3,645 research outputs found
Mass independence and asymmetry of the reaction: Multi-fragmentation as an example
We present our recent results on the fragmentation by varying the mass
asymmetry of the reaction between 0.2 and 0.7 at an incident energy of 250
MeV/nucleon. For the present study, the total mass of the system is kept
constant (ATOT = 152) and mass asymmetry of the reaction is defined by the
asymmetry parameter (? = | (AT - AP)/(AT + AP) |). The measured distributions
are shown as a function of the total charge of all projectile fragments,
Zbound. We see an interesting outcome for rise and fall in the production of
intermediate mass fragments (IMFs) for large asymmetric colliding nuclei. This
trend, however, is completely missing for large asymmetric nuclei. Therefore,
experiments are needed to verify this prediction
Effect of the symmetry energy on nuclear stopping and its relation to the production of light charged fragments
We present a complete systematics (excitation function, impact parameter,
system size, isospin asymmetry, and equations of state dependences) of global
stopping and fragment production for heavy-ion reactions in the energy range
between 50 and 1000 MeV/nucleon in the presence of symmetry energy and an
isospin-dependent cross section. It is observed that the degree of stopping
depends weakly on the symmetry energy and strongly on the isospin-dependent
cross section. However, the symmetry energy and isospin-dependent cross section
has an effect of the order of more than 10% on the emission of light charged
particles (LCP's). It means that nuclear stopping and LCP's can be used as a
tool to get the information of an isospin-dependent cross section.
Interestingly, the LCP's emission in the presence of symmetry energy is found
to be highly correlated with the global stopping.Comment: 16 pages, 8 figure
Arithmetic and growth of periodic orbits
We give necessary and sufficient conditions for a sequence to be exactly
realizable as the sequence of numbers of periodic points in a dynamical system.
Using these conditions, we show that no non-constant polynomial is realizable,
and give some conditions on realizable binary recurrence sequences. Realization
in rate is always possible for sufficiently rapidly-growing sequences, and is
never possible for slowly-growing sequences. Finally, we discuss the
relationship between the growth rate of periodic points and the growth rate of
points with specified least period.Comment: Revised version with new content; to appear in J.Integer Sequence
Scaling in Late Stage Spinodal Decomposition with Quenched Disorder
We study the late stages of spinodal decomposition in a Ginzburg-Landau mean
field model with quenched disorder. Random spatial dependence in the coupling
constants is introduced to model the quenched disorder. The effect of the
disorder on the scaling of the structure factor and on the domain growth is
investigated in both the zero temperature limit and at finite temperature. In
particular, we find that at zero temperature the domain size, , scales
with the amplitude, , of the quenched disorder as with and in two
dimensions. We show that , where is the
Lifshitz-Slyosov exponent. At finite temperature, this simple scaling is not
observed and we suggest that the scaling also depends on temperature and .
We discuss these results in the context of Monte Carlo and cell dynamical
models for phase separation in systems with quenched disorder, and propose that
in a Monte Carlo simulation the concentration of impurities, , is related to
by .Comment: RevTex manuscript 5 pages and 5 figures (obtained upon request via
email [email protected]
Experimental Investigation on Surface Roughness in Electrical Discharge Turning of Ti-6Al-4V Alloy
This study presents a novel EDM turning process specially designed and developed to generate precise cylindrical forms on hard and difficult-to-machine materials. For this purpose, a specially designed turning spindle is used. The spindle was mounted on a conventional die-sinking EDM machine to rotate the workpiece. Axially symmetric parts can be manufactured by feeding the shaped tool into the rotating workpiece. In this way an axisymmetric workpiece can be made with small tools at both macro and micro levels. Effects of machining parameters, such as the current, pulse-on time, rotational speed, flushing pressure, and duty factor, on the surface roughness of Ti-6Al-4V alloy in electrical discharge turning were investigated. Taguchi\u27s design of experiment technique was used. Analysis of variance and regression analysis were performed on experimental data. The signal-to-noise ratio analysis was employed to find the optimal condition
A Singular Perturbation Analysis for \\Unstable Systems with Convective Nonlinearity
We use a singular perturbation method to study the interface dynamics of a
non-conserved order parameter (NCOP) system, of the reaction-diffusion type,
for the case where an external bias field or convection is present. We find
that this method, developed by Kawasaki, Yalabik and Gunton for the
time-dependant Ginzburg-Landau equation and used successfully on other NCOP
systems, breaks down for our system when the strength of bias/convection gets
large enough.Comment: 5 pages, PostScript forma
Relevance of sociodemographic characteristics in care of HIV reactive pregnant women in the context of upscaled antiretrovial therapy in India
Background: The burden of HIV and AIDS comes with social, monetary and health related consequences. HIV is reported to be a pandemic, but the maximum burden of the disease is in the low and middle income \ countries. In obstetric context, sociodemographic factors influence health seeking, compliance and adherence to the advised regimen. These determine vertical transmission. Present study was undertaken to study the demographic characteristics among pregnant and postpartum HIV positive women, to study the high risk obstetric conditions, morbidities and obstetric outcome, among the women, to study the neonatal outcomes among HIV reactive women and to study the postnatal choices and compliance in these women.Methods: The study was conducted after approval from the institutional ethics committee. All antenatal patients delivering at the institute in the one and a half year of study duration, who consented to be a part of the study, were enrolled in the study. The mother-baby pair was followed up for six weeks postpartum.Results: Eighty patients formed the study cohort as per the inclusion criteria. 44% belonged to the age group of 26-30 years. 56.2% had attended up to secondary schooling, 55% belonged to class III of the Kuppuswamy socio-economic class, 96.2% were married. 91.2% were homemakers. 41.8% spouses were seropositive, 25.3% spouses were not willing to be tested. 75% were registered pregnancies out of which 56% had registered before 20 weeks of gestation. 25% of neonates weighed between 2.7-2.9 kg closely followed by those more than 3 kg. Fifty-four patients opted for top feeding (66.7%). Seven mother-baby pair did not follow-up.Conclusions: Social class and educational status play a vital role in establishing awareness and ensuring the antenatal care and compliance. Empathetic, inclusive and responsive by health care providers in convincing women to get tested goes a long way
Quantum mechanical photon-count formula derived by entangled state representation
By introducing the thermo entangled state representation, we derived four new
photocount distribution formulas for a given density operator of light field.
It is shown that these new formulas, which is convenient to calculate the
photocount, can be expressed as such integrations over Laguree-Gaussian
function with characteristic function, Wigner function, Q-function, and
P-function, respectively.Comment: 5 pages, no figur
A comparative study of model ingredients: fragmentation in heavy-ion collisions using quantum molecular dynamics model
We aim to understand the role of NN cross-sections, equation of state as well
as different model ingredients such as width of Gaussian, clusterisation range
and different clusterisation algorithms in multifragmentation using quantum
molecular dynamics model. We notice that all model ingredients have sizable
effect on the fragment pattern.Comment: 12 Pages, 4 Figure
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