Un nombre croissant d’études académiques et de rapports d’organismes internationaux relèvent une dépendance accrue des nouvelles technologies de l’énergie vis-à-vis d’une catégorie de ressources souvent prénommés métaux rares. Parallèlement, il se forme depuis plusieurs années des inquiétudes sur la disponibilité économique de ces métaux pour opérer la transition énergétique nécessaire à la lutte contre le réchauffement climatique. Cette thèse a donc pour objectif de souligner l’ensemble des contraintes et des risques qu’implique l’usage fréquent et généralisé de ces métaux dans les nouvelles technologies de l’énergie. Une première partie de la thèse est consacrée aux indicateurs et aux théories reliées à la disponibilité économique de long terme d’une ressource non renouvelable tout en faisant apparaitre un ensemble de traits communs partagés par les métaux rares. La seconde partie de cette thèse démontre les risques attachés à une absence d’élasticité prix de l’offre de métaux rares du fait d’une contrainte de sous-produit. Elle offre également une analyse approfondie des causes et des conséquences relatives à l’absence de marché à terme pour la quasi-totalité de ces métaux rares. Enfin, son dernier chapitre propose d’explorer la liaison très forte existant entre le secteur de l’énergie et le secteur des métaux. Il y est démontré que cette connexion s’accentue et qu’elle implique la possibilité d’un cercle vicieux entre des énergies toujours moins concentrées (avec un contenu en métaux grandissant) et des métaux qui consomment toujours plus d’énergie sous l’effet de leur épuisement. / A growing number of academic studies and international organizations reports have noticed an increasing dependency of new energy technologies on a specific class of natural resources often called minor metals. For several years, worries about economic availability of these metals in order to realize the energy transition have appeared. This thesis aims at underline the broader risks and constraints involved by general use of these metals in new energy technologies. A first part of this thesis is devoted to theories and indicators related to the depletion of non renewable resources. This part also shows that minor metals share many characteristics and that they can form a group of metal consistent. In a second part, this thesis addresses the issues linked to the absence of price elasticity for the supply of minor metals due to the byproduct constraint. Another chapter offers an analysis of causes and consequences connected to the absence of futures markets for almost all minor metals. Finally, a last chapter highlights the strong link existing between the energy sector and the metals sectors. This connection is increasing and can create a vicious circle between energies which are less and less concentrated and metals which consume more and more energy due to their depletion.

This Master's Thesis deals with burn-out syndrome in pedagogical community. The aim of this Master's Thesis is to work out the komplex analysis of this disease, where the initial part deals with the definition of burn-out syndrome as a disease of contemporary society and with the theoretical specifications of the syndrome. That is followed by analysis of reasons and causes of the syndrome which describes its symptoms and phases of evolution. The Master's Thesis also defines the possibilities of healing and therapy including methods of prevetion, avoiding or coping with the syndrome. Next part is focused on characteristics and specifications of the teaching profession. This section of the Thesis deals with the causes and hypotetical propensity of pedagogues to the disease, then with professional requirements on pedagogues and with specific reasons for the occurence of the syndrome in this professional community. The aim of the practical part of the Thesis is to create a case study describing a specific case of the burn-out syndrome of one respondent from the pedagogical community. The case study is based on a qualitative research using semi-structured interviews with this respondent. The research is supported by interviews with the respondent's colleagues, employer and therapist. Also some other additional research methods are used to complete the complex picture of the situation and to deepen the comprehension of this specific case.

Orientador: Carlos K. Suzuki / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-31T20:22:15Z (GMT). No. of bitstreams: 1 Argonz_Raquel_D.pdf: 6011460 bytes, checksum: 288a8671c5c8ed96310d3c57226ce9c8 (MD5) Previous issue date: 2001 / Resumo: O Brasil é na atualidade um dos principais produtores de silício para o mundo, sendo que a quantidade de quartzo extraído para a sua produção incluindo o ferro-silício, é da ordem de 2 milhões de toneladas/ano. Para a obtenção do quartzo destinado à redução carbotérmica em silício, nos diversos estágios de extração, britagem, seleção, transporte, e lavagem, cerca de 300.000 toneladas/ano de lascas de quartzo tomam-se rejeitos. Neste trabalho foi desenvolvida uma metodologia ambientalmente correta, denominada "quench-Ieaching" e "crush-leaching", que se utiliza da lixiviação aquosa para a purificação deste material. Os resultados mostram que ocorre uma remoção efetiva de impurezas majoritárias nas lascas de quartzo, tais como, AI, Fe, Na, K, Ca, Mn, ..., dando-lhe uma pureza de 99,9% de SI 'O IND 2'. Uma comparação com diversos insumos de quartzo produzidos no exterior para uso em tecnologia avançada, como para produção de sílica vítrea translucente e "fillers" de "micro-chips", revela que este material purificado com esta tecnologia toma-se de qualidade equivalente ao pó de quartzo internacional / Abstract: Nowadays, Brazil is one of the main silicon metal and iron-silicon producer in the world. But on the other hand, the amount of natural quartz that has been extracted for this purpose is up to 2 milliontons/year. The key-point is the large quantity of rejected quartz lascas, approximately 300,000 tons/year, generated during the various stages of extraction, crushing, selection, transportation, and washing. A new environrnentally mendly purification methodology denominated "quench-Ieaching" and "crush-leaching, that only uses aqueous leaching, has been developed. The result shows an effective elimination of major quartz impurities, such as Al, Fe, Na, K, Ca, Mn, ... , that transforms this rejected material into a 99.9% purity SI 'O IND 2'. The quality of this material is as high as the quartz powder commercially available in the intemational market for use as "fillers" and translucent silica glass raw material for semiconductor industries / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica

This undergraduate thesis – TCC, composed of a scientific article and an intervention product analyzes the occurrence of Burnout Syndrome dimensions and associations with factors that compose the coping strategies used by preceptors in an emergency hospital and emergency room of Maceió. The study consisted of a quantitative descriptive cross-sectional study. There was a non-probabilistic sample of 124 professionals from social service, nursing, medicine and psychology areas who, besides assistance to the users, play the role of preceptors within their routine activities. Descriptive statistics, chi-square test (χ²), analysis of variance (ANOVA) with post hoc tests, and r Pearson correlation analysis were used. We verified that 66.1% of the subjects (f = 82) work in more than one health institution, and have an average workload of 51.83 hours per week (SD = 15.08). Within coping strategies, the positive reassessment factor was the most prevalent for our sample, demonstrating an emotional focus to deal with the stressors in the environment. The positive reassessment factor was the most prevalent for the sample, demonstrating an emotional focus to deal with the environment stressors. The second factor evidenced was problem solving, more effective in the daily services. Regarding MBI, it was evidenced that the sample studied presented a mean score for the three dimensions of burnout: 60 (48.4%) emotional exhaustion, 57 (46.0%) depersonalization and 54 (43.5%) professional achievement. Burnout syndrome is personal and institutional; therefore, it is necessary that institutions rethink management forms, and provide more adequate working conditions to minimize agents causing stress and increase resources for the use of more appropriate coping strategies. After obtaining results, the intervention product aimed to promote actions meant to reduce stress levels created by daily work activities, preventing diseases and generating general welfare. An informative primer on burnout and suggestions for stress management was also made. / Este trabalho Acadêmico de Conclusão de Curso – TACC, composto por um artigo científico e um produto de intervenção, analisa qual a ocorrência das dimensões da síndrome de burnout, bem como as associações com os fatores que compõem as estratégias de coping utilizadas pelos preceptores em um hospital de urgência e emergência de Maceió. A pesquisa consiste em um estudo de delineamento descritivo transversal quantitativo. Conta-se com uma amostra por conveniência de 124 profissionais das áreas de serviço social, enfermagem, medicina e psicologia que, além da assistência aos usuários, exercem o papel de preceptores dentro de suas atividades de rotina. São utilizadas estatísticas descritivas; teste qui-quadrado (χ²); análise de variância (ANOVA) com testes post hoc; análise de correlação r Pearson. Verifica-se que 66,1% dos sujeitos (f=82) atuam em mais de uma instituição de saúde e possuem carga horária média de 51,83 horas semanais (DP=15,08). Dentro das estratégias de coping, o fator reavaliação positiva é o mais prevalente para a amostra, demonstrando um enfoque emocional para lidar com os estressores no ambiente. O segundo fator evidenciado é a resolução de problemas, mais eficaz no cotidiano dos serviços. Quanto ao MBI, evidencia-se que a amostra estudada apresenta escore médio para as três dimensões de burnout: 60 (48,4%) exaustão emocional, 57 (46,0%) despersonalização e 54 (43,5%) realização profissional. A síndrome de burnout é de ordem pessoal e institucional, portanto, faz-se necessário que as instituições repensem as formas de gestão, assim como proporcionem condições laborais mais adequadas, minimizando os agentes causadores de estresse e ampliando os recursos para utilização de estratégias de coping mais apropriadas. Após a obtenção dos resultados, o produto de intervenção tem como objetivo promover ações que visem à diminuição dos níveis de estresse gerados pelo cotidiano das atividades laborais, prevenindo doenças e gerando bem-estar geral. Também é formatada uma cartilha informativa sobre burnout e sugestões de administração do estresse.

Ao contrário da recomendação tradicional do treinamento de força, a proposta do método de pré-exaustão é iniciar a sessão de treino com exercícios monoarticulares e terminar com exercícios multiarticulares. O objetivo deste estudo foi, por meio da EMG, investigar parâmetros temporais e de intensidade da ativação dos músculos peitoral maior (PM), deltóide (DA) e tríceps braquial (TB) que possam fundamentar a aplicação do método de pré-exaustão em 10RM dos exercícios supino e crucifixo. Foram comparados dois protocolos experimentais: P1) método da préexaustão; P2) recomendações tradicionais. A intensidade de ativação baseada no valor RMS, bem como a relação desta com a duração da contração muscular, estabelecida em faixas de intensidade, não obteve diferenças estatisticamente significativas para PM. Para DA, não houve diferenças estatisticamente significativas entre os protocolos na intensidade de ativação quando as repetições foram analisadas em conjunto. Entretanto, quando analisado cada repetição, este músculo apresentou aumento estatisticamente significativo de intensidade de ativação em P1, assim como maior solicitação da faixa de intensidade 80 a 100% CIVM. Para TB, a intensidade de ativação foi significativamente maior em P1 que em P2 para todas as formas de análise. Os resultados mostraram que o aparelho locomotor aumentou a dependência de TB como estratégia alternativa para tentar atingir 10RM do supino em P1. Assim, é possível afirmar que o método de pré-exaustão pode ser eficiente para impor maior estímulo neural sobre pequenos grupos acessórios na execução de um movimento e não sobre o grupo principal o qual se deseja. Entretanto, estes achados suportam que os efeitos do método de pré-exaustão ainda não podem ser afirmados categoricamente. Pois, ao longo da série em P1 não houve aumento significativo na intensidade de ativação de um mesmo músculo, bem como das faixas de intensidade, como houve em P2. Desse modo, é possível afirmar que os músculos, em P1, iniciaram a série em um nível de intensidade mais alto que em P2, pois foram estimulados previamente / Contrariwise the strength training traditional recommendation, the preexhaustion method purposes to begin a training session with monoarticular exercises and to finish it with multiarticular exercises. The aim of this study was, through EMG, to inquire into temporal and activation intensity parameters of pectoralis major (PM), deltoid (DA) and triceps brachii (TB) muscles, which can be used as a basis to bench press and flying 10RM pre-exhaustion method application. It was compared two experimental protocols: P1) pre-exhaustion method; P2) traditional recommendation. The activation intensity, as well its relationship with the muscular contraction duration, established on intensity levels, did not attain significant differences to PM. To DA, there were not differences between the protocols respecting the activation intensity when whole the repetitions were analyzed. However, when each repetition was analyzed, this muscle exhibited significant increasing in activation intensity in P1; as well it showed a more intense solicitation of 80 to 100% MVIC level. To TB, the activation intensity was significant greater in P1 than P2 respecting whole manners to data analysis. The results exhibited that the locomotor apparatus increased the TB dependence as an alternative strategy to try to attain bench press 10RM in P1. Therefore, it is possible to assert that pre-exhaustion method may be efficient to impose largest neural stimuli on small synergists muscular groups during movement execution, but not on the main target muscular group. However, these findings sustain that the pre-exhaustion method effects cannot receive a categorical affirmation, yet. Because, contrariwise the P2, during the P1 bench press set there was not significant increasing in the same muscle activation intensity, as well in the intensity levels. This way, it is possible to assert that, in P1 the muscles began the set in a highest intensity levels than in P2, because they were stimulated previously

Objetivo. En este estudio se buscó determinar la relación que existe entre la autoeficacia académica y el cansancio emocional en estudiantes de secundaria de Lima; así como determinar si existen diferencias entre ambas variables según el género y grado académico. Método. Se utilizó un diseño no experimental, de tipo transversal y de alcance correlacional. La muestra estuvo compuesta por 168 escolares entre 11 a 18 años, se obtuvo por medio de un muestreo no probabilístico por conveniencia. Se emplearon la Escala de Autoeficacia Percibida Específica de Situaciones Académicas versión Domínguez, Villegas, Yauri, Mattos y Ramírez y la Escala de Cansancio Emocional adaptada por Domínguez. Resultados. Se determinó la existencia de una correlación negativa entre ambas variables, cuya magnitud de correlación fue pequeña. Asimismo, en los análisis comparativos, no se encontraron diferencias estadísticamente significativas entre ambas variables según género (p > 0.050) y grado académico (p > 0.050). Conclusión. Existe correlación negativa entre la autoeficacia académica y el cansancio emocional. Esto significa que, a mayor nivel de autoeficacia académica, existirá un menor grado de cansancio emocional (r = - 0.238, p < 0.050). / Objective. This study sought to determine the relationship between academic self-efficacy and emotional exhaustion in secondary school students from Lima; as well as to determine the differences that exist between both variables according to gender and academic degree. Method. A non-experimental, cross-sectional and correlational design was used. The sample consisted of 168 schoolchildren between 11 and 18 years old, it was obtained through a non-probabilistic convenience sampling. The Domínguez, Villegas, Yauri, Mattos and Ramírez version of the Scale of Perceived Self-Efficacy Specific to Academic Situations and the Scale of Emotional Tiredness adapted by Domínguez were used. Results. The existence of a negative correlation between both variables was determined, whose magnitude of correlation was small. Likewise, in the comparative analyzes, no statistically significant differences were found between both variables according to gender (p> 0.050) and academic degree (p> 0.050). Conclution. There is a negative correlation between academic self-efficacy and emotional exhaustion. This means that, at a higher level of academic self-efficacy, there will be a lower degree of emotional fatigue (r = - 0.238, p <0.050) / Tesis

Tuberculosis (TB), a transmissible disease caused by Mycobacterium tuberculosis (Mtb), is a global health threat. To design an effective vaccine, we need to better understand how different elements of our immune system collaborate to fight against Mtb. CD4 T cells are crucial in protective immunity to Mtb because they produce cytokines including interferon-γ. In contrast, CD8 T cells are thought to play a modest role. Whether CD4 T cells act as “helper” cells to promote optimal CD8 T cell responses during TB is unknown. We argue CD8 T cells’ role are likely underestimated because CD8 T cell functions are compromised without CD4 T cells. Here, using two independent models, I show that CD4 T cell help promotes CD8 T cell effector functions and prevents CD8 T cell exhaustion. I demonstrate CD4 and CD8 T cells synergistically enhance the survival of infected mice. Purified helped, but not helpless, CD8 T cells effectively restrict intracellular Mtb growth. Thus, CD4 T cell help is indispensable for generating protective CD8 T cell responses. In addition, I investigate the mechanisms of CD4 T cell help. Signals from CD4 T cells, and signals relayed by antigen presenting cells collectively shape CD8 T cell responses. We infer that vaccines aimed for eliciting both CD4 and CD8 T cells, in which CD8 T cells are properly helped by CD4 T cells, are more likely to be successful.

The purpose of this study is to examine how supervisors within individual and family care handle the area for burnout among social workers. The study also examined supervisors view on the psychosocial environment and its significance for burn-out. In this qualitative study, interviews were conducted with 7 professionals supervisor. The result show that supervisors within individual and family care have experience of burn-out among social workers. All informants point out that the occurrence of burn-out looks different for different individuals who are affected. The result also show, based on the informant’s responses, that the psychosocial work environment in the workplace has a connection with the mental illness of the employee and that in combination with each other, affect the individual's well-being. The majority of informants illustrate various challenges regarding these areas, including privacy life versus professional life in the occurrence of burn-out. The result of the study show that there is a need for more research on the subject. / Syftet med denna studie är att undersöka hur chefer inom individ- och familjeomsorg hanterar området för utmattningssyndrom bland socialsekreterare. Studien undersökte även chefers syn på den psykosociala arbetsmiljön och dess betydelse för utmattningssyndrom på arbetsplatsen. Till studien valdes en kvalitativ ansats där sju stycken yrkesverksamma chefer intervjuades. Resultatet visar att chefer inom individ-och familjeomsorg har erfarenheter av utmattningssyndrom bland socialsekreterare. Samtliga informanter pekar på att uppkomsten av utmattningssyndrom ser olika ut för olika individer som drabbas. Resultatet visar också, utifrån informanternas upplevelser, att den psykosociala arbetsmiljön på arbetsplatsen har ett samband med psykisk ohälsa hos medarbetaren och att dessa i kombination med varandra påverkar individens mående. Majoriteten av informanterna belyser olika utmaningar gällande dessa områden, däribland privatliv kontra yrkesliv i uppkomsten av utmattningssyndrom. Resultatet av studien visar att det finns ett behov av mer forskning kring ämnet.

[pt] Em todos os sistemas de potência, inclusive o brasileiro, verificam-se os níveis de tensão nos barramentos e de corrente nos ramos de transmissão na presença de contingências durante a operação em tempo real. A lista de contingências inclui a perda de qualquer ramo de transmissão, a perda de alguns pares de ramos e, de menor importância, a perda de geração. As condições de estabilidade de tensão também são checadas nesse momento. Esse trabalho simula eventos em que há perda do controle de tensão devido ao esgotamento da fonte controladora em todas as barras de tensão controlada da rede e verifica seus efeitos sobre a estabilidade de tensão. As simulações realizadas incluem também o evento em que há perda de capacidade de aumentar a geração de potência ativa em todos os geradores. Um método de ordenação pelo grau de severidade do evento sobre a estabilidade de tensão é empregado. Além disso, aproveitam-se os resultados obtidos e determinam-se as tensões e gerações mais influentes sobre a estabilidade de tensão de uma certa barra. Com a finalidade de aumentar a margem de potência dessa certa barra, calculam-se ações de controle preventivas, isto é variações nas tensões e, se necessário, nas gerações ativas. / [en] In all power systems, including the Brazilian one, it is common to check the voltage levels in busbars and current in the transmission branches in presence of contingencies during the real-time operation. The list of contingencies includes loss of any transmission lines, loss of some pairs of branches and, less importantly, loss of power generation. Voltage stability conditions are also checked at that time. This work simulates events in which there is loss of voltage control due to the exhaustion of the control source in all voltage-controlled busbars and verifies its effects on voltage stability. Simulations also include the event which shows loss of capacity to increase the active power generation in all generators. A ranking method is employed to order events by their degree of severity over voltage stability. In addition, the obtained results are used to determine the most influential voltages and generators over the voltage stability of a specific busbar. In order to increase the margin of power of this certain busbar, preventive control actions are calculated by keeping track of variations in voltage and, when necessary, in active power generations.

Bakgrund: Det har påvisats att brister i den organisatoriska och sociala arbetsmiljön kan ge upphov till psykisk ohälsa och att grundskollärare är särskilt utsatta gällande höga krav och låg kontroll i arbetet. Tidigare studier har visat på att höga krav är en stor riskfaktor för att stressrelaterade psykiska besvär kan uppkomma i den organisatoriska och sociala arbetsmiljön. Vidare ses att obalans mellan arbete och privatliv kan påverka den psykiska hälsan negativt och att grundskollärares arbetsuppgifter kan påverka balansen mellan arbete och privatliv. Syfte: Syftet med studien var att undersöka om det finns något samband mellan utmattning bland grundskollärare och deras organisatoriska och sociala arbetsmiljö samt den balans mellan arbete och privatliv de beskriver. Metod: Studien var kvantitativ med en tvärsnittsdesign och bekvämlighetsurval som bestod av grundskollärare. Ett elektroniskt frågeformulär baserat på Copenhagen Psychosocial Questionnaire Version III användes för att samla in data som genererade 85 ifyllda frågeformulär. Korrelationsanalys, bivariata och multipla regressionsanalyser samt oberoende t-test användes som analysmetoder i SPSS. Resultat: Resultatet från den multipla regressionsanalysen indikerade en statistisk signifikant association mellan utmattning och obalans mellan arbete och privatliv (β= ,601, SE= ,072, P&lt; ,001). Signifikanta samband identifierades i bivariata regressionsanalyser för krav och kontroll i arbetet och utmattning. De oberoende t-testen påvisade signifikanta skillnader för utmattning där de respondenter som upplevde en hög obalans mellan arbete och privatliv upplevde högre utmattning jämfört med de som upplevde låg obalans oberoende av vilken grad av krav och kontroll som upplevdes. Slutsats: Faktorer i den organisatoriska och sociala arbetsmiljön påverkar utmattningsgraden negativt. Då detta är en tvärsnittsstudie går det inte att dra några kausala samband och mer forskning med longitudinella studier med större population och ett obundet slumpmässigt urval krävs för att säkerställa dessa resultat. / Aim: The aim of the study was to investigate whether there is any association between exhaustion among primary school teachers and their psychosocial work environment as well as the work-life balance they describe. Method: The study employed a cross-sectional design and an electronic questionnaire, based on Copenhagen Psychosocial Questionnaire Version III, was used to collect the data which generated 85 completed questionnaires. The data was analyzed with correlations analysis, linear regression analysis, and t-test. Results: The result indicated a statistically significant association between exhaustion and work-life imbalance (P&lt; .001). The degree of exhaustion was significant higher for those who experienced a high work-life imbalance compared with those who experienced a low imbalance regardless of the degree of demand and control in work. Conclusion: The psychosocial work environment affects the degree of exhaustion. As this is a cross-sectional study, it is not possible to draw any causal relationships and more research with longitudinal studies with random sample and larger populations is required to ensure these results.