989 resultados para Mica.
Resumo:
The mineralogy and origin of micas were investigated in incipient soils surrounding a modem alkaline-saline lake of Nhecolandia, a sub-region of Pantanal wetland. Soils were sampled along a toposequence and analyzed by XRD, TEM-EDS, and ICP-MS. The studied micas, mainly concentrated in a green horizon, are dioctahedral, strongly associated with Fe(3+) and Al, and interstratified with smectite layers. Classification of individual crystals shows that glauconite and Fe-illite are the dominant micas, but one crystal of illite was recognized. Si-rich amorphous materials are associated with small crystallites in the mica-enriched horizon. A recent study shows that water samples from the studied lake and the surrounding water table have high pH, negative Eh, temperatures up to 40 C. high concentration of K. and low concentration of Si(OH)(4). Experimental studies of micas synthesis reported in the literature show that similar water conditions allow for dioctahedral mica crystallization from initial precipitation of amorphous hydroxides. Therefore, water characteristics combined with presence of Si-rich amorphous materials in the mica-enriched horizon suggest that the micas of the study area are neoformed. The alternated origin of illite, glauconite, and Fe-illite mixed-layer minerals probably occurs due to seasonal variations of pH. temperature, and chemical composition of waters in microenvironments, since the changes at this scale are possibly faster and more extreme. (C) 2010 Elsevier B.V. All rights reserved.
Resumo:
The origin of the saline lakes in the Pantanal wetland has been classically attributed to processes occurring in past periods. However, recent studies have suggested that saline water is currently forming from evaporative concentration of fresh water, which is provided annually by seasonal floods. Major elements (Ca, Mg, K) and alkalinity appear to be geochemically controlled during the concentration of waters and may be involved in the formation of carbonates and clay minerals around the saline lakes. The mineralogy of soils associated with a representative saline lake was investigated using XRD, TEM-EDS, and ICP-MS in order to identify the composition and genesis of the secondary minerals suspected to be involved in the control of major elements. The results showed that Ca, Mg, and K effectively undergo oversaturation and precipitation as the waters become more saline. These elements are incorporated in the authigenically formed carbonates, smectites, and micas surrounding the saline lake. The control of Ca occurs by precipitation of calcite and dolomite in nodules while Mg and K are mainly involved in the neoformation of Mg-smectites (stevensitic and saponitic minerals) and, probably, iron-enriched micas (ferric-illite) in surface and subsurface horizons. Therefore, our study confirms that the salinity of Pantanal, historically attributed to inheritance from former regimes, has a contribution of current processes. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Smectite formation in alkaline-saline environments has been attributed to direct precipitation from solution and/or transformation from precursor minerals, but these mechanisms are not universally agreed upon in the literature. The objective of this work was to investigate the mineralogy of smectites in the soils surrounding a representative alkaline-saline lake of Nhecolandia, a sub-region of the Pantanal wetland, Brazil, and then to identify the mechanisms of their formation. Soils were sampled along a toposequence and analyzed by X-ray diffraction, transmission electron microscopy-energy dispersive X-ray analysis, and inductively coupled plasma-mass spectrometry. Water was collected along a transect involving the studied toposequence and equilibrium diagrams were calculated using the databases PHREEQC and AQUA. The fine-clay fraction is dominated by smectite, mica, and kaolinite. Smectites are concentrated at two places in the toposequence: an upper zone, which includes the soil horizons rarely reached by the lake-level variation; and a lower zone, which includes the surface horizon within the area of seasonal lake-level variation. Within the upper zone, the smectite is dioctahedral, rich in Al and Fe, and is classified as ferribeidellite. This phase is interstratified with mica and vermiculite and has an Fe content similar to that of the mica identified. These characteristics suggest that the ferribeidellite originates from transformation of micas and that vermiculite is an intermediate phase in this transformation. Within the lower zone, smectites are dominantly trioctahedral, Mg-rich, and are saponitic and stevensitic minerals. In addition, samples enriched in these minerals have much smaller rare-earth element (REE) contents than other soil samples. The water chemistry shows a geochemical control of Mg and saturation with respect to Mg-smectites in the more saline waters. The REE contents, water chemistry, and the presence of Mg-smectite where maximum evaporation is expected, suggest that saponitic and stevensitic minerals originate by chemical precipitation from the water column of the alkaline-saline lake.
Resumo:
P>Antibody-mediated rejection (AMR) requires specific diagnostic tools and treatment and is associated with lower graft survival. We prospectively screened C4d in pancreas (n = 35, in 27 patients) and kidney (n = 33, in 21 patients) for cause biopsies. Serum amylase and lipase, amylasuria, fasting blood glucose (FBG) and 2-h capillary glucose (CG) were also analysed. We found that 27.3% of kidney biopsies and 43% of pancreatic biopsies showed C4d staining (66.7% and 53.3% diffuse in peritubular and interacinar capillaries respectively). Isolated exocrine dysfunction was the main indication for pancreas biopsy (54.3%) and was followed by both exocrine and endocrine dysfunctions (37.1%) and isolated endocrine dysfunction (8.6%). Laboratorial parameters were comparable between T-cell mediated rejection and AMR: amylase 151.5 vs. 149 U/l (P = 0.075), lipase 1120 vs. 1288.5 U/l (P = 0.83), amylasuria variation 46.5 vs. 61% (P = 0.97), FBG 69 vs. 97 mg/dl (P = 0.20) and 2-h CG maximum 149.5 vs. 197.5 mg/dl (P = 0.49) respectively. Amylasuria values after treatment correlated with pancreas allograft loss (P = 0.015). These data suggest that C4d staining should be routinely investigated when pancreas allograft dysfunction is present because of its high detection rate in cases of rejection.
Resumo:
We studied the anisotropic aggregation of spherical latex particles dispersed in a lyotropic liquid crystal presenting three nematic phases; calamitic, biaxial, and discotic. We observed that in the nematic calamitic phase aggregates of latex particles are formed, which become larger and anisotropic in the vicinity of the transition to the discotic phase, due to a coalescence process. Such aggregates are weakly anisotropic and up to 50 mu m long and tend to align parallel to the director field. At the transition to the discotic phase, the aggregates dissociated and re-formed when the system was brought back to the calamitic phase. This shows that the aggregation is due to attractive and repulsive forces generated by the particular structure of the nematic phase. The surface-induced positional order was investigated by surface force apparatus experiments with the lyotropic system confined between mica surfaces, revealing the existence of a presmectic wetting layer around the surfaces and oscillating forces of increasing amplitude as the confinement thickness was decreased. We discuss the possible mechanisms responsible for the reversible aggregation of latex particles, and we propose that capillary condensation of the N(C) phase, induced by the confinement between the particles, could reduce or remove the gradient of order parameter, driving the transition of aggregates from solidlike to liquidlike and gaslike.
Resumo:
The walkeriana species-group of iridescent Euhesma bees is described with the following nine species considered new: E. allunga, E. banksia, E. bronzus, E. dongara, E. lobata, E. spinola, E. sybilae, E. viridescens and E. xana. Two new synonymies are proposed: E. mica (Cockerell) with E. neglectula (Cockerell), and E. halictoides (Rayment) with E. latissima (Cockerell). A key enables the separation of species, and distributions are mapped.
Resumo:
Diante de uma sociedade mais din??mica e complexa, a ado????o de uma pol??tica permanente de desenvolvimento do capital humano ?? o caminho para a supera????o dos desafios no setor p??blico. Dessa forma ?? poss??vel ofertar servi??os de excel??ncia aos cidad??os, bem como promover a inova????o e a melhoria na qualidade da gest??o p??blica. O presente Boletim apresenta uma sele????o de publica????es, dentre a vasta quantidade de obras sobre o tema existentes no acervo da Biblioteca Graciliano Ramos, que retratam os obst??culos existentes para o desenvolvimento de pessoas no servi??o p??blico, com o objetivo de convergir as necessidades e anseios dos quadros funcionais ??s necessidades organizacionais
Resumo:
A iniciativa, implementada em Minas Gerais, ?? considerada uma das maiores experi??ncias de teleassist??ncia sustent??vel no mundo, servindo de modelo para outras a????es similares no Brasil e na Am??rica Latina. Sua cria????o representa uma nova atividade econ??mica, gerando um novo campo de trabalho e uma nova ??rea de pesquisa, tanto na sa??de quanto na ??rea de TI. Os resultados alcan??ados impactaram positivamente a melhoria do acesso da popula????o a servi??os especializados e a fixa????o de profissionais em localidades remotas
Resumo:
O projeto Pensando o Direito tem por objetivo qualificar o trabalho jur??dico da Secretaria de Assuntos Legislativos do Minist??rio da Justi??a, abrindo espa??o para a absor????o da produ????o acad??mica de ponta e fortalecendo seu trabalho de elabora????o normativa. O projeto ?? realizado pela Secretaria de Assuntos Legislativos do Minist??rio da Justi??a (SAL/MJ), por meio de acordo de coopera????o t??cnica com o Programa das Na????es Unidas para o Desenvolvimento (PNUD) ??? acordo BRA/07/004: Democratiza????o de Informa????es no Processo de Elabora????o Normativa - e implementado por meio de cartas-acordo com institui????es de ensino e pesquisa de todo o pa??s. Foram firmadas parcerias, por meio de seis sele????es p??blicas, com institui????es acad??micas de ensino e pesquisa em 42 ??reas tem??ticas previamente definidas pela SAL/MJ. O objetivo ?? o fomento ?? pesquisa de car??ter emp??rico e multidisciplinar de assuntos jur??dicos pouco debatidos na academia, mas em discuss??o na sociedade. De 2007 a 2010, foram apresentadas 265 propostas de projetos de pesquisa por 152 institui????es e, dessas, 43 foram aprovadas
Resumo:
Com o objetivo de elevar a qualidade do ensino superior do pa??s, em 2006 o Minist??rio da Educa????o (MEC) iniciou um movimento de ???reinven????o processual??? em tr??s dimens??es: i) jur??dica, com a reformula????o da legisla????o aplic??vel aos processos regulat??rios da educa????o superior; ii) organizacional, implementando mudan??as na din??mica e no desenho das rotinas de trabalho; e iii) tecnol??gica, com a implementa????o do sistema eletr??nico e-MEC de operacionaliza????o dos procedimentos de regula????o. A tr??plice iniciativa permitiu, a um s?? tempo, trazer seguran??a jur??dica, transpar??ncia, credibilidade e celeridade ao processo. Isso possibilitou a cria????o de ambiente prop??cio ao salto qualitativo que o MEC pretendia dar em rela????o tanto ao condicionamento do funcionamento de institui????es e cursos superiores quanto ?? comprova????o da excel??ncia de sua opera????o. O objetivo final??stico foi atingido de maneira satisfat??ria, podendo-se dizer que est?? em curso a institucionaliza????o de uma cultura da qualidade da educa????o superior
Resumo:
O pagamento dos benef??cios sociais, efetuado no guich?? de caixa das ag??ncias, era um processo lento e oneroso ao cidad??o e ?? CAIXA. Envolvia elevado quantitativo de atendentes e significativo tempo para a execu????o de rotinas inerentes, principalmente no que diz respeito ?? qualifica????o e ?? identifica????o do trabalhador, ao tratamento da documenta????o e ?? coleta de assinatura no documento de pagamento, gerando elevado custo operacional. Em 1995, a CAIXA lan??ou o Cart??o do Trabalhador, que permitia o acompanhamento de lan??amentos do Fundo de Garantia do Tempo de Servi??o (FGTS) e acesso ao saldo de cotas de sua participa????o no Programa de Integra????o Social (PIS), mas n??o tinha a funcionalidade de saque de benef??cios e n??o atendia os benefici??rios do Abono Salarial e do Seguro- Desemprego. A necessidade de aperfei??oar e integrar os processos de atendimento e pagamento desses produtos sociais levou ?? cria????o do Cart??o do Cidad??o, que proporcionou melhoria significativa na qualidade do atendimento ao cidad??o e minimizou os custos operacionais
Resumo:
O estudo de caso aborda o gerenciamento das crises decorrentes do fen??meno das inunda????es no Vale do Itaja??, em Santa Catarina. Na narrativa apresentada, h?? informa????es sobre a evolu????o da ocupa????o do territ??rio e os respectivos desdobramentos na din??mica ambiental, com ??nfase nas a????es que o setor p??blico adotou para enfrentar os desastres. Os eventos clim??ticos ocorridos em 2008 e 2011 s??o detalhados, com o objetivo de caracterizar a preven????o e a capacidade de resposta que o governo e a sociedade demonstraram
Resumo:
Este livro apresenta uma an??lise de informa????es consolidadas e sistematizadas sobre experi??ncias vencedoras do Concurso de Inova????es na Gest??o P??blica Federal entre os anos de 1996 a 2000, para oferecer algumas sugest??es para o debate aos que est??o engajados no processo de aperfei??oamento do setor p??blico ou se interessam pelo tema
Resumo:
O estudo de caso trata da resposta ?? crise gerada pelo Furac??o Katrina em Nova Orleans/EUA dada pelos ??rg??os p??blicos encarregados de atuar em situa????es de emerg??ncia. A narrativa concentra-se na rela????o cr??tica entre a Ag??ncia Federal de Gest??o de Emerg??ncias - FEMA, coordenadora geral dos esfor??os federais para responder ao desastre, e o Departamento de Defesa ??? DOD. O objetivo deste caso ?? entender a din??mica de colabora????o que se instalou entre os ??rg??os encarregados de dar ampla e pronta resposta ao Katrina, e, de maneira mais geral, verificar o funcionamento em condi????es emergenciais de redes formadas por ??rg??os federais, estaduais e locais. O caso suscita discuss??es em sala de aula que podem desencadear an??lises sobre o funcionamento da coordena????o da rede encarregada pela resposta ?? crise, o papel da burocracia em momentos emergenciais, a import??ncia da lideran??a, e o efeito da cultura organizacional durante a colabora????o
Resumo:
A fun????o capacita????o passa a ser concebida dentro de uma nova proposta materializada no modelo Pool de Capacita????o que tem por objetivos aumentar a capacidade do processo, alinhar a ??rea de recursos humanos ??s estrat??gias institucionais e sintoniz??-la com a cultura organizacional e os cen??rios externos. O processo de capacita????o passa a operar de forma sist??mica, desconcentrada e articulada em rede interna e externa