Composites structural parameters affecting

Structural Parameters Affecting the Brittleness of Polymer Glasses and Composites... 

However, the structure of vanadium phosphate catalysts is dependent on a number of considerations. The P/V stoichiometry, thermal treatment time, activation temperature, and gas-phase composition can all affect catalyst composition. By varying these synthesis parameters, researchers have prepared a variety of crystalline phases and identified them by X-ray diffraction in the freshly activated catalysts. 

In principle, many factors affect the rate of degradation of PHAs. They include the properties of the polymers, such as the molecular composition, the resulting intermo-lecular interactions, hydrophilic and hydrophobic behavior, the structural parameters, like degree of crystallinity, level of orientation, surface structure, and molecular weight. Concerning biopolymers, the related factors are the growth of microorganisms, especially the pH-value, temperature, aerobic or anaerobic conditions etc. 

The complex phenomena associated with the interaction of ionizing radiation with diverse liquids and solids, addressed in detail elsewhere in this book, are relevant and applicable to irradiated chilled or frozen foods. Specific influences of the food composition and structure directly affect the nature and reaction of the resulting free radicals formed [1]. Irradiation parameters and conditions further affect the reaction pathways of the radicals and the yield of stable products derived from them [2, 3]. 

Since the quantitative composition analysis of a copolymer relies on the use of relative peak intensities, the mass spectra pattern variation can clearly alter the composition results. The EO/PO copolymer examined in these investigations is composed of structurally similar monomers, but for other types of copolymer, with greater variability in monomer structures, even larger spectral variations are expected. It is clear that a better understanding of how experimental parameters affect the mass spectra pattern will facilitate the search of conditions under which reproducible results can be obtained. Once the reproducible spectra can be obtained, it is then possible to explore the use of other techniques such as NMR to correlate the relative peak intensities in MALDl mass spectra with actual copolymer composition. The validated MALDl method should provide a means of accurate and rapid analysis of copolymer composition. 

Approximately 10% of the human population (with regional differences indicating both genetic and environmental factors [33]) is affected by the formation of stones or calculi in the urinary tract. Urolithiasis is not only a painful condition, but also causes annual costs to the health system in the order of billions of dollars in the USA alone [34, 35]. Based on their composition, structure and location in the urinary tract, renal stones have been classified into 11 groups and their formation mechanisms have been discussed together with alterations in urinary parameters and metabolic risk factors for renal lithiasis [35]. Approximately 70% of these stones contain calcium oxalate monohydrate (COM) and dihydrate as major components, while other calculi are composed of ammonium magnesium phosphate (struvite), calcium phosphates (hydroxyapatite and brushite), uric acid and urates, cystine and xanthine. An accurate knowledge of the solubilities of these substances is necessary to understand the cause of renal or bladder calculi formation and find ways towards its prevention and treatment [36]. 

Tan, X., Chen, X., 2005. Parameters affecting energy absorption and deformation in textile composite cellular structures. Mater. Des. 26, 424-A38. 

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