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Sample records for subgradient method leads

  1. Approximate Dual Averaging Method for Multiagent Saddle-Point Problems with Stochastic Subgradients

    Directory of Open Access Journals (Sweden)

    Deming Yuan

    2014-01-01

    Full Text Available This paper considers the problem of solving the saddle-point problem over a network, which consists of multiple interacting agents. The global objective function of the problem is a combination of local convex-concave functions, each of which is only available to one agent. Our main focus is on the case where the projection steps are calculated approximately and the subgradients are corrupted by some stochastic noises. We propose an approximate version of the standard dual averaging method and show that the standard convergence rate is preserved, provided that the projection errors decrease at some appropriate rate and the noises are zero-mean and have bounded variance.

  2. A primal sub-gradient method for structured classification with the averaged sum loss

    Directory of Open Access Journals (Sweden)

    Mančev Dejan

    2014-12-01

    Full Text Available We present a primal sub-gradient method for structured SVM optimization defined with the averaged sum of hinge losses inside each example. Compared with the mini-batch version of the Pegasos algorithm for the structured case, which deals with a single structure from each of multiple examples, our algorithm considers multiple structures from a single example in one update. This approach should increase the amount of information learned from the example. We show that the proposed version with the averaged sum loss has at least the same guarantees in terms of the prediction loss as the stochastic version. Experiments are conducted on two sequence labeling problems, shallow parsing and part-of-speech tagging, and also include a comparison with other popular sequential structured learning algorithms.

  3. Modified Spectral Projected Subgradient Method: Convergence Analysis and Momentum Parameter Heuristics

    Directory of Open Access Journals (Sweden)

    Milagros Loreto

    2016-09-01

    Full Text Available The Modified Spectral Projected Subgradient (MSPS was proposed to solve Langrangen Dual Problems, and its convergence was shown when the momentum term was zero. The MSPS uses a momentum term in order to speed up its convergence. The momentum term is built on the multiplication of a momentum parameter and the direction of the previous iterate. In this work, we show convergence when the momentum parameter is a non-zero constant. We also propose heuristics to choose the momentum parameter intended to avoid the Zigzagging Phenomenon of Kind I. This phenomenon is present in the MSPS when at an iterate the subgradient forms an obtuse angle with the previous direction. We identify and diminish the Zigzagging Phenomenon of Kind I on Setcovering problems, and compare our numerical results to those of the original MSPS algorithm.

  4. Privacy Preservation in Distributed Subgradient Optimization Algorithms

    OpenAIRE

    Lou, Youcheng; Yu, Lean; Wang, Shouyang

    2015-01-01

    Privacy preservation is becoming an increasingly important issue in data mining and machine learning. In this paper, we consider the privacy preserving features of distributed subgradient optimization algorithms. We first show that a well-known distributed subgradient synchronous optimization algorithm, in which all agents make their optimization updates simultaneously at all times, is not privacy preserving in the sense that the malicious agent can learn other agents' subgradients asymptotic...

  5. A subgradient-based branch-and-bound algorithm for the capacitated facility location problem

    DEFF Research Database (Denmark)

    Görtz, Simon; Klose, Andreas

    This paper presents a simple branch-and-bound method based on Lagrangean relaxation and subgradient optimization for solving large instances of the capacitated facility location problem (CFLP) to optimality. In order to guess a primal solution to the Lagrangean dual, we average solutions to the L......This paper presents a simple branch-and-bound method based on Lagrangean relaxation and subgradient optimization for solving large instances of the capacitated facility location problem (CFLP) to optimality. In order to guess a primal solution to the Lagrangean dual, we average solutions...... to the Lagrangean subproblem. Branching decisions are then based on this estimated (fractional) primal solution. Extensive numerical results reveal that the method is much more faster and robust than other state-of-the-art methods for solving the CFLP exactly....

  6. Distributed Constrained Stochastic Subgradient Algorithms Based on Random Projection and Asynchronous Broadcast over Networks

    Directory of Open Access Journals (Sweden)

    Junlong Zhu

    2017-01-01

    Full Text Available We consider a distributed constrained optimization problem over a time-varying network, where each agent only knows its own cost functions and its constraint set. However, the local constraint set may not be known in advance or consists of huge number of components in some applications. To deal with such cases, we propose a distributed stochastic subgradient algorithm over time-varying networks, where the estimate of each agent projects onto its constraint set by using random projection technique and the implement of information exchange between agents by employing asynchronous broadcast communication protocol. We show that our proposed algorithm is convergent with probability 1 by choosing suitable learning rate. For constant learning rate, we obtain an error bound, which is defined as the expected distance between the estimates of agent and the optimal solution. We also establish an asymptotic upper bound between the global objective function value at the average of the estimates and the optimal value.

  7. A Piecewise Monotone Subgradient Algorithm for Accurate L1 -TV Based Registration of Physical Slices With Discontinuities in Microscopy

    Czech Academy of Sciences Publication Activity Database

    Michálek, Jan; Čapek, Martin

    2013-01-01

    Roč. 32, č. 5 (2013), s. 901-918 ISSN 0278-0062 R&D Projects: GA MŠk(CZ) LH13028; GA ČR(CZ) GAP501/10/0340; GA ČR(CZ) GAP108/11/0794; GA TA ČR(CZ) TA02011193 Institutional support: RVO:67985823 Keywords : convex optimization * image registration * subgradient algorithm * total variation Subject RIV: EA - Cell Biology Impact factor: 3.799, year: 2013

  8. Apparatus and methods for purifying lead

    Science.gov (United States)

    Tunison, Harmon M.

    2016-01-12

    Disclosed is an exemplary method of purifying lead which includes the steps of placing lead and a fluoride salt blend in a container; forming a first fluid of molten lead at a first temperature; forming a second fluid of the molten fluoride salt blend at a second temperature higher than the first temperature; mixing the first fluid and the second fluid together; separating the two fluids; solidifying the molten fluoride salt blend at a temperature above a melting point of the lead; and removing the molten lead from the container. In certain exemplary methods the molten lead is removed from the container by decanting. In still other exemplary methods the molten salt blend is a Lewis base fluoride eutectic salt blend, and in yet other exemplary methods the molten salt blend contains sodium fluoride, lithium fluoride, and potassium fluoride.

  9. The Matrix Element Method at Next-to-Leading Order

    OpenAIRE

    Campbell, John M.; Giele, Walter T.; Williams, Ciaran

    2012-01-01

    This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of...

  10. Discriminating background from anthropogenic lead by isotopic methods

    International Nuclear Information System (INIS)

    Nelson, B.K.; O'Brien, H.E.

    1995-01-01

    The goal of this pilot project was to evaluate the practicality of using natural variations in the isotopic composition of lead to test for the presence of anthropogenic lead in soil, surface water and ground water. Complex chemical reactions in the environment may cause measured lead concentrations to be ambiguous indicators of anthropogenic lead component. The lead isotope tracer technique has the potential to identify both the presence and proportion of anthropogenic lead in the environment. The tested the lead isotope technique at Eielson Air Force Base, Alaska, on sources of suspected fuel contamination. Although the results are specific to this base, the general technique of using lead isotopes to trace the movement of anthropogenic lead is applicable to other CERCLA sites. The study had four objectives: (1) characterize the natural lead isotope composition of bedrock, stream sediment and soils; (2) characterize the isotopic composition of the contaminant lead derived from fuel; (3) evaluate the sensitivity of the isotopic method to distinguishing between anthropogenic and natural lead in soil and water samples and (4) evaluate the analytical feasibility and accuracy of the method at the Isotope Geochemistry Laboratory at the University of Washington

  11. Do new wipe materials outperform traditional lead dust cleaning methods?

    Science.gov (United States)

    Lewis, Roger D; Ong, Kee Hean; Emo, Brett; Kennedy, Jason; Brown, Christopher A; Condoor, Sridhar; Thummalakunta, Laxmi

    2012-01-01

    Government guidelines have traditionally recommended the use of wet mopping, sponging, or vacuuming for removal of lead-contaminated dust from hard surfaces in homes. The emergence of new technologies, such as the electrostatic dry cloth and wet disposable clothes used on mopheads, for removal of dust provides an opportunity to evaluate their ability to remove lead compared with more established methods. The purpose of this study was to determine if relative differences exist between two new and two older methods for removal of lead-contaminated dust (LCD) from three wood surfaces that were characterized by different roughness or texture. Standard leaded dust, coefficient of friction was performed for each wipe material. Analysis of variance was used to evaluate the surface and cleaning methods. There were significant interactions between cleaning method and surface types, p = 0.007. Cleaning method was found be a significant factor in removal of lead, p coefficient of friction, significantly different among the three wipes, is likely to influence the cleaning action. Cleaning method appears to be more important than texture in LCD removal from hard surfaces. There are some small but important factors in cleaning LCD from hard surfaces, including the limits of a Swiffer mop to conform to curved surfaces and the efficiency of the wetted shop towel and vacuuming for cleaning all surface textures. The mean percentage reduction in lead dust achieved by the traditional methods (vacuuming and wet wiping) was greater and more consistent compared to the new methods (electrostatic dry cloth and wet Swiffer mop). Vacuuming and wet wiping achieved lead reductions of 92% ± 4% and 91%, ± 4%, respectively, while the electrostatic dry cloth and wet Swiffer mops achieved lead reductions of only 89 ± 8% and  81 ± 17%, respectively.

  12. Quantitative analysis method for niobium in lead zirconate titanate

    International Nuclear Information System (INIS)

    Hara, Hideo; Hashimoto, Toshio

    1986-01-01

    Lead zirconate titanate (PZT) is a strong dielectric ceramic having piezoelectric and pyroelectric properties, and is used most as a piezoelectric material. Also it is a main component of lead lanthanum zirconate titanate (PLZT), which is a typical electrical-optical conversion element. Since these have been developed, the various electronic parts utilizing the piezoelectric characteristics have been put in practical use. The characteristics can be set up by changing the composition of PZT and the kinds and amount of additives. Among the additives, niobium has the action to make metallic ion vacancy in crystals, and by the formation of this vacancy, to ease the movement of domain walls in crystal grains, and to increase resistivity. Accordingly, it is necessary to accurately determine the niobium content for the research and development, quality control and process control. The quantitative analysis methods for niobium used so far have respective demerits, therefore, the authors examined the quantitative analysis of niobium in PZT by using an inductively coupled plasma emission spectro-analysis apparatus which has remarkably developed recently. As the result, the method of dissolving a specimen with hydrochloric acid and hydrofluoric acid, and masking unstable lead with ethylene diamine tetraacetic acid 2 sodium and fluoride ions with boric acid was established. The apparatus, reagents, the experiment and the results are reported. (Kako, I.)

  13. Synthesis of Lead Sulfide Nanoparticles by Chemical Precipitation Method

    International Nuclear Information System (INIS)

    Chongad, L S; Sharma, A; Banerjee, M; Jain, A

    2016-01-01

    Lead sulfide (PbS) nanoparticles were prepared by chemical precipitation method (CPM) with the assistance of H 2 S gas. The microstructure and morphology of the synthesized nanoparticles have been investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the PbS nanoparticles reveal formation of cubic phase. To investigate the quality of prepared nanoparticles, the particles size, lattice constant, strain, dislocation density etc. have been determined using XRD. TEM images reveal formation of cubic nanoparticles and the particle size determined from TEM images agree well with those from XRD. (paper)

  14. Method of handling of scrap lead from lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sytschev, A P; Kim, G V; Larin, V F; Sidorova, G D; Vicharev, I G; Kuur, V P; Achmetov, R S; Moiseev, G L; Maslov, V I; Kabatschek, V G

    1979-12-13

    Scrap lead and the casings of accumulators are mined and molten together in oxidixing atmosphere at a temperature of 1300 to 1500/sup 0/C. The lead oxide contained in the melt is then reduced to blue lead. Due to the combustion of the accumulator casings consisting of organic substances the fuel consumption in the melting process is reduced in accordance. The oxidizing atmosphere in the melting process is produced by use of air or oxygen.

  15. Lead line in rodents: an old sign of lead intoxication turned into a new method for environmental surveillance.

    Science.gov (United States)

    de Figueiredo, Fellipe Augusto Tocchini; Ramos, Junia; Kawakita, Erika R Hashimoto; Bilal, Alina S; de Sousa, Frederico B; Swaim, William D; Issa, Joao P Mardegan; Gerlach, Raquel F

    2016-11-01

    The "lead line" was described by Henry Burton in 1840. Rodents are used as sentinels to monitor environmental pollution, but their teeth have not been used to determine lead. To determine whether lead deposits can be observed in the teeth of lead-exposed animals, since the gingival deposits known as "lead line" would likely have a correlate in the calcified tissue to which the gums are opposed during life. Male Wistar rats were exposed to lead in the drinking water (30 mg/L) since birth until 60 days-old. Molars and the incisors of each hemimandible were analyzed by scanning electron microscopy (SEM) on regular and backscattered electrons (BSE) mode. Elements were determined using electron dispersive spectroscopy (EDS). Clean cervical margins were observed on control teeth, as opposed to the findings of extensive deposits on lead-exposed animals, even in hemimandibles that had been exhumed after being buried for 90 days. BSE/EDS indicated that those deposits were an exogenous material compatible with lead sulfite. Presence of calcium, phosphorus, magnesium, carbon, lead, and oxygen is presented. Lead-exposed animals presented marked root resorption. The lead deposits characterized here for the first time show that the "lead line" seen in gums has a calcified tissue counterpart, that is detectable post-mortem even in animals exposed to a low dose of lead. This is likely a good method to detect undue lead exposure and will likely have wide application for pollution surveillance using sentinels.

  16. Quantum confinement of lead titanate nanocrystals by wet chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Kaviyarasu, K., E-mail: kaviyarasuloyolacollege@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Manikandan, E., E-mail: maniphysics@gmail.com [Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Central Research Laboratory, Sree Balaji Medical College & Hospital, Bharath University, Chrompet, Chennai, Tamil Nadu (India); Nuru, Z.Y. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa); Maaza, M., E-mail: likmaaz@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department (MSD), iThemba LABS-National Research Foundation - NRF, 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province (South Africa)

    2015-11-15

    Lead Titanate (PbTiO{sub 3)} is a category of the practical semiconductor metal oxides, which is widely applied in various scientific and industrial fields because of its catalytic, optical, and electrical properties. PbTiO{sub 3} nanocrystalline materials have attracted a wide attention due to their unique properties. PbTiO{sub 3} nanocrystals were investigated by X-ray diffraction (XRD) to identify the PbTiO{sub 3} nanocrystals were composed a tetragonal structure. The diameter of a single sphere was around 20 nm and the diameter reached up to 3 μm. The chemical composition of the samples and the valence states of elements were determined by X-ray photoelectron spectroscopy (XPS) in detail. - Highlights: • Single crystalline NSs of PbTiO{sub 3} fabricated by wet chemical method. • PbTiO{sub 3} NSs were uniform and continuous along the long axis. • Tetragonal perovskite structure with the diameter 20 nm and length 3 μm. • XPS spectrum was fitted with Lorentzian function respectively. • The size of the images is also 10 μm × 10 μm.

  17. Two-step extraction method for lead isotope fractionation to reveal anthropogenic lead pollution.

    Science.gov (United States)

    Katahira, Kenshi; Moriwaki, Hiroshi; Kamura, Kazuo; Yamazaki, Hideo

    2018-05-28

    This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios. The results showed that the method was useful to discuss the Pb sources and that anthropogenic Pb in the sediment samples analysed was mainly derived from China because of transboundary air pollution.

  18. 40 CFR Appendix B to Part 80 - Test Methods for Lead in Gasoline

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Test Methods for Lead in Gasoline B... in Gasoline Method 1—Standard Method Test for Lead in Gasoline by Atomic Absorption Spectrometry 1. Scope. 1.1. This method covers the determination of the total lead content of gasoline. The procedure's...

  19. A simple lead dust fall method predicts children's blood lead level: New evidence from Australia.

    Science.gov (United States)

    Gulson, Brian; Taylor, Alan

    2017-11-01

    We have measured dust fall accumulation in petri dishes (PDD) collected 6 monthly from inside residences in Sydney urban area, New South Wales, Australia as part of a 5-year longitudinal study to determine environmental associations, including soil. with blood lead (PbB) levels. The Pb loading in the dishes (n = 706) had geometric means (GM) of 24µg/m 2 /30d, a median value of 22µg/m 2 /30d with a range from 0.2 to 11,390µg/m 2 /30d. Observed geometric mean PbB was 2.4µg/dL at ages 2-3 years. Regression analyses showed a statistically significant relationship between predicted PbB and PDD. The predicted PbB values from dust in our study are consistent with similar analyses from the US in which floor dust was collected by wipes. Predicted PbB values from PDD indicate that an increase in PDD of about 100µg/m 2 /30d would increase PbB by about 1.5µg/dL or a doubling PbB at the low levels currently observed in many countries. Predicted PbB values from soil indicate that a change from 0 to 1000mg Pb/kg results in an increase of 1.7µg/dL in PbB, consistent with earlier investigations. Blood Pb levels can be predicted from dust fall accumulation (and soil) in cases where blood sampling is not always possible, especially in young children. Petri dish loading data could provide an alternative or complementary "action level" at about 100µg Pb/m 2 /30 days, similar to the suggested level of about 110µg Pb/m 2 for surface wipes, for use in monitoring activities such as housing rehabilitation, demolition or soil resuspension. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. An experimental design method leading to chemical Turing patterns.

    Science.gov (United States)

    Horváth, Judit; Szalai, István; De Kepper, Patrick

    2009-05-08

    Chemical reaction-diffusion patterns often serve as prototypes for pattern formation in living systems, but only two isothermal single-phase reaction systems have produced sustained stationary reaction-diffusion patterns so far. We designed an experimental method to search for additional systems on the basis of three steps: (i) generate spatial bistability by operating autoactivated reactions in open spatial reactors; (ii) use an independent negative-feedback species to produce spatiotemporal oscillations; and (iii) induce a space-scale separation of the activatory and inhibitory processes with a low-mobility complexing agent. We successfully applied this method to a hydrogen-ion autoactivated reaction, the thiourea-iodate-sulfite (TuIS) reaction, and noticeably produced stationary hexagonal arrays of spots and parallel stripes of pH patterns attributed to a Turing bifurcation. This method could be extended to biochemical reactions.

  1. Different partial volume correction methods lead to different conclusions

    DEFF Research Database (Denmark)

    Greve, Douglas N; Salat, David H; Bowen, Spencer L

    2016-01-01

    A cross-sectional group study of the effects of aging on brain metabolism as measured with (18)F-FDG-PET was performed using several different partial volume correction (PVC) methods: no correction (NoPVC), Meltzer (MZ), Müller-Gärtner (MG), and the symmetric geometric transfer matrix (SGTM) usin...

  2. Diffusivity, activity and solubility of oxygen in liquid lead and lead-bismuth eutectic alloy by electrochemical methods

    International Nuclear Information System (INIS)

    Ganesan, Rajesh; Gnanasekaran, T.; Srinivasa, Raman S.

    2006-01-01

    The diffusivity of oxygen in liquid lead and lead-bismuth eutectic (LBE) alloy was measured by a potentiostatic method and is given by log(D O Pb /cm 2 s -1 )=-2.554-2384/T(+/-0.070), 818-1061K, and log(D O LBE /cm 2 s -1 )=-0.813-3612/T(+/-0.091), 811-980K. The activity of oxygen in lead and LBE was determined by coulometric titration experiments. Using the measured data, the standard free energy of dissolution of oxygen in liquid lead and LBE was derived and is given byG O(Pb) xs =-121349+16.906T(+/-560)J(gatomO) -1 ,815-1090K,G O(LBE) xs = -127398+27.938T(+/-717)J(gatomO) -1 ,812-1012K.Using the above data, the Gibbs energy of formation of PbO(s) and equilibrium oxygen pressures measured over the oxygen-saturated LBE alloy, the solubility of oxygen in liquid lead and LBE were derived. The solubility of oxygen in liquid lead and LBE are given by log(S/at.%O)=-5100/T+4.32 (+/-0.04), 815-1090K and log(S/at.%O)=-4287/T+3.53 (+/-0.06), 812-1012K respectively.

  3. Experimental substantiation of separation techniques of lead and uranium microamounts using isotopic dilution method as control method

    International Nuclear Information System (INIS)

    Agapova, A.A.; Shcherbinina, N.K.

    1983-01-01

    Methods,ensuring at low levels of contamination a high degree of lead and uranium microamount separation from solutions of geological samples, have been selected and subjected to the detailed testing. The method of isotope dilution, , combining high accuracy and sensitivity of determinations, is used as the main control methods, is used as the main control method. Using the method, processe es of uranium extpaction are traced, special attention is paid to the detailed description of lead extraction at all the stages of the methods selected. Opera ations of ion exchange for lead and uranium in microcolumns with the Bio-Rad r sin are considered, as well as operations of lead electrolytic separation. The chemical procedures suggested permit to solve one of the main methodical tasks f sample preparation, containing microgram amounts of lead and uranium, for high h-prcision measurement of their isotope composition using mass-spectrometric method

  4. Lead-lead isotope method. Application to migmatites and associaded rocks of the region of Sao Jose dos Campos, SP

    International Nuclear Information System (INIS)

    Babinski, M.

    1988-01-01

    Establishment of chemical and analytical procedures, preparation and purification of reagents and the mounting of a clean laboratory (class 100) for the Pb-Pb isotope dating of whole rock and mineral samples are discussed in this work. Two different methods of dissolution of rock samples and chemical separation of lead using anionic resin were tried in a conventional chemical laboratory using analytical grade reagents. The samples analysed were paleossome and neossome of migmatites from Sao Jose dos Campos, SP, and from the results obtained the analytical method to be employed was chosen. The results obtained by this method agree well with those of the Geochronology Laboratory at Oxford, for the same samples. Applying the established analytical procedure, migmatites and associated gneisses from the region of Sao Jose dos Campos were dated by Pb/Pb method. Some of the samples were also dated by Rb-Sr method. The lead-lead isochron age of 2355 +- 85 M.a. (μ 1 = 8.33) for the paleossome may be interpreted as the age of the metamorphism for these rocks, which were formed probably during the Archean. The age data for the phacoidal gneisses show a similar geological evolution, whereas the 2414 +- 800 M.A. Pb-Pb isochron age for the protomylonitic gneisses indicates a disturbed Pb-Pb isotope system. The neossome samples define a Pb-Pb isochron age of 1388 +- 290 M.A. (μ1 = 8.15), which may be interpreted as the age of migmatization. The calculated Pb-Pb ages for two alkali feldspars from the migmatites are devoid of any geological significance. The age values obtained by the Rb-Sr isotope system for the neossome and paleossome of the migmatites agree with the Pb/Pb data within experimental errors. However, the study shows that results of the Rb-Sr data alone cannot be interpreted unambiguously with out comparison with data from other isotope systems. (author) [pt

  5. Method for a Leading Edge Slat on a Wing of an Aircraft

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2016-01-01

    A method for managing a flight control surface system. A leading edge device is moved on a leading edge from an undeployed position to a deployed position. The leading edge device has an outer surface, an inner surface, and a deformable fairing attached to the leading edge device such that the deformable fairing covers at least a portion of the inner surface. The deformable fairing changes from a deformed shape to an original shape when the leading edge device is moved to the deployed position. The leading edge device is then moved from the deployed position to the undeployed position, wherein the deformable fairing changes from the original shape to the deformed shape.

  6. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    Energy Technology Data Exchange (ETDEWEB)

    He, Yu, E-mail: heyuyhe@gmail.com; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann [Network for Computational Nanotechnology, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-11-24

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si{sub 0.5}Ge{sub 0.5}. It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si{sub 0.5}Ge{sub 0.5} transistors by 45% compared to conventional lead methods.

  7. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    Science.gov (United States)

    He, Yu; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann

    2014-11-01

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si0.5Ge0.5. It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si0.5Ge0.5 transistors by 45% compared to conventional lead methods.

  8. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    International Nuclear Information System (INIS)

    He, Yu; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann

    2014-01-01

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si 0.5 Ge 0.5 . It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si 0.5 Ge 0.5 transistors by 45% compared to conventional lead methods

  9. Application of the radioreagent method to the determination of trace quantities of lead

    International Nuclear Information System (INIS)

    Figueiredo, A.M.G.; Saiki, M.; Lima, F.W. de

    1983-01-01

    The radioreagent method of analysis was applied to determine trace quantities of lead in several types of samples. This method is based on the extraction of radioactive cobalt, displaced by lead from the cobalt chelate of ethylenediaminetetraacetate labeled with 60 Co, into a tetracycline-benzyl alcohol solution. The radioactivity of the released cobalt, extracted into the organic phase, measured by menas of a single channel gamma-ray analyzer coupled to a Na(T1) scintillation detector, is proportional to the lead concentration. The elements which might interfere with the analysis were removed by a chemical separation procedure of lead using dithizone. The method was applied for lead determination in air samples, gasoline and samples from the International Atomic Energy Agency, namely: simulated air filter (Air-3), fresh water (W-3), dried animal whole blood(A-2) and calcinated animal bone (A3/1). The sensitivity, accuracy and precision of the method were also discussed. (Author) [pt

  10. Lead titanate nanotubes synthesized via ion-exchange method: Characteristics and formation mechanism

    International Nuclear Information System (INIS)

    Song Liang; Cao Lixin; Li Jingyu; Liu Wei; Zhang Fen; Zhu Lin; Su Ge

    2011-01-01

    Highlights: → Lead titanate nanotubes PbTi 3 O 7 were firstly synthesized by ion-exchange method. → Sodium titanate nanotubes have ion exchangeability. → Lead titanate nanotubes show a distinct red shift on absorption edge. - Abstract: A two-step method is presented for the synthesis of one dimensional lead titanate (PbTi 3 O 7 ) nanotubes. Firstly, titanate nanotubes were prepared by an alkaline hydrothermal process with TiO 2 nanopowder as precursor, and then lead titanate nanotubes were formed through an ion-exchange reaction. We found that sodium titanate nanotubes have ion exchangeability with lead ions, while protonated titanate nanotubes have not. For the first time, we distinguished the difference between sodium titanate nanotubes and protonated titanate nanotubes in the ion-exchange process, which reveals a layer space effect of nanotubes in the ion-exchange reaction. In comparison with sodium titanate, the synthesized lead titanate nanotubes show a narrowed bandgap.

  11. Superior Reproducibility of the Leading to Leading Edge and Inner to Inner Edge Methods in the Ultrasound Assessment of Maximum Abdominal Aortic Diameter

    DEFF Research Database (Denmark)

    Borgbjerg, Jens; Bøgsted, Martin; Lindholt, Jes S

    2018-01-01

    Objectives: Controversy exists regarding optimal caliper placement in ultrasound assessment of maximum abdominal aortic diameter. This study aimed primarily to determine reproducibility of caliper placement in relation to the aortic wall with the three principal methods: leading to leading edge...

  12. Application of radio-reagent method in the determination of lead trace amounts

    International Nuclear Information System (INIS)

    Figueiredo, A.M.G.

    1983-01-01

    A radiometric method for trace analysis of lead was established, based on the displacement reaction between lead and the complex cobalt - ethylenediaminetetracetate labelled with 60 Co (Co* - EDTA), which is named radioreagent. The radioactive cobalt displaced by lead is separated from the excess of radioreagent by the solvent extraction technique, using a solution of tetracycline (Tc) in benzyl alcohol. The activity of the extracted cobalt is then measured by means of a single-channel gamma-ray analyser coupled to a NaI (Tl) scintillation detector, the activity being proportional to the lead concentration, in a range from 2.5 to 150 μg. The interference of several elements (V, Th, Sc, Fe, La, Yb, Cu, Cd, Zn, Mn, Ni, Co, Al and Sn) was investigated by means of a previous separation between lead and these interfering elements. The analyses of artificial samples containing lead and the interfering elements gave a yield of 91.1 + - 3.2 %. The detection limit achieved by the method was 3.3 μg of lead. The radioreagent method was applied to lead analysis of samples from IAEA, namely: simulated air filter (Air-3), fresh water (W-3), dried animal blood (A-2) and calcinated animal bone (A-3/1). Lead was also determined in gasoline samples and air samples, these latter collected in the surroundings of the IPEN/CNEN/SP (Brazil). (Author) [pt

  13. A combined method to estimate the appropriate age value of closed uraniun-lead system

    International Nuclear Information System (INIS)

    Malakhov, S.S.

    1982-01-01

    A new method is proposed for obtaining the appropriate age values of closed uranium-lead systems taking into account total indeependent information delivered as a result of spectral and isotope-lead analyses. A simple mathematical apparatus which permits to perform a geochronological interpretation of samples using miniature computers is considered and suggested. A simple estimation formula for determining the age of uranium-lead systems under the assumption of model development of isotope ratios of ordinary lead is derived and tested basing on the facts

  14. Method and Apparatus for a Leading Edge Slat on a Wing of an Aircraft

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2013-01-01

    A method and apparatus for managing a flight control surface system. A leading edge device is moved on a leading edge from an undeployed position to a deployed position. The leading edge device has an outer surface, an inner surface, and a deformable fairing attached to the leading edge device such that the deformable fairing covers at least a portion of the inner surface. The deformable fairing changes from a deformed shape to an original shape when the leading edge device is moved to the deployed position. The leading edge device is then moved from the deployed position to the undeployed position, wherein the deformable fairing changes from the original shape to the deformed shape.

  15. The adjoint method for general EEG and MEG sensor-based lead field equations

    International Nuclear Information System (INIS)

    Vallaghe, Sylvain; Papadopoulo, Theodore; Clerc, Maureen

    2009-01-01

    Most of the methods for the inverse source problem in electroencephalography (EEG) and magnetoencephalography (MEG) use a lead field as an input. The lead field is the function which relates any source in the brain to its measurements at the sensors. For complex geometries, there is no analytical formula of the lead field. The common approach is to numerically compute the value of the lead field for a finite number of point sources (dipoles). There are several drawbacks: the model of the source space is fixed (a set of dipoles), and the computation can be expensive for as much as 10 000 dipoles. The common idea to bypass these problems is to compute the lead field from a sensor point of view. In this paper, we use the adjoint method to derive general EEG and MEG sensor-based lead field equations. Within a simple framework, we provide a complete review of the explicit lead field equations, and we are able to extend these equations to non-pointlike sensors.

  16. Method of determining paper-deposited materials, eg. lead, by their reaction with radioactive krypton

    International Nuclear Information System (INIS)

    Tolgyessy, J.; Pruzinec, J.

    1976-01-01

    The invention claims a method of determining substances on a paper carrier based on the substance reaction with 85 Kr gas and the measurement of radioactivity of the kryptonate formed. Lead is shown as an example. Different amounts of lead acetate were deposited on Whatman 2 chromatographic paper as was an unknown sample of Pb salt. The paper was exposed to a 2.5 mCi 85 Kr atmosphere for 48 hours. The activity of the individual spots was then measured, a calibration curve established and the amount of lead in the analyzed sample read-out. (Ha)

  17. Virtual screening methods as tools for drug lead discovery from large chemical libraries.

    Science.gov (United States)

    Ma, X H; Zhu, F; Liu, X; Shi, Z; Zhang, J X; Yang, S Y; Wei, Y Q; Chen, Y Z

    2012-01-01

    Virtual screening methods have been developed and explored as useful tools for searching drug lead compounds from chemical libraries, including large libraries that have become publically available. In this review, we discussed the new developments in exploring virtual screening methods for enhanced performance in searching large chemical libraries, their applications in screening libraries of ~ 1 million or more compounds in the last five years, the difficulties in their applications, and the strategies for further improving these methods.

  18. Computational Methods Used in Hit-to-Lead and Lead Optimization Stages of Structure-Based Drug Discovery.

    Science.gov (United States)

    Heifetz, Alexander; Southey, Michelle; Morao, Inaki; Townsend-Nicholson, Andrea; Bodkin, Mike J

    2018-01-01

    GPCR modeling approaches are widely used in the hit-to-lead (H2L) and lead optimization (LO) stages of drug discovery. The aims of these modeling approaches are to predict the 3D structures of the receptor-ligand complexes, to explore the key interactions between the receptor and the ligand and to utilize these insights in the design of new molecules with improved binding, selectivity or other pharmacological properties. In this book chapter, we present a brief survey of key computational approaches integrated with hierarchical GPCR modeling protocol (HGMP) used in hit-to-lead (H2L) and in lead optimization (LO) stages of structure-based drug discovery (SBDD). We outline the differences in modeling strategies used in H2L and LO of SBDD and illustrate how these tools have been applied in three drug discovery projects.

  19. Asynchronous Gossip-Based Gradient-Free Method for Multiagent Optimization

    OpenAIRE

    Deming Yuan

    2014-01-01

    This paper considers the constrained multiagent optimization problem. The objective function of the problem is a sum of convex functions, each of which is known by a specific agent only. For solving this problem, we propose an asynchronous distributed method that is based on gradient-free oracles and gossip algorithm. In contrast to the existing work, we do not require that agents be capable of computing the subgradients of their objective functions and coordinating their...

  20. Hydrogen extraction from liquid lithium-lead alloy by gas-liquid contact method

    International Nuclear Information System (INIS)

    Xie Bo; Weng Kuiping; Hou Jianping; Yang Guangling; Zeng Jun

    2013-01-01

    Hydrogen extraction experiment from liquid lithium-lead alloy by gas-liquid contact method has been carried out in own liquid lithium-lead bubbler (LLLB). Experimental results show that, He is more suitable than Ar as carrier gas in the filler tower. The higher temperature the tower is, the greater hydrogen content the tower exports. Influence of carrier gas flow rate on the hydrogen content in the export is jagged, no obvious rule. Although the difference between experimental results and literature data, but it is feasible that hydrogen isotopes extraction experiment from liquid lithium-lead by gas-liquid contact method, and the higher extraction efficiency increases with the growth of the residence time of the alloy in tower. (authors)

  1. Comparison of methods for certification of stannic, stibium and lead traces in reference materials for steel

    Directory of Open Access Journals (Sweden)

    I. V. Khodakovskaya

    2016-01-01

    Full Text Available Development and introduction of new metallurgical technologies, new additional chemical compound indexes controlled in metallurgical materials demand to develop the new, more advanced methods of analytical control. The particular attention should be paid to identify the traces of stannic, stinium and lead because of their influence on metal characteristics.

  2. Utilizing the Lead User Method for Promoting Innovation in E-Recuiting

    NARCIS (Netherlands)

    Furtmueller-Ettinger, Elfriede; Wilderom, Celeste P.M.; van Dick, Rolf; Bondarouk, Tatiana; Ruel, Hubertus Johannes Maria; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    2009-01-01

    In order to maintain their customer base, many e-recruiting firms are in need of developing innovations. The Lead User (LU) Method has been heralded in the new product innovation literature but not yet applied often in e-service settings. Based on an e-recruiting portal, the authors compare new

  3. Outside corner and method of making in the making lead brick (plain brick) using rotary table

    International Nuclear Information System (INIS)

    Muhammad Awwaluddin; Samuel Praptoyo

    2009-01-01

    It has been developed a tool that can be used for defining angles on the fabrication of lead bricks. The angles are both outside of the lead bricks that correspond to male and female shape respectively. The lead bricks should be in accordance to ISO 7212-1986 standard which has angle tolerance 90° 0 +15 for male and 90° 0 -15 for female. The accuracy of these angles is very important to maintain the equilibrium position of the bricks so that their arrangement will not lining or collapse. A rotary table is used for the fabrication to make easier in setting up any related working apparatus and to have precision measurement result. However, a lot of operator do not know yet how to operate such a rotary table to produce angle with such an eligible tolerance. Therefore, a method of measurement in machining lead brick process using a rotary table is necessarily required. This method will be used as a reference to have angle accuracy of 0,03° in producing outside and inside angles or male and female lead bricks. (author)

  4. Synthesis of uniform nano-structured lead oxide by sonochemical method and its application as cathode and anode of lead-acid batteries

    International Nuclear Information System (INIS)

    Karami, Hassan; Karimi, Mohammad Ali; Haghdar, Saeed

    2008-01-01

    This paper discusses the results of a research aimed at investigating the synthesis of nano-structured lead oxide through reaction of lead nitrate solution and sodium carbonate solution by the sonochemical method. At the first, lead carbonate was obtained in a synthesized solution and then, after filtration, it was calcinated at the temperature of 320 deg. C so that nano-structured lead oxide can be produced. The effects of different parameters on particle size and morphology of final lead oxide powder were optimized by a 'one at a time' method. The prepared lead oxide powder was characterized by scanning electron microscopy (SEM), transmission electron spectroscopy (TEM) and X-ray diffraction (XRD). Under optimum conditions, uniformed and homogeneous nano-structured lead oxide powder with more spongy morphology and particle size of 20-40 nm was obtained. The synthesized lead oxide, as anode and cathode of lead-acid batteries, showed an excellent discharge capacity (140 mA h/g)

  5. A Decomposition-Based Pricing Method for Solving a Large-Scale MILP Model for an Integrated Fishery

    Directory of Open Access Journals (Sweden)

    M. Babul Hasan

    2007-01-01

    The IFP can be decomposed into a trawler-scheduling subproblem and a fish-processing subproblem in two different ways by relaxing different sets of constraints. We tried conventional decomposition techniques including subgradient optimization and Dantzig-Wolfe decomposition, both of which were unacceptably slow. We then developed a decomposition-based pricing method for solving the large fishery model, which gives excellent computation times. Numerical results for several planning horizon models are presented.

  6. Removal of lead ions from industrial waste water by using biomaterials – a novel method

    Directory of Open Access Journals (Sweden)

    Malairajan Singanan

    2005-12-01

    Full Text Available A simple cost effective and eco-friendly method for the remediation of lead from industrial wastewater has been investigated. A novel biomaterial, Tridax procumbens (Asteraceae a medicinal plant, was used for the removal of lead ions from synthetic wastewater and the method was also applied for real sample analysis. The operational pH of the experimental solution was fixed as 4.5. The optimum amount of bioadsorbent was 3.5 g. The Pb(II ions removal efficiency of the raw bioadsorbent was also determined. The removal efficiency of the activated carbon of the bioadsorbent was excellent. 98 % removal of Pb(II ions was achieved at the dose rate of 3.5 g. The optimum contact time was estimated to be 160 minutes.

  7. A fence barrier method of leading edge cell capture for explorative biochemical research.

    Science.gov (United States)

    Wager, Lucas J; Murray, Rachael Z; Thompson, Erik W; Leavesley, David I

    2017-09-03

    The scratch or wound-healing assay is used ubiquitously for investigating re-epithelialisation and has already revealed the importance of cells comprising the leading edge of healing epithelial wounds. However it is currently limited to studying the effect of known biochemical agents on the tissue of choice. Here we present an adaptation that extends the utility of this model to encompass the collection of cells from the leading edge of migrating epithelial sheets making available explorative biochemical analyses. The method is scalable and does not require expensive apparatus, making it suitable for large and small laboratories alike. We detail the application of our method and exemplify proof of principle data derived from primary human keratinocyte cultures.

  8. A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators.

    Science.gov (United States)

    Du, Junwei; Schmall, Jeffrey P; Judenhofer, Martin S; Di, Kun; Yang, Yongfeng; Cherry, Simon R

    2017-09-01

    The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 - 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 -650 keV energy window) and 670.2 ± 16.2 ps (250-750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 - 650 keV) and 413.7 ± 0.9 ps (250 - 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 - 650 keV) and 476.0 ± 13.0 ps (250 - 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 - 650 keV) and 413.4 ± 0.9 ps (250 - 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained

  9. Application of proton-induced X-ray emission method to determination of lead content in blood

    International Nuclear Information System (INIS)

    Slominska, D.; Jarczyk, L.; Rokita, E.; Strzalkowski, A.; Losiowski, A.; Macheta, A.; Sych, M.; Moszkowicz, S.

    1979-01-01

    The proton induced X-ray emission method is applied for determination of lead content in the blood of the people exposed to contact with ethyline vapours and people working in lead-zinc works. (author)

  10. Gap energy studied by optical transmittance in lead iodide monocrystals grown by Bridgman's Method

    Directory of Open Access Journals (Sweden)

    Veissid N.

    1999-01-01

    Full Text Available The bandgap energy as a function of temperature has been determined for lead iodide. The monocrystal was obtained in a vacuum sealed quartz ampoule inside a vertical furnace by Bridgman's method. The optical transmittance measurement enables to evaluate the values of Eg. By a fitting procedure of Eg as a function of temperature is possible to extract the parameters that govern its behavior. The variation of Eg with temperature was determined as: Eg(T = Eg(0 - aT2/(a + T, with: Eg(0 = (2.435 ± 0.008 eV, a = (8.7 ± 1.3 x 10-4 eV/K and a = (192 ± 90 K. The bandgap energy of lead iodide at room temperature was found to be 2.277 ± 0.007 eV.

  11. Low temperature synthesis & characterization of lead-free BCZT ceramics using molten salt method

    Science.gov (United States)

    Jai Shree, K.; Chandrakala, E.; Das, Dibakar

    2018-04-01

    Piezoelectric properties are greatly influenced by the synthesis route, microstructure, stoichiometry of the chemical composition, purity of the starting materials. In this study, molten salt method was used to prepare lead-free BCZT ceramics. Molten salt method is one of the simplestmethods to prepare chemically-purified, single phase powders in high yield often at lower temperatures and shorten reaction time. Calcination of the molten salt synthesized powders resulted in asingle-phase perovskite structure at 1000 °C which is ˜ 350 °C less than the conventional solid-sate reaction method. With increasing calcination temperature the average template size was increased (˜ 0.5-2 µm). Formation of well dispersive templates improves the sinterability at lower temperatures. Lead-free BCZT ceramics sintered at 1500 °C for 2 h resulted in homogenous and highly dense microstructure with ˜92% of the theoretical density and a grain size of ˜ 35 µm. This highly dense microstructure could enhance the piezoelectric properties of the system.

  12. Efficient decomposition and linearization methods for the stochastic transportation problem

    International Nuclear Information System (INIS)

    Holmberg, K.

    1993-01-01

    The stochastic transportation problem can be formulated as a convex transportation problem with nonlinear objective function and linear constraints. We compare several different methods based on decomposition techniques and linearization techniques for this problem, trying to find the most efficient method or combination of methods. We discuss and test a separable programming approach, the Frank-Wolfe method with and without modifications, the new technique of mean value cross decomposition and the more well known Lagrangian relaxation with subgradient optimization, as well as combinations of these approaches. Computational tests are presented, indicating that some new combination methods are quite efficient for large scale problems. (authors) (27 refs.)

  13. Study on residual discharge time of lead-acid battery based on fitting method

    Science.gov (United States)

    Liu, Bing; Yu, Wangwang; Jin, Yueqiang; Wang, Shuying

    2017-05-01

    This paper use the method of fitting to discuss the data of C problem of mathematical modeling in 2016, the residual discharge time model of lead-acid battery with 20A,30A,…,100A constant current discharge is obtained, and the discharge time model of discharge under arbitrary constant current is presented. The mean relative error of the model is calculated to be about 3%, which shows that the model has high accuracy. This model can provide a basis for optimizing the adaptation of power system to the electrical motor vehicle.

  14. All roads lead to Rome - New search methods for the optimal triangulation problem

    Czech Academy of Sciences Publication Activity Database

    Ottosen, T. J.; Vomlel, Jiří

    2012-01-01

    Roč. 53, č. 9 (2012), s. 1350-1366 ISSN 0888-613X R&D Projects: GA MŠk 1M0572; GA ČR GEICC/08/E010; GA ČR GA201/09/1891 Grant - others:GA MŠk(CZ) 2C06019 Institutional support: RVO:67985556 Keywords : Bayesian networks * Optimal triangulation * Probabilistic inference * Cliques in a graph Subject RIV: BD - Theory of Information Impact factor: 1.729, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/vomlel-all roads lead to rome - new search methods for the optimal triangulation problem.pdf

  15. SPECIFIC MANAGEMENT AND LEADING METHODS APPLIED TO BUTTERFLY TOURISM FOR 2012

    Directory of Open Access Journals (Sweden)

    Eugenia ALECU

    2013-12-01

    Full Text Available In this paper are explained the most important management elements for managers and employees of a tour operator agency. The study showed in a concrete and realistic manner how a manager of a tour operator agency can lead, control, predict and determine the prospects utilizing a specific management method called dashboard. Given the competition in the field of tourism, Butterfly Tourism is trying to manage its business in a professional manner and offer attractive packages and favorable prices to its customers.

  16. A novel method for direct solder bump pull testing using lead-free solders

    Science.gov (United States)

    Turner, Gregory Alan

    This thesis focuses on the design, fabrication, and evaluation of a new method for testing the adhesion strength of lead-free solders, named the Isotraction Bump Pull method (IBP). In order to develop a direct solder joint-strength testing method that did not require customization for different solder types, bump sizes, specific equipment, or trial-and-error, a combination of two widely used and accepted standards was created. First, solder bumps were made from three types of lead free solder were generated on untreated copper PCB substrates using an in-house fabricated solder bump-on-demand generator, Following this, the newly developed method made use of a polymer epoxy to encapsulate the solder bumps that could then be tested under tension using a high precision universal vertical load machine. The tests produced repeatable and predictable results for each of the three alloys tested that were in agreement with the relative behavior of the same alloys using other testing methods in the literature. The median peak stress at failure for the three solders tested were 2020.52 psi, 940.57 psi, and 2781.0 psi, and were within one standard deviation of the of all data collected for each solder. The assumptions in this work that brittle fracture occurred through the Intermetallic Compound layer (IMC) were validated with the use of Energy-Dispersive X-Ray Spectrometry and high magnification of the fractured surface of both newly exposed sides of the test specimens. Following this, an examination of the process to apply the results from the tensile tests into standard material science equations for the fracture of the systems was performed..

  17. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Alexandre H. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Souza, Flavio L., E-mail: flavio.souza@ufabc.edu.br [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia 166, Bangu, Santo Andre, SP 09210-170 (Brazil); Chiquito, Adenilson J., E-mail: chiquito@df.ufscar.br [Departamento de Fisica, UFSCar-Federal University of Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Longo, Elson, E-mail: elson@iq.unesp.br [Instituto de Quimica de Araraquara, UNESP-Universidade Estadual Paulista, Rua Francisco Degni, CP 355 Araraquara, SP 14801-907 (Brazil); Leite, Edson R., E-mail: derl@power.ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Camargo, Emerson R., E-mail: camargo@ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil)

    2010-12-01

    Nanosized powders of lead lanthanum titanate (Pb{sub 1-x}La{sub x}TiO{sub 3}) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

  18. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Pinto, Alexandre H.; Souza, Flavio L.; Chiquito, Adenilson J.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

    2010-01-01

    Nanosized powders of lead lanthanum titanate (Pb 1-x La x TiO 3 ) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

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

    International Nuclear Information System (INIS)

    Smith, Leon E.; Anderson, Kevin K.; Gesh, Christopher J.; Shaver, Mark W.

    2010-01-01

    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.

  20. Application of risk analysis and quality control methods for improvement of lead molding process

    Directory of Open Access Journals (Sweden)

    H. Gołaś

    2016-10-01

    Full Text Available The aim of the paper is to highlight the significance of implication of risk analysis and quality control methods for the improvement of parameters of lead molding process. For this reason, Fault Mode and Effect Analysis (FMEA was developed in the conceptual stage of a new product TC-G100-NR. However, the final product was faulty (a complete lack of adhesion of brass insert to leak regardless of the previously defined potential problem and its preventive action. It contributed to the recognition of root causes, corrective actions and change of production parameters. It showed how these methods, level of their organization, systematic and rigorous study affect molding process parameters.

  1. Development of stable solidification methods for toxic lead oxide in radioactive wastes

    International Nuclear Information System (INIS)

    Hitoshi Mimura; Shingo Ikeda; Yuichi Niibori

    2009-01-01

    The objective of this study is to develop the advanced solidification methods for the toxic lead oxide contained in radioactive wastes and to examine their chemical durability in terms of leachability and surface alteration; the solidification characteristics and leachability for the following three kinds of solidified products immobilizing lead were examined, and the experimental results were summarized as follows. (a) Mineral solidified products: A-zeolite or fly ash (FA) was used as a binder, and NaAlO 2 and Na 2 SiO 3 were mixed as additives. The leachability of lead ions in pure water was considerably lowered by the heat treatment at higher temperature (1,000 degree C), and the concentration of lead ions leached was under criterion value of 0.3 mg/l. The products prepared by mixing A-zeolite and fly ash also had low leachability under 0.3 mg/l even in the saturated Ca(OH)2 solution. (b) Melted solidified products: A-zeolite or fly ash was used as a binder and glass-forming reagents of B 2 O 3 and NaH 2 PO 4 were used as additives. The XRD peaks assigned PbO were not observed in all products. The products for the mixtures of FA:NaH 2 PO 4 :PbO (2:2:1 and 3:1:1) had low leachability under criterion value in both leachants of deionized water and saturated Ca(OH) 2 solution. (c) Phosphate ceramics products: the chemically bonded phosphate ceramics were produced by using MgKPO 4 , MgHPO 4 , Zr(HPO 4 ) 2 , potassium iron phosphate and sodium iron phosphate, and FA was used as additives. In particular, by using MgHPO 4 , the leachability of the products was lowered less than 0.3 mg/l in both leachants. The phosphate ceramics products and melted solidified products are favorable as the waste solid forms immobilizing lead. In particular, novel ceramics products have advantages in the simple solidification procedure similarly to the cement products. As for mineral solidification, natural zeolites and FA as binder also useful from the viewpoint of cost efficiency

  2. Synthesis and characterization of lead zirconate titanate powders obtained by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Emerson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod. Washington Luis km 235, CP 676, Sao Carlos SP, 13565-905 (Brazil)], E-mail: camargo@ufscar.br; Leite, Edson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod. Washington Luis km 235, CP 676, Sao Carlos SP, 13565-905 (Brazil)], E-mail: derl@power.ufscar.br; Longo, Elson [Department of Biochemistry, Chemistry Institute of Araraquara, UNESP, Sao Paulo State University Rua Francisco Degni, CP 355 Araraquara SP, 14801-907 Brazil (Brazil)], E-mail: elson@iq.unesp.br

    2009-02-05

    Lead zirconate titanate (PbZr{sub 1-x}Ti{sub x}O{sub 3}) was synthesized by the 'oxidant peroxo method (OPM)' with 'x' between 0.25 and 0.50. Titanium metal was dissolved into a hydrogen peroxide/ammonia aqueous solution, followed by the addition of lead and zirconium nitrate solution. The amorphous precipitated precursor obtained was crystallized by heat treatment between 400 and 1000 deg. C. Images of transmission microscopy showed spherical particles with average diameter between 20 and 60 nm, and the presence of necks between particles treated at 700 deg. C. All of the unpressed powders were characterized by X-ray diffractometry and FT-Raman spectroscopy. Powder samples with 'x' up to 0.35 showed rhombohedral structure when treated at temperatures higher than 500 deg. C, and tetragonal structure when 'x' was higher than 0.40. Analysis of XRD and Raman spectroscopy of the precursor powders showed amorphous-like structures, however powders treated at 400 deg. C showed a structure identified as an intermediate pyrochlore phase, independently of the Zr and Ti mole ratio.

  3. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Emerson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: camargo@ufscar.br; Barrado, Cristiano M. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil); Ribeiro, Caue [EMBRAPA Instrumentacao Agropecuaria, Rua XV de Novembro 1452, Sao Carlos SP 13560-970 (Brazil)], E-mail: caue@cnpdia.embrapa.br; Longo, Elson [Department of Biochemistry, Chemistry Institute of Araraquara, UNESP-Sao Paulo State University, Rua Francisco Degni, CP 355, Araraquara SP 14801-907 (Brazil)], E-mail: elson@iq.unesp.br; Leite, Edson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: derl@power.ufscar.br

    2009-05-05

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm{sup -1} and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  4. Synthesis and characterization of lead zirconate titanate powders obtained by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Camargo, Emerson R.; Leite, Edson R.; Longo, Elson

    2009-01-01

    Lead zirconate titanate (PbZr 1-x Ti x O 3 ) was synthesized by the 'oxidant peroxo method (OPM)' with 'x' between 0.25 and 0.50. Titanium metal was dissolved into a hydrogen peroxide/ammonia aqueous solution, followed by the addition of lead and zirconium nitrate solution. The amorphous precipitated precursor obtained was crystallized by heat treatment between 400 and 1000 deg. C. Images of transmission microscopy showed spherical particles with average diameter between 20 and 60 nm, and the presence of necks between particles treated at 700 deg. C. All of the unpressed powders were characterized by X-ray diffractometry and FT-Raman spectroscopy. Powder samples with 'x' up to 0.35 showed rhombohedral structure when treated at temperatures higher than 500 deg. C, and tetragonal structure when 'x' was higher than 0.40. Analysis of XRD and Raman spectroscopy of the precursor powders showed amorphous-like structures, however powders treated at 400 deg. C showed a structure identified as an intermediate pyrochlore phase, independently of the Zr and Ti mole ratio

  5. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Camargo, Emerson R.; Barrado, Cristiano M.; Ribeiro, Caue; Longo, Elson; Leite, Edson R.

    2009-01-01

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm -1 and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  6. Analysis of Traffic Accidents Leading to Death Using Tripod Beta Method in Yazd, Iran

    Directory of Open Access Journals (Sweden)

    Mehrzad Ebrahemzadih

    2016-06-01

    Full Text Available This study tried to find the original causes of road accidents to prevent their occurrence. This was a descriptive-analytic retrospective study which assessed 1,000 cases of road accidents leading to death during 2003-2013 using the Tripod Beta method. The latent problems, the contributing preconditions, and corrective strategies for the prevention of occurrence of these accidents were determined. The findings of this study revealed that violation of traffic safety rules, especially deliberate violations and risk-takings decreased with increasing age. In comparative status of the superficial problems, illegal and impermissible speed of drivers accounted for 19.10%, in comparative status of preconditions, violation of safety rules accounted for 32.6% and finally, in comparative status of the latent problems, the presence of financial constraints and time pressure in designing and manufacturing of the cars, and quality of city streets, roads, accounted for 20.1%, of the leading causes of occurrence of accidents in this study.

  7. Evaluation method of lead measurement accuracy of gears using a wedge artefact

    International Nuclear Information System (INIS)

    Komori, Masaharu; Takeoka, Fumi; Kubo, Aizoh; Okamoto, Kazuhiko; Osawa, Sonko; Sato, Osamu; Takatsuji, Toshiyuki

    2009-01-01

    The reduction of the vibration and noise of gears is an important issue in mechanical devices such as vehicles and wind turbines. The characteristics of the vibration and noise of gears are markedly affected by deviations of the tooth flank form of micrometre order; therefore, a strict quality control of the tooth flank form is required. The accuracy of the lead measurement for a gear-measuring instrument is usually evaluated using a master gear or a lead master. However, it is difficult to manufacture masters with high accuracy because the helix is a complicated geometrical form. In this paper, we propose a method of evaluating a gear-measuring instrument using a wedge artefact, which includes a highly precise plane surface. The concept of the wedge artefact is described and a mathematical model of the measuring condition of the wedge artefact is constructed. Theoretical measurement results for the wedge artefact are calculated. The wedge artefact is designed and produced on the basis of the theoretical measurement results. A measurement experiment using the wedge artefact is carried out and its effectiveness is verified

  8. Temporal dynamics of airborne lead-210 in Missouri (USA): implications for geochronological methods

    International Nuclear Information System (INIS)

    Sheets, R.W.; Lawrence, A.E.

    1999-01-01

    Lead-210 ( 210 Pb) deposited from the atmosphere is used in the dating of certain geological materials such as glacial ice and lacustrine sediments, but its long-term atmospheric behavior has been little studied. The present investigation reports measurements of airborne 210 Pb at 21 monitoring stations in Springfield, Missouri, during 1975-1995. Seasonal and diurnal patterns of atmospheric concentrations are established, and the mean annual concentrations of 210 Pb in ground level air during the 20-year period are examined. Although airborne 210 Pb concentrations are found to vary diurnally and seasonally, mean annual concentrations in southwest Missouri have remained relatively constant during this time period. This finding is important for geochronological methods that assume a constant 210 Pb flux from the atmosphere. (orig.)

  9. A on-line method for the determination of lead and lead isotope ratios in fresh and saline waters by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Halicz, Ludwik; Lam, J.W.H.; McLaren, J.W.

    1994-01-01

    A previously reported on-line ICP-MS method for the determination of lead and other trace elements in seawater has been re-examined to determine its suitability for the determination of lead isotope ratios ( 206 Pb/ 207 Pb and 207 Pb/ 208 Pb) in fresh and saline natural waters. A detection limit of 0.9 ng/1 for total lead (for a 5 ml sample) was achieved. Precision of isotope ratio data was 0.2-0.3% RSD at a Pb concentration of 1 μg/l, and was still better than 2% at concentrations of only 10-40 ng/1 in seawater certified reference materials (CRMs). For all three natural water CRMs examined, measured precision was very close to the limit predicted by counting statistics. (Author)

  10. Study by lead isotope method of a vein : Sobrado of the Boquira mine (Bahia State, Brazil)

    International Nuclear Information System (INIS)

    Cassedanne, J.P.; Duthou, J.-L.; Clermont-Ferrand Univ., 63

    1981-01-01

    Fourteen samples of galena from the Sobrado vein, Boquira mine (Bahia) are analysed. Lead isotope compositions show an irregular variation from the central part to the extremidades. They are the result of a mixture of lead from normal galenas and lead which aparent U/Pb ratio are higher. (ARHC) [pt

  11. A novel surface cleaning method for chemical removal of fouling lead layer from chromium surfaces

    International Nuclear Information System (INIS)

    Gholivand, Kh.; Khosravi, M.; Hosseini, S.G.; Fathollahi, M.

    2010-01-01

    Most products especially metallic surfaces require cleaning treatment to remove surface contaminations that remain after processing or usage. Lead fouling is a general problem which arises from lead fouling on the chromium surfaces of bores and other interior parts of systems which have interaction with metallic lead in high temperatures and pressures. In this study, a novel chemical solution was introduced as a cleaner reagent for removing metallic lead pollution, as a fouling metal, from chromium surfaces. The cleaner aqueous solution contains hydrogen peroxide (H 2 O 2 ) as oxidizing agent of lead layer on the chromium surface and acetic acid (CH 3 COOH) as chelating agent of lead ions. The effect of some experimental parameters such as acetic acid concentration, hydrogen peroxide concentration and temperature of the cleaner solution during the operation on the efficiency of lead cleaning procedure was investigated. The results of scanning electron microscopy (SEM) showed that using this procedure, the lead pollution layer could be completely removed from real chromium surfaces without corrosion of the original surface. Finally, the optimum conditions for the complete and fast removing of lead pollution layer from chromium surfaces were proposed. The experimental results showed that at the optimum condition (acetic acid concentration 28% (V/V), hydrogen peroxide 8% (V/V) and temperature 35 deg. C), only 15-min time is needed for complete removal of 3 g fouling lead from a chromium surface.

  12. Cadmium and lead determination by ICPMS: Method optimization and application in carabao milk samples

    Directory of Open Access Journals (Sweden)

    Riza A. Magbitang

    2012-06-01

    Full Text Available A method utilizing inductively coupled plasma mass spectrometry (ICPMS as the element-selective detector with microwave-assisted nitric acid digestion as the sample pre-treatment technique was developed for the simultaneous determination of cadmium (Cd and lead (Pb in milk samples. The estimated detection limits were 0.09ìg kg-1 and 0.33ìg kg-1 for Cd and Pb, respectively. The method was linear in the concentration range 0.01 to 500ìg kg-1with correlation coefficients of 0.999 for both analytes.The method was validated using certified reference material BCR 150 and the determined values for Cd and Pb were 18.24 ± 0.18 ìg kg-1 and 807.57 ± 7.07ìg kg-1, respectively. Further validation using another certified reference material, NIST 1643e, resulted in determined concentrations of 6.48 ± 0.10 ìg L-1 for Cd and 21.96 ± 0.87 ìg L-1 for Pb. These determined values agree well with the certified values in the reference materials.The method was applied to processed and raw carabao milk samples collected in Nueva Ecija, Philippines.The Cd levels determined in the samples were in the range 0.11 ± 0.07 to 5.17 ± 0.13 ìg kg-1 for the processed milk samples, and 0.11 ± 0.07 to 0.45 ± 0.09 ìg kg-1 for the raw milk samples. The concentrations of Pb were in the range 0.49 ± 0.21 to 5.82 ± 0.17 ìg kg-1 for the processed milk samples, and 0.72 ± 0.18 to 6.79 ± 0.20 ìg kg-1 for the raw milk samples.

  13. Wafer scale lead zirconate titanate film preparation by sol-gel method using stress balance layer

    International Nuclear Information System (INIS)

    Lu Jian; Kobayashi, Takeshi; Yi Zhang; Maeda, Ryutaro; Mihara, Takashi

    2006-01-01

    In this paper, platinum/titanium (Pt/Ti) film was introduced as a residual stress balance layer into wafer scale thick lead zirconate titanate (PZT) film fabrication by sol-gel method. The stress developing in PZT film's bottom electrode as well as in PZT film itself during deposition were analyzed; the wafer curvatures, PZT crystallizations and PZT electric properties before and after using Pt/Ti stress balance layer were studied and compared. It was found that this layer is effective to balance the residual stress in PZT film's bottom electrode induced by thermal expansion coefficient mismatch and Ti diffusion, thus can notably reduce the curvature of 4-in. wafer from - 40.5 μm to - 12.9 μm after PZT film deposition. This stress balance layer was also found effective to avoid the PZT film cracking even when annealed by rapid thermal annealing with heating-rate up to 10.5 deg. C/s. According to X-ray diffraction analysis and electric properties characterization, crack-free uniform 1-μm-thick PZT film with preferred pervoskite (001) orientation, excellent dielectric constant, as high as 1310, and excellent remanent polarization, as high as 39.8 μC/cm 2 , can be obtained on 4-in. wafer

  14. New method for cardiac resynchronization therapy: Transapical endocardial lead implantation for left ventricular free wall pacing

    NARCIS (Netherlands)

    I. Kassai (Imre); C. Foldesi (Csaba); A. Szekely (Andrea); T. Szili-Torok (Tamas)

    2008-01-01

    textabstractCoronary sinus lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a significant failure rate at implant and a significant dislocation rate during follow-up. For these patients, epicardial pacing lead implantation is the most

  15. Three-stage method for interpretation of uranium-lead isotopic data

    International Nuclear Information System (INIS)

    Nejmark, L.A.; Ovchinnikova, G.V.; Levchenkov, O.A.

    1982-01-01

    Three-dimensional approach for the iterpretation of uranium-lead isoto e ratios in pnatural systems, development of which corresponds to three stages, has been considered. In the framework of the three-stage model two cases, differing in the character of uranium-lead systems violation at the beginning of the third stage, are discussed. The first case corresponds to uranium addition or lead substraction, and the second one - to addition of lead of unknown isotopic content. Three-stage approach permits without amending the isotopic content of lead captured during crystallization to calculated the beginning of the second and third stages of uranium-lead systems development and to evaluate parameters of lead added to the system. Concrete examples of interpretation of uranium-lead isotopic ratios in minerals and rock samples as a whole both of the terrestrial and cosmic origin are considered. Possibilities and limitations of the three-stage approach are analyzed and directions of further development are outlined

  16. Method to reduce contamination and uptake of lead by plants from car exhaust gases

    Energy Technology Data Exchange (ETDEWEB)

    Isermann, K.

    1977-03-01

    Splashing and/or washing plants with aqueous solutions of the chelates CaEDTA (max. 5 mM/litre) or Na-polyphosphate (max. 0.5 percent) is an effective way of reducing contamination and uptake of lead by plants within regions where lead is emitted at significant levels. By chelating lead it first becomes unloaded or even negatively charged (for instance with EDTA as Pb/sub 2/EDTA or PbHEDTA/sup 1 -/ and PbEDTA/sup 2 -/). Therefore chelated lead, in contrast to normal Pb/sup 2 +/, is not absorbed, either on negatively charged surfaces of the plants (cuticula) or within the plant-tissue (mesophyll, on negatively charged cell-walls or membranes). Also, Pb-chelate has a larger diameter than bivalent Pb/sup 2 +/, resulting in a restricted lead uptake by the plant roots.

  17. The measurement and estimation method of the sorption of lead onto cementitious materials

    International Nuclear Information System (INIS)

    Nakanishi, Kiyoshi; Tsukamoto, Masaki; Fujita, Tomonari; Sugiyama, Daisuke

    2002-01-01

    Cementitious material is a potential waste packaging material for radioactive waste disposal, and is expected to provide chemical containment. In particular, the sorption of radionuclides onto cementitious material is a very important parameter when considering the release of radionuclides from radioactive waste. In this study, sorption of lead, onto hydrated Ordinary Portland Cement (OPC), OPC/Blast Furnace Slag blended cement (BFS), Highly containing Flyash and Silica Fume Cement (HFSC) and cement constituent minerals (portlandite, ettringite, hydrotalcite and C-S-H gels (Ca/Si = 0.9 and 1.65)) was measured using the batch sorption technique. Lead is one of the important nuclides for safety assessment. The obtained distribution ratios, Rd values, for sorption of lead onto hydrated (freshly cured) OPC and HFSC are very high:>1000 cm3g-1. The distribution ratio for sorption of lead onto OPC/BFS could not be determined quantitatively due to the precipitation of PbS. Comparing the Rd values onto cements and minerals, it was suggested the sorption onto C-S-H gel phases dominate the sorption for lead onto hydrated cements. Once a cementitious material is altered in the disposal environment, its sorption ability may be affected. The sorption of lead onto degraded OPC and degraded HFSC, which were altered in the presence of distilled water, was also measured. It was observed that the alteration did not cause changes that decreased the sorption of lead onto OPC and HFSC. An approach, in which it is assumed that each of the component phases contributes to the composite material, is proposed and discussed to describe the sorption of lead onto cement using a knowledge of the phase components in a linear additive manner. The results showed reasonably good agreement between the predicted and measured Rd values for lead onto freshly cured and altered cements. (author)

  18. Superior Reproducibility of the Leading to Leading Edge and Inner to Inner Edge Methods in the Ultrasound Assessment of Maximum Abdominal Aortic Diameter.

    Science.gov (United States)

    Borgbjerg, Jens; Bøgsted, Martin; Lindholt, Jes S; Behr-Rasmussen, Carsten; Hørlyck, Arne; Frøkjær, Jens B

    2018-02-01

    Controversy exists regarding optimal caliper placement in ultrasound assessment of maximum abdominal aortic diameter. This study aimed primarily to determine reproducibility of caliper placement in relation to the aortic wall with the three principal methods: leading to leading edge (LTL), inner to inner edge (ITI), and outer to outer edge (OTO). The secondary aim was to assess the mean difference between the OTO, ITI, and LTL diameters and estimate the impact of using either of these methods on abdominal aortic aneurysm (AAA) prevalence in a screening program. Radiologists (n=18) assessed the maximum antero-posterior abdominal aortic diameter by completing repeated caliper placements with the OTO, LTL, and ITI methods on 50 still abdominal aortic images obtained from an AAA screening program. Inter-observer reproducibility was calculated as the limit of agreement with the mean (LoA), which represents expected deviation of a single observer from the mean of all observers. Intra-observer reproducibility was assessed averaging the LoA for each observer with their repeated measurements. Based on data from an AAA screening trial and the estimated mean differences between the three principal methods, AAA prevalence was estimated using each of the methods. The inter-observer LoA of the OTO, ITI, and LTL was 2.6, 1.9, and 1.9 mm, whereas the intra-observer LoA was 2.0, 1.6, and 1.5 mm, respectively. Mean differences of 5.0 mm were found between OTO and ITI measurements, 2.6 mm between OTO and LTL measurements, and 2.4 mm between LTL and ITI measurements. The prevalence of AAA almost doubled using OTO instead of ITI, while the difference between ITI and LTL was minor (3.3% vs. 4.0% AAA). The study shows superior reproducibility of LTL and ITI compared with the OTO method of caliper placement in ultrasound determination of maximum abdominal aortic diameter, and the choice of caliper placement method significantly affects the prevalence of AAAs in screening programs

  19. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    PREVETTE, S.S.

    2005-01-01

    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

  20. An Alternative Method for Remediating Lead-Contaminated Soils in Residential Areas: A Decision Case Study

    Science.gov (United States)

    Pierzynski, Gary M.; Gehl, Katharine A.

    2004-01-01

    Lead (Pb) is one of the most significant environmental contaminants worldwide and has significant human health effects. Historic use of Pb in paint and gasoline, in particular, have made this contaminant ubiquitous in our environment although widespread use of Pb has declined in the USA. Unfortunately, segments of the population are still…

  1. Method of analysis for the determination of lead and cadmium in fresh meat

    NARCIS (Netherlands)

    Ruig, de W.G.

    1980-01-01

    This report comprises the result of the RIKILT of an intercomparison on the determination of lead and cadmium in bovine liver and bovine kidney. The aim of this round robbin was to check a wet ashing procedure followed by a flame AAS determination as described too in EEC doc. 2266/VI/77. Special

  2. The effect of different propolis harvest methods on its lead contents determined by ET AAS and UV-visS

    Energy Technology Data Exchange (ETDEWEB)

    Sales, A. [Department of Analytical Chemistry, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Ayacucho 471, 4000 Tucuman (Argentina)]. E-mail: amsales@fbqf.unt.edu.ar; Alvarez, A. [National Institute of Agricultural Technology (INTA), Experimental Station Famailla, Ruta 301, Km 32, Famailla, Tucuman (Argentina); Areal, M. Rodriguez [Department of Analytical Chemistry, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Ayacucho 471, 4000 Tucuman (Argentina); Maldonado, L. [National Institute of Agricultural Technology (INTA), Experimental Station Famailla, Ruta 301, Km 32, Famailla, Tucuman (Argentina); Marchisio, P. [Department of Analytical Chemistry, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Ayacucho 471, 4000 Tucuman (Argentina); Rodriguez, M. [Department of Analytical Chemistry, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Ayacucho 471, 4000 Tucuman (Argentina); Bedascarrasbure, E. [National Institute of Agricultural Technology (INTA), Experimental Station Famailla, Ruta 301, Km 32, Famailla, Tucuman (Argentina)

    2006-10-11

    Argentinean propolis is exported to different countries, specially Japan. The market demands propolis quality control according to international standards. The analytical determination of some metals, as lead in food, is very important for their high toxicity even in low concentrations and because of their harmful effects on health. Flavonoids, the main bioactive compounds of propolis, tend to chelate metals as lead, which becomes one of the main polluting agents of propolis. The lead found in propolis may come from the atmosphere or it may be incorporated in the harvest, extraction and processing methods. The aim of this work is to evaluate lead level on Argentinean propolis determined by electrothermal atomic absorption spectrometry (ET AAS) and UV-vis spectrophotometry (UV-visS) methods, as well as the effect of harvest methods on those contents. A randomized test with three different treatments of collection was made to evaluate the effect of harvest methods. These procedures were: separating wedges (traditional), netting plastic meshes and stamping out plastic meshes. By means of the analysis of variance technique for multiple comparisons (ANOVA) it was possible to conclude that there are significant differences between scraped and mesh methods (stamped out and mosquito netting meshes). The results obtained in the present test would allow us to conclude that mesh methods are more advisable than scraped ones in order to obtain innocuous and safe propolis with minor lead contents. A statistical comparison of lead determination by both, ET AAS and UV-visS methods, demonstrated that there is not a significant difference in the results achieved with the two analytical techniques employed.

  3. Extending the Matrix Element Method beyond the Born approximation: calculating event weights at next-to-leading order accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Till; Uwer, Peter [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstraße 15, 12489 Berlin (Germany)

    2015-09-14

    In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e{sup +}e{sup −} annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.

  4. Extending the Matrix Element Method beyond the Born approximation: calculating event weights at next-to-leading order accuracy

    International Nuclear Information System (INIS)

    Martini, Till; Uwer, Peter

    2015-01-01

    In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e"+e"− annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.

  5. Sensitivity analyses by Generalized Perturbation Theory (GPT) methods applied to GUINEVERE and MYRRHA lead fast reactors

    International Nuclear Information System (INIS)

    Carta, M.; Bianchini, G.; Peluso, V.; Gandini, A.; Fabrizio, V.; Ricci, L.

    2013-01-01

    Conclusions: • GPT methodologies can provide a codified “key to reading” to the properties of some GUINEVERE integral characteristics respect to analogous characteristics in MYRRHA. • The present work has been focused on the analysis, by numerical simulations, of the representativeness, with respect to the MYRRHA situation assumed as reference system, of the behaviour in GUINEVERE of the spectral indexes F9/F5, F8/F5 and F7/F5 following a localized (core shell) or global (whole active core) lead (GUINEVERE) or lead-bismuth (MYRRHA) 20% density reduction. • The analysis, carried out by means of GPT methodologies implemented into the ERANOS French neutronic code, and using the US dispersion matrix BOLNA, provided encouraging results concerning the correlation for all the spectral indexes taken into account

  6. The lead cooled fast reactor benchmark Brest-300: analysis with sensitivity method

    International Nuclear Information System (INIS)

    Smirnov, V.; Orlov, V.; Mourogov, A.; Lecarpentier, D.; Ivanova, T.

    2005-01-01

    Lead cooled fast neutrons reactor is one of the most interesting candidates for the development of atomic energy. BREST-300 is a 300 MWe lead cooled fast reactor developed by the NIKIET (Russia) with a deterministic safety approach which aims to exclude reactivity margins greater than the delayed neutron fraction. The development of innovative reactors (lead coolant, nitride fuel...) and fuel cycles with new constraints such as cycle closure or actinide burning, requires new technologies and new nuclear data. In this connection, the tool and neutron data used for the calculational analysis of reactor characteristics requires thorough validation. NIKIET developed a reactor benchmark fitting of design type calculational tools (including neutron data). In the frame of technical exchanges between NIKIET and EDF (France), results of this benchmark calculation concerning the principal parameters of fuel evolution and safety parameters has been inter-compared, in order to estimate the uncertainties and validate the codes for calculations of this new kind of reactors. Different codes and cross-sections data have been used, and sensitivity studies have been performed to understand and quantify the uncertainties sources.The comparison of results shows that the difference on k eff value between ERANOS code with ERALIB1 library and the reference is of the same order of magnitude than the delayed neutron fraction. On the other hand, the discrepancy is more than twice bigger if JEF2.2 library is used with ERANOS. Analysis of discrepancies in calculation results reveals that the main effect is provided by the difference of nuclear data, namely U 238 , Pu 239 fission and capture cross sections and lead inelastic cross sections

  7. Apparatus and methods for monitoring the concentrations of hazardous airborne substances, especially lead

    Science.gov (United States)

    Zaromb, Solomon

    2004-07-13

    Air is sampled at a rate in excess of 100 L/min, preferably at 200-300 L/min, so as to collect therefrom a substantial fraction, i.e., at least 20%, preferably 60-100%, of airborne particulates. A substance of interest (analyte), such as lead, is rapidly solubilized from the the collected particulates into a sample of liquid extractant, and the concentration of the analyte in the extractant sample is determined. The high-rate air sampling and particulate collection may be effected with a high-throughput filter cartridge or with a recently developed portable high-throughput liquid-absorption air sampler. Rapid solubilization of lead is achieved by a liquid extractant comprising 0.1-1 M of acetic acid or acetate, preferably at a pH of 5 or less and preferably with inclusion of 1-10% of hydrogen peroxide. Rapid determination of the lead content in the liquid extractant may be effected with a colorimetric or an electroanalytical analyzer.

  8. Virtual reality lead extraction as a method for training new physicians: a pilot study.

    Science.gov (United States)

    Maytin, Melanie; Daily, Thomas P; Carillo, Roger G

    2015-03-01

    It is estimated that the demand for transvenous lead extraction (TLE) has reached an annual extraction rate of nearly 24,000 patients worldwide. Despite technologic advances, TLE still has the potential for significant morbidity and mortality. Complication rates with TLE directly parallel operator experience. However, obtaining adequate training during and postfellowship can be difficult. Given the potential for catastrophic complications and the steep learning curve (up to 300 cases) associated with this procedure, we sought to validate a virtual reality (VR) lead extraction simulator as an innovative training and evaluation tool for physicians new to TLE. We randomized eight electrophysiology fellows to VR simulator versus conventional training. We compared procedural skill competency between the groups using simulator competency, tactile measurements, markers of proficiency and attitudes, and cognitive abilities battery. Practical skills and simulator complications differed significantly between the VR simulator and conventional training groups. The VR simulator group executed patient preparation and procedure performance better than the conventional group (P training experienced a simulator complication (two superior vena cava [SVC] tears, three right ventricle [RV] avulsions) versus one fellow in the VR simulator group (one SVC tear) (P = 0.02). Tactile measurements revealed a trend toward excess pushing versus pulling forces among the conventionally trained group. The time for lead removal was also significantly higher in the conventional training group (12.46 minutes vs 5.54 minutes, P = 0.02). There was no significant difference in baseline or posttraining cognitive ability. We contend that the implementation of alternative training tools such as a VR simulation model will improve physician training and allow for an innovative pathway to assess the achievement of competency. ©2014 Wiley Periodicals, Inc.

  9. Trends in study design and the statistical methods employed in a leading general medicine journal.

    Science.gov (United States)

    Gosho, M; Sato, Y; Nagashima, K; Takahashi, S

    2018-02-01

    Study design and statistical methods have become core components of medical research, and the methodology has become more multifaceted and complicated over time. The study of the comprehensive details and current trends of study design and statistical methods is required to support the future implementation of well-planned clinical studies providing information about evidence-based medicine. Our purpose was to illustrate study design and statistical methods employed in recent medical literature. This was an extension study of Sato et al. (N Engl J Med 2017; 376: 1086-1087), which reviewed 238 articles published in 2015 in the New England Journal of Medicine (NEJM) and briefly summarized the statistical methods employed in NEJM. Using the same database, we performed a new investigation of the detailed trends in study design and individual statistical methods that were not reported in the Sato study. Due to the CONSORT statement, prespecification and justification of sample size are obligatory in planning intervention studies. Although standard survival methods (eg Kaplan-Meier estimator and Cox regression model) were most frequently applied, the Gray test and Fine-Gray proportional hazard model for considering competing risks were sometimes used for a more valid statistical inference. With respect to handling missing data, model-based methods, which are valid for missing-at-random data, were more frequently used than single imputation methods. These methods are not recommended as a primary analysis, but they have been applied in many clinical trials. Group sequential design with interim analyses was one of the standard designs, and novel design, such as adaptive dose selection and sample size re-estimation, was sometimes employed in NEJM. Model-based approaches for handling missing data should replace single imputation methods for primary analysis in the light of the information found in some publications. Use of adaptive design with interim analyses is increasing

  10. A fast method for the determination of lead in honey samples using stabilizer-free silver nanoparticles

    Science.gov (United States)

    Bittar, Dayana Borges; Catelani, Tiago Augusto; Pezza, Leonardo; Pezza, Helena Redigolo

    2018-01-01

    A sensitive, rapid and robust method based on the use of stabilizer-free silver nanoparticles was developed for lead detection in honey. Silver nanoparticles were synthesized without the presence of any stabilizers using silver nitrate and sodium borohydride as precursors where the latter was applied as reducing agent. The optimization of the experimental variables (AgNO3 and NaBH4) for the formation of the nanoparticles was carried out using varying volumes of these solutions. Spectrophotometric measurements at 393 nm showed a linear working range between 0.0500 and 0.167 mg L- 1 lead (R = 0.994), with limits of detection (LOD) and quantification (LOQ) of 0.0135 and 0.0451 mg L- 1, respectively. The proposed method proved to be a significantly sensitive mechanism for lead detection in honey samples.

  11. Development and validation of a novel, simple, and accurate spectrophotometric method for the determination of lead in human serum.

    Science.gov (United States)

    Shayesteh, Tavakol Heidari; Khajavi, Farzad; Khosroshahi, Abolfazl Ghafuri; Mahjub, Reza

    2016-01-01

    The determination of blood lead levels is the most useful indicator of the determination of the amount of lead that is absorbed by the human body. Various methods, like atomic absorption spectroscopy (AAS), have already been used for the detection of lead in biological fluid, but most of these methods are based on complicated, expensive, and highly instructed instruments. In this study, a simple and accurate spectroscopic method for the determination of lead has been developed and applied for the investigation of lead concentration in biological samples. In this study, a silica gel column was used to extract lead and eliminate interfering agents in human serum samples. The column was washed with deionized water. The pH was adjusted to the value of 8.2 using phosphate buffer, and then tartrate and cyanide solutions were added as masking agents. The lead content was extracted into the organic phase containing dithizone as a complexion reagent and the dithizone-Pb(II) complex was formed and approved by visible spectrophotometry at 538 nm. The recovery was found to be 84.6 %. In order to validate the method, a calibration curve involving the use of various concentration levels was calculated and proven to be linear in the range of 0.01-1.5 μg/ml, with an R (2) regression coefficient of 0.9968 by statistical analysis of linear model validation. The largest error % values were found to be -5.80 and +11.6 % for intra-day and inter-day measurements, respectively. The largest RSD % values were calculated to be 6.54 and 12.32 % for intra-day and inter-day measurements, respectively. Further, the limit of detection (LOD) was calculated to be 0.002 μg/ml. The developed method was applied to determine the lead content in the human serum of voluntary miners, and it has been proven that there is no statistically significant difference between the data provided from this novel method and the data obtained from previously studied AAS.

  12. 40 CFR Appendix G to Part 50 - Reference Method for the Determination of Lead in Suspended Particulate Matter Collected From...

    Science.gov (United States)

    2010-07-01

    ... minimize the possibility of generating unreliable data, the user should follow practices established for... chapter—Modifications of methods by users. (Guidance or assistance in requesting approval under Section 2... lead content of the sample is analyzed by atomic absorption spectrometry using an air-acetylene flame...

  13. Research on output signal of piezoelectric lead zirconate titanate detector using Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Takechi, Seiji, E-mail: takechi@elec.eng.osaka-cu.ac.jp [Graduate School of Engineering, Osaka City University, Osaka 558-8585 (Japan); Mitsuhashi, Tomoaki; Miura, Yoshinori [Graduate School of Engineering, Osaka City University, Osaka 558-8585 (Japan); Miyachi, Takashi; Kobayashi, Masanori; Okudaira, Osamu [Planetary Exploration Research Center, Chiba Institute of Technology, Narashino, Chiba 275-0016 (Japan); Shibata, Hiromi [The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Fujii, Masayuki [Famscience Co., Ltd., Tsukubamirai, Ibaraki 300-2435 (Japan); Okada, Nagaya [Honda Electronics Co., Ltd., Toyohashi, Aichi 441-3193 (Japan); Murakami, Takeshi; Uchihori, Yukio [National Institute of Radiological Sciences, Chiba 263-8555 (Japan)

    2017-06-21

    The response of a radiation detector fabricated from piezoelectric lead zirconate titanate (PZT) was studied. The response signal due to a single 400 MeV/n xenon (Xe) ion was assumed to have a simple form that was composed of two variables, the amplitude and time constant. These variables were estimated by comparing two output waveforms obtained from a computer simulation and an experiment on Xe beam irradiation. Their values appeared to be dependent on the beam intensity. - Highlights: • The performance of PZT detector was studied by irradiation of a 400 MeV/n Xe beam. • Monte Carlo simulation was used to examine the formation process of the output. • The response signal due to a single Xe ion was assumed to have a simple form. • The form was composed of two variables, the amplitude and time constant. • These variables appeared to be dependent on the beam intensity.

  14. Comparison of four bioindication methods for assessing the degree of environmental lead and cadmium pollution

    Energy Technology Data Exchange (ETDEWEB)

    Dmuchowski, Wojciech, E-mail: w.dmuchowski@obpan.pl [Botanical Garden-Center for Conservation of Biological Diversity, Polish Academy of Science, Prawdziwka 2, 02-973 Warsaw (Poland); Warsaw University of Life Sciences-SGGW, Faculty of Agriculture and Biology, 159 Nowoursynowska 159, 02-776 Warsaw (Poland); Gozdowski, Dariusz, E-mail: dariusz_gozdowski@sggw.pl [Warsaw University of Life Sciences-SGGW, Faculty of Agriculture and Biology, 159 Nowoursynowska 159, 02-776 Warsaw (Poland); Baczewska, Aneta Helena [Botanical Garden-Center for Conservation of Biological Diversity, Polish Academy of Science, Prawdziwka 2, 02-973 Warsaw (Poland)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer In this study we examined level of contamination in extremely heavy polluted area. Black-Right-Pointing-Pointer We examined four various bioindication methods. Black-Right-Pointing-Pointer Results were presented in pollution maps. Black-Right-Pointing-Pointer We evaluated relationships between examined bioindication methods. - Abstract: The purpose of this study was to assess the application of several bioindication methods for the monitoring of environmental pollution from Pb and Cd. The study area centered on the town of Olkusz, Poland, which is one of the oldest centers for the metallurgical industry in Europe. The assessment of environmental pollution due to metals was performed using four frequently used bioindication methods: moss-bag (Sphagnum fallax), determination of metal accumulation in Pleurozium schreberi, silver birch foliage, and Scots pine needles. The region of Olkusz, and especially the area surrounding the mining and metallurgical Boleslaw complex, was extremely contaminated with Pb and Cd. The results of the investigations are presented as contamination deposition maps. Despite the application of various methods and the resulting diversity of the specific exposure periods for different biomonitors, the spatial distribution of contamination shown on the maps was similar, as confirmed by the statistical analysis of the results.

  15. Comparison of four bioindication methods for assessing the degree of environmental lead and cadmium pollution

    International Nuclear Information System (INIS)

    Dmuchowski, Wojciech; Gozdowski, Dariusz; Baczewska, Aneta Helena

    2011-01-01

    Highlights: ► In this study we examined level of contamination in extremely heavy polluted area. ► We examined four various bioindication methods. ► Results were presented in pollution maps. ► We evaluated relationships between examined bioindication methods. - Abstract: The purpose of this study was to assess the application of several bioindication methods for the monitoring of environmental pollution from Pb and Cd. The study area centered on the town of Olkusz, Poland, which is one of the oldest centers for the metallurgical industry in Europe. The assessment of environmental pollution due to metals was performed using four frequently used bioindication methods: moss-bag (Sphagnum fallax), determination of metal accumulation in Pleurozium schreberi, silver birch foliage, and Scots pine needles. The region of Olkusz, and especially the area surrounding the mining and metallurgical Bolesław complex, was extremely contaminated with Pb and Cd. The results of the investigations are presented as contamination deposition maps. Despite the application of various methods and the resulting diversity of the specific exposure periods for different biomonitors, the spatial distribution of contamination shown on the maps was similar, as confirmed by the statistical analysis of the results.

  16. Preparation of lead oxide nanoparticles from cathode-ray tube funnel glass by self-propagating method.

    Science.gov (United States)

    Wang, Yu; Zhu, Jianxin

    2012-05-15

    This paper presents a novel process of extracting lead oxide nanoparticles from cathode-ray tube (CRT) funnel glass using self-propagating high-temperature synthesis (SHS) method. The impacts of added amount of funnel glass on the extraction ratio of lead, the lead extraction velocity and the micromorphology, as well as particle size of extracted nanoparticles were investigated. We found that self-propagating reaction in the presence of Mg and Fe(2)O(3) could separate lead preferentially and superfine lead oxide nanoparticles were obtained from a collecting chamber. The separation ratio was related closely to the amount of funnel glass added in the original mixture. At funnel glass addition of no more than 40wt.%, over 90wt.% of lead was recovered from funnel glass. High extraction yield reveals that the network structure of funnel glass was fractured due to the dramatic energy generated during the SHS melting process. The PbO nanoparticles collected show good dispersion and morphology with a mean grain size of 40-50nm. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Flipping the Graduate Qualitative Research Methods Classroom: Did It Lead to Flipped Learning?

    Science.gov (United States)

    Earley, Mark

    2016-01-01

    The flipped, or inverted, classroom has gained popularity in a variety of fields and at a variety of educational levels, from K-12 through higher education. This paper describes the author's positive experience flipping a graduate qualitative research methods classroom. After a review of the current literature on flipped classrooms in higher…

  18. Phosphorus Amendment Efficacy for In Situ Remediation of Soil Lead Depends on the Bioaccessible Method

    Science.gov (United States)

    A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccesible Pb in P-treated soils. Two Pb-contaminated soils...

  19. Determination of Trace Amounts of Lead with ETAAS After Single Drop Microextraction and Dispersive Liquid Liquid Microextraction Methods

    Directory of Open Access Journals (Sweden)

    Efeçınar M.

    2013-04-01

    Full Text Available Two liquid-phase microextraction procedures, single-drop microextraction (SDME and dispersive liquid–liquid microextraction (DLLME, have been developed for the determination of lead by electrothermal atomic absorption spectrometry (ETAAS. Both methods were based on the formation of lead iodide-Rhodamine B complex which is in phosphoric acid medium. In the presence of KI, anionic lead iodide was complexed with Rhodamine B as an ion-association complex. Several factors that may be affected on the SDME and DLLME methods were optimized. In the optimum experimental conditions, the limit of detection (3s and the enhancement factor were 0.008 μgL−1 and 152 for SDME and 0.0129 μgL−1 and 89 for DLLME respectively. The relative standard deviation (RSD for eight replicate determinations of 0.25 μgL−1 Pb was 4.6% for SDME and 0.5 μgL−1 Pb was 2.9% for DLLME. The developed methods were validated by the analysis of certified reference materials, and applied successfully to the determination of lead in several water and food samples.

  20. A simple method to identify radiation and annealing biases that lead to worst-case CMOS static RAM postirradiation response

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Dressendorfer, P.V.

    1987-01-01

    The authors illustrate a simple method to identify bias conditions that lead to worst-case postirradiation speed and timing response for SRAMs. Switching cell states between radiation and anneal should lead to maximum speed and timing degradation for many hardened designs and technologies. The greatest SRAM cell imbalance is also established by these radiation and annealing conditions for the hardened and commercial parts that we have examined. These results should provide insight into the behavior of SRAMs during and after irradiation. The results should also be useful to establishing guidelines for integrated-circuit functionality testing, and SEU and dose-rate upset testing, after total-dose irradiation

  1. Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

    Science.gov (United States)

    Daso, Endwell O. (Inventor); Pritchett, Victor E., II (Inventor); Wang, Ten-See (Inventor); Farr, Rebecca Ann (Inventor); Auslender, Aaron Howard (Inventor); Blankson, Isaiah M. (Inventor); Plotkin, Kenneth J. (Inventor)

    2015-01-01

    A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated.

  2. An Approximate Redistributed Proximal Bundle Method with Inexact Data for Minimizing Nonsmooth Nonconvex Functions

    Directory of Open Access Journals (Sweden)

    Jie Shen

    2015-01-01

    Full Text Available We describe an extension of the redistributed technique form classical proximal bundle method to the inexact situation for minimizing nonsmooth nonconvex functions. The cutting-planes model we construct is not the approximation to the whole nonconvex function, but to the local convexification of the approximate objective function, and this kind of local convexification is modified dynamically in order to always yield nonnegative linearization errors. Since we only employ the approximate function values and approximate subgradients, theoretical convergence analysis shows that an approximate stationary point or some double approximate stationary point can be obtained under some mild conditions.

  3. Comparison of four bioindication methods for assessing the degree of environmental lead and cadmium pollution.

    Science.gov (United States)

    Dmuchowski, Wojciech; Gozdowski, Dariusz; Baczewska, Aneta Helena

    2011-12-15

    The purpose of this study was to assess the application of several bioindication methods for the monitoring of environmental pollution from Pb and Cd. The study area centered on the town of Olkusz, Poland, which is one of the oldest centers for the metallurgical industry in Europe. The assessment of environmental pollution due to metals was performed using four frequently used bioindication methods: moss-bag (Sphagnum fallax), determination of metal accumulation in Pleurozium schreberi, silver birch foliage, and Scots pine needles. The region of Olkusz, and especially the area surrounding the mining and metallurgical Bolesław complex, was extremely contaminated with Pb and Cd. The results of the investigations are presented as contamination deposition maps. Despite the application of various methods and the resulting diversity of the specific exposure periods for different biomonitors, the spatial distribution of contamination shown on the maps was similar, as confirmed by the statistical analysis of the results. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Comparison of two methods for blood lead analysis in cattle: graphite-furnace atomic absorption spectrometry and LeadCare(R) II system.

    Science.gov (United States)

    Bischoff, Karyn; Gaskill, Cynthia; Erb, Hollis N; Ebel, Joseph G; Hillebrandt, Joseph

    2010-09-01

    The current study compared the LeadCare(R) II test kit system with graphite-furnace atomic absorption spectrometry for blood lead (Pb) analysis in 56 cattle accidentally exposed to Pb in the field. Blood Pb concentrations were determined by LeadCare II within 4 hr of collection and after 72 hr of refrigeration. Blood Pb concentrations were determined by atomic absorption spectrometry, and samples that were coagulated (n = 12) were homogenized before analysis. There was strong rank correlation (R(2) = 0.96) between atomic absorption and LeadCare II (within 4 hr of collection), and a conversion formula was determined for values within the observed range (3-91 mcg/dl, although few had values >40 mcg/dl). Median and mean blood pb concentrations for atomic absorption were 7.7 and 15.9 mcg/dl, respectively; for LeadCare II, medians were 5.2 mcg/dl at 4 hr and 4.9 mcg/dl at 72 hr, and means were 12.4 and 11.7, respectively. LeadCare II results at 4 hr strongly correlated with 72 hr results (R(2) = 0.96), but results at 72 hr were lower (P atomic absorption. Although there have been several articles that compared LeadCare with other analytical techniques, all were for the original system, not LeadCare II. The present study indicated that LeadCare II results correlated well with atomic absorption over a wide range of blood Pb concentrations and that refrigerating samples for up to 72 hr before LeadCare II analysis was acceptable for clinical purposes.

  5. A method of lines solution of the transient behavior of the helium cooled power leads for the SSC

    International Nuclear Information System (INIS)

    Demko, J.A.; Schiesser, W.E.; Carcagno, R.; McAshan, M.

    1995-01-01

    In this study, a detailed numerical thermal mode of a 6.5 kA power lead for the Superconducting Super Collider has been developed, which was adapted from the dynamic model developed by Schiesser. The transient behavior of the power leads was modeled using, a method of lines (MOL) approach. The model was developed to pmvide a tool for analyzing coolant control strategies as well as an understanding of the behavior of the leads under presumed system transients. Results for a current ramp up to 4970 amps are favorably compared with measurements. Also, a loss of cooling situation is predicted to determine the transient temperature distribution under an off-design condition

  6. Standard test method for graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 g/mL and cadmium concentrations greater than 0.0005 to 0.002 g/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination cont...

  7. Leading for the long haul: a mixed-method evaluation of the Sustainment Leadership Scale (SLS).

    Science.gov (United States)

    Ehrhart, Mark G; Torres, Elisa M; Green, Amy E; Trott, Elise M; Willging, Cathleen E; Moullin, Joanna C; Aarons, Gregory A

    2018-01-19

    Despite our progress in understanding the organizational context for implementation and specifically the role of leadership in implementation, its role in sustainment has received little attention. This paper took a mixed-method approach to examine leadership during the sustainment phase of the Exploration, Preparation, Implementation, Sustainment (EPIS) framework. Utilizing the Implementation Leadership Scale as a foundation, we sought to develop a short, practical measure of sustainment leadership that can be used for both applied and research purposes. Data for this study were collected as a part of a larger mixed-method study of evidence-based intervention, SafeCare®, sustainment. Quantitative data were collected from 157 providers using web-based surveys. Confirmatory factor analysis was used to examine the factor structure of the Sustainment Leadership Scale (SLS). Qualitative data were collected from 95 providers who participated in one of 15 focus groups. A framework approach guided qualitative data analysis. Mixed-method integration was also utilized to examine convergence of quantitative and qualitative findings. Confirmatory factor analysis supported the a priori higher order factor structure of the SLS with subscales indicating a single higher order sustainment leadership factor. The SLS demonstrated excellent internal consistency reliability. Qualitative analyses offered support for the dimensions of sustainment leadership captured by the quantitative measure, in addition to uncovering a fifth possible factor, available leadership. This study found qualitative and quantitative support for the pragmatic SLS measure. The SLS can be used for assessing leadership of first-level leaders to understand how staff perceive leadership during sustainment and to suggest areas where leaders could direct more attention in order to increase the likelihood that EBIs are institutionalized into the normal functioning of the organization.

  8. Production Method that Leads to TiO2 Nanofibrous Structure Usable in Food Packaging

    Directory of Open Access Journals (Sweden)

    Kovář Radovan

    2016-12-01

    Full Text Available Burned inorganic nanofibers most often occur in the nature in two forms: rutile and anatase. Today, the production of rutile is about to end, while anatase provides more application possibilities. The resulting fiber structure is determined by calcination. It is necessary to find the optimal temperature as well as time, during which the fibers must withstand temperature load. For such method of calcination, it is necessary to create a special design of continuous furnace. Anatase has application in food packaging. Packages containing anatase are used for: food safety, improved packaging for spoilage reduction, sensors for detection of pathogens and spoilage, disinfectants and antimicrobial surfaces.

  9. High aspect ratio lead zirconate titanate tube structures: I. Template assisted fabrication - vacuum infiltration method

    Directory of Open Access Journals (Sweden)

    Vladimír Kovaľ

    2012-03-01

    Full Text Available Polycrystalline Pb(Zr0.52Ti0.48O3 (PZT microtubes are fabricated by a vacuum infiltration method. The method is based on repeated infiltration of precursor solution into macroporous silicon (Si templates at a sub-atmospheric pressure. The pyrolyzed PZT tubes of a 2-µm outer diameter, extending to over 30 µm in length were released from the template using a selective isotropic-pulsed XeF2 reactive ion etching of silicon. Free-standing microtubes, partially anchored at the bottom of the Si template, were then crystallized in pure oxygen atmosphere at 750 °C for 2 min using a rapid thermal annealer. The perovskite phase of the final PZT tubes was confirmed by X-ray diffraction (XRD analysis. The XRD spectrum also revealed a small amount of the pyrochlore phase in the structure and signs of possible fluoride contamination caused most likely by the XeF2 etching process. The surface morphology was examined using scanning electron microscopy. It was demonstrated that the whole surface of the pore walls was conformally coated during the repeated infiltration of templates, resulting in straight tubes with closed tips formed on the opposite ends as replicas of the pore bottoms. These high aspect ratio ferroelectric structures are suggested as building units for developing miniaturized electronic devices, such as memory storage (DRAM trenched capacitors, piezoelectric scanners and actuators, and are of fundamental value for the theory of ferroelectricity in systems with low dimensionality.

  10. The lead-lag relationship between stock index and stock index futures: A thermal optimal path method

    Science.gov (United States)

    Gong, Chen-Chen; Ji, Shen-Dan; Su, Li-Ling; Li, Sai-Ping; Ren, Fei

    2016-02-01

    The study of lead-lag relationship between stock index and stock index futures is of great importance for its wide application in hedging and portfolio investments. Previous works mainly use conventional methods like Granger causality test, GARCH model and error correction model, and focus on the causality relation between the index and futures in a certain period. By using a non-parametric approach-thermal optimal path (TOP) method, we study the lead-lag relationship between China Securities Index 300 (CSI 300), Hang Seng Index (HSI), Standard and Poor 500 (S&P 500) Index and their associated futures to reveal the variance of their relationship over time. Our finding shows evidence of pronounced futures leadership for well established index futures, namely HSI and S&P 500 index futures, while index of developing market like CSI 300 has pronounced leadership. We offer an explanation based on the measure of an indicator which quantifies the differences between spot and futures prices for the surge of lead-lag function. Our results provide new perspectives for the understanding of the dynamical evolution of lead-lag relationship between stock index and stock index futures, which is valuable for the study of market efficiency and its applications.

  11. A Study of Applications of Machine Learning Based Classification Methods for Virtual Screening of Lead Molecules.

    Science.gov (United States)

    Vyas, Renu; Bapat, Sanket; Jain, Esha; Tambe, Sanjeev S; Karthikeyan, Muthukumarasamy; Kulkarni, Bhaskar D

    2015-01-01

    The ligand-based virtual screening of combinatorial libraries employs a number of statistical modeling and machine learning methods. A comprehensive analysis of the application of these methods for the diversity oriented virtual screening of biological targets/drug classes is presented here. A number of classification models have been built using three types of inputs namely structure based descriptors, molecular fingerprints and therapeutic category for performing virtual screening. The activity and affinity descriptors of a set of inhibitors of four target classes DHFR, COX, LOX and NMDA have been utilized to train a total of six classifiers viz. Artificial Neural Network (ANN), k nearest neighbor (k-NN), Support Vector Machine (SVM), Naïve Bayes (NB), Decision Tree--(DT) and Random Forest--(RF). Among these classifiers, the ANN was found as the best classifier with an AUC of 0.9 irrespective of the target. New molecular fingerprints based on pharmacophore, toxicophore and chemophore (PTC), were used to build the ANN models for each dataset. A good accuracy of 87.27% was obtained using 296 chemophoric binary fingerprints for the COX-LOX inhibitors compared to pharmacophoric (67.82%) and toxicophoric (70.64%). The methodology was validated on the classical Ames mutagenecity dataset of 4337 molecules. To evaluate it further, selectivity and promiscuity of molecules from five drug classes viz. anti-anginal, anti-convulsant, anti-depressant, anti-arrhythmic and anti-diabetic were studied. The TPC fingerprints computed for each category were able to capture the drug-class specific features using the k-NN classifier. These models can be useful for selecting optimal molecules for drug design.

  12. Determination of temperature dependence of piezoelectric coefficients matrix of lead zirconate titanate ceramics by quasi-static and resonance method

    International Nuclear Information System (INIS)

    Li Fei; Xu Zhuo; Wei Xiaoyong; Yao Xi

    2009-01-01

    The piezoelectric coefficients (d 33 , -d 31 , d 15 , g 33 , -g 31 , g 15 ) of soft and hard lead zirconate titanate ceramics were measured by the quasi-static and resonance methods, at temperatures from 20 to 300 0 C. The results showed that the piezoelectric coefficients d 33 , -d 31 and d 15 obtained by these two methods increased with increasing temperature for both hard and soft PZT ceramics, while the piezoelectric coefficients g 33 , -g 31 and g 15 decreased with increasing temperature for both hard and soft PZT ceramics. In this paper, the observed results were also discussed in terms of intrinsic and extrinsic contributions to piezoelectric response.

  13. A rugged and transferable method for determining blood cadmium, mercury, and lead with inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    McShane, William J.; Pappas, R. Steven; Wilson-McElprang, Veronica; Paschal, Dan

    2008-01-01

    A simple, high-throughput method for determining total cadmium, mercury, and lead in blood in cases of suspected exposure, using inductively coupled plasma-mass spectrometry (ICP-MS), has been developed and validated. One part matrix-matched standards, blanks, or aliquots of blood specimens were diluted with 49 parts of a solution containing 0.25% (w/w) tetramethylammonium hydroxide; 0.05% v/v Triton X-100 (blood cell membranes and protein solubilization); 0.01% (w/v) ammonium pyrolidinedithiocarbamate (mercury memory effect prevention and oxidation state stabilization, solubilization by complexation of all three metals); 1% v/v isopropanol (signal enhancement); and 10 μg/L iridium (internal standard). Thus the final dilution factor is 1 + 49. The method provides the basis for the determination of total cadmium, mercury, and lead for assessment of environmental, occupational, accidental ingestion or elevated exposures from other means. Approximately 80 specimens, including blanks, calibration standards, and quality control materials can be processed in an 8-h day. The method has been evaluated by examining reference materials from the National Institute of Standards and Technology, as well as by participation in six rounds of proficiency testing intercomparisons led by the Wadsworth Center of the New York State Department of Health. This method was developed for the purpose of increasing U.S. emergency response laboratory capacity. To this end, 33 U.S. state, and 1 district health department laboratories have validated this method in their own laboratories

  14. A rugged and transferable method for determining blood cadmium, mercury, and lead with inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McShane, William J. [Battelle-Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants Branch, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: WMcShane@cdc.gov; Pappas, R. Steven [Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: RPappas@cdc.gov; Wilson-McElprang, Veronica [Battelle-Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants Branch, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: VWilsonMcelprang@cdc.gov; Paschal, Dan [Centers for Disease Control and Prevention, Division of Laboratory Sciences, Emergency Response and Air Toxicants, 4770 Buford Highway, MS F-44, Atlanta, GA 30341 (United States)], E-mail: DPaschal@cdc.gov

    2008-06-15

    A simple, high-throughput method for determining total cadmium, mercury, and lead in blood in cases of suspected exposure, using inductively coupled plasma-mass spectrometry (ICP-MS), has been developed and validated. One part matrix-matched standards, blanks, or aliquots of blood specimens were diluted with 49 parts of a solution containing 0.25% (w/w) tetramethylammonium hydroxide; 0.05% v/v Triton X-100 (blood cell membranes and protein solubilization); 0.01% (w/v) ammonium pyrolidinedithiocarbamate (mercury memory effect prevention and oxidation state stabilization, solubilization by complexation of all three metals); 1% v/v isopropanol (signal enhancement); and 10 {mu}g/L iridium (internal standard). Thus the final dilution factor is 1 + 49. The method provides the basis for the determination of total cadmium, mercury, and lead for assessment of environmental, occupational, accidental ingestion or elevated exposures from other means. Approximately 80 specimens, including blanks, calibration standards, and quality control materials can be processed in an 8-h day. The method has been evaluated by examining reference materials from the National Institute of Standards and Technology, as well as by participation in six rounds of proficiency testing intercomparisons led by the Wadsworth Center of the New York State Department of Health. This method was developed for the purpose of increasing U.S. emergency response laboratory capacity. To this end, 33 U.S. state, and 1 district health department laboratories have validated this method in their own laboratories.

  15. Absorption and translocation of lead by plants: a contribution to the application of the method of radioactive indicators in the investigation of the change of substance

    Energy Technology Data Exchange (ETDEWEB)

    Hevesy, G

    1923-01-01

    The assimilation of lead from lead nitrate solutions by Vicia Faba has been investigated. A radioactive isotope of lead was mixed with the lead nitrate, and the amount of lead taken up was determined after ignition from the radioactive intensity of the ash of the various parts. This method makes possible the determination of exceedingly small amounts of assimilated lead. Whereas 0-3% of the lead is taken up by the root from 200 cc. of a 10/sup -1/ N lead nitrate solution in the course of 24 hours, 60% of the lead content of a 10/sup -1/ N lead nitrate solution in the course of 24 hours, 60% of the lead content of a 10/sup -6/ N solution is taken up in the same time. The leaves show a lead content of only a few hundredths or thousandths of 1% of the amount of lead present in the solution. The assimilated (radioactive) lead can be displaced by introduction of the plant containing lead into another lead solution, whereby inactive lead atoms now take the place of the radioactive ones. From this it follows that the lead is not combined with carbon within the plant, but that it exists in the form of a dissociable salt which is soluble with difficulty. Even after 24 hours, a 10/sup -1/ N solution of a lead salt produces toxic effects on the plant, while more dilute solutions do not. Lead belongs to the least poisonous of the heavy metals. 9 references.

  16. Systematic Design of the Lead-Lag Network Method for Active Damping in LCL-Filter Based Three Phase Converters

    DEFF Research Database (Denmark)

    Alzola, Rafael Pena; Liserre, Marco; Blaabjerg, Frede

    2014-01-01

    ) nor its rationale has been explained. Thus, in this paper a straightforward procedure is developed to tune the lead-lag network with the help of software tools. The rationale of this procedure, based on the capacitor current feedback, is elucidated. Stability is studied by means of the root locus......Three-phase active rectifiers guarantee sinusoidal input currents and unity power factor at the price of a high switching frequency ripple. To adopt an LCL-filter, instead of an L-filter, allows using reduced values for the inductances and so preserving dynamics. However, stability problems can...... without using dissipative elements but, sometimes, needing additional sensors. This solution has been addressed in many publications. The lead-lag network method is one of the first reported procedures and continues being in use. However, neither there is a direct tuning procedure (without trial and error...

  17. Determination of lead element trace in some Syrian cigarettes and Its mixtures using voltammetric method on HMDE

    International Nuclear Information System (INIS)

    Nasser, H.; Kabass, H.

    2010-01-01

    This study aims for estimating of trace for these elements in various brands of Syrian Cigarettes and its mixtures, by using voltammetric method (HMDE) hanging mercury drop elec trod. This method is first used to determined Syrian Cigarettes brand and its mixtures, during this study it was found that we can use it easily with low commission, high sensitivity and accurate results comparing with others studies. We prepare the samples by using reference methods. The samples were collected during two times in one year from the same kinds of samples. We noticed that the high concentrations was (3.795μg/g) in Gitanes samples, and the low concentrations in shame samples was (0.37 μg/g). This study refers that there is different concentrations of lead element in this samples.(author)

  18. Adequacy and validation of an analytical method for the quantification of lead in chamomile tisanes produced in Costa Rica

    International Nuclear Information System (INIS)

    Blanco Barrantes, Jeimy

    2014-01-01

    An analytical methodology is developed and validated to quantify lead in chamomile tisanes. Lead is quantified by utilizing the technique of flame atomic absorption spectroscopy in three brands of chamomile tisanes sold in Costa Rica to determine its safety and quality based on international standards. A method of sample preparation is established through a comparison of different forms of extraction. The acid digestion extraction method has been the procedure utilized, reaching an average recovery percentage of 97,1%, with a standard deviation of 2,3%. The optimization of the chosen analytical procedure and complete validation is performed. The results obtained in the validation of the analytical procedure have shown that the interval where is generated the best calibration curve in terms of the correlation coefficient and the value of the statistically significant intercept equal to zero, have been the comprised between (0,2-3,2) μg/mL (r 2 =0,9996), corresponding to a range between 20% to 320% of the maximum allowed limit. In addition, the procedure has been adequate in terms of accuracy (average recovery percentage 101,1%) and precision under repeatability and intermediate precision (RSD max. 9,3%) and limit of quantification (0,2551 μg/mL). The safety criterion of World Health Organization (WHO) is determined with respect to the concentration of lead in the analyzed products. The 9 analyzed samples of products to prepare chamomile tisanes have stayed without evidencing concentrations of lead above the limit value of 10 μg/g suggested for medicinal herbs by WHO [es

  19. On the Application of Iterative Methods of Nondifferentiable Optimization to Some Problems of Approximation Theory

    Directory of Open Access Journals (Sweden)

    Stefan M. Stefanov

    2014-01-01

    Full Text Available We consider the data fitting problem, that is, the problem of approximating a function of several variables, given by tabulated data, and the corresponding problem for inconsistent (overdetermined systems of linear algebraic equations. Such problems, connected with measurement of physical quantities, arise, for example, in physics, engineering, and so forth. A traditional approach for solving these two problems is the discrete least squares data fitting method, which is based on discrete l2-norm. In this paper, an alternative approach is proposed: with each of these problems, we associate a nondifferentiable (nonsmooth unconstrained minimization problem with an objective function, based on discrete l1- and/or l∞-norm, respectively; that is, these two norms are used as proximity criteria. In other words, the problems under consideration are solved by minimizing the residual using these two norms. Respective subgradients are calculated, and a subgradient method is used for solving these two problems. The emphasis is on implementation of the proposed approach. Some computational results, obtained by an appropriate iterative method, are given at the end of the paper. These results are compared with the results, obtained by the iterative gradient method for the corresponding “differentiable” discrete least squares problems, that is, approximation problems based on discrete l2-norm.

  20. Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10).

    Science.gov (United States)

    Beltrán, Blanca; Avivar, Jessica; Mola, Montserrat; Ferrer, Laura; Cerdà, Víctor; Leal, Luz O

    2013-09-03

    A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

  1. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    Energy Technology Data Exchange (ETDEWEB)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E{sub efective} = 33 keV), N-80 (E{sub efective} = 65 keV) and N-100 (E{sub efective} = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  2. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    International Nuclear Information System (INIS)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A.; Vega C, H. R.

    2016-10-01

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E_e_f_e_c_t_i_v_e = 33 keV), N-80 (E_e_f_e_c_t_i_v_e = 65 keV) and N-100 (E_e_f_e_c_t_i_v_e = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  3. Determination of temperature dependence of piezoelectric coefficients matrix of lead zirconate titanate ceramics by quasi-static and resonance method

    Energy Technology Data Exchange (ETDEWEB)

    Li Fei; Xu Zhuo; Wei Xiaoyong; Yao Xi, E-mail: lifei1216@gmail.co [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China)

    2009-05-07

    The piezoelectric coefficients (d{sub 33}, -d{sub 31}, d{sub 15}, g{sub 33}, -g{sub 31}, g{sub 15}) of soft and hard lead zirconate titanate ceramics were measured by the quasi-static and resonance methods, at temperatures from 20 to 300 {sup 0}C. The results showed that the piezoelectric coefficients d{sub 33}, -d{sub 31} and d{sub 15} obtained by these two methods increased with increasing temperature for both hard and soft PZT ceramics, while the piezoelectric coefficients g{sub 33}, -g{sub 31} and g{sub 15} decreased with increasing temperature for both hard and soft PZT ceramics. In this paper, the observed results were also discussed in terms of intrinsic and extrinsic contributions to piezoelectric response.

  4. Determination of temperature dependency of material parameters for lead-free alkali niobate piezoceramics by the inverse method

    Directory of Open Access Journals (Sweden)

    K. Ogo

    2016-06-01

    Full Text Available Sodium potassium niobate (NKN piezoceramics have been paid much attention as lead-free piezoelectric materials in high temperature devices because of their high Curie temperature. The temperature dependency of their material parameters, however, has not been determined in detail up to now. For this purpose, we exploit the so-called Inverse Method denoting a simulation-based characterization approach. Compared with other characterization methods, the Inverse Method requires only one sample shape of the piezoceramic material and has further decisive advantages. The identification of material parameters showed that NKN is mechanically softer in shear direction compared with lead zirconate titanate (PZT at room temperature. The temperature dependency of the material parameters of NKN was evaluated in the temperature range from 30 °C to 150 °C. As a result, we figured out that dielectric constants and piezoelectric constants show a monotonous and isotropic increment with increasing temperature. On the other hand, elastic stiffness constant c 44 E of NKN significantly decreased in contrast to other elastic stiffness constants. It could be revealed that the decrement of c 44 E is associated with an orthorhombic-tetragonal phase transition. Furthermore, ratio of elastic compliance constants s 44 E / s 33 E exhibited similar temperature dependent behavior to the ratio of piezoelectric constants d15/d33. It is suspected that mechanical softness in shear direction is one origin of the large piezoelectric shear mode of NKN. Our results show that NKN are suitable for high temperature devices, and that the Inverse Method should be a helpful approach to characterize material parameters under their practical operating conditions for NKN.

  5. Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods.

    Science.gov (United States)

    Singh, Nahar; Singh, Niranjan; Tripathy, S Swarupa; Soni, Daya; Singh, Khem; Gupta, Prabhat K

    2013-06-26

    A conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stick in 5% ultra pure nitric acid. From the stock solution five replicates of approximate 50 g have been taken for determination of purity by each method. The Pb has been determined as PbSO4 by conventional gravimetry, as PbO2 by electro gravimetry. The percentage purity of the metallic Pb was calculated accordingly from PbSO4 and PbO2. On the basis of experimental observations it has been concluded that by conventional gravimetry and electro-gravimetry the purity of Pb was found to be 99.98 ± 0.24 and 99.97 ± 0.27 g/100 g and on the basis of Pb purity the concentration of reference standard solutions were found to be 1000.88 ± 2.44 and 1000.81 ± 2.68 mg kg-1 respectively with 95% confidence level (k = 2). The uncertainty evaluation has also been carried out in Pb determination following EURACHEM/GUM guidelines. The final analytical results quantifying uncertainty fulfills this requirement and gives a measure of the confidence level of the concerned laboratory. Gravimetry is the most reliable technique in comparison to titremetry and instrumental method and the results of gravimetry are directly traceable to SI unit. Gravimetric analysis, if methods are followed carefully, provides for exceedingly precise analysis. In classical gravimetry the major uncertainties are due to repeatability but in electro-gravimetry several other factors also affect the final results.

  6. Apparatus and methods for recovery of lead oxide from production and application wastes of lead storage battery production or of lead storage batteries themselves. Verfahren und Anordnung zur Rueckgewinnung von Bleioxyd aus Produktions- und Anwendungsabfaellen der Bleiakkumulatorherstellung beziehungsweise der Bleiakkumulatoren

    Energy Technology Data Exchange (ETDEWEB)

    Szalay, G; Gyoeroek, A; Orgovan, G

    1982-11-04

    For reasons of economy and pollution control, aqueous lead-oxide-containing wastes from the various steps of lead storage battery production are reprocessed involving e.g. a vibrating screen for separating foreign matter and particles larger than 0.2 mm, dewatering of the residual paste by centrifuging for recycling the thickened product to the production process at an H/sub 2/O content of some 20 wt%. Largish particles separated by the screen can be re-used after being finely ground; the water may be recycled just as well or be discharged following neutralisation.

  7. Use of the transpiration method to study polonium evaporation from liquid lead-bismuth eutectic at high temperature

    International Nuclear Information System (INIS)

    Prieto, Borja Gonzalez; Lim, Jun; Rosseel, Kris; Bosch, Joris van den; Aerts, Alexander; Martens, Johan; Rizzi, Matthias; Neuhausen, Joerg

    2014-01-01

    Qualitative and quantitative understanding of Po volatilization under different conditions is of key importance for safety assessments of lead-bismuth eutectic (LBE) based nuclear reactors, spallation targets and accelerator driven systems. In this work we explore the possibilities of the transpiration method in combination with simple models to study the equilibrium and kinetics of Po evaporation from highly diluted solutions in lead-bismuth eutectic between 600 and 1000 C in Ar/5% H 2 and Ar. On the basis of evaporation experiments at various carrier gas flow rates, we identified the conditions of vapor saturation allowing the determination of equilibrium constants. From the limiting behavior at high flow rates, values for the maximal evaporation rate of Po from LBE were estimated. Measurements of evaporation as a function of time were consistent with the assumption that polonium dissolved in LBE obeys Henry's law. A theoretical analysis furthermore suggested that diffusion of polonium in LBE was not a rate limiting factor for evaporation under vapor saturation conditions. Newly determined values for the Henry constant of Po in LBE between 600 and 1000 C were consistent with previously derived correlations.

  8. Measurement of disintegration rates of small [60Co]Co sources in lead containers by the sum-peak method

    International Nuclear Information System (INIS)

    Kawano, Takao; Ebihara, Hiroshi

    1991-01-01

    The sum-peak method has been applied to determine the disintegration rates of two small [ 60 Co]Co sources (30 and 350 kBq) in lead containers with several thickness by using a NaI(Tl) detector. The experimental results showed that the sum-peak method was perfectly effective for the determination of the disintegration rates (unrelated to the thicknesses of the containers) of the 350 kBq source. The sum-peak method was also absolutely effective for the 30 kBq source in the case of containers with thicknesses of 15 mm and less, but in the cases of those with thicknesses of 21, 27 and 33 mm, the disintegration rates were under-estimated and the deviations from the true disintegration rate increased rapidly with increasing thicknesses of the containers. We presume that the under-estimation of the disintegration rates was the result of the over-estimation of the areas under the sum peaks, caused by the interference of the γ-ray (2614 keV) emitted from the naturally occurring radionuclide 208 Tl. (author)

  9. High-dose biotin therapy leading to false biochemical endocrine profiles: validation of a simple method to overcome biotin interference.

    Science.gov (United States)

    Piketty, Marie-Liesse; Prie, Dominique; Sedel, Frederic; Bernard, Delphine; Hercend, Claude; Chanson, Philippe; Souberbielle, Jean-Claude

    2017-05-01

    High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS) and is expected to be adopted by a large number of patients. Biotin therapy leads to analytical interference in many immunoassays that utilize streptavidin-biotin capture techniques, yielding skewed results that can mimic various endocrine disorders. We aimed at exploring this interference, to be able to remove biotin and avoid misleading results. We measured free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), parathyroid homrone (PTH), 25-hydroxyvitamin D (25OHD), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, C-peptide, cortisol (Roche Diagnostics assays), biotin and its main metabolites (liquid chromatography tandem mass spectrometry) in 23 plasmas from MS patients and healthy volunteers receiving high-dose biotin, and in 39 biotin-unsupplemented patients, before and after a simple procedure (designated N5) designed to remove biotin by means of streptavidin-coated microparticles. We also assayed fT4, TSH and PTH in the 23 high-biotin plasmas using assays not employing streptavidin-biotin binding. The biotin concentration ranged from 31.7 to 1160 µg/L in the 23 high-biotin plasmas samples. After the N5 protocol, the biotin concentration was below the detection limit in all but two samples (8.3 and 27.6 μg/L). Most hormones results were abnormal, but normalized after N5. All results with the alternative methods were normal except two slight PTH elevations. In the 39 biotin-unsupplemented patients, the N5 protocol did not affect the results for any of the hormones, apart from an 8.4% decrease in PTH. We confirm that most streptavidin-biotin hormone immunoassays are affected by high biotin concentrations, leading to a risk of misdiagnosis. Our simple neutralization method efficiently suppresses biotin interference.

  10. Real-Time Pricing for Demand Response in Smart Grid Based on Alternating Direction Method of Multipliers

    Directory of Open Access Journals (Sweden)

    Hongbo Zhu

    2018-01-01

    Full Text Available The real-time pricing (RTP scheme is an ideal method to adjust the power balance between supply and demand in smart grid systems. This scheme has a profound impact on users’ behavior, system operation, and overall grid management in the electricity industry. In this research, we conduct an extended discussion of a RTP optimization model and give a theoretical analysis of the existence and uniqueness of the Lagrangian multiplier. A distributed optimization method based on the alternating direction method of multipliers (ADMM algorithm with Gaussian back substitution (GBS is proposed in this study. On the one hand, the proposed algorithm takes abundant advantage of the separability among variables in the model. On the other hand, the proposed algorithm can not only speed up the convergence rate to enhance the efficiency of computing, but also overcome the deficiency of the distributed dual subgradient algorithm, the possibility of nonconvergence in the iteration process. In addition, we give the theoretical proof of the convergence of the proposed algorithm. Furthermore, the interdependent relationship between variables has been discussed in depth during numerical simulations in the study. Compared with the dual subgradient method, the simulation results validate that the proposed algorithm has a higher convergence speed and better implementation effect.

  11. A rapid method for simultaneous determination of arsenic, cadmium and lead in drinking water by inductively coupled plasma mass spectrometry

    Directory of Open Access Journals (Sweden)

    Joshua Rey P. Torres

    Full Text Available The raw water source of drinking water in most areas in the Philippines is typically river water and in some cases groundwater. These sources are prone to elevated levels of metals and metalloids that may cause exposure of the general population when the treatment of the water is inadequate. This work presents a simple method based on EPA Method 200.8 for the determination of total concentrations of arsenic (As, cadmium (Cd and lead (Pb in drinking water using inductively coupled plasma-mass spectrometry (ICP-MS as the element-selective detector. This was applied in the determination of these elements in the water supply in Metro Manila, Philippines. The method detection limits were 0.095 μg L-1, 0.043 μg L-1, and 0.114 μg L-1 for total As, Cd and Pb, respectively.The method was validated using National Institute of Standards and Technology (NIST 1643e certified reference material for trace elements in water and determined values were 60.4 ± 0.5 μg L-1, 6.7 ± 0.1 μg L-1, and 19.6 ± 0.5 μg L-1 for As, Cd and Pb, respectively. These determined values were in good agreement with the certified values in the reference material. Analysis of actual drinking water samples showed that most samples did not exceed the limit of the Philippine drinking water standard for the elements.

  12. Effects of different soil remediation methods on inhibition of lead absorption and growth and quality of Dianthus superbus L.

    Science.gov (United States)

    Yang, Xiaoyu; Ma, Siyue; Li, Jianheng

    2017-12-01

    Heavy metal pollution in soil poses a serious threat to the growth of plants used in traditional Chinese medicine. Therefore, a pot experiment was conducted to study the effects of various soil remediation methods on the performance of Herba Dianthi (Dianthus superbus L.) grown on Pb-contaminated soil. The results show that inoculation of Herba Dianthi with arbuscular mycorrhizal fungi (AMF) led to a significant reduction in Pb uptake (P< 0.05), and increased root development and root-to-shoot ratio compared to untreated control plants, along with the highest content of active components. When planting with Trifolium repens, the reduction effect of Pb absorption was insignificant. Herba Dianthi showed improved growth and active ingredients, and the lowest Pb content, with AMF inoculation. The addition of EDTA decreased the growth of Herba Dianthi, but promoted the absorption of Pb. The inhibition of tumor cells was highest in E2. In conclusion, inoculation with AMF can ensure that plant lead content meets testing standards, helping to improve the quality of medicinal herbs.

  13. Development of combinatorial chemistry methods for coatings: high-throughput adhesion evaluation and scale-up of combinatorial leads.

    Science.gov (United States)

    Potyrailo, Radislav A; Chisholm, Bret J; Morris, William G; Cawse, James N; Flanagan, William P; Hassib, Lamyaa; Molaison, Chris A; Ezbiansky, Karin; Medford, George; Reitz, Hariklia

    2003-01-01

    Coupling of combinatorial chemistry methods with high-throughput (HT) performance testing and measurements of resulting properties has provided a powerful set of tools for the 10-fold accelerated discovery of new high-performance coating materials for automotive applications. Our approach replaces labor-intensive steps with automated systems for evaluation of adhesion of 8 x 6 arrays of coating elements that are discretely deposited on a single 9 x 12 cm plastic substrate. Performance of coatings is evaluated with respect to their resistance to adhesion loss, because this parameter is one of the primary considerations in end-use automotive applications. Our HT adhesion evaluation provides previously unavailable capabilities of high speed and reproducibility of testing by using a robotic automation, an expanded range of types of tested coatings by using the coating tagging strategy, and an improved quantitation by using high signal-to-noise automatic imaging. Upon testing, the coatings undergo changes that are impossible to quantitatively predict using existing knowledge. Using our HT methodology, we have developed several coatings leads. These HT screening results for the best coating compositions have been validated on the traditional scales of coating formulation and adhesion loss testing. These validation results have confirmed the superb performance of combinatorially developed coatings over conventional coatings on the traditional scale.

  14. Investigating the Formation Process of Sn-Based Lead-Free Nanoparticles with a Chemical Reduction Method

    International Nuclear Information System (INIS)

    Zhang, W.; Zhao, B.; Gao, Y.; Zhang, W.; Zhao, B.; Zou, Ch.; Zhai, Q.; Gao, Y.; Gao, Y.; Acquah, S.F.A.

    2013-01-01

    Nanoparticles of a promising lead-free solder alloy (Sn 3.5 Ag (wt.%, Sn Ag) and Sn 3.0 Ag 0.5 Cu (wt.%, SAC)) were synthesized through a chemical reduction method by using anhydrous ethanol and 1,10-phenanthroline as the solvent and surfactant, respectively. To illustrate the formation process of Sn-Ag alloy based nanoparticles during the reaction, X-ray diffraction (XRD) was used to investigate the phases of the samples in relation to the reaction time. Different nucleation and growth mechanisms were compared on the formation process of the synthesized nanoparticles. The XRD results revealed different reaction process compared with other researchers. There were many contributing factors to the difference in the examples found in the literature, with the main focus on the formation mechanism of crystal nuclei, the solubility and ionizability of metal salts in the solvent, the solid solubility of Cu in Ag nuclei, and the role of surfactant on the growth process. This study will help define the parameters necessary for the control of both the composition and size of the nanoparticles

  15. An improved partial bundle method for linearly constrained minimax problems

    Directory of Open Access Journals (Sweden)

    Chunming Tang

    2016-02-01

    Full Text Available In this paper, we propose an improved partial bundle method for solving linearly constrained minimax problems. In order to reduce the number of component function evaluations, we utilize a partial cutting-planes model to substitute for the traditional one. At each iteration, only one quadratic programming subproblem needs to be solved to obtain a new trial point. An improved descent test criterion is introduced to simplify the algorithm. The method produces a sequence of feasible trial points, and ensures that the objective function is monotonically decreasing on the sequence of stability centers. Global convergence of the algorithm is established. Moreover, we utilize the subgradient aggregation strategy to control the size of the bundle and therefore overcome the difficulty of computation and storage. Finally, some preliminary numerical results show that the proposed method is effective.

  16. An analytically-based method for predicting the noise generated by the interaction between turbulence and a serrated leading edge

    Science.gov (United States)

    Mathews, J. R.; Peake, N.

    2018-05-01

    This paper considers the interaction of turbulence with a serrated leading edge. We investigate the noise produced by an aerofoil moving through a turbulent perturbation to uniform flow by considering the scattered pressure from the leading edge. We model the aerofoil as an infinite half plane with a leading edge serration, and develop an analytical model using a Green's function based upon the work of Howe. This allows us to consider both deterministic eddies and synthetic turbulence interacting with the leading edge. We show that it is possible to reduce the noise by using a serrated leading edge compared with a straight edge, but the optimal noise-reducing choice of serration is hard to predict due to the complex interaction. We also consider the effect of angle of attack, and find that in general the serrations are less effective at higher angles of attack.

  17. Are automated molecular dynamics simulations and binding free energy calculations realistic tools in lead optimization? An evaluation of the linear interaction energy (LIE) method

    NARCIS (Netherlands)

    Stjernschantz, E.M.; Marelius, J.; Medina, C.; Jacobsson, M.; Vermeulen, N.P.E.; Oostenbrink, C.

    2006-01-01

    An extensive evaluation of the linear interaction energy (LIE) method for the prediction of binding affinity of docked compounds has been performed, with an emphasis on its applicability in lead optimization. An automated setup is presented, which allows for the use of the method in an industrial

  18. Gamma/hadron segregation for a ground based imaging atmospheric Cherenkov telescope using machine learning methods: Random Forest leads

    International Nuclear Information System (INIS)

    Sharma Mradul; Koul Maharaj Krishna; Mitra Abhas; Nayak Jitadeepa; Bose Smarajit

    2014-01-01

    A detailed case study of γ-hadron segregation for a ground based atmospheric Cherenkov telescope is presented. We have evaluated and compared various supervised machine learning methods such as the Random Forest method, Artificial Neural Network, Linear Discriminant method, Naive Bayes Classifiers, Support Vector Machines as well as the conventional dynamic supercut method by simulating triggering events with the Monte Carlo method and applied the results to a Cherenkov telescope. It is demonstrated that the Random Forest method is the most sensitive machine learning method for γ-hadron segregation. (research papers)

  19. Study on complexed lead and cadmium ions removal from aqueous solutions by means of ion exchange method

    International Nuclear Information System (INIS)

    Dudzinska, M.

    1992-01-01

    The possibility of simultaneous removal of heavy metal ions and organic chelates from waste water has been studied. The experimental work has been preceded by extensive theoretical considerations and calculations of physico-chemical parameters of the process for model and real waste water systems. The negative influence of the presence of sulfate anions on cadmium and lead complexes removal in ion exchange process has been experimentally proved. In the systems free of sulfate anions or when their concentrations were low, the purification process conducted on Amberlite IRA-68 was very effective for cadmium and lead complexes removal. 112 refs, 78 figs, 15 tabs

  20. Superconducting electron tunneling as detection method for low frequency resonant vibration modes of interstitials in fcc lead

    International Nuclear Information System (INIS)

    Adrian, H.

    1981-01-01

    The influence of crystal defects on the phonon spectra was studied for fcc lead using superconducting tunneling spectroscopy. The theory predicts low frequency modes for the vibrational states of interstitials in (100) dumbbell configuration. Low temperature irradiation of superconducting point contacts with fast ions (point contact thickness small compared to the average ion range) showed radiation-induced structures in the low-energy part of the Eliashberg function for lead. These resonant modes are reduced by annealing at 18.5 K; they are attributed to small interstitial clusters. The radiation-induced structures are completely removed by room temperature annealing. (orig.)

  1. Efficacy of aprons equivalent to 0.5 mm of lead in PET procedures using the Monte Carlo method

    International Nuclear Information System (INIS)

    Fonseca, R.B.; Amaral, A.; Campos, L.

    2012-01-01

    In positron emission tomography (PET), health staff is exposed to 511-keV photons, which is a result of the positron annihilation process. This energy is about four times greater than the 140 keV commonly found in studies based on single photon emission computed tomography (SPECT). Besides this different level of energy, 0.5 mm lead-equivalent aprons have being used either in SPECT or PET procedures. In this context, this work was designed for evaluating the effectiveness of such aprons in individual radioprotection of health professionals involved in positron emission tomography. For this, by using MCNP4C-based Monte Carlo simulations, the average energy delivered per particle to the regions corresponding to operational quantities Hp(10) and Hp(0.07) were calculated for two conditions of individual exposures: wearing and not wearing a 0.05 mm lead-equivalent apron. The results obtained pointed out that Hp(10) has similar value in both situations. On the other hand, for the region corresponding to Hp(0.07), wearing this lead apron will improve this dose in about 26%. On the basis of this work, 0.5 mm lead equivalent aprons do not offer adequate protection for medical staff working on positron emission tomography. (author)

  2. An evaluation of sampling methods and supporting techniques for tackling lead in drinking water in Aberta Province

    Science.gov (United States)

    A collaborative project commenced in August 2013 with the aim of demonstrating a range of techniques that can be used in tackling the problems of lead in drinking water. The main project was completed in March 2014, with supplementary sampling exercises in mid-2014. It involved t...

  3. A note on the catch-up time method for estimating lead or sojourn time in prostate cancer screening

    NARCIS (Netherlands)

    G. Draisma (Gerrit); J.M. van Rosmalen (Joost)

    2013-01-01

    textabstractModels of cancer screening assume that cancers are detectable by screening before being diagnosed clinically through symptoms. The duration of this preclinical phase is called sojourn time, and it determines how much diagnosis might be advanced in time by the screening test (lead time).

  4. Lead poisoning

    Science.gov (United States)

    ... drinking water in homes containing pipes that were connected with lead solder . Although new building codes require ... lead in their bodies when they put lead objects in their mouths, especially if they swallow those ...

  5. 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 ...

  6. Applicability of linearized-theory attached-flow methods to design and analysis of flap systems at low speeds for thin swept wings with sharp leading edges

    Science.gov (United States)

    Carlson, Harry W.; Darden, Christine M.

    1987-01-01

    Low-speed experimental force and data on a series of thin swept wings with sharp leading edges and leading and trailing-edge flaps are compared with predictions made using a linearized-theory method which includes estimates of vortex forces. These comparisons were made to assess the effectiveness of linearized-theory methods for use in the design and analysis of flap systems in subsonic flow. Results demonstrate that linearized-theory, attached-flow methods (with approximate representation of vortex forces) can form the basis of a rational system for flap design and analysis. Even attached-flow methods that do not take vortex forces into account can be used for the selection of optimized flap-system geometry, but design-point performance levels tend to be underestimated unless vortex forces are included. Illustrative examples of the use of these methods in the design of efficient low-speed flap systems are included.

  7. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM)

    International Nuclear Information System (INIS)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier

    2013-01-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption

  8. A new probability density function for spatial distribution of soil water storage capacity leads to SCS curve number method

    OpenAIRE

    Wang, Dingbao

    2018-01-01

    Following the Budyko framework, soil wetting ratio (the ratio between soil wetting and precipitation) as a function of soil storage index (the ratio between soil wetting capacity and precipitation) is derived from the SCS-CN method and the VIC type of model. For the SCS-CN method, soil wetting ratio approaches one when soil storage index approaches infinity, due to the limitation of the SCS-CN method in which the initial soil moisture condition is not explicitly represented. However, for the ...

  9. Refinement of the crystal structure of lead titanate with different degrees of imperfection of cationic and anionic sublattices by the Rietveld method

    International Nuclear Information System (INIS)

    Akimov, A.I.; Savchuk, G.K.; Rubtsov, V.A.; Letko, A.K.

    2003-01-01

    The parameters of the crystal structure of lead titanate with different degrees of imperfection of the anionic and cationic sublattices are refined by the Rietveld method. The experiments are carried out on a DRON-4 diffractometer (CuK α radiation; 20 deg. d 5.0-6.0%

  10. Analysis of operator support method based on intelligent dynamic interlock in lead-cooled fast reactor simulator

    International Nuclear Information System (INIS)

    Xu, Peng; Wang, Jianye; Yang, Minghan; Wang, Weitian; Bai, Yunqing; Song, Yong

    2017-01-01

    Highlights: • We development an operator support method based on intelligent dynamic interlock. • We offer an integrated aid system to reduce the working strength of operators. • The method can help operators avoid dangerous, irreversible operation. • This method can be used in the fusion research reactor in the further. - Abstract: In nuclear systems, operators have to carry out corrective actions when abnormal situations occur. However, operators might make mistakes under pressure. In order to avoid serious consequences of the human errors, a new method for operators support based on intelligent dynamic interlock was proposed. The new method based on full digital instrumentation and control system, contains real-time alarm analysis process, decision support process and automatic safety interlock process. Once abnormal conditions occur, necessary safety interlock parameter based on analysis of real-time alarm and decision support process can be loaded into human-machine interfaces and controllers automatically, and avoid human errors effectively. Furthermore, the new method can make recommendations for further use and development of this technique in nuclear power plant or fusion research reactor.

  11. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  12. Effectiveness of silica based Sol-gel microencapsulation Method for odorants and flavours leading to sustainable Environment

    Directory of Open Access Journals (Sweden)

    Muhammad Aqeel eAshraf

    2015-08-01

    Full Text Available Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol–gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol–gel SiO2 is non-toxic and safe, whereas the sol–gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped actives, thereby broadening the practical utilization of chemically unstable essential oils. Reviewing progress in the fabrication of diverse odorant and flavoured sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits.

  13. Effectiveness of silica based sol-gel microencapsulation method for odorants and flavors leading to sustainable environment

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Khan, Aysha Masood; Ahmad, Mushtaq; Sarfraz, Maliha

    2015-01-01

    Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered economically cheap as capital investment in manufacturing is very low and environmentally friendly. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chemicals in its inner pores results in pronounced chemical and physical stabilization of the entrapped active agents, thereby broadening the practical utilization of chemically unstable essential oils (EOs). Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, shows us how different synthetic strategies are appropriate for practical application with important health and environmental benefits. PMID:26322304

  14. Lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Beijers, J A

    1952-01-01

    Three cases of acute lead poisoning of cattle herds via ingestion are reported, and reference is made to several other incidents of lead in both humans and animals. The quantity of lead which was found in the livers of the dead cows varied from 6.5 to 19 mg/kg, while 1160 mg/kg of lead in the liver was found for a young cow which was poisoned experimentally with 5 gms of lead acetate per day; hence, there appears to be great variability in the amounts deposited that can lead to intoxication and death. No evidence was found for a lead seam around the teeth, prophyrinuria, or basophil granules in the erythrocytes during acute or chronic lead poisoning of cattle or horses examined. Reference is made to attempts of finding the boundary line between increased lead absorption and lead intoxication in humans, and an examination of 60 laborers in an offset-printing office containing a great deal of inhalable lead (0.16 to 1.9 mg/cu m air) is reviewed. Physical deviation, basophylic granulation of erythrocytes, increased lead content of the urine, and porphyrinuria only indicate an increased absorption of lead; the use of the term intoxication is justified if, in addition, there are complaints of lack of appetite, constipation, fatigue, abdominal pain, and emaciation.

  15. Lead Toxicity

    Science.gov (United States)

    ... o Do not use glazed ceramics, home remedies, cosmetics, or leaded-crystal glassware unless you know that they are lead safe. o If you live near an industry, mine, or waste site that may have contaminated ...

  16. A Mixed Methods Study: Principals' Perceived Leadership Styles and Ability to Lead during a School Violence Crisis

    Science.gov (United States)

    Henderson, Joyce Herod

    2013-01-01

    Our schools are considered a place of safety for learning, however, the unfortunate reality is that schools may face crises and violence. Leadership styles vary among school leaders and provide the framework for handling daily challenges. This mixed-methods research design was used to investigate the individual leadership styles of public school…

  17. Influence of digestion methods on the recovery of Iron, Zinc, Nickel, Chromium, Cadmium and Lead contents in 11 organic residues

    Directory of Open Access Journals (Sweden)

    Thalita Fernanda Abbruzzini

    2014-02-01

    Full Text Available There are currently many devices and techniques to quantify trace elements (TEs in various matrices, but their efficacy is dependent on the digestion methods (DMs employed in the opening of such matrices which, although "organic", present inorganic components which are difficult to solubilize. This study was carried out to evaluate the recovery of Fe, Zn, Cr, Ni, Cd and Pb contents in samples of composts and cattle, horse, chicken, quail, and swine manures, as well as in sewage sludges and peat. The DMs employed were acid digestion in microwaves with HNO3 (EPA 3051A; nitric-perchloric digestion with HNO3 + HClO4 in a digestion block (NP; dry ashing in a muffle furnace and solubilization of residual ash in nitric acid (MDA; digestion by using aqua regia solution (HCl:HNO3 in the digestion block (AR; and acid digestion with HCl and HNO3 + H2O2 (EPA 3050. The dry ashing method led to the greatest recovery of Cd in organic residues, but the EPA 3050 protocol can be an alternative method for the same purpose. The dry ashing should not be employed to determine the concentration of Cr, Fe, Ni, Pb and Zn in the residues. Higher Cr and Fe contents are recovered when NP and EPA 3050 are employed in the opening of organic matrices. For most of the residues analyzed, AR is the most effective method for recovering Ni. Microwave-assisted digestion methods (EPA3051 and 3050 led to the highest recovery of Pb. The choice of the DM that provides maximum recovery of Zn depends on the organic residue and trace element analyzed.

  18. 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....

  19. Lead Test

    Science.gov (United States)

    ... to do renovation and repair projects using lead-safe work practices to avoid creating more lead dust or ... in a dangerous area? Yes. If you are working in a potentially harmful environment with exposure to lead dust or fumes: Wash ...

  20. Development and validation of an analytical method for the determination of lead isotopic composition using ICP-QMS

    OpenAIRE

    Rodríguez-Salazar, M. T.; Morton Bermea, O.; Hernández-Álvarez, E.; García-Arreola, M. E.; Ortuño-Arzate, M. T.

    2010-01-01

    This work reports a method for the precise and accurate determination of Pb isotope composition in soils and geological matrices by ICP-QMS. Three reference materials (AGV-2, SRM 2709 and JSO-1) were repeatedly measured, using ICP-QMS instruments in order to assess the quality of this analytical procedure. Mass discrimination was evaluated for Pb/Pb with Pb isotope reference material NIST SRM 981, and the correction applied to the above mentioned reference materials to achieve good accuracy o...

  1. An Approximate Proximal Bundle Method to Minimize a Class of Maximum Eigenvalue Functions

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-01-01

    Full Text Available We present an approximate nonsmooth algorithm to solve a minimization problem, in which the objective function is the sum of a maximum eigenvalue function of matrices and a convex function. The essential idea to solve the optimization problem in this paper is similar to the thought of proximal bundle method, but the difference is that we choose approximate subgradient and function value to construct approximate cutting-plane model to solve the above mentioned problem. An important advantage of the approximate cutting-plane model for objective function is that it is more stable than cutting-plane model. In addition, the approximate proximal bundle method algorithm can be given. Furthermore, the sequences generated by the algorithm converge to the optimal solution of the original problem.

  2. Technology-based vs. traditional instruction. A comparison of two methods for teaching the skill of performing a 12-lead ECG.

    Science.gov (United States)

    Jeffries, Pamela R; Woolf, Shirley; Linde, Beverly

    2003-01-01

    The purpose of this study was to compare the effectiveness of an interactive, multimedia CD-ROM with traditional methods of teaching the skill of performing a 12-lead ECG. A randomized pre/posttest experimental design was used. Seventy-seven baccalaureate nursing students in a required, senior-level critical-care course at a large midwestern university were recruited for the study. Two teaching methods were compared. The traditional method included a self-study module, a brief lecture and demonstration by an instructor, and hands-on experience using a plastic manikin and a real 12-lead ECG machine in the learning laboratory. The second method covered the same content using an interactive, multimedia CD-ROM embedded with virtual reality and supplemented with a self-study module. There were no significant (p method, or perception of self-efficacy in performing the skill. Overall results indicated that both groups were satisfied with their instructional method and were similar in their ability to demonstrate the skill correctly on a live, simulated patient. This evaluation study is a beginning step to assess new and potentially more cost-effective teaching methods and their effects on student learning outcomes and behaviors, including the transfer of skill acquisition via a computer simulation to a real patient.

  3. Determining the bioavailability and toxicity of lead contamination to earthworms requires using a combination of physicochemical and biological methods

    International Nuclear Information System (INIS)

    Luo, Wei; Verweij, Rudo A.; Gestel, Cornelis A.M. van

    2014-01-01

    This study aimed at assessing the bioavailability and toxicity of lead to Eisenia andrei in shooting range soils representing different land uses (forest, grassland, bullet plot). Soils contained 47–2398 mg Pb/kg dry weight (dw), but also had different pH-CaCl 2 (3.2–6.8) and organic matter contents (3.8–13%). Therefore artificial soils with different pH and organic matter contents and two natural soils were included as control soils. Earthworms were exposed for 28 days and toxicity and uptake of Pb were related to total, water and 0.01 M CaCl 2 extractable and porewater Pb concentrations as well as to soil characteristics. Pb uptake in the earthworms linearly increased with increasing soil concentrations. At >2000 mg Pb/kg dw and pH 3.3–3.5, high earthworm mortality with significant weight loss and complete inhibition of reproduction were recorded. At <1000 mg/kg dw, earthworm reproduction was more related to differences in pH and other soil characteristics than to Pb. -- Highlights: • Availability and earthworm toxicity of Pb determined in field-contaminated soils. • Earthworm toxicity of most-polluted soils explained from available Pb levels. • Earthworm response in less polluted soils mainly determined by soil pH. • Earthworm toxicity correlated with Pb uptake from the soil. • Soil properties explained differences in earthworm Pb uptake and effects. -- Combination of physicochemical and biological assays helped explaining Pb toxicity in shooting range soils from available Pb concentrations and soil characteristics

  4. Methods of securing and controlling critical infrastructure assets allocated in information and communications technology sector companies in leading

    Directory of Open Access Journals (Sweden)

    Piotr Sieńko

    2015-12-01

    Full Text Available Critical Infrastructure (CI plays a significant role in maintaining public order and national security. The state may use many different methods to protect and control CI allocated to commercial companies. This article describes the three most important ones: legislation, ownership and government institutions and agencies. The data presented in this paper is the result of research done on the most developed countries in the EU (United Kingdom, France, Germany and Italy and their strategic enterprises in the ICT sector, one of the most important sectors in any national security system.

  5. Different partial volume correction methods lead to different conclusions: An (18)F-FDG-PET study of aging.

    Science.gov (United States)

    Greve, Douglas N; Salat, David H; Bowen, Spencer L; Izquierdo-Garcia, David; Schultz, Aaron P; Catana, Ciprian; Becker, J Alex; Svarer, Claus; Knudsen, Gitte M; Sperling, Reisa A; Johnson, Keith A

    2016-05-15

    A cross-sectional group study of the effects of aging on brain metabolism as measured with (18)F-FDG-PET was performed using several different partial volume correction (PVC) methods: no correction (NoPVC), Meltzer (MZ), Müller-Gärtner (MG), and the symmetric geometric transfer matrix (SGTM) using 99 subjects aged 65-87years from the Harvard Aging Brain study. Sensitivity to parameter selection was tested for MZ and MG. The various methods and parameter settings resulted in an extremely wide range of conclusions as to the effects of age on metabolism, from almost no changes to virtually all of cortical regions showing a decrease with age. Simulations showed that NoPVC had significant bias that made the age effect on metabolism appear to be much larger and more significant than it is. MZ was found to be the same as NoPVC for liberal brain masks; for conservative brain masks, MZ showed few areas correlated with age. MG and SGTM were found to be similar; however, MG was sensitive to a thresholding parameter that can result in data loss. CSF uptake was surprisingly high at about 15% of that in gray matter. The exclusion of CSF from SGTM and MG models, which is almost universally done, caused a substantial loss in the power to detect age-related changes. This diversity of results reflects the literature on the metabolism of aging and suggests that extreme care should be taken when applying PVC or interpreting results that have been corrected for partial volume effects. Using the SGTM, significant age-related changes of about 7% per decade were found in frontal and cingulate cortices as well as primary visual and insular cortices. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Different Partial Volume Correction Methods Lead to Different Conclusions: an 18F-FDG PET Study of Aging

    Science.gov (United States)

    Greve, Douglas N.; Salat, David H.; Bowen, Spencer L.; Izquierdo-Garcia, David; Schultz, Aaron P.; Catana, Ciprian; Becker, J. Alex; Svarer, Claus; Knudsen, Gitte; Sperling, Reisa A.; Johnson, Keith A.

    2016-01-01

    A cross-sectional group study of the effects of aging on brain metabolism as measured with 18F-FDG PET was performed using several different partial volume correction (PVC) methods: no correction (NoPVC), Meltzer (MZ), Müller-Gärtner (MG), and the symmetric geometric transfer matrix (SGTM) using 99 subjects aged 65-87 from the Harvard Aging Brain study. Sensitivity to parameter selection was tested for MZ and MG. The various methods and parameter settings resulted in an extremely wide range of conclusions as to the effects of age on metabolism, from almost no changes to virtually all of cortical regions showing a decrease with age. Simulations showed that NoPVC had significant bias that made the age effect on metabolism appear to be much larger and more significant than it is. MZ was found to be the same as NoPVC for liberal brain masks; for conservative brain masks, MZ showed few areas correlated with age. MG and SGTM were found to be similar; however, MG was sensitive to a thresholding parameter that can result in data loss. CSF uptake was surprisingly high at about 15% of that in gray matter. Exclusion of CSF from SGTM and MG models, which is almost universally done, caused a substantial loss in the power to detect age-related changes. This diversity of results reflects the literature on the metabolism of aging and suggests that extreme care should be taken when applying PVC or interpreting results that have been corrected for partial volume effects. Using the SGTM, significant age-related changes of about 7% per decade were found in frontal and cingulate cortices as well as primary visual and insular cortices. PMID:26915497

  7. An inter-laboratory trial of the unified BARGE bioaccessibility method for arsenic, cadmium and lead in soil

    International Nuclear Information System (INIS)

    Wragg, Joanna; Cave, Mark; Basta, Nick; Brandon, Esther; Casteel, Stan; Denys, Sebastien; Gron, Christian; Oomen, Agnes; Reimer, Kenneth; Tack, Karine; Van de Wiele, Tom

    2011-01-01

    The Bioaccessibility Research Group of Europe (BARGE) has carried out an inter-laboratory trial of a proposed harmonised in vitro physiologically based ingestion bioaccessibility procedure for soils, called the Unified BARGE Method (UBM). The UBM includes an initial saliva phase and simulated stomach and intestine compartments. The trial involved the participation of seven laboratories (five European and two North American) providing bioaccessibility data for As (11 samples), Cd (9 samples) and Pb (13 samples) using soils with in vivo relative bioavailability data measured using a swine model. The results of the study were compared with benchmark criteria for assessing the suitability of the UBM to provide data for human health risk assessments. Mine waste and slag soils containing high concentrations of As caused problems of poor repeatability and reproducibility which were alleviated when the samples were run at lower soil to solution ratios. The study showed that the UBM met the benchmark criteria for both the stomach and stomach and intestine phase for As. For Cd, three out of four criteria were met for the stomach phase but only one for the stomach and intestine phase. For Pb two, out of four criteria were met for the stomach phase and none for the stomach and intestine phase. However, the study recommends tighter control of pH in the stomach phase extraction to improve between-laboratory variability, more reproducible in vivo validation data and that a follow up inter-laboratory trial should be carried out.

  8. An inter-laboratory trial of the unified BARGE bioaccessibility method for arsenic, cadmium and lead in soil

    Energy Technology Data Exchange (ETDEWEB)

    Wragg, Joanna [British Geological Survey, Nottingham (United Kingdom); Cave, Mark, E-mail: mrca@bgs.ac.uk [British Geological Survey, Nottingham (United Kingdom); Basta, Nick [School of Environment and Natural Resources, Ohio State University, Columbus, OH, 43210-1085 (United States); Brandon, Esther [National Institute for Public Health and the Environment, Bilthoven (Netherlands); Casteel, Stan [College of Veterinary Medicine, University of Missouri, 65205 (United States); Denys, Sebastien [INERIS, Parc Technologique Alata, Verneuil-en-Halatte (France); Gron, Christian [DHI Water Environment Health, Horsholm (Denmark); Oomen, Agnes [National Institute for Public Health and the Environment, Bilthoven (Netherlands); Reimer, Kenneth [Environmental Sciences Group, Royal Military College of Canada, Kingston, Ontario (Canada); Tack, Karine [INERIS, Parc Technologique Alata, Verneuil-en-Halatte (France); Van de Wiele, Tom [Laboratory of Microbial Ecology and Technology, University of Ghent, Ghent (Belgium)

    2011-09-01

    The Bioaccessibility Research Group of Europe (BARGE) has carried out an inter-laboratory trial of a proposed harmonised in vitro physiologically based ingestion bioaccessibility procedure for soils, called the Unified BARGE Method (UBM). The UBM includes an initial saliva phase and simulated stomach and intestine compartments. The trial involved the participation of seven laboratories (five European and two North American) providing bioaccessibility data for As (11 samples), Cd (9 samples) and Pb (13 samples) using soils with in vivo relative bioavailability data measured using a swine model. The results of the study were compared with benchmark criteria for assessing the suitability of the UBM to provide data for human health risk assessments. Mine waste and slag soils containing high concentrations of As caused problems of poor repeatability and reproducibility which were alleviated when the samples were run at lower soil to solution ratios. The study showed that the UBM met the benchmark criteria for both the stomach and stomach and intestine phase for As. For Cd, three out of four criteria were met for the stomach phase but only one for the stomach and intestine phase. For Pb two, out of four criteria were met for the stomach phase and none for the stomach and intestine phase. However, the study recommends tighter control of pH in the stomach phase extraction to improve between-laboratory variability, more reproducible in vivo validation data and that a follow up inter-laboratory trial should be carried out.

  9. Development and optimization of a nuclear method to determine the lead concentration as an ultra-trace element in ultra-pure water

    International Nuclear Information System (INIS)

    Amara, A.; Giovagnoli, A.; Barrandon, J.N.

    1994-01-01

    Here we intend to perfect a nuclear analytical technique for the determination of lead concentration as an ultra-trace element in ultra-pure water Inmost cases the analysis of an aqueous solution is made by non-nuclear methods, therefore methods which are sensitive to the chemical form of the element to be determined. To ovoid this problem we developed a nuclear technique using a cyclotron,which allows the determination of the lead concentration in any of its chemical forms. We studied the possibilities of several incident beams, like neutral particles and charged particles. Proton activation showed to be the most sensitive of all the irradiation procedures. Several points have though be studied and developed: - an irradiation cell for liquids irradiation under a strong proton current; - the bismuth chemical separation. This element has two radio-isotopes allowing the determination of lead;-optimize the experimental irradiation and measurements parameters in order to reach the lower detection limit. At last an intercomparison of several techniques has been made for different standards. It clearly showed that, contrary to atomic,potentiometric or mass spectrometry methods,only activation technique give accurate and reproducible results. (author).1 fig., 2 tabs., 4 refs

  10. Leading Democratically

    Science.gov (United States)

    Brookfield, Stephen

    2010-01-01

    Democracy is the most venerated of American ideas, the one for which wars are fought and people die. So most people would probably agree that leaders should be able to lead well in a democratic society. Yet, genuinely democratic leadership is a relative rarity. Leading democratically means viewing leadership as a function or process, rather than…

  11. Uranium-lead systematics

    International Nuclear Information System (INIS)

    Wickman, F.E.

    1983-01-01

    The method of Levchenkov and Shukolyukov for calculating age and time disturbance of minerals without correction for original lead is generalized to include the cases when (1) original lead and radiogenic lead leach differently, and (2) the crystals studied consist of a core and a mantle. It is also shown that a straight line obtained from the solution of the equations is the locus of the isotopic composition of original lead. (Auth.)

  12. [Unification of methods for determining the trace quantities of lead, zinc, sodium and potassium ions in the assessment of drinking water adn transfusion fluid quality].

    Science.gov (United States)

    Popkov, V A; Golovina, N V; Evgrafov, A A

    2001-01-01

    The results of long-term studies made by the Department of General Chemistry, I. M. Sechenov Moscow Medical Academy, that deals with unification of methods for determining some ions of metals (lead, zinc, sodium, and potassium) in the assessment of the quality of drinking water and transfusion fluids are summarized. A procedure was developed to determine the trace impurities of zinc, lead, and silver by atomic absorption spectrometry (AAS) by using sorption concentration. C-80-2-aminothiazole, a new sorbent synthesized at the Research Institute of Polymers, was used to detect these ions in the drinking water. With regards to the chosen optimal conditions, drinking water samples were analyzed via their direct spraying in the air-acetylene flame. The prior sorption concentration determined drinking water zinc and lead ions in the concentrations equal to or less than their permissible dose concentrations. The studies indicated that the used methods to determine the trace quantities of metals in the drinking water and aqueous solutions show a high sensitivity, rapidity, simplicity of sample preparation.

  13. Leading change.

    Science.gov (United States)

    2017-02-27

    In response to feedback from nursing, midwifery and other care staff who wanted to understand better how the Leading Change, Adding Value framework applies to them, NHS England has updated its webpage to include practice examples.

  14. COMPARISON OF TWO TEMPERATURE MEASUREMENT METHODS BY UPCONVERSION FLUORESCENCE SPECTRA OF ERBIUM-DOPED LEAD-FLUORIDE NANO-GLASS-CERAMICS

    Directory of Open Access Journals (Sweden)

    V. A. Aseev

    2015-05-01

    Full Text Available The study and compare of two temperature measurement methods is performed for the case of a lead-fluoride nano-glassceramics in the range from 317 to 423 K with a view to their application to temperature sensors. A method of temperature measurement by means of violet, green and red upconversion fluorescence spectra regression on latent structures and a method of temperature measurement by two fluorescence bands intensity ratio in green range are considered. It is shown that a four-dimensional space of latent structures is an optimum one in terms of temperature measurement accuracy. It made possible temperature determining with a relative error not larger than 0.15% at temperatures higher than 340 K by making use of fluorescence spectra training set with the step of 10 K. The method using two green bands fluorescence intensity ratio is inferior by the accuracy. Independence of pump power fluctuations is a significant advantage of the second method. To take advantage of the first method a stabilization of the pump power is necessary. The results of the work can be taken into account while developing optical temperature sensors with a better performance (in relation to accuracy and measurement range compared to existing ones which utilize temperature redistribution of fluorescence intensities in two closely-spaced bands or temperature dependence of fluorescence lifetime.

  15. Separate base usages of genes located on the leading and lagging strands in Chlamydia muridarum revealed by the Z curve method

    Directory of Open Access Journals (Sweden)

    Yu Xiu-Juan

    2007-10-01

    Full Text Available Abstract Background The nucleotide compositional asymmetry between the leading and lagging strands in bacterial genomes has been the subject of intensive study in the past few years. It is interesting to mention that almost all bacterial genomes exhibit the same kind of base asymmetry. This work aims to investigate the strand biases in Chlamydia muridarum genome and show the potential of the Z curve method for quantitatively differentiating genes on the leading and lagging strands. Results The occurrence frequencies of bases of protein-coding genes in C. muridarum genome were analyzed by the Z curve method. It was found that genes located on the two strands of replication have distinct base usages in C. muridarum genome. According to their positions in the 9-D space spanned by the variables u1 – u9 of the Z curve method, K-means clustering algorithm can assign about 94% of genes to the correct strands, which is a few percent higher than those correctly classified by K-means based on the RSCU. The base usage and codon usage analyses show that genes on the leading strand have more G than C and more T than A, particularly at the third codon position. For genes on the lagging strand the biases is reverse. The y component of the Z curves for the complete chromosome sequences show that the excess of G over C and T over A are more remarkable in C. muridarum genome than in other bacterial genomes without separating base and/or codon usages. Furthermore, for the genomes of Borrelia burgdorferi, Treponema pallidum, Chlamydia muridarum and Chlamydia trachomatis, in which distinct base and/or codon usages have been observed, closer phylogenetic distance is found compared with other bacterial genomes. Conclusion The nature of the strand biases of base composition in C. muridarum is similar to that in most other bacterial genomes. However, the base composition asymmetry between the leading and lagging strands in C. muridarum is more significant than that in

  16. Contribution of Italy to the activities on intercomparison of analysis methods for seismically isolated nuclear structures: Finite element analysis of lead rubber bearings

    International Nuclear Information System (INIS)

    Dusi, A.; Forni, M.; Martelli, A.

    1998-01-01

    This paper presents a summary of the results of nonlinear Finite Element (FE) analyses carried out by ENEL-Ricerca, Hydraulic and Structural Centre and ENEA-ERG-SIEC-SISM, on Lead Rubber Bearings (LRBs). Activities were carried out in the framework of the four years' Coordinated Research Programme (CRP) of the International Atomic Energy Agency (IAEA) on I ntercomparison of Analysis Methods for Seismically Isolated Nuclear Structures . The bearing Finite Element Models (FEMs) are validated through comparisons of the numerical results with experimental test data. The reliability of FEMs for simulating the behaviour of rubber bearings is presented and discussed. (author)

  17. Using the methods of radiospectroscopy (EPR, NMR) to study the nature of the defect structure of solid solutions based on lead zirconate titanate (PZT).

    Science.gov (United States)

    Bykov, Igor; Zagorodniy, Yuriy; Yurchenko, Lesya; Korduban, Alexander; Nejezchleb, Karel; Trachevsky, Vladimir; Dimza, Vilnis; Jastrabik, Lubomir; Dejneka, Alexander

    2014-08-01

    The nature of intrinsic and impurity point defects in lead zirconate titanate (PZT) ceramics has been explored. Using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) methods, several impurity sites have been identified in the materials, including the Fe(3+)-oxygen vacancy (VO) complex and Pb ions. Both of these centers are incorporated into the PZT lattice. The Fe(3+) –VО paramagnetic complex serves as a sensitive probe of the local crystal field in the ceramic; the symmetry of this defect roughly correlates with PZT phase diagram as the composition is varied from PbTiO3 to PbZrO3. NMR spectra (207)Pb in PbTiO3, PbZrO3, and PZT with iron content from 0 to 0.4 wt% showed that increasing the iron concentration leads to a distortion of the crystal structure and to improvement of the electrophysical parameters of the piezoceramics. This is due to the formation of a phase which has a higher symmetry, but at high concentrations of iron (>0.4 wt%), it leads to sharp degradation of electrophysical parameters.

  18. Examining Public Perceptions about Lead in School Drinking Water: A Mixed-Methods Analysis of Twitter Response to an Environmental Health Hazard.

    Science.gov (United States)

    Ekenga, Christine C; McElwain, Cora-Ann; Sprague, Nadav

    2018-01-20

    Exposure to lead has long been a community health concern in St. Louis, Missouri. The objective of this study was to examine public response to reports of elevated lead levels in school drinking water in St. Louis, Missouri via Twitter, a microblogging platform with over 320 million active users. We used a mixed-methods design to examine Twitter user status updates, known as "tweets," from 18 August to 31 December 2016. The number of tweets each day was recorded, and Twitter users were classified into five user types (General Public, Journalist/News, Health Professional/Academic, Politician/Government Official, and Non-Governmental Organization). A total of 492 tweets were identified during the study period. The majority of discourse on Twitter occurred during the two-week period after initial media reports and was driven by members of the General Public. Thematic analysis of tweets revealed four themes: Information Sharing, Health Concerns, Sociodemographic Disparities, and Outrage. Twitter users characterized lead in school drinking water as an issue of environmental inequity. The findings of this study provide evidence that social media platforms can be utilized as valuable tools for public health researchers and practitioners to gauge public sentiment about environmental health issues, identify emerging community concerns, and inform future communication and research strategies regarding environmental health hazards.

  19. Factors affecting the simultaneous determination of copper, lead, cadmium, and zinc concentrations in human head hair using differential pulse anodic stripping voltammetry method

    International Nuclear Information System (INIS)

    Wandiga, S.O.; Jumba, I.O.

    1982-01-01

    Conditions of analysis of copper, lead, cadmium and zinc content in human hair using differential pulse anodic stripping voltammetry (DPASV) and hanging mercury drop electrode (HMDE) have been established. Sample digestion using using the mixture HCI; H 2 O 2 ;HNO 3 in the ratio 2:1:40 by volume gave the best wet-ashing procedure. The peak currents and peak potentials of zinc, cadmium and lead, copper were maximum at pH 6-7 and 1-3 respectively, when excess H 2 O 2 was eliminated with subsequent addition of hydroxyamine hydrochloride. Matrix concentration effects were minimized by digesting weights not exceeding 50 mg per sample. The effect of selenium (IV) was negligible and was ignored. The detection limit of 0.0036 ng/cm 3 for Cd + 2 was obtained while the values for zinc, lead and copper were 0.0230, 0.0287 and 0.0269 ng/cm 3 respectively at the 95% confidence limit. The observed DPASV condition of analysis of these metals are useful for routine determination of the metals in human hair and should complement the conventional flame absorption spectrophotometry method. (author)

  20. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  1. Use of an automated X-ray fluorescence method in the study of pollution due to lead and bromine from automobiles

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Gros, R.; Patti, F.; Goujon Beauvivier, M. de; Laporte, J.

    1976-01-01

    The authors first describe an automated method for determining, by X-ray fluorescence, mineral pollutants present in the air in particulate form. The fluorescence spectrometer employed is a wavelength-dispersive commercial model. It is connected to a recording unit by means of which one can obtain the spectrum on punched tape; the spectrum is then analysed by computer. The calibration method and the performance characteristics are described. In the second part of the paper, the results are presented of monthly measurements of lead and bromine in the air, performed over a period of several years at four stations in different types of location. The mean Pb/Br ratio is not the same for all the stations. A seasonal variation of the ratio shows up clearly in the Paris region. (author)

  2. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also disting...

  3. Lead Poison Detection

    Science.gov (United States)

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  4. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  5. The optimum lead thickness for lead-activation detectors

    International Nuclear Information System (INIS)

    Si Fenni; Hu Qingyuan

    2009-01-01

    The optimum lead thickness for lead-activation detectors has been studied in this paper. First existence of the optimum lead thickness is explained theoretically. Then the optimum lead thickness is obtained by two methods, MCNP5 calculation and mathematical estimation. At last factors which affect the optimum lead thickness are discussed. It turns out that the optimum lead thickness is irrelevant to incident neutron energies. It is recommended 2.5 cm generally.

  6. Cochrane Rapid Reviews Methods Group to play a leading role in guiding the production of informed high-quality, timely research evidence syntheses.

    Science.gov (United States)

    Garritty, Chantelle; Stevens, Adrienne; Gartlehner, Gerald; King, Valerie; Kamel, Chris

    2016-10-28

    Policymakers and healthcare stakeholders are increasingly seeking evidence to inform the policymaking process, and often use existing or commissioned systematic reviews to inform decisions. However, the methodologies that make systematic reviews authoritative take time, typically 1 to 2 years to complete. Outside the traditional SR timeline, "rapid reviews" have emerged as an efficient tool to get evidence to decision-makers more quickly. However, the use of rapid reviews does present challenges. To date, there has been limited published empirical information about this approach to compiling evidence. Thus, it remains a poorly understood and ill-defined set of diverse methodologies with various labels. In recent years, the need to further explore rapid review methods, characteristics, and their use has been recognized by a growing network of healthcare researchers, policymakers, and organizations, several with ties to Cochrane, which is recognized as representing an international gold standard for high-quality, systematic reviews. In this commentary, we introduce the newly established Cochrane Rapid Reviews Methods Group developed to play a leading role in guiding the production of rapid reviews given they are increasingly employed as a research synthesis tool to support timely evidence-informed decision-making. We discuss how the group was formed and outline the group's structure and remit. We also discuss the need to establish a more robust evidence base for rapid reviews in the published literature, and the importance of promoting registration of rapid review protocols in an effort to promote efficiency and transparency in research. As with standard systematic reviews, the core principles of evidence-based synthesis should apply to rapid reviews in order to minimize bias to the extent possible. The Cochrane Rapid Reviews Methods Group will serve to establish a network of rapid review stakeholders and provide a forum for discussion and training. By facilitating

  7. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array

    Science.gov (United States)

    Zhou, Li

    2018-01-01

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method. PMID:29466310

  8. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array.

    Science.gov (United States)

    Yan, Gang; Zhou, Li

    2018-02-21

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method.

  9. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2012-01-01

    Full Text Available Cloud point extraction (CPE has been used for the preconcentration and simultaneous determination of cobalt (Co and lead (Pb in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114, temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS. The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

  10. Secondary lead production

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, R.G.

    1990-10-16

    This invention is concerned with the efficient recovery of soft lead from the paste component of used automobile lead-acid storage batteries. According to the invention, a scrap which contains lead oxide, lead sulfate, and antimony in an oxidized state is processed in the following steps to recover lead. A refractory lined reaction vessel is continuously charged with the scrap, along with a reductant effective for reducing lead oxide. The charged material is melted and agitated by means of a submerged lance at 900-1150{degree}C whereby some of the lead oxide of the scrap is reduced to form molten lead. A slag layer is then formed above the molten lead, and an amount of lead oxide is maintained in the slag layer. The molten lead, now containing under 0.5 wt % of antimony, is removed, and the antimony oxide in the scrap is concentrated as oxide in the slag layer. Preferred embodiments of the invention result in the production, in a single step, of a soft lead substantially free of antimony. The slag may be subsequently treated to reduce the antimony oxide and produce a valuable antimony-lead product. Further advantages of the process are that a wet battery paste may be used as the feed without prior drying, and the process can be conducted at a temperature 100-150{degree}C lower than in previously known methods. In addition, a smaller reactor can be employed which reduces both capital cost and fuel costs. The process of the invention is illustrated by descriptions of pilot plant tests. 1 fig.

  11. Ultrasonic-energy enhance the ionic liquid-based dual microextraction to preconcentrate the lead in ground and stored rain water samples as compared to conventional shaking method.

    Science.gov (United States)

    Nizamani, Sooraj; Kazi, Tasneem G; Afridi, Hassan I

    2018-01-01

    An efficient preconcentration technique based on ultrasonic-assisted ionic liquid-based dual microextraction (UA-ILDµE) method has been developed to preconcentrate the lead (Pb +2 ) in ground and stored rain water. In the current proposed method, Pb +2 was complexed with a chelating agent (dithizone), whereas an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was used for extraction purpose. The ultrasonic irradiation and electrical shaking system were applied to enhance the dispersion and extraction of Pb +2 complex in aqueous samples. For second phase, dual microextraction (DµE phase), the enriched Pb +2 complex in ionic liquid, extracted back into the acidic aqueous solution and finally determined by flame atomic absorption spectrometry. Some major analytical parameters that influenced the extraction efficiency of developed method, such as pH, concentration of ligand, volume of ionic liquid and samples, time of shaking in thermostatic electrical shaker and ultrasonic bath, effect of back extracting HNO 3 volume, matrix effect, centrifugation time and rate were optimized. At the sample volume of 25mL, the calculated preconcentration factor was 62.2. The limit of detection of proposed procedure for Pb +2 ions was found to be 0.54μgL -1 . The validation of developed method was performed by the analysis of certified sample of water SRM 1643e and standard addition method in a real water sample. The extraction recovery of Pb +2 was enhanced≥2% with shaking time of 80s in ultrasonic bath as compared to used thermostatic electrical shaker, where for optimum recovery up to 10min was required. The developed procedure was successfully used for the enrichment of Pb +2 in ground and stored rain water (surface water) samples of an endemic region of Pakistan. The resulted data indicated that the ground water samples were highly contaminated with Pb +2 , while some of the surface water samples were also have higher values of Pb +2 than permissible limit of

  12. The comparative study of contents of zinc and lead in ore samples of Namtu-Bawdwin Mine by wet analysis, X-ray fluorescence and X-ray diffraction methods

    Energy Technology Data Exchange (ETDEWEB)

    Kyaw-Soe,

    1990-05-01

    Lead-zinc ores taken from Namtu-Bawdwin area had been analyzed by wet processes in the Department of Chemistry, 1984. These ore samples have been analyzed by energy dispersive X-ray fluorescence method in the Department of Physics and X-ray diffraction method is also used to determine elements of lead and zinc compounds in these ore samples in the University`s Research Centre. In brief, we study comparatively the contents of lead and zinc and their compounds using the methods of wet processes, X-ray fluorescence and X-ray diffraction. (author).

  13. Determination of lead content in drilling fueled soil using laser induced spectral analysis and its cross validation using ICP/OES method.

    Science.gov (United States)

    Rehan, I; Gondal, M A; Rehan, K

    2018-05-15

    A detection system based on Laser Induced Breakdown Spectroscopy (LIBS) was designed, optimized, and successfully employed for the estimation of lead (Pb) content in drilling fueled soil (DFS) collected from oil field drilling areas in Pakistan. The concentration of Pb was evaluated by the standard calibration curve method as well as by using an approach based on the integrated intensity of strongest emission of an element of interest. Remarkably, our investigation clearly demonstrated that the concentration of Pb in drilling fueled soil collected at the exact drilling site was greater than the safe permissible limits. Furthermore, the Pb concentration was observed to decline with increasing distance away from the specific drilling point. Analytical determinations were carried out under the assumptions that laser generated plasma was optically thin and in local thermodynamic equilibrium (LTE). In order to improve the sensitivity of our LIBS detection system, various parametric dependence studies were performed. To further validate the precision of our LIBS results, the concentration of Pb present in the acquired samples were also quantified via a standard analytical tool like inductively coupled plasma/optical emission spectroscopy (ICP/OES). Both results were in excellent agreement, implying remarkable reliability for the LIBS data. Furthermore, the Limit of detection (LOD) of our LIBS system for Pb was estimated to be 125.14 mg L -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Identification and Decay Studies of New, Neutron-Rich Isotopes of Bismuth, Lead and Thallium by means of a Pulsed Release Element Selective Method

    CERN Multimedia

    Mills, A; Kugler, E; Van duppen, P L E; Lettry, J

    2002-01-01

    % IS354 \\\\ \\\\ It is proposed to produce, identify and investigate at ISOLDE new, neutron-rich isotopes of bismuth, lead and thallium at the mass numbers A=215 to A=218. A recently tested operation mode of the PS Booster-ISOLDE complex, taking an advantage of the unique pulsed proton beam structure, will be used together with a ThC target in order to increase the selectivity. The decay properties of new nuclides will be studied by means of $\\beta$-, $\\gamma$- and X- ray spectroscopy methods. The expected information on the $\\beta$-half-lives and excited states will be used for testing and developing the nuclear structure models ``south-east'' of $^{208}$Pb, and will provide input data for the description of the r-process path at very heavy nuclei. The proposed study of the yields and the decay properties of those heavy nuclei produced in the spallation of $^{232}$Th by a 1~GeV proton beam contributes also the data necessary for the simulations of a hybrid accelerator-reactor system.

  15. The effect of thai glutinous rice starch on the synthesis of lead zirconate (PbZrO3) nanofibers via the electrospinning method.

    Science.gov (United States)

    Nawanil, Chanisa; Vittayakorn, Wanwilai; Muanghua, Rangson; Niemcharoen, Surasak; Prachayawarakorn, Jutarat; Vittayakorn, Naratip

    2013-05-01

    This study synthesized blended lead zirconate (PbZrO3;PZ)/poly(ethylene oxide)(PEO)/Glutinous rice starch (GRS) nanofibers by the electrospinning method. A number of parameters such as the ratio between PEO and GRS and calcination temperature have been studied. The as-spun PZ/PEO/GRS composite and PZ fibers were characterized by TG-DTA, X-ray diffraction, FT-IR and SEM, respectively. SEM results showed that smooth and continuous fibers were obtained at the volume ratio of 10:2:1, PZ/PEO/GRS. After calcination of the as-spun PZ/PEO/GRS composite nanofibers at 650 degrees C for 4 h, PZ nanofibers with perovskite structure were obtained successfully. The fibers had a uniform and smooth surface without grain boundaries. However, when the calcination temperature increased to 750 degrees C and 850 degrees C, the fiber represented a necklace-like structure with grain boundaries arranged by grain to grain unit cell clusters.

  16. Remediation of lead contaminated soil

    International Nuclear Information System (INIS)

    Urban, W.; Krishnamurthy, S.

    1992-01-01

    Lead contaminated soil in urban area is of major concern because of the potential health risk to children. Many studies have established a direct correlation between lead in soil and elevated blood lead levels in children. In Minneapolis, Minnesota, Mielke et al. (1983) reported that 50% of the Hmong children with lead poisioning were in areas where soil lead levels were between 500 and 1000 micrograms per gram (ug/g), and 40% of the children suffering from lead poisioning lived in areas where soil lead levels exceeded 1000 ug/g. In urban areas, lead pollution in soil has come from many different sources. The sources include lead paint, lead batteries and automobile exhaust. Olson and Skogerbee (1975) found the following lead compounds in soils where the primary source of pollution was from automobiles: lead sulfate, lead oxide, lead dioxide, lead sulfide, and metallic lead. The primary form of lead found was lead sulfate. Lead sulfate, lead tetraoxide, white lead, and other forms of lead have been used in the manufacture of paints for houses. At present, two remediation techniques, solidification and Bureau of Mines fluosilicic acid leaching, are available for lead-contaminated sites. The objective of the present investigation at the Risk Reduction Engineering Laboratory (RREL), Edison, was to try to solubilize the lead species by appropriate reagents and then recover the contaminants by precipitation as lead sulfate, using environmentally acceptable methods. The apparatus used for mixing was a LabMaster mixer, with variable speed and high-shear impeller. Previous work had used nitric acid for dissolving metallic lead. Owing to the environmental concerns, it was decided to use acetic acid in the presence of oxygen. The theoretical justification for this approach is the favorable redox potential for the reaction between metallic lead, acetic acid, and gaseous oxygen

  17. Lead user projects in practice

    DEFF Research Database (Denmark)

    Brem, Alexander; Gutstein, Adele

    2018-01-01

    Earlier research on the lead user method is focused on individual case studies and how the method was applied in a specific context. In this paper, we take a broader approach, analyzing a sample of 24 lead user projects, which included working with 188 lead users. These projects were analyzed...

  18. Involving Lead Users in Innovation

    DEFF Research Database (Denmark)

    Brem, Alexander; Bilgram, Volker; Gutstein, Adele

    2018-01-01

    Research on the lead user method has been conducted for more than thirty years and has shown that the method is more likely to generate breakthrough innovation than traditional market research tools. Based on a systematic literature review, this paper shows a detailed view on the broad variety...... of research on lead user characteristics, lead user processes, lead user identification and application, and success factors. The main challenge of the lead user method as identified in literature is the resource issue regarding time, manpower, and costs. Also, internal acceptance and the processing...... of the method have been spotted in literature, as well as the intellectual property protection issue. From the starting point of the initial lead user method process introduced by Lüthje and Herstatt (2004), results are integrated into a revisited view on the lead user method process. In addition, concrete...

  19. SIGNIFICANCE OF TARGETED EXOME SEQUENCING AND METHODS OF DATA ANALYSIS IN THE DIAGNOSIS OF GENETIC DISORDERS LEADING TO THE DEVELOPMENT OF EPILEPTIC ENCEPHALOPATHY

    Directory of Open Access Journals (Sweden)

    Tatyana Victorovna Kozhanova

    2017-08-01

    Full Text Available Epilepsy is the most common serious neurological disorder, and there is a genetic basis in almost 50% of people with epilepsy. The diagnosis of genetic epilepsies makes to estimate reasons of seizures in the patient. Last decade has shown tremendous growth in gene sequencing technologies, which have made genetic tests available. The aim is to show significance of targeted exome sequencing and methods of data analysis in the diagnosis of hereditary syndromes leading to the development of epileptic encephalopathy. We examined 27 patients with с early EE (resistant to antiepileptic drugs, psychomotor and speech development delay in the psycho-neurological department. Targeted exome sequencing was performed for patients without a previously identified molecular diagnosis using 454 Sequencing GS Junior sequencer (Roche and IlluminaNextSeq 500 platform. As a result of the analysis, specific epilepsy genetic variants were diagnosed in 27 patients. The greatest number of cases was due to mutations in the SCN1A gene (7/27. The structure of mutations for other genes (mutations with a minor allele frequency of less than 0,5% are presented: ALDH7A1 (n=1, CACNA1C (n=1, CDKL5 (n=1, CNTNAP2 (n=2, DLGAP2 (n=2, DOCK7 (n=2, GRIN2B (n=2, HCN1 (n=1, NRXN1 (n=3, PCDH19 (n=1, RNASEH2B (n=2, SLC2A1 (n=1, UBE3A (n=1. The use of the exome sequencing in the genetic practice allows to significantly improve the effectiveness of medical genetic counseling, as it made possible to diagnose certain variants of genetically heterogeneous groups of diseases with similar of clinical manifestations.

  20. Leading healthcare in complexity.

    Science.gov (United States)

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  1. Gas cooled leads

    International Nuclear Information System (INIS)

    Shutt, R.P.; Rehak, M.L.; Hornik, K.E.

    1993-01-01

    The intent of this paper is to cover as completely as possible and in sufficient detail the topics relevant to lead design. The first part identifies the problems associated with lead design, states the mathematical formulation, and shows the results of numerical and analytical solutions. The second part presents the results of a parametric study whose object is to determine the best choice for cooling method, material, and geometry. These findings axe applied in a third part to the design of high-current leads whose end temperatures are determined from the surrounding equipment. It is found that cooling method or improved heat transfer are not critical once good heat exchange is established. The range 5 5 but extends over a large of values. Mass flow needed to prevent thermal runaway varies linearly with current above a given threshold. Below that value, the mass flow is constant with current. Transient analysis shows no evidence of hysteresis. If cooling is interrupted, the mass flow needed to restore the lead to its initially cooled state grows exponentially with the time that the lead was left without cooling

  2. A study on lead equivalent

    International Nuclear Information System (INIS)

    Lin Guanxin

    1991-01-01

    A study on the rules in which the lead equivalent of lead glass changes with the energy of X rays or γ ray is described. The reason of this change is discussed and a new testing method of lead equivalent is suggested

  3. Using the methods of radiospectroscopy (EPR, NMR) to study the nature of the defect structure of solid solutions based on lead zirconate titanate (PZT)

    Czech Academy of Sciences Publication Activity Database

    Bykov, I. P.; Zagorodniy, A.Y.; Yurchenko, L.P.; Korduban, A.M.; Nejezchleb, K.; Trachevsky, V.V.; Dimza, V.; Jastrabík, Lubomír; Dejneka, Alexandr

    2014-01-01

    Roč. 61, č. 8 (2014), 1379-1385 ISSN 0885-3010 R&D Projects: GA TA ČR TA01010517; GA ČR GAP108/12/1941 Institutional support: RVO:68378271 Keywords : lead zirconate titanate ( PZT ) * EPR * NMR * XPS spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.512, year: 2014

  4. Analysis of accidents leading to amputations associated with operating with press machines, using Ishikawa and SCAT Combined method in a car manufacturing company

    Directory of Open Access Journals (Sweden)

    J. Nematolahi

    2015-12-01

      Conclusion: According to results, the main interfce causes of accidents leading to amputation due to operating with press machines is hurry at work because of increased production volume particularly by contractor companies. Furthermore, non-dynamic HSE system accompanied by ineffective supervision of personnel’s unsafe acts by the first layers of management are recognized as the basic causes of such accidents.

  5. Common ECG Lead Placement Errors. Part I: Limb Lead Reversals

    Directory of Open Access Journals (Sweden)

    Allison V. Rosen

    2015-10-01

    Full Text Available Background: Electrocardiography (ECG is a very useful diagnostic tool. However, errors in placement of ECG leads can create artifacts, mimic pathologies, and hinder proper ECG interpretation. It is important for members of the health care team to be able to recognize the common patterns resulting from lead placement errors. Methods: 12-lead ECGs were recorded in a single male healthy subject in his mid 20s. Six different limb lead reversals were compared to ECG recordings from correct lead placement. Results: Classic ECG patterns were observed when leads were reversed. Methods of discriminating these ECG patterns from true pathologic findings were described. Conclusion: Correct recording and interpretation of ECGs is key to providing optimal patient care. It is therefore crucial to be able to recognize common ECG patterns that are indicative of lead reversals.

  6. The determination of the pore distribution and the consideration of methods leading to the prediction of retention characteristics of membrane filters

    International Nuclear Information System (INIS)

    Badenhop, C.T.

    1983-01-01

    Presented here is a method for the determination of the pore size distribution of a membrane microfilter. Existing test metods are either cumbersome, as is the Erbe method; time consuming, as is the evaluation of electron microscope photographs; do not really measure the pore distribution, as the mercury intrusion method; or do not satisfactorily evaluate the large pore range of the filter, as is the case with the automated ASTM method. The new method described in this paper is based upon the solution of the integral flow equation for the pore distribution function. A computer program evaluates the flow test data and calculates the numerical pore distribution, water-flow distribution, air-flow distribution and capillary area distribution, as a function of the pore size. (orig./RW)

  7. Depuration Study of Heavy Metal Lead (Pb) and Copper (Cu) in Green Mussels Perna viridis through Continues-discontinues and Acid Extraction Methods

    Science.gov (United States)

    Budiawan; Bakri, Ridla; Cahaya Dani, Intan; Handayani, Sri; Ade Kurnia Putri, Rizki; Tamala, Riska

    2018-01-01

    Green mussel or Perna viridis is filter feeder, which is very susceptible to heavy metals. It takes an effort to release heavy metal contents on the green shell, one of method that can be used to release heavy metal from green shell is depuration proccess. In this research, the depuration process was conducted by continues method of depuration, discontinues method by using various kind of water and acid extraction. The optimum time of continues depuration method is 1.5 hours, with circulation speed 250 L/h and result of Pb metal content decreased is equal to 30.048% and 29.748% for Cu. In the discontinues method, the optimum result was reached at 100oC by using PAM water as the media at 3 h immersion period with decrease of Pb metal content 35.001% and Cu metal content 39.015%. In the acid extraction method, the optimum condition was achieved by 11% acetic acid solvent with decreasing of Pb and Cu levels are 88.224% and 76.298%. For the determination of protein content, the decrease of protein content obtained by treatment with 11% acetic acid extract showed decrease of protein content 36.656% with Kjeldahl method.

  8. Determination of point isotropic buildup factors of gamma rays including incoherent and coherent scattering for aluminum, iron, lead, and water by discrete ordinates method

    International Nuclear Information System (INIS)

    Kitsos, S.; Assad, A.; Diop, C.M.; Nimal, J.C.

    1994-01-01

    Exposure and energy absorption buildup factors for aluminum, iron, lead, and water are calculated by the SNID discrete ordinates code for an isotropic point source in a homogeneous medium. The calculation of the buildup factors takes into account the effects of both bound-electron Compton (incoherent) and coherent (Rayleigh) scattering. A comparison with buildup factors from the literature shows that these two effects greatly increase the buildup factors for energies below a few hundred kilo-electron-volts, and thus the new results are improved relative to the experiment. This greater accuracy is due to the increase in the linear attenuation coefficient, which leads to the calculation of the buildup factors for a mean free path with a smaller shield thickness. On the other hand, for the same shield thickness, exposure increases when only incoherent scattering is included and decreases when only coherent scattering is included, so that the exposure finally decreases when both effects are included. Great care must also be taken when checking the approximations for gamma-ray deep-penetration transport calculations, as well as for the cross-section treatment and origin

  9. Development of a lead x-ray compensation method in simultaneous Tl-201 SPECT ampersand Tc-99m TCT using a flood source

    International Nuclear Information System (INIS)

    Motomura, N.; Ichihara, T.; Hasegawa, H.

    1996-01-01

    Several studies have been reported about simultaneous single photon emission computed tomography (SPECT) and transmission computed tomography (TCT) to obtain the attenuation map needed for non-uniform attenuation compensation methods. To perform SPECT/TCT scans, there are some TCT source and collimator configurations. In the TCT system utilizing a flood source and parallel beam collimator, the advantages are a large field-of-view without truncation, no lateral motion of the source as in the case for the scanning line method, and no fixed source position for the method with a convergent collimator. However the disadvantages of the flood source method are significant scatter component, and blockage of the detector with the flood source attached in multiple-head SPECT systems

  10. Lead user projects in practice

    DEFF Research Database (Denmark)

    Brem, Alexander; Gutstein, Adele

    2018-01-01

    Earlier research on the lead user method is focused on individual case studies and how the method was applied in a specific context. In this paper, we take a broader approach, analyzing a sample of 24 lead user projects, which included working with 188 lead users. These projects were analyzed....... Moreover, crowdsourcing contests and netnography proved to be of significant value for the need, trend, and lead user identification phases. This paper concludes by discussing theoretical and practical implications, the limitations of this study, and recommendations for future studies....

  11. Review and research analysis of computational target methods using BioRuby and in silico screening of herbal lead compounds against pancreatic cancer using R programming.

    Science.gov (United States)

    Jayadeepa, R M; Ray, Ankita; Naik, Dhaval; Sanyal, Debendra Nath; Shah, Disha

    2014-01-01

    Plants and their natural components sophisticated with the cornerstone of traditional conventional medicinal system throughout the globe for many years and extend to furnish mankind with latest remedies. Natural Products act as lead molecules for the synthesis of various potent drugs. In the current research a study is conducted on herbal small molecule and their potential binding chemical affinity to the effect or molecules of major diseases such as pancreatic cancer. Clinical studies demonstrate correlation between Cyclin- Dependent Kinase 4 (CDK4) and malignant progression of Pancreatic Cancer. Using Bioruby Gem's we were able to analyze better characteristics of the target protein. VegaZZ and NAMD were used to minimize the energy of the target protein. Therefore identification of effective, well- tolerated targets was analyzed. Further the target protein was subjected to docking with the anti cancer inhibitors which represents a rational chemo preventive strategy using AutoDock Vina. Later using the dock score top ranked phytochemicals were analyzed for Toxicity Analysis. Using the BioRuby gem we were able to measure the distance between the amino acid. Various R scripting libraries were used to hunt the best leads, as in this case the phytochemicals. Phytochemicals such as Wedelolactones and Catechin were analyzed computationally. This study has presented the various effects of naturally occurring anti pancreatic cancer compounds Catechin, Wedelolactones that inhibits Cyclin Dependent Kinase 4. The study results reveal that compounds use less binding energy to CDK4 and inhibit its activity. Future investigation of other various wet lab studies such as cell line studies will confirm results of these two herbal chemical formulations potential ones for treating Pancreatic Cancer.

  12. A novel method applied in determination and assessment of trace amount of lead and cadmium in rice from four provinces, China.

    Science.gov (United States)

    Li, Shan; Wang, Mei; Yang, Bingyi; Zhong, Yizhou; Feng, Le

    2014-01-01

    Heavy metal contamination of soils or water can lead to excessive lead (Pb) and cadmium (Cd) levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS). The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9.0 and 40°C. Analytes were quantitatively extracted to a surfactant-rich phase (Triton X-45) after centrifugation and analyzed by GFAAS. The effects of experimental conditions, including pH, concentration of reagents, and equilibration time and temperature, on cloud point extraction were optimized efficiently using Plackett-Burman and Box-Behnken experimental designs. Under the optimum conditions, good linearity was observed in the concentration ranges of 0.5-5 µg/L for Pb and 0.05-0.50 µg/L for Cd. The limits of detection were 0.043 µg/L for Pb with a concentration factor of 24.2 in a 10 mL sample and 0.018 µg/L for Cd with a concentration factor of 18.4 in a 10 mL sample. Twenty rice samples from four provinces were analyzed successfully, and the mean levels of Pb and Cd in the rice were all below their maximum allowable concentrations in China. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb and Cd mean daily intake through rice consumption were 0.84 µg/kg bw/day and 0.40 µg/kg bw/day, which were lower than the tolerable daily intakes.

  13. Lead isotope ratios in artists' lead white: a progress report

    Energy Technology Data Exchange (ETDEWEB)

    Keisch, B; Callahan, R C [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

    1976-07-01

    The lead isotope ratios in over four hundred samples of lead white have been determined. The samples represent various geographical sources and dates from the thirteenth century to the present. A new method for organizing this large volume of data is described which helps with the visualization of temporal and geographic patterns. A number of interesting relationships between lead isotope ratio and date or source are shown to exist. Some examples of successful applications of this methodology are described.

  14. Lead isotope ratios in artists' lead white: a progress report

    International Nuclear Information System (INIS)

    Keisch, B.; Callahan, R.C.

    1976-01-01

    The lead isotope ratios in over four hundred samples of lead white have been determined. The samples represent various geographical sources and dates from the thirteenth century to the present. A new method for organizing this large volume of data is described which helps with the visualization of temporal and geographic patterns. A number of interesting relationships between lead isotope ratio and date or source are shown to exist. Some examples of successful applications of this methodology are described. (author)

  15. Lead levels - blood

    Science.gov (United States)

    Blood lead levels ... is used to screen people at risk for lead poisoning. This may include industrial workers and children ... also used to measure how well treatment for lead poisoning is working. Lead is common in the ...

  16. Lead Poisoning Prevention Tips

    Science.gov (United States)

    ... or removed safely. How are children exposed to lead? Lead-based paint and lead contaminated dust are ... What can be done to prevent exposure to lead? It is important to determine the construction year ...

  17. The Method of Loci as a Mnemonic Device to Facilitate Learning in Endocrinology Leads to Improvement in Student Performance as Measured by Assessments

    Science.gov (United States)

    Qureshi, Ayisha; Rizvi, Farwa; Syed, Anjum; Shahid, Aqueel; Manzoor, Hana

    2014-01-01

    Cognitive psychology has demonstrated that the way knowledge is structured in memory determines the ability to retain, recall, and use it to solve problems. The method of loci (MOL) is a mnemonic device that relies on spatial relationships between "loci" (e.g., locations on a familiar route or rooms in a familiar building) to arrange and…

  18. What is lead-based paint?

    International Nuclear Information System (INIS)

    Vernon, L.S.

    1994-01-01

    The number of variety of lead-abatement regulations and requirements make it difficult and confusing to identify and properly respond to dangerous levels of lead in every situation. Definitions of ''lead-based paint'' and three test methods for lead detection are described to help determine when and how to test for the presence of lead

  19. Effect of deposition temperature on the structural, morphological and optical band gap of lead selenide thin films synthesized by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Hone, Fekadu Gashaw, E-mail: fekeye@gmail.com [Hawassa University, Department of Physics, Hawassa (Ethiopia); Ampong, Francis Kofi [Kwame Nkrumah University of Science and Technology, Department of Physics, Kumasi (Ghana)

    2016-11-01

    Lead selenide (PbSe) nanocrystalline thin films have been deposited on silica glass substrates by the chemical bath deposition technique. The samples were deposited at the bath temperatures of 60, 75 and 90 °C respectively and characterized by a variety of techniques. The XRD results revealed that the PbSe thin film deposited at 60 °C was amorphous in nature. Films deposited at higher temperatures exhibited sharp and intense diffraction peaks, indicating an improvement in crystallinety. The deposition temperature also had a strong influence on the preferred orientation of the crystallites as well as other structural parameters such as microstrain and dislocation density. From the SEM study it was observed that film deposited at 90 °C had well defined crystallites, uniformly distributed over the entire surface of the substrate. The EDAX study confirmed that the samples deposited at the higher temperature had a better stoichiometric ratio. The optical band gap varied from 2.26 eV to 1.13 eV with increasing deposition temperature. - Highlights: • The crystallinety of the films improved as the deposition temperature increased. • The deposition temperature strongly influenced the preferred orientations. • Microstrain and dislocation density are decreased linearly with deposition temperature. • Band gap decreased from 2.26 eV to 1.13 eV as the deposition temperature increased.

  20. Large-capacity current leads

    International Nuclear Information System (INIS)

    Ballarino, A.

    2008-01-01

    Feeding superconducting magnets with reliable low-loss devices is a key issue for any cryo-electrical system. Conventional or HTS current leads can be used, and cooling methods, materials, and geometries can be chosen to optimize the thermo-electrical performance of the system. The LHC magnets are powered via more than 3000 current leads transporting altogether about 3 MA of current. With thousands of leads, the LHC lead project represents today the largest project of its kind ever undertaken. Following a review of the LHC lead project, an overview of the choices that can be made for the optimization of large capacity current leads is presented. Examples are given of other leads for large scale magnet systems for which the use of HTS is being envisaged

  1. Validation of a method to quantify chromium, cadmium, manganese, nickel and lead in human whole blood, urine, saliva and hair samples by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Olmedo, P.; Pla, A.; Hernandez, A.F.; Lopez-Guarnido, O.; Rodrigo, L.; Gil, F.

    2010-01-01

    For biological monitoring of heavy metal exposure in occupational toxicology, usually whole blood and urine samples are the most widely used and accepted matrix to assess internal xenobiotic exposure. Hair samples and saliva are also of interest in occupational and environmental health surveys but procedures for the determination of metals in saliva and hair are very scarce and to our knowledge there is no validation of a method to quantify Cr, Cd, Mn, Ni and Pb in four different human biological materials (whole blood, urine, saliva and axilary hair) by electrothermal atomization atomic absorption spectrometry (ETAAS). In the present study, quantification methods for the determination of Cr, Cd, Mn, Ni and Pb in whole blood, urine, saliva and axilary hair were validated according to the EU common standards. Pyrolisis and atomization temperatures have been determined. The main parameters evaluated were: detection and quantification limits, linearity range, repeatability, reproducibility, recovery and uncertainty. Accuracy of the methods was tested with the whole blood, urine and hair certified reference materials and recoveries of the spiked samples were acceptable ranged from 96.3 to 107.8%.

  2. Validation of a method to quantify chromium, cadmium, manganese, nickel and lead in human whole blood, urine, saliva and hair samples by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Olmedo, P.; Pla, A.; Hernandez, A.F.; Lopez-Guarnido, O.; Rodrigo, L. [Department of Legal Medicine and Toxicology, University of Granada, School of Medicine (Spain); Gil, F., E-mail: fgil@ugr.es [Department of Legal Medicine and Toxicology, University of Granada, School of Medicine (Spain)

    2010-02-05

    For biological monitoring of heavy metal exposure in occupational toxicology, usually whole blood and urine samples are the most widely used and accepted matrix to assess internal xenobiotic exposure. Hair samples and saliva are also of interest in occupational and environmental health surveys but procedures for the determination of metals in saliva and hair are very scarce and to our knowledge there is no validation of a method to quantify Cr, Cd, Mn, Ni and Pb in four different human biological materials (whole blood, urine, saliva and axilary hair) by electrothermal atomization atomic absorption spectrometry (ETAAS). In the present study, quantification methods for the determination of Cr, Cd, Mn, Ni and Pb in whole blood, urine, saliva and axilary hair were validated according to the EU common standards. Pyrolisis and atomization temperatures have been determined. The main parameters evaluated were: detection and quantification limits, linearity range, repeatability, reproducibility, recovery and uncertainty. Accuracy of the methods was tested with the whole blood, urine and hair certified reference materials and recoveries of the spiked samples were acceptable ranged from 96.3 to 107.8%.

  3. Review of Leading Approaches for Mitigating Hypersonic Vehicle Communications Blackout and a Method of Ceramic Particulate Injection Via Cathode Spot Arcs for Blackout Mitigation

    Science.gov (United States)

    Gillman, Eric D.; Foster, John E.; Blankson, Isaiah M.

    2010-01-01

    Vehicles flying at hypersonic velocities within the atmosphere become enveloped in a "plasma sheath" that prevents radio communication, telemetry, and most importantly, GPS signal reception for navigation. This radio "blackout" period has been a problem since the dawn of the manned space program and was an especially significant hindrance during the days of the Apollo missions. An appropriate mitigation method must allow for spacecraft to ground control and ground control to spacecraft communications through the reentry plasma sheath. Many mitigation techniques have been proposed, including but not limited to, aerodynamic shaping, magnetic windows, and liquid injection. The research performed on these mitigation techniques over the years will be reviewed and summarized, along with the advantages and obstacles that each technique will need to overcome to be practically implemented. A unique approach for mitigating the blackout communications problem is presented herein along with research results associated with this method. The novel method involves the injection of ceramic metal-oxide particulate into a simulated reentry plasma to quench the reentry plasma. Injection of the solid ceramic particulates is achieved by entrainment within induced, energetic cathode spot flows.

  4. Facile and Scalable Fabrication of Highly Efficient Lead Iodide Perovskite Thin-Film Solar Cells in Air Using Gas Pump Method.

    Science.gov (United States)

    Ding, Bin; Gao, Lili; Liang, Lusheng; Chu, Qianqian; Song, Xiaoxuan; Li, Yan; Yang, Guanjun; Fan, Bin; Wang, Mingkui; Li, Chengxin; Li, Changjiu

    2016-08-10

    Control of the perovskite film formation process to produce high-quality organic-inorganic metal halide perovskite thin films with uniform morphology, high surface coverage, and minimum pinholes is of great importance to highly efficient solar cells. Herein, we report on large-area light-absorbing perovskite films fabrication with a new facile and scalable gas pump method. By decreasing the total pressure in the evaporation environment, the gas pump method can significantly enhance the solvent evaporation rate by 8 times faster and thereby produce an extremely dense, uniform, and full-coverage perovskite thin film. The resulting planar perovskite solar cells can achieve an impressive power conversion efficiency up to 19.00% with an average efficiency of 17.38 ± 0.70% for 32 devices with an area of 5 × 2 mm, 13.91% for devices with a large area up to 1.13 cm(2). The perovskite films can be easily fabricated in air conditions with a relative humidity of 45-55%, which definitely has a promising prospect in industrial application of large-area perovskite solar panels.

  5. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.

    1994-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  6. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  7. Determination of Lead and Cadmium in environment materials from the planned area for a nuclear power plant by atomic absorption spectrophotometry method

    International Nuclear Information System (INIS)

    Supriyanto, C; Djokowidodo; Isyuniarto; Heri-Wahyudi; Ashar-Andrianto

    1996-01-01

    The determination of Pb and Cd in environment materials (water, cassava leaves and soil) have been done by atomic absorption spectrophotometry method, The determination of Pb and Cd was done with graphite tube atomizer (GTA) method at optimum condition : wavelength for Pb and Cd 217.0 nm and 228.8 nm; temperature/time ashing 550 o C/37 sec and 350 o C/52 sec; temperature/time atomizing 2000 o C/5.1 sec and 2000 o C/5.2 sec. Modifier for Pb was 3 μL of Mg 1000 μg/ml and Cd was 2 μL of Pd 2000 μg/ml. The content Pb in Spalun river, Hulu Putih river and sea water Lemah Abang was 0.94 ± 0.03; 0.91± 0.02; 4.71 ± 0.26 ng/ml respectively; the Cd content was 1.23 ± 0.11; 0.48 ± 0.01; 0.55 ± 0.01 ng/ml respectively. The Pb dan Cd content in cassava leaves was 163.24 ± 3.72 and 18.45 ± 1.46 ng/g respectively, while the Pb content in soil at the depth variation 0 - 5, 5 - 10, 10 - 20 and 20 - 30 Cm was 2.35 ± 0.15; 2.86 ± 0.16; 1.97 ± 0.11 and 2.19 ± 0.06 μg/g respectively and the Cd content was 43.67 ± 1.52; 37.01 ± 1.01; 31.68 ± 0.17 and 36.97 ± 1.63 ng/g respectively. SRM Citrous leaves from NSB and SRM Soil 7 from the IAEA local used to control the quality of the analyzed method. The Pb, Cd content in SRM was in accordance with the value in the certified legend

  8. Autoinflation Leading to Failure of Two-Piece Ambicor Implantable Penile Prosthesis: An Outcome from a Methodical Treatment of Recalcitrant Stuttering Priapism

    Directory of Open Access Journals (Sweden)

    R. Charles Welliver

    2014-01-01

    Full Text Available Introduction. We present the case of a patient who received a two-piece Ambicor penile prosthesis for idiopathic recurrent “stuttering” priapism refractory to other treatment options. The patient returned unable to deflate the device due to an interesting anatomically induced mechanical failure. Aims. To describe the method and findings of this inflatable prosthesis failure. Results. Prosthesis failure occurred due to restrictive corporal diameter and the unique characteristics of fluid reservoir location in the two-piece inflatable prosthesis. The patient was successfully converted to a semirigid prosthesis with resolution of the pain that was due to his prosthesis autoinflation. Conclusion. Stuttering priapism remains a challenging clinical problem. Penile implantation is a reasonable long-term solution in a patient refractory to less invasive options. In patients with fibrotic corpora, a malleable device should be considered (at least temporarily if unable to dilate comfortably to 13 mm.

  9. Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods

    Science.gov (United States)

    Baig, Muneer; Alam, Mohammad Asif; Alharthi, Nabeel

    2018-01-01

    The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance. PMID:29668709

  10. CRITICAL ASSESSMENT OF CONTRIBUTION FROM INDIAN PUBLICATIONS: THE ROLE OF IN SILICO DESIGNING METHODS LEADING TO DRUGS OR DRUG-LIKE COMPOUNDS USING TEXT BASED MINING AND ASSOCIATION

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2017-09-01

    Full Text Available Over the several decades, India is constantly challenged by communicable and non-communicable diseases which are originated either by poor lifestyle or by environmental factors. The pools of diseases are constantly posing serious threats to mankind especially among the poverty-stricken families. Scientific communities across the globe are working continuously to design drug molecules to overcome the burden of these life threaten diseases. In last three decades, many computational algorithms and tools have been developed to identify potential drug targets and their inhibitors. It is believed that computational techniques have reduced the time and money required to develop an inhibitor into drug. However, applicability and deliverability of these in silico techniques in rational drug designing are not fully evaluated. In the present study, PubMed/Medline extracted data driven analysis has been performed to highlight the influence and progress of the theoretical methods in the field of drug discovery across India and compared with the world. Drug discovery related keyword dictionary has been built and utilized to select only drug discovery related PubMed abstract. A second keyword set (related to bioinformatics tools is used for normalized pointwise mutual information (PMI based association analysis. Observations show that drug discovery has been an interdisciplinary research and used many tools starting with QSAR, docking, pharmacophore, Molecular Simulations etc. The publications contributed from India (2% are similar as compared to the contribution in total world publications, suggesting large scope in future. Data coverage as represented since 1990-2015 in PubMed as indicated by number of publications associated with drug discovery is almost same in world and India (~75%. Emerging institutes/Universities are contributing since last 10 years as observed from Indian publication list. However, this method has many limitations as discussed.

  11. Investigation of environmental change on the Tega Lake based on lake sediment analysis. Pt. 2. Dating of sediment by the lead-210/cesium-137 method and environmental change detected by the diatom assemblage analysis

    International Nuclear Information System (INIS)

    Hamada, Takaomi

    1998-01-01

    Sediment collected in the Tega Lake was dated by lead-210/cesium-137 method and environmental change in the Tega Lake was investigated by analysis of diatom remain assemblages in the sediment. Dating of the lead-210/cesium-137 method proved that the surface 30 cm-thickness of sediment in the Tega Lake was deposited during the recent 50 years. Diatom remain assemblage change in the Hon-Tega Lake sediment started in the early half of 1960's and the changes is characterized decrease of Fragilaria construens, that does not prefer to inhabit eutrophic water, and increase of Cyclotella meneghiniana that prefers to inhabit eutrophic water. This diatom assemblage change indicates that the Tega Lake was eutrophicated, and probably suggests water pollution in the Tega Lake. It is detected that influence of residential development around the Tega Lake and reclaiming by drainage on the Tega Lake. (author)

  12. Accuracy of measuring half- and quarter-value layers and appropriate aperture width of a convenient method using a lead-covered case in X-ray computed tomography.

    Science.gov (United States)

    Matsubara, Kosuke; Ichikawa, Katsuhiro; Murasaki, Yuichi; Hirosawa, Ayaka; Koshida, Kichiro

    2014-01-06

    Determination of the half-value layer (HVL) and quarter-value layer (QVL) values is not an easy task in x-ray computed tomography (CT), because a nonrotating x-ray tube must be used, which requires the assistance of service engineers. Therefore, in this study, we determined the accuracy of the lead-covered case method, which uses x-rays from a rotating x-ray tube, for measuring the HVL and QVL in CT. The lead-covered case was manufactured from polystyrene foam and a 4-mm thick lead plate. The ionizing chamber was placed in the center of the case, and aluminum filters were placed 15 cm above the aperture surface. Aperture widths of 1.0, 2.0, and 3.0 cm for a tube voltage of 110 kV and an aperture width of 2.0 cm for the tube voltages of 80 and 130 kV were used to measure exposure doses. The results of the HVL and QVL were compared with those of the conventional nonrotating method. A 2.0-cm aperture was believed to be adequate, because of its small differences in the HVL and QVL in the nonrotating method and its reasonable exposure dose level. When the 2.0-cm aperture was used, the lead-covered case method demonstrated slightly larger HVLs and QVLs (0.03-0.06 mm for the HVL and 0.2-0.4 mm for the QVL) at all the tube voltage settings. However, the differences in the effective energy were 0.1-0.3 keV; therefore, it could be negligible in an organ-absorbed dose evaluation and a quality assurance test for CT.

  13. Application of statistical methods to the quality assurance process in the serial production of containers of type lead Cpb-M and Cpb-G

    International Nuclear Information System (INIS)

    Zuniga Santana, J.F.; Fernadez Rondon, M.; Viant Garrido, E.; Torres Berdeguez, M.B.; Fernadez, A.

    1998-01-01

    Nowadays the statistic has an action change and its applications have to do with all the branches of the scientific knowledge. Constantly new applications arise for the statistic, one of those is in the insurance of the quality of productive processes. The process of serial production of the devices of shielding gamma type CPb-m and CPb-g are carried out in correspondence with the designed methodology and validated in the Department of Technologic Design of the Center of Nuclear Technology (CTN). With view to execute the normative ones national and international for this packing type were designed a System of Insurance of the Quality (SAC) based on the normative ISO composed by a manual of quality and a manual of procedures where is described of detailed way each one of the stages. Presently work different statistical methods are analyzed with the objective of selecting the good one to determine the factors that have bigger influence in to the quality of production of the devices of shielding gamma used by the CENTIS for the packing and transportation of the radioactive preparations

  14. Development of a highly precise ID-ICP-SFMS method for analysis of low concentrations of lead in rice flour reference materials.

    Science.gov (United States)

    Zhu, Yanbei; Inagaki, Kazumi; Yarita, Takashi; Chiba, Koichi

    2008-07-01

    Microwave digestion and isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-SFMS) has been applied to the determination of Pb in rice flour. In order to achieve highly precise determination of low concentrations of Pb, the digestion blank for Pb was reduced to 0.21 ng g(-1) after optimization of the digestion conditions, in which 20 mL analysis solution was obtained after digestion of 0.5 g rice flour. The observed value of Pb in a non-fat milk powder certified reference material (CRM), NIST SRM 1549, was 16.8 +/- 0.8 ng g(-1) (mean +/- expanded uncertainty, k = 2; n = 5), which agreed with the certified value of 19 +/- 3 ng g(-1) and indicated the effectiveness of the method. Analytical results for Pb in three brown rice flour CRMs, NIST SRM 1568a, NIES CRM 10-a, and NIES CRM 10-b, were 7.32 +/- 0.24 ng g(-1) (n = 5), 1010 +/- 10 ng g(-1) (n = 5), and 1250 +/- 20 ng g(-1) (n = 5), respectively. The concentration of Pb in a candidate white rice flour reference material (RM) sample prepared by the National Metrology Institute of Japan (NMIJ) was observed to be 4.36 +/- 0.28 ng g(-1) (n = 10 bottles).

  15. Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods. 1. Artificially aged model samples.

    Science.gov (United States)

    Monico, Letizia; Van der Snickt, Geert; Janssens, Koen; De Nolf, Wout; Miliani, Costanza; Verbeeck, Johan; Tian, He; Tan, Haiyan; Dik, Joris; Radepont, Marie; Cotte, Marine

    2011-02-15

    On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO(4), PbCrO(4)·xPbSO(4), or PbCrO(4)·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1-3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr(2)O(3)·2H(2)O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr(2)(SO(4))(3)·H(2)O or (CH(3)CO(2))(7)Cr(3)(OH)(2) [chromium(III) acetate hydroxide], is likely.

  16. HAMS: High-Affinity Mass Spectrometry Screening. A High-Throughput Screening Method for Identifying the Tightest-Binding Lead Compounds for Target Proteins with No False Positive Identifications.

    Science.gov (United States)

    Imaduwage, Kasun P; Go, Eden P; Zhu, Zhikai; Desaire, Heather

    2016-11-01

    A major challenge in drug discovery is the identification of high affinity lead compounds that bind a particular target protein; these leads are typically identified by high throughput screens. Mass spectrometry has become a detection method of choice in drug screening assays because the target and the ligand need not be modified. Label-free assays are advantageous because they can be developed more rapidly than assays requiring labels, and they eliminate the risk of the label interfering with the binding event. However, in commonly used MS-based screening methods, detection of false positives is a major challenge. Here, we describe a detection strategy designed to eliminate false positives. In this approach, the protein and the ligands are incubated together, and the non-binders are separated for detection. Hits (protein binders) are not detectable by MS after incubation with the protein, but readily identifiable by MS when the target protein is not present in the incubation media. The assay was demonstrated using three different proteins and hundreds of non-inhibitors; no false positive hits were identified in any experiment. The assay can be tuned to select for ligands of a particular binding affinity by varying the quantity of protein used and the immobilization method. As examples, the method selectively detected inhibitors that have K i values of 0.2 μM, 50 pM, and 700 pM. These findings demonstrate that the approach described here compares favorably with traditional MS-based screening methods. Graphical Abstract ᅟ.

  17. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... Regional Offices Labs and Research Centers Lead (Pb) Air Pollution Contact Us Share As a result of EPA's ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Basic Information How does lead get in the ...

  18. Decay heat removal analyses in heavy-liquid-metal-cooled fast breeding reactors. Development of the thermal-hydraulic analysis method for lead-bismuth-cooled, natural-circulation reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Takaaki; Enuma, Yasuhiro [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Iwasaki, Takashi [Nuclear Energy System Inc., Tokyo (Japan); Ohyama, Kazuhiro [Advanced Reactor Technology Co., Ltd., Tokyo (Japan)

    2001-05-01

    The feasibility study on future commercial fast breeder reactors in Japan has been conducted at JNC, in which various plant design options with all the possible coolant and fuel types are investigated to determine the conditions for the future detailed study. Lead-bismuth eutectic coolant has been selected as one of the possible coolant options. During the phase-I activity of the feasibility study in FY1999 and FY2000, several plant concepts, which were cooled by the heavy liquid metal coolant, were examined to evaluate the feasibility mainly with respect to economical competitiveness with other coolant reactors. A medium-scale (300 - 550 MWe) plant, cooled by a lead-bismuth natural circulation flow in a pool type vessel, was selected as the most possible plant concept for the heavy liquid metal coolant. Thus, a conceptual design study for a lead-bismuth-cooled, natural-circulation reactor of 400 MWe has been performed at JNC to identify remaining difficulties in technological aspect and its construction cost evaluation. In this report, a thermal-hydraulic analysis method for lead-bismuth-cooled, natural-circulation reactors is described. A Multi-dimensional Steam Generator analysis code (MSG) was applied to evaluate the natural circulation plant by combination with a flow-network-type, plant dynamics code (Super-COPD). By using this combined multi-dimensional plant dynamics code, decay heat removals, ULOHS and UTOP accidents were evaluated for the 100 MWe STAR-LM concept designed by ANL. In addition, decay heat removal by the Primary Reactor Auxiliary Cooling System (PRACS) in the 400 MWe lead-bismuth-cooled, natural-circulation reactor, being studied at JNC, was analyzed. In conclusion, it becomes clear that the combined multi-dimensional plant dynamics code is suitably applicable to analyses of lead-bismuth-cooled, natural-circulation reactors to evaluate thermal-hydraulic phenomena during steady-state and transient conditions. (author)

  19. Working towards accreditation by the International Standards Organization 15189 Standard: how to validate an in-house developed method an example of lead determination in whole blood by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Garcia Hejl, Carine; Ramirez, Jose Manuel; Vest, Philippe; Chianea, Denis; Renard, Christophe

    2014-09-01

    Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.

  20. Solid phase extraction method for the determination of lead, nickel, copper and manganese by flame atomic absorption spectrometry using sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) in water samples

    International Nuclear Information System (INIS)

    Rekha, D.; Suvardhan, K.; Kumar, J. Dilip; Subramanyam, P.; Prasad, P. Reddy; Lingappa, Y.; Chiranjeevi, P.

    2007-01-01

    A novel column solid phase extraction procedure was developed for the determination of lead, nickel, copper and manganese in various water samples by flame atomic absorption spectrometry (FAAS) after preconcentration on sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) supported by Amberlite XAD-7. The sorbed element was subsequently eluted with 1 M nitric acid and the acid eluates are analysed by Flame atomic absorption spectrometry (FAAS). Various parameters such as pH, amount of adsorbent, eluent type and volume, flow-rate of the sample solution, volume of the sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of above mentioned metal ions was about 6.0 ± 0.2. The loading capacity of adsorbent for Pb, Cu, Ni and Mn were found to 28, 26, 22 and 20 x 10 -6 g/mL, respectively. The recoveries of lead, copper, nickel and manganese under optimum conditions were found to be 96.7-99.2 at the 95% confident level. The limit of detection was 3.0, 3.2, 2.8 and 3.6 x 10 -6 g/mL for lead, copper, nickel and manganese, respectively by applying a preconcentration factor 50. The proposed enrichment method was applied for metal ions in various water samples. The results were obtained are good agreement with reported method

  1. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  2. Lead - nutritional considerations

    Science.gov (United States)

    ... billion people had toxic (poisonous) blood lead levels. Food Sources Lead can be found in canned goods if there is lead solder in the ... to bottled water for drinking and cooking. Avoid canned goods from foreign ... cans goes into effect. If imported wine containers have a lead foil ...

  3. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radionuclides and is therefore a Resource Conservation and Recovery Act (RCRA) D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Lab. decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 100 metric tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 280 kPa (40 psig) rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a pump. A pump sends the slurry mixture back to the spray gun, creating a continuous process

  4. Erythrocyte fluorescence and lead intoxication.

    Science.gov (United States)

    Clark, K G

    1976-01-01

    Blood samples from people exposed to inorganic lead were examined by fluorescence microscopy for excess erythrocyte porphyrin. With continued lead absorption, fluorescent erythrocytes appeared in the circulation of workers handling this metal or its compounds, and they progressively increased in number and brilliance. These changes ensued if the blood lead concentration was maintained above 2-42 mumol/l (50 mug/100 ml), and preceded any material fall in the haemoglobin value. At one factory, 62-5% of 81 symptomless workers showed erythrocyte fluorescence attributable to the toxic effects of lead. Excess fluorocytes were found in blood samples from a child with pica and three of her eight siblings. These four were subsequently shown to have slightly increased blood lead concentrations (2-03 to 2-32 mumol/l). Fluorescence microscopy for excess erythrocyte porphyrin is a sensitive method for the detection of chronic lead intoxication. A relatively slight increase in the blood lead is associated with demonstrabel changes in erythrocyte porphyrin content. The procedure requires little blood, and may be performed upon stored samples collected for lead estimation. The results are not readily influenced by contamination, and provide good confirmatory evidence for the absorption of biochemically active lead. PMID:963005

  5. Study of two step constant current charging method with EV`s valve-regulated lead acid batteries for nighttime load leveling; Yakan denryoku wo yuko katsuyo dekiru denki jidoshayo namari denchi no nidantei denryu judenho no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ikeya, T.; Mita, Y.; Iwahori, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Iwasaki, M.; Takagi, S.; Sugii, Y.; Yada, M.; Sakabe, T.; Kosaka, E.; Tsuchiya, H.; Kanetsuki, M.; Nasu, H.; Ono, M.; Adachi, K.; Narisoko, H.; Nishiyama, K.

    1997-02-01

    In the constant-current/constant-voltage charging method that has been in application for EV (electric vehicle) lead-acid batteries, power load is generated only at the initial part of the charging process, and therefore the method cannot be said to be sufficiently contributory to the levelling of power loads. In this report, a proposed 2-step constant-current charging method is assessed for applicability, and another charging method is introduced, which extends battery life and utilizes low-cost night-time power more effectively. It is found that the proposed 2-step constant-current charging method (1st step: 12A, 2nd step: 3A) completes the charging process in eight hours, that it assumes a charging pattern more suitable for contributing to the effective use of night-time power than the conventional method, and that it extends the battery life of approximately 170 cycles to approximately 300 cycles. In a study seeking for a charging method capable of utilizing night-time power more efficiently, the 1st-step current of 12A is increased to 30A for shortening the charging time, and then it is found that this change extends the battery cycle life and improves on charging efficiency. The conclusion is that possibilities are high that an increase in the 1st-step current prolongs the battery life cycle and shortens the charting time. 16 refs., 28 figs., 8 tabs.

  6. Simultaneous beam sampling and aperture shape optimization for SPORT

    International Nuclear Information System (INIS)

    Zarepisheh, Masoud; Li, Ruijiang; Xing, Lei; Ye, Yinyu

    2015-01-01

    Purpose: Station parameter optimized radiation therapy (SPORT) was recently proposed to fully utilize the technical capability of emerging digital linear accelerators, in which the station parameters of a delivery system, such as aperture shape and weight, couch position/angle, gantry/collimator angle, can be optimized simultaneously. SPORT promises to deliver remarkable radiation dose distributions in an efficient manner, yet there exists no optimization algorithm for its implementation. The purpose of this work is to develop an algorithm to simultaneously optimize the beam sampling and aperture shapes. Methods: The authors build a mathematical model with the fundamental station point parameters as the decision variables. To solve the resulting large-scale optimization problem, the authors devise an effective algorithm by integrating three advanced optimization techniques: column generation, subgradient method, and pattern search. Column generation adds the most beneficial stations sequentially until the plan quality improvement saturates and provides a good starting point for the subsequent optimization. It also adds the new stations during the algorithm if beneficial. For each update resulted from column generation, the subgradient method improves the selected stations locally by reshaping the apertures and updating the beam angles toward a descent subgradient direction. The algorithm continues to improve the selected stations locally and globally by a pattern search algorithm to explore the part of search space not reachable by the subgradient method. By combining these three techniques together, all plausible combinations of station parameters are searched efficiently to yield the optimal solution. Results: A SPORT optimization framework with seamlessly integration of three complementary algorithms, column generation, subgradient method, and pattern search, was established. The proposed technique was applied to two previously treated clinical cases: a head and

  7. Simultaneous beam sampling and aperture shape optimization for SPORT

    Energy Technology Data Exchange (ETDEWEB)

    Zarepisheh, Masoud; Li, Ruijiang; Xing, Lei, E-mail: Lei@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Ye, Yinyu [Department of Management Science and Engineering, Stanford University, Stanford, California 94305 (United States)

    2015-02-15

    Purpose: Station parameter optimized radiation therapy (SPORT) was recently proposed to fully utilize the technical capability of emerging digital linear accelerators, in which the station parameters of a delivery system, such as aperture shape and weight, couch position/angle, gantry/collimator angle, can be optimized simultaneously. SPORT promises to deliver remarkable radiation dose distributions in an efficient manner, yet there exists no optimization algorithm for its implementation. The purpose of this work is to develop an algorithm to simultaneously optimize the beam sampling and aperture shapes. Methods: The authors build a mathematical model with the fundamental station point parameters as the decision variables. To solve the resulting large-scale optimization problem, the authors devise an effective algorithm by integrating three advanced optimization techniques: column generation, subgradient method, and pattern search. Column generation adds the most beneficial stations sequentially until the plan quality improvement saturates and provides a good starting point for the subsequent optimization. It also adds the new stations during the algorithm if beneficial. For each update resulted from column generation, the subgradient method improves the selected stations locally by reshaping the apertures and updating the beam angles toward a descent subgradient direction. The algorithm continues to improve the selected stations locally and globally by a pattern search algorithm to explore the part of search space not reachable by the subgradient method. By combining these three techniques together, all plausible combinations of station parameters are searched efficiently to yield the optimal solution. Results: A SPORT optimization framework with seamlessly integration of three complementary algorithms, column generation, subgradient method, and pattern search, was established. The proposed technique was applied to two previously treated clinical cases: a head and

  8. Lead inclusions in aluminium

    International Nuclear Information System (INIS)

    Johnson, E.; Johansen, A.; Sarholt-Kristensen, L.; Andersen, H.H.; Grabaek, L.; Bohr, J.

    1990-01-01

    Ion implantation at room temperature of lead into aluminum leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurized (∼ 1-5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa. Recently the authors have observed the result that the lead inclusions in aluminum exhibit both superheating and supercooling. In this paper they review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminum matrix were studied by x-ray diffraction

  9. Leading change: a concept analysis.

    Science.gov (United States)

    Nelson-Brantley, Heather V; Ford, Debra J

    2017-04-01

    To report an analysis of the concept of leading change. Nurses have been called to lead change to advance the health of individuals, populations, and systems. Conceptual clarity about leading change in the context of nursing and healthcare systems provides an empirical direction for future research and theory development that can advance the science of leadership studies in nursing. Concept analysis. CINAHL, PubMed, PsycINFO, Psychology and Behavioral Sciences Collection, Health Business Elite and Business Source Premier databases were searched using the terms: leading change, transformation, reform, leadership and change. Literature published in English from 2001 - 2015 in the fields of nursing, medicine, organizational studies, business, education, psychology or sociology were included. Walker and Avant's method was used to identify descriptions, antecedents, consequences and empirical referents of the concept. Model, related and contrary cases were developed. Five defining attributes of leading change were identified: (a) individual and collective leadership; (b) operational support; (c) fostering relationships; (d) organizational learning; and (e) balance. Antecedents were external or internal driving forces and organizational readiness. The consequences of leading change included improved organizational performance and outcomes and new organizational culture and values. A theoretical definition and conceptual model of leading change were developed. Future studies that use and test the model may contribute to the refinement of a middle-range theory to advance nursing leadership research and education. From this, empirically derived interventions that prepare and enable nurses to lead change to advance health may be realized. © 2016 John Wiley & Sons Ltd.

  10. Simultaneous beam sampling and aperture shape optimization for SPORT.

    Science.gov (United States)

    Zarepisheh, Masoud; Li, Ruijiang; Ye, Yinyu; Xing, Lei

    2015-02-01

    Station parameter optimized radiation therapy (SPORT) was recently proposed to fully utilize the technical capability of emerging digital linear accelerators, in which the station parameters of a delivery system, such as aperture shape and weight, couch position/angle, gantry/collimator angle, can be optimized simultaneously. SPORT promises to deliver remarkable radiation dose distributions in an efficient manner, yet there exists no optimization algorithm for its implementation. The purpose of this work is to develop an algorithm to simultaneously optimize the beam sampling and aperture shapes. The authors build a mathematical model with the fundamental station point parameters as the decision variables. To solve the resulting large-scale optimization problem, the authors devise an effective algorithm by integrating three advanced optimization techniques: column generation, subgradient method, and pattern search. Column generation adds the most beneficial stations sequentially until the plan quality improvement saturates and provides a good starting point for the subsequent optimization. It also adds the new stations during the algorithm if beneficial. For each update resulted from column generation, the subgradient method improves the selected stations locally by reshaping the apertures and updating the beam angles toward a descent subgradient direction. The algorithm continues to improve the selected stations locally and globally by a pattern search algorithm to explore the part of search space not reachable by the subgradient method. By combining these three techniques together, all plausible combinations of station parameters are searched efficiently to yield the optimal solution. A SPORT optimization framework with seamlessly integration of three complementary algorithms, column generation, subgradient method, and pattern search, was established. The proposed technique was applied to two previously treated clinical cases: a head and neck and a prostate case

  11. VOLUMETRIC LEAD ASSAY

    International Nuclear Information System (INIS)

    Ebadian, M.A.; Dua, S.K.; Roelant, David; Kumar, Sachin

    2001-01-01

    This report describes a system for handling and radioassay of lead, consisting of a robot, a conveyor, and a gamma spectrometer. The report also presents a cost-benefit analysis of options: radioassay and recycling lead vs. disposal as waste

  12. Lead isotope in mineral exploration

    International Nuclear Information System (INIS)

    Gulson, B.L.

    1986-01-01

    This book provides an up-to-date state-of-the-art review of lead isotopes in mineral exploration. Beginning with an historical review on suggested uses of lead isotopes in mineral exploration, the author then outlines the theoretical aspects of lead isotopes and illustrates that the method is based on well-known principles of radioactive decay, from which isotopic signatures for different styles of mineralization are derived. The varying isotopic signatures are then introduced. The major part of the book details over 40 case histories for base and precious metals, uranium and tin using sampling media such as sulfides, gossans, soils, weathered bedrock, vegetation and groundwaters. Advantages and disadvantages of each are discussed. Examples are given of the use of lead isotopes in testing conceptual models for exploration. The success rate and cost-effectiveness of the method are illustrated by actual exploration examples. Analytical advances which should lower the cost of the method and future uses are outlined. Many of the case histories use recently published or unpublished data, 27 tables of which are given in an appendix. Details of sampling, the methods for obtaining the isotope ratios, and a commercially-available integrated lead isotope service are also provided. (Auth.)

  13. NA49: lead-lead collision

    CERN Multimedia

    1996-01-01

    This is an image of an actual lead ion collision taken from tracking detectors on the NA49 experiment, part of the heavy ion project at CERN. These collisions produce a very complicated array of hadrons as the heavy ions break up. It is hoped that one of these collisions will eventually create a new state of matter known as quark-gluon plasma.

  14. Atrioventricular Pacemaker Lead Reversal

    Directory of Open Access Journals (Sweden)

    Mehmet K Aktas, MD

    2007-01-01

    Full Text Available During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.

  15. Lead Poisoning (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Lead Poisoning KidsHealth / For Parents / Lead Poisoning What's in ... Print en español La intoxicación por plomo About Lead Poisoning If you have young kids, it's important ...

  16. Superconductivity in nanostructured lead

    Science.gov (United States)

    Lungu, Anca; Bleiweiss, Michael; Amirzadeh, Jafar; Saygi, Salih; Dimofte, Andreea; Yin, Ming; Iqbal, Zafar; Datta, Timir

    2001-01-01

    Three-dimensional nanoscale structures of lead were fabricated by electrodeposition of pure lead into artificial porous opal. The size of the metallic regions was comparable to the superconducting coherence length of bulk lead. Tc as high as 7.36 K was observed, also d Tc/d H was 2.7 times smaller than in bulk lead. Many of the characteristics of these differ from bulk lead, a type I superconductor. Irreversibility line and magnetic relaxation rates ( S) were also studied. S( T) displayed two maxima, with a peak value about 10 times smaller than that of typical high- Tc superconductors.

  17. Method

    Directory of Open Access Journals (Sweden)

    Ling Fiona W.M.

    2017-01-01

    Full Text Available Rapid prototyping of microchannel gain lots of attention from researchers along with the rapid development of microfluidic technology. The conventional methods carried few disadvantages such as high cost, time consuming, required high operating pressure and temperature and involve expertise in operating the equipment. In this work, new method adapting xurography method is introduced to replace the conventional method of fabrication of microchannels. The novelty in this study is replacing the adhesion film with clear plastic film which was used to cut the design of the microchannel as the material is more suitable for fabricating more complex microchannel design. The microchannel was then mold using polymethyldisiloxane (PDMS and bonded with a clean glass to produce a close microchannel. The microchannel produced had a clean edge indicating good master mold was produced using the cutting plotter and the bonding between the PDMS and glass was good where no leakage was observed. The materials used in this method is cheap and the total time consumed is less than 5 hours where this method is suitable for rapid prototyping of microchannel.

  18. Lead isotope analyses of standard rock samples

    International Nuclear Information System (INIS)

    Koide, Yoshiyuki; Nakamura, Eizo

    1990-01-01

    New results on lead isotope compositions of standard rock samples and their analytical procedures are reported. Bromide form anion exchange chromatography technique was adopted for the chemical separation lead from rock samples. The lead contamination during whole analytical procedure was low enough to determine lead isotope composition of common natural rocks. Silica-gel activator method was applied for emission of lead ions in the mass spectrometer. Using the data reduction of 'unfractionated ratios', we obtained good reproducibility, precision and accuracy on lead isotope compositions of NBS SRM. Here we present new reliable lead isotope compositions of GSJ standard rock samples and USGS standard rock, BCR-1. (author)

  19. Lead in the environment

    Science.gov (United States)

    Pattee, Oliver H.; Pain, Deborah J.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

    2003-01-01

    Anthropogenic uses of lead have probably altered its availability and environmental distribution more than any other toxic element. Consequently, lead concentrations in many living organisms may be approaching thresholds of toxicity for the adverse effects of lead. Such thresholds are difficult to define, as they vary with the chemical and physical form of lead, exposure regime, other elements present and also vary both within and between species. The technological capability to accurately quantify low lead concentrations has increased over the last decade, and physiological and behavioral effects have been measured in wildlife with tissue lead concentrations below those previously considered safe for humans.s.236 Consequently. lead criteria for the protection of wildlife and human health are frequently under review, and 'thresholds' of lead toxicity are being reconsidered. Proposed lead criteria for the protection of natural resources have been reviewed by Eisler. Uptake of lead by plants is limited by its generally low availability in soils and sediments, and toxicity may be limited by storage mechanisms and its apparently limited translocation within most plants. Lead does not generally accumulate within the foliar parts of plants, which limits its transfer to higher trophic levels. Although lead may concentrate in plant and animal tissues, no evidence of biomagnification exists. Acid deposition onto surface waters and soils with low buffering capacity may influence the availability of lead for uptake by plants and animals, and this may merit investigation at susceptible sites. The biological significance of chronic low-level lead exposure to wildlife is sometimes difficult to quantify. Animals living in urban environments or near point sources of lead emission are inevitably subject to greater exposure to lead and enhanced risk of lead poisoning. Increasingly strict controls on lead emissions in many countries have reduced exposure to lead from some sources

  20. [Study on the method for the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current arc full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES)].

    Science.gov (United States)

    Hao, Zhi-hong; Yao, Jian-zhen; Tang, Rui-ling; Zhang, Xue-mei; Li, Wen-ge; Zhang, Qin

    2015-02-01

    The method for the determmation of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current are full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES) was established. Direct current are full spectrum direct reading atomic emission spectrometer with a large area of solid-state detectors has functions of full spectrum direct reading and real-time background correction. The new electrodes and new buffer recipe were proposed in this paper, and have applied for national patent. Suitable analytical line pairs, back ground correcting points of elements and the internal standard method were selected, and Ge was used as internal standard. Multistage currents were selected in the research on current program, and each current set different holding time to ensure that each element has a good signal to noise ratio. Continuous rising current mode selected can effectively eliminate the splash of the sample. Argon as shielding gas can eliminate CN band generating and reduce spectral background, also plays a role in stabilizing the are, and argon flow 3.5 L x min(-1) was selected. Evaporation curve of each element was made, and it was concluded that the evaporation behavior of each element is consistent, and combined with the effects of different spectrographic times on the intensity and background, the spectrographic time of 35s was selected. In this paper, national standards substances were selected as a standard series, and the standard series includes different nature and different content of standard substances which meet the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples. In the optimum experimental conditions, the detection limits for B, Mo, Ag, Sn and Pb are 1.1, 0.09, 0.01, 0.41, and 0.56 microg x g(-1) respectively, and the precisions (RSD, n=12) for B, Mo, Ag, Sn and Pb are 4.57%-7.63%, 5.14%-7.75%, 5.48%-12.30%, 3.97%-10.46%, and 4.26%-9.21% respectively. The analytical accuracy was

  1. ALICE: Simulated lead-lead collision

    CERN Multimedia

    2003-01-01

    This track is an example of simulated data modelled for the ALICE detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. ALICE will focus on the study of collisions between nuclei of lead, a heavy element that produces many different particles when collided. It is hoped that these collisions will produce a new state of matter known as the quark-gluon plasma, which existed billionths of a second after the Big Bang.

  2. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  3. Lead-Free Piezoelectrics

    CERN Document Server

    Nahm, Sahn

    2012-01-01

    Ecological restrictions in many parts of the world are demanding the elimination of Pb from all consumer items. At this moment in the piezoelectric ceramics industry, there is no issue of more importance than the transition to lead-free materials. The goal of Lead-Free Piezoelectrics is to provide a comprehensive overview of the fundamentals and developments in the field of lead-free materials and products to leading researchers in the world. The text presents chapters on demonstrated applications of the lead-free materials, which will allow readers to conceptualize the present possibilities and will be useful for both students and professionals conducting research on ferroelectrics, piezoelectrics, smart materials, lead-free materials, and a variety of applications including sensors, actuators, ultrasonic transducers and energy harvesters.

  4. Lead poisoning in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Bond, E; Kubin, R

    1949-01-01

    Diagnosis was made from clinical observation and laboratory examination of nine cases. A successful treatment is described based on the similarity of the metabolism of lead and calcium, the lead being deposited in the bones where it is harmless, if it remains there. Details are given of the treatment.

  5. Developmental immunotoxicology of lead

    International Nuclear Information System (INIS)

    Dietert, Rodney R.; Lee, Ji-Eun; Hussain, Irshad; Piepenbrink, Michael

    2004-01-01

    The heavy metal, lead, is a known developmental immunotoxicant that has been shown to produce immune alterations in humans as well as other species. Unlike many compounds that exert adverse immune effects, lead exposure at low to moderate levels does not produce widespread loss of immune cells. In contrast, changes resulting from lead exposure are subtle at the immune cell population level but, nevertheless, can be functionally dramatic. A hallmark of lead-induced immunotoxicity is a pronounced shift in the balance in T helper cell function toward T helper 2 responses at the expense of T helper 1 functions. This bias alters the nature and range of immune responses that can be produced thereby influencing host susceptibility to various diseases. Immunotoxic responses to lead appear to differ across life stages not only quantitatively with regard to dose response, but also qualitatively in terms of the spectrum of immune alterations. Experimental studies in several lab animal species suggest the latter stages of gestation are a period of considerable sensitivity for lead-induced immunotoxicity. This review describes the basic characteristics of lead-induced immunotoxicity emphasizing experimental animal results. It also provides a framework for the consideration of toxicant exposure effects across life stages. The existence of and probable basis for developmental windows of immune hyper-susceptibility are presented. Finally, the potential for lead to serve as a perinatal risk factor for childhood asthma as well as other diseases is considered

  6. Leading Educational Change Wisely

    Science.gov (United States)

    Forrester, Gillian

    2011-01-01

    In this article, the author reviews Christopher Branson's book entitled "Leading Educational Change Wisely". The book provides an alternative and engaging perspective on leading educational change. Branson utilises "wisdom" as its central conceptual device to present a thought-provoking and philosophical account on how leaders are able to build a…

  7. Lead-free piezoceramics.

    Science.gov (United States)

    Saito, Yasuyoshi; Takao, Hisaaki; Tani, Toshihiko; Nonoyama, Tatsuhiko; Takatori, Kazumasa; Homma, Takahiko; Nagaya, Toshiatsu; Nakamura, Masaya

    2004-11-04

    Lead has recently been expelled from many commercial applications and materials (for example, from solder, glass and pottery glaze) owing to concerns regarding its toxicity. Lead zirconium titanate (PZT) ceramics are high-performance piezoelectric materials, which are widely used in sensors, actuators and other electronic devices; they contain more than 60 weight per cent lead. Although there has been a concerted effort to develop lead-free piezoelectric ceramics, no effective alternative to PZT has yet been found. Here we report a lead-free piezoelectric ceramic with an electric-field-induced strain comparable to typical actuator-grade PZT. We achieved this through the combination of the discovery of a morphotropic phase boundary in an alkaline niobate-based perovskite solid solution, and the development of a processing route leading to highly textured polycrystals. The ceramic exhibits a piezoelectric constant d33 (the induced charge per unit force applied in the same direction) of above 300 picocoulombs per newton (pC N(-1)), and texturing the material leads to a peak d33 of 416 pC N(-1). The textured material also exhibits temperature-independent field-induced strain characteristics.

  8. Lead poisoning in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M R; Lewis, G

    1963-08-03

    Within a short period, 14 cases of lead poisoning in the dogs have been encountered. A detailed record appears justified as no published reference can be found to this condition occurring in Britain and because reports from other countries stress the similarity of the clinical manifestations of lead poisoning to those of the common infections of the dog. Five of the 14 clinical cases of lead poisoning are described. The available literature is reviewed and the diagnosis and significance of the condition discussed. 19 references, 2 tables.

  9. Lead in Construction

    National Research Council Canada - National Science Library

    1993-01-01

    Although Occupational Safety and Health Administration (OSHA) regulations for occupational lead exposure have been in effect since 1971 for the construction and general industries, the agency regulations for general industry in 1978...

  10. Radiation shielding lead shield

    International Nuclear Information System (INIS)

    Dei, Shoichi.

    1991-01-01

    The present invention concerns lead shields for radiation shielding. Shield boxes are disposed so as to surround a pipeline through which radioactive liquids, mists or like other objects are passed. Flanges are formed to each of the end edges of the shield boxes and the shield boxes are connected to each other by the flanges. Upon installation, empty shield boxes not charged with lead particles and iron plate shields are secured at first at the periphery of the pipeline. Then, lead particles are charged into the shield boxes. This attains a state as if lead plate corresponding to the depth of the box is disposed. Accordingly, operations for installation, dismantling and restoration can be conducted in an empty state with reduced weight to facilitate the operations. (I.S.)

  11. Lead poisoning in mink

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, J G

    1962-03-01

    This paper describes a case of lead poisoning in minks. The mink were housed in pens which had been painted with a bridge paint containing lead. They had chewed on the pen and ingested the paint. The animals that did not die were moved to new pens, and vitamin D and calcium gluconate were added to their diets. In three days, a marked improvement was seen in the food and water consumption, and convolutions became less frequent.

  12. Lead poisoning in dogs

    International Nuclear Information System (INIS)

    Zook, B.C.; Carpenter, J.L.; Leeds, E.B.

    1969-01-01

    Lead poisoning was diagnosed and studied in 60 dogs. It was found that lead poisoning is a common disease of young dogs, especially in the summer and fall, and is related to their chewing and eating habits resulting in the ingestion of paint, linoleum, or other lead-containing materials. The signs were characterized by gastrointestinal dysfunction (colic, vomiting, and diarrhea) and nervous disorders (convulsions, hysteria, nervousness, behavioral changes). The blood findings, which the authors consider nearly pathognomonic, consisted of numerous stippled and immature (especially nucleated) erythrocytes in the absence of severe anemia. Protein and casts were frequently found in the urine. Radiography sometimes revealed lead-containing particles in the gastro-intestinal tract, and lead lines were occasionally detected in the metaphysis of long bones in immature dogs. Treatment with calcium ethylenediamine-tetraacetic acid resulted in rapid and often dramatic recoveries in nearly all instances. Removal of lead from the gastrointestinal tract and treatment to relieve pronounced central nervous disorders was sometimes necessary. 40 references, 6 figures, 7 tables

  13. Leading Your Leaders

    Science.gov (United States)

    Hale, Wayne N.

    2008-01-01

    life is good. More often when an unbelievably difficult test fails, we are left with a very long discussion of why and what was wrong in the design or execution of the test. Make sure that the test is well defined. Even then, it is important to explain to your leaders what inherent accuracy (or error) the test conditions or equipment have and what the assumptions or initial conditions were for the test. Test results without a good understanding of the test's accuracy or the pedigree of the test assumptions are worth very little. Finally, there is flight test data. Always limited, never at the edge of the envelope, it still shows how the real hardware works in a combined environment. Flight experience is dangerous because it typically doesn't show how close to the edge of the cliff the equipment is operating, but it does demonstrate how the hardware really works. A flight test is the ultimate test, again taken with the knowledge that it is probably not the extreme but something more like the middle of the environmental and systems performance. Good understanding of a problem and its solution always relies on a combination of all these methods. Be sure to lead your leaders by using all the tools you have at your disposal. At the end of the day, decisions in space flight always come down to a risk trade. Our business is not remotely safe, not in the sense that the public, the media, or our legislators use the term. Everything we do has a risk, cost, schedule, or performance trade-off. For your leaders to make an appropriate decision, you need to educate them, lead them, talk with them, and engage them in the discussion until full understanding takes place. It's your job. *

  14. Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

    Science.gov (United States)

    Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

    2006-12-15

    Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

  15. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  16. Lead pollution: lead content in milk from cows fed on contaminated forages

    Energy Technology Data Exchange (ETDEWEB)

    Sapetti, C; Arduino, E; Durio, P

    1973-01-01

    Lead toxicity is reviewed, and the history of the lead poisoning is described. Much of the lead pollution in soil is due to automobile exhaust. Two milk cows were fed forage with added lead acetate. The 20 kg of lead corresponded to 50 ppm, a level that is often found in hays near major highways. The cows milk was then analyzed for lead content. During the first and second phase of administration of lead salts, the milk cows did not show any evident symptoms of intoxication. The lead in the milk did have a marked correlation with the administered lead. The lead doses did not last long enough for chronic symptoms to begin. The dosage of lead in milk, due to the facility of drawing samples and the relevant levels of response, could represent a valid method for diagnosing incipient chronic intoxications.

  17. Lead: Aspects of its ecology and environmental toxicity. [physiological effects of lead compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    An analysis of lead toxicity in the Hawaiian environment was conducted. It was determined that lead enters the environment as an industrial contaminant resulting from the combustion of leaded gasoline. The amount of lead absorbed by the plants in various parts of the Hawaiian Islands is reported. The disposition of lead in the sediments of canals and yacht basins was investigated. The methods for conducting the surveys of lead content are described. Possible consequences of continued environmental pollution by burning leaded gasoline are discussed.

  18. Isolation of radioactive thallium from lead targets

    International Nuclear Information System (INIS)

    Kozlova, M.D.; Sevast'yanova, A.S.; Malinin, A.B.; Kurenkov, N.V.

    1989-01-01

    Two methods of thallium-201 preperation from Pb-targets irradiated with protons: precipitation-extraction (1) and extraction (2) - are developed. When the target irraiated is extracted during the time necessary for bismuth-201 transformation into lead-201, lead macroquantity containing lead-201 was separated from undesirable thallium radionuclides, which are formed in direct nuclear reactions. The lead fraction was extracted to accumulate thallium-201, and it was separated from lead mocroquantity. The target was dissolved in the nitric acid. The 1st method differs from the 2nd one by the fact that before thallium-201 extraction, lead was precipitaed by the nitric acid. The 1st method permits to separate thallium-201 with chemical yield not less than 90 %, the 2nd one - ≥95 %. 2 refs

  19. Gammatography of thick lead vessels

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Sundaram, V.M.

    1979-01-01

    Radiography, scintillation and GM counting and dose measurements using ionisation chamber equipment are commonly used for detecting flaws/voids in materials. The first method is mostly used for steel vessels and to a lesser extent thin lead vessels also and is essentially qualitative. Dose measuring techniques are used for very thick and large lead vessels for which high strength radioactive sources are required, with its inherent handling problems. For vessels of intermediate thicknesses, it is ideal to use a small strength source and a GM or scintillation counter assembly. At the Reactor Research Centre, Kalpakkam, such a system was used for checking three lead vessels of thicknesses varying from 38mm to 65mm. The tolerances specified were +- 4% variation in lead thickness. The measurements also revealed the non concentricity of one vessel which had a thickness varying from 38mm to 44mm. The second vessel was patently non-concentric and the dimensional variation was truly reproduced in the measurements. A third vessel was fabricated with careful control of dimensions and the measurements exhibited good concentricity. Small deviations were observed, attributable to imperfect bondings between steel and lead. This technique has the following advantages: (a) weaker sources used result in less handling problems reducing the personnel exposures considerably; (b) the sensitivity of the instrument is quite good because of better statistics; (c) the time required for scanning a small vessel is more, but a judicious use of a scintillometer for initial fast scan will help in reducing the total scanning time; (d) this method can take advantage of the dimensional variations themselves to get the calibration and to estimate the deviations from specified tolerances. (auth.)

  20. Relational Perspectives on Leading

    DEFF Research Database (Denmark)

    Relational Perspectives on Leading discusses leadership from a relational and social constructionism perspective as practiced on an everyday basis between people. The book pursues a fast growing, practice-based approach - particularly within the Anglo-Saxon parts of the world - to organization...

  1. Learn about Lead

    Science.gov (United States)

    ... Search Main menu Environmental Topics Air Bed Bugs Chemicals and Toxics Environmental Information by Location Greener Living Health Land, ... it has some beneficial uses, it can be toxic to humans and animals causing of health ... some types of industrial facilities, and past use of lead-based paint ...

  2. Leading Causes of Blindness

    Science.gov (United States)

    ... have cataracts. They are the leading cause of blindness in the world. By age 80, more than half of all people in the United States either will have a cataract or have had cataract surgery. Common symptoms are: Blurry vision Colors that seem faded Glare Not being able to ...

  3. Lead User Innovation

    DEFF Research Database (Denmark)

    Brem, Alexander; Larsen, Henry

    2015-01-01

    covers the opposite view, where a company actively searches and involves lead users, however, with limited success also. Based on both cases, we analyze how, in these emerging processes of relating, meaning is co-created in a way that narrows the shared conceptual space for imagination and collaboration...

  4. Girls Leading Outward

    Science.gov (United States)

    Hamed, Heather; Reyes, Jazmin; Moceri, Dominic C.; Morana, Laura; Elias, Maurice J.

    2011-01-01

    The authors describe a program implemented in Red Bank Middle School in New Jersey to help at-risk, minority middle school girls realize their leadership potential. The GLO (Girls Leading Outward) program was developed by the Developing Safe and Civil Schools Project at Rutgers University and is facilitated by university students. Selected middle…

  5. Leading through Conflict

    Science.gov (United States)

    Gerzon, Mark

    2006-01-01

    This article talks about leading significant learning opportunities through conflict of ideas in a school system. Catalyzing school change can turn emotional differences of opinion into learning opportunities. Leaders who want to deal effectively with these challenging, often tense situations need to be more than good managers. They need to be…

  6. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    1979, the number of titanium fabrications dropped from 16 to 4, primarily because of the sponge shortage and EPA and OSHA requirements. Non-military...East - Taiwan, Korea, Singapore, Malaysia and Hong Kong. In addition, a significant amount of ceramic parts, lead frames and high technology

  7. Lead pollution in Islamabad

    International Nuclear Information System (INIS)

    Mohammad, D.; Khatoon, N.; Ishaque, M.; Ahmed, I.

    1997-01-01

    Lead pollution of urban area emanating from the vehicular exhaust alone is being labeled as one of the worst form of environmental degradation attracting our attention for remediation. For factual assessment samples were collected from different areas of Islamabad. These samples consisted of tree scrapings / peelings, which were dried and ground before undertaking analysis for the lead content. The samples were digested with an acid mixture to remove the organic matter and analyzed using GFAAS technique. A total of 81 samples have been analyzed. The results sowed a lead content varying in the range of 8-474 Mu g g/sup -1/) and 23 samples with Pb content <50 Mu g g-1 (8.0-50.0 Mu g g/sup -1/). Most of the samples also contained some growth which consisted of bacterial, algae and fugal cells and the results have been explained on the basis of Pb absorption by these cells. The procedure followed in this study is recommended for evaluation of lead pollution in urban areas. (author)

  8. EFFECT OF LEAD ACETATE

    African Journals Online (AJOL)

    MICROSOFT

    increase in the production of poultry meat at a reasonable cost (Alam et al., ...... 36(4): 537-541. Taggart MA, Figuerola J, Green AJ, Mateo R, Deacon C, Osborn D, ... selenium, lead and copper levels in the livers and bones of five waterfowl ...

  9. Intoxication for lead

    International Nuclear Information System (INIS)

    Velez, Ruben Dario; Tamayo, Margarita Maria

    1999-01-01

    We present a case of a hospitalized girl with bronchopneumonia, who needed mechanic ventilation. Also she had a developmental delay and Burtons border in gums. Radiological studies showed dense transverse metaphiseal bands in long bones and hyperdensity in basal ganglia. We found high serum lead levels

  10. Lead Thickness Measurements

    International Nuclear Information System (INIS)

    Rucinski, R.

    1998-01-01

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in 3 , an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  11. Anatomy of lead poisoning

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    Results: The primary form of lead toxicity is by oxidative stress mechanisms, apoptosis and necrosis involving ... néfastes sur la reproduction à l'avenir. Résultats:La forme ... prostate cancers, abnormal sexual ..... ensure this work is a success.

  12. Scientometry Leading us Astray

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal

    2010-01-01

    Roč. 2010, č. 82 (2010), s. 8-8 ISSN 0926-4981 Institutional research plan: CEZ:AV0Z10750506 Keywords : scientometry Subject RIV: BD - Theory of Information http://ercim-news.ercim.eu/en82/european-scene/ scientometry -leading-us-astray

  13. Total contribution of airborne lead to blood lead.

    OpenAIRE

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone.

  14. Total contribution of airborne lead to blood lead.

    Science.gov (United States)

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone. PMID:3970881

  15. Association of Lead Levels and Cerebral Palsy

    Science.gov (United States)

    Bansal, Neha; Aggarwal, Anju; Faridi, M. M. A.; Sharma, Tusha; Baneerjee, B. D.

    2017-01-01

    Background: Cerebral palsy is a common motor disability in childhood. Raised lead levels affect cognition. Children with cerebral palsy may have raised lead levels, further impairing their residual cognitive motor and behavioral abilities. Environmental exposure and abnormal eating habits may lead to increased lead levels. Aims and Objectives: To measure blood lead levels in children with cerebral palsy and compare them with healthy neurologically normal children. To correlate blood lead levels with environmental factors. Material and Methods: Design: Prospective case-control study. Setting: Tertiary care hospital. Participants: Cases comprised 34 children with cerebral palsy, and controls comprised 34 neurologically normal, age- and sex-matched children. Methods: Clinical and demographic details were recorded as per proforma. Detailed environmental history was recorded to know the source of exposure to lead. These children were investigated and treated as per protocol. Venous blood was collected in ethylenediaminetetraacetic acid vials for analysis of blood lead levels. Lead levels were estimated by Schimadzu Flame AA-6800 (atomic absorption spectrophotometer). Data were analyzed using SPSS version 17. P pica were 12.33 ± 10.02 µg/dL in comparison to children with no history of pica, 6.70 ± 4.60 µg/dL (P = .029). No correlation was found between hemoglobin and blood lead levels in cases and controls. Conclusion: In our study, blood lead levels are raised in children with cerebral palsy. However, further studies are required to show effects of raised levels in these children. PMID:28491920

  16. Safety and Health Topics: Lead

    Science.gov (United States)

    ... ammunition, pipes, cable covering, building material, solder, radiation shielding, collapsible tubes, and fishing weights. Lead is also ... lead linings in tanks and radiation protection, leaded glass, work involving soldering, and other work involving lead ...

  17. Lead poisoning: The invisible disease

    Science.gov (United States)

    Friend, Milton

    1989-01-01

    Lead poisoning is an intoxication resulting from absorption of hazardous levels of lead into body tissues. Lead pellets from shot shells, when ingested, are the most common source of lead poisoning in migratory birds. Other far less common sources include lead fishing sinkers, mine wastes, paint pigments, bullets, and other lead objects that are swallowed.

  18. Lead toxicity: current concerns.

    OpenAIRE

    Goyer, R A

    1993-01-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has be...

  19. CMS lead tungstate crystals

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    These crystals are made from lead tungstate, a crystal that is as clear as glass yet with nearly four times the density. They have been produced in Russia to be used as scintillators in the electromagnetic calorimeter on the CMS experiment, part of the LHC project at CERN. When an electron, positron or photon passes through the calorimeter it will cause a cascade of particles that will then be absorbed by these scintillating crystals, allowing the particle's energy to be measured.

  20. Leading change: 3--implementation.

    Science.gov (United States)

    Kerridge, Joanna

    The potential for all staff to contribute to service improvement, irrespective of discipline, role or function, is outlined in the 2011 NHS leadership framework. This advocates developing the skills of the entire workforce to create a climate of continuous service improvement. As nurses are often required to take the lead in managing change in clinical practice, this final article in a three-part series focuses on implementing ande potentia reviewing change.

  1. Deaths: Leading Causes for 2015.

    Science.gov (United States)

    Heron, Melonie

    2017-11-01

    Objectives-This report presents final 2015 data on the 10 leading causes of death in the United States by age, sex, race, and Hispanic origin. Leading causes of infant, neonatal, and postneonatal death are also presented. This report supplements "Deaths: Final Data for 2015," the National Center for Health Statistics' annual report of final mortality statistics. Methods-Data in this report are based on information from all death certificates filed in the 50 states and the District of Columbia in 2015. Causes of death classified by the International Classification of Diseases, Tenth Revision (ICD-10) are ranked according to the number of deaths assigned to rankable causes. Cause-of-death statistics are based on the underlying cause of death. Results-In 2015, the 10 leading causes of death were, in rank order: Diseases of heart; Malignant neoplasms; Chronic lower respiratory diseases; Accidents (unintentional injuries); Cerebrovascular diseases; Alzheimer's disease; Diabetes mellitus; Influenza and pneumonia; Nephritis, nephrotic syndrome and nephrosis; and Intentional self-harm (suicide). They accounted for 74% of all deaths occurring in the United States. Differences in the rankings are evident by age, sex, race, and Hispanic origin. Leading causes of infant death for 2015 were, in rank order: Congenital malformations, deformations and chromosomal abnormalities; Disorders related to short gestation and low birth weight, not elsewhere classified; Sudden infant death syndrome; Newborn affected by maternal complications of pregnancy; Accidents (unintentional injuries); Newborn affected by complications of placenta, cord and membranes; Bacterial sepsis of newborn; Respiratory distress of newborn; Diseases of the circulatory system; and Neonatal hemorrhage. Important variations in the leading causes of infant death are noted for the neonatal and postneonatal periods. All material appearing in this report is in the public domain and may be reproduced or copied without

  2. Update on Recovering Lead From Scrap Batteries

    Science.gov (United States)

    Cole, E. R.; Lee, A. Y.; Paulson, D. L.

    1985-02-01

    Previous work at the Bureau of Mines Rolla Research Center, U.S. Department of the Interior, resulted in successful development of a bench-scale, combination electrorefining-electrowinning method for recycling lead from scrap batteries by using waste fluosilicic acid (H2SiF6) as electrolyte.1,2 This paper describes larger scale experiments. Prior attempts to electrowin lead failed because large quantities of insoluble lead dioxide were deposited on the anodes at the expense of lead deposition on the cathodes. A major breakthrough was achieved with the discovery that lead dioxide formation at the anodes is prevented by adding a small amount of phosphorus to the electrolyte. The amount of PbO2 formed on the anodes during lead electrowinning was less than 1% of the total lead deposited on the cathodes. This work recently won the prestigious IR·100 award as one of the 100 most significant technological advances of 1984.

  3. Isotopic analysis of bullet lead samples

    International Nuclear Information System (INIS)

    Sankar Das, M.; Venkatasubramanian, V.S.; Sreenivas, K.

    1976-01-01

    The possibility of using the isotopic composition of lead for the identification of bullet lead is investigated. Lead from several spent bullets were converted to lead sulphide and analysed for the isotopic abundances using an MS-7 mass spectrometer. The abundances are measured relative to that for Pb 204 was too small to permit differentiation, while the range of variation of Pb 206 and Pb 207 and the better precision in their analyses permitted differentiating samples from one another. The correlation among the samples examined has been pointed out. The method is complementary to characterisation of bullet leads by the trace element composition. The possibility of using isotopically enriched lead for tagging bullet lead is pointed out. (author)

  4. Specificities of reactor coolant pumps units with lead and lead-bismuth coolant

    International Nuclear Information System (INIS)

    Beznosov, A.V.; Anotonenkov, M.A.; Bokov, P.A.; Baranova, V.S.; Kustov, M.S.

    2009-01-01

    The analysis results of impact of lead and lead-bismuth coolants specific properties on the coolants flow features in flow channels of the main and auxiliary circulating pumps are presented. Impossibility of cavitation initiation in flow channels of vane pumps pumping lead and lead-bismuth coolants was demonstrated. The experimental research results of discontinuity of heavy liquid metal coolant column were presented and conditions of gas cavitation initiation in coolant flow were discussed. Invalidity of traditional calculation methods of water and sodium coolants circulation pumps calculations for lead and lead-bismuth coolants circulation pumps was substantiated [ru

  5. Association of Lead Levels and Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Neha Bansal MD

    2017-03-01

    Full Text Available Background: Cerebral palsy is a common motor disability in childhood. Raised lead levels affect cognition. Children with cerebral palsy may have raised lead levels, further impairing their residual cognitive motor and behavioral abilities. Environmental exposure and abnormal eating habits may lead to increased lead levels. Aims and Objectives: To measure blood lead levels in children with cerebral palsy and compare them with healthy neurologically normal children. To correlate blood lead levels with environmental factors. Material and Methods: Design: Prospective case-control study. Setting: Tertiary care hospital. Participants: Cases comprised 34 children with cerebral palsy, and controls comprised 34 neurologically normal, age- and sex-matched children. Methods: Clinical and demographic details were recorded as per proforma. Detailed environmental history was recorded to know the source of exposure to lead. These children were investigated and treated as per protocol. Venous blood was collected in ethylenediaminetetraacetic acid vials for analysis of blood lead levels. Lead levels were estimated by Schimadzu Flame AA-6800 (atomic absorption spectrophotometer. Data were analyzed using SPSS version 17. P < .05 was taken as significant. Results: Mean blood lead levels were 9.20 ± 8.31 µg/dL in cerebral palsy cases and 2.89 ± 3.04 µg/dL in their controls (P < .001. Among children with cerebral palsy, 19 (55.88% children had blood lead levels ≥5 µg/dL. Lead levels in children with pica were 12.33 ± 10.02 µg/dL in comparison to children with no history of pica, 6.70 ± 4.60 µg/dL (P = .029. No correlation was found between hemoglobin and blood lead levels in cases and controls. Conclusion: In our study, blood lead levels are raised in children with cerebral palsy. However, further studies are required to show effects of raised levels in these children.

  6. Lead exposures from varnished floor refinishing.

    Science.gov (United States)

    Schirmer, Joseph; Havlena, Jeff; Jacobs, David E; Dixon, Sherry; Ikens, Robert

    2012-01-01

    We evaluated the presence of lead in varnish and factors predicting lead exposure from floor refinishing and inexpensive dust suppression control methods. Lead in varnish, settled dust, and air were measured using XRF, laboratory analysis of scrape and wipe samples, and National Institute for Occupational Safety and Health (NIOSH) Method 7300, respectively, during refinishing (n = 35 homes). Data were analyzed using step-wise logistic regression. Compared with federal standards, no lead in varnish samples exceeded 1.0 mg/cm(2), but 52% exceeded 5000 ppm and 70% of settled dust samples after refinishing exceeded 40 μg/ft(2). Refinishing pre-1930 dwellings or stairs predicted high lead dust on floors. Laboratory analysis of lead in varnish was significantly correlated with airborne lead (r = 0.23, p = 0.014). Adding dust collection bags into drum sanders and HEPA vacuums to edgers and buffers reduced mean floor lead dust by 8293 μg Pb/ft(2) (pairborne lead exposures to less than 50 μg/m(3). Refinishing varnished surfaces in older housing produces high but controllable lead exposures.

  7. Bromine pretreated chitosan for adsorption of lead

    Indian Academy of Sciences (India)

    Pollution by heavy metals like lead (II) is responsible for health hazards and environmental degradation. Adsorption is a prevalent method applied for removal of heavy metal pollutants from water. This study explored adsorption performances of 30% bromine pretreated chitosan for lead (II) abatement from water. Bromine ...

  8. Lead diffusion in monazite

    International Nuclear Information System (INIS)

    Gardes, E.

    2006-06-01

    Proper knowledge of the diffusion rates of lead in monazite is necessary to understand the U-Th-Pb age anomalies of this mineral, which is one of the most used in geochronology after zircon. Diffusion experiments were performed in NdPO 4 monocrystals and in Nd 0.66 Ca 0.17 Th 0.17 PO 4 polycrystals from Nd 0.66 Pb 0.17 Th 0.17 PO 4 thin films to investigate Pb 2+ + Th 4+ ↔ 2 Nd 3+ and Pb 2+ ↔ Ca 2+ exchanges. Diffusion annealings were run between 1200 and 1500 Celsius degrees, at room pressure, for durations ranging from one hour to one month. The diffusion profiles were analysed using TEM (transmission electronic microscopy) and RBS (Rutherford backscattering spectroscopy). The diffusivities extracted for Pb 2+ + Th 4+ ↔ 2 Nd 3+ exchange follow an Arrhenius law with parameters E equals 509 ± 24 kJ mol -1 and log(D 0 (m 2 s -1 )) equals -3.41 ± 0.77. Preliminary data for Pb 2+ ↔ Ca 2+ exchange are in agreement with this result. The extrapolation of our data to crustal temperatures yields very slow diffusivities. For instance, the time necessary for a 50 μm grain to lose all of its lead at 800 Celsius degrees is greater than the age of the Earth. From these results and other evidence from the literature, we conclude that most of the perturbations in U-Th-Pb ages of monazite cannot be attributed to lead diffusion, but rather to interactions with fluids. (author)

  9. Soft mode of lead zirconate

    International Nuclear Information System (INIS)

    Pan'ko, G.F.; Prisedskij, V.V.; Klimov, V.V.

    1983-01-01

    Anisotropic diffusional scattering of electrons on PbZrO 3 crystal in the temperature range of phase transition has been recorded. As a result of its analysis it has been established that in lead zirconate the rotational vibrational mode G 25 plays the role of soft mode. The experiment is carried out using PbZrO 3 monocrystals in translucent electron microscope EhM-200, operating in the regime of microdiffraction at accelerating voltage of 150 kV and beam current 50 μA; sample preparation is realized using the method of shearing and fragmentation

  10. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  11. Leading change: 2--planning.

    Science.gov (United States)

    Kerridge, Joanna

    National initiatives have outlined the importance of involving frontline staff in service improvement, and the ability to influence and manage change has been identified as an essential skill for delivering new models of care. Nurses often have to take the lead in managing change in clinical practice. The second in a three-part series is designed to help nurses at all levels develop the knowledge and skills to function as change agents within their organisations. This article focuses on planning the change and dealing with resistance.

  12. Leading Change, Adding Value.

    Science.gov (United States)

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View.

  13. Turning lead into gold

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø

    For years the field of entrepreneurship has been blinded by the alchemical promise of turning lead into gold, of finding the ones most likely to become the next Branson, Zuckerberg or Gates. The promise has been created in the midst of political and scientific agendas where certain individuals...... is not to accumulate state or market wealth, but for entrepreneurial skills to become tools towards the liberation of the individual from oppressive systems of control – essentially to add public value rather than economic value. In this presentation I will sketch an anarchist perspective on entrepreneurship, looking...

  14. Does thiosemicarbazide lead nitrate (TSLN) crystal exist?

    OpenAIRE

    Fernandes, R.; Srinivasan, Bikshandarkoil R.

    2016-01-01

    The authors of a recent paper (Optik 125 (2014) 2022-2025) claim to have grown a so called thiosemicarbazide lead nitrate (TSLN) crystal by the slow evaporation method. In this comment we prove that TSLN is actually thiosemicarbazide.

  15. Moveable Leading Edge Device for a Wing

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2013-01-01

    A method and apparatus for managing a flight control surface system. A leading edge section on a wing of an aircraft is extended into a deployed position. A deformable section connects the leading edge section to a trailing section. The deformable section changes from a deformed shape to an original shape when the leading edge section is moved into the deployed position. The leading edge section on the wing is moved from the deployed position to an undeployed position. The deformable section changes to the deformed shape inside of the wing.

  16. Who will lead?

    Science.gov (United States)

    Gustafson, R P; Schlosser, J R

    1997-01-01

    A recent survey conducted by the UCLA Center for Health Services Management and the Physician Executive Practice of Heidrick & Struggles, an executive search firm, sheds light on the emerging physician executive's role. The goal of the research was to identify success factors as a means of evaluating and developing effective industry leaders. Respondents were asked to look at specific skills in relation to nine categories: Communication, leadership, interpersonal skills, self-motivation/management, organizational knowledge, organizational strategy, administrative skills, and thinking. Communication, leadership, and self-motivation/management emerged, in that order, as the three most important success factors for physician executives. An individual's general competencies, work styles, and ability to lead others through organizational restructuring defines his or her appropriateness for managerial positions in the health care industry.

  17. Study on complexed lead and cadmium ions removal from aqueous solutions by means of ion exchange method; Studia nad usuwaniem skompleksowanych jonow olowiu i kadmu z roztworow wodnych metodami jonowymiennymi

    Energy Technology Data Exchange (ETDEWEB)

    Dudzinska, M. [Politechnika Lubelska, Lublin (Poland)

    1992-12-31

    The possibility of simultaneous removal of heavy metal ions and organic chelates from waste water has been studied. The experimental work has been preceded by extensive theoretical considerations and calculations of physico-chemical parameters of the process for model and real waste water systems. The negative influence of the presence of sulfate anions on cadmium and lead complexes removal in ion exchange process has been experimentally proved. In the systems free of sulfate anions or when their concentrations were low, the purification process conducted on Amberlite IRA-68 was very effective for cadmium and lead complexes removal. 112 refs, 78 figs, 15 tabs.

  18. Lead and lead-based alloys as waste matrix materials

    International Nuclear Information System (INIS)

    Arustamov, A.E.; Ojovan, M.I.; Kachalov, M.B.

    1999-01-01

    Metals and alloys with relatively low melting temperatures such as lead and lead-based alloys are considered in Russia as prospective matrices for encapsulation of spent nuclear fuel in containers in preparation for final disposal in underground repositories. Now lead and lead-based alloys are being used for conditioning spent sealed radioactive sources at radioactive waste disposal facilities

  19. Lead poisoning in calves

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, J E

    1964-01-01

    Over a three-year period a farmer lost seven calves in their second month of age. One year ago a tentative diagnosis of rabies was given and a brain was submitted to the Health of Animals Division for examination. No Negri bodies were found. The owner stated that the calves first appeared listless and later exhibited severe nervous signs. Deaths occurred in from one to 24 hours after onset of signs. Appetite and bowel movements were normal. There was no increase in temperature. The calf would lie quietly for an interval, then rise, run down the alley, press against a wall, and go into a convulsion. It acted as if it were in severe pain and during one of the intermittent convulsions, it jumped over a three-foot partition. This calf was sent to the Regional Veterinary Laboratory at Brighton for necropsy. The calf had been dead for 72 hours when submitted to the laboratory. The only gross findings were of mild pleurisy and hemorrhage on the kidney. A tentative diagnosis of lead poisoning was offered and specimens sent to the Division of Pharmacology and Toxicology, Ontario Veterinary College.

  20. Drowning: a leading killer!

    Directory of Open Access Journals (Sweden)

    Nuno Domingos Garrido

    2016-10-01

    Full Text Available Drowning kills at least 372,000 people worldwide every year and is the 3rd leading cause of unintentional death, accounting for 7% of all deaths stemming from accidents (WHO, 2014. Conceptually, “drowning” is a complex and multi-faceted phenomenon, characterized as a chain of events (Bierens, 2006. Drowning is defined as the process of experiencing respiratory impairment from immersion or submersion in liquid. Research on drowning as a phenomenon presents several difficulties - most of all, that global data concerning the number of occurrences are not accurate. Nevertheless, detailed analysis of the registered incidents allows the identification of risk factors of drowning. An in-depth analysis of the risk factors is the basis for the creation of targeted and effective strategies to prevent drowning. Due to variability of situations which could lead to a drowning episode, experts suggest the adoption of a multi-layer prevention model, rather than opting for isolated measures, since no single measure can prevent all deaths and injuries caused by submersion. Among the preventive measures we would like to emphasize instruction in swimming and water safety. So, what does "knowing how to swim" really mean? Some authors define mastery of this competence as swimming a given distance, while others put the emphasis on how this/any given distance is swum (Stallman, Junge, & Blixt, 2008. It has long been realized that there is no contradiction between learning those competencies which make a person less susceptible to drowning and those competencies which prepare the path towards higher levels of performance and competition. Aquatic movement researchers and practitioners and drowning prevention researchers and practitioners, share in the responsibility for drowning prevention though they are often unaware of it. The question “What should be taught to children?” is too infrequently asked. There remains great variation in what is taught and programs

  1. Cadmium, lead and silver adsorption in hydrous niobium oxide(V) prepared by precipitation in homogeneous solution method; Adsorcao de chumbo, cadmio e prata em oxido de niobio(V) hidratado preparado pelo metodo da precipitacao em solucao homogenea

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferro, Geronimo V.; Pereira, Paulo Henrique F.; Rodrigues, Liana Alvares; Silva, Maria Lucia Caetano Pinto da, E-mail: fernandes_eng@yahoo.com.b [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica

    2011-07-01

    This paper describes the adsorption of heavy metals ions from aqueous solution by hydrous niobium oxide. Three heavy metals were selected for this study: cadmium, lead and silver. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacity (Q{sub 0}) for Pb{sup 2+}, Ag{sup +} and Cd{sup 2+} was found to be 452.5, 188.68 and 8.85 mg g{sup -1}, respectively. (author)

  2. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM); Metodo de evaluacion de dosis por ingestion de polonio, bismuto y plomo como materiales radiactivos naturales

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier, E-mail: vpenam@ullal.edu.co, E-mail: japuerta@unal.edu.co, E-mail: jmorales@unal.cdu.co [Universidad Nacional de Colombia, Medellin (Colombia). Grupo de Fisica Radiologica

    2013-07-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption.

  3. Manurial properties of lead nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R A

    1924-01-01

    Water culture, pot and field experiments were conducted in order to determine the toxic and stimulating limit of lead nitrate in solution. Oats and rye grass were evaluated for evidence of lead poisoning. Results indicate that except in solutions of fairly high concentration, soil adsorbs the lead and destroys the toxicity of soluble lead salts. There was evidence to show that the addition of lead salts increased the rate of nitrification in soil.

  4. Leading Public Design

    DEFF Research Database (Denmark)

    Bason, Christian

    at all levels have taken up a variety of approaches inspired by the field of design, often in response to growing pressures to innovate. But how these approaches influence public innovation – how they change the roles of public managers, how they help managers generate new ideas and solutions...... – and whether, as some have suggested, they might signal the rise of new governance models or paradigms – these issues have not, with perhaps a few exceptions, been rigorously explored. In this thesis, I explore these issues by examining the experiences of public managers who have pioneered the use of design...... approaches. More specifically, I confront three questions: • Characterizing design practice: Within public sector organizations, what does the application of design approaches entail? Why do public managers look to and commission design, and what tools, techniques, processes and methods are brought into play...

  5. Leading with charisma

    Directory of Open Access Journals (Sweden)

    Avbar

    2014-06-01

    Full Text Available Research Question (RQ: Human potential has endless possibilities. Can charisma be taught? What else makes a leader charismatic in the eyes of the followers? Purpose: Purpose and goal of this research paper is to investigate if charisma is human potential that can be learned so leaders could use it to help the population in situations like crisis. We would like to confirm, that charisma is a capability and trait, which can be developed by who ever decides to do so. Method: A descriptive approach was used to examine the theoretical content. Results: To be charismatic means to influence others, connect with them, evoke trust. Charisma is efficient if the leader knows his mission, looks on life difficulties and problems as challenges, is able to be self critic, respects and appreciates others. In the eyes of the followers leader is perceived as charismatic when personal and business vision and goals are established, when present and in control of him/herself and others and in control of the situation. When the leader is showing respect to others and if necessary is decisive and consistent. Organization and society: To unveil the charisma myth, as something god given and unattainable, to the leaders and general public was the aim of this paper. Charisma is not a privilege of some individuals. Leaders have to be aware that it is of most importance to discover this potential and us it for the greater good. Originality: Development of personal charisma is a process, learned from early childhood onwards; some less acquainted with this set of skills can be helped with methods, technique and different approaches. Approaches from various authors are introduced. Limitations/Future Research: This research paper was conducted on articles and books with the key word in title and abstract.

  6. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    International Nuclear Information System (INIS)

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2008-01-01

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g -1 . Linear regression of whole tooth lead (μg g -1 ) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r 2 =0.647 (p -1 , were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g -1 ) on cumulative lead dose (g) yielded a slope of 23 with r 2 =0.961 (p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats

  7. Lead pollution sources and Impacts

    International Nuclear Information System (INIS)

    El-Haggar, S.M.; Saad, S.G.; Saleh, S.K.; El-Kady, M.A.

    1996-01-01

    Despite the medical awareness of lead toxicity, and despite legislation designed to reduce environmental contamination, lead is one of the most widely used heavy metals. Significant human exposure occurs from automobile exhaust fumes, cigarette smoking, lead-based paints and plumbing systems lead spread in the environment can take place in several ways, the most important of which is through the lead compounds released in automobile exhaust as a direct result of the addition of tetraethyl or tetraethyl lead to gasoline as octane boosting agents. Of special is the effect of lead pollution on children, which affects their behavioral and educational attributes considerably. The major channel through through which lead is absorbed is through inhalation of lead compounds in the atmosphere. Lead is a heavy metal characterized its malleability, ductility and poor conduction of electricity. So, it has a wide range of applications ranging from battery manufacturing to glazing ceramics. It is rarely found free in nature but is present in several minerals and compounds. The aim of this paper is to discuss natural and anthropogenic sources of lead together with its distribution and trends with emphasis on egypt. The effects of lead pollution on human health, vegetation and welfare are also presented. It could be concluded that, the excessive release of lead into the environment, especially through the atmosphere, can produce many detrimental and sometimes fatal effects on human, agriculture and zoological life. Besides, it is very plain that there is a serious problem of pollution lead in egypt and specially in cairo. 7 figs

  8. Lead Contamination and Microbial Lead Tolerance in Soils at Major ...

    African Journals Online (AJOL)

    Devika

    ABSTRACT: Lead pollution and lead tolerance levels of microbes in soil at major road junctions in Benin. City were investigated. Results revealed that distance from the road junctions affected the concentrations of lead in soil, as well as the microbial population density and types of microbes present in the soil. The highest ...

  9. Lead Contamination and Microbial Lead Tolerance in Soils at Major ...

    African Journals Online (AJOL)

    Lead pollution and lead tolerance levels of microbes in soil at major road junctions in Benin City were investigated. Results revealed that distance from the road junctions affected the concentrations of lead in soil, as well as the microbial population density and types of microbes present in the soil. The highest concentrations ...

  10. Leaded gasoline - an environmental problem

    International Nuclear Information System (INIS)

    Petrushevska, Ljubica

    2001-01-01

    In the European countries it is a clear trend towards the increasing consumption of unleaded gasolines. Driving force of this trend is, on the one hand the high toxicity of lead compounds and on the other, the necessity of purification of exhaust gases by catalytic converters, for which the lead represent a catalyst poison. In Macedonia, the limit lead content in the leaded gasolines is relatively high (0,6 g/l), as well as the consumption of the leaded gasolines. Rapid and complete transition to unleaded gasolines can be realized by the concept of step by step reduction of lead in our gasolines. (Original)

  11. Experimental lead poisoning in chickens

    Energy Technology Data Exchange (ETDEWEB)

    Silven, L.

    1967-01-01

    Poisoning of water fowl due to the intake of lead shot is not rare in the USA. In order to study this kind of poisoning more closely domestic fowl were given varying amounts of lead shot and lead powder. This treatment did not provoke any symptoms of poisoning. Chemical analyses of different organs, muscles, skeleton and eggs yielded low lead values. It is concluded that the low toxicity of lead administered as lead shot to the domestic fowl is due to a low absorption rate from the gastro-intestinal tract.

  12. Decontamination and coating of lead

    International Nuclear Information System (INIS)

    Rankin, W.N.; Bush, S.P.; Lyon, C.E.; Walker, V.

    1988-01-01

    Technology is being developed to decontaminate lead used in shielding applications in contaminated environments for recycle as shieldings. Technology is also being developed to coat either decontaminated lead or new lead before it is used in contaminated environments. The surface of the coating is expected to be much easier to decontaminate than the original lead surface. If contamination becomes severely embedded in the coating and cannot be removed, it can be easily cut with a knife and removed from the lead. The used coating can be disposed of as radioactive (hot hazardous) waste. The lead can then be recoated for further use as a shielding material

  13. Lead arthropathy: radiographic, CT and MRI findings

    International Nuclear Information System (INIS)

    Fernandes, Joao Luiz; Lopes Rocha, Arthemizio Antonio; Veloso Ayrimoraes Soares, Mayra; Lopes Viana, Sergio

    2007-01-01

    Lead arthropathy is a well-known complication of gunshot injuries with retained intra-articular bullets. Although several previous reports have discussed the radiological findings of this entity, computed tomography (CT) and magnetic resonance imaging (MRI) findings have never been described before in this setting. In this paper the authors review the imaging findings of 11 patients with lead arthropathy (1 of whom had clinical signs of lead poisoning as well), all of them studied by means of radiographs. In addition, non-enhanced CT scans were obtained in 3 patients and gadolinium-enhanced MRI in 1. Classic findings of intra-articular speckled lead deposits (occasionally with a ''lead arthrogram'' appearance), joint space narrowing and preserved bone density were found at radiographs in the great majority of cases. Furthermore, extension of intra-articular lead to adjacent tendon sheaths was observed in almost half of the patients, an observation rarely reported in the literature. CT scans and MRI, in their turn, were superior with regard to soft tissue abnormalities, accurately depicting joint effusion and the thickened synovium with lead particles embedded in it. Post-gadolinium MRI had the advantage of showing the enhancement pattern of the inflamed synovium and associated bone marrow edema pattern. Although it is not possible to establish the role of axial imaging in lead arthropathy from the small number of cases studied, this initial experience shows that both methods hold promise in this setting and may be useful, at least in selected cases. (orig.)

  14. Lead Leached into Water from Select Plumbing Fixtures” Could Lead to Health Hazard

    Directory of Open Access Journals (Sweden)

    Ramsey Coles

    2014-01-01

    Full Text Available Background: Lead is an inert metal and is resistant to corrosion. It also increases tensile strength of many common materials in daily use. Lead was used during the Roman period to transport water (hence the name plumbing/plumber is common terminology even in the present day. Lead enters the biological system through the air, water, and dust. Fine particles of lead, having diameter less than 5 nm are directly absorbed by lungs. Inorganic lead is absorbed by the gastrointestinal tract, and organic lead is absorbed by the skin. Lead has long been known to be a toxic heavy metal and exposure is associated with many deleterious health effects. Still, lead remains a popular ingredient in products ranging from paint to batteries. The lead content in any given material is estimated using various methods. The least cumbersome method is found to be X-Ray Fluorescence technique (XRF. A portable XRF device was used in the present study. Aim: The main aim of this study to investigate whether lead is present in various commonly used plumbing materials. Material and Methods: All types of branded and commonly used pipes were gathered from a market in Bangalore and tested using the XRF machine. In order to evaluate to what extent lead from the pipes could leach into water, seven pipes were randomly selected and filled with Aquafina water (having undetectable level of lead for a 24 hour period. This water was tested at an NABL accredited laboratory in Bangalore, India for lead content. Result: It was determined that lead was present in many of the samples, at an unacceptable levels ranging from, well above the globally accepted level of 0.01 mg/L proof that lead was able to leach from the samples into water. Conclusions: As lead in drinking water represents a direct pathway for human exposure, the authors recommend that significant measures be taken to prevent use of lead in the plumbing industry for prevention of it’s deleterious effects. Authors have also

  15. BLOOD LEAD CONCENTRATION AND DELAYED PUBERTY IN GIRLS

    Science.gov (United States)

    Background Environmental lead exposure has been linked to alterations in growth and endocrine function. It is not known whether such exposure affects pubertal development.Methods We analyzed the relations between blood lead concentration and pubertal...

  16. Non-smooth optimization methods for large-scale problems: applications to mid-term power generation planning

    International Nuclear Information System (INIS)

    Emiel, G.

    2008-01-01

    This manuscript deals with large-scale non-smooth optimization that may typically arise when performing Lagrangian relaxation of difficult problems. This technique is commonly used to tackle mixed-integer linear programming - or large-scale convex problems. For example, a classical approach when dealing with power generation planning problems in a stochastic environment is to perform a Lagrangian relaxation of the coupling constraints of demand. In this approach, a master problem coordinates local subproblems, specific to each generation unit. The master problem deals with a separable non-smooth dual function which can be maximized with, for example, bundle algorithms. In chapter 2, we introduce basic tools of non-smooth analysis and some recent results regarding incremental or inexact instances of non-smooth algorithms. However, in some situations, the dual problem may still be very hard to solve. For instance, when the number of dualized constraints is very large (exponential in the dimension of the primal problem), explicit dualization may no longer be possible or the update of dual variables may fail. In order to reduce the dual dimension, different heuristics were proposed. They involve a separation procedure to dynamically select a restricted set of constraints to be dualized along the iterations. This relax-and-cut type approach has shown its numerical efficiency in many combinatorial problems. In chapter 3, we show Primal-dual convergence of such strategy when using an adapted sub-gradient method for the dual step and under minimal assumptions on the separation procedure. Another limit of Lagrangian relaxation may appear when the dual function is separable in highly numerous or complex sub-functions. In such situation, the computational burden of solving all local subproblems may be preponderant in the whole iterative process. A natural strategy would be here to take full advantage of the dual separable structure, performing a dual iteration after having

  17. Forming lead-based anodes

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnichuk, V I; Voitsekhovich, R I

    1972-01-01

    Lead-based anodes can be produced by forming a layer of lead dioxide by chemical treatment in a solution of sulfuric acid in potassium permanganate at 80 to 100/sup 0/. The solution is mixed by compressed air. (RWR)

  18. Correlation between some parameters of lead absorption and lead intoxication

    Science.gov (United States)

    Waldron, H. A.

    1971-01-01

    Waldron, H. A. (1971).Brit. J. industr. Med.,28, 195-199. Correlation between some parameters of lead absorption and lead intoxication. Use has been made of data collected over a number of years from workers exposed to a lead hazard in a motor-car factory. The correlations between various parameters of lead absorption and lead intoxication were computed, including blood and urine lead concentrations, urinary coproporphyrin, ALA and PBG concentrations, and haemoglobin concentration. In all, 15 correlation coefficients were calculated, of which only six showed a statistically significant result (i.e., Plead and urine lead (r = 0·38, Plead and coproporphyrin (r = 0·42, Plead and ALA (r = 0·43, Plead and PBG (r = 0·19, P<0·05). PMID:5572689

  19. An Examination of Blood Lead Levels in Thai Nielloware Workers

    OpenAIRE

    Decharat, Somsiri; Kongtip, Pornpimol; Thampoophasiam, Prapin; Thetkathuek, Anamai

    2012-01-01

    Objectives: The objectives of this study were to determine the lead levels in blood samples from nielloware workers, to determine airborne lead levels, to describe the workers’ hygiene behaviors, and to ascertain and describe any correlations between lead levels in blood samples and lead levels in airborne samples. Methods: Blood samples and airborne samples from 45 nielloware workers were collected from nielloware workplaces in Nakhon Sri Thammarat Province, Thailand. Lead levels were det...

  20. Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

    Science.gov (United States)

    Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

    2012-07-01

    Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

  1. Lead poisoning in domestic ducks

    Energy Technology Data Exchange (ETDEWEB)

    Rac, R; Crisp, C S

    1954-05-01

    The death of wild ducks, due to the ingestion of lead shop, occurs frequently and is well documented. This paper discusses the death of domestic ducks due to the ingestion of lead. It describes the symptoms, and pathology of the lead poisoning of a clutch of 11 ducklings which were being raised on a farm in Australia. 3 references, 1 table.

  2. Development of a large volume injection method using a programmed temperature vaporization injector - gas chromatography hyphenated to ICP-MS for the simultaneous determination of mercury, tin and lead species at ultra-trace levels in natural waters.

    Science.gov (United States)

    Terán-Baamonde, J; Bouchet, S; Tessier, E; Amouroux, D

    2018-04-27

    The current EU legislation lays down Environmental Quality Standards (EQS) for 45 priority substances in surface waters; among them levels for (organo)metallic species of Hg, Sn and Pb are set between ng L -1 (for Hg and Sn) and μg L -1 (for Pb). To date, only a few analytical methods can reach these very restrictive limits and there is thus a need for comprehensive methods able to analyze these species down to these levels in natural waters. The aim of this work was to develop an online automated pre-concentration method using large volume injections with a Programmed Temperature Vaporization (PTV) injector fitted with a sorbent packed liner coupled to GC-ICP-MS to further improve the detection limits associated to this well-established method. The influence of several parameters such as the PTV transfer temperature and time, carrier gas flow rate and amount of packing material was investigated. Finally, the maximum volume injected through single or multiple injection modes was optimized to obtain the best compromise between chromatographic resolution and sensitivity. After optimization, very satisfactory results in terms of absolute and methodological detection limits were achieved, down to the pg L -1 level for all species studied. The potential of the method was exemplified by determining the concentrations of organometallic compounds in unpolluted river waters samples from the Adour river basin (SW France) and results were compared with conventional (splitless) GC-ICP-MS. The strength of this analytical method lies in the low detection limits reached for the simultaneous analysis of a wide group of organometallic compounds, and the potential to transfer this method to other gas chromatographic applications with inherent lower sensitivity. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Lead- or Lead-bismuth-cooled fast reactors

    International Nuclear Information System (INIS)

    Bouchter, J.C.; Courouau, J.L.; Dufour, P.; Guidez, J.; Latge, C.; Martinelli, L.; Renault, C.; Rimpault, G.

    2014-01-01

    Lead-cooled fast reactors are one of the 6 concepts retained for the 4. generation of nuclear reactors. So far no lead-cooled reactors have existed in the world except lead-bismuth-cooled reactors in soviet submarines. Some problems linked to the use of the lead-bismuth eutectic appeared but were satisfactorily solved by a more rigorous monitoring of the chemistry of the lead-bismuth coolant. Lead presents various advantages as a coolant: no reactivity with water and the air,a high boiling temperature and low contamination when irradiated. The main asset of the lead-bismuth alloy is the drop of the fusion temperature from 327 C degrees to 125 C degrees. The main drawback of using lead (or lead-bismuth) is its high corrosiveness with metals like iron, chromium and nickel. The high corrosiveness of the coolant implies low flow velocities which means a bigger core and consequently a bigger reactor containment. Different research programs in the world (in Europe, Russia and the USA) are reviewed in the article but it appears that the development of this type of reactor requires technological breakthroughs concerning materials and the resistance to corrosion. Furthermore the concept of lead-cooled reactors seems to be associated to a range of low output power because of the compromise between the size of the reactor and its resistance to earthquakes. (A.C.)

  4. Electrical properties of a novel lead alkoxide precursor: Lead glycolate

    International Nuclear Information System (INIS)

    Tangboriboon, Nuchnapa; Pakdeewanishsukho, Kittikhun; Jamieson, Alexander; Sirivat, Anuvat; Wongkasemjit, Sujitra

    2006-01-01

    The reaction of lead acetate trihydrate Pb(CH 3 COO) 2 .3H 2 O and ethylene glycol, using triethylenetetramine (TETA) as a catalyst, provides in one step access to a polymer-like precursor of lead glycolate [-PbOCH 2 CH 2 O-]. On the basis of high-resolution mass spectroscopy, chemical analysis composition, FTIR, 13 C-solid state NMR and TGA, the lead glycolate precursor can be identified as a trimer structure. The FTIR spectrum demonstrates the characteristics of lead glycolate; the peaks at 1086 and 1042 cm -1 can be assigned to the C-O-Pb stretchings. The 13 C-solid state NMR spectrum gives notably only one peak at 68.639 ppm belonging to the ethylene glycol ligand. The phase transformations of lead glycolate and lead acetate trihydrate to lead oxide, their microstructures, and electrical properties were found to vary with increasing temperature. The lead glycolate precursor has superior electrical properties relative to those of lead acetate trihydrate, suggesting that the lead glycolate precursor can possibly be used as a starting material for producing electrical and semiconducting ceramics, viz. ferroelectric, anti-ferroelectric, and piezoelectric materials

  5. Current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Ishibashi, Kenji

    1989-01-01

    Current leads for superconducting magnets have been studied since 1960's. The technology of current leads may seem to have been established both in theory and experiment before the middle of 1970's. Nevertheless, a wide variety of superconducting magnets have been introduced in the last 15 years, and the demands for special current leads have increased in accordance to the variety. A steady advance has been made in the design theory and fabrication of current leads. This paper describes the recent current lead technology regarding the design theory, safety in accidents, and high current capability. (author)

  6. Presence of lead in opium.

    Science.gov (United States)

    Aghaee-Afshar, Mahmoud; Khazaeli, Payam; Behnam, Behzad; Rezazadehkermani, Mohammad; Ashraf-Ganjooei, Narges

    2008-09-01

    Opium addiction is a common form of addiction in Middle East countries such as Iran. Recently several reports suggested some kinds of pathologic findings such as abdominal pain, nephropathy, and anemia in opium addict patients. Such pathologic findings suggest lead poisoning in the patients. In this study, the concentration of lead in 10 opium samples was evaluated. The mean concentration of lead in the opium samples was 1.88 ppm. This may explain some of the pathologic findings found in addict patients. The authors would suggest further investigations to evaluate the lead concentration in opium addicts' sera and also routine screening for lead poisoning in opium addict patients.

  7. Neurophysiological effects of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, I.; Wildt, K.; Gullberg, B.; Berlin, M.

    1983-10-01

    A series of neurophysiological variables was measured for men occupationally exposed to lead. The results were related to the degree of lead exposure and to the concentrations of lead and zinc protoporphyrin in blood. A small but significant correlation was observed between lead exposure and motor and sensory conduction velocities in the lower limbs, the conduction velocities of slow motor fibers in the upper limbs, and also sensory nerve action potentials. It is suggested that a neurophysiological examination should be considered in the surveillance of the health of lead workers.

  8. INAA, AAS, and lead isotope analysis of ancient lead anchors from the black SEA

    International Nuclear Information System (INIS)

    Kuleff, I.; Djingova, R.; Alexandrova, A.

    1995-01-01

    Lead stock of wooden-lead anchors found along the Bulgarian Black Sea coast and typo logically dated VI c. B.C. - III c. A.D. have been analyzed for chemical composition and lead isotope ratios by INAA, AAS and mass spectrometry. Using multivariate methods for analysis as well as simple bi variate plots the lead for production of the stocks was localized as originating from Laurion, Thassos, Troas, Chalkidike and the Rhodopes. In general, the chemical composition is not recommended to be used for provenance study of lead artefacts. Combining the results from this study with the existing typo logical classification certain conclusion about the production and distribution of lead anchors in the Aegean region are made. (author). 22 refs., 3 figs., 4 tabs

  9. Blood lead and lead-210 origins in residents of Toulouse

    International Nuclear Information System (INIS)

    Servant, J.; Delapart, M.

    1981-01-01

    Blood lead and lead-210 analyses were performed on blood samples from non-smoking residents of Toulouse (city of 400,000 inhabitants). Simultaneous surface soil lead content determinations were carried out by the same procedure on rural zone samples of southwestern France. The observed isotopic ratios were compared in order to evaluate food chain contamination. For an average of 19.7 +- 5.8 μg 100 cc -1 of lead in blood, atmospheric contamination amounts to 20%, estimated as follows: 6% from direct inhalation and 14% from dry deposits on vegetation absorbed as food. The natural levels carried over by the food chain reach 14.9 μg 100 cc -1 and have a 210 Pb/Pb concentration ratio of 0.055 dpmμg -1 . These results lead to a maximum value of 15 μg 100 cc -1 for natural lead in human blood according to the ICRP model. (author)

  10. Experimental Measurement of the Ratio of the Reaction Cross Section (n,2n) for the Natural Mixtures of Lead and Iron Isotopes with 14 MeV Neutrons by the Method of Moderated Neutron-Neutron Coincidences

    International Nuclear Information System (INIS)

    Panteleev, Ts.Ts.; Penchev, O.I.; Trifonov, A.I.; Troshev, T.M.; Christov, V.I.

    1986-01-01

    Neutron data are widely applied in nuclei physics and into practice as well. Data obtained by means of different measurement methods are of interest for increasing the accuracy and reliability of the recommended values for the cross sections of neutron interactions, with substance. The activation analysis method gives a possibility to obtain data about cross section interactions of 14 MeV neutrons with the nuclei σ (n,2n), σ( n,p), σ (n,pn), σ (n,α), etc. A serious shortcoming of this measuring method is the necessity of applying express methods of analysis of induced activities - restrictions connected with the life-times of the reaction products. It is also necessary to comply with the requirements for high accuracy in the data about the decay schemes and the absolute intensities of the γ-transitions in the investigated nuclei. The investigations directly measuring the output of the reaction, products from the targets, placed into the neutron beam, do not possess the shortcomings of the activation method but require serious demands toward the detecting apparatuses (ionization chambers, semiconducting and scintillation detectors, proportional counters, etc.). These demands are connected with the heavy background conditions of work at the beams for measurements of whatever partial cross sections. During the experimental measurements of the reactions by neutron emission for registration, it is necessary to slow them down to thermal energies, since only in this energy interval there exist sufficiently effective without threshold detectors. We have elaborated the experimental set-up allowing to measure the neutron multiplicity in an interaction. In the present work we have also used it for a relative measurement the the reaction cross section σ (n,2n) for Pe and Pb nuclei in their natural isotope mixtures. As it is known, this reaction has an important application for the blanket materials of thermonuclear reactors and for tritium fuel regeneration problem. The

  11. Optimum input leads for cryogenic apparatus

    International Nuclear Information System (INIS)

    Der Nigohossian, G.

    1967-02-01

    The electrical leads used to introduce a current into a cryostat cause a heat influx due to thermal conduction and to Joule heating. It is very important to be able to minimize this flux. Theoretical calculation of optimized leads takes into account the varying heat and electrical conductivities of the leads as well as the heat exchange coefficient with the effluent gas. Practical results have been summarized in different tables which permit for a specific material i.e. copper, aluminium, brass, stainless steel with the intensity and end temperatures being known (i.e. 4,2 or 18,5 deg. K at the cold end; 77,295 or 320 deg. K at the warm end) to deduce the minimum heat flow and the length-cross section ratio of the optimized leads. A general method is indicated, which would allow to solve the same problem for other materials. (author) [fr

  12. Current practice in transvenous lead extraction

    DEFF Research Database (Denmark)

    Bongiorni, Maria Grazia; Blomström-Lundqvist, Carina; Kennergren, Charles

    2012-01-01

    AIM: Current practice with regard to transvenous lead extraction among European implanting centres was analysed by this survey. METHODS AND RESULTS: Among all contacted centres, 164, from 30 countries, declared that they perform transvenous lead extraction and answered 58 questions...... with a compliance rate of 99.9%. Data from the survey show that there seems to be an overall increasing experience of managing various techniques of lead extraction and a widespread involvement of cardiac centres in this treatment. Results and complication rates seem comparable with those of main international...... registries. CONCLUSION: This survey gives an interesting snapshot of lead extraction in Europe today and gives some clues for future research and prospective European registries....

  13. Treating Lead Toxicity: Possibilities beyond Synthetic Chelation

    Directory of Open Access Journals (Sweden)

    Shambhavi Tannir

    2013-01-01

    Full Text Available Lead, a ubiquitous metal, is one of the most abundant elements present on earth. Its easy availability and cost effectiveness made it an extremely popular component in the industrial revolution. However, its hazardous health effects were not considered at the time. Over the last few decades, with the adverse effects of lead coming to the forefront, nations across the world have started to recognize and treat lead toxicity. The most reliable and used method until now has been chelation therapy. Recent research has suggested the use of natural products and sources to treat lead poisoning with minimal or no side effects. This review has tried to summarize a few of the natural products/sources being investigated by various groups.

  14. Lead remediation and changes in human lead exposure: some physiological and biokinetic dimensions.

    Science.gov (United States)

    Mushak, Paul

    2003-02-15

    This paper presents a qualitative and quantitative analysis of the various aspects of lead remediation effectiveness with particular reference to human health risk assessment. One of the key elements of lead remediation efforts at such sites as those under the Superfund program deals with populations at elevated exposure and toxicity risk in the proximity of, or at, the site of remediation, especially remediation workers, workers at other tasks on sites that were remediated down to some action level of lead concentration in soils, and groups at risk in nearby communities. A second element has to do with how one measures or models lead exposure changes with special reference to baseline and post-remediation conditions. Various biomarkers of lead exposure can be employed, but their use requires detailed knowledge of what results using each means. The most commonly used approach is measurement of blood lead (Pb-B). Recognized limitations in the use of Pb-B has led to the use of predictive Pb exposure models, which are less vulnerable to the many behavioral, physiological, and environmental parameters that can distort isolated or 'single shot' Pb-B testings. A third aspect covered in this paper presents various physiological factors that affect the methods by which one evaluates Pb remediation effectiveness. Finally, this article offers an integrated look at how lead remediation actions directed at one lead source or pathway affect the total lead exposure picture for human populations at elevated lead exposure and toxicity risk.

  15. Performance of Lead-Free versus Lead-Based Hunting Ammunition in Ballistic Soap

    Science.gov (United States)

    Gremse, Felix; Krone, Oliver; Thamm, Mirko; Kiessling, Fabian; Tolba, René Hany; Rieger, Siegfried; Gremse, Carl

    2014-01-01

    Background Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. Methods We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. Results All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. Conclusion The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion, deflection angle, cavity shape

  16. Performance of lead-free versus lead-based hunting ammunition in ballistic soap.

    Directory of Open Access Journals (Sweden)

    Felix Gremse

    Full Text Available BACKGROUND: Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. METHODS: We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. RESULTS: All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. CONCLUSION: The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion

  17. Superconducting magnets and leads thereto

    International Nuclear Information System (INIS)

    Biltcliffe, M.N.; Hanley, P.E.; McKinnon, J.B.; Wheatley, R.W.

    1975-01-01

    The magnet described comprises a cryostat containing a superconducting coil for the generation of a magnetic field, with a short-circuiting superconducting link connected across the coil, and electrical leads extending through the cryostat to the coil; these leads are provided with joints within the cryostat to enable them to be detached from the coil and removed from the cryostat without interrupting the current through the coil, thus reducing heat conduction to the cryostat through the leads. The joints are arranged so that the leads can be readily detached and re-attached to the coil from outside the cryostat. Gas-tight seals are provided where the leads pass through the outer wall of the cryostat, with caps that can be secured after removal of the leads. This kind of magnet can provide a stable magnetic field continuously over long periods, such as is required in nuclear magnetic resonance spectrometers. (U.K.)

  18. Leading education professionals: Local, connected, and artful

    NARCIS (Netherlands)

    Bathurst, R.; van Gelderen, M.W.

    2014-01-01

    In this paper, we explore the work life of a scholar new to academia in her methods of leading informally. We discuss five vignettes that offer moments of learning and reflection, including reducing performance anxiety, privileging financial accountability, the rise of the virtual world, the impact

  19. Electronic and optical properties of lead iodide

    DEFF Research Database (Denmark)

    Ahuja, R.; Arwin, H.; Ferreira da Silva, A.

    2002-01-01

    The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...

  20. Taking the Lead : Gender, Social Context and Preference to Lead

    NARCIS (Netherlands)

    Hong, A.P.C.I.; Schaafsma, J.; van der Wijst, P.J.

    2014-01-01

    Previous research has demonstrated that women tend to emerge as leaders less often than men. In the present study, we examined to what extent women's and men's preference to lead is influenced by social context. It was hypothesized that women have a less strong preference to lead than men in a

  1. 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.

  2. Safe leads and lead changes in competitive team sports

    Science.gov (United States)

    Clauset, A.; Kogan, M.; Redner, S.

    2015-06-01

    We investigate the time evolution of lead changes within individual games of competitive team sports. Exploiting ideas from the theory of random walks, the number of lead changes within a single game follows a Gaussian distribution. We show that the probability that the last lead change and the time of the largest lead size are governed by the same arcsine law, a bimodal distribution that diverges at the start and at the end of the game. We also determine the probability that a given lead is "safe" as a function of its size L and game time t . Our predictions generally agree with comprehensive data on more than 1.25 million scoring events in roughly 40 000 games across four professional or semiprofessional team sports, and are more accurate than popular heuristics currently used in sports analytics.

  3. Identification of genomic differences between Campylobacter jejuni subsp. jejuni and C. jejuni subsp. doylei at the nap locus leads to the development of a C. jejuni subspeciation multiplex PCR method

    Directory of Open Access Journals (Sweden)

    Heath Sekou

    2007-02-01

    Full Text Available Abstract Background The human bacterial pathogen Campylobacter jejuni contains two subspecies: C. jejuni subsp. jejuni (Cjj and C. jejuni subsp. doylei (Cjd. Although Cjd strains are isolated infrequently in many parts of the world, they are obtained primarily from human clinical samples and result in an unusual clinical symptomatology in that, in addition to gastroenteritis, they are associated often with bacteremia. In this study, we describe a novel multiplex PCR method, based on the nitrate reductase (nap locus, that can be used to unambiguously subspeciate C. jejuni isolates. Results Internal and flanking napA and napB primer sets were designed, based on existing C. jejuni and Campylobacter coli genome sequences to create two multiplex PCR primer sets, nap mpx1 and nap mpx2. Genomic DNA from 161 C. jejuni subsp. jejuni (Cjj and 27 C. jejuni subsp. doylei (Cjd strains were amplified with these multiplex primer sets. The Cjd strains could be distinguished clearly from the Cjj strains using either nap mpx1 or mpx2. In addition, combination of either nap multiplex method with an existing lpxA speciation multiplex method resulted in the unambiguous and simultaneous speciation and subspeciation of the thermophilic Campylobacters. The Cjd nap amplicons were also sequenced: all Cjd strains tested contained identical 2761 bp deletions in napA and several Cjd strains contained deletions in napB. Conclusion The nap multiplex PCR primer sets are robust and give a 100% discrimination of C. jejuni subspecies. The ability to rapidly subspeciate C. jejuni as well as speciate thermophilic Campylobacter species, most of which are pathogenic in humans, in a single amplification will be of value to clinical laboratories in strain identification and the determination of the environmental source of campylobacterioses caused by Cjd. Finally, the sequences of the Cjd napA and napB loci suggest that Cjd strains arose from a common ancestor, providing clues as to

  4. Neurological aspects of lead intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, H

    1980-05-08

    This study gives a survey over the medical and scientific literature on lead intoxications, which were published until 1979. Neurologic aspects are of particular interest. At present dramatic cases of lead intoxications occur only rarely. However, there are numerous studies about cases of chronical, partly subclinical intoxications. This chronical type of lead intoxication can become manifest clinically as relatively vague symptoms, for example vertigos, insomnia, headaches and weakness. Contrary to this, serious encephalopathies, even with fatal outcome, and polyneuropathies with typical paresis of the radial nerve are preferably observed in acute lead intoxications. Besides the numerous sources of intoxication, also the different opinions found in literature are discussed, concerning the effects of lead on the human body. The fact that there are differing opinions about the limiting value of the blood-lead level at which intoxication symptoms have to be expected, becomes apparent when the determined blood-lead level values are compared and evaluated. Besides the description of general intoxication effects, the discussion of the neurologic aspects found in literature - not only those concerning the central, but also the peripheral system - are preferably concerned. Reports about neuropsychical alterations due to lead exposure, which are mainly found in children, supplement the numerous descriptions of the macroscopic and microscopic alterations of the nervous system provoked by lead. Finally the therapeutic and prophylactic measures given in the literature are discussed.

  5. Lead (Environmental Health Student Portal)

    Science.gov (United States)

    ... Air Pollution Home Indoor Air Pollution Outdoor Air Pollution Particulate Matter Ozone Chemicals Chemicals Home Mercury Lead Arsenic Volatile Organic Compounds Plastics Pesticides Climate Change ...

  6. Enhanced Leads and Appointment System

    Data.gov (United States)

    Social Security Administration — The data asset contains information on current or upcoming appointments, individuals who will be attending the appointment, potential intent to file a claim (lead),...

  7. Lead Poisoning in Wild Birds

    Science.gov (United States)

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  8. In vivo x-ray fluorescence of bone lead in the study of human lead metabolism: Serum lead, whole blood lead, bone lead, and cumulative exposure

    International Nuclear Information System (INIS)

    Cake, K.M.; Chettle, D.R.; Webber, C.E.; Gordon, C.L.

    1995-01-01

    Traditionally, clinical studies of lead's effect on health have relied on blood lead levels to indicate lead exposure. However, this is unsatisfactory because blood lead levels have a half-life of approximately 5 weeks, and thus reflect recent exposure. Over 90% of the lead body burden is in bone, and it is thought to have a long residence time, thus implying that measurements of bone lead reflect cumulative exposure. So, measurements of bone lead are useful in understanding the long-term health effects of lead. Ahlgren reported the first noninvasive measurements of bone lead in humans, where γ-rays from 57 Co were used to excite the K series x-rays of lead. The lead detection system at McMaster University uses a 109 Cd source which is positioned at the center of the detector face (HPGe) and a near backscatter (∼160 degrees) geometry. This arrangement allows great flexibility, since one can sample lead in a range of different bone sites due to a robust normalization technique which eliminates the need to correct for bone geometry, thickness of overlying tissue, and other related factors. The effective radiation dose to an adult during an x-ray fluorescence bone lead measurement is extremely low, being 35 nSv. This paper addresses the issue of how bone, whole blood, and serum lead concentrations can be related in order to understand a person's lead exposure history

  9. Environmental lead exposure among preschool children in Shanghai, China: blood lead levels and risk factors.

    Directory of Open Access Journals (Sweden)

    Jia Cao

    Full Text Available OBJECTIVE: To determine blood lead levels and to identify related risk factors among children in Shanghai; to explore the lead change trend of children after industrial transformation and to provide data for policy development to control environmental lead pollution in Shanghai. METHODS: A stratified-clustered-random sampling method was used. A tungsten atomizer absorption spectrophotometer was employed to determine blood lead levels. RESULTS: The arithmetic mean, geometric mean and median of blood lead levels of 0- to 6-year-old children from Shanghai were 22.49 µg/L, 19.65 µg/L and 19.5 µg/L, including 0.26% (6/2291 with concentrations ≥100 µg/L and 2.7% (61/2291 with concentrations ≥50 µg/L. Boys' levels (23.57 µg/L were greater than those of girls (21.2 µg/L. The blood lead levels increased with age. This survey showed that the Chongming district was the highest and Yangpu district was the lowest, this result is completely opposite with the earlier survey in Shanghai. Risk factors for lead contamination included housing environment, parents' education levels, social status, hobbies, and children's nutritional status. CONCLUSIONS: The blood lead levels of children in Shanghai were lower than the earlier data of Shanghai and those of published studies in China, but higher than the blood lead levels of developed countries. The blood lead levels of urban districts are higher than the central districts with the industrial transformation. Society and the government should take an active interest in childhood lead poisoning of urban areas.

  10. Lead exposure among young urban women

    Directory of Open Access Journals (Sweden)

    Moline Jacqueline M.

    1999-01-01

    Full Text Available Objective. Blood lead levels have declined among every age group in the United States, but urban minority residents remain at disproportionate risk for elevated lead levels. Our objective was to measure lead burden in young women of childbearing age in New York City. We also describe successful means of recruiting this population into a cohort study. Material and methods. Healthy women aged 18-25 attending a New York City health care center in 1995-1998 were eligible for participation. Participants were recruited by health care providers, the study coordinator and the participants themselves. Venous blood samples were obtained for whole blood lead, ferritin and hematocrit measurements, and detailed questionnaires were administered. Results. 239 women have been recruited to date. The population is predominately minority: 62% African-American, 33% Hispanic and 5% Caucasian/Asian. The average age of participants is 19.3 years. Recruitment of participants into the study is predominantly (55% through "word of mouth" from previously enrolled participants. Few participants learned of the study through their health care providers. The mean blood lead level among study participants is 2.1 ± 1.7 µg/dl, which is consistent with the most recent United States national survey. Conclusions. Blood lead levels are low in young, urban minority women of childbearing age in New York City. In this population, recruitment efforts were substantially enhanced with the help of enrolled participants and the health care community.

  11. Topics in perturbative QCD beyond the leading order

    International Nuclear Information System (INIS)

    Buras, A.J.

    1979-08-01

    The basic structure of QCD formulae for various inclusive and semi-inclusive processes is presented. Next to leading order QCD corrections to inclusive deep-inelastic scattering are discussed in some detail. The methods for calculations of QCD corrections (leading, next to leading) to semi-inclusive processes are outlined. Some results of these calculations are discussed. 58 references

  12. Lead poisoning from souvenir earthenware.

    Science.gov (United States)

    Hellström-Lindberg, Eva; Björklund, Andreas; Karlson-Stiber, Christine; Harper, Pauline; Seldén, Anders I

    2006-02-01

    A case of massive lead poisoning from juice contained in a Greek earthenware jug as well as six satellite cases of high lead exposure of similar origin is reported. The intoxicated patient was successfully treated with dimercaptosuccinic acid. Ceramic producers should adhere to the longstanding European legislation.

  13. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  14. Blood Test: Lead (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Blood Test: Lead KidsHealth / For Parents / Blood Test: Lead What's ... español Análisis de sangre: plomo What Is a Blood Test? A blood test is when a sample of ...

  15. Photocatalyzed removal of lead ion from lead-chelator solution

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hyun; Na, Jung Won; Sung, Ki Woung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-07-01

    The present study was undertaken to examine the influence of such chelating agents on the ease and speed of photocatalyzed metal removal and deposition. With excess EDTA, the free EDTA competes with Pb for oxidation, and at a ten fold excess, no lead oxidation (hence removal) occurs. With insufficient EDTA, the corresponding initial concentration of Pb-EDTA is decreased; after its destruction, the remaining Pb{sup 2+} is removed more slowly, at rates found with lead nitrate solution. The net result is that the maximum rate of lead deposition occurs at the stoichiometric ratio of 1:1 EDTA : Pb{sup 2+}.

  16. Distribution of lead in teeth

    Energy Technology Data Exchange (ETDEWEB)

    Fremlin, J H; Tanti-Wipawin, W [Birmingham Univ. (UK). Dept. of Physics

    1976-07-01

    There is currently much concern with the amount of lead in the environment. Measurement of lead in teeth is being used to give information on the integrated uptake of lead by the individual over a period. The distribution of lead within individual teeth, is examined with the object of distinguishing lead deposited during formation or calcification from that taken up by the tooth over its working life after eruption. A tooth is sectioned and bombarded with 30-MeV ions of helium-3 from the Birmingham 1.52-m cyclotron, which produces polonium isotopes. The main useful activity is due to polonium-206, an ..cap alpha.. emitter, half-life 8 d. These ..cap alpha.. particles can be recorded by a plastic solid-state track detector.

  17. Distribution of lead in teeth

    International Nuclear Information System (INIS)

    Fremlin, J.H.; Tanti-Wipawin, W.

    1976-01-01

    There is currently much concern with the amount of lead in the environment. Measurement of lead in teeth is being used to give information on the integrated uptake of lead by the individual over a period. The distribution of lead within individual teeth, is examined with the object of distinguishing lead deposited during formation or calcification from that taken up by the tooth over its working life after eruption. A tooth is sectioned and bombarded with 30-MeV ions of helium-3 from the Birmingham 1.52-m cyclotron, which produces polonium isotopes. The main useful activity is due to polonium-206, an α emitter, half-life 8 d. These α particles can be recorded by a plastic solid-state track detector. (U.K.)

  18. Biosorption of lead phosphates by lead-tolerant bacteria as a mechanism for lead immobilization.

    Science.gov (United States)

    Rodríguez-Sánchez, Viridiana; Guzmán-Moreno, Jesús; Rodríguez-González, Vicente; Flores-de la Torre, Juan Armando; Ramírez-Santoyo, Rosa María; Vidales-Rodríguez, Luz Elena

    2017-08-01

    The study of metal-tolerant bacteria is important for bioremediation of contaminated environments and development of green technologies for material synthesis due to their potential to transform toxic metal ions into less toxic compounds by mechanisms such as reduction, oxidation and/or sequestration. In this study, we report the isolation of seven lead-tolerant bacteria from a metal-contaminated site at Zacatecas, México. The bacteria were identified as members of the Staphylococcus and Bacillus genera by microscopic, biochemical and 16S rDNA analyses. Minimal inhibitory concentration of these isolates was established between 4.5 and 7.0 mM of Pb(NO 3 ) 2 in solid and 1.0-4.0 mM of Pb(NO 3 ) 2 in liquid media. A quantitative analysis of the lead associated to bacterial biomass in growing cultures, revealed that the percentage of lead associated to biomass was between 1 and 37% in the PbT isolates. A mechanism of complexation/biosorption of lead ions as inorganic phosphates (lead hydroxyapatite and pyromorphite) in bacterial biomass, was determined by Fourier transform infrared spectroscopy and X-ray diffraction analyses. Thus, the ability of the lead-tolerant isolates to transform lead ions into stable and highly insoluble lead minerals make them potentially useful for immobilization of lead in mining waste.

  19. Scaling violations beyond the leading order

    CERN Document Server

    Petronzio, R

    1981-01-01

    The authors are concerned with the explicit construction of a method which generalizes beyond leading order the simple probabilistic interpretation of leading scaling violations. The results obtained in this language allow to predict the evolution with the variation of external invariants not only of 'space-like' processes, where the off- shell partons starting the hard interaction have space-like four momenta, like in the case of deep inelastic scattering or Drell-Yan, but also of 'time-like' processes, like the one-particle inclusive e /sup +/e/sup -/ annihilation, where the partons acting in the fragmentation functions have 'time-like' off-shell invariant masses. (9 refs).

  20. Total neutron cross section of lead

    International Nuclear Information System (INIS)

    Kanda, K.; Aizawa, O.

    1976-01-01

    The total thermal-neutron cross section of natural lead under various physical conditions was measured by the transmission method. It became clear that the total cross section at room temperature previously reported is lower than the present data. The total cross section at 400, 500, and 600 0 C, above the melting point of lead, 327 0 C, was also measured, and the changes in the cross section as a function of temperature were examined, especially near and below the melting point. The data obtained for the randomly oriented polycrystalline state at room temperature were in reasonable agreement with the theoretical values calculated by the THRUSH and UNCLE-TOM codes

  1. Structures and electrical properties of Mn- and Co-doped lead-free ferroelectric K0.5Na0.5NbO3 films prepared by a chemical solution deposition method

    International Nuclear Information System (INIS)

    Wang, Lingyan; Ren, Wei; Goh, Phoi Chin; Yao, Kui; Shi, Peng; Wu, Xiaoqing; Yao, Xi

    2013-01-01

    The un-doped, 2 mol% Mn- and 2 mol% Co-doped K 0.5 Na 0.5 NbO 3 (KNN) films were prepared by a chemical solution deposition method. The crystalline phase and surface morphologies of KNN films hardly changed after Mn- and Co-doping. X-ray photoelectron spectrocopy analysis indicates that the introduction of both Mn and Co promoted the formation of KNN perovskite structure, and the most Mn 2+ and Co 2+ ions were oxidized into high-valence ions during thermal process. As a result, the leakage current density of the KNN films was decreased and the electrical properties were enhanced after the doping. - Highlights: • The leakage current density of K 0.5 Na 0.5 NbO 3 (KNN) films decreased after doping • The introduction of dopant promoted the formation of KNN perovskite structure • A portion of introduced doping ions became high-valent after heat-treatment

  2. Childhood lead poisoning investigations: evaluating a portable instrument for testing soil lead.

    Science.gov (United States)

    Reames, Ginger; Lance, Larrie L

    2002-04-01

    The Childhood Lead Poisoning Prevention Branch of the California Department of Health Services evaluated a portable X-ray fluorescence (XRF) instrument for use as a soil lead-testing tool during environmental investigations of lead-poisoned children's homes. A Niton XRF was used to test soil at 119 sampling locations in the yards of 11 San Francisco Bay Area houses. Niton XRF readings were highly correlated with laboratory results and met the study criteria for an acceptable screening method. The data suggest that the most health-protective and time-efficient approach to testing for soil lead above regulatory levels is to take either surface readings or readings of a test cup of soil prepared by grinding with a mortar and pestle. The advantage of the test cup method is that the test cup with soil may be submitted to a laboratory for confirmatory analysis.

  3. NMR measurement of identical polymer samples by round robin method. 4. Analysis of composition and monomer sequence distribution in poly(methyl methacrylate-co-acrylonitrile) leading to determinations of monomer reactivity ratios

    International Nuclear Information System (INIS)

    Hatada, Koichi; Kitayama, Tatsuki; Terawaki, Yoshio

    1995-01-01

    In order to assess the reliability of NMR measurement of polymers, 1 H and 13 C NMR data for three copolymers of methyl methacrylate (MMA) and acrylonitrile (AN) prepared with AIBN were collected from 46 spectrometers whose resonance frequencies for 1 H NMR measurements ranging from 90 to 500 MHz. 1 H and 13 C NMR spectra were measured in nitrobenzene-d 5 at 110degC and acetonitrile-d 3 at 70degC, respectively. Standard deviations (σ's) for chemical shift measurements of the 1 H and 13 C NMR signals were 0.003-0.008 ppm and 0.03-0.05 ppm, respectively. Compositions of the copolymers were determined from the relative intensities of the signals due to the OCH 3 (MMA) and CH (AN) protons, and the σ values for the determinations were 3.7-9.5%. The compositions determined from 13 C NMR (C = O for MMA unit, CN for AN unit) agreed well with those obtained from 1 H NMR. Monomer reactivity ratios r ij (i,j = 1 or 2) for a penultimate model were determined from monomer feed ratios and triad fractions obtained from the C = O (MMA) and CH (AN) carbon signals. Most of the σ values for r ij determinations were 5-14%. While r 22 and r 12 are nearly equivalent, r 11 and r 21 are significantly different from each other, indicating a possible existence of the penultimate-unit effect in the copolymerization of MMA and AN. Terminal model reactivity ratios, r 1 and r 2 , determined formally from the compositions of three samples by Fineman-Ross method showed large σ values (22-24%). (author)

  4. Determination of 210Pb activity concentration in lead shielding

    International Nuclear Information System (INIS)

    Slivka, J.; Mrdja, D.; Varga, E.; Veskovic, M.

    2005-01-01

    210 Pb is concentrated during the separation lead from the ore and therefore it is the main pollutant of lead products. The content of this isotope limits the applicability of lead for low-level shielding of gamma spectrometers. In this paper, a new method for the determination of 210 Pb activity concentration in lead shielding from 46.5 keV gamma line intensity is presented. (author) [sr

  5. Environmental lead hazard to children.

    Science.gov (United States)

    Mittal, S K

    1992-01-01

    Clinically evident lead poisoning is rare in Indian children but is more common than in adults. In children, lead poisoning may appear as fever, seizures, anemia, or abdominal pain, while in adults it is more likely to manifest as chronic minor peripheral neuropathy or gum pigmentation. Children with acute lead poisoning can be treated with chelators such as EDTA and BAL, but many are left with permanent brain damage. The most common sources of acute lead poisoning in Indian children are inhalation of fumes from burned car batteries, ingestion of flaking paint, consuming food cooked in cheap aluminum or brass utensils, and eating contaminated soil. The sources of chronic lead poisoning are water from lead pipes and fumes from industrial or automotive exhaust. Another common source in India is application of "kajjal" to children's eyes. Sources of lead in Western countries, such as drinking water, canned food, residential paint, automotive fuel, and ambient air quality, are regulated by law. None of these are regulated in India.

  6. Collective leadership and safety cultures (Co-Lead): protocol for a mixed-methods pilot evaluation of the impact of a co-designed collective leadership intervention on team performance and safety culture in a hospital group in Ireland.

    Science.gov (United States)

    McAuliffe, Eilish; De Brún, Aoife; Ward, Marie; O'Shea, Marie; Cunningham, Una; O'Donovan, Róisín; McGinley, Sinead; Fitzsimons, John; Corrigan, Siobhán; McDonald, Nick

    2017-11-03

    There is accumulating evidence implicating the role of leadership in system failures that have resulted in a range of errors in healthcare, from misdiagnoses to failures to recognise and respond to patient deterioration. This has led to concerns about traditional hierarchical leadership structures and created an interest in the development of collective ways of working that distribute leadership roles and responsibilities across team members. Such collective leadership approaches have been associated with improved team performance and staff engagement. This research seeks to improve our understanding of collective leadership by addressing two specific issues: (1) Does collective leadership emerge organically (and in what forms) in a newly networked structure? and (2) Is it possible to design and implement collective leadership interventions that enable teams to collectively improve team performance and patient safety? The first phase will include a social network analysis, using an online survey and semistructured interviews at three time points over 12 months, to document the frequency of contact and collaboration between senior hospital management staff in a recently configured hospital group. This study will explore how the network of 11 hospitals is operating and will assess whether collective leadership emerges organically. Second, collective leadership interventions will be co-designed during a series of workshops with healthcare staff, researchers and patient representatives, and then implemented and evaluated with four healthcare teams within the hospital network. A mixed-methods evaluation will explore the impact of the intervention on team effectiveness and team performance indicators to assess whether the intervention is suitable for wider roll-out and evaluation across the hospital group. Favourable ethical opinion has been received from the University College Dublin Research Ethics Committee (HREC-LS-16-116397/LS-16-20). Results will be disseminated

  7. Some studies of maternal and infant lead exposure in Glasgow

    Energy Technology Data Exchange (ETDEWEB)

    Moore, M.R.; Goldberg, A.; Pocock, S.J.; Meredith, A.; Stewart, I.M.; MacAnespie, H.; Lees, R.; Low, A.

    1982-04-01

    In two studies in the city of Glasgow, 236 mothers and their newly born infants and 117 mothers and their 6-weeks old children's environmental lead exposure were examined. In both studies blood lead concentrations were found to correlate significantly with the cube root of the domestic water lead concentrations. In the first study, multiple regression analyses of maternal blood lead and cord blood lead concentrations on other variables showed a significant negative correlation with gestational age. It was also noted that there was an annual fluctuation in maternal blood lead concentration with highest values in the autumn. In the second study, similar relationships were found. Although there was no association between blood lead and sex, age, place of birth or feeding method, as in the previous study, a significant association between social class and blood lead was found. This could be explained on the basis of the significant correlation between water lead and social class. In those mothers who breast fed, breast milk lead concentrations were found to correlate significantly with blood lead concentrations where breast milk lead was around one tenth of blood lead concentration. These studies emphasise the importance of water lead in the economy of environmental lead exposure to mothers and their unborn and newly born infants.

  8. From virtuality to reality - Virtual screening in lead discovery and lead optimization: a medicinal chemistry perspective.

    Science.gov (United States)

    Rester, Ulrich

    2008-07-01

    Drug discovery and development is an interdisciplinary, expensive and time-consuming process. Scientific advancements during the past two decades have altered the way pharmaceutical research produces novel bio-active molecules. Advances in computational techniques and hardware solutions have enabled in silico methods, and in particular virtual screening, to speed up modern lead identification and lead optimization. Recent successes have proven the power of combining virtual screening with complementary and synergistic biophysical methods, such as X-ray crystallography, NMR spectroscopy and isothermal titration calorimetry (ITC). This review addresses key issues, challenges and recent improvements of virtual screening methods and strategies. Examples highlighting the impact of an integrated virtual screening and biophysical characterization platform in the lead identification and optimization process are presented and discussed.

  9. Water quality criteria for lead

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, N.K.

    1987-01-01

    This report is one in a series that establishes water quality criteria for British Columbia. The report sets criteria for lead to protect a number of water uses, including drinking water, freshwater and marine aquatic life, wildlife, livestock, irrigation, and recreation. The criteria are set as either maximum concentrations of total lead that should not be exceeded at any time, or average concentrations that should not be exceeded over a 30-day period. Actual values are summarized.

  10. Chronic lead intoxication in calves

    Energy Technology Data Exchange (ETDEWEB)

    Wagenaar, G

    1963-01-01

    Four calves born in the winter of 1961-1962 died on a farm after a disease which had run its course for periods ranging from six weeks to a few months. A calf had also died showing similar symptoms during the previous year. All calves showed identical symptoms. Initially, their liveliness diminished; subsequently, they drank less and showed signs of pica. They finally died after the disease had run its course for about six weeks. The last calf, born late in February 1962, was in poor health as early as May, improved slightly when it had been sent out to grass but died in September, having fallen ill again in August. Autopsy was performed on three calves; all three were affected with chronic interstitial nephritis and uraemic endocarditis of the left auricle was present as well. The results obtained on toxicological investigation were indicative of lead poisoning. The liver of the calf was found to contain two mg of lead per kg, the cortex of the kidney containing twenty-five mg of lead per kg. These figures did not provide direct evidence of lead poisoning, but in evaluating these figures the fact was taken into account that the calf had no longer been able to ingest any lead for several months. Meanwhile, it was found that the stock-owner had fitted an old painted door in the calf-shed, which door was constantly being licked by the calves. The paint contained 18.6% of lead. This finding was followed by examination of the liver of a calf that had died previously. It was found to contain 49.7 mg of lead per kg. Accordingly, the calves had been affected with a form of lead poisoning running a relatively slow course, as a result of which the animals had developed chronic interstitial nephritis. The calves eventually died from uraemia. 4 references.

  11. Mechanism of lead removal by waste materials

    International Nuclear Information System (INIS)

    Qaiser, S.; Saleemi, A.R.; Ahmed, M.M.

    2007-01-01

    Heavy metal ions are priority pollutants, due to their toxicity and mobility in natural water ecosystems. The discharge of heavy metals into aquatic ecosystems has become a matter of concern in Pakistan over the last few decades. These contaminants are introduced into the aquatic systems significantly as a result of various industrial operations. The metals of concern include lead, chromium, zinc, copper, nickel and uranium. Lead is one of the most hazardous and toxic metals. It is used as industrial raw material in the manufacture of storage batteries, pigments, leaded glass, fuels, photographic materials, matches and explosives. Conventional methods for treatment of dissolved lead include precipitation, adsorption, coagulation/notation, sedimentation, reverse osmosis and ion exchange. Each process has its merits and limitations in applications. Adsorption by activated carbon and ion exchange using commercial ion exchange resins are very expensive processes, especially for a developing country like Pakistan. The present research was conducted to identify some waste materials, which can be utilized to remove lead from industrial wastewater. Natural wastes in the form of leaves and ash have considerable amounts of CaO, MgO, Na/sub 2/O, SiO/sub 2/ and Al/sub 2/O/sub 3/ which can be utilized for precipitation and adsorption. Utilization of waste materials to remove lead from industrial wastewater is the basic theme of this research. The waste materials used in this research were maple leaves, pongamia pinata leaves, coal ash and maple ago leave ash. Parameters studied were reaction time, precipitant dose, pH and temperature. It was found that maple leaves ash has maximum lead removal capacity 19.24 mg g/sup -1/ followed by coal ash 13.2 mg g/sup -1/. The optimal pH was 5 for maple leaves and pongamia Pinata leaves; and 4 for coal ash and maple leaves ash. Removal capacity decreased with increase in temperature. The major removal mechanisms were adsorption and

  12. Supported Lead in Pb-210 Chronology

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, D.; Hettwig, B.; Fischer, H. W. [Institute of Environmental Physics, University of Bremen, Bremen (Germany)

    2013-07-15

    A widely applied method of supported lead estimation in sediments using gamma spectrometric {sup 226}Ra determination via {sup 222}Rn short lived daughter products relies on radioactive equilibrium between {sup 226}Ra and {sup 222}Rn being established after sealing the samples. Advantages and disadvantages of methods of {sup 226}Ra estimation in sediments, using either {sup 222}Rn daughter products or direct estimation by 186.2 keV gamma emissions are discussed. An equilibrium experiment was performed using test samples and in one case radioactive equilibrium was not reached. On a theoretical sediment profile it was shown how systematic errors in supported {sup 210}Pb estimation can lead to incorrect interpretations of {sup 210}Pb{sub xs} profiles and therefore affect {sup 210}Pb derived chronologies. (author)

  13. Spectrochemical determination of lead in wines

    Directory of Open Access Journals (Sweden)

    DRAGAN MARKOVIC

    2000-06-01

    Full Text Available The determination of lead in wines of different origin was performed by means of atomic emission spectroscopy with argon stabilized DC. U-shaped arc and electrothermal atomic absorption spectrometry. The comparison of the results obtained by the direct and standard addition method has indicated the presence of a depressive effect of the complex organic matrix. The effect is avoided successfully by mineralization, as well as by dissolution of the samples. Thus, a relative simple but precise and sensitive method involving the application of a stabilized arc and photoelectric detection with time integration of the emission signals is recommended for the determination of low concentrations of lead in wines. The complex organic matrix was investigated by recording the IR spectra of different wine fractions.

  14. Anemia risk in relation to lead exposure in lead-related manufacturing

    Directory of Open Access Journals (Sweden)

    Nan-Hung Hsieh

    2017-05-01

    Full Text Available Abstract Background Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. Methods We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI. We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Results Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50–1.26 with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67–77% and 86–95% by adopting the suggested BPb standards of 25 and 15 μg/dL. Conclusions We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention.

  15. Lead poisoning after gunshot wound

    Directory of Open Access Journals (Sweden)

    Paulo Roberto de Madureira

    2000-05-01

    Full Text Available CONTEXT: Despite the absence of symptoms in the majority of patients carrying lead bullet fragments in their bodies, there needs to be an awareness of the possible signs and symptoms of lead intoxication when bullets are lodged in large joints like knees, hips and shoulders. Such patients merit closer follow-up, and even surgical procedure for removing the fragments. OBJECTIVE: To describe a patient who developed clinical lead intoxication several years after a gunshot wound. DESIGN: Case report. CASE REPORT: A single white 23-year-old male, regular job as a bricklayer, with a history of chronic alcohol abuse, showed up at the emergency department complaining of abdominal pain with colic, weakness, vomiting and diarrhea with black feces. All the symptoms had a duration of two to three weeks, and had been recurrent for the last two years, with calming during interval periods of two to three weeks. Abdominal radiograms showed a bullet lodged in the left hip, with a neat bursogram of the whole synovial capsule. A course of chelating treatment using calcium versenate (EDTACaNa2 intravenously was started. After the chelation therapy the patient had recurrence of his symptoms and a radical solution for the chronic mobilization of lead was considered. A hip arthroplasty procedure was performed, leading to complete substitution of the left hip.

  16. Lead and Hyperactivity: Lead Levels Among Hyperactive Children

    Science.gov (United States)

    David, Oliver J.; And Others

    1977-01-01

    In the study it is shown that within a group of 84 hyperactive children (4 to 11 years old) those for whom an organic etiology is present have lead burdens lower than in those for whom no apparent cause could be found. (Author/SBH)

  17. Development of an airborne lead analysis kit and its application.

    Science.gov (United States)

    Kongtip, Pornpimol; Borisut, Pornchulee; Yoosook, Witaya; Osiri, Pramuk; Rojanavipart, Piangchan

    2010-11-01

    We developed a method to analyze airborne lead concentrations in the field. It was a modification of the colorimetric method using the reaction between 4(2-pyridylazo)-resorcinol (PAR) and lead with cyanex302 in an acid medium to reduce interfering metals. The lead concentration was detected with a photometer made in Thailand. The developed method uses an impinger containing 1% nitric acid solution as an absorbing agent to collect airborne lead at a flow rate of less than or equal to one liter/minute. Cyanex302 solution in toluene was used to extract metals from the samples and 0.1M nitric acid was used to extract just lead. The lead solution was reacted in 0.5 ml of 0.03% PAR solution, with 1 ml ammonium chloride buffer; the absorption of this solution was measured by a photometer. The results show the limit of detection (LOD) was 0.01 mg/l. The limit of quantification (LOQ) was 0.03 mg/l. The percent recovery of the lead concentrations of 0.05 - 3.0 mg/l was 94.0 to 103.5%. The precision presented as %CV ranged from 0.65 to 10.27%. Lead concentration in a lead smelting factory detected by this method was not significantly different from that detected by the NIOSH method: 7,303 at a 95% confidence level.

  18. How microfluidic methods can lead to better emulsion products

    NARCIS (Netherlands)

    Muijlwijk, Kelly; Berton-Carabin, Claire; Schroën, Karin

    2015-01-01

    Where production lines are judged on their throughput, which is in the order of m3 per hour, interestingly enough the scale at which a lot of phenomena relevant to food structure take place is much smaller: the micro- and nanometre scale. Microfluidics can be used to bridge these

  19. Growth of lead molybdate crystals by vertical Bridgman method

    Indian Academy of Sciences (India)

    Unknown

    The seeds were put in the seed wells, then the feed materials were filled in the cylinder of crucibles. The assembled crucible was sealed in order to prevent the volatilization of the melt during crystal growth. The cru- cible was installed in a refractory tube filled with Al2O3 powder to isolate it from external temperature fluctua-.

  20. Microcirculation in experimental lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Fimiani, R; Silvestroni, A; Iavicoli, N

    1973-01-01

    A study was made of the microvascular system of the auricle of the ear in 15 rabbits to which a 10 percent solution of lead acetate (0.5cm/sup 3//kg) was administered daily for 15 days through the gastric tract. Every 5 days up to the 35th day, determinations of blood and urine lead, free erythrocyte protoporphyrins and urinary coproporphyrins were carried out. Observations of the microvascular system were carried out in basic conditions after 6, 11, 16, 26 and 36 days. On the 6th day there was no pathological finding; on the 11th day small changes of the vascular content were observed, progressively assuming a sludge-like aspect. These findings confirm the hypothesis that the earliest changes caused by lead appear in the vascular content, before parietal changes occur.

  1. Jet calculus beyond leading logarithms

    International Nuclear Information System (INIS)

    Kalinowski, J.; Konishi, K.; Taylor, T.R.

    1981-01-01

    It is shown that the evolution of hadronic jets produced in hard processes can be studied in terms of a simple parton branching picture, beyond the leading log approximation of QCD. The jet calculus is generalized to any given order of logs (but always to all orders of αsub(s)). We discuss the general structure of the formalism. Universality of jet evolution is discussed. We consider also a jet calorimetry measure and the multiplicity distribution of final states in a form which allows a systematic improvement of approximation. To the next-to-leading order, we prove the finiteness and elucidate the scheme dependence of parton subprocess probabilities. The physical inclusive cross section is shown to be scheme independent: next-to-leading results for e + e - → q (nonsinglet) + X agree with those of Curci and others. (orig.)

  2. Initial occupational exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Forni, A.; Cambiaghi, G.; Secchi, G.C.

    1976-01-01

    Serial chromosome and biochemical studies were carried out in 11 subjects before and during initial occupational exposure to moderate quantities of lead fumes in a storage battery plant. The rate of abnormal metaphases, mostly with chromatid and one-break chromosome aberrations, was approximately doubled after one month of work; it further increased after two months of work; remained in this range up to seven months of exposure; and then tended to decrease somewhat. Blood lead levels increased progressively in the first few months, then reached a steady state. Urinary lead and coproporphyrin levels increased sharply after one month of work, while urinary delta-aminolevulinic acid (ALA) levels increased moderately. The ALA dehydratase (ALAD) activity of red blood cells (RBCs) was reduced to almost 50 percent of the initial values after one month, decreased further in subsequent months, and remained decreased through the remainder of the study.

  3. Lead exposure in US worksites: A literature review and development of an occupational lead exposure database from the published literature

    Science.gov (United States)

    Koh, Dong-Hee; Locke, Sarah J.; Chen, Yu-Cheng; Purdue, Mark P.; Friesen, Melissa C.

    2016-01-01

    Background Retrospective exposure assessment of occupational lead exposure in population-based studies requires historical exposure information from many occupations and industries. Methods We reviewed published US exposure monitoring studies to identify lead exposure measurement data. We developed an occupational lead exposure database from the 175 identified papers containing 1,111 sets of lead concentration summary statistics (21% area air, 47% personal air, 32% blood). We also extracted ancillary exposure-related information, including job, industry, task/location, year collected, sampling strategy, control measures in place, and sampling and analytical methods. Results Measurements were published between 1940 and 2010 and represented 27 2-digit standardized industry classification codes. The majority of the measurements were related to lead-based paint work, joining or cutting metal using heat, primary and secondary metal manufacturing, and lead acid battery manufacturing. Conclusions This database can be used in future statistical analyses to characterize differences in lead exposure across time, jobs, and industries. PMID:25968240

  4. Chronic lead intoxication; Chronische Bleiintoxikation

    Energy Technology Data Exchange (ETDEWEB)

    Wieseler, B.; Leng, G. [Duesseldorf Univ. (Germany). Inst. fuer Hygiene; Lenz, S.; Schultz, C. [Klinikum Remscheid GmbH, Remscheid (Germany); Wilhelm, M. [Bochum Univ. (Germany). Inst. fuer Hygiene, Sozial- und Umweltmedizin

    1999-02-01

    The case of a female 68 years old patient is described. Here, a chronic lead intoxication was diagnosed after a two year old medical history with increasing attacks of colic-like abdominal pain often described as life-threatening. After repeated hospitalizations and intensive search for the cause of the symptoms, porphyria and anemia was found to be a sign of a chronic lead poisoning. The blood lead concentrations were always about a level of 600 {mu}g/L. The source of exposure could not be found by now. Neither home inspection nor environmental investigations have shown a recent source of lead intake by the patient. However, a possible occupational source of lead exposure at a blast furnace was established by anamnesis for 1952 to 1962. Thus, osteoporosis induced lead mobilisation was suspected. Noticeable are the results of the six abdominal survey radiographies taken during hospitalization within one year; three radiographies were taken following clinical admission and three before discharge of the patient. In comparison, the course shows a chronic relapsing alimentary supply from metallic particles of unknown genesis. The patient was treated with the sodium salt of 2,3-dimercapto-1-propansulfonic acid (DMPS, Dimaval{sup TM}). She was free of complain afterwards. Following therapy, the blood lead concentrations fell under a level of 400 {mu}m/L, but after several weeks the lead level raised up to the original level of 600 {mu}g/L. (orig.) [Deutsch] Es wird eine 68jaehrige Patientin vorgestellt, bei der nach fast zweijaehriger Krankengeschichte, die gekennzeichnet war durch rezidivierende, teils als lebensbedrohlich geschilderte Bauchkoliken, eine chronische Bleiintoxikation diagnostiziert wurde. Erst nach wiederholten stationaeren Krankenhausaufenthalten mit intensiver Suche nach der Krankheitsursache wurden das Krankheitsbild und die Laborwerte durch Zusatzuntersuchungen ergaenzt, so dass sich in der festgestellten Porphyrie und Anaemie die Diagnose der

  5. Deformation properties of lead isotopes

    International Nuclear Information System (INIS)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

    2016-01-01

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF 0 Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, 180 Pb and 184 Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF 0 functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF 0 functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron-rich lead isotopes undergo

  6. The Analysis on Leading industries in Central Java Province

    Directory of Open Access Journals (Sweden)

    Setyani Irmawati

    2016-06-01

    Full Text Available The purpose of this research is for identifying the types of industriesthat become leading industries in Central Java Province. The methods, used are LQ (SLQ and DLQ and Shift Share. The result of this research shows that the the leading industries in Central Java Province are beverage industry, tobacco processing industry, textile industry, apparel industry, wood industry, printing industry, furniture industry and other processing industries.In the future, the development of the industry should not only focus on the leading industries  but also onnon-leading industries, so that the non leading industries will not be left behind.

  7. Mortality study of lead workers

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, W C; Gaffey, W R

    1975-01-01

    The mortality of 7,032 men employed for one or more years in lead production facilities or battery plants was followed over a 23-year period, 1947-70. Lead absorption in many of these men was greatly in excess of currently accepted standards based upon urinary and blood lead concentrations available for a portion of the group. There were 1,356 deaths reported. The standardized mortality ratio (SMR) for all causes was 107 for smelter workers and 99 for battery plant workers. Death from neoplasms were in slight excess in smelters, but not significantly increased in battery plants. There were no excess deaths from kidney tumors. The SMR for cardiovascular-renal disease was 96 for smelter workers and 101 for battery plant workers. There was definitely no excess in deaths from either stroke or hypertensive heart disease; however, deaths classified as other hypertensive disease and unspecified nephritis or renal sclerosis were higher than expected. The life expectancy of lead workers was calculated to be approximately the same as that of all U.S. males.

  8. High temperature superconductor current leads

    International Nuclear Information System (INIS)

    Zeimetz, B.; Liu, H.K.; Dou, S.X.

    1996-01-01

    Full text: The use of superconductors in high electrical current applications (magnets, transformers, generators etc.) usually requires cooling with liquid Helium, which is very expensive. The superconductor itself produces no heat, and the design of Helium dewars is very advanced. Therefore most of the heat loss, i.e. Helium consumption, comes from the current lead which connects the superconductor with its power source at room temperature. The current lead usually consists of a pair of thick copper wires. The discovery of the High Temperature Superconductors makes it possible to replace a part of the copper with superconducting material. This drastically reduces the heat losses because a) the superconductor generates no resistive heat and b) it is a very poor thermal conductor compared with the copper. In this work silver-sheathed superconducting tapes are used as current lead components. The work comprises both the production of the tapes and the overall design of the leads, in order to a) maximize the current capacity ('critical current') of the superconductor, b) minimize the thermal conductivity of the silver clad, and c) optimize the cooling conditions

  9. Lead apron: room for improvement

    Energy Technology Data Exchange (ETDEWEB)

    Boothroyd, A.E.; Russell, J.G.B.

    1987-02-01

    The amount of red bone marrow not protected by a lead apron was used as an assessment of protection efficiency, and the effect of change of shape was calculated. It was concluded that change of shape would increase protection and cut down cost. (U.K.).

  10. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  11. Copper, lead and zinc production

    International Nuclear Information System (INIS)

    Ayers, J.; Ternan, S.

    2001-01-01

    This chapter provides information on the by-products and residues generated during the production of copper, lead and zinc. The purpose of this chapter is to describe by-products and residues which are generated, how these may be avoided or minimised, and available options for the utilization and management of residues. (author)

  12. Lead-iron phosophate glass

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1988-01-01

    The lead-iron phosphate nuclear waste glasses (LIPNWG) are the subject of the present chapter. They were discovered in 1984 while the authors were attempting to find a sintering aid for certain types of crystalline monazite ceramic high-level nuclear waste forms. In the present chapter, the term waste glass is synonymous with nuclear waste glass (NWG), and the acronym LIP is often used for lead-iron phosphate. Lead-iron phosphate glasses, like many of the previously studied phosphate glasses, are corrosion resistant in aqueous solutions at temperatures below 100 degrees C, and they can be melted and poured at temperatures that are relatively low in comparison with the processing temperatures required for current silicate glass compositions. Unlike the phosphate glasses investigated previously, however, LIPNWGs do not suffer from alteration due to devitrification during realistic and readily, achievable cooling periods. Additionally, lead-iron phosphate glass melts are not nearly as corrosive as the sodium phosphate melts investigated during the 1960s; and, therefore, they can be melted and processed using crucibles made from a variety of materials

  13. Current Leads, Links and Buses

    CERN Document Server

    Ballarino, A

    2014-01-01

    Electrical transfer from a room temperature power source to a superconducting system is done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

  14. Triplet states in lead isotopes

    International Nuclear Information System (INIS)

    Naz, Tabassum; Ahmad, Shakeb; Abusara, H.

    2017-01-01

    Axial and triaxial calculations within RHB have been done to study the shape coexistence phenomena in the lead isotopes. Triplet states have been found in the 184-190 Pb which are in accordance with the experimental and other theoretical observations. The energy difference (in MeV) between the first two excited states also gives the evidence for the same

  15. Implementation Guide: Leading School Change

    Science.gov (United States)

    Whitaker, Todd

    2010-01-01

    This two-part "Implementation Guide" will help to deepen your understanding and sharpen your ability to implement each of the strategies discussed in "Leading School Change: Nine Strategies to Bring Everybody on Board" (ED509821). Part One offers discussion questions and activities which focus on each of the nine strategies. They can be completed…

  16. Lead in calcium supplements (abstract)

    International Nuclear Information System (INIS)

    Rehman, S.; Khalid, N.

    2011-01-01

    Lead present in calcium supplements is of grave concern as some lead levels have been measured up to the extent of regulatory limit set by the United States. Calcium supplements inevitably get contaminated with lead as both are naturally occurring elements. Therefore, it is imperative to indicate its level in these supplements in order to create awareness among consumers. In this study, a sophisticated analytical technique, atomic absorption spectrometry was used to analyze Pb contents in 27 commonly consumed Ca supplements manufactured by different national and multinational companies. The daily intake of lead through these supplements was calculated. Only 10% of the calcium supplements analyzed met the criteria of acceptable Pb levels (1.5 mu g/daily dose) in supplements/consumer products set by the United States. It was also found that Pb intake was highest in chelated calcium supplements 28.5 mu g/daily dose, whereas lowest 0.47 mu g/daily dose through calcium supplements with vitamin D formulation. In order to validate our results from the study conducted, IAEA-certified reference material (animal bone, H-5) was analyzed for its Pb levels. The levels of Pb determined were quite in good agreement with the certified values. (author)

  17. How to lead complex situations

    DEFF Research Database (Denmark)

    Hansen, Michael Pingel

    2013-01-01

    The military leader is experiencing increasingly more complex situations, whether it is as leader in a foreign combat environment or in the home-based public administration. Complex situations like these call for a special set of managerial responses and a special way of leading organisations...

  18. Current Leads, Links and Buses

    Energy Technology Data Exchange (ETDEWEB)

    Ballarino, A [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    Electrical transfer from a room temperature power source to a superconducting system is done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

  19. Leading in a Technological Age

    Science.gov (United States)

    Yadgir, Sheri A.

    2011-01-01

    Technology is advancing more rapidly than at any time in history since the beginning of the Industrial Revolution. In fact, experts say that the world is leaving the Industrial Age of the 20th century and entering an Information Age that will lead into the future. These advances mean that important changes are being made in all areas of life--and…

  20. Effects of occupational lead exposure.

    Science.gov (United States)

    Wang, Y L; Lu, P K; Chen, Z Q; Liang, Y X; Lu, Q M; Pan, Z Q; Shao, M

    1985-01-01

    Fifty-three workers in a battery factory, 52 solderers in a television factory, and 50 embroidery workers (a reference group) were studied. The average air lead levels of the three workplaces were 0.578 mg/m3, 0.002 mg/m3, and 0.001 mg/m3, respectively. Adverse effects in terms of clinical manifestations and biochemical criteria were evident among the battery factory workers. A significant dose-response relationship existed between the toxic effects and the air lead levels. The solderers showed no apparent abnormalities in comparison with the embroidery workers. The early clinical manifestations were dysfunction of the central nervous system, indigestion, arthralgia, and myalgia in the extremities. A positive association was observed between the prevalence of fatigue, mild abdominal pain, and arthralgia and the blood lead (PbB), urinary lead (PbU), and zinc protoporphyrin (ZPP) levels. The symptomatic threshold values of PbB, PbU, and ZPP were 30 micrograms/dl (1.5 mumol/l), 0.045 mg/l (0.2 mumol/l), and 40 micrograms/dl (0.7 mumol/l), respectively. The PbB, PbU, free erythrocyte protoporphyrin, and ZPP levels and the blood aminolevulinic dehydratase ratio could be used as indicators of lead exposure, although ZPP is preferred for a preventive monitoring program. The motor and sensory conduction velocities of the median nerve were slower in the exposed groups than in the reference group. No effects on behavioral function were observed among the solderers.

  1. Deaths: Leading Causes for 2011.

    Science.gov (United States)

    Heron, Melonie

    2015-07-27

    This report presents final 2011 data on the 10 leading causes of death in the United States by age, sex, race, and Hispanic origin. Leading causes of infant, neonatal, and postneonatal death are also presented. This report supplements ‘‘Deaths: Final Data for 2011,’’ the National Center for Health Statistics’ annual report of final mortality statistics. Data in this report are based on information from all death certificates filed in the 50 states and the District of Columbia in 2011. Causes of death classified by the International Classification of Diseases, 10th Revision (ICD–10) are ranked according to the number of deaths assigned to rankable causes. Cause-of-death statistics are based on the underlying cause of death. In 2011, the 10 leading causes of death were, in rank order: Diseases of heart; Malignant neoplasms; Chronic lower respiratory diseases; Cerebrovascular diseases; Accidents (unintentional injuries); Alzheimer’s disease; Diabetes mellitus; Influenza and pneumonia; Nephritis, nephrotic syndrome and nephrosis; and Intentional self-harm (suicide). They accounted for 74% of all deaths occurring in the United States. Differences in the rankings are evident by age, sex, race, and Hispanic origin. Leading causes of infant death for 2011 were, in rank order: Congenital malformations, deformations and chromosomal abnormalities; Disorders related to short gestation and low birth weight, not elsewhere classified; Sudden infant death syndrome; Newborn affected by maternal complications of pregnancy; Accidents (unintentional injuries); Newborn affected by complications of placenta, cord and membranes; Bacterial sepsis of newborn; Respiratory distress of newborn; Diseases of the circulatory system; and Neonatal hemorrhage. Important variations in the leading causes of infant death are noted for the neonatal and postneonatal periods. All material appearing in this report is in the public domain and may be reproduced or copied without permission

  2. Deaths: leading causes for 2010.

    Science.gov (United States)

    Heron, Melonie

    2013-12-20

    This report presents final 2010 data on the 10 leading causes of death in the United States by age, sex, race, and Hispanic origin. Leading causes of infant, neonatal, and postneonatal death are also presented. This report supplements the Division of Vital Statistics' annual report of final mortality statistics. Data in this report are based on information from all death certificates filed in the 50 states and the District of Columbia in 2010. Causes of death classified by the International Classification of Diseases, Tenth Revision (ICD-10) are ranked according to the number of deaths assigned to rankable causes. Cause-of-death statistics are based on the underlying cause of death. In 2010, the 10 leading causes of death were, in rank order: Diseases of heart; Malignant neoplasms; Chronic lower respiratory diseases; Cerebrovascular diseases; Accidents (unintentional injuries); Alzheimer's disease; Diabetes mellitus; Nephritis, nephrotic syndrome and nephrosis; Influenza and pneumonia; and Intentional self-harm (suicide). These 10 causes accounted for 75% of all deaths occurring in the United States. Differences in the rankings are evident by age, sex, race, and Hispanic origin. Leading causes of infant death for 2010 were, in rank order: Congenital malformations, deformations and chromosomal abnormalities; Disorders related to short gestation and low birth weight, not elsewhere classified; Sudden infant death syndrome; Newborn affected by maternal complications of pregnancy; Accidents (unintentional injuries); Newborn affected by complications of placenta, cord and membranes; Bacterial sepsis of newborn; Respiratory distress of newborn; Diseases of the circulatory system; and Necrotizing enterocolitis of newborn. Important variations in the leading causes of infant death are noted for the neonatal and post-neonatal periods. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source

  3. Deaths: Leading Causes for 2013.

    Science.gov (United States)

    Heron, Melonie

    2016-02-16

    This report presents final 2013 data on the 10 leading causes of death in the United States by age, sex, race, and Hispanic origin. Leading causes of infant, neonatal, and postneonatal death are also presented. This report supplements "Deaths: Final Data for 2013," the National Center for Health Statistics’ annual report of final mortality statistics. Data in this report are based on information from all death certificates filed in the 50 states and the District of Columbia in 2013. Causes of death classified by the International Classification of Diseases, Tenth Revision (ICD–10) are ranked according to the number of deaths assigned to rankable causes. Cause-of-death statistics are based on the underlying cause of death. In 2013, the 10 leading causes of death were, in rank order: Diseases of heart; Malignant neoplasms; Chronic lower respiratory diseases; Accidents (unintentional injuries); Cerebrovascular diseases; Alzheimer’s disease; Diabetes mellitus; Influenza and pneumonia; Nephritis, nephrotic syndrome and nephrosis; and Intentional self-harm (suicide). They accounted for 74% of all deaths occurring in the United States. Differences in the rankings are evident by age, sex, race, and Hispanic origin. Leading causes of infant death for 2013 were, in rank order: Congenital malformations, deformations and chromosomal abnormalities; Disorders related to short gestation and low birth weight, not elsewhere classified; Newborn affected by maternal complications of pregnancy; Sudden infant death syndrome; Accidents (unintentional injuries); Newborn affected by complications of placenta, cord and membranes; Bacterial sepsis of newborn; Respiratory distress of newborn; Diseases of the circulatory system; and Neonatal hemorrhage. Important variations in the leading causes of infant death are noted for the neonatal and postneonatal periods. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as

  4. Deaths: Leading Causes for 2012.

    Science.gov (United States)

    Heron, Melonie

    2015-08-31

    This report presents final 2012 data on the 10 leading causes of death in the United States by age, sex, race, and Hispanic origin. Leading causes of infant, neonatal, and postneonatal death are also presented. This report supplements "Deaths: Final Data for 2012," the National Center for Health Statistics' annual report of final mortality statistics. Data in this report are based on information from all death certificates filed in the 50 states and the District of Columbia in 2012. Causes of death classified by the International Classification of Diseases, Tenth Revision (ICD-10) are ranked according to the number of deaths assigned to rankable causes. Cause-of-death statistics are based on the underlying cause of death. In 2012, the 10 leading causes of death were, in rank order: Diseases of heart; Malignant neoplasms; Chronic lower respiratory diseases; Cerebrovascular diseases; Accidents (unintentional injuries); Alzheimer's disease; Diabetes mellitus; Influenza and pneumonia; Nephritis, nephrotic syndrome and nephrosis; and Intentional self-harm (suicide). These causes accounted for 74% of all deaths occurring in the United States. Differences in the rankings are evident by age, sex, race, and Hispanic origin. Leading causes of infant death for 2012 were, in rank order: Congenital malformations, deformations and chromosomal abnormalities; Disorders related to short gestation and low birth weight, not elsewhere classified; Sudden infant death syndrome; Newborn affected by maternal complications of pregnancy; Accidents (unintentional injuries); Newborn affected by complications of placenta, cord and membranes; Bacterial sepsis of newborn; Respiratory distress of newborn; Diseases of the circulatory system; and Neonatal hemorrhage. Important variations in the leading causes of infant death are noted for the neonatal and postneonatal periods.

  5. {beta}-adrenergic receptor density and adenylate cyclase activity in lead-exposed rat brain after cessation of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Huoy-Rou [I-Shou University, Department of Biomedical Engineering, Dashu Shiang, Kaohsiung County (Taiwan); Tsao, Der-An [Fooyin University of Technology, Department of Medical Technology (Taiwan); Yu, Hsin-Su [Taiwan University, Department of Dermatology, College of Medicine (Taiwan); Ho, Chi-Kung [Kaohsiung Medical University, Occupational Medicine (Taiwan); Kaohsiung Medical University, Graduate Institute of Medicine, Research Center for Occupational Disease (Taiwan)

    2005-01-01

    To understanding the reversible or irreversible harm to the {beta}-adrenergic system in the brain of lead-exposed rats, this study sets up an animal model to estimate the change in the sympathetic nervous system of brain after lead exposure was withdrawn. We address the following topics in this study: (a) the relationship between withdrawal time of lead exposure and brain {beta}-adrenergic receptor, blood lead level, and brain lead level in lead-exposed rats after lead exposure was stopped; and (b) the relationship between lead level and {beta}-adrenergic receptor and cyclic AMP (c-AMP) in brain. Wistar rats were chronically fed with 2% lead acetate and water for 2 months. Radioligand binding was assayed by a method that fulfilled strict criteria of {beta}-adrenergic receptor using the ligand [{sup 125}I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The c-AMP level was determined by radioimmunoassay. The results showed a close relationship between decreasing lead levels and increasing numbers of brain {beta}-adrenergic receptors and brain adenylate cyclase activity after lead exposure was withdrawn. The effect of lead exposure on the {beta}-adrenergic system of the brain is a partly reversible condition. (orig.)

  6. All Roads Lead To Rome

    DEFF Research Database (Denmark)

    Ottosen, Thorsten Jørgen; Vomlel, Jiri

    2010-01-01

    . The search methods are made faster by eficient dynamic maintenance of the cliques of a graph. The algorithms are mainly sup- posed to be off-line methods, but they may form the basis for ecient any-time heuristics. Furthermore, the methods make it possible to evaluate the quality of heuristics precisely....

  7. Efficient scanning of thick lead vessels

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Meenakshisundaram, V.

    1978-01-01

    Lead containers fabricated for transport of radioactive materials need to be evaluated for their shielding integrity. The common method of locating a strong gamma source inside the vessel and scanning the external surface by conventional detectors suffers from high radiation dose and low sensitivity. A new method has been proposed and tried. It is found to be more efficient. In the new method, 60 Co source is loaded at the centre of the lead vessel and the outer surface is scanned by NaI(Tl) detector. The transmitted virgin flux is scanned under the 60 Co channel in a single channel analyser. An area of 25 cm 2 is scanned for 10 to 20 seconds each time. The source strength required is considerably reduced by a factor of 10 or more as compared to the common method and external dose rates do not exceed 50 mR/h (130 nC. kg -1 h -1 ) on the vessel surface. The advantages are improved sensitivity, no interference from scattered radiation and assurance in repeatability of measurements. (M.G.B.)

  8. Agroindustrial Waste for Lead and Chromium Biosorption

    Directory of Open Access Journals (Sweden)

    Susana P. Boeykens

    2018-06-01

    Full Text Available There is a need to re-evaluate the residues generated in industrial processes for the production of new raw material, reducing the volume of waste. In this regard, the biosorption is a low-cost alternative method for treating effluents compared to conventional methods. The main objectives of this research were: the evaluation of the biosorbent capacity of six waste materials for the extraction of chromium(VI and lead(II ions from aqueous solutions and, the determination of the adsorption and kinetic parameters for the more efficient system. The materials evaluated were: peanut shell (Arachis hypagaea, sugarcane bagasse (Saccharum officinarum, avocado peel (Persea americana, pecan nutshell (Carya illinoinensis, wheat bran (Triticum aestivum and banana peel (Mussa paradisiaca. The highest percentage of lead removal was obtained with wheat bran (89%. For chromium, the percentage was generally much lower compared with lead for all tested biosorbents, the banana peel being the most efficient with a 10% removal. The models that better describe the adsorption processes were: Langmuir and Freundlich. The pseudo-second order kinetic model allowed obtaining the parameters for both systems. The equilibrium time, in both systems, was reached after 60 minutes. The study of Fourier Transformed Infrared spectra and the results of desorption experiments allowed to hypothesize on the mechanisms involved in the adsorption of these metals.

  9. Lead and Drinking Water from Private Wells

    Science.gov (United States)

    ... type=”submit” value=”Submit” /> Healthy Water Home Lead and Drinking Water from Private Wells Recommend on ... remove lead from my drinking water? What is lead? Lead is a naturally occurring bluish-gray metal ...

  10. Serum Neuron-Specific Enolase, Biogenic Amino-Acids and Neurobehavioral Function in Lead-Exposed Workers from Lead-Acid Battery Manufacturing Process

    OpenAIRE

    K Ravibabu; T Barman; HR Rajmohan

    2015-01-01

    Background: The interaction between serum neuron-specific enolase (NSE), biogenic amino-acids and neurobehavioral function with blood lead levels in workers exposed to lead form lead-acid battery manufacturing process was not studied. Objective: To evaluate serum NSE and biogenic amino-acids (dopamine and serotonin) levels, and neurobehavioral performance among workers exposed to lead from lead-acid storage battery plant, and its relation with blood lead levels (BLLs). Methods: In a c...

  11. Projection Methods

    DEFF Research Database (Denmark)

    Wagner, Falko Jens; Poulsen, Mikael Zebbelin

    1999-01-01

    When trying to solve a DAE problem of high index with more traditional methods, it often causes instability in some of the variables, and finally leads to breakdown of convergence and integration of the solution. This is nicely shown in [ESF98, p. 152 ff.].This chapter will introduce projection...... methods as a way of handling these special problems. It is assumed that we have methods for solving normal ODE systems and index-1 systems....

  12. Lead-elevated activity of xanthine oxidase in lead-exposed workers

    Directory of Open Access Journals (Sweden)

    Sławomir Kasperczyk

    2013-04-01

    Full Text Available Background: The aim of the present study was to explore the connection between lead toxicity and the activity of xanthine oxidase (XO. In addition, we indicated the uric acid (UA and creatinine levels and concentration of erythrocyte malondialdehyde (MDA to estimate oxidative stress intensity. Materials and Methods: The examined group consisted of 125 healthy male employees of zinc and lead works. The examined group was divided into tertiles according to blood lead levels. In the collected blood samples, concentrations of lead-exposure indices, UA, creatinine, and MDA as well as activity of XO were measured concomitantly. The control group consisted of 32 healthy male administrative workers who were exposed to lead only environmentally. Results: XO activity and MDA level were significantly elevated in all tertiles compared to the control group. Creatinine level was significantly elevated in the medium and high tertiles. However, the level of UA was significantly elevated in the high tertile, while in the low and medium tertile only a tendency toward higher values was observed. Conclusions: Occupational exposure to lead induces activity of XO. This induction may contribute to the observed simultaneously increased oxidative stress, measured as MDA level, and the increased level of UA. Med Pr 2013;64(2:175–180

  13. Relational Leading and Dialogic Process

    DEFF Research Database (Denmark)

    Hansen, Lone Hersted

    The Ph.D. thesis contributes to a relational orientation to leading, emphasizing leadership as a shared, collaborative and co-creative activity. In this paradigm major emphasis is put on dialogue and interaction. Inspired by social constructionist ideas, the thesis considers approaches to learning...... and knowledge building as related to relational leading. The practices developed in the thesis research demonstrate that it is possible to create organizational learning and development through collaborative, dialogic practices in groups and teams, for instance combined with the use of roleplaying. In the work...... with the thesis, dialogically based practices inspired by action research with the aim to enhance collaborative knowledge building, reflexivity and dialogical skills in groups and teams were carried out, analyzed and documented. Participants included school principals, leaders of kindergartens, teachers...

  14. Leading Hadron Production at HERA

    Directory of Open Access Journals (Sweden)

    Buniatyan Armen

    2013-06-01

    Full Text Available Data from the recent measurements of very forward baryon and photon production with the H1 and ZEUS detectors at electron-proton collider HERA are presented and compared to the theoretical calculations and Monte Carlo models. Results are presented of the production of leading protons, neutrons and photons in deep inelastic scattering (ep → e' pX, ep → e'nX, ep → e'γX as well as the leading neutron production in the photoproduction of dijets (ep → ejjXn. The forward baryon and photon results from the H1 and ZEUS Experiments are compared also with the models of the hadronic interactions of high energy Cosmic Rays. The sensitivity of the HERA data to the differences between the models is demonstrated.

  15. [Noroviruses: leading cause of gastroenteritis].

    Science.gov (United States)

    Delacour, H; Dubrous, P; Koeck, J L

    2010-04-01

    Although noroviruses were the first viral agents to be linked to gastrointestinal disease, they were long considered a secondary cause far behind rotaviruses. Development of molecular-based diagnostic techniques has provided clearer insight into the epidemiological impact of noroviruses that are now recognized not only as the leading cause of non-bacterial gastroenteritis outbreaks but also as an important cause of sporadic gastroenteritis in both children and adults. Norovirus infection is generally characterized by mild acute vomiting and diarrhea usually lasting for only a few days, but it can lead to more severe and potentially life-threatening symptoms in high-risk groups such as young children, elderly, and immunodeficient persons. It has been demonstrated that they are present in tropical countries. Molecular epidemiological studies have documented the great genetic diversity of noroviruses with regular emergence of variants. Since no vaccine is available, prevention on norovirus infection depends mainly on strict personal and community hygiene measures.

  16. Deformation properties of lead isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E., E-mail: saper43-7@mail.ru [National Research Center Kurchatov Institute (Russian Federation)

    2016-01-15

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF{sup 0} Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, {sup 180}Pb and {sup 184}Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF{sup 0} functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF{sup 0} functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron

  17. String Formation Beyond Leading Colour

    CERN Document Server

    Christiansen, Jesper R.

    2015-08-03

    We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading $N_C$ are allowed to influence the formation of confining potentials (strings). The multiplet structure of $SU(3)$ is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for "baryonic" configurations (e.g., two colours can combine coherently to form an anticolour). In $e^+e^-$collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in $pp$ collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive $1/N_C^2$ suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important $\\left(n_\\mathrm{charged})$ distribution but also with measured rates (and ra...

  18. On the efficiency of a randomized mirror descent algorithm in online optimization problems

    Science.gov (United States)

    Gasnikov, A. V.; Nesterov, Yu. E.; Spokoiny, V. G.

    2015-04-01

    A randomized online version of the mirror descent method is proposed. It differs from the existing versions by the randomization method. Randomization is performed at the stage of the projection of a subgradient of the function being optimized onto the unit simplex rather than at the stage of the computation of a subgradient, which is common practice. As a result, a componentwise subgradient descent with a randomly chosen component is obtained, which admits an online interpretation. This observation, for example, has made it possible to uniformly interpret results on weighting expert decisions and propose the most efficient method for searching for an equilibrium in a zero-sum two-person matrix game with sparse matrix.

  19. Lead and cadmium in food

    International Nuclear Information System (INIS)

    Gliesmann, S.; Kruse, H.; Kriews, M.; Mangels, H.

    1992-08-01

    The amounts of lead and cadmium produced and processed in these days are considerable. As a result, our environment is increasingly polluted by heavy metals and industrial installations, motor vehicles or incinerating plants appear to be among the main culprits here. Air and water are the media permitting the entry of heavy metals into our natural environment where they accumulate in the soil and then gradually migrate into the plants. Their further transport in the food constitutes the third step in the environmental spread of heavy metals. The consumption of muscle and organ meats, of vegetables, fruits, canned food and drinking water is unavoidably associated with some ingestion of lead and cadmium. The degree to which they are taken up and stored in different tissues is determined by absorption properties and the nutritional state of the organism. Cadmium tends to accumulate in the kidneys, lead is mainly stored in the bones. A continuously increasing uptake finally results in health injuries that range from unspecific complaints to damaged kidneys or bones and disorders of liver function. Children and elderly people are at a particular risk here. The level of food contamination is such that screening for heavy metals must be rigorously carried out once appropriate legal thresholds have been set, which ought to be based on proven detrimental effects of lead and cadmium on our health and also take account of infants and children or any other risk groups, where particular caution must be exercised. It should be pointed out that such thresholds have so far not been determined. (orig./MG) [de

  20. Leading Indian Business-Groups

    Directory of Open Access Journals (Sweden)

    Maria Alexandrovna Vorobyeva

    2016-01-01

    Full Text Available The goal of this paper is to investigate the evolution of the leading Indian business-groups under the conditions of economical liberalization. It is shown that the role of modern business-groups in the Indian economy is determined by their high rate in the gross domestic product (GDP, huge overall actives, substantial pert in the e[port of goods and services, as well as by their activities in modern branch structure formatting, and developing labor-intensive and high-tech branches. They strongly influence upon economical national strategies, they became a locomotive of internationalization and of transnationalization of India, the basis of the external economy factor system, the promoters of Indian "economical miracle" on the world scene, and the dynamical segment of economical and social development of modern India. The tendencies of the development of the leading Indian business groups are: gradual concentration of production in few clue sectors, "horizontal" structure, incorporation of the enterprises into joint-stock structure, attraction of hired top-managers and transnationaliziation. But against this background the leading Indian business-groups keep main traditional peculiarities: they mostly still belong to the families of their founders, even today they observe caste or communal relations which are the basis of their non-formal backbone tides, they still remain highly diversificated structures with weak interrelations. Specific national ambivalence and combination of traditions and innovations of the leading Indian business-groups provide their high vitality and stability in the controversial, multiform, overloaded with caste and confessional remains Indian reality. We conclude that in contrast to the dominant opinion transformation of these groups into multisectoral corporations of the western type is far from completion, and in the nearest perspective they will still possess all their peculiarities and incident social and economical

  1. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil

    2010-10-11

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

  2. Tevatron HTS power lead test

    International Nuclear Information System (INIS)

    Feher, S.; Carcagno, R.; Orris, D.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.

    2004-01-01

    Two pairs of ASC 6 kA power leads developed for the Tevatron were successfully tested at Fermilab at over-current conditions. Stable operation was achieved while operating at a current of 9.56 kA for five hours and while continuously ramping between 0-9.56 kA at a ramp rate of 200 A/s for one hour. The minimum required liquid nitrogen flow rate was measured to be 1.5 g/s at 10 kA. After ramping up to 10 kA at 200A/s, it took only 15 minutes to stabilize the upper copper section of the lead with a flow of 1.8 g/s of liquid nitrogen vapor. Testing under extreme operating conditions--270-370 kPa liquid nitrogen vapor pressure and over 0.1 T external magnetic field--demonstrated that the HTS part of the lead can safely operate in the current sharing mode and that this design has large operating margin

  3. The LHC Lead Injector Chain

    CERN Document Server

    Beuret, A; Blas, A; Burkhardt, H; Carli, Christian; Chanel, M; Fowler, A; Gourber-Pace, M; Hancock, S; Hourican, M; Hill, C E; Jowett, John M; Kahle, K; Küchler, D; Lombardi, A M; Mahner, E; Manglunki, Django; Martini, M; Maury, S; Pedersen, F; Raich, U; Rossi, C; Royer, J P; Schindl, Karlheinz; Scrivens, R; Sermeus, L; Shaposhnikova, Elena; Tranquille, G; Vretenar, Maurizio; Zickler, T

    2004-01-01

    A sizeable part of the LHC physics programme foresees lead-lead collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines [1,2]. Each LHC ring will be filled in 10 min by almost 600 bunches, each of 7×107 lead ions. Central to the scheme is the Low Energy Ion Ring (LEIR) [3,4], which transforms long pulses from Linac3 into high-brilliance bunches by means of multi-turn injection, electron cooling and accumulation. Major limitations along the chain, including space charge, intrabeam scattering, vacuum issues and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR involves new magnets and power converters, high-current electron cooling, broadband RF cavities, and a UHV vacuum system with getter (NEG) coatings to achieve a few 10-12 mbar. Major hardware changes in Linac3 and the PS are also covered. An early ion scheme with fewer bunches (but each at nominal...

  4. Mussels (Mytilus sp.) as an indicator of lead pollution

    International Nuclear Information System (INIS)

    Chow, T.J.; Snyder, H.G.; Snyder, C.B.

    1976-01-01

    The lead contents of two species of mussels (Mytilus californianus and M. edulis) collected along the Pacific coast from Piedras Blancas, California to Punta Bnada, Baja California were determined by isotope dilution method. The whole soft parts of the mussels, on a dry weight basis, contained from 0.27 to 42 ppm of lead which can be related to their local habitats. The gill tissues of the mussels showed the highest lead concentration

  5. [Lead poisoning: towards a paleo-epidemiologic re-interpretation?].

    Science.gov (United States)

    Bourdieu, Anne

    2014-01-01

    Lead is a major public health issue. Its use has been increasing since Neolithic times, climaxing in the Ancient Rome and the nineteenth century. Defining the frequency of plumbism before modern times proves to be a difficult matter because of its various and delayed symptoms, and of diagenetic processes affecting bones. After reviewing various methods of lead measurement in bone and tooth, we will expose ways to ascertain lead measurement interpretation in order to estimate the epidemiology of plumbism in ancient times.

  6. Blood lead levels and risk factors for lead poisoning among children in Jakarta, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Albalak, Rachel; Noonan, Gary; Buchanan, Sharunda; Flanders, W. Dana; Gotway-Crawford, Carol; Blumenthal, Wendy; Curtis, Gerald; McGeehin, Michael A. [Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop E-19, Atlanta, GA 30333 (United States); Kim, Dennis; Tan, Regina [Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop D-18, Atlanta, GA 30333 (United States); Jones, Robert L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop F-18, Atlanta, GA 30333 (United States); Sulaiman, Rini [Swisscontact, Jl. Wijaya XII No. 44, Jakarta (Indonesia) 12160

    2003-01-01

    The phase-out of leaded gasoline began in Jakarta, Indonesia on July 1, 2001. We evaluated mean blood lead levels (BLLs) and the prevalence of elevated BLLs of Jakarta school children and assessed risk factors for lead exposure in these children before the beginning of the phase-out activities. The study involved a population-based, cross-sectional blood lead survey that included capillary blood lead sampling and a brief questionnaire on risk factors for lead poisoning. A cluster survey design was used. Forty clusters, defined as primary schools in Jakarta, and 15 2nd- and 3rd-grade children in each cluster were randomly selected for participation in the study. The average age of children in this study was 8.6 years (range 6-12) and the geometric mean BLL of the children was 8.6 {mu}g/dl (median: 8.6 {mu}g/dl; range: 2.6-24.1 {mu}g/dl) (n=397). Thirty-five percent of children had BLLs {>=}10 {mu}g/dl and 2.4% had BLLs {>=}20 {mu}g/dl. Approximately one-fourth of children had BLLs 10-14.9 {mu}g/dl. In multivariate models, level of education of the child's primary caregiver, water collection method, home varnishing and occupational recycling of metals, other than lead, by a family member were predictors of log BLLs after adjustment for age and sex. BLLs of children who lived near a highway or major intersection were significantly higher than those of children who lived near a street with little or no traffic when level of education was not included in the model. Water collection method was a significant predictor of BLLs {>=}10 {mu}g/dl after adjustment for age and sex. BLLs in children in this study were moderately high and consistent with BLLs of children in other countries where leaded gasoline is used. With the phase-out of leaded gasoline, BLLs of children in Jakarta are expected to rapidly decline as they have in other countries that have phased lead out of gasoline.

  7. Determination of Lead in Blood by Atomic Absorption Spectrophotometry1

    Science.gov (United States)

    Selander, Stig; Cramér, Kim

    1968-01-01

    Lead in blood was determined by atomic absorption spectrophotometry, using a wet ashing procedure and a procedure in which the proteins were precipitated with trichloroacetic acid. In both methods the lead was extracted into isobutylmethylketone before measurement, using ammonium pyrrolidine dithiocarbamate as chelator. The simpler precipitation procedure was shown to give results identical with those obtained with the ashing technique. In addition, blood specimens were examined by the precipitation method and by spectral analysis, which method includes wet ashing of the samples, with good agreement. All analyses were done on blood samples from `normal' persons or from lead-exposed workers, and no additions of inorganic lead were made. The relatively simple protein precipitation technique gave accurate results and is suitable for the large-scale control of lead-exposed workers. PMID:5663425

  8. Lead distribution in soils impacted by a secondary lead smelter: Experimental and modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Arnaud R., E-mail: arnaud.schneider@univ-reims.fr [GEGENAA, EA 3795, Université de Reims Champagne-Ardenne, SFR Condorcet FR CNRS 3417, 2 esplanade Roland Garros, 51100 Reims (France); Cancès, Benjamin; Ponthieu, Marie [GEGENAA, EA 3795, Université de Reims Champagne-Ardenne, SFR Condorcet FR CNRS 3417, 2 esplanade Roland Garros, 51100 Reims (France); Sobanska, Sophie [Laboratoire de Spectrochimie IR et Raman, UMR-CNRS 8516, Bât. C5 Université de Lille I, 59655 Villeneuve d' Ascq Cedex (France); Benedetti, Marc F. [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154, CNRS, F-75005 Paris (France); Pourret, Olivier [HydrISE, Institut Polytechnique LaSalle Beauvais, FR-60000 Beauvais (France); Conreux, Alexandra; Calandra, Ivan; Martinet, Blandine; Morvan, Xavier; Gommeaux, Maxime; Marin, Béatrice [GEGENAA, EA 3795, Université de Reims Champagne-Ardenne, SFR Condorcet FR CNRS 3417, 2 esplanade Roland Garros, 51100 Reims (France)

    2016-10-15

    Smelting activities are one of the most common sources of trace elements in the environment. The aim of this study was to determine the lead distribution in upper horizons (0–5 and 5–10 cm) of acidic soils in the vicinity of a lead-acid battery recycling plant in northern France. The combination of chemical methods (sequential extractions), physical methods (Raman microspectroscopy and scanning electron microscopy with an energy dispersive spectrometer) and multi-surface complexation modelling enabled an assessment of the behaviour of Pb. Regardless of the studied soil, none of the Pb-bearing phases commonly identified in similarly polluted environments (e.g., anglesite) were observed. Lead was mainly associated with organic matter and manganese oxides. The association of Pb with these soil constituents can be interpreted as evidence of Pb redistribution in the studied soils following smelter particle deposition. - Highlights: • Lead behavior was studied in smelter impacted soils. • A combination of experimental methods and modelling was employed. • Pb was mainly associated with organic matter and to a lesser degree with Mn oxides. • Pb was redistributed in soils after smelter particle deposition.

  9. Lead distribution in soils impacted by a secondary lead smelter: Experimental and modelling approaches

    International Nuclear Information System (INIS)

    Schneider, Arnaud R.; Cancès, Benjamin; Ponthieu, Marie; Sobanska, Sophie; Benedetti, Marc F.; Pourret, Olivier; Conreux, Alexandra; Calandra, Ivan; Martinet, Blandine; Morvan, Xavier; Gommeaux, Maxime; Marin, Béatrice

    2016-01-01

    Smelting activities are one of the most common sources of trace elements in the environment. The aim of this study was to determine the lead distribution in upper horizons (0–5 and 5–10 cm) of acidic soils in the vicinity of a lead-acid battery recycling plant in northern France. The combination of chemical methods (sequential extractions), physical methods (Raman microspectroscopy and scanning electron microscopy with an energy dispersive spectrometer) and multi-surface complexation modelling enabled an assessment of the behaviour of Pb. Regardless of the studied soil, none of the Pb-bearing phases commonly identified in similarly polluted environments (e.g., anglesite) were observed. Lead was mainly associated with organic matter and manganese oxides. The association of Pb with these soil constituents can be interpreted as evidence of Pb redistribution in the studied soils following smelter particle deposition. - Highlights: • Lead behavior was studied in smelter impacted soils. • A combination of experimental methods and modelling was employed. • Pb was mainly associated with organic matter and to a lesser degree with Mn oxides. • Pb was redistributed in soils after smelter particle deposition.

  10. Natural convection in enclosures containing lead-bismuth and lead

    International Nuclear Information System (INIS)

    Dzodzo, M.; Cuckovic-Dzodzo, D.

    2001-01-01

    The design of liquid metal reactors such as Encapsulated Nuclear Heat Source (ENHS) which are based predominantly on the flow generated by natural convection effects demands knowledge of velocity and temperature fields, distribution of the local Nusselt numbers and values of the average Nusselt numbers for small coolant velocity regimes. Laminar natural convection in rectangular enclosures with different aspect ratios, containing lead-bismuth and lead is studied numerically in this paper. The numerical model takes into account variable properties of the liquid metals. The developed correlation for average Nusselt numbers is presented. It is concluded that average Nusselt numbers are lower than in 'normal' fluids (air, water and glycerol) for the same values of Rayleigh numbers. However, the heat flux, which can be achieved, is greater due to the high thermal conductivity of liquid metals. Some specific features of the flow fields generated by natural convection in liquid metals are presented. Their consequences on the design of heat exchangers for liquid metals are discussed. An application of the obtained results to the design of a new type of steam generator, which integrates the intermediate heat exchanger and secondary pool functions of the ENHS reactor, is presented. (authors)

  11. The Pollution Detectives, Part III: Roadside Lead Pollution.

    Science.gov (United States)

    Sanderson, Phil

    1989-01-01

    Described is a simple test tube method developed lead analysis of samples of roadside soil. The relationship between the results and the traffic flow indicate car exhausts are the major source of lead pollution. Materials and procedures are detailed. An example of results is provided. (Author/CW)

  12. Tellurium self-diffusion and point defects in lead telluride

    International Nuclear Information System (INIS)

    Simirskij, Yu.N.; Firsova, L.P.

    1982-01-01

    Method of radioactive indicators was used to determine factors of tellurium self-diffusion in lead telluride with different deviation of the composition from stoichiometric in the range of enrichment by tellurium. It was found that at 973 K factors of tellurium self-diffusion in lead telluride depend slightly on the vapor pressure of tellurium equilibrium with solid phase

  13. Lagrangian relaxation based algorithm for trigeneration planning with storages

    DEFF Research Database (Denmark)

    Rong, Aiying; Lahdelma, Risto; Luh, Peter

    2008-01-01

    of three energy commodities follows a joint characteristic. This paper presents a Lagrangian relaxation (LR) based algorithm for trigeneration planning with storages based on deflected subgradient optimization method. The trigeneration planning problem is modeled as a linear programming (LP) problem...... an effective method for the long-term planning problem based on the proper strategy to form Lagrangian subproblems and solve the Lagrangian dual (LD) problem based on deflected subgradient optimization method. We also develop a heuristic for restoring feasibility from the LD solution. Numerical results based...

  14. All roads lead to Rome

    DEFF Research Database (Denmark)

    Ottosen, Thorsten Jørgen; Vomlel, Jiri

    2012-01-01

    size triangulations. The search methods are made faster by efficient dynamic maintenance of the cliques of a graph. This problem was investigated by Stix, and in this paper we derive a new simple method based on the Bron-Kerbosch algorithm that compares favourably to Stix’ approach. The new approach...

  15. Determination of lead and cadmium in biological materials

    International Nuclear Information System (INIS)

    Stoeppler, M.; Backhaus, F.; Dahl, R.; Hagedorn-Goetz, H.; Hilpert, K.; Klahre, P.; Rutzel, H.; Valenta, P.; Nuernberg, H.W.; Dumont, M.

    1975-01-01

    Sampling techniques and experience, and decomposition methods are presented. The processes used in flameless atomic absorption spectrometry (including the method using automatic insertion of samples), pulse polarography and isotope dilution mass spectrometry are described. Finally, the results of lead and cadmium measurements in bovine liver, blood, urine and hair samples are reported and discussed with a comparison of methods in some cases

  16. Correlations in particle production in proton-lead and lead-lead collisions at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00361447

    In high-energy heavy-ion collisions at the Large Hadron Collider (LHC), a hot and dense state of matter called the Quark-Gluon Plasma (QGP) is formed. The initial collision geometry and the subsequent expansion during the QGP stage result in the correlations of produced particles, through which the properties of the QGP can be investigated. Two analyses based on the geometrical correlations of produced particles, one in proton-lead (p–Pb) collisions and the other in lead-lead (Pb–Pb) collisions, are presented in this thesis. The data analyzed in this thesis were collected with the ALICE detector at the LHC in p– Pb collisions at a nucleon–nucleon center-of-mass energy of 5.02 TeV, and Pb–Pb collisions at a nucleon–nucleon center-of-mass energy of 2.76 TeV. In the forward-central two-particle correlation analysis in p–Pb collisions, two-particle an- gular correlations between trigger particles in the forward pseudorapidity range (2.5 < |η| < 4.0) and associated particles in the central ran...

  17. Leading Baryon Production at HERA

    International Nuclear Information System (INIS)

    Dodonov, V.; Schmitt, S.

    2009-01-01

    The production of highly energetic forward neutrons has been studied in deep-inelastic scattering. The data were taken with the H1 detector at HERA in the years 2006-2007 and correspond to an integrated luminosity of 117 pb -1 . Semi-inclusive cross sections have been measured in the kinematic region 4 2 2 , 0.7*10 -4 -1 and the fractional momentum of the neutron 0.3 L T and compared to the predictions of models of leading neutron production. Differential cross sections for dijet photoproduction and in association with a leading neutron have been measured in the reaction e + p → e + jet jet X n with the ZEUS detector at HERA using an integrated luminosity of 40pb -1 . The data are consistent with a simple pion exchange model. The ratio of the neutron-tagged and dijet cross sections show violations of factorization of the lepton and photon vertices which can be explained by kinematic effects constraining the phase space for neutron production. Normalised double-differential leading-neutron cross sections have been measured in dijet photoproduction for the first time. The distributions can be fully characterised by only two energy dependent parameters extracted from fits to the data. Absorption effects were studied by comparing the dijet photoproduction measurements and similar results in deep inelastic scattering. No clear effect, not related to kinematics, was observed. In a resolved-enriched dijet photoproduction sample, significantly fewer neutrons were seen than for direct. This depletion can also be accounted for by kinematic constraints. The semi-inclusive reaction e + p → e + X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb -1 . The final state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, x L > 0.32, and its transverse momentum squared satisfied p T 2 2 ; the exchanged photon virtuality, Q 2 , was greater than 3 GeV 2 and the range of

  18. The art of leading meetings.

    Science.gov (United States)

    English, C B

    1987-05-01

    The ability to skillfully lead meetings can contribute to a manager's effectiveness. There are four types of meetings, each serving different needs and requiring different leadership. A manager must know when to hold meetings, what leadership style is appropriate, how and when to use participative management, and how to facilitate a consensus. Considerable planning must be done before a meeting is held. Various leadership and communication skills are required to effectively open, conduct, and close a meeting. Finally, the leader needs to know how to deal with participants who become problems.

  19. Lead-nickel electrochemical batteries

    CERN Document Server

    Glaize, Christian

    2012-01-01

    The lead-acid accumulator was introduced in the middle of the 19th Century, the diverse variants of nickel accumulators between the beginning and the end of the 20th Century. Although old, these technologies are always very present on numerous markets. Unfortunately they are still not used in optimal conditions, often because of the misunderstanding of the internal electrochemical phenomena.This book will show that batteries are complex systems, made commercially available thanks to considerable amounts of scientific research, empiricism and practical knowledge. However, the design of

  20. Lead reactor strategy economical analysis

    International Nuclear Information System (INIS)

    Ciotti, Marco

    2013-01-01

    Conclusions: • A first attempt to evaluate LFR power plant electricity production cost has been performed; • Electricity price is similar to Gen III + plants; • The estimation accuracy is probably low; • Possible costs reduction could arise from coolant characteristics that may improve safety and simplicity by design; • Accident perception, not acceptable by public opinion, may be changed with low potential energy system (non exploding coolant); • Sustainability improvement could open to a better Public acceptance, depending on us. • Problems may arise in coupling a high capital cost low fuel cost plant in a grid with large amount of intermittent sources with priority dispatch. • Lead fast reactors can compete

  1. Testing for lead in toys at day care centers.

    Science.gov (United States)

    Sanders, Martha; Stolz, Julie; Chacon-Baker, Ashley

    2013-01-01

    Exposure to lead-based paint or material has been found to impact children's cognitive and behavioral development at blood lead levels far below current standards. The purpose of the project was to screen for lead in toy items in daycare centers in order to raise awareness of inside environmental lead exposures and minimize lead-based exposures for children. Occupational therapy students in a service learning class tested for lead in ten daycare or public centers using the XRF Thermo Scientific Niton XL3t, a method accepted by the Consumer Product Safety Commission (CPSC). A total of 460 items were tested over a two-month period for an average of 66 toys per setting. Fifty six (56) items tested > 100 ppm, which represented 12% of the entire sample. Items with high lead levels included selected toys constructed with lead-based paint, lead metals, plastics using lead as a color enhancer, and decorative objects. While the actual number of lead-based products is small, the cumulative exposure or habitual use may pose an unnecessary risk to children. Indoor exposures occurred for all day care centers regardless of socio-economic levels. Recommendations to minimize exposures are provided.

  2. Attaching Copper Wires to Magnetic-Reed-Switch Leads

    Science.gov (United States)

    Kamila, Rudolf

    1987-01-01

    Bonding method reliably joins copper wires to short iron-alloy leads from glass-encased dry magnetic-reed switch without disturbing integrity of glass-to-metal seal. Joint resistant to high temperatures and has low electrical resistance.

  3. Assessment of Copper, Cadmium and Lead in Organical Matrix

    International Nuclear Information System (INIS)

    Gutierrez, Ariel

    2000-08-01

    In this report the electrochemical method of differential pulse anode voltametry redisolution voltametry is used to quantitative assessment of copper, cadmium and lead in solution. The methodology is described in the preparation of samples for measurement

  4. Blood Lead Levels and Risk Factors among Preschool Children in a Lead Polluted Area in Taizhou, China

    Directory of Open Access Journals (Sweden)

    Zhenyan Gao

    2017-01-01

    Full Text Available Objective. To determine the blood lead levels and identify related risk factors among preschool children in a lead polluted area (Taizhou, China and provide theoretical support for prevention of lead pollution. Methods. A stratified-clustered-random sampling method was used to determine the survey sample. Blood lead levels were determined by the tungsten atomizer absorption spectrophotometer. Results. A total of 2,018 subjects (average age of 59 months; 1,087 boys and 931 girls were included. The arithmetic mean, geometric mean, and median blood lead levels of the preschool children were 56.4 μg/L, 48.9 μg/L, and 46 μg/L. A total of 8.8% children had blood lead levels >100 μg/L and 43.9% had blood lead levels >50 μg/L. Mother’s education level, father’s occupation, decorative tableware, exposure to makeup, and the residential floor were all risk factors for elevated blood lead levels (odds ratios of 1.42, 1.21, 1.11, 1.19, and 1.27, resp., while hand washing before eating food was a protective factor (odds ratio of 0.88. Conclusions. The blood lead levels of preschool children in Taizhou were higher than in other areas in China and in developed countries. Therefore, policies ensuring lead-based industries are not placed in close proximity to residential areas are required.

  5. A projective geometry lead fiber scintillator detector

    International Nuclear Information System (INIS)

    Paar, H.; Thomas, D.; Sivertz, M.; Ong, B.; Acosta, D.; Taylor, T.; Shreiner, B.

    1990-01-01

    The Superconducting Super Collider (SSC), presently under construction near Dallas, Texas requires highly sophisticated particle detectors. The energy and particle flux at the SSC are more than an order of magnitude higher than the highest machine located at the Fermi National Accelerator near Chicago. An important element of particle detectors for the SSC is the calorimeter. It measures a particle's energy by sampling its energy deposit in heavy material, such as (depleted) uranium or lead. The sampling medium must be interspersed with heavy absorber material. In the case of scintillating plastic, two methods are under consideration: plates and fibers. In the case of plates, a sandwich of scintillator plates and uranium plates is constructed. In the use of fibers (still in the prototype stage), 1 mm. diameter cylindrical scintillating fibers are inserted into grooves that are machined into lead layers. The layers are stacked and epoxied together to form the required geometrical shape of the detector. Lead and scintillating plastic sampling can meet the physics requirements of the detector. This has been shown in an R ampersand D program which is underway at the University of California at San Diego (UCSD), High Energy Physics Group. This R ampersand D is funded by the Department of Energy, High Energy Physics and SSC Divisions

  6. Analysis of neighborhood behavior in lead optimization and array design.

    Science.gov (United States)

    Papadatos, George; Cooper, Anthony W J; Kadirkamanathan, Visakan; Macdonald, Simon J F; McLay, Iain M; Pickett, Stephen D; Pritchard, John M; Willett, Peter; Gillet, Valerie J

    2009-02-01

    Neighborhood behavior describes the extent to which small structural changes defined by a molecular descriptor are likely to lead to small property changes. This study evaluates two methods for the quantification of neighborhood behavior: the optimal diagonal method of Patterson et al. and the optimality criterion method of Horvath and Jeandenans. The methods are evaluated using twelve different types of fingerprint (both 2D and 3D) with screening data derived from several lead optimization projects at GlaxoSmithKline. The principal focus of the work is the design of chemical arrays during lead optimization, and the study hence considers not only biological activity but also important drug properties such as metabolic stability, permeability, and lipophilicity. Evidence is provided to suggest that the optimality criterion method may provide a better quantitative description of neighborhood behavior than the optimal diagonal method.

  7. String formation beyond leading colour

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Jesper R. [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14, Lund (Sweden); Theoretical Physics, CERN,CH-1211, Geneva 23 (Switzerland); Skands, Peter Z. [Theoretical Physics, CERN,CH-1211, Geneva 23 (Switzerland); School of Physics and Astronomy, Monash University,VIC-3800 (Australia)

    2015-08-03

    We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading N{sub C} are allowed to influence the formation of confining potentials (strings). The multiplet structure of SU(3) is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for “baryonic” configurations (e.g., two colours can combine coherently to form an anticolour). In e{sup +}e{sup −}collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in pp collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive 1/N{sub C}{sup 2} suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important 〈p{sub ⊥}〉(n{sub charged}) distribution but also with measured rates (and ratios) of kaons and hyperons, in both ee and pp collisions. Nonetheless, the shape of their p{sub ⊥} spectra remains challenging to explain.

  8. Lead -- supply/demand outlook

    International Nuclear Information System (INIS)

    Schnull, T.

    1999-01-01

    As Japan goes--so goes the world. That was the title of a recent lead article in The Economist that soberly discussed the potential of much more severe global economic problems occurring, if rapid and coordinated efforts were not made to stabilize the economic situation in Asia in general, and in Japan in particular. During the first 6 months of last year, commodity markets reacted violently to the spreading economic problems in Asia. More recent currency and financial problems in Russia have exacerbated an already unpleasant situation. One commodity after another--including oil, many of the agricultural commodities, and each of the base metals--have dropped sharply in price. Many are now trading at multiyear lows. Until there is an overall improvement in the outlook for these regions, sentiment will likely continue to be negative, and metals prices will remain under pressure. That being said, lead has maintained its value better than many other commodities during these difficult times, finding support in relatively strong fundamentals. The author takes a closer look at those supply and demand fundamentals, beginning with consumption

  9. All roads lead to Meyrin

    CERN Multimedia

    Communication locale

    2011-01-01

    Tous les chemins mènent à Meyrin - All roads lead to Meyrin From 29 September to 16 October, 2011, come to the Salle Antoine Verchère in Meyrin for Tous les chemins mènent à Meyrin. The celebration will include an exposition as well as a theatrical performance about Meyrin, the first satellite city in Switzerland. With the help of the memories and testimonies from the people of Meyrin, Tous les chemins mènent à Meyrin is putting the collective memories of the commune on display. It is an occasion for everyone, whether you're from near or far, to find out how all the roads lead to Meyrin.  Salle Antoine-Verchère Route de Meyrin 294 – 1217 Meyrin Tram 18 – Stop: Meyrin Village Thursdays / Fridays / Saturdays at 8pm Sundays at 5pm Regular ticket: CHF 15.- Concession ticket (students, chômeurs, AVS, AI): CHF 12.- Children up to 16: CHF 10.- Family ticket: CHF 35.-

  10. Finland's leading natural gas company

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The ownership structure of Finland's leading natural gas company, Gasum, changed fundamentally in 1999, and the company is now no longer a subsidiary of Fortum Corporation. 'Our new strong and broad ownership base will enable us to develop the natural gas business and pipeline network in Finland in response to the requirements of our Finnish customers', says Antero Jaennes, Gasum's Chairman and CEO, who stresses that Gasum is committed to remaining the leading developer of the Finnish natural gas market and the number-one gas supplier. Natural gas usage in Finland in 1999 totalled 3.9 billion m 3 (38.7 TWh), unchanged from 1998. Natural gas accounted for 11% of Finland's total primary energy need, as it did in 1998. The proportion of natural gas used in district heating rose by 2% to 36%, and moved down 2% in power generation to 10%. Industry's use of natural gas fell 1% to 17%. 75% of natural gas was used in combined heat and power (CHP) generation in industry and district heating. In 2000, Gasum expects to sell 4 billion m 3 of natural gas (40 TWh)

  11. Recycling abandoned lead battery sites

    International Nuclear Information System (INIS)

    Montgomery, A.H.

    1993-01-01

    In the past, automobile batteries were recycled principally for their lead content. The waste generated at battery wrecking facilities consisted of spent acid, crushed casings (ebonite and plastic), and where secondary smelting was involved, matte, slag, and carbon from the smelting process. These waste products were generally disposed in an on-site in a landfill or stored in piles. If the facility shut down because further commercial operations were not financially viable, the waste piles remained to be addressed at a later date through remedial action or reclamation programs. There are many of these facilities in the US. Nationally, about 28 sites have been discovered by the US Environmental Protection Agency (EPA) under the Superfund program and are under investigation or administrative orders for remedial action. A major remediation effort is now underway at the Gould Superfund Site in Portland, Oregon, which was operated as a secondary smelting facility between 1949 and 1981. This paper describes the nature of the contamination at the Gould site and the work conducted by Canonie Environmental Services Corp. (Canonie) to develop a process which would treat the waste from battery wrecking operations and produce revenue generating recyclable products while removing the source contamination (lead) from the site. The full-scale commercial plant is now operating and is expected to achieve a throughput rate of between 200 and 250 tons per day in the coming weeks

  12. Lead pollution, disease, and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Bryce-Smith, D; Waldron, H A

    1974-01-01

    Sources and health effects of atmospheric lead pollution are reviewed. Most of the Pb in gasoline is emitted in the exhaust gases as an aerosol containing particles of inorganic Pb. Some organic Pb is present, but the amount is usually less than 10% of the total. The size of these particles (0.18 to 0.90 micron) ensures maximum pulmonary penetration and absorption. The fallout of airborne particles produces very high concentrations of Pb in city dust, both inside and outside houses. Unpolluted soil contains about 15 ppM Pb, but samples of city dust contain 1000 to 6000 ppM. A daily intake of as little as 30 mg of dust containing 3% Pb produces clinical Pb poisoning in a few months. There is clear evidence to support the thesis that current levels in the environment are capable of producing behavioral abnormalities of types associated with educational disorders and delinquency, and also evidence that delinquents tend to have abnormal lead metabolism.

  13. Learning, Leading and Letting go of Control

    DEFF Research Database (Denmark)

    Jensen, Annie Aarup; Kjær-Rasmussen, Lone Krogh; Iversen, Ann-Merete

    Learning, leading and letting go of control – Learner Led Approaches in Education Annie Aarup Jensen, Lone Krogh Kjær-Rasmussen, Ann-Merete Iversen and Anni Stavnskær Pedersen Abstract The aim of the paper is to introduce a new term in teaching in Higher Education: Learner Led Approaches...... in Education: LED. The sources of inspiration are many as are the experiences we draw from. Problem-based project work (PBL) being one, various classical teacher centered methods, and last but not least a variety of methods aiming towards developing creativity, innovational skills and entrepreneurship. LED...... is inspired by collaboration between professors from Aalborg University, Cornwall College and University College of Northern Denmark. Moravec (2008) claims that educational systems still operate in 1.0 or perhaps 2.0 mode while the surrounding cultures and societies operate in 3.0 mode. The amount...

  14. Lead poisoning in small animals

    Energy Technology Data Exchange (ETDEWEB)

    Scott, H M

    1963-08-17

    During the period 1957 to 1959 a considerable number of dogs were seen which were suffering from colic. Colic is not normally a condition commonly encountered in the dog, and the number of cases seen was large in proportion to the number of dogs in the population concerned. A number of other dogs exhibited nervous signs which varied from symptoms of mild anxiety to exaggerated fits. There was a certain amount of overlapping between the 2 groups in that some cases which originally only showed signs of colic later progressed to the stage where they showed nervous symptoms. The following report deals with 28 cases of lead poisoning in dogs and cats which occurred at Broken Hill, Northern Rhodesia. 8 references, 4 tables.

  15. Anti-cancer Lead Molecule

    KAUST Repository

    Sagar, Sunil

    2014-04-17

    Derivatives of plumbagin can be selectively cytotoxic to breast cancer cells. Derivative `A` (Acetyl Plumbagin) has emerged as a lead molecule for testing against estrogen positive breast cancer and has shown low hepatotoxicity as well as overall lower toxicity in nude mice model. The toxicity of derivative `A` was determined to be even lower than vehicle control (ALT and AST markers). The possible mechanism of action identified based on the microarray experiments and pathway mapping shows that derivative `A` could be acting by altering the cholesterol-related mechanisms. The low toxicity profile of derivative `A` highlights its possible role as future anti-cancer drug and/or as an adjuvant drug to reduce the toxicity of highly toxic chemotherapeutic drugs

  16. Anti-cancer Lead Molecule

    KAUST Repository

    Sagar, Sunil; Kaur, Mandeep; Esau, Luke E.

    2014-01-01

    Derivatives of plumbagin can be selectively cytotoxic to breast cancer cells. Derivative `A` (Acetyl Plumbagin) has emerged as a lead molecule for testing against estrogen positive breast cancer and has shown low hepatotoxicity as well as overall lower toxicity in nude mice model. The toxicity of derivative `A` was determined to be even lower than vehicle control (ALT and AST markers). The possible mechanism of action identified based on the microarray experiments and pathway mapping shows that derivative `A` could be acting by altering the cholesterol-related mechanisms. The low toxicity profile of derivative `A` highlights its possible role as future anti-cancer drug and/or as an adjuvant drug to reduce the toxicity of highly toxic chemotherapeutic drugs

  17. Is Your Child Safe from Lead Poisoning?

    Centers for Disease Control (CDC) Podcasts

    In this podcast, Dr. Mary Jean Brown, chief of CDC's Lead Poisoning and Prevention Program, discusses the importance of testing children for lead poisoning, who should be tested, and what parents can do to prevent lead poisoning.

  18. Heavy flavour production in proton-lead and lead-lead collisions with LHCb

    Science.gov (United States)

    Winn, Michael

    2017-11-01

    The LHCb experiment offers the unique opportunity to study heavy-ion interactions in the forward region (2 kinematic domain complementary to the other 3 large experiments at the LHC. The detector has excellent capabilities for reconstructing quarkonia and open charm states, including baryons, down to zero pT. It can separate the prompt and displaced charm components. In pPb collisions, both forward and backward rapidities are covered thanks to the possibility of beam reversal. Results include measurements of the nuclear modification factor and forward-backward ratio for charmonium, open charm and bottomonium states. These quantities are sensitive probes for nuclear effects in heavy flavour production. Perspectives are given with the large accumulated luminosity during the 2016 pPb run at the LHC. In 2015, LHCb participated successfully for the first time in the PbPb data-taking. The status of the forward prompt J/ψ nuclear modification factor measurement in lead-lead collisions is discussed.

  19. The identification of lead ammunition as a source of lead exposure in First Nations: The use of lead isotope ratios

    International Nuclear Information System (INIS)

    Tsuji, Leonard J.S.; Wainman, Bruce C.; Martin, Ian D.; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-01-01

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of 206 Pb/ 204 Pb and 206 Pb/ 207 Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p 206 Pb/ 204 Pb and 206 Pb/ 207 Pb, and a significant negative correlation for 208 Pb/ 206 Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden

  20. Identification of sources of lead exposure in French children by lead isotope analysis: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Lucas Jean-Paul

    2011-08-01

    Full Text Available Abstract Background The amount of lead in the environment has decreased significantly in recent years, and so did exposure. However, there is no known safe exposure level and, therefore, the exposure of children to lead, although low, remains a major public health issue. With the lower levels of exposure, it is becoming more difficult to identify lead sources and new approaches may be required for preventive action. This study assessed the usefulness of lead isotope ratios for identifying sources of lead using data from a nationwide sample of French children aged from six months to six years with blood lead levels ≥25 μg/L. Methods Blood samples were taken from 125 children, representing about 600,000 French children; environmental samples were taken from their homes and personal information was collected. Lead isotope ratios were determined using quadrupole ICP-MS (inductively coupled plasma - mass spectrometry and the isotopic signatures of potential sources of exposure were matched with those of blood in order to identify the most likely sources. Results In addition to the interpretation of lead concentrations, lead isotope ratios were potentially of use for 57% of children aged from six months to six years with blood lead level ≥ 25 μg/L (7% of overall children in France, about 332,000 children, with at least one potential source of lead and sufficiently well discriminated lead isotope ratios. Lead isotope ratios revealed a single suspected source of exposure for 32% of the subjects and were able to eliminate at least one unlikely source of exposure for 30% of the children. Conclusions In France, lead isotope ratios could provide valuable additional information in about a third of routine environmental investigations.

  1. Recyclization reactions leading to benzimidazoles

    International Nuclear Information System (INIS)

    Mamedov, Vakhid A; Murtazina, Anna M

    2011-01-01

    The published data on the recyclization reactions that afford benzimidazoles are generalized and systematized. Both classical and new methods of benzimidazole synthesis are considered. Attention is focused on the publications over the recent 10-15 years; of the earlier publications, only those unknown to the wide circle of chemists are analyzed.

  2. Recyclization reactions leading to benzimidazoles

    Science.gov (United States)

    Mamedov, Vakhid A.; Murtazina, Anna M.

    2011-05-01

    The published data on the recyclization reactions that afford benzimidazoles are generalized and systematized. Both classical and new methods of benzimidazole synthesis are considered. Attention is focused on the publications over the recent 10-15 years; of the earlier publications, only those unknown to the wide circle of chemists are analyzed.

  3. Teratogenic effects of lead acetate on kidney

    International Nuclear Information System (INIS)

    Jabeen, R.; Tahir, M.; Waqas, S.

    2010-01-01

    Background: Lead remains a considerable occupational and public health problem, which is known to cause a number of adverse effects in both men and women. Conflicting reports have appeared on lead induced nephrotoxicity in experimental studies in the past. There is hardly any work on its teratogenic effects on kidney. Present study was therefore designed to investigate the effects of lead acetate on developing kidney. Methods: Twelve mice were used as experimental model and were divided into two groups of six animals each; group A served as control group and B was used as an experimental group. Lead acetate (10 mg/kg) dissolved in 0.02 ml of distilled water was administered as a single daily dose orally to group B whereas weight related amount of distilled water was given to group A for the entire period of experiment. On 18 day of gestation foetuses were dissected free of uterine wall under the dissecting microscope and were sacrificed; kidneys were removed and fixed in 10% formalin, dehydrated in ascending grades of alcohol, cleared in xylene and infiltrated with filtered paraffin. The paraffin blocks were made and five micron thin sections were obtained using a rotary microtome. The sections were stained with Hematoxylin and eosin and, PAS; these were examined under light microscope. Results: Significant decrease in cortical thickness was observed which varied from 578.6 +- 1.4 mu m in group A to 515.6 +- 5 mu m in group B (p<0.001). Diameter of renal corpuscles varied from 57.7 +- 0.07 mu m in group A to 50.5 +- 0.07 mu m in group B (p<0.001). Moderate cortical tubular atrophy showing thickening of endothelial basement membrane in glomeruli, desquamated epithelium with degenerated nuclei in proximal and distal tubules were observed in group B in contrast to group A. Conclusion: The results of the investigation indicated that lead acetate administration to the dams produced deleterious effects on the developing kidney in mice. (author)

  4. Stable lead isotopes and lake sediments. A useful combination for the study of atmospheric lead pollution history

    Energy Technology Data Exchange (ETDEWEB)

    Renberg, I.; Braennvall, M.-L.; Bindler, R. [Department of Ecology and Environmental Science, Umea University, SE-901 87 Umea (Sweden); Emteryd, O. [Department of Forest Ecology, Swedish University of Agricultural Sciences, SE-901 83 Umea (Sweden)

    2002-06-20

    Analysis of stable lead isotopes and lead concentrations in lake-sediment deposits, not least in varved (annually-laminated) sediments, is a useful method to study lead pollution history. This paper presents details from a study of 31 lakes in Sweden. Using a strong acid digestion of sediment samples and ICP-MS analyses, we have found that Swedish lake sediments have a high natural (pre-pollution) 206[Pb]/207[Pb] ratio (mean 1.52{+-}0.18, range 1.28-2.01, n=31 lakes). In contrast, atmospheric lead pollution derived from metal smelting processes, coal burning and from alkyl-lead added to petrol has a lower ratio (<1.2). Consequently, when pollution lead deposition began approximately 3500 years ago, the lead isotope ratio of the sediments started to decline, and in modern sediments it is typically <1.2. Using the isotope and concentration values and a mixing model, the relative contribution of pollution and natural lead in sediment samples can be calculated. The pollution lead records of the Swedish lake sediments show a consistent picture of the atmospheric lead pollution history. Some noticeable features are the Roman peak, the large and permanent Medieval increase, peaks at approximately 1200 and 1530 ad, the rapid increase after World War II, the peak in the 1970s, and the large modern decline.

  5. Do US Ambient Air Lead Levels Have a Significant Impact on Childhood Blood Lead Levels: Results of a National Study

    Directory of Open Access Journals (Sweden)

    LuAnn L. Brink

    2013-01-01

    Full Text Available Introduction. Although lead paint and leaded gasoline have not been used in the US for thirty years, thousands of US children continue to have blood lead levels (BLLs of concern. Methods. We investigated the potential association of modeled air lead levels and BLLs ≥ 10 μg/dL using a large CDC database with BLLs on children aged 0–3 years. Percent of children with BLLs ≥ 10 μg/dL (2000–2007 by county and proportion of pre-50 housing and SES variables were merged with the US EPA's National Air Toxics Assessment (NATA modeled air lead data. Results. The proportion with BLL ≥ 10 μg/dL was 1.24% in the highest air lead counties, and the proportion with BLL ≥ 10 μg/dL was 0.36% in the lowest air lead counties, resulting in a crude prevalence ratio of 3.4. Further analysis using multivariate negative binomial regression revealed that NATA lead was a significant predictor of % BLL ≥ 10 μg/dL after controlling for percent pre-l950 housing, percent rural, and percent black. A geospatial regression revealed that air lead, percent older housing, and poverty were all significant predictors of % BLL ≥ 10 μg/dL. Conclusions. More emphasis should be given to potential sources of ambient air lead near residential areas.

  6. Shorts due to diagnostic leads

    International Nuclear Information System (INIS)

    Ellis, J.F.; Lubell, M.S.; Pillsbury, R.D.; Shen, S.S.; Thome, R.J.; Walstrom, P.L.

    1985-01-01

    The superconducting toroidal field coils that are being tested in the Large Coil Test Facility (LCTF) are heavily instrumented. General Electric coil, a lead wire of an internal sensor became shorted across an estimated three or four turns of the pancake winding. This short occurred during the final stages of the winding fabrication and was not accessible for repair. Resistance, voltage gradient, and transient voltage decay measurements were performed to characterize the short and the magnetic damping of the large steel bobbin and outer structural ring. The 32-gage wire causing the short was estimated to be about 10 cm long, with a resistance of 55 mΩ. As a safety measure, we decided to burn out the shorted wire at room temperature before installing the coil in LCTF. Tests were made to determine the energy needed to vaporize a small wire. Computer calculations indicated that within the voltage limits set for the coil, it was not feasible to burn out the wire by rapidly dumping the coil from a low-current dc charge-up. We accomplished the burnout by applying 800 V at 3.25 A, and 60 Hz for about 1 s. Transient voltage decay measurements made after the burnout and compared with those made before the attempt confirmed that the short had indeed been opened

  7. Leading local politicians visit CERN

    CERN Multimedia

    2001-01-01

    Left to right:  Professor Maiani, Ernest Nycollin, Anne-Marie Comparini, and Jean Pépin surrounded by young PRAC. On the 13th of November leading local politicians : Mme Anne-Marie Comparini, Présidente du Conseil régional de Rhône-Alpes, M. Ernest Nycollin, Président du Conseil général de la Haute-Savoie et M. Jean Pépin, Président du Conseil général de l'Ain took part in a ceremony which featured the insertion of one of the first LHC magnets into its cryostat.  The department of l'Ain financed a large part of the contruction of building SMA 18 which will see intense activity during the assembly of LHC magnets over the next four years. The department of Haute-Savoie helped in the development of the ultrasonic welding machine for the superconducting cables and the conception of integrated circuits that will be used to measure temperature and pressure inside the magnets. T...

  8. Leading a Culture of Fitness

    Science.gov (United States)

    2011-03-24

    professional fighting force. Numerous studies indicate physical fitness improves cognitive function, the ability to handle stress, injury recovery...4 ―What is Fitness?‖ The CrossFit Journal (October 2002) http://www.crossfit.com (accessed 11 February, 2011). An excellent article beyond the...scope of this paper. Although our definition was derived from Crossfit , it is our position that Crossfit is not, and should not be, the only method to

  9. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

    Science.gov (United States)

    Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

    2012-10-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

  10. Results from the Cooler and Lead Tests

    International Nuclear Information System (INIS)

    Green, Michael A.

    2010-01-01

    The report presents the results of testing MICE spectrometer magnet current leads on a test apparatus that combines both the copper leads and the high temperature superconducting (HTS) leads with a single Cryomech PT415 cooler and liquid helium tank. The current is carried through the copper leads from 300 K to the top of the HTS leads. The current is then carried through the HTS leads to a feed-through from the vacuum space to the inside of a liquid helium tank. The experiment allows one to measure the performance of both cooler stages along with the performance of the leads. While the leads were powered we measured the voltage drops through the copper leads, through the HTS leads, through spliced to the feed-through, through the feed-through and through the low-temperature superconducting loop that connects one lead to the other. Measurements were made using the leads that were used in spectrometer magnet 1A and spectrometer magnet 2A. These are the same leads that were used for Superbend and Venus magnets at LBNL. The IL/A for these leads was 5.2 x 10 6 m -1 . The leads turned out to be too long. The same measurements were made using the leads that were installed in magnet 2B. The magnet 2B leads had an IL/A of 3.3 x 10 6 A m -1 . This report discusses the cooler performance and the measured electrical performance of the lead circuit that contains the copper leads and the superconducting leads. All of the HTS leads that were installed in magnet 2B were current tested using this apparatus.

  11. Dietary exposure to lead in the Netherlands

    NARCIS (Netherlands)

    Boon PE; te Biesebeek JD; van Donkersgoed G; VVH; V&Z

    2017-01-01

    Uptake from the soil is the main route by which lead ends up in food. Lead in soil has its origin in both natural and anthropogenic sources. The lead concentration in food has decreased over the last decennia by the use of unleaded petrol and paint, and the replacement of lead water pipes.

  12. Women researchers lead wage hikes

    Science.gov (United States)

    Bell, Peter M.

    Women employed in the research and development fields in universities, government, and industry made substantial increases and lead men in salary gains in 1981, according to a far-reaching survey of 5000 respondents (Industrial Research and Development, April 1982). At the upper end, 20% of women researchers received salary increases of 14% or more, compared to 13% of the men. The raises were high in 1981; more than half the women in research and development had salary gains of over 9%.The employment picture for women in the scientific and technical fields is somewhat complicated by the affirmative efforts of hiring. More women were hired in 1981, and most newly hired women and men begin at the lowest salaries. This factor contributed to the reality that more women than men at the lower salary ranges received zero raises. However, according to the survey, this is not a trend, since the current efforts to add women in research fields are providing more rewards for women per amount of experience than for men: “…women working in R&D have far less experience than their male counterparts.” (IR&D, op cit.). The median years of experience is down in 1981 from previous years. Some 40% of the women surveyed had less than 6 years experience, compared to about 14% of the men. These figures contrast with those of the survey trends of previous years, which indicated a direct relation between salary and experience. It is still true that because larger numbers of men have over 16 years of experience, the highest paid employees in research and development fields are men. It is noted, however, that in the beginning salary scales ($16-27 k/yr) women outnumber men.

  13. Exposure to lead in South African shooting ranges

    International Nuclear Information System (INIS)

    Mathee, Angela; Jager, Pieter de; Naidoo, Shan; Naicker, Nisha

    2017-01-01

    Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

  14. Childhood Lead Exposure from Battery Recycling in Vietnam

    Directory of Open Access Journals (Sweden)

    William E. Daniell

    2015-01-01

    Full Text Available Background. Battery recycling facilities in developing countries can cause community lead exposure. Objective. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. Methods. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 μg/dL were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. Results. All children had high BLLs; 28% had BLL ≥45 μg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. Discussion. In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results.

  15. Exposure to lead in South African shooting ranges

    Energy Technology Data Exchange (ETDEWEB)

    Mathee, Angela [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg (Environmental Health Department, Faculty of Health Sciences), PO Box 524, Auckland Park, Johannesburg 2006 (South Africa); Jager, Pieter de [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); National Health Laboratory Service (Epidemiology and Surveillance Unit, National Institute for Occupational Health), PO Box 4788, Johannesburg 2000 (South Africa); Naidoo, Shan [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); Naicker, Nisha [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand, School of Public Health, PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg, Environmental Health Department, Faculty of Health Sciences, PO Box 524, Auckland Park, Johannesburg 2006 (South Africa)

    2017-02-15

    Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

  16. Determination of Lead in Urine by Atomic Absorption Spectrophotometry1

    Science.gov (United States)

    Selander, Stig; Cramé, Kim

    1968-01-01

    A method for the determination of lead in urine by means of atomic absorption spectrophotometry (AAS) is described. A combination of wet ashing and extraction with ammonium pyrrolidine dithiocarbamate into isobutylmethylketone was used. The sensitivity was about 0·02 μg./ml. for 1% absorption, and the detection limit was about 0·02 μg./ml. with an instrumental setting convenient for routine analyses of urines. Using the scale expansion technique, the detection limit was below 0·01 μg./ml., but it was found easier to determine urinary lead concentrations below 0·05 μg./ml. by concentrating the lead in the organic solvent by increasing the volume of urine or decreasing that of the solvent. The method was applied to fresh urines, stored urines, and to urines, obtained during treatment with chelating agents, of patients with lead poisoning. Urines with added inorganic lead were not used. The results agreed well with those obtained with a colorimetric dithizone extraction method (r = 0·989). The AAS method is somewhat more simple and allows the determination of smaller lead concentrations. PMID:5647975

  17. Lead exposure biomarkers and mini-mental status exam scores in older men

    NARCIS (Netherlands)

    Wright, RO; Tsaih, SW; Schwartz, J; Spiro, A; McDonald, K; Weiss, ST; Hu, H

    2003-01-01

    Background: Lead is neurotoxic; yet, whether cognitive decline in older persons is associated with lead exposure is unknown. We studied whether lead exposure biomarkers are associated with cognitive test scores, as well as the modifying effects of age on the lead-cognition relationship. Methods:

  18. Lead exposure biomarkers and mini-mental status exam scores in older men

    NARCIS (Netherlands)

    Wright, RO; Tsaih, SW; Schwartz, J; Spiro, A; McDonald, K; Weiss, ST; Hu, H

    Background: Lead is neurotoxic; yet, whether cognitive decline in older persons is associated with lead exposure is unknown. We studied whether lead exposure biomarkers are associated with cognitive test scores, as well as the modifying effects of age on the lead-cognition relationship. Methods:

  19. Measurement of lead compound in stack gas

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Y; Hori, M; Tanikawa, N

    1979-01-01

    The concentration and particle-size distribution of lead compounds in the exhaust gas from various stationary sources are examined. The stationary sources concern lead production from battery scraps, lead smelting of cable mold, steel production from iron scraps, plastic combustion furnace, and a heavy oil boiler. A lead concentration of 0.2-100 mg/cu m in exhaust gas is detected. Furthermore, exhaust gas lead compounds are affected by the raw materials used.

  20. Lead Tolerance and Accumulation in White Poplar Cultivated In Vitro

    Directory of Open Access Journals (Sweden)

    Branislav Kovačević

    2013-06-01

    Full Text Available Background and Purpose: This paper analyses the lead tolerance and accumulation in white poplar genotypes in vitro, in order to optimize genotype evaluation and other procedures in their implementation in phytoremediation projects and landscaping in areas endangered by lead accumulation. Material and Methods: The lead tolerance and accumulation of five white poplar genotypes after 35 days in vitro cultivation on media supplemented with lead was examined. The following Pb(NO32 concentrations were used: 0, 10-6, 10-5, 10-4 and 10-3 M. Tolerance analysis (described by tolerance indices was based on morphological parameters, biomass accumulation and the content of photosynthetic pigments, while lead accumulation was described by shoot lead accumulation and shoot lead content. Results and Conclusions: The chosen lead concentrations appeared not to be lethal. Moreover, the obtained results showed that the tested lead concentrations had a positive effect on: number of formed roots, shoot moisture content and shoot height. The best differentiation among the examined genotypes was gained by the tolerance index based on the shoot height on 10-4 M Pb(NO32. The shoot lead accumulation and shoot lead content significantly increased on 10-4 and 10-3 M Pb(NO32 media. Thus, the concentration of 10-4 M Pb(NO32 is recommended for further research. Two examined genotypes of horticultural value (LCM and LBM achieved a significantly higher lead shoot content compared to the wide spread genotype “Villafranca” (almost 200% and 125% higher, respectively.