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
Productivity Improving Technologies
The productivity improving technologies are the technological innovations that have historically increased productivity. Productivity is often measured as the ratio of (aggregate) output to (aggregate) input in the production of goods and services. Productivity is increased by lowering the amount of labor, capital, energy or materials that go into producing any given amount of economic goods and services. Increases in productivity are largely responsible for the increase in per capita living standards.
  • 3.1K
  • 23 Nov 2022
Topic Review
Membrane in a Microbial Fuel Cell
Microbial fuel cells (MFC) are an emerging technology for wastewater treatment that utilizes the metabolism of microorganisms to generate electricity from the organic matter present in water directly.
  • 3.1K
  • 20 Jan 2022
Topic Review
Book of Dzyan
The Book of Dzyan (comprising the Stanzas of Dzyan) is a reputedly ancient text of Tibetan origin. The Stanzas formed the basis for The Secret Doctrine (1888), one of the foundational works of the theosophical movement, by Helena Petrovna Blavatsky.
  • 3.1K
  • 21 Nov 2022
Topic Review
UAVs in the U.S. Military
As of January 2014, the U.S. military operates a large number of unmanned aerial systems (UAVs or Unmanned Air Vehicles): 7,362 RQ-11 Ravens; 990 AeroVironment Wasp IIIs; 1,137 AeroVironment RQ-20 Pumas; and 306 RQ-16 T-Hawk small UAS systems and 246 Predators and MQ-1C Grey Eagles; 126 MQ-9 Reapers; 491 RQ-7 Shadows; and 33 RQ-4 Global Hawk large systems. The military role of unmanned aircraft systems is growing at unprecedented rates. In 2005, tactical- and theater-level unmanned aircraft alone had flown over 100,000 flight hours in support of Operation Enduring Freedom and Operation Iraqi Freedom, in which they are organized under Task Force Liberty in Afghanistan and Task Force ODIN in Iraq. Rapid advances in technology are enabling more and more capability to be placed on smaller airframes, which is spurring a large increase in the number of Small Unmanned Aircraft Systems (SUAS) being deployed on the battlefield. The use of SUAS in combat is so new that no formal DoD wide reporting procedures have been established to track SUAS flight hours. As the capabilities grow for all types of UAS, nations continue to subsidize their research and development, leading to further advances and enabling them to perform a multitude of missions. UAS no longer only perform intelligence, surveillance, and reconnaissance missions, although this still remains their predominant type. Their roles have expanded to areas including electronic attack, drone strikes, suppression or destruction of enemy air defense, network node or communications relay, combat search and rescue, and derivations of these themes. These UAS range in cost from a few thousand dollars to tens of millions of dollars, with aircraft ranging from less than one pound to over 40,000 pounds.
  • 3.1K
  • 14 Oct 2022
Topic Review
Phytohormone Regulation of Apple-Fruit Ripening
Apple (Malus domestica) is, globally, one of the largest fruits in terms of cultivated area and yield. Apple fruit is generally marketed after storage, which is of great significance for regulating the market supply in the off-season of fruit production. Apple-fruit ripening, which culminates in desirable changes in structural and textural properties, is governed by a complex regulatory network. 
  • 3.1K
  • 22 Oct 2021
Topic Review
Analysis of Point Machines and Monitoring Systems
Point machines are the actuators for railway switching and crossing systems that guide trains from one track to another. Hence, the safe and reliable behavior of point machines are pivotal for rail transportation. Scholars and researchers have attempted to deploy various kinds of sensors on point machines for anomaly detection and/or incipient fault detection using date-driven algorithms. However, challenges arise when deploying condition monitoring and fault detection to trackside point machines in practical applications. 
  • 3.1K
  • 25 Oct 2023
Topic Review
Pyrolysis of Polystyrene Waste
The manufacturing of polystyrene around the globe has escalated in the past years due to its huge applications in various areas. The perpetual market needs of polystyrene led the polystyrene wastes accretion in the landfill causing environmental deterioration. The soaring need for polystyrene also led to the exhaustion of petroleum, a non-renewable energy source, as polystyrene is a petroleum-derived product.
  • 3.1K
  • 28 Sep 2021
Topic Review
Ring
Ring LLC is a home security and smart home company owned by Amazon. Ring manufactures home security products that incorporate outdoor surveillance cameras, including the Ring Video Doorbell smart doorbell, and hosts an app, Neighbors, for online social sharing of captured footage among users. Ring also provides video footage from its cameras and data from its Neighbors app to law enforcement agencies on request. Its police partnerships have been criticized by civil rights advocacy groups as building an invasive private surveillance network.
  • 3.1K
  • 18 Oct 2022
Topic Review
Planet-Hosting Stars
Planet-hosting stars are stars which host planets, therefore forming planetary systems. This article describes the correlations between stars' characteristics and the characteristics of the planets that orbit them, and other connections between stars and their planets.
  • 3.1K
  • 23 Nov 2022
Topic Review
Reactive Oxygen Species
Reactive oxygen species (ROS) can directly activate HSCs or induce inflammation or programmed cell death, especially pyroptosis, in hepatocytes, which in turn activates HSCs and fibroblasts to produce ECM proteins.
  • 3.1K
  • 27 Jan 2022
Topic Review
Autonomous Underwater Vehicles
Development of Autonomous Underwater Vehicles (AUV's) has permitted the automatization of many tasks originally achieved with manned vehicles in underwater environments. Teams of AUV's designed to work within a common mission are opening the possibilities for new and more complex applications. In underwater environments, communication, localization, and navigation of AUV's are considered challenges due to the impossibility of relying on radio communications and global positioning systems. For a long time, acoustic systems have been the main approach for solving these challenges. However, they present their own shortcomings, which are more relevant for AUV's teams. As a result, researchers have explored different alternatives. To summarize and analyze these alternatives, a review of the literature is presented in this paper. Finally, a summary of collaborative AUV's teams and missions is also included, with the aim of analyzing their applicability, advantages, and limitations.
  • 3.1K
  • 28 Oct 2020
Topic Review
Anti-Icing Surfaces
In numerous fields such as aerospace, the environment, and energy supply, ice generation and accretion represent a severe issue. For this reason, numerous methods have been developed for ice formation to be delayed and/or to inhibit ice adhesion to the substrates. Among them, laser micro/nanostructuring of surfaces aiming to obtain superhydrophobic behavior has been taken as a starting point for engineering substrates with anti-icing properties. 
  • 3.1K
  • 17 Mar 2021
Topic Review
Lingua Geographica
Geographic tongue, also known by several other terms,[note 1] is a condition of the mucous membrane of the tongue, usually on the dorsal surface. It is a common condition, affecting approximately 2–3% of the general population. It is characterized by areas of smooth, red depapillation (loss of lingual papillae) which migrate over time. The name comes from the map-like appearance of the tongue, with the patches resembling the islands of an archipelago. The cause is unknown, but the condition is entirely benign (importantly, it does not represent oral cancer), and there is no curative treatment. Uncommonly, geographic tongue may cause a burning sensation on the tongue, for which various treatments have been described with little formal evidence of efficacy.
  • 3.1K
  • 26 Oct 2022
Biography
Benjamin Hick
Benjamin Hick (1 August 1790 – 9 September 1842) was a successful English civil and mechanical engineer, art collector and patron;[1] his improvements to the steam engine and invention of scientific tools were held in high esteem by the engineering profession,[2] some of Hick's improvements became public property without claiming the patent rights he was entitled to.[3] He was born at Hudder
  • 3.1K
  • 28 Nov 2022
Topic Review
Hybrid Prognostic Approaches of Aircraft Systems and Components
Prognostic and health management (PHM) plays a vital role in ensuring the safety and reliability of aircraft systems. The process entails the proactive surveillance and evaluation of the state and functional effectiveness of crucial subsystems. The principal aim of PHM is to predict the remaining useful life (RUL) of subsystems and proactively mitigate future breakdowns in order to minimize consequences. The achievement of this objective is helped by employing predictive modeling techniques and doing real-time data analysis. The incorporation of prognostic methodologies is of utmost importance in the execution of condition-based maintenance (CBM), a strategic approach that emphasizes the prioritization of repairing components that have experienced quantifiable damage. Multiple methodologies are employed to support the advancement of prognostics for aviation systems, encompassing physics-based modeling, data-driven techniques, and hybrid prognosis. 
  • 3.1K
  • 10 Oct 2023
Topic Review
Unbiased Expectation Theory
Unbiased expectation theory (UET), which posits that long-term interest rates are determined by the market’s expectations of future short-term interest rates, is a fundamental concept in the field of fixed-income securities. According to the expectation hypothesis, forward interest rates should be unbiased estimates of expected future spot interest rates.
  • 3.1K
  • 09 Jan 2024
Topic Review
Australian Raven
The Australian raven (Corvus coronoides) is a passerine bird in the genus Corvus native to much of southern and northeastern Australia. Measuring 46–53 centimetres (18–21 in) in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs and feet. The upperparts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. The Australian raven is distinguished from the Australian crow species by its throat hackles, which are prominent in adult birds. Older adult individuals have white irises, younger adults have white irises with an inner blue rim, while younger birds have dark brown irises until fifteen months of age, and hazel irises with an inner blue rim around each pupil until age two years and ten months. Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827, its species name (coronoides) highlighting its similarity with the carrion crow (C. corone). Two subspecies are recognized, which differ slightly in calls and are quite divergent genetically. The preferred habitat is open woodland and transitional zones. It has adapted well to urban environments and is a common city bird in Sydney, Canberra, and Perth. An omnivorous and opportunistic feeder, it eats a wide variety of plant and animal material, as well as food waste from urban areas. In eastern Australia, its range is strongly correlated with the presence of sheep, and it has been blamed for killing lambs. However, this is very rare, and the raven most often scavenges for afterbirth and stillborn animals as well as newborn lamb faeces. The Australian raven is territorial, with pairs generally bonding for life. Breeding takes place between July and September, with almost no variation across its range. The nest is a bowl-shaped structure of sticks sited high in a tree, or occasionally in a man-made structure such as a windmill or other building. File:An audio recording of an Australian Raven (Corvus coronoides).wav
  • 3.1K
  • 21 Nov 2022
Topic Review
In-Wheel Motor Drive Systems for Electric Vehicles
There has been significant attention given to the electrification of transportation due to concerns about fossil fuel depletion and environmental pollution. Conventional drive systems typically include a clutch, reduction gear, and mechanical differential, which results in power loss, noise, vibration, and additional maintenance. However, in-wheel motor drive technology eliminates the need for these components, providing benefits such as higher system efficiency, improved wheel control, and increased passenger comfort.
  • 3.1K
  • 21 Aug 2023
Topic Review
Pegasus
Pegasus, the winged horse of Greek mythology, is a prominent constellation in the northern sky, known for its distinctive "Great Square" asterism. As one of the 48 constellations cataloged by the ancient Greek astronomer Ptolemy, Pegasus has a rich cultural and astronomical significance. Its association with the mythical creature Pegasus, ridden by heroes such as Perseus and Bellerophon, adds to its allure and makes it a captivating subject for stargazers.
  • 3.1K
  • 15 Mar 2024
Topic Review
Optical Biomedical Sensors
The optical biomedical sensor industry has grown enormously over the past few years and is expected to grow more in the forthcoming days because of the extensive need for point-of-care testing devices. Researchers all over the world are working on the implementation of highly sensitive, reliable, portable, and inexpensive biomedical appliances, which can revolutionize this market. Optical biosensing is a vast topic, and numerous optical sensing techniques have been presented over the years.These techniques and corresponding technological platforms enabling the manufacturing of optical biomedical sensors of different types.the most representative cases are integrated optical biosensors, vertical grating couplers, plasmonic sensors, surface plasmon resonance optical fiber biosensors, and metasurface biosensors, Photonic crystal-based biosensors, thin metal films biosensors, and fiber Bragg grating biosensors，these optical biomedical sensors might enable the identification of symptoms of deadly illnesses in their early stages; thus, potentially saving a patient’s life. 
  • 3.1K
  • 05 May 2021
  • Page
  • of
  • 2799
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