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:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Green Monopropellants
Green propellants are usually defined as low-hazard, low-toxicity, environmentally friendly propellants that are considered safe during various phases of spacecraft development, launch, and operations. Such propellants provide safe handling and storability when compared to conventional toxic propellants such as hydrazine and its derivatives that require special handling protocols and adhering to strict safety measurements that, in addition to others, include using Self-Contained Atmospheric Protective Ensemble (SCAPE) suits. Due to their favorable characteristics, green propellants demonstrate higher commercial value by being able to cut costs related to transportation, storage, handling, and further reduces ground operations time. Recently, a more specified definition has been noted by Mayer et al. (2018) [3], based on the Acute Toxicity Classification (ATC) by the Global Harmonized System of classification and labeling of chemicals (GHS) [6], which denotes that propellants possessing ATC levels of three and safer are considered as green propellants. ATC levels are typically categorized on a 1:5 scale where level one denotes the most toxic class and level five is considered the least toxic class. Moreover, a controversial topic arises when referring to some modern green propellants, whether to address them by the term “monopropellants” or by more specific terms including (premixed propellants, fuel blends, or mixtures). Monopropellants are fundamentally defined as propellants consisting of chemical compounds (for example N2H4), which release energy through exothermic chemical decomposition. Since the evolution of liquid gun propellants based on HAN compound and other nitrate salts aqueous solutions, the term “monopropellants” was used to describe such premixed formulations. As widely used in literature and industry, some modern green propellants, for instance the Energetic Ionic Liquids (EILs), are undoubtedly classified and described as “monopropellants.” Basically, it can be interpreted from the previous that a "green monopropellant" may be defined as: "A low-hazard, low-toxicity, and safe-to handle propellant that is stored in a single tank and is able to decompose from its storage state by the help of a catalyst or other ignition method, such as thermal or electric ignition, can be considered a “green monopropellant” as long as it does not require another separately stored propellant for decomposition."
  • 5.2K
  • 28 Sep 2021
Topic Review
System Theory of Corporate Sustainability
In response to the prevailing sustainability problems that are difficult to solve since they are characterized by complex interdependencies, and the effort to solve one aspect of a sustainability problem may lead to other problems, an interim, system-based theory of corporate sustainability to fill in significant gaps in the corporate sustainability field is developed. The full-blown theory helps the researchers to comprehend, describe and predict situations, behavioral actions and/or context. It guides the researchers to either go against orthodoxy or to continue with it to enrich the current knowledge domain.
  • 5.2K
  • 07 Dec 2022
Biography
Ben Shapiro
Benjamin Aaron Shapiro (born January 15, 1984)[1] is an American conservative political commentator, public speaker, media executive, author, and attorney. At age 17, he became the youngest nationally syndicated columnist in the United States.[2][3][4] He writes columns for Creators Syndicate and Newsweek, serves as editor-in-chief for The Daily Wire, which he founded, and hosts The Ben Shapiro
  • 5.2K
  • 06 Dec 2022
Topic Review
Hazard
A hazard is an agent which has the potential to cause harm to a vulnerable target. The terms "hazard" and "risk" are often used interchangeably. However, in terms of risk assessment, they are two very distinct terms. A hazard is any agent that can cause harm or damage to humans, property, or the environment. Risk is defined as the probability that exposure to a hazard will lead to a negative consequence, or more simply, a hazard poses no risk if there is no exposure to that hazard. Hazards can be dormant or potential, with only a theoretical probability of harm. An event that is caused by interaction with a hazard is called an incident. The likely severity of the undesirable consequences of an incident associated with a hazard, combined with the probability of this occurring, constitute the associated risk. If there is no possibility of a hazard contributing towards an incident, there is no risk. Hazards can be classified as different types in several ways. One of these ways is by specifying the origin of the hazard. One key concept in identifying a hazard is the presence of stored energy that, when released, can cause damage. Stored energy can occur in many forms: chemical, mechanical, thermal, radioactive, electrical, etc. Another class of hazard does not involve release of stored energy, rather it involves the presence of hazardous situations. Examples include confined or limited egress spaces, oxygen-depleted atmospheres, awkward positions, repetitive motions, low-hanging or protruding objects, etc. Hazards may also be classified as natural, anthropogenic, or technological. They may also be classified as health or safety hazards, by the populations that may be affected, and the severity of the associated risk. In most cases a hazard may affect a range of targets, and have little or no effect on others. Identification of hazards assumes that the potential targets are defined, and is the first step in performing a risk assessment.
  • 5.2K
  • 26 Oct 2022
Topic Review
Teeth Blackening
Teeth blackening or teeth lacquering is a custom of dyeing one's teeth black. It was most predominantly practiced in Southeast Asian and Oceanic cultures, particularly among Austronesian, Austroasiatic, and Kra-Dai-speaking peoples. It was also practiced in Japan prior to the Meiji era, as well as in India. It was also performed among some groups in the Americas, most notably among the Shuar people of northern Peru and Ecuador. Teeth blackening is usually done during puberty. It was primarily done to preserve the teeth into old age, as it prevents tooth decay similar to the mechanism of modern dental sealants. It was seen as a sign of maturity, beauty, and civilization. A common belief is that blackened teeth differentiated humans from animals. Teeth blackening is often done in conjunction with traditions of tooth sharpening and evulsion, as well as other body modification customs like tattoos. Teeth blackening and filing were regarded with fascination and disapproval by early European explorers and colonists. The practice survives in some isolated ethnic groups in Southeast Asia and Oceania but has mostly disappeared after the introduction of Western beauty standards during the colonial era, and continues among many minority groups in China, Pacific Islands and Southeast Asia. It is mainly prevalent in older women, though the practice is still carried on by some younger women. Sometimes artificial teeth are used to achieve blackened teeth. Teeth blackening is commonly confused with the red-stained teeth from betel chewing. However, betel chewing damages the teeth and gums, while teeth blackening does not.
  • 5.2K
  • 21 Nov 2022
Topic Review
Pomegranate in the Treatment of Respiratory Diseases
The pomegranate fruit is made of white to deep purple seeds that are enclosed in a white, spongy, astringent membrane, also known as pericarp, covered by a thick red skin and a crown-shaped calyx. It contains a variety of beneficial ingredients, including flavonoids, ellagitannin, punicalagin, ellagic acid, vitamins, and minerals. Pomegranates possess numerous health benefits, and their use in disease treatment has been widely recognized since antiquity.
  • 5.2K
  • 06 Jan 2023
Topic Review
Ivermectin during the COVID-19 Pandemic
Ivermectin (IVM) is a broad-spectrum antiparasitic agent, developed and funded by Merck & Co. in 1974 to control and eradicate onchocerciasis caused by the parasitic worm Onchocerca volvulus in West Africa, which in the 1980s infected approximately 340,000 people. At the time, Africa did not have the resources necessary to seek treatments for this condition. The avermectins, of which IVM is a member, were discovered by Professor Satoshi Ōmura as fermentation products of the bacterium Streptomyces avermitilis at the Kitasato Institute in Tokyo. For this discovery, he received the 2015 Nobel Prize in Physiology and Medicine, which he shared with William Campbell. IVM is used to treat onchocerciasis, lymphatic filariasis, strongyloidiasis and scabies, and, very recently, has been used to combat lice. The drug’s low cost, high efficacy, safety, and marked tropism for helminths, as well as the fact that it has almost no impact on human biochemistry, have led to the inclusion of IVM in the twentieth list of essential medicines and sixth list of vital medicines in children, a recommendation made by the expert committee of the World Health Organization (WHO) in 2019. The safety profile is attributed to its selective affinity for ion channels.
  • 5.2K
  • 22 Sep 2022
Topic Review
Commune (Model of Government)
The commune, as a model of government, is generally advocated by some communists, revolutionary socialists, and anarchists. Communes are an organizational community with social cohesion derived from a shared culture. As a governing community, a commune often entails some degree of local governance, communal ownership, and cultural cohesion. However, models that do not include all three aspects may still be described as communes. At its core, a commune is just an organization which creates social conditions that prioritize the primacy of the collective over the individual. Many different forms of commune-based governments are possible, such as a local and sovereign community which is both a microstate and a nation-state, a federated commune which lacks a degree of sovereignty under the rule of a larger state, or a larger national community which focuses more on aspects of communal ownership rather than communal governance.
  • 5.2K
  • 09 Nov 2022
Topic Review
United Express Flight 3411 Incident
Template:Infobox Aircraft occurrence The United Express Flight 3411 incident occurred at Chicago O'Hare International Airport, United States on April 9, 2017, when Dr. David Dao Duy Anh, a Vietnamese-American passenger, was injured while being forcibly removed from a fully boarded, sold-out flight to Louisville International Airport. Dao, a pulmonologist and folk musician, refused to surrender his seat when requested because he needed to see patients the following day. Chicago Department of Aviation Security officers were called to remove him from the plane; in the process, they struck Dao's face against an armrest, then pulled him, apparently unconscious, by his arms along the aircraft aisle past rows of onlooking passengers. Prior to the confrontation, United agents offered travel vouchers to passengers to vacate their seats to make room for four deadheading Republic Airways employees, but none of the passengers accepted. United then selected four passengers for involuntary removal from the flight, one of whom was Dao, and the three other passengers agreed to leave. Flight 3411 was operated by Republic Airways on behalf of United Express, a United Airlines regional branch. Video of the incident recorded by passengers went viral on social media, resulting in anger over the force that was used. Politicians expressed concern and called for an official investigation. Then-U.S. President Donald Trump criticized United Airlines, calling its treatment of Dao "horrible." The next morning, then-CEO of United, Oscar Munoz, issued a statement that appeared to justify the removal of Dao, referring to "re-accommodating the customers." Munoz also sent an email to United staff commending the crew's actions for following established procedures and referring to Dao as "disruptive" and "belligerent," though this characterization contradicted passengers' accounts of the incident. Passenger Jason Powell asserted that Dao was not belligerent, saying instead, "He was very polite, matter-of-fact." Cell phone video by passenger Joya Cummings also contradicted Munoz's description of Dao as belligerent. Munoz and United were sharply criticized for their initial statements, and United suffered a drop in its stock price. Two days after the incident, Munoz issued an additional statement, apologizing and promising that such an incident would never again occur on a United aircraft. He said, "No one should ever be mistreated this way." In an ABC television interview, Munoz was asked, "Do you think [Dao] was at fault in any way?" Munoz responded, "No. He can't be. He was a paying passenger sitting on our seat in our aircraft." Munoz's previously planned promotion to become United's chairman was delayed until May 2020 as a result of the incident. Dao reached an "amicable" settlement with United on April 27, 2017, though its terms were not publicly announced.
  • 5.2K
  • 24 Oct 2022
Topic Review
Connectivity Architecture
Connectivity architecture connects main functional blocks or entities of a system with well-defined interfaces enabling interoperability, fluent data flows and information sharing in timely manner. Local connectivity architecture defines e.g. the architecture inside an autonomous ship. The wider-scale architecture includes geographically distributed entities such as vessels, databases, and remote operations centers.
  • 5.2K
  • 17 Aug 2020
Topic Review
Technology and Society
Technology society and life or technology and culture refers to the inter-dependency, co-dependence, co-influence, and co-production of technology and society upon one another. Evidence for this synergy has been found since humanity first started using simple tools. The inter-relationship has continued as modern technologies such as the printing press and computers have helped shape society. The first scientific approach to this relationship occurred with the development of tektology, the "science of organization", in early twentieth century Imperial Russia. In modern academia, the interdisciplinary study of the mutual impacts of science, technology, and society, is called science and technology studies. The simplest form of technology is the development and use of basic tools. The prehistoric discovery of how to control fire and the later Neolithic Revolution increased the available sources of food, and the invention of the wheel helped humans to travel in and control their environment. Developments in historic times have lessened physical barriers to communication and allowed humans to interact freely on a global scale, such as the printing press, telephone, and Internet. Technology has developed advanced economies, such as the modern global economy, and has led to the rise of a leisure class. Many technological processes produce by-products known as pollution, and deplete natural resources to the detriment of Earth's environment. Innovations influence the values of society and raise new questions in the ethics of technology. Examples include the rise of the notion of efficiency in terms of human productivity, and the challenges of bioethics. Philosophical debates have arisen over the use of technology, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar reactionary movements criticize the pervasiveness of technology, arguing that it harms the environment and alienates people. However, proponents of ideologies such as transhumanism and techno-progressivism view continued technological progress as beneficial to society and the human condition.
  • 5.2K
  • 24 Nov 2022
Topic Review
Edible Mushrooms
Edible mushrooms are considered an important next-generation healthy food source. Edible mushrooms are rich in proteins, dietary fiber, vitamins, minerals, and other bioactive components (alkaloids, lactones, polysaccharides, polyphenolic compounds, sesquiterpenes, sterols, and terpenoids). 
  • 5.2K
  • 06 Dec 2022
Topic Review
Lithium Recovery via Chemical Precipitation
Lithium is a vital raw material used for a wide range of applications, such as the fabrication of glass, ceramics, pharmaceuticals, and batteries for electric cars. The accelerating electrification transition and the global commitment to decarbonization have caused an increasing demand for lithium. The current supply derived from brines and hard rock ores is not enough to meet the global demand unless alternate resources and efficient techniques to recover this valuable metal are implemented. 
  • 5.2K
  • 21 Feb 2023
Topic Review
Current Applications of Membrane Bioreactors
A membrane bioreactor (MBR) can be described as a chamber designed for a biochemical transformation combined with a membrane separation process. The membrane can be used for different purposes inside the bioreactor, such as the addition of a reactant or the selective removal of one of the reaction products. Moreover, membranes can be utilized to retain the biocatalyst or act as the support for the biocatalyst or for the separation of enzymes by size exclusion.
  • 5.2K
  • 21 Oct 2020
Topic Review
Left-Wing Market Anarchism
Left-wing market anarchism is a strand of free-market anarchism and an individualist anarchist, left-libertarian and libertarian socialist political philosophy and market socialist economic theory stressing the value of radically free markets, termed freed markets to distinguish them from the common conception which these libertarians believe to be riddled with statist and capitalist privileges. Proponents of this approach distinguish themselves from right-libertarians and strongly affirm the classical liberal ideas of self-ownership and free markets while maintaining that taken to their logical conclusions these ideas support anti-capitalist, anti-corporatist, anti-hierarchical and pro-labor positions in economics; anti-imperialism in foreign policy; and thoroughly radical views regarding socio-cultural issues. Key theorists in this area include contemporary scholars such as Kevin Carson, Gary Chartier, Charles W. Johnson, Roderick T. Long, Chris Matthew Sciabarra, Ryan Neugebauer, Sheldon Richman and Brad Spangler. The genealogy of left-wing market anarchism, sometimes labeled market-oriented or free-market left-libertarianism, overlaps to a significant degree with that of Steiner–Vallentyne left-libertarianism as the roots of that tradition are sketched in the book The Origins of Left-Libertarianism. Carson–Long-style left-libertarianism is rooted in 19th-century mutualism and in the work of figures such as Thomas Hodgskin, French Liberal School thinkers such as Gustave de Molinari and American individualist anarchists such as Benjamin Tucker and Lysander Spooner, among others. Several left-wing market anarchists who come from the left-Rothbardian school or tradition cite Murray Rothbard's homestead principle with approval to support worker cooperatives. While with notable exceptions libertarians in the United States after the heyday of individualist anarchism tended to ally with the political right, relationships between such libertarians and the New Left thrived in the 1960s, laying the groundwork for modern left-wing market anarchism. Left-wing market anarchism identifies with left-libertarianism, a position which names several related yet distinct approaches to politics, society, culture and political and social theory, stressing both individual freedom and social justice. Unlike right-libertarians, left-libertarians believe that neither claiming nor mixing one's labor with natural resources is enough to generate full private property rights and maintain that all natural resources such as land, oil and gold ought to be held in some egalitarian manner, either unowned or owned collectively. Those left-libertarians who support private property do so under different property norms and theories, or under the condition that recompense is offered to the local or global community.
  • 5.2K
  • 30 Nov 2022
Topic Review
Immunoformulation for COVID-19
The number of patients infected with the SARS-CoV-2 is still growing worldwide, with no current vaccine or medicinal treatment up to this date. Here we describe the cases of four COVID-19 patients that used a combination of therapeutic/nutraceutical agents for improvement of their symptoms. The ingredients were: immune transfer factor (oligo- and polypeptides fractions from porcine spleen, ultrafiltered at <10 kDa; Imuno TF®), anti-inflammatory natural blend (Uncaria tomentosa, Endopleura uchi and Haematoccocus pluvialis; Miodesin®), zinc, selenium, ascorbic acid, cholecalciferol, ferulic acid, spirulina, N-acetylcysteine, glucosamine sulfate potassium hydrochloride, trans-resveratrol, and maltodextrin-stabilized orthosilicic acid (SiliciuMax®). The four showed improvement in general symptoms after using the combination proposed here. The cases presented here are just a first hint towards its benefit (decreases time necessary for the recovery of the patients), this would be a good starting point to the further investigation of this possible add-on therapy in controlled clinical studies. Limited sample size and study design are limitations for definitive conclusions on the add-on therapy.
  • 5.2K
  • 05 Nov 2020
Topic Review
Community Counseling
Guidance and counseling is a process of helping an individual become fully aware of his/ herself and the ways in which he is responding to the influence of his/her environment. Counseling is a generic term for any of professional counseling that treats dysfunction occurring within a group of related people. This term describes a preventive system of counseling that works to combat psychological impairment through the improvement and development of community support. A community is defined as a group of interacting individuals who share a commonality. This commonality can be anything from location of residence to career interest, but a community counselor will use this common characteristic to council groups of people.
  • 5.2K
  • 17 Oct 2022
Topic Review
Reflective Practice
Reflective practice is the ability to reflect on one's actions so as to engage in a process of continuous learning. According to one definition it involves "paying critical attention to the practical values and theories which inform everyday actions, by examining practice reflectively and reflexively. This leads to developmental insight". A key rationale for reflective practice is that experience alone does not necessarily lead to learning; deliberate reflection on experience is essential. Reflective practice can be an important tool in practice-based professional learning settings where people learn from their own professional experiences, rather than from formal learning or knowledge transfer. It may be the most important source of personal professional development and improvement. It is also an important way to bring together theory and practice; through reflection a person is able to see and label forms of thought and theory within the context of his or her work. A person who reflects throughout his or her practice is not just looking back on past actions and events, but is taking a conscious look at emotions, experiences, actions, and responses, and using that information to add to his or her existing knowledge base and reach a higher level of understanding.
  • 5.2K
  • 14 Nov 2022
Topic Review
Mass Transfer in Packed-Bed Columns
This review provides a thorough analysis of the most famous mass transfer models for random and structured packed-bed columns used in absorption/stripping and distillation processes, providing an overview of the equations to calculate the mass transfer parameters, i.e.: gas-side coefficient per unit surface ky [kmol·m-2·s-1], liquid-side coefficient per unit surface kx [kmol·m-2·s-1], interfacial packing area ae [m2·m-3], which constitute the ingredients to assess the mass transfer rate of packed-bed columns. This work also provides the ranges of model validity and applicability together with their main pros and cons and the criticalities behind these models, which mostly rely on the assessment of fluid-dynamics parameters such as liquid film thickness, liquid hold-up and interfacial area, or the real liquid paths or any mal-distributions flow. 
  • 5.2K
  • 01 Sep 2021
Topic Review
Smart manufacturing, an advanced form of traditional manufacturing
Traditional manufacturing is an industrial process that converts materials into a finished product using a labor-intensive low-end operation, low precision, average resource utilization and efficiency for economic value.
  • 5.2K
  • 28 Mar 2022
  • Page
  • of
  • 2753
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback