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Urea Resins
Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, is a nontransparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesives, plywood, particle board, medium-density fibreboard (MDF), and molded objects. In agriculture, urea-formaldehyde compounds are one of the most commonly used types of slow-release fertilizer. UF and related amino resins are a class of thermosetting resins of which urea-formaldehyde resins make up 80% produced worldwide. Examples of amino resins use include in automobile tires to improve the bonding of rubber, in paper for improving tear strength, and in molding electrical devices, jar caps, etc. History UF was first synthesized in 1884 by Dr Hölzer, who was working with Bernhard Tollens, neither of whom realized that the urea and formaldehyde were polymerizing. In the following years a large number of authors worked on the structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transparency (optics)
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale (one in which the dimensions are much larger than the wavelengths of the photons in question), the photons can be said to follow Snell's law. Translucency (also called translucence or translucidity) is the physical property of allowing light to pass through the material (with or without scattering of light). It allows light to pass through but the light does not necessarily follow Snell's law on the macroscopic scale; the photons may be scattered at either of the two interfaces, or internally, where there is a change in the index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bis(hydroxymethyl)urea
Bis(hydroxymethyl)urea is an organic compound with the formula OC(NHCH2OH)2. This white water-soluble solid is an intermediate in the formation of urea-formaldehyde resins. It forms upon treatment of urea with an excess of formaldehyde Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ....{{ Ullmann , author = C. Nitschke , author2 = G. Scherr , title = Urea Derivatives , year = 2012, doi = 10.1002/14356007.o27_o04 References Ureas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connecticut
Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. Its capital is Hartford, Connecticut, Hartford, and its most populous city is Bridgeport, Connecticut, Bridgeport. Connecticut lies between the major hubs of New York City and Boston along the Northeast megalopolis, Northeast Corridor, where the New York metropolitan area, New York-Newark Combined Statistical Area, which includes four of Connecticut's seven largest cities, extends into the southwestern part of the state. Connecticut is the List of U.S. states and territories by area, third-smallest state by area after Rhode Island and Delaware, and the List of U.S. states and territories by population, 29th most populous with more than 3.6 million residents as of 2024, ranking it fourth among the List of states and territories of the Unite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massachusetts
Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode Island to its south, New Hampshire and Vermont to its north, and New York (state), New York to its west. Massachusetts is the List of U.S. states and territories by area, sixth-smallest state by land area. With a 2024 U.S. Census Bureau-estimated population of 7,136,171, its highest estimated count ever, Massachusetts is the most populous state in New England, the List of U.S. states and territories by population, 16th-most-populous in the United States, and the List of states and territories of the United States by population density, third-most densely populated U.S. state, after New Jersey and Rhode Island. Massachusetts was a site of early British colonization of the Americas, English colonization. The Plymouth Colony was founded in 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USDA
The United States Department of Agriculture (USDA) is an United States federal executive departments, executive department of the Federal government of the United States, United States federal government that aims to meet the needs of commercial farming and livestock food production, promotes agricultural trade and production, works to assure food safety, protects natural resources, fosters rural communities and works to end hunger in the United States and internationally. It is headed by the secretary of agriculture, who reports directly to the president of the United States and is a member of the president's Cabinet of the United States, Cabinet. The current secretary is Brooke Rollins, who has served since February 13, 2025. Approximately 71% of the USDA's $213 billion budget goes towards nutrition assistance programs administered by the Food and Nutrition Service (FNS). The largest component of the FNS budget is the Supplemental Nutrition Assistance Program (formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Mantanis
George Mantanis ('; born September 18, 1966) is a Greek wood scientist and professor at the University of Thessaly, Greece, who is an elected fellow (''FIAWS'') of the International Academy of Wood Science and co-editor of the journal, Wood Material Science and Engineering. Early life and education Mantanis was born in Mytilene, Lesvos, Greece in 1966, and grew up in the village Stipsi. He is the eldest son of Eleni Sevastou and her husband, Ignatios Mantanis. He completed his secondary education with honors at the High School of Kalloni at Lesbos island, in 1984. Subsequently, from 1984 to 1989, he pursued undergraduate studies in forestry specializing in wood technology, earning a university diploma from the Aristotle University of Thessaloniki, Department of Forestry and Natural Environment. After receiving a McIntire–Stennis scholarship, he pursued doctoral studies in the United States of America under the supervision of Raymond A. Young at the University of Wiscons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropospheric Ozone
Ground-level ozone (), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface. The troposphere extends from the ground up to a variable height of approximately 14 kilometers above sea level. Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. Ground-level or tropospheric ozone is created by chemical reactions between NOx gases (oxides of nitrogen produced by combustion) and volatile organic compounds (VOCs). The combination of these chemicals in the presence of sunlight form ozone. Its concentration increases as height above sea level increases, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R-value (insulation)
The ''R''-value is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window or a complete wall or ceiling, resists the conductive flow of heat, in the context of construction. R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the warmer surface and colder surface of a barrier under steady-state conditions. The measure is therefore equally relevant for lowering energy bills for heating in the winter, for cooling in the summer, and for general comfort. The ''R-value'' is the building industry term for thermal resistance "per unit area." It is sometimes denoted RSI-value if the SI units are used. An R-value can be given for a material (e.g., for polyethylene foam), or for an assembly of materials (e.g., a wall or a window). In the case of materials, it is often expressed in terms of R-value per metre. R-values are additive for layers of materials, and the higher the R-value the better th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spray Foams (insulation)
Spray foam (expanding foam in the UK) is a chemical product used in construction and engineering primarily as insulation and as a filler material. It is produced as a liquid but quickly expands and hardens into a stiff, lightweight structure. It is created by a chemical reaction of two component parts, commonly referred to as side A and side B. Side A contains very reactive chemicals known as isocyanate. Side B contains a polyol, which reacts with isocyanates to make polyurethane, and a mixture of other chemicals, including catalysts (which help the reaction to occur), flame retardant, blowing agents and surfactants. These react when mixed with each other and expand up to 30-60 times its liquid volume after it is sprayed in place. This expansion makes it useful as a specialty packing material which forms to the shape of the product being packaged and produces a high thermal insulating value with virtually no air infiltration. History Otto Bayer (1902–1982) is credited with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea-formaldehyde Insulation
Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, is a nontransparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesives, plywood, particle board, medium-density fibreboard (MDF), and molded objects. In agriculture, urea-formaldehyde compounds are one of the most commonly used types of slow-release fertilizer. UF and related amino resins are a class of thermosetting resins of which urea-formaldehyde resins make up 80% produced worldwide. Examples of amino resins use include in automobile tires to improve the bonding of rubber, in paper for improving tear strength, and in molding electrical devices, jar caps, etc. History UF was first synthesized in 1884 by Dr Hölzer, who was working with Bernhard Tollens, neither of whom realized that the urea and formaldehyde were polymerizing. In the following years a large number of authors worked on the structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corduroy
Corduroy is a textile with a distinctively raised "cord" or wale texture. Modern corduroy is most commonly composed of tufted cords, sometimes exhibiting a channel (bare to the base fabric) between them. Both velvet and corduroy derive from fustian fabric. Corduroy looks as if it is made from multiple cords laid parallel to each other. Etymology A common false etymology holds that the word "corduroy" derives from the French phrase ''corde du roi'' or ''the cord of the king''. The word ''corduroy'' is from ''cord'' (i.e., rope) and '' duroy,'' which was a coarse woollen cloth made in England in the 18th century. Variations Corduroy is made by weaving extra sets of fibre into the base fabric to form vertical ridges called ''wales''. The wales are built so that clear lines can be seen when they are cut into pile. Corduroy is considered a durable cloth and is found in the construction of trousers, jackets, and shirts. The width of the wales varies between fabric styles and is spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
