Electrospinning has been recognized as an efficient technique for the fabrication of polymer fibers. These electrospun fibers have many applications across a broad range of industries. In this research, optical transparent composites were successfully fabricated by embedding polyacrylonitrile (PAN) hollow nanofibers into poly (methyl methacrylate) (PMMA) matrix. The hollow PAN nanofibers were prepared by coaxial electrospinning. The PAN was used as the shell solution, and the mineral oil was used as the core solution. The resulting fibers were then etched with octane to remove the mineral oil from the core. The hollow PAN fibers were then homogeneously distributed in PMMA resins to fabricate the composite. The morphology, transmittance and mechanical properties of the PAN/PMMA composite were then characterized with an ESEM, TEM, tensile testing machine, UV-vis spectrometer and KD2 Pro Decagon device. The results indicated that the hollow nanofibers have relatively uniform size with one-dimensional texture at the walls. The embedded PAN hollow nanofibers significantly enhanced the tensile stress and the Young's modulus of the composite (increased by 58.3% and 50.4%, respectively), while having little influence on the light transmittance of the composite. The KD2 Pro device indicated that the thermal conductivity of the PMMA was marginally greater than the PAN/PMMA composite by 2%. This novel transparent composite could be used for transparent armor protection, window panes in vehicles and buildings, and airplane windshield etc.

The use of sunlight has always been a major goal in the design and operation of commercial buildings to minimize electrical consumption of artificial lighting systems. Glazing systems designed to allow optimal visible light transmission also allow significant unwanted direct solar heat gain caused by infrared light. Conversely, glazing systems that are designed to reflect unwanted direct solar heat gain significantly reduce the transmittance of visible light through windows. The goal of this research was to characterize the performance of water as gap-fill for double-glazing units in eliminating the compromises that exist in current glazing systems with respect to light and heat transmittance. An in situ test approach and computer simulations were conducted to measure the performance of water-filled glazing units against air-filled glazing units. The thermal transmittance and solar heat gain coefficient values obtained from both the field experiments and computer simulations, glazing units with air-fill proved better than the glazing units with non-flowing water-fill. However, the high convective coefficient and the high thermal mass of the water can be used to its advantage when it is allowed to flow at peak temperatures, thus, maintaining lower temperature swings indoor. This can lead to a reduction of about 50-70% direct solar heat and still maintain high visibility.

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Neste trabalho é realizada a avaliação do desempenho solar e luminoso de chapas metálicas com diferentes padrões de perfurações empregados para proteção solar na envoltória das edificações. Foram ensaiadas experimentalmente as transmitâncias solar e luminosa em diversos ângulos de incidência de chapas metálicas, chapas expandidas e telhas metálicas, com ou sem pintura, planas ou com conformação espacial. Avaliou-se a relação entre a transmitância e % de perfuração da amostra para incidência da radiação em variadas alturas e azimutes solares, comparou-se o comportamento solar e luminoso de cada amostra e entre amostras com características semelhantes. As normas ASTM E972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight e ASTM E1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight foram adotadas para medições de campo das amostras. Os resultados mostram que, para todas as amostras, as transmitâncias solar (TS) e luminosa (TL) na perpendicular se assemelham a % de perfuração da amostra; para ângulos diferentes da normal há uma redução conforme a altura solar diminui e que quanto maior for o furo em relação à espessura, menor será a redução. TS/TL decresce conforme a altura solar diminui, exceto para as telhas. Em relação à variação de azimute, para chapas perfuradas sem acabamento ou pintadas, os valores de TS e TL se mantêm praticamente iguais, enquanto que para chapas expandidas e telhas os valores variam. Para as amostras pintadas, TS e TL das amostras com cores claras são maiores do que das amostras com cores médias que por sua vez são maiores do que as amostras com cores escuras. A partir destes resultados e da elaboração da ficha de aplicação dos resultados para variados ângulos, no âmbito do projeto de arquitetura, contribui-se para o emprego apropriado deste tipo de material, além de complementar informações técnicas pouco disponíveis no mercado. Além disso, os dados medidos em campo podem servir de validação para modelagem computacional para uma variação maior de ângulos, e na avaliação de ambientes projetados ou construídos, os dados coletados, em especial os ângulos diferentes da incidência normal, podem ser usados em simulação energética ao longo do ano. / This research focuses on the evaluation of solar and optical performance of metal sheets with different patterns of perforations used as shading devices in the building\'s envelope. Solar and light transmittance were experimentally tested at normal and off-normal incident angles of samples of perforated metal sheet, expanded metal sheets and perforated tile, with or without painting, flat or volumetric shape. The relationship between % perforation of sample and transmittance for off normal angle incidence (height and azimuth) was evaluated. Solar and optical results were correlated for each sample. Samples with similar characteristics such as perforation, painting, hole dimension were compared. ASTM E 972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight and ASTM E 1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight were adopted for field measurements of the samples. The results show that for all samples, the solar transmittance (TS) and light (TL) perpendicular to the sample is similar to % perforation; for off normal angles there is a reduction as the solar altitude decreases and that the higher the hole relative to thickness, the smaller the reduction. TS / TL decreases as solar height decreases, except for the tiles. Regarding the change in azimuth for perforated sheets with or without painting, the values of TL and TS remains practically the same, whereas for expanded metal and tiles values vary. For the painted samples, TS and TL bright color of the samples are higher than the intermediate color samples which are in turn higher than the samples of dark colors. From the results achieved and with the development of the application table to diferente incident angles, within the architecture field, these results provide information for the appropriate use of such material, plus some additional technical information available in the market. Furthermore, the data measured in the field can serve as validation for computational modeling to a wider range of angles, and also it could be used in buildings\' energy simulations.

Neste trabalho é realizada a avaliação do desempenho solar e luminoso de chapas metálicas com diferentes padrões de perfurações empregados para proteção solar na envoltória das edificações. Foram ensaiadas experimentalmente as transmitâncias solar e luminosa em diversos ângulos de incidência de chapas metálicas, chapas expandidas e telhas metálicas, com ou sem pintura, planas ou com conformação espacial. Avaliou-se a relação entre a transmitância e % de perfuração da amostra para incidência da radiação em variadas alturas e azimutes solares, comparou-se o comportamento solar e luminoso de cada amostra e entre amostras com características semelhantes. As normas ASTM E972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight e ASTM E1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight foram adotadas para medições de campo das amostras. Os resultados mostram que, para todas as amostras, as transmitâncias solar (TS) e luminosa (TL) na perpendicular se assemelham a % de perfuração da amostra; para ângulos diferentes da normal há uma redução conforme a altura solar diminui e que quanto maior for o furo em relação à espessura, menor será a redução. TS/TL decresce conforme a altura solar diminui, exceto para as telhas. Em relação à variação de azimute, para chapas perfuradas sem acabamento ou pintadas, os valores de TS e TL se mantêm praticamente iguais, enquanto que para chapas expandidas e telhas os valores variam. Para as amostras pintadas, TS e TL das amostras com cores claras são maiores do que das amostras com cores médias que por sua vez são maiores do que as amostras com cores escuras. A partir destes resultados e da elaboração da ficha de aplicação dos resultados para variados ângulos, no âmbito do projeto de arquitetura, contribui-se para o emprego apropriado deste tipo de material, além de complementar informações técnicas pouco disponíveis no mercado. Além disso, os dados medidos em campo podem servir de validação para modelagem computacional para uma variação maior de ângulos, e na avaliação de ambientes projetados ou construídos, os dados coletados, em especial os ângulos diferentes da incidência normal, podem ser usados em simulação energética ao longo do ano. / This research focuses on the evaluation of solar and optical performance of metal sheets with different patterns of perforations used as shading devices in the building\'s envelope. Solar and light transmittance were experimentally tested at normal and off-normal incident angles of samples of perforated metal sheet, expanded metal sheets and perforated tile, with or without painting, flat or volumetric shape. The relationship between % perforation of sample and transmittance for off normal angle incidence (height and azimuth) was evaluated. Solar and optical results were correlated for each sample. Samples with similar characteristics such as perforation, painting, hole dimension were compared. ASTM E 972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight and ASTM E 1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight were adopted for field measurements of the samples. The results show that for all samples, the solar transmittance (TS) and light (TL) perpendicular to the sample is similar to % perforation; for off normal angles there is a reduction as the solar altitude decreases and that the higher the hole relative to thickness, the smaller the reduction. TS / TL decreases as solar height decreases, except for the tiles. Regarding the change in azimuth for perforated sheets with or without painting, the values of TL and TS remains practically the same, whereas for expanded metal and tiles values vary. For the painted samples, TS and TL bright color of the samples are higher than the intermediate color samples which are in turn higher than the samples of dark colors. From the results achieved and with the development of the application table to diferente incident angles, within the architecture field, these results provide information for the appropriate use of such material, plus some additional technical information available in the market. Furthermore, the data measured in the field can serve as validation for computational modeling to a wider range of angles, and also it could be used in buildings\' energy simulations.