Thesis (M.S.)--Rochester Institute of Technology, 1996. / Typescript. Bibliography: leaves 23-24.

Made available in DSpace on 2018-08-01T21:58:48Z (GMT). No. of bitstreams: 1 tese_10763_Mayra Nicoli Moura - Dissertação corrigida.pdf: 3004599 bytes, checksum: 5d4e91152db73883ca3959418fd139f2 (MD5) Previous issue date: 2017-03-22 / Cobalto do cátodo das baterias de íon lítio (LIBs) exauridas de telefones celulares Samsumg® foi reciclado como ferrita dopada com cobalto. O zinco do ânodo das pilhas alcalinas (Zn-MnO2) Duracell® AA foi reciclado para a formação da ferrita dopada com zinco. As ferritas foram aplicadas como catalisadores em reações foto Fenton heterogêneo para a descoloração do corante azul de metileno. Pela análise de difração de Raios-X (DRX) identificou-se formação de ferritas não dopadas, dopada com cobalto e dopada com zinco do tipo espinélio. Com auxilio das técnicas: microscopia eletrônica de varredura (MEV) e microscopia eletrônica de transmissão (MET) verificou-se que as ferritas não dopadas, dopada com cobalto e dopada com zinco formam aglomerados de partículas nanométricas. Pelas análises de espectroscopia de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectro de absorção atômica com chama (F AAS) foi possível determinar as concentrações dos metais presentes nas ferritas. As concentrações de cobalto foram 70,0 ± 4,0 mg.g-1 e 65,0 ± 2,0 mg.g-1 nas ferritas dopadas com cobalto a partir de reagente analítico e da bateria de íon lítio, respectivamente. As concentrações de zinco nas ferritas dopadas com zinco a partir de reagente analítico e da pilha alcalina, respectivamente foram iguais 26,0 ± 1,0 mg.g-1 e 89,0 ± 4,0 mg.g-1. A condição otimizada para a descoloração do corante foi avaliada por um planejamento fatorial. A melhor condição para reação catalítica usando como catalisador CoFe2O4 foi pH 3,0, 30 mg de catalisador e 8 mL de H2O2, obtendo a porcentagem de eficiência de degradação igual a 61,5%, 87,3% e 87,7% para ferrita não dopada, dopada com cobalto a partir de reagentes analíticos e dopada com cobalto a partir da solução lixiviada da bateria de íon-Li e CoFe2O4-LIBs, respectivamente, após 420 minutos. A dopagem melhorou a eficiência da descoloração da solução de azul de metileno. A melhor condição experimental otimizada para ZnFe2O4 foi 30 mg de catalisador, 8 mL de H2O2 em pH 6,0. A eficiência de descoloração obtida foi igual a 45,9%, 92,2% e 37,0% para ferrita não dopada, dopada com zinco a partir de reagente analítico e dopada com zinco a partir da lixiviação da pilha alcalina, após 240 minutos de reação.

<p> The photo-addition of 2-cyclohexenone to norbornadiene has been investigated. A substantial proportion of the products formed were α, β unsaturated ketones. The structure of these has been assigned and a rationale is presented to explain the formation of these products. </p> / Thesis / Master of Science (MSc)

No description available.

The effect of light on a model colloidal beverage system under two different test conditions, refrigerated storage (14 d, 4°C) and accelerated storage at room temperature (12 hr, 25°C), was investigated. The addition of lutein to provide protection against photo-oxidation of susceptible compounds also was investigated. Fluorescent light-exposure (14 d, 4°C) of the control beverage system led to a decline in sensory quality based on triangle test results. Sensory quality also declined in the lutein-fortified beverage due to light-exposure. Sensory quality of light-exposed, lutein-fortified beverage compared to the light-protected control did not yield significant sensory differences for two out of three replications giving positive implications towards the use of lutein for photo-protection. Overall, panelists preferred beverages that were protected from light exposure with no specific preference towards control or lutein-fortified beverage, indicating lutein did not inhibit photo-chemical reactions leading to a decline in sensory quality. Chemical analysis showed limonene concentration was significantly higher in the lutein-fortified beverage compared to the control beverage after light exposure (14 d, 4°C). Hexanal concentration, however, was not closely correlated with sensory differences. Results of the accelerated storage (12 hr, 25°C) study showed that the most damaging wavelengths to lutein stability were UV (200-400 nm) and 463 nm wavelengths. Degradation of lutein at 463 nm was expected and can be attributed to lutein''s absorption of blue light at 450 nm. Hexanal formation was highest in the control beverage when exposed to full spectrum light and specifically UV (200-400 nm) wavelengths. Hexanal was also formed in the lutein-fortified beverage under full spectrum light and UV (200-400 nm) wavelength but to a significantly lesser degree. Limonene degraded significantly under all treatment conditions, with the most occurring during full spectrum light exposure. Lutein-fortification did not effectively protect limonene from degradation under these conditions. / Master of Science in Life Sciences

A study of the mercury-sensitized photo-reactions of isobutane.

Le processus de sélection de photos dans des albums peut être considérablement amélioré à l’aide d’un critère d’évaluation automatique des qualités d’une photo. Cependant, les méthodes existantes abordent ce problème de manière indépendante, c’est à dire en évaluant chaque image séparément des autres images d'un album. Dans cette thèse, nous explorons la modélisation du contexte d’une photo via une approche de clustering de collections de photos et la possibilité d'appliquer l’information de contexte à l'évaluation d’une photo. Nous avons effectué des études subjectives permettant d’étudier la manière dont les utilisateurs regroupent et sélectionnent des photos dans un album. Ces études ont permis une estimation du niveau de l’accord entre les différents utilisateurs. Nous avons aussi étudié la manière dont le contexte influence leurs décisions. Après avoir étudié la nature des décisions des utilisateurs, nous proposons une approche informatique pour modéliser leur comportement. Tout d'abord, nous introduisons une méthode de clustering hiérarchique, qui permet de regrouper des photos similaires selon une structure de similarité à plusieurs niveaux, basée sur des descripteurs visuels. Ensuite, les informations de contexte de la photo sont utilisées pour adapter le score de la photo pré-calculé indépendamment, en utilisant les données basées sur des statistiques et une approche d'apprentissage automatique. De plus, comme la majorité des méthodes récentes d'évaluation de la photo sont basées sur des réseaux de neurones convolutionnels, nous avons exploré et visualisé les caractéristiques esthétiques apprises par ces méthodes. / An automatic photo assessment can significantly aid the process of photo selection within photo collections. However, existing computational methods approach this problem in an independent manner, by evaluating each image apart from other images in a photo album. In this thesis, we explore the modeling of photo context via a clustering approach for photo collections and the possibility of applying such context information in photo assessment. To better understand user actions within photo albums, we conduct experimental user studies, where we study how users cluster and select photos in photo collections. We estimate the level of agreement between users and investigate how the context, defined by similar photos in corresponding clusters, influences their decisions. After studying the nature of user decisions, we propose a computational approach to model user behavior. First, we introduce a hierarchical clustering method, which allows to group similar photos according to a multi-level similarity structure, based on visual descriptors. Then, the photo context information is extracted from the obtained cluster data and used to adapt a pre-computed independent photo score, using the statistics-based data and a machine learning approach. In addition, as the majority of recent methods for photo assessment are based on convolutional neural networks, we explore and visualize the aesthetic characteristics learned by such methods.

В работе исследуется новый вид изоизданий: фотопроект. Рассматривается общая характеристика изоизданий, структурно-содержательные и визуально-полиграфические особенности. Также раскрывается понятие фотокниги как вида издания.Проводится анализ фотокниг. Практическая часть подразумевает этапы создания фотопроекта «Женщина», где также даются практические рекомендации по разработке изоизданий. / In this paper, we investigate a new kind ofart book: a photo project. The general characteristics of theart book, structural-content and visual-printing features are considered. The concept of a photobook as a type of publication is also revealed. The analysis of photobooks is carried out. The practical part includes the stages of creating a photo project «Woman», which also provides practical recommendations for the development of photo publications.

L’objectif principal de ce travail de thèse était de mettre en évidence et de mesurer l’effet co-catalytique de complexes moléculaires organo-métalliques à base de métaux de transition adsorbés sur des semi-conducteurs dopés photo-actifs vis-à-vis des réactions de photo-dissociation de l’eau et de photo-réduction du dioxyde de carbone, en en vue d’applications dans des cellules photochimiques et photo-électrochimiques. Nous avons tout d’abord identifié et sélectionné les matériaux (deux semi-conducteurs photo-actifs et deux co-catalyseurs moléculaires électroactifs) les plus adaptés (les résultats sont présentés dans le chapitre I). Nous avons ensuite conçu, développé et mis au point un bâti expérimental permettant la détection et le dosage en continu des produits de réaction lors des réactions d’intérêt (les résultats sont présentés dans le chapitre II). La détection des produits de réaction se fait à l’aide d’un chromatographe en phase gazeuse couplé au réacteur. Nous avons ensuite élaboré/synthétisé et mesuré les propriétés intrinsèques des matériaux sélectionnés (les résultats sont présentés dans le chapitre III). Finalement, nous avons mis en évidence l’activité co-catalytique des complexes utilisés et mesuré un ensemble d’indicateurs de performance tels que les cinétiques de réaction et les fréquences de « turn-over » (les résultats sont présentés dans le chapitre IV). / The main objective of this research work was to put into evidence the co-catalytic effect of organo-metallic molecular complexes containing transition metals as reactive centers, adsorbed at the surface of doped semiconductors with photo-activity with regard to water photo-dissociation and carbon dioxide photo-reduction, in view of practical applications in photochemistry and photo-electrochemistry. First, appropriate materials (two photoactive semiconductors and two molecular co-catalysts) have been identified and selected (results are presented in chapter I). Then, we have designed, constructed and optimized a specific test bench that can be used for the continuous detection and titration of reaction products (results are presented in chapter II). Product analysis was achieved by coupling a gas-phase chromatograph to the photo-electrochemical reactor. Then, photoactive semiconductors and molecular co-catalysts have been elaborated/synthesized and their intrinsic properties have been measured (results are presented in chapter III). Finally, the co-catalytic activity of molecular complexes has been put into evidence and several performance indicators such as reaction kinetics and turn-over frequency have been measured (results are presented in chapter IV).

Halorhodospira halophila photoactive yellow protein (PYP) is a promising candidate to act as a photoswitching domain in engineered proteins due to the structural changes that occur during its photocycle. Absorption of a photon of wavelength 446 nm triggers trans to cis isomerization of its 4-hydroxycinnamic acid chromophore leading to large structural perturbations in the protein, particularly in the N-terminus. In the dark, a slower cis to trans reisomerization of the chromophore restores the protein’s native fold. The fusion of proteins to PYP’s N-terminus may therefore enable photomodulation of the activity of the attached protein. To test this hypothesis, this thesis descibes genetically encoded photoswitchable DNA-binding proteins that were developed by fusing the prototypical leucine-zipper type DNA-binding protein GCN4 bZIP to the N-terminus of PYP. Five different fusion constructs of full length or truncated GCN4 bZIP and full length PYP as well as fusion constructs of full length GCN4 bZIP and N-terminally truncated PYP mutants were designed in a structure-based approach to determine if the dimerization and DNA binding activities could be controlled by the PYP photocycle. Extensive biophysical characterization of the fusion constructs in the dark and under blue light irradiation using electronic absorption, circular dichroism and fluorescence spectroscopic techniques were performed. As all the fusion proteins could complete photocycles, the DNA binding abilities of the dark and light-adapted states of the proteins were characterized using spectroscopic techniques as well as by the electrophoretic mobility shift assay. All the fusion constructs maintained DNA-binding abilities, however they each differed in their affinities and the extent to which they were activated by blue light irradiation. The reasons for these differences in DNA-binding abilities and photoactivation are explored. Using the results from the characterization of these constructs, proposals are also made to develop more robust genetically encoded photoactivatable DNA-binding proteins of the same type.