557 research outputs found
Detection of Karst Features in the Black Hills Area in South Dakota/Wyoming, USA, Based on Evaluations of Remote Sensing Data
Landsat 8, Sentinel 2, Aster, RapidEye and PlanetScope data and Sentinel 1- and Advanced Land Observing Satellite (ALOS)-Phased Array type L-band Synthetic Aperture Radar (PALSAR)-radar images have been evaluated for a karst feature inventory in the Black Hills area in Wyoming/South Dakota, USA. The GeoInformation System (GIS) integrated evaluation of the different satellite data included as well World Imagery files of ESRI and Bing Maps high resolution satellite data of Microsoft. The satellite data revealed several types of circular features related to karst such as enclosed depressions and collapsed dolines as well as traces of tectonic/structural features (visualized by lineament analysis) cutting through youngest sediments, influencing karstification processes. The origin of the circular features is complex and partly unknown, needing further investigations. Digital Elevation Model (DEM) data, such as Aster- and Shuttle Radar Topography Mission (SRTM) DEM data with 30 m and ALOS PASAR DEM with 12.5 m spatial resolution contributed to the detection of depressions, partly related to karst phenomena (sinkholes). Time series of satellite data reveal seasonal changes of the landscape and provide a data base for the documentation of the impact of climate change
Detection of Ring Structures and Their Surrounding Tectonic Pattern in South-Algeria, North-Mali and North- Niger based on Satellite Data
This study is focused on the detection of circular features with different sizes, origins, and state of erosion as well as on their surrounding tectonic pattern based on different satellite images of Southern Algeria, Northern Mali and Northern Niger. Sentinel 2- and Landsat 8/9-images and Sentinel 1- and ALOS L-band Phased Array Synthetic Aperture Radar (PALSAR)-radar data help to identify larger ring structures and smaller circular features, most of them related to magmatic intrusions into the subsurface, but also to cosmic impacts, with varying ages and state of erosion. Some of them seem to be unknown so far as they are partly covered by aeolian sediments and become only visible on radar images. Digital Elevation Model (DEM) data and the DEM derived morphometric maps support these investigations in a GeoInformation System (GIS) embedded environment. Some of the ring structures are only visible on morphometric maps, traced by circular arrangements of slope gradients or concentric drainage patterns. The large, circular structures and the smaller circular features such as volcanic features (cinder cones, calderas, maars, impact craters) were digitized and merged in a GIS with available geologic information
TSUNAMI HAZARD IN NORTHERN VENEZUELA
Based on LANDSAT ETM and Digital Elevation Model (DEM) data derived by the Shuttle Radar Topography Mission (SRTM, 2000) of the coastal areas of Northern Venezuela were investigated in order to detect traces of earlier tsunami events. Digital image processing methods used to enhance LANDSAT ETM imageries and to produce morphometric maps (such as hillshade, slope, minimum and maximum curvature maps) based on the SRTM DEM data contribute to the detection of morphologic traces that might be related to catastrophic tsunami events. These maps combined with various geodata such as seismotectonic data in a GIS environment allow the delineation of coastal regions with potential tsunami risk. The LANDSAT ETM imageries merged with digitally processed and enhanced SRTM data clearly indicate areas that might be prone by flooding in case of catastrophic tsunami events
DETECTION OF LOCAL SITE CONDITIONS INFLUENCING EARTHQUAKE SHOCK AND SECONDARY EFFECTS IN THE VALPARAISO AREA IN CENTRAL-CHILE USING REMOTE SENSING AND GIS METHODS
The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in Valparaiso in Chile in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integrated into a spatial database using Geoinformation Systems (GIS) and image processing techniques. The GIS integrated evaluation of satellite imageries, of digital topographic data and of various open-source geodata can contribute to the acquisition of those specific tectonic, geomorphologic/ topographic settings influencing local site conditions in Valparaiso, Chile. Using the weighted overlay techniques in GIS, susceptibility maps were produced indicating areas, where causal factors influencing near- surface earthquake shock occur aggregated. Causal factors (such as unconsolidated sedimentary layers within a basin’s topography, higher groundwater tables, etc.) summarizing and interfering each other, rise the susceptibility of soil amplification and of earthquake related secondary effects. This approach was used as well to create a tsunami flooding susceptibility map. LANDSAT Thermal Band 6-imageries were analysed to get information of surface water currents in this area
Effects of flavour absorption on foods and their packaging materials
Keywords: flavour absorption, scalping, packaging, food matrix, lldpe, ldpe, pp, pc, pet, pen,b-lactoglobulin, casein, pectin, cmc, lactose, saccharose, oil, modelling, storage, oxygen permeability, taste perception, sensory quality.Absorption of flavour compounds by linear low-density polyethylene (LLDPE) was studied in model systems representing differences in composition of the food matrix. Proteins,b-lactoglobuline and casein, were able to bind flavours, resulting in suppression of absorption of flavour compounds. Polysaccharides, pectin and carboxymethylcellulose, increased viscosity, and consequently decreased absorption. Disaccharides, lactose and saccharose, increased absorption, probably caused by a "salting out" effect of less apolar flavour compounds. The presence of a relative small amount of oil (50 g/l) decreased absorption substantially. Combined oily model systems, oil/casein and oil/pectin, showed a similar effect. The extent of absorption of flavour compounds by LLDPE was influenced by food components in the order: oil or fat >> polysaccharides and proteins > disaccharides. A model based on the effect of the polarity (log P) of flavour compounds and on their partitioning coefficients between food(matrix) and packaging material was developed. The model is able to predict absorption of flavour compounds from foods into LLDPE when lipids in the food matrix are the determining factor in flavour absorption. Results show that the model fits nicely with experimental data of real foods skim and whole milk.LLDPE, polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET film and PET bottle) and polyethylene naphthalate (PEN) were immersed in a model flavour solution at different temperatures up to 14 days. The absorption rate and/or total amount of absorbed compounds increased considerably with increasing temperature. Depending on temperature, the total absorption of flavour compounds by the polyolefins (LLDPE and PP) was up to 2400 times higher than by the polyesters (PC, PET and PEN).The effect of absorbed flavour compounds on the oxygen permeability of low-density polyethylene (LDPE), PP, PC and PET was studied. Due to swelling of the polymers as a result of absorption of flavour compounds, LDPE and PP showed a significant increase of oxygen permeability of 21% and 130%. The oxygen permeability of PC showed a significant decrease of 11% due to occupation or blockage of the "micro-cavities" by the absorbed flavour compounds. Flavour absorption by PET did not affect the oxygen permeability significantly.The influence of flavour absorption LDPE, PC and PET on the taste perception of a flavour model solution and orange juice stored in glass bottles was studied with and without pieces of the respective plastic films. Although the content of flavour compounds between controls and polymer treated samples decreased substantially due to absorption, no significant effect on the taste perception of the model solution and orange juice were observed by triangular taste panel tests.</font
Wie international ist die Promotion in Deutschland? Eine Analyse auf Basis der National Academics Panel Study
In der hier vorgestellten Sonderauswertung der 1. Welle der National Academics Panel Study (Nacaps) werden zwei Perspektiven der Internationalität der Promotion in Deutschland behandelt: die temporäre promotionsbezogene Auslandsmobilität inländischer Promovierender sowie die Situation internationaler Promovierender in Deutschland. Im Fokus der Betrachtung der inländischen Promovierenden steht die Frage, welchen Nutzen sie Auslandsaufenthalten zuschreiben und welche Hindernisse sie diesbezüglich wahrnehmen. Zudem werden ausgewählte Aspekte ihrer Auslandsmobilität thematisiert, wie die Aufenthaltsarten, die Zielregionen und die Einschätzung der beruflichen Zukunft außerhalb Deutschlands. Die Situation der internationalen Promovierenden wird unter Berücksichtigung verschiedener Dimensionen des Promotionsalltags beschrieben, z. B. des unmittelbaren Umfelds der Hochschule (Betreuung und soziale Integration). Außerdem werden ihre Vorstellungen von der beruflichen Karriere nach Abschluss der Promotion beleuchtet
Inhibition of Fibrinolysis by Coagulation Factor XIII
The inhibitory effect of coagulation factor XIII (FXIII) on fibrinolysis has been studied for at least 50 years. Our insight into the underlying mechanisms has improved considerably, aided in particular by the discovery that activated FXIII cross-links α2-antiplasmin (α2AP) to fibrin. In this review, the most important effects of different cross-linking reactions on fibrinolysis are summarized. A distinction is made between fibrin-fibrin cross-links studied in purified systems and fibrin-α2AP cross-links studied in plasma or whole blood systems. While the formation of γ chain dimers in fibrin does not affect clot lysis, the formation of α chain polymers has a weak inhibitory effect. Only strong cross-linking of fibrin, associated with high molecular weight α chain polymers and/or γ chain multimers, results in a moderate inhibition fibrinolysis. The formation of fibrin-α2AP cross-links has only a weak effect on clot lysis, but this effect becomes strong when clot retraction occurs. Under these conditions, FXIII prevents α2AP being expelled from the clot and makes the clot relatively resistant to degradation by plasmin
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