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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of spatio-temporal distribution of soil moisture on a lowland dipterocarp forest at Pasoh Forest Reserve in Peninsular Malaysia / 土壌水分の時空間分布が半島マレーシアパソ森林保護区低地フタバガキ林に与える諸影響

Marryanna, Lion 26 March 2018 (has links)
京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13181号 / 論農博第2860号 / 新制||農||1061(附属図書館) / 学位論文||H30||N5103(農学部図書室) / (主査)教授 小杉 緑子, 教授 北山 兼弘, 教授 舟川 晋也 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
2

Os valores de referência, assinatura isotópica de fatores de enriquecimento de metais Pb e pesados em solos que cercam uma baía do ambiente impactado no Brasil. / Reference values, isotopic signature of Pb and heavy metal enrichment factors in soils surrounding an environmentally-impacted bay in Brazil

SANTOS, Nielson Machado dos 06 July 2015 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-08-17T12:29:29Z No. of bitstreams: 1 Nielson Machado dos Santos.pdf: 2159134 bytes, checksum: 0924bbce3bea148e3c14b840a9443026 (MD5) / Made available in DSpace on 2016-08-17T12:29:29Z (GMT). No. of bitstreams: 1 Nielson Machado dos Santos.pdf: 2159134 bytes, checksum: 0924bbce3bea148e3c14b840a9443026 (MD5) Previous issue date: 2015-07-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work was carried out to investigate the possible influence of human activities on heavy metal concentrations, by enrichment factor and isotopic signature of Pb and determine the natural levels of heavy metals in the vicinity Todos os Santos Bay-BA (BTS). For this, two sampling design of the soil around the BTS were realized. The first sampling 114 topsoil samples (0.0 - 0.2 m depth) were collected from 38 samplings sites and the concentrations of Pb, Zn, As, Cd, and Hg were determined by ICP-OES or AA-FIAS after microwave sample digestion. Results showed that mean values for heavy metal concentrations in soils (mg kg-1) followed the order Pb (39.45) > Zn (12.52) > As (1.95) > Cd (0.23) > Hg (0.09). The mean natural concentrations of heavy metals found in the soils of an important economic region of Brazil’s were generally lower than those reported in the national and international literature, with exception Pb concentration that was higher than all compared soils.The quality reference values (QRvs) calculated for the TSB based on the 75th percentile, were as follows (mg kg−1): Pb (54.37); Cr (36.55); Zn (10.40); Cu (7.10); Ni (4.05); Co (0.38); Cd (0.30). The second sampling six soil profiles were collected, the samples were collected from different horizons, totaling 44 samples. Soil pits were dug until 2 m or until the parent material (C horizon) was reached.The soil samples were microwave digested in the mixture of HNO3, H2O2 using the method described by Sah and Miller (1992). Concentrations of Pb and the isotopes 204Pb, 206Pb, 207Pb and 208Pb were measured on an inductively coupled plasma (quadrupole) mass spectrometry. Pb concentrations varied from 3.2 to 44.1 mg kg−1 with an average concentration of 13.65 mg kg−1. In general the samples feature a wide range of Pb isotope ratios, ranging from 36.71 to 47.38 for 208Pb/204Pb, 16.86 to 20.59 for 206Pb/204Pb, 1.10 to 1.31 for 206Pb/207Pb and a ranged slightly from 15.00 to 15.65 for 207Pb/204Pb. The PCA performed identified that Pb, Zn, and Cd were associated with the same factor (F1) and had chiefly anthropogenic origin whereas Pb and Zn have also contributions from both sources (natural, lithogenic and anthropogenic). The As and Hg concentrations (F2) were related to the natural component; the parent material underlying the soils (igneous-metamorphic rocks) seemingly confirm this hypothesis. The natural concentrations of heavy metals in soils of TSB had the following decreasing order: Pb > Cr > Zn > Cu > Ni > Co > Cd. Pb concentration in all soil profiles not seem have been influenced by the abandoned lead smelter plant located in the municipality of Santo Amaro da Purificação-BA. The distinct Pb isotopic compositions were clearly related to the different exposure of the sampling sites in relation to atmospheric deposition and geological parent material. / Este trabalho foi realizado para investigar a possível influência das atividades humanas sobre as concentrações de metais pesados, por fator de enriquecimento e assinatura isotópica de Pb e determinar os níveis naturais de metais pesados ​​nas imediações Todos os Santos Bay-BA (BTS). Para isso, duas projecto de amostragem do solo ao redor da BTS foram realizados. A primeira amostragem de 114 amostras de solo superficial (0,0-0,2 m de profundidade) foram coletadas de 38 amostragens sites e as concentrações de Pb, Zn, As, Cd, Hg e foram determinados por ICP-OES ou AA-FIAS após digestão de amostras de microondas. Os resultados mostraram que os valores médios para as concentrações de metais pesados ​​em solos (mg kg-1) seguido a ordem Pb (39,45)> Zn (12,52)> Como (1,95)> Cd (0,23)> Hg (0,09). As concentrações médias naturais de metais pesados ​​encontrados nos solos de uma importante região econômica do Brasil de foram em geral menores que os relatados na literatura nacional e internacional, com exceção Pb concentração que era maior do que todos em comparação soils.The valores de referência de qualidade (QRvs) calculada para TSB a partir do percentil 75, foram as seguintes (mg kg-1): Pb (54,37); Cr (36,55); Zn (10,40); Cu (7,10); Ni (4,05); Co (0,38); Cd (0,30). A segunda amostragem seis perfis de solo foram coletadas, as amostras foram coletadas de horizontes diferentes, totalizando 44 amostras. Poços de solo foram escavadas até 2 m ou até que o material de origem (C horizonte) foi amostras de solo foram reached.The microondas digerido na mistura de HNO3, H2O2, utilizando o método descrito por Sah e Miller (1992). As concentrações de Pb e os isótopos 204Pb, 206Pb, 207Pb e 208Pb foram medidos em uma espectrometria de massa com plasma indutivamente acoplado (quadrupolo). Concentrações de Pb variou de 3.2 para 44,1 mg kg-1 com uma concentração média de 13,65 mg kg-1. Em geral, as amostras apresentam uma vasta gama de relações isotópicas Pb, variando 36,71-47,38 para 208Pb / 204Pb, 16,86-20,59 para 206Pb / 204Pb, 1,10-1,31 para 206Pb / 207Pb e uma variou ligeiramente 15,00-15,65 para 207Pb / 204Pb . O PCA realizada identificou que Pb, Zn e Cd foram associados com o mesmo fator (F1) e teve origem principalmente antropogénica Considerando Pb e Zn também tem contribuições de ambas as fontes (naturais, litogênicos e antropogênicos). As concentrações de Hg e Como (F2) estavam relacionados com a componente natural; o material de origem subjacentes aos solos (ígnea-rochas metamórficas) aparentemente confirmar esta hipótese. As concentrações naturais de metais pesados ​​em solos de TSB teve a seguinte ordem decrescente: Pb> Cr> Zn> Cu> Ni> Co> Cd. Concentração de Pb em todos os perfis de solo não parecem ter sido influenciados pela planta fundição de chumbo abandonada localizada no município de Santo Amaro da Purificação-BA. As composições isotópicas de Pb distintas foram claramente relacionadas com a diferente exposição dos pontos de amostragem em relação à deposição atmosférica e material de origem geológica.

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