30,677 research outputs found
Time division access feasibility study modulation and synchronization considerations
Time division access system for satellite communications, and figure of merit for effects of bit and frequency synchronizatio
Search for Narrow-Width ttbar Resonances in ppbar Collisions at center of mass energy = 1.8 TeV
We present a preliminary result on a search for narrow-width resonances that
decay into ttbar pairs using 130 pb^{-1} of lepton plus jets data in ppbar
collisions at center of mass energy = 1.8 TeV. No significant deviation from
Standard Model prediction is observed. 95% C.L. upper limits on the production
cross section of the narrow-width resonance times its branching fraction to
ttbar are presented for different resonance masses, M_X. We also exclude the
existence of a leptophobic topcolor particle, X, with M_X < 560 GeV/c^2 for a
width \Gamma_X = 0.012 M_X.Comment: 3 pages, 1 figure; Submitted for proceedings of 5th International
Conference on Quark Confinement and Hadron spectrum, held in Italy, from
11-14 Sep., 200
The Quantum de Laval Nozzle: stability and quantum dynamics of sonic horizons in a toroidally trapped Bose gas containing a superflow
We study an experimentally realizable system containing stable black
hole-white hole acoustic horizons in toroidally trapped Bose-Einstein
condensates - the quantum de Laval nozzle. We numerically obtain stationary
flow configurations and assess their stability using Bogoliubov theory, finding
both in hydrodynamic and non-hydrodynamic regimes there exist dynamically
unstable regions associated with the creation of positive and negative energy
quasiparticle pairs in analogy with the gravitational Hawking effect. The
dynamical instability takes the form of a two mode squeezing interaction
between resonant pairs of Bogoliubov modes. We study the evolution of
dynamically unstable flows using the truncated Wigner method, which confirms
the two mode squeezed state picture of the analogue Hawking effect for low
winding number.Comment: 12 pages, 10 figure
Magneto-Spectral Studies on Some Trivalent Metal Complexes: Chromium, Iron and Cobalt Complexes Derived from 4-Benzylamidothiosemicarbazide and its Thiosemicarbazone.
Complexes of chromium(Ill), iron(lll) and cobalt(III) with
4-benzy lamidothiosemicarbazide (BTSC) and 1-( a-)fury 1-4-benzy lamidothiosemicarbazone
(FBTS) have been prepared and characterized
by conventional chemical and physical measurements. Tetragonal
symmetry has been proposed for these complexes on the
basis of electronic spectral data. The various ligand field pp.rameteres
have been evaluated, wherever possible. The infrared spectral
studies indicate the S-N- bidentate nature of both ligands
Magneto-Spectral Studies on Some Trivalent Metal Complexes: Chromium, Iron and Cobalt Complexes Derived from 4-Benzylamidothiosemicarbazide and its Thiosemicarbazone.
Complexes of chromium(Ill), iron(lll) and cobalt(III) with
4-benzy lamidothiosemicarbazide (BTSC) and 1-( a-)fury 1-4-benzy lamidothiosemicarbazone
(FBTS) have been prepared and characterized
by conventional chemical and physical measurements. Tetragonal
symmetry has been proposed for these complexes on the
basis of electronic spectral data. The various ligand field pp.rameteres
have been evaluated, wherever possible. The infrared spectral
studies indicate the S-N- bidentate nature of both ligands
Welcome address
This is my privilege to welcome you all to the steel city of Jamshedpur, built by the greatest Indian pioneering industrialist Jamshedji Tata, its adjacent area abundant with valuable minerals and ores. At NML the first flowsheet
of a modern mineral beneficition plant was being attem-pted successfully in the early sixties. Thus, the seminar on crushing and grinding-practices, problems and prospects is a fitting tribute to the city and NML
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