Your browser does not fully support modern features. Please upgrade for a smoother experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Electric Organ
In biology, the electric organ is an organ common to all electric fish used for the purposes of creating an electric field. The electric organ is derived from modified nerve or muscle tissue. The electric discharge from this organ is used for navigation, communication, mating, defense and also sometimes for the incapacitation of prey.
  • 4.3K
  • 29 Sep 2022
Topic Review
Permanent Magnet Machines for High-Speed Applications
High-speed electrical machines have been extensively researched in the last few decades for industrial and domestic applications, including compressors, vacuum pumps, turbine generators, machine tools, flywheel energy storages, and so on. Compared with low-speed and moderate-speed conventional electrical machines, high-speed electrical machines offer advantages such as high-power density, small size, and light weight. More importantly, high-speed electrical machines can be directly connected to high-speed loads, and conventional gear boxes are no longer needed, which avoids complex gear box systems, improves system efficiency and reliability, and reduces system vibration, noise, and cost. With the evolution in the field of power electronics converters, the problems of high frequency supplies, required for high-speed operation, is no longer a restriction. The development of high-speed electrical machines is also supported by the development of high-speed bearing systems with high robustness, fewer losses, and longer lifetime.
  • 4.3K
  • 17 Jan 2022
Topic Review
Clear-channel station
A clear-channel station is an AM radio station in North America that has the highest protection from interference from other stations, particularly concerning night-time skywave propagation. The system exists to ensure the viability of cross-country or cross-continent radio service, and is enforced through a series of treaties and statutory laws. Now known as Class A stations since 1982, they are occasionally still referred to by their former classifications of Class I-A (the highest classification), Class I-B (the next highest class), or Class I-N (for stations in Alaska too far away to cause interference to the primary clear-channel stations in the lower 48 states). The term "clear-channel" is used most often in the context of North America and the Caribbean, where the concept originated. Since 1941, these stations have been required to maintain at least 10,000 watts of power to retain their status. Nearly all these stations in the United States , Canada and The Bahamas broadcast at 50,000 watts, with several clear-channel stations in Mexico going as high as 150,000 watts and XEW in Mexico City operating at 250,000 watts for over 80 years. (Cuba was originally included in the plan and had several stations given clear-channel status, but Cuba stopped participating after 1959.)
  • 4.3K
  • 08 Oct 2022
Topic Review
Peptide/Protein Self-Assembly and Aggregation
The self-assembly of proteins is an essential process for a variety of cellular functions including cell respiration, mobility and division. On the other hand, protein or peptide misfolding and aggregation is related to the development of Parkinson’s disease and Alzheimer’s disease, among other aggregopathies.
  • 4.3K
  • 11 Nov 2020
Topic Review
Agricultural Extension for Smallholder Farmers
The creation of commercialization opportunities for smallholder farmers has taken primacy on the development agenda of many developing countries. Invariably, most of the smallholders are less productive than commercial farmers and continue to lag in commercialization. Apart from the various multifaceted challenges which smallholder farmers face, limited access to agricultural extension services stands as the underlying constraint to their sustainability. 
  • 4.3K
  • 02 Jul 2021
Topic Review
Total Petroleum Hydrocarbons in Seawater
Total Petroleum Hydrocarbons (TPH) is a term used to represent petroleum (crude oil) that consists of a blend of thousands of compounds. They are referred to as hydrocarbons because almost all consist of hydrogen and carbon. A crude oil spill is a common issue during offshore oil drilling, transport and transfer to onshore. Second, the production of petroleum refinery effluent is known to cause pollution due to its toxic effluent discharge. Sea habitats and onshore soil biota are affected by TPH as a pollutant in their natural environment. Crude oil pollution in seawater, estuaries and beaches requires an efficient process of cleaning. To remove crude oil pollutants from seawater, various physico-chemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi and algae has recently gained a lot of attention due to its efficiency and lower cost.
  • 4.3K
  • 23 Apr 2021
Topic Review
Scopes Trial
The Scopes Trial, formally known as The State of Tennessee v. John Thomas Scopes and commonly referred to as the Scopes Monkey Trial, was an American legal case in July 1925 in which a substitute high school teacher, John T. Scopes, was accused of violating Tennessee 's Butler Act, which had made it unlawful to teach human evolution in any state-funded school. The trial was deliberately staged in order to attract publicity to the small town of Dayton, Tennessee, where it was held. Scopes was unsure whether he had ever actually taught evolution, but he purposely incriminated himself so that the case could have a defendant. Scopes was found guilty and fined $100 (equivalent to $1458 in 2019), but the verdict was overturned on a technicality. The trial served its purpose of drawing intense national publicity, as national reporters flocked to Dayton to cover the big-name lawyers who had agreed to represent each side. William Jennings Bryan, three-time presidential candidate, argued for the prosecution, while Clarence Darrow, the famed defense attorney, spoke for Scopes. The trial publicized the Fundamentalist–Modernist Controversy, which set Modernists, who said evolution was not inconsistent with religion, against Fundamentalists, who said the word of God as revealed in the Bible took priority over all human knowledge. The case was thus seen as both a theological contest and a trial on whether "modern science" should be taught in schools.
  • 4.3K
  • 15 Nov 2022
Topic Review
Determinants of NRLAIS in Ethiopia
Ethiopia has embarked on one of the largest digitalization programs for rural land registration in Africa. The program is called the national rural land administration information system (NRLAIS). NRLAIS utilizes a modular technology stack with web-based approach and Land Administration Domain Model (LADM) for rural land registration. NRLAIS considered the functional and legal requirements at four government organizational structures (federal, regional, zonal, and woreda).
  • 4.3K
  • 23 Dec 2021
Topic Review
Zinc Complexes as Anticancer Agents
The search for anticancer metal-based drugs alternative to platinum derivatives could not exclude zinc derivatives due to the importance of this metal for the correct functioning of the human body. Zinc, the second most abundant trace element in the human body, is one of the most important micro-elements essential for human physiology. Its ubiquity in thousands of proteins and enzymes is related to its chemical features, in particular, its lack of redox activity and its ability to support different coordination geometries and to promote fast ligands exchange. Analogously to other trace elements, the impairment of its homeostasis can lead to various diseases and in some cases can be also related to cancer development. However, zinc complexes generally exert lower toxicity in comparison to other metal-based drugs and many zinc derivatives have been proposed as antitumor agents. Among them zinc complexes  comprising  N-donor ligands have been surveyed and analyzed. 
  • 4.3K
  • 22 Dec 2020
Topic Review Peer Reviewed
Active Edible Packaging
Active edible packaging is a food packaging made of comestible bioproducts and active compounds that interacts with the food. The bioproducts, usually biopolymers, must be recognized as safe and with characteristics to be consumed by humans—comestible—and not toxic and capable of carrying an active compound, like anti-browning agents, colorants, flavors, nutrients, antimicrobial and/or antioxidant compounds, in order to extend the product shelf-life, reduce contamination and maintain or even enhance the nutritional value.
  • 4.3K
  • 13 Apr 2022
Topic Review Video Peer Reviewed
Deep Meaningful Learning
Deep meaningful learning is the higher-order thinking and development through manifold active intellectual engagement aiming at meaning construction through pattern recognition and concept association. It includes inquiry, critical thinking, creative thinking, problem-solving, and metacognitive skills. It is a theory with a long academic record that can accommodate the demand for excellence in teaching and learning at all levels of education. Its achievement is verified through knowledge application in authentic contexts. 
  • 4.3K
  • 13 Apr 2022
Topic Review
Cotton Production in Pakistan
Cotton production in Pakistan is integral to the economic development of the country. The nation is largely dependent on the cotton industry and its related textile sector, and the crop has been given a principal status in the country. Cotton is grown as an industrial crop in 15% of the nation's land during the monsoon months of May to August, known as the kharif period, and is grown at a smaller scale between February and April. Record production of cotton was reported at 15 million bales of 470 pounds (210 kg) each in the form of phutti (seed cotton) during 2014–15, which was an 11% rise compared to the previous season (2013–14). Production-wise, as of 2012–13, Pakistan occupied the fourth position among the cotton growers of the world, the first three being China, India and the United States, in that order. In respect of exports of raw cotton, Pakistan holds third position, and is the fourth in consumption (about 30 and 40 per cent of its production). It is the largest exporter of cotton yarn.
  • 4.3K
  • 16 Nov 2022
Topic Review
Taurine, Bile Acids, and Microbiota
Taurine is the most abundant free amino acid in the body, and is mainly derived from the diet, but can also be produced endogenously from cysteine. It plays multiple essential roles in the body, including development, energy production, osmoregulation, prevention of oxidative stress, and inflammation. Taurine is also crucial as a molecule used to conjugate bile acids (BAs). In the gastrointestinal tract, BAs deconjugation by enteric bacteria results in high levels of unconjugated BAs and free taurine. Depending on conjugation status and other bacterial modifications, BAs constitute a pool of related but highly diverse molecules, each with different properties concerning solubility and toxicity, capacity to activate or inhibit receptors of BAs, and direct and indirect impact on microbiota and the host, whereas free taurine has a largely protective impact on the host, serves as a source of energy for microbiota, regulates bacterial colonization and defends from pathogens.
  • 4.3K
  • 19 Aug 2022
Topic Review
DNA-Based Methods in Identification of Fish Species
Various methods, differing in their principle and detected target molecules, can be used for fish species identification and adulteration detection. Parvalbumin detection has been preferred, but this is quite demanding compared to other food allergens because of its high biochemical and immunological variability among fish species and differing thermostability. This in itself sidelines the use of some types of methods, e.g., proteomic ones, and favors DNA-based methods, whose target, DNA, is not destroyed by the processing. Using DNA analysis, for example, a common form of adulteration—replacing the species (a more expensive one with a cheaper one)—can be detected. Additionally, DNA-based methods have the potential to detect the consumer being misled about the fish’s origin, another common type of adulteration. This is even more relevant, since genetically modified (GM) fish can be bought on the world market. Even though GM organisms do not pose a threat to public health and their quality is no different, consumers should be informed about the content of GM products, and because the public can be skeptical about GM products, sellers may want to hide this information and deliberately deceive the consumer.
  • 4.3K
  • 20 Feb 2023
Topic Review
Solar Energy in Argentina
A large gap exists between Argentina’s potential for solar energy utilization and the current solar energy deployment, despite advantages such as a high solar and land resources. This gap is, however, not static: different legal frameworks and governmental promotion programs have led to the deployment of large-scale and distributed off-grid photovoltaic installations, but they are at a volume (in terms of installed capacity) that lags years behind other countries with which Argentina shares relevant characteristics. For example, renewable energies Law 27424 and its implementations through the RenovAR promotion programs for RE led to a promising initial PV deployment, which nevertheless stagnated.
  • 4.3K
  • 15 Apr 2022
Biography
Mani Lal Bhaumik
Mani Lal Bhaumik is an Indian-born American physicist and a bestselling author.[1] Bhaumik was born on March 30, 1931 in a small village in Siuri, Medinipore, West Bengal, India and attended the Krishnagang krishi silpa vidyalaya school.[2][3] As a teenager, Bhaumik spent some time with Mahatma Gandhi in his Mahisadal camp. He received a Bachelor of Science degree from Scottish Church College
  • 4.3K
  • 22 Nov 2022
Topic Review
Kerala School of Astronomy and Mathematics
The Kerala School of Astronomy and Mathematics was a school of mathematics and astronomy founded by Madhava of Sangamagrama in Kerala, India, which included among its members: Parameshvara, Neelakanta Somayaji, Jyeshtadeva, Achyuta Pisharati, Melpathur Narayana Bhattathiri and Achyuta Panikkar. The school flourished between the 14th and 16th centuries and the original discoveries of the school seems to have ended with Narayana Bhattathiri (1559–1632). In attempting to solve astronomical problems, the Kerala school independently discovered a number of important mathematical concepts. Their most important results—series expansion for trigonometric functions—were described in Sanskrit verse in a book by Neelakanta called Tantrasangraha, and again in a commentary on this work, called Tantrasangraha-vakhya, of unknown authorship. The theorems were stated without proof, but proofs for the series for sine, cosine, and inverse tangent were provided a century later in the work Yuktibhasa (c. 1500 – c. 1610), written in Malayalam, by Jyesthadeva, and also in a commentary on Tantrasangraha. Their work, completed two centuries before the invention of calculus in Europe, provided what is now considered the first example of a power series (apart from geometric series). However, they did not formulate a systematic theory of differentiation and integration, nor is there any direct evidence of their results being transmitted outside Kerala.
  • 4.3K
  • 07 Oct 2022
Topic Review
Gowind-Class Corvette
The Gowind design is a family of steel monohull corvettes developed since 2006 by France 's Naval Group, formerly known as DCNS, to conduct missions in littoral zone such as anti-submarine warfare (ASW). The Gowind family includes vessels with lengths from 85 m to 102 m and displacement from 1,000 t to 2,500 t. The Gowind design can deploy Unmanned Aerial Vehicles (UAVs), Unmanned Surface Vehicles (USVs) and Underwater Unmanned Vehicles (UUVs). An aft deck has been provided allowing for a 10-ton class helicopter or Unmanned Aerial Vehicle (UAV) operations. The platform's weapon system consists of a multi-functional radar and MICA SAM. It is armed with Exocet anti ship missiles. The propulsion system is based on Combined Diesel and Diesel (CODAD) and includes water-jets for improved maneuverability in shallow waters and high-speed performance. There is no funnel (smokestack) on these ships. The radar and other sensors are mounted on a single central mast thus allowing 360-degree view. Naval Group offers two variants of the design: Gowind 1000 and Gowind 2500.
  • 4.3K
  • 02 Dec 2022
Topic Review
Empowerment
Empowerment is the degree of autonomy and self-determination in people and in communities. This enables them to represent their interests in a responsible and self-determined way, acting on their own authority. It is the process of becoming stronger and more confident, especially in controlling one's life and claiming one's rights. Empowerment as action refers both to the process of self-empowerment and to professional support of people, which enables them to overcome their sense of powerlessness and lack of influence, and to recognize and use their resources. As a term, empowerment originates from American community psychology and is associated with the social scientist Julian Rappaport (1981). However, the roots of empowerment theory extend further into history and are linked to Marxist sociological theory. These sociological ideas have continued to be developed and refined through Neo-Marxist Theory (also known as Critical Theory). In social work, empowerment forms a practical approach of resource-oriented intervention. In the field of citizenship education and democratic education, empowerment is seen as a tool to increase the responsibility of the citizen. Empowerment is a key concept in the discourse on promoting civic engagement. Empowerment as a concept, which is characterized by a move away from a deficit-oriented towards a more strength-oriented perception, can increasingly be found in management concepts, as well as in the areas of continuing education and self-help.
  • 4.3K
  • 15 Nov 2022
Topic Review
Effects of Chemical Fertilizer Combined with Organic Fertilizer
Chemical fertilizer has been excessively used for high yield of citrus around the world, especially in China; meanwhile, it deteriorates the citrus orchard soil environment. To resolve the conflict, the use of organic fertilizer provides a promising solution. This entry is to evaluate the effect of organic fertilizer on citrus yield, growth, soil properties etc. when nutrients of fertilizer of each treatment were equal except CK. 
  • 4.3K
  • 22 Mar 2022
  • Page
  • of
  • 2850
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback