37 research outputs found
Quinpramine Ameliorates Rat Experimental Autoimmune Neuritis and Redistributes MHC Class II Molecules
Activation of inflammatory cells is central to the pathogenesis of autoimmune demyelinating diseases of the peripheral nervous system. The novel chimeric compound quinpramine—generated from imipramine and quinacrine—redistributes cholesterol rich membrane domains to intracellular compartments. We studied the immunological and clinical effects of quinpramine in myelin homogenate induced Lewis rat experimental autoimmune neuritis (EAN), a model system for acute human inflammatory neuropathies, such as the Guillain-Barré syndrome. EAN animals develop paresis of all limbs due to autoimmune inflammation of peripheral nerves. Quinpramine treatment ameliorated clinical disease severity of EAN and infiltration of macrophages into peripheral nerves. It reduced expression of MHC class II molecules on antigen presenting cells and antigen specific T cell proliferation both in vitro and in vivo. Quinpramine exerted its anti-proliferatory effect on antigen presenting cells, but not on responder T cells. Our data suggest that quinpramine represents a candidate pharmaceutical for inflammatory neuropathies
Die Schneeschmelze eines nordskandinavischen Einzugsgebietes ermittelt über die räumlich-zeitliche Variation des Strahlungs- und Energiehaushalts
Vorliegende Untersuchung stellt einen Beitrag zur Forschung in der Schneehydrologie dar. Dem wachsenden Bedürfnis der Wasserwirtschaft, Informationen über Schneedeckenauf- und -abbau und die Möglichkeiten der Modellbildung zu erhalten, wurde folgende Untersuchung am Beispiel eines nordskandinavischen Einzugsgebietes, des 53,9 km2 großen Isdalen, durchgeführt. Ausgehend vom derzeitigen Stand der Forschung, in der Schneeschmelzmodelle als "Stations- oder Punktmodelle" existieren, werden in dieser Arbeit raumbezogene differenzierte Gebietsmodelle vorgestellt.researchDFG, SUB Göttinge
De Variis Literatorum Fatis ... Oratione, A. H. MDCXXCV. D. XXVI Iul. H. X. Matut. In Auditorio Athenaei Maximo ... Habenda, Verba Facere Constituit Godofredus Stüve, Gedanensis. Ad Quem Benevole, Lubenterque Audiendum, Honestissimorum Studiorum Patronos, Maecenates, Fautores ... Invitat; Iuventutem Vero, Studiis Honestissimis Deditam, Peramanter Convocat Joh. Petr. Titius, Eloqu. Et Poet. Prof.
DE VARIIS LITERATORUM FATIS ... ORATIONE, A. H. MDCXXCV. D. XXVI IUL. H. X. MATUT. IN AUDITORIO ATHENAEI MAXIMO ... HABENDA, VERBA FACERE CONSTITUIT GODOFREDUS STÃœVE, GEDANENSIS. AD QUEM BENEVOLE, LUBENTERQUE AUDIENDUM, HONESTISSIMORUM STUDIORUM PATRONOS, MAECENATES, FAUTORES ... INVITAT; IUVENTUTEM VERO, STUDIIS HONESTISSIMIS DEDITAM, PERAMANTER CONVOCAT JOH. PETR. TITIUS, ELOQU. ET POET. PROF.
De Variis Literatorum Fatis ... Oratione, A. H. MDCXXCV. D. XXVI Iul. H. X. Matut. In Auditorio Athenaei Maximo ... Habenda, Verba Facere Constituit Godofredus Stüve, Gedanensis. Ad Quem Benevole, Lubenterque Audiendum, Honestissimorum Studiorum Patronos, Maecenates, Fautores ... Invitat; Iuventutem Vero, Studiis Honestissimis Deditam, Peramanter Convocat Joh. Petr. Titius, Eloqu. Et Poet. Prof. (1)
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Smart Composites enabled by Smart Textiles: über Möglichkeiten und Anforderungen
Faserverstärkte Kunststoffe (Composites) bestehen aus den Komponenten hochfeste Fasern und druckfestes Harz, das die Fasern einbettet und gegen Knicken schützt. Composites aus Carbonfasern finden heutzutage in Primärstrukturen von Flugzeugen wie dem Airbus A350 oder der Boeing 787 Verwendung. Sie übernehmen dort ausschließlich strukturelle und formgebende Funktionen. Mit fortschreitender Entwicklung, z.B. von Health Monitoring Systemen, gewinnt der Aspekt der Funktionsintegration und damit der Möglichkeit, die Leitung für Elektrizität und Signalübertragung in die Struktur, bzw. den Werkstoff zu integrieren, immer mehr an Bedeutung. Aufgrund der erforderlichen Produktionsraten für Flugzeuge spielt der Automatisierungsgrad eine entscheidende Rolle. Hierbei gewinnen Smart Textiles an Bedeutung, sofern es gelingt smarte textile Halbzeuge herzustellen, die mit den etablierten Fertigungstechnologien der Composite- und Luftfahrtbranche verarbeitet werden können. Der Vortrag gibt einen Überblick über die relevanten Fertigungstechnologien von Compositebauteilen in der Luftfahrtbranche und diskutiert die Anforderungen an Smart Textiles, um zur Herstellung von Smart Composites genutzt zu werden. Darüber hinaus werden Beispiele von prototypischen Umsetzungen von Smart Composites vorgestellt und diskutiert, wie integrierte Leiterbahnen in eine Galley-Rückwand (Küchenwand im Flugzeug) und die Integration von Lambwellen-Sensoren in eine Flugzeugrumpfstruktur zur Realisierung von Structural-Health-Monitoring der Struktur
Reconstruction of Lake Level Changes of Groundwater-Fed Lakes in Northeastern Germany Using RapidEye Time Series
Groundwater-fed lakes in northeastern Germany are characterized by significant lake level changes, but for only a few lakes are in situ water level measurements available. In this study, we test the potential of RapidEye satellite images for indirectly reconstructing lake level changes. The lake levels are derived by intersecting water-land borders with a high-resolution digital elevation model (DEM). Based on Lake Fürstenseer (LF), we define requirements and limitations of the method. Water-land borders were extracted automatically from the 37 RapidEye images available for the period between 2009 and 2014. Otsu’s threshold was used for the NIR band and for the normalized difference water index (NDWI). The results were validated with in situ gauging, contour lines from the DEM, and in situ Differential Global Positioning System (DGPS) measurements of the shoreline. Using an ideal shoreline subset, the lake levels could be reconstructed with decimeter accuracy using the NIR water-land border, but the levels were systematically underestimated by 0–20 cm. The accuracy of the reconstructed lake level retrieval strongly depends on the precision of the water-land border retrieval, on the accuracy of the DEM, and on the lake level itself. A clear shift of the water-land border with increasing lake level is also essential for the unambiguous reconstruction of different levels. This shift needs to be several times larger than the pixel size. The biggest challenges for lake level reconstruction are the presence of vegetation at the shorelines, the quality of the topographic data in the underwater area, the slope of the shoreline, and shadows in combination with low solar angles
Fertigung von Faserverbundstrukturen mittels kooperierender Robotereinheiten
Am Zentrum für Leichtbauproduktionstechnologie (ZLP®) Stade des Deutschen Zentrums für Luft- und Raumfahrt (DLR) wird mit dem Einsatz mehrerer kooperierender Roboter in der automatisierten Faserablage ein Ansatz verfolgt, Fertigungszeiten und kosten für Strukturbauteile aus Faserverbund signifikant zu senken. Doch funktioniert dieser Ansatz? Wie wird eine zeiteffiziente Aufgabenverteilung auf mehrere Robotereinheiten realisiert? Der weltweit erste Nachweis der Mehrkopf-Faserlegetechnologie gibt Aufschluss
Inconsistent hydrological trends do not necessarily imply spatially heterogeneous drivers
Trend analyses are widely used to check for climate change effects on hydrological systems. However, often inconsistent patterns have been found, that is, non-significant as well as significant but opposing trends in the same data set. These inconsistencies have often been ascribed to local, mostly anthropogenic effects like wetland draining or land use change. In this study local effects were subtracted from time series of lake water level and groundwater head covering a 28 years period in Northeast Germany. But this did hardly affect the observed inconsistent trends. In contrast, the apparent inconsistent behavior could be ascribed to different degrees of low-pass filtering of the groundwater recharge signal. Due to successively increasing attenuation of high frequency oscillations during the passage through the vadose zone minor long-term oscillations in the input signal became increasingly more visible, resulting in apparent monotonic trends for the 28 year period. There is strong evidence that this phenomenon could be ascribed to frequency-dependent damping of the input signal which has been found for a wide range of natural processes, including hydrological systems
Design Optimization of a CFRP Wing Cover for the AFP Process
The economic application of carbon fiber reinforced plastics in large-scale aerospace structures demands cost-efficient production technologies. In recent years, much progress was achieved in automation engineering, like automated fiber placement (AFP) and automated tape laying (ATL) technologies.
In the design process, new methods have been established to incorporate boundary conditions of the production process. Henceforth the optimization process is not only focused on weight-reduction, but on an improved cost/weight ratio. Most research on this topic has been done in the field of conceptual design, as the highest percentage of the later arising manufacturing cost is defined by decisions made in the early design phase.
But there is also a potential for reducing production cost in the detailed design phase. In the Composite Design department of the DLR Institute of Composite Structures and Adaptive Systems the detailed design of a wing cover skin section was optimized for the AFP-process. Ply shapes and ramp geometries have been modified to reduce the number of courses needed for ply-layup, and thus to reduce production time. Uncomplete courses with less than all of the available tows, as well as repeated stops and acceleration of the fiber-placement head due to unnecessary tow-cutting processes have been avoided.
With these approaches the total layup time was reduced by 3,4% whereas the on-surface time of the fibre placement heads decreased by even 5% compared to the reference design, while structural weight remained constant. The optimization strategies, originally developed for the AFP-process, are also applicable to the ATL-process.
The optimized design was analyzed in 3 sections and compared to the reference design for 408 combinations of longitudinal, transversal and shear loads, showing only minor differences in strength and stability