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Sample records for cristal comparisons lead

  1. CRISTAL-ISE your project

    CERN Document Server

    Rosaria Marraffino

    2014-01-01

    CRISTAL-ISE, a new version of the CRISTAL data tracking software developed at CERN in the late 90s, has recently been launched under an open source license. The potential for applications of this free software outside particle physics covers several areas, including medicine, where CRISTAL-ISE helps to monitor the progress of Alzheimer’s Disease.   CMS lead tungstate crystals produced in Russia. CRISTAL began as a collaboration between CERN, the University of the West of England (UWE) and the Centre National de la Recherche Scientifique (CNRS).“At the time of CMS’s construction, there was a need for software able to track the production of the almost 80,000 lead tungstate crystals for the Electromagnetic Calorimeter,” explains Andrew Branson, member of the CMS collaboration and Technical Coordinator of the CRISTAL-ISE project. “We started to develop the software when we didn’t yet know the detector testing procedures to go through,...

  2. Detector Construction Management and Quality Control Establishing and Using a CRISTAL System

    CERN Document Server

    Le Goff, J.M.; Bazan, A.; Le Flour, T.; Lieunard, S.; Murray, S.; Vialle, J.P.; Baker, N.; Estrella, F.; Kovacs, Z.; McClatchey, R.; Organtini, G.; Bityukov, S.

    1998-01-01

    The CRISTAL (Cooperating Repositories and an Information System for Tracking Assembly Lifecycles) project is delivering a software system to facilitate the management of the engineering data collected at each stage of production of CMS. CRISTAL captures all the physical characteristics of CMS components as each sub-detector is tested and assembled. These data are retained for later use in areas such as detector slow control, calibration and maintenance. CRISTAL must, therefore, support different views onto its data dependent on the role of the user. These data viewpoints are investigated in this paper. In the recent past two CMS Notes have been written about CRISTAL. The first note, CMS 1996/003, detailed the requirements for CRISTAL, its relationship to other CMS software, its objectives and reviewed the technology on which it would be based. CMS 1997/104 explained some important design concepts on which CRISTAL is and showed how CRISTAL integrated the domains of product data man- agement and workflow manage...

  3. Development and experimental qualification of the new safety-criticality CRISTAL package; Developpement et qualification experimentale du nouveau formulaire de surete-criticite Cristal

    Energy Technology Data Exchange (ETDEWEB)

    Mattera, Ch

    1998-11-01

    This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA 93) and the newest accurate codes (APOLLO 2, MORET 4, TRIPOLI 4). The CRISTAL system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route. To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OECD working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author)

  4. Development and experimental testing of the new safety-criticality Cristal package; Developpement et qualification experimentale du nouveau formulaire de surete-criticite Cristal

    Energy Technology Data Exchange (ETDEWEB)

    Mattera, Ch

    1998-11-10

    This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA93) and the newest accurate codes (APOLLO2, MORET4, TRIPOLI4). The cristal system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route.) To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OCDE working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author) 70 refs.

  5. TOVALOP and CRISTAL. 2. ed.

    International Nuclear Information System (INIS)

    1990-01-01

    The Torrey Canyon incident in 1967 provided a major stimulus to the development of four international regimes (two voluntary agreements and two international conventions) through which compensation for pollution damage and clean-up costs is available following the escape or discharge of persistent oil from tankers. The two voluntary agreements were set up as a result of the determination of the tanker and oil industries to take constructive action, both to encourage prompt and effective clean-up and to assure adequate and timely compensation, prior to the widespread ratification and acceptance of the two international conventions. The voluntary agreements are the Tanker Owners Voluntary Agreement concerning Liability for Oil Pollution (TOVALOP) and the Contract Regarding a Supplement to Tanker Liability for Oil Pollution (CRISTAL). It should be emphasised from the outset that whilst both TOVALOP and CRISTAL are described as voluntary agreements, it is only the decision on whether or not to participate that is voluntary, since having become a party there is a contractual obligation to meet all the terms and conditions of the applicable agreement. This booklet provides a brief summary of TOVALOP and CRISTAL and their relation to the corresponding international conventions developed under the auspices of the International Maritime Organization (IMO), viz the International Convention on Civil Liability for Oil Pollution Damage, 1969 (CLC) and the International Convention on the Establishment of an International Fund for Compensation for Oil Pollution Damage, 1971 (Fund Convention). (author)

  6. Obtención de Relaciones Cuantitativas Estructura-Propiedad en Cristales Líquidos Obtención de Relaciones Cuantitativas Estructura-Propiedad en Cristales Líquidos

    Directory of Open Access Journals (Sweden)

    Maria Reyna Hernández

    2012-02-01

    Full Text Available Sixty nine thermotropic liquid crystal molecules were analyzed by different chemometric methods, including Principal Component Analysis (PCA, Genetic algorithms and Quantitative Structure-Property Relationships (QSPR. Mathematical models to predict nematic transition temperatures (TN were derived. This is the first time that Principal Component Analysis was used to predict liquid crystal properties, leading to the derivation of local (specific models for different molecule sets. Results indicate that local models have higher prediction capabilities than global models, which is consistent to our initial assumption. This methodology will be used in the study of liquid crystals used in pharmaceutical applications.Una serie de 69 cristales líquidos termotrópicos se sometió a una colección de Métodos Quimiométricos incluyendo Análisis de Componentes Principales; Algoritmos Genéticos y Relaciones Cuantitativas Estructura Propiedad para la obtención de modelos matemáticos que permitan predecir las Temperaturas de Transición Nemática, (TN. En este trabajo se aplica por primera vez el Análisis de Componentes Principales al estudio de cristales líquidos para la identifi cación de subconjuntos de moléculas para los cuales se obtuvieron modelos locales. Los resultados obtenidos muestran que la capacidad de predicción de los modelos locales es superior a la del modelo global, lo cual resultó consistente con la hipótesis planteada. La metodología utilizada se extenderá al estudio de cristales líquidoscon actividad farmacológica.

  7. Development and experimental qualification of the new safety-criticality CRISTAL package

    International Nuclear Information System (INIS)

    Mattera, Ch.

    1998-11-01

    This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA 93) and the newest accurate codes (APOLLO 2, MORET 4, TRIPOLI 4). The CRISTAL system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route. To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OECD working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author)

  8. Development and experimental testing of the new safety-criticality Cristal package

    International Nuclear Information System (INIS)

    Mattera, Ch.

    1998-01-01

    This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA93) and the newest accurate codes (APOLLO2, MORET4, TRIPOLI4). The cristal system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route.) To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OCDE working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author)

  9. Pantallas de cristal líquido

    OpenAIRE

    CSIC-UZA - Instituto de Ciencia de Materiales de Aragón (ICMA)

    2010-01-01

    Trabajo presentado como material divulgativo a la II Escuela de Materiales: "Aplicaciones de los Cristales Líquidos", en el marco del XI Congreso Nacional de Materiales, organizado por la Sociedad Española de Materiales y el ICMA.

  10. CRISTAL V1: Criticality package for burn up credit calculations

    International Nuclear Information System (INIS)

    Gomit, Jean-Michel; Cousinou, Patrick; Gantenbein, Francoise; Diop, Cheikh; Fernandez de Grado, Guy; Mijuin, Dominique; Grouiller, Jean-Paul; Marc, Andre; Toubon, Herve

    2003-01-01

    The first version of the CRISTAL package, created and validated as part of a joint project between IRSN, COGEMA and CEA, was delivered to users in November 1999. This fruitful cooperation between IRSN, COGEMA and CEA has been pursued until 2003 with the development and the validation of the package CRISTAL V1, whose main objectives are to improve the criticality safety studies including the Burn up Credit effect. (author)

  11. Oscilador para biosensores basado en microbalanza de cristal de cuarzo (QCM

    Directory of Open Access Journals (Sweden)

    Yeison Javier Montagut Ferizzola

    2011-01-01

    Full Text Available El cristal de cuarzo generalmente es usado en aplicaciones como microbalanza, aprovechando la capacidad que presenta éste para variar su frecuencia de resonancia de acuerdo a los cambios de la densidad superficial de masa depositada en la superficie del resonador. De esta manera, un cristal de cuarzo puede ser utilizado como transductor en un sistema de inmunosensor piezoeléctrico, para detectar uniones antígeno - anticuerpo. En este artículo se presenta una interfaz para microbalanzasde cristal de cuarzo, QCM (del inglés Quartz Crystal Microbalance basado en una versión mejorada de oscilador en configuración diferencial equilibrado y su validación como sistema de caracterización para biosensores. El sistema fue probado con éxito en un inmunosensor piezoeléctrico para la detección del plaguicida Carbaryl.

  12. Termómetros de cristal líquido

    OpenAIRE

    CSIC-UZA - Instituto de Ciencia de Materiales de Aragón (ICMA)

    2010-01-01

    Trabajo presentado como material divulgativo a la II Escuela de Materiales: "Aplicaciones de los Cristales Líquidos", en el marco del XI Congreso Nacional de Materiales, organizado por la Sociedad Española de Materiales y el ICMA.

  13. Towards Provenance and Traceability in CRISTAL for HEP

    CERN Document Server

    Shamdasani, Jetendr; McClatchey, Richard

    2014-01-01

    This paper discusses the CRISTAL object lifecycle management system and its use in provenance data management and the traceability of system events. This software was initially used to capture the construction and calibration of the CMS ECAL detector at CERN for later use by physicists in their data analysis. Some further uses of CRISTAL in different projects (CMS, neuGRID and N4U) are presented as examples of its flexible data model. From these examples, applications are drawn for the High Energy Physics domain and some initial ideas for its use in data preservation HEP are outlined in detail in this paper. Currently investigations are underway to gauge the feasibility of using the N4U Analysis Service or a derivative of it to address the requirements of data and analysis logging and provenance capture within the HEP long term data analysis environment.

  14. CRISTAL V2 Package: Principles and validation domain

    International Nuclear Information System (INIS)

    Gomit, Jean-Michel; Cochet, Bertrand; Leclaire, Nicolas; Carmouze, Coralie; Damian, Frederic; Entringer, Arnaud; Gagnier, Emmanuel

    2017-04-01

    The purpose of this document is to provide a comprehensive and global view of the CRISTAL V2 package. In particular, it sets out the principles of the computational approaches available to the user, through four calculation 'routes': - the 'multigroup Monte Carlo' route, - the 'multigroup deterministic' route, - the 'point-wise Monte Carlo' route, - the 'criticality standard calculation' route. (authors)

  15. Efectos no lineales fotoinducidos en cristales líquidos

    Directory of Open Access Journals (Sweden)

    Juan A. Reyes

    2001-01-01

    Full Text Available Se presentan dos ejemplos en los que se aplica un formalismo analítico que permite describir una amplia variedad de fenómenos no lineales que ocurren cuando un campo óptico se propaga en un cristal líquido. Primero se describe la propagación de ondas planas en celdas rectangulares formadas por cristales líquidos nemáticos, tomando en cuenta su acoplamiento con la orientación. Posteriormente se analiza la propagación de un paquete de ondas en la celda. Se muestra que existe un efecto de guía de ondas en la propagación de los campos ópticos y que los modos transversales magnéticos (TM de la radiación electromagnética se pueden propagar como solitones ópticos. En ausencia de absorción, se calculan explícitamente diversas propiedades de los solitones.

  16. El techo de Cristal en México

    Directory of Open Access Journals (Sweden)

    María Elena Camarena Adame

    2018-01-01

    Full Text Available El “techo de cristal” son los obstáculos que impiden que una mujer alcance puestos de alto nivel en las organizaciones. El objetivo de este trabajo es analizar la situación actual de las mujeres en los puestos de alta dirección en el contexto mexicano, con el fin de conocer qué tanto el techo de cristal afecta su desarrollo profesional. Para ello se realizó una investigación documental recolectando información de las empresas que cotizan en la Bolsa Mexicana de Valores ( bmv , así como de publicaciones recientes del sector empresarial en México. El principal hallazgo de este trabajo muestra que en promedio, las mujeres que conforman el consejo de administración en las empresas que cotizan en la bmv, sólo alcanzan el 4.56 %, asimismo, de las 500 mejores empresas para trabajar en México, sólo el 3% se encuentran dirigidas por mujeres, y de las 50 mujeres más poderosas de México, sólo el 14% trabajan como ejecutivas en una empresa. Ello evidencia que a pesar de los avances referentes a la igualdad de género, aún resulta difícil para las mujeres superar el techo de cristal.

  17. El tren de cristal

    Directory of Open Access Journals (Sweden)

    Antonio Orejudo

    2011-12-01

    Full Text Available La historia de la literatura está escrita por los desobedientes, por los escritores que no respetaron las normas de los géneros que cultivaron. Por eso es tan habitual que las grandes obras literarias, las verdaderas innovaciones, sufran en un primer momento la incomprensión del lector. La primera reacción del lector cuando toma entre sus manos una novela adscrita a un género determinado que sin embargo viola los elementos que definen tal género, es de rechazo. Algo de esto sucede con El tren de cristal, la primera novela de José María Pérez Collados, que se ofrece como novela de campus, y que al mismo tiempo se salta las reglas del género en el que aparentemente se inscribe.

  18. The graphical user interface for CRISTAL V1

    International Nuclear Information System (INIS)

    Heulers, L.; Courtois, G.; Fernex, F.; Gomit, J.M.; Letang, E.

    2003-01-01

    This paper deals with the new Graphical User Interface (GUI) of the CRISTAL V1 package devoted to criticality studies including burn up calculations. The aim of this GUI is to offer users a high level of user-friendliness and flexibility in the data description and the results analysis of codes of the package. The three main components of the GUI (CIGAIES, EJM and OPOSSUM) are presented. The different functionalities of the tools are explained through some applications. (author)

  19. The cristal (right superior septal) coronary artery and its relationship to anomalous left coronary origin

    International Nuclear Information System (INIS)

    Partridge, J.B.; Ridley, L.J.

    2011-01-01

    The cristal artery is an occasional finding, being visible in around 3% of coronary angiograms, arising from the proximal right coronary artery (RCA) and passing downwards and forwards through the muscle of the crista superventricularis. It supplies a variable volume of the superior interventricular septum, and can contribute to collateralization of the other septal vessels. When part or all of the left coronary artery (LCA) arises anomalously from the right coronary sinus, its passage to the left may be in the same pathway as a cristal artery, bearing a tell-tale septal vessel arising from its proximal segment. This helps to differentiate it from one that has a higher pathway, running between the great vessels, and which may have a greater correlation with sudden cardiac death.

  20. ESTUDIO DE LOS FACTORES QUE INFLUYEN EN LA FORMA Y PROPIEDADES DE LOS CRISTALES Y PROPUESTAS PARA LOS ESTUDIANTES DE PROFESORADO DE SECUNDARIA EN GEOLOGÍA

    Directory of Open Access Journals (Sweden)

    Carmen Reyero

    2013-01-01

    Full Text Available En el presente artículo se hace un estudio de la influencia del medio en la estructura y propiedades de los cristales y su importancia a nivel industrial. Consta de una revisión bibliográfica de cómo se han conseguido cambiar la estructura de los cristales de cloruro de sodio variando las condiciones de cristalización, obteniendo, de esta forma, cristales que facilitan el manejo industrial de este producto o mejoran su solubilidad. Por último, se añade una propuesta para trabajar con estudiantes de máster de formación de profesorado de secundaria de la especialidad de geología. La valoración de este trabajo por parte de los alumnos del máster durante los tresaños que se ha llevado a cabo ha sido inmejorable, y ellos lo han aplicado con estudiantes de secundaria.

  1. La fábrica de cristal y vidrio de Santa Lucía (Cartagena y el sector del vidrio español (1834-1908

    Directory of Open Access Journals (Sweden)

    Martínez Carrión, J. M.

    2002-06-01

    Full Text Available This article is a contribution to the Spanish glass industry from the knowledge of Fabrica de Cristal y Vidrio de Santa Lucia (Cartagena during the XIXth century. The evolution of this company is accomplished within the context of the Spanish sector underlining some phases: Its impulse during 1840´s and 1850´s, market problems and competition in the last decades of the XIXth century, and its restructuring at the beginning of the XXth century, which ended with an intense process of concentration and internationalization that affected plane glass and hollow glass. Likewise, industrial location factors, regional distribution of the production, and changes occurred in its various branches between 1856 and 1905 are reported. Data reveal the leading role of this factory from Cartagena in the glass industry and, particularly, its specialization in crystal, glassware of best quality, and white cut glass during the Restoration period.

    El trabajo contribuye al conocimiento de la industria del vidrio español durante el siglo XIX a partir de la Fábrica de Cristal y Vidrio de Santa Lucia (Cartagena. La evolución de la empresa es analizada en el contexto del sector español, destacándose varias fases: el impulso que vivió el sector en las décadas de 1840 y 1850, los problemas de mercado y competitividad en las décadas finales del siglo XIX y la reestructuración de comienzos del siglo XX. Esta última acabó con la formación de estructuras de oligopolio que afectaron a las ramas del vidrio plano y del vidrio hueco. Se destacan, asimismo, los factores de localización industrial, la distribución regional de la producción y los cambios acaecidos en sus diferentes ramas entre 1856 y 1905. Los datos aportados revelan el protagonismo de la empresa de Cartagena en el sector vidriero, y en particular su especialización en cristal y vidrio blanco tallado durante el periodo de la Restauración.

  2. Exportación a Nueva España de manufacturas de la Real Fábrica de Cristales de San Ildefonso (1760-1763

    Directory of Open Access Journals (Sweden)

    María Teresa Ruiz Alcón

    1994-01-01

    Full Text Available La Real Fábrica de Cristales de San Ildefonso, cuyos orígenes se remontan al año 1727, fecha en la que Felipe V concedió una licencia a los maestros catalanes Buena Ventura Sit y Carlos Sac para instalar un taller de manufactura de vidrio en el Real Sitio de San Ildefonso, pasó a ser Real Fábrica de Cristales y Espejos en 1745 por iniciativa del monarca, con el ánimo de fomentar la producción nacional y evitar la importación de productos extranjeros. La fábrica dependía directamente de la Corona y administrativamente, de la Secretaría de Estado.

  3. Análisis, Síntesis y Aplicación de Circuitos Ópticos Birrefringentes Tipo FIR de Dos Puertos en Celosía con Cristales Líquidos

    OpenAIRE

    Vargas, Salvador; Rodríguez, Jorge; Quintero, Raymond; Méndez, Luis; Hernández, Miguel

    2016-01-01

    Los cristales líquidos los encontramos en gran variedad de equipos a nuestro alrededor. Sus aplicaciones más comunes son de pantallas demostradoras en los equipos tales como calculadoras, televisores o computadoras. Sin embargo, también tienen otras aplicaciones menos conocidas como sensores de temperatura, como elementos de realimentación distribuida en láseres, materiales dieléctricos con permitividades sintonizables, como componentes de relleno en fibras de cristal fotónico con el punto de...

  4. Germanium enrichment in supergene settings: evidence from the Cristal nonsulfide Zn prospect, Bongará district, northern Peru

    Science.gov (United States)

    Mondillo, Nicola; Arfè, Giuseppe; Herrington, Richard; Boni, Maria; Wilkinson, Clara; Mormone, Angela

    2018-02-01

    Supergene nonsulfide ores form from the weathering of sulfide mineralization. Given the geochemical affinity of Ge to Si4+ and Fe3+, weathering of Ge-bearing sulfides could potentially lead to Ge enrichments in silicate and Fe-oxy-hydroxide minerals, although bulk rock Ge concentrations in supergene nonsulfide deposits are rarely reported. Here, we present the results of an investigation into Ge concentrations and deportment in the Cristal supergene Zn nonsulfide prospect (Bongará, northern Peru), which formed from the weathering of a preexisting Mississippi Valley-type (MVT) sulfide deposit. Material examined in this study originates from drillcore recovered from oxidized Zn-rich bodies 15-20 m thick, containing 5-45 wt% Zn and Ge concentrations 100 ppm. Microanalysis and laser ablation-ICP-MS show that precursor sphalerite is rich in both Fe (mean Fe = 8.19 wt%) and Ge (mean Ge = 142 ppm). Using the mineral geothermometer GGIMFis—geothermometer for Ga, Ge, In, Mn, and Fe in sphalerite—proposed by Frenzel et al. (Ore Geol Rev 76:52-78, 2016), sphalerite trace element data from the Cristal prospect suggest a possible formation temperature ( T GGIMFis) of 225 ± 50 °C, anomalously high for a MVT deposit. Germanium concentrations measured in both goethite (mean values 100 to 229 ppm, max 511 ppm) and hemimorphite (mean values 39 to 137 ppm, max 258 ppm) are similar to concentrations measured in hypogene sphalerite. Additionally, the Ge concentrations recorded in bulk rock analyses of sphalerite-bearing and oxidized samples are also similar. A persistent warm-humid climate is interpreted for the region, resulting in the development of an oxidation zone favoring the formation of abundant Zn hydrosilicates and Fe hydroxides, both able to incorporate Ge in their crystal structure. In this scenario, Ge has been prevented from dispersion during the weathering of the Ge-bearing sulfide bodies and remains in the resultant nonsulfide ore.

  5. Estudio mediante resonancia magnética de efectos pretransicionales en cristales líquidos

    OpenAIRE

    Vaca Chavez, Fabián

    2002-01-01

    Tesis (Doctor en Física)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2002. Se presenta el estudio mediante la técnica de Resonancia Magnética Nuclear de los efectos pretransicionales en diferentes fases de cristales líquidos termotrópicos y liotrópicos. Estos compuestos son materia de innumerables trabajos tanto teóricos como experimentales, debido a que son materiales extremadamente interesantes por sus aplicaciones tecnológicas, ópticas y biológicas. Se...

  6. Identification of Zn-Bearing Micas and Clays from the Cristal and Mina Grande Zinc Deposits (Bongará Province, Amazonas Region, Northern Peru

    Directory of Open Access Journals (Sweden)

    Giuseppe Arfè

    2017-11-01

    Full Text Available Zn-bearing phyllosilicates are common minerals in nonsulfide Zn deposits, but they seldom represent the prevailing economic species. However, even though the presence of Zn-bearing clays is considered as a disadvantage in mineral processing, their characteristics can give crucial information on the genesis of the oxidized mineralization. This research has been carried out on the Mina Grande and Cristal Zn-sulfide/nonsulfide deposits, which occur in the Bongará district (Northern Peru. In both of the deposits, Zn-bearing micas and clays occur as an accessory to the ore minerals. The XRD analyses and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS investigations revealed that the Zn-bearing micas that are occurring in both deposits mostly consist of I/S mixed layers of detrital origin, which have been partly altered or overprinted by sauconite during the supergene alteration of sulfides. Sporadic hendricksite was also identified in the Cristal nonsulfide mineral assemblage, whereas at Mina Grande, the fraipontite-zaccagnaite (3R-polytype association was detected. The identified zaccagnaite polytype suggests that both fraipontite and zaccagnaite are genetically related to weathering processes. The hendricksite detected at Cristal is a product of hydrothermal alteration, which is formed during the emplacement of sulfides. The complex nature of the identified phyllosilicates may be considered as evidence of the multiple processes (hydrothermal and supergene that occurred in the Bongará district.

  7. Dispositivos de cristal líquido dopados con nanopartículas = Nanoparticle-doped liquid crystal devices

    OpenAIRE

    García García, Amanda

    2017-01-01

    Esta Tesis Doctoral se centra en el estudio del dopado de cristal líquido (CL) con nanopartículas conductoras y semiconductoras y en su interacción mutua. El dopado con nanopartículas modifica muchas propiedades de los materiales. Concretamente, los nanotubos de carbono (CNTs) han demostrado ser nanopartículas anisótropas capaces de cambiar propiedades eléctricas y ópticas de los CL dependiendo de la orientación relativa del CNT con la aplicación del campo eléctrico. Los CNTs son nanopartícu...

  8. Aquatic Coleoptera from El Cristal Natural Reserve (Santa Fe Province, Argentina

    Directory of Open Access Journals (Sweden)

    Gabriel A. MACCHIA

    2015-01-01

    Full Text Available Se presenta una lista de los coleópteros acuáticos colectados en la Reserva Natural El Cristal. Se identificaron 77 especies incluidas en 35 géneros y seis familias. Diez géneros se citan por primera vez de la provincia de Santa Fe: Copelatus Erichson, Anodocheilus Babington, Bidessodes Régimbart, Bidessonotus Régimbart, Pachydrus Sharp, Laccomimus Toledo & Michat (Dytiscidae, Mesonoterus Sharp (Noteridae, Pelonomus Erichson (Dryopidae, Chaetarthria Stephens y Paracymus Thomson (Hydrophilidae. Además, 17 especies se registran por primera vez de la provincia de Santa Fe: Thermonectus succinctus (Aubé, Anodocheilus maculatus Babington, Bidessonotus obtusatus Régimbart, Pachydrus globosus (Aubé, P. obesus Sharp (Dytiscidae, Hydrocanthus paraguayensis Zimmermann, Mesonoterus laevicollis Sharp, Suphis freudei Mouchamps, Suphisellus curtus (Sharp, S. grammicus (Sharp, S. nigrinus (Aubé, S. remator (Sharp (Noteridae, Chaetarthria bruchi Balfour-Browne, Enochrus sublongus (Fall, Berosus paraguayanus Knisch, Derallus altus (Leconte y Phaenonotum regimbarti Bruch (Hydrophilidae.

  9. Urna de cristal como canal digital de participación ciudadana en Colombia

    Directory of Open Access Journals (Sweden)

    John Edickson Amaya-Rodríguez

    2017-01-01

    Full Text Available En este artículo se describen se describe la normativa vigente en Colombia referente al gobierno electrónico. Asimismo, se hace referencia las diferentes herramientas utilizadas por la estrategia urna de cristal del gobierno colombiano. Asimismo, se evalúa su alcance en la ciudadanía tanto con los informes publicados por esta estrategia, así como a través de una encuesta realizada en la totalidad de los departamentos del país. Finalmente se proponen unas recomendaciones que pueden ser consideradas en el desarrollo de las actividades del canal seleccionado con el objetivo que se pueda ampliar la cobertura de dicho canal y se pueda tener un efectivo acercamiento de los ciudadanos al gobierno a través de herramientas tecnológicas.

  10. Caracterización de cristales de calcita bioprecipitada por un aislamiento nativo de Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Carolina Montoya

    2007-02-01

    Full Text Available Bacillus subtilis es una bacteria útil en algunas aplicaciones biotecnológicas por poseer enzimas como las amilasas, las cuales desempeñan un papel importante en diferentes procesos industriales. Una de sus propiedades, poco estudiada, ha sido su capacidad de inducir bioprecipitación química de carbonato de calcio (Ca2+ + HCO3 3> CaCO3 + H+ mediante un mecanismo similar al observado en la formación de rocas, suelos y estructuras biológicas como huesos, conchas y dientes. En esta investigación se estudiaron los cristales producidos por un aislamiento nativo de B. subtilis, tomado de una mina de oro situada en Segovia (Antioquia. Se determinó su capacidad calcificante utilizando el medio de cultivo B4. La caracterización del cristal producido se realizó con lupa binocular, microscopio petrográfico de luz plana polarizada (MOLP en su modo de luz transmitida, microscopio electrónico de barrido con analizador de estado sólido (ESEM/EDX y espectroscopía infrarroja con transformada de Fourier (FTIR. A partir de los resultados obtenidos por medio de la caracterización utilizando la combinación de las técnicas analíticas que se mencionaron, fue posible determinar que el aislado nativo de B. subtilis generó y por ende es productor de cristales de carbonato de calcio (CaCO3 en su forma polimórfica de baja temperatura (calcite.Palabras clave: Bacillus subtilis, calcita, bioprecipitación, mineralogía aplicada, biomineralogía.ABSTRACTBacillus subtilis, a bacterium useful in some biotechnology applications, contains enzymes such as amylases, which play an important role in several industrial processes. One of its properties, not very well studied, is its capacity to induce the chemical bioprecipitation of CaCO3 (Ca2+ + HCO3 —> CaCO3 + H+, a similar mechanism commonly observed in the formation of rocks, soils and biological structures like bones, shells and teeth. In this work we have studied carbonate crystals produced by a B

  11. Caracterización de cristales de calcita bioprecipitada por un aislamiento nativo de Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Carolina Montoya

    2005-07-01

    Full Text Available Bacillus subtilis es una bacteria útil en algunas aplicaciones biotecnológicas por poseer enzimas como las amilasas, las cuales desempeñan un papel importante en diferentes procesos industriales. Una de sus propiedades, poco estudiada, ha sido su capacidad de inducir bioprecipitación química de carbonato de calcio (Ca2+ + HCO3 3> CaCO3 + H+ mediante un mecanismo similar al observado en la formación de rocas, suelos y estructuras biológicas como huesos, conchas y dientes. En esta investigación se estudiaron los cristales producidos por un aislamiento nativo de B. subtilis, tomado de una mina de oro situada en Segovia (Antioquia. Se determinó su capacidad calcificante utilizando el medio de cultivo B4. La caracterización del cristal producido se realizó con lupa binocular, microscopio petrográfico de luz plana polarizada (MOLP en su modo de luz transmitida, microscopio electrónico de barrido con analizador de estado sólido (ESEM/EDX y espectroscopía infrarroja con transformada de Fourier (FTIR. A partir de los resultados obtenidos por medio de la caracterización utilizando la combinación de las técnicas analíticas que se mencionaron, fue posible determinar que el aislado nativo de B. subtilis generó y por ende es productor de cristales de carbonato de calcio (CaCO3 en su forma polimórfica de baja temperatura (calcite.Palabras clave: Bacillus subtilis, calcita, bioprecipitación, mineralogía aplicada, biomineralogía.ABSTRACTBacillus subtilis, a bacterium useful in some biotechnology applications, contains enzymes such as amylases, which play an important role in several industrial processes. One of its properties, not very well studied, is its capacity to induce the chemical bioprecipitation of CaCO3 (Ca2+ + HCO3 —> CaCO3 + H+, a similar mechanism commonly observed in the formation of rocks, soils and biological structures like bones, shells and teeth. In this work we have studied carbonate crystals produced by a B

  12. Software data acquisition system for the ''Chateau de Cristal'' multicounter 74 BaF2

    International Nuclear Information System (INIS)

    Adzama, G.

    1985-01-01

    The ''Chateau de Cristal'' is a 74 BaF2 detector assembly. Other detectors such as Ge (up to 12) and particle detectors can be added to this multidetector. The data acquisition system hardware and software are implemented in 3 VME crates. The operating system is handled by 68000 Motorola microprocessors. This work is dedicated to the initialization and control tasks of the multidetector. Handling of high voltage power supply for the 74 BaF2 detectors via a RS 232 C serial port, CAMAC initialization for the ADC 4300 Lecroy and DFC modules, data exchange between the 3 VME crates and automatic energy calibration for the BaF2 detectors. All the software is written in 68000 Motorola assembly language [fr

  13. Electrohidrodinámica de cristales líquidos nemáticos

    Directory of Open Access Journals (Sweden)

    Rosalío F. Rodríguez

    2001-01-01

    Full Text Available Se presenta un formalismo analítico que permite describir una amplia variedad de fenómenos ópticos no lineales que ocurren cuando una onda electromagnética se propaga en un cristal líquido. A partir de propiedades termodinámicas y de simetría, primero se construye un conjunto cerrado de ecuaciones hidrodinámicas que proporcionan una descripción completa de la dinámica de un nemático de bajo peso molecular en ausencia de campos externos. Posteriormente, se incluye la presencia de un campo electromagnético externo que se propaga en el fluido. Se discute el carácter no lineal y acoplado de las ecuaciones y, para resolverlas, se propone un método iterativo de aproximaciones sistemáticas en términos de potencias de parámetros con una interpretación física precisa. Se concluye discutiendo las ventajas y limitaciones del punto de vista adoptado en este trabajo..

  14. Comparison of psychosexual problems between substance dependence patients

    Directory of Open Access Journals (Sweden)

    Hamid Kazami

    2014-06-01

    Full Text Available Background and aims: Sexual dissatisfaction is one of the common problems in patients of Substance dependency. The aim of this study was to investigate psychosexual problems in marital relationships in substance dependence patients: Crack, Cristal and Opium and compare with control group. Methods: In this descriptive-analytic study, 56 substance dependences referred to addiction treatment center were selected by convenience sampling and assigned to four groups: 20 Opium consumers, 18 on Crack, 18 on Cristal and 20 patients in control group. The Multidimensional Sexuality Questionnaires (MSQ were completed by participants. Results: Based on subscales of Multidimensional Sexuality Questionnaire, a significant difference was observed in score mean among three groups and between experimental groups and control group in sexual subscales: preoccupation, motivation, assertiveness, depression, monitoring power of other sex, sexual control, external supervision, fear of sexual relationship and satisfaction (P>0.05. Differences between (Cristal and Crack and (Opium and Cristal in sexual subscales: preoccupation, motivation, fear, depression, power-other sexual control, supervision, and fear of sexual relationship and satisfaction were significant (P>0.05. Score mean indicated that the Cristal abusers in all of subscales have higher scores mean than Crack, and Opium. Conclusion: According to the results of current study, the available addicting substance in the market affects the consumer's sexual practices, and will be caused deleterious effects on family and marital sexual health.

  15. Precise adjustment of the orientation of a crystal mounted on a goniometric head; Reglage precis de l'orientation d'un cristal monte sur une tete goniometrique

    Energy Technology Data Exchange (ETDEWEB)

    Tournarie, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Curien, H [Laboratoire de Mineralogie-Cristallographie, Sorbonne, 75 - Paris (France)

    1959-07-01

    Trigonometric calculus required to give the orientation of a crystal with a good accuracy, is presented in order to show the use of an E 101 computer. (author) [French] Les calculs trigonometriques necessaires pour orienter d'une maniere precise un cristal sont presentes en vue de leur execution sur une machine E 101. (auteur)

  16. Comparison of the radiological and chemical toxicity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose.

  17. Comparison of the radiological and chemical toxicity of lead

    International Nuclear Information System (INIS)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose

  18. I cristalli sonici come barriere antirumore - Sonic crystals as tunable noise barriers

    Directory of Open Access Journals (Sweden)

    Federica Morandi

    2017-02-01

    Full Text Available Il presente contributo riporta un'introduzione al tema della propagazione del suono nei cristalli sonici e un excursus sulla letteratura scientifica più recente. Si discutono i risultati di alcune indagini sperimentali condotte presso l’Università di Bologna inerenti misure di Insertion Loss, misure effettuate all’interno del reticolo e misure di intensimetria. Infine i valori di Sound Insulation misurati per un cristallo sonico sono confrontati con valori misurati su barriere tradizionali, evidenziando come il cristallo sonico permetta di raggiungere un isolamento confrontabile con il valore soglia di Insertion Loss raggiungibile a causa della diffrazione del bordo superiore della barriera. ------ This work reports an introduction to the topic of wave propagation in sonic crystals and a review of the recent scientific literature. The paper presents the results of some experimental investigations carried out at the University of Bologna by discussing Insertion Loss measurements, measurements performed inside the lattice and sound intensity measurements. Finally, the Sound Insulation Index measured for a sonic crystal is compared to the values measured for common noise barriers, pointing out that sonic crystals reach insulation values comparable to the maximum Insertion Loss achievable due to the top edge diffraction.

  19. Hydrogen generation comparison between lead-calcium and lead-antimony batteries in nuclear power plant

    International Nuclear Information System (INIS)

    Zhao Hongjun; Qi Suoni; Shen Yan; Li Jia

    2014-01-01

    Battery type selection is performed with the help of technical information supplied by vendors, and according to relevant criteria. Analysis and comparison of the hydrogen generation differences between two different lead-acid battery types are carried out through calculation. The analysis result may provide suggestions for battery type selection in nuclear power plant. (authors)

  20. Naturaleza fractal en redes de cristales de grasas

    Directory of Open Access Journals (Sweden)

    Gómez Herrera, C.

    2004-06-01

    Full Text Available The determination of the mechanical and rheological characteris­tics of several plastic fats requires a detailed understanding of the microstructure of the fat crystal network aggregates. The (or A fractal approach is useful for the characterization of this micros­tructure. This review begins with information on fractality and statistical self-similar structure. Estimations for fractal dimension by means of equations relating the volume fraction of solid fat to shear elastic modulus G' in linear region are described. The influence of interesterification on fractal dimension decrease (from 2, 46 to 2 ,15 for butterfat-canola oil blends is notable . This influence is not significant for fat blends without butterfat. The need for an increase in research concerning the relationship between fractality and rheology in plastic fats is emphasized.La determinación de las características mecánicas y reológicas de ciertas grasas plásticas requiere conocimientos detallados sobre las microestructuras de los agregados que forman la red de cristales grasos. El estudio de la naturaleza fractal de estas microestructuras resulta útil para su carac­terización. Este artículo de información se inicia con descripciones de la dimensión fractal y de la "autosimilitud estadística". A continuación se describe el cálculo de la dimensión fractal mediante ecuaciones que relacionan la fracción en volumen de grasa sólida con el módulo de recuperación (G' dentro de un comportamiento viscoelástico lineal. Se destaca la influencia que la interesterificación ejerce sobre la dimensión fractal de una mezcla de grasa láctea y aceite de canola (que pasa de 2,64 a 2,15. Esta influencia no se presenta en mezclas sin grasa láctea. Se insiste sobre la necesidad de incrementar las investi­gaciones sobre la relación entre reología y estructura fractal en grasas plásticas.

  1. Combinación de pantallas de cristal líquido para la modulación compleja de frentes de onda. Aplicación en reconstrucción de hologramas de Fresnel digitales.

    OpenAIRE

    Tudela Fernández, Raúl; Martín Badosa, Estela; Labastida i Juan, Ignasi, 1970-; Vallmitjana i Rico, Santiago; Carnicer González, Arturo

    2012-01-01

    En este trabajo se presentan distintas alternativas para obtener la modulación compleja completa de frentes de onda mediante la suma de la modulación introducida por dos pantallas de cristal líquido. Para los distintos métodos se presentan resultados simulados de reconstrucciones de hologramas de Fresnel digitales.

  2. Edificio para Cristalería Española

    Directory of Open Access Journals (Sweden)

    de la Joya, R.

    1964-03-01

    Full Text Available In the course of a series of lectures on the subject of curtain walls, held at the Higher Technical College of Architecture, in Madrid, the author described his own experience whilst constructing a building (designed by him and by Mr. Manuel Barbero for the firm Cristalería Española, at San Andrés del Palomar, Barcelona. Mr. De la Joya summarised the advantages that foreign experts attribute to curtain walls. These advantages are: less weight of the materials of the enclosing walls; maximum use of the available building surface; cheaper foundations; better building time control; superior quality and accuracy; and greater maintenance facility. The lecturer then explained why, and in what aspects, he was in disagreement with the above supposed advantages. He dealt with these as follows: 1. In terms of present day construction, with concrete blocks and lightweight flooring structures, it is not easy to save much weight, owing to the number of special fittings that are necessary to support and keep the curtain wall in place.—2. Although in theory a. curtain wall may be only 4 or 5 cm thick, the truth is that unless heating or air conditioning is provided on a much larger scale, a special internal protection layer is necessary.—3. It is difficult to reduce the cost of the foundations by fitting curtain walls, and any calculated saving in cost in this aspect is more theoretical than real.—4. Building time estimates usually fail to work out in practice, and in addition to this, workmanship quality is not yet very satisfactory.—5. Curtain walls require periodic overhauls, so that they do not age too rapidly, and in this sense they are no better than traditional walls. The lecturer also made a number of additional points, one of them being that he did not advise the use of curtain walls in Spain (because of the cheapness of brickwalls, the climate, the high cost of air conditioning, etc. He also emphasized how important it is to make a very

  3. Contributions to the qualification of the ''CRISTAL'' criticality calculi scheme: interpretation of critical experiments. Elaboration of a characterization system of neutronic configurations; Contributions a la qualification du schema de calcul de criticite ''cristal'': interpretation d'experiences critiques. Elaboration d'un systeme de caracterisation des configurations neutroniques

    Energy Technology Data Exchange (ETDEWEB)

    Gagnier, E

    1999-06-01

    This thesis work is about the validation of the new criticality-safety package CRISTAL and contributes to the modernization and the improvement of the computational tools. The first part presents neutronic elements, the objectives of safety criticality studies and the package CRISTAL. Then, the validation work concerned two series of experiments involving uranyl solutions (UO{sub 2}F{sub 2}) and UO{sub 2} powders. For these experiments, the differences between the computation results and the experimental results were analysed. It was highlighted interesting physical phenomena such of the compensations of errors between the approximate representation by the 99 energy group structure on the first resonance of oxygen and the anisotropy of the diffusion simulation as well as the influence of uranium 234 in high enriched solutions in uranium 235. Once the work of the experimental qualification carried out, raises the question of the use the base of qualification and the ''calculation-experiment'' variations which are referred to it. It is often difficult to establish the link between the ''studied configuration'' and the experiments of the base of qualification. The presented characterisation system proposes to answer in a way automatic and quantified this difficulty: - in bringing an answer on the package qualification for the studied configuration, - in giving an estimate of the package bias. To answer these points, it was defined a set of 35 characteristic neutronic parameters representing the behaviour of the medium. To process the information brought by these parameters and to use it to answer the objectives of the system, we called upon statistical methods (Principal Components Analysis and Sliced Inverse Regression). The results obtained in the feasibility studies showed the relevance of these methods for the considered objectives. (author)

  4. Contributions to the qualification of the ''CRISTAL'' criticality calculi scheme: interpretation of critical experiments. Elaboration of a characterization system of neutronic configurations

    International Nuclear Information System (INIS)

    Gagnier, E.

    1999-06-01

    This thesis work is about the validation of the new criticality-safety package CRISTAL and contributes to the modernization and the improvement of the computational tools. The first part presents neutronic elements, the objectives of safety criticality studies and the package CRISTAL. Then, the validation work concerned two series of experiments involving uranyl solutions (UO 2 F 2 ) and UO 2 powders. For these experiments, the differences between the computation results and the experimental results were analysed. It was highlighted interesting physical phenomena such of the compensations of errors between the approximate representation by the 99 energy group structure on the first resonance of oxygen and the anisotropy of the diffusion simulation as well as the influence of uranium 234 in high enriched solutions in uranium 235. Once the work of the experimental qualification carried out, raises the question of the use the base of qualification and the ''calculation-experiment'' variations which are referred to it. It is often difficult to establish the link between the ''studied configuration'' and the experiments of the base of qualification. The presented characterisation system proposes to answer in a way automatic and quantified this difficulty: - in bringing an answer on the package qualification for the studied configuration, - in giving an estimate of the package bias. To answer these points, it was defined a set of 35 characteristic neutronic parameters representing the behaviour of the medium. To process the information brought by these parameters and to use it to answer the objectives of the system, we called upon statistical methods (Principal Components Analysis and Sliced Inverse Regression). The results obtained in the feasibility studies showed the relevance of these methods for the considered objectives. (author)

  5. Determination of lead in whole blood: Comparison of the LeadCare blood lead testing system with zeeman longitudinal electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Pineau, A.; Viallefont, A.; Fauconneau, B.; Rafael, M.; Guillard, O.

    2002-01-01

    This study compares the efficiency of blood lead level analysis by graphite furnace atomic absorption spectrometry (GFAAS) and the portable LeadCare Blood lead testing system (LCS). Recoveries of two added lead concentrations of 22 and 42 μg/dL ranged from 102.4 to 105.5% for LCS and from 96.3 to 97.2% for GFAAS. Measurement of a certified sample (Certified Danish Whole Blood) at a blood lead concentration of 26.2 μg/dL gave within- and between-run coefficients of variation which were both approximately 8% by LCS and 2% by GFAAS. Comparison of the tested method (LCS) versus GFAAS from analysis of 76 samples of blood lead collected from workers in different industrial sectors showed imperfect overall correlation (r = 0.95). The LCS is quite suitable for screening purposes, but requires the use of non-frozen blood collected less than 24 h before. Conservative threshold values should be applied when using the LCS for initial screening in the field. (orig.)

  6. Contributions to the qualification of the ''CRISTAL'' criticality calculi scheme: interpretation of critical experiments. Elaboration of a characterization system of neutronic configurations; Contributions a la qualification du schema de calcul de criticite ''cristal'': interpretation d'experiences critiques. Elaboration d'un systeme de caracterisation des configurations neutroniques

    Energy Technology Data Exchange (ETDEWEB)

    Gagnier, E

    1999-06-01

    This thesis work is about the validation of the new criticality-safety package CRISTAL and contributes to the modernization and the improvement of the computational tools. The first part presents neutronic elements, the objectives of safety criticality studies and the package CRISTAL. Then, the validation work concerned two series of experiments involving uranyl solutions (UO{sub 2}F{sub 2}) and UO{sub 2} powders. For these experiments, the differences between the computation results and the experimental results were analysed. It was highlighted interesting physical phenomena such of the compensations of errors between the approximate representation by the 99 energy group structure on the first resonance of oxygen and the anisotropy of the diffusion simulation as well as the influence of uranium 234 in high enriched solutions in uranium 235. Once the work of the experimental qualification carried out, raises the question of the use the base of qualification and the ''calculation-experiment'' variations which are referred to it. It is often difficult to establish the link between the ''studied configuration'' and the experiments of the base of qualification. The presented characterisation system proposes to answer in a way automatic and quantified this difficulty: - in bringing an answer on the package qualification for the studied configuration, - in giving an estimate of the package bias. To answer these points, it was defined a set of 35 characteristic neutronic parameters representing the behaviour of the medium. To process the information brought by these parameters and to use it to answer the objectives of the system, we called upon statistical methods (Principal Components Analysis and Sliced Inverse Regression). The results obtained in the feasibility studies showed the relevance of these methods for the considered objectives. (author)

  7. The performance of a soluble lead-acid flow battery and its comparison to a static lead-acid battery

    International Nuclear Information System (INIS)

    Zhang, C.P.; Sharkh, S.M.; Li, X.; Walsh, F.C.; Zhang, C.N.; Jiang, J.C.

    2011-01-01

    Highlights: → We compared the electrochemical characteristics of two types of the batteries. → SLAFB shows as good performance as SLAB under the same current density. → The cycle life of two batteries is strongly influenced by the depth of discharge. → The cycle life of SLAFB can be extended by treatment with hydrogen peroxide. - Abstract: The electrochemistry of static lead-acid and soluble lead-acid flow batteries is summarised and the differences between the two batteries are highlighted. A general comparison of the performance of an unoptimised soluble lead-acid flow laboratory cell and a commercial lead-acid battery during charge and discharge is reported. The influence of the depth of discharge on cycle life for both batteries is also considered. The flow battery was found to have a better charge efficiency than the static one, but the cells were found to have comparable energy efficiencies. The self-discharge characteristics of the soluble lead-acid battery were also measured and compared to reported values for a commercial static battery. Some self-discharge of the soluble lead-acid flow battery is observed during prolonged periods on open-circuit but the battery could recover its normal performance after a single charge-discharge cycle.

  8. Amplificación del Segundo Armónico Mediante el Uso de un Cristal Fotónico Amplificación del Segundo Armónico Mediante el Uso de un Cristal Fotónico

    Directory of Open Access Journals (Sweden)

    G. Cerda-Villicaña

    2012-02-01

    Full Text Available Presentamos evidencia experimental de la generación y amplificación de un haz de segundo armónico en una guía de onda plana de niobato de litio mediante la inscripción de un cristal fotónico unidimensional en dicha guía de onda. La observación fue realizada utilizando un láser de Neodimio-YAG (Nd:YAG en modo continuo (cw así como en amarre de modos, obteniendo pulsos con una potencia promedio por debajo del orden de nanojoules (10-9 J y con duración de 150 picosegundos (10-12 seg. La dispersión geométrica introducida por la estructura de bandas fotónica (PGB para los modos de la guía de onda a la frecuencia fundamental y doblada mejora las condiciones de empalme de fase y por lo tanto aumenta la eficiencia de conversión. We present experimental evidence of enhanced second harmonic generation in planar lithiumniobate waveguides by using a photonic crystal on the waveguide. The enhanced signal was observed by using a Nd: YAG pump laser in both continuous mode (c. w. and mode-locked. This last produced sub-nanojoules (10-9 J average power pulses with 150 picoseconds (10-12 s time duration. Phase matching conditions and the conversion efficiency process were improved because of the geometrical dispersion introduced in waveguide modes inside of the photonic band gap structure (PBG at fundamental and second harmonic frequencies.

  9. Determination of lead in red wine for CCQM-K30 international comparison by using ID-ICPMS

    International Nuclear Information System (INIS)

    Zhou Tao; Wang Jun; Lu Hai; Zhao Motian

    2007-01-01

    The content of lead in red wine for CCQM-K30 international key comparison is determined by using isotope dilution mass spectrometry (IDMS). This test almost reach detect limit of the method because the content of lead in red wine was only 3 ng/g and the procedure blank was about 0.3 ng. The comparison results indicate that it is easy to achieve agreements using IDMS. In uncertainty analysis, all of the factors about IDMS method were considered. But, procedure blank took great inference to experiment precision and enlarged the total uncertainty. Therefore the controls of procedure blank were very important for the analysis of ultra-trace concentration of samples. (authors)

  10. Cardioplegia cristalóide, barotrauma e função endotelial: considerações experimentais Crystalloid cardioplegia, barotrauma and endothelium function: experimental considerations

    Directory of Open Access Journals (Sweden)

    Paulo Roberto B Évora

    1996-06-01

    Full Text Available O presente ensaio experimental estudou o efeito da infusão de solução cardioplégica cristalóide a altas pressões sobre a função endotelial de artérias epicárdicas de cães. Não se encontraram alterações a nível de receptores (curvas dose-respostas à ACH e ADP; da transdução do sinal iniciado nos receptores/sitema de G-proteínas (fluoreto de sódio e nos processos intracelulares da produção de EDRF/ NO (fosfolipase C e ionóforo do cálcio A23187. A função da musculatura lisa vascular não foi afetada quando se analisaram as respostas relaxantes (nitroprussiato de sódio e isoproterenol e contrateis (KCI e prostaglandina 2alfa. Estes achados permitem as seguintes considerrações especulativas: a O barotrauma produzido pela infusão da cardioplegia cristalóide a altas pressões ocorreria apenas em circulações coronarianas previamente doentes? b Uma vez que as infusões duraram de 2 a 3 minutos, seria o barotrauma coronariano um fenômeno dependente do tempo de infusão? c Para que ocorra o barotrauma seriam necessários níveis mais elevados de potássio? d Questionar a existência do fenômeno do barotrauma coronariano produzido pela infusão de soluções cadioplégicas pelo menos nas condições experimentais utilizadas, e A metodologia empregada estuda apenas as reatividades vasculares de artérias coronárias epicárdicas. Estas artérias seriam menos sensíveis aos efeitos da pressão de infusão da cardioplegia do que a microcirculação coronariana? f Seria a circulação coronária do cão menos sensível a altas pressões do que do homem? Estas observações experimentais sugerem que a infusão de cardioplegia cristalóide, moderadamente hipocalêmica, a altas pressõe em um tempo de 2 a 3 minutos, não interfere com a produção de EDRF/NO pelo endotélio de coronárias epicárdicas do cão.Experiments were performed in "organ chambers" to investigate if high pressures infusions of crystalloid cardioplegia

  11. Decay heat removal analyses on the heavy liquid metal cooled fast breeding reactor. Comparisons of the decay heat removal characteristics on lead, lead-bismuth and sodium cooled reactors

    International Nuclear Information System (INIS)

    Sakai, Takaaki; Ohshima, Hiroyuki; Yamaguchi, Akira

    2000-04-01

    The feasibility study on several concepts for the commercial fast breeder reactor(FBR) in future has been conducted in JNC for the kinds of possible coolants and fuel types to confirm the direction of the FBR developments in Japan. In this report, Lead and Lead-Bismuth eutectic coolants were estimated for the decay heat removal characteristics by the comparison with sodium coolant that has excellent features for the heat transfer and heat transport performance. Heavy liquid metal coolants, such as Lead and Lead-Bismuth, have desirable chemical inertness for water and atmosphere. Therefore, there are many economical plant proposals without an intermediate heat transport system that prevents the direct effect on a reactor core by the chemical reaction between water and the liquid metal coolant at the hypocritical tube failure accidents in a steam generator. In this study, transient analyses on the thermal-hydraulics have been performed for the decay heat removal events in Equivalent plant' with the Lead, Lead-Bismuth and Sodium coolant by using Super-COPD code. And a resulted optimized lead cooled plant in feasibility study was also analyzed for the comparison. In conclusion, it is become clear that the natural circulation performance, that has an important roll in passive safety characteristic of the reactor, is more excellent in heavy liquid metals than sodium coolant during the decay heat removal transients. However, we need to confirm the heat transfer reduction by the oxidized film or the corrosion products expected to appear on the heat transfer surface in the Lead and Lead-Bismuth circumstance. (author)

  12. Reduction of lead pollution from vehicular emissions in cairo Part 1: Comparison of alternative solutions

    International Nuclear Information System (INIS)

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

    1996-01-01

    It has been recognized for decades that the major source of lead pollution is lead additives to automotive fuels. This problem has been countered in most countries in europe and Usa by introducing alternative anti-knock chemicals and unleaded gasoline. In egypt lead is still being added to gasoline in large quantities. However, progress has been made, and unleaded gasoline is currently being produced in Alexandria. Nevertheless, the major pollution problem remains in the Greater Cairo region as indicated by the atmospheric lead levels and the lead blood levels of the children in Cairo. The aim of the present study is to find an optimum solution to this problem. A comparison of the different solutions is conducted in order to come up with the most feasible solution to this urgent problem. In conclusion it has been demonstrated that the elimination of lead additives, with its huge positives effects on the country environment, proved to be profitable. 4 figs., 2 tabs

  13. Classical fluoroscopy criteria poorly predict right ventricular lead septal positioning by comparison with echocardiography.

    Science.gov (United States)

    Squara, Fabien; Scarlatti, Didier; Riccini, Philippe; Garret, Gauthier; Moceri, Pamela; Ferrari, Emile

    2018-03-13

    Fluoroscopic criteria have been described for the documentation of septal right ventricular (RV) lead positioning, but their accuracy remains questioned. Consecutive patients undergoing pacemaker or defibrillator implantation were prospectively included. RV lead was positioned using postero-anterior and left anterior oblique 40° incidences, and right anterior oblique 30° to rule out coronary sinus positioning when suspected. RV lead positioning using fluoroscopy was compared to true RV lead positioning as assessed by transthoracic echocardiography (TTE). Precise anatomical localizations were determined with both modalities; then, RV lead positioning was ultimately dichotomized into two simple clinically relevant categories: RV septal or RV free wall. Accuracy of fluoroscopy for RV lead positioning was then assessed by comparison with TTE. We included 100 patients. On TTE, 66/100 had a septal RV lead and 34/100 had a free wall RV lead. Fluoroscopy had moderate agreement with TTE for precise anatomical localization of RV lead (k = 0.53), and poor agreement for septal/free wall localization (k = 0.36). For predicting septal RV lead positioning, classical fluoroscopy criteria had a high sensitivity (95.5%; 63/66 patients having a septal RV lead on TTE were correctly identified by fluoroscopy) but a very low specificity (35.3%; only 12/34 patients having a free wall RV lead on TTE were correctly identified by fluoroscopy). Classical fluoroscopy criteria have a poor accuracy for identifying RV free wall leads, which are most of the time misclassified as septal. This raises important concerns about the efficacy and safety of RV lead positioning using classical fluoroscopy criteria.

  14. Influencia del tamaño del cristal de cinc de láminas de acero galvanizadas en ambientes que contienen cloruros y sulfatos

    Directory of Open Access Journals (Sweden)

    Julieth Andrea Ramírez-Jerez

    2015-05-01

    Full Text Available El trabajo evaluó la influencia del tamaño del cristal de cinc en el comportamiento electroquímico de láminas de acero galvanizadas por inmersión en caliente. Los ensayos se realizaron en una celda electroquímica plana en soluciones con diferentes concentraciones de NaCl y NaSO4. La velocidad y el mecanismo de corrosión, así como las características resistivas y difusivas de las láminas se evaluaron mediante técnicas electroquímicas, como espectroscopia de impedancia electroquímica (EIS, resistencia a la polarización (Rp y curvas potenciodinámicas. La composición y distribución de los productos de corrosión (FeO y algunos compuestos de cinc y el daño superficial causado por estos se determinaron por medio de DRX y SEM-EDS. Los resultados mostraron que la degradación de la capa de óxidos formada se ve afectada por la presencia de cloruros que penetran, llegan a la superficie del metal base y generan corrosión localizada.

  15. Comparison of fuel assemblies in lead cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Perez, A.; Sanchez, H.; Aguilar, L.; Espinosa P, G., E-mail: alejandria.peval@gmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico)

    2016-09-15

    This paper presents a comparison of the thermal-fluid processes in the core, fuel heat transfer, and thermal power between two fuel assemblies: square and hexagonal, in a lead-cooled fast reactor (Lfr). A multi-physics reduced order model for the analysis of Lfr single channel is developed in this work. The work focused on a coupling between process of neutron kinetic, fuel heat transfer process and thermal-fluid, in a single channel. The thermal power is obtained from neutron point kinetics model, considering a non-uniform power distribution. The analysis of the processes of thermal-fluid considers thermal expansion effects. The transient heat transfer in fuel is carried out in an annular geometry, and one-dimensional in radial direction for each axial node. The results presented in comparing these assemblies consider the temperature field in the fuel, in the thermal fluid and under steady state, and transient conditions. Transients consider flow of coolant and inlet temperature of coolant. The mathematical model of Lfr considers three main modules: the heat transfer in the annular fuel, the power generation with feedback effects on neutronic, and the thermal-fluid in the single channel. The modeling of nuclear reactors in general, the coupling is crucial by the feedback between the neutron processes with fuel heat transfer, and thermo-fluid, where is very common the numerical instabilities, after all it has to refine the model to achieve the design data. In this work is considered as a reference the ELSY reactor for the heat transfer analysis in the fuel and pure lead properties for analyzing the thermal-fluid. The results found shows that the hexagonal array has highest temperature in the fuel, respect to square array. (Author)

  16. Comparison of fuel assemblies in lead cooled fast reactors

    International Nuclear Information System (INIS)

    Perez, A.; Sanchez, H.; Aguilar, L.; Espinosa P, G.

    2016-09-01

    This paper presents a comparison of the thermal-fluid processes in the core, fuel heat transfer, and thermal power between two fuel assemblies: square and hexagonal, in a lead-cooled fast reactor (Lfr). A multi-physics reduced order model for the analysis of Lfr single channel is developed in this work. The work focused on a coupling between process of neutron kinetic, fuel heat transfer process and thermal-fluid, in a single channel. The thermal power is obtained from neutron point kinetics model, considering a non-uniform power distribution. The analysis of the processes of thermal-fluid considers thermal expansion effects. The transient heat transfer in fuel is carried out in an annular geometry, and one-dimensional in radial direction for each axial node. The results presented in comparing these assemblies consider the temperature field in the fuel, in the thermal fluid and under steady state, and transient conditions. Transients consider flow of coolant and inlet temperature of coolant. The mathematical model of Lfr considers three main modules: the heat transfer in the annular fuel, the power generation with feedback effects on neutronic, and the thermal-fluid in the single channel. The modeling of nuclear reactors in general, the coupling is crucial by the feedback between the neutron processes with fuel heat transfer, and thermo-fluid, where is very common the numerical instabilities, after all it has to refine the model to achieve the design data. In this work is considered as a reference the ELSY reactor for the heat transfer analysis in the fuel and pure lead properties for analyzing the thermal-fluid. The results found shows that the hexagonal array has highest temperature in the fuel, respect to square array. (Author)

  17. Identification and comparison of lead white of the 15-th century Gdansk panel paintings by neutron activation analysis

    International Nuclear Information System (INIS)

    Olszewska-Swietlik, J.; Panczyk, E.

    2005-01-01

    The lead white has been used in painting science the middle ages both as a priming ground and pigment. Purity of the lead white is directly connected with the lead purification methods that have undergone considerable changes throughout centuries. Marked progress in this respect was noted in the 19-th century. That is why determination of such elements a Ag, Hg, Zn, Cu, Co, Cr, Ba and Sb in the lead white gives reliable information regarding the age of the painting in question. Analyses of samples of the lead white taken from genuine 15-th century panel paintings representing the so-called Pomeranian school were carried out using instrumental neutron activation analysis technique. The total of 32 elements were determined in those samples; also the comparison of the data for Malopolska and Silesian schools was performed. (author)

  18. Comparison between steel and lead shieldings for radiotherapy rooms regarding neutron doses to patients

    International Nuclear Information System (INIS)

    Silva, M.G.; Rebello, W.F.; Andrade, E.R.; Medeiros, M.P.C.; Mendes, R.M.S.; Braga, K.L.; Gomes, R.G.

    2015-01-01

    The NCRP Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities, considers, in shielding calculations for radiotherapy rooms, the use of lead and/or steel to be applied on bunker walls. The NCRP Report calculations were performed foreseeing a better protection of people outside the radiotherapy room. However, contribution of lead and steel to patient dose should be taken into account for radioprotection purposes. This work presents calculations performed by MCNPX code in analyzing the Ambient Dose Equivalent due to neutron, H *(10) n , within a radiotherapy room, in the patients area, considering the use of additional shielding of 1 TVL of lead or 1 TVL of steel, positioned at the inner faces of walls and ceiling of a bunker. The head of the linear accelerator Varian 2100/2300 C/D was modeled working at 18MeV, with 5 x 5 cm 2 , 10 x 10 cm 2 , 20 x 20 cm 2 , 30 x 30 cm 2 and 40 x 40 cm 2 openings for jaws and MLC and operating in eight gantry's angles. This study shows that the use of lead generates an average value of H *(10) n at patients area, 8.02% higher than the expected when using steel. Further studies should be performed based on experimental data for comparison with those from MCNPX simulation. (author)

  19. Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M; Guibert, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

  20. Calculo de funciones de onda lcao para el estado fundamental de solidos. aplicación al estudio teórico de la estructura de los cristales de litio y de nitruro de boro. I.

    Directory of Open Access Journals (Sweden)

    Nepomuceno Quitian C.

    2009-07-01

    Full Text Available En esta primera publicación se ha aplicado el formulismo de la Química Cuántica del Estado Sólido, al estudio teórico de los cristales de Litio y de Nitruro de Boro, utilizando una base de funciones Gausianas dentro del método LCAO— SCF—MO (Linear Combination of Atomic Orbitals- Self Consistent Fields – Molecular Orbltals. Se calculan los factores de estructura teóricos a partir de los elementos de la matriz de densidad y las integrales de recubrimiento Generalizadas. Se calcula igualmente la densidad electrónica y una función delta (A a partir de los factores de estructura teóricos, con el fin de poner en evidencia la unión Química.

  1. Comparison of five in vitro digestion models to in vivo experimental results: Lead bioaccessibility in the human gastrointestinal tract

    NARCIS (Netherlands)

    Wiele, T.R. van de; Oomen, A.G.; Wragg, J.; Cave, M.; Minekus, M.; Hack, A.; Cornelis, C.; Rompelberg, C.J.M.; Zwart, L.L. de; Klinck, B.; Wijnen, J. van; Verstraete, W.; Sips, A.J.A.M.

    2007-01-01

    This paper presents a multi-laboratory comparison study of in vitro models assessing bioaccessibility of soil-bound lead in the human gastrointestinal tract under simulated fasted and fed conditions. Oral bioavailability data from a previous human in vivo study on the same soil served as a reference

  2. Comparison between steel and lead shieldings for radiotherapy rooms regarding neutron doses to patients

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.G.; Rebello, W.F.; Andrade, E.R.; Medeiros, M.P.C.; Mendes, R.M.S.; Braga, K.L.; Gomes, R.G., E-mail: eng.cavaliere@gmail.com, E-mail: ggrprojetos@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear; Silva, A.X., E-mail: ademir@con.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The NCRP Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities, considers, in shielding calculations for radiotherapy rooms, the use of lead and/or steel to be applied on bunker walls. The NCRP Report calculations were performed foreseeing a better protection of people outside the radiotherapy room. However, contribution of lead and steel to patient dose should be taken into account for radioprotection purposes. This work presents calculations performed by MCNPX code in analyzing the Ambient Dose Equivalent due to neutron, H *(10){sub n}, within a radiotherapy room, in the patients area, considering the use of additional shielding of 1 TVL of lead or 1 TVL of steel, positioned at the inner faces of walls and ceiling of a bunker. The head of the linear accelerator Varian 2100/2300 C/D was modeled working at 18MeV, with 5 x 5 cm{sup 2}, 10 x 10 cm{sup 2}, 20 x 20 cm{sup 2}, 30 x 30 cm{sup 2} and 40 x 40 cm{sup 2} openings for jaws and MLC and operating in eight gantry's angles. This study shows that the use of lead generates an average value of H *(10){sub n} at patients area, 8.02% higher than the expected when using steel. Further studies should be performed based on experimental data for comparison with those from MCNPX simulation. (author)

  3. Association of Lead Exposure, Serum Uric Acid and Parameters of Renal Function in Nigerian Lead-Exposed Workers

    Directory of Open Access Journals (Sweden)

    DD Alasia

    2010-09-01

    Full Text Available Background: The presence of hyperuricemia and renal function impairment, especially in the absence of urate stone formation is strongly suggestive of lead nephropathy. The evaluation of this association is essential in areas where lead exposure is still prevalent and uncontrolled. Objective: To determine the relationship between serum uric acid and renal function indices in lead-exposed workers. Methods: A cross-sectional study of 190 adults with occupational lead exposure and 80 adults (comparison group, matched for age and sex was performed in Port Harcourt, South-south Nigeria. Blood lead was used as the biomarker of lead exposure while serum urea, serum creatinine, urine albumin (using urine albumin:creatinine ratio, estimated glomerular filtration rate (GFR and serum uric acid were the renal function indices measured. Results: Occupationally lead-exposed subjects had a significantly (p = 0.008 higher mean±SD blood lead levels (50.37±24.58 μg/dL than the comparison group (41.40±26.85. The mean±SD serum urea (8.6±2.3 mg/dL, creatinine (1.0±0.2 mg/dL and serum uric acid (4.6±1.2 mg/dL were significantly (p < 0.01 higher in the study subjects than the comparison group (7.6±2.4, 0.9±0.2, and 3.9±1.1 mg/dL, respectively. The mean±SD creatinine clearance was significantly (p = 0.002 lower in the study subjects than the comparison group (98.9±21.3 vs. 108.2±25.2 mL/min/1.72 m2. Serum uric acid level correlated positively with serum creatinine (r = 0.134 and negatively with GFR (r = ‑0.151. Conclusion: People with occupational lead exposure are at risk of developing hyperuricemia and renal impairment.

  4. 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...

  5. Thermal restoration of the lattice parameter of weakly irradiated UO2 (1962)

    International Nuclear Information System (INIS)

    Bloch, J.

    1962-01-01

    Weak irradiations of uranium dioxide lead to an expansion of the cristal lattice. We have studied the restoration of the lattice parameter after successive isochronous annealings. The process occurs in two main stages, one starting at 200 deg. C and the other at 500 deg. C. (author) [fr

  6. Sistema Oscilador Mejorado para Aplicaciones de Microbalanza (QCM) en Medios Líquidos y Propuesta de un Nuevo Método de Caracterización para Biosensores Piezoeléctricos

    OpenAIRE

    MONTAGUT FERIZZOLA, YEISON JAVIER

    2011-01-01

    La microbalanza de cristal de cuarzo (QCM) se usa como técnica alternativa de análisis químico, donde las aplicaciones dependen directamente de la sensibilidad del cristal. Por tanto, es el parámetro más importante que determina el uso de los cristales de cuarzo frente a otras técnicas. La ecuación de Sauerbrey, teóricamente relaciona la variación de la densidad de masa en la superficie del cristal con el cambio de la frecuencia y al mismo tiempo predice que la sensibilidad aumenta en la mis...

  7. Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

    Science.gov (United States)

    Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

    2013-09-30

    Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

  8. Simulació d'un procés industrial de cristallització de clorur de sodi (NaCl i aplicacions

    Directory of Open Access Journals (Sweden)

    Josefina Renedo Omaechevarría

    2014-12-01

    Full Text Available La cristal·lització a partir de dissolucions és important industrialment  donada la gran varietat de substàncies que es comercialitzen  cristal·litzades. Per millorar el procés  d’ensenyament-aprenentatge d’aquesta “Operació Bàsica”, en aquest treball, realitzat com a Treball de Fi de Carrera de la titulació  d’ Enginyeria Química, s’ha  desenvolupat un programa de simulació d’una cristal·lització industrial de NaCl.  L’objectiu ha sigut manejar  eines de càlcul  per simular  i optimitzar una cristal·lització, la qual cosa permet conèixer més profundament el procés de la cristal·lització i la utilització de les eines de càlcul, és a dir, utilitzar simultàniament els coneixements adquirits en les assignatures de Operacions amb Sòlid  i la de Simulació i Optimització de Processos. L’objectiu últim de l’ús d’aquest programa de simulació és que els estudiants de l’assignatura optativa Operacions  amb Sòlids del Grau en Enginyeria Química puguin fer servir aquest recurs a l’aula. Amb el programa utilitzat, en llenguatge Fortran, obtenim, d’una manera ràpida i eficaç, la velocitat de creixement dels cristalls G i la velocitat de nucleació B. Un cop calculats els valors de G i B, es pot programar una cristal·lització per obtenir  la distribució de tamany de cristall (DTC desitjat. Per últim s´han determinat els valors dels paràmetres cinètiques de B0.

  9. Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M.; Guibert, B. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

  10. Effect on blood lead of airborne lead particles characterized by size.

    Science.gov (United States)

    Park, Dong-Uk; Paik, Nam-Won

    2002-03-01

    Worker exposure to airborne lead particles was evaluated for a total of 117 workers in 12 work-places of four different industrial types in Korea. The particle sizes were measured using 8-stage cascade impactors worn by the workers. Mass median aerodynamic diameters (MMAD) were determined by type of industry and percentage of lead particles as a fraction of airborne lead (PbA) concentration was determined by particle size. Blood lead (PbB) levels of workers who matched airborne lead samples were also examined. A Scheffé's pairwise comparison test showed that MMAD and the fractions of each of respirable particles and lead particles lead particles lead particles (r = 0.82) than that between concentrations of small particles and PbA (r = 0.61). A simple linear regression indicated that PbB correlated better with respirable lead concentration (r2 = 0.35, P = 0.0001) than with PbA concentration and had a higher slope coefficient. Controlling for respirable lead concentration reduced the partial correlation coefficient between PbA concentration and PbB level from 0.56 to 0.20 (P = 0.053). The results indicate that the contribution of respirable lead particles to lead absorption would be greater than that of PbA. This study concludes that the measurement of PbA only may not properly reflect a worker's exposure to lead particles with diverse characteristics. For the evaluation of a worker's exposure to various types of lead particles, it is recommended that respirable lead particles as well as PbA be measured.

  11. Skin toxicology of lead species evaluated by their permeability and proteomic profiles: a comparison of organic and inorganic lead.

    Science.gov (United States)

    Pan, Tai-Long; Wang, Pei-Wen; Al-Suwayeh, Saleh A; Chen, Chih-Chieh; Fang, Jia-You

    2010-08-01

    Lead compounds are known to cause cytotoxicity and genotoxicity. Lead absorption by the skin is an important route through which this metal enters the body. The purpose of this work was to evaluate the skin permeability and toxicological profiles of two lead species, lead acetate and lead nitrate. This study assessed lead-induced toxicity mechanisms by focusing on the histopathology, proteomics, cell growth, and cellular ATP. In vitro skin permeation assays showed that there was no significant difference of lead accumulation within and across the skin between the two lead species. The presence of simulated sweat reduced the skin uptake of lead. The skin deposition of lead acetate was greater than that of lead nitrate with in vivo topical application. On the other hand, lead nitrate produced greater changes in the skin's histology and proteomic profiles compared to lead acetate. Four protein spots which showed significant changes were identified and are discussed in this study. These included glucose-related protein precursor (GRP) 78, K14, alpha-actin, and Rho GDP-dissociation inhibitor 2 (RhoGDI2). These proteins are respectively associated with oxidative stress, apoptosis, wound healing, and proliferation. Lead presented a biphasic pattern on cell growth and intracellular ATP content, with a stimulating effect at low concentrations and an inhibitory effect on cell proliferation at higher concentrations. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  12. Investigation into the structure of lead-borate glass

    International Nuclear Information System (INIS)

    Kurtsinovskaya, R.I.

    1976-01-01

    X-ray phase and IR analysis of lead borate glasses show that glasses containing from 12 to 45 mole % PbO consist of several phases. A comparison of x-ray different data for lead borate and lead germanate glasses, which have two maxima on the diffraction patterns throughout the glass-formation region, shows that the microstructure of lead borate glasses is far more complex

  13. Actinides critical masses and the Paxton Woodcock rule

    International Nuclear Information System (INIS)

    Anno, Jacques; Duhamel, Isabelle; Lavarenne, Caroline; Duluc, Matthieu

    2003-01-01

    This paper presents recent actinides (reflected or not, moderated or not) critical masses calculations performed by the French standard route (APOLLO2 Sn 8 P3, 20 energy groups cross-section collapsed from 172 energy groups CEA 93 library). Comparisons are also presented against more accurate routes of the French criticality package CRISTAL, showing the fair conservatism of the standard values. Checks of the Paxton Woodcock rule for transportation exemption limit were also made. (author)

  14. Actinides critical masses and the Paxton Woodcock rule

    Energy Technology Data Exchange (ETDEWEB)

    Anno, Jacques; Duhamel, Isabelle; Lavarenne, Caroline [Institut de Radioprotection et de Surete Nucleaire, Fontenay aux Roses (France); Duluc, Matthieu [Institut National des Sciences et Techniques Nucleaires (INSTN) (France)

    2003-10-01

    This paper presents recent actinides (reflected or not, moderated or not) critical masses calculations performed by the French standard route (APOLLO2 Sn 8 P3, 20 energy groups cross-section collapsed from 172 energy groups CEA 93 library). Comparisons are also presented against more accurate routes of the French criticality package CRISTAL, showing the fair conservatism of the standard values. Checks of the Paxton Woodcock rule for transportation exemption limit were also made. (author)

  15. A Component Based Approach to Scientific Workflow Management

    CERN Document Server

    Le Goff, Jean-Marie; Baker, Nigel; Brooks, Peter; McClatchey, Richard

    2001-01-01

    CRISTAL is a distributed scientific workflow system used in the manufacturing and production phases of HEP experiment construction at CERN. The CRISTAL project has studied the use of a description driven approach, using meta- modelling techniques, to manage the evolving needs of a large physics community. Interest from such diverse communities as bio-informatics and manufacturing has motivated the CRISTAL team to re-engineer the system to customize functionality according to end user requirements but maximize software reuse in the process. The next generation CRISTAL vision is to build a generic component architecture from which a complete software product line can be generated according to the particular needs of the target enterprise. This paper discusses the issues of adopting a component product line based approach and our experiences of software reuse.

  16. A component based approach to scientific workflow management

    International Nuclear Information System (INIS)

    Baker, N.; Brooks, P.; McClatchey, R.; Kovacs, Z.; LeGoff, J.-M.

    2001-01-01

    CRISTAL is a distributed scientific workflow system used in the manufacturing and production phases of HEP experiment construction at CERN. The CRISTAL project has studied the use of a description driven approach, using meta-modelling techniques, to manage the evolving needs of a large physics community. Interest from such diverse communities as bio-informatics and manufacturing has motivated the CRISTAL team to re-engineer the system to customize functionality according to end user requirements but maximize software reuse in the process. The next generation CRISTAL vision is to build a generic component architecture from which a complete software product line can be generated according to the particular needs of the target enterprise. This paper discusses the issues of adopting a component product line based approach and our experiences of software reuse

  17. Lead isotopic compositions of environmental certified reference materials for an inter-laboratory comparison of lead isotope analysis

    International Nuclear Information System (INIS)

    Aung, Nyein Nyein; Uryu, Tsutomu; Yoshinaga, Jun

    2004-01-01

    Lead isotope ratios, viz. 207 Pb/ 206 Pb and 208 Pb/ 206 Pb, of the commercially available certified reference materials (CRMs) issued in Japan are presented with an objective to provide a data set, which will be useful for the quality assurance of analytical procedures, instrumental performance and method validation of the laboratories involved in environmental lead isotope ratio analysis. The analytical method used in the present study was inductively coupled plasma quadrupole mass spectrometry (ICPQMS) presented by acid digestion and with/without chemical separation of lead from the matrix. The precision of the measurements in terms of the relative standard deviation (RSD) of triplicated analyses was 0.19% and 0.14%, for 207 Pb/ 206 Pb and 208 Pb/ 206 Pb, respectively. The trueness of lead isotope ratio measurements of the present study was tested with a few CRMs, which have been analyzed by other analytical methods and reported in various literature. The lead isotopic ratios of 18 environmental matrix CRMs (including 6 CRMs analyzed for our method validation) are presented and the distribution of their ratios is briefly discussed. (author)

  18. Experimental lead intoxication in dogs: a comparison of blood lead and urinary delta-aminolevulinic acid following intoxication and chelation therapy.

    Science.gov (United States)

    Green, R A; Selby, L A; Zumwalt, R W

    1978-01-01

    Intravenous lead administration to dogs produced an acute syndrome of lead intoxication charcterized by depression, vomiting, anorexia and weight loss. The effect of chelation therapy with calcium disodium ethylene diamine tetraacetate, penicillamine or both was determined by serially monitoring changes in blood lead and urine delta-aminolevulinic acid. Following therapy, blood lead values were significantly lower in chelated dogs than non-treated lead exposed dogs on days 7 and 10. Urine delta-aminolevulinic acid at day 7 was significantly higher in untreated lead exposed dogs than in other groups. There was no significant difference in blood lead or urine delta-aminolevulinic acid between lead intoxicated dogs which underwent the indicated chelation therapy protocols. There was, however, a trend for higher urinary delta-aminolevulinic acid excretion in those intoxicated dogs undergoing calcium disodium ethylene diamine tetraacetate therapy as opposed to those undergoing penicilamine therapy. There was no significant correlation between blood lead and urinary delta-aminolevulinic acid previous to lead exposure. However, after lead exposure significant correlation was present at days 4, 7, 10 and 14. Certain lead exposed dogs following chelation therapy were noted to have normal blood lead levels but elevated urinary delta-aminolevulinic acid suggesting that blood lead does not always correlate with metabolic effects of lead in the body. Urinary delta-aminolevulinic acid was therefore recommended as an additional laboratory parameter which improved assessment of lead exposure in dogs, particularly in determining adequacy of chelation therapy. PMID:667707

  19. X-ray protective clothing. Does DIN 6857-1 allow an objective comparison between lead-free and lead-composite materials?

    International Nuclear Information System (INIS)

    Eder, H.; Schlattl, H.; Hoeschen, C.

    2010-01-01

    Purpose: The validity of DIN 6857-1 to establish lead equivalence for protective clothing is evaluated by Monte Carlo simulations and measurements. Materials and Methods: Commercially available protective clothing made of lead, lead-free and lead-composite materials has been tested regarding its protective efficacy. The analysis has been performed on the one hand in accordance with the test conditions described in the manufacturing standard DIN EN 61331-3 and on the other hand following the new DIN 6857-1 standard. Additionally, measurements have been carried out under simulated patient conditions by using an Alderson-Rando phantom. Results: Following DIN EN 61331-3, the lead-free protective clothing achieved the required protective efficacy only at a restricted tube-voltage range. The test according to DIN 6857-1 showed that the protective criteria were fulfilled only by one lead-composite apron, but not by the three lead-free aprons examined. Thus, in order to guarantee the same protection as lead between 50 and 120 kV, the conditions of DIN 6857-1 must be fulfilled. Conclusion: A modification of DIN EN 61331-3 to account for secondary radiation is strongly advised in the case of lead-free materials. In summary, most of the protective lead-free aprons in use should be used with care, particularly for examinations with a high dose. (orig.)

  20. Comparison of the key mechanisms leading to rollovers in Liquefied Natural Gas using Computational Fluid Dynamics

    Science.gov (United States)

    Hubert, Antoine; Dadonau, Maksim; Dembele, Siaka; Denissenko, Petr; Wen, Jennifer

    2017-11-01

    Growing demand for the LNG fosters growth of the number of production sites with varying composition and density. Combining different sources of LNG may result in a stably stratified system, in which heat and mass transfer between the layers is limited. Heating of the LNG due to wall thermal conductivity leads to formation of convection cells confined within the layers. While the upper layer can release the extra energy via preferential methane boil-off, the bottom layer cannot and hence becomes superheated. Gradual density equilibration reduces stratification and may eventually lead to a sudden mixing event called ``rollover'', accompanied by violent evaporation of the superheated LNG. Three phenomena are potentially responsible for density equilibration. The first is the growing difference in thermal expansion of the layers due to the reduced ability of the bottom layer to reject heat. The second is the penetration of the heated near-wall boundary layer into the upper layer. The third is the ``entrainment mixing'' occurring at the contact surface between the two layers. The present study uses CFD to compare these mechanisms. Boussinesq approximation and an extended version of the k- ɛ model is used. The code is validated by comparison with a large-scale LNG rollover experiment.

  1. Comparison of the U.S. lead recycling industry in 1998 and 2011

    Science.gov (United States)

    Wilburn, David R.

    2014-01-01

    Since 1998, the structure of the lead recycling industry has changed and trade patterns of the domestic lead recycling industry have shifted. Although the domestic demand for lead has remained relatively constant since 1998, production of lead has increasingly shifted to the domestic secondary lead industry. The last primary lead smelter in the United States closed at the end of 2013, at which time the secondary lead industry became the sole source of domestic lead production. The amount of lead recovered annually from scrap batteries generally increased from about 900,000 metric tons in 1995 to more than 1,100,000 metric tons in 2012. The percentage of total U.S. lead production attributed to battery scrap increased from 65 percent in 1995 to 87 percent in 2012. Since the North American Free Trade Agreement took effect in 1994, trade patterns among the United States, Canada, and Mexico have changed for recycled lead products. In the late 1990s, the principal sources of lead waste and scrap not derived from batteries were Canada, Mexico, and South America; by 2011, the principal sources were Central America and Asia, with decreasing amounts from Canada and South America. Since 1998, the amount of lead derived from imported batteries and scrap from Canada has ranged from 50 to 90 percent, and the amount imported from Mexico has ranged from 3 to 20 percent. Canada received about 50 percent of the lead contained in spent lead-acid batteries and scrap exported from the United States in 1998, and Mexico received about 4 percent. By 2012, however, the amount of lead scrap exported to Canada had decreased to about 10 percent, and the amount of lead-based scrap products, primarily batteries, exported to Mexico from the United States had increased to 47 percent. Vertical integration of the domestic secondary lead industry and higher costs required to implement more stringent ambient air standards in the United States have led some companies to shift lead recycling

  2. Efeito protetor da criocardioplegia cristalóide na isquemia global e reperfusão durante circulação extracorpórea: um mecanismo dependente do endotélio?

    Directory of Open Access Journals (Sweden)

    ÉVORA Paulo Roberto B

    1997-01-01

    Full Text Available Estudos prévios demonstraram que o comprometimento da produção de EDRF/NO mediada por receptores, após isquemia global e reperfusão, possa ser devido a uma disfunção de G-proteínas que liga os receptores da célula endotelial à via da síntese de EDRF/NO. O presente trabalho experimental sugere que a criocardioplegia cristalóide, associada a hipotermia tópica, previne ou pode reverter, em parte, a disfunção endotelial nas mesmas condições. Mais estudos serão necessários para conclusões mais definitivas, pois as análises estatísticas mais acuradas sugeriram aumento da amostragem. Este detalhe talvez seja devido às grandes dificuldades de uniformização relacionada a este tipo de experimentos. Além disso, demonstrou-se pela primeira vez que a hipotermia, por si só, pode estimular a liberação de EDRF/NO pelo endotélio vascular. Isto sugere que o endotélio possa ser um importante sensor de mudanças da temperatura sangüínea e tem importantes implicações para o entendimento da fisiologia da CEC e dos mecanismos locais de auto-regulação.

  3. Electrophysiological performance of a bipolar membrane-coated titanium nitride electrode: a randomized comparison of steroid and nonsteroid lead designs.

    Science.gov (United States)

    Wiegand, U K; Zhdanov, A; Stammwitz, E; Crozier, I; Claessens, R J; Meier, J; Bos, R J; Bode, F; Potratz, J

    1999-06-01

    The aim of this multicenter study was to investigate the performance of a new cardiac pacemaker lead with a titanium nitride cathode coated with a copolymer membrane. In particular, the electrophysiological effect of steroid dissolved in this ion-exchange membrane was evaluated by randomized comparison. Ninety-five patients were randomized either to the 1450 T (n = 51) or the 1451 T ventricular lead (n = 45) and received telemeteral VVI(R) pacemakers with identical diagnostic features. Both leads were bipolar, were passively affixed, and had a porous titanium nitride tip with a surface area of 3.5 mm2. The only difference between the two electrodes was 13 micrograms of dexamethasone added to the 1450 Ts membrane coating. Voltage thresholds (VTH) at pulse durations of 0.25, 0.37, and 0.5 ms, lead impedance, and sensing thresholds were measured at discharge, 2 weeks, 1 month, 3 months, and 6 months after implantation. Mean amplitude and the slew rate from three telemetered intracardiac electrograms, chronaxie-rheobase product, and minimum energy consumption were calculated. After a 6-month follow-up, mean voltage thresholds of 0.65 +/- 0.20 V and 0.63 +/- 0.34 were achieved for the 1450 T lead and 1451 T lead, respectively. As a result, a VTH < 1.0 V was obtained in all patients with 1450 T electrodes and in 97.7% of patients with 1451 T leads after 6 months follow-up. In both electrodes, stable VTH was reached 2 weeks after implantation, and no transient rise in threshold was observed. No differences were observed between the steroid and the nonsteroid group in respect to VTH, chronaxie-rheobase product, minimum energy consumption, and potential amplitude and slew rate. In conclusion, safe and efficient pacing at low pulse amplitudes were achieved with both leads. The tip design, independently of the steroid additive, prevented any energy-consuming increases in the voltage threshold.

  4. The use of steel and lead shieldings in radiotherapy rooms and its comparison with respect to neutrons doses at patients

    International Nuclear Information System (INIS)

    Silva, M.G.; Rebello, W.F.; Andrade, E.R.; Medeiros, M.P.C.; Mendes, R.M.S.; Braga, K.L.; Gomes, R.G.; Santos, R.F.G.

    2015-01-01

    The NCRP Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities, considers, in shielding calculations for radiotherapy rooms, the use of lead and/or steel to be applied on bunker walls. The NCRP Report calculations were performed foreseeing a better protection of people outside the radiotherapy room. However, contribution of lead and steel to patient dose should be taken into account for radioprotection purposes. This work presents calculations performed by MCNPX code in analyzing the Ambient Dose Equivalent due to neutron, H*(10) n , within a radiotherapy room, in the patients area, considering the use of additional shielding of 1 TVL of lead or 1 TVL of steel, positioned at the inner faces of walls and ceiling of a bunker. The head of the linear accelerator Varian 2100/2300 C/D was modeled working at 18MeV, with 5x5cm 2 , 10x10cm 2 , 20x20cm 2 , 30x30cm 2 and 40x40cm 2 openings for jaws and MLC and operating in eight gantry's angles. This study shows that the use of lead generates an average value of H*(10) n at patients area, 8.02% higher than the expected when using steel. Further studies should be performed based on experimental data for comparison with those from MCNPX simulation.

  5. The next-to-leading order (NLO) gluon distribution from DGLAP ...

    Indian Academy of Sciences (India)

    leading order (NLO) is obtained by applying the method of characteristics. Its compatibility with double leading logarithmic approximation (DLLA) asymptotics is discussed and comparison with the exact ones like GRV98NLO is made. The solution ...

  6. Perspective on Lead Toxicity, a Comparison between the United States and Iran

    Directory of Open Access Journals (Sweden)

    Maryann Amirshahi

    2012-10-01

    Full Text Available Lead is a pervasive toxin that has been implicated in human poisonings throughout history.Exposure mitigation strategies in the United States and worldwide have led to a decline in symptomatic poisonings and population blood lead levels; however, lead remains a major health hazard. In this article, we review the history of lead toxicity, clinical manifestations ranging from subclinical and subtle features to life-threatening complications, and thesubsequent public health interventions in the US. In addition, we explore common routes of lead exposure and the unique differences between the US and Iran. Although the US has made significant strides with regard to this public health issue, lead poisoning in both countries continues to be a health hazard in the adult and pediatric populations. It is also critical to consider natural disasters and reconstruction efforts as potential sources of leadcontamination. In conclusion, we make recommendations that both the US and Iranian authorities can implement to eradicate lead as a public health hazard.

  7. 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

  8. Variability in the Anthropometric Status of Four South African ...

    African Journals Online (AJOL)

    Variability in the Anthropometric Status of Four South African Populations. PJ Smith. Abstract. Coefficients of variation (V) of 4 populations were compared for each of 11 parameters. Males differed significantly in cristal height and 3 skinfolds. It has been suggested that negroids vary more in relation to their means in cristal ...

  9. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK.

    Science.gov (United States)

    Rothwell, James J; Evans, Martin G; Lindsay, John B; Allott, Timothy E H

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably.

  10. Biological fractionation of lead isotopes in Sprague-Dawley rats lead poisoned via the respiratory tract.

    Directory of Open Access Journals (Sweden)

    Jing Wu

    Full Text Available It was considered that lead isotope ratios did not change during physical, chemical, or biological processes. Thus, lead isotope ratios have been used as fingerprints to identify possible lead sources. However, recent evidence has shown that the lead isotope ratios among different biological samples in human are not always identical from its lead origins in vitro. An animal experiment was conducted to explore the biological fractionation of lead isotopes in biological systems.24 male Sprague-Dawley (SD rats were divided into groups that received acute lead exposure (0, 0.02, 0.2, or 2 mg/kg body weight of lead acetate via the respiratory route every day for 5 days. Biological samples (i.e., blood, urine, and feces were collected for comparison with the lead acetate (test substance and the low-lead animal feed (diet administered to the rats. The lead isotope ratios were determined by inductively coupled plasma mass spectrometry (ICP-MS.There are significant differences (p<0.05 in lead isotope ratios between blood, urine, and feces. Moreover, a nonlinear relationship between the blood lead concentration and the blood lead isotope ratios was observed. There is also a threshold effect to the fractionation function. Only the blood isotope ratio of (204Pb/(206Pb matches the test substance well. As for feces, when (204Pb/(206Pb ratio is considered, there is no significant difference between feces-test substance pairs in medium and high dose group.The biological fractionation of lead isotopes in SD rats was observed. Moreover, there might be a threshold for the biological fractionation of lead isotopes which is depending on whole blood lead level. It is considered to be more reliable that we compared the isotope ratios of potential lead hazards with both blood and feces lead fingerprints especially for (204Pb/(206Pb ratio under high-dose exposure.

  11. 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.

  12. Comparison of lead removal behaviors and generation of water-soluble sodium compounds in molten lead glass under a reductive atmosphere

    Science.gov (United States)

    Okada, Takashi; Nishimura, Fumihiro; Xu, Zhanglian; Yonezawa, Susumu

    2018-06-01

    We propose a method of reduction-melting at 1000 °C, using a sodium-based flux, to recover lead from cathode-ray tube funnel glass. To recover the added sodium from the treated glass, we combined a reduction-melting process with a subsequent annealing step at 700 °C, generating water-soluble sodium compounds in the molten glass. Using this combined process, this study compares lead removal behavior and the generation of water-soluble sodium compounds (sodium silicates and carbonates) in order to gain fundamental information to enhance the recovery of both lead and sodium. We find that lead removal increases with increasing melting time, whereas the generation efficiency of water-soluble sodium increases and decreases periodically. In particular, near 90% lead removal, the generation of water-soluble sodium compounds decreased sharply, increasing again with the prolongation of melting time. This is due to the different crystallization and phase separation efficiencies of water-soluble sodium in molten glass, whose structure continuously changes with lead removal. Previous studies used a melting time of 60 min in the processes. However, in this study, we observe that a melting time of 180 min enhances the water-soluble sodium generation efficiency.

  13. Interlaboratory Comparison of Lead and Cadmium in Blood, Urine, and Aqueous Solutions

    DEFF Research Database (Denmark)

    Paulev, P. E.; Solgaard, Per Bent; Tjell, Jens Christian

    1978-01-01

    Analysis for lead and cadmium in biological liquids (blood and urine) is difficult. Results of such analyses from five laboratories are compared for samples with known additions of lead and cadmium. The data, evaluated in terms of inter- and intralaboratory reproducibility and accuracy, suggest t...... that laboratories should voluntarily participate in quality control programs. Users of routine laboratories are advised to use their own quality control program......Analysis for lead and cadmium in biological liquids (blood and urine) is difficult. Results of such analyses from five laboratories are compared for samples with known additions of lead and cadmium. The data, evaluated in terms of inter- and intralaboratory reproducibility and accuracy, suggest...

  14. Biological fractionation of lead isotopes in Sprague-Dawley rats lead poisoned via the respiratory tract.

    Science.gov (United States)

    Wu, Jing; Liu, Duojian; Xie, Qing; Wang, Jingyu

    2012-01-01

    It was considered that lead isotope ratios did not change during physical, chemical, or biological processes. Thus, lead isotope ratios have been used as fingerprints to identify possible lead sources. However, recent evidence has shown that the lead isotope ratios among different biological samples in human are not always identical from its lead origins in vitro. An animal experiment was conducted to explore the biological fractionation of lead isotopes in biological systems. 24 male Sprague-Dawley (SD) rats were divided into groups that received acute lead exposure (0, 0.02, 0.2, or 2 mg/kg body weight of lead acetate) via the respiratory route every day for 5 days. Biological samples (i.e., blood, urine, and feces) were collected for comparison with the lead acetate (test substance) and the low-lead animal feed (diet) administered to the rats. The lead isotope ratios were determined by inductively coupled plasma mass spectrometry (ICP-MS). There are significant differences (pblood, urine, and feces. Moreover, a nonlinear relationship between the blood lead concentration and the blood lead isotope ratios was observed. There is also a threshold effect to the fractionation function. Only the blood isotope ratio of (204)Pb/(206)Pb matches the test substance well. As for feces, when (204)Pb/(206)Pb ratio is considered, there is no significant difference between feces-test substance pairs in medium and high dose group. The biological fractionation of lead isotopes in SD rats was observed. Moreover, there might be a threshold for the biological fractionation of lead isotopes which is depending on whole blood lead level. It is considered to be more reliable that we compared the isotope ratios of potential lead hazards with both blood and feces lead fingerprints especially for (204)Pb/(206)Pb ratio under high-dose exposure.

  15. Lead neurotoxicity: In vitro and in vivo effects

    International Nuclear Information System (INIS)

    Rowles, T.K.

    1989-01-01

    Neuroglial cells, in particular astroglia, are thought to play a role in the neurotoxicity of lead. Two hypotheses have been proposed as possible cellular mechanism of this neurotoxicity: (1) lead affects intracellular levels of metals which mediate the toxic effects noted, and (2) lead affects intracellular heme biosynthesis which is then toxic to the cells. Zinc was found to have a profound effect on both intracellular lead levels and on cell numbers in lead-treated rat astroglia. A comparison of bovine and rat astroglia in culture indicated that the bovine cell cultures were not more sensitive to lead, even though calves are more sensitive. Lead was also shown to affect intracellular heme biosynthesis by a decrease in 14 C aminolevulinic acid incorporation into extractable heme in lead-treated rat astroglia. Finally, low levels of lead in immature guinea pigs caused changes in tissue levels of lead, iron, copper, and zinc with no change in weight gain or body:brain weight ratios

  16. Influência do açúcar no processo de cicatrização de incisões cirúrgicas infectadas Influencia del azúcar en el proceso de cicatrización de insiciones quirúrgicas infectadas A microbiological study about the effect of sugar on the scarring of infected surgical incisions

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Lourenço Haddad

    2000-01-01

    Full Text Available Trata-se de um estudo experimental, realizado através de análises microbiológicas, que teve por objetivo avaliar a influência do açúcar cristal no processo de cicatrização de incisões cirúrgicas infectadas de 25 pacientes. Nas deiscências foram identificadas as presenças de bactérias gram positivas, gram negativas e fungos. Todos os indivíduos receberam antibioticoterapia sistêmica e tiveram suas incisões tratadas localmente com açúcar cristal, através de 3 curativos diários. A análise estatística demonstrou, através da correlação de Pearson, que o açúcar cristal não influenciou o processo de cicatrização de incisões cirúrgicas infectadas de indivíduos desnutridos, obesos e com idade avançada.Se trata de un estudio experimental, realizado a través de análisis microbiológicos, que tuvo como objetivo evaluar la influencia del azúcar cristal en el proceso de cicatrización de incisiones quirúrgicas infectadas de 25 pacientes. En las dehiscencias fue identificada la presencia de bacterias "gram positivas", "gram negativas y hongos. Todos los individuos recibieron antibioticoterápia sistémica y tuvieron sus incisiones tratadas localmente con azúcar cristal, a través de tres curaciones diarias. El análisis estadístico mostró, a través de la correlación de Pearson, que el azucar cristal no influenció el proceso de cicatrización de incisiones quirúrgicas infectadas de individuos desnutridos, obesos y con edad evanzada.This is an experimental research based on microbiological analysis. Our aim was to evaluate the influence of sugar on the healing process of infected surgical wounds in 25 patients. On the dehiscences, there have been identified gram positive and gram negative bacteria, and fungi as well. Every patient was administered systemic antibiotics and had the wounds treated locally with cristal sugar three times a day. Statistics showed, by Person's correlation, that sugar did not influence on the

  17. Charmonium production in proton-proton collisions and in collisions of lead nuclei at CERN and comparison with Brookhaven data

    International Nuclear Information System (INIS)

    Topilskaya, N. S.

    2013-01-01

    A review of experimental data on charmoniumproduction that were obtained in fixed-target experiments at the SPS synchrotron and in proton-proton collisions and in collisions of lead nuclei in beams of the Large Hadron Collider (LHC) at CERN (Switzerland) is presented. A comparison with data obtained at the Brookhaven National Laboratory (USA) from experiments at the Relativistic Heavy Ion Collider (RHIC) is performed. Measurement of the suppression of J/ψ-meson production as a possible signal of the production of quark-gluon plasmawas proposed back in 1986 by T. Matsui and H. Satz. An anomalous suppression of J/ψ-meson production was discovered by the NA50 Collaboration at SPS (CERN) in central collisions of lead nuclei at the c.m. collision energy of 158 GeV per nucleon. Data obtained at the c.m. energy of 200 GeV per nucleon in the PHENIX experiment at RHIC indicate that, depending on multiplicity, the suppression of J/ψ-meson production at this energy approximately corresponds to the suppression of J/ψ-meson production in collisions of lead nuclei at the SPS accelerator. Theoretical models that take into account the regeneration of J/ψ mesons describe better RHIC experimental data. The measurement of charmonium production in proton-proton collisions and in collisions of lead nuclei in LHC beams revealed the importance of taking into account the regeneration process. At the LHC energies, it is also necessary to take into account the contribution of B-meson decays. Future measurements of charmonium production at the LHC to a higher statistical precision and over an extended energy region would be of importance for obtaining deeper insight into the mechanism of charmonium production and for studying the properties of matter at high energy density and temperature

  18. Comparison of economic activity leading U.S. sports leagues

    Directory of Open Access Journals (Sweden)

    E.A. Strikalenko

    2013-03-01

    Full Text Available The main activities of the leading sports leagues were described. Sources of revenue and expenditure were identified. The economic performance of professional sports leagues of the United States of America was compared. In the course of the study of economic efficiency of the leading American sports leagues are defined payroll (expense commands on the salaries of players for each team, the total payroll in the League and the average payroll, respectively, for each of the American League. The largest estimates on wages, both in the League and in teams - in the National football League, the largest player's contract - in the Highest League baseball, the minimum wage in the National hockey League; the highest average wages, a greater percentage of athletes with a salary of more than 1 million. $ (82,85 % in the National basketball Association were showed. This difference in the maximum income of the League and of average wages is due to several factors: the number of players in the team, the number of games in a season, and expenses on carrying out of competition and training activities.

  19. Criticality benchmark comparisons leading to cross-section upgrades

    International Nuclear Information System (INIS)

    Alesso, H.P.; Annese, C.E.; Heinrichs, D.P.; Lloyd, W.R.; Lent, E.M.

    1993-01-01

    For several years criticality benchmark calculations with COG. COG is a point-wise Monte Carlo code developed at Lawrence Livermore National Laboratory (LLNL). It solves the Boltzmann equation for the transport of neutrons and photons. The principle consideration in developing COG was that the resulting calculation would be as accurate as the point-wise cross-sectional data, since no physics computational approximations were used. The objective of this paper is to report on COG results for criticality benchmark experiments in concert with MCNP comparisons which are resulting in corrections an upgrades to the point-wise ENDL cross-section data libraries. Benchmarking discrepancies reported here indicated difficulties in the Evaluated Nuclear Data Livermore (ENDL) cross-sections for U-238 at thermal neutron energy levels. This led to a re-evaluation and selection of the appropriate cross-section values from several cross-section sets available (ENDL, ENDF/B-V). Further cross-section upgrades anticipated

  20. Experimental comparison of gamma attenuations by glasses, lead, iron and concretes

    International Nuclear Information System (INIS)

    Charamathieu, Andre; Papot, Lucien

    1964-08-01

    The authors report the experimental determination, for lead glasses of density 3.3, 4.2, 5.2 and 6.2, of thicknesses equivalent to thicknesses given for lead, iron, ordinary concrete and barite concrete for Cobalt 60 and Caesium 137 radiations. Results are presented under the form of curves. Attenuation measurements made on this opportunity and those made on various hot cells have been compared with theoretical attenuation curves produced in another CEA document [fr

  1. Misled about lead: an assessment of online public health education material from Australia's lead mining and smelting towns.

    Science.gov (United States)

    Sullivan, Marianne; Green, Donna

    2016-01-06

    This study assesses the accuracy and comprehensiveness of online public health education materials from the three Australian cities with active lead mines and or smelters: Broken Hill, Mount Isa and Port Pirie. Qualitative content analysis of online Australian material with comparison to international best practice where possible. All materials provided incomplete information about the health effects of lead and pathways of exposure compared to best practice materials. Inconsistent strategies to reduce exposure to lead were identified among the Australian cities, and some evidence-based best practices were not included. The materials normalised environmental lead and neglected to identify that there is no safe level of lead, or that primary prevention is the best strategy for protecting children's health. Health education materials need to clearly state health risks from lead across developmental stages and for sensitive populations, integrate a primary prevention perspective, and provide comprehensive evidence-based recommendations for reducing lead exposure in and around the home. Families who rely on information provided by these online public education materials are likely to be inadequately informed about the importance of protecting their children from exposure to lead and strategies for doing so.

  2. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK

    International Nuclear Information System (INIS)

    Rothwell, James J.; Evans, Martin G.; Lindsay, John B.; Allott, Timothy E.H.

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably. - Multiple peat cores are required for accurate peatland Pb inventories

  3. A comparison of the diminution rates of lead in blood and lead mobilized by CaEDTA after termination of occupational exposure: a long-term observation in two lead workers.

    Science.gov (United States)

    Araki, S; Murata, K; Aono, H; Yanagihara, S; Ushio, K

    1983-07-01

    CaEDTA 20 mg/kg was administered weekly for 3.5 years after termination of occupational exposure to two lead workers. The diminution half-lives for lead in blood and urine lead mobilized by CaEDTA were 4.8 and 3.3 years respectively for subject 1 following 28 years exposure and 3.3 and 2.0 years respectively for subject 2 following 26 years exposure. The difference in the diminution rate between lead in blood and lead mobilized by CaEDTA was significant in subject 2 (p less than 0.05).

  4. Basic principles of lead and lead-bismuth eutectic application in blanket of fusion reactors

    International Nuclear Information System (INIS)

    Beznosov, A.V.; Pinaev, S.S.; Muraviev, E.V.; Romanov, P.V.

    2005-01-01

    High magnetohydrodynamic pressure drop is an important issue for liquid metal blanket concepts. To decrease magnetohydrodynamic resistance authors propose to form insulating coatings on internal surface of blanket ducts at any moment of fusion reactor exploitation. It may be achieved easily if lead or lead-bismuth eutectic is used and technology of oxidative potential handling is applied. A number of experiments carried out in NNSTU show the availability of the proposed technology. It bases on formation of the insulating coatings that consist of the oxides of components of the structural materials and of the coolant components. In-situ value of the insulating coatings characteristics ρδ is ∼ 10 -5 Ohm·m 2 for steels and 5,0x10 -6 - 5,0x10 -5 Ohm·m 2 for vanadium alloys. Thermal cycling is possible during exploitation of a blanket. The experimental research of the insulating coatings properties during thermal cycling have shown that the coatings formed into the lead and lead-bismuth coolants save there insulating properties. Experience of many years is an undoubted advantage of the lead-bismuth coolant and less of the lead coolant in comparison with lithium. Russian Federation possesses of experience of exploitation of the research and industrial facilities, of experience of creation of the pumps, steamgenerators and equipment with heavy liquid metal coolants. The unique experience of designing, assembling and exploitation of the fission reactors with lead-bismuth coolant is also available. The problem of technology of lead and lead-bismuth coolants for power high temperature radioactive facilities has been solved. Accidents, emergency situations such as leakage of steamgenerators or depressurization of gas system in facilities with lead and lead-bismuth coolants have been explored and suppressed. (author)

  5. Comparison of lead residues among avian bones

    International Nuclear Information System (INIS)

    Ethier, A.L.M.; Braune, B.M.; Scheuhammer, A.M.; Bond, D.E.

    2007-01-01

    To determine if significant differences exist in lead (Pb) accumulation in different bones, especially those most often used for bone-Pb studies in wildlife, we compared Pb concentrations in radius, ulna, humerus, femur, and tibia of Common Eider (Somateria mollissima); and radius/ulna (combined), femur, and tibia of American Woodcock (Scolopax minor). There were no significant differences in bone-Pb concentrations among woodcock bones over a wide range of Pb concentrations (3-311 μg/g). In eider, where bone-Pb concentrations were low (<10 μg/g), leg bones had significantly higher Pb concentrations (approximately 30-40%) than wing bones from the same individuals. The variation among individual birds was greater than the variation among different bones within a bird. Based on our findings, we conclude that one type of bone may be substituted for another in bone-Pb studies although the same bone type should be analyzed for all birds within a study, whenever possible. - Variability in Pb concentrations among avian bones

  6. Effects of cadmium on chick embryogenesis and some comparisons with lead

    Energy Technology Data Exchange (ETDEWEB)

    King, D W; Chen, D C.C.; Hsu, J L

    1978-07-01

    During the last ten years because of the severity of the problem of pollution and the part that heavy metals play in it we have been doing research on the effects of some heavy metals on chick embryogenesis in order to get a comparative study and to elucidate their mechanisms of action. Experiments were performed using 431 fertilized white Leghorn eggs to study the effect of cadmium on chick embryogenesis. Cadmium acetate at 0.015, 0.030, 0.045, 0.060, 0.12 or 0.24 mg/egg and lead acetate at 0.02, 0.04 or 0.075 mg/egg was injected in ovo on the fourth day of incubation. The embryos were taken out on the 19th day and examined for gross defects. Electrocardiograms were recorded on some embryos. Hemoglobin determinations were done on others. The changes in plasma delta-aminolevulinic acid dehydrase (ALAD) of the embryos due to cadmium and lead acetate were also determined. It was found that the LD50 of cadmium acetate was close to 0.045 mg. The highest incidence of abnormality, 30.9% of the surviving embryos, appeared in the 0.030 mg group although malformed embryos were also found in the 0.015, 0.045 and 0.060 mg groups. The most common malformations occurred in the liver (58%) and the cardiovascular system, with edema totalling over 90%. Lesser abnormalities were observed in the limbs. Lead acetate affected ALAD more than cadmium acetate. There was no significant difference on hemoglobin concentration or EKG between the distilled water control and either the cadmium or lead treated groups. Thus, embryolethality, embryotoxicity, congenital abnormalities and changes in ALAD were all observed in the cadmium-treated chick embryos although lead acetate seemed to inhibit the ALAD activity more effectively than cadmium acetate.

  7. Effects of lead on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Fiussello, N.; Molinari, M.T.

    1973-01-01

    The poisonousness of lead nitrate to seedlings of several plant species has been tested in Petri dishes, with 10/sup -1/, 10/sup -2/, 10/sup -3/, 10/sup -4/ M conc. Distilled water and KNO/sub 3/ solutions 2 X 10/sup -1/, 2 X 10/sup -2/, 2 X 10/sup -3/, 2 X 10/sup -4/ M were employed as controls. The tested species show a decreasing sensitivity: Capsicum annum > Beta vulgaris > Phalaris canariensis > Vicia sativa > Helianthus annuus > Oryza sativa > Triticum vulgare Avena sativa > Pisum sativum. Avena sativa shows a diminution of 34% in ww, 23% in dw, 26% in chlorophyll content in comparison with the controls after 21 days 10/sup -4/ M lead nitrate. The chlorophyll content, referred to dry weight, is related to lead concentration. Since the early stages of chlorophyll biosynthesis are similar, if not identical, with those for Haemoglobin, lead could interfere as it does in haemoglobin synthesis.

  8. A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler.

    Science.gov (United States)

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Andrew, Michael E

    2006-03-01

    Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass

  9. Impacts of aerosol lead to natural ecosystems

    International Nuclear Information System (INIS)

    Murozumi, Masayo; Nakamura, Seiji; Yoshida, Katsumi

    1982-01-01

    Impacts of aerosol lead have changed the concentration and isotopic ratios of the element circulating in remote ecosystems in the Hidaka and Tarumae mountains. Concentrations of lead in successive each 10 years ring veneer of Cercidiphyllum Japonica show that amount of the element residing on the bark and supwood layers has increased by a factor of 2 or more in comparison with that of the core part. The isotopic ratios of lead in the basement rocks and soils under the ecosystems converge to a certain narrow spot along the isochron Iine of the element, and distinguish their geochronogical characteristics from other leads of different sources. In these ecosystems, however, the lead isotopic ratios of materials exposed to the atmosphere are similar to those of foreign and anthropogenic aerosol lead but are evidently dissimilar to those of the rocks and soils. Furthermore, the lead isotopic ratios in yearly ring veneers of Ceridiphyllum Japonica and Ostrya Japonica show a certain differentiation towards the bark from the core, i.e., an approach to those of anthropogenic aerosol lead from those of the basement rocks and soils, as listed in Table 7. The lead burden per hectare in these remote ecosystems has increased to 4 g by the impact of 2 g of aerosol lead. (author)

  10. Are lead-free hunting rifle bullets as effective at killing wildlife as conventional lead bullets? A comparison based on wound size and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Trinogga, Anna, E-mail: anna_trinogga@gmx.de; Fritsch, Guido; Hofer, Heribert; Krone, Oliver

    2013-01-15

    Fragmentation of the lead core of conventional wildlife hunting rifle bullets causes contamination of the target with lead. The community of scavenger species which feed on carcasses or viscera discarded by hunters are regularly exposed to these lead fragments and may die by acute or chronic lead intoxication, as demonstrated for numerous species such as white-tailed eagles (Haliaeetus albicilla) where it is among the most important sources of mortality. Not only does hunting with conventional ammunition deposit lead in considerable quantities in the environment, it also significantly delays or threatens the recovery of endangered raptor populations. Although lead-free bullets might be considered a suitable alternative that addresses the source of these problems, serious reservations have been expressed as to their ability to quickly and effectively kill a hunted animal. To assess the suitability of lead-free projectiles for hunting practice, the wounding potential of conventional bullets was compared with lead-free bullets under real life hunting conditions. Wound dimensions were regarded as good markers of the projectiles' killing potential. Wound channels in 34 killed wild ungulates were evaluated using computed tomography and post-mortem macroscopical examination. Wound diameters caused by conventional bullets did not differ significantly to those created by lead-free bullets. Similarly, the size of the maximum cross-sectional area of the wound was similar for both bullet types. Injury patterns suggested that all animals died by exsanguination. This study demonstrates that lead-free bullets are equal to conventional hunting bullets in terms of killing effectiveness and thus equally meet the welfare requirements of killing wildlife as painlessly as possible. The widespread introduction and use of lead-free bullets should be encouraged as it prevents environmental contamination with a seriously toxic pollutant and contributes to the conservation of a wide

  11. Are lead-free hunting rifle bullets as effective at killing wildlife as conventional lead bullets? A comparison based on wound size and morphology

    International Nuclear Information System (INIS)

    Trinogga, Anna; Fritsch, Guido; Hofer, Heribert; Krone, Oliver

    2013-01-01

    Fragmentation of the lead core of conventional wildlife hunting rifle bullets causes contamination of the target with lead. The community of scavenger species which feed on carcasses or viscera discarded by hunters are regularly exposed to these lead fragments and may die by acute or chronic lead intoxication, as demonstrated for numerous species such as white-tailed eagles (Haliaeetus albicilla) where it is among the most important sources of mortality. Not only does hunting with conventional ammunition deposit lead in considerable quantities in the environment, it also significantly delays or threatens the recovery of endangered raptor populations. Although lead-free bullets might be considered a suitable alternative that addresses the source of these problems, serious reservations have been expressed as to their ability to quickly and effectively kill a hunted animal. To assess the suitability of lead-free projectiles for hunting practice, the wounding potential of conventional bullets was compared with lead-free bullets under real life hunting conditions. Wound dimensions were regarded as good markers of the projectiles' killing potential. Wound channels in 34 killed wild ungulates were evaluated using computed tomography and post-mortem macroscopical examination. Wound diameters caused by conventional bullets did not differ significantly to those created by lead-free bullets. Similarly, the size of the maximum cross-sectional area of the wound was similar for both bullet types. Injury patterns suggested that all animals died by exsanguination. This study demonstrates that lead-free bullets are equal to conventional hunting bullets in terms of killing effectiveness and thus equally meet the welfare requirements of killing wildlife as painlessly as possible. The widespread introduction and use of lead-free bullets should be encouraged as it prevents environmental contamination with a seriously toxic pollutant and contributes to the conservation of a wide variety

  12. Progress on the Femto-Slicing Project at the Synchrotron SOLEIL

    International Nuclear Information System (INIS)

    Prigent, P; Hollander, Ph; Labat, M; Couprie, M E; Marlats, J L; Laulhé, C; Luning, J; Moreno, T; Morin, P; Nadji, A; Polack, F; Ravy, S; Silly, M; Sirotti, F

    2013-01-01

    The aim of the Femto-Slicing project at SOLEIL is to generate 100 fs X-rays pulses on two beamlines, CRISTAL and TEMPO, for pump-probe experiments in the hard and soft X-rays regions. Two fs lasers are currently in operation on TEMPO and CRISTAL for pump-probe experiments on the ps time scale enabling time resolved photoemission and photodiffraction studies. The Femto-Slicing project is based on the fs laser of the CRISTAL beamline, which can be adjusted to deliver 3 mJ pulses of 30 fs duration at 2.5 kHz. The laser beam will be separated in three branches: one delivering about 2 mJ to the modulator Wiggler and the other ones delivering the remaining energy to the TEMPO and CRISTAL experiments. This layout will yield natural synchronization between IR laser pump and X-ray probe pulses, only affected by jitter associated with beam transport. In this paper, we present the current status of the Femto-Slicing project at SOLEIL, with particular emphasis on the expected performance, and the design and construction of the laser beam transport and the diagnostics implementation.

  13. High-Temperature Lead-Free Solder Alternatives: Possibilities and Properties

    DEFF Research Database (Denmark)

    High-temperature solders have been widely used as joining materials to provide stable interconnections that resist a severe thermal environment and also to facilitate the drive for miniaturization. High-lead containing solders have been commonly used as high-temperature solders. The development...... of high-temperature lead-free solders has become an important issue for both the electronics and automobile industries because of the health and environmental concerns associated with lead usage. Unfortunately, limited choices are available as high-temperature lead-free solders. This work outlines...... the criteria for the evaluation of a new high-temperature lead-free solder material. A list of potential ternary high-temperature lead-free solder alternatives based on the Au-Sn and Au-Ge systems is proposed. Furthermore, a comprehensive comparison of the high-temperature stability of microstructures...

  14. Clinical performance of different DF-4 implantable cardioverter defibrillator leads.

    Science.gov (United States)

    Sarrazin, Jean-François; Philippon, François; Sellier, Romain; André, Philippe; O'Hara, Gilles; Molin, Franck; Nault, Isabelle; Blier, Louis; Champagne, Jean

    2018-06-01

    Implantable cardioverter-defibrillator (ICD) DF-4 connectors have been introduced to facilitate defibrillator lead connection and to reduce the size of device header. There are limited data regarding the overall performance of those leads and no comparison between different ICD DF-4 leads. This is a cohort study of consecutive patients implanted with ICD DF-4 lead system at one University Centre between October 2010 and February 2015. A historical control group of patients with ICD DF-1 lead implantation was used for comparison. The following ICD DF-4 leads were evaluated: St. Jude Medical Durata 7122Q (St. Jude Medical, St. Paul, MN, USA), Medtronic Sprint Quattro Secure 6935 M (Medtronic Inc., Minneapolis, MN, USA), Boston Scientific Endotak Reliance 4-Site 0293 (Boston Scientific, Marlborough, MA, USA), and Boston Scientific Reliance 4-Front 0693. This study evaluated the acute and mid-term performances of those leads as well as complications. A total of 812 patients (age 63 ± 12 years, 80% male, left ventricular ejection fraction 31 ± 12%) underwent implantation of an ICD DF-4 lead. Acute and follow-up R-wave sensing and threshold were excellent. Compared to implantation, intrinsic R waves were higher at follow-up for Boston Scientific and Medtronic leads, and pacing lead impedances were lower for all leads at first follow-up (P < 0.001). The number of lead dislodgement or failure was similar between all leads. The estimated lead survival rates at 3 years were 95.6% for Boston Scientific Endotak 4-Site, 97.1% for Boston Scientific 4-Front, 97.7% for Medtronic Sprint Quattro, and 97.5% for St. Jude Durata (P  =  0.553). All ICD DF-4 leads had excellent acute and mid-term electrical performances. Longer follow-up will be necessary to confirm their sustained performance. © 2018 Wiley Periodicals, Inc.

  15. Recent Methods in Crystal Spectrometry; Methodes Recentes de Spectrometrie a Cristal; 041d 041e 0412 042b 0415 041c 0415 0422 041e 0414 042b 041a 0420 0418 0421 0422 0410 041b 041b 0418 0427 0415 0421 041a 041e 0419 0421 041f 0415 041a 0422 0420 041e 041c 0415 0422 0420 0418 0418 ; Metodos Recientes de Espectrometria Cristalina

    Energy Technology Data Exchange (ETDEWEB)

    Iyengar, P. K. [Atomic Energy Establishment Trombay, Bombay (India)

    1965-06-15

    measurements of energy distribution is illustrated. A further advantage in the study of single crystal samples comes from the possibility-of operating all the arms with the analysing spectrometers in the constant-Q mode. This would, in future, greatly increase the rate of data collection using the crystal spectrometer technique. (author) [French] Le principe de la diffraction dans les cristaux fournit un moyen, simple de mesurer la distribution des neutrons lents selon l'energie. Toutefois, la determination quantitative de cette distribution depend de parametres differents selon la structure de la cellule elementaire du cristal monochromateur et la disposition geometrique du spectrometre. Le spectrometre triaxial a ete beaucoup utilise dans des travaux sur la diffusion inelastique.. Il comporte un cristal monochromateur et un analyseur a cristal. La disposition geometrique et la dispersion due a la variation non lineaire de l'angle en fonction de la longueur d'onde entrainent des effets de focalisation. L'auteur examine cet aspect du probleme pour divers cas, tels que la diffraction elastique et les groupes de neutrons dus a des interactions a un phonon. L'auteur a utilise comme analyseur un ensemble comprenant un filtre polycristallin et un detecteur, ce qui permet de realiser un gain en intensite dans les mesures de diffusion inelastique. Une des difficultes que presente l'emploi de cet ensemble avec des echantillons a diffusion coherente reside dans l'incertitude relative au transfert de la quantite de mouvement. On a utilise recemment, pour l'etude de la diffusion inelastique, une combinaison de deux filtres de caracteristiques differentes, et un compteur destine a detecter les neutrons retrodiffusis a partir du deuxieme filtre formant fenetre. Ils en resulte un meilleur pouvoir de resolution en energie et une meilleure definition du transfert de la quantite de mouvement. L'auteur presente certaines mesures qui portent sur les caracteristiques de ce type de filtre. Tirant

  16. Community blood lead survey with emphasis on preschool children following lead dust pollution in Esperance, Western Australia.

    Science.gov (United States)

    Rossi, Enrico; McLaughlin, Virginia; Joseph, John; Bulsara, Max; Coleman, Kerryn; Douglas, Charles; Robertson, Andrew

    2012-04-01

    To assess the impact of airborne lead dust on blood lead levels in residents of Esperance, a regional Western Australian town, with particular reference to preschool children. Following identification of significant airborne lead contamination, residents were notified that a blood lead clinic was available to all, with testing of preschool children encouraged. About 40% (333 children) of the preschool group and about 20% of the remaining population were tested. The main measures were blood lead levels, prevalence of elevated results and comparisons to other Western Australian surveys. In preschoolers, 2.1% (seven children) had blood lead levels exceeding the current 10 μg/dL level of concern. This was not significantly different to two previous community-based surveys elsewhere in Western Australia. However, at a lower cut-off of 5 μg/dL, the prevalence of elevated lead levels was 24.6%, significantly higher than children tested in a previous Western Australian survey. The prevalence of blood lead levels of 10 μg/dL or greater in adults was 1.3% (26 adults), not significantly different from a previous Western Australian survey. The prevalence of preschool children with blood lead levels exceeding the current level of concern was not significantly increased. However, the increased prevalence of children with lead levels at or above 5 μg/dL demonstrates exposure to lead dust pollution. This episode of lead dust contamination highlights the need for strict adherence to environmental controls and effective monitoring processes to ensure the prevention of future events. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

  17. Leading multi-soft limits from scattering equations

    Science.gov (United States)

    Zlotnikov, Michael

    2017-10-01

    A Cachazo-He-Yuan (CHY) type formula is derived for the leading gluon, bi-adjoint scalar ϕ 3, Yang-Mills-scalar and non-linear sigma model m-soft factors S m in arbitrary dimension. The general formula is used to evaluate explicit examples for up to three soft legs analytically and up to four soft legs numerically via comparison with amplitude ratios under soft kinematics. A structural pattern for gluon m-soft factor is inferred and a simpler formula for its calculation is conjectured. In four dimensions, a Cachazo-Svrček-Witten (CSW) recursive procedure producing the leading m-soft gluon factor in spinor helicity formalism is developed as an alternative, and Britto-Cachazo-Feng-Witten (BCFW) recursion is used to obtain the leading four-soft gluon factor for all analytically distinct helicity configurations.

  18. 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

  19. 90 deg.Neutron emission from high energy protons and lead ions on a thin lead target

    CERN Document Server

    Agosteo, S; Foglio-Para, A; Mitaroff, W A; Silari, Marco; Ulrici, L

    2002-01-01

    The neutron emission from a relatively thin lead target bombarded by beams of high energy protons/pions and lead ions was measured at CERN in one of the secondary beam lines of the Super Proton Synchrotron for radiation protection and shielding calculations. Measurements were performed with three different beams: sup 2 sup 0 sup 8 Pb sup 8 sup 2 sup + lead ions at 40 GeV/c per nucleon and 158 GeV/c per nucleon, and 40 GeV/c mixed protons/pions. The neutron yield and spectral fluence per incident ion on target were measured at 90 deg.with respect to beam direction. Monte-Carlo simulations with the FLUKA code were performed for the case of protons and pions and the results found in good agreement with the experimental data. A comparison between simulations and experiment for protons, pions and lead ions have shown that--for such high energy heavy ion beams--a reasonable estimate can be carried out by scaling the result of a Monte-Carlo calculation for protons by the projectile mass number to the power of 0.80-0...

  20. Lead evaluation in blood of workers of batteries industries

    International Nuclear Information System (INIS)

    Valbuena P, John J; Duarte, Martha; Marciales Clara

    2001-01-01

    In order to evaluate the occupational risk of exposure to lead of employees working in three small industries that recycle and manufacture acid lead batteries, the lead and zinc protoporphyrine (ZPP) blood content was determined. The determination was also performed on people not exposed in order to establish comparison values. Venous blood was collected in metal free heparinized glass tubes. Lead was analyzed by atomic absorption with graphite furnace and ZPP by fluorescence. According to Colombian legislation, it was found that around 31 % workers in this type of industries are in dangerous and intoxication exposure. It was also found that 91 % of workers exceed the level of 30 mg Pb/dL blood established as standard by the American Conference governmental Industrial Hygienists (ACGIH)

  1. Next-To-Leading Order Determination of Fragmentation Functions

    CERN Document Server

    Bourhis, L; Guillet, J P; Werlen, M

    2001-01-01

    We analyse LEP and PETRA data on single inclusive charged hadron cross-sections to establish new sets of Next-to-Leading order Fragmentation Functions. Data on hadro-production of large-$p_{\\bot}$ hadrons are also used to constrain the gluon Fragmentation Function. We carry out a critical comparison with other NLO parametrizations.

  2. 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.

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

    International Nuclear Information System (INIS)

    2002-06-01

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

  4. Comparison of serum lead level in oral opium addicts with healthy control group.

    Science.gov (United States)

    Salehi, Hossein; Sayadi, Ahmad Reza; Tashakori, Mahnaz; Yazdandoost, Rokhsareh; Soltanpoor, Narges; Sadeghi, Hossein; Aghaee-Afshar, Mahmood

    2009-11-01

    Drug abuse and its consequences are major health problems in Middle-East countries such as Iran. Salesmen and smugglers may add lead to opium during the process of opium preparation to increase the weight of opium for more profit. Several reports have found lead poisoning symptoms in opium addicted patients and there are many nonspecific symptoms mimicking lead poisoning in opium addicted patients. As far as the literature review is concerned, there is no comparative study about blood lead level (BLL) in addicted patients with healthy controls. Therefore, it seems evaluation of blood lead level in opium addicted patients to be important. In this study, the BLL of forty-four subjects in two patient and control groups was evaluated. The patient group (22 subjects) was comprised of patients who used oral opium. Control group (22 subjects) was matched with the patient group for age and sex, considering inclusion and exclusion criteria with a mean age of 38.8+/-6.7. For blood lead assay, 3 mL of whole blood was obtained from both groups by venipuncture and BLL was assessed immediately using an atomic absorption spectrophotometer. The BLL in patient group had a range of 7.2 to 69.9 g/dL with a mean of 21.9+/-13.2. In the healthy control group, BLL was between 4.1 to 17.4 g/dL with a mean of 8.6+/-3.5. The mean difference of both groups (t=4.56) was statistically significant (Popium ingested (r=0.65, Popium ingestion in the patient group. It would be concluded that opium addicts have an elevated BLL compared to healthy controls. Therefore, screening of blood lead concentration is helpful for opium addicted people especially with non-specific symptoms. In this regard, a similar investigation with a larger sample size of opium addicted patients (including both oral and inhaled) and a control group is suggested to confirm the findings of this research.

  5. Lead contents in blood samples of a children population of Mexico City related to levels of airborne lead determined by PIXE

    International Nuclear Information System (INIS)

    Uribe-Hernandez, R.; Perez-Zapata, A.J.; Flores M., J.; Aldape, F.; Hernandez-Mendez, B.

    1996-01-01

    Airborne lead has been considered for many years one of the main pollutants adversely affecting the health of human beings. Moreover, this problem becomes remarkably important in large urban areas such as Mexico City. In order to assess the influence of atmospheric airborne lead in a children population, a biological blood sampling was carried out from September 1992 to June 1993 taking 698 samples in children with ages ranging from a few weeks to thirteen years old. Lead contents in whole blood were determined using anode stripping voltammetry as analytical technique. At the same time, aerosol lead contents were determined by PIXE from samples taken twice a week (two samples per day) in a neighbour area. In 58% of the samples, lead contents in blood was found over the maximum permissible level established by the Center for Disease Control (CDC) of the U.S.A. The biological sampling was correlated to levels of airborne lead as well as children age and date of sampling. General results of these comparisons are presented. (author)

  6. 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.

  7. Application of a Complex Lead Compensator for a Laser Guided Missile

    Science.gov (United States)

    Akhila, M. R.; Gopika, S.; Abraham, R. J.

    2013-01-01

    This paper discusses the application of a lead compensator with complex pole and complex zero for a missile. It is compared with a lead compensator with real pole and real zero. A typical laser guided missile control system is considered for the performance comparison of both the compensators. Simulation studies carried out with MATLAB brings out the scope of using complex compensator in missile guided systems.

  8. Effect of lead acetate on learning and memory in rats

    Energy Technology Data Exchange (ETDEWEB)

    Seki, H; Maeda, H; Ohi, G; Yagyu, H

    1974-01-01

    To study the mental effects of exposure to lead, especially in auto exhaust in the ambient air, adult female Wistar rats were orally dosed with lead acetate at 125 mg(Pb)/30 g food for 6 weeks from the 3rd day of pregnancy to the 3rd week after delivery. Nine week-old male rats were examined as to learning and memory ability using a labyrinth in comparison to the ability of control rats. No significant deterioration of these abilities which might have been caused by exposure to lead in the rats early life stage was noted, although the mothers were given the maximal dose of lead they and the fetuses could tolerate.

  9. RETRACTED ARTICLE: Happiness as alchemy: Positive mood leads to self-serving responses to social comparisons

    OpenAIRE

    Johnson, Camille S.; Stapel, Diederik A.

    2011-01-01

    People in a positive mood process information in ways that reinforce and maintain this positive mood. The current studies examine how positive mood influences responses to social comparisons and demonstrates that people in a positive mood interpret ambiguous information about comparison others in self-benefitting ways. Specifically, four experiments demonstrate that compared to negative mood or neutral mood participants, participants in a positive mood engage in effortful re-interpretations o...

  10. Study of stripping cristallization processus of AUC with ammonium carbonate

    International Nuclear Information System (INIS)

    Chegrouche, Salah.

    1987-09-01

    This study is concerned with direct crystallization of ammonium uranyl carbonate (AUC) from a uranium loaded organic phase (30% TBP in kerosene), with ammonium carbonate (NH 4 ) 2 CO 3 . The effects of operating conditions ((NH 4 ) 2 CO 3 concentration, flow-ratio, residence time, temperature) on the physical properties of AUC crystals (particle size distribution, specific surface, density...) are reported. All products were identified (both by chemical analysis, X-Ray diffraction) as being ammonium uranyl carbonate crystals (AUC). The results show that a high phase ratio and (NH 4 ) 2 CO 3 concentration favor the formation of fine AUC grains and aggregates. This is due mainly to the high concentration of NH + 4 in the system which leads to a high solution supersaturation and consequently to a rapid formation rate of crystal (germination). The reverse phenomenon is observed at low phase ratio and (NH 4 ) 2 CO 3 concentration, where germination and crystal growth are slow and the product is mainly monocrystal. In the intermediate range, a mixture of polycrystal and aggregates is obtained. Residence and temperature are also shown to have an effect on the processes (the effect of time being more important than temperature). In the course of this study a bench-scale stripper-crystallizer was developped and operated successfully. (author). tables, graphs

  11. Physical study of the 'snow flake' version of the reactor EL-3 (1963); Etude physique de la version ''cristal de neige'' de la pile EL-3 (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Abillon, E; Genthon, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    A systematic study has been made of the different thermodynamic and neutronic aspects of various versions of the 'snow flake' likely to fulfil the aims which were set out (improvement of the reactivity, of the experimental volume, improvement in the working conditions of EL-3). After this systematic study, a choice was made in principle of one version amongst the several available (solutions using 8 or 10 pencils-various methods of heat transfer: corrugation, cartridges which may or may not be filled with helium... etc., variable enrichments... ). The choice is that of a version which can already at the present be considered as feasible, which represents already a notable improvement of the pile and which does not imply the existence of a major problem as far as the possible change-over later to an improved version is concerned. This choice defines a fuel element and a configuration for the core. A detailed recapitulation has been made of all the research being carried out for the possible solutions in this particular case. (authors) [French] On a etudie systematiquement les differents aspects thermodynamiques et neutroniques de diverses versions 'cristal de neige' susceptibles de remplir les buts fixes (amelioration en reactivite, en volume experimental, amelioration des problemes d'exploitation de EL-3). Apres cette etude systematique, on a procede au choix de principe d'une version parmi les differentes solutions possibles (solutions a 8 ou 10 crayons - possibilite de transfert de chaleur divers: corrugations, cartouches remplies He ou non.... etc., enrichissements variables... ). Ce choix est celui d'une version qu'on peut juger viable des aujourd'hui, qui represente deja une amelioration importante de la pile et qui n'implique pas de probleme majeur quant au passage ulterieur et eventuel a une version plus amelioree. Ce choix definit un element combustible, et une configuration de coeur. On a recapitule et detaille sur ce cas particulier de pile les etudes

  12. Asymmetric electrooptic response in a nematic liquid crystal

    Energy Technology Data Exchange (ETDEWEB)

    Dascalu, Constanta [Politechnica University of Bucharest, Bucharest (Romania)

    2001-06-01

    An asymmetric electrooptic response in nematic liquid crystal (LC) has been obtained. The liquid crystal hybrid cell was made by using a standard configuration. One of the ITO (Indium Tin Oxide) electrodes was covered with a surfactant, which induces a homeotropic alignment. The second of the indium tin oxide electrodes was covered by a thin layer of photopolymer, which was previously mixed with an acid, which favours a process of release of protons. Such cations are responsible of electrochemical process in the LC leading to an asymmetric electrooptic response, which depend on the polarity of the applied electric field. This fact is due to an internal field, which change the effective voltage thresholds for the reorientation of the liquid crystal. During the anodic polarization, the optical switching is inhibited because the effective field decreases below the threshold value. On contrary for the opposite polarization the effective field is enough to determine a homeotropic alignment. [Spanish] Se ha obtenido una respuesta electro-optica asimetrica en cristales liquidos neumaticos. La celula hibrida de cristal liquido fue construida utilizando una configuracion estandar. Uno de los electrodos ITO fue cubierto con una pelicula delgada de material organico para inducir una alineacion homeotropa. El otro electrodo ITO fue cubierto con una pelicula delgada de fotopolimero anteriormente mezclada con un acido para favorecer la emision de protones. Estos cationes son responsables del proceso electroquimico en LC, conduciendo a una respuesta electro-optica asimetrica que depende de la polaridad del campo electrico aplicado. Este efecto es originado por un campo interno que cambia el umbral efectivo del voltaje para la reorientacion del cristal liquido. Durante la polarizacion anodica, la conmutacion optica se inhibe debido a que el campo efectivo disminuye abajo del valor del umbral. Por el contrario, para la polarizacion opuesta el campo efectivo es suficiente para

  13. 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.

  14. Pacemaker Implantation Associated Myocardial Micro-Damage: A Randomised Comparison between Active and Passive Fixation Leads.

    Science.gov (United States)

    Blažek, Patrick; Ferri-Certić, Jerko; Vražić, Hrvoje; Lennerz, Carsten; Grebmer, Christian; Kaitani, Kazuaki; Karch, Martin; Starčević, Boris; Semmler, Verena; Kolb, Christof

    2018-03-20

    Fixation of the pacemaker leads during pacemaker implantation leads to an increase of cardiac Troponin T (cTnT) that can be interpreted as a sign of minimal myocardial damage. This trial evaluates whether the mechanism type of lead fixation influences the magnitude of cTnT release. Patients having a de-novo cardiac pacemaker implantation or a lead revision were centrally randomized to receive either a ventricular lead with an active (screw) or passive (tine) fixation mechanism. High-sensitive Troponin T (hsTnT) was determined on the day of the procedure beforehand and on the following day. 326 Patients (median age (IQR) 75.0 (69.0-80.0) years, 64% male) from six international centers were randomized to receive ventricular leads with an active (n = 166) or passive (n = 160) fixation mechanism. Median (IQR) hsTnT levels increased by 0.009 (0.004-0.021) ng/ml in the group receiving screw-in ventricular leads and by 0.008 (0.003-0.030) ng/ml in the group receiving tined ventricular leads (n.s.). In conclusion pacemaker implantations are followed by a release of hsTnT. The choice between active or passive fixation ventricular leads does not have a significant influence on the extent of myocardial injury and the magnitude of hsTnT release.

  15. Efecto cristal. Reflexiones sobre arquitectura

    Directory of Open Access Journals (Sweden)

    Dr. Arq. Carlos Pantaleón Panaro

    2017-12-01

    Full Text Available ESPEJISMO es una ilusión óptica debido a la reflexión total de la luz cuando atraviesa capas de aire de densidad distinta, con lo cual los objetos lejanos dan una imagen invertida, como si se reflejaran sobre el agua, tal como ocurre en las llanuras de los desiertos. 1 La definición de espejismo nos explica que es una ilusión, una ficción, un desvarío, un delirio. Algo que no es real ni verdadero, la apariencia engañosa de algo que no existe. ¿Pero no existe, realmente? Tal vez se pueda decir, desde algún punto de vista, que una imagen ilusoria no es real. Pero ¿podríamos afirmarlo desde el punto de vista del fenómeno de la percepción? Si lo vemos, ¿no tendríamos derecho a decir que es real? ¿Algo tiene que ser material y poder tocarse, para ser real? ¿No basta simplemente con verlo? Este artículo de reflexión trata sobre el tema de lo ilusorio, de los espejismos y apariencias engañosas que, no obstante su naturaleza falaz, existen y se perciben, y son procesados por nuestra mente como fenómenos sensoriales que conforman nuestra percepción. El hilo conductor es un viaje a través de diferentes paisajes espejados: el del azar, el de las artes y el de la arquitectura. 1Diccionario de la Real Academia Española

  16. The possibility of using 5-aminolevulinic acid in lead phytoextraction process

    Directory of Open Access Journals (Sweden)

    Zbigniew Jarosz

    2013-04-01

    Full Text Available Studies conducted in the greenhouse involving a sunflower (Helianthus annuus L. grown in medium containing 200 mg Pb ∙ dm -3 which were designed to evaluate the impact of foliar nutrition with 5-aminolevulinic acid (5-ALA on the chemical composition of sunflower in reference to possible use of this plant in the process of induced phytoextraction. The study revealed from 4.8% to 34.1% increase in aboveground matter of sunflower which was sprayed by 5-ALA solution at concentrations of 0.01-0.1 ppm in comparison with plants grown in a medium containing 200 mg Pb ∙ dm -3 with no 5-ALA spraying. The sunflower leaves sprayed by 5-ALA solution contained from 3.78% to 27.1% more lead in comparison to plants not sprayed by this agent. As well as remarkable decrease in lead content from 17.4 to 33.4% was recorded in the roots of sunflower sprayed by 5-ALA solution. The lead content in plant shoots was independent from foliar application of 5-aminolevulinic acid

  17. 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

  18. Measuring leading placental edge to internal cervical os: Transabdominal versus transvaginal approach

    DEFF Research Database (Denmark)

    Westerway, Susan Campbell; Hyett, Jon; Henning Pedersen, Lars

    2017-01-01

    We aimed to compare the value of transabdominal (TA) and transvaginal (TV) approaches for assessing the risk of a low-lying placenta. This involved a comparison of TA and TV measurements between the leading placental edge and the internal cervical os. We also assessed the intra-/interobserver var......We aimed to compare the value of transabdominal (TA) and transvaginal (TV) approaches for assessing the risk of a low-lying placenta. This involved a comparison of TA and TV measurements between the leading placental edge and the internal cervical os. We also assessed the intra......-/interobserver variation for these measurements and the efficacy of TA measures in screening for a low placenta. Methodology Transabdominal and TV measurements of the leading placental edge to the internal cervical os were performed on 369 consecutive pregnancies of 16–41 weeks' gestation. The difference (TA-TV) from...... the area under the receiver operator characteristics (ROC) curve. Intra-/interobserver variations were also calculated. Results Of the pregnancies, 278 had a leading placental edge that was visible with the TV approach. Differences (TA-TV) ranged from −50 mm to +57 mm. Bland-Altman plot shows that TA...

  19. Phase-out of leaded gasoline: a prescription for Lebanon

    International Nuclear Information System (INIS)

    Hashisho, Z.; El-Fadel, M.; Ayoub, G.; Baaj, H.

    2000-01-01

    Full text.Lead is a toxic heavy metal. Nevertheless, it has been mined and used for more than 800 years. Among the different contemporary sources of lead pollution, emissions from the combustion of leaded gasoline is of particular concern, as it can constitutes more than 90 percent of total lead emissions into the atmosphere in congested urban areas. Concentrations of lead in air and blood are strongly correlated with gasoline lead content and traffic volume. As a result of the increasing awareness about the dangers of lead to human health and the measures to manage urban air pollution, the use of leaded gasoline has been decreasing worldwide. In Lebanon, in the absence of policies to reduce the use of lead in gasoline or to favor the use of unleaded gasoline, leaded gasoline is the predominant grade. The objective of this research work is to analyze the current status of gasoline, and to assess the feasibility and prospect of such action. For this purpose, background information are presented, data about gasoline usage and specifications have been collected, field measurements have been performed and a public survey has been conducted. The comparison of the expected cost savings from phasing out leaded gasoline with the potential costs indicates that such action is economically highly justified. If effective regulatory measures are undertaken, leaded gasoline can be phased-out immediately without a significant cost

  20. Comparison between Clinically Used Irregular Fields Shielded by Cerrobend and Standard Lead Blocks

    Directory of Open Access Journals (Sweden)

    Farajollahi A. R.

    2015-06-01

    Full Text Available Introduction: In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. Materials and Methods: All measurements were performed for 60Co γ-ray beams and the Cerrobend blocks were fabricated by commercial Cerrobend materials. Standard lead block shields belonged to Cobalt unit. Data was collected through a calibrated ionization chamber, relative dosimetry systems and a TLD dosimetery. Results: Results of the percent depth dose (PDD measurements at depths of 0.5, 1, 5, 10, 15 and 20 cm for 23 different field sizes of patients with head and neck cancer showed no significant differences between lead and Cerrobend shielding methods. Measurement results of absolute dosimetry in depths of 1.5, 3, 5, 7, 10 and 12 cm also showed no significant differences between these two shielding methods. The same results were obtained by TLD dosimetry on patient skin. Conclusion: Use of melt shielding methods is a very easy and fast shield-making technique with no differences in PDD, absolute and skin dose between lead and Cerrobend block shielding methods.

  1. Lead bioaccessibility in topsoils from lead mineralisation and urban domains, UK

    International Nuclear Information System (INIS)

    Appleton, J.D.; Cave, M.R.; Palumbo-Roe, B.; Wragg, J.

    2013-01-01

    Predictive linear regression (LR) modelling indicates that total Pb is the only highly significant independent variable for estimating Pb bioaccessibility in “mineralisation domains” located in limestone (high pH) and partly peat covered (low pH) shale-sandstone terrains in England. Manganese is a significant minor predictor in the limestone terrain, whilst organic matter and sulphur explain 0.5% and 2% of the variance of bioaccessible Pb in the peat-shale-sandstone terrain, compared with 93% explained by total Pb. Bootstrap resampling shows that LR confidence limits overlap for the two mineralised terrains but the limestone terrain has a significantly lower bioaccessible Pb to total Pb slope than the urban domain. A comparison of the absolute values of stomach and combined stomach-intestine bioaccessibility provides some insight into the geochemical controls on bioaccessibility in the contrasting soil types. -- Highlights: •Total Pb is the only highly significant predictor for bioaccessible Pb in lead mineralisation domains. •Manganese is a significant minor predictor in limestone terrain. •Organic matter and sulphur are minor predictors in peat-shale-sandstone terrain. •Results can be used for initial risk assessment in Pb mineralisation domain. -- Total Pb is the major predictor for bioaccessible Pb in topsoils from two lead mineralised areas in England

  2. Human health risk assessment of lead from mining activities at semi-arid locations in the context of total lead exposure.

    Science.gov (United States)

    Zheng, Jiajia; Huynh, Trang; Gasparon, Massimo; Ng, Jack; Noller, Barry

    2013-12-01

    Lead from historical mining and mineral processing activities may pose potential human health risks if materials with high concentrations of bioavailable lead minerals are released to the environment. Since the Joint Expert Committee on Food Additives of Food and Agriculture Organization/World Health Organization withdrew the Provisional Tolerable Weekly Intake of lead in 2011, an alternative method was required for lead exposure assessment. This study evaluated the potential lead hazard to young children (0-7 years) from a historical mining location at a semi-arid area using the U.S. EPA Integrated Exposure Uptake Biokinetic (IEUBK) Model, with selected site-specific input data. This study assessed lead exposure via the inhalation pathway for children living in a location affected by lead mining activities and with specific reference to semi-arid conditions and made comparison with the ingestion pathway by using the physiologically based extraction test for gastro-intestinal simulation. Sensitivity analysis for major IEUBK input parameters was conducted. Three groups of input parameters were classified according to the results of predicted blood concentrations. The modelled lead absorption attributed to the inhalation route was lower than 2 % (mean ± SE, 0.9 % ± 0.1 %) of all lead intake routes and was demonstrated as a less significant exposure pathway to children's blood, compared with ingestion. Whilst dermal exposure was negligible, diet and ingestion of soil and dust were the dominant parameters in terms of children's blood lead prediction. The exposure assessment identified the changing role of dietary intake when house lead loadings varied. Recommendations were also made to conduct comprehensive site-specific human health risk assessment in future studies of lead exposure under a semi-arid climate.

  3. SUNAN KALIJAGA DALAM NOVEL BABAD WALISONGO, WALI SANGA, DAN KISAH DAKWAH WALI SONGO

    Directory of Open Access Journals (Sweden)

    Erlis Nur Mujiningsih

    2016-11-01

    Full Text Available The issues in this research is  to provide that novels Wali Sanga by Shashangka, Babad Walisongo by Yudhi Aw, and Kisah Dakwah Wali Songo by Kusuma is the cristalization of discourse interaction in walisongo. The scope of this research is to prove that three novels success to provide the cristalization of discourse interaction in the varians fields that narrative walisongo. Method of this research is qualitative method. Resources of data is novels Babad Walisongo by Yudhi AW, Wali Sanga by  Shashangka, Kisah Dakwah Wali Songo by Kusuma. Data this research is words, sentence, and discourse in three novels. To analyze them is used nautical direction and a critic of literature sociology. The results of this research is that two novels worked Wali Sanga by  Shashangka and Babad Walisongo by Yudhi Aw can provide the cristalization of discourse interaction in walisongo while, the novel Kisah Dakwah Wali Songo don’t appear that things.

  4. Evaluation for leaded and unleaded Gasoline as Hazardous Waste

    International Nuclear Information System (INIS)

    Abou El Naga, H.H.

    1999-01-01

    With the phase out of alkyl lead compounds as necessary additives for gasoline in order to raise its octane number , the alternative is to reformulate gasoline to have nearly same octane number but with other chemical structures. Such reformulated gasoline (RFG) is found to contain higher aromatics, benzene, iso paraffins, in comparison to leaded gasoline. Additionally, this reformulated gasoline can also contain oxygenated additives. Accordingly, this paper is aiming at evaluation of emitted hazardous chemical compounds from car engines at fuel combustion. Role of chemical structures for reformulated gasoline in emission of volatile organic compounds (VOC) and poisoning materials are considered

  5. Enfermedad por depósito de cristales de pirofosfato cálcico en la articulación temporomandibular con extensión intracraneal: A propósito de un caso Calcium pyrophosphate deposition disease of the temporomandibular joint with intracranial extension: A case report

    Directory of Open Access Journals (Sweden)

    I. Zubillaga Rodríguez

    2011-03-01

    Full Text Available Introducción: La articulación temporomandibular (ATM humana es un conjunto de estructuras que permite la relación anatómica y funcional entre el hueso temporal y la mandíbula. Los síntomas y signos asociados a los procesos neoplásicos-seudotumorales de la ATM son similares a los asociados a los trastornos temporomandibulares. Caso clínico: Presentamos un nuevo caso clínico de enfermedad por depósito de cristales de pirofosfato cálcico deshidratado (EDCPCD con afectación de la ATM e invasión intracraneal. Se trata de una artropatía microcristalina que comparte características clínicas con la condromatosis sinovial. Se exponen los aspectos claves relativos al diagnóstico y el tratamiento de dicha patología. Discusión: Los tumores que más frecuentemente afectan la ATM son las metástasis de tumores malignos. Entre las lesiones tumorales-seudotumorales que se originan directamente de la membrana sinovial se encuentran la condromatosis sinovial, la sinovitis villo-nodular, el sarcoma sinovial, la gota tofácea y la EDCPCD. Esta última es relativamente común en edades avanzadas, particularmente en la rodilla. El análisis de los cristales es esencial para establecer un diagnóstico de certeza. El tratamiento es eminentemente quirúrgico. Conclusiones: La EDCPCD en la ATM es extremadamente rara. Las masas tumorales que surgen como tumores primarios en la ATM representan un problema diagnóstico desafiante. La variada presentación de estas lesiones a menudo enmascara la patología de base y conlleva su retraso en el diagnóstico.Introduction: The human temporomandibular joint (TMJ is the structural complex that supports the functional and anatomic relations between the temporal bone and mandible. Symptoms and signs related to neoplastic or pseudotumoral disease of this joint are similar to the symptoms associated with temporomandibular joint dysfunction. Case report: We report a new case of calcium pyrophosphate deposition disease

  6. A Double-Edged Sword? On the Benefit, Detriment, and Net Effect of Dimensional Comparison on Self-Concept

    Science.gov (United States)

    Müller-Kalthoff, Hanno; Jansen, Malte; Schiefer, Irene M.; Helm, Friederike; Nagy, Nicole; Möller, Jens

    2017-01-01

    Dimensional comparison theory (DCT; Möller & Marsh, 2013) assumes that students compare their academic achievement intraindividually across domains to form domain-specific self-concepts. Upward dimensional comparisons are believed to lead to lower self-concepts in the worse-off domain, while downward dimensional comparisons should lead to…

  7. Composición y procedimiento de obtención de azulejos cerámicos de gres porcelánico reforzados

    OpenAIRE

    Fernández Lozano, José Francisco; Jiménez Reinosa, Julián; Vela Carrascosa, Enrique; García Tomas, Fernando

    2012-01-01

    La presente invención trata de un gres porcelánico que comprende cristales de silicatos seleccionados de la lista que comprende silicatos de magnesio, silicatos de hierro o silicatos de magnesio y hierro, donde los cristales están homogéneamente distribuidos y tienen un tamaño medio de de 20nm a 1000nm, preferiblemente de 50 a 500nm. Asimismo esta invención trata del procedimiento de obtención de dichos productos de gres porcelánico

  8. Identificación de los Genes cry en Cepas Mexicanas de Bacillus thuringiensis con Potencial Insecticida Identificación de los Genes cry en Cepas Mexicanas de Bacillus thuringiensis con Potencial Insecticida

    Directory of Open Access Journals (Sweden)

    J. E. Ibarra

    2012-02-01

    Full Text Available En el presente estudio se determinó la morfología y la composición proteica de los cristales de las cepas LBIT-499 y LBIT-504 de B. thuringiensis, ambas nativas de Guanajuato, México. La primera mostró sólo cristales bipiramidales mientras que la segunda presentó cristales tanto bipiramidales como cúbicos. Estos cristales estuvieron compuestos de proteínas de aproximadamente 130 y 60 kDa, respectivamente. En ambas cepas, además de la LBIT-500 y LBIT-544, se detectó una gran variedad de genes cry1. En éstas últimas se encontraron los genes cry2A y cry2B, en la LBIT- 504 sólo el cry2B y en la LBIT-499 no se detectó ningún cry2. This report revealed the crystal morphology and protein composition of strains LBIT-499 and LBIT-504 of B. thuringiensis, native to Guanajuato, Mexico. LBIT-499 showed only bipyramidal crystals, while LBIT-504 showed both bipyramidal and cubical crystals. These crystals were composed by proteins of ca. 130 and 60 kDa, respectively. Both strains as well as LBIT-500 and LBIT-544, showed a great variety of cry1 genes, while cry2A and cry2B were identified in LBT-500 and LBIT-544, LBIT-504 showed only the cry2B gene, and no cry2 was detected in LBIT-499.

  9. Embryonic exposure to lead: comparison of immune and cellular responses in unchallenged and virally stressed chickens

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji-Eun; Kao, Elizabeth; Dietert, Rodney R. [Institute for Comparative and Environmental Toxicology, College of Veterinary Medicine, Cornell University, Ithaca, NY (United States); Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY (United States); Naqi, Syed A. [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY (United States)

    2002-01-01

    Lead, a ubiquitous environmental contaminant, has been shown to modulate various functions of the immune system and decrease host resistance to infectious disease. However, limited information is available concerning the direct effects of lead on the host immune response to an infectious agent after developmental exposure. The current study utilized chickens to examine the effect of embryonic lead exposure on immune and cellular responses during viral challenge. Sublethal doses of lead were introduced into fertilized Cornell K Strain White Leghorn chicken eggs via the air sac at day 5 or day 12 of embryonic development (designated as E5 and E12, respectively). Four-week-old female chickens were inoculated with infectious bronchitis virus (IBV) strain M41. Antibody titer to IBV, delayed-type hypersensitivity (DTH) response against bovine serum albumin (BSA), the absolute number and percentage of leukocyte subpopulations, and interferon-{gamma} (IFN-{gamma})-like cytokine production by splenocytes were evaluated at 5-6 weeks of age. While antibody response to IBV in juvenile chicks was unaffected by the in ovo lead exposure, IFN-{gamma}-like cytokine production by splenocytes was significantly depressed following lead exposure at both developmental stages. In contrast with this pattern, the DTH response against BSA was unaffected following E5 exposure, but was significantly decreased after E12 exposure to lead. These changes were similar to those previously reported in chickens not exposed to IBV. While lead exposure at E5 induced significant changes in the percentage of circulating heterophils at 1 day postinfection (dpi), lead did not cause any change in relative leukocyte counts after E12 exposure. At 7 dpi, E5 lead exposure resulted in decreased absolute number and percentage of circulating lymphocytes, while total leukocyte counts, and the absolute number and percentage of circulating monocytes and heterophils were significantly reduced in E12 lead

  10. Neutron Physics aspects of using lead as a coolant in Fast Reactors

    International Nuclear Information System (INIS)

    Kiefhaber, E.

    1991-02-01

    The use of lead as a coolant for fast reactors is being considered as an attractive alternative in the USSR, especially with respect to its inherent safety features. In order to come to an own assessment at KfK, some investigations have been performed concerning a comparison of the nuclear characteristics of fast reactors with lead and sodium cooling. The studies have shown, that the nuclear and thermal hydraulic design calculations do not face special problems and that the nuclear characteristics of both types of cores do not differ essentially, except for the coolant density or void effect, which is more favourable for smaller sized lead cooled cores. A proper safety assessment of lead cooled cores will however require more detailed safety studies. Crucial points of lead cooling are the strong corrosion of austenitic steels in lead and the unknown behavior of ferritic steels in lead and under irradiation

  11. Composición y procedimiento de obtención de azulejos cerámicos de gres porcelánico reforzados

    OpenAIRE

    Fernández Lozano, José Francisco; Jiménez Reinosa, Julián; Vela Carrascosa, Enrique; García Tomas, Fernando

    2012-01-01

    Composición y procedimiento de obtención de azulejos cerámicos de gres porcelánico reforzados. La presente invención trata de un gres porcelánico que comprende cristales de silicatos seleccionados de la lista que comprende silicatos de magnesio, silicatos de hierro o silicatos de magnesio y hierro, donde los cristales están homogéneamente distribuidos y tienen un tamaño medio de de 20nm a 1000nm, preferiblemente de 50 a 500nm. Asimismo esta invención trata del proce...

  12. Third-order nonlinearity of Er3+-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Guedes Da Silva, Ilde [ORNL; Siqueira, J. P. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Misoguti, L. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Zilio, S. C. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Boatner, Lynn A [ORNL

    2010-01-01

    The third-order optical susceptibility and dispersion of the linear refractive index of Er3+-doped lead phosphate glass were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index obtained from the third-order susceptibility was found to be five times higher than that of silica, indicating that Er3+-doped lead phosphate glass is a potential candidate to be used as the base component for the fabrication of photonic devices. For comparison purposes, the Z-scan technique was also employed to obtain the values of the nonlinear refractive index of E-doped lead phosphate glass at several wavelengths, and the values obtained using the two techniques agree to within 15%.

  13. Thermal restoration of the lattice parameter of weakly irradiated UO{sub 2} (1962); Restauration thermique de parametre du l'UO{sub 2} faiblement irradie (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    Weak irradiations of uranium dioxide lead to an expansion of the cristal lattice. We have studied the restoration of the lattice parameter after successive isochronous annealings. The process occurs in two main stages, one starting at 200 deg. C and the other at 500 deg. C. (author) [French] De faibles irradiations du bioxyde d'uranium produisent une dilatation de la maille cristalline. Nous avons etudie la restauration du parametre apres des recuits isochrones successifs. Elle se fait en deux stades principaux: l'un a partir de 200 deg. C, l'autre a partir de 500 deg. C. (auteur)

  14. SU-E-I-56: Diagnostic Lead Apron Radiation Exposure Comparison Between Manufacture-Stated and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Syh, J; Patel, B; Syh, J; Song, X; Freund, D; Ding, X; Wu, H [Willis-Knighton Medical Center, Shreveport, LA (United States)

    2015-06-15

    Purpose: Several vendors of diagnostic lead apron used routinely in radiology/fluoroscopy claim to manufacture 0.5 mm lead equivalent shielding. The purpose of this investigation was to address the concern of the weight of lead aprons versus the radiation protection they provide. Methods: Seven diagnostic lead aprons were measured and compared for their radiation transmission and attenuation characteristics. The measurements were performed on a Philips Integris. Two settings were used, normal (76 kVp, 14.3 mA) and high (110 kVp, 12.3 mA) to represent typical patient and large patient thickness. Plastic water was placed on the table to represent patient scatter. A Capintec PM-500 ion chamber was placed at approximate chest height where hospital personnel would stand. An uncovered, i.e. lead-unhindered, ion chamber reading was taken to establish the baseline reading of an unprotected personnel. The ion chamber was then wrapped with 0.5mm 99.9% pure Pb material to establish the measurement reading when a diagnostic lead apron attenuates as adequately as 0.5mm Pb. The lead aprons were measured one at a time with the ion chamber fully covered and enclosed within the aprons. Results: On Normal fluoroscopy setting, the 0.5mm pure Pb showed a transmission of 0.4%. No aprons showed a transmission value as low as 0.5mm Pb. The lowest transmission value measured from the aprons was 2.0%, having a 1.5% higher transmission than pure lead. On High fluoroscopy setting, the lowest apron transmission measurement was at 2.8%, which was comparable to the 0.5mm pure Pb which gave a transmission of 3.0%. Conclusion: At Normal fluoroscopy setting, the 0.5mm Pb provided an attenuation that could not be matched by any apron measured. At High fluoroscopy setting, only one apron exhibited comparable transmission values as 0.5mm pure Pb.

  15. SU-E-I-56: Diagnostic Lead Apron Radiation Exposure Comparison Between Manufacture-Stated and Measurements

    International Nuclear Information System (INIS)

    Syh, J; Patel, B; Syh, J; Song, X; Freund, D; Ding, X; Wu, H

    2015-01-01

    Purpose: Several vendors of diagnostic lead apron used routinely in radiology/fluoroscopy claim to manufacture 0.5 mm lead equivalent shielding. The purpose of this investigation was to address the concern of the weight of lead aprons versus the radiation protection they provide. Methods: Seven diagnostic lead aprons were measured and compared for their radiation transmission and attenuation characteristics. The measurements were performed on a Philips Integris. Two settings were used, normal (76 kVp, 14.3 mA) and high (110 kVp, 12.3 mA) to represent typical patient and large patient thickness. Plastic water was placed on the table to represent patient scatter. A Capintec PM-500 ion chamber was placed at approximate chest height where hospital personnel would stand. An uncovered, i.e. lead-unhindered, ion chamber reading was taken to establish the baseline reading of an unprotected personnel. The ion chamber was then wrapped with 0.5mm 99.9% pure Pb material to establish the measurement reading when a diagnostic lead apron attenuates as adequately as 0.5mm Pb. The lead aprons were measured one at a time with the ion chamber fully covered and enclosed within the aprons. Results: On Normal fluoroscopy setting, the 0.5mm pure Pb showed a transmission of 0.4%. No aprons showed a transmission value as low as 0.5mm Pb. The lowest transmission value measured from the aprons was 2.0%, having a 1.5% higher transmission than pure lead. On High fluoroscopy setting, the lowest apron transmission measurement was at 2.8%, which was comparable to the 0.5mm pure Pb which gave a transmission of 3.0%. Conclusion: At Normal fluoroscopy setting, the 0.5mm Pb provided an attenuation that could not be matched by any apron measured. At High fluoroscopy setting, only one apron exhibited comparable transmission values as 0.5mm pure Pb

  16. Pregnancy increases mobilisation of lead from maternal skeleton

    International Nuclear Information System (INIS)

    Gulson, B.L.

    2000-01-01

    Lead is a neurotoxin that, even at low levels, is considered to result in neurobehavioural disorders such as cognitive deficits, learning disability and behavioural disturbances. The most recent study of Needleman et al. suggested an association between bone lead levels and antisocial and delinquent behaviour (Needleman et al., 1996). Although the neurobehavioural deficits associated with low-level lead exposure are best documented for early childhood exposures, the effects of lead on the developing nervous system are of concern. Lead readily crosses the placenta (Barltrop, 1969; Silbergeld, 1991) and changes in maternal blood lead potentially result in alterations to foetal exposure. Mobilisation of lead from body stores accumulated prior to pregnancy has been established in experimental animals (Buchet, 1977; Keller and Doherty, 1980). The cohort was to consist of 100 immigrants anticipated to provide 20 pregnant subjects who would be compared with two groups of control subjects: a matched immigrant nonpregnant control group and second-generation Australian pregnant controls. The pregnant subject also serves as her own control for a comparison of changes during pregnancy with those prior to conception. High precision lead isotopic compositions and lead concentrations were measured on: maternal blood and urine prenatally, monthly during pregnancy and post-pregnancy for 6 months; infant blood and urine for 6 months; and environmental measures sampled quarterly for 6-day duplicate diet, house dust and water, urban air and petrol. Results of this study confirm that lead is mobilised from skeletal stores at an accelerated rate during pregnancy and transferred to the foetus. This has implications for interpretations of neurobehavioural disorders attributed solely to post-natal exposure

  17. Study of core flow distribution for small modular natural circulation lead or lead-alloy cooled fast reactors

    International Nuclear Information System (INIS)

    Chen, Zhao; Zhao, Pengcheng; Zhou, Guangming; Chen, Hongli

    2014-01-01

    Highlights: • A core flow distribution calculation code for natural circulation LFRs was developed. • The comparison study between the channel method and the CFD method was conducted. • The core flow distribution analysis and optimization design for a 10MW natural circulation LFR was conducted. - Abstract: Small modular natural circulation lead or lead-alloy cooled fast reactor (LFR) is a potential candidate for LFR development. It has many attractive advantages such as reduced capital costs and inherent safety. The core flow distribution calculation is an important issue for nuclear reactor design, which will provide important input parameters to thermal-hydraulic analysis and safety analysis. The core flow distribution calculation of a natural circulation LFR is different from that of a forced circulation reactor. In a forced circulation reactor, the core flow distribution can be controlled and adjusted by the pump power and the flow distributor, while in a natural circulation reactor, the core flow distribution is automatically adjusted according to the relationship between the local power and the local resistance feature. In this paper, a non-uniform heated parallel channel flow distribution calculation code was developed and the comparison study between the channel method and the CFD method was carried out to assess the exactness of the developed code. The core flow distribution analysis and optimization design for a 10MW natural circulation LFR was conducted using the developed code. A core flow distribution optimization design scheme for a 10MW natural circulation LFR was proposed according to the optimization analysis results

  18. End-stage renal disease after occupational lead exposure: 20 years of follow-up.

    Science.gov (United States)

    Evans, Marie; Discacciati, Andrea; Quershi, Abdul Rashid; Åkesson, Agneta; Elinder, Carl-Gustaf

    2017-06-01

    Whether low-level exposure to lead may give rise to chronic kidney disease or end-stage renal disease (ESRD) is debated. In this study, we aimed to specifically investigate if low-level occupational exposure to lead was associated with increased incidence of ESRD. The incidence of starting renal replacement therapy as a result of ESRD was examined in a cohort of10 303 lead-workers who had controlled blood lead concentrations due to a compulsory occupational health surveillance programme in Sweden during the time period 1977-1990. The ESRD incidence (obtained through register-linkage) among the lead-exposed workers was compared with the age, sex and calendar period-adjusted expected incidence based on data from the Swedish renal registry. Dose-response association was evaluated in external (general population) and internal (within the occupational cohort) comparisons by highest achieved blood lead level. There were 30 (0.29%) individuals in the cohort who developed ESRD during the median follow-up period of 26.3 years. The standardised incidence ratio (SIR) for ESRD incidence was 0.79 (95% CI 0.54 to 1.13). Among those who achieved the highest blood lead (>41.4 µg/dL), the SIR was 1.01 (0.44 to 1.99). There was no evidence of a dose-response relationship between the maximum achieved blood lead or the cumulative blood lead exposure and ESRD in external or internal comparisons. This study of workers with documented occupational lead exposures followed for 20 years shows no statistically significant association between lead exposure (following the current occupational recommendations for Sweden) and ESRD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Anthropogenic impact and lead pollution throughout the Holocene in Southern Iberia.

    Science.gov (United States)

    García-Alix, A; Jimenez-Espejo, F J; Lozano, J A; Jiménez-Moreno, G; Martinez-Ruiz, F; García Sanjuán, L; Aranda Jiménez, G; García Alfonso, E; Ruiz-Puertas, G; Anderson, R Scott

    2013-04-01

    Present day lead pollution is an environmental hazard of global proportions. A correct determination of natural lead levels is very important in order to evaluate anthropogenic lead contributions. In this paper, the anthropogenic signature of early metallurgy in Southern Iberia during the Holocene, more specifically during the Late Prehistory, was assessed by mean of a multiproxy approach: comparison of atmospheric lead pollution, fire regimes, deforestation, mass sediment transport, and archeological data. Although the onset of metallurgy in Southern Iberia is a matter of controversy, here we show the oldest lead pollution record from Western Europe in a continuous paleoenvironmental sequence, which suggests clear lead pollution caused by metallurgical activities since ~3900 cal BP (Early Bronze Age). This lead pollution was especially important during Late Bronze and Early Iron ages. At the same time, since ~4000 cal BP, an increase in fire activity is observed in this area, which is also coupled with deforestation and increased erosion rates. This study also shows that the lead pollution record locally reached near present-day values many times in the past, suggesting intensive use and manipulation of lead during those periods in this area. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Upward and Downward: Social Comparison Processing of Thin Idealized Media Images

    Science.gov (United States)

    Tiggemann, Marika; Polivy, Janet

    2010-01-01

    The present study aimed to investigate the role of social comparison processing in women's responses to thin idealized images. In particular, it was predicted that comparison with the images on the basis of appearance would lead to more negative outcomes than comparison on the basis of intelligence. A sample of 114 women viewed fashion magazine…

  1. Determination of the Dissolution Slowness Surface by Study of Etched Shapes: II. Comparison of 2D Experimental and Theoretical Etching Shapes

    Science.gov (United States)

    Leblois, T.; Tellier, C. R.; Messaoudi, T.

    1997-03-01

    The anisotropic etching behavior of quartz crystal in concentrated ammonium bifluoride solution is studied and analyzed in the framework of a tensorial model. This model allows to simulate bi- or three-dimensional etching shapes from the equation for the representative surface of the dissolution slowness. In this paper, we present experimental results such as surface profile and initially circular cross-sectional profiles of differently singly- or doubly-rotated cuts. The polar diagrams of the dissolution slowness vector in several planes are deduced from experimental data. The comparison between predicted surface and cross-sectional profiles and experimental results is detailed and shows a good agreement. In particular, several examples give evidence that the final etched shapes are correlated to the extrema of the dissolution slowness. However, in several cases, experimental shapes cannot be simply correlated to the presence of extrema. Simulation gives effectively evidence for an important role played by more progressive changes in the curvature of the slowness surface. Consequently, analysis of data merits to be treated carefully. Nous nous proposons d'étudier et d'analyser à l'aide du modèle tensoriel de la dissolution l'attaque chimique anisotrope du cristal de quartz dans une solution concentrée de bifluorure d'ammonium. Ce modèle permet de simuler des formes usinées à deux ou trois dimensions à partir de l'équation de la surface représentative de la lenteur de dissolution du cristal de quartz. Dans cet article, nous présentons des résultats expérimentaux concernant des profils de surface et des sections initialement cylindriques de coupes à simple et double rotation. Les diagrammes polaires du vecteur lenteur de dissolution dans différents plans sont déduits de données expérimentales. La comparaison entre les profils de surface et de section théoriques et les résultats expérimentaux est détaillée et montre un bon accord. En

  2. Safety considerations of lithium lead alloy as a fusion reactor breeding material

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Muhlestein, L.D.

    1985-01-01

    Test results and conclusions are presented for lithium lead alloy interactions with various gas atmospheres, concrete and potential reactor coolants. The reactions are characterized to evaluate the potential of volatilizing and transporting radioactive species associated with the liquid breeder under postulated fusion reactor accident conditions. The safety concerns identified for lithium lead alloy reactions with the above materials are compared to those previously identified for a reference fusion breeder material, liquid lithium. Conclusions made from this comparison are also included

  3. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    International Nuclear Information System (INIS)

    Fang, J.; Yu, T.; Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J.

    2013-01-01

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current

  4. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J., E-mail: fangseer@sina.com [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Yu, T. [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J. [China Electric Power Research Institute, Haidian District, Beijing (China)

    2013-11-15

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current.

  5. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome

    DEFF Research Database (Denmark)

    Nielsen, Jens Cosedis; Thomsen, Poul Erik B; Højberg, Søren

    2011-01-01

    In patients with sick sinus syndrome, bradycardia can be treated with a single-lead pacemaker or a dual-chamber pacemaker. Previous trials have revealed that pacing modes preserving atrio-ventricular synchrony are superior to single-lead ventricular pacing, but it remains unclear if there is any ...

  6. Surface dust wipes are the best predictors of blood leads in young children with elevated blood lead levels

    Energy Technology Data Exchange (ETDEWEB)

    Gulson, Brian, E-mail: brian.gulson@mq.edu.au [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); CSIRO Earth Science and Resource Engineering, North Ryde NSW 2113 (Australia); Anderson, Phil [Information and Statistics Group, Australian Institute of Health and Welfare, Canberra ACT 2601 (Australia); Faculty of Health, University of Canberra, Canberra ACT 2601 (Australia); Taylor, Alan [Department of Psychology, Macquarie University, Sydney NSW 2109 (Australia)

    2013-10-15

    Background: As part of the only national survey of lead in Australian children, which was undertaken in 1996, lead isotopic and lead concentration measurements were obtained from children from 24 dwellings whose blood lead levels were ≥15 µg/dL in an attempt to determine the source(s) of their elevated blood lead. Comparisons were made with data for six children with lower blood lead levels (<10 µg/dL). Methods: Thermal ionisation and isotope dilution mass spectrometry were used to determine high precision lead isotopic ratios ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb and {sup 206}Pb/{sup 204}Pb) and lead concentrations in blood, dust from floor wipes, soil, drinking water and paint (where available). Evaluation of associations between blood and the environmental samples was based on the analysis of individual cases, and Pearson correlations and multiple regression analyses based on the whole dataset. Results and discussion: The correlations showed an association for isotopic ratios in blood and wipes (r=0.52, 95% CI 0.19–0.74), blood and soil (r=0.33, 95% CI −0.05–0.62), and blood and paint (r=0.56, 95% CI 0.09–0.83). The regression analyses indicated that the only statistically significant relationship for blood isotopic ratios was with dust wipes (B=0.65, 95% CI 0.35–0.95); there were no significant associations for lead concentrations in blood and environmental samples. There is a strong isotopic correlation of soils and house dust (r=0.53, 95% CI 0.20–0.75) indicative of a common source(s) for lead in soil and house dust. In contrast, as with the regression analyses, no such association is present for bulk lead concentrations (r=−0.003, 95% CI −0.37–0.36), the most common approach employed in source investigations. In evaluation of the isotopic results on a case by case basis, the strongest associations were for dust wipes and blood. -- Highlights: • Children with elevated blood lead ≥15 µg/dL compared with a group with <10

  7. Performance comparison of metallic, actinide burning fuel in lead-bismuth and sodium cooled fast reactors

    International Nuclear Information System (INIS)

    Weaver, K.D.; Herring, J.S.; Macdonald, P.E.

    2001-01-01

    Various methods have been proposed to ''incinerate'' or ''transmute'' the current inventory of transuranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years. (author)

  8. 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.

  9. Comparative study of tungsten and lead as gamma ray shielding material

    International Nuclear Information System (INIS)

    Wang Jian; Zou Shuliang

    2011-01-01

    This article firstly compares the tungsten and lead's physical properties, price and environmental performance, then calculates the thickness of tungsten and lead with the gamma ray 10% transmission when the photon energy are 0.1 MeV, 0.2 MeV, 0.5, 1 MeV and 1.25 MeV, and makes a comparison chart. Finally, it establishes a commonly used shielding model, through which to validate whether the thickness of theoretical calculation can achieve an effective shielding effect by MCNP program. The results showers that tungsten as a new type of shielding material has a lot of advantages, which shielding ability is far higher than the lead. Thus it provides the reference to choose the suitable shielding materials in special occasions. (authors)

  10. A comparison of the effect of lead nitrate on rat liver chromatin, DNA and histone proteins in solution.

    Science.gov (United States)

    Rabbani-Chadegani, Azra; Abdosamadi, Sayeh; Fani, Nesa; Mohammadian, Shayesteh

    2009-06-01

    Although lead is widely recognized as a toxic substance in the environment and directly damage DNA, no studies are available on lead interaction with chromatin and histone proteins. In this work, we have examined the effect of lead nitrate on EDTA-soluble chromatin (SE chromatin), DNA and histones in solution using absorption and fluorescence spectroscopy, thermal denaturation and gel electrophoresis techniques. The results demonstrate that lead nitrate binds with higher affinity to chromatin than to DNA and produces an insoluble complex as monitored at 400 nm. Binding of lead to DNA decreases its Tm, increases its fluorescence intensity and exhibits hypochromicity at 210 nm which reveal that both DNA bases and the backbone participate in the lead-DNA interaction. Lead also binds strongly to histone proteins in the absence of DNA. The results suggest that although lead destabilizes DNA structure, in the chromatin, the binding of lead introduces some sort of compaction and aggregation, and the histone proteins play a key role in this aspect. This chromatin condensation, upon lead exposure, in turn may decrease fidelity of DNA, and inhibits DNA and RNA synthesis, the process that introduces lead toxicity at the chromatin level.

  11. 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

  12. 'Do lead rubber aprons pose an infection risk?'

    International Nuclear Information System (INIS)

    Boyle, Helen; Strudwick, Ruth M.

    2010-01-01

    This study was carried out in order to establish whether infection control measures were being undertaken sufficiently on lead rubber aprons within a diagnostic imaging department in the east of England. This study involved the swabbing of a sample of 15 lead rubber aprons used within different areas of the department. Swabs were taken from the area on the underside of the shoulders and from the front of the apron. Each apron was firstly swabbed to determine the current level of microorganism contamination (determination of baseline data) and then again after recommended cleaning with detergent and water (the production of a standard). Comparisons were then made between the number of microorganisms' present (colony forming units/cm 2 ) pre and post-cleaning at each location. Additionally, post-cleaning data was compared for each location. All aprons were found to be contaminated with microorganisms, those identified were Coagulase-negative staphylococci, Staphylococcus aureus, Bacillus, Diphtheroids and some fungal spores. No Methicillin resistant strains of Staphylococcus aureus (MRSA) were identified. Recommended cleaning with detergent and water was found to significantly reduce the amount of microorganisms present (the detergent used was Hospec general purpose neutral liquid detergent). Comparisons of the sample sites found that the front of the apron had lower levels of microorganism contamination post-cleaning than the site at the underside of the shoulders. The results suggest that the lead rubber aprons were not being cleaned sufficiently which has infection control implications for the department. In order for cross contamination to be kept to a minimum an effective infection control policy needs to be employed and this should be to carry out regular cleaning with detergent and water which has been shown can significantly reduce contamination.

  13. Blood lead levels in children with neurological disorders: a single centre preliminary study.

    Science.gov (United States)

    Mahmoudian, Touran; Modaresi, Mohamadreza; Zarei, Ali; Poursafa, Parinaz; Kelishadi, Roya

    2009-11-01

    Lead poisoning is a potentially devastating problem among young children. Chronic low level lead exposure can lead to learning disabilities and behavior changes such as colic, insomnia, hyperactivity, impaired growth, hearing loss and upper extremity weakness. The purpose of this cross sectional study was to determine the blood lead level in children with neurological disorders in comparison with healthy controls. Blood lead concentrations were measured by flame atomic absorption spectrometry in 100 children aged 1-10 years and suffering from various neurological disorders. One hundred age and sex-matched healthy children served as controls. The mean blood lead concentration was higher in children with neurological disorders than in controls (113.2 + or - 47.5 microg/L vs 84.7 + or - 38.0 microg/L; pchildren with neurological disorders and 19% of controls were found to have increased blood lead levels, i.e.>100 microg/L. An increase in blood lead level in children might be related to neurological disorders. The measurement of blood lead level might be included in diagnostic eveluation of children with neurological disorders.

  14. Magnetoresistance sensitivity mapping of the localized response of contiguous and lead-overlaid sensors

    International Nuclear Information System (INIS)

    Sankar, Sandra

    2003-01-01

    Magnetoresistance sensitivity mapping (MSM) was used to investigate the local response of magnetic recording sensors without convolution of the writer, magnetic media and data channel. From a 2D map of the local sensor response, the intrinsic pulse shape and magnetic track profile are readily obtained. Pulse-width is a concern for high data rate since if pulse-width is too broad, individual transitions become difficult to distinguish. Track profiles are important because due to the small difference between magnetic write-width and magnetic read-width, side reading will lead to an increase in noise. Three experiments are discussed: the dependence of the pulse-width (PW50) of the standard contiguous junction (CJ) design on shield-to-shield spacing; a comparison of the pulse shape of lead-overlaid (LOL) and CJ designs; and a comparison of the magnetic track profile (including track-width and skirt ratio) of LOL and CJ designs. The LOL design offers an increased sensitivity; however, as seen from MSM, the penalties are broadening of the track and pulse profiles. These are a direct result of the finite current in the lead overlay region and an increased shield-to-shield spacing in that region. The MSM image shows a curvature, which is associated with the topography of the top shield due to the lead overlay

  15. Comparison of the transient behavior of lead-based advanced critical and sub-critical reactors

    International Nuclear Information System (INIS)

    Wang Gang; Gu Zhixing; Wang Zhen; Jin Ming; Bai Yunqing

    2014-01-01

    A lead-based reactor developed by FDS Team is proposed in 2011 and designed to be 10 MW. It is a pool type reactor and the primary coolant is driven by natural circulation. The reactor has two operation modes, which are a lead-based critical fast reactor mode and a lead-based sub-critical reactor mode. The conceptual designs of the two modes are both completed by 2013. In this paper, four transient accidents were simulated for both the critical and sub-critical reactors above by NTC-2D code, which is developed by FDS Team for advanced reactor safety analysis. The four accidents were protected and unprotected loss of heat sink accidents (PLOHS and ULOHS), protected and unprotected transient overpower accidents (PTOP and UTOP). The simulation results of the two reactors were compared and analyzed. The results showed that during PLOHS and PTOP accidents for both the two modes, all the key parameters (core power, fuel, cladding and coolant temperatures in the hottest channel) decreased to very small values after the reactor scrammed, which meant the reactors under the two modes were both safe. For ULOHS, the fuel, cladding and coolant temperatures of the sub-critical reactor increased bigger than those of the critical one. For UTOP, the parameters above of the critical fast reactor were much bigger than those of the sub-critical one. The analysis results showed different safety advantages of the lead-based critical fast and sub-critical reactors during different transient accidents. (author)

  16. The technical and economic efficiency in the mineral processing for lead-zinc and copper ores by Microsoft excel

    OpenAIRE

    Krstev, Aleksandar; Krstev, Boris; Krstev, Dejan; Vuckovski, Zoran

    2012-01-01

    The comparisons between economical and technical efficiency for lead flotation indicators, zinc flotation indicators in Sasa mine, Toranica and Zletovo mine. The comparisons for economic and technical efficiency for copper flotation indicators in Bucim mine. The possibility of equaled between both efficiencies for flotation indicators from mentioned mines using Microsoft Excel 2010.

  17. 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

  18. Gender Differences in Comparisons and Entitlement: Implications for Comparable Worth.

    Science.gov (United States)

    Major, Brenda

    1989-01-01

    Addresses the role of comparison processes in the persistence of the gender wage gap, its toleration by those disadvantaged by it, and resistance to comparable worth as a corrective strategy. Argues that gender segregation and undercompensation for women's jobs leads women to use different comparison standards when evaluating what they deserve.…

  19. Comparison of lead levels in human permanent teeth from Strasbourg, Mexico City, and rural zones of Alsace

    International Nuclear Information System (INIS)

    Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J.

    1990-01-01

    A comparative study of the mean lead concentrations in enamel and dentin of human premolars and permanent molars was conducted by means of a systematic sampling procedure with energy-dispersive x-ray fluorescence analysis. In a first series of analyses, no significant statistical differences in mean lead concentrations at various levels of enamel and dentin were noted between young patients of Strasbourg and those of small villages of Alsace, nor between elderly patients living in these two locations, despite the fact that motor traffic was significantly lower in the rural zones. However, in both locations, a significantly higher concentration of lead was observed in enamel and dentin in relation to age. In a second series of analyses, the mean lead concentrations of both dental hard tissues of premolars and permanent molars of young individuals from Strasbourg, rural Alsace, and Mexico City were compared. Significantly higher mean lead concentrations were found in enamel and dentin samples from Mexico City. This was most evident for inner coronal dentin (5.7 and 6.1 times greater than in teeth of Strasbourg and rural zones of Alsace, respectively) and for pulpal root dentin (6.9 and 8.9 times greater than in teeth of Strasbourg and rural zones of Alsace). It is proposed that the higher lead concentrations are related to the higher lead content of motor gasoline and to more intense traffic conditions. The dental hard tissues appear to be of value for the study of environmental lead pollution

  20. A comparison of the prevalence of lead-contaminated imported Chinese ceramic dinnerware purchased inside versus outside Philadelphia's Chinatown.

    Science.gov (United States)

    Gilmore, Thomas; O'Malley, Gerald F; Lau, Wayne Bond; Vann, David R; Bromberg, Adam; Martin, Aaron; Gibbons, Andrea; Rimmer, Evan

    2013-03-01

    Lead-contaminated ceramics can be a clinically significant source of lead poisoning, with the potential to cause illness in children and adults; one death in a child has been described. We hypothesized that the prevalence of lead-contaminated ceramics would be higher within Chinatown versus outside of Chinatown. The study was a prospective observational cross-sectional study. Two areas were defined geographically as being within and outside of Philadelphia's Chinatown, and a predefined number of items were purchased in each area. Each item was screened for lead utilizing a colorimetric testing swab. Positive items were leached for lead using the ASTM C738-94 protocol for lead level quantification. The primary outcome was the prevalence of ceramics not compliant with the FDA standard for leachable lead within and outside of Philadelphia's Chinatown. A total of 132 items were purchased, 46 outside of and 86 within Chinatown. More lead-positive items originated within Chinatown than outside of Chinatown [five positive items, 5.8 % prevalence within Chinatown (95 % confidence interval, CI, 2.5-12.9 %), and zero positive, 0 % prevalence outside of Chinatown (95 % CI 0-7.5 %)]. However, this difference was not found to be statistically significant (P = 0.1624). The leachable lead-positive items were up to 40-fold the acceptable FDA levels. Testing a larger number of items may demonstrate a significant source of lead exposure.

  1. Neutron Production in Spallation Reactions of 0.9 and 1.5 GeV Protons on a Thick Lead Target. Comparison between Experimental Data and Monte-Carlo Simulations

    CERN Document Server

    Krasa, A; Bradnova, V; Caloun, P; Chultem, D; Henzl, V; Henzlová, D; Kalinnikov, V G; Krivopustov, M I; Krízek, F; Kugler, A; Majerle, M; Solnyshkin, A A; Stegailov, V I; Tsoupko-Sitnikov, V M; Tumendelger, T; Vasilev, S I; Wagner, V; Nuclear Physics Institute of Academy of Sciences of Czech Republic, Rez, Czech Republic

    2005-01-01

    This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their $\\gamma$ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code.

  2. Neutron production in spallation reactions of 0.9 and 1.5 GeV protons on a thick lead target. Comparison between experimental data and Monte-Carlo simulations

    International Nuclear Information System (INIS)

    Krasa, A.; Krizek, F.; Wagner, V.; Kugler, A.; Henzl, V.; Henzlova, D.; Majerle, M.; Adam, J.; Caloun, P.; Bradnova, V.; Chultem, D.; Kalinnikov, V.G.; Krivopustov, M.I.; Solnyshkin, A.A.; Stegajlov, V.I.; Tsupko-Sitnikov, V.M.; Tumehndehlgehr, Ts.; Vasil'ev, S.I.

    2005-01-01

    This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their γ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code

  3. Synthesis of inorganic polymers using fly ash and primary lead slag.

    Science.gov (United States)

    Onisei, S; Pontikes, Y; Van Gerven, T; Angelopoulos, G N; Velea, T; Predica, V; Moldovan, P

    2012-02-29

    The present work reports on the synthesis and properties of inorganic polymers ("geopolymers") made of 100% fly ash from lignite's combustion, 100% primary lead slag and mixtures of the two. In the inorganic polymers with both fly ash and lead slag the main crystalline phases detected are wüstite, magnetite, sodium zinc silicate, quartz, anorthite, and gehlenite; litharge partially dissolves. FTIR analysis in these samples revealed that the main peaks and bands of end members also exist, along with a new amorphous reaction product. In terms of microstructure, both fly ash and lead slag dissolve and contribute in the binding phase whereas the larger particles act as aggregates. For an increasing lead slag in the composition, the binding phase is changing in chemistry and reaches PbO values higher than 50 wt.% for the 100% lead slag inorganic polymer. Regarding the properties of fly ash and lead slag inorganic polymers, compressive strength is higher than 35 MPa in all cases and water absorption diminishes as the lead slag content increases. A comparison of leaching results before and after polymerisation reveals that pH is an important factor as Pb is immobilised in the binding phase, unlike Zn and As. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. 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.

  5. 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

  6. 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.)

  7. 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

  8. PRINCIPIOS BÁSICOS DE ULTRASONOGRAFÍA VETERINARIA

    Directory of Open Access Journals (Sweden)

    Carlos Giraldo E.

    2003-12-01

    Full Text Available La tecnología del ultrasonido nace en 1880 con eldesarrollo de los efectos piezoeléctricos. Luego fueaplicada en forma de SONAR (Sound Navigation andRanging durante la segunda guerra mundial para ladetección de barcos, submarinos y aviones de guerra.La emisión de las ondas de ultrasonido se obtiene pormedio de cristales que son sometidos a una corrienteeléctrica logrando que vibren, la recepción de éstasondas se logra cuando retornan de nuevo a los cristalesal chocar con los tejidos. Estos cristales están contenidosen dispositivos llamados transductores o sondasecográficas conectadas a un monitor

  9. Blood Lead Toxicity Analysis of Multipurpose Canines and Military Working Dogs.

    Science.gov (United States)

    Reid, Paul; George, Clinton; Byrd, Christopher M; Miller, Laura; Lee, Stephen J; Motsinger-Reif, Alison; Breen, Matthew; Hayduk, Daniel W

    Special Operations Forces and their accompanying tactical multipurpose canines (MPCs) who are involved in repeated live-fire exercises and military operations have the potential for increased blood lead levels and toxicity due to aerosolized and environmental lead debris. Clinical lead-toxicity symptoms can mimic other medical disorders, rendering accurate diagnosis more challenging. The objective of this study was to examine baseline lead levels of MPCs exposed to indoor firing ranges compared with those of nontactical military working dogs (MWDs) with limited or no exposure to the same environment. In the second part of the study, results of a commercially available, human-blood lead testing system were compared with those of a benchtop inductively coupled plasma-mass spectrometry (ICP-MS) analysis technique. Blood samples from 18 MPCs were tested during routine clinical blood draws, and six samples from a canine group with limited exposure to environmental lead (nontactical MWDs) were tested for comparison. There was a high correlation between results of the commercial blood-testing system compared with ICP-MS when blood lead levels were higher than 4.0µg/dL. Both testing methods recorded higher blood lead levels in the MPC blood samples than in those of the nontactical MWDs, although none of the MPC samples tested contained lead levels approaching those at which symptoms of lead toxicity have previously been reported in animals (i.e., 35µg/dL). 2018.

  10. The Comparative Performance of Batteries: The Lead-Acid and the Aluminum-Air Cells.

    Science.gov (United States)

    LeRoux, Xavier; And Others

    1996-01-01

    Describes a teaching program that shows how electrochemical principles can be conveyed by means of hands-on experiences of student-centered teaching experiments. Employs the readily available lead-acid cell and the simple aluminum-air cell. Discusses the batteries, equilibrium cell potential, performance comparison, current, electrode separation,…

  11. Microstructure and wear behaviour of aluminium alloys containing embedded nanoscaled lead dispersoids

    International Nuclear Information System (INIS)

    Bhattacharya, Victoria; Chattopadhyay, K.

    2004-01-01

    We report the early stage friction and wear characteristics of aluminium containing nanosized lead dispersions. The nanocomposite was produced by rapid solidification. The experimental results indicate a significant decrease in friction and wear rate in comparison to its coarse grained counterparts. We show that the observed results suggest an adhesive type of wear mechanism. However, increase in hardness due to refinement of the aluminium grains cannot quantitatively rationalize the results. We explore and discuss the role of nanoscaled lead particles and the mass transport between the sample and counterface via mechanical alloying, in the formation of tribolayers affecting the tribological properties. The plane view and cross-sectional transmission electron microscopy reveals significant elongation as well as coarsening of the lead particles during the process of wear. We attempt to understand these results in the framework of moving dislocations and their assistance to the mass transport among the dispersed lead particles

  12. Lead Level in Pregnant Women Suffering from Pre- Ec-lampsia in Baghdad City- Iraq

    Directory of Open Access Journals (Sweden)

    Assala G. H. Al-Shammery

    2018-04-01

    Full Text Available This study was conducted on the number of pregnant women suffering from symptoms of preeclampsia who live in different areas in Baghdad city. These areas were suffering from air pol-lution by different pollutants in high rates and it was chosen from among these pollutants lead metal which is a high percentage of air pollution where it was observed by measuring the level of lead in blood serum which taken from pregnant women by 40 pregnant women suffering from symptoms of preeclampsia and 20 pregnant women don't suffering from any abnormal symptoms during pregnancy period and classified as control group , so we found marked a significant rise in lead level in comparison with control group reaching ratio of lead in blood of pregnant women which suffering from symptoms of preeclampsia 38.44 mg/dl ± 3.0 mg/dl in comparison with con-trol group which 14.56 mg/d l± 2.50 mg/dl,this increase may refer to the amount of lead which found in the air and in excess of the normal limit which exposed pregnant women like all people through the overcrowding of roads and use fuel non-environmentally friendly through breathing which effect on pregnant women health, it has been shown on symptoms of preeclampsia from measuring systolic and diastolic blood pressure and measuring of urea in blood, T-test was used at possibility of(0.001to see the difference between infected samples and control group, therefore this study suggested that a lead is one of the causes of preeclampsia because live in polluted and unhealthy environment. (pt space line

  13. Influence of residual elements in lead on oxygen- and hydrogen-gassing rates of lead-acid batteries

    Science.gov (United States)

    Lam, L. T.; Ceylan, H.; Haigh, N. P.; Lwin, T.; Rand, D. A. J.

    Raw lead materials contain many residual elements. With respect to setting 'safe' levels for these elements, each country has its own standard, but the majority of the present specifications for the lead used to prepare battery oxide apply to flooded batteries that employ antimonial grids. In these batteries, the antimony in the positive and negative grids dominates gassing characteristics so that the influence of residual elements is of little importance. This is, however, not the case for valve-regulated lead-acid (VRLA) batteries, which use antimony-free grids and less sulfuric acid solution. Thus, it is necessary to specify 'acceptable' levels of residual elements for the production of VRLA batteries. In this study, 17 elements are examined, namely: antimony, arsenic, bismuth, cadmium, chromium, cobalt, copper, germanium, iron, manganese, nickel, selenium, silver, tellurium, thallium, tin, and zinc. The following strategy has been formulated to determine the acceptable levels: (i) selection of a control oxide; (ii) determination of critical float, hydrogen and oxygen currents; (iii) establishment of a screening plan for the elements; (iv) development of a statistical method for analysis of the experimental results. The critical values of the float, hydrogen and oxygen currents are calculated from a field survey of battery failure data. The values serve as a base-line for comparison with the corresponding measured currents from cells using positive and negative plates produced either from the control oxide or from oxide doped with different levels of the 17 elements in combination. The latter levels are determined by means of a screening plan which is based on the Plackett-Burman experimental design. Following this systematic and thorough exercise, two specifications are proposed for the purity of the lead to be used in oxide production for VRLA technology.

  14. Increased bone calcium dissociation in lead-exposed rats

    Directory of Open Access Journals (Sweden)

    Eko Suhartono

    2012-12-01

    Full Text Available Background Lead is still a major environmental and occupational health hazard, since it is extensively used in the production of paints, gasoline and cosmetics. This causes the metal to be ubiquitous in the environment, being found in the air, soil, and water, from which it can enter the human body by inhalation or ingestion. Absorbed lead is capable of altering the calcium levels in bone. The aim of this study was to demonstrate the effect of lead on bone calcium levels by measuring the reaction constant, Gibbs free energy, and enthalpy. Methods This study was of pure experimental design using 100 male albino rats (Rattus norvegicus. The experimental animals were assigned by simple randomization to two groups, one group receiving lead acetate orally at a dosage of 100 mg/kgBW, while the other group did not receive lead acetate. The intervention was given for 4 weeks and the rats were observed weekly for measurement of bone calcium levels by the permanganometric method. Results This study found that k1 (hydroxyapatite dissociation rate constant was 0.90 x 10-3 dt-1, and that k2 (hydroxyapatite association rate constant was 6.16 x 10-3 dt-1 for the control group, whereas for the intervention group k1 = 26.20 x 10-3 dt-1 and k2 = 16.75 x 10-3 dt-1. Thermodynamically, the overall reaction was endergonic and endothermic (DG > 0 and DH > 0. ConclusionS Lead exposure results in increased dissociation rate of bone in comparison with its association rate. Overall, the reaction was endergonic and endothermic (DG > 0 and DH > 0.

  15. Increased bone calcium dissociation in lead-exposed rats

    Directory of Open Access Journals (Sweden)

    Eko Suhartono

    2015-12-01

    Full Text Available BACKGROUND Lead is still a major environmental and occupational health hazard, since it is extensively used in the production of paints, gasoline and cosmetics. This causes the metal to be ubiquitous in the environment, being found in the air, soil, and water, from which it can enter the human body by inhalation or ingestion. Absorbed lead is capable of altering the calcium levels in bone. The aim of this study was to demonstrate the effect of lead on bone calcium levels by measuring the reaction constant, Gibbs free energy, and enthalpy. METHODS This study was of pure experimental design using 100 male albino rats (Rattus norvegicus. The experimental animals were assigned by simple randomization to two groups, one group receiving lead acetate orally at a dosage of 100 mg/ kgBW, while the other group did not receive lead acetate. The intervention was given for 4 weeks and the rats were observed weekly for measurement of bone calcium levels by the permanganometric method. RESULTS This study found that k1 (hydroxyapatite dissociation rate constant was 0.90 x 10-3 dt-1, and that k2 (hydroxyapatite association rate constant was 6.16 x 10-3 dt-1 for the control group, whereas for the intervention group k1 = 26.20 x 10-3 dt-1 and k2 = 16.75 x 10-3 dt-1. Thermodynamically, the overall reaction was endergonic and endothermic (ΔG > 0 and ΔH > 0. CONCLUSIONS Lead exposure results in increased dissociation rate of bone in comparison with its association rate. Overall, the reaction was endergonic and endothermic (ΔG > 0 and ΔH > 0.

  16. Música e imágenes hasta la llegada del cine. (Linterna mágica, armónica de cristal, fantasmagorías y teatro de sombras

    Directory of Open Access Journals (Sweden)

    Armell Femenía, Montserrat

    2003-12-01

    Full Text Available The prehistory of talking movies where the coordination of moving images and sound is concerned, comprises a very extensive period of time of thousands of years stretching from the musical illustration of projected shadows as documented in Ancient China, up to practically the very dawn of cinematography, a technological advance unthinkable today more than ever without the contribution that music and sound have made to the so-called seventh art. This study sets out to offer an overall view of the history of continued human interest in capturing movement in sound and vision at the same moment in time, paying particular attention to certain technical achievements of some relevance (the magic lantern, the harmonic crystal, phantasmagories and the theatre of shadows within the evolution that was to facilitate the birth of the "talkies". A simple introduction to a fascinating and modern world, that, from a purely musicological view is practically nonexistent today (the meagre and marginal bibliography available is the best evidence of that and which requires new and more detailed studies to be done.

    La "pre-historia" del cine hablado, en lo relativo a la coordinación de imágenes en movimiento y sonido, supone un período extensísimo de tiempo, que abarca miles de años, desde la ilustración sonora de sombras proyectadas documentada en la antigua China, hasta prácticamente los albores del cinematógrafo, un avance tecnológico impensable —hoy en día más que nunca— sin la aportación que música y sonido han hecho al denominado séptimo arte. El presente trabajo pretende ofrecer una panorámica de la historia de la —documentadamente inconexa, aunque continua— preocupación humana por fijar el movimiento de un modo visual y sonoro a un tiempo, prestando particular atención a algunos logros técnicos de especial relevancia (la linterna mágica, la armónica de cristal, las fantasmagorías, el teatro de sombras, dentro del recorrido

  17. 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.

  18. Relative effects of climate and source strength on atmospheric lead concentrations in Auckland, New Zealand

    Science.gov (United States)

    Power, H. C.; de Freitas, C. R.; Hay, J. E.

    1992-06-01

    Atmospheric lead levels were examined to assess the consequences of the 46 percent reduction in the lead content of premium grade petrol in New Zealand. Since this change was implemented in July 1986 observed levels of atmospheric lead decreased by 38 percent, but all or part of this reduction may have been due to factors other than fluctuations in lead emissions, notably variations in climate. Analysis of detailed atmospheric lead, meteorological and traffic data measured contemporaneously provided insight into the atmospheric processes influencing lead levels in Auckland and formed the basis of a statistical model capable of predicting monthly lead concentrations. The model was used to predict lead levels in Auckland for the period July 1986 through to July 1989 in the absence of any reduction in the lead content of petrol. Comparison with values observed for the same period showed that all of the reduction in atmospheric lead levels since July 1986 can be attributed to the reduction in the lead content of petrol. Policy planning implications of such a finding are considered.

  19. Local polar fluctuations in lead halide perovskites

    Science.gov (United States)

    Tan, Liang; Yaffe, Omer; Guo, Yinsheng; Brus, Louis; Rappe, Andrew; Egger, David; Kronik, Leeor

    The lead halide perovskites have recently attracted much attention because of their large and growing photovoltaic power conversion efficiencies. However, questions remain regarding the temporal and spatial correlations of the structural fluctuations, their atomistic nature, and how they affect electronic and photovoltaic properties. To address these questions, we have performed a combined ab initio molecular dynamics (MD) and density functional theory (DFT) study on CsPbBr3. We have observed prevalent anharmonic motion in our MD trajectories, with local polar fluctuations involving head-to-head motion of A-site Cs cations coupled with Br window opening. We calculate Raman spectra from the polarizability auto-correlation functions obtained from these trajectories and show that anharmonic A-site cation motion manifests as a broad central peak in the Raman spectrum, which increases in intensity with temperature. A comparison of the experimental Raman spectrum of hybrid organometallic MAPbBr3 and fully inorganic CsPbBr3 suggests that structural fluctuations in lead-halide perovskites is more general than rotation of polar organic cations and is intimately coupled to the inorganic framework.

  20. Enhanced bioremoval of lead by earthworm-Lumbricus terrestris co-cultivated with bacteria-Klebsiella variicola.

    Science.gov (United States)

    Das, Anamika; Osborne, Jabez W

    2017-10-01

    Lead is a toxic heavy metal having devastating effects on the environment. The current study was focussed on bioremoval of lead using earthworm and lead resistant bacteria. Earthworms were subjected to various concentrations of lead in the soil bioaugmented with lead resistant bacteria (VITMVCJ1) to enhance the uptake of lead from the contaminated soil. Significant increase was observed in the length and body weight of the earthworms supplemented with lead resistant bacteria. Similarly, there was a substantial increase in the locomotion rate of the earthworms treated with lead resistant bacteria in comparison with the control. The gut micro flora of bacterial treated earthworms had increased number of bacterial cells than the untreated earthworms. The histopathological studies revealed the toxic effects of lead on the gut of earthworms indicating severe damage in lead resistant bacteria untreated worms, whereas the cells were intact in lead resistant bacteria treated worms. COMET assay showed increased DNA damage with higher tail DNA percent in the untreated earthworms. Further, the colonisation of the bacteria supplemented, onto the gut region of earthworms was observed by scanning electron microscopy. Atomic absorption spectrophotometry indicated a fair 50% uptake of lead within the biomass of earthworm treated with lead resistant bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Isotopic geochronology of granitic rocks from the Central Iberian Zone: comparison of methodologies

    Directory of Open Access Journals (Sweden)

    Antunes, I. M.H.R.

    2010-06-01

    Full Text Available Five granitic rocks, concentrically disposed from core to rim, were distinguished in the Castelo Branco pluton. U-Pb-Th electron microprobe monazite ages from granitic rocks are similar and ranging between 297-303 Ma. The granitic rocks from Castelo Branco pluton are 310 ± 1 Ma old, obtained by U-Pb (ID-TIMS in separated zircon and monazite crystals, indicating a similar emplacement age for all granitic rocks of the pluton. Initial 87Sr/86Sr isotopic ratios and epsilon-Nd310 and delta-18O values suggest three distinct pulses of granitic magma and that they are derived from partial melting of heterogeneous metasedimentary materials. The other granitic rocks are related by magmatic differentiation and show small variations in (87Sr/86Sr310, epsilon-Nd310 and delta-18O. The granitic pluton of Castelo Branco shows a rare reverse zoning.

    En el plutón de Castelo Branco, se distinguen cinco granitoides, dispuestos concéntricamente de núcleo a borde del plutón. Las edades U-Pb-Th obtenidas en cristales de monacita por microsonda electrónica en estos granitoides son similares entre sí y varían entre 297 y 303 Ma. Los resultados de datación por U-Pb (ID-TIMS en cristales de circón y de monacita de los tres granitos seleccionados, indican una edad de implantación de 310 ± 1 Ma y que son rocas emplazadas simultáneamente. Las relaciones isotópicas iniciales de 87Sr/86Sr y los valores de epsilon-Nd310 y delta-18O de los tres pulsos magmáticos son característicos de granitos resultantes de anatexia cortical a partir de rocas metasedimentarias heterogéneas. En la secuencia de diferenciación magmática, las rocas graníticas presentan pequeñas variaciones en (87Sr/86Sr310, epsilon-Nd310 y delta-18O. El plutón de Castelo Branco presenta un

  2. Distribution of lead in relation to size of airborne particulate matter in Islamabad, Pakistan.

    Science.gov (United States)

    Shah, Munir H; Shaheen, N; Jaffar, M; Saqib, M

    2004-02-01

    Airborne particulate matter (PM) collected from two sampling stations in Islamabad, Pakistan, was analyzed for lead content and size gradation. A high volume air sampler was used to trap particulates on glass fiber filters for 8-12 h on a daily basis. Lead was estimated using a nitric acid digestion based AAS method on 44 samples from station 1 and 61 samples from station 2. Particle size fractions were categorized as 100 microm. The correlation between lead concentration and particle size was investigated. The results from two stations indicated average airborne lead concentrations of 0.505 and 0.185 microg/m3. Enhanced levels of lead were measured at a maximum of 4.075 microg/m3 at station 1 and 4.000 microg/m3 at station 2. PM 100 were found to constitute the local atmosphere in comparable proportions. A comparison of the lead levels is made with the existing permissible levels of this element laid down by different international agencies.

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

    International Nuclear Information System (INIS)

    Kasperczyk, Aleksandra; Kasperczyk, Slawomir; Horak, Stanislaw; Ostalowska, Alina; Grucka-Mamczar, Ewa; Romuk, Ewa; Olejek, Anita; Birkner, Ewa

    2008-01-01

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

  4. Lead pollution: effects on chlorophyll. [Phalaris canariensis, Lemna minor, graminaceae

    Energy Technology Data Exchange (ETDEWEB)

    Fiussello, N

    1973-01-01

    The emissions of motors are responsible for the high concentrations of lead in soil and plants near roads. In man, when the concentration of lead in blood exceeds the value of 30 ..mu..g/100 ml, is shown a decrease of haemaglobin and an increase of ALA urinary content. Since the early stages of chlorophyll biosynthetic pathway are similar if not identical with those leading to haem as far as protoporphyrin IX, it is interesting to ascertain if lead can specifically interfere in chlorophyll biosynthesis. In sand cultures with 200 p.p.m. of lead (the conc. in roadside soils), after 2 weeks, wheat shows a diminution of 16,5% in fresh weight 7,5% in dry weight and 6,5% in chlorophyll; Phalaris canariensis shows a diminution of 68% f.w., 41% d.w. and 39% chl. in comparison with the controls. A water-plant, Lemna minor, is more sensitive: the chlorophyll content, referred to dry weight, shows after a week a diminution of 32% and 55% with 10/sup -4/M and 10/sup -3/M lead nitrate. Lead in 200 p.p.m. conc. is surely poisonous against the tested plants but a specific action on chlorophyll synthesis could be accepted, at present, only for Lemna minor. It is possible that in wheat and in Phalaris a part of lead is bound in root-system, the more damaged, while in Lemna it can reach more easily the chloroplasts. At present a detectable increase of ALA, in plants treated with lead, has not been proved both in Graminaceae and in Lemna minor.

  5. Dosimetry of small electron fields shaped by lead

    International Nuclear Information System (INIS)

    Perez, M.; Hill, R.; Whitaker, M.; Greig, L.; West, M.; Jones, L.

    2000-01-01

    Full text: Electron fields can be used to treat superficial cancers. Field shaping can be achieved by placing lead on the patient surface to minimise the dose to surrounding areas and may improve beam penumbra compared to using standard applicators. However, significant dosimetry changes under high density material edges for electron fields have been reported (W Pohlit and KH Manegold, cited in The Physics of Radiation Therapy, P.M. Khan, 1994). This project evaluated the dosimetry of small dimension electron fields shaped with lead placed on the surface. Comparisons were made between circular lead cutouts (3 and 5cm diameters) and an open electron applicator (5cm diameter). For each of these fields depth doses and profiles were measured using a diode detector in a water phantom, and isodoses were measured using X-Omat film sandwiched within a Solid water phantom. Output factors were measured in the Solid water using a Markus parallel plate ionisation chamber. The effect of the lead thickness on the profiles and output was quantified and the thickness used for the final measurements selected so as to give less than 5% transmission of the primary dose. Penumbral widths for 6MeV and 8MeV using the lead cutouts showed distinct differences compared with the open applicator. At depths of the 90% relative dose the profiles for lead shaped fields showed tighter penumbra widths by an average of 2 mm. This became more pronounced nearer the surface where, at 2mm depth, the difference in penumbral widths was an average of 4mm. The 3cm lead cutouts showed surface dose increases of 6% and 9% for 6MeV and 8 MeV respectively. Depth dose parameters (D max and R 90 ) varied by no more than 2mm between the lead cutouts and the open applicator measurements. Lead can be used to shape electron fields for radiotherapy treatments. Depth dose characteristics do not vary significantly with a 5 cm circular applicator. The penumbral width indicates less isodose spread for the lead cutout

  6. Measurement Of Lead Equivalent Thickness For Irradiation Room: An Analysis

    International Nuclear Information System (INIS)

    Mohd Khalid Matori; Azuhar Ripin; Husaini Salleh; Mohd Khairusalih Mohd Zin; Muhammad Jamal Muhd Isa; Mohd Faizal Abdul Rahman

    2014-01-01

    The Malaysian Ministry of Health (MOH) has established that the irradiation room must have a sufficient thickness of shielding to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for irradiation room at health clinics own by MOH. Results of measurement of 8 irradiation rooms conducted in 2014 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that almost all the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

  7. Performance of Dower's inverse transform and Frank lead system for Identification of Myocardial Infarction.

    Science.gov (United States)

    Aranda, A; Bonizzi, P; Karel, J; Peeters, R

    2015-08-01

    This study performs a comparison between Dower's inverse transform and Frank lead system for Myocardial Infarction (MI) identification. We have selected a set of relevant features for MI detection from the vectorcardiogram and used the lasso method after that to build a model for the Dower's inverse transform and one for the Frank leads system. Then we analyzed the performance between both models on MI detection. The proposed methods have been tested using PhysioNet PTB database that contains 550 records from which 368 are MIs. Two main conclusions are coming from this study. The first one is that Dower's inverse transform performs equally well than Frank leads in identification of MI patients. The second one is that lead positions have a large influence on the accuracy of MI patient identification.

  8. Facebook and self-perception: individual susceptibility to negative social comparison on Facebook

    NARCIS (Netherlands)

    de Vries, D.A.; Kühne, R.

    2015-01-01

    Social network sites such as Facebook give off the impression that others are doing better than we are. As a result, the use of these sites may lead to negative social comparison (i.e., feeling like others are doing better than oneself). According to social comparison theory, such negative social

  9. 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.

  10. Calculation of the electronic structure optical transitions and contact hyperfine parameters of interstitial hydrogen in alkaline halogen crystals

    International Nuclear Information System (INIS)

    Maciel, A.K.A.

    1977-03-01

    The electronic structure of the interstitial hydrogen atom in KF, NaCl, KCl, and RbCl cristals has been studied using the self-consistent-field multiple-scattering Xα method. In the present calculation a cluster constituted by the hydrogen atom surrounded by its first anion and cation neighbors in a cubic shell has been used. The optical transition energies and hyperfine contact parameters with the interstitial proton and the first shell nuclei have been evaluated. The agreement obtained with the experimental data and the relative independence of the method under variations of its intrinsic parameters, indicate that this method can be adequate to the study of defects in ionic cristals. (author) [pt

  11. Comparison of blood lead levels of mothers and cord blood in intrauterine growth retarded neonates and normal term neonates

    International Nuclear Information System (INIS)

    Iranpour, R.; Besharati, Amir A.; Nasseri, F.; Hashemipour, M.; Kelishadi, R.; Balali-Mood, M.

    2007-01-01

    Objective was to compare the blood lead levels of mothers and cord blood in intrauterine growth retarded (IUGR) neonates and normal term neonates. From April 2005, we carried out a cross-sectional, prospective study in Isfahan University of Medical Sciences, Isfahan, Iran. Blood lead levels were measured in the umbilical cord and maternal venous blood samples in the 32 mother-infant pairs with IUGR full term neonates and 34 mother-infant pairs with normal full term neonates. Blood-lead levels were analyzed by atomic absorption spectrometry. The mean lead concentration in neonates of IUGR and normal groups was not significantly different (107.47+- 16.75 versus 113.08+-19.08 ug/L, p=0.2). The mean lead concentration in mothers of IUGR group was lower than normal groups, but this difference was not significant (124.56+-19.71 versus 135.26+-26.91 ug/L, p=0.07). Maternal lead levels were strongly related with related with cord blood in both IUGR and normal groups (r=0.8, p 100ug/L by the centers for disease control; however, this was not statistically different between the groups. Our results indicate that the mean lead level was not higher in IUGR neonates, and the whole blood lead was not related to the birth weight. In addition, maternal and cord blood lead levels were strongly correlated, and there were remarkable lead burdens on both the mothers and their neonates in this industrial area. (author)

  12. 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.

  13. First detection of lead in black paper from intraoral film

    International Nuclear Information System (INIS)

    Guedes, Debora F.C.; Silva, Reginaldo S.; Veiga, Marcia A.M.S. da; Pecora, Jesus D.

    2009-01-01

    Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirao Preto, University of Sao Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 μg g -1 , 189 μg g -1 , 20.8 μg g -1 , and 54.0 μg g -1 , respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise.

  14. Comparison of lead and sodium-cooled reactors - Safety, fuel cycle performance and some economical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Johan; Tucek, Kamil; Wider, Hartmut [Joint Research Centre, EC-JRC, Westerduinweg 3, P.O. Box 2, NL-0 1755 ZG Petten (Netherlands)

    2006-07-01

    This paper compares the Lead-cooled Fast Reactor (LFR) and the Sodium-cooled Fast Reactor (SFR) regarding different aspects of the coolant, safety and economics. A brief review of design and safety experience of an SFR (BN-600) and some safety philosophy of the most developed LFR (BREST) are presented as well. The pros and cons of the lead and the sodium coolants are discussed. This paper presents results concerning the coolant temperature evolution during three accident scenarios, i.e. Loss-Of- Flow (LOF), Loss-Of-Heat-Sink (LOHS), and Total-Loss-Of-Power (TLOP). It also studies possible moderators, like BeO and hydrides, for the core designs to have negative reactivity feedbacks and favorable reactivity swings. LFR seems to be able to accommodate more minor actinides than SFR at comparable coolant and Doppler feedbacks. We show that LFR can be designed both to breed and burn transuranics from LWRs. The hydrides lead to the most favorable reactivity feedbacks, but the poorest reactivity swing. It is shown that the LFR can handle the LOF transient better than the SFR. This is due to the much lower pressure drop in the LFR core. The coolant outlet temperatures stabilize at 2050 K and 940 K for SFR and LFR, respectively when no feedbacks are considered. Investigations also concern the SFR's performance when the pitch-to-diameter was increased from 1.2 to 1.4. For the LOHS and TLOP accidents their temperature evolutions are milder for the LFR since lead has a 50% larger volumetric heat capacity. For the TLOP the core outlet temperature of the LFR peaks at 1080 K after 2 days. Regarding economics it appears easier to avoid an intermediate cycle in an LFR than an SFR. (authors)

  15. Comparison of lead and sodium-cooled reactors - Safety, fuel cycle performance and some economical aspects

    International Nuclear Information System (INIS)

    Carlsson, Johan; Tucek, Kamil; Wider, Hartmut

    2006-01-01

    This paper compares the Lead-cooled Fast Reactor (LFR) and the Sodium-cooled Fast Reactor (SFR) regarding different aspects of the coolant, safety and economics. A brief review of design and safety experience of an SFR (BN-600) and some safety philosophy of the most developed LFR (BREST) are presented as well. The pros and cons of the lead and the sodium coolants are discussed. This paper presents results concerning the coolant temperature evolution during three accident scenarios, i.e. Loss-Of- Flow (LOF), Loss-Of-Heat-Sink (LOHS), and Total-Loss-Of-Power (TLOP). It also studies possible moderators, like BeO and hydrides, for the core designs to have negative reactivity feedbacks and favorable reactivity swings. LFR seems to be able to accommodate more minor actinides than SFR at comparable coolant and Doppler feedbacks. We show that LFR can be designed both to breed and burn transuranics from LWRs. The hydrides lead to the most favorable reactivity feedbacks, but the poorest reactivity swing. It is shown that the LFR can handle the LOF transient better than the SFR. This is due to the much lower pressure drop in the LFR core. The coolant outlet temperatures stabilize at 2050 K and 940 K for SFR and LFR, respectively when no feedbacks are considered. Investigations also concern the SFR's performance when the pitch-to-diameter was increased from 1.2 to 1.4. For the LOHS and TLOP accidents their temperature evolutions are milder for the LFR since lead has a 50% larger volumetric heat capacity. For the TLOP the core outlet temperature of the LFR peaks at 1080 K after 2 days. Regarding economics it appears easier to avoid an intermediate cycle in an LFR than an SFR. (authors)

  16. 'Do lead rubber aprons pose an infection risk?'

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, Helen [Diagnostic Radiographer, Queen Elizabeth Hospital, Kings Lynn NHS Trust (United Kingdom); Strudwick, Ruth M., E-mail: r.strudwick@ucs.ac.u [School of Health, Science and Social Care, University Campus Suffolk, IP4 1QJ (United Kingdom)

    2010-11-15

    This study was carried out in order to establish whether infection control measures were being undertaken sufficiently on lead rubber aprons within a diagnostic imaging department in the east of England. This study involved the swabbing of a sample of 15 lead rubber aprons used within different areas of the department. Swabs were taken from the area on the underside of the shoulders and from the front of the apron. Each apron was firstly swabbed to determine the current level of microorganism contamination (determination of baseline data) and then again after recommended cleaning with detergent and water (the production of a standard). Comparisons were then made between the number of microorganisms' present (colony forming units/cm{sup 2}) pre and post-cleaning at each location. Additionally, post-cleaning data was compared for each location. All aprons were found to be contaminated with microorganisms, those identified were Coagulase-negative staphylococci, Staphylococcus aureus, Bacillus, Diphtheroids and some fungal spores. No Methicillin resistant strains of Staphylococcus aureus (MRSA) were identified. Recommended cleaning with detergent and water was found to significantly reduce the amount of microorganisms present (the detergent used was Hospec general purpose neutral liquid detergent). Comparisons of the sample sites found that the front of the apron had lower levels of microorganism contamination post-cleaning than the site at the underside of the shoulders. The results suggest that the lead rubber aprons were not being cleaned sufficiently which has infection control implications for the department. In order for cross contamination to be kept to a minimum an effective infection control policy needs to be employed and this should be to carry out regular cleaning with detergent and water which has been shown can significantly reduce contamination.

  17. Comparison of three jet events to predictions from a next-to-leading order calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Alexander [Univ. of New Mexico, Albuquerque, NM (United States)

    2002-01-01

    The properties of three-jet events in data of integrated luminosity 86±4 pb-1 from CDF Run 1b and with total transverse energy greater than 175 GeV have been analyzed and compared to predictions from a next-to-leading order perturbative QCD calculation.

  18. The Effect of Lead Intensification Screens on Film: Modeling and Experiment

    International Nuclear Information System (INIS)

    Wendt, S.; Gray, J.; Zhou, C.

    2004-01-01

    A physics-based, intensification screen model, using lead as an example, has been developed. Comparisons to experimental results are shown. The dominant effect in producing the intensification is from photoelectrons ejected from a 24 - 40 micron layer of lead near the film with Compton electrons and the lead fluorescence x-rays contributing less than 10% to the intensification for settings below 300 kvp. The thickness of lead screen for optimal intensification is between 15 and 70 microns depending upon the energy of the photon. This is less than the traditional practice of a 130 microns front screen and 260 microns back screen. The model computes the intensifying effect of lead screens placed in front or in back of a sheet of radiographic film and accounts for the strong energy dependent effects contributing to the intensification. The lead screen model is independent of film type, so the user can select any type of film and any combination of lead thickness for the front and back screens. The model uses energy dependent x-ray photon absorption cross-sections to compute the production of electrons in the lead. A Monte Carlo calculation was used to determine energy dependent electron penetration in the lead and the film. The model calculates electron attenuation in the film emulsion, the film substrate and both front and back lead screens and determines the intensification effect as a function of the energy deposited in the film. For model validation, lead screen intensification was studied with x-ray generator settings ranging from 75 to 320 kvp and using various thicknesses of aluminum and iron attenuators to filter the x-ray beam. A high precision motion control system coupled with a high purity germanium detector was used to study the energy spectra

  19. Erythrocyte hemolysis by organic tin and lead compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kleszcynska, H. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Hladyszowski, J. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Pruchnik, H. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Przestalski, S. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics

    1997-01-01

    The effect of trialkyllead and trialkyltin on pig erythrocyte hemolysis has been studied and compared. The results of experiments showed that the hemolytic activity of organoleads increases with their hydrophobicity and follows the sequence: triethyllead chloride < tri-n-propyllead chloride < tributyllead chloride. And similarly in the case of organotins: triethyltin chloride < tri-n-propyltin chloride < tributyltin chloride. Comparison of the hemolytic activity of organoleads and organotins indicates that the lead compounds exhibit higher hemolytic activity. The methods of quantum chemistry allowed to determine the maximum electric potential of the ions R{sub 3}Pb{sup +} and R{sub 3}Sn{sup +}, and suggest a relationship between the potential and toxicity. (orig.)

  20. Effect of lead exposure on the immune response of some occupationally exposed individuals

    International Nuclear Information System (INIS)

    Mishra, Kamla Prasad; Singh, Vijay Kumar; Rani, Reena; Yadav, Virendra Singh; Chandran, Vinod; Srivastava, Satya Prakash; Seth, Prahlad Kishore

    2003-01-01

    Lead is a ubiquitous pollutant in the industrial environment, which poses serious threats to human health. In the past 20 years increasing attention has been paid to the effects of lead exposure on health. This toxic metal alters the immune response of animals as well as humans. To study the immunological effects of occupational exposure to lead, we examined lymphocyte proliferation, natural killer (NK) cell cytotoxicity and interferon-γ production with peripheral blood mononuclear cells (PBMCs) of individuals occupationally exposed to lead. We selected three different groups of individuals exposed to lead: three-wheeler drivers (30), battery workers (34) and silver jewelery makers (20); and unexposed healthy volunteers (30) as control for comparison. Our results indicate that though lymphocyte proliferation to phytohaemagglutinin (PHA) is inhibited in lead exposed individuals as compared with unexposed volunteers, there is no correlation between inhibition of lymphocyte proliferation and blood lead level. NK cell cytotoxicity remains unaffected in individuals exposed to lead as compared with controls. On the other hand, we observed that interferon-γ (IFN-γ) was significantly elevated in T cell mitogen, PHA, stimulated PBMCs culture supernatant of lead exposed individuals. We found significant positive correlation between blood lead levels and IFN-γ produced in culture supernatant on stimulation with PHA. In brief, this study demonstrates that lead can affect the immune response of the occupationally exposed individuals such as three-wheeler drivers, battery reconditioning workers and silver jewelery makers

  1. Fuzzy Control Model and Simulation for Nonlinear Supply Chain System with Lead Times

    Directory of Open Access Journals (Sweden)

    Songtao Zhang

    2017-01-01

    Full Text Available A new fuzzy robust control strategy for the nonlinear supply chain system in the presence of lead times is proposed. Based on Takagi-Sugeno fuzzy control system, the fuzzy control model of the nonlinear supply chain system with lead times is constructed. Additionally, we design a fuzzy robust H∞ control strategy taking the definition of maximal overlapped-rules group into consideration to restrain the impacts such as those caused by lead times, switching actions among submodels, and customers’ stochastic demands. This control strategy can not only guarantee that the nonlinear supply chain system is robustly asymptotically stable but also realize soft switching among subsystems of the nonlinear supply chain to make the less fluctuation of the system variables by introducing the membership function of fuzzy system. The comparisons between the proposed fuzzy robust H∞ control strategy and the robust H∞ control strategy are finally illustrated through numerical simulations on a two-stage nonlinear supply chain with lead times.

  2. Criticality of mixtures of plutonium and high enriched uranium

    International Nuclear Information System (INIS)

    Grolleau, E.; Lein, M.; Leka, G.; Maidou, B.; Klenov, P.

    2003-01-01

    This paper presents a criticality evaluation of moderated homogeneous plutonium-uranium mixtures. The fissile media studied are homogeneous mixtures of plutonium and high enriched uranium in two chemical forms: aqueous mixtures of metal and mixtures of nitrate solutions. The enrichment of uranium considered are 93.2wt.% 235 U and 100wt.% 235 U. The 240 Pu content in plutonium varies from 0wt.% 240 Pu to 12wt.% 240 Pu. The critical parameters (radii and masses of a 20 cm water reflected sphere) are calculated with the French criticality safety package CRISTAL V0. The comparison of the calculated critical parameters as a function of the moderator-to-fuel atomic ratio shows significant ranges in which high enriched uranium systems, as well as plutonium-uranium mixtures, are more reactive than plutonium systems. (author)

  3. Misleading Comparisons between Chernobyl and Fukushima

    International Nuclear Information System (INIS)

    Hiranuma, Yuri

    2016-01-01

    This paper critically analyzes illogical and often misleading comparisons between Fukushima and Chernobyl where the nuclear accidents have occurred. A letter by Takamura et al. published in The Lancet Diabetes and Endocrinology makes comparisons between the exposure doses and the age distributions of childhood thyroid cancer cases in Belarus and Fukushima. Estimated exposure doses in highly contaminated areas in Belarus were compared with potentially underestimated Fukushima doses. Age distributions of thyroid cancer cases are compared at different times after the accidents: after 4-5 years in Belarus vs. first 4 years in Fukushima. The absence of cancer cases in ages 0-5 at exposure in Fukushima in the first 4 years after the accident is not surprising because the supposed latency of childhood thyroid cancer is considered 4-5 years based on the Chernobyl experience. Yet this absence is claimed as a basis leading to a premature conclusion to dismiss radiation effects on thyroid cancer cases in Fukushima. Similar illogical comparisons made in Japan and overseas are discussed. A possibility of a shorter latency period is entertained based on a carcinogenic potential of ionizing radiation as initiator as well as promoter. Lastly, a pooled analysis of 12 studies on thyroid cancer after childhood external exposure (2016) is introduced as an evidence that exposure doses below 100 mGy lead to an increase in relative risk of thyroid cancer with a linear dose-response. (author)

  4. Comparison of different bonding techniques for efficient strain transfer using piezoelectric actuators

    Science.gov (United States)

    Ziss, Dorian; Martín-Sánchez, Javier; Lettner, Thomas; Halilovic, Alma; Trevisi, Giovanna; Trotta, Rinaldo; Rastelli, Armando; Stangl, Julian

    2017-04-01

    In this paper, strain transfer efficiencies from a single crystalline piezoelectric lead magnesium niobate-lead titanate substrate to a GaAs semiconductor membrane bonded on top are investigated using state-of-the-art x-ray diffraction (XRD) techniques and finite-element-method (FEM) simulations. Two different bonding techniques are studied, namely, gold-thermo-compression and polymer-based SU8 bonding. Our results show a much higher strain-transfer for the "soft" SU8 bonding in comparison to the "hard" bonding via gold-thermo-compression. A comparison between the XRD results and FEM simulations allows us to explain this unexpected result with the presence of complex interface structures between the different layers.

  5. How do you tell whether a change in surgical technique leads to a change in outcome?

    Science.gov (United States)

    Vickers, Andrew J; Cronin, Angel M; Masterson, Timothy A; Eastham, James A

    2010-04-01

    Surgeons routinely evaluate and modify their surgical technique to improve patient outcome. It is also common for surgeons to analyze results before and after a change in technique to determine whether the change led to better results. Simple comparison of results before and after surgical modification may be confounded by the surgical learning curve. We developed a statistical method applicable to analyzing before/after surgical studies. We used simulation studies to compare different statistical analyses of before/after studies. We evaluated a simple 2-group comparison of results before and after the modification by the chi-square test and a novel bootstrap method that adjusts for the surgical learning curve. In the presence of the learning curve a simple 2-group comparison almost always showed an ineffective surgical modification to be of benefit. When the surgical modification was harmful, leading to a 10% decrease in the success rate, 2-group comparison nonetheless showed a statistically significant improvement in outcome about 80% of the time. The bootstrap method had only moderate power but did not show that ineffective surgical modifications were beneficial more than would be expected by chance. Simplistic approaches to the analysis of before/after surgical studies may lead to grossly erroneous results under the surgical learning curve. A straightforward alternative statistical method allows investigators to separate the effects of the learning curve from those of the surgical modification. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  6. Ore-lead isotopes and Grenville plate tectonics

    International Nuclear Information System (INIS)

    Farquhar, R.M.; Fletcher, I.R.

    1980-01-01

    Recent advances in the 'whole earth' modelling of evolutionary processes of Pb isotopes shed light upon the origin of the metals found in various types of ore deposits. On the bases of these models and several recently published data sets, we believe that the ore deposits formed in various plate tectonic environments may carry 'isotopic fingerprints' which, when used with other characteristics such as mineral assemblages, may identify the depositional environments of many ore bodies. In the present study Pb-isotopic measurements have been made of a number of Precambrain mineralization types and localities throughout the Central Metasedimentary Belt of the Grenville Province. The data for individual deposits are at best ambiguous, but fall into two groups sufficiently distinctive to allow some degree of 'fingerprint' identification. Comparisons with data from other areas suggest that the major periods of sedimentation within the Central Metasedimentary Belt accompanied plate rifting and/or island arc tectonic activity, with most of the mineralized lead being derived from mantle sources. Detailed comparisons between the Grenville and other regions are uncertain, mainly because there are few detailed high-accuracy data sets from younger, tectonically unambiguous mineral occurrences. We suggest that once these data sets are availble, isotopic fingerprinting may become diagnostic for deposits ranging well back into the Precambrain

  7. The Chateau de Cristal data acquisition system

    International Nuclear Information System (INIS)

    Villard, M.M.

    1987-05-01

    This data acquisition system is built on several dedicated data transfer busses: ADC data readout through the FERA bus, parallel data processing in two VME crates. High data rates and selectivities are performed via this acquisition structure and new developed processing units. The system modularity allows various experiments with additional detectors

  8. A comparison of dose savings of lead and lightweight aprons for shielding of 99m-Technetium radiation

    International Nuclear Information System (INIS)

    Warren-Forward, H.; Cardew, P.; Smith, B.; Clack, L.; McWhirter, K.; Johnson, S.; Wessel, K.

    2007-01-01

    Nuclear medicine technologists (NMTs) have the highest effective doses of radiation among medical workers. With increase in the use of lightweight materials in diagnostic radiography, the aim was to compare the effectiveness of lead and lightweight aprons in shielding from 99m-Technetium ( 99m Tc) gamma rays. The doses received from a scattering phantom to the entrance, 9 cm depth and exit of a phantom were measured with LiF:Mg, Cu, P thermoluminescent dosemeters (TLDs). Doses and spectra were assessed without no shielding, with 0.5-mm lead and lightweight aprons. The lead and lightweight aprons decreased entrance surface doses by 76 and 59%, respectively. The spectral analysis showed that the lightweight apron provided better dose reduction at energies 99m Tc labelled radiopharmaceutical. (authors)

  9. Lead and mercury levels in an environmentally exposed population in the Central Brazil.

    Science.gov (United States)

    Jesus, Leda Diva Freitas de; Moreira, Maria de Fátima Ramos; Azevedo, Sayonara Vieira de; Borges, Renato Marçullo; Gomes, Regina Aderne de Almeida; Bergamini, Fernanda Pereira Baptista; Teixeira, Liliane Reis

    2018-03-01

    The objective was to assess the level of exposure to lead and mercury in a population in the Pantanal region in Mato Grosso State, Brazil. Blood lead (PbB) (n = 119) and urinary mercury (HgU) (n = 109) in local residents were measured by atomic absorption spectrometry. Comparison of means and correlations between variables used analysis of variance (ANOVA) and linear regression, respectively, with 95% confidence intervals. Mean PbB was 2.82 ± 1.53µg dL-1. The comparison of PbB stratified by collection site (p ≤ 0.01), work activity (p ≤ 0.01), and consumption of locally produced cow's milk (p ≤ 0.05) showed statistically significant differences. There were also positive associations between PbB and collection site (p ≤ 0.01), participants' profession (p ≤ 0.05), local milk (p ≤ 0.01), and source of drinking water (p ≤ 0.01). Mean HgU was 1.41 ± 0.98µg L-1. The levels only showed significant differences for participants' profession (p ≤ 0.01), and positive associations emerged between HgU and work activity (p ≤ 0.01) and body mass index (p ≤ 0.01). The samples showed low lead and mercury levels, similar to those found in other environmentally exposed populations. Despite these low concentrations, current knowledge on the toxicity of these metals shows that health effects can already be felt at levels that were previously considered safe, thus characterizing a health hazard.

  10. The effect of illegal lead processing on blood lead levels in children living in the mining area

    Directory of Open Access Journals (Sweden)

    Ćorac Aleksandar

    2017-01-01

    Full Text Available Backgraund/Aim. The northern part of Kosovo was one of the largest lead and zinc production industries in Europe. Special attention has been paid to the landfill sites of these metals remained after past industrial activities. The inhabitants of Roma camps in this area are collecting led waste they process by crushing and melting in their shacks in primitively organized working environments. Because of all the aforementioned it was necessary to examine the concentration of blood lead level (BLL in the children aged less than 6 years inhabiting this area, especially taking care of blood analysis of children living in Roma camps. Methods. The study was conducted in the municipality of Leposavić, Province Kosovo and Metohija, Serbia. Totally 78 subjects participated in the study. All the subjects were divided into two groups: the group I consisting of 42 children who lived in the Romas camp, and the group II with 36 children from a city kindergarten. Based on the mathematical model WRPLOT we found out that both groups of patients were in the low risk zone for industrial contamination exposure. Blood analysis was done according to the protocol provided by ESA Lead Care. Results. The average age of participants in the study was 4.60 ± 1.63 years. The mean BBL in the children from the group 1 was 19.11 μg/dL and from the group 2 4.87 μg/dL. There was a statistically significant difference in the mean values of BBL between the groups (U = 39, p < 0.001. All of the children from the group 1 had BBL greater than 5 μg/dL in comparison to 38.9% of the children from the group 2 (χ2 = 35.75, p < 0.001. Conclusion. Although both groups were located outside the zone of direct spread of pollution, the results indicate high concentrations of lead in blood of all the examined children. The concentration was higher in the children who lived in the area in which illegal processing of lead waste took place. [Project of the Serbian Ministry of Education

  11. Microscopic determination of leading terms of the interaction Hamiltonian between sd- and g-parts in the sdg IBM

    International Nuclear Information System (INIS)

    Zhang Zhanjun; Liu Yong; Sang Jianping

    1995-01-01

    Starting from one of the microscopic sdg interacting boson approximations, the leading terms in the interaction Hamiltonian are discussed by using numerical investigations. Comparisons of both the calculated levels and the overlap of wave functions between the exact results and the approximations are made to find out negligible part in the Hamiltonian. The results show that the leading terms given may provide a way to simplify the complex calculations

  12. The continuing impact of lead dust on children's blood lead: comparison of public and private properties in New Orleans.

    Science.gov (United States)

    Mielke, Howard W; Gonzales, Chris R; Mielke, Paul W

    2011-11-01

    Compared with a maximum collective lead (Pb) estimate of ∼1811 metric tons (MT) in exterior paint on 86,000 New Orleans houses, Pb additives in gasoline were estimated at ∼12,000 MT in New Orleans, yielding ∼9100 MT Pb exhausted as aerosols from vehicles; ∼4850 MT were particles>10 μm and ∼4200 MT were particles New Orleans. This study includes 224 soil samples from 10 public housing properties and 363 soil samples from residential private properties within an 800 m radius of centroids of public housing census tracts. The Louisiana Childhood Lead Poisoning Prevention Program data from 2000 to 2005 (pre-Hurricane Katrina) was the source for 9807 children's blood Pb (μg/dL) results. Soil and blood Pb data were grouped by public housing census tracts and private residential properties. This study uses Multi-Response Permutation Procedures for statistical analysis. Brick public properties in the city core had significantly more soil Pb contamination and higher prevalence of elevated children's blood Pb than same-aged brick public properties in the outer areas of the city. The pre-Hurricane Katrina New Orleans concentration of Pb dust in the inner-city soil displayed a median of 438 mg/kg or 3.7 times larger than Pb dust in outlying areas where the median soil Pb was 117 mg/kg (p-value=2.9×10(-15)). Also, the pre-Hurricane Katrina prevalence of children's blood Pb≥10 μg/dL was 22.9% within the inner-city compared with 9.1% in the outer areas of New Orleans (p-value=3.4×10(-74)). Comparing the quantities of Pb dust from paint and Pb additives to gasoline, this study supports the later source as a more plausible explanation for the differences in soil Pb and children's blood Pb within public and private housing in the higher traffic congested inner-city core compared with the lower traffic congested outer areas of New Orleans. Similar patterns of environmental Pb dust contamination and childhood Pb exposure are expected in all cities. Copyright © 2011

  13. A contribution to the structural and kinetic study of the slow transformation of an iron or uranium alpha crystal; Contribution a l'etude structurale et cinetique de la transformation lente d'un cristal de fer alpha ou d'uranium alpha

    Energy Technology Data Exchange (ETDEWEB)

    Donze, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-12-15

    1- During the course of the work reported, we observed and studied a curious phenomenon of regeneration of an iron or uranium {alpha} crystal in the double transformation of iron or uranium: {alpha} {yields} {gamma} {yields} {alpha} and {alpha} {yields} {beta} {yields} {alpha} respectively. We have demonstrated that this phenomenon does not occur with very pure metals, but only in the case of metals containing impurities, and more particularly, containing carbon. The monocrystal is not regenerated unless care is taken not to exceed final transformation temperatures by more than a few degrees. The same phenomenon is encountered in polycrystalline compounds: the orientation of the crystals is maintained, though the respective grain positions ('joints') are considerably displaced. 2- Kinetic study of the transformation at cooling, on the one hand, and the analysis of the texture at the {gamma} phase (iron) on the other, show that regeneration results from the conservation of the phase {alpha} germs at the high temperature phase. They appear to be relatively stable because they had retained their properties at the end of 24 hours at the experiment temperature. 3- Study of the twin crystals of {gamma} iron engendered by the transformation {alpha} {yields} {gamma} demonstrated that there is no orientation relationship in the transformation: {alpha} {yields} {gamma} of pure iron. 4- Thanks to the production of an epitaxic oxide film on the surface of {gamma} iron, we were able to evidence a new type of iron transformation twinned crystal which grows in one direction (110) and is in contact also at 110. Formed of very thin lamina, these crystals are very instable and become penetrant, each element - much larger - consisting of the increased thickness of a certain number of lamina. (author) [French] 1- Au cours de ce travail, nous avons observe et etudie un curieux phenomene de regeneration d'un cristal unique de fer {alpha} ou d'uranium {alpha} au cours de la double

  14. Du Golgotha au tzompantli

    OpenAIRE

    Mongne, Pascal

    2013-01-01

    Plusieurs dizaines de crânes en cristal de roche, attribués aux Aztèques, sont comptés dans le monde, dont une douzaine de « grands » modèles. Ces derniers, par les pouvoirs « eschatologiques » que certains leur accordent, sont devenus célèbres et ont pu inspirer une récente production cinématographique. De nouvelles études ont cependant démontré que ces belles pièces ne sont pas aztèques et ont été réalisées tardivement dans un matériau non mexicain. Si l’authenticité des crânes de cristal e...

  15. Long-Term Evaluation of Biotronik Linox and Linox(smart) Implantable Cardioverter Defibrillator Leads.

    Science.gov (United States)

    Good, Eric D; Cakulev, Ivan; Orlov, Michael V; Hirsh, David; Simeles, John; Mohr, Kelly; Moll, Phil; Bloom, Heather

    2016-06-01

    Expert consensus holds that post-market, systematic surveillance of ICD leads is essential to ensure confirmation of adequate lead performance. GALAXY (NCT00836589) and CELESTIAL (NCT00810264) are ongoing multicenter, prospective, non-randomized registries conducted to confirm the long-term safety and reliability of Biotronik leads. ICD and CRT-D patients are followed for Linox and Linox(smart) ICD lead performance and safety for 5 years post-implant. All procedural and system-related adverse events (AEs) were assessed at each follow-up, along with lead electrical parameters. An independent CEC of EPs adjudicated AEs to determine AE category and lead relatedness. The analysis used categories of lead observations per ISO 5841-2 (Third edition). A total of 3,933 leads were implanted in 3,840 patients (73.0% male, mean age 67.0 ± 12.2 years) at 146 US centers. The estimated cumulative survival probability was 96.3% at 5 years after implant for Linox leads and 96.6% at 4 years after implant for Linox(smart) leads. A comparison of the Linox and Linox(smart) survival functions did not find evidence of a difference (P = 0.2155). The most common AEs were oversensing (23, 0.58%), conductor fracture (14, 0.36%), failure to capture (13, 0.33%), lead dislodgement (12, 0.31%), insulation breach (10, 0.25%), and abnormal pacing impedance (8, 0.20%). Linox and Linox(smart) ICD leads are safe, reliable and infrequently associated with lead-related AEs. Additionally, estimated cumulative survival probability is clinically acceptable and well within industry standards. Ongoing data collection will confirm the longer-term safety and performance of the Linox family of ICD leads. © 2016 Wiley Periodicals, Inc.

  16. First detection of lead in black paper from intraoral film

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Debora F.C., E-mail: defcg@usp.br [Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil); Silva, Reginaldo S. [Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil); Veiga, Marcia A.M.S. da [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil); Pecora, Jesus D. [Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil)

    2009-10-30

    Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirao Preto, University of Sao Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 {mu}g g{sup -1}, 189 {mu}g g{sup -1}, 20.8 {mu}g g{sup -1}, and 54.0 {mu}g g{sup -1}, respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise.

  17. A multi-level model of blood lead as a function of air lead.

    Science.gov (United States)

    Richmond-Bryant, Jennifer; Meng, Qingyu; Davis, J Allen; Cohen, Jonathan; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa; Kotchmar, Dennis; Hines, Erin; Ross, Mary

    2013-09-01

    National and local declines in lead (Pb) in blood (PbB) over the past several years coincide with the decline in ambient air Pb (PbA) concentrations. The objective of this work is to evaluate how the relationship between PbB levels and PbA levels has changed following the phase out of leaded gasoline and tightened controls on industrial Pb emissions over the past 30 years among a national population sample. Participant-level data from the National Health and Nutrition Examination Survey (NHANES) were employed for two time periods (1988-1994 and 1999-2008), and the model was corrected for housing, demographic, socioeconomic, and other covariates present in NHANES. NHANES data for PbB and covariates were merged with PbA data from the U.S. Environmental Protection Agency. Linear mixed effects models (LMEs) were run to assess the relationship of PbB with PbA; sample weights were omitted, given biases encountered with the use of sample weights in LMEs. The 1988-1994 age-stratified results found that ln(PbB) was statistically significantly associated with ln(PbA) for all age groups. The consistent influence of PbA on PbB across age groups for the years 1988-1994 suggests a ubiquitous exposure unrelated to age of the sample population. The comparison of effect estimates for ln(PbA) shows a statistically significant effect estimate and ANOVA results for ln(PbB) for the 6- to 11-year and 12- to 19-year age groups during 1999-2008. The more recent finding suggests that PbA has less consistent influence on PbB compared with other factors. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Fabrication of Radiation Shielding Glasses Based on Lead-free High Refractive Index Glasses Prepared from Local Sand

    International Nuclear Information System (INIS)

    Dararutana, Pisutti; Dutchaneepet, Jirapan; Sirikulrat, Narin

    2007-08-01

    Full text: Lead glasses that show high refractive index are the best know and most popular for radiation shielding. Due to harmful effects of lead and considering the health as well as the environmental issues, lead-free glasses were developed. In this work, content of Chumphon sand was fixed at 40 % (by weight) as a main composition but concentrations of BaCO3 were varied from 6 to 30 % (by weight). It was found that the absorption coefficient of the glass samples containing 30 % BaCO3 was 0.233 cm-1 for Ba-133. The density was also measured. It can be concluded that the prepared lead free glasses offered adequate shielding to gamma radiation in comparison with the lead ones. These glasses were one of the environmental friendly materials

  19. Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

    International Nuclear Information System (INIS)

    Giannetti, Fabio; Vitale Di Maio, Damiano; Naviglio, Antonio; Caruso, Gianfranco

    2016-01-01

    Highlights: • LOOP thermal-hydraulic transient analysis for lead-cooled fast reactors. • Passive decay heat removal system concept to avoid lead freezing. • Solution developed for the diversification of the decay heat removal functions. • RELAP5 vs. RELAP5-3D comparison for lead applications. - Abstract: Improvement of safety requirements in GEN IV reactors needs more reliable safety systems, among which the decay heat removal system (DHR) is one of the most important. Complying with the diversification criteria and based on pure passive and very reliable components, an additional DHR for the ALFRED reactor (Advanced Lead Fast Reactor European Demonstrator) has been proposed and its thermal-hydraulic performances are analyzed. It consists in a coupling of two innovative subsystems: the radiative-based direct heat exchanger (DHX), and the pool heat exchanger (PHX). Preliminary thermal-hydraulic analyses, by using RELAP5 and RELAP5-3D© computer programs, have been carried out showing that the whole system can safely operate, in natural circulation, for a long term. Sensitivity analyses for: the emissivity of the DHX surfaces, the PHX water heat transfer coefficient (HTC) and the lead HTC have been carried out. In addition, the effects of the density variation uncertainty on the results has been analyzed and compared. It allowed to assess the feasibility of the system and to evaluate the acceptable range of the studied parameters. A comparison of the results obtained with RELAP5 and RELAP5-3D© has been carried out and the analysis of the differences of the two codes for lead is presented. The features of the innovative DHR allow to match the decay heat removal performance with the trend of the reactor decay heat power after shutdown, minimizing at the same time the risk of lead freezing. This system, proposed for the diversification of the DHR in the LFRs, could be applicable in the other pool-type liquid metal fast reactors.

  20. Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Giannetti, Fabio; Vitale Di Maio, Damiano; Naviglio, Antonio; Caruso, Gianfranco, E-mail: gianfranco.caruso@uniroma1.it

    2016-08-15

    Highlights: • LOOP thermal-hydraulic transient analysis for lead-cooled fast reactors. • Passive decay heat removal system concept to avoid lead freezing. • Solution developed for the diversification of the decay heat removal functions. • RELAP5 vs. RELAP5-3D comparison for lead applications. - Abstract: Improvement of safety requirements in GEN IV reactors needs more reliable safety systems, among which the decay heat removal system (DHR) is one of the most important. Complying with the diversification criteria and based on pure passive and very reliable components, an additional DHR for the ALFRED reactor (Advanced Lead Fast Reactor European Demonstrator) has been proposed and its thermal-hydraulic performances are analyzed. It consists in a coupling of two innovative subsystems: the radiative-based direct heat exchanger (DHX), and the pool heat exchanger (PHX). Preliminary thermal-hydraulic analyses, by using RELAP5 and RELAP5-3D© computer programs, have been carried out showing that the whole system can safely operate, in natural circulation, for a long term. Sensitivity analyses for: the emissivity of the DHX surfaces, the PHX water heat transfer coefficient (HTC) and the lead HTC have been carried out. In addition, the effects of the density variation uncertainty on the results has been analyzed and compared. It allowed to assess the feasibility of the system and to evaluate the acceptable range of the studied parameters. A comparison of the results obtained with RELAP5 and RELAP5-3D© has been carried out and the analysis of the differences of the two codes for lead is presented. The features of the innovative DHR allow to match the decay heat removal performance with the trend of the reactor decay heat power after shutdown, minimizing at the same time the risk of lead freezing. This system, proposed for the diversification of the DHR in the LFRs, could be applicable in the other pool-type liquid metal fast reactors.

  1. 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

  2. Immediacy bias in social-emotional comparisons.

    Science.gov (United States)

    White, Katherine; Van Boven, Leaf

    2012-08-01

    In seven studies of naturally occurring, "real-world" emotional events, people demonstrated an immediacy bias in social-emotional comparisons, perceiving their own current or recent emotional reactions as more intense compared with others' emotional reactions to the same events. The events examined include crossing a scary bridge (study 1a), a national tragedy (study 1b), terrorist attacks (studies 2a and 3b), a natural disaster (study 2b), and a presidential election (study 3b). These perceived differences between one's own and others' emotions declined over time, as relatively immediate and recent emotions subsided, a pattern that people were not intuitively aware of (study 2c). This immediacy bias in social-emotional comparisons emerged for both explicit comparisons (studies 1a, 1b, and 3b), and for absolute judgments of emotional intensity (studies 2a, 2b, and 3a). Finally, the immediacy bias in social-emotional comparisons was reduced when people were reminded that emotional display norms might lead others' appearances to understate emotional intensity (studies 3a and 3b). Implications of these findings for social-emotional phenomena are discussed.

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. A wearable 12-lead ECG acquisition system with fabric electrodes.

    Science.gov (United States)

    Haoshi Zhang; Lan Tian; Huiyang Lu; Ming Zhou; Haiqing Zou; Peng Fang; Fuan Yao; Guanglin Li

    2017-07-01

    Continuous electrocardiogram (ECG) monitoring is significant for prevention of heart disease and is becoming an important part of personal and family health care. In most of the existing wearable solutions, conventional metal sensors and corresponding chips are simply integrated into clothes and usually could only collect few leads of ECG signals that could not provide enough information for diagnosis of cardiac diseases such as arrhythmia and myocardial ischemia. In this study, a wearable 12-lead ECG acquisition system with fabric electrodes was developed and could simultaneously process 12 leads of ECG signals. By integrating the fabric electrodes into a T-shirt, the wearable system would provide a comfortable and convenient user interface for ECG recording. For comparison, the proposed fabric electrode and the gelled traditional metal electrodes were used to collect ECG signals on a subject, respectively. The approximate entropy (ApEn) of ECG signals from both types of electrodes were calculated. The experimental results show that the fabric electrodes could achieve similar performance as the gelled metal electrodes. This preliminary work has demonstrated that the developed ECG system with fabric electrodes could be utilized for wearable health management and telemedicine applications.

  7. Suurosalusega juht kasulikum investorile / Tarvo Vaarmets

    Index Scriptorium Estoniae

    Vaarmets, Tarvo

    2007-01-01

    Bloombergi kolumnist ja finantskonsultant Greaf Cristal järeldas USA suurettevõtete juhte ja finantsandmeid uurides, et osalus motiveerib tegevjuhte enam kui palk. Diagramm: Berkshire Hathaway aktsia tõusis mullu 23 protsenti

  8. Bulk diffusion and solubility of silver and nickel in lead, lead-silver and lead-nickel solid solutions

    International Nuclear Information System (INIS)

    Amenzou-Badrour, H.; Moya, G.; Bernardini, J.

    1988-01-01

    The results of a study of solubility and bulk diffusion of /sup 110/Ag and /sup 63/Ni in lead, lead-silver and lead-nickel solid solutions in the temperature range 220 to 88 0 C are reported. Owing to the low solubility of silver and nickel in lead, Fick's solution corresponding to the boundary condition of a constant concentration of solute at the surface has been used. Depth profile concentration analysis suggests a fundamental difference between the diffusion mechanisms of silver and nickel. Since silver penetration profiles in pure lead give diffusion coefficients independent of the penetration depth and silver concentration, it is suggested that slight decreases of silver diffusivity in lead-silver solid solutions have no significance. This implies that the interstitial silver atoms do not associate significantly with each other to form Ag-Ag dimers. In contrast, different behaviors of /sup 63/Ni depth profile concentration in pure lead and saturated PbNi solid solutions agree with a Ni-Ni interaction leading to the formation of less mobile dimers near the surface in pure lead

  9. Leading internal and external sources of credit risk in the top South African banks

    Directory of Open Access Journals (Sweden)

    Tankiso Moloi

    2014-09-01

    Full Text Available This paper aimed at identifying the leading credit risk indicators in the South African banking context as well as the development of an integrated leading credit risk indicator model. A content analysis was used as a data extraction methodology and structural equation modelling was used as a data analysis methodology. The results obtained indicated that utilising the structural equation modelling, gross savings, and prime overdraft rates, number of judgements, business insolvencies and unemployment rates were formulated as leading economic and market (external indicators of credit risk in the South African banking context. Similarly, utilising the principal component analysis, bank asset quality, bank asset concentration as well as bank trading and hedging activities were formulated as leading bank specific (internal indicators of credit risk in the South African banking context. The Integrated Leading Credit Risk Indicator Model (ICRIM was formulated utilising the accepted leading credit risk indicators. The ICRIM parameters were benchmarked against the generally accepted fit indices such as the RMSEA, comparative fit (baseline comparison as well as the Hoelter and its results output were found to be consistent with these generally accepted fit indices

  10. The Current Status of Microscopical Hair Comparisons

    Directory of Open Access Journals (Sweden)

    Walter F. Rowe

    2001-01-01

    Full Text Available Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation leads to three conclusions: (1 microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2 the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3 forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court’s Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

  11. 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

  12. 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....

  13. 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

  14. Concentrations of heavy metals (lead, manganese, cadmium) in blood and urine of former uranium workers

    International Nuclear Information System (INIS)

    Apostolova, D.; Pavlova, S.; Paskalev, Z.

    1999-01-01

    Uranium ores contain heavy metals and other stable chemical elements as oxides, hydro-carbonates, sulphates, etc. During chemical processing of ore they could be transformed into compounds soluble in biologic liquids. The purpose of this study was to determine the combined intoxication of uranium miners and millers by heavy metals and radiation. Heavy metal (lead, manganese and cadmium) concentrations in blood and urine od 149 former uranium miners and millers were determined by AAS method. Data of significantly increased lead and manganese concentration in blood (p<0.05) of two groups were established in comparison with a control group. There is no statistical significant differences in the cadmium concentrations. The lead and manganese blood levels at the uranium millers were significant higher than those of the uranium miner group (p<0.05). Tendency towards increased blood lead concentrations of uranium millers depending on the length of service was established

  15. Produção de cultivares de nespereira na região Leste paulista Production of loquat tree cultivars in Eastern São Paulo State

    Directory of Open Access Journals (Sweden)

    Rafael Pio

    2007-07-01

    Full Text Available O objetivo deste trabalho foi avaliar a capacidade produtiva das cultivares de nêspera (Eriobotrya japonica Lindl. Mizuho, Centenária, Mizumo, Mizauto e Néctar de Cristal, em Jundiaí, SP. As mudas, formadas com porta-enxertos de 'Mizumo', foram plantadas em campo em blocos ao acaso. Do terceiro ao sexto ano de plantio, quantificaram-se o número e a massa de matéria fresca dos frutos, a produção total por planta e as médias dos quatro anos de produção. Determinaram-se o comprimento, a largura, a relação sólidos solúveis totais (SST e a acidez total titulável (ATT. As cultivares Mizuho, Mizumo, Mizauto e Néctar de Cristal apresentaram as maiores produções de frutos, acima de 14 kg por planta em média. 'Centenária' e 'Mizumo' apresentaram os maiores resultados de massa de matéria fresca dos frutos, acima de 30 g por fruto, e a melhor razão SST/ATT.The objective of this work was to evaluate the yield of the loquat tree (Eriobotrya japonica Lindl. cultivars Centenária, Mizuho, Mizumo, Mizauto and Néctar de Cristal. The seedlings grown on cultivar Mizumo rootstocks were planted in the field in a randomized block design. From the third to the sixth year after planting, evaluations were made for fruit number, fresh weight, total yield per plant and the average data of four consecutive years. The length and width, the total soluble solids (TSS and the total titrable acidity (TTA were determined. The cultivars Mizuho, Mizumo, Mizauto and Néctar de Cristal showed the highest fruit yield, over 14 kg per plant, on average. The fruit fresh weight best results were observed for 'Centenária' and 'Mizumo', over 30 g per fruit. Both cultivars also showed the better ratio SST/ATT.

  16. Surface Treatment to Improve Corrosion Resistance in Lead-Alloy Coolants

    International Nuclear Information System (INIS)

    Todd R. Allen; Kumar Sridharan; McLean T. Machut; Lizhen Tan

    2007-01-01

    One of the six proposed advanced reactor designs of the Generation IV Initiative, the Lead-cooled Fast Reactor (LFR) possesses many characteristics that make it a desirable candidate for future nuclear energy production and responsible actinide management. These characteristics include favorable heat transfer, fluid dynamics, and neutronic performance compared to other candidate coolants. However, the use of a heavy liquid metal coolant presents a challenge for reactor designers in regards to reliable structural and fuel cladding materials in both a highly corrosive high temperature liquid metal and an intense radiation field. Flow corrosion studies at the University of Wisconsin have examined the corrosion performance of candidate materials for application in the LFR concept as well as the viability of various surface treatments to improve the materials compatibility. To date this research has included several focus areas, which include the formulation of an understanding of corrosion mechanisms and the examination of the effects of chemical and mechanical surface modifications on the materials performance in liquid lead-bismuth by experimental testing in Los Alamos National Laboratory's DELTA Loop, as well as comparison of experimental findings to numerical and physical models for long term corrosion prediction. This report will first review the literature and introduce the experiments and data that will be used to benchmark theoretical calculations. The experimental results will be followed by a brief review of the underlying theory and methodology for the physical and theoretical models. Finally, the results of theoretical calculations as well as experimentally obtained benchmarks and comparisons to the literature are presented

  17. The Cascade Mountains revisited: A re-evaluation in light of new lead isotopic data

    International Nuclear Information System (INIS)

    Church, S.E.

    1976-01-01

    Lead isotopic analyses have been repeated using silica gel for several samples from the Cascade Mountains which were previously analyzed by lead sulfide. The improved precision indicates that some of the scatter in the original data was due to thermal fractionation; however, the bulk of the data have not changed significantly. Two-point mixing lines are demonstrated for main cone-satellitic cone pairs from Glacier Peak, Mt. Baker and Mt. Shasta. Comparison with data on oceanic basalts from the Juan de Fuca and Gorda Ridge area indicates that hypothesis of mixing of mid-ocean ridge (MOR) basalt lead and 'alkali basalt-like' lead from the oceanic crust is not tenable. Lead isotope analyses of pre-Astoria Fan sediments from DSDP Leg 18 sites and from the Eocene Tyee Formation indicate that the sedimentary continental detritus from the North American continent has the correct lead isotopic composition to be the continental component necessary to account for the Cascade Mountains lead isotopic array by mixing with Juan de Fuca-Gorda Ridge MOR basalts. However, from recent work on the structure of oceanic trenches by Karig and Sharman (1975), it does not appear that subduction of sediments is the rule. A model of crustal contamination and/or assimilation at the crust/mantle interface is the preferred explanation for the lead isotopic data from the Cascade Mountains. (Auth.)

  18. Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

    Science.gov (United States)

    De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

    2017-02-16

    Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation ("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

  19. Optical diagnostics of lead and PbGa2S4 layered crystal laser plasmas

    International Nuclear Information System (INIS)

    Shuaibov, A.K.; Dashchenko, A.I.; Shevera, I.V.

    2001-01-01

    Paper presents the results of the optic diagnostics of plasma of laser flames formed from lead surface and PbGa 2 S 4 laminar crystal using a neodymium laser. It is shown that the most intensive lines in the lead laser plasma are as follows: 405.7, 368.3, 364.0 nm PbI and 220.4 nm PbII while for the laminar crystal base plasma - the combination of the most intensive lines of PbI and GaI emission. One determined the narrow point of recombination fluxes for the ion and the atomic components of laser plasma of lead and of PbGa 2 S 4 crystal. One conducted comparison study of emission dynamics of PbI and GaI lines in laser plasma of the respective metals and of PbGa 2 S 4 crystal [ru

  20. Misure di fenomeni di interazione coerente di protoni a 400 GeV con cristalli curvi per l'LHC

    CERN Document Server

    Rossi, Roberto; Redaelli, Stefano; Scandale, Walter

    A complete analysis of the UA9 H8 data with protons interacting in single pass with crystals had been completed. The analysis is optimized for comparison with simulations routine. Measurements of key crystals properties (bending angle, channeling efficiency, etc.) are performed on the SPS extraction line (H8) with 400 GeV/c protons before testing crystals with circulating beams. A total of 15 crystals had been consistently analyzed in order to compile a comprehensive statistical treatment of different crystals, to identify 'fine' systematic effects (transition region, volume capture, etc. ) and to provide inputs to crystal code developer. Hence we compiled a list of experimental data for the upcoming workshop on crystal simulations, with the analysis results.

  1. 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

  2. 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.

  3. 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

  4. Social comparison as a predictor of body dissatisfaction: A meta-analytic review.

    Science.gov (United States)

    Myers, Taryn A; Crowther, Janis H

    2009-11-01

    The relationship between social comparison and body dissatisfaction was examined using meta-analysis. Several demographic and methodological variables were examined as potential moderators. Data from 156 studies (189 effect sizes) showed that social comparison was related to higher levels of body dissatisfaction. The effect for social comparison and body dissatisfaction was stronger for women than men and inversely related to age. This effect was stronger when social comparison was directly measured rather than inferred. No differences emerged for the presence of eating psychopathology, study design, or object of comparison. Results confirm theory and research suggesting that comparing oneself unfavorably to another on the basis of appearance may lead to dissatisfaction with one's own appearance. Moderator variables refine our understanding of the social comparison-body dissatisfaction relationship. These constructs and their relationship should be explored further in future studies. PsycINFO Database Record 2009 APA, all rights reserved.

  5. Evaluation of neutron and gamma-ray-production cross-section data for lead

    International Nuclear Information System (INIS)

    Fu, C.Y.; Perey, F.G.

    1975-01-01

    A survey was made of the available information on neutron and gamma-ray-production cross-section measurements of lead. From these and from relevant nuclear-structure information on the Pb isotopes, recommended neutron cross-section data sets for lead covering the neutron energy range from 0.00001 eV to 20.0 MeV have been prepared. The cross sections are derived from experimental results available to February 1972 and from calculations based on optical-model, DWBA, and Hauser--Feshbach theories. Comparisons which show good agreement between theoretical and experimental values are displayed in a number of graphs. Also presented graphically are smoothed total cross sections, Legendre coefficients for angular distributions, and a representative energy distribution of gamma rays from resonance capture. 15 tables, 36 figures, 104 references

  6. Estimation of the exchange current density and comparative analysis of morphology of electrochemically produced lead and zinc deposits

    Directory of Open Access Journals (Sweden)

    Nikolić Nebojša D.

    2017-01-01

    Full Text Available The processes of lead and zinc electrodeposition from the very dilute electrolytes were compared by the analysis of polarization characteristics and by the scanning electron microscopic (SEM analysis of the morphology of the deposits obtained in the galvanostatic regime of electrolysis. The exchange current densities for lead and zinc were estimated by comparison of experimentally obtained polarization curves with the simulated ones obtained for the different the exchange current density to the limiting diffusion current density ratios. Using this way for the estimation of the exchange current density, it is shown that the exchange current density for Pb was more than 1300 times higher than the one for Zn. In this way, it is confirmed that the Pb electrodeposition processes are considerably faster than the Zn electrodeposition processes. The difference in the rate of electrochemical processes was confirmed by a comparison of morphologies of lead and zinc deposits obtained at current densities which corresponded to 0.25 and 0.50 values of the limiting diffusion current densities. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172046

  7. Enxertia intergenérica de cultivares de nespereira no porta-enxerto de marmeleiro 'japonês' Intergeneric grafting of loquat cultivars using 'Japonese' quince tree as rootstock

    Directory of Open Access Journals (Sweden)

    Rafael Pio

    2010-12-01

    Full Text Available No Brasil, foram desenvolvidos alguns trabalhos pioneiros com a utilização do marmeleiro (Cydonia oblonga Mill. como porta-enxertos para as nespereiras (Eriobotrya japonica (Thunb. Lindl.. O sucesso da utilização dessa enxertia intergenérica está relacionado, principalmente, à redução do porte da planta. Objetivou-se, neste trabalho estudar técnicas de enxertia de cultivares de nespereiras, utilizando-se o marmeleiro 'Japonês' (Chaenomeles sinensis (Thouin Koehne como nova opção de porta-enxerto. Mudas de marmeleiro 'Japonês' com um ano de idade (altura próxima a 110 cm e diâmetro de 0,85 cm na região de enxertia, a 15 cm acima do colo, mantidos em sacos plásticos com dimensões de 18 x 30 cm (capacidade de 3 L, foram enxertados pelos métodos de borbulhia em placa e garfagem em fenda cheia, em duas diferentes épocas: outono (abril e inverno (julho. Utilizaram-se cinco cultivares de nespereira de importância econômica no Brasil: 'Mizuho', 'Néctar de Cristal' (IAC 866-7, 'Mizauto' (IAC 167-4, 'Mizumo' (IAC 1567-411 e 'Centenária' (IAC 1567-420. Pelo método de borbulhia, não houve nenhuma borbulha brotada quando esta foi realizada no outono, apenas duas borbulhas da 'Mizauto', 'Néctar de Cristal' e 'Centenária' brotaram quando esta foi realizada no inverno, no entanto, com baixo crescimento. Já, por garfagem, maiores porcentagens de brotação e crescimento dos enxertos foram obtidas quando a enxertia foi realizada no inverno, com destaque para as nespereiras 'Mizuho', 'Centenária' e 'Néctar de Cristal'.In Brazil, some pioneer studies were carried out using quince seedlings (Cydonia oblonga Mill. as rootstock for loquat (Eriobotrya japonica (Thunb. Lindl.. The main advantage of this intergeneric grafting use is plant size reduction. The success of using this intergeneric grafting is related mainly to plant size reduction. Therefore, the objective of this work was to study grafting techniques of loquat cultivars using

  8. Novel porous fly-ash containing geopolymer monoliths for lead adsorption from wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Novais, Rui M., E-mail: ruimnovais@ua.pt; Buruberri, L.H.; Seabra, M.P.; Labrincha, J.A.

    2016-11-15

    Highlights: • Porous fly ash containing-geopolymer monoliths for lead adsorption were developed. • Geopolymers’ porosity and pH of the ion solution controls the adsorption capacity. • Lead adsorption by the geopolymer monoliths up to 6.34 mg/g was observed. • These novel adsorbents can be used in packed beds that are easily collected. • The reuse of biomass fly ash wastes as raw material ensures waste valorization. - Abstract: In this study novel porous biomass fly ash-containing geopolymer monoliths were produced using a simple and flexible procedure. Geopolymers exhibiting distinct total porosities (ranging from 41.0 to 78.4%) and low apparent density (between 1.21 and 0.44 g/cm{sup 3}) were fabricated. Afterwards, the possibility of using these innovative materials as lead adsorbents under distinct conditions was evaluated. Results demonstrate that the geopolymers’ porosity and the pH of the ion solution strongly affect the lead adsorption capacity. Lead adsorption by the geopolymer monoliths ranged between 0.95 and 6.34 mg{sub lead}/g{sub geopolymer}. More porous geopolymers presented better lead removal efficiency, while higher pH in the solution reduced their removal ability, since metal precipitation is enhanced. These novel geopolymeric monoliths can be used in packed beds that are easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Furthermore, their production encompasses the reuse of biomass fly-ash, mitigating the environmental impact associated with this waste disposal, while decreasing the adsorbents production costs.

  9. Detailed comparison of next-to-leading order predictions for jet photoproduction at HERA.

    Energy Technology Data Exchange (ETDEWEB)

    Harris, B. W.; Klassen, M.; Vossebeld, J.

    1999-06-02

    The precision of new HERA data on jet photoproduction opens up the possibility to discriminate between different models of the photon structure. This requires equally precise theoretical predictions from perturbative QCD calculations. In the past years, next-to-leading order calculations for the photoproduction of jets at HERA have become available. Using the kinematic cuts of recent ZEUS analyses, we compare the predictions of three calculations for different dijet and three-jet distributions. We find that in general all three calculations agree within the statistical accuracy of the Monte Carlo integration yielding reliable theoretical predictions. In certain restricted regions of phase space, the calculations differ by up to 5%.

  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. 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.

  12. 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 ...

  13. Study of lead pollution from automobile emissions in Khartoum

    International Nuclear Information System (INIS)

    Ibrahim, A.S.

    2002-07-01

    Aerosol and soil samples were collected from places near the main roads in Khartoum area. The samples were analyzed by energy Dispersive x-ray fluorescence (EDXRF) technique, to study the lead (Pb) concentration in air and soil near roadsides due to automobile emissions. The aim of the study was also to make a comparison with the results of previous measurements made in the same field (Ahmed, 1983) . Thee aerosol samples were taken from three sites in Khartoum area. Tuti island taken as a control area, central Khartoum as a commercial area and south of Khartoum as a residential area. Soil samples were taken from a place near Al Gurashi Park and another near Abu Hamama traffic junction in Khartoum area. The data obtained of (Pb) concentrations in the roadside air were statistically analyzed. Comparisons were made between the concentrations at the various times of the day and correlation were made with meteorological parameters. The (Pb) concentrations in the roadside soil were observed to be inversely proportional to the distance from the road and the depth from the layer of the earth. Finally, the results obtained are discussed and some recommendations are suggested. (Author)

  14. Lead and osteoporosis: Mobilization of lead from bone in postmenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Silbergeld, E.K. (Environmental Defense Fund, WA (USA)); Schwartz, J. (Environmental Protection Agency, Washington, DC (USA)); Mahaffey, K. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

    1988-10-01

    Although it has been known that humans accumulate lead in bone, mineralized tissue has been considered primarily as a sequestering compartment and not as a site of toxic action for lead. However, experimental data indicate that bone lead can be released during conditions of demineralization, such as pregnancy and lactation. We have examined lead status in women, before and after menopause, using the NHANES II dataset compiled between 1976 and 1980. In 2981 black and white women there was a highly significant increase in both whole blood and calculated plasma lead concentrations after menopause. The results indicate that bone lead is not an inert storage site for absorbed lead. Moreover, lead may interact with other factors in the course of postmenopausal osteoporosis, to aggravate the course of the disease, since lead is known to inhibit activation of vitamin D, uptake of dietary calcium, and several regulatory aspects of bone cell function. The consequences of this mobilization may also be of importance in assessing the risks of maternal lead exposure to fetal and infant health.

  15. Blood Lead Level and Δ-Aminolevulinic Acid Dehydratase Activity in Pre-Menopausal and Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    I.R Elezaj

    2012-07-01

    Full Text Available To describe the relationship of blood lead levels (BLL and blood, δ-aminolevulinic acid dehydratase(ALAD activity and haematocrit value(Hct to menopause , were examined 17 pre-or perimenopausal (PreM and 17 postmenopausal women (PosMfrom Prishtina City, the capital ofRepublic Kosovo. The mean age of the PreM women was 28.8 years (21-46, with a mean blood lead level of 1.2 μg/dL (SD=0.583 μg/dL , the mean blood ALAD activity53.2 U/LE (SD= 2.8 U/LE and haematocrit value42.1 % (SD= 4.3 %. The mean age of the PosM women was 53.6 years (43-67, with a mean blood lead level1.9 μg/dL (SD=0.94 μg/dL, the mean blood ALAD activity 44.4 U/LE(SD=7.2 U/LE and haematocrit value 42.1 % ( SD= 4.3 % and 42.2 % (SD=4.4 %. The BPb level of PosM women was significantly higher (P<0.001 in comparison with the BPb level in PreM women. The blood ALAD activity of PosM was significantly inhibited (P<0.002 in comparison with blood ALAD activity in PreM women. The haematocrit values were relatively unchanged. There was established significantly negative correlation between BPb and blood ALAD activity (r=- 0.605; P<0.01 in the PreM women.These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with adverse health effects on women in menopause transition.

  16. 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.

  17. Government-Leading Student Loan Schemes A Comparative Study of Hong Kong and Mainland China

    Directory of Open Access Journals (Sweden)

    Antonia Jiewei Lu

    2014-02-01

    Full Text Available Having a careful examination of government-leading student loan schemes in China and Hong Kong, we can find a lot of differences and learn something from these two counterparts which are very typical country or area faced by challenges in financing higher education in the context of transition from elitism to mass higher education. This research attempts to make a comparison of government-leading student loan schemes between Hong Kong and China in the new century. Then emphasis is put on the principles or core values namely efficiency, equity and adequacy, and determining their implications presented in student loan schemes in these two counterparts. Finally, the paper arrives at some recommendations for improvements in them.

  18. L-shell x-ray fluorescence measurements of lead in bone: accuracy and precision

    International Nuclear Information System (INIS)

    Todd, Andrew C.; Carroll, Spencer; Khan, Fuad A.; Moshier, Erin L.; Geraghty, Ciaran; Tang, Shida; Parsons, Patrick J.

    2002-01-01

    This study aimed to quantify the accuracy and precision of a method for in vivo measurements of lead in bone using L-shell x-ray fluorescence (LXRF), the former via comparison with independent measurements of lead in bone obtained using electrothermal atomic absorption spectrometry (AAS) following acid digestion. Using LXRF, the lead content of adult human cadaver tibiae was measured, both as intact legs and as dissected tibiae with overlying tissue removed, the latter at several proximal-distal locations. After LXRF, each tibia was divided into nine cross-sectional segments, which were further separated into tibia core and surface samples for AAS measurement. The proximal-distal variability of AAS-measured core and surface tibia lead concentrations has been described elsewhere (the lead concentration was found to decrease towards both ends of the tibia). The subjects of this paper are the proximal-distal variability of the LXRF-measured lead concentrations, the measurement uncertainty and the statistical agreement between LXRF and AAS. There was no clear proximal-distal variability in the LXRF-measured concentrations; the degree of variability in actual tibia lead concentrations is far less than the LXRF measurement uncertainty. Measurement uncertainty was dominated by counting statistics and exceeded the estimate of lead concentration in most cases. The agreement between LXRF and AAS was reasonably good for bare bone measurements but poor for intact leg measurements. The variability of the LXRF measurements was large enough, for both bare bone and intact leg measurements, to yield grave concerns about the analytical use of the technique in vivo. (author)

  19. KEY COMPARISON: Report on the Regional Comparison COOMET.AUV.A-K3

    Science.gov (United States)

    Barrera-Figueroa, Salvador; Nielsen, Lars; Rasmussen, Knud

    2007-01-01

    COOMET.AUV.A-K3 is a Regional Comparison that supplements the Key Comparison CCAUV.A-K3 organized by the CCAUV. The participating NMIs are GUM (Poland), INM (Romania), VNIIFTRI (Russia) and DP-NDI 'Systema' (Ukraine). The role of Pilot laboratory was undertaken by DPLADFM (Denmark). The measurements took place between May 2005 and February 2006. The time schedule was organized in a single star configuration. Initially, two LS2aP microphones were circulated. However, a sudden change of sensitivity of one of them forced the inclusion of an additional microphone. Nevertheless, the analysis was performed on all microphones involved. This report includes the measurement results from the participants, information about their calibration methods, and the analysis leading to the assignation of degrees of equivalence and the link to the CCAUV.A-K3. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Comparison of trace element contamination levels (Cu, Zn, Fe, Cd ...

    African Journals Online (AJOL)

    Comparison of trace element contamination levels (Cu, Zn, Fe, Cd and Pb) in the soft tissues of the gastropods Tympanotonus fuscatus fuscatus and Tf radula collected in the Ebrié Lagoon (Côte d'Ivoire): Evidence of the risks linked to linked to lead and.

  1. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    Science.gov (United States)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  2. [Environmental lead poisoning from lead-glazed earthenware used for storing drinks].

    Science.gov (United States)

    Sabouraud, S; Coppéré, B; Rousseau, C; Testud, F; Pulce, C; Tholly, F; Blanc, M; Culoma, F; Facchin, A; Ninet, J; Chambon, P; Medina, B; Descotes, J

    2009-12-01

    Current unusual environmental sources of lead exposure mainly include traditional medicines, either ayurvedic remedies or others, traditional cosmetics (kohl, surma), and the use of traditional earthenware, for storage or cooking. We report two cases of lead poisoning in adults initially identified by paroxysmal abdominal pain or anemia. In both cases, the environmental investigation evidenced one main source of lead exposure, namely a lead-glazed earthenware jug in which a drink was stored, "kefir" in the first case, and "kombucha" tea in the second one. It is recommended to search for lead intoxication in patients with unexplained anemia. Environmental sources of lead can be multiple. Their relative importance has to be ranked during the environmental investigation and among these, lead-glazed earthenware must be considered as a source of high lead exposure when drinks are stored inside and thus can soak.

  3. 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.

  4. Effect measure modification of blood lead-air lead slope factors.

    Science.gov (United States)

    Richmond-Bryant, Jennifer; Meng, Qingyu; Cohen, Jonathan; Davis, J Allen; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa; Kotchmar, Dennis; Hines, Erin; Ross, Mary

    2015-01-01

    There is abundant literature finding that susceptibility factors, including race and ethnicity, age, and housing, directly influence blood lead levels. No study has explored how susceptibility factors influence the blood lead-air lead relationship nationally. The objective is to evaluate whether susceptibility factors act as effect measure modifiers on the blood lead-air lead relationship. Participant level blood lead data from the 1999 to 2008 National Health and Nutrition Examination Survey were merged with air lead data from the US Environmental Protection Agency. Linear mixed effects models were run with and without an air lead interaction term for age group, sex, housing age, or race/ethnicity to determine whether these factors are effect measure modifiers for all ages combined and for five age brackets. Age group and race/ethnicity were determined to be effect measure modifiers in the all-age model and for some age groups. Being a child (1-5, 6-11, and 12-19 years) or of Mexican-American ethnicity increased the effect estimate. Living in older housing (built before 1950) decreased the effect estimate for all models except for the 1-5-year group, where older housing was an effect measure modifier. These results are consistent with the peer-reviewed literature of time-activity patterns, ventilation, and toxicokinetics.

  5. 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 ...

  6. The refining of secondary lead for use in advanced lead-acid batteries

    International Nuclear Information System (INIS)

    Ellis, Timothy W.; Mirza, Abbas H.

    2010-01-01

    Secondary lead, i.e. material produced by the recycling of lead-acid batteries has become the primary source of lead in much of the world. This has been important to the secondary lead industry as other uses have dwindled, e.g. lead based pigments, chemicals, fuel additives, solders and CRT glasses. Presently, battery manufacturing accounts for greater than 80% of lead consumption while recycled lead accounts for approximately the same market share of lead supply. These two facts strongly demonstrate the battery manufacturing and recycled lead are intimately coupled in everyday life. In this paper we will explore how recycled lead has become the material of choice for battery construction through the development of a recovery and refining process that exceeds the industries requirements. Particular focus will be on addressing the results presented by Prengaman on the effects of contaminant or tramp elements on gassing in lead-acid batteries. (author)

  7. The effect of lead-based paint hazard remediation on blood lead levels of lead poisoned children in New York City.

    Science.gov (United States)

    Leighton, Jessica; Klitzman, Susan; Sedlar, Slavenka; Matte, Thomas; Cohen, Neal L

    2003-07-01

    Despite the widespread use of lead paint hazard control for children with lead poisoning, few controlled studies that estimate the effect of such control on children's blood lead levels have been published. This retrospective follow-up study examined the effects of lead hazard remediation and its timing on the blood lead levels of lead-poisoned children. From the New York City child blood lead registry, 221 children were selected who had an initial blood lead level of 20-44 micro g/dL between 1 July 1994 and 31 December 1996; were 6 months to 6 years of age; had a report of a follow-up blood lead test between 10 and 14 months after the initial test; had a lead-based paint hazard identified in the primary dwelling unit prior to the 10- to 14-month follow-up blood lead test; had resided or spent time at only one address with an identified lead-based paint hazard; and were not chelated. The decline in geometric mean blood lead levels from baseline to 10-14 months later was compared for children whose homes were remediated and whose homes were not remediated during the follow-up period. Regardless of remediation, geometric mean blood lead levels declined significantly from 24.3 micro g/dL at the initial diagnosis to 12.3 micro g/dL at the 10- to 14-month follow-up blood lead test (Premediated the geometric mean blood lead levels declined 53% compared to 41% among the 75 children whose homes were not remediated by the follow-up blood lead test, a remediation effect of approximately 20% (Premediation effect was 11%, although it was no longer significant. Race was the only factor that appeared to confound the relationship: Black children had higher follow-up blood lead levels even after controlling for other factors, including the natural logarithm of the initial blood lead level. The effect of remediation appeared to be stronger for younger (10 to remediation (within less than 3 months) appeared to have greater declines in blood lead levels at the follow-up test than

  8. Copper and lead levels in crops and soils of the Holland Marsh Area-Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Czuba, M.; Hutchinson, T.C.

    1980-01-01

    A study was made of the occurrence, distribution, and concentrations of the heavy metals copper (Cu) and lead (Pb) in the soils and crops of the important horticultural area north of Toronto known as the Holland Marsh. The soils are deep organic mucks (> 85% organic matter), derived by the drainage of black marshland soils, which has been carried out over the past 40 years. A comparison is made between the Pb and Cu concentrations in undrained, uncultivated areas of the marsh and in the intensively used horticultural area. Analyses show a marked accumulation of Cu in surface layers of cultivated soils, with a mean surface concentration of 130 ppM, declining to 20 ppM at a 32-cm depth. Undrained (virgin) soils of the same marshes had < 20 ppM at all depths. Lead concentrations also declined through the profile, from concentrations of 22 to 10 ppM. In comparison, undrained areas had elevated Pb levels. Cultivation appeared to have increased Cu, but lowered Pb in the marsh. Copper and lead levels found in the crops were generally higher in the young spring vegetables than in the mature fall ones. Leafy crops, especially lettuce (Lactuca L.) and celery (Apium graveolens), accumulated higher Pb levels in their foliage compared with levels in root crops. Cultivation procedures, including past pesticide applications and fertilizer additions, appeared to be principal sources of Cu. Mobility from the soil and into the plant for these elements in the marsh muck soils is discussed.

  9. Effect of testosterone administration on lead induced zincprotoporphyrin in blood concentration in castrated male rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo, A.A.E.; Zielhuis, R.L.

    1981-11-01

    The influence of testosterone propionate on the concentration of zincprotoporphyrin in blood (ZPP) of castrated lead treated rabbits was investigated. The experimental design allowed comparison of the relative ZPP increase (RZI) in testosterone treated and non testosterone treated rabbits. Testosterone was administered by subcutaneous injection of 3 mg/kg body weight/day for 7 consecutive days directly prior to the lead exposure, which was performed by subcutaneous injection of 0.50 mg lead acetate/kg body weight, three times a week for 7 weeks. No effect was found on the hemoglobin concentration (Hb) and hematocrit (Ht) and on the increase of body weight during the experiment. But the increase of RZI in the non testosterone treated rabbits was significantly steeper and earlier than in the testosterone treated group. The possible consequences of the findings had been further commented on.

  10. Melatonin reduces lead levels in blood, brain and bone and increases lead excretion in rats subjected to subacute lead treatment.

    Science.gov (United States)

    Hernández-Plata, Everardo; Quiroz-Compeán, Fátima; Ramírez-Garcia, Gonzalo; Barrientos, Eunice Yáñez; Rodríguez-Morales, Nadia M; Flores, Alberto; Wrobel, Katarzina; Wrobel, Kazimierz; Méndez, Isabel; Díaz-Muñoz, Mauricio; Robles, Juvencio; Martínez-Alfaro, Minerva

    2015-03-04

    Melatonin, a hormone known for its effects on free radical scavenging and antioxidant activity, can reduce lead toxicity in vivo and in vitro.We examined the effects of melatonin on lead bio-distribution. Rats were intraperitoneally injected with lead acetate (10, 15 or 20mg/kg/day) with or without melatonin (10mg/kg/day) daily for 10 days. In rats intoxicated with the highest lead doses, those treated with melatonin had lower lead levels in blood and higher levels in urine and feces than those treated with lead alone, suggesting that melatonin increases lead excretion. To explore the mechanism underlying this effect, we first assessed whether lead/melatonin complexes were formed directly. Electronic density functional (DFT) calculations showed that a lead/melatonin complex is energetically feasible; however, UV spectroscopy and NMR analysis showed no evidence of such complexes. Next, we examined the liver mRNA levels of metallothioneins (MT) 1 and 2. Melatonin cotreatment increased the MT2 mRNA expression in the liver of rats that received the highest doses of lead. The potential effects of MTs on the tissue distribution and excretion of lead are not well understood. This is the first report to suggest that melatonin directly affects lead levels in organisms exposed to subacute lead intoxication. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Lead elimination by ICRF 158 in rats after chronic lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Witting, U; Hultsch, E

    1981-02-01

    Lead elimination by ICRF 158, a lipophilic derivative of ethylene-diaminetetra-acetate (EDTA), was investigated in rats after chronic lead exposure. The animals had received a lead concentration of 550 ppm in their drinking water for 140 days. Subsequent treatment with ICRF 158 for 30 days led to increased mobilization and elimination of incorporated lead, and the lead-induced inhibition of hemosynthesis was removed. ICR 158 produced no renal damage in excess to lead-induced tubular nephrosis. Separate toxicity tests in mice demonstrated that is less toxic than CaNa/sub 2/EDTA. ICRF 158 does not form stable complexes with lead ions in vitro. The mechanism of action of this lipophilic EDTA derivative is compared to that of its hydrophilic correspondent, the chelating agent CaNa/sub 2/EDTA.

  12. 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.''

  13. Theoretical and experimental determination of mass attenuation coefficients of lead-based ceramics and their comparison with simulation

    Directory of Open Access Journals (Sweden)

    Vejdani-Noghreiyan Alireza

    2016-01-01

    Full Text Available Mass attenuation coefficient of lead-based ceramics have been measured by experimental methods and compared with theoretical and Monte Carlo simulation results. Lead-based ceramics were prepared using mixed oxide method and the X-ray diffraction analysis was done to evaluate the crystal structure of the produced handmade ceramics. The experimental results show good agreement with theoretical and simulation results. However at two gamma ray energies, small differences between experimental and theoretical results have been observed. By adding other additives to ceramics and observing the changes in the shielding properties such as flexibility, one can synthesize and optimize ceramics as a neutron shield.

  14. The effect of lead-based paint hazard remediation on blood lead levels of lead poisoned children in New York City

    International Nuclear Information System (INIS)

    Leighton, Jessica; Klitzman, Susan; Sedlar, Slavenka; Matte, Thomas; Cohen, Neal L.

    2003-01-01

    Despite the widespread use of lead paint hazard control for children with lead poisoning, few controlled studies that estimate the effect of such control on children's blood lead levels have been published. This retrospective follow-up study examined the effects of lead hazard remediation and its timing on the blood lead levels of lead-poisoned children. From the New York City child blood lead registry, 221 children were selected who had an initial blood lead level of 20-44 μg/dL between 1 July 1994 and 31 December 1996; were 6 months to 6 years of age; had a report of a follow-up blood lead test between 10 and 14 months after the initial test; had a lead-based paint hazard identified in the primary dwelling unit prior to the 10- to 14-month follow-up blood lead test; had resided or spent time at only one address with an identified lead-based paint hazard; and were not chelated. The decline in geometric mean blood lead levels from baseline to 10-14 months later was compared for children whose homes were remediated and whose homes were not remediated during the follow-up period. Regardless of remediation, geometric mean blood lead levels declined significantly from 24.3 μg/dL at the initial diagnosis to 12.3 μg/dL at the 10- to 14-month follow-up blood lead test (P<0.01). Among the 146 children whose homes were remediated the geometric mean blood lead levels declined 53% compared to 41% among the 75 children whose homes were not remediated by the follow-up blood lead test, a remediation effect of approximately 20% (P<0.01). After adjusting for potential confounders, the remediation effect was 11%, although it was no longer significant. Race was the only factor that appeared to confound the relationship: Black children had higher follow-up blood lead levels even after controlling for other factors, including the natural logarithm of the initial blood lead level. The effect of remediation appeared to be stronger for younger (10 to <36 months old) than for older (36

  15. 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.

  16. Work function of oxygen exposed lead and lead/indium alloy films

    International Nuclear Information System (INIS)

    Gundlach, K.H.; Hellemann, H.P.; Hoelzl, J.

    1982-01-01

    The effect of indium in superconducting tunnel junctions with lead/indium alloy base electrodes is investigated by measuring the vacuum work function of lead, indium, and lead/indium alloy films. It is found that the anomalous decrease of the work function of lead upon exposure to oxygen, explained by the penetration of oxygen into the inner surface of the lead film, is reversed into a slight increase in work function when some indium is added to the lead. This result indicates that the addition of indium provides a protection by suppressing the penetration of oxygen (and probably other gases) into the interior of the thin film

  17. 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)

  18. X-ray spectra and theoretical elastic properties of crystalline calcium silicate hydrates: comparison with cement hydrated gels

    Directory of Open Access Journals (Sweden)

    Ayuela, A.

    2010-09-01

    Full Text Available For 22 crystalline Calcium Silicates Hydrates, we have calculated their structure and their elastic properties by atomistic force field methods as well as simulate their Xray diffraction patterns. From the computed Young moduli, it can be suggested that the key parameters to determine the elastic properties of crystalline Calcium Silicate Hydrates are densities and water content. We have compared these trends with those of cementitious C-S-H gel and synthetic C-S-H type I as a function of their C/S ratios and nominal water content. Our comparison show that the experimentally suggested values of density and Young moduli for C-S-H gel lie in the range of the calculated CSH crystals. However, we conclude that a detailed correspondence might require investigating structurally within CSH gels the role of water and especially of Ca and Si sites through their C/S ratio.

    En este trabajo se han calculado para 22 Silicatos Cálcicos Hidratados cristalinos, su estructura y sus propiedades elásticas mediante métodos atomísticos “force field”, así como simulado sus espectros de difracción de rayos X. De los módulos de Young calculados se puede deducir, que los parámetros clave que determinan las propiedades elásticas de los Silicatos Cálcicos Hidratados cristalinos son la densidad y el contenido en agua. Nuestros resultados muestran que los valores experimentales de la densidad y de los módulos de Young para el gel C-S-H están dentro del rango de los cristales de CSH calculados. Sin embargo, podemos concluir que para establecer una correlación más directa sería necesario investigar el papel que juegan el agua y sobre todo el Ca y Si, mediante la relación C/S, en la estructura del gel CSH.

  19. Fibras de alta resistencia: Kevlar

    OpenAIRE

    CSIC-UZA - Instituto de Ciencia de Materiales de Aragón (ICMA)

    2010-01-01

    Trabajo presentado como material divulgativo a la II Escuela de Materiales: "Aplicaciones de los Cristales Líquidos", en el marco del XI Congreso Nacional de Materiales, organizado por la Sociedad Española de Materiales y el ICMA.

  20. Dispositivos electroópticos

    OpenAIRE

    CSIC-UZA - Instituto de Ciencia de Materiales de Aragón (ICMA)

    2010-01-01

    Trabajo presentado como material divulgativo a la II Escuela de Materiales: "Aplicaciones de los Cristales Líquidos", en el marco del XI Congreso Nacional de Materiales, organizado por la Sociedad Española de Materiales y el ICMA.

  1. 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.

  2. Detecting the Elusive P-Wave: A New ECG Lead to Improve the Recording of Atrial Activity.

    Science.gov (United States)

    Kennedy, Alan; Finlay, Dewar D; Guldenring, Daniel; Bond, Raymond R; McLaughlin, James

    2016-02-01

    In this study, we report on a lead selection method that was developed to detect the optimal bipolar electrode placement for recording of the P-wave. The study population consisted of 117 lead body surface potential maps recorded from 229 healthy subjects. The optimal bipolar lead was developed using the training set (172 subjects) then extracted from the testing dataset (57 subjects) and compared to other lead systems previously reported for improved recording of atrial activity. All leads were assessed in terms of P-wave, QRS, and STT root mean square (RMS). The P/QRST RMS ratio was also investigated to determine the atrioventricular RMS ratio. Finally, the effect of minor electrode misplacements on the P-lead was investigated. The P-lead discovered in this study outperformed all other investigated leads in terms of P-wave RMS. The P-lead showed a significant improvement in median P-wave RMS (93 versus 72 μV, p < 0.001) over the next best lead, Lead II. An improvement in QRS and STT RMS was also observed from the P-lead in comparison to lead II (668 versus 573 μV, p < 0.001) and (327 versus 196 μV, p < 0.001). Although P-wave RMS was reduced by incorrect electrode placement, significant improvement over Lead II was still evident. The P-lead improves P-wave RMS signal strength over all other investigated leads. Also the P-lead does not reduce QRS and STT RMS making it an appropriate choice for atrial arrhythmia monitoring. Given the improvement in signal-to-noise ratio, an improvement in algorithms that rely on P-wave analysis may be achieved.

  3. 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 ...

  4. The lead and lead-acid battery industries during 2002 and 2007 in China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.Y.; Li, A.J.; Finlow, D.E. [Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2009-06-01

    In the past 15 years, the center of the international lead market has shifted to China. China has become the largest producer of raw and refined lead, plus the largest consumer. This paper reviews the status of the lead and lead-acid battery industries in China, including lead mining, lead refining, secondary lead production, the lead-acid battery industry, new opportunities for lead-acid batteries, and the environmental problems associated with lead and lead-acid batteries. The output of raw and refined lead has increased annually in China, and now accounts for more than 30% of the world total. As a result of a change in the Chinese government's policy regarding the export of lead, plus an increase in the price of lead, the profits of Chinese lead manufacturers were significantly reduced, the trade deficit of the Chinese lead industry increased, the operating rates of lead smelter enterprises greatly reduced, and some small enterprises were forced to shut down. At the present time, an increasing number of enterprises have begun to produce secondary lead, and the scale of production has expanded from tens of tons to tens of thousands of tons. In 2006, the output of secondary lead in China reached 700,000 tons, but outdated technology and equipment limited development of the secondary lead industry. Because of serious pollution problems, raw material shortages, and fierce price competition in the battery market, changes in the development of the lead-acid battery industry have been dramatic; approximately one thousand medium-sized and small lead-acid battery producers have been closed in the past 3 years. The output of large lead-acid battery enterprises has not been reduced, however, as a result of their manufacturing technology and equipment being comparable to those in other advanced industrial countries. In China, the flourishing development of electric bicycles, electric tricycles, and photovoltaic energy systems should provide ongoing opportunities for

  5. The lead and lead-acid battery industries during 2002 and 2007 in China

    International Nuclear Information System (INIS)

    Chen, H.Y.; Li, A.J.; Finlow, D.E.

    2009-01-01

    In the past 15 years, the center of the international lead market has shifted to China. China has become the largest producer of raw and refined lead, plus the largest consumer. This paper reviews the status of the lead and lead-acid battery industries in China, including lead mining, lead refining, secondary lead production, the lead-acid battery industry, new opportunities for lead-acid batteries, and the environmental problems associated with lead and lead-acid batteries. The output of raw and refined lead has increased annually in China, and now accounts for more than 30% of the world total. As a result of a change in the Chinese government's policy regarding the export of lead, plus an increase in the price of lead, the profits of Chinese lead manufacturers were significantly reduced, the trade deficit of the Chinese lead industry increased, the operating rates of lead smelter enterprises greatly reduced, and some small enterprises were forced to shut down. At the present time, an increasing number of enterprises have begun to produce secondary lead, and the scale of production has expanded from tens of tons to tens of thousands of tons. In 2006, the output of secondary lead in China reached 700,000 tons, but outdated technology and equipment limited development of the secondary lead industry. Because of serious pollution problems, raw material shortages, and fierce price competition in the battery market, changes in the development of the lead-acid battery industry have been dramatic; approximately one thousand medium-sized and small lead-acid battery producers have been closed in the past 3 years. The output of large lead-acid battery enterprises has not been reduced, however, as a result of their manufacturing technology and equipment being comparable to those in other advanced industrial countries. In China, the flourishing development of electric bicycles, electric tricycles, and photovoltaic energy systems should provide ongoing opportunities for the

  6. A green lead hydrometallurgical process based on a hydrogen-lead oxide fuel cell.

    Science.gov (United States)

    Pan, Junqing; Sun, Yanzhi; Li, Wei; Knight, James; Manthiram, Arumugam

    2013-01-01

    The automobile industry consumed 9 million metric tons of lead in 2012 for lead-acid batteries. Recycling lead from spent lead-acid batteries is not only related to the sustainable development of the lead industry, but also to the reduction of lead pollution in the environment. The existing lead pyrometallurgical processes have two main issues, toxic lead emission into the environment and high energy consumption; the developing hydrometallurgical processes have the disadvantages of high electricity consumption, use of toxic chemicals and severe corrosion of metallic components. Here we demonstrate a new green hydrometallurgical process to recover lead based on a hydrogen-lead oxide fuel cell. High-purity lead, along with electricity, is produced with only water as the by-product. It has a >99.5% lead yield, which is higher than that of the existing pyrometallurgical processes (95-97%). This greatly reduces lead pollution to the environment.

  7. 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 ...

  8. 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 ...

  9. The effects of thiamin on lead metabolism: organ distribution of lead 203.

    Science.gov (United States)

    Kim, J S; Hamilton, D L; Blakley, B R; Rousseaux, C G

    1992-01-01

    The effect of thiamin on the organ distribution of lead was evaluated in CD-1 mice exposed intragastrically or intraperitoneally to a single dose of lead acetate (100 micrograms) containing 100 microCi lead 203. They were treated with either thiamin (25 or 50 mg/kg body weight), calcium ethylenediaminetetraacetic acid (CaEDTA) (50 mg/kg body weight), or combinations of thiamin and CaEDTA. The whole body retention and the organ distribution of lead 203 varied depending upon the route of lead administration, dose of thiamin and the specific treatment combination. Thiamin (25 or 50 mg/kg) treatment increased the whole body retention of both intragastric and intraperitoneal lead by approximately 10% in each instance. Calcium ethylenediaminetetraacetic acid, either alone or in combination with thiamin (50 mg/kg) reduced the whole body retention of lead by as much as 14% regardless of route of lead exposure. The relative retention of lead by the liver, kidney and spleen was greater in mice exposed to lead by the intragastric route. Regardless of route, CaEDTA in the combined treatment reduced the relative retention of lead in both the liver and kidney, whereas thiamin alone only reduced the retention of lead in the kidney. The results of this study indicate that thiamin in combination with CaEDTA alters the distribution and retention of lead in a manner which may have therapeutic application as it relates to chelation therapy. PMID:1423063

  10. Laser la luce estratta dagli atomi

    CERN Document Server

    Harbison, James P

    1999-01-01

    Dalla fisica pura alla luce pura ; la luce emessa dall'atomo ; l'invenzione del laser ; legami, bande e semiconduttori ; il laser a semiconduttore ; la produzione di cristalli semiconduttori "su misura" ; laser sempre più piccoli ; le frontiere dei laser.

  11. Lead shot from hunting as a source of lead in human blood

    International Nuclear Information System (INIS)

    Johansen, Poul; Pedersen, Henning Sloth; Asmund, Gert; Riget, Frank

    2006-01-01

    This study investigates the relationship between the intake of birds hunted with lead shot and the lead concentration in human blood. Fifty adult men from Nuuk, Greenland took part in the study. From September 2003 to June 2004 they regularly gave blood samples and recorded how many birds they ate. We found a clear relationship between the number of bird meals and blood lead and also a clear seasonal variation. The concentration was highest in mid-winter when bird consumption is at its highest. Blood lead was low (15 μg/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 μg/L (mean concentration). Concentrations depended on the frequency of bird meals: the more the bird meals, the higher the resulting blood lead. This clear relationship points to lead shot as the dominating lead source to people in Greenland. - Birds hunted with lead shot and consumed are a source of lead in human blood

  12. Lead shot from hunting as a source of lead in human blood

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk (Greenland); Asmund, Gert [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2006-07-15

    This study investigates the relationship between the intake of birds hunted with lead shot and the lead concentration in human blood. Fifty adult men from Nuuk, Greenland took part in the study. From September 2003 to June 2004 they regularly gave blood samples and recorded how many birds they ate. We found a clear relationship between the number of bird meals and blood lead and also a clear seasonal variation. The concentration was highest in mid-winter when bird consumption is at its highest. Blood lead was low (15 {mu}g/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 {mu}g/L (mean concentration). Concentrations depended on the frequency of bird meals: the more the bird meals, the higher the resulting blood lead. This clear relationship points to lead shot as the dominating lead source to people in Greenland. - Birds hunted with lead shot and consumed are a source of lead in human blood.

  13. The leaching of lead from lead-based paint in landfill environments.

    Science.gov (United States)

    Wadanambi, Lakmini; Dubey, Brajesh; Townsend, Timothy

    2008-08-30

    Lead leaching from lead-based paint (LBP) was examined using standardized laboratory protocols and tests with leachate from actual and simulated landfill environments. Two different LBP samples were tested; leaching solutions included leachates from three municipal solid waste (MSW) landfills and three construction and demolition (C&D) debris landfills. The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were also performed. Lead concentrations were many times higher using the TCLP compared to the SPLP and the landfill leachates. No significant difference (alpha=0.05) was observed in leached lead concentrations from the MSW landfill and C&D debris landfill leachates. The impact of other building materials present in LBP debris on lead leaching was examined by testing mixtures of LBP (2%) and different building materials (98%; steel, wood, drywall, concrete). The type of substrate present impacted lead leaching results, with concrete demonstrating the most dramatic impact; the lowest lead concentrations were measured in the presence of concrete under both TCLP and SPLP extractions.

  14. Prenatal exposure to lead in Spain: Cord blood levels and associated factors

    Energy Technology Data Exchange (ETDEWEB)

    Llop, Sabrina, E-mail: llop_sab@gva.es [Centre of Public Health Research (CSISP), Av Catalunya 21, 46020, Valencia (Spain); Carlos III Health Institute (ISCIII), 20220 Majadahonda, Madrid (Spain); CIBER de Epidemiologia y Salud Publica (CIBERESP), Doctor Aiguader 88, 8003 Barcelona (Spain); Aguinagalde, Xabier [Public Health Laboratory of Alava, Direccion de Salud Publica, Gobierno Vasco, Santiago 11, 01002, Vitoria-Gasteiz, Basque Country (Spain); Vioque, Jesus [CIBER de Epidemiologia y Salud Publica (CIBERESP), Doctor Aiguader 88, 8003 Barcelona (Spain); Universidad Miguel Hernandez, Av de Alicante KM 87, 03550, Sant Joan d' Alacant (Spain); Ibarluzea, Jesus [CIBER de Epidemiologia y Salud Publica (CIBERESP), Doctor Aiguader 88, 8003 Barcelona (Spain); Departamento de Sanidad Gobierno Vasco, Subdireccion de Salud Publica de Gipuzkoa, Avenida de Navarra 4, 20013 San Sebastian (Spain); Biodonostia, Instituto de Investigacion Biomedica, San Sebastian (Spain); Guxens, Monica [CIBER de Epidemiologia y Salud Publica (CIBERESP), Doctor Aiguader 88, 8003 Barcelona (Spain); Centre for Research of Environmental Epidemiology (CREAL), Doctor Aiguader 88, 8003 Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Doctor Aiguader 88, 8003 Barcelona (Spain); Casas, Maribel [Centre for Research of Environmental Epidemiology (CREAL), Doctor Aiguader 88, 8003 Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Doctor Aiguader 88, 8003 Barcelona (Spain); Murcia, Mario [Centre of Public Health Research (CSISP), Av Catalunya 21, 46020, Valencia (Spain); CIBER de Epidemiologia y Salud Publica (CIBERESP), Doctor Aiguader 88, 8003 Barcelona (Spain); Ruiz, Maria [Centre for Research of Environmental Epidemiology (CREAL), Doctor Aiguader 88, 8003 Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Doctor Aiguader 88, 8003 Barcelona (Spain); and others

    2011-05-01

    Introduction and Objective: Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother-child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood). Methods: A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blood by thermal decomposition, amalgation, and Atomic Absorption Spectrometry. Maternal sociodemographic, lifestyle and dietary factors were obtained by questionnaires during pregnancy. A multivariate logistic regression model was constructed. The dependent variable was a dichotomous lead level variable (detected vs no detected, i.e. {>=} vs < 2 {mu}g/dL). Results: A low percentage of cord blood samples with lead levels {>=} 2 {mu}g/dL were found (5.9%). Geometric mean and maximum were 1.06 {mu}g/dL and 19 {mu}g/dL, respectively. Smoking at the beginning of pregnancy, age, social class, weight gain during pregnancy, gravidity, and place of residence were the maternal factors associated with detectable cord blood lead levels. Mother's diet does not appear to be a determining factor of lead exposure. Nevertheless, daily intake of iron and zinc may act as a protective factor against having cord blood lead levels {>=} 2 {mu}g/dL. Conclusion: In the different regions of Spain taking part in this study, lead levels to which newborns are exposed are low. Mobilization of lead from bones may be the main contributor to the cord blood levels. - Research Highlights: {yields} Pb is a ubiquitous environmental pollutant with harmful effects on neurodevelopment. {yields} Cord blood Pb levels in

  15. Prenatal exposure to lead in Spain: Cord blood levels and associated factors

    International Nuclear Information System (INIS)

    Llop, Sabrina; Aguinagalde, Xabier; Vioque, Jesus; Ibarluzea, Jesus; Guxens, Monica; Casas, Maribel; Murcia, Mario; Ruiz, Maria

    2011-01-01

    Introduction and Objective: Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother-child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood). Methods: A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blood by thermal decomposition, amalgation, and Atomic Absorption Spectrometry. Maternal sociodemographic, lifestyle and dietary factors were obtained by questionnaires during pregnancy. A multivariate logistic regression model was constructed. The dependent variable was a dichotomous lead level variable (detected vs no detected, i.e. ≥ vs < 2 μg/dL). Results: A low percentage of cord blood samples with lead levels ≥ 2 μg/dL were found (5.9%). Geometric mean and maximum were 1.06 μg/dL and 19 μg/dL, respectively. Smoking at the beginning of pregnancy, age, social class, weight gain during pregnancy, gravidity, and place of residence were the maternal factors associated with detectable cord blood lead levels. Mother's diet does not appear to be a determining factor of lead exposure. Nevertheless, daily intake of iron and zinc may act as a protective factor against having cord blood lead levels ≥ 2 μg/dL. Conclusion: In the different regions of Spain taking part in this study, lead levels to which newborns are exposed are low. Mobilization of lead from bones may be the main contributor to the cord blood levels. - Research Highlights: → Pb is a ubiquitous environmental pollutant with harmful effects on neurodevelopment. → Cord blood Pb levels in Spanish newborn are low in

  16. An empirically-based model for the lift coefficients of twisted airfoils with leading-edge tubercles

    Science.gov (United States)

    Ni, Zao; Su, Tsung-chow; Dhanak, Manhar

    2018-04-01

    Experimental data for untwisted airfoils are utilized to propose a model for predicting the lift coefficients of twisted airfoils with leading-edge tubercles. The effectiveness of the empirical model is verified through comparison with results of a corresponding computational fluid-dynamic (CFD) study. The CFD study is carried out for both twisted and untwisted airfoils with tubercles, the latter shown to compare well with available experimental data. Lift coefficients of twisted airfoils predicted from the proposed empirically-based model match well with the corresponding coefficients determined using the verified CFD study. Flow details obtained from the latter provide better insight into the underlying mechanism and behavior at stall of twisted airfoils with leading edge tubercles.

  17. Shuttle Wing Leading Edge Root Cause NDE Team Findings and Implementation of Quantitative Flash Infrared Thermography

    Science.gov (United States)

    Burke, Eric R.

    2009-01-01

    Comparison metrics can be established to reliably and repeatedly establish the health of the joggle region of the Orbiter Wing Leading Edge reinforced carbon carbon (RCC) panels. Using these metrics can greatly reduced the man hours needed to perform, wing leading edge scanning for service induced damage. These time savings have allowed for more thorough inspections to be preformed in the necessary areas with out affecting orbiter flow schedule. Using specialized local inspections allows for a larger margin of safety by allowing for more complete characterizations of panel defects. The presence of the t-seal during thermographic inspection can have adverse masking affects on ability properly characterize defects that exist in the joggle region of the RCC panels. This masking affect dictates the final specialized inspection should be preformed with the t-seal removed. Removal of the t-seal and use of the higher magnification optics has lead to the most effective and repeatable inspection method for characterizing and tracking defects in the wing leading edge. Through this study some inadequacies in the main health monitoring system for the orbiter wing leading edge have been identified and corrected. The use of metrics and local specialized inspection have lead to a greatly increased reliability and repeatable inspection of the shuttle wing leading edge.

  18. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, R W; Kyger, J R; Biagioni, R N; Probst, S [Department of Chemistry, Southwest Missouri State University, 65804 Springfield, MO (United States); Boyer, R; Barke, K [Greene County Health Department, 65802 Springfield, MO (United States)

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r=0.91, P<0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  19. Corrosion by liquid lead and lead-bismuth: experimental results review and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinsuo [Los Alamos National Laboratory

    2008-01-01

    Liquid metal technologies for liquid lead and lead-bismuth alloy are under wide investigation and development for advanced nuclear energy systems and waste transmutation systems. Material corrosion is one of the main issues studied a lot recently in the development of the liquid metal technology. This study reviews corrosion by liquid lead and lead bismuth, including the corrosion mechanisms, corrosion inhibitor and the formation of the protective oxide layer. The available experimental data are analyzed by using a corrosion model in which the oxidation and scale removal are coupled. Based on the model, long-term behaviors of steels in liquid lead and lead-bismuth are predictable. This report provides information for the selection of structural materials for typical nuclear reactor coolant systems when selecting liquid lead or lead bismuth as heat transfer media.

  20. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA.

    Science.gov (United States)

    Sheets, R W; Kyger, J R; Biagioni, R N; Probst, S; Boyer, R; Barke, K

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150,000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r = 0.91, P lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  1. 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.)

  2. Measurement of the centrality dependence of charged particle spectra and RCP in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector at the LHC

    CERN Document Server

    The ATLAS collaboration

    2011-01-01

    Lead-lead collisions at the LHC provide an opportunity to study the properties of strongly interacting matter at the highest temperatures and energy densities ever achieved in the lab- oratory. In particular, jets are expected to be strongly quenched in the presence of the hot, dense medium, as illustrated by the centrality dependence of the dijet asymmetry already measured by ATLAS. Evidence of jet quenching can also be obtained from a measurement of inclusive charged particles at large transverse momentum, and in particular comparisons of spectral shapes between central and peripheral collisions. This note presents charged particle spectra as a function of centrality and rapidity, corrected for efficiency, fake tracks, secondaries and resolution. Using these, the ratio of scaled central to peripheral charged particle yields, RCP, is measured as a function of pT, centrality and pseudorapidity.

  3. The Latest from the LHC: The success of the lead ion run continues

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    The success of the lead ion run continues, with the 2010 target of 121 nominal bunches achieved on Sunday, 14 November, just 10 days after the first ions were injected into the LHC. Operation under these conditions continued until Wednesday morning, when it was interrupted for a scheduled stop to replenish the lead ion source. By this time a peak luminosity of 2.8 1025 cm-2 s-1 had been reached, and over 2 µb-1 had been delivered to the experiments.   Events recorded by the ALICE experiment from the first lead ion collisions. During the stop to replenish the source, the LHC switched back to proton operation so that studies with 50 ns and 75 ns bunch spacing could continue. These studies produced a wealth of valuable information about the behaviour of the machine with 75 ns bunch spacing, with up to 824 bunches circulating in one beam at 450 GeV, and 680 bunches in both beams. Important data were also taken with 50 ns bunch spacing, allowing comparison both with runs made before the ion ...

  4. Categorizing at the group-level in response to intragroup social comparisons : A self-categorization theory integration of self-evaluation and social identity motives

    NARCIS (Netherlands)

    Schmitt, MT; Branscombe, NR; Silvia, PJ; Garcia, DM; Spears, R

    2006-01-01

    Two experiments examined how people respond to upward social comparisons in terms of the extent to which they categorize the self and the source of comparison within the same social group. Self-evaluation maintenance theory (SEM) suggests that upward ingroup comparisons can lead to the rejection of

  5. Comparação de modelos matemáticos para descrição das curvas de dessorção de sementes de milho-doce Comparison of mathematical models for description of desorption curves of sweet corn seeds

    Directory of Open Access Journals (Sweden)

    Eduardo Fontes Araújo

    2001-07-01

    Full Text Available Este trabalho teve como objetivo determinar as curvas de dessorção das sementes de milho-doce (Zea mays L., cultivares Superdoce e Doce Cristal, e ajustar diferentes modelos matemáticos aos dados obtidos. As sementes das duas cultivares foram submetidas à dessorção em diversos níveis de temperatura (30, 40, 50 e 60°C, combinados com diferentes umidades relativas do ar (30, 40, 50 e 60%, até atingirem a umidade de equilíbrio. Os seguintes modelos matemáticos foram ajustados por análise de regressão: Henderson-Thompson, Chung-Pfost, Copace, Sigma-Copace, Sabbah e Smith. As sementes das duas cultivares apresentaram umidades de equilíbrio higroscópico semelhantes. Os valores da variância explicada e do desvio-padrão, bem como a distribuição dos resíduos, das duas cultivares, indicam que as equações de Chung-Pfost, Sabbah e Smith foram as que melhor se ajustaram aos dados experimentais, com pequena superioridade da primeira.This work had the goal to determine the desorption curves of seeds of sweet corn cultivars Superdoce and Doce Cristal, and to adjust mathematical models to obtained data. Corn seeds were submitted to desorption under different temperature conditions (30, 40, 50 and 60°C, associated with different relative humidity (30, 40, 50 and 60% until reaching the equilibrium humidity. The following models of regression analysis were adjusted to the experimental data: Henderson-Thompson, Chung-Pfost, Copace, Sigma-Copace, Sabbah and Smith. Seeds of both cultivars showed similar hygroscopic equilibrium. For both cultivars, the equations of Chung-Pfost, Sabbah and Smith, showed the best adjustments to the experimental data, with slight superiority of the first one.

  6. Lead dust in Broken Hill homes: effect of remediation on indoor lead levels.

    Science.gov (United States)

    Boreland, F; Lyle, D M

    2006-02-01

    This study was undertaken to determine whether home remediation effectively reduced indoor lead levels in Broken Hill, a long-established silver-lead-zinc mining town in outback Australia. A before-after study of the effect of home remediation on indoor lead levels was embedded into a randomized controlled trial of the effectiveness of remediation for reducing elevated blood lead levels in young children. Moist towelettes were used to measure lead loading (microg/m2) on internal windowsills and internal and entry floors of 98 homes; samples were collected before, immediately after, and 2, 4, 6, 8, and 10 months after remediation. Data were log(10) transformed for the analysis. Remediation reduced average indoor lead levels by approximately 50%, and lead levels remained low for the duration of the follow-up period (10 months). The greatest gains were made in homes with the highest initial lead levels; homes with low preremediation lead levels showed little or no benefit. Before remediation, homes located in areas with high soil lead levels or with "poor" dust proofing had higher lead levels than those in areas with lower soil lead levels or with "medium" or "good" dust proofing; these relative differences remained after remediation. There was no evidence that lead loading was reduced by an increased opportunity to become aware of lead issues. We conclude that remediation is an effective strategy for reducing the lead exposure of children living in homes with high indoor lead levels.

  7. Comparison between lead levels in dandelions grown in an ultra-clean lab environment (baseline) and those collected from the San Francisco Bay Area

    Science.gov (United States)

    Rojero, J.; Odigie, K. O.; Hibdon, S.; Flegal, A. R.

    2011-12-01

    This study is aimed at establishing the baseline (natural) levels of lead in dandelions (Taraxacum officinale) grown in an ultra-clean environment. Dandelions have been used extensively as biomonitors of environmental lead levels since their distribution is global and they can be easily collected. However, industrial lead contamination is so pervasive that even dandelions from the most remote areas in the world may be contaminated with industrial lead. Therefore, this work will test the hypothesis that "natural" lead levels in dandelions are lower than any previously published values - by growing them in a HEPA filtered air (Class 100) trace metal clean room with high purity (18 MΩ cm) water. Concentrations and isotopic compositions of lead in the clean-room grown dandelions will be compared to values in literature and to those of lead in dandelions collected from San Francisco Bay Area. Lead is a dense, ductile, and highly malleable metal that is found naturally in our environment. Due to its properties it is currently highly used in building construction, in ceramic glazes, lead chromate and in PVC plastic used to coat electrical cords. The uses of lead have included paint, leather tanning, and being used as an additive to gasoline prior to the mid 1970's, as well as others. Due to its many uses, humans are susceptible to lead regularly through various means of exposure from air, water and soil, often leading to lead toxicity.

  8. Maternal nutritional status during pregnancy and surma use determine cord lead levels in Karachi, Pakistan

    International Nuclear Information System (INIS)

    Janjua, Naveed Zafar; Delzell, Elizabeth; Larson, Rodney R.; Meleth, Sreelatha; Kabagambe, Edmond K.; Kristensen, Sibylle; Sathiakumar, Nalini

    2008-01-01

    Objectives: To estimate the umbilical cord blood lead levels (BLLs) of Pakistani neonates and to identify determinants for umbilical BLLs. Methods: We conducted a cross-sectional study of mothers and infants at one of the two obstetric units of two tertiary care hospitals in Karachi during January-August 2005. Information from 540 mothers selected randomly from those registered for delivery was obtained about their pregnancy, diet, and current and past lead exposures. We collected umbilical cord blood for lead levels analyzed using graphite furnace atomic absorption spectrophotometry. We computed geometric and arithmetic means. We performed multiple linear regression analysis to identify factors associated with log-transformed umbilical cord BLLs. We also performed logistic regression analysis to identify determinants of high lead cord BLLs (≥10 μg/dl). Results: The geometric mean cord BLL of the neonates was 9.6 μg/dl; arithmetic mean (S.D.) was 10.8 μg/dl (5.7) with a median of 9.7 μg/dl and a range of 1.8-48.9 μg/dl. Women who reported intake of less than 58.5 mg of elemental iron supplement per day during pregnancy had cord BLL of 10.0 μg/dl; in comparison those women who had higher iron intake had lower cord BLL (8.4 μg/dl). Those who used surma (an eye cosmetic) daily had higher cord BLL (11.5 μg/dl) as compared to those who used it less frequently (9.4 μg/dl). In multivariable linear regression model, higher iron intake, owning a car, and being in 2nd quartile of mid-arm circumference were associated with low lead levels while father's occupation in lead-based industry was associated with significantly higher umbilical cord BLLs. There was interaction of daily surma use and ethnicity. Geometric mean BLLs were varied among surma users by ethnicity. Conclusions: Umbilical cord BLLs are high in Karachi, Pakistan, in comparison to those in developed countries such as United States. Measures are needed to reduce fetal lead exposure to prevent adverse

  9. High human exposure to lead through consumption of birds hunted with lead shot

    International Nuclear Information System (INIS)

    Johansen, P.; Asmund, G.; Riget, F.

    2004-01-01

    Lead shot contaminates the edible parts of birds so that tolerable human lead intake is exceeded. - We assess lead contamination of Greenland seabirds killed with lead shot having studied thick-billed murre and common eider, the two most important species in the diet. The lead concentration is very high in meat of eiders killed with lead shot (mean 6.1 μg/g-wet wt, 95% CL 2.1-12). This level is about 44 times higher than in drowned eiders and eight times higher than in shot murres. Analyzing whole breasts instead of sub-samples reveals about seven times higher lead levels in birds' meat. We conclude that in some cases the lead intake by Greenland bird eaters will largely exceed the FAO/WHO tolerable lead intake guideline and that lead shot is a more important source of lead in the diet than previously estimated

  10. 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

  11. 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.

  12. Lead evaluation in blood of workers of batteries industries; Evaluacion de plomo en sangre de trabajadores de industrias de baterias

    Energy Technology Data Exchange (ETDEWEB)

    Valbuena P, John J; Duarte, Martha; Clara, Marciales

    2001-07-01

    In order to evaluate the occupational risk of exposure to lead of employees working in three small industries that recycle and manufacture acid lead batteries, the lead and zinc protoporphyrine (ZPP) blood content was determined. The determination was also performed on people not exposed in order to establish comparison values. Venous blood was collected in metal free heparinized glass tubes. Lead was analyzed by atomic absorption with graphite furnace and ZPP by fluorescence. According to Colombian legislation, it was found that around 31 % workers in this type of industries are in dangerous and intoxication exposure. It was also found that 91 % of workers exceed the level of 30 mg Pb/dL blood established as standard by the American Conference governmental Industrial Hygienists (ACGIH)

  13. Lead exposure from lead pellets: age-related accumulation in mute swans

    Energy Technology Data Exchange (ETDEWEB)

    Eskildsen, J.; Grandjean, P.

    1984-05-01

    In a cross-sectional study of adult swans and their successfully fledged young in Ringkobing Fjord, West Jutland, Denmark, 128 venous blood samples were taken during the moulting period and analyzed for lead. While the juveniles generally showed blood lead levels below 15 micrograms/100 ml (median, 11 micrograms/100 ml), the values were significantly higher in adults (median, 25 micrograms/100 ml). Adult females showed slightly higher levels than did adult males. None of the birds examined showed signs of acute lead toxicity, and increased blood levels in adults may reflect increased lead body burdens from previous ingestion of lead shot as gizzard stones.

  14. Stationary sources of airborne lead: a comparison of emissions data for southern California.

    Science.gov (United States)

    Harris, Allison R; Fifarek, Brian J; Davidson, Cliff I; Blackmon, Rebecca Lankey

    2006-04-01

    Estimates for the air releases of lead from stationary point sources are considered for the South Coast Air Basin of California. We have examined four databases published by U.S. Environmental Protection Agency, the California Air Resources Board, and the South Coast Air Quality Management District. Our analysis indicates that none of the databases includes every emitting facility in the South Coast Air Basin of California and that other discrepancies among the databases exist. Additionally, the data have been analyzed for temporal variation, and some of the California Air Resources Board data are not current. The South Coast Air Quality Management District inventory covers 12 times more facilities in 2001 than in 1996. From this analysis, we conclude that all four of the databases would benefit by sharing data, increasing transparency, analyzing uncertainty, and standardizing emission estimation methods.

  15. 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.

  16. Bioprotective effect of zinc in macro- and nanoaquachelate form on embryonal development of rats in conditions of lead intoxication

    Directory of Open Access Journals (Sweden)

    Beletskaya E.M.

    2013-06-01

    Full Text Available The article presents results of studied influence of low doses of lead and zinc (nanozinc on embryonal development in a la¬boratory experiment on rats. Negative influence of lead on pregnancy of laboratory animals, manifested in violation of the physiological dynamics of the rectal temperature and decrease in body weight gain was revealed. Embryotoxic effect of low doses of lead results in increased fetal mortality by 2.16 times compared to the control group of animals, de¬terioration of the morphometric indices of fetuses, violation of placentogenesis. Simultaneous injections of zinc on back¬ground of lead intoxication causes a protective effect on the body of pregnant rats and embryonal development of the offspring, more pronounced for zinc citrate, received by using aquananotehnology, as compared to zinc chloride. Thus, by morphometry indices, male fetuses were more sensitive to prenatal lead exposure in comparison to female fetuses.

  17. 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

  18. The economic consequences of elevated body-lead burdens in urban children

    International Nuclear Information System (INIS)

    Agree, M.D.

    1991-01-01

    The following analysis develops the theory and implementation of the observed behavior technique in an altruistic setting, to assess the health benefits of reducing environmental lead exposure in urban children. Three models are presented which allow for endogenous body lead burden, risk of irreversible neurological damages, and Bayesian information. Conditions are derived under which the observed behavior technique can be modified to value the health consequences of exposure to a general class of persistent micropollutants (PMP's): the heavy metals. Benefit expressions reflect the tradeoff between parental wealth and child health when children are exposed to low level doses of lead. The purpose is to derive exact measures of marginal welfare change associated with variations in child body lead burden, and to determine the conditions under which these measures will be functions of observable parameters. The analysis presents an entirely ex ante approach to the recovery of benefit estimates when PMP exposure involves risk of irreversible health damages. In doing so, an empirical estimate is also obtained for the parental value of child health information that is used in the revision of prior risk beliefs. Risk of chronic irreversible health effects in younger generations from environmental lead exposure may be experienced by a large share of metropolitan population in the US. Given the large numbers of possible victims, the aggregate social value of avoiding this risk is an important policy issues. Moreover, the value of health risk information is potentially important to the use of an information program as a policy instrument in reducing health risk because it would enable the comparison of societal benefits from an information program to the cost of it's implementation

  19. 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.

  20. Determination of lead associated with airborne particulate matter by flame atomic absorption and wave-length dispersive x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Talebi, S.M.

    1997-01-01

    The lead content of airborne particulate matter was determined by flame atomic absorption spectrometry (FAAS) following digestion with a mixture of nitric acid and hydrogen peroxide and also by wave-length dispersive x-ray fluorescence (WDXRF). The extraction procedure was checked by analyzing a standard reference material of airborne particulate matter (NIST, SRM -1648). It was concluded that lead can quantitatively (98%) be extracted from airborne particulate matter by the leaching process. A five-stage sequential extraction was performed to assess the potential mobility of lead associated with airborne particulate matter. Comparison of the airborne particulate lead measured by WDXRF to that measured by FAAS showed good agreement. The WDXRF method requires no time-consuming sample preparation or use of environmentally unfriendly solvents. The technique is suggested for direct determination of lead in airborne particulate matter in air pollution studies. (author)

  1. 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+}.

  2. Vector boson and Charmonium production in proton-lead and lead-lead collisions with ATLAS at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00241320; The ATLAS collaboration

    2016-01-01

    Electroweak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus should be sensitive to the nuclear modification of parton distribution functions (nPDFs). The in-medium modification of heavy charmonium states plays an important role in studying the hot and dense medium. The ATLAS detector, optimized to search for new physics in proton-proton collisions, is well equipped to measure Z and W bosons as well as quarkonium in the high occupancy environment produced in heavy ion collisions. Results from the ATLAS experiment on W and Z boson yields as a function of centrality, transverse momentum and rapidity, in lead-lead and proton-lead collisions are presented. Quarkonium results from proton-lead collisions are also presented.

  3. Age, genesis and exploration for mineral deposits: the possibilities offered by lead isotopes

    International Nuclear Information System (INIS)

    Marcoux, E.; Calvez, J.Y.

    1985-01-01

    After a brief theoretical survey of the subject, the paper discusses the assistance that lead isotopes can bring to solving problems of metallogenesis and mineral exploration. Lead isotopes act as a true geologic clock when radioactive decay of lead takes place in a closed U-Th-Pb system, or when these conditions have been recreated by homogenization of a large crustal segment. The lead clock is thus reliable for deposits whose process of formation was part of a hydrothermal event that affected a significant part of the crust, most importantly in island-arc volcanosedimentary deposits, much less so for deposits formed by spatially restricted hydrothermal activity such as the emplacement of veins. Very interesting possibilities are also to be found in the capacity of lead isotopes to act as geochemical tracers. In conjunction with paragenetic and gitologic studies, determination of the isotopic composition of lead allows the sources of metals to be identified and permits an approach to the understanding of inheritance phenomena in a mineral deposit or province. This information also assists in unravelling the successive metallogenic processes in a region, thus contributing to refinement of the concept of a metallogenic province. Lastly lead isotopes provide an additional factor in assessing the economic potential of a deposit undergoing exploration. The method is based on a comparison of the isotopic signature of the deposit with that of economic mineralization occuring elsewhere in the circa. Examples of stratiform deposits and the gold-bearing veins of Limousin are described. The application of this method to gossans can provide additional information to standard geochemistry and thus assist in grading of targets [fr

  4. Automated detection of heart ailments from 12-lead ECG using complex wavelet sub-band bi-spectrum features.

    Science.gov (United States)

    Tripathy, Rajesh Kumar; Dandapat, Samarendra

    2017-04-01

    The complex wavelet sub-band bi-spectrum (CWSB) features are proposed for detection and classification of myocardial infarction (MI), heart muscle disease (HMD) and bundle branch block (BBB) from 12-lead ECG. The dual tree CW transform of 12-lead ECG produces CW coefficients at different sub-bands. The higher-order CW analysis is used for evaluation of CWSB. The mean of the absolute value of CWSB, and the number of negative phase angle and the number of positive phase angle features from the phase of CWSB of 12-lead ECG are evaluated. Extreme learning machine and support vector machine (SVM) classifiers are used to evaluate the performance of CWSB features. Experimental results show that the proposed CWSB features of 12-lead ECG and the SVM classifier are successful for classification of various heart pathologies. The individual accuracy values for MI, HMD and BBB classes are obtained as 98.37, 97.39 and 96.40%, respectively, using SVM classifier and radial basis function kernel function. A comparison has also been made with existing 12-lead ECG-based cardiac disease detection techniques.

  5. A comparison on the heat load of HTS current leads with respect to uniform and non-uniform cross-sectional areas

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Hak; Nam, Seok Ho; Lee, Je Yull; Song, Seung Hyun; Jeon, Hae Ryong; Baek, Geon Woo; Ko, Tae Kuk [Yonsei University, Seoul (Korea, Republic of); Kang, Hyoung Ku [Korea National University of Transportation, Chungju (Korea, Republic of)

    2017-09-15

    Current lead is a device that connects the power supply and superconducting magnets. High temperature superconductor (HTS) has lower thermal conductivity and higher current density than normal metal. For these reasons, the heat load can be reduced by replacing the normal metal of the current lead with the HTS. Conventional HTS current lead has same cross-sectional area in the axial direction. However, this is over-designed at the cold-end (4.2 K) in terms of current. The heat load can be reduced by reducing this part because the heat load is proportional to the cross-sectional area. Therefore, in this paper, heat load was calculated from the heat diffusion equation of HTS current leads with uniform and non-uniform cross-sectional areas. The cross-sectional area of the warm-end (65K) is designed considering burnout time when cooling system failure occurs. In cold-end, Joule heat and heat load due to current conduction occurs at the same time, so the cross-sectional area where the sum of the two heat is minimum is obtained. As a result of simulation, current leads for KSTAR TF coils with uniform and non-uniform cross-sectional areas were designed, and it was confirmed that the non-uniform cross-sectional areas could further reduce the heat load.

  6. The influence of green microstructure and sintering parameters on precipitation process during copper-nickel-zinc ferrites sintering

    Directory of Open Access Journals (Sweden)

    Barba, Antonio

    2014-04-01

    Full Text Available Microstructural changes that occur during heat treatment of copper-nickel-zinc ferrites have been studied. The process of precipitation of the two types of crystals that occur during the sintering process has been analyzed. It is found that this process depends on dry relative density of the press specimens and on the following sintering parameters: sintering temperature, sintering time and cooling rate of the thermal cycle. Crystal precipitates characterization have been done by scanning electron microscopy (SEM, energy-dispersive X-ray (EDX analysis, X-ray diffraction (XRD, and X-ray photoelectron spectroscopy (XPS. These techniques have allowed to determine the nature of these crystals, which in this case correspond to zinc and copper oxides. It has been used two chemical reactions to explain the bulk precipitation and subsequent re-dissolution of these crystal precipitates during sintering.En este trabajo se han estudiado los cambios microestructurales que se producen durante el tratamiento térmico de las ferritas de cobre-níquel-cinc y se ha analizado el proceso de precipitación de los dos tipos de cristales que aparecen durante el proceso de sinterización. Se ha encontrado que este proceso depende de la densidad relativa en seco de las muestras compactadas y de las siguientes variables de la etapa de sinterización: temperatura y tiempo de sinterización y velocidad de enfriamiento. La caracterización de los cristales precipitados se ha realizado por microscopía electrónica de barrido (MEB, microanálisis por dispersión de energía de rayos X (EDX, difracción de rayos X (DRX, y espectroscopía de fotoelectrones de rayos X (XPS. Estas técnicas han permitido determinar la naturaleza de estos cristales, que en este caso corresponden a los óxidos de cinc y de cobre. Se han propuesto dos reacciones químicas que permiten explicar el proceso de precipitación y la posterior re-disolución de estos cristales precipitados durante la

  7. 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

  8. Role of Airborne Lead in Increased Body Burden of Lead in Hartford Children*

    Science.gov (United States)

    Lepow, Martha L.; Bruckman, Leonard; Rubino, Robert A.; Markowitz, Steven; Gillette, Marybeth; Kapish, Janet

    1974-01-01

    The ingestion of airborne lead fallout is the mechanism responsible for increased lead body burdens found in 10 urban Connecticut children. The mean indoor lead levels found in housedust was 11,000 μg/g; highest concentrations occurred on windowsills and in floor dust. The mean lead content of Hartford street dirt was 1,200 μg/g; levels were highest near the street and next to the buildings. The mean lead concentration of hand samples taken from the subject children was 2,400 μg/g; the mean weight of hand samples was 11 mg. The concentration of lead in dirt and househould dust was high enough to theoretically result in excessive lead accumulation in young children who are putting their dusty, dirty hands in their mouths during play. While we believe that lead emitted from automobiles contributes significantly to air, dirt and dust lead levels the environmental impact of reducing or eliminating lead from gasoline is not yet completely understood. PMID:4133903

  9. Lead-free, bronze-based surface layers for wear resistance in axial piston hydraulic pumps

    Energy Technology Data Exchange (ETDEWEB)

    Vetterick, Gregory Alan [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Concerns regarding the safety of lead have provided sufficient motivation to develop substitute materials for the surface layer on a thrust bearing type component known as a valve plate in axial piston hydraulic pumps that consists of 10% tin, 10% lead, and remainder cooper (in wt. %). A recently developed replacement material, a Cu-10Sn-3Bi (wt.%) P/M bronze, was found to be unsuitable as valve plate surface layer, requiring the development of a new alloy. A comparison of the Cu-1-Sn-10Pb and Cu-10Sn-3Bi powder metal valve plates showed that the differences in wear behavior between the two alloys arose due to the soft phase bismuth in the alloy that is known to cause both solid and liquid metal embrittlement of copper alloys.

  10. 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 ...

  11. The effects of thiamin on lead metabolism: organ distribution of lead 203.

    OpenAIRE

    Kim, J S; Hamilton, D L; Blakley, B R; Rousseaux, C G

    1992-01-01

    The effect of thiamin on the organ distribution of lead was evaluated in CD-1 mice exposed intragastrically or intraperitoneally to a single dose of lead acetate (100 micrograms) containing 100 microCi lead 203. They were treated with either thiamin (25 or 50 mg/kg body weight), calcium ethylenediaminetetraacetic acid (CaEDTA) (50 mg/kg body weight), or combinations of thiamin and CaEDTA. The whole body retention and the organ distribution of lead 203 varied depending upon the route of lead a...

  12. Managing Evolving Business Workflows through the Capture of Descriptive Information

    CERN Document Server

    Gaspard, S; Dindeleux, R; McClatchey, R; Gaspard, Sebastien; Estrella, Florida

    2003-01-01

    Business systems these days need to be agile to address the needs of a changing world. In particular the discipline of Enterprise Application Integration requires business process management to be highly reconfigurable with the ability to support dynamic workflows, inter-application integration and process reconfiguration. Basing EAI systems on model-resident or on a so-called description-driven approach enables aspects of flexibility, distribution, system evolution and integration to be addressed in a domain-independent manner. Such a system called CRISTAL is described in this paper with particular emphasis on its application to EAI problem domains. A practical example of the CRISTAL technology in the domain of manufacturing systems, called Agilium, is described to demonstrate the principles of model-driven system evolution and integration. The approach is compared to other model-driven development approaches such as the Model-Driven Architecture of the OMG and so-called Adaptive Object Models.

  13. 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.

  14. 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.

  15. Changes in operant behavior of rats exposed to lead at the accepted no-effect level.

    Science.gov (United States)

    Gross-Selbeck, E; Gross-Selbeck, M

    1981-11-01

    After weaning, male and female Wistar rats were fed a daily diet containing 1 g lead acetate/kg food until a level of about 20 micrograms/100 mL blood was obtained. The male rats were subjected to the different behavioral tests, whereas the females were mated to untreated males and further exposed until weaning of the offspring. Behavioral testing of the male offspring was performed between 3 and 4 months of age. General behavior of both groups was tested in the open-field task including locomotion, local movements, and emotionality. The conditioned instrumental behavior was tested in the Skinner box from simple to more complex programs. The blood-lead level was measured by flameless atomic absorption spectrometry. No behavioral changes became apparent in the open-field task and in the preliminary operant training. In the more complex programs (DRH = Differential Reinforcement of High Rates), the rats exposed to lead after weaning showed slight changes of DRH performance. By contrast, in pre- and neonatally exposed animals, DRH performance was significantly increased, although blood-lead levels had returned to normal at the time of testing. A comparison of lead effects in animals to possible effects in man is discussed in this paper, and it is concluded that lead exposure to man at doses which presently are suggested to be innocuous may result in subclinical functional changes of the central nervous system.

  16. Activity of lead deposited in the tissues in conditions of occupational lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    The author measured urinary excretion of delta-aminolevulinic acid (ALA), coproporphyrins and lead, before and after administration of chelating agents (CaEDTA and D-penicillamine) to subjects presenting clinical symptoms of lead poisoning and workers occupationally exposed to lead. He found a great increase in lead following its mobilization in subjects with lead poisoning who had previously shown a high level of haemoglobin precursors and a low urinary lead level. In these subjects ALA excretion was proportional to the duration of exposure. A correlation was found between urinary ALA and coproporphyrins, on the one hand, and lead excretion after provocation, on the other. This suggests that the lead deposited in the tissues, as well as that in circulation, retains all its activity.

  17. Comparison of a suspended radiation protection system versus standard lead apron for radiation exposure of a simulated interventionalist.

    Science.gov (United States)

    Marichal, Daniel A; Anwar, Temoor; Kirsch, David; Clements, Jessica; Carlson, Luke; Savage, Clare; Rees, Chet R

    2011-04-01

    To evaluate the radiation protective characteristics of a system designed to enhance operator protection while eliminating weight to the body and allowing freedom of motion. Radiation doses to a mock interventionalist were measured with calibrated dosimeters in a clinical interventional suite. A standard lead apron (SLA; Pb equivalent, 0.5 mm) was compared with a suspended radiation protection system (ZeroGravity; Zgrav) that shields from the top of the head to the calves (except the right arm and left forearm) with a complex overhead motion system that eliminates weight on the operator and allows freedom of motion. Zgrav included a suspended lead apron with increased lead equivalency, greater length, proximal left arm and shoulder coverage, and a wraparound face shield of 0.5 mm Pb equivalency. A 26-cm-thick Lucite stack (ie, mock patient) created scatter during 10 controlled angiography sequences of 120 exposures each. Parameters included a field of view of 40 cm, table height of 94 cm, 124 cm from the tube to image intensifier, 50 cm from the image center to operator, 66 kVp, and 466-470 mA. Under identical conditions, average doses (SLA vs Zgrav) were 264 versus 3.4 (ratio, 78) to left axilla (P < .001), 456 versus 10.2 (ratio, 45) to left eye (P < .001), 379.4 versus 6.6 (ratio, 57) to right eye (P < .005), and 18.8 versus 1.2 (ratio, 16) to gonad (P < .001). Relative to a conventional lead apron, the Zgrav system provided a 16-78-fold decrease in radiation exposure for a mock interventionalist in a simulated clinical setting. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  18. Health care of people at work. Workers exposed to lead. I. Inorganic lead

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, H.A.

    1978-01-01

    The risks associated with exposure to inorganic lead and the means by which these risks can be minimized are outlined. Lead is used to make a variety of metal products, the grids and oxides in storage batteries, pigments, chemicals, and also for lead plating. In the United States about 70% of the total lead consumption is related to transportation. Uptake of inorganic lead is by ingestion and inhalation. About 90% of the total body burden of lead is contained within the skeletal tissues. Lead is excreted in the kidney, in sweat, and in milk. Toxic effects are directed against the blood, the nervous system, and the kidney. Symptoms of lead poisoning are abdominal pain, constipation, vomiting, asthenia, paresthesia, psychological symptoms, and diarrhea. Physical and biological monitoring can serve to protect workers. Diagnosis of lead poisoning is not easy. Treatment involves removal from exposure and/or treatment with a chelating agent.

  19. 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…

  20. Advanced Small-Safe Long-Life Lead Cooled Reactor Cores for Future Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hyeong; Hong, Ser Gi [Kyung Hee University, Seoul (Korea, Republic of)

    2014-10-15

    One of the reasons for use of the lead or lead-bismuth alloy coolants is the high boiling temperature that avoids the possibility of coolant voiding. Also, these coolants are compatible with air, steam, and water. Therefore, intermediate coolant loop is not required as in the sodium cooled reactors 3. Lead is considered to be more attractive coolant than lead-bismuth alloy because of its higher availability, lower price, and much lower amount of polonium activity by factor of 104 relatively to lead. On the other hand, lead has higher melting temperature of 601K than that of lead-bismuth (398K), which narrows the operating temperature range and also leads to the possibility of freezing and blockage in fresh cores. Neutronically, the lead and lead-bismuth have very similar characteristics to each other. The lead-alloy coolants have lower moderating power and higher scattering without increasing moderation for neutrons below 0.5MeV, which reduces the leakage of the neutrons through the core and provides an excellent reflecting capability for neutrons. Due to the above features of lead or lead-alloy coolants, there have been lots of studies on the small lead cooled core designs. In this paper, small-safe long-life lead cooled reactor cores having high discharge burnup are designed and neutronically analyzed.. The cores considered in this work rates 110MWt (36.7MWe). In this work, the long-life with high discharge burnup was achieved by using thorium or depleted uranium blanket loaded in the central region of the core. Also, we considered a reference core having no blanket for the comparison. This paper provides the detailed neutronic analyses for these small long-life cores and the detailed analyses of the reactivity coefficients and the composition changes in blankets. The results of the core design and analyses show that our small long-life cores can be operated without refueling over their long-lives longer than 45EFPYs (Effective Full Power Year). In this work

  1. 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…

  2. 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

  3. Relationships of maternal blood lead and disorders of pregnancy to neonatal birthweight.

    Science.gov (United States)

    Kaul, P P; Srivastava, R; Srivastava, S P; Kamboj, M; Chand, S

    2002-12-01

    Transient complications of pregnancy (anemia, toxemia, proteinuria, arterial hypertension and hyperemesis) were studied in pregnant women from the general population reporting to local hospitals. Comparison of blood lead levels (PbB) was made between women with normal pregnancies and those with complications. Significantly higher PbB were found in women with pregnancy complications as compared to those with normal pregnancies. Increments in the PbB levels were accompanied by statistically significant decrements in neonate birthweights. Complications of pregnancy may be induced by higher PbB and may also compound the adverse effects of decrements of neonate birthweights

  4. Lead theft--a study of the "uniqueness" of lead from church roofs.

    Science.gov (United States)

    Bond, John W; Hainsworth, Sarah V; Lau, Tien L

    2013-07-01

    In the United Kingdom, theft of lead is common, particularly from churches and other public buildings with lead roofs. To assess the potential to distinguish lead from different sources, 41 samples of lead from 24 church roofs in Northamptonshire, U.K, have been analyzed for relative abundance of trace elements and isotopes of lead using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry, respectively. XRF revealed the overall presence of 12 trace elements with the four most abundant, calcium, phosphorus, silicon, and sulfur, showing a large weight percentage standard error of the mean of all samples suggesting variation in the weight percentage of these elements between different church roofs. Multiple samples from the same roofs, but different lead sheets, showed much lower weight percentage standard errors of the mean suggesting similar trace element concentrations. Lead isotope ratios were similar for all samples. Factors likely to affect the occurrence of these trace elements are discussed. © 2013 American Academy of Forensic Sciences.

  5. 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)

  6. A comparison of automatic fall detection by the cross-product and magnitude of tri-axial acceleration

    International Nuclear Information System (INIS)

    Chao, Pei-Kuang; Chan, Hsiao-Lung; Chen, Yu-Chuan; Tang, Fuk-Tan; Wong, May-Kuen

    2009-01-01

    Falling is an important problem in the health maintenance of people above middle age. Portable accelerometer systems have been designed to detect falls. However, false alarms induced by some dynamic motions, such as walking and jumping, are difficult to avoid. Acceleration cross-product (AC)-related methods are proposed and examined by this study to seek solutions for detecting falls with less motion-evoked false alarms. A set of tri-axial acceleration data is collected during simulated falls, posture transfers and dynamic activities by wireless sensors for making methodological comparisons. The performance of fall detection is evaluated in aspects of parameter comparison, threshold selection, sensor placement and post-fall posture (PP) recruitment. By parameter comparison, AC leads to a larger area under the receiver operating characteristic (ROC) curve than acceleration magnitude (AM). Three strategies of threshold selection, for 100% sensitivity (Sen100), for 100% specificity (Spe100) and for the best sum (BS) of sensitivity and specificity, are evaluated. Selecting a threshold based on Sen100 and BS leads to more practicable results. Simultaneous data recording from sensors in the chest and waist is performed. Fall detection based on the data from the chest shows better global accuracy. PP recruitment leads to lower false alarm ratios (FR) for both AC- and AM-based methods

  7. Quantification of atmospheric lead emissions from 70 years of leaded petrol consumption in Australia

    Science.gov (United States)

    Kristensen, Louise Jane

    2015-06-01

    Lead is a persistent pollutant and the subject of many environmental studies, yet, in Australia, the extent of atmospheric lead emissions from the use of leaded petrol is unquantified. This paper details the first comprehensive account of leaded petrol sales and its lead concentrations over the 70 years of use in Australia. The resulting atmospheric lead emissions are calculated to provide the most complete understanding of the volume of lead released to the Australian continent from the consumption of leaded petrol. Atmospheric emissions of lead to the entire Australian continent from leaded petrol are calculated to total 240,510 tonnes over seven decades of use, peaking at 7869 tonnes in 1974. Total emissions for individual states and territories range from 1745 to 67,893 tonnes, with New South Wales responsible for the largest emissions. The effect of regulations on allowable concentrations of tetraethyl-lead additives are observed in the reduction of lead emissions in New South Wales and Victoria. The consequences to human health and the environment of leaded petrol consumption in Australia's populous cities are examined against historical air quality data and blood lead levels.

  8. 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

  9. 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

  10. 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

  11. SELF-ORGANIZATION OF LEAD SULFIDE QUANTUM DOTS INTO SUPERSTRUCTURES

    Directory of Open Access Journals (Sweden)

    Elena V. Ushakova

    2014-11-01

    Full Text Available The method of X-ray structural analysis (X-ray scattering at small angles is used to show that the structures obtained by self-organization on a substrate of lead sulfide (PbS quantum dots are ordered arrays. Self-organization of quantum dots occurs at slow evaporation of solvent from a cuvette. The cuvette is a thin layer of mica with teflon ring on it. The positions of peaks in SAXS pattern are used to calculate crystal lattice of obtained ordered structures. Such structures have a primitive orthorhombic crystal lattice. Calculated lattice parameters are: a = 21,1 (nm; b = 36,2 (nm; c = 62,5 (nm. Dimensions of structures are tens of micrometers. The spectral properties of PbS QDs superstructures and kinetic parameters of their luminescence are investigated. Absorption band of superstructures is broadened as compared to the absorption band of the quantum dots in solution; the luminescence band is slightly shifted to the red region of the spectrum, while its bandwidth is not changed much. Luminescence lifetime of obtained structures has been significantly decreased in comparison with the isolated quantum dots in solution, but remained the same for the lead sulfide quantum dots close-packed ensembles. Such superstructures can be used to produce solar cells with improved characteristics.

  12. Penetration of a magnetic field into superconducting lead and lead-indium alloys

    International Nuclear Information System (INIS)

    Egloff, C.; Raychaudhuri, A.K.; Rinderer, L.

    1983-01-01

    The temperature dependence of the magnetic field penetration depth of superconducting lead and lead-indium alloys has been studied over the temperature range between about 2 K and T/sub c/. Data are analyzed in terms of the microscopic theory. The difficulties of a unique analysis of the penetration data are pointed out and a strategy for the analysis is discussed. The penetration depth at T = 0K for pure lead is determined as 522 A. This value, though higher than the previously accepted value for lead, is nevertheless consistent with the strong coupling character of lead

  13. 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

  14. EP toxicity testing of lead to resolve disposition of radioactively contaminated lead

    International Nuclear Information System (INIS)

    Larsen, M.M.; Boehmer, A.M.

    1986-03-01

    The Department of Energy (DOE), in its efforts to comply with the requirements of the Resource Conservation and Recovery Act (RCRA) of 1976, is concerned with hazardous waste which is also radioactively contaminated. There are no existing facilities to treat or dispose of these wastes. One such waste is lead, which is extensively used in the nuclear industry as shielding. This paper reports the results of leach testing of lead (both solid lead samples and lead shot) to resolve questions as to whether or not radioactively contaminated waste lead must be treated as a hazardous waste. The results of these tests showed that: some samples passed the leach test. Results of development efforts performed to date to recycle lead and those planned for the future are included in this report

  15. Elution of lead from lead zirconate titanate ceramics to acid rain

    Science.gov (United States)

    Tsurumi, Takaaki; Takezawa, Shuhei; Hoshina, Takuya; Takeda, Hiroaki

    2017-10-01

    The amount of lead that eluted from lead zirconate titanate (PZT) ceramics to artificial acid rain was evaluated. Four kinds of PZT ceramics, namely, pure PZT at MPB composition, CuO-added PZT, PZT with 10 mol % substitution of Ba for Pb, and CuO-added PZT with 10 mol % substitution of Ba for Pb, were used as samples of the elution test. These PZT ceramics of 8 mm2 and 1.1-1.2 mm thickness were suspended in 300 ml of H2SO4 solution of pH 4.0. The concentration of lead eluted from PZT was in the range from 0.2 to 0.8 ppm. It was found that both liquid phase formation by the addition of CuO and the substitution of Ba for Pb were effective to reduce the amount of lead that eluted. By fitting the leaching out curve with a classical equation, a master curve assuming no sampling effect was obtained. The lead concentration evaluated from the amount of lead that eluted from a commercial PZT plate to H2SO4 solution of pH 5.3 was almost the same as the limit in city water. It is concluded that PZT is not harmful to health and the environment and the amount of lead that eluted from PZT can be controlled by modifying PZT composition.

  16. MODELING OF THE THERMAL BEHAVIOR OF METALS DURING ...

    African Journals Online (AJOL)

    30 juin 2012 ... Laboratoire LENREZA, Département de Physique, Faculté des ... Le milieu actif dans les lasers solides est un verre ou un cristal. ... modélisation numérique est un outil de prédiction du comportement des matériaux pour.

  17. Long range correlations, leading particle spectrum and correlations with leading particles

    International Nuclear Information System (INIS)

    Ilgenfritz, E.M.

    1976-05-01

    The unitary cluster emission model by de Groot and Ruijgrok is discussed as an approach to understand the leading particle behaviour. Consequences of the model concerning co--rrelations between leading particles and produced particles in the central region are considered. No satisfactory agreement was found. Production of leading clusters is argued for being an essential feature of these correlations. (author)

  18. Comparative toxicity of tetra ethyl lead and lead oxide to earthworms, Eisenia fetida (Savigny)

    International Nuclear Information System (INIS)

    Venkateswara Rao, J.; Kavitha, P.; Padmanabha Rao, A.

    2003-01-01

    Leaded gasoline contains tetra ethyl lead (TEL) as an antiknocking agent, which produces major amounts of lead oxide in automobile exhaust along with traces of TEL. To minimize the lead contamination, methyl tertiary butyl ether (MTBE) is used as a substitute for producing unleaded gasoline. It has become increasingly apparent that young children are highly susceptible to the harmful effects of lead. Hence, a study was carried out to monitor lead toxicity in soil, using adult earthworms (Eisenia fetida, Savigny). Leaded gasoline (TEL) and lead oxide are 383- and 211-fold more toxic than unleaded gasoline (MTBE) in 7 days of exposure and 627- and 290-fold more toxic in 14 days, respectively. Results indicate that the presence of TEL in leaded gasoline and lead oxide has a significant effect on behavior, morphology, and histopathology of earthworms. Absorption of TEL into the tissues is comparatively less than that of lead oxide but toxic effects were severe. Rupture of the cuticle, extrusion of coelomic fluid and inflexible metameric segmentation were observed, causing desensitization of the posterior region leading to fragmentation in earthworms

  19. Lead-resistant Providencia alcalifaciens strain 2EA bioprecipitates Pb+2 as lead phosphate.

    Science.gov (United States)

    Naik, M M; Khanolkar, D; Dubey, S K

    2013-02-01

    A lead-resistant bacteria isolated from soil contaminated with car battery waste were identified as Providencia alcalifaciens based on biochemical characteristics, FAME profile and 16S rRNA sequencing and designated as strain 2EA. It resists lead nitrate up to 0·0014 mol l(-1) by precipitating soluble lead as insoluble light brown solid. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometric analysis (SEM-EDX) and X-ray diffraction spectroscopy (XRD) revealed extracellular light brown precipitate as lead orthophosphate mineral, that is, Pb(9) (PO(4))(6) catalysed by phosphatase enzyme. This lead-resistant bacterial strain also demonstrated tolerance to high levels of cadmium and mercury along with multiple antibiotic resistance. Providencia alcalifaciens strain 2EA could be used for bioremediation of lead-contaminated environmental sites, as it can efficiently precipitate lead as lead phosphate. © 2012 The Society for Applied Microbiology.

  20. Lead isotopes in soils near five historic American lead smelters and refineries

    International Nuclear Information System (INIS)

    Rabinowitz, Michael B.

    2005-01-01

    This survey of soil lead in the vicinity of old industrial sites examines how the stable isotope patterns vary among the sites according to the sources of the lead ore processed at each site. Lead smelters and refineries, which closed down decades ago, are the basis of this investigation. Samples were taken from near five old factory sites in Collinsville and Alton (Illinois), Ponderay (Idaho), East Chicago (Indiana) and Omaha (Nebraska). Historical records were searched for accounts of the sources of the lead. Lead concentrations were measured by atomic absorption flame spectrophotometry, and stable isotopic analysis was done by plasma ionization mass spectrometry. At every site visited, remnants of the old factories, in terms of soil lead pollution, could be found. In spite of potential complications of varying smelter feedstock sourced from mines of different geological age, it was possible to match the isotopic patterns in the soils with the documented sources of the ores. The Collinsville and Alton sites resembled Missouri lead. The Ponderay value was higher than major Bunker Hill, Idaho deposits, but closer to the minor, nearby Oreille County, Washington ores. Mostly Utah ore was used in East Chicago. The Omaha soil reflects lead from Mexico, Colorado and Montana

  1. The void nucleation mechanism within lead phase during spallation of leaded brass

    Science.gov (United States)

    Yang, Yang; Wang, Can; Chen, Xingzhi; Chen, Kaiguo; Hu, Haibo; Fu, Yanan

    2018-07-01

    The incipient spall behaviours of Cu-34%Zn-3%Pb leaded brass samples with annealed and cryogenic-treated conditions were loaded using one-stage light gas gun experiments. The effect of Pb-phase on dynamic damage nucleation in leaded brass specimens was investigated by means of optical microscopy, scanning electron microscopy and x-ray computer tomography. It was found that the voids of incipient spall were mainly nucleated in the interior of the lead (no tensile stress would be produced within lead according to the impact theory) instead of nucleated at the phase interface as expected by quasi-static damage fracture theory. A nucleation model is proposed in the present work that is the asymmetry high compression zones in the centre of the lead-phase were formed by the rarefaction wave convergence effects of matrix/quasi-spherical lead interface, which caused adiabatic temperature rise that exceeded melting point of lead due to severe plastic deformation, finally led to local melting and void nucleation. In addition, the spall strength and damage rate increased with the increase in the Pb-phase number.

  2. Lead toxicity on hematological parameters in workers with occupational exposure to lead

    International Nuclear Information System (INIS)

    Dursun, N.; Koese, K.

    1998-01-01

    The effects of lead on hematological parameters were studied in lead exposed male workers occupied for 17.84+-4.22 years in a metal powder producing factory in Kayseri, Turkey and control male workers in same city. Blood lead and plasma zinc levels were measured by Atomic Absorption Spectrophotometry (AAS) and hematological parameters by Culture Counter S. The lead exposure workers had higher lead levels (13.81+- 9.21 mug/dl) as compared to control subjects (2.37+-0.10 mug/dl). No difference was observed in the plasma zinc levels of both groups. As indices of lead exposure, red blood cell (RBC) counts, hemoglobin (Hb), and hematocrit (Hct) values significantly decreased. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) significantly increased except MCV. There was also an increase in MCV, but it was not significant. (author)

  3. The utility of Pinus sylvestris L. in dendrochemical investigations: pollution impact of lead mining and smelting in Darley Dale, Derbyshire, UK.

    Science.gov (United States)

    Lageard, J G A; Howell, J A; Rothwell, J J; Drew, I B

    2008-05-01

    This research investigates atmospheric pollution from an isolated and increasingly productive lead-smelting site by examining the dendrochemistry of Pinus sylvestris growing in the local environment and at control sites. Tree increment cores and soil in the rooting environment were analysed for lead content. Inter-site comparisons of lead-in-soil suggest that contamination of the soil may be a less important pathway for lead inclusion within wood than pathways via bark or needles. Levels of lead-in-wood (up to 38mgkg(-1)) are at the upper end of those previously reported. There is evidence of radial translocation of lead towards the heartwood and variability in intra-site dendrochemical records. Mean site lead-in-wood records can however be related to a well-documented pollution chronology and also suggest the importance of local topography in the dispersal and deposition of particulate lead. This study demonstrates that P. sylvestris can be used to estimate the scale and timing of past pollution episodes in similar environmental contexts to those investigated at Darley Dale, where precisely dated pollution chronologies are lacking.

  4. Monetary benefits of preventing childhood lead poisoning with lead-safe window replacement

    OpenAIRE

    Nevin, Rick; Jacobs, David / E.; Berg, Michael; Cohen, Jonathan

    2007-01-01

    Previous estimates of childhood lead poisoning prevention benefits have quantified the present value of some health benefits, but not the costs of lead paint hazard control or the benefits associated with housing and energy markets. Because older housing with lead paint constitutes the main exposure source today in the U.S., we quantify health benefits, costs, market value benefits, energy savings, and net economic benefits of lead-safe window replacement (which includes paint stabilization ...

  5. Pacemaker lead fracture without an increase in lead impedance caused by cardiac fibroma

    Directory of Open Access Journals (Sweden)

    Daisuke Sato

    2013-12-01

    Full Text Available We report the case of a 64-year-old man who had a permanent pacemaker with a unipolar silicone electrode positioned in the right ventricle in 1989 for sinus node dysfunction. On a routine checkup in June 2011, a 28-mm-diameter mass was discovered, which appeared to adhere to the tricuspid valve and the ventricular lead. The size of the mass did not change for the next 6 months, and the lead impedance was maintained at around 500–600 Ω. Because pacing failure was observed in January 2012, he underwent an urgent pacemaker check; however, the lead impedance was found not to have increased greatly (689 Ω. Nevertheless, the pacemaker lead was noted to be fractured at the tricuspid level. His echocardiogram showed new severe tricuspid regurgitation and a floating mass around the lead. We extracted the fractured lead, enucleated the tumor, replaced the tricuspid valve, and placed an epicardial lead. Macroscopic examination revealed that the tumor surrounded the fractured lead and covered the stump. Pathological examination revealed that the tumor was composed of fibrous connective tissue. We presumed that electric current continued to flow through the stump of the fractured unipolar lead to the generator, and this might have caused the limited increase in lead impedance.

  6. Highly reversible lead-carbon battery anode with lead grafting on the carbon surface

    KAUST Repository

    Yin, Jian; Lin, Nan; Zhang, Wenli; Lin, Zheqi; Zhang, Ziqing; Wang, Yue; Shi, Jun; Bao, Jinpeng; Lin, Haibo

    2018-01-01

    A novel C/Pb composite has been successfully prepared by electroless plating to reduce the hydrogen evolution and achieve the high reversibility of the anode of lead-carbon battery (LCB). The deposited lead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Because lead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogen evolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead. Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge–discharge reversibility, which is attributed to the good connection between carbon additives and lead that has been stuck on the surface of C/Pb composite during the preparation process. The addition of C/Pb composite maintains a solid anode structure with high specific surface area and power volume, and thereby, it plays a significant role in the highly reversible lead-carbon anode.

  7. Highly reversible lead-carbon battery anode with lead grafting on the carbon surface

    KAUST Repository

    Yin, Jian

    2018-03-27

    A novel C/Pb composite has been successfully prepared by electroless plating to reduce the hydrogen evolution and achieve the high reversibility of the anode of lead-carbon battery (LCB). The deposited lead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Because lead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogen evolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead. Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge–discharge reversibility, which is attributed to the good connection between carbon additives and lead that has been stuck on the surface of C/Pb composite during the preparation process. The addition of C/Pb composite maintains a solid anode structure with high specific surface area and power volume, and thereby, it plays a significant role in the highly reversible lead-carbon anode.

  8. PSF interlaboratory comparison

    International Nuclear Information System (INIS)

    Kellogg, L.S.; Lippincott, E.P.

    1982-01-01

    Two experiments for interlaboratory verification of radiometric analysis methods have been conducted with dosimeters irradiated in the Oak Ridge Research Reactor (ORR) Poolside Facility (PSF) Surveillance Dosimeter Measurement Facility (SDMF). In a preliminary analysis of data supplied by the six participants, biases as large as 60% were observed which could lead to errors of this general magnitude in reported surveillance capsule fluence values. As a result of these comparisons, problems were identified and the spread in final values was greatly reduced. Relative agreement among the final results reported by four of the laboratories now appears to be satisfactory (the non-fission dosimeter results generally falling within +-5% and the fission dosimeter results within +-10%), but improvement is required in order to routinely meet Reactor Vessel Material Surveillance Program goals

  9. Seasonality and trend in blood lead levels of New York State children

    Directory of Open Access Journals (Sweden)

    Talbot Thomas O

    2004-06-01

    Full Text Available Abstract Background Environmental exposure to lead remains a significant health problem for children. The costs of lead exposure in children are estimated to be considerably more than other childhood diseases of environmental origin. While long-term trends in blood lead levels (BLLs among children are declining, seasonal variation persists. Cross-sectional studies have found a peak in summer months. Part of this variation may be due to increased exposure to lead paint on window sills and through increased contact with soils containing lead during the summer. The current study represents the largest published population-based study on seasonality and trends in the BLLs of children to date. In addition, the results offer a comparison of recent data on seasonality of BLLs in New York State children, to studies conducted over the past three decades. Methods 262,687 New York State children born between 1994 and 1997 were screened for blood lead within 2 weeks of their first or second birthdays. Time series analyses of blood lead data from these children were conducted to study the seasonality and trends of BLLs. Results Children's blood lead values showed a distinct seasonal cycle on top of a long-term decreasing trend. The geometric mean BLL declined by about 24% for children born between 1994 and 1997. The prevalence of elevated BLLs in two-year-olds was almost twice that in one-year-olds over the time period. Nearly twice as many children had elevated BLLs in the late summer compared to late winter/early spring. In this and previous cross-sectional studies, the amount of seasonality as a proportion of the mean ranged between 15% and 30%. Conclusion Pediatricians should be aware of the seasonality of BLLs. For example, if a two-year-old receives a borderline result during the winter, it is possible that the levels would have been higher if he had been tested during the summer. However, physicians should continue to screen children at their normally

  10. Impact of lead tolerant plant growth promoting rhizobacteria on growth, physiology, antioxidant activities, yield and lead content in sunflower in lead contaminated soil.

    Science.gov (United States)

    Saleem, Muhammad; Asghar, Hafiz Naeem; Zahir, Zahir Ahmad; Shahid, Muhammad

    2018-03-01

    Present study was conducted to evaluate the effect of lead tolerant plant growth promoting rhizobacteria (LTPGPR) on growth, physiology, yield, antioxidant activities and lead uptake in sunflower in soil contaminated with lead under pot conditions. Three pre-characterized LTPGP strains (S2 (Pseudomonas gessardii strain BLP141), S5 (Pseudomonas fluorescens A506) and S10 (Pseudomonas fluorescens strain LMG 2189)) were used to inoculate sunflower growing in soil contaminated with different levels (300, 600 and 900 mg kg -1 ) of lead by using lead nitrate salt as source of lead. Treatments were arranged according to completely randomized design with factorial arrangements. At harvesting, data regarding growth attributes (root shoot length, root shoot fresh and dry weights), yield per plant, physiological attributes (Chlorophyll 'a', 'b' and carotenoids content), antioxidant activities (Ascorbate peroxidase, catalase, superoxide dismutase and glutathione reductase), proline and malanodialdehyde content, and lead content in root, shoot and achenes of sunflower were recorded. Data were analysed by standard statistical procedures. Results showed that lead contamination reduced the plants growth, physiology and yield at all levels of lead stress. But application of LTPGPR in soil contaminated with lead improved plant growth, physiology, yield, and antioxidant activities, proline, and reduced the malanodialdehyde content (that is reduced by the application of different strains in lead contamination) of sunflower as compared to plants grown in soil without inoculation. Inoculation also promoted the uptake of lead in root, shoots and reduced the uptake of lead in achenes of plants as compared to plants in lead contamination without inoculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Temporal stability of blood lead concentrations in adults exposed only to environmental lead

    Energy Technology Data Exchange (ETDEWEB)

    Delves, H T; Sherlock, J C; Quinn, M J

    1984-08-01

    The temporal stability of blood lead concentrations of 21 health adults (14 men and 7 women) exposed only to environmental lead was assessed by analysis of 253 blood specimens collected serially over periods from 7 to 11 months. The women had lower blood lead concentrations (mean 8.5, range 7.4-10.8 micrograms/100 ml) than did the men (mean 12.2, range 8.6-15.8 micrograms/100 ml). These are within the expected ranges for non-occupationally exposed persons. Blood lead concentrations in the serial specimens from both men and women changed very little over the study period, with standard deviations of less than 0.5 micrograms/100 ml for the majority of individual mean concentrations: for all except low subjects the standard deviations were less than 0.8 micrograms/100 ml. Two subjects showed significant changes in blood lead concentrations during the study. A temporary increase in oral lead intake was identified for one of these subjects. In the absence of substantial changes in lead exposure blood lead levels in adults are remarkably stable and for their environmental monitoring a single blood lead concentration is an excellent biological indicator.

  12. Hydrogen isotope double differential production cross sections induced by 62.7 MeV neutrons on a lead target

    International Nuclear Information System (INIS)

    Kerveno, M.; Haddad, F.; Eudes, Ph.; Kirchner, T.; Lebrun, C.; Slypen, I.; Meulders, J.P.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Louvel, M.; Lefebvres, F.; Hilaire, S.; Koning, A.J.

    2002-01-01

    Double differential hydrogen isotope production cross sections have been extracted in 62.7 MeV neutron induced reactions on a lead target. The angular distribution was measured at eight angles from 20 deg. to 160 deg. allowing the extraction of angle-differential, energy differential, and total production cross sections. A first set of comparisons with several theoretical calculations is also presented

  13. 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...

  14. Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

    Science.gov (United States)

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-04-01

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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

  16. Towards a 20 kA high temperature superconductor current lead module using REBCO tapes

    Science.gov (United States)

    Heller, R.; Bagrets, N.; Fietz, W. H.; Gröner, F.; Kienzler, A.; Lange, C.; Wolf, M. J.

    2018-01-01

    Most of the large fusion devices presently under construction or in operation consisting of superconducting magnets like EAST, Wendelstein 7-X (W7-X), JT-60SA, and ITER, use high temperature superconductor (HTS) current leads (CL) to reduce the cryogenic load and operational cost. In all cases, the 1st generation HTS material Bi-2223 is used which is embedded in a low-conductivity matrix of AgAu. In the meantime, industry worldwide concentrates on the production of the 2nd generation HTS REBCO material because of the better field performance in particular at higher temperature. As the new material can only be produced in a multilayer thin-film structure rather than as a multi-filamentary tape, the technology developed for Bi-2223-based current leads cannot be transferred directly to REBCO. Therefore, several laboratories are presently investigating the design of high current HTS current leads made of REBCO. Karlsruhe Institute of Technology is developing a 20 kA HTS current lead using brass-stabilized REBCO tapes—as a further development to the Bi-2223 design used in the JT-60SA current leads. The same copper heat exchanger module as in the 20 kA JT-60SA current lead will be used for simplicity, which will allow a comparison of the newly developed REBCO CL with the earlier produced and investigated CL for JT-60SA. The present paper discusses the design and accompanying test of single tape and stack REBCO mock-ups. Finally, the fabrication of the HTS module using REBCO stacks is described.

  17. Determining tissue-lead levels in large game mammals harvested with lead bullets: human health concerns.

    Science.gov (United States)

    Tsuji, L J S; Wainman, B C; Jayasinghe, R K; VanSpronsen, E P; Liberda, E N

    2009-04-01

    Recently, the use of lead isotope ratios has definitively identified lead ammunition as a source of lead exposure for First Nations people, but the isotope ratios for lead pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden; however, few studies have determined if lead bullet fragments are present in big game carcasses. We found elevated tissue-lead concentrations (up to 5,726.0 microg/g ww) in liver (5/9) and muscle (6/7) samples of big game harvested with lead bullets and radiographic evidence of lead fragments. Thus, we would advise that the tissue surrounding the wound channel be removed and discarded, as this tissue may be contaminated by lead bullet fragments.

  18. Lead intoxication in dogs: risk assessment of feeding dogs trimmings of lead-shot game.

    Science.gov (United States)

    Høgåsen, Helga R; Ørnsrud, Robin; Knutsen, Helle K; Bernhoft, Aksel

    2016-07-25

    Expanding lead-based bullets, commonly used for hunting of big game, produce a scattering of lead particles in the carcass around the wound channel. Trimmings around this channel, which are sometimes fed to dogs, may contain lead particles. The aim of this study was to assess potential health effects of feeding dogs such trimmings. Lead ingestion most commonly causes gastrointestinal and neurological clinical signs, although renal, skeletal, haematological, cardiovascular and biochemical effects have also been reported. Experimental data indicate that a daily dose of around 1 mg lead as lead acetate/kg body weight for ten days may be considered as a Lowest Observed Effect Level in dogs. Acute toxicity documentation from the Centers for Disease Control and Prevention indicates 300 mg/kg body weight as the lowest dose of lead acetate causing death in dogs after oral ingestion. Our assessment suggests that dogs fed trimmings of lead-shot game may be affected by the amounts of lead present, and that even deadly exposure could occasionally occur. The intestinal absorption of lead from bullets was assumed to be 10-80 % of that of lead acetate, reflecting both the variability in particle size and uncertainty about the bioavailability of metallic lead in dogs. Despite data gaps, this study indicates that feeding dogs trimmings of lead-shot game may represent a risk of lead intoxication. More research is needed to assess the exact consequences, if lead-based bullets are still to be used. Meanwhile, we recommend that trimmings close to the wound channel should be made inaccessible to dogs, as well as to other domestic or wild animals.

  19. 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.

  20. Eryptosis in lead-exposed workers

    International Nuclear Information System (INIS)

    Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

    2014-01-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca 2+ ] i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca 2+ ], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers showed higher PS

  1. Eryptosis in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Dorado, Itzel-Citlalli [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Hernández, Gerardo [Section of Methodology of Science, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Quintanar-Escorza, Martha-Angelica [Faculty of Medicine, UJED, Durango, DGO (Mexico); Maldonado-Vega, María [CIATEC, León, GTO (Mexico); Rosas-Flores, Margarita [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Calderón-Salinas, José-Víctor, E-mail: jcalder@cinvestav.mx [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico)

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

  2. 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

  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. 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.

  5. 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.

  6. Comparison of pregnancy rates in PCOS patients undergoing clomiphene citrate and IUI treatment with different leading follicular sizes.

    Science.gov (United States)

    Seckin, Berna; Pekcan, Meryem Kuru; Bostancı, Esra Isci; Inal, Hasan Ali; Cicek, Mahmut Nedim

    2016-04-01

    The objective of the study was to compare the pregnancy rates in PCOS patients undergoing clomiphene citrate (CC) and intrauterine insemination (IUI) treatment with different leading follicular sizes. A total of 358 infertile women with PCOS who underwent 563 clomiphene citrate and IUI treatment cycles were included in this prospective study. Treatment cycles were divided into three groups according to leading follicular size on the day of hCG administration: Group I: follicular size 17-18 mm (n = 177), Group II: 19-22 mm (n = 321), and Group III : >22 mm (n = 65). Pregnancy rates were evaluated. Treatment outcomes of the groups were further analyzed related to endometrial thickness measurement on the day of hCG. For this purpose, cycles were placed into three subgroups as follows: endometrial thickness 9 mm. There was no statistically significant difference in clinical pregnancy rate per cycle between the groups (8.5, 10, and 9.2 % for Group I, II, and III, respectively, p = 0.86). In further analyses related to endometrial thickness, no significant difference was also found in pregnancy rate among the groups. This results suggest that pregnancy rate is not related to leading follicle size on the day of hCG administration in PCOS patients treated with CC and IUI. In addition, pregnancy rate in women with different follicular sizes is not influenced by the endometrial thickness.

  7. Measurements of spin-lattice relaxation time in mixed alkali halide crystals

    International Nuclear Information System (INIS)

    Tannus, A.

    1983-01-01

    Using magneto-optic techniques the ground state spin-lattice relaxation times (T1) of 'F' centers in mixed Alkali Halide cristals (KCl-KBr), was studied. A computer assisted system to optically measure short relaxation times (approx. = 1mS), was described. The technique is based on the measurement of the Magnetic Circular Dicroism (MCD) presented by F centers. The T1 magnetic field dependency at 2 K (up to 65 KGauss), was obtained as well as the MCD spectra for different relative concentration at the mixed matrices. The theory developed by Panepucci and Mollenauer for F centers spin-lattice relaxation in pure matrices was modified to explain the behaviour of T1 in mixed cristals. The Direct Process results (T approx. = 2.0 K) compared against that theory shows that the main relaxation mecanism, up to 25 KGauss, continues to be phonon modulation of the hiperfine iteraction between F electrons and surrounding nuclei. (Author) [pt

  8. The Caves of Naica: a decade of research; Las Cuevas de Naica: una decada de investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Gazquez, F.; Calaforra, J. M.; Porti, P.; Badino, G.

    2016-07-01

    The caves of the Naica Mine have been the subject of study by scientists from up to seven counties over the past decade. Up to fifty research works have published to date, most relating to the origin of the giant selenite crystals of the Cueva de los Cristales. Nevertheless, a great deal of knowledge has been generated about other relevant aspects of the Naica system. This paper puts together the vast information available about the Naica caves, from the discovery of the Cueva de los Cristales in 2000 to the more recent investigations addressing mineralogy, microclimatology and the use of gypsum speleothems as a palaeo-environmental proxy. Special attention has been paid to novel research lines that have started to use the speleothems of Naica as a study case, particularly in fields such as Astrobiology and Planetary geology. Moreover, the conservation challenges which these caves will face in the near future as consequence of the end of mining activities have also been addressed in this article. (Author)

  9. The Caves of Naica: a decade of research

    International Nuclear Information System (INIS)

    Gazquez, F.; Calaforra, J. M.; Porti, P.; Badino, G.

    2016-01-01

    The caves of the Naica Mine have been the subject of study by scientists from up to seven counties over the past decade. Up to fifty research works have published to date, most relating to the origin of the giant selenite crystals of the Cueva de los Cristales. Nevertheless, a great deal of knowledge has been generated about other relevant aspects of the Naica system. This paper puts together the vast information available about the Naica caves, from the discovery of the Cueva de los Cristales in 2000 to the more recent investigations addressing mineralogy, microclimatology and the use of gypsum speleothems as a palaeo-environmental proxy. Special attention has been paid to novel research lines that have started to use the speleothems of Naica as a study case, particularly in fields such as Astrobiology and Planetary geology. Moreover, the conservation challenges which these caves will face in the near future as consequence of the end of mining activities have also been addressed in this article. (Author)

  10. Blanket comparison and selection study. Volume I

    International Nuclear Information System (INIS)

    1983-10-01

    The objectives of the Blanket Comparison and Selection Study (BCSS) can be stated as follows: (1) Define a small number (approx. 3) of blanket design concepts that should be the focus of the blanket R and D program. A design concept is defined by the selection of all materials (e.g., breeder, coolant, structure and multiplier) and other major characteristics that significantly influence the R and D requirements. (2) Identify and prioritize the critical issues for the leading blanket concepts. (3) Provide the technical input necessary to develop a blanket R and D program plan. Guidelines for prioritizing the R and D requirements include: (a) critical feasibility issues for the leading blanket concepts will receive the highest priority, and (b) for equally important feasibility issues, higher R and D priority will be given to those that require minimum cost and short time

  11. Glasses impregnated with lead for radiation shielding

    International Nuclear Information System (INIS)

    Abd El Monem, A.M.; Kansouh, W.A.; Megahid, R.M.; Ismail, A.L.; Awad, E.M.

    2005-01-01

    The attenuation properties of glasses with different concentration of lead have been investigated for the attenuation of gamma-rays from cesium-137 and for total gamma rays using a beam of neutrons and gamma rays emitted from californium-252 source. Measurements have been performed using a gamma-ray spectrometer with Nal(T1) detector for gamma-rays emitted from 137 Cs and a neutron/gamma spectrometer with stilbene scintillator for measurement of total gamma-rays from 252 Cf neutron source. The latter applied the pulse shape discrimination technique to distinguish between recoil proton and recoil electron pulses. The obtained results given the form displayed pulse height spectra and attenuation relations which were used to derive the linear attenuation coefficient (μ), and the mass attenuation coefficient (mu/p) of the investigated glasses. In addition, calculations were performed to determine the attenuation properties of glass shields under investigation using XCOM code given by the others. A comparison of the shielding properties of these glasses with some standard shielding materials indicated that, the investigated glasses process the shielding advantages required for different nuclear technology applications

  12. Re-analysis as a Comparison of Constructions

    Directory of Open Access Journals (Sweden)

    Jochen Gläser

    2000-12-01

    Full Text Available An interesting methodological aspect of secondary analysis is that it enables comparisons between constructions that constitute qualitative data analysis. This comparison is even more focused if a reanalysis is conducted, that means an analysis that reexamines both the primary study's data and the primary study's research question. In this article, a reanalysis is described that used interviews from the archive at the Special Collaborative Centre 186 (Sfb 186. One of the primary study's results was formulated as a hypothesis and subsequently "tested" by conducting a qualitative content analysis of the interviews. A comparison of primary study and reanalysis reveals critical decisions which may lead the data analyses to different results. These decisions are usually made implicitly and will show up only if contradictions between results are explained. As a second result of the comparison, typical threats to primary and secondary analyses are discussed. Primary studies seem to suffer from a "closure pressure", that it is a necessity to make sense of the data at all costs. This may stimulate researchers to close gaps in their data by speculation and to neglect contradicting evidence. Secondary analyses are thematically and methodically restricted by the primary study's data collection. Finally, the reanalysis confirmed that it is possible to use interviews from archives: The losses of information due to archiving and anonymisation seemed to have no significant influence on the reanalysis. URN: urn:nbn:de:0114-fqs0003257

  13. 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 ...

  14. 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.

  15. 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

  16. On a constant arising in the analysis of bit comparisons in quickselect

    African Journals Online (AJOL)

    A (real) constant that appears as the factor of the leading term of the average number of bit comparisons required by quickselect, and was originally given in terms of complex numbers, is expressed using real numbers alone. A further representation is derived which is converging very quickly. Methods include residue ...

  17. Leading SU(3)-breaking corrections to the baryon magnetic moments in chiral perturbation theory.

    Science.gov (United States)

    Geng, L S; Camalich, J Martin; Alvarez-Ruso, L; Vacas, M J Vicente

    2008-11-28

    We calculate the baryon magnetic moments using covariant chiral perturbation theory (chiPT) within the extended-on-mass-shell renormalization scheme. By fitting the two available low-energy constants, we improve the Coleman-Glashow description of the data when we include the leading SU(3)-breaking effects coming from the lowest-order loops. This success is in dramatic contrast with previous attempts at the same order using heavy-baryon chiPT and covariant infrared chiPT. We also analyze the source of this improvement with particular attention to the comparison between the covariant results.

  18. Preventive maintenance basis: Volume 24 -- Battery -- flooded lead-acid (lead-calcium, lead antimony, plante). Final report

    International Nuclear Information System (INIS)

    Worledge, D.; Hinchcliffe, G.

    1997-12-01

    US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. This document provides a program of preventive maintenance (PM) tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, system engineers, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

  19. Lead-Binding Proteins: A Review

    Directory of Open Access Journals (Sweden)

    Harvey C. Gonick

    2011-01-01

    Full Text Available Lead-binding proteins are a series of low molecular weight proteins, analogous to metallothionein, which segregate lead in a nontoxic form in several organs (kidney, brain, lung, liver, erythrocyte. Whether the lead-binding proteins in every organ are identical or different remains to be determined. In the erythrocyte, delta-aminolevulinic acid dehydratase (ALAD isoforms have commanded the greatest attention as proteins and enzymes that are both inhibitable and inducible by lead. ALAD-2, although it binds lead to a greater degree than ALAD-1, appears to bind lead in a less toxic form. What may be of greater significance is that a low molecular weight lead-binding protein, approximately 10 kDa, appears in the erythrocyte once blood lead exceeds 39 μg/dL and eventually surpasses the lead-binding capacity of ALAD. In brain and kidney of environmentally exposed humans and animals, a cytoplasmic lead-binding protein has been identified as thymosin β4, a 5 kDa protein. In kidney, but not brain, another lead-binding protein has been identified as acyl-CoA binding protein, a 9 kDa protein. Each of these proteins, when coincubated with liver ALAD and titrated with lead, diminishes the inhibition of ALAD by lead, verifying their ability to segregate lead in a nontoxic form.

  20. 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

  1. EPA Leads the Way on Lead Exposure Science and Risk Management

    Science.gov (United States)

    EPA researchers have developed a modeling approach that improves our understanding of the relationship between lead concentrations of various sources (drinking water, soil and dust, food, and air) and children’s blood-lead levels.

  2. 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 ...

  3. 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

  4. EMERGING TECHNOLOGY BULLETIN: RECLAMATION OF LEAD FROM SUPERFUND WASTE MATERIAL USING SECONDARY LEAD SMELTERS

    Science.gov (United States)

    This process involves incorporating lead-contaminated Superfund waste with the regular feed to a secondary lead smelter. Since secondary lead smelters already recover lead from recycled automobile batteries, it seems likely that this technology could be used to treat waste from ...

  5. Two cases of acute lead poisoning due to occupational exposure to lead.

    Science.gov (United States)

    Ogawa, Masanori; Nakajima, Yoshiaki; Kubota, Ryuichi; Endo, Yoko

    2008-04-01

    We experienced two cases of acute lead poisoning due to occupational exposure to lead. The patients were engaged in stripping off antirust compounds including Pb from a bridge and re-painting it at the same work place. Both patients exhibited colic, arthralgia, and anemia. Blood lead levels were 73.1 microg/dl and 96.3 microg/dl. Intravenous CaEDTA chelation therapy was therefore performed. After chelation, blood lead levels decreased and symptoms gradually disappeared. Although the patients were working with protective equipment, the workplace was in the mountains and there was no water for washing. The patients were thus unable to washing their hands and faces. We assume that they swallowed lead dust left on their hands and faces when they removed their clothing, and believe that this poisoning occurred due to lack of knowledge sufficient for protection.

  6. Transvenous versus open chest lead placement for resynchronization therapy in patients with heart failure: comparison of ventricular electromechanical synchronicity.

    Science.gov (United States)

    Zhang, Hai-Bo; Meng, Xu; Han, Jie; Li, Yan; Zhang, Ye; Jiang, Teng-Yong; Zhao, Ying-Xin; Zhou, Yu-Jie

    2017-04-01

    Transvenous lead placement is the standard approach for left ventricular (LV) pacing in cardiac resynchronization therapy (CRT), while the open chest access epicardial lead placement is currently the most frequently used second choice. Our study aimed to compare the ventricular electromechanical synchronicity in patients with heart failure after CRT with these two different LV pacing techniques. We enrolled 33 consecutive patients with refractory heart failure secondly to dilated cardiomyopathy who were eligible for CRT in this study. Nineteen patients received transvenous (TV group) while 14 received open chest (OP group) LV lead pacing. Intra- and inter-ventricular electromechanical synchronicity was assessed by tissue Doppler imaging (TDI) before and one year after CRT procedure. Before CRT procedure, the mean QRS-duration, maximum time difference to systolic peak velocity among 12 left ventricle segments (LV Ts-12), standard deviation of time difference to systolic peak velocity of 12 left ventricle segments (LV Ts-SD), and inter-ventricular mechanical delay (IVMD) in OP and TV group were 166 ± 17 ms and 170 ± 21 ms, 391 ± 42 ms and 397 ± 36 ms, 144 ± 30 ms and 148 ± 22 ms, 58 ± 25 ms and 60 ± 36 ms, respectively (all P > 0.05). At one year after the CRT, the mean QRS-duration, LV Ts-12, LV Ts-SD, and IVMD in TV and OP group were 128 ± 14 ms and 141 ± 22 ms ( P = 0.031), 136 ± 37 ms and 294 ± 119 ms ( P = 0.023), 50 ± 22 ms and 96 ± 34 ms ( P = 0.015), 27 ± 11 ms and 27 ± 26 ms ( P = 0.86), respectively. The LV lead implantation procedure time was 53.4 ± 16.3 min for OP group and 136 ± 35.1 min for TV group ( P = 0.016). The mean LV pacing threshold increased significantly from 1.7 ± 0.6 V/0.5 ms to 2.3 ± 1.6 V/0.5 ms ( P open chest access of LV pacing for CRT leads to better improvement of the intraventricular synchronization.

  7. Arkansas People Participating in Lead Education (APPLE): results of a lead-safe training program.

    Science.gov (United States)

    Ferguson, Alesia; Bursac, Zoran; Kern, David F

    2011-06-01

    Lead is still seen as one of the most harmful environmental toxins for young children, with the predominant source being deteriorating lead-based paint. Those at continued risk include those living in homes built before 1978, renovators and remodelers, and especially those with limited access to proper healthcare and diets. Proper training on lead-safe work practices focused on preventing and reducing the spread of lead dust can help reduce lead exposure. Presented in this paper are experiences in delivering lead-safe work practices training in six Arkansas cities, and results from pre- and post- surveys delivered before and immediately after the training. Pre- and post-surveys assess strong and weak areas of training. Participants demonstrated positive shifts in attitude and behavior towards lead-safe work practices following training. However, our research found that more emphasis should be focused on clarifying current lead exposure sources and routes for children.

  8. High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide.

    Science.gov (United States)

    Dastidar, Subham; Egger, David A; Tan, Liang Z; Cromer, Samuel B; Dillon, Andrew D; Liu, Shi; Kronik, Leeor; Rappe, Andrew M; Fafarman, Aaron T

    2016-06-08

    Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.

  9. Lead contamination and transfer in urban environmental compartments analyzed by lead levels and isotopic compositions

    International Nuclear Information System (INIS)

    Hu, Xin; Sun, Yuanyuan; Ding, Zhuhong; Zhang, Yun; Wu, Jichun; Lian, Hongzhen; Wang, Tijian

    2014-01-01

    Lead levels and isotopic compositions in atmospheric particles (TSP and PM 2.5 ), street dust and surface soil collected from Nanjing, a mega city in China, were analyzed to investigate the contamination and the transfer of lead in urban environmental compartments. The lead contents in TSP and PM 2.5 are significantly higher than them in the surface soil and street dust (p  206 Pb/ 207 Pb vs. 208 Pb/ 206 Pb and 206 Pb/ 207 Pb vs. 1/Pb imply that the street dust and atmospheric particles (TSP and PM 2.5 ) have very similar lead sources. Coal emissions and smelting activities may be the important lead sources for street dust and atmospheric particles (TSP and PM 2.5 ), while the deposition of airborne lead is an important lead source for urban surface soil. - Highlights: • Lead levels and isotope ratios in atmospheric particles, street dust and surface soil. • Significant enrichment of lead in atmospheric particles was observed. • Street dust and atmospheric particles have similar lead sources. • Endmembers of soil lead differ from street dust and atmospheric particles. • Airborne lead poses the main risks to unban environmental quality. - Transfer of airborne particle bound lead into street dust and surface soil in unban environmental based on lead levels and isotopic compositions

  10. Experience gained in gamma spectroscopy; Experience acquise dans la spectrometrie gamma

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmaire, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    There are two types of method which make it possible to estimate the internal contamination of individuals. On the one hand these are the indirect techniques based on measurements of the excreted products, on the other there are the direct techniques in which attempts are made to measure directly the radio-activity existing in the organism. We propose to give a few of the results obtained by the direct method using equipment built by the Commissariat a l'Energie Atomique. The apparatus consists of a {gamma} spectrometer. It includes: 1) A crystal of sodium iodide 20 cm in diameter and 10 cm high. The large size of this crystal ensures a good sensitivity and makes it possible to carry out rapid measurements. 2) A 25 channel type SAE 25 selector which classifies the pulses according to their amplitude. It is therefore possible to distinguish between {gamma} rays of varying energy. 3) A comparatively very light radiation protection, consisting of only 5 cm thickness of lead which diminishes the ambient {gamma} ray intensity to a sufficient level for the majority of the measurements. A certain collimation is thus obtained which makes it possible to localise the source approximately and to reduce the undesirable effects of external contamination. (author) [French] Deux types de methodes permettent d'apprecier la contamination interne d'un individu. D'une part, les techniques indirectes basees sur la mesure des produits excretes, d'autre part, les techniques directes au moyen desquelles on essaie de mesurer directement la radioactivite existant dans l'organisme. Nous nous proposons d'indiquer quelques resultats obtenus par la methode directe, au moyen d'ensembles realises par le Commissariat a l'Energie Atomique. L'appareillage est un spectrometre {gamma}. II comprend: 1) Un cristal d'iodure de sodium de 20 cm de diametre et 10 cm de hauteur. La grande taille de ce cristal assure une bonne sensibilite et permet d'effectuer des mesures rapides. 2) Un selecteur a 25 canaux

  11. Relationship between zinc protoporphyrin (ZPP) and free erythrocyte protoporphyrin (FEP) in lead-exposed individuals

    Energy Technology Data Exchange (ETDEWEB)

    Karacic, V.; Pripic-Majic, D.; Telis, S.

    1980-11-01

    The relationship between zinc protoporphyrin (ZPP) and total erythrozyte protoporphyrin, measured as free erythrozyte protoporphyrin (FEP), was determined in 194 adult subjects with different occupational and non-occupational lead exposures. Furthermore, the ZPP-FEP comparison was considered with respect to the dose-effect relationship of ZPP and FEP with blood lead (PbB) for males and females, Bilirubin (Bil.) interferences in ZPP analysis were taken into account. A very close and highly significant relationship was established between ZPP and FEP values. A significant correlation between log ZPP or log FEP and PbB was also found. It was established, by both in vitro and in vivo studies, that Bil. interferes with the ZPP fluorescence readings; the relationship between false positive ZPP concentrations and Bil. concentrations was highly significant. A small but highly significant influence of increased carboxyhemoglobin (COHb) concentrations on the decrease in hermatofluorometer ZPP readings, due to inadequate oxygenation of the blood, was found. The results obtained confirm the usefulness of ZPP determinations using hematofluorometers for surveillance of increased lead absorption but stress that the interfering effect of Bil. and to a lesser extent of COHb, cannot be ignored.

  12. 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

  13. Eryptosis in lead-exposed workers.

    Science.gov (United States)

    Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8μg/dl) and non-exposed workers (4.2μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Survey of mercury, cadmium and lead content of household batteries

    Energy Technology Data Exchange (ETDEWEB)

    Recknagel, Sebastian, E-mail: sebastian.recknagel@bam.de [BAM Federal Institute for Materials Research and Testing, Department of Analytical Chemistry, Reference Materials, Richard-Willstätter-Straße 11, D-12489 Berlin (Germany); Radant, Hendrik [BAM Federal Institute for Materials Research and Testing, Department of Analytical Chemistry, Reference Materials, Richard-Willstätter-Straße 11, D-12489 Berlin (Germany); Kohlmeyer, Regina [German Federal Environment Agency (UBA), Section III 1.6 Extended Producer Responsibility, Wörlitzer Platz 1, D-06844 Dessau-Roßlau (Germany)

    2014-01-15

    Highlights: • A well selected sample of 146 batteries was analysed for its heavy metals content. • A comparison was made between heavy metals contents in batteries in 2006 and 2011. • No significant change after implementation of the new EU Batteries Directive. • Severe differences in heavy metal contents were found in different battery-types. - Abstract: The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels.

  15. Survey of mercury, cadmium and lead content of household batteries

    International Nuclear Information System (INIS)

    Recknagel, Sebastian; Radant, Hendrik; Kohlmeyer, Regina

    2014-01-01

    Highlights: • A well selected sample of 146 batteries was analysed for its heavy metals content. • A comparison was made between heavy metals contents in batteries in 2006 and 2011. • No significant change after implementation of the new EU Batteries Directive. • Severe differences in heavy metal contents were found in different battery-types. - Abstract: The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels

  16. Characterization of the microstructure of tin-silver lead free solder

    Energy Technology Data Exchange (ETDEWEB)

    Hurtony, Tamás, E-mail: hurtony@ett.bme.hu [Department of Electronics Technology, Budapest University of Technology and Economics, Egry József utca 18, Budapest, H-1111 (Hungary); Szakál, Alex; Almásy, László [Neutron Spectroscopy Department, Wigner Research Centre for Physics, Budapest (Hungary); Len, Adél [Neutron Spectroscopy Department, Wigner Research Centre for Physics, Budapest (Hungary); Faculty of Engineering and Information Technology, University of Pécs (Hungary); Kugler, Sándor [Department of Theoretical Physics, Budapest University of Technology and Economics (Hungary); Bonyár, Attila; Gordon, Péter [Department of Electronics Technology, Budapest University of Technology and Economics, Egry József utca 18, Budapest, H-1111 (Hungary)

    2016-07-05

    Reliability and lifetime are the two most relevant design considerations in the production of safety critical assemblies. For example in a modern automobile dozens of electronic assemblies are integrated in which thousands of solder joints are mounting the electronic components to the printed circuit boards. There exists no standardised and universal observation method for characterising the fine microstructure of such solder joints. Previously we have developed a new method for the quantitative characterization of lead-free solder alloys and in present study the validity of the proposed method is demonstrated. Microstructure of Sn-3.5Ag lead free solder alloy was investigated by electrochemical impedance spectroscopy. Solder samples were solidified with different cooling rates in order to induce differences in the microstructure. Microstructure of the ingots was revealed by selective electrochemical etching. Electrochemical impedance spectra (EIS) were measured before and after the selective etching process. The complex impedance spectra contain information about microstructure of the solder alloys. Comparison and modelling of two EIS spectra allowed obtaining a characteristic parameter of surface structure of the etched specimens. The EIS measurements were complemented with small angle neutron scattering measurements and scanning electron microscopy, in order to correlate the EIS parameter with the magnitude of the interface of the β-Sn and Ag{sub 3}Sn phases.

  17. Efficacy of a tool to predict short-term mortality in older people presenting at emergency departments: Protocol for a multi-centre cohort study.

    Science.gov (United States)

    Cardona, Magnolia; Lewis, Ebony T; Turner, Robin M; Alkhouri, Hatem; Asha, Stephen; Mackenzie, John; Perkins, Margaret; Suri, Sam; Holdgate, Anna; Winoto, Luis; Chang, Chan-Wei; Gallego-Luxan, Blanca; McCarthy, Sally; Kristensen, Mette R; O'Sullivan, Michael; Skjøt-Arkil, Helene; Ekmann, Anette A; Nygaard, Hanne H; Jensen, Jonas J; Jensen, Rune O; Pedersen, Jonas L; Breen, Dorothy; Petersen, John A; Jensen, Birgitte N; Mogensen, Christian Backer; Hillman, Ken; Brabrand, Mikkel

    Prognostic uncertainty inhibits clinicians from initiating timely end-of-life discussions and advance care planning. This study evaluates the efficacy of the CriSTAL (Criteria for Screening and Triaging to Appropriate aLternative care) checklist in emergency departments. Prospective cohort study of patients aged ≥65 years with any diagnosis admitted via emergency departments in ten hospitals in Australia, Denmark and Ireland. Electronic and paper clinical records will be used to extract risk factors such as nursing home residency, physiological deterioration warranting a rapid response call, personal history of active chronic disease, history of hospitalisations or intensive care unit admission in the past year, evidence of proteinuria or ECG abnormalities, and evidence of frailty to be concurrently measured with Fried Score and Clinical Frailty Scale. Patients or their informal caregivers will be contacted by telephone around three months after initial assessment to ascertain survival, self-reported health, post-discharge frailty and health service utilisation since discharge. Logistic regression and bootstrapping techniques and AUROC curves will be used to test the predictive accuracy of CriSTAL for death within 90 days of admission and in-hospital death. The CriSTAL checklist is an objective and practical tool for use in emergency departments among older patients to determine individual probability of death in the short-term. Its validation in this cohort is expected to reduce clinicians' prognostic uncertainty on the time to patients' death and encourage timely end-of-life conversations to support clinical decisions with older frail patients and their families about their imminent or future care choices. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. High-precision lead isotope ratio measurement by inductively coupled plasma multiple collector mass spectrometry

    International Nuclear Information System (INIS)

    Walder, A.J.; Furuta, Naoki.

    1993-01-01

    An inductively coupled plasma (ICP) ion source coupled to a magnetic sector mass analyser equipped with seven Faraday detectors has been used to measure the lead isotope ratios in solutions of Sanshiro Pond sediment collected at the University of Tokyo, airborne particulates collected at Shinjuku in Tokyo and Merck multielement standard product number 97279494. A thallium correction technique was utilized to allow a simultaneous correction for mass bias. This work followed an earlier interlaboratory comparison study of the above-mentioned solutions using ICP quadrupole mass spectrometry, and has demonstrated a considerable improvement in analytical precision. The following isotope ratio measurements were recorded. Pond sediment solution containing 82 ng ml -1 lead: 206 Pb/ 204 Pb=17.762±0.014; 206 Pb/ 207 Pb=1.1424±0.0009; 208 Pb/ 204 Pb=37.678±0.034. Airborne particulate solution containing 45 ng ml -1 lead: 206 Pb/ 204 Pb=17.969±0.006; 206 Pb/ 207 Pb=1.1528±0.0003; 208 Pb/ 204 Pb=37.915±0.021. Merck multielement standard solution containing 100 ng ml -1 lead: 206 Pb/ 204 Pb=19.255±0.015; 206 Pb/ 207 Pb=1.2238±0.0004; 208 Pb/ 204 Pb=38.476±0.021 (All errors are given as ±2 standard deviations). (author)

  19. Lead concentration in blood of school children from copper mining area and the level of somatic development at birth

    Directory of Open Access Journals (Sweden)

    Teresa Sławińska-Ochla

    2011-12-01

    Full Text Available Background. The aim of the study was to assess the relations between lead intoxication in children at younger school age and the level of somatic development at birth. Materials and Methods. The research includes 717 children and adolescents 7–15 years old from LegnickoGłogowski copper mining region, which live in the vincity of „Głogów”, „Legnica” copper industrial plants and flotation tank reservoir „Żelazny most”. The analysis contained measures such as birth height, birth weight, Apgar score points, and blood lead level in 2007 and 2008. The whole blood lead level (Pb-B was indicated using atomic absorption spectrometry (AAS with electrothermic atomization by certified The Foundation for Children From The Copper Basin laboratory. Results.Rural childrenwere noted forsignificantly higher blood lead levelsthan urban peers. Also boysin comparison to girls had higher blood lead levels. Regardless of gender and place of residence there were no significant correlation between blood lead level and body mass at birth. Conclusion. The biological state of the organism at the moment of birth has no connection with the susceptibility to absorption of lead in the later phases of ontogenesis: the earlier school age and adlescence.

  20. A comparison of leading and lagging indicators of safety in naval aviation.

    Science.gov (United States)

    O'Connor, Paul; Cowan, Shawn; Alton, Jeffrey

    2010-07-01

    The purpose of this paper is to examine the results of two different methods of identifying human factors safety concerns in U.S. Naval aviation. In both studies, the information was collected using the Department of Defense Human Factors Analysis and Classification System (DoD-HFACS). In the first study, aviation mishap data (a lagging indictor) was obtained on 47 F/A-18 and 16 H-60 mishaps. In the second study, the responses of 68 squadrons to a survey regarding the human factors issues that they considered to be of the greatest safety concern were examined (a leading indicator). First study results revealed that skill-based errors were the most commonly cited factors for both F/A-18 and H-60 mishaps (70.2% and 81.3%, respectively). More specifically, the most commonly used nanocodes were 'over control/ under control' (27.7% and 56.3%, respectively), 'breakdown in visual scan' (27.7% and 12.5%, respectively), and 'procedural errors' (23.4% and 37.6%, respectively). The second study identified that the main concern of F/A-18 and H-60 aviators was workload and operational tempo (identified by 85% of squadrons). It can be concluded that the nanocodes that were most commonly used to classify the causes of past mishaps were not identified as major concerns by the squadrons who responded to the survey. The findings from these studies emphasize the importance of examining a number of performance metrics to ensure that effective measures are being taken to improve safety.

  1. Development and characterisation of disposable gold electrodes, and their use for lead(II) analysis

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Mohd F. M. [Cranfield University, Cranfield Health, Silsoe (United Kingdom); Institute for Medical Research, Toxicology and Pharmacology Unit, Herbal Medicine Research Centre, Kuala Lumpur (Malaysia); Tothill, Ibtisam E. [Cranfield University, Cranfield Health, Silsoe (United Kingdom)

    2006-12-15

    There is an increasing need to assess the harmful effects of heavy-metal-ion pollution on the environment. The ability to detect and measure toxic contaminants on site using simple, cost effective, and field-portable sensors is an important aspect of environmental protection and facilitating rapid decision making. A screen-printed gold sensor in a three-electrode configuration has been developed for analysis of lead(II) by square-wave stripping voltammetry (SWSV). The working electrode was fabricated with gold ink deposited by use of thick-film technology. Conditions affecting the lead stripping response were characterised and optimized. Experimental data indicated that chloride ions are important in lead deposition and subsequent analysis with this type of sensor. A linear concentration range of 10-50 {mu}g L{sup -1} and 25-300 {mu}g L{sup -1} with detection limits of 2 {mu}g L{sup -1} and 5.8 {mu}g L{sup -1} were obtained for lead(II) for measurement times of four and two minutes, respectively. The electrodes can be reused up to 20 times after cleaning with 0.5 mol L{sup -1} sulfuric acid. Interference of other metals with the response to lead were also examined to optimize the sensor response for analysis of environmental samples. The analytical utility of the sensor was demonstrated by applying the system to a variety of wastewater and soil sample extracts from polluted sites. The results are sufficient evidence of the feasibility of using these screen-printed gold electrodes for the determination of lead(II) in wastewater and soil extracts. For comparison purposes a mercury-film electrode and ICP-MS were used for validation. (orig.)

  2. 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

  3. Lead identification in soil surrounding a used lead acid battery smelter area in Banten, Indonesia

    International Nuclear Information System (INIS)

    Adventini, N; Santoso, M; Lestiani, D D; Syahfitri, W Y N; Rixson, L

    2017-01-01

    A used lead acid battery smelter generates particulates containing lead that can contaminate the surrounding environment area. Lead is a heavy metal which is harmful to health if it enters the human body through soil, air, or water. An identification of lead in soil samples surrounding formal and informal used lead acid battery smelters area in Banten, Indonesia using EDXRF has been carried out. The EDXRF accuracy and precision evaluated from marine sediment IAEA 457 gave a good agreement to the certified value. A number of 16 soil samples from formal and informal areas and 2 soil samples from control area were taken from surface and subsurface soils. The highest lead concentrations from both lead smelter were approximately 9 folds and 11 folds higher than the reference and control samples. The assessment of lead contamination in soils described in C f index was in category: moderately and strongly polluted by lead for formal and informal lead smelter. Daily lead intake of children in this study from all sites had exceeded the recommended dietary allowance. The HI values for adults and children living near both lead smelter areas were greater than the value of safety threshold 1. This study finding confirmed that there is a potential health risk for inhabitants surrounding the used lead acid battery smelter areas in Banten, Indonesia. (paper)

  4. HTS current lead units prepared by the TFA-MOD processed YBCO coated conductors

    International Nuclear Information System (INIS)

    Shiohara, K.; Sakai, S.; Ishii, Y.; Yamada, Y.; Tachikawa, K.; Koizumi, T.; Aoki, Y.; Hasegawa, T.; Tamura, H.; Mito, T.

    2010-01-01

    Two superconducting current lead units have been prepared using ten coated conductors of the Tri-Fluoro-Acetate - Metal Organic Deposition (TFA-MOD) processed Y 1 Ba 2 Cu 3 O 7-δ (YBCO) coated conductors with critical current (I c ) of about 170 A at 77 K in self-field. The coated conductors are 5 mm in width, 190 mm in length and about 120 μm in overall thickness. The 1.5 μm thick superconducting YBCO layer was synthesized through the TFA-MOD process on Hastelloy TM C-276 substrate tape with two buffer oxide layers of Gd 2 Zr 2 O 7 and CeO 2 . The five YBCO coated conductors are attached on a 1 mm thick Glass Fiber Reinforced Plastics (GFRP) board and soldered to Cu caps at the both ends. We prepared two 500 A-class current lead units. The DC transport current of 800 A was stably applied at 77 K without any voltage generation in all coated conductors. The voltage between both Cu caps linearly increased with increasing the applied current, and was about 350 μV at 500 A in both current lead units. According to the estimated values of the heat leakage from 77 K to 4.2 K, the heat leakage for the current lead unit was 46.5 mW. We successfully attained reduction of the heat leakage because of improvement of the transport current performance (I c ), a thinner Ag layer of YBCO coated conductor and usage of the GFRP board for reinforcement instead of a stainless steel board used in the previous study. The DC transport current of 1400 A was stably applied when the two current lead units were joined in parallel. The sum of the heat leakages from 77 K to 4.2 K for the combined the current lead units was 93 mW. In comparison with the conventional Cu current leads by gas-cooling, it could be noted that the heat leakage of the current lead is about one order of magnitude smaller than that of the Cu current lead.

  5. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  6. 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.

  7. 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.

  8. 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

  9. High Burden of Subclinical Lead Toxicity after Phase Out of Lead from Petroleum in Pakistan.

    Science.gov (United States)

    Majid, Hafsa; Khan, Aysha Habib; Khan, Nadeem Ullah; Siddiqui, Imran; Ghani, Farooq; Jafri, Lena

    2017-12-01

    To evaluate the frequency of subclinical lead toxicity. Cross-sectional study. Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from January 2011 to December 2014. Analysis of laboratory data for blood lead levels (BLL) was performed. Lead was tested by atomic absorption spectrometer. For all subjects, only initial test results were included while the results of repeated testing were excluded. Exemption was sought from institutional ethical review committee. BLL of 2-10 ug/dl and 10-70 ug/dl in children and adults, respectively were taken as subclinical lead toxicity. Amongst the total number of subjects tested (n=524), 26.5% (n=139) were children (lead level 16.9 ug/dl (36.1-4)] and lower level [4.2 ug/dl (6.8-2.6)] in children with lead levels while most had either subclinical (76%, n=106) or toxic lead levels (8%, n=11). In adults, (55%, n=212) subjects had desired lead levels, and 40% (n=154) and 4.99% (n=19) had subclinical and toxic lead levels. Presence of subclinical lead poisoning even after phasing out of lead petroleum in Pakistanis is alarming, especially in children. A national population-based study to determine the lead status and targeted intervention to identify potential sources is need of the time.

  10. Lead isotopes reveal different sources of lead in balsamic and other vinegars

    International Nuclear Information System (INIS)

    Ndung'u, Kuria; Hibdon, Sharon; Veron, Alain; Flegal, A. Russell

    2011-01-01

    Fifty-eight brands of balsamic vinegars were analyzed for lead concentrations and isotopic compositions ( 204 Pb, 206 Pb, 207 Pb, and 208 Pb) to test the findings of a previous study indicating relatively high levels of lead contamination in some of those vinegars - more than two thirds (70%) of them exceeded California's State Maximum Level (34 μg/L) based on consumption rates ≥ 0.5 μg Pb per day. The Lead isotopic fingerprints of all those vinegars with high lead concentrations were then found to be primarily anthropogenic. This isotopic analysis unquestionably reveals multiple contamination sources including atmospheric pollutant Pb and an unidentified contamination source, likely occurring after grape harvest. Organically grown grape vinegars display the same Pb content and isotopic signatures as other vinegars. This implies that pesticides might not be a significant source of pollutant Pb in vinegars. A significant post-harvest contamination would be inherited from chemicals added during production and/or material used during transport, processing or storage of these vinegars. This is consistent with the highest Pb levels being found in aged vinegars (112 ± 112 μg/L) in contrast to other vinegars (41.6 ± 28.9 μg/L) suggesting contamination during storage. It is, therefore, projected that lead levels in most vinegars, especially aged balsamic and wine vinegars, will decrease with improvements in their manufacture and storage processes consequential to recent concerns of elevated levels of lead in some vinegars. - Highlights: → First extensive study on content and possible sources of lead in balsamic vinegars. → Half of the vinegars exceed California's State Maximum Level for human consumption. → Lead content in vinegars seems to be mainly post-harvest from industrial processes.

  11. 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 ...

  12. Leading by example to protect the environment : Do the costs of leading matter?

    NARCIS (Netherlands)

    van der Heijden, E.C.M.; Moxnes, E.

    2013-01-01

    Environmentalists often urge their home countries to take a leading role in reducing global environmental problems like climate change. A pertinent question is, Will examples set by leading nations influence others to follow suit, and if so, do the costs of leading matter? For instance, will costly

  13. Leading by Example to Protect the Environment; Do the Costs of Leading Matter?

    NARCIS (Netherlands)

    van der Heijden, E.C.M.; Moxnes, E.

    2011-01-01

    Environmentalists often urge their home countries to take a leading role in reducing global environmental problems like climate change. A pertinent question is: will examples set by leading nations influence others to follow suit, and if so, do the costs of leading matter? For instance, will costly

  14. 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

  15. High-temperature superconducting current leads

    Science.gov (United States)

    Hull, J. R.

    1992-07-01

    The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

  16. Lead, arsenic, and copper content of crops grown on lead arsenate-treated and untreated soils

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, D

    1972-01-01

    Increased lead and arsenic concentrations in the surface soil (0-15 cm), resulting from applications of lead arsenate (PbHAs0/sub 1/), increased both lead and arsenic levels in crops grown on treated plots. The lead levels in some crops approached or exceeded the Canadian residue tolerance of 2.0 ppM. Lead arsenate soil treatments did not affect copper absorption by crops. On areas such as old orchard land contaminated with lead arsenate residues it may be advisable to ascertain crops, and also to determine the lead affinity and arsenic sensitivity of the plants to be grown.

  17. Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity.

    Science.gov (United States)

    McConnell, Joseph R; Wilson, Andrew I; Stohl, Andreas; Arienzo, Monica M; Chellman, Nathan J; Eckhardt, Sabine; Thompson, Elisabeth M; Pollard, A Mark; Steffensen, Jørgen Peder

    2018-05-29

    Lead pollution in Arctic ice reflects midlatitude emissions from ancient lead-silver mining and smelting. The few reported measurements have been extrapolated to infer the performance of ancient economies, including comparisons of economic productivity and growth during the Roman Republican and Imperial periods. These studies were based on sparse sampling and inaccurate dating, limiting understanding of trends and specific linkages. Here we show, using a precisely dated record of estimated lead emissions between 1100 BCE and 800 CE derived from subannually resolved measurements in Greenland ice and detailed atmospheric transport modeling, that annual European lead emissions closely varied with historical events, including imperial expansion, wars, and major plagues. Emissions rose coeval with Phoenician expansion, accelerated during expanded Carthaginian and Roman mining primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire. Emissions fluctuated synchronously with wars and political instability particularly during the Roman Republic, and plunged coincident with two major plagues in the second and third centuries, remaining low for >500 years. Bullion in silver coinage declined in parallel, reflecting the importance of lead-silver mining in ancient economies. Our results indicate sustained economic growth during the first two centuries of the Roman Empire, terminated by the second-century Antonine plague.

  18. Characterization of lead-free solders for electronic packaging

    Science.gov (United States)

    Ma, Hongtao

    The characterization of lead-free solders, especially after isothermal aging, is very important in order to accurately predict the reliability of solder joints. However, due to lack of experimental testing standards and the high homologous temperature of solder alloys (Th > 0.5T m even at room temperature), there are very large discrepancies in both the tensile and creep properties provided in current databases for both lead-free and Sn-Pb solder alloys. In this research, mechanical measurements of isothermal aging effects and the resulting changes in the materials behavior of lead-free solders were performed. A novel specimen preparation procedure was developed where the solder uniaxial test specimens are formed in high precision rectangular cross-section glass tubes using a vacuum suction process. Using specimens fabricated with the developed procedure, isothermal aging effects and viscoplastic material behavior evolution have been characterized for 95.5Sn-4.0Ag-0.5Cu (SAC405) and 96.5Sn-3.0Ag-0.5Cu (SAC305) lead-free solders, which are commonly used as the solder ball alloy in lead-free BGAs and other components. Analogous tests were performed with 63Sn-37Pb eutectic solder samples for comparison purposes. Up to 40% reduction in tensile strength was observed for water quenched specimens after two months of aging at room temperature. Creep deformation also increased dramatically with increasing aging durations. Microstructural changes during room temperature aging were also observed and recorded for the solder alloys and correlated with the observed mechanical behavior changes. Aging effects at elevated temperatures for up to 6 months were also investigated. Thermal aging caused significant tensile strength loss and deterioration of creep deformation. The thermal aging results also showed that after an initial tensile strength drop, the Sn-Pb eutectic solder reached a relatively stable stage after 200 hours of aging. However, for SAC alloy, both the tensile and

  19. 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

  20. 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.

  1. 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.

  2. Using Community-Based Participatory Research to Explore Backyard Gardening Practices and Soil Lead Concentrations in Urban Neighborhoods.

    Science.gov (United States)

    Johnson, Sheri; Cardona, Dalila; Davis, Jeremy; Gramling, Benjamin; Hamilton, Chelsea; Hoffmann, Ray; Ruis, Sabrina; Soldat, Doug; Ventura, Steve; Yan, Ke

    2016-01-01

    Lead exposure is a serious health threat for children. Soil is an important exposure pathway, primarily through ingestion and inhalation. Urban agriculture is increasing. Potential environmental health risks associated with residential gardening may not be well known to community residents. A community-based participatory research (CBPR) approach was implemented to explore the relationship between urban residential vegetable gardening and lead exposure in children. The primary objectives were to characterize local backyard vegetable gardening practices, measure residential and commercial soil lead concentrations and spatial distributions, and identify priorities for individual and collective action. Participants were recruited in two stages. In phase 1, adult gardeners participated in structured interviews. In phase 2, a multistage representative sampling approach was implemented to recruit adult gardeners for interviews and soil testing. Twenty adults participated in gardening practice interviews. Adults perceive many benefits from backyard gardening and initially expressed few concerns about lead exposure risk. Results indicate that children are actively involved in backyard gardening. Total soil lead concentrations from 17 residential properties ranged from 7 to 3,234 mg kg-1(median, 187; mean, 432). Commercial soils had lead concentrations that ranged from 6 to 13 mg kg(-1) (median, 6.5; mean, 7.6). Nonparametric Mann-Whitney comparisons indicated a significant difference in lead concentration between commercial soil and residential soil (p<0.0001). Advocacy for resources needed to eliminate dangerous levels of lead from the environment, especially in communities where divestment has occurred, is enhanced through CBPR. Increasing access to soil testing is an important action step.

  3. Activación del topacio natural irradiado por neutrones en el núcleo del reactor RP-10

    OpenAIRE

    Gómez, J.; Parreño, Fernando; Lázaro, Gerardo; Vela, Mariano

    2003-01-01

    Se obtuvieron cristales de topacio activados al ser irradiados con neutrones dentro del núcleo del reactor RP-10. La activación depende del flujo de neutrones, por ello se desarrolló portamuestras (canes de irradiación) para absorber que son los causantes de la activación

  4. A New System for Neuronavigation and Stereotactic Biopsy ...

    African Journals Online (AJOL)

    This hybrid system comprises three main parts: main frame, monitoring system, and pantograph, which are connected to each other and to the operating table by particular attachments. For using this system, after performing CT SCAN or Magnetic Resonance Imaging (MRI) the axial view will be transferred to Liquid Cristal ...

  5. Critical Studies in Teaching and Learning - Vol 2, No 2 (2014)

    African Journals Online (AJOL)

    Using Wikis to Teach History Education to 21st Century Learners: A Hermeneutic Perspective · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Dorothy Sebbowa, Dick Ng'ambi, Cheryl Brown, 24-48. http://dx.doi.org/10.14426/cristal.v3i1 ...

  6. Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Vernon G., E-mail: vthomas@uoguelph.ca [Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Scheuhammer, Anton M.; Bond, Della E. [Metals Toxicology Laboratory, National Wildlife Research Centre, Carleton University, Ottawa, Ontario, K1A 0H3 (Canada)

    2009-05-15

    Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb204, 206, 207, 208) by inductively coupled plasma mass spectrometry. At the Glendye (N = 111) and Invermark (N = 85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (> 20 mug/g dry weight). In bones of these highly exposed birds, a combination of Pb206:Pb207 and Pb208:Pb207ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead > 20 mug/g. The Pb206:Pb207 and Pb208:Pb207ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

  7. The effect of interior lead hazard controls on children's blood lead concentrations: a systematic evaluation.

    Science.gov (United States)

    Haynes, Erin; Lanphear, Bruce P; Tohn, Ellen; Farr, Nick; Rhoads, George G

    2002-01-01

    Dust control is often recommended to prevent children's exposure to residential lead hazards, but the effect of these controls on children's blood lead concentrations is uncertain. We conducted a systematic review of randomized, controlled trials of low-cost, lead hazard control interventions to determine the effect of lead hazard control on children's blood lead concentration. Four trials met the inclusion criteria. We examined mean blood lead concentration and elevated blood lead concentrations (> or = 10 microg/dL, > or = 15 microg/dL, and > or = 20 microg/dL) and found no significant differences in mean change in blood lead concentration for children by random group assignment (children assigned to the intervention group compared with those assigned to the control group). We found no significant difference between the intervention and control groups in the percentage of children with blood lead > or = 10 microg/dL, 29% versus 32% [odds ratio (OR), 0.85; 95% confidence interval (CI), 0.56-1.3], but there was a significant difference in the percentage of children with blood lead > or = 15 microg/dL between the intervention and control groups, 6% versus 14% (OR, 0.40; 95% CI, 0.21-0.80) and in the percentage of children with blood lead > or = 20 microg/dL between the intervention and control groups, 2% versus 6% (OR, 0.29; 95% CI, 0.10-0.85). We conclude that although low-cost, interior lead hazard control was associated with 50% or greater reduction in the proportion of children who had blood lead concentrations exceeding 15 microg/dL and > or = 20 microg/dL, there was no substantial effect on mean blood lead concentration.

  8. Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors

    International Nuclear Information System (INIS)

    Thomas, Vernon G.; Scheuhammer, Anton M.; Bond, Della E.

    2009-01-01

    Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb204, 206, 207, 208) by inductively coupled plasma mass spectrometry. At the Glendye (N = 111) and Invermark (N = 85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (> 20 mug/g dry weight). In bones of these highly exposed birds, a combination of Pb206:Pb207 and Pb208:Pb207ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead > 20 mug/g. The Pb206:Pb207 and Pb208:Pb207ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

  9. 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

  10. Americium-241 use of measurement lead equivalent thickness for medical x-ray room: A review

    International Nuclear Information System (INIS)

    Mohd Khalid Matori; Husaini Saleh; Abd Aziz Mhd Ramli; Muhammad Jamal Md Isa; Mohd Firdaus Abd Rahman; Zainal Jamaluddin

    2010-01-01

    Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for X-ray room at health centres. Results of measurement of 30 irradiation rooms conducted from 2009 to mid 2010 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that 96.7 % of the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

  11. Lead contamination and transfer in urban environmental compartments analyzed by lead levels and isotopic compositions.

    Science.gov (United States)

    Hu, Xin; Sun, Yuanyuan; Ding, Zhuhong; Zhang, Yun; Wu, Jichun; Lian, Hongzhen; Wang, Tijian

    2014-04-01

    Lead levels and isotopic compositions in atmospheric particles (TSP and PM2.5), street dust and surface soil collected from Nanjing, a mega city in China, were analyzed to investigate the contamination and the transfer of lead in urban environmental compartments. The lead contents in TSP and PM2.5 are significantly higher than them in the surface soil and street dust (p lead to the major crustal elements (Al, Sr, Ti and Fe) indicates significant lead enrichment in atmospheric particles. The plots of (206)Pb/(207)Pb vs.(208)Pb/(206)Pb and (206)Pb/(207)Pb vs. 1/Pb imply that the street dust and atmospheric particles (TSP and PM2.5) have very similar lead sources. Coal emissions and smelting activities may be the important lead sources for street dust and atmospheric particles (TSP and PM2.5), while the deposition of airborne lead is an important lead source for urban surface soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Lead isotope profiling in dairy calves.

    Science.gov (United States)

    Buchweitz, John; McClure-Brinton, Kimberly; Zyskowski, Justin; Stensen, Lauren; Lehner, Andreas

    2015-03-01

    Lead (Pb) is a common cause of heavy metal poisonings in cattle. Sources of Pb on farms include crankcase oil, machinery grease, batteries, plumbing, and paint chips. Consequently, consumption of Pb from these sources may negatively impact animal health and Pb may be inadvertently introduced into the food supply. Therefore, the scope of poisoning incidents must be clearly assessed and sources of intoxication identified and strategies to mitigate exposure evaluated and implemented to prevent future exposures. Stable isotope analysis by inductively-coupled plasma mass spectrometry (ICP-MS) has proven itself of value in forensic investigations. We report on the extension of Pb stable isotope analysis to bovine tissues and profile comparisons with paint chips and soils collected from an affected dairy farm to elucidate the primary source. Pb occurs naturally as four stable isotopes: (204)Pb, (206)Pb, (207)Pb, and (208)Pb. Herein a case is reported to illustrate the use of (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios to link environmental sources of exposure with tissues from a poisoned animal. Chemical Pb profiling provides a valuable tool for field investigative approaches to Pb poisoning in production agriculture and is applicable to subclinical exposures. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. 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

  14. States with a great number of quasi-particles in even lead isotopes

    International Nuclear Information System (INIS)

    Auger, G.; Manfredi, V.R.

    1975-01-01

    The even lead isotopes have been studied by means of a spectral distribution calculation in the sub-spaces defined by their number of quasi-particles. The comparison with results obtained in the thin isotopes shows that the overlap of the various sub-spaces is strongly dependent on the residual interaction used; namely, states with a great number of quasi-particles do exist in the low energy part of the spectra. The problem of spurious states implied by this method, states responsible for an over-estimation of the sub-space coupling, is treated and various corrections are proposed for the dimensions as well as for the centroids and widths of the sub-spaces [fr

  15. Comparison of nevirapine plasma concentrations between lead-in and steady-state periods in Chinese HIV-infected patients.

    Directory of Open Access Journals (Sweden)

    Huijuan Kou

    Full Text Available To investigate the potential of nevirapine 200 mg once-daily regimen and evaluate the influence of patient characteristics on nevirapine concentrations.This was a prospective, multicentre cohort study with 532 HIV-infected patients receiving nevirapine as a part of their initial antiretroviral therapy. Plasma samples were collected at trough or peak time at the end of week 2 (lead-in period and week 4, 12, 24, 36, and 48 (steady-state period, and nevirapine concentrations were determined using a validated HPLC method. Potential influencing factors associated with nevirapine concentrations were evaluated using univariate and multivariate logistic regression.A total of 2348 nevirapine plasma concentrations were collected, including 1510 trough and 838 peak values. The median nevirapine trough and peak concentration during the lead-in period were 4.26 µg/mL (IQR 3.05-5.61 and 5.07 µg/mL (IQR 3.92-6.44 respectively, which both exceeded the recommended thresholds of nevirapine plasma concentrations. Baseline hepatic function had a moderate effect on median nevirapine trough concentrations at week 2 (4.25 µg/mL v.s. 4.86 µg/mL, for ALT <1.5 × ULN and ≥ 1.5 × ULN, respectively, P = 0.045. No significant difference was observed in median nevirapine trough concentration between lead-in and steady-state periods in patients with baseline ALT and AST level ≥ 1.5 × ULN (P = 0.171, P = 0.769, which was different from the patients with ALT/AST level <1.5ULN. The median trough concentrations were significantly higher in HIV/HCV co-infected patients than those without HCV at week 48 (8.16 µg/mL v.s. 6.15 µg/mL, P = 0.004.The 200 mg once-daily regimen of nevirapine might be comparable to twice-daily in plasma pharmacokinetics in Chinese population. Hepatic function prior to nevirapine treatment and HIV/HCV coinfection were significantly associated with nevirapine concentrations.

  16. 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.

  17. A Note on Rocket Performance Comparison Through Impulse and Thrust Coefficients

    Science.gov (United States)

    Taylor, N. V.

    Comparison of rocket motor systems is important when generating data to be used in making design decisions. In order to present meaningful comparisons, non-dimensional numbers related to performance are beneficial, as they remove effects of scale. Traditionally thrust coefficients and C* have been used to quantify the aerodynamic and chemical performance of a system respectively. However, it is argued here that in fact the thrust coefficient does not fully account for aerodynamic performance, as the impact of non-uniform flow at the throat is not accounted for. This discharge coefficient is usually allocated to the chemical efficiency through a correction to C*. However, this causes a coupling between chemical and aerodynamic efficiencies which may lead to poor design decisions. Through the use of a specific impulse coefficient, this risk is avoided, and furthermore comparison of unconventional nozzles becomes more straightforward. It is admitted, however, that this has no actual impact on real motor performance, being more in the way of a tidier `accounting' system.

  18. Lead accumulation in the straw mushroom, Volvariella volvacea, from lead contaminated rice straw and stubble.

    Science.gov (United States)

    Kumhomkul, Thapakorn; Panich-pat, Thanawan

    2013-08-01

    Straw mushrooms were grown on lead contaminated rice straw and stubble. Study materials were dried, acid digested, and analyzed for lead using flame atomic absorption spectrophotometry. The results showed the highest lead concentration in substrate was 445.350 mg kg⁻¹ in Treatment 3 (T3) and the lowest was BD (below detection) in Treatment 1 (T1). The maximum lead content in straw mushrooms was 5.072 mg kg⁻¹ dw in pileus of T3 and the minimum lead content in straw mushrooms was BD in egg and mature (stalk and pileus) stage of T1. The lead concentration in straw mushrooms was affected by the age of the mycelium and the morphology of mushrooms. Mushrooms' lead uptake produced the highest accumulation in the cell wall. Some lead concentrations in straw mushrooms exceeded the EU standard (>3 mg kg⁻¹ dw).

  19. Power reactors and sub-critical blanket systems with lead and lead-bismuth as coolant and/or target material. Utilization and transmutation of actinides and long lived fission products

    International Nuclear Information System (INIS)

    2003-05-01

    High level radioactive waste disposal is an issue of great importance in the discussion of the sustainability of nuclear power generation. The main contributors to the high radioactivity are the fission products and the minor actinides. The long lived fission products and minor actinides set severe demands on the arrangements for safe waste disposal. Fast reactors and accelerator driven systems (ADS) are under development in Member States to reduce the long term hazard of spent fuel and radioactive waste, taking advantage of their incineration and transmutation capability. Important R and D programmes are being undertaken in many Member States to substantiate this option and advance the basic knowledge in this innovative area of nuclear energy development. The conceptual design of the lead cooled fast reactor concept BREST-OD-300, as well as various other conceptual designs of lead/lead-bismuth cooled fast reactors have been developed to meet enhanced safety and non-proliferation requirements, aiming at both energy production and transmutation of nuclear waste. Some R and D studies indicate that the use of lead and lead-bismuth coolant has some advantages in comparison with existing sodium cooled fast reactor systems, e.g.: simplified design of fast reactor core and BOP, enhanced inherent safety, and easier radwaste management in related fuel cycles. Moreover, various ADS conceptual designs with lead and lead-bismuth as target material and coolant also have been pursued. The results to date are encouraging, indicating that the ADS has the potential to offer an option for meeting the challenges of the back end fuel cycle. During the last decade, there have been substantial advances in several countries with their own R and D programme in the fields of lead/lead-bismuth cooled critical and sub-critical concepts. coolant technology, and experimental validation. In this context, international exchange of information and experience, as well as international

  20. 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.

  1. Children’s Blood Lead Seasonality in Flint, Michigan (USA), and Soil-Sourced Lead Hazard Risks

    Science.gov (United States)

    Laidlaw, Mark A.S.; Filippelli, Gabriel M.; Sadler, Richard C.; Gonzales, Christopher R.; Ball, Andrew S.; Mielke, Howard W.

    2016-01-01

    In Flint; MI; USA; a public health crisis resulted from the switching of the water supply from Lake Huron to a more corrosive source from the Flint River in April 2014; which caused lead to leach from water lines. Between 2010 and 2015; Flint area children’s average blood lead patterns display consistent peaks in the third quarter of the year. The third quarter blood lead peaks displayed a declining trend between 2010 and 2013; then rose abruptly between the third quarters of 2013 from 3.6% blood lead levels ≥5 µg/dL to a peak of about 7% in the third quarter of 2014; an increase of approximately 50%. The percentage of blood lead level ≥5 µg/dL in the first quarter of 2015 then dropped to 2.3%; which was the same percentage as the first quarter of 2014 (prior to the Flint River water source change). The Flint quarterly blood lead level peak then rose to about 6% blood lead levels ≥ 5 µg/dL in the third quarter of 2015; and then declined to about 2.5% in the fourth quarter of 2015. Soil lead data collected by Edible Flint food collaborative reveal generally higher soil lead values in the metropolitan center for Flint; with lower values in the outskirts of the city. The questions that are not being asked is why did children’s blood lead levels display a seasonal blood lead pattern before the introduction of the new water supply in Flint; and what are the implications of these seasonal blood lead patterns? Based upon previous findings in Detroit and other North American cities we infer that resuspension to the air of lead in the form of dust from lead contaminated soils in Flint appears to be a persistent contribution to lead exposure of Flint children even before the change in the water supply from Lake Huron to the Flint River. PMID:27023578

  2. A measurement of the ratio of production cross sections for W + 1 jet to W + 0 jets and comparisons to QCD

    International Nuclear Information System (INIS)

    Abbott, B.

    1997-11-01

    A preliminary measurement of the ratio, R 10 , of the production cross sections for W + 1 Jet and W + 0 Jets processes at √s = 1800 GeV by the D0 Collaboration is presented. A comparison of this ratio is made to next-to-leading order calculations and the implications of these comparisons are discussed

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. Theory of the Influence of Phonon-Phonon and Electron-Phonon Interactions on the Scattering of Neutrons by Crystals; Theorie de l'influence des interactions phonon-phonon et electron-phonon sur la diffusion des neutrons par des cristaux; Teoriya vliyaniya vzaimodejstvij fonon-fonon iehlvktron-fonon na rasseyanie nejtronov kristalla-; Teoria de la influencia de las interacciones fonon-fonon y electron-fonon en la dispersion de neutrones por cristales

    Energy Technology Data Exchange (ETDEWEB)

    Kokkedee, J J.J. [Institute for Theoretical Physics of the University of Utrecht (Netherlands)

    1963-01-15

    interatomic or interionic distance in the crystal). Approximate calculations are performed to give some insight into the orders of magnitude of the effects under study. (author) [French] Comme le predit la theorie harmonique, le spectre de la diffusion inelastique coherente de neutrons par un monocristal non conducteur, pour un angle de diffusion donne, se compose d'une serie de pics de fonction delta, qui se superposent a un bruit de fond continu. Les pics correspondent a des phenomenes a un phonon, dans lesquels un phonon est absorbe ou emis par le neutron; le bruit de fond provient de phenomenes a plusieurs phonons. Lorsqu'il existe des forces anharmoniques (interaction phonon-phonon) les pics de fonction delta s'elargissent pour former des pics finis et leur frequence centrale est dephasee par rapport aux valeurs harmoniques. Dans le cas d'un metal il y a, en plus des interactions phonon-phonon, une interaction entre les phonons et les electrons de conduction, laquelle contribue a dephaser et elargir encore davantage les pics a un phonon. Continuant les travaux de Van Hove (qui avait considere le cas relativement simple d'un cristal non conducteur a l'etat fondamental, soit T = 0{sup o}K) l'auteut a etudie les deplacements et les largeurs des pics de diffusion resultant des interactions indiquees plus haut, a l'aide de la theorie de la perturbation a plusieurs particules, en ayant largement recours a la methode des diagrammes. Il admet, avant tout examen du probleme, que quelle que soit la force des interactions, la largeur de chaque pic est petite par rapport a la valeur de la frequence en son centres dans ces conditions seulement, on peut considerer que les pics sont bien definis par rapport au bruit de fond, si les calculs d'interaction sont pousses jusqu'aux ordres superieurs. On estime que cette hipothbse est realisee tant que les temperatures ne sont pas trop elevees et que les valeurs du vecteur d'onde des phonons ne sont pas trop considerables. La methode

  9. 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)

  10. 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

  11. Liquid metal reactor/Pressurized water reactor plant comparison study

    International Nuclear Information System (INIS)

    Halverson, T.G.

    1986-01-01

    The selection between alternative electric power generating technologies is mainly based on their overall economics. Capital costs account for over 60% of the total busbar cost of nuclear plants. Estimates reported in the literature have shown capital cost ratios of LMRs to PWRs ranging from less than 1 to as high as 1.8. To reduce this range of uncertainty, the study selected a method for cataloging plant hardware and then performed comparisons using engineering judgment as to the anticipated and reasonable cost differences. The paper summarizes the resulting one-on-one comparisons of components, systems, and buildings and identifies the LMR-PWR similarities and differences which influence costs. The study leads to the conclusion that the capital cost of the most up-to-date large LMR design would be very close to that of the latest PWRs

  12. Diagnostic value of ST-segment deviations during cardiac exercise stress testing: Systematic comparison of different ECG leads and time-points.

    Science.gov (United States)

    Puelacher, Christian; Wagener, Max; Abächerli, Roger; Honegger, Ursina; Lhasam, Nundsin; Schaerli, Nicolas; Prêtre, Gil; Strebel, Ivo; Twerenbold, Raphael; Boeddinghaus, Jasper; Nestelberger, Thomas; Rubini Giménez, Maria; Hillinger, Petra; Wildi, Karin; Sabti, Zaid; Badertscher, Patrick; Cupa, Janosch; Kozhuharov, Nikola; du Fay de Lavallaz, Jeanne; Freese, Michael; Roux, Isabelle; Lohrmann, Jens; Leber, Remo; Osswald, Stefan; Wild, Damian; Zellweger, Michael J; Mueller, Christian; Reichlin, Tobias

    2017-07-01

    Exercise ECG stress testing is the most widely available method for evaluation of patients with suspected myocardial ischemia. Its major limitation is the relatively poor accuracy of ST-segment changes regarding ischemia detection. Little is known about the optimal method to assess ST-deviations. A total of 1558 consecutive patients undergoing bicycle exercise stress myocardial perfusion imaging (MPI) were enrolled. Presence of inducible myocardial ischemia was adjudicated using MPI results. The diagnostic value of ST-deviations for detection of exercise-induced myocardial ischemia was systematically analyzed 1) for each individual lead, 2) at three different intervals after the J-point (J+40ms, J+60ms, J+80ms), and 3) at different time points during the test (baseline, maximal workload, 2min into recovery). Exercise-induced ischemia was detected in 481 (31%) patients. The diagnostic accuracy of ST-deviations was highest at +80ms after the J-point, and at 2min into recovery. At this point, ST-amplitude showed an AUC of 0.63 (95% CI 0.59-0.66) for the best-performing lead I. The combination of ST-amplitude and ST-slope in lead I did not increase the AUC. Lead I reached a sensitivity of 37% and a specificity of 83%, with similar sensitivity to manual ECG analysis (34%, p=0.31) but lower specificity (90%, pST-deviations is highest when evaluated at +80ms after the J-point, and at 2min into recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Consumption of lead-shot cervid meat and blood lead concentrations in a group of adult Norwegians.

    Science.gov (United States)

    Meltzer, H M; Dahl, H; Brantsæter, A L; Birgisdottir, B E; Knutsen, H K; Bernhoft, A; Oftedal, B; Lande, U S; Alexander, J; Haugen, M; Ydersbond, T A

    2013-11-01

    Several recent investigations have reported high concentrations of lead in samples of minced cervid meat. This paper describes findings from a Norwegian study performed in 2012 among 147 adults with a wide range of cervid game consumption. The main aim was to assess whether high consumption of lead-shot cervid meat is associated with increased concentration of lead in blood. A second aim was to investigate to what extent factors apart from game consumption explain observed variability in blood lead levels. Median (5 and 95 percentile) blood concentration of lead was 16.6 µg/L (7.5 and 39 µg/L). An optimal multivariate linear regression model for log-transformed blood lead indicated that cervid game meat consumption once a month or more was associated with approximately 31% increase in blood lead concentrations. The increase seemed to be mostly associated with consumption of minced cervid meat, particularly purchased minced meat. However, many participants with high and long-lasting game meat intake had low blood lead concentrations. Cervid meat together with number of bullet shots per year, years with game consumption, self-assembly of bullets, wine consumption and smoking jointly accounted for approximately 25% of the variation in blood lead concentrations, while age and sex accounted for 27% of the variance. Blood lead concentrations increased approximately 18% per decade of age, and men had on average 30% higher blood lead concentrations than women. Hunters who assembled their own ammunition had 52% higher blood lead concentrations than persons not making ammunition. In conjunction with minced cervid meat, wine intake was significantly associated with increased blood lead. Our results indicate that hunting practices such as use of lead-based ammunition, self-assembling of lead containing bullets and inclusion of lead-contaminated meat for mincing to a large extent determine the exposure to lead from cervid game consumption. © 2013 Elsevier Inc. All rights

  14. Occupational exposure to lead--granulometric distribution of airborne lead in relation to risk assessment.

    Science.gov (United States)

    Carelli, G; Masci, O; Altieri, A; Castellino, N

    1999-07-01

    The amount of airborne lead absorbed by the body during occupational exposure depends not only on lead concentration in workplace air, but also on the granulometric distribution of the aerosol. The Occupational Safety and Health Administration (OSHA) set the lead Permissible Exposure Limit (PEL) at 50 micrograms/m3 on the basis of Bernard's model and a number of assumptions, including assumption "C", which predicts that the first 12.5 micrograms/m3 are made up of fine particles (aerodynamic diameter 1 micron. Occupational exposure to airborne lead at a concentration of 50 micrograms/m3 and a granulometric distribution calculated according to the above mentioned assumption, leads, in the model, to a mean blood level of 40 micrograms/dl. In the present study, we tested the validity of assumption "C" in the environmental air of a factory that manufactured crystal glassware containing 24% lead oxide. An 8-stage impactor was used to measure the particle size of airborne dust collected from personal and area samplings. Results indicate that, on the whole, assumption "C" cannot be considered valid in the work environment investigated in this study. As a result, lead absorption levels in exposed workers may be noticeably different from those predicted by the OSHA model. We therefore suggest that in order to make a correct evaluation of the risk of occupational exposure to lead, it is essential to integrate total airborne lead concentration with a measurement of the granulometric distribution of the aerosol.

  15. Lead-210, polonium-210, and stable lead in the food-chain lichen, reindeer and man

    International Nuclear Information System (INIS)

    Persson, B.R.

    1972-01-01

    The measurements of stable lead and the natural fallout radionuclides lead-210 and polonium-210 in communities of lichen (Cladonia alpestris) in central Sweden from 1961 to 1970 indicate a quite constant level. The average lead-210 content per unit area in lichen carpets was found to be 15 +- 2 nCi m -2 , the average lead-210 activity concentration 6.7 +- 0.9 nCi per kg dry weight and the lead-210 specific activity 630 +- 60 nCi per g of stable lead. The polonium-210/lead-210 activity ratio was about 0.9 +- 0.1. The vertical distribution of lead-210 in the lichen carpet showed a maximum concentration in the top layer. The distribution was similar during 1967 and 1968 but the low amount of precipitation during 1968 and 1969 disturbed the distribution pattern in 1969 and 1970. The transfer of lead-210, polonium-210 and stable lead through the food chain: lichen, reindeer, and man was characterized. The absorbed dose rate in Lapps due to polonium-210 was estimated to be about 6 to 8 mrad per year in gonads and 8 to 20 mrad per year in bone tissues. This is about ten percent of their entire absorbed dose contribution from all natural radiation sources. (U.S.)

  16. Fracture mechanisms in lead zirconate titanate ceramics

    International Nuclear Information System (INIS)

    Freiman, S.W.; Chuck, L.; Mecholsky, J.J.; Shelleman, D.L.

    1986-01-01

    Lead Zirconate Titanate (PZT) ceramics can be formed over a wide range of PbTiO 3 /PbZrO 3 ratios and exist in a number of crystal structures. This study involved the use of various fracture mechanics techniques to determine critical fracture toughness, K /SUB IC/ , as a function of composition, microstructure, temperature, and electrical and thermal history. The results of these experiments indicate that variations in K /SUB IC/ are related to phase transformations in the material as well as to other toughening mechanisms such as twinning and microcracking. In addition, the strength and fracture toughness of selected PZT ceramics were determined using specimens in which a crack was introduced by a Vicker's hardness indentor. The variation of K /SUB IC/ with composition and microstructure was related to the extent of twin-crack interaction. Comparison of the plot of strength as a function of indentation load with that predicted from indentation fracture models indicates the presence of internal stresses which contribute to failure. The magnitude of these internal stresses has been correlated with electrical properties of the ceramic. Fractographic analysis was used to determine the magnitude of internal stresses in specimens failing from ''natural flaws.''

  17. The utility of Pinus sylvestris L. in dendrochemical investigations: Pollution impact of lead mining and smelting in Darley Dale, Derbyshire, UK

    International Nuclear Information System (INIS)

    Lageard, J.G.A.; Howell, J.A.; Rothwell, J.J.; Drew, I.B.

    2008-01-01

    This research investigates atmospheric pollution from an isolated and increasingly productive lead-smelting site by examining the dendrochemistry of Pinus sylvestris growing in the local environment and at control sites. Tree increment cores and soil in the rooting environment were analysed for lead content. Inter-site comparisons of lead-in-soil suggest that contamination of the soil may be a less important pathway for lead inclusion within wood than pathways via bark or needles. Levels of lead-in-wood (up to 38 mg kg -1 ) are at the upper end of those previously reported. There is evidence of radial translocation of lead towards the heartwood and variability in intra-site dendrochemical records. Mean site lead-in-wood records can however be related to a well-documented pollution chronology and also suggest the importance of local topography in the dispersal and deposition of particulate lead. This study demonstrates that P. sylvestris can be used to estimate the scale and timing of past pollution episodes in similar environmental contexts to those investigated at Darley Dale, where precisely dated pollution chronologies are lacking. - Mean site dendrochemical records for Pinus sylvestris can be used to estimate the general scale and timing of atmospheric pollution episodes

  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. The relationship between environmental lead and blood lead in children : a study in environmental epidemiology

    NARCIS (Netherlands)

    Brunekreef, B.

    1985-01-01

    This study deals with the relationship between environmental lead and blood lead in children.
    Chapter 1 provides a summary of the environmental health aspects of lead. The occurrence of lead in the environment and in man is described; children are discussed as a population at

  20. 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.