17 research outputs found

    Electron excitation of Ca XVII

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    Asbestos in the urban environment A manual of control

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    SIGLEAvailable from British Library Lending Division - LD:85/03989(Asbestos) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Theoretical line ratios for high temperature and high density Ne VII plasmas

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    SIGLELD:8053.4155(RL--83-034) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Flares on dMe stars IUE and optical observations of AT Mic, and comparison of far-ultraviolet stellar and solar flares

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    SIGLEAvailable from British Library Document Supply Centre- DSC:8053.4153(RAL--86-009) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Flare activity on UV Ceti Visible and IUE observations

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    SIGLEAvailable from British Library Document Supply Centre- DSC:8053.4153(RAL--88-053) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Dynamics of lead bioavailability and speciation in indoor dust and x-ray spectroscopic investigation of the link between ingestion and inhalation pathways

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    Lead (Pb) exposure from household dust is a major childhood health concern because of its adverse impact on cognitive development. This study investigated the absorption kinetics of Pb from indoor dust following a single dose instillation into C57BL/6 mice. Blood Pb concentration (PbB) was assessed over 24 h, and the dynamics of particles in the lung and gastro-intestinal (GI) tract were visualized using X-ray fluorescence (XRF) microscopy. The influence of mineralogy on Pb absorption and particle retention was investigated using X-ray absorption near-edge structure spectroscopy. A rapid rise in PbB was observed between 0.25 and 4 h after instillation, peaking at 8 h and slowly declining during a period of 24 h. Following clearance from the lungs, Pb particles were detected in the stomach and small intestine at 4 and 8 h, respectively. Analysis of Pb mineralogy in the residual particles in tissues at 8 h showed that mineral-sorbed Pb and Pb-phosphates dominated the lung, while organic-bound Pb and galena were the main phases in the small intestines. This is the first study to visualize Pb dynamics in the lung and GI tract using XRF microscopy and link the inhalation and ingestion pathways for metal exposure assessment from dust.Farzana Kastury, Euan Smith, Enzo Lombi, Martin W. Donnelley, Patricia L. Cmielewski, David W. Parsons, Matt Noerpel, Kirk G. Scheckel, Andrew M. Kingston, Glenn R. Myers, David Paterson, Martin D. de Jonge, and Albert L. Juhas

    Componentes do balanço de água no solo com cana-de-açúcar, com e sem adubação nitrogenada Water balance components in soils cropped to sugarcane, with and without nitrogen fertilization

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    O estudo do balanço de água no solo com cana-de-açúcar, cultivada em larga escala no Brasil, é essencial para o manejo agrícola, visando ao aumento de produtividade e à redução de riscos de poluição. Este estudo objetivou avaliar os componentes da equação do balanço de água em dois Latossolos cultivados com cana-de-açúcar (cana-planta), localizados nos Municípios de Jaboticabal e Pirassununga (São Paulo). Na área experimental de Jaboticabal, o estudo foi realizado entre os dias 30 de setembro de 2005 e 12 de julho de 2006, e constou de dois tratamentos: T1 (sem adubação nitrogenada) e T2 (120 kg ha-1 de N). Em Pirassununga, o estudo foi feito entre os dias 28 de setembro de 2005 e 08 de junho de 2006, mas apenas o tratamento T2. O delineamento experimental foi o de blocos aleatórios, com quatro repetições. O volume de controle utilizado para o balanço de água teve como limite superior a superfície do solo e como limite inferior outra paralela à primeira, localizada em profundidade de 0,90 m. As variações de armazenagem, as entradas (precipitação pluvial e ascensão capilar) e as saídas de água (evapotranspiração real e drenagem interna) nesse volume de solo, nas áreas experimentais de Jaboticabal e Pirassununga, foram determinadas em 13 e 10 períodos, respectivamente. Ambas as áreas estudadas eram planas e não irrigadas. Na área de Jaboticabal, em todo o período, tanto a perda de água por drenagem interna quanto o ganho por ascensão capilar foram maiores no tratamento T2 (-191,69 mm/5,33 mm e -238,37 mm/24,60 mm para T1 e T2, respectivamente); não houve diferença significativa de produtividade (145 e 146 t ha-1 para T1 e T2, respectivamente), nem de evapotranspiração real (1.058 mm para T1 e 1.028 mm para o T2) entre os tratamentos nesse ciclo de cana-planta, fazendo com que as plantas não adubadas apresentassem a mesma eficiência do uso da água (14 kg m-3) que as adubadas. Na área de Pirassununga, a drenagem interna e a ascensão capilar foram de -110,9 e 0,67 mm, respectivamente, e a eficiência de uso da água 13 kg m-3. Portanto, pode-se concluir que (a) nos períodos de alta pluviosidade, a drenagem interna foi significativa, alertando para possíveis problemas no manejo em relação a uma potencial de contaminação do lençol freático, e (b) tanto a evapotranspiração real quanto à eficiência do uso da água foram da mesma ordem de grandeza, independentemente da adubação nitrogenada, e a armazenagem de água no solo foi praticamente a mesma no início e no fim do ciclo estudado.<br>The water balance study in soils with sugarcane, cropped in large areas in Brazil, is essential for the agricultural management to increase the crop productivity and to reduce pollution risks. The objective of this research was to evaluate soil water balance equation components of two Oxisols under sugar-cane (first crop), in the counties of Jaboticabal and Pirassununga, State of São Paulo, Brazil. The study was carried out in an experimental area in Pirassununga (21 º 55 ' 54 '' S, 47 º 10 ' 54 '' W, 650 m), for only one level (120 kg ha-1) of nitrogen, in four replications. In Jaboticabal (21 º 19 ' 98 '' S, 48 º 19 ' 03 '' W, 600 m), two nitrogen levels were used: 0 kg ha-1 (treatment 1-T1) and 120 kg ha-1 (treatment 2-T2). In Pirassununga, the experiments were evaluated between September 28, 2005 and June 08, 2006 and, in Jaboticabal, between September 30, 2005 and July 12, 2006. The upper limit of the control volume used for the water balance was the soil surface and the lower limit a surface at a soil depth of 0.90 m, parallel to the soil surface. Soil water storage variations, soil water inputs (rain and capillary rise) and soil water outputs (internal drainage and actual evapotranspiration) were determined in 13 and 10 monitoring periods, in Jaboticabal and Pirassununga, respectively. Both studied areas were plane and non irrigated. In the area in Jaboticabal, both internal drainage and capillary rise were greater in treatment T2 (-191.69 mm/5.33 mm and -238.37 mm/24.60 mm for T1 and T2, respectively) for the entire period; there was no significant difference in yield (145 and 146 t ha-1 for T1 and T2, respectively) and also in actual evapotranspiration (1058 mm for T1 and 1028 mm for T2) between the treatments in this sugar-cane cycle, so that the water use efficiency of plants without nitrogen fertilization was the same (14 kg m-3) as of those with nitrogen fertilization. In Pirassununga, internal drainage and capillary rise were -110.9 and 0.67 mm, respectively and the water use efficiency 13 kg m-3. It can therefore be concluded that (a) internal drainage was relevant in the high rainfall periods, which warns for possible problems in soil management due to the risk of groundwater contamination, and (b) the actual evapotranspiration and the water use efficiency were in the same order of magnitude, independently of nitrogen fertilization; and soil water storage was practically the same from the beginning to the end of the studied cycle
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