3,397 research outputs found
Matter wave soliton bouncer
Dynamics of a matter wave soliton bouncing on the reflecting surface (atomic
mirror) under the effect of gravity has been studied by analytical and
numerical means. The analytical description is based on the variational
approach. Resonant oscillations of the soliton's center of mass and width,
induced by appropriate modulation of the atomic scattering length and the slope
of the linear potential are analyzed. In numerical experiments we observe the
Fermi type acceleration of the soliton when the vertical position of the
reflecting surface is periodically varied in time. Analytical predictions are
compared with the results of numerical simulations of the Gross-Pitaevskii
equation and qualitative agreement between them is found.Comment: 8 pages, 5 figure
Design, development and performance evaluation of a large-scale hybrid solar dryer
A large-scale hybrid solar dryer was developed to account the limitations encountered in traditional open sun drying. With loading capacity of 500 kg and incorporated with a hybrid heating control system, this dryer is suitable for industrial drying that requires large drying capacity and products with high moisture content. In addition, this drying system offers flexibility in switching between different combinations of air vents based on the drying purpose required. Chaotic air flow produced in the drying chamber ensure uniform temperature distribution across the drying trays in an updraft air movement. Potential application of the drying system for durian skin and chili drying were tested. Based on the performance evaluation, a maximum temperature and maximum average temperature of 66°C and 59°C, respectively, was attained in the drying chamber. The drying of chilli with the drying temperature set at 50°C and operating condition of using the ventilation fan and opening the air vent achieved the drying time of 5 days or 45 hours in total, equivalent to 9 hours of drying time per day
Measurement and QCD analysis of double-differential inclusive jet cross sections in pp collisions at s = 8 \backslashsqrt{s}=8 TeV and cross section ratios to 2.76 and 7 TeV
A measurement of the double-differential inclusive jet cross section as a function of the jet transverse momentum p T and the absolute jet rapidity |y| is presented. Data from LHC proton-proton collisions at s = 8 \backslashsqrt{s}=8 TeV, corresponding to an integrated luminosity of 19.7 fb−1, have been collected with the CMS detector. Jets are reconstructed using the anti-k T clustering algorithm with a size parameter of 0.7 in a phase space region covering jet p T from 74 GeV up to 2.5 TeV and jet absolute rapidity up to |y| = 3.0. The low-p T jet range between 21 and 74 GeV is also studied up to |y| = 4.7, using a dedicated data sample corresponding to an integrated luminosity of 5.6 pb−1. The measured jet cross section is corrected for detector effects and compared with the predictions from perturbative QCD at next-to-leading order (NLO) using various sets of parton distribution functions (PDF). Cross section ratios to the corresponding measurements performed at 2.76 and 7 TeV are presented. From the measured double-differential jet cross section, the value of the strong coupling constant evaluated at the Z mass is α S(M Z)þinspace=þinspace0.1164 −þinspace0.0043 +þinspace0.0060 , where the errors include the PDF, scale, nonperturbative effects and experimental uncertainties, using the CT10 NLO PDFs. Improved constraints on PDFs based on the inclusive jet cross section measurement are presented
Combined QCD and electroweak analysis of HERA data
A simultaneous fit of parton distribution functions (PDFs) and electroweak
parameters to HERA data on deep inelastic scattering is presented. The input
data are the neutral current and charged current inclusive cross sections which
were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In
addition, the polarisation of the electron beam was taken into account for the
ZEUS data recorded between 2004 and 2007. Results on the vector and
axial-vector couplings of the Z boson to u- and d-type quarks, on the value of
the electroweak mixing angle and the mass of the W boson are presented. The
values obtained for the electroweak parameters are in agreement with Standard
Model predictions.Comment: 32 pages, 10 figures, accepted by Phys. Rev. D. Small corrections
from proofing process and small change to Fig. 12 and Table
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