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:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Gravity Well
A gravity well or gravitational well is a conceptual model of the gravitational field surrounding a body in space – the more massive the body, the deeper and more extensive the gravity well associated with it. The Sun is very massive, relative to other bodies in the Solar System, so the corresponding gravity well that surrounds it appears "deep" and far-reaching. The gravity wells of asteroids and small moons, conversely, are often depicted as very shallow. Anything at the center of mass of a planet or moon is considered to be at the bottom of that celestial body's gravity well, and so escaping the effects of gravity from such a planet or moon (to enter outer space) can be likened to "climbing out of the gravity well". The deeper a gravity well is, the more energy any space-bound "climber" must use to escape it. In astrophysics, a gravity well is specifically the gravitational potential field around a massive body. Other types of potential wells include electrical and magnetic potential wells. Physical models of gravity wells are sometimes used to illustrate orbital mechanics. Gravity wells are frequently confused with embedding diagrams used in general relativity theory, but the two concepts are distinctly separate and not directly related.
  • 5.9K
  • 12 Oct 2022
Topic Review
New Literacies
New literacies generally are new forms of literacy made possible by digital technology developments, although new literacies do not necessarily have to involve use of digital technologies to be recognized as such. The term "new literacies" itself is relatively new within the field of literacy studies (the first documented mention of it in an academic article title dates to 1993 in a text by David Buckingham). Its definition remains open, with new literacies being conceptualized in different ways by different groups of scholars. For example, one group of scholars argues that literacy is now deictic, and see it as continually and rapidly changing as new technologies appear and new social practices for literacy emerge. (Leu, 2000). This group aims at developing a single, overarching theory to help explain new literacies (see, for example, Leu, O'Byrne, Zawilinski, McVerry, & Everett-Cacopardo, 2009; see also, below). This orientation towards new literacies is largely psycholinguistic in nature. Other groups of scholars follow a more sociocultural orientation that focuses on literacy as a social practice, which emphasizes the role of literacy with a range of socially patterned and goal-directed ways of getting things done in the world (see, for example, Gee & Hayes, 2012; Lankshear & Knobel, 2011; Kalantzis and Cope 2011). Accompanying the varying conceptualizations of new literacies, there are a range of terms used by different researchers when referring to new literacies, including 21st century literacies, internet literacies, digital literacies, new media literacies, multiliteracies, information literacy, ICT literacies, and computer literacy. In the Handbook of New Literacies Research, Coiro, Knobel, Lankshear, and Leu (2008) note that all these terms "are used to refer to phenomena we would see as falling broadly under a new literacies umbrella" (pg. 10). Commonly recognized examples of new literacies include such practices as instant messaging, blogging, maintaining a website, participating in online social networking spaces, creating and sharing music videos, podcasting and videocasting, photoshopping images and photo sharing, emailing, shopping online, digital storytelling, participating in online discussion lists, emailing and using online chat, conducting and collating online searches, reading, writing and commenting on fan fiction, collaborating on and writing encyclopedic wikis, processing and evaluating online information, creating and sharing digital mashups, etc. (see: Black, 2008; Coiro, 2003; Gee, 2007; Hunter, 2014; Jenkins, 2006; Kist, 2007; Lankshear & Knobel, 2006; Lessig, 2005; Leu, et al. 2004; Prensky, 2006).
  • 5.9K
  • 14 Oct 2022
Topic Review
Brilliant Blue FCF
Brilliant Blue FCF (Blue 1) is a synthetic organic compound used primarily as a blue colorant for processed foods, medications, dietary supplements, and cosmetics. It is classified as a triarylmethane dye and is known under various names, such as FD&C Blue No. 1 or Acid Blue 9. It is denoted by E number E133 and has a color index of 42090. It has the appearance of a blue powder and is soluble in water and glycerol, with a maximum absorption at about 628 nanometers. It is one of the oldest FDA-approved color additives and is generally considered nontoxic and safe.
  • 5.9K
  • 17 Nov 2022
Topic Review
Fault Types and Effects of HVDC Transmission Systems
High voltage direct current (HVDC) transmission systems play a critical role to optimize resource allocation and stabilize power grid operation in the current power grid thanks to their asynchronous networking and large transmission capacity. To ensure the operation reliability of the power grid and reduce the outage time, it is imperative to realize fault diagnosis of HVDC transmission systems in a short time. 
  • 5.9K
  • 11 Nov 2022
Topic Review
Psychological Effects of Method Acting
Method acting is employed by actors to evoke realistic emotions into their performance by drawing on personal experiences. Raymond Hamden, doctor of Clinical and Forensic Psychology, defines the purpose of method acting as “compartmentalizing their own feelings while playing another character [so] they could bring the emotions of that personal feeling to cry if they needed to with that character.” However, when these emotions are not compartmentalized, they can encroach on other facets of life, often seeming to disrupt the actor’s psyche. This occurs as the actor delves into previous emotional experiences, be they joyful or traumatic. The psychological effects, like emotional fatigue, comes when suppressed or unresolved raw emotions are unburied to add to the character, not just from the employing personal emotions in performance. The question becomes whether the actor calls up resolved or unresolved emotions in their acting.
  • 5.9K
  • 16 Nov 2022
Topic Review
Force Field
In the context of chemistry and molecular modelling, a force field is a computational method that is used to estimate the forces between atoms within molecules and also between molecules. More precisely, the force field refers to the functional form and parameter sets used to calculate the potential energy of a system of atoms or coarse-grained particles in molecular mechanics, molecular dynamics, or Monte Carlo simulations. The parameters for a chosen energy function may be derived from experiments in physics and chemistry, calculations in quantum mechanics, or both. Force fields are interatomic potentials and utilize the same concept as force fields in classical physics, with the difference that the force field parameters in chemistry describe the energy landscape, from which the acting forces on every particle are derived as a gradient of the potential energy with respect to the particle coordinates. All-atom force fields provide parameters for every type of atom in a system, including hydrogen, while united-atom interatomic potentials treat the hydrogen and carbon atoms in methyl groups and methylene bridges as one interaction center. Coarse-grained potentials, which are often used in long-time simulations of macromolecules such as proteins, nucleic acids, and multi-component complexes, sacrifice chemical details for higher computing efficiency.
  • 5.8K
  • 10 Nov 2022
Topic Review
Fluid Catalytic Cracking Catalyst Regeneration Intensification Technologies
Fluid catalytic cracking (FCC) is the workhorse of modern crude oil refinery. Its regenerator component plays a critical role in optimizing the overall profitability by efficiently restoring the catalyst activity and enhancing the heat balance in the riser reactor. Improvement in the device metallurgy and process operations have enabled industrial regenerators to operate at high temperatures with a better coke burning rate and longer operating cycle. Today, the carbon content of regenerated catalyst has drastically reduced to less than 0.1 wt.%.
  • 5.8K
  • 15 Mar 2022
Topic Review Video
Risk Management in Information Systems
Businesses are bombarded with great deals of risks, vulnerabilities, and unforeseen business interruptions in their lifetime, which negatively affect their productivity and sustainability within the market. Such risks require a risk management system to identify risks and risk factors and propose approaches to eliminate or reduce them. Risk management involves highly structured practices that should be implemented within an organization, including organizational planning documents. Continuity planning and fraud detection policy development are among the many critically important practices conducted through risk management that aim to mitigate risk factors, their vulnerability, and their impact. Information systems play a pivotal role in any organization by providing many benefits, such as reducing human errors and associated risks owing to the employment of sophisticated algorithms. Both the development and establishment of an information system within an organization contributes to mitigating business-related risks and also creates new types of risks associated with its establishment. Businesses must prepare for, react to, and recover from unprecedented threats that might emerge in the years or decades that follow.
  • 5.8K
  • 15 Dec 2021
Topic Review
Geiger–Marsden Experiment
The Geiger–Marsden experiments (also called the Rutherford gold foil experiment) were a landmark series of experiments by which scientists discovered that every atom has a nucleus where all of its positive charge and most of its mass is concentrated. They deduced this by measuring how an alpha particle beam is scattered when it strikes a thin metal foil. The experiments were performed between 1908 and 1913 by Hans Geiger and Ernest Marsden under the direction of Ernest Rutherford at the Physical Laboratories of the University of Manchester.
  • 5.8K
  • 21 Oct 2022
Topic Review
Generations of Glucose Biosensors
Electrochemical glucose biosensors are widely applied for glucose monitoring due to their unbeatable sensitivity, selectivity, and simplicity. In general, there are four primary generations of glucose biosensor, which are classified according to the electron transfer mechanism. Three generations represent the enzymatic glucose biosensor, and one generation represents the non-enzymatic glucose biosensor.
  • 5.8K
  • 14 Dec 2022
  • Page
  • of
  • 5353
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
Video Production Service
Feedback