Orientador: Fernando Aparecido Sigoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T22:25:31Z (GMT). No. of bitstreams: 1 Petiote_Lanousse_M.pdf: 4326996 bytes, checksum: a438622b7ca8e3a70bbbec5abf7dc735 (MD5) Previous issue date: 2015 / Resumo: Esse trabalho reporta o estudo das propriedades fotoluminescentes de uma série de complexos dinucleares de lantanídeos trivalentes contendo os ligantes 2 tenoiltrifluoro-acetilacetonato (tta), óxido de [2 (difenilfosforil)etil]difenilfosfina (dppeo), e óxido de trifenilfosfina (tppo). Os complexos de formula geral [{Ln(tta)3(tppo)}2(µ-dppeo)] foram obtidos a partir do controle da estequiometria e da ordem de adição dos reagentes em reações envolvendo os ligantes fosfinóxidos e os complexos precursores [Ln(tta)3(H2O)2]. A caracterização foi realizada por análise elementar, espectroscopia vibracional na região do infravermelho, espectroscopia eletrônica na região do visível, ressonância magnética nuclear de 1H e de 31P e análise termogravimétrica. Para os complexos de európio(III), são apresentados cálculos semi-empíricos realizados baseando-se nas geometrias de coordenação do estado fundamental desses complexos usando o modelo SPARKLE/AM1. Os espectros de fotoluminescência exibem as bandas de emissão características dos íons lantanídeos utilizados confirmando a atuação do efeito antena nos mesmos. Os espectros de emissão dos complexos do íon Eu(III) apresentam elevados valores da razão assimétrica I(5D0?7F2)/ I(5D0?7F1) e de ?2 evidenciando a presença dos íons Eu(III) em ambientes químicos de baixa simetria e a atuação do acoplamento dinâmico. Os complexos de európio(III) mostram um aumento do tempo de vida de emissão e do rendimento quântico com a substituição das moléculas de água devido a diminuição das taxas de decaimentos não radiativos do nível emissor 5D0. A energia do nível tripleto do complexo [{Eu(tta)3(tppo)}2(?-dppeo)] determinada experimentalmente e calculada apresentam boa concordância. Os cálculos das taxas de transferência e retro-transferência de energia mostram que, no caso da transferência de energia dos ligantes para o íon Eu(III), as rotas mais eficientes são T?5D1 e T?5D0. As coordenadas de cromaticidade da Commission Internacionale d¿Éclairage (CIE) indicam que a luz vermelha emitida pelos complexos contendo íons Eu(III) apresenta alta pureza. Os complexos com emissões na região do infravermelho próximo apresentam tempos de vida de emissão 10 vezes menor do que os complexos de európio devido baixa eficiência do efeito antena e a desativação não radiativa dos níveis emissores dos íons Er(III) e Yb(III). Palavras-chave: Lantanídeos. Complexos dinucleares. Luminescência. Efeito Antena / Abstract: This work reports on photoluminescent properties of a series of lanthanide dinuclear complexes containing 2- thenoyltrifluoroacetylacetonate, [2 (diphenylphosphoryl)ethyl](diphenyl)phosphine oxide and triphenyl oxide as ligands. The complexes have the general formula [{Ln(tta)3(tppo)}2(µ-dppeo)] and were obtained by controlling the stereochemistry and reagents addition in reactions involving the phosphine oxide ligands and precursor complexes [Ln(tta)3(H2O)2] The characterization was carried out using elemental analysis, IR vibrational spectroscopy, UV-Vis electronic spectroscopy, 1H and 31P NMR and thermogravimetric analysis techniques. Semi-empirical calculations have been carried out using the fundamental geometries of europium(III) complexes optimized by the SPARKLE/AM1 model. The photoluminescence spectra under excitation in the ligand show the narrow bands characteristics of lanthanide ions used, confirming that the antenna effect is operating in all complexes. The emission spectra of Eu(III) complexes show high values of either asymmetric ratio I(5D0?7F2)/ I(5D0?7F1) and the intensity parameter ?2 indicating low-symmetry chemical environments occupied by Eu(III) ions and contribution of the dynamic coupling mechanism. The Eu(III) complexes show an increasing of the luminescence lifetime and the quantum yield as the water molecules have been substituted. This was attributed to a reduction of the non-radiative decay of the 5D0 level in complexes without water molecules in the coordination sphere of lanthanide trivalent ion. The experimental value of the triplet energy level for the complex [{Eu(tta)3(tppo)}2(?-dppeo)] is consistent with the calculated one. Calculations of the energy transfer rates in the europium complexes show that the most efficient routes are T?5D1 e T?5D0. The chromaticity coordinates indicate high purity for the red light emitted by the europium complexes. The complexes with emission in the near infrared region show emission life 10 times lower than the europium complex. This was attributed to different factors such as low relative efficiency of the antenna effect and the efficient non-radiative deactivation of emitting levels in Er (III) and Yb (III) mainly by C-H oscillators in the ligands. Keywords: Lanthanides, Dinuclear complexes, Luminescence, Antenna effect / Mestrado / Quimica Inorganica / Mestre em Química

Orientadores: Vera Lúcia da Silveira Nantes Button, Marcelo Baptista de Freitas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-28T09:42:26Z (GMT). No. of bitstreams: 1 Malthez_AnnaLuizaMetidieriCruz_D.pdf: 4070699 bytes, checksum: 5b502eb8b2975aac6052df7ad659d32a (MD5) Previous issue date: 2015 / Resumo: Neste estudo foi desenvolvido um dosímetro (monitor individual) para monitoração externa de indivíduos ocupacionalmente expostos à radiação (raios X e gama) que faz o uso simultâneo das técnicas de termoluminescência (TL) e luminescência opticamente estimulada (OSL - Optically Stimulated Luminescence), combinado às diferentes características dosimétricas de detectores já utilizados com a técnica TL na rotina dos Serviços de Monitoração Individual Externa (SMIEs) no Brasil (LiF:Mg,Ti ¿ TLD100, CaF2:natural, CaSO4:Dy - IPEN) e detectores utilizados com a técnica OSL, ainda pouco explorados na monitoração individual (BeO ¿ Thermalox 995) e recentemente autorizados a serem utilizados com a técnica OSL no país (Al2O3:C - Luxel). Para o desenvolvimento do monitor, diversas características intrínsecas e dosimétricas dos detectores empregando as técnicas TL e OSL em três diferentes equipamentos leitores foram avaliadas. Testes de desempenho foram aplicados ao monitor desenvolvido, conforme critérios estabelecidos no país e no exterior (CASEC e IEC, respectivamente). Os resultados obtidos demonstram que as respostas TL e OSL dos detectores dependem fortemente da configuração do leitor utilizado, da técnica empregada (TL ou OSL) e do tipo de sinal avaliado, no caso da técnica OSL (OSL total ou inicial). Assim é fundamental uma análise prévia de características intrínsecas do material, como comprimento de onda principal da emissão luminescente, tipo (inicial ou total) e magnitude (doses baixa, moderada ou alta) do sinal que será avaliado para a escolha adequada dos parâmetros do leitor (filtros, máscaras, potência, entre outros) empregando as duas técnicas. Os resultados obtidos com a técnica OSL reforçam seu uso na monitoração individual no Brasil, uma vez que estavam em acordo com a técnica TL, amplamente empregada pelos SMIEs nacionais. Além da determinação de dose individual, normalmente empregada na monitoração de trabalhadores, o dosímetro desenvolvido permite também estimar doses acumuladas ao longo do tempo, empregando a técnica OSL nos detectores de Al2O3:C ou BeO, sendo que no caso deste último, a dose única (ou individual) também pode ser determinada com a técnica TL aplicada simultaneamente no mesmo detector. Após a avaliação das respostas em energia dos detectores, um algoritmo foi desenvolvido, testado e validado para avaliar fatores de correção com respeito à energia, baseado na razão entre as respostas de um par de detectores TL e OSL. Os resultados demonstraram que as diferentes razões entre os sinais provenientes do par, permitem avaliar de forma precisa a qualidade da radiação à qual o par de detectores foi exposto. O monitor desenvolvido possui três configurações diferentes de pares de detectores, Al2O3:C/LiF:Mg,Ti, Al2O3:C/BeO e CaSO4:Dy/BeO. Ele apresenta como principais vantagens, em relação aos dosímetros já existentes em uso comercialmente, a possibilidade de poder inferir informações sobre a dose e qualidade da radiação (energia efetiva) sem a utilização de filtros e com diminuição das incertezas associadas, avaliar doses acumuladas ao longo do tempo com o mesmo dosímetro e combinar todas as características dos detectores associadas às técnicas TL e OSL, simultaneamente em um mesmo dosímetro. Os resultados dos testes de desempenho do monitor apresentaram conformidade com os critérios nacionais e internacionais estabelecidos, e contribuíram para que os critérios nacionais utilizados para a técnica TL possam ser estendidos para a técnica OSL / Abstract: In this study a dosimeter (personal monitor) for external monitoring of individuals occupationally exposed to radiation (X and gamma rays) was developed using simultaneously thermoluminescent (TL) and optically stimulated luminescence (OSL) techniques. Intrinsic characteristics of detectors already used with TL technique in External Individual Monitoring Services routine in Brazil (LiF:Mg,Ti ¿ TLD 100, CaF2:natural and CaSO4:Dy ¿ IPEN) were combined to detectors used with OSL technique, one less explored (BeO ¿ Thermalox 995), and other recently approved (Al2O3:C - Luxel) to be used in individual monitoring in the country (Al2O3:C - Luxel). During the monitor development, several intrinsic and dosimetric characteristics of detectors were evaluated employing TL and OSL techniques in three different reader equipments. Performance tests were applied to the developed monitor according to national and international established criteria (CASEC and IEC, respectively). The obtained results showed that the responses of TL and OSL detectors are strongly dependent on reader configuration, employed technique (TL and OSL) and, in the particular case of OSL technique, also the signal (total or initial OSL). Therefore, a previous analysis of the intrinsic characteristics of the material, as the main wavelength of the luminescent emission, the signal type (initial or total) and dose magnitude (low, moderate or high) must to be made in order to select the reader configuration (filters, power, and others) used with each technique. The results obtained with OSL technique reinforce its use in Brazil, as they were in agreement with TL technique, which is already largely used by national EIMS. In addition to the assess of individual dose, usually employed in workers monitoring, the developed dosimeter allows evaluating accumulated dose over time using OSL technique with Al2O3:C or BeO detectors, and single or individual doses can be evaluated applying TL technique simultaneously applied in the same detector. After the evaluation of the energy response of detectors, an algorithm was developed, tested and validated to assess correction factors with respect to energy, based on the ratio of the responses of a pair of TL and OSL detectors. The results confirm that the different ratios between signals from a detector pair allow to evaluate more accurately the radiation quality to that the pair of detectors were exposed. The monitor was developed with three different arrangements of pairs of detectors, Al2O3:C/LiF:Mg,Ti, Al2O3:C/BeO and CaSO4:Dy/BeO. It presents as main advantages, compared to existing commercial dosimeters in use, the possibility to infer information on the dosage and quality of radiation (effective energy) without the use of filters and reducing associated uncertainties, to assess cumulative doses over time with the same dosimeter, and to combine all features of the detectors associated with TL and OSL techniques, simultaneously, in the same dosimeter. The results of the performance tests of the developed monitor were in accordance to national and international criteria, and contributed to that the national criteria, used for TL technique, can also be extended to the OSL technique / Doutorado / Engenharia Biomedica / Doutora em Engenharia Elétrica

Orientador: Sérgio Tosi Rodrigues / Resumo: O envelhecimento populacional está associado a profundas mudanças sociais, econômicas e culturais. O comprometimento perceptual e cognitivo resultante do envelhecimento pode provocar falhas durante o desempenho da condução de automóvel. Os fatores humanos desempenham um papel fundamental nos riscos de acidentes de trânsito. O objetivo do presente estudo foi determinar os efeitos do envelhecimento do motorista e da luminosidade do ambiente sobre o tempo de reação da frenagem, durante a condução simulada de automóveis. Quinze motoristas adultos jovens e quinze motoristas idosos realizaram uma tarefa de condução na qual foram mensurados os tempos de reação envolvidos na frenagem (retirada do pé do pedal do acelerador e acionamento do pedal de freio) em um simulador de direção de um automóvel. A tarefa dos participantes foi seguir por um percurso de 5 km um carro à frente, que freava bruscamente acendendo a luz vermelha traseiro do carro, em duas condições: uma com luminosidade diurna e outra com luminosidade noturna. Um pré-teste de tempo de reação simples utilizando os pedais de acelerador e freio, fora do cenário simulado da condução, foi realizado como situação controle. Os dados da condução simulada foram submetidos à análise de variância do grupo (adultos, idosos) por luminosidade (diurna, noturna), com medidas repetidas no segundo fator. Nas condições de condução do veículo, os idosos mostraram tempo de reação maior tanto para retirar o pé do acelerador quando para acionar... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Population aging is associated with profound social, economic and cultural changes. The perceptual and cognitive impairment resulting from aging can cause failures during car driving performance. Human factors play a key role in the risks of traffic accidents. The aim of this study was to determine the effects of driver’s aging and ambient luminosity on the braking reaction time during simulated car driving. Fifteen young adult drivers and fifteen elderly drivers performed a driving task in which the reaction times involved in braking (removing the foot from gas pedal and pressing brake pedal) were measured in a car driving simulator. Participants’ task was to follow a car in front of them during a 5 km path, which braked abruptly with the rear red light turning on, in two conditions: day and night light conditions. A simple reaction time pre-test utilizing gas and brake pedals, out of the simulated driving scenario, was conducted as a control situation. Data from driving conditions were submitted to a group (adults, elderly) by luminosity (day, night) analysis of variance, with repeated measures in the second factor. During driving conditions, the elderly group showed greater reaction time to release the gas pedal and to press the brake pedal; the same occurred to the total reaction time in the total reaction time. Interestingly, reaction times during day light luminosity were greater than those during night luminosity for gas pedal and total reaction times. Results are disc... (Complete abstract click electronic access below) / Mestre

<div>The family Flaviviridae includes important genera such as flavivirus and hepacivirus which comprise significant human pathogens that affect hundreds of millions annually. The understanding of these viruses, the viral life cycle, and pathogenicity is vital when it comes to developing therapeutics. Flavivirus virions undergo major conformational rearrangements during the life cycle, including the assembly and maturation steps. In order to create a reagent to investigate these processes, luminescent reporter viruses have been constructed. Luminescent reporter tags have yet to be incorporated into the structural proteins of dengue virus (DENV) without significantly affecting replication or infectivity and successful tagging would allow for targeted studies examining access to specific structural epitopes. Engineering tags in DENV structural proteins is particularly difficult because most reporter tags involve large insertions which may create steric hindrance and inhibit proper protein folding. However, the reporter system described here, developed by Promega, is much smaller than a full-size luciferase protein. It involves an eleven amino acid subunit (HiBiT) tagged to a viral protein that creates measurable luminescence when incubated with the larger subunit (LgBiT). Using the structure of the virion as a guide, the HiBiT reporter tag was incorporated into the structural region of the DENV genome including sites in capsid (C) as well as the glycoproteins membrane (M) and envelope (E). Resulting recombinant viruses were characterized and tag sites within the C protein membrane anchor as well as the transmembrane domain of M protein were found to tolerate HiBiT insertion and produce infectious particles. The recombinant virus possessing HiBiT in C protein was found to be stable over three rounds of serial passaging while virus containing the M protein tag site was found to be unstable. HiBiT activity of the capsid tagged virus was also found to directly correlate with purified infectious particles, suggesting the capsid membrane anchor may remain associated with the virus even after polyprotein processing. Additionally, insert composition was found to be a key determinant for the production of infectious virus. The lessons learned from engineering HiBiT in the DENV system were then applied to hepatitis C virus (HCV). </div><div>The highly lipophilic and pleiomorphic nature of HCV has made structural studies particularly difficult. However, by constructing multi-tagged reporter viruses containing both HiBiT and various purification tags, researchers will save time and resources in preparation for structural studies which are vital for vaccine development. In this study, HiBiT was incorporated into sites within HCV previously shown to tolerate tags of various sizes. Different insert compositions were engineered within the genome and the construct containing both FLAG and HiBiT tags within the N-terminus of E2 yielded highly infectious and quantifiable, luminescent virus. The recombinant HCV containing FLAG and HiBiT displayed similar peak titer as compared to WT while also demonstrating HiBiT activity. Furthermore, the FLAG peptide was found to be partially surface exposed and capable of being used for virus purification purposes. The multi-tagged reporter virus characterized in this study provides a robust platform for quantification and purification of HCV, two facets of research that are critical for the determination of viral structure via cryo-EM and other imaging techniques. The findings from both the DENV and HCV studies provide a robust foundation for future tagging of viruses within the family Flaviviridae and offer insight on the structural proteins that compose the virion.</div>

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22452号 / 工博第4713号 / 新制||工||1736(附属図書館) / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 田中 勝久, 教授 三浦 清貴, 教授 藤田 晃司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23229号 / 工博第4873号 / 新制||工||1760(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 松田 建児, 教授 杉野目 道紀, 教授 生越 友樹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Thesis advisor: Baldassare Di Bartolo / Thesis advisor: Pradip Bakshi / The search for multicolored light produced by some IR laser-excited luminescent nano-powders has revealed, for laser power exceeding a threshold value, the emission of white light (WL) with black-body characteristics. I am directing my research to the study of the physical parameters that may influence the threshold power of the laser and the efficiency of the WL emission. A typical compound that I will investigate will consist of nano-powders of SrZrO3 doped with Yb. The parameters of relevance may include Yb concentration, pressure, temperature, size of nano-crystals, exciting power and wavelength of the laser, dynamical parameters such as decay and build-up patterns. The aim of my research will be both theoretical and experimental: theoretical for I will try to uncover the mechanism of the WL production and experimental for the possible application as efficient light sources of systems similar to the ones that I will investigate (oxide nano-powders doped with lanthanide or transition metal ions). The “new” light sources in the market (fluorescence lights sources, and LED lamps) beat the Edison bulbs in efficiency, but they do not produce the black-body emission of the Edison bulbs that is most pleasing to the eye. The search for efficient black-body type of sources is still on and we want to be a part of it. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Current methods for preparing graphene quantum dots (GQDs) rely on oxidation and reducing agents or require energy-intensive and technologically demanding preconditions. Applying microwave expansion and liquid phase exfoliation (LPE) in a sample of graphite powder enabled us to prepare GQDs that exhibit strong luminescence in the blue region of the visible spectrum. The proposed technique for synthesizing GQDs is energetically undemanding and does not necessitate additional chemical components.

Diagnostic of photovoltaic cells defects is one of the key step in production. This dissertation thesis deals about diagnosis of photovoltaic cells by radiative recombination of electron - hole pairs. This radiative recombination is known as luminescence. Diagnostic methods using this local light emission in infrared region have innovative potential. The method of electroluminescence is one of the most widely used luminescence methods whose modifications are applied across the industry, especially in semiconductors. The main area of this thesis research is focused on non-destructive analysis of radiated infrared radiation of monocrystalline and polycrystalline solar cells in various modifications of standard electroluminescence method. In this research there are used two types of CCD cameras are used as luminescent radiation detectors. Method of photon emission microscopy is used for magnification element. Local light emission inspection by microscopy should have benefit to qualitative evaluation of solar cells defects. Radiation emitted by the solar cell has a wave character. This fact brings the potential of using some of the characteristics of the waves. We are talking about the intensity and mainly about new characterization by polarization during the detection of defects in the solar cell surface. Innovation of the measuring workplace of the standard electroluminescence method to use polarization analysis is one of the goals of this dissertation thesis.

Ma thèse a été centrée sur l’étude par luminescence à deux photons (TPL) de nanostructures d’or uniques, éventuellement couplées, dans le but d’en déterminer les propriétés de nano-antennes optiques. Les différentes expériences réalisées ont permis de mettre en évidence les paramètres clés à l’origine de la luminescence à deux photons (TPL) permettant de mettre en évidence le rôle du plasmon transverse. Ce résultat a été confirmé par l’étude de nanobipyramides présentant des caractéristiques plasmoniques légèrement différentes. Ce modèle a été approfondi via l’étude des propriétés TPL de nanobâtonnets présentant des volumes différents mais des résonances plasmoniques identiques. Enfin, en confrontant les résultats expérimentaux à des simulations obtenues par BEM (Boundary Element Method), nous avons montré que le signal provenait a priori des atomes du volume de la NP. Des problèmes de photo-dégradations ont par ailleurs été constatés et analysés. Au-delà des nano-bâtonnets, nous avons quantifié les effets dits de pointes de nanobipyramides présentant des caractéristiques plasmoniques proches de celles des bâtonnets. Nous avons également pu mettre en évidence de très fortes intensités TPL sur les points chauds issus d’échantillons d’or semi-continu. Un second volet de mes travaux a concerné la mise en œuvre et la caractérisation des propriétés optiques linéaires et non-linéaires de nano-émetteurs hybrides individuels couplant une nano-antenne à des fluorophores. Différentes techniques ont été testées : la mise en œuvre de dépôts multicouches (méthode dite « layer-by-layer »), ou la nanophotopolymérisation localisée. Dans les deux cas, outre la complexité de mise en œuvre de ces techniques, nous avons été confrontés à la difficulté d’extraire le signal des molécules du très fort signal de luminescence à deux photons des nanostructures d’or. / My PhD work has been dealing with the two-photon luminescence (TPL) study of single gold nanostructures, possibly coupled in order to determine their nano-antenna optical properties. Key parameters to explain the origin of the TPL were provided from the two-photon luminescence study of single small 10 nm x 40 nm colloidal gold nanorods (GNR) which highlight the transverse plasmon influence. This origin was confirmed by the results obtained after the characterization of nanobipyramid exhibiting plasmonic properties closed to nanorods. A deeper insight in this model was further developed after investigating the properties of gold nanorods having closed aspect ratio and plasmonic resonances but increasing volume. Experimental data were correlated with BEM (Boundary Elements Method) simulations. It was shown that the TPL signal was coming from the bulk atoms. Photodegradations problems have moreover been observed and analyzed. Above the analysis of gold nanorods, the lightning rod effect of nanobipyramid was also investigated. Finally very high TPL intensity spots were recorded in semi-continuous gold films close to percolation. A second part of my study was related to the fabrication and the characterization of the optical properties of hybrid nano-emitters. They were fabricated by coupling a nano-antenna with fluorophores. Two different techniques were tested: the so-called layer-by-layer method and localized nanophotopolymerization. In both cases, together with the difficulty to accurately control both methods, retrieving the molecules signal from the huge TPL signal of the gold nanostructures was shown to be rather difficult.