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Thermally Modified Wood
Thermally modified wood is engineered wood that has been modified by a controlled pyrolysis process of wood being heated to temperatures above in an oxygen free atmosphere. This process changes to the chemical structures of wood's cell wall components lignin, cellulose and hemicellulose which decreases its hygroscopy and thus increases dimensional stability. Low oxygen content prevents the wood from burning at these high temperatures. Several different technologies use different media including nitrogen gas, steam and hot oil. All processes degrade strength and toughness of the treated lumber to some degree. Modification processes In 1946 the US Forest Service conducted partially successful experiments by submersing wood in a liquid metal alloy (zinc, lead and cadmium) to produce a ''heat stabilized'' product (proposed to be named ''staybwood'') and concluded: A process of thermal modification of pressurized wood with a medium moisture content was described in a paper by Bur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Products Laboratory
The Forest Products Laboratory (FPL) is the national research laboratory of the United States Forest Service, which is part of USDA. Since its opening in 1910, the FPL has provided scientific research on wood, wood products and their commercial uses in partnership with academia, industry, tribal, state, local and other government agencies. The laboratory is headquartered in Madison, Wisconsin. The focus of the Forest Products Laboratory is to promote healthy forests and forest-based economies through the efficient, sustainable use of the Nation's wood resources. History By the late 1800s, awareness was growing that timber resources were finite and careful use could extend them. In 1887 B.E. Fernow, chief of the Division of Forestry in the Department of Agriculture reported: The properties upon which the use of wood, its technology, are based, should be well known to the forest manager if he wishes to produce a crop of given quality useful for definite purposes. Our ignoranc ... [...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] |
Preparation
Preparation may refer to: * Preparation (dental), the method by which a tooth is prepared when removing decay and designing a form that will provide adequate retention for a dental restoration * Preparation (music), treatment of dissonance in tonal music * Preparation, Iowa, a ghost town * Preparation time, time to prepare speeches in policy debate * '' The Preparation'', a 2017 South Korean film * ''Preparations'' (album), a 2007 album by Prefuse 73 * Prepared dosage form * Prepared drug * Prepared food * Prepared supplement * Special modifications to instruments, see **Prepared piano **Prepared guitar *Fossil preparation See also * Preparation H, popular hemorrhoids medicine * Preparation for the Gospel, early Christian book * * Prep (other) * Preparationism Preparationism is the view in Christian theology that unregenerate people can take steps in preparation for conversion, and should be exhorted to do so. Preparationism advocates a series of things that people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Resources Research Institute
The Natural Resources Research Institute (NRRI) is a United States (U.S.) based research institute founded by the Minnesota state legislature within the University of Minnesota Duluth. NRRI is a non-profit, applied research organization, established with a mission to improve the economy of Minnesota. The Institute aims to help launch small businesses and provides ongoing research and development assistance. History The mid- to late-1970s and early-1980s were particularly difficult times for Minnesota's natural resource-based industries, especially for the taconite mining industry. In the face of a domestic steel crisis, shipments of iron ore from Northeastern Minnesota's eight taconite plants plummeted. Growth in the taconite industry, which had begun in the 1950s, ended and employment in this critical base industry dropped from about 16,000 to 3,000. About 2,000 supply companies on the Iron Range, in Duluth and elsewhere in the state were also critically impacted. Perhaps no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatile Organic Compound
Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. They are common and exist in a variety of settings and products, not limited to Indoor mold, house mold, Upholstery, upholstered furniture, Handicraft, arts and crafts supplies, Dry cleaning, dry cleaned clothing, and Cleaning agent, cleaning supplies. VOCs are responsible for the odor of scents and perfumes as well as pollutants. They play an important role in communication between animals and plants, such as attractants for pollinators, protection from predation, and even inter-plant interactions. Some VOCs are dangerous to human health or cause harm to the natural environment, environment, often despite the odor being perceived as pleasant, such as "new car smell". Human impact on the environment, Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Most VOCs are not acutely toxic, but may have long-term chronic health effect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Softwood
Scots pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the softwoods completely lack vessels (pores). The main softwood species (pines, spruces, larches, false tsugas) also have resin canals (or ducts) in their structure. Characteristics Softwood is wood from gymnosperm trees such as pines and spruces. Softwoods are not necessarily softer than hardwoods. The hardest hardwoods are much harder than any softwood, but in both groups there is enormous variation with the range of wood hardness of the two groups overlapping. For example, balsa wood, which is a hardwood, is softer than most softwoods, whereas the longleaf pine, Douglas fir, and yew softwoods are much harder than several hardwoods. Several specific natural, macroscopic and microscopic features of wood are used in the identification p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torrefaction
Torrefaction of biomass, e.g., wood or grain, is a mild form of pyrolysis at temperatures typically between 200 and 320 °C. Torrefaction changes biomass properties to provide a better fuel quality for combustion and gasification applications. Torrefaction produces a relatively dry product, which reduces or eliminates its potential for organic decomposition. Torrefaction combined with densification creates an energy-dense fuel carrier of 20 to 21 GJ/ton lower heating value (LHV). Torrefaction causes the material to undergo Maillard reactions. Torrefied biomass can be used as an energy carrier or as a feedstock used in the production of bio-based fuels and chemicals. Biomass can be an important energy source. However, there exists a large diversity of potential biomass sources, each with its own unique characteristics. To create efficient biomass-to-energy chains, torrefaction of biomass, combined with densification ( pelletisation or briquetting), is a promising ste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
