To make energy production sustainable and reduce carbon dioxide emissions it is necessary to stop using fossil fuels as our primary energy source. The Accelerator Driven Subcritical Reactor (ADSR) could provide safe nuclear power. It uses thorium as fuel, which is more abundant than uranium, and produces less long lived waste. An ADSR uses neutron spallation, caused by a high power proton beam impacting a metal target, to drive and control the reaction. The beam needs to have an energy of around 1 Ge V and a current of 10 mA with a very high reliability, the combination of which is beyond the capabilities of existing particle accelerators. Cyclotrons and synchrotrons both have trouble producing such a beam, while a suitable linac would be several hundred metres long, and expensive. A more compact accelerator design would allow multiple accelerators to be combined to improve reliability. This thesis examines the use of a Fixed-Field Alternating-Gradient (FFAG) accelerator as the proton driver. FFAGs are compact, and can simultaneously achieve higher energies than a cyclotron at higher repetition rates than a synchrotron. However, it is still a challenge to reach the high currents required. A 35 to 400 MeV non-scaling FFAG was designed to demonstrate issues encountered at high currents. Two methods were investigated in order to increase the number of particle bunches that could be simultaneously accelerated. One uses multiple solutions to the harmonic conditions for acceleration, and the second injects bunches after the acceleration has started. Neither was found to give significant practical improvement in current. Space charge is a destructive force at high currents. Software was developed to simulate the effect of space charge in an FFAG using several models. Space charge tune shifts were measured for a range of energies and currents, and peak currents of above 1 A were found to be unstable. In order to provide 10 mA of average current, acceleration would need to occur in around 100 turns, which will require a very rapid RF sweep.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-12T12:12:32Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Mestrado_JulianaScanoni_Corrigido_19.11.pdf: 2056204 bytes, checksum: 8a5314fcf4ab820bdedd049620355c53 (MD5) / Made available in DSpace on 2016-04-12T12:12:32Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Mestrado_JulianaScanoni_Corrigido_19.11.pdf: 2056204 bytes, checksum: 8a5314fcf4ab820bdedd049620355c53 (MD5) Previous issue date: 2015-07-28 / CAPEs / Hidrocarbonetos policíclicos aromáticos (HPAs) são compostos derivados de petróleo conhecidos por seu potencial de toxicidade a organismos aquáticos. Regiões estuarinas são frequentemente contaminadas por HPAs em decorrência de processos de urbanização e atividades industriais, incluindo a cadeia produtiva do petróleo. O trabalho teve o objetivo de avaliar a bioconcentração e efeitos bioquímicos de HPAs em Eugerres brasilianus coletados em quatro estuários no litoral sul de Pernambuco, a fim de obter um diagnóstico da poluição por estes contaminantes nestas regiões. As coletas foram realizadas no rio Ariquindá, sistema estuarino do rio Formoso (AR-SERF), no rio Massangana, no complexo estuarino de Suape (MA-CES), no sistema estuarino de Barra de Jangada (SEBJ), e no complexo estuarino da bacia do Pina (CEBP). A bile dos peixes foi analisada por Fluorescência Fixa para estimar a concentração em equivalentes dos HPAs naftaleno, fenantreno e criseno. Amostras de fígado foram utilizadas para análise de biomarcadores enzimáticos de fase I (etoxiresorufina orto-deetilase, EROD), fase II (glutationa S-transferase, GST), e defesa antioxidante (catalase, CAT, e glutationa redutase, GR). A análise de HPAs na bile e atividades enzimáticas em peixes coletados num ciclo anual em MA-CES e AR-SERF indicou uma semelhança na contaminação por HPAs na bile e nos níveis de atividades enzimáticas dos biomarcadores avaliados entre estes estuários, apesar da diferença do padrão de atividades antrópicas destas regiões. O CES comporta um complexo portuário com alta atividade industrial enquanto o SERF possui baixa densidade populacional e atividades turísticas. Os peixes coletados em SEBJ e CEBP apresentaram bile com concentrações do HPA criseno entre 13 x e 19 x maiores que AR-SERF, respectivamente. Foi detectado aumento das atividades da EROD, GST e CAT das regiões do SEBJ e CEBP, chegando a 30 x para a EROD, e aproximadamente 2 x para GST e CAT em comparação com AR-SERF. A maior bioconcentração de HPAs na bile e maior indução enzimática nos peixes E. brasilianus do SEBJ e CEBP indicam que estes estão dispendendo energia para tentar se adaptar a esta contaminação, o que pode ter consequências para o seu crescimento e sobrevivência nestas regiões. Os resultados indicam que SEBJ e CEBP recebem um maior aporte de HPAs, associado a maior densidade populacional e atividades antrópicas nas bacias desses rios. Os parâmetros utilizados serão úteis para o monitoramento destes sistemas estuarinos, em especial do CES, em franco processo de urbanização e industrialização. / Polycyclic aromatic hydrocarbons (PAHs) are oil derived compounds known for their toxicity potential towards aquatic organisms. Estuarine regions are frequently contaminated with PAHs as a result of urbanization processes and industrial activities, including the oil productive chain. The work aimed to evaluate the bioconcentration and the biochemical effects of PAHs in Eugerres brasilianus sampled from four estuaries in the south coast of Pernambuco, in order to obtain a pollution diagnosis by these contaminants in such regions. The data collection was made in the Aquirindá river, Rio Formoso estuarine system (AR-RFES), in the Massangana river, in the Suape’s estuarine complex (MA-SEC), in the Barra de Jangada estuarine system (BJES) and in the Bacia do Pina estuarine complex (BPEC). The fish’s bile were analyzed using fixed fluorescence to estimate the equivalent concentrations of the PAHs naphthalene, phenanthrene and chrysene. Liver samples were used for phase 1 enzymatic biomarkers analysis (Ethoxyresorufin-O-deethylase, EROD), phase II (glutathione S-transferase, GST) and antioxidant defense (catalase, CAT, and glutathione reductase, GR). The analyzes of PAHs in bile and enzymatic activity in fish that were sampled in an annual cycle in MA-SEC and AR-RFES indicated a similarity between PAHs contamination in bile and the enzymatic activity levels of the biomarkers evaluated among these estuaries, despite the different anthropogenic activity patterns. The SEC comprises a port complex with high industrial activity, while the RFES has low population density and touristic activities. The bile of the fish sampled in BJES and BPEC showed chrysene concentration between 13 x and 19 x higher than AR-RFEC, respectively. An increase in EROD, GST and CAT activities was detected in the regions of BJES and BPEC, reaching 30 x for EROD, and approximately 2 x for GST and CAT. The high PAHs bioconcentration in the bile and the high enzymatic induction in E. brasilianus fish from BJES and BPEC indicate that these fish are wasting energy to try to become adapted to this contamination, which may have consequences to their growth and survival in such regions. The results indicate that BJES and BPEC receive a greater input of PAHs, associated with the higher population density and anthropogenic activities in these rivers’ basins. The parameters used will be useful for the monitoring of these estuarine systems, especially in SEC, which suffers with a rapid urbanization and industrialization process.

Orientador: Maximiliano Piero Neisser / Banca: Mauro Antonio de Arruda Nóbilo / Banca: Marco Antonio Bottino / Resumo : Próteses sobre implantes osseointegrados requerem critério de fabricação preciso devido a ausência de tecidos periodontais que compensam erros menores de relacionamento. Para tanto, em um arco mandibular edêntulo, construído em aço-cromo, foram fixados cinco análogos de pilares de implante, paralelos entre si, com distância de 10mm medidos de centro a centro. Sobre estes foram parafusados novos cilindros de ouro, com torque de 10 N/cm. Então foram executadas 15 sobre-estruturas metálicas que foram divididas: GC - Adaptação passiva dos cilindros de ouro; GM - monobloco GB - segmentos soldados por brasagem e, GL - segmentos soldados a laser. Observou-se as estruturas parafusadas com parafusos sempre novos sob microscópio de mensuração. A medição foi realizada na vestibular e lingual da interface cilindro/análogo e dados anotados em tabela apropriada. Para o eixo y, a técnica de soldagem a laser (Media=12,41 e Dp=11,12) produziu menos distorção significativamente do que a técnica de brasagem (Media=23,06 e Dp=13,31) seguida pela técnica de monobloco (Media=39,83 e Dp=21,88) p= 0.05. Para o eixo x, somente o grupo Monobloco apresentou diferença significativa para as demais técnicas (Média= 45,66 e Dp=21,56) / Abstract: Prosthesis above osseointegrated implants requires an accurate criterion of manufacture. So, in an edentulous mandibular arch, constructed with "chromium steel", five analogous were fixed, parallels, with distance of 10 mm measured of center to center. Above these gold cylinders were positioned and screwed with a torque of 10 N/m. In the next follow, fifteen over structures were fabricated and divided in tour groups: CG - Passive adaptation of gold cylinders; MG - Monobloc casting; BG - Casting in segments after brasing; LG - Casting in segments after laser welding. The structures were observed with measures microscope and the data noted in specific table. The measures done in two points (left and right) in the buccal and lingual surfaces of the interface of the cylinder/analogous set in the x and y-axis. The statistics analysis (ANOVA) showed significant statistics differences, on y-axis, among groups: LG group was superior to BG and this was superior to MG group and on x-axis only MG was superior to others groups (when we studied distortion.) / Mestre

Orientador: Wilkens Aurelio Buarque e Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T15:52:29Z (GMT). No. of bitstreams: 1 Figueiredo_LuizaAlencardeAndrade_M.pdf: 1625885 bytes, checksum: 947b4b13192c70f6a518b45baa1cd8cf (MD5) Previous issue date: 2015 / Resumo: O objetivo desse trabalho foi avaliar por meio da técnica extensometria linear elétrica as deformações ocorridas nas réplicas de implantes e nas infraestruturas metálicas de próteses parciais fixas envolvendo o espaço protético dos quatro incisivos superiores com variação na disposição dos análogos e na configuração protética. Foram confeccionadas duas infraestruturas: corpo de prova I, com análogos instalados na posição correspondente aos incisivos laterais e infraestrutura com pôntico na região dos incisivos centrais e, corpo de prova II com análogos posicionados nos incisivos centrais e infraestrutura com cantilever na região dos incisivos laterais. Os extensômetros foram posicionados nas regiões cérvico-vestibular e cérvico-palatina dos análogos e cervical das infraestruturas. Os corpos de prova foram submetidos a carga progressiva de 150N a uma angulação de 45° na superfície palatina do incisivo lateral esquerdo superior, simulando uma oclusão funcional. Como resultados, foi observado que todos os extensômetros registraram deformação com característica de compressão ou tração. As deformações nos análogos foram significativamente diferentes das infraestruturas (p<0,05 ou p<0,01). Em ambos corpos de prova, maiores valores de deformação foram exibidos na região vestibular dos análogos. Não houve diferença significativa entre os extensômetros fixos na mesma posição (análogos e infraestruturas), quando os dois corpos de prova foram comparados. O corpo de prova II apresentou maiores valores de deformação. Pode-se concluir que próteses parciais fixas com extensão em cantilever apresentaram as maiores deformações e o posicionamento dos implantes e desenho protético influenciam na distribuição de tensão e deformação nos componentes do sistema. / Abstract: The aim of this study was to evaluate by means of strain gauges the deformations in metal samples of implants and framework of FPDs involving the four upper incisors of different analogues positions. Thus, two samples were made: framework I with the analogues in the position of the lateral incisors and the pontic in the central incisors; framework II with the analogues in the central incisors and the cantilever in the lateral incisors. The strain gauges were positioned in the analogues on the superior buccal and palatine surfaces. In the framework the strain gauges were fixed in superior surface. The samples received a load of 150 N, at 45 angle, on the palatine surface of the incisor left side, simulating the functional occlusion. The results showed the deformations with compression and traction characteristics. The deformations in the analogues were significantly different from those in framework (p <0.05 or p <0.01). In both samples the highest deformations values were presented in the buccal areas of the analogues. The strain gauges positioned in the same local (analogues and framework) when compared the two samples there were no significant difference. However, the sample II showed the highest deformations values. It was concluded that the fixed partial dentures with cantilever extension showed highest deformation and the positioning of the implants and prosthetic design influence the stress distribution and deformation in the components / Mestrado / Protese Dental / Mestra em Clínica Odontológica

Nos últimos anos, o value-at-risk tem se tornado uma ferramenta amplamente utilizada nas principais instituições financeiras, inclusive no Brasil. Dentre suas vantagens, destaca-se a possibilidade de se resumir em um único número os riscos de mercado incorridos e incorporar neste valor tanto a exposição da instituição quanto a volatilidade do mercado. O objetivo principal deste estudo é verificar a eficácia dos modelos mais conhecidos de value-at-risk - RiskMetrics(TM) e Simulação Histórica - na mensuração dos riscos de mercado de carteiras de renda fixa compostas por instrumentos pré-fixados em reais. No âmbito da alocação de capital para atendimento aos órgãos de regulamentação, o estudo estende-se também ao modelo adotado pelo Banco Central do Brasil. No decorrer do estudo, discute-se ainda as vantagens e desvantagens apresentadas, bem como o impacto que as peculiaridades do mercado brasileiro exercem sobre as hipóteses assumidas em cada um dos modelos. / Value-at-Risk (VaR) has become the primary tool for the systematic measuring and monitoring of market risk in most financial institutions. VaR is a statistical measure that comprises not only the exposure but also the market volatility in a single number. The main purpose of this work is to evaluate the performance of the well-known value-at-risk models - RiskMetrics(TM) and Historical Simulation - in the Brazilian fixed-income market. In the scope of capital allocation related to banking regulation, this study also extends briefly to the model adopted by the Brazilian Central Bank. Additionally, the underlying assumptions of these models are analyzed in the Brazilian financial market context. Also, this study discusses the advantages and disadvantages presented by the RiskMetrics and the Historical Simulation models.

Suicide is social tragedy that devastates families and is very costly for society. Even though suicide have been a known social problem for over a century society have yet to solve it. The purpose of this essay is to examine whether the socio-economic theory can explain the variance of suicide rate in Sweden. From previous studies and socioeconomic theories, the variables unemployment, divorce rate, fertility was picked because of their ability to explain the variance of suicides rates. Population density was also picked because of its close relation with social isolation. A two-way fixed- effect model controlling for region and time was employed on a panel of 21 counties over the years 2005-2017. The results of the regression were that all independent variables, but population density were insignificant. The study concludes that the panel employed are not enough to determine whether the socio-economic factors can explain the variance of suicide rates in Sweden. / Självmord är en social tragedi som ödelägger familjer och är en stor kostnad för samhället. Även om självmord har varit ett känt problem i århundraden så är det fortfarande ett olöst problem. Syftet med den här uppsatsen är att undersöka om socioekonomisk teori kan användas för att förklara variansen av självmord i Sverige. Från tidigare studier och socioekonomiska teorier utrönandes tre variabler som anses kunna förklara variansen av självmord. De tre variablerna var arbetslöshet, skilsmässor och fertilitet. Befolkningstäthet lades till i regressionen, eftersom den ansågs vara i relaterad till sociologiska teorier. En tvåvägs fasteffekt regression som kontrollerar för län- och tid effekter applicerades på en panel bestående av 21 län under åren 2005–2017. Resultatet av regression visade att alla variabler förutom befolkningstäthet var icke signifikanta. Studien konkluderar att panelen som analyserats inte är tillräckligt för bedöma om socioekonomiska teorier kan förklara variansen av självmord.

The purpose of this study was to examine general education teachers' knowledge and experiences regarding a growth versus a fixed mindset while teaching students with disabilities in Grades K-2. The conceptual framework that was used to guide this study was Dweck's implicit theories of mindsets. Research questions were developed to explore teachers' knowledge and experiences about teaching with a growth mindset versus fixed mindset and how they assessed themselves in terms of teaching with a fixed or growth mindset. The research design was a basic qualitative study that included semi structured interviews and a teacher assessment using a Mindset Quiz. A convenience sampling method was used to recruit 10 general education teachers at a northeastern U.S. elementary school. Data were analyzed through open coding and thematic analysis. The following themes were identified: all participants received no training on how to teach with a growth mindset versus a fixed mindset, all participants were interested in attending professional development on this topic, there was some knowledge of the terms growth versus fixed mindset, and all participants use some type of strategy to help improve student mindsets. The results of this study contribute to positive social change by making educators and administrators more aware of fixed versus growth mindset strategies used in classrooms. This study may bring attention to the concept of mindsets and make educators aware of the need to promote growth mindsets. Additionally, results support the need for professional development for teaching with a growth mindset for students with disabilities. Increased teacher understanding of teaching with growth mindsets can lead to better learning experiences for students in the classroom.

This work begins with an introduction to catalysis focusing on heterogeneous systems and surface science phenomena. A study on the partial oxidation reaction of n-butane to maleic anhydride (MA) is presented in the first part. MA supplies are barely adequate for market requirements due to continued strong demand. Only slight improvement in catalytic performance would be welcome in the industrial community. The vanadium phosphorus oxide (VPO) catalyst was used in this work. The reaction is highly exothermic and the need to properly support the catalyst, not only for good dispersion but adequate heat dissipation is of crucial importance. For this, alpha-SiC commercial powders were used in synthesizing the catalyst due to its high thermal conductivity. Up to 25% MA yields were obtained and the reaction temperature was lowered by up to 28% using SiC/VPO mixed catalysts. The second part of this work is focused on the Fischer-Tropsch synthesis (FTS) process using cobalt silica supported catalysts. The main objective is the production of synthetic ultra high purity jet fuel (JP5). This is a very timely topic given the energy issues our world is facing. Almost all aspects of the FTS process have been extensively studied, however the effects of calcination temperature and silica support structure on the catalyst performance are lacking in literature. The catalysts were prepared using various silica supports. The catalysts had different drying and calcination temperatures. It was found that lower support surface area and calcination temperature catalysts exhibited higher activity due to lower support cobalt phase interaction. Co/silica catalysts calcined at 573K showed the highest CO conversion and the lowest CH4 selectivity. Catalysts prepared with 300m²/g support surface area exhibited 79.5% C5+ selectivity due to higher reducibility and less metal support interaction. The properties and performance of various prepared catalysts in both VPO and Co/silica systems are characterized by FTIR, XRD, BET, GC and XPS techniques. Theoretical FTS deactivation by sintering calculations and SiC/VPO particle temperature gradient calculations are presented as well. Finally, conclusions and future work on improving the yield and selectivity and scaling up the bench top setups are also presented.

Sedan 2010 kan en friskola överklaga kommunens beslut om skolpeng ifall den anser att lika villkor inte har uppnåtts. Reformen har lett till att tusentals konflikter mellan friskolor och kommuner har tagits till domstol. I denna studie kartläggs och beskrivs de konflikter som rör kompensation till friskolor för kommunala underskott. Därtill prövas hypoteser om samband mellan politisk ideologi, kommunstorlek, nivå på skolpeng respektive andel friskolor och konflikt genom regressioner av paneldata.Resultaten visar substantiella samband mellan vänsterstyre, en hög andel friskolor respektive kommunstorlek och ökad sannolikhet för konflikt. Därtill visar kartläggningen att Sveriges största friskolekoncern är överrepresenterad i konflikterna. Det indikerar att reformen – vars syfte var att stärka friskolornas roll i bidragsprocessen – i första hand stärkt stora aktörer.

Air pollution (in terms of PM2.5) is severe in developing countries, and the rapid population growth accompanied by urbanization may limit their potential economic development. This paper aims to investigate if urbanization and economic freedom cause higher levels of PM2.5 in developing countries. By measuring the potential effect of economic freedom on PM2.5 with the Ease of Doing Business-score by the World Bank, a new measure is introduced to the research on socioeconomic factors’ influence on air pollution. It is done by running both fixed effects- and system GMM regressions on a panel consisting of 63 low- and lower-middle-income economies between 2010-2017. The results indicate that PM2.5 is insensitive to changes in both variables and that urbanization’s effect on PM2.5 depends on the level of economic freedom and vice versa. However, both estimators may suffer from bias, and thus, the real relationship of urbanization and economic freedom on PM2.5 remains uncertain.