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Performance Parameters (performance + parameter)
Selected AbstractsAn Octyl-2-Cyanoacrylate Formulation Speeds Healing of Partial-Thickness WoundsDERMATOLOGIC SURGERY, Issue 9 2001Stephen C. Davis BS Background. Occlusive dressings have been known to accelerate the rate of healing. Every year new dressings are being introduced in the marketplace. Objective. The purpose of this study was to evaluate the effect of a new octyl-2-cyanoacrylate liquid dressing as compared to two over-the-counter bandages on partial-thickness wounds. Performance parameters were epithelialization, erythema, scab formation, material adherence, hemostasis, and infection. Method. Eight pigs with a total of 645 partial-thickness wounds were assigned to one of the following treatments: liquid dressing, standard bandage, hydrocolloid bandage, or untreated air exposed. Result. The liquid bandage enhanced the rate of epithelialization and was the only treatment to provide complete hemostasis, reduced scab formation, and did not induce an irritant response (erythema) or infection. Conclusion The liquid bandage is an easy to use material that stops bleeding (instantaneous hemostasis) while enhancing healing of partial-thickness wounds. [source] Defining and maximizing PPT,a novel performance parameter for IEEE 802.11 DCFINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2006Yun Li Abstract Much research has been conducted on saturation throughput of IEEE802.11 DCF, and has led to some improvement. But increasing the successful transmission probability of packet is also important for saving stations' battery energy and decreasing the packet delay. In this paper, we define a new performance parameter, named Product of successful transmission Probability and saturation Throughput (PPT), for 802.11 DCF, which binds successful transmission probability and saturation throughput together. An analysis is given to maximize PPT. An expression of optimal minimum contention windows (CWmin) is obtained analytically for maximizing PPT. For simplicity, we give a name DCF-PPT to the 802.11 DCF that sets its CWmin according to this expression. The performance of DCF-PPT is simulated with different stations in terms of saturation throughput, successful transmission probability and PPT. The simulation results indicate that, compared to 802.11 DCF, DCF-PPT can significantly increase the PPT and successful transmission probability (about 0.95) on condition that the saturation throughput is not decreased. Copyright © 2006 John Wiley & Sons, Ltd. [source] Design and analysis of a scalable algorithm to monitor chord-based p2p systems at runtimeCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2008Andreas Binzenhöfer Abstract Peer-to-peer (p2p) systems are a highly decentralized, fault tolerant, and cost-effective alternative to the classic client,server architecture. Yet companies hesitate to use p2p algorithms to build new applications. Due to the decentralized nature of such a p2p system the carrier does not know anything about the current size, performance, and stability of its application. In this paper, we present an entirely distributed and scalable algorithm to monitor a running p2p network. The snapshot of the system enables a telecommunication carrier to gather information about the current performance parameters of the running system as well as to react to discovered errors. Copyright © 2007 John Wiley & Sons, Ltd. [source] Left Ventricular Function in Male Patients with Secondary HypogonadismECHOCARDIOGRAPHY, Issue 3 2007Oben Baysan M.D. Background: In addition to the effects on ventricular repolarization, testosterone could also affect left ventricular performance. The enhancement of left ventricular contractility in testosterone-deficient rats following testosterone replacement implies to the possible testosterone effect. Objectives: The aim of the current study is to reveal the alterations of left ventricular functions, if any, in secondary hypogonadal male patients. Methods: Thirty-four males with secondary hypogonadism comprised the study group. The control group consisted of 30 healthy subjects. Echocardiographic measurements including left ventricular dimensions, ejection fraction, mitral inflow, and left ventricular outflow parameters were obtained from all subjects. Tissue Doppler parameters were also measured from left ventricular lateral wall and interventricular septum. Results: Left ventricular diameters, wall thicknesses, and performance parameters were similar in both groups. Mitral inflow parameters showed a statistically insignificant difference. Pulse-wave tissue Doppler interpretation of hypogonadal and healthy subjects were similar in terms of lateral and septal basal segment Sm, Em, and Am wave velocities. Conclusions: Regarding the findings of previous studies that showed impaired myocardial contractility and lusitropy in testosterone deficient rats and our study results, further studies are needed for better understanding of testosterone's effects on human myocardium. [source] Enantioselective analysis of pheniramine in urine by charged CD-mediated CZE provided with a fiber-based DAD and an on-line sample pretreatment by capillary ITPELECTROPHORESIS, Issue 15 2007Jozef Marák Abstract Application potentialities of CZE on-line coupled with capillary ITP and DAD to the identification and determination of trace concentration levels (,g/L) of pheniramine (PHM) enantiomers and their metabolites present in complex ionic matrices of biological origin (urine) are shown. An enhanced (enantio)selectivity of the CZE separation system obtained by the addition of carboxyethyl-,-CD (CE-,-CD) to the carrier electrolyte provided CZE conditions for a reliable identification of similar/identical DAD spectra of structurally related compounds (PHM enantiomers and their metabolites) in clinical urine samples differing in qualitative and quantitative composition of sample matrix constituents. A high sample loadability (a 30,,L sample injection volume), partial sample clean-up (removing macroconstituents from the sample), and preconcentration of the analytes in ITP stage resulted in the decrease of concentration LOD for PHM enantiomers in urine to 5.2 and 6.8,,g/L (2.2×10,8 and 2.8×10,8,mol/L), without using any sample pretreatment technique. The background correction and smoothing procedure applied to the raw DAD spectra provided analytically relevant DAD spectra of PHM enantiomers and their metabolites also when they were present in urine sample (30,,L injection volumes of ten-times diluted urine sample) at a 9×10,8,mol/L concentration. DAD spectra of PHM enantiomers present in urine samples matched their reference spectra with reasonable certainties. DAD spectra of PHM metabolites were compared with the reference spectra of PHM enantiomers and a good match was found which indicates the similarities in the structures of enantiomers and their metabolites detected in the urine samples. This fact allows performing the quantitative analyses of PHM metabolites in the urine samples by applying the calibration parameters of PHM enantiomers also for PHM metabolites and the results show the possibilities of using the ITP,CZE,DAD combination for the direct analysis of PHM enantiomers and/or their metabolites in urine without any sample pretreatment. ITP,CZE,DAD method with oppositely charged selector is suggested to use in clinical research as it provides favorable performance parameters including sensitivity, linearity, precision, recovery, and robustness with minimal demands on sample preparation. [source] Construction of an antibody microarray based on agarose-coated slidesELECTROPHORESIS, Issue 3 2007Lin-Li Lv Abstract The antibody microarray, a high-throughput multiplex immunoassay method, has become a significant tool for quantitative proteomics studies. We describe here the strategies for optimizing the condition of antibody microarray building based on agarose-coated slides. In this study, modified glass slides were robotically printed with capture antibodies against monocyte chemoattractant protein 1 (MCP-1), then dilutions of the cytokine were applied to the arrays, and the protein was detected with biotin-labeled antibody coupled with Cy3-conjugated streptavidin. Thus a protein profiling microarray based on sandwich immunoassay has been established. Various factors in the production of antibody microarrays were analyzed: the capture antibody concentrations, shelf life of the postprinting slides, blocking buffers, and reproducibility of the system. A calibration curve with a correlation coefficient of 0.9995 was established which suggested that the matrix can retain arrayed proteins in near-quantitative fashion. The results revealed high signal uniformity and reproducibility with regard to intra-array (1.3%) and the interarray (8.7%) variation at the capture antibody concentration of 125,µg/mL. Besides, the printed arrays could be stored for at least two months without any apparent change of the performance parameters. [source] Fate of estrogens and xenoestrogens in four sewage treatment plants with different technologies,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2008Guang-Guo Ying Abstract The fate and removal of the estrogens 17,-estradiol (E2), estrone (E1), and 17,-ethynylestradiol (EE2) and of the xenoestrogens bisphenol A (BPA), 4- tert -octylphenol (4- t -OP), 4-nonylphenol (4-NP), and nonylphenol mono- and diethoxylate (NPEO1 and NPEO2, respectively) were investigated in four South Australian sewage treatment plants (STPs; plants A,D) with different treatment technologies. The concentrations in the effluent from the two-year survey were similar to those reported in other studies. In the effluent, 4-NP, NPEO1, and NPEO2 had total concentrations up to 8 ,g/L, which were much higher than those of BPA and 4-t-OP. Estrone had the highest concentrations among the three estrogens, ranging between 13.3 and 39.3 ng/L, whereas the concentrations for E2 and EE2 varied between 1.0 and 4.2 ng/L and between 0.1 and 1.3 ng/L, respectively. The removal rates for the estrogens and xenoestrogens were variable but consistent with the plant performance parameters (biochemical oxygen demand, suspended solids, and ammonia). Considering all the estrogenic compounds analyzed in the present study, plant D, with a series of anaerobic and aerobic lagoons, was the least efficient of the four STPs in the removal of these compounds. The removal rates for 4-NP, NPEO1, and NPEO2 within the plants were 92% for plant A, with conventional activated sludge treatment; 80% for plant B, with two oxidation ditches; 70% for plant C, with three bioreactors; and 64% for plant D, with 10 lagoons in series. Comparatively, the removal of estrogens was lower, with rates ranging between 47 and 68% for E2 at the four plants. Both E1 and EE2 were more persistent during treatment, especially in plants C and D. [source] European classes for the reaction to fire performance of wood-based panelsFIRE AND MATERIALS, Issue 6 2010Birgit A.-L. Östman Abstract The classification system for the reaction to fire performance of building products in Europe has been applied to wood-based panels as being ,products with known and stable fire performance'. The European classification system includes two sub-systems, one main system for all construction products except floorings and the other for flooring products. Panel properties such as density, thickness, joints and types of end-use application including different substrates have been studied thoroughly and are included in the classification. Most wood-based panels fall in classes D-s2, d0 or Dfl -s1 (for floorings). Testing has been performed according to EN 13823 SBI-Single Burning Item test, EN ISO 9239-1 Radiant panel test, and EN ISO 11925-2 Small flame test. Clear relationships between the main Euroclass fire performance parameters and product parameters (such as density and thickness) have been demonstrated. Tables with reaction to fire classification of different wood-based panels and end-use applications have been developed in two steps, approved by the European Commission and published in their Official Journal. The table is also included in the harmonized product standard and may be used for CE-marking. Copyright © 2010 John Wiley & Sons, Ltd. [source] Single Miller capacitor frequency compensation with nulling resistor for three-stage amplifiersINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 7 2008S. O. Cannizzaro Abstract A frequency compensation technique for three-stage amplifiers is introduced. The proposed solution exploits only one Miller capacitor and a resistor in the compensation network. The straightness of the technique is used to design, using a standard CMOS 0.35-µm process, a 1.5-V OTA driving a 150-pF load capacitor. The dc consumption is about 14µA at DC and a 1.8-MHz gain,bandwidth product is obtained, providing significant improvement in both (MHzpF)/mA and ((V/µs)pF)/mA performance parameters. Copyright © 2007 John Wiley & Sons, Ltd. [source] Detecting and classifying delay Data Exceptions on communication networks using rule based algorithmsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2005Tammam Benmusa Abstract Network performance monitoring is essential for managing a network efficiently and for ensuring reliable operation of the network. Monitored network performance changes reflect events in the network, such as faults, significant changes in usage patterns or planned alterations. Network managers are interested in how and when the performance of a network changes; however it is inefficient to analyse all the data resulting from the monitoring operation manually. In this paper a rule based algorithm to automate detection of the changes in one of the network performance parameters, namely delay, is presented and described in detail. The nature of the delay pattern in a commercial communication network was the key issue in developing this algorithm. The approach was tested with monitored delay data generated from three different networks and showed good results. Also, the algorithm was tested with sets of delay data which have been already input to a previously developed detector based on a different approach, and the results between the two detectors are compared. In addition to a noticeable improvement in detection performance, the new approach provides more generality and independency of the source of the delay data, making the approach generally applicable to other networks. Copyright © 2004 John Wiley & Sons, Ltd. [source] Performance analysis of gas liquefaction cyclesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2008Mehmet Kanoglu Abstract Relations are developed for first- and second-law analyses of the simple Linde,Hampson cycle used in gas liquefaction systems. An expression for the minimum work requirement, which is applicable to any gas liquefaction system, is developed with the help of a Carnot refrigerator. It is shown that the minimum work depends only on the properties of the incoming and outgoing gas streams and the environment temperature. Numerical calculations are performed to obtain the performance parameters of different gases while parametric studies are done to investigate the effects of liquefaction and inlet gas temperatures on various first- and second-law performance parameters. As the liquefaction temperature increases and the inlet gas temperature decreases, the liquefied mass fraction, the coefficient of performance (COP) and the exergy efficiency increase while actual and reversible work consumptions decrease. The exergy efficiency values appear to be low, indicating significant potential exists for improving efficiency and thus decreasing the required work consumption for a specified amount of liquefaction. Copyright © 2007 John Wiley & Sons, Ltd. [source] Investigation of the temperature oscillations in the cylinder walls of a diesel engine with special reference to the limited cooled caseINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2004C. D. Rakopoulos Abstract This work investigates the interesting phenomenon of the temperature (cyclic) oscillations in the combustion chamber walls of a diesel engine. For this purpose, a comprehensive simulation code of the thermodynamic cycle of the engine is developed taking into account both the closed and the open parts of it. The energy and state equations are applied, with appropriate combustion, gas heat transfer, and mass exchange with the atmosphere sub-models, to yield cylinder pressure, local temperatures and heat release histories as well as various performance parameters of the engine. The model is appropriately coupled to a wall periodic conduction model, which uses the gas temperature variation as boundary condition throughout the engine cycle after being treated by Fourier analysis techniques. It is calibrated against measurements, at various load and speed conditions, from an experimental work carried out on a direct injection (DI), naturally aspirated, four-stroke, diesel engine located at the authors' laboratory, which has been reported in detail previously. After gaining confidence into the predictive capabilities of the model, it is used to investigate the phenomenon further, thus providing insight into many interesting aspects of transient engine heat transfer, as far as the influence that engine wall material properties have on the values of cyclic temperature swings. These swings can take prohibitive values causing high wall thermal fatigue, when materials of specific technological interest such as thermal insulators (ceramics) are used, and may lead to deterioration in engine performance. Copyright © 2004 John Wiley & Sons, Ltd. [source] Neural networks,a new approach to model vapour-compression heat pumpsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 7 2001H. Bechtler Abstract The aim of this paper is to model the steady-state performance of a vapour-compression liquid heat pump with the use of neural networks. The model uses a generalized radial basis function (GRBF) neural network. Its input vector consists only of parameters that are easily measurable, i.e. the chilled water outlet temperature from the evaporator, the cooling water inlet temperature to the condenser and the evaporator capacity. The model then predicts relevant performance parameters of the heat pump, especially the coefficient of performance (COP). Models are developed for three different refrigerants, namely LPG, R22 and R290. It is found that not every model achieves the same accuracy. Predicted COP values, when LPG or R22 are used as refrigerant, are usually accurate to within 2 per cent, whereas many predictions for R290 deviate more than ±10 per cent. Copyright © 2001 John Wiley & Sons, Ltd. [source] A simulation model for design and evaluation of micro-irrigation systemsIRRIGATION AND DRAINAGE, Issue 4 2001C.M.G. Pedras goutteurs; micro-aspersion; modèle AVALOC; analyse des performances Abstract The rational use and conservation of water resources require that irrigation performance, including emission uniformity, be as high as possible. Simulation models can help achieve these objectives. The AVALOC model has been developed for design and performance analysis of microirrigation systems, adopting the sector as the unit for analysis. The model works with the Windows operating system and is explored interactively through a simple dialogue structure consisting of a sequence of user-friendly interfaces. Model computations are supported by a database containing updated information on the emitters and pipes available on the market, and where the information relative to the sectors being designed or evaluated is stored. The databases allow easy introduction, visualization and correction of data through a user-friendly menu. In the design mode, the model provides for the selection of pipes and emitters that permit the attainment of the target performance, including emitter discharge uniformity. In the performance analysis mode, a hydraulics simulation is executed and several system performance parameters are then computed. The simulation can be performed using data created during design or data collected from field system evaluation. The present paper describes the main features of the model and shows a design example applied to an olive orchard. Copyright © 2001 John Wiley & Sons, Ltd. L'utilisation rationnelle des ressources en eau et la conservation des ressources naturelles requiert que les performances des systèmes d'irrigation soient les plus hautes que possible. L'utilisation des modèles de simulation pour le projet et l'évaluation des systèmes de microirrigation peut aider à atteindre un tel objectif. Ainsi, le modèle AVALOC a été développé pour le projet de ces systèmes et aussi pour leur analyse de performance. Le modèle utilise le language Visual Basic pour le système opératif Windows et il est exploré à travers d'un ensemble d'interfaces de dialogue avec l'utilisateur. L'unité d'analyse est le secteur d'irrigation. Les calculs font appel à une base de données contenant de l'information actualisée sur les caractéristiques des émisseurs , gouteurs et microasperseurs , et des conduites disponibles sur le marché et où l'on emmagasine l'information relative aux secteurs en cours de projet ou d'évaluation. Les bases de données sont accedées par une interface de dialogue qui permet l'introduction, visualisation ou correction des données. Le mode de projet permet la selection des emisseurs et tuyaux qui donnent satisfaction aux objectfs de performance fixés à priori. La simulation du fonctionnement hydraulique du secteur en projet permet le calcul de plusieurs indicateurs de performance et, donc, de vérifier si la solution considérée doit être retenue ou modifiée, le modèle étant utilisé de façon interactive. Le mode de simulation hydraulique est aussi utilisé avec des données de terrain pour évaluer la performance des systèmes en operation. Cet article décrit les caractéristiques principales du modèle en même temps qu'on présente un exemple d'application à un système de goutte à goutte pour un olivier. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effect of L -carnitine supplementation on performance parameters in gilts and sowsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2001K. Eder The effect of L-carnitine supplementation during pregnancy and lactation on performance parameters of sows was studied. The trial comprised a total of 127 sows (40 gilts, 87 mature sows) which were divided into a control and a treatment group. All animals were fed individually and received basic feed mixtures for pregnancy and lactation with low carnitine concentrations (gestation diet: 4.7 mg/kg feed, lactation diet: 12.5 mg/kg feed). The rations of the sows in the treated group were supplemented with 125 mg L -carnitine per head and day during pregnancy and 250 mg L -carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L -carnitine supplement. L -carnitine supplementation resulted in higher sow liveweight gains between day 1 and day 85 of pregnancy. The number of piglets per litter and the number born alive did not differ between the control sows and those treated with L -carnitine. However, the L -carnitine-supplemented sows produced only half as many non-viable piglets as the control animals. Moreover, litter weight and mean birth weight of piglets from L -carnitine-treated sows were higher than in the control sows. This effect was more marked in gilts (+8% higher litter weight, +9% higher piglet weight) than in sows (+7% and +6%, respectively). Piglets from sows whose ration was supplemented with L -carnitine showed higher liveweight gains during the suckling period (+12% for gilts, +4% for sows), which is why litter weights post weaning were also higher among the sows treated with L -carnitine than in the control sows (+14% for gilts, +10% for sows). Overall, the study shows that dietary supplementation with L -carnitine during pregnancy and lactation improves the reproductive performance of sows. [source] Untersuchungen zum Einfluß einer Xylanaseergänzung in Legehennenrationen auf Weizenbasis 2.JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2000Mitteilung: Auswirkungen auf die Leistungsparameter Summary The influence of a xylanase supplement on performance of laying hens fed different energy-graded, wheat-based rations was tested in a 12-week trial. Two varieties of wheat with different extraction viscosity were selected. In addition to the control ration, three test rations with reduced energy contents of ,3, ,6, and ,9% were used. Sixteen groups, each consisting of 30 hens were kept in single cages. At the beginning of the experiment hens were 24 weeks old. Single eggmass and daily eggmass production showed a statistically significant difference. This was not caused by the enzyme supplement or the energy content, but by the variety of wheat. Interaction effects between variety of wheat, enzyme supplement and energy content became obvious with regard to the yolk colour. The influence of the enzyme on the yolk colour is positive and statistically highly significant. Thus, the addition of xylanase to wheat-based rations does not affect the performance parameters of laying hens positively. Zusammenfassung In einem zwölfwöchigem Leistungsversuch wurde der Einfluß einer Xylanaseergänzung in Legehennenrationen auf Weizenbasis mit abgestuftem Energiegehalt auf die Leistungsparameter untersucht. Dazu wurden zwei Weizensorten (Alidos + Caprimus) mit unterschiedlicher Extraktviskosität ausgesucht und neben den jeweiligen Kontrollrationen drei Versuchsrationen mit abgestuftem Energiegehalt (,3%, ,6%, ,9%) eingesetzt. Den 16 Versuchsgruppen waren jeweils 30 Legehennen zugeordnet, die bei Versuchsbeginn 24 Lebenswochen alt waren. Es handelte sich um eine Einzelkäfigaufstallung. Statistisch signifikante Unterschiede ergaben sich bei der Einzeleimasse und der täglichen Eimasseproduktion, die sich jedoch weder dem Enzymzusatz noch dem Energiegehalt zuordnen ließen, sondern durch die Weizensorte bedingt waren. Es zeigten sich Wechselwirkungen zwischen Weizensorte, Enzymsupplementierung und Energiegehalt auf die Dotterfarbe. Es war ein statistisch hochsignifikanter positiver Enzymeinfluß auf die Dotterfarbe zu erkennen. Insgesamt gesehen, zeigte sich auch in diesem Legehennenversuch keine positive Wirkung der Xylanaseergänzung auf die Leistungsparamter zu Rationen auf Weizenbasis. [source] Single Laboratory Method Performance Evaluation for the Analysis of Total Food Folate by Trienzyme Extraction and Microplate AssayJOURNAL OF FOOD SCIENCE, Issue 5 2007L. Chen ABSTRACT:, Single laboratory method performance parameters, including the calibration curve, accuracy, recovery, precision, limit of detection (LOD), and limit of quantification (LOQ), were evaluated for the analysis of total food folate by the trienzyme extraction and microplate assay with Lactobacillus casei subsp. rhamnosus. Standard Reference Material (SRM) 1546 (meat homogenate), SRM 2383 (baby food composite), SRM 1846 (infant formula), Certified Reference Material (CRM) 121 (wholemeal flour), and CRM 485 (mixed vegetables), representing a broad selection of food matrices, were used to evaluate the performance of the method. A generated 4-parameter logistic equation of the calibration curve was y= (0.0705 , 1.0396)/(1 + (x/0.0165) 1.3072) + 1.0396 (P < 0.0001). The test of parallelism demonstrated that matrix components in the food extracts did not affect the accuracy. Measured values of the SRMs and CRMs were within their certified or reference values. Recoveries for all reference materials met the requirements of the AOAC guidelines for single laboratory validation. Precision measured as repeatability, including simultaneous and consecutive replicates for each SRM and CRM, met the Horwitz criterion. LOD and LOQ values were 0.3 and 0.6 ,g/100 g, respectively. The results showed that trienzyme digestion using ,-amylase, PronaseR, and conjugase from chicken pancreas coupled with a 96-well microplate assay provided a highly accurate, reproducible, and sensitive method for the determination of folate in a variety of foods. [source] Preference,performance relationship and influence of plant relatedness on host use by Pityogenes chalcographus L.AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2009Coralie Bertheau Abstract 1Pityogenes chalcographus L. (Coleoptera: Scolytinae) causes damage in European coniferous forests, primarily on Picea abies L. Karst., but is also recorded on other native and exotic Pinaceae species. Estimating the adequacy between adult preference and larval performance of this beetle among its host-range, as well as the influence of plant taxonomic relatedness on these parameters, would provide useful information on the beetle's ability to shift onto novel hosts. 2Choice and no-choice assays were conducted under laboratory conditions. Adult preference and larval performance parameters among two native (Pinus sylvestris L. and Picea abies) and three exotic north American [Pinus contorta Dougl., Picea sitchensis (Bong.) Carr. and Pseudotsuga menziesii Mirbel (Franco)] conifer species were measured. 3Pityogenes chalcographus exhibited a significant positive relationship between preference and performance. Picea abies was both the preferred and the most suitable host species for larval development. The closest relative, P. sitchensis, was the second best choice in terms of preference and performance. Pseudotsuga menziesii occupied an intermediate position for both beetle preference and performance, and Pinus spp. were the least suitable hosts for beetle development. 4Adult preference and larval performance ranking among hosts provides little support to the plant taxonomic relatedness hypothesis. Taxonomic relatedness could play a role on the diet breadth, although only at a limited scale, within the genus Picea. At higher taxonomic levels, other factors such as bark thickness might be decisive. [source] A computational study of the porosity effects in silica monolithic columnsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10-11 2004Piotr Gzil Abstract We report on a theoretical study of the influence of the through-pore porosity on the main chromatographic performance parameters (reduced theoretical plate height, flow resistance, and separation impedance) of silica monoliths. To investigate this problem devoid of any structural uncertainties, computer-generated structural mimics of the pore geometry of silica monolithic columns have been studied. The band broadening in these synthetic monoliths was determined using a commercial Computational Fluid Dynamics (CFD) software package. Three widely differing external porosities (, = 0.38, , = 0.60, and , = 0.86) are considered and are compared on the basis of an identical intra-skeleton diffusivity (D s = 5×10,10m2/s), internal porosity (,int = 0.5), and for the same phase retention factor (k ´ = 1.25). Since the data are obtained for perfectly ordered structures, the calculated plate heights and separation impedances constitute the ultimate performance ever to be expected from a monolithic column. It is found that, if silica monoliths could be made perfectly homogeneous, domain size-based reduced plate heights as small as h min , 0.8 (roughly independent of the porosity) and separation impedances as small as Emin , 130 (, = 0.60) and Emin , 40 (, = 0.86) should be achievable with pure water as the working fluid. The data also show that, although the domain size is a much better reduction basis than the skeleton size, the former is still not capable of bringing the van Deemter curves of different porosity columns into perfect agreement in the C term dominated velocity range. It is found that, in this range, large porosity monoliths can be expected to yield smaller domain size-based reduced plate heights than small porosity monoliths. [source] Multiband MIMO antenna with independent resonance frequency adjustabilityMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2010Min-Seok Han Abstract A compact multiband multiple-input multiple-output (MIMO) antenna with a band stop matching circuit for next generation mobile applications is proposed. The proposed multiband MIMO antenna consists of two dual-band planar inverted-F antennas, which provide wideband characteristics. To improve the isolation characteristic at the long term evolution band, a band stop matching circuit was inserted at the corner of each antenna element. The proposed MIMO antenna has isolation of ,15 dB at the lower band and over 20 dB at the upper band. In addition, the resonant frequencies of the proposed MIMO antenna can be independently tuned by changing the value of the inductor or by adjusting the widths of Slit1 and Slit2. To evaluate the performance of the proposed antenna, key performance parameters such as total efficiency, envelope correlation coefficient, mean effective gain (MEG), and the MEG ratio are analyzed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1893,1901, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25334 [source] SAR of internal antenna in mobile-phone applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2005K. H. Chan Abstract This paper presents an investigation of the effect of the internal antenna on the specific absorption rate (SAR), and the effect of the presence of a human head at close proximity to a mobile phone upon the antenna performance in mobile-phone applications. Both the experimental measurement and numerical simulation of the SAR values and the antenna performance parameters of a typical internal antenna are presented. The results indicate that the far-field radiations of the internal antenna can be reduced by 3 dB with the presence of human head. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45:286,290, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20797 [source] Fatigue rating scales critique and recommendations by the Movement Disorders Society task force on rating scales for Parkinson's disease,MOVEMENT DISORDERS, Issue 7 2010Joseph H. Friedman MD Abstract Fatigue has been shown to be a consistent and common problem in Parkinson's disease (PD) in multiple countries and cultures. It is one of the most disabling of all symptoms, including motor dysfunction, and appears early, often predating the onset of motor symptoms. Several studies of the epidemiology of fatigue have been published, often using different scales, but few on treatment. The Movement Disorder Society (MDS) commissioned a task force to assess available clinical rating scales, critique their psychometric properties, summarize their clinical properties, and evaluate the evidence in support of their use in clinical studies in PD. Six clinical researchers reviewed all studies published in peer reviewed journals of fatigue in PD, evaluated the scales' previous use, performance parameters, and quality of validation data, if available. Scales were rated according to criteria provided by the MDS. A scale was "recommended" if it has been used in clinical studies beyond the group that developed it, has been used in PD and psychometric studies have established that it is a valid, reliable and sensitive to change in people with PD. Requiring a scale to have demonstrated sensitivity to change in PD specifically rather than in other areas in order to attain a rating of "recommended" differs from the use of this term in previous MDS task force scale reviews. "Suggested" scales failed to meet all the criteria of a "recommended" scale, usually the criterion of sensitivity to change in a study of PD. Scales were "listed" if they had been used in PD studies but had little or no psychometric data to assess. Some scales could be used both to screen for fatigue as well as to assess fatigue severity, but some were only used to assess severity. The Fatigue Severity Scale was "recommended" for both screening and severity rating. The Fatigue Assessment Inventory, an expanded version of the Fatigue severity Scale, is "suggested" for both screening and severity. The Functional Assessment of Chronic Illness Therapy-Fatigue was "recommended" for screening and "suggested" for severity. The Multidimensional Fatigue Inventory was "suggested" for screening and "recommended" for severity. The Parkinson Fatigue Scale was "recommended" for screening and "suggested" for severity rating. The Fatigue Severity Inventory was "listed" for both screening and severity. The Fatigue Impact Scale for Daily Use, an adaptation of the Fatigue Impact Scale was "listed" for screening and "suggested" for severity. Visual Analogue and Global Impression Scales are both "listed" for screening and severity. The committee concluded that current scales are adequate for fatigue studies in PD but that studies on sensitivity and specificity of the scales are still needed. © 2010 Movement Disorder Society [source] Dysautonomia rating scales in Parkinson's disease: Sialorrhea, dysphagia, and constipation,Critique and recommendations by movement disorders task force on rating scales for Parkinson's disease,MOVEMENT DISORDERS, Issue 5 2009Marian L. Evatt MD Abstract Upper and lower gastrointestinal dysautonomia symptoms (GIDS),sialorrhea, dysphagia, and constipation are common in Parkinson's disease (PD) and often socially as well as physically disabling for patients. Available invasive quantitative measures for assessing these symptoms and their response to therapy are time-consuming, require specialized equipment, can cause patient discomfort and present patients with risk. The Movement Disorders Society commissioned a task force to assess available clinical rating scales, critique their clinimetric properties, and make recommendations regarding their clinical utility. Six clinical researchers and a biostatistician systematically searched the literature for scales of sialorrhea, dysphagia, and constipation, evaluated the scales' previous use, performance parameters, and quality of validation data (if available). A scale was designated "Recommended" if the scale was used in clinical studies beyond the group that developed it, has been specifically used in PD reports, and clinimetric studies have established that it is a valid, reliable, and sensitive. "Suggested" scales met at least part of the above criteria, but fell short of meeting all. Based on the systematic review, scales for individual symptoms of sialorrhea, dysphagia, and constipation were identified along with three global scales that include these symptoms in the context of assessing dysautonomia or nonmotor symptoms. Three sialorrhea scales met criteria for Suggested: Drooling Severity and Frequency Scale (DSFS), Drooling Rating Scale, and Sialorrhea Clinical Scale for PD (SCS-PD). Two dysphagia scales, the Swallowing Disturbance Questionnaire (SDQ) and Dysphagia-Specific Quality of Life (SWAL-QOL), met criteria for Suggested. Although Rome III constipation module is widely accepted in the gastroenterology community, and the earlier version from the Rome II criteria has been used in a single study of PD patients, neither met criteria for Suggested or Recommended. Among the global scales, the Scales for Outcomes in PD-Autonomic (SCOPA-AUT) and Nonmotor Symptoms Questionnaire for PD (NMSQuest) both met criteria for Recommended, and the Nonmotor Symptoms Scale (NMSS) met criteria for Suggested; however, none specifically focuses on the target gastrointestinal symptoms (sialorrhea, dysphagia, and constipation) of this report. A very small number of rating scales have been applied to studies of gastrointestinal-related dysautonomia in PD. Only two scales met "Recommended" criteria and neither focuses specifically on the symptoms of sialorrhea, dysphagia, and constipation. Further scale testing in PD among the scales that focus on these symptoms is warranted, and no new scales are needed until the available scales are fully tested clinimetrically. © 2009 Movement Disorder Society [source] Technical Performance of Percutaneous and Laminectomy Leads Analyzed by ModelingNEUROMODULATION, Issue 4 2004Ljubomir Manola Dipl. Abstract The objective of this study was to compare the technical performance of laminectomy and percutaneous spinal cord stimulation leads with similar contact spacing by computer modeling. Monopolar and tripolar (guarded cathode) stimulation with both lead types in a low-thoracic spine model was simulated using UT-SCS software. Dorsal column and dorsal root fiber thresholds were calculated as well as the area of recruited fibers in the dorsal columns, the rostrocaudal span of recruited dorsal root fibers and the energy consumption at discomfort threshold. Tripolar stimulation is superior to monopolar stimulation in the recruitment of the dorsal columns, a percutaneous lead recruits a ,12% larger dorsal column area than a laminectomy lead does. This difference is reduced when the contact spacing of the lead models is the same. A percutaneous lead with significant wire impedance (140 Ohms) consumes ,115,240% more energy, whereas the same lead with negligible wire impedance consumes ,40,85% more energy. A deterioration of all performance parameters is predicted when a percutaneous lead is placed more dorsally in the epidural tissue. When positioned next to the dura mater, a percutaneous lead has a similar performance (fiber recruitment in the dorsal columns and the dorsal roots) as a laminectomy lead with similar contact spacing, but substantially higher energy consumption. The superior clinical performance of the laminectomy lead is most probably due to the difference in volume and insertion technique of the two lead types. [source] Compatibility factor for the power output of a thermogeneratorPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 6 2007W. Seifert Abstract The compatibility approach introduced by Snyder and Ursell enables the description of both thermoelectric generator (TEG) and Peltier cooler (TEC) within the framework of a unified 1D model. Both TEG's efficiency , and TEC's coefficient of performance (C.O.P.) can be formulated in terms of the reduced current density u, which has been introduced as a new, intensive state variable of a thermoelectric system. For , and C.O.P., integral expressions are formed from additive contributions of all length segments of a thermoelectric ele-ment, enabling exact calculation of these quantities even for arbitrarily graded elements. Maximization of these global performance parameters can thus be deduced to local maximization. Here the maximum power from a TEG with fixed length but variable heat supply is considered, which leads to the new concept of power-related compatibility and to the introduction of a new, different compatibility factor. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preparation and properties of a novel high-performance resin system with low injection temperature for resin transfer mouldingPOLYMER INTERNATIONAL, Issue 9 2004Dr Aijuan Gu Abstract A novel high-performance resin system with low injection temperature for resin transfer moulding, M4506, was developed, which was made of 4,4,-bismaleimidodiphenylmethane, o,o,-diallyl bisphenol A, o,o,-diallyl bisphenol A ether, and 1,1,-bis(4-cyanatophenyl)ethane. The processing characteristics, thermal and mechanical properties of the system were studied, and the effect of differing stoichiometries of each component on the processing and performance parameters was discussed. Investigations show that the processing properties of the M4506 system are greatly dependent on the stoichiometries of each component in the formulations, while all the three formulations developed in this paper have good processing characteristics, their suitable injection temperature are between 40 and 50 °C, depending on their respective formulation. The three formulations exhibited outstanding heat resistance (Tg = 294,300 °C) and thermal stability, good toughness and high strength, evidence that the M4506 system is a potential candidate as a high-performance RTM matrix for advance composites as well as high-performance paints with no solvents. Copyright © 2004 Society of Chemical Industry [source] Quality in the outsourcing process: part I. The quality outsourcerQUALITY ASSURANCE JOURNAL, Issue 4 2001Yvonne Russell Dr. Abstract In clinical research, the definition of quality and overall responsibility for ensuring that performance parameters are adequately tracked and the necessary corrective action taken, lies firmly in the hands of the outsourcing project director/manager (outsourcer or sponsor). Meticulous planning of requirements prior to project start and strong ,general management' throughout the life of the outsourced project play a critical role in influencing both the outcome of the study and also in determining the quality of the research data. For ,quality in the outsourcing process', read ,quality outsourcing'. The implementation of a carefully formulated project-specific outsourcing strategy means that macromanagement (general management), not micromanagement (defined here as a form of ,intensive therapy for the ailing project' management), will be the primary task of the sponsor. A research team that is well-defined, with all members (sponsor and vendor alike) mindful of their individual responsibilities, in addition to being well-directed, will achieve consensus of opinion faster and deliver a quality product. An outsourcing strategy for the full clinical development program, clearly defined outsourcing standard operating procedures (SOPs) and a strategy tailored to each individually outsourced project form an integral part of the recipe to outsourcing success. Individual components of an outsourcing strategy and how one can safeguard that an outsourced project is brought to completion successfully, and to the prescribed quality standards, are addressed in detail in this article. Part two of this article, entitled ,Quality in the Outsourcing Process: II. The Vendor Selection Process and The Quality Vendor', will provide the quality outsourcer with tips and tools on how to make a quality decision in the vendor selection process and addresses further issues that are fundamental to the maintenance of quality in the outsourcing process. Copyright © 2001 John Wiley & Sons, Ltd. [source] Application of the operating window concept to remediation-option selectionREMEDIATION, Issue 3 2004Duncan I. Scott An Erratum has been published for this article in Remediation 14(4) 2004, 141. The selection of remediation options for the management of unacceptable risks at contaminated sites is hindered by insufficient information on their performance under different site conditions. Therefore, there is a need to define "operating windows" for individual remediation options to summarize their performance under a variety of site conditions. The concept of the "operating window" has been applied as both a performance optimization tool and decision support tool in a number of different industries. Remediation-option operating windows could be used as decision support tools during the "options appraisal" stage of the Model Procedures (CLR 11), proposed by the Environment Agency (EA) for England and Wales, to enhance the identification of "feasible remediation options" for "relevant pollutant linkages." The development of remediation-option operating windows involves: 1) the determination of relationships between site conditions ("critical variables") and option performance parameters (e.g., contaminant degradation or removal rates) and 2) the identification of upper- and lower-limit values ("operational limits") for these variables that define the ranges of site conditions over which option performance is likely to be sufficient (the "operating window") and insufficient (the "operating wall") for managing risk. Some research has used case study data to determine relationships between critical variables and subsurface natural attenuation (NA) process rates. Despite the various challenges associated with the approach, these studies suggest that available case study data can be used to develop operating windows for monitored natural attenuation (MNA) and, indeed, other remediation options. It is envisaged that the development of remediation-option operating windows will encourage the application of more innovative remediation options as opposed to excavation and disposal to landfill and/or on-site containment, which remain the most commonly employed options in many countries. © 2004 Wiley Periodicals, Inc. [source] Closed-loop feedback computer-controlled infusion of phenylephrine for maintaining blood pressure during spinal anaesthesia for caesarean section: a preliminary descriptive study,ANAESTHESIA, Issue 12 2007W. D. Ngan Kee Summary We describe the novel use of a closed-loop feedback computer-controlled infusion of phenylephrine for maintaining blood pressure in 53 patients having spinal anaesthesia for elective caesarean section. A simple on,off algorithm was used that activated an intravenous phenylephrine infusion at 100 ,g.min,1 when systolic blood pressure was less than or equal to baseline and stopped the infusion when systolic blood pressure exceeded baseline. Up to uterine incision, 94.6% of all systolic blood pressure measurements were within the range (baseline ± 20%). Seven patients (13.2%) had one or more episodes of hypotension (systolic blood pressure < 80% of baseline) and 23 patients (37.7%) had one or more episodes of hypertension (systolic blood pressure >,120% of baseline). No patient had nausea or vomiting and in no case was umbilical arterial blood pH < 7.2. Calculated system performance parameters were comparable with those of previously published closed-loop systems and provide a reference for the potential development and comparison of more advanced algorithms. [source] Virtual reality simulators: Current status in acquisition and assessment of surgical skillsANZ JOURNAL OF SURGERY, Issue 1 2002Peter H. Cosman Medical technology is currently evolving so rapidly that its impact cannot be analysed. Robotics and telesurgery loom on the horizon, and the technology used to drive these advances has serendipitous side-effects for the education and training arena. The graphical and haptic interfaces used to provide remote feedback to the operator , by passing control to a computer , may be used to generate simulations of the operative environment that are useful for training candidates in surgical procedures. One additional advantage is that the metrics calculated inherently in the controlling software in order to run the simulation may be used to provide performance feedback to individual trainees and mentors. New interfaces will be required to undergo evaluation of the simulation fidelity before being deemed acceptable. The potential benefits fall into one of two general categories: those benefits related to skill acquisition, and those related to skill assessment. The educational value of the simulation will require assessment, and comparison to currently available methods of training in any given procedure. It is also necessary to determine , by repeated trials , whether a given simulation actually measures the performance parameters it purports to measure. This trains the spotlight on what constitutes good surgical skill, and how it is to be objectively measured. Early results suggest that virtual reality simulators have an important role to play in this aspect of surgical training. 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