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Plasma’s Profiles and Radial Electric Field in
Tokamak, by M. El Mouden, A. Dezairi, D. Saifaoui, M. Eddahby
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Helicity Fluctuation, Generation of Linking Number
and Effect on Resistivity,
by F. Spineanu, M. Vlad
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Influence of Losses of a Circular
Resonator on the Optical Bistability in a Laser Containing a
Saturable Absorber With Inhomogeneous Broadening, by S. Djabi,
M. Djabi
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Influence of Fluctuations of a Laser Light on the
Reflection of Atomic Mirror, by S. Al-Awfi, S. Bougouffa
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Photoemission Study of Pseudomorphic Growth of
Alpha-Sn on InSb Surfaces, by M. Abu-Samak
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Investigations of the Process of Selective Molecular
Photonic Replication in Coumarin 500 and its Relation to Other
Emission Processes, by F. F. Al-Adel, M. A. Dastageer
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The Specific Heat Bearing of the Manganese Oxides in
Double-Exchange Model, by E. Bîrsan
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The Effect of the Secondary Electron Production on
the Microwave Breakdown Phenomena, by M. Radmilović-Radjenović,
B. Radjenović
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TEM Investigation of Amorphization Kinetics Due to
Argon Implantation in GaAs, by K. Akmoum, M. Mimi
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Partitioning Study of Major and Trace Elements
Between Dissolved and Particulate Phases in Bouregreg River
(Morocco), by H. Bounouira, A. Choukri, S. Chakiri, O. K. Hakam,
Z. Bejjaji
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International Review
of PHYSICS - Papers
 Plasma’s
Profiles and Radial Electric Field in Tokamak
by M. El Mouden, A.
Dezairi, D. Saifaoui, M. Eddahby
Abstract - In this
paper, we have studied the contribution of the reversed magnetic shear
in reducing the anomalous transport in tokamak TEXT using both an
analytical approach and simulations. In particularly, we focus our study
on the contribution of the density, the temperature and the radial
electric field in the improvement of plasma confinement. The qualitative
comparison between our results and the authors [1]-[4],[15],[16] is
carried out..
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Plasma confinement, Tokamak, Anomalous transport, Magnetic shear,
Transport barrier, Particles diffusion, radial density, radial
temperature and radial electric field.
Helicity Fluctuation, Generation of Linking Number and Effect on
Resistivity
by F. Spineanu, M. Vlad
Abstract - The
energy of the stochastic magnetic field is bounded from below by a
topological quantity expressing the degree of linkage of the field
lines. When the bound is saturated one can assume that the storage of a
certain magnetic energy requires a minimal degree of topological
complexity. It is then possible to infer a connection between the
helicity content and the average curvature of the magnetic field lines.
The random curvature induce random drifts leading to an additional
dissipation and modified resistivity. Extensions to statistical
properties of linking are examined.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Magnetic reconnection, helicity, topological linking number,
plasma resistivity.
Abstract - Our work
concerns the study of the optical bistability of a laser containing a
saturable absorber of a circular resonator with an inhomogeneous
broadening. One will study theoretically the influence of the losses
resonators on the optical bistability by examining mainly the cases
where losses of the resonator depend on the position of the mode emitted
on frequency and on density of photons.
In the paper it is examined for each loss the influence of the physical
parameters of the laser containing a saturable absorber such as the
coefficient of saturation, pumping of the active medium, and absorbing
on the density of the photons.
A program in Matlab is elaborate in order to determine to determine the
effect of this optical bistability and to draw the curves representing
the density of the photons in the pumping function of the active medium.
One showed the effect of the optical bistability after analysis of the
linear stability of the obtained solutions
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Loss Of The Circular Resonator, Optical Bistability (OB), Laser
Containing A Saturable Absorber (LSA), Inhomogeneous Broadening.
Influence
of Fluctuations of a Laser Light on the Reflection of Atomic Mirror
by S. Al-Awfi, S. Bougouffa
Abstract - The
influence of phase fluctuations of a laser light on the atomic
reflection process of evanescent modes is investigated. This influence
is one of the main factors that limit the performance of the atomic
mirror action obstructing the ultimate goal of near-perfect coherent
reflection process. It is concluded that this influence plays a
significant role hence should be incorporated in the treatment of
quantum dynamics. By operating at low intensities, this influence can
only be minimized. We apply the expressions for the optical forces,
considering the phase fluctuations due to the laser light source. All
treatments of the phase diffusion model are deduced from the well-known
master equation. Different effects arising from application of various
phase fluctuations values are considered. These include enhancement of
the spontaneous force, and decreasing the dipole forces magnitudes. The
changes of the atom trajectories due to these effects are pointed out
and discussed.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Phase fluctuations, evanescent light, spontaneous and dipole
forces, optical potential, decay rate, Rabi frequency.
Photoemission
Study of Pseudomorphic Growth of Alpha-Sn on InSb Surfaces
by M. Abu-Samak
Abstract - A
comparison between the Sn-4d core level spectra obtained from
α-Sn(111)-lxl and α-Sn(100)-2x1 surfaces shows asymmetries justifiable
only by the presence of more components energetically split and ascribed
to the bulk-surface core level shift which is due to the in equivalence
of the two dimmer atoms. Fermi level valence band spectra been acquired
rotating the sample along the ГJ' direction. Dispersion valence band
states can be observed and it was in excellent agreement with an angular
resolved photoemission study of the valence band of InSb(100)-c(8x2)
surface, recently reported in literature.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Growth, tin, indium, x-ray photoelectron spectroscopy.
Investigations of the Process of Selective Molecular Photonic
Replication in Coumarin 500 and its Relation to Other Emission Processes
by F. F. Al-Adel, M. A.
Dastageer
Abstract - We
continue our investigations on the “Photonic Replication Process” in
color emitting molecules, using a wall of Coumarin 500 irradiated with
other photons than what we used previously ( Nd-Yag and He-Ne lasers).
The new colors were generated in a spectrofluorophotometer The present
experiments confirm the earlier results and provide additional
information about the relation between this process and other emission
processes.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Molecular photonic replication, Rayleigh scattering, Raman
scattering, image formation, laser excitation.
The
Specific Heat Bearing of the Manganese Oxides in Double-Exchange Model
by E.
Bîrsan
Abstract - Materials
that present the phenomenon of “colossal” magnetoresistance are
currently under much experimental investigation due to their potential
technological applications. Typical compounds that have this phenomenon
are ferromagnetic (FM) metallic oxides of the form R1−xAxMnO3 (where R =
La, Pr, Nd; A = Sr, Ca, Ba, Pb). In this paper we investigate the
specific heat behavior of these manganese oxides by Monte Carlo
simulations on the ferromagnetic Kondo lattice model. We present the
dependence of specific heat for square and simple cubic lattices with
temperature for different electron densities and Kondo lattice model
parameters.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Kondo lattice model, Specific heat, Strongly correlated electron
systems.
The Effect of the Secondary Electron Production on the Microwave
Breakdown Phenomena
by M.
Radmilović-Radjenović, B. Radjenović
Abstract - In the
present paper an attempt has been made to draw theoretically a
correlation between the secondary electron production and the breakdown
characteristics in argon, xenon and krypton discharges at microwave
frequencies. Calculations were performed by using Particle-in-Cell/Monte
Carlo collisions (PIC/MCC) code with both a constant and the energy
dependence of the yield per ion to evaluate the importance of the
secondary emission model in determining the microwave breakdown. In
addition, the obtained simulation results are compared with the
theoretical predictions based on the phenomenological method and the
breakdown criteria derived from the diffusion-controlled model. It was
found that adequate modification of the secondary emission model in the
PIC/MCC code can lead to a satisfactorily agreement between calculations
and theoretical predictions.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Microwave, breakdown, simulation, secondary electron prodcution.
TEM
Investigation of Amorphization Kinetics Due to Argon Implantation in
GaAs
by K. Akmoum, M. Mimi
Abstract - We
investigated the crystalline to amorphous transition induced by ion
implantation in GaAs using transmission electron microscopy (TEM).
Samples of GaAs were implanted at both 100 K and room temperature with
40 keV Ar+ and with doses between 2x1013 and 5x1014
ions/cm2. Experimental results are discussed in term of
the deposited energy density, which has been determined using Monté
Carlo simulation developed from IPROS. Values of 15 eV/mol [3.3x1023
eV/cm3] and 10 eV/mol [2.2x1023 eV/cm3]
have been obtained for the threshold energy damage density at room
temperature and low temperature implantation. The amorphization
mechanisms of GaAs under ion implantation are discussed in light of
these results.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Amorphization, Damage Energy, GaAs, Ion Implantation.
Partitioning
Study of Major and Trace Elements Between Dissolved and Particulate
Phases in Bouregreg River (Morocco)
by H. Bounouira, A.
Choukri, S. Chakiri, O. K. Hakam, Z. Bejjaji
Abstract - This
study focuses on the distribution of the major and trace elements in the
dissolved and particulate phases of the Bouregreg river in Morocco.
Water samples were analysed only by Inductively Coupled Plasma Mass
Spectrometry (ICP-MS); however the suspended matter samples have been
analyzed by ICP-MS and by Instrumental Neutron Activation Analysis (INAA).
Measurements were carried out on three phases (<0.22µm, [0.22-0.45µm]
and >0.45µm) obtained by filtration at the first time on a cellulose
nitrate filters of porosity 0,45µm and of diameter 47mm and second time
on filters of same nature but of porosity 0,22µm. The partitioning of
element concentrations between dissolved and particulate phases for 0.22
µm and 0.45 µm filter was studied for each site.
The concentrations of elements used in this study represent the mean
values of the concentrations measured during three campaigns of sampling
(winter 2004, summer 2004 and winter2005). The obtained results show
that: (i) As, Ba, Cd, Li, Mn, Rb, Sb, Sr, U and Zn are present in the
dissolved phase with concentrations superior to 50 % for the both
filters, (ii) Al, Ce, Dy, Eu, Fe, Ho, La, Lu, Nd, Tb, Th, Tm, Yb and Zr
are present in the particulate phase with concentrations superior to 50
% for the both filters and (iii) the concentrations distribution of Ca,
Cr, Cs, Cu, Fe, Hf, Ni, Pb, Pr, Sn, Ta, Ti, V, W and Y change the
tendency in the dissolved and particulate phases according to the used
filter.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Dissolved phase, Particulate phase, 0.45 µm filter, 0.22 filter,
Partitioning of major and trace elements, River water.
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