Flakiness

CaH,3N02. White flaky or crystalline powder, m.p. 126-128°C. Used in (he treatment of barbiturate poisoning, by intravenous injection. 

Boron trioxide is not particularly soluble in water but it slowly dissolves to form both dioxo(HB02)(meta) and trioxo(H3B03) (ortho) boric acids. It is a dimorphous oxide and exists as either a glassy or a crystalline solid. Boron trioxide is an acidic oxide and combines with metal oxides and hydroxides to form borates, some of which have characteristic colours—a fact utilised in analysis as the "borax bead test , cf alumina p. 150. Boric acid. H3BO3. properly called trioxoboric acid, may be prepared by adding excess hydrochloric or sulphuric acid to a hot saturated solution of borax, sodium heptaoxotetraborate, Na2B407, when the only moderately soluble boric acid separates as white flaky crystals on cooling. Boric acid is a very weak monobasic acid it is, in fact, a Lewis acid since its acidity is due to an initial acceptance of a lone pair of electrons from water rather than direct proton donation as in the case of Lowry-Bronsted acids, i.e. 

Black phosphorus is formed when white phosphorus is heated under very high pressure (12 000 atmospheres). Black phosphorus has a well-established corrugated sheet structure with each phos phorus atom bonded to three neighbours. The bonding lorces between layers are weak and give rise to flaky crystals which conduct electricity, properties similar to those ol graphite, it is less reactive than either white or red phosphorus. 

A good compilation of the functions of fats in various food products is available (26). Some functions are quite subtle, eg, fats lend sheen, color, color development, and crystallinity. One of the principal roles is that of texture modification which includes viscosity, tenderness (shortening), control of ice crystals, elasticity, and flakiness, as in puff pastry. Fats also contribute to moisture retention, flavor in cultured dairy products, and heat transfer in deep fried foods. For the new technology of microwave cooking, fats assist in the distribution of the heating patterns of microwave cooking. 

The Bollman-type extractor shown in Fig. 18-76 is a bucket-elevator unit designed to handle about 2000 to 20,000 kg/h (50 to 500 U.S. tons/day) of flaky solids (e.g., soybeans). Buckets with perforated... 

Smooth jaws produce more numerous flaky pieces than corrugated jaws. Curved jaws produce less fines but more numerous flaky particles. Crusher speed has little effect. The presence of material too small to be crushed has a deleterious effect on the shape of products. Secondary crushers with a small reduction ratio can improve the shape of primaiy crushed material, but secondaiy crushers are not inherently different from primaiy crushers. Slotted screens can remove flaky particles from the product. Impact crushers produce fewer flaky particles than any other type. 

The condition of the curd on precipitation is important. As the milk starts to gel, agitators in the coagulation tanks are started as the temperature is raised to about 65°C. Under these conditions the protein is thrown out in fine particles. Too slow an agitation will produce large clots difficult to wash whilst too fine a curd also presents washing problems. In order to obtain the requisite consistency of the precipitate it may be necessary to add inorganic material to the skimmed milk. For example, the addition of phosphate ions will prevent undesirable flaky polymer. Similarly, calcium-deficient casein will not coagulate satisfactorily and the addition of calcium ions may be necessary. 

Filtration may also serve as the preparatory step for the operation following it. The latter stages may be drying or incineration of solids, concentration or direct use of the filtrate. Filtration equipment must be selected on the basis of their ability to deliver the best feed material to the next step. Dry, thin, porous, flaky cakes are best suited for drying where grinding operations are not employed. In such cases, the cake will not ball up, and quick drying can be achieved. A clear, concentrated filtrate often aids downstream treatment, whereby the filter can be operated to increase the efficiency of the downstream equipment without affecting its own efficiency. 

The factor iji < 1 must be determined experimentally for particles of interest. Typical values are iji = 0.77 for particles of rounded shape iji = 0.66 for particles of angular shape iji = 0.43 for particles of a flaky geometry. 

Substantial differences were observed in the reactions. The fine-fine and flaky-medium mixtures were observed to be fully reacted under conditions in which reaction was observed only in the elevated temperature region in the outer edge of the samples. Thus, the threshold shock pressures or temperatures of the reactions were observed to be substantially lowered with these morphologies. 

Fig. 8.7. The influence of powder morphology (configuration) on shock modification controlling initiation of reaction is shown by the thermal response of mixed Ni-Al powders of different morphologies. The preinitiation event shown in Fig. 8.5 is observed to be strongly influenced by morphology at fixed shoek condition. The eoarse-medium mixture shows the largest preinitiation event [91D01]. The data show mueh larger preinitiation events for the flaky and fine morphologies.

Partiele shape ean be deseribed qualitatively using standards terms sueh as granular, flaky, needle, ete. (BS 2955). Quantitative deseription, however, requires use of shape faetors that enables a partiele s surfaee area and volume to be ealeulated on knowing its size . 

Orthoboric acid, B(OH)3, is the normal end product of hydrolysis of most boron compounds and is usually made ( 160 000 tonnes pa) by acidification of aqueous solutions of borax. Price depends on quality, being 805 per tonne for technical grade and about twice that for refined material (1990). It forms flaky, white, transparent crystals in which a planar array of BO3 units is joined by unsymmetrical H bonds as shown in Fig. 6.25. In contrast to the short O—H O distance of 272 pm within the plane, the distance between consecutive layers in the ciystal is 318 pm, thus accounting for the pronounced basal cleavage of the waxy, plate-like ciystals, and their low density (1.48 g cm ). B(OH)3 is a very weak monobasic acid and acts exclusively by hydroxyl-ion acceptance rather than proton donation ... 

Flocken-salpeter, m. efflorescent saltpeter, -stoff, m. (Textiles) nap cloth, flockig, a. flocculent, flocky, flaky, -kasig, a. curdy. 

Napfehen, n. cup little bowl or basin blank (for blasting caps) cupule. -kobalt, m. flaky metallic arsenic. 

Reprecipitation from acetone/pentane is repeatedly effected until the condensation product suits in flaky form. Further purification is effected in that the crude product is chromatographed on silica gel. The fractions which are uniform in accordance with thin layer chromatography are combined and yield crystals from absolute alcohol. Pure 4 -demethylepipo-dophyllotoxin-/3-D-thenylidene glucoside has a melting point of 242°C to 246°C (last residue up to 255°C). 

The ideal deposit for analytical purposes is adherent, dense, and smooth in this form it is readily washed without loss. Flaky, spongy, powdery, or granular deposits adhere only loosely to the electrode, and for this and other reasons should be avoided. 

As far as conducting fillers are concerned, we have rather a wide range of choice. In addition to the traditional and long used fillers, such as carbon black and metal powders [13] fiber and flaky fillers on organic or metal bases, conducting textures, etc recently appeared and came into use. The shape of the filler particles varies widely, but only the particle aspect ratio, the main parameter which determines the probability... 

At present, the most promising fillers are those with 1/d P 1, i.e. fibers and flaky fillers that make it possible to reduce filler concentration in a composite and, thus, facilitate the processing and improve physical-mechanical properties [17]. Besides cut carbon fibers, carbon fibers coated with a layer of Ni that have higher conductivity have been developed (American cyanamid) [14]. Glass fibers with a layer of aluminium (MB Associates, Lundy Electronics) [16] are in production. 

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