Atualmente, uns dos grandes desafios para a indústria automobilística é aumentar o desempenho do conjunto mecânico responsável por selar a câmara de combustão interna de motores automotivos e também reduzir os seus custos de obtenção. O objetivo deste trabalho foi o de tratar termicamente insertos de assentos de válvulas (do inglês valve seat insert, VSI) obtidos pela rota de metalurgia do pó. Esta técnica possibilitou a substituição do cobalto e do chumbo, devido ao seu elevado custo e efeito toxicológico, respectivamente. Ao longo do trabalho foram avaliados VSI obtidos com três misturas de pós diferentes, sendo que os elementos comuns nestas três misturas foram os pós de ferro, sulfeto de manganês, carboneto de nióbio, grafite, estearato de zinco e cobre. Em cada uma destas misturas variou-se apenas os tipos de pós de aços rápidos e aço ferramenta utilizado, sendo estes o aço rápido AISI M3:2 (Mistura 1), aço rápido AISI M2 (Mistura 2) e aço ferramenta AISI D2 (Mistura 3). Os tratamentos térmicos aplicados aos VSI consistiram em têmpera ao ar e têmpera ao óleo, ambas seguidas de duplo revenimento em sete temperaturas equidistantemente diferentes, variando de 100 °C a 700 °C. Os ciclos dos tratamentos térmicos foram determinados por meio da utilização de termopares do tipo k acoplados à um sistema de aquisição de dados. As propriedades físicas e mecânicas dos VSI foram determinadas através da dureza aparente, densidade aparente e resistência à ruptura radial. A caracterização microestrutural foi realizada utilizando-se a microscopia óptica e microscopia eletrônica de varredura. A composição química foi determinada por meio da análise elementar e por espectrometria de fluorescência de energia dispersiva de raios X. Os melhores resultados em relação às propriedades mecânicas dos VSI foram obtidas para os insertos temperados ao ar e duplamente revenido a 600 °C para a Mistura 1 e Mistura 2, e a 500 °C para Mistura 3. Já para a têmpera ao óleo, as melhores respostas foram para os VSI obtidos com a Mistura 1 duplamente revenida a 400 °C e a, 300 °C para os componentes obtidos com a Mistura 2 e Mistura 3. / Currently, one of the biggest challenges for the automobile industry is to increase the performance of the mechanical set responsible for sealing the internal combustion chamber in automotive engines and reduce its cost of production. The aim of the present work was to heat treat valve seat inserts (VSI) obtained through the powder metallurgy route. This procedure made possible the substitution of cobalt and lead, due to its high cost and toxicological effect, respectively. Throughout the work, it was evaluated VSI obtained with three different types of powders mixtures, and common elements at the three different powders mixtures were iron powder, manganese sulfide, niobium carbide, graphite, zinc stearate and copper. In each of these powders mixtures, it was changed only the type of high-speed steels and tool steel, consisting of high-speed steel AISI M3:2 (Mixture 1), high-speed steel AISI M2 (Mixture 2) and tool steel AISI D2 (Mixture 3). The heat treatments applied to the VSI were air quenching and oil quenching, both followed by double tempering at seven different equidistantly temperatures, ranging from 100 °C up to 700 °C. The heat treatments thermal cycles were determined using a thermocouple type k attached to a data acquisition system. The physical and mechanical properties of the VSI were measured in terms of apparent hardness, apparent density and crush radial strength. Microstructural characterization was performed using optical and scanning electron microscopy. The chemical composition was determined using gas analysis and energy dispersive X-ray fluorescence spectrometry. The best results regarding the mechanical properties of the VSI were obtained for the VSI air-quenched and double tempered at 600 °C for the powder Mixture 1 and Mixture 2, and at 500 °C for Mixture 3. For the oil quenching, the best response was reached for the VSI obtained with Mixture 1 double tempered at 400 °C, and at 300 °C for the components obtained with Mixture 2 and Mixture 3.

Made available in DSpace on 2014-06-11T19:30:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2001Bitstream added on 2014-06-13T20:21:20Z : No. of bitstreams: 1 azevedo_gc_dr_botfm.pdf: 1468738 bytes, checksum: 5d4e12fc75c354ee245a948583564151 (MD5) / Este trabalho experimental propõe uma nova e eficiente técnica para in-trodução de parafuso no processo articular cervical, com menor risco. Utilizando um novo dispositivo e determinando o comprimento efetivo médio do parafuso. Foram usadas cinco colunas cervicais de esqueleto humano de C3 a C7, num total de 25 vértebras e 50 perfurações. Foram selecionados dois grupos de vértebras: um de C3 a C6, outro de C7. No primeiro grupo, o ponto inicial do parafuso situou-se a 2 mm. mediais e caudais do ponto central do processo articular, dirigindo-se a ponta do parafuso a 21,5º no sentido cranial. No outro grupo, o ponto inicial foi localizado a 2mm. da linha média vertical, logo abaixo da superfície articular superior, dirigindo-se a ponta do parafuso a 16,5º no sentido caudal. Em ambos os grupos, o parafuso foi desviado lateralmente a 42,5º. Concluímos que a nossa técnica é eficiente e segura porque: 1) utiliza um dispositivo que mede o ângulo de introdução do parafuso, bloqueando-o após a ultrapassagem da cortical anterior, introduzindo somente o comprimento ideal para cada processo articular, diminuindo o risco de lesão; 2) não causa lesão da artéria vertebral e da raiz nervosa; 3) apresenta baixa incidência de violação da superfície articular, 7,5% nas vértebras C3 a C6 e 0% nas C7; 4) apresenta um comprimento efetivo do parafuso de 10,7 mm. para ambos os grupos vertebrais oferecendo boa fixação óssea e boa margem de segurança, em relação às estruturas anatômicas importantes. / This experimental paper presents a new and efficient technique to insert a screw in the cervical lateral mass with the less risk of damaging the vertebral artery, the nerve root and the articular facet. This procedure is carried out by using a new device which measures the screw insertion angle and lock the screw after it goes through the posterior cortical area. This paper also aims at determining the effective screw length to be used in this technique. Five human lower cervical spines from C3 to C7 - were used. Two holes were made in both sides of these 25 vertebrae. Therefore 50 holes were made. Two vertebrae groups were selected: C3-C6 and C7. In the C3-C6 group the start point of the screw was placed in a medial and caudal position 2mm. in relation to the central point of the articular prossece; the screw tip was directed to the half of the lateral vertebral line at a 21,5° angle in the cranial direction; for the C7 vertebrae the screw initial point was placed at a 2 mm. medial position in the vertical mean line just below the upper articular level; the screw tip was directed to the half of the lateral vertebral line at a 16,5° angle in the caudal direction. In both vertebral groups the screw was laterally deviated at a 42,5° angle. The conclusion is that this new technique is efficient and safe because: 1) it utilizes a new device to guide and measure the screw insertion and lock the screw after it goes through the posterior cortical area; the in-sertion is thus adequate for each specific lateral mass and decreases the risk of damage to the vertebral artery and to the nerve root; in fact it did not occur in both vertebral groups; 2) it presents a low rate of articular facet violation; 3) it presents a 10,7 mm. screw length which is effective for both vertebral groups; 4) therefore there occurs a good bone fixation and the important anatomic structures are preserved.

Atualmente, uns dos grandes desafios para a indústria automobilística é aumentar o desempenho do conjunto mecânico responsável por selar a câmara de combustão interna de motores automotivos e também reduzir os seus custos de obtenção. O objetivo deste trabalho foi o de tratar termicamente insertos de assentos de válvulas (do inglês valve seat insert, VSI) obtidos pela rota de metalurgia do pó. Esta técnica possibilitou a substituição do cobalto e do chumbo, devido ao seu elevado custo e efeito toxicológico, respectivamente. Ao longo do trabalho foram avaliados VSI obtidos com três misturas de pós diferentes, sendo que os elementos comuns nestas três misturas foram os pós de ferro, sulfeto de manganês, carboneto de nióbio, grafite, estearato de zinco e cobre. Em cada uma destas misturas variou-se apenas os tipos de pós de aços rápidos e aço ferramenta utilizado, sendo estes o aço rápido AISI M3:2 (Mistura 1), aço rápido AISI M2 (Mistura 2) e aço ferramenta AISI D2 (Mistura 3). Os tratamentos térmicos aplicados aos VSI consistiram em têmpera ao ar e têmpera ao óleo, ambas seguidas de duplo revenimento em sete temperaturas equidistantemente diferentes, variando de 100 °C a 700 °C. Os ciclos dos tratamentos térmicos foram determinados por meio da utilização de termopares do tipo k acoplados à um sistema de aquisição de dados. As propriedades físicas e mecânicas dos VSI foram determinadas através da dureza aparente, densidade aparente e resistência à ruptura radial. A caracterização microestrutural foi realizada utilizando-se a microscopia óptica e microscopia eletrônica de varredura. A composição química foi determinada por meio da análise elementar e por espectrometria de fluorescência de energia dispersiva de raios X. Os melhores resultados em relação às propriedades mecânicas dos VSI foram obtidas para os insertos temperados ao ar e duplamente revenido a 600 °C para a Mistura 1 e Mistura 2, e a 500 °C para Mistura 3. Já para a têmpera ao óleo, as melhores respostas foram para os VSI obtidos com a Mistura 1 duplamente revenida a 400 °C e a, 300 °C para os componentes obtidos com a Mistura 2 e Mistura 3. / Currently, one of the biggest challenges for the automobile industry is to increase the performance of the mechanical set responsible for sealing the internal combustion chamber in automotive engines and reduce its cost of production. The aim of the present work was to heat treat valve seat inserts (VSI) obtained through the powder metallurgy route. This procedure made possible the substitution of cobalt and lead, due to its high cost and toxicological effect, respectively. Throughout the work, it was evaluated VSI obtained with three different types of powders mixtures, and common elements at the three different powders mixtures were iron powder, manganese sulfide, niobium carbide, graphite, zinc stearate and copper. In each of these powders mixtures, it was changed only the type of high-speed steels and tool steel, consisting of high-speed steel AISI M3:2 (Mixture 1), high-speed steel AISI M2 (Mixture 2) and tool steel AISI D2 (Mixture 3). The heat treatments applied to the VSI were air quenching and oil quenching, both followed by double tempering at seven different equidistantly temperatures, ranging from 100 °C up to 700 °C. The heat treatments thermal cycles were determined using a thermocouple type k attached to a data acquisition system. The physical and mechanical properties of the VSI were measured in terms of apparent hardness, apparent density and crush radial strength. Microstructural characterization was performed using optical and scanning electron microscopy. The chemical composition was determined using gas analysis and energy dispersive X-ray fluorescence spectrometry. The best results regarding the mechanical properties of the VSI were obtained for the VSI air-quenched and double tempered at 600 °C for the powder Mixture 1 and Mixture 2, and at 500 °C for Mixture 3. For the oil quenching, the best response was reached for the VSI obtained with Mixture 1 double tempered at 400 °C, and at 300 °C for the components obtained with Mixture 2 and Mixture 3.

Electrons are weakly attracted to liquid helium due to the small but finite polarizability of helium atoms. However, they cannot enter the liquid unless their energy is more than 1 eV, due to the Pauli exclusion principle. As a result, electrons are bound perpendicular to the surface but are free to move parallel to the surface i.e., they form a two-dimensional electron system (2DES). If the electron density of the 2DES is increased above a critical value ( 1013 per m2) the surface becomes un-stable leading to the formation of charged bubbles known as multielectron bubbles (MEBs). In MEBs the electrons are confined to the inner bubble surface and hence we have a 2DES on a curved surface. The critical density of electrons on the bulk surface is too low to study the quantum dominated phases of the 2DES. In contrast, due to the enormous surface defects and impurities, the electronic density of 2DES in semiconductors cannot be lowered below 1015 per m2, which is high enough such that the 2DES is always in a quantum liquid phase. Alternatively, the possibility of varying the electron density over a wide range and the effects of curvature implies that MEBs can be used to probe new phases of 2DES like Wigner crystallization with strong electron-ripplon coupling, quantum melting, superconductivity etc. In this thesis the experiments done on MEBs in liquid helium are described. In the initial experiments we generated MEBs which were observed to shrink in size. We saw a difference in their collapse behaviour: MEBs in super fluid helium though initially bigger in size collapse much faster than MEBs generated in normal fluid. The vapour present in the MEBs cannot condense fast in normal fluid due to the lower thermal conductivity. In subsequent experiments, we could trap these MEBs, generated in normal fluid and stabilised by their vapour content, in a linear Paul trap. We measured the charge and radius of these trapped MEBs by analysing their dynamics. Interestingly, the stably trapped MEBs were found not to lose charge as they shrink and disappear in hundreds of milliseconds, implying that the charge density inside increases at least two orders of magnitude from the initial value. MEBs so trapped can be used to study the properties of 2DES in the high electron density limit where the quantum confinement energy dominates. Later, we measured the charge of the MEB with respect to time when it was held on a solid substrate. We propose a charge loss mechanism as the tunneling of electrons across a thin lm of helium formed between the MEB and the substrate. We estimated the density of electrons on this thin lm by using a numerical model. We found that the maximum electron density (about a few 1015 per m2) which could be held on a thin lm is limited by tunneling. Moreover, the substrate surface roughness did not affect the charge loss due to the microscopic contact of MEBs with the substrate, resolving the complications in charge loss observed in previous experiments on macroscopic thin films on metallic substrates. Finally, we describe the experiments and the results on the stability of MEBs generated in super fluid helium. Highly charged MEBs (with more than 104 electrons which have an equilibrium radius that is easily visible) are found to be unstable against fission into smaller bubble showing a type of electro-hydrodynamic instability. However, the stability of bubbles with radius less than our detection limit ( 1 m) is still an open question.

The thesis is focused on product certification of fireplace insert. There is described process of combustion of solid fuel and construction of fireplace insert with hot-water exchanger. The compilation of legislative requirements is compiled and confirmed by authorized test laboratory, and declaration of performance with production label with CE sign are made. In the next part, the emission requirements of European market are described, including future coming European directive. The energy label for certified product is designed.

Preliminary studies have stirred the hope that sound-field stimulation through auditory steady state evoked potentials can be used to assess aided thresholds in the difficult-to-test population. Before the introduction of ASSEP into the clinical field, as a technique for the prediction of aided thresholds in the difficult-to-test population, a question arises concerning its clinical validation. The application of ASSEP through sound field stimulation, in the determination of aided thresholds and for the evaluation of amplification fittings, is dependent on the determination of unaided responses. Subsequently the estimation of unaided thresholds in the hearing impaired population is dependent on the establishment of normative data from the normal hearing population. The aim of this study was to determine the influence of insert earphones and sound field speaker presentation on threshold estimations using monotic auditory steady state evoked potentials, in a group of normal hearing adults. To achieve the aim of the study, a comparative, within-group experimental design was selected. The results of the current study indicated that the monotic single ASSEP technique under both insert earphone- and sound field conditions provided a reasonable estimation (25-35 dB HL for inset earphones; 20-33 dB HL for sound field speaker presentation) of the behavioural pure tone thresholds. The minimum response levels obtained under insert earphone conditions differed significantly from those obtained under sound field conditions for all the frequencies tested except 2 kHz (p < 0.01). Subsequently, the current study indicates that minimum response levels obtained using a specific transducer should serve as the basis of comparison with behavioural thresholds obtained under the same transducer. Therefore, behavioural pure tone thresholds obtained under insert earphone conditions will not suffice as a basis of comparison for minimum response levels obtained for the ASSEP technique under sound field conditions, and vice versa. This research endeavour concluded that the monotic ASSEP technique under both insert earphone and sound field conditions provide useful information for the estimation of frequency specific thresholds, but that the results are transducer specific and that comparison across transducers should be avoided. / Dissertation (M (Communication Pathology))--University of Pretoria, 2006. / Speech-Language Pathology and Audiology / Unrestricted

Objective of this thesis is optimalization of route for inspectory technician. There were described traveling Salesman problem, vehicle Routing problem and it's modifications. Problem was solved by this three heuristics: nearest neighbour algorithm, savings method and insert method.

L’incise de citation a mauvaise réputation dans le champ narratif, où elle est pourtant fort utile pour indiquer la source des répliques : elle soulève de nombreuses polémiques, tant sur le plan de la théorie que de la pratique. Peu traitée par les études grammaticales, elle est souvent fustigée par les discours normatifs dès qu’elle s’écarte du prototypique dit-il, au nom de transgressions de certaines règles syntaxiques et logiques, décourageant les auteurs qui déplorent sa monotonie de la déjouer par des variations distributives et lexicales. Ce travail vise à exposer les difficultés analytiques soulevées par cette forme, qui voit bon nombre de ses réalisations rejetées comme incorrectes, et à s’interroger sur les fondements de tels jugements. Le parcours diachronique d’un vaste corpus narratif invite à reconsidérer sa monotonie, en rendant compte de son histoire, qui est celle d’une diversification formelle et fonctionnelle : bien plus que simple escorte du dialogue qui se contenterait d’en indiquer les actants, elle possède de nombreux rôles textuels qui font d’elle un enjeu narratorial et esthétique. / Interpolated clauses have a bad reputation in the narrative field, although they are very useful in indicating the source of lines ; they arouse numerous theoretical as well as practical controversies. Seldom dealt with in grammatical studies, they are often censured by normative discourses whenever they stray from the prototypical he said, as they transgress certain syntactic and logical rules. This censure discourages those authors who lament their monotony from trying to avoid this thanks to distributive and lexical variations. This study aims at showing the analytical difficulties that are raised by this form – many variants of which are rejected as incorrect –, and seeks to question the bases of such judgments. Looking at a vast, diachronic corpus of narrative texts invites us to qualify its monotony by accounting for its history, one of formal and functional diversification : interpolated clauses do not accompagny dialogues simply to point out their speakers, they have many textual roles that put them at the centre of narratorial and aesthetic issues.

The thesis is focused on product certification of fireplace insert. There is described process of combustion of solid fuel and construction of fireplace insert with hot-water exchanger. The compilation of legislative requirements is compiled and confirmed by authorized test laboratory, and declaration of performance with production label with CE sign are made. In the next part, the emission requirements of European market are described, including future coming European directive. The energy label for certified product is designed.

Submitted by Jakeline Ortega (jakortega@unoeste.br) on 2017-06-03T15:00:13Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tania Cristina Silva Pessoa.pdf: 736598 bytes, checksum: 589ef6defbf716efd48cf9d24cd152c7 (MD5) / Made available in DSpace on 2017-06-03T15:00:13Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tania Cristina Silva Pessoa.pdf: 736598 bytes, checksum: 589ef6defbf716efd48cf9d24cd152c7 (MD5) Previous issue date: 2016-11-30 / This study was attached to a research line titled “The School Education and Pedagogical practice of a Professional Teacher”, a part of the Postgraduate Program in Education from Universidade do Oeste Paulista, which has as theme the difficulties and problems that a teacher faces during its trajectory and professional insertion. The main idea was to identify and to analyze the construction of teacher’s identity through the perception of the beginning teachers at the moment of their career insertion, as well as understanding the conflicts and difficulties at this process. In a specific way, the research aimed to find out which are the dilemmas and the difficulties founded by teachers in the beginning of their career; to identify the formative activities that Public School System and schools provide to them and which one contribute to the construction of their identity; to investigate the moments that occurs the exchange of knowledge between the peers; to analyze the perception that this teachers have about their own formation at the professional context; to show the distance between beginning formation and practice and how this impact when they are inserted at the school environment.The methodology used was qualitative descriptive and interpretative, having as technical procedure a bibliographical research. The searches were done in digital databases such as Capes, SciELO e BDTD. For data collection it was used a questionnaire and a semistructured interview, applied to eight (8) beginner teachers of Rancharia – SP. For the data analysis, four categories were established according to Bardin (2009): The choice of teaching; Teacher’s insertion and the reality shock; Construction of professionalism and teaching identity and Future projections. As a result of the research, it was pointed that teachers who chose teaching career do that because they believe that there is a big professional field in the area; they also realize that the initial training was not enough to overcome with the problems that they deal with the profession, contextualizing such perceptions through "clash of reality”; they look for a recognition for their skills, constructing by this way , their daily identity as workers through action/reflection/action of their own pedagogical practice and continuous formation to keep into their profession. Therefore, we concluded that this study can create discussions and reflections about policies to support beginner teachers and process of teacher’s formation. / Esta pesquisa vinculou-se à linha de pesquisa intitulada "Formação e Prática Pedagógica do Profissional Docente", do Programa de Pós-Graduação em Educação da Universidade do Oeste Paulista, que teve como temática a problematização da trajetória docente e as dificuldades em sua inserção profissional. O objetivo foi identificar e analisar a construção da identidade docente, a partir do olhar do professor iniciante no momento de sua inserção na carreira, bem como compreender os conflitos e dificuldades neste processo. Buscou-se verificar os dilemas e dificuldades encontrados no seu início de carreira; identificar atividades formativas que a Rede Pública de Ensino e a escola oferecem a estes professores e que colaboram para a construção de sua identidade; investigar os momentos em que ocorre a troca de saberes entre os pares; averiguar a percepção que os professores iniciantes têm a respeito de sua própria formação no contexto profissional; explicitar o distanciamento que há entre a formação inicial e a prática docente e a implicação no momento de sua inserção no ambiente escolar. A metodologia teve uma abordagem qualitativa, de caráter descritivo-interpretativo. Como procedimento realizou-se uma pesquisa bibliográfica com buscas nas bases de dados digitais como Capes, SciELO e BDTD, e para a coleta de dados, utilizou-se questionário e entrevista semiestruturada, aplicada a oito docentes iniciantes da Rede Municipal de Rancharia/SP. Para as análises foram construídas quatro categorias segundo Bardin (2009), a saber: A escolha da docência; Inserção docente e o choque da realidade; Construção da profissionalidade e Identidade docente e Projeções futuras na docência. Os resultados da pesquisa indicaram que os professores ingressantes na carreira docente o fazem porque acreditam que há um maior campo de atuação profissional na área; percebem que a formação inicial não foi suficiente para suprir os problemas com os quais se deparam na profissão, contextualizando tais percepções por meio do “choque com a realidade”; desejam ver o resultado dos seus trabalhos reconhecidos por suas competências, construindo, desse modo, a identidade profissional diária, a partir da ação/reflexão/ação da sua própria prática pedagógica e a busca de formação continuada para prosseguir na profissão docente. Concluímos que esse estudo poderá suscitar discussões e reflexões sobre políticas de apoio ao professor iniciante e processos de formação de professores