Modificação de membranas de quitosana por plasma para uso biológico

Chitosan membranes have been modified by plasma, utilizing the following gases: nitrogen (N2), methane (CH4), argon (Ar), oxygen (O2) and hydrogen. The modified membranes by plasma were compared to the unmodified ones. The membranes were characterized by absorption assay, contact angle, atomic force microscopy (AFM). Also, permeability assay of sodium sulfamerazine from such membranes were carried out. Through the absorption assay and contact angle it was possible to obtain information of the wettability of the membranes and what changes the plasma treatment can promote in relation to it. The plasma treatment using oxygen promoted increase of the wetability and swelling while the samples treated with methane decrease of the wetability and swelling. Through the Optical Emission Spectroscopy (OES) it was possible to identify which species were present in the plasma during the treatment. And through the AFM analysis it was possible to observe the changes nanotopography occurred on the surface of the samples. Permeability assay were archived for all treated membranes and compared to no treated ones. Due to that assay it was possible verify which the plasma treatment increased the permeability spectrum of the membranes which has varied from 1,4548 *10-5cm2.min-1 to 2,7713*10-5cm2.min-1. Chitosan membranes with permeability varied are importance in systems drug delivery, to liberate a wide variety of drugs

Desenvolvimento de tubulação em compósito polimérico revestida externamente com poliuretano de alta densidade

Pipelines for the transport of crude oil from the production wells to the collecting stations are named production lines . These pipes are subjected to chemical and electrochemical corrosion according to the environment and the type of petroleum transported. Some of these lines, depending upon the composition of the fluid produced, may leak within less than one year of operation due to internal corrosion. This work aims at the development of composite pipes with an external protecting layer of high density polyurethane for use in production lines of onshore oil wells, meeting operational requirements. The pipes were manufactured using glass fibers, epoxy resin, polyester resin, quartz sand and high density polyurethane. The pipes were produced by filament winding with the deposition of high density polyurethane on the external surface and threaded ends (API 15 HR/PM-VII). Three types of pipes were manufactured: glass/epoxy, glass/epoxy with an external polyurethane layer and glass/epoxy with an intermediate layer of glass fiber, polyester, sand and with an external polyurethane layer. The three samples were characterized by Scanning Electronic Microscopy (SEM) and for the determination of constituent content. In addition, the following tests were conducted: hydrostatic test, instant rupture, shorttime failure pressure, Gardner impact, transverse stiffness and axial tension. Field tests were conducted in Mossoró RN (BRAZIL), where 1,677 meters of piping were used. The tests results of the three types of pipes were compared in two events: after two months from manufacturing of the samples and after nine months of field application. The results indicate that the glass/epoxy pipes with an intermediate layer of fiber glass composite, polyester e sand and with an external layer of high density polyurethane showed superior properties as compared to the other two and met the requirements of pressure class, axial tensile strength, transverse stiffness, impact and environmental conditions, for onshore applications as production lines

Estudo sobre o efeito dos parâmetros de processamento dos pós e sinterização do aço inox 316l reforçado com NbC

This masther dissertation presents a contribution to the study of 316L stainless steel sintering aiming to study their behavior in the milling process and the effect of isotherm temperature on the microstructure and mechanical properties. The 316L stainless steel is a widely used alloy for their high corrosion resistance property. However its application is limited by the low wear resistance consequence of its low hardness. In previous work we analyzed the effect of sintering additives as NbC and TaC. This study aims at deepening the understanding of sintering, analyzing the effect of grinding on particle size and microstructure and the effect of heating rate and soaking time on the sintered microstructure and on their microhardness. Were milled 316L powders with NbC at 1, 5 and 24 hours respectively. Particulates were characterized by SEM and . Cylindrical samples height and diameter of 5.0 mm were compacted at 700 MPa. The sintering conditions were: heating rate 5, 10 and 15◦C/min, temperature 1000, 1100, 1200, 1290 and 1300◦C, and soaking times of 30 and 60min. The cooling rate was maintained at 25◦C/min. All samples were sintered in a vacuum furnace. The sintered microstructure were characterized by optical and electron microscopy as well as density and microhardness. It was observed that the milling process has an influence on sintering, as well as temperature. The major effect was caused by firing temperature, followed by the grinding and heating rate. In this case, the highest rates correspond to higher sintering.

Concreto celular polimérico: influência na adição de resíduo de poliéster insaturado termofixo

This work addresses the production of lightweight concrete building elements, such as plates, prefabricated slabs for pre-molded and panels of fencing, presenting a singular concrete: the Lightweight Concrete, with special properties such low density and good strength, by means of the joint use of industrial waste of thermosetting unsaturated polyesters and biodegradable foaming agent, named Polymeric Lightweight Concrete. This study covered various features of the materials used in the composition of the Polymeric Lightweight Concrete, using a planning of factorial design 23, aiming at studying of the strength, production, dosage processes, characterization of mechanical properties and microstructural analysis of the transition zone between the light artificial aggregate and the matrix of cement. The results of the mechanical strength tests were analyzed using a computational statistics tool (Statistica software) to understand the behavior and obtain the ideal quantity of each material used in the formula of the Polymeric Lightweight Concrete. The definition of the ideal formula has the purpose of obtaining a material with the lowest possible dry density and resistance to compression in accordance with NBR 12.646/92 (≥ 2.5 MPa after 28 days). In the microstructural characterization by scanning electron microscopy it was observed an influence of the materials in the process of cement hydration, showing good interaction between the wrinkled face of the residue of unsaturated polyesters thermosetting and putty and, consequently, the final strength. The attaining of an ideal formula, given the Brazilian standards, the experimental results obtained in the characterization and comparison of these results with conventional materials, confirmed that the developed Polymeric Lightweight Concrete is suitable for the production of building elements that are advantageous for construction

Síntese, estudo cinético e análise microestrutural do sistema cério-níquel obtido pelo método pechini

The cerium oxide has a high potential for use in removing pollutants after combustion, removal of organic matter in waste water and the fuel-cell technology. The nickel oxide is an attractive material due to its excellent chemical stability and their optical properties, electrical and magnetic. In this work, CeO2-NiO- systems on molars reasons 1:1(I), 1:2(II) e 1:3(III) metal-citric acid were synthesized using the Pechini method. We used techniques of TG / DTG and ATD to monitor the degradation process of organic matter to the formation of the oxide. By thermogravimetric analysis and applying the dynamic method proposed by Coats-Redfern, it was possible to study the reactions of thermal decomposition in order to propose the possible mechanism by which the reaction takes place, as well as the determination of kinetic parameters as activation energy, Ea, pre-exponential factor and parameters of activation. It was observed that both variables exert a significant influence on the formation of complex polymeric precursor. The model that best fitted the experimental data in the dynamic mode was R3, which consists of nuclear growth, which formed the nuclei grow to a continuous reaction interface, it proposes a spherical symmetry (order 2 / 3). The values of enthalpy of activation of the system showed that the reaction in the state of transition is exothermic. The variables of composition, together with the variable temperature of calcination were studied by different techniques such as XRD, IV and SEM. Also a study was conducted microstructure by the Rietveld method, the calculation routine was developed to run the package program FullProf Suite, and analyzed by pseudo-Voigt function. It was found that the molar ratio of variable metal-citric acid in the system CeO2-NiO (I), (II), (III) has strong influence on the microstructural properties, size of crystallites and microstrain network, and can be used to control these properties

Estudo da adição de resíduo de scheelita em matriz cerâmica: formulação, propriedades físicas e microestrutura

Extractivism mineral is considered an activity highly degrading, due to the large volume of material that he moves in the form of ore and residues. The vast majority of mining companies do not show any technology or economically viable application that will allow the recycling of mineral residue, these being launched in areas receiving located the "open skies" degrade the environment. In Rio Grande do Norte to the production of ceramic red restricts their activities to the production of products such as: solid bricks, ceramic blocks, tiles, among others. Seeking to unite experiences and technical information that favor sustainable development, with important benefits to the construction sector and civil society in general, the present work studies the incorporation of the residue of scheelite in ceramic matrix kaolinitic, coming from the municipality of Boa Saúde - RN, in percentage of 5 %, 10 %, 20 %, 30% 40% and 50 %, by evaluating its microstructure, physical properties and formulation. The raw materials were characterized through the trials of X ray fluorescence, Diffraction of X rays, Differential Thermal Analysis and Termogravimetric Analysis. The samples were formed and fired at temperatures of 850o, 900o, 1000o, 1050o, 1100o, 1150o and 1200 oC, with isotherm of 1 hour and heating rate of 10 oC/min. Assays were performed technological of loss to fire, Water Absorption, Apparent Porosity, Apparent Density, Mass Loss in Fire and Bending Resistance; in addition to the Scanning Electron Microscopy, analyzing their physical and mechanical properties. The use of residue of scheelite in ceramic mass kaolinitic provided a final product with technological properties that meet the technical standards for the production of bricks and roofing tiles, with the percentage of 20% of waste that showed the best results

Avaliação de concreto com adição de fibras de PET submetido a altas temperaturas

The concrete for centuries constituted an essential structural element in the construction industry due to its relative ease of forming, before the weather durability, low cost, its lower maintenance compared to other materials such as steel. However, when the concrete is exposed to high temperatures tends to lose its mechanical characteristics, and may even result in loss of section, which undermines the stability and mechanical strength of structural elements. The pathologies resulting from exposure to elevated temperatures ranging from cracks, pops up chipping explosives (spalling). Recently, the technology of concrete is closely related to the study of its microstructure. The use of fibers added to concrete has been revealed as a solution to increase the mechanical strength of the concrete, it acts directly on the distribution of efforts to act in the play within the microstructure. In this work we used recycled PET fibers embedded in concrete with 15x2mm fck = 30MPa, water/cement ratio of 0.46, in works made for verification of mechanical strength of this mixture submitted to high temperature. The specimens of concrete with addition of PET fibers were tested after exposure to temperatures: ambient (30ºC), 100°C, 200°C, 300°C, 400°C, 600°C and 900°C. It was found that the concrete loses significant strength when exposed to temperatures above 300°C, however the use of fiber PET may delay the risk of collapse of structures for the formation of a network of channels that facilitate the escape of vapor 'water, reducing the pore pressure inside the structural element

Balanced Scorecard: fatores relevantes de sua implantação na diretoria de mercado de capitais do Banco do Brasil

Este trabalho objetiva determinar que características do corpo funcional da DIMEC (Diretoria de Mercado de Capitais do Banco do Brasil) estão associadas aos principais entraves considerados relevantes pelos funcionários da área durante a implementação do Balanced Scorecard (BSC). Pretende-se salientar como entraves tais como a falta de apoio de Tecnologia de Informação e a falta de hábito dos funcionários em lidar com indicadores não financeiros podem se relacionar com as características de interesse do corpo funcional, tais como nível hierárquico , formação acadêmica e nível de conhecimento da ferramenta BSC , de forma a influenciar na implementação do modelo. Para tanto foi realizada revisão de literatura e estudo de caso no qual figuraram, como instrumentos de coleta de dados, a aplicação de questionários e a entrevista não-estruturada através dos quais funcionários da DIMEC demonstraram as relações entre as variáveis descritas de forma a destacar fatores de relevância para o desenrolar do processo de implantação da ferramenta BSC na referida empresa

Adoção de tecnologias móveis em empresas do Rio Grande do Norte, Pernambuco e Ceará

One of the best examples of the Information and Communication Technology (ICT) evolutions is on the high capability of storing and processing data into smaller devices, creating a new business condition, the mobility . This mobility in a deeper analysis proposes a business remodeling in many different areas (business segmentations), through the Internet anywhere at any time, allowing managers and researchers to think again their actual models that work nowadays in companies and public institutions, modifying the way internal and external clients can be attended. This thesis analyzes issues on mobile business adoption, technological evolutions and the impacts caused by this new reality the access to information anywhere at any time . This research is exploratory and shows a compilation of similar papers and thesis describing how was conducted the survey within 50 companies in the states of Rio Grande do Norte, Pernambuco and Ceará. The statistics analysis showed the different level of mobile technology usage from simple voice communications to wide band data transmission. The analysis pointed that canonic correlation was the most effective type of analysis to describe the relations among all groups of variables showing which of them are relevant, or not, for mobile technology adoption

Análise antropotecnológica do desenvolvimento de novos produtos na produção artesanal : caso das rendeiras de bilro da Vila de Ponta Negra em Natal, RN

Brazilian craft production plays an important role in the generation of employment and income for many families in every state across Brazil. In Natal, Rio Grande do Norte, Brazil, among many types found, identifies itself with the production of bobbin-lace, still practiced in Ponta Negra Village for ancient craftswomens of city that try to preserve the art and tradition of bobbin-lace. This work presents the results of an analysis conducted based in concepts of anthropotechnology, on the effects of a design workshop held with bobbin-lace craftswomen in the village of Ponta Negra in July of 2006. The workshop was intended to propose a new concept of products and a new alternative for production in the activity of the craftswomen, on the premise that the laces could be used as a detail inserted into other industrial products such as shirts, bags, towels, etc. Evaluations after the workshop showed that none of the artisans continued to work, indicating that actions focused solely on products did not generate representative results in the production of bobbin-lace. Evaluations also indicated that knowledge about the artisan's personal and professional characteristics, organization, pace, workload, and cultural and historical issues that permeate the activity are essential to the success of technology transfer, particularly when the transfer affects the craft production as it relates to the inseparable aspects of the craftswomen's work and lifestyle

Utilização de soluções business-to-business (B2B) no segmento downstream da cadeia de suprimentos de uma distribuidora de combustíveis

The pursuit of competitive advantage is lobbying organizations to strategically plan the use of their material, human, technological and financial resources, so that it s possible to add value to the product, even when it is considered a commodity. The scenario for this planning should not be limited to the company in question, but cover an entire supply chain, which is composed of several organizations which have common goals of growth and sustainability of the market. They should form trade links, integrating the chains of individual values, in a perspective of value system. In this supply chain there is a flow of services, payments and information, as products well as. The training of these links can be supported by the adoption of a set of information technology, here called solutions business-to-business (B2B), which will be responsible for the production, storage and distribution of relevant information to business transactions between the companies involved. On this view, this thesis aims to describe the B2B solutions adopted in the downstream segment of the supply chain of a distributor of fuel and the nature of these technologies as well as their impact on the creation of value for business and optimization of the relationship between companies. This is a case study on a national distributor of fuels, from a model of research produced under the influence of theories of integrated logistics system and value of Michael Porter. The analyses came to the conclusion that information technology is perceived as an essential tool to the operation of all activities carried out by the company. Among them, at was also brought the key activities of integrated logistics: administration of applications, inventory management, management transport and customer services, which were highlighted in this study. It was also noticed that even these activities are, in principle, purely operational; they all had in the adoption of strategies for leadership in cost or differentiation, supported by B2B solutions identified, making it more conducive to business and direct customer, the clinic reseller of fuel, to obtain value and benefits of this market segment as competitive

Desenvolvimento de protótipo de cadeira de banho para indivíduos com paralisia cerebral tetraparética espástica

This study proposes to develop an equipment that attends the demands of tetraplegic people due to cerebral palsy and that promotes an adequate caregivers postural biomechanics during the shower activity of daily living. First, a bibliographic review was performed to define the terms refering to cerebral palsy, activity of daily living (specifically shower), and assistive technology, besides listing the wheelchairs made on the mainly national assistive technology companies. Therefore, this is a descriptive-exploratory study based on a literature review and on a based-field exploration research. On the field research a survey was adopted as a methodological procedure as it is related to a direct investigation related to a phenomenon, on the case, represented by the current shower situation of the people investigated in this study. Data were collected with the application of a form to the caregivers and consumers of the medical-therapeutic treatment and place used by the participants. Such form, which was made up of open and close questions, tried to identify, besides the personal data of evaluated users and consumers, the characteristics of the current shower activity, such as the place where it takes place in the house, the used equipmentS, in the case there is any, and how often it occurs. The form also was used to identify the caregivers and consumers desires and perceptions in relation to the present characteristics of the new dispositive besides the users and consumers anthropometric data. The evaluation of the results obtained through the form, together with the practice and clinical experience of the researchers and engineers involved in this study, made it possible to develop and make up a real shower chair prototype with the specific adjusts destined to adequate the equipment to be used according to the needs of each user and consumer

Um estudo da aplicação do conceito de risco na conscientização e conhecimento de estudantes de ensino técnico sobre riscos de segurança e saúde ocupacional em laboratório de soldagem

This dissertation presents a discussion on the level of risk awareness of students who have welding practice in the laboratories at CEFET/PI, both in Teresina and Floriano. Its main goal is to investigate risk factors involving students, teachers and employees that work in these laboratories. It s an empirical survey, held among a certain amount of students from the course in Mechanic Technology. For data analysis, the concept of risk was compared to the students direct measure of perception. The main results suggest the students must be better informed, more risk aware and more competent, in order to avoid accidents. They also point to a strong need for a more formal and effective performance to assure full consciousness about the risks involving the welding practice.

Gestão do Conhecimento e o uso estratégico de Tecnologias de Informação: um estudo em Redes de Franquias no Estado do Rio Grande do Norte

This study discusses the use of information technologies for knowledge management in networks of franchises in the Rio Grande do Norte/Brazil, whose management and operation are complex activities, characterized by the geographic spread of their network unities, creating barriers to communication and information sharing between franchisors, franchisees and final customers. In view of this, the following hypotheses were formulated: the knowledge management can be a positive alternative for improving communication between units; and information technology can eliminate many problems related mainly to capture and share knowledge. In general, it aims to investigate, in qualitative and quantitative aspects, how information technology can support knowledge management in networks of franchises. Specifically purposes to register the existence of managerial practices related to knowledge management in enterprises at the franchising sector; to verify whether they have the technological resources with the potential to facilitate the sharing of information; to identify what are the technologies of information and communication used in the organizational environment; and suggest measures that will facilitate the process of organizational learning, using information technology and communication as tools. It concludes that knowledge management becomes a positive alternative, especially in strengthening of bonds of communication and sharing of knowledge between the franchises. In this regard, information technology must provide all the services of the corporation to facilitate communication between franchisor and franchisee, through a single and integrated system. However, they still show unsuitable for more sophisticated technology platforms

Diagnóstico e avaliação das áreas de destino final dos resíduos sólidos urbanos no estado do rio grande do norte

This work aims to present the diagnosis and the evaluation of areas of final destination of urban solid waste in Rio Grande do Norte (RN) state. The survey was based on the experience of the State of São Paulo, which made its first inventory in 1997, through its Companhia de Tecnologia de Saneamento Ambiental CETESB. The methodology for the structuring of diagnosis was the Índice de Qualidade de Aterros de Resíduo -- IQR, developed by the Institute for Technological Research of São Paulo (ITRP). The calculation is based on the completion of a matrix that contains information about the main features of the site, infrastructure and operating conditions of the area of waste disposal. This study intends to subsidize the state government of Rio Grande do Norte through its State Secretariat of Environment and Water Resources and the Instituto de Desenvolvimento Sustentável e Meio Ambiente do RN (IDEMA), as well as federal, state and municipal authorities, in the definition of public policies for integrated management of municipal solid wastes to take account of environmental preservation and improvement of sanitary conditions of Natal-RN population.