title:
The GNSS-R Eddy Experiment II: L-band and Optical Speculometry for
  Directional Sea-Roughness Retrieval from Low Altitude Aircraft

abstract:
  We report on the retrieval of directional sea-roughness (the full directional
mean square slope, including MSS, direction and isotropy) through inversion of
Global Navigation Satellite System Reflections (GNSS-R) and SOlar REflectance
Speculometry (SORES)data collected during an experimental flight at 1000 m. The
emphasis is on the utilization of the entire Delay-Doppler Map (for GNSS-R) or
Tilt Azimuth Map (for SORES) in order to infer these directional parameters.
Obtained estimations are analyzed and compared to Jason-1 measurements and the
ECMWF numerical weather model.


title:
Accurate spline solutions of the Dirac equation with
  parity-nonconserving potential

abstract:
  The complete system of the B-spline solutions for the Dirac equation with the
parity-nonconserving (PNC) weak interaction effective potential is obtained.
This system can be used for the accurate evaluation of the radiative
corrections to the PNC amplitudes in the multicharged ions and neutral atoms.
The use of the scaling procedure allows for the evaluation of the PNC matrix
elements with relative accuracy $10^{-7}$.


title: Nonlinear resonant wave interaction in vacuum

abstract:
  The basic equations governing propagation of electromagnetic and
gravitational waves in vacuum are nonlinear. As a consequence photon-photon
interaction as well as photon-graviton interaction can take place without a
medium. However, resonant interaction between less than four waves cannot occur
in vacuum, unless the interaction takes place in a bounded region, such as a
cavity or a waveguide. Recent results concerning resonant wave interaction in
bounded vacuum regions are reviewed and extended.


title:
Combined surface acoustic wave and surface plasmon resonance measurement
  of collagen and fibrinogen layers

abstract:
  We use an instrument combining optical (surface plasmon resonance) and
acoustic (Love mode acoustic wave device) real-time measurements on a same
surface for the identification of water content in collagen and fibrinogen
protein layers. After calibration of the surface acoustic wave device
sensitivity by copper electrodeposition, the bound mass and its physical
properties -- density and optical index -- are extracted from the complementary
measurement techniques and lead to thickness and water ratio values compatible
with the observed signal shifts. Such results are especially usefully for
protein layers with a high water content as shown here for collagen on an
hydrophobic surface. We obtain the following results: collagen layers include
70+/-20 % water and are 16+/-3 to 19+/-3 nm thick for bulk concentrations
ranging from 30 to 300 ug/ml. Fibrinogen layers include 50+/-10 % water for
layer thicknesses in the 6+/-1.5 to 13+/-2 nm range when the bulk concentration
is in the 46 to 460 ug/ml range.


title: Phonons and Magnetic Excitations in Mott-Insulator LaTiO$_3$

abstract:
  The polarized Raman spectra of stoichiometric LaTiO$_3$ (T$_N = 150$ K) were
measured between 6 and 300 K. In contrast to earlier report on half-metallic
LaTiO$_{3.02}$, neither strong background scattering, nor Fano shape of the
Raman lines was observed. The high frequency phonon line at 655 cm$^{-1}$
exhibits anomalous softening below T$_N$: a signature for structural
rearrangement. The assignment of the Raman lines was done by comparison to the
calculations of lattice dynamics and the nature of structural changes upon
magnetic ordering are discussed. The broad Raman band, which appears in the
antiferromagnetic phase, is assigned to two-magnon scattering. The estimated
superexchange constant $J = 15.4\pm0.5$ meV is in excellent agreement with the
result of neutron scattering studies.


title:
Comparative studies of the magnetic dipole and electric quadrupole
  hyperfine constants for the ground and low lying excited states of
  ^{25}Mg^{+}

abstract:
  We have employed the relativistic coupled cluster theory to calculate the
magnetic dipole and electric quadrupole hyperfine constants for the ground and
low lying excited states of singly ionized magnesium. Comparison with
experimental and the other theoretical results are done and predictions are
also made for a few low lying excited states which could be of interest. We
have made comparative studies of the important many body effects contributing
to the hyperfine constants for the different states of the ion.


title: A special kind of Casimir plates for making exotic matter

abstract:
  Herein a process of suitable extraction of energy from vacuum is introduced.
By followung Ridgely's idea[1], it is proposed some molecular fine-scale
plates. Then some properties of them are considered. In fact Casimir effect is
viewed in engineering manner. The introduced plates may be applied for support
of traversable wormholes (TWs) & warp drives (WDs).


title:
The secondary flow in a short aspect ratio circular lid driven cavity at
  small but finite Reynolds number

abstract:
  Regular perturbation solutions are obtained for the Stokes flow field, the
first order effects of inertia on the flow field, and the primary and secondary
pressure fields in the circular lid driven cavity. The physical mechanism that
causes vortex breakdown exists at small Reynolds number; it is a stagnation of
the secondary flow by an adverse pressure gradient. The discontinuity between
the rotating lid and the stationary sidewall has negligible influence on the
flow field provided that the inertial forcing of the secondary flow is not
localized near the boundary discontinuity, and the Reynolds number is small.


title:
The incomplete beta function law for parallel tempering sampling of
  classical canonical systems

abstract:
  We show that the acceptance probability for swaps in the parallel tempering
Monte Carlo method for classical canonical systems is given by a universal
function that depends on the average statistical fluctuations of the potential
and on the ratio of the temperatures. The law, called the incomplete beta
function law, is valid in the limit that the two temperatures involved in swaps
are close to one another. An empirical version of the law, which involves the
heat capacity of the system, is developed and tested on a Lennard-Jones
cluster. We argue that the best initial guess for the distribution of
intermediate temperatures for parallel tempering is a geometric progression and
we also propose a technique for the computation of optimal temperature
schedules. Finally, we demonstrate that the swap efficiency of the parallel
tempering method for condensed-phase systems decreases naturally to zero at
least as fast as the inverse square root of the dimensionality of the physical
system.


title: Helical filaments with varying cross section radius

abstract:
  The tridimensional configuration and the twist density of helical rods with
varying cross section radius are studied within the framework of the Kirchhoff
rod model. It is shown that the twist density increases when the cross section
radius decreases. Some tridimensional configurations of helix-like rods are
displayed showing the effects of the nonhomogeneity considered here. Since the
helix-like solutions of the nonhomogeneous rods do not present constant
curvature and torsion a set of differential equations for these quantities is
presented. We discuss the results and possible consequences.


title:
The dependence of relative dispersion on turbulence scales in Lagrangian
  Stochastic Models

abstract:
  The aim of the article is to investigate the relative dispersion properties
of the Well Mixed class of Lagrangian Stochastic Models. Dimensional analysis
shows that given a model in the class, its properties depend solely on a
non-dimensional parameter, which measures the relative weight of
Lagrangian-to-Eulerian scales. This parameter is formulated in terms of
Kolmogorov constants, and model properties are then studied by modifying its
value in a range that contains the experimental variability. Large variations
are found for the quantity $g^*=2gC_0^{-1}$, where $g$ is the Richardson
constant, and for the duration of the $t^3$ regime. Asymptotic analysis of
model behaviour clarifies some inconsistencies in the literature and excludes
the Ornstein-Uhlenbeck process from being considered a reliable model for
relative dispersion.


title: David Hilbert and the origin of the "Schwarzschild solution"

abstract:
  The very early dismissal of Schwarzschild's original solution and manifold,
and the rise, under Schwarzschild's name, of the inequivalent solution and
manifold found instead by Hilbert, are scrutinised and commented upon, in the
light of the subsequent occurrences.
  It is reminded that Hilbert's manifold suffers from two defects, that are
absent in Schwarzschild's manifold. It does not admit a consistent drawing of
the arrow of time, and it allows for an invariant, local, intrinsic singularity
in its interior. The former defect is remedied by the change of topology of the
extensions proposed by Synge, Kruskal and Szekeres. The latter persists
unaffected in the extensions, since it is of local character.


title: Three charged particles in the continuum. Astrophysical examples

abstract:
  We suggest a new adiabatic approach for description of three charged
particles in the continuum. This approach is based on the Coulomb-Fourier
transformation (CFT) of three body Hamiltonian, which allows to develop a
scheme, alternative to Born-Oppenheimer one.
  The approach appears as an expansion of the kernels of corresponding integral
transformations in terms of small mass-ratio parameter. To be specific, the
results are presented for the system $ppe$ in the continuum. The wave function
of a such system is compared with that one which is used for estimation of the
rate for triple reaction $ p+p+e\to d+\nu, $ which take place as a step of
$pp$-cycle in the center of the Sun. The problem of microscopic screening for
this particular reaction is discussed.


title:
When Density Functional Theory goes wrong and how to fix it: spin
  balanced unrestricted Kohn-Sham formalism

abstract:
  Kohn-Sham (KS) formalism of Density Functional Theory is modified to include
the systems with strong non-dynamic electron correlation. Unlike in extended KS
and broken symmetry unrestricted KS formalisms, cases of both singlet-triplet
and aufbau instabilities are covered, while preserving a pure spin-state. The
straightforward implementation is suggested, which consists of placing spin
constraints on complex unrestricted Hartree-Fock wave function. Alternative
approximate approach consists of using the perfect pairing implementation with
the natural orbitals of unrestricted KS method and square roots of their
occupation numbers as configuration weights without optimization, followed by a
posteriori exchange-correlation correction. The numerical results of this
approximation for the barrier to the internal rotation in ethylene are reported
to be in close agreement with experimental data.


title: The rules of coherence and other habits

abstract:
  Physics and mathematics are difficult enough without the aditional burden of
bad habits. In this article, we examine some helpful habits that tend to be
underemphasized by many physics teachers (mainly because they seem so
obvious!).


title: Frequentist Hypothesis Testing with Background Uncertainty

abstract:
  We consider the standard Neyman-Pearson hypothesis test of a
signal-plus-background hypothesis and background-only hypothesis in the
presence of uncertainty on the background-only prediction. Surprisingly, this
problem has not been addressed in the recent conferences on statistical
techniques in high-energy physics -- although the its confidence-interval
equivalent has been. We discuss the issues of power, similar tests, coverage,
and ordering rules. The method presented is compared to the Cousins-Highland
technique, the ratio of Poisson means, and ``profile'' method.


title: Generalized wall-functions for high-Reynolds-number turbulence models

abstract:
  Generalized wall-functions in application to high-Reynolds-number turbulence
models are derived. The wall-functions are based on transfer of a boundary
condition from a wall to some intermediate boundary near the wall (usually the
first nearest to a wall mesh point but that is not obligatory). The boundary
conditions on the intermediate boundary are of Robin-type and represented in a
differential form. The wall-functions are obtained in an analytical
easy-to-implement form, take into account source terms such as pressure
gradient and buoyancy forces, and do not include free parameters. The
log-profile assumption is not used in this approach. Both Dirichlet and Newman
boundary-value problems are considered. A method for complementing solution
near a wall is suggested. Although the generalized wall-functions are realized
for the k-epsilon model, generalization to other turbulence models looks quite
clear. The general approach suggested is applicable to studying
high-temperature regimes with variable laminar viscosity and density. A robust
numerical algorithm is proposed for implementation of Robin-type
wall-functions. Preliminary test results made for a channel flow showed good
accuracy and a weak dependence of the solution on the location of the
intermediate boundary where the boundary conditions are set.


title: Multivariate Analysis from a Statistical Point of View

abstract:
  Multivariate Analysis is an increasingly common tool in experimental high
energy physics; however, many of the common approaches were borrowed from other
fields. We clarify what the goal of a multivariate algorithm should be for the
search for a new particle and compare different approaches. We also translate
the Neyman-Pearson theory into the language of statistical learning theory.


title: Optimizing omnidirectional reflection by multilayer mirrors

abstract:
  Periodic layered media can reflect strongly for all incident angles and
polarizations in a given frequency range. Quarter-wave stacks at normal
incidence are commonplace in the design of such omnidirectional reflectors. We
discuss alternative design criteria to optimize these systems.


title: Note on the typhoon eye trajectory

abstract:
  We consider a model of typhoon based on the three-dimensional baroclinic
compressible equations of atmosphere dynamics averaged over hight and describe
a qualitative behavior of the vortex and possible trajectories of the typhoon
eye.


title: Special Attention Network

abstract:
  In this Note a social network model for opinion formation is proposed in
which a person connected to $q$ partners pays an {\em attention} $1/q$ to each
partner. The mutual attention between two connected persons $i$ and $j$ is
taken equal to the geometric mean $1/\sqrt{q_iq_j}$. Opinion is represented as
usual by an Ising spin $s=\pm 1$ and mutual attention is given through a
two-spin coupling $J_{ij} = J Q/\sqrt{q_iq_j}$, $Q$ being the average
connectivity in the network. Connectivity diminishes attention and only persons
with low connectivity can pay special attention to each other leading to a
durable common (or opposing) opinion. The model is solved in "mean-field"
approximation and a critical "temperature" $T_c$ proportional to $JQ$ is found,
which is independent of the number of persons $N$, for large $N$.


title:
Photoluminescence properties of forsterite (Mg2SiO4) nanobelts
  synthesized from Mg and SiO2 powders

abstract:
  Ternary oxide forsterite Mg2SiO4 single-crystalline nanobelts have been
synthesized at high yields via SiO2 assistant-oxide through a VS process. The
PL properties of the forsterite Mg2SiO4 nanobelts were observed. The emission
peak at 625 nm is attributed to the 4T1 - 6A1 transition of the trace Mn2+
ions. The other emission peak at 400nm may be due to the defects.


title: Monte Carlo simulation of granular fluids

abstract:
  An overview of recent work on Monte Carlo simulations of a granular binary
mixture is presented. The results are obtained numerically solving the Enskog
equation for inelastic hard-spheres by means of an extension of the well-known
direct Monte Carlo simulation (DSMC) method. The homogeneous cooling state and
the stationary state reached using the Gaussian thermostat are considered. The
temperature ratio, the fourth velocity moments and the velocity distribution
functions are obtained for both cases. The shear viscosity characterizing the
momentum transport in the thermostatted case is calculated as well. The
simulation results are compared with analytical predictions showing an
excellent agreement.


title: Information Transfer and Landauer's Principle

abstract:
  In this paper we present an analysis of information transfer based on
Landauer's principle (i.e. erasure of information is associated with an
increase in entropy), as well as considerations of analyticity and causality.
We demonstrate that holomorphic functions allowing complete analytic
continuation cannot propagate any information, such that information transfer
only occurs with analytic functions having points of non-analyticity (i.e.
meromorphic functions). Such points of non-analyticity (or discontinuities) are
incompatible with adiabaticity, so that information transfer must always be
accompanied by a change in entropy: a dynamic reformulation of Landauer's
Principle. In addition, since Brillouin proved that discontinuities cannot
travel faster than the speed of light c, this also implies that information
cannot be transferred at superluminal speeds.


title: Additive Entropies of degree-q and the Tsallis Entropy

abstract:
  The Tsallis entropy is shown to be an additive entropy of degree-q that
information scientists have been using for almost forty years. Neither is it a
unique solution to the nonadditive functional equation from which random
entropies are derived. Notions of additivity, extensivity and homogeneity are
clarified. The relation between mean code lengths in coding theory and various
expressions for average entropies is discussed.


title:
Direct reconstruction of the effective atomic number of materials by the
  method of multi-energy radiography

abstract:
  A direct method is proposed for reconstruction of the effective atomic number
by means of multi-energy radiography of the material. The accuracy of the
method is up to 95% . Advantages over conventional radiographic methods, which
ensure accuracy of just about 50%, are discussed. A physical model has been
constructed, and general expressions have been obtained for description of the
effective atomic number in a two-energy monitoring scheme. A universal
dependence has been predicted for the effective atomic number as a function of
relative (two-energy) radiographic reflex. The established theoretical law is
confirmed by the experimental data presented. The proposed development can find
multiple applications in non-destructive testing and related fields, including
those in the civil sphere as well as anti-terrorist activities.


title:
Two-surface wave decay: improved analytical theory and effects on
  electron acceleration

abstract:
  Two-surface wave decay (TSWD), i.e. the parametric excitation of electron
surface waves, was recently proposed as an absorption mechanism in the
interaction of ultrashort, intense laser pulses with solid targets. We present
an extension of the fluid theory of TSWD to a warm plasma which treats boundary
effects consistently. We also present test-particle simulations showing
localized enhancement of electron acceleration by TSWD fields; this effect
leads to a modulation of the current density entering into the target and may
seed current filamentation instabilities.


title: Nonsequential double ionization with few-cycle laser pulses

abstract:
  We investigate differential electron distributions in nonsequential double
ionization (NSDI) with linearly polarized, few-cycle pulses, using a classical
model based on a laser-assisted inelastic $(e^-,2e^-)$ rescattering mechanism.
We show that these yields, as functions of the momentum components parallel to
the laser polarization, are highly asymmetric, and strongly influenced by the
absolute phase, i.e., the phase difference between the carrier oscillation of a
few-cycle laser pulse and its envelope. Indeed, around a critical phase, such
distributions change their sign in a radical fashion. This phase dependence
provides a possibility for absoute-phase measurements which is, in principle,
superior to the schemes involving high-order harmonic generation or
above-threshold ionization.


title: Multiplet Structure of Feshbach Resonances in non-zero partial waves

abstract:
  We report a unique feature of magnetic field Feshbach resonances in which
atoms collide with non-zero orbital angular momentum. P-wave ($l=1$) Feshbach
resonances are split into two components depending on the magnitude of the
resonant state's projection of orbital angular momentum onto the field axis.
This splitting is due to the magnetic dipole-dipole interaction between the
atoms and it offers a means to tune anisotropic interactions of an ultra-cold
gas of atoms. A parameterization of the resonance in terms of an effective
range expansion is given.


title:
Energy loss of pions and electrons of 1 to 6 GeV/c in drift chambers
  operated with Xe,CO2(15%)

abstract:
  We present measurements of the energy loss of pions and electrons in drift
chambers operated with a Xe,CO2(15%) mixture. The measurements are carried out
for particle momenta from 1 to 6 GeV/c using prototype drift chambers for the
ALICE TRD. Microscopic calculations are performed using input parameters
calculated with GEANT3. These calculations reproduce well the measured average
and most probable values for pions, but a higher Fermi plateau is required in
order to reproduce our electron data. The widths of the measured distributions
are smaller for data compared to the calculations. The electron/pion
identification performance using the energy loss is also presented.


title: Small rare gas clusters in soft X-ray pulses

abstract:
  We develop a microscopic model for the interaction of small rare gas clusters
with soft X-ray radiation. It is shown that, while the overall charging of the
clusters is rather low, unexpectedly high atomic charge states can arise due to
charge imbalances inside the cluster. The mechanism does not require unusually
high absorption rates, and the heating can be described by standard inverse
bremsstrahlung formulae.


title: GEM Operation in Negative Ion Drift Gas Mixtures

abstract:
  The first operation of GEM gas gain elements in negative ion gas mixtures is
reported. Gains up to several thousand were obtained from single-stage GEMs in
carbon disulfide vapor at low pressure, and in mixtures of carbon disulfide
with Argon and Helium, some near 1 bar total pressure.


title:
Response of Autonomic Nervous System to Body Positions: Fourier and
  Wavelet Analysis

abstract:
  Two mathematical methods, the Fourier and wavelet transforms, were used to
study the short term cardiovascular control system. Time series, picked from
electrocardiogram and arterial blood pressure lasting 6 minutes, were analyzed
in supine position (SUP), during the first (HD1), and the second parts (HD2) of
$90^{\circ}$ head down tilt and during recovery (REC). The wavelet transform
was performed using the Haar function of period $T=2^j$ ($% j=1$,2,$... $,6) to
obtain wavelet coefficients. Power spectra components were analyzed within
three bands, VLF (0.003-0.04), LF (0.04-0.15) and HF (0.15-0.4) with the
frequency unit cycle/interval. Wavelet transform demonstrated a higher
discrimination among all analyzed periods than the Fourier transform. For the
Fourier analysis, the LF of R-R intervals and VLF of systolic blood pressure
show more evident difference for different body positions. For the wavelet
analysis, the systolic blood pressures show much more evident difference than
the R-R intervals. This study suggests a difference in the response of the
vessels and the heart to different body positions. The partial dissociation
between VLF and LF results is a physiologically relevant finding of this work.


title: Analyzing shell structure from Babylonian and modern times

abstract:
  We investigate ``shell structure'' from Babylonian times: periodicities and
beats in computer-simulated lunar data corresponding to those observed by
Babylonian scribes some 2500 years ago. We discuss the mathematical similarity
between the Babylonians' recently reconstructed method of determining one of
the periods of the moon with modern Fourier analysis and the interpretation of
shell structure in finite fermion systems (nuclei, metal clusters, quantum
dots) in terms of classical closed or periodic orbits.


title:
Energy-Calibration of the ATLAS Hadronic and Electromagnetic
  Liquid-Argon Endcap Calorimeters

abstract:
  In 2002 the first combined beam test of the hadronic and electromagnetic
liquid-argon endcap calorimeters of the ATLAS experiment took place at the SPS
test beam at CERN. A total of 15 million events from electrons, muons and pions
in the energy range from 6 to 200 GeV were recorded. The entire calibration
chain, from digital filter weights, over calibration constants, to clustering
and energy weights, as is relevant for the energy calibration of hadronic and
electromagnetic showers in ATLAS was tested and applied to the beam test data.
The calibration methods and first results for the combined performance of the
two calorimeters are presented.


title: On the Hylleraas Coordinates

abstract:
  The Hylleraas coordinates $s=r_{1}+r_{2}$, $t=r_{1}-r_{2}$, $u=|{\bf
r}_{1}-{\bf r}_{2}|$ are the natural coordinates for the determination of
properties of the Helium atom, the positive ions of its isoelectronic sequence,
and the negative Hydrogen ion. In this paper, we derive a new expression for
integrals representing properties such as the energy, normalization and
expectation of arbitrary operators, as written in the $(s,t,u)$ coordinates.
The expression derived is valid for both \emph{finite} and \emph{infinite}
space. The integrals for the various properties are comprised in each case of
two components $A$ and $B$. The contribution of these components to the volume
of integration and the normalization of a wave function for finite space, and
in variational calculations of the ground state energy of the Helium atom
confined in a finite volume is demonstrated by example. We prove that when the
integration space is \emph{infinite}, the expression for the energy and other
properties employed by Hylleraas corresponds \emph{only} to that of integral
$A$. We further prove that for the approximate variational wave functions
employed by Hylleraas and other authors, the contribution of the term $B$
vanishes. This contribution also vanishes for the exact wave function. It is
interesting to note that the component $B$ to the integral is not mentioned in
the literature. A principle purpose of the paper, therefore, is to point out
the existence of this term.


title: The Ideal Electromechanical Oscillator System

abstract:
  Oscillators and rotators are among the most important physical systems. For
centuries the only known rotating systems that actually reached the limits of
the ideal situation of undamped periodical motion were the planets in their
orbits. Physics had to develop quantum mechanics to discover new systems that
actually behaved like ideal, undamped, oscillators or rotators. However, all
examples of this latter systems occur in atomic or molecular scale. The
objective of the present letter is to show how the limit of ideal oscillating
motion can be challenged by a man-made system. We demonstrate how a simple
model electromechanical system consisting of a superconducting coil and a
magnet can be made to display both mechanical and electrical undamped
oscillations for certain experimental conditions. The effect might readily be
attainable with the existing materials technologies and we discuss the
conditions to circumvent energy losses. The result is a lossless system that
might generate hundreds of Ampere of rectified electrical current by means of
the periodical conversion between gravitational potential, kinetic, and
magnetic energies.


title:
Simulation of cellular irradiation with the CENBG microbeam line using
  GEANT4

abstract:
  Light-ion microbeams provide a unique opportunity to irradiate biological
samples at the cellular level and to investigate radiobiological effects at low
doses of high LET ionising radiation. Since 1998 a single-ion irradiation
facility has been developed on the focused horizontal microbeam line of the
CENBG 3.5 MV Van de Graaff accelerator. This setup delivers in air single
protons and alpha particles of a few MeV onto cultured cells, with a spatial
resolution of a few microns, allowing subcellular targeting. In this paper, we
present results from the use of the GEANT4 toolkit to simulate cellular
irradiation with the CENBG microbeam line, from the entrance to the microprobe
up to the cellular medium.


title: Hybrid atomistic-continuum methods for multiscale hydrodynamics

abstract:
  We discuss hybrid atomistic-continuum methods for multiscale hydrodynamic
applications. Both dense fluid and dilute gas formulations are considered. The
choice of coupling method and its relation to the fluid physics is discussed.
The differences in hybrid methods resulting from underlying compressible and
incompressible continuum formulations as well as the importance of timescale
decoupling are highlighted. We also discuss recently developed compressible and
incompressible hybrid methods for dilute gases. The incompressible framework is
based on the Schwarz alternating method whereas the compressible method is a
multi-species, fully adaptive mesh and algorithm refinement approach which
introduces the direct simulation Monte Carlo at the finest level of mesh
refinement.


title:
Problems When Studying Holography (Probleme beim Erlernen der
  Holographie)

abstract:
  Holography as a subject is neglected largely in current physics lessons and
in school books. Even though this topic might be complex, it is applicable and
viable in the world that we live in. Holography lends itself to further develop
knowledge with regard to inference optics. However, misconceptions of students
impede the learning process. Research conducted by our research group shows
that problematic perceptions regarding interference optics still exist with
physics students at the intermediate level and on occasion are even sustained
by illustrations in school books. Based on this analysis, a concept for a
series of lessons is introduced. This series can be taught in physics lessons
at the secondary school level II and in basic courses. Initial results from
dealing with the subject of holography in an advanced training course will be
presented.


title:
Misconceptions regarding the cancellation of self-forces in the
  transverse equation of motion for an electron in a bunch

abstract:
  As a consequence of motions driven by external forces, self-fields originate
within an electron bunch, which are different from the static case. In the case
of magnetic external forces acting on an ultrarelativistic beam, the
longitudinal self-interactions are responsible for CSR (Coherent Synchrotron
Radiation)-related phenomena, which have been studied extensively. On the other
hand, transverse self-interactions are present too. At the time being, several
existing theoretical analysis of transverse dynamics rely on the so-called
cancellation effect, which has been around for more than ten years. In this
paper we explain why in our view such an effect is not of practical nor of
theoretical importance.


title: The New Paradigm for Gamma Ray Bursts: a Case of Unethical Behaviour?

abstract:
  One might have hoped that the immediacy and completeness of scientific
information provided through the internet would have made the wrongful
appropriation of someone else's ideas --now so easy to detect and document-- a
sin of the past. Not so. Here I present evidence, which the reader should
judge, of such an apparent misconduct by Sir Martin Rees, the British
Astronomer Royal, and others. Unethical behaviour is not unknown in science. My
sole intention is to call attention to the problem by way of example, in an
attempt to contribute to a more ethical atmosphere, which would in my opinion
be beneficial to the field.


title: Synthetic Turbulence, Fractal Interpolation and Large-Eddy Simulation

abstract:
  Fractal Interpolation has been proposed in the literature as an efficient way
to construct closure models for the numerical solution of coarse-grained
Navier-Stokes equations. It is based on synthetically generating a
scale-invariant subgrid-scale field and analytically evaluating its effects on
large resolved scales. In this paper, we propose an extension of previous work
by developing a multiaffine fractal interpolation scheme and demonstrate that
it preserves not only the fractal dimension but also the higher-order structure
functions and the non-Gaussian probability density function of the velocity
increments. Extensive a-priori analyses of atmospheric boundary layer
measurements further reveal that this Multiaffine closure model has the
potential for satisfactory performance in large-eddy simulations. The
pertinence of this newly proposed methodology in the case of passive scalars is
also discussed.


title: Flashing motor at high transition rate

abstract:
  The movement of a Brownian particle in a fluctuating two-state periodic
potential is investigated. At high transition rate, we use a perturbation
method to obtain the analytical solution of the model. It is found that the net
current is a peaked function of thermal noise, barrier height and the
fluctuation ratio between the two states. The thermal noise may facilitate the
directed motion at a finite intensity. The asymmetry parameter of the potential
is sensitive to the direction of the net current.


title:
On image reconstruction with the two-dimensional interpolating resistive
  readout structure of the Virtual-Pixel detector

abstract:
  The two-dimensional interpolating readout concept of the Virtual-Pixel
detector (ViP detector) goes along with an enormous reduction of electronic
channels compared to pure pixel devices. However, the special concept of the
readout structure demands for adequate position reconstruction methods.
Theoretical considerations reflecting the choice and the combination of linear
algorithms with emphasis on correct position reconstruction and spatial
resolution are presented. A subsequent two-dimensional coordinate
transformation further improves the image response of the system. Measured
images show how far the theoretical predictions of the simulations can be
verified and to what extent they can be used to improve the position
reconstruction.


title: A geometric sequence of neutral vector boson and charged lepton masses

abstract:
  The neutral vector meson resonances, phi, J/psi, Bs* and Upsilon, and the tau
lepton occupy consecutive mass levels in a geometric series which also includes
the muon and the neutral vector boson, Z, in a symmetric arrangement. The mass
of the tau lepton is equal to the geometric mean of the phi and J/psi masses.


title:
Development of a two-dimensional virtual pixel X-ray imaging detector
  for time-resolved structure research

abstract:
  An interpolating two-dimensional X-ray imaging detector based on a single
photon counter with gas amplification by GEM (gas electron multiplier)
structures is presented. The detector system can be used for time-resolved
structure research down to the microsecond-time domain. The prototype detector
has been tested at the SAXS beamline at ELETTRA synchrotron light source with a
beam energy of 8 keV to test its capabilities in the rough beamline
environment. The imaging performance is examined with apertures and standard
diffraction targets. Finally, the application in a time-resolved lipid
temperature jump experiment is presented.


title: Steppingstones in Hamiltonian dynamics

abstract:
  Easy steps through essential Hamiltonian dynamics are outlined, from
necessary definitions of Poisson brackets and canonical transformations, to a
quick proof that Hamiltonian evolution is made by canonical transformations,
the quickest proof of Liouville's theorem, and on to Poincare-Cartan integral
invariants and completely integrable dynamics, making room, providing tools,
and setting the stage for more recent developments.


title:
Finite-field evaluation of the Lennard-Jones atom-wall interaction
  constant C_3 for alkali-metal atoms

abstract:
  A finite-field scaling method is applied to evaluate the Lennard-Jones
interaction constant C_3 for alkali-metal atoms. The calculations are based on
the relativistic single-double (SD) approximation in which single and double
excitations of Dirac-Hartree-Fock wave functions are included to all orders in
perturbation theory.


title:
Complete homochirality induced by the nonlinear autocatalysis and
  recycling

abstract:
  A nonlinear autocatalysis of a chiral substance is shown to achieve
homochirality in a closed system, if the back-reaction is included. Asymmetry
in the concentration of two enantiomers or the enantiometric excess increases
due to the nonlinear autocatalysis. Furthermore, when the back-reaction is
taken into account, the reactant supplied by the decomposition of the
enantiomers is recycled to produce more and more the dominant one, and
eventually the homochirality is established.

categories: physics.chem-ph astro-ph physics.bio-ph q-bio.PE


title:
Quantum Mechanical Cumulant Dynamics near Stable Periodic Orbits in
  Phase Space: Application to the classical-like dynamics of quantum
  accelerator modes

abstract:
  We formulate a general method for the study of semiclassical-like dynamics in
stable regions of a mixed phase-space, in order to theoretically study the
dynamics of quantum accelerator modes. In the simplest case, this involves
determining solutions, which are stable when constrained to remain pure-state
Gaussian wavepackets, and then propagating them using a cumulant-based
formalism. Using this methodology, we study the relative longevity, under
different parameter regimes, of quantum accelerator modes. Within this
attractively simple formalism, we are able to obtain good qualitative agreement
with exact wavefunction dynamics.


title:
Structure and stability of copper clusters : A tight-binding molecular
  dynamics study

abstract:
  In this paper we propose a tight-binding molecular dynamics with parameters
fitted to first-principles calculations on the smaller clusters and with an
environment correction, to be a powerful technique for studying large
transition/noble metal clusters. In particular, the structure and stability of
$Cu_n$ clusters for $n=3-55$ are studied by using this technique. The results
for small $Cu_n$ clusters ($n=3-9$) show good agreement with {\it ab initio}
calculations and available experimental results. In the size range $10\le n \le
55$ most of the clusters adopt icosahedral structure which can be derived from
the 13-atom icosahedron, the polyicosahedral 19-, 23-, and 26-atom clusters and
the 55-atom icosahedron, by adding or removing atoms. However, a local
geometrical change from icosahedral to decahedral structure is observed for $n
= 40-44$ and return to the icosahedral growth pattern is found at $n=45$ which
continues. Electronic "magic numbers" ($n=2$, 8, 20, 34, 40) in this regime are
correctly reproduced. Due to electron pairing in HOMOs, even-odd alternation is
found. A sudden loss of even-odd alternation in second difference of cluster
binding energy, HOMO-LUMO gap energy and ionization potential is observed in
the region $n\sim40$ due to structural change there. Interplay between
electronic and geometrical structure is found.


title: Event Selection Using an Extended Fisher Discriminant Method

abstract:
  This note discusses the problem of choosing between hypotheses in a situation
with many, correlated non-normal variables. A new method is introduced to
shrink the many variables into a smaller subset of variables with zero mean,
unit variance, and zero correlation coefficient between variables. These new
variables are well suited to use in a neural net.


title:
In-silico folding of a three helix protein and characterization of its
  free-energy landscape in an all-atom forcefield

abstract:
  We report the reproducible first-principles folding of the 40 amino acid,
three-helix headpiece of the HIV accessory protein in a recently developed
all-atom free-energy forcefield. Six of twenty simulations using an adapted
basin-hopping method converged to better than 3 \AA backbone RMS deviation to
the experimental structure. Using over 60,000 low-energy conformations of this
protein, we constructed a decoy tree that completely characterizes its folding
funnel.


title:
Propagation of a mutually incoherent optical vortex pair in anisotropic
  nonlinear media

abstract:
  We study propagation of a pair of oppositely charged and mutually incoherent
vortices in anisotropic nonlinear optical media. Mutual interactions retard the
delocalization of the vortex core observed for isolated vortices.


title: Random Walker Ranking for NCAA Division I-A Football

abstract:
  Each December, college football fans and pundits across America debate which
two teams should meet in the NCAA Division I-A National Championship game. The
Bowl Championship Series (BCS) standings employed to select the teams invited
to this game are intended to provide an unequivocal #1 v. #2 game for the
championship; however, this selection process has itself been highly
controversial in recent years. The computer algorithms that constitute one part
of the BCS standings often act as lightning rods for the controversy, in part
because they are inadequately explained to the public. We present an
alternative algorithm that is simply explained yet remains effective at ranking
the best teams. We define a ranking in terms of biased random walkers on the
graph formed by the schedule of games played, with two teams (vertices)
connected by an edge if they played each other. Each random walker moves from
team to team by selecting a game and "voting" for its winner with probability
p, tracing out a never-ending path motivated by the "my team beat your team"
argument. We study the statistical properties of a collection of such walkers,
relate the rankings to the community structure of the underlying network, and
demonstrate the results for recent NCAA Division I-A seasons. We also discuss
the algorithm's asymptotic behavior, illustrated with some analytically
tractable cases for round-robin tournaments, and discuss possible
generalizations.


title:
Modeling of realistic cladding structures for air-core photonic band-gap
  fibers

abstract:
  Cladding structures of photonic band-gap fibers often have air-holes of
non-circular shape and, typically, close-to-hexagonal air holes with curved
corners are observed. We study photonic band-gaps in such structures by aid of
a two-parameter representation of the size and curvature. For the fundamental
band-gap we find that the band-gap edges (the intersections with the air line)
shift toward shorter wavelengths when the air-filling fraction f is increased.
The band-gap also broadens and the relative band-width increases exponentially
with f^2. Comparing to recent experiments [Nature 424, 657 (2003)] we find very
good agreement.


title: Dosimetry for radiocolloid therapy of cystic craniopharyngiomas

abstract:
  The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is
investigated. Analytical calculations based on the Loevinger and the Berger
formulae for electrons and photons, respectively, are compared with Monte Carlo
simulations. The role of the material of which the colloid introduced inside
the craniopharyngioma is made of as well as that forming the cyst wall is
analyzed. It is found that the analytical approaches provide a very good
description of the simulated data in the conditions where they can be applied
(i.e., in the case of a uniform and infinite homogeneous medium). However, the
consideration of the different materials and interfaces produces a strong
reduction of the dose delivered to the cyst wall in relation to that predicted
by the Loevinger and the Berger formulae.


title:
EIT Reconstruction Algorithms: Pitfalls, Challenges and Recent
  Developments

abstract:
  We review developments, issues and challenges in Electrical Impedance
Tomography (EIT), for the 4th Workshop on Biomedical Applications of EIT,
Manchester 2003. We focus on the necessity for three dimensional data
collection and reconstruction, efficient solution of the forward problem and
present and future reconstruction algorithms. We also suggest common pitfalls
or ``inverse crimes'' to avoid.


title: The 2S-2P Lamb Shift in He+

abstract:
  The current theoretical status of the Lamb shift in He+ is discussed. Recent
calculations of two-loop binding corrections to the Lamb shift significantly
shift the theoretical value of the "classic" Lamb shift in He+, i.e. of the
2S_1/2-2P_1/2-interval. In this brief research note, we present a new
(theoretical) value for this interval which reads 14041.474(42) Mhz. The
theoretical uncertainty is reduced as well as the discrepancy between theory
and experiment. Planned measurements should be of help in further elucidating
the situation.


title: Primary population of antiprotonic helium states

abstract:
  A full quantum mechanical calculation of partial cross-sections leading to
different final states of antiprotonic helium atom was performed. Calculations
were carried out for a wide range of antiprotonic helium states and incident
(lab) energies of the antiproton.


title: A thought experiment on consciousness

abstract:
  The Mind-Body Problem, which constitutes the starting point for a large part
of the speculations about consciousness and conscious experience, can be
re-stated in an equivalent way, using the `brain duplication' argument
described in this paper. If we assume that consciousness follows from a
peculiar organization of physical matter and energy, namely that it does not
transcend physical reality, then the brain duplication argument gives a
possible interesting physical characterization of the mind: namely, a sort of
extensive interdependence of the brain with the whole surrounding physical
world in giving rise to consciousness.


title: The CDF Calorimetry Upgrade for Run IIb

abstract:
  The physics program at the Fermilab Tevatron Collider will continue to
explore the high energy frontier of particle physics until the commissioning of
the LHC at CERN. The luminosity increase provided by the Main Injector will
require upgrades beyond those implemented for the first stage (Run IIa) of the
Tevatron's Run II physics program. The upgrade of the CDF calorimetry includes:
1) the replacement of the slow gas detectors on the front face of the Central
Calorimeter with a faster scintillator version which has a better segmentation,
and 2) the addition of timing information to both the Central and EndPlug
Electromagnetic Calorimeters to filter out cosmic ray and beam related
backgrounds.


title: The CDF MiniPlug Calorimeters at the Tevatron

abstract:
  Two MiniPlug calorimeters, designed to measure the energy and lateral
position of particles in the pseudorapidity region of 3.6<|eta|<5.1 of the CDF
detector, have been installed as part of the Run II CDF upgrade at the Tevatron
collider. Detector performance and first results from $\bar pp$ collision data
are presented.


title: Large phenotype jumps in biomolecular evolution

abstract:
  By defining the phenotype of a biopolymer by its active three-dimensional
shape, and its genotype by its primary sequence, we propose a model that
predicts and characterizes the statistical distribution of a population of
biopolymers with a specific phenotype, that originated from a given genotypic
sequence by a single mutational event. Depending on the ratio g0 that
characterizes the spread of potential energies of the mutated population with
respect to temperature, three different statistical regimes have been
identified. We suggest that biopolymers found in nature are in a critical
regime with g0 in the range 1-6, corresponding to a broad, but not too broad,
phenotypic distribution resembling a truncated Levy flight. Thus the biopolymer
phenotype can be considerably modified in just a few mutations. The proposed
model is in good agreement with the experimental distribution of activities
determined for a population of single mutants of a group I ribozyme.

categories: physics.bio-ph cond-mat.soft physics.data-an q-bio.PE


title:
Inner Shell Definition and Absolute Hydration Free Energy of K+(aq) on
  the Basis of Quasi-chemical Theory and Ab Initio Molecular Dynamics

abstract:
  K+(aq) ion is an integral component of many cellular processes, amongst which
the most important, perhaps, is its role in transmitting electrical impulses
along the nerve. Understanding its hydration structure and thermodynamics is
crucial in dissecting its role in such processes. Her we address these
questions using both the statistical mechanical quasi-chemical theory of
solutions and ab initio molecular dynamics simulations. Simulations predict an
interesting hydration structure for K+(aq): the population of about six (6)
water molecules within the initial minimum of the observed g_{KO}(r) at
infinite dilution involves four (4) inner-most molecules that the
quasi-chemical theory suggests should be taken as the theoretical inner shell.
The contribution of the 5th and 6th closest water molecules is observable as a
distinct shoulder on the principal maximum of the g_{KO}(r). The quasi-chemical
estimate of solvation free energy for the neutral pair KOH is also in good
agreement with experiments.


title: Stochastic analysis of surface roughness

abstract:
  For the characterization of surface height profiles we present a new
stochastic approach which is based on the theory of Markov processes. With this
analysis we achieve a characterization of the complexity of the surface
roughness by means of a Fokker-Planck or Langevin equation, providing the
complete stochastic information of multiscale joint probabilities. The method
was applied to different road surface profiles which were measured with high
resolution. Evidence of Markov properties is shown. Estimations for the
parameters of the Fokker-Planck equation are based on pure, parameter free data
analysis.


title: A design outline for a Cherenkoff neutrino observatory

abstract:
  An economical procedure to upgrade the existing Fairport water Cherenkoff
detector is described. The detector will lower its energy threshold by
increased photocoverage and light yield. Furthermore, by addition of a Gd salt
it will become sensitive to neutrons produced by the inverse beta decay of
anti-neutrinos on protons. The new detector can then take advantage of the
existence of the Perry power nuclear reactor, located 12.9km away, as a large
source of anti-neutrinos. The present gap in the exclusion plot of the neutrino
oscillation parameters ($\Delta m^2$ from $2\times 10^{-4}$ to $10^{-2} eV^2$)
may be explored and closed within 12-18 months of run-time. The detector will
be able to observe other types of neutrino sources (Boron-8 solar, atmospheric,
and supernova) with unprecedented advantages. The low threshold also will allow
searching for exotic modes of proton-decay.


title: Science as a Culture - Its Implications

abstract:
  This is a lecture on the ethics and role of science in promoting rational and
objective thinking in society. It was delivered by Prof. Shyamal Sengupta of
Kolkata, India. Prof. Sengupta, who passed away recently, has inspired
generations of Indian physicists by his rational viewpoints on science and by
teaching his students the importance of a scientific outlook. We, some of his
former students dedicate this small corner of the archive to his fond memory.


title: Attractive Potential around a Thermionically Emitting Microparticle

abstract:
  We present a simulation study of the charging of a dust grain immersed in a
plasma, considering the effect of electron emission from the grain (thermionic
effect). It is shown that the OML theory is no longer reliable when electron
emission becomes large: screening can no longer be treated within the
Debye-Huckel approach and an attractive potential well forms, leading to the
possibility of attractive forces on other grains with the same polarity. We
suggest to perform laboratory experiments where emitting dust grains could be
used to create non-conventional dust crystals or macro-molecules.


title: Spinning eggs--which end will rise?

abstract:
  We examine the spinning behavior of egg-shaped axisymmetric bodies whose
cross sections are described by several oval curves similar to real eggs with
thin and fat ends. We use the gyroscopic balance condition of Moffatt and
Shimomura and analyze the slip velocity of the bodies at the point of contact
as a function of $\theta$, the angle between the axis of symmetry and the
vertical axis, and find the existence of the critical angle $\theta_c$. When
the bodies are spun with an initial angle $\theta_{\rm initial}>\theta_c$,
$\theta$ will increase to $\pi$, implying that the body will spin at the thin
end. Alternatively, if $\theta_{\rm initial}<\theta_c$, then $\theta$ will
decrease. For some oval curves, $\theta$ will reduce to 0 and the corresponding
bodies will spin at the fat end. For other oval curves, a fixed point at
$\theta_f$ is predicted, where $0 <\theta_f< \theta_c$. Then the bodies will
spin not at the fat end, but at a new stable point with $\theta_f$. The
empirical fact that eggs more often spin at the fat than at the thin end is
explained.


title: Universality in snowflake aggregation

abstract:
  Aggregation of ice crystals is a key process governing precipitation.
Individual ice crystals exhibit considerable diversity of shape, and a wide
range of physical processes could influence their aggregation; despite this we
show that a simple computer model captures key features of aggregate shape and
size distribution reported recently from Cirrus clouds. The results prompt a
new way to plot the experimental size distributions leading to remarkably good
dynamical scaling. That scaling independently confirms that there is a single
dominant aggregation mechanism at play, albeit our model (based on undeflected
trajectories to contact) does not capture its form exactly.


title:
The Psychopathological Fabric of Time (and Space) and Its Underpinning
  Pencil-Borne Geometries

abstract:
  The paper presents, to our knowledge, a first fairly comprehensive and
mathematically well-underpinned classification of the psychopathology of time
(and space). After reviewing the most illustrative first-person accounts of
"anomalous/peculiar" experiences of time (and, to a lesser degree, also space)
we introduce and describe in detail their algebraic geometrical model. The
model features six qualitatively different types of the internal structure of
time dimension and four types of that of space. As for time, the most
pronounced are the ordinary "past-present-future," "present-only"
("eternal/everlasting now") and "no-present" (time "standing still") patterns;
the remaining types represent an intriguing superposition of the three.
Concerning space, the most elementary are the ordinary, i.e. "here-and-there,"
mode and the "here-only" one ("omnipresence"); the remaining two cases are
again a specific mixture of the former two. We then show what the admissible
combinations of temporal and spatial psycho-patterns are and give a rigorous
algebraic geometrical classification of them. The paper ends with a brief
account of important epistemological/ontological questions stemming from the
approach.


title: Small rare gas clusters in XUV laser pulses

abstract:
  Semi-classical molecular dynamics simulations of small rare gas clusters in
short laser pulses of 100 nm wavelength were performed. For comparison, the
cluster response to 800 nm laser pulses was investigated as well. The inner
ionization dynamics of the multi-electron atoms inside the cluster was treated
explicitly. The simulation results underpin that at XUV wavelengths collisions
play an important role in the energy absorption. The generation of the
surprisingly high charge states of Xe atoms inside clusters, as they were
observed in the free-electron laser experiment at DESY, Hamburg, Germany
[Wabnitz et al., Nature 420, 482 (2002)], is due to the reduced ionization
potential of atoms inside charged clusters, the ionization ignition mechanism,
and collisions.


title: Pitfalls of Goodness-of-Fit from Likelihood

abstract:
  The value of the likelihood is occasionally used by high energy physicists as
a statistic to measure goodness-of-fit in unbinned maximum likelihood fits.
Simple examples are presented that illustrate why this (seemingly intuitive)
method fails in practice to achieve the desired goal.


title: The shell model approach to the rotating turbulence

abstract:
  Applications of the shell model of turbulence to the case of rapidly rotating
bodies are considered. Starting from the classical GOY model we introduce the
Coriolis force and obtain a $\sim k^{-2}$ spectrum for 3D hydrodynamical
turbulence for the free decay regime as well for the regime with external
forcing. Additional modifications of the GOY model providing a realistic form
of the helicity are proposed.


title: The connection between conformal group and quantum states of photons

abstract:
  This note is concerned with the connections between the conformal group and
the quantum states of photons. It is shown that there exist analogies between
the photonic quantum states and the conformal group, namely, the
time-development operator (with a free Hamiltonian), displacement and squeezing
operators of the vacuum state corresponds to the dilatation, translation,
proper Lorentz transformations, respectively, and that the three quantum states
of photons ({\it i.e.}, Fock state, coherent state and squeezed state) in
quantum optics thus bear some analogy to the above three transformations in the
conformal group. Based on this comparison, we argue by analogy that if the
phase transformation operators acting on a vacuum state (hence the Fock state,
coherent state and squeezed state are generated) are truly exactly analogous to
the conformal transformations, then a fourth quantum state of photons (referred
to as the {\it conformal state}), which corresponds to the {\it special
conformal} transformation (acceleration transformation) and will therefore be
of special physical interest, can be suggested.


title:
The self-induced charge current in the experiments detecting photon rest
  mass

abstract:
  This note considers two related topics regarding the {\it self-induced charge
current} in the experiments detecting photon rest mass: (i) the effective rest
mass, $(0.3\sim 1)\times 10^{-54}$ Kg, of photons arising from the ions in the
secondary cosmic ray is compared to Luo {\it et al.}'s new upper limit on
photon rest mass ($1.2\times 10^{-54}$ Kg); (ii) there are two main classes of
experiments to detect photon rest mass based respectively on the
Amp\`{e}re-Maxwell-Proca equation and the Lagrangian (or Hamiltonian) density
of electromagnetically interacting system.


title: 3-Dimensional Mapping of Corneal Topography and Thickness

abstract:
  Optical sections of the cornea are obtained by illumination with a collimated
beam expanded in a fan shape by a small rotary cylindrical lens. The light
diffused from the cornea is observed by two cameras and processed in order to
yield the surfaces' profiles. The optical system used to project a thin
rotating line on the cornea consists of a white light source provided with
optical fiber bundle output which is first conditioned by a set of lenses so
that it would produce a spot on the cornea. A small cylinder lens is used to
expand the beam in one direction so that a thin line illuminates the cornea,
rather than a spot. The cylinder lens is provided with motor driven rotation
about an axis normal to its own in order to rotate the line on the cornea such
that the projected line scans the whole cornea; the illuminator is completed
with a slit aperture. The cornea is not perfectly transparent, scattering some
of the light that traverses it; this fact is used for its observation by two
cameras. These are placed at pre-defined angles with the illumination axis, so
that optical sections of the cornea can be seen; the use of two cameras avoids
the need for camera rotation in synchronism with the cylinder. The two cameras'
images can be combined in order to simulate a single virtual rotating camera.
Image processing is used to extract information about the corneal surfaces
profiles and thickness from the optical sections. Several peculiar aspects of
processing are discussed, namely the corneal edge detection algorithm, the
correction for angle of view and deformation due to observation of the inner
surface through the cornea.


title:
New Vacuum State of the Electromagnetic Field-Matter Coupling System and
  the Physical Interpretation of Casimir Effect

abstract:
  A new concise method is presented for the calculation of the ground-state
energy of the electromagnetic field and matter field interacting system. With
the assumption of squeezed-like state, a new vacuum state is obtained for the
interacting system. The energy of the new vacuum state is lower than that given
by the second-order perturbation theory in existing theories. In our theory,
the Casimir effect is attributed neither to the quantum fluctuation in the
zero-point energy of the genuine electromagnetic field nor to that in the
zero-point energy of the genuine matter field, but to that in the vacuum state
of the interacting system. Both electromagnetic field and matter field are
responsible for the Casimir effect.


title:
Efficient input and output fiber coupling to a photonic crystal
  waveguide

abstract:
  The efficiency of evanescent coupling between a silica optical fiber taper
and a silicon photonic crystal waveguide is studied. A high reflectivity mirror
on the end of the photonic crystal waveguide is used to recollect, in the
backwards propagating fiber mode, the optical power that is initially coupled
into the photonic crystal waveguide. An outcoupled power in the backward
propagating fiber mode of 88% of the input power is measured, corresponding to
a lower bound on the coupler efficiency of 94%.


title:
Effects Of Aerosol And Multiple Scattering On The Polarization Of The
  Twilight Sky

abstract:
  The paper contains the review of a number of wide-angle polarization
CCD-measurements of the twilight sky in V and R color bands with effective
wavelengths equal to 550 and 700 nm. The basic factors effecting (usually
decreasing) on the polarization of the twilight sky are the atmospheric aerosol
scattering and multiple scattering. The method of multiple scattering
separation is being considered. The results are compared with the data of
numerical simulation of radiation transfer in the atmosphere for different
aerosol models. The whole twilight period is divided on the different stages
with different mechanisms forming the twilight sky polarization properties.


title:
Development of Photogrammetric Methods of Stress Analysis and Quality
  Control

abstract:
  A photogrammetric method of stress analysis has been developed to test thin,
nonstandard windows designed for hydrogen absorbers, major components of a muon
cooling channel. The purpose of the absorber window tests is to demonstrate an
understanding of the window behavior and strength as a function of applied
pressure. This is done by comparing the deformation of the window, measured via
photogrammetry, to the deformation predicted by finite element analysis (FEA).
FEA analyses indicate a strong sensitivity of strain to the window thickness.
Photogrammetric methods were chosen to measure the thickness of the window,
thus providing data that are more accurate to the FEA. This, plus improvements
made in hardware and testing procedures, resulted in a precision of 5 microns
in all dimensions and substantial agreement with FEA predictions.


title: Mass differences of SU(3) strange hadrons

abstract:
  Mass differences between octet strange baryons, octet and decuplet strange
baryons, and nonet vector mesons and octet baryons of equal strangeness
coincide (within the small experimental uncertainties) with the levels of a
recently proposed hadron mass spectrum. A number, M, characterises the mass
difference in relation to the strange quark mass of the spectrum. The mass
diference of Lambda and Sigma0 (delta I=1) is characterised by M=+1. The mass
difference of Sigma0 and Sigma(1385)0 (delta J=1) is characterised by M=-1.
Vector meson-baryon (delta J=1/2) mass differences are characterised by M=-1/2.
The mass differences of strange decuplet baryon resonances (delta S=1) are
characterised by M=-2 and M=-3, where M is equal to the strangeness of the more
massive baryon.


title:
Gallium transformation under femtosecond laser excitation: Phase
  coexistence and incomplete melting

abstract:
  The reversible phase transition induced by femtosecond laser excitation of
Gallium has been studied by measuring the dielectric function at 775 nm with ~
200 fs temporal resolution. The real and imaginary parts of the transient
dielectric function were calculated from absolute reflectivity of Gallium layer
measured at two different angles of incidence, using Fresnel formulas. The
time-dependent electron-phonon effective collision frequency, the heat
conduction coefficient and the volume fraction of a new phase were restored
directly from the experimental data, and the time and space dependent electron
and lattice temperatures in the layer undergoing phase transition were
reconstructed without ad hoc assumptions. We converted the temporal dependence
of the electron-phonon collision rate into the temperature dependence, and
demonstrated, for the first time, that the electron-phonon collision rate has a
non-linear character. This temperature dependence converges into the known
equilibrium function during the cooling stage. The maximum fraction of a new
phase in the laser-excited Gallium layer reached only 60% even when the
deposited energy was two times the equilibrium enthalpy of melting. We have
also demonstrated that the phase transition pace and a fraction of the
transformed material depended strongly on the thickness of the laser-excited
Gallium layer, which was of the order of several tens of nanometers for the
whole range of the pump laser fluencies up to the damage threshold. The
kinetics of the phase transformation after the laser excitation can be
understood on the basis of the classical theory of the first-order phase
transition while the duration of non-thermal stage appears to be comparable to
the sub-picosecond pulse length.


title: Classical Electrodynamics and Theory of Relativity

abstract:
  This book is a manual for the course of electrodynamics and theory of
relativity. It is recommended primarily for students of mathematical
departments. This defines its style: I use elements of vectorial and tensorial
analysis, differential geometry, and theory of distributions in it.
  Russian version of this book was published in 1997 under the approval by
Methodic Commission of Mathematical Department of Bashkir State University.


title: Transverse fluctuations of grafted polymers

abstract:
  We study the statistical mechanics of grafted polymers of arbitrary stiffness
in a two-dimensional embedding space with Monte Carlo simulations. The
probability distribution function of the free end is found to be highly
anisotropic and non-Gaussian for typical semiflexible polymers. The reduced
distribution in the transverse direction, a Gaussian in the stiff and flexible
limits, shows a double peak structure at intermediate stiffnesses. We also
explore the response to a transverse force applied at the polymer free end. We
identify F-Actin as an ideal benchmark for the effects discussed.


title:
Role of Wood anomalies in optical properties of thin metallic films with
  a bidimensional array of subwavelength holes

abstract:
  Recents works deal with the optical transmission on arrays of subwavelength
holes in a metallic layer deposited on a dielectric substrate. Making the
system as realistic as possible, we perform simulations to enlighten the
experimental data. This paper proposes an investigation of the optical
properties related to the transmission of such devices. Numerical simulations
give theoretical results in good agreement with experiment and we observe that
the transmission and reflection behaviour correspond to Fano's profile
correlated with resonant response of the eigen modes coupled with
nonhomogeneous diffraction orders. We thus conclude that the transmission
properties observed could conceivably be explained as resulting from resonant
Wood's anomalies.


title:
Light transmission assisted by Brewster-Zennek modes in chromium films
  carrying a subwavelength hole array

abstract:
  This work confirms that not only surface plasmons but many other kinds of
electromagnetic eigenmodes should be considered in explaining the values of the
transmittivity through a slab bearing a two-dimensional periodic corrugation.
Specifically, the role of Brewster-Zennek modes appearing in metallic films
exhibiting regions of weak positive dielectric constant. It is proposed that
these modes play a significant role in the light transmission in a thin
chromium film perforated with normal cylindrical holes, for appropriate lattice
parameters.


title:
Polarization effects in metallic films perforated with a bidimensional
  array of subwavelength rectangular holes

abstract:
  For several years, periodical arrays of subwavelength cylindrical holes in
thin metallic layers have taken a crucial importance in the context of the
results reported by Ebbesen et al, on particularly attractive optical
transmission experiments. It had been underlined that the zeroth order
transmission pattern does not depend on the polarization of the incident light
at normal incidence. In the present paper, we show that it is not the case for
rectangular holes, by contrast to the case of circular holes. In this context,
we suggest a new kind of polarizer that present the advantages brought by the
original Ebbesen devices. Assuming the recent technological interest for these
kinds of metallic gratings, such a kind of polarizer could lead to new
technological applications.


title: Low-energy unphysical saddle in polynomial molecular potentials

abstract:
  Vibrational spectra of polyatomic molecules are often obtained from a
polynomial expansion of the adiabatic potential around a minimum. For several
molecules, we show that such an approximation displays an unphysical saddle
point of comparatively small energy, leading to a region where the potential is
negative and unbounded. This poses an upper limit for a reliable evaluation of
vibrational levels. We argue that the presence of such saddle points is
general.


title:
Method of functional integration in the problem of line width of
  parametric X-ray relativistic electron radiation in a crystal

abstract:
  The coherent and non-coherent scattering effects on "backward" parametric
X-ray radiation by relativistic electrons in a crystal on the basis of the
method of functional integration is investigated. A comparison of contributions
of these effects to parametric X-ray radiation line width has been considered.
It is shown that in a number of cases the major contribution to the line width
of parametric X-ray radiation is made by non-coherent multiple scattering.


title:
Bandgap engineering and defect modes in photonic crystals with rotated
  hexagonal holes

abstract:
  We study the bandgap structure of two-dimensional photonic crystals created
by a triangular lattice of rotated hexagonal holes, and explore the effects of
the reduced symmetry in the unit-cell geometry on the value of the absolute
bandgap and the frequencies of localized defect modes. We reveal that a maximum
absolute bandgap for this structure is achieved for an intermediate rotation
angle of the holes. This angle depends on the radius of the holes and the
refractive index of the background material. We also study the properties of
the defect modes created by missing holes, and discuss the mode tunability in
such structures.


title: Silicon Drift Detector Readout Electronics for a Compton Camera

abstract:
  A prototype detector for Compton camera imaging is under development. A
monolithic array of 19 channel Silicon drift detector with on-chip electronics
is going to be used as a scatter detector for the prototype system. Custom
designed analog and digital readout electronics for this detector was first
tested by using a single cell Silicon drift detector. This paper describes the
readout architecture and presents the results of the measurement.


title: Peak finding through Scan Statistics

abstract:
  We discuss the conditions under which Scan Statistics can be fruitfully
implemented to signal a departure from the underlying probability model that
describes the experimental data. It is shown that local perturbations
(``bumps'' or ``excesses'' of events) are better dealt within this framework
and, in general, tests based on these statistics provide a powerful and
unbiased alternative to the traditional techniques related with the chi2 and
Kolmogorov distributions. Approximate formulas for the computation of Scan
Statistics in the range of interest for high energy and nuclear physics
applications are also presented.


title: Dynamic Nonlinear X-waves for Femtosecond Pulse Propagation in Water

abstract:
  Recent experiments on femtosecond pulses in water displayed long distance
propagation analogous to that reported in air. We verify this phenomena
numerically and show that the propagation is dynamic as opposed to self-guided.
Furthermore, we demonstrate that the propagation can be interpreted as due to
dynamic nonlinear X-waves whose robustness and role in long distance
propagation is shown to follow from the interplay between nonlinearity and
chromatic dispersion.


title: Local shear waves attenuation measurements by the MR methods

abstract:
  The essential feature of the method is the employment of Elasto-Magnetic
Resonance Spectroscopy (EMRS) for precise local measurements of the attenuation
of shear elastic waves introduced into a biological sample. Such a measurement
can be accomplished by combining the EMRS method with such methods, in which
collective dislocations of spins are induced by external physical factors, such
as variable electric field, strong magnetic field gradient or longitudinal
elastic wave. Theoretical bases of the method presented, related with the
external factors, are discussed in the present paper.


title:
Entropy Generation by a Maxwell Demon in the Sequential Sorting of the
  Particles in an Ideal Gas

abstract:
  This paper revisits the Maxwell Demon Problem. Representing the demon with a
simple physical computer composed of a single memory element, we demonstrate
that the average minimum entropy increase of the universe due to sorting of
particles with a Maxwell Demon is eta=0.8400 for particles that are initially
randomly distributed.


title:
A generalized exchange-correlation functional: the Neural-Networks
  approach

abstract:
  A Neural-Networks-based approach is proposed to construct a new type of
exchange-correlation functional for density functional theory. It is applied to
improve B3LYP functional by taking into account of high-order contributions to
the exchange-correlation functional. The improved B3LYP functional is based on
a neural network whose structure and synaptic weights are determined from 116
known experimental atomization energies, ionization potentials, proton
affinities or total atomic energies which were used by Becke in his pioneer
work on the hybrid functionals [J. Chem. Phys. ${\bf 98}$, 5648 (1993)]. It
leads to better agreement between the first-principles calculation results and
these 116 experimental data. The new B3LYP functional is further tested by
applying it to calculate the ionization potentials of 24 molecules of the G2
test set. The 6-311+G(3{\it df},2{\it p}) basis set is employed in the
calculation, and the resulting root-mean-square error is reduced to 2.2
kcal$\cdot$mol$^{-1}$ in comparison to 3.6 kcal$\cdot$mol$^{-1}$ of
conventional B3LYP/6-311+G(3{\it df},2{\it p}) calculation.


title:
Oscillatory Motion of Rising Bubbles in Wormlike Micellar Fluids with
  Different Microstructures

abstract:
  Previous observations of the nontransient oscillations of rising bubbles and
falling spheres in wormlike micellar fluids were limited to a single surfactant
system. We present an extensive survey of rising bubbles in another system, an
aqueous solution of cetylpyridinium chloride and sodium salicylate, with and
without NaCl, across a range of concentrations and temperatures. Two different
types of oscillation are seen in different concentration ranges, each with its
own temperature dependence. Rheological data allows for the identification of
these different hydrodynamic states with different fluid microstructures.


title:
Accounting for Breit interaction in actinide and superheavy element
  compounds: 1. General remarks

abstract:
  The incorporation of the Breit interaction in atomic and molecular
calculations is discussed in the framework of four-component all-electron and
two-component relativistic effective core potential (RECP)formalisms.
Contributions of the Breit interaction between different core and valence
shells are studied in the Dirac-Fock approximation for the uranium, plutonium,
ekathallium (Z=113), ekalead (Z=114) and other heavy atoms. It is shown that
the two-electron Breit effects between the valence electrons can be neglected
for "chemical accuracy" (1 kcal/mol) of calculation of spectroscopic properties
of systems containing superheavy elements and actinides whereas large core-core
and core-valence Breit contributions can be efficiently described by
one-electron RECP operators. Different versions of the generalized RECPs with
the Breit interaction taken into account are constructed for uranium and
plutonium and tested in comparison with the corresponding all-electron
four-component calculations.


title: On the magnitude of the energy flow inherent in zero-point radiation

abstract:
  The spectrum of zero-point radiation is relativistically invariant and its
spectral density function is therefore inversely proportional to the cubes of
its wavelengths. For its energy to be finite, there must exist a minimum
wavelength, $q_\lambda$. The measurements of the apparent attraction between
two uncharged conductor plates, placed in a vacuum at a temperature close to
absolute zero, made by Sparnaay in 1958 allow us to deduce that the energy flow
of the zero-point radiation which comes of or into an area $(q_\lambda)^2$,
corresponds with the emission of one photon of wavelength $q_\lambda$ per
$q_\tau$ $(q_\tau=q_\lambda/c)$, plus one photon of wavelength $2q_\lambda$ per
$2^3q_\tau$, etc., up to one photon of wavelength $nq_\lambda$ per $n^3q_\tau$.
This energy flow is enormous, but Sparnaay's experiments implied only photons
whose wavelengths were greater than $5\times10^{-5}$ cm, and zero-point
radiation may include only photons with wavelengths greater than $xq_\lambda$,
being $x$ an integer, perhaps very great.


title:
Protein folding in high-dimensional spaces:hypergutters and the role of
  non-native interactions

abstract:
  We explore the consequences of very high dimensionality in the dynamical
landscape of protein folding. Consideration of both typical range of
stabilising interactions, and folding rates themselves, leads to a model of the
energy hypersurface that is characterised by the structure of diffusive
"hypergutters" as well as the familiar "funnels". Several general predictions
result: (1) intermediate subspaces of configurations will always be visited;
(2) specific but non-native interactions are important in stabilising these
low-dimensional diffusive searches on the folding pathway; (3) sequential
barriers will commonly be found, even in "two-state"proteins; (4) very early
times will show charactreristic departures from single-exponential kinetics;
(5) contributions of non-native interactions to phi-values are calculable, and
may be significant. The example of a three-helix bundle is treated in more
detail as an illustration. The model also shows that high-dimensional
structures provide conceptual relations between the "folding funnel",
"diffusion-collision", "nucleation-condensation" and "topomer search" models of
protein folding. It suggests that kinetic strategies for fast folding may be
encoded rather generally in non-native, rather than native interactions. The
predictions are related to very recent findings in experiment and simulation.


title:
A new condition to identify isotropic dielectric-magnetic materials
  displaying negative phase velocity

abstract:
  The derivation of a new condition for characterizing isotropic
dielectric-magnetic materials exhibiting negative phase velocity, and the
equivalence of that condition with previously derived conditions, are
presented.


title: The nonlinear directional coupler. An analytic solution

abstract:
  Linear and nonlinear directional couplers are currently used in fiber optics
communications. They may also play a role in multiphoton approaches to quantum
information processing if accurate control is obtained over the phases and
polarizations of the signals at the output of the coupler. With this
motivation, the constants of motion of the coupler equation are used to obtain
an explicit analytical solution for the nonlinear coupler.


title: Currents Induced by Charges Moving in Semiconductor

abstract:
  The method of computation of currents induced on electrodes by charges moving
in vacuum was introduced by Shockley and Ramo. In presented paper, this method
is generalised for charges moving in a media.


title:
Harmonic generation by atoms in circularly polarized laser fields:
  far-off and near resonances regimes

abstract:
  The generation of harmonics by atoms interacting with two circularly
polarized and frequency related laser fields is addressed through ab initio
numerical simulations. A detailed charaterization of a few specific harmonics
is given. In particular, the two different cases where the total energy
absorbed through photons is far-off or close to the energy gap between
different atomic states are investigated. It is found that the conversion
efficiency in the harmonic generation is strongly dependent on the inner atomic
structure and in certain specific cases it can be significantly enhanced within
a small frequency range.


title: Bayesian Wavelet Based Signal and Image Separation

abstract:
  In this contribution, we consider the problem of blind source separation in a
Bayesian estimation framework. The wavelet representation allows us to assign
an adequate prior distribution to the wavelet coefficients of the sources. MCMC
algorithms are implemented to test the validity of the proposed approach, and
the non linear approximation of the wavelet transform is exploited to aleviate
the algorithm.


title: Temperature and pressure in nonextensive thermostatistics

abstract:
  The definitions of the temperature in the nonextensive statistical
thermodynamics based on Tsallis entropy are analyzed. A definition of pressure
is proposed for nonadditive systems by using a nonadditive effective volume.
The thermodynamics of nonadditive photon gas is discussed on this basis. We
show that the Stefan-Boltzmann law can be preserved within nonextensive
thermodynamics.


title: On the Astronomical Records and Babylonian Chronology

abstract:
  We outline the priority of high quality data of astronomical content as our
strategy for the analysis of the ancient astronomical records in the search of
the absolute chronology of the Near East in II millennium BC. The
correspondingly defined set of data for two lunar eclipses of EAE 20 and 21
tablets linked to Ur III period enables us the choice of eclipses of 27 June
1954 BC and 17 March 1912 BC; here the information on the exit position of the
darkening of the lunar disk acts as a crucial informator survived in the
records. We then discuss why the 56/64 year Venus cycle cannot be traced in the
Venus Tablet and therefore cannot serve as an anchor for the search of
chronologies. The month length method is discussed as well. In sum the
available data support the Ultra-Low Chronology proposed in the book by
H.Gasche, J.A.Armstrong, S.W.Cole and V.G.Gurzadyan, "Dating the Fall of
Babylon" (1998) and, particularly, leave no astronomical background for the
High Chronology. Ultra-Low Chronology is supported also by archaeological,
dendrochronological, Assyrian king lists and other data as summarized at the
Intern. Colloquium on Ancient Near Eastern Chronology (Ghent, July, 2000).


title: The Venus Tablet and Refraction

abstract:
  It is shown that the refraction near the horizon is introducing an additional
bias into the Venus Tablet of Ammisaduqa, which is able to influence the
interpretation of the data. We then discuss the attempts to link certain solar
eclipses to the birth of Shamshi-Adad and conclude that a record of a single
solar eclipse without description of details and/or unambiguous historical
links, can hardly act as a reliable anchor.


title: Quantum Gravity Phenomenology

abstract:
  I give a brief non-technical review of "Quantum Gravity Phenomenology" and in
particular I describe some studies which should soon allow to establish
valuable data-based constraints on the short-distance structure of spacetime.


title: A Newtonian pre-introduction to gravitational lenses

abstract:
  Understanding the deflection of light by a massive deflector, as well as the
associated gravitational lens phenomena, require the use of the theory of
General Relativity. I consider here a classical approach, based on Newton's
equation of motion for massive particles. These particles are emitted by a
distant source and deflected by the gravitational field of a (opaque) star or
of a (transparent) galaxy. The dependence of the deviation angle $D$ on the
impact parameter $b$, and the geometry of the (source, deflector, earth)
triplet, imply that different particle trajectories may reach an earth based
observer. Since $D(b)$ does not depend on the mass of the particles, it is
tempting to set the particles' velocity equal to the speed of light to get a
(Newtonian) flavor of gravitational lenses phenomena. Orders of magnitude are
obtained through a non technical approach and can be compared to the General
Relativity results.


title:
Radiative collisional heating at the Doppler limit for laser-cooled
  magnesium atoms

abstract:
  We report Monte Carlo wave function simulation results on cold collisions
between magnesium atoms in a strong red-detuned laser field. This is the normal
situation e.g. in magneto-optical traps (MOT). The Doppler limit heating rate
due to radiative collisions is calculated for Mg-24 atoms in a magneto-optical
trap based on the singlet S_0 - singlet P_1 atomic laser cooling transition. We
find that radiative heating does not seem to affect the Doppler limit in this
case. We also describe a channelling mechanism due to the missing Q branch in
the excitation scheme, which could lead to a suppression of inelastic
collisions, and find that this mechanism is not present in our simulation
results due to the multistate character of the excitation process.


title: The Fuzzy Space Time Paradigm

abstract:
  We briefly review theories of fuzzy spacetime or with a spacetime cut off,
particularising on the author's own model which correctloy predicted the
present cosmological model of an accelerating universe and dark energy, and
which points to a unification of electromagnetism and gravitation and which has
several ramifications including the prediction of deviations from Special
Relativity at Ultra High Energies, as observations of Ultra High Energy Cosmic
Rays seem to confirm, amongst other issues.


title: On the Faster-Than-Light Motions in Electrodynamics

abstract:
  A variant of electrodynamics is constructed in which faster-than-light
motions are possible.


title: A Remark on the Kramers Problem

abstract:
  We present new point of view on the old problem, the Kramers problem. The
passage from the Fokker-Planck equation to the Smoluchowski equation, including
corrections to the Smoluchowski current, is treated through an asymptotic
expansion of the solution of the stochastic dynamical equations. The case of an
extremely weak force of friction is also discussed


title:
The exact proof that Maxwell equations with the 3D E and B are not
  Lorentz covariant equations. The new Lorentz invariant field equations

abstract:
  In this paper it will be exactly proved both in the geometric algebra and
tensor formalisms that the usual Maxwell equations with the three-dimensional
(3D) vectors of the electric and magnetic fields, E{bold} and B{bold}
respectively, are not, contrary to the general opinion, Lorentz covariant
equations. Consequently they are not equivalent to the field equations with the
observer independent quantities, the electromagnetic field tensor Fsup{ab}
(tensor formalism) or with the bivector field F (the geometric algebra
formalism). Different 4D algebric objects are used to represent the standard
observer dependent and the new observer independent electric and magnetic
fields. The proof of a fundamental disagreement between the standard
electromagnetism and the special relativity does not depend on the character of
the 4D algebric object used to represent the electric and magnetic fields. The
Lorentz invariant field equations are presented with 1-vectors E and B,
bivectors Esub{HL} and Bsub{HL} and the abstract tensors, the 4-vectors Esup{a}
and Bsup{a}. All these quantities are defined without reference frames. Such
field equations are in a complete agreement with experiments.


title: Modeling and Study of the Cerenkov Effect

abstract:
  The studies realized in INRNE (Institute for Nuclear Research and Nuclear
Energy) particulary in cosmic rays detection and construction of Muonic
Cerenkov Telescope in University of Blagoevgrad [1] shows the need to develop a
theoretical model based on observed phenomenon and to refine it for the
detection system optimisation. The effect was introduced in EGS4 code system.
The first simulations were consecrated to different geometry of water tank in
total reflection. The model was compared with experimental data realised with
gamma source using the telescope. A simple atmospheric model is introduced in
EGS4. The comparison between CORSIKA and EGS4 codes was realised.


title: Gravity-Sensitive Quantum Dynamics in Cold Atoms

abstract:
  We subject a falling cloud of cold cesium atoms to periodic kicks from a
sinusoidal potential created by a vertical standing wave of off-resonant laser
light. By controllably accelerating the potential, we show quantum accelerator
mode dynamics to be highly sensitive to the effective gravitational
acceleration when this is close to specific, resonant values. This quantum
sensitivity to a control parameter is reminiscent of that associated with
classical chaos, and promises techniques for precision measurement.


title: The Optimal Faucet

abstract:
  The production of small fluid droplets relies on an instability of solutions
to the Young-Laplace equation. We ask whether smaller droplets can be produced
by changing the shape of the nozzle. At a given critical pressure, the circular
nozzle actually produces the largest droplet. The droplet volume can be
decreased by up to 18% using a triangular nozzle with stretched corners.


title: String Theory: a theory in search of an experiment

abstract:
  It is argued that string theory may pose new conceptual issues for the
history and philosophy of science.


title: A new way of defining unstable states

abstract:
  We define a new unstable state in the Friedrichs model of a two-level atom.
This unstable state is a complex eigenstate of the time evolution operator
$\exp(-iHt)$ with a restricted test function space, which is obtained from
causality conditions. The unstable state shows exact exponential decay for
$t\ge0$. Its emitted field is confined inside the future light-cone. In this
way the long-standing problem of exponential catastrophe is removed. This is an
example of quantum mechanics outside Hilbert space, which consists of
generalized eigenstates in a distribution space, and a dual (test function)
space.


title:
Multifractal analysis of Mt. St. Helens seismicity as a tool for
  identifying eruptive activity

abstract:
  We present a multifractal analysis of Mount St. Helens seismic activity
during 1980-2002. The seismic time distribution is studied in relation to the
eruptive activity, mainly marked by the 1980 major explosive eruptions and by
the 1980-1986 dome building eruptions. The spectrum of the generalized fractal
dimensions, i.e. Dq vs q, extracted from the data, allows us to identify two
main earthquake time-distribution patterns. The first one exhibits a
multifractal clustering correlated to the intense seismic swarms of the dome
building activity. The second one is characterized by an almost constant value
of Dq 1, as for a random uniform distribution. The time evolution of Dq (for
q=0,2) calculated on a fixed number of events window and at different depths,
shows that the brittle mechanical response of the shallow layers to rapid magma
intrusions, during the eruptive periods, is revealed by sharp changes, acting
at a short time scale (order of days), and by the lowest values of Dq (0.3).
Conversely, for deeper earthquakes, characterized by intense seismic swarms, Dq
do not show obvious changes during the whole analyzed period, suggesting that
the earthquakes, related to the deep magma supply system, are characterized by
a minor degree of clustering, which is independent of the eruptive activity.


title: Tests of silicon sensors for the CMS pixel detector

abstract:
  The tracking system of the CMS experiment, currently under construction at
the Large Hadron Collider (LHC) at CERN (Geneva, Switzerland), will include a
silicon pixel detector providing three spacial measurements in its final
configuration for tracks produced in high energy pp collisions. In this paper
we present the results of test beam measurements performed at CERN on
irradiated silicon pixel sensors. Lorentz angle and charge collection
efficiency were measured for two sensor designs and at various bias voltages.


title:
Magnetic Field Structure and Stochastic Reconnection in a Partially
  Ionized Gas

abstract:
  We consider stochastic reconnection in a magnetized, partially ionized
medium. Stochastic reconnection is a generic effect, due to field line
wandering, in which the speed of reconnection is determined by the ability of
ejected plasma to diffuse away from the current sheet along magnetic field
lines, rather than by the details of current sheet structure. We consider the
limit of weak stochasticity, so that the mean magnetic field energy density is
greater than either the turbulent kinetic energy density or the energy density
associated with the fluctuating component of the field. We consider field line
stochasticity generated through a turbulent cascade, which leads us to consider
the effect of neutral drag on the turbulent cascade of energy. In a
collisionless plasma, neutral particle viscosity and ion-neutral drag will damp
mid-scale turbulent motions, but the power spectrum of the magnetic
perturbations extends below the viscous cutoff scale. We give a simple physical
picture of the magnetic field structure below this cutoff, consistent with
numerical experiments. We provide arguments for the reemergence of the
turbulent cascade well below the viscous cut-off scale and derive estimates for
field line diffusion on all scales. We note that this explains the persistence
of a single power law form for the turbulent power spectrum of the interstellar
medium, from scales of tens of parsecs down to thousands of kilometers. We find
that under typical conditions in the ISM stochastic reconnection speeds are
reduced by the presence of neutrals, but by no more than an order of magnitude.


title: PARFAIT: GNSS-R coastal altimetry

abstract:
  GNSS-R signals contain a coherent and an incoherent component. A new
algorithm for coherent phase altimetry over rough ocean surfaces, called
PARFAIT, has been developed and implemented in Starlab's STARLIGHT GNSS-R
software package. In this paper we report our extraction and analysis of the
coherent component of L1 GPS-R signals collected during the ESTEC Bridge 2
experimental campaign using this technique. The altimetric results have been
compared with a GPS-buoy calibrated tide model with a resulting precision of
the order 1 cm.


title: Ablation de ZnO par laser UV (193 nm) : Nano-agregats en phase gazeuse

abstract:
  The condensation of zinc oxide nano clusters produced in gas phase has been
evidenced in the ablation of a ZnO solid target by a pulsed ArF laser. We
compare the spatio-temporal evolution of the shape of ZnO ablated plasma plume,
both in vacuum and in controlled gas environments (Helium and/or Oxygen) from
monitoring with CCD camera and from spectroscopic studies. The expansion of the
plasma plume and the growth of the nanoclusters depend strongly upon the
collisions between the ablated particles and surrounding gas molecules, as well
as on the chemical reactions in the case of oxygen. The spectra of the observed
plasma emittion are mainly due to atomic transitions in the neutral Zn. We have
also observed the photoluminescence of the nanoclusters suspended in the gas
and their decomposition in the beam of ArF laser.