45 research outputs found

    Air cooling powered by façade integrated coloured opaque solar thermal panels

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    For building integration of solar-powered energy systems, aesthetic aspects play an importantrole. Covering a standard solar collector with a coloured glazing, opaque to the human eye but highly transparent to solar energy, permits a perfect architectural integration of solar thermal panels into glazed building façades. The thermal energy produced can be used for both solar heating and cooling, as well as for domestic hot water. The principle of the coloured appearance is based on interference in the thin-film coating on the reverse side of the cover glass. Different interference filters based on nano-composite materials deposited by the solgel method were presented at CISBAT 2007 [1]. Currently, we are developing new plasma-deposition processes, which are more suitable for industrial large-scale production. A new state-of-the-art ultra-high vacuum (UHV) system for magnetron sputtering deposition of novel nano-composite solar coatings has recently been designed, constructed, and installed at the Solar Energy and Building Physics Laboratory (LESO-PB). Up to five different magnetron sources can be used simultaneously, in reactive and non-reactive mode. The geometric configuration of the chamber has been optimised for best film homogeneity and allows the deposition on substrates up to 100 mm in diameter. The optical and electronic properties of thin films are closely interrelated and highly relevant for solar coatings. Photoelectron spectroscopy provides information on the coating structure, the deposited material and its chemical state inside the coating, as well as the nature of the interface between different layers. A system for ESCA analysis (Electron Spectroscopy for Chemical Analysis) has recently been installed and put into operation at LESO-PB. By ellipsometry and spectrophotometry, we can determine exactly the different optical properties of the coating, such as layer thickness, refractive index, or absorption coefficient. This provides best conditions for highly efficient research and development on new materials for further optimisation of the coloured interference filters.First results have been obtained with our new experimental infrastructure and will be presented in this contribution

    Frameshift Variant in MFSD12 Explains the Mushroom Coat Color Dilution in Shetland Ponies

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    Mushroom is a unique coat color phenotype in Shetland Ponies characterized by the dilution of the chestnut coat color to a sepia tone and is hypothesized to be a recessive trait. A genome wide association study (GWAS), utilizing the Affymetrix 670K array (MNEc670k) and a single locus mixed linear model analysis (EMMAX), identified a locus on ECA7 for further investigation (Pcorrected = 2.08 × 10−10). This locus contained a 3 Mb run of homozygosity in the 12 mushroom ponies tested. Analysis of high throughput Illumina sequencing data from one mushroom Shetland pony compared to 87 genomes from horses of various breeds, uncovered a frameshift variant, p.Asp201fs, in the MFSD12 gene encoding the major facilitator superfamily domain containing 12 protein. This variant was perfectly concordant with phenotype in 96 Shetland Ponies (P = 1.15 × 10−22), was identified in the closely related Miniature Horse for which the mushroom phenotype is suspected to occur (fmu = 0.02), and was absent in 252 individuals from seven additional breeds not reported to have the mushroom phenotype. MFSD12 is highly expressed in melanocytes and variants in this gene in humans, mice, and dogs impact pigmentation. Given the role of MFSD12 in melanogenesis, we propose that p.Asp201fs is causal for the dilution observed in mushroom ponies

    Decreasing Interface Defect Densities via Silicon Oxide Passivation at Temperatures Below 450 degrees C

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    Low-temperature (LT) passivation methods (700 degrees C). Therefore, the LT passivation of SiOx/Si has long been a research topic to improve application performance. Here, we demonstrate that an LT (<450 degrees C) ultrahigh-vacuum (UHV) treatment is a potential method that can be combined with current state-of-the-art processes in a scalable way, to decrease the defect densities at the SiOx/Si interfaces. The studied LT-UHV approach includes a combination of wet chemistry followed by UHV-based heating and preoxidation of silicon surfaces. The controlled oxidation during the LT-UHV treatment is found to provide an until now unreported crystalline Si oxide phase. This crystalline SiOx phase can explain the observed decrease in the defect density by half. Furthermore, the LT-UHV treatment can be applied in a complementary, post-treatment way to ready components to decrease electrical losses. The LT-UHV treatment has been found to decrease the detector leakage current by a factor of 2

    Effects of post oxidation of SiO2/Si interfaces in ultrahigh vacuum below 450 °C

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    Growing SiO2 layer by wet-chemical oxidation of Si surfaces before growth of another insulating film(s) is a used method to passivate Si interfaces in applications (e.g., solar cell, photodiode) at low temperatures (LT) below 450 °C. We report on potential of LT ultrahigh-vacuum (UHV) treatments combined with the wet-chemical oxidation, by investigating effects of LT-UHV oxidation after the wet-chemical growth of SiO2 and before growing Al2O3 film on top of SiO2/Si. This method modifies the SiO2/Si and is found to (i) decrease defect-level density, (ii) increase negative fixed charge density, and (iii) increase carrier lifetime for Al2O3/SiO2/p-Si, as compared to state-of-the-art SiO2/p-Si reference interfaces without LT-UHV. X-ray photoelectron spectroscopy shows that the LT-UHV treatment decreases amount of Si+3 oxidized atoms in chemically grown SiO2 and also amount of carbon contamination. In order to pave the way for further tests of LT-UHV in silicon technology, we present a design of simple UHV instrument. The above-described benefits are reproduced for 4-inch silicon wafers by means of the instrument, which is further utilized to make LT-UHV treatments for complementary SiO2/Si interfaces of the native oxide at silicon diode sidewalls to decrease the reverse bias leakage current of the diodes.​​​​​​​</ul

    Updated Guidance Regarding The Risk ofAllergic Reactions to COVID-19 Vaccines and Recommended Evaluation and Management: A GRADE Assessment, and International Consensus Approach

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    This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against \u3e 15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history

    Development of innovative coatings for sun protection glasses based on the theory of the optimal spectral transmittance

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    In this work new coatings for sun protection glasses for windows and glass facades were developed. These coatings improve the reduction of the energy input by solar radiation in comparison to the best sun protection glasses on the market. They reduce the cooling load of buildings and therefore contribute to the measures to reduce global climatic changes on earth. The new developed coatings are multilayer systems which are based on the principle of Fabry-Perot interference filters. The thin film multilayer systems are deposited on glass by magnetron sputtering under high vacuum conditions. The materials used in those coatings are silver, zinc oxide, titanium dioxide and silicon dioxide. Different coating designs were developed based on two bandpass filters, a metal-dielectric and an enhanced metal-dielectric filter. They were optimised to have a low energy load coefficient τe /τv and at the same time a stable colour appearance and a colour neutral light transmittance τv . The new coatings have energy load coefficients τe /τv between 0.339 and 0.398. For comparison one of the best commercial sun protection glass has an energy load coefficient of τe /τv = 0.429. A theoretical limit for this coefficient was determined to be at 0.334 if colour neutrality of the transmitted light is required

    Energy Trading and Risk Management: A Practical Approach to Hedging, Trading and Portfolio Diversification

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    Generalized Picard-Lindelf theory

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