Combined effect of light harvesting strings,anti‐reflective coating,thin glass,and high ultraviolet transmission encapsulant to reduce optical losses in solar modules

Optical losses are a major source for current and power reduction in solar modules. Hence, various improvements aiming at reducing these losses have been suggested. In this work, we have evaluated the effects of anti‐reflective coating, front glass thickness, polyvinyl butyral ultraviolet+ encapsulant, and light harvesting strings on the module performance individually and in combination. The individual and combined contributions were quantified by spectrally resolved optical measurements on the module components and simulations as well as electrical measurements on 1‐cell and 54‐cell modules. Optical gains and their impact on short circuit current are discussed in relation to a maximum current obtained from the solar cells internal quantum efficiency. The results of the electrical characterization are in good agreement with the optical analysis substantiating our approach. They show that a combined, relative current enhancement of 5% can be obtained for an optimized module, which compares to an increase of 1% absolute efficiency. Copyright © 2014 John Wiley & Sons, Ltd.     

Dark roast coffee is more effective than light roast coffee in reducing body weight, and in restoring red blood cell vitamin E and glutathione concentrations in healthy volunteers

Recent results from prospective cohort studies have shown that moderate coffee consumption is associated with a reduced risk for diabetes mellitus type II or Alzheimer's disease. Since reactive oxygen species (ROS) are believed to be involved in the pathogenesis of these diseases, antioxidants in coffee might contribute to this risk reduction. We aimed at elucidating whether a dark roast coffee beverage (CB) rich in N‐methylpyridinium ions (NMP: 785 μmol/L) and low in chlorogenic acids (CGA: 523 μmol/L) has stronger antioxidant effects on human erythrocytes than a CB prepared from a light roast with opposite proportions (CGA: 4538 μmol/L; NMP: 56 μmol/L). Following a 2‐wk wash out period, 500 mL of the respective CB was administered to 30 subjects daily for 4‐wk. Blood and spot urine samples were collected at the beginning and at the end of each intervention. Intake of the dark roast CB most effectively improved the antioxidant status of erythrocytes: superoxide dismutase and glutathione peroxidase activity decreased by 5.8 and 15%, respectively, whereas tocopherol and total glutathione concentrations increased by 41 and 14%, respectively. Furthermore, administration of the NMP‐rich CB led to a significant body weight reduction in pre‐obese subjects, whereas the CGA‐rich CB did not.     

Einsatz von Mikroplasmen für die Herstellung von Silizium‐Mehrlagenaufbauten

Micro Plasma Processes for MEMS Packaging The encapsulation of MEMS devices can be difficult, since released micromechanical parts (e.g. membranes, valves, and cantilevers) tend to stick to the surrounding surfaces. Area‐selective surface modification is a new approach, developed by the Fraunhofer‐Institute for Surface Engineering and Thin Films (IST), to overcome these problems. From a more general point of view, area‐selective surface tailoring with microplasmas is an attractive topic for micro systems production. The business transfer of the technique by implementation into the SU SS mask is currently being evaluated.     

UV Effect on Human Anterior Lens Capsule Macro-Molecular Composition Studied by Synchrotron-Based FTIR Micro-Spectroscopy

Ultraviolet (UV) irradiation is an important risk factor in cataractogenesis. Lens epithelial cells (LECs), which are a highly metabolically active part of the lens, play an important role in UV-induced cataractogenesis. The purpose of this study was to characterize cell compounds such as nucleic acids, proteins, and lipids in human UV C-irradiated anterior lens capsules (LCs) with LECs, as well as to compare them with the control, non-irradiated LCs of patients without cataract, by using synchrotron radiation-based Fourier transform infrared (SR-FTIR) micro-spectroscopy. In order to understand the effect of the UV C on the LC bio-macromolecules in a context of cataractogenesis, we used the SR-FTIR micro-spectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve a single-cell resolution with high spectral stability and high photon flux. UV C irradiation of LCs resulted in a significant effect on protein conformation with protein formation of intramolecular parallel β-sheet structure, lower phosphate and carboxyl bands in fatty acids and amino acids, and oxidative stress markers with significant increase of lipid peroxidation and diminishment of the asymmetric CH₃ band.     

Modifying the 5-position of thieno[2,3-d][1,2,3]thiadiazole-6-carboxylate derivatives

Thieno[2,3-d][1,2,3]thiadiazole-6-carboxylates 3 belong to a new group of plant protecting agents as highly potent inducers of systemic acquired resistance (SAR). In order to obtain an enhanced basis set for structure activity relationship studies several modifications of the heteroaromatic core were performed by introduction of various substituents. One approach utilizing metallation techniques led to several 5-substituted derivatives 4a – h of the title compound. Using the chloro-compound 5 obtained via this route the ability to undergo nucleophilic substitution reactions was investigated, representing a complementary strategy towards derivatives 6a – c .     

Analysis of light scattering in amorphous Si:H solar cells by a one‐dimensional semi‐coherent optical model

A one‐dimensional semi‐coherent optical model for thin‐film solar cells is presented. The optical circumstances at flat interfaces are addressed and the situation at rough interfaces in the model is described for the case of direct (coherent) incident and scattered (incoherent) incident light. After the model has been experimentally verified, analysis of the light scattering process in hydrogenated amorphous silicon (a‐Si:H) p–i–n solar cells is carried out. The influence of the interface root‐mean‐square roughness and the effect of different angular distribution functions of diffused light on quantum efficiency and short‐circuit current are investigated by the optical model. Copyright © 2002 John Wiley & Sons, Ltd.     

Verhalten von hochduktilem Beton unter Impaktbelastung

In diesem Aufsatz wird das Materialverhalten von Hochduktilem Beton (engl.: Strain Hardening Cementitious Composite – SHCC) bei Impaktbelastung beschrieben. Dazu werden Ergebnisse aus hochdynamischen Spallations‐Experimenten an einem Hopkinson‐ Bar mit Dehnraten > 140 1/s den Resultaten aus quasi‐statischen, zentrischen Zugversuchen mit Dehnraten von 0,001 1/s gegenübergestellt. Die Auswirkungen hoher Dehnraten auf das Materialverhalten erfolgt anhand eines Vergleiches der zentrischen Zugfestigkeit, des E‐Moduls sowie der Bruchenergie. Die experimentellen Ergebnisse werden zudem mit den Kennwerten anderer Betone in Beziehung gesetzt. Unterschiede im Materialverhalten werden auf Grundlage von Phänomenen der Rissbildung und des Faserauszuges erklärt. Mechanical Behaviour of SHCC under Impact This paper describes the material behaviour of Strain Hardening Cementitious Composite (SHCC) at high strain rates. The results of high dynamic spall experiments using a Hopkinson Bar at strain rates > 140/sec were arrayed against the results of quasistatic, centric tensile tests at strain rates of 0,001/sec. This comparison is based on the parameters of tensile strength, elastic modulus, and fracture energy of the specimens. In addition, the experimental results of SHCC are related to the characteristic values of other concrete types. Differences in material behaviour are explained by the phenomena of crack formation and fibre pullout force.