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System Components (system + component)
Selected AbstractsRefactoring service-based systems: how to avoid trusting a workflow serviceCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2006Howard Chivers Abstract Grid systems span multiple organizations, so their workflow processes have security requirements, such as restricting access to data or ensuring that process constraints are observed. These requirements are often managed by the workflow component, because of the close association between this sub-system and the processes it enacts. However, high-quality security mechanisms and complex functionality are difficult to combine, so designers and users of workflow systems are faced with a tradeoff between security and functionality, which is unlikely to provide confidence in the security implementation. This paper resolves that tension by showing that process security can be enforced outside the workflow component. Separating security and process functionality in this way improves the quality of security protection, because it is implemented by standard system mechanisms; it also allows the workflow component to be deployed as a standard service, rather than a privileged system component. To make this change of design philosophy accessible outside the security community it is documented as a collection of refactorings, which include problem templates that identify suspect design practice, and target patterns that provide solutions. Worked examples show that these patterns can be used in practice to implement practical applications, with both traditional workflow security concerns, and Grid requirements. Copyright © 2005 John Wiley & Sons, Ltd. [source] A dynamic bandwidth resource allocation based on neural networks in euroskyway multimedia satellite systemINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2003P. Camarda Abstract Advanced traffic management based on the dynamic resource assignment allows a broadband satellite system such as euroskyway (ESW) to dynamically assign the resources of connections. The mechanisms of the dynamic assignment exploit variations of burstiness exhibited by real time and non-real time variable bit rate traffic sources to perform an optimized resource redistribution. The efficiency of the dynamic bandwidth allocation capability (DBAC) depends on the accuracy of the traffic source description; inaccurate assessment of the arrival process will cause an overhead and a degraded utilisation of system resources. In this paper a flexible traffic burstiness predictor for dynamic bandwidth resource allocation based on neural network is presented. The approach is able to perform an online estimation of expected resource requests implementing traffic resource assignment by using a sub-symbolic adaptive representation of the traffic source. The achieved results prove that the flexible approach is more effective than the ones based on fixed schemes designed using analytical traffic source description when applied on the satellite terminal ESW system component. Copyright © 2003 John Wiley & Sons, Ltd. [source] Second law analysis of two-stage compression transcritical CO2 heat pump cycleINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 13 2008Arif Emre Özgür Abstract Because of the global warming impact of hydro fluorocarbons, the uses of natural refrigerants in automotive and HVAC industries have received worldwide attention. CO2 is the most promising refrigerant in these industries, especially the transcritical CO2 refrigeration cycle. The objective of this work is to identify the main factors that affect two-stage compression transcritical CO2 system efficiency. A second law of thermodynamic analysis on the entire two-stage CO2 cycle is conducted so that the exergy destruction of each system component can be deduced and ranked, allowing future efforts to focus on improving the components that have the highest potential for advancement. The inter-stage pressure is used as a variable parameter in the analysis study. The second law efficiency, coefficient of cooling performance and total exergy destruction of the system variations with the inter-stage pressure are presented graphically. It was concluded that there is an optimum inter-stage pressure that maximizes both first law and second law efficiencies. Copyright © 2008 John Wiley & Sons, Ltd. [source] Organic greenroof architecture: Design considerations and system componentsENVIRONMENTAL QUALITY MANAGEMENT, Issue 1 2005Linda S. Velazquez First page of article [source] Tunable Colors in Opals and Inverse Opal Photonic CrystalsADVANCED FUNCTIONAL MATERIALS, Issue 16 2010Carlos I. Aguirre Abstract Colloidal photonic crystals and materials derived from colloidal crystals can exhibit distinct structural colors that result from incomplete photonic band gaps. Through rational materials design, the colors of such photonic crystals can be tuned reversibly by external physical and chemical stimuli. Such stimuli include solvent and dye infiltration, applied electric or magnetic fields, mechanical deformation, light irradiation, temperature changes, changes in pH, and specific molecular interactions. Reversible color changes result from alterations in lattice spacings, filling fractions, and refractive index of system components. This review article highlights the different systems and mechanisms for achieving tunable color based on opaline materials with close-packed or non-close-packed structural elements and inverse opal photonic crystals. Inorganic and polymeric systems, such as hydrogels, metallopolymers, and elastomers are discussed. [source] Experimental Analysis on Performance and Durability of SOFC Demonstration UnitFUEL CELLS, Issue 3 2010M. Halinen Abstract A technical description and experimental analysis of a SOFC demonstration unit is presented. The unit contains most of the primary BoP-components of a complete SOFC system, except of air and fuel recirculation equipment or fuel system compressor. Natural gas is used as the fuel and electricity is supplied to the electric grid. A 5,kW power class planar SOFC stack from Research Centre Jülich is assembled to the demo unit and a long-term experiment is conducted to assess the characteristic performance and durability of different components of the unit (e.g. the SOFC stack, the fuel pre-reformer and air heat exchangers). The evolution of absolute voltage drop of the stack over time is found to be of the same magnitude when compared to short stack experiments. Thus, other system components are not observed to cause an increase in the characteristic voltage drop of the stack. Two BoP-components, the afterburner and the power conversion unit failed to operate as designed. The performance of other BoP-components i.e. fuel pre-reformer and heat exchangers were satisfactory during the test run, and no significant performance loss could be measured. [source] Functional genomics studies on the innate immunity of disease vectorsINSECT SCIENCE, Issue 1 2008Luke A. Baton Abstract The increasing availability of genome sequences and the development of high-throughput techniques for gene expression profiling and functional characterization are transforming the study of innate immunity and other areas of insect biology. Already, functional genomic approaches have enabled a quantum advance in the characterization of mosquito immune responses to malaria parasite infection, and similar high-throughput functional genomic studies of other vector-pathogen interactions can be expected in the near future. The application of microarray-based and other expression analyses provide genome-wide transcriptional profiles that can be used to identify insect immune system components that are differentially regulated upon exposure to various classes of pathogens, including many important etiologic agents of human and animal diseases. The role of infection-responsive or other candidate immune genes identified through comparative genomic approaches can then be functionally characterized, either in vivo, for instance in adult mosquitoes, or in vitro using cell lines. In most insect vectors of human pathogens, germ-line transgenesis is still technically difficult and maintenance of multiple transgenic lines logistically demanding. Consequently, transient RNA interference (RNAi)-mediated gene-silencing has rapidly become the method of choice for functional characterization of candidate innate immune genes. The powerful combination of transcriptional profiling in conjunction with assays using RNAi to determine gene function, and identify regulatory pathways, together with downstream cell biological approaches to determine protein localization and interactions, will continue to provide novel insights into the role of insect innate immunity in a variety of vector-pathogen interactions. Here we review advances in functional genomics studies of innate immunity in the insect disease vectors, over the past decade, with a particular focus on the Anopheles mosquito and its responses to malaria infection. [source] Dynamic-window search for real-time simulation of dynamic systemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 11 2003Sugjoon Yoon Abstract 1Various parameter values are provided in the form of tables, where data keys are ordered and unevenly spaced in general, for real-time simulation of system components or dynamics of vehicles such as airplanes, automobiles, ships, and so on. The main purpose of this study is to compare conventional searching algorithms and to find or develop the most efficient searching method under constraint of real-time simulation, especially hardware-in-the-loop simulation. Since the real-time constraint enforces use of a fixed step size in the integration of system differential equations because of the inherent nature of input from and output to real hardware, the worst case of iterated probes in searching algorithms is the key measure of comparison. If a parameter value has certain dynamics because of its relation with the state variables of the simulated system, the integration algorithm and the step size, a searching region at a given time frame can be reduced dramatically from the entire data table taking advantage of the information. The size of the reduced searching region, named dynamic-searching window, varies and the window moves by its own dynamics as simulation time runs. Numerous numerical experiments were conducted with various data tables of different sizes and types, and yielded results compatible with relevant theories. In conclusion, whether bisection or interpolation or fast search is used in real-time hardware-in-the-loop simulation, the combination of dynamic-window search guarantees a more stable and faster search of parameter values than using conventional algorithms alone. Copyright © 2003 John Wiley & Sons, Ltd. [source] An Arctic and antarctic perspective on recent climate changeINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2007John Turner Abstract We contrast recent climatic and environmental changes and their causes in the Arctic and the Antarctic. There are continuing increases in surface temperatures, losses of sea ice and tundra, and warming of permafrost over broad areas of the Arctic, while most of the major increase in Antarctic temperatures is on the Antarctic Peninsula associated with sea ice loss in the Bellingshausen,Amundsen Seas sector. While both natural atmospheric and oceanic variability, and changes in external forcing including increased greenhouse gas concentrations, must be considered in the quest for understanding such changes, the interactions and feedbacks between system components are particularly strong at high latitudes. For the 1950s to date in the Arctic and for 1957 to date in the Antarctic, positive trends in large-scale atmospheric circulation represented by the Arctic oscillation (AO) and Antarctic oscillations (AAO) and the Pacific North American (PNA) pattern contribute to the long-term temperature trends. However, continuing Arctic trends during the last decade of near neutral AO will require alternate explanations. The trend in the AAO since 1950 is larger than expected from natural variability and may be associated with the decrease in stratospheric ozone over Antarctic. The persistence shown in many Arctic and Antarctic Peninsula components of climate and their influence through possible feedback supports continuation of current trends over the next decade. One can expect large spatial and temporal differences, however, from the relative contributions of intrinsic variability, external forcing, and internal feedback/amplifications. It is particularly important to resolve regional feedback processes in future projections based on modeling scenarios. Copyright © 2006 Royal Meteorological Society. [source] Application of ozone treatment and pinch technology in cooling water systems design for water and energy conservationINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6 2010A. Ataei Abstract Re-circulating cooling water systems offer the means to remove heat from a wide variety of industrial processes that generate excess heat. Such systems consist of a cooling tower and a heat-exchanger network that conventionally has a parallel configuration. However, reuse of water between different cooling duties allows cooling water networks to be designed in a series arrangement. This results in performance improvement and increased cooling tower capacity. In addition, by the integration of ozone treatment into the cooling tower, the cycle of concentration can be increased. The ozone treatment also dramatically reduces the blow-down that, in turn, is environmentally constructive. In this study, a new environmental-friendly and cost-effective design methodology for cooling water systems was introduced. Using this design methodology, Integrated Ozone Treatment Cooling System (IOTCS), achievement of minimum environmental impacts and total cost were afforded through a simultaneous integration of the cooling system components using an ozone treatment cooling tower and optimum heat-exchanger network configuration. Moreover, in the proposed method, the cooling tower optimum design was achieved through a mathematical model. The IOTCS design method is based upon a complex design approach using a combined pinch analysis and mathematical programming that provides an optimum heat-exchanger configuration while maximizing water and energy conservation and minimizing total cost. Related coding in MATLAB version 7.3 was used for the illustrative example to obtain optimal values in the IOTCS design method computations. The results of the recently introduced design methodology were compared with the conventional method. Copyright © 2009 John Wiley & Sons, Ltd. [source] Dynamic energy and exergy analyses of an industrial cogeneration systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2010Yilmaz Yoru Abstract The study deals with the energetic and exergetic analyses of a cogeneration (combined heat and power, CHP) system installed in a ceramic factory, located in Izmir, Turkey. This system has three gas turbines with a total capacity of 13,MW, six spray dryers and two heat exchangers. In the analysis, actual operational data over one-month period are utilized. The so-called CogeNNexT code is written in C++ and developed to analyze energetic and exergetic data from a database. This code is also used to analyze turbines, spray dryers and heat exchangers in this factory. Specifications of some parts of system components have been collected from the factory. Based on the 720,h data pattern (including 43,200 data), the mean energetic and exergetic efficiency values of the cogeneration system are found to be 82.3 and 34.7%, respectively. Copyright © 2009 John Wiley & Sons, Ltd. [source] Exergetic performance assessment of a pilot-scale heat pump belt conveyor dryerINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2010Zafer Erbay Abstract In this study, olive leaves were dried in a pilot-scale heat pump (HP) belt conveyor dryer as a thin layer. Drying experiments were carried out at the drying air temperature range of 45,55°C with the drying air velocity range of 0.5,1.5,m,s,1. The performance of the system and the process was evaluated using exergy analysis method. The exergy loss and flow diagram (the so-called Grassmann diagram) of the dryer system was presented to give quantitative information regarding the proportion of the exergy input that is dissipated in the various system components. Effects of the drying air temperature and the velocity on the performance of the drying process were discussed. The actual coefficient of performance values were obtained to be 2.37 for the HP unit and 2.31 for the overall system, respectively. The most important component of the system for improving the efficiency was determined to be the compressor. Exergetic efficiencies of the drying of olive leaves were in the range of 67.45,81.95%. It was obtained that they increased as the drying air temperature decreased and the drying air velocity increased. Copyright © 2009 John Wiley & Sons, Ltd. [source] Thermoeconomic analysis of household refrigeratorsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2007Arif Hepbasli Abstract This study deals with thermoeconomic analysis of household refrigerators for providing useful insights into the relations between thermodynamics and economics. In the analysis, the EXCEM method based on the quantities exergy, cost, energy and mass is applied to a household refrigerator using the refrigerant R134a. The performance evaluation of the refrigerator is conducted in terms of exergoeconomic aspects based on the various reference state temperatures ranging from 0 to 20°C. The exergy destructions in each of the components of the overall system are determined for average values of experimentally measured parameters. Exergy efficiencies of the system components are determined to assess their performances and to elucidate potentials for improvement. Thermodynamic loss rate-to-capital cost ratios for each components of the refrigerator are investigated. Correlations are developed to estimate exergy efficiencies and ratios of exergy loss rate-to-capital cost as a function of reference (dead) state temperature. The ratios of exergy loss rates to capital cost values are obtained to vary from 2.949 × 10,4 to 3.468 × 10,4 kW US$,1. The exergy efficiency values are also found to range from 13.69 to 28.00% and 58.15 to 68.88% on the basis of net rational efficiency and product/fuel at the reference state temperatures considered, respectively. It is expected that the results obtained will be useful to those involved in the development of analysis and design methodologies that integrate thermodynamics and economics. Copyright © 2006 John Wiley & Sons, Ltd. [source] Exergetic performance assessment of a ground-source heat pump drying systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 8 2007Ebru Hancioglu Kuzgunkaya Abstract In evaluating the efficiency of heat pump (HP) systems, the most commonly used measure is the energy (or first law) efficiency, which is modified to a coefficient of performance (COP) for HP systems. However, for indicating the possibilities for thermodynamic improvement, energy analysis is inadequate and exergy analysis is needed. This study presents an exergetic assessment of a ground-source (or geothermal) HP (GSHP) drying system. This system was designed, constructed and tested in the Solar Energy Institute of Ege University, Izmir, Turkey. The exergy destructions in each of the components of the overall system are determined for average values of experimentally measured parameters. Exergy efficiencies of the system components are determined to assess their performances and to elucidate potentials for improvement. COP values for the GSHP unit and overall GSHP drying system are found to range between 1.63,2.88 and 1.45,2.65, respectively, while corresponding exergy efficiency values on a product/fuel basis are found to be 21.1 and 15.5% at a dead state temperature of 27°C, respectively. Specific moisture extraction rate (SMER) on the system basis is obtained to be 0.122 kg kW,1 h,1. For drying systems, the so-called specific moisture exergetic rate (SMExR), which is defined as the ratio of the moisture removed in kg to the exergy input in kW h, is also proposed by the authors. The SMExR of the whole GSHP drying system is found to be 5.11 kg kW,1 h,1. Copyright © 2006 John Wiley & Sons, Ltd. [source] A distributed networking system for multimedia Internet access service using ATM over ADSLINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2004Daniel Won-Kyu Hong This paper proposes a distributed networking system architecture for Internet-access service provision using ATM over xDSL technology. We describe the hierarchical network model in deploying ADSL services across the ATM access networks, which can easily accommodate the explosive growth of ADSL subscribers in the future. In addition, this paper describes the distributed networking system and its capability to provide a systemic network management using the principal networking concepts of service ordering, addressing, routing, adaptation and switching. All of the networking system components with CORBA objects in favor of the distribution and location transparency are defined and described using the CORBA interface description language (IDL) for commonality. Lastly, we present its implementation and operation in Korea Telecom.,Copyright © 2004 John Wiley & Sons, Ltd. [source] H, fuzzy control design of discrete-time nonlinear active fault-tolerant control systemsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10 2009Huai-Ning Wu Abstract This paper is concerned with the problem of H, fuzzy controller synthesis for a class of discrete-time nonlinear active fault-tolerant control systems (AFTCSs) in a stochastic setting. The Takagi and Sugeno (T,S) fuzzy model is employed to exactly represent a nonlinear AFTCS. For this AFTCS, two random processes with Markovian transition characteristics are introduced to model the failure process of system components and the fault detection and isolation (FDI) decision process used to reconfigure the control law, respectively. The random behavior of the FDI process is conditioned on the state of the failure process. A non-parallel distributed compensation (non-PDC) scheme is adopted for the design of the fault-tolerant control laws. The resulting closed-loop fuzzy system is the one with two Markovian jump parameters. Based on a stochastic fuzzy Lyapunov function (FLF), sufficient conditions for the stochastic stability and H, disturbance attenuation of the closed-loop fuzzy system are first derived. A linear matrix inequality (LMI) approach to the fuzzy control design is then developed. Moreover, a suboptimal fault-tolerant H, fuzzy controller is given in the sense of minimizing the level of disturbance attenuation. Finally, a simulation example is presented to illustrate the effectiveness of the proposed design method. Copyright © 2008 John Wiley & Sons, Ltd. [source] PROTEIN PROFILE CHANGES IN ACID ADAPTED LISTERIA MONOCYTOGENES EXHIBITING CROSS-PROTECTION AGAINST AN ACTIVATED LACTOPEROXIDASE SYSTEM IN TRYPTIC SOY BROTHJOURNAL OF FOOD SAFETY, Issue 1 2000SADHANA RAVISHANKAR ABSTRACT Foodborne pathogens often tolerate and survive environmental stress conditions including extreme acidity to varying degrees. One possible reason for this survival may be the production of protective stress proteins during acid shock (ASR) and/or tolerance (ATR) responses. The ASR and ATR of Listeria monocytogenes strains V7, V37 and CA in tryptic soy broth without dextrose acidified with lactic acid were studied. Possible cross-protection of acid adapted cells against an activated lactoperoxidase system was also determined. The strains were either directly challenged at pH 4.0 and 3.5 to study their ASR or initially adapted at pH 5.5 for the equivalent of 1 generation before challenging at pH 4.0 and 3.5 to study their ATR. Adapted and nonadapted cells were challenged at pH 4.5 with or without an activated lactoperoxidase system. In all cases viability was determined by enumeration over a period of 24 or 48 h after challenge and the production of stress proteins analyzed by 2-dimensional gel electrophoresis. While there were some differences in the survival responses for each strain, the acid adapted cells of each strain survived to a greater degree than nonadapted cells at both pH 4.0 (at least 10 fold at 24 h) and pH 3.5 (at least 1000 fold at 6 h) but not at pH 4.5. The acid adapted cells exposed to the lactoperoxidase system survived better (at least 5-fold) than their nonadapted counterparts for all 3 strains at 24 and 48 h. The 2-dimensional gel analysis for all 3 strains showed that the adapted and nonadapted cells underwent a change in their physiology, (at pH 4.0 compared to the control at pH 7.0; at pH 4.5 with the addition of lactoperoxidase system components) in that there was induction as well as repression of several proteins. [source] Anatomical Markers of Activity in Neuroendocrine Systems: Are we all ,Fos-ed out'?JOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2002G. E. Hoffman Abstract It has now been nearly 15 years since the immediate early gene, c -fos, and its protein product, Fos, were introduced as tools for determining activity changes within neurones of the nervous system. In the ensuing years, this approach was applied to neuroendocrine study with success. With it have come advances in our understanding of which neuroendocrine neurones respond to various stimuli and how other central nervous system components interact with neuroendocrine neurones. Use of combined tract-tracing approaches, as well as double-labelling for Fos and transmitter markers, have added to characterization of neuroendocrine circuits. The delineation of the signal transduction cascades that induce Fos expression has led to establishment of the relationship between neurone firing and Fos expression. Importantly, we can now appreciate that Fos expression is often, but not always, associated with increased neuronal firing and vice versa. There are remaining gaps in our understanding of Fos in the nervous system. To date, knowledge of what Fos does after it is expressed is still limited. The transience of Fos expression after stimulation (especially if the stimulus is persistent) complicates design of experiments to assess the function of Fos and makes Fos of little value as a marker for long-term changes in neurone activity. In this regard, alternative approaches must be sought. Useful alternative approaches employed to date to monitor neuronal changes in activity include examination of (i) signal transduction intermediates (e.g. phosphorylated CREB); (ii) transcriptional/translational intermediates (e.g. heteronuclear RNA, messenger RNA (mRNA), prohormones); and (iii) receptor translocation. Another capitalizes on the fact that many neuroendocrine systems show striking stimulus-transcription coupling in the regulation of their transmitter or its synthetic enzymes. Together, as we move into the 21st Century, the use of multiple approaches to study activity within neuroendocrine systems will further our understanding of these important systems. [source] USE OF THE DELPHI METHOD IN RESOLVING COMPLEX WATER RESOURCES ISSUES,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2003Jonathan G. Taylor ABSTRACT: The tri-state river basins, shared by Georgia, Alabama, and Florida, are being modeled by the U.S. Fish and Wildlife Service and the U.S. Army Corps of Engineers to help facilitate agreement in an acrimonious water dispute among these different state governments. Modeling of such basin reservoir operations requires parallel understanding of several river system components: hydropower production, flood control, municipal and industrial water use, navigation, and reservoir fisheries requirements. The Delphi method, using repetitive surveying of experts, was applied to determine fisheries' water and lake-level requirements on 25 reservoirs in these interstate basins. The Delphi technique allowed the needs and requirements of fish populations to be brought into the modeling effort on equal footing with other water supply and demand components. When the subject matter is concisely defined and limited, this technique can rapidly assess expert opinion on any natural resource issue, and even move expert opinion toward greater agreement. [source] Ultrastructural identification of peripheral myelin proteins by a pre-embedding immunogold labeling methodJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003Marie-Hélène Canron Abstract Ultrastructural immunolabeling of peripheral nervous system components is an important tool to study the relation between structure and function. Owing to the scarcity of certain antigens and the dense structure of the peripheral nerve, a pre-embedding technique is likely appropriate. After several investigations on procedures for pre-embedding immunolabeling, we propose a method that offers a good compromise between detection of antigenic sites and preservation of morphology at the ultrastructural level, and that is easy to use and suitable for investigations on peripheral nerve biopsies from humans. Pre-fixation by immersion in paraformaldehyde/glutaraldehyde is necessary to stabilize the ultrastructure. Then, ultrasmall gold particles with silver enhancement are advised. Antibodies against myelin protein zero and myelin basic protein were chosen for demonstration. The same technique was applied to localize a 35 kDa myelin protein. [source] Assessment of the role of heparan sulfate in high molecular weight kininogen binding to human umbilical vein endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2003L.P. Fernando Summary., The assembly and activation of the kinin forming system components on human umbilical vein endothelial cells (HUVEC) have been studied in great detail. Proteins such as gC1qR, cytokeratin-1 and u-PAR have been identified to be responsible for Zn2+ -dependent binding of high molecular weight kininogen (HK) to HUVEC. Heparan sulfate has also been shown to have a major role in Zn2+ -dependent binding of HK to the endothelial cell line, Ea.hy 926. In this study, we have analyzed the possible contribution of heparan sulfate to high molecular weight kininogen binding to HUVEC using multiple approaches. The presence of heparan sulfate on HUVEC was analyzed by staining with an antibody specific for heparan sulfate. Incubation of the cells with bacterial heparinases removed the heparan sulfate from the cell surface to the level seen with a control antibody, however, the Zn2+ -dependent binding of HK was not affected. Further, blocking of heparan sulfate with a specific antibody to heparan sulfate even after digestion with heparinases did not reduce HK binding whereas antibodies to the proteins gC1qR and cytokeratin-1 consistently reduced the binding of HK to the endothelial cells. The binding intensities of FITC-labeled HK were similar in heparinase-treated and -untreated HUVEC. The rate of kallikrein formation by the assembly of factor XII, HK and PK were similar in both heparinase-treated and non-treated HUVEC. All of these data indicate that heparan sulfate does not contribute significantly to HK binding to HUVEC. [source] Modeling Studies of the Phase Behavior of Monomer/Polymer/Disk CompositesMACROMOLECULAR THEORY AND SIMULATIONS, Issue 6 2008Francisco Torrens Abstract The model developed by Balazs et al. to explain the phase behavior of polymer/clay composites is extended to monomer/polymer/clay composites, obtaining an expression for the free energy of a monomer/polymer/thin-disk mixture. By minimizing the free energy and calculating the chemical potentials of the three system components, phase diagrams for the monomer/disk and monomer/polymer/disk mixtures are contructed. Through the evolution and comparison of these diagrams, the effects of nanodisk size, polymer molecular mass and interaction parameters (temperature) on mixture stability and attained morphology are then studied. [source] Set theoretic formulation of performance reliability of multiple response time-variant systems due to degradations in system componentsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2007Young Kap Son Abstract This paper presents a design stage method for assessing performance reliability of systems with multiple time-variant responses due to component degradation. Herein the system component degradation profiles over time are assumed to be known and the degradation of the system is related to component degradation using mechanistic models. Selected performance measures (e.g. responses) are related to their critical levels by time-dependent limit-state functions. System failure is defined as the non-conformance of any response and unions of the multiple failure regions are required. For discrete time, set theory establishes the minimum union size needed to identify a true incremental failure region. A cumulative failure distribution function is built by summing incremental failure probabilities. A practical implementation of the theory can be manifest by approximating the probability of the unions by second-order bounds. Further, for numerical efficiency probabilities are evaluated by first-order reliability methods (FORM). The presented method is quite different from Monte Carlo sampling methods. The proposed method can be used to assess mean and tolerance design through simultaneous evaluation of quality and performance reliability. The work herein sets the foundation for an optimization method to control both quality and performance reliability and thus, for example, estimate warranty costs and product recall. An example from power engineering shows the details of the proposed method and the potential of the approach. Copyright © 2006 John Wiley & Sons, Ltd. [source] A new approach to solving problems of multi-state system reliability optimizationQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2001Gregory Levitin Abstract Usually engineers try to achieve the required reliability level with minimal cost. The problem of total investment cost minimization, subject to reliability constraints, is well known as the reliability optimization problem. When applied to multi-state systems (MSS), the system has many performance levels, and reliability is considered as a measure of the ability of the system to meet the demand (required performance). In this case, the outage effect will be essentially different for units with different performance rate. Therefore, the performance of system components, as well as the demand, should be taken into account. In this paper, we present a technique for solving a family of MSS reliability optimization problems, such as structure optimization, optimal expansion, maintenance optimization and optimal multistage modernization. This technique combines a universal generating function (UGF) method used for fast reliability estimation of MSS and a genetic algorithm (GA) used as an optimization engine. The UGF method provides the ability to estimate relatively quickly different MSS reliability indices for series-parallel and bridge structures. It can be applied to MSS with different physical nature of system performance measure. The GA is a robust, universal optimization tool that uses only estimates of solution quality to determine the direction of search. Copyright © 2001 John Wiley & Sons, Ltd. [source] Groundwater circulation well operation using wind turbine,generated energyREMEDIATION, Issue 3 2008Ron Gallagher An investigation was conducted regarding the potential economic benefits associated with using a wind turbine to power a groundwater circulation well (GCW) at the former Nebraska Ordnance Plant Superfund site. The first phase of the investigation used a 10-kilowatt-rated grid inter-tie wind turbine to partially offset the purchase of electricity from the utility company. The second phase consisted of the conversion of the grid inter-tie system to an off-grid system that stored energy using batteries. During the second phase, the GCW system was operated using either wind turbine power or utility power, and the other system components were operated using utility power. The study showed that a significant amount of power purchased from the utility company was used for nonessential purposes (other than operating the GCW pump and essential treatment components). One nonessential power consumer was the continuous heating of the equipment shelter for operator comfort during their 10-minute visit every few days. Wind-turbine reduction in utility power consumption was evaluated, and the operating time of a hypothetical system powered solely by the wind turbine was compared to the actual GCW operating time. This study indicates that retrofitting this GCW system did not economically offset power costs from a cheap, readily available grid system. Perhaps at a remote location with a more energy-efficient design and operation and the inclusion of green power benefits (in some monetary amount), the wind turbine results will be more favorable. The study of a renewable energy application at the site highlighted opportunities for significant electrical energy savings regardless of the source of the electricity. © 2008 Wiley Periodicals, Inc. [source] Three-dimensional anatomy of the conduction system of the early embryonic rabbit heartTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2006Florence Rothenberg Abstract The complete embryonic cardiac conduction system is difficult to view in three dimensions, primarily because there has not been a marker of all segments of the normal system throughout all stages of development. Imaging of the conduction system components within the atria has been particularly controversial because different markers reveal different pathways that may or may not represent conduction system components. The conduction system of the adult and embryonic rabbit, however, can be labeled in its entirety with the neurofilament marker, NF-160. The conduction system of rabbit embryos at several stages of development spanning cardiac septation was therefore investigated. Optical mapping of the electrical signature of the conduction system previously revealed a close correlation between the cardiac activation patterns and the anatomy as shown by serial sections. The 3D relationship between the components of the conduction system could only be inferred from the 2D sections. The sections were consequently reconstructed using a commercial software program (AutoQuant). This is the first demonstration of the three-dimensional complete normal rabbit embryonic cardiac conduction system at several stages of development. © 2005 Wiley-Liss, Inc. [source] Improving the Quality of Workers' Compensation Health Care Delivery: The Washington State Occupational Health Services ProjectTHE MILBANK QUARTERLY, Issue 1 2001Thomas M. Wickizer Researchers and health policy analysts in Washington State set out to determine the extent to which administrative process changes and delivery system interventions within workers' compensation affect quality and health outcomes for injured workers. This research included a pilot project to study the effects of providing occupationally focused health care through managed care arrangements on health outcomes, worker and employer satisfaction, and medical and disability costs. Based on the results, a new initiative was developed to incorporate several key delivery system components. The Washington State experience in developing a quality improvement initiative may have relevance for health care clinicians, administrators, policymakers, and researchers engaged in similar pursuits within the general medical care arena. [source] The Aachen MiniHLM,A Miniaturized Heart-Lung Machine for Neonates With an Integrated Rotary Blood PumpARTIFICIAL ORGANS, Issue 9 2010Jutta Arens Abstract The operation of congenital heart defects in neonates often requires the use of heart-lung machines (HLMs) to provide perfusion and oxygenation. This is prevalently followed by serious complications inter alia caused by hemodilution and extrinsic blood contact surfaces. Thus, one goal of developing a HLM for neonates is the reduction of priming volume and contact surface. The currently available systems offer reasonable priming volumes for oxygenators, reservoirs, etc. However, the necessary tubing system contains the highest volumes within the whole system. This is due to the use of roller pumps; hence, the resulting placement of the complete HLM is between 1 and 2 m away from the operating table due to connective tubing between the components. Therefore, we pursued a novel approach for a miniaturized HLM (MiniHLM) by integrating all major system components in one single device. In particular, the MiniHLM is a HLM with the rotary blood pump centrically integrated into the oxygenator and a heat exchanger integrated into the cardiotomy reservoir which is directly connected to the pump inlet. Thus, tubing is only necessary between the patient and MiniHLM. A total priming volume of 102 mL (including arterial filter and a/v line) could be achieved. To validate the overall concept and the specific design we conducted several in vitro and in vivo test series. All tests confirm the novel concept of the MiniHLM. Its low priming volume and blood contact surface may significantly reduce known complications related to cardiopulmonary bypass in neonates (e.g., inflammatory reaction and capillary leak syndrome). [source] Predicting potential impacts of environmental flows on weedy riparian vegetation of the Hawkesbury,Nepean River, south-eastern AustraliaAUSTRAL ECOLOGY, Issue 5 2000Jocelyn Howell Abstract Remnants of native riparian vegetation on the floodplain of the Hawkesbury,Nepean River near Sydney, have significant conservation value, but contain a large component of weeds (i.e. exotic species that have become naturalized). A proposal for the introduction of environmental flows required an assessment of potential impacts on 242 native and 128 exotic species recorded along 215 km of the river. The likely effects of frequency, season, depth and duration of inundation were considered in relation to habitat, dispersal season and tolerance to waterlogging. Overseas studies provided only limited information applicable to the study area; however, comparisons with similarly highly modified riparian habitats in New Zealand were instructive. Depth and season of inundation appear to be the variables with the greatest potential for differential effects on weeds and native plants. Because of likely spread of propagules and enhancement of growth under the present nutrient-enriched conditions, environmental flows that would cause more frequent flooding to higher levels of the riparian zone were judged to be of more benefit to weed species than native species, unless supported by bushland management including weeding. Predictions were limited by incomplete data on Hawkesbury,Nepean species, but two types of environmental flow were judged to be potentially beneficial for native water-edge plants, and worth testing and monitoring: first, flows that maintain continuous low-level flow in the river, and second, higher level environmental flows restricted to the river-edge habitat in autumn (the season in which a greater proportion of native species than weed species are known to disperse propagules). In summary, the presence of environmental weeds in riparian vegetation constrain the potential for environmental flows to improve river health. However, with ongoing monitoring, careful choice of water level and season of flow may lead to environmental flows that add to our knowledge, and benefit riparian vegetation along with other river system components. [source] Building secure products and solutionsBELL LABS TECHNICAL JOURNAL, Issue 3 2007Ashok K. Gupta Many security vulnerabilities in current information technology (IT) solutions and products are the result of a piecemeal "strap-on" security approach. The inclusion of many security add-ons, such as firewalls, antivirus software, intrusion detection systems (IDSs), and intrusion prevention systems (IPSs), may imply that the security objectives were an afterthought, not adequately defined initially, or that the required security objectives were never met by the individual system components. In fact, a "grounds-up" approach to security, where each component is individually secure, in a defined network deployment scenario helps meet the need of minimal risk exposure. Security should not be bolted on; rather, it should be the prime consideration from the beginning and throughout the entire lifecycle,from concept to deployment and ongoing operation for each product in the solution. Given the ever-increasing sophistication of attacks, developing and monitoring secure products have become increasingly difficult. Despite the wide-scale awareness of common security flaws in software products, e.g., buffer overflows, resource exhaustion, and structured query language (SQL) injection, the same flaws continue to exist in some of the current products. The objective of this paper is to introduce a technology-agnostic approach to integrating security into the product development lifecycle. The approach leverages the Bell Labs Security Framework, the foundation of the International Telecommunication Union, Telecommunication Standardization Sector (ITU-T) X.805 global standard. Building this framework into the product lifecycle supports the goal of realizing secure products. The security framework can be applied to any product domain to facilitate security requirements analysis and the development of usable tools such as checklists, guidelines, and security policies. The application of Bell Labs Security Framework concepts and its use in the development of secure products are illustrated using the example of a centrally managed firewall product. © 2007 Alcatel-Lucent. [source] | |||||||||||||||||||||||||||||||