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Solar Disinfection
Solar water disinfection, in short SODIS, is a type of portable water purification that uses solar energy to make biologically-contaminated (e.g. bacteria, viruses, protozoa and worms) water safe to drink. Water contaminated with non-biological agents such as toxic chemicals or heavy metals require additional steps to make the water safe to drink. Solar water disinfection is usually accomplished using some mix of electricity generated by photovoltaics panels (solar PV), heat (solar thermal), and solar ultraviolet light collection. Solar disinfection using the effects of electricity generated by photovoltaics typically uses an electric current to deliver electrolytic processes which disinfect water, for example by generating oxidative free radicals which kill pathogens by damaging their chemical structure. A second approach uses stored solar electricity from a battery, and operates at night or at low light levels to power an ultraviolet lamp to perform secondary solar ultraviolet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flocculation
Flocculation, in the field of chemistry, is a process by which colloidal particles come out of suspension to sediment under the form of floc or flake, either spontaneously or due to the addition of a clarifying agent. The action differs from precipitation in that, prior to flocculation, colloids are merely suspended, under the form of a stable dispersion (where the internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation) and are not truly dissolved in solution. Coagulation and flocculation are important processes in water treatment with coagulation aimed to destabilize and aggregate particles through chemical interactions between the coagulant and colloids, and flocculation to sediment the destabilized particles by causing their aggregation into floc. Term definition According to the IUPAC definition, flocculation is "a process of contact and adhesion whereby the particles of a dispersion form larger-size clusters". Flocculation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Heidelberg
} Heidelberg University, officially the Ruprecht Karl University of Heidelberg, (german: Ruprecht-Karls-Universität Heidelberg; la, Universitas Ruperto Carola Heidelbergensis) is a public research university in Heidelberg, Baden-Württemberg, Germany. Founded in 1386 on instruction of Pope Urban VI, Heidelberg is Germany's oldest university and one of the world's oldest surviving universities; it was the third university established in the Holy Roman Empire. Heidelberg is one of the most prestigious and highly ranked universities in Europe and the world. Heidelberg has been a coeducational institution since 1899. The university consists of twelve faculties and offers degree programmes at undergraduate, graduate and postdoctoral levels in some 100 disciplines. The language of instruction is usually German, while a considerable number of graduate degrees are offered in English as well as some in French. As of 2021, 57 Nobel Prize winners have been affiliated with the city o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEHP
Bis(2-ethylhexyl) phthalate (di-2-ethylhexyl phthalate, diethylhexyl phthalate, diisooctyl phthalate, DEHP; incorrectly — dioctyl phthalate, DIOP) is an organic compound with the formula C6H4(CO2C8H17)2. DEHP is the most common member of the class of phthalates, which are used as plasticizers. It is the diester of phthalic acid and the branched-chain 2-ethylhexanol. This colorless viscous liquid is soluble in oil, but not in water. Production Di(2-ethylhexyl) phthalate is produced commercially by the reaction of excess 2-ethylhexanol with phthalic anhydride in the presence of an acid catalyst such as sulfuric acid or ''para''-toluenesulfonic acid. It was first produced in commercial quantities in Japan around 1933 and in the United States in 1939. : As 2-ethylhexanol is produced as a racemic mixture, DEHP consists of the (''R'',''R'')- and (''S'',''S'')-diasteromers, and the '' meso''-isomer. : Use Due to its suitable properties and the low cost, DEHP is widely used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalates
Phthalates (, ), or phthalate esters, are esters of phthalic acid. They are mainly used as plasticizers, i.e., substances added to plastics to increase their flexibility, transparency, durability, and longevity. They are used primarily to soften polyvinyl chloride (PVC). Note that while phthalates are usually plasticizers, not all plasticizers are phthalates. The two terms are specific and unique and cannot be used interchangeably. Lower-molecular-weight phthalates, those derived from C3-C6 alcohols, are being gradually replaced in many products in the United States, Canada, and European Union over health concerns. They are being replaced by high-molecular-weight phthalates (those with more than six carbons in their backbone, which gives them increased permanency and durability), as well as alternative plasticizers not based on phthalic anhydride. In 2010, the market was still dominated by high-phthalate plasticizers; however, due to legal provisions and growing environmental aw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipate
Adipates are the salts and esters of adipic acid. The anionic (HO2C(CH2)4CO2−) and dianionic (−O2C(CH2)4CO2−) forms of adipic acid are also referred to as adipate. Some adipate salts are used as acidity regulators, including: * Sodium adipate (E number E356) * Potassium adipate (E357) Some adipate esters are used as plasticizers, including: * Bis(2-ethylhexyl) adipate * Dioctyl adipate Dioctyl adipate (DOA) is an organic compound with the formula (CH2CH2CO2C8H17)2. It is a colorless oily liquid. As well as related diesters derived from 2-ethylhexanol, decanol, isodecanol, etc., it is used as a plasticizer. DEHA is sometimes ... * Dimethyl adipate {{HealthIssuesOfPlastics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss Federal Laboratories For Materials Testing And Research
The Swiss Federal Laboratories for Materials Science and Technology (Empa, German acronym for ''Eidgenössische Materialprüfungs- und Forschungsanstalt'') is an interdisciplinary Swiss research institute for applied materials sciences and technology. As part of the Swiss Federal Institutes of Technology Domain, it is an institution of the Swiss federation. For most of the period since its foundation in 1880, it concentrated on classical materials testing. Since the late 1980s it has developed into a modern research and development institute. Research According to its vision – Materials and technologies for a sustainable future – Empa aims at developing solutions for current problems facing industry and society in areas such as energy, the environment, mobility, health and safety. Research is concentrated in five Research Focus Areas: "Nanostructured Materials," "Sustainable Built Environment," "Health and Performance," "Natural Resources and Pollutants," and "Energy". Em ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resin Identification Code
The ASTM International Resin Identification Coding System, often abbreviated RIC, is a set of symbols appearing on plastic products that identify the plastic resin out of which the product is made. It was developed in 1988 by the Society of the Plastics Industry (now the Plastics Industry Association) in the United States, but since 2008 it has been administered by ASTM International, an international standards organization. History The US Society of the Plastics Industry (SPI) first introduced the system in 1988 as the "Voluntary Plastic Container Coding System". The SPI stated that one purpose of the original SPI code was to "Provide a consistent national system to facilitate recycling of post-consumer plastics." The system has been adopted by a growing number of communities implementing recycling programs, as a tool to assist in sorting plastics. In order to deal with the concerns of recyclers across the U.S., the RIC system was designed to make it easier for workers in mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many applications. Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA). Structure Carbonate esters have planar OC(OC)2 cores, which confers rigidity. The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted). Polycarbonates received their name because they are polymers containing carbonate groups (−O−(C=O)−O−). A balance of useful features, including temperature resistance, impact resistance and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene Terephthalate
Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, and thermoforming for manufacturing, and in combination with glass fibre for engineering resins. In 2016, annual production of PET was 56 million tons. The biggest application is in fibres (in excess of 60%), with bottle production accounting for about 30% of global demand. In the context of textile applications, PET is referred to by its common name, polyester, whereas the acronym ''PET'' is generally used in relation to packaging. Polyester makes up about 18% of world polymer production and is the fourth-most-produced polymer after polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC). PET consists of repeating (C10H8O4) units. PET is commonly recycled, and has the digit 1 (♳) as its resin identification code (RIC). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U+2673 DejaVu Sans
U or u, is the twenty-first and sixth-to-last Letter (alphabet), letter and fifth vowel letter of the Latin alphabet, used in the English alphabet, modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is English alphabet#Letter names, ''u'' (pronounced ), plural English alphabet#Letter names, ''ues''. History U derives from the Semitic Waw (letter), waw, as does F, and later, Y, W, and V. Its oldest ancestor goes to Egyptian hieroglyphs, Egyptian hieroglyphics, and is probably from a hieroglyph of a mace or fowl, representing the sound [Voiced labiodental fricative, v] or the sound [Voiced labial–velar approximant, w]. This was borrowed to Phoenician, where it represented the sound [w], and seldom the vowel [Close back rounded vowel, u]. In Greek language, Greek, two letters were adapted from the Phoenician waw. The letter was adapted, but split in two, with the Digamma, first one of the same name (Ϝ) being ada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbid
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caused by growth of phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
