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Chromated Copper Arsenate
Chromated copper arsenate (CCA) is a wood preservative containing compounds of chromium, copper, and arsenic, in various proportions. It is used to impregnate timber and other wood products, especially those intended for outdoor use, in order to protect them from attack by microbes and insects. Like other copper-based wood preservatives, it imparts a greenish tint to treated timber. CCA was invented in 1933 by Indian chemist Sonti Kamesam, and patented in Britain in 1934. It has been used for timber treatment since the mid-1930s, and is marketed under many trade names. In 2003, the United States Environmental Protection Agency and the lumber industry agreed to discontinue the use of CCA-treated wood in most residential construction. This agreement was intended to protect the health of humans and the environment by reducing exposure to the arsenic in CCA-treated wood. As a result of this decision, CCA-treated wood can no longer be used to construct residential structures such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Preservative
Wood preservation refers to any method or process, or even technique, used to protect the wood and extend its service life. Most wood species are susceptible to both biological (''biotic'') and non-biological (''abiotic'') factors that cause decay and/or deterioration. Only a limited number of wood species possess natural durability, and even those may not be suitable for all environments. In general, wood benefits from appropriate preservation measures. In addition to structural design considerations, a variety of chemical preservatives and treatment processes — commonly known as timber treatment, lumber treatment, pressure treatment or modification treatment — are used to enhance the durability of wood and wood-based products, including engineered wood. These treatments may involve physical, chemical, thermal, and/or biological methodology aimed at protecting wood from degradation. They increase its resistance to biological agents such as fungi, termites, and insects, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(II) Arsenate
Copper arsenate (Cu3(AsO4)2·4H2O, or Cu5H2(AsO4)4·2H2O), also called copper orthoarsenate, tricopper arsenate, cupric arsenate, or tricopper orthoarsenate, is a blue or bluish-green powder insoluble in water and alcohol and soluble in aqueous ammonium and dilute acids. Uses Copper arsenate is an insecticide used in agriculture. It is also used as a herbicide, fungicide, and a rodenticide. It is also used as a poison in slug baits. Copper arsenate can also be a misnomer for copper arsenite, especially when meant as a pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub .... Natural occurrences Anhydrous copper arsenate, Cu3(AsO4)2, is found in nature as the mineral lammerite. Copper arsenate tetrahydrate, Cu3(AsO4)2·4H2O, occurs naturally as the mineral rollandite. Related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundation (architecture)
In engineering, a foundation is the element of a structure which connects it to the ground or more rarely, water (as with floating structures), transferring loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (geotechnical engineering) in the design of foundation elements of structures. Purpose Foundations provide the structure's stability from the ground: * To distribute the weight of the structure over a large area in order to avoid overloading the underlying soil (possibly causing unequal settlement). * To anchor the structure against natural forces including earthquakes, floods, droughts, frost heaves, tornadoes and wind. * To provide a level surface for construction. * To anchor the structure deeply into the ground, increasing its stability and preventing overloading. * To prevent lateral movements of the supported structure (in some cases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shake (roof)
Wood shingles are thin, tapered pieces of wood primarily used to cover roof shingle, roofs and walls of buildings to protect them from the weather. Historically roof shingle, shingles, also known as shakes, were split from straight grained, knot free ''bolts'' of wood. Today shingles are mostly made by being cut which distinguishes them from shakes, which are made by being split out of a bolt. Wooden shingle roofs were prevalent in the North American colonies (for example in the Cape Cod (house), Cape-Cod-style house), while in central and southern Europe at the same time, thatch, slate and tile were the prevalent roofing materials. In rural Scandinavia, wood shingles were a common roofing material until the 1950s. Wood shingles are susceptible to fire and cost more than other types of shingle so they are not as common today as in the past. Distinctive shingle patterns exist in various regions created by the size, shape, and application method. Special treatments such as swep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali
In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases. Etymology The word ''alkali'' is derived from Arabic ''al qalīy'' (or ''alkali''), meaning (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide (''slaked lime''), a far more strongly basic substance known as ''caustic potash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clays develop plasticity (physics), plasticity when wet but can be hardened through Pottery#Firing, firing. Clay is the longest-known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been radiocarbon dating, dated to around 14,000 BCE, and Clay tablet, clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtration, filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often baked into brick, as an essenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Contamination
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honey
Honey is a sweet and viscous substance made by several species of bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the sugary secretions of plants (primarily floral nectar) or the secretions of other insects, like the honeydew of aphids. This refinement takes place both within individual bees, through regurgitation and enzymatic activity, and during storage in the hive, through water evaporation that concentrates the honey's sugars until it is thick and viscous. Honey bees stockpile honey in the hive. Within the hive is a structure made from wax called honeycomb. The honeycomb is made up of hundreds or thousands of hexagonal cells, into which the bees regurgitate honey for storage. Other honey-producing species of bee store the substance in different structures, such as the pots made of wax and resin used by the stingless bee. Honey for human consumption is collected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beehive
A beehive is an enclosed structure which houses honey bees, subgenus '' Apis.'' Honey bees live in the beehive, raising their young and producing honey as part of their seasonal cycle. Though the word ''beehive'' is used to describe the nest of any bee colony, scientific and professional literature distinguishes ''nest'' from ''hive''. ''Nest'' is used to discuss colonies that house themselves in natural or artificial cavities or are hanging and exposed. The term ''hive'' is used to describe a manmade structure to house a honey bee nest. Several species of ''Apis'' live in colonies. But for honey production, the western honey bee (''Apis mellifera'') and the eastern honey bee (''Apis cerana'') are the main species kept in hives. The nest's internal structure is a densely packed group of hexagonal prismatic cells made of beeswax, called a honeycomb. The bees use the cells to store food (honey and pollen) and to house the brood (eggs, larvae, and pupae). Beehives serve several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Preservation
Wood preservation refers to any method or process, or even technique, used to protect the wood and extend its service life. Most wood species are susceptible to both biological (''biotic'') and non-biological (''abiotic'') factors that cause decay and/or deterioration. Only a limited number of wood species possess natural durability, and even those may not be suitable for all environments. In general, wood benefits from appropriate preservation measures. In addition to structural design considerations, a variety of chemical preservatives and treatment processes — commonly known as timber treatment, lumber treatment, pressure treatment or modification treatment — are used to enhance the durability of wood and wood-based products, including engineered wood. These treatments may involve physical, chemical, thermal, and/or biological methodology aimed at protecting wood from degradation. They increase its resistance to biological agents such as fungi, termites, and insects, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaline Copper Quaternary
Alkaline copper quaternary, usually abbreviated ACQ, is a type of water-based wood preservative product containing a soluble copper#Coordination chemistry, copper(II) complex and quaternary ammonium alkyl- or aryl-substituted compounds ("quats"). Thus the product was originally called ammoniacal copper/quaternary ammonium. Composition Copper complex The copper in the preparation is in the form of a soluble complex with ammonia or an amine such as ethanolamine . In any case, the copper content is usually expressed as a weight percentage of the amount of copper oxide that would account for the copper present. As a copper carrier, ammonia has the advantage that it will penetrate difficult-to-treat Western species better than other waterborne preservatives. Otherwise ethanolamine is preferred as copper carrier. Quaternary ammonium cations Quaternary ammonium cations DDA The quaternary ammonium cation in some formulations is didecyldimethylammonium (DDA) . DDA is commercially p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentachlorophenol
Pentachlorophenol (PCP) is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names. It can be found as pure PCP, or as the sodium salt of PCP, the latter of which dissolves easily in water. It can be biodegraded by some bacteria, including '' Sphingobium chlorophenolicum''. Uses PCP has been used as a herbicide, insecticide, fungicide, algaecide, and disinfectant and as an ingredient in antifouling paint. Some applications were in agricultural seeds (for nonfood uses), leather, masonry, wood preservation, cooling-tower water, rope, and paper. It has previously been used in the manufacture of food packaging materials. Its use has declined due to its high toxicity and slow biodegradation. Two general methods are used for preserving wood. The pressure process method involves placing wood in a pressure-treating vessel, where it is immersed in PCP and then subjected to applied pressure. In the nonpressure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
