T. prorsus, are considered valid today, from the seventeen species that have ever been named. Research published in 2010 concluded that the contemporaneous Torosaurus, a ceratopsid long regarded as a separate genus, represents Triceratops in its mature form. This view has been disputed; further data is needed to settle the debate. Triceratops has been documented by numerous remains collected since the genus was first described in 1889 by American paleontologist Othniel Charles Marsh. Specimens representing life stages from hatchling to adult have been found. As the archetypal ceratopsid, Triceratops is one of the most popular dinosaurs, and has been featured in film, postal stamps, and many other types of media.
  • 8.2K
  • 01 Nov 2022
Topic Review
Woodward Effect
The Woodward effect, also referred to as a Mach effect, is part of a hypothesis proposed by James F. Woodward in 1990. The hypothesis states that transient mass fluctuations arise in any object that absorbs internal energy while undergoing a proper acceleration. Harnessing this effect could generate a reactionless thrust, which Woodward and others claim to measure in various experiments. Hypothetically, the Woodward effect would allow for field propulsion spacecraft engines that would not have to expel matter. Such a proposed engine is sometimes called a Mach effect thruster (MET) or a Mach Effect Gravitational Assist (MEGA) drive. So far, experimental results have not strongly supported this hypothesis, but experimental research on this effect, and its potential applications, continues. The Space Studies Institute was selected as part of NASA's Innovative Advanced Concepts program as a Phase I proposal in April 2017 for Mach Effect research. The year after, NASA awarded a NIAC Phase II grant to the SSI to further develop these propellantless thrusters. The effect is controversial within mainstream physics because the underlying model proposed for it appears to be faulty, resulting in violations of energy conservation as well as momentum conservation.
  • 8.2K
  • 16 Nov 2022
Topic Review
Biochemistry of Hydrogen Peroxide
Hydrogen Peroxide (H2O2) is the nonionized 2-electron reduction product of unstable molecular oxygen (O2), which plays a central role in maintaining the redox cycle of living cells.
  • 8.2K
  • 10 Jan 2022
Topic Review
Green Monopropellants
Green propellants are usually defined as low-hazard, low-toxicity, environmentally friendly propellants that are considered safe during various phases of spacecraft development, launch, and operations. Such propellants provide safe handling and storability when compared to conventional toxic propellants such as hydrazine and its derivatives that require special handling protocols and adhering to strict safety measurements that, in addition to others, include using Self-Contained Atmospheric Protective Ensemble (SCAPE) suits. Due to their favorable characteristics, green propellants demonstrate higher commercial value by being able to cut costs related to transportation, storage, handling, and further reduces ground operations time. Recently, a more specified definition has been noted by Mayer et al. (2018) [3], based on the Acute Toxicity Classification (ATC) by the Global Harmonized System of classification and labeling of chemicals (GHS) [6], which denotes that propellants possessing ATC levels of three and safer are considered as green propellants. ATC levels are typically categorized on a 1:5 scale where level one denotes the most toxic class and level five is considered the least toxic class. Moreover, a controversial topic arises when referring to some modern green propellants, whether to address them by the term “monopropellants” or by more specific terms including (premixed propellants, fuel blends, or mixtures). Monopropellants are fundamentally defined as propellants consisting of chemical compounds (for example N2H4), which release energy through exothermic chemical decomposition. Since the evolution of liquid gun propellants based on HAN compound and other nitrate salts aqueous solutions, the term “monopropellants” was used to describe such premixed formulations. As widely used in literature and industry, some modern green propellants, for instance the Energetic Ionic Liquids (EILs), are undoubtedly classified and described as “monopropellants.” Basically, it can be interpreted from the previous that a "green monopropellant" may be defined as: "A low-hazard, low-toxicity, and safe-to handle propellant that is stored in a single tank and is able to decompose from its storage state by the help of a catalyst or other ignition method, such as thermal or electric ignition, can be considered a “green monopropellant” as long as it does not require another separately stored propellant for decomposition."
  • 8.2K
  • 28 Sep 2021
Topic Review
Various Attachments for Implant Overdentures
This study presents an overview of the biomechanical and biomolecular aspects of various attachments for implant overdenture. We focused on the following topics: attachment systems, retention of various attachments, stress distribution with different attachments, the design and fabrication of attachments, digital techniques in overdenture attachments, and the effects of attachments in peri-implant health. We found that plastic resin is commonly used for ball and bar attachments, whereas nylon resin is commonly used in locator attachments. The locator system offers a valuable attachment option for implant-retained overdenture. Attachment retention reduces while lateral force increases with implant inclination in overdenture. The higher the retention of an overdenture attachment, the higher the transferred stresses. Additionally, clip loading produces more stress in implants and precision elements than bar-retained dentures. As such, we conclude that the ball and locator systems the best overdenture systems due to their superior tissue response, survival rate, and patient satisfaction.
  • 8.2K
  • 03 Nov 2021
Topic Review
Hauran
Hauran (Arabic: حوران / ALA-LC: Ḥawrān), also spelled Hawran, Houran and Horan, known to the Ancient Greeks and Romans as Auranitis, is a volcanic plateau, a geographic area and a people located in southwestern Syria and extending into the northwestern corner of Jordan, it’s known to be the birth place of the dabke dance which is the most popular dance in all of the Levant.
  • 8.2K
  • 10 Nov 2022
Topic Review
Foreign Influences on Pompeii
Several non-native societies had an influence on Ancient Pompeian culture. Historians’ interpretation of artefacts, preserved by the Eruption of Mount Vesuvius in 79, identify that such foreign influences came largely from Ancient Greece and Hellenistic cultures of the Eastern Mediterranean, including Egypt. Greek influences were transmitted to Pompeii via the Greek colonies in Magna Graecia (Southern Italy), which were formed in the 8th century BC. Hellenistic influences originated from Roman commerce, and later conquest of Egypt from the 2nd century BC. Specifically, these cultures contributed to the development of Pompeii’s art, architecture and religious spheres. For instance, Greek influences can be identified in the Alexander Mosaic, horse-shoe shaped theatres and Pompeii’s adoption of the Greek pantheon of gods. Examples of Egyptian influences can be found in the Nile Mosaic, garden art in the Villa of Julia Felix and the Cult of Isis.
  • 8.2K
  • 11 Oct 2022
Topic Review
Factors Affecting Hair Health
Hair health is associated with personal distress and psychological well-being. Even though hair loss (alopecia) does not affect humans’ biological health, it affects an individual’s social well-being. So, treatment for hair problems and improving hair health are obligatory. 
  • 8.1K
  • 07 Feb 2023
Topic Review
Collective Consciousness
Collective consciousness, a concept introduced by sociologist Emile Durkheim, refers to the shared beliefs, values, norms, and symbols that unite members of a society and shape their collective identity. It represents the collective understanding of social reality, guiding individuals' behaviors, interactions, and perceptions within a community. Collective consciousness fosters social cohesion, solidarity, and integration by providing a common framework for interpreting the world and coordinating social action.
  • 8.1K
  • 08 Feb 2024
Topic Review
Traditional Fermented Foods in Korea
Fermented foods are loved and enjoyed worldwide and are part of a tradition in several regions of the world. Koreans have traditionally had a healthy diet since people in this region have followed a fermented-foods diet for at least 5000 years. Fermented-product footprints are evolving beyond boundaries and taking the lead in the world of food. Fermented foods, such as jang (fermented soybean products), kimchi (fermented vegetables), jeotgal (fermented fish), and vinegar (liquor with grain and fruit fermentation), are prominent fermented foods in the Korean culture.
  • 8.1K
  • 09 Dec 2022
Topic Review
Social Complexity
Social complexity refers to the intricate and interconnected nature of social systems, where various elements such as institutions, individuals, and cultural dynamics interact in non-linear and unpredictable ways. It involves the recognition that social phenomena often exhibit emergent properties that cannot be fully understood by analyzing individual components in isolation, emphasizing the need for interdisciplinary approaches to grasp the complexity of social structures and behaviors.
  • 8.1K
  • 26 Jan 2024
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