WorldWideScience

Sample records for assessing lead time

  1. Assessment of realistic nowcasting lead-times based on predictability analysis of Mediterranean Heavy Precipitation Events

    Science.gov (United States)

    Bech, Joan; Berenguer, Marc

    2014-05-01

    Operational quantitative precipitation forecasts (QPF) are provided routinely by weather services or hydrological authorities, particularly those responsible for densely populated regions of small catchments, such as those typically found in Mediterranean areas prone to flash-floods. Specific rainfall values are used as thresholds for issuing warning levels considering different time frameworks (mid-range, short-range, 24h, 1h, etc.), for example 100 mm in 24h or 60 mm in 1h. There is a clear need to determine how feasible is a specific rainfall value for a given lead-time, in particular for very short range forecasts or nowcasts typically obtained from weather radar observations (Pierce et al 2012). In this study we assess which specific nowcast lead-times can be provided for a number of heavy precipitation events (HPE) that affected Catalonia (NE Spain). The nowcasting system we employed generates QPFs through the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011).Then QPFs up to 3h are compared with two quality controlled observational data sets: weather radar quantitative precipitation estimates (QPE) and raingauge data. Several high-impact weather HPE were selected including the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) both producing, among other effects, local flash floods. In these two events there were torrential rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and 24h accumulation values above 100 mm. A number of verification scores are used to characterize the evolution of precipitation forecast quality with time, which typically presents a decreasing trend but showing an strong dependence on the selected rainfall threshold and integration period. For example considering correlation factors, 30

  2. Leading time domain seismic precursors

    Science.gov (United States)

    Boucouvalas, A. C.; Gkasios, M.; Keskebes, A.; Tselikas, N. T.

    2014-08-01

    The problem of predicting the occurrence of earthquakes is threefold. On one hand it is necessary to predict the date and magnitude of an earthquake, and on the other hand the location of the epicenter. In this work after a brief review of the state of earthquake prediction research, we report on a new leading time precursor for determining time onset of earthquake occurrence. We report the linking between earthquakes of the past with those which happen in the future via Fibonacci, Dual and Lucas numbers (FDL) numbers. We demonstrate it here with two example seed earthquakes at least 100 years old. Using this leading indicator method we can predict significant earthquake events >6.5R, with good accuracy approximately +- 1 day somewhere in the world. From a single seed we produce at least 100 trials simultaneously of which 50% are correct to +- 1day. The indicator is based on Fibonacci, Dual and Lucas numbers (FDL). This result hints that the log periodic FDL numbers are at the root of the understanding of the earthquake mechanism. The theory is based on the assumption that each occurred earthquake discontinuity can be thought of as a generating source of FDL time series. (The mechanism could well be linked to planetary orbits). When future dates are derived from clustering and convergence from previous strong earthquake dates at an FDL time distance, then we have a high probability for an earthquake to occur on that date. We set up a real time system which generates FDL time series from each previous significant earthquake (>7R) and we produce a year to year calendar of high probability earthquake dates. We have tested this over a number of years with considerable success. We have applied this technique for strong (>7R) earthquakes across the globe as well as on a restricted region such as the Greek geographic region where the magnitude is small (>4R-6.5R). In both cases the success of the method is impressive. It is our belief that supplementing this method with

  3. Leading in Times of Crisis

    OpenAIRE

    Jungbauer, Kevin-Lim

    2016-01-01

    Crisis represents an important contextual variable in the leader-follower relationship. Never is it as important as in times of “shock” when followers experience intense uncertainty and seek for sources of protection and guidance, that leaders are required to step in and find appropriate ways to alleviate fears, restore a sense normalcy, and maintain effective functioning. Over the years, studies from multiple disciplines have accumulated to a large body of literature on the topic of crisis l...

  4. Assessment of lead in cosmetic products.

    Science.gov (United States)

    Al-Saleh, Iman; Al-Enazi, Sami; Shinwari, Neptune

    2009-07-01

    There have been a number of recent reports in the media and on the internet about the presence of lead in brand-names lipsticks. This has drawn our attention to assess the safety of various cheap brands of cosmetics sold at 2-riyals stores in Saudi market that are imported from countries where safety regulations are poorly enforced as well as they lack perfect conditions for manufacturing. Lead contents were determined in 26 and eight different brands of lipsticks and eye shadows using the Zeeman atomic absorption spectrophotometer coupled to graphite tube atomizer after an acid digestion procedure. Lead was detected in all the studied samples. The median (25th-75th percentile) lead content in 72 lipsticks samples was 0.73 (0.49-1.793) PPM wet wt. in the range of 0.27-3760 PPM wet wt. There were four brands of lipsticks with lead content above the FDA lead limit as impurities in color additives (20 PPM). The FDA does not set a limit for lead in lipstick. Three of them were extremely high points and considered outliers. The median (25th-75th percentile) lead contents in pressed powder eye shadow was 1.38 (0.944-1.854) PPM wet wt. (n=22) in the range of 0.42-58.7 PPM wet wt. One brand was above 20 PPM the US FDA's lead limit as impurities. The overall results indicate that lead in lipsticks and eye shadows are below the FDA lead limit as impurities and, thus, probably have no significant toxicological effects. Nevertheless, few brands had lead content above 20 PPM that might put consumers at the risk of lead poisoning. Lead is a cumulative, and applying lead-containing cosmetics several times a day or every day, can potentially add up to significant exposure levels. Pregnant and nursing mothers are vulnerable population because lead passes through placenta and human milk and affect fetus or infant's developments. Our findings call for an immediate mandatory regular testing program to check lead and other toxic metals in lipsticks and other cosmetic products imported

  5. Optimal lead time for dengue forecast.

    Directory of Open Access Journals (Sweden)

    Yien Ling Hii

    Full Text Available BACKGROUND: A dengue early warning system aims to prevent a dengue outbreak by providing an accurate prediction of a rise in dengue cases and sufficient time to allow timely decisions and preventive measures to be taken by local authorities. This study seeks to identify the optimal lead time for warning of dengue cases in Singapore given the duration required by a local authority to curb an outbreak. METHODOLOGY AND FINDINGS: We developed a Poisson regression model to analyze relative risks of dengue cases as functions of weekly mean temperature and cumulative rainfall with lag times of 1-5 months using spline functions. We examined the duration of vector control and cluster management in dengue clusters > = 10 cases from 2000 to 2010 and used the information as an indicative window of the time required to mitigate an outbreak. Finally, we assessed the gap between forecast and successful control to determine the optimal timing for issuing an early warning in the study area. Our findings show that increasing weekly mean temperature and cumulative rainfall precede risks of increasing dengue cases by 4-20 and 8-20 weeks, respectively. These lag times provided a forecast window of 1-5 months based on the observed weather data. Based on previous vector control operations, the time needed to curb dengue outbreaks ranged from 1-3 months with a median duration of 2 months. Thus, a dengue early warning forecast given 3 months ahead of the onset of a probable epidemic would give local authorities sufficient time to mitigate an outbreak. CONCLUSIONS: Optimal timing of a dengue forecast increases the functional value of an early warning system and enhances cost-effectiveness of vector control operations in response to forecasted risks. We emphasize the importance of considering the forecast-mitigation gaps in respective study areas when developing a dengue forecasting model.

  6. Production Planning with Load Dependent Lead Times

    DEFF Research Database (Denmark)

    Pahl, Julia

    2005-01-01

    Lead times impact the performance of the supply chain significantly. Although there is a large literature concerning queuing models for the analysis of the relationship between capacity utilization and lead times, and there is a substantial literature concerning control and order release policies...

  7. Emerging aspects of assessing lead poisoning in childhood

    Directory of Open Access Journals (Sweden)

    AL Jones

    2009-01-01

    Full Text Available This review covers the epidemiology of lead poisoning in children on a global scale. Newer sources of lead poisoning are identified. The methods that are used to assess a population of children exposed to lead are discussed, together with the ways of undertaking an exposure risk assessment; this includes assessing the time course and identifying sources of lead exposure. Human assessment measures for lead toxicity, such as blood lead concentrations, deciduous tooth lead, and use of zinc protoporphyrin estimations are evaluated. The role of isotopic fingerprinting techniques for identifying environmental sources of exposure is discussed. Among emerging data on the cognitive and behavioral effects of lead on children, the review considers the growing evidence of neurocognitive dysfunction with blood lead concentrations even below 10 |[mu]|g/dl. The challenge of assessing and explaining the risk that applies to an individual as opposed to a population is discussed. Intervention strategies to mitigate risk from lead are examined together with the limited role for and limitations of chelation therapy for lead. Lessons learned from managing a population lead-dust exposure event in Esperance, Western Australia in 2007 are discussed throughout the review.

  8. 2013 Final Report: Integrated Science Assessment for Lead

    Science.gov (United States)

    lead_isa_cover.jpg" alt="Cover of the Integrated Science Assessment (ISA) for Lead" vspace = "5" hspace="5" align="right" border="1" /> EPA released the final report, Integrated Science Assessment (ISA) for Lead (...

  9. Capacity Expansion for Random Exponential Demand Growth with Lead Times

    OpenAIRE

    Ryan, Sarah M.

    2004-01-01

    The combination of demand uncertainty and a lead time for adding capacity creates the risk of capacity shortage during the lead time. We formulate a model of capacity expansion for uncertain exponential demand growth and deterministic expansion lead times when there is an obligation to provide a specified level of service. The service level, defined in terms of the ratio of expected lead-time shortage to installed capacity, is guaranteed by timing each expansion to begin when demand reaches a...

  10. Editorial: Lead Risk Assessment and Health Effects

    Science.gov (United States)

    Mielke, Howard W.

    2016-01-01

    In 1980, Clair C. Patterson stated: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century”. We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson’s statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention. PMID:27314364

  11. Editorial: Lead Risk Assessment and Health Effects

    Directory of Open Access Journals (Sweden)

    Howard W. Mielke

    2016-06-01

    Full Text Available In 1980, Clair C. Patterson stated: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century”. We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson’s statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention.

  12. Assessment and Remediation of Lead Contamination in Esperance, Western Australia

    Directory of Open Access Journals (Sweden)

    McCafferty P. B.

    2013-04-01

    Full Text Available This paper presents an overview of a lead contamination event that occurred over a period of time in and around Esperance, Western Australia. It also describes the scientific developments necessary to effect the large scale cleanup of lead contamination in the town. This work was possibly the largest environmental cleanup of its kind ever undertaken in Australia. The work undertaken involved characterisation and assessment of the extent of contamination, development of remediation techniques and validation procedures to ensure that that this cleaning had been successful.

  13. Mixture distributions for modelling demand during lead time

    OpenAIRE

    B R Cobb

    2013-01-01

    A mixture distribution approach to modelling demand during lead time in a continuous-review inventory model is described. Using this approach, both lead time and demand per unit time can follow state-dependent distributions. By using mixtures of truncated exponentials functions to approximate these distributions, mixture distributions that can be easily manipulated in closed form can be constructed as the marginal distributions for lead time and demand per unit time. These are then used to ap...

  14. Parameterization of MRP for Supply Planning Under Lead Time Uncertainties

    OpenAIRE

    A Dolgui; Hnaien, F.; Louly, A.; Marian, H.

    2008-01-01

    We studied an MRP parameterization problem for assembly systems under component lead time uncertainties. This problem of inventory control and production planning under uncertainties is crucial for industry. Most publications are devoted to customer demand uncertainties. In contrast, lead time uncertainties seem not be sufficiently studied, in particular, for the control of component inventories for assembly systems with random component procurement times (lead times). Nevertheless, many of i...

  15. 75 FR 8934 - Integrated Science Assessment for Lead (Pb)

    Science.gov (United States)

    2010-02-26

    ... AGENCY Integrated Science Assessment for Lead (Pb) AGENCY: Environmental Protection Agency. ACTION... (NAAQS) for Lead (Pb). This ISA is intended to update and revise, where appropriate, the scientific assessment presented in the Air Quality Criteria for Lead (EPA/600/R-5/144aF), published on October 1,...

  16. Dual sourcing : with arbitrary stochastic demand and stochastic lead times

    OpenAIRE

    Schimpel, Ulrich

    2010-01-01

    Companies with high-performing supply chains enjoy essential competitive ad- vantages. However, supply chain management faces an environment of rising risk that endangers these competitive advantages. One of the reasons is to outsource parts of their business. This bears the risk of significantly increased lead times and lead time variability. It is the impact of lead time variability on inventory management that is the central aspect of this book. It describes a mathematical model for dual s...

  17. The impact of stochastic lead times on the bullwhip effect

    OpenAIRE

    Michna, Zbigniew; Nielsen, Peter; Nielsen, Izabela Ewa

    2014-01-01

    In this article we want to review the research state on the bullwhip effect in supply chains with stochastic lead times and give a contribution to quantifying the bullwhip effect. We analyze the models quantifying the bullwhip effect in supply chains with stochastic lead times and find advantages and disadvantages of their approaches to the bullwhip problem. Using real data we confirm that real lead times are stochastic and can be modeled by a sequence of independent identically distributed r...

  18. Pulmonary and gastric lead burden assessment for lead-recycling plant workers

    OpenAIRE

    Uzu, Gaëlle; Sauvain, Jean-Jacques; Baeza, Armelle; Riediker, Michael; Sanchez Sandoval Hohl, Magdalena; Val, Stéphanie; Tack, Karine; Denys, Sébastien; Pradere, Philippe; Dumat, Camille

    2011-01-01

    As a function of PM size (PM10-2.5, PM2.5-1 and PM1) and origin (furnace, refining and channeled emissions), lead toxicity and bioaccessibility assessment were performed in a lead recycling plant using complementary biologic and chemical acellular tests. According to their origin, process PM displays differences in metal contents, granulometry and percentage of inhalable fraction. Lead gastric bioaccessibility was relatively low (maximum 25%) in comparison with previous available studies, tho...

  19. Resonance and decay phenomena lead to quantum mechanical time asymmetry

    International Nuclear Information System (INIS)

    The states (Schrödinger picture) and observables (Heisenberg picture) in the standard quantum theory evolve symmetrically in time, given by the unitary group with time extending over −∞ 0 ≤ t 0, where t0 is the ensemble of time at which each individual system has been prepared. The Hardy space axiom also leads to the new prediction: the width Γ and the lifetime τ are exactly related by τ = h/Γ.

  20. 76 FR 38650 - Draft Integrated Science Assessment for Lead

    Science.gov (United States)

    2011-07-01

    ... announcing the public comment period was published on May 6, 2011 (76 FR 26284). This assessment document was... instructions provided in the SUPPLEMENTARY INFORMATION section of Federal Register Notice (76 FR 26284). For... AGENCY Draft Integrated Science Assessment for Lead AGENCY: Environmental Protection Agency....

  1. Leaded Paint in Cambodia—Pilot-scale Assessment

    Directory of Open Access Journals (Sweden)

    Sereyrath Lim

    2015-01-01

    Conclusion. Based on our pilot-scale assessment, high levels of lead appear to be common in enamel paints in Cambodia, and a fuller assessment of the situation is warranted. Import and production of such toxic products should be avoided and appropriate labeling and public warnings should be provided.

  2. The impact of project management on nuclear construction lead times

    International Nuclear Information System (INIS)

    A two-year study of lead times for nuclear power plants found that construction time is affected by six fundamental influences. One of the six is project management. An analysis of construction management teams at 26 nuclear units found that many of the most successful shared five general characteristics: nuclear power experience, skill in project control, adaptability and initiative, commitment to success, and communication and coordination skill

  3. Evaluating Lead Time Decisions : A Case Study within the General Automotive Industry

    OpenAIRE

    Heiberg, Bjørn Erik Grov; Moltu, Jørgen Thomren; Fredriksen, Martin Petter

    2014-01-01

    Managers often experience problems with quantifying the value of reducing or extending lead time when assessing different sourcing alternatives. In practice, these decisions are often made considering only unit procurement cost, transportation cost, capital cost and storage cost. However, the lead time of suppliers highly influences a business' exposure to demand uncertainty. This can yield large monetary values that should be accounted for. This Master's Thesis presents a case stud...

  4. Ultrafast time-resolved spectroscopy of lead halide perovskite films

    Science.gov (United States)

    Idowu, Mopelola A.; Yau, Sung H.; Varnavski, Oleg; Goodson, Theodore

    2015-09-01

    Recently, lead halide perovskites which are organic-inorganic hybrid structures, have been discovered to be highly efficient as light absorbers. Herein, we show the investigation of the excited state dynamics and emission properties of non-stoichiometric precursor formed lead halide perovskites grown by interdiffusion method using steady-state and time-resolved spectroscopic measurements. The influence of the different ratios of the non-stoichiometric precursor solution was examined. The observed photoluminescence properties were correlated with the femtosecond transient absorption measurements.

  5. Determination of lead and radioactivity in cosmetics products: Hazard assessment

    OpenAIRE

    Medhat Moustafa E.; Singh Vishwanath P.; Shirmardi Seyed P.

    2015-01-01

    In the proposed work, an investigation on hazard assessment by lead element and natural radioactivity in cosmetic samples collected from various countries is presented. These samples were face powder, eyebrow paint and henna. The lead element in cosmetic samples was determined using particle-induced X-ray emission. Maximum natural radioactivity concentrations of 226Ra and 40K were found in khol and make-up cosmetic samples, respectively. The qualitative ana...

  6. Assessment of soil lead exposure in children in Shenyang, China

    International Nuclear Information System (INIS)

    Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mg kg-1). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure. - Children were exposed to soil lead and the exposure was assessed by bioaccessibility using in vitro digestion model in a modified version

  7. Time evolution of laser-induced breakdown spectrometry of lead

    International Nuclear Information System (INIS)

    The plasma have been generated by a pulsed Nd: YAG laser at the fundamental wavelength of 1.06 μm ablating a metal lead target in air at atmospheric pressure, and the time resolved emission spectra were gotten. Time evolution of electron temperatures were measured according to the wavelength and relative intensity of spectra; then the electron densities were obtained from the Stark broadening of Pb-line; the time evolution of electron temperatures and electron densities along the direction plumbing the target surface were imaged. The analysis of results showed that electron temperature averaged to 14500 K, electron densities up to 1017 cm-3. The characteristics of time evolution of electron temperature and electron density were qualitatively explained from the aspect of generation mechanism of laser-induced plasmas. (authors)

  8. Investigation on life cycle assessment of lead and zinc production

    Directory of Open Access Journals (Sweden)

    Sabere Nazari

    2015-12-01

    Full Text Available Lead and zinc production is one of the main predisposing factors of excessive greenhouse gases emissions, air pollution and water consumption. In this paper, the environmental problems of lead and zinc production in Calcimin plant are expressed and life cycle assessment of this plant is assessed. The data regarding the amount of induced global warming and pollution, acidification, and depletion of water resources were collected and discussed. It was concluded that depletion of water resources affected the environment and this was the main issue of the lead and zinc production of this plant. According to the results, in the global warming’s impact category, the proportion of carbon dioxide is more than that of methane. The results also showed that in the acidification’s impact category, the nitrogen oxide proportion is greater compared to that of the sulfur dioxide.

  9. LEADING CHANGES IN ASSESSMENT USING AN EVIDENCE BASED APPROACH

    Directory of Open Access Journals (Sweden)

    J. O. Macaulay

    2015-08-01

    Full Text Available Introduction and objectivesIt is has been widely accepted that assessment of learning is a critical component of education and that assessment drives/guides student learning through shaping study habits and student approaches to learning. However, although most academics would agree that assessment is a critical aspect of their roles as teachers it is often an aspect of teaching that is regarded more as an additional task rather than an integral component of the teaching/learning continuum. An additional impediment to high quality assessment is the non-evidence based-approach to the decision making process. The overall aim of this project was to improve the quality of assessment in Biochemistry and Molecular Biology undergraduate education by promoting high quality assessment.Materials and methodsTo do this we developed and trialled an audit tool for mapping assessment practices. The audit tool was designed to gather data on current assessment practices and identify areas of good practice in which assessment aligned with the learning objectives and areas in need of improvement. This evidence base will then be used to drive change in assessment.Results and conclusionsUsing the assessment mapping tool we have mapped the assessment regime in a Biochemistry and Molecular Biology major at Monash University. Criteria used included: assessment type, format, timing, assessors, provision of feedback, level of learning (Bloom’s, approaches taken to planning assessment. We have mapped assessment of content and the systematic development of higher order learning and skills progression throughout the program of study. The data has enabled us to examine the assessment at unit (course level as well as the vertical development across the major. This information is now being used to inform a review of the units and the major.

  10. Influence of product return lead-time on inventory control

    OpenAIRE

    Zerhouni, Mohamed Hichem; Gayon, Jean-Philippe; Frein, Yannick

    2009-01-01

    We consider a production-inventory system with capacity constraint and item returns correlated to demand. The system is modelled by an M/M/1 make-to-stock queue with lost sales. A satisfied demand incurs an item return with a certain probability, after an exponentially distributed return lead-time. We distinguish two cases: When the number of items to be returned is observable and when it is not observable. For the first case, we partially characterize the optimal policy. For the second case, w...

  11. Textural Perceptions of School Time and Assessment

    Science.gov (United States)

    Turley, Eric D.

    2006-01-01

    In this article, the author explores how two schools in Nebraska perceive time as they teach and assess student learning. Parker Middle School views time as fixed and sees its teaching and assessing as in perpetual conflict because there is not enough time to do both. Arbor School views time in a more fluid way, allowing teaching and assessment to…

  12. Lead-Time Models Should Not Be Used to Estimate Overdiagnosis in Cancer Screening

    DEFF Research Database (Denmark)

    Zahl, Per-Henrik; Jørgensen, Karsten Juhl; Gøtzsche, Peter C

    2014-01-01

    Lead-time can mean two different things: Clinical lead-time is the lead-time for clinically relevant tumors; that is, those that are not overdiagnosed. Model-based lead-time is a theoretical construct where the time when the tumor would have caused symptoms is not limited by the person's death. It...

  13. Time management situation assessment (TMSA)

    Science.gov (United States)

    Richardson, Michael B.; Ricci, Mark J.

    1992-01-01

    TMSA is a concept prototype developed to support NASA Test Directors (NTDs) in schedule execution monitoring during the later stages of a Shuttle countdown. The program detects qualitative and quantitative constraint violations in near real-time. The next version will support incremental rescheduling and reason over a substantially larger number of scheduled events.

  14. Four decades of gasoline lead emissions and control policies in Europe. A retrospective assessment

    Energy Technology Data Exchange (ETDEWEB)

    Von Storch, Hans; Costa-Cabral, Mariza; Hagner, Charlotte; Feser, Frauke [Institute for Coastal Research, GKSS Research Centre, 21502 Geesthacht (Germany); Pacyna, Jozef; Pacyna, Elisabeth [Norwegian Institute for Air Research (NILU) (Norway); Kolb, Steffen [Institute for Journalism and Communication Research, University of Hamburg, Hamburg (Germany)

    2003-07-20

    Over decades, large amounts of the neurotoxin lead were released into the European environment, mostly from gasoline lead additives. Emissions were growing unabatedly until the 1970s, when a series of regulations on the allowed gasoline lead content were adopted. As a result, in the 1990s most gasoline contained only small amounts of lead. We have examined this case of environmental pollution and regulation, and performed a retrospective assessment of the extent of regional-scale lead pollution and the effects of gasoline lead regulations in Europe. With the help of a regional climate model, NCEP re-analyses, spatially disaggregated lead emissions from road traffic and point sources, and various local data, the airborne pathways and depositions of gasoline lead in Europe since 1958 were reconstructed. It turns out that this approach is successful in describing the time-variable, spatially disaggregated deposition of gasoline lead. Additional data from analyses of concentrations in biota, including plant leaves, mussels and human blood, allows an assessment about the impact of the lead phase-out on the quality of the environment. Demonstrating the success of the lead policies, concentrations in leaves and human blood have steadily declined since the early 1980s. At the same time, the economic repercussions that had been feared did not emerge. Instead, the affected mineral oil and car manufacturing industries in Germany (our case-study) were able to deal with the effort without incurring significant extra costs. We suggest that our method of quantitatively reconstructing and anticipating fluxes and depositions of substances can be applied to other relevant substances as well, such as, for example, Persistent Organic Pollutants, radioactive substances or pollens.

  15. Lead

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This is one of a series of reports made on industrial pollutants by the Expert Panel on Air Quality Standards to advise the United Kingdom Government on air quality standards. It describes the main sources of lead exposure, including the relative contribution of lead in the air and lead in the diet, and the methods by which it is measured in air. The Panel also considers the airborne concentrations recorded to date in the United Kingdom, ways in which lead is handled in by the body, and its toxic effects on people. The dominant source of airborne lead is petrol combustion. Other source include coal combustion, the production of non-ferrous metals and waste treatment and disposal. The justification of an air quality standard for lead is set down. The Panel recommends an air quality standard for lead in the United Kingdom of 0.25 {mu}g/m{sup 3} measured as an annual average. This is intended to protect young children, the group most vulnerable to impairment of brain function. 17 refs., 3 figs., 2 tabs.

  16. Real time tests for long lead-time forecasting of the magnetic field vectors within CMEs

    Science.gov (United States)

    Savani, Neel; Vourlidas, Angelos; Pulkkinen, Antti; Wold, Alexandra M.

    2016-07-01

    The direction of magnetic vectors within coronal mass ejections, CMEs, has significant importance for forecasting terrestrial behavior. We have developed a technique to estimate the time-varying magnetic field at Earth for periods within CMEs (Savani et al 2015, 2016). This technique reduces the complex dynamics in order to create a reliable prediction methodology to operate everyday under robust conditions. In this presentation, we focus on the results and skill scores of the forecasting technique calculated from 40 historical CME events from the pre-STEREO mission. Since these results provided substantial improvements in the long lead-time Kp index forecasts, we have now begun testing under real-time conditions. We will also show the preliminary results of our methodology under these real-time conditions within the CCMC hosted at NASA Goddard Space Flight Center.

  17. Health assessment for Interstate Lead Company, Leads, Alabama, Region 4. CERCLIS No. ALD041906173. Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-10

    The Interstate Lead Company (ILCO) is on the National Priorities List. The active site is located in Leads (Jefferson County), Alabama. ILCO is an active lead battery reclamation facility. Slag from reclamation operations was used as fill in 7 known off-site locations. Preliminary on-site sampling results have identified lead (in soil, surface water/sediment, and in groundwater), chromium (in soil and in groundwater), nickel (in soil, in surface water/sediment, and in groundwater), and arsenic (in surface water/sediment and in groundwater). ILCO represents a potential public health concern to area residents through direct contact and ingestion of contaminated soil, and groundwater.

  18. Do Declining Discount Rates lead to Time Inconsistent Economic Advice?

    DEFF Research Database (Denmark)

    Hansen, Anders Chr.

    2006-01-01

    This paper addresses the risk of time inconsistency in economic appraisals related to the use of hyperbolic discounting (declining discount rates) instead of exponential discounting (constant discount rate). Many economists are uneasy about the prospects of potential time inconsistency. The paper...... discusses whether they have reason to be uneasy. The answer is no. The risk of reversing previous recommendations due to the passing of time alone are not severely larger for hyperbolic discounting than it is for exponential discounting. And it can be managed by the same rules of precaution normally used in...

  19. Assessment of photon attenuation characteristics of commercial lead bricks

    International Nuclear Information System (INIS)

    Lead is often used as a shielding material due to its high density and atomic number. Although photon attenuation data are available in literature, it is necessary to test the commercially fabricated lead shielding material experimentally for its radiation shielding efficiency and compare with theoretically computed values of pure lead before putting in to regular use. In the present work, attenuation characteristics of lead supplied by a manufacturing firm was studied for five energy lines

  20. Leaded Paint in Cambodia—Pilot-scale Assessment

    OpenAIRE

    Sereyrath Lim; Thomas Murphy; Kenneth Wilson; Kim N. Irvine

    2015-01-01

    Background. Lead is a heavy metal that is well known to pose a threat to human health. Although the sale and use of lead paint has been banned in much of the developed world, lead is still commonly used in enamel paints in the developing world, including Cambodia. As Cambodia's economy grows, this may increase the purchase and use of lead-based paints, thus potentially exposing more of the population to the toxic effects of lead. Objective. This study was performed to evaluate the concentr...

  1. Real Time Corrosion Monitoring in Lead and Lead-Bismuth Systems

    International Nuclear Information System (INIS)

    The objective of this research program is to develop a real-time, in situ corrosion monitoring technique for flowing liquid Pb and eutectic PbBi (LBE) systems in a temperature range of 400 to 650 C. These conditions are relevant to future liquid metal cooled fast reactor operating parameters. THis program was aligned with the Gen IV Reactor initiative to develp technologies to support the design and opertion of a Pb or LBE-cooled fast reactor. The ability to monitor corrosion for protection of structural components is a high priority issue for the safe and prolonged operation of advanced liquid metal fast reactor systems. In those systems, protective oxide layers are intentionally formed and maintained to limit corrosion rates during operation. This program developed a real time, in situ corrosion monitoring tecnique using impedance spectroscopy (IS) technology.

  2. River basin flood potential inferred using GRACE gravity observations at several months lead time

    Science.gov (United States)

    Reager, J. T.; Thomas, B. F.; Famiglietti, J. S.

    2014-08-01

    The wetness of a watershed determines its response to precipitation, leading to variability in flood generation. The importance of total water storage--which includes snow, surface water, soil moisture and groundwater--for the predisposition of a region to flooding is less clear, in part because such comprehensive observations are rarely available. Here we demonstrate that basin-scale estimates of water storage derived from satellite observations of time-variable gravity can be used to characterize regional flood potential and may ultimately result in longer lead times in flood warnings. We use a case study of the catastrophic 2011 Missouri River floods to establish a relationship between river discharge, as measured by gauge stations, and basin-wide water storage, as measured remotely by NASA's Gravity Recovery and Climate Experiment (GRACE) mission. Applying a time-lagged autoregressive model of river discharge, we show that the inclusion of GRACE-based total water storage information allows us to assess the predisposition of a river basin to flooding as much as 5-11 months in advance. Additional case studies of flood events in the Columbia River and Indus River basins further illustrate that longer lead-time flood prediction requires accurate information on the complete hydrologic state of a river basin.

  3. Assessment of regional human health risks from lead contamination in Yunnan province, southwestern China.

    Science.gov (United States)

    Lu, Lu; Cheng, Hongguang; Liu, Xuelian; Xie, Jing; Li, Qian; Zhou, Tan

    2015-01-01

    Identification and management the 'critical risk areas' where hotspot lead exposures are a potential risk to human health, become a major focus of public health efforts in China. But the knowledge of health risk assessment of lead pollution at regional and national scales is still limited in China. In this paper, under the guidance of 'sources-pathways-receptors' framework, regional human health risk assessment model for lead contamination was developed to calculate the population health risk in Yunnan province. And the cluster and AHP (analytic hierarchy process) analysis was taken to classify and calculate regional health risk and the decomposition of the regional health risk in the greatest health risk region, respectively. The results showed that Yunnan province can be divided into three areas. The highest health risk levels, located in northeastern Yunnan, including Kunming, Qujing, Zhaotong region. In those regions, lead is present at high levels in air, food, water and soil, and high population density which pose a high potential population risk to the public. The current study also reveals that most regional health risk was derived from the child receptors (age above 3 years) 4.3 times than the child receptors (age under 3 years), and ingestion of lead-contaminated rice was found to be the most significant contributor to the health risk (accounting for more than 49% health risk of total). This study can provide a framework for regional risk assessment in China and highlighted some indicators and uncertainties. PMID:25893826

  4. How superluminal motion can lead to backward time travel

    CERN Document Server

    Nemiroff, Robert J

    2015-01-01

    It is commonly asserted that superluminal particle motion can enable backward time travel, but little has been written providing details. It is shown here that the simplest example of a "closed loop" event -- a twin paradox scenario where a single spaceship both traveling out and returning back superluminally -- does {\\it not} result in that ship straightforwardly returning to its starting point before it left. However, a more complicated scenario -- one where the superluminal ship first arrives at an intermediate destination moving subluminally -- can result in backwards time travel. This intermediate step might seem physically inconsequential but is shown to break Lorentz-invariance and be oddly tied to the sudden creation of a pair of spacecraft, one of which remains and one of which annihilates with the original spacecraft.

  5. Assessments of blood lead levels in children with febrile convulsion

    OpenAIRE

    Khosravi, Nastaran; Izadi, Anahita; Noorbakhsh, Samileh; Javadinia, Shima; Tabatabaei, Azardokht; Ashouri, Sarvenaz; Asgarian, Ramin

    2014-01-01

    Background: Lead elements have an adverse effect on human health. The most important complications of lead poisoning are disorders of nervous system particularly seizure .This study aimed to evaluate the blood lead levels and its association with convulsion in a group of hospitalized febrile children. Methods: In this analytic cross-sectional study, 60 hospitalized febrile children with 1- 60 month old participated in the study via non-probability convenience sampling method. All of the infor...

  6. Continuous review inventory models under time value of money and crashable lead time consideration

    Directory of Open Access Journals (Sweden)

    Hung Kuo-Chen

    2011-01-01

    Full Text Available A stock is an asset if it can react to economic and seasonal influences in the management of the current assets. The financial manager must calculate the input of funds to the stock intelligently and the amount of money cycled through stocks, taking into account the time factors in the future. The purpose of this paper is to propose an inventory model considering issues of crash cost and current value. The sensitivity analysis of each parameter, in this research, differs from the traditional approach. We utilize a course of deduction with sound mathematics to develop several lemmas and one theorem to estimate optimal solutions. This study first tries to find the optimal order quantity at all lengths of lead time with components crashed at their minimum duration. Second, a simple method to locate the optimal solution unlike traditional sensitivity analysis is developed. Finally, some numerical examples are given to illustrate all lemmas and the theorem in the solution algorithm.

  7. Distribution and integrated assessment of lead in an abandoned lead-acid battery site in Southwest China before redevelopment.

    Science.gov (United States)

    Wang, Mei; Zhang, Chao; Zhang, Zhuo; Li, Fasheng; Guo, Guanlin

    2016-06-01

    Lead-acid battery sites have contributed enormous amounts of lead to the environment, significantly affecting its global biogeochemical cycle and leaving the potential risks to human health. An abandoned lead-acid battery site prepared for redevelopment was selected in order to study the distribution of lead in soils, plants, rhizosphere soils and soil solutions. In total, 197 samples from 77 boreholes were collected and analyzed. Single extractions by acetic acid (HOAc) were conducted to assess the bioavailability and speciation of lead in soils for comparison with the parts of the plants that are aboveground. Health risks for future residential development were evaluated by the integrated exposure uptake biokinetic (IEUBK) model. The results indicated that lead concentrations in 83% of the soil samples exceeded the Chinese Environmental Quality Standard for soil (350 mg/kg for Pb) and mainly occurred at depths between 0 and 1.5 m while accumulating at the surface of demolished construction waste and miscellaneous fill. Lead concentrations in soil solutions and HOAc extraction leachates were linked closely to the contents of aboveground Broussonetia papyrifera and Artemisia annua, two main types of local plants that were found at the site. The probability density of lead in blood (PbB) in excess of 10 µg/dL could overtake the 99% mark in the residential scenario. The findings provided a relatively integrated method to illustrate the onsite investigations and assessment for similar sites before remediation and future development from more comprehensive aspects. PMID:26921546

  8. Assessment of lead sources for waterfowl in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Exposure to detrimental concentrations of lead has been documented in waterfowl in Alaska. In spectacled eiders (Somateria fischeri) and long-tailed ducks (Clangula...

  9. On the analysis of lead-time disturbances in production and inventory control models

    OpenAIRE

    Spiegler, VLM; Naim, MM; Syntetos, A

    2015-01-01

    Changes in the lead-time can lead to supply chain inefficiencies and risks. In this paper, we investigate the effects of lead-time disturbances on the system’s output responses of a production and inventory control model. In the adaption process of the control system for lead-time disturbance analysis, the resulting model becomes nonlinear. Hence nonlinear control theory in combination with simulation is used to analyse the impact of leadtime changes on the transient and steady state respo...

  10. Functional assessment of time course microarray data

    OpenAIRE

    Dopazo Joaquín; García-García Francisco; Tarazona Sonia; Sebastián Patricia; Nueda María; Ferrer Alberto; Conesa Ana

    2009-01-01

    Abstract Motivation Time-course microarray experiments study the progress of gene expression along time across one or several experimental conditions. Most developed analysis methods focus on the clustering or the differential expression analysis of genes and do not integrate functional information. The assessment of the functional aspects of time-course transcriptomics data requires the use of approaches that exploit the activation dynamics of the functional categories to where genes are ann...

  11. Study of Client Reject Policies under Lead-Time and Price Dependent Demand

    OpenAIRE

    Albana, Abduh Sayid; Frein, Yannick; Hammami, Ramzi

    2016-01-01

    Delivery lead-time has become a factor of competitiveness for companies and an important criterion of purchase for the customers today. Thus, in order to increase their profit, companies must not focus only on price but also need to quote the right delivery lead time to their customers. Some authors to find a way in quoting the right delivery lead-time while considering an M/M/1 system. In M/M/1, all customers are accepted. This can lead to longer lead times in the queue. Firms can react by q...

  12. Research Project: Assessment of Lead in Air of Guatemala City

    International Nuclear Information System (INIS)

    In this report all the activities concerning to quality of air in the city of Guatemala are considered. By measurements of lead in filters of air sampling using voltametry, the quality of air is going to be compared with international standards

  13. Assessment of Lead Chalcogenide Nanostructures as Possible Thermoelectric Materials

    OpenAIRE

    Gabriel, Stefanie

    2013-01-01

    The assembly of nanostructures into “multi”-dimensional materials is one of the main topics occurring in nanoscience today. It is now possible to produce high quality nanostructures reproducibly but for their further application larger structures that are easier to handle are required. Nevertheless during their assembly their nanometer size and accompanying properties must be maintained. This challenge was addressed in this work. Lead chalcogenides have been chosen as an example system becaus...

  14. Assessment of Lead Discrimination from CryoSat-2

    OpenAIRE

    Kildegaard Rose, Stine; Connor, L. N.; Newman, T.; S. L. Farrell; Smith, W. H.; Forsberg, René

    2012-01-01

    Sea ice is strongly affecting the global climate, and the sea ice extent has been monitored by satellites since 1979. To estimate the Arctic sea ice volume, ice thickness must be determined. The measurements of sea ice thickness are however more difficult to achieve, and encounter limitations due to spatial and temporal variability. The measurements of sea ice freeboard may be used to estimate sea ice thickness, when combined with examination of leads between ice floes to determine the local ...

  15. Comparative assessment of thermophysical and thermohydraulic characteristics of lead, lead-bismuth and sodium coolants for fast reactors

    International Nuclear Information System (INIS)

    All prototype, demonstration and commercial liquid metal cooled fast reactors (LMFRs) have used liquid sodium as a coolant. Sodium cooled systems, operating at low pressure, are characterised by very large thermal margins relative to the coolant boiling temperature and a very low structural material corrosion rate. In spite of the negligible thermal energy stored in the liquid sodium available for release in case of leakage, there is some safety concern because of its chemical reactivity with respect to air and water. Lead, lead-bismuth or other alloys of lead, appear to eliminate these concerns because the chemical reactivity of these coolants with respect to air and water is very low. Some experts believe that conceptually, these systems could be attractive if high corrosion activity inherent in lead, long term materials compatibility and other problems will be resolved. Extensive research and development work is required to meet this goal. Preliminary studies on lead-bismuth and lead cooled reactors and ADS (accelerator driven systems) have been initiated in France, Japan, the United States of America, Italy, and other countries. Considerable experience has been gained in the Russian Federation in the course of development and operation of reactors cooled with lead-bismuth eutectic, in particular, propulsion reactors. Studies on lead cooled fast reactors are also under way in this country. The need to exchange information on alternative fast reactor coolants was a major consideration in the recommendation by the Technical Working Group on Fast Reactors (TWGFRs) to collect, review and document the information on lead and lead-bismuth alloy coolants: technology, thermohydraulics, physical and chemical properties, as well as to make an assessment and comparison with respective sodium characteristics

  16. Functional assessment of time course microarray data

    Science.gov (United States)

    Nueda, María José; Sebastián, Patricia; Tarazona, Sonia; García-García, Francisco; Dopazo, Joaquín; Ferrer, Alberto; Conesa, Ana

    2009-01-01

    Motivation Time-course microarray experiments study the progress of gene expression along time across one or several experimental conditions. Most developed analysis methods focus on the clustering or the differential expression analysis of genes and do not integrate functional information. The assessment of the functional aspects of time-course transcriptomics data requires the use of approaches that exploit the activation dynamics of the functional categories to where genes are annotated. Methods We present three novel methodologies for the functional assessment of time-course microarray data. i) maSigFun derives from the maSigPro method, a regression-based strategy to model time-dependent expression patterns and identify genes with differences across series. maSigFun fits a regression model for groups of genes labeled by a functional class and selects those categories which have a significant model. ii) PCA-maSigFun fits a PCA model of each functional class-defined expression matrix to extract orthogonal patterns of expression change, which are then assessed for their fit to a time-dependent regression model. iii) ASCA-functional uses the ASCA model to rank genes according to their correlation to principal time expression patterns and assess functional enrichment on a GSA fashion. We used simulated and experimental datasets to study these novel approaches. Results were compared to alternative methodologies. Results Synthetic and experimental data showed that the different methods are able to capture different aspects of the relationship between genes, functions and co-expression that are biologically meaningful. The methods should not be considered as competitive but they provide different insights into the molecular and functional dynamic events taking place within the biological system under study. PMID:19534758

  17. Assessment of Lead Discrimination from CryoSat-2

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Connor, L. N.; Newman, T.;

    to spatial and temporal variability. The measurements of sea ice freeboard may be used to estimate sea ice thickness, when combined with examination of leads between ice floes to determine the local sea surface height. With CryoSat-2 (CS), we have the opportunity to measure much more of the Arctic Ocean due...... to its high sampling rate and geographical coverage to 88 oN/S. Validation of the CS retrievals are very important to verify the derived sea ice thickness and understand the associated error sources. We present a comparative analysis of CryoSat-2 elevations with the Operation IceBridge Airborne...

  18. Sustainable Building Assessment Tool: Indian Leading Architects' Perceptions and Preferences

    Science.gov (United States)

    Bhatt, R.; Macwan, J. E. M.; Bhatt, D.

    2012-12-01

    As `sustainable development' has become a global focus, "Green Building" or "Sustainable Building (SB)" is the need of the day. These buildings not only reduce negative environmental impact but also improve human comfort and safety. Sustainable Buildings need to be assessed by `Assessment tool' for checking its overall contribution towards achievement of `sustainability'. In this paper an attempt is made to know Indian Architects `perceptions' and `preferences' regarding the framework of "Sustainable Building Assessment Tool (SBAT)" for India. Feedbacks were collected from the Architects of major metro cities of India. Total 81 responses were analyzed with SPSS 12 statistical analysis software. Indian Architects' gave an opinion that `SBAT' for India should be prepared firstly for commercial buildings. It should target `Architects' first and must be applied at the building level. `SBAT' should be a comprehensive one with flexible and easy to calculate scoring system. `SBAT' must cover non-controllable factors along with negative scoring system. Results can be utilized in the coming years to prepare a comprehensive `SBAT' for developing country like India.

  19. Efficient Inventory Optimization of Multi Product, Multiple Suppliers with Lead Time using PSO

    CERN Document Server

    Narmadha, S; Sathish, G

    2010-01-01

    With information revolution, increased globalization and competition, supply chain has become longer and more complicated than ever before. These developments bring supply chain management to the forefront of the managements attention. Inventories are very important in a supply chain. The total investment in inventories is enormous, and the management of inventory is crucial to avoid shortages or delivery delays for the customers and serious drain on a companys financial resources. The supply chain cost increases because of the influence of lead times for supplying the stocks as well as the raw materials. Practically, the lead times will not be same through out all the periods. Maintaining abundant stocks in order to avoid the impact of high lead time increases the holding cost. Similarly, maintaining fewer stocks because of ballpark lead time may lead to shortage of stocks. This also happens in the case of lead time involved in supplying raw materials. A better optimization methodology that utilizes the Part...

  20. Integrated vendor-buyer inventory models with inflation and time value of money in controllable lead time

    OpenAIRE

    Prashant Jindal; Anjana Solanki

    2016-01-01

    In the global critical economic scenario, inflation plays a vital role in deciding optimal pricing of goods in any business entity. This article presents two single-vendor single-buyer integrated supply chain inventory models with inflation and time value of money. Shortage is allowed during the lead-time and it is partially backlogged. Lead time is controllable and can be reduced using crashing cost. In the first model, we consider the demand of lead time follows a normal distribution, and i...

  1. Integrated vendor-buyer inventory models with inflation and time value of money in controllable lead time

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-01-01

    Full Text Available In the global critical economic scenario, inflation plays a vital role in deciding optimal pricing of goods in any business entity. This article presents two single-vendor single-buyer integrated supply chain inventory models with inflation and time value of money. Shortage is allowed during the lead-time and it is partially backlogged. Lead time is controllable and can be reduced using crashing cost. In the first model, we consider the demand of lead time follows a normal distribution, and in the second model, it is considered distribution-free. For both cases, our objective is to minimize the integrated system cost by simultaneously optimizing the order quantity, safety factor, lead time and number of lots. The discounted cash flow and classical optimization technique are used to derive the optimal solution for both cases. Numerical examples including the sensitivity analysis of system parameters is provided to validate the results of the supply chain models.

  2. Assessment of Regional Human Health Risks from Lead Contamination in Yunnan Province, Southwestern China

    OpenAIRE

    Lu, Lu; Cheng, Hongguang; Liu, XueLian; Xie, Jing; Li, Qian; Zhou, Tan

    2015-01-01

    Identification and management the 'critical risk areas' where hotspot lead exposures are a potential risk to human health, become a major focus of public health efforts in China. But the knowledge of health risk assessment of lead pollution at regional and national scales is still limited in China. In this paper, under the guidance of 'sources-pathways-receptors' framework, regional human health risk assessment model for lead contamination was developed to calculate the population health risk...

  3. ADVANCEMENTS IN TIME-SPECTRA ANALYSIS METHODS FOR LEAD SLOWING-DOWN SPECTROSCOPY

    International Nuclear Information System (INIS)

    Direct measurement of Pu in spent nuclear fuel remains a key challenge for safeguarding nuclear fuel cycles of today and tomorrow. Lead slowing-down spectroscopy (LSDS) is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic mass with an uncertainty lower than the approximately 10 percent typical of today's confirmatory assay methods. Pacific Northwest National Laboratory's (PNNL) previous work to assess the viability of LSDS for the assay of pressurized water reactor (PWR) assemblies indicated that the method could provide direct assay of Pu-239 and U-235 (and possibly Pu-240 and Pu-241) with uncertainties less than a few percent, assuming suitably efficient instrumentation, an intense pulsed neutron source, and improvements in the time-spectra analysis methods used to extract isotopic information from a complex LSDS signal. This previous simulation-based evaluation used relatively simple PWR fuel assembly definitions (e.g. constant burnup across the assembly) and a constant initial enrichment and cooling time. The time-spectra analysis method was founded on a preliminary analytical model of self-shielding intended to correct for assay-signal nonlinearities introduced by attenuation of the interrogating neutron flux within the assembly.

  4. Leading in times of crisis navigating through complexity, diversity and uncertainty to save your business

    CERN Document Server

    Dotlich, David L; Rhinesmith, Stephen H

    2009-01-01

    Praise for Leading in Times of Crisis ""Building on the solid base of their book Head, Heart, and Guts, Dotlich, Cairo, and Rhinesmith lay out the ways to become the kind of leader needed to navigate through today''s complexities and uncertainties. Leading in Times of Crisis is a necessary guidebook to survive and thrive in the global perfect storm.""-John Naisbitt, author, Megatrends and Megatrends 2000 ""The risks and opportunities that confront today''s leader have never been greater. Leading in Times of Crisis provides unique and valuable insights, along with straightforward principles, th

  5. Periodic inventory model with controllable lead time where backorder rate depends on protection interval

    Directory of Open Access Journals (Sweden)

    Chandra K Jaggi

    2014-04-01

    Full Text Available In this paper, a period review inventory model with controllable lead time has been considered where shortages are partially backlogged. The backorder rate is dependent on the backorder discount and the length of the protection interval, which is sum of the review period and the lead time. Two cases have been discussed for protection interval demand which are (a Demand distribution is known (Normal Distribution (b Demand distribution is unknown (Minimax distribution. Further, algorithms have been developed which jointly optimize the backorder discount, the review period and the lead time for each case. Numerical examples are also presented to illustrate the results.

  6. Seismic assessment of a site using the time series method

    International Nuclear Information System (INIS)

    To increase the safety of a NPP located on a seismic site, the seismic acceleration level to which the NPP should be qualified must be as representative as possible for that site, with a conservative degree of safety but not too exaggerated. The consideration of the seismic events affecting the site as independent events and the use of statistic methods to define some safety levels with very low annual occurrence probability (10-4) may lead to some exaggerations of the seismic safety level. The use of some very high value for the seismic acceleration imposed by the seismic safety levels required by the hazard analysis may lead to very costly technical solutions that can make the plant operation more difficult and increase maintenance costs. The considerations of seismic events as a time series with dependence among the events produced, may lead to a more representative assessment of a NPP site seismic activity and consequently to a prognosis on the seismic level values to which the NPP would be ensured throughout its life-span. That prognosis should consider the actual seismic activity (including small earthquakes in real time) of the focuses that affect the plant site. The paper proposes the applications of Autoregressive Time Series to issue a prognosis on the seismic activity of a focus and presents the analysis on Vrancea focus that affects NPP Cernavoda site, by this method. The paper also presents the manner to analyse the focus activity as per the new approach and it assesses the maximum seismic acceleration that may affect NPP Cernavoda throughout its life-span (∼ 30 years). Development and applications of new mathematical analysis method, both for long - and short - time intervals, may lead to important contributions in the process of foretelling the seismic events in the future. (authors)

  7. Critical spare parts ordering decisions using conditional reliability and stochastic lead time

    International Nuclear Information System (INIS)

    Asset-intensive companies face great pressure to reduce operation costs and increase utilization. This scenario often leads to over-stress on critical equipment and its spare parts associated, affecting availability, reliability, and system performance. As these resources impact considerably on financial and operational structures, the opportunity is given by demand for decision-making methods for the management of spare parts processes. We proposed an ordering decision-aid technique which uses a measurement of spare performance, based on the stress–strength interference theory; which we have called Condition-Based Service Level (CBSL). We focus on Condition Managed Critical Spares (CMS), namely, spares which are expensive, highly reliable, with higher lead times, and are not available in store. As a mitigation measure, CMS are under condition monitoring. The aim of the paper is orienting the decision time for CMS ordering or just continuing the operation. The paper presents a graphic technique which considers a rule for decision based on both condition-based reliability function and a stochastic/fixed lead time. For the stochastic lead time case, results show that technique is effective to determine the time when the system operation is reliable and can withstand the lead time variability, satisfying a desired service level. Additionally, for the constant lead time case, the technique helps to define insurance spares. In conclusion, presented ordering decision rule is useful to asset managers for enhancing the operational continuity affected by spare parts

  8. A Real Time Dose Assessment System

    International Nuclear Information System (INIS)

    The construction of the second Egyptian Research Reactor ETRR-2 at Anshas area in the same site as the first Egyptian Research Reactor ETRR-1 together with all the other nuclear Laboratories and installations necessitates the presence of a real time dose assessment system (RTDAS). The RTDAS as a part of an overall decision making aid, will help the emergency response manager to consolidate decisions regarding the required management of an off-site emergency. The present work describes a proposed dose assessment system based on a Geographical Information System (GIS). The system consists of Hardware and Software parts. The Hardware includes radiation-monitoring equipment connected to a central computer. The real time model is designed for operational use so it can provide decisions makers with information about the probable future consequences of an accidental release of radioactivity almost immediately of few minutes of receipt of the appropriate information. The output information from the model can be presented in terms of dose estimates for population at risk and can be displayed either as tabulated data or as dose contours superimposed upon a map of the area

  9. Exponential Smoothing for Inventory Control: Means and Variances of Lead-Time Demand

    OpenAIRE

    Ralph D. Snyder; Anne B. Koehler; Hyndman, Rob J.; J. Keith Ord

    2002-01-01

    Exponential smoothing is often used to forecast lead-time demand for inventory control. In this paper, formulae are provided for calculating means and variances of lead-time demand for a wide variety of exponential smoothing methods. A feature of many of the formulae is that variances, as well as the means, depend on trends and seasonal effects. Thus, these formulae provide the opportunity to implement methods that ensure that safety stocks adjust to changes in trend or changes in season.

  10. Economic Ordering Quantity Model with Lead Time Reduction and Backorder Price Discount for Stochastic Demand

    OpenAIRE

    Ming-Cheng Lo

    2009-01-01

    This study considered reorder point on the continuous review inventory model under controllable lead time with mixture of backorder price discounts and partial lost sales. We developed a continuous review inventory model where the lead time, the order quantity, backorder discount and safety factor were considered as the decision variables of a mixture of backorders and lost sales inventory model. The objective was to minimize the expected total annual cost with respect to related decision var...

  11. Periodic inventory model with controllable lead time where backorder rate depends on protection interval

    OpenAIRE

    Jaggi, Chandra K.; Haider Ali; Neetu Arneja

    2014-01-01

    In this paper, a period review inventory model with controllable lead time has been considered where shortages are partially backlogged. The backorder rate is dependent on the backorder discount and the length of the protection interval, which is sum of the review period and the lead time. Two cases have been discussed for protection interval demand which are (a) Demand distribution is known (Normal Distribution) (b) Demand distribution is unknown (Minimax distribution). Further, algorithms h...

  12. Modeling a no-shortage, long-uncertain-lead-time, inventory system with simulation

    International Nuclear Information System (INIS)

    A discrete predicted demand, no-shortage, long-term uncertain lead time inventory system is simulated by GASP IV. The sizes of the individual demands are dependent on the selling price which is determined by the holding costs. A GASP IV simulation model interfaces a CPM lead time module and a demand prediction module in order to maximize the percent of total demand versus on-hand inventory. This work is pertinent to nuclear fuels. 4 refs

  13. Improved Base-Stock Approximations for Independent Stochastic Lead Times with Order Crossover

    OpenAIRE

    James R. Bradley; Lawrence W. Robinson

    2005-01-01

    Order crossovers occur when replenishment orders arrive in a sequence that is different than the one in which they were placed. Order crossovers require that optimal reorder levels be set with regard to the inventory shortfall distribution rather than the lead-time demand distribution. Assuming periodic review and independent lead times, this paper suggests simple approximations of the shortfall distribution by showing that the variance of the number of orders outstanding is bounded above by ...

  14. Planning Electric Power Systems Under Demand Uncertainty with Different Technology Lead Times

    OpenAIRE

    Douglas T. Gardner; J. Scott Rogers

    1999-01-01

    Demand uncertainty is a key concern of electric utility planners. While the greater use of short lead time technologies provides one possible way to deal with this problem, it is not clear how they are best deployed. The approach taken in this paper is to examine a capacity mix model that explicitly accounts for differences in technology lead times. Key results that are obtained include the characterization of the optimal solution and the development of a new set of technology screening crite...

  15. THE LEARNING EFFECT ON SETUP COST REDUCTION FOR MIXTURE INVENTORY MODELS WITH VARIABLE LEAD TIME

    OpenAIRE

    JASON CHAO-HSIEN PAN; MING-CHENG LO

    2008-01-01

    This paper investigates the impact of learning curve effect on setup cost for the continuous review inventory model involving controllable lead time with the mixture of backorder and partial lost sales. A learning curve is a well known tool which describes the relation between the performance of a task and the number of repetitions of that task. The objective of this study is to minimize the expected total annual cost by simultaneously optimizing order quantity, safety factor and lead time un...

  16. Integrated supply chain inventory model with quality improvement involving controllable lead time and backorder price discount

    OpenAIRE

    Prashant Jindal; Anjana Solanki

    2016-01-01

    For the past four decades the integrated vendor and buyer supply chain inventory model has been an interesting topic, but quality improvement of defective items in the integrated inventory model with backorder price discount involving controllable lead time has been rarely discussed. The aim of this paper is to minimize the total related cost in the continuous review model by considering the order quantity, reorder point, lead time, process quality, backorder price discount and number of ship...

  17. Reducing Inventory and Optimizing the Lead time in a Custom order, High model mix Environment

    OpenAIRE

    Salian, Shilpashree

    2016-01-01

    In this contemporary world, demand forecasting has become an effective tool for the success of any product organization. This is especially important when their components have long lead times and when the companies don’t build on order. The goal of this thesis is to reduce inventory by improving the forecast accuracy while maintaining customer lead time in a custom order, high mix model environment.   In this master thesis investigation, the research questions that were formulated are answer...

  18. Ensemble forecasts of monthly catchment rainfall out to long lead times by post-processing coupled general circulation model output

    Science.gov (United States)

    Schepen, Andrew; Wang, Q. J.

    2014-11-01

    Monthly streamflow forecasts with long lead time are being sought by water managers in Australia. In this study, we take a first step towards a monthly streamflow modelling approach by harnessing a coupled ocean-atmosphere general circulation model (CGCM) to produce monthly rainfall forecasts for three catchments across Australia. Bayesian methodologies are employed to produce forecasts based on CGCM raw rainfall forecasts and also CGCM sea surface temperature forecasts. The Schaake Shuffle is used to connect forecast ensemble members of individual months to form ensemble monthly time series forecasts. Monthly forecasts and three-monthly forecasts of rainfall are assessed for lead times of 0-6 months, based on leave-one-year-out cross-validation for 1980-2010. The approach is shown to produce well-calibrated ensemble forecasts that source skill from both the atmospheric and ocean modules of the CGCM. Although skill is generally low, moderate skill scores are observed in some catchments for lead times of up to 6 months. In months and catchments where there is limited skill, the forecasts revert to climatology. Thus the forecasts developed can be considered suitable for continuously forecasting time series of streamflow to long lead times, when coupled with a suitable monthly hydrological model.

  19. Inventory Model (M,T With Quadratic Backorder Costs And Continuous Lead Time Series 1

    Directory of Open Access Journals (Sweden)

    Dr. Martin Osawaru Omorodion

    2014-07-01

    Full Text Available We have assumed in this paper that demand follows a normal distribution, and lead times follow a gamma distribution and backorder costs is quadratic. The (M, T Model an order is made to bring it to M at review time. The model is derived from the (nQ,R,T model which at review time an integral multiple Q is ordered. After deriving the inventory costs for (nQ, R,T we set Q 0 to obtain the (M,T inventory costs by making use of the differentiation of the (nQ,R,T model. The (M,T inventory costs for constant lead times is then averaged over the states of the lead times. Extensive use is made of the Bessel functions of imaginary argument

  20. Minimum dispersion in leading edge timing with coaxial Ge(Li) detectors

    International Nuclear Information System (INIS)

    Time variances due to systematic walk and noise jitter are analytically performed as a function of integration time in leading-edge timing with coaxial Ge(Li) detectors for several values of the trigger fraction and the geometrical factor. This reveals the existence of a minimum in the curve which represents the total timing error vs the integration time constant. The best time resolution of a specified detector is achieved when the RC-filtered signal has a time constant (in ns) that is numerically equal to the thickness (in mm) of the detector depletion layer. (orig.)

  1. Infinitesimal dividing modeling method for dual suppliers inventory model with random lead times

    Institute of Scientific and Technical Information of China (English)

    Ji Pengcheng; Song Shiji; Wu Cheng

    2009-01-01

    As one of the basic inventory cost models, the (Q, r) inventory cost model of dual suppliers with random procurement lead time is mostly formulated by using the concepts of "effective lead time" and "lead time demand", which may lead to an imprecise inventory cost. Through the real-time statistic of the inventory quantities, this paper considers the precise (Q, r) inventory cost model of dual supplier procurement by using an infinitesimal dividing method. The traditional modeling method of the inventory cost for dual supplier procurement includes complex procedures. To reduce the complexity effectively, the presented method investigates the statistics properties in real-time of the inventory quantities with the application of the infinitesimal dividing method. It is proved that the optimal holding and shortage costs of dual supplier procurement are less than those of single supplier procurement respectively. With the assumption that both suppliers have the same distribution of lead times, the convexity of the cost function per unit time is proved. So the optimal solution can be easily obtained by applying the classical convex optimization methods. The numerical examples are given to verify the main conclusions.

  2. Effective use of general circulation model outputs for forecasting monthly rainfalls to long lead times

    Science.gov (United States)

    Hawthorne, Sandra; Wang, Q. J.; Schepen, Andrew; Robertson, David

    2013-09-01

    Long lead rainfall forecasts are highly valuable for planning and management of water resources and agriculture. In this study, we establish multiple statistical calibration and bridging models that use general circulation model (GCM) outputs as predictors to produce monthly rainfall forecasts for Australia with lead times up to 8 months. The statistical calibration models make use of raw forecasts of rainfall from a coupled GCM, and the statistical bridging models make use of sea surface temperature (SST) forecasts of the GCM. The forecasts from the multiple models are merged through Bayesian model averaging to take advantage of the strengths of individual models. The skill of monthly rainfall forecasts is generally low. Compared to forecasting seasonal rainfall totals, it is more challenging to forecast monthly rainfall. However, there are regions and months for which forecasts are skillful. In particular, there are months of the year for which forecasts can be skillfully made at long lead times. This is most evident for the period of November and December. Using GCM forecasts of SST through bridging clearly improves monthly rainfall forecasts. For lead time 0, the improvement is particularly evident for February to March, July and October to December. For longer lead times, the benefit of bridging is more apparent. As lead time increases, bridging is able to maintain forecast skill much better than when only calibration is applied.

  3. Laser Vision Measurement System and Assessment Method for SMIC Lead Coplanarity

    Institute of Scientific and Technical Information of China (English)

    SUN Changku; QIU Yu; XUE Xiaojie; YE Shenghua

    2000-01-01

    In this paper, a successful application of line-structured laser sensor, involved in SMIC chip lead coplanarity measurement, is presented. With the experimental measurement system and its corresponding mathematics model, a contact-datum-plane assessment of SMIC chip lead coplanarity is developed to provide method for on-line measurement.

  4. 75 FR 69078 - Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA)

    Science.gov (United States)

    2010-11-10

    ... AGENCY Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA) AGENCY... a workshop to evaluate initial draft materials for the Pb Integrated Science Assessment (ISA) is... within each discipline to assist EPA in integrating within and across disciplines. This workshop...

  5. Development and assessment of flow rate measurement techniques for lead-bismuth

    International Nuclear Information System (INIS)

    Full text of publication follows: Thermohydraulic investigations in liquid lead or lead-bismuth flows, which are necessary for the design of an Accelerator Driven System (ADS) for nuclear waste transmutation, are raising the need for powerful flow measuring techniques. Due to the hostile physical and chemical properties of lead bismuth (PbBi) even the reliable determination of the flow rate is a difficult task. In this paper we present the results of the experimental investigations on four different flow rate measurement techniques for liquid lead-bismuth. In detail there are two magnetic inductive based methods, a permanent magnet flowmeter (PMF) and an electromagnetic frequency flowmeter (EMFM), a turbine flowmeter and an ultrasound transit time system (USTT). For each technique the development of the dedicated measuring device and its application to the Technology Loop THESYS at the Karlsruhe Lead Laboratory is described. The measurement matrix for the experiments contains four different flow rates, controlled by the power of the electromagnetic pump, at different lead-bismuth temperatures between 200 deg. C and 400 deg. C. At each pump power level the effect of the temperature variations on the measuring instrument is recorded. The presentation of the obtained results is divided into two parts. First, the operating behaviour of the flow meters in the liquid lead-bismuth flow is discussed, concerning the long term stability and the material compatibility of the manufactured devices. Second, the acquired data from the meters are analyzed and assessed with respect to accuracy, linearity and response time. A strong temperature dependency of the PMF signal with irregular instabilities was observed, because it depends on the contact resistance at the interface between the PbBi and the structure material. The change of this resistance due to wetting effects or deposition of impurities induces severe discontinuities in the signal. In contrast, the EMFM principle

  6. Time trends in burdens of cadmium, lead, and mercury in the population of northern Sweden

    International Nuclear Information System (INIS)

    The time trends of exposure to heavy metals are not adequately known. This is a worldwide problem with regard to the basis for preventive actions and evaluation of their effects. This study addresses time trends for the three toxic elements cadmium (Cd), mercury (Hg), and lead (Pb). Concentrations in erythrocytes (Ery) were determined in a subsample of the population-based MONICA surveys from 1990, 1994, and 1999 in a total of 600 men and women aged 25-74 years. The study took place in the two northernmost counties in Sweden. To assess the effect of changes in the environment, adjustments were made for life-style factors that are determinants of exposure. Annual decreases of 5-6% were seen for Ery-Pb levels (adjusted for age and changes in alcohol intake) and Ery-Hg levels (adjusted for age and changes in fish intake). Ery-Cd levels (adjusted for age) showed a similar significant decrease in smoking men. It is concluded that for Pb and maybe also Hg the actions against pollution during recent decades have caused a rapid decrease of exposure; for Hg the decreased use of dental amalgam may also have had an influence. For Cd, the decline in Ery-Cd was seen only in smokers, indicating that Cd exposure from tobacco has decreased, while other environmental sources of Cd have not changed significantly. To further improve the health status in Sweden, it is important to decrease the pollution of Cd, and actions against smoking in the community are important

  7. Application of IEUBK model in lead risk assessment of children aged 61-84 months old in central China.

    Science.gov (United States)

    Li, Yanyan; Hu, Jia; Wu, Wei; Liu, Shuyun; Li, Mei; Yao, Na; Chen, Jianwei; Ye, Linxiang; Wang, Qi; Zhou, Yikai

    2016-01-15

    Few studies have focused on the accuracy of using the Integrated Exposure Uptake Biokinetic (IEUBK) model in Chinese children with site- and age-specific exposure data. This study aimed to validate the accuracy and sensitivity of the IEUBK model in lead risk assessment of Chinese children aged 61-84 months old. A total of 760 children were enrolled from two respective counties in Central China by using random cluster sampling method. Blood lead levels (BLLs) of all subjects were determined using graphite furnace atomic absorption spectrometry, as well as that in the environmental media, such as air, drinking water, soil, dust and food. Age- and site-specific time-activity patterns and water consumption were evaluated by using questionnaires for children. Exposure parameters including outdoor and indoor activity time, ventilation rate and water consumption in this study were different from the default values of the IEUBK model. Statistical analysis revealed no significant differences between the predicted and observed BLLs. Diet and soil/dust lead intake contributed approximately 83.39% (57.40%-93.84% range) and 15.18% (3.25%-41.60% range) of total lead intake, respectively. These findings showed that the IEUBK model is suitable for lead risk assessment of Chinese children aged 61-84 months old and diet acts as an important lead source. PMID:26433329

  8. A study on ignition characteristic with supply leading time of propellants in liquid rocket engine

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.; Kim, Y.W.; Kim, Y.H.; Lee, J.Y.; Chung, Y.G.; Cho, N.K. [Korea Aerospace Research Institute, Taejeon (Korea)

    2000-11-01

    Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignition process with liquid rocket engine. The propellant used is a Kerosene as fuel and a liquid oxygen as oxidizer. FOOF type of three injectors are set with an angle of 135 deg. and the combustion chamber pressure is 200psi. The present experiment program also includes the stability on the quadlet type of ignitor using the triethylaluminum(TEAL) as an ignition source. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time of propellants affects the engine performance little. (author). 16 refs., 8 figs.

  9. Economic Ordering Quantity Model with Lead Time Reduction and Backorder Price Discount for Stochastic Demand

    Directory of Open Access Journals (Sweden)

    Ming-Cheng Lo

    2009-01-01

    Full Text Available This study considered reorder point on the continuous review inventory model under controllable lead time with mixture of backorder price discounts and partial lost sales. We developed a continuous review inventory model where the lead time, the order quantity, backorder discount and safety factor were considered as the decision variables of a mixture of backorders and lost sales inventory model. The objective was to minimize the expected total annual cost with respect to related decision variables. The purpose model with lead time demand distribution was unknown. The author applies a minimax distribution free procedure to find the optimal solution and numerical example was included to illustrate the solution procedure of the proposed algorithms.

  10. ANALYSIS AND IMPROVEMENT OF LEAD TIME FOR JOB SHOP UNDER MIXED PRODUCTION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    CHE Jianguo; HE Zhen; EDWARB M Knod

    2006-01-01

    Firstly an overview of the potential impact on work-in-process (WIP) and lead time is provided when transfer lot sizes are undifferentiated from processing lot sizes. Simple performance examples are compared to those from a shop with one-piece transfer lots. Next, a mathematical programming model for minimizing lead time in the mixed-model job shop is presented, in which one-piece transfer lots are used. Key factors affecting lead time are found by analyzing the sum of the longest setup time of individual items among the shared processes (SLST) and the longest processing time of individual items among processes (LPT). And lead time can be minimized by cutting down the SLST and LPT. Reduction of the SLST is described as a traveling salesman problem (TSP), and the minimum of the SLST is solved through job shop scheduling. Removing the bottleneck and leveling the production line optimize the LPT. If the number of items produced is small, the routings are relatively short, and items and facilities are changed infrequently, the optimal schedule will remain valid. Finally a brief example serves to illustrate the method.

  11. Overestimated lead times in cancer screening has led to substantial underestimation of overdiagnosis

    DEFF Research Database (Denmark)

    Zahl, P-H; Juhl Jørgensen, Karsten; Gøtzsche, P C

    2013-01-01

    Published lead time estimates in breast cancer screening vary from 1 to 7 years and the percentages of overdiagnosis vary from 0 to 75%. The differences are usually explained as random variations. We study how much can be explained by using different definitions and methods.......Published lead time estimates in breast cancer screening vary from 1 to 7 years and the percentages of overdiagnosis vary from 0 to 75%. The differences are usually explained as random variations. We study how much can be explained by using different definitions and methods....

  12. Determining Safety Stock in the Presence of Stochastic Lead Time and Demand

    OpenAIRE

    Gary D. Eppen; R. Kipp Martin

    1988-01-01

    We consider the problem of setting safety stock when both the demand in a period and the lead time are random variables. There are two cases to consider. In the first case the parameters of the demand and lead time distributions are known; in the second case they are unknown and must be estimated. For the case of known parameters a standard procedure is presented in the literature. In this paper, examples are used to show that this procedure can yield results that are far from the desired res...

  13. The Nonstationary Stochastic Lead-Time Inventory Problem: Near-Myopic Bounds, Heuristics, and Testing

    OpenAIRE

    Ravi Anupindi; Thomas E. Morton; David Pentico

    1996-01-01

    The purpose of the current paper is to combine the classical results of Kaplan (Kaplan, R. 1970. Dynamic inventory model with stochastic lead times. Management Sci. 16(2) 491--507.) and Ehrhardt (Ehrhardt, R. 1984. (s, S) Policies for a dynamic inventory model with stochastic lead times. Oper. Res. 32(1) 121--132.) for stochastic leadtime problems with recent work of Morton and Pentico (Morton, T., D. Pentico. 1995. The finite horizon nonstationary stochastic inventory problem near-myopic bou...

  14. Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios

    Energy Technology Data Exchange (ETDEWEB)

    Camizuli, E., E-mail: estelle.camizuli@u-bourgogne.fr [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Monna, F. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Bermond, A.; Manouchehri, N.; Besançon, S. [Institut des sciences et industries du vivant et de l' environnement (AgroParisTech), Laboratoire de Chimie Analytique, 16, rue Claude Bernard, 75231 Paris Cedex 05 (France); Losno, R. [UMR 7583, LISA, Universités Paris 7-Paris 12 — CNRS, 61 av. du Gal de Gaulle, 94010 Créteil Cedex (France); Oort, F. van [UR 251, Pessac, Institut National de la Recherche Agronomique, Centre de Versailles-Grignon, RD 10, 78026 Versailles Cedex (France); Labanowski, J. [UMR 7285, IC2MP, Université de Poitiers — CNRS, 4, rue Michel Brunet, 86022 Poitiers (France); Perreira, A. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Chateau, C. [UFR SVTE, Université de Bourgogne, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Alibert, P. [UMR 6282, Biogeosciences, Université de Bourgogne — CNRS, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France)

    2014-02-01

    The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km{sup 2} zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the “labile” and “less labile” pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the “labile” and “less labile” lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota. - Highlights: • Trace

  15. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    International Nuclear Information System (INIS)

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 μm diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: ► Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. ► Pb analyses acquired for dentine growth increments of 42 days. ► Highly correlated Pb concentration profiles for pairs of deciduous molars. ► Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  16. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Thomas J., E-mail: shepherdtj@aol.com [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Dirks, Wendy [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Manmee, Charuwan; Hodgson, Susan [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Banks, David A. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Averley, Paul [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Queensway Dental Practice, 170 Queensway, Billingham, Teesside TS23 2NT (United Kingdom); Pless-Mulloli, Tanja [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Newcastle Institute for Research on Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2012-05-15

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 {mu}m diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: Black-Right-Pointing-Pointer Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. Black-Right-Pointing-Pointer Pb analyses acquired for dentine growth increments of 42 days. Black-Right-Pointing-Pointer Highly correlated Pb concentration profiles for pairs of deciduous molars. Black-Right-Pointing-Pointer Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  17. LEADING INDICATORS FOR REGIONAL COTTON RESPONSE: STRUCTURAL AND TIME SERIES MODELING RESULTS

    OpenAIRE

    Stavriotis, Paul A.; Houston, Jack E.; McIntosh, Christopher S.; Turner, Steven C.

    1998-01-01

    Resurging southeastern cotton production compels better cotton acreage forecasts for planning seed, chemical, and other input requirements. Structural models describe leading acreage response indicators, and forecasts are compared time-series models. Cotton price, loan rate, deficiency payments, lagged corn acreage, the PIK program, and previous cotton yield significantly influence response.

  18. LEADING INDICATORS OF REGIONAL COTTON ACREAGE RESPONSE: STRUCTURAL AND TIME SERIES MODELING RESULTS

    OpenAIRE

    Houston, Jack E.; McIntosh, Christopher S.; Stavriotis, Paul A.; Turner, Steven C.

    1999-01-01

    Resurgent cotton production compels better acreage forecasts for planning seed, chemical, and other input requirements. Structural models describe leading acreage response indicators, and forecasts are compared to time-series models. Cotton price, loan rate, deficiency payments, lagged corn acreage, the PIK program, and previous cotton yield significantly influence cotton acreage response.

  19. The impact of product configurators on lead times in engineering-oriented companies

    DEFF Research Database (Denmark)

    Haug, Anders; Hvam, Lars; Mortensen, Niels Henrik

    2011-01-01

    vague when reporting the effects of configurator projects. Only six cases were identified, which provide estimates of the actual size of lead time reduction achieved from product configurators. To broaden this knowledge, this paper presents the results of a study of 14 companies concerning the impact of...

  20. Production planning of a perishable product with lead time and non-stationary demand

    NARCIS (Netherlands)

    Pauls-Worm, K.G.J.; Haijema, R.; Hendrix, E.M.T.; Rossi, R.; Vorst, van der J.G.A.J.

    2012-01-01

    We study a production planning problem for a perishable product with a fixed lifetime, under a service-level constraint. The product has a non-stationary stochastic demand. Food supply chains of fresh products like cheese and several crop products, are characterised by long lead times due to maturat

  1. Integration of capacity, pricing, and lead-time decisions in a decentralized supply chain

    NARCIS (Netherlands)

    Zhu, Stuart X.

    2015-01-01

    We consider a decentralized supply chain consisting of a supplier and a retailer facing price- and lead-time-sensitive demand. The decision process is modelled by a Stackelberg game where the supplier, as a leader, determines the capacity and the wholesale price, and the retailer, as a follower, det

  2. A PROBABILISTIC INVENTORY MODEL FOR CONDITIONAL CREDIT PERIOD AND LEAD TIME WITH MULTIPLE STORAGE FACILITIES

    OpenAIRE

    S S Mishra; Himanshu Pandey; Singh, R. S.

    2008-01-01

    A probabilistic inventory model for conditional credit period with exponential demand, non-zero lead time and multiple storage facility has been developed. The behaviour of total expected cost (TEC) has been examined and the use and application of the model is demonstrated with the help of a numerical example.

  3. A PROBABILISTIC INVENTORY MODEL FOR CONDITIONAL CREDIT PERIOD AND LEAD TIME WITH MULTIPLE STORAGE FACILITIES

    Directory of Open Access Journals (Sweden)

    S. S. Mishra

    2008-01-01

    Full Text Available A probabilistic inventory model for conditional credit period with exponential demand, non-zero lead time and multiple storage facility has been developed. The behaviour of total expected cost (TEC has been examined and the use and application of the model is demonstrated with the help of a numerical example.

  4. Use of Six Sigma Methodology to Reduce Appointment Lead-Time in Obstetrics Outpatient Department.

    Science.gov (United States)

    Ortiz Barrios, Miguel A; Felizzola Jiménez, Heriberto

    2016-10-01

    This paper focuses on the issue of longer appointment lead-time in the obstetrics outpatient department of a maternal-child hospital in Colombia. Because of extended appointment lead-time, women with high-risk pregnancy could develop severe complications in their health status and put their babies at risk. This problem was detected through a project selection process explained in this article and to solve it, Six Sigma methodology has been used. First, the process was defined through a SIPOC diagram to identify its input and output variables. Second, six sigma performance indicators were calculated to establish the process baseline. Then, a fishbone diagram was used to determine the possible causes of the problem. These causes were validated with the aid of correlation analysis and other statistical tools. Later, improvement strategies were designed to reduce appointment lead-time in this department. Project results evidenced that average appointment lead-time reduced from 6,89 days to 4,08 days and the deviation standard dropped from 1,57 days to 1,24 days. In this way, the hospital will serve pregnant women faster, which represents a risk reduction of perinatal and maternal mortality. PMID:27580729

  5. Using geographic information systems to assess risk for elevated blood lead levels in children.

    OpenAIRE

    Roberts, James R.; Hulsey, Thomas C.; Curtis, Gerald B.; Reigart, J. Routt

    2003-01-01

    OBJECTIVES: Targeted screening for childhood lead poisoning depends on assessment of risk factors including housing age. Using a geographic information system (GIS), we aim to determine high-risk regions in Charleston County, South Carolina, to assist public health officials in developing targeted lead-screening. METHODS: Properties built before 1978 were geocoded (assigned latitude and longitude coordinates) from tax assessor data. Addresses of Charleston County children who have been screen...

  6. Collateral benefits and hidden hazards of soil arsenic during abatement assessment of residential lead hazards

    Energy Technology Data Exchange (ETDEWEB)

    Elless, M.P. [Edenspace Systems Corporation, 3810 Concorde Parkway, Suite 100, Dulles, VA 20151-1131 (United States)], E-mail: elless@edenspace.com; Ferguson, B.W. [Edenspace Systems Corporation, 3810 Concorde Parkway, Suite 100, Dulles, VA 20151-1131 (United States)], E-mail: ferguson@edenspace.com; Bray, C.A. [Edenspace Systems Corporation, 3810 Concorde Parkway, Suite 100, Dulles, VA 20151-1131 (United States)], E-mail: bray@edenspace.com; Patch, S. [Environmental Quality Institute, University of North Carolina, One University Heights, Asheville, NC 28804 (United States)], E-mail: patch@unca.edu; Mielke, H. [College of Pharmacy, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA 70125 (United States)], E-mail: hmielke@xula.edu; Blaylock, M.J. [Edenspace Systems Corporation, 3810 Concorde Parkway, Suite 100, Dulles, VA 20151-1131 (United States)], E-mail: blaylock@edenspace.com

    2008-11-15

    Abatement of soil-lead hazards may also reduce human exposure to other soil toxins, thereby achieving significant collateral benefits that are not accounted for today. This proposition was tested with the specific case of soil-arsenic, where 1726 residential soil samples were collected and analyzed for lead and arsenic. The study found that these two toxins coexisted in most samples, but their concentrations were weakly correlated, reflecting the differing sources for each toxin. Collateral benefits of 9% would be achieved during abatement of the lead-contaminated soils having elevated arsenic concentrations. However, a hidden hazard of 16% was observed by overlooking elevated arsenic concentrations in soils having lead concentrations not requiring abatement. This study recommends that soil samples collected under HUD programs should be collected from areas of lead and arsenic deposition and tested for arsenic as well as lead, and that soil abatement decisions consider soil-arsenic as well as soil-lead guidelines. - Coexistence of arsenic at elevated concentrations with lead in residential soils undergoing lead hazard assessment is often overlooked, providing either collateral benefits or hidden hazards.

  7. Collateral benefits and hidden hazards of soil arsenic during abatement assessment of residential lead hazards

    International Nuclear Information System (INIS)

    Abatement of soil-lead hazards may also reduce human exposure to other soil toxins, thereby achieving significant collateral benefits that are not accounted for today. This proposition was tested with the specific case of soil-arsenic, where 1726 residential soil samples were collected and analyzed for lead and arsenic. The study found that these two toxins coexisted in most samples, but their concentrations were weakly correlated, reflecting the differing sources for each toxin. Collateral benefits of 9% would be achieved during abatement of the lead-contaminated soils having elevated arsenic concentrations. However, a hidden hazard of 16% was observed by overlooking elevated arsenic concentrations in soils having lead concentrations not requiring abatement. This study recommends that soil samples collected under HUD programs should be collected from areas of lead and arsenic deposition and tested for arsenic as well as lead, and that soil abatement decisions consider soil-arsenic as well as soil-lead guidelines. - Coexistence of arsenic at elevated concentrations with lead in residential soils undergoing lead hazard assessment is often overlooked, providing either collateral benefits or hidden hazards

  8. An Integrated Multiechelon Logistics Model with Uncertain Delivery Lead Time and Quality Unreliability

    Directory of Open Access Journals (Sweden)

    Ming-Feng Yang

    2016-01-01

    Full Text Available Nowadays, in order to achieve advantages in supply chain management, how to keep inventory in adequate level and how to enhance customer service level are two critical practices for decision makers. Generally, uncertain lead time and defective products have much to do with inventory and service level. Therefore, this study mainly aims at developing a multiechelon integrated just-in-time inventory model with uncertain lead time and imperfect quality to enhance the benefits of the logistics model. In addition, the Ant Colony Algorithm (ACA is established to determine the optimal solutions. Moreover, based on our proposed model and analysis, the ACA is more efficient than Particle Swarm Optimization (PSO and Lingo in SMEIJI model. An example is provided in this study to illustrate how production run and defective rate have an effect on system costs. Finally, the results of our research could provide some managerial insights which support decision makers in real-world operations.

  9. Inventory Model (M,T) With Quadratic Backorder Costs And Continuous Lead Time Series 1

    OpenAIRE

    Dr. Martin Osawaru Omorodion

    2014-01-01

    We have assumed in this paper that demand follows a normal distribution, and lead times follow a gamma distribution and backorder costs is quadratic. The (M, T) Model an order is made to bring it to M at review time. The model is derived from the (nQ,R,T) model which at review time an integral multiple Q is ordered. After deriving the inventory costs for (nQ, R,T) we set Q 0 to obtain the (M,T) inventory costs by making use of the differentiation of the (nQ,R,T) model. The (M,T) inventory cos...

  10. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    OpenAIRE

    Jian-Qiang Luo; Hui Yang; Hua-Ming Song

    2011-01-01

    This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are form...

  11. Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    2008-01-01

    We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the 'extended lead time'. The derived performance measures...

  12. Human health and ecological risk assessment of soil-borne arsenic and lead: A site-specific risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Roy, M.; Epp, G.A.; Beukema, P. [Proctor and Redfern Ltd., Don Mills, Ontario (Canada); Nieboer, E. [McMaster Univ., Hamilton, Ontario (Canada)

    1997-12-31

    Screening level site specific human health and ecological risk assessments (ERA) were conducted at a historical (1908--1921) smelting and refining site in the Niagara Region, Ontario in accordance with the recently released provincial and federal risk assessment guidelines. The purpose of the assessment was to evaluate the risk associated with elevated levels of arsenic and lead in surface soils, and to assess alternative remediation options, prior to property transfer. Future intended land use will be parkland and for the site to remain forested. The identification of potential receptors, exposure pathways, and end-points was conducted at the biological community-level. The ERA involved a toxic cue inventory of the core smelting and refining site, adjacent lands and a reference site. Development of remediation options was based on hazard assessment and the prediction of risks associated with arsenic contamination. An evaluation of remediation options and the selection of a preferred option are discussed.

  13. Addressing and Assessing Lead Threats in Drinking Water: Non-Leaded Brass, Product Testing, Particulate Lead Occurrence and Effects of the Chloride to Sulfate Mass Ratio on Corrosion

    OpenAIRE

    Triantafyllidou, Simoni

    2006-01-01

    Growing concern over adverse health effects from low level lead exposure motivated reassessment of lead occurrence in drinking water, from the perspective of 1) possibly eliminating lead from new brass materials, and 2) performance testing of existing products. During the course of this thesis work, it was discovered that several cases of childhood lead poisoning in North Carolina, South Carolina and Washington D.C. occurred from contaminated potable water. That disconcerting finding prompt...

  14. Stochastic integrated vendor–buyer model with unstable lead time and setup cost

    Directory of Open Access Journals (Sweden)

    Chandra K. Jaggi

    2011-01-01

    Full Text Available This paper presents a new vendor-buyer system where there are different objectives for both sides. The proposed method of this paper is different from the other previously published works since it considers different objectives for both sides. In this paper, the vendor’s emphasis is on the crashing of the setup cost, which not only helps him compete in the market but also provides better services to his customers; and the buyer’s aim is to reduce the lead time, which not only facilitates the buyer to fulfill the customers’ demand on time but also enables him to earn a good reputation in the market or vice versa. In the light of the above stated facts, an integrated vendor-buyer stochastic inventory model is also developed. The propsed model considers two cases for demand during lead time: Case (i Complete demand information, Case (ii Partial demand information. The proposed model jointly optimizes the buyer’s ordered quantity and lead time along with vendor’s setup cost and the number of shipments. The results are demonstrated with the help of numerical examples.

  15. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    This paper provides the first comparative analysis of nuclear reactor construction costs in France and the United States. Studying the cost of nuclear power has often been a challenge, owing to the lack of reliable data sources and heterogeneity between countries, as well as the long time horizon which requires controlling for input prices and structural changes. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using expected demand variation as an instrument. We argue that benefits from nuclear reactor program standardization can arise through short term coordination gains, when the diversity of nuclear reactors' technologies under construction is low, or through long term benefits from learning spillovers from past reactor construction experience, if those spillovers are limited to similar reactors. We find that overnight construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect-Engineer (A- E). In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. (authors)

  16. PLANNED LEAD TIME OPTIMIZATION IN MATERIAL REQUIREMENT PLANNING ENVIRONMENT FOR MULTILEVEL PRODUCTION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Faicel HNAIEN; Alexandre DOLGUI; Mohamed-Aly OULD LOULY

    2008-01-01

    This paper deals with the problem of planned lead time calculation in a Material Requirement Planning (MRP) environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered: multi-level serial-production and assembly systems. For the serial production systems (one type of component at each level), a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and several numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.

  17. Assessment of Pulverised Fly Ash (PFA as an Ameliorant of Lead Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Edmond Gatima

    2005-01-01

    Full Text Available Fly Ash (FA is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases of furnace fired with coal or lignite at 1100 to 1400°C. About 95-99% of Fly Ash consists of oxides of Si, Al, Fe and Ca, about 0.5 to 3.5% consists of Na, P, K and S and the remainder is composed of trace elements. PFA has also been used as an adsorbing material when applied in treatment effluents. The use of Fly Ash as a chemical conditioner has previously been investigated with results indicating that Fly Ash does facilitate the filtering process since it decreases both specific resistance and capillary suction time. Therefore, the aim of this paper was to assess the potential of PFA as an ameliorant for soil artificially spiked with various Lead compounds (PbSO4, PbCO3, PbNO3 and PbS. Additions of quicklime and Fly Ash to the contaminated soils effectively reduced heavy metal leachability well below the regulatory limits for hazardous wastes. The results showed the effect of PFA on leaching of lead was significant for all the samples. A high interaction value depicting sampling effect over the use of the PFA as an ameliorant was observed. The order of the difference between samples treated with PFA and without PFA was PbNO3 > PbSO4 > PbCO3 > PbS (17 mg L-1 when compared to that of the control. The results also demonstrated that, effect of filtration and PFA as an ameliorant had a significant effect in reducing toxicity. However, it is important to consider the source of PFA, as certain sources could in essence impart certain toxic elements, defeating the primary purpose of amelioration.

  18. Using Diagnostic Assessment to Help Teachers Understand the Chemistry of the Lead-Acid Battery

    Science.gov (United States)

    Cheung, Derek

    2011-01-01

    Nineteen pre-service and in-service teachers taking a chemistry teaching methods course at a university in Hong Kong were asked to take a diagnostic assessment. It consisted of seven multiple-choice questions about the chemistry of the lead-acid battery. Analysis of the teachers' responses to the questions indicated that they had difficulty in…

  19. A proposed methodology for the assessment of arsenic, nickel, cadmium and lead levels in ambient air.

    Science.gov (United States)

    Santos, Germán; Fernández-Olmo, Ignacio

    2016-06-01

    Air quality assessment, required by the European Union (EU) Air Quality Directive, Directive 2008/50/EC, is part of the functions attributed to Environmental Management authorities. Based on the cost and time consumption associated with the experimental works required for the air quality assessment in relation to the EU-regulated metal and metalloids, other methods such as modelling or objective estimation arise as competitive alternatives when, in accordance with the Air Quality Directive, the levels of pollutants permit their use at a specific location. This work investigates the possibility of using statistical models based on Partial Least Squares Regression (PLSR) and Artificial Neural Networks (ANNs) to estimate the levels of arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb) in ambient air and their application for policy purposes. A methodology comprising the main steps that should be taken into consideration to prepare the input database, develop the model and evaluate their performance is proposed and applied to a case of study in Santander (Spain). It was observed that even though these approaches present some difficulties in estimating the individual sample concentrations, having an equivalent performance they can be considered valid for the estimation of the mean values - those to be compared with the limit/target values - fulfilling the uncertainty requirements in the context of the Air Quality Directive. Additionally, the influence of the consideration of input variables related to atmospheric stability on the performance of the studied statistical models has been determined. Although the consideration of these variables as additional inputs had no effect on As and Cd models, they did yield an improvement for Pb and Ni, especially with regard to ANN models. PMID:26950629

  20. Verification of short lead time forecast models: applied to Kp and Dst forecasting

    Science.gov (United States)

    Wintoft, Peter; Wik, Magnus

    2016-04-01

    In the ongoing EU/H2020 project PROGRESS models that predicts Kp, Dst, and AE from L1 solar wind data will be used as inputs to radiation belt models. The possible lead times from L1 measurements are shorter (10s of minutes to hours) than the typical duration of the physical phenomena that should be forecast. Under these circumstances several metrics fail to single out trivial cases, such as persistence. In this work we explore metrics and approaches for short lead time forecasts. We apply these to current Kp and Dst forecast models. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637302.

  1. Inventory policies analysis under demand patterns and lead times constraints in a real supply chain

    OpenAIRE

    De Sensi, Giuseppe; Longo, Francesco; Mirabelli, Giovanni

    2008-01-01

    Abstract This paper reports a study on a real three-echelon supply chain operating in the beverage sector. The authors, starting from the actual supply chain configuration, propose a detailed study of the inventory systems. The test of a comprehensive set of different operative scenarios, in terms of customers? demand intensity, customers? demand variability and lead times, becomes a powerful tool for inventory systems analysis along the supply chain. The main objective is the comp...

  2. Lead time variability management in pharmaceutical supply chains: Case Orion Oyj

    OpenAIRE

    Neva, Mikko

    2015-01-01

    This study examines process lead time variability management in a pharmaceutical supply chain environment. Motivation for the study stems from exceptional structure and regulation of pharmaceutical supply chains as well as current trends reforming the cornerstones of industry's business model. When the historical focus in pharmaceutical business has been in R&D and patent protection, this industry is today facing increasing requirements related to operational excellence development. One signi...

  3. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    This paper provides an econometric analysis of nuclear reactor construction costs in France and the United States based on overnight costs data. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using change in expected electricity demand as instrument. We argue that the construction of nuclear reactors can benefit from standardization gains through two channels. First, short term coordination benefits can arise when the diversity of nuclear reactors' designs under construction is low. Second, long term benefits can occur due to learning spillovers from past constructions of similar reactors. We find that construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect–Engineer. In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. -- Highlights: •This paper analyses the determinants of nuclear reactors construction costs and lead-time. •We study short term (coordination gains) and long term (learning by doing) benefits of standardization in France and the US. •Results show that standardization of nuclear programs is a key factor for reducing construction costs. •We also suggest that technological progress has contributed to construction costs escalation

  4. Waste and Lead Time Reduction in a Software Product Customization Process with Value Stream Maps

    OpenAIRE

    Mujtaba, Shahid; Feldt, Robert; Petersen, Kai

    2010-01-01

    Custom-developed adaptations of software products are increasingly important to meet different and changing customer needs and heterogeneous system environments. Efficient software customization processes with short lead times are thus a priority for companies to stay competitive. The purpose of this case study is to identify waste-related problems in a software product customization process by using value stream maps (VSM). The study was conducted at the telecom company Ericsson AB; the empi...

  5. One operational amplifier simulator for third order systems with a leading time constant

    Directory of Open Access Journals (Sweden)

    L. K. Wadhwa

    1963-01-01

    Full Text Available The paper outlines a method for the simulation of third order linear systems with only one operational amplifier. A particular class of the general third order systems, that is, systems with a leading time constant is considered in this paper. A basic circuit consisting of one operational amplifier, four capacitors and five resistors is presented. The circuit is a analyzed and the conditions of physical reliability discussed and obtained. The design formulae and procedure are also given.

  6. Dynamic Pricing and Lead-Time Quotation for a Multiclass Make-to-Order Queue

    OpenAIRE

    Sabri Çelik; Costis Maglaras

    2008-01-01

    This paper considers a profit-maximizing make-to-order manufacturer that offers multiple products to a market of price and delay sensitive users, using a model that captures three aspects of particular interest: first, the joint use of dynamic pricing and lead-time quotation controls to manage demand; second, the presence of a dual sourcing mode that can expedite orders at a cost; and third, the interaction of the aforementioned demand controls with the operational decisions of sequencing and...

  7. Contract Assembly: Dealing with Combined Supply Lead Time and Demand Quantity Uncertainty

    OpenAIRE

    Jing-Sheng Song; Candace A. Yano; Panupol Lerssrisuriya

    2000-01-01

    We consider a problem faced by a contract assembler that both assembles finished goods and procures the associated component parts for one of its major customers. Because of rapid changes in technology and ongoing engineering changes, all parts subject to obsolescence are purchased only for the current customer order. The procurement lead times of the components are random. Moreover, although the order for the finished product has a defined due date, the contract allows the customer to change...

  8. Periodic review base-stock replenishment policy with endogenous lead times

    OpenAIRE

    Boute, Robert; Lambrecht, Marc; Van Houdt, B

    2004-01-01

    In this paper, we consider a two stage supply chain where the retailer's inventory is controlled by the periodic review, base-stock level (R,S) replenishment policy and the replenishment lead times are endogenously generated by the manufacturer's production system with finite capacity. We extend the work of Benjaafar and Kim (2004) who study the effect of demand variability in a continuously reviewed base-stock policy with single unit demands. In our analysis, we allow for demand in batches o...

  9. Safety stock or safety lead time: coping with unreliability in demand and supply

    OpenAIRE

    Van Kampen, Tim J.; Donk, Dirk Pieter van; van der Zee, Durk-Jouke

    2010-01-01

    Abstract Safety stock and safety lead time are common measures used to cope with uncertainties in demand and supply. Typically, these uncertainties are studied in isolated instances, ignoring settings with uncertainties both in demand and in supply. The current literature largely neglects case study based contexts and, often, single product situations are investigated in which machine set-ups are not considered. Based on the problems and findings in a case study, we investigate the...

  10. Lead Paint Exposure Assessment in High Bays of Johnson Space Center

    Science.gov (United States)

    Stanch, Penney; Plaza, Angel; Keprta, Sean

    2008-01-01

    This slide presentation reviews the program to assess the possibility of lead paint exposure in the high bays of some of the Johnson Space Center buildings. Some of the buildings in the Manned Space Flight Center (MSC) were built in 1962 and predate any considerations to reduce lead in paints and coatings. There are many of these older buildings that contain open shops and work areas that have open ceilings, These shops include those that had operations that use leaded gasoline, batteries, and lead based paints. Test were planned to be conducted in three phases: (1) Surface Dust sampling, (2) personal exposure montioring, and (3) Ceiling paint Sampling. The results of the first two phases were reviewed. After considering the results of the first two phases, and the problems associated with the retrieval of samples from high ceilings, it was determined that the evaluation of ceiling coatings would be done on a project by project and in response to a complaint.

  11. Strategic Inventory Positioning in BOM with Multiple Parents Using ASR Lead Time

    Directory of Open Access Journals (Sweden)

    Jingjing Jiang

    2016-01-01

    Full Text Available In order to meet the lead time that the customers require, work-in-process inventory (WIPI is necessary at almost every station in most make-to-order manufacturing. Depending on the station network configuration and lead time at each station, some of the WIPI do not contribute to reducing the manufacturing lead time of the final product at all. Therefore, it is important to identify the optimal set of stations to hold WIPI such that the total inventory holding cost is minimized, while the required due date for the final product is met. The authors have presented a model to determine the optimal position and quantity of WIPI for a given simple bill of material (S-BOM, in which any part in the BOM has only one immediate parent node. In this paper, we extend the previous study to the general BOM (G-BOM in which parts in the BOM can have more than one immediate parent and present a new solution procedure using genetic algorithm.

  12. Optimal Decision for Fashion Supply Chains with Service Level Constraint and Controllable Lead Time

    Directory of Open Access Journals (Sweden)

    Guo Li

    2015-01-01

    Full Text Available We study a two-echelon supply chain inventory model with controllable lead time and service level constraint in fashion supply chains, in which we assume that the unit cost of compressing lead time follows exponential distribution. Under these conditions we investigate the optimal ordering quantity and production quantity in the fashion supply chain by minimizing the joint total cost. Simultaneously, we work out the boundaries of ordering quantity and production quantity, which simplify the computation. Furthermore, numerical examples are presented to test the feasibility of the model. The results show that assuming the unit cost of compressing lead time in accordance with exponential distribution is realistic. It also notices that the optimal order and production decision for fashion supply chains are constrained obviously by the service level and safety factors. What is more, the holding cost rate of both the service level and safety factors has a certain influence on it. And by further analyzing on some references in the last part, we have done some extensions and found some interesting results.

  13. Integrated supply chain inventory model with quality improvement involving controllable lead time and backorder price discount

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-06-01

    Full Text Available For the past four decades the integrated vendor and buyer supply chain inventory model has been an interesting topic, but quality improvement of defective items in the integrated inventory model with backorder price discount involving controllable lead time has been rarely discussed. The aim of this paper is to minimize the total related cost in the continuous review model by considering the order quantity, reorder point, lead time, process quality, backorder price discount and number of shipment as decision variables. Moreover, we assume that an investment function is used to improve the process quality. The lead time demand follows a normal distribution. In addition, the buyer offers backorder price discount to motivate the customers for possible backorders. There are some defective items in the arrival lot, so its treatment is also taken in account in this paper. We develop an iterative procedure for finding the optimal values of decision variables and numerical example is presented to illustrate the solution procedure. Additionally, sensitivity analysis with respect to major parameters is also carried out.

  14. Enhancing Nursing Staffing Forecasting With Safety Stock Over Lead Time Modeling.

    Science.gov (United States)

    McNair, Douglas S

    2015-01-01

    In balancing competing priorities, it is essential that nursing staffing provide enough nurses to safely and effectively care for the patients. Mathematical models to predict optimal "safety stocks" have been routine in supply chain management for many years but have up to now not been applied in nursing workforce management. There are various aspects that exhibit similarities between the 2 disciplines, such as an evolving demand forecast according to acuity and the fact that provisioning "stock" to meet demand in a future period has nonzero variable lead time. Under assumptions about the forecasts (eg, the demand process is well fit as an autoregressive process) and about the labor supply process (≥1 shifts' lead time), we show that safety stock over lead time for such systems is effectively equivalent to the corresponding well-studied problem for systems with stationary demand bounds and base stock policies. Hence, we can apply existing models from supply chain analytics to find the optimal safety levels of nurse staffing. We use a case study with real data to demonstrate that there are significant benefits from the inclusion of the forecast process when determining the optimal safety stocks. PMID:26340239

  15. The M/M/1 queue with inventory, lost sale and general lead times

    DEFF Research Database (Denmark)

    Saffari, Mohammad; Asmussen, Søren; Haji, Rasoul

    queue length (number of customers in the system) and on-hand inventory when lead times are random variables and can take various distributions. The derived stationary distributions are used to formulate long-run average performance measures and cost functions in some numerical examples.......We consider an M/M/1 queueing system with inventory under the (r,Q) policy and with lost sales, in which demands occur according to a Poisson process and service times are exponentially distributed. All arriving customers during stockout are lost. We derive the stationary distributions of the joint...

  16. Leading effective virtual teams overcoming time and distance to achieve exceptional results

    CERN Document Server

    Settle-Murphy, Nancy M

    2013-01-01

    A proliferation of new technologies has lulled many into thinking that we actually have to think less about how we communicate. In fact, communicating and collaborating across time, distance, and cultures has never been more complex or difficult.Written as a series of bulleted tips drawn from client experiences and best practices, Leading Effective Virtual Teams: Overcoming Time and Distance to Achieve Exceptional Results presents practical tips to help leaders engage and motivate their geographically dispersed project team members. If you're a leader of any type of virtual team and want to he

  17. Analog filtering methods improve leading edge timing performance of multiplexed SiPMs.

    Science.gov (United States)

    Bieniosek, M F; Cates, J W; Grant, A M; Levin, C S

    2016-08-21

    Multiplexing many SiPMs to a single readout channel is an attractive option to reduce the readout complexity of high performance time of flight (TOF) PET systems. However, the additional dark counts and shaping from each SiPM cause significant baseline fluctuations in the output waveform, degrading timing measurements using a leading edge threshold. This work proposes the use of a simple analog filtering network to reduce the baseline fluctuations in highly multiplexed SiPM readouts. With 16 SiPMs multiplexed, the FWHM coincident timing resolution for single [Formula: see text] mm LYSO crystals was improved from 401  ±  4 ps without filtering to 248  ±  5 ps with filtering. With 4 SiPMs multiplexed, using an array of [Formula: see text] mm LFS crystals the mean time resolution was improved from 436  ±  6 ps to 249  ±  2 ps. Position information was acquired with a novel binary positioning network. All experiments were performed at room temperature with no active temperature regulation. These results show a promising technique for the construction of high performance multiplexed TOF PET readout systems using analog leading edge timing pickoff. PMID:27484131

  18. Analog filtering methods improve leading edge timing performance of multiplexed SiPMs

    Science.gov (United States)

    Bieniosek, M. F.; Cates, J. W.; Grant, A. M.; Levin, C. S.

    2016-08-01

    Multiplexing many SiPMs to a single readout channel is an attractive option to reduce the readout complexity of high performance time of flight (TOF) PET systems. However, the additional dark counts and shaping from each SiPM cause significant baseline fluctuations in the output waveform, degrading timing measurements using a leading edge threshold. This work proposes the use of a simple analog filtering network to reduce the baseline fluctuations in highly multiplexed SiPM readouts. With 16 SiPMs multiplexed, the FWHM coincident timing resolution for single 3~\\text{mm}× 3~\\text{mm}× 20 mm LYSO crystals was improved from 401  ±  4 ps without filtering to 248  ±  5 ps with filtering. With 4 SiPMs multiplexed, using an array of 3~\\text{mm}× 3~\\text{mm}× 20 mm LFS crystals the mean time resolution was improved from 436  ±  6 ps to 249  ±  2 ps. Position information was acquired with a novel binary positioning network. All experiments were performed at room temperature with no active temperature regulation. These results show a promising technique for the construction of high performance multiplexed TOF PET readout systems using analog leading edge timing pickoff.

  19. Average pulse shape model for leading edge timing with Ge(Li) coaxial detector

    International Nuclear Information System (INIS)

    A model is presented for prompt time-response from leading-edge triggering, where calculations are rendered simpler for uniform γ-irradiation of coaxial Ge(Li) detector. Pulse shapes are formed at the timing filter amplifier output, from direct detector pulse. Average pulse-shape method is found responsible for some sort of walk compensation and by drawing time-resolution vs triggering fraction, one can predict the best FWHM with detector of RC-filtered signal. It also shows the effect of mixed filter time-constant on r.m.s. noise. Taking account of both statistical and noise effects on FWHM, the statistical contribution increases to 7% at 3 MeV of the detected energy

  20. Effect of sintering and milling time on lead magnesium niobate nanocrystallite phase

    International Nuclear Information System (INIS)

    Lead magnesium niobate, Pb (Mg1/3Nb2/3)O3 (PMN) nanocrystallite was produced using the solid-state reaction method. The effect of sintering and milling time on the formation of the perovskite phase of Pb (Mg1/3Nb2/3)O3 was investigated. For a given calcinations and sintering temperature, more perovskite phase and less impurities were detected by X-ray diffraction (XRD) in samples milled for different times compared to the samples without milling. The perovskite phase is seen to increase when the sintered temperature is increased; suggesting the heat energy required for the perovskite phase is less in these samples compared to the sample sintered for low temperature. Also the perovskite phase increase with the increasing of sintering time up to 6 h and then decrease. The perovskite phase increased with increased milling time

  1. Assessment of peripheral neuropathy in male hospitalized patients with lead toxicity in Iran

    Directory of Open Access Journals (Sweden)

    Khosro Sadeghniiat-Haghighi

    2013-01-01

    Full Text Available Background: This study assessed the effect of lead exposure on the peripheral nervous system in 40 hospitalized patients with lead toxicity [blood lead level (BLL >70 μg/dl] and compared their electrodiagnostic indices with the results of the control group. Materials and Methods: We assessed signs and symptoms of neuropathy in patients and conducted nerve conduction velocity (NCV in patients and control groups, then compared the results between the two groups. Results: Average duration of exposure to lead was 10.85 years. The mean BLL of patients was 100.32 μg/dl (SD = 18.42. The most common symptoms in patients were mood and sleep disturbance (64.1% and paresthesia (47.5%. Among the patients, all of the NCV indices in median, ulnar, and radial nerves were normal. On comparing the average indices of NCV in lead-exposed men with controls, significant reductions were noted in most of the indices and with prolonged distal motor latency and peak latency. Significant but weak correlations were found between BLL and some of the indices (P value < 0.05, r = 0.33-0.52. Conclusion: Comparing electrophysiological study indicators between case vs controls and considering the symptoms of patients, our study showed that patient may progress to sensory neuropathy.

  2. Optimal base-stock policy for the inventory system with periodic review, backorders and sequantial lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    2008-01-01

    We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the ‘extended lead time’. The derived performance measures are...... exact for Poisson demands....

  3. Assessment of Genotoxicity through ISSR Marker in Pistia stratiotes Induced by Lead

    OpenAIRE

    Lamyai Neeratanaphan; Runglawan Sudmoon; Arunrat Chaveerach

    2014-01-01

    Assessment of DNA changes in Pistia stratiotes induced by lead (Pb), plants were grown in acclimatized conditions for 15 days. Each of 5 plants were then transferred to cultivate in three repeated 0.2, 0.3, 0.5 mg/l Pb experiments, four days and controls. Lead concentration in water was analyzed by inductively-coupled plasma - mass spectrometry (ICP-MS), physical and chemical factors including temperature, pH, dissolved oxygen (DO) and electro-conductivity (EC) before and after the experiment...

  4. Turbulent time scales and the temperature variance dissipation rate in natural convection in lead-bismuth

    International Nuclear Information System (INIS)

    Turbulent heat transfer is of basic interest for the development and analysis of the lead-bismuth cooled accelerator-driven nuclear reactor concept. Results of a direct numerical simulation (DNS) for Rayleigh-Benard convection for the Rayleigh number Ra = 105 in a fluid with the Prandtl number Pr = 0,025, which corresponds to liquid lead-bismuth, are used to analyze turbulent time scales and the temperature variance dissipation rate. These results indicate that an application of the thermal or mixed time scale may considerably improve the standard heat flux model at this Rayleigh- and Prandtl numbers. Standard temperature variance dissipation rate model is investigated using the DNS results for Rayleigh-Benard convection at Pr equals 0,025, Ra equals 105. The analysis of the standard temperature variance dissipation rate model shows the importance of wall functions and the qualitatively good predictions by the standard model for this type of flow. Quantitatively this model over-predicts the results of direct numerical simulation by about 25%. The two-point correlation method is used to model the temperature variance dissipation rate. Comparison with DNS results shows qualitatively and quantitatively good predictions of the new model. The new temperature variance dissipation rate model leads therefore to an increased accuracy of turbulent heat flux models for this type of flow. An additional advantage is a minimal increase in model complexity which makes no special demands on model implementation into computer codes

  5. Environmental health risk assessment of ambient lead levels in Lisbon, Portugal: A full chain study approach

    DEFF Research Database (Denmark)

    Casimiro, E.; Philippe Ciffroy, P.; Serpa, P.;

    2011-01-01

    useful for integrated full-chain human health risk assessments. In this study we use a newly developed computational tool – the 2FUN player to conduct a full-chain assessment combining measured ambient air lead concentrations with multi-media modelling and PBPK simulations to estimate the health risks...... calculate the Pb levels in the various body systems. Our results showed a low health risk from Pb exposures. It also identified that ingestion of leafy vegetables (i.e. lettuce, cabbage, and spinach) and fruits contribute the most to total Pb blood levels. This full chain assessment approach of the 2FUN...... player is likely to be very useful for local health risk assessment studies (i.e. EIA and SEA studies)....

  6. Stability Region Analysis of PID and Series Leading Correction PID Controllers for the Time Delay Systems

    Directory of Open Access Journals (Sweden)

    D. RAMA REDDY

    2012-07-01

    Full Text Available This paper describes the stability regions of PID (Proportional +Integral+ Derivative and a new PID with series leading correction (SLC for Networked control system with time delay. The new PID controller has a tuning parameter ‘β’. The relation between β, KP, KI and KD is derived. The effect of plant parameters on stabilityregion of PID controllers and SLC-PID controllers in first-order and second-order systems with time delay are also studied. Finally, an open-loop zero was inserted into the plant-unstable second order system with time delay so that the stability regions of PID and SLC-PID controllers get effectively enlarged. The total system isimplemented using MATLAB/Simulink.

  7. A new order splitting model with stochastic lead times for deterioration items

    Science.gov (United States)

    Sazvar, Zeinab; Akbari Jokar, Mohammad Reza; Baboli, Armand

    2014-09-01

    In unreliable supply environments, the strategy of pooling lead time risks by splitting replenishment orders among multiple suppliers simultaneously is an attractive sourcing policy that has captured the attention of academic researchers and corporate managers alike. While various assumptions are considered in the models developed, researchers tend to overlook an important inventory category in order splitting models: deteriorating items. In this paper, we study an order splitting policy for a retailer that sells a deteriorating product. The inventory system is modelled as a continuous review system (s, Q) under stochastic lead time. Demand rate per unit time is assumed to be constant over an infinite planning horizon and shortages are backordered completely. We develop two inventory models. In the first model, it is assumed that all the requirements are supplied by only one source, whereas in the second, two suppliers are available. We use sensitivity analysis to determine the situations in which each sourcing policy is the most economic. We then study a real case from the European pharmaceutical industry to demonstrate the applicability and effectiveness of the proposed models. Finally, more promising directions are suggested for future research.

  8. An exposure and health risk assessment of lead (Pb) in lipstick.

    Science.gov (United States)

    Monnot, Andrew D; Christian, Whitney V; Abramson, Matthew M; Follansbee, Mark H

    2015-06-01

    Lead (Pb) content in lipstick and other consumer products has become an increasing concern. In 2010, the United States Food and Drug Administration tested 400 lipstick samples and found a maximum Pb concentration of 7.19 ppm. To assess the safety of lipstick in adults that chronically apply lipstick as well as instances where children might incidentally ingest lipstick products, the United States Environmental Protection Agency's (US EPA) Adult Lead Model and Integrated Exposure Uptake Biokinetic Model for Lead in Children were used to determine the blood Pb concentrations of adults and children ingesting varying amounts of lipstick of different Pb concentrations. Modeled blood Pb concentrations were compared with oral ingestion guidelines and to the Centers for Disease Control and the US EPA's actionable blood Pb levels of 5 and 10 µg/dL. Background Pb exposure was the primary contributor to estimated blood Pb levels (BLLs) in children and adults, and Pb exposure from lipstick did not significantly increase estimated BLLs. These results suggest that the safety of consumer products and cosmetics should be assessed not only by the presence and amounts of hazardous contents, but also in conjunction with an assessment of estimated background exposures and comparison to health-based standards. PMID:25839902

  9. Developing a Flexible Lead Time Model for the Order-to-Delivery Process

    OpenAIRE

    Pökkä, Jaakko

    2014-01-01

    This Thesis focuses on the improvement of the order-to-delivery process. The business problem of this study is the need for more agility and flexibility to handle the order-to-delivery process in the case company. Intense competition and tight situation in the economics have led to a situation where the lead times are one of the key factors to win or lose the competition. To address this challenge, the objective of this Thesis is to develop a new flexible process model in order improve the ef...

  10. Dynamic Re-order Point Inventory Control with Lead-Time Uncertainty: Analysis and Empirical Investigation

    OpenAIRE

    Babai, Mohamed Zied; Syntetos, Aris A; Dallery, Yves; Nikolopoulos, Kostantinos

    2009-01-01

    Abstract A new forecast-based dynamic inventory control approach is discussed in this paper. In this approach, forecasts and forecast uncertainties are assumed to be exogenous data known in advance at each period over a fixed horizon. The control parameters are derived by using a sequential procedure. The merits of this approach as compared to the classical one are presented. We focus on a single-stage and single-item inventory system with non-stationary demand and lead-time uncert...

  11. PRODUCTION INVENTORY SYSTEM WITH RANDOM SUPPLY INTERRUPTIONS STATUE AND RANDOM LEAD TIMES

    Institute of Scientific and Technical Information of China (English)

    Hou Yumei; Liu Wenyuan; Zhang Qiang; Wu Fengqing

    2011-01-01

    This article analyzes a continuous-review inventory system with random supply interruptions and random lead time which may be interrupted by a random number of supplier's OFF periods. The inventory with constant demand rate is managed by a (r; q1, q2,..., qm) policy and supplies from an unreliable sole supplier. By renewal theory and matrix Geometric method, the long-run average cost function is obtained and some important properties of the function are proved. Furthermore, performance of the inventory is derived.

  12. A Dynamic Inventory Control Policy Under Demand, Yield and Lead Time Uncertainties

    OpenAIRE

    Babai, Z.; Dallery, Yves

    2006-01-01

    In this paper, we analyze a single-stage and single-item inventory control system with non-stationary demand and uncertain system parameters. We propose two extensions of a previous work on the dynamic reorder point policy (the (rk;Q) policy [2]). In the first extension, we include three types of uncertainties pertaining to the demand uncertainty, the lead time uncertainty, and the yield uncertainty. We study the impact of these uncertainties on the (rk;Q) policy and we provide an approximati...

  13. Stochastic integrated vendor–buyer model with unstable lead time and setup cost

    OpenAIRE

    Jaggi, Chandra K.; Neetu Arneja

    2011-01-01

    This paper presents a new vendor-buyer system where there are different objectives for both sides. The proposed method of this paper is different from the other previously published works since it considers different objectives for both sides. In this paper, the vendor’s emphasis is on the crashing of the setup cost, which not only helps him compete in the market but also provides better services to his customers; and the buyer’s aim is to reduce the lead time, which not only facilitates the ...

  14. The Composite Index of Leading Economic Indicators: How to Make it More Timely

    OpenAIRE

    McGuckin, Robert H.; Ataman Ozyildirim; Victor Zarnowitz

    2000-01-01

    A major shortcoming of the U.S. leading index is that it does not use the most recent information for stock prices and yield spreads. The index methodology ignores these data in favor of a time-consistent set of components (i.e., all of the components must refer to the previous month). An alternative is to bring the series with publication lags up-to-date with forecasts and create an index with a complete set of most recent components. This study uses tests of ex-ante predictive ability of th...

  15. Lead detection in Arctic sea ice from CryoSat-2: quality assessment, lead area fraction and width distribution

    Directory of Open Access Journals (Sweden)

    A. Wernecke

    2015-03-01

    Full Text Available Leads cover only a small fraction of the Arctic sea ice but they have a dominant effect on the turbulent exchange between the ocean and the atmosphere. A supervised classification of CryoSat-2 measurements is performed by a combination with visual MODIS scenes. For several parameters thresholds are optimized and tested in order to reproduce this prior classification. The maximum power of the waveform shows the best classification properties amongst them, including the Pulse Peakiness. With the same correct lead detection rates as of published classifiers, the amount of ice being detected as lead can be reduced by up to 40%. Lead area fraction estimates based on CryoSat-2 show a major fracturing event in the Beaufort Sea in 2013. The resulting Arctic wide lead width distribution follows a power law with an exponent of 2.47 ± 0.04 for the winter seasons from 2011 to 2014, confirming and complementing a regional study based on a high resolution SPOT image.

  16. Investigation of Suitability of Cascading Outage Assessment Methods for Real-Time Assessment

    DEFF Research Database (Denmark)

    Petersen, Pauli Fríðheim; Jóhannsson, Hjörtur; Nielsen, Arne Hejde

    This paper investigates the suitability of assessment methods for cascading outages for real-time assessment. A total of ten assessment methods for cascading outages are investigated, and for all of the investigated methods a complexity assessment is performed to assess the suitability...... of the method to real-time assessment. The investigation revealed that two of the methods are of special interest for further study on real-time assessment of cascading outages. These are the betweenness centrality model, based on network topology, and the manchester model, based on AC power flow....

  17. Modeling and analysis for determining optimal suppliers under stochastic lead times

    DEFF Research Database (Denmark)

    Abginehchi, Soheil; Farahani, Reza Zanjirani

    2010-01-01

    The policy of simultaneously splitting replenishment orders among several suppliers has received considerable attention in the last few years and continues to attract the attention of researchers. In this paper, we develop a mathematical model which considers multiple-supplier single-item inventory...... systems. The item acquisition lead times of suppliers are random variables. Backorder is allowed and shortage cost is charged based on not only per unit in shortage but also per time unit. Continuous review (s,Q) policy has been assumed. When the inventory level depletes to a reorder level, the total......, procurement cost, inventory holding cost, and shortage cost, is minimized. We also conduct extensive numerical experiments to show the advantages of our model compared with the models in the literature. According to our extensive experiments, the model developed in this paper is the best model in the...

  18. Examining Progress across Time with Practical Assessments in Ensemble Settings

    Science.gov (United States)

    Crochet, Lorrie S.; Green, Susan K.

    2012-01-01

    This article provides the rationale for effective music assessment that tracks individual progress across time and offers examples to illustrate assessment of a range of music-learning goals. Gauging progress across time helps students become more mastery-oriented, while showing more effort and positive attitudes. As instruction and assessment…

  19. Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Randich, E; Grant, P M

    2006-08-29

    The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano, 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in Mannlicher-Carcano bullet lead, and the 5-60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.

  20. BACKORDER AND LOST SALES CONTINUOUS REVIEW RAW MATERIAL INVENTORY CONTROL SYSTEM WITH LEAD TIME AND ORDERING COST REDUCTION

    OpenAIRE

    Tiena Gustina Amran; Dinar Suryo Lesmono

    2012-01-01

    The purpose of this research is to suggest the optimal raw material inventory system alternatives synchronized with the stock out characteristics and the condition can be occurred, the backorder raw material inventory control, beside that it also can reduce lead time and raw material ordering cost. In this case, the inventory models also extent (Q, R) Inventory Model Under lead Time and Ordering Cost Reduction with lead time and ordering cost can be reduced. After the calculation, the optimal...

  1. Benzene and lead exposure assessment among occupational bus drivers in Bangkok traffic

    Institute of Scientific and Technical Information of China (English)

    SHING TET LEONG; PREECHA LAORTANAKUL

    2004-01-01

    Four environmental and biological monitoring sites were strategically established to evaluate benzene and lead exposure assessment at various traffic zones of Bangkok Metropolitan Region(BMR). Biological measurement of 48 non air-conditioned, male bus drivers was carried to study the relationship between individual exposure levels and exposure biomarkers. The study group was further subdivided into four age groups( 16-25, 26-35, 36-45 and 46-55 years old) to monitor the age-related exposure effects. A total of 12unexposed persons were deliberately chosen as the control group. Measurement of unmetobolized benzene in blood and analysis of urinary tt-Muconic acid urine and urinary creatinine are recommended as biomarkers of benzene exposure. Measurement of lead in blood and urine is also recommended for the biological monitoring of lead exposure.During the monitoring period, benzene and lead levels at Yaowarat Road was C6H6: 42.46 + 3.88 μg/m3 , Pb: 0.29 + 0.03 μg/m3 and decreased to C6 H6: 33.5 ± 1.35 μg/m3 , Pb: O. 13 + 0.01 μg/m3 at Phahonyothin Road. Significant difference was established between the nonsmoking exposed group and nonsmoking control group for blood benzene concentrations ( P < 0.001, two-tailed, Mann-Whiteney U test). Strong correlations were also found between trans-trans-Muconic acid concentrations in post shift samples and atmospheric benzene concentrations. Similarly, good correlation between all of biomarkers and lead level in air is established from automobile emissions.The analysis revealed that among the occupational population in the urban sites, the driver groups were found to have the highest risk of benzene and lead exposures derived from automobile emission.

  2. Benzene and lead exposure assessment among occupational bus drivers in Bangkok traffic.

    Science.gov (United States)

    Muttamara, S; Leong, Shing Tet; Arayasiri, M

    2004-01-01

    Four environmental and biological monitoring sites were strategically established to evaluate benzene and lead exposure assessment at various traffic zones of Bangkok Metropolitan Region(BMR). Biological measurement of 48 non air-conditioned, male bus drivers was carried to study the relationship between individual exposure levels and exposure biomarkers. The study group was further subdivided into four age groups(16-25, 26-35, 36-45 and 46-55 years old) to monitor the age-related exposure effects. A total of 12 unexposed persons were deliberately chosen as the control group. Measurement of unmetobolized benzene in blood and analysis of urinary tt-Muconic acid urine and urinary creatinine are recommended as biomarkers of benzene exposure. Measurement of lead in blood and urine is also recommended for the biological monitoring of lead exposure. During the monitoring period, benzene and lead levels at Yaowarat Road was C6H6: 42.46 +/- 3.88 microg/m3 , Pb: 0.29 +/- 0.03 microg/m3 and decreased to C6H6: 33.5 +/- 1.35 microg/m3, Pb: 0.13 +/- 0.01 microg/m3 at Phahonyothin Road. Significant difference was established between the nonsmoking exposed group and nonsmoking control group for blood benzene concentrations (P < 0.001, two-tailed, Mann-Whiteney U test). Strong correlations were also found between trans-trans-Muconic acid concentrations in post shift samples and atmospheric benzene concentrations. Similarly, good correlation between all of biomarkers and lead level in air is established from automobile emissions. The analysis revealed that among the occupational population in the urban sites, the driver groups were found to have the highest risk of benzene and lead exposures derived from automobile emission. PMID:14971454

  3. Assessment of the Efficacy of Chelate-Assisted Phytoextraction of Lead by Coffeeweed (Sesbania exaltata Raf.

    Directory of Open Access Journals (Sweden)

    Gloria Miller

    2008-12-01

    Full Text Available Lead (Pb, depending upon the reactant surface, pH, redox potential and other factors can bind tightly to the soil with a retention time of many centuries. Soil-metal interactions by sorption, precipitation and complexation processes, and differences between plant species in metal uptake efficiency, transport, and susceptibility make a general prediction of soil metal bioavailability and risks of plant metal toxicity difficult. Moreover, the tight binding characteristic of Pb to soils and plant materials make a significant portion of Pb unavailable for uptake by plants. This experiment was conducted to determine whether the addition of ethylenediaminetetraacetic acid (EDTA, ethylene glycol tetraacetic acid (EGTA, or acetic acid (HAc can enhance the phytoextraction of Pb by making the Pb soluble and more bioavailable for uptake by coffeeweed (Sesbania exaltata Raf.. Also we wanted to assess the efficacy of chelates in facilitating translocation of the metal into the above-ground biomass of this plant. To test the effect of chelates on Pb solubility, 2 g of Pb-spiked soil (1000 mg Pb/kg dry soil were added to each 15 mL centrifuge tube. Chelates (EDTA, EGTA, HAc in a 1:1 ratio with the metal, or distilled deionized water were then added. Samples were shaken on a platform shaker then centrifuged at the end of several time periods. Supernatants were filtered with a 0.45 μm filter and quantified by inductively coupled plasma-optical emission spectrometry (ICP-OES to determine soluble Pb concentrations. Results revealed that EDTA was the most effective in bringing Pb into solution, and that maximum solubility was reached 6 days after chelate amendment. Additionally, a greenhouse experiment was conducted by planting Sesbania seeds in plastic tubes containing top soil and peat (2:1, v:v spiked with various levels (0, 1000, 2000 mg Pb/kg dry soil of lead nitrate. At six weeks after emergence, aqueous solutions of EDTA and/or HAc (in a 1:1 ratio

  4. Pre-Implant Assessment for Optimal LV Lead Placement in CRT: ECG, Echo, or MRI?

    Directory of Open Access Journals (Sweden)

    Matthew J. Singleton; David D. Spragg.

    2015-08-01

    Full Text Available ABSTRACT Cardiac resynchronization therapy (CRT improves cardiac function in many patients with ventricular dyssynchrony. The optimal use of imaging for pre-implantation assessment remains a subject of debate. Here, we review the literature to date on the utility of echocardiography and cardiac MR, as well as conventional ECG, in choosing the best site for LV lead implantation. Prior to the use of imaging for pre-implantation evaluation, LV leads were placed empirically, based on average responses from population-level studies. Subsequently, patient-specific approaches have been used to maximize response. Both echocardiography and cardiac MR allow determination of areas of latest mechanical activation. Some studies have found improved response when pacing is applied at or near the site of latest mechanical activation. Similarly, both echocardiography and cardiac MR provide information about the location of any myocardial scar, which should be avoided when placing the LV lead due to variable conduction and high capture thresholds. Alternative approaches include targeting the region of latest electrical activation via measurement of the QLV interval and methods based on intraoperative hemodynamic measurements. Each of these modalities offers complementary insights into LV lead placement, so future directions include multimodality pre-implantation evaluation, studies of which are ongoing. Emerging technologies such as leadless implantable pacemakers may free implanting electrophysiologists from the constraints of the coronary sinus, making this information more useful and making non-response to CRT increasingly rare.

  5. Neutron CT with a multi-detector system leading to drastical reduction of the measuring time

    International Nuclear Information System (INIS)

    By means of numerical simulation methods and their verification with measurements it could be shown that such a detector system can be realized for a line beam and 1-2 detectors per cm. With the maximum available beam width of the fast neutron field at the FRM approximately 20 detectors can be used leading to a reduction of the measuring time to 0,5 - 1 hour. A multi detector system for a line beam of thermal neutrons was constructed, tested and used for CT-measurements. This detector system for the measurement of thinner layers with better spatial resolution could be realized. The electronic discrimination between neutrons and gamma rays has been improved. This discrimination was used in all CT-measurements to get transmission values of both kinds of radiation and to reconstruct to complementary CT-images. The use of a polyenergetic radiation causes spectral shifts in the transmission spectrum leading to artifacts in the reconstructed CT-image. The transmission values must be spectral corrected before image reconstruction, because the image artifacts complicate the image evaluation or make it impossible. A new energy selective procedure for the online spectral correction was developed. This method is based on the concept to measure additionally to the integral transmission value his pulse height spectrum and to do the correction depending on the changes in this pulse height spectrum. (orig./HP)

  6. Random Lead Time of the acute ghrelin response to a psychological stress

    Directory of Open Access Journals (Sweden)

    Geetha.T

    2014-12-01

    Full Text Available Ghrelin is a growth hormone and cortisol secretagogue that plays an important role in appetite and weight regulation. It is not known whether ghrelin is involved in the eating response to stress in humans. In the present study we examined the effects of psychologically induced stress on plasma ghrelin levels in patients with bingeeating disorder (BED and in healthy subjects of normal or increased body mass index (BMI. Volunteers were subjected to the standardized trier social stress test (TSST. Basal ghrelin levels in patients were at an intermediate level between thin and healthy obese subjects, but this difference did not attain statistical significance. There were no differences in ghrelin levels throughout the test among the groups after correction for BMI, age and gender. A significant difference in the trend time of ghrelin was revealed when the three groups were analyzed according to their cortisol response to stress. Ghrelin levels increased in cortisol responders whereas no change or a decrease in ghrelin levels occurred in cortisol non-responders. We also found Optimal time T*, Minimal Repair δ and Random Lead Time g to minimize the ghrelin level.

  7. A Systematic Assessment of Blood Lead Level in Children and Associated Risk Factors in China.

    Science.gov (United States)

    Wang, Lu; Li, Zhen; Huang, Shao Xin; DU, Chuang; Wang, Hong; He, Li Ping; Bi, Yong Yi; Shi, Yong; Wang, Chun Hong

    2015-08-01

    In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 µg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ⋝ 100 µg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China. PMID:26383600

  8. Modelagem matemática do efeito chicote em ambientes com demanda e lead time estocásticos

    Directory of Open Access Journals (Sweden)

    José Carlos Fioriolli

    2009-04-01

    Full Text Available O aumento da variabilidade da demanda ao longo de uma cadeia de abastecimento é conhecido como Efeito Chicote (EC. A modelagem deste fenômeno é fundamental para a quantificação de sua intensidade, ajudando a reduzir seus impactos negativos sobre o nível de serviço e sobre os estoques em cadeias de abastecimento. Este artigo apresenta uma proposta de modelagem do EC que tem por objetivo aumentar a precisão na quantificação deste fenômeno em ambientes com demanda e lead time estocásticos. O novo modelo considera um elemento que não está presente nos principais modelos disponíveis na literatura: a variabilidade no lead time de entrega de pedidos. Além disso, define de modo mais preciso o papel do coeficiente de variação da demanda na quantificação do EC. A utilização do modelo proposto aumenta a eficiência da gestão de cadeias de abastecimento ao contribuir para atenuar a propagação do EC.The increase in demand variability as information flows from customers to manufacturers in a supply chain is known as the Bullwhip Effect (BE. Modeling this phenomenon is key in measuring its intensity, aiming at reducing its negative impact on both service and inventory levels in supply chains. This paper proposes a new, more precise mathematical model for quantifying the BE in systems with stochastic demand and lead time. The new model takes into account the lead time variability, an element not present in the BE literature. In addition, the model allows a more precise assessment of the role that the demand's coefficient of variation plays when quantifying the BE. The use of the proposed model enables an improved management of the supply chain by attenuating the propagation of the BE.

  9. Evaluating the applicability of regulatory leaching tests for assessing lead leachability in contaminated shooting range soils.

    Science.gov (United States)

    Cao, Xinde; Dermatas, Dimitris

    2008-04-01

    The toxicity characteristic leaching procedure (TCLP) is the current US-EPA standard protocol to evaluate metal leachability in wastes and contaminated soils. However, application of TCLP to assess lead (Pb) leachability from contaminated shooting range soils may be questionable. This study determined Pb leachability in the range soils using TCLP and another US-EPA regulatory leaching method, synthetic precipitation leaching procedure (SPLP). Possible mechanisms that are responsible for Pb leaching in each leaching protocol were elucidated via X-ray diffraction (XRD). Soil samples were collected from the backstop berms at four shooting ranges, with Pb concentrations ranging from 5,000 to 60,600 mg kg(-1) soil. Lead concentrations in the TCLP leachates were from 3 to 350 mg l(-1), with all but one soil exceeding the USEPA non-hazardous waste disposal limit of 5 mg l(-1). However, continued dissolution of metallic Pb particles from spent Pb bullets and its re-precipitation as cerussite (PbCO(3)) prevented the TCLP extraction from reaching equilibrium at the end of the standard leaching period (18 h). Thus, the standard one-point TCLP test would either over- or under-estimate Pb leachability in shooting range soils. Lead concentration in the SPLP leachates ranged from 0.021 to 2.6 mg l(-1), with all soils above the USEPA regulatory limit of 0.015 mg l(-1). In contrast to TCLP, SPLP leaching had reached equilibrium, with regard to both pH and Pb concentrations, within the standard 18 h leaching period, and the analytical SPLP results were in good agreement with those derived from modeling. Thus, we concluded that SPLP is a more appropriate alternative than TCLP for assessing lead leachability in range soils. PMID:18204911

  10. System security assessment in real-time using synchrophasor measurements

    DEFF Research Database (Denmark)

    Jóhannsson, Hjörtur; Wache, Markus

    2013-01-01

    measures to ensure stable and secure operation of the system are necessary. Time stamped synchrophasor measurements lay the foundation for development of new real-time applications for security and stability assessment. The paper provides overview of existing solutions for synchrophasor based security...... assessment and sheds light on ongoing research activities that focus on exploiting wide-area synchrophasor measurements for real-time security assessment of sustainable power systems. At last, an mathematical mapping enabling informative visualization of the system state in respect to aperiodic rotor angle...

  11. Leading safety performance indicators for resilience assessment of radiopharmaceuticals production process

    International Nuclear Information System (INIS)

    Radiopharmaceuticals are radiation-emitting substances used in medicine for radiotherapy and imaging diagnosis. A Research Institute, located in Rio de Janeiro, produces three radiopharmaceuticals: the sodium iodate is used in the diagnosis of thyroid dysfunctions, the meta-iodo-benzyl guanidine is used in the diagnosis of cardiac diseases, and the fluorodeoxyglucose is used in diagnosis in cardiology, oncology, neurology and neuro psychiatry. This paper presents a leading safety performance indicators framework to assess the resilience of radiopharmaceuticals production processes. The organizations that use resilience indicators will be able to pro actively evaluate and manage safety. (author)

  12. Leading safety performance indicators for resilience assessment of radiopharmaceuticals production process

    Energy Technology Data Exchange (ETDEWEB)

    Grecco, Claudio H.S.; Santos, Isaac J.A.L.; Carvalho, Paulo V.R., E-mail: grecco@ien.gov.b, E-mail: luquetti@ien.gov.b, E-mail: paulov@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Instrumentacao e Confiabilidade Humana; Vidal, Mario C.R., E-mail: mvidal@ergonomia.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEP/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia de Producao. Grupo de Ergonomia e Novas Tecnologias (GENTE)

    2011-07-01

    Radiopharmaceuticals are radiation-emitting substances used in medicine for radiotherapy and imaging diagnosis. A Research Institute, located in Rio de Janeiro, produces three radiopharmaceuticals: the sodium iodate is used in the diagnosis of thyroid dysfunctions, the meta-iodo-benzyl guanidine is used in the diagnosis of cardiac diseases, and the fluorodeoxyglucose is used in diagnosis in cardiology, oncology, neurology and neuro psychiatry. This paper presents a leading safety performance indicators framework to assess the resilience of radiopharmaceuticals production processes. The organizations that use resilience indicators will be able to pro actively evaluate and manage safety. (author)

  13. Note: Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    We show that well-known textbook formulae for determining the optimal base stock of the inventory system with continuous review and constant lead time can easily be extended to the case with periodic review and stochastic, sequential lead times. The provided performance measures and conditions for...

  14. Comparison of Inventory Systems with Service, Positive Lead-Time, Loss, and Retrial of Customers

    Directory of Open Access Journals (Sweden)

    A. Krishnamoorthy

    2007-01-01

    Full Text Available We analyze and compare three (s,S inventory systems with positive service time and retrial of customers. In all of these systems, arrivals of customers form a Poisson process and service times are exponentially distributed. When the inventory level depletes to s due to services, an order of replenishment is placed. The lead-time follows an exponential distribution. In model I, an arriving customer, finding the inventory dry or server busy, proceeds to an orbit with probability γ and is lost forever with probability (1−γ. A retrial customer in the orbit, finding the inventory dry or server busy, returns to the orbit with probability δ and is lost forever with probability (1−δ. In addition to the description in model I, we provide a buffer of varying (finite capacity equal to the current inventory level for model II and another having capacity equal to the maximum inventory level S for model III. In models II and III, an arriving customer, finding the buffer full, proceeds to an orbit with probability γ and is lost forever with probability (1−γ. A retrial customer in the orbit, finding the buffer full, returns to the orbit with probability δ and is lost forever with probability (1−δ. In all these models, the interretrial times are exponentially distributed with linear rate. Using matrix-analytic method, we study these inventory models. Some measures of the system performance in the steady state are derived. A suitable cost function is defined for all three cases and analyzed using graphical illustrations.

  15. Reducing Lead Times in a Two-process Cell Using Lean and Simulation

    Directory of Open Access Journals (Sweden)

    Michael J. Maas

    2015-05-01

    Full Text Available An existing power system production process includes two operations and produces twelve different part types. The first operation fills WIP carts used by the second operation. A combined lean and discrete event simulation study supported by the analysis of order history information stored in a corporate information system is presented. The goal was to identify operations alternatives that could be used to reduce customer lead time from the current 3 to 3 days to 1 to 3 days. The application of lean methods included the examination of the order history data that showed that 80% of parts ship to a single primary customer and 20% to many secondary customers. The lean part of the study further concluded that the number of WIP carts should equal the number of different products, that each WIP cart should be associated with one and only one product and that each WIP cart should be should refilled daily after orders are processed. Using a discrete event simulation model, four order processing sequencing alternatives for improving on-time delivery were evaluated. The percent of orders delivered in 1 day was maximized, with the lowest variance, by sorting all orders for the primary customer first from smallest in size to largest. The orders for the same product from the remaining customers are processed immediately after the order for the same product from the primary customer. The value of the synergistic effect of combining lean tools with simulation supported by order data extracted from the corporate information system is demonstrated.

  16. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    International Nuclear Information System (INIS)

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systematic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or Russian

  17. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    Energy Technology Data Exchange (ETDEWEB)

    Cropper, William H

    2002-11-20

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systematic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or

  18. Sequential injection analysis of lead using time-based colorimetric detection and preconcentration on an anionic-exchange resin.

    Science.gov (United States)

    Aracama, Nestor Zárate; Araújo, Alberto N; Perez-Olmos, Ricardo

    2004-04-01

    The development of a sequential injection analysis manifold for the colorimetric determination of lead in water samples is described The concentration of lead was assessed from its catalytic effect on the reaction of resazurine reduction caused by sulfide in an alkali medium. To that effect, the reaction zone was stopped at the detector, and the time interval required for the attainment of an absorbance decrease of 0.800 at the wavelength of 610 nm was estimated. Interference of other transition metals of the samples was minimized by adding potassium iodide to the sample and retaining the iodocomplexes formed in an on-line anionic resin (AGI X8). Elution was made with a 2 mol/L sodium hydroxide solution. The relationship [SIA] microg/L = 0.99 (+/- 0.11) x [ETAAS] microg/L + 0 (+/- 4) was obtained upon comparing the results given by the proposed system and by electrothermal atomization atomic absorption spectrometry (ETAAS) after the analysis of ten water samples. PMID:15116968

  19. Thermodynamic assessment of solubility and activity of iron, chromium, and nickel in lead bismuth eutectic

    Science.gov (United States)

    Gossé, Stéphane

    2014-06-01

    Lead-Bismuth Eutectic (LBE) is a heavy liquid alloy used as a coolant for the Lead-Cooled Fast Reactors and spallation target for Accelerator Driven Systems. LBE is also considered in sodium fast reactor designs as coolant in secondary circuit to avoid any occurrence of the reaction between sodium and water in steam generators. Even if this coolant presents many advantages due to its thermophysical properties, corrosion towards structural materials remains one of the major issues of LBE. Because corrosion in LBE is partly driven by dissolution processes, the solubility and chemical activity of the main elements of the alloy are the key parameters to model the related corrosion processes. Using the Calphad method and the Thermo-Calc software, a thermodynamic database was developed to assess the interaction between Cr-Ni-Fe alloys and LBE. The current thermodynamic data on the Cr-Fe-Ni + Bi-Pb quinary system was reviewed and the Bi-Cr and Cr-Pb binary phase diagrams were assessed. Fe, Cr and Ni solubilities (in at. fraction, T in K) at LBE composition were calculated: Fe solubility at LBE composition: log10 (SFe)=0.5719-4398.6T (399-1173 K) Cr solubility at LBE composition: log10 (SCr)=-0.2757-3056.1T (399-1173 K) Ni solubility at LBE composition: log10 (SNi)=2.8717-2932.9T (528-742 K) log10 (SNi)=0.2871-1006.3T (742-1173 K) Then, the thermodynamic assessment performed in this study was used to predict more accurately the Fe, Cr and Ni activities and solubilities in the case of four austenitic model alloys also studied in the framework of corrosion tests [1]. The calculated activities and solubilities provide thermodynamic data to better understand dissolution or precipitation phenomena observed during LBE corrosion processes.

  20. Using trace element content and lead isotopic composition to assess sources of PM in Tijuana, Mexico

    Science.gov (United States)

    Salcedo, D.; Castro, T.; Bernal, J. P.; Almanza-Veloz, V.; Zavala, M.; González-Castillo, E.; Saavedra, M. I.; Perez-Arvízu, O.; Díaz-Trujillo, G. C.; Molina, L. T.

    2016-05-01

    PM2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijuana during the Cal-Mex campaign from May 24 to June 5, 2010. Concentration of trace elements (Mg, Al, Ti, V, Mn, Fe, Co, Ni, Zn, Cu, Ga, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Ba, La, Ce, and Pb), and Pb isotopic composition were determined in order to study the sources of PM impacting each site. Other chemical analysis (gravimetric, elemental and organic carbon (EC/OC), and polycyclic aromatic hydrocarbons (PAHs)), were also performed. Finally, back-trajectories were calculated to facilitate the interpretation of the chemical data. Trace elements results show that CEC is a receptor site affected by mixed regional sources: sea salt, mineral, urban, and industrial. On the other hand, PQM seems to be impacted mainly by local sources. In particular, Pb at CEC is of anthropogenic, as well as crustal origin. This conclusion is supported by the lead isotopic composition, whose values are consistent with a combination of lead extracted from US mines, and lead from bedrocks in the Mexican Sierras. Some of the time variability observed can be explained using the back-trajectories.

  1. Ecological Risk Assessment of Lead (Pb after Waste Disposal from Metallurgical Industries

    Directory of Open Access Journals (Sweden)

    Jahangir Jafari

    2010-07-01

    Full Text Available Not being available sufficient information about ERA of lead, this paper provides a brief critical review to the mentioned concept. Being presented in soils, heavy metals constitute serious environmental hazards from the point of view of polluting the soils and adjoining streams and rivers. Pb is generally the metal of great concern as well as being phytotoxic. Ecological risk assessment is a process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors. Metallurgical waste like other waste materials consists not only of Pb, but also consists in large quantities relatively. The ubiquitous distribution and known toxicity of lead pollution in urban environment are posing great concern, in term of human health and environment. According to the importance and criticality of this issue, a holistic risk-based approach is inevitable at least for environmental health and monitoring (EHM. Reviewing literature, it is found that approximately most of the researches have been carried out in aquatic environments. From the other side, those carried out in terrestrial environment, are non-Pb focusing. Considering the researches pertaining to ERA, however few researches have been carried out in the field of metallurgical industries, none of them has addressed the Pb ERA in a holistic approach.

  2. Cadmium and lead in seafood from the Aratu Bay, Brazil and the human health risk assessment.

    Science.gov (United States)

    da Araújo, Cecilia Freitas Silva; Lopes, Mariângela Vieira; Vasquez, Mirian Rocha; Porcino, Thiago Santos; Ribeiro, Amanda Santos Vaz; Rodrigues, Juliana Lima Gomes; Oliveira, Sérgio Soares do Prado; Menezes-Filho, José Antonio

    2016-04-01

    This study aimed to evaluate cadmium (Cd) and lead (Pb) levels in seafood and perform a risk assessment based on individual food consumption frequency of inhabitants of the Aratu Bay, Brazil. From December 2013 to November 2014, ready-to-market seafood, including fish [pititinga (Lile piquitinga) and small green eel (Gobionellus oceanicus)], mollusks [mussel (Mytella guyanensis) and oyster (Crassostrea rhizophorae)], and crustaceans [white shrimp (Litopenaeus schmitti) and blue crab (Callinectes exasperatus)], were purchased bimonthly from a local artisanal shellfish harvester. Metal levels were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Based on the volunteer' seafood consumption, estimates of the non-carcinogenic target hazard quotients (THQs) were calculated. The annual concentrations (μg/g, w/w) of Cd were 0.007 (±0.001) in crustaceans, 0.001 (±0.0003) in fish, and 0.446 (±0.034) in mollusks. Lead levels were

  3. Cadmium and lead in seafood from the Aratu Bay, Brazil and the human health risk assessment.

    Science.gov (United States)

    Silva da Araújo, Cecilia Freitas; Lopes, Mariângela Vieira; Vaz Ribeiro, Mirian Rocha; Porcino, Thiago Santos; Vaz Ribeiro, Amanda Santos; Rodrigues, Juliana Lima Gomes; do Prado Oliveira, Sérgio Soares; Menezes-Filho, José Antonio

    2016-04-01

    This study aimed to evaluate cadmium (Cd) and lead (Pb) levels in seafood and perform a risk assessment based on individual food consumption frequency of inhabitants of the Aratu Bay, Brazil. From December 2013 to November 2014, ready-to-market seafood, including fish [pititinga (Lile piquitinga) and small green eel (Gobionellus oceanicus)], mollusks [mussel (Mytella guyanensis) and oyster (Crassostrea rhizophorae)], and crustaceans [white shrimp (Litopenaeus schmitti) and blue crab (Callinectes exasperatus)], were purchased bimonthly from a local artisanal shellfish harvester. Metal levels were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Based on the volunteer’ seafood consumption, estimates of the non-carcinogenic target hazard quotients (THQs) were calculated. The annual concentrations (μg/g, w/w) of Cd were 0.007 (±0.001) in crustaceans, 0.001 (±0.0003) in fish, and 0.446 (±0.034) in mollusks. Lead levels were

  4. Coordinated between single-vendor and single-buyer inventory model with lead time reduction and price discount

    Directory of Open Access Journals (Sweden)

    Nipaporn Wawjapo

    2014-03-01

    Full Text Available This study is to construct an inventory system model in which a single vendor supplies a product to a single buyer. The buyer uses the (R,Q inventory policy. The inventory model analyzed the problem that the ordering cost reductions depend on lead time in the continuous inspection inventory model with backorders discount. The demand during lead time is distributed as normally distribution. Also, vendor manages the complete items. Then, the minimization of the average total related cost by simultaneously optimizing the order quantity, lead time and backorder price discount is considered. Moreover, a numerical example shows that how the integrated inventory models can be applied to the system. The results indicate that the percentage of average total cost savings depends on the shortened lead time.

  5. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    Directory of Open Access Journals (Sweden)

    Hua-Ming Song

    2011-01-01

    Full Text Available This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are formulated and compared in the decentralized and centralized cases. Besides, a three-parameter contract is proposed to coordinate the supply chain and alleviate the double margin in the decentralized scenario. In addition, based on the analysis of the models, we develop an algorithmic procedure to find the optimal ordering decisions. Finally, a numerical example is also presented to illustrate the results.

  6. Coordinated between single-vendor and single-buyer inventory model with lead time reduction and price discount

    OpenAIRE

    Nipaporn Wawjapo; Piyawadee Prasongsin; Wuttichai Srisodaphol

    2014-01-01

    This study is to construct an inventory system model in which a single vendor supplies a product to a single buyer. The buyer uses the (R,Q) inventory policy. The inventory model analyzed the problem that the ordering cost reductions depend on lead time in the continuous inspection inventory model with backorders discount. The demand during lead time is distributed as normally distribution. Also, vendor manages the complete items. Then, the minimization of the average total related cost by si...

  7. Life cycle assessment (LCA of lead-free solders from the environmental protection aspect

    Directory of Open Access Journals (Sweden)

    Mitovski Aleksandra M.

    2009-01-01

    Full Text Available Life-cycle assessment (LCA presents a relatively new approach, which allows comprehensive environmental consequences analysis of a product system over its entire life. This analysis is increasingly being used in the industry, as a tool for investigation of the influence of the product system on the environment, and serves as a protection and prevention tool in ecological management. This method is used to predict possible influences of a certain material to the environment through different development stages of the material. In LCA, the product systems are evaluated on a functionally equivalent basis, which, in this case, was 1000 cubic centimeters of an alloy. Two of the LCA phases, life-cycle inventory (LCA and life-cycle impact assessment (LCIA, are needed to calculate the environmental impacts. Methodology of LCIA applied in this analysis aligns every input and output influence into 16 different categories, divided in two subcategories. The life-cycle assessment reaserch review of the leadfree solders Sn-Cu, SAC (Sn-Ag-Cu, BSA (Bi-Sb-Ag and SABC (Sn-Ag-Bi-Cu respectively, is given in this paper, from the environmental protection aspect starting from production, through application process and finally, reclamation at the end-of-life, i.e. recycling. There are several opportunities for reducing the overall environmental and human health impacts of solder used in electronics manufacturing based on the results of the LCA, such as: using secondary metals reclaimed through post-industrial recycling; power consumption reducing by replacing older, less efficient reflow assembly equipment, or by optimizing the current equipment to perform at the elevated temperatures required for lead-free soldering, etc. The LCA analysis was done comparatively in relation to widely used Sn-Pb solder material. Additionally, the impact factors of material consumption, energy use, water and air reserves, human health and ecotoxicity have been ALSO considered including

  8. Thermodynamic assessment of solubility and activity of iron, chromium, and nickel in lead bismuth eutectic

    International Nuclear Information System (INIS)

    Lead–Bismuth Eutectic (LBE) is a heavy liquid alloy used as a coolant for the Lead-Cooled Fast Reactors and spallation target for Accelerator Driven Systems. LBE is also considered in sodium fast reactor designs as coolant in secondary circuit to avoid any occurrence of the reaction between sodium and water in steam generators. Even if this coolant presents many advantages due to its thermophysical properties, corrosion towards structural materials remains one of the major issues of LBE. Because corrosion in LBE is partly driven by dissolution processes, the solubility and chemical activity of the main elements of the alloy are the key parameters to model the related corrosion processes. Using the Calphad method and the Thermo-Calc software, a thermodynamic database was developed to assess the interaction between Cr–Ni–Fe alloys and LBE. The current thermodynamic data on the Cr–Fe–Ni + Bi–Pb quinary system was reviewed and the Bi–Cr and Cr–Pb binary phase diagrams were assessed. Fe, Cr and Ni solubilities (in at. fraction, T in K) at LBE composition were calculated: Fe solubility at LBE composition:log10(SFe)=0.5719-(4398.6)/T (399–1173K) Cr solubility at LBE composition:log10(SCr)=-0.2757-(3056.1)/T (399–1173K) Ni solubility at LBE composition:log10(SNi)=2.8717-(2932.9)/T (528–742K) log10(SNi)=0.2871-(1006.3)/T (742–1173K) Then, the thermodynamic assessment performed in this study was used to predict more accurately the Fe, Cr and Ni activities and solubilities in the case of four austenitic model alloys also studied in the framework of corrosion tests [1]. The calculated activities and solubilities provide thermodynamic data to better understand dissolution or precipitation phenomena observed during LBE corrosion processes

  9. Thermodynamic assessment of solubility and activity of iron, chromium, and nickel in lead bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Gossé, Stéphane, E-mail: stephane.gosse@cea.fr

    2014-06-01

    Lead–Bismuth Eutectic (LBE) is a heavy liquid alloy used as a coolant for the Lead-Cooled Fast Reactors and spallation target for Accelerator Driven Systems. LBE is also considered in sodium fast reactor designs as coolant in secondary circuit to avoid any occurrence of the reaction between sodium and water in steam generators. Even if this coolant presents many advantages due to its thermophysical properties, corrosion towards structural materials remains one of the major issues of LBE. Because corrosion in LBE is partly driven by dissolution processes, the solubility and chemical activity of the main elements of the alloy are the key parameters to model the related corrosion processes. Using the Calphad method and the Thermo-Calc software, a thermodynamic database was developed to assess the interaction between Cr–Ni–Fe alloys and LBE. The current thermodynamic data on the Cr–Fe–Ni + Bi–Pb quinary system was reviewed and the Bi–Cr and Cr–Pb binary phase diagrams were assessed. Fe, Cr and Ni solubilities (in at. fraction, T in K) at LBE composition were calculated: Fe solubility at LBE composition:log{sub 10}(S{sub Fe})=0.5719-(4398.6)/T (399–1173K) Cr solubility at LBE composition:log{sub 10}(S{sub Cr})=-0.2757-(3056.1)/T (399–1173K) Ni solubility at LBE composition:log{sub 10}(S{sub Ni})=2.8717-(2932.9)/T (528–742K) log{sub 10}(S{sub Ni})=0.2871-(1006.3)/T (742–1173K) Then, the thermodynamic assessment performed in this study was used to predict more accurately the Fe, Cr and Ni activities and solubilities in the case of four austenitic model alloys also studied in the framework of corrosion tests [1]. The calculated activities and solubilities provide thermodynamic data to better understand dissolution or precipitation phenomena observed during LBE corrosion processes.

  10. Real Time Face Quality Assessment for Face Log Generation

    DEFF Research Database (Denmark)

    Kamal, Nasrollahi; Moeslund, Thomas B.

    2009-01-01

    Summarizing a long surveillance video to just a few best quality face images of each subject, a face-log, is of great importance in surveillance systems. Face quality assessment is the back-bone for face log generation and improving the quality assessment makes the face logs more reliable....... Developing a real time face quality assessment system using the most important facial features and employing it for face logs generation are the concerns of this paper. Extensive tests using four databases are carried out to validate the usability of the system....

  11. Research on Lead-time Compression of Inventory Integrating Remanufacturing and Manufacturing System for the IOT Environment

    Institute of Scientific and Technical Information of China (English)

    Han Shu-Xian

    2015-01-01

    The lead time compression is the core of supply chain management with time competition and the powerful source of competitive advantage of supply chain.As an emerging technology,The Internet of things is a huge network which combined Various Information sensing device (such as RFID,infrared sensors,global position system,communication device,etc.)with internet.So it can improve information sharing,cut logistical operations time and reduce lead-time.Base on the assumption that the market demand forecast accuracy varies with lead-time,this paper will establish the inventory model of the remanufacturing/manufacturing system and give the optimization algorithms of this mode.Finally,the conclusion is validated through a numerical example,proved the practicability of the model in practice.

  12. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY12 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Kulisek, Jonathan A.; Anderson, Kevin K.; Casella, Andrew M.; Siciliano, Edward R.; Warren, Glen A.

    2012-09-28

    Executive Summary Developing a method for the accurate, direct, and independent assay of the fissile isotopes in bulk materials (such as used fuel) from next-generation domestic nuclear fuel cycles is a goal of the Office of Nuclear Energy, Fuel Cycle R&D, Material Protection and Control Technology (MPACT) Campaign. To meet this goal, MPACT supports a multi-institutional collaboration, of which PNNL is a part, to study the feasibility of Lead Slowing Down Spectroscopy (LSDS). This technique is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic masses in used fuel with an uncertainty considerably lower than the approximately 10% typical of today’s confirmatory methods. This document is a progress report for FY2012 PNNL analysis and algorithm development. Progress made by PNNL in FY2012 continues to indicate the promise of LSDS analysis and algorithms applied to used fuel assemblies. PNNL further refined the semi-empirical model developed in FY2011 based on singular value decomposition (SVD) to numerically account for the effects of self-shielding. The average uncertainty in the Pu mass across the NGSI-64 fuel assemblies was shown to be less than 3% using only six calibration assemblies with a 2% uncertainty in the isotopic masses. When calibrated against the six NGSI-64 fuel assemblies, the algorithm was able to determine the total Pu mass within <2% uncertainty for the 27 diversion cases also developed under NGSI. Two purely empirical algorithms were developed that do not require the use of Pu isotopic fission chambers. The semi-empirical and purely empirical algorithms were successfully tested using MCNPX simulations as well applied to experimental data measured by RPI using their LSDS. The algorithms were able to describe the 235U masses of the RPI measurements with an average uncertainty of 2.3%. Analyses were conducted that provided valuable insight with regard to design requirements (e

  13. Assessment of Genotoxicity through ISSR Marker in Pistia stratiotes Induced by Lead

    Directory of Open Access Journals (Sweden)

    Lamyai Neeratanaphan

    2014-06-01

    Full Text Available Assessment of DNA changes in Pistia stratiotes induced by lead (Pb, plants were grown in acclimatized conditions for 15 days. Each of 5 plants were then transferred to cultivate in three repeated 0.2, 0.3, 0.5 mg/l Pb experiments, four days and controls. Lead concentration in water was analyzed by inductively-coupled plasma - mass spectrometry (ICP-MS, physical and chemical factors including temperature, pH, dissolved oxygen (DO and electro-conductivity (EC before and after the experimentation. Inter-simple sequence repeat fingerprints (ISSR were analyzed for genetic similarity values (S, and genomic template stability test (GTS was evaluated for revealing correlation of genetic structure changes and induced Pb concentration levels. The results appeared that the mean Pb concentrations in water were decreased 0.0121, 0.1688 and 0.2338 mg/l in the 3 concentration experiments, respectively. Assumedly, these Pb values loosed were adsorbed and absorbed in the plants. The physical and chemical factors such as pH, DO and EC were decreased and temperature was increased. The 10 successfully ISSR primers produced a total of 577 bands used for dendrogram construction. The plants with Pb affected 0.2, 0.3 and 0.5 mg/l were correlated by each concentration grouping and the S reveals 0.85-0.90, 0.69-0.90 and 0.93-0.96, respectively. The S value and plant's individual grouping agreement reveal its true effect by each Pb concentration. GTS values were (-2.38 - (-23.81 signifying to have most changes in DNA structure, genetic erosion occurring thoroughly on its genome, and affecting its life. These effects agreed to its morphological characters including leaves lacking chlorophyll (yellow, beginning to decay and finally dying. The research shows that P. stratiotes can be used as a bio-indicator for Pb wastewater monitoring.

  14. Evaluating the Effect of Lead Time on Quality Service Delivery in the Banking Industry in Kumasi Metropolis of Ghana

    Directory of Open Access Journals (Sweden)

    Stephen Okyere

    2015-07-01

    Full Text Available Customers are becoming more attracted to quality service delivery and are being impatience and unsatisfied when they had to be delayed or wait for longer times before they are served.  Hence, Quality Service Delivery is of utmost importance to every service organisation especially financial industry. Most financial institutions focus attention on product innovation at the expense of lead time management which is a major factor in ensuring service quality and customer satisfaction. Consequently, this research looks at evaluating the effect of lead time on quality service delivery in the Banking Industry in Kumasi Metropolis of Ghana. The study relied on Primary data collected through questionnaires, observation and interview instruments, administered to staff and customers of some selected branches of a commercial bank in the study area. The data was analysed qualitatively. The researchers realised that despite the immense importance of lead time on quality service delivery, little attention is given to the concept. It was revealed that, customers were dissatisfied with the commercial bank’s services as a result of the unnecessary delays and queuing at the bank premises. The long lead time was found to be attributable to plant/system failure, skill gap on the part of employees, ATM underutilization and frequent breakdowns, among others. This has consequently resulted into long lead time, waiting, queuing and unnecessary delay at the banking hall. It is recommended that Tellers should be provided with electronic card readers for verification of customer’s data and processing to be faster.

  15. Assessing accumulation and sublethal effects of lead in a unionid mussel

    Science.gov (United States)

    Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Kwak, Thomas J.; Shea, Damian

    2012-01-01

    Lead (Pb) contamination of the environment remains a global problem. Previous studies have demonstrated that Pb deposited onto roadside sediments from the past use of leaded gasoline in vehicles may be mobilized into rivers and streams, thereby resulting in exposure to aquatic biota. The aims of this study were to conduct a 28-day laboratory toxicity test with Pb and adult Eastern Elliptio (Elliptio complanata; family Unionidae) mussels to determine uptake kinetics and to assess several potential non-lethal biomarkers of Pb exposure. Mussels were collected from a relatively uncontaminated reference site and exposed to a control and eight concentrations of Pb (as lead nitrate) ranging from 1 to 251 µg/L, as a static renewal test. There were five replicates per treatment with one mussel per replicate. The hemolymph of mussels from four of the replicates was repeatedly sampled (days 7, 14, 21, and 28) for analysis of Pb and ion (Na+, K+, Cl-, Ca2+) concentrations. The mussels in the fifth replicate per treatment were only sampled on day 28 and served as a comparison to the repeatedly sampled mussels. The accumulation of Pb in mussel tissue was also evaluated during the study. No mussels died during the test. We found that measured concentrations of Pb in mussel hemolymph suggested regulation of the heavy metal up to 66 μg/L by day 14, whereas concentrations in tissue proved to be strongly correlated (R2 = 0.98; p mussel hemolymph, which can be sampled and measured non-lethally, is a suitable marker of recent Pb exposure in mussels. In contrast, none of the ion concentrations measured in the hemolymph from the repeatedly sampled mussels was significantly changed with increasing concentrations of Pb, whereas the mussels from the fifth replicate sampled only on day 28 showed altered calcium concentrations. The activity of δ-aminolevulinic acid dehydratase (ALAD), a demonstrated Pb-specific biomarker in vertebrates and some invertebrates, which was also evaluated as a

  16. Simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul Allen; Ford, Corey C. (University of New Mexico, Albuquerque, NM)

    2008-04-01

    U.S. soldiers are surviving blast and impacts due to effective body armor, trauma evacuation and care. Blast injuries are the leading cause of traumatic brain injury (TBI) in military personnel returning from combat. Understanding of Primary Blast Injury may be needed to develop better means of blast mitigation strategies. The objective of this paper is to investigate the effects of blast direction and strength on the resulting mechanical stress and wave energy distributions generated in the brain.

  17. Time-varying interaction leads to amplitude death in coupled nonlinear oscillators

    Indian Academy of Sciences (India)

    Awadhesh Prasad

    2013-09-01

    A new form of time-varying interaction in coupled oscillators is introduced. In this interaction, each individual oscillator has always time-independent self-feedback while its interaction with other oscillators are modulated with time-varying function. This interaction gives rise to a phenomenon called amplitude death even in diffusively coupled identical oscillators. The nonlinear variation of the locus of bifurcation point is shown. Results are illustrated with Landau–Stuart (LS) and Rössler oscillators.

  18. ARAC: a flexible real-time dose consequence assessment system

    International Nuclear Information System (INIS)

    ARAC (the Atmospheric Release Advisory Capability), an emergency radiological dose assessment capability of the U.S. Government, has been called on to do consequence assessments for releases into the atmosphere of radionuclides and a variety of other substances. Because of the variety of requirements of each unique assessment, ARAC has developed and maintains a flexible system of people, computer software and hardware. A new version of ADPIC that can simulate the transport of any number of radionuclide particulates and gases and all of the decay products that are generated during transport and after deposition. This code will be most suitable for application to nuclear reactor accidents. ARAC has personal computer and advanced computer workstations at approximately 50 remote sites that communicate central system and which can initiate an ARAC response by transmitting time, location and source information about an accident to the central system

  19. Biotests and biosensors in ecotoxicological risk assessment of field soils polluted with zinc, lead, and cadmium.

    Science.gov (United States)

    Kahru, Anne; Ivask, Angela; Kasemets, Kaja; Põllumaa, Lee; Kurvet, Imbi; François, Matthieu; Dubourguier, Henri-Charles

    2005-11-01

    The combined chemical and ecotoxicological hazard evaluation study was conducted on 60 smelter-influenced soils containing 1 to 13, 50 to 653, and 100 to 1,198 mg/kg of Cd, Pb, and Zn, respectively. For these soils (liquid-to-soil ratio = 10), water extractability of Zn, Cd, and Pb was less than 0.19% (median values). Acetic acid (0.11 M) extracted 23, 9.7, and 0.7% of Cd, Zn, and Pb, respectively. Although heavy metal concentrations in the studied soils were high, the toxic effects of water extracts were observed only in few samples and in few biotests (algae Selenastrum capricornutum and metal detector assay). For most of the aquatic test organisms (e.g., crustaceans, photobacteria), the bioavailable concentrations of metals in soil-water extracts were either subtoxic, or the adverse effects were compensated by soil nutrients, etc. However, analysis of the soils with recombinant Cd sensor Bacillus subtilis (pTOO24) showed that about 65% of these apparently subtoxic samples contained bioavailable Cd when analyzed in the suspension assay (detection limit 1.5 mg Cd/kg soil), indicating the desorption of Cd induced by direct contact of bacteria with soil particles. The median bioavailable fraction of Cd (1%) was 23-fold lower than the fraction extracted by acetic acid. The Pb-Cd sensor Staphylococcus aureus (pT0024) detected bioavailable Pb only in the suspensions of five of the most lead-polluted soils (>417 mg Pb/kg): the median bioavailability of Pb was 0.42%. Consequently, the hazard assessment relying on total metal levels in soils should be revised by critical comparison with data obtained from bioassays. Development and use of biosensors (excellent tools for mechanistic studies and signaling hazard already at subtoxic level) should be encouraged. PMID:16398136

  20. Assessing coupling dynamics from an ensemble of time series

    CERN Document Server

    Gomez-Herrero, German; Rutanen, Kalle; Soriano, Miguel C; Pipa, Gordon; Vicente, Raul

    2010-01-01

    Finding interdependency relations between (possibly multivariate) time series provides valuable knowledge about the processes that generate the signals. Information theory sets a natural framework for non-parametric measures of several classes of statistical dependencies. However, a reliable estimation from information-theoretic functionals is hampered when the dependency to be assessed is brief or evolves in time. Here, we show that these limitations can be overcome when we have access to an ensemble of independent repetitions of the time series. In particular, we gear a data-efficient estimator of probability densities to make use of the full structure of trial-based measures. By doing so, we can obtain time-resolved estimates for a family of entropy combinations (including mutual information, transfer entropy, and their conditional counterparts) which are more accurate than the simple average of individual estimates over trials. We show with simulated and real data that the proposed approach allows to reco...

  1. Lead-time analysis and a control policy for production lines

    OpenAIRE

    Economopoulos, Angelos A; Kouikoglou, Vassilis S

    2010-01-01

    Abstract We address a control problem for a production line which produces one product to stock and faces random demand. During stockouts, the system quotes a fixed response time for each arriving order, and the customers place their orders only if the response time promised meets their deadlines. Customer orders are filled on a first come, first served basis. A penalty cost is incurred whenever a customer is served later than promised. A two-parameter admission/inventory control p...

  2. Finite-time full counting statistics and factorial cumulants for transport through a quantum dot with normal and superconducting leads

    International Nuclear Information System (INIS)

    We study the finite-time full counting statistics for subgap transport through a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. In particular, we determine the factorial and the ordinary cumulants both for finite times and in the long-time limit. We find that the factorial cumulants violate the sign criterion, indicating a non-binomial distribution, even in absence of Coulomb repulsion due to the presence of superconducting correlations. At short times the cumulants exhibit oscillations which are a signature of the coherent transfer of Cooper pairs between the dot and the superconductor. (paper)

  3. Assessment of semen function and lipid peroxidation among lead exposed men

    International Nuclear Information System (INIS)

    The study population included healthy, fertile men, employees of Zinc and Lead Metalworks (n = 63). Workers exposed to lead were divided into two groups: a group with moderate exposure to lead (ME) - blood lead level (PbB) 25-40 μg/dl and a group with high exposure to lead (HE) PbB = 40-81 μg/dl. The control group consisted of office workers with no history of occupational exposure to lead. Evaluation of lead, cadmium and zinc level in blood and seminal plasma, zinc protoporphyrin in blood (ZPP), 5-aminolevulinic acid in urine (ALA), malondialdehyde (MDA) in seminal plasma and sperm analysis were performed. No differences were noted in the concentration of cadmium and zinc in blood and seminal plasma in the study population. Lipid peroxidation in seminal plasma, represented as MDA concentration, significantly increased by about 56% in the HE group and the percentage of motile sperm cells after 1 h decreased by about 34% in comparison to the control group. No statistically significant correlation between other parameters of sperm analysis and lead exposure parameters nor between lead, cadmium and zinc concentration in blood and seminal plasma were found. A positive association between lead intoxication parameters (PbB, ZPP, lead seminal plasma) and MDA concentration in sperm plasma and inverse correlation with sperm cells motility (PbB, ZPP) was found. An increased concentration of MDA was accompanied by a drop in sperm cells motility. In conclusion, we report that high exposure to lead causes a decrease of sperm motility in men most likely as a result of increased lipid peroxidation, especially if the level in the blood surpasses the concentration of 40 μg/dl

  4. Assessment of lead exposure in Spanish imperial eagle (Aquila adalberti) from spent ammunition in central Spain

    Science.gov (United States)

    Fernandez, Julia Rodriguez-Ramos; Hofle, Ursula; Mateo, Rafael; de Francisco, Olga Nicolas; Abbott, Rachel; Acevedo, Pelayo; Blanco, Juan-Manuel

    2011-01-01

    The Spanish imperial eagle (Aquila adalberti) is found only in the Iberian Peninsula and is considered one of the most threatened birds of prey in Europe. Here we analyze lead concentrations in bones (n = 84), livers (n = 15), primary feathers (n = 69), secondary feathers (n = 71) and blood feathers (n = 14) of 85 individuals collected between 1997 and 2008 in central Spain. Three birds (3.6%) had bone lead concentration > 20 (mu or u)g/g and all livers were within background lead concentration. Bone lead concentrations increased with the age of the birds and were correlated with lead concentration in rachis of secondary feathers. Spatial aggregation of elevated bone lead concentration was found in some areas of Montes de Toledo. Lead concentrations in feathers were positively associated with the density of large game animals in the area where birds were found dead or injured. Discontinuous lead exposure in eagles was evidenced by differences in lead concentration in longitudinal portions of the rachis of feathers.

  5. A noninvasive isotopic approach to estimate the bone lead contribution to blood in children: Implications for assessing the efficacy of lead abatement

    OpenAIRE

    Gwiazda, Roberto H; C. Campbell; Smith, D.

    2005-01-01

    Lead hazard control measures to reduce children's exposure to household lead sources often result in only limited reductions in blood lead levels. This may be due to incomplete remediation of lead sources and/or to the remobilization of lead stores from bone, which may act as an endogenous lead source that buffers reductions in blood lead levels. Here we present a noninvasive isotopic approach to estimate the magnitude of the bone lead contribution to blood in children following household lea...

  6. Bounds on performance measures for the (r, q) lost sales system with Poisson demand and constant lead time

    OpenAIRE

    Johnston, Bryan

    2013-01-01

    We demonstrate that the fraction of sales lost for the (r, q) system under consideration can be conveniently bounded in a manner suitable for quick, back-of-the-envelope estimates. We assume that customer demand arises from a Poisson process with one unit demanded at a time, that all demand occurring during a stockout is lost, and that lead time is constant. In addition, we allow the situation where multiple replenishment orders may be simultaneously outstanding. We show that the difference b...

  7. Revisiting the question: Does high-latitude solar activity lead low-latitude solar activity in time phase?

    International Nuclear Information System (INIS)

    Cross-correlation analysis and wavelet transform methods are used to investigate whether high-latitude solar activity leads low-latitude solar activity in time phase or not, using the data of the Carte Synoptique solar filaments archive from 1919 March to 1989 December. From the cross-correlation analysis, high-latitude solar filaments have a time lead of 12 Carrington solar rotations with respect to low-latitude ones. Both the cross-wavelet transform and wavelet coherence indicate that high-latitude solar filaments lead low-latitude ones in time phase. Furthermore, low-latitude solar activity is better correlated with high-latitude solar activity of the previous cycle than with that of the following cycle, which is statistically significant. Thus, the present study confirms that high-latitude solar activity in the polar regions is indeed better correlated with the low-latitude solar activity of the following cycle than with that of the previous cycle, namely, leading in time phase.

  8. Observing expertise-related actions leads to perfect time flow estimations.

    Science.gov (United States)

    Chen, Yin-Hua; Pizzolato, Fabio; Cesari, Paola

    2013-01-01

    The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second) of visual displays both specific (a hand in piano-playing action) and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels) and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists' enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration. PMID:23405131

  9. Observing expertise-related actions leads to perfect time flow estimations.

    Directory of Open Access Journals (Sweden)

    Yin-Hua Chen

    Full Text Available The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second of visual displays both specific (a hand in piano-playing action and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists' enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration.

  10. Action and perception are temporally coupled by a common mechanism that leads to a timing misperception.

    Science.gov (United States)

    Pretegiani, Elena; Astefanoaei, Corina; Daye, Pierre M; FitzGibbon, Edmond J; Creanga, Dorina-Emilia; Rufa, Alessandra; Optican, Lance M

    2015-01-28

    We move our eyes to explore the world, but visual areas determining where to look next (action) are different from those determining what we are seeing (perception). Whether, or how, action and perception are temporally coordinated is not known. The preparation time course of an action (e.g., a saccade) has been widely studied with the gap/overlap paradigm with temporal asynchronies (TA) between peripheral target onset and fixation point offset (gap, synchronous, or overlap). However, whether the subjects perceive the gap or overlap, and when they perceive it, has not been studied. We adapted the gap/overlap paradigm to study the temporal coupling of action and perception. Human subjects made saccades to targets with different TAs with respect to fixation point offset and reported whether they perceived the stimuli as separated by a gap or overlapped in time. Both saccadic and perceptual report reaction times changed in the same way as a function of TA. The TA dependencies of the time change for action and perception were very similar, suggesting a common neural substrate. Unexpectedly, in the perceptual task, subjects misperceived lights overlapping by less than ∼100 ms as separated in time (overlap seen as gap). We present an attention-perception model with a map of prominence in the superior colliculus that modulates the stimulus signal's effectiveness in the action and perception pathways. This common source of modulation determines how competition between stimuli is resolved, causes the TA dependence of action and perception to be the same, and causes the misperception. PMID:25632126

  11. Assessing recognition memory using confidence ratings and response times.

    Science.gov (United States)

    Weidemann, Christoph T; Kahana, Michael J

    2016-04-01

    Classification of stimuli into categories (such as 'old' and 'new' in tests of recognition memory or 'present' versus 'absent' in signal detection tasks) requires the mapping of internal signals to discrete responses. Introspective judgements about a given choice response are regularly employed in research, legal and clinical settings in an effort to measure the signal that is thought to be the basis of the classification decision. Correlations between introspective judgements and task performance suggest that such ratings often do convey information about internal states that are relevant for a given task, but well-known limitations of introspection call the fidelity of this information into question. We investigated to what extent response times can reveal information usually assessed with explicit confidence ratings. We quantitatively compared response times to confidence ratings in their ability to qualify recognition memory decisions and found convergent results suggesting that much of the information from confidence ratings can be obtained from response times. PMID:27152209

  12. Investigation of the Adaptability of Transient Stability Assessment Methods to Real-Time Operation

    DEFF Research Database (Denmark)

    Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Sommer, Stefan;

    2012-01-01

    In this paper, an investigation of the adaptability of available transient stability assessment methods to real-time operation and their real-time performance is carried out. Two approaches based on Lyapunov’s method and the equal area criterion are analyzed. The results allow to determine the...... runtime of each method with respect to the number of inputs. Furthermore, it allows to identify, which method is preferable in case of changes in the power system such as the integration of distributed power resources (DER). A comparison of the performance of the analyzed methods leads to the suggestion...

  13. Reduction of Working Time: Does It Lead to a Healthy Lifestyle?

    Science.gov (United States)

    Ahn, Taehyun

    2016-08-01

    I examine whether working hours have a causal effect on the health behaviors of workers. In assessing the causal relationship, I estimate fixed-effects instrumental variable models by using exogenous variation in adopting a reduced workweek in South Korea as an instrument for work hours. The estimation results reveal that shortening work hours induces individuals to exercise regularly and decreases the likelihood of smoking, with more pronounced effects for heavy smokers. While a work-hour reduction substantially increases the probability of drinking participation, it does not significantly affect the likelihood of frequent or daily drinking habits. In addition, the effect of a work-hour reduction on regular exercise is salient among women and older groups, and the effect on smoking behaviors is more pronounced among men and middle-aged groups. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25974857

  14. Real Time Host Assessment using ANN for Grid Network

    Directory of Open Access Journals (Sweden)

    T.R.Srinivasan

    2010-10-01

    Full Text Available In this work, we study the efficacy of assessing registered hosts for job allocation using Artificial neural network to classify registered hosts during job scheduling. Grid is evolving as the computing structure of the future. The success in commercial grid computing is the ability to negotiate resource sharing arrangements with a set of registered participating parties. Grid computing is capable of integrating services across distributed heterogeneous disparate resources with a centralized control to provide quality of service.Host assessment plays a crucial role to assign a specific job in thegrid. Host selection among the registered pool of hosts can drastically improve the quality of service. Resource discoveryalgorithms are available but identifying ideal resource to reducequeue time and response time is the most essential task in a commercial grid environment. Resource mining is the process of running data through sophisticated algorithms to uncover meaningful patterns and co relations that may otherwise be hidden. We explore theapplication of these techniques to assess host by training thesystem with known data. Experimental results show an improvement of 25.49 percent in data classification using ANN over normal methods.

  15. Development of a real-time radiological dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Han, Moon Hee; Lee, Young Bok; Kim, Eun Han; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil

    1997-07-01

    A radiological dose assessment system named FADAS has been developed. This system is necessary to estimated the radiological consequences against a nuclear accident. Mass-consistent wind field module was adopted for the generation of wind field over the whole domain using the several measured wind data. Random-walk dispersion module is used for the calculation of the distribution of radionuclides in the atmosphere. And volume-equivalent numerical integration method has been developed for the assessment of external gamma exposure given from a randomly distributed radioactive materials and a dose data library has been made for rapid calculation. Field tracer experiments have been carried out for the purpose of analyzing the site-specific meteorological characteristics and increasing the accuracy of wind field generation and atmospheric dispersion module of FADAS. At first, field tracer experiment was carried out over flat terrain covered with rice fields using the gas samplers which were designed and manufactured by the staffs of KAERI. The sampled gas was analyzed using gas chromatograph. SODAR and airsonde were used to measure the upper wind. Korean emergency preparedness system CARE was integrated at Kori 4 nuclear power plants in 1995. One of the main functions of CARE is to estimate the radiological dose. The developed real-time dose assessment system FADAS was adopted in CARE as a tool for the radiological dose assessment. (author). 79 refs., 52 tabs., 94 figs.

  16. Comparison of time corrections using charge amounts, peak values, slew rates, and signal widths in leading-edge discriminators

    International Nuclear Information System (INIS)

    Leading-edge discriminators (LEDs) are one of the prominent discriminator technologies used in time-of-flight systems due to their simplicity, but they have large time walks such that the measured time should be corrected using amplitude information. In this article, we analyze off-line time corrections using four kinds of amplitude parameters, namely, peak values, slew rates, and signal widths, as well as charge amounts. For these corrections, we developed the front-end electronics (FEE) that can measure these amplitude parameters and performed time measurements with the developed FEE in an amplitude range of about 20 dB for various threshold conditions, which are the only adjustment in LEDs. Then, we off-line corrected the measured time using the amplitude parameters mentioned above and compared the corrected efficiencies by the used parameters and threshold conditions

  17. Assessment of Lead and Cadmium Levels in Frequently Used Cosmetic Products in Iran

    OpenAIRE

    Nourmoradi, H.; M. Foroghi; Farhadkhani, M.; M Vahid Dastjerdi

    2013-01-01

    This study aims to investigate the content of lead and cadmium in most frequently used brands of cosmetic products (lipstick and eye shadow) in Iran. Fifty samples of lipstick (5 colors in 7 brands) and eye shadow (3 colors in 5 brands) were selected taken from large cosmetic stores in Isfahan (Iran) and lead and cadmium of them were analyzed. The results showed that the concentration of lead and cadmium in the lipsticks was within the range of 0.08–5.2  µ g/g and 4.08–60.20  µ g/g, respectiv...

  18. Evaluation and assessment of the efficacy of an abatement strategy in a former lead smelter community, Boolaroo, Australia.

    Science.gov (United States)

    Harvey, P J; Taylor, M P; Kristensen, L J; Grant-Vest, S; Rouillon, M; Wu, L; Handley, H K

    2016-08-01

    This study examines the recent soil Lead Abatement Strategy (LAS) in Boolaroo, New South Wales, Australia, that was designed to "achieve a reduction in human exposure to lead dust contamination in surface soils". The abatement programme addressed legacy contamination of residential areas following closure of lead smelting operations in 2003 at the Pasminco Cockle Creek Smelter (PCCS). The principal objective of the LAS was to "cap and cover" lead-contaminated soils within the urban environment surrounding the PCCS. Soil lead concentrations of 2500-5000 mg/kg were scheduled for removal and replacement, while concentrations between 1500 and 2500 mg/kg were replaced only under limited circumstances. To date, there has been no industry, government or independent assessment of the clean-up programme that involved >2000 homes in the township of Boolaroo. Thus, by measuring post-abatement soil lead concentrations in Boolaroo, this study addresses this knowledge gap and evaluates the effectiveness of the LAS for reducing the potential for lead exposure. Soil lead concentrations above the Australian residential soil health investigation level value for residential soils (300 mg/kg) were identified at all but one of the residential properties examined (n = 19). Vacuum dust samples (n = 17) from the same homes had a mean lead concentration of 495 mg/kg (median 380 mg/kg). Bio-accessibility testing revealed that lead in household vacuum dust was readily accessible (% bio-accessible) (mean = 92 %, median = 90 %), demonstrating that the risk of exposure via this pathway remains. Assessment of a limited number of properties (n = 8) where pre-abatement soil lead levels were available for comparison showed they were not statistically different to post-abatement. Although the LAS did not include treatment of non-residential properties, sampling of community areas including public sports fields, playgrounds and schools (n = 32) was undertaken to determine the

  19. Waiting time distribution for the first conception leading to a live birth

    International Nuclear Information System (INIS)

    An attempt has been made in this paper to obtain probability model describing the distribution of the waiting time from marriage to first conception based on the data from marriage to first live birth. The speciality of this present approach lies in assuming the marital exposure to be finite which was assumed to be infinite by most of the earlier investigators for mathematical simplicity. Illustration of the applicability of the model on the data pertaining to first order of conception and monthly probability of conception for women married at different age groups have been illustrated in this paper. (author)

  20. The right side? Under time pressure, approach motivation leads to right-oriented bias.

    Science.gov (United States)

    Roskes, Marieke; Sligte, Daniel; Shalvi, Shaul; De Dreu, Carsten K W

    2011-11-01

    Approach motivation, a focus on achieving positive outcomes, is related to relative left-hemispheric brain activation, which translates to a variety of right-oriented behavioral biases. In two studies, we found that approach-motivated individuals display a right-oriented bias, but only when they are forced to act quickly. In a task in which they had to divide lines into two equal parts, approach-motivated individuals bisected the line at a point farther to the right than avoidance-motivated individuals did, but only when they worked under high time pressure. In our analysis of all Fédération Internationale de Football Association (FIFA) World Cup penalty shoot-outs, we found that goalkeepers were two times more likely to dive to the right than to the left when their team was behind, a situation that we conjecture induces approach motivation. Because penalty takers shot toward the two sides of the goal equally often, the goalkeepers' right-oriented bias was dysfunctional, allowing more goals to be scored. Directional biases may facilitate group coordination but prove maladaptive in individual settings and interpersonal competition. PMID:22006059

  1. Assessment of Tetracycline, Lead and Cadmium Residues in Frozen Chicken Vended in Lagos and Ibadan, Nigeria

    OpenAIRE

    Belleh Efie Diana; Adetunji Victoria Olusola; Odetokun Ismail Ayoade

    2012-01-01

    This study determined the levels of tetracycline and heavy metals (lead and cadmium) levels in frozen chicken. One hundred frozen chicken muscle samples were sourced from major markets in Lagos and Ibadan (fifty samples each). The samples were analyzed using High Power Liquid Chromatography (HPLC) for tetracycline residue determination while Atomic Absorption Spectroscopy (AAS) was used to determine the levels of lead and cadmium residues in the samples. Mean concentrations of tetracycline re...

  2. Error assessment of satellite-derived lead fraction in the Arctic

    OpenAIRE

    Ivanova, Natalia; Rampal, Pierre; Bouillon, Sylvain

    2016-01-01

    Leads within consolidated sea ice control heat exchange between the ocean and the atmosphere during winter, thus constituting an important climate parameter. These narrow elongated features occur when sea ice is fracturing under the action of wind and currents, reducing the local mechanical strength of the ice cover, which in turn impact the sea ice drift pattern. This creates a high demand for a high-quality lead fraction (LF) data set for sea ice model evaluation, initiali...

  3. Assessment of lead and cadmium levels in frequently used cosmetic products in Iran.

    Science.gov (United States)

    Nourmoradi, H; Foroghi, M; Farhadkhani, M; Vahid Dastjerdi, M

    2013-01-01

    This study aims to investigate the content of lead and cadmium in most frequently used brands of cosmetic products (lipstick and eye shadow) in Iran. Fifty samples of lipstick (5 colors in 7 brands) and eye shadow (3 colors in 5 brands) were selected taken from large cosmetic stores in Isfahan (Iran) and lead and cadmium of them were analyzed. The results showed that the concentration of lead and cadmium in the lipsticks was within the range of 0.08-5.2  µ g/g and 4.08-60.20  µ g/g, respectively. The eye shadow samples had a lead level of 0.85-6.90  µ g/g and a cadmium level of 1.54-55.59  µ g/g. The content range of the heavy metals in the eye shadows was higher than that of the lipsticks. There was significant difference between the average of the lead content in the different brands of the lipsticks and eye shadows. Thus, the continuous use of these cosmetics can increase the absorption of heavy metals, especially Cd and Pb, in the body when swallowing lipsticks or through dermal cosmetic absorption. The effects of heavy metals such as lead can be harmful, especially for pregnant women and children. Therefore, effort must be made to inform the users and the general public about the harmful consequences of cosmetics. PMID:24174937

  4. Assessment of Lead and Cadmium Levels in Frequently Used Cosmetic Products in Iran

    Directory of Open Access Journals (Sweden)

    H. Nourmoradi

    2013-01-01

    Full Text Available This study aims to investigate the content of lead and cadmium in most frequently used brands of cosmetic products (lipstick and eye shadow in Iran. Fifty samples of lipstick (5 colors in 7 brands and eye shadow (3 colors in 5 brands were selected taken from large cosmetic stores in Isfahan (Iran and lead and cadmium of them were analyzed. The results showed that the concentration of lead and cadmium in the lipsticks was within the range of 0.08–5.2 µg/g and 4.08–60.20 µg/g, respectively. The eye shadow samples had a lead level of 0.85–6.90 µg/g and a cadmium level of 1.54–55.59 µg/g. The content range of the heavy metals in the eye shadows was higher than that of the lipsticks. There was significant difference between the average of the lead content in the different brands of the lipsticks and eye shadows. Thus, the continuous use of these cosmetics can increase the absorption of heavy metals, especially Cd and Pb, in the body when swallowing lipsticks or through dermal cosmetic absorption. The effects of heavy metals such as lead can be harmful, especially for pregnant women and children. Therefore, effort must be made to inform the users and the general public about the harmful consequences of cosmetics.

  5. Assessing Coupling Dynamics from an Ensemble of Time Series

    Directory of Open Access Journals (Sweden)

    Germán Gómez-Herrero

    2015-04-01

    Full Text Available Finding interdependency relations between time series provides valuable knowledge about the processes that generated the signals. Information theory sets a natural framework for important classes of statistical dependencies. However, a reliable estimation from information-theoretic functionals is hampered when the dependency to be assessed is brief or evolves in time. Here, we show that these limitations can be partly alleviated when we have access to an ensemble of independent repetitions of the time series. In particular, we gear a data-efficient estimator of probability densities to make use of the full structure of trial-based measures. By doing so, we can obtain time-resolved estimates for a family of entropy combinations (including mutual information, transfer entropy and their conditional counterparts, which are more accurate than the simple average of individual estimates over trials. We show with simulated and real data generated by coupled electronic circuits that the proposed approach allows one to recover the time-resolved dynamics of the coupling between different subsystems.

  6. Assessment of and proposal for a mechanistic interpretation of the SCC of high nickel alloys in lead-containing environments

    International Nuclear Information System (INIS)

    The SCC of Alloys 600 and 690 in lead-containing solutions, 'lead stress corrosion cracking' (PbSCC) is quite aggressive on tubing in conditions of operation of steam generators (SG) in pressurized water reactors (PWR). Lead dissolved in water can produce PbSCC at concentrations of Pb as low as 0.1 ppm in these alloys. PbSCC is perhaps the most generally aggressive of the environmental species that occur in SGs. This discussion considers the occurrence of Pb in SGs and the PbSCC that can result. The dependencies of PbSCC on the variables of pH, potential, species, alloy composition, alloy structure, temperature and stress are reviewed. Also, important features of the mechanism of PbSCC are assessed. The most significant question related to PbSCC is why more is not occurring in view of the low thresholds for the PbSCC and the ubiquity of the Pb. While there are usually no common specific sources for Pb in most secondary systems, Pb concentrates on surfaces of tubing efficiently over long times. Regardless, it appears that extensive PbSCC does not occur because it is immobilized by forming stable compounds with other species such as sulfur, carbon, phosphorous and silica. Pb is also immobilized by forming stable adsorbed states with oxides such as magnetite and hematite. The possibility of releasing Pb to produce PbSCC increases as water chemistry produces more pure systems and as chemical cleaning is used. Contrary to the common assumption that PbSCC is TGSCC, that of Alloy 600MA is generally IGSCC; only the sensitized (SN), stress relieved (SR) and thermally treated (TT) conditions of Alloys 600 and 690 sustain TGSCC in Pb-containing solutions. In view of the prevailing IGSCC produced by Pb in MA materials, the possibility of all IGSCC in SGs being due to Pb should be considered where crevice environments are in the nominally neutral range. TGSCC that is observed in SGs can be produced by other, although not widely appreciated, environments. The mechanism of Pb

  7. Use of Atomic Absorption Spectrometry in Assessment of Biomonitor Plants for Lead, Cadmium and Copper Pollution

    Institute of Scientific and Technical Information of China (English)

    Gokce Kaya; Mehmet Yaman

    2012-01-01

    Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep,Turkey.Lead,cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry.Lead,Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304~602,0.4~0.44 and 31~37 mg · kg-1,respectively.Significantly increased lead concentration up to 2 750 mg · kg-1 was found in the leaves of Eleagnus angustifolia L.plant.The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima >Morus sp.> Juglans regia L.> Ficus carica L.>Cydonia oblonga Miller> Prunus x domestica L.The plants,Populus nigra L.,Eleagnus angustifolia L.and Salix sp.were found useful for Cd,and the plant,Eleagnus angustifolia L.for Pb,to be considered as potential biomonitor.Especially,leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations.Therefore,people who and animals which live in this area and benefit from these soil and plants have vital risks.

  8. Use of atomic absorption spectrometry in assessment of biomonitor plants for lead, cadmium and copper pollution.

    Science.gov (United States)

    Gokce, Kaya; Mehmet, Yaman

    2012-01-01

    Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep, Turkey. Lead, cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry. Lead, Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304-602, 0.4-0.44 and 31-37 mg x kg(-1), respectively. Significantly increased lead concentration up to 2 750 mg x kg(-1) was found in the leaves of Eleagnus angustifolia L. plant. The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima > Morus sp. > Juglans regia L. > Ficus carica L. > Cydonia oblonga Miller > Prunus x domestica L. The plants, Populus nigra L. , Eleagnus angustifolia L. and Salix sp. were found useful for Cd, and the plant, Eleagnus angusti folia L. for Pb, to be considered as potential biomonitor. Especially, leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations. Therefore, people who and animals which live in this area and benefit from these soil and plants have vital risks. PMID:22497165

  9. Lead Toxicity

    Science.gov (United States)

    ... in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or ... avoid exposure to soil. Is there a medical test for lead exposure? • Blood samples can be tested ...

  10. An integrated supply chain inventory model with imperfect-quality items, controllable lead time and distribution-free demand

    Directory of Open Access Journals (Sweden)

    Lin Hsien-Jen

    2013-01-01

    Full Text Available In this paper, we consider an integrated vendor-buyer inventory policy for a continuous review model with a random number of defective items and screening process gradually at a fixed screening rate in buyer’s arriving order lot. We assume that shortages are allowed and partially backlogged on the buyer’s side, and that the lead time demand distribution is unknown, except its first two moments. The objective is to apply the minmax distribution free approach to determine the optimal order quantity, reorder point, lead time and the number of lots delivered in one production run simultaneously so that the expected total system cost is minimized. Numerical experiments along with sensitivity analysis were performed to illustrate the effects of parameters on the decision and the total system cost.

  11. Robust design of (s, S) inventory policy parameters in supply chains with demand and lead time uncertainties

    Science.gov (United States)

    Karimi Movahed, Kamran; Zhang, Zhi-Hai

    2015-09-01

    Demand and lead time uncertainties have significant effects on supply chain behaviour. In this paper, we present a single-product three-level multi-period supply chain with uncertain demands and lead times by using robust techniques to study the managerial insights of the supply chain inventory system under uncertainty. We formulate this problem as a robust mixed-integer linear program with minimised expected cost and total cost variation to determine the optimal (s, S) values of the inventory parameters. Several numerical studies are performed to investigate the supply chain behaviour. Useful guidelines for the design of a robust supply chain are also provided. Results show that the order variance and the expected cost in a supply chain significantly increase when the manufacturer's review period is an integer ratio of the distributor's and the retailer's review periods.

  12. Open source and healthcare in Europe - time to put leading edge ideas into practice.

    Science.gov (United States)

    Murray, Peter J; Wright, Graham; Karopka, Thomas; Betts, Helen; Orel, Andrej

    2009-01-01

    Free/Libre and Open Source Software (FLOSS) is a process of software development, a method of licensing and a philosophy. Although FLOSS plays a significant role in several market areas, the impact in the health care arena is still limited. FLOSS is promoted as one of the most effective means for overcoming fragmentation in the health care sector and providing a basis for more efficient, timely and cost effective health care provision. The 2008 European Federation for Medical Informatics (EFMI) Special Topic Conference (STC) explored a range of current and future issues related to FLOSS in healthcare (FLOSS-HC). In particular, there was a focus on health records, ubiquitous computing, knowledge sharing, and current and future applications. Discussions resulted in a list of main barriers and challenges for use of FLOSS-HC. Based on the outputs of this event, the 2004 Open Steps events and subsequent workshops at OSEHC2009 and Med-e-Tel 2009, a four-step strategy has been proposed for FLOSS-HC: 1) a FLOSS-HC inventory; 2) a FLOSS-HC collaboration platform, use case database and knowledge base; 3) a worldwide FLOSS-HC network; and 4) FLOSS-HC dissemination activities. The workshop will further refine this strategy and elaborate avenues for FLOSS-HC from scientific, business and end-user perspectives. To gain acceptance by different stakeholders in the health care industry, different activities have to be conducted in collaboration. The workshop will focus on the scientific challenges in developing methodologies and criteria to support FLOSS-HC in becoming a viable alternative to commercial and proprietary software development and deployment. PMID:19745456

  13. Assessment of DNA damage in mussels exposed to lead as a single contaminant and a refinery effluent component

    International Nuclear Information System (INIS)

    The sensitivity of a freshwater mussel species, Anodonta grandis, to DNA damage following lead exposure was tested in laboratory and field exposures. Mussels were exposed in laboratory aquaria to lead nitrate at the following Pb concentrations: 0 (controls), 50, 500, and 5,000 μg/L in a static renewal protocol for four weeks. In a separate experiment, mussels wee exposed to lead and other petroleum refinery effluent contaminants in cage mesocosms placed on and above the sediments of a settling pond at an abandoned oil refinery for four and twenty-four week's exposure. Control mussels were caged at a noncontaminated pond offsite the refinery grounds. The effects of lead exposure on DNA integrity were assessed in field and laboratory-exposed mussels. Average DNA strand length was measured in control and Pb-exposed mussels by agarose gel electrophoresis of DNA extracts isolated from adductor muscle, foot, and mantle tissue. Lead accumulation by mussels was also quantified by atomic absorption spectroscopy of acid-digested tissues. DNA damage in lead-exposed mussels will be related to tissue lead accumulation, exposure length, and exposure type

  14. Lead exposure: assessment of the risk for the general Italian population.

    Science.gov (United States)

    Morisi, G; Patriarca, M; Carrieri, M P; Fondi, G; Taggi, F

    1989-01-01

    According to the regulations contained in the presidential decree DPR 496/82 certain Italian regions have carried out investigations--based on the blood lead level measurement--for the biological surveillance of the general population against the risk of saturnism. A work-group from the Istituto Superiore di Sanità (Italian National Institute of Health) coordinated the activity of the various centers and organized an appropriate quality control program to guarantee the quality of the analytical data collected. A total of 8635 subjects (4864 females and 3771 males) have been examined, 1968 of which (1058 females and 910 males) were under 14 years of age. The median values of the observed blood lead levels were, for the adults, 153 micrograms/l in males and 100 micrograms/l in females; and, for the children, 94 micrograms/l in males and 86 micrograms/l in females. The reference limit decreed by law for the 98th percentile is exceeded by the adult-males group, while both limits, at the 90th and 98th percentiles are exceeded by the population residing in the Portoscuso (CA) municipality. Our investigation confirms the correlation between blood lead levels, alcohol consumption, and cigarette smoking; in both sexes and in all age groups (except for females 15-25 years of age) a positive correlation of blood lead levels with alcohol consumption and cigarette smoking is clearly evident. The association of blood lead levels with alcohol seems to be stronger than that with cigarette smoking. The comparison with the results of previous investigations shows a 25% reduction of blood lead levels in the general Italian population during the 1979-1985 period. PMID:2624354

  15. Three-Echelon Inventory Model with Permissible Delay in Payments under Controllable Lead Time and Backorder Consideration

    OpenAIRE

    Yang, M.F.; Wei-Chung Tseng

    2014-01-01

    This paper proposes a three-echelon inventory model with permissible delay in payments under controllable lead time and backorder consideration to find out the suitable inventory policy to enhance profit of the supply chain. In today’s highly competitive market, the supply chain management has become a critical issue in both practice and academic and supply chain members have to cooperate with each other to bring more benefits. In addition, the inventory policy is a key factor to influence th...

  16. Periodic Review Probabilistic Multi-Item Inventory System with Zero Lead Time under Constraints and Varying Order Cost

    OpenAIRE

    FERGANY, Hala A.

    2005-01-01

    This study treats the probabilistic safety stock n-items inventory system having varying order cost and zero lead-time subject to two linear constraints. The expected total cost is composed of three components: the average purchase cost; the expected order cost and the expected holding cost. The policy variables in this model are the number of periods Nr* and the optimal maximum inventory level Qmr* and the minimum expected total cost. We can obtain the optimal values of these policy variable...

  17. Solution and vapour deposited lead perovskite solar cells: Ecotoxicity from a life cycle assessment perspective

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Serrano-Luján, Lucía; Urbina, Antonio;

    2015-01-01

    inventory for all the components employed for the two different device architectures that resemble respectively a traditional dye sensitised solar cell (DSSC) and an inverted polymer solar cell (OPV). We analyse the impacts from generation of 1 kWh of electricity and assume a lifetime of 1 year in the...... lead(II)halides is very limited compared to methylammoniumhalides employed. This applies during the raw materials extraction, synthesis of the starting materials and manufacture of the perovskite solar cells and from these points of view the lead based perovskite solar cells do not pose extra concerns...

  18. (Q, R inventory model with service level constraint and variable lead time in fuzzy-stochastic environment

    Directory of Open Access Journals (Sweden)

    Hardik Soni

    2011-10-01

    Full Text Available In today's global marketplace, individual firms do not compete as independent entities rather as an integral part of a supply chain. Uncertainty is the main attribute in managing the supply chains. Accordingly, we develop a (Q, R inventory model with service level constraint and variable lead-time in fuzzy-stochastic environment. In addition, the triangular fuzzy numbers counts upon lead-time are used to construct fuzzy-stochastic lead-time demand. Using credibility criterion, the expected shortages are calculated. Without loss of generality, we assume that all the observed values of the fuzzy random variable, representing the demand are triangular fuzzy numbers. Consequently, the value of total expected cost in the fuzzy sense is derived using the expected value criterion or credibility criterion. To determine an optimal policy, a numerical technique is presented and the results are analyzed using scan and zoom for constraint optimization. Finally, in order to demonstrate the accuracy and effectiveness of the proposed model, numerical example and sensitivity analysis are also included.

  19. BIOLOGICAL ASSESSMENT OF CONTINUOUS EXPOSURE TO TRITIUM AND LEAD IN THE RAT

    Science.gov (United States)

    In an attempt to contribute information on the effects of simultaneous exposure to two potentially synergistic environmental pollutants the authors have chronically administered tritiated water (HTO) and lead (Pb) to rats. HTO and Pb were selected because they are ubiquitous in t...

  20. Lead-time reduction utilizing lean tools applied to healthcare: the inpatient pharmacy at a local hospital.

    Science.gov (United States)

    Al-Araidah, Omar; Momani, Amer; Khasawneh, Mohammad; Momani, Mohammed

    2010-01-01

    The healthcare arena, much like the manufacturing industry, benefits from many aspects of the Toyota lean principles. Lean thinking contributes to reducing or eliminating nonvalue-added time, money, and energy in healthcare. In this paper, we apply selected principles of lean management aiming at reducing the wasted time associated with drug dispensing at an inpatient pharmacy at a local hospital. Thorough investigation of the drug dispensing process revealed unnecessary complexities that contribute to delays in delivering medications to patients. We utilize DMAIC (Define, Measure, Analyze, Improve, Control) and 5S (Sort, Set-in-order, Shine, Standardize, Sustain) principles to identify and reduce wastes that contribute to increasing the lead-time in healthcare operations at the pharmacy understudy. The results obtained from the study revealed potential savings of > 45% in the drug dispensing cycle time. PMID:20151593

  1. Assessment of the degree of certainty of double phase diagrams of lead systems with elements of the periodic table

    International Nuclear Information System (INIS)

    Present article is devoted to assessment of the degree of certainty of double phase diagrams of lead systems with elements of the periodic table. The analysis of literature data on double phase diagrams of lead with elements of the periodic table was carried out. It was found that from 91 systems Pb-e (element) was studied and constructed diagrams for 50 systems. It was defined that in most cases the constructed state diagrams have to be confirmed by using more cleaner initial source materials and modern methods of physicochemical analysis and thermodynamic calculations.

  2. Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant.

    Science.gov (United States)

    Zamani, Abbas Ali; Yaftian, Mohammad Reza; Parizanganeh, Abdolhossein

    2012-01-01

    The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran) for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP). Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs). Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area. PMID:23369182

  3. Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant

    Directory of Open Access Journals (Sweden)

    Zamani Abbas Ali

    2012-12-01

    Full Text Available Abstract The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP. Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs. Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area.

  4. TIME-2, Radioactive Waste Disposal Climatic Change Risk Assessment

    International Nuclear Information System (INIS)

    1 - Description of program or function: TIME2 simulates the long-term evolution burial facilities for radioactive waste disposal, and forms part of a development programme in time-dependent probabilistic risk analysis. Environmental change in the model is essentially driven by changes in climatic conditions based on the geological record of climate changes and the astronomical or 'Milankovitch' theory of climates. The environment is modelled up to the first glaciation from the present. Processes brought on by climatic change such as glacial advance, sea-level changes, water budget, and erosion effects are considered, as well as human intrusion effects, each as a separate sub-model within the overall framework of the model. 2 - Method of solution: TIME2 is a Monte Carlo simulation code which models environmental change by random sampling of the parameters which are anticipated to vary with time within quantifiable limits. Probabilistic distribution functions for these parameters are provided by the user as input, and values are then sampled during each simulation of the code. Sampling occurs several times within each defined climate state type into which the changing climatic conditions from the present to the next Ice Age are divided (Temperate, Boreal, Tundra and Glacial). In addition a Savannah climate is modelled in the near future (500-1500 years) if the 'greenhouse effect' is to be simulated). The sampling of these environmental parameters occurs at specific time steps during a simulation which correspond either to the times of transition from one climate state to another, or to fixed user-specified times. The climate state durations are themselves sampled at the start of each simulation. Occurrences of human intrusion events are sampled separately for each time step and their effects assessed. A particular case involving input values which simulate conditions for example for a given site and repository, would typically include several thousand simulations so

  5. Applied Time Domain Stability Margin Assessment for Nonlinear Time-Varying Systems

    Science.gov (United States)

    Kiefer, J. M.; Johnson, M. D.; Wall, J. H.; Dominguez, A.

    2016-01-01

    margins. At each time point, the system was linearized about the current operating point using Simulink's built-in solver. Each linearized system in time was evaluated for its rigid-body gain margin (high frequency gain margin), rigid-body phase margin, and aero gain margin (low frequency gain margin) for each control axis. Using the stability margins derived from the baseline linearization approach, the time domain derived stability margins were determined by executing time domain simulations in which axis-specific incremental gain and phase adjustments were made to the nominal system about the expected neutral stability point at specific flight times. The baseline stability margin time histories were used to shift the system gain to various values around the zero margin point such that a precise amount of expected gain margin was maintained throughout flight. When assessing the gain margins, the gain was applied starting at the time point under consideration, thereafter following the variation in the margin found in the linear analysis. When assessing the rigid-body phase margin, a constant time delay was applied to the system starting at the time point under consideration. If the baseline stability margins were correctly determined via the linear analysis, the time domain simulation results should contain unstable behavior at certain gain and phase values. Examples will be shown from repeated simulations with variable added gain and phase lag. Faithfulness of margins calculated from the linear analysis to the nonlinear system will be demonstrated.

  6. Roman lead and copper mining in Germany : their origin and development through time, deduced from lead and copper isotope provenance studies

    OpenAIRE

    Durali-Müller, Soodabeh

    2006-01-01

    The present work was devised to address the systematic analysis of samples from a range of Roman non-ferrous metal artefacts from different archaeological contexts and sites in the Roman provinces of Germania Superior. One of the focal points of this study is the provenancing of different lead objects from five important Roman settlements between 15 BC and the beginning of fourth century AD. For this purpose, measurements were made on lead and copper ore samples from the Siegerland, Eifel, Hu...

  7. Environmental Assessment for the off-site commercial cleaning of lead and asbestos contaminated laundry from the Savannah River Site

    International Nuclear Information System (INIS)

    This Environmental Assessment (EA) has been prepared by the Department of Energy (DOE) to assess the potential environmental impacts of off-site commercial cleaning of lead and asbestos contaminated laundry generated at the Savannah River Site (SRS), located near Aiken, South Carolina. The proposed action constitutes an addition to the already-implemented action of sending controlled and routine SRS laundry to an off-site commercial facility for cleaning. This already-implemented action was evaluated in a previous EA (i.e., DOE/EA-0990; DOE, 1994) prepared under the National Environmental Policy Act of 1969 (NEPA)

  8. Use of grit supplements by waterbirds: an experimental assessment of strategies to reduce lead poisoning

    OpenAIRE

    Martínez-Haro, Mónica; Green, Andy J.; Acevedo, Pelayo; Mateo, Rafael

    2010-01-01

    Abstract The ingestion of spent Pb shot due to confusion with grit or inadvertently with food particles causes Pb poisoning in a large number of waterbirds, this being one of the main causes of mortality for some species. Lead ammunition for hunting is being progressively banned in more countries, while grit supplementation has been proposed as a management measure to reduce the ingestion of deposited Pb shot. Studies of grit selection with waterfowl in semi-captivity and in the wi...

  9. Time-dependent reliability analysis and condition assessment of structures

    Energy Technology Data Exchange (ETDEWEB)

    Ellingwood, B.R. [Johns Hopkins Univ., Baltimore, MD (United States)

    1997-01-01

    Structures generally play a passive role in assurance of safety in nuclear plant operation, but are important if the plant is to withstand the effect of extreme environmental or abnormal events. Relative to mechanical and electrical components, structural systems and components would be difficult and costly to replace. While the performance of steel or reinforced concrete structures in service generally has been very good, their strengths may deteriorate during an extended service life as a result of changes brought on by an aggressive environment, excessive loading, or accidental loading. Quantitative tools for condition assessment of aging structures can be developed using time-dependent structural reliability analysis methods. Such methods provide a framework for addressing the uncertainties attendant to aging in the decision process.

  10. Development and suitability of in vitro digestion models in assessing bioaccessibility of lead from toy matrices

    NARCIS (Netherlands)

    Oomen AG; Twillert K van; Hofhuis MFA; Rompelberg CJM; Versantvoort CHM; SIR; ARO

    2003-01-01

    Children can be orally exposed to compounds by chewing, sucking and ingestion of toy (parts). Only the fraction of contaminant that is released from the toy can reach the blood stream (internal exposure) and can contribute to toxicity. In present risk assessment the release of contaminants from toy

  11. Symposium on intermediate-range atmospheric-transport processes and technology assessment. [Lead Abstract

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-01

    Separate abstracts were prepared for the 47 papers in this proceedings. The purpose of this meeting was to assess the state of the art of modeling atmospheric transport processes 10 to 100 km downwind of point and area sources of pollution. (KRM)

  12. Assessment of lead distribution in aquatic plant Lemna minor, using sequential extraction procedure

    International Nuclear Information System (INIS)

    Complete text of publication follows. The contamination of water resources by toxic metals demands for attention since this kind of contamination, sometimes, is difficult to realize. Moreover, lead, for instance, has the capacity to be accumulated in fish and plants utilized in the food, and also in human beings, causing several disturbances. Phytoremediation is an emerging technology that employs the use of plants for the clean-up of contaminated environments. The model plant Lemna minor is a genera of Duckweed plant, and refers to a group of floating, flowering plants of the family Lemnaceae. The aquatic plant Lemna minor is relevant to many aquatic environments, including lakes, streams, effluent, rain, and sediment. The aquatic plant Lemna minor has been studied due its potential to extract lead from contaminated waters. The aim of this study was to determine the distribution of Pb in the aquatic plant Lemna minor under stress, using a modified sequential extraction with different solvents: hexane, ethyl acetate, 2-propanol, methanol, ethanol/water (1:1) and water. Non-extractable residues formed the last fraction. Elemental distributions in the plants were determined using flame atomic absorption spectroscopy (F AAS), and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). It was found that the aquatic plant L. minor has the capacity to accumulate lead: in the first day of contamination, about 79% of lead had been intake by the plant. After 7 days, the Pb content was 142 mg Kg-1. After sequential extraction, the methanol and ethanol/water fractions were dominants: 27 and 45% of total content, respectively. In these fractions we can find acids that form specific chelating agents, such as oligopeptides (phytochelatins). The hexane, ethyl acetate, and 2-propanol fractions gave the smallest isolated fraction. These fractions consisted of non-polar lipid compounds. Elemental distribution by X-ray fluorescence spectra and maps

  13. THE SINGLE-VENDOR SINGLE-BUYER INTEGRATED INVENTORY PROBLEM WITH QUALITY IMPROVEMENT AND LEAD TIME REDUCTION — MINIMAX DISTRIBUTION-FREE APPROACH

    OpenAIRE

    LIANG-YUH OUYANG; KUN-SHAN WU; CHIA-HUEI HO

    2006-01-01

    In past two decades, the Japanese successful experience in using Just-In-Time (JIT) production has received a great deal of attention. The underlying goal of JIT is to eliminate waste. This can be achieved through various efforts, such as shortening lead time and improving quality. In this paper, we investigate the impact of investing in quality improvement and lead time reduction on the integrated vendor-buyer inventory model with partial backorders. We assume that the lead time demand proba...

  14. Properties of three-body decay functions derived with time-like jet calculus beyond leading order

    International Nuclear Information System (INIS)

    Three-body decay functions in time-like parton branching are calculated using the jet calculus to the next-to-leading logarithmic (NLL) order in perturbative quantum chromodynamics (QCD). The phase space contributions from each of the ladder diagrams and interference diagrams are presented. We correct part of the results for the three-body decay functions calculated previously by two groups. Employing our new results, the properties of the three-body decay functions in the regions of soft partons are examined numerically. Furthermore, we examine the contribution of the three-body decay functions modified by the restriction resulting from the kinematical boundary of the phase space for two-body decay in the parton shower model. This restriction leads to some problems for the parton shower model. For this reason, we propose a new restriction introduced by the kinematical boundary of the phase space for two-body decay. (author)

  15. Assessment of Tetracycline, Lead and Cadmium Residues in Frozen Chicken Vended in Lagos and Ibadan, Nigeria

    Directory of Open Access Journals (Sweden)

    Belleh Efie Diana

    2012-01-01

    Full Text Available This study determined the levels of tetracycline and heavy metals (lead and cadmium levels in frozen chicken. One hundred frozen chicken muscle samples were sourced from major markets in Lagos and Ibadan (fifty samples each. The samples were analyzed using High Power Liquid Chromatography (HPLC for tetracycline residue determination while Atomic Absorption Spectroscopy (AAS was used to determine the levels of lead and cadmium residues in the samples. Mean concentrations of tetracycline residue levels in the frozen chicken sampled ranged from 1.1589-1.0463ppm which is higher than the maximum residue limit set by international food safety agencies. Pb contents were higher in chicken muscles sampled from markets in Ibadan (0.0227±0.0069 μg dL-1 than Lagos (0.0207±0.0082 μg dL-1, while Cd levels were 0.0013 μg dL-1 higher than in the Lagos samples (0.0065±0.0026 μg dL-1. These values were within maximum residue limits. There were no significant differences (p<0.05 in levels of tetracycline, lead and cadmium levels from the two market locations (Lagos and Ibadan and parts (wings and thigh muscles. However, significant differences occurred in tetracycline and Pb levels in frozen chicken sourced from Cotonou. Though not significant, tetracycline contents in the thigh muscles of the frozen chicken samples was higher than that of the wings muscles and this was attributed to the site of administration of antibiotic injection and failure to observe the pre-slaughter withdrawal period by the farmers. This study is of public health importance as the presence of these residues above the maximum residue limit in frozen chicken predisposes consumers to drug resistance, allergic reactions and poisoning as a result of toxicity.

  16. Environmental health risk assessment of ambient lead levels in Lisbon, Portugal: A full chain study approach

    DEFF Research Database (Denmark)

    Casimiro, E.; Philippe Ciffroy, P.; Serpa, P.; Johansson, E.; Legind, Charlotte Nielsen; Brochot, C.

    The multi-causality interactions between environment and health are complex and call for an integrated multidisciplinary study approach. Emerging computational toxicology tools that link toxicology, chemistry, environmental sciences, biostatistics, and computer sciences are proving to be very...... then used to calculate the Pb concentration in various biota (leafy vegetables, root vegetables, grain, potatoes, and fruits) produced in the area as well as the amount of Pb a typical adult would inhale and ingest during this ten-year assessment period. The PBPK model of the 2FUN player was used to...... calculate the Pb levels in the various body systems. Our results showed a low health risk from Pb exposures. It also identified that ingestion of leafy vegetables (i.e. lettuce, cabbage, and spinach) and fruits contribute the most to total Pb blood levels. This full chain assessment approach of the 2FUN...

  17. The application of EOQ and lead time crashing cost models in material with limited life time (Case study: CN-235 Aircraft at PT Dirgantara Indonesia)

    Science.gov (United States)

    Agustina Hidayat, Yosi; Ria Kasanah, Aprilia; Yudhistira, Titah

    2016-02-01

    PT. Dirgantara Indonesia, one of State Owned Enterprises engaging in the aerospace industry, targets to control 30% of world market for light and medium sized aircraft. One type of the aircrafts produced by PT. DI every year is CN-235. Currently, the cost of material procurement reaches 50% of the total cost of production. Material has a variety of characteristics, one of which is having a lifetime. The demand characteristic of the material with expiration for the CN-235 aircraft is deterministic. PT DI does not have any scientific background for its procurement of raw material policy. In addition, there are two methods of transportation used for delivering materials, i.e. by land and air. Each method has different lead time. Inventory policies used in this research are deterministic and probabilistic. Both deterministic and probabilistic single and multi-item inventory policies have order quantity, time to order, reorder point, and lead time as decision variables. The performance indicator for this research is total inventory cost. Inventory policy using the single item EOQ and considering expiration factor inventory results in a reduction in total costs up to 69.58% and multi item results in a decrease in total costs amounted to 71.16%. Inventory policy proposal using the model of a single item by considering expiration factor and lead time crashing cost results in a decrease in total costs amounted to 71.5% and multi item results in a decrease in total costs amounted to 71.62%. Subsequently, wasted expired materials, with the proposed models have been successfully decreased to 95%.

  18. DNA damage and repair assessed by comet assay in workers exposed to lead in a battery recycling.

    Directory of Open Access Journals (Sweden)

    Mahara Valverde

    2015-05-01

    In addition to these findings, DNA damage determined by comet assay was sensible to reflect lead exposure levels related to specific activities inside this factory. Human biomonitoring studies through comet assay could be robust when additional biomarkers are determined at time.

  19. Error assessment of satellite-derived lead fraction in the Arctic

    Science.gov (United States)

    Ivanova, Natalia; Rampal, Pierre; Bouillon, Sylvain

    2016-03-01

    Leads within consolidated sea ice control heat exchange between the ocean and the atmosphere during winter, thus constituting an important climate parameter. These narrow elongated features occur when sea ice is fracturing under the action of wind and currents, reducing the local mechanical strength of the ice cover, which in turn impact the sea ice drift pattern. This creates a high demand for a high-quality lead fraction (LF) data set for sea ice model evaluation, initialization, and for the assimilation of such data in regional models. In this context, an available LF data set retrieved from satellite passive microwave observations (Advanced Microwave Scanning Radiometer - Earth Observing System, AMSR-E) is of great value, which has been providing pan-Arctic light- and cloud-independent daily coverage since 2002. In this study errors in this data set are quantified using accurate LF estimates retrieved from Synthetic Aperture Radar (SAR) images employing a threshold technique. A consistent overestimation of LF by a factor of 2-4 is found in the AMSR-E LF product. It is shown that a simple adjustment of the upper tie point used in the method to estimate the LF can reduce the pixel-wise error by a factor of 2 on average. Applying such an adjustment to the full data set may thus significantly increase the quality and value of the original data set.

  20. Periodic Review Probabilistic Multi-Item Inventory System with Zero Lead Time under Constraint and Varying Holding Cost

    OpenAIRE

    Naglaa H. El-Sodany

    2011-01-01

    Problem statement: This study treats the probabilistic safety stock n-items inventory system having varying holding cost and zero lead-time subject to linear constraint. Approach: The expected total cost is composed of three components: the average purchase cost; the expected order cost and the expected holding cost. Results: The policy variables for this model are the number of periods N*r and the optimal maximum inventory level Q*mr and the minimum expected total cost. Conclusion/Recom...

  1. Coordinating lead-time and safety stock decisions in a two-echelon supply chain with autocorrelated consumer demand

    OpenAIRE

    Boute, Robert; Disney, Stephen; Lambrecht, Marc; Van Houdt, Benny

    2010-01-01

    In this paper we study a two-echelon supply chain with a retailer serving a consumer who is sensitive to marketing and pricing promotions. This results in either positively or negatively autocorrelated demand. Based on the observed consumer demand, the retailer replenishes with an adaptive order-up-to inventory policy satisfying a pre-specified fill rate. We assume the manufacturer produces the retailer’s orders on a make-to-order basis and he decides on the lead time based on the retailer...

  2. Modelagem matemática do efeito chicote em ambientes com demanda e lead time estocásticos

    OpenAIRE

    José Carlos Fioriolli; Flávio Sanson Fogliatto

    2009-01-01

    O aumento da variabilidade da demanda ao longo de uma cadeia de abastecimento é conhecido como Efeito Chicote (EC). A modelagem deste fenômeno é fundamental para a quantificação de sua intensidade, ajudando a reduzir seus impactos negativos sobre o nível de serviço e sobre os estoques em cadeias de abastecimento. Este artigo apresenta uma proposta de modelagem do EC que tem por objetivo aumentar a precisão na quantificação deste fenômeno em ambientes com demanda e lead time estocásticos. O no...

  3. An integrated supply chain inventory model with imperfect-quality items, controllable lead time and distribution-free demand

    OpenAIRE

    Lin Hsien-Jen

    2013-01-01

    In this paper, we consider an integrated vendor-buyer inventory policy for a continuous review model with a random number of defective items and screening process gradually at a fixed screening rate in buyer’s arriving order lot. We assume that shortages are allowed and partially backlogged on the buyer’s side, and that the lead time demand distribution is unknown, except its first two moments. The objective is to apply the minmax distribution free approach to determine the optimal orde...

  4. Assessment of Hair Aluminum, Lead, and Mercury in a Sample of Autistic Egyptian Children: Environmental Risk Factors of Heavy Metals in Autism

    Directory of Open Access Journals (Sweden)

    Farida El Baz Mohamed

    2015-01-01

    Full Text Available Background and Aims. The etiological factors involved in the etiology of autism remain elusive and controversial, but both genetic and environmental factors have been implicated. The aim of this study was to assess the levels and possible environmental risk factors and sources of exposure to mercury, lead, and aluminum in children with autism spectrum disorder (ASD as compared to their matched controls. Methods. One hundred ASD children were studied in comparison to 100 controls. All participants were subjected to clinical evaluation and measurement of mercury, lead, and aluminum through hair analysis which reflects past exposure. Results. The mean Levels of mercury, lead, and aluminum in hair of the autistic patients were significantly higher than controls. Mercury, lead, and aluminum levels were positively correlated with maternal fish consumptions, living nearby gasoline stations, and the usage of aluminum pans, respectively. Conclusion. Levels of mercury, lead, and aluminum in the hair of autistic children are higher than controls. Environmental exposure to these toxic heavy metals, at key times in development, may play a causal role in autism.

  5. Risk assessment of lead contamination for small mammal food chains (case studyfor shooting ranges)

    OpenAIRE

    Al Sayegh-Petkovšek, Samar; Tome, Davorin; Pokorny, Boštjan

    2010-01-01

    Pb levels were measured in tissues of small mammals (Microtus agrestis, Apodemus flavicollis, Sorex araneus and Crocidura leucodon), inhabiting shooting ranges of the Slovenian Army (Apače, Bač, Bloška polica, Crngrob, Mačkovec, Poček); in addition, Pb content was analysed in their diet as well. The present research was performed with the aim to confirm the use of small mammals as bioindicators of Pb contamination of shooting ranges and to performthe risk assessment of military shooting range...

  6. Assessment of Lead in Human Deciduous Teeth as Indicator for Environment Pollution

    International Nuclear Information System (INIS)

    The study was carried out on 232 shed and extracted human primary teeth from 227 children ranging from 6 to 13 years of age, both genders were involved, collected from public dental health services and private clinics, from Helwan as an industrial area and Heliopolis as a non industrial area at Cairo, Egypt. Only teeth without fillings were used, and carious substance was removed from carious lesions before the analysis was carried out. The statistical results demonstrate that, Pb concentration is highly significantly increased (P≤0.001) in primary teeth of Helwan groups than in Heliopolis one; also the Pb concentration is increased in the presence of roots and caries (P≤0.001) and it affected by the tooth group. The tooth lead concentrations showed a falling gradient from the incisors to the molars (P≤ 0.001)

  7. Extract fetal ECG from single-lead abdominal ECG by de-shape short time Fourier transform and nonlocal median

    CERN Document Server

    Li, Su

    2016-01-01

    The multiple fundamental frequency detection problem and the source separation problem from a single-channel signal containing multiple oscillatory components and a nonstationary noise are both challenging tasks. To extract the fetal electrocardiogram (ECG) from a single-lead maternal abdominal ECG, we face both challenges. In this paper, we propose a novel method to extract the fetal ECG signal from the single channel maternal abdominal ECG signal, without any additional measurement. The algorithm is composed of three main ingredients. First, the maternal and fetal heart rates are estimated by the de-shape short time Fourier transform, which is a recently proposed nonlinear time-frequency analysis technique; second, the beat tracking technique is applied to accurately obtain the maternal and fetal R peaks; third, the maternal and fetal ECG waveforms are established by the nonlocal median. The algorithm is evaluated on a simulated fetal ECG signal database ({\\em fecgsyn} database), and tested on two real data...

  8. Mississippi Valley-type lead-zinc deposits through geological time: Implications from recent age-dating research

    Science.gov (United States)

    Leach, D.L.; Bradley, D.; Lewchuk, Michael T.; Symons, David T. A.; De Marsily, G.; Brannon, J.

    2001-01-01

    Remarkable advances in age dating Mississippi Valley-type (MVT) lead-zinc deposits provide a new opportunity to understand how and where these deposits form in the Earth's crust. These dates are summarized and examined in a framework of global tectonics, paleogeography, fluid migration, and paleoclimate. Nineteen districts have been dated by paleomagnetic and/or radiometric methods. Of the districts that have both paleomagnetic and radiometric dates, only the Pine Point and East Tennessee districts have significant disagreements. This broad agreement between paleomagnetic and radiometric dates provides added confidence in the dating techniques used. The new dates confirm the direct connection between the genesis of MVT lead-zinc ores with global-scale tectonic events. The dates show that MVT deposits formed mainly during large contractional tectonic events at restricted times in the history of the Earth. Only the deposits in the Lennard Shelf of Australia and Nanisivik in Canada have dates that correspond to extensional tectonic events. The most important period for MVT genesis was the Devonian to Permian time, which corresponds to a series of intense tectonic events during the assimilation of Pangea. The second most important period for MVT genesis was Cretaceous to Tertiary time when microplate assimilation affected the western margin of North America and Africa-Eurasia. There is a notable paucity of MVT lead-zinc ore formation following the breakup of Rodinia and Pangea. Of the five MVT deposits hosted in Proterozoic rocks, only the Nanisivik deposit has been dated as Proterozoic. The contrast in abundance between SEDEX and MVT lead-zinc deposits in the Proterozoic questions the frequently suggested notion that the two types of ores share similar genetic paths. The ages of MVT deposits, when viewed with respect to the orogenic cycle in the adjacent orogen suggest that no single hydrologic model can be universally applied to the migration of the ore fluids

  9. Lead Time Reduction in Budget and Storage Space Restricted Lot Size Reorder Point Inventory Models with Controllable Negative Exponential Backorder Rate

    OpenAIRE

    A. Gholami-Qadikolaei; M. A. Sobhanallahi; Mirzazadeh, A

    2013-01-01

    This study presents the mixed backorder and lost sales inventory models involving four variables; order quantity, lead time, safety factor (a discrete variable) and backorder rate. A controllable negative exponential backorder rate is considered in the proposed model. In the real market, as unsatisfied demands occur, the longer length of lead time is, the smaller proportion of backorder rate would be. Considering this reason, backorder rate is dependent on the length of lead time through the ...

  10. Assessing efficiency of road contracts can lead to less risk, more innovation says civil engineer

    OpenAIRE

    Nystrom, Lynn A.

    2008-01-01

    The most recent survey of the nation's highway infrastructure, conducted by the American Society of Civil Engineers in 2005, indicated that the U.S. road system is in poor condition, a marked contrast from the 1988 survey by the National Council on Public Works Improvement. At that time, the nation's roads were cited to be in better than fair condition.

  11. Proposal of lead time reduction in the thermoelectric products line of a small company in the State of Sao Paulo

    Directory of Open Access Journals (Sweden)

    Fernanda Veríssimo Soulé

    2016-03-01

    Full Text Available Quick Response Manufacturing (QRM is a way manufacturing companies may increase their flexibility. Manufacturing flexibility is a key to differentiation and enhancement of competitiveness. There is few empirical research on the topic of how small and medium-sized enterprises (SME may benefit from QRM, what may impact the appropriation of this approach by these important actors of our economy. This article aims to present the results of a project which applied QRM to reduce the lead time of a small company located in the state of Sao Paulo. It was proposed to a balance the throughputs of slow operations, reducing 50% of production batches; b implement cellular manufacturing and improvements in the management of Work In Process, using the POLCA system and visual management; c implement an integrated sales and operations planning (S&OP and rules for prioritization of orders. It was identified that the proposal would generate a lead time reduction from 39 to 21.3 days and a decrease of at least 51% in the raw materials stock costs. During the research, the following conclusions could be drawn: a problems in management, investment capacity and relationship with suppliers are frequent in family-owned SMEs; b QRM approach can be adapted to work within this environment; c the knowledge developed in academia can be an important tool to help family-owned SMEs to supplant these obstacles.

  12. Chlorine doping reduces electron-hole recombination in lead iodide perovskites: time-domain ab initio analysis.

    Science.gov (United States)

    Liu, Jin; Prezhdo, Oleg V

    2015-11-19

    Rapid development in lead halide perovskites has led to solution-processable thin film solar cells with power conversion efficiencies close to 20%. Nonradiative electron-hole recombination within perovskites has been identified as the main pathway of energy losses, competing with charge transport and limiting the efficiency. Using nonadiabatic (NA) molecular dynamics, combined with time-domain density functional theory, we show that nonradiative recombination happens faster than radiative recombination and long-range charge transfer to an acceptor material. Doping of lead iodide perovskites with chlorine atoms reduces charge recombination. On the one hand, chlorines decrease the NA coupling because they contribute little to the wave functions of the valence and conduction band edges. On the other hand, chlorines shorten coherence time because they are lighter than iodines and introduce high-frequency modes. Both factors favor longer excited-state lifetimes. The simulation shows good agreement with the available experimental data and contributes to the comprehensive understanding of electronic and vibrational dynamics in perovskites. The generated insights into design of higher-efficiency solar cells range from fundamental scientific principles, such as the role of electron-vibrational coupling and quantum coherence, to practical guidelines, such as specific suggestions for chemical doping. PMID:26505613

  13. Kinetic pathways leading to layer-by-layer growth from hyperthermal atoms: A multibillion time step molecular dynamics study

    International Nuclear Information System (INIS)

    We employ multibillion time step embedded-atom molecular dynamics simulations to investigate the homoepitaxial growth of Pt(111) from hyperthermal Pt atoms (EPt=0.2-50 eV) using deposition fluxes approaching experimental conditions. Calculated antiphase diffraction intensity oscillations, based on adatom coverages as a function of time, reveal a transition from a three-dimensional multilayer growth mode with EPtPt≥20 eV. We isolate the effects of irradiation-induced processes and thermally activated mass transport during deposition in order to identify the mechanisms responsible for promoting layer-by-layer growth. Direct evidence is provided to show that the observed transition in growth modes is primarily due to irradiation-induced processes which occur during the 10 ps following the arrival of each hyperthermal atom. The kinetic pathways leading to the transition involve both enhanced intralayer and interlayer adatom transport, direct incorporation of energetic atoms into clusters, and cluster disruption leading to increased terrace supersaturation

  14. Shift work, health, the working time regulations and health assessments.

    Science.gov (United States)

    Nicholson, P J; D'Auria, D A

    1999-04-01

    Shift work and night work in particular have been associated with sleep difficulties, general malaise, fatigue, peptic ulceration, ischaemic heart disease, cigarette smoking and adverse pregnancy outcome. The medical conditions previously regarded as making individuals unsuitable for shift work show wide ranging patho-physiological activity and there is no published evidence for any such condition to be regarded an absolute reason to exclude an individual from shift work. The fulfilment of the legal obligations of the Working Time Regulations 1998 is neither prescribed nor constrained in any way. It is advisable therefore to build on existing health procedures where they are in effect. Periodic health questionnaires can offer health professionals an opportunity to detect any disorder likely to be aggravated by shift work or by a combination of shift work, job demands and workplace conditions. A further purpose of the questionnaire is the assessment of ability to undertake shift work duties. However, health questionnaires are neither sensitive nor specific enough to be used to select applicants or employees for shift work, since they do not consistently predict tolerance of shift work or subsequent health problems. Whether employers should offer anything more than a simple questionnaire will depend on the culture of the company and accessibility of health services. Screening programmes affect many people relative to the few who benefit and with existing knowledge, periodic general health examinations performed in asymptomatic subjects have limited predictive or preventive value. PMID:10451593

  15. A real-time assessment of factors influencing medication events.

    Science.gov (United States)

    Dollarhide, Adrian W; Rutledge, Thomas; Weinger, Matthew B; Fisher, Erin Stucky; Jain, Sonia; Wolfson, Tanya; Dresselhaus, Timothy R

    2014-01-01

    Reducing medical error is critical to improving the safety and quality of healthcare. Physician stress, fatigue, and excessive workload are performance-shaping factors (PSFs) that may influence medical events (actual administration errors and near misses), but direct relationships between these factors and patient safety have not been clearly defined. This study assessed the real-time influence of emotional stress, workload, and sleep deprivation on self-reported medication events by physicians in academic hospitals. During an 18-month study period, 185 physician participants working at four university-affiliated teaching hospitals reported medication events using a confidential reporting application on handheld computers. Emotional stress scores, perceived workload, patient case volume, clinical experience, total sleep, and demographic variables were also captured via the handheld computers. Medication event reports (n = 11) were then correlated with these demographic and PSFs. Medication events were associated with 36.1% higher perceived workload (p sleep (p = .10). These results confirm the effect of factors influencing medication events, and support attention to both provider and hospital environmental characteristics for improving patient safety. PMID:23551380

  16. An ecological risk assessment for heavy metals of the lead-zinc ore tailings

    Institute of Scientific and Technical Information of China (English)

    Peng Huibing; Liu Yunguo; Li Jun; Liu Meiying

    2007-01-01

    The structure of Pb,Zn,Cu and Cd in lead zinc ore tailing soils in Yongzhou,Hunan is analyzed by the optimized BCR sequential extraction procedure.The content and proportion of heavy metals of the mine are measured.Meanwhile,the ecological risks are evaluated with the Lars Hakanson's potential ecological risk exponential method.The analysis shows that the content of heavy metals is very high,reaching the level of serious pollution.The order of metal pollution degrees are Cd>Pb>Cu>Zn.On the other hand,it is very possible that the heavy metals may combine together as compounds or cling to the crystal form of clay.Since the form of soluble acid and free metals are very little,it is not an easy job for metal elating or restoration of plants.Yet it is possible to take out those heavy metals adopting the chemical extraction technology.DTPA and EDTA,indicated by a research,both have iterative value and strong conformity effect.So they are effective elutriants to restore the polluted soil.A chemical extraction method is put forward in this paper.

  17. Bone remodeling during pregnancy and post-partum assessed by metal lead levels and isotopic concentrations.

    Science.gov (United States)

    Gulson, Brian; Taylor, Alan; Eisman, John

    2016-08-01

    Bone remodeling is normally evaluated using bone turnover markers/indices as indicators of bone resorption and formation. However, during pregnancy and post-partum, there have been inconsistent results between and within biomarkers for bone formation and resorption. These differences may relate to pregnancy-related changes in metabolism and/or hemodilution altering measured marker levels. An alternative approach to evaluating bone remodeling is to use the metal lead (Pb) concentrations and Pb isotopic compositions in blood. These measurements can also provide information on the amount of Pb that is mobilized from the maternal skeleton. Despite some similarities with accepted bone turnover markers, the Pb data demonstrate increased bone resorption throughout pregnancy that further continues post-partum independent of length of breast-feeding, dietary intake and resumption of menses. Furthermore the isotopic measurements are not affected by hemodilution. These data confirm calcium balance studies that indicate increased bone resorption throughout pregnancy and lactation. They also indicate potentially major public health implications of the transfer of maternal Pb burden to the fetus and new born. PMID:27233973

  18. Lead, nickel and vanadium in seafood: an exposure assessment for Kuwaiti consumers.

    Science.gov (United States)

    Bu-Olayan, A H; al-Yakoob, S

    1998-11-10

    Human exposure to lead (Pb), nickel (Ni) and vanadium (V) through the ingestion of six species of fish and two species of shrimp in Kuwait are determined. The study on seafood consumed by the Kuwaiti residents was analyzed by conducting a survey in five districts of the country, namely, Kuwait city (Capital), Farwaniya, Jahra, Hawaly and Ahmedi. Samples consisting of fish and shrimp were purchased from the local fish market during November 1995 and June 1996. Based on the survey, three major factors were investigated: (i) Pb, Ni and V concentration in the fish of locally consumed fish and shrimp; (ii) daily dietary intake of these elements in humans through consumption of seafood; and (iii) characterizing potential health risks associated with the estimated daily intakes. The risk associated with Pb, Ni and V in seafood was estimated based on a Hazard Index (HI). Although the highest HI (using the 95th percentiles of the daily intake of the element as the dose of concern) was observed for zobaidy, hamoor and shrimp, it is always < 1. This indicated that no serious health threats are associated with oil-related elements in fish and shrimp. PMID:9861729

  19. How many routes lead to migration? Comparison of methods to assess and characterize migratory movements.

    Science.gov (United States)

    Cagnacci, Francesca; Focardi, Stefano; Ghisla, Anne; van Moorter, Bram; Merrill, Evelyn H; Gurarie, Eliezer; Heurich, Marco; Mysterud, Atle; Linnell, John; Panzacchi, Manuela; May, Roel; Nygård, Torgeir; Rolandsen, Christer; Hebblewhite, Mark

    2016-01-01

    Decreasing rate of migration in several species as a consequence of climate change and anthropic pressure, together with increasing evidence of space-use strategies intermediate between residency and complete migration, are very strong motivations to evaluate migration occurrence and features in animal populations. The main goal of this paper was to perform a relative comparison between methods for identifying and characterizing migration at the individual and population level on the basis of animal location data. We classified 104 yearly individual trajectories from five populations of three deer species as migratory or non-migratory, by means of three methods: seasonal home range overlap, spatio-temporal separation of seasonal clusters and the Net Squared Displacement (NSD) method. For migratory cases, we also measured timing and distance of migration and residence time on the summer range. Finally, we compared the classification in migration cases across methods and populations. All methods consistently identified migration at the population level, that is, they coherently distinguished between complete or almost complete migratory populations and partially migratory populations. However, in the latter case, methods coherently classified only about 50% of the single cases, that is they classified differently at the individual-animal level. We therefore infer that the comparison of methods may help point to 'less-stereotyped' cases in the residency-to-migration continuum. For cases consistently classified by all methods, no significant differences were found in migration distance, or residence time on summer ranges. Timing of migration estimated by NSD was earlier than by the other two methods, both for spring and autumn migrations. We suggest three steps to identify improper inferences from migration data and to enhance understanding of intermediate space-use strategies. We recommend (i) classifying migration behaviours using more than one method, (ii

  20. Using oceanic-atmospheric oscillations for long lead-time streamflow forecasting in the Upper Colorado River Basin

    Science.gov (United States)

    Kalra, A.; Ahmad, S.

    2007-12-01

    In the recent past, oceanic-atmospheric oscillations have been used successfully for long lead-time streamflow forecasting. Herein, we present a data-driven model, Support Vector Machine (SVM) for the long lead-time streamflow forecast incorporating oceanic-atmospheric oscillations. The SVM is based on Statistical Learning Theory that uses a hypothesis space of linear functions based on Kernel approach and can be used to predict a quantity forward in time based on training that uses past data. The principal strength of SVM lies in minimizing the empirical classification error and maximizing the geometric margin by solving inverse problems. The SVMs are considered superior to the Artificial Neural Networks (ANNs) due to the tendency of formulating a quadratic optimization problem which ensures a global optimum that is found missing in the traditional ANN approach. The SVM model was applied to four unimpaired gages in the Upper Colorado River Basin (UCRB). The streamflow data for the selected gages was used from 1906¡§C2004. Annual oceanic-atmospheric indexes comprising of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), and El Nino-Southern Oscillations (ENSO) for a period of 1906¡§C2001 were used to generate streamflow volumes for three years ahead. The SVM model was trained with 86 years of data (1906¡§C1991) and tested for 10 years of data (1992-2001). The testing criteria used for the model effectiveness was based on correlation coefficient r, root means square error (RMSE) and nash sutcliffe efficiency coefficient e. Predictions during the testing phase showed a good agreement with measured streamflow volumes for the selected gages in UCRB. Rigorous sensitivity analysis was performed to evaluate the effect of individual oscillation. The results indicated a strong signal for NAO and ENSO indexes as compared to PDO and AMO indexes for the long lead-time streamflow forecast. The oceanic

  1. Picture archiving and communication systems lead to sustained improvements in reporting times and productivity: results of a 5-year audit

    International Nuclear Information System (INIS)

    Aim: To evaluate the impact of picture archiving and communications systems (PACS) on reporting times and productivity in a large teaching hospital. Materials and methods: Reporting time, defined as the time taken from patient registration to report availability, and productivity, defined as the number of reports issued per whole time equivalent (WTE) radiologist per month, were studied for 2 years pre- and 3 years post-PACS installation. Mean reporting time was calculated for plain radiographs and specialist radiology techniques [computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and nuclear medicine]. Productivity, total department workload, and unreported film rates were also assessed. Pre- and post-PACS findings were compared. Results: Between 2002-2006 the number of radiological patient episodes increased by 30% from 11,531/month to 15,057/month. This was accompanied by a smaller increase in WTE reporting radiologists, from 32 to 37 (15%). Mean reporting times have improved substantially post-PACS, plain radiograph reporting time decreased by 26% (from 6.8 to 5 days; p = 0.002) and specialty modalities by 24% (4.1 to 3.1 days; p < 0.001). Radiologist productivity has increased by 18% (337 films to 407 films/WTE radiologist/month). Unreported films have decreased from 5 to 4% for plain radiographs and are steady for specialty modalities (< 1%). In most areas improvements have been sustained over a 3-year period. Conclusion: Since the introduction of PACS, reporting times have decreased by 25% and the productivity improved by 18%. Sustained improvements are felt to reflect the efficiencies and cultural change that accompanied the introduction of PACS and digital dictation

  2. Assessment of environmental distribution of lead in some municipalities of South-Eastern Nigeria.

    Science.gov (United States)

    Nduka, John Kanayochukwu; Orisakwe, Orish Ebere

    2010-06-01

    Lead (Pb) levels were measured in roadside surface soils, dust particles and rain water samples from the urban cities of Enugu, Awka, Onitsha, Nnewi, Aba, Port Harcourt and Warri in Southern Nigeria in 2007 and 2008. Samples were collected during the dry season, while rain water samples were collected during the early rain (April-June), mid rain (July-August) and late rain seasons (September-October) for the two years. Soil samples were collected from traffic congested roads, dust was collected by tying a plastic basin on a pole 1.5 m above ground level and leaving it for 45 days. Rain samples were collected from three equidistant points. Samples were analyzed by AAS. The highest soil Pb of 120.00 +/- 0.00 and 80.36 +/- 0.00 mg/kg were reported in Onitsha for 2007 and 2008, respectively. Nnewi showed 33.40 +/- 0.01 and 4,238.29 +/- 0.00 mg/kg for 2007 and 2008. Aba had 22.56 +/- 0.01 and 21.28 +/- 0.00 mg/kg for 2007 and 2008. Higher concentrations were recorded for Nnewi and Port Harcourt in 2008 than in 2007. Enugu had more in 2007 while Awka had more in 2008. Dust Pb ranged from 0.13-0.49 mg/kg and 0.15-0.47 mg/kg for 2007 and 2008, respectively. Rain samples had the least Pb concentration, ranging from 0.103 +/- 0.000 to 0.163 +/- 0.046 mg/L. We may conclude that Nigerians are exposed to environmental Pb. PMID:20644686

  3. Assessment of Environmental Distribution of Lead in Some Municipalities of South-Eastern Nigeria

    Directory of Open Access Journals (Sweden)

    John Kanayochukwu Nduka

    2010-06-01

    Full Text Available Lead (Pb levels were measured in roadside surface soils, dust particles and rain water samples from the urban cities of Enugu, Awka, Onitsha, Nnewi, Aba, Port Harcourt and Warri in Southern Nigeria in 2007 and 2008. Samples were collected during the dry season, while rain water samples were collected during the early rain (April–June, mid rain (July–August and late rain seasons (September–October for the two years. Soil samples were collected from traffic congested roads, dust was collected by tying a plastic basin on a pole 1.5 m above ground level and leaving it for 45 days. Rain samples were collected from three equidistant points. Samples were analyzed by AAS. The highest soil Pb of 120.00 ± 0.00 and 80.36 ± 0.00 mg/kg were reported in Onitsha for 2007 and 2008, respectively. Nnewi showed 33.40 ± 0.01 and 4,238.29 ± 0.00 mg/kg for 2007 and 2008. Aba had 22.56 ± 0.01 and 21.28 ± 0.00 mg/kg for 2007 and 2008. Higher concentrations were recorded for Nnewi and Port Harcourt in 2008 than in 2007. Enugu had more in 2007 while Awka had more in 2008. Dust Pb ranged from 0.13–0.49 mg/kg and 0.15–0.47 mg/kg for 2007 and 2008, respectively. Rain samples had the least Pb concentration, ranging from 0.103 ± 0.000 to 0.163 ± 0.046 mg/L. We may conclude that Nigerians are exposed to environmental Pb.

  4. Concept and validation studies of the real-time reactor-accident consequences assessment model ECOSYS

    International Nuclear Information System (INIS)

    The Chernobyl accident has demonstrated the urgent need for computer programs for real-time assessment of potential radiological consequences of major reactor accidents and for timely recommendations of useful and cost-efficient counter measures. During the past decade the dynamic radioecological program ECOSYS has been developed for nuclear accident consequence assessment with high resolution in space, time and exposure pathways. The Chernobyl reactor accident leading to relatively high contamination of Southern Germany provided excellent conditions for realistic validation studies of concept, sub-models and parameters of ECOSYS. To this purpose more than 7000 low level and in-situ gamma spectroscopy measurements were performed to study experimentally the behaviour of radionuclides in foodchains and in the urban environment and to compare the results to theoretical predictions of ECOSYS. The results show good agreement in the contamination levels of important food stuffs and in external exposure dose rates from a given surface contamination. Improvements were necessary in the assumptions regarding the food consumption habits which changed considerably - and in the functions describing the weathering off from urban and plant surfaces. The results of this validation study and the concept of the improved computerised model, which has subsequently been converted into a real-time code, are discussed in detail

  5. Real-Time Safety Risk Assessment Based on a Real-Time Location System for Hydropower Construction Sites

    OpenAIRE

    Jiang, Hanchen; Lin, Peng; Fan, Qixiang; Qiang, Maoshan

    2014-01-01

    The concern for workers' safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA) to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge ...

  6. Real-Time Safety Risk Assessment Based on a Real-Time Location System for Hydropower Construction Sites

    OpenAIRE

    Hanchen Jiang; Peng Lin; Qixiang Fan; Maoshan Qiang

    2014-01-01

    The concern for workers’ safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA) to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge ...

  7. Risk Assessment of the Lead intake by consumption of red deer and wild boar meat in Southern Spain

    OpenAIRE

    Sevillano Morales, Jesus; Moreno-Rojas, Rafael; Perez-Rodriguez, Fernando; Arenas Casas, Antonio; Amaro Lopez, Manuel Angel

    2011-01-01

    Abstract The presence of heavy metals in big game meat may pose a risk to human health. The main objective of this work was to carry out a risk assessment study (using a probabilistic and point-estimate approach) of lead intake by consumption of red deer and wild boar meat in Southern Spain based on Spanish data collected in the period 2002-2006. In general, the concentration levels found for wild boar meat (mean= 1291 ?g/Kg) were much higher than those observed in red deer meat (...

  8. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    International Nuclear Information System (INIS)

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne 222Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee's work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of 210Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of 210Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring 210Pb in the heads of former uranium miners has been accomplished

  9. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Laurer, G.R. [New York Univ. Inst. of Environmental Medicine, Tuxedo, NY (United States); Lambert, W.E.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  10. Design of a mixed-oxide fuel assembly to be assessed as a lead test assembly in a BWR reactor

    International Nuclear Information System (INIS)

    The open and the close cycle are the two alternatives to pursue during power generation. The reprocessing is a mature process that now shows a more competitive economic aspect, making it more attractive than ever. Mexico has not decided what to do with the existing and future depleted fuel assemblies that will be generated from the power operation, thus the direct disposal and the reprocessing are still being considered. To have enough arguments in one or the other alternatives it is necessary to make an assessment of both. This investigation focus in the MOX fuel design assuming that the reprocessing is the option to follow and looking for the lowest impact in power generation. The first step in a reprocessing program is to analyze the performance of four lead test assemblies (LTA's), thus in this investigation we design the corresponding MOX to be used as LTA's and assess their performance through one operational cycle. (author)

  11. Assessment of the transmutation capability an accelerator driven system cooled by lead bismuth eutectic alloy

    International Nuclear Information System (INIS)

    1. PURPOSE The reduction of long-lived fission products (LLFP) and minor actinides (MA) is a key point for the public acceptability and economy of nuclear energy. In principle, any nuclear fast reactor is able to burn and transmute MA, but the amount of MA content has to be limited a few percent, having unfavourable consequences on the coolant void reactivity, Doppler effect, and delayed neutron fraction, and therefore on the dynamic behaviour and control. Accelerator Driven Systems (ADS) are instead able to safely burn and/or transmute a large quantity of actinides and LLFP, as they do not rely on delayed neutrons for control or power change and the reactivity feedbacks have very little importance during accidents. Such systems are very innovative being based on the coupling of an accelerator with a subcritical system by means of a target system, where the neutronic source needed to maintain the neutron reaction chain is produced by spallation reactions. To this end the PDS-XADS (Preliminary Design Studies on an experimental Accelerator Driven System) project was funded by the European Community in the 5th Framework Program in order both to demonstrate the feasibility of the coupling between an accelerator and a sub-critical core loaded with standard MOX fuel and to investigate the transmutation capability in order to achieve values suitable for an Industrial Scale Transmuter. This paper summarizes and compares the results of neutronic calculations aimed at evaluating the transmutation capability of cores cooled by Lead-Bismuth Eutectic alloy and loaded with assemblies based on (Pu, Am, Cm) oxide dispersed in a molybdenum metal (CERMET) or magnesia (CERCER) matrices. It also describes the constraints considered in the design of such cores and describes the thermo-mechanical behaviour of these innovative fuels along the cycle. 2. DESCRIPTION OF THE WORK: The U-free composite fuels (CERMET and CERCER) were selected for this study, being considered at European level

  12. Evaluation of Integrated Time-Temperature Effect in Pyrolysis Process of Historically Contaminated Soils with Cadmium (Cd and Lead (Pb

    Directory of Open Access Journals (Sweden)

    Bulmău C

    2013-04-01

    Full Text Available It is already known that heavy metals pollution causes important concern to human and ecosystem health. Heavy metals in soils at the European level represents 37.3% between main contaminates affecting soils (EEA, 2007. This paper illustrates results obtained in the framework of laboratory experiments concerning the evaluation of integrated time-temperature effect in pyrolysis process applied to contaminated soil by two different ways: it is about heavy metals historically contaminated soil from one of the most polluted areas within Romania, and artificially contaminated with PCB-containing transformer oil. In particular, the authors focused on a recent evaluation of pyrolysis efficiency on removing lead (Pb and cadmium (Cd from the contaminated soil. The experimental study evaluated two important parameters related to the studied remediation methodology: thermal process temperature and the retention time in reactor of the contaminated soils. The remediation treatments were performed in a rotary kiln reactor, taking into account three process temperatures (400°C, 600°C and 800°C and two retention times: 30 min. and 60 min. Completed analyses have focused on pyrolysis solids and gas products. Consequently, both ash and gas obtained after pyrolysis process were subjected to chemical analyses.

  13. Role of sintering time, crystalline phases and symmetry in the piezoelectric properties of lead-free KNN-modified ceramics

    International Nuclear Information System (INIS)

    Lead-free KNN-modified piezoceramics of the system (Li,Na,K)(Nb,Ta,Sb)O3 were prepared by conventional solid-state sintering. The X-ray diffraction patterns revealed a perovskite phase, together with some minor secondary phase, which was assigned to K3LiNb6O17, tetragonal tungsten-bronze (TTB). A structural evolution toward a pure tetragonal structure with the increasing sintering time was observed, associated with the decrease of TTB phase. A correlation between higher tetragonality and higher piezoelectric response was clearly evidenced. Contrary to the case of the LiTaO3 modified KNN, very large abnormal grains with TTB structure were not detected. As a consequence, the simultaneous modification by tantalum and antimony seems to induce during sintering a different behaviour from the one of LiTaO3 modified KNN.

  14. A Periodic Review Inventory Model with Controllable Lead Time and Backorder Rate in Fuzzy-stochastic Environment

    Directory of Open Access Journals (Sweden)

    Hardik N. Soni

    2015-03-01

    Full Text Available In this paper, an attempt has been made to develop a periodic review inventory model by considering lead-time and the backorder rate as control variables in fuzzy stochastic environment. Without loss of generality, we have assumed that all the observed values of the fuzzy random variable, representing the demand as triangular fuzzy numbers. The variance of fuzzy random demand is taken into consideration to give due attention to every fuzzy observations. The protection interval demand has also been assumed to be fuzzy stochastic. The expected shortages are calculated by using credibility criterion. For the proposed model, we provide a solution procedure incorporating numerical technique viz. Scan and zoom method to determine an optimal policy. A numerical example is taken up to illustrate the solution procedure and sensitivity analysis of the optimal solution with respect to the key parameters of the system is carried out.

  15. A neuropsychological study of children with elevated dentine lead level: Assessment of the effect of lead in different socio-economic groups

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, O.N.; Trillingsgaard, A.; Beese, I.; Lyngbye, T.; Grandjean, P. (Univ. of Aarhus (Denmark))

    1989-05-01

    The study was carried out in the municipality of Aarhus, a city of 250,000 inhabitants. The study was designed as a cross-sectional cohort study of school children in first grade in 1982-83. A total of 2,412 children were contacted and asked to submit their shed teeth to the teacher, and 1,291 children delivered at least one usable tooth (response rate, 54 percent). The lead level in circumpulpal dentin showed an average of 10.7 micrograms/g. Eight percent of the children (N = 110) had a lead level above 18.7 micrograms/g and were selected as a high lead exposure group. This group was matched by sex and socio-economic status of the parents with control children with a dentin lead level below 5 micrograms/g. Following a detailed interview with the parents, children were excluded from the study if medical risk factors were present. A clinical psychologist, blind to the lead data, administered selected psychometric tests to 162 of the children selected. The high-lead children scored lower on the WISC when compared to low-lead children, especially on the Verbal IQ (p less than 0.001) and Full Scale IQ (p less than 0.01). No significant difference was seen between the high- and low-exposure groups on the Performance IQ and on several experimental tests. Impaired function associated with lead exposure was also found on the Bender Visual Motor Gestalt Test (p less than 0.001) and on a behavioral rating scale (p less than 0.01). These results remained statistically significant even after controlling for socio-economic status and other confounding variables.

  16. Health risk assessment of lead for children in tinfoil manufacturing and e-waste recycling areas of Zhejiang Province, China

    International Nuclear Information System (INIS)

    Tinfoil manufacturing and electronic waste (e-waste) recycling remain rudimentary processes in Zhejing Province, China, which could account for elevated blood lead levels (BLLs) and health impacts on children. We assessed the potential health risks of lead in tinfoil manufacturing and e-waste recycling areas. 329 children in total aged 11–12 who lived in a tinfoil manufacturing area (Lanxi), an e-waste recycling area (Luqiao) and a reference area (Chun'an) were studied. Lead levels in children's blood were determined by inductively coupled plasma mass spectrometer (ICP-MS). Blood urea nitrogen (BUN), serum creatinine, serum calcium, δ-Aminolaevulinic acid (δ-ALA) and intelligence quotient (IQ) were also measured. Geometric mean of BLLs in Lanxi, Luqiao and Chun'an were 8.11 μg/dL, 6.97 μg/dL, and 2.78 μg/dL respectively, with 35.1%, 38.9% and 0% of children who had BLLs above 10 μg/dL. The BLLs in exposed areas were much higher than those in the control area. Lanxi children had higher creatinine and calcium than Chun'an children, and Luqiao children had higher δ-ALA and lower calcium than Chun'an children. No significant differences of IQ were observed between Lanxi, Luqiao and Chun'an, however a negative relationship between BLLs and IQ was shown for the study children. The results indicated that lead pollution from e-waste recycling and tinfoil processing appears to be a potential serious threat to children's health. - Highlights: ► No report on tinfoil processing impact on children's health before. ► Few studies reported health impacts of lead from e-waste processing. ► Children with blood lead levels < 10 μg/dL are associated with a decrease in IQ. ► Threshold appears to exist at blood lead level of about 20 μg/dL for urinary δ-ALA.

  17. Assessment of high power HEV lead-acid battery advancements by comparative benchmarking with a European test procedure

    Science.gov (United States)

    Conte, Mario; Pede, Giovanni; Sglavo, Vincenzo; Macerata, Diego

    The technical and practical suitability of lead-acid batteries for applications in vehicles with electrical drivetrains (battery-powered or hybrid electric) has been experimentally investigated in a variety of testing programmes. Under the direction and funding support of the Commission of the European Community, since early 1990s, the R&D Organisation EUCAR, a collaborative partnership of most European car manufacturers, has been conducting battery technological assessment projects, through bench tests carried out by different independent laboratories throughout Europe, using agreed test procedures. In this framework, ENEA acted as independent testing institute and tested, among others, three high power lead-acid batteries of various technologies (flat plate electrodes and spiral wound) for EV and HEV applications. In addition, different battery sizes and operating conditions have been tested at ENEA in a separate collaboration with ALTRA-IRISBUS. This paper intends to trace technological and performance improvements of high power lead-acid battery technology through the analysis of experimental data during parameter and life cycle tests, including the effects of battery sizes, charge/discharge profiles and testing procedures, with special emphasis on the reduction of the internal resistance and the variation of peak power and cycle life.

  18. The Impact of Weather Forecasts of Various Lead Times on Snowmaking Decisions Made for the 2010 Vancouver Olympic Winter Games

    Science.gov (United States)

    Doyle, Chris

    2014-01-01

    The Vancouver 2010 Winter Olympics were held from 12 to 28 February 2010, and the Paralympic events followed 2 weeks later. During the Games, the weather posed a grave threat to the viability of one venue and created significant complications for the event schedule at others. Forecasts of weather with lead times ranging from minutes to days helped organizers minimize disruptions to sporting events and helped ensure all medal events were successfully completed. Of comparable importance, however, were the scenarios and forecasts of probable weather for the winter in advance of the Games. Forecasts of mild conditions at the time of the Games helped the Games' organizers mitigate what would have been very serious potential consequences for at least one venue. Snowmaking was one strategy employed well in advance of the Games to prepare for the expected conditions. This short study will focus on how operational decisions were made by the Games' organizers on the basis of both climatological and snowmaking forecasts during the pre-Games winter. An attempt will be made to quantify, economically, the value of some of the snowmaking forecasts made for the Games' operators. The results obtained indicate that although the economic value of the snowmaking forecast was difficult to determine, the Games' organizers valued the forecast information greatly. This suggests that further development of probabilistic forecasts for applications like pre-Games snowmaking would be worthwhile.

  19. Model Penjadwalan Pengiriman Pasokan pada Strategi Multi-Supplier dengan Variasi Harga dan Lead Time untuk Permintaan Stokastik

    Directory of Open Access Journals (Sweden)

    Nur Aini Masruroh

    2015-01-01

    Full Text Available Multi-supplier is one of the strategies to minimize holding cost and average stock-out cost as long as to stabilize the supply of raw materials. The common problems that the firms may face when applying the multi-supplier strategy are determining the right schedule and quantity ordered for each supplier. Complexity of the problem increases with the facts that each supplier may have different parameters, demand is uncertain, and the firms’ constraints. Thus, this research is done to answer two main objectives: (1 to determine the optimum safety time (minimum raw material inventory to prevent the stockout due to the demand uncertainty and (2 to determine the right schedule and quantity ordered for each supplier considering the different suppliers parameters: price, lead time, and supply capacity. The problem is modeled in Mixed Integer Linear Programming with total minimum inventory cost as the objective. With the aim of testing the model, a case of multinational company that apply the multi-supplier strategy is used.

  20. Risk Assessment of Non-Carcinogenic Heavy Metals (Barium, Cadmium, and Lead in Hair Color in Markets of Tehran

    Directory of Open Access Journals (Sweden)

    F Khalili

    2016-06-01

    Full Text Available Background and Objectives: Chemical hair color are one of the most widely used cosmetics. The presence of heavy metals in these products can affect the health of consumers. Unlike other cosmetics, no study has been conducted on the heavy metal levels in the synthetic chemical hair colors. This study determined the concentration of heavy metals in these products and the risk assessment of non-carcinogenic effects by these elements were calculated. Material and Method: 32 samples of chemical hair color from eight brands (3 local and 5 imported ones and four most used colors were collected from the markets in Tehran. The concentration of cadmium, lead, and barium was determined using ICP-MS. The information required to assess exposure risk was gathered through  a questionnaire distributed among citizens of Tehran. The assessment of exposure was conducted using Mont Carlo method and  non-carcinogenic risk was determined using the index of Hazard Quotient. . Results: Barium concentration measured was 0.86 mg/kg and concentrations of Cadmium and Lead were 0.45 and 185.34 µg/kg respectively. Among the elements, Pb with Hazard Quotient equals to 7.46×10-4 had the most risk and cadmium with Hazard Quotient equals to 3.57×10-5 had the lowest risk. Moreover, the Iranian brand and blond had the highest risk among the samples. Conclusion: Based on the index of Hazard Quotient, heavy metals in the studied samples had no risk for consumers of these products.

  1. Assessment of Timing Requirements of Phasor Measurement Units

    OpenAIRE

    Singh, Ravi

    2016-01-01

    Accurate time synchronization of Phasor Measurement Unit (PMUs) play an important role in application of synchrophasor technology. Dierent time distribution methods are present which are capable of synchronizing Intelligent Electronic Devices (IEDs) with dierent timing accuracies. Initial part of this report presents information about some of the high-accuracy time distribution methods which were studied and evaluated based on their usability for synchrophasor applications. Later part of the ...

  2. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    Energy Technology Data Exchange (ETDEWEB)

    Fegan, S., E-mail: fegan@ge.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Auffray, E. [CERN, European Organisation for Nuclear Research, Geneva (Switzerland); Battaglieri, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Buchanan, E. [University of Glasgow, Glasgow G12 8QQ (United Kingdom); Caiffi, B.; Celentano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Colaneri, L.; D' Angelo, A. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); De Vita, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Dormenev, V. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); Fanchini, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Lanza, L. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); Novotny, R.W. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); and others

    2015-07-21

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector.

  3. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    International Nuclear Information System (INIS)

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector

  4. A New Target Design with a Beryllium Multiplier for a Lead Slowing Down Time Spectrometer (LSDTS) System

    International Nuclear Information System (INIS)

    In order to quantify fissile isotopes in the spent nuclear fuel or the recycled nuclear material, a lead slowing down time spectrometer (LSDTS) system has been investigated and developed. Among several components of LSDTS, a highly intense neutron should be produced in the system to overcome the background neutrons from spontaneous fission in the curium isotopes. Thus a thin and plate target is designed using tantalum based on the successive reactions such as a bremmstrahlung conversion (e,g) and a photoneutron production (g,n). The beam energy of incident electrons is as high as 35 MeV in LSDTS system, which will decrease in the lead medium after interaction with target. It is known that the higher energy than 5 MeV is enough to produce neutrons for light elements such as beryllium and deuterium Beryllium is widely used as a reflector due to its good characteristics of neutron scattering. Above all, a neutron multiplier is a good choice for beryllium especially in a fusion facility based on the following chain reaction, Be-9 + n (>2MeV) -> 2 He-4 + 2n -1.666 MeV and the cross section is as high as about 580 mb. Using the above application, a beryllium plate is installed on back side of tantalum target in order to multiply neutrons emitting from the target. Furthermore, some sensitivity tests are carried out by changing the thickness of beryllium plate. As a computing tool, MCNPX-2.5 code, a popular Monte Carlo three dimensional code, is taken into consideration

  5. Does Time Matter? Comparing Trajectory Concordance and Covariate Association Using Time-Based and Age-Based Assessments

    Science.gov (United States)

    Piquero, Alex R.; Monahan, Kathryn C.; Glasheen, Cristie; Schubert, Carol A.; Mulvey, Edward P.

    2013-01-01

    Much criminological research has used longitudinal data to assess change in offending over time. An important feature of some data sources is that they contain cross-sections of different aged individuals followed over successive time periods, thereby potentially conflating age and time. This article compares the substantive conclusions about the…

  6. The peer-review system: time for re-assessment?

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Riisgard, H. U.; Quinn, G;

    2000-01-01

    Referees are the backbone of quality control. They need more recognition for their work. In an open exchange of opinions among a number of leading editors and experienced reviewers one suggestion has wide support: It should no longer be 'free' to submit a manuscript to a scientific journal. While...... cash payment for reviews is not considered a good idea, a 'payback in kind' system is favored: i.e., if you want to submit papers to a journal you must be willing to review for that journal.......Referees are the backbone of quality control. They need more recognition for their work. In an open exchange of opinions among a number of leading editors and experienced reviewers one suggestion has wide support: It should no longer be 'free' to submit a manuscript to a scientific journal. While...

  7. Direct look from a predator shortens the risk-assessment time by prey.

    Directory of Open Access Journals (Sweden)

    Sang-im Lee

    Full Text Available Decision making process is an important component of information use by animals and has already been studied in natural situations. Decision making takes time, which is expressed as a cost in evolutionary explanations of decision making abilities of animals. However, the duration of information assessment and decision making process has not been measured in a natural situation. Here, we use responses of wild magpies (Pica pica to predictably approaching humans to demonstrate that, regardless of whether the bird perceived high (decided to fly away or low (resumed foraging threat level, the bird assessed the situation faster when approaching humans looked directly at it than when the humans were not directly looking at it. This indicates that prey is able to extract more information about the predator's intentions and to respond sooner when the predator is continuously ("intently" looking at the prey. The results generally illustrate how an increase of information available to an individual leads to a shorter assessment and decision making process, confirming one of central tenets of psychology of information use in a wild bird species in its natural habitat.

  8. Assessing Time-Varying Causal Effect Moderation in Mobile Health

    OpenAIRE

    Boruvka, Audrey; Almirall, Daniel; Witkiewitz, Katie; Murphy, Susan A.

    2016-01-01

    In mobile health interventions aimed at behavior change and maintenance, treatments are provided in real time to manage current or impending high risk situations or promote healthy behaviors in near real time. Currently there is great scientific interest in developing data analysis approaches to guide the development of mobile interventions. In particular data from mobile health studies might be used to examine effect moderators-i.e., individual characteristics, time-varying context or past t...

  9. Health risk assessment of various metal(loid)s via multiple exposure pathways on children living near a typical lead-acid battery plant, China

    International Nuclear Information System (INIS)

    Manufacture of lead-acid batteries is of widespread interest because of its emissions of heavy metals and metalloids into environment, harming environmental quality and consequently causing detrimental effects on human health. In this study, exposure pathways and health risks of children to heavy metal(loid)s (Pb, Cd, As, etc) were investigated based on field sampling and questionnaire. Pb was one of the most abundant elements in children's blood, with an elevated blood lead level of 12.45 μg dL−1. Soil/dust and food were heavily polluted by targeted metal(loid)s. Food ingestion accounted for more than 80% of the total exposure for most metal(loid)s. The non-cancer risks to children were 3–10 times higher than the acceptable level of 1, while the cancer risks were 5–200 times higher than the maximum acceptable level of 1.0 × 10−4. The study emphasized the significance of effective environmental management, particularly to ensure food security near battery facilities. - Highlights: • The health risks of children living around a typical lead-acid battery was analyzed. • The exposure pathways of children to 12 heavy metal(loid)s were assessed. • Courtyard soil and indoor dust and duplicate food were contaminated by metal(loid)s. • Food ingestion was the major pathway for children's exposure to most metal(loid)s. • Higher potentially non-cancer and cancer risks happened to the local children. - The children living around a typical lead-acid battery plant suffered from serious health risks, which mainly attributed to food ingestion and air inhalation exposure

  10. Anxiety in Asperger's Syndrome: Assessment in Real Time

    Science.gov (United States)

    Hare, Dougal J.; Wood, Christopher; Wastell, Sarah; Skirrow, Paul

    2015-01-01

    Anxiety is a major problem for many people with Asperger's syndrome who may have qualitatively different fears from a non-Asperger's syndrome population. Research has relied on measures developed for non-Asperger's syndrome populations that require reporting past experiences of anxiety, which may confound assessment in people with Asperger's…

  11. Real time analysis of lead-containing atmospheric particles in Beijing during springtime by single particle aerosol mass spectrometry.

    Science.gov (United States)

    Ma, Li; Li, Mei; Huang, Zhengxu; Li, Lei; Gao, Wei; Nian, Huiqing; Zou, Lilin; Fu, Zhong; Gao, Jian; Chai, Fahe; Zhou, Zhen

    2016-07-01

    Using a single particle aerosol mass spectrometer (SPAMS), the chemical composition and size distributions of lead (Pb)-containing particles with diameter from 0.1 μm to 2.0 μm in Beijing were analyzed in the spring of 2011 during clear, hazy, and dusty days. Based on mass spectral features of particles, cluster analysis was applied to Pb-containing particles, and six major classes were acquired consisting of K-rich, carboneous, Fe-rich, dust, Pb-rich, and Cl-rich particles. Pb-containing particles accounted for 4.2-5.3%, 21.8-22.7%, and 3.2% of total particle number during clear, hazy and dusty days, respectively. K-rich particles are a major contribution to Pb-containing particles, varying from 30.8% to 82.1% of total number of Pb-containing particles, lowest during dusty days and highest during hazy days. The results reflect that the chemical composition and amount of Pb-containing particles has been affected by meteorological conditions as well as the emissions of natural and anthropogenic sources. K-rich particles and carbonaceous particles could be mainly assigned to the emissions of coal combustion. Other classes of Pb-containing particles may be associated with metallurgical processes, coal combustion, dust, and waste incineration etc. In addition, Pb-containing particles during dusty days were first time studied by SPAMS. This method could provide a powerful tool for monitoring and controlling of Pb pollution in real time. PMID:27085059

  12. Assessing the Predictability of Scheduled-Vehicle Travel Times

    DEFF Research Database (Denmark)

    Tiesyte, Dalia; Jensen, Christian Søndergaard

    2009-01-01

    One of the most desired and challenging services in collective transport systems is the real-time prediction of the near-future travel times of scheduled vehicles, especially public buses, thus improving the experience of the transportation users, who may be able to better schedule their travel......, and also enabling system operators to perform real-time monitoring. While travel-time prediction has been researched extensively during the past decade, the accuracies of existing techniques fall short of what is desired, and proposed mathematical prediction models are often not transferable to other...... systems because the properties of the travel-time-related data of vehicles are highly context-dependent, making the models difficult to fit. We propose a framework for evaluating various predictability types of the data independently of the model, and we also compare predictability analysis results of...

  13. Analisis Penerapan Lean Production Process untuk Mengurangi Lead Time Process Perawatan Engine (Studi Kasus PT.GMF AEROASIA

    Directory of Open Access Journals (Sweden)

    Wahyu Adrianto

    2016-04-01

     Engine maintenance berusaha untuk selalu meningkatkan keunggulanlayanannya dengan tools berupa gate system dimana sistem tersebut diharapkandapat merealisasikan lead time selama 60 hari. Dalam implementasinya gatesystem tersebut masih belum dapat memenuhi target yang diharapkan. Selamaproses maintenance atau overhaul engine masih ditemui pemborosan atau wasteyang menyebabkan target tidak dapat terpenuhi. Lean Manufacturing merupakanpendekatan yang bertujuan untuk meminimasi pemborosan yang terjadi pada aliranproses. Pemahaman kondisi dari proses digambarkan dalam Value Stream Mappinguntuk selanjutnya dijabarkan aktivitas yang memiliki nilai tambah dan tidakmemiliki nilai tambah. Melalui seven waste concept, kemudian dilakukanpembobotan untuk mengetahui jenis waste yang paling dominan.Dari hasil pengolahan dalam Value Stream Mapping diketahui gate 1 dan gate 3merupakan titik yang banyak terdapat waste. Pembobotan dan pemeringkatanseven waste yang ada dalam aktivitas proses diperoleh hasil berupa urutan criticalwaste dari ketujuh waste yang ada. Bobot tertinggi yaitu pada jenis waste waitingdengan bobot sebesar 0.38. Hasil dari Root Cause Analysis diketahui bahwa akar penyebab dari waste waiting yaitu data yang tidak di-maintain, kurangnyaperhatian terhadap people development, Masih ditemukan adanya Bug pada sistempendukung proses dan adanya miskomunikasi antar bagian di engine maintenance. Kata kunci: lean, waste, value added, proses

  14. Exposición al plomo y su relación con el tiempo requerido para embarazo Lead exposure and time to pregnancy

    Directory of Open Access Journals (Sweden)

    Juan Luis Guerra-Tamayo

    2003-01-01

    .OBJECTIVE: To determine the effects of lead exposure on the time elapsed to become pregnant. MATERIAL AND METHODS: The study population consisted of 142 women residing in Mexico City between 1997 and 2001, who were already participating in a study to evaluate effects of lead exposure on reproductive health. Measurements of lead in bone were performed when women were first admitted to the program. Information on lead exposure and other variables of interest was obtained through a questionnaire. Participants were followed up to assess the relationship between the time required to become pregnant and lead exposure. Statistical analysis consisted of Kaplan-Meier estimates and Cox proportional hazards models. RESULTS: Of the total number of women in the program, 42 got pregnant: 34 before the first year of follow-up, and 8 at a later date. The mean value for lead concentration in blood was 9.3 µg/dl. The mean values for lead concentration in patella and tibia were 16.0 y 11.0 µg Pb/g of bone, respectively. Survival analysis was performed and no differences were detected in blood lead levels and time to pregnancy in the first year. Nevertheless, in women with blood lead levels above 10.0 µg/dl, the likelihood of not achieving pregnancy was five times higher (95% confidence interval [CI] 0.05-0.56 after one year of follow-up compared with women with blood lead levels below 10.0 µg/dl. CONCLUSIONS: Exposure to high lead concentrations may be an important risk factor influencing the time period for a woman to get pregnant, especially in fertile women who have tried to get pregnant for more than a year.

  15. Innovative real time simulation training and nuclear probabilistic risk assessment

    International Nuclear Information System (INIS)

    Operator errors have been an area of public concern for the safe operation of nuclear power plants since the TMI2 incident. Simply stated, nuclear plants are very complex systems and the public is skeptical of the operators' ability to comprehend and deal with the vast indications and complexities of potential nuclear power plant events. Prior to the TMI2 incident, operator errors and human factors were not included as contributing factors in the Probabilistic Risk Assessment (PRA) studies of nuclear power plant accidents. More recent efforts in nuclear risk assessment have addressed some of the human factors affecting safe nuclear plant operations. One study found four major factors having significant impact on operator effectiveness. This paper discusses human factor PRAs, new applications in simulation training and the specific potential benefits from simulation in promoting safer operation of future power plants as well as current operating power plants

  16. Combination of didactic lectures and review sessions in endocrinology leads to improvement in student performance as measured by assessments.

    Science.gov (United States)

    Qureshi, Ayisha; Cozine, Cassy; Rizvi, Farwa

    2013-03-01

    There can be no single best way of learning, and each teaching mode has its own merits and demerits. Didactic lectures in and of themselves are insufficient, whereas a problem-based tutorial alone can be as ineffective. This study was conducted to determine if a problem-based review after didactic lectures would lead to better student performance. To compare performance, the same student group was taught three units of endocrinology (growth hormone, thyroid hormone, and diabetes). Students were divided into the following three groups: diabetes didactic lectures only, growth hormone didactic lectures plus review, and thyroid hormone didactic lectures plus review. All three topics were covered in the didactic lectures, but only growth hormone and thyroid hormone topics were covered in the review session. At the end of the course, all students were given formative assessments in the form of multiple-choice questions. A highly significant increase (P < 0.000) in the percentage of correct responses on the questions covering growth hormone (mean: 0.838, SD: 0.158) and thyroid hormone (mean: 0.686, SD: 0.232) compared with diabetes (mean: 0.478, SD: 0.259) was observed. In conclusion, this study provides further evidence that the combination of didactic lectures and an active review session leads to an improvement in student performance. PMID:23471255

  17. Time is no healer: increasing restoration age does not lead to improved benthic invertebrate communities in restored river reaches.

    Science.gov (United States)

    Leps, Moritz; Sundermann, Andrea; Tonkin, Jonathan D; Lorenz, Armin W; Haase, Peter

    2016-07-01

    Evidence for successful restoration of riverine communities is scarce, particularly for benthic invertebrates. Among the multitude of reasons discussed so far for the lack of observed effects is too short of a time span between implementation and monitoring. Yet, studies that explicitly focus on the importance of restoration age are rare. We present a comprehensive study based on 44 river restoration projects in Germany, focusing on standardized benthic invertebrate sampling. A broad gradient ranging from 1 to 25years in restoration age was available. In contrast to clear improvements in habitat heterogeneity, benthic community responses to restoration were inconsistent when compared to control sections. Taxon richness increased in response to restoration, but abundance, diversity and various assessment metrics did not respond clearly. Restoration age was a poor predictor of community composition and community change, as no significant linear responses could be detected using 34 metrics. Moreover, only 5 out of 34 tested metrics showed non-linear shifts at restoration ages of 2 to 3years. This might be interpreted as an indication of a post-restoration disturbance followed by a re-establishment of pre-restoration conditions. BIO-ENV analysis and fourth-corner modeling underlined the low importance of restoration age, but revealed high importance of catchment-scale characteristics (e.g., ecoregion, catchment size and land use) in controlling community composition and community change. Overall, a lack of time for community development did not appear to be the ultimate reason for impaired benthic invertebrate communities. Instead, catchment-scale characteristics override the effectiveness of restoration. To enhance the ecological success of future river restoration projects, we recommend improving water quality conditions and catchment-scale processes (e.g., connectivity and hydrodynamics) in addition to restoring local habitat structure. PMID:27046138

  18. Development of a real-time radiological dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Han, Moon Hee; Lee, Young Bok; Kim, Eun Han; Suh, Kyung Suk; Hwang, Won Tae

    1997-01-01

    Inspection and repair of tower structure and lift, instrument calibration have been done. Wireless data transmission to MIPS (Meteorological Information Processing System) has been done after collection in the DAS where environmental assessment can be done by the developed simulation programs in both cases of normal operation and emergency. Wind direction, wind speed, temperature, humidity at 67m, 27m, and 10m height and temperature, humidity, atmospheric pressure, solar radiation, precipitation, and visibility at surface have been measured analyzed with statistical methods. At the site, the prevailing wind directions were SW in spring and summer, NNW in winter season. (author). 6 refs., 9 tabs., 4 figs.

  19. Development of a real-time radiological dose assessment system

    International Nuclear Information System (INIS)

    Inspection and repair of tower structure and lift, instrument calibration have been done. Wireless data transmission to MIPS (Meteorological Information Processing System) has been done after collection in the DAS where environmental assessment can be done by the developed simulation programs in both cases of normal operation and emergency. Wind direction, wind speed, temperature, humidity at 67m, 27m, and 10m height and temperature, humidity, atmospheric pressure, solar radiation, precipitation, and visibility at surface have been measured analyzed with statistical methods. At the site, the prevailing wind directions were SW in spring and summer, NNW in winter season. (author). 6 refs., 9 tabs., 4 figs

  20. A screening-level assessment of lead, cadmium, and zinc in fish and crayfish from Northeastern Oklahoma, USA.

    Science.gov (United States)

    Schmitt, Christopher J; Brumbaugh, William G; Linder, Gregory L; Hinck, Jo Ellen

    2006-10-01

    The objective of this study was to evaluate potential human and ecological risks associated with metals in fish and crayfish from mining in the Tri-States Mining District (TSMD). Crayfish (Orconectes spp.) and fish of six frequently consumed species (common carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; flathead catfish, Pylodictis olivaris; largemouth bass, Micropterus salmoides; spotted bass, M. punctulatus; and white crappie, Pomoxis annularis) were collected in 2001--2002 from the Oklahoma waters of the Spring River (SR) and Neosho River (NR), which drain the TSMD. Samples from a mining-contaminated site in eastern Missouri and from reference sites were also analyzed. Individual fish were prepared for human consumption in the manner used locally by Native Americans (headed, eviscerated, and scaled) and analyzed for lead, cadmium, and zinc. Whole crayfish were analyzed as composite samples of 5--60 animals. Metals concentrations were typically higher in samples from sites most heavily affected by mining and lowest in reference samples. Within the TSMD, most metals concentrations were higher at sites on the SR than on the NR and were typically highest in common carp and crayfish than in other taxa. Higher concentrations and greater risk were associated with fish and crayfish from heavily contaminated SR tributaries than the SR or NR mainstems. Based on the results of this and previous studies, the human consumption of carp and crayfish could be restricted based on current criteria for lead, cadmium, and zinc, and the consumption of channel catfish could be restricted due to lead. Metals concentrations were uniformly low in Micropterus spp. and crappie and would not warrant restriction, however. Some risk to carnivorous avian wildlife from lead and zinc in TSMD fish and invertebrates was also indicated, as was risk to the fish themselves. Overall, the wildlife assessment is consistent with previously reported biological effects attributed to metals

  1. Assessing Pneumonia Identification from Time-Ordered Narrative Reports

    Science.gov (United States)

    Bejan, Cosmin A.; Vanderwende, Lucy; Wurfel, Mark M.; Yetisgen-Yildiz, Meliha

    2012-01-01

    In this paper, we present a natural language processing system that can be used in hospital surveillance applications with the purpose of identifying patients with pneumonia. For this purpose, we built a sequence of supervised classifiers, where the dataset corresponding to each classifier consists of a restricted set of time-ordered narrative reports. In this way the pneumonia surveillance application will be able to invoke the most suitable classifier for each patient based on the period of time that has elapsed since the patient was admitted into the hospital. Our system achieves significantly better results when compared with a baseline previously proposed for pneumonia identification. PMID:23304388

  2. Assessment of Driver's Reaction Times in Diverisified Research Environments

    Science.gov (United States)

    Guzek, Marek; Lozia, Zbigniew; Zdanowicz, Piotr; Jurecki, Rafał S.; Stańczyk, Tomasz L.; Pieniążek, Wiesław

    2012-06-01

    Reaction time is one of the basic parameters that characterize the driver and very important in the analysis of accident situations in road traffic. This paper describes research studies on the reaction time evaluation as conducted in three environments: on a typical device used in the transport psychology labs (the so-called reflexometer), in the driving simulator (autoPW) and on the driving test track (the Kielce Test Track). In all environments, the tests were performed for the same group of drivers. The article presents the characteristics of research in each environment as well as shows and compares exemplary results.

  3. Misplaced Inventory and Lead-Time in the Supply Chain: Analysis of Decision-Making on RFID Investment with Service Level

    OpenAIRE

    Li-Hao Zhang; Ti-Jun Fan; Wen-Chyuan Chiang; Feng Tao

    2014-01-01

    Radio-frequency identification (RFID), as the key technology of Internet of Things (IoT), has been hailed as a major innovation to solve misplaced inventory and reduce lead-time. Many retailers have been pushing their suppliers to invest this technology. However, its associated costs seem to prohibit its widespread application. This paper analyzes the situation of service level in a retail supply chain, which has resulted from misplaced inventory and lead-time. By newsvendor model, we analyze...

  4. Distribution-Free Continuous Review Inventory Model with Controllable Lead Time and Setup Cost in the Presence of a Service Level Constraint

    OpenAIRE

    Wei-Min MA; QIU, Bing-Bing

    2012-01-01

    Based on the mean and the standard deviation of lead time demand, and also taking the difficulty in measuring shortage cost into consideration, we investigate the joint decision problem of continuous review inventory in which a service level constraint should be satisfied. Under the assumption of controllable lead time and setup cost, a mathematical programming model is established. The objective function of the proposed model is the total expected annual cost and the constraint guarantees th...

  5. Interaction Patterns of Premarital Couples: Typological Assessment Over Time.

    Science.gov (United States)

    Norem, Rosalie H.; Olson, David H.

    1983-01-01

    Studied interaction styles of premarital couples (N=148) and developed a typology of couple interaction at two points in time before marriage. Results showed only 7 percent of the couples had the same type of interaction at the two testings, supporting the hypothesis that premarital relationships are fluid. (WAS)

  6. Probabilistic Health Risk Assessment of Chemical Mixtures: Importance of Travel Times and Connectivity

    Science.gov (United States)

    Henri, Christopher V.; Fernàndez-Garcia, Daniel; de Barros, Felipe P. J.

    2014-05-01

    Subsurface contamination cases giving rise to groundwater pollutions are extensively found in all industrialized countries. Under this pressure, risk assessment methods play an important role in population protection by (1) quantifying the potential impact on human health of an aquifer contamination and (2) helping and driving decisions of groundwater-resource managers. Many reactive components such as chlorinated solvents or nitrates potentially experience attenuation processes under common geochemical conditions. This represents an attractive and extensively used remediation solution but leads often to the production of by-products before to reach a harmless chemical form. This renders mixtures of contaminants a common issue for groundwater resources managers. In this case, the threat posed by these contaminants to human health at a given sensitive location greatly depends on the competition between reactive and advective-dispersive characteristic times. However, hydraulic properties of the aquifer are known to be spatially variable, which can lead to the formation of preferential flow channels and fast contamination pathways. Therefore, the uncertainty on the spatial distribution of the aquifer properties controlling the plume travel time may then play a particular role in the human health risk assessment of chemical mixtures. We investigate here the risk related to a multispecies system in response to different degrees of heterogeneity of the hydraulic conductivity (K or Y =ln(K)). This work focuses on a Perchloroethylene (PCE) contamination problem followed by the sequential first-order production/biodegradation of its daughter species Trichloroethylene (TCE), Dichloroethylene (DCE) and Vinyl Chlorine (VC). For this specific case, VC is known to be a highly toxic contaminant. By performing numerical experiments, we evaluate transport through three-dimensional mildly (σY 2=1.0) and highly (σY 2=4.0) heterogeneous aquifers. Uncertainty on the hydraulic

  7. Assessing spatial covariance among time series of abundance.

    Science.gov (United States)

    Jorgensen, Jeffrey C; Ward, Eric J; Scheuerell, Mark D; Zabel, Richard W

    2016-04-01

    For species of conservation concern, an essential part of the recovery planning process is identifying discrete population units and their location with respect to one another. A common feature among geographically proximate populations is that the number of organisms tends to covary through time as a consequence of similar responses to exogenous influences. In turn, high covariation among populations can threaten the persistence of the larger metapopulation. Historically, explorations of the covariance in population size of species with many (>10) time series have been computationally difficult. Here, we illustrate how dynamic factor analysis (DFA) can be used to characterize diversity among time series of population abundances and the degree to which all populations can be represented by a few common signals. Our application focuses on anadromous Chinook salmon (Oncorhynchus tshawytscha), a species listed under the US Endangered Species Act, that is impacted by a variety of natural and anthropogenic factors. Specifically, we fit DFA models to 24 time series of population abundance and used model selection to identify the minimum number of latent variables that explained the most temporal variation after accounting for the effects of environmental covariates. We found support for grouping the time series according to 5 common latent variables. The top model included two covariates: the Pacific Decadal Oscillation in spring and summer. The assignment of populations to the latent variables matched the currently established population structure at a broad spatial scale. At a finer scale, there was more population grouping complexity. Some relatively distant populations were grouped together, and some relatively close populations - considered to be more aligned with each other - were more associated with populations further away. These coarse- and fine-grained examinations of spatial structure are important because they reveal different structural patterns not evident

  8. An assessment of unstructured grid technology for timely CFD analysis

    Science.gov (United States)

    Kinard, Tom A.; Schabowski, Deanne M.

    1995-01-01

    An assessment of two unstructured methods is presented in this paper. A tetrahedral unstructured method USM3D, developed at NASA Langley Research Center is compared to a Cartesian unstructured method, SPLITFLOW, developed at Lockheed Fort Worth Company. USM3D is an upwind finite volume solver that accepts grids generated primarily from the Vgrid grid generator. SPLITFLOW combines an unstructured grid generator with an implicit flow solver in one package. Both methods are exercised on three test cases, a wing, and a wing body, and a fully expanded nozzle. The results for the first two runs are included here and compared to the structured grid method TEAM and to available test data. On each test case, the set up procedure are described, including any difficulties that were encountered. Detailed descriptions of the solvers are not included in this paper.

  9. Assessing Change in High School Student Information Literacy Using the Tool for Real-Time Assessment of Information Literacy Skills

    Science.gov (United States)

    Kovalik, Cindy L.; Yutzey, Susan D.; Piazza, Laura M.

    2012-01-01

    Change in high school student information literacy (IL) knowledge and skills, from freshman year to senior year in high school was the focus of this quasi-experimental research project. Researchers used a free information literacy skills assessment tool entitled TRAILS (Tool for Real-time Assessment of Information Literacy Skills) to measure…

  10. Assessing Pneumonia Identification from Time-Ordered Narrative Reports

    OpenAIRE

    Bejan, Cosmin A.; Vanderwende, Lucy; Wurfel, Mark M.; Yetisgen-Yildiz, Meliha

    2012-01-01

    In this paper, we present a natural language processing system that can be used in hospital surveillance applications with the purpose of identifying patients with pneumonia. For this purpose, we built a sequence of supervised classifiers, where the dataset corresponding to each classifier consists of a restricted set of time-ordered narrative reports. In this way the pneumonia surveillance application will be able to invoke the most suitable classifier for each patient based on the period of...

  11. Associations of objectively assessed physical activity and sedantary time

    OpenAIRE

    Daniela Schmid; Cristian Ricci; Leitzmann, Michael F

    2015-01-01

    Background Sedentary behavior is related to increased mortality risk. Whether such elevated risk can be offset by enhanced physical activity has not been examined using accelerometry data. Materials and Methods We examined the relations of sedentary time and physical activity to mortality from any cause using accelerometry data among 1,677 women and men aged 50 years or older from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 cycle with follow-up through De...

  12. Bronchoscopic assessment of airway retention time of aerosolized xylitol

    OpenAIRE

    Kearney William R; Allaman Margaret M; Watt Janet L; Launspach Janice; Neelakantan Srividya; Durairaj Lakshmi; Veng-Pedersen Peter; Zabner Joseph

    2006-01-01

    Abstract Background Human airway surface liquid (ASL) has abundant antimicrobial peptides whose potency increases as the salt concentration decreases. Xylitol is a 5-carbon sugar that has the ability to lower ASL salt concentration, potentially enhancing innate immunity. Xylitol was detected for 8 hours in the ASL after application in airway epithelium in vitro. We tested the airway retention time of aerosolized iso-osmotic xylitol in healthy volunteers. Methods After a screening spirometry, ...

  13. Real-time non-invasive assessment of human hematocrit

    Science.gov (United States)

    Duncan, Donald D.; Fischer, David G.; Myers, Jerry G.

    2012-03-01

    An important indicator of health status is hematocrit (HCT), the fractional volume of red blood cells. As such, a noninvasive, real-time means of its measurement is highly desirable in a space flight situation. We propose to exploit ultrasound technology to provide such a capability. We introduce a specific measurement concept including the hardware and requisite processing algorithms, and discuss progress towards realization of such a measurement capability.

  14. Threshold exceedance risk assessment in complex space-time systems

    Science.gov (United States)

    Angulo, José M.; Madrid, Ana E.; Romero, José L.

    2015-04-01

    Environmental and health impact risk assessment studies most often involve analysis and characterization of complex spatio-temporal dynamics. Recent developments in this context are addressed, among other objectives, to proper representation of structural heterogeneities, heavy-tailed processes, long-range dependence, intermittency, scaling behavior, etc. Extremal behaviour related to spatial threshold exceedances can be described in terms of geometrical characteristics and distribution patterns of excursion sets, which are the basis for construction of risk-related quantities, such as in the case of evolutionary study of 'hotspots' and long-term indicators of occurrence of extremal episodes. Derivation of flexible techniques, suitable for both the application under general conditions and the interpretation on singularities, is important for practice. Modern risk theory, a developing discipline motivated by the need to establish solid general mathematical-probabilistic foundations for rigorous definition and characterization of risk measures, has led to the introduction of a variety of classes and families, ranging from some conceptually inspired by specific fields of applications, to some intended to provide generality and flexibility to risk analysts under parametric specifications, etc. Quantile-based risk measures, such as Value-at-Risk (VaR), Average Value-at-Risk (AVaR), and generalization to spectral measures, are of particular interest for assessment under very general conditions. In this work, we study the application of quantile-based risk measures in the spatio-temporal context in relation to certain geometrical characteristics of spatial threshold exceedance sets. In particular, we establish a closed-form relationship between VaR, AVaR, and the expected value of threshold exceedance areas and excess volumes. Conditional simulation allows us, by means of empirical global and local spatial cumulative distributions, the derivation of various statistics of

  15. Lead exposure at uncovered outdoor firing ranges

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, R.L.; Hicks, A.M.; O' Leary, L.M.; London, S. (University of Southern California School of Medicine, Los Angeles (USA))

    1991-06-01

    Excessive lead exposure in shooting instructors at indoor firing ranges and covered outdoor firing ranges has been documented. The City of Los Angeles assessed exposure of its full-time shooting instructors at uncovered outdoor ranges via air monitoring and blood lead-level measurements. Results of these tests revealed that significant lead exposure and absorption can occur at outdoor firing ranges. The use of copper-jacketed ammunition may decrease air lead levels and decrease lead absorption by range instructors.

  16. Bronchoscopic assessment of airway retention time of aerosolized xylitol

    Directory of Open Access Journals (Sweden)

    Kearney William R

    2006-02-01

    Full Text Available Abstract Background Human airway surface liquid (ASL has abundant antimicrobial peptides whose potency increases as the salt concentration decreases. Xylitol is a 5-carbon sugar that has the ability to lower ASL salt concentration, potentially enhancing innate immunity. Xylitol was detected for 8 hours in the ASL after application in airway epithelium in vitro. We tested the airway retention time of aerosolized iso-osmotic xylitol in healthy volunteers. Methods After a screening spirometry, volunteers received 10 ml of nebulized 5% xylitol. Bronchoscopy was done at 20 minutes (n = 6, 90 minutes (n = 6, and 3 hours (n = 5 after nebulization and ASL was collected using microsampling probes, followed by bronchoalveolar lavage (BAL. Xylitol concentration was measured by nuclear magnetic resonance spectroscopy and corrected for dilution using urea concentration. Results All subjects tolerated nebulization and bronchoscopy well. Mean ASL volume recovered from the probes was 49 ± 23 μl. The mean ASL xylitol concentration at 20, 90, and 180 minutes was 1.6 ± 1.9 μg/μl, 0.6 ± 0.6 μg/μl, and 0.1 ± 0.1 μg/μl, respectively. Corresponding BAL concentration corrected for dilution was consistently lower at all time points. The terminal half-life of aerosolized xylitol obtained by the probes was 45 minutes with a mean residence time of 65 minutes in ASL. Corresponding BAL values were 36 and 50 minutes, respectively. Conclusion After a single dose nebulization, xylitol was detected in ASL for 3 hours, which was shorter than our in vitro measurement. The microsampling probe performed superior to BAL when sampling bronchial ASL.

  17. The Tenebrionidae of California: A Time Sensitive Snapshot Assessment

    Directory of Open Access Journals (Sweden)

    Rolf Aalbu

    2014-06-01

    Full Text Available Due to a diversity of habitats and its geologic history, the US state of California hosts a spectacular assemblage of darkling beetle species (Coleoptera: Tenebrionidae. In addition to being part of the California Floristic Province, one of 34 global biodiversity hotspots identified by Conservation International, California also has additional areas which are parts of the Great Basin, Mojave, and Sonoran deserts. California is divided into nine floristic regions. Each region is assessed in terms of faunal composition and endemism. A “snapshot” of our present knowledge of the Tenebrionidae indicates that 447 currently recognized species, representing 108 genera, occur in California of which one hundred and ninety are endemic. California is compared to other nearby regions in diversity and endemism. An analysis of currently valid species vs a more realistic species account based on unpublished records of likely synonyms and known species yet to be described in the scientific literature is presented. The California Floristic Region, rather than other more arid parts of California, has the highest number of total and endemic species. Because of their high diversity and endemism, tenebrionids could potentially provide a valuable tool for monitoring the environment for conservation purposes.

  18. Nonlinear Time Reversal Acoustic Method of Friction Stir Weld Assessment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of the project is demonstration of the feasibility of Friction Stir Weld (FSW) assessment by novel Nonlinear Time Reversal Acoustic (TRA) method. Time...

  19. A Thailand case study based on quantitative assessment: does a national lead agency make a difference in pre-hospital care development in middle income countries?

    OpenAIRE

    Suriyawongpaisal, Paibul; Aekplakorn, Wichai; Tansirisithikul, Rassamee

    2014-01-01

    Background Emergency Medical Institute of Thailand (EMIT) has been established as a national lead agency to improve emergency medical service systems since December 2008. However up to now, there has not been any published systematic assessment of its performance to guide further policy decisions. Methods This study assesses the 4-year pre-hospital care coverage and performance in Thailand after EMIT establishment. The assessment makes use of 1,171,564 records from a national data set for pre...

  20. Assessment of bacterial communities and characterization of lead-resistant bacteria in the rhizosphere soils of metal-tolerant Chenopodium ambrosioides grown on lead-zinc mine tailings.

    Science.gov (United States)

    Zhang, Wen-hui; Huang, Zhi; He, Lin-yan; Sheng, Xia-fang

    2012-06-01

    Bacterial communities in the rhizosphere soils of metal tolerant and accumulating Chenopodium ambrosioides grown in highly and moderately lead-zinc mine tailings contaminated-soils as well as the adjacent soils with low metal contamination were characterized by using cultivation-independent and cultivation techniques. A total of 69, 73, and 83 bacterial operational taxonomic units (OTUs) having 84.8-100% similarity with the closest match in the database were detected among high, moderate, and low-contamination soil clone libraries, respectively. These OTUs had a Shannon diversity index value in the range of 4.06-4.30. There were 9, 10, and 14 bacterial genera specific to high, moderate, and low metal-contaminated soil clone libraries, respectively. Phylogenetic analysis showed that the Pb-resistant isolates belonged to 8 genera. Pseudomonas and Arthrobacter were predominant among the isolates. Most of the isolates (82-86%) produced indole acetic acid and siderophores. More strains from the highly metal-contaminated soil produced 1-aminocyclopropane-1-carboxylate deaminase than the strains from the moderately and lowly metal-contaminated soils. In experiments involving canola grown in quartz sand containing 200 mg kg(-1) of Pb, inoculation with the isolated Paenibacillus jamilae HTb8 and Pseudomonas sp. GTa5 was found to significantly increase the above-ground tissues dry weight (ranging from 19% to 36%) and Pb uptake (ranging from 30% to 40%) compared to the uninoculated control. These results show that C. ambrosioides harbor different metal-resistant bacterial communities in their rhizosphere soils and the isolates expressing plant growth promoting traits may be exploited for improving the phytoextraction efficiency of Pb-polluted environment. PMID:22397839

  1. Determining soil enzyme activities for the assessment of fungi and citric acid-assisted phytoextraction under cadmium and lead contamination.

    Science.gov (United States)

    Mao, Liang; Tang, Dong; Feng, Haiwei; Gao, Yang; Zhou, Pei; Xu, Lurong; Wang, Lumei

    2015-12-01

    Microorganism or chelate-assisted phytoextraction is an effective remediation tool for heavy metal polluted soil, but investigations into its impact on soil microbial activity are rarely reported. Consequently, cadmium (Cd)- and lead (Pb)-resistant fungi and citric acid (CA) were introduced to enhance phytoextraction by Solanum nigrum L. under varied Cd and Pb pollution levels in a greenhouse pot experiment. We then determined accumulation of Cd and Pb in S. nigrum and the soil enzyme activities of dehydrogenase, phosphatase, urease, catalase, sucrase, and amylase. Detrended canonical correspondence analysis (DCCA) was applied to assess the interactions between remediation strategies and soil enzyme activities. Results indicated that the addition of fungi, CA, or their combination enhanced the root biomass of S. nigrum, especially at the high-pollution level. The combined treatment of CA and fungi enhanced accumulation of Cd about 22-47 % and of Pb about 13-105 % in S. nigrum compared with the phytoextraction alone. However, S. nigrum was not shown to be a hyperaccumulator for Pb. Most enzyme activities were enhanced after remediation. The DCCA ordination graph showed increasing enzyme activity improvement by remediation in the order of phosphatase, amylase, catalase, dehydrogenase, and urease. Responses of soil enzyme activities were similar for both the addition of fungi and that of CA. In summary, results suggest that fungi and CA-assisted phytoextraction is a promising approach to restoring heavy metal polluted soil. PMID:26286803

  2. Students' Feedback Preferences: How Do Students React to Timely and Automatically Generated Assessment Feedback?

    Science.gov (United States)

    Bayerlein, Leopold

    2014-01-01

    This study assesses whether or not undergraduate and postgraduate accounting students at an Australian university differentiate between timely feedback and extremely timely feedback, and whether or not the replacement of manually written formal assessment feedback with automatically generated feedback influences students' perception of…

  3. Effect of Kiwi Shell and Incubation Time on Mobility of Lead and Cadmium in Contaminated Clay Soil

    OpenAIRE

    Bahareh Lorestani; Chia Arjangi; Hajar Merrikhpour

    2014-01-01

    In this study, the effectiveness of kiwi shell was investigated to reduce the mobility of Lead and Cadmium in clay soil in different intervals. For this purpose a clay soil sample was contaminated with Lead and Cadmium in distinct dishes with 10 and 600 ppm concentrations respectively and mixed with 5% kiwi shell. Samples were placed in incubator, and then sampling of soil in incubator was performed in intervals 3 hours, 1, 3, 7, 14, 21 and 28 days. Heavy metals concentrations were determined...

  4. Beyond mobility assessment: Timed up and go test and its relationship to osteoporosis and fracture risk

    OpenAIRE

    Shereen M. Mousa, MD; Doha Rasheedy, MD; Khalid E. El-Sorady, MSc; Ahmed K. Mortagy, MD

    2016-01-01

    Background: Fracture determinants are falls, bone fragility, imbalance, and decreased lower limb strength. The timed up and go (TUG) test assesses most of the fracture determinants. Aim: To assess the relationship between mobility status using TUG test, bone mineral density (BMD), and different fracture risks predicted by different tools. Methods: A case (TUG time > 20 seconds)–control (TUG ≤ 20 seconds) study comprised 66 patients and 72 controls. Participants were assessed for falls, ...

  5. Reflective (Ac) Counting: Institutional Research, Evaluation, & Assessment in a Time of Cholera

    Science.gov (United States)

    Heinecke, Walter F.

    2011-01-01

    Institutional researchers (IR) and assessment professionals in higher education are living in interesting and challenging times, one might say in times of crisis. As federal and state coffers have shrunk in a time of rising costs of higher education, university budgets are tightening while at the same time calls for accountability are increasing…

  6. Assessment of chronic constipation: colon transit time versus defecography

    Energy Technology Data Exchange (ETDEWEB)

    Prokesch, R.W. E-mail: rupert.prokesch@univie.ac.at; Breitenseher, M.J.; Kettenbach, J.; Herbst, F.; Maier, A.; Lechner, G.; Mahieu, P

    1999-12-01

    Objective: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. Materials and methods: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. Results: Group I, idiopathic constipation (n=11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n=10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n=9), rectal prolapse (n=5) or spastic pelvic floor syndrome (n=4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P<0.05). Conclusion: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG.

  7. Approaches of Seismic Vulnerability Assessments in Near Real Time Systems

    Science.gov (United States)

    Frolova, Nina; Larionov, Valery; Bonnin, Jean; Ugarov, Alexander

    2014-05-01

    Data on seismic vulnerability of existing building stock and other elements at risk are rather important for near real time earthquake loss estimations by global systems. These data together with information on regional peculiarities of seismic intensity attenuation and other factors contribute greatly to the reliability of strong event consequences estimated in emergency mode. There are different approaches for vulnerability functions' development and the empirical one is most often used. It is based on analysis of engineering consequences of past strong events when well documented descriptions of damage to different building types and other elements at risk are available for the earthquake prone area under consideration. In the case such data do not exist the information from macroseismic scales may be used. Any approach of vulnerability functions' development requires the proper classification of buildings and structures under consideration. According to national and international building codes, as well as macroseismic scales different buildings' classifications exist. As a result the global systems, such as Extremum and PAGER, as well as GEM project make use of the non-unified information on building stock distribution worldwide. The paper addresses the issues of buildings' classification and city models in terms of these classifications. Distribution of different buildings types in Extremum and PAGER/GEM systems is analyzed for earthquake prone countries. The comparison of city models revealed significant differences which influence greatly earthquake loss estimations in emergency mode. The paper describes the practice of city models' development which make use of space images and web technology in social networks. It is proposed to use the G8 country (and other) initiatives related to open data and transparency aimed at improving building stock distribution and global population databases.

  8. AN ECOLOGICAL RISK ASSESSMENT OF LEAD SHOT EXPOSURE IN NON-WATERFOWL AVIAN SPECIES: UPLAND GAME BIRDS AND RAPTORS

    Science.gov (United States)

    There is increasing concern that birds in terrestrial ecosystems may be exposed to spent lead shot. Evidence exists that upland birds, particularly mourning doves (Zenaida macroura), ingest spent lead shot and that raptors ingest lead shot by consuming wounded game. Mortality, ne...

  9. Time-lapse synchrotron X-ray diffraction to monitor conservation coatings for heritage lead in atmospheres polluted with oak-emitted volatile organic compounds

    International Nuclear Information System (INIS)

    Highlights: • In situ SR-XRD testing of a natural coating for heritage lead. • An oak environment created within an eCell to study corrosion processes. • Semi-quantification of corrosion layer thickness using time-lapse SR-XRD data. • Identification of VOCs emitted from an oak sample using SPME-GCMS. - Abstract: We discuss the effectiveness of a lead tetradecanoate coating on lead to protect against harmful volatile organic compounds emitted from oak. The oak volatile organic compounds were characterized by GCMS and the major constituent was found to be acetic acid. Under the test conditions, the coating decreases the rate of corrosion by up to 75% compared to bare lead. The thickness of corrosion products on the sample was also calculated thus demonstrating the power of the time-lapse synchrotron radiation X-ray diffraction technique to deliver a quantitative estimate of the effectiveness of the coating

  10. Lead Time Reduction in Budget and Storage Space Restricted Lot Size Reorder Point Inventory Models with Controllable Negative Exponential Backorder Rate

    Directory of Open Access Journals (Sweden)

    A. Gholami-Qadikolaei

    2013-02-01

    Full Text Available This study presents the mixed backorder and lost sales inventory models involving four variables; order quantity, lead time, safety factor (a discrete variable and backorder rate. A controllable negative exponential backorder rate is considered in the proposed model. In the real market, as unsatisfied demands occur, the longer length of lead time is, the smaller proportion of backorder rate would be. Considering this reason, backorder rate is dependent on the length of lead time through the amount of shortages. The negative exponential lead time crashing cost is considered in this study. Today, the cost of land acquisition is high in most of the countries and one of the main concerns of inventory managers is to ensure that the maximum permissible storage space is enough when an order arrives. Hence, a random storage space constraint is considered, since, the inventory level is random when an order arrives. So, in this case, a chance-constrained programming technique is used to make it crisp. Moreover, another significant concern of inventory managers is how to control the maximum investment in the inventory. This study assumes the purchasing cost is paid at the time of order placing. Considering this assumption, a budget constraint is also added to the model in order to managing the maximum inventory investment. The lead time demand, first, follows a normal distribution and then, relaxes the distribution function assumption by only assuming the mean and variance of lead time demand are known and applies the minimax distribution free procedure to solve the problem. Furthermore, a numerical example is also given to illustrate the models and solution procedures.

  11. Response Time as Self-Schema Indicator : Implications for Personality Assessment

    OpenAIRE

    Hedlund, Lars-Erik

    2010-01-01

    The focal objective of this thesis was to examine the potential advantage of introducing the self-schema concept, indexed by response time, into personality assessment. The basic rationale for the use of response time is that a self-schema facilitates response time for self-referent information as it permits people to make assessments easier and automatic. A self-schema is a cognitive structure containing the generic knowledge that people have about themselves, influencing all aspects of the ...

  12. Inequities in the freedom to lead a flourishing and healthy life: time for a progressive social protections framework

    Science.gov (United States)

    Carey, Gemma

    2014-01-01

    Evidence now shows that the key drivers of poor health are social factors, such as education, employment, housing and urban environments. Variations in these social factors—or the conditions in which we live our lives—have lead to a growth in health inequalities within and between countries. One of the key challenges facing those concerned with health equity is how to effect change across the broad policy areas that impact these social PMID:25279385

  13. The value of time from subjective data on life satisfaction and job satisfaction: An empirical assessment

    OpenAIRE

    Isacsson, Gunnar; Karlström, Anders; Swärdh, Jan-Erik

    2008-01-01

    This paper compares estimates of the value of commuting time, working time and household working time from empirical models of subjective assessments of life satisfaction and job satisfaction, respectively, to the corresponding estimates obtained from an empirical search model of the labour market. The results indicate that all three variables produce rather high estimates of the value of commuting time. The results regarding the value of working time differ more between the different outcome...

  14. How does the 6-hour lead time flood forecast issued by the M5 model tree for the Krka River really look like?

    Science.gov (United States)

    Stravs, L.; Brilly, M.

    2009-04-01

    The Krka River is one the main tributaries of the Sava River with a drainage area of approximately 2250 km2. Population areas in the Krka River basin are highly endangered by the possibility of extreme flooding, so knowledge about the river flow's behaviour at the time of extreme events like floods is of the highest importance. By using the M5 machine learning method for generation of regression and model tree models 1-, 2-, 3-, 4-, 5- and 6-hour lead time forecasting models (models which include and forecasting models which don't include up to 6 hours ahead precipitation forecasts) were developed for Podbocje gauging station which is located near the Krka River basin outlet. The data used in the process of model development was hourly flow data for the Podbocje gauging station and hourly rainfall data for two weather stations in the Krka River basin. The data included the period from 1999 to 2004. In the field of hydroinformatics the results of the hydrological modelling with the machine learning methods are usually presented separately (individually) for the models with different forecasting lead times (i.e. separately for 1-hour lead time forecasting model, separately for 3-hour lead time forecasting model, etc.), which is usually pretty inconvenient for the end users of the flood forecasting models. So the aim of our research was to evaluate flood forecasts in the form of 6-hour ahead flood forecast curves produced by the combined application of the 6 model tree models with 1-, 2-, 3-, 4-, 5- and 6-hour lead times at the same time. Analysis included both visual and numerical evaluation of the results obtained by the application of the forecasting models with and without the inclusion of the precipitation forecasts in the models' structure.

  15. Ignoring Individual Differences in Times of Assessment in Growth Curve Modeling

    Science.gov (United States)

    Coulombe, Patrick; Selig, James P.; Delaney, Harold D.

    2016-01-01

    Researchers often collect longitudinal data to model change over time in a phenomenon of interest. Inevitably, there will be some variation across individuals in specific time intervals between assessments. In this simulation study of growth curve modeling, we investigate how ignoring individual differences in time points when modeling change over…

  16. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites

  17. LEADING WITH LEADING INDICATORS

    Energy Technology Data Exchange (ETDEWEB)

    PREVETTE, S.S.

    2005-01-27

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites.

  18. Atmospheric deposition of trace elements around point sources and human health risk assessment. I: Impact zones around a lead source

    DEFF Research Database (Denmark)

    Moseholm, L.; Larsen, Erik Huusfeldt; Andersen, B.;

    1992-01-01

    The deposition of lead was monitored over 8 years in the area around a car battery factory north of Copenhagen, Denmark. The area also has heavy traffic. Deposition was measured by in-situ grown vegetables, transplant grass culture biomonitors, bulk deposition and soil samples. Three impact zones...... were identified by a multivariate statistical analysis. Within each zone, the total dietary intake of lead was estimated for adults and children as a percentage of the provisional tolerably weekly intake (PTWI), and as a result recommendation on restrictions in use of locally grown fruit and vegetables...... were given to the public. The pattern of lead deposition in the area during the period 1981-1988 was monitored and the amount of lead ingested via vegetables was toxically evaluated. Lead emission reduction measures introduced in the factory and in the traffic during the period produced significant...

  19. Enhanced time response of 1-in. LaBr3(Ce) crystals by leading edge and constant fraction techniques

    International Nuclear Information System (INIS)

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr3(Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at 60Co and 22Na γ-ray energies against a fast BaF2 reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr3(Ce) time resolution from the best literature value at 60Co photon energies to below 100 ps

  20. Enhanced time response of 1-in. LaBr3(Ce) crystals by leading edge and constant fraction techniques

    Science.gov (United States)

    Vedia, V.; Mach, H.; Fraile, L. M.; Udías, J. M.; Lalkovski, S.

    2015-09-01

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr3(Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at 60Co and 22Na γ-ray energies against a fast BaF2 reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr3(Ce) time resolution from the best literature value at 60Co photon energies to below 100 ps.

  1. Enhanced time response of 1-in. LaBr3(Ce) crystals by leading edge and constant fraction techniques

    CERN Document Server

    Vedia, V; Fraile, L M; Udias, J M; Lalkovski, S

    2015-01-01

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr$_{3}$ (Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at $^{60}$Co and $^{22}$Na {\\gamma}-ray energies against a fast BaF$_{2}$ reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr$_{3}$(Ce) time resolution from the best literature value at 60Co photon energies to below 100 ps.

  2. Enhanced time response of 1-in. LaBr{sub 3}(Ce) crystals by leading edge and constant fraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Vedia, V., E-mail: mv.vedia@ucm.es [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); Mach, H. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); National Centre for Nuclear Research, Division for Nuclear Physics, BP1, PL-00-681 Warsaw (Poland); Fraile, L.M.; Udías, J.M. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); Lalkovski, S. [Faculty of Physics, University of Sofia, St. Kliment Ohridski, BG-1164 Sofia (Bulgaria)

    2015-09-21

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr{sub 3}(Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at {sup 60}Co and {sup 22}Na γ-ray energies against a fast BaF{sub 2} reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr{sub 3}(Ce) time resolution from the best literature value at {sup 60}Co photon energies to below 100 ps.

  3. Model-Based Real Time Assessment of Capability Left for Spacecraft Under Failure Mode Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is aimed at developing a model based diagnostics system for spacecraft that will allow real time assessment of its state, while it is impacted...

  4. Assessment of Clogging Dynamics in Permeable Pavement Systems with Time Domain Reflectometers

    Science.gov (United States)

    Infiltration is a primary functional mechanism in green infrastructure stormwater controls. This study used time domain reflectometers (TDRs) to measure spatial infiltration and assess clogging dynamics of permeable pavement systems in Edison, NJ, and Louisville, KY. In 2009, t...

  5. The Role of Timing in Assessing Oral Reading Fluency and Comprehension in Kenya

    Science.gov (United States)

    Piper, Benjamin; Zuilkowski, Stephanie Simmons

    2016-01-01

    Despite rapid growth in literacy-related programmes and evaluation in sub-Saharan Africa, little critical attention has been paid to the relevance of assumptions that underlie existing assessment methods. This study focuses on the issue of timing in the assessment of oral reading fluency, a critical component of successful reading (Chard, Vaughn,…

  6. Pain assessment in time to get pain treatment on time – patients’ perspective of time during pain assessment after spine surgery

    DEFF Research Database (Denmark)

    Kaptain, Kirsten; Bregnballe, Vibeke; Dreyer, Pia

    Background: Despite advances in medicine, pharmaceutical and technical knowledge, patients still have postop-erative pain after spine surgery. Studies show that patient participation has positive effect on treatment outcomes and patients require quick individual and efficient pain treatment....... Objective: This study explored how spine surgery patients experienced participation in assessment of their postoperative pain. Design: This study had a qualitative approach with a phenomenological-hermeneutic perspective. Data was collected via semi-structured interviews of 15 patients and was analysed via...

  7. Functional assessment in older adults: should we use timed up and go or gait speed test?

    Science.gov (United States)

    Kubicki, Alexandre

    2014-08-01

    In order to assess functional skills of older adults, both timed up and go (TUG) test and gait speed (GS) test are well validated concerning their predictive capacities. However, the question remains unclear which one of these tests represents better the whole physical performance of older adults. The aim of this study is to determine the more representative test, between TUG and GS, of the whole motor control quality. To study links between locomotion capacities and arm function, we measured, in a population of frail aged patients, the locomotion tests and the mean arm maximal velocity developed during a speed-accuracy trade-off. This arm movement consisted in reaching the hand toward a target in a virtual game scene. We plotted the different couples of variables obtained on graphs, and calculate Pearson correlation coefficients between each couple. The Pearson correlation between GS and hand maximal velocity was significant (r=0.495; p=0.046). Interestingly, we found a non significant Pearson correlation between timed up and go score (TUG) and hand maximal velocity (r=-0.139; p=0.243). Our results suggest that GS score is more representative of the whole motor ability of frail patients than the TUG. We propose that the relative complexity of the TUG motor sequence could be involved in this difference. For a few patients with motor automatisms deficiencies, this motor sequence complexity could leads to a dual task perturbation. In this way, we conclude that GS should be preferred over the TUG with older adults. PMID:24933540

  8. Heat wave over India during summer 2015: an assessment of real time extended range forecast

    Science.gov (United States)

    Pattanaik, D. R.; Mohapatra, M.; Srivastava, A. K.; Kumar, Arun

    2016-06-01

    Hot winds are the marked feature of summer season in India during late spring preceding the climatological onset of the monsoon season in June. Some years the conditions becomes very vulnerable with the maximum temperature (T max) exceeding 45 °C for many days over parts of north-western, eastern coastal states of India and Indo-Gangetic plain. During summer of 2015 (late May to early June) eastern coastal states, central and northwestern parts of India experienced severe heat wave conditions leading to loss of thousands of human life in extreme high temperature conditions. It is not only the loss of human life but also the animals and birds were very vulnerable to this extreme heat wave conditions. In this study, an attempt is made to assess the performance of real time extended range forecast (forecast up to 3 weeks) of this scorching T max based on the NCEP's Climate Forecast System (CFS) latest version coupled model (CFSv2). The heat wave condition was very severe during the week from 22 to 28 May with subsequent week from 29 May to 4 June also witnessed high T max over many parts of central India including eastern coastal states of India. The 8 ensemble members of operational CFSv2 model are used once in a week to prepare the weekly bias corrected deterministic (ensemble mean) T max forecast for 3 weeks valid from Friday to Thursday coinciding with the heat wave periods of 2015. Using the 8 ensemble members separately and the CFSv2 corresponding hindcast climatology the probability of above and below normal T max is also prepared for the same 3 weeks. The real time deterministic and probabilistic forecasts did indicate impending heat wave over many parts of India during late May and early June of 2015 associated with strong northwesterly wind over main land mass of India, delaying the sea breeze, leading to heat waves over eastern coastal regions of India. Thus, the capability of coupled model in providing early warning of such killer heat wave can be very

  9. Assessment of in situ immobilization of Lead (Pb) and Arsenic (As) in contaminated soils with phosphate and iron: solubility and bioaccessibility

    NARCIS (Netherlands)

    Cui, Y.S.; Du, X.; Weng, L.P.; Riemsdijk, van W.H.

    2010-01-01

    The effect of in situ immobilization of lead (Pb) and arsenic (As) in soil with respectively phosphate and iron is well recognized. However, studies on combined Pb and As-contaminated soil are fewer, and assessment of the effectiveness of the immobilization on mobility and bioaccessibility is also n

  10. A divergent synthetic approach to diverse molecular scaffolds: assessment of lead-likeness using LLAMA, an open-access computational tool.

    Science.gov (United States)

    Colomer, Ignacio; Empson, Christopher J; Craven, Philip; Owen, Zachary; Doveston, Richard G; Churcher, Ian; Marsden, Stephen P; Nelson, Adam

    2016-06-01

    Complementary cyclisation reactions of hex-2-ene-1,6-diamine derivatives were exploited in the synthesis of alternative molecular scaffolds. The value of the synthetic approach was analysed using LLAMA, an open-access computational tool for assessing the lead-likeness and novelty of molecular scaffolds. PMID:27145833

  11. Real-time safety risk assessment based on a real-time location system for hydropower construction sites.

    Science.gov (United States)

    Jiang, Hanchen; Lin, Peng; Fan, Qixiang; Qiang, Maoshan

    2014-01-01

    The concern for workers' safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA) to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge of safety with more abundant information to reduce the uncertainty of the site. A quantitative calculation formula, integrating the influence of static and dynamic hazards and that of safety supervisors, is established to link the safety risk of workers with the locations of on-site assets. By employing the hidden Markov model (HMM), the RTSRA provides a mechanism for processing location data provided by the real-time location system (RTLS) and analyzing the probability distributions of different states in terms of false positives and negatives. Simulation analysis demonstrated the logic of the proposed method and how it works. Application case shows that the proposed RTSRA is both feasible and effective in managing construction project safety concerns. PMID:25114958

  12. Real-Time Safety Risk Assessment Based on a Real-Time Location System for Hydropower Construction Sites

    Directory of Open Access Journals (Sweden)

    Hanchen Jiang

    2014-01-01

    Full Text Available The concern for workers’ safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge of safety with more abundant information to reduce the uncertainty of the site. A quantitative calculation formula, integrating the influence of static and dynamic hazards and that of safety supervisors, is established to link the safety risk of workers with the locations of on-site assets. By employing the hidden Markov model (HMM, the RTSRA provides a mechanism for processing location data provided by the real-time location system (RTLS and analyzing the probability distributions of different states in terms of false positives and negatives. Simulation analysis demonstrated the logic of the proposed method and how it works. Application case shows that the proposed RTSRA is both feasible and effective in managing construction project safety concerns.

  13. The welfare of farmed mink should be easy to assess in a correct way and lead to animal welfare improvements

    DEFF Research Database (Denmark)

    Henriksen, Britt

    reduce the number of measurements needed in the welfare assessment system WelFur-Mink in the different production periods without compromising the validity of the assessment. There seems to be an effect of date of the assessment in the nursing period, which can be handled elegantly if the other two...... periods have the same effect of date of assessment. The study also found that mink farmers are generally positive towards the structural way of working in stable schools and that including a discussion of the WelFur results related to the different farms in a stable school will make the feedback...

  14. Frugal innovations for the 'unserved' customer: An assessment of India's attractiveness as a lead Market for cost-effective products

    OpenAIRE

    Tiwari, Rajnish; Herstatt, Cornelius

    2012-01-01

    This study builds on our previous work, which had questioned the validity of certain assumptions of the lead market theory in the face of changing ground realities in a globalized world. Sustained economic growth and proven technological capabilities in some "emerging economies" like China and India call for a reassessment of the appropriateness of the "conventional wisdom" that had held true until recently. While our previous study had "re-built" a theoretical background of the lead market m...

  15. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Lee, Byeong Cheol [Seoul Nationl Univ., Seoul (Korea, Republic of)] (and others)

    1996-07-15

    The objectives of this study is the development of methodology by which assessing the optimizes Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korea nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches is performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method.

  16. Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Corey C. (University of New Mexico, Albuquerque, NM); Taylor, Paul Allen

    2008-02-01

    The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

  17. Real time control of fully non-inductive operation in Tore Supra leading to 6 min, 1 GJ plasma discharges

    International Nuclear Information System (INIS)

    The experimental programme of Tore Supra (a = 0.72 m, R = 2.4 m, I p T < 4.5 T) has been devoted in 2003 to study simultaneously heat removal capability and particle exhaust in steady-state fully non-inductive current drive discharges. This required both advanced technology integration and steady-state real time plasma control. In particular, an improvement of the plasma position within a few millimetres range, and new real time cross controls between radio frequency (RF) power and various actuators built around a shared memory network, have allowed Tore Supra to access a powerful steady-state regime with an improved safety level for the actively cooled plasma facing components. Feedback controlled fully non-inductive plasma discharges have been sustained in a steady-state regime up to 6 min with a new world record of injected-extracted energy exceeding 1 GJ. Advanced tools, experimental results and brief physics analysis of these discharges are presented and discussed

  18. Assessment of reverberation time by two measurement systems for room electromagnetics analysis

    DEFF Research Database (Denmark)

    Bamba, Aliou; Joseph, Wout; Plets, David; Tanghe, Emmeric; Vermeeren, Günter; Martens, Luc; Andersen, Jørgen Bach; Nielsen, Jesper Ødum

    measurement systems and antennas characteristics are discussed. The goal of this paper is the assessment of the reverberation time in an environment with different measurement systems. From the reverberation time one can derive the absorption area and hence the absorption cross section for humans in realistic...

  19. Prime-Time Television: Assessing Violence during the Most Popular Viewing Hours.

    Science.gov (United States)

    Smith, Stacy L.; Nathanson, Amy I.; Wilson, Barbara J.

    2002-01-01

    Assesses the prevalence and context of violence in prime-time television programming using a random, representative sample. Shows that, regardless of the time of day, viewers are likely to encounter violence in roughly 2 out of 3 programs. Identifies specific channel types and genres that feature potentially harmful depictions of violence during…

  20. Reduction of referral to assessment time for an older adults community mental health team

    OpenAIRE

    Sin Fai Lam, Chun Chiang

    2016-01-01

    Anecdotal evidence suggested that waiting times within the older adults community mental health team (OA CMHT) had been increasing over time. An assessment and evaluation was indicated to ensure best quality care was provided for patients. A comparison was made between waiting times in January to December 2011 compared with August 2013 to July 2014. In 2011 the mean number of days until initial assessment from the point of referral was 12 days for routine cases, and 3.6 days for urgent cases....

  1. External costs of atmospheric lead emissions from a waste-to-energy plant: a follow-up assessment of indirect neurotoxic impacts via topsoil ingestion

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Møller, Flemming; Thomsen, Marianne

    2013-01-01

    The link between anthropogenic emissions and the monetary value of their impacts, so-called external cost, can be determined via the impact pathway approach. This method is used in the present study to calculate the indirect costs, via topsoil ingestion, of lead emitted into atmosphere from a waste...... magnitude as direct costs previously investigated, both in the case of actual emission rates and in the case of future emission scenarios for lead. Among the various modelling parameters, the choices of time horizon and of social discount rate have the most influential effect: discounting of future impacts...... respectively. The use of such lead-specific models allows for a detailed quantification of the lead impact pathway. External costs are calculated by linking lead exposure to neurotoxic impacts in children and to the consequent reduced lifetime earnings. Results indicate that indirect costs are of the same...

  2. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  3. Assessment of concentration of lead, cadmium, chromium and selenium in blood serum of cancer and diabetic patients of Pakistan

    International Nuclear Information System (INIS)

    Heavy metals have specific role in the progression of diseases. The aim of this study was to investigate the level of toxic elements, i.e. lead, cadmium, chromium and selenium in blood serum of type 1 diabetes mellitus and cancer patients. Samples were collected from Institute of Nuclear Medicine and Oncology, Lahore (INMOL) Hospital and Jinnah Hospital, Lahore. They were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). Concentrations of toxic metals, i.e. lead, cadmium and chromium have been found relatively high in both cancer and diabetic patients where as concentration of selenium was relatively lower than the normal subjects. (author)

  4. Assessment of cadmium, copper and lead in marine species of the atlantic and pacific oceans of Guatemala by voltametry techniques

    International Nuclear Information System (INIS)

    In this thesis results of measurements of cooper, lead, and cadmium were made using voltametry. Three points in the pacific ocean and one in the atlantic were selected to obtain samples of fish and shrimp as species that are contaminated with toxic metals. The samples were treated by physical and chemical methods to turn soluble the metals and the chemical determination could be done using voltametry or differential polarography of pulse. The results shown that copper, lead and cadmium are present in the samples in traces level. The precision of measurements was verified measuring certified by the National Institute of Standard and Technology NIST of the Commerce Departmento of the United States

  5. Assessment of Long Term Impacts of Cadmium and Lead Load to Agricultural Soils in the Upper Elbe and Oder River Basins

    OpenAIRE

    Prieler, S.; Anderberg, S.

    1996-01-01

    This report investigates effects of long term load of two heavy metals, cadmium and lead to agricultural soils for a project area in Central Europe. The time frame for the historic analysis is 1955 to 1994. The major source of lead is atmospheric deposition. In the case of cadmium, besides atmospheric deposition, agricultural activities, such as P-fertilizer and manuring, are additional sources of heavy metal input to agricultural soils. Extremely high depositions that were measured in a "hot...

  6. Probabilistic assessment of fuel channel bearing travel and end of bearing time

    International Nuclear Information System (INIS)

    Operators in Ontario have been assessing fuel channel elongation in nuclear generating units to ensure fuel channels remain on bearing at least until the next inspection in accordance with CSA N285.4. These assessments have so far been performed deterministically and, among other conservative assumptions, use the worst stack-up of tolerances for all relevant fuel channel components to calculate the end-of-bearing (EOB) times. Since the probability of having the worst stack-up of tolerances occurring is extremely small, a deterministic assessment provides a very conservative representation of the unit condition. The probabilistic assessment presented in this paper provides a more realistic representation of elongation and channel end-of-bearing times. For a given reactor, the probabilistic assessment used Monte Carlo techniques to generate values for fuel channel component dimensions, current fuel channel elongations, future elongations and elongation measurement errors from specified distributions. The simulated values are then used to obtain a distribution of EOB times at each lattice position in the reactor. The expected number of fuel channels reaching EOB in a given operating interval can then be compared to pre-established acceptance criteria to determine if the operating interval is acceptable. The methodology is illustrated with an example reactor. The results from 100,000 simulations at each lattice position show that the EOB times calculated in the deterministic assessment corresponded to a very low percentile of the EOB times calculated in the probabilistic assessment. This indicated that the deterministic assessment was very conservative. For the example reactor, no elongation maintenance would be necessary for approximately one year (8,000 effective full power hours) after the latest outage. (author)

  7. Atmospheric deposition of trace elements around point sources and human health risk assessment. I: Impact zones around a lead source

    DEFF Research Database (Denmark)

    Moseholm, L.; Larsen, Erik Huusfeldt; Andersen, B.; Nielsen, M. M.

    1992-01-01

    were identified by a multivariate statistical analysis. Within each zone, the total dietary intake of lead was estimated for adults and children as a percentage of the provisional tolerably weekly intake (PTWI), and as a result recommendation on restrictions in use of locally grown fruit and vegetables...

  8. Combination of Didactic Lectures and Review Sessions in Endocrinology Leads to Improvement in Student Performance as Measured by Assessments

    Science.gov (United States)

    Qureshi, Ayisha; Cozine, Cassy; Rizvi, Farwa

    2013-01-01

    There can be no single best way of learning, and each teaching mode has its own merits and demerits. Didactic lectures in and of themselves are insufficient, whereas a problem-based tutorial alone can be as ineffective. This study was conducted to determine if a problem-based review after didactic lectures would lead to better student performance.…

  9. Assessing error sources for Landsat time series analysis for tropical test sites in Viet Nam and Ethiopia

    Science.gov (United States)

    Schultz, Michael; Verbesselt, Jan; Herold, Martin; Avitabile, Valerio

    2013-10-01

    Researchers who use remotely sensed data can spend half of their total effort analysing prior data. If this data preprocessing does not match the application, this time spent on data analysis can increase considerably and can lead to inaccuracies. Despite the existence of a number of methods for pre-processing Landsat time series, each method has shortcomings, particularly for mapping forest changes under varying illumination, data availability and atmospheric conditions. Based on the requirements of mapping forest changes as defined by the United Nations (UN) Reducing Emissions from Forest Degradation and Deforestation (REDD) program, the accurate reporting of the spatio-temporal properties of these changes is necessary. We compared the impact of three fundamentally different radiometric preprocessing techniques Moderate Resolution Atmospheric TRANsmission (MODTRAN), Second Simulation of a Satellite Signal in the Solar Spectrum (6S) and simple Dark Object Subtraction (DOS) on mapping forest changes using Landsat time series data. A modification of Breaks For Additive Season and Trend (BFAST) monitor was used to jointly map the spatial and temporal agreement of forest changes at test sites in Ethiopia and Viet Nam. The suitability of the pre-processing methods for the occurring forest change drivers was assessed using recently captured Ground Truth and high resolution data (1000 points). A method for creating robust generic forest maps used for the sampling design is presented. An assessment of error sources has been performed identifying haze as a major source for time series analysis commission error.

  10. Inventory Modelling for a Manufacturer of Sweets: An Evaluation of an Adjusted Compund Renewal Approach for B-Items With A Relative Short Production Lead Time

    OpenAIRE

    Heuts, R.M.J.; Luijten, M.L.J.

    1999-01-01

    In this paper we are especially interested how to optimize the production/inventory control for a manufacturer of sweets, under the following circumstances: short production lead times in combination with an intermittent demand pattern for the so-called B-taste items. As for A-taste items a compound renewal approach appeared appropriate to control inventory/production, we formulated and tested an adjusted compound renewal approach for B-taste items, because a certain condition was not satisfi...

  11. A near real-time procedure for flood hazard mapping and risk assessment in Europe

    OpenAIRE

    DOTTORI FRANCESCO; Kalas, Milan; Salamon, Peter; BIANCHI ALESSANDRA; THIELEN DEL POZO Jutta; Feyen, Luc

    2014-01-01

    The availability of a real-time operational system for mapping flood hazard and assessing potential consequences might be extremely useful to help emergency response and management and to mitigate the impact of large flood events. This work describes the development of an experimental procedure for rapid flood risk assessment within the European Flood Awareness System (EFAS), which since 2012 provides operational flood predictions for the major European rivers as part of the Copernicus Emerge...

  12. Continuous Arousal Self-assessments Validation Using Real-time Physiological Responses

    OpenAIRE

    Li, Ting; Baveye, Yoann; Chamaret, Christel; Dellandréa, Emmanuel; Chen, Liming

    2015-01-01

    On one hand, the fact that Galvanic Skin Response (GSR) is highly correlated with the user affective arousal provides the possibility to apply GSR in emotion detection. On the other hand, temporal correlation of real-time GSR and self-assessment of arousal has not been well studied. This paper confronts two modalities representing the induced emotion when watching 30 movies extracted from the LIRIS-ACCEDE database. While continuous arousal annotations have been self-assessed by 5 participants...

  13. Approaches to assessment in time-limited Mentalization-Based Therapy for Children (MBT-C)

    OpenAIRE

    Muller, Nicole; Midgley, Nick

    2015-01-01

    In this article we describe our clinical approach to assessment, formulation and the identification of a therapeutic focus in the context of time-limited Mentalization-Based Treatment for Children (MBT-C) aged between 6 and 12. Rather than seeing the capacity to mentalize as a global construct, we set out an approach to assessing the developmental ‘building blocks’ of the capacity to mentalize the self and others, including the capacity for attention regulation, emotion regulation, and explic...

  14. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    International Nuclear Information System (INIS)

    Highlights: • Trace element concentrations and lead isotopic ratios were measured in sediment. • Increased element fluxes driven by increased erosion rates linked to land use changes. • Lead isotopic ratios suggest the two sites received lead input from different sources. - Abstract: Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite

  15. Long Lead-Time Forecasting of Snowpack and Precipitation in the Upper Snake River Basin using Pacific Oceanic-Atmospheric Variability

    Science.gov (United States)

    Anderson, S.; Tootle, G.; Parkinson, S.; Holbrook, P.; Blestrud, D.

    2012-12-01

    Water managers and planners in the western United States are challenged with managing resources for various uses, including hydropower. Hydropower is especially important throughout the Upper Snake River Basin, where a series of hydropower projects provide a low cost renewable energy source to the region. These hydropower projects include several dams that are managed by Idaho Power Company (IPC). Planners and managers rely heavily on forecasts of snowpack and precipitation to plan for hydropower availability and the need for other generation sources. There is a pressing need for improved snowpack and precipitation forecast models in the Upper Snake River Basin. This research investigates the ability of Pacific oceanic-atmospheric data and climatic variables to provide skillful long lead-time (three to nine months) forecasts of snowpack and precipitation, and examines the benefits of segregating the warm and cold phases of the Pacific Decadal Oscillation (PDO) to reduce the temperature variability within the target dataset. Singular value decomposition (SVD) was used to identify regions of Pacific Ocean sea surface temperatures (SST) and 500mbar geopotential heights (Z500) for various lead times (three, six, and nine months) that were teleconnected with snowpack and precipitation stations in Upper Snake River Basin headwaters. The identified Pacific Ocean SST and Z500 regions were used to create indices that became predictors in a non-parametric forecasting model. The majority of forecasts resulted in positive statistical skill, which indicated an improvement of the forecast over the climatology forecast (no-skill forecast). The results from the forecasts models indicated that derived indices from the SVD analysis resulted in improved forecast skill when compared to forecasts using established climate indices. Segregation of the cold phase PDO years resulted in the identification of different regions in the Pacific Ocean and vastly improved skill for the nine month

  16. Suitability of voltage stability study methods for real-time assessment

    DEFF Research Database (Denmark)

    Perez, Angel; Jóhannsson, Hjörtur; Vancraeyveld, Pieter;

    2013-01-01

    This paper analyzes the suitability of existing methods for long-term voltage stability assessment for real-time operation. An overview of the relevant methods is followed with a comparison that takes into account the accuracy, computational efficiency and characteristics when used for security...... assessment. The results enable an evaluation of the run time of each method with respect to the number of inputs. Furthermore, the results assist in identifying which of the methods is most suitable for realtime operation in future power system with production based on fluctuating energy sources....

  17. Proposta para a gestão de estoques de novos produtos: solução do modelo (Q,r para a distribuição uniforme da demanda e do lead-time de suprimento A proposal for new product inventory management: solution of the (Q,r inventory model for uniform distribution of demand and and lead-time

    Directory of Open Access Journals (Sweden)

    Peter Wanke

    2005-04-01

    Full Text Available As premissas comumente consideradas nos modelos de estoques - aderência da demanda no lead-time de suprimento à Distribuição Normal, média e desvio-padrão conhecidos e lead-time de suprimento discreto - são freqüentemente irrealistas e podem implicar substanciais distorções na gestão dos estoques de novos produtos, sobretudo nos custos totais e nos indicadores de nível de serviço. Considerando que as empresas simultaneamente estocam os novos produtos e aprendem ao longo do tempo sobre as características da distribuição da demanda no lead-time de suprimento, é desenvolvida nesse artigo a solução do modelo (Q,r - tamanho de lote e ponto de pedido - para o caso da demanda e do lead-time de suprimento com Distribuição Uniforme. Por ser definida por meio de dois parâmetros mais intuitivos que a média e o desvio-padrão - máximo e mínimo - e representar situações em que qualquer resultado tem igual probabilidade de ocorrência, a premissa da Distribuição Uniforme pode constituir uma primeira abordagem prática para a gestão de estoques de novos produtos.The premises commonly adopted in inventory management models - adherence of lead-time demand to Normal Distribution, known average and standard deviations, and discrete lead time - are often unrealistic and can lead to considerable distortions in new product inventories, particularly insofar as total costs and service level indicators are concerned. Considering that companies stock new products while simultaneously learning about the characteristics of lead-time demand distribution, this paper proposes the solution to the (Q,r - order quantity and reorder point - inventory model for uniform demand and lead-time. The premise of Uniform Distribution is defined by two parameters that are more intuitive than mean and standard deviation - maximum and minimum - and it can also be applied when a result shows the same probability of occurring. Therefore, its adoption may be the

  18. Archives of Atmospheric Lead Pollution

    Science.gov (United States)

    Weiss, Dominik; Shotyk, William; Kempf, Oliver

    Environmental archives such as peat bogs, sediments, corals, trees, polar ice, plant material from herbarium collections, and human tissue material have greatly helped to assess both ancient and recent atmospheric lead deposition and its sources on a regional and global scale. In Europe detectable atmospheric lead pollution began as early as 6000years ago due to enhanced soil dust and agricultural activities, as studies of peat bogs reveal. Increased lead emissions during ancient Greek and Roman times have been recorded and identified in many long-term archives such as lake sediments in Sweden, ice cores in Greenland, and peat bogs in Spain, Switzerland, the United Kingdom, and the Netherlands. For the period since the Industrial Revolution, other archives such as corals, trees, and herbarium collections provide similar chronologies of atmospheric lead pollution, with periods of enhanced lead deposition occurring at the turn of the century and since 1950. The main sources have been industry, including coal burning, ferrous and nonferrous smelting, and open waste incineration until c.1950 and leaded gasoline use since 1950. The greatest lead emissions to the atmosphere all over Europe occurred between 1950 and 1980 due to traffic exhaust. A marked drop in atmospheric lead fluxes found in most archives since the 1980s has been attributed to the phasing out of leaded gasoline. The isotope ratios of lead in the various archives show qualitatively similar temporal changes, for example, the immediate response to the introduction and phasing out of leaded gasoline. Isotope studies largely confirm source assessments based on lead emission inventories and allow the contributions of various anthropogenic sources to be calculated.

  19. Reduction of referral to assessment time for an older adults community mental health team.

    Science.gov (United States)

    Sin Fai Lam, Chun Chiang

    2016-01-01

    Anecdotal evidence suggested that waiting times within the older adults community mental health team (OA CMHT) had been increasing over time. An assessment and evaluation was indicated to ensure best quality care was provided for patients. A comparison was made between waiting times in January to December 2011 compared with August 2013 to July 2014. In 2011 the mean number of days until initial assessment from the point of referral was 12 days for routine cases, and 3.6 days for urgent cases. The re-audit showed the number of days increased to 15.89 days for routine cases, and 9.81 days for urgent cases. Contributory factors were reviewed, and it was felt that to address this problem, a duty worker role was necessary. The role of the duty worker was divided into triaging and allocating work. The triaging process was to ensure all urgent cases were highlighted early and acted upon. The duty worker's role was also to gather sufficient information from the referrer, to reduce the risks of inadequate knowledge delaying assessment. In addition, the allocating process required the duty worker to designate a clinician in charge of the case upon receipt of referral. This ensured that clinicians were able to offer the earliest possible appointment slot for the initial assessment, and thus reduce waiting times. Following implementation, findings from September 2014 to February 2015 showed an improvement in average waiting times, as well as an improvement in the percentage of assessments reviewed within previously set standards. For routine reviews, the mean time until assessment was 10.68 days. For urgent reviews, the mean time until initial assessment was 6.8 days. However, it was noted that majority of urgent reviews were still not being reviewed in time. The outcomes of this study demonstrated an improvement of both waiting times, and percentage of patients being seen within set standards following a single intervention. In the current climate of cost efficiency savings

  20. Incorporation of lithium lead eutectic as a working fluid in RELAP5 and preliminary safety assessment of LLCS

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, A.K., E-mail: trivedi@iitk.ac.in [Nuclear Engineering and Technology Programme, Indian Institute of Technology, Kanpur 208016 (India); Sandeep, K.T. [Institute for Plasma Research, Gandhinagar 382428 (India); Allison, C. [Innovative Systems Software, Idaho Falls, ID 83406 (United States); Khanna, A., E-mail: akhanna@iitk.ac.in [Nuclear Engineering and Technology Programme, Indian Institute of Technology, Kanpur 208016 (India); Chaudhari, V.; Kumar, E.R. [Institute for Plasma Research, Gandhinagar 382428 (India); Munshi, P. [Nuclear Engineering and Technology Programme, Indian Institute of Technology, Kanpur 208016 (India)

    2014-12-15

    Highlights: • The current work involves thermal hydraulic calculation of Lithium Lead Cooling System (LLCS) for the Indian test blanket module (TBM) for testing in ITER. • It uses the RELAP portion of RELAP/SCDAPSIM/MOD4.0. • RELAP steady state results closely match with the operating conditions of LLCS. • Results from transient calculations show that a maximum temperature of 875 K is attained 300 s after the loss of LLE flow. - Abstract: The current work involves thermal hydraulic calculation of Lithium Lead Cooling System (LLCS) for the Indian test blanket module (TBM) for testing in International Thermonuclear Experimental reactor (ITER). It uses the RELAP portion of RELAP/SCDAPSIM/MOD4.0. Lithium-lead eutectic (LLE) has been used as multiplier, breeder and coolant in TBM. Thermodynamic and transport properties of the LLE have been incorporated into the code. The main focus of this study is to check the heat transfer capability of LLE as coolant for TBM system for steady state and the considered anticipated operational occurrences (AOO's), namely, loss of heat source, loss of primary flow and loss of secondary flow. The six heat transfer correlation (reported for liquid metals in the literature) has been tested for steady state analysis of LLCS loop and results are roughly same for all of them. A good agreement has been observed between the operating conditions of LLCS with those of RELAP5 calculations. Results from transient calculations show that a maximum temperature of 875 K is attained during a 300 s loss of primary flow (LLE)

  1. Does climate policy lead to relocation with adverse effects for GHG emissions or not? A first assessment of the spillovers of climate policy for energy intensive industry

    International Nuclear Information System (INIS)

    Energy-intensive industries play a special role in climate policy. World-wide, industry is responsible for about 50% of greenhouse gas emissions. The emission intensity makes these industries an important target for climate policy. At the same time these industries are particularly vulnerable if climate policy would lead to higher energy costs, and if they would be unable to offset these increased costs. The side effects of climate policy on GHG emissions in foreign countries are typically referred to as 'spillovers'. Negative spillovers reduce the effectiveness of a climate policy, while positive spillovers increase its effectiveness. This paper provides a review of the literature on the spillover effects of climate policy for carbon intensive industries. Reviews of past trends in production location of energy-intensive industries show an increased share of non-Annex 1 countries. However, this trend is primarily driven by demand growth, and there is no empirical evidence for a role of environmental policy in these development patterns. In contrast, climate models do show a strong carbon leakage of emissions from these industries. Even though that climate policy may have a more profound impact than previous environmental policies, the results of the modelling are ambiguous. The energy and carbon intensity of energy-intensive industries is rapidly declining in most developing countries, and reducing the 'gap' between industrialized and developing countries. Still, considerable potential for emission reduction exists, both in developing and industrialized countries. Technology development is likely to deliver further reductions in energy use and CO2 emissions. Despite the potential for positive spillovers in the energy-intensive industries, none of the models used in the analysis of spillovers of climate policies has an endogenous representation of technological change for the energy-intensive industries. This underlines the need for a better understanding of

  2. Assessing the Mobility of Lead, Copper and Cadmium in a Calcareous Soil of Port-au-Prince, Haiti

    OpenAIRE

    Urbain Fifi; Thierry Winiarski; Evens Emmanuel

    2013-01-01

    The presence of heavy metals in the environment constitutes a potential source of both soil and groundwater pollution. This study has focused on the reactivity of lead (Pb), copper (Cu) and Cadmium (Cd) during their transfer in a calcareous soil of Port-au-Prince (Haiti). Kinetic, monometal and competitive batch tests were carried out at pH 6.0. Two simplified models including pseudo-first-order and pseudo-second-order were used to fit the experimental data from kinetics adsorption batch test...

  3. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  4. Investigation of the Adaptability of Transient Stability Assessment Methods to Real-Time Operation

    OpenAIRE

    Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Sommer, Stefan; Østergaard, Jacob

    2012-01-01

    In this paper, an investigation of the adaptability of available transient stability assessment methods to real-time operation and their real-time performance is carried out. Two approaches based on Lyapunov’s method and the equal area criterion are analyzed. The results allow to determine the runtime of each method with respect to the number of inputs. Furthermore, it allows to identify, which method is preferable in case of changes in the power system such as the integration of distributed ...

  5. Structural Nested Mean Models for Assessing Time-Varying Effect Moderation

    OpenAIRE

    Almirall, Daniel; Ten Have, Thomas; Murphy, Susan A.

    2009-01-01

    This article considers the problem of assessing causal effect moderation in longitudinal settings in which treatment (or exposure) is time-varying and so are the covariates said to moderate its effect. Intermediate Causal Effects that describe time-varying causal effects of treatment conditional on past covariate history are introduced and considered as part of Robins’ Structural Nested Mean Model. Two estimators of the intermediate causal effects, and their standard errors, are presented and...

  6. Does Work Time Flexibility Work? An Empirical Assessment of the Efficiency Effects for German Firms

    OpenAIRE

    Wolf, Elke; Beblo, Miriam

    2004-01-01

    In this paper we assess the impact of flexible work time schedules on firm efficiency using representative establishment data for Germany. Following the approach by Battese and Coelli (1995), we estimate a stochastic production frontier and the determinants of technical efficiency simultaneously. The innovation of our study is that we draw on technical efficiency instead of productivity to appraise the success of flexible working hours. The results indicate that while the use of work time sch...

  7. Timing of Hospice Referral: Assessing Satisfaction While the Patient Receives Hospice Services*

    OpenAIRE

    Adams, Carolyn E.; Bader, Julia; Horn, Kathryn V.

    2009-01-01

    Generally, satisfaction with timing of hospice referral was measured in mortality follow back surveys of patients who died in hospice. In contrast in this study, investigators assessed timing of the hospice referral in patients/families enrolled in hospice for a minimum of two weeks. About 1/3 of patients/families identified it would have been easier if they started hospice earlier. Barriers to early hospice access were associated primarily with access to the healthcare system.

  8. Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house

    Energy Technology Data Exchange (ETDEWEB)

    Beauchemin, Suzanne; MacLean, Lachlan C.W.; Rasmussen, Pat E. (Health Canada); (NRC)

    2012-10-23

    Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 {micro}m house dust samples. In the dust fraction <36 {micro}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.

  9. Proposta para a gestão de estoques de novos produtos: solução do modelo (Q,r) para a distribuição uniforme da demanda e do lead-time de suprimento A proposal for new product inventory management: solution of the (Q,r) inventory model for uniform distribution of demand and and lead-time

    OpenAIRE

    Peter Wanke; Eduardo Saliby

    2005-01-01

    As premissas comumente consideradas nos modelos de estoques - aderência da demanda no lead-time de suprimento à Distribuição Normal, média e desvio-padrão conhecidos e lead-time de suprimento discreto - são freqüentemente irrealistas e podem implicar substanciais distorções na gestão dos estoques de novos produtos, sobretudo nos custos totais e nos indicadores de nível de serviço. Considerando que as empresas simultaneamente estocam os novos produtos e aprendem ao longo do tempo sobre as cara...

  10. Proposta de aplicação da abordagem Quick Response Manufacturing (QRM para a redução do lead time em operações de escritório Proposal for implementation of the approach Quick Response Manufacturing (QRM to reduce lead-time in office operations

    Directory of Open Access Journals (Sweden)

    Andrey Domingues de Lima

    2013-03-01

    Full Text Available A administração eficiente e eficaz do lead time pode criar vantagens competitivas para as empresas. Uma abordagem que possui a preocupação de reduzir o lead time é a Manufatura de Resposta Rápida (QRM - Quick Response Manufacturing. O objetivo do presente trabalho é propor a aplicação de princípios e técnicas do QRM para redução do lead time do processo de orçamentação de uma empresa fabricante de materiais de escrita situada no Brasil. Para tanto, utilizou-se a pesquisa teórico-conceitual e o estudo de caso como procedimentos de pesquisa. Verificou-se que a empresa estudada poderá obter vantagens significativas com a adoção desta abordagem. Os resultados esperados por meio da implantação da proposta mostram uma redução de 38,1% no lead time total do processo de orçamentação da empresa estudada. Esse artigo contribui para maior divulgação e compreensão da abordagem QRM e de seus benefícios.The efficient and effective management of lead-time can create competitive advantages for companies. One approach that has the preoccupation to reduce lead-time is the Quick Response Manufacturing. The aim of this paper is to propose the implementation of principles and techniques of QRM for lead-time reduction in the budgeting process of an enterprise of writing materials (general writing located in Brazil. To this end, the theoretical-conceptual research and case study were used as research procedures. It was found that the studied company could obtain significant benefits by adopting this approach. The expected results through the implementation of the proposal show a decrease of 38.1% in the total lead-time of the budgeting process of the company studied. This paper contributes to a greater dissemination and understanding of the QRM approach and its benefits.

  11. A deposit model for Mississippi Valley-Type lead-zinc ores: Chapter A in Mineral deposit models for resource assessment

    Science.gov (United States)

    Leach, David L.; Taylor, Ryan D.; Fey, David L.; Diehl, Sharon F.; Saltus, Richard W.

    2010-01-01

    This report is a descriptive model of Mississippi Valley-Type (MVT) lead-zinc deposits that presents their geological, mineralogical and geochemical attributes and is part of an effort by the U.S. Geological Survey Mineral Resources Program to update existing models and develop new models that will be used for an upcoming national mineral resource assessment. This deposit modeling effort by the USGS is intended to supplement previously published models for use in mineral-resource and mineral-environmental assessments. Included in this report are geological, geophysical and geochemical assessment guides to assist in mineral resource estimation. The deposit attributes, including grade and tonnage of the deposits described in this report are based on a new mineral deposits data set of all known MVT deposits in the world.

  12. Method of synchronization assessment of rythms in regulatory systems for signal analysis in real time

    OpenAIRE

    Borovkova E.l.; Ishbulatov Yu.M.; Mironov S.A.

    2014-01-01

    A method is proposed for quantitative assessment of the phase synchronization of 0.1 Hz oscillations in autonomic cardiovascular control by photoplethysmogram analysis in real time. The efficiency of the method is shown in the comparison with the results obtained by the previously developed method.

  13. Method of synchronization assessment of rythms in regulatory systems for signal analysis in real time

    Directory of Open Access Journals (Sweden)

    Borovkova E.l.

    2014-09-01

    Full Text Available A method is proposed for quantitative assessment of the phase synchronization of 0.1 Hz oscillations in autonomic cardiovascular control by photoplethysmogram analysis in real time. The efficiency of the method is shown in the comparison with the results obtained by the previously developed method.

  14. The Relationship of Time Orientation with Perceived Academic Performance and Preparation for Assessment in Adolescents

    Science.gov (United States)

    Bowles, Terry

    2008-01-01

    The purpose of this study was to operationalise a model of time orientation and investigate the variability of its factors based on preparation for assessment and perceived academic performance. Responses from 113 male adolescents (mean age = 16.46 years) and 115 female adolescents (mean age = 16.42 years) to items operationalising an expanded…

  15. Assessment of noise in GPS coordinate time series: Methodology and results

    NARCIS (Netherlands)

    Amiri-Simkooei, A.R.; Tiberius, C.C.J.M.; Teunissen, P.J.G.

    2007-01-01

    We propose a methodology to assess the noise characteristics in time series of position estimates for permanent Global Positioning System (GPS) stations. Least squares variance component estimation (LS‐VCE) is adopted to cope with any type of noise in the data. LS‐VCE inherently provides the precisi

  16. Assessment of Smolt Condition for Travel Time Analysis, 1993-1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Robin M; Beeman, John W; VanderKooi, Scott P [US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA

    1999-02-01

    The assessment of smolt condition for travel time analysis (ASCTTA) project provided information on the level of smoltification in Columbia River hatchery and wild salmonid stocks to the Fish Passage Center (FPC), for the primary purpose of in-river management of flows.

  17. Dynamic life-time assessing method for the N1C700 turbine's rotor

    International Nuclear Information System (INIS)

    The N1C700 turbine's rotor subject to different sorts of stress variations was investigated through dynamic life-time assessing method. To obtain the temperature fields at different steam parameters inside the turbine components, a computer code named DENOPAR was developed

  18. Time on Test, Student Motivation, and Performance on the Collegiate Learning Assessment: Implications for Institutional Accountability

    Science.gov (United States)

    Hosch, Braden J.

    2010-01-01

    Using results from the Collegiate Learning Assessment (CLA) administered at Central Connecticut State University, a public Carnegie master's-larger programs university in the Northeast, this study demonstrates time on spent on the test, student motivation, and to a lesser extent the local institutional administration procedures represent…

  19. ASSESSING THE ROLE OF SPIN NOISE IN THE PRECISION TIMING OF MILLISECOND PULSARS

    International Nuclear Information System (INIS)

    We investigate rotational spin noise (referred to as timing noise) in non-accreting pulsars: millisecond pulsars, canonical pulsars, and magnetars. Particular attention is placed on quantifying the strength and non-stationarity of timing noise in millisecond pulsars because the long-term stability of these objects is required to detect nanohertz gravitational radiation. We show that a single scaling law is sufficient to characterize timing noise in millisecond and canonical pulsars while the same scaling law underestimates the levels of timing noise in magnetars. The scaling law, along with a detailed study of the millisecond pulsar B1937+21, leads us to conclude that timing noise is latent in most millisecond pulsars and will be measurable in many objects when better arrival time estimates are obtained over long data spans. The sensitivity of a pulsar timing array to gravitational radiation is strongly affected by any timing noise. We conclude that detection of proposed gravitational wave backgrounds will require the analysis of more objects than previously suggested over data spans that depend on the spectra of both the gravitational wave background and of the timing noise. It is imperative to find additional millisecond pulsars in current and future surveys in order to reduce the effects of timing noise.

  20. Assessment of atmospheric pollution in the vicinity of a tin and lead industry using lichen species Canoparmelia texana

    International Nuclear Information System (INIS)

    This paper examines the viability of using Canoparmelia texana lichen species as a bioindicator of air pollution by radionuclides and rare earth elements (REEs) in the vicinity of a tin and lead industry. The lichen and soil samples were analyzed for uranium, thorium and REEs by instrumental neutron activation analysis. The radionuclides 226Ra, 228Ra and 210Pb were determined either by Gamma-ray spectrometry (GRS) (soils) or by radiochemical separation followed by gross alpha and beta counting using a gas flow proportional counter (lichens). The lichens samples concentrate radionuclides (on the average 25-fold higher than the background for this species) and REEs (on the average 10-fold higher), therefore they can be used as a fingerprint of contamination by the operation of the tin industry.

  1. Assessment of atmospheric pollution in the vicinity of a tin and lead industry using lichen species Canoparmelia texana

    Energy Technology Data Exchange (ETDEWEB)

    Leonardo, Lucio, E-mail: lucioleo@ipen.br [Laboratorio de Radiometria Ambiental, Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2242-Sao Paulo, CEP 05508 000 (Brazil); Mazzilli, Barbara Paci; Damatto, Sandra Regina [Laboratorio de Radiometria Ambiental, Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2242-Sao Paulo, CEP 05508 000 (Brazil); Saiki, Mitiko [Laboratorio de Analise por Ativacao Neutronica, Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2242-Sao Paulo, CEP 05508 000 (Brazil); Barros de Oliveira, Sonia Maria [Departamento de Geologia Sedimentar e Ambiental, Universidade de Sao Paulo, SP (Brazil)

    2011-10-15

    This paper examines the viability of using Canoparmelia texana lichen species as a bioindicator of air pollution by radionuclides and rare earth elements (REEs) in the vicinity of a tin and lead industry. The lichen and soil samples were analyzed for uranium, thorium and REEs by instrumental neutron activation analysis. The radionuclides {sup 226}Ra, {sup 228}Ra and {sup 210}Pb were determined either by Gamma-ray spectrometry (GRS) (soils) or by radiochemical separation followed by gross alpha and beta counting using a gas flow proportional counter (lichens). The lichens samples concentrate radionuclides (on the average 25-fold higher than the background for this species) and REEs (on the average 10-fold higher), therefore they can be used as a fingerprint of contamination by the operation of the tin industry.

  2. Relationships of video assessments of touching and mouthing behaviors during outdoor play in urban residential yards to parental perceptions of child behaviors and blood lead levels.

    Science.gov (United States)

    Ko, Stephen; Schaefer, Peter D; Vicario, Cristina M; Binns, Helen J

    2007-01-01

    Childrens' touching and mouthing behaviors during outdoor play in urban residential yards were measured using video observations. Descriptions were made of childrens' outdoor residential play environments. Behaviors assessed were used to examine (1) validity of parental responses to questions on childrens' oral behaviors and outdoor play and (2) relationships of mouthing behaviors to blood lead levels (BLLs). Thirty-seven children aged 1-5 years were recruited for 2 h of video recording in their yard and blood lead measurement. Video assessments included hourly rates of hand touches to ground/walking-level surfaces (cement/stone/steel, porch floor/steps, grass, and bare soil) and oral behaviors. Parental questionnaires assessed their child's outdoor activities, behaviors, and home environment. The children were: mean 39 months; 51% male; 89% Hispanic; and 78% Medicaid or uninsured. Twenty-two children had a blood lead measured (mean 6 microg/dl). During taping, all children had access to cement, 92% to grass, 73% to bare soil, and 59% to an open porch. Children had frequent touching and mouthing behaviors observed (median touches/h: touches to surfaces 81; hand-to-mouth area (with and without food) 26; hand-in-mouth 7; and object-in-mouth 17). Blood lead was directly correlated with log-transformed rates of hand-in-mouth (Pearson's correlation, r=0.564, n=22, P=0.006) and object-in-mouth (Pearson's correlation, r=0.482, n=22, P=0.023) behaviors. Parental questionnaire responses did not accurately reflect childrens' observed oral behaviors, play habits, or play environment. These data confirm the direct relationship between hand-to-mouth activities and BLLs and fail to validate parental perceptions of their child's mouthing behaviors or outdoor play environment. PMID:16941017

  3. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    Science.gov (United States)

    Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

    2014-01-01

    Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p Lake Tanganyika in spite of the development of mining and smelting operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions of sediment at the sites differed spatially, indicating that the Pb (and other trace elements by association) originated from different natural sources at the two locations.

  4. Medição e controle do tempo de atravessamento em um sistema de manufatura Measurement and control of lead-time in a manufacturing system

    Directory of Open Access Journals (Sweden)

    Miguel Afonso Sellitto

    2008-04-01

    Full Text Available Este artigo apresenta um método para a medição do tempo de atravessamento e do inventário em processo em manufatura. A medição foi usada em processo de controle organizacional de manufatura, cuja variável controlada foi o tempo de atravessamento de ordens. Tal controle pode ser útil em estratégias de manufatura em que a competição é baseada no uso do tempo, a TBC (time-based competition. Apresentou-se o método de medição, que inclui elementos da teoria das filas, e considerações para a simplificação de arranjos produtivos de manufatura. Para testar e refinar o método, estudou-se um caso em manufatura calçadista. Foram coletados dados de remessas e obtido, por análise estatística e simulação computacional, o comportamento da variável aleatória tempo de atravessamento de remessas. Como a medição foi inferior ao objetivo de desempenho, partiu-se para o controle, fazendo um diagnóstico que apontou efeitos indesejáveis observados que foram endereçados por ações corretivas implementadas. Para verificar a eficácia das ações, nova coleta foi feita. Desta vez, o objetivo de desempenho das entregas foi atendido, fechando um ciclo de controle. Os resultados foram discutidos, chegando-se a conclusões e alternativas de continuidade.This paper presents a method for the measurement of the lead-time and work-in-process in manufacturing. The measurement was used in an organizational control process in manufacturing, in which the controlled variate was the order lead-time. This kind of control can be useful in manufacture strategies formulated to compete in TBC (time-based competition. We presented the method, who includes elements from the queuing theory, and concerns about simplifying complex manufacturing arrays, in order to facilitate the analysis. In order to test and refine the method, we studied a case in a footwear manufacture system. We collected data from orders and, by statistical techniques and computational

  5. Assessing the Mobility of Lead, Copper and Cadmium in a Calcareous Soil of Port-au-Prince, Haiti

    Directory of Open Access Journals (Sweden)

    Urbain Fifi

    2013-11-01

    Full Text Available The presence of heavy metals in the environment constitutes a potential source of both soil and groundwater pollution. This study has focused on the reactivity of lead (Pb, copper (Cu and Cadmium (Cd during their transfer in a calcareous soil of Port-au-Prince (Haiti. Kinetic, monometal and competitive batch tests were carried out at pH 6.0. Two simplified models including pseudo-first-order and pseudo-second-order were used to fit the experimental data from kinetics adsorption batch tests. A good fit of these data was found with pseudo-second-order kinetic model which indicates the applicability of this model to describe the adsorption rates of these metals on the soil. Monometal batch tests indicated that both Langmuir and Freundlich models allowed a good fit for experimental data. On the basis of the maximum adsorption capacity (qmax, the order affinity of Pb, Cu and Cd for the studied soil was Pb2+ > Cu2+ > Cd2+. Competitive sorption has proved that the competition between two or several cations on soils for the same active sites can decrease their qmax. These results show that, at high metal concentrations, Cd may pose more threat in soils and groundwater of Port-au-Prince than Pb and Cu.

  6. Self-Motion Perception: Assessment by Real-Time Computer Generated Animations

    Science.gov (United States)

    Parker, Donald E.

    1999-01-01

    Our overall goal is to develop materials and procedures for assessing vestibular contributions to spatial cognition. The specific objective of the research described in this paper is to evaluate computer-generated animations as potential tools for studying self-orientation and self-motion perception. Specific questions addressed in this study included the following. First, does a non- verbal perceptual reporting procedure using real-time animations improve assessment of spatial orientation? Are reports reliable? Second, do reports confirm expectations based on stimuli to vestibular apparatus? Third, can reliable reports be obtained when self-motion description vocabulary training is omitted?

  7. Distribution of cadmium, mercury, and lead in different body parts of Baltic herring (Clupea harengus) and perch (Perca fluviatilis): Implications for environmental status assessments

    International Nuclear Information System (INIS)

    Highlights: • Good Environmental Status (GES) is assessed based on whole fish body concentrations. • Heavy metals were analyzed in different parts of herring and perch body. • Conversion factors between these tissues were calculated and applied to assess GES. • GES in herring improved compared to assessments using muscle/liver concentrations. • Status assessments must reflect whole fish concentrations, not only sampled tissues. -- Abstract: For heavy metals, quality standards indicating good environmental status are designed to evaluate concentrations in the whole fish body, whereas monitoring of metals is often conducted using muscle or liver tissue. As most metals accumulate at different rates in different parts of fish, data should be adjusted to reflect whole fish body concentrations; however, this requires knowledge on distribution of metal concentrations within fish. Here, concentrations of cadmium, mercury, and lead were analyzed in the liver, muscle and whole fish of herring and perch to create conversion factors for transformation of heavy metal concentrations between these tissues. Species-specific accumulation of metals between muscle, liver, and whole fish were observed. Relationships between different tissues were used to recalculate data from monitoring programs in the Baltic Sea region. Based on whole fish concentrations, environmental status for cadmium and mercury in herring improved compared to assessments based on muscle or liver concentrations alone

  8. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chang Hyun; You, Young Woo; Cho, Jae Seon; Huh, Chang Wook; Kim, Do Hyoung; Kim, Ju Youl; Kim, Yoon Ik; Yang, Hui Chang; Park, Kang Min [Seoul National Univ., Seoul (Korea, Republic of)

    1998-03-15

    The objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Internal(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plant safety. In this study, the survey about the assessment methodologies, modelings and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. The sensitivity analyses about the failure factors of the components are performed in the bases of the and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code. The qualitative assessment for the STI/AOR of RPS/ESFAS assured safety the most important system in the nuclear power plant are performed.

  9. A Study of FR Video Quality Assessment of Real Time Video Stream

    Directory of Open Access Journals (Sweden)

    Yuan Fang

    2012-06-01

    Full Text Available To assess the real-time transmission video’s quality, this paper persents a approach which used FR video quality assessment (VQA model to satisfy the objective and subjective measurement requirement. If we want to get the reference video in the measuring terminal and to make a assessment, there are two problems which are how to certain the reference video frame and how to make the objective score close to the subject assessment. We present in this paper a novel method of computing the order number of the video frame in the test point. In order to establish the relationship between the objective distortion and the subjective score, we used the “best-fit” regressed curve model and the BP neural network to describe prediction formula. This work is the mainly aim to get the high accurency assessment results with the human subjective feeling. So we select huge video sources for testing and training. The experimental results show that the proposed approach is suit to assess the video quality using FR model and the converted subjective score is available.

  10. A study on assessment methodology of surveillance test interval and Allowed Outage Time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Ryu, Yeong Woo; Cho, Jae Seon; Heo, Chang Wook; Kim, Do Hyeong; Kim, Joo Yeol; Kim, Yun Ik; Yang, Hei Chang [Seoul National Univ., Seoul (Korea, Republic of)

    1997-07-15

    Objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. In the second year of this study, the sensitivity analyses about the failure factors of the components are performed in the bases of the assessment methodologies of the first study, the interaction modeling of the STI and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code.

  11. Determining lead sources in Mexico using the lead isotope ratio

    Directory of Open Access Journals (Sweden)

    Chaudhary-Webb Madhu

    2003-01-01

    Full Text Available OBJECTIVE: Lead poisoning can, in some cases, be traced to a specific route or source of exposure on the basis of the individual's blood lead isotope ratio. To assess the major source of lead exposure among women residing in Mexico City, we compared blood, ceramic, and gasoline lead isotope ratios. MATERIAL AND METHODS: The study population, randomly selected from participants of a large trial, (1/1996-12/1996 comprised of 16 women whose lead levels exceeded 10 µg/dl and who reported using lead-glazed ceramics. Lead isotope ratios were performed on a Perkin Elmer 5000 Inductively Coupled Plasma Mass Spectrometer (ICP-MS interfaced with a Perkin Elmer HGA-600MS Electrothermal Vaporization System (ETV. RESULTS: The isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb of both the blood specimens and their corresponding ceramic specimens were highly correlated, with r=0.9979, r²=0.9958, r=0.9957, r²=0.9915 and r=0.9945, r²=0.9890 values for the three isotope ratios, respectively, suggesting that the lead exposure most likely resulted from the use of these ceramic. Measurements of lead isotope ratios from leaded gasoline in use at the time of blood sampling, differed from those in blood and ceramics. CONCLUSIONS: Determining lead isotope ratios can be an efficient tool to identify a major source of lead exposure and to support the implementation of public health prevention and control measures.

  12. Office workers' objectively assessed total and prolonged sitting time: Individual-level correlates and worksite variations.

    Science.gov (United States)

    Hadgraft, Nyssa T; Healy, Genevieve N; Owen, Neville; Winkler, Elisabeth A H; Lynch, Brigid M; Sethi, Parneet; Eakin, Elizabeth G; Moodie, Marj; LaMontagne, Anthony D; Wiesner, Glen; Willenberg, Lisa; Dunstan, David W

    2016-12-01

    Sedentary behavior is highly prevalent in office-based workplaces; however, few studies have assessed the attributes associated with this health risk factor in the workplace setting. This study aimed to identify the correlates of office workers' objectively-assessed total and prolonged (≥ 30 min bouts) workplace sitting time. Participants were 231 Australian office workers recruited from 14 sites of a single government employer in 2012-13. Potential socio-demographic, work-related, health-related and cognitive-social correlates were measured through a self-administered survey and anthropometric measurements. Associations with total and prolonged workplace sitting time (measured with the activPAL3) were tested using linear mixed models. Worksites varied significantly in total workplace sitting time (overall mean [SD]: 79% [10%] of work hours) and prolonged workplace sitting time (42% [19%]), after adjusting for socio-demographic and work-related characteristics. Organisational tenure of 3-5 years (compared to tenure > 5 years) was associated with more time spent in total and prolonged workplace sitting time, while having a BMI categorised as obese (compared to a healthy BMI) was associated with less time spent in total and prolonged workplace sitting time. Significant variations in sitting time were observed across different worksites of the same employer and the variation remained after adjusting for individual-level factors. Only BMI and organisational tenure were identified as correlates of total and prolonged workplace sitting time. Additional studies are needed to confirm the present findings across diverse organisations and occupations. PMID:27413681

  13. Growth rates and interface shapes in germanium and lead tin telluride observed in-situ, real-time in vertical Bridgman furnaces

    Science.gov (United States)

    Barber, P. G.; Berry, R. F.; Debnam, W. J.; Fripp, A. L.; Woodell, G.; Simchick, R. T.

    1995-01-01

    Using the advanced technology developed to visualize the melt-solid interface in low Prandtl number materials, crystal growth rates and interface shapes have been measured in germanium and lead tin telluride semiconductors grown in vertical Bridgman furnaces. The experimental importance of using in-situ, real time observations to determine interface shapes, to measure crystal growth rates, and to improve furnace and ampoule designs is demonstrated. The interface shapes observed in-situ, in real-time were verified by quenching and mechanically induced interface demarcation, and they were also confirmed using machined models to ascertain the absence of geometric distortions. Interface shapes depended upon the interface position in the furnace insulation zone, varied with the nature of the crystal being grown, and were dependent on the extent of transition zones at the ends of the ampoule. Actual growth rates varied significantly from the constant translation rate in response to the thermophysical properties of the crystal and its melt and the thermal conditions existing in the furnace at the interface. In the elemental semiconductor germanium the observed rates of crystal growth exceeded the imposed translation rate, but in the compound semiconductor lead tin telluride the observed rates of growth were less than the translation rate. Finally, the extent of ampoule thermal loading influenced the interface positions, the shapes, and the growth rates.

  14. Effects of arsenic and cadmium on bioaccessibility of lead in spiked soils assessed by Unified BARGE Method.

    Science.gov (United States)

    Xia, Qing; Peng, Cheng; Lamb, Dane; Kader, Mohammed; Mallavarapu, Megharaj; Naidu, Ravi; Ng, Jack C

    2016-07-01

    The bioaccessibility of lead (Pb) in contaminated soils has been extensively studied, including the influence of soil properties on Pb bioaccessibility. However, little is known about the effects of other metals/metalloid, such as arsenic (As), cadmium (Cd) on the bioaccessibility of Pb, i.e. whether As or Cd could increase or decrease the solubility of Pb in human gastrointestinal tract when Pb-contaminated soil and As-contaminated (or Cd-contaminated) soil are ingested simultaneously. Furthermore, it is far from clear that if soil property could make a difference to these effects. In this study, seven types of soils were collected in Australia and spiked with As, Cd or Pb. Gastric bioaccessibility of Pb ranged from 44 ± 0.9% to 100 ± 6.7% whilst intestinal bioaccessibility dropped to 1 ± 0.2% to 36 ± 1.7%. Statistical analysis shows total Pb in soil was the most significant controller for bioaccessible Pb. Effects of As and Cd on the bioaccessibility of Pb in simulated human digestive system were studied by mixing As-spiked soil (or Cd-spiked soil) with Pb-spiked soil of the same type during bioaccessibility test. Results reveal that neither As nor Cd had impact on Pb bioaccessibility, which indicates when As, Cd and Pb aged in soils separately, they may behave independently in the bioaccessibility measuring system. This finding can be part of evidence to assume additive effect when it comes to estimate the bioaccessibility of mixtures of independently-aged As and Pb (or Cd and Pb) in soils. PMID:27062001

  15. Assessment of groundwater quality for irrigation: a case study from Bandalamottu lead mining area, Guntur District, Andhra Pradesh, South India

    Science.gov (United States)

    Nagaraju, A.; Sunil Kumar, K.; Thejaswi, A.

    2014-12-01

    Quality of water resources in the Bandalamottu area of Guntur District of Andhra Pradesh in South India is facing a serious challenge due to Pb mining. Therefore, 40 groundwater samples were collected from this area to assess their hydrogeochemistry and suitability for irrigation purposes. The groundwater samples were analyzed for distribution of chemical elements Ca2+, Mg2+, Na+, K+, HCO3 -, CO3 2-, F-, Cl-, and SO4 2-. It also includes pH, electrical conductivity, total hardness, non-carbonate hardness and total alkalinity. The parameters, such as sodium absorption ratio (SAR), adjusted SAR, sodium percentage, potential salinity, residual sodium carbonate, non-carbonate hardness, Kelly's ratio, magnesium ratio, permeability index, indices of base exchange (IBE) and Gibbs ratio were also calculated. The major hydrochemical facieses were Ca-HCO3, Ca-Na-HCO3 and Ca-Mg-Cl types. The result of saturation index calculated by Visual MINTEQ software combined with Gibbs diagram and IBE findings indicate that, dolomite and calcite dissolution and reverse ion exchange can be a major process controlling the water chemistry in the study area. The results also showed that the salinity (85 %, C3 class) and alkalinity due to high concentration of HCO3 - and CO3 - and low Ca:Mg molar ratio (97.5 %, <1), are the major problems with water for irrigation usage. As a result, the quality of the groundwater is not suitable for sustainable crop production and soil health without appropriate remediation.

  16. Assessment of Smolt Condition for Travel Time Analysis, 1991-1992 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Maule, Alec G.; Beeman, John W.; Schrock, Robin M. (Seattle National Fishery Research Center, Columbia River Field Station, Cook, WA)

    1994-05-01

    Regression techniques were used to determine the effects of several biotic and abiotic variables on the migration rates of juvenile spring chinook salmon and steelhead in the Columbia and Snake rivers. Comparisons of the effects of river flow and smoltification, assessed using gill Na{sup +}-K{sup +} ATPase activity, were of primary interest. Day of the year, water temperature, change in flow, condition factor, and fork length were also considered as independent variables. Groups of fish were sampled to assess smoltification 2-3 times per week during the spring outmigrations during 1989-1992. These groups were assumed to be representative of other fish which were PIT-tagged and released as a part of the Smolt Monitoring Program in the Columbia Basin. River flow, gill ATPase activity, condition factor, water temperature, and change in flow were significant variables in regressions predicting the time for juvenile spring chinook salmon to travel between specific points (travel time), whereas river flow was the only significant contributor to models describing travel times of steelhead. Predicted travel times of wild steelhead were shorter than those of hatchery steelhead. River flow was the only variable common to all regression equations. Based on the characteristic, changes in river flow would be the most logical means to decrease travel times of both juvenile spring chinook salmon and steelhead in the Columbia and Snake rivers.

  17. Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda

    International Nuclear Information System (INIS)

    The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0±2.3 to 64.6±11.7 mg/kg Pb, 78.4±18.4 to 265.6±63.2 mg/kg Zn, and 0.8±0.13 to 1.40±0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas

  18. Heavy metal pollution and ecological risk assessment of the paddy soils near a zinc-lead mining area in Hunan.

    Science.gov (United States)

    Lu, Sijin; Wang, Yeyao; Teng, Yanguo; Yu, Xuan

    2015-10-01

    Soil pollution by Cd, Hg, As, Pb, Cr, Cu, and Zn was characterized in the area of the mining and smelting of metal ores at Guiyang, northeast of Hunan Province. A total of 150 topsoil (0-20 cm) samples were collected in May 2012 with a nominal density of one sample per 4 km(2). High concentrations of heavy metals especially, Cd, Zn, and Pb were found in many of the samples taken from surrounding paddy soil, indicating a certain extent of spreading of heavy metal pollution. Sequential extraction technique and risk assessment code (RAC) were used to study the mobility of chemical forms of heavy metals in the soils and their ecological risk. The results reveal that Cd represents a high ecological risk due to its highest percentage of the exchangeable and carbonate fractions. The metals of Zn and Cu pose a medium risk, and the rest of the metals represent a low environmental risk. The range of the potential ecological risk of soil calculated by risk index (RI) was 123.5~2791.2 and revealed a considerable-high ecological risk in study area especially in the neighboring and surrounding the mining activities area. Additionally, cluster analyses suggested that metals such as Pb, As, Hg, Zn, and Cd could be from the same sources probably related to the acidic drainage and wind transport of dust. Cluster analysis also clearly distinguishes the samples with similar characteristics according to their spatial distribution. The results could be used during the ecological risk screening stage, in conjunction with total concentrations and metal fractionation values to better estimate ecological risk. PMID:26373302

  19. Variability of procedural blanks leads to greater uncertainty in assessing detection limits for the measurement of polonium-210

    International Nuclear Information System (INIS)

    Low-level measurements of 210Po using alpha spectrometry with a 209Po tracer have been conducted at the Environmental Research Institute of the Supervising Scientist (eriss) for many years, on samples with a range of activity concentrations spanning several orders of magnitude. These samples originated from a wide range of research and monitoring projects, and included a wide variety of traditional foods consumed by the indigenous population in Australia's Northern Territory. Assessment of instrument blank and analyte blank data from these measurements collected over a period of 8 years was conducted. Instrumental blank data for 210Po and 209Po generally followed a normal distribution, whereas analyte blank data for 210Po followed a lognormal distribution. Instrumental blank data for 209Po indicated an increasing trend, indicative of a low level of polonium volatilisation from prepared sources. Lower limits of detection, including the critical limit, detection limit and quantification limit have been calculated. The critical limit ranges from 12 to 37 counts per day. Detection and quantification limits range from 0.18 to 0.33 mBq and 2.3 to 3.6 mBq for a 4-day count, with an assumed mean chemical recovery of 53 %. These limits are relatively high for alpha spectrometric techniques due to the high variability of the analyte blank signal and non-normal distribution for 210Po. Native plant species have relatively low activity concentrations of 210Po in their edible fruits and the amount of sample that should be used for analysis to ensure 90 % of fruit samples analysed reach the specified quantification limit was 11 g. (author)

  20. Assessment of soil contamination. Measuring devices for arsenic, berryllium, lead, cadmium, mercury and selenium. Wirkung von Bodenkontaminationen. Messlatten fuer Arsen, Beryllium, Blei, Cadmium, Quecksilber und Selen

    Energy Technology Data Exchange (ETDEWEB)

    Blumenbach, D.; Kloke, A.; Luehr, H.P.

    1991-12-01

    To assess soil contamination with respect to the suitability of the site concerned, it is essential to obtain knowledge of the relationship between soil contamination levels and the effect of the contaminants on a targets meriting protection (e.g. human beings, plants, soil organisms). In this final report, data obtained from literature on the inorganic pollutants arsenic, lead, cadmium, mercury, selenium and beryllium are compiled, and for selected targets an overview is given of the damage occurring at the various concentration levels studies. The present data, together with information on the envisaged use of the site and on soil properties influencing the pollutant's transport to the protected target, can be used to assess soil quality. Threshold values for use in decision-making cannot be derived directly from the presented data, as such data can only convey a picture of the range of the harmful concentrations given in the literature. (orig.).

  1. Lead poisoning

    Science.gov (United States)

    ... free solder, lead is still found in some modern faucets. Soil contaminated by decades of car exhaust ... NOT store wine, spirits, or vinegar-based salad dressings in lead crystal decanters for long periods of ...

  2. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  3. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    International Nuclear Information System (INIS)

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations

  4. Relational Leading

    DEFF Research Database (Denmark)

    Larsen, Mette Vinther; Rasmussen, Jørgen Gulddahl

    2015-01-01

    This first chapter presents the exploratory and curious approach to leading as relational processes – an approach that pervades the entire book. We explore leading from a perspective that emphasises the unpredictable challenges and triviality of everyday life, which we consider an interesting......, relevant and realistic way to examine leading. The chapter brings up a number of concepts and contexts as formulated by researchers within the field, and in this way seeks to construct a first understanding of relational leading....

  5. Assessment of Time-Lapse in Visible and Thermal Face Recognition

    Czech Academy of Sciences Publication Activity Database

    Farokhi, S.; Shamsuddin, S. M.; Flusser, Jan; Sheikh, U. U.

    Kuala Lumpur : WASET, 2012, s. 578-583. ISSN 2010-376X. [International Conference on Machine Learning and Pattern Recognition ICMLPR'12. Kuala Lumpur (MY), 19.02.2012-21.02.2012] R&D Projects: GA ČR GAP103/11/1552 Keywords : Face recognition * Zernike moments * infrared imaging Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2012/ZOI/flusser-assessment of time-lapse in visible and thermal face recognition.pdf

  6. An Assessment Of Time Variation In Solid And Hollow Floor Construction In Lagos State

    OpenAIRE

    Olumide, Afolarin Adenuga; Sotunbo, Gboyega

    2014-01-01

    The choice of construction method employed for constructing suspended slabs in buildings tend to impact significantly on the delivery time of building project. Thus, this study aims at assessing the impact of various construction methods on duration for constructing hollow and solid floor slabs in buildings in Lagos State, Nigeria. The research design for this study was a survey design approach and the populations of the study were professionals involved in construction projects; Archit...

  7. Task completion time: Objective tool for assessment of technical skills in laparoscopic simulator for urology trainees

    OpenAIRE

    Mishra, Shashi K.; Ganpule, A.; Kurien, A; Muthu, V.; Desai, Mahesh R.

    2008-01-01

    Context: Laparoscopic surgical simulation is a valuable training tool for urology trainees. Aims: We assessed the validity of task completion time (TCT) as an objective tool for practicing and acquiring technical skills in a simulated laparoscopy environment. Materials and Methods: Fifteen participants comprising postgraduate urology trainees from first to third year (n = 12), urology fellow (n = 1) and consultants (n = 2) underwent basic laparoscopic training on the “Beetle Universal” endotr...

  8. A real-time assessment of the effect of exercise in chronic fatigue syndrome

    OpenAIRE

    Yoshiuchi, Kazuhiro; Cook, Dane B.; Ohashi, Kyoko; Kumano, Hiroaki; Kuboki, Tomifusa; Yamamoto, Yoshiharu; Natelson, Benjamin H.

    2007-01-01

    Patients with chronic fatigue syndrome (CFS) report substantial symptom worsening after exercise. However, the time course over which this develops has not been explored. Therefore, the objective of this study was to investigate the influence of exercise on subjective symptoms and on cognitive function in CFS patients in natural settings using a computerized ecological momentary assessment method, which allowed us to track the effects of exercise within and across days. Subjects were 9 female...

  9. Multivariate error assessment of response time histories method for dynamic systems

    Institute of Scientific and Technical Information of China (English)

    Zhen-fei ZHAN; Jie HU; Yan FU; Ren-Jye YANG; Ying-hong PENG; Jin QI

    2012-01-01

    In this paper,an integrated validation method and process are developed for multivariate dynamic systems.The principal component analysis approach is used to address multivariate correlation and dimensionality reduction,the dynamic time warping and correlation coefficient are used for error assessment,and the subject matter experts (SMEs)' opinions and principal component analysis coefficients are incorporated to provide the overall rating of the dynamic system.The proposed method and process are successfully demonstrated through a vehicle dynamic system problem.

  10. Assessing Pulsar Timing Array Sensitivity to Gravitational Wave Bursts with Memory

    CERN Document Server

    Madison, D R; Chatterjee, S

    2014-01-01

    Highly energetic astrophysical phenomena like supermassive black hole binary (SMBHB) mergers are predicted to emit prodigious amounts of gravitational waves (GWs). An anticipated component of the gravitational waveform known as "memory" is permanent and non-oscillatory. For SMBHB mergers, the memory is created primarily during the most violent moments of the inspiral immediately preceding the final plunge and ring-down when the strongest gravitational fields are at work and the non-linearities of general relativity are most pronounced. The essentially time-domain nature of memory makes it forbiddingly difficult to detect with ground based GW detectors, leaving pulsar timing array (PTA) experiments as the most promising means by which it may be detected and studied. In this paper, we discuss how GW bursts with memory (BWMs) influence pulsar timing experiments and develop methods to assess how sensitive modern timing efforts are to such GW events. We discuss how PTA searches for BWMs can be used to constrain th...

  11. Assessment of the accuracy of real-time continuous glucose monitoring system and its correlated factors

    Institute of Scientific and Technical Information of China (English)

    洛佩

    2014-01-01

    Objective To assess the factors that influence the accuracy of real-time continuous glucose monitoring system(RT-CGM).Methods A total of 79 diabetic patients wore RT-CGM for three days continuously while calibrating by interphalangeal glucose values 4-8 times a day.We counted matching rate of interphalangeal glucose values and RT-CGM probe value,and analyzed correlation of the matching rate with MAGE,SDBG,MBG,AUC10,AUC3.9,and NGE by Pearson correlation analysis and multiple linear

  12. Approaches to assessment in time-limited Mentalization-Based Therapy for Children (MBT-C).

    Science.gov (United States)

    Muller, Nicole; Midgley, Nick

    2015-01-01

    In this article we describe our clinical approach to assessment, formulation and the identification of a therapeutic focus in the context of time-limited Mentalization-Based Treatment for Children (MBT-C) aged between 6 and 12. Rather than seeing the capacity to mentalize as a global construct, we set out an approach to assessing the developmental 'building blocks' of the capacity to mentalize the self and others, including the capacity for attention regulation, emotion regulation, and explicit mentalization. Assessing the child's strengths and vulnerabilities in each of these domains provides a more nuanced picture of the child's mentalizing capacities and difficulties, and can provide a useful approach to case formulation. The article sets out an approach to assessment that includes a consideration of mentalizing strengths and difficulties in both the child and the parents, and shows how this can be used to help develop a mutually agreed treatment focus. A clinical vignette illustrates the approach taken to assessment and connects it to routine clinical practice. PMID:26283994

  13. Real time and in situ determination of lead in road sediments using a man-portable laser-induced breakdown spectroscopy analyzer

    International Nuclear Information System (INIS)

    In situ, real time levels of lead in road sediments have been measured using a man-portable laser-induced breakdown spectroscopy analyzer. The instrument consists of a backpack and a probe housing a Q-switched Nd:YAG laser head delivering 50 mJ per pulse at 1064 nm. Plasma emission was collected and transmitted via fiber optic to a compact cross Czerny-Turner spectrometer equipped with a linear CCD array allocated in the backpack together with a personal computer. The limit of detection (LOD) for lead and the precision measured in the laboratory were 190 μg g-1 (calculated by the 3σ method) and 9% R.S.D. (relative standard deviation), respectively. During the field campaign, averaged Pb concentration in the sediments were ranging from 480 μg g-1 to 660 μg g-1 depending on the inspected area, i.e. the entrance, the central part and the exit of the tunnel. These results were compared with those obtained with flame-atomic absorption spectrometry (flame-AAS). The relative error, expressed as [100(LIBS result - flame AAS result)/(LIBS result)], was approximately 14%

  14. A proposed method for assessing in-core flux detector dynamic compensation adequacy over a range of trip times

    International Nuclear Information System (INIS)

    A simple method is proposed for testing the adequacy of in-core flux detector dynamic compensation, for a range of event times, using measured detector responses following a trip. The proposed approach constructs a target fuel power curve versus time for a given trip, based on the reactor power history prior to the trip. A simplified standard contribution for the core post-trip delayed neutron rundown, based on simulated SDS1 and SDS2 trips and including delays in detector response to this flux, is then subtracted from the measured detector responses. These flux rundowns have a time variation common to all detectors, with magnitudes varying from detector to detector. This allows location-related differences in the contribution of flux rundown to the detector responses to be accounted for relatively simply. The compensation design-basis is that the compensated detector signal should lead fuel power at all times. The test for adequacy of the dynamic compensation compares the corrected compensated detector signals against the target fuel power curve for that trip, from 3 seconds to about 2 hours. The 3-second start-point is far enough from the trip to minimize differences in trip timing and SOR insertion effects, yet sufficient to approximately test compensation adequacy for fast events. The 2 hour end-point is sufficient to assess the adequacy of the maximum 2500 second compensator term. It is normal to find detector-to-detector differences in dynamic response. Since there are significant operational reasons for having the same compensator terms for all detectors in a shutdown system, these differences are typically allowed for by an uncertainty term in overpower protection (ROP) setpoint analyses. The assessment of the compensation reflects this background. The average rundown-corrected response over all detectors in a shutdown system is compared against the target fuel power curve to assess whether the compensator gains for that SDS need adjustment. For individual

  15. Application and Assessment of Extension of Time Claim: Findings of Case Studies Conducted in Malaysia

    Directory of Open Access Journals (Sweden)

    M.S. Mohd Danuri,

    2006-12-01

    Full Text Available It is a common phenomenon for construction projects to have applications for extension of time. Many problems are encountered in practice in the application and preparation of extension of time claims. A study was conducted to identify the main problems encountered in the application and assessment of extension of time claim in selected construction projects in Malaysia. Three (3 case studies have been used 10 investigate the extension of time issues. Findings from the study revealed that local contractors usually fail to comply with the contract procedural requirements to submit timely notification of delay and have difficulty in demonstrating their entitlement for extension of time. The main problem faced by contract administrators is that contractors tend to "inflate" their extension of time entitlement with the intention to maximise their claims. Adherence to the agreed procedure in preparing and evaluating of delay claims and the implementation of a set of agreed standardised delay analysis may help to minimize the frequency and impact of such problems.

  16. Cadmium, lead, and chromium in large game: a local-scale exposure assessment for hunters consuming meat and liver of wild boar.

    Science.gov (United States)

    Danieli, P P; Serrani, F; Primi, R; Ponzetta, M P; Ronchi, B; Amici, A

    2012-11-01

    Heavy metals are ubiquitous in soil, water, and air. Their entrance into the food chain is an important environmental issue that entails risks to humans. Several reports indicate that game meat can be an important source of heavy metals, particularly because of the increasing consumption of game meat, mainly by hunters. We performed an exposure assessment of hunters and members of their households, both adults and children, who consumed wild boar (WB) meat and offal. We estimated the amount of cadmium, lead, and chromium in the tissues of WB hunted in six areas within Viterbo Province (Italy) and gathered data on WB meat and offal consumption by conducting specific diet surveys in the same areas. The exposure to cadmium, lead, and chromium was simulated with specifically developed Monte Carlo simulation models. Cadmium and lead levels in WB liver and meat harvested in Viterbo Province (Italy) were similar to or lower than the values reported in other studies. However, some samples contained these metals at levels greater then the EU limits set for domestic animals. The chromium content of meat or liver cannot be evaluated against any regulatory limit, but our results suggest that the amounts of this metal found in WB products may reflect a moderate environmental load. Our survey of the hunter population confirmed that their consumption of WB meat and liver was greater than that of the general Italian population. This level of consumption was comparable with other European studies. Consumption of WB products contributes significantly to cadmium and lead exposure of both adults and children. More specifically, consumption of the WB liver contributed significantly to total cadmium and lead exposure of members of the households of WB hunters. As a general rule, liver consumption should be kept to a minimum, especially for children living in these hunter households. The exposure to chromium estimated for this population of hunters may be considered to be safe. However

  17. Validating the Accuracy of Reaction Time Assessment on Computer-Based Tablet Devices.

    Science.gov (United States)

    Schatz, Philip; Ybarra, Vincent; Leitner, Donald

    2015-08-01

    Computer-based assessment has evolved to tablet-based devices. Despite the availability of tablets and "apps," there is limited research validating their use. We documented timing delays between stimulus presentation and (simulated) touch response on iOS devices (3rd- and 4th-generation Apple iPads) and Android devices (Kindle Fire, Google Nexus, Samsung Galaxy) at response intervals of 100, 250, 500, and 1,000 milliseconds (ms). Results showed significantly greater timing error on Google Nexus and Samsung tablets (81-97 ms), than Kindle Fire and Apple iPads (27-33 ms). Within Apple devices, iOS 7 obtained significantly lower timing error than iOS 6. Simple reaction time (RT) trials (250 ms) on tablet devices represent 12% to 40% error (30-100 ms), depending on the device, which decreases considerably for choice RT trials (3-5% error at 1,000 ms). Results raise implications for using the same device for serial clinical assessment of RT using tablets, as well as the need for calibration of software and hardware. PMID:25612627

  18. On the Assessment of Acoustic Scattering and Shielding by Time Domain Boundary Integral Equation Solutions

    Science.gov (United States)

    Hu, Fang Q.; Pizzo, Michelle E.; Nark, Douglas M.

    2016-01-01

    Based on the time domain boundary integral equation formulation of the linear convective wave equation, a computational tool dubbed Time Domain Fast Acoustic Scattering Toolkit (TD-FAST) has recently been under development. The time domain approach has a distinct advantage that the solutions at all frequencies are obtained in a single computation. In this paper, the formulation of the integral equation, as well as its stabilization by the Burton-Miller type reformulation, is extended to cases of a constant mean flow in an arbitrary direction. In addition, a "Source Surface" is also introduced in the formulation that can be employed to encapsulate regions of noise sources and to facilitate coupling with CFD simulations. This is particularly useful for applications where the noise sources are not easily described by analytical source terms. Numerical examples are presented to assess the accuracy of the formulation, including a computation of noise shielding by a thin barrier motivated by recent Historical Baseline F31A31 open rotor noise shielding experiments. Furthermore, spatial resolution requirements of the time domain boundary element method are also assessed using point per wavelength metrics. It is found that, using only constant basis functions and high-order quadrature for surface integration, relative errors of less than 2% may be obtained when the surface spatial resolution is 5 points-per-wavelength (PPW) or 25 points-per-wavelength squared (PPW2).

  19. Range assessment in particle therapy based on prompt γ-ray timing measurements

    International Nuclear Information System (INIS)

    Proton and ion beams open up new vistas for the curative treatment of tumors, but adequate technologies for monitoring the compliance of dose delivery with treatment plans in real time are still missing. Range assessment, meaning the monitoring of therapy-particle ranges in tissue during dose delivery (treatment), is a continuous challenge considered a key for tapping the full potential of particle therapies. In this context the paper introduces an unconventional concept of range assessment by prompt-gamma timing (PGT), which is based on an elementary physical effect not considered so far: therapy particles penetrating tissue move very fast, but still need a finite transit time—about 1–2 ns in case of protons with a 5–20 cm range—from entering the patient’s body until stopping in the target volume. The transit time increases with the particle range. This causes measurable effects in PGT spectra, usable for range verification. The concept was verified by proton irradiation experiments at the AGOR cyclotron, KVI-CART, University of Groningen. Based on the presented kinematical relations, we describe model calculations that very precisely reproduce the experimental results. As the clinical treatment conditions entail measurement constraints (e.g. limited treatment time), we propose a setup, based on clinical irradiation conditions, capable of determining proton range deviations within a few seconds of irradiation, thus allowing for a fast safety survey. Range variations of 2 mm are expected to be clearly detectable. (paper)

  20. Assessment of Smolt Condition for Travel Time Analysis Project, 1987-1997 Project Review.

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Robin M.; Hans, Karen M.; Beeman, John W. [US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA

    1997-12-01

    The assessment of Smolt Condition for Travel Time Analysis Project (Bonneville Power Administration Project 87-401) monitored attributes of salmonid smolt physiology in the Columbia and Snake River basins from 1987 to 1997, under the Northwest Power Planning Council Fish and Wildlife Program, in cooperation with the Smolt Monitoring Program of the Fish Passage Center. The primary goal of the project was to investigate the physiological development of juvenile salmonids related to migration rates. The assumption was made that the level of smolt development, interacting with environmental factos such as flow, would be reflected in travel times. The Fish Passage Center applied the physiological measurements of smolt condition to Water Budget management, to regulate flows so as to decrease travel time and increase survival.

  1. R/S method for evaluation of pollutant time series in environmental quality assessment

    Directory of Open Access Journals (Sweden)

    Bu Quanmin

    2008-12-01

    Full Text Available The significance of the fluctuation and randomness of the time series of each pollutant in environmental quality assessment is described for the first time in this paper. A comparative study was made of three different computing methods: the same starting point method, the striding averaging method, and the stagger phase averaging method. All of them can be used to calculate the Hurst index, which quantifies fluctuation and randomness. This study used real water quality data from Shazhu monitoring station on Taihu Lake in Wuxi, Jiangsu Province. The results show that, of the three methods, the stagger phase averaging method is best for calculating the Hurst index of a pollutant time series from the perspective of statistical regularity.

  2. Data Base for a National Mineral-Resource Assessment of Undiscovered Deposits of Gold, Silver, Copper, Lead, and Zinc in the Conterminous United States

    Science.gov (United States)

    Ludington, S.D.; Cox, D.P.; McCammon, R.B.

    1996-01-01

    For this assessment, the conterminous United States was divided into 12 regions Adirondack Mountains, Central and Southern Rocky Mountains, Colorado Plateau, East Central, Great Basin, Great Plains, Lake Superior, Northern Appalachians, Northern Rocky Mountains, Pacific Coast, Southern Appalachians, and Southern Basin and Range. The assessment, which was conducted by regional assessment teams of scientists from the USGS, was based on the concepts of permissive tracts and deposit models. Permissive tracts are discrete areas of the United States for which estimates of numbers of undiscovered deposits of a particular deposit type were made. A permissive tract is defined by its geographic boundaries such that the probability of deposits of the type delineated occurring outside the boundary is neglible. Deposit models, which are based on a compilation of worldwide literature and on observation, are sets of data in a convenient form that describe a group of deposits which have similar characteristics and that contain information on the common geologic attributes of the deposits and the environments in which they are found. Within each region, the assessment teams delineated permissive tracts for those deposit models that were judged to be appropriate and, when the amount of information warranted, estimated the number of undiscovered deposits. A total of 46 deposit models were used to assess 236 separate permissive tracts. Estimates of undiscovered deposits were limited to a depth of 1 km beneath the surface of the Earth. The estimates of the number of undiscovered deposits of gold, silver, copper, lead, and zinc were expressed in the form of a probability distribution. Commonly, the number of undiscovered deposits was estimated at the 90th, 50th, and 10th percentiles. A Monte Carlo simulation computer program was used to combine the probability distribution of the number of undiscovered deposits with the grade and tonnage data sets associated with each deposit model to

  3. Strategy for the lowering and the assessment of exposure to nanoparticles at workspace - Case of study concerning the potential emission of nanoparticles of Lead in an epitaxy laboratory

    Science.gov (United States)

    Artous, Sébastien; Zimmermann, Eric; Douissard, Paul-Antoine; Locatelli, Dominique; Motellier, Sylvie; Derrough, Samir

    2015-05-01

    The implementation in many products of manufactured nanoparticles is growing fast and raises new questions. For this purpose, the CEA - NanoSafety Platform is developing various research topics for health and safety, environment and nanoparticles exposure in professional activities. The containment optimisation for the exposition lowering, then the exposure assessment to nanoparticles is a strategy for safety improvement at workplace and workspace. The lowering step consists in an optimisation of dynamic and static containment at workplace and/or workspace. Generally, the exposure risk due to the presence of nanoparticles substances does not allow modifying the parameters of containment at workplace and/or workspace. Therefore, gaseous or nanoparticulate tracers are used to evaluate performances of containment. Using a tracer allows to modify safely the parameters of the dynamic containment (ventilation, flow, speed) and to study several configurations of static containment. Moreover, a tracer allows simulating accidental or incidental situation. As a result, a safety procedure can be written more easily in order to manage this type of situation. The step of measurement and characterization of aerosols can therefore be used to assess the exposition at workplace and workspace. The case of study, aim of this paper, concerns the potential emission of Lead nanoparticles at the exhaust of a furnace in an epitaxy laboratory. The use of Helium tracer to evaluate the performance of containment is firstly studied. Secondly, the exposure assessment is characterised in accordance with the French guide “recommendations for characterizing potential emissions and exposure to aerosols released from nanomaterials in workplace operations”. Thirdly the aerosols are sampled, on several places, using collection membranes to try to detect traces of Lead in air.

  4. Highly time-variable exposure to chemicals--toward an assessment strategy.

    Science.gov (United States)

    Ashauer, Roman; Brown, Colin D

    2013-07-01

    Organisms in the environment experience fluctuating, pulsed, or intermittent exposure to pollutants. Accounting for effects of such exposures is an important challenge for environmental risk assessment, particularly given the simplified design of standard ecotoxicity tests. Dynamic simulation using toxicokinetic-toxicodynamic (TK-TD) models describes the processes that link exposure with effects in an organism and provides a basis for extrapolation to a range of exposure scenarios. In so doing, TK-TD modeling makes the risk assessment more robust and aids use and interpretation of experimental data. Toxicokinetic-toxicodynamic models are well-developed for predicting survival of individual organisms and are increasingly applied to sublethal endpoints. In the latter case particularly, linkage to individual-based models (IBMs) allows extrapolation to population level as well as accounting for differences in effects of toxicant exposure at different stages in the life cycle. Extrapolation between species remains an important constraint because there is currently no systematic understanding of species traits that cause differences in the relevant processes. Toxicokinetic-toxicodynamic models allow interrogation of exposure profiles to determine intrinsic toxicity potential rather than using absolute maximum concentrations or time-weighted averages as surrogates. A decision scheme is proposed to guide selection of risk assessment approaches using dose extrapolation based on Haber's Law, TK-TD models, and/or IBMs depending on the nature of toxic effect and timing in relation to life history. PMID:23564608

  5. Time-dependent probabilistic seismic hazard assessment and its application to Hualien City, Taiwan

    Directory of Open Access Journals (Sweden)

    C.-H. Chan

    2013-05-01

    Full Text Available Here, we propose a time-dependent probabilistic seismic hazard assessment and apply it to Hualien City, Taiwan. A declustering catalog from 1940 to 2005 was used to build up a long-term seismicity rate model using a smoothing Kernel function. We also evaluated short-term seismicity rate perturbations according to the rate-and-state friction model, and the Coulomb stress changes imparted by earthquakes from 2006 to 2010. We assessed both long-term and short-term probabilistic seismic hazards by considering ground motion prediction equations for crustal and subduction earthquakes. The long-term seismic hazard in Hualien City gave a PGA (peak ground acceleration of 0.46 g for the 2.1‰ annual exceedance probability. The result is similar to the levels determined in previous studies. Seismic hazards were significantly elevated following the 2007 ML =5.8 earthquake that occurred approximately 10 km from Hualien City. This work presents an assessment of a suitable mechanism for time-dependent probabilistic seismic hazard determinations using an updated earthquake catalog. Using minor model assumptions, our approach provides a suitable basis for rapid re-evaluations and will benefit decision-makers and public officials regarding seismic hazard mitigation.

  6. Tongue-Tie Assessment and Division: A Time-Critical Intervention to Optimise Breastfeeding

    Directory of Open Access Journals (Sweden)

    Jack Donati-Bourne

    2015-01-01

    Full Text Available Objectives: Recent reports have highlighted the benefits of surgical division of tongue-tie (frenulotomy in infants with breastfeeding difficulties. There is no clear consensus defining the appropriate age for this procedure to be undertaken in selected infants. We aimed to evaluate the impact of delays in time between referral and frenulotomy in relation to maternal abandonment of breastfeeding.Materials and Methods: This was a prospective cohort study done in out-patient Neonatal Surgery Department, Birmingham Heartlands Hospital, Birmingham, UK, between April 2013 and July 2013. All infants, referred to our tongue-tie clinic between April and July 2013, were studied prospectively. Referral time lags were calculated using computer records; details regarding breastfeeding were collected by an independent interviewer completing a questionnaire.Results: Seventy patients were included. The median infant age at clinic was 28.5 days [range 1-126]. Fifty eight [82%] of mothers had breastfeeding difficulty and their infants were confirmed to have a prominent tongue-tie. By the time of their clinic attendance, breastfeeding had either not been established or abandoned in 21%. Despite difficulty, 61% of mothers persisted breastfeeding and all these mothers consented for frenulotomy. At time of clinic, median age of infants whose mothers had abandoned breastfeeding was 37 days [range 1-80] compared to 27 days [range 1-126] in infants whose mothers had persisted.Conclusions: We demonstrated a time-critical dimension for frenulotomy: delay beyond 4-weeks from referral to assessment of neonatal tongue-tie is more likely to be associated with abandonment of breastfeeding. Timely assessment and division of tongue-tie in selected infants can therefore play an important role in a birthing unit’s breastfeeding strategy.

  7. Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chih-Yao [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Hon, Min-Hsiung [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Wang, Moo-Chin, E-mail: mcwang@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 80728, Taiwan (China); Chen, Ying-Ru; Chang, Kuo-Ming; Li, Wang-Long [Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China)

    2014-01-05

    Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag{sub 3}Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn{sub 3}. No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging.

  8. Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

    International Nuclear Information System (INIS)

    Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag3Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn3. No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging

  9. Therapeutic Assessment for Preadolescent Boys with Oppositional Defiant Disorder: A Replicated Single-Case Time-Series Design

    Science.gov (United States)

    Smith, Justin D.; Handler, Leonard; Nash, Michael R.

    2010-01-01

    The Therapeutic Assessment (TA) model is a relatively new treatment approach that fuses assessment and psychotherapy. The study examines the efficacy of this model with preadolescent boys with oppositional defiant disorder and their families. A replicated single-case time-series design with daily measures is used to assess the effects of TA and to…

  10. Assessing qualitative usability in life-threatening, time-critical and unstable situations

    Directory of Open Access Journals (Sweden)

    Nestler, Simon

    2011-01-01

    Full Text Available We developed a heuristic for assessing the usability of mobile user-interfaces in life-threating, time-critical and unstable situations in a qualitative way. The major advantages of our approach as opposed to standardized quantitative questionnaires is the independence from a baseline, the possibility to make absolute statements and the potential for adaptations. When creating a qualitative semi structured interview we adhere to the common modus operandi of the qualitative social research. On the basis of 17 common quantitative questionnaires on usability we identified the five major categories Utility, Intuitiveness, Memorability, Learnability and Personal Effect. We selected all questions from the questionnaires which are useful for assessing the usability of user-interfaces in emergencies. Furthermore, we rephrased the closed-ended questions to open-ended ones. The quantification of research results is possible by weighting the qualitative results in dependence to the research question.

  11. Glutamate-induced obesity leads to decreased sperm reserves and acceleration of transit time in the epididymis of adult male rats

    Directory of Open Access Journals (Sweden)

    Fernandes Glaura SA

    2012-12-01

    Full Text Available Abstract Background Given the established fact that obesity interferes with male reproductive functions, the present study aimed to evaluate sperm production in the testis and storage in the epididymis in a glutamate-induced model of obesity. Methods Male rats were treated neonatally with monosodium glutamate (MSG at doses of 4 mg/kg subcutaneously, or with saline solution (control group, on postnatal days 2, 4, 6, 8 and 10. On day 120, obesity was confirmed by the Lee index in all MSG-treated rats. After this, all animals from the two experimental groups were anesthetized and killed to evaluate body and reproductive organ weights, sperm parameters, plasma hormone levels (FSH, LH and testosterone, testicular and epididymal histo-morphometry and histopathology. Results Significant reductions in absolute and relative weights of testis, epididymis, prostate and seminal vesicle were noted in MSG-treated animals. In these same animals plasma testosterone and follicle-stimulating hormone (FSH concentrations were decreased, as well as sperm counts in the testis and epididymis and seminiferous epithelium height and tubular diameter. The sperm transit time was accelerated in obese rats. However, the number of Sertoli cells per seminiferous tubule and stereological findings on the epididymis were not markedly changed by obesity. Conclusions Neonatal MSG-administered model of obesity lowers sperm production and leads to a reduction in sperm storage in the epididymis of adult male rats. The acceleration of sperm transit time can have implications for the sperm quality of these rats.

  12. Radionuclide esophageal transit time for the assessment of pneumatic dilation in patients with achalasia

    Directory of Open Access Journals (Sweden)

    El-Desouki Mahmoud

    1999-01-01

    Full Text Available Objective: The aim of this study was to assess the value of radionuclide esophageal transit time (RET in prediction of the results of pneumatic dilation in patients with achalasia. Patients and methods: Thirty patients (13 males with a mean age of 37 ± 15.6 years (range 17-73 years were included in the study. All patients were diagnosed to have idiopathic achalasia of the cardia and selected for pneumatic dilation. Each patient had three RET, two the same day of dilation (pre-and postdilation and a third follow up one within three months of dilation (4 patients failed to come for follow up and were excluded. Results: Several parameters were derived from RET studies, T/50: time required for 50% of activity in the esophagus to be cleared, T/10 : time required for 90% of activity in the esophagus to be cleared and percentage clearance at 10 min. These parameters were compared to response of dysphagia to dilation. It was evident that the higher the esophageal clearance postdilation, the better the outcome. When immediate post dilation clearance was 85% or more the success rate was 83.3% whereas when it was 20-50% the success rate was only 21.4%. No relation was found between T/50, T/10 and dysphagia response. Conclusion: RET appears to be a useful quantitative procedure in the assessment of pneumatic dilation outcome in achalasia patients.

  13. Performance assessment of an algorithm for the alignment of fMRI time series.

    Science.gov (United States)

    Ciulla, Carlo; Deek, Fadi P

    2002-01-01

    This paper reports on performance assessment of an algorithm developed to align functional Magnetic Resonance Image (fMRI) time series. The algorithm is based on the assumption that the human brain is subject to rigid-body motion and has been devised by pipelining fiducial markers and tensor based registration methodologies. Feature extraction is performed on each fMRI volume to determine tensors of inertia and gradient image of the brain. A head coordinate system is determined on the basis of three fiducial markers found automatically at the head boundary by means of the tensors and is used to compute a point-based rigid matching transformation. Intensity correction is performed with sub-voxel accuracy by trilinear interpolation. Performance of the algorithm was preliminarily assessed by fMR brain images in which controlled motion has been simulated. Further experimentation has been conducted with real fMRI time series. Rigid-body transformations were retrieved automatically and the value of motion parameters compared to those obtained with the Statistical Parametric Mapping (SPM99) and the Automatic Image Registration (AIR 3.08). Results indicate that the algorithm offers sub-voxel accuracy in performing both misalignment and intensity correction of fMRI time series. PMID:12137364

  14. Time Domain Measures of Heart Rate Variability to Assess Autonomic Dysfunction In Irritable Bowel Syndrome

    Directory of Open Access Journals (Sweden)

    Mohammad Nayem, Noorzahan Begum, Sultana Ferdousi

    2012-12-01

    Full Text Available AbstractBackground: Autonomic nerve function impairment is related to development of Irritable Bowel Syndrome (IBS. Time domain measures of Heart rate variability (HRV is a useful tool to measure autonomic nerve function activity.Objective: To assess autonomic nerve function activity by time domain measures of heart rate variability in patients with Irritable Bowel Syndrome.Methods: This cross sectional study was conducted in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU, Dhaka in 2011. Ninety patients aged 20-50 years of both sex with Irritable bowel syndrome were included in the study group. They were collected from the OPD of Gastroenterology in BSMMU. Age and sex matched 30 apparently healthy subjects served as control. For assessing HRV by time domain method, Mean heart rate Mean R-R interval, Max/Min R-R interval, SDNN, RMSSD, PNN50%, NN50% were recorded by a digital Polyrite. ANOVA, independent sample t-test and Pearson’s correlation coefficient tests were performed as applicable.Results: Mean heart rate were significantly higher and Mean R-R interval, Max/Min R-R interval, SDNN, RMSSD, PNN50%, NN50% were significantly lower in IBS groups compared to those of control. Correlation analysis showed negative correlations of SDNN, RMSSD, PNN50%, NN50% with duration of disease.Conclusion: This study concludes that parasympathetic activity was reduced in patients of IBS. In addition, decreased vagal modulation is inversely related to the duration IBS.

  15. Assessing time-integrated dissolved concentrations and predicting toxicity of metals during diel cycling in streams

    Science.gov (United States)

    Balistrieri, Laurie S.; Nimick, David A.; Mebane, Christopher A.

    2012-01-01

    Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 h) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical mining activities in southwestern Montana. A combination of sampling and modeling tools was used to assess the toxicity of metals in these systems. Diffusive Gradients in Thin Films (DGT) samplers were deployed at multiple time intervals during diel sampling to confirm that DGT integrates time-varying concentrations of dissolved metals. Site specific water compositions, including time-integrated dissolved metal concentrations determined from DGT, a competitive, multiple-toxicant biotic ligand model, and the Windemere Humic Aqueous Model Version 6.0 (WHAM VI) were used to determine the equilibrium speciation of dissolved metals and biotic ligands. The model results were combined with previously collected toxicity data on cutthroat trout to derive a relationship that predicts the relative survivability of these fish at a given site. This integrative approach may prove useful for assessing water quality and toxicity of metals to aquatic organisms in dynamic systems and evaluating whether potential changes in environmental health of aquatic systems are due to anthropogenic activities or natural variability.

  16. Empirical Assessment on Factors Affecting Travel Time of Bus Rapid Transit

    Directory of Open Access Journals (Sweden)

    Fergyanto E Gunawan

    2015-02-01

    Full Text Available Since the beginning of the century, many cities around the world adopt the bus rapid transit (BRT system to fulfill their need of mass transportation system. The system features with platform-level boarding, bus lanes in the central verge of the road, off-vehicle fare collection, and physically protected busway. So far, these criteria are considered to be the most important aspects with respect to the BRT performance. In this research, we intend to study to what extent the BRT performance may be affected by the interference of the mixed traffic during the BRT operation. We adopt an empirical approach by observing the phenomenon unfolding in the eleven TransJakarta BRT corridors. The TransJakarta BRT operates in the city of Jakarta, the capital of the Republic of Indonesia. We record the travel time data from station to station for the case where the TransJakarta bus can travel smoothly and the case where the traveling bus is interfered with the mixed traffic. For the cases, we evaluate the travel time variation. As the results, we found that the Corridor 1 of TransJakarta BRT has the best performance in term of the travel time variation. For the two directions, the corridor has the mean travel time of 34 min, the standard deviation of 3 min, and the travel time variation of 8%. On this corridor, the mixed-traffic interference is relatively negligible. On the Corridor 7, the two-direction travel times have the mean of 45 min, the standard deviation of 8 min, and the travel time variation of 16%. On the Corridor 9, the twodirection travel times have the mean of 1 hr and 25 min, the standard deviation of 11 min, and the travel time variation of 14%. On the last two corridors, the busways are heavily interfered by the mixed traffic; thus, the end-to-end travel times are significantly uncertain although only very few road segments are interfered. The research leads us to a conclusion that the interference, although only occurs on a road segment, may

  17. Health impact assessment and monetary valuation of IQ loss in pre-school children due to lead exposure through locally produced food.

    Science.gov (United States)

    Bierkens, J; Buekers, J; Van Holderbeke, M; Torfs, R

    2012-01-01

    A case study has been performed which involved the full chain assessment from policy drivers to health effect quantification of lead exposure through locally produced food on loss of IQ in pre-school children at the population level across the EU-27, including monetary valuation of the estimated health impact. Main policy scenarios cover the period from 2000 to 2020 and include the most important Community policy developments expected to affect the environmental release of lead (Pb) and corresponding human exposure patterns. Three distinct scenarios were explored: the emission situation based on 2000 data, a business-as-usual scenario (BAU) up to 2010 and 2020 and a scenario incorporating the most likely technological change expected (Most Feasible Technical Reductions, MFTR) in response to current and future legislation. Consecutive model calculations (MSCE-HM, WATSON, XtraFOOD, IEUBK) were performed by different partners on the project as part of the full chain approach to derive estimates of blood lead (B-Pb) levels in children as a consequence of the consumption of local produce. The estimated B-Pb levels were translated into an average loss of IQ points/child using an empirical relationship based on a meta-analysis performed by Schwartz (1994). The calculated losses in IQ points were subsequently further translated into the average cost/child using a cost estimate of €10.000 per loss of IQ point based on data from a literature review. The estimated average reduction of cost/child (%) for all countries considered in 2010 under BAU and MFTR are 12.16 and 18.08% as compared to base line conditions, respectively. In 2020 the percentages amount to 20.19 and 23.39%. The case study provides an example of the full-chain impact pathway approach taking into account all foreseeable pathways both for assessing the environmental fate and the associated human exposure and the mode of toxic action to arrive at quantitative estimates of health impacts at the individual and

  18. Compton camera and prompt gamma ray timing: two methods for in vivo range assessment in proton therapy

    Directory of Open Access Journals (Sweden)

    Fernando eHueso-González

    2016-04-01

    Full Text Available Proton beams are promising means for treating tumours. Such charged particles stop at a defined depth, where the ionization density is maximum. As the dose deposit beyond this distal edge is very low, proton therapy minimises the damage to normal tissue compared to photon therapy. Nevertheless, inherent range uncertainties cast doubts on the irradiation of tumours close to organs at risk and lead to the application of conservative safety margins. This constrains significantly the potential benefits of protons over photons. In this context, several research groups are developing experimental tools for range verification based on the detection of prompt gammas, a nuclear by-product of the proton irradiation. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf, detector components have been characterised in realistic radiation environments as a step towards a clinical Compton camera. Corresponding experimental methods and results obtained during the ENTERVISION training network are reviewed. On the other hand, a novel method based on timing spectroscopy has been proposed as an alternative to collimated imaging systems. The first tests of the timing method at a clinical proton accelerator are summarised, its applicability in a clinical environment for challenging the current safety margins is assessed, and the factors limiting its precision are discussed.

  19. Compton Camera and Prompt Gamma Ray Timing: Two Methods for In Vivo Range Assessment in Proton Therapy

    Science.gov (United States)

    Hueso-González, Fernando; Fiedler, Fine; Golnik, Christian; Kormoll, Thomas; Pausch, Guntram; Petzoldt, Johannes; Römer, Katja E.; Enghardt, Wolfgang

    2016-01-01

    Proton beams are promising means for treating tumors. Such charged particles stop at a defined depth, where the ionization density is maximum. As the dose deposit beyond this distal edge is very low, proton therapy minimizes the damage to normal tissue compared to photon therapy. Nevertheless, inherent range uncertainties cast doubts on the irradiation of tumors close to organs at risk and lead to the application of conservative safety margins. This constrains significantly the potential benefits of protons over photons. In this context, several research groups are developing experimental tools for range verification based on the detection of prompt gammas, a nuclear by-product of the proton irradiation. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf, detector components have been characterized in realistic radiation environments as a step toward a clinical Compton camera. On the one hand, corresponding experimental methods and results obtained during the ENTERVISION training network are reviewed. On the other hand, a novel method based on timing spectroscopy has been proposed as an alternative to collimated imaging systems. The first tests of the timing method at a clinical proton accelerator are summarized, its applicability in a clinical environment for challenging the current safety margins is assessed, and the factors limiting its precision are discussed. PMID:27148473

  20. Redução do lead time e entregas no prazo em pequenas e médias empresas que fabricam sob encomenda: a abordagem Worload Control (WLC para o Planejamento e Controle da Produção (PCP Lead time reduction and improved tardiness performance in small and medium sized Make-to-Order Companies: the Workload Control (WLC approach, a solution for Production Planning and Control (PPC

    Directory of Open Access Journals (Sweden)

    Matthias Thurer

    2012-01-01

    designed for small sized Make-to-Order companies. According to the literature, such approach has the potential to reduce lead time, work in process, and to provide a better tardiness performance in MTO companies. Firstly, the paper presents the WLC approach reviewing and discussing the main WLC aspects addressed in the literature. The objective is to introduce the concept and present the recent developments to fellow researchers and practitioners. The performance of WLC is then assessed by simulation. The results underline the potential of WLC to bring major improvements in terms of lead time and tardiness performance supporting small and medium sized MTO companies. Therefore, this study aims at contributing to PPC academic and practical areas by introducing WLC approach concepts to Brazilian researchers and managers showing its benefits and potential to help national companies in their efforts towards lead time reduction and best tardiness performance according to modern manufacturing paradigms such as Lean Manufacturing and Quick Response Manufacturing.

  1. Development of Real-Time Bayesian Data Assimilation System for Off-Site Consequence Assessment

    Czech Academy of Sciences Publication Activity Database

    Hofman, Radek; Šmídl, Václav; Pecha, Petr

    Nara: Atomic Energy Society of Japan, 2012, s. 37-37. [12th International Conference on Radiation Shielding & 17th Topical Meeting of the Radiation Protection and Shielding Division of the American Nuclear Society. Nara (JP), 2.-7. 9. 2012] R&D Projects: GA MV(CZ) VG20102013018 Institutional support: RVO:67985556 Keywords : data assimilation * sequential Monte Carlo * decision support system Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality http://library.utia.cas.cz/separaty/2012/AS/hofman-development of real-time bayesian data assimilation system for off-site consequence assessment.pdf

  2. Imaging techniques used for the real-time assessment of angiogenesis in digestive cancers

    DEFF Research Database (Denmark)

    Saftoiu, Adrian; Vilmann, Peter; Săftoiu, Adrian

    2011-01-01

    evaluation, but also on sensitive monitoring of microvascular changes during treatment. State-of-the-art imaging techniques have the potential to visualize and characterize angiogenesis, although the technology and methodologies employed are recent and need further validation. The aim of this series of...... reviews was to analyze and enhance current knowledge and future perspectives about the real-time assessment of angiogenesis in digestive cancers, used for the longitudinal monitoring of the effects of chemo-radiotherapy (including anti-angiogenic therapies), as well as for the precise targeting of drugs...

  3. Gastric Emptying Assessment in Frequency and Time Domain Using Bio-impedance: Preliminary Results

    Science.gov (United States)

    Huerta-Franco, R.; Vargas-Luna, M.; Hernández, E.; Córdova, T.; Sosa, M.; Gutiérrez, G.; Reyes, P.; Mendiola, C.

    2006-09-01

    The impedance assessment to measure gastric emptying and in general gastric activity has been reported since 1985. The physiological interpretation of these measurements, is still under research. This technique usually uses a single frequency, and the conductivity parameter. The frequency domain and the Fourier analysis of the time domain behavior of the gastric impedance in different gastric conditions (fasting state, and after food administration) has not been explored in detail. This work presents some insights of the potentiality of these alternative methodologies to measure gastric activity.

  4. Band-phase-randomized Surrogates to assess nonlinearity in non-stationary time series

    CERN Document Server

    Guarin, Diego; Orozco, Alvaro

    2011-01-01

    Testing for nonlinearity is one of the most important preprocessing steps in nonlinear time series analysis. Typically, this is done by means of the linear surrogate data methods. But it is a known fact that the validity of the results heavily depends on the stationarity of the time series. Since most physiological signals are non-stationary, it is easy to falsely detect nonlinearity using the linear surrogate data methods. In this document, we propose a methodology to extend the procedure for generating constrained surrogate time series in order to assess nonlinearity in non-stationary data. The method is based on the band-phase-randomized surrogates, which consists (contrary to the linear surrogate data methods) in randomizing only a portion of the Fourier phases in the high frequency band. Analysis of simulated time series showed that in comparison to the linear surrogate data method, our method is able to discriminate between linear stationarity, linear non-stationary and nonlinear time series. When apply...

  5. Technology assessment of PACS: measurement and analysis of radiologists' reporting times when reporting from film

    Science.gov (United States)

    Bryan, Stirling; Weatherburn, Gwyneth C.; Keen, Justin; Muris, Nicole; Buxton, Martin J.

    1994-05-01

    This paper describes a research project which explored the reasons for variation in reporting time by senior radiologists. The objective was to identify factors which are important to control for in an assessment of the impact of the introduction of a PACS on reporting times. An observational study of reporting by senior radiologists at Hammersmith Hospital was initially undertaken for a period of 25 days. At all times during the working day on the days chosen for the study, an independent health service researcher observed the radiologist reporting on both urgent and non-urgent images. Data were collected on a variety of factors including the time taken to produce the report, the number and nature of the images viewed and the disturbances that occurred. Regression analysis techniques were used to analyze the data in order to identify the factors which explain variation in reporting times. The paper reports the research methods and results from the baseline data on working with conventional hard copy film at Hammersmith Hospital.

  6. Time location analysis for exposure assessment studies of indoor workers based on active RFID technology.

    Science.gov (United States)

    Huang, Fu-Chuan; Shih, Tung-Sheng; Lee, Jiunn-Fwu; Chao, Huan-Ping; Wang, Peng-Yau

    2010-02-01

    In this article, we describe the development of a radio frequency identification exposure monitoring system (RFEMS) suitable for tracking and identifying workers' locations in indoor workplaces. Five workers in southern Taiwan wore the RFEMS integrated into their equipment vests. Location and exposure data were transferred to data analysis software for visualization and tabular analysis in real-time. Data were grouped into seven task activity location categories to determine the time spent and percentage reception in each location. The RFEMS could also synchronously indicate the surrounding conditions using various sensors. Additional experiments were focused on locating of boundaries and determining the instrument stability, power sustainability, and reception efficiency in typical environments. The RFEMS instruments provided adequate range for locating (typically ca. 6-45 m in each zone), allowing us to locate subjects within distinct microenvironments and to distinguish between the activities of a variety of workers, the average time activity pattern (TAP) recording deviation for both human observations and RFEMS was ca. 0.21-1.57%. Power consumption experiments revealed that the system could be sustained for more than 124 h. A pilot field test indicated that the RFEMS offers a new level of accuracy for direct quantification of time activity patterns in exposure assessments of indoor workers over long periods of time. PMID:20145895

  7. Time-course microarrays reveal early activation of the immune transcriptome and adipokine dysregulation leads to fibrosis in visceral adipose depots during diet-induced obesity

    Directory of Open Access Journals (Sweden)

    Kwon Eun-Young

    2012-09-01

    Full Text Available Abstract Background Visceral white adipose tissue (WAT hypertrophy, adipokine production, inflammation and fibrosis are strongly associated with obesity, but the time-course of these changes in-vivo are not fully understood. Therefore, the aim of this study was to establish the time-course of changes in adipocyte morphology, adipokines and the global transcriptional landscape in visceral WAT during the development of diet-induced obesity. Results C57BL/6 J mice were fed a high-fat diet (HFD or normal diet (ND and sacrificed at 8 time-points over 24 weeks. Excessive fat accumulation was evident in visceral WAT depots (Epidydimal, Perirenal, Retroperitoneum, Mesentery after 2–4 weeks. Fibrillar collagen accumulation was evident in epidydimal adipocytes at 24 weeks. Plasma adipokines, leptin, resistin and adipsin, increased early and time-dependently, while adiponectin decreased late after 20 weeks. Only plasma leptin and adiponectin levels were associated with their respective mRNA levels in visceral WAT. Time-course microarrays revealed early and sustained activation of the immune transcriptome in epididymal and mesenteric depots. Up-regulated inflammatory genes included pro-inflammatory cytokines, chemokines (Tnf, Il1rn, Saa3, Emr1, Adam8, Itgam, Ccl2, 3, 4, 6, 7 and 9 and their upstream signalling pathway genes (multiple Toll-like receptors, Irf5 and Cd14. Early changes also occurred in fibrosis, extracellular matrix, collagen and cathepsin related-genes, but histological fibrosis was only visible in the later stages. Conclusions In diet-induced obesity, early activation of TLR-mediated inflammatory signalling cascades by CD antigen genes, leads to increased expression of pro-inflammatory cytokines and chemokines, resulting in chronic low-grade inflammation. Early changes in collagen genes may trigger the accumulation of ECM components, promoting fibrosis in the later stages of diet-induced obesity. New therapeutic approaches

  8. Evaluation of the dynamic impacts of customer centered lead time reduction improvements on customer-oriented and financial performance: a hybrid approach of system dynamics and queuing network analysis

    OpenAIRE

    Alp, Arda; Reiner, Gerald

    2014-01-01

    Motivated by the strategic importance of reduced lead times in today’s competitive business environment, this doctoral dissertation analyzes the dynamic impacts of lead time reduction (LTR) improvements on customer satisfaction and related financial performance metrics. The core thesis is centered on development of an integrated dynamic performance measurement framework which covers operational, customer-oriented and financial performance dependencies over time. The framework is demonstrated ...

  9. A generalised Dynamic Overflow Risk Assessment (DORA) for Real Time Control of urban drainage systems

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Grum, Morten

    2014-01-01

    An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored in the...... drainage network, (ii) the expected runoff volume (calculated by radar-based nowcast models) and – most important – (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows for a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible...... periods, using a simple conceptual model, is presented. Compared to a traditional local control approach, DORA contributed to reduce CSO volumes from the most sensitive points while reducing total CSO volumes discharged from the catchment. Additionally, the results show that the inclusion of forecasts and...

  10. Determination of 210Pb in human skeletal remains from Morocco: implications for time since death assessment

    International Nuclear Information System (INIS)

    In forensic contexts, time since death assessment in human skeletal remains is crucial for identification, and both accuracy and reliability are required. In this paper, we present the possibilities and constraints of the use of 210Pb in dating skeletonized human bones in Morocco. The method was tested on recent as well as archaeological bones of known dates of death. A calibration curve was obtained from the available data in the scientific literature. The 210Pb initial activity was introduced as an increasing lineal function with time. The 210Pb dating approach gives promising results only for recent bones. On the contrary, for archaeological bones, the technique has erroneously led to post-mortem intervals in the range of recent bones which constitute a serious limitation of the method. On the other hand, uranium isotopes content in bones is suggested in this work as a possible indicator in placing a studied bone within either a forensic or archaeological context. (author)

  11. Assessment of adhesive setting time in reinforced concrete beams strengthened with carbon fibre reinforced polymer laminates

    International Nuclear Information System (INIS)

    Highlights: ► This study investigated the effect of adhesive setting time on the modal parameters. ► Modal parameters recommend the 18th day as the maturity age of the adhesive. ► Static data recommend 7th day as the maturity age of the adhesive. ► Setting time affects the modal parameters as tool for assessment repaired structures. ► Carrying the modal parameters after 1st day results in 55% loss of the actual improvement. -- Abstract: The strengthened effectiveness and the performance capacity of repaired Reinforced Concrete (RC) structures with Carbon Fibre Reinforced Polymer (CFRP) sheets is dependent on the properties of the adhesive interface layer. Adhesive material requires a specific setting time to achieve the maximum design capacity. Adhesive producer provides technical data which demonstrates the increase with time of the capacity, up to the maximum. The aim of this study is to investigate the effect of the adhesive setting time on the modal parameters as an indication of the effectiveness of CFRP on repaired RC beams. Firstly, datum modal parameters were determined on the undamaged beam and subsequently the parameters were obtained when damaged was induced on the RC beam by application of load until the appearance of the first crack. Finally, the RC beam is repaired with externally bonded CFRP sheets, and modal parameters are once again applied after 0.5, 1, 2, 3, 5, 8, 11, 15 and 18 days. The comparison is made with the data based on half day results in order to monitor the change in the modal parameters corresponding to the adhesive setting time. The modal parameters where used as indicators for the effectiveness of CFRP are affected by the adhesive time as shown in this study. Results are compared with the adhesive technical data provided by the adhesive producer.

  12. Uso de los datos de plumbemia para evaluar y prevenir el envenenamiento infantil por plomo en Latinoamérica Use of blood lead data in epidemiological studies to assess and prevent childhood lead poisoning in Latin America

    Directory of Open Access Journals (Sweden)

    Isabelle Romieu

    2003-01-01

    widespread and serious threat to the health of children in Latin America. Health officials should monitor sources of exposure and health outcomes to design, implement, and evaluate prevention and control activities. To evaluate the magnitude of lead as a public health problem, three key elements must be defined: 1 the potential sources of exposure, 2 the indicators to evaluate health effects and environmental exposure, and 3 the sampling methods for the population at risk. Several strategies can be used to select the study population depending on the study objectives, the time limitations, and the available resources. If the objective is to evaluate the magnitude and sources of the problem, the following sampling methods can be used: 1 population-based random sampling; 2 facility-based random sampling within hospitals, daycare centers, or schools; 3 target sampling of high risk groups; 4 convenience sampling of volunteers; and 5 case reporting (which can lead to the identification of populations at risk and sources of exposures. For all sampling methods, information gathering should include the use of a questionnaire to collect general information on the participants and on potential local sources of exposure, as well as the collection of biological samples. In interpreting data, one should consider the type of sampling used and the non-response rates, as well as factors that might influence blood lead measurements, such as age and seasonal variability. Blood lead measurements should be integrated in an overall strategy to prevent lead toxicity in children.

  13. Automating Flood Hazard Mapping Methods for Near Real-time Storm Surge Inundation and Vulnerability Assessment

    Science.gov (United States)

    Weigel, A. M.; Griffin, R.; Gallagher, D.

    2015-12-01

    Storm surge has enough destructive power to damage buildings and infrastructure, erode beaches, and threaten human life across large geographic areas, hence posing the greatest threat of all the hurricane hazards. The United States Gulf of Mexico has proven vulnerable to hurricanes as it has been hit by some of the most destructive hurricanes on record. With projected rises in sea level and increases in hurricane activity, there is a need to better understand the associated risks for disaster mitigation, preparedness, and response. GIS has become a critical tool in enhancing disaster planning, risk assessment, and emergency response by communicating spatial information through a multi-layer approach. However, there is a need for a near real-time method of identifying areas with a high risk of being impacted by storm surge. Research was conducted alongside Baron, a private industry weather enterprise, to facilitate automated modeling and visualization of storm surge inundation and vulnerability on a near real-time basis. This research successfully automated current flood hazard mapping techniques using a GIS framework written in a Python programming environment, and displayed resulting data through an Application Program Interface (API). Data used for this methodology included high resolution topography, NOAA Probabilistic Surge model outputs parsed from Rich Site Summary (RSS) feeds, and the NOAA Census tract level Social Vulnerability Index (SoVI). The development process required extensive data processing and management to provide high resolution visualizations of potential flooding and population vulnerability in a timely manner. The accuracy of the developed methodology was assessed using Hurricane Isaac as a case study, which through a USGS and NOAA partnership, contained ample data for statistical analysis. This research successfully created a fully automated, near real-time method for mapping high resolution storm surge inundation and vulnerability for the

  14. T2 star relaxation times for assessment of articular cartilage at 3 T: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Mamisch, Tallal Charles [University Bern, Department of Orthopedic Surgery, Inselspital, Bern (Switzerland); University Bern, Magnetic Resonance Spectroscopy and Methodology, Department of Clinical Research, Bern (Switzerland); Hughes, Timothy [Siemens Medical Solutions, Erlangen (Germany); Mosher, Timothy J. [Penn State University College of Medicine, Musculoskeletal Imaging and MRI, Department of Radiology, Hershey, PA (United States); Mueller, Christoph [University of Erlangen, Department of Trauma Surgery, Erlangen (Germany); Trattnig, Siegfried [Medical University of Vienna, MR Center - High Field MR, Department of Radiology, Vienna (Austria); Boesch, Chris [University Bern, Magnetic Resonance Spectroscopy and Methodology, Department of Clinical Research, Bern (Switzerland); Welsch, Goetz Hannes [University of Erlangen, Department of Trauma Surgery, Erlangen (Germany); Medical University of Vienna, MR Center - High Field MR, Department of Radiology, Vienna (Austria)

    2012-03-15

    T2 mapping techniques use the relaxation constant as an indirect marker of cartilage structure, and the relaxation constant has also been shown to be a sensitive parameter for cartilage evaluation. As a possible additional robust biomarker, T2* relaxation time is a potential, clinically feasible parameter for the biochemical evaluation of articular cartilage. The knees of 15 healthy volunteers and 15 patients after microfracture therapy (MFX) were evaluated with a multi-echo spin-echo T2 mapping technique and a multi-echo gradient-echo T2* mapping sequence at 3.0 Tesla MRI. Inline maps, using a log-linear least squares fitting method, were assessed with respect to the zonal dependency of T2 and T2* relaxation for the deep and superficial regions of healthy articular cartilage and cartilage repair tissue. There was a statistically significant correlation between T2 and T2* values. Both parameters demonstrated similar spatial dependency, with longer values measured toward the articular surface for healthy articular cartilage. No spatial variation was observed for cartilage repair tissue after MFX. Within this feasibility study, both T2 and T2* relaxation parameters demonstrated a similar response in the assessment of articular cartilage and cartilage repair tissue. The potential advantages of T2*-mapping of cartilage include faster imaging times and the opportunity for 3D acquisitions, thereby providing greater spatial resolution and complete coverage of the articular surface. (orig.)

  15. Self-motion perception: assessment by real-time computer-generated animations

    Science.gov (United States)

    Parker, D. E.; Phillips, J. O.

    2001-01-01

    We report a new procedure for assessing complex self-motion perception. In three experiments, subjects manipulated a 6 degree-of-freedom magnetic-field tracker which controlled the motion of a virtual avatar so that its motion corresponded to the subjects' perceived self-motion. The real-time animation created by this procedure was stored using a virtual video recorder for subsequent analysis. Combined real and illusory self-motion and vestibulo-ocular reflex eye movements were evoked by cross-coupled angular accelerations produced by roll and pitch head movements during passive yaw rotation in a chair. Contrary to previous reports, illusory self-motion did not correspond to expectations based on semicircular canal stimulation. Illusory pitch head-motion directions were as predicted for only 37% of trials; whereas, slow-phase eye movements were in the predicted direction for 98% of the trials. The real-time computer-generated animations procedure permits use of naive, untrained subjects who lack a vocabulary for reporting motion perception and is applicable to basic self-motion perception studies, evaluation of motion simulators, assessment of balance disorders and so on.

  16. T2 star relaxation times for assessment of articular cartilage at 3 T: a feasibility study

    International Nuclear Information System (INIS)

    T2 mapping techniques use the relaxation constant as an indirect marker of cartilage structure, and the relaxation constant has also been shown to be a sensitive parameter for cartilage evaluation. As a possible additional robust biomarker, T2* relaxation time is a potential, clinically feasible parameter for the biochemical evaluation of articular cartilage. The knees of 15 healthy volunteers and 15 patients after microfracture therapy (MFX) were evaluated with a multi-echo spin-echo T2 mapping technique and a multi-echo gradient-echo T2* mapping sequence at 3.0 Tesla MRI. Inline maps, using a log-linear least squares fitting method, were assessed with respect to the zonal dependency of T2 and T2* relaxation for the deep and superficial regions of healthy articular cartilage and cartilage repair tissue. There was a statistically significant correlation between T2 and T2* values. Both parameters demonstrated similar spatial dependency, with longer values measured toward the articular surface for healthy articular cartilage. No spatial variation was observed for cartilage repair tissue after MFX. Within this feasibility study, both T2 and T2* relaxation parameters demonstrated a similar response in the assessment of articular cartilage and cartilage repair tissue. The potential advantages of T2*-mapping of cartilage include faster imaging times and the opportunity for 3D acquisitions, thereby providing greater spatial resolution and complete coverage of the articular surface. (orig.)

  17. The Use of NASA near Real-time and Archived Satellite Data to Support Disaster Assessment

    Science.gov (United States)

    McGrath, Kevin M.; Molthan, Andrew; Burks, Jason

    2014-01-01

    With support from a NASA's Applied Sciences Program, The Short-term Prediction Research and Transition (SPoRT) Center has explored a variety of techniques for utilizing archived and near real-time NASA satellite data to support disaster assessment activities. MODIS data from the NASA Land Atmosphere Near Real-time Capability for EOS currently provides true color and other imagery for assessment and potential applications including, but not limited to, flooding, fires, and tornadoes. In May 2013, the SPoRT Center developed unique power outage composites using the VIIRS Day/Night Band to represent the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Pre-event imagery provided by the NASA funded Web-Enabled Landsat Data project offer a basis of comparison for monitoring post-disaster recovery efforts. Techniques have also been developed to generate products from higher resolution imagery from the recently available International Space Station SERVIR Environmental Research and Visualization System instrument. Of paramount importance is to deliver these products to end users expeditiously and in formats compatible with Decision Support Systems (DSS). Delivery techniques include a Tile Map Service (TMS) and a Web Mapping Service (WMS). These mechanisms allow easy integration of satellite products into DSS's, including the National Weather Service's Damage Assessment Toolkit for use by personnel conducting damage surveys. This poster will present an overview of the developed techniques and products and compare the strengths and weaknesses of the TMS and WMS.

  18. Assessing cardiac preload by the Initial Systolic Time Interval obtained from impedance cardiography

    Directory of Open Access Journals (Sweden)

    Jan H Meijer

    2010-01-01

    Full Text Available The Initial Systolic Time Interval (ISTI, obtained from the electrocardiogram (ECG and impedance cardiogram (ICG, is considered to be a measure for the time delay between the electrical and mechanical activity of the heart and reflects an early active period of the cardiac cycle. The clinical relevance of this time interval is subject of study. This paper presents preliminary results of a pilot study investigating the use of ISTI in evaluating and predicting the circulatory response to fluid administration in patients after coronary artery bypass graft surgery, by comparing ISTI with cardiac output (CO responsiveness. Also the use of the pulse transit time (PTT, earlier recommended for this purpose, is investigated. The results show an inverse relationship between ISTI and CO at all moments of fluid administration and also an inverse relationship between the changes ΔISTI and ΔCO before and after full fluid administration. No relationships between PTT and CO or ΔPTT and ΔCO were found. It is concluded that ISTI is dependent upon preload, and that ISTI has the potential to be used as a clinical parameter assessing preload.

  19. Time-domain scanning optical mammography: I. Recording and assessment of mammograms of 154 patients

    International Nuclear Information System (INIS)

    Using a triple wavelength (670 nm, 785 nm, 843/884 nm) scanning laser-pulse mammograph we recorded craniocaudal and mediolateral projection optical mammograms of 154 patients, suspected of having breast cancer. From distributions of times of flight of photons recorded at typically 1000-2000 scan positions, optical mammograms were derived displaying (inverse) photon counts in selected time windows, absorption and reduced scattering coefficients or total haemoglobin concentration and blood oxygen saturation. Optical mammograms were analysed by comparing them with x-ray and MR mammograms, including results of histopathology, attributing a subjective visibility score to each tumour assessed. Out of 102 histologically confirmed tumours, 72 tumours were detected retrospectively in both optical projection mammograms, in addition 20 cases in one projection only, whereas 10 tumours were not detectable in any projection. Tumour contrast and contrast-to-noise ratios of mammograms of the same breast, but derived from measured DTOFs by various methods were quantitatively compared. On average, inverse photon counts in selected time windows, including total photon counts, provide highest tumour contrast and contrast-to-noise ratios. Based on the results of the present study we developed a multi-wavelength, multi-projection scanning time-domain optical mammograph with improved spectral and spatial (angular) sampling, that allows us to record entire mammograms simultaneously at various offsets between the transmitting fibre and receiving fibre bundle and provides first results for illustration

  20. Assessing pulsar timing array sensitivity to gravitational wave bursts with memory

    International Nuclear Information System (INIS)

    Highly energetic astrophysical phenomena like supermassive black hole binary (SMBHB) mergers are predicted to emit prodigious amounts of gravitational waves (GWs). An anticipated component of the gravitational waveform known as 'memory' is permanent and nonoscillatory. For SMBHB mergers, the memory is created primarily during the most violent moments of the inspiral immediately preceding the final plunge and ring-down when the strongest gravitational fields are at work and the nonlinearities of general relativity are most pronounced. The essentially time-domain nature of memory makes it forbiddingly difficult to detect with ground based GW detectors, leaving pulsar timing array (PTA) experiments as the most promising means by which it may be detected and studied. In this paper, we discuss how GW bursts with memory (BWMs) influence pulsar timing experiments and develop methods to assess how sensitive modern timing efforts are to such GW events. We discuss how PTA searches for BWMs can be used to constrain the rate of BWMs and how these constraints relate to information regarding the population of SMBHBs.