Oxidation profiles

Tensile stresses. In glassy, amorphous polymers and semicrystalline polymers, the effect of tensile stresses on diffusion and solubility is complex  

within the elastic region, the sorption of low molecular compounds increases with stress as a consequence of an increase in the free volume fraction  

In the plastic region the sorption of low molecular compounds markedly decreases with an increase of stress, because the density of the amorphous component rises in this case. 

The presence of cracks, pinholes and voids leads to changes of the 

Oxidation profiles are symmetrical with respect to the centre of the sample stack however, photoirradiation from one side of a film makes them unsym-metrical. At the beginning of the reaction the concentration of oxidation products (in a low density polyethylene) is higher in the bulk of the film than on the upper surface layer. With increase in irradiation time the situation is reversed, with an increase of oxidation product concentration on the surface [774]. 

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Wise, J., K.T. Gillen, and R.L. Clough, Quantitative model for the time development of diffusion-limited oxidation profiles. Polymer, 38(8), 1929-1944, 1997. 

In agreement with such an electronic distribution, the cyclic voltammogram of ferrocene displays an oxidation profile (peak A) which is accompanied in the reverse scan by a directly associated reduction process (peak B), Figure 4. 

Interestingly, the vertical distribution of photochemical oxidant may not be such that it falls off rapidly at the inversion layer. In fact, in a classic series of experiments, Edinger and co-workers (1972, 1973) showed that oxidant concentrations in the Los Angeles air basin could be higher within the inversion layer than at ground level. Thus, Fig. 2.19, for example, shows one temperature and oxidant profile for June 20, 1970, over Santa Monica, California, a city adjacent to the Pacific Ocean. Several layers of oxidant (mainly O-,) exist... 

FIGURE 2.19 Temperature and oxidant profiles at 1 28 p.m. over Santa Monica, California, on June 20, 1970 (from Edinger, 1973). 

Fig. 17.5. Comparison between oxidation profiles and compressive strain profiles for a series of four retrieved and one unused UHMWPE cups (details in the inset of...

In 1954, Jeanes et al.5 reported the formation of glucan(s) by 96 strains of bacteria that were primarily Leuconostoc strains. (There is a question here as to whether they are strains or species, particularly with regard to the formation of different kinds of polysaccharides. The classification of the time was to place them into one species, mesenteroides, that had several different strains. This classification stands today.) The polysaccharides were characterized by various properties such as optical rotation, viscosity, periodate oxidation profile, and physical appearance after alcohol precipitation. The latter were observed to have different appearances, which were described by Jeanes et al.5 in various qualitative terms such as pasty, fluid, stringy, tough, long, short, flocculent, and so on. These differences in appearance provided an early suggestion of differences in structure (see Table I). Both water-soluble and water-insoluble polysaccharides were formed, and some strains seemed to form more than one kind of polysaccharide, as judged by their water solubility and by differences in the amount of alcohol needed to precipitate them. 

Figure 6. Typical shape of normalized oxidation profiles into thick PE samples (typically few mm thick). Determination of the thickness of oxidized layer using...

Figure 6.7 Dissolved oxygen (line), nitrite (gray squares) and nitrous oxide (profiles black circles) through the ODZ in the Arabian sea (redrawn from Devol et al., 2007).

Figure 1.15 shows the temperature programmed oxidation profile for a coked Pt/alumina catalyst. The volume of oxygen consumed is used to determine the quantity of carbon initially... 

Figure M5 Temperature programmed oxidation profile for a coked Pt/alumina catalyst.

Dietary MUFA have been found to have several positive effects that include, in addition to lowering human LDL-cholesterol plasma levels, positive effects on lipoprotein oxidation, coagulation, and fibrinolysis (29). Low-fat, monounsaturate-rich diets reduce the susceptibility of low-density lipoproteins to peroxidation ex vivo (30). In hypercholesterolemic subjects, diets containing MUFA resulted in favorable alterations in the fatty acid composition and oxidative profile of LDL in hypercholesterolemic subjects that were characterized as an increase in lipid peroxide lag time and a decrease in lipid peroxide formation (30). In animal studies. 

Hazardous Substance Data Bank, Online database produced by the National Library of Medicine, 1,2-Propylene Oxide Profile last updated, (October 10, 2001). 

Laboratory studies of FT-IR emission (George et al, 1995, Celina et al, 1997) have demonstrated that it may provide real-time oxidation profiles. Figure 3.22 shows successive emission spectm from a single particle of polypropylene at 150°C in the presence of oxygen. 

Figure 11. Oxidation profile perpendicular to the surface in a Cr35Re alloy exposed 4 hours to air at 1600°C.

Soot oxidation profiles as obtained fi r K2M0O4 in tight contact and loose contact are shown in figure 1. The maximum of the exothomic heat effect is located at 685 K for the ball milled sample ( tight contact ) and 790 K for the spatula mixture ( loose contact ). Apparently the milling procure lowers the catalytic soot oxidation temperature by approximately 100 K, and is essential for a high soot oxidation activity. Non-catalytic soot oxidation occurs at 875 K. Neeft et aL [14]... 

In the program conducted for the National Paint, Varnish and Lacquer Association, 45 solvents were examined under the following conditions 4 ppm organic, 2 ppm nitric oxide. Profiles were obtained for the solvents, and reactivity measurements were obtained from the profiles. 

Figure 8.31. (a) XPS elemental profile showing the normalized, relative peak area percentage for fracture surfaces of alloy 1 versus distance, and (b) the normalized oxidation profile showing the oxide formation for Cr and Ni on fracture surfaces of alloy 1 versus distance [35, 36]. 

The time courses of oxidation of EPAEE included in CDs are illustrated in Eigure 1.22 at 50°C, together with the oxidation profile of liquid EPAEE (Yoshii... 

Figure 2. Oxidation profile of C6 alcohols by Candida boidinii SAOSl.

Figure 3 shows that the oxidation profile of the C6 alcohols mixture composed of equal volumes of C6 alcohols. 

Figure 3. Oxidation profile of C-6 alcohols mixture by Candida boidinii SA051.

Figure 4. Oxidation profile of natural C-6 alcohols fraction.

Earnest (128) studied the oxidative profiles of several American and Australian oil shales using TG-DTG. For American and Canadian oil sands. Rosenvold et al. (129) obtained TG and DSC curves of bitumen extracts. The extracts were heated in an inert atmosphere, yielding curves showing that thermal decomposition takes place in two distinct stages. The first stage reaches a maximum at about 350°C, whereas the second shows a rate maximum at 475 C. 

Figure 6 compares the experimentally measured metabolite profiles resulting from the oxidation of a pulse of [ C]-indene by steady state chemostat cells with the kinetic profiles predicted by Eqs. (7)-(12) using flux values independently determined for the same steady state. The excellent agreement between the actual tracer data and the predicted oxidation profiles provides an additional validation of the fluxes calculated for the KYI network. 

Figure 6(b) represents the same oxidation profiles in terms of TOC versus the number of coulombs passed rather than the time elapsed. Using the same electrocatalytic electrodes in each experimental run,... 

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