Dissertations / Theses on the topic 'Ultra violet (UV)'

Exposure to UV radiation is known to result in the development of skin cancer and the use of protectants m the form of topically applied sunscreens is becoming widespread. The compounds used within sunscreen formulations are subject to stringent tests and must be approved for use by such bodies as COLIPA (EC), or the FDA (U.S.). Despite these testing procedures the photochemical and photophysical properties of many of the active ingredients are poorly understood and not well documented. This study presents the results of detailed photophysical investigations of two sunscreen agents. Menthyl anthranilate is currently approved for use m commercially available formulations by the FDA, and N-acetyl-menthyl anthranilate has been synthesised as an analogue of N-acetyl-homomenthyl anthranilate, a compound approved for use by COLIPA until 1989. This work has highlighted some disturbing properties of these compounds. Following absorption of light both compounds fluoresce m UV-A region. Population of the triplet state also occurs to a significant extent, producing long lived species which are readily quenched by oxygen generating singlet oxygen, a potentially damaging species that has been linked to DNA damage. Furthermore, the triplet state energy of N-acetyl-menthyl anthranilate has been shown to be -315 kJmol(^-1)"', high enough to sensitise the formation of thymine dimers m the skin, another potential source of DNA damage. A thorough understanding of the behaviour of sunscreen formulations m contact with skin is vital. In vivo studies are made difficult due to restrictions in the sampling methods for currently used spectroscopic techniques such as UV and fluorescence. This work demonstrates the use of infixed spectroscopy, utilising an ATR probe and a flat ATR crystal, to analyse sunscreen formulations present on skin at normal usage levels. The technique has been used successfully to identify the individual active components within the formulations, probe the water-resistance properties and monitor changes that occur within the formulations following irradiation. A relationship between the IR absorbance values and Sun Protection Factor (SPF) values of any given formulation has been demonstrated and this has been used to test the water resistance claims of the manufacturers.

Typical CCD image sensors are not sensitive to Ultra-Violet (UV) radiation, because the UV photons have a penetration depth of 2nm in the ~1µm thick polysilicon gate material. An inorganic phosphor coating was developed previously (by Wendy Franks et al [1, 2]) that was shown to be a viable solution to creating a UV-sensitive CCD image sensor. The coating absorbs incident UV radiation (250nm) and re-emits it in the visible (550-611nm) where it can penetrate the gate material. This coating was deposited using a settle-coat type deposition. Improved coating techniques are presented here. These include a commercial coating from Applied Scintillation Technologies (AST), a Doctor-Blade coating, e-beam deposition, and laser ablation. The properties of the coating, and of the coated sensors are presented here. Tests performed on the sensors include Quantum Efficiency, Photo-Response Non-Uniformity, Contrast Transfer Function, and Lifetime. The AST coating is a viable method for commercial UV-responsive CCD image sensors. The Doctor-Blade coatings show promise, but issues with clustering of the coating need to be resolved before the sensors can be used commercially. E-beam deposition and laser ablation need further research to provide a viable coating.

Surface interactions and reactivity are of critical importance in current biomedical technologies, for example, satisfactory cell attachment and long term viability are essential for optimal in vitro tissue culture and for successful implantation and stability of cardiovascular medical implants such as stents and grafts. To achieve this, the control of fundamental forces and the resulting molecular interactions between the relevant surface and absorbing or adhering species in the physiological system is compulsory. This work utilised the surface modification technique of Ultra-Violet/ Ozone to improve the polystyrene biocompatibility by oxidising the surface with additional polar oxygen functional groups without damaging the surface bulk property. UV/Ozone treatment utilised throughout this study produced controllable oxygen functional groups and led to an increase in surface atomic oxygen level to 41% on unwashed and 35% on washed polystyrene surfaces, washing resulted in the removal of low molecular weight oxidised materials. Surface energy was increased by the addition of oxygen functional groups with the combination of alcohol (C-OR), carbonyl (C=O) and carboxyl (O-C=O); Saturation state was reached after 300s of UV/Ozone treatment where no more oxygen functionalities were incorporated to the surface. Moreover, UV/ozone treatment did not show an effect on the surface roughness studied by atomic force microscopy. The biological responses of human endothelial umbilical vein cells (HUVECs) were studied at the different level of UV/Ozone treated surfaces. HUVEC adhesion, proliferation and migration were significantly improved by the treatment compared to untreated and tissue cultures plastics (TCPs). Among the levels of UV/ozone treatment studied, 120s and 180s were found to be the most effective and HUVEC proliferation did not seem to be affected by the high level of oxygen. Similarly, the surface oxygen level did not affect the migration over UV/Ozone treated over 60s. Hypoxic condition significantly increased HUVECs migration on UV/Ozone treated, TCPs and untreated surfaces compared to normoxia, the oxygen rich surface did not favour to HUVECs that underwent regulatory process to enable the cells to increase migration. Under laminar flow conditions, HUVECs did not only grow, proliferate and migrate but also showed standard responses on UV/Ozone treated polystyrene surface. A decrease in cell size was observed at all shear stress intensities studied (1 dyn/cm2, 9 dyn/cm2 and 25 dyn/cm2) and the decrease was more obvious at higher shear stress. High shear stress intensity also induced high cell turnovers, which may be related to air bubbles induced at high flow rate. The overall findings of this study clearly illustrate that UV/Ozone surface treatment can be applied on polystyrene to improve human endothelial cells functionalities in term of adhesion, proliferation and migration in both static and laminar flow environment.

The research from this project has quantified the solar UV environment beneath and surrounding typical local council public shade structures. The effects of changing seasons, atmospheric conditions, structural modifications and surrounding plant life on diffuse UV have been quantified. Strategies to improve current shade structures, so as to significantly reduce the levels of diffuse UV reaching the human body in the shade, have also been developed. For the shade structures used in this research it was found that ultraviolet protection factors ranged from 1.5 to 18.3 for a decreasing solar zenith angle. Correlations have been found relating diffuse erythemal UV to UV in the shade for clear skies and a changing solar zenith angle. The effect of changing atmospheric ozone levels on diffuse erythemal UV levels has been quantified. UV exposures were assessed for a decrease in scattered UV beneath specific shade structures by the use of two types of protection, namely, side-on polycarbonate sheeting and evergreen vegetation. Broadband radiometric and dosimetric measurements conducted in the shade of a scale model shade structure, during summer and winter, showed significant decreases in exposure of up to 65% for summer and 57% for winter when comparing the use and non-use of polycarbonate sheeting. Measurements conducted in the shade of four shade structures, with various amounts of vegetation blocking different sides, showed that adequate amounts and positioning of vegetation decreased the scattered UV in the shade by up to 89% when compared to the shade structure that had no surrounding vegetation. This research shows that major UV reduction could be achieved by the ‘shade creation and design industry’, and that shade guidelines should be updated as soon as possible.

Le SiC est un matériau semi-conducteur à large bande d'énergie interdite dont les très bonnes caractéristiques électriques et thermiques en font un candidat idéal pour la fabrication de composants dans le domaine de la puissance et des détecteurs de rayonnement. En particulier, la réalisation de détecteurs UV est très attendue dans les domaines suivants : détection d'incendies, imagerie de surface, astronomie, médecine, militaire… Les photodétecteurs à base de semiconducteurs à large bande interdite permettent d'obtenir une très bonne sélectivité dans l'UV, sans avoir à utiliser de filtres optiques. Le SiC semble être le matériau le plus prometteur, grâce à sa bonne stabilité chimique, mécanique et thermique, ce qui représente un avantage pour opérer en environnement extrême. Cependant le dopage du SiC nécessite un savoir-faire très particulier (implantation à chaud, recuit à haute température, forte dynamique de chauffe…). Nous nous sommes proposés dans un premier temps de réaliser par implantation (ionique et plasma) des composants tests, permettant d'accéder aux caractéristiques des jonctions. Le cas des jonctions implantées n+p et p+n a été étudié. Après l'optimisation des paramètres technologiques de l'implantation et du recuit associé, la fabrication de détecteurs de rayonnement basés sur la diode Schottky ou la diode p.n a été mise en œuvre. Une étape de simulation de ces composants a été effectuée sur le logiciel Sentaurus Device (Synopsys). Les caractérisations de ces détecteurs ont montré une meilleure sensibilité pour les diodes implantées Bore par plasma
Silicon carbide is a wide band-gap semiconductor with electrical and thermal characteristics particularly suitable for high power devices and radiation sensors. The realisation of UV detectors is mainly useful in the following sectors: fire detection, surface imagery, astronomy, medicine, military... The photodetectors based on wide band-gap semiconductors allow to get a very good selectivity, without using optical filters. Silicon carbide seems to be the most promising material, due to its chemical, mechanical and thermal stability, inducing a reliable behaviour in extreme environment. However SiC doping requires a distinct know-how (hot ion implantation, high temperature annealing, rapid heating-rate…). Test devices have been firstly processed by using ion implantation and plasma, allowing evaluating p+n or n+p junction characteristics. After the optimisation of the technological parameters of implantation and related annealing, the realisation of radiation detectors based on Schottky or p.n diodes has been carried out. The electrical simulations of such devices were performed with Sentaurus Devices program (Synopsys). The characteristics of the devices proved an improvement with the Boron-plasma implantation

Depuis leurs découvertes dans les années 60 par Dewar, les composés BN-hétérocycliques ont subi un développement croissant, s’accentuant pendant la dernière décennie. Ce travail de thèse mené en collaboration avec le Pr S-Y LIU de Boston Collège (États-Unis) et le Pr L. WEBER de l’Université de Bielefeld (Allemagne), a permis la synthèse, ainsi que la caractérisation par spectroscopie photoélectronique à rayonnement UV de nouveaux systèmes. Dans une première partie représentée par les chapitres II, III et IV, nous abordons l’étude de la structure électronique des composés suivants : 1,2-dihydro-1,2-azaborine (1), N-Me-1,2-BN-toluene (2), N-Me-1,3-BN-toluene (3), 1,2-dihydro-1-aza-2-boranaphtalene (4), 1,2-dihydro-1-aza-2-boranthracene (5), 1,2-dihydro-1-aza-2-boranthracene (6), 1,2-dihydro-1-aza-2-boraphenanthrene (7), 1,3,2-benzodiazaborole (8), 1,9,8-benzodiazaborole (9), N-tert-butyl[1,3,2]diazaborolo[1,5-a]-pyridine (10), 1,3,2-trihydro[1,3,2]diazaborolo[1,5-a]-pyridine (11). Afin de compléter les propriétés physico-chimiques de ces nouveaux systèmes et d’aider à l’interprétation des spectres photoélectroniques, l’utilisation de calculs quantiques tels que la théorie de la fonctionnelle de la densité (DFT), la théorie fonctionnelle de la densité en fonction du temps (TD-DFT), la fonction de Green (OVGF), la méthode du troisième ordre partiel (P3), ou encore l’interaction de configuration (SAC-CI) ont été utilisées. Dans le Chapitre V, nous présentons une étude comparative entre les énergies ionisations théoriques et expérimentales
Since the Dewar’s discovering in 60 years, the BN-heterocycles has experienced an important development during the last decade. This thesis presents our work on the synthesis and on the electronic structure characterization by Ultra-Violet photoelectron spectroscopy (UV-PES), followed in collaboration with the Pr SY LIU from the Boston College (USA) and the Pr L. WEBER from the University of Bielefeld (Germany). The first part corresponding to the chapter II, III and IV, describe the electronic structure analysis of: 1,2-dihydro-1,2-azaborine (1), N-Me-1,2-BN-toluene (2), N-Me-1,3-BN-toluene (3), 1,2-dihydro-1-aza-2-boranaphtalene (4), 1,2-dihydro-1-aza-2-boranthracene (5), 1,2-dihydro-1-aza-2-boranthracene (6), 1,2-dihydro-1-aza-2-boraphenanthrene (7), 1,3,2-benzodiazaborole (8), 1,9,8-benzodiazaborole (9), N-tert-butyl[1,3,2]diazaborolo[1,5-a]-pyridine (10), 1,3,2-trihydro[1,3,2]diazaborolo[1,5-a]-pyridine (11). In order to provide more information on the physical chemistry properties and to interpret the photoelectron spectra, the quantum chemical calculations of ionization energies have been followed using the Density Functional Theory (DFT), the Time-Dependent Density Functional Theory (TD-DFT), the Outer Valence Green’s Function (OVGF), the Partial third order (P3), the Symmetry Adapted Cluster-Configuration Interaction (SAC-CI). Moreover, the comparative analysis of theoretical and the experimental ionization energies are presented

Etude par spectrometrie auger de la structure de la surface de si(111) faiblement recouverte d'oxygene sec. L'irradiation par un faible flux de photons uv induit d'importants rearrangements atomiques dans la phase adsorbees avec formation d'une monocouche tres desordonnee de sio::(2) se transformant en sio::(2) amorphe stable apres un recuit thermique a 949 k. L'irradiation de ces couches par un rayonnement laser uv les rend instables. Formation d'une forte densite de defauts structuraux. Etablissement d'une correlation entre les phenomenes physiques evoques

El proyecto empresarial nace de la necesidad de las personas por protegerse de la radiación ultravioleta. A falta de alternativas accesibles y diferentes a las tradicionales para la protección de la piel, UV PROTECT ofrece prendas con protección UV, hechos con tela de 100% algodón con la más alta protección solar UPF 50+ para niños de 2 a 16 años de edad, población que se encuentran mucho menos atendida ante esta problemática que enfrenta nuestro país. La propuesta de UV PROTECT consiste en vender prevención a través de la fabricación de productos innovadores que otorguen protección solar, manejando dos líneas principales de producto. La primera, enfocada en atender necesidades individuales de los padres de protección diaria para sus hijos, ofreciendo prendas con diseños clásicos y modernos que puedan vestir dentro y fuera del hogar. La segunda, está enfocada en atender las necesidades de protección durante el horario de educación escolar, ofreciendo polos de uniforme para colegios privados.
The business project comes up from the need of people to protect themselves from ultraviolet radiation. In the absence of accessible and different alternatives for the protection of the skin, UV PROTECT offers garments with UV protection, made with 100% cotton fabric with UPF 50+ sun protection for children from 2 to 16 years old, a population that is less attended to this problem that faces our country. The UV PROTECT proposal consists of selling prevention through the manufacture of innovative products that provide solar protection, managing two main lines of products. The first, focused on individual needs of parents for daily protection for their children, offering clothes with classic and modern designs that can be used inside and outside home. The second, focused on the needs of protection during school hours, offering polo shirts for private schools.
Trabajo de investigación

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Biomedical Technology in the Faculty Health and Wellness Sciences at the Cape Peninsula University of Technology, 2013
The accurate and consistent measurement of antioxidants is crucial to evaluating their biological role in the prevention and delay of cancer and other pathological conditions. Hence, the performance of the analytical method utilized should be evaluated for acceptable levels of accuracy, precision and other performance parameters according to internationally accepted standards. Additionally, the measure and influence of existing errors should be evaluated and the method optimized to reduce such errors. In furtherance of this vital aim, this research project sought out to optimize and validate two bio-analytical assays for the measurement of total antioxidant capacity and L-ascorbic acid (L-AA), respectively in food commodities. The validation procedure was performed in accordance with ISO 17025 international standard. The first study in this thesis evaluated, optimized and validated the hydrophilic oxygen radical absorbance capacity (H-ORACFL) assay using fluorescein for total antioxidant capacity in various food and beverage products. The assay demonstrated good results with regard to accuracy, precision, linearity, specificity, limits of detection (LOD) and quantification (LOQ) and robustness. The extraction solvent (60% ethanol) recovered excellent antioxidant yields for most samples tested. The optimization of the method in terms of temperature and sample usage on the micro-plate significantly (p<0.05) reduced errors and subsequently improved precision substantially.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A preocupação com a radiação ultra-violeta (UV) do espectro eletromagnético que atinge a superfície terrestre, devido ao aumento do índice de câncer de pele, tem incentivado a pesquisa de produtos para a proteção da pele. Este trabalho tem como objetivo a obtenção e estudo do filtro inorgânico ZnO:Ti4+ com 1, 5, 10, 20, 40, 50% em mol do dopante e a associação dos filtros dopados obtidos com o filtro orgânico 1-(4-terc-butilfenil)-3-(4- metoxifenil)propano-1,3-diona ou butil metoxi dibenzoil metano (bmdm), comercialmente denominado Eusolex 9020. Os filtros dopados foram obtidos pelo método sol-gel, com razão de hidrólise de 0,1 e de 0,01. As amostras foram caracterizadas por espectroscopia de absorção através de medidas de refletância difusa (RD), espectroscopia na região do infravermelho (IV), espectroscopia na região do ultravioleta – visível (UV-Vís), difratometria de raios X (DRX), colorimetria, medidas de potencial zeta, razão UVA/UVB e comprimento de onda crítico foram calculados para conhecer o desempenho dos filtros na região do UVA. Os resultados de DRX indicam a formação da fase ZnO wurtzita para dopagens de até 10%. Acima dessa porcentagem de “dopante”, observa-se a formação de fases de titanatos de zinco (Zn2TiO4 e ZnTiO3). Os espectros no IV apresentam bandas referentes à ligação metaloxigênio deslocadas para maiores números de onda com o aumento da quantidade de dopante, devido ao efeito da força de ligação e do tamanho do íon de titânio em relação ao de zinco nas interações metal-oxigênio. Os espectros de RD apresentam deslocamento das bandas para a região do visível. Os filtros dopados obtidos foram, então, associados com o filtro orgânico bmdm. Os filtros associados foram caracterizados pelas mesmas técnicas acima descritas. Nos espectros IV dos filtros...
The concern with UV radiation of the electromagnetic spectrum that reaches the earth's surface has encouraged the research of products for skin protection due to increased rates of skin cancer. This study aims to obtain and study the inorganic filter ZnO:Ti4+ with 1, 5, 10, 20, 40, 50 at% of doping and the association with doped filters developed through organic filter 1 - (4-tert- butyl phenyl) -3 - (4-methoxyphenyl) propane-1 ,3-dione or butyl methoxy dibenzoyl methane (bmdm), trade name Eusolex 9020®. Doped filters were obtained by the sol-gel method, with hydrolysis ratio of 0.1 and 0.01. The samples were characterized by absorption spectroscopy using diffuse reflectance (DR), infrared (IR) spectroscopy, ultraviolet - visible (UV-Vis), X-ray diffraction (XRD), colorimetric and zeta potential measurements. UVA/UVB ratio and critical wavelength were calculated to know the filter’s performance in the UVA region. XRD results indicate the ZnO wurtzite phase formation step for doping levels up to 10%. Above this percentage of doping, phases of zinc titanates (Zn2TiO4 and ZnTiO3) we observed. The IR spectra show bands of the metal-oxygen shifted to higher wave numbers and an increasing amount of dopant due to the bond strength and size effects of the titanium ion compared to zinc ion in metaloxygen interactions. The RD spectra show shifts of bands for the visible region. Doped filters were then associated with the bmdm organic filter. The associated filters were characterized by the same techniques just described above. In the IR spectra of the associated filters, there is also the band on the metal-oxygen, splitting and shifting of the band related to the carbonyl group when compared with the free bmdm, that indicates an association between the filters. The absorption bands of doped filters do not cover... (Complete abstract click electronic access below)

The presence of the composition trans-resveratrol (4,3',5'-trihidroxiestilbeno) was determined in grape jellies, with and without sugar, industrially produced in Brazil. Beyond this composition, also it has ben determined total phenols, total anthocyanins, total acidity, reducing sugars, soluble solids and color. Although in small concentrations, the presence of trans-resveratrol was positive in all the analyzed commercial jellies. At as a moment, an experiment with the objective was conducted to verify the increase in the concentration of trans-resveratrol in grape jellies, through treatment after-harvest of the grapes of cv. Isabel through irradiation with UV-C ultraviolet light and cooled atmosphere 0,5°C and posterior storage 20oC. The treatment of the grapes in such a way has made possible a significant increase in the concentration of trans-resveratrol in the berries as well as in the radiated clusters. From these radiated grapes, laboratorial production of jellies of grapes with and without sugar was made and submitted to the same analyses of the commercial jellies. These jellies had presented a considerable increase in the levels of trans-resveratrol, when compared with the commercial jellies. The jellies without sugar, due to its process of manufacture, had presented significant higher of this composition. In the sensorial analyses, the consumers did not identify the jellies of radiated grapes, have shown good acceptability, giving preference for its color, aroma and consistency. The results found for sensorial analyses are confirmed by physical-chemical analyses.
A presença do composto trans-resveratrol (4,3 ,5 -trihidroxiestilbeno) foi determinada em geléias de uva com açúcar e sem açúcar produzidas industrialmente no país. Além deste composto, também se determinaram polifenóis totais, antocianinas totais, acidez total, açúcares redutores, sólidos solúveis e cor. Embora em pequenas concentrações, o trans-resveratrol estava presente em todas as geléias comerciais analisadas. Num segundo momento, conduziu-se um experimento com o objetivo de verificar o aumento na concentração de trans-resveratrol em geléias de uva, através de tratamento pós-colheita das uvas da cv. Isabel através de irradiação com luz ultravioleta do tipo UV-C e atmosfera refrigerada a 0,5°C e posterior armazenamento a 20oC. O tratamento das uvas possibilitou um aumento significativo na concentração de trans-resveratrol tanto nas bagas quanto nos cachos irradiados. A partir destas uvas irradiadas, procedeu-se a produção laboratorial de geléias de uvas com açúcar e sem açúcar, que foram submetidas às mesmas análises das geléias comerciais. Estas geléias apresentaram um aumento considerável nos níveis de trans-resveratrol, quando comparadas com as geléias comerciais, sendo que as geléias sem açúcar, devido ao seu processo de fabricação, apresentaram os valores mais expressivos deste composto. Nas análises sensoriais realizadas, os consumidores, mesmo não tendo identificado as geléias de uvas irradiadas, mostraram boa aceitabilidade, dando preferência por sua cor, aroma e consistência. Os resultados da Análise Sensorial são confirmados pelos resultados das análises físico-químicas.

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Universidade Estadual Paulista (UNESP)
Os raios ultravioletas podem desencadear queimadura solar, fotoenvelhecimento e câncer de pele e, por este motivo, foram desenvolvidos os filtros solares. Atualmente considera-se que uma formulação fotoprotetora ideal e de maior fotoestabilidade deve conter em sua formulação associação de filtros solares com ampla capacidade de absorção da radiação UVB e UVA. Dentre os filtros solares utilizados neste trabalho estão o p-metoxicinamato de octila (OMC), um dos mais utilizados globalmente na proteção frente à radiação UVB, a Benzofenona-3, absorvedor de radiação UVB e UVA II, o Ácido Sulfônico Fenilbenzimidazol, um filtro solar UV-B hidrossolúvel e o Bemotrizinol, com amplo espectro. O sítio de ação desejável de um filtro solar é restrito à superfície da pele e sua função é perdida quando este permeia a pele e atinge a circulação sistêmica. Estudos in vivo e in vitro têm demonstrado a permeação e absorção sistêmica de filtros solares através da pele. Este trabalho teve como objetivo avaliar a interferência da associação dos filtros solares benzofenona 3, ácido sulfônico fenilbenzimzidazol e BEMT nos estudos de estabilidade, liberação, permeação e retenção cutânea in vitro do OMC. A metodologia de identificação e quantificação do OMC foi validada, levando-se em consideração a análise dos limites de confiança. Foram realizados estudos de estabilidade preliminar e acelerada das formulações e do OMC em virtude da fotoinstabilidade do mesmo. Os estudos de liberação, permeação e retenção cutânea foram realizados utilizando-se o equipamento de célula de difusão vertical de Franz modificada e as membranas utilizadas foram acetato de celulose para o estudo de liberação e orelha de porco para permeação e retenção cutânea. Os resultados obtidos permitiram concluir que as formulações estudadas apresentaram comportamento...
Ultraviolet rays can cause sunburn, photoaging and skin cancer and, because of this, sunscreens were developed. Currently it is considered that an ideal sunscreen formulation and greater photostability must contain in its formulation association of solar filters with high capacity to absorb UVB and UVA. Among the solar filters used in this work are p-octyl methoxycinnamate (OMC), one of the most globally used in the protection against UVB radiation, Benzophenone-3, UVB and UVA II absorber Fenilbenzimidazol Sulfonic Acid, a UV-B hidrosoluble solar filter and Bemotrizinol with broad spectrum. The desirable site of action of a solar filter is limited to the skin surface and its function is lost when it permeates the skin and reaches the systemic circulation. In vivo and in vitro studies have demonstrated the permeation and systemic absorption of solar filters across the skin. This study objective was to evaluate the interference of association of the solar filters benzophenone-3, fenilbenzimzidazol sulfonic acid and BEMT on the stability, release, in vitro skin permeation and retention of the OMC. The methodology for OMC’s identification and quantification was validated, taking into account the confidence limits analysis. Preliminary and accelerated stability studies of the formulations and the OMC, because of it’s photoinstability. The release studies, skin permeation and retention were performed using the equipment Franz’s vertical diffusion cell modified, and the membranes used were cellulose acetate for the release study and pig ear skin for permeation and retention. The results showed that the formulations studied showed similar behavior stability and OMC’s release, regardless of the association of the solar filters... (Complete abstract click electronic access below)

Resumo: Os raios ultravioletas podem desencadear queimadura solar, fotoenvelhecimento e câncer de pele e, por este motivo, foram desenvolvidos os filtros solares. Atualmente considera-se que uma formulação fotoprotetora ideal e de maior fotoestabilidade deve conter em sua formulação associação de filtros solares com ampla capacidade de absorção da radiação UVB e UVA. Dentre os filtros solares utilizados neste trabalho estão o p-metoxicinamato de octila (OMC), um dos mais utilizados globalmente na proteção frente à radiação UVB, a Benzofenona-3, absorvedor de radiação UVB e UVA II, o Ácido Sulfônico Fenilbenzimidazol, um filtro solar UV-B hidrossolúvel e o Bemotrizinol, com amplo espectro. O sítio de ação desejável de um filtro solar é restrito à superfície da pele e sua função é perdida quando este permeia a pele e atinge a circulação sistêmica. Estudos in vivo e in vitro têm demonstrado a permeação e absorção sistêmica de filtros solares através da pele. Este trabalho teve como objetivo avaliar a interferência da associação dos filtros solares benzofenona 3, ácido sulfônico fenilbenzimzidazol e BEMT nos estudos de estabilidade, liberação, permeação e retenção cutânea in vitro do OMC. A metodologia de identificação e quantificação do OMC foi validada, levando-se em consideração a análise dos limites de confiança. Foram realizados estudos de estabilidade preliminar e acelerada das formulações e do OMC em virtude da fotoinstabilidade do mesmo. Os estudos de liberação, permeação e retenção cutânea foram realizados utilizando-se o equipamento de célula de difusão vertical de Franz modificada e as membranas utilizadas foram acetato de celulose para o estudo de liberação e orelha de porco para permeação e retenção cutânea. Os resultados obtidos permitiram concluir que as formulações estudadas apresentaram comportamento... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Ultraviolet rays can cause sunburn, photoaging and skin cancer and, because of this, sunscreens were developed. Currently it is considered that an ideal sunscreen formulation and greater photostability must contain in its formulation association of solar filters with high capacity to absorb UVB and UVA. Among the solar filters used in this work are p-octyl methoxycinnamate (OMC), one of the most globally used in the protection against UVB radiation, Benzophenone-3, UVB and UVA II absorber Fenilbenzimidazol Sulfonic Acid, a UV-B hidrosoluble solar filter and Bemotrizinol with broad spectrum. The desirable site of action of a solar filter is limited to the skin surface and its function is lost when it permeates the skin and reaches the systemic circulation. In vivo and in vitro studies have demonstrated the permeation and systemic absorption of solar filters across the skin. This study objective was to evaluate the interference of association of the solar filters benzophenone-3, fenilbenzimzidazol sulfonic acid and BEMT on the stability, release, in vitro skin permeation and retention of the OMC. The methodology for OMC's identification and quantification was validated, taking into account the confidence limits analysis. Preliminary and accelerated stability studies of the formulations and the OMC, because of it's photoinstability. The release studies, skin permeation and retention were performed using the equipment Franz's vertical diffusion cell modified, and the membranes used were cellulose acetate for the release study and pig ear skin for permeation and retention. The results showed that the formulations studied showed similar behavior stability and OMC's release, regardless of the association of the solar filters... (Complete abstract click electronic access below)
Orientador: Rosângela Gonçalves Peccinini
Coorientador: Marcos Antonio Corrêa
Banca: Marlus Chorilli
Banca: Patrícia Maria Berardo Gonçalves Maia Campos
Mestre

碩士
國立交通大學
機械工程系所
95
Dielectric barrier discharge (DBD) has developed for a long time, and has widely application in many fields. Among them, the excimer lamp attracts goodliness attention in recent years due to its widely application in industry, for example, new materials processing, photochemistry, fluorescent lamp and plasma display panels. In order to deal with more and more application, to promote light intensity of 172 nm becomes a questing goal. In this experiment, we discuss the effect of mixture fraction on light intensity by means of put in pure Xe and rare gas mixture. And to adjust gas total pressure, frequency and input power to observe the change of light intensity. Finally, we can realize the relation between the factors and the light intensity, and obtain the optimized operating conditions.

碩士
國立成功大學
機械工程學系
105
This thesis studies the design and optical performance of collimating lenses for modulating the UV lights from an ultraviolet light emitting diode (UV LED). The lens design is based on freeform surfaces and total internal reflection (TIR) surfaces for collimating the UV light which might have a relatively large diverging angle when emitting from the LED. The advantages of this kind of lens design are higher optical efficiency, lower fabrication cost, and compact lens size. A systematic approach for the lens design is developed based on geometrical optics by assuming a point source for the LED. However, since LEDs are finite area light sources in reality, the optical performance and characteristics of the obtained lens profile along with its corresponding UV LED are simulated and analyzed by a commercial ray tracing software (Zemax). The designed lens/LED units are used for two different applications: (1) to illuminate a fly’s eyes homogenizer system and therefore project the UV light into an area with uniform intensity distribution; and (2) to collectively form an array of UV light sources for UV exposure. For the first purpose and when working with a high power (13.4 Watt) UV-LED with a 3×3 mm2 emitting area size and a divergent angle of 120°, a freeform/TIR collimating lens can achieve a high optical efficiency of 67.6 % and a collimation angle of ±4.5°. For the second applications, a conventional double convex lens with both aspheric surfaces is designed for two kinds of UV-LEDs of 60o and 120o divergent angles, and the optical efficiency is 42.62 % and 30.70 %, respectively, with and collimation angle of ±3.94° and ±2.55°, respectively. Finally, to further improve the optical performance, a freeform/TIR collimating lens is designed for a low power UV-LED with a 1.25×1.25 mm2 emitting area size and a divergent angle of 120°. The optical efficiency is 45.8 % with the collimation angle of ±2°. Experimental measurements have been carried out on the conventional double convex lens along with two UV LEDs, and the measured data are analyzed and compared with their theoretical counterparts.

碩士
南台科技大學
光電工程系
98
There had been few published literatures of porous-silicon (PS) on ultra-violet (UV) photodetectors, because the optical absorption of this material ranged from visible to infrared light. Although as a wide-bandgap semiconductor due to the quantum-size effect, nano-porous-Si (NPS) also can hardly absorb UV energy due to its insufficiently large bandgap (< 2ev). In this thesis, oxidized nano-porous-Si (ONPS) that prepared by rapid-thermally oxidizing NPS thin-films was proposed for UV sensing applications. NPS thin-films with uniformly distributed Si nano-crystallites (3nm~10nm) were firstly prepared on heavily doped p+-type (100) Si wafers by anodic etching processes with low etching current density (10mA/cm2 ). Then ONPS films were obtained from rapid-thermal-oxidation (RTO) treatment of NPS at 850℃ for 90 sec. Photo-sensing diodes were made with ONPS films as the light-absorption layers, after depositing inter-digitated aluminum (Al) electrodes on the front sides of the devices. The optical bandgap of a NPS film was measured about 1.6ev, whereas it was raised to 3.5ev for the as-formed ONPS film after RTO processes. The photo-response spectra of a NPS film located within wavelengths from 500nm to 900nm. However, an ONPS film exhibited high photoresponsivity for incident wavelengths between 300nm and 400nm, showing it was very suitable for UV sensing applications. Furthermore, an ONPS photodiode can achieve a high photo-to-dark current ratio up to about 2000 under an incident light wavelength of 350nm while obtained quite low dark current down to 7.3A/cm2. Experimental results indicated that ONPS photodetectors had high UV sensitivity. Finally, a tentative carrier transport mechanism was proposed to illustrate the UV photoresponse processes in an ONPS structure.