Particle elastic

The foUowing variables can affect a material s bulk density. (/) Moisture higher moisture content often makes a material mote compressible. (2) Particle size and shape often, the finer the bulk soHd, the mote compressible it is. The shape of the particles can affect how they fit together and thein tendency to break while being compacted. (3) Temperature some materials become mote compressible as thein temperature increases. This could be due, for example, to softening of the particles. (4) Particle elasticity elastic materials tend to deform significantly when they ate compressed. 

Figure 11 Total cross sections due to proton (left) and alpha particle (right) impact on water vapor. Total ionization cross sections were obtained by fitting polynomial functions to the experimental data [198-200]. The curve for excitation was assumed to be the same between protons and alpha particles. Elastic scattering was evaluated by the classical mechanics trajectory calculations [Eqs. (16) and (17)].

With respect to plasma chemistry, the most important collision processes in a weakly ionised plasma occur between charged particles and neutral particles. Elastic collisions concern principally coulombic and polarisation scattering processes. Coulombic scattering applies when the characteristic interaction time... 

All the systems presented in the previous section, although very different in composition and structure, can be viewed as dispersions of soft and elastic spherical particles. However, the origin of the particle elasticity can be very different, depending on the architecture and composition. 

The importance of the amorphous glassy microstructure of soft particle dispersions is reflected by the great influence that the particle elastic modulus has on yielding and flow. The yield stresses of colloidal pastes and of emulsions scales like the shear modulus [13, 133, 134]. In Sect. 5, the flow curves of soft particle glasses will be shown to exhibit a remarkable universal behavior in terms ofa unique microscopic time scale tliat involves the shear modulus [13]. In Sect.4, the slip velocity... 

Figure 4.2 Two common interactions between light and matter, (a) At certain angles, light is refracted when passing from one medium to another (at dashed line), changing direction and velocity, (b) When light hits a particle, elastic collisions result in changes in direction and phase (Rayleigh scattering), whereas inelastic collisions result in frequency changes (Raman effect).

In other words, the elastic modulus of the cubic structured gel, E, should increase with adhesion W, particle elasticity E and Poisson s ratio v, but decrease as the particle diameter D rises. These equations are interesting when we apply them to common gels such as silica, alumina, titania, or zirconia. For example, for 1 (im diameter silica particles, = 70GPa, fF = 0.2Jm because of the hydrated surface and v is 0.3. The contact spot diameter turns out to be 32 nm from Equation (11.1), only 3% of the particle diameter. It is salutary to note that such tenuous adhesive contact between the particles is responsible for the gel behavior. The Young s modulus ofthe gel from Equation (11.7), assuming a cubic structure, is 0.75 GPa. This is close to the measured values for silica gel, which is about a hundred times more compliant than silica itself. Let us now consider the preparation and measurement of such gels. 

Depending on the energy range of the primary particle, elastic and inelastic collisions take place. Elastic collisions dominate interactions in the kiloelectron volt range. Elastic collisions can be described by the nuclear stopping power, which is defined by the energy loss of the primary particle per path length. 

Particle—Elastic glass plate impact, which mimics the impact between two particles, due to a stiff elastic material of the used plate. 

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