Spherical or irregularly shaped

Panicles entrained in the airstream deposit along the airway as a function of size, density, airstream velocity, and breathing frequency. Sizes of rougjily spherical or irregularly shaped particles arc commonly characterized by relating the settling velociiy of the particle to that of an idealized spherical particle. For example, an irregular particle which settles at the same rate as a 5 pm spherical particle has a mean mass aerodynamic diameter (MMAD) of. 5 pm. Since spherical particle mass, is a function of particle diameter, J... 

The particle size of the stationary phase material plays a very vital and crucial role in HPLC. In fact, high-elficiency-stationary-phase materials have been researched and developed exclusively for HPLC having progressively smaller particle size termed as microparticulate column packings. These silica particles are mostly uniform, porous, with spherical or irregular shape, and having diameter ranging from 3.5 to 10 pm. 

Rubber as the Disperse Phase. In polyblend systems, a rubber is masticated mechanically with a polymer or dissolved in a polymer solution. At the conclusion of blending, a rubber is dispersed in a resin as particles of spherical or irregular shape. We can further subdivide this system into three classes according to the major intermolecular forces governing adhesion (a) by dispersion forces—e.g., the polyblend of two incompatible polymers, (b) by dipole interaction—e.g., the polyblend of polyvinyl chloride and an acrylonitrile rubber (56), and (c) by covalent bond—e.g., an epoxy resin reinforced with an acid-containing elastomer reported by McGarry (43). 

The stationary phase in HPLC is the solid support contained in within a specified column over which the mobile phase flows effecting the separation of the individual components. The HPLC column is normally fabricated using 100- to 300-mm long stainless steel tubes with an internal diameter of 2-5 mm. They are packed with porous, microporous, spherical, or irregularly shaped particles, or particles with specific coatings with the following characteristics. 

Conidia subglobose to short-ellipsoidal, sometimes short-falcate, often cyanophilic dictyochlamydospores spherical or irregularly shaped, often present in the aerial mycelium or in the agar mostly parasites of nematode cysts or saprotrophic, soilborne crystals absent... 

Bronze 9/1 Copper to tin ratio <60 pm Spherical or irregular shape ... 

Hypercrosslinked polystyrenes strongly retain many organic compounds (Table 10.4) therefore, the chromatographic properties of Styrosorbs were investigated using a short, 30 cm x 1.5 mm ID column. The column was packed with spherical or irregularly shaped particles, with diameters of 0.16—0.20mm [20]. 

The stationary phase for normal-phase chromatography is silica gel that is more uniform in particle size (20-40 pm), has a pore size of 80-300 A, and spherical or irregular particle shape. In normal phase, peptides elute in order of decreased hydrophobicity, with the most hydrophilic peptide eluting last at the highest concentration of the hydrophilic solvent. This would be the aqueous or alcoholic component of the buffer system, which is also often acidic. 

Bart 70 Janez — Russian Federation origin. Pink tubers, spherical or irregular pear shaped. Maintained by Institut National de la Recherches Agronomique (INRA), UMR-DGPC, Montpellier, France (INRA MPHE001467) limited immediate availability. 

Shape of particle (spherical or irregular and ease of packing)... 

Particle shape spherical or irregular Pore diameter, A 58-240... 

The shape of granular material from compaction/granulation is irregular and angular (Fig. 8.5). This is in stark contrast to the spherical or spheroidal shapes of agglomerates... 

The drop generator established by Yim et al. for producing solder balls is shown in Fig. 26.5 as an example for a device suitable for use with melts [20]. This device combines a heatable reservoir for the metal melt with a solenoid-driven vibrator, which transmits oscillations by a disk mounted at the end of a shaft to the molten metal bath. The orifice piece is manufactured from ruby. The solidification of the solder drops is controlled by immersing them into a silicone oil bath. Particles produced with this device are nicely spherical, with typical diameters of 780 pm and a standard deviation of 26 pm. Apart from the spherical particles, irregular shapes are also observed, which are due to coalescence of the drops, either in the drop stream before entry into the oil bath, or in the oil bath prior to formation of a solid shell on their surface. 

Ceramic powders usually consist of particles with different sizes that are distributed over a certain range. Some powders have a very narrow size distribution, such as those prepared by chemical precipitation under well-controlled conditions, whereas others may exhibit a broad size distribution, such as those made through mechanical milling or solid-state reaction. Some particles have spherical, near spherical, or equiaxial shapes, while there are many cases where the powders are irregular in shape, including rod, wire, fiber, disk, plate, and so on. The importance of characterizing size and size distribution of ceramic particles is due to their effects in the consohdation and sintering behaviors of the powders. 

If JIT is too large, then the column packing is poor if it is too small, this indicates a blockage. K is always a function of particle shape (spherical or irregular). 

Silica packings are always obtained with a particle distribution, i. e., a stated 5-pm particle diameter is an average diameter. The polydispersity of a silica powder is related to the width of the particle size distribution. It can be given by the ratio d dio, particle diameters of which 90% and 10% of the particle are smaller than or equal to, respectively. The ratio d dio should be as close to unity as possible (monodisperse silica). Particle size is always associated to particle shape which can be spherical or irregular. Table 4-1 lists the particle size and shape of some commonly used commercial silica-based LC packings. 

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