Air cell size distribution

Eyres, G. The Effect of Foam Air-Cell Size Distribution on the Stability of Marshmallow, NZIFST Annual Meeting, Dunedin, New Zealand, 2001. 

Heenan, S. The Effect of Processing Parameters on Marshmallow Air Cell Size Distribution, Shelf Life Stability and Quality, Honours thesis. University of Otago, New Zealand, 2004. 

Air content, air cell size, size distribution, shape... 

The Carman-Kozeny equation relates the drop in pressure through a bed to the specific surface of the material and can therefore be used as a means of calculating S from measurements of the drop in pressure. This method is strictly only suitable for beds of uniformly packed particles and it is not a suitable method for measuring the size distribution of particles in the subsieve range. A convenient form of apparatus developed by Lea and Nurse 22 1 is shown diagrammatically in Figure 4.4. In this apparatus, air or another suitable gas flows through the bed contained in a cell (25 mm diameter, 87 mm deep), and the pressure drop is obtained from hi and the gas flowrate from h2. 

Experiments were conducted varying the residence time, air flowrate, and oil concentration over the same ranges used to study overall system performance. The oil concentrations and drop-size distributions were measured at the entrance and exit of each stage. Table 2 shows typical results. Most of the drop removal for the large drops and production of the small drops occurred in the first stage. The third notation cell had the lowest rates of drop production and aggregation and the largest drops which were least influenced by these effects. Thus, this portion of the data was analyzed to determine the order of the kinetic process for drop removal by air bubbles. A typical plot of the oil removal rate vs. the outlet oil concentration is shown in Fig. 4 the oil removal process is first-order with respect to the concentration of oil drops. 

Analysis of Fractions. Surface areas and pore size distributions for both coked and regenerated catalyst fractions were determined by low temperature (Digisorb) N2 adsorption isotherms. Relative zeolite (micropore volume) and matrix (external surface area) contributions to the BET surface area were determined by t-plot analyses (3). Carbon and hydrogen on catalyst were determined using a Perkin Elmer 240 C instrument. Unit cell size and crystallinity for the molecular zeolite component were determined for coked and for regenerated catalyst fractions by x-ray diffraction. Elemental compositions for Ni, Fe, and V on each fraction were determined by ICP. Regeneration of coked catalyst fractions was accomplished in an air muffle furnace heated to 538°C at 2.8°C/min and held at that temperature for 6 hr. 

Wilson and co-workers have measured platinum catalyst ripening in PEFC cathodes of ultra-low platinum loading which operated continuously for 25(X)h at a cell voltage of 0.5 V, on pressurized hydrogen and air [46]. Results obtained for the cathode catalyst show that slow catalyst ripening takes place in these PEFC cathodes. The typical degree of ripening for Pt/C catalysts can be summarized as a decrease of platinum surface area from an initial value of 100 m /g to 70 m /g after 1000 h and to 40 m /g after 2500 h. The results of particle size distribution analyses for as-supplied... 

People exposed to PAHs in conjunction with particulates from tobacco smoke, fossil-fuel combustion, coal fly ash, and asbestos fibers are at increased risk of developing toxic effects, primarily cancer. Even people not susceptible to the toxic effects of PAHs may become affected when exposure occurs in conjunction with exposure to particulates (NRC 1983). This enhanced effect results from the adsorption of PAHs onto the particulates. They are vacuolized into cells, and distributed differently in tissues depending on the size and type of particulate matter. This increased PAH uptake may result in more efficient induction of AHH activity at low PAH concentrations. This activity also increases the dose to the gastrointestinal tract as a result of mucocilliary clearance (NRC 1983). This synergistic action between PAHs and particulate matter in air pollution has been associated with the occurrence of stomach cancer in humans (Fraumeni 1975). 

Gorain BK, Franzidis JP, Manlapig EV. (1995a) Studies on impeller type, impeller speed and air flow rate in an industrial flotation cell. Part 1. Effect on bubble-size distribution. Miner. 

Prior to the measurement, the sample is introduced into a sample cell that allows for degassing under vacuum. Usually the same port also provides the coimections to the low pressure system of the mercury porosimeter, where air pressure is applied onto the pool of mercury to force it into the sample in contrast, the high pressure port uses a hydraulic system to provide pressure up to 400 or even 600 MPa. The amount of mercury vanishing from the mercury reservoir, AVmercury. is recorded together with the net applied pressure and converted into a pore size distribution. 

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