Eindhoven University of Technology

About: Eindhoven University of Technology is a education organization based out in Eindhoven, Noord-Brabant, Netherlands. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 22309 authors who have published 52936 publications receiving 1584164 citations. The organization is also known as: Technische Hogeschool Eindhoven & TU/e.

Design rationale of RuleML: a markup language for semantic web rules

Abstract: This paper lays out the design rationale of RuleML, a rule markup language for the Semantic Web. We give an overview of the RuleML Initiative as a Web ontology effort. Subsequently, the modular syntax and semantics of RuleML and the current RuleML 0.8 DTDs are presented (focusing on the Datalog and URI sublanguages). Then we discuss negation handling, priorities/evidences, as well as agents and RuleML. We next proceed to RuleML implementations via XSLT and rule engines. In our conclusions, we continue to explore the bigger picture of ontologies and discuss some requirements for a future RuleML. An appendix shows our Semantic Web scenario in the insurance industry.

Positive and negative streamers in ambient air: measuring diameter, velocity and dissipated energy

Abstract: Positive and negative streamers are studied in ambient air at 1 bar; they emerge from a needle electrode placed 40mm above a planar electrode. The amplitudes of the applied voltage pulses range from 5 to 96 kV; most pulses have rise times of 30 ns or shorter. Diameters, velocities and energies of the streamers are measured. Two regimes are identified; a low voltage regime where only positive streamers appear and a high voltage regime where both positive and negative streamers exist. Below 5 kV, no streamers emerge. In the range from 5 to 40 kV, positive streamers form, while the negative discharges only form a glowing cloud at the electrode tip, but no streamers. For 5–20 kV, diameters and velocities of the positive streamers have the minimal values of d = 0.2mm and v ≈ 10^5 ms^(−1). For 20–40 kV, their diameters increase by a factor of 6 while the voltage increases only by a factor of 2. Above the transition value of 40 kV, streamers of both polarities form; they strongly resemble each other, though the positive ones propagate further; their diameters continue to increase with applied voltage. For 96 kV, positive streamers attain diameters of 3mm and velocities of 4 × 10^6 ms^(−1); negative streamers are about 20% slower and thinner. An empirical fit formula for the relation between velocity v and diameter d is v = 0.5d^2 mm^(−1) ns^(−1) for both polarities. Streamers of both polarities dissipate energies of the order of several millijoules per streamer while crossing the gap.

The Effect of Thermal Treatment on the Morphology and Charge Carrier Dynamics in a Polythiophene–Fullerene Bulk Heterojunction

Abstract: The influence of various thermal treatment steps on the morphology and the photoconductive properties of a non-contacted, 50 nm thick blend (50:50 wt.-%) of [6,6]-phenyl C61-butyric acid methyl ester (PCBM) and poly(3-hexyl thiophene) (P3HT) spin-coated from chloroform has been studied using transmission electron microscopy (TEM) and the electrodeless time-resolved microwave conductivity technique. After annealing the film for 5 min at 80 °C, TEM images show the formation of crystalline fibrils of P3HT due to a more ordered packing of the polymer chains. The thermal treatment results in a large increase of the photoconductivity, due to an enhancement of the hole mobility in these crystalline P3HT domains from 0.0056 cm2 V–1 s –1 for the non-annealed sample to 0.044 cm2 V–1 s –1 for the sample annealed at 80 °C. In contrast, the temporal shape of the photoconductivity, with typical decay half-times, τ1/2, of 1 μs for the lowest excitation intensities, is unaffected by the temperature treatment. Further annealing of the sample at 130 °C results in the formation of three different substructures within the heterojunction: a PCBM:P3HT blend with PCBM-rich clusters, a region depleted of PCBM, and large PCBM single crystals. Only a minor increase in the amplitude, but a tenfold rise of the decay time of the photoconductivity, is observed. This is explained by the formation of PCBM-rich clusters and large PCBM single crystals, resulting in an increased diffusional escape probability for mobile charge carriers and hence reduced recombination.

Electrocatalytic reduction of NO3− on palladium/copper electrodes

Abstract: The reduction of NO3− on palladium/copper electrodes has been studied using differential electrochemical mass spectroscopy (DEMS), rotating ring-disk electrodes (RRDE) and quartz microbalance electrodes (ECQM). In acidic electrolytes, the activity increases linearly with Cu coverage, in alkaline electrolytes, a different dependence on coverage is observed. One monolayer of Cu gives a different selectivity from bulk copper. The adsorption of NO3− is competitive with SO42−, whereas Cl− adsorption blocks the reduction. Competitive adsorption lowers both the activity and the selectivity to N2. Copper activates the first electron transfer, the role of palladium is to steer the selectivity towards N2. The trends in activity and selectivity are explained in terms of coverage of N-species.