Kinematics of the South Atlantic rift

The South Atlantic rift basin evolved as branch of a large Jurassic-Cretaceous intraplate rift zone between the African and South American plates during the final breakup of western Gondwana. By quantitatively accounting for crustal deformation in the Central and West African rift zone, we indirectly construct the kinematic history of the pre-breakup evolution of the conjugate West African-Brazilian margins. Our model suggests a causal link between changes in extension direction and velocity during continental extension and the generation of marginal structures such as the enigmatic Pre-salt sag basin and the S\~ao Paulo High. We model an initial E-W directed extension between South America and Africa (fixed in present-day position) at very low extensional velocities until Upper Hauterivian times ($\approx$126 Ma) when rift activity along in the equatorial Atlantic domain started to increase significantly. During this initial $\approx$17 Myr-long stretching episode the Pre-salt basin width on the conjugate Brazilian and West African margins is generated. An intermediate stage between 126.57 Ma and Base Aptian is characterised by strain localisation, rapid lithospheric weakening in the equatorial Atlantic domain, resulting in both progressively increasing extensional velocities as well as a significant rotation of the extension direction to NE-SW. Final breakup between South America and Africa occurred in the conjugate Santos--Benguela margin segment at around 113 Ma and in the Equatorial Atlantic domain between the Ghanaian Ridge and the Piau\'i-Cear\'a margin at 103 Ma. We conclude that such a multi-velocity, multi-directional rift history exerts primary control on the evolution of this conjugate passive margins systems and can explain the first order tectonic structures along the South Atlantic and possibly other passive margins.Comment: 46 Pages, 22 figures. Submitted to Solid Earth (http://www.solid-earth.net). Abstract shortened due to arXiv restrictions. New version contains revisions and amendments as per reviewers requests. Supplementary data is available at http://datahub.io/en/dataset/southatlanticrif

Contours in Visualization

This thesis studies the visualization of set collections either via or defines as the relations among contours. In the first part, dynamic Euler diagrams are used to communicate and improve semimanually the result of clustering methods which allow clusters to overlap arbitrarily. The contours of the Euler diagram are rendered as implicit surfaces called blobs in computer graphics. The interaction metaphor is the moving of items into or out of these blobs. The utility of the method is demonstrated on data arising from the analysis of gene expressions. The method works well for small datasets of up to one hundred items and few clusters. In the second part, these limitations are mitigated employing a GPU-based rendering of Euler diagrams and mixing textures and colors to resolve overlapping regions better. The GPU-based approach subdivides the screen into triangles on which it performs a contour interpolation, i.e. a fragment shader determines for each pixel which zones of an Euler diagram it belongs to. The rendering speed is thus increased to allow multiple hundred items. The method is applied to an example comparing different document clustering results. The contour tree compactly describes scalar field topology. From the viewpoint of graph drawing, it is a tree with attributes at vertices and optionally on edges. Standard tree drawing algorithms emphasize structural properties of the tree and neglect the attributes. Adapting popular graph drawing approaches to the problem of contour tree drawing it is found that they are unable to convey this information. Five aesthetic criteria for drawing contour trees are proposed and a novel algorithm for drawing contour trees in the plane that satisfies four of these criteria is presented. The implementation is fast and effective for contour tree sizes usually used in interactive systems and also produces readable pictures for larger trees. Dynamical models that explain the formation of spatial structures of RNA molecules have reached a complexity that requires novel visualization methods to analyze these model\''s validity. The fourth part of the thesis focuses on the visualization of so-called folding landscapes of a growing RNA molecule. Folding landscapes describe the energy of a molecule as a function of its spatial configuration; they are huge and high dimensional. Their most salient features are described by their so-called barrier tree -- a contour tree for discrete observation spaces. The changing folding landscapes of a growing RNA chain are visualized as an animation of the corresponding barrier tree sequence. The animation is created as an adaption of the foresight layout with tolerance algorithm for dynamic graph layout. The adaptation requires changes to the concept of supergraph and it layout. The thesis finishes with some thoughts on how these approaches can be combined and how the task the application should support can help inform the choice of visualization modality

Hydrogen adsorption in metal-organic frameworks: the role of nuclear quantum effects

The role of nuclear quantum effects on the adsorption of molecular hydrogen in metal-organic frameworks (MOFs) has been investigated on grounds of Grand-Canonical Quantized Liquid Density-Functional Theory (GC-QLDFT) calculations. For this purpose, we have carefully validated classical H2 -host interaction potentials that are obtained by fitting Born-Oppenheimer ab initio reference data. The hydrogen adsorption has first been assessed classically using Liquid Density-Functional Theory (LDFT) and the Grand-Canonical Monte Carlo (GCMC) methods. The results have been compared against the semi-classical treatment of quantum effects by applying the Feynman-Hibbs correction to the Born-Oppenheimer-derived potentials, and by explicit treatment within the Grand-Canonical Quantized Liquid Density-Functional Theory (GC-QLDFT). The results are compared with experimental data and indicate pronounced quantum and possibly many-particle effects. After validation calculations have been carried out for IRMOF-1 (MOF-5), GC-QLDFT is applied to study the adsorption of H2 in a series of MOFs, including IRMOF-4, -6, -8, -9, -10, -12, -14, -16, -18 and MOF-177. Finally, we discuss the evolution of the H2 quantum fluid with increasing pressure and lowering temperature

Grand-Canonical Quantized Liquid Density-Functional Theory in a Car-Parrinello Implementation

Quantized Liquid Density-Functional Theory [Phys. Rev. E 2009, 80, 031603], a method developed to assess the adsorption of gas molecules in porous nanomaterials, is reformulated within the grand canonical ensemble. With the grand potential it is possible to compare directly external and internal thermodynamic quantities. In our new implementation, the grand potential is minimized utilizing the Car-Parrinello approach and gives, in particular for low temperature simulations, a significant computational advantage over the original canonical approaches. The method is validated against original QLDFT, and applied to model potentials and graphite slit pores.Comment: 19 pages, 5 figure

Creating Competitive Advantage Through Telemedicine-based Value Webs

In most European countries public health is stepping towards an economic crises. Extensive competition thus challenges healthcare organizations to redesign their business, to evaluate their product/services portfolios, and to develop new strategies. In this context, the paper examines the creation of competitive advantage through telemedicine-based value webs. Telemedicine has the potential to offer new distribution channels to healthcare services, and it enables creating new cooperation and business models. The focus of our paper is on how information technology and in particular telemedicine can create new, or may change traditional business models in healthcare

[email protected] - Agent Based Support of Clinical Processes

In this paper we present a system for agent-based support of clinical processes. We describe the basic engineering concept, along with specific simulation and testing scenarios for agent-based software engineering. Another important focus is the integration of existing agent or healthcare standards like FIPA, DICOM and HL7. Objectives of our research activities in this project are: a substantial increase of the efficiency of hospital process management as well as the development of a specific goal oriented requirements engineering methodology. As most important challenges of the healthcare domain we have identified on the one hand individualized, patient oriented processes in diagnostics, therapy, nursing and administration and on the other hand extremely distributed decision processes and strong local (individual) autonomy with a high degree of situational dynamics. The example scenario on „clinical trials“ illustrates how the system shall support distributed clinical processes and how it interacts with other multiagent systems within the Agent.Hospital Framework and hospital information systems in the eHealth Lab introduced in this paper. The system development is part of the German Priority Research Program (SPP) 1083 “Intelligent Agents and their application in business scenarios”

Indikatoren zur Ausbildung im Hochschulbereich : Studien zum Innovationssystem Deutschlands Nr. 10-2004

Im Berichtssystem zur technologischen Leistungsfähigkeit Deutschlands werden verschiedene Zugänge zum Thema gewählt. Die berichteten und bewerteten Indikatoren setzen bei der Produktion und der Anwendung von technischem Wissen an. Hierbei konzentriert sich die Berichterstattung zunächst aufdie „Input“- oder Entstehungsseite. Themenbereiche sind die Bildung von „Humankapital“ und die Wissenschaft, aber auch die industriellen Aktivitäten in Forschung und Entwicklung als unmittelbarete chnologiebezogene Anstrengungen der Wirtschaft. Die Ergebnisse dieser „Wissensproduktion“ („Outputindikatoren“) - an denen man messen kann, welche Beiträge für die gesamtwirtschaftlicheErfolgsbilanz zu erwarten sind - finden ihre Ausprägung in Innovationen, Patenten, Unternehmensgründungen sowie in den Marktergebnissen für die gesamte inländische Produktion und Nachfrage,für die Beschäftigung und im Außenhandel. Die technologische Leistungsfähigkeit einer Volkswirtschaft verändert sich nicht in kurzer Frist, sondern vielmehr über einen längeren Zeitraum hinweg. Insbesondere zeigen sich die Wirkungen von Veränderungen der technologischen Leistungsfähigkeit auf die Realisierung gesamtwirtschaftlicher Ziele (wie z. B. hoher Beschäftigungsstand, angemessenes Wirtschaftswachstum, Steigerung der Produktivität und Preisstabilität) nicht von heute auf morgen, sondern vielfach zeitlich stark verzögert. Entsprechend ist zur Beurteilung der technologischen Leistungsfähigkeit einer Volkswirtschaft eine längerfristige Betrachtungsweise geboten, die jedoch kontinuierlich zu wiederholen ist, um rechtzeitig auf eventuelle „Warnzeichen“ reagieren zu können. Diesem Grundkonzept zufolge werden in der Berichterstattung zur technologischen Leistungsfähigkeit Deutschlands die Indikatoren so konstruiert, dass mit ihrer Hilfe Zusammenhänge und Hintergründe der kurz-, mittel- und langfristigen Entwicklung betrachtet werden können. Eine wichtige Nebenbedingung für eine Berichterstattung wie diese ergibt sich aus dem - für einen „Monitor“ typischen - Charakter der periodischen Aktualisierbarkeit. Es ist von der Arbeitsgruppe ein System von Indikatoren entwickelt worden, das weitgehend auf bereits vorhandenen Daten und regelmäßig erstellten Statistiken und Analysen aufbaut. Das Indikatorensystem ist nicht auf umfangreiche eigenständige Sondererhebungen und -untersuchungen angewiesen, damit die Berichterstattung zur technologischen Leistungsfähigkeit Deutschlands kontinuierlich, in regelmäßigen Abständen und mit überschaubarem Aufwand aktualisiert und weiterentwickelt werden kann. Ein Grundprinzip gilt unabhängig von der Fristigkeit der Beobachtung: Die Interpretation der Messziffern ergibt sich immer aus einem Vergleich mit konkurrierenden Volkswirtschaften und aus ihrer zeitlichen Entwicklung

The impact of steam on the electronic structure of the selective propane oxidation catalyst MoVTeNb oxide (orthorhombic M1 phase)

The selective propane oxidation catalyst MoVTeNb oxide M1 was investigated by microwave conductivity, synchrotron X-ray photoelectron, soft X-ray absorption and resonant photoelectron spectroscopy under reaction conditions to identify the influence of steam on the electronic bulk and surface properties. Steam significantly increases both the conversion of propane and the selectivity to the target product acrylic acid. The increased catalytic performance comes along with a decreased conductivity, a modification of the surface chemical and electronic structure with an enrichment of covalently bonded V5+ species to the extent of Mo6+, a decreased work function and hence polarity of the surface and a modified valence band structure. The higher degree of covalency in metal oxide bonds affects the mobility of the free charge carriers, and hence explains the decrease of the conductivity with steam. Furthermore we could prove that a subsurface space charge region depleted in electrons and thus an upward bending of the electronic band structure are induced by the reaction mixture, which is however not dependent on the steam content