Impact of particles

Mamane H (2008) Impact of particles on UV disinfection of water and wastewater effluents a review. Rev Chem Eng 24 67-157... 

Piol, M.N., L6pez, A.G., Mino, L.A., Afonso, M.D.S., and Guerrero, N.R.V., The impact of particle-bound cadmium on bioavailability and bioaccumulation A pragmatic approach, Environ Sci Technol,... 

CA 61, 13118(1964) [Transmission of detonation for exchanged ions expls (EIE) is not as good under confinement as it is in open air, whereas classical safety expls transmit deton to a distance which is proportional to the degree of confinement. An EIE is relatively insensitive to a shock wave but very sensitive to impact of particles. This is attributed to the fact that these expls contain some nongelatinized NG Nitroglycol, the initiation of which occurs accdg to a thermal process]... 

Mediterranean Basin. Additional studies of the finer particle fractions and chemical characterisation will elucidate the sources and impact of particle pollution in the area. Particularly there is a lack of data on carbonaceous aerosol that organic and elemental carbon observations could help to distinguish the contribution of secondary versus primary sources. 

Environmental impact of particles emitted from Windscale piles, 1954-7. The Science of the Total Environment, 63,139-60. 

Fig. 6.3. Efficiency of impaction of particles on needles and twigs. Data of Belot (1975) using dye particles on pine needles (x), Little (1979) using polystyrene particles on sticky ( ) and non-sticky (O) pine needles, and Carter (1965) using ascospore octads on apricot twigs (A).

The effect of the collisional force due to the impact of particles should be included when accounting for the motion of a particle except in a very dilute gas-solid flow situation. Basic mechanisms of collision between two particles or between a particle and a solid wall are discussed in Chapter 2. The collisional force between a particle and a group of neighboring particles in a shear suspension is discussed in 5.3.4.3. In a very dense system where particle collisions dominate the flow behavior, collisional forces can be described by using kinetic theory, as detailed in 5.5. The key equations derived in other chapters pertaining to the collisional forces can be summarized in the following. 

This example indicates that impact of particles among themselves or with the wall is in general not an effective means of heat transfer in gas-solid flows. 

A probable mechanism of erosion for plastics is illustrated in Fig. 6.2 [Briscoe and Evans, 1987]. Initially, a series of plastically deformed grooves can be formed by the abrasion of particle flows. The subsequent directional or random impacts of particles may push the deformed grooves from side to side. The fatigue limits of the plastics would eventually make the ridges between the grooves detach to form ribbonlike debris. Brittle cracks also occur when the wear tracks interact. 

Particle attrition can be caused by the relative motion of mechanical parts such as a blade in the flow of bulk particles by the impact of particles with a solid wall or with other... 

Impact of Particle Size of API and Excipients on Product Uniformity... 

Particle size control of the API is often an important development strategy to consider, particularly when considering the impact of particle size on the quality attributes of the final chug product or the chug product manufacturing process. The physical properties of the API can affect the chug product quality in several ways ... 

The probability of impact of particles with the wetted part of their surfaces is the product of both probabilities... 

In this section, we concentrate on the fundamental impact of particle size reduction on magnetization processes in individual particles. Although not directly related to coercivity, the classical effect of single domain particle formation is described. At small particle size, reversal by coherent rotation tends to be favoured with respect to nucleation/pinning-depinning finally thermal activation effects and macroscopic quantum tunnelling are discussed. 

Figure 4 shows the actual dilution system. The tower at left is the primary chamber. Its large volume is important for use with aerosols because even at high air flow rates the velocity is low, which allows time for solvent evaporation when wet aerosol droplets are introduced. Low velocity also helps prevent impaction of particles with the chamber walls. 

For any particular particle leaving the source S and ultimately striking the detection screen D, the value of

interaction with the detector at slit A. However, this value is not known and cannot be controlled for all practical purposes it is a randomly determined and unverifiable number. The value of

pattern observed on the screen is the result of a large number of impacts of particles, each with wave function xV(x) in equation (1.50), but with random values for probability density P,p(x) is just the sum of PA(x) and PB(x), giving the intensity distribution shown in Figure 1.9(b). 

Sonnergaard, J. M. (2000), Impact of particle density and initial volume on mathematical compression models, Eur. J. Pharm. Sci., 11, 307-315. 

The impact of particle size also follows similar principles in metal CMP. Lu and coworkers [87] confirmed the contact-area mechanism for material removal in copper CMP with silica abrasives. It was observed that the material removal rate increased with the increase in the specific surface area of the abrasives in the slurry. Bielman and coworkers [88] conducted a similar investigation and found that the removal rate of tungsten decreased with the increase in alumina particle size from 0.29 to 2 pm at 4.5% slurry concentration. 

In 1993 the US Department of Commerce estimated the impact of particle science and technology to industrial output to be one trillion dollars annually in the United States. One third of this was in chemicals and allied products, another third was in textiles, paper and allied products and the final third was in food and beverages, metals, minerals and coal. 

Aerosol concentrations and size distributions can be investigated remotely using sun-photometry. Characterization of volcanic aerosol is important in smdies of plume chemistry, atmospheric radiation, and the environmental and health impacts of particle emissions. Watson and Oppenheimer (2000, 2001) used a portable sun-photometer to observe tropospheric aerosol emitted by Mt. Etna. They found distinct aerosol optical signatures for the several plumes emitted from Etna s different summit craters, and apparent coagulation of particles as the plume aged. More recently. Porter et al. (2002) have obtained sun-photometer and pulsed lidar data for the plume from Pu u O o vent on Kilauea, Hawaii, from a moving vehicle in order to build profiles of sulfate concentration. 

Although the motor power consumption is strongly correlated with the torque on the impeller,it is less sensitive to high frequency oscillations caused by direct impact of particles on the blades as evidenced by Fast Fourier Transform (FFT) technique. ... 

Interparticle colhsions due to turbulence in a free jet Collisions between particles accelerated by opposed jets Impact of particles on a target... 

For most dry process applications, the major impact of particle composition and precipitator performance is related to the electrical resistivity of the deposited material. The value of the electrical resistivity of the deposited particles can result in the required exposure/ contact time within the precipitation fields varying by a factor of 4 or more. 

At hypervelocities (e.g. in hypersonic aircraft or rockets), the Impact of particle matter on a plastic surface transfers a tremendous amount of kinetic energy within a small region. This energy is partitioned into heat, light, explosive mass ejection, and shock wave generations. The temperatures are of sufficient... 

The analogous problem of impaction of particles on spheres has been studied for application to gas cleaning In packed beds and aerosol senibbing by droplets. Numerical computations of the impaction efliciency for point particles in in viscid flows around spheres have also been made. Before comparing the numerical computations with the available data, we consider theoretical limiting values for the Stokes number for impaction on cylinders and spheres. 

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