Estudo dos óxidos A2B2O7 e ABO3 a base de terras raras, para aplicações térmicas e catalíticas a altas temperaturas

Rare earth elements have recently been involved in a range of advanced technologies like microelectronics, membranes for catalytic conversion and applications in gas sensors. In the family of rare earth elements like cerium can play a key role in such industrial applications. However, the high cost of these materials and the control and efficiencies associated processes required for its use in advanced technologies, are a permanent obstacle to its industrial development. In present study was proposed the creation of phases based on rare earth elements that can be used because of its thermal behavior, ionic conduction and catalytic properties. This way were studied two types of structure (ABO3 and A2B2O7), the basis of rare earths, observing their transport properties of ionic and electronic, as well as their catalytic applications in the treatment of methane. For the process of obtaining the first structure, a new synthesis method based on the use of EDTA citrate mixture was used to develop a precursor, which undergone heat treatment at 950 ° C resulted in the development of submicron phase BaCeO3 powders. The catalytic activity of perovskite begins at 450 ° C to achieve complete conversion at 675 ° C, where at this temperature, the catalytic efficiency of the phase is maximum. The evolution of conductivity with temperature for the perovskite phase revealed a series of electrical changes strongly correlated with structural transitions known in the literature. Finally, we can establish a real correlation between the high catalytic activity observed around the temperature of 650 ° C and increasing the oxygen ionic conductivity. For the second structure, showed clearly that it is possible, through chemical processes optimized to separate the rare earth elements and synthesize a pyrochlore phase TR2Ce2O7 particular formula. This "extracted phase" can be obtained directly at low cost, based on complex systems made of natural minerals and tailings, such as monazite. Moreover, this method is applied to matters of "no cost", which is the case of waste, making a preparation method of phases useful for high technology applications

Métodos e estratégias em proteômica e suas aplicações na área vegetal

A implementação da espectrometria de massa (MS) para as análises de peptídeos (MS) e de aminoácidos (MS em tandem ou MS/MS) tornou possível a identificação de centenas de proteínas em experimentos únicos. Uma grande variedade de estratégias está disponível atualmente para o fracionamento e a purificação de amostras, a identificação de proteínas, a quantificação, a análise de modificações pós-traducionais (MPT's) e os estudos de interação. Dessa forma, a proteômica abre novas perspectivas na biologia de plantas com ênfase nos estudos de variabilidade genética, estresses fisiológicos e desenvolvimento de plantas.

Aplicações das atividades estruturadas de Skemp para a construção do conhecimento matemático

The present study constitutes a discussion about the application of Structured Activities to the construction of the mathematical knowledge, proposed by Richard Skemp. The discussion is based on the research that the author carried out in a public school of the state education chain buy using procedures of the research-action. It investigates the possibility of adoption of the proposal of Skemp in a new reality. It utilizes explanations from several theorists to understand the necessity and, at the same time, to enhance the efficiency of the referred activities in first grades of elementary school when students have their first mathematics teachings. It emphasizes the important rule of the teacher, as mediator to the mental constructions of the child. It presents considerations about the results achieved by the research, noticing the possibility of adoption of the studied proposal even though it is necessary an adjustment of the procedures to appropriate didactic-pedagogic requirements to the educational reality in which this project was done

Caracterização química de glucanas fúngicas e suas aplicações biotecnológicas

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

Atividade inseticida das plantas e aplicações: revisão

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

Aplicações da teoria da percolação à modelagem e simulação de reservatórios de petróleo

In this thesis we study some problems related to petroleum reservoirs using methods and concepts of Statistical Physics. The thesis could be divided percolation problem in random multifractal support motivated by its potential application in modelling oil reservoirs. We develped an heterogeneous and anisotropic grid that followin two parts. The first one introduce a study of the percolations a random multifractal distribution of its sites. After, we determine the percolation threshold for this grid, the fractal dimension of the percolating cluster and the critical exponents ß and v. In the second part, we propose an alternative systematic of modelling and simulating oil reservoirs. We introduce a statistical model based in a stochastic formulation do Darcy Law. In this model, the distribution of permeabilities is localy equivalent to the basic model of bond percolation

Filmes nanométricos de FeN e ALN crescidos por sputtering e aplicações do efeito peltier

This study will show the capability of the reactive/nonreactive sputtering (dc/rf) technique at low power for the growth of nanometric thin films from magnetic materials (FeN) and widegap semiconductors (AlN), as well as the technological application of the Peltier effect using commercial modules of bismuth telluride (Bi2Te3). Of great technological interest to the high-density magnetic recording industry, the FeN system represents one of the most important magnetic achievements; however, diversity of the phases formed makes it difficult to control its magnetic properties during production of devices. We investigated the variation in these properties using ferromagnetic resonance, MOKE and atomic force microscopy (AFM), as a function of nitrogen concentration in the reactive gas mixture. Aluminum nitride, a component of widegap semiconductors and of considerable interest to the electronic and optoelectronic industry, was grown on nanometric thin film for the first time, with good structural quality by non-reactive rf sputtering of a pure AlN target at low power (≈ 50W). Another finding in this study is that a long deposition time for this material may lead to film contamination by materials adsorbed into deposition chamber walls. Energy-dispersive X-ray (EDX) analysis shows that the presence of magnetic contaminants from previous depositions results in grown AlN semiconductor films exhibiting magnetoresistance with high resistivity. The Peltier effect applied to commercially available compact refrigeration cells, which are efficient for cooling small volumes, was used to manufacture a technologically innovative refrigerated mini wine cooler, for which a patent was duly registered

Representações espectrais de sistemas complexos: aplicações à síntese de superfícies brownianas fracionárias anisotrópicas, filtragem de sinais e identificação de correlações

In this thesis, we study the application of spectral representations to the solution of problems in seismic exploration, the synthesis of fractal surfaces and the identification of correlations between one-dimensional signals. We apply a new approach, called Wavelet Coherency, to the study of stratigraphic correlation in well log signals, as an attempt to identify layers from the same geological formation, showing that the representation in wavelet space, with introduction of scale domain, can facilitate the process of comparing patterns in geophysical signals. We have introduced a new model for the generation of anisotropic fractional brownian surfaces based on curvelet transform, a new multiscale tool which can be seen as a generalization of the wavelet transform to include the direction component in multidimensional spaces. We have tested our model with a modified version of the Directional Average Method (DAM) to evaluate the anisotropy of fractional brownian surfaces. We also used the directional behavior of the curvelets to attack an important problem in seismic exploration: the atenuation of the ground roll, present in seismograms as a result of surface Rayleigh waves. The techniques employed are effective, leading to sparse representation of the signals, and, consequently, to good resolutions

Aplicações da q-Álgebra em física da matéria condensada

We address the generalization of thermodynamic quantity q-deformed by q-algebra that describes a general algebra for bosons and fermions . The motivation for our study stems from an interest to strengthen our initial ideas, and a possible experimental application. On our journey, we met a generalization of the recently proposed formalism of the q-calculus, which is the application of a generalized sequence described by two parameters deformation positive real independent and q1 and q2, known for Fibonacci oscillators . We apply the wellknown problem of Landau diamagnetism immersed in a space D-dimensional, which still generates good discussions by its nature, and dependence with the number of dimensions D, enables us future extend its application to systems extra-dimensional, such as Modern Cosmology, Particle Physics and String Theory. We compare our results with some experimentally obtained performing major equity. We also use the formalism of the oscillators to Einstein and Debye solid, strengthening the interpretation of the q-deformation acting as a factor of disturbance or impurity in a given system, modifying the properties of the same. Our results show that the insertion of two parameters of disorder, allowed a wider range of adjustment , i.e., enabling change only the desired property, e.g., the thermal conductivity of a same element without the waste essence

Estudo das ligas titânio-zircônio resultantes do processo de fundição plasma-skull para aplicações como biomateriais

The aim of this work was to study a series of 11 different compositions of Ti-Zr binary alloys resistance to aggressive environment, i. e., their ability to keep their surface properties and mass when exposed to them as a way to evaluate their performance as biomaterials. The first stage was devoted to the fabrication of tablets from these alloys by Plasma-Skull casting method using a Discovery Plasma machine from EDG Equipamentos, Brazil. In a second stage, the chemical composition of each produced tablet was verified. In a third stage, the specimen were submitted to: as-cast microstructure analysis via optical and scanning electron microscopy (OM and SEM), x-ray dispersive system (EDS) chemical analysis via SEM, Vickers hardness tests for mechanical evaluation and corrosion resistence tests in a 0.9% NaCl solution to simulate exposition to human saliva monitored by open circuit potential and polarization curves. From the obtained results, it was possible to infer that specimens A1 (94,07 wt% Ti and 5,93% wt% Zr), A4 (77,81 wt % Ti and 22,19 wt % Zr) and A8 (27,83 wt% Ti and 72,17 wt% Zr), presented best performance regarding to corrosion resistance, homogeneity and hardness which are necessary issues for biomaterials to be applied as orthopedic and odontological prosthesis

Obtenção de novos sistemas nanoautoemulsificantes a partir do óleo das sementes de Azadirachta indica A Juss e suas aplicações como inibidores de corrosão

Corrosion is a natural process that causes progressive deterioration of materials, so, reducing the corrosive effects is a major objective of development of scientific studies. In this work, the efficiency of corrosion inhibition on a AISI 1018 carbon steel of the nanoemulsion system containing the oil of the seeds of Azadirachta indica A. Juss (SNEOAI) was evaluated by the techniques of linear polarization resistance (LPR) and weight loss (CPM), a instrumented cell. For that, hydroalcoholic extract of leaves of A. indica (EAI) was solubilized in a nanoemulsion system (SNEOAI) of which O/W system (rich in aqueous phase). This nanoemulsion system (tested in different concentrations) was obtained with oil from the seeds of this plant species (OAI) (oil phase), dodecylammonium chloride (DDAC) (surfactant), butanol (cosurfactant) and water, using 30 % of C/T (cosurfactant/surfactant), 0.5 % of oil phase and 69.5 % of aqueous phase, and characterized by surface tension, rheology and droplet sizes. This systems SNEOAI and SNEOAI-EAI (nanoemulsion containing hydroalcoholic extract - EAI) showed inhibition efficiencies in corrosive environment in saline (1 %), for the method of LPR with significant value of 70.58 % (300 ppm) to SNEOAI, 74.17 % (100 ppm) and 72.51 % (150 ppm) to SNEOAI-EAI. The best efficiencies inhibitions were observed for the method of CPM with 85.41 % for the SNEOAI (300 ppm) and 83.19 % SNEOAI-EAI (500 ppm). The results show that this formulation could be used commercially for use as a corrosion inhibitor, this research contributed to the biotechnological applicability of Azadirachta indica, considering the large use of this plant species rich in limonoids (tetranortriterpenoids), especially azadirachtin

Qualidade fisiológica de sementes e crescimento de plântulas de feijoeiro, em função de aplicações de paraquat em pré-colheita

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

Desenvolvimento formal de aplicações para smartcards

Smart card applications represent a growing market. Usually this kind of application manipulate and store critical information that requires some level of security, such as financial or confidential information. The quality and trustworthiness of smart card software can be improved through a rigorous development process that embraces formal techniques of software engineering. In this work we propose the BSmart method, a specialization of the B formal method dedicated to the development of smart card Java Card applications. The method describes how a Java Card application can be generated from a B refinement process of its formal abstract specification. The development is supported by a set of tools, which automates the generation of some required refinements and the translation to Java Card client (host) and server (applet) applications. With respect to verification, the method development process was formalized and verified in the B method, using the Atelier B tool [Cle12a]. We emphasize that the Java Card application is translated from the last stage of refinement, named implementation. This translation process was specified in ASF+SDF [BKV08], describing the grammar of both languages (SDF) and the code transformations through rewrite rules (ASF). This specification was an important support during the translator development and contributes to the tool documentation. We also emphasize the KitSmart library [Dut06, San12], an essential component of BSmart, containing models of all 93 classes/interfaces of Java Card API 2:2:2, of Java/Java Card data types and machines that can be useful for the specifier, but are not part of the standard Java Card library. In other to validate the method, its tool support and the KitSmart, we developed an electronic passport application following the BSmart method. We believe that the results reached in this work contribute to Java Card development, allowing the generation of complete (client and server components), and less subject to errors, Java Card applications.

BSmart: desenvolvimento rigoroso de aplicações Java Card com base no método formal B

Java Card technology allows the development and execution of small applications embedded in smart cards. A Java Card application is composed of an external card client and of an application in the card that implements the services available to the client by means of an Application Programming Interface (API). Usually, these applications manipulate and store important information, such as cash and confidential data of their owners. Thus, it is necessary to adopt rigor on developing a smart card application to improve its quality and trustworthiness. The use of formal methods on the development of these applications is a way to reach these quality requirements. The B method is one of the many formal methods for system specification. The development in B starts with the functional specification of the system, continues with the application of some optional refinements to the specification and, from the last level of refinement, it is possible to generate code for some programming language. The B formalism has a good tool support and its application to Java Card is adequate since the specification and development of APIs is one of the major applications of B. The BSmart method proposed here aims to promote the rigorous development of Java Card applications up to the generation of its code, based on the refinement of its formal specification described in the B notation. This development is supported by the BSmart tool, that is composed of some programs that automate each stage of the method; and by a library of B modules and Java Card classes that model primitive types, essential Java Card API classes and reusable data structures

Avalição de reusabilidade de aplicações web baseadas em frameworks orientados a ações e a componentes: estudo de Caso sobre os Frameworks Apache Struts e JavaServer Faces

Over the years the use of application frameworks designed for the View and Controller layers of MVC architectural pattern adapted to web applications has become very popular. These frameworks are classified into Actions Oriented and Components Oriented , according to the solution strategy adopted by the tools. The choice of such strategy leads the system architecture design to acquire non-functional characteristics caused by the way the framework influences the developer to implement the system. The components reusability is one of those characteristics and plays a very important role for development activities such as system evolution and maintenance. The work of this dissertation consists to analyze of how the reusability could be influenced by the Web frameworks usage. To accomplish this, small academic management applications were developed using the latest versions of Apache Struts and JavaServer Faces frameworks, the main representatives of Java plataform Web frameworks of. For this assessment was used a software quality model that associates internal attributes, which can be measured objectively, to the characteristics in question. These attributes and metrics defined for the model were based on some work related discussed in the document