Flow Performance Evaluation

Kroger, D. G. (2004) Air-cooled Heat Exchangers and Cooling Towers Thermal-flow Performance Evaluation and Design, Vol. 1 (PennWell). 

In some organizations, designated individuals have specific responsibility for eliciting detailed information from operational staff on the immediate and underlying causes of incidents. An example is the Human Performance Evaluation System (HPES) developed for the nuclear industry, which is described in Bishop and Larhette (1988). These coordinators provide a certain level of guaranteed irrununity from sanctions which allows individuals to be frank about the contributory causes that they may not be willing to discuss in an open forum. As discussed earlier, the need for this approach is a consequence of the fact that in many organizations a blame culture exists which is likely to inhibit a free flow of information about the causes of accidents. 

Flow cytometric evaluation of bone marrow and peripheral blood is performed to characterize the type of leukemia as well as to detect specific chromosomal rearrangements. The bone marrow at diagnosis usually is hypercellular, with normal hematopoiesis being replaced by leukemic blasts. At diagnosis, a lumbar puncture is performed to determine if CNS leukemia is present. 

ESDU 93018 (2001) Forced convection heat transfer in straight tubes. Part 2 laminar and transitional flow. ESDU 98003-98007 (1998) Design and performance evaluation of heat exchangers the effectiveness-NTU method. 

J. Gascon, A. Oubina, B. Ballesteros, D. Barcelo, F. Camps, M.P. Marco, M.A. Gonz lez-Martmez, S. Morais, R. Puchades, and A. Maquieira, Development of a highly sensitive enzyme-linked immunosorbent assay for atrazine. Performance evaluation by flow injection immunoassay. Anal Chim. Acta 347, 149-162 (1997). 

The properties of this equation, washout, maximum production, etc. are displayed in Fig. 30.6. To find the kinetic constants Q, k and n from experiment first evaluate Cg in a batch run using an excess of reactant A and letting < . Then rearrange the mixed flow performance equation to give... 

Wu, S. T., Xia, Y. Q., and Jemal, M. (2007). High-field asymmetric waveform ion mobility spectrometry coupled with liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-FAIMS-MS/MS) multicomponent bioanalytical method development, performance evaluation and demonstration of the constancy of the compensation voltage with change of mobile phase composition or flow rate. Rapid Commun. Mass Spectrom. 21 3667-3676. 

The fluorochrome-conjugated monoclonal antibodies used may be varied. Investigation on one, a combination or all may be performed. In addition RNA Isolation to confirm the quality of RNA and Genochip Microarray for transcript profiling may be performed after flow cytometry evaluation. 

The most common test of lung function in humans is the forced exhalation test, which evaluates both lung volumes and flow performance. After inhaling maximally, the individual exhales as rapidly and deeply as possible to reach residual volume. The volumes of air exhaled per unit time and the airflow during exhalation are recorded. The forced expiratory volume measured in one second (FEVi), along... 

Light-off temperatures of oxidation catalysts are considered as one of the important parameters for catalyst performance evaluation. In this study, the in-situ FTIR technique was developed and used to determine the light-off temperatures and reaction products of three three-way automotive catalysts with 20 torr monomethylamine in air at 0.5 1/min flow rate. Light-off temperatures were found to be 140, 143, and 170°C for Davison, Allied-Signal, and Degussa oxidation catalysts, respectively. CO, CO2, 1 0, and nitric acid were found to be the major oxidation products. The activation energies of formation of CO and CO2 on the catalysts were also determined. 

PERT (Performance Evaluation Review, and Tracking) and CPM (Critical Path Method) charts (flowcharts) show the flow, connectivity, and interdependency of project tasks, activities, and goals. A PERT chart (Figure 27.9) depicts the activities in the order that they will need to be carried out, either in series or in parallel. These charts also identify which activities need to be completed (or initiated) before the next activity, which is dependent on it, can be initiated. 

Dynamic methods rely on the study of fluid flow properties of porous membranes, which are extremely sensitive funetions of the pore structural characteristics like the pore size distribution, f(r) and the pore connectivity, z. The resulting data, if analyzed in combination with other measurements obtained by equilibrium methods, can offer important structural information, regarding the membranes performance evaluation. 

The other two methods are subject to both these errors, since both the form ofi the RTD and the extent of micromixing are assumed. Their advantage is that they permit analytical solution for the conversion. In the axial-dispersion model the reactor is represented by allowing for axial diffusion in an otherwise ideal tubular-flow reactor. In this case the RTD for the actual reactor is used to calculate the best axial dififusivity for the model (Sec. 6-5), and this diffusivity is then employed to predict the conversion (Sec. 6-9). This is a good approximation for most tubular reactors with turbulent flow, since the deviations from plug-flow performance are small. In the third model the reactor is represented by a series of ideal stirred tanks of equal volume. Response data from the actual reactor are used to determine the number of tanks in series (Sec. 6-6). Then the conversion can be evaluated by the method for multiple stirred tanks in series (Sec. 6-10). 

Alternatively, low-temperature flow test (ASTM D-4539) results are indicative of the low-temperature flow performance of fuel in some diesel vehicles. This test method is especially useful for the evaluation of fuels containing flow improver additives. In this test method, the temperature of a series of test specimens of fuel is lowered at a prescribed cooling rate. At the commencing temperature and at each 1°C interval thereafter, a separate specimen from the series is Altered through a 17-mm screen until a minimum low-temperature flow test pass temperature is obtained. The minimum low-temperature flow test pass temperature is the lowest temperature, expressed as a multiple of 1°C, at which a test specimen can be Altered in 60 s or less. 

The solvent delivery system is responsible for delivering the pressurized mobile phase with the desired composition and chosen flow rate to the head of the column. To achieve this goal a number of components work together under the supervision of the system computer or microprocessors to achieve the tight specifications typical of a modem liquid chromatograph. Table 5.2 [15-19]. Suitable tests for performance evaluation of solvent delivery systems are briefly described at the end of section 5.2.2. In retention terms a relative standard deviation of better than 0.15% for retention factors under normal operating conditions is expected. 

The main value of data describing turbulent energy requirements is in the computation of pressure drop-flow rate characteristics for installed plant but there are also examples of performance evaluation using energy data -. As with laminar flow characteristics, although different, those for turbulent flow are relatively simple and easily described in terms of the friction factor-Reynolds number relationship used to describe empty tube. 

When an exchanger is new, a detailed performance evaluation is warranted and it should be repeated after 6 months or so. One should trend data in-between and afterward. Process temperatures, pressures, and flows around the heat exchanger are... 

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