Vienna University of Technology

About: Vienna University of Technology is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Laser & Cloud computing. The organization has 16723 authors who have published 49341 publications receiving 1302168 citations.

Oxozirconium Methacrylate Clusters: Zr6(OH)4O4(OMc)12 and Zr4O2(OMc)12 (OMc = Methacrylate)

Abstract: The crystalline oxozirconium methacrylate clusters Zr6(O-H)4O4(OMc)12 and Zr4O2(OMc)12 were obtained by reaction of Zr(OnPr)4 with an excess of methacrylic acid and analysed by X-ray diffraction. The oxide and hydroxide groups are in a μ3- bridging mode in both structures, and the methacrylate ligands are chelating or bridging. The zirconium atoms in Zr6(OH)4O4(OMc)12 form an octahedron the cluster having crystalographic C3v symmetry. Each metal atom is square-antiprismatically coordinated by eight oxygen atoms. In Zr4O2(OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square-antiprismatically coordinated by eight oxygen atomes. In Zr4O2)OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square-antiprismatic or capped octahedral.

Steam gasification of various feedstocks at a dual fluidised bed gasifier: Impacts of operation conditions and bed materials

Abstract: Gasification of biomass is an attractive technology for combined heat and power production as well as for synthesis processes such as production of liquid and gaseous biofuels. Dual fluidised bed (DFB) technology offers the advantage of a nearly nitrogen-free product gas mainly consisting of H2, CO, CO2 and CH4. The DFB steam gasification process has been developed at Vienna University of Technology over the last 15 years using cold flow models, laboratory units, mathematical modelling and simulation. The main findings of the experimental work at a 100-kW pilot scale unit are presented. Different fuels (wood pellets, wood chips, lignite, coal, etc.) and different bed materials (natural minerals such as olivine, limestones, calcites, etc. as well as modified olivines) have been tested and the influence on tar content as well as gas composition was measured and compared among the different components. Moreover, the influence of operating parameters such as fuel moisture content, steam/fuel ratio and gasification temperature on the product gas has been investigated. DFB steam gasification of solid biomass coupled with CO2 capture, the so-called absorption enhanced reforming (AER) process, is highlighted. The experiments in pilot scale led to commercial realisation of this technology in demonstration scale. Summarising, the DFB system offers excellent fuel flexibility to be used in advanced power cycles as well as in polygeneration applications.

Robust creation of entanglement between remote memory qubits.

Abstract: In this Letter we propose a robust quantum repeater architecture building on the original Duan-Lukin-Cirac-Zoller (DLCZ) protocol [L.-M. Duan, M. D. Lukin, J. I. Cirac, and P. Zoller, Nature (London) 414, 413 (2001)10.1038/35106500]. The architecture is based on two-photon Hong-Ou-Mandel-type interference which relaxes the long-distance stability requirements by about 7 orders of magnitude, from subwavelength for the single photon interference required by DLCZ to the coherence length of the photons. Our proposal provides an exciting possibility for robust and realistic long-distance quantum communication.

Importance-driven feature enhancement in volume visualization

Abstract: This paper presents importance-driven feature enhancement as a technique for the automatic generation of cut-away and ghosted views out of volumetric data. The presented focus+context approach removes or suppresses less important parts of a scene to reveal more important underlying information. However, less important parts are fully visible in those regions, where important visual information is not lost, i.e., more relevant features are not occluded. Features within the volumetric data are first classified according to a new dimension, denoted as object importance. This property determines which structures should be readily discernible and which structures are less important. Next, for each feature, various representations (levels of sparseness) from a dense to a sparse depiction are defined. Levels of sparseness define a spectrum of optical properties or rendering styles. The resulting image is generated by ray-casting and combining the intersected features proportional to their importance (importance compositing). The paper includes an extended discussion on several possible schemes for levels of sparseness specification. Furthermore, different approaches to importance compositing are treated.