Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

by Siu-wang Lau. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 121-127). / Abstracts in English and Chinese. / Contents page / Acknowledgement --- p.ii / Abstract --- p.iii / Abbreviations --- p.v / Contents --- p.vi / Introduction --- p.1 / Chapter Part I / Chapter 1 --- Principle of Fourier transform infrared spectroscopy (FTIR) --- p.9 / Chapter 2 --- Experimental --- p.15 / Chapter 2.1 --- Method of calibration curve for FTIR --- p.15 / Chapter 2.2 --- Method of standard addition for FTIR 18 、 / Chapter 3 --- Results --- p.19 / Chapter 3.1 --- Results of the method of calibration curve for FTIR --- p.26 / Chapter 3.2 --- Results of the method of standard addition for FTIR --- p.34 / Chapter 4 --- Discussion --- p.37 / Chapter 5 --- Interferences between the major components when two standard chemicals were considered each time (mixture of two standard compounds) --- p.41 / Chapter 5.1 --- Introduction --- p.41 / Chapter 5.2 --- Procedures --- p.43 / Chapter 5.3 --- Results --- p.47 / Chapter 5.4 --- Discussion --- p.80 / Chapter 6 --- Interferences between the major components when four standard chemicals were considered each time (mixture of four standard compounds) --- p.83 / Chapter 6.1 --- Introduction --- p.83 / Chapter 6.2 --- Experimental --- p.83 / Chapter 6.3 --- Results --- p.85 / Chapter 6.4 --- Conclusion --- p.89 / Chapter 7 --- Discussion --- p.90 / Chapter Part II / Chapter 1 --- Introduction --- p.92 / Chapter 2 --- Principle of flame emission spectroscopy (FES) --- p.92 / Chapter 3 --- Introduction of the analysis of total calcium by FES --- p.94 / Chapter 4 --- Experimental --- p.104 / Chapter 4.1 --- Methods of digestion --- p.104 / Chapter 4.2 --- Methods of oxidation --- p.105 / Chapter 4.3 --- Calibration of standard --- p.106 / Chapter 5 --- Results --- p.107 / Chapter 6 --- Discussion --- p.112 / Chapter Part III / Chapter 1 --- Estimation of total calcium by FTIR --- p.113 / Chapter 2 --- Experimental --- p.113 / Chapter 3 --- Results --- p.115 / Chapter 4 --- Discussion --- p.119 / Chapter Part IV --- Conclusion --- p.120 / Chapter Part V --- References --- p.121 / Appendices / Appendix 1 Example of the calculation of analyte content by the method of calibration curve --- p.128 / Appendix 2 Examples of the calculations of the analytes by the method of standard addition --- p.130 / Appendix 3 IR spectrum of a mixture of four standard chemicals --- p.132 / Appendix 4 IR spectrum of a sample --- p.133

Thesis (Ph. D.)--Ohio State University, 2006. / Full text release at OhioLINK's ETD Center delayed at author's request

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 90-93).

Orientador: Simonides Consani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:13:14Z (GMT). No. of bitstreams: 1 Schneider_LuisFelipeJochims_M.pdf: 587883 bytes, checksum: b9a6c32d96447cdbb96df9d09a9eaa16 (MD5) Previous issue date: 2005 / Resumo: Nos últimos anos diversas fontes de luz fotoativadoras de compósitos odontológicos têm sido introduzidas no mercado, cada qual com suas características. No entanto, muitas dúvidas permanecem com relação ao possível aumento de temperatura durante a fotoativação de compósitos restauradores odontológicos. Assim, neste estudo procurou-se avaliar a influência de fatores envolvidos durante o procedimento de fotoativação sobre o grau de elevação da temperatura e suas conseqüências em algumas propriedades dos compósitos fotoativados. Visando o melhor entendimento, a pesquisa foi dividida em três trabalhos. O primeiro trabalho verificou a variação da temperatura durante a fotoativação, com três diferentes fontes de luz, em incrementos de 2 e 3mm utilizando dois compósitos restauradores. A maior espessura de compósito (3mm) contribuiu para a diminuição estatisticamente significante (p<0,05) da variação da temperatura. O fator fonte de luz também produziu diferença estatística significante na variação da temperatura durante a fotoativação (p<0,05), onde a fonte halógena produziu valores superiores de aumento de temperatura quando comparada às fontes de luz emitida por diodos (LED) e arco de plasma de Xenônio (PAC). O fator compósito influenciou no aumento de temperatura observada. O segundo trabalho verificou o aumento de temperatura durante a fotoativação e a dureza, quando utilizadas três fontes de luz e dois compósitos restauradores. A fonte de luz LED produziu menor valor de aumento de temperatura, independente do compósito utilizado ¿ Filtek Flow ou Filtek Z250 ¿quando comparada à fonte de luz halógena, porém com valores de dureza Knoop semelhantes. A luz emitida por arco de plasma de Xenônio gerou os menores valores de elevação da temperatura. Entretanto, esta fonte de luz produziu os menores valores de dureza Knoop quando comparada às fontes LED e halógena. O terceiro trabalho verificou a temperatura e o grau de conversão quando utilizadas três fontes de luz, com tempo de fotoativação indicado pelos fabricantes, tempo necessário para igualar a densidade de energia total e tempo necessário para igualar a densidade de energia na faixa entre 450-490nm do espectro eletromagnético. Quando utilizado o tempo preconizado pelos fabricantes, as fontes de luz halógena e LED produziram valores de grau de conversão estatisticamente semelhantes. Entretanto, o aumento de temperatura gerado pelo LED foi inferior. Quando a densidade total de energia foi padronizada, a fonte PAC produziu grau de conversão similar às demais fontes. Quando a densidade de energia foi igualada na faixa entre 450-490nm, a fonte de luz LED produziu valoresde grau de conversão estatisticamente superiores aos produzidos pela fonte PAC. A fonte PAC produziu os menores valores de variação da temperatura, independente do tempo de exposição / Abstract: In the last years several light curing units (LCUs) have been launched in the market, each one with its own characteristics. However, there are still many doubts concerning the possible temperature increase during the photo-activation of restorative dental composites. Thus, the aim of this study was to evaluate the influence of some factors involved during the photo-activation procedure on the degree of temperature increase and its consequences in some properties of photoactivated composites. For a better understanding, the research was divided in three works. The first work verified the temperature increase during photoactivation using three different LCUs in increments of 2 and 3mm using two composites. The thicker composite (3mm) contributed to a statistically significant decrease (p<0.05) in temperature increase. The light source factor also produced significant statistical difference in the temperature increase during photo-activation (p<0.05), where the halogen LCU produced higher values of temperature increase when compared to the sources LED and PAC (p <0.05). Composite type presented a complex behavior influencing temperature increase observed herein. The second work verified the temperature increase during photo-activation and the hardness using three LCUs and two restorative composites. The LED LCU produced lower values of temperature increase, regardless the composite used - Filtek Flow or Filtek Z250 - when compared with the halogen LCU, but with similar Knoop hardness values. The PAC LCU generated the lowest values of temperature increase. However, this light source produced the lowest Knoop hardness values regardless composite used. The third work verified the temperature increase and the degree of conversion using three LCUs, with adequate photo-activation time as recommended by the manufacturer - the amount of time needed to equal the total energy density and the amount of time needed to equal the energy density in the range between 450-490nm of the electromagnetic spectrum. When the time recommended by the manufacturer was used, the light sources QTH and LED produced statistically similar values of degree of conversion. However, the temperature increase generated by LED LCU was lower. When the total energy density was standardized, the PAC LCU produced a degree of conversion similar to the other LCUs. When the energy density was equaled in range between 450- 490nnm, the LED LCU produced values of degree of conversion statistically higher to the ones produced by the PAC LCU. The PAC LCU produced the smallest values of temperature increase, regardless the exposure time / Mestrado / Materiais Dentarios / Mestre em Materiais Dentários

In the manufacturing process of float glass often atmospheric pressure chemical vapour deposition (APCVD) reactors are integrated on-line for the deposition of functional thin solid films. Such functional films have applications in architectural glass, flat panel displays and solar cells. As glass moves downstream in the process, the thin film is deposited at temperatures between 500 to 700°C. The high temperatures make it difficult to monitor the deposition process and thin film quality control is commonly done at the end of the line or at lower temperatures. A time delay therefore exists between the point of thin film deposition and subsequent quality control, which can lead to large quantities of defective product being produced before faults are detected. It is therefore desirable to monitor in the APCVD reactor for rapid feedback of unexpected deviations from desired process conditions, reaction progress and fault detection. High uniformity of film properties across the substrate are important, but APCVD reactors are often empirically designed and the detailed chemical reaction mechanism is unknown. This leads to inefficient gas flow patterns and precursor utilization as well as difficulties in the design of new reactors. The APCVD deposition of tin oxide from the mono-butyl-tin tri-chloride (MBTC) is an example of such a process. Optical monitoring instruments in-situ and in-line on the APCVD reactor provided rapid feedback about process stability and progress non-invasively. Near infrared diode laser absorption spectroscopy (NIR-LAS) monitored the concentration of the reaction species hydrogen chloride (HCl) in-situ and spatially in the coating zone. A mid-infrared grating absorption spectrometer (IR-GAS) with novel pyro-electric array detector monitored the concentration of precursor entering the coating system simultaneously. In combination these instruments provide the means for rapid process feedback. Fourier transform infrared absorption spectroscopy (FTIR) was used to investigate the unknown decomposition pathway of the precursor to find the yet unknown key tin radical that initiates film growth. Stable species forming during MBTC decomposition over a temperature range of 170 to 760°C were investigated but the tin intermediate remains unknown. Computational fluid dynamics (CFD) is routinely employed in research and industry for the numerical simulation of CVD processes in order to predict reactor flow patterns, deposition rates, chemical species distribution or temperature profiles. Two and three dimensional models with complex geometries and detailed reaction models exist. A three dimensional computational fluid dynamics (CFD) model of the used APCVD reactor was built using the Fluent CFD software. The numerical simulation included a chemical model that predicted qualitatively the chemical species distribution of hydrogen chloride in the gas phase. This was confirmed through comparison with NIR-LAS results. Design shortcomings due to inefficient flow patterns were also identified. In combination the optical tools developed provide the means for safe and efficient manufacturing of thin films in APCVD reactors. CFD simulations can be used to increase precursor utilization and film uniformity in the development of new reactor designs.

Resumo: O objetivo deste trabalho, dividido em três estudos, foi avaliar: (1) a influência da utilização de diferentes fontes de luz e métodos de fotoativação sobre o grau de conversão e a contração de polimerização de uma resina composta nanoparticulada; (2) a influência da utilização dos diferentes métodos de fotoativacao, disponibilizados por aparelhos LED de 2a geração, sobre a contração volumétrica das resinas compostas microhíbrida e nanopartículada e (3) as propriedades térmicas e o grau de conversão das resinas compostas microhíbrida e nanopartículada, submetidas aos diferentes métodos de fotoativação disponibilizados por aparelhos LED de 2a geracao. No primeiro estudo, o grau de conversão (GC) foi avaliado pelo metodo da espectroscopia infravermelha transformada de Fourier (FT-IR) e as forças de contração (C) mensuradas em máquina de ensaios universal (EMIC). Os dados obtidos para o GC e C foram analísados estatísticamente pelo teste da análise de variancia (ANOVA), sendo que para as forças de contração, a correção de Welch e o teste Tamhane também foram empregados. No segundo estudo, a contração volumétrica foi avaliada por um mecanismo de vídeo e imagem (AcuvolR/Bisco) e os dados obtidos foram análisados estatísticamente pelos testes ANOVA e Tukey. No terceiro estudo, o método da calorimetria exploratória diferencial foi empregado para avaliar a temperatura de transição vitrea (Tg) e de degradação dos materiais e o GC por FTIR. Os dados relativos ao GC foram análisados estatísticamente pelos testes ANOVA e Tukey. Os resultados demonstraram diferenças na contração de polimerização de acordo com o método de fotoativação empregado. No primeiro e segundo estudos, mesmo empregando diferentes metodologias, o método de fotoativação contínuo apresentou os maiores valores de contração. Por outro lado,o GC não... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this work, divided into three studies, was evaluate: (1) the influence of different light sources and photo-activation methods on degree of conversion and polymerization shrinkage of a nanocomposite resin; (2) the influence of different photo-activation methods, available by the 2nd generation LED light-curing units, on the volumetric shrinkage of microhybrid and nanocomposite resins and (3) thermal properties and degree of conversion of microhybrid and nanocomposite resins submitted to different photo-activation methods available by 2nd generation LED light-curing units. In the first study, degree of conversion (DC) was evaluated by Fourier transform infrared spectroscopy (FT-IR) and shrinkage forces (S) were measured in a universal testing machine (EMIC). The data obtained for DC and S were analyzed by Analysis of Variance test (ANOVA) and for S Welch's correction and Tamhane's tests were also employed. In the second study, volumetric shrinkage was evaluated by video-imaging device (AcuvolR/Bisco) and data were analyzed by ANOVA and Tukey's test. In the third study, differential scanning calorimetry was used in order to observe glass transition temperature (Tg) and degradation peak of the materials and DC was evaluated for FT-IR. The DC data were analyzed by ANOVA and Tukey's test. The results showed differences in the polymerization shrinkage according to photo-activation method employed. In the first and second studies, the continuous photo-activation methods presented the highest values for shrinkage even though different methodologies were used to assess. Moreover, DC was not influenced by the photo-activation method but was influenced by light sources. The lowest DC values were observed for halogen light-curing unit. In the second study beyond the influence of the photo-activation... (Complete abstract click electronic access below) / Orientador: Marcelo Ferrarezi de Andrade / Coorientador: Alessandra Nara de Souza Rastelli / Banca: Silmara Aparecida Milori Corona / Banca: Denise Pedrini / Banca: Osmir Batista de Oliveira Junior / Banca: José Roberto Cury Saad / Doutor

Orientador: Regina Maria Puppin-Rontani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-19T23:12:12Z (GMT). No. of bitstreams: 1 Inagaki_LucianaTiemi_M.pdf: 1637103 bytes, checksum: be2b43c0e245a141e813657feff8bca9 (MD5) Previous issue date: 2012 / Resumo: Esta dissertação foi dividida em dois capítulos: Capítulo 1 avaliou a atividade antimicrobiana de misturas não polimerizadas e polimerizadas por meio da mensuração da zona de inibição após difusão em ágar (Pour Plate); e determinou a Concentração Inibitória Mínima (CIM) e Concentração Mínima Bactericida (CMB) de misturas resinosas experimentais. Os ensaios microbiológicos foram realizados em triplicata, sendo o digluconato de clorexidina 0,12% utilizado como referência (antibacteriano padrão) e o infiltrante Icon® (DMG) utilizado como controle comercial. Cepas de Streptococus mutans UA159 e Lactobacillus acidophilus LYO50DCU-S foram utilizadas em todos os testes. Capítulo 2 determinou o grau de conversão e a dureza Knoop das misturas experimentais tendo como controle comercial o infiltrante Icon®. As misturas utilizadas nos ensaios experimentais foram: TEGDMA, TEGDMA/CHX 0,1%, TEGDMA/CHX 0,2%, TEGDMA/UDMA, TEGDMA/UDMA/CHX 0,1%, TEGDMA/UDMA/CHX 0,2%, TEGDMA/BisEMA, TEGDMA/BisEMA/CHX 0,1% e TEGDMA/BisEMA/CHX 0,2%. Os testes estatísticos utilizados nos ensaios de ambos os estudos foram ANOVA um critério seguido por teste de Tukey, e teste-t para comparação entre os grupos (p<0,05). O CIM e CMB mostraram que as misturas demonstraram ter atividade antibacteriana com baixas concentrações de CHX para as duas cepas bacterianas testadas. Antes da polimerização, a atividade antibacteriana da maioria das misturas foi maior que o Icon®. Para S. mutans, as misturas TEGDMA/BisEMA/CHX 0,1% e TEGDMA/BisEMA/CHX 0,2%, a concentração de CHX foi fator relevante para aumentar a zona de inibição. Após a polimerização, a mistura TEGDMA/UDMA/CHX 0,1% mostrou maior zona de inibição para S. mutans. Para o L. acidophilus, a atividade antibacteriana antes da polimerização foi maior para TEGDMA/CHX 0,2% e TEGDMA/UDMA/CHX 0,1%, independente da concentração de CHX. Após a polimerização, todas as misturas experimentais e Icon® não apresentaram atividade antibacteriana. Quando as zonas de inibição das misturas polimerizadas e não polimerizadas foram comparadas, a maioria das misturas não polimerizadas apresentaram maior efeito antibacteriano para as duas cepas. A adição de CHX não reduziu o DC das misturas; contudo, para as misturas a base de TEGDMA, o CHX influenciou positivamente e causou o aumento do DC. As misturas TEGDMA/UDMA, TEGDMA/UDMA/CHX 0,1% e TEGDMA/UDMA/CHX 0,2% apresentaram os maiores valores de DC e as misturas TEGDMA/BisEMA, TEGDMA/BisEMA/CHX 0,1% e TEGDMA/BisEMA/CHX 0,2% os menores valores de DC. Todas as misturas apresentaram valores de DC menores que o Icon®. Em relação à microdureza, TEGDMA/UDMA e TEGDMA/UDMA/CHX 0,2% apresentaram os maiores valores de dureza Knoop. A adição de CHX não afetou a dureza de superfície das misturas experimentais. Quando comparadas ao Icon®, todas as misturas apresentaram maior dureza Knoop. Assim, dentre as misturas avaliadas, a mistura TEGDMA/UDMA/CHX 0,1% apresentou os melhores resultados para o DC e para a atividade antibacteriana após polimerização / Abstract: This dissertation was divided into two chapters: Chapter 1 aimed to evaluate the antimicrobial activity of cured and uncured resin blends though measurement of inhibition zone using agar diffusion (Pour Plate), Minimal Inhibiting Concentration (MIC) and Minimum Bactericidal Concentration (MBC). For microbiological assays, that were performed in triplicate, the 0.12% chlorhexidine digluconate solution was used as reference standard antimicrobial and infiltrant Icon® (DMG) was used as commercial control group. Streptococcus mutans UA159 and Lactobacillus acidophilus LYO50DCU-S strains were selected for all assays. Chapter 2 aimed to determine DC and Knoop hardness of mixtures having Icon® as commercial control group. Mixtures were set as follow: TEGDMA, TEGDMA/0.1% CHX, TEGDMA/0.2% CHX, TEGDMA/UDMA, TEGDMA/UDMA/0.1% CHX, TEGDMA/UDMA/0.2% CHX, TEGDMA/BisEMA, TEGDMA/BisEMA/0.1% CHX and TEGDMA/BisEMA/0.2% CHX. Data obtained from all mixtures and Icon® were submitted to one-way ANOVA, followed by Tukey test, and in order to compare the groups t-test was used (p<0.05). The MIC and MBC tests showed that the mixtures demonstrated antibacterial activity in low concentrations of CHX against both of strains. Analyzing antibacterial activity against S. mutans before light curing process, the most of blends provided larger inhibition zones than Icon®, and for TEGDMA/BisEMA/0.1% CHX and TEGDMA/BisEMA/0.2% CHX the CHX concentration was significant factor to increase the inhibition zones. After light curing, the mixture TEGDMA/UDMA/0.1% CHX showed the highest inhibition zone against S. mutans. Analyzing antibacterial activity against L. acidophilus before light curing, the addition of CHX to the blends, regardless concentration, provided inhibition zones and TEGDMA/0.2% CHX and TEGDMA/UDMA/0.1% CHX showed the highest antibacterial effects. After light curing, no significant difference between all experimental blends, including Icon®, was observed. When the inhibition zones of uncured and cured blends were compared, the major of uncured blends demonstrate grater antimicrobial activity to both strains. The addition of CHX didn't reduce the DC of experimental infiltrants blends, but CHX had positive influence for TEGDMA neat monomer, increasing DC. TEGDMA/UDMA, TEGDMA/UDMA/0.1% CHX and TEGDMA/UDMA/0.2% CHX showed the highest DC than other mixtures, while TEGDMA/BisEMA, TEGDMA/BisEMA/0.1% CHX and TEGDMA/BisEMA/0.2% CHX the lowest DC. All mixtures showed significant lower values of DC than commercial infiltrant. Concerning hardness, TEGDMA/UDMA and TEGDMA/UDMA/0.2% CHX showed the highest Knoop hardness values. The addition of CHX didn't change surface hardness of mixtures. When Knoop hardness values of nine mixtures were compared with Icon®, all mixtures showed significant higher values than commercial infiltrant. Thus, among the experimental resin mixtures evaluated, TEGDMA/UDMA/0.1% CHX showed the best results to DC and to antimicrobial effect after polymerization / Mestrado / Odontopediatria / Mestre em Odontologia

This thesis focuses on the utilisation of mid-infrared techniques in technological atmospheric pressure, non-thermal plasma (NTP) diagnostics. Two mid-infrared techniques were demonstrated in this work namely laser absorption and Fourier transform infrared (FTIR) spectroscopy. The performance of external-cavity quantum cascade laser (EC-QCL), a relatively new laser type with broad tuning capability was also demonstrated as potential diagnostics tool for technological NTP applications. A dual plate dielectric barrier discharge (DBD) and a packed-bed NTP reactor were designed and fabricated to perform plasma process. Quantitative analysis of the laser absorption and FTIR spectroscopy techniques for gas detection were validated by using standard gas samples. Real-time CO monitoring by means of in-situ laser absorption spectroscopy measurements were performed for gas phase diagnostics in the decomposition of TEOS by means of plasma-enhanced chemical vapour deposition (PE-CVD) and in CO2 reforming of CH4 by means of NTP. In-line FTIR measurements simultaneously recorded the gas spectrum at the exhaust of the plasma reactors. Information from both measurements was found to provide useful information on the plasma processes and chemistry for the NTP applications. Finally, wavelength stability and linearity performance of a broad tuning range EC-QCL were evaluated by using the Allan variance technique. (LOD) at SNR = 1 was estimated to be ~ 2 ppm, achieved under atmospheric pressure, at the room temperature, and a path length of 41 cm for NO detection produced from the decomposition of dichloromethane (DCM) by means of NTP.