CPVMatch - Concentrating photovoltaic modules using advanced technologies and cells for highest efficiencies

This paper presents the project Concentrating Photovoltaic modules using advanced technologies and cells for highest efficiencies (CPVMatch), which is funded from the European Union’s Horizon 2020 research and innovation programme. V multi-junction solar cells and CPV modules. Concerning cells, novel wafer bonded four-junction solar cells made of GaInP/GaAs//GaInAs/Ge are optimized with the target of reaching 48% efficiency under concentration at the end of the project. Moreover, multi-junction solar cell technologies with advanced materials - like ternary IV element mixtures (i.e. SiGeSn) and nanostructured anti-reflective coatings - are investigated. Concerning CPV modules the project focuses on both Fresnel-based and mirror-based technologies with a target efficiency of 40% under high concentrations beyond 800x. Achromatic Fresnel lenses for improved light management without secondary optics are investigated. In addition, smart, mirror-based HCPV modules are developed, which include a new mirror-based design, the integration of high efficiency, low cost DC/DC converters and an intelligent tracking sensor (PSD sensor) at module level. A profound life-cycle and environmental assessment and the development of adapted characterization methods of new multi-junction cells and HCPV modules complete the work plan of CPVMatch

High prevalence of Trichomonas gallinae in wild columbids across western and southern Europe

Avian trichomonosis is known as a widespread disease in columbids and passerines, and recent findings have highlighted the pathogenic character of some lineages found in wild birds. Trichomonosis can affect wild bird populations including endangered species, as has been shown for Mauritian pink pigeons Nesoenas mayeri in Mauritius and suggested for European turtle doves Streptopelia turtur in the UK. However, the disease trichomonosis is caused only by pathogenic lineages of the parasite Trichomonas gallinae. Therefore, understanding the prevalence and distribution of both potentially pathogenic and non-pathogenic T. gallinae lineages in turtle doves and other columbids across Europe is relevant to estimate the potential impact of the disease on a continental scale

UCOL project: recent advances

UCOL (which stands for Ultra-wideband Coherent Optical LAN) is a system aiming to provide integrated support of narrowband and broadband services (data, voice and video) to the need of specific localized communication environments. This report presents the advances of UCOL after the first year of the realization phase. A number of modifications have been made since the original plan, allowing the project to be feasible applying current technology. The new approach to the physical layer is described together with the already developed optical subsystems; finally the UCOL access protocol is reported

Substrate distortion and the catalytic reaction mechanism of 5-carboxyvanillate decarboxylase

5-Carboxyvanillate decarboxylase (LigW) catalyzes the conversion of 5-carboxyvanillate to vanillate in the biochemical pathway for the degradation of lignin. This enzyme was shown to require Mn2+ for catalytic activity and the kinetic constants for the decarboxylation of 5-carboxyvanillate by the enzymes from Sphingomonas paucimobilis SYK-6 (kcat = 2.2 s–1 and kcat/Km = 4.0 × 104 M–1 s–1) and Novosphingobium aromaticivorans (kcat = 27 s–1 and kcat/Km = 1.1 × 105 M–1 s–1) were determined. The three-dimensional structures of both enzymes were determined in the presence and absence of ligands bound in the active site. The structure of LigW from N. aromaticivorans, bound with the substrate analogue, 5-nitrovanillate (Kd = 5.0 nM), was determined to a resolution of 1.07 Å. The structure of this complex shows a remarkable enzyme-induced distortion of the nitro-substituent out of the plane of the phenyl ring by approximately 23°. A chemical reaction mechanism for the decarboxylation of 5-carboxyvanillate by LigW was proposed on the basis of the high resolution X-ray structures determined in the presence ligands bound in the active site, mutation of active site residues, and the magnitude of the product isotope effect determined in a mixture of H2O and D2O. In the proposed reaction mechanism the enzyme facilitates the transfer of a proton to C5 of the substrate prior to the decarboxylation step

Wafer bonding with an adhesive coating

The assembly process for microelectromechanical systems often requires a wafer-joining process using low temperatures. In this work a bonding process is investigated, which uses thin adhesive films to stack silicon wafers. The method can be extended to form patterned adhesive coatings using stamping technique. Characterization of the process has been carried out with respect to adhesion, hermeticity and chemical stability of the adhesive bond.. in several applications this adhesive bonding process has been successfully applied to assemble sensors and actuator

Auswerteschaltung zur Ermittlung komplexer Impedanzen, Vorrichtung zur Messung komplexer Impedanzen und Verwendung der Vorrichtung

NOVELTY - The circuit to evaluate complex impedances has a voltage supply with a frequency generator (8) to give digital signals, a 1:2 frequency divider (9), and a unit (10) to give two alternating voltage signals with a 90 deg. phase shift with the first frequency. The phase shift remains during a frequency variation. DETAILED DESCRIPTION - The frequency generator (8) gives a signal of twice the first frequency and a scanning ratio of 50%, or four times the first frequency where the voltage supply has a second 1:2 frequency divider. The unit (10) to give two alternating voltage signals is a D-flip-flop. The signals from the amplifier and the phase shifted signals are combined to give two output signals to show the real and imaginary parts of the impedance, using a half-wave or full-wave rectifier. A deep pass filter is in front of the current supply. The links between the sensor and amplifier are shrouded. The amplifier has a buffer amplifier with an amplification factor of V=1. The outer lead of the shrouding is linked to the buffer amplifier output. The amplifier has connections for positive and negative supply voltages, each with a resistance connection to the supply voltage. A voltage stabilizer is linked to the amplifier output. One or more sensors each have two electrodes to register the complex impedance. A signal converter switches the input of the evaluation circuit between the separate sensors. The electrodes are covered with a thin insulation layer of silicon carbide, in comparison to the gap between the electrodes, which has high chemical stability in a layer thickness of 0.2-2.0 mu m. The sensor is a surface wave sensor, with capacitative electrodes, and the assembly can register other measured values. The sensor can be fitted with interdigital electrodes on the substrate of the surface wave sensor, where one is the interdigital electrodes of a pair of measurement electrodes. USE - The apparatus is for measurement of fluid characteristics, the aging o f lubricant oil, the moisture content in soil, to measure ion concentrations, to determine the water content in liquids with low dielectric values, to determine the water content in alcohol or oil and vice versa, to register the water content in brake fluid, to measure the composition of milk, the time point of concrete hardening, to measure the contamination of soil by oil or acids, to identify acids and lyes in water and measure their concentration, and the like. ADVANTAGE - The circuit gives a constant phase shift even during temp. changes and frequency alterations without any complex phase smoothing systems

Novel microstructuring technologies in silicon

Two microstructuring processes are described in the paper: A high performance RIE process (STS Advanced Silicon Etch), which is in many cases a benefical replacement for conventional, anisotropic silicon etch techniques. Furthermore a technology using porous silicon as sacrificial layer in a surface micromachining process. Porous silicon has some favourable properties, compared to other sacrificial layers as layer thickness up to 100mu m. The capabilities of these processes are illustrated by several of MEMS applications carried out at the Fraunhofer Institute for Solid State Technology