25 resultados para Buarque, Chico, 1944 - . Budapeste
Resumo:
Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM)+ data have been successfully employed in the field of mineral exploration to identify key minerals over arid and semi-arid terrains. However, redundant vegetation and cloud may seriously interfere with the discrimination of the minerals with diagnostic features. Therefore, in this study, we use masking technique to eliminate the negative influence of vegetation and cloud and Crosta technique to identify the diagnostic features of hydroxyl-minerals, carbonate-minerals and iron oxides. Then the anomalies were endowed with special colours and overlapped with the remote-sensing and geochemical data, overlaying images as remote-sensing anomalies. The mineral exploration work was carried through by synthetic analysis of the remote-sensing images, geochemical data and structures. Finally, areas with high correlation between the occurrence of hydrothermal alteration and presence of main faults and geochemical anomalies were considered as mineral exploration targets worthy of further detailed exploration programmes.
Resumo:
PCBsPAHsPAHsPCBsPAHsPCBs 1.--PCBs5185848 pg/g1715 pg/gPCBsr=0.61p0.01PCBs 2. 19142004PAHsPCBs90PAHsPCBsPAHsPCBs19141932PAHsPCBs19321962PAHsPCBs1932194419561962PAHsPCBs1962PAHsPCBsPAHs19201944PAHs19441980//19802004 3.PAHsPCBsDDTsHCHsPAHsPCBsDDTsHCHs149.0393.4 ng/g360.81728.3 pg/g462.22007.3 pg/g4.3133.8 ng/gPAHsPCBsDDTsHCHsPAHsPAHs//DDTsHCHsDDTsHCHs 4.POPsPOPsDDTsHCHs 12PAHsPCBsPOPs3PAHsDDTsHCHs
Resumo:
Sixteen polycyclic aromatic hydrocarbons (PAHs) and 28 polychlorinated biphenyls (PCBs) were measured at a 2-cm interval in a core sample from the middle of the southern Yellow Sea for elucidating their historical variations in inflow and sources. The chronology was obtained using the Pb-210 method. PAHs concentrations decreased generally with depth and two climax values occurred in 14-16 cm and 20-22 cm layers, demonstrating that the production and usage of PAHs might reach peaks in the periods of 1956-1962 and 1938-1944. The booming economy and the navy battles of the Second World War might explain why the higher levels were detected in the two layers. The result of principal component analysis (PCA) revealed that PAHs were primarily owing to the combustion product. Down-cored variation of PCB concentrations was complex. Higher concentrations besides the two peaks being the same as PAHs were detected from 4 to 8 cm, depositing from 1980 to 1992, which probably resulted from the disposal of the out-dated PCB-containing equipment. The average Cl percentage of PCBs detected was similar to that of the mixture of Aroclor 1254 and 1242, suggesting they might origin from the dielectrical and heat-transfer fluid. The total organic carbon (TOC) content played a prevalent role in the adsorption of high molecular weight PAHs (>= 4-ring), while no obvious relationship among total PCBs, the concentration of congeners, and TOC was found.
