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Topic Review
Environmental Impact of Shipping
The environmental impact of shipping includes air pollution, water pollution, acoustic, and oil pollution. Ships are responsible for more than 18 percent of some air pollutants. It also includes greenhouse gas emissions. The International Maritime Organization (IMO) estimates that carbon dioxide emissions from shipping were equal to 2.2% of the global human-made emissions in 2012 and expects them to rise 50 to 250 percent by 2050 if no action is taken. There is a perception that cargo transport by ship is low in air pollutants, because for equal weight and distance it is the most efficient transport method, according to shipping researcher Alice Bows-Larkin. This is particularly true in comparison to air freight. However, because sea shipment accounts for far more annual tonnage and the distances are often large, shipping's emissions are globally substantial. A difficulty is that the annual increasing amount of shipping overwhelms gains in efficiency, such as from slow-steaming or the use of kites. The growth in tonne-kilometers of sea shipment has averaged 4 percent yearly since the 1990s, and it has grown by a factor of 5 since the 1970s. There are now over 100,000 transport ships at sea, of which about 6,000 are large container ships. The fact that shipping enjoys substantial tax privileges has contributed to the growing emissions.
  • 25.9K
  • 31 Oct 2022
Topic Review
Water Mills
The reuse of built agricultural/industrial heritage has been a common practice worldwide. These structures represent excellent symbols of the great agricultural/industrial past. These agricultural/hydro-technologies also serve as monuments of socio-cultural identities, especially in rural areas and on small farms. One example of a successful application of agricultural technologies for small farms is the water mill. By harnessing the water energy, they were used for traditional flour and other goods production (e.g., olive oil) and works requiring energy, with the main role in the evolution of the traditional/cultural landscape. Water mills have been used to drive a mechanical process of milling, hammering, and rolling and are a portion of the agricultural, cultural, and industrial heritage.
  • 21.4K
  • 17 Mar 2023
Topic Review
Water Quality Degradation
Water quality degradation is happened through the natural processes that influence the surface water and groundwater quality by various sources such as climate changes, natural disasters, geological factors, soil-matrix, and hyporheic exchange. Water could also be contaminated by anthropogenic factors. Anthropogenic pollutants are substances caused by human actions, mostly resulting from land-use practices. 
  • 12.6K
  • 05 Feb 2022
Topic Review
Water Quality Index
A critical water quality index (WQI) method has been used to determine the overall water quality status of surface water and groundwater systems globally since the 1960s. WQI follows four steps: parameter selection, sub-indices, establishing weights, and final index aggregation.
  • 10.9K
  • 09 Apr 2021
Topic Review
Plasma technology water purification
Plasma technology water purification is a new water treatment technology developed according to the trend of industrial water use in the 21st century. It is effective, efficient, scalable, versatile and customizable. These technologies must be able to adapt to new contaminants, reduce energy consumption, maintain or improve the proportionality between power and flow, demonstrate various flow capacities, minimize the transformation of existing infrastructure, prepare for imminent regulations, and tailor chemistry to site-specific requirements. New methods of water treatment by plasma must have all the above-mentioned properties and pose the least risk to public health. NTAPPs and their chemical reactions release energy and reactive chemical species that can kill bacteria and microorganisms, resulting in the disinfection of water. The advantage of this technique is that it can be performed in ambient air under atmospheric pressure without a vacuum system. Furthermore, NTAPP does not involve chemical products such as Cl. NTAPP can be used for water treatment in three ways: via direct, indirect, and bubbling methods.
  • 9.4K
  • 10 Jun 2021
Topic Review
List of Island Countries
This is a list of island countries. An island is a landmass (smaller than a continent) that is surrounded by water. Many island countries are spread over an archipelago, as is the case with the Federated States of Micronesia and Indonesia (both of which consist of thousands of islands). Others consist of a single island, such as Barbados or Nauru, or part of an island, such as the Dominican Republic or Brunei. Australia is a continent, although it has historically been referred to as an island, due to it having no land borders. The list also includes states with limited diplomatic recognition which have de facto control over territories entirely on the islands, such as Taiwan.[n 1] Indonesia is the world's largest island country by area (1,904,569 km2), and by total number of islands (more than 18,307), and is also the world's most populous island country, with a population of over 270 million (the fourth-largest population in the world, after China , India , and the United States ).
  • 8.8K
  • 14 Oct 2022
Topic Review
Carbonaceous Biochemical Oxygen Demand
Carbonaceous biochemical oxygen demand or CBOD is a method defined test measured by the depletion of dissolved oxygen by biological organisms in a body of water in which the contribution from nitrogenous bacteria has been suppressed. CBOD is a method defined parameter is widely used as an indication of the pollutant removal from wastewater. It is listed as a conventional pollutant in the U.S. Clean Water Act.
  • 7.8K
  • 21 Nov 2022
Topic Review
Permeability (Earth Sciences)
Permeability in fluid mechanics and the earth sciences (commonly symbolized as κ, or k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it. The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.
  • 5.6K
  • 25 Oct 2022
Topic Review
Club of Rome
Founded in 1968 at Accademia dei Lincei in Rome, Italy, the Club of Rome consists of current and former heads of state, UN bureaucrats, high-level politicians and government officials, diplomats, scientists, economists, and business leaders from around the globe. It stimulated considerable public attention in 1972 with the first report to the Club of Rome, The Limits to Growth. Since 1 July 2008 the organization has been based in Winterthur, Switzerland.
  • 5.4K
  • 02 Nov 2022
Topic Review
Satellite-Based Groundwater Monitoring
Satellite is an effective technology to assess water storages remotely through remote sensing and geographic information system (RS and GIS), which are very useful tools in groundwater exploration mapping. They provide inputs to assess the total groundwater resources in a region and for the selection of suitable sites for drilling or artificial recharge.
  • 4.6K
  • 18 Feb 2022
Topic Review
Water-Related Issues in Bhutan
Water for hydropower in Bhutan has been in focus as compared to that allocated for irrigation, industries, and environmental demand. The demand for water in Bhutan has also increased in the last decade due to population increase, changes in lifestyle, and economic advancements through tourism and hydropower projects.
  • 4.1K
  • 28 Apr 2021
Topic Review
Mangalore
Mangalore (/mæŋɡəˈlɔːr/), officially known as Mangaluru, is a major port city of the Indian state of Karnataka. It is located between the Arabian Sea and the Western Ghats about 352 km (219 mi) west of Bangalore, the state capital, 20 km north of Karnataka–Kerala border, 297 km south of Goa. Mangalore is the state's only city to have all four modes of transport—air, road, rail and sea. The population of the urban agglomeration was 619,664 (As of 2011) national census of India. It is known for being one of the locations of the Indian strategic petroleum reserves. The city developed as a port in the Arabian Sea during ancient times; it has since developed into a major port of India that handles 75 per cent of India's coffee and cashew exports, and is the country's seventh largest container port. Mangalore has been ruled by several major powers, including the Kadambas, Alupas, Vijayanagar Empire, Keladi Nayaks and the Portuguese. The city was a source of contention between the British and the Kingdom of Mysore rulers Hyder Ali and Tipu Sultan, and was eventually annexed by the British in 1799. Mangalore remained part of the Madras Presidency until India's independence in 1947 and was unified with Mysore State (now called Karnataka) in 1956. Mangalore is also the administrative headquarters of the Dakshina Kannada district, and is a commercial, industrial, educational, healthcare and startup hub. This city's International Airport is the second-largest and second-busiest airport in Karnataka. Mangalore City Corporation is responsible for the civic administration, which manages the 60 wards of the city. The city's landscape is characterised by rolling hills, coconut palms, rivers and hard laterite soil. India's first 3D planetarium with 8K resolution display is situated in this city. Mangalore is also included in the Smart Cities Mission list and is among the 100 smart cities to be developed in India. The city has an average elevation of 22 m (72 ft) above mean sea level. Mangalore has a tropical monsoon climate and is under the influence of the southwest monsoon. (As of 2017), Mangalore was ranked the 48th best city to live in the world by a US survey, and the only Indian city in the top 50.
  • 4.0K
  • 17 Oct 2022
Topic Review
Water Quality Monitoring
Monitoring water quality is an essential tool for the control of pollutants and pathogens that can cause damage to the environment and human health. However, water quality analysis is usually performed in laboratory environments, often with the use of high-cost equipment and qualified professionals. With the progress of nanotechnology and the advance in engineering materials, several studies have shown, in recent years, the development of technologies aimed at monitoring water quality, with the ability to reduce the costs of analysis and accelerate the achievement of results for management and decision-making.
  • 3.6K
  • 13 May 2022
Topic Review
Pelagic Zone
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word pelagic is derived from grc πέλαγος (pélagos) 'open sea'. The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirring up waves and setting currents in motion. The pelagic zone refers to the open, free waters away from the shore, where marine life can swim freely in any direction unhindered by topographical constraints. The oceanic zone is the deep open ocean beyond the continental shelf, which contrasts with the inshore waters near the coast, such as in estuaries or on the continental shelf. Waters in the oceanic zone plunge to the depths of the abyssopelagic and further to the hadopelagic. Coastal waters are generally the relatively shallow epipelagic. Altogether, the pelagic zone occupies 1,330 million km3 (320 million mi3) with a mean depth of 3.68 km (2.29 mi) and maximum depth of 11 km (6.8 mi). Pelagic life decreases as depth increases. The pelagic zone contrasts with the benthic and demersal zones at the bottom of the sea. The benthic zone is the ecological region at the very bottom, including the sediment surface and some subsurface layers. Marine organisms such as clams and crabs living in this zone are called benthos. Just above the benthic zone is the demersal zone. Demersal fish can be divided into benthic fish, which are denser than water and rest on the bottom, and benthopelagic fish, which swim just above the bottom. Demersal fish are also known as bottom feeders and groundfish.
  • 3.3K
  • 14 Nov 2022
Topic Review
Kuroshio Current
The Kuroshio (黒潮), also known as the Black or Japan Current (日本海流, Nihon Kairyū) or the Black Stream, is a north-flowing, warm ocean current on the west side of the North Pacific Ocean. Like the Gulf Stream in the North Atlantic, the Kuroshio is a powerful western boundary current and forms the western limb of the North Pacific Subtropical Gyre.
  • 3.2K
  • 09 Oct 2022
Topic Review
Production and Use of Typical Rubber Antioxidants
Antioxidants are prevalently used during rubber production to improve rubber performance, delay aging, and extend service life. Studies have revealed that their transformation products (TPs) could adversely affect environmental organisms and even lead to environmental events, which led to great public concern about environmental occurrence and potential impacts of rubber antioxidants and their TPs.
  • 3.2K
  • 22 Dec 2022
Topic Review
Deep Sea Fish
Deep-sea fish are animals that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the sea. The lanternfish is, by far, the most common deep-sea fish. Other deep sea fishes include the flashlight fish, cookiecutter shark, bristlemouths, anglerfish, viperfish, and some species of eelpout. Only about 2% of known marine species inhabit the pelagic environment. This means that they live in the water column as opposed to the benthic organisms that live in or on the sea floor. Deep-sea organisms generally inhabit bathypelagic (1000–4000m deep) and abyssopelagic (4000–6000m deep) zones. However, characteristics of deep-sea organisms, such as bioluminescence can be seen in the mesopelagic (200–1000m deep) zone as well. The mesopelagic zone is the disphotic zone, meaning light there is minimal but still measurable. The oxygen minimum layer exists somewhere between a depth of 700m and 1000m deep depending on the place in the ocean. This area is also where nutrients are most abundant. The bathypelagic and abyssopelagic zones are aphotic, meaning that no light penetrates this area of the ocean. These zones make up about 75% of the inhabitable ocean space. The epipelagic zone (0–200m) is the area where light penetrates the water and photosynthesis occurs. This is also known as the photic zone. Because this typically extends only a few hundred meters below the water, the deep sea, about 90% of the ocean volume, is in darkness. The deep sea is also an extremely hostile environment, with temperatures that rarely exceed 3 °C (37.4 °F) and fall as low as −1.8 °C (28.76 °F) (with the exception of hydrothermal vent ecosystems that can exceed 350 °C, or 662 °F), low oxygen levels, and pressures between 20 and 1,000 atmospheres (between 2 and 100 megapascals).
  • 3.0K
  • 08 Nov 2022
Topic Review
Water Well
A water well is an excavation or structure created in the ground by digging, driving, boring, or drilling to access groundwater in underground aquifers. The well water is drawn by a pump, or using containers, such as buckets, that are raised mechanically or by hand. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age. Wells have traditionally been sunk by hand digging, as is the case in rural areas of the developing world. These wells are inexpensive and low-tech as they use mostly manual labour, and the structure can be lined with brick or stone as the excavation proceeds. A more modern method called caissoning uses pre-cast reinforced concrete well rings that are lowered into the hole. Driven wells can be created in unconsolidated material with a well hole structure, which consists of a hardened drive point and a screen of perforated pipe, after which a pump is installed to collect the water. Deeper wells can be excavated by hand drilling methods or machine drilling, using a bit in a borehole. Drilled wells are usually cased with a factory-made pipe composed of steel or plastic. Drilled wells can access water at much greater depths than dug wells. Two broad classes of well are shallow or unconfined wells completed within the uppermost saturated aquifer at that location, and deep or confined wells, sunk through an impermeable stratum into an aquifer beneath. A collector well can be constructed adjacent to a freshwater lake or stream with water percolating through the intervening material. The site of a well can be selected by a hydrogeologist, or groundwater surveyor. Water may be pumped or hand drawn. Impurities from the surface can easily reach shallow sources and contamination of the supply by pathogens or chemical contaminants needs to be avoided. Well water typically contains more minerals in solution than surface water and may require treatment before being potable. Soil salination can occur as the water table falls and the surrounding soil begins to dry out. Another environmental problem is the potential for methane to seep into the water.
  • 2.8K
  • 27 Oct 2022
Topic Review
Power Generation in Sewage-Water Treatment Plants
Sewage-water treatment comprehends primary, secondary, and tertiary steps to produce reusable water after removing sewage contaminants. However, a sewage-water treatment plant is typically a power and energy consumer and produces high volumes of sewage sludge mainly generated in the primary and secondary steps. The use of more efficient anaerobic digestion of sewage water with sewage sludge can produce reasonable flowrates of biogas, which is shown to be a consolidated strategy towards the energy self-sufficiency and economic feasibility of sewage-water treatment plants. Anaerobic digestion can also reduce the carbon footprint of energy sources since the biogas produced can replace fossil fuels for electricity generation. 
  • 2.7K
  • 05 May 2022
Topic Review
Photocatalytic Reactors Design
The photoreactors design and concepts vary based on the working regime (static or dynamic), photocatalyst morphology (powders or bulk) and volume.
  • 2.7K
  • 10 May 2021
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