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1

Zur Frage des Zusammenhanges zwischen Spina bifida occulta und Wirbeltuberkulose  

Microsoft Academic Search

Zusammenfassung Bei 150 an Spondylitis tuberculosa Erkrankten wird an Hand von Röntgenbildern festgestellt, daß weder bei Erwáchsenen noch bei Kindern ein häufigeres Auftreten einer Spina fibida occulta oder anderer Wirbelsäulenvariationen zu finden ist, als dies für wirbelsäulengesunde, sog. normale Menschen in der Literatur beschrieben wurde.

Hanns Lerch

1951-01-01

2

Forensische Bewertung klinischer Todesfälle unter dem Verdacht iatrogener Hyperkaliämie  

Microsoft Academic Search

Zusammenfassung Die forensische Post-mortem-Diagnostik bei Verdacht auf letale Kaliumintoxikationen ist ein ungelöstes Problem, da der Kaliumspiegel bekanntlich in nahezu allen Flüssigkeitskompartimenten nach dem Tod rasch ansteigt. Einerseits ist der Nachweis von Kaliumvergiftungen als vorsätzliches Tötungsmittel zu beurteilen, andererseits kennt die forensische Praxis iatrogene Behandlungsfehler und akzidentelle Fehlinfusionen im Zusammenhang mit der Todesursache Hyperkaliämie. Es werden forensische Aspekte aus 3 klinischen

B. Mahfoud; A. Heinemann; J. Matschke; A. Gehl; F. Schulz; K. Püschel

2003-01-01

3

Zur Reflexion und Transmission elektromagnetischer Wellen bei senkrechtem Einfall auf ebene Grenzflächen zwischen unterschiedlich absorbierenden Medien  

NASA Astrophysics Data System (ADS)

Born und Ladenburg bemerkten bereits 1911, daß bei der Reflexion und Transmission elektromagnetischer Wellen durch eine Grenzfläche zwischen zwei verschieden stark absorbierenden Medien außer den mit den laufenden Wellen verbundenen Poyntingvektoren noch ein zur Erfüllung der Energiebilanz an der Grenzfläche notwendiger, sog. gemischter Poyntingvektor zu beachten ist. Die mit diesem Vektor beschriebene Energieströmung ist stets dorthin gerichtet, wo aus derselben mehr Energie absorbiert wird. Sie entsteht im Zusammenhang mit einer räumlichen Modulation des Energieverbrauchs im partiell stehenden Interferenzfeld der einlaufenden und der reflektierten Welle, wobei die Energieabsorption bei den meisten Substanzen durch das elektrische Feld erfolgt, während das Magnetfeld daran praktisch unbeteiligt ist.Da jedoch die Mitberücksichtigung der magnetischen Effekte zum besseren Verständnis des gemischten Poyntingvektors beitragen kann. wird im folgenden zu ihrer quantitativen Beschreibung in die zweite Maxwellsche Gleichung ein dem Stromglied in der ersten Maxwell-Gleichung analoger Zusatzterm eingeführt. Die Amplitude des gemischten Poyntingvektors erweist sich dann als wesentlich abhängig vom Verhältnis der elektrischen zu den magnetischen Verlusten. Dies wird durch Betrachtung eines Mediums verdeutlicht, in welchem außer den Verlusten durch das elektrische Feld auch hiermit vergleichbare Verluste über das Magnetfeld auftreten, wobei beide Verlustarten zusammen eine an die räumliche Verteilung der Feldenergie besser angepaßte Absorption ergeben. Bei gleichen Energiedichten und Energieverlusten des elektrischen und des magnetischen Feldes verschwindet der gemischte Poyntingvektor.Translated AbstractOn Reflection and Transmission of Electromagnetic Waves Propagating Perpendicular to Plane Surfaces between Different Absorbing MediaBorn and Ladenburg already in 1911 pointed out that to describe reflection and transmission of electromagnetic waves through a plane surface between two different absorbing media in addition to the usual Poynting vectors of the running waves the so called mixed Poynting vector is necessary to maintain the balance of energy on the boundary plane. The flow of energy connected with this vector always points toward the region of maximal wastage of this energy and is closely related to the spatial modulation of the energy consumption within the partially standing interference pattern between the incoming and the reflected wave. In almost all substances the energy absorption is caused by the electric field whereas practically a direct contribution from the magnetic field can be neglected.But taking account of these magnetic effects we may get a better understanding of the mixed Poynting vector. To that end we add to the second of the Maxwell equations a quantity analogous to the electric current term in the first Maxwell equation. The amplitude of the mixed Poynting vector then turns out to depend essentially on the ratio of the energy absorption by the electric and the magnetic field. To confirm this fact we consider a medium, which shows in addition to the usual electric losses also magnetic ones of comparable magnitudes. In such materials the resultant energy consumption is distributed more similar to the spatial distribution of the fieldenergy. As a result the amplitude of the mixed Poynting vector disappears if the percentage of energy absorption by the electric and the magnetic field and their energy densities themselves are made equal to each other.

Richter, G.

4

Kommunikations-TAnDem  

Microsoft Academic Search

Zusammenfassung  Das Trainingsprogramm Kommunikations-TAnDem wurde mit der primren Zielsetzung entwickelt, eine Verbesserung der Kommunikationskompetenz pflegender Angehriger gegenber Demenzpatienten zu erreichen. Sekundre Ziele waren eine Steigerung der Lebensqualitt der Demenzpatienten sowie eine Reduktion der Belastung der Angehrigen in der huslichen Pflege. Die Wirksamkeit des Kommunikations-TAnDems wurde in einer kontrollierten Trainingsstudie mit Wartekontrollgruppendesign und Prozesserhebung berprft, an der eine Stichprobe von 22 pflegenden

J. Haberstroh; K. Neumeyer; B. Schmitz; F. Perels; J. Pantel

2006-01-01

5

Zusammenhang Zwischen Verfestigungs-, Kriech- und Relaxationsverhalten in Cu and al bei Raumtemperatur (Relation Between Strength, Creep and Relaxation Behavior in Cu and Al at Room Temperature).  

National Technical Information Service (NTIS)

Three types of tests are analyzed to study material behavior and to permit its prediction in various conditions of stress and strain. In tensile tests by constant expansion velocity, residual stress and elongation data are obtained. Stress relaxation is d...

B. Nicklas

1987-01-01

6

ASTER DEM performance  

USGS Publications Warehouse

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the National Aeronautics and Space Administration's Terra spacecraft has an along-track stereoscopic capability using its a near-infrared spectral band to acquire the stereo data. ASTER has two telescopes, one for nadir-viewing and another for backward-viewing, with a base-to-height ratio of 0.6. The spatial resolution is 15 m in the horizontal plane. Parameters such as the line-of-sight vectors and the pointing axis were adjusted during the initial operation period to generate Level-1 data products with a high-quality stereo system performance. The evaluation of the digital elevation model (DEM) data was carried out both by Japanese and U.S. science teams separately using different DEM generation software and reference databases. The vertical accuracy of the DEM data generated from the Level-1A data is 20 m with 95% confidence without ground control point (GCP) correction for individual scenes. Geolocation accuracy that is important for the DEM datasets is better than 50 m. This appears to be limited by the spacecraft position accuracy. In addition, a slight increase in accuracy is observed by using GCPs to generate the stereo data. ?? 2005 IEEE.

Fujisada, H.; Bailey, G. B.; Kelly, G. G.; Hara, S.; Abrams, M. J.

2005-01-01

7

Über Zusammenhänge zwischen dem CO 2 Austausch und der Abgabe von Wasserdampf durch Bryophyllum daigremontianum Berg  

Microsoft Academic Search

1.The transpiration in leaves of Bryophyllum daigremontianum exactly follows the changes in consumption of atmospheric carbon dioxide (caused by the Crassulaceen acid metabolism) during the light and dark periods. After removal of the epidermis no distinct rhythm in the course of transpiration can be observed any more, whereas the characteristic CO2 exchange continues in an unchanged matter. For this reason

Manfred Kluge; Karl Fischer

1967-01-01

8

Die Beziehungen zwischen der Trichophyton mentagrophytes-Infektion und dem Haarcyclus beim Meerschweinchen  

Microsoft Academic Search

Unter Ausnutzung des Phänomens der physiologischen temporären Synchronisation des primär unsynchronisierten Haarcyclus wird am Meerschweinchen die Abhängigkeit des Verlaufes der Trichophyton mentagrophytes-Infektion von der Haarcyclusphase während der Infektion gezeigt.

K. Bosse; L. Krempl-Lamprecht; Z. Burzynski; W. Kostanecki

1964-01-01

9

Der long-acting thyroid stimulator (LATS) bei unbehandelten und 131 J-therapierten Hyperthyreosen, nach totaler Thyreoidektomie, sowie seine Beziehung zu den Schilddrüsenantikörpern  

Microsoft Academic Search

Zusammenfassung Die Ergebnisse von LATS-Bestimmungen bei131J-therapierten und nicht131J-behandelten Hyperthyreosen ergab keine Korrelation zwischen131J-Therapie und dem Auftreten von long-acting thyroid stimulator. Auch bei Verlaufskontrollen vor und nach131J-Therapie konnte kein Zusammenhang festgestellt werden. Dagegen fand sich erneut eine eindeutige Beziehung zwischen dem Auftreten von LATS und dem der Schilddrüsenantikörper. Nach totaler Thyreoidektomie sinkt LATS deutlich ab.

A. Ziemke; L. Weisbecker; H. Uthgenannt; K. Schemmel; W. Müller; H. Heesen; W. Eickenbusch

1968-01-01

10

Über Wechselbeziehungen zwischen Schilddrüse und Nebennierenrinde  

Microsoft Academic Search

Methylthiouracil führt zur Atrophie der Zona fasciculata und zu regressiven Veränderungen des äußeren Transformationsfeldes der Nebennierenrinde. Es verhindert ihre kompensatorische Hypertrophie nach halbseitiger Adrenalektomie. Jod verändert die Nebennierenrinde ähnlich dem Thyroxin in Richtung der progressiven Transformation. Eine thyreotrope Funktionssteigerung des Hypophysenvorderlappens hat eine verminderte Abgabe corticotropen Hormons zur Folge. Die Bremsung der TSH-Ausschüttung bedingt eine gesteigerte corticotrope Partialfunktion des Hypophysenvorderlappens.

Joachim Kracht; Mechthild Spaethe

1953-01-01

11

Zusammenhang von Quantitativer Sensorischer Testung und Fragebögen zu neuropathischen Schmerzen am Beispiel chronischer Ischämieschmerzen bei PAVK  

Microsoft Academic Search

Zusammenfassung\\u000a Hintergrund  Eine neuropathische Komponente chronisch ischämischer Schmerzen bei peripherer arterieller Verschlusskrankheit (PAVK) konnte\\u000a bereits mittels Quantitativer Sensorischer Testung (QST) und Fragebögen gezeigt werden. Ziel dieser Arbeit ist es, Zusammenhänge\\u000a zwischen Schmerzfragebögen und QST bei Patienten mit chronischen Ischämieschmerzen zu untersuchen.\\u000a \\u000a \\u000a \\u000a Methoden  Zehn Patienten mit schwerer PAVK ohne begleitenden Diabetes mellitus füllten einen standardisierten Fragebogen aus und wurden\\u000a mittels QST untersucht. Der

P. M. Lang; L. J. Rüger; T. Abahji; U. Hoffmann; A. Crispin; D. Irnich

2009-01-01

12

Untersuchungen zur genetischen Transformation zwischen Agrobacterium tumefaciens und Rhizobium spec  

Microsoft Academic Search

Vergleichende Untersuchungen an den Partnern einer genetischen Transformation zwischen Agrobacterium tumefaciens (Donator) und Rhizobium leguminosarum (Acceptor) sowie einem hieraus hervorgegangenen virulenten Transformanten ergeben klare serologische und morphologische Unterschiede. Es wird gezeigt, daß der transformierte Stamm nicht nur die Fähigkeit zur Tumorinduktion an Pflanzen erlangt hat, sondern auch in einigen physiologischen und biochemischen Eigenschaften so verändert wurde, daß er zwischen denen

Hartmut Kern

1965-01-01

13

Der Küstenschelf von El Salvador im Zusammenhang mit der Morphologie und Geologie des Festlandes  

Microsoft Academic Search

Morphologie und Geologie El Salvadors sind besonders durch Vulkanismus und Verwerfungen charakterisiert. Die jungen und alten Vulkane sind in ihrer Lage durch tektonische Leitlinien bestimmt. An dem parallelogrammförmigen Gitternetz der tektonischen Leitlinien wird eine Anzahl von Bruchschollen deutlich, auf deren Bestehen schon K. Sapper hinwies. Auf einer vom Verfasser angefertigten Tiefenkarte (Tafel 8) ist die pazifische Saumtiefe des Guatemala-Grabens herausgearbeitet.

H. G. Gierloff-Emden

1958-01-01

14

Über die Wechselwirkung zwischen Polyvinylazetat und Weichmachern  

Microsoft Academic Search

Zusammenfassung  In der vorliegenden Abhandlung wird an 11 verschiedenen Polyvinylacetat\\/Weichmacher-Systemen auf Grund dielektrischer Messungen\\u000a die kritische Weichmacherkonzentration bestimmt, bei der gerade das Auftreten eines sekundren, dem nicht als Solvat gebundenen\\u000a Weichmacher zugehrigen tg?-Maximums zu erkennen ist. Die ermittelten molaren Konzentrationen PVAz\\/Weichmacher variieren innerhalb derselben Grenzen,\\u000a die wir schon frher fr PVC\\/Weichmacher gefunden hatten. Diese Beobachtung gibt Anla\\\\ zu der Frage, ob

A. Hartmann

1957-01-01

15

DEMs for EIS and AIA  

NASA Astrophysics Data System (ADS)

We present a method for constructing Differential Emission Measures (DEMs) using data from solar imagers such as EIS and AIA. The method is simple, and very fast (˜ 1 minute per full disk AIA image). We analyze the fidelity of the method, and apply it to a coronal loop observed on April 19, 2011. The method appears to give reasonable results, although reconstructed DEMs can contain regions of moderately negative emission measure (EM). Both EIS and AIA DEM reconstructions suggest that the loop has a narrow temperature distribution centered at 1.2 MK, situated in a diffuse background of broader temperature distribution centered at 3 MK.

Plowman, J.; Kankelborg, C.; Martens, P.; Ritchie, M.; Scott, J.; Sharma, R.

2012-05-01

16

Über Oxy-Ephedrine  

Microsoft Academic Search

Zusammenfassung 1.Es wird an Hand der Oxy-Ephedrine der Zusammenhang zwischen Konstitution und Wirkung in der Reihe Ephedrin — Suprarenin besprochen.2.Auf Grund der Versuchsergebnisse wird der Unterschied zwischen „sympathomimetischen und sympathikotropen” Stoffen betont.3.Die Mono-oxy-Ephedrine bilden einen Übergang von dem nur sympathomimetisch (muskulotrop) wirkenden Ephedrin zu dem rein sympathikotropen (neurotropen) Suprarenin.4.Die Stellungen der OH-Gruppen sind untereinander nicht gleichwertig; die Suprareninähnlichkeit nimmt in

O. Schaumann

1931-01-01

17

Análisis Interferométrico de las Burbujas DEM 164; DEM 165; DEM 202-207; DEM 208; y DEM 221 en la Nube Mayor de Magallanes  

NASA Astrophysics Data System (ADS)

In this contribution we present the analysis of observations made with a Fabry-Perot interferometer of the possible HII supergiant shell LMC9 (Meaburn 1980) located in the Large Magellanic Cloud. The data cube came from Ha observations carried out by LeCoarer and Goldes from the ESO in Chile, us- ing a Cigale-type instrument (Boulesteix et al. 1984). On this shell there are superposed the nebular complexes DEM 208, DEM 221, DEM 164, DEM 165, DEM 202, DEM 206 and DEM 207 (Davies et al. 1976). They were investigated with the intension of establishing their general kinematics and morphologic characteristics and also analyze the possible association with a major structure, all with the aim to contribute to a detail global kinematics image of LMC. Another objective of this studies is to try to elucidate if the objects analyzed have cinematically any identity as a group, or if they are relatively isolated on the diffuse background to which, in our opinion, they belonged to. FULL TEXT IN SPANISH

Oddone, M. A.; Laval, A.; Lecoarer, E.; Goldes, G.; Carranza, G.

18

QT dispersion in patients with pulmonary embolism  

Microsoft Academic Search

\\u000a Zusammenfassung  HINTERGRUND: Verschiedene EKG Veränderungen sind mit der akuten Pulmonal-Embolie in Zusammenhang gebracht worden. Bezüglich\\u000a möglicher Veränderungen des QT-Intervalls liegen allerdings keine Daten vor. Das Ziel unserer Studie war es, zu prüfen, ob\\u000a es einen Zusammenhang zwischen Veränderungen des QT Intervalls und dem Schweregrad der Pulmonalembolie gibt. METHODEN: 129\\u000a Patienten mit Pulmonalembolie (mittleres Alter 58 ± 16.5 Jahre) mit einem EKG

Necip Erm?s; Hilal Erm?s; Nazan Sen; Alper Kepez; Bilal Cuglan

2010-01-01

19

Wiederbeginn nach dem Zweiten Weltkrieg  

NASA Astrophysics Data System (ADS)

Dieses Kapitel schildert zunächst die Ausgangslage für die Statistik in Deutschland nach dem Zweiten Weltkrieg: Der statistische Dienst in den Besatzungszonen musste teilweise erst aufgebaut und der statistische Unterricht an den Hochschulen wieder in Gang gebracht werden. In dieser Lage ergriff der Präsident des Bayerischen Statistischen Landesamtes, Karl Wagner, tatkräftig unterstützt von Gerhard Fürst, dem späteren Präsidenten des Statistischen Bundesamtes, die Initiative zur Neugründung der Deutschen Statistischen Gesellschaft (DStatG). Die Gründungsversammlung 1948 im München wurde zu einem Meilenstein in der Geschichte der DStatG. Ziel war es, alle Statistiker zur Zusammenarbeit anzuregen, ihre Qualifikation an das internationale Niveau heranzuführen und die Anwendung neuerer statistischer Methoden in der Praxis zu fördern. Es folgten 24 Jahre fruchtbarer Arbeit unter Karl Wagner (1948-1960) und Gerhard Fürst (1960-1972). Der Beitrag skizziert die Statistischen Wochen, die Tätigkeit der Ausschüsse und die Veröffentlichungen in dieser Zeit.

Strecker, Heinrich; Bassenge-Strecker, Rosemarie

20

Untersuchungen zur genetischen Transformation zwischen Agrobacterium tumefaciens und Rhizobium spec  

Microsoft Academic Search

In Ergänzung zu den Untersuchungen an den Partnern einer genetischen Transformation zwischen Agrobacterium tumefaciens (Donator) und Rhizobium leguminosarum (Acceptor) und einem hierdurch entstandenen Transformanten werden vergleichende Analysen an entsprechenden DNA-Präparaten durchgeführt. Bei gleichen physikalischen Eigenschaften und ähnlicher chemischer Zusammensetzung sind geringe Differenzen im Basengehalt der einzelnen Präparate festzustellen. Säulenchromatographische Fraktionierungen der basisch hydrolysierten Apyrimidinsäuren ergenben keine spezifischen Unterschiede in der

Hartmut Kern

1965-01-01

21

DEM extraction from stereo SAR satellite imagery  

Microsoft Academic Search

Automatic Digital Elevation Model (DEM) extraction from stereo SAR satellite images continues to be a challenge. The main difficulty is in obtaining the largest possible number of correct matches, at the same time minimizing the number of false matches and other artifacts and distortions in the derived DEMs. For accepted matches, the highest possible geometric accuracy is desired. This paper

J. A. Ostrowski; Philip Cheng

2000-01-01

22

DEM simulation of oblique boudinage  

NASA Astrophysics Data System (ADS)

Boudinage occurs in mechanically layered rocks if there is a component of lengthening parallel to a brittle layer in a ductile matrix. Asymmetric boudin structures develop if the extension is not layer-parallel, and the boudin blocks rotate. The amount of block rotation is commonly used as shear indicators; therefore, it has been well studied. However, full oblique boudinage has not been modeled yet. We simulated full boudinage processes during layer oblique extension using DEM simulation software. In our boudinage model, the initial setup consists of three layers: there is a brittle center oblique layer in a ductile matrix. We simulated horizontal extension by applying vertical displacement: the top and bottom boundaries of the model are moved at a constant velocity, while the side boundaries were force controlled by applying a constant confining force. By varying the cohesion of the competent layer, various type and shape of boudin blocks were developed. By varying the angle of the competent layer, the rotation of the boudin blocks changed. With higher dip of the competent layer, the rotation of the boudin blocks is more consistent. We also studied the stress field during the simulation. The results show, that in case of ductile material, the disruptions of the layer are driven by the angle of the layer and not the orientation of the external stress field.

Komoroczi, Andrea; Abe, Steffen; Urai, Janos L.

2013-04-01

23

Urban DEM generation, analysis and enhancements using TanDEM-X  

NASA Astrophysics Data System (ADS)

This paper analyzes the potential of the TanDEM-X mission for the generation of urban Digital Elevation Models (DEMs). The high resolution of the sensors and the absence of temporal decorrelation are exploited. The interferometric chain and the problems encountered for correct mapping of urban areas are analyzed first. The operational Integrated TanDEM-X Processor (ITP) algorithms are taken as reference. The ITP main product is called the raw DEM. Whereas the ITP coregistration stage is demonstrated to be robust enough, large improvements in the raw DEM such as fewer percentages of phase unwrapping errors, can be obtained by using adaptive fringe filters instead of the conventional ones in the interferogram generation stage. The shape of the raw DEM in the layover area is also shown and determined to be regular for buildings with vertical walls. Generally, in the presence of layover, the raw DEM exhibits a height ramp, resulting in a height underestimation for the affected structure. Examples provided confirm the theoretical background. The focus is centered on high resolution DEMs produced using spotlight acquisitions. In particular, a raw DEM over Berlin (Germany) with a 2.5 m raster is generated and validated. For this purpose, ITP is modified in its interferogram generation stage by adopting the Intensity Driven Adaptive Neighbourhood (IDAN) algorithm. The height Root Mean Square Error (RMSE) between the raw DEM and a reference is about 8 m for the two classes defining the urban DEM: structures and non-structures. The result can be further improved for the structure class using a DEM generated with Persistent Scatterer Interferometry. A DEM fusion is thus proposed and a drop of about 20% in the RMSE is reported.

Rossi, Cristian; Gernhardt, Stefan

2013-11-01

24

The Future of DEMs for Tsunami Modeling  

NASA Astrophysics Data System (ADS)

Digital elevation models are the foundation upon which tsunami wave modeling operates. As input to modeling of tsunami wave propagation across ocean basins and inundation of coastal communities, they are presumed to perfectly represent Earth’s solid surface. In practice, they approximate Earth to some degree and errors in the DEMs may affect the accuracy of tsunami modeling results. We present some of the challenges faced in developing accurate coastal DEMs, improvements made over the past few years, and ways in the future to minimize their error contribution to tsunami modeling. Perspective view of the 1 arc-second King Cove, Alaska DEM.

Eakins, B.; Taylor, L. A.

2009-12-01

25

Creating improved ASTER DEMs over glacierized terrain  

NASA Astrophysics Data System (ADS)

Digital elevation models (DEMs) produced from ASTER stereo imagery over glacierized terrain frequently contain data voids, which some software packages fill by interpolation. Even when interpolation is applied, the results are often not accurate enough for studies of glacier thickness changes. DEMs are created by automatic cross-correlation between the image pairs, and rely on spatial variability in the digital number (DN) values for this process. Voids occur in radiometrically homogeneous regions, such as glacier accumulation areas covered with uniform snow, due to lack of correlation. The same property that leads to lack of correlation makes possible the derivation of elevation information from photoclinometry, also known as shape-from-shading. We demonstrate a technique to produce improved DEMs from ASTER data by combining the results from conventional cross-correlation DEM-generation software with elevation information produced from shape-from-shading in the accumulation areas of glacierized terrain. The resulting DEMs incorporate more information from the imagery, and the filled voids more accurately represent the glacier surface. This will allow for more accurate determination of glacier hypsometry and thickness changes, leading to better predictions of response to climate change.

Raup, B. H.; Khalsa, S. S.; Armstrong, R.

2006-12-01

26

Einzelmolekül-Elektronik Transistoren aus dem Reagenzglas  

NASA Astrophysics Data System (ADS)

Elektronische Bauteile aus einzelnen Molekülen herzustellen, ist ein Traum der Physiker (Physik in unserer Zeit 2003, 34 (6), 272). Vielleicht könnte der polyzyklische Kohlenwasserstoff Hexabenozocoronen (HBC) ein Stück weiter helfen. Ein Team um Frank Jäckel und Jürgen Rabe an der Berliner Humboldt-Universität hat zusammen mit Kollegen des Max-Planck-Instituts für Polymerforschung in Mainz aus dem bräunlichen Stoff Transistoren gemixt, die gerade mal ein Molekül groß sind [1].

Loos, Andreas

2004-07-01

27

DEM-based Analysis of Local Relief  

Microsoft Academic Search

Local relief (LR) mainly describes the complexity of the Earth’s surface at large spatial scales and reflects the degree to\\u000a which the Earth’s surface is incised by exogenic agents. This chapter probes the methodology of extracting LR from a 1-km\\u000a DEM and discusses the large-scale geomorphological characteristics of China. It proves that the optimum unit for measuring\\u000a LR is 42.25km2.

LIU Aili

28

DEM from Cartosat data and comparison to DEM from other sources  

NASA Astrophysics Data System (ADS)

Until a few years ago DEMs were used only by specialized scientists for terrain analysis, product development and decision making and by the army for military operations planning. Recently the DEM are used in a variety of both commercial and public business and management fields within telecommunications, navigation, constructions, energy, disaster management, transportation, weather forecast, remote sensing, geology, land cover classification, civil engineering and many more. All these applications could be summarised in four major categories: Commercial applications, Industrial applications, Military applications and Environmental-Ecological applications. Thus, there is a huge pressure for very accurate elevation data covering the entire planet surface. Image stereopairs form satellite sensors seem to provide a quite accurate and cost affordable source of elevation data. One of the newest satellite sensors with stereo collection capability is Cartosat. It can acquire stereopairs along the track with a 2,5m spatial resolution covering areas of 30X30km. In this study we compare a DEM created from a Cartosat stereopair to DEM created from other elevation data sources: 1/50.000 topographic maps, SRTM data, airphotos stereo-pair. The area of study is situated in Chalkidiki Peninsula, Greece. After a first control for random or systematic errors a statistical analysis was done. Points of known elevation have been used to estimate the accuracy of these three DEMs. The elevation difference between the different DEMs was calculated. Elevation profiles and derived maps (slope and aspect) were created and compared. 2D RMSE, correlation and the percentile value were also computed and the results are presented.

Tsombos, Panagiotis I.; Nikolakopoulos, Konstantinos G.; Lathourakis, Georgios

2008-10-01

29

Evaluation of DEM-assisted SAR coregistration  

NASA Astrophysics Data System (ADS)

Image alignment is without doubt the most crucial step in SAR Interferometry. Interferogram formation requires images to be coregistered with an accuracy of better than 1/8 pixel to avoid significant loss of phase coherence. Conventional interferometric precise coregistration methods for full-resolution SAR data (Single-Look Complex imagery, or SLC) are based on the cross-correlation of the SLC data, either in the original complex form or as squared amplitudes. Offset vectors in slant range and azimuth directions are computed on a large number of windows, according to the estimated correlation peaks. Then, a two-dimensional polynomial of a certain degree is usually chosen as warp function and the polynomial parameters are estimated through LMS fit from the shifts measured on the image windows. In case of rough topography and long baselines, the polynomial approximation for the warp function becomes inaccurate, leading to local misregistrations. Moreover, these effects increase with the spatial resolution and then with the sampling frequency of the sensor, as first results on TerraSAR-X interferometry confirm. An improved, DEM-assisted image coregistration procedure can be adopted for providing higher-order prediction of the offset vectors. Instead of estimating the shifts on a limited number of patches and using a polynomial approximation for the transformation, this approach computes pixel by pixel the correspondence between master and slave by using the orbital data and a reference DEM. This study assesses the performance of this approach with respect to the standard procedure. In particular, both analytical relationships and simulations will evaluate the impact of the finite vertical accuracy of the DEM on the final coregistration precision for different radar postings and relative positions of satellites. The two approaches are compared by processing real data at different carrier frequencies and using the interferometric coherence as quality figure.

Nitti, D. O.; Hanssen, R. F.; Refice, A.; Bovenga, F.; Milillo, G.; Nutricato, R.

2008-10-01

30

DEM simulation of experimental dense granular packing  

NASA Astrophysics Data System (ADS)

In this study we present numerical analysis performed on the experimental results of sphere packings of mono-sized hard sphere whose packing fraction spans across a wide range of 0.59DEM) and the experimental results from XCT, we investigate how the intergranular forces change with the onset of crystallization.

Hanifpour, Maryam; Francois, Nicolas; Allaei, Mehdi Vaez; Saadatfar, Mohammad

2013-06-01

31

Comparison of DEMs from Terrain Mapping Camera Images with LOLA  

NASA Astrophysics Data System (ADS)

DEMs generated from the TMC camera are compared with LDEM-256. TMC DEMs are of high quality and accurate, which enables the contruction of three-dimensional models. They are representative of the stability of the platform and the potential of CH-1 for accurate lunar referencing.

Krishna Sumanth, T.; Nagasubramanian, V.; Radhadevi, P. V.; Sudheer Reddy, D.; Solanki, S. S.; Jyothi, M. V.; Saibaba, J.; Varadan, G.

2012-03-01

32

Greenland 5 km DEM, Ice Thickness, and Bedrock Elevation Grids  

NSDL National Science Digital Library

The National Snow and Ice Data Center (NSIDC) has recently released a digital elevation model (DEM), ice thickness data taken by airborne ice penetrating radar, and bedrock thickness data (ice thickness subtracted from DEM) for 5 km of Greenland. The data are in ASCII format, and documentation (data collection, application, terminology, etc.) is available at the site.

2001-01-01

33

DIGITAL ELEVATION MODEL (DEM) FILES (30 M) FOR VIRGINIA  

EPA Science Inventory

Digital Elevation Model (DEM) files, 30-m resolution, for Virginia from US Geological Survey Web site: http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/7_min_dem/states/VA.html Files listed for VA but centered in TN, WV, and NC are not included. All file archives were downloaded an...

34

InSAR DEM error modeling and calibration  

NASA Astrophysics Data System (ADS)

This paper provides a error modeling and calibration method to the geolocation error problem arising in the generation of digital elevation model (DEM) via interferometric synthetic aperture radar (InSAR) technique. DEM error is divided into two parts, systematic error and random error, they are modeled respectively. The baseline error is of crucial importance in the systematic error, it causes a slowly changed height error in the azimuth and a small tilt in the ground range of the DEM, a 2-D polynomial function is used to fit the systematic height error. The corrected DEM is obtained by removing the systematic error from the raw DEM. Computer simulation results prove the availability of the method.

Zhang, Yong-Jun; Huang, Hai-Feng; Zhang, Yong-Sheng; Liang, Dian-Nong

2011-10-01

35

DEM Simulation of Clay Smear along Faults  

NASA Astrophysics Data System (ADS)

The smearing of clay is an important sealing mechanism in fault zones of sand-clay sequences. One process which can strongly influence the thickness and therfore sealing capacity of clay smears is the mixing between sand and clay. This process has been discussed in the literature and was identified in laboratory experiments, but its rate as a function of sand and clay properties, pressure and shear strain is poorly understood. In this work a Discrete Element (DEM) simulation is used to investigate influence of geometrical and material parameters on the mixing between sand and clay during shear of a layered sequence and therefore the properties of the resulting clay smear. While the sand is modelled at the grain scale, this can not be done for the clay due to the large difference in scale. Therefore the model only attempts to reproduce the micro-mechanical processes at the scale of the sand grains whereas for the clay only the bulk properties are matched. The simulation model consists of a 2D box containg layers of sand and clay which are represented by DEM particles with different size and frictional properties. On the boundaries orthogonal to the layering a constant normal stress is applied. The model is then sheared perpendicular to the orientation of the layers by moving the edges of the model with a constant velocity. We have investigated both models with and without periodic boundary conditions in the direction of shear. The models with periodic boundary conditions are representative of fault zones in a sand-clay sequence with periodic layering whereas the models without periodic boundary conditions are representative of fault zones across a single clay layer or a group of clay layers embedded in a sand matrix. A sufficiently large contrast in the frictional properties between the sand and the clay has been obtained by using different grain shapes for the sand layers. The results show the development of structures in the mixing zone between sand and clay layers which are comparable to those observed in laboratory experiments. In particular, a thickening of the mixed layer with increasing strain is observed. In nature, this will produce a thicker clay-rich gouge than expected from simple shearing the separate clay and sand layers, and to a stabiliization of shear because softening is less pronounced in a mixture.

Abe, S.; Urai, J. L.; Schmatz, J.

2009-04-01

36

The generation of DEM from ALOS in the Himalayas  

NASA Astrophysics Data System (ADS)

Glacier volume changes needs an integrated study and correction on generated DEMs from multi-sources remote sensing data and evaluation of the vertical errors and accuracy. Here, we produced DEMs over mountain glaciers from ASTER and ALOS/PRISM on the northern slope of Mt. Qomolangma (hereafter called the Mt. Qomolangma region), also known as the Mt. Everest, located in the middle Himalayan Mountains. A series of digital images, include Aster images on 23 Oct 2003, 3 scenes of ALOS/PRISM on 04 Dec 2006, 1:50,000 topographic maps with contour interval of 20 m produced from aerial photographs acquired in 1974 and the 1:50,000 DEM (cell size: 25 m) generated from the topographic maps were used.The DEM was generated based on the three scenes from ALOS/PRISM images and PCI Orthoengine module. The process of DEM generation from ASTER images is very similar to that of ALOS/PRISM. The difference is that: only two images ASTER from nadir and backward views were used here. Compared various kinds of products of the generated DEMs in the non-glacierized area with the 1:50,000 topographic maps using 215 random points, we found that the mean difference of PRISM DEM to the topographic maps is 1.7 m. However, the mean difference of ASTER GDEM (ASTER_GDEM) is 45m, which is the released Version 1 of the ASTER Global DEM on 29 June, 2009. Our result shows that the quality of ALOS/PRISM DEM is better than that of ASTER GDEM.

Ye, Q.

2009-12-01

37

Neuroökonomie und Neuromarketing — Erkenntnisse der Gehirnforschung für die Gestaltung von Beziehungen zwischen Kunden und Unternehmen  

Microsoft Academic Search

Innerhalb der letzten Jahre hat die Beachtung von Ergebnissen der Neuroökonomie und des Neuromarketing sowohl in der Wissenschaft\\u000a als auch in der Praxis deutlich zugenommen. Im Rahmen der Neuroökonomie werden ökonomische Fragestellungen mit neurowissenschaftlichen Erkenntnissen und Methoden analysiert (vgl. Hain\\/ Kenning\\/\\u000a Lehmann-Waffenschmidt 2007). Der Schwerpunkt der Forschung liegt vor allem darauf, zu ergründen, wie im Gehirn zwischen Verhaltensalternativen\\u000a gewählt wird.

Christian Duchmann; Armin Töpfer

38

Optical DEM generation: satellites help preserve Przewalski's horse  

Microsoft Academic Search

Privateers NV generated a DEM from optical LANDSAT TM and Spot images as first layer for the GIS system that is used in the Hustain Nuruu national park in Mongolia by the re- introduction program of the Przewalski horse.

Paul ROMEIJN; Edmond NEZRY; Pierre TRAHAN; Iwan SUPIT

39

DEM Reconstruction: A Markov-Chain Monte-Carlo Approach  

NASA Astrophysics Data System (ADS)

We describe a Markov-Chain Monte-Carlo process using a Metropolis algorithm to derive Differential Emission Measures (DEMs) and element abundances from EUV line fluxes. This technique allows us to relax the smoothness constraint generally imposed on DEMs and also to determine confidence bounds on the computed values. We apply this method to solar spectral line data from SERTS (Solar EUV Rocket Telescope and Spectrograph).

Kashyap, Vinay; Drake, Jeremy

40

Coherence evaluation of TanDEM-X interferometric data  

NASA Astrophysics Data System (ADS)

The TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) mission comprises two nearly identical satellites: TerraSAR-X (TSX, launched in 2007), and TanDEM-X (TDX, launched in June 2010). The primary objective of the mission is to generate a worldwide and consistent digital elevation model (DEM) with an unprecedented accuracy. During the first 3 months after its launch, the TDX satellite was tested and calibrated in monostatic configuration with both satellites flying in 20 km along-track distance, and it was proven that the system and acquisition performance is almost identical to TSX. Both satellites were then brought into close formation of a few hundred meters distance to begin the bistatic commissioning phase. Since then, TSX and TDX have acted as a large single-pass radar interferometer, which overcomes the limitations imposed by repeat-pass interferometry and allow the acquisition of highly accurate cross- and along-track interferograms. In December 2010, TanDEM-X began with operational global acquisition: bistatic and monostatic SAR images are simultaneously acquired in stripmap mode and processed to interferograms, from which a global DEM is derived. The key parameter in estimating interferometric performance is the coherence, which is deeply evaluated in this paper. The impact of different decorrelation sources as well as the performance stability over time is investigated by means of statistical analyses and dedicated acquisitions on defined test sites, demonstrating the outstanding interferometric capabilities of the TanDEM-X mission.

Martone, Michele; Bräutigam, Benjamin; Rizzoli, Paola; Gonzalez, Carolina; Bachmann, Markus; Krieger, Gerhard

2012-09-01

41

Novel application of DEM to modelling comminution processes  

NASA Astrophysics Data System (ADS)

Comminution processes in which grains are broken down into smaller and smaller sizes represent a critical component in many industries including mineral processing, cement production, food processing and pharmaceuticals. We present a novel DEM implementation capable of realistically modelling such comminution processes. This extends on a previous implementation of DEM particle breakage that utilized spherical particles. Our new extension uses super-quadric particles, where daughter fragments with realistic size and shape distributions are packed inside a bounding parent super-quadric. We demonstrate the flexibility of our approach in different particle breakage scenarios and examine the effect of the chosen minimum resolved particle size. This incorporation of the effect of particle shape in the breakage process allows for more realistic DEM simulations to be performed, that can provide additional fundamental insights into comminution processes and into the behaviour of individual pieces of industrial machinery.

Delaney, Gary W.; Cleary, Paul W.; Sinnott, Matt D.; Morrison, Rob D.

2010-06-01

42

Zwischen Neugier und Angst Emotionen und sexuelles Risikoverhalten von Mädchen beim ersten Mal  

Microsoft Academic Search

Zusammenfassung: Jugendliche zeigen riskantes Gesundheitsverhalten als Strategie zur Bewältigung von Entwicklungsaufgaben (Pinquart & Silbereisen, 2004). Sozialkognitive Mo- delle zur Erklärung und Prädiktion von Gesundheitsverhalten betrachten menschliches Ver- halten als Resultat vernunftgesteuerter Prozesse, vernachlässigen allerdings emotionale Faktoren (Pant, 2003). Die vorliegende Studie exploriert Emotionen vor, während und nach dem ersten Geschlechtsverkehr und deren Rolle bei STDs-präventivem Verhalten. 32 Mäd- chen (x

Olivia Kada; Eva Brunner

43

Diskutieren in der frühen Bundesrepublik: zur Kulturgeschichte des besseren Arguments zwischen Reeducation und Studentenbewegung  

Microsoft Academic Search

Das Paper untersucht die frühe Bundesrepublik in kommunikationsgeschichtlicher Perspektive und historisiert Annahmen über dialogisch-rationale Kommunikation, die dem Konzept der Zivilgesellschaft als normative Prämisse eingeschrieben sind. Ausgehend von der westdeutschen Studentenbewegung der sechziger Jahre wird argumentiert, daß das alltägliche Vertrauen in die Gesprächsform „Diskussion“ als vermeintlich dialogisch-rationaler Handlungsmodus historisch variabel ist und sich die Praxis alltäglichen „Diskutierens“ im Spannungsfeld von überhöhten

Nina Verheyen

2003-01-01

44

Precise baseline determination for the TanDEM-X mission  

NASA Astrophysics Data System (ADS)

The TanDEM-X mission will strive for generating a global precise Digital Elevation Model (DEM) by way of bi-static SAR in a close formation of the TerraSAR-X satellite, already launched on June 15, 2007, and the TanDEM-X satellite to be launched in May 2010. Both satellites carry the Tracking, Occultation and Ranging (TOR) payload supplied by the GFZ German Research Centre for Geosciences. The TOR consists of a high-precision dual-frequency GPS receiver, called Integrated GPS Occultation Receiver (IGOR), and a Laser retro-reflector (LRR) for precise orbit determination (POD) and atmospheric sounding. The IGOR is of vital importance for the TanDEM-X mission objectives as the millimeter level determination of the baseline or distance between the two spacecrafts is needed to derive meter level accurate DEMs. Within the TanDEM-X ground segment GFZ is responsible for the operational provision of precise baselines. For this GFZ uses two software chains, first its Earth Parameter and Orbit System (EPOS) software and second the BERNESE software, for backup purposes and quality control. In a concerted effort also the German Aerospace Center (DLR) generates precise baselines independently with a dedicated Kalman filter approach realized in its FRNS software. By the example of GRACE the generation of baselines with millimeter accuracy from on-board GPS data can be validated directly by way of comparing them to the intersatellite K-band range measurements. The K-band ranges are accurate down to the micrometer-level and therefore may be considered as truth. Both TanDEM-X baseline providers are able to generate GRACE baselines with sub-millimeter accuracy. By merging the independent baselines by GFZ and DLR, the accuracy can even be increased. The K-band validation however covers solely the along-track component as the K-band data measure just the distance between the two GRACE satellites. In addition they inhibit an un-known bias which must be modelled in the comparison, so the differences between the computed baselines and the K-band ranges vary around a mean. In the end a systematic deviation or bias cannot be detected this way. A 3-D assessment of the baseline accuracies including biases can be gained by comparison of independently derived baselines as here from GFZ and DLR. Indeed it turns out that the different baselines show systematic differences of a few millimeters. From this it can be concluded that for the TanDEM-X mission an unknown bias in the baselines is possible which in turn would hurt the anticipated DEM accuracy limit. In order to control a possible baseline bias, a calibration chain via SAR calibration data takes has been invented in the TanDEM-X ground segment. This chain delivers corrections to the baseline bias so that unbiased baselines with sub-millimeter accuracies can be provided to secure the DEM accuracy requirement.

Koenig, Rolf; Moon, Yongjin; Neumayer, Hans; Wermuth, Martin; Montenbruck, Oliver; Jäggi, Adrian

45

Removing non-ground points from automated photo-based DEM and evaluation of its accuracy with LiDAR DEM  

NASA Astrophysics Data System (ADS)

Three sets of DEM, including LiDAR, stereo photo based DEM, and contour-based DEM, were created using different tools and sources. Because different tools produce different raster data sets, they were reprojected into the same coordinate system and converted to point clouds as vector format, then a triangulated irregular network (TIN) retaining all grid or mass points was created from each point coverage. Corresponding orthophoto involved in extracting stereo photo DEM, classified by object-oriented approach to create vector polygons representing non-ground points (building and vegetation classes) and bare-ground elevation points. Non-ground points were removed from stereo pairs DEM using classified orthophoto polygons, and filled with contour DEM data. Also a 5th order trend surface over photo-based DEM was fitted and non-ground points were removed and filled using local interpolation. It was observed that automated photo-based extraction yields high precision terrain models in a short time, reducing manual editing; their accuracy is strictly related to image quality and terrain features. Results showed that such photogrammetric extracted DEM represents better accuracy along x and y directions than LiDAR does, while LiDAR has the best vertical accuracy, compared to other DEMs. The differences between horizontal errors are large since there were no significant differences between vertical errors of LiDAR and photo-based DEM. This indicates that there is a good correlation between elevation points of DEMs, and a stereo pair-based DEM can be a good substitute, whenever LiDAR is not affordable. This study provides several important insights into the magnitudes and spatial patterns of LiDAR and photo-based DEM errors, further studies need to verify the error extent in more diverse landscape. However, automated photo-based DEM extraction is currently an efficient method for collecting data useful for rural and small study area.

Dehvari, Abdolhamid; Heck, Richard John

2012-06-01

46

Landslide Volumetric Analysis Using Cartosat-1Derived DEMs  

Microsoft Academic Search

The monitoring of landscape changes can lead to the identification of environmental hot spots, improve process understanding, and provide means for law enforcement. Digital elevation models (DEMs) derived from stereoscopic satellite data provide a systematic synoptic framework that is potentially useful to support these issues. Along-track high-resolution stereoscopic data, provided with rational polynomial coefficients (RPCs), are ideal for the fast

Tapas R. Martha; Norman Kerle; Victor Jetten; Cees J. van Westen; K. Vinod Kumar

2010-01-01

47

In need of combined topography and bathymetry DEM  

Microsoft Academic Search

In many geoscience applications, digital elevation models (DEMs) are now more commonly used at different scales and greater resolution due to the great advancement in computer technology. Increasing the accuracy\\/resolution of the model and the coverage of the terrain (global model) has been the goal of users as mapping technology has improved and computers get faster and cheaper. The ETOPO5

K. Kisimoto; T. Hilde

2003-01-01

48

Evaluating error associated with lidar-derived DEM interpolation  

Microsoft Academic Search

Light detection and ranging (lidar) technology is capable of precisely measuring a variety of vegetation metrics, the estimates of which are usually based on relative heights above a digital elevation model (DEM). As a result, the development of these elevation models is a critical step when processing lidar observations. A number of different algorithms exist to interpolate lidar ground hits

Christopher W. Bater; Nicholas C. Coops

2009-01-01

49

Estimating impact force of granular avalanche on obstacles by DEM  

NASA Astrophysics Data System (ADS)

The paper presents a DEM model which allows the simulation of dry granular avalanche flow down incline. It allows the simulation of the flow pattern and computation of impact forces on rigid obstacles. The model is compared with experimental data in literature. The experiments include granular flow along an inclined channel and three-dimensional free surface flow along an inclined cute merging into a horizontal run-out region. The introduction of the constraint of particle rotation allows realistic description of the flow behavior. The influence of the model parameters on granular flow is studied, e.g. the run-out distance, deposition pattern, flow pattern and impact forces against obstacle. The three-dimensional DEM is an appropriate tool for modeling granular flows and their interactions with obstacles. Due to the fully three-dimensional approach it is possible to calculate the impact forces with these simulation techniques. It is shown that the model performance is strongly dependent on the rotation control. Without any rotation constraint the flow behavior of rough and angular granules cannot be described by DEM correctly. The comparison of impact forces and flow patterns with laboratory experiments shows the potential of DEM for a wide range of laboratory setups.

Teufelsbauer, Harald; Wang, Yongqi; Wawra, Markus; Wu, Wei

2010-05-01

50

DIGITAL ELEVATION MODEL (DEM) FILES (30 M) FOR NORTH CAROLINA  

EPA Science Inventory

Digital Elevation Model files, 30-m resolution, for North Carolina from US Geological Survey Web site: http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/7_min_dem/states/NC.html Files listed for NC but centered in TN, GA, and VA are not included. All file archives were downloaded an...

51

DEM integrity monitor experiment (DIME) flight test results  

NASA Astrophysics Data System (ADS)

This paper discusses flight test results of a Digital Elevation Model (DEM) integrity monitor. The DEM Integrity Monitor Experiment (DIME) was part of the NASA Synthetic Vision System (SVS) flight trials at Eagle-Vail, Colorado (EGE) in August/September, 2001. SVS provides pilots with either a Heads-down Display (HDD) or a Heads-up Display (HUD) containing aircraft state, guidance and navigation information, and a virtual depiction of the terrain as viewed 'from the cockpit'. SVS has the potential to improve flight safety by increasing the situational awareness (SA) in low to near zero-visibility conditions to a level of awareness similar to daytime clear-weather flying. This SA improvement not only enables low-visibility operations, but may also reduce the likelihood of Controlled Flight Into Terrain (CFIT). Because of the compelling nature of SVS displays high integrity requirements may be imposed on the various databases used to generate the imagery on the displays even when the target SVS application does not require an essential or flight-critical integrity level. DIME utilized external sensors (WAAS and radar altimeter) to independently generate a 'synthesized' terrain profile. A statistical assessment of the consistency between the synthesized profile and the profile as stored in the DEM provided a fault-detection capability. The paper will discuss the basic DIME principles and will show the DIME performance for a variety of approaches to Runways 7 and 25 at EGE. The monitored DEMs are DTED Level 0, USGS with a 3-arcsec spatial resolution, and a DEM provided by NASA Langley. The test aircraft was a Boeing 757-200.

Uijt de Haag, Maarten; Young, Steve D.; Sayre, Jonathon; Campbell, Jacob; Vadlamani, Ananth

2002-07-01

52

Precise integrated topography of Dokdo, East Sea, Korea, using LIDAR DEM and Multibeam echo sounding data  

Microsoft Academic Search

In this study, We created and analyzed Precise integrated topography of Dokdo, East Sea, Korea, using land data that were collected by airborne LIDAR(Light Detection and Ranging) DEM(Digital Elevation Model) and seafloor bathymetry data by Multi-beam echo sounder. Airborne LIDAR DEM represent more detailed topography of land than other DEM data. Composition of airborne LIDAR DEM and aerial photograph produced

C. Kim; H. Joo; E. Jeong; S. Lee; H. Kim

2009-01-01

53

Assessment of Digital Elevation Model (DEM) aggregation methods for hydrological modeling: Lake Chad basin, Africa  

Microsoft Academic Search

Digital Elevation Models (DEMs) are used to compute the hydro-geomorphological variables required by distributed hydrological models. However, the resolution of the most precise DEMs is too fine to run these models over regional watersheds. DEMs therefore need to be aggregated to coarser resolutions, affecting both the representation of the land surface and the hydrological simulations. In the present paper, six

Mathieu Le Coz; François Delclaux; Pierre Genthon; Guillaume Favreau

2009-01-01

54

Constructing DEM from characteristic terrain information using HASM method  

NASA Astrophysics Data System (ADS)

In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

Song, Dunjiang; Yue, Tianxiang; Du, Zhengping; Wang, Qingguo

2009-09-01

55

Poisson disk sampling in geodesic metric for DEM simplification  

NASA Astrophysics Data System (ADS)

To generate highly compressed digital elevation models (DEMs) with fine details, the method of Poisson disk sampling in geodesic metric is proposed. The main idea is to uniformly pick points from DEM nodes in geodesic metric, resulting in terrain-adaptive samples in Euclidean metric. This method randomly selects point from mesh nodes and then judges whether this point can be accepted in accordance with the related geodesic distances from the sampled points. The whole process is repeated until no more points can be selected. To further adjust the sampling ratios in different areas, weighted geodesic distance, which is in relation to terrain characteristics, are introduced. In addition to adaptability, sample distributions are well visualised. This method is simple and easy to implement. Cases are provided to illustrate the feasibility and superiority of the proposed method.

Hou, Wenguang; Zhang, Xuming; Li, Xin; Lai, Xudong; Ding, Mingyue

2013-08-01

56

DEM Mapping of Stream Power for Southern Ontario Streams  

NASA Astrophysics Data System (ADS)

Mapping of stream power along a stream system, a known determinant of channel form and dynamics, is a valuable component of geomorphic stream assessment procedures that, unlike current methods, is physically-based, time- and cost-effective, objective and repeatable. Continuous maps of tream power can be obtained by extracting channel slope from DEMs and combining them with a discharge-drainage area function. Using the case of Highland Creek, a highly urbanized basin in Scarborough Ontario for which extensive data and background information is available, it is shown that reliable and precise stream power maps can be obtained from the Ontario provincial DEM. Local stream power variation can be seen to match known features of the channel and both reach-scale and overall trends in stream power match those from a 1D computational model (HEC-RAS). Stream power maxima and minima also coincide with known areas of channel instability and deposition.

Ferencevic, M.; Ashmore, P.

2009-05-01

57

Mapping debris-flow hazard in Honolulu using a DEM  

USGS Publications Warehouse

A method for mapping hazard posed by debris flows has been developed and applied to an area near Honolulu, Hawaii. The method uses studies of past debris flows to characterize sites of initiation, volume at initiation, and volume-change behavior during flow. Digital simulations of debris flows based on these characteristics are then routed through a digital elevation model (DEM) to estimate degree of hazard over the area.

Ellen, Stephen, D.; Mark, Robert, K.; Mark, Robert, K.

1993-01-01

58

Krankheiten auf dem Gebiet der Mund-, Kiefer- und Gesichtschirurgie  

Microsoft Academic Search

Das Gesicht des Menschen vereinigt wichtige Funktionen wie Sprache, Kaufunktion und Schlucken und erfüllt zugleich auch mit\\u000a seiner Form eine sehr wichtige Funktion für die Persönlichkeit. Störungen in diesen Bereichen haben oft komplexe Ursachen\\u000a und beeinflusssen sich gegenseitig, weswegen eine Begutachtung den beiden Aspekten Form und Funktion des Gesichtes gerecht\\u000a werden muss. Dies kann vom Gutachten auf dem Gebiet der

S. Reinert

59

A new morphology algorithm for shoreline extraction from DEM data  

NASA Astrophysics Data System (ADS)

Digital elevation models (DEMs) are a digital representation of elevations at regularly spaced points. They provide an accurate tool to extract the shoreline profiles. One of the emerging sources of creating them is light detection and ranging (LiDAR) that can capture a highly dense cloud points with high resolution that can reach 15 cm and 100 cm in the vertical and horizontal directions respectively in short periods of time. In this paper we present a multi-step morphological algorithm to extract shorelines locations from the DEM data and a predefined tidal datum. Unlike similar approaches, it utilizes Lowess nonparametric regression to estimate the missing values within the DEM file. Also, it will detect and eliminate the outliers and errors that result from waves, ships, etc by means of anomality test with neighborhood constrains. Because, there might be some significant broken regions such as branches and islands, it utilizes a constrained morphological open and close to reduce these artifacts that can affect the extracted shorelines. In addition, it eliminates docks, bridges and fishing piers along the extracted shorelines by means of Hough transform. Based on a specific tidal datum, the algorithm will segment the DEM data into water and land objects. Without sacrificing the accuracy and the spatial details of the extracted boundaries, the algorithm should smooth and extract the shoreline profiles by tracing the boundary pixels between the land and the water segments. For given tidal values, we qualitatively assess the visual quality of the extracted shorelines by superimposing them on the available aerial photographs.

Yousef, Amr H.; Iftekharuddin, Khan; Karim, Mohammad

2013-03-01

60

Satellitengeodäsie. Ergebnisse aus dem gleichnamigen Sonderforschungsbereich der Technischen Universität München.  

NASA Astrophysics Data System (ADS)

Contents: Teil I. Bedeutung künstlicher Erdsatelliten für die Geodäsie. Stand der geodätischen Arbeiten zur Zeit der Gründung des Sonderforschungsbereichs 78 "Satellitengeodäsie" (R. Sigl). Teil II. 1. Fundamentalstation Wettzell: Konzept und Rolle von Fundamentalstationen (M. Schneider). Das 20-m-Radioteleskop (R. Kilger). Stationäre Laserentfernungsmeßsysteme (R. Dassing, R. Höpfl, W. Schlüter). Das mobile Laserentfernungsmeßsystem MTLRS-1 (H. Junginger, P. Wilson). Zeit und Frequenz (W. Schlüter). Terrestrische Messungen (W. Schlüter, B. Richter, G. Reichert). 2. Orientierung der Erde: Astronomische Fragen und Antworten (P. Brosche). Definition und Realisierung von Referenzsystemen im Zusammenhang mit Laserentfernungsmessungen zum Satelliten LAGEOS (C. Reigber, P. Schwintzer). Erdrotationsparameter - abgeleitet aus Laserentfernungsmessungen zum Satelliten LAGEOS (P. Schwintzer, W. Barth, C. Reigber). Bestimmung der Erdrotationsparameter durch VLBI (H. Schuh). 3. Schwerefeld der Erde: Überblick über Stand und Entwicklung von Erdschweremodellen zur präzisen Bahnbestimmung bei geodynamischen Anwendungen (C. Reigber). Zukünftige Möglichkeiten der globalen hochauflösenden Schwerefeldbestimmung (K. H. Ilk). 4. Geodynamische Anwendungen: Die Nutzung geodätischer Raummethoden in der Geodynamik-Forschung (H. Drewes, E. Reinhart, P. Wilson). Basislängenänderungen - abgeleitet aus VLBI-Beobachtungen im Projekt IRIS (J. Campbell). Globale relative Stationsbewegungen - abgeleitet aus Laserentfernungsmessungen zum Satelliten LAGEOS (C. Reigber, P. Schwintzer, H. Müller, F.-H. Massmann). Stand und Entwicklung des WEGENER-MEDLAS-Projekts (P. Wilson, E. Reinhart). MEDLAS-Stationskoordinaten und Basislinien 1986 (H. Hauck, C. Reigber, P. Wilson). Modellierung geodynamischer Deformationen im Mittelmeerraum (H. Drewes, E. Geiß). Interpretation des globalen Erdschwerefeldes im Hinblick auf die Geodynamik (H. Drewes). 5. Satellitengeodäsie - nach-Newtonsch (M. Soffel, H. Ruder, M. Schneider). Teil III. Schlußbetrachtung (M. Schneider). Teil IV. Dokumentarischer Anhang.

Schneider, M.; Deutsche Forschungsgemeinschaft, Dfg

61

DEM simulation of heat transfer in granular materials  

NASA Astrophysics Data System (ADS)

This study investigates the heat conduction of low conductivity granular particles in a two-dimensional modeling of a rotary drum using discrete element method (DEM) method. The Shannon entropy and Lagrangian mean temperature difference are used for comparative study. The results obtained by these two methods are in accordance with each other. It shows the evolution of heat conduction in rotary drums can be divided into a dynamically dominated stage and a thermodynamically dominated stage. The former is determined mainly by particle mixing and the latter is by particle-particle contact duration. The mechanisms for these two stages are explained and the heat transfer characteristics in these two stages are explored.

Gui, Nan; Xu, Wenkai; Ge, Liang

2013-07-01

62

EXTRACTING INLAND FLOODING HAZARDOUS AREA BY USING DEM  

NASA Astrophysics Data System (ADS)

In this study, a simple method is proposed to extract inland flooding hazardous area by using 5m resolution DEM, which is freely offered by GSI (Geospational Information Authority of Japan). Catchment area is estimated in two ways; flow accumulation analysis in a plain. Potential inflow amount is estimated by counting the number of pixels located along a upper flow of the target pixels. The number of higher elevation pixles is also counted in the surrounding of the target pixels as a flooding hazardous areas.

Nonomura, Atsuko; Kamada, Shougo; Hasegswa, Shuichi; Hayashi, Hirotoshi

63

Gesellschaften aus dem Verband Stipion calamagrostis in der Südwestslowakei  

Microsoft Academic Search

In den Gebirgen Považský Inovec und Malé Karpaty konnten wir das Vorkommen von Artenkombinationen und charakteristischen Standorten\\u000a der Pionierschuttgesellschaften aus der KlasseThlaspietea rotundifolii\\u000a Br.-Bl. et al. 1948 feststellen Zu ihnen gehört dasGaleopsietum angustifoliae (Libbert 1938)Bükker 1942 und dieEpilobium dodonaei-Seseli osseum-Gesellschaft aus dem VerbandStipion calamagrostis. In der Arbeit wurde erhöhte Aufmerksamkeit der synmorphologischen und synökologischen Charakteristik und syntaxonomischen\\u000a Einordnung gewidment.

Štefan Maglocký; Ladislav Mucina

1980-01-01

64

Intraoperative Radiotherapie (IORT) beim Mammakarzinom mit dem INTRABEAM-System  

Microsoft Academic Search

Zusammenfassung  Die intraoperative Radiotherapie (IORT) des Tumorbettes mit dem INTRABEAM-System (Carl Zeiss, Oberkochen) während der brusterhaltenden\\u000a Operation wird derzeit in einer randomisierten klinischen Studie (TARGIT) an einem hochselektionierten Patientinnenkollektiv\\u000a untersucht. Patientinnen >50 Jahre mit einem unifokalen, duktal-invasiven Karzinom <2 cm können eingeschlossen werden. Die\\u000a Mammahomogenbestrahlung wird mit einer alleinigen einmaligen IORT kombiniert mit einer perkutanen Bestrahlung nur bei Risikofaktoren\\u000a [extensive intraduktale Komponente (EIC),

F. Wenz; V. Steil; C. Herskind; H. Sommer; K. Friese; M. Sütterlin; U. Kraus-Tiefenbacher

2007-01-01

65

Determination of fibrillatory frequency for assessment of the atrial electrophysiologic state in human atrial fibrillation –  

Microsoft Academic Search

\\u000a Zusammenfassung   Vorhofflimmern (VHF) ist das elektrographische Bild mehrerer simultaner Kreiserregungen in den Vorhöfen. Weder der natürliche\\u000a Verlauf von VHF noch die Effektivität therapeutischer Maßnahmen sind mit klinischen oder echokardiographischen Variablen vorhersagbar.¶???Im\\u000a Gegensatz dazu konnten verschiedene Untersuchungen einen Zusammenhang zwischen invasiv ermittelter atrialer Flimmerfrequenz\\u000a (atriale Zykluslänge) und VHF-Komplexität, klinischem Verhalten sowie Kardioversionserfolg feststellen. Die atriale Flimmerfrequenz\\u000a kann ebenfalls aus dem Oberflächen-EKG

A. Bollmann; H. U. Klein; H.-D. Esperer

2000-01-01

66

Monte Carlo Markov chain DEM reconstruction of isothermal plasmas  

NASA Astrophysics Data System (ADS)

Context. Recent studies carried out with SOHO and Hinode high-resolution spectrometers have shown that the plasma in the off-disk solar corona is close to isothermal. If confirmed, these findings may have significant consequences for theoretical models of coronal heating. However, these studies have been carried out with diagnostic techniques whose ability to reconstruct the plasma distribution with temperature has not been thoroughly tested. Aims: In this paper, we carry out tests on the Monte Carlo Markov chain (MCMC) technique with the aim of determining: 1) its ability to retrieve isothermal plasmas from a set of spectral line intensities, with and without random noise; 2) to what extent can it discriminate between an isothermal solution and a narrow multithermal distribution; and 3) how well it can detect multiple isothermal components along the line of sight. We also test the effects of 4) atomic data uncertainties on the results, and 5) the number of ions whose lines are available for the DEM reconstruction. Methods: We first use the CHIANTI database to calculate synthetic spectra from different thermal distributions: single isothermal plasmas, multithermal plasmas made of multiple isothermal components, and multithermal plasmas with a Gaussian DEM distribution with variable width. We then apply the MCMC technique on each of these synthetic spectra, so that the ability of the MCMC technique at reconstructing the original thermal distribution can be evaluated. Next, we add a random noise to the synthetic spectra, and repeat the exercise, in order to determine the effects of random errors on the results. We also we repeat the exercise using a different set of atomic data from those used to calculate synthetic line intensities, to understand the robustness of the results against atomic physics uncertainties. The size of the temperature bin of the MCMC reconstruction is varied in all cases, in order to determine the optimal width. Results: We find that the MCMC technique is unable to retrieve isothermal plasmas to better than ?log T ? 0.05. Also, the DEM curves obtained using lines calculated with an isothermal plasma and with a Gaussian distribution with FWHM of log T ? 0.05 are very similar. Two near-isothermal components can be resolved if their temperature separation is ?log T = 0.2 or larger. Thus, DEM diagnostics has an intrinsic resolving power of log T = 0.05. Atomic data uncertainties may significantly affect both temperature and peak DEM values, but do not alter our conclusions. The availability of small sets of lines also does not worsen the performance of the MCMC technique, provided these lines are formed in a wide temperature range. Conclusions: Our analysis shows the present limitations in our ability to identify the presence of strictly isothermal plasmas in stellar and solar coronal spectra.

Landi, E.; Reale, F.; Testa, P.

2012-02-01

67

Generating, Comparing and Exploiting DEMs for Hydrological Applications over the Galapagos Islands  

NASA Astrophysics Data System (ADS)

Understanding the hydrological cycle of the Galapagos Islands will contribute to more efficient water management in insular basaltic environments with growing anthropogenic pressure and ecosystems to preserve. Lack of essential existing in-situ data such as topography led to retrieving this information from other sources. We present the generation from satellite data of digital elevation model (DEM) and its exploitation for the Santa Cruz island. An interferometric DEM was generated from ASAR (ENVISAT) data with Atlantis EarthView and a radargrammetric DEM using multiple incidence angle capacity of ASAR was generated by Gamma Remote Sensing. SRTM 90 m resolution data (NASA) and a digitalised topographic contour DEM (M. Souris, IRD) were used to aid the phase unwrapping and for comparison and validation. Combining the radargrammetric DEM (overall accurate, few detail) and the interferometric DEM (unresolved in uncoherent areas but high definition in coherent areas), it is hoped to achieve a resolution better than the 90 m SRTM data and which can be compared to the 30 m resolution SRTM data which has been requested from NASA. Drainage networks were extracted and identified on Santa Cruz and zones of interest for the setting up of hydrological instruments are defined. Radargrammetric versus interferometric method of DEM generation in volcanic insular environment is reviewed in this work. Resolution of the DEM will be a limiting factor to the accuracy of transposition from image to fieldwork. Background hydrological information from the DEM can be used in the hydrological modelling.

D'Ozouville, N.; Benveniste, J.; Deffontaines, B.; Violette, S.; de Marsily, G.; Wegmuller, U.

68

Comparative Influence of Terrain Slope and Canopy Closure on Lidar DEM Accuracy  

NASA Astrophysics Data System (ADS)

The use of Lidar (Light Detection and Ranging) technology is becoming one of the most effective and reliable means of collecting a variety of terrain and vegetation data. Most Lidar based estimates come from the creation of digital elevation models (DEM). As a result of the DEM’s importance in using Lidar data as a management tool, it is necessary to understand the variables that influence the DEM accuracy. Two of these variables, terrain slope and percent canopy closure, were investigated in a mixed conifer forest and woodland area in central Idaho. Following the creation of a DEM from the last return Lidar points, a series of 54 fixed radius plots were stratified by 3 slope classes from 0% to 45% and 3 canopy closures classes from 0% to 95% and surveyed using a laser total station and differential GPS for DEM accuracy analysis. Within each tenth acre plot a grid consisting of 80 ground points was collected along with a point for each tree and each 1,000 hour fuel, further data was collected to classify the canopy and the fuel loading. Each plot was processed to create a DEM for comparison to the Lidar derived DEM. These results will have implications in the development and use of high-resolution DEM models derived from Lidar data for natural resource managers.

Tinkham, W.; Smith, A. M.; Hudak, A. T.; Gessler, P.; Swanson, M.

2009-12-01

69

Improving Cartosat-1 DEM accuracy using synthetic stereo pair and triplet  

NASA Astrophysics Data System (ADS)

Cartosat-1 is the first Indian Remote Sensing Satellite capable of providing along-track stereo images. Cartosat-1 provides forward stereo images with look angles +26° and -5° with respect to nadir for generating Digital Elevation Models (DEMs), Orthoimages and value added products for various applications. A pitch bias of -21° to the satellite resulted in giving reverse tilt mode stereo pair with look angles of +5° and -26° with respect to nadir. This paper compares DEMs generated using forward, reverse and other possible synthetic stereo pairs for two different types of topographies. Stereo triplet was used to generate DEM for Himalayan mountain topography to overcome the problem of occlusions.For flat to undulating topography it was shown that using Cartosat-1 synthetic stereo pair with look angles of -26° and +26° will produce improved version of DEM. Planimetric and height accuracy (Root Mean Square Error (RMSE)) of less than 2.5 m and 2.95 m respectively were obtained and qualitative analysis shows finer details in comparison with other DEMs. For rugged terrain and steep slopes of Himalayan mountain topography simple stereo pairs may not provide reliable accuracies in DEMs due to occlusions and shadows. Stereo triplet from Cartosat-1 was used to generate DEM for mountainous topography. This DEM shows better reconstruction of elevation model even at occluded region when compared with simple stereo pair based DEM. Planimetric and height accuracy (RMSE) of nearly 3 m were obtained and qualitative analysis shows reduction of outliers at occluded region.

Giribabu, D.; Srinivasa Rao, S.; Krishna Murthy, Y. V. N.

2013-03-01

70

Bistatic system and baseline calibration in TanDEM-X to ensure the global digital elevation model quality  

NASA Astrophysics Data System (ADS)

TanDEM-X is an operational satellite mission with the goal of generating a high quality global digital elevation model (DEM) based on synthetic aperture radar (SAR) interferometry in X-band. In order to ensure the quality of the DEM, the differential range measurements and knowledge of the interferometric baseline have to be extremely accurate. In this paper, the bistatic system calibration strategy implemented in TanDEM-X to achieve the desired DEM quality will be described, focusing on the baseline calibration procedure. The results of the tests, which were performed in parallel to the operational DEM acquisition, verify the suitability of this approach.

Hueso González, Jaime; Walter Antony, John Mohan; Bachmann, Markus; Krieger, Gerhard; Zink, Manfred; Schrank, Dirk; Schwerdt, Marco

2012-09-01

71

Dense, Fe-rich Ejecta in Supernova Remnants DEM L238 and DEM L249: A New Class of Type Ia Supernova?  

Microsoft Academic Search

We present observations of two LMC supernova remnants (SNRs), DEM L238 and\\u000aDEM L249, with the Chandra and XMM-Newton X-ray satellites. Bright central\\u000aemission, surrounded by a faint shell, is present in both remnants. The central\\u000aemission has an entirely thermal spectrum dominated by strong Fe L-shell lines,\\u000awith the deduced Fe abundance in excess of solar and not consistent

Kazimierz J. Borkowski; Sean P. Hendrick; Stephen P. Reynolds

2006-01-01

72

Clustering of Zagros Ranges from the Globe DEM representation  

NASA Astrophysics Data System (ADS)

The DEM to mountain transformation was implemented in the Globe DEM representation of Zagros Ranges in south Iran, where collision of the Arabian shield with Iran has produced a spectacular mountainous physiography. An object partitioning framework of the landscape was defined on the basis of the mount and the non-mount terrain classes as well as the isolated mountain features. A parametric representation was achieved on the basis of geomorphometric parameters related to elevation and gradient. Descriptive statistics, frequency distributions and the linear regression between attributes were used in an attempt to characterise landscape. Finally, a terrain classification scheme based on cluster analysis was implemented and the landscape of the study area was mapped on the basis of mountain geomorphometry. From the geomorphometric point of view, Zagros Ranges was proved to be an uplifted landscape, equally developed in the whole elevation range with only one major peneplain at the sea level. The terrain was sloping vertically to the main axis of the mountain ranges while the asymmetry observed towards SW was interpreted as the result of the collision of Arabian shield to Iran. The linear regression between local relief, gradient and size of the mountains captured the geometric signature of the study area. The centroid clustering method revealed clearly the SE-NW stair-step topography observed in Zagros Ranges while the steepest and more massive mountains were also observed along this direction. The zones derived by the mapping of clusters were associated to the existing morphotectonic zones of the study area while geomorphometric processing proved capable of segmenting morphotectonic zones to sub-regions with different geomorphometry.

Miliaresis, George; Iliopoulou, Polixeni

2004-02-01

73

CFD–DEM simulation of the gas–solid flow in a cyclone separator  

Microsoft Academic Search

In this work, a numerical study of the gas–solid flow in a gas cyclone is carried out by use of the combined discrete element method (DEM) and computational fluid dynamics (CFD) model where the motion of discrete particles phase is obtained by DEM which applies Newton’s equations of motion to every individual particle and the flow of continuum fluid by

K. W. Chu; B. Wang; D. L. Xu; Y. X. Chen; A. B. Yu

2011-01-01

74

The effects of DEM resolution and neighborhood size on digital soil survey  

Microsoft Academic Search

Terrain characteristics, such as slope gradient, slope aspect, profile curvature, contour curvature computed from digital elevation model (DEM), are among the key inputs to digital soil surveys based on geographic information systems (GIS). These terrain attributes are computed over a neighborhood (spatial extent). The objective of this research was to investigate the combined effect of DEM resolution and neighborhood size

Michael P. Smith; A-Xing Zhu; James E. Burt; Cynthia Stiles

2006-01-01

75

Establishing predictive capabilities of DEM - Verification and validation for complex granular processes  

NASA Astrophysics Data System (ADS)

The discrete element method has been increasingly used to model granular processes of increasing complexity, from dry to wet to multiphase systems. Whilst DEM has been shown to produce qualitatively many of the complex phenomena observed in these complex granular systems, establishing the extent of the predictive capability of DEM model is still in its infancy. This summary paper discusses the need to develop verification and validation methodologies with regard to DEM computations. It proposes the need to first verify that a DEM code with its implemented mathematical model and computation algorithm is accurately reproducing the conceptual model and its solution, before validating to determine the degree to which the computational model accurately represent the physics being modelled. It also discusses the associated issue of data analysis to extract the parameters of interest from DEM particle scale data.

Ooi, Jin Y.

2013-06-01

76

Performance of ASTER and SRTM DEMs, and their potential for assessing glacial lakes in the Lunana region, Bhutan Himalaya  

Microsoft Academic Search

To assess the potential volume of a glacial lake outburst flood (GLOF) more precisely than in previous studies, we analyze ground survey data and remote-sensing digital elevation models (DEMs) around glacial lakes in the Lunana region, Bhutan. Based on a DEM generated from differential GPS ground surveys, we first evaluate the relative accuracies of DEMs produced by the Advanced Spaceborne

Koji Fujita; Ryohei Suzuki; Takayuki Nuimura; Akiko Sakai

2008-01-01

77

Evaluation of topographic index in relation to terrain roughness and DEM grid spacing  

NASA Astrophysics Data System (ADS)

Topographic index is an important attribute of digital elevation model (DEM) which indicates soil saturation. It is used for estimation of run-off, soil moisture, depth of ground water and hydrological simulation. Topographic index is derived from DEMs; hence the accuracy of DEM influences its computation. Commonly the raster based grid DEM is widely used to simulate hydrological model parameter, and accuracy varies with respect to DEM grid size and morphological characteristics of terrain. In this study topographic index is evaluated in terms of DEM grid size and terrain roughness. The study was carried out on four small watersheds, having different roughness characteristics, located over the Himalayan terrain. Topographic index surface is derived for each watershed from different grid spacing DEM (10-150 m), analysed and validated. It is found that DEM grid spacing affects the topographic index. The surface representation is smooth in the coarse grid spacing and the pattern of topographic index changes with grid spacing. The spatial autocorrelation of topographic index surface reduces when calculated from larger spacing DEM. The mean of the topographic index surface increases and standard deviation decreases with the increase of grid spacing and the effect is more pronounced in the rough terrain. Accuracy of the topographic index is also evaluated with respect to grid spacing and terrain roughness by comparing the topographic index surface with respect to reference data (10 m grid spacing topographic index surface). The RMSE and mean error of topographic index surface increases in larger grid spacing and the effect is more in rugged terrain.

Mukherjee, Samadrita; Mukherjee, Sandip; Garg, R. D.; Bhardwaj, A.; Raju, P. L. N.

2013-06-01

78

How does modifying a DEM to reflect known hydrology affect subsequent terrain analysis?  

NASA Astrophysics Data System (ADS)

Many digital elevation models (DEMs) have difficulty replicating hydrological patterns in flat landscapes. Efforts to improve DEM performance in replicating known hydrology have included a variety of soft (i.e. algorithm-based approaches) and hard techniques, such as “Stream burning” or “surface reconditioning” (e.g. Agree or ANUDEM). Using a representation of the known stream network, these methods trench or mathematically warp the original DEM to improve how accurately stream position, stream length and catchment boundaries replicate known hydrological conditions. However, these techniques permanently alter the DEM and may affect further analyses (e.g. slope). This paper explores the impact that commonly used hydrological correction methods (Stream burning, Agree.aml and ANUDEM v4.6.3 and ANUDEM v5.1) have on the overall nature of a DEM, finding that different methods produce non-convergent outcomes for catchment parameters (such as catchment boundaries, stream position and length), and differentially compromise secondary terrain analysis. All hydrological correction methods successfully improved calculation of catchment area, stream position and length as compared to using the DEM without any modification, but they all increased catchment slope. No single method performing best across all categories. Different hydrological correction methods changed elevation and slope in different spatial patterns and magnitudes, compromising the ability to derive catchment parameters and conduct secondary terrain analysis from a single DEM. Modification of a DEM to better reflect known hydrology can be useful, however knowledge of the magnitude and spatial pattern of the changes are required before using a DEM for subsequent analyses.

Callow, John Nikolaus; van Niel, Kimberly P.; Boggs, Guy S.

2007-01-01

79

Investigation of the Critical State in Soil Mechanics Using DEM  

SciTech Connect

The existence and uniqueness of the so-called critical state in soil mechanics is validated in our DEM simulations of irregular polygonal particles. For different particle shape characteristics, the critical state is independent of the initial stress and density conditions. We retain low stress levels, since we do not take into account the crushing of particles. In biaxial test simulations isotropic particles evolve toward a limiting state in which the system reaches a critical void ratio and deforms with constant volume, deviatoric stress, fabric anisotropy, and mechanical coordination number. The last one has been found to be the first variable to attain a critical value making possible for the rest of micro-and-macro-mechanical variables the convergence to the critical state. In periodic shear cell tests, for large shear deformations samples with anisotropic particles reach at the macro-mechanical level the same critical value for both shear force and void ratio. At the micro-mechanical level the components of the stress tensor, the fabric tensor and the inertia tensor of the particles also reach the same stationary state. By varying the aspect ratio of the particles we stated the strong influence of particle shape anisotropy on the parameters that the granular packing attained at the critical state.

Pena, Andres A. [Bilfinger Berger GmbH, Gustav-Nachtigal 3, 65915 Wiesbaden (Germany); ICP, University of Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart (Germany); Garcia-Rojo, Ramon [EPCOS, Avda. Jose Ortega y Gasset 173, 29006 Malaga (Spain); Alonso-Marroquin, Fernando [MoSCoS, School of Mathematics and Physics, University of Queensland, St. Lucia, Qld. 4067 (Australia); Herrmann, Hans J. [Departamento de Fisica, Universidade Federal do Ceara, 60451-970 Fortaleza, Ceara (Brazil); Computational Physics, IfB, HIF E12, ETH Hoenggerberg, CH-8093 Zuerich (Switzerland)

2009-06-18

80

SRTM DEM levels over papyrus swamp vegetation - a correction approach  

NASA Astrophysics Data System (ADS)

The SRTM DEM, a digital elevation model based on the Shuttle Radar Topography Mission of February 2000 is a source of elevation data with nearly worldwide coverage. It has proven its usefulness in various regions but problems persist for densely vegetated areas where, caused by the organic matter and water content of the vegetation, the radar signal is reflected at some level between the vegetation canopy and the ground level. This level varies with different types and densities of vegetation cover and has so far not been assessed for papyrus areas. The paper describes the approach and establishment of a correction factor for a pilot area in the Sudd swamps of southern Sudan based on comparison of SRTM reference levels and ground control points collected during field surveys between 2004 and 2006. Results show a correction factor between the sensed and the real surface of 4.66 m and a average penetration depth of the radar signal into the dense papyrus vegetation of 0.34 m.

Petersen, G.; Lebed, I.; Fohrer, N.

2009-08-01

81

Penetration strength of coarse granular materials from DEM simulations  

NASA Astrophysics Data System (ADS)

Field tests are widely used for soil characterization in geotechnical applications in spite of implementation difficulties. The light penetrometer test is a well-known testing tool for fine soils, but the physical interpretation of the output data in the case of coarse granular materials is far less evident. In fact, the data are considerably more sensitive to various parameters such as fabric structure, particles shape or the applied impact energy. In order to achieve a better understanding of the underlying phenomena, we performed a numerical study by means contact dynamics DEM simulations. We consider the penetration of a moving tip into a sample composed of irregular grain shapes and we analyze the influence of the driving velocity and applied energy on the penetration strength. We find that the latter grows with both the penetration rate and energy. Force fluctuations on the tip involve a jamming-unjamming process. The typology of contact network and inter-granular friction play a major role in the fluctuations and measured values of the cone penetration strength.

Quezada, Juan Carlos; Saussine, Gilles; Breul, Pierre; Radjai, Farhang

2013-06-01

82

Grain sedimentation with SPH-DEM and its validation  

NASA Astrophysics Data System (ADS)

Our mesoscale simulation method [M. Robinson, S. Luding, and M. Ramaioli, submitted (2013)] for multiphase fluid-particle flows couples Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM) and enjoys the flexibility of meshless methods, such as being capable to handling free surface flows or flow around complex and/or moving geometries. We use this method to simulate three different sedimentation test cases and compare the results to existing analytical solutions. The grain velocity in Single Particle Sedimentation compares well (< 2% error) with the analytical solution as long as the fluid resolution is coarser than two times the particle diameter. The multiple particle sedimentation problem and Rayleigh Taylor Instability (RTI) also perform well against the theory, but it was found that the method is susceptible to fluid velocity fluctuations in the presence of high porosity gradients. These fluctuations can be damped by the addition of a dissipation term, which has no effect on the terminal velocity but can lead to slower growth rates for the RTI.

Robinson, Martin; Luding, Stefan; Marco Ramaioli, Marco

2013-06-01

83

DEM application and qualification with regard to terrain analysis, land use classification and watershed modeling  

NASA Astrophysics Data System (ADS)

This thesis addresses removing the errant elevation values from computer-extracted Digital Elevation Model (DEM) and their application as an alternative to Light Detection And Ranging (LiDAR) on slightly undulated landscape near the eastern shore of Lake Huron, Ontario, Canada. The effect of DEM resolution on the computation of terrain attributes, the role of DEM in land cover mapping and estimating of runoff, and sediment yield using different DEM resolutions are also studied. Large differences were observed between 1 and 10 m resolutions on all topographical and hydrological attributes, showing that 10 m DEM is too coarse for this landscape, as the trend of plan curvature indicated that at least a 4 m DEM can capture the grain (longest significant relief wavelength) in this landscape. Removing non-ground points using an orthophoto does not require predefined thresholds values, compared to complex filtering algorithms. Photo-based DEM represented better horizontal accuracy while LiDAR showed best vertical accuracy, when compared together. There was not significant differences between vertical residual of DEM, showing that the photo-based DEM can be a good substitute, for computing terrain attributes whenever LiDAR are not affordable in this landscape. Classification accuracy was 60% in pixel-based classification, less than the object-oriented approach (80%), due to using only spectral information of image. The object-oriented approach showed that overall accuracy will increase to 94% by using LiDAR thematic layers and have positive effects on the segmentation process and applying membership functions. Furthermore, statistical analysis did not show significant differences between reference and classified data and the Kappa indicated that the best land cover map is produced by object-oriented approach using DEM thematic layer. Normalized runoff and sediment yield at Lucknow hydrometric station was significantly different compared to Water Erosion Prediction Project (WEPP) predicted values. The WEPP model with 1 m DEM resolution did not predict runoff or sediment yield significantly better than simulations using 5 and 10 m resolutions in this particular landscape. This conclusion is important and shows that it is not quite necessary to extract 1 m DEM resolution for watershed modeling using WEPP in this landscape, in future studies.

Dehvari, Abdolhamid

84

IPY: An excellent opportunity to improve Arctic DEMs and document today's Arctic for future generations  

NASA Astrophysics Data System (ADS)

Digital Elevation Models (DEMs) are an essential resource for any field or modeling study in the terrestrial Arctic, yet the DEMs available there are currently the worst on the planet. Efforts in the past decade have led to the acquisition of new DEMs for the entire Antarctic continent (Radarsat Antarctic Mapping Project, RAMP) and for nearly all of the planet within +/- 60 degrees latitude (Space Shuttle Radar Topography Mission, SRTM). Thus, the U.S. Arctic is left with 1:63,360 maps made during the IGY times, which does not meet the USGS' own standards for accuracy. Other countries are left in similar circumstances, with DEMs created from paper maps with usually no better than 1:50,000 scale, and there is as yet no central circum-polar clearinghouse for such DEMs. And because nearly all of these DEMs were created by digitizing paper base maps, most contain artifacts of the digitizing process that further reduce their quality. It could be argued that DEMs of the polar regions of the planet Mars are more accurate, consistent, and easily available than those from the Earth's Arctic. Only an organized international effort could possibly manage such a data collection task, and the project seems well suited to the goals of the International Polar Year. Perhaps being last in line for new DEMs is actually beneficial in this case, as technological improvements have led to new acquisition systems that are more accurate than those used in SRTM and RAMP. For example, airborne synthetic aperture radar (SAR) interferometry has demonstrated the capability to acquire DEMs with 5 meter postings, 1 cm vertical resolution, and 2 m vertical accuracies, in addition to an orthorectified radar backscatter image at 2.5 meter postings; compare this with the 60m x 90m posting available currently and no associated orthoimagery. That is, for the price of an Arctic DEM, we would also get a picture of the Arctic at 2.5 meter resolution, and this picture can be merged with color Landsat to create stunning orthorectified images. These SAR systems, flying on a LearJet, can rapidly acquire day or night in a wide range of weather, eliminating most of the logistical delays common to other systems. Airborne Lidar, a laser based system, is also advanced to the stage where near-shore coastal bathymetry can be measured, such that we could seamlessly integrate DEMs and bathymetry. While the price of such acquisitions is high, it is comparable to DEM acquisitions on the rest of the planet and Mars, and the benefits would be enormous to a wide variety of polar researchers - perfect for the IPY. Presented in this poster will be several examples of how new DEMs have improved our Arctic research at UAF. McCall Glacier was originally an IGY field site and now has the longest record of mass balance observations of any glacier in the US Arctic, but our measurement program is hampered by the lack of decent topographic maps there. Our research using a new DEM in the Kuparuk River watershed in Alaska has shown that these DEMs substantially improve our hydrological modeling in such low gradient watersheds. With DEMs of such high accuracy and resolution, we can also begin a program of repeat-topographic mapping, to document changes not only to glaciers, but subtler permafrost phenomena with decimeter-scale changes such as pingos, thermokarsts, polygons, and oriented lakes. The time to acquire such data is now, however, before widespread changes occur. Thus the upcoming IPY can perhaps leave no better legacy than to replace the IGY-era, mediocre topographic maps with an accurate, high-resolution digital elevation model representing today's Arctic, which will remain valuable to generations of polar scientists.

Nolan, M.

2003-12-01

85

Wissenschaftliche Abhandlungen  

NASA Astrophysics Data System (ADS)

Vorwort; 1. Über die Bewegung der Elektrzität in krummen Flächen; 2. Über die mechanische Bedeutung des zweiten Hauptsatzes der Wärmetheorie; 3. Über die Anzahl der Atome; 4. Über die Integrale linearer Differentialgleighungen; 5. Studien über das Gleichgewicht der lebendingen Kraft; 6. Lösung eines mechanischen Problems; 7. Über die Festigkeit zweier mit Druck übereinander gesteckter zylindrischer Röhren; 8. Über die elektrodynamische Wechselwirkung der Reile eines elektrishen Stromes von veränderlicher Gestalt; 9. Bemerkung zur Abhandlung des Herrn R. Most; 10. Erwiderung an Herrn Most; 11. Über die von bewegten Gasmassen geleistete Arbeit; 12. Noch einiges über Kohlrauschs Versuch; 13. Über die Ableitung der Grundgleichungen der Kapillarität; 14. Über eine neue optische Methode; 15. Boiling points of organic bodies; 16. Über die Druckkräfte, welche auf Ringe wriksam sind; 17. Zur Priorität der Auffindung der Beziehung zwischen dem zweiten Hauptsatze der mechanischen Wärmetheorie; 18. Über das Wärmegleichgewicht zwischen mehratomigen Gasmolekülen; 19. Einige allgemeine Sätze über Wärmegleichgewicht; 20. Analytischer Beweis des zweiten Hauptsatzen der mechanischen Wärmetheorie; 21. Über das Wirkungsgesetz der Molekülarkräfte; 22. Weiteren Studien über das Wärmegleichgewicht unter Gasmolekülen; 23. Resultate einer Experimentaluntersuchung; 24. Experimentelle Bestimmung der Dielektrizitätskonstante von Isolatoren; 25. Experimentaluntersuchung über die elektrostatische Fernwirkung dielektrischer Körper; 26. Experimentelle Bestimmung der Dielektrizitätskonstante einiger Gase; 27. Über einige an meinen Versuchen; 28. Über die Verschiedenheit der Dielektrizitätskonstante des Körper unter dem Einflusse elektrische Kräfte; 29. Experimentaluntersuchung über das Verhalten nicht leitender Körper unter dem Einflusse electrischer Kräfte; 30. Zur Theorie der elastische Nachwirkung; 31. Über den Zusammenhang zwischen der Drehung der Polarisationsebene und der Wellenlänge der verschiedenen Farben.

Boltzmann, Ludwig; Hasenöhrl, Friedrich

2012-08-01

86

ASTER Global DEM contribution to GEOSS demonstrates open data sharing  

NASA Astrophysics Data System (ADS)

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) remote sensing instrument on the Terra spacecraft has been acquiring images of Earth since launch in 1999. Throughout this time data products have been openly available to the general public through sites in the U.S. and Japan. As the ASTER mission matured, a spatially broad and temporally deep data archive was gradually established. With this extensive accumulation of Earth observations, it became possible to create a new global digital elevation product, the ASTER Global Digital Elevation Model (GDEM), using multi-temporal data, resulting in over 22,000 static 10 X 10 tiles. The ASTER GDEM was contributed by Japan’s Ministry of Economy Trade and Industry (METI) and the U.S. National Aeronautics and Space Administration (NASA) to the Global Earth Observation System of Systems (GEOSS) for distribution at no cost to users. As such, both METI and NASA desired to understand the uses of the ASTER GDEM, expressed as one of the GEOSS applications themes: disasters, health, energy, climate, water, weather, ecosystems, agriculture or biodiversity. This required both the registration of users, and restrictions on redistribution, to capture the intended use in terms of the GEOSS themes. The ASTER GDEM was made available to users worldwide via electronic download from the Earth Remote Sensing Data Analysis Center (ERSDAC) of Japan and from NASA’s Land Processes Distributed Active Archive Center (LP DAAC). During the first three months after product release, over 4 million GDEM tiles were distributed from the LP DAAC and ERSDAC. The ASTER GDEM release generated nearly 20,000 new user registrations in the NASA EOS ClearingHOuse (ECHO)/WIST and the ERSDAC systems. By the end of 2009, over 6.5 Million GDEM tiles were distributed by the LP DAAC and ERSDAC. Users have requested tiles over specific areas of interest as well as the entire dataset for global research. Intense global interest in the GDEM across all the GEOSS Societal Benefit areas was shown. The release of the global tiled research-grade DEM resulted in a significant increase in demand for ASTER elevation models, and increased awareness of related products. No cost access to these data has also promoted new applications of remotely sensed data, increasing their use across the full range of the GEOSS societal benefit areas. In addition, the simplified data access and greatly expanded pool of users resulted in a number of suggestions from researchers in many disciplines for possible enhancements to future versions of the ASTER GDEM. The broad distribution of the product can be directly attributed to the adoption of fundamental GEOSS data sharing principles, which are directed toward expanded access by minimizing time delay and cost, thus facilitating data use for education, research, and a range of other applications. The ASTER GDEM demonstrated the need and user demand for an improved global DEM product as well as the added benefit of not only “full and open” distribution, but “free and open” distribution.

Sohre, T.; Duda, K. A.; Meyer, D. J.; Behnke, J.; Nasa Esdis Lp Daac

2010-12-01

87

Ontwikkeling van de Gedragsobservatieschaal Psychomotorische therapie voor demente ouderen (GPMT-dem)  

Microsoft Academic Search

PDevelopment of the Behaviour observation scale for Psychomotor Therapy for elderly people with dementia (BPMT-dem).Reliability\\u000a and concurrent validity This article describes the development of the Behaviour observation scale for Psychomotor Therapy for elderly people with\\u000a dementia (BPMT-dem). This scale was developed in the late 1980s in order to evaluate the effect of psychomotor group therapy\\u000a on the cognitive, social, and

S. Lauriks; R. M. Dröes

2007-01-01

88

Calculating geomorphic indices in SE Asia using a SRTM derived DEM: a worked example from West Sulawesi, Indonesia  

NASA Astrophysics Data System (ADS)

Geomorphic indices like stream length gradient index (SL), mountain front sinuosity (Smf) and ratio of valley floor width to valley height (Vf) have previously been used to detect active tectonic features from observations of first order rivers and regional fault systems in areas where accurate topographic maps were available. However, areas in equatorial South East Asia present many problems, being remote, covered by dense forest and lacking full, detailed topographic surveys. Here a new approach is attempted, using results coming from the comparison of SRTM derived DEM's (SRTM-DEM) to traditional topographic 1:50,000 survey derived DEM's (TS-DEM). Neo-tectonic activity on the Palu-Koro fault in West Sulawesi was assessed using geomorphic indices calculated for major river systems (3rd up to 7th strahler order) derived from SRTM-DEM. Mountain front sinuosity indices are similar whether derived from SRTM-DEM or TS-DEM. Likewise, although the ranges differ, valley floor width to valley height ratios returns the same average value. The stream length index was influenced by systematic sensor errors in areas of extreme local relief on SRTM-DEM. A visual classification of river deflections and water gaps was performed in order to identify the best locations for wider application of geomorphic indices on the SRTM-DEM. While geomorphic calculations on SRTM-DEM's break down for flood plain valleys, yielding erroneous results, geomorphic indices may be successfully used to identify secondary fault systems in other parts of West Sulawesi.

Vecchiotti, Filippo

2008-10-01

89

Synergistic use of multitemporal RAMP, ICESat and GPS to construct an accurate DEM of the Larsemann Hills region, Antarctica  

NASA Astrophysics Data System (ADS)

An enhanced digital elevation model (DEM) of the Larsemann Hills region, east Antarctica, is constructed synergistically by using highly accurate ground-based GPS measurements, satellite-derived laser altimetry (GLAS/ICESat) and Radarsat Antarctic Mapping Project (RAMPv2) DEM-based point elevation dataset. Our DEM has a vertical accuracy of about 1.5 times better than RAMPv2 DEM and seven times better than GLAS/ICESAT-based DEM. The accuracy is improved by validating the RAMPv2 DEM elevation by supplementing with GLAS/ICESat and DGPS survey data, when compared to that of DEM constructed by using GLAS/ICESat or RAMPv2 alone. With the use of accurate GPS data as ground control points reference elevations, the DEM extracted is much more accurate with least mean RMSE of 34.5 m than that constructed by using a combination of GLAS/ICESat and RAMPv2 as true reference. The newly constructed DEM 7 achieves highest accuracy with the least average elevation difference of 0.27 m calculated using 46 ground reference points. Available DEMs of Antarctic region generated by using radar altimetry and the Antarctic Digital Database indicate elevation variations in the range of 50-100 m, which necessitates the generation of local DEM and its validation by using ground truth. This is our first attempt of fusing multi-temporal, multi-sensor and multi-source elevation data to generate a DEM of any part of Antarctica, in order to address the ice elevation change to infer the ice mass balance. Our approach focuses on the strengths of each elevation data source to produce an accurate DEM.

Jawak, Shridhar D.; Luis, Alvarinho J.

2012-08-01

90

The generation of DEM from ALOS/PRISM and ice volume change in Mt. Qomolangma region  

NASA Astrophysics Data System (ADS)

Calculation on glacier volume variations are still greatly limited by the vertical accurate of various data sources till now (Stevens et al., 2004). Therefore, one of the major methodological gaps in the observation of glaciers from space is the measurement of glacier volume changes (Kääb, 2008). Glacier volume changes needs an integrated study and correction on generated DEMs from multi-sources remote sensing data and evaluation of the vertical errors and accuracy. Here, we produced DEMs over mountain glaciers from ASTER and ALOS/PRISM on the northern slope of Mt. Qomolangma (hereafter called the Mt. Qomolangma region), also known as the Mt. Everest, located in the middle Himalayan Mountains, 27° 59-28° 11´N and 86° 44´- 86° 59´E. A series of digital images, include Aster images on 23 Oct 2003, ALOS/AVNIR-2 on 19 Jan 2007, ALOS/AVNIR-2 on 24 Oct 2008, 3 scenes of ALOS/PRISM on 04 Dec 2006, 1:50,000 topographic maps with contour interval of 20 m produced from aerial photographs acquired in 1974 and the 1:50,000 DEM (cell size: 25 m) generated from the topographic maps were used. The DEM was generated based on the three scenes from ALOS/PRISM images and PCI Orthoengine module. The process of DEM generation from ASTER images is very similar to that of ALOS/PRISM. The difference is that: only two images ASTER from nadir and backward views were used here. Table 1 The differences between generated DEMs and the 1:50,000 topographic maps in the non-glacierized area dem5wdemasterprism12_50mprism13_50mprism14_25mprism15_100mSRTM DEMASTER_GDEM Maximum 80.0 920.0 218.0 174.0 258.0 168.0 240.0 437.0 Minimum -123.0 -331.0 -297.0 -367.0 -459.0 -393.0 -315.0 -182.0 aveDEV 23.8 84.0 33.9 36.0 31.3 45.9 67.6 57.9 AVERAGE6.9 75.3 11.3 5.9 1.7 17.2 32.3 45.0 StDEV 30.5 128.0 55.7 59.4 60.6 64.4 85.8 77.2 RMSe 31.2 148.3 56.7 59.6 60.5 66.5 91.5 89.2 Compared various kinds of products of the generated DEMs in the non-glacierized area with the 1:50,000 topographic maps using 215 random points, we found that the mean difference of PRISM DEM to the topographic maps is 1.7 m. However, the mean difference of ASTER GDEM (ASTER_GDEM) is 45m, which is released Version 1 of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) on 29 June, 2009. Our result shows that the quality of ALOS/PRISM DEM is better than that of ASTER GDEM, and the calibrated ALOS/PRISM DEM based on the relationship between aspect and DEM difference was more accurate than the original generated one. Fig.1 The generated ASTER DEM on 23 Oct 2003 Fig.2 the generated PRISM DEM on 04 Dec 2006

Ye, Qinghua

2010-05-01

91

Off-limb (Spicule) DEM Distribution from SoHO/SUMER Observations  

NASA Astrophysics Data System (ADS)

In the present work we derive a Differential Emission Measure (DEM) distribution from a region dominated by spicules. We use spectral data from the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on-board the Solar Heliospheric Observatory (SoHO) covering the entire SUMER wavelength range taken off-limb in the Northern polar coronal hole to construct this DEM distribution using the CHIANTI atomic database. This distribution is then used to study the thermal properties of the emission contributing to the 171 Å channel in the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO). From our off-limb DEM we found that the radiance in the AIA 171 Å channel is dominated by emission from the Fe ix 171.07 Å line and has sparingly little contribution from other lines. The product of the Fe ix 171.07 Å line contribution function with the off-limb DEM was found to have a maximum at log T max (K)=5.8 indicating that during spicule observations the emission in this line comes from plasma at transition region temperatures rather than coronal. For comparison, the same product with a quiet Sun and prominence DEM were found to have a maximum at log T max (K)=5.9 and log T max (K)=5.7, respectively. We point out that the interpretation of data obtained from the AIA 171 Å filter should be done with foreknowledge of the thermal nature of the observed phenomenon. For example, with an off-limb DEM we find that only 3.6 % of the plasma is above a million degrees, whereas using a quiet Sun DEM, this contribution rises to 15 %.

Vanninathan, K.; Madjarska, M. S.; Scullion, E.; Doyle, J. G.

2012-10-01

92

Acute environmental toxicity and persistence of DEM, a chemical agent simulant: Diethyl malonate. [Diethyl malonate  

SciTech Connect

The purpose of the following chemical simulant studies is to assess the potential acute environmental effects and persistence of diethyl malonate (DEM). Deposition velocities for DEM to soil surfaces ranged from 0.04 to 0.2 cm/sec. For foliar surfaces, deposition velocities ranged from 0.0002 cm/sec at low air concentrations to 0.05 cm/sec for high dose levels. The residence times or half-lives of DEM deposited to soils was 2 h for the fast component and 5 to 16 h for the residual material. DEM deposited to foliar surfaces also exhibited biphasic depuration. The half-life of the short residence time component ranged from 1 to 3 h, while the longer time component had half-times of 16 to 242 h. Volatilization and other depuration mechanisms reduce surface contaminant levels in both soils and foliage to less than 1% of initial dose within 96 h. DEM is not phytotoxic at foliar mass loading levels of less than 10 {mu}m/cm{sup 2}. However, severe damage is evident at mass loading levels in excess of 17 {mu}g/cm{sup 2}. Tall fescue and sagebrush were more affected than was short-needle pine, however, mass loading levels were markedly different. Regrowth of tall fescue indicated that the effects of DEM are residual, and growth rates are affected only at higher mass loadings through the second harvest. Results from in vitro testing of DEM indicated concentrations below 500 {mu}g/g dry soil generally did not negatively impact soil microbial activity. Short-term effects of DEM were more profound on soil dehydrogenase activity than on soil phosphatase activity. No enzyme inhibition or enhancement was observed after 28 days in incubation. Results of the earthworm bioassay indicate survival to be 86 and 66% at soil doses of 107 and 204 {mu}g DEM/cm{sup 2}, respectively. At higher dose level, activity or mobility was judged to be affected in over 50% of the individuals. 21 refs., 10 figs., 15 tabs.

Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, Shu-mei W.; Van Voris, P.; Wentsel, R.S.

1990-05-01

93

Geomorphic change detection using historic maps and DEM differencing: The temporal dimension of geospatial analysis  

NASA Astrophysics Data System (ADS)

The ability to develop spatially distributed models of topographic change is presenting new capabilities in geomorphic research. High resolution maps of elevation change indicate locations, processes, and rates of geomorphic change, and provide a means of calibrating temporal simulation models. Methods of geomorphic change detection (GCD), based on gridded models, may be applied to a wide range of time periods by utilizing cartometric, remote sensing, or ground-based topographic survey data to measure volumetric change. Advantages and limitations of historical DEM reconstruction methods are reviewed with a focus on coupling them with subsequent DEMs to construct DEMs of difference (DoD), which can be created by subtracting one elevation model from another, to map erosion, deposition, and volumetric change. The period of DoD analysis can be extended to several decades if accurate historical DEMs can be generated by extracting topographic data from historical data and selecting areas where geomorphic change has been substantial. The challenge is to recognize and minimize uncertainties in data that are particularly elusive with early topographic data. This paper reviews potential sources of error in digitized topographic maps and DEMs. Although the paper is primarily a review of methods, three brief examples are presented at the end to demonstrate GCD using DoDs constructed from data extending over periods ranging from 70 to 90 years.

James, L. Allan; Hodgson, Michael E.; Ghoshal, Subhajit; Latiolais, Mary Megison

2012-01-01

94

Surface water hydrologic simulation of Qingshuijiang Watershed based on SRTM DEM  

NASA Astrophysics Data System (ADS)

The Digital Elevation Model (DEM) derived from NASA's Shuttle Radar Topography Mission is the most accurate nearglobal elevation model that is publicly available. The characteristics, advantages, and disadvantages of Shuttle Radar Topography Mission (SRTM) data sets were reviewed and discussed briefly. In order to verify the effect of applying SRTM data sets in surface water hydrologic simulation, a tool set named Arc Hydro Tools that is utilized to extract watershed characteristics was introduced, developed as an ArcGIS interface. The Qingshuijiang watershed in Guizhou Province, Southwest China, was taken as a case study. Using the tool set, the river network and subwatersheds of main tributaries were delineated from CGIAR- CSI SRTM 90 m DEM. By comparing the river network delineated from CGIAR-CSI SRTM 90 m DEM with the actual river network and comparing areas of the subwatersheds delineated from CGIAR-CSI SRTM 90 m DEM with the actual areas of the subwatersheds, it can be concluded that the delineated river network is generally in accord with the actual river network, as well as the areas of the delineated subwatersheds. The CGIAR-CSI SRTM 90 m DEM will promote the use of geospatial science and applications for digital topography analysis, especially for surface water hydrologic simulation.

Tang, Congguo; Liu, Congqiang

2008-11-01

95

Analysis of Triterpenoid Resinous Materials by Direct Exposure Electron Ionization Mass Spectrometry (DEMS): PCA Evaluation of Mass Spectral Data  

Microsoft Academic Search

A systematic study of triterpenic resinous materials (frankincense resin, mastic resin, dammar resin and birch bark pitch) was performed using direct exposure electron ionisation mass spectrometry (DE-MS). DE-MS provides a mass spectral fingerprint of organic materials in a few minutes which highlights the main components in the sample. The application of principal component analysis (PCA) on DE-MS data enabled us

F. Modugno; E. Ribechini; M. P. Colombini; M. Calderisi

96

Validation of DEMs for two-pass SAR differential interferometry — A case study in Wangfeng coal mine, Jiaozuo city  

Microsoft Academic Search

The two-pass method is widely used in the SAR differential interferometry (D-InSAR). It requires the external digital elevation model (DEM) as topographic phase signature to be removed from the interferogram. In the past decades, significant advance in global elevation modeling have been made with the release of the SRTM DEM and ASTER GDEM at no cost. These DEMs are often

Ping Wang; Zhangsheng Gao; Shaofeng Liu

2011-01-01

97

Robust DEM co-registration method for terrain changes assessment using least trimmed squares estimator  

NASA Astrophysics Data System (ADS)

Robust DEM co-registration for detecting terrain changes is an attractive but unresolved problem in both Remote Sensing and the Prevention and Mitigation of Hazards. Since robust DEM co-registration is an inherently very difficult problem, the algorithms developed are becoming more and more complicated. In this paper, a robust method for DEM co-registration is proposed, which integrates the least trimmed squares (LTS) estimator with the least Z-difference (LZD) algorithm. Moreover, a self-adaptive threshold based on the histogram of height differences is employed to identify the terrain changes automatically, which are the fundamental data for landslide assessment. The results of simulated experiments illustrate the robustness and accuracy of the new algorithm.

Zhang, Tonggang; Cen, Minyi

98

TanDEM-X: A radar interferometer with two formation-flying satellites  

NASA Astrophysics Data System (ADS)

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an innovative formation-flying radar mission that opens a new era in spaceborne radar remote sensing. The primary objective is the acquisition of a global digital elevation model (DEM) with unprecedented accuracy (12 m horizontal resolution and 2 m relative height accuracy). This goal is achieved by extending the TerraSAR-X synthetic aperture radar (SAR) mission by a second, TerraSAR-X like satellite (TDX) flying in close formation with TerraSAR-X (TSX). Both satellites form together a large single-pass SAR interferometer with the opportunity for flexible baseline selection. This enables the acquisition of highly accurate cross-track interferograms without the inherent accuracy limitations imposed by repeat-pass interferometry due to temporal decorrelation and atmospheric disturbances. Besides the primary goal of the mission, several secondary mission objectives based on along-track interferometry as well as new bistatic and multistatic SAR techniques have been defined, representing an important and innovative asset of the TanDEM-X mission. TanDEM-X is implemented in the framework of a public–private partnership between the German Aerospace Center (DLR) and EADS Astrium GmbH. The TanDEM-X satellite was successfully launched in June 2010 and the mission started its operational data acquisition in December 2010. This paper provides an overview of the TanDEM-X mission and summarizes its actual status and performance. Furthermore, results from several scientific radar experiments are presented that show the great potential of future formation-flying interferometric SAR missions to serve novel remote sensing applications.

Krieger, Gerhard; Zink, Manfred; Bachmann, Markus; Bräutigam, Benjamin; Schulze, Daniel; Martone, Michele; Rizzoli, Paola; Steinbrecher, Ulrich; Walter Antony, John; De Zan, Francesco; Hajnsek, Irena; Papathanassiou, Kostas; Kugler, Florian; Rodriguez Cassola, Marc; Younis, Marwan; Baumgartner, Stefan; López-Dekker, Paco; Prats, Pau; Moreira, Alberto

2013-08-01

99

LULC Classification and Topographic Correction of Landsat-7 ETM+ Imagery in the Yangjia River Watershed: the Influence of DEM Resolution  

PubMed Central

DEM-based topographic corrections on Landsat-7 ETM+ imagery from rugged terrain, as an effective processing techniques to improve the accuracy of Land Use/Land Cover (LULC) classification as well as land surface parameter retrievals with remotely sensed data, has been frequently reported in the literature. However, few studies have investigated the exact effects of DEM with different resolutions on the correction of imagery. Taking the topographic corrections on the Landsat-7 ETM+ images acquired from the rugged terrain of the Yangjiahe river basin (P.R. China) as an example, the present work systematically investigates such issues by means of two commonly used topographic correction algorithms with the support of different spatial resolution DEMs. After the pre-processing procedures, i.e. atmospheric correction and geo-registration, were applied to the ETM+ images, two topographic correction algorithms, namely SCS correction and Minnaert correction, were applied to assess the effects of different spatial resolution DEMs obtained from two sources in the removal of topographic effects and LULC classifications. The results suggested that the topographic effects were tremendously reduced with these two algorithms under the support of different spatial resolution DEMs, and the performance of the topographic correction with the 1:50,000-topographic-map DEM was similar to that achieved using SRTM DEM. Moreover, when the same topographic correction algorithm was applied the accuracy of LULC classification after topographic correction based on 1:50,000-topographic-map DEM was similar as that based on SRTM DEM, which implies that the 90 m SRTM DEM can be used as an alternative for the topographic correction of ETM+ imagery when high resolution DEM is unavailable.

Gao, Yongnian; Zhang, Wanchang

2009-01-01

100

DEM modeling and simulation of a catalytic gas–solid fluidized bed reactor: a spouted bed as a case study  

Microsoft Academic Search

A combined model of discrete element method (DEM) and mass transfer was developed for investigating the local mass transfer throughout a catalytic gas–solid fluidized bed reactor. The mathematical models are based on the equations of mass conservation coupling with the equations of gas and particle motion. The realistic model of DEM, which calculates the contact force acting on the individual

Sunun Limtrakul; Asada Boonsrirat; Terdthai Vatanatham

2004-01-01

101

Using Canonical Correspondence Analysis (CCA) to identify the most important DEM attributes for digital soil mapping applications  

Microsoft Academic Search

Topography has an important influence on the distribution of soils and their properties, especially in hilly lands, and related data are easily available, measurable and recognizable from digital elevation models (DEMs). To our knowledge, little attention has previously been paid to the effect of DEM attributes on the distribution of soils, using ordination methods. The objective of this study was

Mohsen Bagheri Bodaghabadi; M. H. Salehi; José A. Martínez-Casasnovas; J. Mohammadi; N. Toomanian; I. Esfandiarpoor Borujeni

2011-01-01

102

Behandlung der kongenitalen Skoliose mit dem Vertical-expandable-prosthetic-titanium-rib-Implantat  

Microsoft Academic Search

Zusammenfassung Kinder mit kongenitaler thorakaler Skoliose, assoziiert mit Rippenfusionen, einseitigen unsegmentierten Spangen und kontralateraler Halbwirbelbildung, haben ohne Therapie eine massive Kurvenprogression. Aufgrund der Annahme, dass die unsegmentierten Spangen nicht wachsen, wurde in der Vergangenheit früh operativ fusioniert, was eine verkürzte Wirbelsäulenlänge und ein vermindertes Lungenwachstum zur Folge hatte. Durch ein neues Operationsverfahren mit einem an den Rippen verankerten Längsimplantat, dem

A. K. Hell; F. Hefti; R. M. Campbell

2004-01-01

103

Comparison of DEM and experiment for a scale model SAG mill  

Microsoft Academic Search

Predictions of flow patterns in a 600-mm scale model SAG mill made using four classes of discrete element method (DEM) models are compared to experimental photographs. The accuracy of the various models is assessed using quantitative data on shoulder, toe and vortex center positions taken from ensembles of both experimental and simulation results. These detailed comparisons reveal the strengths and

Paul W Cleary; Rob Morrisson; Steve Morrell

2003-01-01

104

Effects of lidar post-spacing and DEM resolution to mean slope estimation  

Microsoft Academic Search

in Richland County, SC, USA, which share similar hydrologic characteristics. This research spatially sampled an airborne lidar dataset collected in 2000 at a 2 m nominal posting density to simulate lidar posting density at various post- spacings, from 2 m through 10 m. DEMs were created from the lidar observations at a corresponding cell size using spatial interpolation. Finally, using

T. Edwin Chow; Michael E. Hodgson

2009-01-01

105

Understanding the Hydrodynamics in a 2Dimensional Downer by CFD-DEM Simulation  

Microsoft Academic Search

The gas-solid flows in a 2-dimensional downer were simulated using a CFD-DEM method. The predicted macro-scale flow structure had good agreement with the experiments. The distinct clustering phenomena at meso-scale were revealed throughout the downer. Influences of the collision properties of the wall and the particles on the hydrodynamics in downer were investigated.

Yongzhi Zhao; Yi Cheng; Yulong Ding; Yong Jin

2007-01-01

106

90-METER DIGITAL ELEVATION MODEL (DEM) FOR THE MID-ATLANTIC INTEGRATED ASSESSMENT (MAIA) STUDY AREA  

EPA Science Inventory

This data set is a geographic information system (GIS) coverage of the 90-meter digital elevation model (DEM) for the United States Environmental Protection Agency (USEPA) Mid-Atlantic Integrated Assessment (MAIA) Project region. The coverage was produced using US Geological Su...

107

Numerical analysis of particle mixing characteristics in a single helical ribbon agitator using DEM simulation  

Microsoft Academic Search

Numerical analysis of three-dimensional motion of particles in a single helical ribbon agitator was carried out by means of the Discrete Element Method (DEM). To validate the computed results experiments were carried out with a cold scale model of 0.3 m inside diameter. Circulation time of particles in the agitator and the horizontal particle velocity distribution in the core region

Yasunobu Kaneko; Takeo Shiojima; Masayuki Horio

2000-01-01

108

387. D.E.M., Delineator December 1932 STATE OF CALIFORNIA; DEPARTMENT OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

387. D.E.M., Delineator December 1932 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; SUPERSTRUCTURE - WEST BAY CROSSING; TOWERS 2, 3, 5 & 6; BRACING DETAILS - LOWER DECK; CONTRACT NO. 6; DRAWING NO. 27 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

109

Robust multi-temporal DEM matching for debris-flow hazard assessment  

NASA Astrophysics Data System (ADS)

Debris-flow is a typical natural mountain hazards and it has caused a great number of casualties and property losses and it also is the most potential threat in mountainous The time variable information of the terrain surface contained in the multi-temporal DEM derived from the aerial- or satellite- remote sensing data sets is very valuable for solid Earth hazard assessment Such time variable information can be extracted only when DEMs obtained in different epochs are in the same coordinate frame However DEM obtained in different epochs may use various types of sensors or techniques And then there will be some bias in their coordinate systems more or less in case of no ground control points used Focusing on debris-flow hazard assessment this paper proposed a robust method for matching multi-temporal DEM by combining the least trimmed squares LTS estimator and least Z-difference LZD algorithm without any feature extraction or ground control points And some modifications are also made for improving the performance efficiency The experimental results illustrate that it is effective tool for debris-flow hazard assessment and validate its advantages

Zhang, T.; Wu, X.

110

Rapeseed impact against a flat surface: Physical testing and DEM simulation with two contact models  

Microsoft Academic Search

Efficient application of a discrete element method (DEM) in modeling the behavior of granular materials requires contact models that reflect real behavior and realistic material parameters. The mechanical behavior of materials of biological origin is strongly influenced by the moisture content, which changes the surface and mechanical properties of seed endosperm and influences the bulk behavior. Laboratory tests and numerical

M. Wojtkowski; J. Pecen; J. Horabik; M. Molenda

2010-01-01

111

Das jagdliche Hundewesen im Herzogtum Westfalen unter den Kurfürsten aus dem Hause Wittelsbach  

Microsoft Academic Search

Die höfische Jagd im Herzogtum Westfalen in der Zeit der Kurfürsten aus dem Hause Wittelsbach (1583–1761) erforderte eine große Zahl vielseitig veranlagter und ausgebildeter Hunde. Soweit diese durch das Personal des westfälischen Jagdamtes geführt wurden, bestritt die kurfürstliche Oberkellnerei in Arnsberg ihren Unterhalt. Die Kosten beliefen sich auf etwa 3000 Rtlr (Reichstaler) im Jahr. Im Zuge der Ausbildung der vollen

G. Sandgathe

1983-01-01

112

Application of DEM Data to Geological Interpretation: Thong Pha Phum Area, Thailand  

Microsoft Academic Search

The Digital Elevation Model (DEM) data can be created from GIS (Geographic Information System) data layers i.e. contour line and spot height. The result is expressed as grid data of which their quality controls are the quality of original data and grid size assigned for interpolation process. The grid data are further processed to be shaded relief image by illumination

Sunya Sarapirome; Adichat Surinkum; Pirat Saksutthipong

113

Challenges of simulating undrained tests using the constant volume method in DEM  

NASA Astrophysics Data System (ADS)

Liquefaction during earthquakes can cause significant infrastructural damage and loss of life, motivating a fundamental study of undrained sand response using discrete element modeling (DEM). Two methods are widely used in DEM for simulating the undrained response of soil. One approach is to numerically couple the DEM code with a fluid model. Alternatively, if the soil is fully saturated and water is assumed to be incompressible, the volume of the sample can be held constant to simulate an undrained test. The latter has the advantage of being computationally straightforward, but the assumption of a constant volume can cause some issues which are discussed in this paper. Depending on the contact model selected, extremely high deviatoric stresses and pore water pressures can be generated for dense samples using the constant volume approach which are not observed in corresponding laboratory tests. Furthermore the results of these constant volume simulations tend to be sensitive to the strain rate selected. The evolution of particle size distribution caused by grain crushing is also ignored in most undrained simulations. For these reasons, authors often restrict the extent of the data presented to physically-realistic ranges and report results in non-dimensional terms, e.g., using stress ratios (q/p') or stresses normalized by the initial confining pressure. This paper aims to highlight some of these issues, explore whether the constant volume approach is appropriate and make recommendations for future analysis of undrained soil behavior using DEM.

Hanley, Kevin J.; Huang, Xin; O'Sullivan, Catherine; Kwok, Fiona

2013-06-01

114

New land-based method for surveying sandy shores and extracting DEMs: the INSHORE system.  

PubMed

The INSHORE system (INtegrated System for High Operational REsolution in shore monitoring) is a land-base survey system designed and developed for the specific task of monitoring the evolution in time of sandy shores. This system was developed with two main objectives: (1) to produce highly accurate 3D coordinates of surface points (in the order of 0.02 to 0.03 m); and (2) to be extremely efficient in surveying a beach stretch of several kilometres. Previous tests have demonstrated that INSHORE systems fulfil such objectives. Now, the usefulness of the INSHORE system as a survey tool for the production of Digital Elevation Models (DEMs) of sandy shores is demonstrated. For this purpose, the comparison of DEMs obtained with the INSHORE system and with other relevant survey techniques is presented. This comparison focuses on the final DEM accuracy and also on the survey efficiency and its impact on the costs associated with regular monitoring programmes. The field survey method of the INSHORE system, based on profile networks, has a productivity of about 30 to 40 ha/h, depending on the beach surface characteristics. The final DEM precision, after interpolation of the global positioning system profile network, is approximately 0.08 to 0.12 m (RMS), depending on the profile network's density. Thus, this is a useful method for 3D representation of sandy shore surfaces and can permit, after interpolation, reliable calculations of volume and other physical parameters. PMID:21301958

Baptista, Paulo; Cunha, Telmo R; Matias, Ana; Gama, Cristina; Bernardes, Cristina; Ferreira, Oscar

2011-02-09

115

DemQSAR: predicting human volume of distribution and clearance of drugs.  

PubMed

In silico methods characterizing molecular compounds with respect to pharmacologically relevant properties can accelerate the identification of new drugs and reduce their development costs. Quantitative structure-activity/-property relationship (QSAR/QSPR) correlate structure and physico-chemical properties of molecular compounds with a specific functional activity/property under study. Typically a large number of molecular features are generated for the compounds. In many cases the number of generated features exceeds the number of molecular compounds with known property values that are available for learning. Machine learning methods tend to overfit the training data in such situations, i.e. the method adjusts to very specific features of the training data, which are not characteristic for the considered property. This problem can be alleviated by diminishing the influence of unimportant, redundant or even misleading features. A better strategy is to eliminate such features completely. Ideally, a molecular property can be described by a small number of features that are chemically interpretable. The purpose of the present contribution is to provide a predictive modeling approach, which combines feature generation, feature selection, model building and control of overtraining into a single application called DemQSAR. DemQSAR is used to predict human volume of distribution (VD(ss)) and human clearance (CL). To control overtraining, quadratic and linear regularization terms were employed. A recursive feature selection approach is used to reduce the number of descriptors. The prediction performance is as good as the best predictions reported in the recent literature. The example presented here demonstrates that DemQSAR can generate a model that uses very few features while maintaining high predictive power. A standalone DemQSAR Java application for model building of any user defined property as well as a web interface for the prediction of human VD(ss) and CL is available on the webpage of DemPRED: http://agknapp.chemie.fu-berlin.de/dempred/ . PMID:22101402

Demir-Kavuk, Ozgur; Bentzien, Jörg; Muegge, Ingo; Knapp, Ernst-Walter

2011-11-20

116

Inter-agency comparison of TanDEM-X baseline solutions  

NASA Astrophysics Data System (ADS)

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) is the first Synthetic Aperture Radar (SAR) mission using close formation flying for bistatic SAR interferometry. The primary goal of the mission is to generate a global digital elevation model (DEM) with 2 m height precision and 10 m ground resolution from the configurable SAR interferometer with space baselines of a few hundred meters. As a key mission requirement for the interferometric SAR processing, the relative position, or baseline vector, of the two satellites must be determined with an accuracy of 1 mm (1D RMS) from GPS measurements collected by the onboard receivers. The operational baseline products for the TanDEM-X mission are routinely generated by the German Research Center for Geosciences (GFZ) and the German Space Operations Center (DLR/GSOC) using different software packages (EPOS/BSW, GHOST) and analysis strategies. For a further independent performance assessment, TanDEM-X baseline solutions are generated at the Astronomical Institute of the University of Bern (AIUB) on a best effort basis using the Bernese Software (BSW).Dual-frequency baseline solutions are compared for a 1-month test period in January 2011. Differences of reduced-dynamic baseline solutions exhibit a representative standard deviation (STD) of 1 mm outside maneuver periods, while biases are below 1 mm in all directions. The achieved baseline determination performance is close to the mission specification, but independent SAR calibration data takes acquired over areas with a well known DEM from previous missions will be required to fully meet the 1 mm 1D RMS target. Besides the operational solutions, single-frequency baseline solutions are tested. They benefit from a more robust ambiguity fixing and show a slightly better agreement of below 1 mm STD, but are potentially affected by errors caused by an incomplete compensation of differential ionospheric path delays.

Jäggi, A.; Montenbruck, O.; Moon, Y.; Wermuth, M.; König, R.; Michalak, G.; Bock, H.; Bodenmann, D.

2012-07-01

117

AMES Stereo Pipeline Derived DEM Accuracy Experiment Using LROC-NAC Stereopairs and Weighted Spatial Dependence Simulation for Lunar Site Selection  

NASA Astrophysics Data System (ADS)

An accuracy assessment of AMES Stereo Pipeline derived DEMs for lunar site selection using weighted spatial dependence simulation and a call for outside AMES derived DEMs to facilitate a statistical precision analysis.

Laura, J. R.; Miller, D.; Paul, M. V.

2012-03-01

118

A new 100-m Digital Elevation Model of the Antarctic Peninsula derived from ASTER Global DEM: methods and accuracy assessment  

NASA Astrophysics Data System (ADS)

A high resolution surface topography Digital Elevation Model (DEM) is required to underpin studies of the complex glacier system on the Antarctic Peninsula. A complete DEM with better than 200 m pixel size and high positional and vertical accuracy would enable mapping of all significant glacial basins and provide a dataset for glacier morphology analyses. No currently available DEM meets this specification. We present a new 100-m DEM of the Antarctic Peninsula (63-70° S), based on ASTER Global Digital Elevation Model (GDEM) data. The raw GDEM products are of high-quality on the rugged terrain and coastal-regions of the Antarctic Peninsula and have good geospatial accuracy, but they also contain large errors on ice-covered terrain and we seek to minimise these artefacts. Conventional data correction techniques do not work so we have developed a method that significantly improves the dataset, smoothing the erroneous regions and hence creating a DEM with a pixel size of 100 m that will be suitable for many glaciological applications. We evaluate the new DEM using ICESat-derived elevations, and perform horizontal and vertical accuracy assessments based on GPS positions, SPOT-5 DEMs and the Landsat Image Mosaic of Antarctica (LIMA) imagery. The new DEM has a mean elevation difference of +3 m (±26 m RMSE) from ICESat, and a horizontal error of less than 2 pixels, although elevation accuracies are lower on mountain peaks and steep-sided slopes. The correction method significantly reduces errors on low relief slopes and therefore the DEM can be regarded as suitable for topographical studies such as measuring the geometry and ice flow properties of glaciers on the Antarctic Peninsula. The DEM is available for download from the NSIDC website: dems/datasets.html="_blank">http://nsidc.org/data/dems/datasets.html (http://dx.doi.org/10.5060/D47P8W9D).

Cook, A. J.; Murray, T.; Luckman, A.; Vaughan, D. G.; Barrand, N. E.

2012-05-01

119

DEM simulation of fluidized beds for gas-phase olefin polymerization  

Microsoft Academic Search

The temperature behavior of particles and gas in a fluidized bed reactor for polyolefin (PO, i.e., polyethylene (PE) and polypropylene (PP)) production was numerically analyzed based on the Discrete Element Method (DEM). Simulation was performed using a numerical code (modified SAFIRE code) by modifying SAFIRE ver.1 of Mikami, Kamiya and Horio (1998, Chemical Engineering Science, 53, 1927–1940) by incorporating the

Yasunobu Kaneko; Takeo Shiojima; Masayuki Horio

1999-01-01

120

EVALUATION OF THE PERFORMANCE OF DEM INTERPOLATION ALGORITHMS FOR LIDAR DATA  

Microsoft Academic Search

Airborne light detection and ranging (LiDAR) is one of the most effective means for high quality terrain data acquisition. The high-accuracy and high-density LiDAR data makes it possible to model terrain surface in more detail. Using LiDAR data for DEM generation is becoming a standard practice in the spatial science community. Of the three commonly used digital elevation models (e.g.,

Xiaoye Liu; Zhenyu Zhang; Jim Peterson

121

Assessing Uncertainties in Derived Slope and Aspect from a Grid DEM  

Microsoft Academic Search

Digital elevation data are the most frequently used for computer-based terrain analysis and they form an integral part of\\u000a today’s GIS data analysis capability. For most GIS-based environmental studies, primary topographic parameters such as slope,\\u000a aspect, and drainage network are often required for specific environmental models. While derived from digital elevation data,\\u000a particularly the grid-based Digital Elevation Models (DEM), the

ZHOU Qiming; LIU Xuejun

122

Identification of Flow-Routing Sequence from DEMs Based on Quicksort  

Microsoft Academic Search

As most of the distributed hydrological models are based on the channel networks extracted from digital elevation models, for distributed modeling to be implemented, the channel networks must be ranked to determine a flow-routing sequence. In this paper, an algorithm identifying flow-routing sequence from DEMs by the Quicksort rank method is presented. Working recursively via a divide-and-conquer method, the Quicksort

Bang Yang; Liliang Ren; Furong Chen; Xiaofan Liu

2009-01-01

123

Asperity Degradation and Damage in the Direct Shear Test: A Hybrid FEM\\/DEM Approach  

Microsoft Academic Search

Summary  This paper investigates the processes of joint surface damage and near-surface intact rock tensile failure using a hybrid\\u000a FEM\\/DEM code. Selected Barton and Choubey JRC profiles were simulated in direct shear tests and the surface damage mechanisms\\u000a investigated in terms of joint surface wear or tensile fracturing of intact rock along the joint plane. Shear strength and\\u000a displacement profiles for

A. Karami; D. Stead

2008-01-01

124

The kinetic H D isotope effect in electroless copper plating. A DEMS study  

Microsoft Academic Search

DEMS studies in electroless copper plating solution were carried out using a thin-layer flow-through cell within the electrode potential range ? 1.0 V to 0.7 V (SHE). The effect of HD substitution in both formaldahyde and water on the rate of anodic oxidation of formaldehyde to formate was investigated by on-line mass spectrometry in electroless copper plating solutions and in

Zenonas Jusys; Algirdas Vaškelis

1997-01-01

125

Electrochemical reactions of benzoic acid on platinum and palladium studied by DEMS. Comparison with benzyl alcohol  

Microsoft Academic Search

The electrochemical reactivity of benzoic acid on porous platinum and palladium electrodes has been studied by cyclic voltammetry and differential electrochemical mass spectrometry (DEMS) in aqueous 0.1 M HClO4. The objective of this work is to investigate the adsorption processes and the reactivity of this compound on different noble metals, in order to compare these results with those obtained for

Ricardo M Souto; José L Rodr??guez; Luis Fernández-Mérida; Elena Pastor

2000-01-01

126

Multitemporal DEM co-registering for detecting terrain changes using local invariant patches  

NASA Astrophysics Data System (ADS)

Debris-flow is one of the major geological hazards in southwest China, which are a global threat and happen and results in thousands deaths and injuries and billions of dollars in damages globally. Automatic multi-temporal DEM coregistration for detecting terrain changes is an attractive but inherent very difficult research topic. Many methods have been proposed in recent years, but all of them can only deal with DEM with limited percentage of terrain changes. However, in landslide and debris-flow areas, the rate of terrain changes is very high. To solve such a problem, a new method for detecting terrain changes using local invariant patches is proposed in this paper. According to the character of the debris-flow activities, the peak and ridge are rarely affected. From where some invariant patches can be extracted associated by the feature extraction method. After co-registration these invariant patches, a coarse matching can be reached. Therefore, two DEM can be compared after applying this coarse matching. With an appropriate threshold, most of terrain changes can be eliminated, and then a fine matching can be anticipated reasonable. The accuracy terrain changes will be derived. The new method can estimate the terrain changes quantificationally and automatically, and verifies by a real application. The experimental results illustrate the proposed method is of robust, accuracy, and timeefficiency.

Zhang, Tonggang; Cen, Minyi; Liu, Guoxiang; Feng, Yicong; Ren, Zizhen; Yang, Ronghao

2009-06-01

127

A novel algorithm with heuristic information for extracting drainage networks from raster DEMs  

NASA Astrophysics Data System (ADS)

Extracting drainage networks from raster DEMs is a necessary requirement in almost all hydrological and environmental analyses and determining surface water flow direction is a fundamental problem. In a raster environment, surface water flow direction of each cell can be directed to the neighboring cell with the steepest downslope drop (The basic D8, deterministic eight-neighbour method), which is inadequate for routing flow over pits and flats. Several improved algorithms are proposed to find the outlet of pits and flats, which typically use entirely different procedures for processing pits and flats. Being different from others, this paper presents a new method to route flow through the pits and flats by searching for the outlet using the heuristic information to compensate inadequate searching information of other methods. Heuristic information can reveal the general trend of the DEM and help the proposed algorithm find the outlet of pits and flats accurately. Furthermore, the proposed algorithm can handle pits and flats effectively in one procedure. This new algorithm is implemented in Pascal and experiments are carried out on actual DEM data. It can be seen from the comparison of the drainage networks generated by the proposed algorithm and ArcGIS 9.2, the proposed algorithm with heuristic information can get a closer match result with existing river networks and avoid the generation of the unrealistic parallel drainage lines, unreal drainage lines and spurious terrain features.

Yang, W.; Hou, K.; Yu, F.; Liu, Z.; Sun, T.

2010-01-01

128

Energy Crisis in the Superbubble DEM L192 (N51D)  

NASA Astrophysics Data System (ADS)

Superbubbles surrounding OB associations provide ideal laboratories in which to study the stellar energy feedback problem, because the stellar energy input can be estimated from the observed stellar content of the OB associations, and the interstellar thermal and kinetic energies of superbubbles are well defined and easy to observe. We have used DEM L192, also known as N51D, to carry out a detailed case study of the energy budget in a superbubble, and we find that the expected amount of stellar mechanical energy injected into the interstellar medium, (18+/-5)×1051 ergs, exceeds the amount of thermal and kinetic energies stored in the superbubble, (6+/-2)×1051 ergs. Clearly, a significant fraction of the stellar mechanical energy must have been converted into other forms of energy. The X-ray spectrum of the diffuse emission from DEM L192 requires a power-law component to explain the featureless emission at 1.0-3.0 keV. The origin of this power-law component is unclear, but it may be responsible for the discrepancy between the stellar energy input and the observed interstellar energy in DEM L192.

Cooper, Randall L.; Guerrero, Martín A.; Chu, You-Hua; Chen, C.-H. Rosie; Dunne, Bryan C.

2004-04-01

129

Research on terrain analysis of mass DEM data based on grid computing  

NASA Astrophysics Data System (ADS)

With the development of spatial data acquisition technology, the surveying departments have acquired mass DEM Data at terabyte-scale. The current GIS software and computing methods can not meet the demand of analyzing and mining these mass data. A new kind of computing infrastructure is expected to support distributed access to and analysis of these datasets by potentially thousands of users. Grid computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications, and , in some cases, high-performance orientation. This paper focuses on the key problems of terrain analysis of mass DEM data based on grid computing and makes the following contributions. First, we review the current terrain analysis algorithms based on DEM data and analysis the parallel algorithms. Next, we proposed a DTA (Digital Terrain Analysis) grid and analyze the architecture and key problems of the DTA grid. Finally, the experiment system developed based on grid middleware is introduced.

Xie, Jibo; Gong, Jianya

2005-11-01

130

Automatic DEM generation from aerial lidar data using multiscale support vector machines  

NASA Astrophysics Data System (ADS)

Automatic generation of DEM from LIDAR point clouds is attractive to photogrammetry community. This paper explores the possibility of using Multi-Scale SVM technique to classify untextured Lidar data into ground points and non-ground points so that DEM can be generated efficiently. First, irregular LIDAR point clouds are rasterized and a set of features including local height variation, min/max slope, plane flatness/direction and laser return intensity are generalized as well. Second, we establish Multi-Scale SVM classification levels by implementing SVM classier at different scale-space of Lidar data and one defined conditional probabilistic model is computed to make final classification. Finally, adaptive medium filter is implemented to smooth the isolated ground points mixed with little non-ground points and because the removal of non-ground points left quite a lot "blank holes", we further triangulate smoothed non-ground points to generate DEM automatically. The experimental results prove to be quite significant for real applications.

Wu, Jun; Liu, Lijuan; Liu, Rong

2011-11-01

131

A new method of surface modeling and its application to DEM construction  

NASA Astrophysics Data System (ADS)

A new method of surface modelling based on the fundamental theorem of surfaces (SMTS) is presented. Eight different test surfaces are employed to comparatively analyze the simulation errors of SMTS and the classical methods of surface modeling in GIS, including TLI (triangulated irregular network with linear interpolation), SPLINE, IDW (inverse distance weighted) and KRIGING. Numerical tests show that SMTS is much more accurate than the classical methods. SMTS theoretically gives a solution to the error problem that has long troubled DEM construction. As a real-world example, SMTS is used to construct a DEM of the Da-Fo-Si coal mine in Shaan-Xi Province, China. Its root mean square error (RMSE) is compared with those of DEMs constructed by the four classical methods. The results show that although SMTS also has a higher accuracy in the real-world example, the improvement of accuracy is less distinct than that expected from the numerical tests. The accuracy loss seems to be caused by location differences between sampling points and the central points of lattices of the simulated surfaces. Two alternative ways are proposed to solve this problem.

Yue, Tian-Xiang; Du, Zhen-Ping; Song, Dun-Jiang; Gong, Yun

2007-10-01

132

DEM modelling, vegetation characterization and mapping of aspen parkland rangeland using LIDAR data  

NASA Astrophysics Data System (ADS)

Detailed geographic information system (GIS) studies on plant ecology, animal behavior and soil hydrologic characteristics across spatially complex landscapes require an accurate digital elevation model (DEM). Following interpolation of last return LIDAR data and creation of a LIDAR-derived DEM, a series of 260 points, stratified by vegetation type, slope gradient and off-nadir distance, were ground-truthed using a total laser station, GPS, and 27 interconnected benchmarks. Despite an overall mean accuracy of +2 cm across 8 vegetation types, it created a RMSE (square root of the mean square error) of 1.21 m. DEM elevations were over-estimated within forested areas by an average of 20 cm with a RMSE of 1.05 m, under-estimated (-12 cm, RMSE = 1.36 m) within grasslands. Vegetation type had the greatest influence on DEM accuracy, while off-nadir distance (P = 0.48) and slope gradient (P = 0.49) did not influence DEM accuracy; however, the latter factors did interact (P < 0.10) to effect accuracy. Vegetation spatial structure (i.e., physiognomy) including plant height, cover, and vertical or horizontal heterogeneity, are important factors influencing biodiversity. Vegetation over and understory were sampled for height, canopy cover, and tree or shrub density within 120 field plots, evenly stratified by vegetation formation (grassland, shrubland, and aspen forest). Results indicated that LIDAR data could be used for estimating the maximum height, cover, and density, of both closed and semi-open stands of aspen (P < 0.001). However, LIDAR data could not be used to assess understory (<1.5 m) height within aspen stands, nor grass height and cover. Recognition and mapping of vegetation types are important for rangelands as they provide a basis for the development and evaluation of management policies and actions. In this study, LIDAR data were found to be superior to digital classification schedules for their mapping accuracy in aspen forest and grassland, but not shrubland. No single classification schedule created a high classification accuracy map for all types; however, the integration of LIDAR data and digital images achieved maps with corresponding overall accuracies of 91% and 83.9% with 3 and 8 classes of vegetation.

Su, Guangquan

133

LULC Classification and Topographic Correction of Landsat7 ETM+ Imagery in the Yangjia River Watershed: the Influence of DEM Resolution  

Microsoft Academic Search

DEM-based topographic corrections on Landsat-7 ETM+ imagery from rugged terrain, as an effective processing techniques to improve the accuracy of Land Use\\/Land Cover (LULC) classification as well as land surface parameter retrievals with remotely sensed data, has been frequently reported in the literature. However, few studies have investigated the exact effects of DEM with different resolutions on the correction of

Yongnian Gao; Wanchang Zhang

2009-01-01

134

On the COSMO-SkyMed Exploitation for Interferometric DEM Generation  

NASA Astrophysics Data System (ADS)

DEM products for Earth observation space-borne applications are being to play a role of increasing importance due to the new generation of high resolution sensors (both optical and SAR). These new sensors demand elevation data for processing and, on the other hand, they provide new possibilities for DEM generation. Till now, for what concerns interferometric DEM, the Shuttle Radar Topography Mission (SRTM) has been the reference product for scientific applications all over the world. SRTM mission [1] had the challenging goal to meet the requirements for a homogeneous and reliable DEM fulfilling the DTED-2 specifications. However, new generation of high resolution sensors (including SAR) pose new requirements for elevation data in terms of vertical precision and spatial resolution. DEM are usually used as ancillary input in different processing steps as for instance geocoding and Differential SAR Interferometry. In this context, the recent SAR missions of DLR (TerraSAR-X and TanDEM-X) and ASI (COSMO-SkyMed) can play a promising role thanks to their high resolution both in space and time. In particular, the present work investigates the potentialities of the COSMO/SkyMed (CSK) constellation for ground elevation measurement with particular attention devoted to the impact of the improved spatial resolution wrt the previous SAR sensors. The recent scientific works, [2] and [3], have shown the advantages of using CSK in the monitoring of terrain deformations caused by landslides, earthquakes, etc. On the other hand, thanks to the high spatial resolution, CSK appears to be very promising in monitoring man-made structures, such as buildings, bridges, railways and highways, thus enabling new potential applications (urban applications, precise DEM, etc.). We present results obtained by processing both SPOTLIGHT and STRIPMAP acquisitions through standard SAR Interferometry as well as multi-pass interferometry [4] with the aim of measuring ground elevation. Acknowledgments Work supported by ASI (Agenzia Spaziale Italiana) in the framework of the project "AO-COSMO Project ID-1462 - Feasibility of possible use of COSMO/SkyMed in bistatic SAR Earth observation - ASI Contract I/063/09/0". References [1] B. Rabus, M. Eineder, A. Roth, and R. Bamler, "The Shuttle Radar Topography Mission-A new class of digital elevation models acquired by spaceborne radar," ISPRS J. Photogramm. Remote Sens., vol. 57, no. 4, pp. 241-262, Feb. 2003. [2] F. BOVENGA, D. O. NITTI, R. NUTRICATO, M. T. CHIARADIA, "C- and X-band multi-pass InSAR analysis over Alpine and Apennine regions". In Proceedings of the European Space Agency Living Planet Symposium, June 28 - July 2, 2010, Bergen, Norway. [3] D. REALE, D. O. NITTI, D. PEDUTO, R. NUTRICATO, F. BOVENGA, G. FORNARO, "Postseismic Deformation Monitoring With The COSMO/SKYMED Constellation". IEEE Geoscience Remote Sensing Letters, 2011. DOI: 10.1109/LGRS.2010.2100364 [4] Nitti, D.O., Nutricato, R., Bovenga, F., Conte, D., Guerriero, L. & Milillo, G., "Quantitative Analysis of Stripmap And Spotlight SAR Interferometry with CosmoSkyMed constellation.", Proceedings if IEEE IGARSS 2009, July 13-17, 2009. Cape Town, South Africa.

Teresa, C. M.; Raffaele, N.; Oscar, N. D.; Fabio, B.

2011-12-01

135

Pellagra, Entstanden Nach Behandlung des Plummer-Vinson-Syndroms mit Riboflavin  

Microsoft Academic Search

Bei einer Patientin, die längere Zeit hindurch mit Riboflavininjektionen behandelt wurde, entwickelten sich pellagröse Veränderungen der Haut. Die Möglichkeit eines kausalen Zusammenhanges zwischen der Riboflavinzufuhr und den pellagrösen Hautveränderungen wird diskutiert.

Jørgen Bichel; E. Meulengracht

1941-01-01

136

Stream Morphologic Measurements from Airborne Laser Swath Mapping: Comparisons with Field Surveys, Traditional DEMs, and Aerial Photographs  

NASA Astrophysics Data System (ADS)

Precise measurement of stream morphology over entire watersheds is one of the great research opportunities provided by airborne laser swath mapping (ALSM). ALSM surveys allow for rapid quantification of factors, such as channel width and gradient, that control stream hydraulic and ecologic properties. We compare measurements from digital elevation models (DEMs) derived from ALSM data collected by the National Center for Airborne Laser Mapping (NCALM) to field surveys, traditional DEMs (rasterized from topographic maps), and aerial photographs. The field site is in the northern Black Mountains in arid Death Valley National Park (California). The area is unvegetated, and therefore is excellent for testing DEM analysis methods because the ALSM data required minimal filtering, and the resulting DEM contains relatively few unphysical sinks. Algorithms contained in geographic information systems (GIS) software used to extract stream networks from DEMs yield best results where streams are steep enough for resolvable pixel-to-pixel elevation change, and channel width is on the order of pixel resolution. This presents a new challenge with ALSM-derived DEMs because the pixel size (1 m) is often an order of magnitude or more smaller than channel width. We find the longitudinal profile of Gower Gulch in the northern Black Mountains (~4 km total length) extracted using the ALSM DEM and a flow accumulation algorithm is 14% longer than a traditional 10-m DEM, and 13% longer than a field survey. These differences in length (and therefore gradient) are due to the computed channel path following small-scale topographic variations within the channel bottom that are not relevant during high flows. However, visual analysis of shaded-relief images created from high-resolution ALSM data is an excellent method for digitizing channel banks and thalweg paths. We used these lines to measure distance, elevation, and width. In Gower Gulch, the algorithm-derived profile is 10% longer than that measured by tracing the thalweg on the ALSM imagery. By obtaining longitudinal profiles and widths from the same dataset, ALSM represents a major step forward from previous remote-sensing morphologic analyses, in which profiles are measured using traditional DEMs or topographic maps, and widths from aerial photographs. These combined analyses would be particularly powerful in regions of low relief and/or wide channels were traditional DEMs have limited utility.

Snyder, N. P.; Schultz, L. L.

2005-12-01

137

A new 100-m Digital Elevation Model of the Antarctic Peninsula derived from ASTER Global DEM: methods and accuracy assessment  

NASA Astrophysics Data System (ADS)

A high resolution surface topography Digital Elevation Model (DEM) is required to underpin studies of the complex glacier system on the Antarctic Peninsula. A complete DEM with better than 200 m pixel size and high positional and vertical accuracy would enable mapping of all significant glacial basins and provide a dataset for glacier morphology analyses. No currently available DEM meets these specifications. We present a new 100-m DEM of the Antarctic Peninsula (63-70° S), based on ASTER Global Digital Elevation Model (GDEM) data. The raw GDEM products are of high-quality on the rugged terrain and coastal-regions of the Antarctic Peninsula and have good geospatial accuracy, but they also contain large errors on ice-covered terrain and we seek to minimise these artefacts. Conventional data correction techniques do not work so we have developed a method that significantly improves the dataset, smoothing the erroneous regions and hence creating a DEM with a pixel size of 100 m that will be suitable for many glaciological applications. We evaluate the new DEM using ICESat-derived elevations, and perform horizontal and vertical accuracy assessments based on GPS positions, SPOT-5 DEMs and the Landsat Image Mosaic of Antarctica (LIMA) imagery. The new DEM has a mean elevation difference of -4 m (± 25 m RMSE) from ICESat (compared to -13 m mean and ±97 m RMSE for the original ASTER GDEM), and a horizontal error of less than 2 pixels, although elevation accuracies are lower on mountain peaks and steep-sided slopes. The correction method significantly reduces errors on low relief slopes and therefore the DEM can be regarded as suitable for topographical studies such as measuring the geometry and ice flow properties of glaciers on the Antarctic Peninsula. The DEM is available for download from the NSIDC website: http://nsidc.org/data/nsidc-0516.html (doi:10.5060/D47P8W9D).

Cook, A. J.; Murray, T.; Luckman, A.; Vaughan, D. G.; Barrand, N. E.

2012-10-01

138

A DEM model for soft and hard rocks: Role of grain interlocking on strength  

NASA Astrophysics Data System (ADS)

The Discrete Element Method (DEM) is increasingly used to simulate the behavior of rock. Despite their intrinsic capability to model fracture initiation and propagation starting from simple interaction laws, classical DEM formulations using spherical discrete elements suffer from an intrinsic limitation to properly simulate brittle rock behavior characterized by high values of UCS/TS ratio associated with non-linear failure envelopes, as observed for hard rock like granite. The present paper shows that the increase of the interaction range between the spherical discrete elements, which increases locally the density of interaction forces (or interparticle bonds), can overcome this limitation. It is argued that this solution represents a way to implicitly take into account the degree of interlocking associated to the microstructural complexity of rock. It is thus shown that increasing the degree of interlocking between the discrete elements which represent the rock medium, in addition to enhancing the UCS/TS ratio, results in a non-linear failure envelop characteristic of low porous rocks. This approach improves significantly the potential and predictive capabilities of the DEM for rock modeling purpose. A special emphasis is put on the model ability to capture the fundamental characteristics of brittle rocks in terms of fracture initiation and propagation. The model can reproduce an essential component of brittle rock failure, that is, cohesion weakening and frictional strengthening as a function of rock damage or plastic strain. Based on model predictions, it is finally discussed that frictional strengthening may be at the origin of the brittle ductile transition occurring at high confining pressures.

Scholtès, Luc; Donzé, Frédéric-Victor

2013-02-01

139

Identification of Quaternary Faults in Southwest Western Australia Using DEM-based Hill Shading  

NASA Astrophysics Data System (ADS)

In Australia, the extreme infrequency of large earthquake events means that the historic record of seismicity is poorly suited to the task of assessing seismic hazard. Paleoseismological investigations provide the only viable avenue to obtain constraints on the recurrence intervals of large and damaging earthquakes. However, the prehistoric record is compromised by difficulties related to finding direct evidence for large earthquakes (e.g. fault scarps), which may be subtle or relatively short-lived in the landscape. In recent times, high resolution digital elevation models (DEMs) have emerged as an important tool for defining and mapping of areas of probable elevated earthquake hazard. An examination of selected Shuttle Radar Tomography Mission (SRTM) 3 second DEM tiles and a 10 m resolution Department of Land Administration DEM has resulted in the identification of seven previously unrecognised fault scarps of probably Quaternary age in the southwest of Western Australia (SWWA). This doubles the number of Quaternary scarps known from SWWA, and is an important advance in defining areas prone to large earthquakes. The new features range in length from ~15 km to over 45 km, and from ~1.5 m to 7.5 m in height. As might be expected given the prevailing E-W regional compressive stress direction, the scarps are dominantly north-trending. However, most scarps are also arranged within a broad ESE-trending belt. This belt aligns with oceanic transform faults to the west of Australia relating to the break up with India. Of the fourteen scarps only two have been the subject of detailed palaeoseismic investigation to determine recurrence for large events. Ongoing research seeks to characterise seismicity on these scarps and further explore their large-scale relationship to each other, and to the architecture of the Australian plate. This work has the potential to greatly enhance our understanding of the drivers behind seismicity in intraplate Australia, and hence improve estimates of seismic hazard.

Clark, D.; Collins, C. D.

2004-12-01

140

Collection of medical drug information in pharmacies: Drug Event Monitoring (DEM) in Japan.  

PubMed

To establish a system for collecting and reporting information from community pharmacists such as that on adverse effects, the Japan Pharmaceutical Association (JPA) conducts Drug Event Monitoring (DEM). In the fiscal year 2002, a survey was carried out to clarify the incidence of sleepiness due to antiallergic drugs. The investigated active ingredients were ebastine, fexofenadine hydrochloride, cetirizine hydrochloride, and loratadine. Community pharmacists asked the following question to patients who visited their pharmacies: "Have you ever become sleepy after taking this drug?" During a 4-week survey period, reports of 94256 cases were collected. To evaluate the incidence of sleepiness, we analyzed cases in which reports showed alleged absence of concomitant oral drugs, and drug use in conformity with the dose and method described in package inserts. The incidence of sleepiness was significantly different among the drugs (chi(2)-test, p<0.001). The observed incidences of sleepiness due to the drugs (8.8-20.5%) were higher than those described in each package insert (1.8-6.35%). This may be because an active question was used ("Have you ever become sleepy after taking this drug?"). Active intervention by pharmacists may be useful for collecting more information on improvement in the QOL of patients and safety. In addition, the pharmacists were asked to report events other than "sleepiness" in the free description column of the report. Some symptoms not described in the package inserts were reported, suggesting that DEM may lead to the discovery of new adverse effects. These results suggest that community pharmacists have a good opportunity to collect information in DEM, and safety information such as that on adverse effects can be obtained from pharmacies. PMID:15997212

Hayashi, Sei-ichiro; Nanaumi, Akira; Akiba, Yasuji; Komiyama, Takako; Takeuchi, Koichi

2005-07-01

141

Artificial neural network classification of Karst rocky desertification degree using SPOT satellite imagery and DEM data  

NASA Astrophysics Data System (ADS)

Karst rocky desertification is a significant environmental and ecological problem in Southwest China. In this paper, the spectral information, spatial context and topography information were utilized to synthetically discriminate the Karst rocky desertification degree, which are derived from The SPOT satellite imagery and DEM. By the back-propagation neural network, we proposed the classification model structure and classified the rocky desertification levels in Du'an County of Guangxi province, China. The results verified the classification model of Karst rocky desertification degree is efficient and accurate.

Lin, Meng; Hu, Baoqing; Wu, Lianglin

2011-11-01

142

DEM simulation of bead packs as fillers in thin-wall tube push bending process  

NASA Astrophysics Data System (ADS)

The bead pack, as filler, has been introduced to thin-wall tube bending process. The pressure transmission, flowing and deformation characteristics of different bead pack systems are simulated during tube push bending with discrete element method (DEM). The simulations are conducted respectively in different conditions including friction and frictionless, bead pack systems with the same size and different sizes. As a result, the friction coefficient is the major parameter in the deformation of bead packs. Consequently the bead packs can be used as fillers to improve thin-walled tube push bending process, especially the ultra-thin-wall tube bending.

Liu, Hai; Zhang, Shi-Hong; Cheng, Ming; Song, Hong-Wu; Liu, Jin-Song

2013-05-01

143

DEM-based spatial discretization and parameter database design for distributed hydrological model  

NASA Astrophysics Data System (ADS)

The spatial heterogeneities of hydrological parameters in watersheds with limited extents should be accounted by the distributed hydrological model. Dongting Lake is selected as the study area and divided into 19759 hydrological response units based on DEM according to the concept of drainage density. Each unit has one land-use type and one soil type. The hydrological response units are utilized as the minimum units in simulations of hydrological processes and a parameter database of the distributed hydrological model is designed under the support of GIS. The parameters are managed with layers in the database. The structure of the database is helpful for organizing and updating the parameters.

Zhang, Xu; Zhou, Tinggang; Zheng, Jianrui

2009-10-01

144

DEM L241, a Supernova Remnant Containing a High-mass X-Ray Binary  

NASA Astrophysics Data System (ADS)

A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M ?

Seward, F. D.; Charles, P. A.; Foster, D. L.; Dickel, J. R.; Romero, P. S.; Edwards, Z. I.; Perry, M.; Williams, R. M.

2012-11-01

145

Comparison of elevation derived from insar data with dem from topography map in Son Dong, Bac Giang, Viet Nam  

NASA Astrophysics Data System (ADS)

Digital Elevation Models (DEMs) are used in many applications in the context of earth sciences such as in topographic mapping, environmental modeling, rainfall-runoff studies, landslide hazard zonation, seismic source modeling, etc. During the last years multitude of scientific applications of Synthetic Aperture Radar Interferometry (InSAR) techniques have evolved. It has been shown that InSAR is an established technique of generating high quality DEMs from space borne and airborne data, and that it has advantages over other methods for the generation of large area DEM. However, the processing of InSAR data is still a challenging task. This paper describes InSAR operational steps and processing chain for DEM generation from Single Look Complex (SLC) SAR data and compare a satellite SAR estimate of surface elevation with a digital elevation model (DEM) from Topography map. The operational steps are performed in three major stages: Data Search, Data Processing, and product Validation. The Data processing stage is further divided into five steps of Data Pre-Processing, Co-registration, Interferogram generation, Phase unwrapping, and Geocoding. The Data processing steps have been tested with ERS 1/2 data using Delft Object-oriented Interferometric (DORIS) InSAR processing software. Results of the outcome of the application of the described processing steps to real data set are presented.

Nguyen, Duy

2012-07-01

146

Open-Source MFIX-DEM Software for Gas-Solids Flows: Part II - Validation Studies  

SciTech Connect

With rapid advancements in computer hardware and numerical algorithms, computational fluid dynamics (CFD) has been increasingly employed as a useful tool for investigating the complex hydrodynamics inherent in multiphase flows. An important step during the development of a CFD model and prior to its application is conducting careful and comprehensive verification and validation studies. Accordingly, efforts to verify and validate the open-source MFIX-DEM software, which can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles, have been made at the National Energy Technology Laboratory (NETL). In part I of this paper, extensive verification studies were presented and in this part, detailed validation studies of MFIX-DEM are presented. A series of test cases covering a range of gas–solids flow applications were conducted. In particular the numerical results for the random packing of a binary particle mixture, the repose angle of a sandpile formed during a side charge process, velocity, granular temperature, and voidage profiles from a bounded granular shear flow, lateral voidage and velocity profiles from a monodisperse bubbling fluidized bed, lateral velocity profiles from a spouted bed, and the dynamics of segregation of a binary mixture in a bubbling bed were compared with available experimental data, and in some instances with empirical correlations. In addition, sensitivity studies were conducted for various parameters to quantify the error in the numerical simulation.

Li, Tingwen

2012-04-01

147

Open-source MFIX-DEM software for gas-solids flows: Part II Validation studies  

SciTech Connect

With rapid advancements in computer hardware and numerical algorithms, computational fluid dynamics (CFD) has been increasingly employed as a useful tool for investigating the complex hydrodynamics inherent in multiphase flows. An important step during the development of a CFD model and prior to its application is conducting careful and comprehensive verification and validation studies. Accordingly, efforts to verify and validate the open-source MFIX-DEM software, which can be used for simulating the gas solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles, have been made at the National Energy Technology Laboratory (NETL). In part I of this paper, extensive verification studies were presented and in this part, detailed validation studies of MFIX-DEM are presented. A series of test cases covering a range of gas solids flow applications were conducted. In particular the numerical results for the random packing of a binary particle mixture, the repose angle of a sandpile formed during a side charge process, velocity, granular temperature, and voidage profiles from a bounded granular shear flow, lateral voidage and velocity profiles from a monodisperse bubbling fluidized bed, lateral velocity profiles from a spouted bed, and the dynamics of segregation of a binary mixture in a bubbling bed were compared with available experimental data, and in some instances with empirical correlations. In addition, sensitivity studies were conducted for various parameters to quantify the error in the numerical simulation.

Li, Tingwen [National Energy Technology Laboratory (NETL); Garg, Rahul [National Energy Technology Laboratory (NETL); Galvin, Janine [National Energy Technology Laboratory (NETL); Pannala, Sreekanth [ORNL

2012-01-01

148

Effect of cohesion on granular-fluid flows in spouted beds: PIV measurement and DEM simulations  

NASA Astrophysics Data System (ADS)

In contrast to wet granular flows, the effect of cohesion on complex granular-fluid flows is intriguing but much challenging. The liquid bridges, forming between binary particles with the addition of a small amount of liquids, might significantly change the granular-fluid system due to both cohesion and lubrication effects. In this paper, a spouted bed, among various fluidization technologies, is particularly selected as a prototypical system for studying granular-fluid flows, since it can provide a quasi-steady flow pattern of granular particles, i.e., a core of upward granular-fluid flow called the "spout" and a surrounding region of downward quasi-static granular flow called the "annulus". Firstly, using self-developed particle image velocimetery (PIV) technique, the effects of cohesion on the spout-annulus interface (namely the spout width) and on the particle velocity profiles in distinct zones are examined. Further, the discrete element method (DEM), by incorporating liquid bridge adhesion into soft-sphere model, is established and used to predict the microdynamic behavior of particles in spouted beds. Finally, based on both experiments and DEM validation, the effects on the granular patterns in these two zones are comparatively discussed.

Zhu, Runru; LI, Shuiqing; Yao, Qiang

2013-06-01

149

1963 Vajont rock slide: a comparison between 3D DEM and 3D FEM  

NASA Astrophysics Data System (ADS)

Data on the exact location of the failure surface of the landslide have been used as the starting point for the modelling of the landslide. 3 dimensional numerical analyses were run employing both the discrete element method (DEM) and a Finite Element Method (FEM) code. In this work the focus is on the prediction of the movement of the landlside during its initial phase of detachment from Mount Toc. The results obtained by the two methods are compared and conjectures on the observed discrepancies of the predictions between the two methods are formulated. In the DEM simulations the internal interaction of the sliding blocks and the expansion of the debris is obtained as a result of the kinematic interaction among the rock blocks resulting from the jointing of the rock mass involved in the slide. In the FEM analyses, the c-phi reduction technique was employed along the predefine failure surface until the onset of the landslide occurred. In particular, two major blocks of the landslide were identified and the stress, strain and displacement fields at the interface between the two blocks were analysed in detail.

Crosta, Giovanni; Utili, Stefano; Castellanza, Riccardo; Agliardi, Federico; Bistacchi, Andrea; Weng Boon, Chia

2013-04-01

150

Region-growing segmentation to automatically delimit synthetic drumlins in 'real' DEMs  

NASA Astrophysics Data System (ADS)

Mapping or 'delimiting' landforms is one of geomorphology's primary tools. Computer-based techniques, such as terrain segmentation, may potentially provide terrain units that are close to the size and shape of landforms. Whether terrain units represent landforms heavily depends on the segmentation algorithm, its settings and the type of underlying land-surface parameters (LSPs). We assess a widely used region-growing technique, i.e. the multiresolution segmentation (MRS) algorithm as implemented in object-based image analysis software, for delimiting drumlins. Supervised testing was based on five synthetic DEMs that included the same set of perfectly known drumlins at different locations. This, for the first time, removes subjectivity from the reference data. Five LSPs were tested, and four variants were computed for each using two pre- and post-processing options. The automated method (1) employs MRS to partition the input LSP into 200 ever coarser terrain unit patterns, (2) identifies the spatially best matching terrain unit for each reference drumlin, and (3) computes four accuracy metrics for quantifying the aerial match between delimited and reference drumlins. MRS performed best on LSPs that are regional, derived from a decluttered DEM and then normalized. Median scale parameters (SPs) for segments best delineating drumlins were relatively stable for the same LSP, but varied significantly between LSPs. Larger drumlins were generally delimited at higher SPs. MRS indicated high robustness against variations in the location and distribution of drumlins.

Eisank, Clemens; Smith, Mike; Hillier, John

2013-04-01

151

DEM simulations of the evolution of fault zones in brittle-ductile layered rocks  

NASA Astrophysics Data System (ADS)

The development of normal faults in brittle ductile layered rocks is modeled in this work using the Discrete Element Model (DEM) approach. The simulations were realized using the open source DEM package ESyS-Particle (https://launchpad.net/esys-particle/). The models consist of one cemented layer inside a cohesionless granular material above a basement fault in a gravity field. The cohesion of the cemented layer and the angle of the basement fault were varied. Different random packings of the material were used to estimate the effect of the material heterogeneity. Results show, that two structural domains exist, a graben domain and a precursor domain. In both of these domains, the variation in cohesion of the hard layer produces large differences in the structural evolution. As expected, the largest changes in fault gouge evolution occur when the increase in cohesion of the hard layer make the minimum principle stress become tensile. The main parameter that determines the amount of tectonic abrasion in the fault zones is the cohesion of the brittle layer. This leads to a gradual thinning of the layer with low cohesion and development of blocks and fragments in case of a relatively high cohesion. Thus, continuity of the sheared layer is higher in the rocks with low cohesion. The structural domain also affects the continuity of the brittle layer: in the precursor domain the brittle layer is more continuous than in the graben domain.

Raith, Alexander; Urai, Janos L.; Abe, Steffen

2013-04-01

152

Assessment of an ASTER-generated DEM for 2D hydrodynamic flood modeling  

NASA Astrophysics Data System (ADS)

Flood modeling often provides inputs to flood hazard management. In the present work we studied the flooding characteristics in the data scarce region of the Lake Tana basin at the source of the Blue Nile River. The study required to integrate remote sensing, GIS with a two-dimensional (2D) module of the SOBEK flood model. The resolution of the topographic data in many areas, such as the Lake Tana region, is commonly too poor to support detailed 2D hydrodynamic modeling. To overcome such limitations, we used a Digital Elevation Model (DEM) which was generated from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image. A GIS procedure is developed to reconstruct the river terrain and channel bathymetry. The results revealed that a representation of the river terrain largely affects the simulated flood characteristics. Simulations indicate that effects of Lake Tana water levels propagate up to 13 km along the Ribb River. We conclude that a 15 m resolution ASTER DEM can serve as an input to detailed 2D hydrodynamic modeling in data scarce regions. However, for this purpose it is necessary to accurately reconstruct the river terrain geometry and flood plain topography based on ground observations by means of a river terrain model.

Tarekegn, Tesfaye Haimanot; Haile, Alemseged Tamiru; Rientjes, Tom; Reggiani, P.; Alkema, Dinand

153

Volcanic Landform Classification of Iwate Volcano from DEM-Derived Thematic Maps  

NASA Astrophysics Data System (ADS)

Over the last three decades, digital elevation models (DEMs) have been developed as surface data instead of contour lines to allow numerical analysis or modeling of terrain by computer. DEMs have allowed the development of algorithms to rapidly derive slope, relief, convexity, concavity and aspect of any points of surface, and also have allowed the definition of a number of new morphometric measures i.e. openness (Yokoyama et al., 2002). Openness is an angular measure of the relation between surface relief and horizontal distance. Openness has two viewer perspectives. Positive values, expressing openness above the surface, are high for convex forms, whereas negative values describe this attribute below the surface and are high for concave forms. The emphasis of terrain convexity and concavity in openness maps facilitates the interpretation of landforms on the Earth_fs surface. Prima et al. (2003) proposed automated landform classification using openness and slope with genetic factors. This method had been proved to produce good classification for constructional (alluvial plains, alluvial fans and volcanoes) and erosional (hills and mountains) landforms. The capability of this method to classify landforms from DEMs with genetic factors is important because it allows landform evolution to be numerically analyzed. In this study, we adopted this method to classify volcanic landforms of Iwate Volcano from Honshu, Japan, where volcanic landforms were categorized referring to geological map of Iwate Volcano (Doi, 2000). This process took three steps. First, the characteristic of each category was evaluated against the mean and standard deviation of slope, and both positive and negative openness, in two dimensional feature spaces. Second, the characteristic of each category were observed and the combinations of mean and standard deviation of slope and openness showing high separabilities were selected. We found that the standard deviation of slope, positive and negative openness yielded high separabilities of each category and indicated consistency between the trend of categories_f distribution and their geological successions. Third, Mahalanobis distance was used as classification rule to automatically classify the volcanic landforms of Iwate Volcano with those categories. The result shows fine interpretation of volcanic landforms of Iwate Volcano according to their geological successions. The northeastern sector of Iwate Volcano that has relatively young strata was clearly identified against other sectors of the volcano. Although some misclassification occurred in places where the ages of landform formation are relatively close, we considered that the present result is provisionally acceptable because the classified landforms in major accurately replicated many components of volcanic landforms of Iwate Volcano.

Prima, A. O.; Yoshida, T.

2004-12-01

154

Comparison of the SRTM DEM for the Olympic Mountains to Existing DEMs of Varying Resolutions: Results and General Implications for Application of SRTM data to Models of Hillslope and Fluvial Processes in Mountainous Regions  

Microsoft Academic Search

Predicting the spatial patterns and rates of many geomorphic processes such as hillslope erosion and down-valley sediment transport requires an accurate representation of the land surface at a scale appropriate to the particular process model. Until now, Digital Elevation Models (DEMs) throughout much of the world were of very coarse resolution (1 km) and inconsistent quality (a number of elevation

D. R. Montgomery; R. Aalto

2001-01-01

155

Modeling Particle Rolling Behavior by the Modified Eccentric Circle Model of DEM  

NASA Astrophysics Data System (ADS)

This study proposes a modified eccentric circle model to simulate the rolling resistance of circle particles through the distinct element method (DEM) simulation. The proposed model contains two major concepts: eccentric circle and local rotational damping. The mass center of a circular particle is first adjusted slightly for eccentricity to provide rotational stiffness. Local rotational damping is adopted to dissipate energy in the rotational direction. These associated material parameters can be obtained easily from the rolling behavior of one rod. This study verifies the proposed model with the repose angle tests of chalk rod assemblies, and the simulated results were satisfactory. Simulations using other existing models were also conducted for comparison, showing that the proposed model achieved better results. A landslide model test was further simulated, and this simulation agreed with both the failure pattern and the sliding process. In conclusion, particle rolling simulation using the proposed model appears to approach the actual particle trajectory, making it useful for various applications.

Chang, Yi-Long; Chen, Tsung-Hsien; Weng, Meng-Chia

2012-09-01

156

DEM analysis of effects of particle properties and mixing conditions on particle attachment processes  

NASA Astrophysics Data System (ADS)

The attachment of autoadhesive fine particles onto a large carrier particle in a vibrating container is investigated using a discrete element method (DEM) to determine the influence of the particle properties and vibration conditions. The contact number (number of fine particles contacting the carrier), coverage ratio (ratio of the contact number to that for complete monolayer coverage) and contact ratio (ratio of the contact number to the number of fine particles) are introduced to evaluate the attachment performance. The contact number increases with increasing work of adhesion, decreasing container size and increasing number of fine particles. The contact ratio decreases as the number of fine particles is increased. The coverage ratio increases as the carrier size is decreased.

Yang, Jiecheng; Wu, Chuan-Yu; Adams, Michael

2013-06-01

157

Fluid coupling in DEM simulation using Darcy's law: Formulation, and verification  

NASA Astrophysics Data System (ADS)

The fluid coupled-DEM has recently become a popular topic in the field of granular material simulation. In most simulations, the averaged Navier-Stokes equations are implemented to consider the fluid flow through particles. In this paper, a simple algorithm based on Darcy's law was discussed to avoid expensive computational effort of solving of the Navier-Stokes equations. The results of this approach were compared quantitatively with the well-known analytical solution of 1D seepage through a soil column as a fully coupled problem in geotechnical engineering. The comparison between the developed pore pressure and induced displacement with analytical values revealed that this algorithm is capable of simulating fluid-particle interaction accurately within the laminar regime.

Goodarzi, M.; Kwok, C. Y.; Tham, L. G.; Chen, F.

2013-06-01

158

3DEM Loupe: analysis of macromolecular dynamics using structures from electron microscopy  

PubMed Central

Electron microscopy (EM) provides access to structural information of macromolecular complexes in the 3–20 Å resolution range. Normal mode analysis has been extensively used with atomic resolution structures and successfully applied to EM structures. The major application of normal modes is the identification of possible conformational changes in proteins. The analysis can throw light on the mechanism following ligand binding, protein–protein interactions, channel opening and other functional macromolecular movements. In this article, we present a new web server, 3DEM Loupe, which allows normal mode analysis of any uploaded EM volume using a user-friendly interface and an intuitive workflow. Results can be fully explored in 3D through animations and movies generated by the server. The application is freely available at http://3demloupe.cnb.csic.es.

Nogales-Cadenas, R.; Jonic, S.; Tama, F.; Arteni, A. A.; Tabas-Madrid, D.; Vazquez, M.; Pascual-Montano, A.; Sorzano, C. O. S.

2013-01-01

159

Mechanical behavior modeling of sand-rubber chips mixtures using discrete element method (DEM)  

NASA Astrophysics Data System (ADS)

Rubber shreds in mixture with sandy soils are widely used in geotechnical purposes due to their specific controlled compressibility characteristics and light weight. Various studies have been carried out for sand or rubber chips content in order to restrain the compressibility of the mass in different structures such as backfills, road embankments, etc. Considering different rubber contents, sand-rubber mixtures can be made which lead mechanical properties of the blend to go through changes. The aim of this paper is to study the effect of adding different rubber portions on the global engineering properties of the mixtures. This study is performed by using Discrete Element Method (DEM). The simulations showed that adding rubber up to a particular fraction can improve maximum bearing stress characteristics comparing to sand alone masses. Taking the difference between sand and rubber stiffness into account, the result interpretation can be developed to other soft and rigid particle mixtures such as powders or polymers.

Eidgahee, Danial Rezazadeh; Hosseininia, Ehsan Seyedi

2013-06-01

160

DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam  

NASA Astrophysics Data System (ADS)

The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

Bui, H. T.; Yamada, Y.; Matsuoka, T.

2005-12-01

161

Upscaling water cycle parameters using geomorphometric terrain parameters and topographic indices derived from interferometric DEM  

NASA Astrophysics Data System (ADS)

For assessing a regional water balance in boreal landscapes the extend to which evapo-transpiration is subject to spatial variations needs to be known. Water cycle parameters such as transpiration rates of vegetation are depending on both the vegetation type and hydro-pedologic stand conditions since poor soil drainage respective seasonal soil drought affect water consumption by vegetation. The spatial distribution of the pristine boreal vegetation types can be obtained by SAR or optical remote sensing sensors on a regional scale. Many works have been dealing with this subject in the past and it is widely known how remote sensing can contribute to vegetation mapping. To assess hydro-pedologic stand conditions on a regional scale an alternative method is required. Our approach to resolve this problem is based on the fact that soil water status is essentially a function of topographic properties. For that reason morphometric terrain parameters derived from a Digital Elevation Model (DEM) has been used to indicate regions with homogeneous hydro-pedologic stand conditions, so called "hydropedotopes". To delineate the required hydropedotopes two indicators pertaining to soilwater status and pedo-hydrology were derived from InSAR DEM: (1) The wetness-index and (2) the vertical distance to streams and bottom lines. In a further step the resulting map of hydropedotopes is intersected with a remote sensing derived map of the actual spatial distribution of the boreal vegetation types. This step results in a map which marks out landscape units of homogeneous properties in terms of vegetation type and hydro-pedologic conditions which is the basis for upscaling canopy transpiration measurements. From our approach which uses in addition to conventional remote sensing data the results of an automated digital terrain analysis we expect a substantially enhanced knowledge of the spatial variability of water flux rates conditional on canopy transpiration. The process of our approach at a glance is illustrated.

Etzrodt, N.; Zimmermann, R.; Conrad, O.

2002-01-01

162

A New Processing Chain based on Neural Networks for the Construction of X-SAR DEM: Tuning of new algorithms and Validation of the Output  

NASA Astrophysics Data System (ADS)

The main goal of the activity we plan to perform concerns the description of a new approach for the production of Digital Elevation Models (DEM) based on neural network and the relative activity of their validation. The DEM have been extracted from the X-SAR images caught by the COSMO-SKYMED Italian space mission fully devoted to remote sensing. In particular we have developed in parallel two processing chain to obtain DEMs. The first one applies the conventional algorithms currently used and implemented in the DORIS open source software developed by Delft University. The second one implements our algorithms which apply neural networks to determine the features of the single pixels taking into account also the behavior of neighboring pixels. Thus a comparison of the achieved DEM with the two different processing chain is performed. For the validation of DEMs obtained with our algorithms we plan to construct a third DEM overlapped to the other two, using the GPS-RTK technique. This technique is capable to return DEMs with a precision of few tens of centimeters; i.e. enough precise to validate the X-SAR DEM. For the validation activity we have selected an area close to Matera Space Geodesy Center which cover both flat an hilly surfaces.

Brizio, Franco; Gentili, Mario; Fabrizi, Marco; Vespe, Francesco; Benedetto, Catia

2013-04-01

163

Map of deep seated gravitational slope deformations susceptibility in central Italy derived from SRTM DEM and spectral mixing analysis of the Landsat ETM+ data  

Microsoft Academic Search

Considerable enhancement for morphometric interpretation can be obtained by means of the integration of spectral data with Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). The effectiveness of topography classification with SRTM DEM is enhanced by the use of optical remote sensing data such as Landsat ETM+ that has undergone Spectral Mixing Analysis (SMA). The SMA uses a linear

A. Taramelli; L. Melelli

2009-01-01

164

DEM-LES of coal combustion in a bubbling fluidized bed. Part I: gas-particle turbulent flow structure  

Microsoft Academic Search

The gas and particle motions in a bubbling fluidized bed both with and without chemical reactions are numerically simulated. The solid phase is modelled as Discrete Element Method (DEM) and the gas phase is modelled as 2-D Navier–Stokes equations for 2-phase flow with fluid turbulence calculated by large Eddy simulation (LES), in which the effect of particles on subgrid scale

Haosheng Zhou; Gilles Flamant; Daniel Gauthier

2004-01-01

165

Analysis of stirred mill performance using DEM simulation: Part 1– Media motion, energy consumption and collisional environment  

Microsoft Academic Search

Stirred mills are becoming increasingly used for fine and ultra-fine grinding. This technology is still poorly understood when used in the mineral processing context. This makes process optimisation of such devices problematic. 3D DEM simulations of the flow of grinding media in pilot scale tower mills and pin mills are carried out in order to investigate the relative performance of

Matt Sinnott; Paul W. Cleary; Rob Morrison

2006-01-01

166

Bedeutung der EKG-Triggerung mit dem Multi-Slice-CT zum Ausschluss einer Koronararterienverkalkung bei Personen ohne bekannte KHK  

Microsoft Academic Search

Hintergrund: Zur Vermeidung überflüssiger Herzkatheter kommt dem Ausschluss einer Koronararterienverkalkung ein hoher Stellenwert zu. Andererseits ist der Nachweis einer Koronararterienverkalkung beweisend für das Vorliegen einer Koronarsklerose und erfordert nach den NCEP-Richtlinien eine Absenkung des LDL-Cholesterins unter 100 mg\\/dl. Als \\

Sigmund Silber

2001-01-01

167

Experience using of DEM's as a basis for landscapes classification at selection of geochemical methods of prospecting.  

NASA Astrophysics Data System (ADS)

The results high-precision satellite sensing of the Earth and the rapid development of GIS-technology can are open new areas of application of the DEM's. One such example is the landscape zoning is an integral component during geological and geochemical exploration at any scale. The main goal of zoning is rational choosing of geological and geochemical methods of prospecting, which are effective in different landscape environments. Degree of territory openness plays an important role during geochemical explorations, especially lithogeochemical ones, both after the primary and secondary halos and leakage streams (Sokolov S.V. and Yurchenko Yu.Yu., 2010). Practice proves that the most effective method of territory zoning after this indicator is morphometric analysis on the basis of DEM. Particularly, the use of DEM for landscape-ecological zoning was tested by B.A. Nowakowski et al (2003). The basic elements of DEM are maps of angles inclination and slopes exposure, as well as maps of basal surface of n-order streams and others. Introduction of available geological data (structural-tectonic scheme, maps of the Quaternary deposits and others) in the DEM structure allows us to make zoning of territories after the conditions of geochemical explorations by the most correct way both on qualitative and quantitative levels. Using of the morphometric analysis basic elements in total with modern GIS-technologies and integrated analysis of geological and geochemical information allowed us to make landscape zoning after the conditions of geochemical explorations of the individual sites and areas in general (the Karelian-Kola Region, Taimyr Peninsula and Amur Region). Based on the obtained results, typical landscape surroundings after their degree of openness were defined. The primary measure of their openness is the angle of the slope. The proposed technology based on digital elevation models allows toconduct landscape zoning of areas and separate sites both on the regional stages of prospecting and at detailed exploration.

Yurchenko, Yu. Yu.; Sokolov, S. V.

2012-04-01

168

Glaziäre Entwässerung und Sanderbildung am Kötlujökull, Südisland  

Microsoft Academic Search

Zusammenfassung: In einer über mehrere Sommer fortgesetzten Arbeit am ca. 8 km langen südöstlichen Eisrand des Kötlujökull in Südis­ land wurde arn Beispiel der rezenten Entwicklung eines Gletscherrandgebietes der Zusammenhang zwischen Entwässerungsmodus des Glet­ schers und seinen Vorlandbildungen untersucht. Hierbei ergab sich das Folgende: In einer I. vor 1945 begonnenen und zwischen 1966 und 1975 beendeten Phase wurde durch insgesamt

Dieter Heim

169

The accuracy of photo-based structure-from-motion DEMs  

NASA Astrophysics Data System (ADS)

Data for detailed digital elevation models (DEMs) are usually collected by expensive laser-based techniques, or by photogrammetric methods that require expertise and specialist software. However, recent advances in computer vision research now permit 3D models to be automatically derived from unordered collections of photographs, offering the potential for significantly cheaper and quicker DEM production. Here, we assess the accuracy of this approach for geomorphological applications using examples from a coastal cliff and a volcanic edifice. The reconstruction process is based on a combination of structure-from-motion and multi-view stereo algorithms (SfM-MVS). Using multiple photographs of a scene taken from different positions with a consumer-grade camera, dense point clouds (millions of points) can be derived. Processing is carried out by automated 'reconstruction pipeline' software downloadable from the internet, e.g. http://blog.neonascent.net/archives/bundler-photogrammetry-package/. Unlike traditional photogrammetric approaches, the initial reconstruction process does not require the identification of any control points or initial camera calibration and is carried out with little or no operator intervention. However, such reconstructions are initally un-scaled and un-oriented so additional software (http://www.lancs.ac.uk/staff/jamesm/software/sfm_georef.htm) has been developed to permit georeferencing. Although this step requires the presence of some control points or features within the scene, it does not have the relatively strict image acquisition and control requirements of traditional photogrammetry. For accuracy, and to allow error analysis, georeferencing observations are made within the image set, rather than requiring feature matching within the point cloud. In our coastal example, 133 photos taken with a Canon EOS 450D and 28 mm prime lens, from viewing distances of ~20 m, were used to reconstruct a ~60 m long section of eroding cliff. The resulting surface model was compared with data collected by a Riegl LMS-Z210ii terrestrial laser scanner. Differences between the surfaces were dominated by the varying effects of occlusions on the techniques, and systematic distortion of the SfM-MVS model along the length of the cliff could not be resolved over the ±15 mm precision of the TLS data. For a larger-scale example, a ~1.6 km wide region over the summit of Piton de la Fournaise volcano was reconstructed using 133 photos taken with a Canon EOS D60 and 20 mm prime lens, from a microlight aircraft (with a representative viewing distance of 1.0 km). In this case, the resulting DEM showed an RMS error of 1.0 m when compared with the results from traditional photogrammetry and some areas of systematic error were evident. Such errors were minimised by reprocessing the SfM-MVS results with a more sophisticated camera model than is integrated into the reconstruction pipeline. In combination, the results indicate that, with a good, convergent image set, SfM-MVS can be anticipated to deliver relative precisions of 1:1000 or better, for geomorphological applications. However, under certain conditions, the restricted camera model used can result in detectable error. We highlight the requirement for new network design tools that will help optimise image collection, facilitate error visualisation and allow a user to determine whether their image network is fit for purpose.

James, M. R.; Robson, S.

2012-04-01

170

DEM simulation of particle mixing for optimizing the overcoating drum in HTR fuel fabrication  

NASA Astrophysics Data System (ADS)

The rotating drum was used for overcoating coated fuel particles in HTR fuel fabrication process. All the coated particles should be adhered to equal amount of graphite powder, which means that the particle should be mixed quickly in both radial and axial directions. This paper investigated the particle flow dynamics and mixing behavior in different regimes using the discrete element method (DEM). By varying the rotation speed, different flow regimes such as slumping, rolling, cascading, cataracting, centrifuging were produced. The mixing entropy based on radial and axial grid was introduced to describe the radial and axial mixing behaviors. From simulation results, it was found that the radial mixing can be achieved in the cascading regime more quickly than the slumping, rolling and centrifuging regimes, but the traditional rotating drum without internal components can not achieve the requirements of axial mixing and should be improved. Three different structures of internal components are proposed and simulated. The new V-shaped deflectors were found to achieve a quick axial mixing behavior and uniform axial distribution in the rotating drum based on simulation results. At last, the superiority was validated by experimental results, and the new V-shaped deflectors were used in the industrial production of the overcoating coated fuel particles in HTR fuel fabrication process.

Liu, Malin; Lu, Zhengming; Liu, Bing; Shao, Youlin

2013-06-01

171

Macromolecular Structure Modeling from 3DEM Using VolRover 2.01  

PubMed Central

We report several tools for 3DEM structure identification and model-based refinement developed by our research group and implemented in our in-house software package, VolRover. For viral density maps with icosahedral symmetry, we segment the capsid, polymeric and monomeric subunits using segmentation techniques based on symmetry detection and fast marching. For large biomolecules without symmetry information, we use a multi-seeded fast-marching method to segment meaningful substructures. In either case, we subject the resulting segmented subunit to secondary structure detection when the EM resolution is sufficiently high, and rigid-body fitting when the corresponding crystal structure is available. Secondary structure elements are identified by our volume- and boundary-based skeletonization methods as well as a new method, currently in development, based on solving the grassfire flow equation. For rigid-body fitting, we use a translational fast Fourier based scheme. We apply our segmentation, secondary structure elements identification, and rigid-body fitting techniques to the PSB 2011 cryo-EM modeling challenge data, and compare our results to those submitted from other research groups. The comparisons show that our software is capable of segmenting relatively accurate subunits from a viral or protein assembly, and that the high segmentation quality leads in turn to high-quality results of secondary structure elements identification and rigid-body fitting.

Zhang, Qin; Bettadapura, Radhakrishna

2012-01-01

172

Discrete element method (DEM) simulations of stratified sampling during solid dosage form manufacturing.  

PubMed

Discrete element model (DEM) simulations of the discharge of powders from hoppers under gravity were analyzed to provide estimates of dosage form content uniformity during the manufacture of solid dosage forms (tablets and capsules). For a system that exhibits moderate segregation the effects of sample size, number, and location within the batch were determined. The various sampling approaches were compared to current best-practices for sampling described in the Product Quality Research Institute (PQRI) Blend Uniformity Working Group (BUWG) guidelines. Sampling uniformly across the discharge process gave the most accurate results with respect to identifying segregation trends. Sigmoidal sampling (as recommended in the PQRI BUWG guidelines) tended to overestimate potential segregation issues, whereas truncated sampling (common in industrial practice) tended to underestimate them. The size of the sample had a major effect on the absolute potency RSD. The number of sampling locations (10 vs. 20) had very little effect on the trends in the data, and the number of samples analyzed at each location (1 vs. 3 vs. 7) had only a small effect for the sampling conditions examined. The results of this work provide greater understanding of the effect of different sampling approaches on the measured content uniformity of real dosage forms, and can help to guide the choice of appropriate sampling protocols. PMID:21635943

Hancock, Bruno C; Ketterhagen, William R

2011-05-23

173

New insights into high resolution DEM structural analysis with Coltop3D software  

NASA Astrophysics Data System (ADS)

Modern measurement devices such a terrestrial laser scanning (TLS) systems allow for collecting tremendous amount of (x,y,z) points (up to 20 millions) within a few minutes. However, data analysis still may be impaired because of software limitations, which are usually not designed to handle such huge data sets. To overcome this shortcoming, a software - Coltop3D - was written from scratch. Coltop3D aims at providing the geosciences community a powerful tool to visually handle seamlessly large point clouds and large regular grids DEM, at allowing for straightforward visual analysis of the data with different colour scheme, and at providing specific geologist and/or geoscientist treatment methods such as structural analysis. The main features of Coltop3D are as follow: 1) Ability to handle huge data sets (up to 150 millions points); 2) Coloring the surface with a color scheme linking computer graphics HSV wheel and Schmidt-Lambert stereonet projection; 3) Ability to select a subset of a point cloud with complex geometric shapes; 4) Ability to select a subset of a point cloud with dip and dip direction values; 5) Creating density stereonets with selected subset; 6) Easily import from or export point cloud data to third party software. Besides the technical and basic capabilities of Coltop3D, specific case studies such as structural analysis and rock fall analysis will be presented.

Metzger, R.; Jaboyedoff, M.; Oppikofer, T.

2009-04-01

174

Strength characterization of rock masses, using a coupled DEM-DFN model  

NASA Astrophysics Data System (ADS)

A discrete element model (DEM) is used to study the mechanical behaviour of a pre-fractured brittle medium subjected to triaxial loadings where progressive failure can occur. The initial discrete fracture network (DFN) is based on a fractal distribution and it is used to characterize the influence of clustering and size distribution of pre-existing fractures, on the strength of fractured rock masses. The proposed approach captures the progressive failure process occurring in the rock matrix as shearing displacement takes place along pre-existing discontinuities. The results show that the mechanical behaviour of fractured rock masses is mainly dependent on the fracture intensity. However, for a given fracture intensity, the strength can exhibit a 50 per cent variability depending on the size distribution of the pre-existing fractures. This difference can be attributed to the different mechanisms that involve sliding and crushing of blocks in the case of large interconnected fractures or progressive failure of the rock matrix through coalescence of cracks in the case of small unconnected fractures. Clustering of fractures was found to influence the spatial variability of the mechanical properties and therefore to have a scale effect on strength. The results outline the relevance of three parameters, the power-law exponent of the fracture size distribution, the clustering fractal dimension which fixes the fracture-to-fracture correlation number and the fracture intensity, to characterize the mechanical behaviour of rock masses.

Harthong, Barthélémy; Scholtès, Luc; Donzé, Frédéric-Victor

2012-09-01

175

Cooperative dynamics of a group of intruders subsiding in granular media: A DEM study  

NASA Astrophysics Data System (ADS)

We numerically investigated the subsidence of a group of solid intruders in a randomly generated granular bed using discrete element method (DEM) in 2D and explored the cooperative behaviour of these intruders. Five intruders with a specified separation distance were placed on the surface of the granular bed and released to subside with zero impact velocity. Dynamics of the intruders was analysed. In addition, the effects of friction, boundary constraints, and the diameter and density ratio of the intruders to particles in the granular bed on the cooperative dynamics were also examined. It was found that friction and boundary constraints significantly affected the subsiding kinematics of the intruders. Most interestingly, it was shown that the intruders subside in a cooperative manner as they initially split from each other, and then move toward each other, resembling the flying pattern of a flock of birds in the air. This cooperative behaviour is in broad agreement with the experimental observations of Pacheco-Vazquez and Ruiz-Suarez (2010).

Goey, Cher Hui; Wu, Chuan-Yu

2013-06-01

176

NETVOLC: An algorithm for automatic delimitation of volcano edifice boundaries using DEMs  

NASA Astrophysics Data System (ADS)

Accurately delimiting boundaries is required for characterizing landforms through measurement of their geomorphometric parameters. Volcanism produces a wide range of landforms, from symmetric cones to very irregular massifs, that can gradually merge with the surroundings and contain other elements, thus complicating landform delimitation. Most morphometric studies of volcanoes delimit landforms manually, with the inconvenience of being time-consuming and subjective. Here we propose an algorithm, NETVOLC, for automatic volcano landform delimitation based on the premise that edifices are bounded by concave breaks in slope. NETVOLC applies minimum cost flow (MCF) networks for computing the best possible edifice outline using a DEM and its first- and second-order derivatives. The main cost function considers only profile convexity and aspect; three alternative functions (useful in complex cases) also consider slope, elevation and/or radial distance. NETVOLC performance is tested by processing the Mauna Kea pyroclastic cone field. Results using the main cost function compare favorably to manually delineated outlines in 2/3rds of cases, whereas for the remaining 1/3rd of cases an alternative cost function is needed, introducing some degree of subjectivity. Our algorithm provides a flexible, objective and time-saving tool for automatically delineating volcanic edifices. Furthermore, it could be used for delineating other landforms with concave breaks in slope boundaries. Finally, straightforward modifications can be implemented to extend the algorithm capabilities for delimiting landforms bounded by convex breaks in slope, such as summit craters and calderas.

Euillades, Leonardo D.; Grosse, Pablo; Euillades, Pablo A.

2013-07-01

177

Asperity Degradation and Damage in the Direct Shear Test: A Hybrid FEM/DEM Approach  

NASA Astrophysics Data System (ADS)

This paper investigates the processes of joint surface damage and near-surface intact rock tensile failure using a hybrid FEM/DEM code. Selected Barton and Choubey JRC profiles were simulated in direct shear tests and the surface damage mechanisms investigated in terms of joint surface wear or tensile fracturing of intact rock along the joint plane. Shear strength and displacement profiles for each joint profile are numerically simulated. Numerical results agree closely with published experimental observations. Furthermore, results show that dilation along the joint is controlled dominantly by the joint surface geometry and the applied normal stress. Significant dilation is expected to occur where there is a large asperity provided the applied normal stress is low. In this case, joint surface damage is limited to surface wear. In contrast, when the applied normal stress is high, dilation will be low and damage is composed of both surface wear and asperity breakage through near-joint-surface intact rock tensile failure. Local joint dilation angles vary in proportion to the magnitude of the dilation. Several joint profiles with different geometrical configurations were simulated within a slope and the possible modes of joint surface damage were investigated. It was found that due to low normal stresses acting on the joint surfaces within a slope the dominant mode of joint surface damage is by yielding and surface wear of asperities.

Karami, A.; Stead, D.

2008-04-01

178

The morphology and dynamics of a multi-lobed supernova remnant in the LMC (DEM 34a, N11L)  

NASA Astrophysics Data System (ADS)

Photon-counting imagery of the 16×24 pc supernova remnant, DEM 34a, has revealed a secondary lobe projecting from the bright ring of emission line filaments. Spatially resolved, long-slit echelle spectra of the H? and [N II] emission lines show that complex motions are occurring within this remnant. Multiple lobes expanding with velocities of up to 350 km s-1 are present. The total H? flux of DEM 34a is measured as 2.1×10-12erg s-1cm-2 (uncorrected for interstellar extinction) and the H?/[N II] 6584+6548 Å and H?/[S II] 6731+6716 Å brightness ratios as 3.2 and 1.1 respectively. These values are consistent with a 71 km s-1 velocity for the radiative shock which ionizes this supernova remnant.

Meaburn, John

1987-12-01

179

Direct micromechanics derivation and DEM confirmation of the elastic moduli of isotropic particulate materials: Part I No particle rotation  

NASA Astrophysics Data System (ADS)

We derive the macroscopic elastic moduli of a statistically isotropic particulate aggregate material via the homogenization methods of Voigt (1928) (kinematic hypothesis), Reuss (1929) (static hypothesis), and Hershey (1954) and Kröner (1958) (self-consistent hypothesis), originally developed to treat crystalline materials, from the directionally averaged elastic moduli of three regular cubic packings of uniform spheres. We determine analytical expressions for these macroscopic elastic moduli in terms of the (linearized) elastic inter-particle contact stiffnesses on the microscale under the three homogenization assumptions for the three cubic packings (simple, body-centered, and face-centered), assuming no particle rotation. To test these results and those in the literature, we perform numerical simulations using the discrete element method (DEM) to measure the overall elastic moduli of large samples of randomly packed uniform spheres with constant normal and tangential contact stiffnesses (linear spring model). The beauty of DEM is that simulations can be run with particle rotation either prohibited or unrestrained. In this first part of our two-part series of papers, we perform DEM simulations with particle rotation prohibited, and we compare these results with our theoretical results that assumed no particle rotation. We show that the self-consistent homogenization assumption applied to the locally body-centered cubic (BCC) packing most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new analytical self-consistent results lead to significantly better predictions of Poisson's ratio than all prior published theoretical results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to all prior theoretical analyses, which were based on difficult-to-verify hypotheses involving overall inter-particle contact distributions. We continue the analysis begun in this first part for the case of unrestrained particle rotation in Part II, Fleischmann et al. (2013).

Fleischmann, J. A.; Drugan, W. J.; Plesha, M. E.

2013-07-01

180

The morphology and dynamics of a multi-lobed supernova remnant in the LMC (DEM 34a, N11L)  

Microsoft Academic Search

Photon-counting imagery of the 16×24 pc supernova remnant, DEM 34a, has revealed a secondary lobe projecting from the bright ring of emission line filaments. Spatially resolved, long-slit echelle spectra of the Halpha and [N II] emission lines show that complex motions are occurring within this remnant. Multiple lobes expanding with velocities of up to 350 km s-1 are present. The

John Meaburn

1987-01-01

181

Development of New Accurate, High Resolution DEMs and Merged Topographic-Bathymetric Grids for Inundation Mapping in Seward Alaska  

NASA Astrophysics Data System (ADS)

The Geophysical Institute of the University of Alaska Fairbanks and the Alaska Division of Geological and Geophysical Surveys continue to participate in the National Tsunami Hazard Mitigation Program by evaluating and mapping potential inundation of selected coastal communities in Alaska. Seward, the next Alaskan community to be mapped, has excellent bathymetric data but very poor topographic data available. Since one of the most significant sources of errors in tsunami inundation mapping is inaccuracy of topographic and bathymetric data, the Alaska Tsunami Modeling Team cooperated with the local USGS glaciology office to perform photogrammetry in the Seward area to produce a new DEM. Using ten air photos and the APEX photogrammetry and analysis software, along with several precisely located GPS points, we developed a new georeferenced and highly accurate DEM with a 5-meter grid spacing. A variety of techniques were used to remove the effects of buildings and trees to yield a bald earth model. Finally, we resampled the new DEM to match the finest resolution model grid, and combined it with all other data, using the most recent and accurate data in each region. The new dataset has contours that deviate by more than 100 meters in some places from the contours in the previous dataset, showing significant improvement in accuracy for the purpose of tsunami modeling.

Marriott, D.; Suleimani, E.; Hansen, R.

2004-05-01

182

New morphometric properties for channel network classification using the graph theory and DEM  

NASA Astrophysics Data System (ADS)

The channel network controls the spatial pattern of hydrological processes within a catchment. Hence the identification of key hydrological features characterising the channel network can contribute to a rational classification of catchments. This presentation aims to investigate morphometric properties of the channel network derived from DEM using the graph theory, and estimate whether these properties can be used as similarity indices for the classification of channel networks. The graph theory was used in order to represent the contributing drainage area which has properties of a scale free network, and was subsequently characterised by highly connected nodes called hubs. The method involves ranking the hubs of a channel network according to the contributing drainage area and the distance to the outlet. The hubs' characteristics can be considered as morphometric descriptors of the channel network and are used to compare and classify channel network. Applications were conducted on 788 French catchments with the same area (between 100 and 105 km2) and on 18 catchments having an area between 43 and 116450 km2. First, we present some newly found invariance properties of headwater subcatchments and show that some invariant morphometric properties characterize only natural channel networks verifying Optimal Channel Networks (OCN) properties, but are not verified for non-OCN (Moussa et al., 2011, Water Resources Research, 47, W08518). A new empirical model based on self-affine properties was developed in order to calculate the number N and the total headwater area H as a function of the cutoff area S used to extract the channel network from DEM. Results show that H(S) / S0 (S0 being the catchment area) is independent from S and seems constant (0.29 +/- 0.03) for various shapes and sizes of channel networks, and consequently can be considered as invariant general descriptor of natural channel networks. On the contrary, this is not the case when the approach is applied on virtual non-OCN. Second, we define new morphometric descriptors on the basis of hub's properties in order to compare channel networks and to answer the following questions: are there any similar channel networks referred as 'twins'? and what channel network resembles most to an other given channel network? (Moussa et al., Water Resources Research, submitted). Two ways of classifications are proposed: the first one according a supervised procedure based on 8 types and a second one according a nested hierarchy considering the main hub as the key factor of the classification. Hence, we identify twelve twins networks among the 788 studied. These results show that the knowledge of six morphometric indices enable to calculate both functions N(S) and H(S) for all values of S < S0. These indices can be considered as geometric and topological properties of channel networks, and are useful for studying the effects of cutoffs on self-affine river networks or as similarity indices for channel network comparison.

Moussa, R.; Colin, F.; Rabotin, M.; A; Crabit

2012-04-01

183

A simulation of wide area surveillance (WAS) systems and algorithm for digital elevation model (DEM) extraction  

NASA Astrophysics Data System (ADS)

With the advances in focal plane, electronics and memory storage technologies, wide area and persistence surveillance capabilities have become a reality in airborne ISR. A WAS system offers many benefits in comparison with the traditional airborne image capturing systems that provide little data overlap, both in terms of space and time. Unlike a fix-mount surveillance camera, a persistence WAS system can be deployed anywhere as desired, although the platform typically has to be in motion, say circling above an area of interest. Therefore, WAS is a perfect choice for surveillance that can provide near real time capabilities such as change detection and target tracking. However, the performance of a WAS system is still limited by the available technologies: the optics that control the field-of-view, the electronics and mechanical subsystems that control the scanning, the focal plane data throughput, and the dynamics of the platform all play key roles in the success of the system. It is therefore beneficial to develop a simulated version that can capture the essence of the system, in order to help provide insights into the design of an optimized system. We describe an approach to the simulation of a generic WAS system that allows focal plane layouts, scanning patterns, flight paths and platform dynamics to be defined by a user. The system generates simulated image data of the area ground coverage from reference databases (e.g. aerial imagery, and elevation data), based on the sensor model. The simulated data provides a basis for further algorithm development, such as image stitching/mosaic, registration, and geolocation. We also discuss an algorithm to extract the terrain elevation from the simulated data, and to compare that with the original DEM data.

Cheng, Beato T.

2010-04-01

184

Afocal coupled etalons. DEM: a high-resolution doubleetalon modulator spectrometer.  

PubMed

The properties of a spectroscopic device consisting of two etalons coupled by an afocal system, and which behaves as a high-luminosity single-etalon single-aperture Fabry-Perot spectrometer, have been investigated. Although the high-luminosity behavior is one of the many states in which a coupled dual-etalon system can exist, mainly the high-luminosity condition has been studied in detail here. This condition is reached when the orders of the etalons comprising the device are related by n(01) = n(02)eta(-2), where the coupling constant is defined as eta = micro(1)micro(-1)(2)f(1)f(-1)(2) micro(i) and f(i) are the indices of refraction and coupling lens focal length associated with the ith etalon. In high-luminosity conditions, one of the etalons serves as a multiple annuli mask for the other thus making it possible to use many of these annuli to achieve the desired high throughput. The limitation on the number of orders usable is given by the (small) nonlinearity in the matching of these orders, because of the different etalon gaps. The results of the study show that luminosity gains near 100 (when compared with a single-etalon single-aperture Fabry-Perot spectrometer) are possible at high resolving powers. This occurs when the coupling constant eta is not too far from unity. It is also shown that this device, or double-etalon modulator (DEM), is a compensated spectrometer since the gain increases with increasing resolving power. Other practical limitations, such as the beam walk-off from the edges of finite size etalons, are discussed. PMID:20523460

Hernandez, G

1987-11-15

185

Das Image deutscher Öko-Zeichen - Unterscheiden Verbraucher zwischen Öko-Verbandszeichen, Öko- Herstellermarken, Öko-Handelsmarken und dem BioSiegel? - The Image of Organic Labels - Do Consumers Differentiate between Labels of Organic Producer Organisations, Organic Brands, Retailers' Own Organic Labels and the 'Bio Siegel'?  

Microsoft Academic Search

In Germany, consumers are confronted with more than 100 organic labels, which lead to uncertainty about the reliability of such labels. As a solution, one public organic label, the Bio-Siegel, was designed. This raises two questions from the marketing perspective: (1) Do any of the individual organic labels have a specific image, a unique selling proposition (USP)? (2) Does the

A. Wirthgen

186

Zur postembryonalen Entwicklung der Dreyfusia -Arten ( Hemipt., Adelgidae )  

Microsoft Academic Search

Zusammenfassung  Nach phänologischen Beobachtungen in den Jahren 1953 bis 1958 beginntD. prelli in der Freiburger Bucht bereits zwischen dem 13. 1. und 25. 1. mit Eierlegen,D. merkeri etliche Wochen später zwischen dem 9. 3. und 29. 3. (1958 ausnahmsweise am 14. 2.) undD. nüsslini noch ungefähr 10 Tage später zwischen dem 6. 3. und 5. 4. (Weißtannentiere).\\u000aNüsslini-Populationen an Nordmannstanne beginnen

O. Eichhorn

1961-01-01

187

Direct micromechanics derivation and DEM confirmation of the elastic moduli of isotropic particulate materials:. Part II Particle rotation  

NASA Astrophysics Data System (ADS)

In Part I, Fleischmann et al. (2013), we performed theoretical analyses of three cubic packings of uniform spheres (simple, body-centered, and face-centered) assuming no particle rotation, employed these results to derive the effective elastic moduli for a statistically isotropic particulate material, and assessed these results by performing numerical discrete element method (DEM) simulations with particle rotations prohibited. In this second part, we explore the effect that particle rotation has on the overall elastic moduli of a statistically isotropic particulate material. We do this both theoretically, by re-analyzing the elementary cells of the three cubic packings with particle rotation allowed, which leads to the introduction of an internal parameter to measure zero-energy rotations at the local level, and numerically via DEM simulations in which particle rotation is unrestrained. We find that the effects of particle rotation cannot be neglected. For unrestrained particle rotation, we find that the self-consistent homogenization assumption applied to the locally body-centered cubic packing incorporating particle rotation effects most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new self-consistent results and theoretical modeling of particle rotation effects together lead to significantly better theoretical predictions of Poisson's ratio than all prior published results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to prior theoretical analyses based on hypotheses involving overall inter-particle contact distributions. Thus, our results permit a direct assessment of the reasons for the theory–experiment discrepancies noted in the literature with regard to previous theoretical derivations of the macroscopic elastic moduli for particulate materials, and our new theoretical results greatly narrow such discrepancies.

Fleischmann, J. A.; Drugan, W. J.; Plesha, M. E.

2013-07-01

188

Jugendkulturen zwischen Globalisierung und Ethnisierung  

Microsoft Academic Search

\\u000a Zusammenfassung  Wie formt sich der Prozess der Globalisierung in den Lebensstilen Jugendlicher aus? Dieser allgemeinen Fragestellung gehen\\u000a wir im folgenden am Beispiel russischer Jugendlicher nach, denn auf der Suche nach Identit?t erfahren russische Jugendliche\\u000a seit der Perestrojka immer st?rker das Kr?ftefeld der westlichen Kultur.\\u000a \\u000a Der folgende Beitrag beschreibt das Verh?ltnis russischer Jugend und Jugendkulturen zur westlichen und schlie?lich zu ihrer\\u000a eigenen

Dirk Villányi; Matthias D. Witte

2004-01-01

189

Parallelizing flow-accumulation calculations on graphics processing units—From iterative DEM preprocessing algorithm to recursive multiple-flow-direction algorithm  

NASA Astrophysics Data System (ADS)

As one of the important tasks in digital terrain analysis, the calculation of flow accumulations from gridded digital elevation models (DEMs) usually involves two steps in a real application: (1) using an iterative DEM preprocessing algorithm to remove the depressions and flat areas commonly contained in real DEMs, and (2) using a recursive flow-direction algorithm to calculate the flow accumulation for every cell in the DEM. Because both algorithms are computationally intensive, quick calculation of the flow accumulations from a DEM (especially for a large area) presents a practical challenge to personal computer (PC) users. In recent years, rapid increases in hardware capacity of the graphics processing units (GPUs) provided in modern PCs have made it possible to meet this challenge in a PC environment. Parallel computing on GPUs using a compute-unified-device-architecture (CUDA) programming model has been explored to speed up the execution of the single-flow-direction algorithm (SFD). However, the parallel implementation on a GPU of the multiple-flow-direction (MFD) algorithm, which generally performs better than the SFD algorithm, has not been reported. Moreover, GPU-based parallelization of the DEM preprocessing step in the flow-accumulation calculations has not been addressed. This paper proposes a parallel approach to calculate flow accumulations (including both iterative DEM preprocessing and a recursive MFD algorithm) on a CUDA-compatible GPU. For the parallelization of an MFD algorithm (MFD-md), two different parallelization strategies using a GPU are explored. The first parallelization strategy, which has been used in the existing parallel SFD algorithm on GPU, has the problem of computing redundancy. Therefore, we designed a parallelization strategy based on graph theory. The application results show that the proposed parallel approach to calculate flow accumulations on a GPU performs much faster than either sequential algorithms or other parallel GPU-based algorithms based on existing parallelization strategies.

Qin, Cheng-Zhi; Zhan, Lijun

2012-06-01

190

Dry coating in a high shear mixer: Comparison of experimental results with DEM analysis of particle motions  

NASA Astrophysics Data System (ADS)

Experimental dry coating of guest particles on the surface of host particles is performed by mechanical forces in a high shear mixer called ``Cyclomix''. The studied system (a mixture of particles of sugar, ``Suglet™'' as host particles and magnesium stearate as guest particles) was chosen as a model one to achieve better understandings of the phenomena during mixing. To simulate the flow of host/guest particles in the mixer, the Discrete Element Method (DEM) was applied. Experimental results such as flowability and wettability can be explained by particles flows evolutions with different rotational speed or duration treatment inside the Cyclomix.

Serris, E.; Sato, A.; Chamayou, A.; Galet, L.; Baron, M.; Grosseau, P.; Thomas, G.

2013-06-01

191

Visualising shear stress distribution inside flow geometries containing pharmaceutical powder excipients using photo stress analysis tomography and DEM simulations  

NASA Astrophysics Data System (ADS)

For the first time, photo stress analysis tomography (PSAT) is applied to probe the distribution of maximum shear stress and direction of major principal stress field within `powder' assemblies inside hopper geometries, and further supported by discrete element model (DEM) simulations. The results show that for decrease in hopper angle, the direction of major principle stress aligns with the direction of gravity which could promote flow rate under dynamic conditions. Conversely, the propensity of developing relatively more non-homogeneous distribution of shear resistance zones inside powder assemblies increases with the hopper angle, which could subsequently decrease their macroscopic flow rate.

Albaraki, Saeed; Antony, S. Joseph.; Arowosola, C. Babatunde

2013-06-01

192

Ring nebulae associated with Wolf-Rayet stars in the Large Magellanic Cloud. II - Kinematics of DEM 45, 137, 165, 174, and 208  

NASA Astrophysics Data System (ADS)

The velocity fields of five ring nebulae associated with Wolf-Rayet stars in the Large Magellanic Cloud are investigated in order to distinguish among possible origins. Velocities were mapped by the use of the CTIO pressure-scanned Fabry-Perot interferometer at the forbidden O III line, and the high-resolution line profiles obtained were used to determine the dynamical ages of the nebulae. Comparison of ring dynamical ages with the age of the Wolf-Rayet star confirms DEM 174 as an amorphous H II region illuminated by the star. DEM 45 and 165 have internal motion less than 10 km/sec, while DEM 137 and 208 are shells expanding at about 15 to 20 km/sec with dynamical ages of several million years. These last four are structured H II regions, and are 10 to 20 times larger than their Galactic counterparts. It is suggested that the two largest rings, DEM 137 and 208, were formed by stellar associations, while DEM 45 and 165 are part of a molecular cloud-H II region complex.

Chu, Y.-H.

1982-04-01

193

Co-seismic landslide topographic analysis based on multi-temporal DEM-A case study of the Wenchuan earthquake.  

PubMed

Hillslope instability has been thought to be one of the most important factors for landslide susceptibility. In this study, we apply geomorphic analysis using multi-temporal DEM data and shake intensity analysis to evaluate the topographic characteristics of the landslide areas. There are many geomorphologic analysis methods such as roughness, slope aspect, which are also as useful as slope analysis. The analyses indicate that most of the co-seismic landslides occurred in regions with roughness, hillslope and slope aspect of >1.2, >30, and between 90 and 270, respectively. However, the intersection regions from the above three methods are more accurate than that derived by applying single topographic analysis method. The ground motion data indicates that the co-seismic landslides mainly occurred on the hanging wall side of Longmen Shan Thrust Belt within the up-down and horizontal peak ground acceleration (PGA) contour of 150 PGA and 200 gal, respectively. The comparisons of pre- and post-earthquake DEM data indicate that the medium roughness and slope increased, the roughest and steepest regions decreased after the Wenchuan earthquake. However, slope aspects did not even change. Our results indicate that co-seismic landslides mainly occurred at specific regions of high roughness, southward and steep sloping areas under strong ground motion. Co-seismic landslides significantly modified the local topography, especially the hillslope and roughness. The roughest relief and steepest slope are significantly smoothed; however, the medium relief and slope become rougher and steeper, respectively. PMID:24171155

Ren, Zhikun; Zhang, Zhuqi; Dai, Fuchu; Yin, Jinhui; Zhang, Huiping

2013-10-17

194

Modeling the motion and orientation of various pharmaceutical tablet shapes in a film coating pan using DEM.  

PubMed

Film coating uniformity is an important quality attribute of pharmaceutical tablets. Large variability in coating thickness can limit process efficiency or cause significant variation in the amount or delivery rate of the active pharmaceutical ingredient to the patient. In this work, the discrete element method (DEM) is used to computationally model the motion and orientation of several novel pharmaceutical tablet shapes in a film coating pan in order to predict coating uniformity. The model predictions are first confirmed with experimental data obtained from an equivalent film coating pan using a machine vision system. The model is then applied to predict coating uniformity for various tablet shapes, pan speeds, and pan loadings. The relative effects of these parameters on both inter- and intra-tablet film coating uniformity are assessed. The DEM results show intra-tablet coating uniformity is strongly influenced by tablet shape, and the extent of this can be predicted by a measure of the tablet shape. The tablet shape is shown to have little effect on the mixing of tablets, and thus, the inter-tablet coating uniformity. The pan rotation speed and pan loading are shown to have a small effect on intra-tablet coating uniformity but a more significant impact on inter-tablet uniformity. These results demonstrate the usefulness of modeling in guiding drug product development decisions such as selection of tablet shape and process operating conditions. PMID:21356296

Ketterhagen, William R

2011-02-26

195

The Discrete Equation Method (DEM) for Fully Compressible, Two-Phase Flows in Ducts of Spatially Varying Cross-Section  

SciTech Connect

For the simulation of light water nuclear reactor coolant flows, general two-phase models (valid for all volume fractions) have been generally used which, while allowing for velocity disequilibrium, normally force pressure equilibrium between the phases (see, for example, the numerous models of this type described in H. Städtke, Gasdynamic Aspects of Two-Phase Flow, Wiley-VCH, 2006). These equations are not hyperbolic, their physical wave dynamics are incorrect, and their solution algorithms rely on dubious truncation error induced artificial viscosity to render them numerically well posed over a portion of the computational spectrum. The inherent problems of the traditional approach to multiphase modeling, which begins with an averaged system of (ill-posed) partial differential equations (PDEs) which are then discretized to form a numerical scheme, are avoided by employing a new homogenization method known as the Discrete Equation Method (DEM) (R. Abgrall and R. Saurel, Discrete Equations for Physical and Numerical Compressible Multiphase Mixtures, J. Comp. Phys. 186, 361-396, 2003). This method results in well-posed hyperbolic systems, this property being important for transient flows. This also allows a clear treatment of non-conservative terms (terms involving interfacial variables and volume fraction gradients) permitting the solution of interface problems without conservation errors, this feature being important for the direct numerical simulation of two-phase flows. Unlike conventional methods, the averaged system of PDEs for the mixture are not used, and the DEM method directly obtains a well-posed discrete equation system from the single-phase conservation laws, producing a numerical scheme which accurately computes fluxes for arbitrary number of phases and solves non-conservative products. The method effectively uses a sequence of single phase Riemann problem solutions. Phase interactions are accounted for by Riemann solvers at each interface. Non-conservative terms are correctly approximated. Some of the closure relations missing from the traditional approach are automatically obtained. Lastly, the continuous equation system resulting from the discrete equations can be identified by taking the continuous limit with weak-wave assumptions. In this work, this approach is tested by constructing a DEM model for the flow of two compressible phases in 1-D ducts of spatially varying cross-section with explicit time integration. An analytical equation of state is included for both water vapor and liquid phases, and a realistic interphase mass transfer model is developed based on interphase heat transfer. A robust compliment of boundary conditions are developed and discussed. Though originally conceived as a first step toward implict time integration of the DEM method (to relieve time step size restrictions due to stiffness and to achieve tighter coupling of equations) in multidimensions, this model offers some unique capabilities for incorporation into next generation light water reactor safety analysis codes. We demonstrate, on a converging-diverging two-phase nozzle, that this well-posed, 2-pressure, 2-velocity DEM model can be integrated to a realistic and meaningful steady-state with both phases treated as compressible.

R. A. Berry; R. Saurel; O. LeMetayer

2010-11-01

196

Machine vision approach to auto-generation of high resolution, continental-scale geomorphometric map from DEM  

NASA Astrophysics Data System (ADS)

Geomorphometric map (GM) is a map of landforms delineated exclusively on the basis of their morphology; it depicts a classification of landscape into its constituent elements. GM is a valuable tool for visual terrain analysis, but more importantly, it's a perfect terrain representation for its further algorithmic analysis. GMs themselves are auto-generated from DEM. We have developed a new technique for auto-generation of GMs that is based on the principle of machine vision. Such approach approximates more closely the mapping process of human analyst and results in an efficient generation of GMs having quality and utility superior to maps generated by a standard technique based on differential geometry. The core of the new technique is a notion of geomorphon. A geomorphon is a relief-invariant, orientation-invariant, and size-flexible abstracted elementary unit of terrain. It is calculated from DEM using simple ternary patterns defined on a neighborhood which size adapts to the character of local terrain. Geomorphons are both terrain attributes and landform types at the same time; they allow for a direct and highly efficient, single-step classification and mapping of landforms. There are 498 unique geomorphons but only a small fraction of them are found in typical natural terrain. The geomorphon-based mapping technique is implemented as a GRASS GIS extension written in ANSI C and will be available in the public domain. In order to showcase the capabilities of geomorphons we have calculated the GM for the entire conterminous United States from the 30m/pixel NED DEM. The map shows ten most abundant landforms: flat, peak, ridge, shoulder, spur, slope, hollow, footslope, valley, and pit; a lookup table was used to assign each of the remaining 488 infrequent forms to a morphologically closest mapped form. The result is a unique, never before seen, type of map that clearly shows multiple geomorphic features and indicates the underlying geologic processes. The auto-generation of GM from this high resolution, continental size raster having 168000x104000 cells took 60 hours on a single processor computer. Future applications of such GM include coupling it with a search tool capable of querying the continental-scale GM in order to identify all instances of a given type of local landscape.

Jasiewicz, J.; Stepinski, T. F.

2012-04-01

197

DEM-PFV analysis of solid-fluid transition in granular sediments under the action of waves  

NASA Astrophysics Data System (ADS)

Solid-fluid transition is a very active area of investigations. It is linked to many applications in geomechanics and near-shore or off-shore engineering. Micromechanical models can give useful insight into the governing mechanisms of this phenomenon, provided they can reflect the role of pore fluids accurately. We present the application of a new hydromechanical model, combining the Discrete Element Method (DEM) to a flow model based on a pore-scale discretization in finite volumes (PFV) for incompressible pore fluids, to simulate the response of near-shore granular sediments subjected to the action of stationary waves. The model reproduces a wide range of physical processes observed in the experiments, including temporary liquefaction events.

Catalano, E.; Chareyre, B.; Barthélémy, E.

2013-06-01

198

The Effects of the Terrain Variation and Changed Parameters of the Moving Window on the LIDAR DEM Spectrum  

NASA Astrophysics Data System (ADS)

LIDAR (Light Detection And Ranging) data has become a highly used data source for modelling the terrain surface in recent years. In comparison to other surveying techniques, LIDAR measurements provide much denser (and affordable) sampling of the terrain in an automated manner. Higher density of data points results also in the better spatial resolution of DEMs (Digital Elevation Model) generated from these data. Fourier transform (FT) is a technique for transforming the terrain information from the spatial into the frequency domain. Higher spatial resolution of the DEM enables more local approach for analyzing the terrain surface with the FT, since even for a smaller area many (enough) sampling points are given. In this study 2D discrete Fast Fourier Transform (as implemented in MatLab) is applied to LIDAR DEM with a cell size of 0.5 m and therefore with a spatial resolution - in Fourier terminology - of 1.0 m. The chosen study area has different terrain characteristics, such as: different orientation of the lineaments, different aspects, different roughness. Our approach is to analyze the spectrum of the series of subareas ("moving window") of the DEM. This enables studying the response to the changes of different variables in the frequency domain. The changing variables were: (1) the size of the transformed area, (2) the offset between different positions of moving window, and (3) the orientation of the landforms with the respect to the moving window. Changes in all the variables influence the spectral information. We focus more on the results of changing the offset between moving windows, since these analysis are less explored. These offset changes reflect as the changes in the frequency domain due to a new relief structures included in the moving window. Additionally, the possibilities for visualization of spectral information were explored. The purpose was to find an appropriate way to visualize a series of FT, which would raise the understanding of the relations between the changes in spatial domain and the responses in the frequency domain. Good results were achieved for visualizing the amplitude but for the phase information further investigation is suggested. From geomorphometric point of view, the results can be interpreted as inherent properties of the terrain that was shaped by various endogenic and exogenic processes through longer time periods. Faulting and folding typically create quasi-linear or curvilinear features; they can be enhanced further by erosion, forming larger valley patterns. On the other hand, sedimentary processes tend to smooth the surface, by covering negative forms with sediments. Glaciation, as it is reshaping the current surface very rapidly, may modify the spatial spectrum considerably, removing higher frequency components. Post-glacial surface may inherit those properties and maintain them for longer time. Moving window FFT spectra are able to enhance hidden context (e.g., fault patterns), and rotation or deformation of original patterns can also be reflected in the succession of 2D Fourier spectra.

Vre?ko, A.; Kovacs, G.; Podobnikar, T.; Székely, B.

2012-04-01

199

Evaluation of morphometric parameters of drainage networks derived from topographic maps and DEM in point of floods  

NASA Astrophysics Data System (ADS)

An evaluation of morphometric parameters of two drainage networks derived from different sources was done to determine the influence of sub-basins to flooding on the main channel in the Havran River basin (Bal?kesir-Turkey). Drainage networks for the sub-basins were derived from both topographic maps scaled 1:25.000 and a 10-m resolution digital elevation model (DEM) using geographic information systems (GIS). Blue lines, representing fluvial channels on the topographic maps were accepted as a drainage network, which does not depict all exterior links in the basin. The second drainage network was extracted from the DEM using minimum accumulation area threshold to include all exterior links. Morphometric parameters were applied to the two types of drainage networks at sub-basin levels. These parameters were used to assess the influence of the sub-basins on the main channel with respect to flooding. The results show that the drainage network of sub-basin 4—where a dam was constructed on its outlet to mitigate potential floods—has a lower influence morphometrically to produce probable floods on the main channel than that of sub-basins 1, 3, and 5. The construction of the dam will help reduce flooding on the main channel from sub-basin 4 but it will not prevent potential flooding from sub-basin 1, 3 and 5, which join the main channel downstream of sub-basin 4. Therefore, flood mitigation efforts should be considered in order to protect the settlement and agricultural lands on the floodplain downstream of the dam. In order to increase our understanding of flood hazards, and to determine appropriate mitigation solutions, drainage morphometry research should be included as an essential component to hydrologic studies.

Ozdemir, Hasan; Bird, Deanne

2009-02-01

200

The impact of porosity and crack density on the elasticity, strength and friction of cohesive granular materials: Insights from DEM modelling  

Microsoft Academic Search

This study uses the Discrete Element Method (DEM), in which rock is represented by bonded, spherical particles, to investigate the dependence of elasticity, strength and friction angle on porosity and crack density. A series of confined triaxial extension and compression tests were performed on samples that were generated with different particle packing methods, characterised by differing particle size distributions and

Martin P. J. Schöpfer; Steffen Abe; Conrad Childs; John J. Walsh

2009-01-01

201

EFFECTS OF DEM SOURCE AND RESOLUTION ON WEPP HYDROLOGIC AND EROSION SIMULATION: A CASE STUDY OF TWO FOREST WATERSHEDS IN NORTHERN IDAHO  

Microsoft Academic Search

The recent modification of the Water Erosion Prediction Project (WEPP) model has improved its applicability to hydrology and erosion modeling in forest watersheds. To generate reliable topographic and hydrologic inputs for the WEPP model, carefully selecting digital elevation models (DEMs) with appropriate resolution and accuracy is essential because topography is a major factor controlling water erosion. Light detection and ranging

J. X. Zhang; J. Q. Wu; K. Chang; W. J. Elliot; S. Dun

202

Fonctionnaires d'État et bourgeoisie urbaine en Allemagne  

Microsoft Academic Search

[ger] Der Beitrag resümiert die Debatte in der deutschen Geschichtswissenschaft um Stadt und Bürgertum in der Neuzeit und ihre Bedeutung für die Entwicklung moderner politischer Institutionen. Ausgehend von der Frage, wie sich das Verhdltnis zwischen den Amtsträgern der erstarkenden Territorialstaaten und den stadtbürgerlichen Eliten zwischen dem 16. und dem 19. Jahrhundert gestaltete, wird der Wandel der politischen Kultur um 1800

Stefan Brakensiek

2005-01-01

203

Secular changes in the stature of adults and the secular trend of the modern sugar consumption  

Microsoft Academic Search

1.Die zwischen dem säkularen Trend des Zuckerkonsums und dem säkularen Trend der Acceleration bestehende Korrelation, auf die ich in meiner Monographie hingewiesen hatte, wird durch eine Hypothese über das pathophysiologische Geschehen zu erklären versucht.2.Am Beispiel verschiedener Länder (Niederlande, Schweden, Norwegen, Dänemark, England) wird gezeigt, daß eine solche Korrelation offenbar auch zwischen den säkularen Schwankungen des Zuckerkonsums und denjenigen der jeweiligen

Eugen Ziegler

1967-01-01

204

Terrain Classification of Aster gDEM for Seismic Microzonation of Port-Au Haiti, Using - and - Based Analytic Methods  

NASA Astrophysics Data System (ADS)

The aftermath of the M7.0 Haiti earthquake of 12 January 2010 witnessed an impressive scientific response from the international community. In addition to conventional post-earthquake investigations, there was also an unprecedented reliance on remote-sensing technologies for scientific investigation and damage assessment. These technologies include sensors from both aerial and space-borne observational platforms. As part of the Haiti earthquake response and recovery effort, we develop a seismic zonation map of Port-au-Prince based on high-resolution satellite imagery as well as data from traditional seismographic monitoring stations and geotechnical site characterizations. Our imagery consists of a global digital elevation model (gDEM) of Hispaniola derived from data recorded by NASA-JPL's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the multi-platform satellite Terra. To develop our model we also consider recorded waveforms from portable seismographic stations (Hough et al., in review) and 36 geotechnical shear-wave velocity surveys (Cox et al., in review). Following a similar approach developed by Yong et al. (2008; Bull. Seism Soc. Am.), we use both pixel- and object- based imaging analytic methods to systematically identify and extract local terrain features that are expected to amplify seismic ground motion. Using histogram-stretching techniques applied to the rDEM values, followed by multi-resolution, segmentations of the imagery into terrain types, we systematically classify the terrains of Hispaniola. By associating available Vs30 (average shear-wave velocity in the upper 30 meter depth) calculated from the MASW (Multi-channel Analysis of Surface Wave) survey method, we develop a first-order site characterization map. Our results indicate that the terrain-based Vs30 estimates are significantly associated with amplitudes recorded at station sites. We also find that the damage distribution inferred from UNOSAT (UNITAR Operational Satellite Applications Program) data matches our estimates. However, the strongest amplifications are observed at two stations on a foothill ridge, where Vs30 values indicate that amplification should be relatively lower. Hough et al. (2010, this session) conclude that the observations can be explained by topographic amplification along a steep, narrow ridge. On the basis of these preliminary results, we conclude that the terrain-based framework, which characterizes topographic amplification as well as sediment-induced amplification, is needed to develop a microzonation map for Port-au-Prince.

Yong, A.; Hough, S. E.; Cox, B. R.; Rathje, E. M.; Bachhuber, J.; Hulslander, D.; Christiansen, L.; Abrams, M.

2010-12-01

205

Muldrow Glacier and the effect of debris cover on geodetic volume change estimates from DEM and LiDAR elevation measurements  

NASA Astrophysics Data System (ADS)

Since 1993, the University of Alaska (UAF) Glaciers Group has monitored glacier volume changes across Alaska and northern Canada using light aircraft laser altimetry surveys. These surveys are currently part of NASA's Operation IceBridge. As part of the ongoing study, we examine the volume and topography changes in Muldrow Glacier, located in the Central Alaska Range, from 1952 through 2010 using a combination of DEMs, centerline laser altimetry (1994, 2001, and 2008) and LiDAR data (2010), and debris cover maps. Current data show that the volume loss rate for Muldrow Glacier has increased significantly during this period from a mean rate of ~-0.02 km3/yr from 1952 to 1976 to a mean rate of ~-0.19 km3/yr from 2008 to 2010. Flight path laser altimetry data are used to track elevations when no DEM data are available. Laser altimetry and LiDAR measure elevation changes along the centerline of the glacier with an accuracy of ±30cm and are then extrapolated over the entire glacier using the best available DEM. Debris cover on glaciers often has significant and spatially variable effects on the melt rate of glaciers. Due to the spatial variability of debris cover on a glacier, it can represent a source of uncertainty when extrapolating the centerline elevation data to the entire glacier. In order to improve the extrapolation of the centerline elevation data for all glaciers currently being surveyed by UAF, we concentrate on the elevation changes of and spatial distribution of rock debris on Muldrow Glacier. We compare elevation changes based on DEMs from 1952 (from the National Elevation Database), 1976 (a digitized version of Bradford Washburn's topographic map of Muldrow), and 2006 (from AeroMetric, Inc.). We use debris field maps acquired during the mid-1970s and ~2006 in combination with the DEMs to investigate the insulation effects of debris on differential melt rates across the glacier. By also comparing the DEM and debris cover data with data from the aircraft laser altimetry and LiDAR surveys, we can better estimate the effect of surface debris on the volume changes estimated from the centerline elevation changes for all debris-covered glaciers included in these surveys.

Murphy, N.; Larsen, C. F.; Herreid, S. J.

2011-12-01

206

Optimization of operating conditions in a high-shear mixer using dem model: determination of optimal fill level.  

PubMed

For the purpose of evaluating optimal fill level of starting materials in a high-shear mixer, discrete element method (DEM) simulation was conducted to visualize kinetic status between particles. The simulation results obtained by changing fill levels were used to determine solid fraction of particles, particle velocity, particle velocity vector, and kinetic energy and discuss the flow pattern. Optimal fill level was obtained from the information on these matters. It was pointed out that understanding the kinetic energy between particles in an agitating vessel was effective in determining the optimal fill level. Granulation experiment was conducted to validate the optimal fill level obtained by the simulation, confirming the good agreement between these two results. It was pointed out that determination of kinetic energy between particles through the simulation was effective in obtaining an index of the kinetic status of particles. Further, it was confirmed that the simulation could provide more information than conventional granulation experiments could provide and also helpful in optimizing the operating conditions. PMID:12499588

Terashita, Keijiro; Nishimura, Takehiko; Natsuyama, Susumu

2002-12-01

207

Investigation of Landslide from Deformation - Comparison of High Resolution DEM, Aero Photos Using Long Wave Length DInSAR  

NASA Astrophysics Data System (ADS)

Landslide is one of the common natural hazards in Taiwan, especially in central Taiwan with high elevation and steep terrain. Rainfall is increasing both in accumulation and intensity after 2000. Severe landslide events after Chi Chi earthquake are including typhoon Toraj, typhoon Mindulle, 69 heavy rainfall, typhoon Sinlaku, and typhoon Morakot. However, these landslides could be unstable or deformed after rainfall and sliding in next events. The major purpose of this study is to find these deformed but not slide out slopes but slip in following events. For this objective, differential interferometry synthetic aperture radar (DInSAR) is adopted and an event after 69 heavy rainfall is selected for this research. The vegetation in Taiwan is very well thus wave length of SAR needs as long as possible to penetrate vegetation to reach ground surface. ALOS PALSAR HH image is used in this research to derive fringe in study area. The Study area ranges from Puli in south and Wulin in north, including May River basin, Lushan hot spring area, Chingjing area, and Tsuiluan area. The result shows appropriate relationship between the founded deformed slope from DInSAR and landslip in following event. Also high resolution DEM and aero photos are used to derive topography and landslide identification. The results also show that the process can be reference to produce landslide susceptibility map.

Wang, Kuo-Lung; Lin, Jun-Tin; Lin, Meei-Ling; Lin, Ching-Wee; Chen, Tien-Chien; Tseng, Chih-Ming; Chen, Hongey; Lin, Sheng-Chi

2013-04-01

208

Electrochemical behavior of sodium azide at Pt and Au electrodes in sodium sulfate electrolyte: A DEMS study  

SciTech Connect

Azides are widely used in chemical technology for a large variety of applications, such as detonators (Pb(N{sub 3}){sub 2}), getters in electric discharge tubes, anticorrosive agents, or additives for the production of foam rubber. The electro-oxidation and -reduction of sodium azide at porous painted platinum and gold electrodes was studied using the multipurpose electrochemical mass spectrometry (MPEMS) which was operated in the differential electrochemical mass spectrometry (DEMS) mode. The platinum electrode was found to be active for electro-oxidation as well as for electroreduction. Above 0.3 V vs. Hg/Hg{sub 2}SO{sub 4}, azide is oxidized to give N{sub 2}, NO, NO{sub 2}, and N{sub 2}O. Reduction of azide takes place below {minus}0.9 V forming N{sub 2}, N{sub 2}H{sub 4}, and possibly NH{sub 3}. In contrast to platinum, gold showed only activity for the electro-oxidation of azide leading to the formation of N{sub 2}, NO, NO{sub 2}, and N{sub 2}O above 0.5 V. Evidence for a reaction without evolution of volatile products was also found taking place above 0.1 V. A reaction mechanism is discussed emphasizing the role of adsorbed hydrogen and oxygen.

Dalmia, A.; Wasmus, S.; Savinell, R.F.; Liu, C.C. [Case Western Reserve Univ., Cleveland, OH (United States)

1995-11-01

209

The Physics of Supernova Remnant Blast Waves. II. Electron-Ion Equilibration in DEM L71 in the Large Magellanic Cloud  

Microsoft Academic Search

We present analysis and modeling of X-ray spectra from the blast wave shock of DEM L71 in the Large Magellanic Cloud. This remnant exhibits widespread Balmer-dominated emission characteristic of nonradiative shocks in partially neutral gas. We have used Chandra ACIS-S data and optical Fabry-Pérot spectra of the blast wave to measure the electron and proton temperatures, respectively. In principle, when

Cara E. Rakowski; Parviz Ghavamian; John P. Hughes

2003-01-01

210

Simulation of lake–aquifer interaction at Lake Naivasha, Kenya using a three-dimensional flow model with the high conductivity technique and a DEM with bathymetry  

NASA Astrophysics Data System (ADS)

A 3D ground water flow model is used to simulate the lake aquifer interaction.A DEM with 30 m resolution was used to improve the 3-D representation of the lake.The lake is considered as a high hydraulic conductivity in the modeling framework.The simplicity of the model approach can be implemented with existing preprocessor.The calibration process was carried out using pilot points and regularization.

Yihdego, Yohannes; Becht, Robert

2013-10-01

211

Shear behaviour in numerical triaxial compression tests by 3D fluid-coupled DEM: a fundamental study on mechanisms of landslide initiation  

Microsoft Academic Search

Shear behaviour in triaxial compression tests was numerically examined by 3D fluid-coupled DEM in a fundamental study on the\\u000a mechanisms of landslide initiation. Changes in pore-water pressure because of undrained compression were calculated by introducing\\u000a a measurement sphere surrounding a ball which represented the soil particles. The pore-water pressure was assigned to the\\u000a measurement sphere as the product of the

Yasuhiko Okada

2011-01-01

212

Coastal flood risk analysis using landsat-7 ETM+ imagery and SRTM DEM: a case study of Izmir, Turkey.  

PubMed

The Intergovernmental Panel on Climate Change (IPCC) reports an acceleration of the global mean sea-level rise (MSLR) in the twentieth century in response to global climate change. If this acceleration remains constant, then some coastal areas are most likely to be inundated by the year 2100. The ability to identify the differential vulnerability of coastlines to future inundation hazards as result of global climate change is necessary for timely actions to be taken. Yildiz et al. (Journal of Mapping, 17, 1-75, 2003) reported that the local MSLR in the city of Izmir rose at a rate of 6.8 +/- 0.9 mm year(-1) between 1984 and 2002. In this study, the spatial distribution of the coastal inundation hazards of Izmir region was determined using not only land-use and land-cover (LULC) types derived from the maximum likelihood classification of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) multi-spectral image set but also the classification of the digital elevation model (DEM) acquired by the shuttle radar topography mission (SRTM). Coastal areas with elevations of 2 and 5 m above mean sea-level vulnerable to inundation were found to cover 2.1 and 3.7% of the study region (6,107 km(2)), respectively. Our findings revealed that Menemen plain along Gediz river, and the settlements of Karsiyaka, Alacati, Aliaga, Candarli and Selcuk are at high risk in order of decreasing vulnerability to permanent and episodic inundation by 2100 under the high MSLR scenarios of 20 to 50 mm year(-1). PMID:17171268

Demirkesen, A C; Evrendilek, F; Berberoglu, S; Kilic, S

2006-12-14

213

Lineament Mapping for Hydrogeological Characterization of Volcanic Terrains Using Products Derived from DEMs, Radar, Landsat and Aster Imagery  

NASA Astrophysics Data System (ADS)

Remote sensing techniques can be used in the characterization of landscapes for assessing groundwater resources. Expressions of the subsurface geological conditions, such as faulting, qualitative proximity of the groundwater table to the surface, and changes in bedrock geology, can be inferred from satellite imagery. Products obtained from satellite imagery can identify areas of higher potential for more detailed water resources exploration activities, such as surface geophysics, hydrochemistry and hydraulic analysis to be focus on these priority areas. Lineament mapping has been the most common application of remotely sensed imagery to delineate places for geophysical studies and well drilling. A remote sensing-based protocol is presented for characterizing fracture networks, discontinuities and boundaries of local and regional aquifer systems, and to evaluate their control on natural hydrological behavior and well yields in volcanic aquifers. The protocol is tested using satellite imagery (RADARSAT-1, Landsat TM and ETM+, Aster) and two DEMs (30- and 90-m spatial resolutions) applied to the Quito Aquifer System (QAS). The aquifer is located in the Central Inter-Andean Valley of Ecuador, a region affected by active volcanism and faulting and characterized by basins filled with series of volcanic deposits and primary and reworked sedimentary rocks. Coincidence analysis was applied after initial processing and interpretation to obtain a lineament map of the study areas. By combining our results with those from previous geological studies and hydrogeological data, a pattern of fracturing that is affecting the hydrogeology of the QAS can be distinguished and an improved understanding of the regional flow systems was gained.

Rios-Sanchez, M.; Gierke, J. S.; Muñoz-Martínez, T.

2010-12-01

214

Validating the DemTect with 18-Fluoro-2DeoxyGlucose Positron Emission Tomography as a Sensitive Neuropsychological Screening Test for Early Alzheimer Disease in Patients of a Memory Clinic  

Microsoft Academic Search

Objectives: The first study to validate the diagnostic value of the DemTect, a short neuropsychological screening test for dementia (8–10 min), using 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in patients of a memory clinic. Methods: DemTect results were compared to the clinical diagnosis and to FDG-PET as a reference method for the early in vivo detection of Alzheimer’s disease (AD). Results:

Armin Scheurich; Matthias J. Müller; Thomas Siessmeier; Peter Bartenstein; Lutz G. Schmidt; Andreas Fellgiebel

2005-01-01

215

InSAR-DEM analyses integrated with geologic field methods for the study of long-term seismogenic fault behavior: Applications in the axial zone of the central Apennines (Italy)  

Microsoft Academic Search

The integration of terrain computer modeling with field methods may provide a powerful mechanism for understanding active faults geometry, kinematics and long-term fault behavior. Radar interferometry was used on ERS tandem images to create a geocoded DEM (InSAR-DEM) with a nominal 20-m spatial-resolution of the central Apennines axial zone, a seismically active area characterized by historical destructive earthquakes with M

A. Pizzi; G. Pugliese

2004-01-01

216

DEMS 4th period  

NSDL National Science Digital Library

Today, you are going to practice finding multiples and adding fractions! FIRST, you will practice finding multiples with the Mayor of Pumpkinville. You will START with finding multiples of 2. THEN, you will find multiples of 3 through 12. Once you have TEN multiples of EACH number, you may move to the next game! GOOD LUCK! CLICK HERE -->Pumpkin Multiples Once you have ...

Smith, Ms.

2009-02-14

217

Studium der Stationären und Laufenden Schichtung in der Entladung in Neon Mit Hilfe eines Lokalen Hochfrequenzfeldes  

Microsoft Academic Search

Zusammenfassung Es wurde ein Verfahren zur Erregung von stationären Schichten, der Schichtungswelle und der laufenden Schichten in der Gleichstromentladung ausgearbeitet, das auf der Einwirkung eines Hochfrequenzfeldes auf einen kurzen Abschnitt der positiven Säule beruht. Dieses Verfahren wurde zum Studium aller drei angeführten Schichtungsarten in Neon benützt, insbesondere jedoch zum Studium des Zusammenhanges zwischen den laufenden und den stationären Schichten.

M. Šícha; V. Veselý; J. Studnicka; J. Prostejovský; M. Novák

1962-01-01

218

Pockenschutzimpfung und Schwangerschaft--eine Übersicht  

Microsoft Academic Search

|Die Letalitätsrate bei Variola major betrug für adäquat Geimpfte etwa 3%, für Ungeimpfte – ungeachtet des Krankheitsverlaufes – etwa 30–40%. Die Letalität der hämorrhagischen Pocken liegt über 90%. In der Schwangerschaft verlaufen die Pocken in 30–50% der Fälle primär hämorrhagisch. Die Pockeninfektion in der Schwangerschaft geht mit einer erhöhten Abort-, Totgeburten- und Frühgeburtenrate einher.Ein Zusammenhang zwischen Pocken in der Schwangerschaft

M. Enders; S. Essbauer; H. Meyer

2003-01-01

219

Geschlechterunterschiede in islamischer Religiosität und Geschlechterrollenwerten: Ein Vergleich der Zusammenhänge am Beispiel der türkischen und marokkanischen zweiten Generation in Belgien  

Microsoft Academic Search

In Anlehnung an die Debatte über den Einfluss von (islamischer) Religiosität auf Geschlechterrollenwerte, untersucht dieser Beitrag den Zusammenhang zwischen Religiosität und Geschlechterrollenwerten bei Männern und Frauen der türkischen und marokkanischen zweiten Generation in Belgien. Dazu wurde zunächst ein theoretisches Modell islamischer Religiosität entwickelt, welches aus den Elementen religiöse Identifikation, (teilweise geschlechtsspezifische) religiöse Praktiken und orthodoxer Glaube besteht. Anhand von Umfragedaten

Jana Anne Scheible; Fenella Fleischmann

2011-01-01

220

Elastischer Halbraum mit unendlich langein Biegeträger  

Microsoft Academic Search

Das Zusammenwirken von Biegeträger und Halbraum wird mit Hilfe der Fouriertransformation untersucht. Eine sin- oder cos-förmige Streifenlast ruft sowohl am Träger wie auch auf der Oberfläche des elastischen Halbraumes eine in Trägerlängsrichtung sinoder cos-förmige Verformung hervor. Wenn durch Auswertung der Einflußfläche für die Durchsenkung der Halbraumoberfläche der Zusammenhang zwischen Last- und Verformungsamplitude gewonnen ist, kann das Zusammenwirken von Träger und

H. Kreuzinger; A. Konrad

1986-01-01

221

Statistical investigations on the relation between the ultra-violet rays of the sun and spasmophilic convulsions  

Microsoft Academic Search

Zusammenfassung Ein Zusammenhang zwischen meteorologischen Faktoren und Spasmophilie gilt bisher als nicht bewiesen. Die Verfasser haben diese Frage neu aufgegriffen und dabei folgendes gefunden: Tage, an denen Tetanieanfälle auftreten (33 Fälle), unterscheiden sich von beliebigen andern Tagen dadurch, daß sie auf eine durchschnittlich viermal größere Sonnenstrahlungsdauer während der vorausgehenden 10 Tage folgen. Die Verfasser haben weiterhin den Ultraviolettgehalt des Tageslichtes

E. Sartori; M. Bolletti

1948-01-01

222

Activity of Nyiragongo and Nyamulagira Volcanoes (Dem. Rep. of Congo) Revealed Using Geological, Geophysical and InSAR data  

NASA Astrophysics Data System (ADS)

Ground-based monitoring of active volcanoes in Africa can be problematic due to political instabilities, safety issues and poor accessibility. Remote-sensing techniques such as Differential Interferometric Synthetic Aperture Radar (DInSAR, more commonly InSAR), are therefore very useful and provide robust observational tools for natural hazard assessment, regardless of local conditions. Nyiragongo and Nyamulagira volcanoes (which experienced nine eruptions from December 1996 to January 2010) are located in the western branch of the East African Rift (Virunga Volcanic Province, North Kivu, Dem. Rep. of Congo). InSAR has recorded ground displacements related to most of the tectonic and volcanic events that have occurred since 1996 using SAR images from the JERS, ERS-1/2, ENVISAT, RADARSAT-1, RADARSAT-2 and ALOS satellites. This database provides excellent spatial and temporal resolution of deformation, leading to insights into tectonic and volcanic processes. Loss of coherence within the SAR signal due to rapid-changing equatorial vegetation hampers the use of InSAR as a volcano-tectonic monitoring tool. We partially overcome this limitation using 1) a large number of SAR images, including about 150 ENVISAT and more than 100 RADARSAT-1 images, 2) short repeat times of 24 and 35 days for RADARSAT-1 and ENVISAT, respectively, and 3) satellites with longer wavelengths, such as JERS and ALOS. Using a large dataset combining short revisit time SAR images significantly increases the chances of producing interferograms with good coherence. A longer wavelength radar signal better penetrates vegetation cover, also increasing coherence. Furthermore, useful data were retrieved in low-coherence areas by applying the “StaMPS” (Stanford Method for Persistent Scatterers) method, which combines a small baseline and persistent scatterers approach, to our largest SAR datasets. Using several look angles from both ascending and descending orbital tracks, we were able to characterize the 3D ground displacement field. A 3D Mixed Boundary Element Method is used to infer geometry and physical characteristics of the sources controlling volcanic unrest and tectonic activity. In addition, we combined our InSAR database with other available data, such as seismicity from a network maintained since 2002 and results from geological and geophysical surveys from the volcanoes, to better constrain source processes. The improved understanding and constraints on volcanic processes in the North Kivu area made possible by this multidisciplinary approach will be highlighted with a few case studies of recent volcanic activity.

Wauthier, C.; Cayol, V.; Hooper, A.; Kervyn, F.; Marinkovic, P.; D'Oreye, N.; Poland, M. P.

2010-12-01

223

Differential Movement across Byrd Glacier, Transantarctic Mountains, Antarctica: A combined (U-Th)/He and DEM Analysis  

NASA Astrophysics Data System (ADS)

Byrd Glacier, a major outlet glacier crossing the Transantarctic Mountains (TAM), marks a major discontinuity in the Neoproterozoic-early Paleozoic Ross orogen, with plutonic and upper-amphibolite metamorphic rocks to the north and folded limestones and conglomerates to the south. The objectives of this study are to assess possible differential movement across an inferred fault under Byrd Glacier, measure the timing of unroofing, and gain an overall better understanding of the architecture of the TAM. One datum for assessing possible differential movement in this area is the Kukri peneplain: an unconformity on the Ross basement rocks, which is overlain by Devonian to Triassic sediments and only mildly deformed. To determine the timing of unroofing, euhedral apatites separated from rock samples collected from a variety of elevations and locations north and south of Byrd Glacier were dated using single crystal (U-Th)/He thermochronology. The (U-Th)/He data reveal distinct cooling histories north and south of Byrd Glacier. Data on age vs. elevation plots indicate an offset of ~1 km across Byrd Glacier with a common denudation rate of ~0.04 mm/yr between 180 - 40 Ma. Two models plausibly explain this geochronologic data. In the first model, a relative uniform unroofing across Byrd Glacier is offset by later fault displacement; the second model involves differential unroofing with the north side exhumed earlier than the south side. To test the relative merits of these models, we utilize the Kukri peneplain. A Landsat image of the Byrd Glacier area was overlain on Aster Global DEM data and spot elevations of the Kukri peneplain to the north and south of Byrd Glacier were mapped where possible. The difference in elevation of the peneplain as projected in a cross section across Byrd Glacier shows an offset of approximately 550 m. The results of this study suggest a model of relatively uniform unroofing with later fault displacement that uplifted the south side relative to the north side. This method of combining geochronologic and remote geomorphic analysis, utilizing a peneplain as a datum, has provided insight into a likely unroofing model, denudation history, and better understanding of differential movement, which can complement other thermochronologic studies elsewhere within the TAM.

Foley, D. J.; Stump, E.; van Soest, M. C.; Whipple, K. X.; Hodges, K.

2010-12-01

224

Application of high resolution DEM data to detect rock damage from geomorphic signals along the central San Jacinto Fault  

NASA Astrophysics Data System (ADS)

We analyze geomorphic properties extracted from LiDAR and SRTM (Shuttle Radar Topography Mission) data to test whether the damage zone along the central San Jacinto Fault (SJF) zone can be resolved with remotely-sensed data in a quantitative fashion. The SJF is one of the most active faults in southern California, with well expressed geomorphology and a fast slip rate, as seen in the geology and by GPS. We use ArcMap and the TauDEM toolbox to compare several morphometric parameters, including drainage density (Dd), on both sides of the fault, using a 1 km and a 5 km buffer for the LiDAR and SRTM data, respectively. We also analyze the spatial patterns of Dd near the fault, using two different definitions of spatial Dd. The high resolution of the LiDAR data allows us to focus on a single fault, eliminating the effects of parallel nearby faults. From the LiDAR data we find that the highest Dd values occur in areas between two fault strands, followed generally by rocks on the northeast side of the fault, with the lowest Dd values occurring on the southwest side of the fault. The SRTM data shows a band of high Dd values centered on the main fault trace with ~ 1 km width. Our results indicate that there is a strong correlation between drainage density and proximity to the fault, with zones of structural complexity along the fault displaying the highest Dd. We interpret this to largely be an effect of degree of rock damage, as these are areas that are expected to be more damaged, and field observations support this contention. If we are correct, then it appears that the northeast side of the SJF is generally more damaged. South of the trifurcation area there is evidence that the signal is reversed on the larger scale, with more damage on the southwest side of the fault inferred from the SRTM data, possibly caused by extension between the Coyote Creek and Clark faults. The implications of the observed asymmetry could be geological evidence for rupture propagation direction, because a preferred propagation direction is predicted to produce asymmetric damage structure that would be recorded in the volume of rock surrounding a fault.

Wechsler, Neta; Rockwell, Thomas K.; Ben-Zion, Yehuda

2009-12-01

225

Snow surface height change in Dome-A from 2003 to 2008 based on ICESat/GLAS and DEM generated from GPS  

NASA Astrophysics Data System (ADS)

Dome A is the summit in Antarctic ice sheet. In this paper, snow accumulation from 2003 to 2008 in this area of about 20 km×20 km was derived for the first time with ICESat/GLAS data and local DEM, produced with GPS data collected in 2008. Four tracks data covering this region from 2003 to 2009 were selected for later use. This paper primarily introduced the method and final results. To get high quality ICESat/GLAS data, quality-control measures were firstly taken to exclude those highly saturated footprints or those affected by cloud. Secondly, an improved method to obtain Snow Surface-Height Changes (SSHC) based on GPS DEM and GLAS data was put forward. The basic principle is to convert ICESat data from elevation data with datum of Topex/Poseidon to relative elevation data with datum of a local DEM. Thirdly, Snow Surface Height Change (SSHC) tendency in a grid of 300 m×300 m was calculated if footprints in the grid were from more than six different campaigns (Figure 1). Fourthly, the tendency of SSHC in Dome-A region from 2003 to 2008 was given as an average of all grid data and snow accumulation rate of about 3.2±1.2 cm a-1 is derived, corresponding to 0.6±0.2 cm w e a-1. Snow accumulation from automatic weather station (AWS) data from 2005 to 2008 is used to make comparison with that from GLAS data at a buffer area of 2 km centered at the Dome-A AWS. Correlation coefficient between them is 0.80 for two GLAS tracks when a 9-day average of AWS data was adopted. The lower correlation coefficient may be owing to location difference because AWS is not covered by any ICESat footprints.

Wang, X.; Cheng, X.; Gong, P.; Li, Z.; Huang, H.; Hui, F.; Li, X.

2011-12-01

226

An integrated Quality by Design (QbD) approach towards design space definition of a blending unit operation by Discrete Element Method (DEM) simulation.  

PubMed

A combined Quality by Design (QbD) and Discrete Element Model (DEM) simulation-approach is presented to characterize a blending unit operation by evaluating the impact of formulation parameters and process variables on the blending quality and blending end point. Understanding the variability of both the API and the excipients, as well as their impact on the blending process are critical elements for blending QbD. In a first step, the QbD-methodology is systematically used to (1) establish the critical quality attribute content uniformity and to link this CQA to its surrogate blend homogeneity, (2) identify potentially critical input factors that may affect blending operation quality and (3) risk-rank these factors to define activities for process characterization. Subsequently, a DEM-simulation-based characterization of the blending process is performed. A statistical evaluation is finally presented, relating blend homogeneity of systems with low particle number to the regulatory requirements. Data are then used to map out a three-dimensional knowledge space, providing parameters to define a design space and set up an appropriate control strategy. PMID:21056102

Adam, Siegfried; Suzzi, Daniele; Radeke, Charles; Khinast, Johannes G

2010-11-04

227

A GIS modeled DEM-based hydrologic watershed network of the Greenland Ice Sheet and non-ice land surface areas  

NASA Astrophysics Data System (ADS)

Increased mass loss of the Greenland Ice Sheet and subsequent global sea level rise has amplified the need to understand Greenland's hydrology and melt patterns. Drainage basins for Greenland's land surface and ice sheet were produced using the GLAS/IceSat 1km surface DEM and a hydrostatic surface pressure grid over the ice sheet. The pressure grid was modeled using the surface DEM and a 5km bedrock elevation grid (Bamber et al., 2001), assuming hydrostatic pressure and no conduit flow within the ice sheet as per Lewis & Smith (2009). Pour points were generated using an 8-pixel pour point derivation algorithm (Jenson & Domingue, 1988) and were used to model watersheds and flow networks. This work provides a complete watershed, flow and drainage network dataset for the entirety of Greenland - both land and ice surface regions. Potential applications include ice sheet melt water routing to the ocean, supraglacial melt water patterns, and the separation of specific ice melt drainage networks from snow melt networks. These basins act as a base for the incorporation of finer resolution IceBridge and GLAS/IceSat data products.

Pitcher, L. H.; Smith, L. C.; Chu, V. W.; Wang, J.

2011-12-01

228

Estimating mass-wasting processes in active earth slides - earth flows with time-series of High-Resolution DEMs from photogrammetry and airborne LiDAR  

NASA Astrophysics Data System (ADS)

This paper deals with the use of time-series of High-Resolution Digital Elevation Models (HR DEMs) obtained from photogrammetry and airborne LiDAR coupled with aerial photos, to analyse the magnitude of recently reactivated large scale earth slides - earth flows located in the northern Apennines of Italy. The landslides underwent complete reactivation between 2001 and 2006, causing civil protection emergencies. With the final aim to support hazard assessment and the planning of mitigation measures, high-resolution DEMs are used to identify, quantify and visualize depletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allows to quantify mass wasting, i.e. the amount of landslide material that is wasted during reactivation events due to stream erosion along the slope and at its bottom, resulting in sediment discharge into the local fluvial system, and to assess the total volumetric magnitude of the events. By quantifying and visualising elevation changes at the slope scale, results are also a valuable support for the comprehension of geomorphological processes acting behind the evolution of the analysed landslides.

Corsini, A.; Borgatti, L.; Cervi, F.; Dahne, A.; Ronchetti, F.; Sterzai, P.

2009-03-01

229

Die neogene Hebungsgeschichte der Patagonischen Anden im Kontext der Subduktion eines aktiven Spreizungszentrums  

NASA Astrophysics Data System (ADS)

Das Phänomen der Subduktion eines aktiven Spreizungszentrums an der Südspitze Südamerikas ist seit langem bekannt. Eine Vielzahl von geologischen Beobachtungen wurden mit diesem Phänomen in Verbindung gebracht, trotzdem ist der genaue Mechanismus der Beeinflussung des aktiven Kontinentalrandes weitgehend unbekannt. Die Zusammenhänge zwischen den Subduktionsprozessen und der Entwicklung der patagonischen Anden zwischen 47°S und 48°S stehen im Mittelpunkt der Untersuchungen. Um eine detaillierte zeitliche Auflösung der zugrunde liegenden Prozesse untersuchen zu können, wurde die Entwicklung der Vorlandsedimentation, die thermische Entwicklung und die Heraushebung der Oberkruste des andinen Orogens untersucht und diese in Bezug zur Subduktion des Chile-Rückens gesetzt. Im Bereich von 47°30′S wurden die synorogenen Vorlandsedimente der Santa Cruz Formation sedimentologisch untersucht. Diese fluviatilen Sedimente wurden in einem reliefarmen Vorlandgebiet durch häufige Rinnenverlagerung und dem Aufbau von Rinnenumlagerungsgürteln in Kombination mit assoziierten groräumigen Überflutungsablagerungen akkumuliert. Sie stehen in einem engen Zusammenhang mit der orogenen Entwicklung im andinen Liefergebiet. Dies spiegelt sich in dem nach oben gröber werdenden Zyklus der Santa Cruz Formation wider. Die magnetostratigraphischen Untersuchungen einer 270 m mächtigen Sequenz aus der Basis der Santa Cruz Formation, die mit 329 Einzelproben aus 96 Probenpunkten beprobt wurde, ergab 7 Umkehrungen der geomagnetischen Feldrichtung. Mit Hilfe der geomagnetischen Polaritätszeitskala (CANDE AND KENT, 1995) konnte der untersuchte Abschnitt der Santa Cruz Formation zwischen 16.2 und 18.5 Ma datiert werden. Als Träger der Sedimentations-Remanenz konnten überwiegend Pseudoeinbereichs-Magentitpartikel und untergeordnet Hämatitpartikel identifiziert werden. An drei Profilen der Santa Cruz Formation wurden aus Sandsteinlagen unterschiedlicher stratigraphischer Position detritische Apatite mit Hilfe der thermochronologischen Spaltspurmethode untersucht. Die thermisch nicht rückgesetzten, detritischen Apatite spiegeln das Auftreten unterschiedlicher Altersdomänen im Liefergebiet der Sedimente wider. In der Kombination mit den geochemischen Gesamtgesteinsuntersuchungen der Sedimente und den petrographischen Untersuchungen der Sandsteine, die ein überwiegend andesitisch-vulkanisch geprägtes Liefergebiet widerspiegeln, kann nachgewiesen werden, dass die Erosion im Liefergebiet um 16.5 Ma in tiefere, deformierte Krustensegmente einschneidet. Dies bedeutet, dass aufgrund der Denudation im andinen Orogen erste Sockelgesteinseinheiten in den Bereich der Abtragung gelangen und dass dieser Eintrag um 12 bis 10 Ma ein Volumen einnimmt, das zu signifikanten Änderungen der Gesamtgesteinsgeochemie der Vorlandsedimente führt. Die thermochronologische Untersuchung von Apatiten aus rezenten topographischen Höhenprofilen aus der Kernzone der patagonischen Anden im Bereich von 47°30′S zeigen den Beginn einer beschleunigten Heraushebung des Orogens um 7.5 Ma. Aus diesen Untersuchungen kann eine Denudationsrate im Zeitraum der letzen 7 bis 8 Ma von 600 bis 650 m/Ma abgeschätzt werden. Die Modellierung der Apatit-Spaltspurergebnisse zeigt eine signifikante Temperaturerhöhung im Zeitraum zwischen 12 und 8 Ma um 20 bis 30°C für diesen Krustenbereich, die mit der Subduktion des aktiven Chile-Rückens in diesem Bereich der Anden in Verbindung gebracht wird. Aus den gewonnen Daten kann ein Modell für die Entwicklung der patagonischen Anden seit dem frühen Miozän abgeleitet werden. In diesem Modell wird die orogene Entwicklung in den patagonischen Anden auf eine erhöhte Konvergenzrate zwischen der Nazca Platte und der Südamerikanischen Platte zurückgeführt, die für die Heraushebung und Denudation der Anden sowie für die damit verbundene Entwicklung im Vorlandbereich verantwortlich ist. Diese orogene Entwicklung wird in einer späten Phase durch die nordwärts wandernde Subduktion des aktiven Spreizungszentrums des Chile

Warkus, Frank

2002-05-01

230

Late-stage volcano geomorphic evolution of the Pleistocene San Francisco Mountain, Arizona (USA), based on high-resolution DEM analysis and 40Ar/39Ar chronology  

NASA Astrophysics Data System (ADS)

The cone-building volcanic activity and subsequent erosion of San Francisco Mountain, AZ, USA, were studied by using high-resolution digital elevation model (DEM) analysis and new 40Ar/39Ar dating. By defining remnants or planèzes of the volcano flanks in DEM-derived images, the original edifice can be reconstructed. We propose a two-cone model with adjacent summit vents which were active in different times. The reconstructed cones were 4,460 and 4,350 m high a.s.l., corresponding to ˜2,160 and 2,050 m relative height, respectively. New 40Ar/39Ar data allow us to decipher the chronological details of the cone-building activity. We dated the Older and Younger Andesites of the volcano that, according to previous mapping, built the stage 2 and stage 3 stratocones, respectively. The new 40Ar/39Ar plateau ages yielded 589-556 ka for the Older and 514-505 ka for the Younger Andesites, supporting their distinct nature with a possible dormant period between. The obtained ages imply an intense final (?100 ka long) cone-building activity, terminating ˜100 ka earlier than indicated by previous K-Ar ages. Moreover, 40Ar/39Ar dating constrains the formation of the Inner Basin, an elliptical depression in the center of the volcano initially created by flank collapse. A 530 ka age (with a ±58.4 ka 2? error) for a post-depression dacite suggests that the collapse event is geochronologically indistinguishable from the termination of the andesitic cone-building activity. According to our DEM analysis, the original cone of San Francisco Mountain had a volume of about 80 km3. Of this volume, ˜7.5 km3 was removed by the flank collapse and subsequent glacial erosion, creating the present-day enlarged Inner Basin, and ˜2 km3 was removed from the outer valleys by erosion. Based on volumetric analysis and previous and new radiometric ages, the average long-term eruption rate of San Francisco Mountain was ˜0.2 km3/ka, which is a medium rate for long-lived stratovolcanoes. However, according to the new 40Ar/39Ar dates for the last ?100 ka period, the final stratovolcanic activity was characterized by a greater ˜0.3 km3/ka rate.

Karátson, Dávid; Telbisz, Tamás; Singer, Brad S.

2010-09-01

231

Künstler zwischen selbständiger und abhängiger Erwerbsarbeit  

Microsoft Academic Search

Artistic labour markets in Germany have been characterised by a continuous increase in the artist labour force since the 1980s. A closer examination of these job markets, however, reveals the dimensions of growth: In the cultural sector, regular employment has been withdrawn in favour of temporary employment or self-employment. The analysis in this chapter focuses on the employment development of

Carroll Haak

2005-01-01

232

Paläo-SETI zwischen Mythos und Wissenschaft  

Microsoft Academic Search

This paper is a discussion of the tension between myth and science in the field of Palaeo-SETI. It concentrates upon the works of Erich von Däniken as the founder of the recently established Ancient Astronauts Movement. Däniken's version of Ancient Astronauts is categorized as a mythical foundation of a technocratic ideology, which has its roots in the principles of the

INGBERT JÜDT

2003-01-01

233

Electrocatalytic mechanism and kinetics of SOMs oxidation on ordered PtPb and PtBi intermetallic compounds: DEMS and FTIRS study.  

PubMed

The electrocatalytic activities and mechanisms of PtPb and PtBi ordered intermetallic phases towards formic acid, formaldehyde and methanol oxidation have been studied by DEMS and FTIRS, and the results compared to those for a pure polycrystalline platinum electrode. While PtPb exhibits an enhanced electrocatalytic activity for the oxidation of all three organic molecules when compared to a Pt electrode, PtBi exhibits an enhanced catalytic activity towards formic acid and formaldehyde oxidation, but not methanol. FTIRS data indicate that adsorbed CO does not form on PtPb or PtBi intermetallic compounds during the oxidation of formic acid, formaldehyde and methanol, and therefore their oxidation on both PtPb and PtBi intermetallic compounds proceeds via a non-CO(ads) pathway. Quantitative DEMS measurements indicate that only CO(2) was detected as a final product during formic acid oxidation on Pt, PtPb and PtBi electrodes. At a smooth polycrystalline platinum electrode, the oxidation of formaldehyde and methanol produces mainly intermediates (formaldehyde and formic acid), while CO(2) is a minor product. In contrast, CO(2) is the major product for formaldehyde and methanol oxidation at a PtPb electrode. The high current efficiency of CO(2) formation for methanol and formaldehyde oxidation at a PtPb electrode can be ascribed to the complete dehydrogenation of formaldehyde and formic acid due to electronic effects. The low onset potential, high current density and high CO(2) yield make PtPb one of the most promising electrocatalysts for fuel cell applications using small organic molecules as fuels. PMID:18563235

Wang, Hongsen; Alden, Laif; Disalvo, F J; Abruña, Héctor D

2008-04-21

234

A visual basic program for ridge axis picking on DEM data using the profile-recognition and polygon-breaking algorithm  

NASA Astrophysics Data System (ADS)

For many scientists working with digital topographic data, extracting lineaments or linear features is an important step in structuring and analyzing raw data. A ridge axis, which represents the top a mountain ridge, is one of the most important topographic features used in a wide variety of applications. Algorithms and software for automating the extraction of ridges or ridge axes from DEMs are, however, still not easily available or not widely acceptable. In this paper, we present a user-friendly Visual Basic program that automates the extraction of the ridge axis system from DEM data, based on the profile-recognition and polygon-breaking algorithm (PPA). An important feature of PPA is that it takes a global approach, as opposed to the local neighborhood operators used in many other algorithms. Each segment detected by PPA considers not only relations with contiguous neighboring grid points, but also strives to preserve the continuity of the global trend. This is an attempt to simulate human operators, who always factor in the overall trend of the lineament before delineating its local parts. PPA starts by connecting all points in a neighborhood that can possibly lie on the ridge axis, thus forming a belt of polygons in the first step. Next, a polygon breaking process eliminates unwanted segments according to the assumption that a ridge segment cannot be the side of any closed polygon, and that the result should be a purely dendritic line pattern. Finally, a branch-reduction process is executed to eliminate all parallel false ridges that remained due to the conservative approach taken in the first step. Results indicate that PPA is reasonably successful in picking out ridges that would have been identified manually by experts. In addition to providing a detailed user interface for executing PPA, several modifications were made to significantly improve the computational efficiency of PPA, as compared to the original version published in 1998. The source codes are provided for free download on the website listed above.

Chang, Yet-Chung; Sinha, Gaurav

2007-02-01

235

Multi-frequency study of supernova remnants in the Large Magellanic Cloud. Confirmation of the supernova remnant status of DEM L205  

NASA Astrophysics Data System (ADS)

Context. The Large Magellanic Cloud (LMC) is an ideal target for the study of an unbiased and complete sample of supernova remnants (SNRs). We started an X-ray survey of the LMC with XMM-Newton, which, in combination with observations at other wavelengths, will allow us to discover and study remnants that are either even fainter or more evolved (or both) than previously known. Aims: We present new X-ray and radio data of the LMC SNR candidate DEM L205, obtained by XMM-Newton and ATCA, along with archival optical and infrared observations. Methods: We use data at various wavelengths to study this object and its complex neighbourhood, in particular in the context of the star formation activity, past and present, around the source. We analyse the X-ray spectrum to derive some remnant's properties, such as age and explosion energy. Results: Supernova remnant features are detected at all observed wavelengths : soft and extended X-ray emission is observed, arising from a thermal plasma with a temperature kT between 0.2 keV and 0.3 keV. Optical line emission is characterised by an enhanced [S ii]-to-H? ratio and a shell-like morphology, correlating with the X-ray emission. The source is not or only tentatively detected at near-infrared wavelengths (shorter than 10 ?m), but there is a detection of arc-like emission at mid and far-infrared wavelengths (24 and 70 ?m) that can be unambiguously associated with the remnant. We suggest that thermal emission from dust heated by stellar radiation and shock waves is the main contributor to the infrared emission. Finally, an extended and faint non-thermal radio emission correlates with the remnant at other wavelengths and we find a radio spectral index between -0.7 and -0.9, within the range for SNRs. The size of the remnant is ~79 × 64 pc and we estimate a dynamical age of about 35 000 years. Conclusions: We definitely confirm DEM L205 as a new SNR. This object ranks amongst the largest remnants known in the LMC. The numerous massive stars and the recent outburst in star formation around the source strongly suggest that a core-collapse supernova is the progenitor of this remnant. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

Maggi, P.; Haberl, F.; Bozzetto, L. M.; Filipovi?, M. D.; Points, S. D.; Chu, Y.-H.; Sasaki, M.; Pietsch, W.; Gruendl, R. A.; Dickel, J.; Smith, R. C.; Sturm, R.; Crawford, E. J.; De Horta, A. Y.

2012-10-01

236

Assessment of the evolutionary dynamics of stream controlled hillslopes in the high mountains of Taiwan by analysis of multitemporal DEMs based on high accuracy survey data  

NASA Astrophysics Data System (ADS)

The high mountains of Taiwan belong to the earth's most dynamic landscapes. Landslides and debris flows frequently occur due to high rates of tectonic uplift, earthquakes and violent weather conditions including typhoons. In the Tachia catchment numerous translational landslides occur frequently as a result of seismic events and typhoons. The reaction of landslide activity to earthquakes and typhoon rainfall is complex and therefore hard to predict (Lin et al. 2006). This study focuses on the evolution of a selection of stream controlled and highly active slopes within the time period of two years. From April 2008 until November 2009 a repeated surveying of active slopes on a half year basis is done to acquire high accuracy point data for DEM generation. The results presented here are based on measurements from April and November 2008. The choice of the interpolation method and cell size for the DEM generation in respect to slope characteristics and the specific needs in analysis of a multitemporal dataset turned out to be the most critical problem to be assessed. The accuracy of the interpolation method is relevant for both, the quantitative and the qualitative analysis of the acquired survey data. A comparison of the first two datasets revealed a significant noise in the survey data due to the fact that the survey of the almost inaccessible slopes is done manually by reflectorless laser distance measurements over large distances. Adding up to the error caused by the noise of the survey data is the error caused by the chosen interpolation method. A first estimation of the resulting overall error and its influence on the comparative analysis of the datasets was done. It reveals that the observed changes are within the error margins in case of the minor active slopes. In contrast, it turned out that the change on highly active slopes can be quantified using the applied method. Based on the results of the first qualitative analysis the valley floors seem to have widened considerably in parts of the study area during the last period of typhoon activity in summer 2008. Only a comparision with the measurements to be done in 2009 will show weather the widening of the valley floors under current conditions turns out to be a general trend. References Chapelot, V., Darboux, F., Bourennane, H., Leguédois, S., Silvera, N. & Phachomphon, K. (2006): Accuracy of interpolation techniques from the derivation of digital elevation models in relation to landform types and data density. - Geomorphology 77, 126-141 Lin, J.-C., Petley, D., Jen, C.-H., Koh, A. & Hsu, M.-L. (2006): Slope movements in a dynamic environment - A case study of Tachia River, Central Taiwan. - Quaternary International 147 (1), 103-112

Wenske, D.; Jen, C.-H.; Böse, M.; Lin, J.-C.

2009-04-01

237

Kontrazeption und Schwangerschaft bei Frauen mit Epilepsie Eine Stellungnahme der Deutschen Gesellschaft für Gynäkologische Endokrinologie und Fortpflanzungsmedizin  

Microsoft Academic Search

Epilepsien gehören zu den häufigsten neurologischen Erkrankungen. Für Frauen, die unter einer Epilepsie leiden, ist eine enge Zusammenarbeit zwischen dem betreuenden Neurologen und Gynäkologen unerlässlich, da sowohl die Epilepsie an sich aber auch die antiepileptische Medikation viele Bereiche des Lebens der betroffenen Frauen negativ beeinflussen kann: so können Fertilität und reproduktive Funktionen eingeschränkt sein, aber auch die bidirektionalen Interaktionen zwischen

A. Schwenkhagen; S. R. G. Stodieck; T. Rabe

2010-01-01

238

DemTect, PANDA, EASY, and MUSIC: cognitive screening tools with age correction and weighting of subtests according to their sensitivity and specificity.  

PubMed

Many cognitive screening instruments have been developed during the last decades to detect mild cognitive dysfunction and dementia, and there is an ongoing discussion as to which tool should be used in which setting and which challenges have to be considered. Among other aspects, dependence on age is a recognized problem in screening tools which still has not found its way into common scoring procedures. Another aspect which has been handled very heterogeneously is which domain is represented in which proportion in the total score. Furthermore, screening ethnic minority patients has been identified as an important but so far widely unresolved matter. In this review, four cognitive screening tools that all follow a common, stringent concept and pay regard to some critical aspects are described: the DemTect, a "generic" tool; the PANDA for Parkinson's disease patients; the EASY, a non-verbal, culture-fair screening test for patients with migration background; and the MUSIC for patients with multiple sclerosis. All of these screening instruments have an age-correction, provide a total score in which the different subtests are weighted according to their individual sensitivity and specificity, and include tasks that are specifically aligned to the cognitive profile of the target group, including the EASY with non-verbal, culture-fair tasks to overcome language and cultural barriers. The development, main characteristics, data, and limitations of these tools are presented and discussed against the background of the current landscape of cognitive screening tools. PMID:23313929

Kalbe, Elke; Calabrese, Pasquale; Fengler, Sophie; Kessler, Josef

2013-01-01

239

Scale-dependency of stream gradients derived from LiDAR DEM and its relationship to watershed morphology in the Southern Japanese Alps  

NASA Astrophysics Data System (ADS)

Bedrock erosion in streams is a key element in determining topography of mountain watershed. Failures in steep slopes can often be controlled by riverbed incision with regard to base level changes, where knickzone propagation often has a significant impact on such stream incision. Here we analyze longitudinal morphology of bedrock rivers in a steep mountain watershed in terms of stream gradient, using a high-resolution (1 m) LiDAR DEM in a steep mountain watershed at Ikawa, central Japan. By computing stream gradients with different measure lengths, scale-dependent changes in the gradient are revealed. Relative steepness of riverbed is then quantified using the scaling gradients. Spatial distribution of relative steepness in the watershed indicates that longitudinal riverbed morphology often correspond to morphological condition of slopes with differing types of channel head. Streams in subwatersheds with gentle slopes have less steepness while those in subwatersheds with steep slopes in which failures are frequent. These differences are not likely derived from lithological or tectonic factors, but from geomorphic history in the watershed. The steepness index can also be used for detection of knickzones comprising small knickpoints and waterfalls, whereas location of knickzones has rarely been identified quantitatively in such an uppermost steep mountainous watersheds. The distribution of relative steepness and knickzones possibly reflect incision waves occurring in the watershed: late- or post-glacial base level lowering could have caused formation of knickzones, and some of the propagating knickzones reached upper portions in the watershed while the uppermost area seems to be preserved.

Hayakawa, Y. S.; Imaizumi, F.; Hattanji, T.

2008-12-01

240

Investigating the definition of flood maps using a 2D hydraulic routing model forced by a DEM-based fully continuous rainfall-runoff algorithm  

NASA Astrophysics Data System (ADS)

Ongoing efforts of remote sensing technologies to provide more accurate digital elevation models (DEMs) at the global scale are supporting the use of terrain analysis and hydrologic and hydraulic modelling algorithms for flood mapping in ungauged basins. In this work we implement a fully continuous hydrologic-hydraulic model feeded by a rainfall synthetic time series for providing river hydrographs that are routed along the channel using a bidimensional hydraulic model for the detailed physically-based characterization of the inundation process. In this way the whole physical process is represented, from the net rainfall to the flow time series, avoiding any conceptual sub-method (design hyetograph and hydrograph) commonly needed to apply standard flood modelling and mapping procedures. Nevertheless, the floodplain information is no longer deterministic as the result of the evaluation of the impact on the river valley of a single design hydrologic scenario (event-based approach,EBA), but the final result is composed of a combination of data derived by the application of a fully-continuous approach (FCA). Indeed FCA provides a flow depth time series for each single cell of the inundated domain. The final flood map should be, thus, the result of a proper analysis of this dataset in statistical, qualitative and quantitative terms. Otherwise this would lead to an undefined flooding scenario that could be useless for flood risk management and decision making in urban plans.

Nardi, Fernando; Petroselli, Andrea; Grimaldi, Salvatore

2013-04-01

241

Turnen und Turnphilologie des 19. Jahrhunderts als Vorläufer moderner Sportwissenschaft  

Microsoft Academic Search

\\u000a Zusammenfassungen  Die Grundlagen der modernen Sportwissenschaft in Deutschland wurden im Rahmen der Turnbewegung, besonders in der zweiten Hälfte\\u000a des 19. Jh.s, geschaffen. Körperliche Übungen und Spiele unter dem Namen „Turnen“ entwickelten sich damals zur spezifischen\\u000a Körperkultur der Deutschen im Zusammenhang mit dem Prozess der kulturellen Nationsbildung. Die Institutionalisierung des Turnens\\u000a in Schule und Verein als einer systematischen Form der Leibesübungen forderte

Michael Krüger

2000-01-01

242

Anti-nuclear liberals and the bomb: A comparative history of Kampf dem Atomtod and the Committee for a Sane Nuclear Policy, 1957-1963  

SciTech Connect

The premises of Kampf dem Atomtod (KdA) and Citizens for a Sane Nuclear Policy (SANE) were based on nineteenth century traditions of liberal peace advocacy. Both groups gained substantial public support for their goals to prevent the nuclear armament of the Bundeswehr and to stop nuclear testing. Both organizations won well-educated middle-class and mostly white supporter. The dissertation examines the role of women: whether housewife or doctor, women stressed their special concerns as mothers. Both KdA and SANE had troubled relations with the labor movement. Their leaders hoped to gain government leaders' respect by winning a respectable, non-Communist constituency and claiming their goals were reasonable ones. Government officials attacked KdA and SANE as dupes of Moscow. Many supporters left the organizations because of their strict anti-Communism. Local groups accused their leaders of lacking initative. KdA and SANE's leaders wasted time and energy rehashing issues and postponing decisions. After a period of providing initiatives and ideas local committees disintegrated. Both organizations considered education their paramount goal but their arguments primarily reached the converted, who often preferred more political action. KdA and SANE's leaders instead chose to support respectable projects based on humanitarian ideals. Since these projects offered little in the way of concrete action agendas, supporters defected to more active organizations or slipped into apathy. Neither organization achieved its national goals. Both governments generally denied them access to the policymaking process, ignored them as irrelavant, or attacked them as Communist sympathizers. While SANE and KdA were heard by those concerned by nuclear policy, and while members of SANE's National Board did help muster support for the Partial Test Ban Treaty, both organizations failed to make liberal peace values productive in the nuclear decisionmaking process.

Thiede, B.

1992-01-01

243

Failure and frictional sliding envelopes in three-dimensional stress space: Insights from Distinct Element Method (DEM) models and implications for the brittle-ductile transition of rock  

NASA Astrophysics Data System (ADS)

Rocks deformed at low confining pressure are brittle, meaning that after peak stress the strength decreases to a residual value determined by frictional sliding. The difference between the peak and residual value is the stress drop. At high confining pressure, however, no stress drop occurs. The transition pressure at which no loss in strength occurs is a possible definition of the brittle-ductile transition. The Distinct Element Method (DEM) is used to illustrate how this type of brittle-ductile transition emerges from a simple model in which rock is idealised as an assemblage of cemented spherical unbreakable grains. These bonded particle models are subjected to loading under constant mean stress and stress ratio conditions using distortional periodic space, which eliminates possible boundary effects arising from the usage of rigid loading platens. Systematic variation of both mean stress and stress ratio allowed determination of the complete three dimensional yield, peak stress and residual strength envelopes. The models suggest that the brittle-ductile transition is a mean stress and stress ratio dependent space curve, which cannot be adequately described by commonly used failure criteria (e.g., Mohr-Coulomb, Drucker-Prager). The model peak strength data exhibit an intermediate principal stress dependency which is, at least qualitatively, similar to that observed for natural rocks deformed under polyaxial laboratory conditions. Comparison of failure envelopes determined for bonded particle models with and without bond shear failure suggests that the non-linear pressure dependence of strength (concave failure envelopes) is, at high mean stress, the result of microscopic shear failure, a result consistent with earlier two-dimensional numerical multiple-crack simulations [D. A. Lockner & T. R. Madden, JGR, Vol. 96, No. B12, 1991]. Our results may have implications for a wide range of geophysical research areas, including the strength of the crust, the seismogenic zone and slip-tendency analysis.

Schöpfer, Martin; Childs, Conrad; Manzocchi, Tom

2013-04-01

244

Nonlinear Force-Free Magnetic Fields of Active Regions based on automated loop tracing in AIA/SDO images with DEM discrimination of chromospheric and coronal features  

NASA Astrophysics Data System (ADS)

We developed a forward-fitting code that computes a nonlinear force-free magnetic field (NLFFF) solution constrained by line-of-sight magnetograms from HMI/SDO and by coronal loop structures detected in EUV images from AIA/SDO. The 2D coordinates of coronal loop structures are detected with an improved version of the Oriented Coronal CUrved Loop Tracing (OCCULT-2) code, an automated pattern recognition algorithm that has demonstrated a quality and fidelity in loop tracing that matches visual perception. One fundamental limitation in the completeness of detecting coronal loops comes from the background confusion of coronal loop EUV emission with low-temperature (T=10^4-10^6 K) emission from the chromosphere and transition region, as well as T ~ 1.0 MK emission from reticulated ``moss structure'' that stems from the footpoints of hotter (T 2-8 MK) coronal loops. We employ a pixel-wise differential emission measure (DEM) analysis using the 7 coronal AIA filters in order to produce uncontaminated emission measure maps in coronal temperature ranges, which allows an improved performance of automated loop tracing. A nonlinear force-free magnetic field solution is then computed by forward-fitting of an analytical NLFFF solution of twisted coronal field lines to the automatically traced coronal loop coordinates. We demonstrate the performance of this magnetic field modeling for a number of solar active regions observed with SDO. The developed method is able to calculate the most realistic magnetic field models of solar active regions that match all available observable constraints.

Aschwanden, Markus J.; Boerner, P.; AIA/SDO Team

2013-07-01

245

Empfänglichkeit von Feldhasen ( Lepus europaeus Pall.) für die infektiöse hämorrhagische Erkrankung der Kaninchen (RVHD) unter experimentellen Bedingungen  

Microsoft Academic Search

Der Export von Hasen nach Frankreich und Italien hat für die Jagdverbände der CSFR große wirtschaftliche Bedeutung. Im Zusammenhang mit dem Vorkommen der RVHD bei Kaninchen in der CSFR waren die Anforderungen für den Import der Feldhasen verschärft worden, was den Export wesentlich erschwerte. Ziel unseres Experimentes war, die Empfänglichkeit des Hasen auf RVHD und die Möglichkeit der aktiven Übertragung

R. Jur?ík; L. Len?uchová; J. Salaj; J. Slame?ka; I. Melichárek; D. Révayová

1992-01-01

246

Weltkonjunktur und deutsche Konjunktur im Winter 2011  

Microsoft Academic Search

Die Erholung der Weltkonjunktur ist im Jahr 2011 ins Stocken geraten. Zur Jahreswende steht die Weltwirtschaft unter dem Eindruck der Staatsschuldenkrise im Euroraum, Unsicherheiten über den Zustand des Finanzsektors, Unwägbarkeiten im Zusammenhang mit der finanzpolitischen Diskussion in den Vereinigten Staaten und einer überraschend schwachen Dynamik in den Schwellenländern. Für die Prognose ist angenommen, dass es noch einige Monate dauert, bis

Jens Boysen-Hogrefe; Klaus-Jürgen Gern; Nils Jannsen; Martin Plödt; Björn Van Roye; Joachim Scheide; Tim Schwarzmüller; Dominik Groll; Stefan Kooths

2011-01-01

247

Über die Eigenschaften der durchdringenden Korpuskularstrahlung im Meeresniveau  

Microsoft Academic Search

Zusammenfassung Die Absorbierbarkeit der durchdringenden Korpuskularstrahlung wurde bis zu einer Absorberdicke von 101 cm Blei untersucht; die Versuchsresultate werden im Zusammenhang mit der Frage nach dem Wesen der Ultrastrahlung und nach ihrer Energie diskutiert. — Das Entstehen einer Sekundärstrahlung in der von den Ultrakorpuskularstrahlen durchsetzten Materie wurde nachgewiesen. Die wichtigsten Eigentümlichkeiten dieser Erscheinung und der Einfluß der Sekundärstrahlung auf die

Bruno Rossi

1933-01-01

248

Aufgabenbereiche der Medienbildung im Informatikunterricht  

Microsoft Academic Search

Der Zusammenhang von Informatischer Bildung und Medienbildung wird seit einiger Zeit, meist vor dem Hintergrund der Informatischen Grundbil- dung ((Wi00), S.39ff), diskutiert. Daneben gibt es eine Diskussion um den Charak- ter des Informatikunterrichts 1 , in der ebenfalls medienbildende Aspekte im Infor- matikunterricht angesprochen werden. Obwohl informatische Bezüge im Vordergrund stehen, werden insgesamt recht verschiedene Aufgabenbereiche ge- nannt. Diese haben

Carsten Schulte; Olaf Scheel

2001-01-01

249

Über lichtelektrische Wirkung in Steinsalzkristallen  

Microsoft Academic Search

Zusammenfassung 1.Es werden nach Röntgens Vorgang „lichtelektrische Ströme“ in natürlich und künstlich verfärbtem Steinsalz gemessen. Dabei werden die gleichen Bedingungen benutzt, unter denen sich bei den lichtelektrisch leitenden Kristallen vom Brechungsindex höher als 2 die einfachen Erscheinungen des lichtelektrischen Primärstromes ergeben. Es ergibt sich:a)Reproduzierbarkeit der Messungen selbst nach Wochen.b)linearer Zusammenhang zwischen Strom und Spannung, keine Andeutung von Sättigung auch bei

J. Bingel

1924-01-01

250

Die Wirkung von Work-Life Balance Initiativen auf das Mitarbeitercommitment: Eine empirische Untersuchung in der Unternehmensberatungsbranche (The Impact of Corporate Work-life Balance Initiatives on Employee Commitment: An Empirical Investigation in the German Consultancy Sector)  

Microsoft Academic Search

Der vorliegende Beitrag untersucht die Wirkung von unternehmerischen Work-Life Balance Initiativen fuer die emotionale Bindung der Mitarbeiter zum Unternehmen, d. h. das organisationale Commitment von Mitarbeitern im Kontext der Unternehmensberatung. Dazu wurde eine Untersuchung mit insgesamt 275 Unternehmensberaterinnen und -beratern durchgefuehrt. Die Datenanalyse erfolgte anhand eines PLS-Strukturgleichungsmodells (Partial-Least-Squares-Ansatz). Die Ergebnisse weisen darauf hin, dass auch in Beratungsorganisationen ein Zusammenhang zwischen

Stephan Kaiser; Max Ringlstetter; Cornelia U. Reindl; Martin L. Stolz

2010-01-01

251

Beiträge zur Physiologie schwerer körperlicher Arbeit  

Microsoft Academic Search

Zusammenfassung  Es wurden Versuche ausgeführt, um den Zusammenhang zwischen Körpertemperatur und Stoffwechsel bei Menschen zu untersuchen. Es wurden 21 Versuche an 4 männlichen Vpn. ausgeführt.Durch Diathermie wurde eine Erhöhung der Körpertemperatur um etwa 2° C erreicht.Die Versuche zeigen, daß der Standardstoffwechsel um 10,8% erhöht wird, wenn die Körpertemperatur um 1 ° C ansteigt. Ein geringer Teil dieser Steigerung wird der vermehrten

E. Hohwii Christensen

1933-01-01

252

Citric acid inhibits growth of Helicobacter pylori in vitro : a new strategy for eradication  

Microsoft Academic Search

\\u000a Zusammenfassung  HINTERGRUND: Infektionen mit Helicobacter pylori stellen ein weltweites gesundheitliches Problem dar. Der Zusammenhang zwischen peptischer Ulkuskrankheit und Helicobacter pylori Infektionen ist gut dokumentiert. Demgemäß ist eine Eradikation obligatorisch, jedoch sind die hohen Kosten der multimedikamentösen\\u000a Therapie sowie die Resistenz von Helicobacter pylori gegen Antibiotika limitierende Faktoren. METHODEN: Die wachstumshemmende Wirkung von 3 % Wasserstoffperoxid, 8,4 % Natriumbicarbonat,\\u000a 2 % Ascorbinsäure,

Jan Zazgornik; Helmut Mittermayer

2011-01-01

253

Pit Craters and Collapse Calderas: Structural Influences of Initial Mechanical and Geometric Properties as revealed by 2D Distinct Element Method (DEM) Models  

NASA Astrophysics Data System (ADS)

Pit craters and collapse calderas are volcanic depressions produced by subsidence of the roof of a magma reservoir. They are near-ubiquitous features of volcanic fields or edifices on Earth and other terrestrial planets. Pit crater and caldera subsidence may occur by diverse structural mechanisms, each previously linked with various initial controlling factors. We present Distinct Element Method (DEM) numerical models of this subsidence process to shed new light on such mechanisms and the factors controlling them. Our models comprise an assemblage of gravitationally-loaded circular particles that interact at their contacts according to elastic-frictional laws. Cohesion is provided by inter-particle bonds that break once their shear or tensile strength is exceeded. Varying particle and bond micro-properties yielded assemblage macro-properties and rheological responses characteristic of natural rock masses (e.g. elasticity, failure, and strain softening), with fracture localization simulated by bond breakage. The magma reservoir is represented as a region of non-bonded, low-friction particles. Withdrawal of magma is simulated by incrementally reducing the area of the reservoir particles. The resultant gravity-driven failure and subsidence of the overlying reservoir roof is explicitly replicated. We have investigated the effect on subsidence of initial mechanical and geometric properties. The former included Young’s Modulus and strength (cohesion), whilst the latter included the thickness/diameter ratio (T/D) of the roof and the ceiling curvature imparted by the shape of the underlying reservoir. These initial mechanical and geometric properties interacted to produce several ‘end-member’ subsidence mechanisms: (1) Predominantly central sagging at low strength and low T/D; (2) predominantly single central block subsidence at low to intermediate strength and at intermediate T/D; (3) multiple central block subsidence at high strength and high T/D; (4) a hitherto unrecognized ‘central snapping’ mechanism at high strength, low T/D, and with a low ceiling curvature. In terms of material properties, the occurrence of these mechanisms was weakly dependent on Young’s Modulus, but strongly dependent on material strength. In terms of geometric properties, a moderate dependency on reservoir shape at low T/D diminished at intermediate and high T/D. One important outcome of the interaction of mechanical and geometric properties is that the critical T/D ratio, above which the single central block mechanism changes to the multiple central block mechanism, decreases from > 1 to < 0.6 with increasing material strength. Our model results agree well with those of analogue studies of pit crater and caldera subsidence, and provide a more quantitative understanding of the genesis of different mechanisms observed in the field - e.g. at Nindiri crater, Nicaragua and Miyakejima caldera, Japan.

Holohan, E. P.; Schöpfer, M. P.; Walsh, J. J.

2009-12-01

254

Kanban - der Weg ist das Ziel  

NASA Astrophysics Data System (ADS)

Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

255

VERORDNUNG (EG) Nr. 742\\/2003 DER KOMMISSION vom 28. April 2003 zur siebzehnten Änderung der Verordnung (EG) Nr. 881\\/2002 des Rates über die Anwendung bestimmter spezifischer restriktiver Maßnahmen gegen bestimmte Personen und Organisationen, die mit Osama bin Laden, dem Al-Qaida-Netzwerk und den Taliban in Verbindung stehen, und zur Aufhebung der Verordnung (EG) Nr. 467\\/2001 des Rates  

Microsoft Academic Search

DIE KOMMISSION DER EUROPÄISCHEN GEMEINSCHAFTEN — gestützt auf den Vertrag zur Gründung der Europäischen Gemeinschaft, gestützt auf die Verordnung (EG) Nr. 881\\/2002 des Rates vom 27. Mai 2002 über die Anwendung bestimmter spezifischer restriktiver Maßnahmen gegen bestimmte Personen und Orga- nisationen, die mit Osama bin Laden, dem Al-Qaida-Netzwerk und den Taliban in Verbindung stehen, und zur Aufhebung der Verordnung (EG)

Christopher PATTEN

2003-01-01

256

Politiker-Homepages zwischen Politik-PR und Bürgerpartizipation  

Microsoft Academic Search

Zusammenfassungen  Gut die Hälfte der Bundespolitiker und knapp ein Drittel der Landespolitiker betreiben im Jahr 2002 eine eigene Website, auf\\u000a der sie ihre politische Arbeit und ihre Person darstellen sowie den Bürgern Interaktionsmöglichkeiten bieten (z. B. elektronisches\\u000a Gästebuch, Online-Forum, E-Mail-Adresse). Die Politiker-Homepage als neues politisches Online-Format ist Gegenstand der kritischen\\u000a Berichterstattung in den Massenmedien und wird von etwa einem Viertel der

Nicola Döring

2003-01-01

257

Bewegungstherapie zwischen 1900 und 2000 – Momentaufnahmen einer Entwicklung  

Microsoft Academic Search

\\u000a Bewegung wurde als „Heilmittel“ im 19. Jhd. wiederentdeckt. Die „schwedische Heilgymnastik” eroberte auch Deutschland, wo\\u000a 1900 die erste Lehranstalt für Heilgymnastik in Kiel gegründet wurde. Gekennzeichnet war diese Heilgymnastik durch schablonenhaft\\u000a vorgegebene Bewegungsformen, meist mit apparativer Unterstützung (ZANDER-Apparate). Dauerdehnungen mit Zügen und Gewichten\\u000a (Redression) und das Üben einzelner Gelenke und Muskeln standen im Vordergrund. Daran änderte sich bis in die

A. Hüter-Becker

258

Zwischen Theorie und Deutung der Vererbung psychischer Störungen  

Microsoft Academic Search

  Between Theory and Interpretation of the Hereditary Transmission Process of Mental Disease. The Introduction of Mendelism\\u000a in German and North American Psychiatry, 1911–1930\\u000a \\u000a 1911 saw the beginning of decisive developments in psychiatric genetic research. During that year, two expert papers dealing\\u000a with the application of the Mendelian Theory were published in Germany and in the United States. Only a decade

Anne Cottebrune

2009-01-01

259

Untersuchungen zur genetischen Transformation zwischen Agrobacterium tumefaciens und Rhizobium spec  

Microsoft Academic Search

Mit DNA von virulenten Agrobacterium tumefaciens-Stämmen gelingt die Übertragung der Fähigkeit zur Induktion pflanzlicher Tumoren auf einige Rhizobium-Stämme. Unter Berücksichtigung kritischer Fehlerquellen machen die beschriebenen Untersuchungen das Vorliegen einer echten genetischen Transformation sehr wahrscheinlich.

Hartmut Kern

1965-01-01

260

Zivilgesellschaft – zwischen Wirtschaft und Staat. Eine institutionenoekonomische Interpretation  

Microsoft Academic Search

›Civil society‹ seems like a new myth, but to explain it we need an institu- tional design, developed by Buchanan, Dixit and Barzel: third party enforce- ment (TPE). Traditionally TPE means the role of the state as a regulator or mediator of all transactional parties on the marketplace. In the context of the civil society TPE demonstrates the non-governmental role

Birger P. Priddat

2004-01-01

261

Modelle für Reaktionen zwischen organischen und mineralischen Substanzen im Boden  

Microsoft Academic Search

Summary Low molecular siloxanes, silicagel, aluminium oxide, permutite, and perlite were dissolved by ammoniacal catechol solution. Silicagel was also dissolved by othero-diphenols. Low molecular silicon organic ester or complex compounds were crystallised from the reaction products of silicagel with catechol and 2,3-naphthalenediol. On orthoclase an insoluble brown cover was formed. The reaction ofo-diphenols with silicates may be important in soil

R. Hess; R. Bach; H. Deuel

1960-01-01

262

Über die Geruchsspur von Lasius fuliginosus zwischen Nest und Futterquelle  

Microsoft Academic Search

Summary In this study it was found that the chemical trail laid by workers of the ant speciesLasius fuliginosus between their nest and a food source, is always laid in the direction food to nest. It was also found that this trail can be artificially created by dissolving the contents of the ant's hind-gut or stomach in water, and then

W. Hangartner; St. Bernstein

1964-01-01

263

Paläobiogeographie jurassischer Muschelfaunen: Beziehung zwischen Süd- und Nordrand der Tethys  

Microsoft Academic Search

\\u000a Abstract  Similarities of mid-Jurassic bivalve faunas between the European and the Ethiopian faunal province are very high at the genus-level.\\u000a At the species-level, however, it is shown that during the Bathonian and Callovian 35% of the bivalves occurring in the Ethiopian\\u000a faunal province are restricted to this province. In the region of Kachchh (W-India) in the same time-interval 25% of all

Michael Heinze

1996-01-01

264

Die Enthüllungsplattform WikiLeaks zwischen Bürgerservice und Sicherheitsrisiko  

Microsoft Academic Search

\\u000a Im Laufe der Zeit wurde vor allem von politischer Seite immer wieder gefordert, das Internet dürfe kein „rechtsfreier Raum“\\u000a sein. Dieser Warnung liegt der Eindruck zugrunde, dass das Netz unrechtmäßiges Verhalten nicht nur begünstige, sondern in\\u000a einigen Fällen sogar erst ermögliche – man denke zum Beispiel an internetspezifische Delikte wie das Phishing.

Pascal Riemann

265

Analyse arztstrafrechtlicher Ermittlungsverfahren der Staatsanwaltschaft Aachen zwischen 1978 und 1981  

Microsoft Academic Search

Altogether, 318 preliminary proceedings were initiated against physicians, compared to 2 against nonmedical practitioners. The majority i.e., 192 proceedings, dealt with charges of torture and deprivation of freedom committed against patients under psychiatric treatment. Ninety-nine proceedings were based on negligent bodily injury and negligent homicide and 15 on failure to give medical assistance. Other reasons were given in isolated cases

H. Althoff; Th. Solbach

1984-01-01

266

Die Amtliche Sammlung von Untersuchungsverfahren nach § 64 LFGB, § 35 Vorläufiges Tabakgesetz und § 28b Gentechnikgesetz - ein Instrument der amtlichen Lebensmittelüberwachung  

NASA Astrophysics Data System (ADS)

Immer wieder werden Skandale in Zusammenhang mit Lebensmitteln bekannt. Schlagworte wie BSE, Gammelfleisch, Acrylamid, Cumarin oder auch Melamin, Dioxin sind den Verbrauchern geläufig und erschüttern das Vertrauen in ein gesundes und ernährungsphysiologisch wertvolles Lebensmittel. Das Bewusstsein des Verbrauchers hinsichtlich der Ernährung und der Auswahl beim Kauf der Lebensmittel hat sich in den vergangenen Jahren deutlich verändert. Bei der Auswahl seiner Lebensmittel liegt sein Augenmerk verstärkt auf gesunden, qualitativ hochwertigen und vor allem sicheren Lebensmitteln. Dies wurde insbesondere bei dem verhaltenen Kauf von Fleisch und Fleischerzeugnissen während der BSE-Krise oder auch dem kürzlich aufgetretenen Gammelfleischskandal deutlich.

Renger, Silke; Stachel, Carolin

267

Krankheitsursachen Gene: neue Genetik und public health  

Microsoft Academic Search

Nach dem zweiten Weltkrieg war es um die medizinische Genetik nach den Erfahrungen mit der Verbindung zwischen Genetik und eugenischer Bewegung erst einmal still geworden. In der Folgezeit kam es zu enormen Fortschritten auf dem Gebiet der Molekularbiologie. Mei-lensteine waren die Entdeckung der Doppelhelixstruktur der DNA 1953 und die Entschlüsse-lung des genetischen Codes Ende der 60iger Jahre. Im Jahr 1973

Nicola Wolf

2002-01-01

268

Bürokratie- und organisationstheoretische Analysen der Sicherheitspolitik: Vom 11. September zum Irakkrieg  

Microsoft Academic Search

In vielen Analysen wird das Geschehen zwischen dem 11. September 2001 und dem Irakkrieg 2003 als eine Ereigniskette interpretiert,\\u000a die vor allem eine Stunde der Exekutive war. Es sei der zum Krieg entschlossenen Administration von Präsident George W. Bush\\u000a gelungen, die öffentlichen Reaktionen auf die terroristischen Anschläge (in den USA und anderen Gesellschaften) zu nutzen,\\u000a ihre eigene Politik durchzusetzen. Daran

Thomas Jäger; Kai Oppermann

269

SDO-AIA DEM: Initial Results  

NASA Astrophysics Data System (ADS)

The Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory has state-of-the-art spatial resolution and shows the most detailed images of coronal loops ever observed. The series of coronal filters peak at different temperatures, which span the range of active regions. These features represent a significant improvement over earlier coronal imagers and make AIA ideal for multi-thermal analysis. Here we targeted a 171-A coronal loop in AR 11092 observed by AIA on 2010 August 3. Isothermal analysis using the 171-to-193 ratio gave a temperature of Log T = 6.1, similar to the results of EIT and TRACE. Differential Emission Measure analysis, however, showed that the plasma was multithermal, not isothermal, with a distribution that peaked between Log T = 6.3 and 6.4. The result from the isothermal analysis, which is the average of the true plasma distribution weighted by the instrument response functions, appears to be deceptively low. These results have potentially serious implications: EIT and TRACE results, which use the same isothermal method, show substantially smaller temperature gradients than predicted by standard models for loops in hydrodynamic equilibrium and have been used as strong evidence in support of footpoint heating models. These implications may have to be re-examined in the wake of new results from AIA.

Schmelz, Joan T.

2011-01-01

270

Ein Astrolab aus dem Jahr 1420  

Microsoft Academic Search

\\u000a Abstract  The star-positions on the rete of a European astrolabe made in 1420 and now private German property, emphasize how some medieval\\u000a European star-tables had been incorrectly copied and misunderstood. The star-coordinates and star-names on the astrolabe in\\u000a question are based on John of London's star-table (1246). The style of the star-pointers and the aequinoctial bar on the rete,\\u000a some inscriptions,

Burkhard Stautz

1997-01-01

271

Dem Bones: Forensic Resurrection of a Skeleton.  

ERIC Educational Resources Information Center

|Presents an activity for students to determine the sex and age of an individual from a collection of bones. Simulates some of the actual procedures conducted in a forensic anthropologist's lab, examining and identifying bones through a series of lab activities. (Author/ASK)|

Bruce, Alease

2001-01-01

272

Diesel Exhaust in Miners Study (DEMS)  

Cancer.gov

In March 2012, the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) completed a retrospective cohort mortality and nested case-control study of 12,315 workers at eight non-metal mining facilities to investigate risk of lung cancer in relation to quantitative measures of historical exposure to diesel exhaust, after taking into account smoking and other lung cancer risk factors

273

Gravity gradient modeling using gravity and DEM  

Microsoft Academic Search

A model of the gravity gradient tensor at aircraft altitude is developed from the combination of ground gravity anomaly data\\u000a and a digital elevation model. The gravity data are processed according to various operational solutions to the boundary-value\\u000a problem (numerical integration of Stokes’ integral, radial-basis splines, and least-squares collocation). The terrain elevation\\u000a data are used to reduce free-air anomalies to

Lizhi Zhu; Christopher Jekeli

2009-01-01

274

Zur Ursache des sprunghaften Streckenrückganges beim Feldhasen ( Lepus europaeus Pallas 1778) in den Jahren 1978 und 1979  

Microsoft Academic Search

Der Hase ist zahlenmäßig die bedeutendste Niederwildart in der Bundesrepublik Deutschland. Die Strecke bewegte sich von 1959 bis 1977 auf dem relative hohen Niveau zwischen 1,5 Millionen und 1 Million. Noch 1974 wurden über 1,3 Millionen Hasen erlegt. In den Jahren 1978 und 1979 trat dann sprunghaft ein starker Rückgang ein. Die Strecken fielen in diesen beiden Jahren jeweils um

H. Spittler

1987-01-01

275

Classification of honeys by principal component analysis on the basis of chemical and physical parameters  

Microsoft Academic Search

Zusammenfassung 18 chemische und physikalische Parameter der Nektar- und Honigtauhonige wurden bestimmt und die Ergebnisse statistisch mit Hilfe der Hauptkomponentenanalyse ausgewertet. Danach konnten die Honige in folgende Gruppen unterteilt werden: 1) Akazienhonige, 2) Rapshonige, 3) Linden-, Blüten-und Heidehonige, 4) Honigtauhonige. Zwischen dem Nektarhonig und Honigtauhonig lagen wahrscheinlich die Proben von Mischhonigen aus Blüten- und Waldtracht. Die bedeutendste erste Hauptkomponente war

Alina Krauze; Romuald I. Zalewski

1991-01-01

276

A porcine coronary stent modelof increased neointima formation in the left anterior descending coronary artery  

Microsoft Academic Search

Zusammenfassung Hintergrund Verschiedene klinische Studien haben für den R. interventrikularis anterior (RIVA) im Vergleich zum R. circumflexus und der rechten Koronararterie (RKA) eine höhere Restenoserate nach Koronarintervention gezeigt. In tierexperimentellen Untersuchungen konnte eine enge Beziehung zwischen der Stent-induzierten Gefäßverletzung und dem Ausmaß der Neointimabildung nachgewiesen werden. Das Ziel dieser Studie war es, den Einfluss des RIVA und der RKA auf

J. Hausleiter; M. Sebastian; A. N. Li; C. K. Abbey; H. Honda; R. Makkar; J. S. Whiting; N. Eigler

2002-01-01

277

L'impact des conditions financières sur la décision d'investissement  

Microsoft Academic Search

[ger] Seit etwa zehn Jahren besteht erneut ein Interesse für Studien über die Wechselwirkungen zwischen Investitions -und Finanzierungsentscheidungen der Unternehmen. Dass die Finanzierungsbedingungen eines Unternehmens dessen tatsächliches Verhalten beeinflussen, ist ein altes Thema. Mit dem Aufkommen der neuen Mikroökonomie und insbesondere des Paradigmas der Informationsprobleme wird ihm wieder zunehmend Interesse entgegengebracht. Bei theoretischen wie auch empirischen Arbeiten wurden die Wechselwirkungen

Fabienne Rosenwald

2001-01-01

278

Dual site of action of phenoxybenzamine in the cat's spleen: Blockade of ?-adrenergic receptors and inhibition of re-uptake of neurally released norepinephrine  

Microsoft Academic Search

Zusammenfassung An der isoliert durchströmten Milz der Katze wird durch Phenoxybenzamin die bei elektrischer Reizung der Milznerven im venösen Ausfluss erscheinende Noradrenalinmenge vermehrt. Es besteht keine zeitliche und quantitative Korrelation zwischen dieser Noradrenalinvermehrung und dem Ausmass der adrenergen Blockierung. Phenoxybenzamin scheint die Vermehrung des Noradrenalins im venösen Ausfluss durch eine Blockierung der Wiederaufnahme in die Speicher und nicht durch die

H. Thoenen; A. Hürlimann; W. Haefely

1964-01-01

279

DAS WETTERSTEINGEBIRGE, WIDERLAGER DER ALLOCHTHONEN INNTALDECKE, UND DIE ÖTZTALMASSE, MOTOR TERTIÄRER POSTHUMER NW-BEWEGUNGEN IM MIEMINGER GEBIRGE (NORDTIROL, ÖSTERREICH)  

Microsoft Academic Search

Zusammenfassung: Eigene tektonische, litho- und biostratigraphische Arbeiten zwischen Garmisch-Partenkirchen und dem Inntal haben zu- sammen mit den modernen Kenntnissen zur Diagenese und Anchimetamorphose der Arbeitsgruppe KRUMM (Universi- tät Frankfurt am Main) zu einem neuen tektogenetischen Modell beigetragen. Hierbei spielt die frühe Heraushebung des Wettersteinmassives die entscheidende Rolle, da sie schon in der Kreide die Digitation der Inntaldecke verursachte und im

Rafael Ferreiro Mählmann; Jürgen Morlok

280

Embodiment und Depression  

Microsoft Academic Search

pTheoretischer Hintergrund: Embodiment Theorien postulieren eine enge reziproke Wechselwirkung zwischen dem motorischen System und emotionalen Prozessen. In einer Serie von mehreren Studien wurde untersucht, ob sich (1) Unterschiede in den Gangmustern von akut und niemals depressiven Personen zeigen; (2) ob sich solche Gangcharakteristika auch bei nicht-depressiven Personen nach Induktion von trauriger Stimmung zeigen; (3) ob sich auch bei ehemals depressiven

J. Michalak; N. F. Troje; T. Heidenreich

2010-01-01

281

Akute isolierte internukleäre Ophthalmoplegie  

Microsoft Academic Search

Zusammenfassung: Die internukleär Ophthalmoplegie ist die häufigste supranukleäre Störung der Blickmotorik. Pathologisch-anatomisches Korrelat ist eine Läsion des medialen Längsbündels, der Verbindung zwischen den Kerngebieten des III. und VI. Hirnnervs. Ein isoliertes, akutes Auftreten einer internukleären Ophthalmoplegie ist meist entzündlich bedingt, zum Beispiel bei einer multiplen Sklerose. Wir berichten über einen Patienten mit akut aufgetretener, isolierter internukleärer Ophthalmoplegie, bei dem mittels

Hilmar Krapf; Friederike Schmidt; Ralf Siekmann; Sigrid Friese; Wilhelm Küker

2000-01-01

282

Der Avatar: „Ein Wesen, eine Spielfigur, ein Medium, oder ein UI-Element?“  

Microsoft Academic Search

Einführung Im Rahmen der Diskussion um Ambient Intelligence wurde die Frage nach geeigneten Arten der Mensch-Maschine Kommunikation wieder neu gestellt. Die Informationstechnologie, die sich dem Menschen vermehrt anpassen soll, induziert einen neuartigen „Brückenschlag“ zwischen Mensch und Technik. Sollten demnach beide ebenbürtig miteinander kommunizieren, so war das bislang nur in der Form zu realisieren, dass der Mensch sich der Technik annähert

Ulrike Spierling; Fachhochschule Erfurt

283

Rauchen und Infektion der tiefen Atemwege  

Microsoft Academic Search

Zusammenfassung Zigarettenrauchen wirkt sich nicht nur auf die Atemwege, sondern auch auf das Lungenparenchym ungünstig aus. Das FEV ist bei akuten chronischen Rauchern vermindert. Längerfristiges Rauchen hat einen ungünstigen Einfluß auf die mukoziliare Aktivität. Nach neueren Forschungsergebnissen litten 1981 in den USA annähernd acht Millionen Menschen an chronischer Bronchitis. Zwischen dem Auftreten der chronischen Bronchitis und der Menge und Dauer

R. B. Brown

1987-01-01

284

Sinn und Möglichkeiten der Theoretischen Physik. Zum 300. Jahrestag von Newtons Philosophiae Naturalis Principia Mathematica  

NASA Astrophysics Data System (ADS)

Die Newtonschen Prinzipien und die aus ihnen gewonnene Erkenntnis der Existenz von Elementarkonstanten nach Planck, Einstein und Bohr erweisen sich zunehmend als tragfähiges Fundament nicht nur der Physik und ihrer Anwendung in der Technik, sondern überhaupt aller exakten Wissenschaften in breitestem Sinne des Wortes.Die physikalisch inhaltliche Klärung der Begriffe erfolgt seit Newton in engem Verbund mit der Entwicklung mathematischer Methoden. Diese Kombination erweist sich weiterhin als produktiv und sichert den Fortschritt der Physik und der exakten Wissenschaften.Wohl alle Probleme, die im Bereich der Technik Bedeutung haben können, lassen sich bei entsprechendem Aufwand bereits mit dem vorhandenen Fundus an Erkenntnissen und Methoden erfolgreich angehen.Der in der Wirklichkeit verankerte Zusammenhang von Gesetz und Zufall erweist sich als eine Manifestation der Dialektik in der Natur. Es gibt keinen absoluten Zufall. Sie kommt in allen Zweigen der Physik, nicht nur in der Thermodynamik und Quantenphysik, zutage, und muß bereits auf dem Niveau der Newtonschen Prinzipien und der Elementarkonstanten behandelt werden.Die theoretische Physik, so wie sie von Newton initiiert worden ist, wurde so angelegt, daß sie alle Seiten der Wirklichkeit, so weit sie in die Kompetenz der Physik fallen, umfaßt. Es besteht darum kein Gegensatz zwischen der klassischen Physik und der Quantenphysik. Es handelt sich lediglich um eine Differenzierung nach den unterschiedlichen physikalischen Inhalten und den angemessenen mathematischen Methoden, die natürlich von der Wahl der Probleme abhängen.Die theoretische Physik stellt eine allgemein zugängliche Zusammenfassung des gesicherten Wissens der Physik dar, das zugleich das Fundament der exakten Wissenschaften ist.Die theoretische Physik ist damit das Mittel der Verständigung innerhalb der Kooperation, die notwendig ist zur Lösung der großen komplexen Aufgaben der Wissenschaft und Technik.Translated AbstractThe Meaning and Abilities of Theoretical PhysicsThe Newtonean principles and - derived from them - the congnition of the exixtence of elementary constants according to Planck, Einstein and Bohr increasingly prove to be a strong base not only of physics and its apllication in technology but also of each kind of exact sciences in the broadest sense of the word.Since Newton the clarification of concepts with regard so their physical takes place in close connection with the development of mathematical methods. This combination proves to be further productive and ensures the progress of physics an of the exact sciences.Most likely all problems which may be of importance in the realm of life can be treated successfully - adequate expenditure taken for granted - with the existing fund of knowledge and methods.The connection between law and accident resting on reality proves to be a relation of complementarity (there is no absolute accident). This becomes evident in all branches in all branches of physics, not only in thermodynamics and quantum physics, and can be treated already on the level of the Newtonean principles and elementary constants.Theoretical physics as initiated by newton was designed to comprise all parts of nature. About that there is no contrast between classical physics and quantum physics. It is only a matter of differentiation with regard to the different physical contents and the appropriate mathematical methods, dependent of course on the choice problems.Theoretical physics represents a generally available concentration of the reliable knowledge of physics, which is at

Rompe, R.; Thiessen, P. A.; Treder, H.-J.

285

Biokompatible Keramische Werkstoffe  

NASA Astrophysics Data System (ADS)

In Medizinprodukten werden hauptsächlich folgende keramischen Werkstoffe eingesetzt: Aluminiumoxid und Zirkonoxid sowie Calciumphosphate, bioaktive Gläser und Glaskeramiken. In der Medizin gibt es zudem breite Anwendungsgebiete für weitere nichtmetallisch-anorganische Werkstoffe. Beispiele hierfür sind Brillengläser oder Glasfasern für Endoskope. Am häufigsten werden keramische Werkstoffe in Medizinprodukten im Zusammenhang mit dem menschlichen Skelett, den Knochen, Gelenken und Zähnen eingesetzt (Tabelle 13.1). In der Dentalmedizin finden keramische Werkstoffe beispielsweise in Form von Porzellankronen, mit Glas gefüllten Zementen oder künstlichen Gebissen eine breite Anwendung [2]. Bei Hüftgelenk-Endoprothesen werden Aluminiumoxid sowie Zirkonoxid für Hüftkugeln und Calciumphosphate in Form von Hydroxylapatit als Beschichtung auf Prothesenschäften eingesetzt.

Ha, Suk-Woo; Wintermantel, Erich

286

DEM?R METABOL?ZMASINDA, DEM?R EKS?KL???NDE VE DEM?R FAZLALI?INDA YEN?L?KLER  

Microsoft Academic Search

ÖZET Ya?am için hayati önemi olan demirin oksijen ta?in- masi, elektron transferi, DNA sentezi, immün sistem gi- bi birçok fonksiyonda görevi vardir. Eksikli?inde zihin- sel fonksiyonlarda gerilik ve kas gücünde azalma son yillarda tanimlanmi?tir intestinal demir emilimi, trans- ferrin reseptör yolu ile de?il, mobilferrin-integrin- para- ferritin yolu ile olmakta, bu emici hücrelerin bazolate- ral membraninda bulunan transferrin reseptörü \\

Zümrüt Uysal

287

Trade and Competition Policies for Oligopolies  

Microsoft Academic Search

\\u000a Zusammenfassung  Au\\\\enhandels- und Wettbewerbspolitik bei Oligopolen. - In diesem Aufsatz wird ein Modell vorgestellt, das die wechselseitigen\\u000a Beziehungen zwischen Au\\\\enhandel und Wettbewerbspolitik eines Landes abbildet, das bei einem Produkt ein vollstÄndiges Monopol\\u000a besitzt. Das Verhalten von Firmen und LÄndern wird durch ein dreistufiges Spiel modelliert, wobei in einem Teilspiel perfektes\\u000a Gleichgewicht herrscht. Von dem Herstellungsland wird angenommen, da\\\\ es zuerst seine

Simon G. B. Cowan

1989-01-01

288

The role of surgery and plastic reconstructive surgery in the treatment of chronic wounds  

Microsoft Academic Search

\\u000a Zusammenfassung  GRUNDLAGEN: Die veränderte Altersstruktur unserer Bevölkerung und neue Therapiemethoden chronischer Krankheiten bewirken,\\u000a dass die Anzahl von Patienten mit chronischen Wunden ständig steigt. METHODIK: Anhand der Literatur einerseits und den Erfahrungen\\u000a aus dem eigenen Krankengut werden die differentialtherapeutischen Möglichkeiten zwischen konservativen und chirurgischen Behandlungsstrategien\\u000a bei chronischen Wunden herausgearbeitet. ERGEBNISSE: Trotz der hohen Anzahl von Patienten mit chronischen Wunden gibt es wenig

R. Koller; A. Dobrovits

2008-01-01

289

Familial hypertrophic cardiomyopathy associated with prolongation of the QT interval  

Microsoft Academic Search

Zusammenfassung In dem vorliegenden Artikel wird über das Vorliegen einer familiären Häufung eines Long-QT-Syndroms in Verbindung mit einer hypertrophen Kardiomyopathie ohne nachweisbare Ausflusstraktobstruktion berichtet. Im EKG der drei betroffenen Familienmitglieder konnten QTc-Zeiten zwischen 467 und 496 msec, jeweils ein makroskopischer T-Wellen-Alternans und Einkerbungen der T-Welle in benachbarten Ableitungen nachgewiesen werden. Die angefertigten Echokardiogramme zeichneten sich durch eine erhebliche asymmetrische Hypertrophie

S. Peters; H. Rust; M. Trümmel; A. Brattström

2000-01-01

290

State of the art and future perspectives in cytostatic treatment of esophageal cancer  

Microsoft Academic Search

\\u000a Zusammenfassung  GRUNDLAGEN: Mehr als zwei Drittel aller Patienten mit Ösophaguskarzinom haben eine inoperable Erkrankung. Trotz Fortschritten\\u000a in diagnostischen und chirurgischen Techniken und verbesserter prä- und postoperativer Versorgung ist die Prognose der meisten\\u000a Patienten unverändert schlecht. Diese Übersichtsarbeit beschäftigt sich mit dem Einsatz der zytostatischen Chemotherapie bei\\u000a Patienten mit metastasiertem Ösophaguskarzinom. METHODIK: Um klinische Studien zwischen 1966 und 2006 zu identifizieren, wurde

M. Hejna

2007-01-01

291

Entwicklungen der Weltwirtschaft im Kontext der Finanzmarktkrise  

Microsoft Academic Search

GERMAN: Die im August 2007 ausgebrochene Finanzkrise erfüllt alle Kriterien einer systemischen Bankenkrise. Zahlungsschwierigkeiten häufen sich, die Kapitalisierung von Banken sinkt und Aktienkurse fallen, während die realen Zinssätze steigen. Ausschlaggebend für diese Entwicklungen ist der Vertrauensverlust zwischen den Banken nach den großen Abschreibungsverlusten, die aus dem Platzen der US-Sub-Prime-Blase resultieren. Staatliche Unterstützungsmaßnahmen in den USA und im Euro-Raum konnten bislang

Michael Landesmann; Roman Stöllinger

2009-01-01

292

Abgeschlossene und derzeit laufende adjuvante Therapieprotokolle bei Patienten mit operablem Mammakarzinom  

Microsoft Academic Search

Zusammenfassung  In der 1983 gegründeten Cooperativen Studiengruppe Mammakarzinom (COSTMA) argeiten derzeit etwa 50 onkologische Abteilungen\\u000a Österreichs zusammen. Durch die Ausgewogenheit chirurgischer, gynäkologischer und internistischer Teilnehmer und die demokratische\\u000a Führung der Studiengruppe konnte ein attraktives Forum geschaffen werden, dem sich laufend neue Interessenten anschließen.\\u000a In 4 Studien wurden zwischen 1983 und 1990 insgesamt 1127 Patientinnen randomisiert. Derzeit sind diese Protokolle in der

R. Jakesz; H. Hausmaninger; D. Depisch; E. Kubista; H. Samonigg; P. Steindorfer; M. Schemper; R. Kolb; K. Krauß; D. Manfreda; M. Stierer; G. Michlmayr; M. Fridrik; Ch. Dadak; F. Hofbauer; W. Horvath; Ch. Zielinski; V. Wette; P. Oppitz; M. Dünser; R. Lenzhofer; L. Müller; H. Ludwig

1991-01-01

293

The association between body-mass index and patient outcome in septic shock: a retrospective cohort study  

Microsoft Academic Search

\\u000a Zusammenfassung  HINTERGRUND: Es bestehen keine Daten über die Assoziation zwischen dem Body Mass Index (BMI) bzw. BMI Kategorien und der Mortalität\\u000a von septischen Schock-patienten. METHODEN: Die Datenbank einer interdisziplinären Intensivstation wurde retrospektiv nach\\u000a erwachsenen Patienten mit septischem Schock durchsucht. Von allen Patienten wurde der BMI, demographische, klinische und laborchemische\\u000a Parameter gemeinsam mit Outcomevariabeln dokumentiert. Die Studienpatienten wurden wie folgt anhand des

Bettina Wurzinger; Martin W. Dünser; Christoph Wohlmuth; Martina C. Deutinger; Hanno Ulmer; Christian Torgersen; Christian A. Schmittinger; Wilhelm Grander; Walter R. Hasibeder

2010-01-01

294

Magnetothermische untersuchungen an Cu-Al-Mn-legierungen (konzentrationsbereich der heusler-phase)  

Microsoft Academic Search

Ternäre Cu-Al-Mn-Legierungen mit konstantem Verhältnis Cu\\/Mn = 2\\/1 wurden im flüssigen und festen Zustand im Bereich zwischen dem Binärsystem Cu-Mn und nahezu reinem Al untersucht. Nach einer bestimmten Wärmebehandlung zeigen die Legierungen bei der Zusammensetzung Cu2MnAl (L21 Struktur, Heusler-Legierungen) bei Raum- temperatur maximale Magnetisierungswerte mit einer korrespondierenden Magnetonenzahl von nf = 3,5. Kühlt man diese Heusler-Legierung aus der Schmelze ab,

Ernst Wachtel; Franz Deissenrieder

1977-01-01

295

Digitale Foto- und VideodokumentationTeil 1  

Microsoft Academic Search

Bilder und Videos sind die geeigneten Medien zur Dokumentation von normalen und pathologischen Befunden. Zwischen den ersten\\u000a Farbbildern und der Entwicklung des ersten digitalen Fotoapparats liegen nur 150 Jahre. Wie schnell sich die Technik der digitalen\\u000a Foto- und Videodokumentation entwickelt und welche Rolle Sie für den HNO-Arzt in Klinik und Praxis spielt, wird in dem nachfolgenden\\u000a Beitrag beschrieben. Teil 1

H. Schmidt; N. Stasche

2000-01-01

296

Körperdysmorpher Wahn  

Microsoft Academic Search

In den aktuellen Klassifikationssystemen der WHO und der Amerikanischen Psychiatrischen Gesellschaft (APA) wird zwischen wahnhaften\\u000a und nichtwahnhaften Formen der körperdysmorphen Störung unterschieden. In der ICD-10 (Dilling et al. 1991) ist eine Zuordnung entweder zu den wahnhaften Störungen (F22.0) oder zur Hypochondrie (F45.2) vorgesehen. Beiden Krankheitsformen\\u000a gemeinsam ist eine intensive Beschäftigung mit dem eigenen Aussehen aus der Überzeugung heraus, missgestaltet zu

Dirk Schmoll

297

Overall survival and extent of surgery in adult versus elderly glioblastoma patients: A population based retrospective study  

Microsoft Academic Search

\\u000a Zusammenfassung  EINLEITUNG: In einer retrospektiven Analyse von in Vorarlberg therapierten Glioblastompatienten wurde der Einfluss des Resektionsausmaßes\\u000a auf das Gesamtüberleben in Abhängigkeit vom Lebensalter analysiert. METHODEN: Die therapeutische Intervention bei 48 Patienten\\u000a (Alter median 62,5 Jahre, zwischen 25 und 82 Jahren, 19 Frauen und 29 Männer) mit histologisch verifiziertem Glioblastom bestand\\u000a aus dem chirurgischen Eingriff (16 Biopsien, 18 Teil- und 14 Komplettresektionen)

Iris Zachenhofer; Roland Maier; Helmut Eiter; Bernhard Muxel; Manfred Cejna; Alexander DeVries; Karl Roessler

298

Jacob L. Talmon, The Origins of Totalitarian Democracy, Bd. 1, Boston 1952; Bd. 2: The History of Totalitarian Democracy Political Messianism: the Romantic Phase, Boston 1960  

Microsoft Academic Search

Jacob Leib Talmon (1916–1980) arbeitete als Student der Geschichtswissenschaft und Philosophie in Warschau an einer Seminararbeit\\u000a über die ultrademokratische französische Verfassung von 1793, als die Parteisäuberungen in Moskau 1937\\/38 mit großen Schauprozessen\\u000a ihren Höhepunkt erreichten. Die Analogie zwischen dem Jakobinerterror des Jahres II und den Ereignissen in der Sowjetunion\\u000a sprang ins Auge: „Wer hatte die Russische Revolution auf so kriminelle

Uwe Backes

299

Über die Wirkung der Röntgenbestrahlung auf das embryonale Wachstum  

Microsoft Academic Search

Zusammenfassung 1.Die Arbeit stellt sich die Aufgabe, die doppelte Abhängigkeit zwischen den quantitativ verschiedenen Röntgenstrahlendosen und dem Alter des wachsenden Organismus einerseits, den nachfolgenden änderungen im bestrahlten Organismus andererseits zu studieren. Versuchsmaterial: 5–15 Tage alte Axolotlenembryonen (vom Anfang der Gastrulation bis zum Freiwerden aus den Eihüllen) und Larven der FliegeDrosophila melanogaster.2.Im Laufe der Entwicklung des Embryo (Axolotlen,Drosophila-Larven) sinkt die Röntgenempfindlichkeit;

N. M. Woskressensky

1928-01-01

300

Gender aspects in medical publication – the Wiener klinische Wochenschrift  

Microsoft Academic Search

\\u000a Zusammenfassung  FRAGESTELLUNG UND ZIEL: Medizin ist ein akademischer Fachbereich, in dem nach wie vor ein Ungleichgewicht zwischen Männern\\u000a und Frauen herrscht. Weltweit sind mehr als die Hälfte aller Medizinstudenten weiblich, jedoch erreicht nur ein kleiner Prozentsatz\\u000a später eine Führungsposition. Das Ziel der vorliegenden Arbeit war es, zu analysieren, wie diese Situation in einer allgemein-medizinisch-wissenschaftlichen\\u000a Fachzeitschrift reflektiert wird. METHODIK: Alle Manuskripte, die

Andrea Heckenberg; Christiane Druml

2010-01-01

301

Vertrauensfragen  

Microsoft Academic Search

Zusammenfassung  Vertrauen oder Kontrolle als Führungsprinzip — vor dem Hintergrund der Unternehmens- und Informationssicherheit ist die Entscheidung\\u000a zwischen beiden Prinzipien in den vergangenen Monaten schwieriger geworden. Auf der einen Seite haben seit 2009 eine ganze\\u000a Reihe gestandener und hochrangiger Manager ihre Posten verloren und ihre Unternehmen in Reputationstiefs gestürzt, weil sie\\u000a Mitarbeiter zu streng überwacht und dabei Datenschutzgrenzen überschritten haben, die

Johannes Wiele

2011-01-01

302

Postoperative Endophthalmitis nach IOL-Implantation  

Microsoft Academic Search

\\u000a Zusammenfassung  Analyse postoperativer purulenter Endophthalmitiden nach Intraokularlinsen-Implantation während des Quinteniums 1985 bis 1989.\\u000a Unter den 7650 Operationen mit Implantation von Hinterkammerlinsen ereigneten sich acht akute postoperative intraokulare Infektionen\\u000a zwischen dem zweiten und achten Tag. Die Inzidenz liegt mit 0,1% im Mittel des einschlägigen Schrifttums von 0,05 bis 0,5%.\\u000a Als Behandlung der Wahl erwies sich der gleichzeitige Einsatz einer maximalen systemischen Antibiotikatherapie

H. Freyler; M. Amon

1990-01-01

303

Soziale Netzwerke  

Microsoft Academic Search

\\u000a Mit dem Konzept des sozialen Netzwerks werden in der Soziologie Beziehungsgeflechte von Individuen, Gruppen, Organisationen\\u000a oder auch Gesellschaften beschrieben und analysiert. Diese Netze können z. B. hinsichtlich Umfang und Dichte, aber auch hinsichtlich\\u000a der Qualität der Beziehungen oder des Austauschs zwischen den Mitgliedern näher untersucht werden. Werden Individuen betrachtet,\\u000a stehen zumeist die soziale Integration und der Austausch z. B. mit

Harald Künemund; Martin Kohli

304

Zwischen Berechenbarkeit und Nichtberechenbarkeit. Die Thematisierung der Berechenbarkeit in der aktuellen Physik komplexer Systeme  

Microsoft Academic Search

Between Calculability and Non-Calculability. Issues of Calculability and Predictability in the Physics of Complex Systems. The ability to predict has been a very important qualifier of what constitutes scientific knowledge, ever since the successes\\u000a of Babylonian and Greek astronomy. More recent is the general appreciation of the fact that in the presence of deterministic\\u000a chaos, predictability is severely limited (the

Jan C. Schmidt

2003-01-01

305

Diskrepanzen und Kongruenzen: Das Dilemma des afrikanischen Kindes zwischen Familie und Schule  

NASA Astrophysics Data System (ADS)

This article expounds the theory that the failure of school is due to the incompatibility of the educational goals of school and traditional upbringing in Africa. The thesis is put forward by adherents of the psychoanalytical model of child development and seeks to emphasize the discrepancies between the childhood where children are not frustrated and where their needs are cared for and the school education which represses the drives and its socialization of children. Finding a number of anthropological studies are discussed and reinterpretations of the ethno-psychoanalytical materials attempted. Neither the evaluation of childhood in Africa nor the theory that with school come wholly new expectations of behaviour (e.g., a performance requirement) can no longer be maintained. In conclusion, other explanations for the difficulties encountered by school in Africa are offered.

Bauer, Annemarie

1986-03-01

306

Zur Kenntnis der Wechselbezichungen zwischen Bodenschädlingen, Unkräntern und deren Bekämpfungsma B nahmennahmen  

Microsoft Academic Search

\\u000a Summary  Although our investigations may be considered as orientation work only and we are still well aware of the fact that a new\\u000a problem has been merely touched by us, we are convinced that there exists an evident dependency among weeds, soilpests and\\u000a their control measures. The application of soil insecticides may in some cases increase the quantity of weeds on

Milan Maceljski

1968-01-01

307

Zwischen existentieller Sinnerfüllung und Burnout: eine empirische Studie aus existenzanalytischer Perspektive  

Microsoft Academic Search

\\u000a Abstract  The phenomenon of burnout is interpreted on the background of psychoanalytic and socialpsychological perspectives from an\\u000a existential analytic point of view. The basic condition of its origin is seen as a nonexistential attitude towards life, stemming\\u000a from a deficit in personal-existential fundamental supports. A person in this position longs for a fulfilled life but has\\u000a no orientation in the most

Anton Nindl; Alfried Längle; Erich Gamsjäger; Joachim Sauer

2006-01-01

308

Zwischen Commonsense und Wissenschaft Mathematik in der Erziehungsphilosophie A. N. Whiteheads  

NASA Astrophysics Data System (ADS)

Obwohl Whitehead heute wie selbstverständlich als Philosoph rezipiert wird, so hat er seine wissenschaftliche Laufbahn doch als Mathematiker begonnen. Lange Zeit war er gemeinsam mit Bertrand Russell als Autor der Principia Mathematica unter Mathematikern und mathematischen Logikern deutlich besser bekannt als unter Philosophen. Doch selbst von denjenigen, die sich mit Whiteheads Überlegungen zur Metaphysik, zur Wissenschaftsgeschichte und zur Theologie befassen, werden seine Schriften zur Philosophie von Erziehung und Bildung häufig kaum beachtet. So entgeht es leicht, dass Whitehead nicht nur ein auf theoretischem Gebiet brillanter Mathematiker war, sondern sein theoretisches Fachwissen im Hinblick auf pädagogische und didaktische Relevanz fortwährend reflektiert hat.

Sölch, Dennis

309

Untersuchungen über die Wechselwirkung zwischen Licht und Chemosynthese am Beispiel von Nitrobacter winogradskyi  

Microsoft Academic Search

1.In Nitrobacter winogradskyi, the influence of light on the respiratory chain enzymes, on oxidative phosphorylation and on CO2 fixation of whole cells was investigated by use of various methods. In addition, the effect of light on coupling reactions was studied.2.The spectral light sensitivity increases progressively from visible blue to ultra violet. The action spectrum is in accordance with the absorption

Eberhard Bock

1970-01-01

310

Wissenschaft bei einer Nachrichtenagentur: Balanceakt zwischen rasendem Reporter und rasendem Forscher  

Microsoft Academic Search

Der Physik-Nobelpreis für einen Deutschen, eine Vogelgrippe-Mutation und in 40 Zeilen den Stand der Stammzellforschung — Wissenschaftsjournalismus\\u000a bei einer Nachrichtenagentur ist vor allem von der Aktualität und der Konzentration aufs Wesentliche geprägt. Die Deutsche Presse-Agentur (dpa) beliefert als Marktführer in Deutschland fast alle deutschen Tageszeitungen und wichtigen Radio- und Fernsehsender. Über\\u000a eine eigene Online-Redaktion aktualisiert dpa zudem zahlreiche Internet-Nachrichtenseiten live.

Till Mundzeck

311

Über die Entwicklung der Mathematik in Westeuropa zwischen 1100 und 1500  

Microsoft Academic Search

\\u000a Abstract  The twelfth century was a period of transmission and absorption of Arabic learning though it filtered outside of the Arabic\\u000a world as early as the second half of the tenth century. In general, the lure of Spain began to act only in the twelfth century,\\u000a and the active impulse toward the spread of Arabic mathematics came from beyond the Pyrenees

H. L. L. Busard

1997-01-01

312

Zwischen Naturwissenschaft und Symbolik: Zum Spezifischen der Syphilisdarstellung in der Literatur um 1900  

Microsoft Academic Search

\\u000a Abstract.  The particular significance of syphilis as a literary theme at the turn of the 20th century is attributable to a combination\\u000a of scientific developments and social conditions which include the germ theory, the idea of biological inheritance, the bourgeois\\u000a fear of degeneration and the newly emerging discipline of public health. Symptoms that ranged from physical disfigurement\\u000a to neuropsychiatric manifestations, which

Hendrik Voss

2006-01-01

313

„Tag der Allgemeinmedizin” - Ein Beitrag zur Entwicklung einer gemeinsamen regionalen Plattform zwischen Hausarztpraxen und einer Universitätsabteilung  

Microsoft Academic Search

Aims: The increasing number of academic medical departments and consecutively slowly increasing number of collaborating general practices require new methods when seeking for pro- mising strategies to cooperate in research, teaching and continu- ing education. Methods: Therefore the University of Heidelberg, Department of General Practice and Health Sevices Research established a new event of continuing medical education on the campus

J. Szecsenyi; A. Wiesemann; O. Stutzke; C. Mahler

2006-01-01

314

Wechselwirkung Zwischen Einer Stosswelle und Einer Turbulenten Stroemung (Interaction Between Shock Wave and Tubular Flow).  

National Technical Information Service (NTIS)

The interaction between a shock wave and a compressible turbulent flow is investigated in a shock tube using laser speckle photography. The aim is to determine how the characteristics of the turbulent flow can be changed due to the compression by the shoc...

W. Merzkirch

1990-01-01

315

Cytogenetische Untersuchungen an Taraxacum im Raume von Wien. II. Hybriden zwischen T. officinale und T. palustre  

Microsoft Academic Search

Zusammenfassung Die Auswertung von Kreuzungsexperimenten zeigt, daß beiTaraxacum in einem weit höheren Maß, als auf Grund der in dieser Gattung so weit verbreiteten apomiktischen Fortpflanzung ursprünglich anzunehmen war, mit Artbastarden gerechnet werden muß. Die Hybriden treten nioht nur bei Kreuzungen von — im Raume von Wien häufigen — diploiden Pflanzen auf, sondern auch bei Kreuzungen von diploiden Pflanzen mit tetraploiden,

Dietrich Fürnkranz

1961-01-01

316

Über den Wirkungsmechanismus des Ephedrins und den Unterschied in der Wirkungsstärke zwischen seinen Isomeren  

Microsoft Academic Search

Zusammenfassung 1.Die Blutdruckwirkung des Ephedrins ist nicht als Herzwirkung aufzufassen. Sie ist eine rein periphere Gefäßwirkung und kommt dadurch zustande, daß durch das Ephedrin die Gefäße für Suprarenin sensibilisiert werden. An und für sich unwirksame Ephedrinkonzentrationen verursachen an den mit verdünnten Suprareninlösungen durchströmten Froschgefäßen eine starke, langanhaltende Vasokonstriktion.2.Mit derselben Methode lä\\\\t sich auch die sensibilisierende Wirkung des Kokains und die

Otto Schaumann

1928-01-01

317

Fakt und Fiktion: die Autobiographie im Spannungsfeld zwischen Theorie und Rezeption  

Microsoft Academic Search

Many literary dictionaries still define an autobiography as a deliberate, structured retrospective of the writer’s own life, characterized by a perspective that suggests a certain unity or harmony. Many of these characteristics, however, are now taken for granted less and less. Today, the autobiographer rarely delivers a text that is organized coherently and presents life as a whole.\\u000aThis thesis

Jerker Spits

2008-01-01

318

The Kepler - Mästlin correspondence. (German Title: Der Briefwechsel zwischen Kepler und Mästlin)  

NASA Astrophysics Data System (ADS)

The correspondence between Kepler and Mästlin covers the period from 1594 to 1620. It is interrupted by year-long pauses and ends a full 10 years before Kepler's death. Initially, Mästlin is quite open to Kepler's new ideas (Mysterium Cosmographicum), but later he showed little understanding for the revolutionary innovations of the mature Kepler. Kepler's insistent wishes and the unfounded fear that Kepler might publish his letters gave rise to long periods of silence. Some passages in letters of his associates suggest that Mästlin suffered from melancholy (in today's terms: depression) induced by age.

Seck, Friedrich

319

Homogeneity and Symmetry in DEM Models of Cone Penetration  

NASA Astrophysics Data System (ADS)

A three-dimensional numerical model was implemented to PFC3D Code to simulate cone penetration test in Ticino sand in a calibration chamber. The model is calibrated using laboratory test results. The full/half/quarter calibration chamber was used to examine the effect of symmetry on the results. Examination of specimen homogeneity was done by (i) visual observation of the network of the contact forces developing between particles, (ii) examination of the porosity, d50 and Cu distributions inside the specimen by using a representative elementary volume (REV). Some overall results from these simulations are also presented here and compared with the experimental results from a calibration chamber test database.

Butlanska, Joanna; Arroyo, Marcos; Gens, Antonio

2009-06-01

320

Neue Invalidisierungshäufigkeiten aus dem Material der deutschen gesetzlichen Rentenversicherung  

Microsoft Academic Search

\\u000a Summary  The report constitutes an attempt, made for the first time since the war, to ascertain, on the basis of statutory pensions\\u000a insurance data, factual disablement rates in the Federal Republic of Germany. Previous attempts could not produce satisfactory\\u000a results because the number of insured persons necessary for such a study was unknown. This gap has now been filled by a

Horst Löwe

1966-01-01

321

Two Scale Model (FEM-DEM) For Granular Media  

Microsoft Academic Search

\\u000a The macroscopic behavior of granular materials, as a consequence of the interactions of individual grains at the micro scale,\\u000a is studied in this paper. A two scale numerical homogenization approach is developed. At the small-scale level, a granular\\u000a structure is considered. The Representative Elementary Volume (REV) consists of a set of N polydisperse rigid discs (2D),\\u000a with random radii. This

Micha? Nitka; Gaël Combe; Cristian Dascalu; Jacques Desrues

322

Enossale Implantatversorgung von Tumorpatienten mit dem Bone-Lock-System  

Microsoft Academic Search

Zusammenfassung Die implantologische Versorgung von Patienten nach ablativer Tumorchirurgie und Defektrekonstruktion erfolgt meist abseits strenger Maßstäbe der Erfolgsbeurteilung. Deshalb untersuchten wir die von Juni 1990 bis Juni 1996 bei 58 Tumorpatienten enoral gesetzten 210 Implantate regelmäßig nach. Verwendung fand ausschließlich das enossale Bone-Lock-Implantatsystem (Howmedica Leibinger GmbH, Freiburg). Untersucht wurden der Plaqueindex (Silness und Löe), der Sulkusblutungsindex (Löe), die Sondierungstiefe, die

A. Kovács; Johann Wolfgang

1998-01-01

323

Case Study: Dem Bones - Forensic Resurrection of a Skeleton  

NSDL National Science Digital Library

This is a case study for high school and undergraduate students in anatomy and physiology. In particular this case study explores anatomy of the skeleton (including landmarks), sex and age determination via pelvic and skull morphology. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

Alease S. Bruce (University of Massachusetts-Lowell Department of Health and Clinical Sciences)

2001-07-09

324

10 Jahre Erfahrung mit dem Goretexfaden® bei Frontalissuspension  

Microsoft Academic Search

\\u000a Zusammenfassung  Bei angeborener Ptose mit einer schlechten Levatorfunktion ist zur Hebung des Lides nur die Frontalisschlinge möglich.\\u000a \\u000a Verschiedene homologe und autologe Materialien wurden als Frontalisschlinge verwendet. Bekannte Komplikationen sind Infektion\\u000a und Abstoßung. Im Zeitraum 1990 bis 2000 wurden 42 Patienten mit einer angeborenen Ptose und schlechter Levatorfunktion einer\\u000a Frontalisschlingenoperation unterzogen. 39 Patienten wurden mit einem Goretexfaden, 3 Patienten mit einem Mersilenefaden

K. Müllner; S. Lindner; A. Langmann

2002-01-01

325

Interview mit dem Psychiater und Psychoanalytiker Berthold Rothschild  

Microsoft Academic Search

\\u000a Summary  Berthold Rothschild, in an interview, speaks about the part, which greed and shamelessness have played in the development\\u000a of the economic crisis. His thesis is as follows: The cause cannot be found in the individual psychological area, but in the\\u000a group development and capitalism, which have mutually reinforced each other. In what follows, the regressive ego- and superego-processes\\u000a occurring in

Berthold Rothschild

2010-01-01

326

Interpolation of phenological phases on a digital elevation model (DEM)  

NASA Astrophysics Data System (ADS)

The main objective of the VegDyn project (a cooperation between Joanneum Research, Institute of Digital Image Processing, LFZ Raumberg-Gumpenstein and ZAMG) consists in quantifying and modelling the relationship between individual growth stages of grassland on the one hand and atmospheric parameters, remotely sensed data and phenological observations on the other. The model simulates the beginning and the end of the vegetation period and the growth stages of grassland with temperature as input variable. Thus it will be possible to explore changes of the timing of the vegetation period and the growth stages of grassland in possible future climate scenarios, which are calculated by climate models. In the context of the VegDyn project we developed methods for the spatial interpolation of phenological phases on a digital elevation model with a 250 m grid resolution in the complex terrain of the Alps. The final result is a series of maps of long term mean entry dates and maps of entry dates of individual years, which can for instance be related with the Net Difference Vegetation Index (NDVI) parameter maps from satellite observations. Apart from the yearly input via the conventional observational network based on voluntary observers and the input via the web interface, the Austrian phenological data base is still being supplemented by data from the paper archive. The elevation of the station network ranges from 100 to 1700 m. The station density can reach up to 100 or more stations per phase and season during 1951 - 2009. From more than 280 observed phases including phases from wild (woody and herbaceous) and agricultural plants those have been selected, which are related to cultivated grassland and which can be detected by remote sensing. In order to be selected for spatial interpolation the phase must satisfy a number of criteria: a minimum number of stations and, in order to have a meaningful long term mean entry date, a minimum number of observations per station during 1951 - 2009. If this minimum number is set to 20 years, there remain averagely 129 stations per phase, which fulfil the criterion. An average observer notes about 51 phases. This results in a rather high year to year fluctuation of observing stations and observed phases. The applied interpolation methods are linear regression with the entry dates as dependent and the station coordinates as independent variables, height reduced inverse distance weighting, and height reduced mean. For the latter two methods the search radius and the number of selected nearest neighbouring stations for interpolation have been optimised via trial and error. Interpolation quality is being checked via spatial cross validation, where the average anomaly, explained spatial variance (correlation squared or RSQ) and the root mean squared error (RMSE) serve as quality criteria. The resulting set of maps contains the interpolated long term mean phenological entry date and the entry dates of a series of individual years (1990 - 2009) for each of the three methods. This enables a comparison of the three interpolation methods and an evaluation of the quality of the results.

Schöngaßner, Thomas C.; Scheifinger, Helfried

2010-05-01

327

Channel Slopes on Amazon Basin Rivers From the SRTM DEM  

NASA Astrophysics Data System (ADS)

Changes in surface water storage (S) and discharge (Q) are poorly known globally but are critical for constraining the terrestrial branch of the water cycle. To date, only the SRTM mission provides global measurements of both surface water area and elevation. However, little is known about the instrument performance for collecting delta-S and Q. The Amazon Basin is a particularly appealing target given its sparse gauge density, lack of continuous and reliable slope data that can be used in the estimation of discharge, and complexity of flow hydraulics. We have used SRTM elevation data in conjunction with flow distance to estimate water surface slope for the area 0S-8S, 72W-54W. Using a 3rd order polynomial fit to the distance-elevation data, slope values of the mainstem Amazon range from less than 0.5 cm km-1 downstream of Obidos to 4.10 cm km-1 3000 km upstream of this location. The central Amazon slope ranges from 1.86 cm km-1 to 3.10 cm km-1 from Manaus to the Rio Japura (about 800 km upstream). Local slopes for specific gauge locations were achieved using both a linear fit to the data and the polynomial fit. The slope value at Itapeua, about 430 km upstream of Manaus, was found to be 3.22 cm km-1 using a linear fit, and 2.65 - 2.79 cm km-1 using a 3rd order polynomial fit, for a reach of 24 km. The slope value for Manacapuru, about 90 km upstream of Manaus, was determined to be 3.56 cm km-1 using a linear fit and 1.97 - 2.12 cm km-1 for a reach of 70 km centered on the local gauge. This slope is used in the Manning equation (n = 0.03) with depth values from navigation charts and river width measured from JERS-1 SAR imagery to yield discharge values for Manacapuru of 93,500 m3 sec-1and for Itapeua of 81,900 m3 sec-1. The observed discharge value at the Manacapuru gauge is 96,300 m3 sec-1 over an 11-day average in February for the years 1973-1991. The average observed discharge value for Itapeua is 83,100 m3 sec-1 for the same time period.

Hendricks, G.; Alsdorf, D. E.

2004-12-01

328

7.5-Minute Digital Elevation Model (DEM)  

NSDL National Science Digital Library

The US Geological Survey (USGS) performs a wide variety of tasks related to the environment including data acquisition for use in geographical information systems. This data set provides elevation data for the contiguous US, Hawaii, and Alaska. Data are in one-by-one degree blocks and available via an online interface or by ftp download (instructions provided in the User Guide). Specific data can be located via alphabetical list, state, or a graphic of the US.

329

On depressional storages: The effect of DEM spatial resolution  

NASA Astrophysics Data System (ADS)

Depression storage can be a significant storage element on a watershed surface, accounting for the retention of much water. Over the past decade, many models were developed to derive landscape features. However, relatively little is known about the impact of changing the spatial and/or temporal resolutions on subsequent features. In this paper, the surface topography was measured with the aid of a laser scanner with millimeter-resolution. Emphasis was laid on quantifying the effect of changing spatial resolution upon geometric properties of depressional storages. Digital mapping allowed the visualization of the location and topology of potential water surfaces and the manner in which water might move from one depression to another. From the pond analysis and associated spatial mapping, it became clear that most geometric characteristics relating to size and spatial location of depression storage, including area, volume and depth, are scale dependent. The relationship between the contributing area of each depression and the surface area of the same depression at each pour depth was established, and the organization inherent in such relationship was explored. Furthermore, it was found that these geometric objects may best be described by resorting to fractal geometry, a popular tool for quantifying variability across scales.

Abedini, M. J.; Dickinson, W. T.; Rudra, R. P.

2006-03-01

330

Fahrzeug-Außengeräusch  

NASA Astrophysics Data System (ADS)

Wirtschaftliches Wachstum ist mit steigenden Anforderungen an Mobilität und Transport verknüpft. Zukunftsorientierter Fortschritt muss hierbei die Wirkungen von Verkehrsgeräuschen auf Mensch und Umwelt berücksichtigen, um eine hohe Lebensqualität sicherstellen zu können. Mehr als die Hälfte der Bevölkerung in der EU fühlt sich durch Verkehrslärm belästigt oder befürchtet direkte Auswirkungen auf Gesundheit und Wohlbefinden. Nach einer repräsentativen Umfrage des Umweltbundesamtes fühlen sich durch Straßenverkehrslärm 20 % der Bevölkerung stark oder wesentlich belästigt (UBA 2008). Daher ist das "Fahrzeug-Außengeräusch“ Gegenstand zahlreicher Forschungsprojekte zu Themen wie Identifikation wesentlicher Geräuschquellen, Zusammenhang zwischen Verkehrsgeräusch und Belästigung, medizinische Folgen aufgrund chronischer Lärmexposition, Geräuschqualität, Entwicklung neuer Methoden und Technologien zur Fahrzeug-Außengeräuschmessung und das Fahrzeug-Außengeräusch als wesentliches Produktattribut, das aktiver Gestaltung bedarf.

Genuit, Klaus

331

Definition und Beschreibung klimatologischer Extreme und ihr Zusammenhang mit der Zirkulation. T. 1. Definition und Beschreibung klimatologischer Extreme. (Definition and description of climatological extremes and their interdependence with circulation patterns. Pt. 1. Definition and description of climatological extremes).  

National Technical Information Service (NTIS)

It is well known that knowledge on average weather conditions is not sufficient for obtaining climatological information of practical relevance. As a rule, it is the extreme weather conditions that have the most dramatic consequences for agriculture, natu...

P. C. Werner U. Boehm U. Werner

1994-01-01

332

Schlusswort  

NASA Astrophysics Data System (ADS)

Im Rahmen des BMBF-Verbundprojektes ProMoLeS wurde bereits zu Projektbeginn der Industriearbeitskreis Montagelösungen für die Leistungselektronik" gegründet, welcher unter der organisatorischen und fachlichen Leitung vom bayerischen Cluster Leistungselektronik im ECPE e.V. eine Plattform für den Austausch zwischen Unternehmen der Leistungselektronik bietet. Ziel des Industriearbeitskreises ist es daher, mit neuen und innovativen Lösungen einen Beitrag zur Sicherung der Montagearbeitsplätze am Standort Deutschland zu leisten. Der Arbeitskreis richtet sich an Fach- und Führungskräfte von Unternehmen, die leistungselektronische Systeme oder deren Komponenten entwickeln und herstellen: Entwicklungsingenieure, Fertigungsplaner, Fertigungstechnologen, Fertigungsleiter, Arbeitsorganisatoren, Qualitätsbeauftragte sowie Wissenschaftler an Hochschulen, die auf den genannten Gebieten arbeiten. Ziel und Zweck des Arbeitskreises ist es, Wissen und Erfahrung auszutauschen, persönliche Kontakte von Fachleuten zwischen Unternehmen und wissenschaftlichen Einrichtungen zu verstärken, Kooperationen in dem Gebieten der Entwicklung, Fertigung, Logistik oder Qualifizierung aufzubauen, strategisch relevante Themen zu erkennen und gemeinsame Forschungs- und Entwicklungsprojekte zu initiieren. Damit soll die Wettbewerbsfähigkeit der Unternehmen verbessert und Arbeitsplätze am Standort gesichert werden.

Pfeffer, Michael; Reinhardt, Andreas

333

Cytochrom b-Sequenz-Vergleiche zwischen Rothirsch (Cervus elaphus hippelaphus) , Damhirsch (Dama dama dama) und Reh (Capreolus capreolus capreolus)  

Microsoft Academic Search

Von Rothirsch(Cervus elaphus hippelaphus), Damhirsch(Dama dama dama) und Reh(Capreolus capreolus capreolus) wurden mit Hilfe der Kapillarelektrophorese die Nukleotid-Sequenzen des Cytochrom b-Gens zum größten Teil bestimmt. Um, ausgehend von diesen Sequenzen, Aussagen über die verwandtschaftlichen Beziehungen dieser drei Tierarten zueinander machen zu können, wurden die Basen- bzw. die Aminosäurensubstitutionsraten ermittelt. Auch das Verhältnis von Transitionen zu Transversionen wurde berechnet. Die Homologien

Stefanie Zimmermann; R. Zehner; A. Herzog

1998-01-01

334

Korrelation zwischen verminderter Reparaturfähigkeit für UV-Läsionen und hoher Spontanmutabilität eines Mutatorstammes von E. coli K-12  

Microsoft Academic Search

The biauxotrophic strain of E. coli K-12 (?), met 1\\/his 7, which exhibits an 8 times higher rate of met1?met+-backmutation as compared with the parent strain met 1, was found to be also more sensitive to UV irradiation. In addition, the maximum UV induction of prophage ? occurs at lower doses, and the capacity of the strain to propagate induced

Georges Mohn

1968-01-01

335

Correspondence between Tycho Brahe and Thaddeus Hagecius - the beginnings. (German Title: Briefwechsel zwischen Tycho Brahe und Thaddaeus Hagecius - Anfänge)  

NASA Astrophysics Data System (ADS)

The voluminous correspondence of Tycho is one of the most interesting sources of the history of astronomy. Nevertheless, it is until today poorly known and rarely cited (Thoren being a counter-example), and a modern critical edition is lacking. Among Tycho Brahe's most frequent correspondents are Wilhelm, the landgrave of Hesse, and his court astronomer Ch. Rothmann. At third place - regarding the number of letters - we find the court physician and astronomer Thaddaeus Hagecius from Prague. Their correspondence lasted from 1575 tpo 1597. This article presents and analyses the most important letters of the Hagecius - Brahe correspondence.

Smolka, Josef

336

Vom Armen- und Arbeitshaus zu Hartz-IV Eine kurze Geschichte der staatlichen Armen- und Arbeitslosenverwaltung zwischen Repression und Almosentransfer  

Microsoft Academic Search

feudalistischen Ständegesellschaft war ‚arbeitslos' maximal der leibeigene Bauer, der nach der Fronarbeit oder nach der Einbringung der Ernte zeitlich eng befristet ‚ohne Arbeit' war - sozusagen nach Feierabend. Das Charak- teristikum des Feudalismus waren nicht fehlende Arbeitsplätze, sondern im Gegenteil der permanente Mangel an menschlicher Arbeitskraft für Fron- und Kriegsdienste im Interesse der herrschenden Adelsklasse. Die Ausbeu- tung der Fronarbeit

Egbert Scheunemann

337

Between Promise and Threat : Antibiotics in Foods in West Germany 1950-1980.  

PubMed

ZUSAMMENFASSUNG: Produktion und Verbrauch von Nahrungsmitteln sind traditionell mit weit reichenden Ängsten verknüpft. Bezogen diese sich in vormodernen Gesellschaften vorrangig auf eine ausreichende Versorgung, sind sie in der modernen Industriegesellschaft eher auf die Qualität der Nahrungsmittel gerichtet. In diesem Zusammenhang spielten in der Nachkriegszeit Antibiotika eine zentrale Rolle. Der Aufsatz stellt die Einführung der Antibiotika in die westdeutsche Veterinärmedizin, ihre frühe Diskussion als Konservierungsmittel und ihre wachsende Rolle als Wachstumsförderer dar. Vor dem Hintergrund einer zunehmend industrialisierten, auf Maximierung ausgerichteten Produktionspolitik werden die Rolle der Veterinäre, der Forschung und der wissenschaftlichen Experten sowie die Probleme der Regulierung des Antibiotikaeinsatzes in der Landwirtschaft diskutiert, die in die Entstehung eines unübersichtlichen grauen Marktes für Antibiotika und die Verlagerung ihres Einsatzes in die Therapie mündete. Besondere Aufmerksamkeit wird der Frage zugewandt, welche Rolle das Vertrauen und die Ängste der Verbraucher in diesem Prozess spielten. PMID:22941180

Thoms, Ulrike

2012-09-01

338

Steriod-Rezeptoren und Mamma-Karzinom  

Microsoft Academic Search

Schlufolgerung  Somit erweist sich die immunohistochemische strogen-Rezeptor-und Progesteron-Rezeptor-Bestimmung gegenber dem biochemischen\\u000a Steroid-Rezeptor-Nachweis als empfindliche Methode. Zudem zeigt sich keine Korrelation zwischen der Hhe des Progesteron-Rezeptors\\u000a und der Zykluphase z.Z. der Brustoperation. Wie Badwe und Mitarbeiter (2) beim Vergleich berlebenszeit in Korrelation zur\\u000a Zyklusphase z.Z. der Brustoperation beim Mammakarzinom gezeigt haben, mssen auch nach unseren vorliegenden Ergebnissen der\\u000a immunohistochemischen Steroid-Rezeptorbestimmung weitere Faktoren

B. Karbowski; E. Vollmer; H. P. G. Schneider

1993-01-01

339

Der Padagogische Umgang mit dem weltanschaulich-religiosen Pluralismus auf dem Prufstein (A Touchstone for the Pedagogical Approach to Ideological-Religious Pluralism).  

ERIC Educational Resources Information Center

Examines the model for ethical-religious instruction introduced in Brandenburg (Germany) from a constitutional and structural-pedagogical viewpoint. Points to problems with both the proposed "uniform" and "plural" models: the first infringes on minorities' interests and the second presupposes a high degree of cooperation between churches and state…

Nipkow, Karl Ernst

1996-01-01

340

Identification of rockfall hazard at Little Mill Campground (Uinta National Forest, Utah, USA) by DEM analysis  

Microsoft Academic Search

The Little Mill Campground lies on the bottom of the deeply incised American Fork Canyon and is surrounded by high cliffs made of dolomite and limestone. Rock-fall activity is quite well known in the study area. Since the 1990ies the rock-fall events are inventoried. Potential rock instabilities were identified and a preliminary hazard assessment shows that most campsites are downslope

Oppikofer Thierry; Jaboyedoff Michel

341

Simulations of Fracture and Fragmentation of Geologic Materials using Combined FEM/DEM/SPH Analysis  

SciTech Connect

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC, permitting the simulation of fluid-structure interaction. We will present results from a study of detonation-induced fracture and fragmentation of geologic media surrounding a tunnel using LDEC.

Morris, J P; Johnson, S M

2007-04-05

342

A Combined DEM/FEM Multiscale Method and Structure Failure Simulation under Laser Irradiation  

SciTech Connect

Analysis of a variety of engineering problems requires computation at different length scales. A combined discrete/finite element numerical method is proposed and developed in this paper to meet this requirement. This method performs discrete element method at meso-scale to reach necessary precision, and finite element method at macro-scale to save the computation time and cost. The key point for this method is to define a special transition layer between discrete element zone and the finite element zone. We apply this new method to simulate the failure responses of a pre-stressed aluminum plate and a cylindrical shell with inner pressure under laser irradiation with the combination codes of DM3 (a 3D Discrete Meso-Element Dynamic Method)/plane FEM and DM3/shell FEM developed in this lab, respectively. It finds good agreement between the current computational results and the reported results in the references.

Tang Zhiping; Xu Jianlong [Key Laboratory for Mechanical Behavior and Design of Materials (LMBD), University of Science and Technology of China, Hefei 230026 (China)

2006-07-28

343

BORLAMANIN DEM R ESASLI T\\/M MALZEMELERDE YORULMA DAVRANI INA ETK S  

Microsoft Academic Search

Ferrous based materials manufactured by P\\/M method are widely used in industry. These materials are very important no machining and a little by machining can be use for self-lubricated property as journal bearing material, in addition medical etc. applies. In this study, powder metal parts were manufactured from composites ferrous based FeCu -Graphite by P\\/M method particulate reinforced. Fatigue test

Selim Sarper YILMAZ; Remzi VAROL; Celal Bayar; Üniversitesi Gölmarmara

344

Forest decline model development with LANDSAT TM, SPOT, and DEM DATA  

NASA Astrophysics Data System (ADS)

The relationships between percent defoliation and digital near-infrared reflectance data detected by the Landsat thematic mapper and SPOT sensors were investigated. These data were both found to be negatively correlated with defoliation data collected within the boreal montane spruce-fir ecosystem of the Black Mountains, North Carolina. Correlation coefficients were significant at the 0.05 level. Linear regression analysis demonstrated that neither source of satellite-based remotely-sensed data is an accurate predictor of defoliation. The addition of digital elevation data, however, as an independent variable to the regression equations significantly improved the predictive reliability of the models.

Brockhaus, John A.; Campbell, Michael V.; Khorram, Siamak; Bruck, Robert I.; Stallings, Casson

1991-09-01

345

Die operative Behandlung von Skoliosen mit dem „vertical expandable prosthetic titanium rib“ (VEPTR)  

Microsoft Academic Search

Zusammenfassung\\u000a Operationsziel  Das VEPTR-Instrumentarium wurde primär zur Behandlung des Thoraxinsuffizienzsyndroms (TIS) eingesetzt, das mit einer Fusion\\u000a der Rippen und begleitender Skoliose einhergeht. Gleichzeitig wurden auch isolierte kongenitale Skoliosen mit oder ohne Wirbelkörperfehlbildung\\u000a behandelt. Ziel war es, das Thoraxvolumen zu erweitern, die Thoraxsymmetrie wiederherzustellen und die Lungenfunktion zu verbessern.\\u000a Die Thoraxsymmetrie wird mit einer Wachstumslenkung (Distraktion) an der Konkavseite wiederhergestellt. Während des

Cornelius Wimmer; Peter Wallnoefer; Thomas Pfandlsteiner

2010-01-01

346

Toward a simple, DEM-based model for linking channel morphology with Atlantic salmon habitat  

Microsoft Academic Search

Atlantic salmon require swiftwater gravel-bedded rivers for rearing and spawning. Morphology of the rivers in coastal New England and Atlantic Canada is strongly influenced by glacial and land-use history. Longitudinal profiles are characterized by relatively steep (gradient >0.002) and flat (gradient <0.0005) segments, with length scales of several km. This heterogeneity corresponds to strong variations in channel form (boulder cascades,

N. P. Snyder; B. C. Wilkins; J. R. Wright

2008-01-01

347

Intravitreales Triamcinolonacetonid und intraokularer Druck: Vergleich mit dem Partnerauge nach Applikation vehikelfreier Lösung  

Microsoft Academic Search

\\u000a Summary  BACKGROUND: The purpose of this study was to analyze the changes in intraocular pressure (IOP) in both eyes after unilateral\\u000a intravitreal injection of controlled vehicle-removed triamcinolone acetonide (TA). METHODS: In this retrospective study, 87\\u000a patients were treated with intravitreal triamcinolone acetonide (IVTA). Before treatment (4 mg\\/0.05 ml TA), the solution was\\u000a filtered by our pharmacy under sterile conditions. Goldmann applanation

S. Lie; U. Stolba; A. Goll; S. Janowitz; S. Binder

2010-01-01

348

Fünfjährige Erfahrungen mit dem Harrington-Stab bei der operativen Behandlung der Skoliose  

Microsoft Academic Search

We report on our experiences with the operative treatment of scoliosis. In former times we had complications with the curve plaster bandages—caused mainly by the bandage itself or by psychic irritation of the patient—whereas recently, by erection with the Harrington rod, we have complications affecting the lungs or the spinal cord. These are probably caused by the considerable erections that

H. Buchner; P. Pink; H. Reinisch

1974-01-01

349

Forces in piles of granular material: an analytic and 3D DEM study  

Microsoft Academic Search

We investigate the stress distribution at the base of a conical sandpile using both analytic calculations and a three dimensional\\u000a discrete element code. In particular, we study how a minimum in the normal stress can occur under the highest part of the\\u000a sandpile. It is found that piles composed of particles with the same size do not show a minimum

Kurt Liffman; Myhuong Nguyen; Guy Metcalfe; Paul Cleary

2001-01-01

350

Detailed DEM analysis of a rockslide scar to characterize the basal sliding surface of active rockslides  

NASA Astrophysics Data System (ADS)

The basal sliding surfaces in large rockslides are often composed of several surfaces and possess a complex geometry. The exact morphology and location in three dimensions of the sliding surface remains generally unknown, in spite of extensive field and subsurface investigations, such as those at the Åknes rockslide (western Norway). This knowledge is crucial for volume estimations, failure mechanisms, and numerical slope stability modeling. This paper focuses on the geomorphologic characterization of the basal sliding surface of a postglacial rockslide scar in the vicinity of Åknes. This scar displays a stepped basal sliding surface formed by dip slopes of the gneiss foliation linked together by steeply dipping fractures. A detailed characterization of the rockslide scar by means of high-resolution digital elevation models permits statistical parameters of dip angle, spacing, persistence, and roughness of foliation surfaces and step fractures to be obtained. The characteristics are used for stochastic simulations of stepped basal sliding surfaces at the Åknes rockslide. These findings are compared with previous models based on geophysical investigations. This study discusses the investigation of rockslide scars and rock outcrops for a better understanding of potential rockslides. This work identifies possible basal sliding surface locations, which is a valuable input for volume estimates, design and location of monitoring instrumentation, and numerical slope stability modeling.

Oppikofer, Thierry; Jaboyedoff, Michel; Pedrazzini, Andrea; Derron, Marc-Henri; Blikra, Lars Harald

2011-06-01

351

Suitability of LOLA DEMs for Processing TMC Images of Chandrayaan-1  

NASA Astrophysics Data System (ADS)

In this paper, we study the impact of height error in combination with view angle of the TMC cameras on planimetric accuracy. Our study reveals that height errors in LDEM-256 is minimum and is suitable for processing TMC data.

Radhadevi, P. V.; Sudheer Reddy, D.; Saibaba, J.; Varadan, G.

2012-03-01

352

Untersuchungen an Plattfischen und Nordseegarnelen (Crangon crangon) im Eulitoral des Wattenmeeres nach dem Übergang zum Bodenleben  

NASA Astrophysics Data System (ADS)

In spring and early summer, Pleuronectes platessa, Platichthys flesus, Solea solea, and Crangon crangon transform to benthic postlarvae in the shallow water region of the North Frisian Wadden Sea (eastern North Sea). During the first weeks after metamorphosis, they remain in the puddles and drainage gulleys on the tidal flats that are exposed during low tide. Positive rheotaxis prompting the juveniles to swim against the ebb tide currents is an important mechanism for maintaining their position on the flats. When sunlight intensity increases, they continue their locomotory and feeding activity, even during daytime, in the pools still present at low tide. On warm, cloudless days, temperature levels in these pools may increase to lethal thresholds. Consequently, the animals attempt to escape from higher tidal flats near the shore through the drainage gulleys. Such migrations bring about changes in their distribution patterns. Plaice can scarcely be found in near-shore areas, and they are absent at both high and low tide. The responses observed were correlated to physical and chemical data recorded during the observation period. The ecological significance of tidal pools as habitats is discussed.

Berghahn, R.

1983-06-01

353

Zur Differenzierung der Blutbasophilen und Gewebsmastzellen nach dem Reifegrad ihrer Granula  

Microsoft Academic Search

A new modified technique of the Toluidin blue pH-scale is described. Characteristic diagrams show the typical appearance of blood basophils and tissue mast cells. The mast cell granules that appear in the lower part of the pH-scale are regarded as strongly polimerised or sulfated. A far reaching discussion deals with the physicochemical proof of this opinon. The modified Toluidin blue

M. R. Parwabesch; K. Lennert

1969-01-01

354

“…because dem Computer brauchst' es ja nicht zeigen.”*: because + German main clause word order  

Microsoft Academic Search

This paper aims to explain firstly, different frequency distributions of the causal subordinators because and weil in monolingual and bilingual data sets and secondly, verb second, that is, German main clause word order, in clauses introduced by these two conjunctions. Quantitative and quantitative methods will be used. The quantitative study of the mixed German\\/English data reveals almost twice as many

Eva Eppler

2004-01-01

355

Untersuchungen zur Akarizidresistenz an Populationen der Obstbaumspinnmilbe, Panonychus ulmi KOCH (Acari: Tetranychidae) aus dem Bodenseegebiet  

Microsoft Academic Search

Zusammenfassung  Im Obstanbau gehört die Obstbaumspinnmilbe, Panonychus ulmi KOCH (Acari: Tetranychidae), weltweit zu den wichtigsten Schädlingen. Die gezielte Bekämpfung von P. ulmi, die hauptsächlich durch Anwendung von Akariziden erfolgt, dient der Sicherung von Erträgen. Eine hohe Reproduktionsrate, eine sehr kurze Generationsdauer und die häufige Anwendung von Akariziden können zu einer raschen Resistenzentwicklung führen. Um die Wirksamkeit eines Wirkstoffs möglichst dauerhaft zu

Miriam Thiel; Ralf Nauen

2006-01-01

356

Langzeit-Systemvergleiche in Kenia und Indien: Konventionelle und biologische Erträge aus dem ersten Umstellungsjahr  

Microsoft Academic Search

Organic agriculture is more and more perceived as a promising approach to increase food security in developing countries. However, only few attempts have been made so far to assess agronomic and economic performance of organic agriculture in these regions in a systematic way. This article reports the first year's results of two long-term farming systems comparison field trials in Kenya

C. Zundel

357

CFD-DEM Study of Temperature and Concentration Distribution in a Polyethylene Fluidized Bed Reactor  

Microsoft Academic Search

Comprehensive modeling of the gas-phase polyethylene reactor was developed by combining discrete element method (for predicting motion of particulates), Navier-Stokes equation (for predicting velocity fields of gas phase), mass conservation equation (for predicting concentration of reactants), and energy conservation equation (for predicting temperature). A comprehensive kinetic mechanism was used to evaluate the rate of ethylene and 1-butene copolymerization reactions. Simultaneous

Sedigheh Karimi; Zahra Mansourpour; Navid Mostoufi; Rahmat Sotudeh-Gharebagh

2011-01-01

358

Die Ochratoxin A -Belastung ausgewählter Lebensmittel aus dem Blickwinkel der vorgesehenen österreichischen Richtwert-Regelung  

Microsoft Academic Search

\\u000a Abstract  In Austria an index of 3 ?g\\/kg of Ochratoxin A for coffee, 0,3 ?g\\/kg for fruit juices and 0,2 ?g\\/kg for beer is discussed.\\u000a The laboratory of the food inspection authority of the state of Vorarlberg investigated the contribution of selected foodstuffs\\u000a to the daily OTA intake and compared it with the recommendation of the scientific food committee of the

I. Hainschitz; K. Rieger; H. Siegl

2002-01-01

359

Rückenmarksreflexe und afferente Nervenleitung der Katze unter dem Einfluß von Kohlenmonoxyd  

Microsoft Academic Search

Summary The following phenomena have been observed in cats after short exposures to different concentrations (0.159 or 0.051 Vol-%) of carbon monoxide (CO):1.In peripheral afferent nerve fibres there is a decrease of the conduction velocity and of the amplitude of their mass action potential (AP).2.In lightly anesthetized, decerebrated and low spinal animals, during the exposure to the lower concentration (0.051

P. Barrios; W. Koll; G. Malorny

1969-01-01

360

FRANZ KAFKA VE DIE VERWANDLUNG (DE????M)1 ?S?ML? ESER?  

Microsoft Academic Search

The present paper represents a critical effort aimed at discussing the literary contribution of Franz Kafka, a German language Czech writer, in particular his short story Die Verwandlung (Metamorphosis). The first part of the study concentrates on the general considerations about Kafka's life and literary activity, including the major characteristic features of his artistic credo and the basic critical approaches

Z. Aslihan

361

CULTURAL TURN IN DER LITERATURTHEORIE? BEOBACHTUNGEN ZUR NEUAUFLAGE VON IWANAMI LITERARY STUDIES UND DEM \\  

Microsoft Academic Search

Traditional philology in Japan (kokubungaku) is often described, both at home and abroad, as having a phobia of theory. The literary scholar often speaks the same language as the poet, and in many cases, as in the second edition of Iwa- nami Literary Studies (Iwanami K?za Bungaku, 1975-1976), they are one and the same person. However, a closer look at

Robert F. Wittkamp

362

Bestimmung des „verfügbaren” Lysins in Molkenpulver, Molkeneiweiß und labgefälltem Casein mit dem Reaktivfarbstoff Remazolbrillantblau  

Microsoft Academic Search

Summary The available lysine can be determined photometrically after reacting with the active dye Remazolbrillantblau R. It was found by the investigations with whey powder and whey protein powder, that the values of the Remazolbrillantblau R complexes of diverse origin are not directly comparable with one another. The dye-binding proved to be independent of lactose-, glucose- and saccharose content of

H. D. Pruss; K. H. Ney

1972-01-01

363

Estimating Water Storage in Prairie Wetlands from a LiDAR DEM  

NASA Astrophysics Data System (ADS)

The Prairie Pothole Region (PPR) of North America contains millions of wetlands in shallow depressions that have potential to store a significant volume of surface water. Assessing and modeling the effect of wetland storage on streamflow requires accurate methods to quantify wetland water volume. Currently, many methods rely on utilizing the strong statistical relationships between area (A), volume (V), and depth (h) to estimate wetland storage. While V-A equations are commonly used throughout the PPR, equations that utilize the V-A-h relationship are not used extensively because detailed topographic data are required. This paper suggests a new approach for implementing V-A-h relationships to determine wetland volume from wetland characteristics extracted from a high resolution LiDAR digital elevation model. GIS analysis was used to generate elevation contours that represent potential surface areas measurements, as well as provide a measure of the change in area with depth. This data collection process was also automated to generate the necessary input for estimating volume through the V-A-h equations. These volumes were compared to estimates from two V-A equations commonly used in the PPR. Results demonstrate that the automated LiDAR V-A-h method provided a better estimate of wetland volume than the V-A equations. This new method could be useful in quantifying the capacity of prairie pothole wetlands to store water and modeling their role in attenuating streamflows at a variety of spatial scales.

Westbrook, C. J.; Minke, A. G.; Pomeroy, J. W.; Guo, X.

2010-12-01

364

Reconstructing morphometric change in a proglacial landscape using historical aerial photography and automated DEM generation  

Microsoft Academic Search

This paper explores the feasibility of using historical aerial photographs and digital photogrammetric procedures to reconstruct morphometric landscape changes in a proglacial setting of the southern Coast Mountains, British Columbia, Canada. The photographic record includes 12 sets of vertical photography, obtained at a range of large to medium nominal scales, for the period 1947 to 1997. An automated procedure of

Erik Schiefer; Robert Gilbert

2007-01-01

365

Schädelidentifizierung durch Superprojektion nach dem Verfahren der elektronischen Bildmischung, modifiziert zum Trickbild-Differenz-Verfahren  

Microsoft Academic Search

Summary Skull identification by electronic photo-composition can, with the help of a video-animation compositor, be further developed beyond the pure superprojection technique into an animated picture-difference image. The employment of this combined technique is to be recommended on account of the improved possibilities of control to be realized in the congruity of the superprojection composite picture.

R. Helmer; O. Grüner

1977-01-01

366

Structural Analysis of Central Luzon, Philippines, Using Shuttle Radar Topography Mission DEM  

NASA Astrophysics Data System (ADS)

Central Luzon Island (13-16°N, 120-122°E), which is bounded to the east by Philippine Trench, to the west by Manila Trench, to the north by Digdig-Dingalan Fault (DDF) and to the south by Verde Island Passage Fault (VIPF), is one of the most seismically and volcanologically active regions in the Philippines. Active seismicity and violent earthquakes in the region are evidently related to the activities along the subduction zones and branches of the Philippine Fault system. Volcanic eruptions and periodic swarms of volcanic earthquakes were also observed in three active volcanoes, i.e., Pinatubo, Taal Volcano Island and Banahaw, while young calderas of Taal and Laguna de Bay are demonstrably fault-bounded. We use the Shuttle Radar Topography Mission (SRTM) data with 90 m spatial resolution to conduct regional mapping of the faults and volcanic structures in this region. Of particular interests are the NE-SW set of normal faults within the Macolod Corridor, the right-lateral Marikina Valley Fault System (MVFS), the prevalence of N-S trending structures and the series of NW-SE structures that parallel to sub-parallel the active branches of the Philippine Fault. Using ENVI software package, we processed the SRTM data into shaded relief images and examined the lineament features from different azimuth directions and angles of artificial illumination. The prominent NW-SE structures in this area revealed by SRTM data were formed as sinistral shears that parallel the seismically active DDF and VIPF. The N-S trending structures, including some segments of MVFS and N-S oriented fold axes, were apparently generated by an earlier E-W compression, but recently displayed dextral movement with localized vertical component and pull-apart zones. The overprinting of recent fault kinematics on previously formed structures suggest a dramatic shift of regional stress distribution in Central Luzon. The dextral movement along MVFS and the extensional NE-SW faults within the Macolod Corridor are consistent with the regional deformation due to coupling of DDF and VIPF movements. Similarly, the E-W to ENE-WSW and N-S to NNE-SSW structures probably formed as Riedel and anti-Riedel shears.

Torres, R.; Mouginis-Mark, P.; Garbeil, H.; Bautista, L.; Ramos, E.

2002-12-01

367

Die Makrochaeten auf dem Thorax von Calliphora vicina Robineau-Desvoidy (Calliphoridae, Diptera)  

Microsoft Academic Search

\\u000a Summary  Thoracal macrochaetae ofCalliphora were investigated by electron-microscopy during the imaginal and pupal phase. Each sensillum possesses one sensory cell which\\u000a sends off a dendrite to the base of the hair-shaft. A “granular body” is situated in the transitional region between inner\\u000a and outer dendritic segment. During pupal development this region has the structure of a cilium (9×2+0). The dendritic tip,

Thomas Keil

1978-01-01

368

OPTICAL FLOW NAVIGATION FOR AN OUTDOOR UAV USING A WIDE ANGLE MONO CAMERA AND DEM MATCHING  

Microsoft Academic Search

Visual navigation for low altitude unmanned aerial vehicles (UAV) shows many scientific and technical challenges in terms of navigation performances, complex 3D environment, high computational requirements for real-time image processing and very limited onboard mass and power resources. The current paper presents a concept of a visual navigation system, based on a wide angle mono camera as vision sensor and

V. Tchernykh; M. Beck; K. Janschek

369

A Glacier Bed DEM for Jakobshavns Trough as Input for Dynamic Ice Sheet Models  

Microsoft Academic Search

The objective of the paper is to present thoughts on connecting geophysical observations and dynamic ice sheet models. Specifically, surface elevation, bed topography and surface roughness are considered, using observations at several scales. The talk builds on ideas, concepts and results from IceBridge, ICESat, CReSIS, SeaRISE and MICROTOP projects. A specific problem in connecting data and models is that of

B. F. Wallin; U. C. Herzfeld; C. Leuschen

2010-01-01

370

“As Soon as I Get Out Ima Cop Dem Jordans”: The Afterlife of the Corporate Gang  

Microsoft Academic Search

Sudhir Venkatesh and Steven Levitt's influential 2000 article transformed the way social scientists study gangs by showing the context in which Chicago gang members built an organization modeled on a corporation. But if this research helped to demonstrate that the underground economy is a logical response to the inner city's isolation from the rest of the country, it also makes

Laurence Ralph

2010-01-01

371

Die absolute Lotabweichung in Postdam und die Geodätischen ausgangswerte des Gesamteuropäischen netzes auf dem Hayfordschen Ellipsoid  

Microsoft Academic Search

\\u000a Summary  The absolute deviations of the vertical detectable at Potsdam from astronomical-gravity comparisons differ significantly from\\u000a earlier values obtained from the astronomic-geodetic observations which form the starting elements of the European triangulation\\u000a network. It is possible to show, by the use of values of the deviation of the vertical extending over the whole of Europe\\u000a as far as longitude 30°, and

K. Ledersteger

1929-01-01

372

Relationships between volcanic patterns and neotectonics in Eastern Anatolia from analysis of satellite images and DEM  

Microsoft Academic Search

The late Neogene to Quaternary volcanism in Eastern Anatolia is related to the Arabia–Eurasia convergence but a clear deformation pattern has not yet been established in this region. We have used the distribution and shape of volcanoes and fault geometry as indicators of the tectonic regime. Volcanic edifices and related faults were analyzed in vertical view using SAR–ERS, Spot images

Ö. Ad?yaman; J. Chorowicz; O. Kose

1998-01-01

373

DEM simulation of rotation-induced reshaping and disruption of rubble-pile asteroids  

NASA Astrophysics Data System (ADS)

A Soft-Sphere Discrete Element Method (SSDEM) is used to simulate the rotational reshaping and disruption of cohesionless self-gravitating granular aggregates (as a representation of "rubble-pile" asteroids). Aggregates with spherical and ellipsoidal shapes are subjected to impulsive increments of their angular velocity to initiate a reshaping process leading up to the disruption of the aggregate. Internal stress fields are monitored during the process as well as critical angular velocities to initiate reshaping. In addition, the time evolution of other parameters such as filling fraction, angle of friction, mechanical energy, yield stress, semi-axes, density and mass dependence are also analysed. Several predictions from continuum theory are recovered in our simulations, in addition to further insight into the process by which cohesionless rubble piles can deform. Fundamentally different outcomes are found for frictionless grains and grains with surface friction modelled, verifying the importance of including such models in granular simulations. We find that the initiation of shape deformation is most consistently described by a Drucker-Prager failure criterion, which also provides an independent measure of the effective friction angle of our self-gravitating pile. Insight is also gained into the energetics of deformation, with most of the kinetic energy loss going into the deformation of the rubble pile, and a smaller component being internally dissipated. Finally, with this work we want to compare this computational approach with the theoretical predictions and, if possible, to mutually validate them.

Sánchez, Diego Paul; Scheeres, Daniel J.

2012-04-01

374

The Communication Accessibility of the Lunar Rover Based on Lunar DEM Derived from Kaguya/Selene  

NASA Astrophysics Data System (ADS)

The mathematical model can be established to study the communication accessibility affected by topography. Therefore, the Antarctic Great-Wall station is chosen as a deep space tracking station and the feasibility is simulated and analyzed.

Hao, W. F.; Li, F.

2012-03-01

375

Mittelfristige ergebnisse von dorsalen aufrichtungsoperationen juveniler kyphosen mit dem Harrington-instrumentarium  

Microsoft Academic Search

The authors present the results of 20 corrective procedures for juvenile cyphosis using Harrington, compressive rods and Hibbs spondylodesis. 16 procedures date back more than one year (average 3 years, 4 months). 10 cases of pure dorsal cyphosis are compared to 10 cases of dorso-lumbar cyphosis. The pre-operative Cobb-angles for cyphosis averaged 52°, postoperatively an average of 24° was measured.

Peter Griss; Hanns Frhr. Andrian-Werburg

1978-01-01

376

Load Balanced Parallel Simulation of Particle-Fluid DEM-SPH Systems with Moving Boundaries  

Microsoft Academic Search

We propose a new pure Lagrangian method for the parallel load balanced simulation of particle- fluid systems with moving boundaries or free surfaces. Our method is completely meshless and models solid objects as well as the fluid as particles. By an Orthogonal Recursive Bisection we obtain a domain decomposition that is well suited for a controller based load balancing. This

Florian Fleissner; Peter Eberhard

2007-01-01

377

DEM Numerical Simulation of Abrasive Wear Characteristics of a Bioinspired Ridged Surface  

Microsoft Academic Search

This paper presents numerical investigations into a ridged surface whose design is inspired by the geometry of a Farrer's scallop. The objective of the performed research is to assess if the proposed Bioinspired Ridged Surface (BRS) can potentially improve wear resistance of soil-engaging components used in agricultural machinery and to validate numerical simulations performed using software based on the Discrete

Jin Tong; Mohammad Almagzoub Mohammad; Jinbo Zhang; Yunhai Ma; Baojun Rong; Donghui Chen; Carlo Menon

2010-01-01

378

Der Exzellenz-Titel für die kurfürstlichen Gesandten auf dem Westfälischen Friedenskongreß  

Microsoft Academic Search

In this article, Günter Christ discusses the special ceremonial privileges of the ambassadors of the Electors of the Holy Roman Empire at the peace congress which led to the treaties of Westphalia in 1648. The problem is focussed on the right of the ambassador to be accorded the title of Exzellenz, usually reserved for the ambassadors of sovereign states. The

GÜNTER CHRIST

1999-01-01

379

Interne Stellenbesetzung innerhalb der Conergy Gruppe mit dem verhaltensbasierten Fragebogen „Predictive Index“  

Microsoft Academic Search

Die Conergy AG gilt als das umsatzstärkste Solarunternehmen Europas und als weltweiter Marktführer in der solaren Systemintegration.\\u000a Die Unternehmensgruppe verfolgt eine globale Wachstumsstrategie: Für seine Kunden produziert, installiert und projektiert\\u000a der Konzern Solarsysteme oder auch Windkraftanlagen in über 20 Ländern. Die Conergy Gruppe ist inzwischen auf 5 Kontinenten\\u000a mit eigenen Niederlassungen vertreten.

Anja Wurow

380

Dobbertiniopteryx capniomimus gen. et sp. nov. die erste Steinfliege (Insecta: Plecoptera) aus dem europäischen Jura  

Microsoft Academic Search

\\u000a Abstract  From the Upper Liassic of Dobbertin (Mecklenburg, Germany) the first stoneflyDobbertiniopteryx capniomimus gen. et sp. nov. is described. It is probably a representative of the Capniidae (Plecoptera: Nemouroidea) or of its stemgroup.\\u000a Slowly running fresh water streams and stagnant water bodies in coastal regions are considered an ecological cause of the\\u000a rarity of Plecoptera in European Jurassic sediments.

Jörg Ansorge

1993-01-01

381

INTEGRATED DEM AND PAN-SHARPENED SPOT4 IMAGE IN URBAN STUDIES  

Microsoft Academic Search

Digital orthoimages are becoming increasingly of interest as they provide up-to-date information for a wide range of applications. Facing the need for accurate spatial information this paper aims to the production of orthoimages and their further processing, as well as to the three dimensional visualization of the resulting images. The data used are one panchromatic image from Spot-3, with spatial

G. Doxani; A. Stamou

382

Three-dimensional simulation of a solid-liquid flow by the DEM-SPH method  

NASA Astrophysics Data System (ADS)

We develop a new Lagrangian model for solid-liquid flows involving free surfaces.The present model employs conservative forms and a compatible boundary model.We analyze the dynamic wave propagation in a solid-liquid dam-break flow.We simulate the quasi-steady solid-liquid flow in a rotating tank.Simulation results are in good agreement with experimental data for validation.

Sun, Xiaosong; Sakai, Mikio; Yamada, Yoshinori

2013-09-01

383

Nucleus Formation Under the Influence of Electrical Charges (Die Keimbildung Unter dem Einfluss Elektrischer Ladungen).  

National Technical Information Service (NTIS)

Preliminary efforts toward a theory of the Wilson chamber were proven unsatisfactory. Especially, agreement with experiments was lacking, and invalid a priori assumptions had been introduced. A new theory is given that describes the experiments available ...

G. Tohmfor M. Volmer

1974-01-01

384

Auf dem Weg zur individualisierten Medizin - Grid-basierte Services für die EPA der Zukunft  

Microsoft Academic Search

Personalized Medicine is of paramount interest for many areas in Medical Informatics. Therefore genotype data as well a phenotype data about patients have to be available. This data will be stored in Electronic Health Records or – patient controlled - in Personal Health Records. As the amount of (raw) data is rising continuously, methods for a secure data administration have

U. Sax; T. A. Knoch; S. C. Semler; A. Weisbecker; J. Falkner; F. Viezens; Y. Mohammed; M. Hartung; J. Bart; D. Krefting

2007-01-01

385

A DEM-based Watershed Model with Spatial Hortonian Infiltration and Ruh-Off/On  

Technology Transfer Automated Retrieval System (TEKTRAN)

A physically based, distributed rainfall-runoff-runon model was developed for event-based studies of dynamic watershed processes, including space-time patterns of state variables (e.g., soil profile water storage) and fluxes (e.g., overland flow and infiltration). A routing hierarchy for dynamic ru...

386

Simulations of Fracture and Fragmentation of Geologic Materials using Combined FEM/DEM Analysis  

SciTech Connect

Results are presented from a study investigating the effect of explosive and impact loading on geological media using the Livermore Distinct Element Code (LDEC). LDEC was initially developed to simulate tunnels and other structures in jointed rock masses with large numbers of intact polyhedral blocks. However, underground structures in jointed rock subjected to explosive loading can fail due to both rock motion along preexisting interfaces and fracture of the intact rock mass itself. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model these types of problems, we have implemented Cosserat point theory and cohesive element formulations into the current version of LDEC, thereby allowing for dynamic fracture and combined finite element/discrete element simulations. Results of a large-scale LLNL simulation of an explosive shock wave impacting an elaborate underground facility are also discussed. It is confirmed that persistent joints lead to an underestimation of the impact energy needed to fill the tunnel systems with rubble. Non-persistent joint patterns, which are typical of real geologies, inhibit shear within the surrounding rock mass and significantly increase the load required to collapse a tunnel.

Morris, J P; Rubin, M B; Block, G I; Bonner, M P

2005-05-26

387

Integration of SRTM DEM and Hydraulic Analysis for Flood Response Planning  

Microsoft Academic Search

The ability to delineate potential flood inundation areas is one of the most important requirements for flood response planning. Historical hydrologic records and high-resolution topographic data are essential to model flood inundation and to map areas at risk of inundation. For Afghanistan, historical hydrologic data enable the analysis of flood frequency, but the accurate delineation of flood inundation zones is

M. Pervez; K. O. Asante; J. L. Smith; J. P. Verdin; J. Rowland

2006-01-01

388

FEM-DEM simulation of two-way fluid-solid interaction in fibrous porous media  

NASA Astrophysics Data System (ADS)

Fluid flow through particulate media is pivotal in many industrial processes, e.g. in fluidized beds, granular storage, industrial filtration and medical aerosols. Flow in these types of media is inherently complex and challenging to simulate, especially when the particulate phase is mobile. The goals of this paper are twofold: (i) the derivation of accurate correlations for the drag force, taking into account the effect of microstructure, to improve the higher scale macro-models and (ii) incorporating such closures into a ``compatible'' monolithic multi-phase/scale model that uses a (particle-based) Delaunay triangulation (DT) of space as basis - in future, possibly, involving also multiple fields.

Yazdchi, K.; Srivastava, S.; Luding, S.

2013-06-01

389

Multifractal analysis applied to the study of the accuracy of DEM-based stream derivation  

NASA Astrophysics Data System (ADS)

A correct description of river network morphology is very important when it is used to study different features of a river's morphology as well as phenomena related to it, such as erosion, nitrogen retention or sediment pollution. In recent years, different algorithms have been developed to extract drainage networks directly from Digital Elevation Models. In this paper, the suitability of ArcHydro extension, developed for ArcGIS Desktop and based on the D8 algorithm to generate river networks has been studied by using multifractal analysis. The river networks generated by ArcHydro tools were compared to those provided by photogrammetric restitution for different flow accumulation threshold values. One limitation of the D8 algorithm in order to generate the most appropriate river networks is the correct choice of the flow accumulation threshold value. Multifractal analysis has shown itself to be an efficient approach to determine the most suitable flow accumulation threshold values. Moreover, this approach has allowed characterizing the morphology of river networks and testing the quality of ArcHydro results. According to the multifractal spectra, the main difference between the networks considered here is the lesser stream density with a low channel order detected for ArcHydro results compared to photogrammetric restitution. In addition, the relationship between ruggedness number for the largest contributing area and fractal dimensions in each study area has been explored. The use of multifractal analysis has been extended to drainage network simulation going beyond the descriptive aim of previous works.

Ariza-Villaverde, A. B.; Jiménez-Hornero, F. J.; Gutiérrez de Ravé, E.

2013-09-01

390

Effect of DEM Uncertainty on the Positional Accuracy of Airborne Imagery  

Microsoft Academic Search

The geometric and atmospheric processing of air- borne imagery is a complex task that involves many correction steps. Geometric correction is particularly challenging because slight movements of the aircraft and small changes in topogra- phy can have a great impact on the geographic positioning of the processed imagery. This paper focused on how uncertainty in topography, represented by a digital

Johan Beekhuizen; Gerard B. M. Heuvelink; Jan Biesemans; Ils Reusen

2011-01-01

391

Impact force propagation behaviors of rock fall into horizontal granular mat using 2D-DEM  

NASA Astrophysics Data System (ADS)

The effect of a soil mat is to reduce rock-fall energy and impact force. Although the construction costs for soil mats are low, these layers can substantially improve the margin of safety factor. This study examined the performance of a soil mat in reducing rock-fall energy using the discrete element method to investigate the transmission of the impact force in the granulated soil mat caused by rock-fall. The impact force received by a falling body (rock-fall impact force) and the impact force transmitted to the bottom (transmission impact force) due to rock-fall were investigated by examining the effects of particle properties such as hardness, size, and shape, and the soil mat characteristics such as the packing density and layer thickness on the peak impact force. The relationship between the time history of the impact force transmitted to the soil mats with different layer thicknesses and densities and the stress-strain distribution or energy dissipation in the soil mat was also discussed although the results reported here are restricted only to the case of vertical fall.

Maeda, Kenichi; Hashiba, Hirofumi; Karita, Keiichi; Ushiwatari, Yuji; Kawase, Ryoji

392

A regional scale soil mapping approach using integrated AVHRR and DEM data  

Microsoft Academic Search

There is an increasing need for reasonably accurate small-scale soil databases. The compilation of a continental or global-scale soil database requires a lot of spatially and thematically accurate soil data. The aim of this study was to test a method for small-scale soil mapping in Italy using Advanced Very High Resolution Radiometer (AVHRR) and digital elevation data. This method was

Endre Dobos; Luca Montanarella; Thierry Nègre; Erika Micheli

2001-01-01

393

Dynamic simulations of geologic materials using combined FEM/DEM/SPH analysis  

SciTech Connect

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.

Morris, J P; Johnson, S M

2008-03-26

394

"Astronomica" in the Correspondence between Leonhard Euler and Daniel Bernoull (German Title: "Astronomica" im Briefwechsel zwischen Leonhard Euler und Daniel Bernoulli)  

NASA Astrophysics Data System (ADS)

The Euler Commission of the Swiss Academy of Sciences intends to terminate the edition of Leonhard Euler's works in the next year 2011 after nearly one hundred years since the beginning of the editorial works. These works include, e.g., Volume 3 of the Series quarta A which will contain the correspondence between Leonhard Euler (1707-1783) and Daniel Bernoulli (1700-1783) and which is currently being edited by Dr. Emil A. Fellmann (Basel) and Prof. Dr. Gleb K. Mikhailov (Moscow). This correspondence contains more than hundred letters, principally from Daniel Bernoulli to Euler. Parts of this correspondence were published uncommented already in 1843. It is astonishing that, apart from mathematics and physics (mainly mechanics and hydrodynamics), many topics addressed concern astronomy. The major part of the preserved correspondence between Euler and Daniel Bernoulli, in which astronomical themes are discussed, concerns celestial mechanics as the dominant discipline of theoretical astronomy of the eighteenth century. It was triggered and coined mainly by the prize questions of the Paris Academy of Science. In more than two thirds of the letters current problems and questions concerning celestial mechanics of that time are treated, focusing on the lunar theory and the great inequality in the motions of Jupiter and Saturn as special applications of the three body problem. In the remaining letters, problems concerning spherical astronomy are solved and attempts are made to explain certain phenomena in the field of "cosmic physics" concerning astronomical observations.

Verdun, Andreas

2010-12-01

395

An erudite between the worlds: Gottfried Kirch and his visions of the Enlightenment (German Title: Ein Gelehrter zwischen den Welten: Gottfried Kirch und seine aufklärerischen Visionen)  

NASA Astrophysics Data System (ADS)

The calendar literature, until now not held in high esteem by research, had an important share in the dissemination of the enlightenment already in the 1670s. This contentual orientation was especially pronounced in the calendars of Gottfried Kirch. The widely used calendars by Kirch are analyzed in this contribution.

Herbst, Klaus-Dieter

2010-12-01

396

Study of the Reaction Between Methane and Fluorine in Supersonic Free Jets Untersuchung der Reaktion Zwischen Methan und Fluor in Ueberschallfreistrahlen.  

National Technical Information Service (NTIS)

A reactor was developed for studying methane fluorination in the supersonic region. Observed were exothermic exhange reactions between the coaxial injected gas jets and gas dynamic processes and chemical reactions in the combustion flame zone.

H. J. Diesner

1973-01-01

397

Abhängigkeit des Dispersionsgrades der mit RaB bzw. fallout beladenen Aerosolpartikel in der unteren Troposphäre zwischen 700 und 3000 m NN von Luftkörpertyp und Austauschintensität  

Microsoft Academic Search

A double aerosol filter method was used in order to gain relative values which characterize the existing type of size distribution of the atmospheric aerosol particles; labelled by natural or fallout radioactivity. Continuous measurements were carried out simultaneously at 0.7, 1.8 and 3 km altitude since December 1963. Concerning natural (RaB) radioactivity we found the minimum of aerosolparticle size in

Reinhold Reiter

1970-01-01

398

The Astronomische Gesellschaft between international activities and national barriers (1863-1933). (German Title: Die Astronomische Gesellschaft zwischen internationaler Wirksamkeit und nationalen Schranken (1863-1933))  

NASA Astrophysics Data System (ADS)

The Astronomische Gesellschaft (AG), founded in 1863, was always intended to be an international society of astronomers, but it was at the same time always dominated by German astronomers. This is expressed in the national background of the members and in the usage of German as the business language, as well as in other facts. It is shown that this polarity between international activities and national barriers originated in the circumstances of the foundation. Using examples from publications and archival sources, the international activities of the AG and the relation of some members to these are being traced between 1863 and 1933. For this the regulations in the statutes, the activities and the relation to the International Astronomical Union have been analysed.

Dick, Wolfgang R.

399

Anwendung von Methoden der Logistik und Netzplantechnik zur präzedenz- und ressourcenbeschränkten Ablaufplanung von Echtzeitsystemen  

NASA Astrophysics Data System (ADS)

Grundlegende Zusammenhänge zwischen Logistik, Netzplantechnik und Echtzeit sowie den zugehörigen Arten der Ablaufplanung und ihrer Nutzung werden dargestellt. Das Echtzeitprinzip beinhaltet Rechtzeitigkeit von Abläufen, wobei es für eine frühzeitige Beendigung eines Ablaufs keinen Bonus gibt; im Gegensatz zum verspäteten Ablauf, dessen Konsequenzen in der Regel negativ und unabschätzbar sind. Das Just-in-Time-Prinzip gleicht dem der Echtzeit und wird vor allem in der Logistik zur Bezeichnung reibungsloser Abläufe in Beschaffungsketten verwendet. In der Netzplantechnik werden die kritischen Aktivitäten binnen eines Projektes bestimmt, die nicht verzögert werden dürfen, um das Projekt rechtzeitig zu beenden. Außerdem haben die drei Bereiche noch eine Gemeinsamkeit: um realistische Ablaufszenarien darzustellen, müssen in den Analysen auch begrenzte Ressourcen angemessen berücksichtigt werden.

Gumzej, Roman; Lipi?nik, Martin

400

Minimalinvasive endovaskuläre Stent-Therapie bei Erkrankungen in der thorakalen Aorta  

NASA Astrophysics Data System (ADS)

Die Inzidenz der Aortenerkrankungen nimmt aufgrund der Überalterung der Bevölkerung stetig zu und hat sich innerhalb der letzten 20 Jahre von 2,9 auf 10,9 pro 100.000 Einwohner mehr als verdreifacht [1]. Bei Aortenerkrankungen muss zwischen Aneurysmen und Dissektionen unterschieden werden. Der Begriff Aneurysma (Abb. 62.1) bezeichnet die Ausweitung eines arteriellen Blutgefäßes. Sind dabei alle Wandschichten, also innere Schicht (Intima), mittlere Schicht (Media) und äußere Schicht (Adventitia) betroffen, so spricht man von einem echten Aneurysma (Aneurysma verum). Besteht die Aneurysmawand nur aus adventitiellem Gewebe, spricht man von einem falschen Aneurysma. Ursache für ein Aneurysma ist eine Schwächung der elastischen Kräfte der Media, die dann dem intravaskulären Druck nicht mehr standhalten kann.

Voss, Bernhard; Bauernschmitt, Robert; Brockmann, Gernot; Lange, Rüdiger

401

Remark on Groups and Internal Structure in Continuum Mechanics  

NASA Astrophysics Data System (ADS)

Any mechanical motion within a solid is subjected to the group of external motion (Galilean group or if necessary for relativistic mechanics the Lorentz group) and to the internal quasi Lorentz group lq being independent of the external one. Since the effect of the external group always may be simulated by a system of external forces, any internal property is subjected to lq (e.g. quasi masses of defects). The principle of minimal coupling explicitely used in 1969 by KLUGE for mechanical defects within a solid, being extended in 1983 by KADIC and EDELEN by the help of Yang-Mills-theory for introducing phenomenological terms of inertia for mechanical defects, is leading to the relation with the field theoretical masses for defects as in electrodynamics.Translated AbstractBemerkung über Gruppen und innere Struktur der KontiuumsmechanikDie mechanischen Bewegungen eines Festkörpers unterliegen der Gruppe der äußeren Bewegung (der Galileigruppe bzw. für eine relativistische Mechanik der Lorentzgruppe) sowie der davon unabhängigen inneren quasi Lorentzgruppe lq. Da sich der Einfluß der äußeren Gruppe immer durch ein System äußerer Kräfte simulieren läßt, unterliegen die inneren Eigenschaften der Gruppe lq (z. B. Quasimassen der Defekte). Das durch KLUGE 1969 auf die Strukturdefekte des Festkörpers übertragene Prinzip der minimalen Kopplung, was durch KADI? und EDELEN 1983 im Rahmen des Yang-Mills-Formalismus durch Einführung phenomenologischer Trägheitsterme für die Defekte erweitert wurde, führt auf die Frage nach dem Zusammenhang mit den feldtheoretischen Massen der Defekte in Analogie zur Elektrodynamik.

Günther, H.

402

The trend analysis of land use degradation in Beijing surrounding area using TM data and high resolution DEM  

Microsoft Academic Search

The indulge persecution of sandstorm had attracted great attention of many countries around the world. Chinese government and the Chinese academy of science going with some other countries have devoted a large amount of vigor to study the crucial environment problem. Following the study development, an international cooperation organization has been established to clarify the produce mechanism, transfer process and

Shuang Li; Yunqiang Zhu; Juanle Wang

2005-01-01

403

DEM and GIS analysis of geomorphic indices for evaluating recent uplift of the northeastern margin of the Tibetan Plateau, China  

NASA Astrophysics Data System (ADS)

The northeastern margin of the Tibetan Plateau is a tectonically active region consisting of a series of faults with bounded intermountain basins and is located in the transition zone between the Tibetan Plateau and the Loess Plateau. Active deformation that may affect the topography in this region can be quantified using geomorphic indices. Therefore, we applied geomorphic indices such as the hypsometric integral and the stream length gradient index to infer neo-tectonics in the northeastern margin of the Tibetan Plateau. Different time-scaled geodetic leveling data and river incision rates were also integrated into the investigation. The results show that the hypsometric integrals are not significantly affected by lithology but spatially correspond to the hanging walls of thrust faults. The hypsometric integrals are also positively correlated with the leveling data. Although the stream length gradient index is influenced by lithology, its most pronounced anomalies of the stream length gradient are associated with the thrust faults. Consequently, the uplift in the northeast margin of the Tibetan Plateau appeared to be concentrated along the hanging walls of the thrust faults.

Gao, Mingxing; Zeilinger, Gerold; Xu, Xiwei; Wang, Qingliang; Hao, Ming

2013-05-01

404

OPTIMISATION OF PROCESS FLOW FOR HIGH RESOLUTION DEM GENERATION VIA DIGITAL PHOTOGRAMMETRY: TEST OF OPTIONS WITH AND WITHOUT ANCILLARY DATA  

Microsoft Academic Search

Casey City, (eastern suburban Melbourne) is formulating the Cranbourne West and Lyndhurst Development Plan. The somewhat irregularly-shaped site (approximately 1618 hectares) lies between Western Port Highway to the west, Cranbourne-Frankston Road to the south - Evans Road to the east - South Gippsland Highway to the north. Pre- requisite to later stages of project formulation and execution is possession of

Joshphar Kunapo; Shobhit Chandra; Jim Peterson; Cathy Brady

405

The discrete equation method (DEM) for fully compressible, two-phase flows in ducts of spatially varying cross-section  

Microsoft Academic Search

For the simulation of light water nuclear reactor coolant flows, general two-phase models (valid for all volume fractions) have been generally used which, while allowing for velocity disequilibrium, normally force pressure equilibrium between the phases (see, for example, the numerous models of this type described in (Städtke, 2006)). These equations are not hyperbolic, their physical wave dynamics are incorrect, and

Ray A. Berry; Richard Saurel; Olivier LeMetayer

2010-01-01

406

Characterization of the Sediment Routing System of the Argentine Las Peñas Thrust From ASTER Imagery Interpretation and DEM Terrain Analysis  

Microsoft Academic Search

In an arid region north of Mendoza, Argentina active structures of the Precordilleran fold and thrust belt control sedimentation in the proximal Andean foreland basin. Initiation of new thrust faults and along-strike growth of fault-propagation folds drives uplift of hanging-wall source areas. Drainage basin initiation and development in the Las Peñas thrust hanging-wall triggers erosion of sediment, controlling transport and

I. S. Abrahamson; J. Schmitt

2009-01-01

407

Eine sensible Komplementbindungsreaktion (KBR) zum Nachweis des Au\\/SH-Antigens und ihr Vergleich mit dem Agargeltest und der Gegenstromelektrophorese  

Microsoft Academic Search

Summary Some parameters of Au\\/SH antigen micro CFT were investigated: dependance of maximum titer on complement dosis, incubation time and temperature; kinetics of the complement fixing antigen-antibody-reaction at +4°C; characterisation of the antigen-antibody-reaction in the two-dimensional CFT on the basis of the 50% hemolysis (isofixation curves); comparison of antigens of different concentration by means of the isofixation technique. The highest

J.-F. Kapp; P. G. Höher; E. Kuwert; O. Thraenhart; D. Paar; W. Hengstebeck; H.-J. Roggenbach

1971-01-01

408

Resolving the H UPD and H OPD by DEMS to determine the ECSA of Pt electrodes in PEM fuel cells  

Microsoft Academic Search

Overpotential deposited hydrogen (HOPD) and underpotential deposited hydrogen (HUPD) are produced together on Pt in acidic media between 0 and 110mV vs. SHE and cannot be resolved by cyclic voltammetry alone. Differential electrochemical mass spectrometry was demonstrated for the first time to resolve HOPD and HUPD by measuring the H2 evolved from water by the hydrogen evolution reaction at the

Wei Li

2011-01-01

409

Konsensusdokument des 2. Europäischen Workshops über die Prävention und den Ausstieg aus dem Tabakkonsum für das zahnmedizinische Praxisteam  

Microsoft Academic Search

\\u000a Summary  Tobacco use has been identified as a major risk factor for oral disorders such as cancer and periodontal disease. Tobacco\\u000a use cessation (TUC), on the other hand, is associated with the potential for reversal of precancer, enhanced outcomes following\\u000a periodontal treatment, and better periodontal status compared to patients who continue to smoke. Consequently, helping tobacco\\u000a users to quit has become

Christoph A. Ramseier; Saman Warnakulasuriya; Ian G. Needleman; Jennifer E. Gallagher; Aira Lahtinen

2010-01-01

410

Imaging spectroscopy with AIA: using AIA diffraction patterns to probe flare DEM curves in conjunction with RHESSI and EVE spectra  

NASA Astrophysics Data System (ADS)

Here we present an innovative use of AIA data, utilizing diffraction and dispersion artifacts to preform imaging spectroscopy with AIA. Using this technique, we probe the time and spatial dependence of emission measure distributions in a compact flare. This is achieved through comparison of AIA dispersion spectra to EVE and CHIANTI spectra. In this way, we can no only probe the original spectral components of the flare emission but we can achieve this with the cadence and spatial resolution of AIA. To further extend the dataset, RHESSI spectral results are included and, in a break from tradition, RHESSI images are used to place AIA spectra in context. Unlike traditional spectroscopic methods, imaging spectroscopy with AIA allows us to capture the highly dynamic nature of flares with no compromise for spatial resolution or cadence.

Raftery, C. L.; Krucker, S.

2011-12-01

411

Terrain Classification of Aster gDEM for Seismic Microzonation of Port-Au Haiti, Using - and - Based Analytic Methods  

Microsoft Academic Search

The aftermath of the M7.0 Haiti earthquake of 12 January 2010 witnessed an impressive scientific response from the international community. In addition to conventional post-earthquake investigations, there was also an unprecedented reliance on remote-sensing technologies for scientific investigation and damage assessment. These technologies include sensors from both aerial and space-borne observational platforms. As part of the Haiti earthquake response and

A. Yong; S. E. Hough; B. R. Cox; E. M. Rathje; J. Bachhuber; D. Hulslander; L. Christiansen; M. Abrams

2010-01-01

412

PeliGRIFF, a parallel DEM-DLM\\/FD direct numerical simulation tool for 3D particulate flows  

Microsoft Academic Search

The problem of particulate flows at moderate to high concentration and finite Reynolds number is addressed by parallel direct\\u000a numerical simulation. The present contribution is an extension of the work published in Computers & Fluids 38:1608 (2009), where systems of moderate size in a 2D geometry were examined. At the numerical level, the suggested method is inspired\\u000a by the framework

Anthony Wachs

413

Using Distinct-Element Method (DEM) to Investigate Tsaoling Landslide Induced by Chi-Chi Earthquake, Taiwan.  

NASA Astrophysics Data System (ADS)

Large landslides occurred in the mountainous area near the epicenter on Sept. 21st, 1999, Chi-Chi earthquake in central Taiwan. These landslides were triggered by the Mw = 7.6 earthquake, which resulted in more than 2,400 people casualties and widespread damage. The 1999 Chi-Chi earthquake triggered a catastrophic Tsaloing landslide, which mobilized about 0.125 km3 of rock and soil that slid across the Chingshui River and created a 5 km long natural dam. One fifth of the landslide mass dropped into the Chingshui River, the rest crossed over Chingshui River. At least five large landslides occurred in Tsaoling area are induced by big earthquakes and downpours since 1862 to 1999. Geological investigation shows that the prevailing attitude of sedimentary formation is about N50W with a dipping angle of 12S. First we used Newmark Method to calculate the stability of slope distinct-element method to simulate Tsaoling landslide (PFC3d and PFC2d discrete element code). Because of the discrete, particle-based nature of the model, specification of material properties and boundary condition is more difficult than available continuum methods. The user may specify micro-properties that control particle-particle interaction, but have no way to directly prescribe the micro-properties of the model such as Young's modulus(E), unconfined compressive strength (UCS), Cohesion(C0), Possion's ratio(£h), coefficient of friction(£g), porosity, and the initial stress state. As a result, the process of generating an initial model with the appropriate material behavior and initial stress state is by trial-and-error, requiring the use of numerical equivalent of a biaxial rock mechanics test rig to derive the rock mechanical macro-properties. We conclude that the characteristics of Tsaoling landslide process are: (1) the rocks were bond together on sliding, and (2) the frictional coefficient was very small.

Tang, C.; Hu, J.; Lin, M.

2006-12-01

414

Cervicale Oesophagusperforation nach ventraler Fusion der HalswirbelsäuleDefektdeckung durch Muskelplastik mit dem Musculus sternocleidomastoideus: Fallbericht und Literaturübersicht  

Microsoft Academic Search

\\u000a Summary.   The therapy for spontaneous or artificial perforation of the esophagus remains a controversial matter. The following case\\u000a report deals with the medical history of an artificial esophageal perforation after operative treatment of cervical disc disease.\\u000a A 68-year-old male patient underwent a C4\\/C5 and C5\\/C6 discectomy with interbody fusion of C7-T1 vertebral body, according\\u000a to Smith-Robinson. During this operation, a

P. Lamesch; H. Dralle; M. Blauth; J. Hauss; H. J. Meyer

1997-01-01

415

Zuverlässigkeit des Heimmonitorings am Beispiel des Gerätes Nellcor Puritan Bennett Assurance A4000 kombiniert mit dem Pulsoximeter NPB 290  

Microsoft Academic Search

Question of the study  The realiable recognition of hypoxemia as well as apnea, bradycardia, tachycardia is necessary for the sufficient quality of home monitoring. There are some commercially available cardiorespiratory home monitors that have not been evaluated with complete polysomnographic studies. The purpose of this study was to determine the reliability of the home monitoring system Nellcor Puritan Bennett Assurance A4000

Olga Siratska; Ekkehart Paditz; Ursula Range

2000-01-01

416

The Lower Feale pumps experiment: Development of a high resolution 3-dimensional hydrological model integrated with high resolution DEM  

Microsoft Academic Search

The lower Feale catchment is a low-lying peaty area of 200 km^2 situated in southwest Ireland. Floods heavily affect this area. There are a total of 15 polders in the catchment. Each polder can be considered as hydraulically independent. A previous study examined various solutions for flood alleviation. A network of pumps is considered to be the best possible solution.

L. Migliori; R. H. Cuenca; J. P. O Kane; J. Martin

2003-01-01

417

Suche nach dem Higgs-Boson in hadronischen Endzuständen mit fehlender Energie am L3Experiment bei LEP  

Microsoft Academic Search

This thesis presents searches for the Higgs boson, which is predicted by the Standard Model of Particle Physics and its extensions in order to endow fermions and bosons with their observed masses. While the Standard Model predicts only one Higgs boson »H«, the Minimal Supersymmetric Extension contains five Higgs bosons. This analysis refers to the light neutral »h«, which has

Marc Henning Zöller

2005-01-01

418

Impact of DEM mesh size and soil map scale on SWAT runoff, sediment, and NO 3–N loads predictions  

Microsoft Academic Search

The accuracy of agricultural nonpoint source pollution models depends to a great extent on how well model input spatial parameters describe the relevant characteristics of the watershed. It is assumed that reducing the precision of spatial input parameters affects the simulation results of runoff and sediment yield from the entire watershed. However, there may be no significant increase in the

V. Chaplot

2005-01-01

419

Effects of anisotropy in permeability on the two-phase flow and heat transfer in a porous cavity  

NASA Astrophysics Data System (ADS)

Zusammenfassung In der Arbeit wird über die Ergebnisse einer numerischen Studie, betreffend die stationäre Konvektionsströmung und den stationären Wärmeübergang in einer rechteckigen, mit einem porösen, phasenveränderlichen Medium (PCM) verfüllten Kavität, berichtet. Den zwei vertikalen Berandungen der Kavität sind zwei, den Schmelzpunkt des PCM einschließende Temperaturen aufgeprägt, während die beiden horizontalen Berandungen adiabat gehalten werden. Das poröse Medium ist durch einen anisotropen Permeabilitätstensor charakterisiert, dessen Hauptachsen bezüglich des Gravitationsvektors beliebig orientiert sein können. Das Problem ist durch das Seitenverhältnis A, die Rayleigh-Zahl Ra, das Anisotropienverhältnis R und den Orientierungswinkel ? des Permeabilitätstensor bestimmt. Hauptaugenmerk gilt dem Einfluß der anisotropen Permeabilität auf das Strömungsverhalten und den Wärme-übergang beim Phasenwechselprozeß flüssig/fest. Die Lösungsmethode basiert auf dem Kontrollvolumenprinzip in Verbindung mit der Landau-Transformation über welche das irreguläre Strömungsgebiet in ein rechteckiges abgebildet wird. Ergebnisse bezüglich Strömungsfeld, Temperaturverteilung, Phasengrenzenort und Wärmeübergang werden fürA=2,5Ra=40 0<=?<=? 0,25<=R<=4 mitgeteilt. Es zeigte sich, daß der Gleichgewichtszustand des Phasenwechselsprozesses fest/flüssig sowohl durch das Anisotropieverhältnis R als auch durch den Orientierungswinkel ? des Permeabilitätstensors wesentlich beeinflußt werden kann. Zum einen existiert bei festgehaltenen ParameternA, Ra undR eine optimale Orientierung ?max, bei der die Stromstärke, das Flüssigkeitsvolumen und der Wärmestrom Maximalwerte erreichen, während für ?min=?max+?/2 Minimalwerte resultieren. Ist das anisotrope Medium entlang der Optimalrichtung ?max orientiert, so ergibt sich zum anderen, daß eine Vergrößerung der in diese Richtung fallenden Permeabilitätskomponente die Stromstärke und den Wärmestrom in gleichem Maße erhöht, während eine Vergrößerung der anderen Permeabilitätskomponente nur vernachlässigbaren Einfluß hat. In den untersuchten Parameterbereichen lag die Optimalrichtung zwischen dem Gravitationsvektor und der Hauptstromrichtung.

Zhang, X. L.; Nguyen, T. Hung; Kahawita, R.

420

The controversy between Alexander Friedmann and Albert Einstein about the possibility of a non-static world (German Title: Die Kontroverse zwischen Alexander Friedmann und Albert Einstein um die Möglichkeit einer nichtstatischen Welt)  

Microsoft Academic Search

Einstein's treatment of the cosmological problem as well as his unshakeable adherence to his own static solution of the complete field equations was throughout determined by Ernst Mach's idea of relativity of inertia. Friedmann, however, like Eddington, Weyl and others did not consider Mach's principle to be a part of general relativity, and so he regarded a time dependent developing

Georg Singer

2005-01-01

421

Diglossische Prozesse (Zwischen Deutsch und Spanisch) unter den Spanischen Emigranten der 2. Generation in Deutschland: Eine Soziolinguistische Studie (Diglossia Processes (Between German and Spanish) Among Second Generation Spanish Immigrants in Germany: A Sociolinguistic Study).  

ERIC Educational Resources Information Center

Presents a sociolinguistic study of second-generation Spanish immigrants in Germany. Specific focus is on "diglossia processes," or how Spanish and German are used for different sociolinguistic situations. (Author/VL)

Sanchez, Karin Vilar

1998-01-01

422

Die allgemeine Terminologielehre--ein Grenzgebiet zwischen Sprachwissenschaft, Logik, Ontologie, Informatik und den Sachwissenschaften (The Theory of General Terminology--An Intersection of Linguistics, Logic, Ontology, Information Science, and the Technical Sciences)  

ERIC Educational Resources Information Center

Expanded version of a lecture held at the University of Vienna, May 25, 1972, and in shorter form at the Third International Congress for Applied Linguistics, Copenhagen, Denmark, August 22, 1972. (DD)

Wuster, Eugen

1974-01-01

423

On the Scientific Relationships in Plant Protection Research Between Institutes in the Soviet Union and in the German Democratic Republic. (Ueber die Wissenschaftlichen Bezichungen in der Pflanzenschutzforschung Zwischen Instituten in de Sowjotunion und der Deutschen Demokratischen Republik).  

National Technical Information Service (NTIS)

The USSR and East Germany re-established the scientific relations pertaining to questions of plant protection shortly after the end of World War II. The close collaboration of scientists in Soviet and German agencies was motivated by the need to secure ad...

1968-01-01

424

Zwischen den Stuhlen: Untersuchungen zur Situation der Korrektoren an der Fernuniversitat 1980, (In between Chairs: The Situation of Tutors (Correctors) at the FernUniversitat in 1980). ZIFF Papiere 34.  

ERIC Educational Resources Information Center

|An empirical study of tutors responsible for evaluating students' assignments at the Fernuniversitat in 1980 employed an 18-item questionnaire, analysis of open-ended responses, analysis of graders' comments on more than 1,000 assignments, and interviews with staff. The process of evaluating students' work was shown to be inefficient, with…

Fritsch, Helmut; And Others

425

Einfluss der Gezeitenreibung Zwischen Galaxien Auf die Bildung und Entwicklung von Galaxienhaufen im Expandierenden Universum (Effect of Tidal Friction Between Galaxies on the Formation and Development of Galactic Clusters in the Expanding Universe).  

National Technical Information Service (NTIS)

The formation and development of galactic clusters in Euclidean expanding universes were investigated using N-body simulation calculations. The dynamics of the galaxies were described by a continuously acting interaction term which takes into account grav...

P. Schwekendiek

1988-01-01

426

3D initial sediment distribution and quantification of mass balances of an artificially-created hydrological catchment based on DEMs from aerial photographs using GOCAD  

Microsoft Academic Search

The spatial distribution and properties of parent material components form the starting point for any soil and ecosystem. Initial phases of ecosystem development are predominantly characterized by the redistribution of sediment components. To improve the understanding of soil-landscape development, the initial sediments need to be quantified in space and time. This study aims at developing and testing methods for the

Anna Schneider; Horst H. Gerke; Thomas Maurer

2011-01-01

427

Klinikum und Fachbereich Medizin Johann Wolfgang Goethe-Universität Frankfurt am Main Immunescape-Mechanismen von Borrelia burgdorferi, dem Erreger der Lyme Borreliose  

Microsoft Academic Search

Um der bakteriolytischen Wirkung von Komplement zu entgehen, sind ausschließlich serum-resistente Borrelienisolate in der Lage, die Komplementregulatoren Faktor H, FHL-1 und FHR-1 zu binden. Diese Interaktion mit wirtsspezifischen Proteinen führt dazu, dass die zuvor eingeleitete Komplementaktivierung direkt auf der Erregeroberfläche kontrolliert wird und schlußendlich zum Erliegen kommt (Abb.). Als primäre Liganden für die Komplementregulatoren konnten in den letzten Jahren verschiedene

Peter Kraiczy

428

German Strategy and Public Opinion After the Wall, 1990-1993 (Deutsche strategie und oeffentliche meinung nach dem fall der mauer, 1990-1993).  

National Technical Information Service (NTIS)

In the fall of 1990, RAND initiated a multiyear survey to explore how trends in German public opinion could reshape German strategic thinking over the next decade. The purpose of these studies was to address a simple question: How will Germans define thei...

R. D. Asmus

1994-01-01

429

Mehrachsige Ermuedungsversuche an Rohrproben aus dem austenitischen Stahl 1.4909. (Multiaxial fatigue tests on 1.4909 austenitic steel tubes).  

National Technical Information Service (NTIS)

In this work a newly developed test rig for multiaxial isothermal fatigue tests on steel tubes is presented. The multiaxial load is composed of a cyclic axial load (tension/compression) and a superimposed circumferential load (internal/external pressure)....

B. Windelband

1996-01-01

430

Auswirkungen des K + -Kanalblockers Tedisamil auf Hämodynamik, Myokardischämie und neurohumorales System bei Patienten mit stabiler Angina pectoris.¶Ein Vergleich mit dem ß-Blocker Atenolol  

Microsoft Academic Search

Summary Background: Clinical drawbacks of beta-blocker treatment in stable angina have motivated researchers to provide alternative heart rat lowering agents, such as tedisamil which additionally exerts antiischemic and antiarrhythmic effects by blockade of cellular repolarizing K+ currents. Methods and Results: 48 patients with stable angina pectoris were investigated (double-blind, randomized, parallel grouped) comparing the hemodynamic, antiischemic, metabolic and neurohumoral effects

V. Mitrovic; A. Miskovic; M. Straub; K. Beckmann; J. Thormann; H. Pitschner

1999-01-01

431

Airborne and spaceborne DEM- and laser altimetry-derived surface elevation and volume changes of the Bering Glacier system, Alaska, USA, and Yukon, Canada, 1972-2006  

NASA Astrophysics Data System (ADS)

Using airborne and spaceborne high-resolution digital elevation models and laser altimetry, we present estimates of interannual and multi-decadal surface elevation changes on the Bering Glacier system, Alaska, USA, and Yukon, Canada, from 1972 to 2006. We find: (1) the rate of lowering during 1972-95 was 0.9±0.1 m a-1; (2) this rate accelerated to 3.0±0.7 m a-1 during 1995-2000; and (3) during 2000-03 the lowering rate was 1.5±0.4 m a-1. From 1972 to 2003, 70% of the area of the system experienced a volume loss of 191±17 km3, which was an area-average surface elevation lowering of 1.7±0.2 m a-1. From November 2004 to November 2006, surface elevations across Bering Glacier, from McIntosh Peak on the south to Waxell Ridge on the north, rose as much as 53 m. Up-glacier on Bagley Ice Valley about 10 km east of Juniper Island nunatak, surface elevations lowered as much as 28 m from October 2003 to October 2006. NASA Terra/MODIS observations from May to September 2006 indicated muddy outburst floods from the Bering terminus into Vitus Lake. This suggests basal-englacial hydrologic storage changes were a contributing factor in the surface elevation changes in the fall of 2006.

Muskett, Reginald R.; Lingle, Craig S.; Sauber, Jeanne M.; Post, Austin S.; Tangborn, Wendell V.; Rabus, Bernhard T.; Echelmeyer, Keith A.

432

Suche nach dem Einfluß der chemischen Bindung auf die Halbwertszeit des 90 m Nb ( T 1\\/2 =19,2 sec)  

Microsoft Academic Search

90mNb was produced by the reaction90Zr(d, 2n). Comparison of its half-lives in two different chemical environments (Nb atoms in metallic Zr and in the niobium-fluoride complex) showed no difference greater than the experimental error of 1%, whileCooper et al. have reported that the half-life of90mNb nuclei is shorter by 3.6% in metallic Nb than in the niobium-fluoride complex. — In

W. Weirauch; W.-D. Schmidt-Ott; F. Smend; A. Flammersfeld

1968-01-01

433

Über Grenzen schreiben Presseberichterstattung zu Themen aus dem Bereich der Anomalistik und der Grenzgebiete der Psychologie in den Printmedien SPIEGEL, BILD und BILD AM SONNTAG  

Microsoft Academic Search

BILD and SPIEGEL are probably the two most influential print media in the Federal Republic of Germany since the 1950ies. Analysed is the frequency, contents and style of 2422 reports in BILD and SPIEGEL on 46 different topics of anomalistics and the border areas of psychology (e.g. astrology, cults, hypnosis, parapsychology, poltergeists, UFOs etc) for a period of five decades.

GERHARD MAYER

434

Construction of Yeywa Hydropower Project in Myanmar - Focus on RCC Technology Bauausführung der Yeywa Wasserkraftanlage in Myanmar mit dem Schwerpunkt Walzbeton-Technik  

Microsoft Academic Search

The Yeywa HEP (790 MW) is under construction at present in Myanmar. The RCC dam, first of its type in the country, is a 134 m high straight-gravity structure and has a total volume of 2.5 million m 3 . The construction was planned already during the design stage and a comprehensive training programme has been developed with the local

435

Multi-risk interpretation of natural hazards for settlements of the Hatay province in the east Mediterranean region, Turkey using SRTM DEM  

Microsoft Academic Search

Many scientists have recently alarmed natural hazards due to global climate change. Such natural disasters are coastal inundation\\u000a in response to sea-level rise, and\\/or river flooding caused by heavy rain falls, additionally earthquakes and, etc. In terms\\u000a of natural hazards, one of the most sensitive and culturally significant areas in Turkey is the Hatay province in the east\\u000a Mediterranean region.

A. C. Demirkesen

436

Automatic Field Recording of Vapor Pressure of Soil Moisture with the Pressure Transducer Tensiometer (Automatische Registrierung der Bodenwasserspannung im Gelande mit dem Druckaufnehmer-Tensiometer).  

National Technical Information Service (NTIS)

From testing a pressure transducer-tensiometer for automatic recording of soil-moisture suction in the field the following conclusions were drawn: (1) The resolution is plus or minus 1 cm WS, due to high zero stability and low thermal shift; the response ...

O. Strebel W. Giesel M. Renger S. Lorch

1976-01-01

437

Up Close and Personal – The Interplay between Information Technology and Human Agency in the Policing of the 2011 Sheffield Anti-Lib Dem Protest  

Microsoft Academic Search

\\u000a This chapter constitutes a case study of South Yorkshire Police’s (SYP’s) handling of a protest outside the Sheffield City\\u000a Hall venue of a Liberal Democrat party conference on 11-12 March 2011. The demonstration occurred in the wake of a number\\u000a of high-profile official reports advocating a more permissive approach to protest policing. The chapter describes and analyses\\u000a two particular aspects

Kerry McSeveny; David Waddington

438

Usefulness of synthetic aperture radar (SAR) interferometry for digital elevation model (DEM) generation and estimation of land surface displacement in Jharia coal field area  

Microsoft Academic Search

Land surface displacement is a phenomenon of ground movement, which may occur due to various reasons including unplanned mining. The quantification of land surface displacement through conventional field surveys is based on sparingly distributed point data, which may be insufficient for many applications. A detailed spatial and temporal monitoring of land surface displacements through remote sensing-based synthetic aperture radar (SAR)

Atanu Bhattacharya; Manoj K. Arora; Mukat L. Sharma

2011-01-01

439

Usefulness of synthetic aperture radar (SAR) interferometry for digital elevation model (DEM) generation and estimation of land surface displacement in Jharia coal field area  

Microsoft Academic Search

Land surface displacement is a phenomenon of ground movement, which may occur due to various reasons including unplanned mining. The quantification of land surface displacement through conventional field surveys is based on sparingly distributed point data, which may be insufficient for many applications. A detailed spatial and temporal monitoring of land surface displacements through remote sensing-based synthetic aperture radar (SAR)

Atanu Bhattacharya; Manoj K. Arora; Mukat L. Sharma

2012-01-01

440

Industrieroboter im Automobilbau-auf dem Sprung zum 'automatisierten Fordismus'. (Industrial robots in car construction-on the way to 'automized Fordism').  

National Technical Information Service (NTIS)

Since the end of the 70s international car manufacturers have adopted a new strategy with regard to the use of robots. Companies all over the world - headed by the Japanese car makers - decided not to 'dabble' with industrial robots anymore but to 'blockb...

T. Malsch K. Dohse U. Juergens

1984-01-01

441

DEM-based reconstruction of southern Basse-Terre volcanoes (Guadeloupe archipelago, FWI): Contribution to the Lesser Antilles Arc construction rates and magma production  

NASA Astrophysics Data System (ADS)

We combine radiometric ages and geomorphologic investigations to quantify the relief creation of well preserved volcanic surfaces, applied to the volcanoes of southern Basse-Terre (Guadeloupe, Lesser Antilles Arc). The last 650 ka volcanic evolution of this island has been modeled using ten main stages constrained by K-Ar ages previously obtained on lava flows and domes from the volcanic massifs of the Axial Chain (1000-435 ka) and from the Grande Découverte Volcanic Complex (250 ka-present). Based on the construction of a 250,000-point database inferred from the analysis of the Guadeloupe Digital Elevation Model, 3D reconstructions of the successive volcanic stage landforms were calculated and the correlated geochronological maps drawn using ArcGIS software. Volumes and rates of construction were computed for each time span separating these ten stages. The average construction rates calculated here are 2.4 ± 0.3 × 10-4 km3/yr for the last million years, 0.9 ± 0.3 × 10-4 km3/yr for the last 100 ka, and 0.9 ± 0.2 × 10-4 km3/yr for the last 15 ka. Although Basse-Terre volcanism is characterized by a marked dominance of effusive products, our estimates should be considered as minimum values because the material that went into the sea during explosive events was not taken into account. However, we note that a relatively high construction rate of 4.5 ± 1.3 × 10-4 km3/yr has been obtained for the Icaques volcano, which was emplaced during the 630-600 ka time interval, within the depression formed by the first large-scale flank collapse having affected southern Basse-Terre. The sudden release of the lithostatic load induced by this mass-wasting event could explain this value, which is significantly higher than the average value of 0.8 ± 0.1 × 10-4 km3/yr obtained for the last 650 ka. Finally, the comparison with other analogous volcanic massifs from islands and continental arcs points to a relatively low magmatic production for southern Basse-Terre, which could be tentatively related to the relatively slow subduction rate of the Atlantic plate.

Lahitte, Pierre; Samper, Agnès; Quidelleur, Xavier

2012-01-01

442

Zum screening der benzo- und thienodiazepine im urin mit dem emit ST und der DC im rahmen eines suchtestes auf medikamentenmißbrauch  

Microsoft Academic Search

All 24 Benzo- and Thienodiazepines which are used in drugs in the FRG were added to drug free urine in different concentrations and examined by Emit ST as well as by TLC. In addition the acid hydrolysis products of diazepines were analysed by TLC. A modification of the extraction procedure is described, which shortens analysis time considerably. The detection limits

H. Gruhl

1987-01-01

443

Deutsch-chinesische Kooperation auf dem Gebiet der Wind- und Sonnenenergie. Abschlussbericht. (German-Chinese cooperation in the field of wind and solar energy. Final report).  

National Technical Information Service (NTIS)

The report reviews the German-Chinese cooperation in the field of wind power. The project comprised the following tasks: Establishment of a testing and tracing center; supply of measuring instruments; training of staff for wind purer systems; servicing of...

C. Nath

1992-01-01

444

Zuechtung von GaAs-Einkristallen Nach Dem Floating-Zone-Verfahren Unter Microgravity (Growing of GaAs Monocrystals after the Floating Zone Process under Microgravity).  

National Technical Information Service (NTIS)

GaAs as a semiconductor material, is gaining importance in the field of opto-electronics and very rapid microelectronic circuits. Therefore, requirements for purity and homogeneity are higher, and crystal growth processes must to be improved. The advantag...

F. M. Herrmann

1990-01-01

445

Difficulties During the Barometic Discharging of Liquids from the Vacuum by Means of Gravity Tubes Schwierigkeiten Beim Barometrischen Ausschleusen von Fluessigkeiten Aus Dem Vakuum Mittels Fallrohren.  

National Technical Information Service (NTIS)

The barometric discharging of liquid, used to cool rocket exhaust gases by means of gravity tubes, and its efficiency improvement by means of an air vent, is discussed. This cooling system is used at rocket test stands, and the cooling of the exhaust gase...

H. Lambrecht

1973-01-01

446

Topologie und Dynamische Netzwerke: Anwendungen Der Optimierung MIT Zukunft  

NASA Astrophysics Data System (ADS)

Die optimale Auslegung von Infrastrukturen z. B. bei der Verkehrsplanung und bei der Planung von Versorgungssystemen, die optimale Strukturierung bzw. Formgebung von Materialien und Werkstücken z. B. im Leichtbau sind aktuelle Themen angewandter Forschung. In beiden Bereichen wurde bis in die jüngste Zeit vornehmlich eine simulationsbasierte Optimierung auf der Grundlage einer Parameterjustierung vorgenommen, die oft wenig systematisch und zeit- und kostenintensiv ist. Stattdessen erweisen sich modellbasierte mathematische Optimierungsalgorithmen zusammen mit moderner numerischer Simulations-und Visualisierungstechnologie zunehmend als Katalysator neuer Technologien. Eine so verstandene Mathematische Optimierung kann bereits auf beeindruckende Erfolgsgeschichten verweisen und so den Anspruch als eine Zukunftsdisziplin behaupten. Diesem Anspruch trägt die Einrichtung des DFG-Schwerpunktprogramms 1253, Optimierung mit partiellen Differentialgleichungen’ im Jahre 2006 Rechnung, in dem über 25 Projekte im Bundesgebiet sowohl auf die theoretische Fundierung, als auch und insbesondere auf die Verzahn