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Coarse parameters

As reported before [Ref. 1], there are some essential parameters that influence the results of the testing, such as the thickness of the expired specimen, the quality and coarse grain of the built-in concrete, and the properties of the specimen-surface for the transducer s coupling. At the onset of testings none of tlrese parameters were available. As a result, we had to carry out preliminary investigations in order to prove the applicability of our testing-technique "in situ". [Pg.754]

By virtue of their simple stnicture, some properties of continuum models can be solved analytically in a mean field approxunation. The phase behaviour interfacial properties and the wetting properties have been explored. The effect of fluctuations is hrvestigated in Monte Carlo simulations as well as non-equilibrium phenomena (e.g., phase separation kinetics). Extensions of this one-order-parameter model are described in the review by Gompper and Schick [76]. A very interesting feature of tiiese models is that effective quantities of the interface—like the interfacial tension and the bending moduli—can be expressed as a fiinctional of the order parameter profiles across an interface [78]. These quantities can then be used as input for an even more coarse-grained description. [Pg.2381]

The characteristic separation curve can be deterrnined for any size separation device by sampling the feed, and coarse and fine streams during steady-state operation. A protocol for determining such selectivity functions has been pubHshed (4). This type of testing, when properly conducted, provides the relationships among d K, and a at operating conditions. These three parameters completely describe a size separation device and can be used to predict the size distribution of the fine and coarse streams. [Pg.434]

AH three parameters, the cut size, sharpness index, and apparent bypass, are used to evaluate a size separation device because these are assumed to be independent of the feed size distribution. Other measures, usually termed efficiencies, are also used to evaluate the separation achieved by a size separation device. Because these measures are dependent on the feed size distribution, they are only usefiil when making comparisons for similar feeds. AH measures reduce to either recovery efficiency, classification efficiency, or quantitative efficiency. Recovery efficiency is the ratio of the amount of material less than the cut size in the fine stream to the amount of material less than the cut size in the feed stream. Classification efficiency is defined as a corrected recovery efficiency, ie, the recovery efficiency minus the ratio of the amount of material greater than the cut size in the fine stream to the amount of material greater than the cut size in the feed stream. Quantitative efficiency is the ratio of the sum of the amount of material less than the cut size in the fine stream plus the amount of material greater than the cut size in the coarse stream, to the sum of the amount of material less than the cut size in the feed stream plus the amount of material greater than the cut size in the feed stream. Thus, if the feed stream analyzes 50% less than the cut size and the fine stream analyzes 95% less than the cut size and the fine stream flow rate is one-half the feed stream flow rate, then the recovery efficiency is 95%, the classification efficiency is 90%, and the quantitative efficiency is 95%. [Pg.434]

There are relationships between the independent size separation device parameters and the dependent size separation efficiencies. For example, the apparent bypass value does not affect the size distribution of the fine stream but does affect the circulation ratio, ie, the ratio of the coarse stream flow rate to the fine stream flow rate. The circulation ratio increases as the apparent bypass increases and the sharpness index decreases. Consequendy, the yield, the inverse of the circulating load (the ratio of the feed stream flow rate to the fine stream flow rate or the circulation ratio plus one), decreases hence the efficiencies decrease. For a device having a sharpness index of 1, the recovery efficiency is equal to (1 — a). [Pg.434]

Zinc dust is smaller in particle size and spherical in shape, whereas zinc powder is coarser in size and irregular in shape. The particle size of zinc dust, important in some appHcations, is controUed by adjusting the rate of condensation. Rapid cooling produces fine dust, slower condensation coarse dust. In the case of zinc powder, changes in the atomization parameters can be employed to change particle size to some degree. The particle size distributions for commercial zinc powders range from 44 to 841 p.m (325—20 mesh). The purity of zinc powders is 98—99.6%. [Pg.415]

Three parameters define the performance of a classifier. These are cut size, shaipness of cut, and eapaeity. Cut size, X50, is the size at which 50 percent of the material goes into the coarse product and 50 percent into the fine. (This should not be confused with the cutoff size, a name sometimes given to the top size of the fine product .)... [Pg.1835]

The mechanical properties of Watts deposits from normal, purified solutions depend upon the solution formulation, pH, current density and solution temperature. These parameters are deliberately varied in industrial practice in order to select at will particular values of deposit hardness, strength, ductility and internal stress. Solution pH has little effect on deposit properties over the range pH 1 0-5-0, but with further increase to pH 5 -5, hardness, strength and internal stress increase sharply and ductility falls. With the pH held at 3-0, the production of soft, ductile deposits with minimum internal stress is favoured by solution temperatures of 50-60°C and a current density of 3-8 A/dm in a solution with 25% of the nickel ions provided by nickel chloride. Such deposits have a coarse-grained structure, whereas the harder and stronger deposits produced under other conditions have a finer grain size. A comprehensive study of the relationships between plating variables and deposit properties was made by the American Electroplaters Society and the results for Watts and other solutions reported... [Pg.531]

The concentration of K2TaF7 in the initial melt is the main parameter controlling the particle size and surface area of the reduced primary powder [598]. Typically, the increased concentration of K2TaF7 leads to the formation of coarse tantalum powder. According to Yoon et al. [599], the diluent prevents a strong increase in the temperature of the melt that is caused due to the exothermic effect of the reduction process. Based on the investigation of the reduction process in a K2TaF7 - KC1 - KF system, it was shown that increased amounts of diluent lead to a decrease in particle size of the obtained tantalum powder. [Pg.335]

Equation (7.5) Indicates that the velocity constant should increase linearly with the average particle size. The solvent front velocity should be larger for coarse-particle layers than for fine-particle layers which is. in good agreement with experimental observations [27]. Also, from equation (7.5) we see that the velocity constant depends linearly on the ratio of the surface tension of the solvent to its viscosity and that solvents which maximize this ratio (and not just optimize one of the parameters) are preferred for TLC [8,30]. The contact angle for... [Pg.333]

Table 5.1 Parameters of the united atom force field for polyethylene used as the atomistic input for the coarse-graining procedure. The Lennard-Jones parameters pertain to CH2-group interaction, since chain ends were not considered in the coarse-graining. [Pg.120]

Metadynamics defines coarse-grained variables which are assumed to be slow coordinates of the system. Those coordinates are similar to the order parameters considered earlier in this chapter. The coarse variables are evolved independently following a steepest-descent equation. In the case of a single variable, Laio and Parrinello [34] use... [Pg.149]


See other pages where Coarse parameters is mentioned: [Pg.1724]    [Pg.267]    [Pg.1724]    [Pg.267]    [Pg.2363]    [Pg.2369]    [Pg.2383]    [Pg.495]    [Pg.483]    [Pg.312]    [Pg.188]    [Pg.418]    [Pg.193]    [Pg.559]    [Pg.615]    [Pg.638]    [Pg.1053]    [Pg.98]    [Pg.327]    [Pg.102]    [Pg.107]    [Pg.137]    [Pg.139]    [Pg.146]    [Pg.153]    [Pg.198]    [Pg.200]    [Pg.244]    [Pg.165]    [Pg.92]    [Pg.175]    [Pg.178]    [Pg.179]    [Pg.603]    [Pg.303]    [Pg.339]    [Pg.78]    [Pg.111]    [Pg.492]   
See also in sourсe #XX -- [ Pg.198 ]




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