The effect of chemical composition

Hydrolysis oftricaprylin in trimethylpentane by Fusarium solani pisi recombinant cutinase immobilized on various zeolites (NaA, NaX, NaY, LZY-82, dealuminated Y) was investigated in order to assess the effect of chemical composition (Si/Al ratio), hydrophilic character and acidity on the catalytic activity [221]. The adsorption of... 

To study the effect of chemical composition on sulfur distribution during pyrolysis, it appeared desirable to study the pyrolysis of sulfur-containing model compounds of well-defined structure. The correlation of chemical composition and sulfur distribution during pyrolysis is the subject of this paper. 

There is a considerable literature on the effect of chemical composition on Tg. A number of factors have been shown to influence Tg, including backbone flexibility, steric effects, polarity, pendant groups, crystallinity, plasticizers, crosslink density, and co-polymerization (13,5). After a brief qualitative discussion of the first few factors, we will consider the last two in more detail. 

Warakomski, J and Dion R (1992) The effect of chemical composition on the miscibility of styrene/acrylonitrile/fumaronitrile terpolymers with styrene/acryloni-trile copolymers. J Appl Polym Sci 46 1057-63. 

The polymer materials mainly used for the membranes are glassy polymers, the first and foremost polyimides. The use of glassy polymers having a rigid ensemble of macromolecules results in high separation effectiveness. Separation effectiveness in pervaporation processes is characterized by the separation factor, /3p, which is determined by the diffusion component, /3d, and the sorption component, /3s [8,55]. Let us consider the effect of chemical composition of polymer membranes on their transport properties with respect to aromatic, alicyclic, aliphatic hydrocarbons and analyze ways to improve these properties. 

Table 5.4 shows the clear influence of PCc content on the microhardness. The dominating contribution of crystallinity in the mechanical properties of polymers is well known. Therefore, to understand better the correlation between the chemical composition and the microhardness of the copolymers one has first to examine the behaviour of the crystalline phase. Figure 5.12 shows the nearly parallel dependence of the microhardness and the crystallinity on the PCc content within the copolymers. H drops continuously with increasing PCc wt% almost in the same manner as the crystallinity does. Such a parallel behaviour of H and Wc shows that the effect of chemical composition on the microhardness is transferred via the crystallinity. 

A group of new, fully miscible, polymer blends consisting of various styrene-maleic anhydride terpolymers blended with styrene-acrylonitrile copolymer and rubber-modified versions of these materials have been prepared and investigated. In particular the effects of chemical composition of the components on heat resistance and the miscibility behavior of the blends have been elucidated. Toughness and response to elevated temperature air aging are also examined. Appropriate combinations of the components may be melt blended to provide an enhanced balance of heat resistance, chemical resistance, and toughness. 

The Navy has been interested in the use of alternate fossil fuels for sometime (1-4). Our interest is focused primarily in establishing the effects of chemical composition on fuel properties since such relations will lead to greater availability and better use of fuels. We recently reported some of our results on jet fuels derived from coal, tar sands and oil shale (1). Other papers in this series report on some aspects of oil shale derived fuels obtained from a large production experiment, Shale II, performed by Paraho, Inc. (, 6). In this paper, we report on some aspects of stability of a jet fuel prepared in an earlier Navy Program, Shale-I (3). 

The effect of chemical composition, and dose on a range of different poly(butadiene) samples was also examined by these authors. Similar results were obtained for cis- and trans-l,4-poly(butadiene), however, even larger G-values were measured for 1,2-poly(butadiene), presumably because of the higher reactivity of pendant vinyl groups compared with internal double bonds and the close proximity of side-chains allowing a zipping chain reaction. Among... 

Corrosion Testing Objectives of SCC testing are (i) determination of the risk of SCC for a given application and comparison of alloys (ii) examination of the effects of chemical composition, metallurgical processing, fabrication practices for structural components (iii) evaluation of protective systems and prediction of service life (iv) development of new alloys, which are less expensive, and offer a longer, safer, and efficient performance for chosen environments (v) evaluation of claims for SCC performance of improved mill products. 

Table 93 Fractal dimensions for compounds found in fly ash [90]. Reproduced with permission of American Association of Aerosol Research The effect of chemical composition on the fractal-like structure of combustion-generated inorganic aerosols. Aerosol Set TechnoL, 33, 459 69 . Copyright 2000. Mount Laurel, NJ.

The effect of chemical composition of a zeolite on its average Bronsted acidity, can be accounted for by its average Sanderson electronegativity, allowing... 

Although there have been quite a number of studies on the WPCs as new generation of reinforcing materials in recent years, so far, not much attention has been paid to the effect of chemical composition of wood on the mechanical and physical properties. The effective use of wood-based particles and fibres as fillers or reinforcements in thermoplastic composites requires a fundamental understanding of... 

Effect of chemical composition and structure of porous media During the past few years the effect of chemical composition of rocks has been studied Intensively. Sandstones, carbonates, silica and different clay minerals were used as adsorbents (6,9,12,18,19, 35). The conclusions do not show any divergence. To give a comprehensive picture of the adsorption of polyacrylamides, some data are given in Table 2 for the effect of adsorbent type on amount of different polymers adsorbed. 

M. Watanabe, R. V. Caporali, and R. E. Mould, The Effect of Chemical Composition on the Strength and Static Fatigue of Soda-Lime Glass, Phys. Chem. Glasses, 2 12-23 (1961). 

To assess the effect of chemical composition on carbon deposit, the relationship between chemical group concentration and the deposit amount was plotted. A plot of deposit versus palmitic acid for each oil shows that the carbon deposit amount increases as the palmitic acid concentration increases (tig. 14.2) = 0.87). No rela-... 

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