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Topic Review
Shrimp Farming in the Philippines
Aquaculture serves the employment and food security needs of most Asian coastal countries, such as Bangladesh, China, India, Indonesia, the Philippines, Thailand, and Vietnam, which are all aquaculture-reliant countries with large aquaculture sectors. Aquaculture is a major driver of socioeconomic development in poor rural and coastal communities, particularly in Asia, and it relieves the pressure on, and helps to maintain the sustainability of, wild-caught species from rivers, lakes, and oceans, as it provides for the shortfalls of capture fisheries.  This industry has become a major source of food protein and it is predicted that it will support the seafood production as a sustainable alternative to wild-caught fish.
  • 15.9K
  • 16 Mar 2022
Topic Review
Timoshenko-Ehrenfest Beam Theory
The Timoshenko-Ehrenfest beam theory was developed by Stephen Timoshenko and Paul Ehrenfest early in the 20th century. The model takes into account shear deformation and rotational bending effects, making it suitable for describing the behaviour of thick beams, sandwich composite beams, or beams subject to high-frequency excitation when the wavelength approaches the thickness of the beam. The resulting equation is of 4th order but, unlike Euler–Bernoulli beam theory, there is also a second-order partial derivative present. Physically, taking into account the added mechanisms of deformation effectively lowers the stiffness of the beam, while the result is a larger deflection under a static load and lower predicted eigenfrequencies for a given set of boundary conditions. The latter effect is more noticeable for higher frequencies as the wavelength becomes shorter (in principle comparable to the height of the beam or shorter), and thus the distance between opposing shear forces decreases. Rotary inertia effect was introduced by Bresse and Rayleigh. If the shear modulus of the beam material approaches infinity—and thus the beam becomes rigid in shear—and if rotational inertia effects are neglected, Timoshenko beam theory converges towards ordinary beam theory.
  • 15.9K
  • 20 Oct 2022
Topic Review
Two-Dimensional Materials
Two-dimensional (2D) materials are defined as crystalline materials consisting of single- or few-layer atoms, in which the in-plane interatomic interactions are much stronger than those along the stacking direction. Since the success of monolayer graphene exfoliation, 2D materials have been extensively studied due to their unique structures and unprecedented properties. Among these fascinating studies, the most predominant focus has been on their atomic structures, defects, and mechanical behaviors and properties, which serve as the basis for the practical applications of 2D materials.
  • 15.7K
  • 07 Jan 2022
Topic Review
Social Sciences and COVID-19
This entry seeks to provide an answer to the question of what is the relevance of Social Sciences for understanding the multiple implications and challenges posed by the COVID-19 contagion pandemic.
  • 15.7K
  • 16 Nov 2020
Topic Review
Moon Man (Internet Meme)
Mac Tonight is a fictional character used in the marketing for McDonald's restaurants during the mid-1980s. Known for his crescent moon head, sunglasses and piano-playing, the character used the song "Mack the Knife" which was made famous in the United States by Bobby Darin. Throughout the campaign, Mac was portrayed by actor Doug Jones in his fourth Hollywood job. Originally conceived as a promotion to increase dinner sales by Southern California licensees, Mac Tonight's popularity led McDonald's to take it nationwide in 1987. Although McDonald's ceased airing the commercials and retired the character after settling a lawsuit brought by Darin's estate in 1989, the company reintroduced the character nineteen years later throughout Southeast Asia in 2007.
  • 15.7K
  • 24 Nov 2022
Topic Review
Hydrogen Storage and Transportation
In the current hydrocarbon economy, transportation is fueled primarily by petroleum. Burning of hydrocarbon fuels emits carbon dioxide and other pollutants. The supply of economically usable hydrocarbon resources in the world is limited, and the demand of hydrocarbon fuels is increasing, particularly in China, India and other countries. Proponents of a world-scale hydrogen economy argue that hydrogen can be environmentally cleaner source of energy to end-users, particularly in transportation applications, without release of pollutants (such as particulate matter) or carbon dioxide at the point of end use. A recent analysis asserted that “most of the hydrogen supply chain pathways would release significantly less carbon dioxide into the atmosphere than would gasoline used in hybrid electric vehicles” and that significant reductions in carbon dioxide emissions would be possible if carbon capture or carbon sequestration methods were utilized at the site od energy or hydrogen production. Hydrogen storage can be distributed continuously in pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system also pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels. Furthermore, hydrogen is regenerative and environment friendly. But two difficulties with hydrogen are that hydrogen is just an energy carrier and has a low critical temperature of 35 K, i.e., hydrogen is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific surface area (at T< 100K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent and ionic compounds (at ambient pressure), oxidation of reactive metals e.g., Li, Na, Mg, Al, Zn with water. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can be thermally reduced to the metals in a solar furnace. In conclusion, routes for the transmission and storage of hydrogen for chemical processes, and hydrogen-based energy systems are increasing their establishment. Here, these routes are described, considering their attractions and difficulties.
  • 15.6K
  • 18 Jun 2021
Topic Review
BMW 5 Series (E39)
The BMW E39 is the fourth generation of BMW 5 Series, which was sold from 1995 to 2004. It was launched in the sedan body style, with the wagon/estate body style (marketed as "Touring") introduced in 1996. The E39 was replaced by the E60 5 Series in 2003, however E39 Touring models remained in production until May 2004. The proportion of chassis components using aluminium significantly increased for the E39, and it was the first 5 Series to use aluminium for all major components in the front suspension or any in the rear. It was also the first 5 Series where a four-cylinder diesel engine was available. Rack and pinion steering was used for the first time in a 5 Series (with the exception of the E34 525iX), being fitted to the four-cylinder and six-cylinder models. Unlike its E34 predecessor and E60 successor, the E39 was not available with all-wheel drive. The high performance M5 sedan was introduced in 1998, powered by the 4.9-litre S62 V8 engine. It was the first M5 model to be powered by a V8 engine.
  • 15.6K
  • 05 Dec 2022
Topic Review
Palm Wine
The reference to palm wine as a drink with many functionalities has increased over the years. However, few empirical tests have been carried out on humans to substantiate the claims. This perspective looks at the biochemical and microbiological reports on palm wine to highlight the constituents that are associated with functional beverages. Based on the constituents of the drink, it may qualify as a multifunctional beverage because several investigators have demonstrated disease risk reduction, improved nutrition and health outcomes in many studies, albeit in rats rather than humans. The constituents found in functional beverages are present in the drink. However, when assessed under European Union regulations, fermented palm wine (from 3% alcohol) cannot be regarded as a functional beverage because beverages that contain over 1.2% alcohol cannot be approved for any claim on health or nutritional benefit. The fresh sap with much lower alcohol may be suitable after it is refined and subjected to scientific examination to determine quantities of the drink that can confer health benefits on humans.
  • 15.5K
  • 10 Aug 2021
Topic Review
Guilt-shame-fear Spectrum of Cultures
In cultural anthropology, the distinction between a guilt society (or guilt culture), shame society (also shame culture or honor-shame culture), and a fear society (or culture of fear) has been used to categorize different cultures. The differences can apply to how behavior is governed with respect to government laws, business rules, or social etiquette. This classification has been applied especially to so called "apollonian" societies, sorting them according to the emotions they use to control individuals (especially children) and maintaining social order, swaying them into norm obedience and conformity. The terminology was popularized by Ruth Benedict in The Chrysanthemum and the Sword, who described American culture as a "guilt culture" and Japanese culture as a "shame culture".
  • 15.5K
  • 04 Nov 2022
Topic Review
Multiverse (Religion)
The concept of a multiverse is explored in various religious cosmologies that propose that the totality of existence comprises multiple or infinitely many universes, including our own. Usually, such beliefs include a creation myth, a history, a worldview and a prediction of the eventual fate or destiny of the world. The worldview discusses the current organizational form of our universe and may contain references to other supernatural world or worlds. These references have aided several esoteric practices, including contacts with spirit worlds, and activities concerning personal or inner spiritual development. Many of these worlds include an afterlife existence, which may be very different from existence in the physical plane or the world of the living; common afterlife realms include heaven, hell, and realm of the dead. Eschatological scenarios may include a new, different world after the end time of the current world. For example, Hindu cosmology includes the idea of an infinite cycle of births and deaths and an infinite number of universes with each cycle lasting 8.64 billion years. The cosmological ideas in various religious traditions have clearly evolved in time due to the introduction of new concepts and the exchange of ideas with other cultures. Nevertheless, perennial philosophers believe that these traditions all share a single supernatural truth or origin.
  • 15.5K
  • 21 Nov 2022
Topic Review
Pharmakon
Pharmakon, in philosophy and critical theory, is a composite of three meanings: remedy, poison, and scapegoat. The first and second senses refer to the everyday meaning of pharmacology (and to its sub-field, toxicology), deriving from the Greek source term φάρμακον (phármakon), denoting any drug, while the third sense refers to the pharmakos ritual of human sacrifice. A further sub-sense of pharmakon as remedy which is of interest to some current authors is given by the Liddell-Scott-Jones Greek–English Lexicon as "a means of producing something". In recent philosophical work, the term centers on Jacques Derrida's "Plato's Pharmacy", and the notion that writing is a pharmakon. Whereas a straightforward view on Plato's treatment of writing (in Phaedrus) suggests that writing is to be rejected as strictly poisonous to the ability to think for oneself in dialogue with others (i.e. to anamnesis), Bernard Stiegler argues that "the hypomnesic appears as that which constitutes the condition of the anamnesic"—in other words, externalised time-bound communication is necessary for original creative thought, in part because it is the primordial support of culture. Michael Rinella has written a book-length review of the pharmakon within a historical context, with an emphasis on the relationship between pharmakoi in the standard drug sense and the philosophical understanding of the term. Adrian Mróz, a Polish-American philosopher and musician, analyses its application to art and argues that pharmakon is any physical, mental, or behavioral object which can cut (techne). In other words, pharmaka are agential and responsible for changes in consciousness.
  • 15.5K
  • 07 Nov 2022
Topic Review
Throughput
In general terms, throughput is the rate of production or the rate at which something is processed. When used in the context of communication networks, such as Ethernet or packet radio, throughput or network throughput is the rate of successful message delivery over a communication channel. The data these messages belong to may be delivered over a physical or logical link, or it can pass through a certain network node. Throughput is usually measured in bits per second (bit/s or bps), and sometimes in data packets per second (p/s or pps) or data packets per time slot. The system throughput or aggregate throughput is the sum of the data rates that are delivered to all terminals in a network. Throughput is essentially synonymous to digital bandwidth consumption; it can be analyzed mathematically by applying the queueing theory, where the load in packets per time unit is denoted as the arrival rate (λ), and the throughput, where the drop in packets per time unit, is denoted as the departure rate (μ). The throughput of a communication system may be affected by various factors, including the limitations of underlying analog physical medium, available processing power of the system components, and end-user behavior. When various protocol overheads are taken into account, useful rate of the transferred data can be significantly lower than the maximum achievable throughput; the useful part is usually referred to as goodput.
  • 15.4K
  • 20 Oct 2022
Topic Review
Constructivist Epistemology
Constructivist epistemology is a branch in philosophy of science maintaining that scientific knowledge is constructed by the scientific community, who seek to measure and construct models of the natural world. Natural science therefore consists of mental constructs that aim to explain sensory experience and measurements. According to constructivists, the world is independent of human minds, but knowledge of the world is always a human and social construction. Constructivism opposes the philosophy of objectivism, embracing the belief that a human can come to know the truth about the natural world not mediated by scientific approximations with different degrees of validity and accuracy. According to constructivists there is no single valid methodology in science, but rather a diversity of useful methods.
  • 15.4K
  • 28 Nov 2022
Topic Review
Complement (Set Theory)
In set theory, the complement of a set A, often denoted by Ac (or A′), is the set of elements not in A. When all sets in the universe, i.e. all sets under consideration, are considered to be members of a given set U, the absolute complement of A is the set of elements in U that are not in A. The relative complement of A with respect to a set B, also termed the set difference of B and A, written [math]\displaystyle{ B \setminus A, }[/math] is the set of elements in B that are not in A.
  • 15.3K
  • 28 Nov 2022
Topic Review
Extraction Techniques in Sample Preparation
Sample preparation is the most crucial step in the analytical procedure designed for implementation in any analytical application (food analysis, bionalysis, forensics, toxicology, environmental monitoring etc). It is the limiting factor in chemical analysis since it is time consuming and it can potentially introduce errors. No one can doubt that the best approach would be the direct introduction of the sample to the instrument, however this is rarely feasible. Efficient sample pretreatment is inevitably required as the instrument technology has produced highly sophisticated and sensitive analytical equipment. Hence, the analytical scientists have to develop and apply a suitable sample preparation protocol that ensures that the composition of the sample remains unchanged, no impurities are introduced during handling, all interferences have been left back, the analytes’ concentration is not only at detectable levels, but it can also be quantified precisely and accurately and that the matrix of the sample is compatible with the analytical technique. Extraction techniques are the most powerful tool in hands of the analytical chemists and lab practitioners. Either sorbent based or solvent based, extraction techniques provide the necessary tool that can be used to handle the sample in a way that all information in it can be revealed, all advantages in instrumentation have been exploited to the fullest and the lifetime of the instrument is prolonged in a seamless operation mode.
  • 15.3K
  • 28 Oct 2020
Topic Review
Algal Evolution
Phylogenetically algae is regarded as polyphyletic as its origin cannot be traced back to single common hypothetical ancestor. However, genomic studies on algae suggest that algae evolved through endosymbiosis giving rise to at least eight to nine phyla over a period of time.
  • 15.3K
  • 25 Nov 2020
Topic Review
White Flag
Flag White flags have had different meanings throughout history and depending on the locale.
  • 15.2K
  • 02 Nov 2022
Topic Review
Nutritional Value of Fish
Fish are considered highly nutritious products of the aquaculture system due to the presence of well-balanced macronutrients such as proteins, lipids and micronutrients such as vitamins and minerals
  • 15.1K
  • 28 Nov 2022
Topic Review
Adolescents Malnutrition
Adolescents are young individuals that are between the ages of 10 and 19 years old.  Malnutrition refers to deficiencies, excesses or imbalances in an individual intake of energy and/or nutrients 
  • 15.0K
  • 16 Jul 2021
Topic Review
Number of the Beast
The number of the beast (Greek: Ἀριθμὸς τοῦ θηρίου, Arithmos tou Thēriou), also known as The devil's number is a term in the Book of Revelation, of the New Testament, that is associated with the Beast of Revelation in chapter 13, verse 18. In most manuscripts of the New Testament and in English translations of the Bible, the number of the beast is six hundred and sixty-six or χξϛ (the number not being representable by the repetition of 6 or ϛ three times – Greek for 6 is ϛ, but ϛϛϛ is not six hundred sixty-six). Papyrus 115 (which is the oldest preserved manuscript of the Revelation (As of 2017)), as well as other ancient sources like Codex Ephraemi Rescriptus, give the number of the beast as χιϛ or χιc (transliterable in Arabic numerals as 616) (χιϛ), not 666; critical editions of the Greek text, such as the Novum Testamentum Graece, note 616 as a variant.
  • 15.0K
  • 30 Nov 2022
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