Moisture, effects

H. J. Hoffman, Moisture Effects on Mechanical Properties of Solid Propellants, CPTR 84-29, CPIA Pubhcations, Johns Hopkins University, Laurel, Md., Feb. 1984. 

Hygroscopic (moisture) effects arise for polymer materials such as some epoxies that absorb moisture chemically after curing and therefore expand. These effects are directly analogous to thermal effects and are characterized by coefficients of moisture expansion and p2 in principal material coordinates in direct analogy to a.( and 02 for coefficients of thermal expansion. All calculations for thermal effects with the a can be replaced by or supplemented with analogous terms for moisture expansion. 

C. E. Browning, G. E. Husman, and J. M. Whitney, Moisture Effects In Epoxy Matrix ComposHos, in Composite Materials Testing and Design (Fourth Conference), J. 

Schleussinger A, B Ohlmeier, I Reiss, S Schulz (1996) Moisture effects on the cleanup of PAH-contaminated soil with dense carbon dioxide. Environ Sci Technol 30 3199-3204. 

Cuesta A, Lopez N, Gutierrez C. 2003. Electrolyte electroreflectance study of carbon monoxide adsorption on polycrystalline silver and gold electrodes. Electrochim Acta 48 2949-2956. Date M, Hamta M. 2001. Moisture effect on CO oxidation over Au/Ti02 catalyst. J Catal 201 221-224. 

S. T. Tzannis and S. J. Prestrelski, Moisture effects on protein-excipient interactions in spray dried powders. Nature of destabilizing effects of sucrose, J. Pharm. Sci, 88(3), 360 (1999). 

T Durig, AR Fassihi. Preformulation study of moisture effect on the physical stability of pyridoxal hydrochloride. Int J Pharm 77 315-319, 1991. 

Chemical parameters (e.g., partition coefficients, decay rates, temperature and moisture effects) are not usually considered as calibration parameters because they can be measured in a laboratory moreover, calibration is usually not possible due to lack of observed data. However, most scientists will agree that extrapolation of laboratory parameter measurements to field conditions is a risky assumption. If observed chemical data are available, refinement of initial chemical parameters through calibration should be considered. Errors in calibration-derived parameter values are often a function of how much calibration was performed or errors in system inputs and/or outputs. In many modeling efforts, conscientious model users will often overrun the calibration budget because of the natural tendency to continue to make calibration runs in an effort to minimize discrepancies between simulated and observed values. Parameter errors associated with calibration are more often a result of missing and/or erroneous data either as system inputs or outputs. 

Soil Moisture Effect The effects of soil moisture content and soil texture and pore size distribution on kerosene conductivity were studied by Gerstl et al. (1994). Figure 12.13B shows the kerosene conductivity in sand, loam, and clay soil columns, as the initial moisture content varies from 0% (oven dried) to field capacity. 

The moisture uptake in the cured samples appears to have no effect on the room temperature tensile properties as demonstrated in Table I. A critical study to be done is to determine the moisture effect on properties at elevated temperatures. 

M. (1992) Moisture effects on visible spectral characteristics of lateritic soils. Soil Sci. 153 129-141... 

Braddock, R. J., and Dugan, L. R., Jr. (1969). Moisture effect on the nitric oxide pigments in freeze-dried beef. Food Technol. 23, 1085-1086. 

Urea in a compatible cream vehicle or ointment base has a softening and moisturizing effect on the stratum corneum. It has the ability to make creams and lotions feel less greasy, and this has been utilized in dermatologic preparations to decrease the oily feel of a preparation that otherwise might feel unpleasant. It is a white crystalline powder with a slight ammonia odor when moist. 

Ahlneck C, Zografi G. The molecular basis of moisture effects on the physical and chemical stability of drugs in the solid state. Int J Pharm 1990 62 87-95. 

The dielectric constant is affected in different ways by a number of different mechanisms. Some of these mechanisms are interdependent and so it is difficult to ascertain their individual dependencies on fluorine incorporation. For instance, the increased hydrophobicity caused by fluorination decreases the ambient dielectric constant by elimination of water from the polymer, while the incorporation of fluorine also affects the intrinsic properties of the polymer irrespective of the moisture effect. Most published dielectric data were measured under ambient conditions and thus the distinction between these effects is lost. 

A vessel whose volume is 235 0 ml, and whose weight evacuated is 13 5217 g + a tare vessel, is filled with an unknown gas at a pressure of 725 torr and a temperature of 19°C It is then closed, wiped with a damp cloth, and hung in the balance case to come to equilibrium with the tare vessel The tare vessel has about the same surface area and is needed to minimize surface moisture effects This second weighing is 13 6109 g + the tare vessel What is the mole weight of the gas7... 

Keywords Polyimide adhesion fluorine contamination aminosilane moisture effects. 

Moisture. No moisture effect has been shown in vertebrates, but in insects it was noted that housefly larvae reared on diets containing 40% moisture had four times more activity for the epoxidation of heptachlor than did larvae reared in a similar medium saturated with water. 

Aloe vera gel is a mucilaginous preparation obtained from the leaves of Aloe vera (syn. Aloe barbadensis) once the sap has been drained away. It is widely used in cosmetic products for its purported emollient and moisturizing effects. It is claimed to have antibacterial, antifungal, and anti-inflammatory properties and has been proposed as a potentially useful agent for radiation and thermal wounds (see Chapter 12). 

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