Effects of temperature, humidity and

Researchers have examined the creep and creep recovery of textile fibers extensively (13-21). For example, Hunt and Darlington (16, 17) studied the effects of temperature, humidity, and previous thermal history on the creep properties of Nylon 6,6. They were able to explain the shift in creep curves with changes in temperature and humidity. Lead-erman (19) studied the time dependence of creep at different temperatures and humidities. Shifts in creep curves due to changes in temperature and humidity were explained with simple equations and convenient shift factors. Morton and Hearle (21) also examined the dependence of fiber creep on temperature and humidity. Meredith (20) studied many mechanical properties, including creep of several generic fiber types. Phenomenological theory of linear viscoelasticity of semicrystalline polymers has been tested with creep measurements performed on textile fibers (18). From these works one can readily appreciate that creep behavior is affected by many factors on both practical and theoretical levels. 

Sarisuta N. Parrott EL. Effects of temperature, humidity, and aging on the disintegration and dissolution of acetaminophen tablets. Drug E>ev Ind Pharm 1988 14(13) 1877-81. 

HMSO (1969) The natural durability classification of timber. HMSO, London Hoadley RB (1979) Effect of temperature, humidity and moisture content on solid wood products and end use. In Proceedings of wood moisture content temperature and humidity relationships symposium, Blacksburg. USDA, Forest Service, Forest Products Laboratory, North Central Experiment Station, Raleigh, North Carolina, 92-6 Flofbauer H, Veronik G, Fleck T, Rauch R, Mackinger H and Fercher E (1997) The FICFB gasification process. In Bridgewater AV and Boocock, DGB (eds), Developments in thermochemical biomass conversion. Blackie Academic and Professional, London, Vol. 2 1016-25... 

TEMPERATURE, EFFECTIVE - An arbitrary index which combines into a single value the effect of temperature, humidity, and air movement on the sensation of warmth or cold felt by the human body. The numerical value is that of the temperature of still, saturated air which would induce an identical sensation. 

A more complex and well-known climatic index is the Wet Bulb Globe Temperature (WBGT), used as a heat stress indicator. The WBGT is a composite temperature used to estimate the effect of temperature, humidity, and solar radiation on humans. It is used by industrial hygienists, athletes, and the military to determine appropriate exposure levels to high temperatures. It is derived from the following formula ... 

The flame-retardant grades generally display increased values of dissipation factor over the frequency range. Additional electrical property data illustrating the effects of temperature, humidity, and frequency are available for many systems described in pars. 3-8 through 3-24. 

The purpose of stability testing is to assess the effects of temperature, humidity, light, and other environmental factors on the quality of a drug substance or product. The data produced are used to establish storage conditions, retest periods, shelf loss, and to justify overages included in products for stability reasons. The most useful equation relating temperature and reaction rate is the Arrhenius equation. This equation (27) may be integrated and rewritten as Eqs. (31) and (32). 

The effect of relative humidity and temperature on the physical and structural properties of the 1 1 isopropanol solvatomorph of warfarin has been studied [58], Below the critical relative humidity of 60-68% the solid is not hygroscopic, but becomes deliquescent at higher values of relative humidity without exchange of water for isopropanol. Storage of the solvate-morph at elevated temperatures causes formation of an amorphous solid owing to loss of isopropanol, which may proceed through an intermediate crystalline phase. 

Exposure can be carried out in conditions where UV light and rain are excluded, which is essentially measuring the effects of temperature, oxygen and humidity. This is relevant... 

Relative humidity and temperature are two variables which have influence on the chromatographic behavior of the solutes [2] but which can not always be set at desired levels. The relative humidity is expected to have a large influence, while temperature has a small influence. In reference [2] it is stated that a temperature change of 5 degrees seldom exceeds reproducibility limits of the standard working techniques. It is most feasible to discuss the effect of variation in relative humidity and temperature in terms of activity. Therefore in the following paragraphs first the concept of activity will be introduced. Then the concept will be applied in a short examination of the effect of relative humidity and temperature on the retention. 

Some general conclusion from these studies are (1) Cu/PI TFML structures have excellent thermal and mechanical stability under extremes of temperature, humidity, and radiation (2) the adhesion of polyimide is highly dependent on interface chemistry and surface preparation (3) PI rapidly absorbs and desorbs water, which has an appreciable effect on its dielectric properties and thus the electrical charactersitics of TFML interconnections the electrical design tolerances must accommodate these variations or the package must be hermetically sealed (4) properly baked and sealed TFML packages can maintain MIL-STD internal moisture levels of less than 5000 ppm at 100°C. 

Bubble nucleation is affected by a number of conditions. Physically, the effects of temperature, pressure, and in some cases humidity are fairly obvious. Other important parameters are surface smoothness of the substrate, surface characteristics of filler particles, presence and concentration of certain surfactants or nucleators, size and amount of second-phase liquid droplets, and the rate of gas generation. 

Effect of Relative Humidity and Sorption History. An indirect method for estimating wood moisture content is to measure its equilibrium relative vapor pressure h. This is related to wood moisture content by a sorption isotherm. The percent relative humidity (H) or relative vapor pressure (h) (H = 100 h) is the most important factor in determining the EMC for wood. A curve showing EMC as a function of percent relative humidity or relative vapor pressure at constant temperature is called a moisture sorption isotherm. 

The effects of relative humidity and temperature on the moisture sorption and stability of sodium bicarbonate powder have been investigated. Sodium bicarbonate powder is stable below 76% relative humidity at 25°C and below 48% relative humidity at 40°C. At 54% relative humidity, the degree of pyrolytic decarboxylation of sodium bicarbonate should not exceed 4.5% in order to avoid detrimental effects on stability. ... 

Rill Nanji, A.A., Poon, R. and Hinberg, I. (1988). Effect of extreme humidity and temperature on Seralyzer and Reflotron test strips. Clin. Chem. 34, 178. 

Covers the determination of the ability of rubber to withstand the environmental effects of high humidity and temperature. The effects are determined by noting the change in tensile strength after exposure over distilled water. 

The most dismptive element of providing care for chemical casualties when wearing PPE is caused by heat stress and subsequent dehydration of the responder. To decrease heat stress, published tables provide work-rest cycles based on temperature being measured by the Wet Bulb Globe Temperamre Index (FM 3-11.4, June 2004). Careful adherence to these tables will decrease heat-related casualties among responders. This index considers the effects of temperature, humidity, radiant energy, and wind. It produces a temperature based on integration of the effects of the above four factors (Stafford County Public Schools, unknown year). 

In this present case, we will consider the nature of modes of sorption and permeation of water in polymers in terms of degradation induced changes in polymer composition. These changes can accentuate the effects of temperature-humidity cycling on water sorption and diffusion to cause major changes in properties with progressive degradation. 

Tdble IV. Effect of relative humidity and temperature on decay and weight loss of carrots, parsnips and rutabagas... 

Table VI. Effect of relative humidity and temperature stored in air.

COMFORT ZONE - (Average) the range of effective temperatures over which the majority (50 percent or more) of adults feels comfortable (extreme) the range of effective temperatures over which one or more adults feel comfortable. An area on the psychometric chart which shows conditions of temperature, humidity and sometimes air movement in which most people are comfortable. 

Abstract We review recent progress in wide bandgap thin-film and nanorod sensors made from GaN or ZnO and related materials for applications in the detection of gases such as oxygen, carbon dioxide and hydrogen. Practical aspects are covered, such as the use of differential sensor pairs to eliminate the effects of temperature variations and of the effect of humidity on the detection sensitivity. 

An operating fuel cell has varying local conditions of temperature, humidity, and power generation (and thereby heat generation) across the active area of the fuel cell in three-dimensions. Nevertheless, no models have yet been published to incorporate the effect of hygro-thermal stresses into actual fuel cell models to study the effect of these conditions on the stresses developed in the membrane. In addition, the transport phenomena in a fuel cell are inherently three-dimensional, but no models have yet been published to address the hygro-thermal stresses in PEM with the three-dimensional effect. 

Setpoint drift can be defined as a change in the input-output relationship of an instrument over a period of time. Setpoint drift can occur as a result of a number of factors including component failure, instrumentation error and environmental conditions. Setpoint drift primarily affects analog instrumentation rather than digital instrumentation (which is less sensitive to the environmental effects of temperature, humidity, etc.). Safety-related instrumentation and controls systems use setpoints as a means of determining when to initiate a safety function. Should an unplanned change in the setpoint of a safety-related component occur (i.e., setpoint drift) the actual value of the measured parameter at which a particular action is specified to occur will be altered. This phenomenon can result in the delay in the initiation of a safety function. 

Drawing on empirical data, meteorologists not only analyze the effects of temperature, pressure, and humidity in the area of the atmosphere they are studying but also apply their findings to ever-widening areas of the globe. From their analyses, they are able to predict the weather—for example, the... 

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