De nos jours, l’industrie aérospatiale est composée d’acteurs internationaux.Due à la complexité de leur production (taille, nombre de composants,variété des systèmes, ...), la conception d’un avion ou d’un lanceurnécessite un grand nombre d’ingénieurs avec des domaines d’expertises variés.De plus, les industries aérospatiales sont distribuées de par le monde. Dans cecontexte complexe, il est nécessaire d’utiliser la réalité virtuelle afin de proposerdes environnements virtuels accessibles depuis des sites distants afin departager une expérience collaborative. Des problèmes particuliers, alors, surviennent,particulièrement par rapport à la perception des autres utilisateursimmergés.Cette thèse, en partenariat avec Airbus Group, se concentre sur la conceptionde techniques d’interaction collaboratives efficaces. Ces sessions collaborativespermettent de connecter plusieurs sites distants via le même environnementvirtuel. Ainsi, des experts de domaines variés peuvent travailler ensembleen étant immergés simultanément. Par exemple, si un problème survient durantles dernières étapes d’assemblage d’un lanceur, il peut être nécessairede rassembler des experts qui étaient impliqués en amont du projet (bureaud’étude pour la conception, usine pour la fabrication des systèmes), afin deconcevoir des solutions pour résoudre le problème.Dans cette thèse, nous proposons différentes techniques d’interactions afinde faciliter la collaboration à différents niveaux d’un projet industriel. Nousnous sommes intéressés à la communication et la perception entre collaborateursimmergés, à la prise d’annotation et la circulation de ces annotations età la collaboration asymétrique entre une salle de réunion et un environnementvirtuel à l’aide d’outil de réalité mixte. / The aerospace industry is no longer composed of local and individualbusinesses. Due to the complexity of the products (their size, the numberof components, the variety of systems, etc.), the design of an aircraft or alauncher involves a considerable number of engineers with various fields of expertise.Furthermore, aerospace companies often have industrial facilities allover the world. In such a complex setting, it is necessary to build virtual experimentsthat can be shared between different remote sites. Specific problemsthen arise, particularly in terms of the perception of other immersed users.We are working with Airbus Group in order to design efficient collaborativeinteraction methods. These collaborative sessions allow multiple sites to beconnected within the same virtual experiment and enable experts from differentfields to be immersed simultaneously. For instance, if a problem occurs duringthe final stages of a launcher assembly, it may be necessary to bring togetherexperts on different sites who were involved in previous steps ( initial design,manufacturing processes). In this thesis, we propose various interaction technique in order to ease thecollaboration at different moments of an industrial process. We contributedin the context of communication between immersed users, taking notes inthe virtual environment and sharing it outside virtual reality and asymmetriccollaboration between a physical meeting room and a virtual environment.

Subtractive manufacturing are the most common methods in the aerospace industry to manufacture components. In these parts the buy to fly ratio is low and it needs accurate strengths analyses to static and dynamic loads especially were the different parts relate to each other with fasteners in the assembly work. Additive manufacturing has now been developed to be of such quality that the aerospace industry see the potential to use the technology in their production of parts. It has been possible to make them lighter, stronger and reduce the total amount of parts in an assembly. This mean probably some changes to the stakeholders in the process of their product development. Engineers who are working on the products will need to face the design aspects and restrictions with AM to choose the right component/sub-assemblies to convert to AM parts. This thesis will address the possibility to redesign a wing rudder and to get some knowledge about the engineer’s point of view of AM and how it may affect them. Today there are several aerospace industries adopting AM and get airworthy components to less critical parts as brackets but also parts in the engines as the fuel nozzle in an Airbus (Trimble, 2016). For larger parts, there have also been studies to use AM for example internal galley partition but the result is it will take too long time to print by todays machines. There are several different methods for AM and Powder Bed System is popular in the aerospace industry according to its geometrical correctness to the CAD model (Dordlofva, Lindwall, & Törlind, 2016). Commercial aircrafts industry starts to get harder regulations for their emissions to get lighter planes and less air resistance. AM open up the possibilities to meet these requirements by producing parts which was impossible to produce before. The design process for AM design today are not fully known yet, which leave a lot to imagination. There are general design rules on how to design for AM build but it does not necessary mean the part will be correctly built. There are several cost driven aspects with AM, the most expensive part is the print time but there are different aspects to. For example, CNC machining may be needed after the AM build and add cost for subtractive manufacturing. Interviews with engineer’s groups have been made to conduct their thoughts and knowledge of AM and how it may affect their work. Some uncertainties were mentioned and it was most focused on the process and the reliability of the finished part. The engineers think the design process will be almost the same and only change boundary conditions. To get ideas, a workshop was made with some design guidelines for development of different designs on the wing rudder and to bring positive and negative aspects to the design. An overall cost calculation was made for a few parts and the result shows that it is hard to compete with the design of the wing rudder today. The most important aspects for a success of AM is the print speed, qualified manufacturing processes and CAD software support for the engineers. / Flygindustrin använder sig främst av subtraktiv bearbetning i sin framställning av de olika komponenterna till ett flygplan. Det blir då ofta en väldigt låg grad av materialutnyttjande, endast några procent återstår av det inköpta utgångsmaterialet. Till det tillkommer monteringsarbete och noggranna hållfasthetsanalyser, både statisk och utmatningshållfasthet av sammanbyggda skarvar där fästelement är en del. Den additiva tillverkningen har nu utvecklats och visat sig inneha kvalitéer för att klara kraven som ställs i flygindustrin. Det kan göra detaljerna lättare, starkare och minska antalet komponenter i monteringsarbetet. Det kan innebära en hel del förändringar för olika intressenter som får börja tänka annorlunda. Ingenjörer som arbetar med produktframtagning kommer att ställas inför utmaningen att applicera denna teknik på lämpliga delar/delkonstruktioner. Detta examensarbetet undersöker möjligheten att designa ett vingroder till ett flygplan och bilda en uppfattning om ingenjörernas förtroende för additiv tillverkning samt hur det kommer påverka dem. Det finns idag flera flygindustrier som har påbörjat att ta fram flygvärdiga komponenter, framförallt mindre kritiska fästelement men även en del artiklar i motorer så som bränslemunstycke hos Airbus (Trimble, 2016). De har analyserat möjligheten att använda additiv tillverkning på större artiklar såsom inre kabinstruktur men har kommit fram till att det tar för lång tid att tillverka med dagens maskiner. Det finns flertalet olika additiva tillverkningsmetoder men den som står ut är pulverbäddskrivaren då den har en bättre geometrisk korrekthet gentemot CAD modellen (Dordlofva, Lindwall, & Törlind, 2016). Nya reglementen för utsläpp i den komersiella flygindustrin pressar företagen att bygga bättre flygplan som är lättare och därmed får mindre luftmotstånd. Designprocessen för additiv tillverkning är inte given då det inte finns några givna processer som täcker hela processen. Det finns generella design-riktlinjer i vad de olika maskinerna klarar av att bygga, men samtidigt är det ingen garanti att genom att följa dessa riktlinjer skapa en fungerande design. Det finns flera olika kostnadsdrivande aspekter med additiv tillverkning. Det som mest driver kostnaden idag är den låga skrivarhastigheten. Andra kosnadsdrivare är om det tillkommer efterarbete för att uppfylla toleranser eller få en korrekt / plan sammanfogningsyta. Arbetet har utförts med intervjuer av ingenjörsgrupper för att skapa en uppfatting om deras syn på additiv tillverkning och hur det skulle ändra deras arbete. En viss osäkerhet förekom men det berodde framförallt på osäkerheten för säkring av processen, dvs tillverkningsprocessen och att kunna vara säker på att detaljen håller måttet. De ansåg att designprocessen inte skulle förändras så mycket, utan bara att randvillkoren skulle ändras. Utifrån workshops och designriktlinjer har koncept tagits fram och utvärderats med för och nackdelar. En översiktlig kostnadskalkyl har gjorts som visar på att det blir svårt att designa roder som en större enhet för additiv tillvekning som är ekonomiskt jämförbart med dagens tillverkingsmetoder. De viktigaste framgångsfaktorerna för additiv tillverkning är ökad skrivarhastighet, kvalificering av tillverkningsprocesserna och CAD stöd för ingenjörerna.

Trust is an integral part in a supplier-buyer relationship. Especially in highly technological industries like the automotive- and aerospace industry this topic is of great importance. However, in contrast to the factors affecting the trust building process, which are researched very well, trust deterioration, its indicators, and counteractions to prevent trust deterioration were overlooked so far. The purpose of this study is to categorize different factors for trust as well as to contribute knowledge to trust deterioration by finding indicators and counteractions to prevent this. The study is partly based on the model of perceived trustworthiness and its three dimensions by Mayer, Davis and Schoorman (1995). One aim of this thesis is to proof if all three dimensions still fit within both industries. Furthermore, a deductive research approach was used in order to research the suppliers’ perspective in both industries regarding trust and indicators as well as counteractions of trust deterioration. Our findings show that the dimensions’ ability and integrity from Mayer, Davis and Schoorman (1995) are still important to build trust. Furthermore, the study contributes to the not existing research by exploring several indicators of trust deterioration as well as highlighting three counteractions to prevent trust deterioration. Consequently, a trust deterioration framework is given to show the general connection between trust and indicators as well as counteraction of trust deterioration.

The aim of this master's thesis is experimental electric discharge sinking of special materials for the aerospace industry. The first part is a general overview regarding the technology of electric discharge machining with emphasis on electric discharge sinking. Following this is a practical part devoted to the electric discharge sinking of the Nimonic 263 material with a copper tool electrode with a subsequent evaluation of surface and subsurface changes in this material. The wear of the tool electrode is also examined with the conclusion highlighting combination of machined material and tool electrode material behave in different working conditions and how the surface layer of machined material is affected.

With the ongoing transformation of modern manufacturing systems in an industry 4.0 environment, industrial actors may see great improvements with respect to quality towards a state of near zero defects. For the aerospace industry, where increased quality and reduced risk is strongly related, new technologies may be used in manufacturing to see to the increasing demands on products. The safety, as well as the manufacturing complexity of products and processes, make the collected measurement data an integral asset for enterprises within the aerospace industry. Collected data may be analysed using statistical tools and methods to improve process capability and, in extension, product quality. Communicating the need for zero defects, original equipment manufacturers demand increased capability from product and component manufacturers. Hence, zero defects are typically operationalised through exhibiting a process capability of Cpk= 2.0. In response to the challenge, GKN Aerospace need to raise the traditional process capability targets of Cpk=1.33. By employing an exploratory research strategy with a deductive approach, the thesis combines theoretical knowledge from the literature with empirical findings in a thematic analysis. The thematic analysis was conducted by employing six phases as suggested by Braun and Clarke (2006) and resulted in the identification of 50 codes from a total of 459 data extracts. Based on the empirical interview data, a framework for how zero defects is interpreted at GKN Aerospace was developed, which describes zero defects as a cycle. Taking into account that zero defects is operationalised through Cpk= 2.0, the cycle consists of six phases that start with a vision and is completed by delivering a true and reliable Cpk of 2.0. In addition, the codes from the thematic analysis were collated into a thematic mind map, focusing on key aspects of working with statistical process control (SPC) to support zero defects. Two main themes are presented in the mind map, statistical approach to improvement work; highlighting necessary aspects of statistical process control and measurability, and removing barriers for improvement; highlighting fundamental organisational barriers that impede proactive quality improvement. To support the findings and give a practical example of how process data may be presented and analysed using tools and methods within statistical process control, an SPC study was conducted on a set of data. In the SPC study, the construction and analysis of individuals Shewhart control charts and moving range charts were described in detail. These procedures provide better insights about process behaviour through statistical thinking and thus better knowledge on how to approach more proactive process improvements.

Metal additive manufacturing can be used for producing complex and functional components in the aerospace industry. This thesis deals with the process-structure-property relationships in selective laser melting of three aerospace alloys: Invar 36, stainless steel 316L, and Ti-6Al-4V. These alloys are weldable but hard to machine, which make them good candidates for the selective laser melting process. Invar 36 has a very low coefficient of thermal expansion because of its nickel concentration of 36% and stainless steel 316L contains 16-18% chromium that gives the alloy a corrosion resistance property. Ti-6Al-4V offers high strength-to-weight ratio, high biocompatibility, and outstanding corrosion resistance. Any changes in the chemical composition of these materials could affect their performance during application. In this thesis, a full factorial design of experiments is formulated to study a wide range of laser process parameters. The bulk density, tensile mechanical properties, fractography, microstructure, material composition, material phases, coefficient of thermal expansion, magnetic dipole moments, and residual stresses of the parts produced are experimentally investigated. An optimum process window has been suggested for each material based on experimental work. The thermal cycle, residual stresses, and part distortions are examined using a thermo-mechanical finite element model. The model predicts the residual stress and part distortion after build plate removal. The thesis introduces two laser energy densities for each material: brittle-ductile transition energy density, ET, and critical laser energy density, EC. Below the brittle-ductile transition energy density, the parts exhibited void formation, low density, and brittle fracture. Above the critical energy density, the parts showed vaporization of some alloying elements that have low boiling temperatures. Additionally, real-time measurements were taken using a pyrometer and a high-speed camera during the selective laser melting process. The trends found in the numerical results agree with those found experimentally. / Thesis / Doctor of Philosophy (PhD)

Open innovation is a new research line that emerges from a new industrial organization of research, development and innovation (R,D&I): after a period of vertical integration and accumulation, economy seems to walk towards a more plain level with lesser barriers to new entrants due to a new scenario of collaboration and knowledge dissemination. In this new mindset, firms can and should use external ideas as well as internal ideas, and internal and external paths to market, as firms look to advance in their technologies. The general goal of this research project is to analyze the depth and the impact of open innovation practices, as well as to identify patterns of their integration to the product development process (PDP) with focus on aerospace, a traditional high-tech segment within the metal-mechanic sector. For such, a reference model is elaborated and analyzed in two different contexts, in comparison study between Brazilian (emerging economy) and Canadian (developed economy) industries, more specifically the aerospace clusters in São Paulo and Quebec. The research comprises an aerospace market analysis, as well as the study of both countries national systems of innovation, supported by a survey that measures the intensity and importance of open innovation in Brazilian and Canadian aerospace companies plants. The survey is carried out by means of in-company questionnaire-based face interviews with R&D managers. The sample of analysis comprises a total of 53 aerospace plants, 22 of them in Brazil and 31 in Canada. Through a descriptive analysis of survey data, it is possible to identify similarities and differences in the patterns of open innovation in the two clusters. Among the similarities one highlights the focus on the product, the early involvement of customers in the PDP, the strategies adopted regarding intellectual property (IP) protection, the concentration of collaborative arrangements within the boundaries of the aerospace industry and the low intensity use of pecuniary tools, such as venture capital, spin-offs and/or acquisitions. Among the differences, Canada stands out with respect to its innovation public policies and assistance programs, which are found to be more effective in relation to Brazilian policies. Besides, Canadian plants seem to have a better innovative performance, at the cutting edge of aerospace technologies and higher international relevance. The survey also finds that the intensities of openness in Brazil and Canada are quite similar, although the patterns and motivations differ: Brazilian plants are more engaged in providing R&D services for products of third parties under direct contract (and not within collaborative arrangements) to local customers, while Canadian plants seem to be more engaged in a wider spam of collaborative fronts in a wider geographical range. Besides, Brazilian plants are much less intense in the adoption of formal IP protection methods in relation to Canadian ones, which hinders (but not prevents) the full adoption of open innovation in the Brazilian cluster. Based on the results, this text concludes with recommendations directed to the three vertices of the triple helix in both countries, namely: enterprises, science and technology institutes and the government. / A inovação aberta é uma nova linha de pesquisa que surge a partir de nova organização industrial de pesquisa, desenvolvimento e inovação (P,D&I): após um período de verticalização, a economia parece caminhar em direção a um maior nivelamento com menores barreiras para novos entrantes em um novo cenário de colaboração e disseminação de conhecimento. Neste conceito, as empresas podem e devem usar ideias externas, assim como internas, e caminhos internos e externos para o mercado, na medida em que buscam avançar suas tecnologias. O objetivo geral deste projeto é analisar a profundidade e impacto das práticas de inovação aberta, bem como identificar padrões de sua integração ao processo de desenvolvimento de produtos (PDP) com foco na indústria aeroespacial, um segmento tradicional de alta tecnologia no setor metal-mecânico. Para tal, um modelo de referência é elaborado e avaliado em diferentes contextos, em uma comparação entre as indústrias brasileira (economia emergente) e canadense (economia desenvolvida), mais especificamente os arranjos produtivos aeroespaciais em São Paulo e Quebec. A pesquisa compreende uma análise do mercado aeroespacial, bem como o estudo dos sistemas nacionais de inovação de ambos os países, apoiados por um levantamento (survey) que mede a intensidade e a importância da inovação aberta em plantas de empresas aeroespaciais no Brasil e no Canadá. A pesquisa é realizada por meio de entrevistas presenciais em empresas com gestores de P&D, baseadas em um questionário. A amostra compreende um total de 53 plantas de empresas aeroespaciais, 22 delas no Brasil e 31 no Canadá. Através da análise descritiva dos dados da pesquisa, é possível identificar semelhanças e diferenças nos padrões de inovação aberta nos dois grupos. Entre as semelhanças destacam-se o foco no produto, o envolvimento precoce de clientes no PDP, as estratégias adotadas para proteção de propriedade intelectual (PI), a concentração de acordos colaborativos dentro dos limites da indústria aeroespacial e a baixa intensidade na utilização de ferramentas pecuniárias, tais como o capital de risco, spin-offs e/ou aquisições. Entre as diferenças, o Canadá se destaca com relação às suas políticas públicas de inovação e programas de assistência, que se mostram mais eficazes em relação aos brasileiros. Além disso, as plantas canadenses parecem ter um melhor desempenho inovador, mais próximo do estado-da-arte das tecnologias aeroespaciais e com maior relevância internacional. O levantamento também mostrou que as intensidades de abertura no Brasil e no Canadá são semelhantes, embora os padrões e motivações difiram: as plantas brasileiras estão mais envolvidas no fornecimento de serviços de P&D para produtos de terceiros sob contrato direto (e não dentro de acordos de colaboração) para clientes locais, enquanto que as plantas canadenses parecem estar engajadas em um leque mais amplo de frentes de colaboração, com maior distribuição geográfica. Além disso, as plantas brasileiras adotam com muito menor intensidade métodos formais de proteção da PI em relação às canadenses, o que dificulta (mas não impede) a adoção plena da inovação aberta no cluster brasileiro. Com base nos resultados, o texto conclui com recomendações dirigidas aos três vértices da hélice tripla em ambos os países, a saber: empresas, institutos de ciência e tecnologia e governo.

Made available in DSpace on 2016-06-02T19:12:30Z (GMT). No. of bitstreams: 1 5457.pdf: 7456737 bytes, checksum: 1d18f487e08219cebbd323e719bd80ff (MD5) Previous issue date: 2012-10-27 / Precipitation Hardening Stainless Steel PH13-8Mo is a high strength steel used in the aerospace industry. Beyond the high strength, this grade has relatively high toughness and ductility for the strength achieved. The aerospace industry is increasingly asking for high strength materials with higher toughness and ductility than the actual limits required. Villares Metals, manufacturer of specialty steels and alloys, supplies the 13-8 steel (Villares grade N4534QA) for the aerospace industry like Embraer and ELEB (landing gear manufacturer of Embraer aircrafts). Although Villares 13-8 steel meets the international and the aerospace specifications, is characteristic of this company to improve its products and follow the new requirements of the customers and the market. Thus, is of its interest to produce the 13-8 steel with higher toughness and ductility. Therefore, the objective of this work is to study the variables which affect the 13-8 steel toughness and ductility aiming to produce it with improved properties. It were studied the effect of the alloying and residual elements, steelmaking process (remelting), hot forming process (forging and rolling) and heat treatment process. The verification of these effects was verified through tensile and impact Charpy V tests. / O aço inoxidável endurecível por precipitação PH13-8Mo (13-8) é um aço de elevada resistência mecânica utilizado na indústria aeronáutica. Além da elevada resistência mecânica, este aço possui ductilidade e tenacidade relativamente elevadas para o nível de resistência atingido. A indústria aeronáutica vem, cada vez mais, solicitando materiais de alta resistência mecânica com tenacidade e ductilidade mais elevadas em relação às solicitações atuais. A Villares Metals, usina siderúrgica produtora de aços e ligas especiais, é fornecedora do aço 13-8 (marca Villares N4534QA) para as indústrias do segmento aeronáutico, como Embraer e ELEB (fabricante dos trens de pouso dos aviões da Embraer). Apesar do aço 13-8 da Villares Metals atender as principais normas internacionais e do segmento aeronáutico, é prática desta empresa estar sempre buscando melhorar os seus produtos e acompanhar as novas solicitações dos clientes e do mercado. Sendo assim, é de seu interesse produzir o aço 13-8 com tenacidade e ductilidade mais elevadas. Portanto, o objetivo deste trabalho é estudar as variáveis que afetam a tenacidade e a ductilidade do aço 13-8 com o objetivo de se obtê-lo com estas propriedades otimizadas. Foram estudados os efeitos de elementos de liga, de elementos residuais, do processo de elaboração (refusão), dos processos de conformação a quente (forjamento e laminação) e do processo de tratamento térmico. A verificação desses efeitos foi realizada através de ensaios mecânicos de tração e de impacto Charpy V.

Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-10-11T20:12:25Z No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:58:59Z (GMT) No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:59:07Z (GMT) No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Made available in DSpace on 2016-10-21T12:59:15Z (GMT). No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) Previous issue date: 2016-05-19 / Não recebi financiamento / This dissertation studies the application of a periodic review inventory model based on the multiperiod newsboy problem, as an effective alternative to reach a well balanced inventory planning policy of subcontractors primary parts area of the aerospace industry. In Brazil, the aerospace industry is responsible for a large amount of the country exports and this industry competes with other globally aerospace supply chains in a scenario increasingly turbulent and demanding for fast deliveries, with high quality levels and low cost. The purpose of this work is to study and propose this alternative for optimizing the inventory planning by means of a quantitative approach, applied in a primary parts sector of the aerospace industry, it will focus in a specific group of items with high annual demand value. The main objective of this approach is to balance the high inventory costs with a high service level demanded in this industry, and efficiently respond the stakeholders expectations, with superior performance of the usual models adopted by this industry, and give a better support to the decision makers in a tactical-operational level. The result obtained show the potential of the method to improve the performance of these inventory management and planning systems. / Este trabalho estuda a aplicação de um modelo analítico de revisão periódica de estoques, baseado no problema do jornaleiro multiperíodo (Multiperiod Newsboy Problem), como uma alternativa efetiva para determinação da política de planejamento de estoques do setor de peças primárias subcontratadas da indústria aeroespacial. No Brasil, a indústria aeroespacial é responsável por grande parte das exportações do país e compete globalmente com outras cadeias aeroespaciais num cenário cada vez mais turbulento e exigente por entregas rápidas, com altos níveis de qualidade e baixos custos. O objetivo deste trabalho é estudar e propor essa alternativa para otimizar o planejamento de estoques por meio de uma abordagem quantitativa, aplicada no setor de peças primárias da indústria aeroespacial, para um grupo de peças com características especificas, principalmente as de alto valor para demanda anual. O intuito desta abordagem é equilibrar os altos custos de estoque com os altos níveis de serviço exigidos por esta indústria, e responder de forma eficiente às expectativas dos stakeholders, com desempenho superior aos modelos atualmente utilizados no setor e auxiliar de forma mais precisa e sistematizada a tomada de decisão no nível tático-operacional. Os resultados obtidos mostram o potencial do método para melhorar o desempenho desses sistemas de gestão e planejamento de estoques.

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-06-22T11:45:07Z No. of bitstreams: 0 / Made available in DSpace on 2016-06-22T11:45:07Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP