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Topic Review
Mechanism of Photocatalytic Water Splitting
The constant increase in the amount of energy consumed and environmental problems associated with the use of fossil fuels determine the relevance of the search for alternative and renewable energy sources. One of the most promising renewable fuels is hydrogen gas, which can be produced by sunlight-driven photocatalytic water splitting. The decisive role in the efficiency of the process is played by the properties of the photocatalyst. Oxide materials are widely used as photocatalysts due to their appropriate band structure, high-enough photochemical stability and corrosion resistance. However, the bandgap, crystallinity and the surface morphology of oxide materials are subject to improvement. In order to choose an appropriate oxide semiconductor photocatalytic material and strategies of its modification it is necessary to examine the mechanism of the photocatalytic water splitting.
  • 4.4K
  • 01 Aug 2022
Topic Review
Excavation (Archaeology)
In archaeology, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is a site being studied. Such a site excavation concerns itself with a specific archaeological site or a connected series of sites, and may be conducted over as little as several weeks to over a number of years. Numerous specialized techniques with particular features are used. Resources and other practical issues do not allow archaeologists to carry out excavations whenever and wherever they choose. These constraints mean many known sites have been deliberately left unexcavated. This is with the intention of preserving them for future generations as well as recognising the role they serve in the communities that live near them. Excavation involves the recovery of several types of data from a site. These data include artifacts (objects made or modified by humans), features (modifications to the site itself such as post molds, burials, and hearths), ecofacts (evidence for the local environment and resources being used such as snail shells, seeds, and butchered bones) and, most importantly, archaeological context (relationships among the other types of data). Ideally, data from the excavation should suffice to reconstruct the site completely in three-dimensional space. The presence or absence of archaeological remains can often be suggested by remote sensing, such as ground-penetrating radar. Basic information about the development of the site may be drawn from this work but the understanding of finer features usually requires excavation though appropriate use of augering.
  • 4.4K
  • 30 Nov 2022
Topic Review
Brahmanical System of Education
Brahmanical System of Education was an ancient system of education in ancient India. It was based on Vedic tradition.
  • 4.4K
  • 03 Apr 2023
Topic Review
Centrifugal Fan
A centrifugal fan is a mechanical device for moving air or other gases in a direction at an angle to the incoming fluid. Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink; such a fan is also called a blower, blower fan, biscuit blower, or squirrel-cage fan (because it looks like a hamster wheel). These fans increase the speed and volume of an air stream with the rotating impellers. Centrifugal fans use the kinetic energy of the impellers to increase the volume of the air stream, which in turn moves against the resistance caused by ducts, dampers and other components. Centrifugal fans displace air radially, changing the direction (typically by 90°) of the airflow. They are sturdy, quiet, reliable, and capable of operating over a wide range of conditions. Centrifugal fans are constant-displacement or constant-volume devices, meaning that, at a constant fan speed, a centrifugal fan moves a relatively constant volume of air rather than a constant mass. This means that the air velocity in a system is fixed even though the mass flow rate through the fan is not. Centrifugal fans are not positive-displacement devices and centrifugal fans have certain advantages and disadvantages when contrasted with positive-displacement blowers: centrifugal fans are more efficient, whereas positive-displacement blowers may have a lower capital cost. The centrifugal fan has a drum shape composed of a number of fan blades mounted around a hub. As shown in the animated figure, the hub turns on a driveshaft mounted in bearings in the fan housing. The gas enters from the side of the fan wheel, turns 90 degrees and accelerates due to centrifugal force as it flows over the fan blades and exits the fan housing.
  • 4.4K
  • 23 Oct 2022
Topic Review
List of Cities by Sunshine Duration
The following is a list of cities by sunshine duration. Sunshine duration is a climatological indicator, measuring duration of sunshine in given period (usually, a day or a year) for a given location on Earth, typically expressed as an averaged value over several years. It is a general indicator of cloudiness of a location, and thus differs from insolation, which measures the total energy delivered by sunlight over a given period. Sunshine duration is usually expressed in hours per year, or in (average) hours per day. The first measure indicates the general sunniness of a location compared with other places, while the latter allows for comparison of sunshine in various seasons in the same location. Another often-used measure is percentage ratio of recorded bright sunshine duration and daylight duration in the observed period. An important use of sunshine duration data is to characterize the climate of sites, especially of health resorts. This also takes into account the psychological effect of strong solar light on human well-being. It is often used to promote tourist destinations.
  • 4.4K
  • 03 Nov 2022
Topic Review
Polymer-Derived Ceramics
Ceramics derived from organic polymer precursors, which have exceptional mechanical and chemical properties that are stable up to temperatures slightly below 2000 °C, are referred to as polymer-derived ceramics (PDCs).
  • 4.4K
  • 09 Feb 2021
Topic Review
Biomechanical Factors in Track and Field Sprint Start
In athletics sprint events, the block start performance can be fundamental to the outcome of a race. Several biomechanical determinants of sprinters have been identified. In the “Set” position, an anthropometry-driven block setting facilitating the hip extension and a rear leg contribution should be encouraged. At the push-off, a rapid extension of both hips and greater force production seems to be important. After block exiting, shorter flight times and greater propulsive forces are the main features of best sprinters. 
  • 4.4K
  • 13 Apr 2022
Topic Review
Single-Zone HVAC Systems
Single-zone HVAC systems are installed in most residential buildings, which implies regulating all the rooms of the house with a single thermostat and with static ventilation registers.
  • 4.4K
  • 27 Oct 2020
Topic Review
Plagioclase
Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel (1796–1872) in 1826. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in the mineral's crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or 'record-groove' effect. Plagioclase is a major constituent mineral in the Earth's crust, and is consequently an important diagnostic tool in petrology for identifying the composition, origin and evolution of igneous rocks. Plagioclase is also a major constituent of rock in the highlands of the Moon. Analysis of thermal emission spectra from the surface of Mars suggests that plagioclase is the most abundant mineral in the crust of Mars. Its name comes from Ancient Greek plágios (πλάγιος 'oblique') + klásis ((κλάσις 'fracture'), in reference to its two cleavage angles.
  • 4.4K
  • 25 Nov 2022
Topic Review
Cell Lysis
Cell lysis is the first step of sample preparation for nucleic acid (NA) detection. Its purpose is to release NAs from the cells by disrupting the structure of cell membranes, which are also known as phospholipid bilayer membranes or plasmalemma. As NA detection typically relies on amplification using polymerase chain reaction (PCR) or isothermal alternatives, carry-over of inhibitory agents including the reagents used for lysis needs to be avoided or minimised. While washing steps are easily implemented in a laboratory setting, for Point of Need testing, the trend is towards substitution of strong inhibitory lytic reagents for more benign alternatives to minimise processing steps and reagent use. Additionally, sustainability of the reagents and their disposal are growing concerns. Here, an overview of lysis methods is provided from the perspective of their suitability for for point of need testing.
  • 4.4K
  • 16 Nov 2023
Topic Review
Nrf2 and Oxidative Stress
Organisms are continually exposed to exogenous and endogenous sources of reactive oxygen species (ROS) and other oxidants that have both beneficial and deleterious effects on the cell. ROS have important roles in a wide range of physiological processes; however, high ROS levels are associated with oxidative stress and disease progression. Oxidative stress has been implicated in nearly all major human diseases, from neurogenerative diseases and neuropsychiatric disorders to cardiovascular disease, diabetes, and cancer. Antioxidant defence systems have evolved as a means of protection against oxidative stress, with the transcription factor Nrf2 as the key regulator.
  • 4.4K
  • 01 Feb 2023
Topic Review
Effective Atomic Number
Effective atomic number has two different meanings: one that is the effective nuclear charge of an atom, and one that calculates the average atomic number for a compound or mixture of materials. Both are abbreviated Zeff.
  • 4.4K
  • 22 Nov 2022
Topic Review
Glucosinolate Biosynthesis
Glucosinolates are amino acid-derived plant-specialized metabolites that are largely found within the members of the family Brassicaceae, which includes vegetables such as broccoli, cabbage, and mustard, as well as the model plant Arabidopsis thaliana (thale cress). The aliphatic glucosinolates are derived from methionine, alanine, leucine, isoleucine, or valine; aromatic glucosinolates are built from phenylalanine or tyrosine; and the indole glucosinolates originate with tryptophan. Each of class of glucosinolate shares a core chemical structure consisting of a β-D-glucosyl residue linked to a (Z)-N-hydroximinosulfate ester through a sulfur and a variable amino acid-derived R group. To date, more than 130 glucosinolate molecules, of which Arabidopsis contains 40 mainly derived from methionine and tryptophan, have been described.
  • 4.4K
  • 11 Oct 2021
Topic Review
Main Cable's Construction Control Technology of Suspension Bridge
The main cable shape control confronts new challenges when a suspension bridge’s span exceeds two kilometers. As a suspension bridge’s primary load-bearing component, it is difficult to alter the alignment once the erection is completed. Hence, the accurate calculation and control of the main cable shape has significant scientific research value from various aspects. The erection error of the free cable shape will have a substantial impact on subsequent construction stages. Therefore, when erecting the main cable, it is essential to guarantee the shape’s precision to the greatest extent possible.
  • 4.4K
  • 06 Mar 2023
Topic Review
MMP-13 in Osteoarthritis Treatment
Osteoarthritis (OA) is a common degenerative disease characterized by the destruction of articular cartilage and chronic inflammation of surrounding tissues. Matrix metalloproteinase-13 (MMP-13) is the primary MMP involved in cartilage degradation through its particular ability to cleave type II collagen. Hence, it is an attractive target for the treatment of OA.
  • 4.4K
  • 07 May 2021
Biography
Robert Noyce
Robert Norton Noyce (December 12, 1927 – June 3, 1990), nicknamed "the Mayor of Silicon Valley," was an American physicist who co-founded Fairchild Semiconductor in 1957 and Intel Corporation in 1968. He is also credited (along with Jack Kilby) with the realization of the first integrated circuit or microchip that fueled the personal computer revolution and gave Silicon Valley its name.[1][2]
  • 4.4K
  • 08 Dec 2022
Topic Review
A Certain Magical Index
A Certain Magical Index (Japanese: とある魔術の禁書目録 (インデックス), Hepburn: Toaru Majutsu no Indekkusu)[lower-alpha 1] is a Japanese light novel series written by Kazuma Kamachi and illustrated by Kiyotaka Haimura, which has been published by ASCII Media Works under their Dengeki Bunko imprint since April 2004. The plot is set in a world where supernatural abilities exist. The light novels focus on Toma Kamijo, a young high school student in Academy City who has an unusual ability, as he encounters an English nun named Index. His ability and relationship with Index proves dangerous to other sorcerers and Espers who want to discover the secrets behind him and Index, as well as the city. Yen Press have licensed the novels in North America. A manga adaptation by Chuya Kogino began serialization in Monthly Shōnen Gangan from May 2007. J.C.Staff produced two 24-episode anime series between 2008 and 2011. An animated film was released in February 2013. The anime adaptations are licensed in North America by Funimation. A 26-episode third season aired between 2018 and 2019, licensed by Funimation. The side-story manga series, A Certain Scientific Railgun, began serialization in Dengeki Daioh in February 2007. A second side-story manga series, A Certain Scientific Accelerator, began serialization in Dengeki Daioh in December 2013.
  • 4.4K
  • 19 Oct 2022
Topic Review
Precooling and Cold Storage for Fruits and Vegetables
Cold chain systems, such as cold storages, are crucial to minimizing postharvest losses of fresh fruits and vegetables. Cold storage alone cannot prevent crop losses, but should be considered as one component that needs to be integrated into a cold chain network from the point of harvest to the point of purchase by the consumer. Cold chains are still in their infancy in developing countries due to the lack of basic infrastructure and management skills needed to support the development of integrated cold chain systems.
  • 4.4K
  • 08 Sep 2022
Topic Review
Intraretinal Fluid Pattern Characterization
The accumulation of fluids in the retinal layers is one of the main causes of blindness in developed countries. The main strategy for its study and diagnosis is through the use of Optical Coherence Tomography (OCT) images. This allows experts to observe the layers of the retina in a cross-sectional view. Commonly, for the analysis of these accumulations by means of computer diagnostic support systems, precise segmentation strategies are employed.
  • 4.4K
  • 22 Apr 2021
Topic Review
Plasma electrolytic oxidation
Plasma electrolytic oxidation (PEO) is a promising method for the surface treatment of metals. The procedure takes place within passivating aqueous electrolytes under alternating current patterns and high process voltages. In so far suitable treatment parameters are chosen, this leads to the formation of protective ceramic coatings which technological properties can be adjusted within wide ranges. The article gives an brief introduction to this topic, concerning a historical overview and a summary of the application fields as well as the layer forming mechanisms and parameter dependencies of this process.
  • 4.4K
  • 21 Jul 2020
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