Compostos derivados de benzilcobaloximas: estudo por espectrometria de massas, análise térmica e eletroquímica

Pós-graduação em Química - IQ

Storage of 'Espada' mango fruits in modified atmosphere and cooling: effects on conservation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoelectrochemical Hydrogen Generation and Concomitant Organic Dye Oxidation under TiO2 Nanotube

The present work describes the photoelectrochemical hydrogen generation during a photodegradation of an organic compound. For this, it was chosen the reactive black 5 dye as a model of organic pollutant and its oxidation under TiO2 nanotube in a two compartment cell. The photoelectrocatalysis is conducted in 0.1 mol L-1 Na2SO4 pH 6 medium under photoanode biased at +1.0 V (SCE) and activated by UV and visible light using 150W Xe-Arc lamp (Oriel) and 125 W Hg lamp (Osram). The concomitant hydrogen production was monitored at cathodic compartment using a Pt cathode. Using optimized condition of Na2SO4 0.1 mol L-1 pH 6 as supporting electrolyte, applied potential of +1.0V it was verified 100% of discoloration and 72% of TOC removal of 1.0 x 10(-5) mol L-1 Reactive Black 5 dye after 120 min of treatment (rate constant of 10.6 x10(-2) min(-1)). The concomitant hydrogen generation was 44% in this condition.

Role of the reactive atmosphere during the sol-gel synthesis on the enhancing of the emission quantum yield of urea cross-linked tripodal siloxane-based hybrids

Transparent monoliths and films of urea cross-linked tripodal siloxane-based hybrids (named tri-ureasils) were prepared by the sol-gel process, under controlled atmosphere (inside a glove box) and ambient conditions and their structure and optical features were compared. X-ray diffraction data point out that all the materials are essentially amorphous and Si-29 NMR reveal an increase in the condensation degree (0.97) for the hybrids prepared under controlled atmosphere relatively to that found for those prepared under ambient conditions (0.84-0.91). The tri-ureasils are white light emitters under UV/Visible excitation (from 250 to 453 nm) being observed for the composites prepared inside the glove box a significant enhancement (60-80 %) of the absorption coefficient and higher emission quantum yield values (similar to 0.27 and similar to 0.20 for monoliths and films, respectively) relatively to those synthesized under ambient condition.

Transenamel and Transdentinal Penetration of Hydrogen Peroxide Applied to Cracked or Microabrasioned Enamel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Some properties of intermetallic compounds of Sn with noble metals relevant for hydrogen electrocatalysis

Using density functional theory and a model developed in our own group, we have investigated the suitability of three intermetallic compounds - AuSn, PdSn, and PtSn - as electrode materials for hydrogen oxidation in fuel cells, focusing on their CO tolerance and their catalytic properties. All three metals were found to have lower susceptibility to be poisoned by CO compared to platinum, but only PtSn promises to be a good catalyst for hydrogen oxidation. (C) 2013 Elsevier Ltd. All rights reserved.

Dynamics of Space Particles and Spacecrafts Passing by the Atmosphere of the Earth

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bleaching effectiveness, hydrogen peroxide diffusion, and cytotoxicity of a chemically activated bleaching gel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Concentrations of and application protocols for hydrogen peroxide bleaching gels: Effects on pulp cell viability and whitening efficacy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Concentration and Activation on Hydrogen Peroxide Diffusion through Dental Tissues In Vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hydrogen sulphide removal from air by biotrickling filter using open-pore polyurethane foam as a carrier

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Monitoring of hydrogen sulfide via substrate-integrated hollow waveguide mid-infrared sensors in real-time

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Thermodynamic and economic analysis of hydrogen production integration in the Brazilian sugar and alcohol industry

One of the biggest challenges today is to develop clean fuels, which do not emit pollutant and with viable implementation. One of the options currently under study is the hydrogen production process. In this context, this work aims to study the technical and economical aspects of the incorporation process of hydrogen producing by ethanol steam reforming in the sugar cane industry and MCFC (molten carbonate fuel cell) application on it to generate electric power. Therefore, it has been proposed a modification in the traditional process of sugar cane industry, in order to incorporate hydrogen production, besides the traditional products (sugar, ethylic, hydrated and anhydric alcohol). For this purpose, a detailed theoretical study of the ethanol production process, describing the considerations to incorporate the hydrogen production will be performed. After that, there will be a thermodynamic study for analysing the innovation of this production chain, as well as a study of economic engineering to allocate the costs of products of the new process, optimising it and considering the thermoeconomics as being as an analysis tool. This proposal aims to improve Brazil's position in the ranking of international biofuels, corroborating the nation to be a power in the hydrogen era. (C) 2013 Elsevier Ltd. All rights reserved.

On the hydrogen bonding between N-methylformamide and acetone and tetrahydrofuran

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)