Encontrados 92 documentos, a visualizar página 1 de 10
The solvent extraction performance of N,N’-dimethyl-N,N’-dibutylmalonamide towa...
Paiva, A. P.; Carvalho, G. I.; Costa, M. Clara; Costa, Ana M. Rosa da; Nogueira, C. A.The solvent extraction performance of N,N’-dimethyl-N,N’-dibutylmalonamide (DMDBMA) in 1,2-dichloroethane (1,2-DCE) towards platinum(IV) and palladium(II) in hydrochloric acid media was systematically evaluated. Pt(IV) extraction (%E) increases with the HCl concentration in the aqueous phases, being always higher than 72%, whereas Pd(II) extraction decreases from 65% at 1 M HCl to 22% at 8 M HCl. Several stripp...
Recovery of platinum and palladium from chloride solutions by a thiodiglycolami...
Paiva, A. P.; Carvalho, G. I.; Costa, M. Clara; Costa, Ana M. Rosa da; Nogueira, C. A.The liquid-liquid extraction of platinum(IV) and palladium(II) from hydrochloric acid media was carried out using N,N’-dimethyl-N,N’-dicyclohexylthiodiglycolamide (DMDCHTDGA) in 1,2-dichloroethane (1,2-DCE). Pt(IV) is efficiently extracted from 5 M HCl onwards (%E = 97%), whereas Pd(II) is quantitatively recovered from 1 to 8 M HCl solutions. Both Pt(IV) and Pd(II) can be successfully stripped from the loaded o...
Avaliação do Estado Redox Plasmático na Criança
Diogo, L.; Drago, H.; Fernandes, A.; Carvalho, G.; Canha, J.; Mota, H. C.; Proença, T.; Oliveira, C.A avaliação do estado redox plasmático, que consiste na determinação simultânea das concentrações plasmáticas de lactato, piruvato, acetoacetato e P-hidroxibutirato, é útil no rastreio das doenças hereditárias do metabolismo por défice energético. O seu doseamento exige rigorosas condições de colheita e processamento das amostras. Fez-se o estudo de 70 crianças sem doença metabólica com idades compreendidas ent...
Recovery of precious metals from exhausted automotive catalysts by leaching and...
Nogueira, C. A.; Carvalho, G. I.; Costa, Maria Clara; Costa, Ana M. Rosa da; Paiva, A. P.Platinum group metals (PGM’s) are precious and rare metals used in many existing and emerging technologies such as electronics, catalysts, energy and medical appliances, among others. PGM’s applications and demand are growing rapidly, and their supply is short and considered critical. Recycling of residues containing PGM’s is therefore mandatory, in order to allow the continuity of supplying. The main market sh...
New extractants for separation of platinium-group metals from chloride solution...
Paiva, A. P.; Carvalho, G. I.; Schneider, A. L.; Costa, Maria Clara; Costa, A. M.; Assunção, A. F.; Nogueira, C. A.In this paper some results on the application of four N,N’-tetrasubstituted malonamide derivatives for the extraction and separation of platinum-group metals (PGMs) are presented. The above mentioned extractants were specifically synthesized in order to evaluate their efficiency for the extraction of a specific metal, or group of metals, from aqueous chloride matrices. Different behaviours were obtained towards...
Sample richness and genetic diversity as drivers of chimera formation in nSSU m...
Fonseca, V. G.; Nichols, B.; Lallias, D.; Quince, C.; Carvalho, G .R.; Power, Deborah; Creer, S.Eukaryotic diversity in environmental samples is often assessed via PCR-based amplification of nSSU genes. However, estimates of diversity derived from pyrosequencing environmental data sets are often inflated, mainly because of the formation of chimeric sequences during PCR amplification. Chimeras are hybrid products composed of distinct parental sequences that can lead to the misinterpretation of diversity es...
Systematic and evolutionary insights derived from mtDNA COI barcode diversity i...
Matzen da Silva, J.; Creer, S.; Santos, A. dos; Costa, A. C.; Cunha, M. R.; Costa, Filipe O.; Carvalho, G. R.Decapods are the most recognizable of all crustaceans and comprise a dominant group of benthic invertebrates of the continental shelf and slope, including many species of economic importance. Of the 17635 morphologically described Decapoda species, only 5.4% are represented by COI barcode region sequences. It therefore remains a challenge to compile regional databases that identify and analyse the extent and pa...
Degradabilidade ruminal da matéria seca, da proteína bruta e da fração fibrosa ...
Pires,A.J.V.; Reis,R.A.; Carvalho,G.G.P.; Siqueira,G.R.; Bernardes,T.F.; Ruggieri,A.C.; Roth,M.T.P.Avaliou-se a degradação da matéria seca (MS), da proteína bruta (PB), da fibra em detergente neutro (FDN), da fibra em detergente ácido (FDA) e da hemicelulose das silagens de milho, de sorgo e de Brachiaria brizantha. Foram utilizados três novilhos Nelore, machos, fistulados no rúmen, com média de peso de 200kg. Em cada animal foram incubadas amostras das três silagens nos tempos de 0, 6, 12, 24, 36, 48, 72 e ...
PRINCIPAIS INDICADORES: MACROECONÔMICOS, v. 3, n. 20, 2010.
CARVALHO, G. R.; CARNEIRO, A. V.; TRAVASSOS, G. F.; PINHA, L. C.2010
Cloração de água para propriedades rurais.
OTENIO, M. H.; CARVALHO, G. L. O. de; SOUZA, A. M. de; NEPOMUCENO, R. S. C.2010
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||