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Topic Review
Archimedes Screw Turbines
Archimedes Screws Turbines (ASTs) are a new form of generators for small hydroelectric powerplants that could be applied even in low head sites. ASTs offer a clean and renewable source of energy. They are safer for wildlife and especially fish. The low rotation speed of ASTs reduces negative impacts on aquatic life and fish. Considering the flexibility and advantages of ASTs, they offer economic, social, and environmental advantages to support sustainable development to: - Increase the number of suitable sites and maximize power generation.- Retrofit old dams or upgrade current dams or mills to make them economically (power generation) and environmentally (renewable energy) reasonable.- Reduce the hydroelectricity major operational and/or maintenance costs.- Reduce the disturbance of natural erosion and sedimentation processes.- Make hydropower generation safer for aquatic wildlife, especially for fish.- Generate electricity for small communities, developing countries, and regions with limited access to the power grid or other infrastructures, or regions that are hard to access or connect to the power grid.  
  • 3.0K
  • 12 Jan 2022
Topic Review
Weichselian Glaciation
Weichselian glaciation[upper-alpha 1] refers to the last glacial period and its associated glaciation in northern parts of Europe. In the Alpine region it corresponds to the Würm glaciation. It was characterized by a large ice sheet (the Fenno-Scandian ice sheet) that spread out from the Scandinavian Mountains and extended as far as the east coast of Schleswig-Holstein, the March of Brandenburg and Northwest Russia. In Northern Europe it was the youngest of the glacials of the Pleistocene ice age. The preceding warm period in this region was the Eemian interglacial. The last cold period began about 115,000 years ago and ended 11,700 years ago. Its end corresponds with the end of the Pleistocene epoch and the start of the Holocene. The German geologist Konrad Keilhack (de) (1858-1944) named Weichselian glaciation using the German-language name (Weichsel) of the River Vistula (Polish: Wisła) in present-day Poland.
  • 3.0K
  • 14 Oct 2022
Topic Review
Climate Oscillation
A climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate, and is a type of climate pattern. These fluctuations in atmospheric temperature, sea surface temperature, precipitation or other parameters can be quasi-periodic, often occurring on inter-annual, multi-annual, decadal, multidecadal, century-wide, millennial or longer timescales. They are not perfectly periodic and a Fourier analysis of the data does not give a sharp spectrum. A prominent example is the El Niño Southern Oscillation, involving sea surface temperatures along a stretch of the equatorial Central and East Pacific Ocean and the western coast of tropical South America, but which affects climate worldwide. Records of past climate conditions are recovered through geological examination of proxies, found in glacier ice, sea bed sediment, tree ring studies or otherwise.
  • 3.0K
  • 09 Nov 2022
Topic Review
ESG Measurement
Investors are currently obliged to take environment, social, and governance (ESG) issues into consideration as part of their fiduciary duty. As such, it becomes increasingly important to identify sustainable investments that also hold financial value. A sector where this is especially underdeveloped is real estate.
  • 3.0K
  • 01 Apr 2021
Topic Review
Great Oxygenation Event
The Great Oxygenation Event, the beginning of which is commonly known in scientific media as the Great Oxidation Event (GOE, also called the Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust, Oxygen Revolution, or Great Oxidation) was the biologically induced appearance of dioxygen (O2) in Earth's atmosphere. Geological, isotopic, and chemical evidence suggests that this major environmental change happened around 2.45 billion years ago (2.45 Ga), during the Siderian period, at the beginning of the Proterozoic eon. The causes of the event remain unclear. (As of 2016), the geochemical and biomarker evidence for the development of oxygenic photosynthesis before the Great Oxidation Event has been mostly inconclusive. Oceanic cyanobacteria, which evolved into coordinated (but not multicellular or even colonial) macroscopic forms more than 2.3 billion years ago (approximately 200 million years before the GOE), are believed to have become the first microbes to produce oxygen by photosynthesis. Before the GOE, any free oxygen they produced was chemically captured by dissolved iron or by organic matter. The GOE started when oxygen produced by the cyanobacteria started escaping into the atmosphere, after other oxygen reservoirs were filled. The increased production of oxygen set Earth's original atmosphere off-balance. Free oxygen is toxic to obligate anaerobic organisms, and the rising concentrations may have destroyed most such organisms at the time. A spike in chromium contained in ancient rock-deposits formed underwater shows the accumulation had been washed off from the continental shelves. Chromium is not easily dissolved and its release from rocks would have required the presence of a powerful acid. One such acid, sulfuric acid (H2SO4), might have formed through bacterial reactions with pyrite. Mats of oxygen-producing cyanobacteria can produce a thin layer, one or two millimeters thick, of oxygenated water in an otherwise anoxic environment even under thick ice; before oxygen started accumulating in the atmosphere, these organisms would already have adapted to oxygen. Additionally, the free oxygen would have reacted with atmospheric methane, a greenhouse gas, greatly reducing its concentration and triggering the Huronian glaciation, possibly the longest episode of glaciation in Earth's history and called "snowball Earth". Eventually, the evolution of aerobic organisms that consumed oxygen established an equilibrium in its availability. Free oxygen has been an important constituent of the atmosphere ever since.
  • 3.0K
  • 10 Nov 2022
Topic Review
Air Temperature Forecasting
The accurate forecast of air temperature plays an important role in water resources management, land–atmosphere interaction, and agriculture. However, it is difficult to accurately predict air temperature due to its non-linear and chaotic nature. Several deep learning techniques have been proposed over the last few decades to forecast air temperature.
  • 3.0K
  • 11 Jan 2022
Topic Review
The NifA–NifL System for Nitrogen Fixation
Nitrogen–fixing bacteria execute biological nitrogen fixation through nitrogenase, converting inert dinitrogen (N2) in the atmosphere into bioavailable nitrogen. Elaborating the molecular mechanisms of orderly and efficient biological nitrogen fixation and applying them to agricultural production can alleviate the “nitrogen problem”. Azotobacter vinelandii is a well–established model bacterium for studying nitrogen fixation, utilizing nitrogenase encoded by the nif gene cluster to fix nitrogen. In Azotobacter vinelandii, the NifA–NifL system fine–tunes the nif gene cluster transcription by sensing the redox signals and energy status, then modulating nitrogen fixation. 
  • 3.0K
  • 06 Feb 2023
Topic Review
Natural Gas Conversion Technologies
Natural gas is a fossil fuel-based energy resource that is abundant in nature. It is a mixture of various components, predominantly methane. Natural gas has wide applications in the industries, residential buildings for heating, electricity generation, as a transportation fuel, and for various commercial purposes. The use of natural gas for electric power generation offers several advantages compared to other fossil fuels.
  • 3.0K
  • 13 Apr 2021
Topic Review
Nitrogen in Wetlands
Wetlands are viable sinks for nitrate and have also been identified as a source of nitrous oxide, a product of two microbially regulated processes: nitrification and denitrification. Anthropogenic expansion of nitrogen is a leading cause of the eutrophication of water bodies and may also contribute to the deterioration of the ozone layer in the stratosphere. Wetlands ameliorate the quality of water percolating through them, by retaining nutrients and sequestering carbon, and simultaneously enhancing the flora and fauna diversity of these landscapes. Among the many services these wetlands provide, they also alleviate nitrate pollution by attenuating reactive nitrogen from agricultural drainage and ensure the effective reclamation of the wastewater. 
  • 3.0K
  • 24 May 2021
Topic Review
The Shift Project
The Shift Project (also called The Shift or TSP) is a French nonprofit created in 2010 that aims to limit both climate change and the dependency of our economy on fossil fuels.
  • 3.0K
  • 02 Dec 2022
Topic Review
Sludge Treatment Reed Beds
Sludge Treatment Reed Beds (STRB) represent a state-of-the-art nature-based solution to sludge treatment and management. It is an effective, economical (i.e., of low investment, operation and maintenance cost, and low energy consumption), environmentally friendly, and technically efficient technology. In STRBs, the sludge is applied to a growing stand of reeds under controlled conditions. The method relies on the exploitation of the transpiring and aerating capabilities of the reeds, which absorb moisture and nutrients from the sludge for their growth. Additionally, the sludge is dewatered by drainage through the underlying gravel layers, and evaporation from the sludge surface. In the long run, the sludge is oxidized and its organic matter content decreases. The final solids content of the dewatered sludge can build up to and exceed 40%, depending on the sludge loading rate and the climate. STRB operational life is usually at least 30 years and is divided into two or three operational phases of 8-12 years. At the end of each operational phase, the accumulated residual sludge is removed and recycled typically in agriculture and the STRB is emptied.
  • 2.9K
  • 01 Apr 2021
Topic Review
Winkler Index
The Winkler Index, sometimes known as the Winkler Scale or Winkler Regions, is a technique for classifying the climate of wine growing regions based on heat summation or growing degree-days. In the system, geographical areas are divided into five climate regions based on temperature converted to growing degree-days, and is commonly known as Regions I–V (see below). The system was developed at the University of California, Davis by A. J. Winkler and Maynard Amerine.
  • 2.9K
  • 27 Sep 2022
Topic Review
Climate Change in Vietnam
Vietnam is considered, in coming decades, to be among the most affected countries by global climate change. A large number of studies that Vietnam is experiencing climate change and will be severely negatively affected in coming decades. These negative effects include sea level rise, salinity intrusion and other hydrological problems like flood, river mouth evolution, sedimentation as well as the increasing frequency of natural hazards such as cold waves, storm surges will all exert negative effects on the country's development and economy including agriculture, aquaculture, road infrastructure, etc. Some issues, such as land subsidence (caused by excessive groundwater extraction) further worsen some of the effects climate change will bring (sea level rise) especially in areas such as the Mekong Delta. The government, NGOs, and citizens have taken various measures to mitigate and adapt to the impact.
  • 2.9K
  • 14 Nov 2022
Topic Review
Impact of Tritium on Living Organisms
Tritium is a byproduct of many radiochemical reactions in the nuclear industry, and its effects on aquatic organisms, particularly low-dose effects, deserve special attention. The low-dose effects of tritium on aquatic microbiota have been intensively studied using luminous marine bacteria as model microorganisms. Low-dose physiological activation has been demonstrated and explained by the signaling role of reactive oxygen species through the “bystander effect” in bacterial suspensions. The activation of microbial functions in natural reservoirs by low tritium concentrations can cause unpredictable changes in food chains and imbalances in the natural equilibrium. The incorporation of tritium from the free form into organically bound compounds mainly occurs in the dark and at a temperature of 25 °C. When tritium is ingested by marine animals, up to 56% of tritium is accumulated in the muscle tissue and up to 36% in the liver. About 50% of tritium in the liver is bound in non-exchangeable forms. Human ingestion of water and food products contaminated with background levels of tritium does not significantly contribute to the total dose load on the human body. 
  • 2.9K
  • 22 Apr 2022
Topic Review
Vegetables Irrigated with Untreated Wastewater
Vegetables are commonly cultivated with untreated wastewater and consumed by human beings who often ignore their harmful impacts on health. The industrialization and urbanization in developing countries have led to the release of increasing amounts of heavy metals (HM) into the environment. Regular monitoring of metal concentration levels in contaminated soils and edible plants is essential to prevent their excessive build-up in the diet and food chains.
  • 2.9K
  • 25 Dec 2020
Topic Review
Exposure Routes and Health Risks Associated with Pesticides
There are four main pesticide application methods, including hydraulic spraying, backpack spraying, basal trunk spraying, and aerial spraying. Pesticide application methods are mainly selected by considering the habits of target pests, the characteristics of target sites, and the properties of pesticides. Humans are directly exposed to pesticides in occupational, agricultural, and household activities and are indirectly exposed to pesticides via environmental media, including air, water, soil, and food. Human exposure to pesticides occurs mainly through dermal, oral, and respiratory routes. People who are directly and/or indirectly exposed to pesticides may contract acute toxicity effects and chronic diseases. Although no segment of the general population is completely protected against exposure to pesticides and their potentially serious health effects, a disproportionate burden is shouldered by people in developing countries. Both deterministic and probabilistic human health risk assessments have their advantages and disadvantages and both types of methods should be comprehensively implemented in research on exposure and human health risk assessment. Equipment for appropriate pesticide application is important for application efficiency to minimize the loss of spray solution as well as reduce pesticide residuals in the environment and adverse human health effects due to over-spraying and residues. Policymakers should implement various useful measures, such as integrated pest management (IPM) laws that prohibit the use of pesticides with high risks and the development of a national implementation plan (NIP) to reduce the adverse effects of pesticides on the environment and on human health. 
  • 2.9K
  • 30 Jul 2022
Topic Review
Radioactivity in Plastic Materials
All fossil combustible materials, such as coal and crude oil, contain radioactive elements, which origin from the natural decay series of uranium and thorium. The basic material for the synthesis of plastics is crude oil. Therefore, plastics may contain radionuclides. The gamma ray analysis of different rubbish bags used in the city of Basel show a clear contamination with uranium, radium (226Ra and 228Ra) and lead (210Pb), resulting in a yearly charge of 300, 300, 150 and 3,000 MBq each. In comparison with the contamination level of the burning ashes, these charges are not relevant (less than 1% of the content in the slags from the waste incineration). Nonetheless, we note a permanent displacement of long-lived natural radionuclides to landfill-sites.
  • 2.9K
  • 05 Jul 2021
Topic Review
Driving Forces of Land Change
Indonesia has experienced one of the world’s greatest dynamic land changes due to forestry and agricultural practices. Understanding the drivers behind these land changes remains challenging, partly because landscape research is spread across many domains and disciplines. Our review shows that oil palm expansion is the most prominent among multiple direct causes of land change. We determined that property rights are the most prominent issue among the multiple underlying causes of land change. Distinct combinations of mainly economic, institutional, political, and social underlying drivers determine land change, rather than single key drivers. Our review also shows that central and district governments as decision-making actors are prominent among multiple land change actors. Our systematic review indicates knowledge gaps that can be filled by clarifying the identification and role of actors in land change.
  • 2.9K
  • 24 May 2021
Topic Review
Algae as Potential Bio-Pesticides
The term algae encompasses a wide range of photosynthetic organisms that are found primarily in freshwater and marine environments, although certain representatives can thrive in terrestrial niches, either on their own or by developing symbiotic relationships with other organisms.
  • 2.9K
  • 10 Feb 2022
Topic Review
Granular Organic Fertilizers
Granular organic fertilizers' production has recently become more popular, with the main aim of converting high-moisture organic matter, such as manure, manure mixtures, meat and bone waste or other organic matter, into pellets that are convenient to spread in the field. The pellets are usually produced with the diameter of 4 or 6 mm so that they can be easily spread with mineral or organic fertilizer spreaders. Once in the soil, organic fertilizer pellets become wet, decompose and release nutrients.
  • 2.9K
  • 11 Sep 2021
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