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The Role of the Exclusion Principle for Atoms to
Stars: A Historical Account, by N. Straumann
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A Simple Solution of the Time-Independent
Schrödinger Equation in One Dimension and Some Applications,
by H. H. Erbil
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(Anti-lambda cero)
Polarization in Particle-Nucleus
Reactions, by J. Félix
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Analysis of the Quasi Periodic Scenario Leading to
Chaos in a Square Cavity, by S. Laouar, E. Mezaache, M. Daguenet
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Improved Approximation of the Free-space Fresnel
Diffraction by the Fractional Fourier Transform, by S.
Boucherit, L. Bouamama, M. Bouafia, G. Wernicke
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QED BRS Quantization in the Non commutative
Space-time Geometry, by N. Mebarki, M. Harrat, M. Boussahel, O.
Benabbés
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Innovative Concepts of Dual-Species Proton/Carbon
Medical Synchrotrons, by M. Pavlovič, V. Nečas, E. Griesmayer,
T. Schreiner
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Hydrogen and Carbon Effect on Cu-4%at.Be Alloy
Oxidised Surface, by S. Belkhiat, F. Keraghel
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Precipitation Kinetics of the Hardening Phase in Two
6061 Aluminium Alloys, by Y. Aouabdia, S. Hamamda, A. Boubertakh
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DBD Treatment of Textiles, by R. Morent, N. De
Geyter, C. Leys
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Rheology of Dilute Polymer Solutions with
Time-Dependent Screening of Hydrodynamic Interactions, by V.
Lisy, J. Tothova, B. Brutovsky
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A Neural Approach to Study the Transport
Coefficients in the Crystalline Silicon, by D. Arar, F. Djeffal,
T. Bendib
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Fibre-optic Interferometric Optical Filter for
Spectral Resolution of Closely Spaced Frequencies, by K. De
Souza
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International Review
of PHYSICS - Papers
 The
Role of the Exclusion Principle for Atoms to Stars: A Historical Account
by N. Straumann
Abstract - In a
first historical part I shall give a detailed description of how Pauli
discovered – before the advent of the new quantum mechanics – his
exclusion principle. The second part is devoted to the insight and
results that have been obtained in more recent times in our
understanding of the stability of matter in bulk, both for ordinary
matter (like stones) and self-gravitating bodies.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Exclusion Principle, Atoms, Stars.
A Simple Solution of the Time-Independent Schrödinger Equation in One
Dimension and Some Applications
by H. H. Erbil
Abstract - We found
a simple procedure for the solution of the time-independent Schrödinger
equation in one dimension without making any approximation. The wave
functions are always periodic. Two difficulties may be encountered: one
is to solve the equation E = U(x), where E and U(x) are the total and
potential energies, respectively, and the other is to calculate the
integral ∫√U(x)dx. If these calculations
cannot be made analytically, it should then be performed by numerical
methods. To find the energy and the wave function of the ground state,
there is no need to calculate this integral, it is sufficient to find
the classical turning points, that is to solve the equation E = U(x). A
particle in an infinitely high potential well of arbitrary form was
solved by employing a simple procedure without making any approximation.
Two different solutions were obtained, namely, symmetric and
antisymmetric. These solutions are always damped periodic functions.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
The Schrödinger Equation, Infinitely High Potential Well.
Abstract -
Average
(Anti-lambda cero)
polarization created in
particle-Nucleus collisions depends on the scaling Feynman parameter of
(Anti-lambda cero) (xF),
the transversal
(Anti-lambda cero)
momentum with respect to the incoming beam
particle (PT), and
(Anti-lambda
cero) (lambda cero)
invariant mass as follows: As function of xF
and PT, average (Anti-lambda
cero)
polarization from inclusive and exclusive
particle-Nucleus reactions is described very well by P(xF,
PT)=axFPT, within statistical errors,
in −1.0<xF<+1.0 and 0.0<PT<1.8 GeV. a is
independent of the beam-particle energy and dependent of both target and
beam nature as follows: In K+p reactions, a=+1.142±0.231 (GeV)-1,
χ2/dof=0.78; in
(Antiproton-proton)
reactions, a=−0.343±0.073 (GeV)-1, χ2/dof=0.69; in
pBe reactions, a=+0.030±0.016 (GeV)-1, χ2/dof=0.81;
in Σ−(C+Cu) reactions, a=+0.008±0.012 (GeV)-1, χ2/dof=0.37;
in
(Antiproton-proton)
reactions, a=−1.434±0.118 (GeV)-1,
χ2/dof=1.16. As function of xF and PT,
(Anti-lambda
cero)
polarization is akin to
(lambda cero)
polarization when the strange baryons are
produced in identical symmetric physical conditions. P(xF,
PT)=axFPT is the most simple bilinear
form that describes average (Anti-lambda
cero)
polarization from
inclusive and exclusive particle-Nucleus reactions in −1.0<xF<+1.0
and 0.0<PT<1.8 GeV.
As function of
(Anti-lambda cero) (lambda cero) invariant mass, from
(Antiproton-proton) ->
(Anti-lambda
cero) (lambda cero)
reactions, average
(Anti-lambda cero)
polarization is roughly a monotonic
decreasing function: At ~2.5 GeV, close to
(Anti-lambda cero) (lambda cero) mass threshold,
(Anti-lambda cero) polarization
is ~ +0.250±0.175, it decreases to zero -as
(Anti-lambda cero) (lambda cero) invariant mass increases-,
and goes to ~ −0.420±0.260 at ~3.626 GeV. This
(Anti-lambda cero) polarization
behavior is analogous to
(lambda
cero)
polarization from
Proton-proton reaction -> Fast proton (lambda cero) (Kaon plus)
at 800
GeV as function of
(lambda
cero) (Kaon plus) invariant
mass.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Antilambda; baryon; (Anti-lambda cero) (lambda cero)
invariant mass; (Anti-lambda cero) (lambda cero)
polarization.
Analysis
of the Quasi Periodic Scenario Leading to Chaos in a Square Cavity
by S. Laouar, E.
Mezaache, M. Daguenet
Abstract - Thermal
natural convection of air (Pr = 0,71) in a two dimensional square cavity
with two vertical walls nonuniformly heated and the two others held
adiabatic, is studied numerically. With increasing Rayleigh number
(considered here as a control parameter), the system transits to
oscillatory regime via a super critical Hopf bifurcation followed by an
under critical Hopf bifurcation at critical Rayleigh number of 4,26x106.
As Rayleigh number increases further a quasi-periodic regime with two
frequencies settles. While continuing to increase Rayleigh number, the
ratio between the two fundamental frequencies becomes rational. In this
case, phase-locking motion is the main regime before chaos. Chaotic
state is observed for Rayleigh number greater than 1,4x107.
The system is sensitive to initial conditions. All numerical results
have been characterized by looking to the Poincaré sections and phase
portraits. For the chaotic state, the largest Lyapunov exponent is
positive and the attractor dimension is fractional.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Chaos, Fractal Dimension, Lyapunov Exponent, Natural Convection,
Strange Attractor.
Improved Approximation of the Free-space Fresnel Diffraction by the
Fractional Fourier Transform
by S. Boucherit, L.
Bouamama, M. Bouafia, G. Wernicke
Abstract - The
Fresnel diffraction of an object illuminated by a plane wave, in the
free space propagation, is of great interest in several optical
applications, mainly, for numerical reconstruction of holograms in
digital holography. The Fractional Fourier transform (FrFT) seems to be
a convenient tool for the approximation of such diffraction. It was
pointed out in several works, that this approximation is valid only
under the appropriate values of the parameters of the FrFT and with
respect of certain restrictive conditions. However the result still
suffers from errors due to the scaling factors and the accuracy of the
approximation will be lost if we move away the central order.
In this paper we present an analytical approach based on FrFT permitting
to describe the Fresnel diffraction in the free space propagation with a
very good precision on the whole pattern of diffraction including, low
and high frequencies.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Fresnel diffraction, Fractional Fourier transforms.
QED
BRS Quantization in the Non commutative Space-time Geometry
by N.
Mebarki, M. Harrat, M. Boussahel, O. Benabbés
Abstract - Using
Seiberg-Witten maps approach to non commutative space-time QED ,
nilpotent generalized BRS and anti-BRS transformations as well as
Fadeev-Popov and modified gauge fixing terms are obtained. Moreover, and
up to the second order of the noncommutativity parameter, modified field
equations and conserved BRS current are derived. Furthermore, some
clarifications about the preservation of the space-time noncommutative
commutation relations are also presented.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
BRST Quantization, Gauge Theories, Non Commutative Geometry.
Innovative Concepts of Dual-Species Proton/Carbon Medical Synchrotrons
by M. Pavlovič, V. Nečas,
E. Griesmayer, T. Schreiner
Abstract -
Hospital-based facilities offering treatments with low-LET and high-LET
particles delivered by a common particle accelerator (LET = Linear
Energy Transfer) are one of the recent trends in ion therapy. Protons
and carbon ions are considered to be the best particle species for
low-LET and high-LET treatments, respectively. Innovative concepts of
proton/carbon medical synchrotrons based on the acceleration of
molecular hydrogen ions for generation of protons are presented in the
paper. These concepts do not compromise the medical requirements, but
they are expected to bring several major advantages concerning the
design, operation and cost of the accelerator: (1) shrinking the overall
magnetic beam rigidity span of extracted beams, (2) reducing the space
charge of a hydrogen beam at the injection, (3) a compact dual-species
injector layout and (4) making a charge-exchange extraction technique at
FFAG (Fixed Field Alternating Gradient) synchrotrons possible. Further
potential advantages concern the power supplies (especially the ripple),
field quality of the bending magnets and time structure of the extracted
spills.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
FFAG, Ion therapy, Medical accelerator, Synchrotron.
Hydrogen
and Carbon Effect on Cu-4%at.Be Alloy Oxidised Surface
by S. Belkhiat, F.
Keraghel
Abstract - Auger
electron spectroscopy (AES) has been used to study Be segregation on
Cu-4%at. Be alloy surface. In this work, the surface atomic composition
was followed as a function of temperature at the surface, in hydrogen
atmosphere. The activation energy of Be segregation has been
experimentally determined. The result is in agreement with the
theoretical value. It has been found that in hydrogen atmosphere, the
segregation energy of Be decreases and molecular adsorption occurs at
the oxidized Cu-Be alloy surface. Hydrogen and oxygen effects are
discussed in terms of formation heats of Be (OH)2, Cu (OH)2
, BeH, BeH2 and CuH chemical components in the alloy matrix.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Cu-4%at. Be, segregation energy, Cu (OH)2, BeH2,
BeH, Be (OH)2.
Precipitation
Kinetics of the Hardening Phase in Two 6061 Aluminium Alloys
by Y. Aouabdia, S.
Hamamda, A. Boubertakh
Abstract - The
purpose of this work is to study the kinetics of the precipitation of
the hardening phase in two commercial age-hardenable Al–Mg–Si alloys. A
review of the theoretical framework for solid-state reactions kinetics
and the determination of kinetic parameters from DSC curves is provided,
then used to quantify β" precipitation in the two alloys studied.
Despite failure to achieve high levels of accuracy, due, in particular,
to the dilution of the alloys, the procedure to analyse this
precipitation reaction yields valuable results. It is established that β" precipitates homogenously
as needles which grow through an enhanced-diffusion mechanism.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Activation energy, Aluminium alloys, β" phase, Precipitation,
Reactions kinetics.
DBD
Treatment of Textiles
by R. Morent, N. De Geyter, C. Leys
Abstract -
Dielectric barrier discharges (DBDs) are non-thermal plasmas which exist
in a broad pressure range. A characteristic feature is that at least one
electrode is covered by an insulating layer. They are able to
effectively generate atoms, radicals and other excited species by
energetic electrons. Therefore, they are widely used for industrial
applications. Typical applications are ozone generation, environmental
pollution control, excimer lamps, CO2-lasers, plasma displays
and surface modification. In this paper, the literature on the
application of DBDs for the treatment of textile materials is reviewed.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
dielectric barrier discharge, textile, surface modification.
Rheology
of Dilute Polymer Solutions with Time-Dependent Screening of
Hydrodynamic Interactions
by V. Lisy, J. Tothova, B. Brutovsky
Abstract - The
screening of hydrodynamic interactions (HI) essentially affects
macroscopic properties of polymeric solutions. This screening depends
not only on the polymer concentration, but has a dynamic nature. In the
present work, a bead-spring theory is developed, in which this
phenomenon is described for solutions of nonentangled polymer coils. The
equation of motion for the beads of a test polymer is solved together
with the Brinkman’s equation for the solvent velocity that takes into
account the presence of other coils in solution. The time correlation
functions for the polymer normal modes are found. A tendency to the
screening of HI is demonstrated on the coil diffusion as well as on the
relaxation of its internal modes. With the growing concentration of the
coils they both show a transition to the exact Rouse behavior. The
viscosity of the solution and some other observable quantities are
calculated. As the time increases, the time-dependent quantities change
their behavior from the Rouse regime through the Zimm one again to the
Rouse dynamics at long times.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Hydrodynamics, Polymer Solution, Rheology, Screening of
Hydrodynamic Interaction.
A
Neural Approach to Study the Transport Coefficients in the Crystalline
Silicon
by D. Arar, F. Djeffal, T. Bendib
Abstract - The study
of the transport coefficients in electronic devices is currently carried
out by analytical or numerical models. This study requires several
simplifying assumptions, generally necessary to lead to analytical
expressions in order to study the various electric characteristics of
the electronic device. However, the neural modeling which constitutes
the aim of our work does not use in theory any simplifying assumption.
In our case, we use the Artificial Neural Networks (ANNs) as a
computational tool to develop analytical approaches in order to study
the transport phenomenon of the charge carriers (electrons or holes) in
crystalline silicon as function of the temperature, doping concentration
and the applied electric field. The developed analytical approaches can
also be incorporated into the circuits simulators to study solid-state
devices without impact on the computational time and data storage.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Transport coefficients, Neural computation, High fields,
Temperature, Doping.
Fibre-optic
Interferometric Optical Filter for Spectral Resolution of Closely Spaced
Frequencies
by K. De Souza
Abstract -
Narrowband optical filters are used in many applications to separate two
signals of closely spaced frequencies. The filter’s performance is a
function of its throughput and rejection. For weak signals, the filter
should provide both high throughput of the wanted signal and high
rejection of the adjacent unwanted signal. A double-pass configured all-fibre
Mach-Zehnder interferometric optical filter fulfils these requirements.
The configuration is described and theoretically compared with a
single-pass all-fibre Mach-Zehnder interferometer and a bulk Fabry-Perot
interferometer operated in both transmission and reflection modes and
shown to have superior performance for certain applications. The
spectral responses and rejections of the single-pass and double-pass
Mach-Zehnder interferometers are determined experimentally and agree
with theory. Observation of polarization effects in the double-pass
Mach-Zehnder interferometer is also presented.
Copyright © 2007 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Brillouin scattering, fibre-optic sensor, filters, interferometry,
Rayleigh scattering.
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