217 research outputs found

    Modeling and simulation of bulk gallium nitride power semiconductor devices

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    Bulk gallium nitride (GaN) power semiconductor devices are gaining significant interest in recent years, creating the need for technology computer aided design (TCAD) simulation to accurately model and optimize these devices. This paper comprehensively reviews and compares different GaN physical models and model parameters in the literature, and discusses the appropriate selection of these models and parameters for TCAD simulation. 2-D drift-diffusion semi-classical simulation is carried out for 2.6 kV and 3.7 kV bulk GaN vertical PN diodes. The simulated forward current-voltage and reverse breakdown characteristics are in good agreement with the measurement data even over a wide temperature range

    Effects of phosphate and hydrogen peroxide on the performance of a biological activated carbon filter for enhanced biofiltration

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    Biofilm formation on biofilters can influence their hydraulic performance, thereby leading to head loss and an increase in energy use and costs for water utilities. The effects of a range of factors, including hydrogen peroxide and phosphate, on the performance of biological activated carbon (BAC) and biofilm formation were investigated using laboratory-scale columns. Head loss, total carbohydrates, and proteins were reduced in the nutrient-enhanced, oxidant-enhanced, and nutrient + oxidant-enhanced BAC filters. However, there were no changes in the removal of dissolved organic matter, trihalomethane formation potential, or selected trace organic contaminants. The biofilm formation on polyvinyl chloride and stainless steel coupons using the laboratory biofilm reactor system was lower when the effluent from a nutrient-enhanced column was used, which indicated that there was less biofilm formation in the distribution systems. This may have been because the effluent from the nutrient-enhanced column was more biologically stable. Therefore, enhanced biofiltration could be used not only to reduce head loss in biofilters, but also to delay biofilm formation in distribution systems

    Neutron beam test of CsI crystal for dark matter search

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    We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and Îł\gamma's below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the 3^3H(p,n)3^3He reaction. This was compared to the response to Compton electrons scattered by 662 keV Îł\gamma-ray. Pulse shape discrimination between the response to these Îł\gamma's and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM

    FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

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    Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK

    Fine-Scale Mapping of the 5q11.2 Breast Cancer Locus Reveals at Least Three Independent Risk Variants Regulating MAP3K1

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    Effect of event selection on jetlike correlation measurement in d+Au collisions at sNN=200 GeV

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    AbstractDihadron correlations are analyzed in sNN=200 GeV d+Au collisions classified by forward charged particle multiplicity and zero-degree neutral energy in the Au-beam direction. It is found that the jetlike correlated yield increases with the event multiplicity. After taking into account this dependence, the non-jet contribution on the away side is minimal, leaving little room for a back-to-back ridge in these collisions

    J/ψ polarization in p+p collisions at s=200 GeV in STAR

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    AbstractWe report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2<pT<6 GeV/c in p+p collisions at s=200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λΞ measured at RHIC becomes smaller towards high pT, indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models

    Beam-energy Dependence Of Charge Balance Functions From Au + Au Collisions At Energies Available At The Bnl Relativistic Heavy Ion Collider

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    Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq)Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at sNN=7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at sNN=2.76TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at sNN=7.7 GeV implies that a QGP is still being created at this relatively low energy. © 2016 American Physical Society.942CNPq, Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgicoMinistry of Education and Science of the Russian FederationMOE, Ministry of Education of the People's Republic of ChinaMOST, Ministry of Science and Technology of the People's Republic of ChinaNRF-2012004024, National Research FoundationNSF, National Stroke FoundationConselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq

    Energy dependence of ϕ meson production at forward rapidity in pp collisions at the LHC

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    The production of ϕ\phi mesons has been studied in pp collisions at LHC energies with the ALICE detector via the dimuon decay channel in the rapidity region 2.5<y<42.5< y < 4. Measurements of the differential cross section d2σ/dydpT\mathrm{d}^2\sigma /\mathrm{d}y \mathrm{d}p_{\mathrm {T}} are presented as a function of the transverse momentum (pTp_{\mathrm {T}}) at the center-of-mass energies s=5.02\sqrt{s}=5.02, 8 and 13 TeV and compared with the ALICE results at midrapidity. The differential cross sections at s=5.02\sqrt{s}=5.02 and 13 TeV are also studied in several rapidity intervals as a function of pTp_{\mathrm {T}}, and as a function of rapidity in three pTp_{\mathrm {T}} intervals. A hardening of the pTp_{\mathrm {T}}-differential cross section with the collision energy is observed, while, for a given energy, pTp_{\mathrm {T}} spectra soften with increasing rapidity and, conversely, rapidity distributions get slightly narrower at increasing pTp_{\mathrm {T}}. The new results, complementing the published measurements at s=2.76\sqrt{s}=2.76 and 7 TeV, allow one to establish the energy dependence of ϕ\phi meson production and to compare the measured cross sections with phenomenological models. None of the considered models manages to describe the evolution of the cross section with pTp_{\mathrm {T}} and rapidity at all the energies.publishedVersio

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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