Desenvolvimento de um sistema para caracterização de dispositivos eletroluminescentes

The materials designed to be used in electroluminescent (EL) devices construction are studied and improved since 1936. Great interests in the development of this kind of devices are mainly due to its low power consumption, flexibility, low cost and easy processing. One class of ELs devices with these characteristics are produced by employing a organic-polymeric/inorganic composite from a conductive polymer blend and an inorganic electroluminescent material (Zn2SiO4:Mn) dispersed in the polymeric matrix. This kind of device operates in d.c. or a.c. potentials, with EL of hundreds candela in the green region of the visible spectrum. However, few studies on the light emission were performed for these devices. In order to characterize devices made from composites, in this work is proposed a method of characterizing the electroluminescence associated with the impedance spectroscopy technique. To implement the technique of impedance spectroscopy was employ an experimental setup consisting of a source of a.c. voltage, an oscilloscope, and a reference resistor. Associated with this system, was use a photo diode and an analog electrometer to characterize the emitted light signal from the sample. The system was implemented allows characterization by impedance spectroscopy in the frequency range from 0.2 Hz up to 2 MHz and voltage amplitudes of 5 mV up to 20 kV. This system permits, at the same time, measurement of the RMS value of the luminance for devices in frequency range from 20 Hz up to 2 MHz. To test the system efficiency, an EL device was characterized showing analogous results to those reported in literature. By doing this, was demonstrated the efficiency of the system for electroluminescence characterization associated with the electrical characterization by impedance spectroscopy, for devices

Estudo da reutilização de materiais reciclados em obras de construção civil

This graduation project aims to study and analyze the reuse of solid waste projects in Civil Construction, checking the different factors such as economic viability, production processes, classification of the main materials, advantages and disadvantages, always seeking to guide themselves according Brazilian legislation establishing criteria for Waste Management of Construction. In addition, points are studied that prevent the expansion of recycling construction waste. It also offers needs improvements to the implementation of recycling to be carried out on a more expressive than current

Biodegradação de materiais poliméricos por fungos filamentosos

The use of polymeric materials has grown in recent years due to its high durability features, atoxicity, shaping versatility and environment resistance. However, while these features represent good advantages to several industry sectors, it results in one of the most serious environmental problems of contemporary society: the rising accumulation of these material, mainly due to the inadequate disposal of waste. Meanwhile, in order to minimize this problem, some mitigation techniques comes up (arises), among which the use of biodegradable polymers has been gaining attention. Because of their easily action of microorganisms, such material degrade more rapidly, becoming integrated to nature. Furthermore, due to the fact of biodegradation is a natural process, occurring through the action if micro-organisms in the environment itself, it is considered the “cleaner” alternative found so far to plastic components reincorporation in the nature. Among the micro-organisms capable of biodegradation process are the filamentous fungi. These micro-organisms have many advantages over the others, the major one being the capacity to produce a range of enzymes capable of degrading different materials. In this context, the present review made it possible to see the importance of this process as an agent of environmental preservation, suggest the use of blends to minimize the problems of cost and flexibility of biodegradable polymeric materials, as well as noting the lack of studies related to this subject nowadays

Cinética de degradação do sistema resina epóxi/fibra de carbono

With the increasing demand for electricity, the retraining of transmission lines is necessary despite environmental restrictions and crossings in densely populated areas to build new transmission and distribution lines. Solution is reuse the existent cables, replacing the old conductor cables for new cables with higher capacity power transmission, and control of sag installed. The increasing demand for electrical power has increased the electric current on the wires and therefore, it must bear out temperatures of 150°C or more, without the risk of the increasing sag beyond the established limits. In the case of long crossings or densely populated areas, sag is due to high weight of the cable on clearance. The cable type determines the weight, sag, height and the towers dimensions, which are the items that most influence the investment of the transmission line. Hence, to reduce both cost of investment and maintenance of the line, the use of a lighter cable can reduce both number and the height of the towers, with financial return on short and long term. Therefore, in order to increase the amount of transmitted energy and reduce the number of built towers and sag, is recommended in the current work substitute the current core material (steel or aluminium) for alternatives alloys or new materials, in this case a composite, which has low density, elevated stiffness (elasticity module), thus apply the pultruded carbon fiber with epoxy resin as matrix systems and perform the study of the kinetics of degradation by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), according to their respective standards

Avaliação mecânica da colagem estrutural entre compósitos poliméricos e materiais metálicos utilizados em dutos petroquímicos

The development of technology for structural composites has as one of its ends form a set of materials that combine high values of mechanical strength and stiffness and low density. Today, companies like Embraer and PETROBRAS and research institutions like NASA, working with these materials with recognized advantages in terms of weight gain, increased performance and low corrosion. We have developed a systematic study to determine the bond strength between composite carbon fiber / epoxy and fiberglass / epoxy laminate both bonded to a carbon steel which are widely used in the petrochemical industry and repair. For morphological evaluation and bonding between materials of different natures, ultrasound analysis, optical microscopy and stereoscopy were performed. To simulate actual conditions, the composites were subjected to conditioning by using heat shock temperatures from -50 to 80 ° C for 1000 cycles for composite carbon fiber / epoxy composites and 2000 cycles for fiberglass / epoxy . The use of composites studied here proved to be efficient to perform repairs in metallic pipes with application petrochemical, as when exposed to sudden changes of temperature (-50 ° to 80 ° C) cycling at 1000 to 2000 times, its mechanical properties (shear and tensile) practically do not change

A abordagem do voseo em materiais didáticos brasileiros de ensino do espanhol como língua estrangeira

This work discusses the importance of the language varieties in the Spanish language to the process of teaching and learning Spanish as a foreign language (ELE), focusing on the approach, ie, how to deal with the phenomenon voseo in Brazilian textbooks. It presents a brief historical overview on the arising of this language and its implementation in Latin America. From an educational approach that values a good development of communicative competence, it’s driven to a presentation of the Spanish schoolbooks selected by PNLD for the year 2012, as well as an observation of activities that demonstrate the phenomenon called voseo, in other words, the use of the variety of the pronoun vos instead of tú for the treatment of the second person. Given the vast range of Spanish courses as a foreign language for high school students, and the growing interest of young people in learning a second language, this study addresses the importance of developing the communicative competence of a foreign language

O mercado editorial na formação dos professores da educação básica: levantamento e caracterização de revistas pedagógicas (1996-210)

A pesquisa tem por foco o mercado editorial voltado para a formação dos professores da educação básica, com ênfase para as revistas pedagógicas com periodicidade regular em circulação na região Sudeste do país. Objetivou-se reconhecer e caracterizar manifestações desse mercado a partir da análise da materialidade das revistas, buscando encontrar também representações sobre os professores e sua profissão. O trabalho foi realizado sob uma abordagem qualitativa, nos moldes da pesquisa documental. Em um primeiro momento, realizou-se a identificação de quais são as revistas pedagógicas disponíveis no mercado e a que tipo de profissional elas se destinam, partindo de levantamento de materiais presentes em bancas de jornal, livrarias, bibliotecas e também em sites especializados. O segundo momento caracteriza-se pela análise e comparação da materialidade das revistas. Trata-se de um Trabalho de Conclusão de Curso que teve apoio financeiro pelo Programa Institucional de Bolsas de Iniciação Científica da Pró-Reitoria (PROPE) de Pesquisa da UNESP (PIBIC/Reitoria). É parte do projeto “Mercado de formação docente: constituição, funcionamento, possibilidades e limites”, financiado pelo CNPq, que por sua vez integra o Projeto Temático FAPESP “Programas Especiais de Formação de Professores, educação a distância e escolarização: pesquisas sobre novos modelos de formação em serviço

Colheita de energia usando dispositivos baseados em materiais piezoelétrico

Recently, research on energy harvesting has increased substantially. Many researchers have concentrated their efforts to find the best configuration for these systems and to optimize their output power. In the process of energy harvesting, the electric energy is obtained by converting mechanics energy created by an environment vibration source by a transducer, for example, a thin piezoceramic film. That vibration source is, for example, a beam suffering some mechanic force able to generate a vibration in it, an oscillating beam is the best properly used example. Different mechanisms of electromechanical coupling have been developed to harvesting devices, and a particular interest has been given to the use of models that transform the mechanical vibration into electrical current using a piezoelectric element. In this paper we propose a model to energy harvesting from vibrations, from an oscillating beam, including non-linearities in the piezoelectric coupling and a non-ideal excitation in the material. From this model, it was developed a system to obtain some results about the harvested power by the material. It was demonstrated that the power captured was influenced by the effect of the nonlinearities of the piezoelectric coupling, modifying the system dynamic behavior

Estudo de casos de seleção dos materiais e processos para a fabricação de fuselagens

This work proposes a study on the materials selections and processes for the manufacture of aircraft and showing a methodology to reduce the manufacturing cost. The DFMA can be understood as a methodology that aims at reducing manufacturing and assembly costs and coupled with the increase of product quality through design simplifications. The most commonly material used in the manufacture of aircraft is aluminum alloys due to these possess great structural strength, good elasticity, and being stainless having a low specific weight (about 1/3 that of steel), reducing the weight of the aircraft. A case study in which an operation in the process of verifying the quality was generating unnecessary costs time / man for the company was also developed. The problem solution was simple, just removing the attachment process. It was found that the DFMA methodology is extremely important for the simplification of processes and projects, contributing to the reduction of manufacturing costs of aircraft

Intervenção urbana: transporte público e qualidade de vida na cidade sem limites - terminal urbano central de Bauru

O grau de desenvolvimento econômico e social de uma sociedade pode ser avaliado diretamente à facilidade de transporte de passageiros e cargas. A qualidade de vida nas cidades é fortemente influenciada pelas características do transporte público. O Brasil tem 80 % de sua população morando em cidades, de forma que uma maior utilização do transporte público seria a solução para problemas de congestionamento, poluição, acidentes, desumanização e outros males que atingem as cidades modernas. Bauru, interior de São Paulo, é uma cidade de porte médio que apresenta um dos maiores índices de utilização de automóveis particulares, em parte pela formação da cidade, que é “espalhada”, e outra por suas características econômicas. A população de baixa renda, moradores da periferia e dependentes do transporte público, enfrenta grandes dificuldades para acessar as diferentes áreas da cidade (má operacionalização do sistema?). Este trabalho de finalização da graduação tem como objetivo maior trazer opções e facilitar o acesso da população a todas as áreas da cidade, através de um sistema de terminais e mini-terminais urbanos de transporte coletivo, buscando a melhor utilização do espaço público, uma maior mobilidade na cidade e a melhoria da qualidade de vida da população

Aspectos formais da trilha musical de Yasunori Mitsuda para o game Chrono Cross e sua interação com o enredo

This work has the aim of evince compositional tools used in the development of musical scores for role-playing videogames through the analysis of Yasunori Mitsuda’s music for Chrono Cross (1999). This research is divided in two main parts: the first traces a historic path of the RPG genre on videogame consoles, since its birth as a tabletop game in the decade of 1970 until its consolidation on 3D game machines released in the 1990’s. The focus of this historical study concentrates on the aesthetics of this kind of game and on the multiple relations it settles with sound throughout the years. The second part is an analytical work on an assortment of pieces by Mitsuda for the aforementioned game, bringing up the most interesting aspects of the connections established between these compositions and the whole game.

Estudo das propriedades físicas em materiais vítreos do sistema 50B2O3 - 15CuO - 20Li2O - 15X (X= Na2O, K2O, RbCI e Cs2O)

The increasing demand for devices for solid state applications in many technological areas has resulted in a high demand for new materials. Among these material have the advantage of being manufactured with different chemical compositions, and may have physical properties equal to or higher than the corresponding crystalline material. The aim of this paper was to produce borate glass system 50B2O3 – 15CuO – 20Li2O – 15X (X = Na2O, K2O, RbCl e Cs2O) to analyze the influence of the atomic radius of alkali in the physical properties of this glass system. The glasses were synthesized by the process of melting and molding. The characteristic temperatures were determined by the technique of scanning calorimetry (DSC). The non-crystalline was determined by x-ray diffraction. In order to determine the molar volume a density measurement by using the Archimedes method was used. The structural characterization was carried out using the technique of infrared spectroscopy

Estudo teórico da contribuição do espalhamento nuclear não elástico na trajetória de prótons de energias entre 50 e 250 MeV em materiais de interesse em radiologia: aplicação em tomografia com prótons

The goal of this work is to study the process of interaction of protons with matter through Monte Carlo simulation. For this purpose, it was employed the SRIM program (Stopping and Range of Ions in Matter ) and MCNPX (Monte Carlo N-Particle eXtended) v2.50. This work is going to support the development of a tomography system with protons. It was studied the interaction of proton with the follow materials: Polimethyl Mehacralate (PMMA), MS20 Tissue Substitute and water. This work employed energies in range of 50 MeV and 250 MeV, that is the range of clinical interest. The energy loss of proton after cross a material layer, the decreasing of its intensity, the angular and lateral de ection of incident beam, including and excluding nuclear interactions. This work is related with Medical Physics and Material Physics, like interaction of radiation with matter, particle transport phenomena, and the experimental methods in Nuclear Physics like simulation and computational by Monte Carlo method

Física de partículas no ensino médio: uma análise de materiais para apoio didático

This work consisted in analysing five materials which mean respect to subjects related to Particle Physics, aiming to explore their potentialities for the use in the High School levels, particularly by physics teachers. On this perspective, we sought to describe the contents of each material and point out their potentialities as material of didactic support. They are: 1. The purpose of Secretaria da Educação do Estado de São Paulo, presented in the Teacher's Guide of the Program São Paulo faz escola; 2. The Game Sprace Game, elaborated by the European Organization for Nuclear Research (CERN); 3. The book O discreto charme das partículas elementares, written by the professor Maria Cristina Abdalla; 4. The video O discreto charme das partículas elementares, based on the book of Professor Maria Cristina Abdalla which was produced by TV Cultura in association with the Ministério da Educação e Cultura” (MEC). The book Partículas elementares no ensino médio: uma abordagem a partir do LHC written by Wagner Franklin Balthazar and Alexandre Lopes de Oliveira, from the collection CBPF - Tópicos de Física. The work was constructed on a qualitative perspective, that is, it did not attempt to quantify the help that each material could offer to Physics teaching. One sought to describe and analyse, from different theoretical frames, their potentialities for the use in the High School level. The results indicate that all the materials analysed can contribute to the Physics teaching, and beyond, as they own format and approches distinct from the subject, they can be used as a whole or in parts, together or separately, depending on the objectives to be reached and on the profile of the target public

Desafios ambientais na indústria automobiliística: uma análise do processo de reciclagem e reutilização de materiais

This research has as main objective the analysis of the auto industry has done to reduce disposal of solid waste in its production process as much as to facilitate the recycling of cars after they complete their life cycle. Despite the auto industry is not one of the most polluting in terms of its production process, it produces a good that is causing major pollution. In despite of the great current concern in seeking to reduce the emissions of pollutants by vehicles, as important as the quest for cleaner fuels is the study of how to dispose of old cars. Even if the car production does not increase significantly each year in relative terms, we must consider the fleet of used cars that still circulates in the world. Ending the mammoth “cemeteries” of automobiles, however, it is not so easy, even because the car is composed of various materials, which in many cases are not easily separable. In addition to an overview, the research seeks to examine the possible advances in Brazil related to the process of auto recycling