title: The Inverse Energy Cascade of Two-Dimensional Turbulence

abstract:
  This thesis presents an experimental study of the inverse energy cascade as
it occurs in an electromagnetically forced soap film. It focuses on
characterizing important features of the inverse cascade such as it's range,
how energy is distributed over the range and how energy flows through the
range. The thesis also probes the assumption of scale invariance that is
associated with the existence of an inverse cascade. These investigations
demonstrate that the extent of the inverse cascade range and the behavior of
the energy distribution are in agreement with dimensional predictions. The
energy flow in the inverse cascade range is shown to be well described by exact
mathematical predictions obtained from the Navier-Stokes equation. At no time
does the energy flow in the inverse cascade range produced by the e-m cell
behave inertially or in a scale invariant manner. Evidence that the cascade
could become scale invariant should an inertial range develop is presented, as
are the requirements that a system must satisfy to create such an inertial
range.


title: What is mass?

abstract:
  Does the mass of bodies depend on their velocity? Is the mass additive if
separate bodies are joined together to form a composite system? Is the mass of
an isolated system conserved? Different teachers of physics and specialists
give different answers to these questions because there is no general agreement
on the definition of mass..We shall show that the notion of the
velocity-dependent relativistic mass should be given preference over that of
the rest mass.


title: New Improvements for Mie Scattering Calculations

abstract:
  New improvements to compute Mie scattering quantities are presented. They are
based on a detailed analysis of the various sources of error in Mie
computations and on mathematical justifications. The algorithm developed on
these improvements proves to be reliable and efficient, without size ($x=2\pi
R/\lambda$) nor refractive index ($m=m_R-{\rm i}m_I$) limitations, and the user
has a choice to fix in advance the desired precision in the results. It also
includes a new and efficient method to initiate the downward recurrences of
Bessel functions.


title:
Energy dissipation and scattering angle distribution analysis of the
  classical trajectory calculations of methane scattering from a Ni(111)
  surface

abstract:
  We present classical trajectory calculations of the rotational vibrational
scattering of a non-rigid methane molecule from a Ni(111) surface. Energy
dissipation and scattering angles have been studied as a function of the
translational kinetic energy, the incidence angle, the (rotational) nozzle
temperature, and the surface temperature. Scattering angles are somewhat
towards the surface for the incidence angles of 30, 45, and 60 degree at a
translational energy of 96 kJ/mol. Energy loss is primarily from the normal
component of the translational energy. It is transfered for somewhat more than
half to the surface and the rest is transfered mostly to rotational motion. The
spread in the change of translational energy has a basis in the spread of the
transfer to rotational energy, and can be enhanced by raising of the surface
temperature through the transfer process to the surface motion.


title: Superluminal Localized Waves of Electromagnetic Field in Vacuo

abstract:
  Presented is an overview of electromagnetic versions of the so-called X-type
waves intensively studied since their invention in early 1990.-ies in
ultrasonics. These waves may be extremely localized both laterally and
longitudinally and - what has been considered as most startling - propagate
superluminally without apparent spread. Spotlighted are the issues of the
relativistic causality, variety of mathematical description and possibilities
of practical applications of the waves.


title:
Extreme Ultraviolet (EUV) Sources for Lithography based on Synchrotron
  Radiation

abstract:
  The study presented here was initiated by a discussion to investigate the
possibility of using synchrotron radiation as a source for the Next Generation
Lithography (NGL) based on the EUV-concept (Extreme Ultra-Violet; here 13.5 nm
or 11.3 nm radiation, respectively). The requirements are: 50 W, 2% bandwidth
and minimal power outside this bandwidth. Three options were investigated. The
first two deal with radiation from bending magnets and undulators. The results
confirm the earlier work by Oxfords Instrument and others that these
light-sources lack in-band power while emitting excessive out-of-band
radiation. The third approach is a FEL (Free Electron Laser) driven by a 500
MeV linear accelerator with a superconducting mini-undulator as radiation
emitting device. Such a device would produce in-band EUV-power in excess of 50
W with negligible out-of-band power.


title: QED classically - An intuitive approach

abstract:
  This paper deals with QED-particles and the interaction between them on a
classical level. The Maxwell-equations are used mainly. (Proofs are not used in
a mathematical but intuitive sense.) In the first step the main statements are
presented. The corresponding proofs are given in the second and final step.
  Main statements: I. An electron/positron is a sink/source of electromagnetic
scalar quanta. II. These electromagnetic scalar field quanta should clearly be
identified with photons. III. Charge-charge interaction is easily conceivable.
IV. The magnetic vector field constitutes a flow of photons. V. It becomes
clear, why a charged particle is deflected perpendicular to the magnetic field
lines.


title: High-resolution TOF with RPCs

abstract:
  In this work we describe some recent results concerning the application of
Resistive Plate Chambers operated in avalanche mode at atmospheric pressure for
high-resolution time-of-flight measurements. A combination of multiple,
mechanically accurate, thin gas gaps and state-of-the-art electronics yielded
an overall (detector plus electronics) timing accuracy better than 50 ps sigma
with a detection efficiency up to 99% for MIPs. Single gap chambers were also
tested in order to clarify experimentally several aspects of the mode of
operation of these detectors. These results open perspectives of affordable and
reliable high granularity large area TOF detectors, with an efficiency and time
resolution comparable to the existing scintillator-based TOF technology but
with a significantly, up to an order of magnitude, lower price per channel.


title: On non-measurable sets and invariant tori

abstract:
  The question: "How many different trajectories are there on a single
invariant torus within the phase space of an integrable Hamiltonian system?" is
posed. A rigorous answer to the question is found both for the rational and the
irrational tori. The relevant notion of non-measurable sets is discussed.


title:
Calculations of collisions between cold alkaline earth atoms in a weak
  laser field

abstract:
  We calculate the light-induced collisional loss of laser-cooled and trapped
magnesium atoms for detunings up to 50 atomic linewidths to the red of the
^1S_0-^1P_1 cooling transition. We evaluate loss rate coefficients due to both
radiative and nonradiative state-changing mechanisms for temperatures at and
below the Doppler cooling temperature. We solve the Schrodinger equation with a
complex potential to represent spontaneous decay, but also give analytic models
for various limits. Vibrational structure due to molecular photoassociation is
present in the trap loss spectrum. Relatively broad structure due to absorption
to the Mg_2 ^1Sigma_u state occurs for detunings larger than about 10 atomic
linewidths. Much sharper structure, especially evident at low temperature,
occurs even at smaller detunings due to of Mg_2 ^1Pi_g absorption, which is
weakly allowed due to relativistic retardation corrections to the forbidden
dipole transition strength. We also perform model studies for the other
alkaline earth species Ca, Sr, and Ba and for Yb, and find similar qualitative
behavior as for Mg.


title: Vacuum charges within a teleparallel Weyl tensor

abstract:
  A comparison is given between the Newtonian and Einsteinian frames of
gravitation. From this it is shown that there exist a weak connection to
gravitation and electromagnetism. This connection is then studied more
thoroughly with the Weyl tensor and with the electromagnetic vacuum \Lambda.
Which dictates General Relativity should be reformulated to confer to a
`Einstein-Cartan-Weyl' geometry. Where it is seen that the Gravitational
Constant is the inverse of the Compton wavelength shown through a Weyl gauge
potential of form [F_{\alpha\beta}+A_{a\beta}^\alpha]_{;\beta}. The gauge
potential along with Einstein-Cartan geometry is argued to explain superluminal
velocities observed within General Relativity.


title: The Nonlinear Maxwell Theory---an Outline

abstract:
  The goal of this paper is to sketch a broader outline of the mathematical
structures present in the Nonlinear Maxwell Theory in continuation of work
presented in my previous articles. In particular, I display new types of both
dynamic and static solutions of the Nonlinear Maxwell Equations (NM). I point
out how the resulting theory ties to the Quantum Mechanics of Correlated
Electrons inasmuch as it provides a mesoscopic description of phenomena like
nonresistive charge transport, static magnetic flux tubes, and charge stripes
in a way consistent with both the phenomenology and the microscopic principles.
In addition, I point at a bunch of geometric structures intrinsic for the
theory. On one hand, the presence of these structures indicates that the
equations at hand can be used as `probing tools' for purely geometric
exploration of low-dimensional manifolds. On the other hand, global aspects of
these structures are in my view prerequisite to incorporating (quantum)
informational features of Correlated Electron Systems within the framework of
the Nonlinear Maxwell Theory.


title:
A Proposed New Test of General Relativity and a Possible Solution to the
  Cosmological Constant Problem

abstract:
  Following a conjecture of Feynman, we explore the possibility that only those
energy forms that are associated with (massive or massless) particles couple to
the gravitational field, but not others. We propose an experiment to deflect
electrons by a small charged sphere to determine if the standard general
relativity or this modified one corresponds to reality. The outcome of this
experiment may also solve the cosmological constant problem.


title: Penning collisions of laser-cooled metastable helium atoms

abstract:
  We present experimental results on the two-body loss rates in a
magneto-optical trap of metastable helium atoms. Absolute rates are measured in
a systematic way for several laser detunings ranging from -5 to -30 MHz and at
different intensities, by monitoring the decay of the trap fluorescence. The
dependence of the two-body loss rate coefficient $\beta$ on the excited state
($2^3P_2$) and metastable state ($2^3S_1$) populations is also investigated.
  From these results we infer a rather uniform rate constant
$K_{sp}=(1{\pm}0.4)\times10^{-7}$ cm$^3$/s.


title: Efficient magneto-optical trapping of a metastable helium gas

abstract:
  This article presents a new experiment aiming at BEC of metastable helium
atoms. It describes the design of a high flux discharge source of atoms and a
robust laser system using a DBR diode coupled with a high power Yb doped fiber
amplifier for manipulating the beam of metastable atoms. The atoms are trapped
in a small quartz cell in an extreme high vacuum. The trapping design uses an
additional laser (repumper) and allows the capture of a large number of
metastable helium atoms (approximately $10^9$) in a geometry favorable for
loading a tight magnetostatic trap.


title: Delay Equation for Charged Brown Particle

abstract:
  In previous work (physics/0004026) was shown, with the help of numerical
calculations, that the effective Brown temperature for charged particle is
lower than that for particle without charge. Here we derive this result without
numerical calculations, integrating the delay equation analytically, as for
zero, so for nonzero viscosity.


title:
Elementar Objects of Matter: Universality, Hierarchy, Isomorphysm,
  Dynamical Spectrum

abstract:
  In the frame of Wave Universe Concept (WU Concept) it is presented the
alternative approach to the effective description of Elementar Objects of
Matter (EOM) of micro and megaworld hierarchy, in particular, of particles in
subatomic physics.
  According to the Wave Universe Concept (WU Concept), discrete spectrum of EOM
is close connected, generate by universal spectrum of physically preferable,
elite velocities in the Universe.
  The special attantion to analysis and precise description of central set of
EOM - stationary states (of EOM) is payed.
  In particular, sufficiently precise representations for mass values, cross
relations between masses of main important objects of particle physics (proton,
pion, main mesons, etc.) are obtained.
  Obtained representations for the hierarchy of characteristic dimensional
parameters, for instance, for the mass spectrum - mass formula are not
contained any divergencies - its are simple, compact, possess clear physical
sence and have not any kind of fitting parameters. With this, the competence
field of these representations is practically indefinitely - apparently, "all"
Wave Universe for wide set EOM of micro and megaworld.


title:
Phantom of Higgs Boson Versus Hierarchy of Stationary States of
  Superhigh Energies

abstract:
  As is known, the Standard Model mainly ideologically and qualitatively focuss
the experimenters in their search of new mass states (of EP- elementary
particles). The exact quantitative prognosis of their properties, especially of
masses, lays outside opportunities of the usual theory. Model of Stationary
states of EP within the framework of the Wave Universe Concept [Chechelnitsky,
1980-2001] points on existence of Hierarchy of physically distinguished -
stationary (elite, dominant) states described by the mass formulas, in
particular, in a range 10-210 Gev/c^2.
  The states close to:
  ..., 101.5; 107.3; 112.76-113; 139.5-143; 147.6; 202 Gev/c^2 should be
observed.
  Apparently, the experiment already confirms this prognosis in a range up to
100 Gev/c^2. You see preferable states, observable already now in experiment,
it - not rejected by the usual theory as the candidates in constituents of
Standard model (for example, not holding Higgs bosons), but quite real displays
of stationary (first of all, -dominant) mass states. Last data of L3 (CERN)
Collaboration really specify displays of new mass states and close to 103.7;
108.9; 114.5 Gev/c^2.


title: Testing Lorentz and CPT symmetry with hydrogen masers

abstract:
  We present details from a recent test of Lorentz and CPT symmetry using
hydrogen masers. We have placed a new limit on Lorentz and CPT violation of the
proton in terms of a recent standard model extension by placing a bound on
sidereal variation of the F = 1 Zeeman frequency in hydrogen. Here, the
theoretical standard model extension is reviewed. The operating principles of
the maser and the double resonance technique used to measure the Zeeman
frequency are discussed. The characterization of systematic effects is
described, and the method of data analysis is presented. We compare our result
to other recent experiments, and discuss potential steps to improve our
measurement.


title: Adding Resistances and Capacitances in Introductory Electricity

abstract:
  We propose a unified approach to addition of resistors and capacitors such
that the formulae are always simply additive. This approach has the advantage
of being consistent with the intuition of the students. To demonstrate our
point of view, we re-work some well-known end-of-the-chapter textbook problems
and propose some additional new problems.


title: Acoustic scattering by a cylinder near a pressure release surface

abstract:
  This paper presents a study of acoustic scattering by a cylinder of either
infinite or finite length near a flat pressure-release surface. A novel
self-consistent method is developed to describe the multiple scattering
interactions between the cylinder and the surface. The complete scattering
amplitude for the cylinder is derived from a set of equations, and is
numerically evaluated. The results show that the presence of the surface can
either enhance or reduce the scattering of the cylinder, depending on the
frequency, the composition of the cylinder, and the distance between the
cylinder and the surface. Both air-filled and rigid cylinders are considered.


title:
The Origin Of Galaxies. Mass Particles, Time, Gravitation and Black
  Holes in Perspective of the CER Wave Packet Concept of Mass and Charge

abstract:
  The CER concept which describes the physical origin of mass and charge has
shown that mass particles are of electromagnetic origin and consist of
condensed circular polarized electromagnetic radiation, EMR. It has also been
shown that this theory predicts the existence of the most fundamental particles
in the Standard Model, leptons and quarks of the first generation. Heavier mass
particles such as mesons and baryons are found to be composed of superimposed
CER wave packets. Using this knowledge it is possible to draw conclusions
regarding the concept of time, the nature of gravitation and the formation of
galaxies.


title:
On Whether People Have the Capacity to Make Observations of Mutually
  Exclusive Physical Phenomena Simultaneously

abstract:
  It has been shown by Einstein, Podolsky, and Rosen that in quantum mechanics
either one of two different wave functions predicting specific values for
quantities represented by non-commuting Hermitian operators can characterize
the same physical existent, without a physical interaction responsible for
which wave function occurs. This result means that one can make predictions
regarding mutually exclusive features of a physical existent. It is important
to ask whether people have the capacity to make observations of mutually
exclusive phenomena. Our everyday experience informs us that a human observer
is capable of observing only one set of physical circumstances at a time.
Evidence from psychology, though, indicates that people may have the capacity
to make observations of mutually exclusive physical phenomena, even though this
capacity is not generally recognized. Working independently, Sigmund Freud and
William James provided some of this evidence. How the nature of the quantum
mechanical wave function is associated with the problem posed by Einstein,
Podolsky, and Rosen is addressed at the end of the paper.


title: Nonlocal reflection by photonic barriers

abstract:
  The time behaviour of microwaves undergoing partial reflection by photonic
barriers was measured in the time and in the frequency domain. It was observed
that unlike the duration of partial reflection by dielectric layers, the
measured reflection duration of barriers is independent of their length. The
experimental results point to a nonlocal behaviour of evanescent modes at least
over a distance of some ten wavelengths. Evanescent modes correspond to
photonic tunnelling in quantum mechanics.


title: Multi-bunch generation by thermionic gun

abstract:
  KEK-ATF is studying the low-emittance multi-bunch electron beam for the
future linear collider. In ATF, thermionic gun is used to generate 20 bunches
electron beam with the bunch spacing of 2.8 ns. Due to a distortion of the gun
emission and the beam loading effect in the bunching system, the intensity for
each bunch is not uniform by up to 40 % at the end of the injector. We have
developed a system to correct the gun emission by precisely controlling the
cathode voltage with a function generator. For the beam loading effect, we have
introduced RF amplitude modulation on Sub Harmonic Buncher, SHB. By these
technique, bunch intensity uniformity was improved and beam transmission for
later bunches was recovered from 67% to 91%, but intensity for first five
bunches is still lower than others.


title: Hierarchy of Fundamental Interactions in Wave Universe

abstract:
  Fundamental interactions (FI) represent the core of physical World Picture,
compose the basis of observed in Universe phenomena and flowing in it
processes. In the frame of Wave Universe Concept (WU Concept) it is pointed to
essential features of observed FI set - its hierarchy, isomorphysm, recurrence
character. Hierarchy of alpha(k) fundamental interactions (FI) is shown by the
(infinite) Homological series alpha(k) = [(hi)^k]alpha(0) k=...-2, -1, 0, 1, 2,
>..., where hi-Fundamental parameter of hierarchy-Chechelnitsky Number
hi=3.66(6), alpha(0) = alpha = (e^2)/[(h/2pi)c] - Fine Structure constant.
Available experimental data sufficiently confirm the analitical representions
of the theory (WU Concept)


title: Complexity Through Nonextensivity

abstract:
  The problem of defining and studying complexity of a time series has
interested people for years. In the context of dynamical systems, Grassberger
has suggested that a slow approach of the entropy to its extensive asymptotic
limit is a sign of complexity. We investigate this idea further by information
theoretic and statistical mechanics techniques and show that these arguments
can be made precise, and that they generalize many previous approaches to
complexity, in particular unifying ideas from the physics literature with ideas
from learning and coding theory; there are even connections of this statistical
approach to algorithmic or Kolmogorov complexity. Moreover, a set of simple
axioms similar to those used by Shannon in his development of information
theory allows us to prove that the divergent part of the subextensive component
of the entropy is a unique complexity measure. We classify time series by their
complexities and demonstrate that beyond the `logarithmic' complexity classes
widely anticipated in the literature there are qualitatively more complex,
`power--law' classes which deserve more attention.


title: Solution of the two identical ion Penning trap final state

abstract:
  We have derived a closed form analytic expression for the asymptotic motion
of a pair of identical ions in a high precision Penning trap. The analytic
solution includes the effects of special relativity and the Coulomb interaction
between the ions. The existence and physical relevance of such a final state is
supported by a confluence of theoretical, experimental and numerical evidence.


title: Gravitation and Forces Induced by Zero-Point Phenomena

abstract:
  A recent proposal asserts that gravitational forces arise due to an
interaction between matter and vacuum electromagnetic zero-point radiation. The
present analysis demonstrates that forces induced on matter by zero-point
radiation arise in addition to gravitational forces. It is argued that
zero-point radiation should be red-shifted near large gravitational sources
while remaining essentially undetectable within freely falling reference
frames. On this basis, an effective weight of an observer stationed near the
surface of the Earth is derived for the case when zero-point radiation is
present.


title: Hyperfine splitting of $2^3S_1$ state in He$^3$

abstract:
  Relativistic corrections to the hyperfine splitting are calculated for the
triplet $2^3S_1$ state of the helium isotope He$^3$. High precision variational
wave functions are employed, where the electron-electron correlations are well
accounted for. Due to the unknown nuclear structure a comparison with the
experimental result is performed via He$^{3+}$ hyperfine splitting.
Surprisingly, the second order contribution due to Fermi interaction, in spite
of the additional small factor $m/M$, is very significant.


title: Gordian Unknots

abstract:
  Numerical simulations indicate that there exist conformations of the unknot,
tied on a finite piece of rope, entangled in such a manner, that they cannot be
disentangled to the torus conformation without cutting the rope. The simplest
example of such a gordian unknot is presented.


title:
Instability of Shear Waves in an Inhomogeneous Strongly Coupled Dusty
  Plasma

abstract:
  It is demonstrated that low frequency shear modes in a strongly coupled,
inhomogeneous, dusty plasma can grow on account of an instability involving the
dynamical charge fluctuations of the dust grains. The instability is driven by
the gradient of the equilibrium dust charge density and is associated with the
finite charging time of the dust grains. The present calculations, carried out
in the generalized hydrodynamic viscoelastic formalism, also bring out
important modifications in the threshold and growth rate of the instability due
to collective effects associated with coupling to the compressional mode.


title: High pressure operation of the triple-GEM detector in pure Ne, Ar and Xe

abstract:
  We study the performance of the triple-GEM (Gas Electron Multiplier) detector
in pure noble gases Ne, Ar and Xe, at different pressures varying from 1 to 10
atm. In Ar and Xe, the maximum attainable gain of the detector abruptly drops
down for pressures exceeding 3 atm. In contrast, the maximum gain in Ne was
found to increase with pressure, reaching a value of 100,000 at 7 atm. The
results obtained are of particular interest for developing noble gas-based
cryogenic particle detectors for solar neutrino and dark matter search.


title:
Time resolved tracking of a sound scatterer in a turbulent flow:
  non-stationary signal analysis and applications

abstract:
  It is known that ultrasound techniques yield non-intrusive measurements of
hydrodynamic flows. For example, the study of the echoes produced by a large
number of particle insonified by pulsed wavetrains has led to a now standard
velocimetry technique. In this paper, we propose to extend the method to the
continuous tracking of one single particle embedded in a complex flow. This
gives a Lagrangian measurement of the fluid motion, which is of importance in
mixing and turbulence studies. The method relies on the ability to resolve in
time the Doppler shift of the sound scattered by the continuously insonfied
particle.
  For this signal processing problem two classes of approaches are used:
time-frequency analysis and parametric high resolution methods. In the first
class we consider the spectrogram and reassigned spectrogram, and we apply it
to detect the motion of a small bead settling in a fluid at rest. In more
non-stationary turbulent flows where methods in the second class are more
robust, we have adapted an Approximated Maximum Likelihood technique coupled
with a generalized Kalman filter.


title: Measurement of Lagrangian velocity in fully developed turbulence

abstract:
  We have developed a new experimental technique to measure the Lagrangian
velocity of tracer particles in a turbulent flow, based on ultrasonic Doppler
tracking. This method yields a direct access to the velocity of a single
particule at a turbulent Reynolds number $R_{\lambda} = 740$. Its dynamics is
analyzed with two decades of time resolution, below the Lagrangian correlation
time. We observe that the Lagrangian velocity spectrum has a Lorentzian form
$E^{L}(\omega) = u_{rms}^{2} T_{L} / (1 + (T_{L}\omega)^{2})$, in agreement
with a Kolmogorov-like scaling in the inertial range. The probability density
function (PDF) of the velocity time increments displays a change of shape from
quasi-Gaussian a integral time scale to stretched exponential tails at the
smallest time increments. This intermittency, when measured from relative
scaling exponents of structure functions, is more pronounced than in the
Eulerian framework.


title: An Atom Faucet

abstract:
  We have constructed and modeled a simple and efficient source of slow atoms.
  From a background vapour loaded magneto-optical trap, a thin laser beam
extracts a continuous jet of cold rubidium atoms. In this setup, the extraction
column that is typical to leaking MOT systems is created without any optical
parts placed inside the vacuum chamber. For detailed analysis, we present a
simple 3D numerical simulation of the atomic motion in the presence of multiple
saturating laser fields combined with an inhomogeneous magnetic field. At a
pressure of $P_{\rm Rb87}=1 \times 10^{-8}$ mbar, the moderate laser power of
10 mW per beam generates a jet of flux $\Phi =1.3\times 10^8$ atoms/s with a
mean velocity of 14 m/s and a divergence of $<20$ mrad.


title: A Large Area Timing RPC

abstract:
  A large area Resistive Plate Chamber (RPC) with a total active surface of
160x10 cm2 was built and tested. The surface was segmented in two 5 cm wide
strips readout on both ends with custom, very high frequency, front end
electronics.
  A timing resolution between 50 and 75 ps sigma with an efficiency for Minimum
Ionizing Particles (MIPs) larger than 95% was attained over the whole active
area, in addition with a position resolution along the strips of 1.2 cm.
  Despite the large active area per electronic channel, the observed timing
resolution is remarkably close to the one previously obtained (50 ps sigma)
with much smaller chambers of about 10 cm2 area. These results open
perspectives of extending the application of timing RPCs to large area arrays
exposed to moderate particle multiplicities, where the low cost, good time
resolution, insensitivity to the magnetic field and compact mechanics may be
attractive when compared with the standard scintillator-based Time-of-Flight
(TOF) technology.


title: Thoughtful comments on 'Bessel beams and signal propagation'

abstract:
  In this paper we present thoughtful comments on the paper `Bessel beams and
signal propagation' showing that the main claims of that paper are wrong.
Moreover, we take the opportunity to show the non trivial and indeed surprising
result that a scalar pulse (i.e., a wave train of compact support in the time
domain) that is solution of the homogeneous wave equation (vector
($\vec{E},\vec{B}$) pulse that is solution of Maxwell equations) is such that
its {\em wave front} in some cases does travel with speed {\em greater} than
$c$, the speed of light . In order for a pulse to posses a front that travels
with speed $c$, an additional condition must be satisfied, namely the pulse
must have finite energy. When this condition is fulfilled the pulse still can
show peaks propagating with superluminal (or subluminal) velocities, but now
its wave front travels at speed $c$. These results are important because they
explain several experimental results obtained in recent experiments, where
superluminal velocities have been observed, without implying in any breakdown
of the Principle of Relativity.


title: Neural coding of naturalistic motion stimuli

abstract:
  We study a wide field motion sensitive neuron in the visual system of the
blowfly {\em Calliphora vicina}. By rotating the fly on a stepper motor outside
in a wooded area, and along an angular motion trajectory representative of
natural flight, we stimulate the fly's visual system with input that approaches
the natural situation. The neural response is analyzed in the framework of
information theory, using methods that are free from assumptions. We
demonstrate that information about the motion trajectory increases as the light
level increases over a natural range. This indicates that the fly's brain
utilizes the increase in photon flux to extract more information from the
photoreceptor array, suggesting that imprecision in neural signals is dominated
by photon shot noise in the physical input, rather than by noise generated
within the nervous system itself.


title:
Motion, Universality of Velocities, Masses in Wave Universe. Transitive
  States (Resonances) - Mass Spectrum

abstract:
  Wave Universe Concept (WU Concept) opens new wide possibilities for the
effective description of Elementar Objects of Matter (EOM) hierarchy, in
particular, of particles, resonances mass spectrum of subatomic (and HEP)
physics.
  The special attention to analysis and precise description of wide and
important set - Transitive states (resonances) of EOM is payed.
  Its are obtained sufficiently precise representations for mass values, cross
relations between masses of wide set objects of particle physics - metastable
resonances - (fast moving) Transitive states - in terms of representations of
Wave Universe Concept (WU Concept).
  Wide set of observed in experiments effects and connected with its resonances
(including - Darmstadt effect, ABC effect,etc.) may be effectively interpreted
in WU Concept and described with use of mass formula - as manifestation of
rapidly moving, physically distinguished transitive states (resonances)


title:
Local law-of-the-wall in complex topography: a confirmation from wind
  tunnel experiments

abstract:
  It is well known that in a neutrally-stratified turbulent flow in a deep
constant-stress layer above a flat surface, the variation of the mean velocity
with respect to the distance from the surface obeys the logarithmic law (the
so-called ``law-of-the-wall''). More recently, the same logarithmic law has
been found also in the presence of non flat surfaces. It governs the dynamics
of the mean velocity (i.e. all the smaller scales are averaged out) and
involves renormalized effective parameters. Recent numerical simulations
analyzed by the authors of the present Letter show that a more intrinsic
logarithmic shape actually takes place also at smaller scales. Such a
generalized law-of-the-wall involves effective parameters smoothly depending on
the position along the underlying topography. Here, we present wind tunnel
experimental evidence confirming and corroborating this new-found property. New
results and their physical interpretation are also presented and discussed.


title: Neutrinos

abstract:
  The general status of neutrino physics are given. The history of the
neutrino, starting from Pauli and Fermi, is presented. The phenomenological V-A
theory of the weak interaction and the unified theory of the weak and
electromagnetic interactions, the so-called Standard Model, are discussed. The
problems of of neutrino masses, neutrino mixing, and neutrino oscillations are
discussed in some details.

categories: physics.hist-ph hep-ph physics.ed-ph physics.gen-ph


title: Integrable Supersymmetric Fluid Mechanics from Superstrings

abstract:
  Following the construction of a model for the planar supersymmetric Chaplygin
gas, supersymmetric fluid mechanics in (1+1)-dimensions is obtained from the
light-cone parametrized Nambu-Goto superstring in (2+1)-dimensions. The lineal
model is completely integrable and can be formulated neatly using Riemann
coordinates. Infinite towers of conserved charges and supercharges are
exhibited. They form irreducible representations of a dynamical (hidden)
SO(2,1) symmetry group.

categories: physics.flu-dyn hep-th math-ph math.MP nlin.SI


title:
Superparticles from the Initial Universe and deduction of the Fine
  Structure Constant and Uncertainty Principle directly from the Gravitation
  Theory

abstract:
  In a previous work it was shown that the gravitational and inertial masses
are correlated by an adimensional factor, which depends on the incident
radiation upon the particle. It was also shown that there is a direct
correlation between the radiation absorbed by the particle and its
gravitational mass, independently of the inertial mass. This finding has
fundamental consequences to Unified Field Theory and Quantum Cosmology. Only in
the absence of electromagnetic radiation the mentioned factor becomes equal to
one. On the other hand, in specific electromagnetic conditions, it can be
reduced, nullified or made negative. This means that there is the possibility
of the gravitational masses can be reduced, nullified and made negative by
means of electromagnetic radiation. This unexpected theoretical result was
recently confirmed by an experiment (gr-qc/0005107). A fundamental consequence
of the mentioned correlation is that , in specific ultra-high energy
conditions, the gravitational and electromagnetic fields can be described by
the same Hamiltonian , i.e., in these circumstances, they are unified. Such
conditions can have occurred inclusive in the Initial Universe , before the
first spontaneous breaking of symmetry. Taking as base this discovery, and
starting from the gravitational mass of superparticles from the Initial
Universe we show here that it is possible to deduce the reciprocal fine
structure constant and the uncertainty principle directly from the Gravitation
Theory(Unified Theory).


title: Phenomenological Theory of Survival

abstract:
  Theoretical analysis proves that human survivability is dominated by an
unusual physical, rather than biological, mechanism, which yields an exact law.
The law agrees with all experimental data, but, contrary to existing theories,
it is the same for an entire species, i.e., it is independent of the
population, its phenotypes, environment and history. The law implies that the
survivability changes with environment via phase transitions, which are
simultaneous for all generations. They allow for a rapid (within few percent of
the life span) and significant increase in the life expectancy even above its
value at a much earlier age.


title: Variational calculation of positronium-helium-atom scattering length

abstract:
  We present a variational basis-set calculational scheme for elastic
scattering of positronium atom by helium atom in S wave and apply it to the
calculation of the scattering length. Highly correlated trial functions with
appropriate symmetry are used in this calculation. We report numerical result
for the scattering length in atomic unit: $(1.0\pm 0.1)a_0$. This corresponds
to a zero-energy elastic cross section of $(4.0\pm 0.8)\pi a_0^2$.


title: Iwasawa Effects in Multi-layer Optics

abstract:
  There are many two-by-two matrices in layer optics. It is shown that they can
be formulated in terms of a three-parameter group whose algebraic property is
the same as the group of Lorentz transformations in a space with two space-like
and one time-like dimensions, or the $Sp(2)$ group which is a standard
theoretical tool in optics. Among the interesting mathematical properties of
this group, the Iwasawa decomposition drastically simplifies the matrix algebra
under certain conditions, and leads to a concise expression for the S-matrix
for transmitted and reflected rays. It is shown that the Iwasawa effect can be
observed in multi-layer optics, and a sample calculation of the S-matrix is
given.


title: Spectrum of light scattering from an extended atomic wave packet

abstract:
  The spectrum of the light scattered from an extended atomic wave packet is
calculated. For a wave packet consisting of two spatially separated peaks
moving on parallel trajectories, the spectrum contains Ramsey-like fringes that
are sensitive to the phase difference between the two components of the wave
packet. Using this technique, one can establish the mutual coherence of the two
components of the wave packet without recombining them.


title:
Do the Laws of Nature and Physics Agree About What is Allowed and
  Forbidden?

abstract:
  There are countless examples in the history of science that not only were the
laws of physics often incomplete and more limited in their domain of validity
than was realized, but at times they missed the mark completely. Despite this,
our collective memory is often short on such matters, focusing on present
triumphs and quickly forgetting past failures. This makes us less tolerant to
that which challenges present orthodoxy. It may be of value to recall such past
deficiences as well as present shortcomings, particularly since science may
always be encumbered with such limitations. We can avoid serious pitfalls if we
let the past serve as a guide to the future. Subjects covered will include
Godel's theorem, superconductivity, zero-point energy, the quantum and
classical Aharonov-Bohm and similar effects, theories of general relativity,
Mach's principle, black hole radiation, ball lightning, and the universe(s).


title:
Hydrodynamical interaction between a shock wave and a cloud. One
  dimensional approach

abstract:
  The collision of a plane parallel shock wave with a plane parallel cloud of
uniform density is analysed for the case in which magnetic fields and radiative
losses are not considered. General analytic solutions are discussed for the
case in which the density of the cloud is greater than that of the surrounding
environment. This problem generalises one of the classical problems in gas
dynamics: the collision between a shock wave and a solid wall.


title: The Light Scattering and Fast Mie Algorithm

abstract:
  The main topics of this paper is to shown a Fast Mie Algorithm FMA as the
best way to use the Mie scattering theory for cross section calculation. This
fast algorithm used recursion for summing a long timed sum of cylindrical
functions.


title:
Ray-Tracing studies in a perturbed atmosphere: I- The initial value
  problem

abstract:
  We report the development of a new ray-tracing simulation tool having the
potential of the full characterization of a radio link through the accurate
study of the propagation path of the signal from the transmitting to the
receiving antennas across a perturbed atmosphere. The ray-tracing equations are
solved, with controlled accuracy, in three dimensions (3D) and the propagation
characteristics are obtained using various refractive index models. The
launching of the rays, the atmospheric medium and its disturbances are
characterized in 3D. The novelty in the approach stems from the use of special
numerical techniques dealing with so called stiff differential equations
without which no solution of the ray-tracing equations is possible. Starting
with a given launching angle, the solution consists of the ray trajectory, the
propagation time information at each point of the path, the beam spreading, the
transmitted (resp. received) power taking account of the radiation pattern and
orientation of the antennas and finally, the polarization state of the beam.
Some previously known results are presented for comparative purposes and new
results are presented as well as some of the capabilities of the software.


title:
Poynting vector, energy density and energy velocity in anomalous
  dispersion medium

abstract:
  The Poynting vector, energy density and energy velocity of light pulses
propagating in anomalous dispersion medium (used in WKD-like experiments) are
calculated. Results show that a negative energy density in the medium
propagates along opposite of incident direction with such a velocity similar to
the negative group velocity while the direction of the Poynting vector is
positive. In other words, one might say that a positive energy density in the
medium would propagate along the positive direction with a speed having
approximately the absolute valueof the group velocity. We further point out
that neither energy velocity nor group velocity is a good concept to describe
the propagation process of light pulse inside the medium in WKD experiment
owing to the strong accumulation and dissipation effects.


title: Verifying the learning process in Physics

abstract:
  The paper describes an automated evaluation system for the learning of
general Physics. The system whose name is Test on Line (ToL) is based on a
questions bank from which an appropriate software generates individual
multi-issue questionnaires to be submitted through the web. ToL has been
extensively experimented during three years and is presently in use for basic
Physics courses at the Engineering Faculties of the Turin Politecnico. The
results of the experimentation and use are presented and discussed. Cumulating
data allows for an optimization of the internal partitions of the questions
bank and of the selection criteria for the generation of the questionnaires.
The instrument proved to be useful and reliable and could become the core of an
agreed common standard for physics education at university level.


title: Information-theoretic approach to the study of control systems

abstract:
  We propose an information-theoretic framework for analyzing control systems
based on the close relationship of controllers to communication channels. A
communication channel takes an input state and transforms it into an output
state. A controller, similarly, takes the initial state of a system to be
controlled and transforms it into a target state. In this sense, a controller
can be thought of as an actuation channel that acts on inputs to produce
desired outputs. In this transformation process, two different control
strategies can be adopted: (i) the controller applies an actuation dynamics
that is independent of the state of the system to be controlled (open-loop
control); or (ii) the controller enacts an actuation dynamics that is based on
some information about the state of the controlled system (closed-loop
control). Using this communication channel model of control, we provide
necessary and sufficient conditions for a system to be perfectly controllable
and perfectly observable in terms of information and entropy. In addition, we
derive a quantitative trade-off between the amount of information gathered by a
closed-loop controller and its relative performance advantage over an open-loop
controller in stabilizing a system. This work supplements earlier results [H.
Touchette, S. Lloyd, Phys. Rev. Lett. 84, 1156 (2000)] by providing new
derivations of the advantage afforded by closed-loop control and by proposing
an information-based optimality criterion for control systems. New applications
of this approach pertaining to proportional controllers, and the control of
chaotic maps are also presented.


title: Unified Theory of Field with Modul of Squared Curvature as Lagrangian

abstract:
  The 4-D theory with connection components Gamma^k_{mn} as field variables and
module of squared curvature |R^k_{lmn}R^{lmn}_k| as Lagrangian is described.
The Maxwell equations, the Lorentz condition and the gravity field equation,
that agrees with Newton's theory, result from equations of motion.


title:
Are electromagnetic phenomena derivable from extended Einstein
  equations?

abstract:
  A new term describing interactions between charge and potentials may be added
to the right hand side of the Einstein equations. In the proposed term an
additional tensor has been introduced containing a charge density, analogous to
the energy-momentum tensor containing a mass density. (The contribution of the
electromagnetic fields has not been considered in this work.) The metric
components in the new equations may contain charge and mass contributions. In
the special relativistic case a set of four vacuum Maxwell equations is
obtained from the new equations containing a special relativistic charge
density. A related result was recently found by Jefimenko from a special
relativistic transformation. Moreover, from the postulated equations the usual
special relativistic electric energy and Lorentz force can be calculated, when
the approximated electromagnetic metric is used. In the non-relativistic case
the usual Maxwell equations with rest charge density are obtained. In the
presence of a static gravitational field a set of four Maxwell equations is
obtained applying in the general relativistic case. From these equations the
generally accepted isotropic velocity of light can be deduced. In addition,
calculated generalized Maxwell equations show that vacuum permittivity and
permeability may differ from unity value in the presence of a big charge Q or a
big mass M.


title:
Measurement of the Resonant $d\mu t$ Molecular Formation Rate in Solid
  HD

abstract:
  Measurements of muon-catalyzed dt fusion ($d\mu t \to ^4He+n+\mu^-$) in solid
HD have been performed. The theory describing the energy dependent resonant
molecular formation rate for the reaction $\mu t$ + HD $\to [(d\mu t)pee]^*$ is
compared to experimental results in a pure solid HD target. Constraints on the
rates are inferred through the use of a Monte Carlo model developed
specifically for the experiment. From the time-of- flight analysis of fusion
events in 16 and 37 $\mu g\cdot cm^{-2}$ targets, an average formation rate
consistent with 0.897$\pm$(0.046)$_{stat}\pm$ (0.166)$_{syst}$ times the
theoretical prediction was obtained.


title:
Nonlinear resonance reflection from and transmission through a dense
  glassy system built up of oriented linear Frenkel chains: two-level models

abstract:
  A theoretical study of the resonance optical response of assemblies of
oriented short (as compared to an optical wavelength) linear Frenkel chains is
carried out using a two-level model. We show that both transmittivity and
reflectivity of the film may behave in a bistable fashion and analyze how the
effects found depend on the film thickness and on the inhomogeneous width of
the exciton optical transition.


title:
Conditions for Soliton-Like Wave Propagation in Pockels and
  Photorefractive Media

abstract:
  We study the conditions for soliton-like wave propagation in the
Photorefractive (PR) and electro-optic (i.e., Pockels) material, by using
Nonlinear Schrodinger (NLS) equation. The complete NLS equation is solved
analytically and numerically by transforming it into the phase space. Our
results clearly show the existence of both the dark and bright solitary
solutions for the PR medium. Interestingly, however, we find only one bright
solitary solution in the Pockels case and there is no evidence of any dark
solitary solution.


title: On the nature of spinor Bose-Einstein condensates in rubidium

abstract:
  We perform detailed close-coupling calculations for the rubidium isotopes
85Rb and 87Rb to ascertain the nature of their spinor Bose-Einstein
condensates. These calculations predict that the spinor condensate for the
spin-1 boson 87Rb has a ferromagnetic nature. The spinor condensates for the
spin-2 bosons 85Rb and 87Rb, however, are both predicted to be polar. The
nature of a spin-1 condensate hinges critically on the sign of the difference
between the s-wave scattering lengths for total spin 0 and 2 while the nature
of a spin-2 condensate depends on the values of the differences between s-wave
scattering lengths for the total spin 0, 2 and 4. These scattering lengths were
extracted previously and found to have overlapping uncertainties for all three
cases, thus leaving the nature of the spinor condensates ambiguous. The present
study exploits a refined uncertainty analysis of the scattering lengths based
on recently improved result from experimental work by Roberts et al., which
permits us to extract an unambiguous result for the nature of the ground state
spinor condensates.


title: Addendum to "Coulomb Interaction Does Not Spread Instantaneously"

abstract:
  We describe the results of experimental research by configurations changed
with respect to the original experimental configuration [1]. In this way it is
demonstrated that the basic part of the signal registered is due to the Coulomb
electric field and does not originate from the transversal electromagnetic
wave.


title:
Geometric and Statistical Properties of the Mean-Field HP Model, the LS
  Model and Real Protein Sequences

abstract:
  Lattice models, for their coarse-grained nature, are best suited for the
study of the ``designability problem'', the phenomenon in which most of the
about 16,000 proteins of known structure have their native conformations
concentrated in a relatively small number of about 500 topological classes of
conformations. Here it is shown that on a lattice the most highly designable
simulated protein structures are those that have the largest number of
surface-core switchbacks. A combination of physical, mathematical and
biological reasons that causes the phenomenon is given. By comparing the most
foldable model peptides with protein sequences in the Protein Data Bank, it is
shown that whereas different models may yield similar designabilities,
predicted foldable peptides will simulate natural proteins only when the model
incorporates the correct physics and biology, in this case if the main folding
force arises from the differing hydrophobicity of the residues, but does not
originate, say, from the steric hindrance effect caused by the differing sizes
of the residues.


title: A Note on Transfinite M Theory and the Fine Structure Constant

abstract:
  In this short note, using notions from $p$-Adic QFT and $p$-branes, we derive
the transfinite M $theoretical$ corrections $(\alpha_M)^{-1} = 100 + 61 \phi$
to El Naschie's inverse fine structure constant value $(\alpha_{HS})^{-1}= 100
+ 60\phi$ which was based on a transfinite Heterotic string theory ormalism .
$\phi$ is the Golden Mean $0.6180339...$. Our results are consistent with
recent Astrophysical observations of he Boomerang and Maxima experiments, with
previous results based on the four dimensional gravitational conformal anomaly
calculations and with an enhanced hierarchy of the number of lines on Del Pezzo
surfaces.


title:
Great Belt of Megalithic Observatories and Problem of History of the
  Pole of the World

abstract:
  The problem of localization of megalithic memorials on the Earth surface is
investigated. It is pointed on existence of Great Belt of megalithic
observatories - of con- centration of astronomically significant objects near
geographical latitude 51 grad. N. The latent fundamental (and astronomical)
sense is discussed of this phenomenon- the tendency to functional and
architectural simplisity, to simmetry of megali- thic observatories (in view of
the Symmetric Mandale. It is pointed on possibility of existence of other
stretching concentrations-of clusters of megalithic observatories (the Great
Belts) in connection with other fixed position of the Poles of the World (of
the Earth rotation) in past


title:
Physical Consequences of a Momenta-Transfering Particle Theory of
  Induced Gravity and New Measurements Indicating Variation from Inverse Square
  Law at Length Scale of .1 mm: Statistical Time Properties of Gravitational
  Interaction and Analysis Thereof

abstract:
  This work presents physical consequences of our theory of induced gravity
(Ref.1) regarding: 1) the requirement to consider shape and materials
properties when calculating graviton cross section collision area; 2) use of
Special Relativity; 3) implications regarding the shape of cosmos; 4)
comparison to explanations using General Relativity; 5) properties of black
holes; 6) relationship to the strong force and the theorized Higgs boson; 7)
the possible origin of magnetic attraction; 8) new measurements showing
variation from gravitational inverse square behavior at length scales of 0.1 mm
and relationship to the Cosmological constant, and proof of the statistical
time properties of the gravitational interaction.


title: Relativistic Mechanics of Continuous Media

abstract:
  In this work we study the relativistic mechanics of continuous media on a
fundamental level using a manifestly covariant proper time procedure. We
formulate equations of motion and continuity (and constitutive equations) that
are the starting point for any calculations regarding continuous media. In the
force free limit, the standard relativistic equations are regained, so that
these equations can be regarded as a generalization of the standard procedure.
In the case of an inviscid fluid we derive an analogue of the Bernoulli
equations. For irrotational flow we prove that the velocity field can be
derived from a potential. If, in addition, the fluid is incompressible, the
potential must obey the d'Alembert equation, and thus the problem is reduced to
solving the d'Alembert equation with specific boundary conditions (in both
space and time). The solutions indicate the existence of light velocity sound
waves in an incompressible fluid (a result known from previous literature
[19]). Relaxing the constraints and allowing the fluid to become linearly
compressible, one can derive a wave equation from which the sound velosity can
again be computed. For a stationary background flow, it has been demonstrated
that the sound velocity attains its corrrect values for the incompressible and
non-relatvistic limits. Finally, viscosity is introduced, bulk and shear
viscosity constants are defined, and we formulate equations for the motion of a
viscous fluid.

categories: physics.flu-dyn math-ph math.MP physics.acc-ph physics.class-ph


title:
Information preserved guided scan pixel difference coding for medical
  images

abstract:
  This paper analyzes the information content of medical images, with 3-D MRI
images as an example, in terms of information entropy. The results of the
analysis justify the use of Pixel Difference Coding for preserving all
information contained in the original pictures, lossless coding in other words.
The experimental results also indicate that the compression ratio CR=2:1 can be
achieved under the lossless constraints. A pratical implementation of Pixel
Difference Coding which allows interactive retrieval of local ROI (Region of
Interest), while maintaining the near low bound information entropy, is
discussed.


title:
The Equivalence Principle and gravitational and inertial mass relation
  of classical charged particle

abstract:
  We show that the locally constant force necessary to get a stable hyperbolic
motion regime for classical charged particles, actually, is a subtle
combination of an applied external force and the radiation reaction force. It
suggests, as the Equivalence Principle is valid, that the gravitational mass of
charged particle should be slight greater than its inertial mass. However, an
interesting new feature emerges from the unexpected behavior of the
gravitational and inertial mass relation at very strong gravitational field,
just reachable at the early stage of the universe or, perhaps, near massive
black holes, with a divergence that introduces a critical field value. It signs
that the Equivalence Principle should not be valid near to this critical field,
which certainly coincides where the quantum effects turns to be relevant.


title: Simulation of Beam-Beam Effects in $e^+e^-$ Storage Rings

abstract:
  The beam-beam effects of the PEP-II as an asymmetric collider are studied
with strong-strong simulations using a newly developed particle-in-cell (PIC)
code. The simulated luminosity agrees with the measured one within 10% in a
large range of the beam currents. The spectra of coherent dipole oscillation
are simulated with and without the transparency symmetry. The simulated tune
shift of the coherent $\pi$ mode agrees with the linearized Vlasov theory even
at large beam-beam parameters. The Poicare map of coherent dipole is used to
identify the beam-beam resonances.


title: Energy Distribution in Earthquakes: A Non-Extensive Approach

abstract:
  By using the maximum entropy principle with Tsallis entropy and under the
assumption that the gouge plays an active role in the triggering of
earthquakes, we obtain a functional dependence for energy distribution function
for earthquakes which fits very well with observations in the region of small
energies. This distribution function is related to the size distribution
function of fragments in the gouge.


title:
Large deformation of spherical vesicle studied by perturbation theory
  and Surface evolver

abstract:
  With tangent angle perturbation approach the axial symmetry deformation of a
spherical vesicle in large under the pressure changes is studied by the
elasticity theory of Helfrich spontaneous curvature model.Three main results in
axial symmetry shape: biconcave shape, peanut shape, and one type of myelin are
obtained. These axial symmetry morphology deformations are in agreement with
those observed in lipsome experiments by dark-field light microscopy [Hotani,
J. Mol. Biol. 178, (1984) 113] and in the red blood cell with two thin
filaments (myelin) observed in living state (see, Bessis, Living Blood Cells
and Their Ultrastructure, Springer-Verlag, 1973). Furthermore, the biconcave
shape and peanut shape can be simulated with the help of a powerful software,
Surface Evolver [Brakke, Exp. Math. 1, 141 (1992) 141], in which the
spontaneous curvature can be easy taken into account.


title:
Quasi-chemical Theory for the Statistical Thermodynamics of the Hard
  Sphere Fluid

abstract:
  We develop a quasi-chemical theory for the study of packing thermodynamics in
dense liquids. The situation of hard-core interactions is addressed by
considering the binding of solvent molecules to a precisely defined `cavity' in
order to assess the probability that the `cavity' is entirely evacuated. The
primitive quasi-chemical approximation corresponds to a extension of the
Poisson distribution used as a default model in an information theory approach.
This primitive quasi-chemical theory is in good qualitative agreement with the
observations for the hard sphere fluid of occupancy distributions that are
central to quasi-chemical theories but begins to be quantitatively erroneous
for the equation of state in the dense liquid regime of $\rho d^3>$0.6. How the
quasi-chemical approach can be iterated to treat correlation effects is
addressed. Consideration of neglected correlation effects leads to a simple
model for the form of those contributions neglected by the primitive
quasi-chemical approximation. These considerations, supported by simulation
observations, identify a `break away' phenomena that requires special
thermodynamic consideration for the zero (0) occupancy case as distinct from
the rest of the distribution. A empirical treatment leads to a one parameter
model occupancy distribution that accurately fits the hard sphere equation of
state and observed distributions.


title: New stopping criteria for segmenting DNA sequences

abstract:
  We propose a solution on the stopping criterion in segmenting inhomogeneous
DNA sequences with complex statistical patterns. This new stopping criterion is
based on Bayesian Information Criterion (BIC) in the model selection framework.
When this stopping criterion is applied to a left telomere sequence of yeast
Saccharomyces cerevisiae and the complete genome sequence of bacterium
Escherichia coli, borders of biologically meaningful units were identified
(e.g. subtelomeric units, replication origin, and replication terminus), and a
more reasonable number of domains was obtained. We also introduce a measure
called segmentation strength which can be used to control the delineation of
large domains. The relationship between the average domain size and the
threshold of segmentation strength is determined for several genome sequences.


title: DNA Segmentation as A Model Selection Process

abstract:
  Previous divide-and-conquer segmentation analyses of DNA sequences do not
provide a satisfactory stopping criterion for the recursion. This paper
proposes that segmentation be considered as a model selection process. Using
the tools in model selection, a limit for the stopping criterion on the relaxed
end can be determined. The Bayesian information criterion, in particular,
provides a much more stringent stopping criterion than what is currently used.
Such a stringent criterion can be used to delineate larger DNA domains. A
relationship between the stopping criterion and the average domain size is
empirically determined, which may aid in the determination of isochore borders.


title:
Zipf's Law in Importance of Genes for Cancer Classification Using
  Microarray Data

abstract:
  Microarray data consists of mRNA expression levels of thousands of genes
under certain conditions. A difference in the expression level of a gene at two
different conditions/phenotypes, such as cancerous versus non-cancerous, one
subtype of cancer versus another, before versus after a drug treatment, is
indicative of the relevance of that gene to the difference of the high-level
phenotype. Each gene can be ranked by its ability to distinguish the two
conditions. We study how the single-gene classification ability decreases with
its rank (a Zipf's plot). Power-law function in the Zipf's plot is observed for
the four microarray datasets obtained from various cancer studies. This
power-law behavior in the Zipf's plot is reminiscent of similar power-law
curves in other natural and social phenomena (Zipf's law). However, due to our
choice of the measure of importance in classification ability, i.e., the
maximized likelihood in a logistic regression, the exponent of the power-law
function is a function of the sample size, instead of a fixed value close to 1
for a typical example of Zipf's law. The presence of this power-law behavior is
important for deciding the number of genes to be used for a discriminant
microarray data analysis.


title: How Many Genes Are Needed for a Discriminant Microarray Data Analysis ?

abstract:
  The analysis of the leukemia data from Whitehead/MIT group is a discriminant
analysis (also called a supervised learning). Among thousands of genes whose
expression levels are measured, not all are needed for discriminant analysis: a
gene may either not contribute to the separation of two types of
tissues/cancers, or it may be redundant because it is highly correlated with
other genes. There are two theoretical frameworks in which variable selection
(or gene selection in our case) can be addressed. The first is model selection,
and the second is model averaging. We have carried out model selection using
Akaike information criterion and Bayesian information criterion with logistic
regression (discrimination, prediction, or classification) to determine the
number of genes that provide the best model. These model selection criteria set
upper limits of 22-25 and 12-13 genes for this data set with 38 samples, and
the best model consists of only one (no.4847, zyxin) or two genes. We have also
carried out model averaging over the best single-gene logistic predictors using
three different weights: maximized likelihood, prediction rate on training set,
and equal weight. We have observed that the performance of most of these
weighted predictors on the testing set is gradually reduced as more genes are
included, but a clear cutoff that separates good and bad prediction performance
is not found.


title: A Note on Symplectic Algorithms

abstract:
  We present the symplectic algorithm in the Lagrangian formalism for the
Hamiltonian systems by virtue of the noncommutative differential calculus with
respect to the discrete time and the Euler--Lagrange cohomological concepts. We
also show that the trapezoidal integrator is symplectic in certain sense.


title:
Diffraction-free and dispersion-free pulsed beam propagation in
  dispersive media

abstract:
  Pulsed Bessel beams of light propagating in free-space experience diffraction
effects that resemble those of anomalous dispersion on pulse propagation. It is
then shown that a pulsed Bessel beam in a normally dispersive material can
remain diffraction- and dispersion-free due to mutual cancellation of
diffraction and group velocity dispersion. The size of the Bessel transversal
profile for localized transmission is determined by the dispersive properties
of the material at the pulse carrier frequency.


title: A Multisection Broadband Impedance Transforming Branch-Line Hybrid

abstract:
  Measurements and design equations for a two section impedance transforming
hybrid suitable for MMIC applications and a new method of synthesis for
multisection branch-line hybrids are reported. The synthesis method allows the
response to be specified either of Butterworth or Chebyshev type. Both
symmetric (with equal input and output impedances) and non-symmetric (impedance
transforming) designs are feasible. Starting from a given number of sections,
type of response, and impedance transformation ratio and for a specified
midband coupling, power division ratio, isolation or directivity ripple
bandwidth, the set of constants needed for the evaluation of the reflection
coefficient response is first calculated. The latter is used to define a
driving point impedance of the circuit, synthesize it and obtain the branch
line immittances with the use of the concept of double length unit elements
(DLUE). The experimental results obtained with microstrip hybrids constructed
to test the validity of the brute force optimization and the synthesized
designs show very close agreement with the computed responses.


title: The HERMES Dual-Radiator Ring Imaging Cerenkov Detector

abstract:
  The construction and use of a dual radiator Ring Imaging Cerenkov(RICH)
detector is described. This instrument was developed for the HERMES experiment
at DESY which emphasizes measurements of semi-inclusive deep-inelastic
scattering. It provides particle identification for pions, kaons, and protons
in the momentum range from 2 to 15 GeV, which is essential to these studies.
The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall
of silica aerogel tiles. The use of aerogel in a RICH detector has only
recently become possible with the development of clear, large homogeneous and
hydrophobic aerogel. A lightweight mirror was constructed using a newly
perfected technique to make resin-coated carbon-fiber surfaces of optical
quality. The photon detector consists of 1934 photomultiplier tubes for each
detector half, held in a soft steel matrix to provide shielding against the
residual field of the main spectrometer magnet.


title: Prediction of stable walking for a toy that cannot stand

abstract:
  Previous experiments [M. J. Coleman and A. Ruina, Phys. Rev. Lett. 80, 3658
(1998)] showed that a gravity-powered toy with no control and which has no
statically stable near-standing configurations can walk stably. We show here
that a simple rigid-body statically-unstable mathematical model based loosely
on the physical toy can predict stable limit-cycle walking motions. These
calculations add to the repertoire of rigid-body mechanism behaviors as well as
further implicating passive-dynamics as a possible contributor to stability of
animal motions.


title:
Exact solutions of the Boeder differential equation for macromolecular
  orientations in a flowing liquid

abstract:
  The Boeder differential equation is solved in this work over a wide range of
$\alpha$, yielding the probability density functions (PDF), that describe the
average orientations of rod-like macromolecules in a flowing liquid. The
quantity $\alpha$ is the ratio of the hydrodynamic shear rate to the rotational
diffusion coefficient. It characterises the coupling of the motion of the
macromolecules in the hydrodynamic flow to their thermal diffusion. Previous
analytical work is limited to approximate solutions for small values of
$\alpha$. Special analytical as well as numerical methods are developed in the
present work in order to calculate accurately the PDF for a range of $\alpha$
covering several orders of magnitude, $10^{-6} \le \alpha \le 10^{8}$. The
mathematical nature of the differential equation is revealed as a singular
perturbation problem when $\alpha$ becomes large. Scaling results are obtained
over the differential equation for $\alpha \ge 10^{3}$. Monte Carlo Brownian
simulations are also constructed and shown to agree with the numerical
solutions of the differential equation in the bulk of the flowing liquid, for
an extensive range of $\alpha$. This confirms the robustness of the developed
analytical and numerical methods.


title:
Quasiperiodic waves at the onset of zero Prandtl number convection with
  rotation

abstract:
  We show the possibility of quasiperiodic waves at the onset of thermal
convection in a thin horizontal layer of slowly rotating zero-Prandtl number
Boussinesq fluid confined between stress-free conducting boundaries. Two
independent frequencies emerge due to an interaction between a stationary
instability and a self-tuned wavy instability in presence of coriolis force, if
Taylor number is raised above a critical value. Constructing a dynamical system
for the hydrodynamical problem, the competition between the interacting
instabilities is analyzed. The forward bifurcation from the conductive state is
self-tuned.


title: Resonances in positronium-rubidium and positronium-cesium scattering

abstract:
  Scattering of ortho positronium (Ps) by cesium and rubidium atoms has been
investigated employing a three-Ps-state coupled-channel model with Ps(1s,2s,2p)
states using a time-reversal-symmetric regularized electron-exchange model
potential. We find a narrow S-wave singlet resonance at 5.057 eV of width 0.003
eV in the Ps-Rb system and at 5.067 eV of width 0.003 eV in the Ps-Cs system.
Singlet P-wave resonances in both systems are found at 5.3 eV of width 0.4 eV.
Singlet D-wave structures are found at 5.4 eV in both systems. The pronounced
P- and D-wave resonances in these systems lead to easily detectable local
minima in the low-energy elastic cross sections. We also report results for
elastic and Ps-excitation cross sections for Ps scattering by Rb and Cs.


title: Cooling atoms in an optical trap by selective parametric excitation

abstract:
  We demonstrate the possibility of energy-selective removal of cold atoms from
a tight optical trap by means of parametric excitation of the trap vibrational
modes. Taking advantage of the anharmonicity of the trap potential, we
selectively remove the most energetic trapped atoms or excite those at the
bottom of the trap by tuning the parametric modulation frequency. This process,
which had been previously identified as a possible source of heating, also
appears to be a robust way for forcing evaporative cooling in anharmonic traps.


title:
About Small Corrections to General Relativity: Gravitational
  Acceleration Depands of the Accelereted Bodies Masses

abstract:
  In the frame of multifractal theory of time and space (in this model our
universe is consisting of real time and space fields and is the multifractal
universe) in the works [1]-[16] some problems were analyzed: how the fractional
dimensions of real fields of time and space influence on behavior of different
physical phenomena. In this paper it is shown that in the multifractal theory
of time and space the corrections of general relativity to Newton gravitational
forces are explaining very simple in Newton approach. It is shown also that
there is dependence (though very small) of bodies gravitational acceleration
from their masses, so the principle of equivalence in multifractal universe is
not absolute and it is only a very good approach. For perihelion of Mercury
rotation the correction to known results of Einstein relativity is consi-
dered. CONTENTS: 1. Introduction; 2. Newton Equations in the Multifractal
Universe; 3. Is Gravitational Acceleration Depends of the Mass of the
Accelerated Body? 4. Experimental Checking; 5. Conclusions


title:
Newton Equations May be Treated as Diffusion Equations in the Real Time
  and Space Fields of Multifractal Universe (Masses are Diffusion Coefficients
  of Diffusion-like Equations)

abstract:
  In thirties years of last century Dirac proposed to treat Schrodinger
equation as the equation of diffusion with imaginary diffusion coefficient. In
the frame of multifractal theory of time and space (in this model our the
multifractal universe is consisting of real time and space fields) in the works
[1]-[16] was analyzed how the fractional dimensions of real fields of time and
space influence on behavior of different physical phenomena. In this paper the
Newton equations of the multifractal universe (considered for the first time in
[1]-[3]) are generalized and is treated as the equations of diffusion with mass
of bodies (depending of fractional dimension of place, where these bodies
located) as a coefficient of diffusion. The realization of this point of view
for inhomogeneous time equations (the analogies of Newton equations) is carried
out too. The last leads to introducing of new sort of masses: the masses that
characterize the inertia of inhomogeneous time flows with space coordinates
changing. CONTENTS: 1. Introduction;2. Newton Equations in the Multifractal
Universe; 3. Generalized Newton Equations and Its Diffusion Interpretation; 4.
Generalized Inhomogeneous Time Equation and Its Diffusion Interpretation; 5.
Conclusions


title: Beam Measurements of a CLOUD (Cosmics Leaving OUtdoor Droplets) Chamber

abstract:
  A striking correlation has recently been observed between global cloud cover
and the flux of incident cosmic rays. The effect of natural variations in the
cosmic ray flux is large, causing estimated changes in the Earth's energy
radiation balance that are comparable to those attributed to greenhouse gases
from the burning of fossil fuels since the Industrial Revolution. However a
direct link between cosmic rays and cloud formation has not been unambiguously
established. We therefore propose to experimentally measure cloud (water
droplet) formation under controlled conditions in a test beam at CERN with a
CLOUD chamber, duplicating the conditions prevailing in the troposphere. These
data, which have never been previously obtained, will allow a detailed
understanding of the possible effects of cosmic rays on clouds and confirm, or
otherwise, a direct link between cosmic rays, global cloud cover and the
Earth's climate. The measurements will, in turn, allow more reliable
calculations to be made of the residual effect on global temperatures of the
burning of fossil fuels, an issue of profound importance to society.
Furthermore, light radio-isotope records indicate a correlation has existed
between global climate and the cosmic ray flux extending back over the present
inter-glacial and perhaps earlier. This suggests it may eventually become
possible to make long-term (10-1,000 year) predictions of changes in the
Earth's climate, provided a deeper understanding can be achieved of the
``geomagnetic climate'' of the Sun and Earth that modulates the cosmic-ray
flux.

categories: physics.ao-ph hep-ex physics.geo-ph physics.space-ph


title: Bifurcation of gap solitons through catastrophe theory

abstract:
  In the theory of optical gap solitons, slowly-moving finite-amplitude
Lorentzian solutions are found to mediate the transition from bright to
coexistent dark-antidark solitary wave pairs when the laser frequency is
detuned out of the proper edge of a dynamical photonic bandgap. Catastrophe
theory is applied to give a geometrical description of this strongly
asymmetrical 'morphing' process.


title: Coherent control of superfluidity in a Fermi gas of atoms

abstract:
  We theoretically examine photoassociation of a two-component Fermi degenerate
gas, focusing on light-induced atom-atom interactions as a means to raise the
critical temperature of the BCS transition to a superfluid state. As it stands,
photoassociation-induced superfluidity is limited by spontaneous decay to
experimentally inconvenient light intensities [Mackie et al., Opt. Express 8,
118 (2000)]. We therefore propose to use coherent control in photoassociation
to a pair of molecular levels to cancel spontaneous emission, whereby the BCS
transition should occur within reach of current experimental techniques.

categories: physics.atom-ph cond-mat.soft cond-mat.supr-con physics.chem-ph quant-ph


title: Status Report and Future Plans for the PEP-II B Factory

abstract:
  The PEP-II B Factory at SLAC has been in operation with the BABAR detector
since the summer of 1999. The peak currents and luminosity steadily increased
through the end of the 2000 run on October 31. By that time, 0.75 A of
electrons (the design current) routinely collided with 1.4 A of positrons in
657 bunches, to give a peak luminosity of 2.6E33 cm^{-2} s^{-1}. We delivered
an integrated luminosity of up to 184/pb per day and 1033 per week; BABAR
logged a total of 25/fb. Three days of machine development at the end of the
run raised the peak luminosity to 3.29E33, exceeding the design goal of 3.0.
BABAR then logged data for an hour, starting with a peak of 3.20. Next, we
achieved the design value for positron current, 2.14 A, operating without
collisions. The major limitation has been growth in the size of the positron
beam in the low-energy ring (LER) due to electron clouds and multipacting.
Since the arcs benefit from antechambers and a TiN coating with low secondary
emission, our efforts have concentrated on the straights, where we added
solenoid windings. Each straight wound allowed higher LER current without
blow-up, and a consequent increase in luminosity. Measurements of the
bunch-by-bunch luminosity showed that the effect becomes significant by about
the tenth bunch in a train, but clears after a short gap. Careful control of
the fill pattern has thus been essential in raising luminosity. For the 2001
run, which began in February, we added a third LER RF station, to collide with
more LER current and more bunches, and also tried reducing beta_x* from 50 to
35 cm, with the goal of reaching a luminosity of 5E33 by year's end. In 2003,
we plan to add a fourth LER and sixth HER RF station to reach 1E34.


title: Parameters for a 30 GeV Undulator Test Facility in the FFTB/LCLS

abstract:
  The parameters for a 30 GeV test beam are outlined for use with an undulator
in the FFTB tunnel where the LCLS will eventually be housed. It is proposed to
use the SLAC linac and damping rings in their present mode of operation for PEP
II injection, where 30 GeV beams are also delivered at 10 Hz to the FFTB. High
peak currents are obtained with the addition of a second bunch compressor in
the linac. In order to minimize the synchrotron radiation induced emittance
growth in the bunch compressor it is necessary to locate the new bunch
compressor at the low-energy end of the linac, just after the damping rings.
The bunch compressor is a duplicate of the LCLS chicane-style bunch compressor.
This test beam would provide an exciting possibility to test LCLS undulator
sections and provide a unique high-brightness source of incoherent X-rays and
begin developing the LCLS experimental station. The facility will also act as a
much needed accelerator test bed for the production, diagnostics and tuning of
very short bunches in preparation for the LCLS after the photo injector is
commissioned.


title: Causality Principle

abstract:
  We advance a famous principle - causality principle - but under a new view.
This principle is a principium automatically leading to most fundamental laws
of the nature. It is the inner origin of variation, rules evolutionary
processes of things, and the answer of the quest for ultimate theories of the
Universe.


title: A speech for the luminiferous ether

abstract:
  There is no aberration of terrestrial sources, because the light-vector has
an inertial component. A new analysis of the Michelson Morley experiment shows:
Light propagates anisotropically relative to a moving system, dependent on the
velocity and the angle between the velocity and the direction of motion. The
two way (back and forth) velocity is isotropic, but also dependent on the
velocity of the frame. There is no Lorentz contraction. - A real ultrasonic
experiment shows: Also the propagation of sound follows the given general
conical section equation and an acoustical Michelson Morley experiment gives
the same zero result as the optical experiment in contrast to the school of
thought. - The theory of relativity is incorrect and the existence of a
luminiferous ether as a propagation medium and an absolute frame of reference
is again obvious. Some properties of the ether and a fundamental cause of the
dependency of the velocity on the mass and the frequency are presented.


title:
A study of the link between cosmic rays and clouds with a cloud chamber
  at the CERN PS

abstract:
  Recent satellite data have revealed a surprising correlation between galactic
cosmic ray (GCR) intensity and the fraction of the Earth covered by clouds. If
this correlation were to be established by a causal mechanism, it could provide
a crucial step in understanding the long-sought mechanism connecting solar and
climate variability. The Earth's climate seems to be remarkably sensitive to
solar activity, but variations of the Sun's electromagnetic radiation appear to
be too small to account for the observed climate variability. However, since
the GCR intensity is strongly modulated by the solar wind, a GCR-cloud link may
provide a sufficient amplifying mechanism. Moreover if this connection were to
be confirmed, it could have profound consequences for our understanding of the
solar contributions to the current global warming. The CLOUD (Cosmics Leaving
OUtdoor Droplets) project proposes to test experimentally the existence a link
between cosmic rays and cloud formation, and to understand the microphysical
mechanism. CLOUD plans to perform detailed laboratory measurements in a
particle beam at CERN, where all the parameters can be precisely controlled and
measured. The beam will pass through an expansion cloud chamber and a reactor
chamber where the atmosphere is to be duplicated by moist air charged with
selected aerosols and trace condensable vapours. An array of external detectors
and mass spectrometers is used to analyse the physical and chemical
characteristics of the aerosols and trace gases during beam exposure. Where
beam effects are found, the experiment will seek to evaluate their significance
in the atmosphere by incorporating them into aerosol and cloud models.


title:
Direct Determination of Harmonic and Inter-modulation distortions with
  an application to Single Mode Laser Diodes

abstract:
  Harmonic and Intermodulation distortions occur when a physical system is
excited with a single or several frequencies and when the relationship between
the input and output is non-linear. Working with non-linearities in the
Frequency domain is not straightforward specially when the relationship between
the input and output is not trivial. We outline the complete derivation of the
Harmonic and Intermodulation distortions from basic principles to a general
physical system. For illustration, the procedure is applied to the Single Mode
laser diode where the relationship of input to output is non-trivial. The
distortions terms are extracted directly from the Laser Diode rate equations
and the method is tested by comparison to many results cited in the literature.
This methodology is general enough to be applied to the extraction of
distortion terms to any desired order in many physical systems in a general and
systematic way.


title: Understanding multilayers from a geometrical viewpoint

abstract:
  We reelaborate on the basic properties of lossless multilayers. We show that
the transfer matrices for these multilayers have essentially the same algebraic
properties as the Lorentz group SO(2,1) in a (2+1)-dimensional spacetime, as
well as the group SL(2,R) underlying the structure of the ABCD law in
geometrical optics. By resorting to the Iwasawa decomposition, we represent the
action of any multilayer as the product of three matrices of simple
interpretation. This group-theoretical structure allows us to introduce
bilinear transformations in the complex plane. The concept of multilayer
transfer function naturally emerges and its corresponding properties in the
unit disc are studied. We show that the Iwasawa decomposition reflects at this
geometrical level in three simple actions that can be considered the basic
pieces for a deeper undestanding of the multilayer behavior. We use the method
to analyze in detail a simple practical example.


title:
Capture Velocity for a Magneto-Optical Trap in a Broad Range of Light
  Intensity

abstract:
  In a recent paper, we have used the dark-spot Zeeman tuned slowing technique
[Phys. Rev. A 62, 013404-1, (2000)] to measure the capture velocity as a
function of laser intensity for a sodium magneto optical trap. Due to technical
limitation we explored only the low light intensity regime, from 0 to 27
mW/cm^2. Now we complement that work measuring the capture velocity in a
broader range of light intensities (from 0 to 400 mW/cm^2). New features,
observed in this range, are important to understant the escape velocity
behavior, which has been intensively used in the interpretation of cold
collisions. In particular, we show in this brief report that the capture
velocity has a maximum as function of the trap laser intensity, which would
imply a minimum in the trap loss rates.


title:
A simple atomistic model for the simulation of the gel phase of lipid
  bilayers

abstract:
  In this paper we present the results of a large-scale numerical investigation
of structural properties of a model of cell membrane, simulated as a bilayer of
flexible molecules in vacuum. The study was performed by carrying out extensive
Molecular Dynamics simulations, in the (NVE) micro-canonical ensemble, of two
systems of different sizes (2x32 and 2x256 molecules), over a fairly large set
of temperatures and densities, using parallel platforms and more standard
serial computers. Depending on the dimension of the system, the dynamics was
followed for physical times that go from few hundred of picoseconds for the
largest system to 5--10 nanoseconds for the smallest one. We find that the
bilayer remains stable even in the absence of water and neglecting Coulomb
interactions in the whole range of temperatures and densities we have
investigated. The extension of the region of physical parameters that we have
explored has allowed us to study significant points in the phase diagram of the
bilayer and to expose marked structural changes as density and temperature are
varied, which are interpreted as the system passing from a crystal to a gel
phase.


title:
Improved Characterization of Elastic Scattering Near a Feshbach
  Resonance in 85Rb

abstract:
  We report extentions and corrections to the measurement of the Feshbach
resonance in 85Rb cold atom collisions reported earlier [J. L. Roberts et al.,
Phys. Rev. Lett. 81, 5109 (1998)]. In addition to a better determination of the
position of the resonance peak (154.9(4) gauss) and its width (11.0(4) gauss),
improvements in our techniques now allow the measurement of the absolute size
of the elastic scattering rate. This provides a new measure of the s-wave
scasttering length as a function of magnetic field near the Feshbach resonance
and contrains the Rb-Rb interaction potential.


title: Soliton model for proton conductivity in Langmuir films

abstract:
  A soliton model for proton conductivity in Langmuir films is presented. The
model contains three real scalar fields describing the hydrogen involved in the
conduction, the hydrophilic head of the Langmuir film, and the water. Soliton
solutions that describe proton motion along the hydrogen bonds are found. Under
compression of the film, the distance between the minima of the proton
potential and the strength of the hydrogen bonds between the film molecule and
the water are changed. Such changes increase the probability of soliton
creation. The model presented allows proton conductivity data in Langmuir films
to be explained.

categories: physics.chem-ph cond-mat.soft hep-ph hep-th


title: Anomalous self-similarity in two-dimensional turbulence

abstract:
  Our velocity measurements on a quasi-two-dimensional turbulent flow in a
rapidly rotating annulus yield an inverse cascade with E(k)~k^{-2} rather than
the expected E(k)~k^{-5/3}. The probability distribution functions for
longitudinal velocity differences, \delta_v(r)=v(x+r)-v(x), are self-similar
(scale independent) but strongly non-Gaussian, which suggests that the coherent
vortices play a significant role. The structure functions,
<[\delta_v(r)]^p>~r^{\zeta_p}, exhibit anomalous scaling: \zeta_p=p/2 rather
than \zeta_p=p/3 as in the 1941 Kolmogorov theory.


title:
Nonlinear Dynamics and Chaos: Applications for Prediction of Weather and
  Climate

abstract:
  Turbulence, namely, irregular fluctuations in space and time characterize
fluid flows in general and atmospheric flows in particular.The irregular,i.e.,
nonlinear space-time fluctuations on all scales contribute to the unpredictable
nature of both short-term weather and long-term climate.It is of importance to
quantify the total pattern of fluctuations for predictability studies. The
power spectra of temporal fluctuations are broadband and exhibit inverse power
law form with different slopes for different scale ranges. Inverse power-law
form for power spectra implies scaling (self similarity) for the scale range
over which the slope is constant. Atmospheric flows therefore exhibit multiple
scaling or multifractal structure.Standard meteorological theory cannot explain
satisfactorily the observed multifractal structure of atmospheric
flows.Selfsimilar spatial pattern implies long-range spatial correlations.
Atmospheric flows therefore exhibit long-range spatiotemporal correlations,
namely,self-organized criticality,signifying order underlying apparent chaos. A
recently developed non-deterministic cell dynamical system model for
atmospheric flows predicts the observed self-organized criticality as intrinsic
to quantumlike mechanics governing flow dynamics.The model predictions are in
agreement with continuous periodogram spectral analysis of meteorological data
sets.


title: The universal potential fluctuations

abstract:
  It is assumed the existence of the universal potential fluctuations valid for
all scales in the universe which follow the fractal law $\delta_U=(\Delta
r/r)^2$. The value of the universal potential fluctuations is determined from
the data on anisotropy of the cosmic microwave background on degree scales. It
is suggested to test the existence of the universal potential fluctuations in
the laboratory experiment.


title: Metastability of the Three-Dimensional Carbon Cluster Prismane C$_8$

abstract:
  Stability of recently predicted cage-like carbon cluster C$_8$ (prismane)
against its transformations to structures lying at lower energies is studied
theoretically. The smallest energy barrier inhibiting prismane transformation
is shown to be 0.44 eV, in qualitative agreement with the value of activation
energy for prismane decay calculated by molecular dynamics simulations. A
rather high value of the barrier suggests the possibility of experimental
observation of this cluster at ambient pressure.


title: The propagation of light and sound in moving systems

abstract:
  There is no aberration of terrestrial sources, because the lightvector has an
inertial component. A new analysis of the Michelson Morley experiment shows:
Light propagates anisotropically relative to a moving system, dependent on the
velocity and the angle between the velocity and the direction of motion. The
two way (back and forth) velocity is isotropic, but also dependent on the
velocity of the frame. There is no Lorentz contraction. - A real ultrasonic
experiment shows: Also the propagation of sound follows the given general
conical section equation and an acoustical Michelson Morley experiment gives
the same zero result as the optical experiment in contrast to the school of
thought. - The theory of relativity is incorrect and the existence of a
luminiferous ether as a propagation medium and an absolute frame of reference
is again obvious.


title:
Synchronization and multi-mode dynamics of mutually coupled
  semiconductor lasers

abstract:
  Dynamics of coupled semiconductor lasers is investigated by numerical
simulations. A realistic laser simulation engine is used to study the
synchronization and dynamical regime in two mutually coupled Fabry-Perot and/or
DFB lasers. Both, single- and multi-mode operation regimes are studied with
emphasis on the role of the multiple laser-cavity modes. Our findings indicate
that the two laser synchronize within each laser-cavity mode, while the
synchronization across different cavity modes is significantly weaker.


title:
Quenched Narrow-Line Laser Cooling of 40Ca to Near the Photon Recoil
  Limit

abstract:
  We present a cooling method that should be generally applicable to atoms with
narrow optical transitions. This technique uses velocity-selective pulses to
drive atoms towards a zero-velocity dark state and then quenches the excited
state to increase the cooling rate. We demonstrate this technique of quenched
narrow-line cooling by reducing the 1-D temperature of a sample of neutral 40Ca
atoms. We velocity select and cool with the 1S0(4s2) to 3P1(4s4p) 657 nm
intercombination line and quench with the 3P1(4s4p) to 1S0(4s5s)
intercombination line at 553 nm, which increases the cooling rate eight-fold.
Limited only by available quenching laser power, we have transferred 18 % of
the atoms from our initial 2 mK velocity distribution and achieved temperatures
as low as 4 microK, corresponding to a vrms of 2.8 cm/s or 2 recoils at 657 nm.
This cooling technique, which is closely related to Raman cooling, can be
extended to three dimensions.


title:
Molecular Dynamics Simulation of Sonoluminescence: Modeling, Algorithms
  and Simulation Results

abstract:
  Sonoluminescence is the phenomena of light emission from a collapsing gas
bubble in a liquid. Theoretical explanations of this extreme energy focusing
are controversial and difficult to validate experimentally. We propose to use
molecular dynamics simulations of the collapsing gas bubble to clarify the
energy focusing mechanism, and provide insight into the mechanism of light
emission.
  In this paper, we model the interior of a collapsing noble gas bubble as a
hard sphere gas driven by a spherical piston boundary moving according to the
Rayleigh-Plesset equation. We also include a simple treatment of ionization
effects in the gas at high temperatures. By using fast, tree-based algorithms,
we can exactly follow the dynamics of million particle systems during the
collapse. Our results clearly show strong energy focusing within the bubble,
including the formation of shocks, strong ionization, and temperatures in the
range of 50,000---500,000 degrees Kelvin. Our calculations show that the
gas-liquid boundary interaction has a strong effect on the internal gas
dynamics. We also estimate the duration of the light pulse from our model,
which predicts that it scales linearly with the ambient bubble radius.
  As the number of particles in a physical sonoluminescing bubble is within the
foreseeable capability of molecular dynamics simulations we also propose that
fine scale sonoluminescence experiments can be viewed as excellent test
problems for advancing the art of molecular dynamics.


title: Basics of Superluminal Signals

abstract:
  The paper elucidates the physical basis of experimental results on
superluminal signal velocity. It will be made plausible that superluminal
signals do not violate the principle of causality but they can shorten the
luminal vacuum time span between cause and effect. This amazing behaviour is
based on the property that any physical signal has a finite duration.


title: Regular solutions of Schwarzschild problem

abstract:
  Through an analysis and a generalization of a profound Fock's treatment, I
make conspicuous the physically essential role of those functions of the polar
radial coordinate for which the expressions of the spacetime interval are
everywhere regular for all values of the above coordinate.