Ground powder

Niobium pentoxide also is reduced to metal commercially by the aluminothermic process. The finely ground powder is mixed with atomized aluminum and an accelerator compound which gives extra heat during reaction, then is ignited. The reaction is completed quickly and, after cooling, the slag is broken loose to free the metal derby which is purified by electron-beam melting. 

Catalyst pellets often operate with internal temperatures that are substantially different from the bulk gas temperature. Large heats of reaction and the low thermal conductivities typical of catalyst supports make temperature gradients likely in all but the hnely ground powders used for intrinsic kinetic studies. There may also be a him resistance to heat transfer at the external surface of the catalyst. 

Paprika contains capsombin and capsanthin (Fig. 8.3) which occur mainly as the lauric acid esters, and about 20 other carotenoid pigments. Paprika is produced in many countries which have developed their own specialties. Cayenne or cayenne pepper, produced from a different cultivar of C. annum, is usually more pungent. C. frutescens is the source of the very pungent Tabasco sauce. Paprika oleoresin is produced by solvent extraction of the ground powder. Obviously paprika supplies both flavor and color and its use is limited to those products compatible with the flavor. The recent rise in demand for tomato products in the form of pizza, salsa, etc., has increased the demand for paprika. Paprika is used in meat products, soups, sauces, salad dressings, processed cheese, snacks, confectionery and baked goods.1018... 

Pour exactly lOmL of 1% ammonia in dimethylsulfoxide (DMSO) into the ground powder and sonicate it in an ultrasonic bath for two minutes. Add exactly 90mL of 2% acetic acid in water to the mixture. Stir it with a magnetic stir bar for 1 min. 

Scheme 3 The solid yielded by mechanical mixing of the reactants can be used to seed crystal growth from solution to obtain crystals for single-crystal X-ray diffraction experiments. This procedure allows one to compare the X-ray powder diffraction pattern measured on the mechanochemical sample with that calculated on the basis of the single-crystal experiment for the solids obtained by crystallization via seeding of a solution of the ground powder of the adduct...

The particle shape and size of the raw and ground powder samples of Sm2Fe17Ny (y 3) are shown in Figure 10.9. Ball-milling in solvents easily produces fine powder materials with smaller amounts of strain than materials obtained by solution-free ball-milling, vibrating milling, and jet... 

The most common method for the estimation of SVOC/POM content in material samples is solvent extraction of small pieces or finely ground powder of the material. The VOC content of PVC has been estimated in PVC powder which was obtained by liquid nitrogen cooling of the material before grinding (Cox, Little and Hodgson, 2001). Preferred extraction methods are PLE and SEE, since they are very efficient. The materials must be extracted and the extracts analyzed several times to be able to estimate the number of extraction cycles needed for an exhaustive extraction. 

Ray and Kumar-De [54] described an HPTLC method and a TLC method for the rapid quantification and identification of omeprazole. Ground powder (omeprazole powders, capsules, or tablets) equivalent of 25 mg omeprazole was warmed for 10 min with shaking with 25 ml methanol. After cooling the solution was made up to 50 ml with methanol, mixed and filtered. The filtrate was spotted (2 ji ) on to HPTLC plates (20 x 20 cm) coated with Kieselgel 60 GF254 activated at 110 °C for 30 min. The plates were developed to 16 cm with methanol-water (2 1) as mobile phase. After development, the plates were dried in warm air and the spots were visualized at 302 nm. The calibration graph was linear from 2.5 to 10 jig omeprazole and the RSD was <0.60%. The recovery was 99.42%. Results compared well with those obtained by elution of the spots with methanol following TLC and spectrophotometric detection at 302 nm. 

The color of most Pc s ranges from blue-black to metallic bronze, depending on the manufacturing process. Ground powders exhibit colors from green to blue. Most compounds do not melt but sublime above 200°C, which can be used for purification. 

ISO 972 1997 Chillies and capsicums, whole or ground (powdered) - specification ISO 7540 1984 Ground (powdered) paprika (Capsicum annuum L.) - specification ISO 3588 1977 Determination of degree of fineness of grinding - hand-sieving method (reference method)... 

ISO 7542 1984 Ground (powdered) paprika (Capsicum annuum L.) - microscopical examination... 

ISO 7541 1989 Ground (powdered) paprika - determination of total natural colouring matter content... 

A third experiment was conducted to study the effect of compaction upon suspensibility. To reduce costs of ocean shipment, all industrial powders are compacted at the time of manufacture. Although the effects of compaction are unclear, the current practice is to compact immediately after air milling. Miles et al (2) have shown that compaction decreases suspensibility when the formulation is subjected to conditions of tropical storage however, their observations were made on aged formulations. This experiment, which is an extension of their work, used freshly ground powder to study the effect of the time interval between milling and compacting on suspensibility. 

Dicyandiamide (sometimes referred to as dicy ) or its derivatives are used in most commercial one-component epoxy adhesives. This curative is a white crystalline solid and is easy to incorporate into an epoxy formulation as a finely ground powder. When cured with epoxy resin, dicyandiamide provides an excellent set of performance properties. 

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