Factor resistance

Bacteria produce chromosomady and R-plasmid (resistance factor) mediated P-lactamases. The plasmid-mediated enzymes can cross interspecific and intergeneric boundaries. This transfer of resistance via plasmid transfer between strains and even species has enhanced the problems of P-lactam antibiotic resistance. Many species previously controded by P-lactam antibiotics are now resistant. The chromosomal P-lactamases are species specific, but can be broadly classified by substrate profile, sensitivity to inhibitors, analytical isoelectric focusing, immunological studies, and molecular weight deterrnination. Individual enzymes may inactivate primarily penicillins, cephalosporins, or both, and the substrate specificity predeterrnines the antibiotic resistance of the producing strain. Some P-lactamases are produced only in the presence of the P-lactam antibiotic (inducible) and others are produced continuously (constitutive). 

FIG. 17-57 Resistance factors for dust layers. Theoretical curves given are based on Eq, (20-78) for a shape factor of 0,5 and a true particle specific gravity of 2,0, [Williams, Hatch, and Greenhurg, Heat, Piping Air, Cond, i2, 259 (1940) Mumford, Markson, and Ravese, Trans, Am, Soc, Mech, Eng, 62, 271 (1940) Capwell, Gas, 15 31 (August 1.93.9)],... 

TABLE 17-6 Resistance Factors and Air Permeabilities for Typical Woven Fabrics... 

Once the diameter is known, the Reynolds number. Re can be computed and the friction factor f obtained from Figure 21. Assuming a straight length of pipe for L = 5(X) ft, N (line resistance factor) can be calculated. Next Gj, is calculated based on the downstream pressure and G/G j evaluated. From Figure 20 the ratio Pj/Pfl can be obtained. Since Pj is known, Pq can then be calculated. The pressure at the inlet of the knock-out drum is given by Pq -I- 0.5 psi. Table 6 provides typical values of resistance coefficients for various pipe fittings. 

The certified flow resistance factor, K[, is a dimensionless factor used to calculate the velocity head loss that results from the... 

Certified resistance factors can be provided by the rupture disc manufacturer for each disc model. 

Resistance factors are taken from the Moody chart, when the Reynolds number and roughness are known. 

A, = area of inside of. surface for heat transfer, such as coil, flat surface, or other barrier, sq ft/ft h = inside heat transfer fluid side coefficient, in coil, flat plate, or otlier barrier, Btu/hr/sq fl/°F ro = fouling resistance (factor) associated wTth fluid on outside (tank process side) of heat transfer... 

Zanker has presented a graphical technique for determining the fouling resistance (factor) for process or water fluid systems based on selected or plant data measurements, as shown in Figures 10-43A, 10-43B, and 10-43C. The design determination procedure presented by ZankeD is quoted here and used by permission from Hydrocarbon Processing... 

Wall Resistance Factors— Cast Iron Cooling Sections ... 

Pressure drop is calculated by k x velocity pressure, where k is the resistance factor for the above items other than duct friction and is found from Table 29.1 or similar references. Velocity pressure is found by density x velocity, taking standard density at 1.2kg/m°, or from Table 29.2. 

The insect s choice of food may be governed to a considerable extent, as ours is, by attractants and repellents. In many instances, the actual insecticidal action of plant extractives may be due primarily to an artificially high level of application, while, in fact, the parent plants are only repellent in the field. This repellency may appear to be resistance on the part of the plant, and the chemistry of such resistance factors has begun to receive much-needed attention. For example, Smissman and his coworkers have examined the chemical basis for the inherited resistance of some strains of corn to attack by the European corn borer. 6-Methoxybenzoxazolinone (X) was isolated (2, SO) and shown to be one of the principal resistance factors, and a number of synthetic analogs were found to... 

Note NaCh = sodium channel RF = resistance factor, which is LDjq resistant strain/LDjQ susceptible strain GABA = gamma amino butyric acid receptor PBO = piperonyl butoxide. 

This model (known as the SDR model) uses the log mean relaxation of 100% brine saturated rock as the estimator of the effective pore size [32]. This limits the method to rocks in the absence of hydrocarbons, which models permeability to be proportional to the porosity to the fourth power and log mean T2 to the second power, Eq. (3.6.6). Variations of this method use different exponents or the formation resistivity factor rather than porosity [2] ... 

Varieties are very different in their susceptibility to disease, and this is of great importance to the organic farmer. It makes sense to consider a varietal diversification scheme and to select at least three varieties for every farm, so that each has a different resistance factor. These different varieties can be sown in adjacent fields. 

American Institute of Steel Construction. Manual of Steel Construction, Load ) Resistance Factor Design (LRFD). First Edition. Chicago, IL. 1986. 

FIGURE 6.1 A Poppe plot for the required plate number in conventional HPLC. The parameters are taken from Poppe s original paper (Poppe, 1997). The parameters are maximum pressure AP = 4x 107 Pa, viscosity / = 0.001 Pa/s, flow resistance factor

diffusion coefficient D= lx 1CT9 m2/s, and reduced plate height parameters using Knox s plate height model are A — 1, B— 1.5, C = 0.05. 

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