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International Review
of PHYSICS - Papers
Vol. 3. n. 5, pp. 256-262
Abstract
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We investigated the effect of the warm inhomogeneous movable plasma in a
cylindrical waveguide. Analytical calculations are performed to find the
plasma dielectric tensor, which leads to apply the boundary conditions
at the plasma-conductor interface. In addition we derive the dispersion
equations, which describes E- and H-waves, hence the damping rate of
these waves. The necessary condition for the field stability in the
waveguide and amplification coefficient for E- wave is also obtained.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Waves Excitation, Waveguide Filled with Warm Inhomogeneous Movable
Plasma.
 Static
and Dynamic Mechanical Properties of Cross-Linked
Poly(Tripropyleneglycoldiacrylate)/Liquid Crystal Blends
by Abdelkader Berrayah,
Ulrich Maschke
Vol. 3. n. 5, pp. 263-267
Abstract - This
investigation reports on static and dynamic mechanical properties of
cross-linked Poly(tripropyleneglycoldiacrylate) (Poly-TPGDA) networks,
elaborated via radical polymerization processes induced by Ultraviolet
(UV) radiation. The presence of low molecular weight liquid crystal (LC)
molecules in the polymer matrix modifies the dynamic and static
mechanical behavior of the obtained composite materials.
The storage modulus decreases with increasing LC content in the
temperature range from T=25°C to -15°C, due to the plasticizing effect
induced by the presence of low molecular weight LC in the polymer
matrix. In the case of polymer/LC blends with more than 30 weight
(wt.)-% LC and for temperatures lower than -15°C, a reinforcement effect
could be seen, leading to a change of the shape of the decreasing
curves. This phenomenon interferes with the plasticizing effect which
himself governs the whole mechanical behavior of the cured polymer/LC
system. A sort of competition takes place especially for temperatures
lower than -75°C, so that the storage modulus increases or remains
constant between 20 and 60 wt.-% LC.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords: Polymer
network, Acrylate, Liquid crystal, UV irradiation, Young modulus,
Storage modulus.
Abstract
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This article is devoted to the study of the behavior of the charged
particles in a glow discharge in continuous mode with low pressure at
ambient temperature in argon. The objective is to determine by modeling
in one and two dimensional (1D and 2D) Cartesian geometrical
configuration the electric properties of the glow discharge maintained
by a constant source term between two plan electrodes. The model used in
this work belongs to the fluid models group; it is an electric model
based on the first three moment’s resolution of Boltzmann’s equation
coupled in a self-coherent way with the Poisson equation. Spatial
distribution of electrons-ions densities, the electric field, the
potential and the energy of the electrons in stationary state are
presented in this work.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Glow discharge, Boltzmann’s equation, Electron temperature,
Electron diffusivity, Poisson's equation.
Abstract
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GaAs metal semiconductor field effect transistors are widely used for
microwave and digital applications because of their superior high
frequency characteristics. A variety of models used to simulate the GaAs
MESFET characteristics, it has been observed that the drain current and
small signal parameters of the GaAs field effect transistor, for
instance transconductance and output conductance are sensitive to the
temperature, and there for it is important to take in to account the
effect of temperature on these parameters. Using a recent model , we
have investigated the effect of the temperature on the I-V
characteristics and small signal parameters. Our results show that the
drain current and the transconductance decreases with increasing the
temperature which are in excellent agreement with the published
experimental results.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
GaAs MESFET, Microwaves ,Temperature, Transconductance.
Vol. 3. n. 5, pp. 278-288
Abstract
-
In this work a “breath” model for bio-solitons is presented, in which some
damaged solitons interact with surround health solitons to allow their
sick states to return back to the health states. For describing this
breath model, a formalism of non-linear Green function is required since
the interaction between the solitons or nonlinear excitations is highly
nonlinear. Such considerations provide motivation for finding a new
mathematical approach for describing general nonlinear excitations and
relevant interactions in the bio-systems. Fortunately, based on our
previous work about nonlinear Green functions, the introduced “breath”
model can be improved to describe a process that the damaged bio-solitons
gradually return their health status by "breath" with surround field of
health solitons. The energy and entropy for the “breath” process are
found to be related to three conditions: (1) the interaction between the
both solitons is highly nonlinear; (2) the “breath” process has
macro-quantum character; (3) the interaction is like kind of “coherence”.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Bio-solitons, nonlinear quantum fields, nonlinear Green function,
bio-photon emission and Qigong.
Low-Cost Multilevel Modulation Formats for 100Gbps Transmission with
Direct Detection
by Majed Omar Al-Dwairi,
Ziad A. AlQadi
Vol. 3. n. 5, pp. 289-292
Abstract - This
paper investigates multilevel amplitude shift keying (M-ASK) and M-ASK
combined with differential phase shift keying (M-ASK-Bipolar) at a total
bit rate of 107 Gb/s. The aim is to find a cost-effective very high
speed transport solution. Numerical investigation was performed using
Monte Carlo simulations. The obtained results indicate that the proposed
modulation formats can be operated at 100Gb/s in optical communication
systems with low implementation effort and high spectral efficiency.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Optical communication, multilevel amplitude shift keying (M-ASK),
Differential phase shift keying (DPSK).
Plane Wave
Scattering from a Metachiral Slab
by Pierre Hillion
Vol. 3. n. 5, pp. 293-298
Abstract - Wave
propagation in a metachiral slab with negative permittivity and
permeability, endowed with the Post constitutive relations and
sandwiched between two isotropic media is first analyzed. Two modes can
propagate uncoupled in an infinite medium. The scattering of an harmonic
plane wave impinging on a face of this slab is investigated with a
careful discussion of reflected and refracted fields.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Metachiral Slab, Wave Scattering, Constitutive Relations.
Experiment Study of NO Reduction by DC Negative Corona Discharge in
N2+O2 +NO Mixture
by I. S. Medjahdi, M.
Lemerini, A. K. Ferouani
Vol. 3. n. 5, pp. 299-303
Abstract - This work
presents a study experiment of NO reduction by DC Negative corona
discharge in N2+O2+NO obtained in Laboratory d’hydrodynamique, Sevilla
Spain. The mixture is presented where voltage applied 5, 6 and 7 kV with
200 ppm of NO are injected. The ap¬plied voltage was maintained for 50
minutes, so as to enable that a stationary current and, presumably,
stationary species concentrations, were reached. Ultraviolet absorption
spectroscopy operating in the wavelength of 190 to 330 nm was used to
identify the species and quantify their concentration. The obtained
resultant was predicted by our model. Nitrous oxide has been destroyed
with the augmenta¬tion of corona current. We observed different times to
NO removal 50 minutes at 5 kV and 20 minutes at 7 kV. Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Kinetic chemical, Ultraviolet absorption, Negative corona
discharge, Removal NO.
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