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Reuse of Excreta
Reuse of excreta refers to the safe, beneficial use of animal or human excreta, i.e. feces and urine. Such beneficial use involves mainly the nutrient, organic matter and energy contained in human excreta, rather than the water content (as is the case for wastewater reuse). Reuse of human excreta can involve using it as a soil conditioner or fertilizer in agriculture, gardening, aquaculture, or horticultural activities. Excreta can also be used as a fuel source or as a building material. Human excreta contains resources that can be recovered: plant-available nutrients nitrogen, phosphorus, potassium as well as micronutrients such as sulphur and organic matter. These resources which are contained in human excreta or in domestic wastewater (sewage) have traditionally been used in agriculture in many countries. They are still being used in agriculture to this day, but the practice is often carried out in an unregulated and unsafe manner in developing countries. The WHO Guidelines from 2006 have set up a framework how this reuse can be done safely by following a "multiple barrier approach". There are several "excreta-derived fertilizers" which vary in their properties and fertilizing characteristics: urine, dried feces, composted feces, faecal sludge (septage), sewage, sewage sludge, and animal manure. However, reuse of animal and human excreta can cause health risk and environmental problems because of pathogen, pharmaceutical residues and nitrate pollution. Reuse of human excreta is the final step of the sanitation chain which starts with collection of human excreta (by use of toilets) and continues with transport and treatment all the way to either disposal or reuse.
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  • 18 Oct 2022
Topic Review
Gadget (Computer Science)
In computational complexity theory, a gadget is a subset of a problem instance that simulates the behavior of one of the fundamental units of a different computational problem. Gadgets are typically used to construct reductions from one computational problem to another, as part of proofs of NP-completeness or other types of computational hardness. The component design technique is a method for constructing reductions by using gadgets. (Szabó 2009) traces the use of gadgets to a 1954 paper in graph theory by W. T. Tutte, in which Tutte provided gadgets for reducing the problem of finding a subgraph with given degree constraints to a perfect matching problem. However, the "gadget" terminology has a later origin, and does not appear in Tutte's paper.
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  • 18 Oct 2022
Topic Review
Metastable Inner-Shell Molecular State
Metastable Innershell Molecular State (MIMS) is a class of ultra-high-energy short-lived molecules have the binding energy up to 1,000 times larger and bond length up to 100 times smaller than typical molecules. MIMS is formed by inner-shell electrons that are normally resistant to molecular formation. However, in stellar conditions, the inner-shell electrons become reactive to form molecular structures (MIMS) from combinations of all elements in the periodic table. MIMS upon dissociation can emit x-ray photons with energies up to 100 keV at extremely high conversion efficiencies from compression energy to photon energy. MIMS is predicted to exist and dominate radiation processes in extreme astrophysical environments, such as large planet cores, star interiors, and black hole and neutron star surroundings. There, MIMS is predicted to enable highly energy-efficient transformation of the stellar compression energy into the radiation energy. The right schematic illustration shows the proposed four stages of the K-shell MIMS (K-MIMS) formation and x-ray generation process. Stage I: Individual atoms are subjected to the stellar compression and ready for absorbing the compression energy. Stage II: The outer electron shells fuse together under increasing "stellar" pressure. Stage III: At the peak pressure, via pressure ionization K-shell orbits form the K-MIMS, which is vibrationally hot and encapsulated by a Rydberg-like pseudo-L-Shell structure. Stage IV: The K-MIMS cools down by ionizing ("boiling-off") a number of pseudo-L-shell electrons and subsequent optical decay by emitting an x-ray photon. The dissociated atoms return their original atoms states and are ready for absorbing the compression energy. MIMS also can be readily produced in laboratory and industrial environments, such as hypervelocity particle impact, laser fusion and z-machine. MIMS can be exploited for highly energy-efficient production of high intensity x-ray beams for a wide range of innovative applications, such as photolithography, x-ray lasers, and inertial fusion.
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  • 18 Oct 2022
Topic Review
List of Oxidation States of the Elements
This is a list of known oxidation states of the chemical elements, excluding nonintegral values. The most common states appear in bold. The table is based on that of Greenwood and Earnshaw, with additions noted. Oxidation state 0, which occurs for all elements, is implied by the column with the symbol of the element. The format of the table, which was devised by Dmitri Mendeleev in 1889, shows the periodicity of the oxidation states of the elements.
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  • 18 Oct 2022
Topic Review
Osmium-195
Osmium (76Os) has seven naturally occurring isotopes, five of which are stable: 187Os, 188Os, 189Os, 190Os, and (most abundant) 192Os. The other natural isotopes, 184Os, and 186Os, have extremely long half-life (1.12×1013 years and 2×1015 years, respectively) and for practical purposes can be considered to be stable as well. 187Os is the daughter of 187Re (half-life 4.56×1010 years) and is most often measured in an 187Os/188Os ratio. This ratio, as well as the 187Re/188Os ratio, have been used extensively in dating terrestrial as well as meteoric rocks. It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the mantle roots of continental cratons. However, the most notable application of Os in dating has been in conjunction with iridium, to analyze the layer of shocked quartz along the Cretaceous–Paleogene boundary that marks the extinction of the dinosaurs 66 million years ago. There are also 30 artificial radioisotopes, the longest-lived of which is 194Os with a half-life of six years; all others have half-lives under 94 days. There are also nine known nuclear isomers, the longest-lived of which is 191mOs with a half-life of 13.10 hours. All isotopes and nuclear isomers of osmium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
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  • 18 Oct 2022
Topic Review
List of Gliders (L)
This is a list of gliders/sailplanes of the world, (this reference lists all gliders with references, where available) Note: Any aircraft can glide for a short time, but gliders are designed to glide for longer.
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  • 18 Oct 2022
Topic Review
Black Tiger (Animal)
A black tiger is a rare colour variant of the tiger and is not a distinct species or geographic subspecies.
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  • 18 Oct 2022
Topic Review
Cardiff
Cardiff (/ˈkɑːrdɪf/ (listen); Welsh: Caerdydd [kairˈdiːð, kɑːɨrˈdɨːð] (listen)) is the capital of Wales, and its largest city. The eleventh-largest city in the United Kingdom , it is Wales's chief commercial centre, the base for most national cultural institutions and Welsh media, and the seat of the National Assembly for Wales. The unitary authority area's 2017 population was estimated to be 362,756. Cardiff is a significant tourist centre and the most popular visitor destination in Wales with 21.3 million visitors in 2017. In 2011, Cardiff was ranked sixth in the world in National Geographic's alternative tourist destinations. Cardiff is the county town of the historic county of Glamorgan (and later South Glamorgan). Cardiff is part of the Eurocities network of the largest European cities. A small town until the early 19th century, its prominence as a major port for the transport of coal following the arrival of industry in the region contributed to its rise as a major city. The Cardiff Built-up Area covers a slightly larger area outside the county boundary and includes the towns of Dinas Powys and Penarth. In 1905, Cardiff was made a city and proclaimed the capital of Wales in 1955. Since the 1980s, Cardiff has seen significant development. A new waterfront area at Cardiff Bay contains the Senedd building, home to the Welsh Assembly and the Wales Millennium Centre arts complex. Current developments include the continuation of the redevelopment of the Cardiff Bay and city centre areas with projects such as the Cardiff International Sports Village, a BBC drama village, and a new business district in the city centre. Sporting venues in the city include the Principality Stadium—the national stadium and the home of the Wales national rugby union team—Sophia Gardens (the home of Glamorgan County Cricket Club), Cardiff City Stadium (the home of Cardiff City football team and the Wales football team), Cardiff International Sports Stadium (the home of Cardiff Amateur Athletic Club), Cardiff Arms Park (the home of Cardiff Blues and Cardiff RFC rugby union teams) and Ice Arena Wales (the home of Cardiff Devils ice hockey team). The city hosted the 1958 British Empire and Commonwealth Games. The city was awarded the title of European City of Sport twice, due to its role in hosting major international sporting events: first in 2009 and again in 2014. The Principality Stadium hosted 11 football matches as part of the 2012 Summer Olympics, including the games' opening event and the men's bronze medal match.
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  • 18 Oct 2022
Topic Review
Blairism
In British politics, Blairism is the political ideology of the former leader of the Labour Party and Prime Minister Tony Blair and those that follow him. It entered the New Penguin English Dictionary in 2000. Proponents of Blairism are referred to as Blairites.
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  • 18 Oct 2022
Topic Review
Mental Breakdown
A mental breakdown (also known as a nervous breakdown) is an acute mental disorder. Symptoms include severe, stress-induced depression, anxiety, paranoia, and dissociation in a previously functioning individual. A nervous breakdown is often tied to psychological burnout, severe overwork, sleep deprivation, and similar problems. While temporary, a mental breakdown can last for years and a person cannot resume normal activites until the disorder is resolved.
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  • 18 Oct 2022
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