Humidity content

FIG. 25-17 Schematic flowsheet illustrating the individual elements of an open, single-layer hiofilter system. Particulate filtration and/or temperature adjustment is often combined with the equipment to adjust gas humidity content. 

In order to assess the dependence of the output signal on changes in the humidity content of the sample gas, an additional series of measurements was carried out. The hotplate temperature was set to 275 °C, and CO measurements were recorded at three different humidity levels (10, 20 and 40% r.h.) The humidifier temperature was set to 23 °C, and the chip temperature was 30 °C. As can be seen in Fig. 5.14, the sensor response increases with increasing humidity. The large sensor response difference between 10% and 20% r.h. shows that this effect is more pronounced at low humid-... 

Triggered by planetary pressure gradients, large-scale transfers of air masses occur which differ in terms of their energy or humidity content. When they collide, this creates frontal zones as the warmer, hghter (or even more humid) air rises above the colder air. This process can result in condensation and longer-lasting precipitation (Fig. 2b). 

Voltammetric determination using the Karl Fischer approach can be carried out using either direct titration or back titration. In the direct titration procedure, the equivalence point is obtained by adding the necessary amount of Karl Fischer reagent. When back titration is used, an excess of reagent is added and the excess after equivalence is reached is determined with an anhydrous solvent whose humidity content is known. 

The different properties of water with different bonds to organic molecules can be demonstrated also with dye diffusion measurements in polyamide fibres148,149. Acid dyes show a remarkable decrease of diffusion velocity in 6-polyamide if the humidity content is reduced. It is necessary to heat polyamide fibres in air contact at 150 °C to get similar diffusion velocities of acid dyes at 60 °C under water saturation. The diffusion coefficient of water itself in 6-polyamide depends strongly on the water content148,149 (Fig. 29). This was determined by a quartz spring balance method. 

Fig. 10.—Effect of pressure on the conductivity of starch of various humidity contents (from Ref. 66).

Fig. 13.—Effect of humidity content on dielectric constant, e (from Ref. 67).

Smoke energy content is affected in turn by several parameters smoke temperature and excess of air, condensation index, air humidity content, air and fuel inlet temperatures and unburned hydrocarbons. Each of these contributions to chimney boiler losses is shown in Figure 34.3. 

Others parameters affecting losses at the chimney are the air humidity content, the air and fuel inlet temperatures, and the unburned hydrocarbons. Vapor content of air influences chimney losses in two ways it takes away part of the heat given by the fuel and modifies the dew point temperature as already seen. Not only does the combustion reaction produce water vapor as one of the outputs, but also a—relatively small—fraction of the water vapor... 

If liquid hydrogen is released in ambient air with a high humidity content, the flammable fiaction of the gas cloud is generally enclosed in the visible cloud, while under conditions of a dry atmosphere, flammable fractions could also exist outside the visible cloud. These observations show that the visible cloud is not a precise indicator for the flairunable zone of the gas cloud [130]. The 4 % lower limit coincides with the perimeter of the visible cloud at temperatures of about 270 - 300 K and humidities of about 50 - 57 %, but with strong fluctuations in the concentration which affect the capability of flame maintenance. 

Thermal desorption Method development was done with sample amounts of 50-100 mg. The use of larger sample amounts can overload the injection system and the capillary column. Drying of the sample prior to thermal extraction is necessary because problems with humidity content of the soil and other matrix effects can happen. Variations of the parameters desorption time and desorption temperature lead to an optimized method. The calibration curve in the range from 1-100 ppm shows a good linearity with relative standard deviations of about 5-7% (Fig. 11). These values are higher compared to liquid extraction due to the inhomogeneity of the soil samples. An additional homogenization of the samples reduced the relative standard deviation to about 2-3%. 

Of particular relevance is the study of dye photodegradation, either on wet or dry cellulose, due to the importance of this effect in the textile industry [89]. Today we know that an increase of the humidity content in the fiber promotes a decrease in the lightfasmess of many dyes. This effect exists both for cotton and other polymers where the dye may be adsorbed or covalently bound [89-91]. It also occurs for wool, although to a smaller extent, since in this substrate the mechanism is essentially reductive, while in cellulose it is an oxidative one [89]. 

Climate is most stressful in cold weather when there are low ambient temperatures, high wind speeds, and absence of solar radiation. The humidity content is very low in freezing cold and therefore not an important factor. However, wet cold at ambient temperatures just above the freezing point can form a considerable cold stressor since water takes away the body heat more quickly through convection. Body cooling occurs more rapidly when people are wet (Thompson and Hayward, 1996). Therefore, hypothermia is more apparent in wet cold than in dry cold. 

Bliss s correlation [91] also takes air humidity content into account... 

Figure 7.17 Conductivity of proton membranes as function of the humidity content. (Prom reference 124, reproduced by permission of the Electrochemical Society, Inc.)...

Fig. 7. Rolling resistance of a glass cylinder on polyurethane for various room humidity content (from ref. 24). ...

The construction of the overall cell is realized by a simple lamination (combining heat and pressure) of the three components in the correct order. Due to the sensitivity to moisture of lithium and of lithium compounds, the entire operation is run in controlled-atmosphere dry boxes or, for larger production, in dry rooms where the humidity content is maintained within > 1 % relative humidity. 

EO fed to the autoclave was 21.546 kg together with the same quantity of PO over a time of 1.4 h and humidity content of -0.2% by weight. The total pressure was 1.7 atm and temperature was kept constant at 107°C. The product obtained was then neutralized with aqueous sulfuric acid and volatile residue was removed by vacuum distillation at 180°C at 2 mm Hg of pressure. The average molecular weight of the obtained product is 467 g/mol, as evaluated by means of the hydroxyl end group method [22-25]. 

Core material Storage conditions cleanliness humidity content, drying... 

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