Combination mats

Fibrous reinforced plates, fiat or curved, is commonly made with mat, fabrics, and parallel filaments, either alone or in combination. Mat is usually used for good strength at minimum cost, fabrics for high strength, and parallel filaments for maximum strength in some particular direction. 

Because the fibers in mat are randomly oriented, mat-reinforced materials have essentially the same strength and elastic properties in all directions in the plane of the plate, that is, they are essentially isotropic in the plane. Consequently, the usual engineering theories and design methods employed for isotropic engineering materials may be applied. It is only necessary to know strength, modulus of elasticity, shearing modulus, and Poisson s ratio of the combined mat and resin. These can be obtained from standard stress-strain measurements made on specimens of the particular combination of fiber and plastic under consideration. 

BHA-TEX, PTFE membrane, BHA Group, Inc. BHEB, Antioxidant, Aceto Chemical Co. Bi-Hy, Combination mat/woven roving, Owens Coming... 

One disadvantage of the uniaxial structure is that the stiffness and the strength in the transversal direction are markedly inferior (see sections 9.2.2 and 9.3.6). For this reason, different orientations of the fibres may be combined. Mats containing uniaxial fibres are stacked on top of each other to form laminates, or the fibres can be woven to fabrics that can be laminated again. The orientation of the fibres within the layers can be chosen orthogonal to each other or in more complex ways (for example, with relative orientations of 45°). The properties of such a material can be isotropic within the plane of the fibres, but they are weaker perpendicular to them because there are no fibres in this direction. To make the material isotropic, it is necessary to arrange the fibres in all three directions, but this is rather difficult to achieve with continuous fibres because the fibres have to be woven in three directions. 

Betamate Structural adhesives, Dow Betaseal Glass bonding systems, Dow Bi-Ply Combination mat/woven roving, Owens Corning Bicor Biaxially oriented polypropylene, Mobil Black Pearls Pelletized carbon black, Cabot... 

Combinations of these two types of reinforcement exist in the form of "combination mats and their properties tend to be the aggregate of the individual materials. Since many permutations are possible and few preferred types have emerged within the industry, some characteristic data are described. 

Oxide fibers are manufactured by thermal or chemical processes into a loose wool mat, which can then be fabricated into a flexible blanket combined with binders and formed into boards, felts, and rigid shapes or fabricated into ropes, textiles and papers. The excellent thermal properties of these products make them invaluable for high temperature industrial appHcations. 

Both fiber-glass mats and polyester mats are used either individually or combined in SBS membrane sheets. Because of the elastomedc properties of the asphalt, SBS sheets have developed a reputation as being very tough and abuse-resistant. However, they do not have any better ultraviolet resistance than conventional asphalts, so most of the SBS sheets come with a factory-appHed surfacing of granules. 

Ball mills or tube mills can be operated in closed circuit with external air classifiers with or without air sweeping being employed. If air sweeping is employed, a cyclone separator may Be placed between mill and classifier. (The principles of size reduction combined with size classification are discussea under Characteristics of Size Classifiers. ) Likewise other types of grinding mill can be operated in closed circmt with external size classifiers (Fig. 20-12), as will be described at appropriate places on succeeding pages. However, many types of grinders are air-swept and are so closely coupled with their classifiers mat the latter are termed internal classifiers. 

The resulting slurry was extracted with four 300 ml portions of chloroform. The aqueous phase was discarded. The combined chloroform extract was washed once with 100 ml of saturated aqueous sodium chloride solution and the sodium chloride phase was discarded. The chloroform phase was evaporated to dryness under vacuum on a 50° to 60°C water bath and an equal volume of methanol was added to the residue and the resulting solution heated at reflux for 1 hour. The methanol solution was evaporated to dryness under vacuum on a 50° to 60°C water bath. The residue was a clear pale yellow viscous oil. An equal volume of water and 10 ml of 37% aqueous HCI was added and the resultant was shaken until the oil dissolved and a white solid (more 0jPO) remained in suspension. The suspension was filtered through a sintered glass mat at pH 1 to 2 and the solid discarded. 

Microactivity Test (MAT) is a small, packed-bed catalytic cracking test that measures activity and selectivity of a feedstock-catalyst combination. 

For the treatment of AIDS, TDF is now available in three commercial preparations, as such (Viread ), in combmation with emtricitabine (Truvada ) and m combination with emtricitabme and efavirenz (Atripla ). The latter represents a three-drugs-in-once combination piU, which has become available for the treatment of AIDS since July 2006. The different milestones mat marked the development and ultimate commercialization of Atripla (m 2006) smce the original identification of adefovir as an antiretroviral agent (m 1986) have been previously reviewed (De Clercq 2006, 2007a-c). 

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