Mesh size defined

In these equations, the second subscript, n + 1, has been dropped all the terms on the right-hand side have been collected into the Ci, and the a4 and bt are constants for a given mesh size, defined by the relation of these equations to the set (5-42) to (5-44). The next operation is to construct a set of coefficients from the [Pg.248]

Screen sizes are defined in two ways by a mesh size number for small sizes and by the actual size of opening in the screen for the larger sizes. There are several different standards in use for mesh size, and it is important to quote the particular standard used when specifying particle size ranges by mesh size. In the UK the appropriate British Standards should be used BS 410 and BS 1796. A comparison of the various international standard sieve mesh sizes is given in Volume 2, Chapter 1. 

If the laboratory sample has been prepared in a particular way to pass a specific mesh size, the coefficient of variation of the result for one component varies inversely with m, where m is the mass of the test portion. A sampling constant (Ks) can be defined by the following ... 

In the IBM, the presence of the solid boundary (fixed or moving) in the fluid can be represented by a virtual body force field -rp( ) applied on the computational grid at the vicinity of solid-flow interface. Considering the stability and efficiency in a 3-D simulation, the direct forcing scheme is adopted in this model. Details of this scheme are introduced in Section II.B. In this study, a new velocity interpolation method is developed based on the particle level-set function (p), which is shown in Fig. 20. At each time step of the simulation, the fluid-particle boundary condition (no-slip or free-slip) is imposed on the computational cells located in a small band across the particle surface. The thickness of this band can be chosen to be equal to 3A, where A is the mesh size (assuming a uniform mesh is used). If a grid point (like p and q in Fig. 20), where the velocity components of the control volume are defined, falls into this band, that is... 

The location of any individual tube changes with time but it has dimensions which are constant. If the tube contour is of length L we can define a parameter a, related to the mesh size of the polymer ... 

Tropocollagen molecules are firmly linked together, particularly at their ends, by covalent networks of altered lysine side chains. The number of these links increases with age. Type IV collagens form networks with a defined mesh size. The size-selective filtering effect of the basal membranes in the renal glomeruli is based on this type of structure (see p. 322). 

He defined a shape factor f as the ratio of the average volume of all particles having a maximum linear dimension equal to the mesh size of a screen to that of a cube which will just pass the same screen, f = 1.00 for cubes and 0.524 for spheres. For most materials f 0.5. The particle size distribution factor g is the ratio of the upper size... 

Table III presents the reaction rate and the induction time for reaction (as defined in Figure 2) for the five coals studied. These data were taken under the following conditions 109.5°C., 1 N sodium hydroxide, and 8.5 atm. of oxygen partial pressure. The mesh size of the coals was through 60 mesh on 100 mesh. The reaction rates are based on the external area of the coal particles.

To test the melt-down properties, a rectangular block of ice cream of defined size is taken from the storage cabinet (e.g., at -20°C) and is placed on a wire gauze (mesh size, e.g., 4 mm) at a controlled temperature between 15 and 25°C. The melting may be followed... 

Plastic powder form used usually has a particle size of 35 mesh (74 to 2000 pm). The particle size of powders is usually quantified in terms of the mesh size. This relates to the number of mesh openings per inch in the sieve used to grade the powder that are defined in industry mesh size standards. 

By defined heating of the second stage, each temperature between 4 K and 100 K can be adjusted. The reference cryosorption material is a coconut-shell-based, highly activated granular charcoal (CHEMVIRON CARBON, type SC-II, US mesh size 12x30), with the sample masses being about 2.5 g. 

The ability of a solute to diffuse within a hydrogel has been described in terms of the probability of a solute of characteristic size (r, defined as the radius of a sphere of equal volume to the solute molecule) passing through an opening equal to the mesh size of the gel (. This probability is taken to be a linear function of the ratio of r/. Therefore, the gel phase diffusivity of a solute can be related to its liquid phase diffusivity, molecular volume, and gel mesh size [70,71]. 

The terms dispersion characteristic and respective or constituent amount need further explanation. The dispersion characteristic, also called particle size, grain size, fineness index, or dispersion parameter, is a physical property which can be measured and defines, in a suitable way, the dispersity or, in a narrower sense, the dimensions of the particles. In the case of spheres, diameter would be the most descriptive dispersion characteristic. If the particles are irregularly shaped, other linear dimensions must be chosen, e.g. the statistical chord lengths according to Martin or Feret (Figure 21), the mesh size of a screen through which the particle just passes, or so-called equivalent diameters. Equivalent diameters are calculated from other dispersion characteristics, which must not necessarily be linear dimensions, using mathematical relationships and/or physical laws. 

Foam Stability. A plastic cylinder (diameter 7 cm, height 9 cm) having a wire net with a mesh size of 1 mm x 1 mm is filled with foam and the amount of foam is found by weighing (A gram). The cylinder is then placed on a funnel on top of a glass cylinder of 100 ml. After 30 minutes the weight (B) of drained liquid in the glass cylinder is determined. The foam stability FS is defined by the equation ... 

Mesh size is a conventional term that is used to define the size of particles constituting an adsorbent, the alternative to the use of this term being, of course,... 

A few commercially available ion-exchange resins are used for most published separations. They are defined by functional group, ion-exchange capacity (in meq g ), mesh size, cross-linkage, density, and ionic form. Each descriptor affects the value of Dy in qualitatively understood ways (Korkisch 1989), so that the analyst may select a resin with optimum characteristics for the intended separation. The ionic form of the purchased resin can be replaced by washing the resin with a solution that contains the new ion until complete conversion is demonstrated by tests of the effluent solution. 

The first such approach was reported by Takami and Ozaki, who treated mono-layers of 1,15,17,31-dotriacontatetrayne under UHV conditions with UV-light, and then investigated the product using STM (Scheme 28.9) [127]. Although the corresponding image showed periodic features in reasonable dimensions, it remained questionable as to how many of the diacetylene units and, perhaps even more so, how many of the terminal acetylene units, had actually reacted to produce the proposed periodic fisherman s net with a defined mesh-size. 

A local correlation length f(x) was defined (the length over which excluded volume effects are screened), the polymer layer at the interface then resembling a network of variable mesh size (x). When the hydrodynamic equation is integrated up to a distance correspjonding to the longest mesh size Rp (the Flory radius of polymers in solution), it is found that the hydrodynamic thickness scales... 

Mica products are usually analyzed by screening to determine particle distributions. Specifications typically include minimum and maximum values for the amount of mica passing or retained on screens of varying mesh sizes. Another value often used for a material specification is loose bulk density. Laser particle size analysis is also being used to some extent to define mica products. One should remember that most other minerals are measured by an instrument called a sedigraph, which measures the size of particles based on their settling rate. This procedure can be used with very small low-aspect ratio minerals such as calcium carbonate, talc, silica, very small particle size mica, and aluminum trihydrate but cannot be used for analysis of most mica products. Sedigraph particle size values for very small mica products are about one-half to one-third of the values obtained by laser diffraction. 

A standard sieve series usually consists of a set of sieves with apertures covering a wide range from microns to centimeters. The sieve size is defined as the minimum square aperture through which the particles can pass. Sieves are often referred to by their mesh size, that is, the number of wires per linear inch. Mesh size and the wire diameter determine the aperture size. The ratio of aperture of a given sieve to the aperture of the next one in a... 

---