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Dissertations / Theses on the topic 'Solar exposure'
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Laungrungthip, Nuchjira. "Sky detection in images for solar exposure prediction." Diss., Lincoln University, 2008. http://hdl.handle.net/10182/855.
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This project describes a technique for segmenting regions of sky in an image from the remainder of the image. This segmentation technique is part of a method for predicting the solar exposure at a location of interest from a set of photographs. Given the latitude and longitude of the position and the direction and field of view of the camera it is possible to calculate the position of the sun in the image at a particular time on a particular day. If that position is in a sky region of the image then the location will be exposed to the sun at that time. Critical to the success of this method for determining solar exposure is the image processing used to separate the sky from the rest of the image. This work is concerned with finding a technique which can do this for images taken under different weather conditions. The general approach to separate the sky from the rest of the image is to use the Canny edge detector and the morphology closing algorithm to find the regions in the image. The brightness and area of each region are then used to determine which regions are sky. The FloodFill algorithm is applied to identify all pixels in each sky region. An extensive empirical study is used to find a set of threshold values for the Canny edge detector, applied to the blue colour channel, which allow successful identification of the sky regions in a wide range of images. Tests using different camera filters show that they do not usefully increase the contrast between the sky and the rest of the image, when a standard compact camera is used. The work reported in this thesis shows that this approach of finding edges to identify possible sky regions works successfully on a wide range of images although there will always be situations, such as when the image is taken directly into the sun, where manual adjustment to the identified regions may be required.
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Weaver, Bess A. "Solar Ultraviolet Radiation Exposure in Outdoor Work Environment at Bowling Green, Ohio." University of Toledo Health Science Campus / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=mco1211995092.
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Schouten, Peter. "Better characterisation of the underwater solar ultraviolet environment using a high-exposure dosimeter." University of Southern Queensland, Faculty of Sciences, 2009. http://eprints.usq.edu.au/archive/00006248/.
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[Abstract]This dissertation presents the development, testing and application of a chemical film UV dosimeter based on the polymer Poly (2, 6-dimethyl-1, 4-phenylene oxide) (PPO) prepared especially for long – term high – exposure underwater use. Initial testing of the dosimeter was performed in a water tank within a controlled laboratory environment with an artificial UV source in which various optical and physical properties of the film were rigorously tested such as UV dose and depth response, cosine response, interdosimeter variation, dose rate independence, dark reaction, watermarking effect, exposure additivity and visible and UVA wavelength response. In each of these tests the PPO dosimeter displayed results proving that it could be reliably used in aquatic environments at a level of accuracy only slightly lower than what could be expected for in – air dosimetric measurements. The use of a polyethylene derived neutral density filter (NDF) was then employed with the PPO dosimeter in order to extend exposure time. Results from this investigation showed that the polyethylene NDF could extend the effective life time of the PPO dosimeter by as much as five days in early autumn. Following this the PPO dosimeter was calibrated in the field to the solar erythemal action spectrum in – air and to the solar UVB spectrum in clear water, creek water, sea water and dam water over the duration of a year. In both the in – air and underwater calibrations it was found that the response of the PPO dosimeter lasted over a much greater amount of time when compared to the more commonly used polysulphone dosimeter and also varied with the modulation of the incident solar spectrum brought on by changing SZA and fluctuations in atmospheric column ozone. Additionally, it was discovered that in – air and underwater calibration regimes could not be interchanged and that the PPO dosimeter response underwater is dependent upon water type, but only when transmission spectra differed between two water types by a difference on average of more than 5% across the UVB waveband. As a final test, the PPO dosimeter was deployed over a year to take UVB exposure measurements with the use of a custom built submersible float in three different real – world field environments that included a creek, a sea water tank and a stagnant dam. Exposures could be measured reliably up to a depth of 5 cm in the creek water and the dam water and up to and possibly beyond a depth of 35 cm in the sea water. From the sea water PPO dosimeter measurements a series of attenuation coefficients were estimated for each season. These coefficients showed reasonable agreement when compared to attenuation coefficient calculations made using a calibrated spectrometer in the same sea water, further proving the usefulness of the PPO dosimeter.
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Cobb, Jennifer L. "Validation of a Sun-Exposure Questionnaire for Adolescent Girls." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/CobbJL2001.pdf.
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Turnbull, David J. "Development of an improved shade environment for the reduction of personal UV exposure." University of Southern Queensland, Faculty of Sciences, 2005. http://eprints.usq.edu.au/archive/00001519/.
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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.
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Kelbch, Alexander [Verfasser]. "Investigations to quantify individual exposure to solar ultraviolet erythemal radiation including cloud meteorological impact / Alexander Kelbch." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1218301309/34.
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Leitão, José Maurício de Moura. "Estudo de materiais poliméricos para a plicação em coletores solares planos." Universidade do Vale do Rio dos Sinos, 2018. http://www.repositorio.jesuita.org.br/handle/UNISINOS/7650.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Eficiência e economia na produção de energia são fatores-chave no desenvolvimento social e econômico de um país. A energia solar é uma fonte de energia limpa e renovável, utilizada em sua maior parte para o aquecimento de água por meio de coletores solares. Nos últimos 15 anos, os coletores solares planos vêm, devido ao apelo mundial para o uso de materiais mais facilmente recicláveis e ao baixo custo, utilizando cada vez mais materiais poliméricos, substituindo os convencionais. Para analisar quais materiais poliméricos podem ser usados em coletores solares planos, este trabalho realizou um teste de intemperismo acelerado nos materiais polissulfona (PSU), polietileno (PE) e policarbonato (PC). Destacam-se o PSU e o PE. O PSU tem o melhor resultado em relação ao nível de degradação, pois sua cadeia polimérica é composta por anéis aromáticos e fortes ligações de carbono, enxofre e oxigênio dentro da espinha dorsal do polímero. Adicionalmente, foram realizadas análises do infravermelho nos materiais envelhecidos na câmara de intemperismo acelerado pelo método ATR ou refletância total atenuada. Eles apresentaram, na cadeia molecular, pequenas mudanças nos espectros na região do infravermelho à medida que o tempo exposto na câmara de envelhecimento aumentava. Por fim, foi desenvolvida uma simulação numérica de um coletor solar plano na plataforma ESS (Engineering Equation Solver) em que foi simulado o efeito do número de tubos no absorvedor com diferentes materiais e foi simulada uma geometria de tubos de sessão quadrada no absorvedor. A simulação apresentou o melhor resultado com um absorvedor construído com 100 tubos de sessão quadrada de polissulfona, no qual a eficiência teoricamente pode chegar a 81,62%.
Efficiency and economy in energy production are key factors in the social and economic development of a country. Solar energy is a source of clean and renewable energy used for heating water through solar collectors. Over the past 15 years, due to the worldwide appeal for the use of more readily recyclable materials and their low cost, flat solar collectors have increasingly used polymeric materials to replace conventional ones. In order to assess which polymeric materials can be used in flat-plate solar collectors, an accelerated temperature test has been conducted on polysulfone (PSU), polyethylene (PE), and polycarbonate (PC). PSU and EP have stood out. PSU had the best result for degradation because its polymeric chain is composed of aromatic rings and strong bonds of carbon, sulfur and oxygen within the backbone of the polymer. Additionally, infrared analyses have been made of the materials aged in the accelerated temperature chamber according to the ATR method or attenuated total reflectance. They presented small molecular chain changes in the spectra in the infrared region as exposure time in the UV chamber increased. Finally, a numerical simulation of a flat solar collector was developed in the ESS (Engineering Equation Solver) platform in which the effect of the number of tubes in the absorber with different materials was simulated as well a geometry of square session tubes in the absorber. The simulation presented the best result with an absorber built with 100 polysulfone square session tubes, in which efficiency can theoretically reach 81.62%.
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Braun, Gunnar Johannes. "Ermittlung des Wissensstandes über Schutzmaßnahmen gegen solare Exposition in Mitgliedsbetrieben als Grundlage für die präventive Tätigkeit der BG ETEM." Master's thesis, Dresden International University, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235002.
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In dieser Masterthesis wird erforscht wie der jetzige Kenntnisstand der Sicherheitsfachkräfte zu den Themen solare Exposition, Schutzmaßnahmen und die Akzeptanz der Schutzmaßnahmen durch die Mitarbeiter in den Mitgliedsbetrieben der BG ETEM ist. Diese Themen gewinnen an Bedeutung seit die Berufskrankheit Nummer 5103 in den Anhang 1 der Berufskrankheitenverordnung aufgenommen wurde und die BG ETEM nun für ihre Versicherten auch diesbezüglich präventiv tätig ist.
Im Rahmen dieser Masterthesis wurde für die Erforschung des Kenntnisstands ein Fragebogen mit zugehörigem Interviewleitfaden selbst entwickelt. Die anschließenden Befragungen wurden durch den Ersteller in den teilnehmenden Unternehmen persönlich für die Masterthesis vorgenommen. Der Teilnehmerkreis beschränkt sich auf interne Sicherheitsfachkräfte, die in Unternehmen der Branche Energie- und Wasserwirtschaft beschäftigt sind. Erforscht werden neben allgemeinen und betrieblichen Angaben ihr Kenntnisstand zu den Themengebieten Gefährdungsbewusstsein, Gefährdungsbeurteilung, Schutzmaßnahmen und der Informations- und Fortbildungsbedarf. Die Antworten werden mit den eigenen Erwartungen verglichen und Rückschlüsse daraus gezogen. Für die BG ETEM werden die Ergebnisse dieser Masterthesis im Hinblick auf den Präventionsauftrag analysiert. Hierzu werden im Rahmen der Masterthesis auch Vorschläge zu diesen Maßnahmen gemacht. So sollen die Beratungen, Informationsmaterialien und Fortbildungen auf die Präferenzen sowie die vorhandenen Wissenslücken in den Unternehmen zugeschnitten werden, um hier berufsbedingte Neuerkrankungen durch solare Exposition langfristig weitgehend zu verhindern.
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Stojanovic, Bojan. "Lifetime Performance Assessment of Thermal Systems : Studies on Building, Solar and Disctrict Heating Applications." Doctoral thesis, KTH, Byggvetenskap, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10967.
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The main questions today concerning thermal systems are their economical and environmental impacts. These entities are generally, at present, assessed on the basis of operation performances of newly installed/designed systems, during an assumed lifetime period. While this is the common way of perceiving thermal systems, performance-over-time will change as an effect of degradation, and not solely of different operation scenarios. How and to what extent is the question that needs assessing in order to evaluate if these changes will jeopardise the intended system performance requirement, hence service life (SL). The lack of knowledge/approaches and tools for assessing durability and performance-over-time of thermal systems complicates the task of incorporating these aspects in engineering. In turn, this pro-active assessment and analysis is in line with today’s performance based directives, laws and regulations; of which the working life is an essential part. The durability of materials, components and systems is not a topic that is an end in itself, but becomes a vital part in a comprehensive perspective as sustainability. The lifetime performance assessment of thermal systems, as presented in this thesis, shows that it is a vital part of the R&D in the quest of sustainable energy/thermal systems and energy use. This thesis gives knowledge to the thermal (energy) system/technology R&D and engineering sector, regarding durability and lifetime performance assessment methodologies; but also to the durability of construction works sector, regarding the needs for assessing lifetime performance of materials and components in relation to system performance. It also presents descriptions of requirements on construction works. Specifically, the studies presented in the thesis show how durability and lifetime performance assessment of thermal systems may be sought, with knowledge on: methodologies, exposure test set-ups, modelling and the attainment and use of adequate tools. The main focus is on performance-over-time modelling, tying material/component degradation to altered thermal performance, thereby attaining performance-over-time assessment tools to be used in order to incorporate these aspects when engineering thermal systems; hence enabling the forecasting of SL. The presented work was predominantly done in association to the EU project ENDOHOUSING. The project developed a solar-assisted heat pump system solution, with heat storage, to provide the thermal energy to meet space heating, cooling and hot water requirements for domestic houses in different regions of the EU. The project constituted the platform for the work presented in this thesis, thereby outlining the main context with studies on durability and lifetime performance of: flat plate solar collectors ground heat sources/storages and interaction with a heat pump system evaluation of the ENDOHOUSING solar-assisted heat pump system The thesis also presents a study of SL prediction and estimation of district heating distribution networks (an additional thermal system application). In this particular context, the Factor Method is proposed as a methodology. The main issue of lifetime performance of thermal systems is how and to what extent performance reduction in individual materials or components influence the overall system performance, as the essence of energy/thermal system sustainability is system performance.QC 20100810
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Peters, Cheryl Elizabeth. "Solar ultraviolet radiation and outdoor workers in Canada : a program of research on exposure assessment, sun protection behaviours and prostate cancer risk." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/53793.
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Background: Exposure to solar ultraviolet radiation (UVR) is the main cause of skin cancer, and emerging evidence shows that it may prevent prostate cancer. Understanding the etiology of skin cancer has been challenged by a lack of detailed exposure assessment instruments, and this influences the ability to study the effect of solar radiation on other, more multi-factorial diseases.
Methods: In the first study (Chapters 3 and 4), 78 outdoor workers wore UVR dosimetry badges for five work days, and provided information on skin cancer risk factors and sun protective behaviours. This data was used to investigate levels of exposure and prevention behaviours. The second study (Chapters 2 and 5) developed a job exposure matrix (JEM) based on occupation/industry, time spent outdoors and satellite data on available ambient UVR. The JEM was used to investigate the risk of prostate cancer in outdoor workers using a previously conducted population-based case-control study.
Results: Over 300 UVR measurements were taken among seventy-three workers. Exposure was variable; the main predictors of exposure were time spent outdoors and meteorology. Outdoor workers relied more on clothing (hats, shirts) than on shade or sunscreen for protection. Sun protection scores showed that fairer people used more protection. The job sites’ clothing requirements also influenced protective behaviours. Based on the JEM, approximately 1.5 million Canadians (82% male) were exposed to solar UVR at work (for ≥2 hours/day). The largest exposed groups were construction workers, farmers and landscapers. Prostate cancer cases (n=1638) were compared to controls (n=1697) using the UVR satellite data-enhanced JEM and case status from national cancer registries. A statistically significant decrease in risk of prostate cancer was found in the highest exposed workers.
Conclusions: Outdoor workers in Canada experience high levels of solar UVR exposure. Sun protection was relatively high and was driven by workplace requirements, which suggests company policies requiring hats and shirts could be an effective prevention strategy. JEMs are a key tool for population-level studies, and the addition of objective measures into the matrix for solar UV radiation was an innovation that showed high, long-term occupational exposure to solar UVR is protective for prostate cancer.Medicine, Faculty of
Population and Public Health (SPPH), School of
Graduate
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Rangaswamy, Ashok. "Effect of CdCl2 Treatment on CdTe and CdS Solar Cell Characteristics after Exposure to Light for 1000 Hours." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000064.
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Costa, Rita Silvestre. "A percepção de risco no cancro da pele: Um estudo com "banhistas." Master's thesis, ISPA - Instituto Universitário, 2012. http://hdl.handle.net/10400.12/2288.
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Dissertação de Mestrado em Psicologia ClínicaO cancro da pele tem aumentado consideravelmente na população Caucasiana e os números em Portugal são um reflexo desse aumento. A literatura refere que a incidência deste tipo de cancro poderia ser menor se os indivíduos tivessem comportamentos de prevenção. As taxas podem diminuir se os cidadãos evitarem exposições prolongadas ao sol e se utilizarem proteção solar. Pelos poucos estudos encontrados em Portugal, a presente investigação tem como objetivo principal perceber como é que uma amostra de cidadãos portugueses perceciona o risco face ao cancro da pele num contexto balnear. Tem ainda como objetivos específicos compreender se existem diferenças na perceção de risco do cancro da pele face às variáveis sociodemográficas e clínicas. Foi recolhida uma amostra de 318 participantes, que frequentavam a praia, com idades compreendidas entre os 18 e os 74 anos. Utilizaram-se como instrumentos, o Questionário Sócio-Demográfico e a Escala de Perceção de Risco face ao Cancro da Pele. Verificou-se que a amostra teve uma perceção de risco média. Para o género feminino (t=5,638, p=0,000), cor de pele (F=3,214, p= 0,013), queimaduras solares (t= -2,420, p=0,016), frequência do protetor solar (F= 7,270, p= 0,001), observação de alterações provocadas pela doença (t= -2,336, p=0,020), constatou-se um resultado estatisticamente significativo para a perceção de risco e suas dimensões. Encontrou-se evidência para uma correlação positiva entre a perceção e suas dimensões e o autoexame, check-up médico e influência do bronzeado sobre a aparência. Não se obteve resultados significativos para as variáveis idade, escolaridade e contacto com indivíduos com cancro da pele. ------- ABSTRACT ------ Skin cancer has increased considerably in the Caucasian population and the numbers in Portugal reflect this increase. Scientific literature suggests that the incidence of this type of cancer could be prevented if individuals took preventive behaviors. Effectively, rates may decrease if citizens avoid prolonged exposure to the sun and protect themselves when exposed. Taken into account the few studies that were found in Portugal within this subject, this research aims to understand how a sample of Portuguese citizens during bathing season perceive the risk of skin cancer. This research also has the goal to understand whether there are differences in the perception of the risk of skin cancer in demographic and clinical variables. A sample of 318 participants aged between 18 and 74 years old, was collected. Both the Socio-Demographic Questionnaire and the Scale of Perceived Risk of Skin Cancer were used. The sample had an average risk perception. For females (t = 5.638, p = 0.000), skin color (F = 3.214, p = 0.013), sunburn (t = -2.420, p = 0.016), frequent application of sunscreen (F = 7.270, p = 0.001), observation of changes caused by this disease (t = -2.336, p = 0.020) showed a statistically significant result for the perception of risk and its dimensions. Positive correlations were found between perception and its dimensions with self-examination, medical check-up and influence of tan in appearance. No significant results were obtained for the variables age, education and contact with individuals with skin cancer.
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Augustine, B. (Bobins). "Efficiency and stability studies for organic bulk heterojunction solar cells." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526214436.
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Abstract The qualitative and quantitative characteristics of each component layer constituting the structure of organic bulk heterojunction solar cells (OSC-BHJ) contribute significantly towards its overall performance. One of the prevalent issues resulting in reduced device efficiency is due to the conformational inhomogeneities in the active and buffer layers. The mechanical stress, extended thermal exposure and presence of mutually reactive component layers etc., affects negatively on the device stability. Effective methods to address these issues will be extensively benefited by the industry since the current commercialisation of the technology is hindered owing to the lower efficiency and stability of these devices. This dissertation focuses on methods to coherently enhance the performance and longevity of the OSC-BHJ devices. The efficiency enhancements of the devices in this work were achieved through two main routes. The first route was through morphological improvement of the active layer. The second route was through boosting the electrical characteristics of hole transporting conducting polymer layer (HTL) by controlled annealing conditions. The introduction of a suitable additive in the active layer was found to reduce unfavourable phase segregation thus resulting in enhanced morphology. Further, the annealing conditions in different atmospheres (air, nitrogen and vacuum) were found to have a clear influence on the optimum functioning of the HTL in the device. Regarding the stability improvement study done in this work, a method of employing suitable interlayer was developed to effectively abate the internal degradation occurring in the device due to etching reaction on the indium tin oxide (ITO) anode by the HTL. Moreover, experimental investigations were carried out for drawing fundamental understanding of stability degenerating issues such as the influence of mechanical defects on transparent conducting metal oxide (ITO) anode on the performance of the device and heat induced degradations in the low band gap polymer-fullerene active layer. The highlight of this research is that the discovered methods are inexpensive, efficient, and easy to adopt. The results of the study could help the technology to overcome some of its limitations and accelerate its progress towards commercialisationTiivistelmä Orgaanisten heteroliitosaurinkokennojen kerrosrakenteen ominaisuudet ja laatu vaikuttavat merkittävästi aurinkokennojen toiminnallisuuteen. Erityisesti rakenteelliset epähomogeenisuudet aktiivi- ja puskurikerroksissa heikentävät kennon hyötysuhdetta. Kennojen stabiilisuutta tarkasteltaessa myös mekaanisella rasituksella, pitkittyneellä lämpöaltistuksella ja materiaalien reagoinneilla keskenään kerrosten välillä, on selkeä negatiivinen vaikutus kennojen stabiilisuuteen. Orgaanisen aurinkokennoteknologian kaupallistamisen rajoitteina ovat kennojen heikko hyötysuhde ja stabiilisuus, joten menetelmät jotka tarjoavat ratkaisuja edellä mainittuihin ongelmiin, ovat erittäin tärkeitä teknologiaa kaupallistavalle teollisuudelle. Tämä väitöskirja keskittyy johdonmukaisesti selvittämään tapoja, joilla voidaan parantaa heteroliitosaurinkokennojen hyötysuhdetta ja elinikää. Hyötysuhteen tehostamiseksi valittiin kaksi eri lähestymistapaa, joista ensimmäisessä keskityttiin aktiivikerroksen morfologian parantamiseen ja toisessa aukkoja kuljettavan kerroksen sähköisten ominaisuuksien parantamiseen lämpökäsittelyprosessin avulla. Sopivan lisäaineen avulla aktiivikerroksen ei-toivottua kiteytymistä voidaan pienentää ja parantaa näin kerroksen morfologiaa. Lisäksi työssä todettiin, että lämpökäsittelyn aikaisella ympäristöolosuhteella (ilma, typpi, tyhjiö) on merkittävä vaikutus puskurikerroksen optimaaliseen toimintaan aurinkokennossa. Stabiilisuuden parantamiseksi kehitettiin välikerroksen hyödyntämiseen perustuva menetelmä, jolla voidaan tehokkaasti vähentää kennojen sisäisessä rakenteessa tapahtuvaa toiminnallisuuden heikkenemistä, joka aiheutuu aukkoja kuljettavan kerroksen syövyttävästä vaikutuksesta indiumtinaoksidi (ITO) pohjaiseen anodiin. Tämän lisäksi työssä tutkittiin kokeellisesti stabiilisuuteen heikentävästi vaikuttavia tekijöitä, kuten mekaanisen rasituksen aiheuttamia vaurioita metallioksidi (ITO) anodissa ja lämpöaltistuksesta aiheutuvia vikoja polymeeri-fullereeni rakenteeseen perustuvassa aktiivikerroksessa. Tutkimuksen keskeisin tulos on, että esitellyt keinot aurinkokennojen hyötysuhteen ja stabiilisuuden parantamiseen ovat edullisia, tehokkaita ja helppoja hyödyntää. Tulokset voivat merkittävästi edistää orgaanisten aurinkokennojen teknistä kehitystä ja kiihdyttää niiden tuloa kaupallisiksi tuotteiksi
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van, Pelt Thomas. "Thin films of [6,6]-phenyl-C61-butyric acid methyl ester for application in organic solar cells : preparation and effects of exposure to light and heat." Thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-27500.
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Chaillol, Isabelle. "Mesure de l’exposition au rayonnement ultraviolet solaire pour les études épidémiologiques." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10231/document.
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Le rayonnement ultraviolet (UV) est un cancérigène pour lequel peu d’informations sur l’exposition des populations est disponible. L’intensité et les variations de l’exposition au rayonnement UV solaire, principale source d’exposition, a un impact sur la santé mais il est difficile de les surveiller. Le travail de cette thèse a permis de développer un outil pour une estimation quantitative de l’exposition individuelle à l’UV solaire pour l’épidémiologie. Nous avons créé un atlas des moyennes mensuelles d’irradiation journalière en Europe. Certaines données manquantes au niveau des pays nordiques en hiver ont dû être extrapolées. Nous avons vu que la saisonnalité est forte et que la répartition spatiale ne suit pas seulement le gradient de latitude. Par exemple, l’irradiation UV est plus élevée au sud des pays nordiques qu’au centre de l’Europe. Une enquête a été menée dans huit populations européennes afin d’estimer l’exposition individuelle. Ces populations ont des comportements différents vis-à-vis de l’exposition au soleil. Après une étape de modélisation pour estimer les données d’irradiation UV manquantes au nord de la Norvège sur l’ensemble de l’année, nous avons pu quantifier l’exposition chronique et l’exposition pendant les vacances dans trois populations (française, italienne et norvégienne). L’outil développé au cours de cette thèse pourra être utilisé pour de futures études épidémiologiques qui permettront de connaître l’exposition au rayonnement ultraviolet solaire de populations et de mieux comprendre son rôle dans l’étiologie de diverses maladies, telles que les cancers cutanésUltraviolet radiation (UV) is a carcinogenic agent for which little information on human exposure is available. The intensity and the changes of solar UV exposure, which is the main source of exposure, have an impact on health but are difficult to monitor. The work of this thesis led to the creation of a tool for quantitative estimation of individual exposure to solar UV that can be used in epidemiological studies. We created an atlas of monthly average daily radiation across Europe. Some missing values from the Nordic countries during winter had to be extrapolated. We observed a strong seasonality and characteristics in the spatial distribution which does not always follow the gradient of latitude. For instance, UV radiation is higher in the southern area of the Nordic countries than in central Europe. A survey was conducted in eight European populations to estimate individual exposure. These populations have different behaviours regarding sun exposure. After a step of modeling to estimate missing values in northern Norway throughout the year, we quantified chronic and holiday exposure in three populations (France, Italy and Norway). The tool developed during this thesis will be used for future epidemiological studies that will contribute to improving the knowledge about UV exposure in populations and better understanding its role in the aetiology of various diseases, such as skin cancers
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Nottingham, Mark. "Resonance photo-ionisation mass spectrometry techniques for the analysis of heavy noble gas isotopes in extra-terrestrial samples." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/resonance-photoionisation-mass-spectrometry-techniques-for-the-analysis-of-heavy-noble-gas-isotopes-in-extraterrestrial-samples(93bc14bd-d13f-4d91-ad16-e264754a6e79).html.
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The field of noble gas mass spectrometry is a rapidly developing one. There is a sustained requirement for continuous development of instrumentation in order to allow researchers to answer critical questions facing their respective fields. Within planetary science, the question of whether our solar system is 'typical', has been a driving force behind many lines of research. This project sought to build upon the strong instrumental base of the Isotope Geochemistry and Cosmochemistry group of the University of Manchester, in order to develop the Resonance Ionisation Mass Spectrometer for Krypton Isotopes. From that basis, it then sought to develop techniques and protocols for the analysis of extra-terrestrial samples, particularly those of very low mass. The thesis is broken down into three studies. The first involved the development of the mechanisms used to fill the Xe-Ar four-wave mixing cell. This section covers the development, implementation, and characterisation of the newly installed mass flow controllers. The additional control over the mixing ratio granted allowed an eightfold increase to the sensitivity of the instrument. The reproducibility of the gas ratio is consistently shown throughout, and has ultimately reduced the tuning time of the instrument from a number of weeks to a day. The second section details the required procedures involved in data reduction, and the development of protocols and software for the RIMSKI instrument. A range of approaches are assessed, including a novel approach to cosmic ray exposure age calculations. The methods are discussed and implemented on extra-terrestrial samples, the Stannern eucrite and the Bereba eucrite. Finally, the analytical limits of the RIMSKI instrument are expanded via the measurement of the krypton systems of individual calcium-aluminium-rich inclusions. It is observed that Allende CAIs show a trapped component, Br-derived Kr, as well as an anomalous 'heavy Kr' component (one that is enriched in 86Kr). It is additionally noted that there is a lack of cosmogenic krypton to be found in all but one of the measured inclusions. The implications of these findings are discussed.
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Bourgart, Etienne. "Métabolisme cutané et biomarqueurs d'exposition aux mélanges complexes d'hydrocarbures aromatiques polycycliques A realistic human skin model to study benzo[a]pyrene cutaneous absorption in order to determine the most relevant biomarker for carcinogenic exposure Solar simulated light exposure alters metabolization and genotoxicity induced by benzo[a]pyrene in human skin Influence of exposure dose, complex mixture, and ultraviolet radiation on skin absorption and bioactivation of polycyclic aromatic hydrocarbons." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAS026.
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Les hydrocarbures aromatiques polycycliques (HAP) sont des cancérigènes ubiquitaires, produits en mélanges complexes dont la composition varie en fonction de la source d’émission. Classées substances prioritaires de par leur abondance et leur génotoxicité, l’exposition aux HAP des populations se fait notamment par voie cutanée au cours des activités professionnelles. La surveillance biologique de l’exposition (SBE) tient compte de l’absorption cutanée en plus de l’inhalation et identifie les situations d’exposition à risque. Pour estimer l’exposition au Benzo[a]pyrène (B[a]P), cancérogène certain pour l’homme, le dosage du 3-hydroxybenzo[a]pyrène (3-OHB[a]P) et du (±)trans-anti-B[a]P-tétraol (B[a]P-tétraol) a été récemment proposé. L’objectif de cette thèse était d’étudier l’absorption et le métabolisme cutanés du B[a]P mais aussi des mélanges d’HAP en vue de d’améliorer la compréhension de leur génotoxicité et de développer des biomarqueurs pertinents pour estimer les risques sanitaires. La première partie de ce travail a consisté au développement d’un modèle cutané ex vivo simple mais réaliste à partir d’explants de peau humaine. Après la mise au point des méthodes d’extraction et d’analyse adéquates, la toxico-cinétique et le métabolisme cutané de faibles doses de B[a]P ont été étudiés. La pénétration cutanée et le métabolisme du B[a]P sont inversement proportionnels à la dose appliquée. Cependant, les voies de métabolisation sont impactées différemment. Alors que la production du 3-OHB[a]P issu des voies de détoxication est dose-dépendante, la formation du B[a]P-tétraol, produit de l’hydrolyse du métabolite cancérogène ultime du B[a]P, est rapidement saturée. Le B[a]P-tétraol est donc le biomarqueur le plus pertinent pour estimer le risque cancérogène au B[a]P. De plus, la proportion de B[a]P non-métabolisé traversant la peau est extrêmement limitée indiquant que la toxicité de ce composé s’exprime essentiellement localement. La deuxième partie de ce travail a consisté en une synthèse bibliographique centrée sur la biotransformation de 7 autres HAP cancérogènes permettant d’identifier 16 métabolites d’intérêt commercialisés. In fine, le dosage de 10 de ces métabolites, impliqués dans les voies de bioactivation ou de détoxication de 5 HAP, a pu être développé en GC-MS/MS. Le dosage urinaire de ces nouveaux biomarqueurs devrait permettre d’améliorer la SBE des populations aux HAP cancérogènes. Dans la dernière partie de ce travail, l’impact de la composition de mélanges synthétiques ou industriels (extraits de brai de houille et de coke de pétrole) à différentes doses sur l’absorption et le métabolisme cutanés des HAP furent évalués en présence ou non de rayonnements ultraviolets (UV). La pénétration des HAP diminue quand la complexité du mélange et la dose augmentent. Alors que les UV amplifient la pénétration des HAP lors de l’application des mélanges industriels, ils n’ont pas d’effet sur le B[a]P appliqué seul ou sur les mélanges synthétiques. Leur bioactivation décroit sous l’influence des mélanges et des UV, provoquant une accumulation de HAP non-métabolisés dans la peau ce qui pourrait retarder la survenue des effets génotoxiques. A l’instar du B[a]P, la toxicité des autres HAP cancérogènes semble être essentiellement locale et dépendre du scénario d’exposition cutanée. Ce travail souligne l’importance de l’étude des mélanges du fait d’interactions plus complexes que de simples effets additifsPolycyclic aromatic hydrocarbons (PAH) are ubiquitous carcinogens emitted as complex mixtures whose composition depends on emission sources. Because of their abundance and genotoxicity, PAHs are classified as priority substances, to which people can be exposed via dermal absorption during occupational activities. Biomonitoring takes into account skin absorption as well as inhalation and allows the identification of hazardous exposure situations. To assess Benzo[a]pyrene (B[a]P) exposure, which is classified as carcinogenic to human, quantification of 3-hydroxybenzo[a]pyrene (3-OHB[a]P) and (±)trans-anti-B[a]P-tetrol (B[a]P-tetrol) was recently proposed. This PhD thesis aimed at studying the skin absorption and metabolism of B[a]P and PAH mixtures to improve the understanding of their genotoxicity and develop relevant biomarker for health risk assessment. The first part of this work consisted in developing a simple and realistic skin model from human skin explants. Further to the development of adequate extraction and analytical methods, cutaneous toxicokinetic and metabolism from low B[a]P doses were studied. B[a]P skin penetration and metabolism were inversely proportional to applied dose. Nevertheless, metabolic pathways are impacted differently. While 3-OHB[a]P production formed during detoxification was dose-dependent, the formation of B[a]P-tetrol, resulting from the hydrolysis of B[a]P ultimate carcinogenic metabolite, saturates rapidly. Therefore, B[a]P-tetrol is the most relevant biomarker for estimating B[a]P carcinogenic risk. In addition, unmetabolized B[a]P poorly diffused through skin indicating that B[a]P toxicity is mainly local. The second part of this work consisted of a literature review focusing on 7 other carcinogenic PAH biotransformation to identify 16 marketed metabolites of interest. In fine, GC-MS/MS analysis was developed for 10 previously identified metabolic intermediates that are either involved in bioactivation or detoxification pathways of 5 PAH. Urinary quantification of those new biomarkers should improve the biomonitoring of populations to carcinogenic PAH. Finally, we evaluated the impact of synthetic or industrial mixtures (coal tar pitch and petroleum coke extracts) composition at different doses on carcinogenic PAH skin absorption and metabolism combined or not with ultraviolet radiations (UVR). PAH penetration diminished when mixture complexity and dose increased. While UVR increased PAH penetration when industrial complex mixtures were applied, no effect was observed on pure B[a]P or synthetic mixtures. PAH bioactivation decreased with mixtures and UVR, inducing unmetabolized PAH accumulation in the skin which may delay the occurrence of genotoxic effects. Similarly to B[a]P, other carcinogenic PAH toxicity seems to be mainly local and depends on skin exposure scenario. This work underlines the importance of mixtures study owing to more complex chemical interactions than simple additive effects
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Kray, Jair Gilberto. "Estrutura e estratégias de dispersão do componente arbóreo em uma floresta estacional de encosta no Parque Estadual de Itapuã,sul do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/27520.
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Os objetivos do presente trabalho foram realizar uma análise exploratória da estrutura do componente arbóreo de uma floresta estacional de encosta, relacionando-a a variáveis ambientais, e avaliar os padrões bióticos nas síndromes de dispersão e estratégias de estabelecimento. O estudo foi conduzido no Parque Estadual de Itapuã, Viamão (RS), nas encostas do morro do Campista (30°12´06”S e 51°02´45”O). A análise de correspondência canônica aplicada às relações entre espécies o seu ambiente mostrou que há forte relação entre vegetação, exposição solar das encostas e variações edáficas. Três grupos de unidades amostrais foram determinados relativamente às faces de exposição solar. Observou-se que entre os grupos há diferenças estruturais relacionadas à exposição, tais como aumento da diversidade nas áreas com maior exposição solar e diminuição da área basal média, devido ao menor porte dos indivíduos. As diferentes estratégias de dispersão ocuparam posições distintas ao longo do espaço vertical, e as estratégias de estabelecimento demonstraram as tendências adaptativas das espécies às condições disponíveis no ambiente. As diferenças entre as estruturas florestais e entre as estratégias de estabelecimento das diferentes faces de exposição indicam que a exposição solar, juntamente com fatores edáficos, atua seletivamente sobre as espécies desta formação florestal.In this study, we performed an exploratory analysis of the structure of the arboreal component of a hillside seasonal forest, in order to relate its structure to their environmental variables. In addition, we evaluated the biotic patterns of the dispersal syndromes and establishment strategies. We carried out the research at Parque Estadual de Itapuã, in the slopes of the Campista hill (30°12´06”S and 51°02´45”W). Canonical Correspondence Analysis was used to correlate the species to their environment. The results showed strong relationship among vegetation, solar exposure of the hillsides and edaphic variations. According to their solar exposure, three groups of sampling units were determined. Among these groups, we found structural differences related to solar exposure. In areas with higher exposure, a higher diversity was found, as well as individuals with lower mean basal area, due to their lower height. Different dispersal strategies occupied different positions along the vertical space, whereas the establishment strategies showed the species' adaptive tendencies to environmental available conditions. The differences in the forestry structure, as well as the ones in the species' establishment strategies due to solar exposure, demonstrate that solar exposure together with edaphic factors act selectively on the species in such forestry formations.
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Silva, Mikaelly Batista da. "Influência da exposição solar sobre o perfil de metilação e hidroximetilação global de DNA e em sítios específicos no promotor dos genes miR-9-1, miR-9-3 e MTHFR em amostras de pele humana." Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/9451.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Epigenetics is the study heritable changes of in gene expression without modifications in the primary sequence of DNA. In our study we investigated the influence of sun exposure on global DNA methylation and hydroxymethylation status and at specific sites of the miR-9-1, miR9-3 and MTHFR genes in skin samples of subjects with no history of skin diseases. Skin biopsies were obtained by punch on sun-exposed and sun-protected arm areas from 24 corpses aged 16-89 years old from the Brazilian Service of Death Investigation. Genomic DNA was extracted from skin samples that were ranked according to Fitzpatrick’s criteria as light, moderate and dark brown. Global DNA methylation and hydroxymethylation and DNA methylation at specific sites analyses were performed using an ELISA and MSP, respectively. No significant differences in global DNA methylation and hydroxymethylation levels were found between the skin areas, skin type or age. However, gender-related differences were detected, where women showed higher methylation levels in comparison to those in men. Global DNA methylation levels were higher than hydroxymethylation levels, and the levels of these DNA modifications correlated in skin tissue. For specific sites, it was detected no differences among areas. Additional analyses showed no differences in the methylation status when age, gender and skin type were considered. We conclude that sun exposure does not induce changes in the global DNA methylation and hydroxymethylation status or at specific sites in the miR-9-1, miR-9-3 and MTHFR genes for skin types studied.
A epigenética é o estudo das alterações hereditárias na expressão gênica sem mudanças na sequência primária do DNA. No nosso estudo investigamos a influência da exposição solar sobre o perfil de metilação e hidroximetilação global de DNA e em sítios específicos nos genes miR-9-1, miR-9-3 e MTHFR em amostras de pele humana. Para isso, biópsias foram obtidas por punch circular de área exposta e não exposta ao sol do braço de 24 cadáveres de ambos os sexos, com idade entre 16-89 anos sem histórico de doenças de pele oriundos do Serviço de Verificação de Óbitos da Paraíba (SVO). O DNA foi extraído e a análise de metilação e hidroximetilação global do DNA foi realizada através de Elisa indireto. A análise de metilação nos sítios específicos dos genes miR-9-1, miR-9-3 e MTHFR foi realizada por meio de PCR específica para metilação (MSP) seguida de eletroforese. As análises estatísticas foram realizadas pelo software BioEstat 5.0 ao nível de significância de 5%. Não encontramos diferenças significativas nos níveis de metilação e hidroximetilação global de DNA entre as áreas exposta e não exposta da pele, tipo de pele ou idade. No entanto, foram detectadas diferenças em relação ao gênero, onde as mulheres apresentaram nível de metilação global mais alto em comparação aos homens. O nível de metilação global de DNA foi maior do que o nível de hidroximetilação, sendo estes, correlacionados no tecido da pele. Para sítios específicos, não foi detectada nenhuma diferença entre as áreas. Análises adicionais mostraram não haver diferenças significativas no perfil de metilação quando consideradas a idade, gênero e o tipo de pele. Conclui-se que a exposição ao sol não induz mudanças no perfil de metilação e hidroximetilação global do DNA ou em sítios específicos dos genes miR-9-1, miR-9-3 e MTHFR para os tipos de pele estudado.
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Savoye, Isabelle. "Exposition solaire, compléments alimentaires en antioxydants et risque de cancers cutanés dans la cohorte de femmes E3N." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS555/document.
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Contexte : Les cancers cutanés sont les cancers les plus fréquents dans les populations de peau blanche. Si l’exposition aux rayonnements ultraviolets est le facteur de risque le plus connu, peu d’études ont permis une comparaison directe des profils d’exposition solaire associés à ces tumeurs dans une même population, et les déterminants des comportements d’exposition solaire restent peu connus à ce jour. Par ailleurs, bien que les antioxydants, ayant la capacité de neutraliser les radicaux libres, représentent des candidats potentiels pour la chimioprévention des cancers cutanés, l’état actuel des connaissances ne permet pas d’émettre de conclusion claire en ce qui concerne leur rôle vis-à-vis du risque de cancers cutanés.Objectif : L’objectif de cette thèse est de préciser le lien existant entre l’exposition solaire et le risque de cancers cutanés, d’explorer les profils associés à certains comportements d’exposition solaire et d’étudier les associations potentielles entre compléments alimentaires en antioxydants et risque de cancers cutanés dans l’étude française E3N (Étude Épidémiologique auprès de femmes de l’Éducation Nationale).Résultats : Nos résultats suggèrent que les trois types de cancers cutanés sont associés à différents profils d'exposition solaire et que l’utilisation de crème solaire, de lampes UV et de compléments solaires sont associés à plusieurs habitudes favorables et défavorables pour la santé. De plus, nos résultats suggèrent que les consommations de compléments solaires et de compléments en vitamine E sont associées à un risque accru de carcinomes cutanés.Conclusion : Ce travail souligne l’importance de la prévention pour réduire la prévalence des cancers cutanés ainsi que la nécessité de mieux comprendre les profils associés à différents comportements d’exposition solaire et leur impact potentiel sur les associations avec le risque de cancers cutanés. Par ailleurs, nos résultats ne soutiennent pas l’hypothèse d’un effet protecteur de la consommation de compléments alimentaires en antioxydants vis-à-vis du risque de cancers cutanés et appellent à davantage de recherches afin de mieux comprendre leurs effets à long terme sur la santéBackground: Skin cancers are the most common cancers in white-skinned populations. While exposure to solar radiation is the best known risk factor, few studies have allowed a direct comparison of exposure profiles associated with these tumours within a single population, and little is known about the determinants of sun exposure behaviors. Moreover, although antioxidants, which have the ability of scavenging free radicals, are potential candidates for the chemoprevention of skin cancers, the current state of the literature does not allow to make clear conclusions with regards to their role on skin cancer risk.Objectives: The objective of this thesis is to examine the associations between UV exposures and skin cancer risk, to describe the profiles associated with several sun exposure behaviors, and to explore the potential associations between antioxidant dietary supplements and the risk of skin cancer in the French E3N (Étude Épidémiologique auprès de femmes de l’Éducation Nationale) study.Results: Our results suggest that the three types of skin cancers are associated with different sun exposure profiles and that sunscreen use, sunbed use, and solar supplement use are associated with both healthy and risky behaviors. In addition, our findings suggest that the use of solar supplements and vitamin E supplements is associated with an increased risk of non-melanoma skin cancers.Conclusions: This work emphasizes the importance of prevention to reduce the prevalence of skin cancers as well as the need to better understand the profiles associated with sun exposure behaviors and their potential impact on the associations with the risk of skin cancer. Furthermore, our results do not support the hypothesis of a protective effect of the consumption of antioxidant dietary supplements on the risk of skin cancer and call for more research in order to better understand their long-term effects on health
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Wensveen, Paul J. "Detecting, assessing, and mitigating the effects of naval sonar on cetaceans." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/8684.
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Effective management of the potential environmental impacts of naval sonar requires quantitative data on the behaviour and hearing physiology of cetaceans. Here, novel experimental and analytical methods were used to obtain such information and to test the effectiveness of an operational mitigation method for naval sonar. A Bayesian method was developed to estimate whale locations through time, integrating visual observations with measurements from on-animal inertial, acoustic, depth, and Fastloc-GPS sensors. The track reconstruction method was applied to 13 humpback whale (Megaptera novaeangliae) data sets collected during a multi-disciplinary behavioural response study in Norwegian waters. Thirty-one controlled exposure experiments with and without active transmissions of 1.3-2 kHz sounds were conducted using a moving vessel that towed a sonar source. Dose-response functions, representing the relationships between measured sonar dose and behavioural responses identified from the reconstructed tracks, predicted that 50% of the humpbacks would initiate avoidance at a relatively high received sound pressure level of 166 dB re 1 µPa. Very similar dose-response functions were obtained for cessation of feeding. In a laboratory study, behavioural reaction times of a harbour porpoise (Phocoena phocoena) to sonar-like sounds were measured using operant conditioning and a psychoacoustic method. Auditory weighting functions, which can be used to improve dose-response functions, were obtained for the porpoise based on the assumption that sounds of equal loudness elicit equal reaction time. Additional analyses of the humpback whale data set provided evidence that ramp-up of naval sonar mitigates harmful sound levels in responsive cetaceans located directly in the path of the source, and suggested that a subset of the humpback whale population, such as mother-calf pairs, and more responsive species would benefit from the use of sonar ramp-up. The findings in this thesis are intended to inform sound exposure criteria and mitigation guidelines for anthropogenic noise exposure to cetaceans.
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Marino, Jose. "Long exposure point spread function estimation from solar adaptive optics loop data." Thesis, 2007. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2007-048.
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Liu, Chia-Wei, and 劉家瑋. "Exposure assessment and impact of dust in CIGS thin-film solar manufacturing process." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/35185132128359753078.
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碩士中山醫學大學
職業安全衛生學系碩士班
104
Green energy industry in Taiwan are solar,wind farm,LED light and green building. Solar is the most important of green industry in Taiwan. Thin-film solar module is new industry,and wasn’t any study about exposure hazardous for Selenium (Se). This study is to investigate fugitive dust of Selenide process. A descriptive survey design was analysis Se exposure from operator and worker of preventive maintenance. And give engineering or management control that workers exposure concentration in workplace. Environmental sampling by Marple and IOM, the Marple d50 is 0.13、0.52、0.96、1.55、3.5、6.0、9.8、14.8、21.3 (μm), with 34mm,0.5μm PVC filter paper ;and IOM with 25mm, 5μm MCE filter paper. Personal sampling by cyclone with 30mm,0.8μm MCE filter paper.All analysis are gravimetric method. The environmental sampling of concentration was 9.660 mg/m3、5.226mg/m3、5.929 mg/m3、6.106 mg/m3、13.371mg/m3,all over 0.2 mg/m3 the limit of Se.Dust fugitive was not from start and period of Selenide process,but when the chamber open there will star fugitive and decreaseto background concentration period short time.The main exposure of workers is every process of preventive maintenance.Separticle size is d50:0.13~d50:1.55,it means that easy to go into the deep lung. We can reduce dust exposure of metal and Se probability by shift. Improvement fugitive by increase machine extraction ventilation or purgetime.Also wear PPE when working.(Ex. Powered Air Respirator)
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陳品竹, Pin-Chu Chen, and 陳品竹. "Slanted Grating Manufacturing for the Luminescent Solar Concentrator Using the Canted Exposure Method." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/77614422729628900124.
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碩士國立中興大學
機械工程學系所
104
This research was focused on the optical efficiency improvement of the luminescent solar concentrator (LSC). This research combines the slanted grating with the design of the LSC. By adjusting the structure, period, and depth, the incident light can be diffracted into specific orders. It could have the purposes of increasing the transfer efficiency of fluorescent dyes and reducing the area of solar cell usage. First, the diffraction equation was applied to the calculation of both the critical angle for total reflection and the grating period for diffraction in the waveguide. Then, the granting simulation software, Gsolver, was used to analyze the granting structures with different shapes. By investigating the diffraction efficiencies among different orders for grating parameters, the optimal grating design values could be found. In the experiment, the slanted gratings with periods of 4 µm and 6 µm, which have the duty cycle of 50%, were fabricated by the canted exposure method. The photoresist was used as the grating structures. After the lithographic process, the devices were measured for the light intensities of all diffraction orders. Furthermore, different process parameters were tested for comparing the measured results with those of the optical simulation and verifying the feasibility of the manufacturing. Finally, the slanted grating was glued with the fluorescent dye by UV glue for fabricating a compact LSC. In order to verify the design feasibility, waveguide effects were measured and compared with samples of various parameters.
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Chen, Yu-Chieh, and 陳玉潔. "Health hazards from over-exposure to solar ultraviolet light and thermal stress and efficacy of sunscreens." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/47161564997755205129.
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碩士中國醫藥大學
職業安全衛生學系碩士班
98
With the deterioration of atmospheric ozone and global warming continuing, the risks of exposure to solar UV radiation and heat stress have exacerbated in the last decades, and people nowadays have become increasingly familiar with the use of protective mechanisms. The research described in this thesis quantitatively investigated the physiological changes in the sunscreen- protected vs. -unprotected human skin in response to exposure to solar UV radiation and thermal stress. The skin physiology-based indicators were also applied to evaluate the effectiveness of sunscreen rendering protection when used in hot and humid areas such as Taiwan. The physiological indicators selected in the study included skin blood flow change (SBFC), transepidermal water loss (TEWL), skin temperature, skin moisture, erythema (E-index), and melanogenesis (M-index). Subjective thermal sensation was also gauged, using a standardized questionnaire developed by the American Society of Heating, Refrigerating, and Air-conditioning Engineers Standard 55. The research was conducted in two successive stages, the first being conducted outdoors to evaluate the immediate/prolonged changes in skin physiology of the subjects under the sun or in the shadow (the solar UV study) and the second to examine the patterns of physiological adjustment in response to alteration in thermal microclimate (the exposure chamber study). In both studies, the physiological indicators and thermal sensation of the treatment group (using sunscreens) and control group (not using sunscreens) were simultaneously assessed to develop dose-response relationships between dermal indicators and physical variables and to investigate any variations between physiological and psychological indicators, particularly as a result of sunscreen application. The results of the solar UV study show: SBFC was a physiological indicator highly sensitive to change in solar irradiation and microclimatic factors, thus serving well as a pre-clinical indicator. TEWL, skin moisture, and E-index well indicated the acute health hazard resulting from short-term solar UV irradiation. TEWL and E-index among all physiological indicators best differentiated the efficacy of sunscreen protecting against solar UV radiation at a level of UV Index 6 or less. As observed in the exposure chamber study, SBFC, TEWL, and skin temperature responded linearly to the alteration in environmental temperature, but less to the influence of relative humidity (RH). In contrast, skin moisture was the only indicator responded to influences from both environmental temperature and RH. Among the physiological indicators, skin temperature first changed in response to alteration in environmental temperature, and then SBFC increased to circulate the excess body heat to skin surface for dissipation. The skin moisture increased next to expel the heat absorbed in skin moisture to the skin surface. Once the moisture in the skin saturated, TEWL dramatically rose to evaporate water in stratum corneum. The heat dissipation cycle ended with the skin temperature being re-equilibrated with the thermal environment. As for the psychological indicator, the thermal sensation votes (TSVs) of the participants were influenced proportionally by alterations in the examined thermal factors, particularly the environmental temperature. The TSV was most significantly correlated to skin temperature (R2 > 0.75).
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Wu, Chieh-Ming, and 吳介銘. "Developing Biological Indicators for Alerting Health Hazards of Exposure to Thermal Stress and Solar UV Irradiation." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/10994807509802227152.
Full textAbstract:
碩士中國醫藥大學
職業安全衛生學系碩士班
97
The exposure of human skin to physical agents present in the environment—solar UV radiation and heat stress—has long been recognized as a health risk, and in the last decades this risk has been exacerbated with the formation of urban heat island effect and the global warming due to depletion of stratospheric ozone. Currently, the Global Solar UV Index (UVI) system and Wet-Bulb Globe Temperature (WBGT) are the predominant tools of communication for the hazards resulting from over-exposure to UV irradiation and heat stress, respectively. The UVI ranks the potential hazard of exposure based on the solar irradiance reaching the earth’s surface and correspondingly suggests recommendations of protection. The WBGT reports the intensity of thermal factors present in the indoor or ambient environment. As of current, both systems do not causally relate, in (semi-)quantitative terms, the exposure level to the potential human health impact that may arise from over-exposure to solar UV irradiation or heat stress. Consequently, these systems in their current formats are limited from providing warnings to information users on the health hazard resulting from excess exposure to UV irradiation, heat stress, or both. This thesis aims to quantitatively investigate the changes in human skin physiology and in thermal sensation in response to exposure to various thermal factors in the environment, including solar UV radiation, so to evaluate the applicability of these changes as an indicator to health hazards from over-exposure. The skin physiological responses attempted as biomarkers included transepidermal water loss (TEWL), skin temperature, skin moisture, erythema (reported as erythema-index, E-index), and melanogenesis (reported as melanin-index, M-index). Subjective thermal sensation was gauged using a standardized questionnaire developed by the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 55. The research as described in this thesis was conducted in three major stages. In the first stage (the preliminary study), study participants were investigated for the changes in the aforementioned physiological indicators in a climatic chamber to determine the skin exposure and control sites appropriate for evaluation in the succeeding stages. The second stage (the exposure chamber study) assessed the variations in objective biomarkers and subjective sensation in response to alternation in environmental temperature and relative humidity (RH); the results were then analyzed to establish the dose-response relationships between physiological indicators and thermal exposure, the time-course relationships among physiological indicators, and the potential variance between physiological and psychological indicators. The third stage, the solar UV exposure study, was conducted outdoors on campus twice a week for a total period of six weeks. In this stage, the biomarkers were evaluated for their changes following short- and long-term solar UV radiation, and, similar to the second stage, attempts were made to develop dose-response relationships between biomarkers and examined physical forces and to investigate any variations between physiological and psychological indicators. Simultaneously collected in this stage were the hourly UVI forecasts monitored in the Taichung area by the Central Weather Bureau, Taichung Meteorological Station for evaluation of immediate and cumulative solar UV irradiance reaching the campus where the study took place. The results show: among all evaluated positions, the skin at outer forearm and sleeve-covered inner upper arm shared a similar level of stable response in all examined skin physiological indicators upon thermal challenge, thus were selected as the exposure and control sites in all succeeding studies. Based on the results of exposure chamber study, TEWL and skin temperature changed significantly with environmental temperature, but responded less to RH. The skin moisture was the only of the above indicators that reflected the alteration in both environmental temperature and RH. The events of physiological changes as suggested by experimental observations were: 1) skin temperature directly tracked the change in environmental temperature; 2) skin moisture increased in response to requirement of heat dissipation; and 3) as skin moisture peaked TEWL rose remarkably and eventually leading to substantial sweating-resembling evaporation. The E-index and M-index did not change with varying environmental temperature and RH. As for the psychological indicator, the thermal sensation votes (TSVs) of the participants were influenced proportionally by alterations in the examined thermal factors, particularly the environmental temperature. The TSV was most significantly correlated to skin temperature (r > 0.868). The results from solar exposure study show that skin moisture and melanogenesis were better indicators of potential health hazards from single and cumulative solar UV radiation, respectively, than the others. Erythema as reported in M-index corresponded linearly to cumulative solar UV exposure for the female participants, but did not reflect acute injury if any, possibly due to the low intensity of solar UV radiation at Taichung during the period of investigation. The outdoor thermal sensation was markedly influenced by the radiant heat; the variation between the physiological and psychological indicators was most significant when the participants were in the period of thermal adaptation or in a thermal transition zone. The distributions of E-index against UVI and M-index against cumulative UV irradiance were linearly regressed to establish dose (UV irradiance)-response (quantifiable biomarker change) relationships that may be applied in hazard exposure assessments and as a warning tool of harmful UV exposures.
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Gaspar, Gabriela Ferreira. "Risk normalization in sunlight exposure." Master's thesis, 2017. http://hdl.handle.net/10071/16261.
Full textAbstract:
The present study focuses on the understanding of whether there is a process of risk
normalization, due to the use of positive illusions, in individuals who expose themselves to
sunlight on the beach. A pilot study (N = 44) evidenced that the positive illusions most referred
are the use of protective measures during exposition at unrecommended time. To understand
whether knowledge of sunlight exposure risks and risk perception could be negatively
associated, due to the use of protective measures, a questionnaire was applied to a convenience
sample (N = 276). The sample was reduced in two groups that reported being exposed between
12 am and 3 pm - low protective behaviors (n = 74) and high (n = 41). Results illustrate the
normalization process only in individuals who have high protection behaviors, as expected. The
effect of moderating variables was also tested: mediation of the consequences of risk in time
and health literacy in the relation between knowledge of risks and risk perception. Only health
literacy had a significant effect, decreasing normalization. The role of knowledge of benefits
was also explored. It was positively related to risk perception and this relation was moderated
by mediation in time.
This study suggests that it is important to a) warn that the use of protective measures
during the hazardous time does not guarantee immunity, b) promote health literacy, as it can
minimize risk normalization c) understand how information on risks and benefits interact to
influence risk perception.O presente estudo tem como objetivo explorar a existência de um processo de normalização de risco, devido à utilização de ilusões positivas, nos indivíduos que se expõem ao sol na praia. Com base num estudo piloto (N = 44) aferiu-se que as ilusões positivas mais referidas pelos indivíduos são a utilização de medidas de proteção complementares, como o protetor solar ou a ingestão de água, ao invés da não exposição ao sol durante o horário considerado mais perigoso (12h-15h). Para compreender se a utilização destas medidas de proteção se poderia associar a um processo de normalização de risco à exposição solar, aplicouse um questionário (N = 276) a uma amostra de conveniência, que foi reduzida em dois grupos tendo por base a média dos comportamentos de proteção – baixos comportamentos de proteção (n = 74) e altos comportamentos de proteção (n = 41). Os resultados indicam que existem diferenças entre as amostras relativamente ao processo de normalização de risco. Como esperado, para os indivíduos que têm elevados comportamentos de proteção e se expõem ao sol no horário mais perigoso existe uma relação negativa entre o conhecimento de risco e a perceção de risco da exposição solar (i.e., existe normalização de risco) mas não nos indivíduos que se expõem fora desse horário. Foi também testado o efeito de variáveis moderadoras: mediação das consequências do risco no tempo e literacia em saúde na relação entre conhecimento e perceção de risco. Apenas a literacia em saúde teve um efeito significativo, tendo contrariado o efeito de normalização. Sendo que nos últimos anos se tem enfatizado também os benefícios da exposição solar, explorou-se ainda qual seria a relação entre o conhecimento de benefícios e a perceção de risco e qual o papel das variáveis moderadoras. Verificou-se a existência de uma relação positiva entre conhecimento de benefícios e perceção de risco de exposição solar, sendo esta relação moderada pela mediação das consequências do risco no tempo. Quando os indivíduos consideram que as consequências do risco são tardias, o conhecimento de benefícios associa-se a uma menor perceção de risco. Este estudo tem implicações que poderão ser relevantes para a comunicação do risco. Em particular importa: a) alertar que a utilização de medidas de proteção durante o horário mais perigoso não garante imunidade ao risco da exposição solar; b) apostar na promoção em literacia em saúde para minimizar a normalização de riscos; c) compreender como os riscos e os benefícios associados à exposição solar interagem para influenciar a perceção de risco
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Nicolaou, Anna, Mojgan Masoodi, Karl Gledhill, A. K. Haylett, Anthony J. Thody, Desmond J. Tobin, and L. E. Rhodes. "The eicosanoid response to high dose UVR exposure of individuals prone and resistant to sunburn." 2011. http://hdl.handle.net/10454/5229.
Full textAbstract:
NoHigh personal UVR doses can be gained during leisure activities, causing intense self-resolving inflammation (sunburn) of unprotected skin. UVR activates release of membrane fatty acids and upregulates their metabolism by cyclooxygenases (COX) and lipoxygenases (LOX) to different eicosanoids. While COX-derived prostaglandin (PG)E2 is a potent mediator of sunburn vasodilatation, LOX-derived 15-hydroxyeicosatetraenoic acid (HETE) and its lipoxin metabolites may contribute to sunburn limitation. We explored the relationships between expression of these lipid mediators and the clinical and histological outcomes, comparing responses of individuals prone and more resistant to sunburn. An acute UVR exposure of 12 SED (standard erythema dose) was applied to buttock skin of 32 white Caucasians (n = 16 phototype I/II, n = 16 phototype III/IV), and over the subsequent 72 h assessments were made of skin erythema, immunohistochemical expression of leukocyte markers, COX-2, 12-LOX, 15-LOX and nitric oxide synthase (NOS), and eicosanoid levels by LC/ESI-MS/MS. Evidence of a significant inflammatory response was seen earlier in phototype I/II with regard to expression of erythema (4h, p < 0.001), neutrophil infiltration (24 h, p = 0.01), epidermal COX-2 (24 h, p < 0.05) and 12-LOX (24 h, p < 0.01), and dermal eNOS (24 h, p < 0.05) proteins, although CD3+ lymphocyte infiltration showed an earlier increase in phototype III/IV (24 h, p < 0.05). Although erythema was equivalent at 72 h in both groups, phototype I/II showed higher PGE2 accompanied by elevated 15-HETE, and a strong positive correlation was seen between these mediators (n = 18, r = 0.805, p = 0.0001). Hence anti-inflammatory eicosanoid 15-HETE may temper the pro-inflammatory milieu in sunburn, having greater influence in those prone to sunburn than those more resistant, given the same high UVR exposure conditions.
The Wellcome Trust
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Kitchin, Dale John. "The effects of in vivo passaging, solar radiation exposure and inoculum dose on the genetic diversity of Helicoverpa armigera nucleopolyhedrovirus." Thesis, 2017. https://hdl.handle.net/10539/26508.
Full textAbstract:
A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degreeofDoctor of Philosophy, Johannesburg 2017The nucleopolyhedroviruses (NPVs) are a group of entomopathogenic viruses, with large double-stranded DNA genomes, which belong to the Baculoviridae family. Considerable genetic diversity is known to exist within NPV populations, with a number of studies having shown that NPV populations consist of multiple genotypes. Studies have also shown that the genotypic composition of NPV populations can vary between different host individuals and geographical locations. Yet, how this genetic diversity is generated and maintained in NPV populations over successive infections is not fully understood. In this study, a denaturing gradient gel electrophoresis (DGGE) assay and deep amplicon sequencing were used to assess the effects of serial in vivo passaging, pre-infection exposure to solar radiation and occlusion derived virion (ODV) inoculum dose on the genetic diversity of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) populations within regions of the DNA polymerase and me53 genes. The serial in vivo passaging of a HearNPV population, using a high OB inoculum dose (LD90 × 5), did not result in a common or similar genotypic composition in the 125 third passage HearNPV populations isolated from individual host insects. Shifts in the relative abundance of inoculum genetic variants and the generation of novel genetic variants caused the HearNPV populations isolated from individual insects to diverge in genetic variant composition over the three serial in vivo passages. Although pre-infection exposure of HearNPV OBs to solar radiation did not increase the frequency at which novel genetic variants were generated over the course of an infection, it did appear to contribute to the divergence in genetic variant composition of HearNPV populations over in vivo passages. It was also observed that the higher the ODV inoculum dose the greater the probability that the genetic variant composition of the post-passage HearNPV population would resemble that of the inoculum population. Overall it was shown that in vivo passaging, pre-infection exposure of OBs to solar radiation and ODV inoculum dose all affect the genotypic composition of HearNPV populations. The findings of this study contribute to the understanding of the factors that affect the generation and maintenance of HearNPV genetic diversity over the course of an infection and provide insights into how the genetic diversity between distant geographical HearNPV isolates may develop in the field.
XL2019
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Chang, Shih-Yin, and 張詩吟. "Thermal Loading and Subsequent Adaptation in Response to Simulated Solar Radiant Heat Exposure and Influences of Sunscreen Use on Thermoregulation." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/41336909250410665460.
Full textAbstract:
碩士中國醫藥大學
職業安全與衛生學系碩士班
101
Solar radiant heat is amongst the most significant meteorological factors affecting metabolic heat load when people remain outdoors. In recent years, the frequent appearance of high ambient temperature in association with global climate change presents an increasing challenge to the physiological capacity of heat load and to that of thermoregulation. Among the affected, those who live and/or work in the urban areas are of particular concern—the thermal transient developed between the entrance of an air-conditioned building and the ambient environment often increases the thermal stress imposed on human body when people enter/leave the building. To prevent injury from over-exposure to solar radiation, the sunscreens are commonly adopted as a strategy of self protection. This study aimed to, by means of a series of experiments conducted in dual microclimatic chambers simulating different combinations of solar radiation, environmental temperature, and non-climatic factors including the use of sunscreens and the sex, investigate the physiological/psychological responses of human body to and the balance with thermal stress when the body is confronted with a thermal environment of either a steady state or a transient state due to a drop in environmental temperature following loss of solar radiant heat. The physiological indicators selected in the study were those of body core and of skin physiology involved in the dissipation of metabolic heat. The core indicators consisted of metabolic rate and core temperature, while the dermal physiological indicators included skin capillary blood flow, skin moisture, transepidermal water loss, and skin temperature. The subjective thermal sensation and thermal comfort were also gauged, using a standardized questionnaire developed by the American Society of Heating, Refrigerating, and Air-conditioning Engineers Standard 55. The study findings were analyzed to interpret the progress of heat acclimation (thermal adaptation), the time course of physiological responses as driven by thermoregulatory requirement, the relationship of dose (thermal exposure) and response for each individual event of thermoregulation, and the roles of the radiant heat as well as of using sunscreens in the aforementioned relationships. As the results show, the metabolic heat load and thermoregulation occurring in response to radiant heat exposure was greater and required a longer period to acclimatize compared to those resulting from exposure to the air temperature. These physiological changes in feedback to thermal pressure were particularly pronounced for males, as manifested in the alteration of skin moisture and transepidermal water loss, when not using sunscreens and thermally challenged at a globe temperature of 32oC. Upon entering the thermal transient developing from the sudden loss of radiant heat, the skin capillary blood flow and skin temperature required a longer period to re-equilibrate with the ambient environment compared to the requirements observed when the transient arose entirely as a result of air temperature step, suggesting a potential residual effect of radiant heat in delaying the thermoregulation occurring in response to the transient thermal environment. Using sunscreens reduced the burning sensation on the skin following exposure to solar radiation. In addition, the cooling effect of sunscreens significantly alleviated the metabolic heat load and thermoregulation resulting from exposure to radiant heat and from exposure to the thermal transient developing from a disappearance of solar raidation. The thermal comfort of females was more associated with the thermal sensation compare to that of males. These findings provide insights on how the current indices of thermal stress may be improved and promote a better understanding on the effects of using sunscreens in hot-and-humid areas such as Taiwan, protecting people from being thermally stressed from being exposed to solar radiation, particularly in hot summer days.
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Pilkington, S. M., Karen A. Massey, S. P. Bennett, Naser M. I. Al-Aasswad, K. Roshdy, N. K. Gibbs, P. S. Friedmann, Anna Nicolaou, and L. E. Rhodes. "Randomized controlled trial of oral omega-3 PUFA in solar-simulated radiation-induced suppression of human cutaneous immune responses." 2013. http://hdl.handle.net/10454/7255.
Full textAbstract:
noBackground: Skin cancer is a major public health concern, and the majority of cases are caused by solar ultraviolet radiation (UVR) exposure, which suppresses skin immunity. Omega-3 (n−3) PUFAs protect against photoimmunosuppression and skin cancer in mice, but the impact in humans is unknown. Objectives: We hypothesized that EPA-rich n−3 PUFA would abrogate photoimmunosuppression in humans. Therefore, a nutritional study was performed to assess the effect on UVR suppression of cutaneous cell-mediated immunity (CMI) reflected by nickel contact hypersensitivity (CHS). Design: In a double-blind, randomized controlled study, 79 volunteers (nickel-allergic women, 22–60 y old, with phototype I or II) took 5 g n−3 PUFA–containing lipid (70% EPA plus 10% DHA) or a control lipid daily for 3 mo. After supplementation, nickel was applied to 3 skin sites preexposed on 3 consecutive days to 1.9, 3.8, or 7.6 J/cm2 of solar-simulated radiation (SSR) and to 3 unexposed control sites. Nickel CHS responses were quantified after 72 h and the percentage of immunosuppression by SSR was calculated. Erythrocyte [red blood cell (RBC)] EPA was measured by using gas chromatography. Results: SSR dose-related suppression of the nickel CHS response was observed in both groups. Photoimmunosuppression appeared less in the n−3 PUFA group than in the control group (not statistically significant [mean difference (95% CI): 6.9% (−2.1%, 15.9%)]). The difference was greatest at 3.8 J/cm2 SSR [mean difference: 11% (95% CI: 0.5%, 21.4%)]. Postsupplementation RBC EPA was 4-fold higher in the n−3 PUFA group than in the control group (mean difference: 2.69% (95% CI: 2.23%, 3.14%), which confirmed the EPA bioavailability. Conclusion: Oral n−3 PUFAs appear to abrogate photoimmunosuppression in human skin, providing additional support for their chemopreventive role; verification of study findings is required.
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"Failure and Degradation Modes of PV modules in a Hot Dry Climate: Results after 16 years of field exposure." Master's thesis, 2013. http://hdl.handle.net/2286/R.I.20959.
Full textAbstract:
abstract: This study evaluates two 16 year old photovoltaic power (PV) plants to ascertain degradation rates and various failure modes which occur in a "hot-dry" climate. The data obtained from this study can be used by module manufacturers in determining the warranty limits of their modules and also by banks, investors, project developers and users in determining appropriate financing or decommissioning models. In addition, the data obtained in this study will be helpful in selecting appropriate accelerated stress tests which would replicate the field failures for the new modules and would predict the lifetime for new PV modules. The two power plants referred to as Site 4A and -4B with (1512 modules each) were initially installed on a single axis tracking system in Gilbert, Arizona for the first seven years and have been operating at their current location in Mesa, Arizona for the last nine years at fixed horizontal tilt Both sites experience hot-dry desert climate. Average degradation rate is 0.85%/year for the best modules and 1.1%/year for all the modules (excluding the safety failed modules). Primary safety failure mode is the backsheet delamination though it is small (less than 1.7%). Primary degradation mode and reliability failure mode may potentially be attributed to encapsulant browning leading to transmittance/current loss and thermo-mechanical solder bond fatigue (cell-ribbon and ribbon-ribbon) leading to series resistance increase. Average soiling loss of horizontal tilt based modules is 11.1%. About 0.5-1.7% of the modules qualify for the safety returns under the typical 20/20 warranty terms, 73-76% of the modules qualify for the warranty claims under the typical 20/20 power warranty terms and 24-26% of the modules are meeting the typical 20/20 power warranty terms.Dissertation/Thesis
M.S.Tech Engineering 2013
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"Failure and Degradation Modes of PV modules in a Hot Dry Climate: Results after 4 and 12 years of field exposure." Master's thesis, 2013. http://hdl.handle.net/2286/R.I.20948.
Full textAbstract:
abstract: This study evaluates two photovoltaic (PV) power plants based on electrical performance measurements, diode checks, visual inspections and infrared scanning. The purpose of this study is to measure degradation rates of performance parameters (Pmax, Isc, Voc, Vmax, Imax and FF) and to identify the failure modes in a "hot-dry desert" climatic condition along with quantitative determination of safety failure rates and reliability failure rates. The data obtained from this study can be used by module manufacturers in determining the warranty limits of their modules and also by banks, investors, project developers and users in determining appropriate financing or decommissioning models. In addition, the data obtained in this study will be helpful in selecting appropriate accelerated stress tests which would replicate the field failures for the new modules and would predict the lifetime for new PV modules. The study was conducted at two, single axis tracking monocrystalline silicon (c-Si) power plants, Site 3 and Site 4c of Salt River Project (SRP). The Site 3 power plant is located in Glendale, Arizona and the Site 4c power plant is located in Mesa, Arizona both considered a "hot-dry" field condition. The Site 3 power plant has 2,352 modules (named as Model-G) which was rated at 250 kW DC output. The mean and median degradation of these 12 years old modules are 0.95%/year and 0.96%/year, respectively. The major cause of degradation found in Site 3 is due to high series resistance (potentially due to solder-bond thermo-mechanical fatigue) and the failure mode is ribbon-ribbon solder bond failure/breakage. The Site 4c power plant has 1,280 modules (named as Model-H) which provide 243 kW DC output. The mean and median degradation of these 4 years old modules are 0.96%/year and 1%/year, respectively. At Site 4c, practically, none of the module failures are observed. The average soiling loss is 6.9% in Site 3 and 5.5% in Site 4c. The difference in soiling level is attributed to the rural and urban surroundings of these two power plants.Dissertation/Thesis
M.S.Tech Engineering 2013
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Braun, Gunnar Johannes. "Ermittlung des Wissensstandes über Schutzmaßnahmen gegen solare Exposition in Mitgliedsbetrieben als Grundlage für die präventive Tätigkeit der BG ETEM." Master's thesis, 2017. https://diu.qucosa.de/id/qucosa%3A21598.
Full textAbstract:
In dieser Masterthesis wird erforscht wie der jetzige Kenntnisstand der Sicherheitsfachkräfte zu den Themen solare Exposition, Schutzmaßnahmen und die Akzeptanz der Schutzmaßnahmen durch die Mitarbeiter in den Mitgliedsbetrieben der BG ETEM ist. Diese Themen gewinnen an Bedeutung seit die Berufskrankheit Nummer 5103 in den Anhang 1 der Berufskrankheitenverordnung aufgenommen wurde und die BG ETEM nun für ihre Versicherten auch diesbezüglich präventiv tätig ist.
Im Rahmen dieser Masterthesis wurde für die Erforschung des Kenntnisstands ein Fragebogen mit zugehörigem Interviewleitfaden selbst entwickelt. Die anschließenden Befragungen wurden durch den Ersteller in den teilnehmenden Unternehmen persönlich für die Masterthesis vorgenommen. Der Teilnehmerkreis beschränkt sich auf interne Sicherheitsfachkräfte, die in Unternehmen der Branche Energie- und Wasserwirtschaft beschäftigt sind. Erforscht werden neben allgemeinen und betrieblichen Angaben ihr Kenntnisstand zu den Themengebieten Gefährdungsbewusstsein, Gefährdungsbeurteilung, Schutzmaßnahmen und der Informations- und Fortbildungsbedarf. Die Antworten werden mit den eigenen Erwartungen verglichen und Rückschlüsse daraus gezogen. Für die BG ETEM werden die Ergebnisse dieser Masterthesis im Hinblick auf den Präventionsauftrag analysiert. Hierzu werden im Rahmen der Masterthesis auch Vorschläge zu diesen Maßnahmen gemacht. So sollen die Beratungen, Informationsmaterialien und Fortbildungen auf die Präferenzen sowie die vorhandenen Wissenslücken in den Unternehmen zugeschnitten werden, um hier berufsbedingte Neuerkrankungen durch solare Exposition langfristig weitgehend zu verhindern.