Home About us Contact
|
Home About us Contact | ||
|
|
||
Performance Similar (performance + similar)
Selected AbstractsComparison of performance of heat regenerators: Relation between heat transfer efficiency and pressure dropINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2001Françoise Duprat Abstract Heat regenerators transfer heat from one gas to another, with an intermediate storage in solids. The heat transfer surface for gas flow application should provide at the same time high surface area and low friction factor. Three geometries of heat transfer surface, monolith, stack of woven screens and bed of spheres, have been compared. Their performance was evaluated from the pressure drop of the heat regenerator working at a given heat transfer efficiency. The comparison was performed using numerical simulation and published measurements of heat transfer and flow friction characteristics. By adjusting the length and the period of the exchanger, it is possible to obtain the same heat transfer efficiency with the three geometries. Beds of spheres give very short and compact heat regenerators, working at high pressure drop. At the opposite, monoliths form long regenerators working at low pressure drop. Stacks of woven screens cover a wide range of performance: low porosity woven screens give high heat transfer efficiency and high pressure drop, while high porosity woven screens offer performance similar to that of the monoliths. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effluent treatment using a bipolar electrochemical reactor with rotating cylinder electrodes of woven wire meshesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2009Javier M Grau Abstract BACKGROUND: The behaviour of a bipolar electrochemical reactor consisting of one or more rotating cylinder electrodes of woven wire meshes is reported using copper and cadmium deposition from dilute solutions as test reactions. RESULTS: The best performance related to electrode number was determined for copper deposition and was achieved by an arrangement with two bipolar electrodes, for which the conversion in a single pass was approximately 47%. The specific energy consumption was 3.27 kWh kg,1 with a normalised space velocity of 23.05 h,1. The copper powder obtained showed a nodular and dendritic surface morphology. This reactor configuration was also analysed for cadmium deposition, in which hydrogen evolution takes place simultaneously as a side cathodic reaction, considering the effect of flow rate and total current. The maximum conversion per pass for cadmium removal was 38.91%. In this case the reactor with two bipolar electrodes showed a performance similar to that of a monopolar reactor operated at a rotation speed three times higher. CONCLUSION: A continuous electrochemical reactor with two rotating bipolar electrodes of woven wire meshes presents a good performance for copper or cadmium removal from dilute solutions. Copyright © 2009 Society of Chemical Industry [source] Verb and noun generation tasks in Huntington's diseaseMOVEMENT DISORDERS, Issue 5 2004Patrice Péran MSc Abstract We compared noun- and verb-generation tasks in a demented group (n = 9, Dementia Rating Scale , 129) and in a non-demented group (n = 17, Dementia Rating Scale > 129) of Huntington's disease (HD) patients compared to 26 matched normal subjects. We did not find a specific deficit for verb production in non-demented patients who had a performance similar to but weaker than that of the controls across the four tasks. The profile of results was different in the demented group because, apart from a global deficit whatever the task in comparison with both non-demented and control groups, the demented patients exhibited increased difficulties in the two tasks implying verb production. The deficit of verb production observed in demented HD patients is discussed in relation to the damage to the motor loop in HD patients at later stages of disease. © 2003 Movement Disorder Society [source] Aldol reaction catalyzed by a hydrophilic catalyst in aqueous micelle as an enzyme mimic systemCHIRALITY, Issue 5 2009Hefeng Zhang Abstract Chitosan-supported L -proline complex was synthesized and applied as a catalyst for the direct asymmetric aldol reaction in various organic solvents and water as well. It was found that the novel synthesized catalyst was able to efficiently catalyze the aldol reaction in various media. The catalytic capacity and stereoselectivity of the catalyst were obviously improved with the introduction of aqueous micelle, possibly because the micelle functioned as a hydrophobic pocket, like the hydrophobic portion in enzymes. Moreover, the present synthetic catalyst showed performance similar to that of enzymes and could be used as a model of enzyme catalysis to help better understand the mystic mechanism of enzymes. Chirality, 2009. © 2008 Wiley-Liss, Inc. [source] MHC Class II epitope predictive algorithmsIMMUNOLOGY, Issue 3 2010Morten Nielsen Summary Major histocompatibility complex class II (MHC-II) molecules sample peptides from the extracellular space, allowing the immune system to detect the presence of foreign microbes from this compartment. To be able to predict the immune response to given pathogens, a number of methods have been developed to predict peptide,MHC binding. However, few methods other than the pioneering TEPITOPE/ProPred method have been developed for MHC-II. Despite recent progress in method development, the predictive performance for MHC-II remains significantly lower than what can be obtained for MHC-I. One reason for this is that the MHC-II molecule is open at both ends allowing binding of peptides extending out of the groove. The binding core of MHC-II-bound peptides is therefore not known a priori and the binding motif is hence not readily discernible. Recent progress has been obtained by including the flanking residues in the predictions. All attempts to make ab initio predictions based on protein structure have failed to reach predictive performances similar to those that can be obtained by data-driven methods. Thousands of different MHC-II alleles exist in humans. Recently developed pan-specific methods have been able to make reasonably accurate predictions for alleles that were not included in the training data. These methods can be used to define supertypes (clusters) of MHC-II alleles where alleles within each supertype have similar binding specificities. Furthermore, the pan-specific methods have been used to make a graphical atlas such as the MHCMotifviewer, which allows for visual comparison of specificities of different alleles. [source] A study on feeding hazelnut kernel oil meal as a protein source for broiler chickensANIMAL SCIENCE JOURNAL, Issue 3 2009Guray ERENER ABSTRACT An experiment was conducted to evaluate the effect of substituting different levels of hazelnut kernel oil meal (HKM) for soybean meal (SBM) in diets for broiler. A total of 450 one-day-old female Ross 308 broiler chicks were allocated randomly to three treatment groups of 150 birds each in a randomized design. Each treatment group consisted of five replicates each of 30 chicks. All diets (in mash form) were formulated to meet nutrient concentrations recommended for broilers. The experiment lasted for six weeks. In the experiment, an SBM control (SBM) diet was compared to two HKM diets, replacing 50 (50HKM) and 100% (HKM) of SBM protein, respectively. Body weight gain, feed intake and feed conversion ratio of broilers were adversely affected (P < 0.05) by the HKM diets at 42 days of age. Broilers fed 50HKM and HKM had growth performances similar (P > 0.05). The carcass yield and abdominal fat pads of birds fed diets with SBM were higher (P < 0.05) than those of chicks fed the 50HKM and HKM diets. The edible inner organ weight of chicks fed diets with HKM was the heaviest (P < 0.05). It is concluded that SBM cannot be replaced even up to 50% with HKM in commercial broiler diet. [source] Clinical Experiences of Computer Numeric Control-Milled Titanium Frameworks Supported by Implants in the Edentulous Jaw: A 5-Year Prospective StudyCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2004Anders Örtorp DDS ABSTRACT Background: Few long-term follow-up studies on treatment concepts using computer numeric control-milled titanium frameworks have been conducted. Objective: To evaluate the clinical and radiographic performance of implant-supported prostheses provided with computer numeric control-milled titanium frameworks in the edentulous jaw and to compare their performance during the first 5 years of function with that of prostheses provided with conventional cast gold alloy frameworks. Materials and Methods: A consecutive group of 126 edentulous patients were randomly provided with 67 prostheses with titanium frameworks (test group) in 23 upper jaws and 44 lower jaws and with 62 conventional prostheses with gold alloy castings (control group) in 31 upper jaws and 31 lower jaws. Clinical and radiographic 5-year data were collected for the test and control groups. Results: The frequency of problems was low, and clinical and radiologic performances were similar in both groups. In the test group, the 5-year cumulative survival rates (CSRs) were 94.9% and 98.3% for implants and titanium prostheses, respectively. The respective corresponding CSRs for the control group were 97.9% and 98.2%. More loaded implants were lost in the maxillas in the test group (p < .01), but this difference was not significant on the patient/prosthesis level (p > .05). Smokers lost more implants than nonsmokers lost (p < .01). Similar survival rates were observed for implants in the mandible. One prosthesis was lost in each group because of the loss of implants. Metal fractures were seen only in the control group, and resin veneer fractures were more frequent in the maxilla in the gold alloy group (p < .05). In the test group, the mean marginal bone loss was 0.5 mm (SD, 0.44) in the maxilla and 0.4 mm (SD, 0.50) in the mandible. A similar pattern of bone reaction was observed in the control group. Mean marginal bone loss was similar for smokers and nonsmokers (p > .05). Conclusion: Computer numeric control-milled titanium frameworks are a viable alternative to gold alloy castings in the edentulous jaw and present clinical and radiologic performances similar to those of conventional gold alloy frameworks during the first 5 years of function. [source] | |||||||||||||