You're using an outdated browser. Please upgrade to a modern browser for the best 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
Negative and Positive Effects of Distance Education
Distance education is defined “as an education system based on the Internet and interactive technologies to enable teachers and students from different locations to meet in real time”.
  • 12.1K
  • 10 Oct 2023
Topic Review
Sierpinski Triangle
The Sierpinski triangle (also with the original orthography Sierpiński), also called the Sierpinski gasket or the Sierpinski Sieve, is a fractal and attractive fixed set with the overall shape of an equilateral triangle, subdivided recursively into smaller equilateral triangles. Originally constructed as a curve, this is one of the basic examples of self-similar sets, i.e., it is a mathematically generated pattern that is reproducible at any magnification or reduction. It is named after the Poland mathematician Wacław Sierpiński, but appeared as a decorative pattern many centuries before the work of Sierpiński.
  • 12.1K
  • 04 Nov 2022
Topic Review
Causes of Food Overconsumption
When people refer to food, overconsumption means overeating, and is the situation in which an individual consumes food above the body’s energy requirements in relation to energy expenditure, leading to excess fat in the body. When practiced constantly for long periods of time, and coupled with lack of physical activity, overeating is the principal cause of overweight and obesity in both adults and children. Another aspect of overconsumption is that it is mainly due to an excessive intake of free sugars, fat, animal products and alcohol. The factors that lead to overeating are multiple, and difficult to identify exactly, but they can be grouped in helpful categories: global factors, societal factors, educational factors, and individual factors.
  • 12.1K
  • 01 Aug 2022
Topic Review
Algal Food and Its Application in Food Industry
With the rapid development of the economy and productivity, an increasing number of citizens are not only concerned about the nutritional value of algae as a potential new food resource but are also, in particular, paying more attention to the safety of its consumption. Many studies and reports pointed out that analyzing and solving seaweed food safety issues requires holistic and systematic consideration. The three main factors that have been found to affect the food safety of algal are physical, chemical, and microbiological hazards. At the same time, although food safety awareness among food producers and consumers has increased, foodborne diseases caused by algal food safety incidents occur frequently. It threatens the health and lives of consumers and may cause irreversible harm if treatment is not done promptly. A series of studies have also proved the idea that microbial contamination of algae is the main cause of this problem. Therefore, the rapid and efficient detection of toxic and pathogenic microbial contamination in algal products is an urgent issue that needs to be addressed. At the same time, two other factors, such as physical and chemical hazards, cannot be ignored. The detection techniques are mainly focused on three major hazards in traditional methods. However, especially for food microorganisms, the use of traditional microbiological control techniques is time-consuming and has limitations in terms of accuracy. These two evaluations of microbial foodborne pathogens monitoring in the farm-to-table chain have shown more importance, especially during the COVID-19 pandemic. Meanwhile, there are also many new developments in the monitoring of heavy metals, algal toxins, and other pollutants. In the future, algal food safety risk assessment will not only focus on convenient, rapid, low-cost and high-accuracy detection but also be connected with some novel technologies, such as the Internet of Things (artificial intelligence, machine learning), biosensor, and molecular biology, to reach the purpose of simultaneous detection. 
  • 12.0K
  • 20 Oct 2022
Topic Review
Palm Kernel Cake for Poultry
Palm kernel cake (PKC), a by-product of oil extracted from palm nuts through expeller press or solvent extraction procedures is one of the highest quantities of locally available and potentially inexpensive agricultural products. PKC provides approximately 14–18% of crude protein (CP), 12–20% crude fiber (CF), 3–9% ether extract (EE), and different amounts of various minerals that feasible to be used as a partial substitute of soybean meal (SBM) and corn in poultry nutrition. Poultry’s digestibility is reported to be compromised due to the indigestion of the high fiber content, making PKC potentially low for poultry feeding. Nevertheless, solid-state fermentation (SSF) can be applied to improve the nutritional quality of PKC by improving the CP and reducing CF content. PKC also contains β-mannan polysaccharide, which works as a prebiotic.
  • 12.0K
  • 07 Mar 2021
Topic Review
Plasma technology water purification
Plasma technology water purification is a new water treatment technology developed according to the trend of industrial water use in the 21st century. It is effective, efficient, scalable, versatile and customizable. These technologies must be able to adapt to new contaminants, reduce energy consumption, maintain or improve the proportionality between power and flow, demonstrate various flow capacities, minimize the transformation of existing infrastructure, prepare for imminent regulations, and tailor chemistry to site-specific requirements. New methods of water treatment by plasma must have all the above-mentioned properties and pose the least risk to public health. NTAPPs and their chemical reactions release energy and reactive chemical species that can kill bacteria and microorganisms, resulting in the disinfection of water. The advantage of this technique is that it can be performed in ambient air under atmospheric pressure without a vacuum system. Furthermore, NTAPP does not involve chemical products such as Cl. NTAPP can be used for water treatment in three ways: via direct, indirect, and bubbling methods.
  • 12.0K
  • 10 Jun 2021
Topic Review
DeLorean DMC-12
The DeLorean DMC-12 (commonly referred to simply as "the DeLorean", as it was the only model ever produced by the company) is a sports car originally manufactured by John DeLorean's DeLorean Motor Company for the American market from 1981 to 1983. The car features gull-wing doors and an innovative fiberglass body structure with a steel backbone chassis, along with external brushed stainless-steel body panels. It became widely known and iconic for its appearance, and because a modified DMC-12 was immortalized as the DeLorean time machine in the Back to the Future media franchise. The first prototype appeared in October 1976. Production officially began in 1981 in Dunmurry, a suburb of southwest Belfast, Northern Ireland, where the first DMC-12 rolled off the production line on January 21. Over the course of production, several features of the car were changed, such as the hood style, wheels, and interior. About 9,000 DMC-12s were made before production halted in early 1983. The DMC-12 was the only model produced by the company, which was later liquidated as the US car market went through its largest slump since the 1930s. In 2007, about 6,500 DeLorean Motor cars were thought to still exist. In 1995, Stephen Wynne, a British entrepreneur from Liverpool, created a separate company based in Texas using the "DeLorean Motor Company" name. Wynne acquired the trademark on the stylized "DMC" logo shortly thereafter, along with the remaining parts inventory of the original DeLorean Motor Company. The company builds new cars at its suburban Humble, Texas location from new old stock (NOS) parts, original equipment manufacturer (OEM), and reproduction parts on a "made to order" basis using existing vehicle identification number (VIN) plates. On January 27, 2016, DMC in Texas announced that it planned to build about 300–325 replica 1982 DMC-12 cars, each projected to cost just under US$100,000.
  • 12.0K
  • 01 Dec 2022
Topic Review
Chemical Bonding of H2O
Water (H2O) is a simple triatomic bent molecule with C2v molecular symmetry and bond angle of 104.5° between the central oxygen atom and the hydrogen atoms. Despite being one of the simplest triatomic molecules, its chemical bonding scheme is nonetheless complex as many of its bonding properties such as bond angle, ionization energy, and electronic state energy cannot be explained by one unified bonding model. Instead, several traditional and advanced bonding models such as simple Lewis and VESPR structure, valence bond theory, molecular orbital theory, isovalent hybridization, and Bent's rule are discussed below to provide a comprehensive bonding model for H2O, explaining and rationalizing the various electronic and physical properties and features manifested by its peculiar bonding arrangements.
  • 12.0K
  • 18 Oct 2022
Topic Review
Arduino
Arduino (/ɑːrˈdwiːnoʊ/) is an open-source hardware and software company, project, and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices. Its hardware products are licensed under a CC BY-SA license, while software is licensed under the GNU Lesser General Public License (LGPL) or the GNU General Public License (GPL), permitting the manufacture of Arduino boards and software distribution by anyone. Arduino boards are available commercially from the official website or through authorized distributors. Arduino board designs use a variety of microprocessors and controllers. The boards are equipped with sets of digital and analog input/output (I/O) pins that may be interfaced to various expansion boards ('shields') or breadboards (for prototyping) and other circuits. The boards feature serial communications interfaces, including Universal Serial Bus (USB) on some models, which are also used for loading programs. The microcontrollers can be programmed using the C and C++ programming languages, using a standard API which is also known as the Arduino language, inspired by the Processing language and used with a modified version of the Processing IDE. In addition to using traditional compiler toolchains, the Arduino project provides an integrated development environment (IDE) and a command line tool developed in Go. The Arduino project began in 2005 as a tool for students at the Interaction Design Institute Ivrea, Italy, aiming to provide a low-cost and easy way for novices and professionals to create devices that interact with their environment using sensors and actuators. Common examples of such devices intended for beginner hobbyists include simple robots, thermostats and motion detectors. The name Arduino comes from a bar in Ivrea, Italy, where some of the founders of the project used to meet. The bar was named after Arduin of Ivrea, who was the margrave of the March of Ivrea and King of Italy from 1002 to 1014.
  • 12.0K
  • 27 Oct 2022
Topic Review
Perceptual Organization
Gestalt theory has provided perceptual science with a conceptual framework relating to brain mechanisms that determine the way we see the visual world. This is referred to as "Perceptual Organization" and has inspired researchers in Psychology, Neuroscience and Computational Design ever since. The major Gestalt principles, such as the principle of Prägnanz, and more importantly the Gestalt laws of perceptual organization, have been critically important to our understanding of visual information processing, how the brain detects order in what we see, and derives likely perceptual representations from statistically significant structural regularities. The perceptual integration of contrast information across co-linear space for the organization of objects in the 2D image plane into figure and ground convey the most elementary basis to our understanding of the visual world. Gestalt theory continues to generate powerful concepts and insights for perceptual science even today, where it is to be placed in the context of image-base decision making by human minds and machines.
  • 12.0K
  • 22 Mar 2021
Topic Review
Fiber Crops
Fibers are everywhere around us and they are essential materials supporting our daily lives. Most fibers that we use in our daily activities are derived from fiber crops. In this entry, we introduce how fibers are classified, describe the main fiber crops in the world, and summarize their distributions and main usages by humans.
  • 11.9K
  • 01 Jul 2020
Topic Review
Extraction of Oil from Nigella sativa Seeds
Many extraction methods, such as cold pressing, supercritical fluid extraction, Soxhlet extraction, hydro distillation (HD) method, microwave-assisted extraction (MAE), ultrasound-assisted extraction, steam distillation, and accelerated solvent extraction (ASE) have been used to extract the oils from black seeds under optimal conditions. Black seed oil contains essential fatty acids, in which the major fatty acids are linoleic, oleic, and palmitic acids.
  • 11.9K
  • 21 Sep 2022
Topic Review
Starter Cultures in Foods
Starter cultures can be defined as preparations with a large number of cells that include a single type or a mixture of two or more microorganisms that are added to foods in order to take advantage of the compounds or products derived from their metabolism or enzymatic activity.
  • 11.9K
  • 19 Apr 2021
Topic Review
Law
Law is a system of rules that are created and enforced through social or governmental institutions to regulate behavior. Law is a system that regulates and ensures that individuals or a community adhere to the will of the state. State-enforced laws can be made by a collective legislature or by a single legislator, resulting in statutes, by the executive through decrees and regulations, or established by judges through precedent, normally in common law jurisdictions. Private individuals can create legally binding contracts, including arbitration agreements that may elect to accept alternative arbitration to the normal court process. The formation of laws themselves may be influenced by a constitution, written or tacit, and the rights encoded therein. The law shapes politics, economics, history and society in various ways and serves as a mediator of relations between people. A general distinction can be made between (a) civil law jurisdictions, in which a legislature or other central body codifies and consolidates their laws, and (b) common law systems, where judge-made precedent is accepted as binding law. Historically, religious laws played a significant role even in settling of secular matters, and is still used in some religious communities. Islamic Sharia law is the world's most widely used religious law, and is used as the primary legal system in some countries, such as Iran and Saudi Arabia. The adjudication of the law is generally divided into two main areas. Criminal law deals with conduct that is considered harmful to social order and in which the guilty party may be imprisoned or fined. Civil law (not to be confused with civil law jurisdictions above) deals with the resolution of lawsuits (disputes) between individuals or organizations. Law provides a source of scholarly inquiry into legal history, philosophy, economic analysis and sociology. Law also raises important and complex issues concerning equality, fairness, and justice.
  • 11.9K
  • 25 Oct 2022
Topic Review
Thermal Stability of Structural Materials
Thermal stability determines the material ability of retaining its properties at required temperatures over extended service time. In addition to temperature and time, thermal stability is affected by load conditions and environmental conditions.
  • 11.9K
  • 20 Aug 2020
Topic Review
Antenna Aperture
In electromagnetics and antenna theory, antenna aperture, effective area, or receiving cross section, is a measure of how effective an antenna is at receiving the power of electromagnetic radiation (such as radio waves). The aperture is defined as the area, oriented perpendicular to the direction of an incoming electromagnetic wave, which would intercept the same amount of power from that wave as is produced by the antenna receiving it. Assume a plane wave in a particular direction has an irradiance or power flux density [math]\displaystyle{ S }[/math]; this is the amount of power passing through a unit area of one square meter. Then if an antenna delivers [math]\displaystyle{ P_o }[/math] watts to the load connected to its output terminals (e.g. the receiver) when irradiated by a uniform field of power density [math]\displaystyle{ S }[/math] watts per square meter, the antenna's aperture for the direction of that plane wave is [math]\displaystyle{ A_e }[/math] in square meters, given by: So the power received by an antenna (in watts) is equal to the power density of the electromagnetic energy (in watts per square meter), multiplied by its aperture (in square meters). Radio waves from a direction where the antenna's aperture is larger thus collect a greater amount of that wave's power; this is more often referred to as antenna gain. To actually obtain that available power [math]\displaystyle{ P_o }[/math], the incoming radiation must be in the state of polarization specified for that antenna, and the load (receiver) must be impedance matched to the antenna's feedpoint impedance. The meaning of aperture is thus based on a receiving antenna, however any receiving antenna can also be used for transmission. Due to reciprocity, an antenna's gain in receiving and transmitting are identical, so the power transmitted by an antenna in different directions (the radiation pattern) is always proportional to the effective area [math]\displaystyle{ A_e }[/math] in each direction; that proportionality factor is derived below. When no direction is specified, [math]\displaystyle{ A_e }[/math] (or "antenna gain") is understood to refer to its maximum value, that is, in the intended direction(s) that the antenna is designed to receive from and/or transmit toward.
  • 11.9K
  • 27 Oct 2022
Topic Review
Second Language Acquisition
Second language acquisition, or SLA, is the process by which people learn languages in addition to their native tongue(s). The term second language is used to describe any language whose acquisition starts after early childhood (including what may be the third or subsequent language learned). The language to be learned is often referred to as the "target language" or "L2"; SLA is sometimes called L2A, for "L2 acquisition". The term "language acquisition" became commonly used after Stephen Krashen contrasted it with formal and non-constructive "learning." Today, most scholars use "language learning" and "language acquisition" interchangeably, unless they are directly addressing Krashen's work. However, "second language acquisition" or "SLA" has become established as the preferred term for this academic discipline. The study of SLA is usually viewed as part of applied linguistics.
  • 11.9K
  • 04 Nov 2022
Topic Review
9M133 Kornet
The 9M133 Kornet (Russian: Корнет; "Cornet", NATO reporting name AT-14 Spriggan, export designation Kornet-E) is a modern Russian man-portable anti-tank guided missile (ATGM) intended for use against main battle tanks. It was first introduced into service with the Russian army in 1998. The Kornet is among the most capable Russian ATGMs. It is not intended to fully replace previous systems, due to its high cost. The Kornet comes in variants with thermobaric warheads for use against soft targets. It was further developed into the 9M133 Kornet-EM, which has increased range, fire-and-forget capability, and an improved warhead. The Kornet has been widely exported and is produced under license in several countries. It was first used in combat in 2003 and has since been used in many conflicts. The NATO reporting name AT-14 Spriggan is derived from the spriggan, a legendary creature from Cornish faery lore.
  • 11.9K
  • 08 Nov 2022
Topic Review
Duchy
A duchy is a medieval country, territory, fief, or domain ruled by a duke or duchess, a high-ranking nobleman hierarchically second to the king or queen in European tradition. The term is used almost exclusively in Europe, where in the present day there is no sovereign duchy (i.e. with the status of a nation state) left. The term "duke" (like the corresponding "duchy") should not be confused with the title Grand Duke (or Grand Duchy, such as the present-day Grand Duchy of Luxembourg), as there exists a significant difference of rank between the two. In common European cultural heritage, a grand duke is the third highest monarchic rank, after emperor and king. Its synonym in many Slavic and Baltic European languages (Russian, Lithuanian, etc.) is translated as Grand Prince, whereas most Germanic and Romance European languages (English, French, Spanish, Italian etc.) use expressions corresponding to Grand Duke. Unlike a duke, the sovereign grand duke is considered royalty (or in German, 'royal nobility', Königsadel). The proper form of address for a grand duke is His Royal Highness (HRH), whereas for a non-royal duke in the United Kingdom it is His Grace. In contrast to this, the rank of a duke differs from one country to the next. In Germany, for example, a duke is listed in the aristocratic hierarchy below an emperor (Kaiser), king (König), grand duke (Großherzog), and elector (Kurfürst) – in that order – whereas in Britain the duke comes third after king/queen and prince (there are no British grand dukes or electors). In all countries, there existed an important difference between "sovereign dukes" and dukes subordinate to a king or emperor. Some historic duchies were sovereign in areas that would become part of nation-states only during the modern era, such as Germany (a federal empire) and Italy (a unified kingdom). In contrast, others were subordinate districts of those kingdoms that had unified either partially or completely during the medieval era, such as France, Spain, Sicily, Naples, and the Papal States. In England, the term is used in respect of non-territorial entities.
  • 11.9K
  • 09 Oct 2022
Topic Review
Cyclic Quadrilateral
In Euclidean geometry, a cyclic quadrilateral or inscribed quadrilateral is a quadrilateral whose vertices all lie on a single circle. This circle is called the circumcircle or circumscribed circle, and the vertices are said to be concyclic. The center of the circle and its radius are called the circumcenter and the circumradius respectively. Other names for these quadrilaterals are concyclic quadrilateral and chordal quadrilateral, the latter since the sides of the quadrilateral are chords of the circumcircle. Usually the quadrilateral is assumed to be convex, but there are also crossed cyclic quadrilaterals. The formulas and properties given below are valid in the convex case. The word cyclic is from the Ancient Greek κύκλος (kuklos) which means "circle" or "wheel". All triangles have a circumcircle, but not all quadrilaterals do. An example of a quadrilateral that cannot be cyclic is a non-square rhombus. The section characterizations below states what necessary and sufficient conditions a quadrilateral must satisfy to have a circumcircle.
  • 11.9K
  • 27 Oct 2022
  • Page
  • of
  • 2713
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback