Der Übergang eines Schülerjahrgangs in das Ausbildungssystem. Untersuchung zur realisierten Ausbildungsnachfrage Jugendlicher in Ostfriesland

Ziel der im Herbst 1977 und 1978 im Auftrag des Niedersächsischen Kultusministeriums durchgeführten Untersuchung war es, "für eine wirtschaftsstrukturschwache Region mit einem überdurchschnittlich hohen Anteil von Jugendlichen, die quantitative Dimension der Versorgung mit Ausbildungsplätzen zu bestimmen und Informationen über das Bewerbungsverhalten derjenigen zu bekommen, die nicht in eine Ausbildung eintraten."Ausbildungsplatzangebot, Bewerbungsverhalten, Schulabgänger, Ausbildungsverzicht, Ausbildungsplatznachfrage, strukturschwache Räume, Wirtschaftsstruktur, Ostfriesland, Niedersachsen, Aurich

Program FFlexCom — High frequency flexible bendable electronics for wireless communication systems

Today, electronics are implemented on rigid substrates. However, many objects in daily-life are not rigid — they are bendable, stretchable and even foldable. Examples are paper, tapes, our body, our skin and textiles. Until today there is a big gap between electronics and bendable daily-life items. Concerning this matter, the DFG Priority Program FFlexCom aims at paving the way for a novel research area: Wireless communication systems fully integrated on an ultra-thin, bendable and flexible piece of plastic or paper. The Program encompasses 13 projects led by 25 professors. By flexibility we refer to mechanical flexibility, which can come in flavors of bendability, foldability and, stretchability. In the last years the speed of flexible devices has massively been improved. However, to enable functional flexible systems and operation frequencies up to the sub-GHz range, the speed of flexible devices must still be increased by several orders of magnitude requiring novel system and circuit architectures, component concepts, technologies and materials

Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters

Polydimethylsiloxane (PDMS) is a promising biomaterial for generating artificial extracellular matrix (ECM) like patterned topographies, yet its hydrophobic nature limits its applicability to cell-based approaches. Although plasma treatment can enhance the wettability of PDMS, the surface is known to recover its hydrophobicity within a few hours after exposure to air. To investigate the capability of a novel PDMS-type (X-PDMS) for in vitro based assessment of physiological cell properties, we designed and fabricated plane as well as nano- and micrometer-scaled pillar-patterned growth substrates using the elastomer types S-, H- and X-PDMS, which were fabricated from commercially available components. Most importantly, we compared X-PDMS based growth substrates which have not yet been investigated in this context with H- as well as well-known S-PDMS based substrates. Due to its applicability to fabricating nanometer-sized topographic features with high accuracy and pattern fidelity, this material may be of high relevance for specific biomedical applications. To assess their applicability to cell-based approaches, we characterized the generated surfaces using water contact angle (WCA) measurement and atomic force microscopy (AFM) as indicators of wettability and roughness, respectively. We further assessed cell number, cell area and cellular elongation as indirect measures of cellular viability and adhesion by image cytometry and phenotypic profiling, respectively, using Calcein and Hoechst 33342 stained human foreskin fibroblasts as a model system. We show for the first time that different PDMS types are differently sensitive to plasma treatment. We further demonstrate that surface hydrophobicity changes along with changing height of the pillar-structures. Our data indicate that plane and structured X-PDMS shows cytocompatibility and adhesive properties comparable to the previously described elastomer types S- and H-PDMS. We conclude that nanometer-sized structuring of X-PDMS may serve as a powerful method for altering surface properties toward production of biomedical devices for cell-based applications

Supporting the changeability of SIPN-based logic control algorithms by verification and validation

International audienceIn this paper the advantages of verification and validation to support changes of an existing PLC program are shown. The controller is defined using Signal Interpreted Petri Nets (SIPN) and verification and validation are performed using symbolic model-checking. The main focus of this paper is to show the process and the benefits of verification and validation for the reliability of the control algorithm when specified changes are to make. This is clarified by the example of a heating tank controller throughout the text

Potential of 4H-SiC CMOS for high temperature applications using advanced lateral p-MOSFETs

In this work, the impact of the n-well doping concentration on the channel mobility and threshold voltage of p-MOSFETs and their applications in CMOS-devices is evaluated. For this purpose lateral p-channel MOSFETs with different channel lengths (L = 800 μm, 10 μm, 5 μm, and 3 μm) and doping concentrations (ND= 1015cm-3and 8·1015cm-3) were fabricated and the respective field-effect mobility was extracted from the transfer-characteristics. Comparable to n- MOSFETs the mobility of p-MOSFETs was found to be the highest for the lowest doping concentration in the channel and the absolute value of the threshold voltage increases with increasing doping concentration [3]. To investigate its suitability for CMOS applications, inverters with different doping concentrations for n- MOSFET (NA= 1015cm-3and 1017cm-3) und p- MOSFET (ND= 1015cm-3and 8·1015cm-3) were built. For logic levels of 0 V and 10 V, the voltage transfer characteristic with the highest input range was obtained for a low p-MOSFET and a high n- MOSFET doping concentration. The lowest propagation delay time could be achieved with a low p- MOSFET and a low n-MOSFET doping concentration. For temperatures up to 300 °C the drain current of p-MOSFETs with channel lengths below 3 μm is hampered by the series resistance of the source and drain region which limits the high-frequency performance of CMOS devices