Grains, porous

Tripoli. TripoH [1317-95-9] is a fine grained, porous, decomposed siHceous rock produced mainly in Arkansas, Illinois, and Oklahoma. It is widely used for polishing and buffing metals, lacquer finishing, and plated products. Since tripoH particles are rounded, not sharp, it has a mild abrasive action particularly suited for polishing. TripoH is also used in toothpastes, in jewelry polishing, and as filler in paints, plastics, and mbber. Rottenstone and amorphous siHca are similar to tripoH and find the same uses. In 1987 the abrasive use of tripoH in the United States totaled 26.6 million tons and was valued at about 3.1 million however, the portion used as a filler totaled 71.1 million tons and had a value of almost 10 million (4). 

In the Solar System the bulk elemental composition of the most volatile-rich Cl chondrites resembles closely that of the solar photosphere. Indeed, models that follow the condensation of a solar-composition hot gas reproduce many of the minerals and abundance trends observed in the Solar System. These are also consistent with some of the astronomical observations of dust in protoplanetary disks. Stardust grains also show approximately solar bulk composition in the measurable elements, albeit with some variations (Flynn et al 2006). Some IDPs -mainly the fine-grained, porous, and anhydrous particles - match the solar elemental... 

In ceramics, the term firing implies heat treatment of green ware which is thereby strengthened. In this way its shape is fixed and its characteristic properties are created. The process of spontaneous strengthening of fine-grained porous bodies through the effect of elevated temperature is called sintering. 

Grains, porous catalysts 28-P-12 Heteropoly acids, encapsulated 23-P-19... 

To reveal the reason of the decreased Cu film density we investigated its structure by SPM. Fig. 2 shows the SPM image of the copper film deposited on n+-type PS layer of 30 % porosity. The deposit is a grained porous film. The same porous structure was revealed for all Cu films deposited onto the n+-type PS samples. As for Cu films deposited on the p+-type PS, its porosity was quite low especially for the samples with more than 3 min of deposition time. The value of copper film porosity explains the difference of corrosive and bulk... 

As a consequence of this type of interaction, the formation of an inner, fine-grained, porous partial layer starts, which fills the gap between the metal and the compact, outward-growing FeS scale. The steps described so far are schematically illustrated by Figs. 2-38 and 2-39. In later steps, even on the porous inner partial layer, a new, out-... 

The simplest way of introducing Che pore size distribution into the model is to permit just two possible sizes--Tnlcropores and macropotes--and this simple pore size distribution is not wholly unrealistic, since pelleted materials are prepared by compressing powder particles which are themselves porous on a much smaller scale. The small pores within the powder grains are then the micropores, while the interstices between adjacent grains form the macropores. An early and well known model due to Wakao and Smith [32] represents such a material by the Idealized structure shown in Figure 8,2,... 

Water-Vapor Permeability. Water-vapor permeabiUty depends on the polymer used for the coating layer and its stmcture. Vinyl-coated fabrics have Httie water-vapor permeabiUty due to the coating layer. Although polyurethane polymer is water-vapor permeable, urethane-coated fabrics also have low permeabiUty values due to their soHd layer stmcture. On the other hand, man-made leathers have good permeabiUty values as high as that of leather due to their porous layer stmcture. The permeabiUty of grain-type is lower than that of suede-type, influenced by finishing method. 

Fig. 1. Stiength-ieducing flaws commonly found in ceramics (a) large grain surrounded by fine-grain matrix (b) porous region resulting from incomplete...

Important applieations of (4.53) are the generation of porous Hugoniots and their subsequent inversion via (4.53) to obtain yo or y(V). Critieal to this applieation is the requirement that the length seale of the porosity or grain... 

The porosity of a filter mass is an important factor. This property is best defined by experiment. A general rule of thumb is that for masses with the effective size greater than 0.4 - 0.5 mm and a specific maximum diameter below 1.2 mm the porosity is generally between 40 and 55 % of the total volume of the filter mass. Layers with spherical grains are less porous than those with angular material. 

It consists of a porous cell which foims the cathode chamber and contains 20 grams nitrobenzene and 160 grains 2 5 per cent, caustic soda solution. The two aie kept well mixed throughout the operation by a rapidly revolving stinei. The cathode is a cylinder of nickel gauze (12 cms. x S 5 cms. = too sq. cms.). The anode chamber is the outer glass vessel or beaker. 

Gross-koks, m. large-sized coke, (blast) furnace coke, -kraftwerk, n. large power station, gross-luckig, a. coarsely porous coarse-grained. 

Klein-lader, m. Elec.) trickle charger, -leb wesen, n. microorganism, kleinlich, a. petty, paltry, mean. KleinlichtbildkuzLSt,/. microphotography. klein-luckig, a. finely porous close-grained. 

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