939 resultados para nlin.CD
Resumo:
Pure and cadmium doped tin oxide thin films were deposited on glass substrates from aqueous solution of cadmium acetate, tin (IV) chloride and sodium hydroxide by the nebulizer spray pyrolysis (NSP) technique. X-ray diffraction reveals that all films have tetragonal crystalline structure with preferential orientation along (200) plane. On application of the Scherrer formula, it is found that the maximum size of grains is 67 nm. Scanning electron microscopy shows that the grains are of rod and spherical in shape. Energy dispersive X-ray analysis reveals the average ratio of the atomic percentage of pure and Cd doped SnO2 films. The electrical resistivity is found to be 10(2) Omega cm at higher temperature (170 degrees C) and 10(3) Omega cm at lower temperature (30 degrees C). Optical band gap energy was determined from transmittance and absorbance data obtained from UV-vis spectra. Optical studies reveal that the band gap energy decreases from 3.90 eV to 3.52 eV due to the addition of Cd as dopant with different concentrations.
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The conserved stem domain of influenza virus hemagglutinin (HA) is a target for broadly neutralizing antibodies and a potential vaccine antigen for induction of hetero-subtypic protection. The epitope of 12D1, a previously reported bnAb neutralizing several H3 subtype influenza strains, was putatively mapped to residues 76-106 of the CD-helix, also referred to as long alpha helix (LAH) of the HA stem. A peptide derivative consisting of wt-LAH residues 76-130 conjugated to keyhole limpet hemocyanin was previously shown to confer robust protection in mice against challenge with influenza strains of subtypes H3, H1, and H5 which motivated the present study. We report the design of multiple peptide derivatives of LAH with or without heterologous trimerization sequences and show that several of these are better folded than wt-LAH. However, in contrast to the previous study immunization of mice with wt-LAH resulted in negligible protection against a lethal homologous virus challenge, while some of the newly designed immunogens could confer weak protection. Combined with structural analysis of HA, our data suggest that in addition to LAH, other regions of HA are likely to significantly contribute to the epitope for 12D1 and will be required to elicit robust protection. In addition, a dynamic, flexible conformation of isolated LAH peptide may be required for eliciting a functional anti-viral response. Proteins 2013; 81:1759-1775. (c) 2013 Wiley Periodicals, Inc.
Resumo:
In the present work, the effect of Cd on the microstructure, mechanical properties and general corrosion behaviour of AZ91C alloys was investigated. Addition of Cd was found not to be efficient in modifying/refining the microstructure or beta-phase. A morphology change in beta-phase from fine continuous precipitates to discontinuous beta-phase upon the addition of Cd was observed. A marginal increment in mechanical properties was observed. General corrosion behaviour was followed with weight loss measurements, potentiostatic polarisation studies and surface studies in 3.5% sodium chloride solution and 3.5% sodium chloride with 2% potassium dichromate solution. Cd addition deteriorated the corrosion behaviour of AZ91C. This behaviour was attributed to the formation of chunks of beta-phase upon the addition of Cd. AZ91C with refined beta-phase distribution, performed rather better in the NaCl solutions. (C) 2013 Elsevier Ltd. All rights reserved.
Resumo:
By combining first principles density functional theory and electronic as well as lattice Boltzmann transport calculations, we unravel the excellent thermoelectric properties of Zintl phase compounds ACd(2)Sb(2) (where, A = Ca, Ba, Sr). The calculated electronic structures of these compounds show charge carrier pockets and heavy light bands near the band edge, which lead to a large power factor. Furthermore, we report large Gruneisen parameters and low phonon group velocity indicating essential strong anharmonicity in these compounds, which resulted in low lattice thermal conductivity. The combination of low thermal conductivity and the excellent transport properties give a high ZT value of similar to 1.4-1.9 in CaCd2Sb2 and BaCd2Sb2 at moderate p and n-type doping. Our results indicate that well optimized Cd-based Zintl phase compounds have the potential to match the performance of conventional thermoelectric materials.
Resumo:
Novel BioBr/Cd(OH)(2) heterostructures were synthesized by a facile chemical bath method under ambient conditions. A series of BiOBr/Cd(OH)(2) heterostructures were obtained by tuning the Bi/Cd molar ratios. The obtained heterostructures were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Optical properties were studied by UV-visible spectroscopy, diffuse reflectance spectroscopy and photoluminescence (PL). Photocatalytic studies on rhodamine B (RhB) under visible light irradiation showed that the heterostructures are very efficient photocatalysts in mild basic medium. Scavenger test studies confirmed that the photogenerated holes and superoxide radicals (O-2(center dot-)) are the main active species responsible for RhB degradation. Comparison of photoluminescence (PL) intensity suggested that an inhibited charge recombination is crucial for the degradation process over these photocatalysts. Moreover, relative positioning of the valence and conduction band edges of the semiconductors, O-2/O-2(center dot-) and (OH)-O-center dot/H2O redox potentials and HOMO-LUMO levels of RhB appear to be responsible for the hole-specificity of degradation. Photocatalytic recycling experiments indicated the high stability of the catalysts in the reaction medium without any significant loss of activity. This study hence concludes that the heterojunction constructed between Cd(OH)(2) and BiOBr interfaces play a crucial role in influencing the charge carrier dynamics and subsequent photocatalytic activity.
Resumo:
Este estudo visa a expor o caso de sucesso da construção da legislação urbanística federal brasileira por meio do lobby e da participação política de entidades representativas na Comissão de Desenvolvimento Urbano da Câmara dos Deputados.
Resumo:
[ENG]Aiming at an integrated and mechanistic view of the early biological effects of selected metals in the marine sentinel organism Mytilus galloprovincialis, we exposed mussels for 48 hours to 50, 100 and 200 nM solutions of equimolar Cd, Cu and Hg salts and measured cytological and molecular biomarkers in parallel. Focusing on the mussel gills, first target of toxic water contaminants and actively proliferating tissue, we detected significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel flesh by atomic absorption spectrometry. Gene expression profiles, determined in the same individual gills in parallel, revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses, with roughly similar amounts of up- and down-regulated genes. The functional annotation of gill transcripts with consistent expression trends and significantly altered at least in one dose point disclosed the complexity of the induced cell response. The most evident transcriptional changes concerned protein synthesis and turnover, ion homeostasis, cell cycle regulation and apoptosis, and intracellular trafficking (transcript sequences denoting heat shock proteins, metal binding thioneins, sequestosome 1 and proteasome subunits, and GADD45 exemplify up-regulated genes while transcript sequences denoting actin, tubulins and the apoptosis inhibitor 1 exemplify down-regulated genes). Overall, nanomolar doses of co-occurring free metal ions have induced significant structural and functional changes in the mussel gills: the intensity of response to the stimulus measured in laboratory supports the additional validation of molecular markers of metal exposure to be used in Mussel Watch programs
Resumo:
Avalia o relatório elaborado pelo TCU acerca da consulta formulada pela CSSF/CD(TC 046.061/2012‐6). Procura a pacificação de entendimento no âmbito do Congresso Nacional.