Effects of physical state

Effect of Physical State on the Stability of Dry Powder Formulations... 

To gain insight into the effect of physical state and/or molecular organization on lipid oxidation, a variety of model systems have been used. These include dispersions, liposomes or vesicles (37,38), monolayers adsorbed on silica (39,40,41), and red blood cell ghosts (42). In most of these studies, oxidation was conducted at relatively low temperatures, i.e., 20 - 40°C. Very little information is available on the effects of physical state on high temperature oxidative reactions or interactions of lipids. 

By analogy with the studies of Johansen and Vallee, it could be that the positive charge influencing the ionization behavior of nitrotyrosine-248 in nitrocarboxypeptidase is the active site zinc ion. To test this possibility, the effect of physical state on the nitrotyrosyl pK was examined. Titration of nitrocarboxypeptidase crystals from pH 6.5 to 9.5 increases absorbance at 428 nm and decreases it at 381 nm with an isosbestic point at 381 nm. However, in contrast to the enzyme in solution, the midpoint of this titration occurs at pH 8.2 rather than at pH 6.3 (Figure 8). This dramatic shift in titration behavior, brought about solely by a change in physical state of this enzyme, indicates that in nitrocarboxypeptidase as in arsanilazocarboxypeptidase, the conformations of tyrosine-248 in solution and in the crystalline state are different. 

Remember, these trends hold only for substances in the same physical state. Gaseous methane (CH4) has a greater entropy than liquid ethanol (C2H5OH), even though ethanol molecules are more complex. When gases are compared with liquids, the effect of physical state usually dominates that of molecular complexity. 

Figure 11. Effect of physical state of the precursor on the degree of CRN sialon formation from potassium geopolymer/graphite composite. Key a = p-sialon, b = amorphous phases, c = a-alumina,...

The effect of physical aging on the crystallization state and water vapor sorption behavior of amorphous non-solvated trehalose was studied [91]. It was found that annealing the amorphous substance at temperatures below the glass transition temperature caused nucleation in the sample that served to decrease the onset temperature of crystallization upon subsequent heating. Physical aging caused a decrease in the rate and extent of water vapor adsorption at low relative humidities, but water sorption could serve to remove the effects of physical aging due to a volume expansion that took place in conjunction with the adsorption process. 

The effect of physical structure and state of aggregation on the sensitivity of expls) (Engl translation OTIA 5377, AEC-tr-3781)... 

Whitson, C.H. Effect of Physical Properties Estimation on Equation-of-State Predictions, paper SPE 11200 presented at the 57th Annual Fall Technical Conference and Exhibition, New Orleans, Sept. 26-29, 1982,... 

This brought a bout a keen interest in other methods of intensification in processing. Lately, the directed effect of physical (mechanical) fields on molten polymers has become one such area. These effects, as demonstrated in many works published in the 1970s and in the 1980s, (see for examples [6-9]) result in altered parameters of micro- and macrostress of the system. Molding under conditions of directed physical fields, in particular, in the case of mechanical and acoustic vibration effects upon melts, is performed so that an additional stress superimposed on the polymer s main shear flow and the state of material is characterized by combined stress. 

In view of the above I have chosen to emphasize, in this article, three areas which in my opinion merit additional focus (1) unique aspects of high-temperature oxidation (2) interactive effects (3) influence of physical state. 

My observation about the involuntary patient requires a further comment. Psychiatrists not only define what they consider unwanted behaviors as diseases, for example, self-abuse and homosexuality in the past, drug abuse and homophobia today they also define what they consider improved behaviors—produced, for example, by lobotomy, electroshock, or psychotropic drugs—as the results of treatments. In 1948 Paul Hoch (1902-1964), professor of psychiatry at Columbia University and the Commissioner of Mental Hygiene for New York State, explained the therapeutic effectiveness of physical treatments of mental illnesses as follows This brings us for a moment to a discussion of the brain damage produced by electroshock. Is a certain amount of brain damage not necessary in this type of treatment Frontal lobotomy indicates that improvement takes place by a definite damage of certain parts of... 

It was noted previously that fatty acid solubility in water was not influenced by the physical state of the fatty acid at the experimental temperature. The striking influence of physical state on monoglyceride solubilization suggests that bile acids can only disperse large liquid aggregates when the short-range intramolecular forces have already been disrupted by the combined effect of heat and water. 

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