title:
EHD ponderomotive forces and aerodynamic flow control using plasma
  actuators

abstract:
  We present a self-consistent two-dimensional fluid model of the temporal and
spatial development of the One Atmosphere Uniform Glow Discharge Plasma
(OAUGDP$^{\circledR}$). Continuity equations for electrically charged species
N$_2^+$, N$_4^+$, O$_2^+$, O$_2^-$ and electrons are solved coupled to the
Poisson equation, subject to appropriate boundary conditions. It was used an
algorithm proposed by Patankar$^{\cite{Patankar}}$. The transport parameters
and rate coefficients for electrons at atmospheric pressure are obtained by
solving the homogeneous Boltzmann equation for electrons under the hydrodynamic
assumption. Operational variables are obtained as a function of time: electric
current; surface charge accumulated on the dielectric surface; the memory
voltage and the gas voltage controlling the discharge. It is also obtained the
spatial distribution of the electric field, the populations of charges species,
the resulting ponderomotive forces, and the gas speed.


title: A Study of a Cold-Season Downburst Event over the Oklahoma Panhandle

abstract: This paper has been withdrawn by the author due to obsolete content.


title: First Passage Time Densities in Resonate-and-Fire Models

abstract:
  Motivated by the dynamics of resonant neurons we discuss the properties of
the first passage time (FPT) densities for nonmarkovian differentiable random
processes. We start from an exact expression for the FPT density in terms of an
infinite series of integrals over joint densities of level crossings, and
consider different approximations based on truncation or on approximate
summation of this series. Thus, the first few terms of the series give good
approximations for the FPT density on short times. For rapidly decaying
correlations the decoupling approximations perform well in the whole time
domain.
  As an example we consider resonate-and-fire neurons representing stochastic
underdamped or moderately damped harmonic oscillators driven by white Gaussian
or by Ornstein-Uhlenbeck noise. We show, that approximations reproduce all
qualitatively different structures of the FPT densities: from monomodal to
multimodal densities with decaying peaks. The approximations work for the
systems of whatever dimension and are especially effective for the processes
with narrow spectral density, exactly when markovian approximations fail.


title: The Measurement of AM noise of Oscillators

abstract:
  The close-in AM noise is often neglected, under the assumption that it is a
minor problem as compared to phase noise. With the progress of technology and
of experimental science, this assumption is no longer true. Yet, information in
the literature is scarce or absent. This report describes the measurement of
the AM noise of rf/microwave sources in terms of Salpha(f), i.e., the power
spectrum density of the fractional amplitude fluctuation alpha. The proposed
schemes make use of commercial power detectors based on Schottky and tunnel
diodes, in single-channel and correlation configuration. There follow the
analysis of the front-end amplifier at the detector output, the analysis of the
methods for the measurement of the power-detector noise, and a digression about
the calibration procedures. The measurement methods are extended to the
relative intensity noise (RIN) of optical beams, and to the AM noise of the
rf/microwave modulation in photonic systems. Some rf/microwave synthesizers and
oscillators have been measured, using correlation and moderate averaging. As an
example, the flicker noise of a low-noise quartz oscillator (Wenzel 501-04623E)
is Salpha = 1.15E-13/f, which is equivalent to an Allan deviation of
sigma_alpha = 4E-7. The measurement systems described exhibit the world-record
lowest background noise.


title:
Negative and Positive Lateral Shift of a Light Beam Reflected from a
  Grounded Slab

abstract:
  We consider the lateral shift of a light beam reflecting from a dielectric
slab backed by a metal. It is found that the lateral shift of the reflected
beam can be negative while the intensity of reflected beam is almost equal to
the incident one under a certain condition. The explanation for the negativity
of the lateral shift is given in terms of the interference of the reflected
waves from the two interfaces. It is also shown that the lateral shift can be
enhanced or suppressed under some other conditions. The numerical calculation
on the lateral shift for a realistic Gaussian-shaped beam confirms our
theoretical prediction.


title:
Direct excitation of the forbidden clock transition in neutral 174Yb
  atoms confined to an optical lattice

abstract:
  We report direct single-laser excitation of the strictly forbidden
(6s^2)^1S_0 -(6s6p)^3P_0 clock transition in the even 174Yb isotope confined to
a 1D optical lattice. A small (~1.2 mT) static magnetic field was used to
induce a nonzero electric dipole transition probability between the clock
states at 578.42 nm. Narrow resonance linewidths of 20 Hz (FHWM) with high
contrast were observed, demonstrating a record neutral-atom resonance quality
factor of 2.6x10^13. The previously unknown ac Stark shift-canceling (magic)
wavelength was determined to be 759.35+/-0.02 nm. This method for using the
metrologically superior even isotope can be easily implemented in current Yb
and Sr lattice clocks, and can create new clock possibilities in other alkaline
earth-like atoms such as Mg and Ca.


title: Large-N droplets in two dimensions

abstract:
  Using lattice effective field theory, we study the ground state binding
energy of N distinct particles in two dimensions with equal mass interacting
weakly via an attractive SU(N)-symmetric short range potential. We find that in
the limit of zero range and large N, the ratio of binding energies
B_{N}/B_{N-1} approaches the value 8.3(6).


title: Generalized model for human dynamics

abstract:
  Human dynamics model consistent with our natural ability to perform different
activities is put forward by first arguing limitations of the model suggested
by Barabasi (Nature, 435, 207-211, 2005).


title:
Minority game with local interactions due to the presence of herding
  behavior

abstract:
  In this paper, we introduce a framework to study local interactions due to
the presence of herding behavior in a minority game. The idea behind this
approach is to consider that some of the agents who play the game believe that
some of their neighbors are more informed than themselves. Thus, in this way,
these agents imitate their most informed neighbors. The notion of neighborhood
here is given by a regular network, a random network or a small world network.
We show that under herding behavior the cooperation between the agents is less
efficient than that one which arises in the standard minority game. On the
other hand, depending on the topology of the network, we show that that the
well known curve volatility versus memory, which caracterizes the minority
game, is a monotone decreasing curve.


title: Breit Interaction and Parity Non-conservation in Many-Electron Atoms

abstract:
  We present accurate {\em ab initio} non-perturbative calculations of the
Breit correction to the parity non-conserving (PNC) amplitudes of the $6s-7s$
and $6s-5d_{3/2}$ transitions in Cs, $7s-8s$ and $7s-6d_{3/2}$ transitions in
Fr, $6s-5d_{3/2}$ transition in Ba$^+$, $7s-6d_{3/2}$ transition in Ra$^+$, and
$6p_{1/2} - 6p_{3/2}$ transition in Tl. The results for the $6s-7s$ transition
in Cs and $7s-8s$ transition in Fr are in good agreement with other
calculations while calculations for other atoms/transitions are presented for
the first time. We demonstrate that higher-orders many-body corrections to the
Breit interaction are especially important for the $s-d$ PNC amplitudes. We
confirm good agreement of the PNC measurements for cesium and thallium with the
standard model .


title:
Geometrical and Physical Interpretations of Electronic Harmonic
  Oscillations in Four Space Dimensions

abstract:
  Following a previous proposition of quaternity spacetime for electronic
orbitals in neon shell, this paper describes the geometrical course each
electron takes as it oscillates harmonically within a certain quaternity space
dimension and provides the concrete connections between geometries and
trigonometric wavefunctions that observe Pythagorean theorem. By integrating
four quaternity space dimensions with conventional Cartesian coordinate systems
in calculus, we explain electronic motions by the Maxwell equation and general
Stokes theorem from the principles of rotation operation and space and time
symmetry. Altogether with the previous reports, we have effectively established
quaternity spacetime as a successful theory in elucidating the orbital shapes
and motions of electrons within inert atoms such as helium and neon. We point
out once again that 2px, 2py, and 2pz orbitals have different geometrical
shapes as well as orthogonal orientations, contrary to the traditional 2p
orbital model.


title: Large dimension forecasting models and random singular value spectra

abstract:
  We present a general method to detect and extract from a finite time sample
statistically meaningful correlations between input and output variables of
large dimensionality. Our central result is derived from the theory of free
random matrices, and gives an explicit expression for the interval where
singular values are expected in the absence of any true correlations between
the variables under study. Our result can be seen as the natural generalization
of the Marcenko-Pastur distribution for the case of rectangular correlation
matrices. We illustrate the interest of our method on a set of macroeconomic
time series.


title:
Statistical modelling of tropical cyclone tracks: modelling cyclone
  lysis

abstract:
  We describe results from the fifth stage of a project to build a statistical
model of tropical cyclone tracks. The previous stages considered genesis and
the shape of tracks. We now consider in more detail how to represent the lysis
(death) of tropical cyclones. Improving the lysis model turns out to bring a
significant improvement to the track model overall.


title:
Year-ahead prediction of US landfalling hurricane numbers: intense
  hurricanes

abstract:
  We continue with our program to derive simple practical methods that can be
used to predict the number of US landfalling hurricanes a year in advance. We
repeat an earlier study, but for a slightly different definition landfalling
hurricanes, and for intense hurricanes only. We find that the averaging lengths
needed for optimal predictions of numbers of intense hurricanes are longer than
those needed for optimal predictions of numbers of hurricanes of all strengths.


title:
State resolved rotational excitation cross sections and rates in H2+H2
  collisions

abstract:
  Rotational transitions in molecular hydrogen collisions are computed. The two
most recently developed potential energy surfaces for the H2-H2 system are used
from the following works: 1) A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J.
Peterson, J. Chem. Phys., 116 (2002) 666, and 2) P. Diep, J.K. Johnson, J.
Chem. Phys., 113 (2000) 3480; ibid. 112, 4465. Cross sections for rotational
transitions 00->20, 22, 40, 42, 44 and corresponding rate coefficients are
calculated using a quantum-mechanical approach. Results are compared for a wide
range of kinetic temperatures 300 K < T < 3000 K.


title: Performance of the Micromegas detector in the CAST experiment

abstract:
  The gaseous Micromegas detector designed for the CERN Axion search experiment
CAST, operated smoothly during Phase-I, which included the 2003 and 2004
running periods. It exhibited linear response in the energy range of interest
(1-10keV), good spatial sensitivity and energy resolution (15-19% FWHM at
5.9keV)as well as remarkable stability. The detector's upgrade for the 2004
run, supported by the development of advanced offline analysis tools, improved
the background rejection capability, leading to an average rate 5x10^-5
counts/sec/cm^2/keV with 94% cut efficiency. Also, the origin of the detected
background was studied with a Monte Carlo simulation, using the GEANT4 package.


title:
Sink flow deforms the interface between a viscous liquid and air into a
  tip singularity

abstract:
  In our experiment, an interface between a viscous liquid and air is deformed
by a sink flow of constant flow rate to form a sharp tip. Using a microscope,
the interface shape is recorded down to a tip size of 1 $\rm{\mu m}$. The
curvature at the tip is controlled by the distance $h$ between the tip and the
sink. As a critical distance $h^{\star}$ is approached, the curvature diverges
like $1/(h-h^{\star})^3$ and the tip becomes cone-shaped. As the distance to
the sink is decreased further, the opening angle of the cone vanishes like
$h^2$. No evidence for air entrainment was found, except when the tip was
inside the orifice.


title: Active Optical Clock

abstract:
  This letter presents the principles and techniques of active optical clock, a
special laser combining the laser physics of one-atom laser, bad-cavity gas
laser, super-cavity stabilized laser and optical atomic clock. As an example, a
compact version of active optical clock based on thermal Strontium atomic beam
shows a quantum-limited linewidth of 0.51 Hz, which is insensitive to laser
cavity-length noise, and may surpass the recorded narrowest 6.7 Hz of Hg ion
optical clock and 27Hz of very recent optical lattice clock. The estimated
0.1Hz one-second instability and 0.27Hz uncertainty are limited only by the
relativistic Doppler effect may be improved to 10mHz by using cold atoms.


title: The CMS Silicon Strip Tracker

abstract:
  With over 200 square meters of sensitive Silicon and almost 10 million
readout channels, the Silicon Strip Tracker of the CMS experiment at the LHC
will be the largest Silicon strip detector ever built. The design, construction
and expected performance of the CMS Tracker is reviewed in the following.


title: Interdisciplinary Monte Carlo Simulations

abstract:
  Biological, linguistic, sociological and economical applications of
statistical physics are reviewed here. They have been made on a variety of
computers over a dozen years, not only at the NIC computers. A longer
description can be found in our new book, an emphasis on teaching in
Eur.J.Phys. 26, S 79 and AIP Conf. Proc. 779, 49, 56, 69 and 75.


title:
Spatial solitons and modulational instability in the presence of large
  birefringence: the case of highly non-local liquid crystal

abstract:
  With reference to spatially non-local nematic liquid crystals, we develop a
theory of optical spatial solitons and modulational instability in anisotropic
media with arbitrarily large birefringence. Asymmetric spatial profiles and
multivalued features are predicted for self-localized light versus walk-off
angle. The results hold valid for generic self-focusing birefringent media and
apply to large angle steering of individual and multiple self-trapped optical
beams.


title: Finding way to bridge the gap between quantum and classical mechanics

abstract:
  We have calculated the momentum distributions of nanoparticles in diffraction
and interference dependent on the effective screening mass parameter or size
parameter and presented the calculations for a nanoparticle inside an infinite
square potential well and for a tunnelling nanoparticle through a square
potential barrier. These results display the transition from quantum to
classical mechanics and the simultaneous wave-particle duality of
nanoparticles. The concept that the effective screening effect increases with
increasing size of an object paves way for development of nanomechanics and
nanotechnology.


title: On the origin of Special Relativity

abstract:
  Retrospectively, in 1905, Special Relativity seemed palpably close; it was
"in the air". But apparently it needed the fresh approach of an unprejudiced
newcomer, Einstein, to take the final step. I report, in a pedagogical fashion,
on the scientific background that triggered the formulation of Special
Relativity and also on the role of Lorentz and Poincare.


title: Probability Densities in Strong Turbulence

abstract:
  According to modern developments in turbulence theory, the "dissipation"
scales (u.v. cut-offs) $\eta$ form a random field related to velocity
increments $\delta_{\eta}u$. In this work we, using Mellin's transform combined
with the Gaussain large -scale boundary condition, calculate probability
densities (PDFs) of velocity increments $P(\delta_{r}u,r)$ and the PDF of the
dissipation scales $Q(\eta, Re)$, where $Re$ is the large-scale Reynolds
number. The resulting expressions strongly deviate from the Log-normal PDF
$P_{L}(\delta_{r}u,r)$ often quoted in the literature. It is shown that the
probability density of the small-scale velocity fluctuations includes
information about the large (integral) scale dynamics which is responsible for
deviation of $P(\delta_{r}u,r)$ from $P_{L}(\delta_{r}u,r)$. A framework for
evaluation of the PDFs of various turbulence characteristics involving spatial
derivatives is developed. The exact relation, free of spurious Logarithms
recently discussed in Frisch et al (J. Fluid Mech. {\bf 542}, 97 (2005)), for
the multifractal probability density of velocity increments, not based on the
steepest descent evaluation of the integrals is obtained and the calculated
function $D(h)$ is close to experimental data. A novel derivation (Polyakov,
2005), of a well-known result of the multi-fractal theory [Frisch, "Turbulence.
{\it Legacy of A.N.Kolmogorov}", Cambridge University Press, 1995)), based on
the concepts described in this paper, is also presented.


title:
Meteor generated plasma columns in E-region ionosphere: fields and
  diffusion

abstract:
  A meteoroid penetrating the Earth's atmosphere leaves behind a trail of dense
plasma in the E-region ionosphere, a region where electrons are strongly
magnetized while ions are demagnetized due to their frequent collisions with
neutrals. While radar measurements of meteor trail evolution have been
collected and used to infer meteor and atmospheric properties since the 1950s,
no accurate quantitative model of trail fields and diffusion exists. This paper
describes a theory and simulations of trail plasma physics which applies to the
majority of small meteors. Unlike earlier papers, our theory assumes a
significant angle between the geomagnetic field and the plasma trail and
includes the important interaction between the trail and the background
ionospheric plasma. This study provides quantitative knowledge of the spatial
distribution and dynamics of the plasma density and electric field. This should
enable meteor and atmospheric researchers to more accurately interpret radar
observations of specular and non-specular meteor echoes.


title:
Historical Background as an Essential Ingredient for the Understanding
  of New Developments in Quantum Mechanics

abstract: Paper is taken out with immediate effect.


title:
Modeling self-organization of communication and topology in social
  networks

abstract:
  This paper introduces a model of self-organization between communication and
topology in social networks, with a feedback between different communication
habits and the topology. To study this feedback, we let agents communicate to
build a perception of a network and use this information to create strategic
links. We observe a narrow distribution of links when the communication is low
and a system with a broad distribution of links when the communication is high.
We also analyze the outcome of chatting, cheating, and lying, as strategies to
get better access to information in the network. Chatting, although only
adopted by a few agents, gives a global gain in the system. Contrary, a global
loss is inevitable in a system with too many liars


title:
Computing communities in large networks using random walks (long
  version)

abstract:
  Dense subgraphs of sparse graphs (communities), which appear in most
real-world complex networks, play an important role in many contexts. Computing
them however is generally expensive. We propose here a measure of similarities
between vertices based on random walks which has several important advantages:
it captures well the community structure in a network, it can be computed
efficiently, and it can be used in an agglomerative algorithm to compute
efficiently the community structure of a network. We propose such an algorithm,
called Walktrap, which runs in time O(mn^2) and space O(n^2) in the worst case,
and in time O(n^2log n) and space O(n^2) in most real-world cases (n and m are
respectively the number of vertices and edges in the input graph). Extensive
comparison tests show that our algorithm surpasses previously proposed ones
concerning the quality of the obtained community structures and that it stands
among the best ones concerning the running time.


title:
Dynamic Manipulation of Bose-Einstein Condensates With a Spatial Light
  Modulator

abstract:
  We manipulate a Bose-Einstein condensate using the optical trap created by
the diffraction of a laser beam on a fast ferro-electric liquid crystal spatial
light modulator. The modulator acts as a phase grating which can generate
arbitrary diffraction patterns and be rapidly reconfigured at rates up to 1 kHz
to create smooth, time-varying optical potentials. The flexibility of the
device is demonstrated with our experimental results for splitting a
Bose-Einstein condensate and independently transporting the separate parts of
the atomic cloud.


title: Nature and Quantization of the Proton Mass: An Electromagnetic Model

abstract:
  A method for quantization of the proton mass is here addressed, which
provides a plausible explanation for the origin of mass and leads to the
unification of mass and electric charge through their coupling. By means of an
electromagnetic approach, the calculated mass of the proton closely
approximates its experimental value and does so with dependence on a single
parameter. That is to say, the proposed fundamental system provides a way to
comprehend the source of mass as a property of the structure of elementary
particles. It brings a new tool to the task of gaining insight into the proton
mass and to unravelling the enigma of proton stability. The inner energy of
elementary particles, or equivalently their mass, is surmised here to have
electrodynamic roots, deriving from the dynamics of a single or pair of
electric charge(s) shaping out their structure. Mass appears as the quantized
balance of two inner energies which conform collapsing action and retentive
reaction. Charge and mass are not taken as independent entities as in the
traditional mode, instead mass appears as a by-product of the charge structural
dynamics, as does the magnetic moment. The proposed model clearly requires a
degree of willingness to consider possibilities not accounted for within the
framework of the Standard Model. So, this proposal is addressed to those who
are open to inspect a different look at the structure of elementary particles
and disposed to compare the two approaches, standing out of doctrinal
captivity.


title:
3-Space In-Flow Theory of Gravity: Boreholes, Blackholes and the Fine
  Structure Constant

abstract:
  A theory of 3-space explains the phenomenon of gravity as arising from the
time-dependence and inhomogeneity of the differential flow of this 3-space. The
emergent theory of gravity has two gravitational constants: G - Newton's
constant, and a dimensionless constant - alpha. Various experiments and
astronomical observations have shown that alpha is the fine structure constant
1/137. Here we analyse the Greenland Ice Shelf and Nevada Test Site borehole g
anomalies, and confirm with increased precision this value of alpha. This and
other successful tests of this theory of gravity, including the supermassive
black holes in globular clusters and galaxies, and the `dark-matter' effect in
spiral galaxies, demonstrates the validity of this theory of gravity. This
success implies that Newtonian gravity was fundamentally flawed from the
beginning.


title:
Inertial System and Special Relativity Finite Geometrical Field Theory
  of Matter Motion Part One

abstract:
  Special relativity theory is well established and confirmed by experiments.
This research establishes an operational measurement way to express the great
theory in a geometrical form. This may be valuable for understanding the
underlying concepts of relativity theory. In four-dimensional spacetime
continuum, the displacement field of matter motion is measurable quantities.
Based on these measurements, a finite geometrical field can be established. On
this sense, the matter motion in physics is viewed as the deformation of
spacetime continuum. Suppose the spacetime continuum is isotropic, based on the
least action principle, the general motion equations can be established. In
this part, Newton motion and special relativity are discussed. Based on the
finite geometrical field theory of matter motion, the Newton motion equation
and the special relativity can be derived simply based on the isotropy of
spacetime continuum and the definition of inertial system. This research shows
that the Lorentz transformation is required by both of the inertial system
definition and the time gauge invariance for inertial systems. Hence, the
special relativity is the logic conclusion of time invariance in inertial
system. The source independent of light velocity supports the isotropy of
inertial system rather than the concept of proper time, which not only causes
many paradox, such as the twin-paradox, but also causes many misunderstanding
and controversial arguments. The singularity of Lorentz transformation is
removed in other parts of finite geometrical field theory, where the gravity
field, electromagnetic field, and quantum field will be discussed with the time
displacement field.


title: Dynamic Stark effect and forbidden-transition spectral lineshapes

abstract:
  We report on an experimental and theoretical study of the dynamic (ac) Stark
effect on a forbidden transition. A general framework for parameterizing and
describing off-resonant ac-Stark shifts is presented. A model is developed to
calculate spectral line shapes resulting from resonant excitation of atoms in
an intense standing light-wave in the presence of off-resonant ac-Stark shifts.
The model is used in the analysis and interpretation of a measurement of the
ac-Stark shifts of the static-electric-field-induced \mbox{${\rm 6s^2}~ ^1{\rm
S}_0~\to ~{\rm 5d6s}~ ^3{\rm D}_1\:$} transition at 408 nm in atomic Yb. The
results are in agreement with estimates of the ac-Stark shift of the transition
under the assumption that the shift is dominated by that of the ${\rm 6s^2 \:}
^1{\rm S}_0\:$ ground state. A detailed description of the experiment and
analysis is presented. A bi-product of this work is an independent
determination (from the saturation behavior of the 408-nm transition) of the
Stark transition polarizability, which is found to be in agreement with our
earlier measurement. This work is part of the ongoing effort aimed at a
precision measurement of atomic parity-violation effects in Yb.


title: Endlessly single-mode holey fibers: the influence of core design

abstract:
  In this paper we evaluate the cut-off properties of holey fibers (HFs) with a
triangular lattice of air holes and the core formed by the removal of a single
(HF1) or more air holes (HF3 and HF7). With the aid of finite-element
simulations we determine the single-mode and multi-mode phases and also find
the air hole diameters limiting the endlessly single-mode regime. From
calculations of V and W parameters we find that in general HF1 is less
susceptible to longitudinal non-uniformities compared to the other designs for
equivalent effective areas. As an example we illustrate this general property
for the particular case of a macro-bending induced loss.


title:
Year ahead prediction of US landfalling hurricane numbers: the optimal
  combination of long and short baselines

abstract:
  Annual levels of US landfalling hurricane activity averaged over the last 11
years (1995-2005) are higher than those averaged over the previous 95 years
(1900-1994). How, then, should we best predict hurricane activity rates for
next year? Based on the assumption that the higher rates will continue we use
an optimal combination of averages over the long and short time-periods to
produce a prediction that minimises MSE.


title:
Contributions of Albert Einstein to Earth Sciences: A review in
  Commemoration of the World Year of Physics

abstract:
  The World Year of Physics (2005) is an international celebration to
commemorate the one hundredth anniversary of Einstein's "Annus Mirabilis". The
United Nations has officially declared 2005 the International Year of Physics.
However, the impact of Einstein's ideas was not restricted to physics. Among
numerous other disciplines, Einstein also made significant and specific
contributions to Earth Sciences. His geosciences-related letters, comments, and
scientific articles, are dispersed, not easily accesible and are poorly known.
The present review attempts to integrate them, as a tribute to Einstein in
commemoration of this centenary. These contributions can be classified into
three basic areas: geodynamics, geological (planetary) catastrophism and
fluvial geomorphology.


title: Application of the SALI chaos detection method to accelerator mappings

abstract:
  We apply the Smaller ALignment Index (SALI) method to a 4--dimensional
mapping of accelerator dynamics in order to distinguish rapidly, reliably and
accurately between ordered and chaotic motion. The main advantage of this index
is that it tends {\it exponentially} to zero in the case of chaotic orbits,
while it fluctuates around non--zero values in the case of quasiperiodic
trajectories. Thus, it avoids the notorious ambiguities concerning the eventual
convergence of (maximum) Lyapunov exponents to (positive) non-zero values.
Exploiting the different behavior of SALI in these two cases we produce phase
space `charts' where regions of chaos and order are clearly identified.
Evaluating the percentage of chaotic and escaping orbits as a function of the
distance from the origin we are able to estimate rapidly and accurately the
boundaries of the {\it dynamical aperture} of a proton beam, passing repeatedly
through an array of magnetic focusing elements.


title:
Experimental preparation of pure superposition states of atoms via
  elliptically polarized bichromatic radiation

abstract:
  We propose a simple and effective way of creating pure dark superposition
states. The generation of pure states is carried out by using bichromatic
radiation with controllable polarization ellipticity. We derived analytic
formulas for polarization elipticity to obtain pure dark states of different
Zeeman sublevels of alkali atoms. Experimentally we accumulated ~60% of the
atoms in the 0-0 dark state of the D1 line of Rb87


title:
Numerical Implementation of Generalized Robin-type Wall Functions and
  Their Application to Impinging Flows

abstract:
  The paper is devoted to the generalized wall functions of Robin-type and
their application to near-wall turbulent flows. The wall functions are based on
the transfer of a boundary condition from a wall to some intermediate boundary
near the wall. The boundary conditions on the intermediate boundary are of
Robin-type and represented in a differential form. The wall functions are
formulated in an analytical easy-to-implement form, can take into account the
source terms of the momentum equation, and do not include free parameters. The
log-profile assumption is not used in this approach. A robust numerical
algorithm is proposed for implementation of Robin-type wall functions to both
finite-difference and finite-volume numerical schemes. The algorithm of
implementation of the Robin-type wall functions to existing finite-volume codes
is provided. The axisymmetric impinging jet problem is numerically investigated
for different regimes on the base of the wall-functions implemented to the
high-Reynolds-number k-epsilon model.


title:
Komatiites: From Earth's Geological Settings to Planetary and
  Astrobiological Contexts

abstract:
  Komatiites are fascinating volcanic rocks. They are among the most ancient
lavas of the Earth following the 3.8 Ga pillow basalts at Isua and they
represent some of the oldest ultramafic magmatic rocks preserved in the Earth's
crust at 3.5 Ga. This fact, linked to their particular features (high magnesium
content, high melting temperatures, low dynamic viscosities, etc.), has
attracted the community of geoscientists since their discovery in the early
sixties, who have tried to determine their origin and understand their meaning
in the context of the terrestrial mantle evolution. In addition, it has been
proposed that komatiites are not restricted to our planet, but they could be
found in other extraterrestrial setting in our Solar System (particularly in
Mars and Io). It is important to note that komatiites may be extremely
significant in the study of the origins and evolution of Life on Earth. They
not only preserve essential geochemical clues of the interaction between the
pristine Earth rocks and atmosphere, but also may have been potential suitable
sites for biological processes to develop. Thus, besides reviewing the main
geodynamic, petrological and geochemical characteristics of komatiites, this
paper also aims to widen their investigation beyond the classical geological
prospect, calling attention to them as attracting rocks for research in
planetology and astrobiology.


title: Water vapor at a translational temperature of one kelvin

abstract:
  We report the creation of a confined slow beam of heavy-water (D2O) molecules
with a translational temperature around 1 kelvin. This is achieved by filtering
slow D2O from a thermal ensemble with inhomogeneous static electric fields
exploiting the quadratic Stark shift of D2O. All previous demonstrations of
electric field manipulation of cold dipolar molecules rely on a predominantly
linear Stark shift. Further, on the basis of elementary molecular properties
and our filtering technique we argue that our D2O beam contains molecules in
only a few ro-vibrational states.


title:
The mean electromotive force due to turbulence of a conducting fluid in
  the presence of mean flow

abstract:
  The mean electromotive force caused by turbulence of an electrically
conducting fluid, which plays a central part in mean--field electrodynamics, is
calculated for a rotating fluid. Going beyond most of the investigations on
this topic, an additional mean motion in the rotating frame is taken into
account. One motivation for our investigation originates from a planned
laboratory experiment with a Ponomarenko-like dynamo. In view of this
application the second--order correlation approximation is used. The
investigation is of high interest in astrophysical context, too. Some
contributions to the mean electromotive are revealed which have not been
considered so far, in particular contributions to the $\alpha$--effect and
related effects due to the gradient of the mean velocity. Their relevance for
dynamo processes is discussed. In a forthcoming paper the results reported here
will be specified to the situation in the laboratory and partially compared
with experimental findings.


title: On the origin of the deflection of light

abstract:
  Action at distance in Newtonian physics is replaced by finite propagation
speeds in classical post--Newtonian physics. As a result, the differential
equations of motion in Newtonian physics are replaced by functional
differential equations, where the delay associated with the finite propagation
speed is taken into account. Newtonian equations of motion, with
post--Newtonian corrections, are often used to approximate the functional
differential equations. In ``On the origin of quantum mechanics'', preprint,
physics/0505181, May 2005, a simple atomic model based on a functional
differential equation which reproduces the quantized Bohr atomic model was
presented. The unique assumption was that the electrodynamic interaction has a
finite propagation speed. In ``On the origin of the gravitational quantization:
The Titius--Bode Law'', preprint, physics/0507072, Jul 2005, a simple
gravitational model based on a functional differential equation which gives a
gravitational quantification and an explanation of the modified Titius--Bode
law is described. In ``On the origin of the anomalous precession of Mercury's
perihelion'', preprint, physics/0510086, Oct 2005, an explanation of the
anomalous precession of Mercury's perihelion is given in terms of a simple
retarded potential, which, at first order, coincides with Gerber's potential of
1898, and which agrees with the author's previous works. In this paper, it is
shown how the simple retarded potential presented in physics/0510086 also gives
the correct value of the gravitational deflection of fast particles of General
Relativity.


title: An inverted pendulum with a springy control as a model of human standing

abstract:
  The normal and the inverted pendulum continue to be one of the main physical
models and metaphors in science. The inverted pendulum is also a classic study
case in control theory. In this paper we consider a special demonstration
version of the inverted pendulum which is controlled via a spring. If the
spring constant is below a critical level the springy control will be unstable
and the pendulum will be kept from falling only by exercising a dynamically
varying control. This situation resembles the case of human bipedal quiet
standing with the Achilles tendon serving as the spring. The paper is written
with physics students in mind.


title: Towards more realistic dynamical models for DNA secondary structure

abstract:
  We propose a dynamical model for the secondary structure of DNA, which is
based on the finite stacking enthalpies used in thermodynamics calculations. In
this model, the two strands can separate and the bases are allowed to rotate
perpendicular to the sequence axis. We show, through molecular dynamics
simulations, that the model has the correct behaviour at the denaturation
transition.


title: Re-examination of the size distribution of firms

abstract:
  In this paper we address the question of the size distribution of firms. To
this aim, we use the Bloomberg database comprising multinational firms within
the years 1995-2003, and analyze the data of the sales and the total assets of
the separate financial statement of the Japanese and the US companies, and make
a comparison of the size distributions between the Japanese companies and the
US companies. We find that (i) the size distribution of the US firms is
approximately log-normal, in agreement with Gibrat's observation (Gibrat 1931),
and in contrast (ii) the size distribution of the Japanese firms is clearly not
log-normal, and the upper tail of the size distribution follows the Pareto law.
It agree with the predictions of the Simon model (Simon 1955). Key words: the
size distribution of firms, the Gibrat's law, and the Pareto law


title:
Lava channel formation during the 2001 eruption on Mount Etna: evidence
  for mechanical erosion

abstract:
  We report the direct observation of a peculiar lava channel that was formed
near the base of a parasitic cone during the 2001 eruption on Mount Etna.
Erosive processes by flowing lava are commonly attributed to thermal erosion.
However, field evidence strongly suggests that models of thermal erosion cannot
explain the formation of this channel. Here, we put forward the idea that the
essential erosion mechanism was abrasive wear. By applying a simple model from
tribology we demonstrate that the available data agree favorably with our
hypothesis. Consequently, we propose that erosional processes resembling the
wear phenomena in glacial erosion are possible in a volcanic environment.


title: Sagnac Interferometry in a Slow-Light Medium

abstract:
  We use a Sagnac interferometer to measure the dispersive and absorptive
properties of room temperature Rubidium vapor on the D_2 line at 780.2 nm. We
apply a pump beam such that the resulting Lambda system exhibits
Electromagnetically Induced Transparency. Using a "biased alignment" technique
we demonstrate a direct and robust method of measuring the rapid variation in
the refractive index. Such a "slow-light" Sagnac interferometer is ideally
suited to precision measurement applications such as magnetometry and inertial
sensing.


title:
Stock mechanics: a general theory and method of energy conservation with
  applications on DJIA

abstract:
  A new method, based on the original theory of conservation of sum of kinetic
and potential energy defined for prices is proposed and applied on Dow Jones
Industrials Average (DJIA). The general trends averaged over months or years
gave a roughly conserved total energy, with three different potential energies,
i.e. positive definite quadratic, negative definite quadratic and linear
potential energy for exponential rises (and falls), sinusoidal oscillations and
parabolic trajectories, respectively. Corresponding expressions for force
(impact) are also given. Keywords:


title:
Simulation Study of a Positive Ionospheric Storm Phase Observed at
  Millstone Hill

abstract:
  Simulation results from the NRL ionospheric model SAMI2 indicate that the
changes in the F-region over Millstone Hill during the geomagnetic storm
beginning on 3 April 2004 are primarily due to the influence of a long-lasting
eastward electric field, as was previously suggested by {\it Huang et al.}
[2005]. A simulation of the storm day agrees well with the observational data
and shows that, compared with the ionosphere of the previous quiet day, the
peak electron density in the F-region (NmF2) increased by a factor of $\approx
2$, the altitude of the peak density (hmF2) rose by $\approx 80$ km, and the
F-region electron temperature decreased by $\approx 1000$ K. Further
simulations in which either the neutral atmosphere and winds or the electric
field were replaced by their quiet day counterparts clearly suggest that the
electric field played the dominant, although not exclusive, role in producing
these effects.


title: Volume and surface constraints in the Cellular Potts Model

abstract: This paper has been withdrawn.


title: Theory of solvation in polar nematics

abstract:
  We develop a linear response theory of solvation of ionic and dipolar solutes
in anisotropic, axially symmetric polar solvents. The theory is applied to
solvation in polar nematic liquid crystals. The formal theory constructs the
solvation response function from projections of the solvent dipolar
susceptibility on rotational invariants. These projections are obtained from
Monte Carlo simulations of a fluid of dipolar spherocylinders which can exist
both in the isotropic and nematic phase. Based on the properties of the solvent
susceptibility from simulations and the formal solution, we have obtained a
formula for the solvation free energy which incorporates experimentally
available properties of nematics and the length of correlation between the
dipoles in the liquid crystal. Illustrative calculations are presented for the
Stokes shift and Stokes shift correlation function of coumarin-153 in
4-n-pentyl-4'-cyanobiphenyl (5CB) and 4,4-n-heptyl-cyanopiphenyl (7CB) solvents
as a function of temperature in both the nematic and isotropic phase.


title: On the study of neutrino properties

abstract:
  We review the discovery of the neutrino and outline the history of neutrino
physics. Many interesting phenomena involving the neutrino are exhibited. We
also discuss the long-standing solar neutrino puzzle and the properties of the
neutrino which lead to various important results. We present a possible
experimental test of the neutrino property. In addition, neutrino oscillation
and neutrino spin precession are also demonstrated.


title: Spectrometer Calibration by Expectation Maximization Method

abstract:
  Expectation Maximization (EM) algorithm is a parameter estimation method from
incomplete observations. In this paper, an implementation of this method to the
calibration of HKS spectrometer at Jefferson Lab is described. We show that the
application of EM method is able to calibrate the spectrometer properly in the
presence of high background noise, while the traditional nonlinear Least Square
method fail. The preliminary results of HKS spectrometer calibration is
presented.


title:
Domains of States of Chemical Systems: Le Chatelier Response, Structure
  of the Domains and Evolution

abstract:
  The paper investigates influence of the Le Chatelier response on the chemical
system behavior under stress, the shape of its domains of states in terms of
static and dynamic bifurcation diagrams, and the system proneness to evolution.
The usage of maps in thermodynamics of chemical systems is discussed.
Thermodynamics of chemical triggers, designed in similarity with laser, is
described. Results of this work are important in context of new model of
chemical equilibrium.


title:
Gravity Field and Electromagnetic Field-Finite Geometrical Field Theory
  of Matter Motion Part Two

abstract:
  Gravity field theory and electromagnetic field theory are well established
and confirmed by experiments. The Schwarzschild metric and Kerr Metric of
Einstein field equation shows that the spatial differential of time gauge is
the gravity field. For pure time displacement field, when its spatial
differentials are commutative, conservative fields can be established. When its
spatial differentials are non-commutative, Maxwell electromagnetic field
equations can be established. When the contra-covariant is required for the
non-commutative field, both Lorentz gauge and Coulomb gauge are derived in this
research. The paper shows that the light is a special matter in that the
addition of its Newtonian mass and its Coulomb electric charge is zero. In
fact, this conclusion is true for the electromagnetic wave in vacuum. For the
conservative field, the research shows that once the mass density and the
Coulom charge dendity are given, the macro spacetime feature is completely
determined. Both of them are intrisinc features of macro matter in cosimic
background. However, for the cosmic ages old events, the spatial curvature may
be cannot be ignored. On this sense, the oldest gravity field has the largest
curvature of space. This point is very intrinsic for astronomy matters.


title: Statistical modelling of tropical cyclone tracks: non-normal innovations

abstract:
  We present results from the sixth stage of a project to build a statistical
hurricane model. Previous papers have described our modelling of the tracks,
genesis, and lysis of hurricanes. In our track model we have so far employed a
normal distribution for the residuals when computing innovations, even though
we have demonstrated that their distribution is not normal. Here, we test to
see if the track model can be improved by including more realistic non-normal
innovations. The results are mixed. Some features of the model improve, but
others slightly worsen.


title:
Scintillation efficiency of liquid xenon for nuclear recoils with the
  energy down to 5 keV

abstract:
  The scintillation efficiency of liquid xenon for nuclear recoils has been
measured to be nearly constant in the recoil energy range from 140 keV down to
5 keV. The average ratio of the efficiency for recoils to that for gamma-rays
is found to be 0.19+-0.02.


title: Reflectionless Tunnelling of Light in Gradient Optics

abstract:
  We analyse the optical (or microwave) tunnelling properties of
electromagnetic waves passing through thin films presenting a specific index
profile providing a cut-off frequency, when they are used below this frequency.
We show that contrary to the usual case of a square index profile, where
tunnelling is accompanied with a strong attenuation of the wave due to
reflection, such films present the possibility of a reflectionless tunnelling,
where the incoming intensity is totally transmitted.


title:
Wave propagation in highly inhomogeneous thin films : exactly solvable
  models

abstract:
  We present an exact treatment of wave propagation in some inhomogeneous thin
films with highly space-dependent dielectric constant. It is based on a space
transformation which replaces the physical space by the optical path. In the
new space, the dispersion equation is that of a normal progressive wave. We
will show that the dispersion properties of such films are plasma- or
waveguide-like, the characteristic frequency being determined by the spatial
characteristics of the dielectric constant's variations only. The theory is
scalable, so that it can be applied in any wavelength range : optical, IR,
radiofrequency, etc. depending only on the characteristic space scales. Several
applications will be presented, concerning the reflection properties of such
films (broadband anti-reflection, or dichroic coatings) or to the propagation
and transmission through the film. We will show that depending on the type of
space dependence, an incident wave can either propagate or tunnel through such
films. We will investigate the behaviour of the light group-velocity and
tunneling time inside or through such films. Though we can reproduce the
phase-time saturation corresponding to the Hartman effect, analysis of the
group velocity in the tunneling case shows no sign of superluminal propagation.
A strong frequency dependence can be obtained in some situations, which allows
to anticipate a strong reshaping of brodband laser pulses.


title: Comments on "Oriental magic mirrors and the Laplacian image"

abstract:
  We make some remarks on Berry's paper [{\it Eur. J. Phys.} 27 (2006)
109-118].


title:
Astrobiological significance of minerals on Mars surface environment:
  UV-shielding properties of Fe (jarosite) vs. Ca (gypsum) sulphates

abstract:
  The recent discovery of liquid water-related sulphates on Mars is of great
astrobiological interest. UV radiation experiments, using natural Ca and Fe
sulphates (gypsum, jarosite), coming from two selected areas of SE Spain
(Jaroso Hydrothermal System and the Sorbas evaporitic basin), were performed
using a Xe Lamp with an integrated output from 220 nm to 500 nm of 1.2 Wm-2.
The results obtained demonstrate a large difference in the UV protection
capabilities of both minerals and also confirm that the mineralogical
composition of the Martian regolith is a crucial shielding factor. Whereas
gypsum showed a much higher transmission percentage, jarosite samples, with a
thickness of only 500 microns, prevented transmission. This result is extremely
important for the search for life on Mars as: a) jarosite typically occurs on
Earth as alteration crusts and patinas, and b) a very thin crust of jarosite on
the surface of Mars would be sufficient to shield microorganisms from UV
radiation.


title: Single-impulse magnetic focusing of launched cold atoms

abstract:
  We have theoretically investigated the focusing of a launched cloud of cold
atoms. Time-dependent spatially-varying magnetic fields are used to impart
impulses leading to a three-dimensional focus of the launched cloud. We discuss
possible coil arrangements for a new focusing regime: isotropic 3D focusing of
atoms with a single-impulse magnetic lens. We investigate focusing aberrations
and find that, for typical experimental parameters, the widely used assumption
of a purely harmonic lens is often inaccurate. The baseball lens offers the
best possibility for isotropically focusing a cloud of weak-field-seeking atoms
in 3D.


title: Towards electron encapsulation. Polynitrile approach

abstract:
  Is it possible to design a supramolecular cage that would "solvate" the
excess electron in the same fashion in which several solvent molecules do that
co-operatively in polar liquids? Two general strategies are outlined for
"electron encapsulation," viz. electron localization using polar groups
arranged on the (i) inside of the cage or (ii) outside of the cage. The second
approach is limited to polynitriles. We demonstrate that the latter faces a
formidable problem: the electron attaches to the nitrile groups forming
molecular anions with bent C-C-N fragments. Since the energy cost of this
bending is very high, for dinitrile anions in n-hexane, the binding energies
for the electron are very low and for mononitriles, these binding energies are
lower still, and the entropy of electron attachment is anomalously small.
Density functional theory modeling of electron trapping by mononitriles in
n-hexane suggests that the mononitrile molecules substitute for the solvent
molecules at the electron cavity, "solvating" the electron by their methyl
groups. Such "solvated electrons" resemble multimer radical anions in which the
electron density is shared (mainly) between C 2p orbitals in the solute/solvent
molecules, instead of existing as cavity electrons. The way in which the excess
electron density is shared by such molecules is similar to the way in which
this sharing occurs in large di- and poly- nitrile anions, such as
1,2,4,5,7,8,10,11-octacyano-cyclododecane anion. The work thus reveals
limitations of the concept of "solvated electron" for organic liquids. It also
demostrates the feasibility of "electron encapsulation."


title: What is the most competitive sport?

abstract:
  We present an extensive statistical analysis of the results of all sports
competitions in five major sports leagues in England and the United States. We
characterize the parity among teams by the variance in the winning fraction
from season-end standings data and quantify the predictability of games by the
frequency of upsets from game results data. We introduce a mathematical model
in which the underdog team wins with a fixed upset probability. This model
quantitatively relates the parity among teams with the predictability of the
games, and it can be used to estimate the upset frequency from standings data.
We propose the likelihood of upsets as a measure of competitiveness.


title: On The Structure of Competitive Societies

abstract:
  We model the dynamics of social structure by a simple interacting particle
system. The social standing of an individual agent is represented by an
integer-valued fitness that changes via two offsetting processes. When two
agents interact one advances: the fitter with probability p and the less fit
with probability 1-p. The fitness of an agent may also decline with rate r.
  From a scaling analysis of the underlying master equations for the fitness
distribution of the population, we find four distinct social structures as a
function of the governing parameters p and r. These include: (i) a static
lower-class society where all agents have finite fitness; (ii) an
upwardly-mobile middle-class society; (iii) a hierarchical society where a
finite fraction of the population belongs to a middle class and a complementary
fraction to the lower class; (iv) an egalitarian society where all agents are
upwardly mobile and have nearly the same fitness. We determine the basic
features of the fitness distributions in these four phases.


title:
Demonstration of a controllable three-dimensional Brownian motor in
  symmetric potentials

abstract:
  We demonstrate a Brownian motor, based on cold atoms in optical lattices,
where isotropic random fluctuations are rectified in order to induce controlled
atomic motion in arbitrary directions. In contrast to earlier demonstrations of
ratchet effects, our Brownian motor operates in potentials that are spatially
and temporally symmetric, but where spatiotemporal symmetry is broken by a
phase shift between the potentials and asymmetric transfer rates between them.
The Brownian motor is demonstrated in three dimensions and the noise-induced
drift is controllable in our system.


title: Multipole-mode solitons in Bessel optical lattices

abstract:
  We study basic properties of quiescent and rotating multipole-mode solitons
supported by axially symmetric Bessel lattices in a medium with defocusing
cubic nonlinearity. The solitons can be found in different rings of the lattice
and are stable when the propagation constant exceeds the critical value,
provided that the lattice is deep enough. In a high-power limit the
multipole-mode solitons feature a multi-ring structure.


title: Introduction to tensorial resistivity probability tomography

abstract:
  The probability tomography approach developed for the scalar resistivity
method is here extended to the 2D tensorial apparent resistivity acquisition
mode. The rotational invariant derived from the trace of the apparent
resistivity tensor is considered, since it gives on the datum plane anomalies
confined above the buried objects. Firstly, a departure function is introduced
as the difference between the tensorial invariant measured over the real
structure and that computed for a reference uniform structure. Secondly, a
resistivity anomaly occurrence probability (RAOP) function is defined as a
normalised crosscorrelation involving the experimental departure function and a
scanning function derived analytically using the Frechet derivative of the
electric potential for the reference uniform structure. The RAOP function can
be calculated in each cell of a 3D grid filling the investigated volume, and
the resulting values can then be contoured in order to obtain the 3D
tomographic image. Each non-vanishing value of the RAOP function is interpreted
as the probability which a resistivity departure from the reference resistivity
obtain in a cell as responsible of the observed tensorial apparent resistivity
dataset on the datum plane. A synthetic case shows that the highest RAOP values
correctly indicate the position of the buried objects and a very high spacial
resolution can be obtained even for adjacent objects with opposite resistivity
contrasts with respect to the resistivity of the hosting matrix. Finally, an
experimental field case dedicated to an archaeological application of the
resistivity tensor method is presented as a proof of the high resolution power
of the probability tomography imaging, even when the data are collected in
noisy open field conditions.


title:
Analytical expressions for the longitudinal evolution of nondiffracting
  pulses truncated by finite apertures

abstract:
  In this paper, starting from some general and plausible assumptions based on
geometrical optics and on a common feature of the truncated Bessel beams, a
heuristic derivation is presented of very simple analytical expressions,
capable of describing the longitudinal (on-axis) evolution of axially-symmetric
nondiffracting pulses when truncated by finite apertures. We apply our
analytical formulation to several situations involving subluminal, luminal or
superluminal localized pulses and compare the results with those obtained by
numerical simulations of the Rayleigh-Sommerfeld diffraction integrals. The
results are in excellent agreement. The present approach can be very useful,
because it can yield, in general, closed analytical expressions, avoiding the
need of time-consuming numerical simulations, and also because such expressions
provide a powerful tool for exploring several important properties of the
truncated localized pulses, as their depth of fields, the longitudinal pulse
behavior, the decaying rates, and so on.


title: Saturable absorption and 'slow light'

abstract:
  Quantitative evaluation of some recent 'slow light' experiments based on
coherent population oscillations (CPO) shows that they can be more simply
interpreted as saturable absorption phenomena. Therefore they do not provide an
unambiguous demonstration of 'slow light'. Indeed a limiting condition on the
spectral bandwidth is not generally satisfied, such that the requirements for
burning a narrow spectral hole in the homogeneously broadened absorption line
are not met. Some definitive tests of 'slow light' phenomena are suggested,
derived from analysis of phase shift and pulse delay for a saturable absorber


title:
Generation of multiple power-balanced laser beams for quantum-state
  manipulation experiments with phase-stable double optical lattices

abstract:
  We present a method to obtain power-balanced laser beams for doing
quantum-state manipulation experiments with phase-stable double optical
lattices. Double optical lattices are constructed using four pairs of
overlapped laser beams with different frequency. Our optical scheme provides a
phase stability between the optical lattices of 5 mrad/s and laser beams with a
very clean polarisation state resulting in a power imbalance in the individual
laser beams of less than 1%.


title: Double-impulse magnetic focusing of launched cold atoms

abstract:
  We have theoretically investigated 3D focusing of a launched cloud of cold
atoms using a pair of magnetic lens pulses (the alternate-gradient method).
Individual lenses focus radially and defocus axially or vice-versa. The
performance of the two possible pulse sequences are compared and found to be
ideal for loading both 'pancake' and 'sausage' shaped magnetic/optical
microtraps. It is shown that focusing aberrations are considerably smaller for
double-impulse magnetic lenses compared to single-impulse magnetic lenses. An
analysis of the clouds focused by double-impulse technique is presented.


title:
On the recollision-free excitation of krypton during ultrafast
  multi-electron tunnel ionization

abstract:
  The probability of multiple ionization of krypton by 50 femtosecond
circularly polarized laser pulses, independent of the optical focal geometry,
has been obtained for the first time. The excellent agreement over the
intensity range 10 TWcm-2 to 10 PWcm-2 with the recent predictions of A. S.
Kornev et al [Phys. Rev. A v.68, art.043414 (2003)] provides the first
experimental confirmation that non-recollisional electronic excitation can
occur in strong field ionization. This is particularly true for higher stages
of ionization, when the laser intensity exceeds 1 PWcm-2 as the energetic
departure of the ionized electron(s) diabatically distorts the wavefunctions of
the bound electrons. By scaling the probability of ionization by the focal
volume, we discusses why this mechanism was not apparent in previous studies.


title: The Spectrometer System for Measuring ZEUS Luminosity at HERA

abstract:
  The upgrade of the HERA accelerator has provided much increased collider
luminosity. In turn, the improvements have necessitated a new design for the
ZEUS luminosity measurements. The intense synchrotron radiation field, as well
as the high probability of a bremsstrahlung photon in each bunch crossing,
posed new experimental constraints. In this report, we describe how these
challenges were met with the ZEUS luminosity spectrometer system. The design,
testing and commissioning of the device are described, and the results from the
initial operational experience are reported.


title: Geophysical tomography in engineering geology: an overview

abstract:
  An overview of the tomographic interpretation method in engineering
geophysics is presented, considering the two approaches of the deterministic
tomography inversion, developed for rock elasticity analysis, and the
probability tomography imaging developed in the domain of potential fields
methods. The theoretical basis of both approaches is shortly outlined before
showing a laboratory and a field application.


title: Effects of Economic Interactions on Credit Risk

abstract:
  We study a credit risk model which captures effects of economic interactions
on a firm's default probability. Economic interactions are represented as a
functionally defined graph, and the existence of both cooperative, and
competitive, business relations is taken into account. We provide an analytic
solution of the model in a limit where the number of business relations of each
company is large, but the overall fraction of the economy with which a given
company interacts may be small. While the effects of economic interactions are
relatively weak in typical (most probable) scenarios, they are pronounced in
situations of economic stress, and thus lead to a substantial fattening of the
tails of loss distributions in large loan portfolios. This manifests itself in
a pronounced enhancement of the Value at Risk computed for interacting
economies in comparison with their non-interacting counterparts.


title: Digital resolution enhancement in surface plasmon microscopy

abstract:
  The use of photonic crystal and negative refractive index materials is known
to improve resolution of optical microscopy and lithography devices down to 80
nm level. Here we demonstrate that utilization of well-known digital image
recovery techniques allows us to further improve resolution of optical
microscope down to 30 nm level. Our microscope is based on a flat dielectric
mirror deposited onto an array of nanoholes in thin gold film. This
two-dimensional photonic crystal mirror may have either positive or negative
effective refractive index as perceived by surface plasmon polartions in the
visible frequency range. The optical images formed by the mirror are enhanced
using simple digital filters.


title: Correcting for Distortions due to Ionization in the STAR TPC

abstract:
  Physics goals of the STAR Experiment at RHIC in recent (and future) years
drive the need to operate the STAR TPC at ever higher luminosities, leading to
increased ionization levels in the TPC gas. The resulting ionic space charge
introduces field distortions in the detector which impact tracking performance.
Further complications arise from ionic charge leakage into the main TPC volume
from the high gain anode region. STAR has implemented corrections for these
distortions based on measures of luminosity, which we present here.
Additionally, we highlight a novel approach to applying the corrections on an
event-by-event basis applicable in conditions of rapidly varying ionization
sources.


title: Observations on teaching first-year physics

abstract:
  Highly successful students, as measured by grades and by scores on the Force
Concept Inventory, still struggle with fundamental concepts in mathematics and
physics. These difficulties, which turn physics into parrot learning and
include confusing velocity and acceleration or being unable to reason with
graphs, are revealed by problems requiring estimation and conceptual reasoning.
I discuss these problems, the difficulties that they reveal, and suggest
possible remedies.


title:
A nonadiabatic semi-classical method for dynamics of atoms in optical
  lattices

abstract:
  We develop a semi-classical method to simulate the motion of atoms in a
dissipative optical lattice. Our method treats the internal states of the atom
quantum mechanically, including all nonadiabatic couplings, while position and
momentum are treated as classical variables. We test our method in the
one-dimensional case. Excellent agreement with fully quantum mechanical
simulations is found. Our results are much more accurate than those of earlier
semi-classical methods based on the adiabatic approximation.


title: Michelson-Morley experiment revisited

abstract:
  The idea of the Michelson-Morley experiment is theoretically reanalyzed.
Elementary arguments are put forward to precisely derive the most general
allowable form of the directional dependence of the one-way velocity of light.


title:
Integrated structural and functional optical imaging combining
  spectral-domain optical coherence and multiphoton microscopy

abstract:
  An integrated microscope that combines different optical techniques for
simultaneous imaging is demonstrated. The microscope enables spectral-domain
optical coherence microscopy based on optical backscatter, and multi-photon
microscopy for the detection of two-photon fluorescence and second harmonic
generation signals. The unique configuration of this integrated microscope
allows for the simultaneous acquisition of both anatomical (structural) and
functional imaging information with particular emphasis for applications in the
fields of tissue engineering and cell biology. In addition, the contemporary
analysis of the spectroscopic features can enhance contrast by differentiating
among different tissue components.


title:
Application of the zero-range potential model to positron annihilation
  on molecules

abstract:
  In this paper we use a zero-range potential (ZRP) method to model positron
interaction with molecules. This allows us to investigate the effect of
molecular vibrations on positron-molecule annihilation using the van der Waals
dimer Kr2 as an example. We also use the ZRP to explore positron binding to
polyatomics and examine the dependence of the binding energy on the size of the
molecule for alkanes. We find that a second bound state appears for a molecule
with ten carbons, similar to recent experimental evidence for such a state
emerging in alkanes with twelve carbons.


title:
Characteristic time scales of tick quotes on foreign currency markets:
  an empirical study and agent-based model

abstract:
  Power spectrum densities for the number of tick quotes per minute (market
activity) on three currency markets (USD/JPY, EUR/USD, and JPY/EUR) for periods
from January 1999 to December 2000 are analyzed. We find some peaks on the
power spectrum densities at a few minutes. We develop the double-threshold
agent model and confirm that stochastic resonance occurs for the market
activity of this model. We propose a hypothesis that the periodicities found on
the power spectrum densities can be observed due to stochastic resonance.


title: Binding effects in multivalent Gibbs-Donnan equilibrium

abstract:
  The classical Gibbs-Donnan equilibrium describes excess osmotic pressure
associated with confined colloidal charges embedded in an electrolyte solution.
In this work, we extend this approach to describe the influence of multivalent
ion binding on the equilibrium force acting on a charged rod translocating
between two compartments, thereby mimicking ionic effects on force balance
during in vitro DNA ejection from bacteriophage. The subtle interplay between
Gibbs-Donnan equilibrium and adsorption equilibrium leads to a non-monotonic
variation of the ejection force as multivalent salt concentration is increased,
in qualitative agreement with experimental observations.


title: On the Lamb Vector and the Hydrodynamic Charge

abstract:
  This work is an attempt to test the concept of hydrodynamic charge (analogous
to the electric charge in Electromagnetism) in the simple case of a coherent
structure such as the Burgers vortex. We provide experimental measurements of
both the so-called Lamb vector and its divergence (the charge) by
two-dimensional Particle Image Velocimetry. In addition, we perform a
Helmholtz-Hodge decomposition of the Lamb vector in order to explore its
topological features. We compare the charge with the well-known Q criterion in
order to assess its interest in detecting and characterizing coherent
structure. Usefulness of this concept in studies of vortex dynamics is
demonstrated.


title: A Dust Universe Solution to the Dark Energy Problem

abstract:
  Astronomical measurements of the Omegas for mass density, cosmological
constant lambda and curvature k are shown to be sufficient to produce a unique
and detailed cosmological model describing dark energy influences based on the
Friedman equations. The equation of state Pressure turns out to be identically
zero at all epochs as a result of the theory. The partial omega, for dark
energy, has the exact value, minus unity, as a result of the theory and is in
exact agreement with the astronomer's measured value. Thus this measurement is
redundant as it does not contribute to the construction of the theory for this
model. Rather, the value of this omega is predicted from the theory. The model
has the characteristic of changing from deceleration to acceleration at exactly
half the epoch time at which the input measurements are taken. This is a
mysterious feature of the model for which no explanation has so far been found.
An attractive feature of the model is that the acceleration change time occurs
at a red shift of approximately 0.8 as predicted by the dark energy workers.
Using a new definition of dark energy density it is shown that the contribution
of this density to the acceleration process is via a negative value for the
gravitational constant, -G, exactly on a par with gravitational mass which
occurs via the usual positive value for G. This paper also contains an appendix
on dark energy dynamics with its own abstract.


title: Perfect Tempering

abstract:
  Multimodal structures in the sampling density (e.g. two competing phases) can
be a serious problem for traditional Markov Chain Monte Carlo (MCMC), because
correct sampling of the different structures can only be guaranteed for
infinite sampling time. Samples may not decouple from the initial configuration
for a long time and autocorrelation times may be hard to determine.
  We analyze a suitable modification (C. J. Geyer and E. A. Thompson, J. Amer.
Statist. Assoc., 90, 909, 1995) of the simulated tempering idea (E. Marinari
and G. Parisi, Europhys. Lett. 19, 451, 1992), which has orders of magnitude
smaller autocorrelation times for multimodal sampling densities and which
samples all peaks of multimodal structures according to their weight. The
method generates exact, i.e. uncorrelated, samples and thus gives access to
reliable error estimates. Exact tempering is applicable to arbitrary
(continuous or discreet) sampling densities and moreover presents a possibility
to calculate integrals over the density (e.g. the partition function for the
Boltzmann distribution), which are not accessible by usual MCMC.


title: Gravity currents in a porous medium at an inclined plane

abstract:
  We consider the release from a point source of relatively heavy fluid into a
porous saturated medium above an impermeable slope. We consider the case where
the volume of the resulting gravity current increases with time like $t^\alpha$
and show that for $\alpha<3$, at short times the current spreads
axisymmetrically, with radius $r\sim t^{(\alpha+1)/4}$, while at long times it
spreads predominantly downslope. In particular, for long times the downslope
position of the current scales like $t$ while the current extends a distance
$t^{\alpha/3}$ across the slope. For $\alpha>3$, this situation is reversed
with spreading occurring predominantly downslope for short times. The governing
equations admit similarity solutions whose scaling behaviour we determine, with
the full similarity form being evaluated by numerical computations of the
governing partial differential equation. We find that the results of these
analyses are in good quantitative agreement with a series of laboratory
experiments. Finally, we briefly discuss the implications of our work for the
sequestration of carbon dioxide in aquifers with a sloping, impermeable cap.


title: Volatility of an Indian stock market : A random matrix approach

abstract:
  We examine volatility of an Indian stock market in terms of aspects like
participation, synchronization of stocks and quantification of volatility using
the random matrix approach. Volatility pattern of the market is found using the
BSE index for the three-year period 2000-2002. Random matrix analysis is
carried out using daily returns of 70 stocks for several time windows of 85
days in 2001 to (i) do a brief comparative analysis with statistics of
eigenvalues and eigenvectors of the matrix C of correlations between price
fluctuations, in time regimes of different volatilities. While a bulk of
eigenvalues falls within RMT bounds in all the time periods, we see that the
largest (deviating) eigenvalue correlates well with the volatility of the
index, the corresponding eigenvector clearly shows a shift in the distribution
of its components from volatile to less volatile periods and verifies the
qualitative association between participation and volatility (ii) observe that
the Inverse participation ratio for the 'last' eigenvector is sensitive to
market fluctuations (the two quantities are observed to anti correlate
significantly) (iii) set up a variability index, V whose temporal evolution is
found to be significantly correlated with the volatility of the overall market
index.


title:
Active Amplification of the Terrestrial Albedo to Mitigate Climate
  Change: An Exploratory Study

abstract:
  This study explores the potential to enhance the reflectance of solar
insolation by the human settlement and grassland components of the Earth's
terrestrial surface as a climate change mitigation measure. Preliminary
estimates derived using a static radiative transfer model indicate that such
efforts could amplify the planetary albedo enough to offset the current global
annual average level of radiative forcing caused by anthropogenic greenhouse
gases by as much as 30 percent or 0.76 W/m2. Terrestrial albedo amplification
may thus extend, by about 25 years, the time available to advance the
development and use of low-emission energy conversion technologies which
ultimately remain essential to mitigate long-term climate change. However,
additional study is needed to confirm the estimates reported here and to assess
the economic and environmental impacts of active land-surface albedo
amplification as a climate change mitigation measure.


title: The Timing System for the CDF Electromagnetic Calorimeters

abstract:
  We report on the design and performance of the electromagnetic calorimeter
timing readout system (EMTiming) for the Collider Detector at Fermilab (CDF).
The system will be used in searches for rare events with high energy photons to
verify that the photon is in time with the event collision, to reject cosmic
ray and beam halo backgrounds, and to allow direct searches for new heavy
long-lived particles that decay to photons. The installation and commissioning
of all 862 channels was completed in Fall 2004 as part of an upgrade to the Run
II version of the detector. Using in-situ data, including electrons from W=>e
nu and Z => ee decays, we measure the energy threshold for a time to be
recorded to be 3.8 \pm 0.3GeV in the central portion of the detector and 1.9
\pm 0.1 GeV in the plug portion. Similarly, we measure a timing resolution of
600 \pm 10 ps and 610 \pm 10 ps for electrons above 10 GeV and 6 GeV
respectively. There are very few system pathologies such as recording a time
when no energy is deposited, or recording a second, fake time for a single
energy deposit.


title:
Analytical Hartree-Fock gradients with respect to the cell parameter:
  systems periodic in one and two dimensions

abstract:
  Analytical Hartree-Fock gradients with respect to the cell parameter have
been implemented in the electronic structure code CRYSTAL, for the case of one
and two-dimensional periodicity. As in most molecular codes, Gaussian type
orbitals are used to express the wavefunction. Examples demonstrate that the
gradients have a good accuracy.


title:
Comments on "Viscosity of high crystal content melts: dependence on
  solid fraction"

abstract:
  Here we propose a simple modification of the parameterisation presented in
Costa (2005) [Viscosity of high crystal content melts: dependence on solid
fraction, Geophys. Res. Lett., 32, 2005] which improves all the main positive
features of it, yet at the same time, does not show a plateau region as the
solid fraction tends to 1, generally increases the performance of the model,
and exactly recovers the classical well established relationships valid for
small fractions.


title: Una lezione particolare di Ettore Majorana

abstract:
  We give, for the first time, the critical complete text of a manuscript by
Ettore Majorana, conserved in the same file of the lecture notes for his course
on Theoretical Physics at the University of Naples. He probably refers to a
seminar delivered in that University. Some passages reveal a physical
interpretation of the Quantum Mechanics which anticipates of several years the
Feynman approach in terms of path integrals, independently of the underlying
mathematical formulation.

categories: physics.hist-ph hep-ph hep-th physics.pop-ph


title: Many-body theory of gamma spectra from positron-atom annihilation

abstract:
  A many-body theory approach to the calculation of gamma spectra of positron
annihilation on many-electron atoms is developed. We evaluate the first-order
correlation correction to the annihilation vertex and perform numerical
calculations for the noble gas atoms. Extrapolation with respect to the maximal
orbital momentum of the intermediate electron and positron states is used to
achieve convergence. The inclusion of correlation corrections improves
agreement with experimental gamma spectra.


title: Positronium formation from valence and inner shells in noble gas atoms

abstract:
  When recent experimental positronium (Ps) formation cross sections in noble
gases have been compared with the most up-to date theoretical studies, the
agreement is qualitative, but not quantitative. In this paper we re-examine
this process and show that at low energies Ps formation must be treated
nonperturbatively. We also look at Ps formation with inner shell electrons.


title:
Protection against the man-in-the-middle-attack for the
  Kirchhoff-loop-Johnson(-like)-noise cipher and expansion by voltage-based
  security

abstract:
  It is shown that the original Kirchhoff-loop-Johnson(-like)-noise (KLJN)
cipher is naturally protected against the man-in-the-middle (MITM) attack, if
the eavesdropper is using resistors and noise voltage generators just like the
sender and the receiver. The eavesdropper can extract zero bit of information
before she is discovered. However, when the eavesdropper is using noise current
generators, though the cipher is protected, the eavesdropper may still be able
to extract one bit of information while she is discovered. For enhanced
security, we expand the KLJN cipher with the comparison of the instantaneous
voltages via the public channel. In this way, the sender and receiver has a
full control over the security of measurable physical quantities in the
Kirchhoff-loop. We show that when the sender and receiver compare not only
their instantaneous current data but also their instantaneous voltage data then
the zero-bit security holds even for the noise current generator case. We show
that the original KLJN scheme is also zero-bit protected against that type of
MITM attack when the eavesdropper uses voltage noise generators, only. In
conclusion, within the idealized model scheme, the man-in-the-middle-attack
does not provide any advantage compared to the regular attack considered
earlier. The remaining possibility is the attack by a short, large current
pulse, which described in the original paper as the only efficient type of
regular attacks, and that yields the one bit security. In conclusion, the KLJN
cipher is superior to known quantum communication schemes in every respect,
including speed, robustness, maintenance need, price and its natural immunity
against the man-in-the-middle attack.


title:
Quantum Field and Cosmic Field-Finite Geometrical Field Theory of Matter
  Motion Part Three

abstract:
  This research establishes an operational measurement way to express the
quantum field theory in a geometrical form. In four-dimensional spacetime
continuum, the orthogonal rotation is defined. It forms two sets of equations:
one set is geometrical equations, another set is the motion equations. The
Lorentz transformation can be directly derived from the geometrical equations,
and the proper time of general relativity is well expressed by time
displacement field. By the motion equations, the typical time displacement
field of matter motion is discussed. The research shows that the quantum field
theory can be established based on the concept of orthogonal rotation. On this
sense, the quantum matter motion in physics is viewed as the orthogonal
rotation of spacetime continuum. In this paper, it shows that there are three
typical quantum solutions. One is particle-like solution, one is
generation-type solution, and one is pure wave type solution. For each typical
solution, the force fields are different. Many features of quantum field can be
well explained by this theoretic form. Finally, the general matter motion is
discussed, the main conclusions are: (1). Geometrically, cosmic vacuum field
can be described by the curvature spacetime; (2). The spatial deformation of
planet is related with a planet electromagnetic field; (3). For electric charge
less matter, the volume of matter will be expanding infinitely; (4).For strong
electric charge matter, it shows that the volume of matter will be contracting
infinitely.


title:
Reexamination of Barnett's Experiment Based on the Modified Lorentz
  Force Law

abstract:
  Barnett's experiment demonstrates that the induction on a stationary
cylindrical capacitor in the presence of a rotating magnet or solenoid is zero.
In this investigation, based on the modified Lorentz force law, which complies
with Galilean transformations and depends on relative velocities, the induction
on the capacitor is reexamined. When the rotating solenoid is long and the
capacitor is placed inside the solenoid, it is seen that the induction actually
vanishes as observed in Barnett's experiment. However, when the capacitor is
placed outside the solenoid or when the solenoid is short, it is shown that the
induction can departure from zero. This prediction provides a means to test the
validity of the modified Lorentz force law.


title:
Low-degree mantle convection with strongly temperature- and
  depth-dependent viscosity in a three-dimensional spherical shell

abstract:
  A series of numerical simulations of thermal convection of Boussinesq fluid
with infinite Prandtl number, with Rayleigh number $10^7$, and with the
strongly temperature- and depth- dependent viscosity in a three-dimensional
spherical shell is carried out to study the mantle convection of single-plate
terrestrial planets like Venus or Mars without an Earth-like plate tectonics.
The strongly temperature-dependent viscosity (the viscosity contrast across the
shell is $\geq 10^5$) make the convection under stagnant-lid short-wavelength
structures. Numerous, cylindrical upwelling plumes are developed because of the
secondary downwelling plumes arising from the bottom of lid. This convection
pattern is inconsistent with that inferred from the geodesic observation of the
Venus or Mars. Additional effect of the stratified viscosity at the upper/lower
mantle (the viscosity contrast is varied from 30 to 300) are investigated. It
is found that the combination of the strongly temperature- and depth-dependent
viscosity causes long-wavelength structures of convection in which the
spherical harmonic degree $\ell$ is dominant at 1--4. The geoid anomaly
calculated by the simulated convections shows a long-wavelength structure,
which is compared with observations. The degree-one ($\ell = 1$) convection
like the Martian mantle is realized in the wide range of viscosity contrast
from 30 to 100 when the viscosity is continuously increased with depth at the
lower mantle.


title:
Modelling dynamics of samples exposed to free-electron-laser radiation
  with Boltzmann equations

abstract:
  We apply Boltzmann equations for modelling the radiation damage in samples
irradiated by photons from free electron laser (FEL). We test this method in a
study case of a spherically symmetric xenon cluster irradiated with VUV FEL
photons. The results obtained demonstrate the potential of the Boltzmann method
for describing the complex and non-equilibrium dynamics of samples exposed to
FEL radiation.


title: Thermoeconomic analysis of an irreversible Stirling heat pump cycle

abstract:
  In this paper an analysis of the Stirling cycle in thermoeconomic terms is
developed using the entropy generation. In the thermoeconomic optimization of
an irreversible Stirling heat pump cycle the F function has been introduced to
evaluate the optimum for the higher and lower sources temperature ratio in the
cycle: this ratio represents the value which optimizes the cycle itself. The
variation of the function F is proportional to the variation of the entropy
generation, the maxima and minima of F has been evaluated in a previous paper
without giving the physical foundation of the method. We investigate the
groundwork of this approach: to study the upper and lower limits of F function
allows to determine the cycle stability and the optimization conditions. The
optimization consists in the best COP at the least cost. The principle of
maximum variation for the entropy generation becomes the analytic foundation of
the optimization method in the thermoeconomic analysis for an irreversible
Stirling heat pump cycle.
  Pacs: 89.65.G, 05.70 keywords: entropy generation, finite time
Thermodynamics, Stirling cycle, Thermodynamic optimization.


title: Atomic Bremsstrahlung: retrospectives, current status and perspectives

abstract:
  We describe here the Atomic bremsstrahlung - emission of continuous spectrum
electromagnetic radiation, which is generated in collisions of particles that
have internal deformable structure that includes positively and negatively
charged constituents. The deformation of one of or both colliding partners
induces multiple, mainly dipole, time-dependent electrical moments that become
a source of radiation. The history of Atomic bremsstrahlung invention is
presented and it's unusual in comparison to ordinary bremsstrahlung properties
are discussed. As examples, fast electron - atom, non-relativistic and
relativistic collisions are considered. Attention is given to ion - atom and
atom - atom collisions. Specifics of elastic and inelastic (i.e. radiation
accompanied by destruction of collision partners) Atomic bremsstrahlung will be
mentioned. Attention will be given to possible manifestation of Atomic
bremsstrahlung in Nature and in some exotic systems, for instance scattering of
electrons upon muonic hydrogen. Some cooperative effects connected to Atomic
bremsstrahlung will be considered. New classical schemes similar to Atomic
bremsstrahlung will be presented.


title:
Coupled atomic-molecular condensates in a double-well potential:
  decaying molecular oscillations

abstract:
  We present a four-mode model that describes coherent photo-association (PA)
in a double-well Bose-Einstein condensate, focusing on the $average$ molecular
populations in certain parameters. Our numerical results predict an interesting
strong-damping effect of molecular oscillations by controlling the particle
tunnellings and PA light strength, which may provide a promising way for
creating a stable molecular condensate via coherent PA in a magnetic
double-well potential.


title: Cylindrical Korteweg-de Vries solitons on a ferrofluid surface

abstract:
  Linear and non-linear surface waves on a ferrofluid cylinder surrounding a
current-carrying wire are investigated. Suppressing the Rayleigh-Plateau
instability of the fluid column by the magnetic field of a sufficiently large
current in the wire axis-symmetric surface deformations are shown to propagate
without dispersion in the long wavelength limit. Using multiple scale
perturbation theory the weakly non-linear regime may be described by a
Korteweg-de Vries equation with coefficients depending on the magnetic field
strength. For different values for the current in the wire hence different
solutions such as hump or hole solitons may be generated. The possibility to
observe these structures in experiments is also elucidated.


title:
Inferring mixed-culture growth from total biomass data in a wavelet
  approach

abstract:
  It is shown that the presence of mixed-culture growth in batch fermentation
processes can be very accurately inferred from total biomass data by means of
the wavelet analysis for singularity detection. This is accomplished by
considering simple phenomenological models for the mixed growth and the more
complicated case of mixed growth on a mixture of substrates. The main quantity
provided by the wavelet analysis is the Holder exponent of the singularity that
we determine for our illustrative examples. The numerical results point to the
possibility that Holder exponents can be used to characterize the nature of the
mixed-culture growth in batch fermentation processes with potential industrial
applications. Moreover, the analysis of the same data affected by the common
additive Gaussian noise still lead to the wavelet detection of the
singularities although the Holder exponent is no longer a useful parameter


title:
Prisoner's Dilemma cellular automata revisited: evolution of cooperation
  under environmental pressure

abstract:
  We propose an extension of the evolutionary Prisoner's Dilemma cellular
automata, introduced by Nowak and May \cite{nm92}, in which the pressure of the
environment is taken into account. This is implemented by requiring that
individuals need to collect a minimum score $U_{min}$, representing
indispensable resources (nutrients, energy, money, etc.) to prosper in this
environment. So the agents, instead of evolving just by adopting the behaviour
of the most successful neighbour (who got $U^{msn}$), also take into account if
$U^{msn}$ is above or below the threshold $U_{min}$. If $U^{msn}<U_{min}$ an
individual has a probability of adopting the opposite behaviour from the one
used by its most successful neighbour. This modification allows the evolution
of cooperation for payoffs for which defection was the rule (as it happens, for
example, when the sucker's payoff is much worse than the punishment for mutual
defection). We also analyse a more sophisticated version of this model in which
the selective rule is supplemented with a "win-stay, lose-shift" criterion. The
cluster structure is analyzed and, for this more complex version we found
power-law scaling for a restricted region in the parameter space.


title: Low-temperature antihydrogen-atom scattering

abstract:
  A simple method to include the strong force in atom-antiatom scattering is
presented. It is based on the strong-force scatteringn length between the
nucleon and antinucleon. Using this method elastic and annihilation cross
sections are calculated for hydrogen-antihydrogen and helium-antihydrogen
scattering. The results are compared to first-order perturbation theory using a
pseudo potential. The pseudo-potential approach works fairly well for
hydrogen-antihydrogen scattering, but fails for helium-antihydrogen scattering
where strong-force effects are more prominent.


title:
Meta-material photonic funnels for sub-diffraction light compression and
  propagation

abstract:
  We present waveguides with photonic crystal cores, supporting energy
propagation in subwavelength regions with a mode structure similar to that in
telecom fibers. We design meta-materials for near-, mid-, and far-IR
frequencies, and demonstrate efficient energy transfer to and from regions
smaller than 1/25-th of the wavelength. Both positive- and negative-refractive
index light transmissions are shown. Our approach, although demonstrated here
in circular waveguides for some specific frequencies, is easily scalable from
optical to IR to THz frequency ranges, and can be realized in a variety of
waveguide geometries. Our design may be used for ultra high-density energy
focusing, nm-resolution sensing, near-field microscopy, and high-speed
all-optical computing.


title: $\beta$-BaB$_2$O$_4$ deep UV monolithic walk-off compensating tandem

abstract:
  The generation of watt-level cw narrow-linewidth sources at specific deep UV
wavelengths corresponding to atomic cooling transitions usually employs
external cavity-enhanced second-harmonic generation (SHG) of moderate-power
visible lasers in birefringent materials. In this work, we investigate a novel
approach to cw deep-UV generation by employing the low-loss BBO in a monolithic
walkoff-compensating structure [Zondy {\it{et al}}, J. Opt. Soc. Am. B
{\bf{20}} (2003) 1675] to simultaneously enhance the effective nonlinear
coefficient while minimizing the UV beam ellipticity under tight focusing. As a
preliminary step to cavity-enhanced operation, and in order to apprehend the
design difficulties stemming from the extremely low acceptance angle of BBO, we
investigate and analyze the single-pass performance of a $L_c=8 $mm monolithic
walk-off compensating structure made of 2 optically-contacted BBO plates cut
for type-I critically phase-matched SHG of a cw $\lambda=570.4$nm dye laser. As
compared with a bulk crystal of identical length, a sharp UV efficiency
enhancement factor of 1.65 has been evidenced with the tandem structure, but at
$\sim-1$nm from the targeted fundamental wavelength, highlighting the
sensitivity of this technique when applied to a highly birefringent material
such as BBO. Solutions to angle cut residual errors are identified so as to
match accurately more complex periodic-tandem structure performance to any
target UV wavelength, opening the prospect for high-power, good beam quality
deep UV cw laser sources for atom cooling and trapping.


title:
Fluid simulation studies of the dynamical behaviour of one dimensional
  relativistic electromagnetic solitons

abstract:
  A numerical fluid simulation investigation of the temporal evolution of a
special class of traveling wave solution of the one dimensional relativistic
cold plasma model is reported.The solutions consist of coupled electromagnetic
and plasma waves in a solitary pulse shape (Phys. Rev. Lett. 68, 3172(1992);
Phys. Plasmas 9, 1820(2002)).Issues pertaining to their stability, mutual
collisional interactions and propagation in an inhomogeneous plasma medium are
addressed. It is found that solitary pulses that consist of a single light peak
trapped in a modulated density structure are long lived whereas structures with
multiple peaks of trapped light develop an instability at the trailing edge.
The interaction properties of two single peak structures show interesting
dependencies on their relative amplitudes and propagation speeds and can be
understood in terms of their propagation characteristics in an inhomogeneous
plasma medium.


title:
Monte Carlo based studies of a polarized positron source for
  International Linear Collider (ILC)

abstract:
  The full exploitation of the physics potential of an International Linear
Collider (ILC) requires the development of a polarized positron beam. New
concepts of polarized positron sources are based on the development of
circularly polarized photon sources. The polarized photons create
electron-positron pairs in a thin target and transfer their polarization state
to the outgoing leptons. To achieve a high level of positron polarization the
understanding of the production mechanisms in the target is crucial. Therefore
a general framework for the simulation of polarized processes with GEANT4 is
under development. In this contribution the current status of the project and
its application to a study of the positron production process for the ILC is
presented.