936 research outputs found
Manufacturing and Performance of supported BSCF-Membranes for oxygen separation
No full textManufacturing and Performance of supported BSCF-Membranes for oxygen separationNiehoff, P. (Corresponding Author)* ; Schulze-Küppers, F. * ; Baumann, S. * ; Vassen, R. * ; Buchkremer, H. P. * ; Meulenberg, W. A. *2015Wiley Interscience Hoboken, NJCeramic engineering and science proceedings 35(8), 325-335 (2015) G
More about Divisible Design Graphs
No full textAbstract: Divisible design graphs (DDG for short) have been recently defined by Kharaghani, Meulenberg and the second author as a generalization of (v, k, λ)-graphs. In this paper we give some new constructions of DDGs, most of them using Hadamard matrices and (v, k, λ)-graphs. For three parameter sets we give a nonexistence proof. Furthermore, we find conditions for a DDG to be walk-regular. It follows that most of the known examples are walk-regular, but some are not. In case walk-regularity of a DDG is forced by the parameters, necessary conditions for walk-regularity lead to new nonexistence results for DDGs. We examine all feasible parameter sets for DDGs on at most 27 vertices, establish existence in all but one cases, and decide on existence of a walk-regular DDG in all cases.divisible design graph;divisible design;walk-regular graph;(v;k;λ)-graph;Hadamard matrix
Biosensing Bioactive Contaminants, Assay Development and Hyphenation with Mass Spectrometry
No full textTowards Meaningful and Valuable Data Mining Results in Organizations: Developing a framework for data mining that facilitates interaction between decision makers and data scientists to successfully apply data mining in a business context
No full textData mining is more and more applied in organizations, but often fails to realize its full potential. It delivers too many results, and not all results are useful for the organization. Moreover, by applying DM in organizations, the interface between data mining and decision making has to be crossed. This report presents a framework to apply data mining in organizations. It has been established through insights of literature review and a case study. The framework focuses on a collaboration between data scientists and business stakeholders, making it the first attempt to consider data mining as a socio-technical system.Systems engineeringTechnology, Policy and Managemen
A Methodological Proposal for the Climate Change Risk Assessment of Coastal Habitats Based on the Evaluation of Ecosystem Services: Lessons Learnt from the INTERREG Project ECO-SMART
No full textHigh-Temperature Systems for a catalytic CO-Shift Membrane Reactor
No full textHigh-Temperature Systems for a catalytic CO-Shift MembraneReactorDésirée van Holt, Emanuel Forster , Wilhelm A. Meulenberg, Michael Müller, Mariya E.Ivanova, Stefan Baumann, Robert VaßenForschungszentrum Jülich, Institute of Energy and Climate Research, Leo-Brandt-Str., D-52425Juelich, Germanycorresponding author: [email protected] sequestration of CO2 via H2-selective, ceramic membranes in an IGCC-power plantis a highly interesting method, particularly for the high-temperature range of600 °C − 900 °C, due to the low efficiency losses that can be reached. It was shown thateven for this high-temperature range the utilization of a CO-shift catalyst leads to aconsiderable increase of the CO-conversion, at least up to 900 °C compared to anoperation mode without catalyst[1]. However, the harsh conditions of an IGCC-powerplant lead to very challenging operation conditions for the dense H2-selectivemembranes as well as for the CO-shift-catalysts.The present work aimed at the development of thermo-chemically and microstructurallystable, active and compatible membrane-catalyst systems for futurecatalytic CO-shift membrane-reactors. Therefore, the ceramic mixed protonic electronicconductors BaCe0.2Zr0.7Yb0.08Ni0.02O3−d and La5.5WO12−d were combined with ironbased catalysts like Fe/Cr/Cu-spinels. These materials were already studied intensivelyregarding the planned applications and show very good properties [2]. Additionally, formembrane-catalyst systems it is strongly required that the combined components donot influence each other negatively i.e. by diffusion or reaction.Figure: SEM picture of a cross section through a membrane-catalyst system of a 86Fe14Cr-catalyst on atape cast supported La5.5WO12−d-membrane after operation in a membrane reactor at 850 °C.The investigation identified material combinations that seem to be highly applicablefor future catalytic CO-shift membrane reactors in the high-temperature range up to900 °C. As shown in the figure above, the 86Fe14Cr-spinel catalyst and the La5.5WO12−d-membrane show very good compatibility. Additional investigations on membranereactorperformance, long term stability and scale up are necessary.[1] D. van Holt, Keramische Membranen für die H2-Abtrennung in CO-Shift-Reaktoren, DissertationRuhr-Universität Bochum 2014.[2] D. van Holt, E. Forster, M.E. Ivanova, W.A. Meulenberg, M. Müller, S. Baumann, R. Vaßen, Ceramicmaterials for H2 transport membranes applicable for gas separation under coal-gasification-relatedconditions, J. Eur. Ceram. Soc. 34 (2014) 2381 – 2389
A possible new adaptive control approach for ramp metering
No full textDue to increasing congestion there is a need for improved traffic control measures. During the Field Operational Test Integrated Management Amsterdam (Praktijkproef Amsterdam (PPA)) several control measures have been tested. One of them is ramp metering. The ramp metering algorithm, ALINEA, has been used with the "Parameterschatter" (Parameter estimator), which tries to estimate the critical density every time step. This is called adaptive control. This critical density is used to update the target density in the ALINEA algorithm. In an attempt to improve the ramp metering algorithm, next to the Parameterschatter, also a gradient method is used. The gradient method tries to tune the parameter gains in the ramp metering algorithm. In this thesis a variation on the normal ALINEA is used, a so-called Proportional-Integral(PI)-ALINEA. This PI-ALINEA has two parameter gains which will be updated towards the current situation on the freeway. The new adaptive controller (AD-RMC) is tested with the macroscopic traffic flow model METANET using a variable critical density and noisy measurements. The conclusion of this thesis is that the tuning of the parameter gains has benefit on the performance of the ramp meter installation in terms of travel time. Further research is needed (with for example a microscopic simulation model) on this algorithm before implementing it in practice.Traffic Flow Theory and Traffic NetworksTransport & PlanningCivil Engineering and Geoscience
Selective inhibition of γ-aminobutyric acid type A receptors in human IMR-32 cells by low concentrations of toluene
No full textEffects of the neurotoxic organic solvent toluene on human neuronal nicotinic acetylcholine (nACh) and gaminobutyric acid type A (GABAA) neurotransmitter receptors were investigated in whole-cell voltage-clamped IMR- 32 neuroblastoma cells. Ion currents evoked by near maximum effective concentrations of 1 mM acetylcholine (ACh) and 1 mM g-aminobutyric acid (GABA) are inhibited by toluene in a concentration-dependent way. Concentration/ effect curves of toluene yield IC50 values of 2769/26 and 399/6 mM and slope factors of 1.49/0.2 and 0.89/0.1 for inhibition of the ACh- and GABA-induced ion currents, respectively. The results demonstrate the selective inhibition of human GABAA receptors by toluene at concentrations comparable with brain concentrations associated with occupational exposure
Viable porcine arteriviruses with deletions proximal to the 3 ' end of the genome
No full textIn order to obtain attenuated live vaccine candidates of porcine reproductive and respiratory syndrome virus (PRRSV), a series of deletions was introduced at the 3′ end of the viral genome using an infectious cDNA clone of the Lelystad virus isolate. RNA transcripts from the full-length cDNA clones were transfected into BHK-21 cells. The culture supernatant of these cells was subsequently used to infect porcine alveolar macrophages to detect the production of progeny virus. It is shown that C-terminal truncation of the nucleocapsid (N) protein, encoded by ORF7, was tolerated for up to six amino acids without blocking the production of infectious virus. Mutants containing larger deletions produced neither virus nor virus-like particles containing viral RNA. Deletion analysis of the 3′ UTR immediately downstream of ORF7 showed that infectious virus was still produced after removal of seven nucleotides behind the stop codon of ORF7. Deletion of 32 nucleotides in this region abolished RNA replication and, consequently, no infectious virus was formed. Serial passage on porcine alveolar macrophages demonstrated that the viable deletion mutants were genetically stable at the site of mutation. In addition, the deletions did not affect the growth properties of the recombinant viruses in vitro, while their antigenic profiles were similar to that of wild-type virus. Immunoprecipitation experiments with the six-residue N protein-deletion mutant confirmed that the truncated protein was indeed smaller than the wild-type N protein. The deletion mutants produced in this study are interesting candidate vaccines to prevent PRRS disease in pigs
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