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Topic Review
Longitudinal Static Stability
In flight dynamics, longitudinal static stability is the stability of an aircraft in the longitudinal, or pitching, plane under steady flight conditions. This characteristic is important in determining whether a human pilot will be able to control the aircraft in the pitching plane without requiring excessive attention or excessive strength.
  • 11.7K
  • 20 Oct 2022
Topic Review
Hydraulic Actuators
Hydraulic actuators are elements converting the energy of the working fluid into mechanical energy related to the reciprocating motion. The most frequently applied materials used in power hydraulics are described, and various surface modifications of the discussed elements, which are aimed at improving the operating parameters of actuators, are presented. The most frequently used materials for actuators elements are iron alloys. However, due to rising ecological requirements, there is a tendency to looking for modern replacements to obtain the same or even better mechanical or tribological parameters. Sealing systems are manufactured mainly from thermoplastic or elastomeric polymers, which are characterized by low friction and ensure the best possible interaction of seals with the cooperating element. In the field of surface modification, among others, the issue of chromium plating of piston rods has been discussed, which, due, to the toxicity of hexavalent chromium, should be replaced by other methods of improving surface properties.
  • 11.7K
  • 23 Mar 2021
Topic Review
Unified Atomic Mass Unit
The unified atomic mass unit or dalton (symbol: u, or Da) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol. It is defined as one twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest, and has a value of 1.660539040(20)×10−27 kg, or approximately 1.66 yoctograms. The CIPM has categorised it as a non-SI unit accepted for use with the SI, and whose value in SI units must be obtained experimentally. The amu without the "unified" prefix is technically an obsolete unit based on oxygen, which was replaced in 1961. However, many sources still use the term amu but now define it in the same way as u (i.e., based on carbon-12). In this sense, most uses of the terms atomic mass units and amu, today, actually refer to unified atomic mass unit. For standardization, a specific atomic nucleus (carbon-12 vs. oxygen-16) had to be chosen because the average mass of a nucleon depends on the count of the nucleons in the atomic nucleus due to mass defect. This is also why the mass of a proton or neutron by itself is more than (and not equal to) 1 u. The atomic mass unit is not the unit of mass in the atomic units system, which is rather the electron rest mass (me).
  • 11.6K
  • 21 Oct 2022
Topic Review
God in Catholicism
God in Catholicism is the God of Abraham, Isaac, and Jacob. The Catholic Church believes that there is one true and living God, the Creator and Lord of Heaven and Earth. Despite other opinions, God is All-Perfect; this infinite Perfection is viewed, successively, under various aspects, each of which is treated as a separate perfection and characteristic inherent to the Divine Substance, or Essence. A certain group of these, of paramount import, is called the Divine Attributes. The position of the Catholic Church declared in the Fourth Lateran Council (1215), is again stated in the following pronouncement of the Vatican Council: "The Holy, Catholic, Apostolic, Roman Church believes and confesses that there is one, true, living God, Creator and Lord of heaven and earth, omnipotent, eternal, immense, incomprehensible, infinite in intellect and will, and in every perfection; who, although He is one, singular, altogether simple and unchangeable spiritual substance, must be proclaimed distinct in reality and essence from the world; most blessed in Himself and of Himself, and ineffably most high above all things which are or can be conceived outside Himself."
  • 11.6K
  • 09 Oct 2022
Topic Review
Food Colorants Analysis in Foods
Color additives are used extensively in several food products, as to enhance their appearance, and their nutritional properties. They can be defined as “any substance that its intentional addition of which to a food aiming for a technological (including organoleptic) purpose in the manufacture, processing, preparation treatment, packing, packaging, transport or holding of such food results, or may be reasonably expected to result, in it or its by-products becoming a component of the food or otherwise affecting the characteristics of such foods”. Thus, hereby they are presented all the late advancements related to existing analytical methods and sample preparation methodologies, for their determination and quantification in food matrices.Furthermore, all these advancements are connected to general information about the existing natural or synthetic food colorants, along with legislative information and toxicological aspects, in order to support the importance and the need of appropriate analytical methodologies.
  • 11.6K
  • 12 Jan 2021
Topic Review
Cost of Electricity by Source
The distinct methods of electricity generation can incur significantly different costs and these costs can occur at significantly different times relative to when the power is used. Also, calculations of these costs can be made at the point of connection to a load or to the electricity grid (ie they may or may not include the transmission costs). The costs include the initial capital, and the costs of continuous operation, fuel, and maintenance as well as the costs of de-commissioning and remediating any environmental damage. For comparing different methods, it is useful to compare costs per unit of energy which is typically given per kilowatt-hour or megawatt-hour. This type of calculation assists policymakers, researchers and others to guide discussions and decision-making but is usually complicated by the need to take account of differences in timing by means of a discount rate.
  • 11.5K
  • 13 Oct 2022
Topic Review
The Tryptophan-Kynurenine Metabolic Pathway
Tryptophan (TRP) is one of the essential amino acids, which participates in protein synthesis. The tryptophan’s main metabolic route is the kynurenine pathway (KP) through which approximately 90-95% of TRP degrades into nicotinamide adenine dinucleotide (NAD+) and other bioactive metabolites. The appropriate amount of NAD+ is essential to maintain the operation and the viability of cells. The other molecules are neurotoxic, neuroprotective, oxidant, antioxidant, and/or immune modifiers. They play an important role in the function of the brain and the peripheral tissues. The change in the levels of the bioactive molecules is considered to contribute to the development of a wide range of illnesses from cancer to immunologic, neurodegenerative, and psychiatric diseases.
  • 11.5K
  • 10 Aug 2021
Topic Review
Eastern Orthodox Church Organization
The Eastern Orthodox Church is a communion comprising the fourteen or sixteen separate autocephalous (self-governing) hierarchical churches that recognize each other as "canonical" Eastern Orthodox Christian churches. Each constituent church is self-governing; its highest-ranking bishop called the primate (a patriarch, a metropolitan or an archbishop) reports to no higher earthly authority. Each regional church is composed of constituent eparchies (or dioceses) ruled by bishops. Some autocephalous churches have given an eparchy or group of eparchies varying degrees of autonomy (limited self-government). Such autonomous churches maintain varying levels of dependence on their mother church, usually defined in a tomos or other document of autonomy. In many cases, autonomous churches are almost completely self-governing, with the mother church retaining only the right to appoint the highest-ranking bishop (often an archbishop or metropolitan) of the autonomous church. Normal governance is enacted through a synod of bishops within each church. In case of issues that go beyond the scope of a single church, multiple self-governing churches send representatives to a wider synod, sometimes wide enough to be called an Eastern Orthodox "ecumenical council". Such councils are deemed to have authority superior to that of any autocephalous church or its ranking bishop.
  • 11.5K
  • 14 Oct 2022
Topic Review
Germplasm Conservation
Germplasm is a valuable natural resource that provides knowledge about the genetic composition of a species and is crucial for conserving plant diversity. Germplasm protection strategies not only involve rescuing plant species threatened with extinction, but also help preserve all essential plants, on which rests the survival of all organisms. The successful use of genetic resources necessitates their diligent collection, storage, analysis, documentation, and exchange. Slow growth cultures, cryopreservation, pollen and DNA banks, botanical gardens, genetic reserves, and farmers’ fields are a few germplasm conservation techniques being employed. However, the adoption of in-vitro techniques with any chance of genetic instability could lead to the destruction of the entire substance, but the improved understanding of basic regeneration biology would, in turn, undoubtedly increase the capacity to regenerate new plants, thus expanding selection possibilities. Germplasm conservation seeks to conserve endangered and vulnerable plant species worldwide for future proliferation and development; it is also the bedrock of agricultural production. 
  • 11.5K
  • 25 Jun 2021
Topic Review
Subject–Verb–Object
In linguistic typology, subject–verb–object (SVO) is a sentence structure where the subject comes first, the verb second, and the object third. Languages may be classified according to the dominant sequence of these elements in unmarked sentences (i.e., sentences in which an unusual word order is not used for emphasis). English is included in this group. An example is "Sam ate oranges." The label often includes ergative languages that do not have subjects, but have an agent–verb–object (AVO) order. SVO is the second-most common order by number of known languages, after SOV. Together, SVO and SOV account for more than 75% of the world's languages. It is also the most common order developed in Creole languages, suggesting that it may be somehow more initially "obvious" to human psychology. Languages regarded as SVO include: All Bantu languages, Albanian, Arabic dialects, Assyrian, Bosnian, Bulgarian,[a 1] Chinese, English, Estonian, Finnish (but see below), French, Greek, Hausa, Icelandic (with the V2 restriction), Igbo, Italian, Javanese, Khmer, Latvian, Macedonian, Malay (Indonesian, Malaysian), Modern Hebrew, Norwegian (with the V2 restriction), Polish, Portuguese, Quiché, Reo Rapa, Romanian, Russian (but see below), Slovene, Spanish, Swedish (with the V2 restriction), Thai and Lao, Ukrainian (but see below), Vietnamese and Yoruba. Ancient Greek has free syntactic order, though Classical Greeks tended to favor SOV. Many famous phrases are SVO, however.
  • 11.4K
  • 29 Nov 2022
Topic Review
Physical Properties of Food Materials
The physical properties of food materials have defined those properties that can only be measured by physical means rather than chemical means. Food materials are basically naturally occurring biological-originated raw materials that have their own exclusive physical identity that makes them unique in nature. Due to the uniqueness of their physical properties, to properly measure the different physical characteristics of any food materials to get control and understand about the changes in their native physical characteristics with the influence of time-temperature-processing-treatment-exposure, proper measurement techniques for various physical properties of food materials are required with numerous desired outputs.
  • 11.4K
  • 25 Feb 2022
Topic Review
Right-Wing Authoritarianism
In psychology, the right-wing authoritarian (RWA) is a personality type that describes somebody who is naturally submissive to their authority figures, acts aggressively in the name of said authorities, and is conformist in thought and behavior. The prevalence of this personality type in a population varies from culture to culture, as a person's upbringing and education play a strong role in determining whether somebody develops this sort of personality. The right-wing authoritarian personality was defined by Bob Altemeyer as a refinement of the research of Theodor Adorno. Adorno was the first to propose the existence of an authoritarian personality as part of an attempt to explain the rise of fascism and the Holocaust, but his theory fell into disfavor because it was based on Freudian pseudo-science. Altemeyer nonetheless felt that Adorno was on to something, and so developed a more scientifically-rigorous theory now known as the RWA scale. The RWA scale was designed to measure authoritarianism in North America. It has proven to be reasonably reliable in English-speaking countries such as Australia, but less so in other countries such as France due to cultural differences and translation issues.
  • 11.4K
  • 08 Oct 2022
Topic Review
Ievan Polkka
"Ievan Polkka" or "Ievan Polokka" (Savo Finnish for "Eva's Polka") is a popular Finland song with lyrics written in the early 1930s by Eino Kettunen to a traditional Finnish polka tune. The name is commonly misspelled Levan Polkka, due to the similarity of lowercase L and the uppercase vowel I (i) in sans-serif fonts. It is also known as "Loituma's Polka" (or "Loituma's Polkka").
  • 11.4K
  • 15 Nov 2022
Topic Review
Data Envelopment Analysis (DEA)
Data Envelopment Analysis (DEA) is a non-parametric methodology for measuring the efficiency of Decision Making Units (DMUs) using multiple inputs to outputs configurations. This is the most commonly used tool for frontier estimations in assessments of productivity and efficiency applied to all fields of economic activities.
  • 11.4K
  • 28 Jan 2022
Topic Review
Mobile Technology in Tourism
The influence of mobile technology on tourism is very significant. With the support of mobile-related devices (smartphones, glasses, or other wearable devices), technology, data and services, multiple travel concepts, and travel modes including mobile tourism, smart tourism, e-tourism, and sustainable tourism have emerged or developed further. Mobile technology is touted as the next technology wave that can fundamentally change tourism and hotels. Moreover, mobile technology is playing an increasing role in the travel experience, and increasing travel research is concentrated in this field. Research findings show that, first, the research of mobile technology in tourism can be divided into three phases and to a certain extent is synchronized with the development of mobile technology. Second, in the area of social sciences, the research of mobile technology in tourism needs further exploration, which must refer to related research in the areas of Transportation and IT to expand the perspective of research. Top journal analysis, journal co-citation analysis, author co-citation analysis, and collaboration network analysis reveal the most representative journals, authors, institutions, and countries/regions in this research field. This finding provides a valuable reference for scholars in this field. Additionally, this research also grasped the hot and cutting-edge topics in this field through the analysis of keywords in this field. Finally, the clustering of co-citation references presents the knowledge base of mobile technology research in the tourism field: mobile technology, travel mode, mobile instrument, travel behavior research, mobile applications, and geo-based technology.
  • 11.3K
  • 28 Sep 2020
Topic Review
Effect of COVID-19 Pandemic on the Fashion Industry
The preference for a specific fashion style proved to have an impact on the product, promotion, WOM and fashion lovers’ behavior during COVID-19. Moreover, those elements have an impact on the frequency of fashion apparel consumption. Based on these results, fashion companies can tailor their activities in line with the predominant style of their fashion apparel to improve their economic sustainability during the post-COVID-19 era. 
  • 11.3K
  • 06 May 2022
Topic Review
Electric Vehicles Adoption Scenario in Malaysia
In the roadmaps of the automotive industry, the electric vehicle (EV) is regarded as a crucial technology for the future of automotive power systems. The EV has become a top priority of major global car manufacturers and is expected to disrupt the road transportation sector. In Malaysia and Indonesia, EVs just started as an important force. However, in Malaysia, the lack of EV infrastructure, along with its strong dependency on fossil fuels, poses an enormous challenge. 
  • 11.3K
  • 05 May 2022
Topic Review
Clavicular Malignancies
The clavicle, or collar bone, is a long (6 inches in adults), tubular, S-shaped bone that is subcutaneous throughout and can be considered “special” for several reasons. It is the first bone to ossify in the embryo, with its two first ossification centers developing between the fifth and sixth weeks of gestation. Malignant clavicular tumors present with local pain, a palpable firm mass or pathological bone fracture, or with the clinical symptoms of the primary tumor (in cases of metastasis).
  • 11.3K
  • 20 Jul 2022
Topic Review
Fairy Tale
A fairy tale, fairytale, wonder tale, magic tale, or Märchen is an instance of a folklore genre that takes the form of a short story. Such stories typically feature entities such as dwarfs, dragons, elves, fairies, giants, gnomes, goblins, griffins, mermaids, talking animals, trolls, unicorns, or witches, and usually magic or enchantments. In most cultures, there is no clear line separating myth from folk or fairy tale; all these together form the literature of preliterate societies. Fairy tales may be distinguished from other folk narratives such as legends (which generally involve belief in the veracity of the events described) and explicit moral tales, including beast fables. In less technical contexts, the term is also used to describe something blessed with unusual happiness, as in "fairy-tale ending" (a happy ending) or "fairy-tale romance". Colloquially, the term "fairy tale" or "fairy story" can also mean any far-fetched story or tall tale; it is used especially of any story that not only is not true, but could not possibly be true. Legends are perceived as real; fairy tales may merge into legends, where the narrative is perceived both by teller and hearers as being grounded in historical truth. However, unlike legends and epics, fairy tales usually do not contain more than superficial references to religion and to actual places, people, and events; they take place "once upon a time" rather than in actual times. Fairy tales occur both in oral and in literary form; the name "fairy tale" ("conte de fées" in French) was first ascribed to them by Madame d'Aulnoy in the late 17th century. Many of today's fairy tales have evolved from centuries-old stories that have appeared, with variations, in multiple cultures around the world. The history of the fairy tale is particularly difficult to trace because only the literary forms can survive. Still, according to researchers at universities in Durham and Lisbon, such stories may date back thousands of years, some to the Bronze Age more than 6,500 years ago. Fairy tales, and works derived from fairy tales, are still written today. Folklorists have classified fairy tales in various ways. The Aarne-Thompson classification system and the morphological analysis of Vladimir Propp are among the most notable. Other folklorists have interpreted the tales' significance, but no school has been definitively established for the meaning of the tales.
  • 11.2K
  • 17 Nov 2022
Topic Review
Apple juice fermentation process
This work emphasized the apple fermentation process and showed how the fermentation can be affected by the first material composition and the used microorganisms.
  • 11.2K
  • 19 Aug 2020
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