Volumetric filling factor

The volumetric filling factor of the pore space by water is defined as the liquid water saturation, Sr. It depends on the PSD and wettability of pores. Moreover, it varies with environmental conditions and the current density of fuel cell operation. The amount of liquid water arriving in the CCL is roughly proportional to/o> due to... 

Cell size is a factor controlling not only the volumetric weight of a foam but also such an important morphological parameter as gas-filling (see Sect. 3.2). As follows from Fig. 21, when the cell size decreases (i.e. the number N of cells per millimeter increases, the gas-filling of polyurethane foam samples (2.5 cm thick) also decreases since the number of the closed cells increases. This has been confirmed by air stream resistance tests at a pressure drop of 0.25 mm HjO... 

The aforementioned scale-up procedure was used to design a series of jet-spouted bed dryers based on experiments performed on a 0.5 m unit. Field trials on a 1.5-m dryer filled with 30 kg of Teflon cubes 4 mm in equivalent diameter have shown that the volumetric evaporation ratio varied from 55.4 kg/(m%) to 120.6 kg/(m h) against 100 kg/(m h) taken for design calculations. Also, the heat utilization factor from 0.192 to 0.335 corresponded well to the assumed value of 0.25 (Strumillo et al., 1980). 

On the basis of the above observation, Schultz and Asunmaa developed the following transport mechanism. They made an assumption that the low-density and the noncrystalUnc region of the polymer that fills the space between the circular cells is incorporated into the unit cell as its part. Those spaces (between the unit cells) were therefore assumed to be vacant. In reverse osmosis operation these vacant spaces are filled only with water, and this water is assumed to be more ordered than the ordinary water under strong influence from the polymeric material. This water flows by the viscous flow mechanism through channels that arc formed by connecting the vacant spaces. Suppose r is the effective radius of this pore (m), np is the number of the pore in a unit area (1/m ), p is the pressure drop across the membrane (Pa), 17 is the water viscosity (Pa s), L is the effective layer thickness (m), and r is the tortuosity factor (-), the volumetric... 

Mold filling is considered with various factors of part and mold designs. Material selection and process setup have to be considered to ensure that the mold can be filled volumetrically. 

Under water-saturated conditions, solute diffusion in natural porous media is hindered by the tortuous nature of the pores and reduced cross-sectional area available for diffusion both factors are influenced by the pore size distribution within the medium. If the pores are larger than the mean free path of the molecules in solution ( 1 nm for organic chemical contaminants in water), the molecular diffusivity applies and Knudsen diffusion is negligible (Grathwohl, 1998). Lerman (1979) also consider these factors along with laboratory measurements for water-filled sediments, natural clays, silty-clay soil and sedimentary rocks using sodium chloride, trichloroethylene and iodine. Generally, tortuosity and pore size distribution are difficult to assess, so overall volumetric porosity si (m m ), which can be readily determined from relatively simple measurements, is used to assess the porous media effects on the diffusive process. Therefore, the effective diffusion coefficient is related to the aqueous diffusivity, Daq (m s ) and an empirical function of s alone ... 

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