Warsaw University of Technology

About: Warsaw University of Technology is a education organization based out in Warsaw, Poland. It is known for research contribution in the topics: Microstructure & Optical fiber. The organization has 14293 authors who have published 34362 publications receiving 492211 citations. The organization is also known as: Warsaw Polytechnic & Politechnika Warszawska.

Strange baryon resonance production in sNN=200GeV p+p and Au+Au collisions

Abstract: We report the measurements of Σ(1385) and Λ(1520) production in p+p and Au+Au collisions at √sNN=200 GeV from the STAR Collaboration. The yields and the p_T spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Opening metal-organic frameworks Vol. 2: Inserting longer pillars into pillared-paddlewheel structures through solvent-assisted linker exchange

Abstract: Solvent-assisted linker exchange (SALE) was performed on a pillared-paddlewheel metal–organic framework (MOF), SALEM-5, to achieve incorporation of longer linkers into the material. The 9-A meso-1,2-di(4-pyridyl)-1,2-ethanediol pillar of SALEM-5 was successfully replaced by 11-A, 14-A, and 17-A pillars to generate daughter MOFs SALEM-6, SALEM-7, and SALEM-8. The daughter frameworks possess more open cages, as was demonstrated by structural modeling from the powder X-ray diffraction patterns, and larger solvent accessible space, as was demonstrated by thermogravimetric analysis. Finally, a study was performed to examine the effect of pKa of monoprotonated dipyridyl pillars (as an indicator of the Zn–L bond strength) on the outcome of SALE.

Finite-Control-Set Model-Predictive Control for a Quasi-Z-Source Four-Leg Inverter Under Unbalanced Load Condition

Abstract: This paper presents finite-control-set model-predictive control (FCS-MPC) for a three-phase quasi-Z-source (qZS) four-leg inverter under unbalanced load condition. The key novelty of the proposed control approach is eliminating the double-line frequency ripple in the inductor current with a simple and effective approach. The proposed four-leg qZS inverter with an output $LC$ filter can handle buck/boost and dc/ac conversion features in a single stage. Furthermore, the FCS-MPC-based control algorithm helps in maintaining balanced point of common coupling voltages for stand-alone unbalanced loads. The behavior of the predictive controller has been investigated under different operating conditions, and its robustness with the qZS network and the $LC$ filter parameter variations are also studied. Furthermore, the effect of double-line frequency ripple and its relation with the inductor current constraint have been tackled comprehensively. To verify the performance of the proposed approach, simulation and experimental studies were performed for balanced and unbalanced loads.

Plasma-catalytic methane conversion with carbon dioxide in dielectric barrier discharges

Abstract: The hybrid plasma-catalytic system was tested for the mixture of methane and CO2 conversion at the pressure of 1.2 bar with the use of a dielectric barrier discharge (DBD) reactor powered at the frequency of 5.7–6 kHz. Three kinds of catalytic packing were examined: alumina ceramic carrier (Al2O3) and two catalysts, i.e. Ag/Al2O3 and Pd/Al2O3. The effects of temperature (120–290 °C), [CO2]:[CH4] molar ratio in the inlet gas mixtures (CH4 + CO2 + Ar), gas flow rate, and specific energy on the conversion were studied. Hydrogen, carbon oxide, hydrocarbons (ethane, ethylene + acetylene fraction, propane, propylene, n-butane, and i-butane), and alcohols (methanol and ethanol) were identified in the outlet gas. Among the organic gaseous products, ethane was dominant over the entire parameter range under examination. Non-volatile products (carbon, macromolecular substances) formed a visible deposit on the quartz dielectric barrier and metal electrode surfaces. With the Pd/Al2O3 catalyst, the overall methane conversion was 30–50% and the methane conversion to C2–C4 hydrocarbons reached 22%.

Measurement of charged jet suppression in Pb-Pb collisions at √s NN = 2.76 TeV

Abstract: A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at √sNN = 2.76TeV is reported. Jets are reconstructed from charged particles using the anti-k T jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudo-rapidity |η| < 0.5. The transverse momentum p T of charged particles is measured down to 0.15 GeV/c which gives access to the low p T fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R = 0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high p T leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R = 0.2 and R = 0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R < 0.3. [Figure not available: see fulltext.] © 2014 The Author(s).