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International Review
of PHYSICS - Papers
Vol.
3. n. 3, pp.
150-155
Abstract
-
In this paper, the propagation of ion-acoustic waves in
electron-positron-ion magnetized plasmas is analyzed, numerically. The
effect of positron density on the amplitude of ion-acoustic waves is
also studied. Corresponding to a fixed positron density, it is shown
that the speed of the wave can change in certain parameter range.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
52.35.Mw, 52.35.Sb, 52.25.Xz, 52.27.Aj, 52.35.Fp.
 Production
Cross-Sections of Charged Goldstones Bosons in (e+ ,e- ) Collider
by T. A. El-Azim, H.T.I.
Abdel-Karim
Vol.
3. n. 3, pp.
156-160
Abstract - The total
cross-sections for the charged Goldstones and H0 -bosons production have
been calculated by assuming that the interactions occur through
different propagators. The production cross-sections have been studied
in the minimal super symmetric standard model (MSSM), via e+e-
→G+G-H0i. At an incoming
energy s=290 GeV, the process e+e-
→Z0→G+G-H0i
could be detected with a
reasonable cross-section of about 105 fb for i = 2 and 104
fb for i =1.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Goldstones Bosons, production Cross-Sections, broken symmetry,
standard model.
Vol.
3. n. 3, pp.
161-165
Abstract
-
This paper contains a simple theoretical prediction
of the electrical breakdown characteristics of the rf capacitive plasma
source. The Kihara equation has been applied in order to determine the
breakdown voltage in helium rf microdischarges. It was found that the
Kihara equation, with modified molecular constants, describes the
breakdown process well even for gaps of the order of a few millimeters.
The agreement between theory and the available experimental data over a
wide range of parameters verifies the correctness of the approach. In
addition, theoretically determined breakdown voltages involving
gas-adjustable parameters are supported by the PIC/MCC simulation
results.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Breakdown, microdischarges.
Vol.
3. n. 3, pp.
166-171
Abstract
-
There are a number of unconventional methods which can be used to improve
the performance of earthing systems in highly resistive soil
environments. One of them is the use of soil enhanced earth electrodes.
The performance analysis of such unconventional earthing system is not a
simple task. In this paper a numerical model algorithm for the
performance analysis of unconventional earthing system has being
presented. The method involves the use of electrostatic boundary
integral formulation which is based on the dual discretization and the
method of moment technique. The results obtained from this model were
compared with the analytical version whose formulation was also
presented for validity.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Unconventional, Enhanced, Simulation, Electrodes,
Electrostatic, Earthing, Hazard.
New II-Conjugated Donor Derivative of Oligothiophene in Numerical
Investigation of Organic Solar Cell
by S. Bouchekouf, B.
Marir, M. Benabbas-Marir
Vol.
3. n. 3, pp.
172-178
Abstract - We
propose in this investigation, contrary to literature where the results
are only experimental, a method of simulation based on the resolution of
equations of currents (continuities) for an organic solar
heterostructure of oligomere/small molecule type based on a new
π-conjugated donor derived from oligothiophene with the perylene
derivative (D5P) like acceptor. This study uses a method of calculation
of the photocurrent delivered by the cell from equations of continuities
and currents by analogy to the phenomena of charges transport according
to the model of a heterojunction n/p.
The principal photovoltaic parameters of this structure are calculated
by the simulation of equation I(V), under illumination AM1. 5.
The optimization of donor layer thickness shows clearly that the best
results are obtained with the finest structures, the conversion
efficiency increases from 0.82% to 1.19%. With the results obtained, we
can consider the cells of heterojunction type based on these new donors
resulting from oligothiophenes among most effective obtained from oligo-
and polytyiophenes.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Organic Solar Cell, Derivative of Oligothiophene, Photocurrent,
Equation of Continuity.
Modeling and Analysis in Large Hyperelastic Deformation of the Stress
Distribution in an Atherosclerotic Plaque
by Bouaricha Amor,
Haiahem Ammar, Bou-Said Benyebka
Vol.
3. n. 3, pp.
179-186
Abstract - Despite
the current extensive development of medical imaging, clinicians are
still not able to diagnose the vulnerability of an atherosclerotic
plaque and to prevent its rupture with sufficient precision. The rupture
of plaque is the main reason for the different presentations of cardiac,
cerebral, renal or lower limb ischemia. Cyclical and pulsating
properties of blood flow can lead to a rupture of the vessel by fatigue.
This rupture is often linked to stress concentration (SC) resulting from
the vessel geometry and blood pulse. Amplitude and topography of the
concentrated stress are linked to blood pressure, stenosis rate (SR) and
to the shape and volume of the plaque. The mechanical properties of the
plaque components as well as the thickness of the fibrous cap (FC) and
the type of remodeling are also factors which can influence the
stability of the atherosclerosis plaque. To provide markers that can
help in the diagnosis of vulnerable plaque, the purpose of this study is
to model and analyze the artery, using the finite element method with
the large deformation assumption, to determine the stress field
generated during the cardiac cycle. Amplitude and location of the SC are
determined for every parameter considered as a vulnerability factor.The
various simulations on a model of atherosclerotic plaque in an eccentric
artery case with stenosis demonstrate that thinning of the fibrous cap,
the increase of the angle (a characteristic of a constrictive
remodeling) and the lack of rigidity of the lipidic core (LC), as well
as increase of its volume, decrease individually the plaque resistance
to rupture. The increase of the stenosis rate, coupled with other
geometrical factors, increases the magnitude of the stress, which
reaches its maximum for SR = 40 %.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Atherosclerosis, Vulnerability, Stress Concentration, Plaque
Rupture.
Electret
Matrix Sensor for Measurement of Dynamic Pressure Distributions
by Simo Ahtiainen,
Hannu Olkkonen, Markku Tiitta, P. Heikkinen
Vol.
3. n. 3, pp.
187-189
Abstract - This work
presents a new approach for measurement of dynamic pressure and force
distributions based on a thin-film electret matrix sensor (EMS). The EMS
is constructed from the electret film, which is coated with narrow
strips of transversally conducting material on both sides of it. On top
of the foil the slices are in vertical and on bottom in horizontal
directions. At the edge of the sensor the strips are connected to the
multiplexer and differential amplifier arrangement. The main advantage
in EMS is essential reduction in wiring compared with single sensors.
The new sensor meshing technique has wide range of applications in
medical and industrial fields. Matrix and each pixel sizes and covering
material can be tailored for specific purposes. However, we observed
that a crosstalk effect between channels intensifies when the size of
the EMS is decreased.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Electret, Pressure Distribution, Point Spread Function, Dynamic
System Control.
Numerical
Simulation of Geometrical Constraints of Topographical Surfaces Using
Differential Geometry
by Mohammedi
Ferhat
Vol.
3. n. 3, pp.
190-194
Abstract - By applying differential
geometry to analogue models developed such a model is calculated for the
geometrical shape of the object under investigation and for deformation
and / or motions as assumed or estimated. We demonstrate that the
geometry of such models can be completely and objectively quantified.
This quantification then allows for comparison of such models to
measured field data and supplants the use of the high sensitivity of
interferences effect permits quantitative analysis in the small- strain
domain. We discuss the theory used and obtain general expressions for
evaluation of slope and curvature. . The feasibility and effectiveness
of the proposed method is demonstrated by computer simulation.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Interferometry, Topography Surfaces, Differential Geometry,
Modeling Images Optically.
Adaptation
of Radiological Supply HV / HF for Medical Use
by M. Rachedi, M.
Bourahla
Vol.
3. n. 3, pp.
195-200
Abstract - Currently, the most widely
used techniques in hospitals for medical diagnosis are radiology and
scanner. The X ray offer through images, the information needed to treat
the patient. The sharpness of the image is closely linked to the
stability of the supply voltage tube where the requirement for a
command. The cost, volume and high technique equipment, are the
parameters for qualification and performance symbols adopted by the
research today. This work presents a method of controlling the supply
voltage of an X ray tube, as well as its strength to face external
shocks and changes in the system parameters. This method is based on the
technique of control by fuzzy logic that meets the needs cited by the
specifications for this type of application.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
High Voltage Generator, Transformer HF /HV, DC-DC Converter, X ray
Tube.
Unsteady
Flow of a Dusty Visco-Elastic Fluid Between Two Parallel Plates
by T. Nirmala, B.
J. Gireesha, C. S. Bagewadi
Vol.
3. n. 3, pp.
201-206
Abstract - The Unsteady laminar flow of
an electrically conducting viscous incompressible fluid between two
infinitely extended non-conducting moving parallel plates under the
influence of a uniform magnetic field has been considered. The flow is
due to the influence of time dependent pressure gradient, the motion of
plates and due to the influence of a uniform magnetic field. The
velocity profiles for conducting fluid and non-conducting dust particles
have been determined with the help of Laplace Transform technique. The
expressions for skin-friction at lower and upper plate are obtained.
Finally the effect of strength of magnetic field on velocity profiles at
fixed time has been discussed.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Frenet Frame Field
System, Parallel Plates, Dusty Fluid; Velocity Of Dust Phase And Fluid
Phase, Conducting Dusty Fluid, Magnetic Field.
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