32,436 research outputs found
Eigenvalue spectrum for single particle in a spheroidal cavity: A Semiclassical approach
Following the semiclassical formalism of Strutinsky et al., we have obtained
the complete eigenvalue spectrum for a particle enclosed in an infinitely high
spheroidal cavity. Our spheroidal trace formula also reproduces the results of
a spherical billiard in the limit . Inclusion of repetition of each
family of the orbits with reference to the largest one significantly improves
the eigenvalues of sphere and an exact comparison with the quantum mechanical
results is observed upto the second decimal place for . The
contributions of the equatorial, the planar (in the axis of symmetry plane) and
the non-planar(3-Dimensional) orbits are obtained from the same trace formula
by using the appropriate conditions. The resulting eigenvalues compare very
well with the quantum mechanical eigenvalues at normal deformation. It is
interesting that the partial sum of equatorial orbits leads to eigenvalues with
maximum angular momentum projection, while the summing of planar orbits leads
to eigenvalues with except for L=1. The remaining quantum mechanical
eigenvalues are observed to arise from the 3-dimensional(3D) orbits. Very few
spurious eigenvalues arise in these partial sums. This result establishes the
important role of 3D orbits even at normal deformations.Comment: 17 pages, 7 ps figure
Dark Energy and the Statistical Study of the Observed Image Separations of the Multiply Imaged Systems in the CLASS Statistical Sample
The present day observations favour a universe which is flat, accelerated and
composed of matter (baryonic + dark) and of a negative
pressure component, usually referred to as dark energy or quintessence. The
Cosmic Lens All Sky Survey (CLASS), the largest radio-selected galactic mass
scale gravitational lens search project to date, has resulted in the largest
sample suitable for statistical analyses. In the work presented here, we
exploit observed image separations of the multiply imaged lensed radio sources
in the sample. We use two different tests: (1) image separation distribution
function of the lensed radio sources and (2)
{\dtheta}_{\mathrm{pred}} vs {\dtheta}_{\mathrm{obs}} as observational
tools to constrain the cosmological parameters and \Om. The results are
in concordance with the bounds imposed by other cosmological tests.Comment: 20 pages latex; Modified " Results and Discussion " section, new
references adde
Extreme value distributions for weakly correlated fitnesses in block model
We study the limit distribution of the largest fitness for two models of
weakly correlated and identically distributed random fitnesses. The correlated
fitness is given by a linear combination of a fixed number of independent
random variables drawn from a common parent distribution. We find that for
certain class of parent distributions, the extreme value distribution for
correlated random variables can be related either to one of the known limit
laws for independent variables or the parent distribution itself. For other
cases, new limiting distributions appear. The conditions under which these
results hold are identified.Comment: Expanded, added reference
Effect of Bio-degradation and Non Degradable Substances in Environment
Non-Biodegradable substances produce the greenhouse gasses, methane and carbon dioxide. Growing plants and trees on top of a landfill, a process known as ‘Phyto capping\u27, could reduce the production and release of these gasses. In certain parts of the world, it remains the most economical and simplest method of waste disposal. Biodegradation of organic matter in a landfill site occurs most rapidly when water comes into contact with the buried waste. An important step in the drive is to remove environmentally harmful materials from waste streams and drinking water. A synthetic clay known as swelling mica has the ability to separate ions of radium, a radioactive metal, from the water. The finding could have implications for radioactive and hazardous waste disposal, particularly in the cleanup of mill tailings left over from the processing of uranium for the nation\u27s nuclear industry. The tailings contain radium and heavy metals
Path integrals and wavepacket evolution for damped mechanical systems
Damped mechanical systems with various forms of damping are quantized using
the path integral formalism. In particular, we obtain the path integral kernel
for the linearly damped harmonic oscillator and a particle in a uniform
gravitational field with linearly or quadratically damped motion. In each case,
we study the evolution of Gaussian wavepackets and discuss the characteristic
features that help us distinguish between different types of damping. For
quadratic damping, we show that the action and equation of motion of such a
system has a connection with the zero dimensional version of a currently
popular scalar field theory. Furthermore we demonstrate that the equation of
motion (for quadratic damping) can be identified as a geodesic equation in a
fictitious two-dimensional space.Comment: 15 pages, 6 figure
Generation of helical magnetic fields from inflation
The generation of helical magnetic fields during single field inflation due
to an axial coupling of the electromagnetic field to the inflaton is discussed.
We find that such a coupling always leads to a blue spectrum of magnetic fields
during slow roll inflation. Though the helical magnetic fields further evolve
during the inverse cascade in the radiation era after inflation, we conclude
that the magnetic fields generated by such an axial coupling can not lead to
observed field strength on cosmologically relevant scales.Comment: 4 pages, 1 figure; Contribution to the proceedings of the
International Conference on Gravitation and Cosmology (ICGC), Goa, India,
December, 201
Introduction About Child Health Status in India
Child health is a multifaceted problem which is directly linked to a large extent to mother’s health conditions, safe delivery conditions, socio-economic conditions of the family and the health care system. Over the time, the nation has implemented a number of child-centric programs, the poor health status of women and children in terms of high mortality and morbidity was another health priority in this country. Health facilities like hospitals and health centers were established for providing Maternal and Child Healthcare through antenatal, intra-natal and postnatal services. In addition, a number of special programs and schemes like immunization against vaccine-preventable diseases, nutrition interventions like iron and folic acid distribution and vitamin A supplementation, diarrheal disease control through Oral Rehydration Therapy (ORT), Acute Respiratory Infection (ARI) control program etc. were implemented over the past. In order to, ensure maximum benefit from these programs and to provide services in an integrated manner to these vulnerable groups strong monitoring system required
Design of a Drivetrain for Sae Baja Racing Off-Road Vehicle
With growing time, the participation of the students in SAE BAJA is increasing year by year. The vehicle\u27s performance is highly dependent on the installation and appropriate use of Drivetrain components. Drivetrain includes powertrain (prime mover i.e. engine/motor) and transmission components (gearbox, shafts etc). Therefore, Drivetrain is also called as the driving force of any vehicle. The proper design of Drivetrain is thus a part and parcel for any vehicle. The lack of literature available for a optimize design of Drivetrain makes it a hard nut to crack for the students who don\u27t have any past experience. Thus there is a need for some source by which the students can learn to design the Drivetrain for SAE BAJA. The engine vibration is another aspect which is needed to be considered. NVH consideration is another deciding parameter in BAJA vehicle\u27s performance which if neglected could leads to lethal results. Therefore proper installation of engine mounts is required according to the need.
Thus, this segment aims at developing the Drivetrain for BAJA vehicles which can boost up the performance of the vehicle. Properly use of a powertrain and transmission components for a vehicle along with the calculations according to the need will be discussed in detail. This segment also aims at developing the conceptual understanding of the performance parameters of a BAJA vehicle among the student which will be helpful in their academic curriculum as wel
On Combining Lensing Shear Information from Multiple Filters
We consider the possible gain in the measurement of lensing shear from
imaging data in multiple filters. Galaxy shapes may differ significantly across
filters, so that the same galaxy offers multiple samples of the shear. On the
other extreme, if galaxy shapes are identical in different filters, one can
combine them to improve the signal-to-noise and thus increase the effective
number density of faint, high redshift galaxies. We use the GOODS dataset to
test these scenarios by calculating the covariance matrix of galaxy
ellipticities in four visual filters (B,V,i,z). We find that galaxy shapes are
highly correlated, and estimate the gain in galaxy number density by combining
their shapes.Comment: 8 pages, no figures, submitted to JCA
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