Bi-directional Photogoniometer for the Assessment of the Luminous Properties of Fenestration Systems

Most energy saving applications of advanced fenestration systems (solar blinds, novel types of glazing and daylight redirecting devices) require a precise knowledge of their directional light transmission features. These photometric properties can be described by a Bi-directional Transmission Distribution Function (BTDF) whose experimental assessment requires appropriate equipment. A novel bi-directional transmission photogoniometer, based on digital imaging techniques, was designed and set up for that purpose. The apparatus takes advantage of a modern video image capturing device (CCD digital camera) as well as of powerful image analysis software (pattern recognition) to considerably reduce the scanning time of a BTDF measurement, in comparison to existing devices that use a conventional approach (mobile photometer). A detailed calibration and validation procedure was used to obtain optimal experimental accuracy for the device during the assessment of BTDF data. It included a spectral, a photometric and a geometrical calibration of the digital video system, as well as several additional corrections, leading to an overall relative accuracy better than 11% for BTDF data. A special effort was made to improve the user-friendliness of BTDF measurement by facilitating the data acquisition and treatment (definition of a data acquisition and electronic data format) and by offering different possibilities of BTDF visualisation (hemispherical representation, axonometric view of photometric solids, C-planes). Overall, the photometric equipment was used to assess the BTDFs of more than 20 novel fenestration products of the industrial partner of the project (Baumann-Hüppe Storen AG). The experimental data produced was successfully used by the company to optimise the visual and energy saving performance of their products, which confirms the adequacy of the novel bi-directional photogoniometer for practical building applications

Sol-gel deposition of nanostructured low refractive index materials on solar collector glazing

Nanoporous SiO2 and nanocomposite MgF2:SiO2 coatings have been deposited by sol gel dip-coating in a particle-free atmosphere. The refractive index of the prepared nanostructured thin films is determined from spectrophotometric data. In both cases, significantly lower values than for compact SiO2 have been achieved. Highly transparent samples have been produced in a single dip-coating step followed by simple thermal annealing in air. Broad spectral transmittance maxima are observed exceeding values of 98.5% (nanoporous SiO2) and 99.5% (quaternary Mg:F:Si:O films). MgF2:SiO2 nanocomposite thin films can be expected to exhibit a higher aging stability than porous SiO2 films with respect to pore-filling by hydrocarbons and are therefore a promising alternative as well for single-layered anti reflection coatings as for multilayered coulored coatings on solar collector glazing

Mitochondrial Pathway Mediates the Antileukemic Effects of Hemidesmus Indicus, a Promising Botanical Drug

Although cancers are characterized by the deregulation of multiple signalling pathways, most current anticancer therapies involve the modulation of a single target. Because of the enormous biological diversity of cancer, strategic combination of agents targeted against the most critical of those alterations is needed. Due to their complex nature, plant products interact with numerous targets and influence several biochemical and molecular cascades. The interest in further development of botanical drugs has been increasing steadily and the FDA recently approved the first new botanical prescription drug. The present study is designed to explore the potential antileukemic properties of Hemidesmus indicus with a view to contributing to further development of botanical drugs. Hemidesmus was submitted to an extensive in vitro preclinical evaluation.A variety of cellular assays and flow cytometry, as well as a phytochemical screening, were performed on different leukemic cell lines. We have demonstrated that Hemidesmus modulated many components of intracellular signaling pathways involved in cell viability and proliferation and altered the protein expression, eventually leading to tumor cell death, mediated by a loss of mitochondrial transmembrane potential and increased Bax/Bcl-2 ratio. ADP, adenine nucleotide translocator and mitochondrial permeability transition pore inhibitors did not reverse Hemidesmus-induced mitochondrial depolarization. Hemidesmus induced a significant [Ca(2+)](i) raise through the mobilization of intracellular Ca(2+) stores. Moreover, Hemidesmus significantly enhanced the antitumor activity of three commonly used chemotherapeutic drugs (methotrexate, 6-thioguanine, cytarabine). A clinically relevant observation is that its cytotoxic activity was also recorded in primary cells from acute myeloid leukemic patients.These results indicate the molecular basis of the antileukemic effects of Hemidesmus and identify the mitochondrial pathways and [Ca(2+)](i) as crucial actors in its anticancer activity. On these bases, we conclude that Hemidesmus can represent a valuable tool in the anticancer pharmacology, and should be considered for further investigations

Comparative antioxidant and bioavailability studies of Vitamin C in Phyllanthus emblica Linn. and its combinations with Piper nigrum Linn. and Zingiber officinale Roscoe

ABSTRACT Phyllanthus emblica Linn. (amla) is used in Ayurveda, the ancient Indian system of medicine and its major constituent is vitamin C which has effective free radical scavenging property. The purpose of this study was to evaluate the in vitro antioxidant activity and the bioavailability profile of vitamin C in amla and its combinations with piperine and ginger in comparison to synthetic vitamin C using New Zealand rabbits. In vitro antioxidant activity studies of synthetic vitamin C, amla, amla with piperine and amla with ginger were carried out using different models such as 2,2-Diphenyl-1-picrylhydrazyl, Nitric Oxide, Hydrogen peroxide scavenging methods, Total reductive capability and Oxygen Radical Absorbance Capacity estimation. The study results showed that synthetic vitamin C, amla, amla with piperine and amla with ginger possess significant in vitro antioxidant activity. For bioavailability studies, synthetic vitamin C, amla, amla with piperine and amla with ginger 100 mg/kg, were administered orally and the serum samples were analyzed by HPLC at 0, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours. Bioavailability studies revealed that amla with piperine combination has higher concentration of vitamin C when compared to synthetic vitamin C. This is probably due to presence of piperine, which is a bioavailability enhancer. The present study supports the fact that amla with piperine combination can be an alternative to synthetic vitamin C

Multi-criteria analysis for the integrated performance assessment of complex fenestration systems

Complex fenestration systems (CFS) designed to collect and redirect daylight from the sky-vault are generally placed on the upper part of a window in order to improve the distribution of indoor daylight. Due to their additional function as solar protection, their use might contribute to the mitigation of the unfavourable effects that the admission of daylight signifies, especially in buildings located in prevailing sunny climates (risk of glare and overheating). An appropriate selection of the CFS that better contributes to improve the interior daylight environment would imply an integrated performance assessment taking into account relevant aspects such as indoor daylight distribution and the visual and thermal comfort of occupants. However, such an assessment implies the use of performance criteria with different targets; therefore, in order to evaluate their overall performance, a multi-criteria analysis is applied in this study. The method presented here describes a comprehensive evaluation to determine those CFS that better contribute to an improved indoor daylighting environment in a building located in a prevailing sunny climate. The CFS performance assessment was undertaken with computer simulations using their bi-directional transmission distribution function (BTDF)

Daylight regulated by automated external Venetian blinds based on HDR sky luminance mapping in winter

Automated shading systems have the potential to exploit daylight in buildings to save energy of artificial lighting and cooling loads and improve occupants'f visual comfort. This paper investigates the daylighting performance of automated Venetian blinds based on sky luminance monitoring and lighting computation in winter. 'fIn-situ'f experiments were carried out in a daylighting test module when the solar elevation angle was 21.7. at noon. Experimental results showed the automated shading was able to maintain work-plane illuminance within [500, 2000] lux range for 88% of the working time under a clear sky and for 83% of the working time under a partly cloudy sky, while mitigating discomfort glare for occupants

Urban District Energy Futures: A Dynamic Material Flow Analysis (MFA) Model

With more than half the world population now urbanised, urban metabolism – defined as the throughput and transformation of material and energy flows to sustain human life in urban settlements – is responsible for consuming the majority of global resources and the impact that this has on the environment. The identification, quantification and analysis of the main stocks and flows of energy and matter can support decision-making for a more sustainable urban resource use. Material Flow Analysis (MFA) is a method that has been widely used to study the metabolism of anthropogenic systems at a variety of scales. Yet the scale of the urban district has been addressed only scarcely. Often an established municipal unit for the purpose of planning, decision making and implementation, it is this district scale which is the subject of our study. In this we first present a mathematical MFA model (MMFA) for the simulation of energy and matter flows within our chosen urban district (Matthäus, Basle). We then go on to describe how this model was calibrated to this district. Various scenarios (with a special focus on energy) for the future optimisation of this status quo are discussed. We conclude by suggesting some promising strategies for the more sustainable development of Matthäus during the next fifteen years

Split-pane electrochromic window control based on an embedded photometric device with real-time daylighting computing

Well-designed electrochromic (EC) glazing control can improve the energy performance of buildings and visual comfort of occupants in highly glazed buildings. This paper designed and demonstrated a compact integrated EC glazing automation system to control tint states of a split-pane EC window according to variations of sky conditions. The control is based on monitoring the luminance distribution of the sky and real-time lighting computation for a building interior, using an embedded photometric device (EPD). It optimizes tint states of EC glazing to offer sufficient daylight provision and temper discomfort glare for occupants, which potentially mitigates excessive solar heat gain. ’In-situ’ experiments were conducted in a full-scale testbed to demonstrate the daylighting performance under various sky conditions. Experimental results showed 83% of the working time for work-plane illuminance (WPI) and 95% of the time for daylight glare probability (DGP) were constrained in comfort range (WPI[500, 2000] lux, DGP 0.35) by the automated EC glazing (controlled by EPD) under clear skies; 68% of the time for WPI and 94% of the time for DGP in confined range under clear skies with thin clouds; 62% of the time for WPI and 85% of the time for DGP in confined range under partly cloudy skies