IEDA IRMA LAMAS CUNHA
58 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 58
Artigo IPEN-doc 22663 A model of recent sedimentation in the Cananeia–Iguape estuary, Brazil2006 - SAITO, R.T.; FIGUEIRA, R.C.L.; TESSLER, M.G.; CUNHA, I.I.L.Coastal systems, in particular estuaries, are the first depositional environment to receive sediments transported by rivers to the coastal ocean. As a consequence of the geochemical processes involved, a part of the sediment may be deposited in the estuary and the remainder flows into the ocean, being transported and deposited under the influence of tides and maritime currents. This study was carried out in the Cananeia–Iguape estuary on the southern coast of São Paulo state, Brazil. The vertical distribution of 210Pb and 137Cs in sediments has been used as a tool for estimating the sedimentation rates in the coastal environment. Concentrations of 210Pb and 137Cs, as well as heavy metals (lead, zinc, copper) were determined in four sediment cores collected in the Cananeia–Iguape estuary. The estimated sedimentation rates were from 5.3 mm yr−1 to 12.7 mm yr−1. The highest sedimentation rate obtained for Valo Grande corresponds with an accelerated expansion of the sand and clay banks of the Mar Pequeno channel, a growth of the mangrove areas, and a decrease in the depth of the main channel of navigation, a fact that has been affecting the navigation in the area very seriously. The data obtained for the metals showed a sedimentary dynamics in agreement with that obtained in the studies of sedimentation rates, thus contributing to the understanding of the hydrodynamic mechanisms of the system.Artigo IPEN-doc 22612 Determination of trace elements in aerosol samples by instrumental neutron activation analysis1990 - PAIVA, R.P.; MUNITA, C.J.S.; CUNHA, I.I.L.; ROMANO, J.; ALONSO, C.D.Two nuclear techniques, Energy-Dispersive X-Ray Fluorescence Analysis (EDXRF) and Instrumental Neutron Activation Analysis (INAA), were used to analyze aerosol samples collected in the city of Sao Paulo, Brazil. Na, CI, Mn, V, A1, Sm, Mo, W, La, As, Br, Sb, K, Ba, Se, Th, Cr, Rb, Ca, Fe, Ce, and Sc were determined by INAA, and A1, Si, P, S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Hg, and Pb were determined by EDXRF. A preliminary identification of the main source of the atmospheric aerosol was performed based on enrichment factor and correlation coefficient calculations.Artigo IPEN-doc 22589 Distribution of 137Cs, 238Pu and 239 + 240Pu in sediments of the southeastern Brazilian shelf–SW Atlantic margin2006 - FIGUEIRA, RUBENS C.L.; TESSLER, MOYSES G.; MAHIQUES, MICHEL M. de; CUNHA, IEDA I.L.Resumo IPEN-doc 17431 Rate of sedimentary in the coastal systems and on the souther continental plataform of the state of São Paulo, Brazil2000 - TESSLER, M.G.; CUNHA, I.I.L.; SAITO, R.T.; FIGUEIRA, R.C.Capítulo IPEN-doc 01949 Application of neutron activation analysis to trace element in environmental aerosol samples in Sao Paulo1992 - SEPULVEDA MUNITA, C.J.A.; PAIVA, R.P.; CUNHA, I.I.L.Capítulo IPEN-doc 03978 Determination of trace elements in aerosol samples by instrumental neutron activation analysis1990 - PAIVA, R.P.; SEPULVEDA MUNITA, C.J.A.; CUNHA, I.I.L.; ROMANO, J.; ALONSO, C.D.Resumo IPEN-doc 05096 Uso do tracador radioativo de sup(210)Pb para determinar taxas de sedimentacao1997 - SAITO, R.T.; CUNHA, I.I.L.; TESSLER, M.G.Resumo IPEN-doc 10413 sup(210)Pb, sup(226)Ra and sup(137)Cs levels and sedimentation rate in admiralty bay, antarctic peninsula2005 - FIGUEIRA, R.C.L.; MARTINS, C.C.; MONTONE, R.C.; FIGUEIREDO, A.M.G.; TESSLER, M.G.; MAHIQUES, M.M.; CUNHA, I.I.L.Resumo IPEN-doc 03991 A contribution to the characterization of the aerosol sources in Sao Paulo - Brazil1991 - PAIVA, R.P.; SEPULVEDA MUNITA, C.J.A.; CUNHA, I.I.L.; ALONSO, C.D.; ROMANO, J.; MARTINS, M.H.R.Resumo IPEN-doc 05284 Determinacion de elementos inorganicos y aniones en agua de lluvia de San Pablo1993 - PAIVA, R.P.; SEPULVEDA MUNITA, C.J.A.; CUNHA, I.I.L.; PIRES, M.A.F.; TABACNIKS, M.H.