Relative humidity paper

Control of relative humidity is needed to maintain the strength, pHabiUty, and moisture regain of hygroscopic materials such as textiles and paper. Humidity control may also be required in some appHcations to reduce the effect of static electricity. Temperature and/or relative humidity may also have to be controlled in order to regulate the rate of chemical or biochemical reactions, such as the drying of varnishes, the appHcation of sugar coatings, the preparation of synthetic fibers and other chemical compounds, or the fermentation of yeast. 

Protection capabilities of bags can be maximized by maintaining the moisture content of the paper at 6—8% by weight, relative to a shipping environment of 21°C at 60% in relative humidity. When the moisture content of shipping-sack paper drops below 6%, the sacks become excessively brittle however, if short-term storage under such conditions is unavoidable, an attempt should be made to place them in an environment with adequate relative humidity for 24—48 hours prior to their use. 

Gaseous sterilization Ethylene oxide (EO) Reactive chemical Indicator paper impregnated with a reactive chemical which undergoes a distinct colour change on reaction with EO in the presence of heat and moisture. With some devices rate of colour development varies with temperature and EO concentration Gas concentration, temperature, time (selected devices) NB a minimum relative humidity (rh) is required for device to function... 

No systematic studies of a number of compoimds have yet appeared to discover correlations suggestive of mechanism. This paper presents the fractional conversions and reaction rates measured under reference conditions (50 mg contaminants/m ) in air at 7% relative humidity (1000 mg/m H2O), for 18 compounds including representatives of the important contaminant classes of alcohols, ethers, alkanes, chloroethenes, chloroalkanes, and aromatics. Plots of these conversions and rates vs. hydroxyl radical and chlorine radical rate constants, vs. the reactant coverage (dark conditions), and vs. the product of rate constant times coverage are constructed to discern which of the proposed mechanistic suggestions appear dominant. 

Place emulsion-coated slide in a horizontal position and wipe the back of the dipped slide with a paper towel or a damp sponge and place the slide flat on a drying rack protected from safelight exposure for 1 h at 45-50% relative humidity (RH). The emulsion will gel in approximately 1 h but can be speeded up by placing the slide on a cold metal plate for 15-... 

Figure 4.10 The effect of relative humidity (%) on the stress-strain curve of paper.

The initial adsorption of water by fibres up to a relative humidity of 80% is only around 10 to 15%, but paper makers are concerned... 

Atmospheric corrosion is the most extended type of corrosion in the World. Over the years, several papers have been published in this subject however, most of the research has been made in non-tropical countries and under outdoor conditions. The tropical climate is typical of equatorial and tropical regions and is characterized by permanently high temperatures and relative humidity with considerable precipitation, at least during part of the year. A high corrosion rate of metals is usually reported for this climate. 

In this paper a model is made describing the relation between a response variable (e.g. R , K, zj and the independent variables (mobile phase composition, temperature and relative humidity). When a separation is optimized it is of importance to select the best performing response variables. Best performing, in this case, meaning, giving the most trustworthy predictions. For reasons stated below was used as response variable. The R can be used to calculate Rp k and R values (equation(4)). The value taken for N in this latter calculation was 3000. 

For a Taguchi approach to robustness the solvent composition is varied in the inner array, and the relative humidity and temperature in the outer array. The response is the resolution of noscapine and quinine. The data used in this example is a subset of the data set which is collected for this paper. The inner array consists of seven design points, the outer array of three. The three responses obtained at each setting of the inner array are combined to form a so-called signal-to-noise ratio. For maximization of the responses the following equation is [11] ... 

In chromatographic terms the purpose of this paper is to find a mixture composition which results in a good separation of the solutes, both under standard environmental conditions and for different temperatures and relative humidities. In this section this chromatographic purpose is combined with the Taguchi approach to robustness. This results in mathematical expressions which quantify the separation and the robustness against environmental influences. 

Swelling tests and determination of tensile properties. The procedure for estimating cross-link density from equilibrium swelling data is described in detail in a previous paper (6). The tensile properties of the PU films were carried out at 23°C and 60% relative humidity. The crosshead speed and distance were 10 mm/min and 30 mm, respectively. A more detailed description of the tensile tests is given elsewhere (6). 

ERH may be estimated by measuring the relative humidity of the headspace over a food in a small, sealed container hygrometrically, psychro-metrically or directly by measuring the moisture content of the air by gas chromatography. ERH can be estimated by moisture-related colour changes in paper impregnated with cobalt thiocyanate (Co(SCN)2) and compared to standards of known aw. 

The psychromelric chart provides a quick means for convening from one humidity format to another because dew point, relative humidity, ambient temperature, and wet bulb temperature can he conveniently related to each other on a single sheet of paper. The psychromelric chan has... 

Amdur, E. J. Nelson, D. E. "A Ceramic Relative Humidity Sensor", Paper 38, ibid. 

The Effect of Variations in Relative Humidity on the Accelerated Aging of Paper... 

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