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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
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
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
Graphene-Coating for Efficient Electronics Cooling
Thermal management is essential in electronics, as it improves reliability and enhances performance by removing heat generated by the devices. Thermal management of handheld systems such as laptops is becoming increasingly challenging due to increasing power dissipation. The power dissipated per unit area on the laptop electronic chips is increasing while the area of the chips itself it decreasing, resulting a high heat flux that causes an increase in temperature. The increasing temperature adversely affects the performance of laptops and in many cases leads to failure through such modes as thermal fatigue and dielectric breakdown. In this work, three dimensional steady state CFD model of a laptop motherboard is presented. The model accounts for heat transfer for both natural convection and radiation to the ambient air temperature. The present CFD study allow accurate, rapid, physical modelling to make decisions on materials, components and layout beside power control feedback to achieve performance and target lifetime with reduced testing requirements. An alternative design for the cooling of laptop microprocessor using only passive cooling is proposed. The results showed that the assembled a thin plate of a copper material coated with graphene and use it as a heat sinks with the microprocessor of the laptop providing an efficient and economical solution in thermal management. Considerable drop in microprocessor temperature is obtained through the heat dissipation path suggested in the new design. The proposed passive cooling solution has the advantages of fanless operation compared to the existing active cooling solutions such as the noise-free operation, lower energy consumption and higher reliability. We hope this work may open the way for huge boost in the technology of electric cooling by innovative manufacturing techniques.
  • 4.6K
  • 28 Oct 2020
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
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
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
Glory
Glory (from the Latin gloria, "fame, renown") is used to describe the manifestation of God's presence as perceived by humans according to the Abrahamic religions. Divine glory is an important motif throughout Christian theology, where God is regarded as the most glorious being in existence, and it is considered that human beings are created in the Image of God and can share or participate, imperfectly, in divine glory as image-bearers. Thus Christians are instructed to "let your light shine before men, that they may see your good works, and glorify your Father in heaven".
  • 4.6K
  • 30 Nov 2022
Biography
Avi Loeb
Abraham "Avi" Loeb (Hebrew: אברהם (אבי) לייב‎; born February 26, 1962) is an Israeli-United States theoretical physicist who works on astrophysics and cosmology. Loeb is the Frank B. Baird Jr. Professor of Science at Harvard University. He had been the longest serving Chair of Harvard's Department of Astronomy (2011–2020), Founding Director of Harvard's Black Hole Initiative (sin
  • 4.6K
  • 17 Nov 2022
Topic Review
The Heart of Borneo
The HoB is situated in Borneo, the third-largest island in the world next to Greenland and New Guinea. It is shared by Indonesia (Kalimantan) covering an area of 745,567 square kilometers (km2), Borneo Malaysia, comprising the states of Sarawak and Sabah with an area of 124,449 km2 and 73,711 km2, respectively, and a small-nation sate, Brunei Darussalam (5765 km2). The rainforests in Borneo, which evolved between 100 and 150 million years ago, are among the most biologically diverse on Earth. Representing just one percent of the earth’s terrestrial surface, the island of Borneo holds about six percent of the world’s plant and animal species. There are approximately 15,000 flowering plants and 3000 species of trees found in Borneo’s forest, including 6000 endemic species. The biologically diverse island is recognized as a globally significant biodiversity ‘hotspot’. In addition, the uplands of Borneo are a source of at least 14 of the 20 major rivers on the island. Thus, environmentally sustainable resource management is critically important in maintaining the ecological health of riverine systems, which underpin the socio-economic progress of 17 million people in Borneo.
  • 4.6K
  • 23 Sep 2021
Topic Review
Heavy-Duty Vehicle Powertrain Technologies
Battery electric heavy-duty diesel vehicles (HDVs) and hydrogen fuel cell HDVs are two available alternatives to diesel engines. Each diesel engine HDV, battery-electric HDV, and hydrogen fuel cell HDV powertrain has its own advantages and disadvantages. 
  • 4.6K
  • 17 Jun 2021
Topic Review Peer Reviewed
Unpacking Transdisciplinary Research Scenarios in Architecture and Urbanism
Research in architecture and urbanism is a complex undertaking. It involves a multitude of challenges, approaches, variables, diverse scales, and types of environments to examine. This entry dives into the complexities of architectural and urban research and explores the integration of diverse approaches into various research topics or domains. Recognizing the dynamic interplay of human, cultural, technological, and environmental factors in architecture and urbanism, it proposes a transdisciplinary approach to bridge existing disciplinary and methodological boundaries. This entry adopts and operationalizes a comprehensive approach that encompasses hybrid scenario development, integrated socio-spatial analysis, a revised experiential approach, and the integration of environmental psychology into architectural and urban studies. These components are envisioned to harmonize various methodologies and to depict a picture of what research in architecture and urbanism could be within an identified set of domains. This approach is grounded in a rigorous literature review, empirical evidence, and relevant validation through case studies. The application of this approach instigates a series of research scenarios which act as frameworks that provide new insights into design and practice-based research, building anatomy research, city dynamics research, housing dynamics research, and user perception studies. Each scenario demonstrates the applicability of combining theoretical insights with empirical investigations. The implications of these scenarios for architectural and urban research emphasize the significance of transdisciplinarity and highlights the importance of integrating diverse theoretical tenets and methodological insights to address the complex challenges of research in architecture and urbanism.
  • 4.6K
  • 20 Feb 2024
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
Genome Organization
In higher-order organisms, the genome is assembled into a protein-dense structure called chromatin. Chromatin is spatially organized in the nucleus through hierarchical folding, which is tightly regulated both in cycling cells and quiescent cells. Assembly and folding are not one-time events in a cell’s lifetime; rather, they are subject to dynamic shifts to allow changes in transcription, DNA replication, or DNA damage repair.  Chromatin is regulated at many levels and recent tools have permitted the elucidation of specific factors involved in the maintenance and regulation of the three-dimensional (3D) genome organization.
  • 4.6K
  • 14 Apr 2021
Topic Review Peer Reviewed
William II of Hauteville (1171-1189)
William II of Hauteville King of Sicily (1171–1189). William II of Hauteville was the third king of the Norman dynasty on the throne of Sicily. He ruled independently from 1171 (from 1166 to 1171 he was under the regency of his mother) to 1189. From an iconographic point of view, he is particularly interesting because he was the first king of Sicily who made use of monumental images of himself. In particular, we have five official (namely, commissioned directly by him or his entourage) representations of him: the royal bull, the royal seal, and three images from the Cathedral of Monreale (near Palermo): two mosaic panels and one carved capital.
  • 4.6K
  • 18 Apr 2022
Topic Review
Nitrogen Compounds in the Soil
Soil is an important environment in which nitrogen is transformed. The nitrogen cycle in the soil depends on microorganisms, without them, nitrogen transformation processes cannot occur. They determine the continuity of the circulation of this element in the environment and ensure the renewal of its resources. The presence of microorganisms involved in nitrogen transformation in the soil, their activity and the intensity of the reactions taking place are influenced by many factors, including the type of soil, moisture, oxygenation, pH, vegetation and fertilization. 
  • 4.6K
  • 31 May 2021
Topic Review
Coal Fly Ash Use in Cement and Concrete
Nowadays, coal is increasingly being used as an energy source in some countries. This coal-fired generation process, however, has the disadvantage that produces large quantities of coal fly ash. Its characteristics differ depending on the combustion conditions and the coal source. Fineness will influence early compressive strength in cement-based materials. The finer the binding material, the higher the early compressive strength. They can be used to produce high-volume fly ash (HVFA) concrete, self-compacting concrete (SCC), concrete for marine infrastructures, pervious concrete, roller compacted concrete (RCC) and so on.
  • 4.6K
  • 14 Dec 2021
Topic Review
Parabolic Aluminized Reflector Light
A parabolic aluminized reflector lamp (also PARCAN light, PARcan, or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. Usage includes locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights ("cans" in the United States). They are identical in principle to sealed beam automobile headlights. The lamps and their fixtures are widely used in theatre, concerts and motion picture production when a substantial amount of flat lighting is required for a scene. In situations where sunlight or other specular light is available, a white foam reflector is often used to accomplish the same effect as a PAR array. PAR cans are being replaced in some stage applications by LED PAR cans, which use less electric power and produce a wide array of saturated colors without the use of color filters, when white light is not needed.
  • 4.6K
  • 18 Oct 2022
Topic Review
Honey in Treatment of COVID-19 Infection
The emergence of COVID-19, caused by the SARS-CoV-2 virus, led to the pursuit of solutions for the treatment of symptoms and/or disease. Honey has proven to be effective against viral infections, principally due to its potential antioxidant and anti-inflammatory activities that attenuate oxidative damage induced by pathogens, and by improving the immune system.
  • 4.6K
  • 22 Aug 2022
Topic Review
Active Front-End Rectifiers in EV DC Charging Applications
Active Front-End (AFE) rectifiers have regained momentum as the demand for highpower Electric Vehicle (EV) charging infrastructure increases exponentially. AFE rectifiers have high efficiency and reliability, and they minimize the disturbances that could be generated due to the operation of the EV charging systems by reducing harmonic distortion and operating close to the Unity Power Factor (UPF).
  • 4.6K
  • 05 May 2023
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