Extensometria: estudo das microdeformações ao redor de três implantes de hexágono interno, com posicionamento linear, sob a influência da fundição de coifas plásticas e usinadas

The objective of this in vitro study was quantify the micro strain development around the internal hexagon implants, varying the type of prosthetic coping. For This reason, three implants of internal hexagon were inserted into one polyurethane block in line placement. Microunit abutments were screwed onto the implants. Tangentially the implants were bonded the strain gauges, two to the center implant. Ten structures, each one containing three copings were cast in Co-Cr alloy, that were divided into groups in the first group, plastic copings were used, and in the second group machined copings were used. The superstructure’s occlusal screws were tightened onto Microunit abutments with 10 Ncm torque, the magnitude of micro strain was recorded. The mean values of each strain gauge of each plastic copings were 363,37 ± 237,66 and the machined copings were 338,12 ± 223,01. The data were analyzed statistically by t- Student test. No statistically significant difference was found between the prosthetic copings (p= 0,867). It was concluded that to internal hexagon implants in line placement, the type of copings presented similar magnitude of micro strain after prosthetic occlusal screw was tightened

Modificação superficial de nanopartículas de óxido de ferro por poli(ácido aspártico) reticulado

Pós-graduação em Química - IQ

Degradação dos fármacos ciprofloxacino e sertalina pelos processos ferro zero e foto-Fenton - aplicação em amostras de efluentes de estação de tratamento de esgoto

Pós-graduação em Química - IQ

Modificação de nanopartículas de óxido de ferro por dextranas

A modificação de nanopartículas de óxido de ferro tem sido motivo de diversos estudos devido ao grande potencial em aplicações tecnológicas, em especial a área biomédica, pela aliança das propriedades magnéticas dos óxidos com a funcionalidade que a dextrana confere a esse material. O presente trabalho tem como objetivo sintetizar e caracterizar o sistema óxido de ferro/dextranas. O óxido de ferro foi obtido pela reação de co-precipitação de sais de ferro (II) e ferro (III) - na razão molar 1:2 - com hidróxido de sódio e a modificação das partículas magnéticas se deu por dois métodos: (I) a co-precipitação na presença de dextrana e carboximetil dextrana e (II) a co-precipitação seguida da modificação. Para modificação proposta pelo método (II) se fez necessário enxertar a dextrana em ácido acrílico, utilizando o íon Ce(IV) como iniciador da reação de polimerização. Nessa etapa se averiguou a concentração de iniciador ótima para a síntese e, através da técnica de espectroscopia de infravermelho, se pode confirmar a eficiência do enxerto. A concentração 0,3% de íon Ce(IV) apresentou melhor distribuição de tamanho, obtidos por análises de microscopia eletrônica de varredura e espalhamento de luz dinâmico, sendo escolhida para síntese junto a partícula magnética. A difratometria de raio X permitiu determinar a formação de estrutura cristalina da magnetita e maghemita, que são muito parecidas entre si, porém os espectros de infravermelho apontaram desdobramentos da ligação Fe - O característica da maghemita. A relação Fe2+/ Fe3+ obtida por espectrofotometria também resultou em oxidação. A estabilidade coloidal dos sistemas foi avaliada através de medidas de potencial zeta. A modificação da partícula magnética com carboximetil dextrana foi equivalente para os dois métodos empregados, entretanto a modificação com ...

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 ....

Prospecção mineral de alvos potenciais à ocorrência de enriquecimento supergênico de níquel no Greenstone belt do Morro do Ferro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxidação e remoção de ferro e manganês em águas para fins de abastecimento público ou industrial: uma abordagem geral

The iron and manganese ions are present in a high frequency in water source in Brazil. Despite of the frequency in which such problems occur, the way the problem is faced is still traditional, i.e. focusing on oxidative process instead of solid-liquid separation. The treatment can be very simple, in groundwater, or very complex, when metals are present together with organic matter in water. This article presents a review of principal works besides some important aspects about iron and manganese in natural water, occurrence, forms in natural water, organic complexes, oxidation and removal applying solid/liquid separation processes. Further, a new strategy for iron and manganese removal is presented. The information described does not exhaust the matter, so a large bibliography was cited at the end of the article.

O uso das novas tecnologias informacionais no acervo do patrimônio industrial ferroviário: o caso da estrada de ferro noroeste do brasil de bauru

This paper addresses the issue of access the industrial heritagerailway information integrating the EFNOB in the city of Bauru / SP, through the use of new technologiesinformation. For constitute a major challenge in gathering, organizing, scanning and providing such documentary collection, the research aims to organize and disseminate information document, supported by new access technologies, aiming to preserve and create conditions for setting up a database of documents and cartographic this collection. This research is part of our project entitled "EFNOB Bauru: Center for Memory and Virtual Information", which in turn is part of the larger project, called "EFNOB / Bauru, Km 0," FAPESP / CONDEPHAAT. One of the cornerstones of the work is to collect, treat, select and the heritagedisseminate of movable and immovable EFNOB through the creation of a MemoryCentre and Industrial HeritageRailwayInformation of EFNOB.

Dissolução redutiva de minério de ferro por Acidithiobacillus ferrooxidans para a recuperação de metais de interesse econômico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise morfológica do cérebro de abelhas sem ferrão Melipona Scutellarias expostas ao Tiametoxam

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização da função Desirability em um processo de fundição de aço ABNT 1030

This dissertation addresses the main theme the use of desirability tool in optimizing a process with multiple response variables. The current scenario of strong bids to conquer the consumer market makes it necessary to develop improvements for better process performance as a whole, is to cut costs, increase efficiency or effectiveness. Thus, the use of methods to assist in this process is becoming increasingly feasible. This study used the MINITAB program and the data of the doctoral thesis of Dr. Luiz Henrique Dias Alves, in order to compare the results obtained in both studies. As a result, after applying the desirability method, simulated to optimize two responses variables regarding the formation of voids related to solidification in ABNT 1030 steel casting process. Thus, it was possible to evaluate the behavior of the variables with the variation of parameters of the desirability function

Estudo da utilização de ferramentas a base de nitreto de silício (Si3N4) e alumina (Al2O3) na usinagem do ferro fundido vermicular

Machining is one of the most commonly manufacturing processes used in the modern world, consuming millions of dollars annually. Because of this, it is crucial for the automotive industry to reduce costs on their heat-resistant alloy machining processes, such as compacted graphite iron (CGI), which has shown an increasing trend of its application in diesel engine blocks, brakes disks, among other applications, due to its superior mechanical properties to gray cast iron. Despite this advantage, its use is still limited due to its difficulty of machining, moreover, cutting tools are displayed as the main factor in increasing the machining cost. Seeking an alternative to a better machinability of CGI, this paper aims to study two types of ceramic tools developed in Brazil, and benchmark their performance by dry turning. For this, were used CGI class 450 and two tools: ceramic of silicon nitride (Si3N4) and alumina-based (Al2O3), with a cutting speed (Vc) of 300, 400 and 500 m / min; feed (f) of 0.2 mm / rev and depth of cut (ap) of 0.5 mm, using three replicates and starting with new cutting edges. The results showed that the Al2O3 tool had the best performance in Vc of 500 m / min, while the Si3N4 tool had the best results in Vc of 300 m / min. This can be explained by the tool of Si3N4 based include soft intergranular phase, called amorphous, while alumina has higher abrasion resistance due to its high refractoriness. The results make it clear that the tools have significant potential for machining of compacted graphite iron, being necessary a strict control of the cutting parameters used

Modificação da superfície de óxidos de ferro por dextrana derivatizada para aplicações em liberação de fármaco

Pós-graduação em Química - IQ

Análise morfológica do cérebro de abelhas sem ferrão Melipona Scutellarias expostas ao Tiametoxam

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização da função Desirability em um processo de fundição de aço ABNT 1030

This dissertation addresses the main theme the use of desirability tool in optimizing a process with multiple response variables. The current scenario of strong bids to conquer the consumer market makes it necessary to develop improvements for better process performance as a whole, is to cut costs, increase efficiency or effectiveness. Thus, the use of methods to assist in this process is becoming increasingly feasible. This study used the MINITAB program and the data of the doctoral thesis of Dr. Luiz Henrique Dias Alves, in order to compare the results obtained in both studies. As a result, after applying the desirability method, simulated to optimize two responses variables regarding the formation of voids related to solidification in ABNT 1030 steel casting process. Thus, it was possible to evaluate the behavior of the variables with the variation of parameters of the desirability function