Moisture proportion

Tricalcium phosphate, Ca2(P0 2> is formed under high temperatures and is unstable toward reaction with moisture below 100°C. The high temperature mineral whidockite [64418-26-4] although often described as P-tricalcium phosphate, is not pure. Whidockite contains small amounts of iron and magnesium. Commercial tricalcium phosphate prepared by the reaction of phosphoric acid and a hydrated lime slurry consists of amorphous or poody crystalline basic calcium phosphates close to the hydroxyapatite composition and has a Ca/P ratio of approximately 3 2. Because this mole ratio can vary widely (1.3—2.0), free lime, calcium hydroxide, and dicalcium phosphate may be present in variable proportion. The highly insoluble basic calcium phosphates precipitate as fine particles, mosdy less than a few micrometers in diameter. The surface area of precipitated hydroxyapatite is approximately... 

Because mass flow bins have stable flow patterns that mimic the shape of the bin, permeabihty values can be used to calculate critical, steady-state discharge rates from mass flow hoppers. Permeabihty values can also be used to calculate the time required for fine powders to settle in bins and silos. In general, permeabihty is affected by particle size and shape, ie, permeabihty decreases as particle size decreases and the better the fit between individual particles, the lower the permeabihty moisture content, ie, as moisture content increases, many materials tend to agglomerate which increases permeabihty and temperature, ie, because the permeabihty factor, K, is inversely proportional to the viscosity of the air or gas in the void spaces, heating causes the gas to become more viscous, making the sohd less permeable. 

The quantity of undrainable residual moisture caimot be predicted without the benefit of experimental data. Equation 17 (6) indicates the important parameters where the exponents were determined using limited experimentation. Introducing the approximation that is proportional to 1/d, where s is the specific surface area per weight of solid, the modified equation for undrainable liquid becomes... 

The isomeric mixture is a colodess, mobile Hquid with a sweet, slightly irritating odor resembling that of chloroform. It decomposes slowly on exposure to light, air, and moisture. The mixture is soluble ia most hydrocarbons and only slightly soluble ia water. The cis—trans proportions ia a cmde mixture depend on the production conditions. The isomers have distinct physical and chemical properties and can be separated by fractional distillation. 

Choline dihydrogen citrate (CH2)3N(CH2CH20H)C H202, is prepared by methods similar to those for preparing choline chloride. It has the same pharmacological action as the chloride, but contains a lower proportion of choline. It is not as dehquescent as the chloride, and absorbs moisture from the atmosphere only at relative humidities greater than 56% at 25.5°C. It is mote palatable than the chloride. 

Another aspect to consider in the design of closed-drying systems is the drydown time. The drydown time is the period requited for the system to dry down from its initial water concentration (or partial pressure) to a concentration that approaches equihbrium with the desiccant. During this time, the system is not fljlly protected from the negative effects of the moisture that the desiccant is designed to remove. In such a system, the instantaneous drying rate is proportional to the water content at any time (18). 

Fig. 8. Drying time and rate profiles for leather pasted on glass plates and dried in two temperature stages. Gas velocity = 5 m/s in parallel flow, 71°C in the first stage, 57°C in the second. The falling rate, drying rate is proportional to residual moisture content.

AH = moisture-content correction of air saturated at wet-bulb temperature when barometric pressure differs from standard barometer, gr/lb dry air NOTE To obtain AH reduce value of AH by 1 percent where t — t, = 24 F and correct proportionally when t — is not 24 F h = enthalpy of moist air, Btu/lb dry air... 

Small particles are required, to provide a large surface-area-to-mass ratio and for the solid to remain in suspension. Surface absorption of air (oxygen) by the solid, or tlie evolution of combustible gas or vapour on heating, may be a predisposing factor. The presence of moisture reduces the tendency to ignite it also favours agglomeration to produce larger particles. An increase in the proportion of inert solid in particles tends to reduce combustibility. 

One part by weight of propyl-methyl-carbinyl allyl barbituric acid is added to enough alcohol to facilitate handling, in this case conveniently about six times its weight. To this is added a solution of sodium hydroxide, preferably carbonate-free or substantially so, containing °%38 parts by weight of sodium hydroxide, which is the amount of sodium hydroxide necessary to combine in equal molecular proportions with the propyl-methyl-carbinyl allyl barbituric acid. This solution is filtered clear, and is then evaporated under vacuum until the sodium propyl-methyl-carbinyl allyl barbiturate (alternatively named sodium allyl 1-methyl-butyl barbiturate) separates out in solid form. The salt as thus obtained in solid form contains a varying amount of moisture. 

The temperature of air as indicated by a thermometer when a water-wet wick encloses its bulb. If the surrounding air is not saturated water will evaporate, taking the latent necessary latent heat from the thermometer bulb which then gives a lower reading than a dry bulb in the same air. The depression in wet bulb temperature is proportional to the amount of moisture in the air. 

When two samples of air are brought together the condition of the mixture may be arrived at arithmetically by adding the heat flow of each and dividing by the total mass flow and similarly for the moisture flow. Alternatively, plot the condition of each onto a psychrometric chart. The mixed condition lies on a straight line between the two in a position proportional to the two quantities. 

The amount of moisture that air can hold is inversely proportional to the pressure of the air. As the pressure of the air increases, the amount of moisture that air can hold decreases. The amount of moisture air can hold is also proportional to the temperature of the air. As the temperature of the air decreases, the amount of moisture it can hold decreases. The pressure change of compressed air is larger than the temperature change of the compressed air. This causes the moisture in the air to condense out of the compressed air. The moisture in compressed air systems can cause corrosion, water hammers, and freeze damage. Therefore, it is important to avoid moisture in compressed air systems. Coolers are used to address the problems by moisture in compressed air systems. 

The proposed mechanism includes the production of HCl from the pyro-hydrolysis of the metal chlorides. Similar reactions are likely for bromides and iodides. Fluorides however are relatively stable and would not be expected to hydrolyse. It was considered that this might account for the inability of fluorides to cause cracking. Hydrogen absorption by titanium alloys exposed to chloride salts at elevated temperatures has been detected and found to be proportional to the amount of moisture participating in the reaction. 

The proportion of moisture can also be expressed as the ratio of the vapour pressures, and is then termed relative humidity ... 

This straight-line proportioning holds good to close limits of accuracy. The horizontal divisions of dry bulb temperature are almost evenly spaced, so indicating sensible heat. The vertical intervals of moisture content indicate latent heat. 

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