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Topic Review
Paan
Paan (from Sanskrit: पर्ण, romanized: parṇá, lit. leaf, cognate with English fern) is a preparation combining betel leaf with areca nut widely consumed throughout South Asia and East Asia (mainly Taiwan). It is chewed for its stimulant effects. After chewing, it is either spat out or swallowed. Paan has many variations. Slaked lime (chuna) paste is commonly added to bind the leaves. Some preparations in the Indian subcontinent include katha paste or mukhwas to freshen the breath. Magahi paan is an expensive variety of betel which is grown in Aurangabad, Gaya and Nalanda districts of central Bihar. It is non-fibrous, sweeter, tastier and the softest of the lot. The origin and diffusion of betel chewing originates from and is closely tied to the Neolithic expansion of the Austronesian peoples. It was spread to the Indo-Pacific during prehistoric times, reaching Near Oceania at 3,400 to 3,000 BP; South India and Sri Lanka by 3,500 BP; Mainland Southeast Asia by 3,000 to 2,500 BP; Northern India by 1500 BP; and Madagascar by 600 BP. From India, it was also spread westwards to Persia and the Mediterranean. Paan (under a variety of names) is also consumed in many other Asian countries and elsewhere in the world by some Asian emigrants, with or without tobacco. It can be an addictive and stimulating formulation with adverse health effects, both with and without tobacco. The spit from chewing betel nuts, known as "buai pekpek" in Papua New Guinea, is often considered an eyesore. Because of this, many places have banned selling and chewing "buai".
  • 5.4K
  • 30 Sep 2022
Topic Review
Organosilicon
Organosilicon compounds are organometallic compounds containing carbon–silicon bonds. Organosilicon chemistry is the corresponding science of their preparation and properties. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an inorganic compound.
  • 5.4K
  • 04 Nov 2022
Topic Review
Amperometric Biosensors
Amperometric biosensors utilizing oxidoreductases were classified into three generations: 1st generation biosensors employing oxidases based on the electrocatalytic monitoring of substrate consumption or product formation, 2nd generation biosensors employing oxidases or dehydrogenases based on the electrocatalytic recycling of suitable redox mediators, and 3rd generation biosensors employing oxidoreductases capable of direct electron transfer to bare or modified electrodes.
  • 5.3K
  • 16 Aug 2021
Topic Review
The Related Metabolic Diseases and Treatments of Obesity
Obesity is a chronic disease characterized by the abnormal or excessive accumulation of body fat. Obesity is commonly associated with other metabolic disorders, such as type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular diseases, chronic kidney disease, and cancers. Factors such as a sedentary lifestyle, overnutrition, socioeconomic status, and other environmental and genetic conditions can cause obesity. Many molecules and signaling pathways are involved in the pathogenesis of obesity. 
  • 5.3K
  • 01 Sep 2022
Topic Review
Young Hegelians
The Young Hegelians (German: Junghegelianer), or Left Hegelians (Linkshegelianer), or the Hegelian Left (die Hegelsche Linke), were a group of German intellectuals who, in the decade or so after the death of Georg Wilhelm Friedrich Hegel in 1831, reacted to and wrote about his ambiguous legacy. The Young Hegelians drew on his idea that the purpose and promise of history was the total negation of everything conducive to restricting freedom and reason; and they proceeded to mount radical critiques, first of religion and then of the Prussian political system. They rejected anti-utopian aspects of his thought that "Old Hegelians" have interpreted to mean that the world has already essentially reached perfection.
  • 5.3K
  • 11 Nov 2022
Topic Review
Information Deficit Model
In studies of the public understanding of science, the information deficit model (or simply deficit model) or science literacy/knowledge deficit model attributes public scepticism or hostility to science and technology to a lack of understanding, resulting from a lack of information. It is associated with a division between experts who have the information and non-experts who do not. The model implies that communication should focus on improving the transfer of information from experts to non-experts.
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  • 17 Nov 2022
Topic Review
Penal Military Unit
Penal military units, including penal battalions, penal companies, etc., are military formations consisting of convicts mobilized for military service. Such formations may contain soldiers convicted of offenses under military law, persons enrolled in the unit after being convicted in civilian courts or some combination of the two. Service in such units is typically considered a form of punishment or discipline in lieu of imprisonment or capital punishment.
  • 5.3K
  • 02 Nov 2022
Topic Review
Metal–Organic Framework-Based Membranes for Gas Separation
Metal–organic frameworks (MOFs) represent the largest class of materials among crystalline porous materials ever developed, and have attracted attention as core materials for separation technology. Their extremely uniform pore aperture and nearly unlimited structural and chemical characteristics have attracted great interest and promise for applying MOFs to adsorptive and membrane-based separations. 
  • 5.3K
  • 28 Feb 2024
Topic Review
Nanocellulose
Nanocellulose can be used to improve the mechanical properties of cementitious materials if a proper dosage is used. Nanocellulose can be used as a type of viscosity-modifying agent (VMA) in cementitious materials. Nanocellulose with a proper dosage can reduce the shrinkage of cementitious materials, especially with a low water-to-cement (w/c) ratio. Four types of nanocelluloses, including cellulose nanocrystal, cellulose nanofibril, bacterial cellulose, and cellulose filament, have been used in cementitious materials.
  • 5.3K
  • 25 Dec 2020
Topic Review
Energy Use in Greenhouses in the EU
High energy systems, which are more dominant in northern Europe, are generally heavily climate controlled and energy use is dominated by heating and cooling processes, while low energy systems, which are dominant in southern Europe, show a mixture of energy uses including heating, cooling, irrigation, lighting, fertilisers, and pesticides.
  • 5.3K
  • 27 May 2022
Topic Review
Nanozymes
Nanozymes are advanced nanomaterials which possess unique physicochemical properties with the precise structural fabrication capability to mimic intrinsic biologically relevant reactions.
  • 5.3K
  • 19 Jan 2021
Topic Review
Serendipity as a strategic advantage
Serendipity is defined as an ability to notice, evaluate, and take advantage of unexpected information for survival purposes (both natural and social). Based on this definition, Nancy K. Napier and Vuong Quan Hoang propose a framework to develop the notion of serendipity as a strategic advantage (or competitive advantage), both in practice and in research.
  • 5.3K
  • 06 May 2024
Biography
Mario J. Molina
Mario José Molina-Pasquel Henríquez (born March 19, 1943) is a Mexican chemist. He played a pivotal role in the discovery of the Antarctic ozone hole, and was a co-recipient of the 1995 Nobel Prize in Chemistry for his role in elucidating the threat to the Earth's ozone layer of chlorofluorocarbon (CFC) gases. He became the first Mexican-born citizen to receive a Nobel Prize in Chemistry.[1]
  • 5.3K
  • 29 Nov 2022
Topic Review
Acid Rain
Acid rain has an acidity that is higher than that of normal rainwater. Normal rainwater is not neutral (which would be pH 7) but slightly acidic (it has a pH < 5.5), because some of the carbon dioxide CO2 dissolved in the water is present as carbonic acid H2CO3. In acid rain, chemicals from pollution and natural causes such as volcanic eruptions and emissions from vegetation increase the acidity of the water to as low as pH 4.4 to 4 (as measured in the 1990s in various places). Such acidic rainwater is dangerous for people, vegetation, water bodies including the oceans and its inhabitants, buildings and soil. Since the pH scale is logarithmic, a change from 5.5 to 4.5 means a tenfold increase in acidity. The three main pollutants that cause acid rain are the nitric oxides NO and NO2 (summarized as NOx) and sulfur dioxide SO2. These substances react with water to nitric acid HNO3 and sulfuric acid H2SO4. In the 1980s, in nearly all of Northern Europe and in the Northern United States, suddenly and unexpectedly, whole forests began to die (this effect got to be known as forest dieback). German forests especially experienced severe damage: from 8% in 1982 it increased to 50% in 1984, and stayed as such till 1987. The damage occurred amongst various tree species. Researchers established connections of this damage to acid rain. The mandatory installment of sulfur filters in coal power plants and of catalytic converters in cars in various industrialized countries reduced air pollution with the chemicals related to the formation of acid rain, and, although the forests are still not in perfect shape (about 20% are heavily impaired) a complete death was prevented.
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  • 15 Nov 2022
Topic Review
Universal Model of Cancer Transformation and Development
As a phenomenon, cancer is a disease related to multicellular evolution, i.e., cancer in general is understood to be a failure of the multicellular systems and is considered a reversal to unicellularity. Cancer cells are like unicellular organisms that benefit from ancestral-like traits. As a disease, cancer can be interpreted as (a) a destruction of cooperative behaviors underlying multicellular evolution, (b) a disruption of molecular networks established during the emergence of multicellularity or (c) an atavistic state resulting from reactivation of primitive programs typical of the earliest unicellular species. From this point of view and in accordance with the layered model of evolution of cellular functionalities, cancer transformation can occur as a result of huge disturbances or the destruction of functionalities that are located in the multicellular layer.
  • 5.3K
  • 06 May 2022
Topic Review
Mountain Man
A mountain man is an explorer who lives in the wilderness. Mountain men were most common in the North American Rocky Mountains from about 1810 through to the 1880s (with a peak population in the early 1840s). They were instrumental in opening up the various Emigrant Trails (widened into wagon roads) allowing Americans in the east to settle the new territories of the far west by organized wagon trains traveling over roads explored and in many cases, physically improved by the mountain men and the big fur companies originally to serve the mule train based inland fur trade. They arose in a natural geographic and economic expansion driven by the lucrative earnings available in the North American fur trade, in the wake of the various 1806–07 published accounts of the Lewis and Clark expeditions' (1803–1806) findings about the Rockies and the (ownership-disputed) Oregon Country where they flourished economically for over three decades. By the time two new international treaties in early 1846 and early 1848 officially settled new western coastal territories in the United States and spurred a large upsurge in migration, the days of mountain men making a good living by fur trapping had largely ended. This was partly because the fur industry was failing due to reduced demand and over trapping. With the rise of the silk trade and quick collapse of the North American beaver-based fur trade in the later 1830s–1840s, many of the mountain men settled into jobs as Army Scouts or wagon train guides or settled throughout the lands which they had helped open up. Others, like William Sublette, opened up fort-trading posts along the Oregon Trail to service the remnant fur trade and the settlers heading west.
  • 5.3K
  • 11 Nov 2022
Topic Review
Trends of Current LNG Cold Energy Utilization
Liquified natural gas (LNG) is a clean primary energy source that is growing in popularity due to the distance between natural gas (NG)-producing countries and importing countries. The large amount of cold energy stored in LNG presents an opportunity for sustainable technologies to recover and utilize this energy. This can enhance the energy efficiency of LNG regasification terminals and the economic viability of the LNG supply chain. The energy stored in LNG in the form of low temperatures is referred to as cold energy. When LNG is regasified, or converted back into its gaseous form, this cold energy is released. This process involves heating the LNG, which causes it to vaporize and release its stored energy. LNG cold energy has been mostly utilized for power generation, air separation, traditional desalination, and cryogenics carbon dioxide capture. Other potential applications are also emerging such as for data center cooling and cold energy storage. The commercialization of sustainable technologies, such as improvement strategies for LNG cold energy utilization, is becoming increasingly important in the energy industry.
  • 5.3K
  • 20 Feb 2023
Topic Review
Non-Medical Applications of Chitosan Nanocomposite Coatings
Millions of tons of crustaceans are produced every year and consumed as protein-rich seafood but the shells and other non-edible parts constituting about half the body mass are wasted. The crustacean shells are a prominent source of polysaccharide (chitin) and protein. Chitosan, a de-acetylated form of chitin obtained from the crustacean waste are used for a variety of medical applications. In recent times, it has also found use in food and paint industries including marine antifouling coatings, due to its characteristic properties, like solubility in weak acids, film-forming ability, pH-sensitivity, antifouling properties, biodegradability, and biocompatibility. Chitosan composite coatings in food, paint and water treatment solutions have been developed. In food industries, chitosan-based composite films and coatings are applied for prolonging the post-harvest life of fruits and vegetables, while anti-corrosion and self-healing properties are mainly explored for antifouling applications in paints and metal ion chelation and antifouling properties are useful for water treatment.
  • 5.3K
  • 29 Oct 2020
Topic Review
Proto-Romanian Language
Proto-Romanian (also known as "Common Romanian", româna comună or "Ancient Romanian", străromâna, Balkan Latin) is a hypothetical and unattested Romance language evolved from Vulgar Latin and considered to have been spoken by the ancestors of today's Romanians and related Balkan Latin peoples (Vlachs) before c. 900 (7th–11th century AD). In the 9th century Proto-Romanian already had a structure very distinct from the other Romance languages, with major differences in grammar, morphology and phonology and already was a member of the Balkan language area. Most of its features can be found in the modern Balkan Romance languages. It already contained around a hundred loans from Slavic languages, including words such as trup (body, flesh), as well as some Greek language loans via Vulgar Latin, but no Hungarian and Turkish words as these nations had yet to arrive in the region. According to the Romanian theory, it evolved into the following modern languages and their dialects: The first language that broke the unity was Aromanian, in the 9th century, followed shortly after by Megleno-Romanian. Istro-Romanian was the last to break the link with Daco-Romanian in the 11th century. The place where Proto-Romanian formed is still under debate; most historians put it just to the north of the Jireček Line. See: Origin of Romanians. The Roman occupation led to a Roman-Thracian syncretism, and similar to the case of other conquered civilisation (see Gallo-Roman culture developed in Roman Gaul), had as final result the Latinization of many Thracian tribes which were on the edge of the sphere of Latin influence, eventually resulting in the possible extinction of the Daco-Thracian language (unless, of course, Albanian is its descendant), but traces of it are still preserved in the Eastern Romance substratum. From the 2nd century AD, the Latin spoken in the Danubian provinces starts to display its own distinctive features, separate from the rest of the Romance languages, including those of western Balkans (Dalmatian). The Thraco-Roman period of the Romanian language is usually delimited between the 2nd century (or earlier via cultural influence and economic ties) and the 6th or the 7th century. It is divided, in turn, into two periods, with the division falling roughly in the 3rd to 4th century. The Romanian Academy considers the 5th century as the latest time that the differences between Balkan Latin and western Latin could have appeared, and that between the 5th and 8th centuries, the new language, Romanian, switched from Latin speech, to a vernacular Romance idiom, called Română comună.
  • 5.3K
  • 21 Nov 2022
Topic Review
Engine Control Unit
An engine control unit (ECU), also commonly called an engine control module (ECM) is a type of electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. It does this by reading values from a multitude of sensors within the engine bay, interpreting the data using multidimensional performance maps (called lookup tables), and adjusting the engine actuators. Before ECUs, air–fuel mixture, ignition timing, and idle speed were mechanically set and dynamically controlled by mechanical and pneumatic means. If the ECU has control over the fuel lines, then it is referred to as an electronic engine management system (EEMS). The fuel injection system has the major role of controlling the engine's fuel supply. The whole mechanism of the EEMS is controlled by a stack of sensors and actuators.
  • 5.3K
  • 14 Oct 2022
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