Les dispositifs intersousbandes à base de nitrures d’éléments III ont des propriétés très intéressantes pour l’optoélectronique et la photonique dans l’infrarouge. Les hétérostructures formées par l’AlN et le GaN ont une discontinuité de potentiel en bande de conduction de 1.75 eV et permettent donc de couvrir les deux extrémités du spectre électromagnétique infrarouge. Ces matériaux sont en outre caractérisés par des temps de relaxation ISB extrêmement courts et sont par conséquent des candidats potentiels pour le développement de composants optoélectroniques ultrarapides aux longueurs d’onde des télécommunications. D’autre part, grâce à l’énergie du phonon LO élevée dans ces matériaux, ces hétérostructures ouvrent la voie vers la réalisation de lasers à cascade quantique THz fonctionnant à la température ambiante. Dans ce contexte, je présente dans une première partie de ma thèse une étude théorique et expérimentale du transport électronique dans des hétérostructures GaN/Al(Ga)N simples comme les diodes tunnel résonnantes (DTRs) et plus complexes comme les multi-puits quantiques. La modélisation du transport quantique dans les DTRs AlGaN/GaN m’a permis de mettre en évidence la dépendance de résonance quantique du signe de la tension appliquée et de la composition des barrières. Du point de vue expérimental, je montre que le comportement électrique instable dans ces dispositifs est dû aux défauts dans le matériau. Dans les structures à multi-puits, je présente la première évidence expérimentale d’un transport tunnel résonnant reproductible. Dans une deuxième partie, je propose et développe plusieurs principes originaux de détecteurs à cascade quantique (QCD)s GaN/AlGaN entre 1 et 2 μm fonctionnant à la température ambiante. Je montre en utilisant des techniques de mesure de spectroscopie femtoseconde qu’ils sont intrinsèquement ultrarapides (picoseconde). Je développe aussi des micro-QCDs qui présentent une bande passante au-delà des 40 GHz. La conception des QCDs à plus grandes longueurs d’onde est discutée. Dans la dernière partie de ce manuscrit, je présente une étude spectroscopique dans le THz de superréseaux à base de GaN. Je montre que l’utilisation de puits quantiques à marche de potentiel permet d’accorder l’absorption ISB dans le THz. Je présente ensuite la première démonstration de l’électroluminescence intersousbande de 2 à 9 THz. / Intersubband devices based on III-nitrides have interesting properties for optoelectronics and photonics applications in the infrared. The heterostructures of these materials have a large conduction band offset of 1.75 eV and therefore allow covering the whole infrared electromagnetic spectral range. Furthermore, these materials are characterized by extremely short ISB relaxation times and are, consequently, potential candidates for the development of ultrafast optoelectronic devices at the fiber optics telecommunication wavelengths for fiber optics or for free space communication. On the other hand, thanks to the large LO phonon energy in these materials, these heterostructures offer the possibility of fabricating compact THz lasers operating at room temperature. In this context, I firstly present in this manuscript a theoretical and an experimental study of the electronic transport in simple AlGaN/GaN heterostructures namely resonant tunneling diodes and more complex structures such as multi-quantum wells based on III-nitrides. The modeling of the transport in RTDs shows the dependency of the current resonances on the sign of the applied voltage as well as the height of the double barrier. I also demonstrate that the experimentally observed electrical instabilities in these devices are due to the defects in the material. In the multiple quantum well structures, I give the first evidence of reproducible resonant tunneling transport. In chapter 3, I propose and develop several principles of quantum cascade detectors in the near infrared between 1 and 2 μm operating at room temperature. I demonstrate, using time-resolved bias-lead monitoring technique, that they are intrinsically very fast (picosecond). I also develop micro - QCD devices that have a -3 dB cut-off frequency beyond 40 GHz. The design of QCDs operating at longer wavelengths is discussed. In the last part of the manuscript, I present a spectroscopic study of GaN superlattices with ISB transitions in the far-infrared. I show that the utilization of step quantum wells allows to tune the ISB absorption frequency to the THz. I finally present the first demonstration of the intersubband electroluminescence from 2 to 9 THz in these structures.

A parte superficial do músculo masseter, subdividido em três regiões - superior, média e inferior - foi estudado por meio da eletromiografia de superfície em pacientes com maloclusão dental classe III de Angle. Participaram deste estudo 14 pacientes (4 do sexo masculino, 10 do sexo feminino, com idade de 7 a 12 anos). Utilizou-se o “scan" nº. 9 do eletromiógrafo modelo K6-I/EMG Eight Channel Surface Electromyograph (Myo-tronics Co., Seatle, WA, EUA). Empregou-se na análise estatística não-paramétrica o teste de Wilcoxon para a comparação entre os lados, e o teste de Friedman para a comparação entre as regiões. Concluiu-se que: (1) nos movimentos de Abertura e Fechamento, Deglutição de Saliva, Oclusão Cêntrica Forçada e Mordida Molar Bilateral com Algodão, houve diferença estatística significante de atividade entre os lados, e o músculo masseter esquerdo apresentou maior atividade eletromiográfica que o músculo masseter direito; (2) a atividade da região superior predominou nas posições de Repouso e Repouso Pós-Exercícios, com diferença estatística significante, seguida pelas atividades das regiões média e inferior, respectivamente; (3) a atividade da região inferior predominou nos movimentos de Propulsão Livre, Deglutição de Água, Deglutição de Saliva e Desvio Lateral Esquerdo sem Contato, com diferença estatística significante, seguida pelas atividades das regiões média e superior, respectivamente; (4) a atividade da região inferior também foi predominante nos movimentos de Abaixamento Livre, Abertura e Fechamento, Abertura contra Resistência e Propulsão contra Resistência, com diferença estatística significante; e (5) a região média apresentou atividade intermediária às demais regiões nas posições de Repouso e Repouso Pós-Exercícios, e nos movimentos de Abertura e Fechamento, Abertura contra Resistência, Propulsão Livre, Deglutição de Água e de Saliva, e Desvio Lateral Esquerdo sem Contato, com diferença estatística significante. / The participation of superior, middle and inferior regions of superficial masseter was evaluated by surface electromyography of 14 patients, 04 male and 10 female, ranging in age from 7 to 12 years, with Angle’s class III dental malocclusion. The Scan #9 of the computerized program of K6-I/EMG Eight Channel Surface Electromyograph system (Myo-tronics Co., Seatle, WA, EUA) was employed with bipolar surface double electrodes. The non-parametric test of Wilcoxon was employed to the comparison between sides, and the non-parametric test of Friedman was employed to the comparison among regions. It was concluded that: (1) at the “opening and closing", “swallowing saliva", “centric occlusion" and “clenching with cotton rolls bilaterally at molar region", there was statistical differences between sides, and the left masseter developed more activity; (2) the superior region developed more activity with statistical differences at “rest" and “rest after exercises" positions, and was followed by the activity of middle and inferior regions, respectively; (3) the inferior region developed more activity with statistical differences at “free protraction of the jaw", “swallowing water", “swallowing saliva" and “lateral movement to the left side without occlusal contact", and was followed by the activity of middle and superior regions, respectively; (4) the inferior region developed more activity with statistical differences at “free opening", “opening and closing", “opening of the jaw against resistance" and “protraction of the jaw against resistance"; and (5) the middle region developed intermediary activity with statistical differences at “rest" and “resting after exercises", and at “opening and closing", “opening the jaw against resistance", “free protraction", “swallowing water", “swallowing saliva", and “lateral movement to the left side without occlusal contact".

Η ρόφηση Eu από υδατικά δ/τα των μικροοργανισμών Saccharomyces cerevisiae, Kluyveromyces marxianus και Debaromyces hansenii μελετήθηκε ως συνάρτηση της θερμοκρασίας ανάπτυξης, της παροχής αέρα κατά τη διάρκεια της ανάπτυξης και της ηλικίας των κυττάρων. Τα αποτελέσματα έδειξαν ότι η εκθετική φάση των κυττάρων και η βέλτιστη θερμοκρασία επιδρούν με τέτοιο τρόπο ώστε να έχουμε μεγαλύτερη ρόφηση μετάλλου, ενώ η παροχή αέρα δεν επηρεάζει σημαντικά τα αποτελέσματα της ρόφησης. / The Eu(III) uptake from aqueous solutions by Saccharomyces cerevisiae, Kluyveromyces marxianus and Debaromyces hansenii was studied as a function of the growth temperature, supply of air flow during the cultivation process and the age of cells. Our results revealed that exponential phase cells and the optimum temperature of growth resulted in a higher metal uptake, while aeration did not have any significant effect on the uptake.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Estatistica, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-09-19T15:39:17Z No. of bitstreams: 1 2016_AdélioHenriquedaSilvaNeto.pdf: 7022430 bytes, checksum: 482a6ceed2781b83bc70849b698e89db (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-09-19T16:16:23Z (GMT) No. of bitstreams: 1 2016_AdélioHenriquedaSilvaNeto.pdf: 7022430 bytes, checksum: 482a6ceed2781b83bc70849b698e89db (MD5) / Made available in DSpace on 2016-09-19T16:16:23Z (GMT). No. of bitstreams: 1 2016_AdélioHenriquedaSilvaNeto.pdf: 7022430 bytes, checksum: 482a6ceed2781b83bc70849b698e89db (MD5) / Na última década, diversos autores têm investigado novas famílias de distribuições de probabilidade com o intuito de obter modelos mais flexíveis para o ajuste a conjunto de dados. Neste trabalho, introduzimos pela primeira vez uma nova família de distribuições referida como a Gama tipo III Generalizada, que é uma generalização da família Gama tipo III (Torabi e Montazeri [6]). Estudamos duas distribuições particulares desta família: a Gama tipo III Burr III Generalizada (GIIIBIIIG) e a Gama tipo III Weibull Generalizada (GIIIWG). Fornecemos, também, uma descrição básica de algumas propriedades matemáticas e computacionais desta nova classe e destas novas distribuições. Para investigar o ajuste das novas distribuições foi analisado para cada modelo um conjunto de dados reais. ________________________________________________________________________________________________ ABSTRACT / In the last decade, several authors have studied new probability distribution families to obtain more flexible models. In this work, we introduce for the first time the Generalized Gama type III family of distributions wich is a generalization of gama type III family (Torabi and Montazeri [6]). We have studied two specific models of this family: Generalized Gama type III Burr III and Generalized Gama type III Weibull. We provide, also, a description of some of the mathematical and computational properties of this new class of distributions and the studied models. We fitted each model to a data set to investigate their flexibility.

A parte superficial do músculo masseter, subdividido em três regiões - superior, média e inferior - foi estudado por meio da eletromiografia de superfície em pacientes com maloclusão dental classe III de Angle. Participaram deste estudo 14 pacientes (4 do sexo masculino, 10 do sexo feminino, com idade de 7 a 12 anos). Utilizou-se o “scan” nº. 9 do eletromiógrafo modelo K6-I/EMG Eight Channel Surface Electromyograph (Myo-tronics Co., Seatle, WA, EUA). Empregou-se na análise estatística não-paramétrica o teste de Wilcoxon para a comparação entre os lados, e o teste de Friedman para a comparação entre as regiões. Concluiu-se que: (1) nos movimentos de Abertura e Fechamento, Deglutição de Saliva, Oclusão Cêntrica Forçada e Mordida Molar Bilateral com Algodão, houve diferença estatística significante de atividade entre os lados, e o músculo masseter esquerdo apresentou maior atividade eletromiográfica que o músculo masseter direito; (2) a atividade da região superior predominou nas posições de Repouso e Repouso Pós-Exercícios, com diferença estatística significante, seguida pelas atividades das regiões média e inferior, respectivamente; (3) a atividade da região inferior predominou nos movimentos de Propulsão Livre, Deglutição de Água, Deglutição de Saliva e Desvio Lateral Esquerdo sem Contato, com diferença estatística significante, seguida pelas atividades das regiões média e superior, respectivamente; (4) a atividade da região inferior também foi predominante nos movimentos de Abaixamento Livre, Abertura e Fechamento, Abertura contra Resistência e Propulsão contra Resistência, com diferença estatística significante; e (5) a região média apresentou atividade intermediária às demais regiões nas posições de Repouso e Repouso Pós-Exercícios, e nos movimentos de Abertura e Fechamento, Abertura contra Resistência, Propulsão Livre, Deglutição de Água e de Saliva, e Desvio Lateral Esquerdo sem Contato, com diferença estatística significante. / The participation of superior, middle and inferior regions of superficial masseter was evaluated by surface electromyography of 14 patients, 04 male and 10 female, ranging in age from 7 to 12 years, with Angle’s class III dental malocclusion. The Scan #9 of the computerized program of K6-I/EMG Eight Channel Surface Electromyograph system (Myo-tronics Co., Seatle, WA, EUA) was employed with bipolar surface double electrodes. The non-parametric test of Wilcoxon was employed to the comparison between sides, and the non-parametric test of Friedman was employed to the comparison among regions. It was concluded that: (1) at the “opening and closing”, “swallowing saliva”, “centric occlusion” and “clenching with cotton rolls bilaterally at molar region”, there was statistical differences between sides, and the left masseter developed more activity; (2) the superior region developed more activity with statistical differences at “rest” and “rest after exercises” positions, and was followed by the activity of middle and inferior regions, respectively; (3) the inferior region developed more activity with statistical differences at “free protraction of the jaw”, “swallowing water”, “swallowing saliva” and “lateral movement to the left side without occlusal contact”, and was followed by the activity of middle and superior regions, respectively; (4) the inferior region developed more activity with statistical differences at “free opening”, “opening and closing”, “opening of the jaw against resistance” and “protraction of the jaw against resistance”; and (5) the middle region developed intermediary activity with statistical differences at “rest” and “resting after exercises”, and at “opening and closing”, “opening the jaw against resistance”, “free protraction”, “swallowing water”, “swallowing saliva”, and “lateral movement to the left side without occlusal contact”.

A lack of efficient red luminecscent line emitters which exhibit a high absorption between 400 and 500 nm of the electromagnetical spectrum was the decisive factor to start this work. The invention of the blue LED (light emitting diode) enables the production of white light by combining the blue emitting LED with a yellow emitting phosphor. Advances in chip technology lead to high power LEDs with a power consumption of several watts. Long lifetimes (>50 000 working hours) and their high energy efficiency make them very interesting for the lighting market, but further problems have to be solved for the application in general lighting. A big issue for warm-white LEDs are colour rendering and colour temperature due to the lack of red parts in the spectrum. Another important feature of light sources is a stable colour over time. Therefore the applied converter material has to be chemically and photochemically stable. The chip-phosphor package is operated at working temperatures of about 150 to 200¡C Ð that also should not influence performance of the phosphor material. High absorption at the emission maximum of the LED and a high conversion efficiency (>90%) are important properties for designing a marketable converter material. In this work tungstates were studied due to their high chemical stability and their high alkaline character. Their use as a host lattice for lanthanide ions was investigated. LiLaW2O8 with 50 mol-% and La2W3O12 with 40 mol-% EuIII show the best performance in converting the blue light of the chip with quantum efficiencies of up to 90% at high absorption cross-setctions. Further investigations of temperature behaviour, long term durability under high photon fluxes and their conversion efficiency of the blue emitted to red converted light have to be done to allow a statement about their use in LED applications.

No description available.

The majority of matter in the Universe is dark. World wide efforts to understand this dark component of the Universe are underway and the current evidence suggests the existence of a non-relativistic, non-baryonic and weakly interacting massive particle (WIMP). This weakly interacting dark matter should occasionally couple to baryonic matter, primarily through nuclear interactions. The predicted event rates are low (< O(1) events/kg/day). The energy deposited is also expected to be low (<~ 50 keV), and so distinguishing a WIMP signal above the radioactive and cosmic backgrounds is a difficult challenge. The ZEPLIN{III device was designed to meet this challenge and achieve a competitive sensitivity to WIMP-nucleon interactions. The ZEPLIN{III detector is a two phase time projection chamber using liquid xenon as a target. The instrument was designed to detect dark matter by measuring scintillation and ionisation. Measuring two signals produced by incident radiation allows for discrimination between event types. This allows separation of the main component of the background radiation (primarily electron recoils) from any population of WIMP events that may be present in the data. The ZEPLIN-III detector completed its first science run in 2008, achieving a discrimination power of 1:7800 between nuclear and electron recoils, the highest of any liquid xenon detector. This result limited the WIMP-nucleon cross section to less than 8:4 X 10-8 pb at 90% confidence level (double sided) for a WIMP mass of 55 GeV/c2. The ZEPLIN-III detector then entered an upgrade phase. The two main improvements included the installation of a new ultra-low background PMT array, significantly reducing the main source of background events, and the addition of a veto detector. The veto detector significantly increased the detector's ability to reject WIMP-like background signals, which may be produced by background neutron events. The veto detector also aided background discrimination by detecting 28% of γ-ray events from the fiducial volume of ZEPLIN-III. The second science run of ZEPLIN-III began in June 2010 and continued until May 2011. During the second science run the discrimination power was 1:280 between nuclear and electron recoils. A total of 8 events were observed in the WIMP search region, which is consistent with background expectations. Assuming a null detection allowed the exclusion of the scalar cross-section above 4:8 10-8 pb near a WIMP mass of 51 GeV/c2. This result was combined with the result from a re-analysis of the first science run using more recent results for the relative scintillation yield, Leff, to give a total limit on the spin independent cross-section of 3:9 X 10-8 pb at 90% confidence near 52 GeV/c2 WIMP mass for the ZEPLIN-III experiment. The WIMP-neutron spin-dependent cross-section limit is 8:0 X 10-3 pb at 50 GeV/c2 at 90% confidence for the combined first and second science runs. At the time of publication, these were the world's second best, and best results, respectively.

Avaliou-se clinicamente 2 resinas compostas (Z-100 e Fill Magic),quanto a: sensibilidade pós-operatória, forma anatômica, cárie secundária, integridade marginal, descoloração marginal, cor e a influência do período de observação (“baseline", 6 meses, 1 ano e 2 anos) no desempenho desses fatores. Participaram 43 pacientes, que receberam 2 restaurações de classe III, 1 de cada resina, totalizando 86 restaurações. Fez-se a avaliação inicial das restaurações, o “baseline", 7 dias após a sua confecção, por 2 examinadores. Cada item recebia um escore em 3 níveis: bom (0), aceitável (1) e inaceitável (2). Somente para a cárie considerava-se 2 níveis: ausente (0) e presente (1). Fotografou-se as restaurações em todos os períodos de observação. Obteve-se moldagens das restaurações de 10 pacientes, para análise e fotografias em Microscópio Eletrônico de Varredura, com aumento de 40 X. Dos 43 pacientes, 8 não retornaram, assim, analisou-se estatisticamente pelo teste exato de Fisher, 70 restaurações. No baseline, 34 restaurações com a resina composta Z-100 e 35 com a Fill Magic receberam escores zero em todas as categorias, com exceção de 1 caso com a resina Z-100 que recebeu escore 1 para o critério cor. Para esse mesmo critério, aos 6 meses, 35 restaurações com a Fill Magic e com a Z-100, 31 restaurações receberam escores zero e 4 mereceram escores 1. Em 1 ano, 31 restaurações com a Z-100 ficaram com escores zero e 4 com escores 1; 34 restaurações com Fill Magic obtiveram escores zero e 1 obteve escore 1, com relação à cor. Aos 2 anos, também com relação à cor, para 3 restaurações com Z-100 e para 1 com Fill Magic atribuíram-se escores 1; escores 0 foram aplicados a 32 das restaurações de Z-100 e a 34 das de Fill Magic. Exceto para a categoria cor, que sofreu mudanças com o passar do tempo, todas as restaurações receberam escores 0 na avaliação “baseline", 6 meses, 1 ano e 2 anos. Nenhum escore 2 foi anotado. Não observou-se diferença estatisticamente significante entre as 2 resinas compostas, aceitando-se a hipótese de igualdade entre as mesmas. / The purpose of this study was to clinically evaluate two composite resins at 2-year period. Seventy Class III restorations were made by only one operator, 35 with Z-100 composite resin and 35 with Fill Magic. The teeth were selected based on clinical exams. Restorations included only anterior superior teeth. Following cavity preparations, under rubber dam, they were protected with calcium hydroxide and/or a glass ionomer base. Magic Adhesiv/Fill Magic (Vigodent) and Scotchbond Multipurpose Plus/Z-100 (3M) were used for adhesion to exposed dentin and enamel and restoration of the cavities. The cavities were restored in increments. Restorations were finished using multi-laminated burs, Sof-Lex discs and Enhance System. Evaluation was assessed after finishing and polishing approximately one week after placement (baseline), 6 months, 1 year and 2 years using the modified Ryge criteria for color, marginal discoloration, anatomic form, marginal integrity, secondary caries and post-operative sensitivity. There were three levels of scores for each category: good (0), acceptable (1) and unacceptable (2). Only for secondary caries there were 2 levels: absent (0) and present (1). Besides, it was investigated the occurrence of postoperative sensitivity, which was classified as the other scores were for another characteristics observed. At every evaluation, impressions from the restorations were made and they were examined by scanning electron microscopy. At baseline, there was one score “one" for category color for Z-100 composite resin; the other restorations and the other composite resin were graded to be “zero". At 6 months recall, the restorations were assessed and there were four scores “one" for Z-100 composite resin. The restorations were evaluated at 1 year and the results were as follow: there were four scores “one" for Z-100 composite resin and one score “one" for Fill Magic composite resin with regard to color. At 2-year evaluation were observed three scores “one" for Z-100 composite resin and one score “one" for Fill Magic. Except for color category, all the restorations received score “zero" either for 6 months, 1-year and 2- year recalls. No scores “two" were noted. The results were analyzed by Fisher Exact Statistical Test. No significant differences were noted between both composite resins. In conclusion, these two composite resins demonstrated excellent clinical acceptability in all categories assessed, making them suitable for anterior restorations.

Neste trabalho foi desenvolvida uma nova metodologia para a síntese de calcogenoacetilenos. Para isto, foram utilizados haletos de índio III como catalisadores, uma base para ativar o alcino terminal e um dicalcogeneto de diorganoila. Foram avaliados diferentes haletos de índio; a saber, InCl3, InBr3 e InI3. Diferentes bases também foram testadas, sendo que a mais efetiva na promoção da reação foi o Cs2CO3. A quantidade de catalisador também foi avaliada, sendo que a que o melhor resultado foi observado quando 10 mol % de InCl3 foi empregada. Alem de testes com catalisadores e bases, foram realizados testes com diferentes solventes, e o solvente que se mostrou mais efetivo foi DMSO. A reação está mostrada abaixo, o mecanismo da mesma será elucidado no decorrer desta dissertação. Depois de otimizadas as condições reacionais, a metodologia foi estendida a diferentes disselenetos, um dissulfeto e um ditelureto, onde a reação apresentou bons rendimentos em geral. Os rendimentos obtidos com diferentes calcogênios foi na ordem S<Se<Te, o que pode ser explicado pela força de ligação S-S ser maior que Se-Se que é maior que Te-Te. A reação também foi extendida a grupos alquílicos, que reagiram bem tanto no lado do disseleneto quanto no lado do alcino. Por fim foi proposto um mecanismo evidenciado pelos resultados obtidos nos testes realizados. Onde pode ser explicado o efeito eletrônico da reação e o efeito do solvente, onde o DMSO foi escolhido como o melhor solvente para a reação. / A new approach for the one-pot synthesis of alkynyl chalcogenides, exemplified mainly by selenides, was developed in which dual activation of diorgano dichalcogenides and terminal acetylenes is achieved by using an indium(III) catalyst. The method has advantages of broad substrate scope, simple operation, mild reaction conditions, and good yields. A plausible reaction mechanism is proposed.