Preparação e caracterização de vidros contendo nanopartículas de Ag

This work consists of preparation and characterization of glasses containing transition noble metals and the study of optical properties of such materials. The glasses were prepared by quenching of the glass melt followed by heat treatment and polishing of the monoliths. The structural characterization of glasses was made using differential thermal analysis, X-ray, Raman and infrared spectroscopies, while the optical properties were studied by UV-Vis and M-Lines spectroscopies. Preliminary results have shown that the color of the glasses is dependent on both concentration of silver and the melting temperature of the melt. Controlled heat treatments have been used to induce the crystallization of Ag nanoparticles within the glass. The study of crystallization was accompanied by electron microscopy and UV-Vis spectroscopy. Data from electron diffraction, as well as chemical analysis, EDX, were obtained using a transmission electron microscope. EDX data have shown that the atomic percentage of Ag is higher on the nanoparticle. X-ray diffraction was used in order to characterize the composition of the crystals and cubic AgCl was identified as the main crystallized nanophase obtained after annealing

Levantamento e análise dos padrões de qualidade nacionais e internacionais estabelicidos para reuso de efluentes e aproveitamento de água de chuva para fins não potáveis em áreas urbanas

The objective of this work is present and analyze the standards and guidelines associated with the protection of health of the user of waters less noble, for purposes other than drinking, and more specifically, the criteria descriptors of quality of these waters and the assessment of microbiological risk associated to its use aiming to establish, with bases and scientific criteria, the tolerable risk and the definition of standards for the microbiological quality. To this end, the author makes use of investigative exploratory method based on bibliographic survey and acquisition and posterior analysis, presentation and discussion about the topics discussed. The final text may inform and subsidise decisions regarding the definition of new values (preparation of new standards) and in the definition of appropriate technology

Considerações gerais sobre a aplicação de esterco no processo de compostagem dos resíduos de poda e capina

In the category of the solid waste, are included the yard solid waste, this kind of solid waste are noble raw material and uncontaminated being recycled through the composting processing. Inside this context, it was studied the influence of horse manure in yard solid waste composting process, analyze the viability to compost the yard solid waste in UNESP Bela Vista. It was made four piles of composting, two of them are composed only by yard solid waste and the others are composed by horse manure and yard solid waste. The experiments were operated during 45 days. The evaluation of the process was made through temperature measurements of the piles daily during the test period. On the contrary of the piles with horse manure, the piles with no horse manure didn’t undergo complete maturation in the end of the experiment. Through the results obtained concluded that it was important to use manure horse in yard solid waste composting process to accelerate this process, because the piles without horse manure didn’t reach temperatures that characterize the composting process.

Aplicação de métodos computacionais no estudo das fases intermetálicas ordenadas pt-sn

Fuel cells are a very promising solution to the problems of power generation and emission of pollutant to the environment, excellent to be used in stationary application and mobile application too. The high cost of production of these devices, mainly due to the use of noble metals as anode, is a major obstacle to massive production and deployment of this technology, however the use of intermetallic phases of platinum combined with other metals less noble has been evaluated as electrodes in order to minimize production costs and still being able to significantly improve the catalytic performance of the anode. The study of intermetallic phases, exclusively done by experimental techniques is not complete and demand that other methods need to be applied to a deeper understanding of the behavior geometric properties and the electronic structure of the material, to this end the use of computer simulation methods, which have proved appropriate for a broader understanding of the geometric and electronic properties of the materials involved, so far not so well understood.. The use of computational methods provides answers to explain the behavior of the materials and allows assessing whether the intermetallic may be a good electrode. In this research project was used the Quantum-ESPRESSO package, based on the DFT theory, which provides the self-consistent field calculations with great precision, calculations of the periodic systems interatomic force, and other post-processing calculations that points to a knowledge of the geometric and electronic properties of materials, which may be related to other properties of them, even the electrocatalytic. The electronic structure is determined from the optimized geometric structure of materials by analyzing the density of states (DOS) projected onto atomic orbital, which determines the influence of the electrocatalytic properties of the material... (Complete abstract click electronic access below)

Caracterização de plasmas através da espectrometria de massa

Mass spectrometry is a diagnosis that can aid in the understanding of the kinetics of chemical plasma environment. Through this you can get information about some species present in the environment and make inferences about the behavior of the plasma when parameters such as pressure and applied power changes. When analyzed plasmas generated by the discharge of argon and diglyme (both individually and mixtures of them in various proportions) could be found conditions in which the plasma behavior was different from what is often found in the literature. By the end some peculiar characteristics of plasmas generated by mixing argon / diglyme were raised and it was found that the noble gas is a good mediator of physical and chemical reactions that occur in the environment, and help in the understanding of chemical kinetics. Therefore mass spectrometry was shown highly important tool for the study of plasma environment

Mapeamento geológico, caracterização litoquímica e potencial econômico do corpo de cromitito de Cedrolina, Santa Terezinha de Goiás - GO

Studies of mafic-ultramafic bodies have been carried out through the years due to their great use on the interpretation of geochemical and geotectonic processes that took place in Earth's history. Amongst them, chromitites are notably recognized for being excellent indicators of their parental magma chemistry and of different geotectonic environments, as well for frequently containing associated noble metals mineralization. Thus the investigation of one of this ultramafic bodies that occurs inside the Pilar de Goiás Greenstone Belt was proposed, resulting in a detailed map of the chromitites and country rocks, as well as innumerous new data on the chemistry of chromite and associated matrix and accessory minerals. These studies were based upon geological field observations, optic and Scanning Electron Microscope (SEM), besides electron microprobe and cathodoluminescence analysis performed at the “Eugen F. Stumpfl Laboratory” of the Montanuniversität Institute of Resource Mineralogy, University of Leoben - Leoben, Austria. The chromitites are composed of 40-70% in volume of chromite (~50% on average), 14-55% of talc (~30% on average), 3-60% of chromium rich chlorite (~20% on average), traces to 4% of iron hydroxides and traces to 3% of rutile (1,5% on average). The chromite occurs as large spherical aggregates or as fine grained subhedral crystals disseminated in the matrix. This aggregates have diameters of 0.3-1.5 cm (1 cm on average) and are extremely well rounded, massive to intensively fractured, and commonly deformed to ellipsoids. When observed under the microscope, these aggregates show well rounded to slightly irregular borders, but on their interiors, these structures are represented by fine to medium grained euhedral to subhedral chromite crystals that have sharp contacts between themselves. The rock's matrix is basically made of chlorite and talc that define a metamorphic foliation (Sn), being the talc an alteration product ...

Estudo da atividade antibacteriana in vitro de ativos desodorantes em solução hidroalcoólica

As estruturas da derme como os folículos pilosos e os ductos das glândulas sudoríparas e de óleo, proporcionam uma via de passagem por onde os micro-organismos atingem os tecidos mais profundos da pele. A transpiração fornece umidade e alguns nutrientes para o crescimento microbiano (TORTORA, 2012). Dentre os vários gêneros de bactérias que constituem a microbiota residente das axilas, encontram-se o Staphylococcus e o Micrococcus, responsáveis pelo odor do ácido isovalérico, o odor caracterísitico das axilas. Estão presentes também bactérias do gênero Corynebacterium, responsáveis pelo odor axilar pungente dos esteróides androgênicos (JACKMAN & NOBLE, 1983). O método mais eficaz de inibir a produção de exoenzimas bacterianas responsáveis pelo mau odor axiliar são as composições desodorantes. O método consiste em produzir um veículo cosmético (emulsão, suspensão em gás, composição hidroalcoólica, entre outros) e adicionar um ativo desodorante dissolvido ou em suspensão, que tem como propriedade a inibição da produção das exoenzimas bacterianas que levam à produção dos cheiros desagradáveis. (EIGEN & FROEBE, 1997). Neste trabalho testamos a suscetibilidade de três espécies de bactérias semelhantes às que compõem a microbiota permanente das axilas (Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228 e Corynebacterium xerosis ATCC 373), frente a três formulações cosméticas hidroalcoólicas de desodorantes em spray contendo ativos desodorantes. Utilizamos também a linhagem Escherichia coli ATCC 8739, pois esta enterobactéria pode estar presente nas axilas principalmente pelo contato destas com as mãos (BORICK & SARRA, 1960). A metodologia utilizada para os testes foi baseada na norma M7-A7 (CLSI, 2006), que trata dos testes de sensibilidade a agentes antimicrobianos por diluição para bactérias de crescimento aeróbico. A fórmula desodorante que teve melhor desempenho sobre...

Introdução de Lentinulaedodes (Shiitake) e Pleurotusostreatus (Shimeji) em bagaço de cana termo explodido para diminuição da toxicidade

Ethanol production has gained great prominence in the investment new renewable energy sources and Brazil is among the leaders of production. However, this activity generates large amounts of waste being the largest volume of the sugar cane bagasse. For this reason looking up ways to use this material as burning for energy production and composition of forage in the diet of ruminants, however there are difficulties to use this production for this last one. This paper proposes a microbiological treatment with Lentinula edodes and Pleurotus ostreatus in order to enable the bagasse in ruminant feed composition in order to be used more noble than their burning. After treatment with the fungus, tests were performed for quantifying crude protein by the method of Kjeldhal. It was verified that the protein content in the pure bagasse was 1.0% after fermentation the protein content was 4.2% with L.edodes and 4.9% with P. ostreatus. To evaluate the protein quality of the product fermented by L. edodes and P. ostreatus was applied microbiological method for growth of Enterococcus zimogenes verifying that after fermentation the protein quality was 76 and 27.4% with L. edodes and P.ostreatus, respectively, compared with casein. The quantification of amino acids showed significant improvement of protein with altered amino acid profile with treatments of fungos. About of DQO and BOD were also found considerable improvement besides considerable drop in toxicity as measured by acute toxicity test with Daphinia similis

As crônicas do Inca Garcilaso de La Vega: um discurso de legitimação

A literatura latino-americana está marcada pela heterogeneidade existente na América Latina, e a crônica é considerada o início desta heterogeneidade, devido ao fato de narrar um mundo desconhecido a leitores que fazem parte de outra realidade, gerando assim, uma situação de conflito. Os relatos escritos das civilizações andinas, em sua maioria, são de cronistas espanhóis, no entanto, também nos deparamos com alguns cronistas “índios” e mestiços, como o Inca Garcilaso de la Vega. Ele se destaca não somente por representar esta pequena parcela, ou seja, por ser um mestiço, mas, principalmente por ser herdeiro de duas nobrezas: a nobreza espanhola e a nobreza incaica. O cronista Inca Garcilaso era filho do capitão espanhol Garcilaso de la Vega, que possuía uma família que se destacava na guerra e na literatura; e de Chimpu Ocllo, uma princesa Inca, neta do Imperador Túpac Inca Yupanqui. Porém, este privilégio em relação aos outros mestiços, não lhe garantia o reconhecimento como nobre diante da coroa espanhola. Por isso, veremos neste trabalho que um dos seus intuitos ao escrever as crônicas Comentarios Reales de los Incas e Historia General del Perú, era o de tentar legitimar o seu status social diante dos espanhóis por meio de relatos que descrevem todos os feitos e avanços dos Incas, bem como afirmar, como uma de suas justificativas, que a colonização foi aceita pelos indígenas e estes estavam aptos à catequização, sendo uma maneira do Rei da Espanha e a Igreja Católica “salvarem” este povo da barbárie. Desta maneira, o Inca Garcilaso cria um discurso contraditório, pois, ao mesmo tempo que defende os espanhóis, ele glorifica o Império Inca

Indirect doping of microstructures fabricated by two-photon polymerization with gold nanoparticles

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização de estruturas de óxido de estanho modificado como sensores de gases

Pós-graduação em Química - IQ

Recuperação de turbinas hidráulicas danificadas por erosão cavitacional por soldagem com aço inoxidável/cobalto

Pós-graduação em Engenharia Mecânica - FEIS

Reciclagem de cavacos para a formação de carbonetos de titânio no metal de solda produzido por soldagem GTAW em aço-carbono

Pós-graduação em Engenharia Mecânica - FEIS

Enhanced Mechanical Stability of Gold Nanotips through Carbon Nanocone Encapsulation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characteristics of PbO-BiO1.5-GaO1.5 glasses melted in SnO2 crucibles

PbO-BiO 1.5-GaO 1.5-based glasses are good candidates for optical applications, because of some of their interesting characteristics, such as high refraction indices and high transmission in the ultraviolet (UV), visible (VIS), and infrared (IR) regions. A limited stage in the processing of these glasses is the corrosion that is caused by the melt in all currently used conventional crucibles, such as noble metals (platinum or gold) and Al 2O 3. The absorption of crucible material by the glass composition may reduce the transmission level, the cutoff in the UV-VIS, and IR regions, and the thermal stability. In this study, a SnO 2 crucible has been tested for PbO-BiO 1.5-GaO 1.5 molten glass. Optical and thermal analyses show, in some cases, advantages over the use of platinum and Al 2O 3 crucibles. A visible cutoff value of 474 nm has been measured, and a longer melting time (850°C for 4 h) results in a significant reduction of the O-H absorption band at 3.2 μm.