L’acide rétinoïque (AR) est requis pour de nombreuses fonctions physiologiques parmi lesquelles la reproduction. Il est synthétisé par des rétinaldéhyde déshydrogénases (RALDH1 à 3) et il active la transcription de gènes cible en se liant à ses récepteurs nucléaires RAR (α,β,γ). L’objet de mon travail de thèse a été d’étudier les fonctions de l’AR, produit dans les cellules de Sertoli testiculaire, sur la spermatogenèse de la souris. Ainsi, par l’étude de l’inactivation des gènes des RALDH spécifiquement dans les cellules de Sertoli murines grâce à la mutagenèse somatique, j’ai montré que les cellules de Sertoli dirigent la première différenciation des cellules germinales grâce à leur production d’AR qui est ensuite dispensable au bon déroulement de la spermatogenèse. L’induction de cette première spermatogenèse est possible par l’activation sélective de RAR qui est à la base d’une pléiade de voies de signalisation. J’ai également confirmé le rôle crucial de la voie de signalisation de l’AR dans les cellules de Sertoli pour la spermiation, dernière étape du processus de spermatogenèse, et donc pour la fertilité. Enfin, j’ai démontré la nécessité in vivo de la signalisation par l’AR pour la méiose, qui contrôle l’expression de Stra8, un gène essentiel pour la progression méiotique. Cette régulation se fait de manière cellulaire autonome et requiert la fixation d’un RAR sur son élément de réponse localisé dans la région promotrice de Stra8. / Retinoic acid (RA) is required for many physiological functions including reproduction. It is synthesized by retinaldehyde dehydrogenases (RALDH1 to 3) and activates transcription of target genes by binding to its nuclear receptors (RAR α,β,γ ). The purpose of my thesis was to study the functions of RA produced in testicular Sertoli cells in spermatogenesis in the mouse. Thus, by studying the effects of RALDH selective inactivation in murine Sertoli cells by somatic mutagenesis, I showed that Sertoli cells direct the first differentiation of germ cells through their production of RA, which is then dispensable for the proper conduct of spermatogenesis. Induction of the first spermatogenesis is possible by selective activation of RAR, which is at the basis of several signaling pathways. I also confirmed the crucial role of the RA pathway in Sertoli cells for spermiation, the final stage of spermatogenesis, and therefore fertility. Finally, I demonstrated the need of an in vivo RA signaling for meiosis, which controls the expression of Stra8, a gene essential for meiotic progression. This regulation is done cell-autonomously and requires the binding of a RAR on its response element located in the promoter region of Stra8.

Integration of power optimizers in photovoltaic systems is standard practice in some parts of the world. Manufacturers claim that optimizers can significantly reduce electrical losses due to shading. Hence, it is important to investigate this claim and determine under what conditions it is economically warranted to utilize optimizers. In this thesis systems were modelled in PVSyst, for 6 different locations: Abu Dhabi, Borlänge, Madrid, New Delhi, Sydney, and Vienna. In each location there were 3 types of systems: a regular non-optimised system, a SolarEdge optimised system and a TIGO optimised system. Each of these systems had 10 variants where the amount of shading was varied. The system variants were simulated in PVSyst and the effect of power optimizers on electrical losses due to shading was analysed. Afterwards, payback periods were calculated for each system to determine under which conditions power optimizers are economically feasible. It was found that power optimizers significantly reduce electrical losses due to shading. In some scenarios, the losses were reduced by up to 58 %. However, in the current economic climate in 2018, it is not feasible to incorporate power optimizers, in photovoltaic systems in Abu Dhabi, New Delhi or Sydney. Furthermore, in Borlänge, Madrid, and Vienna, optimizers are only feasible if there are high levels of shading, which is not realistic for a regular photovoltaic system.

A presente pesquisa teve por objetivo conhecer as concepções de alunos de Ensino Médio em relação à fotossíntese e a cadeia alimentar e aplicar a metodologia Módulo Didático visando favorecer o processo ensino-aprendizagem. A metodologia Módulo Didático, concebida por Delizoicov e Angotti (1990), consiste em três etapas: problematização inicial (PI), organização do conhecimento (OC) e aplicação do conhecimento (AC). A pesquisa foi desenvolvida com uma classe de 35 alunos do 1º Ano do Ensino Médio de uma escola pertencente à Rede Estadual de Ensino, localizada no município de Lorena, SP. O desenvolvimento da pesquisa ocorreu em quatro etapas: aplicação de um questionário socioeconômico e de uma avaliação diagnóstica inicial, desenvolvimento do Módulo Didático, aplicação de uma avaliação diagnóstica final ao término da aplicação da metodologia e uma nova aplicação da avaliação diagnóstica final após o período de férias escolares dos discentes. A aplicação da metodologia foi pautada no pluralismo metodológico por meio dos seguintes recursos: questões problematizadoras, leitura e análise de textos de divulgação científica, vídeos, simuladores, jogo e mapa conceitual. Dentre os resultados relacionados à análise do perfil socioeconômico dos discentes, percebeu-se que 41% possui preferência por desenvolver as atividades em um grupo pequeno, enquanto 38% tem preferência por trabalhar com outra pessoa. A análise comparativa das avaliações diagnósticas inicial, final e final após o período de férias escolares revelou tendências ao se considerar o processo ensino-aprendizagem de fotossíntese e de cadeia alimentar. Para a temática fotossíntese, alguns assuntos necessitam ser abordados a partir de recursos distintos dos utilizados para o desenvolvimento da pesquisa, uma vez que não houve efetividade no conhecimento construído; para outros, o conhecimento construído se mostrou efetivo. Em relação à temática cadeia alimentar, o conhecimento construído apresentou efetividade. Os resultados obtidos, portanto, revelaram que o Módulo Didático se constitui como uma estratégia metodológica viável para desenvolvimento com alunos de Ensino Médio. A efetividade do processo ensinoaprendizagem está atrelada a outros fatores condicionantes, tais como os recursos utilizados, o modo pelo qual os discentes preferem desenvolver as atividades bem como o número de alunos por classe. / The following research has the aim to discover the views of secondary school (high school) students in relation to photosynthesis and the food chains, and the application of the Didactic Module methodology to facilitate the teaching-learning process. The Didactic Module methodology, designed by Delizoicov and Angotti (1990), consists of three stages: initial questioning, organization of knowledge, and the application of knowledge. The research was conducted with a class of 35 students from the 1st year of a secondary school which belonged to a network of public schools, located in the city of Lorena, SP. The development of the research took place in four steps: the application of a socioeconomic questionnaire and an initial diagnostic evaluation, the development of the Didactic module, the application of a final diagnostic evaluation at the end of the methodology application and a new application of the final diagnostic evaluation after a period of the student\'s school holidays. The methodology was based on methodological pluralism through the following resources: questions which cause problems, the reading and the analysis of scientific texts, videos, simulators, games and concept map. Among the results related to the analysis of the socioeconomic profile of students, it was noticed that 41% have preference for developing activities in a small group, while 38% have a preference for working with someone else. The comparative analysis of the diagnostic evaluations from the beginning, middle and end of the school holiday period revealed trends when considering the teaching-learning process of photosynthesis and the food chain. For the theme photosynthesis, some issues need to be addressed from different resources used for the development of the researches, since there was no effectiveness in the knowledge which was constructed; for others, the knowledge built was effective. Regarding the thematic food chain, the knowledge built was showed to be effective. The results obtained show that the Didactic Module is constituted as a viable methodological strategy for the development of students in high school (secondary school). The effectiveness of the teaching-learning process is linked to other conditioning factors such as the resources used, the way in which students prefer to develop the activities and the number of students per class.

Utilization of renewable energy sources, as an approach to reduce greenhouse gas (GHG) emissions, have been globally popular in the last few decades. Among renewable energy sources, pressure retarded osmosis (PRO) has been scrutinized by scientists since the mid 70's. However, even today, the existing river-sea PRO systems can only marginally meet the generally approved criterion of 5 W/m2 power density, a threshold for an economically feasible PRO system. As an approach to increase the performance of PRO systems, multi-staging of PRO modules are investigated. A mathematical model of the scaled up PRO process is proposed with consideration for internal and external concentration polarization, reverse salt flux, and spatial variations along the membrane. A thermodynamic model is also developed with consideration for entropy generation and losses in the process. It predicts the percentile of each work loss source compared to the net work in the system. Several confi gurations of dual stage PRO system are presented and compared to single stage PRO. The comparison is based on three proposed target functions of power density (PD), specifi c energy (SE), and work per drawn freshwater (Wdrawn). Applied hydraulic pressures and flow rates of draw and feed solutions are optimized for maximizing the target functions. The results indicate that overall performance of the system could be improved by up to 8 % with a dual stage PRO in the case of SE. The system performance is not improved by depressurizing the draw solution before the second module in cases of SE and Wdrawn. The thermodynamic analysis demonstrate the contribution of each work loss and justify the reason of diminishing the net work over the losses. The effect of membrane area and membrane characteristics on the SE target function is also investigated. The distribution of membrane area in each module depends on the selected con figuration and inlet draw solution. In the dual stage systems, the SE value increases up to 14% by improving the membrane characteristics. Reducing the salt rejection coefficient (B) is the most e ective membrane characteristic in our con figurations. Replacing seawater with RO brine in draw solution results in a signifi cant improvement in SE values. / Graduate

Syftet med detta arbete är att simulera ett värmesystem i COMSOL Multiphysics, Pipe Flow Module, Non-Isothermal Pipe Flow som innehåller ekvationer och randvillkor för att modellera inkompressibel strömning och värmeöverföring i rör. Data om processen och dess komponenter har samlats in från industrin där arbetet är utfört och i vissa fall modifierats för att bättre beskrivas i programmet. Utifrån insamlad data har en modell byggts upp och två simuleringar har gjorts. En stationär för starten av systemet, den har sedan legat till grund för en dynamisk som simulerar förloppet från start till normaldrift. Tiden det tar för det aktuella fallet att nå drifttemperatur är 16 timmar. En felströmning upptäcktes samt att en av pumparna inte kommer att klara en start från 20 °C.

Road transports face increasing societal challenges with respect to emissions, safety, and traffic congestion, as well as business challenges. Truck automation, e.g. self-driving trucks may be utilized to address some of these issues. Autonomous transport vehicles may be characterized as Cyber-Physical Systems (CPS). A drawback is that CPS significantly increase technical complexity and thus introduce new challenges to system architecting. A product architecture is the interrelation between physical components and their function, i.e. their purpose. Product architectures can be categorized as being modular or integral. The main purpose of a modular architecture is to enable external variety and at the same time internal commonality. Products with a modular architecture are configured from predesigned building blocks, i.e. modules. A stable module, which is a carrier of main function(s) has standardized interfaces, is configured for company-specific reasons, which means it supports a company-specific (business) strategy. In this thesis, the present state at the heavy vehicle manufacturer Scania, concerning product architecting, modularization, product description and configuration is investigated. Moreover, a new clustering based method for product modularization that integrates product complexity and company business strategies is proposed. The method is logically verified with multiple industrial cases, where the architecture of a heavy truck driveline is used as a test bench. The driveline contains synergistic configurations of mechanical, electrical and software technologies that are constituents of an automated  and/or semi-autonomous system, i.e. the driveline may be characterized as a CPS. The architecture is analyzed both from technical complexity and business strategy point of view.  The presented research indicates that a structured methodology which supports the development of the product architecture is needed at Scania, to enable control of the increasing technical complexity in the Cyber-Physical Systems. Finally, configuration rules are identified to be highly important in order to successfully realize a modular product architecture. A drawback with this approach is that the solution space becomes hard to identify, therefore a complete and flexible product description methodology is essential. The results from the case studies indicate that clustering of a Product Architecture DSM may result in a modular architecture with significantly reduced complexity, but with clusters that contain conflicting module drivers. It is also identified that the new modularization methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, several case studies show that the proposed method can be used for analyzing and finding the explicit and/or implicit, technical as well as strategic, reasons behind the architecture of an existing product.

O presente Trabalho de Tese objetiva a concepção e o desenvolvimento de um sistema estrutural treliçado modular em madeira. Avalia o comportamento de alguns dos seus principais elementos constituintes, através de experimentos realizados em laboratório e apresenta provas com programas funcionais, tornando factível a implantação do artefato arquitetônico em terrenos difíceis com mínimo impacto ambiental. Compara de forma estimativa os custos dessa estrutura executada em madeira, concreto e aço. É permeado em sua primeira fase por um breve relato da Arquitetura Brasileira em madeira, do colonial ao contemporâneo e pela descrição sucinta das características da madeira, privilegiando sua capacidade portante e finalmente pela concepção e desenvolvimento do sistema estrutural em madeira, objeto desse trabalho, denominado Sistema estrutural treliçado modular em madeira SET 2M. Em sua segunda parte, procura-se dotar o sistema com provas de programas funcionais: três residências unifamiliares, uma multifamiliar e uma pousada. O sistema baliza-se no princípio que, para se pensar e construir uma edificação de boa qualidade com baixo custo de construção, deve-se introduzir altos níveis de racionalidade e criatividade na concepção do espaço e na sua construção. O SET 2M é caracterizado pela aplicação metodológica da sucessão e continuidade de eventos, assim como da coerência de decisões, em função de suas racionalidades de concepção e de construção, as quais objetivam organizar e prever diferentes operações em oficinas de marcenaria e serralharia em suas montagens no canteiro de obras. Essas montagens processam-se através da utilização de: 1) recursos simples, exigindo equipamentos e ferramentais disponibilizados correntemente no mercado na construção civil; 2) equipe composta por um número reduzido de pessoal; 3) prazo de execução exíguo, devido às suas características projetuais de concepção e de construção. A madeira se apresenta como um material atraente para essas concepções, pois equipara-se, em termos de custos, ao aço, material altamente empregado nos dias atuais e supera em muito o concreto protendido, material possível de execução quando pensado com as características específicas do SET 2M. Para a concepção e o desenvolvimento do SET 2M realizouse, no laboratório do LAME da FAUUSP, maquetes e protótipos de alguns dos mais significativos de seus elementos constituintes, que atestaram de forma bastante satisfatória o comportamento do sistema. A estrutura foi calculada no nível de desenvolvimento inicial, possibilitando, assim, sua estabilização geral. / The present Thesis aims the conception and the development of a wooden modulated latticed structural system. This work evaluates the behavior of some of its main constituent elements, through experiments carried through in laboratory, and presents tests with functional programs, becoming feasible the implantation of the architectural device in difficult lands with minimum environmental impact. It compares and esteems the costs of this structure executed in wood, concrete and steel. It is composed in its first phase by a brief story of the Brazilian Architecture in wood, from the colonial to the contemporary, a quick description of the characteristics of the wood, privileging its carrying capacity, and finally by the conception and development of the wooden structural system, the object of this work, called Wooden modulated latticed structural system SET 2M. In its second part, it looks to endow the system with tests in functional programs: three single residences, one familiar residence and a resort inn. The system is based in this principle: to think and to construct a building of good quality with low cost of construction, we must introduce high levels of rationality and creativity in the conception of the space and its construction. The SET 2M is characterized by a methodological application of the succession and continuity of events, as well as of the coherence of decisions, in function of its rationalities of conception and construction, which aim to organize and to foresee different operations in joineries, carpentries and locksmiths in its assemblies in the building. These assemblies are processed by the use of: 1) simple resources, demanding equipment and tools currently available in the market in the civil construction; 2) team composed by a reduced number of staff; 3) short stated period, due to its projected characteristics of conception and construction. Wood presents itself as an attractive material for these conceptions, because it compares in cost to the steel, highly used nowadays, and it surpasses the extended concrete, a possible material of execution when thought with the specific characteristics of SET 2M. For the conception and the development of the SET 2M, we built in the laboratory of the LAME of the FAUUSP mockups and prototypes of its expressive constituent elements, which certified satisfactorily the behavior of the system. The structure was calculated in the level of initial development, making possible, thus, its general stabilization.

O fator temporal é uma variável natural da maioria dos sistemas de informação, pois no mundo real os eventos ocorrem de maneira dinâmica, modicando continuamente os valores dos seus objetos no decorrer do tempo. Muitos desses sistemas precisam registrar essa modicação e atribuir os instantes de tempo em que cada informação foi válida no sistema. Este trabalho reúne as características relacionadas aos Bancos de Dados Temporais e Bancos de Dados Objeto-Relacionais. O objetivo primordial é propor uma forma de implementar alguns aspectos temporais, desenvolvendo um módulo que faça parte das características e funcionalidades internas de um SGBD. O módulo temporal contempla principalmente a parte de restrições de integridade temporal que é utilizada para manter a consistência da informação temporal armazenada. Para isso, é proposto um novo tipo de dado que melhor representa as marcas temporais dos objetos. Uma parte importante para a implementação desse projeto é a utilização de um SGBD objeto-relacional que possui algumas características orientadas a objetos que permitem a extensão de seus recursos, tornando-o capaz de gerenciar alguns aspectos temporais. O módulo temporal desenvolvido torna esses aspectos temporais transparentes para o usuário. Por conseqüência, esses usuários são capazes de utilizar os recursos temporais com maior naturalidade. / The temporal factor is a natural variable of the majority of the information systems, therefore in the real world the events occur in dynamic way, modifying continuously the values of its objects in elapsing of the time. Many of these systems need to register this modication and to attribute the instants of time where each information was valid in the system. This work congregates the characteristics related to the Temporal Databases and Object-Relational Databases. The primordial objective is to consider a form to implement some temporal aspects, developing a module that is part of the characteristics and internal functionalities of a DBMS. The temporal module mainly contemplates the part of restrictions of temporal integrity that is used to keep the consistency of the stored temporal information. For this, a new data type is proposed that better represent the objects timestamps. An important part for the implementation of this project is the use of a object-relational DBMS that has some object-oriented characteristics that allow the extension of its resources, becoming capable to manage some temporal aspects. The developed temporal module becomes these transparent temporal aspects for the user. For consequence, these users are capable to use the temporal resources more naturally.

A presente pesquisa teve por objetivo conhecer as concepções de alunos de Ensino Médio em relação à fotossíntese e a cadeia alimentar e aplicar a metodologia Módulo Didático visando favorecer o processo ensino-aprendizagem. A metodologia Módulo Didático, concebida por Delizoicov e Angotti (1990), consiste em três etapas: problematização inicial (PI), organização do conhecimento (OC) e aplicação do conhecimento (AC). A pesquisa foi desenvolvida com uma classe de 35 alunos do 1º Ano do Ensino Médio de uma escola pertencente à Rede Estadual de Ensino, localizada no município de Lorena, SP. O desenvolvimento da pesquisa ocorreu em quatro etapas: aplicação de um questionário socioeconômico e de uma avaliação diagnóstica inicial, desenvolvimento do Módulo Didático, aplicação de uma avaliação diagnóstica final ao término da aplicação da metodologia e uma nova aplicação da avaliação diagnóstica final após o período de férias escolares dos discentes. A aplicação da metodologia foi pautada no pluralismo metodológico por meio dos seguintes recursos: questões problematizadoras, leitura e análise de textos de divulgação científica, vídeos, simuladores, jogo e mapa conceitual. Dentre os resultados relacionados à análise do perfil socioeconômico dos discentes, percebeu-se que 41% possui preferência por desenvolver as atividades em um grupo pequeno, enquanto 38% tem preferência por trabalhar com outra pessoa. A análise comparativa das avaliações diagnósticas inicial, final e final após o período de férias escolares revelou tendências ao se considerar o processo ensino-aprendizagem de fotossíntese e de cadeia alimentar. Para a temática fotossíntese, alguns assuntos necessitam ser abordados a partir de recursos distintos dos utilizados para o desenvolvimento da pesquisa, uma vez que não houve efetividade no conhecimento construído; para outros, o conhecimento construído se mostrou efetivo. Em relação à temática cadeia alimentar, o conhecimento construído apresentou efetividade. Os resultados obtidos, portanto, revelaram que o Módulo Didático se constitui como uma estratégia metodológica viável para desenvolvimento com alunos de Ensino Médio. A efetividade do processo ensinoaprendizagem está atrelada a outros fatores condicionantes, tais como os recursos utilizados, o modo pelo qual os discentes preferem desenvolver as atividades bem como o número de alunos por classe. / The following research has the aim to discover the views of secondary school (high school) students in relation to photosynthesis and the food chains, and the application of the Didactic Module methodology to facilitate the teaching-learning process. The Didactic Module methodology, designed by Delizoicov and Angotti (1990), consists of three stages: initial questioning, organization of knowledge, and the application of knowledge. The research was conducted with a class of 35 students from the 1st year of a secondary school which belonged to a network of public schools, located in the city of Lorena, SP. The development of the research took place in four steps: the application of a socioeconomic questionnaire and an initial diagnostic evaluation, the development of the Didactic module, the application of a final diagnostic evaluation at the end of the methodology application and a new application of the final diagnostic evaluation after a period of the student\'s school holidays. The methodology was based on methodological pluralism through the following resources: questions which cause problems, the reading and the analysis of scientific texts, videos, simulators, games and concept map. Among the results related to the analysis of the socioeconomic profile of students, it was noticed that 41% have preference for developing activities in a small group, while 38% have a preference for working with someone else. The comparative analysis of the diagnostic evaluations from the beginning, middle and end of the school holiday period revealed trends when considering the teaching-learning process of photosynthesis and the food chain. For the theme photosynthesis, some issues need to be addressed from different resources used for the development of the researches, since there was no effectiveness in the knowledge which was constructed; for others, the knowledge built was effective. Regarding the thematic food chain, the knowledge built was showed to be effective. The results obtained show that the Didactic Module is constituted as a viable methodological strategy for the development of students in high school (secondary school). The effectiveness of the teaching-learning process is linked to other conditioning factors such as the resources used, the way in which students prefer to develop the activities and the number of students per class.

Submitted by admin tede (tede@pucgoias.edu.br) on 2018-08-23T10:49:49Z No. of bitstreams: 1 FELIPE RABELO RODRIGUES ALVES.pdf: 2420637 bytes, checksum: 29b86a56944a6b8d8dd2f04052fb7420 (MD5) / Made available in DSpace on 2018-08-23T10:49:49Z (GMT). No. of bitstreams: 1 FELIPE RABELO RODRIGUES ALVES.pdf: 2420637 bytes, checksum: 29b86a56944a6b8d8dd2f04052fb7420 (MD5) Previous issue date: 2018-06-06 / The dependence on nonrenewable sources and concern about high levels of pollutant emissions encourage the use of systems that are derived from renewable resources. In this way, photovoltaic systems are seen as promising because they depend on a clean and abundant source, especially in areas of tropical climate, the solar radiation. However, the accumulation of soiling on the surfaces of photovoltaic modules is one of the main environmental factors that cause of the loss of efficiency of these systems, together with irradiance, temperature and shading. In this sense, the present work seeks to verify the soiling effects on the efficiency of photovoltaic modules, through data collection, measurement of specific parameters, statistical analysis and comparisons of scenarios of dirty and clean modules. For the verification and quantification of soiling interference in the efficiency of photovoltaic modules, the electrical and environmental parameters capable of characterizing them are obtained: Isc - Short circuit current (A); Voc - Open circuit voltage (V); G - Solar irradiance (W/m²); T - Module temperature (°C). From the results it can be observed that the intensity of the solar radiation has greater influence on the current of the module, while the temperature directly affects the voltage. This work showed that, in the universe studied, soiling has reduced the power generation efficiency of modules by 3,2% for accumulated soiling in periods of 45 days, and by 18% for accumulated soiling in a longer period of 3,5 years. The characterization of the soiling showed that in addition to mineral particles, there is also organic matter derived from biofilms, which makes it difficult to clean the modules by natural methods (rains and winds). Based on the bibliography and the tests realized, it is estimated that the periodicity of the hygiene should not exceed 60 days, with that, the effects of the soiling are reduced significantly. / A dependência por fontes não renováveis e a preocupação com os elevados níveis de emissões de poluentes estimulam o uso de sistemas que são provenientes de recursos renováveis. Com isso, são vistos como promissores os sistemas fotovoltaicos, por dependerem de uma fonte limpa e abundante, em especial em áreas de clima tropical, a radiação solar. Porém, o acúmulo de sujeira nas superfícies de módulos fotovoltaicos é um dos principais fatores ambientais que causam perda de eficiência desses sistemas, juntamente com irradiância, temperatura e sombreamento. Neste sentido, o presente trabalho busca verificar os efeitos da sujidade na eficiência dos módulos fotovoltaicos, por meio de coletas de dados, medições de parâmetros específicos, análise estatística e comparações de cenários de módulos sujos e limpos. Para a comprovação e quantificação da interferência da sujidade na eficiência de módulos fotovoltaicos são obtidos os parâmetros elétricos e ambientais capazes de caracterizá-los, são eles: Isc - Corrente de curto-circuito (A); Voc - Tensão de circuito aberto (V); G - Irradiância solar (W/m²); T - Temperatura do módulo (°C). A partir dos resultados pode-se observar que a intensidade da radiação solar tem maior influência sobre a corrente do módulo, enquanto que a temperatura afeta diretamente a tensão. Este trabalho comprovou que, no universo estudado, a sujidade diminuiu a eficiência dos módulos em até 3,2% para sujeira acumulada em períodos de 45 dias, e em até 18% para sujidades acumuladas por um período mais longo, de 3,5 anos. A caracterização da sujidade demonstrou que além de partículas minerais, há também matéria orgânica derivada de biofilmes, que dificulta a limpeza dos módulos pelos métodos naturais (chuvas e ventos). Com base na bibliografia e nos ensaios realizados, estima-se que a periodicidade de higienização não deva exceder 60 dias, assim os efeitos da sujidade são reduzidos significativamente.