Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2003. / Includes bibliography.

Thesis (Ph. D.)--University of Chicago, Dept. of Chemistry, June 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (PH. D.)--University of Minnesota, 1929. / Cover-title. Vita. The first article is from the Journal of physical chemistry, v. 33, no. 3, March 1929; the second is Preprint 59-5 of the Electrochemical society.

Thesis (Ph. D.)--University of Chicago, Dept. of Chemistry, June 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 92-94). Also available in electronic version.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). "April 2006." Includes bibliographical references (leaves 101-122). Also available via the World Wide Web.

Made available in DSpace on 2014-10-09T12:28:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:06Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo

Orientador: Andréa Abi Rached Dantas / Resumo: Os objetivos deste estudo foram avaliar os efeitos da utilização de antioxidantes em solução na dentina de dentes tratados endodonticamente, por meio da avaliação da resistência das coroas dentais à fratura, mensuração da formação intradentinária da camada híbrida e sua repercussão sobre a resistência de união de um sistema adesivo condiciona-e-lava. No primeiro experimento, foram utilizados sessenta incisivos bovinos endodonticamente tratados, distribuídos em sete grupos (n=10). Sendo, G1: controle, somente restaurado com resina composta, G2: clareado com peróxido de hidrogênio 38% e restaurado imediatamente, G3: clareado, tratado com ascorbato de sódio 10% e restaurado, G4: clareado, tratado com alfatocoferol e restaurado; G5: clareado, tratado com cranberry 5% e restaurado; G6: clareado, tratado com capsaícina 0,0025% e restaurado. Os espécimes foram submetidos ao teste mecânico de resistência à fratura após 24h. No segundo experimento, foram utilizados sessenta incisivos bovinos tratados endodonticamente, divididos em seis grupos (n=10), similar ao experimento 1, entretanto sem o grupo de controle negativo. Todos tratamentos foram similares aos do experimento 1. Somente a porção coronária seccionada no sentido vestíbulo-lingual de cada espécime foi utilizada para análise em microscópio laser confocal, com aumento de 1024x. No terceiro experimento, a superfície vestibular de cada espécime foi desgastada e incluída em resina acrílica autopolimerizável em cilindro de PVC. Os... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the effects of antioxidants solutions on fracture resistance, hybrid layer formation and bond strength of adhesive system in endodontically-treated teeth. First study used 60 endodontically-treated bovine incisors randomly divided into seven groups (n = 10): G1: control, restored with composite resin; G2: bleaching with 38% hydrogen peroxide and immediately restored; G3: bleaching, 10% sodium ascorbate and restoration; G4: bleaching, 10% alphatocopherol and restoration, G5: bleaching, 5% cranberry and restoration, G6: bleaching, 0.002% capsaicin and restoration. The specimens were subjected to fracture resistance mechanical testing. Second study used 60 endodontically-treated bovine incisors randomly divided into six groups (n = 10): G1: restoration; G2: bleaching and immediate restoration; G3: bleaching, 10% sodium ascorbate and immediate restoration; G4: bleaching, 10% alphatocopherol and immediate restoration, G5: bleaching, 5% cranberry and restoration, G6: bleaching, 0.002% capsaicin and restoration. Bleaching protocol and antioxidant application were similar to experiment 1. Coronal portion was sectioned at buccolingual direction and analyzed by confocal laser microscope at 1024X magnification. Third study used 60 specimens randomly divided into six groups (n = 10), similar to protocols described in experiment 2. Buccal surface of each specimen was ground and included in acrylic resin in the PVC cylinder. Composite resin cylinders were made and bond... (Complete abstract click electronic access below) / Doutor

L’objectif de ce travail est donc de développer un procédé industriel, propre, de production de cellulose pure à partir de pâte kraft non blanchie, basé sur la catalyse du peroxyde d’hydrogène et utilisant si nécessaire des traitements complémentaires sans chlore. A cet effet, deux approches sont adoptées : (i) délignification de pâte kraft avec du peroxyde d'hydrogène et (ii) purification de la pâte à la soude et ozone. La réaction du système cuivre-phénanthroline / peroxyde d'hydrogène avec un composé modèle de lignine non phénolique, l’alcool vératrylique a été étudié. L’effet du catalyseur sur la délignification et sur la dégradation des hydrates de carbone a été examiné. La purification des pâtes ainsi obtenues par une extraction alcaline à froid ainsi qu’un stade de blanchiment final à l’ozone. Enfin, il a été montré que les moléculaires des celluloses (DMM) des celluloses produites étaient comparables à celles des pâtes au bisulfite acide où pré-hydrolyse krafts utilisés pour les applications viscose. / This research work describes the production of pure cellulose from hardwood kraft pulp by an environmental friendly process. To achieve this goal two main strategies are approached: (i) pulp deilgnification and (ii) pulp purification. For pulp delignification hydrogen peroxide is chosen with copper phenanthroline complex. Initially oxidation efficiency of copper phenanthroline with hydrogen peroxide is studied with lignin model compound, i.e., veratryl alcohol. Then its delignification effect is studied with oxygen delignified kraft pulp. After delignification pulp is purified by cold caustic extraction and ozone treatment. With this approach pure cellulose is produced, whose chemical properties are similar the different grades of pure celluloses available. By this process a wide rang of pure celluloses can be produced for different products.

Submitted by Marcos Akio Ono (dr.marcosono@gmail.com) on 2018-08-22T19:44:11Z No. of bitstreams: 1 Dissertação para impressão.pdf: 1029289 bytes, checksum: a1d633fffa89289013b2b320e32ecbeb (MD5) / Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2018-08-24T13:48:01Z (GMT) No. of bitstreams: 1 ono_ma_me_sjc.pdf: 1029289 bytes, checksum: a1d633fffa89289013b2b320e32ecbeb (MD5) / Made available in DSpace on 2018-08-24T13:48:01Z (GMT). No. of bitstreams: 1 ono_ma_me_sjc.pdf: 1029289 bytes, checksum: a1d633fffa89289013b2b320e32ecbeb (MD5) Previous issue date: 2018-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo desse estudo foi avaliar o efeito da tiouréia (T) como um catalisador químico na eficiência clareadora do peróxido de hidrogênio. Para tal, foram misturados dentro de um frasco Becker uma associação de cromógenos (vinho tinto, tabaco e café), peróxido de hidrogênio em quantidade suficiente para que se obtivesse uma concentração final de 35%, solução de hidróxido de sódio para o ajuste de pH e concentrações variadas de tiouréia como catalisador químico. Foram testadas cinco diferentes concentrações de tiouréia (0,05%, 0,125%, 0,25%, 0,375% e 0,425%), sendo pH inicial de todas as associações ajustado para 7. Um grupo controle sem catalisador também foi avaliado. Após a mistura, a cor inicial das soluções e a concentração de peróxido foram avaliados empregando, respectivamente, espectrofotômetro colorimétrico e um titulador automático. As leituras foram repetidas após 30 minutos. A mudança na variação de cor (∆E) e o percentual de queda na concentração de peróxido após a reação foram analisados estatisticamente, assim como a correlação entre as duas variáveis foi avaliada. Os dados foram analisados utilizando os testes de ANOVA a um fator e Tukey. Diferenças significavas foram observadas para a variação de cor (p=0,0001) e para a concentração de H2O2 (p=0,0001). Os resultados do teste de Tukey para o ∆E foram: Controle (20,68 ± 2,14)a, T 0,05% (25,24±3,71)a, T 0,125% (56,23 ± 5,92)e, T 0,25% (50,01±5,04)d, T 0,375% (43,29± 3,24)c, T 0,425% (37,65± 3,28)b. Os resultados do teste de Tukey para o percentual de redução da concentração foram: Controle (0,59±0,53)a, T 0,05% (0,70±0,56)a, T 0,125% (4,76±1,28)c, T 0,25% (4,26±1,57)c, T 0,375% (2,50±0,72)b, T 0,425% (1,51±0,81)a. Concluiu-se que o uso da tiouréia aumentou significativamente o efeito clareador e o consumo do peróxido de hidrogênio durante a reação, com uma forte correlação positiva entre eles, tendo o máximo efeito sido constatado em a uma concentração 0,125% de tiouréia. / The aim of this study was to evaluate thiourea (T) effectiveness as a chemical catalyst on hydrogen peroxide bleaching efficiency. For that, an association of chromogens (red wine, tobacco and coffee) were mixed in a Becker bottle with hydrogen peroxide in sufficient amount to obtain a final concentration of 35%, sodium hydroxide solution for pH adjustment and a range of different concentrations of thiourea as a chemical catalyst. Five different concentrations of thiourea were tested (0.05%, 0.125%, 0.25%, 0.375% and 0.425%), with the pH adjusted to 7. A control group without a catalyst was also evaluated. After mixing, the baseline color of the solutions and the peroxide concentration were evaluated using a colorimetric spectrophotometer and an automatic titrator. The readings were repeated after 30 minutes. The color change (ΔE) and the percentage of peroxide concentration reduction after the reaction were statistically analyzed, as well as the correlation between the two variables. Data were analyzed using one-way ANOVA and Tukey´s test. Significant differences were observed for the color change (p = 0.0001) and for the H2O2 concentration (p = 0.0001). The results of the Tukey´s test for ΔE were: Control (20.68 ± 2.14)a, T 0.05% (25.24 ± 3.71)a, T 0.125% (56.23 ± 5,92)e, T 0.25% (50.01 ± 5.04)d, T 0.375% (43.29 ± 3.24)c and T 0.425% (37.65 ± 3.28)b. The results of the Tukey´s test for the percentage of peroxide reduction were: Control (0.59 ± 0.53)a, T 0.05% (0.70 ± 0.56)a, T 0.125% (4.76 ± 1.28)c, T 0.25% (4.26 ± 1.57)c, T 0.375% (2.50 ± 0.72)b, T 0.425% (1.51 ± 0.81)a. It was concluded that thiourea significantly increased the bleaching effect and the consumption of hydrogen peroxide during the reaction, with a strong positive correlation between them, with a maximum effect when 0.125% of thiourea was used. / CAPES / Demanda Social 02/2016 a 08/2017