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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
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
African Civet
The African Civet (Civettictis civetta) is a nocturnal mammal native to sub-Saharan Africa, recognized for its distinctive appearance and unique musk-producing glands. Characterized by its elongated body, short legs, and black-and-white spotted fur, the African Civet inhabits a variety of habitats including forests, savannas, and grasslands. As an omnivorous scavenger, it plays a vital ecological role in maintaining ecosystem balance by feeding on a diverse range of prey, including insects, small mammals, fruits, and carrion.
  • 5.3K
  • 28 Feb 2024
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.
  • 5.3K
  • 15 Nov 2022
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".
  • 5.3K
  • 30 Sep 2022
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
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
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.
  • 5.3K
  • 07 Nov 2023
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
Plasma
Plasma (from grc πλάσμα (plásma) 'moldable substance') is one of the four fundamental states of matter. It contains a significant portion of charged particles – ions and/or electrons. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. It extends to the rarefied intracluster medium and possibly to intergalactic regions. Plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching. Depending on temperature and density, a certain amount of neutral particles may also be present, in which case plasma is called partially ionized. Neon signs and lightning are examples of partially ionized plasmas. Unlike the phase transitions between the other three states of matter, the transition to plasma is not well defined and is a matter of interpretation and context. Whether a given degree of ionization suffices to call a substance 'plasma' depends on the specific phenomenon being considered.
  • 5.3K
  • 25 Nov 2022
Topic Review
Packaging Materials for Postharvest Conservation of Table Grapes
Table grapes are one of the leading fruit species cultivated in several countries due to their distinguishing sensory and nutritional properties. However, grapes are a non-climacteric fruit with relatively low physiological activity after harvest, and they are highly perishable due to gray mold caused by Botrytis cinerea as well to mass loss, berry softening, color degradation, and dehydration and darkening of the stem. To avoid all these difficulties, several packaging materials are used during cold storage to keep table grapes fresh and healthy for consumers. Proper packaging and cold storage combined can extend the shelf life of high-quality bunches by protecting them from mechanical injuries and decays during transportation and storage.
  • 5.3K
  • 30 Jun 2023
Topic Review
Bahá'í Faith on Life after Death
The Bahá'í Faith affirms the prospect of life after death extensively while not defining everything about it. The soul on death is said to recognize the value of its deeds and begin a new phase of a conscious relationship with God though negative experiences are possible. Others have noted the religion's stances on the afterlife.
  • 5.3K
  • 22 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.
  • 5.3K
  • 17 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
Topic Review
Mechanism of Action of Thiazolidin-2,4-dione
The thiazolidin-2,4-dione (TZD) moiety plays a central role in the biological functioning of several essential molecules. The availability of substitutions at the third and fifth positions of the Thiazolidin-2,4-dione (TZD) scaffold makes it a highly utilized and versatile moiety that exhibits a wide range of biological activities.
  • 5.3K
  • 18 Oct 2022
Topic Review
Lane Detection and Tracking
Lane detection and tracking are the advanced key features of the advanced driver assistance system. Lane detection is the process of detecting white lines on the roads. Lane tracking is the process of assisting the vehicle to remain in the desired path, and it controls the motion model by using previously detected lane markers.
  • 5.3K
  • 25 Oct 2021
Topic Review
ISO 29110
ISO/IEC 29110: Systems and Software Life Cycle Profiles and Guidelines for Very Small Entities (VSEs) International Standards (IS) and Technical Reports (TR) are targeted at Very Small Entities (VSEs). A Very Small Entity (VSE) is an enterprise, an organization, a department or a project having up to 25 people. The ISO/IEC 29110 is a series of international standards and guides entitled "Systems and Software Engineering — Lifecycle Profiles for Very Small Entities (VSEs)". The standards and technical reports were developed by working group 24 (WG24) of sub-committee 7 (SC7) of Joint Technical Committee 1 (JTC1) of the International Organization for Standardization and the International Electrotechnical Commission. Industries around the world have agreed that there are certain ways of working that produce predictable results. Companies that agree to use these agreed methods and then to have their compliance measured are called ISO certificated. Some ISO-certificated organizations require that their vendors also be ISO certificated. The general standard for software development, ISO/IEC/IEEE 12207, is appropriate for medium and large software development efforts. Similarly, the general standard for system development, ISO/IEC/IEEE 15288, is appropriate for medium and large system development efforts. Systems, in the context of ISO/IEC 29110, are typically composed of hardware and software components. Things work differently in small organisations; ISO 29110 reflects that.
  • 5.3K
  • 07 Nov 2022
Topic Review Peer Reviewed
Geometric Design of Suburban Roundabouts
A modern roundabout is an intersection with a circulatory roadway at which the vehicle speed is low, and the traffic is continuous and circulating in one direction around the central island towards the exits at the approach legs. Modern roundabout design is an iterative process that is composed of the following steps: (1) the identification of the roundabout as the optimal traffic solution; (2) the definition of the number of lanes at the intersection based on the required capacity and the level of service; (3) the initial design of the roundabout geometry; (4) design vehicle swept path, the fastest path analysis, and visibility performance checks; and (5) detailed roundabout design if the results of the performance checks are in line with the design recommendations. Initial roundabout geometry design elements are not independent of each other; therefore, care must be taken to provide compatibility between them. An overview and a comparative analysis of the initial geometric design elements for suburban single-lane roundabouts defined in roundabout design guidelines and norms used in Croatia, Austria, France, the Netherlands, Germany, Serbia, and Switzerland is given in this entry.
  • 5.3K
  • 13 Apr 2022
Topic Review
Passive Constant Flow Regulators
Passive flow control regulators, also known as passive flow control or autoregulated or pressure-compensated valves, deliver, without external control and energy consumption, a constant flow rate regardless of pressure variations.
  • 5.3K
  • 22 Dec 2020
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
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