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Supply System (supply + system)

Distribution by Scientific Domains

Engineering	40%
Medical Sciences	16%
Humanities and Social Sciences	14%
Business, Economics, Finance and Accounting	11%
Life Sciences	7%
Chemistry	4%
2 Other Domains	8%

Kinds of Supply System

water supply system

Selected Abstracts

Incorporating variable source area hydrology into a curve-number-based watershed model

HYDROLOGICAL PROCESSES, Issue 25 2007
Elliot M. Schneiderman
Abstract Many water quality models use some form of the curve number (CN) equation developed by the Soil Conservation Service (SCS; U.S. Depart of Agriculture) to predict storm runoff from watersheds based on an infiltration-excess response to rainfall. However, in humid, well-vegetated areas with shallow soils, such as in the northeastern USA, the predominant runoff generating mechanism is saturation-excess on variable source areas (VSAs). We reconceptualized the SCS,CN equation for VSAs, and incorporated it into the General Watershed Loading Function (GWLF) model. The new version of GWLF, named the Variable Source Loading Function (VSLF) model, simulates the watershed runoff response to rainfall using the standard SCS,CN equation, but spatially distributes the runoff response according to a soil wetness index. We spatially validated VSLF runoff predictions and compared VSLF to GWLF for a subwatershed of the New York City Water Supply System. The spatial distribution of runoff from VSLF is more physically realistic than the estimates from GWLF. This has important consequences for water quality modeling, and for the use of models to evaluate and guide watershed management, because correctly predicting the coincidence of runoff generation and pollutant sources is critical to simulating non-point source (NPS) pollution transported by runoff. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Development of Multiple Power Quality Supply System,

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2010
Keiichi Hirose Member
Abstract This paper describes the characteristics and performances of a multiple power quality supply system (MPQSS), which consists of power electronics-based voltage compensators and three types of distributed generators (DGs). Its original concept of a future power delivery system having different service levels to meet each customer or load requirement at the same time was proposed as Flexible, Reliable, and Intelligent Electrical eNergy Delivery System (FRIENDS). The effectiveness of the developed power system was measured during an actual field demonstration conducted in 2007 by the New Energy and Industrial Technology Development Organization (NEDO), Sendai, Japan. Its effectiveness in feeding four classes of alternative current (AC) and one of direct current (DC) power while meeting various customer requirements was confirmed. Some sets of test data and an analysis using the data indicate that the developed system meets all the requirements for DG-related plants and has additional benefits. The power system maintains voltage and frequency conditions without interruption in the every state, grid interconnection, islanding, and backup modes. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

Structural Features of the NAD-Dependent In Situ Retinoic Acid Supply System in Esophageal Mucosa

ALCOHOLISM, Issue 2010
Hirokazu Yokoyama
Background:, We previously reported that an NAD-dependent in situ retinoic acid supply system, which comprises some isoforms of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) and provides retinoic acid from retinol via a 2-step oxidation process, exists in the rat esophagus. Herein, their isoforms responsible for the pathway and its localization in the rat esophagus was examined. Methods:, The expressions of mRNAs of various isoforms of ADH and ALDH were examined in the fraction mainly comprising mucosal layer of the rat esophagus by RT-PCR. Expression levels of Class IV ADH and ALDH 1A1 were compared between the fractions and that mainly comprising muscle layer of the rat esophagus by quantitative PCR. The catalytic activities producing retinoic acid from retinal were compared between the 2 fractions and its optimum pH was also determined. Results:, Classes I, III, and IV ADHs and ALDHs 1A1 and 3A1 were predominant isoforms in the rat esophageal mucosa. The expression levels of mRNA of Class IV ADH and ALDH 3A1 were significantly higher in the mucosal than in the muscle layer. Consistently, the catalytic activities producing retinoic acid from retinal were significantly higher in the former than the latter. The optimum pH of the process was 9.0. Conclusions:, Considering the affinities for retinol and retinal of ADHs and ALDHs expressed in the rat esophagus, the NAD-dependent in situ retinoic acid supply system in the rat esophagus is thought to comprise Class IV ADH and ALDH 1A1. In the rat esophagus, the system exists predominantly in the mucosal layer. [source]

An Improvised Oxygen Supply System for Pandemic and Disaster Use

ACADEMIC EMERGENCY MEDICINE, Issue 6 2009
Charles M. Little DO
Abstract Background:, Current disaster planning for pandemic influenza anticipates overwhelming numbers of patients in need of hospitalization. The anticipated use of extra, or "surge," beds is common in both hospital and community disaster response planning. In a pandemic of respiratory illness, supplemental oxygen will be a life-saving intervention. There are currently few options to provide these proposed surge beds with the necessary oxygen. Objectives:, A method of providing an improvised oxygen delivery system for use in a disaster was developed and tested. This system was designed to use readily available commercial materials to assemble an oxygen delivery system. Methods:, The study consisted of a laboratory design, assembly, and testing of an improvised oxygen system. Results:, A liquid oxygen (LOX) Dewar container was used to supply oxygen systems built from inexpensive commercially available plastic tubing and fittings. The system will drive ventilators without significant pressure drop or ventilator malfunction. The final developed system will supply 30 patients with up to 6 L/min (l pm) oxygen each by nasal cannula from a single oxygen Dewar. Conclusions:, An improvised system to deliver oxygen for patient beds or ventilator use can be easily assembled in the event of a disaster. This could be life-saving in the event of a pandemic of respiratory illness. [source]

Protecting the Nation's Critical Infrastructure: The Vulnerability of U.S. Water Supply Systems

JOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2000
Robert M. Clark
Terrorism in the United States was not considered a serious threat until the second half of the 1990s. However, recent attacks both at home and abroad have forced government planners to consider the possibility that critical elements of the U.S. infrastructure might in fact be vulnerable to terrorism. The potential for chemical or biological contamination of water supply systems exists along with the possibility that such systems might be sabotaged. This article reviews the threat of biological and chemical compounds in relation to the characteristics of water supply systems. Vulnerability of such systems to terrorist attacks is examined, as well as possible physical and chemical countermeasures that could be applied. A case study is presented of an accidental contamination event that illustrates the difficulty of tracking such events in a drinking water system. It can be concluded that municipal water supplies are vulnerable. However, appropriate physical planning of such systems, including contingency back-up with separate water lines for emergencies, coupled with proactive monitoring, will significantly increase security in the face of possible terrorist attacks. [source]

Regional industrial recycling network in energy supply,the case of Joensuu city, Finland

CORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 3 2002
Jouni Korhonen
Industrial recycling networks offer an example of the practical application of some of the industrial ecology (IE) principles. In the industrial ecosystem and eco-industrial park approaches the material cycles and energy cascades in a natural ecosystem serve as the metaphoric vision for a local/regional industrial system in which waste material and waste (residual) energy are utilized through cooperation between the actors in the system. In this paper, a local/regional recycling network scenario is presented with the energy supply system of the city of Joensuu in Finland. The conditions of success include the co-production of heat and electricity (heat and power, CHP), waste energy utilization for industrial steam and renewable flow use as fuel. Some difficulties in the industrial ecosystem-type development of the system are discussed. Methodological suggestions for industrial ecosystem and eco-industrial park case studies are considered and the experience from this Finnish case is discussed in terms of wider application of IE in local/regional economic energy systems. For future research on the theme, it is suggested that regional industrial ecology may benefit from regional economics theory and, vice versa, regional economics theory may find a new area of application in regional industrial ecology. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment. [source]

Decision Making in a Standby Service System,

DECISION SCIENCES, Issue 3 2000
H. V. Ravinder
A standby service option allows a firm to lower its risk of not having sufficient capacity to satisfy demand without investing in additional capacity. Standby service options currently exist in the natural gas, electric, and water utility industries. Firms seeking standby service are typically large industrial or institutional organizations that, due to unexpectedly high demand or interruptions in their own supply system, look to a public utility to supplement their requirements. Typically, the firm pays the utility a reservation fee based on a nominated volume and a consumption charge based on the volume actually taken. In this paper, a single-period model is developed and optimized with respect to the amount of standby capacity a firm should reserve. Expressions for the mean and variance of the supplier's aggregate standby demand distribution are developed. A procedure for computing the level of capacity needed to safely meet its standby obligations is presented. Numerical results suggest that the standby supplier can safely meet its standby demand with a capacity that is generally between 20 to 50% of the aggregate nominated volume. [source]

A recursive decomposition algorithm for network seismic reliability evaluation

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2002
Jie Li
Abstract A new probabilistic analytical approach to evaluate seismic system reliability of large lifeline systems is presented in this paper. The algorithm takes the shortest path from the source to the terminal of a node weight or edge weight network as decomposition policy, using the Boolean laws of set operation and probabilistic operation principal, a recursive decomposition process then could be constructed. For a general weight network, the modified Torrieri method (NTR/T method) is introduced to combine with the suggested algorithm. Therefore, the recursive decomposition algorithm may be applied to evaluate the seismic reliability of general lifeline systems. A series of case studies, including a practical district electric power network system and a large urban water supply system, show that the suggested algorithm supplies a useful probabilistic analysis means for the seismic reliability evaluation of large lifeline systems. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Quality, imagery and marketing: producer perspectives on quality products and services in the lagging rural regions of the European Union

GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 1 2001
Brian Ilbery
A range of factors, including consumer concerns about food safety, the growing popularity of rural tourism and policy initiatives to promote endogenous rural development, is converging to promote a relocalization of food production and service provision, especially in those regions marginalized by the globalization of the food supply system. The recent outbreak of foot and mouth disease in the UK has starkly illustrated the fragility of localized systems which depend heavily on consumers travelling to them. Within such a context, the importance of successful marketing strategies has become even more apparent. This paper reports on a questionnaire survey which investigated promotional and marketing strategies among a diverse range of producers and service providers in marginal agricultural areas of the EU. The findings suggest that many producers are situated towards the "formal" end of a marketing continuum, whereby ability to promote quality products and services (QPS) lies with a range of intermediaries. This raises doubts about the future economic benefits of QPS, should current marketing structures persist. The discussion offers critical reflections on interdisciplinary and international research of this nature, and advocates further theoretical and methodological development in order to explore in more depth many of the aspects raised in this exploratory investigation. [source]

Seroprevalence of Helicobacter pylori Infection Among Schoolchildren and Teachers in Taiwan

HELICOBACTER, Issue 3 2007
Ding-Bang Lin
Abstract Background:,Helicobacter pylori are associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection of H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life. Materials and Methods:, To examine the epidemiologic characteristics of H. pylori infection among schoolchildren in central Taiwan, a community-based survey was carried out using stratified sampling in 10 elementary schools and three junior high schools including students and theirs teachers. Serum specimens of 1950 healthy schoolchildren (aged 9,15 years old) and 253 teachers who were randomly sampled were screened for the H. pylori antibodies by enzyme-linked immunosorbent assay. Statistical analysis was performed by using the spss for Windows statistical software system. Results:, A total of 332 subjects were H. pylori antibodies positive, giving an overall prevalence of 15.1%. The age-specific seropositive rates were 11.0% in 9,12 years age group, 12.3% in 13,15 years age group, and 45.1% in the teacher group. The older the age, the higher the seroprevalence (OR = 11.53; 95% CI = 6.73,19.74; p < .001 for children vs. teachers). There was no difference in the seroprevalence of H. pylori infection by gender, ethnicity, geographical area, socioeconomic level, parental education, sibship size, family members, and source of drinking water. Conclusion:, The teachers had a much higher prevalence of H. pylori antibodies. The finding suggests that these teachers (adults) might be infected in their early childhood and implies that the poor environmental and hygienic conditions might be responsible for it. It seemed that poor water supply system, sewage disposal, and other environmental hygiene in adult might play some roles in H. pylori infection in Taiwan (before early 1980s). [source]

Development of Multiple Power Quality Supply System,

A modularized framework for solving an economic,environmental power generation mix problem

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2004
Haoxiang Xia
Abstract This paper presents a modularized simulation modelling framework for evaluating the impacts on economic cost and CO2 emissions resulting from the introduction of a solid oxide fuel cell (SOFC) system into the existing mix of centralized power generation technologies in Japan. The framework is comprised of three parts: a dual-objective linear programming model that solves the generation best-mix problem for the existing power generation technologies; a nonlinear SOFC system model in which the economic cost and CO2 emissions by the SOFC system can be calculated; and the Queuing Multi-Objective Optimizer (QMOO), a multi-objective evolutionary algorithm (MOEA) developed at the EPFL in Switzerland as the overall optimizer of the combined power supply system. Thus, the framework integrates an evolutionary algorithm that is more suitable for handling nonlinearities with a calculus-based method that is more efficient in solving linear programming problems. Simulation experiments show that the framework is successful in solving the stated problem. Moreover, the three components of the modularized framework can be interconnected through a platform-independent model integration environment. As a result, the framework is flexible and scalable, and can potentially be modified and/or integrated with other models to study more complex problems. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Modelling and optimization of district heating and industrial energy system,an approach to a locally deregulated heat market

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2004
Alemayehu Gebremedhin
Abstract Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub-systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Access to essential drugs in Guyana: a public health challenge,,

INTERNATIONAL JOURNAL OF HEALTH PLANNING AND MANAGEMENT, Issue 1 2010
Enrique Seoane-Vazquez
Abstract Guyana's pharmaceutical sector faces major challenges that limit access to essential drugs. This study analyzes Guyana's drug policy and regulation, public financing, and drug procurement and delivery. The study also identifies main barriers to drug access and proposes alternatives to strengthen the country's public health functions. Data were collected from the country's regulatory agencies, public procurement agency, pharmacies, wholesalers, and pharmaceutical companies. The information was supplemented with interviews with a convenient sample of Guyanese health authorities and stakeholders. Data were also compiled from scientific databases, and web pages of the country's Ministries of Health, Commerce and Finance, the Bureau of Statistics, and international organizations. Major barriers to drug access include: (1) lack of national drug policy and regulation, and limited role of the regulatory authority; (2) inefficient drug selection and irrational drug use; (3) insufficient financial resources and lack of drug pricing policy; (4) inefficient planning and managing public supply system; (5) deficient epidemiological and information systems; and (6) inadequate infrastructures and human resources shortage. Improving drug access in Guyana requires the strengthening of the country's public health functions and the implementation of a national drug policy and pricing policy, streamlining the drug financing, procurement, and planning and managing drug supply; and adequate infrastructures and human resources. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Optimizing in-kind drug donations for Tanzania,a case study

INTERNATIONAL JOURNAL OF HEALTH PLANNING AND MANAGEMENT, Issue 4 2008
Gaby Gehler Mariacher
Abstract A questionnaire survey (QS) among stakeholders in Tanzania had shown that in-kind drug donations (DDs) are important to boost the drug supply system. Major problems were their insufficient quantity for sustainable treatment and the discrepancy between the needs of the recipients and the donors' supply. Objectives in this study were to discuss these findings and to learn from key informants (KIs) how to improve the DD process. Data were collected through KI interviews in 2001/2002. A 30% gap in drug supply has to be bridged by DDs. KIs confirmed the importance of the World Health Organisation and Tanzanian DD guidelines as a tool for good donation practice and emphasized the role of the government in their implementation. They requested that donors meet the recipient country's regulatory requirements. In contrast to QS respondents, KIs did not view DD quality as a minor problem, and proposed that DD quality should be adapted to the national quality assurance procedures. DD processes could be improved through (a) effective implementation of DD guidelines as an aid for decision-making and for quality assurance, (b) availability of data to improve communication between donors and recipients, (c) transparency between recipients and donors and (d) clearly defined accountability. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Lead Firms and Competition in ,Bi-polar' Commodity Chains: Grinders and Branders in the Global Cocoa-chocolate Industry

JOURNAL OF AGRARIAN CHANGE, Issue 2 2002
Niels FoldArticle first published online: 16 DEC 200
Like most global agro-industrial commodity chains today, the global cocoa - chocolate industry is buyer-driven. However, the chain is characterized by the lead role of a few transnational companies in two different segments: the grinders (processors of cocoa)and the branders (manufacturers of chocolate), a structural pattern identified in other so-called turn-key industries consisting of contract manufacturers and brand-name firms. The paper examines two important spatial sub-systems of the chain: the national cocoa bean supply system in Ghana and the regional cocoa trading-storing-grinding complex in the Zaanstreek, Amsterdam. The structural patterns and relationships in these sub-systems suggest that the dynamics of ,bi-polar' buyer-driven chains is best comprehended in terms of various types of containment strategies of the leadfirms, i.e. efforts to defend and improve their positions on the global market by creating competition among their suppliers and expanding their customers. [source]

Bacterial population dynamics and community structure in a pharmaceutical manufacturing water supply system determined by real-time PCR and PCR-denaturing gradient gel electrophoresis

JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004
M. Kawai
Abstract Aims:, To control bacteria in the pharmaceutical water supply system. Methods and Results:, Bacteria were enumerated by conventional culture method and fluorescent vital staining. Activated carbon treatment and storage in a tank provided favourable environments for bacterial growth. The bacterial population of the water in both the post-activated carbon treatment and the tank was analysed by denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rDNA fragments including V6, -7, and -8 regions. The bacterial community structure in activated carbon treated water was stable throughout the year. Several kinds of bacteria such as genus Aquaspirillum and Methylobacterium were found in the water after activated carbon treatment. The bacterial community structure was changed and other bacteria such as mycobacteria were detected after storage. Mycobacteria were quantified in water samples using real-time PCR targeting the 16S rDNA gene. Mycobacteria were also detected in tap water and their number was increased 103,104 -fold higher after storage. Conclusion:, These data suggest the importance of culture-independent methods for quality control of water used in pharmaceutical manufacturing. Significance and Impact of the Study:, Critical steps and specified bacteria that should be controlled in the water supply system were recognized by culture-independent methods. These data will enable effective control of water used in the pharmaceutical industry. [source]

Optimization of energy usage for fleet-wide power generating system under carbon mitigation options

AICHE JOURNAL, Issue 12 2009
A. Elkamel
Abstract This article presents a fleet-wide model for energy planning that can be used to determine the optimal structure necessary to meet a given CO2 reduction target while maintaining or enhancing power to the grid. The model incorporates power generation as well as CO2 emissions from a fleet of generating stations (hydroelectric, fossil fuel, nuclear, and wind). The model is formulated as a mixed integer program and is used to optimize an existing fleet as well as recommend new additional generating stations, carbon capture and storage, and retrofit actions to meet a CO2 reduction target and electricity demand at a minimum overall cost. The model was applied to the energy supply system operated by Ontario power generation (OPG) for the province of Ontario, Canada. In 2002, OPG operated 79 electricity generating stations; 5 are fueled with coal (with a total of 23 boilers), 1 by natural gas (4 boilers), 3 nuclear, 69 hydroelectric and 1 wind turbine generating a total of 115.8 TWh. No CO2 capture process existed at any OPG power plant; about 36.7 million tonnes of CO2 was emitted in 2002, mainly from fossil fuel power plants. Four electricity demand scenarios were considered over a span of 10 years and for each case the size of new power generation capacity with and without capture was obtained. Six supplemental electricity generating technologies have been allowed for: subcritical pulverized coal-fired (PC), PC with carbon capture (PC+CCS), integrated gasification combined cycle (IGCC), IGCC with carbon capture (IGCC+CCS), natural gas combined cycle (NGCC), and NGCC with carbon capture (NGCC+CCS). The optimization results showed that fuel balancing alone can contribute to the reduction of CO2 emissions by only 3% and a slight, 1.6%, reduction in the cost of electricity compared to a calculated base case. It was found that a 20% CO2 reduction at current electricity demand could be achieved by implementing fuel balancing and switching 8 out of 23 coal-fired boilers to natural gas. However, as demand increases, more coal-fired boilers needed to be switched to natural gas as well as the building of new NGCC and NGCC+CCS for replacing the aging coal-fired power plants. To achieve a 40% CO2 reduction at 1.0% demand growth rate, four new plants (2 NGCC, 2 NGCC+CCS) as well as carbon capture processes needed to be built. If greater than 60% CO2 reductions are required, NGCC, NGCC+CCS, and IGCC+CCS power plants needed to be put online in addition to carbon capture processes on coal-fired power plants. The volatility of natural gas prices was found to have a significant impact on the optimal CO2 mitigation strategy and on the cost of electricity generation. Increasing the natural gas prices resulted in early aggressive CO2 mitigation strategies especially at higher growth rate demands. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

ALGAL-RELATED TASTES AND ODORS IN PHOENIX WATER SUPPLY: PRELIMINARY REPORT

JOURNAL OF PHYCOLOGY, Issue 2000
Q. Hu
Frequent episodes of algal-related tastes and odors (T & O) in drinking waters in metropolitan Phoenix, Arizona prompted initiation of a three-year project in July 1999 to investigate the occurrence of T & O metabolites and to develop a comprehensive management strategy to reduce the problems in drinking water supplies in arid environments. Two metabolites, 2-methylisoborneol (MIB) and geosmin, have been identified as compounds responsible for the earthy-musty tastes and odors in water supplies. Both were detected in the water supply system, including source rivers, reservoirs, canal delivery system and water treatment plants. Higher concentrations of MIB and geosmin occurred in distribution canals than in the upstream reservoirs indicating that significant production of the T & O compounds occurs within the canal system. A baseline-monitoring program has been established for the complex water supply system, with special emphasis on the canal system. Efforts are underway to investigate possible correlations between physical/chemical parameters, algal composition and biomass, with the occurrence of MIB and geosmin. In addition, several physical and chemical treatments are planned for the canal system to reduce algal growth and related MIB and geosmin concentrations. [source]

Structural Features of the NAD-Dependent In Situ Retinoic Acid Supply System in Esophageal Mucosa

Analysis of optimal controls for a mathematical model of tumour anti-angiogenesis

OPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 1 2008
U. Ledzewicz
Abstract Anti-angiogenic therapy is a novel treatment approach for cancer that aims at preventing a tumour from developing its own blood supply system that it needs for growth. In this paper we consider a mathematical model where the endogenous stimulation term in the dynamics is taken proportional to the number of endothelial cells. This system is an example from a class of mathematical models for anti-angiogenic treatment that were derived from a biologically validated model by Hahnfeldt, Panigrahy, Folkman and Hlatky. The problem how to schedule a given amount of angiogenic inhibitors to achieve a maximum reduction in the primary cancer volume is considered as an optimal control problem and it is shown that optimal controls are bang-bang of the type 0a0 with 0 denoting a trajectory corresponding to no treatment and a a trajectory with treatment at maximum dose along that all inhibitors are being exhausted. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Warning procedures for systems that are improving

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 4 2008
Luis A. García-Escudero
Abstract Nowadays it is quite usual that systems are correctly maintained. This leads to a decreasing number of failures for the system. In this paper we discuss how to establish warning procedures that take into account features giving the chance of detecting eventual changes of trend in the systems and allowing taking measures before too much damage has actually happened. The proposed procedure is applied to the study of the reliability and maintenance of the railway electric supply system. In this kind of systems, complex and extended, testing the performance of the system and effectiveness of the maintenance tasks has special interest. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A Case Study of the Beneficial Reuse of Treated Groundwater

REMEDIATION, Issue 3 2001
Andrew Curtis Elmore
The future disposal of treated groundwater at the former Nebraska Ordnance Plant (NOP) Superfund site has been a topic of interest to the local property owners, the U.S. Army Corps of Engineers, and the local regulatory agencies. The Record of Decision for the site includes the extraction, treatment, and disposal of almost 3,000 gpm of groundwater with an estimated restoration time period exceeding 100 years. Interest from property owners and the Nebraska agency charged with regulating groundwater supply prompted the Corps of Engineers to consider several strategies for beneficially reusing the treated water. Alternatives included the establishment of a rural water district or local distribution system; delivery of the water to the municipal supply system of Lincoln, Nebraska, andsol;or other nearby municipalities; and consideration of innovative remedial technologies to reduce the quantity of treated water requiring disposal. The selected disposal plan consists of providing treated groundwater to interested parties for agricultural use with excess treated groundwater discharged to two streams. Multiple feasibility studies were generated, public input was solicited, and interagency agreements were executed during the course of the project. The remediation project is currently being constructed, and at least one property owner has constructed a new center-pivot irrigation system to use the treated groundwater. © 2001 John Wiley & Sons. [source]

LEAD ISOTOPIC EVIDENCE FOR A MIXED PROVENANCE FOR ROMAN WATER PIPES FROM POMPEII,

ARCHAEOMETRY, Issue 1 2000
M. BONI
Lead isotope analysis has been applied to the investigation of some Roman objects found in the town of Pompeii, consisting mostly of fistulae from the Augustan water supply system. The results of the analyses have produced ratios between 18.10 and 18.66 for 206Pb/204Pb, between 15.63 and 15.72 for 207Pb/204Pb and between 38.21 and 38.98 for 208Pb/204Pb. These data point to a fairly complex origin for the lead artefacts, probably involving several successive meltings and recyclings of a rather heterogeneous lead supply. The spread of lead isotope ratios can only be reconciled with a multiplicity of end-members, at least three, but very probably more. There is one certain Sardinian ore, other indistinguishable Hercynian ores of Sardinia and/or Spain, and several different Alpine Mesozoic-Tertiary mineralizations of the Mediterranean basin (Spain, Greece, Tuscany). [source]

Geography of Production Linkages in the Irish and Scottish Microcomputer Industry: The Role of Logistics

ECONOMIC GEOGRAPHY, Issue 3 2005
Chris van Egeraat
Abstract: The economic crisis of the mid-1970s marked the transition from the traditional Fordist mode of industrial organization to one of time-based competition (TBC). It has been postulated that the rise of TBC will lead to an increase in local and regional production linkages. Part of the argument is that the associated search for logistical efficiency and the adoption of the just-in-time (JIT) principles will lead to closer buyer-supplier proximity. In this article, we test the relevance of this idea in a case study of the microcomputer hardware industry in Ireland and Scotland. Most of the data were collected during multiple interviews with subsidiaries of all global microcomputer assemblers with operations in one of the two countries. The study shows that rather than sourcing locally or regionally, the assemblers import the vast majority of their material inputs from regions outside Ireland and Britain, notably from the Far East, and that the inbound logistics pipelines of most components involve inventories, often hubbed in local warehouses. Such supply systems have been interpreted as pseudo-JIT, suboptimal inbound logistics systems that are organized on traditional Fordist principles. We argue that the logistics systems and the geography of the supply linkages should not be interpreted this way. Inbound inventories were tightly managed, leading to modest target buffer levels and high shipment frequencies. Even under JIT supply, the geographic configuration of production linkages and the details of logistics systems remain highly dependent on a range of contextual conditions and component characteristics. The findings of this study suggest that a strategy of building integrated vertical production clusters around subsidiaries of multinational enterprises is no longer suitable for Ireland and Scotland, at least not in the context of the microcomputer industry. [source]

Reliability modelling of uninterruptible power supply systems using fault tree analysis method

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2009
Mohd Khairil Rahmat
Abstract The aim of this paper is to investigate the reliability parameters estimation method for the uninterruptible power supply (UPS) systems using the Fault Tree Analysis (FTA) technique. FTA is a top,down approach to identify all potential causes leading to system failure. The computation of the system's failure probability is the main goal of this analysis, as this value can be used to calculate other important system reliability parameters such as failure rates, mean time between failures and reliability. In this paper, the FTA method was applied to five different UPS topologies and the results obtained were compared and discussed in detail. By comparing the critical fault path of the system, it was found that the inverter failures contributed most significantly to the system failure. It was also found that the probability of failure of a UPS system can be reduced by the inclusion of bypass supply, given that the failure rate of the events that causing the failure of the bypass supply should be lower compared to the ones for the main utility supply. Finally, to validate the results obtained from this method, comparisons were made to the results from other methods such as the Reliability Block Diagram, Boolean Truth Table, Probability Tree, Monte-Carlo Simulation and Field Data reliability estimation methods. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Financial costs and environmental impact optimization of the energy supply systems

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2002
L. I. González-Monroy
Abstract We have designed and implemented a tool to evaluate and optimize energy supply systems, so that the financial costs, the consumption of primary energy or the amount of harmful emission to the environment are minimized. We have set-up a general description of these systems and have applied a heuristic optimization method, Simulated Annealing, that allows us, in an efficient way, to determine the best way to fulfil different types of energy demand using a set of facilities of energy transformation and storage. We have also considered the time correlation introduced by the storage devices or transport processes and the possible behaviour of the system when the external conditions (fuel prices, demand profiles, etc.) change. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Strategies to reduce medication errors with reference to older adults

INTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 1 2006
Brent Hodgkinson BSc (Hons) MSc GradCertPH GradCertEcon(Health)
Abstract Background, In Australia, around 59% of the general population uses prescription medication with this number increasing to about 86% in those aged 65 and over and 83% of the population over 85 using two or more medications simultaneously. A recent report suggests that between 2% and 3% of all hospital admissions in Australia may be medication related with older Australians at higher risk because of higher levels of medicine intake and increased likelihood of being admitted to hospital. The most common medication errors encountered in hospitals in Australia are prescription/medication ordering errors, dispensing, administration and medication recording errors. Contributing factors to these errors have largely not been reported in the hospital environment. In the community, inappropriate drugs, prescribing errors, administration errors, and inappropriate dose errors are most common. Objectives, To present the best available evidence for strategies to prevent or reduce the incidence of medication errors associated with the prescribing, dispensing and administration of medicines in the older persons in the acute, subacute and residential care settings, with specific attention to persons aged 65 years and over. Search strategy, Bibliographic databases PubMed, Embase, Current contents, The Cochrane Library and others were searched from 1986 to present along with existing health technology websites. The reference lists of included studies and reviews were searched for any additional literature. Selection criteria, Systematic reviews, randomised controlled trials and other research methods such as non-randomised controlled trials, longitudinal studies, cohort or case,control studies, or descriptive studies that evaluate strategies to identify and manage medication incidents. Those people who are involved in the prescribing, dispensing or administering of medication to the older persons (aged 65 years and older) in the acute, subacute or residential care settings were included. Where these studies were limited, evidence available on the general patient population was used. Data collection and analysis, Study design and quality were tabulated and relative risks, odds ratios, mean differences and associated 95% confidence intervals were calculated from individual comparative studies containing count data where possible. All other data were presented in a narrative summary. Results, Strategies that have some evidence for reducing medication incidents are: ,,computerised physician ordering entry systems combined with clinical decision support systems; ,,individual medication supply systems when compared with other dispensing systems such as ward stock approaches; ,,use of clinical pharmacists in the inpatient setting; ,,checking of medication orders by two nurses before dispensing medication; ,,a Medication Administration Review and Safety committee; and ,,providing bedside glucose monitors and educating nurses on importance of timely insulin administration. In general, the evidence for the effectiveness of intervention strategies to reduce the incidence of medication errors is weak and high-quality controlled trials are needed in all areas of medication prescription and delivery. [source]

Performance assessment under field conditions of a rapid immunological test for transgenic soybeans

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2001
John Fagan
Summary Current market conditions and food regulations make it necessary for international and domestic participants in the agrifood industry to structure supply chains that control the content of genetically modified (GM) material in their products. Tests to detect and/or quantify GM components represent an important tool in maintaining such supply systems. This study assesses the field performance of kits that employ lateral flow immuno-technology to detect soybeans GM to be resistant to the herbicide glyphosate. Operators at 23 grain-handling facilities were paid to conduct analyses on a series of blinded samples containing defined proportions of conventional and transgenic soybeans. The observed rate of false positives was 6.7% in an experiment in which the highest level of GM material was 1% and 22.3% in a second experiment in which the highest level of GM material was 10%. This difference may be attributed to increased risk of cross-contamination with the higher level of transgenic material used in the second study. Samples containing 0.01% GM material were reported as genetically modified 6.70% of the time, while samples containing 0.1, 0.5 and 1% GM material were classified as genetically modified 29.5, 67.7 and 68.2% of the time, respectively. Thus, the frequencies of false negatives were 93.3, 70.5, 33.3 and 31.8% for samples containing 0.01, 0.1, 0.5 and 1.0% GM material. Samples containing 10% GM material were correctly reported as genetically modified in all cases. These results lead to the conclusion that the kit under study is useful in screening for lots of soybeans that contain high levels of GM material, but that, as a field tool, it is not effective in monitoring for GM material at the level of 1.0% or lower. Statistical and immunochemical analyses were carried out in order to assess the relative contributions of various factors to the error observed in these studies. These analyses indicated that limitations in operator performance, not defects in test kit materials, were the primary contributors, while sample size may play a secondary role. As both operator performance and sample size are independent of the specific characteristics of the test kit used in this study, it appears justifiable to generalize conclusions obtained here to other similar test systems. [source]

The Trickle-down Effect: Ideology and the Development of Premium Water Networks in China's Cities

INTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 1 2007
ALANA BOLAND
This article examines the relationship between networked infrastructure and uneven development in transitional cities through a study of premium water networks in China. Beginning in the mid-1990s, select buildings and housing enclaves began to bypass municipal tap water supply systems through the construction of small-scale secondary pipe networks for purified drinking water. I focus on the early development of these premium water networks to highlight the ideological interplay between a new more market-based approach to networked supply and the existing model characterized by relatively universal and uniform access within cities. I illustrate how this dual water supply model was well suited to the ideological conditions and contradictions associated with China's economic liberalization in the 1990s. While the emergence of premium water networks can be linked to ascendant forms of market reasoning in the environmental and social spheres, I also argue that they were enabled by unresolved ideological tensions associated with China's transitional program. Rather than providing a basis for resistance in the early development of premium water supply, the socialist legacy in urban water supply left its mark more in the noticeable absence of debate regarding the distributional outcomes. By examining premium water networks in relation to the politics of ideology in China's transitional period, my analysis highlights the complex and sometimes unexpected ways that ideologies can influence the development of new infrastructural spaces and processes of splintering urbanism. [source]