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Optimization Study (optimization + study)
Selected AbstractsOptimization Study of ICRF Heating in the LHD and HSX ConfigurationsCONTRIBUTIONS TO PLASMA PHYSICS, Issue 6-7 2010S. Murakami Abstract Two global simulation codes, TASK/WM (a full wave solver) and GNET (a 5-D drift kinetic equation solver), are combined to simulate the ICRF heating in the 3D magnetic configuration. The combined code is applied to the ICRF minority heating in the LHD configuration. An optimization of the ICRF heating is considered in changing the magnetic configurations and the resonance surfaces in the LHD plasmas using GNET code. It is found that the heating efficiency is improved about 30% with the heating power of 10MW in the optimized heating scenario from that of the present standard off-axis heating scenario. Also the ICRF minority heating is studied in the HSX plasma and it is found that the ICRF heating of about 100kW is still effective to heat the plasma even , /a , 1/7.5 for tail ions (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plantsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 12 2010K. M. Mohamed Abstract This study evaluates large-scale low-grade energy recovery (LS-LGER) from a conventional coal-fired Rankine cycle (RC) as a ,green' option to offsetting the cost of treating pollution. An energy and exergy analysis of a reference generating station isolates the key areas for investigation into LS-LGER. This is followed by a second law analysis and a detailed optimization study for a revised RC configuration, which provides a conservative estimate of the possible energy recovery. Cycle optimization based on specific power output, and including compact heat exchanger designs, indicates plant efficiency improvements (with high-capacity equipment) of approximately 2 percentage points with reduced environmental impact. Copyright © 2009 John Wiley & Sons, Ltd. [source] Kinetic Analysis and Optimization for the Catalytic Esterification Step of PPT PolymerizationMACROMOLECULAR THEORY AND SIMULATIONS, Issue 1 2005Saptarshi Majumdar Abstract Summary: A well-validated kinetic scheme has been studied for PPT, poly(propylene terephthalate) polymerization process in batch and semi-batch mode with tetrabutoxytitanium (TBOT), a proven catalyst. Optimization study and analysis for PPT are rare, as the industrial relevance of PPT just became vibrant due to the commercial availability of one of its monomers in industrial scale in the recent past. Correctness of the analysis is checked by a new approach and parameters for the model are estimated from available experimental data. Solubility of terephthalic acid (TPA) is less in reaction medium and this effect is also considered along with the reaction scheme. Several simulations have been performed to see various process dynamics and this ultimately helps in formulating optimization problems. Using recently developed and well tested real-coded non-dominated sorting genetic algorithm-II, a state-of-the art evolutionary optimization algorithm, a couple of three objective optimization problems have been solved and corresponding Pareto sets are presented. Results show remarkably promising aspects of productivity enhancement with an improvement in product quality. Sensitivity analysis for relatively uncertain solubility parameter is also performed to estimate its effect over the proposed optimal solutions. Multiobjective Pareto front for 3 objectives: degree of polymerization, time and (bTPA,+,bPG). [source] Optimization of chromatic dispersion measurement technique using relative power of two beating frequenciesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2006H. A. Abdul-Rashid Abstract Optimization study of the Chromatic Dispersion measurement technique using relative power of two beating frequencies is presented in this paper. The performance of the CD measurement technique is studied in terms of the measurement range and sensitivity as the wavelength separation is varied. Based on the mathematical model and experimental results the technique sensitivity increases with wavelength separation. However, this increase in sensitivity is traded off with narrower measurement range. The measurement technique is optimized at 5.0 GHz wavelength separation with sensitivity of 0.009 (dB/ps/nm) and measurement range of 2500 (ps/nm). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2154,2156, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21893 [source] Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plantsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 12 2010K. M. Mohamed Abstract This study evaluates large-scale low-grade energy recovery (LS-LGER) from a conventional coal-fired Rankine cycle (RC) as a ,green' option to offsetting the cost of treating pollution. An energy and exergy analysis of a reference generating station isolates the key areas for investigation into LS-LGER. This is followed by a second law analysis and a detailed optimization study for a revised RC configuration, which provides a conservative estimate of the possible energy recovery. Cycle optimization based on specific power output, and including compact heat exchanger designs, indicates plant efficiency improvements (with high-capacity equipment) of approximately 2 percentage points with reduced environmental impact. Copyright © 2009 John Wiley & Sons, Ltd. [source] INFLUENCE OF SODIUM TRIPOLYPHOSPHATE (STP) TREATMENT AND COOKING TIME ON COOK LOSSES AND TEXTURAL PROPERTIES OF RED MEATSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2007S. BELGIN ERDOGDU ABSTRACT Sodium tripolyphosphates (STPs) are important functional additives used in meat products. STPs reduce cook losses and improve textural properties, especially by increasing the water-holding capacity of proteins. However, increases in cooking time or temperature enhance meat proteins' denaturation, resulting in a reduced water-holding capacity. The amount of STPs diffused into meats would play an important role for these changes. Therefore, the objectives of this research were to determine the effects of processing conditions (cooking time, STP concentration and dipping time) on cook losses and textural properties of red meats, and to relate these changes with diffused amount of STPs. For this purpose, meats (2 × 2 × 2 cm in size) were dipped in different concentrations of STP solutions (2, 4 and 6%) for 10, 20 and 30 min, and were cooked in boiling water for 5, 10 and 15 min. Cook losses were calculated from weight changes, and textural properties were determined by applying texture profile analysis to data obtained using Texture Analyzer TA-XT2i (Stable Micro Systems, Godalming, Surrey, U.K.). STPs were found to decrease cook losses and hardness values. While an increase in STP concentration increased cohesiveness, increase in cooking time resulted in higher hardness, gumminess, chewiness and cook losses. An increase in dipping times also decreased the cook losses and hardness. The results showed that STP concentration, STP dipping and cooking times had significant effects on the changes of textural properties and cook losses of meats. These results may be used for further meat processing optimization studies if they get correlated with sensory data obtained at the same conditions. PRACTICAL APPLICATIONS Cooking to assure safety of food products leads to changes in sensory attributes. The major changes occurring in meats are shrinkage, toughening of tissues, releasing of meat juice and color due to the effect of thermal treatment on proteins. Based on these, resulting cook losses for economical considerations and changes in textural properties affecting consumer satisfaction are widely recognized. Because the meat processing industry uses sodium tripolyphosphates (STPs) to improve textural properties and to reduce cook losses, the objective of this research was to determine the effects of STPs and cooking time on cook losses and textural properties of red meats. The results showed that STPs and cooking time affected the changes in cook losses and textural properties significantly. In addition to these results, an optimization study for decreasing cook losses while improving textural properties should be conducted where these changes are attributed to be significant for human perception using a sensory panel. [source] Assessment of the Automobile Assembly Paint Process for Energy, Environmental, and Economic ImprovementJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1-2 2004Geoffrey J. Roelant A coat of paint adds considerable value to an automobile. In addition to consuming up to 60% of the energy needed by automobile assembly plants, however, the painting process also creates both economic and environmental impacts. This study investigated the degree of cost and environmental impact improvement that can be expected when modifications are considered for existing paint processes through heat integration. In order to accomplish this goal, a mathematical model was created to describe the energy use, costs, and environmental impacts from energy consumption in an automobile assembly painting facility. The model agrees with measured energy consumption data for process heating and electricity demand to within about 15% for one Michigan truck facility from which model input parameters were obtained. Thermal pinch analysis determined an energy conservation target of 58% of paint process energy demand. A heat exchanger network optimization study was conducted in order to determine how closely the network design could achieve this target. The resulting heat exchanger network design was profitable based on a discounted cash flow analysis and may achieve reductions in total corporate energy consumption of up to 16% if implemented corporatewide at a major automobile manufacturer. [source] Numerical optimization study of multiple-pass aeroassisted orbital transferOPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 4 2002Anil V. Rao Abstract A direct transcription method is applied to the problem of multiple-pass aeroassisted orbital transfer from geostationary orbit to low Earth orbit with a large inclination change. The objective is to provide minimum-impulse requirements and corresponding optimal trajectories for a gliding vehicle with a high lift-to-drag ratio subject to constraints on heating rate, angle of attack, and transfer time. The multiple-pass aeroassisted orbital transfer problem is set up as a multi-phase optimal control problem. All relevant parameters, including de-orbiting, intermediate, and circularizing impulses, are optimized. Copyright © 2002 John Wiley & Sons, Ltd. [source] Injection molded composites of short Alfa fibers and biodegradable blendsPOLYMER COMPOSITES, Issue 4 2006I. Ammar Fully biodegradable composites made from two polymer blend matrices (SEVA-C: starch and a copolymer of ethylene vinyl alcohol; and SCA: starch and cellulose acetate) and short Alfa fibers were developed and processed by conventional injection molding into standard tensile specimens. For each kind of matrix, the influence of the reinforcement load was evaluated, using fiber amounts from 0 to 30% (wt/wt). An optimization study was carried out for the composite SEVA-C with 10% Alfa fiber. The obtained results establish that the produced biodegradable composites present a significant improvement in stiffness for both matrices. Improvements in the tensile strength were observed only for the Alfa fiber reinforced SEVA-C. However, for both matrices, the reinforcement causes a significant loss in the material ductility. Results from design of experiments (Hadamard plans) were used to explain the influence of the injection molding conditions on the mechanical behavior of the obtained composites, mainly on the stiffness values. POLYM. COMPOS., 27:341,348, 2006. © 2006 Society of Plastics Engineers [source] High-quality surface passivation of silicon solar cells in an industrial-type inline plasma silicon nitride deposition systemPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2004Jens D. Moschner Abstract We have studied the surface passivation of silicon by deposition of silicon nitride (SiN) in an industrial-type inline plasma-enhanced chemical vapor deposition (PECVD) reactor designed for the continuous coating of silicon solar cells with high throughput. An optimization study for the passivation of low-resistivity p -type silicon has been performed exploring the dependence of the film quality on key deposition parameters of the system. With the optimized films, excellent passivation properties have been obtained, both on undiffused p -type silicon and on phosphorus-diffused n+ emitters. Using a simple design, solar cells with conversion efficiencies above 20% have been fabricated to prove the efficacy of the inline PECVD SiN. The passivation properties of the films are on a par with those of high-quality films prepared in small-area laboratory PECVD reactors. Copyright © 2004 John Wiley & Sons, Ltd. [source] Implantation of ethylene vinyl alcohol copolymer for faecal incontinence managementANZ JOURNAL OF SURGERY, Issue 5 2010Jacqueline H. Stephens Abstract Purpose:, The primary objectives of this trial were to evaluate the safety and feasibility of treatment and to gain a preliminary indication of the effectiveness of ethylene vinyl alcohol injections into the anal sphincters of faecally incontinent patients. Methods:, Between April 2004 and February 2006, we conducted a prospective, single-arm, procedure optimization study of ethylene vinyl alcohol injections in 21 subjects with well-characterized faecal incontinence and an intact external anal sphincter at two Australian hospitals. Results:, There was a significant decrease in the Cleveland Clinic Florida Faecal Incontinence Score (CCFFIS) (P= 0.0005) and the Faecal Incontinence Severity Index score (P= 0.005) after treatment. At 12 months post-treatment, the mean CCFFIS had decreased by 37% (P= 0.0021), and 47% of subjects had a ,50% improvement in CCFFIS. There were significant improvements in embarrassment (P= 0.0455) and coping/behaviour (P= 0.0056) domains of the Faecal Incontinence Quality of Life. At 12 months, the mean anal canal length had increased by 29% (P= 0.066), with 40% of patients demonstrating increases of 50% or more. There were no further improvements following retreatment. Conclusions:, Ethylene vinyl alcohol injection into the anal intersphincteric plane is feasible and well tolerated. Improvement in faecal incontinence compared with baseline was seen. Retreating initial non-responders was not successful. [source] | |||||||||||||