|
| |
Home>Products>Journal and Reviews>I.RE.PHY.>Latest
issue
International Review
of PHYSICS - Papers
 A
Zero Point Energy Distribution of Finite Density
by Bo Lehnert
Vol. 3. n. 6, pp. 304-308
Abstract - In the
conventional theory on equilibrium radiation, the zero point energy part
leads to a frequency distribution having the unacceptable result of an
infinite total energy density. In this investigation a modified theory
is proposed which leads to a finite such density. As an example of the
present theory, the gravitational equilibrium of a spherically symmetric
gas cloud of zero point energy photons has been considered, in a model
of an expanding universe which includes dark energy and dark matter. The
model is used to estimate the magnitude of the zero point energy
density. It introduces a small modification of the Casimir effect, in
the form of a high frequency saturation. Additional experiments are
proposed with the aim of confirming such a saturation.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords: Vacuum
quantum fluctuations, zero point energy, Casimir effect.
Vol. 3. n. 6, pp. 309-313
Abstract
-
This paper addresses the problem of the electrostatic
perturbation in multi-dust-acoustic plasma species with Z- pinches using
various mixtures. It is demonstrated that the plasma shell separates
into two distinct annuli, which implode concentrically. This phenomenon
is quantitatively explained using a semi hydrodynamic model. In this
case, stability is investigated and an expression for the growth rate of
Rayleigh-Taylor type instability is presented. The growth rate is found
to be independent of the degree of dust plasma compressibility, and
somewhat reduced in the presence of an ion mixture.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
PACS numbers: 52.27.Lw, 52.35.Fp, 52.35.We, 52.27.Cm.
Vol. 3. n. 6, pp. 314-318
Abstract
-
The structural stability of BeX (X=S, Se, Te) under high pressure has been
investigated using a first-principles pseudopotential method within the
generalized gradient approximation. A phase transition sequence from
zincblende to NiAs then to rocksalt is found. For BeS the
zincblend-NiAs-rocksalt pressures are 62 and 278 GPa, 52 and 207 GPa for
BeSe and 36 and 49 GPa for BeTe. The structural parameters of three
compounds and phase transition pressures from zincblende to NiAs for
BeSe and BeTe agree quite well with the experimental results. However,
for BeS there is a discrepancy in theoretical and experimental
transition pressures.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
High pressure, Phase transition, First-principles, DFT.
Abstract
-
In this paper the distributions of the statistical
breakdown time delay ts in neon DC discharges with hard
galvanic layer of gold on the cathode are presented. The experimentally
obtained distributions, under unstable conditions, are fitted by
nonstationary exponential distribution with time dependent parameters,
which is derived based on the binomial distribution for the occurrence
of initiating electrons. The curving of the Laue diagrams is described
by a time varying electron yield Y (number of generated electrons in the
interelectrode gap per second) and explained by the cathode sputtering.
The increasing electron yield is used for describing enhanced cathode
emissivity (“roughening” effect of the cathode sputtering), while the
decreasing electron yield describes the reduced cathode emissivity
(“smoothing” effect of the cathode sputtering). The Laue diagrams, the
cumulative and density distributions of the statistical time delay at
the increasing and decreasing electron yield are also fitted by the
stationary exponential and Weibull distributions for comparison.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Breakdown time delay, Electrical discharges, Nonstationary
exponential distribution.
Abstract
-
We have studied hadronic events from e+e– annihilation data at different
centre-of-mass energies .The operation of the AMY collaboration offers a
unique opportunity to test QCD by considering different observables. The
main results concern the measurement of the strong coupling constant, αs
, from hadronic event shapes . The coupling constant, αs, is measured by
two different methods, first by employing the jet clustering algorithm
introduced by the JADE group. By using AMY data , the value of αs is
determined to be 0.123± 0.004. Next, from the thee jet distribution, we
extract the strong coupling constant, αs, at Leading(LO), Next to
Leading(NLO) and Next to Next Leading Order (NNLO) from AMY data. The
results are more consistent with the running of αs, expected from QCD
predictions at NNLO corrections. We will discuss all these features in
this paper.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Altarelli-Parisi , Three-jet rate, NNLO.
Vol. 3. n. 6, pp. 331-339
Abstract
-
In this paper, we proposed a new contribution on the theory of capillarity
in a particular case of the contact of a drop, in axisymmetric geometry,
on cylindrical fibers (surfaces in horizontal or vertical positions), by
using the classical method of the Lagrange multipliers and the variation
theory. In many practical cases, the geometry of the solid is typically
axisymmetric. A typical case of a axisymmetric solid, which was not
mathematically very studied in literature, is that of a liquid drop in
axisymmetric position in contact with a vertical position rigid
cylindrical surface, where the contact line is generally a circle with a
specific linear free energy. A new formulation of the Laplace and Young
equations in that case was given and an effect of the gravity force on
the calculation of the contact angle of a liquid drop on a fiber and the
surface tension of the solid was shown. On the other hand, we gave a
mathematical and numerical study of the capillary problem of the fiber,
in absence of gravity.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Mathematical Modeling, Fiber, Contact angle, Laplace and Young
equations surface energy.
On the
Transmitted Flux through a Filled Bent Ducts
by Z. Faik Ouahab, A.
Jehouani, J. Ghassoun, A. Oubaiddou
Vol. 3. n.
6, pp. 340-343
Abstract - All done
studies on the neutron transmission through duct concerned empty duct.
The aim of the present paper is the neutron transmission through filled.
For empty bent duct; the neutron transmission is due only to the neutron
reflection on duct wall. For filled duct, the major contribution is due
to the scattering on atoms the filled the duct. Neutron secondary
sources are considered at the mouth of each leg after each elbow .The
obtained flux at the exit of the duct are compared to ours calculated by
MCNP-5C code.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Duct, Monte Carlo, Neutron, Flux, Probability.
Behavior Geotechnical and Geologic of the Grounds Northeast Algerian
Affected by the Landslides
by A. Saihia
Vol. 3. n.
6, pp. 344-348
Abstract -
Landslides made their appearance with the current of the decade 1990 and
the beginning of years 2000 on much of places of the town of Constantine
and its area which extends to north to the Mediterranean. These slips
appeared after a rainy climate repeated over successive years. According
to the results of analyses on sites, lithology, the microtectonic one,
water, the slope of the relief, are the principal causes. The geology of
northern of Constantine is characterized by the presence of clay and
marl. The complexity of the clay soils, their capacity of saturation,
the deterioration of the rocks and their fast degradation by seepage
waters in these zones are as many factors favorable to the release and
the acceleration of the landslides. Geological research and meticulous
geotechnics were carried out on the sites accompanied by series by
measurements by inclinometer, and piezometers.
Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Landslide, North East Algeria, Géotechnic, Clay, Inclinometer.
Geometrical Estimation of Information Theoretical Impacts of Incoherent
Attacks for Quantum Cryptography
by L. Gyongyosi, S. Imre
Vol. 3. n. 6, pp.
349-362
Abstract - Quantum
cloning based attacks have deep relevance in quantum cryptography. In
quantum cryptography the encoded pure quantum states are sent through a
quantum communication channel. An attacker on the quantum channel cannot
clone the sent qubits perfectly, and the legal parties can detect the
disturbance generated by an eavesdropper. The best eavesdropping attacks
for quantum cryptography use quantum cloning machines. The eavesdropper
has to use an ancilla or probe quantum state, interact with the
originally sent quantum state. The proposed security analysis is based
on the Four-state (BB84) and Six-state quantum cryptography protocols.
An eavesdropper could use different types of cloning machines, the best
results for BB84 can be achieved by phase-covariant cloning machine, in
the Six-state protocol the lowest disturbance level can be reached by
using universal quantum cloner (UCM). In this paper, we show an
effective geometrical method to compute the fidelity of quantum cloning
based attacks for the Four-state and Six-state quantum cryptography
protocols, using fast quantum relative entropy based Delaunay
tessellation. Copyright © 2009 Praise Worthy Prize S.r.l. -
All rights reserved
Keywords:
Quantum cryptography, Quantum communication, Quantum informational
distance.
|
