50175 research outputs found
Sort by
Parallel Sparse LU Factorization of Power Flow Jacobian using GPU
No full textParallelizing the LU factorization of sparse Jacobian matrices reduces the execution time of the power flow algorithm which aids in real time control of the power system. In this paper, acceleration of LU factorization by employing different Graphical Processing Units(GPUs) is discussed. The hybrid column based right-looking LU factorization algorithm is found to be more amenable for GPU implementation. The structural symmetry property of non-zeros in the matrix is exploited to maximize the column/node level parallelization through a matrix re-ordering scheme obtained from Jess-Kees' algorithm. Also the influence of different fill-in reducing matrix re-orderings in the context of parallelization and execution time is discussed. The proposed method is tested on a set of power flow Jacobians with dimensions ranging from 4438 to 1136128 on different GPUs. Results from the current work demonstrate scalability of the proposed method with progressively powerful GPUs yielding better execution times. Efficacy of the proposed method is corroborated by improved speedup in execution when compared with CPU-based serial sparse system solvers like UMFPACK and KLU
Sub-diffraction resolution of periodic grating structures in a focus engineered sum frequency generation microscope
No full textUse of Toraldo-Type pupil phase masks in a nonlinear sum frequency generation microscope for subdiffraction resolution improvement is simulated. It is found that optimally chosen 0-w phase mask of diameter 64 of the full aperture results in reduction in the nonlinear focal field by 60 of the no phase mask case with 75 of energy concentrated in the central lobe. When imaging periodic grating structures, resonant enhancement and reversal of contrast are observed for grating pitch comparable to the diameter of the side lobes. The resonant contrast enhancement can potentially be used for selectively amplifying certain spatial frequencies in the sample
Multiferroic properties of lead-free 0.2(Ni0.8 Zn0.2Fe2O4)-0.8(Ba0.85Ca0.15Zr0.1Ti0.9O3) magnetoelectric composite
No full textIn this work the structural, electric and magnetic characteristics of 0.2(Ni0.8 Zn0.2Fe2O4 (NZF))-0.8 (Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT)) multiferroic composite is investigated. The constituent phases were synthesized by sol-gel process, and mixed in an appropriate ratio to form the composite. The XRD data and Rietveld refinement confirm that the composite exists in cubic+tetragonal+orthorhombic mixed phases. The P-E loop of the composite shows a finite loop opening with a decrease in the polarization compared to the pure BCZT. The M-H loops show a saturated loop at an applied field � 1 kOe and the values of magnetization decreased nearly by four orders, compared to the pure NZF
The Foreign Body Response Demystified
No full textThe human body is endowed with an uncanny ability to distinguish self from foreign. The implantation of a foreign object inside a mammalian host activates complex signaling cascades, which lead to biological encapsulation of the implant. This reaction by the host system to a foreign object is known as foreign body response (FBR). Over the last few decades, it has been increasingly important to have a deeper insight into the mechanisms of FBR is needed to develop biomaterials for better integration with living systems. In the light of recent advances in tissue engineering and regenerative medicine, particularly in the field of biosensors and biodegradable tissue engineering scaffolds, the classical concepts related to the FBR have acquired new dimensions. The aim of this review is to provide a holistic view of the FBR, while critically analyzing the challenges, which need to be addressed in the future to overcome this innate response. In particular, this review discusses the relevant experimental methodology to assess the host response. The role of erosion and degradation behavior on FBR with biodegradable polymers is largely explored. Apart from the discussion on temporal progression of FBR, an emphasis has been given to the design of next-generation biomaterials with favorable host response
Search for Dark Matter Particles Produced in Association with a Top Quark Pair at root s=13 TeV
No full textA search is performed for dark matter particles produced in association with a top quark pair in proton-proton collisions at root s = 13 TeV. The data correspond to an integrated luminosity of 35.9 fb(-1) recorded by the CMS detector at the LHC. No significant excess over the standard model expectation is observed. The results are interpreted using simplified models of dark matter production via spin-0 mediators that couple to dark matter particles and to standard model quarks, providing constraints on the coupling strength between the mediator and the quarks. These are the most stringent collider limits to date for scalar mediators, and the most stringent for pseudoscalar mediators at low masses
Long-Range Transport of Mineral Dust to the Northeast Indian Ocean: Regional versus Remote Sources and the Implications
No full textSynergizing satellite remote sensing data with vertical profiles of atmospheric thermodynamics and regional climate model simulations, we investigate the relative importance, transport pathways, and seasonality of contribution of dust from regional (Thar Desert and adjoining arid regions) and remote (southwest Asia and northeast Africa) sources over the northeast Indian Ocean i.e., the Bay of Bengal (BOB)]. We show that while over the northern BOB dust from the regional sources contribute more than 50% to the total dust load during the southwest monsoon period (June-September), interestingly; the remote dust sources dominate rest of the year. On the other hand, over the southern BOB, dust transported from the remote-source regions dominate throughout the year. During June, the dry elevated layer (at altitudes between 850 and 700 hPa) of dust, transported across the Indo-Gangetic Plain to the northern BOB, arises primarily from the Thar Desert. Dust from remote sources in the far west reaches the southern BOB after traversing over and around the southern Indian Peninsula. Since dust from these distinct source regions have different mineral composition (hence optical properties) and undergo distinct changes during atmospheric transport, it is important to understand source-specific dust contribution and transport pathways to address dust-climate feedback
Room temperature growth of CH3NH3PbCl3 single crystals by solvent evaporation method
No full textWe report a new route to synthesize high-quality, large-size crystals of CH3NH3PbCl3 through proper selection of DSMO-GBL solution via solvent evaporation method at room temperature. A detailed evaluation of the structural, electronic, optical and electrical properties of these crystals was carried out. Our XPS studies suggested that organic-inorganic halide perovskites are sensitive to X-ray-induced damage, and hence, their properties may get altered. Also, photoluminescence studies displayed two peak spectra, indicating coexistence of order-disorder domains of CH3NH3 in the sample. Further observation of low defect concentration and longer diffusion length indicates that crystals grown by the presented method can offer promising solutions for optoelectronic devices
Non-Gaussian elliptic-flow fluctuations in PbPb collisions at root S-NN=5.02 TeV
No full textEvent-by-event fluctuations in the elliptic-flow coefficient v(2) are studied in PbPb collisions at root S-NN = 5.02 TeV using the CMS detector at the CERN LHC. Elliptic-flow probability distributions p(v(2)) for charged particles with transverse momentum 0.3 < p(T) < 3.0 GeV/c and pseudorapidity vertical bar eta vertical bar < 1.0 are determined for different collision centrality classes. The moments of the p(v(2)) distributions are used to calculate the v(2) coefficients based on cumulant orders 2, 4, 6, and 8. A rank ordering of the higher-order cumulant results and nonzero standardized skewness values obtained for the p(v(2)) distributions indicate non-Gaussian initial-state fluctuations. Bessel-Gaussian and elliptic power fits to the flow distributions are studied to characterize the initial-state spatial anisotropy. (C) 2018 The Author(s). Published by Elsevier B.V
Search for rare decays of Z and Higgs bosons to J/ψ and a photon in proton-proton collisions at s√ = 13 TeV
No full textAbstract A search is presented for decays of Z and Higgs
bosons to a J/ψ meson and a photon, with the subsequent
decay of the J/ψ to μ+μ−. The analysis uses data from
proton-proton collisions with an integrated luminosity of
35.9 fb−1 at √s = 13 TeV collected with the CMS detector at the LHC. The observed limit on the Z → J/ψγ decay
branching fraction, assuming that the J/ψ meson is produced
unpolarized, is 1.4 × 10−6 at 95% confidence level, which
corresponds to a rate higher than expected in the standard
model by a factor of 15. For extreme-polarization scenarios, the observed limit changes from −13.6 to +8.6% with
respect to the unpolarized scenario. The observed upper limit
on the branching fraction for H → J/ψγ where the J/ψ
meson is assumed to be transversely polarized is 7.6×10−4,
a factor of 260 larger than the standard model prediction.
The results for the Higgs boson are combined with previous
data from proton-proton collisions at √s = 8 TeV to produce an observed upper limit on the branching fraction for
H → J/ψγ that is a factor of 220 larger than the standard
model value
Measurement of inclusive and differential Higgs boson production cross sections in the diphoton decay channel in proton-proton collisions at root s=13 TeV
No full textMeasurements of the inclusive and differential production cross sections for the Higgs boson in the diphoton decay channel are performed using the data set of proton-proton collisions at 13 TeV collected by the CMS experiment at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb(-1). The cross sections are measured in a fiducial phase space defined by a set of requirements on the isolation and kinematic variables of the photons. Differential cross sections are measured as functions of the kinematic properties of the diphoton system and the event. A subset of the measurements is performed in regions of the fiducial phase space, where relative contributions of specific Higgs boson production mechanisms are enhanced. The total cross section in the chosen fiducial phase space is measured to be 84 +/- 11 (stat) +/- 7 (syst) fb = 84 +/- 13 fb, to be compared with a theoretical prediction of 73 +/- 4 fb. All measurements are found to be in agreement with the theoretical predictions for the standard model Higgs boson with a mass of 125.09 GeV within the experimental and theoretical uncertainties