STINHO - micro-a scale measurements and LES modelling

A micrometeorological field experiment within the scope of the STINHO-project (STructure of turbulent transport under INHOmogeneous conditions) was performed at the boundary layer research field of the Lindenberg Meteorological Observatory in the summer of 2002 to investigate the interaction of an inhomogeneously heated surface with the turbulent atmosphere. The data of this field experiment (STINHO-II, July 2002, RAABE ET AL., 2005) were used to initialize a large-eddy simulation model that has been adjusted to the area under investigation. The accuracy of the calculations is supported using analytical models. The LES initialization conditions are adapted to reach an agreement between observed as well as calculated parameters, e.g. the increase of the near surface air temperature or the time dependent rise of the height of the convective boundary layer (CBL) in the first hour after sun rise. A direct comparison between observed and calculated parameters of the CBL-development is possible for averaged data. The detailed spatial and temporal structure of the investigated morning heating process can only be compared using statistical parameter.Im Rahmen des STINHO Projektes (Struktur des turbulenten Transportes über inhomogener Unterlage) wurde im Sommer 2002 auf dem Gelände des Grenzschichtmessfeldes des Meteorologischen Observatoriums Lindenberg ein mikrometeorologisches Feldexperiment durchgeführt, um die Wechselwirkung einer sich heterogen erwärmenden Erdoberfläche mit der turbulenten Atmosphäre zu untersuchen. Die Daten aus einem Experiment (STINHO-II, Juli 2002, RAABE ET AL., 2005) werden zur Initialisierung eines an die Bedingungen des Untersuchungsgebietes angepassten Large-Eddy Simulationsmodells verwendet und mit Beobachtungsdaten verglichen. Die Effizienz der numerischen Simulationen wird durch die Verwendung eines analytischen Modells unterstützt, um eine Konsistenz zwischen Initialisierungsbedingungen und den beobachteten als auch den berechneten Parametern (bodennaher Lufttemperaturanstieg oder die Zunahme der Höhe der konvektiven Grenzschicht) in der ersten Stunde nach Sonnenaufgang herzustellen. Ein Vergleich zwischen beobachteten und berechneten Parametern der konvektiven Grenzschichtentwicklung ist nur für gemittelte Daten möglich. Die räumliche und zeitliche Darstellung der Struktur eines solchen Erwärmungsprozesses kann nur geprüft werden, indem statistische Parameter verwendet werden

Bodengestützte GPS Wasserdampf-Tomographie

Die Signale des Global Positioning Systems (GPS) ermöglichen nicht nur die präzise Positionsbestimmung an jedem Ort der Erde, sondern enthalten auch Informationen über den Wasserdampfgehalt der Atmosphäre. Aus diesen Informationen kann mit Hilfe tomographischer Verfahren die dreidimensionale Wasserdampfverteilung in der Troposphäre rekonstruiert werden. Dabei ist es von besonderem Interesse, wie zuverlässig die Wasserdampfverteilung alleine aus den Daten bodengestützter GPS-Netzwerke, d. h. ohne die Einbeziehung von Low Earth Orbitern (LEOs) oder von Wettersatelliten, bestimmt werden kann. Zu diesem Zweck werden GPS-Daten für unterschiedliche GPS-Netzwerke simuliert und auf ihre Eignung für eine tomographische Rekonstruktion untersucht. Besonders der Zusammenhang zwischen der Anzahl der Satelliten, der Stationsdichte und der in der tomographischen Rekonstruktion erreichbaren Auflösung ist dabei von großer Bedeutung. Aus diesem Grund erfolgt zunächst eine geometrische Bewertung der GPS-Eingangsdaten. Die Rekonstruktion eines 3D-Feldes und die dabei auftretenden Abweichungen zwischen dem originalen und dem rekonstruierten Feld werden abschließend an einem Beispiel dargestellt.The signals of the global positioning system (GPS) can not only be used to obtain the precise position all over the world but carry also information about the water vapour distribution in the atmosphere. This 3D distribution can be reconstructed from the GPS data by means of tomographic techniques. Of special interest is the quality of the reconstructed 3D distribution using data from GPS ground stations alone, without regarding low earth orbiters (LEOs) and weather satellites. Therefore, GPS data have been simulated for different model networks. A subsequent data validation shows the correlation between the number of GPS satellites, the density of ground stations and the spatial resolution of the water vapour field which might be obtained from a tomographic reconstruction. Some selected data sets have been used to reconstruct a given 3D distribution and to analyse variations between the initial model field and the results obtained with different tomographic techniques

Urban Air Mobility Network and Vehicle Type - Modeling and Assessment

This paper describes exploratory modeling of an on-demand urban air mobility (UAM) network and sizing of vehicles to operate within that network. UAM seeks to improve the movement of goods and people around a metropolitan area by utilizing the airspace for transport. Aircraft sizing and overall network performance results are presented that include comparisons of battery-electric and various hybrid-electric vehicles that are fueled with diesel, jet fuel, compressed natural gas, and liquefied natural gas (LNG). Hybrid-electric propulsion systems consisting of internal combustion engine-generators, turbine-generators, and solid oxide fuel cells are explored. Ultimately, the "performance" of the UAM network over a day for each of the different vehicle types, propulsion systems, and stored energy sources is described in four parameters: 1) the average cost per seat-kilometer, which considers the costs of the energy/fuel, vehicle acquisition, insurance, maintenance, pilot, and battery replacement costs, 2) carbon dioxide emission rates associated with vehicle operations, 3) the average passenger wait time, and 4) the average load factor, i.e., the total number of seats filled with paying passengers divided by the total number of available seats. Results indicate that the "dispatch model," which determines when and where aircraft are flown around the UAM network, is critical in determining the overall network performance. This is due to the often-conflicting desires to allow passengers to depart with minimal wait time while still maintaining a high load factor to reduce operating costs. Additionally, regardless of the dispatch model, hybrid-electric aircraft powered by internal combustion engines fueled with diesel or LNG are consistently the lowest cost per seat-kilometer. Battery-electric and future technology LNG/solid oxide fuel cell aircraft produce the lowest emissions (assuming the California grid) with LNG-fueled internal combustion engine-powered hybrids producing only slightly more carbon dioxide

Фискальная деятельность таможенных органов РФ

На таможенные органы Российской Федерации возложено много функций, базовыми из которых являются: регулятивная, контрольная, правоохранительная, но приоритетной по прежнему является фискальная. Значение ее состоит в том, что, посредством взимания таможенными органами таможенных пошлин и налогов, происходит пополнение федерального бюджета. Важное значение бюджета для экономики страны и общественного сектора, в частности, сложно переоценить: государственный бюджет - это основной инструмент государства в централизации и перераспределении валового общественного дохода.The customs authorities of the Russian Federation is vested with a lot of functions, basic of which are: regulatory, Supervisory, law-enforcement, but the priority is still the fiscal. Its significance is that, through the levying of customs authorities of customs duties and taxes, does the replenishment of the Federal budget. The importance of the budget for the country's economy and public sector, in particular, is difficult to overestimate: the state budget is the main tool of the state in the centralization and redistribution of the gross social income

Ubiquitous Computing. Summary

Ubiquitous computing - the complex electronic networking of things that communicate - is considered a promising innovation path worldwide. Intensive R&D activities and political strategies are aimed at promoting practical technologies and applications. Where do we currently stand on the path to the "Internet of Things"? Which practical projects already show the potential that can be exploited by implementing the basic idea of ubiquitous computing? What technical, legal and social challenges must be overcome to achieve this - and what can be the contribution of politics? In the light of these questions, the authors analyse the status quo and the perspectives of ubiquitous computing and illustrate their findings with examples from trade, logistics and health care, among others. the fascinating "Brownie technology" of ubiquitous computing must, however, still be comprehensively made fit by those involved in business, society and politics if its applications are really to become economically attractive, socially acceptable and helpful in overcoming social problems

Applied deep learning in neurosurgery: identifying cerebrospinal fluid (CSF) shunt systems in hydrocephalus patients.

BACKGROUND Over the recent decades, the number of different manufacturers and models of cerebrospinal fluid shunt valves constantly increased. Proper identification of shunt valves on X-ray images is crucial to neurosurgeons and radiologists to derive further details of a specific shunt valve, such as opening pressure settings and MR scanning conditions. The main aim of this study is to evaluate the feasibility of an AI-assisted shunt valve detection system. METHODS The dataset used contains 2070 anonymized images of ten different, commonly used shunt valve types. All images were acquired from skull X-rays or scout CT-images. The images were randomly split into a 80% training and 20% validation set. An implementation in Python with the FastAi library was used to train a convolutional neural network (CNN) using a transfer learning method on a pre-trained model. RESULTS Overall, our model achieved an F1-score of 99% to predict the correct shunt valve model. F1-scores for individual shunt valves ranged from 92% for the Sophysa Sophy Mini SM8 to 100% for several other models. CONCLUSION This technology has the potential to automatically detect different shunt valve models in a fast and precise way and may facilitate the identification of an unknown shunt valve on X-ray or CT scout images. The deep learning model we developed could be integrated into PACS systems or standalone mobile applications to enhance clinical workflows

Strain rate dependency of dislocation plasticity

Dislocation slip is a general deformation mode and governs the strength of metals. Via discrete dislocation dynamics and molecular dynamics simulations, we investigate the strain rate and dislocation density dependence of the strength of bulk copper single crystals using 192 simulations spanning over 10 orders of magnitude in strain rate and 9 orders of magnitude in dislocation density. Based on these large set of simulations and theoretical analysis, a new analytical relationship between material strength, dislocation density, strain rate and dislocation mobility is proposed, which is in excellent agreement with the current simulations as well as with experimental data. The results show that the material strength is a non-monotonic function of dislocation density and displays two universal regimes (first decreasing, then increasing) as the dislocation density increases. The first regime is a result of strain rate hardening, while the second regime is dominated by the classical Taylor forest hardening. Accordingly, the strength displays universally, as a function of strain rate, a rate-independent regime at low strain rates (governed by forest hardening) followed by a rate hardening regime at high strain rates (governed by strain rate hardening). All the results can be captured by a single scaling function. Finally, the fluctuations of dislocation flow are analyzed in terms of the strain rate dependent distribution of dislocation segment velocities. It is found that the fluctuations are governed by another universal scaling function and diverge in the rate independent limit, indicating a critical behavior. The current analysis provides a comprehensive understanding on how collective dislocation motions are governed by the competition between the internal elastic interactions of dislocations, and the stress required to drive dislocation fluxes at a given externally imposed strain rate.Comment: 31 pages, 6 figures, 71 conference

Final results of the DFG funded project “Development of a tomographic water vapour sounding system based on GNSS data”

Since 2008 a group of scientists of the Leipzig Institute of Meteorology (LIM) and the German Research Centre for Geosciences Potsdam (GFZ) develops a method to derive water vapour profiles out of continuously available GNSS data (Global Navigation Satellite System). The aim of this project - supported by the Deutsche Forschungsgemeinschaft (DFG) - was to develop a processing system with related scientific algorithms, which uses data of regional GNSS ground networks to derive 3D water vapour distributions above these stations. This systems use the line of sight water vapour information from each ground station to every GNSS satellite in view (slants) as basis of a 3D tomographic reconstruction. At this time these reconstructions are based on GNSS data of about 330 German or near Germany located groundstations. This leads to a horizontal resolution of the reconstructed 3D water vapour field up to 40km and a vertical resolution of about 0.5km from the upper part of troposphere down to the atmospheric boundary layer (1km height).Seit 2008 befasst sich eine Arbeitsgruppe von Wissenschaftlern am LIM und dem GFZ in Potsdam im Rahmen eines DFG-geförderten Projektes mit der Ableitung von dreidimensionalen Wasserdampfverteilungen in der Atmosphäre aus Beobachtungsdaten regionaler GNSS-Bodennetze (GlobaleNavigationsSatellitenSysteme). Die Wasserdampfverteilungen können aus der atmosphärischen Information entlang der Sichtlinien zwischen den Bodenstationen und den sichtbaren GNSS-Satelliten (sogenannte Slants) berechnet werden. Diese zahlreichen Sichtlinien ermöglichen eine tomographische Verarbeitung der Daten. Der entwickelte tomographische Algorithmus nutzt derzeit bis zu 330 deutsche und nahe Deutschland gelegene GNSS-Stationen, was eine horizontale Auflösung der resultierenden 3D-Felder von 40km und einer vertikalen Auflösung von 0,5km bis hinab zur atmosphärischen Grenzschicht (bis 1 km über dem Boden) ermöglich

Ein Bewertungsverfahren für Schallimmissionen unter Einbeziehung des Atmosphärenzustandes

Es wird ein Verfahren vorgestellt, welches im Rahmen einer Projektbearbeitung für die Bundeswehr entwickelt wurde und die Einbeziehung des meteorologischen Einflusses auf die Schallausbreitung in die Schallimmissionsprognose auf relativ einfache Weise ermöglicht. Zunächst wurden alle denkbaren meteorologischen Situationen (Unterscheidung nach Temperatur, Windgeschwindigkeit und Windrichtung) klassifiziert. Für die verschiedenen Klassen wurden Verteilungen der Schalldruckpegeldämpfung mit dem Schallausbreitungsmodell SMART (Sound Propagation Model for the Atmosphere using Ray Tracing) berechnet. Die Ergebnisse wurden in einer Datenbank zusammengefasst. Die Analyse und Bewertung dieser Prognosen, sowie der Zugriff auf die Datenbank erfolgt über das Visualisierungstool MetaVIS (Meteorological attenuation visualization). Damit ist eine schnelle Schallimmissionsprognose für aktuelle Schallausbreitungssituationen möglich. Im Rahmen dieses Verfahrens ist die Regionalisierung eines Gesamtgebietes in schallklimatologisch ähnliche Teilgebiete möglich. Eine solche Untersuchung erfolgte durch die Analyse von Schalldruckpegeldämpfungskarten für eine Vielzahl von Atmosphärenstrukturen. Im Ergebnis konnte eine Karte zur Neustrukturierung der Beratungsräume der Bundeswehr, unter Berücksichtigung meteorologischer Einflüsse auf die Schallausbreitung, erarbeitet werden.A procedure is described, which has been developed within the framework of a project for the Bundeswehr. This method provides a relatively simple way to include meteorological influences on the sound propagation for forecasting sound immission. Therefore, at first, different meteorological situations (differentiation regarding temperature, wind speed, wind direction) have been classified. For the different classes the spatial distribution attenuation of sound level have been calculated using a model of sound propagation SMART (Sound propagation model of the atmosphere using ray-tracing). The results are stored in a database. The analysis and evaluation of this forecasts as well as the access to the database is realized using the visualization tool MetaVIS (Meteorological attenuation visualization). Therewith fast forecasts of sound immission for present meteorological situations are enabled. Moreover, with this procedure a regionalization of an entire territory in areas with a similar sound climatology is possible. Such an estimation has been done by analysing maps of sound level attenuation for different atmospheric structures. As a result, a map for restructuring the consulting areas of the Bundeswehr, considering meteorological influences on the sound propagation, could be acquired

Development of high temperature refractory-based multi-principle-component alloys by thermodynamic calculations and rapid alloy prototyping

Recently, new refractory-based high entropy alloys (HEAs) have been investigated for potential use as high temperature structural alloys, and some alloys exhibit excellent high temperature strength and ductility. While the high entropy alloy community is generally concerned with obtaining single phase solid-solution phases, secondary strengthening phases are usually required to achieve an adequate balance of mechanical and physical properties for structural applications. This contribution will report on new Mo,Nb-based alloys that have been developed using HEA design guidelines, as well as new tools that enable thermodynamic property predictions and rapid alloy prototyping and assessment. An elemental palette of Mo-Nb-Hf-Ta-Ti-V-W-Zr was chosen in order to promote the formation of a single body-centered cubic (BCC) solid-solution phase upon solidification, which facilitates homogenization heat treatments. Al, Cr, and Si were also included to promote secondary phase formation. These 11 elements were then used to calculate the phases present and their reaction temperatures of 3-, 4-, 5-, and 6-component alloy compositions from all of the available PandatTM databases. Mo and Nb were required to be present in each alloy composition in order to maintain modest alloy costs and densities. Please click Additional Files below to see the full abstract