Particle individual

A wide variety of particle size measurement methods have evolved to meet the almost endless variabiUty of iadustrial needs. For iastance, distinct technologies are requited if in situ analysis is requited, as opposed to sampling and performing the measurement at a later time and/or in a different location. In certain cases, it is necessary to perform the measurement in real time, such as in an on-line appHcation when size information is used for process control (qv), and in other cases, analysis following the completion of the finished product is satisfactory. Some methods rapidly count and measure particles individually other methods measure numerous particles simultaneously. Some methods have been developed or adapted to measure the size distribution of dry or airborne particles, or particles dispersed inhquids. 

Particle individual unit of a pigment that can have any shape or structure... 

How is it possible to measure out a specific number of atoms or molecules Rather than counting these particles individually, chemists can use a scale that measures the mass of bulk quantities. Because different atoms and molecules have different masses, however, a chemist can t simply measure out equal masses of each. Say, for example, he needs the same number of carbon atoms as oxygen molecules. Measuring equal masses of the two materials would not provide equal numbers. 

In addition to the patent literature available on the production of BR in the gas-phase there is some scientific literature which mainly refers to the modeling of reaction kinetics. Details on the experimental procedure for the determination of the macroscopic kinetics of the Nd-mediated gas-phase polymerization of BD in a stirred-tank reactor are reported [568,569]. Special emphasis is given to video microscopy of individual supported catalyst particles, individual particle growth and particle size distribution (PSD). These studies reveal that individual particles differ in polymerization activity [536,537,570,571]. Reactor performance and PSD are modeled on the... 

D-4179 Single Pellet Crush Strength of Formed Catalyst Shapes Strength of spherical or tablet shaped particles individually crushed between two flat surfaces ... 

There are several scanning methods that measure particles individually in a fluid stream. These methods include field scanning, light diffraction, and photon spectroscopy methods. They are described briefly in Perry s Handbook (Snow et al., 1999). 

In Chapter 3, you learned that a liquid can take the shape of its container but that its volume is fixed. In other words, the particles in a liquid can flow to adjust to the shape of a container, but the liquid cannot expand to fill its container. Kinetic-molecular theory predicts the constant motion of the liquid particles. Individual liquid molecules do not have fixed positions in the liquid. However, forces of attraction between liquid particles limit their range of motion so that the particles remain closely packed in a fixed volume. 

From the helium-mercury measurements the pore volume, the solid density, and the porosity of the catalyst particle can be determined. Values of p are of the order of 0.5, indicating that the particle is about half void space and half solid material. Since overall void fractions in packed beds are about 0.4, a rule of thumb for a fixed-bed catalytic reactor is that about 30% of the volume is pore space, 30% is solid catalyst and carrier, and 40% is void space between catalyst particles. Individual catalysts may show results considerably different from these average values, as indicated in Examples 8-4 and 8-5. 

For example, many methods are available for the chemical analysis of deposited aerosol particles. Individual particles can be analyzed as well as heavier deposits. A serious gap in aerosol instrumentation is the lack of instrument.s for on-line measurement of aerosol chemical constituents without removing them from the gas. Very large amounts of information on multicomponent, polydi.sperse aerosols would be generated by an instrument capable of continuously sizing and chemically analyzing each particle individually, thereby permitting the determination of the size-composition probability density function, g (Chapter I), From this function, in principle, many of the chemical... 

This argiimcntation is further supported by the predictions of a simple mean-field theory of the ferroelectric transition, which was originally presented in Ref. 257. Within this theory, we neglect any stratification (i.e., inhomogeneities of the local density) as well as any oscillations in the order parameter (which are indeed observed in the computer simulations). We also neglect nontrivial interparticle correlations. Our system can then be viewed as a system composed of N uncorrelated dipolar particles individually interacting with the mean field... 

Basically all these essential founding efforts were restricted by a seeming law of nature that, as far as individual atoms were concerned, You can look but you better not touch Following the work by Bohr and others, quantum mechanics and statistical mechanics became computational means of calculating the observed properties of populations of billions of molecules. But consideration of such massive collections seemed to place an even greater barrier between the commonsense world and the world of individual particles. Individual atoms became not only (almost) officially untouchable, but downright weird in their behavior, neither here nor there but smears of probability in space-time, forever beyond human ken. 

There are several known approaches to classification of individual crystals in accordance with their symmetry and crystallochem-istry. The particles that form a crystal are distributed in certain points in space. These points are separated by certain distances (translations) equal to each other in any chosen direction in the crystal. Crystal lattice is a diagram that describes the location of particles (individual or groups) in a crystal. The lattice parameters... 

This is realized by agitation/fluidization of solid particles (individual) in an airflow rate—hot or cold. Then the coating product is sprayed (nozzle) on the moving particles, giving progressively a homogeneous layer. 

Optical microscopy is often used as an absolute method of analysis of particle size, since it is the only method that allows on the one hand, to examine the particles individually for shape and composition, and on the other hand, to measure the diameter with a resolution of 200 nm (for optical microscopes) and particle sizes as low as 5 p,m. It can provide information on the size distribution in number and form. Different diameters can be measured the equivalent diameter of Martin, dm, Feret diameter, dp, the diameter of the projected area, da, etc. New microscopes use cameras to output a digital image for analysis. Below 5 turn, the images are blurred due to diffraction effects. 

In addition to measurements of the total charge of the particles (with subsequent calculation per individual particle), individual particle charges have been measured for polyvinyl chloride when it is detached from a metal surface [19] ... 

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