Moisture holding capacity

Suspension Polymers. Methacrylate suspension polymers are characterized by thek composition and particle-size distribution. Screen analysis is the most common method for determining particle size. Melt-flow characteristics under various conditions of heat and pressure are important for polymers intended for extmsion or injection molding appHcations. Suspension polymers prepared as ion-exchange resins are characterized by thek ion-exchange capacity, density (apparent and wet), solvent sweUing, moisture holding capacity, porosity, and salt-spHtting characteristics (105). 

Moisture Holding Capacity. The bed or equihbrium moisture is the amount of moisture retained after equihbration at 96—97% rh at 30°C (D1412) (18). Total moisture is determined by air drying, cmshing to smaller particle sizes and heating at 107°C to constant weight (D3302). 

Recent work has suggested that the coals of the Illinois Basin were never buried deeper than about 1500 m. (44), compared with an estimated 3000 m. or more for the coals of western Pennsylvania in the Eastern province. Presumably as a consequence, the coals of the Interior province tend to show low values of vitrinite reflectance and high values of moisture-holding capacity relative to coals of other areas of apparently similar rank (45). 

The technology is limited by the selection of the proper microorganisms. Typically, process bacteria work best at temperatures above 40°F, at a pH range between 4 and 9, and a moisture holding capacity of the soil above 20%. 

Given that extruders of various designs, types and geometries are available in the marketplace, let us examine some aspects that drive selection of the appropriate extruder for a product. The key factors relevant in selecting the extruders are formulation factors (selection of excipients, thermal stability, plasticity, aqueous solubility, and moisture holding capacity) and equipment factors (batch versus continuous operation and scalability of the extruder). 

Total moisture of coal Ultimate analysis of coal Ultimate analysis of coke Chlorine in coal and coke Phosphorus in coal and coke Arsenic in coal and coke Analysis of coal ash and coke ash Determination of moisture-holding capacity of hard coal General introduction and methods for reporting results Determination of total moisture of coke Proximate analysis, determination of moisture content of the general analysis test sample... 

ISO 1018. Determination of the Moisture Holding Capacity of Hard Coal. 

Moisture-Holding Capacity—King s experiments, described earlier, indicate that no part of a moist-sand column is in complete equilibrium, even when permitted to drain for many months. However, if a small quantity of soil is saturated with moisture and allowed to drain (without evaporation), a certain degree of equilibrium will be reached. The moisture remaining in the soil, expressed as a percentage of the dry weight of the soil, is called the moisture-holding capacity" Theoretically, as Alway and Clarke (1916) point out, actual equilibrium is not obtainable until the moisture-content of the soil can be shown equal to that of the same soil in actual contact with the water. 

HilgarcTs technique (1906) for the determination of moisture-holding capacity is as follows A layer of soil 1 cm thick is placed in a screen-bottom cup and saturated with water by capillarity. The sample is then drained by placing it in a saturated atmosphere for 24 hrs, after which the moisture is determined in the usual way. 

Moisture-holding capacity = (moisture-equivalent X 1.57) + 21 = (hygroscopic coefficient X 4.26) + 21 = 0.03 percent sand + 0.35 percent silt + 1.65 percent clay + 21 Eq (14-7)... 

Hygroscopic coefficient = moisture-equivalent X 0.37 =. (moisture-holding capacity — 21) X 0.234 = 0.007 percent sand + 0.082 percent silt + 0.39 percent clay Eq (14-8)... 

It is simple to calculate the moisture-holding capacity for spheres in closest packing, since we know the voids amount to approximately 26 percent. If we take the gravity of the spheres to be 2.4, and assume the voids to be completely filled with water,, the moisture-holding capacity Mei ... 

Keen s own studies on hygroscopic moisture offer some useful extensions. If we assume that total moisture is taken at the moisture-holding capacity MCi we have... 

It is important to realize that the bed moisture content of soft brown coals is significantly higher than the equilibrium moisture holding capacity, a parameter which is used to characterize higher rank coals. This is illustrated in Table 1 for a range of Victorian brown coals. 

In terms of moisture the economic value of high-rank coals is best indicated by the moisture holding capacity because it reflects the condition of the coal for utilization. In the case of Victorian brown coal, the bed moisture content is the critical value since the coal is used directly from the open cut. 

TABLE 1. BED MOISTURE AND MOISTURE HOLDING CAPACITY FOR SELECTED VICTORIAN COALS... 

British Standard BS 1016 Part 21 1981, Analysis and testing of coal and coke. Determination of moisture-holding capacity of coal. 

Table 23-2 relates cross-linking, porosity, and moisture holding capacity. 

Cross-linking Porosity Moisture Holding Capacity %... 

MOISTURE-HOLDING CAPACITIES AND SPECIFIC GRAVITIES OF SEVERAL TYPES OF PEAT (from FEUSTEL and BYERS, 1930)... 

Type of peat Location Depth (inches) in dry peat (%) Volume wt. (g) Maximum moisture-holding capacity %) Moisture equivalent (%) Air-dry moisture (%) Apparent specific gravity Absolute Maxispecific mum ... 

Feustel and Byers determined the moisture-holding capacities and wilting percentages of three peats and two soils, and of mixtures of these. A portion of these data is shown in Table 30.1. From these data the available moisture has been calculated and expressed as percentage of the moisture-holding capacities of the various materials and mixtures. 

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