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Topic Review
Synthesis of Monoterpene Thiols
Thiols are one of the most convenient synthons in the synthesis of organosulfur compounds. The typical methods to prepare monoterpene thiols include the electrophilic addition of H2S or dithiols to the double bond of monoterpenes; nucleophilic substitution of halides; tosylates/mesylates obtained from corresponding monoterpene alcohols; thia-Michael addition of S-nucleophiles to α,β-unsaturated ketones; nucleophilic epoxide ring opening; nucleophilic substitution of the activated methylene protons; and reduction of sulfochlorides, dithiolanes, thiiranes, and sultones.
  • 6.7K
  • 07 Nov 2023
Topic Review
Ex Nihilo
Ex nihilo is Latin for "out of nothing": when phrased as ex nihilo nihil fit, "nothing comes from nothing", it means that the universe was formed from eternal matter; as creatio ex nihilo, "creation out of nothing", it means that matter is not eternal but had to be created by some eternal uncaused cause, frequently defined as God. Creation ex nihilo is a theistic answer to the question of how the universe comes to exist: the Big Bang theory, by contrast, is a scientific theory; it offers no explanation of cosmic existence but only a description of the first few moments of that existence.
  • 6.7K
  • 28 Sep 2022
Topic Review
Royal Ordnance L7
The Royal Ordnance L7 is the basic model of the United Kingdom 's most successful tank gun. The L7 is a 105 mm L/52 rifled design by the Royal Ordnance Factories intended for use in armoured fighting vehicles, replacing the earlier 20-pounder (84 mm) tank gun mounted on the Centurion tank. The successful L7 gun has been fitted on many armored vehicles including the British Centurion (starting from the Mk. 5/2 variant), the German Leopard 1 and early variants of the US M1 Abrams (M1 and M1IP). The L7 is a popular weapon and continued in use even after it was superseded by the L11 series 120 mm rifled tank gun, for some Centurion tanks operating as Artillery Forward Observation and Armoured Vehicle, Royal Engineers (AVRE) vehicles. The L7, and adaptations of it, can be found as standard or retrofitted equipment on a wide variety of tanks developed during the Cold War.
  • 6.7K
  • 08 Nov 2022
Topic Review
Word Lists by Frequency
Word lists by frequency are lists of a language's words grouped by frequency of occurrence within some given text corpus, either by levels or as a ranked list, serving the purpose of vocabulary acquisition. A word list by frequency "provides a rational basis for making sure that learners get the best return for their vocabulary learning effort" (Nation 1997), but is mainly intended for course writers, not directly for learners. Frequency lists are also made for lexicographical purposes, serving as a sort of checklist to ensure that common words are not left out. Some major pitfalls are the corpus content, the corpus register, and the definition of "word". While word counting is a thousand years old, with still gigantic analysis done by hand in the mid-20th century, natural language electronic processing of large corpora such as movie subtitles (SUBTLEX megastudy) has accelerated the research field. In computational linguistics, a frequency list is a sorted list of words (word types) together with their frequency, where frequency here usually means the number of occurrences in a given corpus, from which the rank can be derived as the position in the list.
  • 6.7K
  • 29 Nov 2022
Topic Review
Supercritical Water Gasification (SCWG)
Gasification with supercritical water (SCWG) is a thermochemical process which, exploiting the properties of supercritical water (374.1 °C and 22.1 MPa ), allows to obtain a syngas rich in hydrogen. Both biomass and waste plastic can be used as feedstock.
  • 6.7K
  • 18 Sep 2020
Topic Review Peer Reviewed
Domestic Environmental Experience Design
The term 'domestic environmental experience' was defined as users' experiences of cognitive perceptions and physical responses to their domestic built environments. Domestic environments can be enriched through the implementation of environmental experience design (EXD) by combining users' environmental, spatial and contextual factors that may accommodate occupants' needs and demands as well as their health and wellbeing. Here, an EXD theoretical concept has been developed based on the 'User-Centred Design' thematical framework.
  • 6.7K
  • 13 Apr 2022
Topic Review
Frost Diagram
A Frost diagram or Frost–Ebsworth diagram is a type of graph used by inorganic chemists in electrochemistry to illustrate the relative stability of a number of different oxidation states of a particular substance. The graph illustrates the free energy vs oxidation state of a chemical species. This effect is dependent on pH, so this parameter also must be included. The free energy is determined by the oxidation–reduction half-reactions. The Frost diagram allows easier comprehension of these reduction potentials than the earlier-designed Latimer diagram, because the “lack of additivity of potentials” was confusing. The free energy ΔG° is related to reduction potential E in the graph by given formula: ΔG° = −nFE° or nE° = −ΔG°/F, where n is the number of transferred electrons, and F is Faraday constant (F = 96,485 J/(V·mol)). The Frost diagram is named after Arthur Atwater Frost (de), who originally created it as a way to "show both free energy and oxidation potential data conveniently" in a 1951 paper.
  • 6.7K
  • 01 Dec 2022
Topic Review
Buddhist Ethics
Buddhist ethics are traditionally based on what Buddhists view as the enlightened perspective of the Buddha, or other enlightened beings such as Bodhisattvas. The Indian term for ethics or morality used in Buddhism is Śīla or sīla (Pāli). Śīla in Buddhism is one of three sections of the Noble Eightfold Path, and is a code of conduct that embraces a commitment to harmony and self-restraint with the principal motivation being nonviolence, or freedom from causing harm. It has been variously described as virtue, moral discipline and precept. Sīla is an internal, aware, and intentional ethical behavior, according to one's commitment to the path of liberation. It is an ethical compass within self and relationships, rather than what is associated with the English word "morality" (i.e., obedience, a sense of obligation, and external constraint). Sīla is one of the three practices foundational to Buddhism and the non-sectarian Vipassana movement — sīla, samādhi, and paññā as well as the Theravadin foundations of sīla, Dāna, and Bhavana. It is also the second pāramitā. Sīla is also wholehearted commitment to what is wholesome. Two aspects of sīla are essential to the training: right "performance" (caritta), and right "avoidance" (varitta). Honoring the precepts of sīla is considered a "great gift" (mahadana) to others, because it creates an atmosphere of trust, respect, and security. It means the practitioner poses no threat to another person's life, property, family, rights, or well-being. Moral instructions are included in Buddhist scriptures or handed down through tradition. Most scholars of Buddhist ethics thus rely on the examination of Buddhist scriptures, and the use of anthropological evidence from traditional Buddhist societies, to justify claims about the nature of Buddhist ethics.
  • 6.7K
  • 27 Nov 2022
Topic Review
Amen
Amen (/ˌɑːˈmɛn/, /ˌeɪˈmɛn/)[lower-alpha 1] (Hebrew אָמֵן, Greek ἀμήν, Arabic آمِينَ, Amharic አሜን) is a declaration of affirmation first found in the Hebrew Bible and subsequently in the New Testament. It is used in Jewish, Christian and Muslim worship as a concluding word or response to prayers. Common English translations of the word amen include "verily", "truly", and “so be it”. It can also be used colloquially to express strong agreement, as in, amen to that.
  • 6.7K
  • 27 Oct 2022
Topic Review
Support Needs in Intellectual Disability
“Support needs” is a psychological construct referring to the pattern and intensity of supports necessary for a person to participate in activities linked with normative human functioning.
  • 6.7K
  • 11 Jan 2021
Topic Review
Iridology
Iridology (also known as iridodiagnosis or iridiagnosis) is an alternative medicine technique whose proponents claim that patterns, colors, and other characteristics of the iris can be examined to determine information about a patient's systemic health. Practitioners match their observations to iris charts, which divide the iris into zones that correspond to specific parts of the human body. Iridologists see the eyes as "windows" into the body's state of health. Iridologists claim they can use the charts to distinguish between healthy systems and organs in the body and those that are overactive, inflamed, or distressed. Iridologists claim this information demonstrates a patient's susceptibility towards certain illnesses, reflects past medical problems, or predicts later health problems. As opposed to evidence-based medicine, iridology is not supported by quality research studies and is widely considered pseudoscience. The features of the iris are one of the most stable features on the human body throughout life. The stability of iris structures is the foundation of the biometric technology which uses iris recognition for identification purposes. In 1979, Bernard Jensen, a leading American iridologist, and two other iridology proponents failed to establish the basis of their practice when they examined photographs of the eyes of 143 patients in an attempt to determine which ones had kidney impairments. Of the patients, forty-eight had been diagnosed with kidney disease, and the rest had normal kidney function. Based on their analysis of the patients' irises, the three iridologists could not detect which patients had kidney disease and which did not.
  • 6.7K
  • 04 Nov 2022
Topic Review
Role of Chloroplast Gene Expression
 Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment. Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent.
  • 6.7K
  • 02 Sep 2020
Topic Review
Convolutional Neural Network in the Medical Imaging
Convolutional Neural Networks (CNN), commonly known as ConvNet, is one of the common types of Artificial Neural Network (ANN) that comes under the supervised method category. This method is known for its ability to discover and interpret patterns. This pattern detection brings up the usefulness of CNN for image analysis. 
  • 6.7K
  • 10 Apr 2023
Topic Review Peer Reviewed
Teachers’ Professional Digital Competence
Teachers’ professional digital competence (PDC) refers to digital competence specific to the teaching profession. PDC serves a dual purpose: it encompasses a range of instrumental, professional, ethical, critical, and epistemic dimensions related to, on the one hand, teaching with digital tools and resources and, on the other hand, teaching pupils about digital technologies, digital skills, digital cultural expression, and broader digital and critical competences relevant to study, work, and everyday life. Teachers’ PDC is a dynamic concept that evolves in step with societal development and technological advancement.
  • 6.7K
  • 17 Sep 2025
Topic Review
76 Mm Gun M1
The 76 mm gun M1 was an American World War II–era tank gun developed by the U.S Ordnance Department in 1942 to supplement the 75 mm gun on the basic Medium tank M4. It was also used to arm the 76 mm Gun Motor Carriage M18 tank destroyer. Although the gun was tested in early August 1942 and classified on August 17, 1942, it was not until August 1943 that the Ordnance Department developed a mounting for the M4 tank that the tank forces would accept. It was not accepted for combat until July 1944. In January 1943, the decision was made to mount the 76 mm on the vehicle that would become the M18. By May 1944, it was being combat tested as the T70.
  • 6.7K
  • 11 Nov 2022
Topic Review
Citrus limon (Lemon) Phenomenon
Citrus limon (lemon) is a species with valuable pharmaceutical, cosmetic and culinary (healthy food) properties. The valuable biological activity of C. limon is determined by its high content of phenolic compounds, mainly flavonoids (e.g., diosmin, hesperidin, limocitrin) and phenolic acids (e.g., ferulic, synapic, p-hydroxybenzoic acids). The essential oil is rich in bioactive monoterpenoids such as D-limonene, β-pinene, γ-terpinene. Recently scientifically proven therapeutic activities of C. limon include anti-inflammatory, antimicrobial, anticancer and antiparasitic activities. In view of beneficial properties C. limon  is also used in the food industry and cosmetology. Attention should be pay on safety of use and potential phototoxicity of this raw materials.
  • 6.7K
  • 30 Oct 2020
Topic Review
Nanolubricants
Nanolubricants are the name given to the dispersion of nanoparticles in a base oil, and has attracted researchers due to its potential application. In addition to being used in the tribology field, nanoparticles are also used for medical, space, and composites purposes. The addition of nanoparticles in base oils is promising because it enhances specific tribological characteristics including wear-resistance and friction, and the most important reason is that the majority of them are environmentally friendly. 
  • 6.7K
  • 17 Nov 2020
Topic Review
Cocoa By-Products
Theobroma cacao L., the cocoa-producing tree, belongs to the order of Malvales, family Malvaceae and genus Theobroma. Its name has Greek origins, Theos and Bromos, meaning “food of the gods”.
  • 6.7K
  • 19 Apr 2022
Topic Review
Varna Necropolis
The so-called Varna Necropolis (Bulgarian: Варненски некропол) (also Varna Cemetery) is a burial site from 4569–4340 BC in the western industrial zone of Varna (approximately half a kilometre from Lake Varna and 4 km from the city centre), internationally considered one of the key archaeological sites in world prehistory. There were other necropoles dating from later Greek and Roman periods around the ancient city. The oldest gold treasure in the world, dating from this period, was discovered at the site.
  • 6.7K
  • 28 Oct 2022
Topic Review
Graphical Projection
Graphical projection is a protocol, used in technical drawing, by which an image of a three-dimensional object is projected onto a planar surface without the aid of numerical calculation.
  • 6.7K
  • 07 Nov 2022
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