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International Review
of PHYSICS - Papers
Atom-Field
Entanglement between Conducting Plates
by S. A. Al-Awfi , E. M.
Khalil
Abstract - The
entanglement between atom and electromagnetic field inside perfectly
conducting parallel plates is investigated. The cavity modes are firstly
quantized, allowing the effective Hamiltonian to be evaluated for an
electric dipole located at an arbitrary point. Some statistical aspect
of this effective Hamiltonian such as the temporal evolution of the
atomic inversion and the von Neumann entropy are presented. Theses
aspects are sensitive to the changes due to the distance between the two
plates, which controls the number of the propagating of the cavity
modes. We have studied the atomic inversion and we introduced that the
atom still in maximal entangled state when the distance between the
plates is large. We have used the von Neumann entropy to measure the
degree of that entanglement. The results show that the effect of the
distance between the plates changes the quasi-period of the field
entropy and hence the entanglement process.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Atomic inversion, Maximal entangled states, degree of
entanglement.
Electron
Loss to the Continuum in the Projectile Ionization for Positronium –
Helium Atom Collision
by S. Roy, C. Sinha
Abstract - The
dynamics of the electron loss to the continuum (ELC) from the light
neutral projectile positronium (Ps) atom in collision with the He atom
is studied in the framework of the post collisional Coulomb Distorted
Eikonal Approximation (CDEA). Both the fully differential (TDCS) and the
double differential (DDCS) cross sections are investigated in the
intermediate and high incident energies. Results are compared with the
existing experiment and other theories, where possible.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Positronium (Ps), ELC, Coulomb distorted Eikonal Approximation (CDEA),
DDCS.
Abstract
-
In this
manuscript we study the Dirac action in the presence of the
Ramond-Ramond (R-R) potentials as gauge fields. Therefore, for the R-R
field Aμ1… μp+1 we
identify the corresponding fermion with an extended p-dimensional
object, which we call it Fp-brane. Conservation of the tensor currents,
associated to these fermionic branes, imposes an external tensor
current. This external current enables us to study the R-R fields and
their Hodge dual fields as independent degrees of freedom. We observe
that an Fp-brane should live with its dual brane, i.e. F(d-p-2)-brane.
The gauge symmetry and some other properties of a system of an Fp-brane
and its dual object will be discussed.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Dirac action; R-R fields; Branes.
Abstract
-
The proper quantum plasma treatment of the electron gas in degenerate
stars such as white dwarfs provides an additional quantum contribution
to the electron pressure. The additional pressure term modifies the
equation for hydrostatic equilibrium, resulting in the quantum modified
Lane-Emden equation for polytropic equation of states. The additional
pressure term also modifies the expression for the limiting
Chandrasekhar mass of white dwarfs. An approximate solution is derived
of the quantum modified Lane-Emden equation for general polytropic
indices, and it is demonstrated that the quantum corrections reduce the
standard Chandrasekhar mass and enhance the white dwarf radius by
negligibly small values only.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
quantum plasmas, white dwarfs, equation of state.
Estimation
of the Vertical Total Electron Content
by C. Chaib, Z. Souar,
M. Mimi
Abstract - An
approach to the study of the ionosphere is developed and described in
this paper. It uses the positioning of a known point based in the
National Center of Space Techniques (CNTS) of Arzew (Algeria).
The purpose is the study of the vertical total electron content (TEC)
using code of signal GPS measurements. For that two methods are used:
dual-frequency and a method based on the model of Klobuchar. To
eliminate possible errors of the satellite, the receiver and the
ionosphere, we used the method of dual-frequency from which the absolute
estimates of the ionosphere are given. For a GPS receiver alone, we can
use the model of Klobuchar to determine the vertical time on the code
transmitted by the signal L1. A comparison between both used models is
made to choose that which characterizes best the ionospheric effect.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
GPS; ionosphere; TEC ; modelling; model of Klobuchar;
dual-frequency model.
On
Appling Gaussian Wavelet and Spectral Analysis for Pattern Recognition
to Capture Normal Breath Sounds
by F. Ayari, A. T.
Alouani, M. Ksouri
Abstract -
This paper describes the investigation of normal lung sounds analysis to
found a consistent bank of information on chest wall breath sounds from
healthy subjects. In fact, the desire for an objective method to store
these sounds information was the impetus for development of the field of
computer-assisted mapping of lung sounds. Lung sound signals are
transferred to a computer to be analyzed and patterned. Phonopneumograms
allow an objective classification of breath lung sounds in time and
frequency domain. So a new technique based on Gaussian wavelet transform
processing of respiratory cycles decomposition is proposed. Numerical
results prove that the Gaussian wavelet transform is a power tool for
denoising and examine the singular natures of normal lung sounds
signals. Some features of normal lung breath sounds can be identified
using computerized lung sounds examination by a spectral analysis, this
leads to an automatic classification of these sounds.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Template, Normal lung sounds, wavelet, spectral analysis.
Research
Note: Early Cancer Detection with Wire Mesh Collimator Gamma Camera
by M. I. Saripan,
W. H. M. Saad, M. A. Mahdi, A. R. Ramli
Abstract -
This paper presents the preliminary results on the early cancer
detection using wire mesh collimator gamma camera. The limitation of the
conventional multihole collimator is the lacked of sensitivity as a
trade-off for obtaining better resolution, hence less photon are
registered by the sequential event. This inherent property of the
conventional system reduced the possibility of maximum tumour
recognition. The wire-mesh collimator is a new concept of
semi-collimator and semi-coded aperture. With such a flexible structure,
one may choose to have a good resolution or a good sensitivity or any
configuration in between. In this paper, we investigate the performance
of the wire-mesh collimator to detect a lesion. The imaging environment
is modeled using Monte Carlo N-Particle Transport Code version 5
(MCNP5). The results imply that the wire mesh collimator has better
sensitivity and recorded more counts than the conventional collimator.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Early Cancer Detection, Multihole Collimator, Wire Mesh
Collimator, Gamma Camera.
Airborne
Hyperspectral Imaging for Mapping of Pavement Cracks on Malaysian
Highways
by J. Hj. Kamaruzaman,
Y. Norsuzila
Abstract -
Highway development and the increase of multiple
modes of transportation have encourage the needs of highway management
and maintenance parallel to a developed country. In Malaysia, the North
South Express Highway (PLUS) is regularly maintaining their highways,
especially the pavement cracks. Therefore, the latest and accurate
information is required on pavement cracks for the maintenance and the
management of the highway. A study was therefore conducted to identify
and map pavement cracks on Bukit Lanjan PLUS highway using an airborne
imaging system to save time, energy and cost. Airborne digital image
from UPM - Aeroscan Precision (M) Sdn. Bhd. which was acquired on 19th
February 2004 was utilized in this study. After processing using ENVI
software version 4.0, results indicated that no cracks were mapped using
this sensor. The study implies that future pavement crack mapping should
be done using a higher resolution airborne data of less than 1m.
Copyright © 2008 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Pavement, Cracks, Highway, Airborne, Hyperspectral, Imaging.
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