Thermal stresses can arise in glass used in architectonic realisations in buildings as a result of solar irradiation:  that is, sunlight.  The magnitude of these thermal stresses depends on the temperature conditions in the glass in terms of the temperature differences between warm and cold areas.  The work described here has verified the existence and distribution of thermal stresses in glass, both theoretically and experimentally, in a load-bearing element made of glass and wood, when exposed to incident solar radiation and various degrees of shading.  The finite element method was used in order to simulate the temperature distribution in the glass, together with the resulting associated thermal stresses.  Parts of these model results were then compared with results and data from experimental investigations in a solar simulator.  The experimental trials were carried out on a plain glass sheet and on a wood-framed glass sheet.  This frame assembly saw the glass fitted in a wooden frame such that its edge was flush with the edges of the frame and therefore freely exposed to the surroundings.  Two different grades of glass were analysed in the theoretical modelling and used in the experimental solar exposure:  a clear glass, with a low absorption coefficient, and a tinted glass having a relatively high absorption coefficient.  The experimental part of the work included two different finishes to the glass edge:  as-cut, with no further attention, and cut and smoothed.  The results from the finite element method calculations agree relatively well with the experimental results.  When simulating the temperature values and distributions, the value of the coefficient of heat transfer is an important factor in determining the results.  The coefficient can be given either a constant value, taken from a standard, or a calculated value that varies depending on the surface temperature and ambient temperature at every instant.  For the clear glass with a low coefficient of absorption, the calculated temperatures did not differ significantly depending on which method had been used to provide a value for the coefficient of heat transfer.  However, for the glass with a high coefficient of absorption, and when exposed to high solar intensity, a calculated value of coefficient of heat transfer should be used in order to arrive at relevant values of surface temperatures and stresses.  Thermal tensile stresses have more effect on the total stress level than have stresses arising from typical in-service vertical loads.

Les réglementations thermiques successives poussent les bâtiments à consommer de moins en moins d’énergie. Les performances énergétiques accrues des bâtiments passent notamment par une bonne utilisation du rayonnement solaire en tant que source de chaleur (en évitant les surchauffes), de lumière ou d’énergie pour les panneaux solaires. Si les principes de conception permettant de bien profiter de ce rayonnement sont connus à l’échelle d’un bâtiment, les travaux portant sur la recherche des bonnes configurations de bâtiments à l’échelle du quartier sont en plein développement. A mesure que les logiciels de simulation du rayonnement solaire ou des besoins énergétiques s’améliorent et prennent mieux en compte la dimension urbaine, de nombreuses études sur la ville voient le jour. Les outils d’optimisation, par ailleurs largement utilisés dans le cadre du dimensionnement des systèmes du bâtiment et des matériaux composant son enveloppe ont cependant été peu utilisés dans l’étude des formes urbaines. Ceux-Ci présentant cependant l’avantage de pouvoir explorer de grands espaces de paramètres de manière intelligent. Ce travail de thèse a porté sur l’optimisation de formes urbaines par rapport au potentiel solaire. Dans ce cadre, un outil reposant sur un algorithme évolutionnaire a été mis en place. Celui-Ci permet de trouver le positionnement optimal de volumes correspondant à des bâtiments soumis au rayonnement solaire. Pour cela, différents types de paramètres sont associés aux bâtiments (hauteur, orientation, position), tandis que le contexte urbain du quartier peut être considéré de plusieurs manières : dégagé, fixe (quartier pré-Existant), ou périodique. Les essais d’optimisation effectués cherchent à maximiser l’exposition au soleil pour des latitudes comprises entre 40° et 60°N, différentes périodes de temps et densité bâties. Une extension est de plus réalisée pour étudier les quartiers minimisant les besoins en énergie pour le chauffage. Dans l’ensemble des cas, les résultats montrent qu’il existe de nombreuses configurations quasi-Optimales dont l’analyse permet d’identifier des comportements généraux du quartier en fonction du critère d’optimisation. Tous ces résultats sont encourageants et ouvrent des perspectives pour de futurs travaux. / The recent thermal regulations lead to more efficient buildings. Their design includes a good use of sunlight as a heat source (while avoiding overheating), light or energy for solar panels. If the principles of design to make the most of this radiation are known at the building scale, studies are still under development at the district level. As the software tools for the simulation of solar radiation or energy needs improve and better reflect the urban dimension, numerous studies at the district scale emerge. The optimization methods, although widely used to size the building systems and materials, are not common in the study of urban forms. However, these have the advantage of being able to explore large parameter spaces. This thesis focuses on the urban form optimization with respect to the solar potential. For this purpose, a tool based on an evolutionary algorithm is implemented. Its goal is to find the optimal positioning of volumes corresponding to buildings subjected to sunlight. Different types of parameters are associated with buildings (height, orientation, position), while the urban context can be considered in several ways : open, fixed (pre-Existing neighborhood), or periodic. Optimization tests seek to maximize exposure to the sun for latitudes between 40° and 60°N, different time periods and built densities. An extension is further performed to investigate neighborhoods minimizing energy requirements for heating. In all cases, the results show that there are many near-Optimal configurations that can be analyzed to identify general features of the good neighborhoods for each optimization criterion. All these results are inspiring and open perspectives for future works.

Orientador: Paulo Ademar Martins Leal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-24T08:15:40Z (GMT). No. of bitstreams: 1 Ferrari_DiegoLuis_M.pdf: 2952607 bytes, checksum: fdc4b751b2836dc065f70c5e44f8f67b (MD5) Previous issue date: 2013 / Resumo: Em regiões tropicais, ambientes protegidos com filmes de polietileno de baixa densidade (PEBD) podem atingir facilmente temperaturas acima da faixa ótima recomendada para as culturas hortícolas como o tomateiro. Quando a ventilação natural não é capaz de reduzir a carga térmica do ambiente, outros níveis tecnológicos de controle microclimático podem ser empregados, como o sombreamento por meio de telas termorrefletoras que visam restringir o aumento excessivo da temperatura do ar por meio da reflexão de parte da radiação solar. No entanto, o uso da técnica deve ser feito com cautela e manejo, pois a redução excessiva da radiação solar pode ter reflexos negativos sobre o crescimento, desenvolvimento e produção do tomateiro. O presente trabalho teve como objetivo comparar os efeitos de diferentes coberturas (PEBD e PEDB associado à tela temorrefletora empregada somente em dias de céu claro) sobre os microclimas dos respectivos ambientes protegidos e o efeito destes sobre a qualidade da produção e o crescimento de plantas de tomateiros dos grupos minitomate, italiano e caqui ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: In tropical climates, air temperature inside greenhouses covered with low density polyethylene (LDPE) can exceed the optimum range recommended for horticultural crops like tomato. In the cases which natural ventilation is not capable of reducing the greenhouse thermal load, other kind of microclimatic control technology like shading with thermal screen may be employed, which restrain the excessive increase of air temperature by reflecting part of solar radiation. However, the use of this technique must be done carefully with appropriate handling since excessive reduction of solar radiation may lead negative effects on growth, development and yield of tomatoes. The objective of this study was to compare the effect of two different coverings (LDPE and LDPE with thermal screen employed only in clear sky days) on the microclimates of greenhouses and their effects on vegetative growth and fruit quality of Minitomato, Italian and Kaki tomato groups ... Note: The complete abstract is available with the full electronic document / Mestrado / Construções Rurais e Ambiencia / Mestre em Engenharia Agrícola

O estudo da penetração da radiação solar no meio aquático foi desenvolvido em quatro partes. Na primeira delas, voltada para a atenuação da radiação solar na coluna d’água, foram discutidos fatores de interferência e suas inter-relações. Neste sentido, foi feita uma comparação da penetração da radiação solar em ecossistemas continentais naturais e artificiais, analisando as diferenças e similaridades. O estudo comparativo da atenuação da radiação solar subaquática em toda extensão de reservatórios constituiu a segunda parte deste trabalho. A comparação foi feita entre reservatórios que apresentam proximidades de localização, mas com diferenças marcantes nos usos e ocupações nas regiões em que os mesmos estão inseridos. Na terceira parte foram apresentados dois recursos de grande utilização na obtenção das respostas imediatas do ambiente aquático, do ponto de vista óptico, diante dos impactos sofridos. O primeiro recurso foi a determinação do espectrograma da radiação solar, indicando a atenuação da radiação solar subaquática na faixa fotossinteticamente ativa (400 nm - 700 nm). O outro recurso foi a obtenção do espectro de absorção da água superficial, que permitiu o estabelecimento do “Índice de Absorção Espectral da Água”, I.A.E.A., que facilmente possibilita a detecção de fontes pontuais de poluição e contaminação. Como quarta e última parte foi proposto o desenvolvimento de um aparelho a partir da reconstrução do hidrofotômetro (Modelo Nº 268 WA 310 GM MFG & Instrument Corp. Bronx. N.Y. 10 451), onde foi introduzido e adaptado o detector fotocondutivo (PIN - 250DP) em substituição às fotocélulas anteriormente danificadas. Durante o trabalho de campo, este aparelho foi testado e foi feita a comparação com os obtidos do Quanta-meter LI-COR (LI - 185A) também utilizado neste trabalho. / The study of solar radiation penetration in aquatic environment was developed in four parts. The first one, directed to solar radiation attenuation in the water column, interference factors and their inter-relations were discussed. In this sense, a penetration comparison of the solar radiation in natural and artificial continental ecosystems was carried out, analyzing differences and similarities. The second part of this work consisted of a comparative study of underwater solar radiation in the entire reservoir. The comparison was done between reservoirs that are near to one another, but with marked differences in use and occupation within the regions where they are located. In the third part, two resources of great utilization in obtaining immediate response from the aquatic environment, from an optical point of view of the impacts experienced, were presented. The first resort was the spectrogram determination of solar radiation, which indicated the underwater solar radiation attenuation in the active photosynthetic range (400 nm - 700 nm). The other resort was the superficial water absorption spectrum, which allowed establishing the “Water Spectral Absorption Index”, I.A.E.A. that easily makes possible detection of accurate sources of pollution and contamination. The fourth and last part proposed to develop an apparatus from the construction of an underwater hydrophotometer (Model 268 WA 310 GM MFG & Instrument Corp. Bronx N.Y. 10451), where the photoconductor detector was adapted and introduced (PIN - 250DP) substituting the previously damaged photocells. During field work, this apparatus was tested and comparison was performed with data obtained from Quanta-meter LI-COR (LI - 185A), also used in this work.

Orientador: Alexandre Dal Pai / Resumo: O objetivo do trabalho foi o desenvolvimento de um programa computacional para processamento e gerenciamento de dados de brilho solar registrados por heliógrafos, monitorados em estações meteorológicas. O código-fonte do programa foi elaborado a partir da linguagem de programação Java EE 7 (Java Enterprise Edition), baseada em aplicações para internet. O armazenamento e gerenciamento das informações foi realizado pelo Sistema de Gerenciamento de Banco de Dados (SGBD) MySQL 5.7. Por meio de técnicas de processamento digital de imagens, incorporadas ao programa, dados de brilho solar foram contabilizados de maneira automatizada e padronizada, possibilitando a formação de uma base de dados na partição de tempo diária, comum em estações meteorológicas, e uma base de dados horária, o que representa novidade devido à complexidade do processo de coleta realizado manualmente. Para ajustes e validação do programa, utilizou-se um conjunto de dados de brilho solar no período de 01/01/2015 a 31/12/2015, fornecidos pela Estação Meteorológica Lageado da Faculdade de Ciências Agronômicas (UNESP) de Botucatu - SP. Comparações entre coletas realizadas pelo programa computacional e coletas realizadas de maneira manual apresentaram valores anuais de MBE de 0,393 horas (rMBE = 6,301 %), RMSE de 2,148 horas (rRMSE = 34,432 %) e R de 0,841. Em relação ao tempo de coleta, o programa computacional despendeu, em média, 41,825 segundos a menos que o método manual. Estimativas de irradiação solar globa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was the development of a computer program for processing and management of sunshine data recorded by heliographers, monitored in meteorological stations. The source code for the program is based on the Java EE 7 (Java Enterprise Edition) programming language, based on internet applications. The information was stored and managed by the MySQL 5.7 Database Management System (DBMS). Through digital image processing techniques, incorporated into the program, sunshine data were accounted for an automated and standardized method, enabling the formation of a daily database, common in meteorological stations, and an hourly database. This is new due to the complexity of the manual collection process. To adjust the PDI techniques and validation of the computer program, a paper-based sunshine data set was used from 01/01/2015 to 12/31/2015, provided by the Lageado Meteorological Station of the School of Agricultural Sciences (UNESP) Botucatu - SP. Comparisons between collections performed by the computer program and collections performed manually presented annual MBE values of 0,393 hours (rMBE = 6,301 %), RMSE of 2,148 hours (rRMSE = 34,432 %) and R is 0,841. Regarding the collection time, the computer program spent, on average, 41. 825 seconds less compared to the manual collection method. Estimates of global solar irradiation generated with sunshine data obtained by the computer program showed better results in relation to estimates with sunshine data coll... (Complete abstract click electronic access below) / Mestre

The diploma thesis contains by renovation of the family House on the “nearly zero-energy consumption building”, the proposal is for a variety of energy measures to achieve this status.

Orientador: João Francisco Escobedo / Resumo: No presente trabalho é descrito o estudo comparativo de métodos de estimativas da irradiação solar global (HG) diária através do modelo de Hargreaves-Samani (H-S) HG/HO = a ΔT0,5 e duas técnicas de Aprendizado de Máquina (AM), Máquinas de Vetores de Suporte (MVS) e Redes Neurais Artificiais (RNA). A base de dados utilizada foi obtida em 11 cidades do estado de São Paulo de diferentes classificações climáticas no período de 2013-2017. Por meio de regressão entre a transmissividade atmosférica (HG/HO) e raiz quadrada da diferença de temperatura (ΔT0,5). O modelo estatístico H-S foi calibrado e determinado para os valores da constante (a) e equações que permitem estimar HG com baixos coeficientes de determinação para duas condições:11 cidades individualmente e total. Os modelos de H–S foram validados por meio de correlações entre os valores estimados e medidos através dos indicadores de correlação (r) e rRMSE cujos valores indicaram que os modelos podem estimar HG com razoável precisão e exatidão. As técnicas computacionais, MVS e RNA, foram treinadas com 70% dos dados nas mesmas variáveis usadas no modelo de H-S, e posteriormente foram treinadas com entradas de mais 4 variáveis meteorológicas totalizando 5 combinações. Os treinos foram validados usando uma base de dados independente de 30% da base. Os indicativos estatísticos (r) das correlações mostraram que o modelo H-S pode estimar HG com baixos coeficientes de determinação. Os indicativos estatísticos rMBE, MBE, rRMSE, RMSE... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work describes the comparative study of methods for estimating daily global solar irradiation (HG) using the Hargreaves-Samani (H-S) model HG / HO = a ΔT0.5 and two Machine Learning techniques (AM), Support Vectors Machines (MVS) and Artificial Neural Networks (ANN). The database used was obtained in 11 cities by the state of São Paulo from different climatic classifications between period 2013-2017. Through regression between differents atmospheric transmissivity (HG / HO) and square root of the temperature difference (ΔT0.5). The H-S statistical model was calibrated and determined for the values of constant (a) and equations that allow estimating HG with low determination coefficients for two conditions:11 cities individually and total. The H–S models were validated by correlations between the estimated and measured values using the correlation indicators (r) and rRMSE, whose values indicated that the models can estimate HG with reasonable precision and exactitude. The computational techniques, MVS and RNA, were trained with 70% of the data in the same variables used in the H-S model, later they were trained with inputs of 4 more meteorological totalling 5 combinations. The training was validated using an independent database of 30%. The statistical indications of the correlations showed that the H-S model can estimate HG with low determination coefficients. The statistical indications rMBE, MBE, rRMSE, RMSE indicate that the H-S model can be used to estimate HG with r... (Complete abstract click electronic access below) / Mestre

This study aims to investigate opportunities to make commercial buildings in Pretoria, South Africa, more energy efficient, which is made by examining prerequisites in South Africa. To achieve this objective, barriers and measures to decrease cooling demand are investigated by a qualitative approach and a roof heat transfer model is developed to get a deeper understanding of the ceiling temperature distribution. The heat transfer model is simulated in MATLAB and is further validated by conducting a two-case scenario sensitivity analysis and by comparing the results to previous research. The results show that there is a great correlation between the Global Horizontal Irradiance [GHI] and the interior ceiling temperature and a higher GHI contributes to a higher ceiling temperature. The hot climate and the long summer period in South Africa indicate that there is a great demand for cooling during a year. Regarding barriers, the socioeconomic aspects in the country and the low electricity prices may contribute to less willingness to adapt to an environmentally friendly behaviour. As some technologies are still perceived as expensive, this may also provide a lower willingness to make changes regarding choices that contribute to a lower cooling demand and thus, energy consumption. Finally, it is concluded that there are several measures that can be applied to decrease the cooling demand, such as constructional changes or enhancement of the heating, ventilation and air-conditioning [HVAC] operation.

No description available.

<p> Reflection and heating coefficients were measured during the 3 month summer season at Simcoe, southern Ontario. Contrasting agricultural surfaces and atmospheric conditions were used to analyse their effect on the reflection and heating coefficients. The results confirm the postulate of Montieth (1959a) that <alpha> is close to 0.25 for many vegetated surfaces. <beta> values were positive and there was a tendency for <beta> to approximate 0.22 for many of the vegetated surfaces. Finally it was shown that the radiation balance equation for Simcoe can be generalized into a linear function of solar radiation using the same constants that are applicable to many areas in the world. </p> / Thesis / Master of Arts (MA)