Propriedades ópticas de nanopartículas de halogenetos de cobre preparadas in situ em filmes híbridos de sílica

The sol-gel process is a technique based on the hydrolysis and polycondensation of metal alkoxides have been investigated as an alternative for the preparation of vitreous or glassceramic materials, for allowing the obtaining of high-purity materials at low temperatures, and to obtain hybrid materials with different compositions. When ORMOSILs are doped with nanoparticles, are called nanocomposites, and its functionality arises when electrons confined in scale three-dimensional structures near zero are excited. In principle, such materials exhibit discrete energy level, with peaks in the absorption spectrum. Therefore, the glasses doped semiconductor nanocrystals are important candidates for the preparation of optical filters with sharp cut-off, and are being exploited commercially for coloring glasses. This study evaluates the optical properties presented by hybrid films of silica doped with copper nanoparticles. The matrix was prepared using the alkoxides 3-glycidoxypropyltrimethoxysilane (GPTS) and tetraethylorthosilicate (TEOS) doped with Cu2O and hydrolyzed under reflux conditions in two different acidic conditions (HCl and HBr). After thermal treatment at temperatures between 100 °C and 170 °C and/or under the action of commercial black light radiation, CuCl and CuBr present in the hybrid film are transformed into nanoparticles of CuCl or CuBr. The UV-VIS absorption identified the absorption bands, and its variation

Nanocompósitos multifuncionas de fibroína reforçados com biocelulose

This work shows the preparation and characterization of the new nanocomposites based on fibroin and biocellulose. Bacterial cellulose (BC) is an exopolysaccharide produced by bacteria of the genus Gluconacetobacter, which it has identical chemical structure of the cellulose from plants and it has gained attention in the field of research for its unique properties as excellent mechanical properties when dry and hydrated , higher capacity of water retention, moldability , biodegradability and excellent biological affinity . Silk fibroin (SF) is a structural protein present in the cocoon of the silkworm, Bombyx mori, has been identified as suitable for developing optical devices, tissue engineering application, enzyme immobilization, controlled release drug agent biopolymer. Silk fibroin/bacterial cellulose nanocomposite films were prepared impregnating different cellulose charges (0.5 %, 1.0 %, 1.5 %, 2.5 %, 5.0 % and 10.0 %) weight/weight. According mechanical tests and water and Paynes's cup permeability showed that SF/BC 1% nanocomposite has the most relevant results. Poliethylenoglicol (PEG) containing SF films improved optical and mechanical properties when compared to pristine SF film. New SF/BC nanocomposites could be applied in Medicine, as biodegradable packaging and flexible substrates for OLEDs.

Determinação de fósforo em biodiesel utilizando eletrodo quimicamente modificado com nanopartículas de ferro

Once petroleum is na exhaustible source of energy, alternative fuels are having more prominence. A much discussed option for replacing fossil fuels is the use of biofuels derived from oils or fats, especially biodiesel. The biodiesel preparation is through a reaction named transesterification, a reaction of triglycerides with a short chain alcohol with a catalyst, producing a mixture of fatty acid esters and glycerol. According to ANP (National Petroleum Agency) specifications, biodiesel can have contaminants due to the catalyst or oil used on its synthesis, such as phosphorus, wich can damage the catalytic converter and cause significant increase in the particles emission. This project aims to develop na alternative method using chemically modified electrodes with iron nanoparticles for determination of phosphorus in biodiesel. For the formation of the iron nanoparticles film on the surface of a glassy carbon electrode, was used a iron sulfate solution. The film was formed after 10 successive cycles, with a scanning speed of 50 mV s-1 and a potential range of -0,9 to -1,25 V. To reduce possible oxides on the surface and activate the electrode, it has been subjected to a cathodic polarization with a potential of -1,25 V for 15 minutes in a sodium hydroxide solution. In cyclic voltammograms obtained in the study of the speed of scanning, there is an increase in the intensity of the anodic and cathodic current peaks. The cathodic peak current varied linearly with the square root of scan rate, showing that the electrode is controlled by diffusion. After successive additions of phosphate there is a linear variation in the current peak in the concentration range of 1,0 x 10-7 a 1,0 x 10-6 mol L-1. To determine if the concentration of phosphorus in real sample, the method of adding standard was used by adding aliquots of phosphate ions in the solution containing soy biodiesel extracted with ....

Técnica híbrida de plasma para a deposição de filmes de alumina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fabricação e caracterização elétrica de células solares a partir de filmes finos orgânicos

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

Descarte dos componentes de filmes radiográficos e aventais de chumbo utilizados nas clínicas odontológica ou radiológica

Várias resoluções e leis visam minimizar e/ou adequar os resíduos gerados, dentre outros aspectos. Nesse sentido, a Disciplina de Radiologia, funcionários que trabalham no setor e docentes ligados a biossegurança e sustentabilidade ambiental estudaram as referidas normas e leis, além de artigos científicos relacionados ao descarte dos resíduos gerados em radiologia para realizar o descarte correto desses materiais e para orientar e conscientizar os acadêmicos sobre o assunto. Verificou-se que os resíduos gerados com a radiografia convencional são considerados resíduos químicos (tipo B) e devem ser descartado separadamente dos resíduos tipo A (infectantes), C (radioativos), D (comum) e dos E (perfuro-cortantes), visto que podem ser reutilizados, recuperados ou reciclados, e em última instância, podem ser dispostos em aterro de resíduos perigosos Classe I.

Incêndios de petróleo e pretoquímicos: biorremediação de áreas afetadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização de Filmes a-C:H:Cl e a-C:H:Si:Cl produzidos por deposição à vapor químico assistido por plasma (PECVD) e deposição e implantação iônica por imersão em plasma (PIIID)

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Narrativa audiovisual complexa: modular narratives e database narratives

Procura-se nesse trabalho expor as considerações levantadas sobre a modularidade e a temporalidade do filme Pulp Fiction (1994), de Quentin Tarantino, enquadrada por Simons (2008) nas categorias de narrativa audiovisual complexa denominadas modular narratives e database narratives. Com Ricoeur (1983), discutiu-se a sua organização temporal a partir do conceito de tríplice presente em Santo Agostinho, enquanto com Propp (1970) e Cameron (2008) o cará- ter modular dessa narrativa.

O mito Mandela e o sonho de uma nação arco-íris

Nelson Mandela has been an example of fighting and going over the adversities since his prison in 1962 until his election to be the president of South Africa in 1994. His effort against the apartheid in South Africa might be compared to a classical hero according to the anthropological view of Eliade (1972), Campbell (1991; 2007) and Propp’s structuralist perspective (1984). His journey toward heroism and his strategies to get the adhesion of the white minority (Afrikaners) to his purposes of joining the races in South Africa will be analyzed in this article with the theoretical support of the Greimasian semiotics, Propp’s studies (1984) and anthropology. The movie Invictus will be the object of analysis as it shows the moment of Mandela’s social-political fight as the president, with the support of the local rugby team in order to have the racial integration in the country and the political support of the white minority.