Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008

Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008

Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008

Orientadores: Priscila Gava Mazzola, Patrícia Moriel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T05:30:45Z (GMT). No. of bitstreams: 1 Romanhole_RodrigoCollina_M.pdf: 2407995 bytes, checksum: a3fd76e8329a74f761c010fad33c4377 (MD5) Previous issue date: 2014 / Resumo: Filtros solares são moléculas com capacidade de absorver e/ou refletir a radiação UVA e UVB, evitando assim que esta radiação alcance a epiderme ou até mesmo a derme, porém alguns filtros podem apresentar instabilidade quando absorvem a radiação, com consequente perda desta função. A fotoinstabilidade após a exposição à radiação UV é bem conhecida e descrita, porém não existem muitos dados relacionando a estabilidade destes filtros após a irradiação de luz fluorescente emitida pelas lâmpadas comerciais presentes em lares e escritórios. O presente estudo propõe avaliar a fotoestabilidade de produtos comerciais com FPS 30, após irradiação UV e também após a irradiação fluorescente, correlacionando o comportamento de cada produto frente aos diferentes tipos de radiação. A metodologia aplicada é in vitro, sendo que os produtos testados foram aplicados em duas diferentes placas de polimetilmetacrilato Polimetil metacrilato (PMMA) e irradiados por um simulador solar com filtros específicos para UVA/B e por uma fonte de luz fluorescente comercial. De acordo com os resultados obtidos, foi observado que a placa de PMMA utilizada pode influenciar nos resultados e todas as amostras testadas apresentaram um comportamento fotoestável quando expostos à radiação ultravioleta ou fluorescente, ou seja, não apresentaram redução na sua capacidade de absorção da radiação UVA/B mesmo após doses de radiação bem elevadas. Estes resultados demonstram que as amostras testadas apresentaram um comportamento bastante estável em diversas situações em que a população está exposta no dia a dia / Abstract: Sunscreens are molecules with ability to absorb and/or reflect the UVA and UVB radiation, thereby preventing radiation that reaches the epidermis or dermis even though some filters can be unstable when they absorb radiation, with consequent loss of its function. The photostability after exposure to UV radiation is well known and described, but there are not many data correlating the stability of these filters after fluorescent light irradiation, emitted by commercial lamps present in homes and offices. This study proposes to assess the photostability of commercial products SPF 30 after artificial UV irradiation and also after the fluorescent radiation, correlating the behavior of each product against different types of radiation. The methodology applied was in vitro, and the products tested were applied on two different plates of polymethyl methacrylate (PMMA) and irradiated by a solar simulator with specific filters for UVA/B and a fluorescent light source commercial. According to the results, the plate can play an important role in the photostability data and all samples tested presented a similar photostable behavior when exposed to UV or fluorescent light, or showed no reduction in its capacity for absorption of UVA/B even after higher doses of radiation. These results demonstrate that the samples tested presented a very stable behavior in various situations in which the population is exposed on a daily basis / Mestrado / Ciencias Biomedicas / Mestre em Ciências Médicas

[pt] O objetivo deste projeto foi a montagem de um sistema que permitisse a caracterização de novos materiais em forma de filmes finos para aplicações em sistemas com detectores de UV, concentrando a nossa pesquisa na caracterização da radiação emitida por alguns filmes finos irradiados com um feixe de elétrons. A utilização de uma Micro-Channel Plate (MCP) nos direcionou para a escolha dos materiais catodoluminescentes que deveriam ser depositados como filmes. Este tipo de detector é sensível a fótons na faixa do ultravioleta de vácuo (VUV) e dos raios-X e, portanto, a escolha deveria recair em materiais cuja catodoluminescência ocorresse nessas regiões do espectro eletromagnético. Um sistema foi montado em uma câmara de vácuo para a realização do estudo destes materiais através da incidência de elétrons (produzidos por um canhão de elétrons com energia variável de 0 a 400 eV) nos mesmos. Os materiais, uma vez irradiados com elétrons, emitem fótons na região do VUV, os quais são, por sua vez, detectados pela MCP. Paralelamente, foram realizadas deposições de filmes baseados em óxidos puros ou dopados (ZnO, ZnO:Eu, ZnO:Er) e filmes de LiYF4:Er+, nunca antes depositado. Para tanto foram utilizadas diferentes técnicas de deposição como a de feixe de elétrons e a de spin-coating. Foram realizadas duas séries de medidas destas amostras na câmara de vácuo, para detecção de emissão de fótons por transmissão e por reflexão a 90º. Percebe-se, através dos resultados obtidos, que os materiais dopados com Érbio possuem um forte pico de emissão em torno de 120 eV. Estes resultados preliminares indicam que é possível utilizar filmes dopados com Érbio como materiais catodoluminescentes na faixa do VUV. / [en] Our project was to build a system that would allow the characterization of new materials in the form of thin films for UV detectors applications. The main objective of our research was the characterization of the radiation emitted by electron-beam irradiated thin films. The use of a Micro Channel Plate detector (MCP) leaded us to choose certain cathodoluminescent materials that should be deposited as films. Since this kind of detector is sensitive to photons in the vacuum ultraviolet (VUV) and X-rays regions of the electromagnetic spectrum, our investigation was restricted to the materials which present cathodoluminescence in this region. Thin films based in pure or doped oxides (ZnO, ZnO:Eu, ZnO:Er) and LiYF4:Er+ were deposited. To accomplish this, different kinds of techniques were used, such as the electron-beam and the spincoating depositions. Once irradiated with electrons, these materials emit VUV photons, which are in turn detected by the MCP. For these purposes it was necessary to build an electron gun, with energy ranging from 0 to 400 eV, placed in a vacuum chamber, used for these experiments. Two series of measurements of the produced samples were performed in this vacuum chamber, and the photonic emission was detected by using transmission and reflection geometries. Our data show that, at the available incident energy range, the Erbium-doped materials have a strong emission peak around 120 eV. These preliminary results show that it is possible to use Erbium-doped films as VUV- cathodoluminescent materials

Je présente un nouveau modèle d'émission nébulaire de galaxies à formation d'étoiles, que j'ai développé en combinant un modèle récent de synthèse de populations stellaires avec un code classique de photoionisation. Je détaille les principales caractéristiques de ce nouveau modèle, comme le traitement sophistiqué des abondances individuelles et des déplétions sur les grains de poussière qui permet d'explorer de façon appropriée les signatures des rapports non solaires d'abondances de métaux, et donc les propriétés des galaxies chimiquement jeunes à l'époque de la réionisation. Je présente la grille exhaustive publique de modèles de photoionisation que j'ai créée, explorant de larges éventails de paramètres stellaires et interstellaires. Je décris la capacité des modèles à reproduire simultanément les caractéristiques observationnelles de galaxies à formation d'étoiles dans plusieurs diagrammes de rapports de raies ultraviolettes et optiques, et j'explore l'influence des différents paramètres ajustables des modèles sur les prédictions de rapports de luminosités de raies. Je décris également comment la combinaison de ces modèles avec des modèles de régions d'émission de raies étroites autour de noyaux actifs de galaxies, effectués avec le même code de photoionisation, permet de définir de nouveaux diagnostics de rapports de raies d'émission ultraviolettes et optiques pour distinguer la formation stellaire et l'activité nucléaire dans les galaxies. Enfin, je montre comment le nouveau modèle présenté dans cette thèse a déjà été utilisé pour interpréter avec succès les raies d'émission ultraviolettes et optiques de galaxies naines lentillées à des décalages spectraux entre 2-7. / I present a new model of nebular emission from star-forming galaxies, which I have developed by combining updated stellar population synthesis models with a standard photoionization code. I detail the main features of this new model, such as the recent advances in the theories of stellar interiors and atmospheres it incorporates to interpret the ionizing radiation from star-forming galaxies, and the careful treatment of individual abundances and depletion onto dust grains, which allows one to properly explore the signatures of non-solar metal abundance ratios, and then the properties of chemically young galaxies out to the reionization epoch. I present the public comprehensive grid of photoionization models I have computed, including full ranges of stellar and interstellar parameters. I describe the ability of the models to account simultaneously for observational trends followed by star-forming galaxies in several ultraviolet and optical diagnostic line-ratio diagrams, and I explore the influence of the various adjustable model parameters on predicted line-luminosity ratios. I also describe how the combination of this model with calculations of narrow-line emitting regions from active galactic nuclei computed using the same photoionization code allows one to define new ultraviolet and optical emission-line diagnostics to discriminate between star formation and nuclear activity in galaxies. Finally, I show how the new model presented in this thesis has already been used successfully to interpret the rest-frame ultraviolet and optical line emission of different types of high-redshift star-forming galaxies, mainly lensed dwarf star-forming galaxies at redshift between 2-7.

Le fluoroborate de calcium Ca5(BO3)3F (CBF) et l'aluminoborate d'yttrium YAl3(BO3)4 (YAB) ont été étudiés pour respectivement la génération de 3ème et 4ème harmonique de laser proche infrarouge tel que YAG :Nd émettant à 1064 nm. Dans l'optique d'améliorer la qualité cristalline du CBF, nous avons étudié les paramètres de sa synthèse par réaction à l'état solide et ceux de sa cristallogénèse par la méthode Czochralski. Les acceptances thermiques pour la génération de 2nde harmonique à 1064 nm en type I et II ont également été déterminés. Et un cristal de CBF a permis de générer une énergie de 131,4 µJ à 355 nm par génération de 3ème harmonique, soit un rendement de conversion de 6,1%. Concernant le YAB, le flux à base de LaB3O6 a été étudié pour sa croissance cristalline par la méthode TSSG : des cristaux de tailles centimétriques sans fracture, ni inclusion ont été obtenus. Les défauts structuraux des cristaux (stries de croissance, macles etc.) ont été analysés. Par ailleurs, des investigations sur la réduction carbothermique ont été menées pour limiter la pollution en fer des cristaux. Une énergie laser de 163 µJ a été obtenue par doublage de fréquence de 532 nm à 266 nm, soit un rendement de conversion de 14,7%. / Calcium fluoroborate Ca5(BO3)3F (CBF) and yttrium aluminum borate YAl3(BO3)4 were studied respectively for 3rd and 4th harmonic generation of near infrared laser as Nd:YAG laser emitting at 1064 nm. In order to improve the crystalline quality of CBF, solid state reaction parameters and crystal growth conditions by using Czochralski furnace were investigated. Thermal acceptances for second harmonic generation at 1064 nm for type I and II were determined. 131,4 µJ energy at 355 nm was obtained by 3rd harmonic generation, corresponding to a conversion efficiency of 6,1%. When it came to YAB, LaB3O6 based flux was investigated for its crystal growth by TSSG method: centimeter size, inclusion and crack free crystals were obtained. Structural defects of crystals (striations, twins etc.) were analyzed. Furthermore, carbothermal reduction investigation was carried out to limit iron pollution in crystals. Eventually 163 µJ at 266 nm were obtained by frequency doubling from 532 nm to 266 nm, corresponding to a conversion efficiency of 14,7%.

L’exposition au soleil, et donc aux rayons ultraviolets, est de plus en plus fréquente chez l’homme dans les pays occidentaux. En effet, les modes de vie ont fortement changé ces dernières années, avec pour résultat une augmentation non négligeable des loisirs en extérieur. Ceci a pour conséquence une augmentation de l’apparition des cancers cutanés, dont le pronostic de survie est souvent mauvais et l’issue fatale. De plus, les traitements associés à ces maladies sont lourds et n’agissent pas toujours de façon efficace. Les campagnes d’information et de prévention face aux dangers du soleil restent donc les principales mesures efficaces pour lutter contre le cancer cutané lié à une surexposition au soleil. La recherche de nouveaux produits permettant de protéger de manière efficace la peau des effets néfastes des rayons UV reste donc un défi permanent et primordial pour la recherche dans l’industrie cosmétique. <p><p> Dans un premier temps, le travail a consisté à développer des nouvelles formulations de produits solaires contenant des concentrations élevées en filtres UV, conditionnées sous forme d’aérosol, celles-ci valables pour le marché européen. Une émulsion E/H et une émulsion E/Si ont donc été réalisées. Elles contenaient au final 27% de filtres UV pour l’émulsion E/H et 16,5% de filtres UV pour l’émulsion E/Si, dont 4% de filtres inorganiques pour les deux types d’émulsion. Leur viscosité était de 6800 mPa.s pour l’émulsion E/H et de 2800 mPa.s pour l’émulsion E/Si. Ces formulations étaient stables lorsqu’elles étaient conservées pendant 2 mois à 40°C et également lorsqu’elles subissaient 5 cycles de température entre 5°C et 40°C. La mise en aérosol de ces émulsions a nécessité l’utilisation de 22% de gaz propulseur (mélange :butane, propane, isobutane). <p>La taille des gouttelettes étant un paramètre important de la caractérisation des aérosols pour le choix des matériaux à utiliser ainsi que pour sécurité afin d’éviter toute inhalation pulmonaire, l’influence de différents éléments sur celle-ci a été étudiée. Nous avons ainsi montré que la concentration en gaz, la viscosité, la présence ou non de filtres inorganiques ainsi que le choix des valves et diffuseurs utilisés jouent un rôle dans la taille des gouttelettes émises, celle-ci ne pouvant pas être inférieure à 30 µm de diamètre. La taille des gouttelettes émises était supérieure à 50 µm avec pas plus de 0.1% ayant une taille inférieure à 10 µm et maximum 25% des gouttelettes ayant une taille comprise entre 10 et 30 µm. <p><p> Les produits formulés contenaient de grandes quantités en filtres solaires, organiques et inorganiques (27% pour l’émulsion E/H et 16,6% pour l’émulsion E/Si), il était donc important de vérifier qu’aucun des filtres présents dans les émulsions ne passaient à travers la peau lors de l’application des produits solaires. En effet, ceux-ci doivent rester à la surface de l’épiderme afin de maintenir l’efficacité des produits solaires et d’éviter des effets néfastes systémiques éventuels en pénétrant la peau. Une étude in vitro utilisant de la peau humaine excisée et des cellules de diffusion de Franz nous a permis de constater que les filtres inorganiques présents dans les formulations restaient en surface de la peau, et seulement deux des filtres organiques (l’EMC et MBBT) présentaient un potentiel de pénétration cutanée négligeable et non nocif pour la santé humaine (maximum 1,21 µg/ml/cm2 pour EMC et maximum 0,14 µg/ml/cm2 pour MBBT). De plus, après 24 h d’expérience, plus de 50% des filtres restaient à la surface de la peau, ce qui permettait de maintenir l’efficacité des produits solaires. Afin de mener à bien cette étude, des méthodes analytiques pour l’analyse simultanée des filtres solaires organiques d’une part, par CLHP (Chromatographie Liquide Haute Performance), et inorganiques d’autre part, par ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry), ont été mises au point et validées. <p>Une étude in vivo non invasive, basée sur le prélèvement des couches successives du stratum corneum, a été réalisée par la suite. Cette dernière a été effectuée par la méthode du « tape stripping », qui utilise des disques adhésifs rigides, et sur 9 volontaires pendant une période de 8 h. Elle a permis de confirmer les résultats obtenus avec la méthode in vitro. Une bonne corrélation entre ces deux types d’étude a été observée. <p><p> Enfin, la dernière partie du travail a porté sur l’EMC, un des filtres organiques utilisé dans la plupart des produits solaires mis sur le marché et dans les émulsions E/H et E/Si formulées. Ce filtre présente une sensibilité à la lumière et aux rayons UV. L’encapsulation lipidique de celui-ci a donc été envisagée afin de produire des nanoparticules dont la matrice lipidique a pour but de protéger l’EMC contre une dégradation causée par les rayons UV. Trois lipides différents ont été investigués et ont montré des résultats positifs de protection vis-à-vis des rayonnements UV. En effet, après 2 h d’irradiation par les UV, une perte d’efficacité de 30% de l’EMC pur a été observée contre 10% à 21% pour l’EMC encapsulé par les différents lipides. De plus, les nanoparticules n’ont pas montré de potentiel d’augmentation de pénétration cutanée de l’EMC. <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

We analyse solar extreme ultraviolet (EUV) irradiance observed by the Solar EUV Experiment (SEE) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, and solar proxies (the F10.7 index, and Mg-II index), and compare their variability with the one of the global mean Total Electron Content (GTEC). Cross-wavelet analysis confirms the joint 27 days periodicity in GTEC and solar proxies. We focus on a comparison for solar minimum (2007-2009) and maximum (2013-2015) and find significant differences in the correlation during low and high solar activity years. GTEC is delayed by approximately 1-2 days in comparison to solar proxies during both low and high solar activity at the 27 days solar rotation period. To investigate the dynamics of the delay process, Coupled Thermosphere Ionosphere Plasmasphere electrodynamics model simulations have been performed for low and high solar activity conditions. Preliminary results using cross correlation analysis show an ionospheric delay of 1 day in GTEC with respect to the F10.7 index during low and high solar activity. / Wir analysieren vom Solar Extreme Ultraviolet Experiment (SEE) an Bord des Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) Satelliten gemessene solare EUV-Irradianzen, solare Proxies (den F10.7-Index und denMg-II-Index), und vergleichen deren Variabilität mit derjenigen des global gemittelten Gesamtelektronengehalts (GTEC). Kreuzwaveletanalysen bestätigen eine gemeinsame Variabilität im Periodenbereich der solaren Rotation (27 Tage). Wir vergleichen insbesondere den Zusammenhang während des solaren Minimums (2007- 2009) und Maximums (2013-2015), wobei signifikante Unterschiede der Korrelation zwischen solaren und ionosphärischen Parametern auftreten. Es tritt eine Verzögerung der Maxima und Minima von GTEC gegenüber denjenigen der solaren Proxies von einem Tag sowohl im solaren Minimum als auch im solaren Maximum auf.

Résumé : Cette thèse porte sur le rôle de deux expositions environnementales encore peu étudiées et pouvant influer sur l’incidence des hémopathies malignes (HME) de l’enfant : les rayons ultraviolets (UV) et les pesticides liés aux activités agricoles.Les leucémies (LA) et lymphomes de l’enfant sont les deux types principaux de HME et représentent respectivement environ 470 et 200 nouveaux cas par an en France. Leur prise en charge thérapeutique et leur survie ont fait d’immenses progrès, cependant la connaissance de leurs facteurs de risque est encore très partielle.Les études sur les effets des UV dans les cancers de l’enfant sont peu développées. Plusieurs méta-analyses récentes concluent à une augmentation du risque de LA chez l’enfant lors d’une exposition professionnelle ou domestique de la mère aux pesticides pendant la grossesse. L’exposition aux pesticides d’origine agricole a été moins étudiée, et les résultats sont hétérogènes.La première partie, écologique, de ce travail s’intéresse à l’exposition résidentielle aux UV. Une étude a été réalisée à partir des observations du Registre National des Hémopathies malignes de l’Enfant (RNHE) faites sur une longue période, entre 1990-2009 et sur l’ensemble de la France métropolitaine (9 082 cas de LA et 3 563 cas de lymphomes). Les données de l’exposition aux UV résidentiels étaient issues de la base EUROSUN. Une moyenne quotidienne d’exposition aux UV résidentiels sur l’ensemble de la période 1988-2007 à l’échelle communale a été considérée. Une augmentation significative de l’incidence des leucémies aiguës lymphoblastiques à précurseurs B (LAL-Pré B) chez les moins de 5 ans a été observée avec l’exposition aux UV résidentiels au moment du diagnostic. L’association n’était pas modifiée après une stratification par périodes ; par tranches d’unités urbaines ; par grandes régions, et par un indice de défaveur français. Une deuxième étude, individuelle, sur les UV ne trouvait pas de modification de l’association en prenant en compte le rôle de facteurs individuels soupçonnés d’être associés aux LAL et en regardant l’exposition à la naissance. Les données individuelles de ces facteurs provenaient de deux études cas-témoins en population générale, l’enquête ESCALE (2003-2004) et l’enquête ESTELLE (2010-2011).La dernière partie de la thèse se penche sur l’exposition résidentielle aux pesticides liés aux activités agricoles. Cette étude s’appuie sur les données du RNHE, recueillant 10 994 cas de LA et 4 301 cas de lymphomes sur la période 1990-2013. L’intensité de l’activité agricole dans le canton de résidence au moment du diagnostic a été choisie comme proxy de l’exposition aux pesticides. Cette intensité a été à partir des données cantonales du Recensement général Agricole de 2000. Dans cette première approche aucune association n’a été mise en évidence entre les HME et la part de Surface Agricole Utile (SAU) totale. Les analyses par grands types de cultures montrent, dans cette première approche, une association positive et significative entre l’intensité de cultures en oléagineux et l’incidence des LAL Pré-B et des lymphomes de Burkitt. Des analyses de sensibilité montraient des résultats hétérogènes par période d’étude. / Abstract: This thesis deals with the role of two environmental exposures not much studied and that could have an impact on the incidence of childhood hematological malignancies (CHM): ultraviolet radiation (UV) and agricultural pesticides.The two major diagnostic groups are acute leukemia (AL) and lymphomas and represent respectively around 470 and 200 new cases per year in France. Despite the progress made in improving therapeutic caring and survival, the etiology of these cancers remains largely unknown.There are very few studies on the association between UV and these cancers. Meta-analyses found a coherent association between childhood AL and parental professional or domestic pesticides exposure during pregnancy. However the association with residential exposure to agricultural pesticides has been less studied and results are heterogeneous.The first, ecological, part of the thesis addressed the associations between residential UV exposure at diagnosis and the incidence of types and subtypes of CHM in France. The 9,082 cases of acute leukemia (AL) and 3,563 cases of lymphoma diagnosed before the age of 15 years from 1990 to 2009 were provided by the French National Registry of Childhood Hematological Malignancies. UV data from 1988 to 2007 were extracted from the EUROSUN database. The annual daily average UV exposure of the children estimated at the municipalities of residence was considered. There was a significant increase in precursor B-cell acute lymphoblastic leukemia (PBC-ALL) in children aged less than 5 years with residential exposure to UV. The results remained stable in analyses stratifying by deprivation index or degree of urbanization of the municipalities.A second, individual, study found no change in the association between UV and PBC-ALL after taking into account the influence of suspected individual risk factors for ALL, and evaluated this association at birth. Individual data were collected by interviews in the ESCALE (2003-2004) and ESTELLE (2010-2011) nationwide case-control studies.The last part of this work focused on the residential exposure to agricultural pesticides. The 10,994 cases of AL and the 4,301 cases of lymphomas diagnosed among children less than 15 years old were obtained from the French National Registry of Childhood Hematological Malignancies over the period 1990-2013. Intensity of agricultural activities by Canton was used as a proxy of residential agricultural pesticides exposure. This proxy was estimated from the 2000 French agricultural census data. At this first step of the analysis, no associations were found between total agricultural area and incidence of CHM. Analyses by types of crops showed, at this first step, a significant association between oilseeds and PBC-ALL and Burkitt lymphoma. Sensitivity analyses evidenced heterogeneous results by time period.