28,982 research outputs found
Low Voltage Floating Gate MOS Transistor Based Four-Quadrant Multiplier
This paper presents a four-quadrant multiplier based on square-law characteristic of floating gate MOSFET (FGMOS) in saturation region. The proposed circuit uses square-difference identity and the differential voltage squarer proposed by Gupta et al. to implement the multiplication function. The proposed multiplier employs eight FGMOS transistors and two resistors only. The FGMOS implementation of the multiplier allows low voltage operation, reduced power consumption and minimum transistor count. The second order effects caused due to mobility degradation, component mismatch and temperature variations are discussed. Performance of the proposed circuit is verified at ±0.75 V in TSMC 0.18 µm CMOS, BSIM3 and Level 49 technology by using Cadence Spectre simulator
Where we stand on structure dependence of ISGMR in the Zr-Mo region: Implications on K_\infty
Isoscalar giant resonances, being the archetypal forms of collective nuclear
behavior, have been studied extensively for decades with the goal of
constraining bulk nuclear properties of the equation of state, as well as for
modeling dynamical behaviors within stellar environments. An important such
mode is the isoscalar electric giant monopole resonance (ISGMR) that can be
understood as a radially symmetric density vibration within the saturated
nuclear volume. The field has a few key open questions, which have been
proposed and remain unresolved. One of the more provocative questions is the
extra high-energy strength in the region, which manifested in
large percentages of the sum rule in Zr and Mo above the
main ISGMR peak. The purpose of this article is to introduce these questions
within the context of experimental investigations into the phenomena in the
zirconium and molybdenum isotopic chains, and to address, via a discussion of
previously published and preliminary results, the implications of recent
experimental efforts on extraction of the nuclear incompressibility from this
data.Comment: 9 pages, 7 figures, invited to be submitted to a special issue of
EPJA honoring Prof. P. F. Bortigno
Raman anomalies as signatures of pressure induced electronic topological and structural transitions in black phosphorus: Experiments and Theory
We report high pressure Raman experiments of Black phosphorus up to 24 GPa.
The line widths of first order Raman modes A, B and A of the
orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density
functional analysis reveals that this is associated with the anomalies in
electron-phonon coupling at the semiconductor to topological insulator
transition through inversion of valence and conduction bands marking a change
from trivial to nontrivial electronic topology. The frequencies of B and
A modes become anomalous in the rhombohedral phase at 7.4 GPa, and new
modes appearing in the rhombohedral phase show anomalous softening with
pressure. This is shown to originate from unusual structural evolution of black
phosphorous with pressure, based on first-principles theoretical analysis.Comment: 13pages, 12figure
Critical Dynamics of the Hybrid Monte Carlo Algorithm
We investigate the critical dynamics of the Hybrid Monte Carlo algorithm
approaching the chiral limit of standard Wilson fermions. Our observations are
based on time series of lengths O(5000) for a variety of observables. The
lattice sizes are 16^3 x 32 and 24^3 x 40. We work at beta=5.6, and
kappa=0.156, 0.157, 0.1575, 0.158, with 0.83 > m_pi/m_rho > 0.55. We find
surprisingly small integrated autocorrelation times for local and extended
observables. The dynamical critical exponent of the exponential
autocorrelation time is compatible with 2. We estimate the total computational
effort to scale between V^2 and V^2.25 towards the chiral limit.Comment: 3 pages, Latex with espcrc2.sty and postscript figures, Talk given at
Lattice 9
Phonons and Anisotropic Thermal Expansion Behaviour of NiX (X = S, Se, Te)
Metal Chalcogenides have been known for important technological applications
and have attracted continuous interest in their structure, electronic, thermal
and transport properties. Here we present first principles calculations of the
vibrational and thermodynamic properties of NiX (X = S, Se, Te) compounds along
with inelastic neutron scattering measurements of the phonon spectrum in NiSe.
The measured phonon spectrum is in very good agreement with the computed
result. We also report the measurement of thermal expansion behavior of NiSe
using X-ray diffraction from 13 K to 300 K. The change in the hexagonal c
lattice parameter in NiSe is considerably greater as compared to a parameter.
The ab-initio calculated anisotropic Gr\"uneisen parameters of the different
phonon modes in all the chalcogenides along with the elastic constants are used
to compute anisotropic thermal expansion behviour, which is found in good
agreement with experiments. The displacement pattern of phonons indicate that
difference in amplitudes of Ni and X atoms follow the anisotropy of thermal
expansion behavior along c- and a-axis.Comment: 21 Pages, 9 Figure
The continuum limit of quark number susceptibilities
We report the continuum limit of quark number susceptibilities in quenched
QCD. Deviations from ideal gas behaviour at temperature T increase as the
lattice spacing is decreased from T/4 to T/6, but a further decrease seems to
have very little effect. The measured susceptibilities are 20% lower than the
ideal gas values, and also 10% below the hard thermal loop (HTL) results. The
off-diagonal susceptibility is several orders of magnitude smaller than the HTL
results. We verify a strong correlation between the lowest screening mass and
the susceptibility. We also show that the quark number susceptibilities give a
reasonable account of the Wroblewski parameter, which measures the strangeness
yield in a heavy-ion collision.Comment: 8 pages, 5 figure
Exploitation of juveniles of the spinycheek grouper, Epinephelus diacanthus by multiday trawlers along Dakshina Kannada coast
The juveniles in the size range 9-24 cm are in
sizeable quantities during October - May at
Mangalore and Malpe landing centres of Dakshina
Kannada coast. The present study is undertaken
to highlight the magnitude of the exploitation of
the juveniles of the Spinycheek grouper.
Epinephelus diacanthus by trawlers along the
Dakshina Kannada coast and its impact on the
stock with a brief description on its biology. This
species is known to grow to a large size and
supports a fishery of some magnitude in other
parts of the Indian coast. The results presented here are based on the data collected on the landing of the species at Mangalore and Malpe during 1988/'89 - 1993-'9
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