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Topic Review
Electroactive Polymers
Electroactive polymers (EAPs) are a versatile class of electrically deformable polymers. These polymers have the ability to deform when excited by electrical potentials due to their inherent electro-mechanical properties. The piezoelectric couplings in EAPs provide them with unique capabilities that are of significant interest in actuators and soft robotics.
  • 4.6K
  • 12 Oct 2021
Topic Review
Water-Soluble Photoinitiators in Biomedical Applications
Light-initiated polymerization processes are currently an important tool in various industrial fields. The advancement of technology has resulted in the use of photopolymerization in various biomedical applications, such as the production of 3D hydrogel structures, the encapsulation of cells, and in drug delivery systems. The use of photopolymerization processes requires an appropriate initiating system which, in biomedical applications, must meet additional criteria: high water solubility, non-toxicity to cells, and compatibility with visible low-power light sources. This article is a literature review on those compounds that act as photoinitiators of photopolymerization processes in biomedical applications. The division of initiators according to the method of photoinitiation was described and the related mechanisms were discussed. Examples from each group of photoinitiators are presented, and their benefits, limitations and applications are outlined.
  • 4.6K
  • 10 Jun 2020
Topic Review
The NIST World Trade Center Disaster Investigation
The National Construction Safety Team Act (NCST Act), signed into law on October 1, 2002 by President George W. Bush, mandated the National Institute of Standards and Technology (NIST) to establish the likely technical cause or causes of the three building failures that occurred on September 11, 2001 at the World Trade Center as a result of a terrorist attack. NIST issued its final report on the collapse of the World Trade Center Twin Towers in September 2005. It issued its final report on 7 World Trade Center in November 2008. NIST concluded that the collapse of each tower resulted from the combined effects of airplane impact damage, widespread fireproofing dislodgment, and the fires that ensued. The sequence of failures that NIST concluded initiated the collapse of both towers involved the heat-induced sagging of floor trusses pulling some of the exterior columns on one side of each tower inward until they buckled, after which instability rapidly spread and the upper sections then fell onto the floors below. World Trade Center Building 7 (7WTC), which was never directly hit by an airplane, collapsed as a result of thermal expansion of steel beams and girders that were heated by uncontrolled fires caused by the collapse of the North Tower and failure of the fire-resistive material.
  • 4.6K
  • 24 Nov 2022
Topic Review
CO2 and H2S Separation Technologies
The emerging economic activities, modernization of technology and progressive transition from coal utilization to low-carbon fuel drive the rising energy demand. Natural gas is well-known as clean energy resources for electricity generation and fuel for transportation. Currently, CO2 and H2S content in gas fields accounts for up to 90% and 15%, respectively. Apart from fulfilling the market demand, the removal of these contaminants from natural gas is critical due to their corrosive natures, low heating value of natural gas and  greenhouse gas effect. To date, numerous gas fields remain unexplored due to high presence of contaminants. Several technologies such as absorption, adsorption, membrane separation and cryogenic distillation have been developed for natural gas sweetening. This entry comprehensively discussed the mechanisms and state-of-the-art of these conventional technologies.
  • 4.6K
  • 03 Mar 2022
Topic Review
Copper in the Human Body
Copper, an essential trace element found in the brain, liver, and kidneys, enables the body to form red blood cells, maintain bone health, and can help prevent cardiovascular disease and osteoporosis. Copper is also a key element in maintaining lung function as it plays a vital role in metabolic processes such as cellular respiration.
  • 4.6K
  • 26 Jan 2021
Topic Review
Recognition Technologies of Hand Gesture
Hand gesture recognition plays a significant part in delivering diverse messages using hand gestures in the digital domain. Real-time hand gesture identification is now possible because of advancements in both imaging technology and image processing algorithmic frameworks.
  • 4.6K
  • 17 Jun 2022
Topic Review
Mashrabiya’s Impact on Energy Efficiency and Cultural Aspects
The traditional and indigenous architecture in Saudi Arabia is being replaced by modern, Western-style buildings, resulting from the growing influence of Western culture. This change is evident in architectural elements such as Mashrabiya, which was once a symbol of the country’s Islamic architecture.
  • 4.6K
  • 17 Jul 2023
Topic Review
PragerU
PragerU, short for Prager University, is an American non-profit organization that creates videos on various political, economic and philosophical topics from an American conservative or right-wing perspective. The organization was co-founded by talk show host and writer Dennis Prager and Allen Estrin. The videos are posted on YouTube and usually feature a speaker who lectures for about five minutes. The organization relies on donations, and much of its early funding came from fracking billionaires Dan and Farris Wilks. PragerU is not a university or academic institution. It does not hold classes, does not grant certifications or diplomas, and is not accredited by any recognized body.
  • 4.6K
  • 11 Nov 2022
Topic Review
AuNPs
Gold nanoparticles (AuNPs) have gained high prominence in the biomedicine field, due to their own physico-chemical properties that are suitable for different imaging or therapeutic uses, versatile structural modification, including easy functionalization of their surface with different chemical entities (e.g., chelators, targeting biomolecules or cytotoxic drugs), favourable biological half-life, low toxicity and biocompatibility. In particular, the use of AuNPs in radiopharmaceutical development has provided various nanometric platforms for the delivery of medically relevant radioisotopes for SPECT/PET diagnosis and/or radionuclide therapy
  • 4.6K
  • 20 Jan 2021
Topic Review
DPPH· Stable Free Radical
DPPH· is 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl stable free radical. It was discovered in 1922.
  • 4.6K
  • 24 Feb 2021
Topic Review
Liquid versus Solid Consumption
Sharing economy is nowadays a particularly important facet of modern society. It is driven by digitalization that allows firms to interact with their customers on a daily basis by the need of reducing the environmental impact of both companies and individual actions and by the growing consciousness for environment that consumers are developing day by day. New models of consumption, such as the liquid one, are becoming very frequent, shaping countries’ productive systems and consumers’ habits.
  • 4.6K
  • 23 Dec 2021
Topic Review
AI-Based and Big Data Analytics on Urban Planning
In order to enable a holistic approach to design and planning, there is a need to integrate those data sources and combine them with other more traditional methods of urban assessment. At the same time, there are still various concerns about big data analytics based on AI-related tools connected, for example, with the accessibility to and accuracy of big data, as well as the limitations of different types of AI-based tools which do not permit this kind of analytics to fully replace traditional urban planning analyses. In terms of technological change, the application of big data in design and planning may greatly support traditional planning methods and provide conditions for innovation; however, due to its limitations, it can only enrich but in no way replace traditional urban studies.
  • 4.6K
  • 03 Dec 2021
Topic Review
Teak
Scientific name:  Tectona grandis L. Family: Verbenaceae  Centre of origin: India Common name: Sagwan, Tekku, Saguna, Saga The generic name comes from ‘tekka’, the Malabar name for T. grandis. The specific name, ‘grandis’, is Latin for ‘large’ or ‘great’.
  • 4.6K
  • 08 Feb 2022
Topic Review
Ultra-High-Purity Aluminum
Properties of high-purity aluminum are the low magnetic permeability, the absence of low-temperature brittleness, as well as the increased strength and plasticity at low temperatures. These explain the classical application of high- to ultra-high-purity aluminum for the stabilization of superconductors running at cryogenic temperatures as low as −269 °C.
  • 4.6K
  • 01 Nov 2021
Topic Review
Retrofitting and Strengthening of Structures
In civil engineering since antiquity, structural repair has been a very particular problem. Throughout history, human-constructed buildings have been destroyed due to time, natural disasters, and even building mistakes. In this respect, the field of engineering related to structural reconstruction and recovery seeks to identify methods and techniques to accomplish this important task. The pace of the degradation of concrete buildings throughout the world is frightening. It has now been verified that even if the structural design complies with all particular building code criteria such as concrete quality, cover, and so on, there is still an acceptable high risk of concrete degradation and reinforcing corrosion. Steel corrosion has been identified as the most severe cause of reinforced concrete degradation, capable of causing fractures, spalling the concrete cover, reducing the effective c/s area of the reinforcement, and ultimately leading to collapse. In order to repair and rehabilitate other buildings, this study sought to compile the main ideas, methods, and technologies used by these influential engineers. In fact, this report contains case studies on functional restoration. The document further addresses various types of building, such as pre-stressing, post-tensioning, deployment, and pre-stressing.
  • 4.6K
  • 24 Dec 2022
Topic Review
Atmospheric Correction for Landsat 8
Ocean colour (OC) remote sensing is important for monitoring marine ecosystems. However, inverting the OC signal from the top-of-atmosphere (TOA) radiance measured by satellite sensors remains a challenge as the retrieval accuracy is highly dependent on the performance of the atmospheric correction as well as sensor calibration. In this study, the performances of four atmospheric correction (AC) algorithms, the Atmospheric and Radiometric Correction of Satellite Imagery (ARCSI), Atmospheric Correction for OLI ‘lite’ (ACOLITE), Landsat 8 Surface Reflectance (LSR) Climate Data Record (Landsat CDR), herein referred to as LaSRC (Landsat 8 Surface Reflectance Code), and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) Data Analysis System (SeaDAS), implemented for Landsat 8 Operational Land Imager (OLI) data, were evaluated. The OLI-derived remote sensing reflectance (Rrs) products (also known as Level-2 products) were tested against near-simultaneous in-situ data acquired from the OC component of the Aerosol Robotic Network (AERONET-OC). Analyses of the match-ups revealed that generic atmospheric correction methods (i.e., ARCSI and LaSRC), which perform reasonably well over land, provide inaccurate Level-2 products over coastal waters, in particular, in the blue bands. Between water-specific AC methods (i.e., SeaDAS and ACOLITE), SeaDAS was found to perform better over complex waters with root-mean-square error (RMSE) varying from 0.0013 to 0.0005 sr−1 for the 443 and 655 nm channels, respectively. An assessment of the effects of dominant environmental variables revealed AC retrieval errors were influenced by the solar zenith angle and wind speed for ACOLITE and SeaDAS in the 443 and 482 nm channels. Recognizing that the AERONET-OC sites are not representative of inland waters, extensive research and analyses are required to further evaluate the performance of various AC methods for high-resolution imagers like Landsat 8 and Sentinel-2 under a broad range of aquatic/atmospheric conditions.
  • 4.6K
  • 30 Oct 2020
Topic Review
Wireless Sensor Network
Wireless Sensor Network (WSN) is one of the most effective methods for many real-time applications, due to its compactness, cost-effectiveness, and ease of deployment. The function of the WSN is to monitor the field of interest, collect the data, and transmit it to the base station (Access point) for post-processing analysis.
  • 4.6K
  • 21 Jul 2022
Topic Review
High-Speed Train Noise Control Methods
The sound of trains is considered a disturbance to most residents around the railroad and train passengers, and the sound generated by trains can interfere with sleep, life, and work. With increases in train speed, the main noise from high-speed trains has changed from rolling noise to aerodynamic noise, and the noise level and noise frequency range have also changed significantly. The current methods of noise reduction for trains are discussed.
  • 4.6K
  • 09 Aug 2022
Topic Review
Indian Regional Navigation Satellite System
The Indian Regional Navigation Satellite System (IRNSS), with an operational name of NAVIC (acronym for NAVigation with Indian Constellation; also, nāvik 'sailor' or 'navigator' in Sanskrit, Hindi, and many other Indian languages), is an autonomous regional satellite navigation system that provides accurate real-time positioning and timing services. It covers India and a region extending 1,500 km (930 mi) around it, with plans for further extension. An extended service area lies between the primary service area and a rectangle area enclosed by the 30th parallel south to the 50th parallel north and the 30th meridian east to the 130th meridian east, 1,500–6,000 km (930–3,730 mi) beyond borders. The system currently consists of a constellation of seven satellites, with two additional satellites on ground as stand-by. The constellation is in orbit as of 2018, and the system was expected to be operational from early 2018 after a system check. NAVIC will provide two levels of service, the "standard positioning service", which will be open for civilian use, and a "restricted service" (an encrypted one) for authorised users (including the military). NAVIC is planned to become available for civilian use in the first half of 2020. There are plans to expand the NAVIC system by increasing its constellation size from 7 to 11.
  • 4.6K
  • 12 Oct 2022
Topic Review
CRISPR-Cas9-Based Genome Engineering in Animals
Genetic engineering and transgenesis provide the opportunity for more significant gains and production in a short span of time. One of the best strategies is the genetic alteration of livestock to enhance the efficiency of food production (e.g., meat and milk), animal health, and welfare (animal population and disease). Moreover, genome engineering in the bovine is majorly focused on subjects such as disease resistance (e.g., tuberculosis), eradicate allergens (e.g., beta-lactoglobulin knock-out), products generation (e.g., meat from male and milk from female), male or female birth specifically (animal sexing), the introduction of valuable traits (e.g., stress tolerance and disease resistance) and their wellbeing (e.g., hornlessness).
  • 4.6K
  • 22 Oct 2021
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