The interaction between NH3, CH4 and NO under different conditions of interest for combustion applications is analyzed, from both experimental and kinetic modeling points of view. Reduction of NO by ...reburn and by SNCR (selective non-catalytic reduction) strategies is evaluated, through an extense systematic study of the influence of the main variables of interest for NO reduction, by means of laboratory flow-reactor experiments at atmospheric pressure. Variables analyzed include: temperature in the 700 to 1500 K range, air stoichiometry from fuel-rich (λ = 0.31) to fuel-lean conditions (λ = 2.21), NH3/CH4 ratio in the 0.4 to 10.78 range, NH3/NO ratio in the 0.49 to 2.60 range the, and CH4/NO ratio in the 0.37 to 1.98 range, dilution level, and bath gas by using nitrogen and argon, the latter to allow the precise determination of nitrogen balances. Results are interpreted using a literature reaction mechanism, together with reaction pathway analysis tools, and the main findings are discussed. Results indicate that ammonia promotes the conversion of methane, while methane inhibits the conversion of ammonia, due to the competition for radicals of both components in the mixture. The interaction of ammonia and methane implies that the reduction of NO by NH3/CH4 mixtures is comparatively lower than the reduction obtained by NH3 and CH4 independently. Implications for practical applications of the reduction of NO by the studied mixtures are discussed.
The aim of this study was to assess the effects of team training on operational efficiency during outpatient MRI.
In this institutional review board-approved, HIPAA-compliant study, six MRI ...outpatient sites of a midwestern hospital system were randomized to serve as controls or have their teams trained in advanced communication skills. The fourth quarter of fiscal year 2015 was the trial baseline. The trial ended in the third quarter (Q3) of fiscal year 2016 (FY16). Equipment utilization (completed scans/available slots), hourly scan rates (total orders completed per machine per hour of operation), and no-show rates stratified by time were analyzed using the Cochran-Mantel-Haenszel method, with individual comparisons performed with Bonferroni correction.
The study encompassed 27,425 MRI examinations. Overall volume peaked at baseline and then declined over the following quarters. Compared with baseline, untrained sites experienced significant drops in equipment utilization (P < .01 for the first quarter of FY16 and P < .0001 for the second quarter of FY16 and Q3 FY16), decreasing from 77% to 65% over the study period, corresponding to a decrease from 1.15 to 0.97 in hourly scan rates. For trained sites, these metrics showed no significant change, with maintenance of hourly scan rates of 1.23 and 1.27 and equipment utilization rates of 83% and 85% between baseline and Q3 FY16. No-show rates remained stable at trained sites but increased at untrained sites in the last two quarters (P < .05). Nationally benchmarked patient satisfaction percentile ranking gradually increased at trained sites from 56th at baseline to 70th and successively decreased at untrained sites from 66th to 44th.
MRI outpatient facilities trained in advanced communication techniques may have more favorable operational efficiency than untrained sites in a saturated market.
We present the observation of doubly-produced $J/\psi$ mesons with the D0 detector at Fermilab in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV. The production cross section for both singly and ...doubly-produced $J/\psi$ mesons is measured using a sample with an integrated luminosity of 8.1~fb$^{-1}$. For the first time, the double $J/\psi$ production cross section is separated into contributions due to single and double parton scatterings. Using these measurements, we determine the effective cross section \sigteff, a parameter characterizing an effective spatial area of the parton-parton interactions and related to the parton spatial density inside the nucleon.
Drell-Yan lepton pairs produced in the process pp¯→ℓ+ℓ−+X through an intermediate γ*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the ...electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin2θefflept using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9–10 fb−1 of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin2θefflept=0.23148±0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin2θW, or equivalently the W-boson mass MW, using the zfitter software package yields sin2θW=0.22324±0.00033 or equivalently, MW=80.367±0.017 GeV/c2.
The effect of substrate temperature on the direct current magnetron‐sputtered zirconium oxide (ZrO2) dielectric films was investigated. Stoichiometric of the ZrO2 thin films was obtained at an oxygen ...partial pressure of 4.0 × 10−2 Pa. X‐ray diffraction studies revealed that the crystallite size in the layer was increased from 4.8 to 16.1 nm with increase of substrate temperature from 303 to 673 K. Metal‐oxide‐semiconductor devices were fabricated on ZrO2/Si stacks with Al gate electrode. The dielectric properties of ZrO2 layer and interface quality at ZrO2/Si were significantly influenced by the substrate temperature. The dielectric constant increased from 15 to 25, and the leakage current density decreased from 0.12 × 10−7 to 0.64 × 10−9 A cm−2 with the increase of substrate temperature from 303 to 673 K.
Objective The objective of the study was to compare neonatal morbidity and long-term neurodevelopmental outcome between very preterm infants with placental underperfusion and very preterm infants ...with histological chorioamnionitis. Study Design We measured the mental and motor development at age 2 and 7 years in 51 very preterm infants with placental underperfusion and 21 very preterm infants with histological chorioamnionitis. Results At 2 years, very preterm infants with placental underperfusion had poorer mental development than very preterm infants with histological chorioamnionitis (mean SD 90.8 18.3 vs 104.1 17.2, adjusted d = 1.12, P = .001). Motor development was not different between both groups (92.8 17.2 vs 96.8 8.7, adjusted d = 0.52, P = .12). At 7 years, large, although nonsignificant, effects were found for better mental and motor development and fewer behavioral problems in infants with histological chorioamnionitis. Conclusion Placental pathology contributes to variance in mental development at 2 years and should be taken into account when evaluating neurodevelopmental outcome of very preterm infants.
Thread-parallelisation and single-instruction multiple data (SIMD) "vectorisation" of software components in HEP computing has become a necessity to fully benefit from current and future computing ...hardware. In this context, the Geant-Vector GPU simulation project aims to re-engineer current software for the simulation of the passage of particles through detectors in order to increase the overall event throughput. As one of the core modules in this area, the geometry library plays a central role and vectorising its algorithms will be one of the cornerstones towards achieving good CPU performance. Here, we report on the progress made in vectorising the shape primitives, as well as in applying new C++ template based optimisations of existing code available in the Geant4, ROOT or USolids geometry libraries. We will focus on a presentation of our software development approach that aims to provide optimised code for all use cases of the library (e.g., single particle and many-particle APIs) and to support different architectures (CPU and GPU) while keeping the code base small, manageable and maintainable. We report on a generic and templated C++ geometry library as a continuation of the AIDA USolids project. The experience gained with these developments will be beneficial to other parts of the simulation software, such as for the optimisation of the physics library, and possibly to other parts of the experiment software stack, such as reconstruction and analysis.
We present a combination of measurements of the top quark mass by the D0 experiment in the lepton+jets and dilepton channels. We use all the data collected in Run I (1992–1996) at s=1.8 TeV and Run ...II (2001–2011) at s=1.96 TeV of the Tevatron pp¯ collider, corresponding to integrated luminosities of 0.1 fb−1 and 9.7 fb−1, respectively. The combined result is: mt=174.95±0.40(stat)±0.64(syst) GeV=174.95±0.75 GeV.
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