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Optimum Combination (optimum + combination)
Selected AbstractsA Qualitative and Quantitative Approach to Determine the Optimum Combination of Feeding Stimulants for Striped Bass Morone saxatilis Using an Agar Gel CarrierJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2002Elias Papatryphon A series of experiments was conducted to determine the optimum combination of previously identified feeding stimulants (FS), namely L-alanine (Ala), L-serine (Ser), inosine-5,-monophosphate (IMP), and betaine (Bet), for striped bass Morone saxatilis. Three experiments were conducted to determine the optimum combination of FS using an agar gel matrix as a carrier. In the first experiment a 24 factorial experiment was conducted to test all possible combinations of the four FS at two levels, 0 and 0.1 M. Significant interactions between the FS were found, suggesting the complexity of gustatory stimulation and palatability. In the second experiment a 4 × 6 factorial design was employed to test each FS alone and at concentrations ranging from 0 to 8% in order to determine the minimum level at which maximal stimulation is achieved. The results suggest that there is no significant improvement in feed intake beyond the 1 % level of supplementation for all the FS. In addition, Ala produced a significantly greater response compared to all other FS. In the last experiment, a modified single factor method was used to estimate the optimum levels for each FS in a mixture. The range of the concentrations tested was 0,1% of the agar gel for each FS. Combining all four compounds yielded maximal stimulation. The levels of each compound in the final optimum combination of FS were: Ala, 0.4; Ser, 0.6; Bet, 0.4; and IMP, 0.3% of the agar gel. [source] Optimization Process of Black Soybean Natto Using Response Surface MethodologyJOURNAL OF FOOD SCIENCE, Issue 6 2009Ming-Chih Shih ABSTRACT:, Response surface methodology (RSM) was used to determine the optimum combinations of 3 factors, cooking time (40 to 120 min), inoculated bacteria populations (101 to 109 cells/100 g), and fermentation time (12 to 36 h) for producing black soybean natto. All of the responses (hardness, viscosity, and trichloacetic acid-soluble nitrogen) were significantly affected by the 3 factors. Fermentation time was the most important factor affecting quality of black soybean natto. Optimum combinations were cooking time 110 min, inoculated bacteria populations 102 to 104 cells/100 g, and fermentation time 30 to 33 h. [source] Intake, liveweight gain and feed preference by steers fed combinations of lucerne and Westerwolds ryegrass silagesGRASS & FORAGE SCIENCE, Issue 1 2002E. Charmley Nutritive value and voluntary intake of legumes are generally considered to be higher than those of grasses when ensiled at similar digestibility, although high levels of soluble protein can result in low N utilization by animals and high losses to the environment. The objectives of this experiment were to describe the optimum combination of Westerwolds ryegrass (Lolium multiflorum Lam. cv. Aubade) and lucerne (Medicago sativa L. cv. AC Caribou) silages to maximize liveweight gain of steers fed silage, determine chemical components that are important and ascertain whether steers selected the optimum mixture when given a choice. Both silages contained similar concentrations of dry matter (DM), acid-detergent fibre (ADF) and organic acids, but lucerne silage had higher concentrations of N, soluble-N and ammonia-N. Westerwolds ryegrass silage contained more neutral-detergent fibre (NDF). In a 12-week experiment, voluntary intake by Hereford steers was not influenced when the proportion of the two silages was changed from 1 to 0 in 0·25 increments. However, liveweight gain and feed efficiency increased linearly (P < 0·001) as the proportion of ryegrass silage fed was increased. When preconditioned to either of the two silages, steers showed a significant preference for ryegrass over lucerne (P < 0·05). When conditioned to a mixture of both silages, no preference was elicited. It is suggested that extensive solubilization and deamination of protein in the lucerne silage may have caused the preference for Westerwolds ryegrass silage and the higher liveweight gains on diets containing higher proportions of Westerwolds ryegrass silage. [source] Integrating genetic algorithms and spreadsheets: a capital budgeting applicationINTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 3 2006R. H. Berry The role of the tax system in generating interactions between the post-tax cash flows of different projects is discussed. When such interactions can occur, the capital budgeting process should be based around project combinations rather than individual projects. Evaluation of a project combination in net present value terms can easily be done using a spreadsheet. If the number of individual projects is large, then project combinations can be generated and an optimum combination of projects searched for using a genetic algorithm. The genetic algorithm approach has an advantage over alternative computational approaches, such as mixed integer programming, because of the more understandable representation of the problem it allows. Copyright © 2007 John Wiley & Sons, Ltd. [source] An assessment of friction factor and viscosity correlations for model prediction of refrigerant flow in capillary tubesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2005Zhang Yufeng Abstract In this paper, a homogeneous model including the metastable liquid and metastable two-phase region is presented to assess the effects of various friction factor equations and two-phase viscosity correlations on simulating the behaviour of capillary tubes. Both straight and coiled capillary tubes are considered and R-22 is used for comparison. The predicted pressure distribution, tube lengths or mass flow rates are compared with experimental data reported in literature. It is confirmed that the predicting accuracy with homogeneous model can be improved by employing the suitable correlations of friction factor and two-phase viscosity. For straight capillaries, the Churchill and Colebrook friction factor correlations give almost the same simulating results. However, the numerical results show that the optimum combination of correlations of friction factor and two-phase viscosity may be different when compared with different experimental data. For coiled capillaries, the Mori and Nakayama friction factor correlation agrees well with Ito's formula for single liquid-phase flow. Together with Giri's friction factor equation for two-phase flow, Cicchitti viscosity model best predicts the measured mass flow rate with an average error of 4.88%. Copyright © 2004 John Wiley & Sons, Ltd. [source] Selective Hydrogenation of Amides using Ruthenium/ Molybdenum CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2010Graham Beamson Abstract Recyclable, heterogeneous bimetallic ruthenium/molybdenum catalysts, formed in situ from triruthenium dodecacarbonyl [Ru3(CO)12] and molybdenum hexacarbonyl [Mo(CO)6], are effective for the selective liquid phase hydrogenation of cyclohexylcarboxamide (CyCONH2) to cyclohexanemethylamine (CyCH2NH2), with no secondary or tertiary amine by-product formation. Variation of Mo:Ru composition reveals both synergistic and poisoning effects, with the optimum combination of conversion and selectivity at ca. 0.5, and total inhibition of catalysis evident at ,1. Good amide conversions are noted within the reaction condition regimes 20,100,bar hydrogen and 145,160,°C. The order of reactivity of these catalysts towards reduction of different amide functional groups is primary>tertiary,secondary. In situ HP-FT-IR spectroscopy confirms that catalyst genesis occurs during an induction period associated with decomposition of the organometallic precursors. Ex situ characterisation, using XRD, XPS and EDX-STEM, for active Mo:Ru compositions, has provided evidence for intimately mixed ca. 2.5,4,nm particles that contain metallic ruthenium, and molybdenum (in several oxidation states, including zero). [source] Effective assessment of use of sitters by nurses in inpatient care settingsJOURNAL OF ADVANCED NURSING, Issue 2 2008Huey-Ming Tzeng Abstract Title.,Effective assessment of use of sitters by nurses in inpatient care settings Aim., This paper is a report of the evaluation of the impact of adopting the Patient Attendant Assessment Tool (PAAT) on nurses' requests for sitters, use of restraints, and falls and fall injury rates. Background., Staffing should be the primary issue in eliminating risks of patient falls during hospital stays. Method., Data were collected in two acute adult medical units of a Michigan hospital from August 2005 to February 2007. Data from three sources were merged for analyses: (1) study units' monthly reports; (2) quarterly reports of the National Database of Nursing Quality Indicators and (3) PAAT reports collected from October 2006 to February 2007. The primary outcome variables were the use of sitters, number of restraints ordered and fall and fall injury rates. Independent t -tests and correlation analyses were used for data analyses. The data before and after adopting this tool were compared using independent t -tests. Findings., The PAAT helped improve the fill/request rates for sitters. The use of soft limb holders decreased after adoption of this tool. The results also showed that if the number of sitter requests was higher, the total number of restraints would be lower but the total fall rate would be higher. Conclusion., Hospitals should include a tool similar to the PAAT in guidelines related to provision of constant observation or use of sitters. Further investigations of the optimum combination of staffing patterns and infrastructure are needed to promote safer hospital stays. [source] A study of antifungal antibiotic production by Thermomonospora sp MTCC 3340 using full factorial designJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2003Monali Gupte Abstract The three independent variables, viz concentration of carbon source (glucose), concentration of nitrogen source (soybean meal) and temperature of incubation were found to be the most important for production of antifungal antibiotic by the isolate Thermomonospora sp MTCC 3340 from one-factor-at-a-time study. These variables were varied at three levels in a total number of 27 experiments designed using full factorial design. The results on analysis using the statistical software SPSS (version 6.0) indicated that the optimum combination of the three factors for the maximum yield of the antibiotic was concentration of carbon source (glucose) 2%, concentration of nitrogen source (soybean meal) 1% and temperature of incubation 30 °C. A close fit between experimental and predicted values of the antifungal yield was obtained using one of the modes derived from the statistical analysis, indicating that this model was applicable to this production. Copyright © 2003 Society of Chemical Industry [source] Design of a two-step pulsed pressure-swing adsorption-based oxygen concentratorAICHE JOURNAL, Issue 2 2010V. Rama Rao Abstract A two-step pulsed pressure-swing adsorption (PPSA) process has been modeled to assess the extent to which an oxygen concentrator might be miniaturized for medical applications. The process consists of a single bed of packed adsorbent particles that is alternately pressurized and depressurized at the feed end. An enriched oxygen product is withdrawn at ambient pressure from the product end when the bed is pressurized at the feed end. The product end remains closed during depressurization. The model development addresses the manner in which axial dispersion enters into the describing equations and the formulation of proper boundary conditions, both of which have not been handled rigorously in some prior modeling studies. The describing equations are solved using COMSOL® Multiphysics software. The effect on the performance of the adsorption time, desorption time, bed length, particle diameter, and imposed pressure drop across the bed have been investigated. An interesting novel result is that for a chosen particle size, bed length, and applied pressure drop, there is an optimum combination of adsorption and desorption times that maximizes the product purity. The results suggest that there are operating windows for both 5A and partially Ag-exchanged Li-substituted 13X zeolite adsorbents wherein the product oxygen purity is greater than 90%. At a given product flow rate within this operating window, the extent of miniaturization is limited by the (maximum) cycling frequency that is practically achievable. Sizing of an oxygen concentrator for personal medical applications is also discussed. A principal conclusion is that a compact oxygen concentrator capable of producing a highly oxygen-enriched product is possible using commercially available adsorbents and implementable operating conditions. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] A Qualitative and Quantitative Approach to Determine the Optimum Combination of Feeding Stimulants for Striped Bass Morone saxatilis Using an Agar Gel CarrierJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2002Elias Papatryphon A series of experiments was conducted to determine the optimum combination of previously identified feeding stimulants (FS), namely L-alanine (Ala), L-serine (Ser), inosine-5,-monophosphate (IMP), and betaine (Bet), for striped bass Morone saxatilis. Three experiments were conducted to determine the optimum combination of FS using an agar gel matrix as a carrier. In the first experiment a 24 factorial experiment was conducted to test all possible combinations of the four FS at two levels, 0 and 0.1 M. Significant interactions between the FS were found, suggesting the complexity of gustatory stimulation and palatability. In the second experiment a 4 × 6 factorial design was employed to test each FS alone and at concentrations ranging from 0 to 8% in order to determine the minimum level at which maximal stimulation is achieved. The results suggest that there is no significant improvement in feed intake beyond the 1 % level of supplementation for all the FS. In addition, Ala produced a significantly greater response compared to all other FS. In the last experiment, a modified single factor method was used to estimate the optimum levels for each FS in a mixture. The range of the concentrations tested was 0,1% of the agar gel for each FS. Combining all four compounds yielded maximal stimulation. The levels of each compound in the final optimum combination of FS were: Ala, 0.4; Ser, 0.6; Bet, 0.4; and IMP, 0.3% of the agar gel. [source] Effects of stochastic parametrizations in the Lorenz '96 systemTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 606 2005Daniel S. Wilks Abstract Stochastic parametrization of the effects of unresolved variables is studied in the context of the Lorenz '96 system. These parametrizations are found to produce clear improvements in correspondence between the model and ,true' climatologies; they similarly provide clear improvements in all ensemble forecast verification measures investigated, including accuracy of ensemble means and ensemble probability estimation, and including measures operating on both scalar (each resolved forecast variable evaluated individually) and vector (all forecast variables evaluated simultaneously) predictands. Scalar accuracy measures for non-ensemble (i.e. single integration) forecasts are, however, degraded. The results depend very strongly on both the amplitude (standard deviation) and time-scale of the stochastic forcing, but only weakly on its spatial scale. In general there seems not to be a single clear optimum combination of time-scale and amplitude, but rather there exists a range of combinations producing similar results. Copyright © 2005 Royal Meteorological Society. [source] Mapping tree species in temperate deciduous woodland using time-series multi-spectral dataAPPLIED VEGETATION SCIENCE, Issue 1 2010R. A. Hill Abstract Questions: What is the optimum combination of image dates across a growing season for tree species differentiation in multi-spectral data and how does species composition affect overstorey canopy density? Location: Monks Wood, Cambridgeshire, eastern England, UK. Methods: Six overstorey tree species were mapped using five Airborne Thematic Mapper images acquired across the 2003 growing season (17 March, 30 May, 16 July, 23 September, 27 October). After image pre-processing, supervised maximum likelihood classification was performed on the images and on all two-, three-, four- and five-date combinations. Relationships between tree species composition and canopy density were assessed using regression analyses. Results: The image with the greatest tree species discrimination was acquired on 27/10 when the overstorey species were in different stages of leaf tinting and fall. In this image, tree species were mapped with an overall classification accuracy (OCA) of 71% (kappa 0.63). A similar OCA was achieved from the other four images combined (OCA 72%, kappa 0.64). The highest classification accuracy was achieved by combining three images: 17 March, 16 July, 27 October. This achieved an OCA of 84% (kappa 0.79), increasing to 88% (kappa 0.85) after a post-classification clump and sieve procedure. Canopy height and percentage cover of oak explained 72% of variance in canopy density. Conclusions: The ability to discriminate and map temperate deciduous tree species in airborne multi-spectral imagery is increased using time-series data. An autumn image supplemented with an image from both the green-up and full-leaf phases was optimum. The derived tree species map provides a more powerful ecological tool for determining woodland structural/compositional relationships than field-based measures. [source] The interdependence of wavelength, redundancy and dose in sulfur SAD experimentsACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2008Michele Cianci In the last decade, the popularity of sulfur SAD anomalous dispersion experiments has spread rapidly among synchrotron users as a quick and streamlined way of solving the phase problem in macromolecular crystallography. On beamline 10 at SRS (Daresbury Laboratory, UK), a versatile design has allowed test data sets to be collected at six wavelengths between 0.979 and 2.290,Å in order to evaluate the importance and the interdependence of experimental variables such as the Bijvoet ratio, wavelength, resolution limit, data redundancy and absorbed X-ray dose in the sample per data set. All the samples used in the experiments were high-quality hen egg-white lysozyme crystals. X-radiation damage was found to affect disulfide bridges after the crystals had been given a total dose of 0.20 × 107,Gy. However, with such a total dose, it was still possible in all cases to find a strategy to collect data sets to determine the sulfur substructure and produce good-quality phases by choosing an optimum combination of wavelength, exposure time and redundancy. A ,|,ano|/,(,ano), greater than 1.5 for all resolution shells was a necessary requirement for successful sulfur SAD substructure location. Provided this is achieved, it seems possible to find an optimum compromise between wavelength, redundancy and dose to provide phasing information. The choice of the wavelength should then follow the sample composition and the diffracting properties of the crystal. For strongly diffracting crystals, wavelengths equal or shorter than 1.540,Å can be selected to capture the available data (provided the Bijvoet ratio is reasonable), while a longer wavelength, to gain as high a Bijvoet ratio as possible, must be used for more weakly diffracting crystals. These results suggest that an approach to a sulfur SAD experiment based on a complete description of the crystal system and the instrument for data collection is useful. [source] From Time Temperature Integrator Kinetics to Time Temperature Integrator Tolerance Levels: Heat-Treated MilkBIOTECHNOLOGY PROGRESS, Issue 1 2004Wendie L. Claeys Six milk compounds were studied as potential intrinsic time temperature integrators (TTIs) for the assessment of heat-treated milk. These include the enzymes alkaline phosphatase and lactoperoxidase, the whey protein ,-lactoglobulin and the chemical compounds hydroxymethylfurfural, lactulose and furosine. In previous research the inactivation/denaturation/formation kinetics of these compounds were analyzed under isothermal and nonisothermal conditions and evaluated for variability of the milk composition. The present paper focuses on the implementation of the TTIs. TTIs are validated with respect to microbiological indices and quality attributes, and a quantitative relationship between the denaturation, inactivation or formation of the TTIs and technological processes is established by construction of general time temperature tolerance (TTT) diagrams. In these diagrams temperature time combinations are presented, which lead to the same formation, inactivation or denaturation of TTIs, or result in the same level of microbiological destruction or quality degradation of the product. TTT-diagrams are very informative since they allow visualization of the impact of a thermal process on milk and evaluation of criteria for evaluating milk authenticity (conformity of the product with the terminology applied). Moreover, the optimum combination of temperature and time of heating may be readily deduced from these diagrams. [source] Optimization Process of Black Soybean Natto Using Response Surface MethodologyJOURNAL OF FOOD SCIENCE, Issue 6 2009Ming-Chih Shih ABSTRACT:, Response surface methodology (RSM) was used to determine the optimum combinations of 3 factors, cooking time (40 to 120 min), inoculated bacteria populations (101 to 109 cells/100 g), and fermentation time (12 to 36 h) for producing black soybean natto. All of the responses (hardness, viscosity, and trichloacetic acid-soluble nitrogen) were significantly affected by the 3 factors. Fermentation time was the most important factor affecting quality of black soybean natto. Optimum combinations were cooking time 110 min, inoculated bacteria populations 102 to 104 cells/100 g, and fermentation time 30 to 33 h. [source] Effect of combined photoperiod, water calcium concentration and pH on survival, growth, and moulting of juvenile crayfish (Procambarus clarkii ) cultured under laboratory conditionsAQUACULTURE RESEARCH, Issue 11 2009Cai-Feng Yue Abstract The red swamp crayfish, Procambarus clarkii (Girard), is one of the most commonly farmed freshwater species in inland China due to its high market value and consumer demand. The aim of this study was to determine the optimum combinations of photoperiod, water calcium concentration and pH for juvenile survival, growth and moulting. In our orthogonal experiment, the three environmental factors were varied at three levels (photoperiod: 16L:8D, 12L:12D and 8L:16D; calcium concentration: 45.5, 65.5 and 85.5 mg L,1; and pH: 6.8, 7.8 and 8.8). Range analysis showed that the maximum survival of juvenile crayfish occurred at photoperiods of 16L:8D or 8L:16D, water calcium concentration of 45.5 mg L,1 and pH of 7.8; maximum weight gain at photoperiod 16L:8D, water calcium concentration 65.5 mg L,1 and pH 7.8; maximum length increase at photoperiod 16L:8D, water calcium concentration 65.5 mg L,1 and pH 7.8; and the highest moult frequency at photoperiod 12L:12D, water calcium concentration 65.5 mg L,1 and pH 7.8. Analysis of variance indicated that photoperiod, water calcium concentration and pH significantly influenced only the weight gain of juvenile crayfish (P<0.05). Taking growth into consideration, we suggest that a photoperiod of 16L:8D, calcium concentration of 65.5 mg L,1 and pH 7.8 might be optimal conditions for rearing juvenile P. clarkii. [source] | |||||||||||||