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Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state of two muons and two tau leptons in proton-proton collisions at TeV
No full textA search for exotic Higgs boson decays to light pseudoscalars in the final state of two muons and two tau leptons is performed using proton-proton collision data recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb(-1). Masses of the pseudoscalar boson between 15.0 and 62.5 GeV are probed, and no significant excess of data is observed above the prediction of the standard model. Upper limits are set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different types of two-Higgs-doublet models extended with a complex scalar singlet
WISHE-Moisture Mode in an Aquaplanet Simulation
No full textThis study aims to understand the nature of the tropical intraseasonal oscillations (ISOs) in an aquaplanet simulation performed using Geophysical Fluid Dynamics Laboratory's AM2.1 with a uniform sea surface temperature within the deep tropics. The simulated ISO resembles the observed Madden-Julian Oscillation in that the spectral peak in precipitation appears at zonal wave number 1 and a period of similar to 60days. Vertically integrated moist static energy budget of the simulated ISO shows that enhanced latent heat flux to the east of anomalously active convection causes eastward propagation of the ISO mode, which is weakly opposed by horizontal moisture advection. A series of mechanism denial experiments are conducted either by homogenizing select variablessurface wind stress, longwave radiative heating, and surface evaporationwith their zonal means from the control simulation or by suppressing free-tropospheric moisture variation. Results of the mechanism denial experiments show that the simulated ISO disappears when the interactive surface evaporation is disabled, suggesting that the wind-induced surface heat exchange (WISHE) mechanism is essential to the simulated ISO. Longwave cloud-radiation feedbacks and moisture-convection feedbacks affect horizontal scale and phase speed of the simulated ISO, respectively. Our results strongly suggest that the simulated ISO is the linear WISHE-moisture mode of Fuchs and Raymond under horizontally uniform boundary conditions
Tetrahedrite (Cu12Sb4S13) thin films for photovoltaic and thermoelectric applications
No full textIn this paper we have demonstrated the growth of Cu12Sb4S13 thin film through e-beam evaporation from a single source. The source material was pre-synthesised via ball mill method starting from a stoichiometric mixture of elements (Cu, Sb and S) taken in the atomic ratio of 12:4:13. The films were deposited at different beam currents viz. 40, 50 and 60 mA. The bulk material and thin films were studied using X-ray diffraction (XRD) and Raman spectroscopy to evaluate phase formation. The films grown at beam current values of 40 mA showed the presence of Cu12Sb4S13 phase along with Cu3SbS4 and CuS secondary phases. The films grown at 50 mA and 60 mA are showing Cu3SbS4 phase as main phase. These results are in agreement with the Raman studies. The composition of as grown films was analysed using Rutherford backscattered spectrometry (RBS) and proton induced X-ray emission (PIXE) measurements. The Cu content in the films is decreasing with increase in the beam current, whereas the Sb and S content shows increment. The optical absorption measurement was used to determine the optical band gap. The films show a direct band gap value of similar to 1.8 eV with an optical absorption coefficient of similar to 10(5) cm(-1). Temperature dependant Seebeck coefficient and electrical resistivity values were measured for the thin films and the power factor values were calculated. The positive Seebeck coefficient values obtained indicate p-type semiconducting nature of the films. The maximum power factor of 2.30 mu W/cm-K-2 at 495 K was obtained for films grown at 40 mA e-beam current. The electrical and optical properties are significantly influenced by the presence of secondary phases and compositional deviation
RETRACTION: Multifunctional magnetic reduced graphene oxide dendrites: Synthesis, characterization and their applications (Retraction of Vol 68, Pg 726, 2015)
No full textApplication of monodisperse Fe3O4 submicrospheres in magnetorheological fluids
No full textSteady shear response of a magnetorheological fluid (MRF) system containing porous mono-disperse magnetite (Fe3O4) spheres synthesized by solvothermal method is demonstrated. In applied magnetic field the interaction between the spherical particles leads to form strong columnar structures enhancing the yield strength and viscosity of the MRFs. The yield strengths of the MRFs also scale up with the concentration of magnetic particles in the fluid. Considering magnetic dipolar interaction between the particles the magneto-mechanical response of the MRFs is explained. Unlike metallic iron particles, the low-density corrosion resistant soft-ferrimagnetic Fe3O4 spherical particles make our studied MRF system efficient and reliable for shock-mitigation/vibration-isolation applications. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved
Stimulation of angiogenesis using single-pulse low-pressure shock wave treatment
No full textEndothelial cells respond to mechanical stimuli such as stretch. This property can be exploited with caution to induce angiogenesis which will have immense potential to treat pathological conditions associated with insufficient angiogenesis. The primary aim of this study is to test if low-pressure shock waves can be used to induce angiogenesis. Using a simple diaphragm-based shock tube, we demonstrate that a single pulse of low pressure (0.4bar) shock wave is enough to induce proliferation in bovine aortic endothelial cells and human pulmonary microvascular endothelial cells. We show that this is associated with enhanced Ca++ influx and phosphorylation of phosphatidylinositol-3-kinase (PI3K) which is normally observed when endothelial cells are exposed to stretch. We also demonstrate the pro-angiogenic effect of shock waves of single pulse (per dose) using murine back punch wound model. Shock wave treated mice showed enhanced wound-induced angiogenesis as reflected by increased vascular area and vessel length. They also showed accelerated wound closure compared to control mice. Overall, our study shows that just a single pulse/shot (per dose) of shock waves can be used to induce angiogenesis. Importantly, we demonstrate this effect using a pulse of low-pressure shock waves (0.4bar, in vitro and 0.15bar, in vivo).Key messagesLow-pressure single-pulse shock waves can induce endothelial cell migration and proliferation.This effect is endothelial cell specific.These shock waves enhance wound-induced angiogenesis in vivo.These shock waves can also accelerate wound healing in vivo
Experimental investigation for performance assessment of scheduling policies in semiconductor wafer fabrication-a simulation approach
No full textThis paper is concerned with assessing the impact of 15 existing release policies in combination with three dispatching rules (together called as scheduling policy) on the performance of semiconductor fabrication facilities using a simulation model of a representative but fictitious semiconductor wafer fab. The performance criteria employed includes average cycle time, standard deviation of cycle time, work in process (WIP) level, and throughput. Arena simulation software is used to build the simulation model and conduct the experimental study. The experimental results indicate that workload regulating (WR), constant work in process (CONWIP), and constant load (CONLOAD) policies are superior among tested release policies and shortest remaining processing time (SRPT) is the best dispatching rule. This paper present a new release policy called as constant workload (CONSTWL), which is a modified version of CONWIP policy to overcome the limitations of traditional release policies. CONSTWL policy triggers the release of job into the system based on the overall workload of shop floor. Results on computational experiments indicate that CONSTWL outperforms traditional release policies in terms of the average cycle time, the standard deviation of cycle time and work in process under a prescribed throughput level. The positive impact of CONSTWL policy on system performance appears to be reliable with the increase of system congestion level. CONSTWL policy may prove useful in practical contexts of make to stock manufacturing environment whose orders are met usually from finished inventory
Development of Assay Systems for Amber Codon Decoding at the Steps of Initiation and Elongation in Mycobacteria
No full textGenetic analysis of the mechanism of protein synthesis in Gram-positive bacteria has remained largely unexplored because of the unavailability of appropriate in vivo assay systems. We developed chloramphenicol acetyltransferase (CAT)-based in vivo reporter systems to study translation initiation and elongation in Mycobacterium smegmatis. The CAT reporters utilize specific decoding of amber codons by mutant initiator tRNA (i-tRNA, metU) molecules containing a CUA anticodon (metUcuA). The assay systems allow structure-function analyses of tRNAs without interfering with the cellular protein synthesis and function with or without the expression of heterologous GInRS from Escherichia coll. We show that despite their naturally occurring slow-growth phenotypes, the step of i-tRNA formylation is vital in translation initiation in mycobacteria and that formylation-deficient i-tRNA mutants (MetU(CUA/A1), MetU(CUA/G72), and metU(CUA/G72G73)) with a Watson-Crick base pair at the 1.72 position participate in elongation. In the absence of heterologous GInRS expression, the mutant tRNAs are predominantly aminoacylated (glutamylated) by nondiscriminating GIuRS. Acid urea gels show complete transamidation of the glutamylated metU(CUA/G72G73) tRNA to its glutaminylated form (by GatCAB) in M. smegmatis. In contrast, the glutamylated metU(CUA/G72) tRNA did not show a detectable level of transamidation. Interestingly, the metU(CUA/A1) mutant showed an intermediate activity of transamidation and accumulated in both glutamylated and glutaminylated forms. These observations suggest important roles for the discriminator base position and/or a weak Watson-Crick base pair at 1.72 for in vivo recognition of the glutamylated tRNAs by M. smegmatis GatCAB. IMPORTANCE Genetic analysis of the translational apparatus in Gram-positive bacteria has remained largely unexplored because of the unavailability of appropriate in vivo assay systems. We developed chloramphenicol acetyltransferase (CAT)-based reporters which utilize specific decoding of amber codons by mutant tRNAs at the steps of initiation and/or elongation to allow structure-function analysis of the translational machinery. We show that formylation of the initiator tRNA (i-tRNA) is crucial even for slow-growing bacteria and that i-tRNA mutants with a CUA anticodon are aminoacylated by nondiscriminating GIuRS. The discriminator base position, and/or a weak Watson-Crick base pair at the top of the acceptor stem, provides important determinants for transamidation of the i-tRNA-attached Glu to Gln by the mycobacterial GatCAB
In Situ Fabrication of a Nickel/Molybdenum Carbide-Anchored N-Doped Graphene/CNT Hybrid: An Efficient (Pre)catalyst for OER and HER
No full textDespite the recent promise of transition metal carbides as nonprecious catalysts for the hydrogen evolution reaction (HER), their extension to the oxygen evolution reaction (OER) to achieve the goal of overall water splitting remains a significant challenge. Herein, a new Ni/MoxC (MoC, Mo2C) nanoparticle-supported N-doped graphene/carbon nanotube hybrid (NC) catalyst is developed via a facile, one-step integrated strategy, which can catalyze both the HER and OER in an efficient and robust manner. The catalyst affords low overpotentials of 162 and 328 mV to achieve a current density of 10 mA/cm(2) for HER and OER, respectively, in alkaline medium, which either compares favorably or exceeds most of the Mo-based catalysts documented in the literature. It is believed that there is an electronic synergistic effect among MoxC, Ni, and NC, wherein a tandem electron transfer process (Ni -> MoxC -> NC) may be responsible for promoting the HER as well as OER activity. This work opens a new avenue toward the development of multicomponent, highly efficient but inexpensive electrocatalysts for overall water splitting