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Topic Review
Seawater Electrolysis
Hydrogen energy, as a clean and renewable energy, has attracted much attention in recent years. Water electrolysis via the hydrogen evolution reaction at the cathode coupled with the oxygen evolution reaction at the anode is a promising method to produce hydrogen. Given the shortage of freshwater resources on the planet, the direct use of seawater as an electrolyte for hydrogen production has become a hot research topic. Direct use of seawater as the electrolyte for water electrolysis can reduce the cost of hydrogen production due to the great abundance and wide availability. Various high-efficiency electrocatalysts have made great progress in seawater splitting and have shown great potential.
  • 1.9K
  • 07 Feb 2022
Topic Review
Geology of the Himalaya
The geology of the Himalayas is a record of the most dramatic and visible creations of the immense mountain range formed by plate tectonic forces and sculpted by weathering and erosion. The Himalayas, which stretch over 2400 km between the Namcha Barwa syntaxis at the eastern end of the mountain range and the Nanga Parbat syntaxis at the western end, are the result of an ongoing orogeny — the collision of the continental crust of two tectonic plates, namely, the Indian Plate thrusting into the Eurasian Plate. The Himalaya-Tibet region supplies fresh water for more than one-fifth of the world population, and accounts for a quarter of the global sedimentary budget. Topographically, the belt has many superlatives: the highest rate of uplift (nearly 10 mm/year at Nanga Parbat), the highest relief (8848 m at Mt. Everest Chomolangma), among the highest erosion rates at 2–12 mm/yr, the source of some of the greatest rivers and the highest concentration of glaciers outside of the polar regions. This last feature earned the Himalaya its name, originating from the Sanskrit for "the abode of the snow". From south to north the Himalaya (Himalaya orogen) is divided into 4 parallel tectonostratigraphic zones and 5 thrust faults which extend across the length of Himalaya orogen. Each zone, flanked by the thrust faults on its north and south, has stratigraphy (type of rocks and their layering) different from the adjacent zones. From south to north, the zones and the major faults separating them are the Main Frontal Thrust (MFT), Subhimalaya Zone (also called Sivalik), Main Boundary Thrust (MBT), Lesser Himalaya (further subdivided into the "Lesser Himalayan Sedimentary Zone (LHSZ) and the Lesser Himalayan Crystalline Nappes (LHCN)), Main Central thrust (MCT), Higher (or Greater) Himalayan crystallines (HHC), South Tibetan detachment system (STD), Tethys Himalaya (TH), and the Indus‐Tsangpo Suture Zone (ISZ). North of this lies the transhimalaya in Tibet which is outside the Himalayas. Himalaya has Indo-Gangetic Plain in south, Pamir Mountains in west in Central Asia, and Hengduan Mountains in east on China–Myanmar border. From east to west the Himalayas are divided into 3 regions, Eastern Himalaya, Central Himalaya, and Western Himalaya, which collectively house several nations and states.
  • 1.9K
  • 05 Dec 2022
Topic Review
Attention Mechanism for Remote Sensing
Machine learning, particularly deep learning (DL), has become a central and state-of-the-art method for several computer vision applications and remote sensing (RS) image processing. Researchers are continually trying to improve the performance of the DL methods by developing new architectural designs of the networks and/or developing new techniques, such as attention mechanisms. Since the attention mechanism has been proposed, regardless of its type, it has been increasingly used for diverse RS applications to improve the performances of the existing DL methods.
  • 1.9K
  • 24 Nov 2021
Topic Review
Agriculture in Ancient Mesopotamia
Agriculture was the main economic activity in ancient Mesopotamia. Operating under harsh constraints, notably the arid climate, the Mesopotamian farmers developed effective strategies that enabled them to support the development of the first states, the first cities, and then the first known empires, under the supervision of the institutions which dominated the economy: the royal and provincial palaces, the temples, and the domains of the elites. They focused above all on the cultivation of cereals (particularly barley) and sheep farming, but also farmed legumes, as well as date palms in the south and grapes in the north. In reality, there were two types of Mesopotamian agriculture, corresponding to the two main ecological domains, which largely overlapped with cultural distinctions. The agriculture of southern or Lower Mesopotamia, the land of Sumer and Akkad, which later became Babylonia received almost no rain and required large scale irrigation works which were supervised by temple estates, but could produce high returns. The agriculture of Northern or Upper Mesopotamia, the land that would eventually become Assyria, had enough rainfall to allow dry agriculture most of the time so that irrigation and large institutional estates were less important, but the returns were also usually lower.
  • 1.9K
  • 02 Dec 2022
Topic Review
Aromatic Water Pollutants
In recent years, the intensification of human activities including rapid urbanization, industrialization, population, and economic growth, led to an increase in waste production and energy demand. Most importantly such activities pose concerns for health, energy security and climate changes. Hazardous volatile organic compounds, VOC, and aromatic organic compounds, AOC, are being generated from the activities of many vital industries like mining and petrochemicals. They are instrumental in the economic growth of many countries and their products are regarded as privileges to modern communities. Nevertheless, they are toxic and carcinogenic thus, these wastes have been classified as “hazardous”. The simultaneous treatment of organic pollutants and energy recovery is an attractive solution to reduce pollution in water, air, and soil as well as provide alternative clean energy sources. Hydrogen could be generated from organic pollutants in water through photocatalysis. Photocatalysis refers to the oxidation and reduction, redox, reactions on semiconductor surfaces, mediated by the valence band holes and conduction band electrons, which are generated by the absorption of ultraviolet or visible light radiation. Compared to traditional oxidation processes, photocatalytic redox reaction operates at ambient conditions without a high temperature or high pressure, and many recalcitrant organic contaminants can be degraded without the addition of chemical oxidants, hence it is fully green process. Among the various photocatalysts, TiO2, as the most widely employed “golden” photocatalyst, has been largely used in photocatalysis, due to its chemical stability, nontoxicity, and low cost. In the last two decades, TiO2 photocatalysis has expanded very quickly, having undergone various development‐related energy issues and environmental issues, such as direct solar H2O splitting into H2 and the decomposition of pollutants in air and H2O at low concentrations. Although great progress has been made in TiO2 photocatalysis, much remains unknown, which raises an interesting challenge not only for engineers but also for basic scientists. a typical photocatalytic reaction in TiO2 photocatalysis contains many fundamental processes, including charge carrier formation, separation, relaxation, trapping, transfer, recombination, and transportation.
  • 1.9K
  • 24 May 2021
Topic Review
Rockfall
A rockfall is defined as the “detachment, fall, rolling, and bouncing of rock fragments. It may occur singly or in clusters, but there is little dynamic interaction between the most mobile moving fragments, which interact mainly with the substrate (path)".
  • 1.9K
  • 04 Aug 2021
Topic Review
Leaf area index (LAI)
Leaf area index (LAI) is an important vegetation leaf structure parameter in forest and agricultural ecosystems. Remote sensing techniques can provide an effective alternative to field-based observation of LAI. Different system configurations (passive, active, and multisource sensors on different collection platforms) has been used to estimate forest and crop LAI. The ease of use of empirical models supports these as the preferred choice for forest and crop LAI estimation. In terms of scale issues, both spectral and spatial scales impact the estimation of LAI. Uncertainty coming from various sources results in reduced accuracy in estimating LAI. 
  • 1.9K
  • 26 Oct 2020
Topic Review
Removal of Inorganic Nitrogen from Wastewater
Water contamination due to various nitrogenous pollutants generated from wastewater treatment plants is a crucial and ubiquitous environmental problem nowadays. Nitrogen contaminated water has manifold detrimental effects on human health as well as aquatic life. Consequently, various biological and bioelectrochemical treatment processes are employed to transform the undesirable forms of nitrogen in wastewater to safer ones for subsequent discharge.
  • 1.8K
  • 27 May 2022
Topic Review
French Geodesic Mission
The French Geodesic Mission (also called the Geodesic Mission to Peru, Geodesic Mission to the Equator and the Spanish-French Geodesic Mission) was an 18th-century expedition to what is now Ecuador carried out for the purpose of measuring the roundness of the Earth and measuring the length of a degree of latitude at the Equator. The mission was one of the first geodesic (or geodetic) missions carried out under modern scientific principles, and the first major international scientific expedition.
  • 1.8K
  • 19 Oct 2022
Topic Review
Benefits of Green Building Implementation
A green building is often defined as an energy-saving building, ecological building or sustainable building. Green buildings have higher commercial value compared to traditional buildings, due to the perceived low carbon emissions, energy savings, and maximized economic benefits throughout the life cycle.
  • 1.8K
  • 15 Nov 2022
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