Compositional modifications

Secondary smoke is produced mosdy by the condensation of water in humid or cold air. The presence of hydrogen chloride or hydrogen fluoride in the combustion products increases the extent and rate of condensation. Composition modifications to reduce primary smoke may reduce secondary smoke to some extent, but complete elimination is unlikely. The relatively small amount of smoke produced in gun firings by modem nitrocellulose propellants, although undesirable, is acceptable (102—109). 

Historically, materials based on doped barium titanate were used to achieve dielectric constants as high as 2,000 to 10,000. The high dielectric constants result from ionic polarization and the stress enhancement of k associated with the fine-grain size of the material. The specific dielectric properties are obtained through compositional modifications, ie, the inclusion of various additives at different doping levels. For example, additions of strontium titanate to barium titanate shift the Curie point, the temperature at which the ferroelectric to paraelectric phase transition occurs and the maximum dielectric constant is typically observed, to lower temperature as shown in Figure 1 (2). 

Fig. 8.27 Some compositional modifications of 18/8 austenitic stainless steel to produce special properties. Dashed lines show compositional links to other alloy systems (after...

Some synonyms in the Alphabetical index are followed by bracketed notations. These notations provide additional clarifying information about the entry such as composition, modifications to the agents (e.g., thickened, dusty, binary), or a note for historical context. For example, "White Star" was a gas blend that was employed by the British in World War I consisting of 50% phosgene and 50% chlorine. The entry appears as ... 

Solders and brazes for jewelry gold alloys are usually gold—silver—copper alloys that can be modified to yield a desired melting range by adjusting the silver-to-copper ratio. Additions of zinc, cadmium, tin, or nickel compensate for the changes in color introduced by compositional modification (87). 

The free radical polymerization of DADMAC (M,) with vinyl acetate (M2) in methanol proceeds as a nonideal and nonazeotropic copolymerization with monomer reactivity ratios rx=1.95 and r2=0.35 were obtained [75]. The resulting low molar mass copolymers were reported to be water soluble over their whole range of composition. Modification of the vinyl acetate unit by hydrolysis, ace-talization, and acylation resulted in DADMAC products with changed hydrophilic or polyelectrolyte properties [75]. For the copolymerization of DADMAC and AT-methyl-AT-vinylacetamide (NMVA) a nearly ideal copolymerization behavior could be identified [45]. The application properties of the various copolymer products will be discussed in Sect. 8. 

Since caspase 14 plays an important role in epidermal keratinocyte terminal differentiation and denucleation, the effect of topical application of GTPs, with 40% EGCG, on the psoriasis symptoms in flaky skin mice was tested in this in vivo pilot study. The rationale for using GTPs instead of purified EGCG is that GTPs are naturally available without any chemical or compositional modification. 

Compositional modification frequently, by ligand exchange and incorporation of solvent possible with volatiles, frequently with compounds by thermochemical reduction... 

Rousseau, D., Marangoni, A.G. 1998a. Tailoring attributes of butter fat/canola oil blends via Rhizopus arrhizus lipase-catalyzed interesterification. 1. Compositional modifications. J. Agric. Food Chem. 46, 2368—2374. 

Membrane Lipid composition modification Increased liposome stability,... 

Tendency for Lipid composition modification, Formation of structures (as... 

Several reviews have addressed the effect of aerobic exercise on body weight and composition modification (18,25,26,27). A summary of 32 studies Involving adult males, adult females, and children is presented in Table I. The studies ranged from 8 to 20... 

The materials described below include diamond, cubic BN (the hardest material next to diamond), SrCu02 (from which two types of superconductors have been derived by compositional modification), MgSiOs (a geologically interesting perovskite), and Ge02 (amorphized underpressure at room temperature). 

As part of powder beneficiation, compositional modification may also be performed by the addition of second phases, dopants, etc. These changes may be required to influence the sintering behavior of the ceramic powders or to tailor the structural, thermal, electrical, and optical properties of the ceramic products. The source of these additives may be from powders such as oxides, glasses, or salts. To remove unwanted impurities, second phases, surface contaminants, or other by-products, powders may beneficiated by washing, sedimentation, filtration, and magnetic separation. 

Standard penetrator material [6.29]. Nevertheless, recent environmental considerations have put a strong emphasis on substituting depleted uranium by heavy metals because of its radioactivity. Efforts to improve the ballistic performance through proper processing and compositional modifications have failed [6.29,6.39]. Recent research has therefore focused on alternative matrix alloys, such as tungsten-hafhium, tungsten-uranium composites [6.29], or heavy metal alloys with a spiculating core of WC [6.41]. 

Hyman B, Spector A. Choline uptake in cultured human Y79 retinoblastoma cells effect of polyunsaturated fatty acid compositional modifications. J Neurochem 1982 38 650-656. 

Marita, J. M., Ralph, J., Hatfield, R. D., Guo, D., Chen, R, and Dixon, R. A. (2003) Structural and compositional modifications in lignin of transgenic alfalfa down-regulated in caffeic acid 3-0-methyltransferase and caffeoyl coenzyme A 3-O-methyltransferase. Phytochem. 62(1), 53-65. 

By definition, the intrinsically high surface area of gels requires that gases are accessible to a substantial portion of the solid phase. For example, in a gel with a Brunauer-Emmett-Teller (BET) surface area of 850 m2/g, 65% of the silicon atoms are on a surface. The accessibility of the surface makes gas- or liquid-phase reactions a viable means of bulk compositional modification. This situation has been exploited by numerous researchers who have reacted silicate xerogels with ammonia to form oxynitride glasses without melting (105-107). 

Oxidative instability limits the use of soybean oil in certain applications, but hydrogenation and other means of composition modification have made soybean oils the most widely used of all vegetable oils. The following analytical methods are frequently used to quantify oxidation of soybean oil. 

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