title: New thermodynamic regularity for cesium over the whole liquid range

abstract:
  In this paper we derive an equation of state for liquid cesium based on a
suggested potential function in accord to the characteristics large attraction
and soft repulsion at the asymptotes of interaction potentials. By considering
the interaction of nearest adjacent atoms in dense fluid, the equation of state
predicts that the isotherm is linear function of, where is the compression
factor, is the molar volume, and is the molar density. The linear parameters
are identified as interaction coefficients related to attraction and repulsion,
and are used to evaluate the molecular parameters with interesting
implications. The isotherm is intended to resolve the particular thermodynamic
properties of alkali metals, which have been known for their unusual change of
the nature of intermolecular force as the characteristic metal-nonmetal
transition range is approached. When applied to liquid cesium, the isotherms
persist linear over the whole liquid range including the metal non-metals
transition range and at the critical temperature perfectly. The isotherm is
equivalent to a virial (like) EOS for which the linear parameters of the
isotherm form the corresponding second and third virial coefficients. The new
potential function turns out to be an effective potential that includes not
only a pair interaction but also many-body interactions and therefore it is not
always comparable with pair potential.


title: Fragments, Combustion and Earthquakes

abstract:
  This paper is devoted to show the advantages of introducing a geometric
viewpoint and a non extensive formulation in the description of apparently
unrelated phenomena: combustion and earthquakes. Here, it is shown how the
introduction of a fragmentation analysis based on that formulation leads to
find a common point for description of these phenomena


title: Pricing options with VG model using FFT

abstract:
  We discuss various analytic and numerical methods that have been used to get
option prices within a framework of the VG model. We show that some popular
methods, for instance, Carr-Madan's FFT method could blow up for certain values
of the model parameters even for an European vanilla option. Alternative
methods - one originally proposed by Lewis, and Black-Scholes-wise method are
considered that seem to work fine for any value of the VG parameters. Test
examples are given to demonstrate efficiency of these methods. Convergency of
all methods is also discussed.}


title: eBay users form stable groups of common interest

abstract:
  Market segmentation of an online auction site is studied by analyzing the
users' bidding behavior. The distribution of user activity is investigated and
a network of bidders connected by common interest in individual articles is
constructed. The network's cluster structure corresponds to the main user
groups according to common interest, exhibiting hierarchy and overlap. Key
feature of the analysis is its independence of any similarity measure between
the articles offered on eBay, as such a measure would only introduce bias in
the analysis. Results are compared to null models based on random networks and
clusters are validated and interpreted using the taxonomic classifications of
eBay categories. We find clear-cut and coherent interest profiles for the
bidders in each cluster. The interest profiles of bidder groups are compared to
the classification of articles actually bought by these users during the time
span 6-9 months after the initial grouping. The interest profiles discovered
remain stable, indicating typical interest profiles in society. Our results
show how network theory can be applied successfully to problems of market
segmentation and sociological milieu studies with sparse, high dimensional
data.


title: Non-trivial scaling of fluctuations in the trading activity of NYSE

abstract:
  Complex systems comprise a large number of interacting elements, whose
dynamics is not always a priori known. In these cases -- in order to uncover
their key features -- we have to turn to empirical methods, one of which was
recently introduced by Menezes and Barabasi. It is based on the observation
that for the activity f_i(t) of the constituents there is a power law
relationship between the standard deviation and the mean value: sigma_i ~
<f_i>^alpha. For stock market trading activity (traded value), good scaling
over 5 orders of magnitude with the exponent alpha = 0.72 was observed. The
origin of this non-trivial scaling can be traced back to a proportionality
between the rate of trades <N> and their mean sizes <V>. One finds <V> ~
<N>^0.69 for the ~1000 largest companies of New York Stock Exchange. Model
independent calculations show that these two types of scaling can be mapped
onto each other, with an agreement between the error bars. Finally, there is a
continuous increase in alpha if we look at fluctuations on an increasing time
scale up to 20 days.


title: Optical modulation in a resonant tunneling relaxation oscillator

abstract:
  We report high speed optical modulation in a resonant tunneling relaxation
oscillator consisting of a resonant tunneling diode (RTD) integrated with a
unipolar optical waveguide and incorporated in a package with a coplanar
waveguide transmission line. When appropriately biased, the RTD can provide
wide-bandwidth electrical gain. For wavelengths near the material band-edge,
small changes of the applied voltage give rise to large, high-speed
electro-absorption modulation of the light. We have observed optical modulation
at frequencies up to 14 GHz, associated with sub harmonic injection locking of
the RTD oscillation at the fundamental mode of the coplanar transmission line,
as well as generation of 33 ps optical pulses due to relaxation oscillation.


title: Comment on the Riemann Hypothesis

abstract:
  The Riemann hypothesis is identified with zeros of ${\cal N}=4$
supersymmetric gauge theory four-point amplitude. The zeros of the $\zeta(s)$
function are identified with th complex dimension of the spacetime, or the
dimension of the toroidal compactification. A sequence of dimensions are
identified in order to map the zeros of the amplitude to the Riemann
hypothesis.


title:
Multifractality of Inverse Statistics of Exit Distances in 3D Fully
  Developed Turbulence

abstract:
  The inverse structure functions of exit distances have been introduced as a
novel diagnostic of turbulence which emphasizes the more laminar regions [1-4].
Using Taylor's frozen field hypothesis, we investigate the statistical
properties of the exit distances of empirical 3D fully developed turbulence. We
find that the probability density functions of exit distances at different
velocity thresholds can be approximated by stretched exponentials with
exponents varying with the velocity thresholds below a critical threshold. We
show that the inverse structure functions exhibit clear extended
self-similarity (ESS). The ESS exponents \xi(p,2) for small p (p<3.5) are well
captured by the prediction of \xi(p,2)= p/2 obtained by assuming a universal
distribution of the exit distances, while the observed deviations for large p's
characterize the dependence of these distributions on the velocity thresholds.
By applying a box-counting multifractal analysis of the natural measure
constructed on the time series of exit distances, we demonstrate the existence
of a genuine multifractality, endowed in addition with negative dimensions.
Performing the same analysis of reshuffled time series with otherwise identical
statistical properties for which multifractality is absent, we show that
multifractality can be traced back to non-trivial dependence in the time series
of exit times, suggesting a non-trivial organization of weakly-turbulent
regions.


title:
Atomic Parity Violation : Principles, Recent Results, Present
  Motivations

abstract:
  We review the progress made in the determination of the weak charge, Q\_w, of
the cesium nucleus which raises the status of Atomic Parity Violation
measurements to that of a precision electroweak test. Not only is it necessary
to have a precision measurement of the electroweak asymmetry in the highly
forbidden 6S-7S transition, but one also needs a precise calibration procedure.
The 1999 precision measurement by the Boulder group implied a 2.5 sigma
deviation of Q\_w from the theoretical prediction. This triggered many particle
physicist suggestions as well as examination by atomic theoretical physicists
of several sources of corrections. After about three years the disagreement was
removed without appealing to "New Physics". Concurrently, an original
experimental approach was developed in our group for more than a decade. It is
based on detection by stimulated emission with amplification of the left- right
asymmetry. We present our decisive, recent progress together with our latest
results. We emphasize the important impact for electroweak theory, of future
measurements in cesium possibly pushed to the 0.1% level. Other possible
approaches are currently explored in several atoms.


title:
The effect of the range of interaction on the phase diagram of a
  globular protein

abstract:
  Thermodynamic perturbation theory is applied to the model of globular
proteins studied by ten Wolde and Frenkel (Science 277, pg. 1976) using
computer simulation. It is found that the reported phase diagrams are
accurately reproduced. The calculations show how the phase diagram can be tuned
as a function of the lengthscale of the potential.


title:
Multi-element cylindrical electrostatic lens systems for focusing and
  controlling charged particles

abstract:
  This paper describes theoretical modelling of electrostatic lenses based on
3, 4 and 5 closely spaced cylindrical electrodes, respectively. In each case,
modelling is carried out numerically using commercial packages SIMION and
LENSYS, and a variety of performance parameters are obtained. These include the
magnification, the 3rd order spherical and chromatic aberration coefficients.
Special cases such as zoom lens (i.e., lenses whose magnification may be
changed without losing focus) are considered. Results are obtained as a
function of the ratios of the electrode lengths and gaps, and as a function of
ratios of the controlling voltages.
  As a result, it is shown that how a multi-element lens system can be operated
with the whole focal properties in a useful mode for using in experimental
studies.


title: Atom-Wall interaction

abstract:
  This chapter deals with atom-wall interaction occurring in the "long-range"
regime (typical distances: 1-1000 nm), when the electromagnetic fluctuations of
an isolated atom are modified by the vicinity with a surface. Various regimes
of interaction are discussed in an Introductory part, from Cavity Quantum
ElectroDynamics modifications of the spontaneous emission, to Casimir effect,
with emphasis on the atom-surface van der Waals interaction, characterized as a
near-field interaction governed by a z-3 dependence. The major part of the
Chapter focuses on the experimental measurements of this van der Waals
interaction, reviewing various recent techniques, and insists upon optical
techniques, and notably selective reflection spectroscopy which is particularly
well-suited when excited atoms are considered. A review of various experiments
illustrates the specific effects associated with a resonant coupling between
the atomic excitation and surface modes, from van der Waals repulsion to
surface-induced resonant transfer, and with anisotropy effects, including
metastability transfer induced by a quadrupole contribution in the interaction.
The effects of a thermal excitation of the surface -with a possible remote
energy transfer to an atom-, and of interaction with nanobodies -which are
intrinsically non planar- are notably discussed among the prospects.


title: Enhancing Robustness and Immunization in geographical networks

abstract:
  We find that different geographical structures of networks lead to varied
percolation thresholds, although these networks may have similar abstract
topological structures. Thus, the strategies for enhancing robustness and
immunization of a geographical network are proposed. Using the generating
function formalism, we obtain the explicit form of the percolation threshold
$q_{c}$ for networks containing arbitrary order cycles. For 3-cycles, the
dependence of $q_c$ on the clustering coefficients is ascertained. The analysis
substantiates the validity of the strategies with an analytical evidence.


title:
Distance-dependent connectivity: Yet Another Approach to the Small World
  Phenomenon

abstract:
  We investigate a relationship network of humans located in a metric space
where relationships are drawn according to a distance-dependent probability
density. The obtained spatial graph allows us to calculate the average
separation of people in a very simple manner. The acquired results agree with
the well-known presence of the small-world phenomenon in human relationships.
They indicate that this feature can be understood merely as a consequence of
the probability composition. We also examine how this phenomenon evolves with
the development of human society.


title: Geographical effects on cascading breakdowns of scale-free networks

abstract:
  Cascading breakdowns of real networks are severe accidents in recent years,
such as the blackouts of the power transportation networks in North America. In
this paper, we study the effects of geographical structure on the cascading
phenomena of load-carried scale-free networks, find that more geographically
constrained networks tend to have larger cascading breakdowns. Explanations by
the effects of circles and large betweenness of small degree nodes are
provided.


title: Einstein y la Geometria

abstract:
  This is a semipopular introduction to the Special and General Theory of
Relativity, with special emphasis on the geometrical aspects of both theories
and their physical implications.


title: The Muon System of the Run II D0 Detector

abstract:
  We describe the design, construction and performance of the upgraded DO muon
system for Run II of the Fermilab Tevatron collider. Significant improvements
have been made to the major subsystems of the DO muon detector: trigger
scintillation counters, tracking detectors, and electronics. The Run II central
muon detector has a new scintillation counter system inside the iron toroid and
an improved scintillation counter system outside the iron toroid. In the
forward region, new scintillation counter and tracking systems have been
installed. Extensive shielding has been added in the forward region. A large
fraction of the muon system electronics is also new.


title:
Optical modulation at around 1550 nm in a InGaAlAs optical waveguide
  containing a InGaAs/AlAs resonant tunnelling diode

abstract:
  We report electro-absorption modulation of light at around 1550 nm in a
unipolar InGaAlAs optical waveguide containing a InGaAs/AlAs double-barrier
resonant tunneling diode (DB-RTD). The RTD peak-to-valley transition increases
the electric field across the waveguide, which shifts the core material
absorption band-edge to longer wavelengths via the Franz-Keldysh effect, thus
changing the light-guiding characteristics of the waveguide. Low-frequency
characterisation of a device shows modulation up to 28 dB at 1565 nm. When dc
biased close to the negative differential conductance (NDC) region, the RTD
optical waveguide behaves as an electro-absorption modulator integrated with a
wide bandwidth electrical amplifier, offering a potential advantage over
conventional pn modulators.


title:
Relationship between acoustic body waves and in situ stresses around a
  borehole

abstract:
  This paper shows that there are three types of shape of acoustic body waves
propagating inside competent and homogeneous formations penetrated by a
borehole : simple, double, and resonant. This fact is connected to the
modifications undergone by the area located around a well after drilling in
relation to in situ state of stress. There are overstressed and understressed
vertical cylindrical zones with "bubble-shaped" cross-sections, in which
acoustic body waves are supposed to reflect. The horizontal size and the shape
of the stress modified areas depend on the values of (K1+K2)/2 - with K1=SH/Sv
(the overburden pressure) and K2=Sh/Sv -, that is to say on the in situ
horizontal stress and the anisotropy of this stress. The calculation of the
velocities of the P and S double waves allows us to evaluate the radial
thicknesses of these stress modified areas. As their values are different
according to whether they result from P or S waves, we propose an explanation
based on their wavelengths. The comparisons with other works on the in situ
stress of the studied boreholes allow us to propose a method for evaluating the
horizontal stress and its anisotropy, thanks to the estimation of the value
(K1+K2)/2.


title: Complete bandgaps in one-dimensional left-handed periodic structures

abstract:
  Artificially fabricated structures with periodically modulated parameters
such as photonic crystals offer novel ways of controlling the flow of light due
to the existence of a range of forbidden frequencies associated with a photonic
bandgap. It is believed that modulation of the refractive index in all three
spatial dimensions is required to open a complete bandgap and prevent the
propagation of electromagnetic waves in all directions. Here we reveal that, in
a sharp contrast to what was known before and contrary to the accepted physical
intuition, a one-dimensional periodic structure containing the layers of
transparent left-handed (or negative-index) metamaterial can trap light in
three-dimensional space due to the existence of a complete bandgap.


title: Describing two-dimensional vortical flows : the typhoon case

abstract:
  We present results of a numerical study of the differential equation
governing the stationary states of the two-dimensional planetary atmosphere and
magnetized plasma (within the Charney Hasegawa Mima model). The most strinking
result is that the equation appears to be able to reproduce the main features
of the flow structure of a typhoon.


title: Lorentz-contraction formula from non-simultaneous events

abstract:
  We present a derivation of the relativistic length-contraction formula based
on Lorentz space-time transformations on non-simultaneous events. Our
derivation avoids the disputable story about the stationary observer and its
simultaneous measurements of object's end-points.


title:
Conditional Probability as a Measure of Volatility Clustering in
  Financial Time Series

abstract:
  In the past few decades considerable effort has been expended in
characterizing and modeling financial time series. A number of stylized facts
have been identified, and volatility clustering or the tendency toward
persistence has emerged as the central feature. In this paper we propose an
appropriately defined conditional probability as a new measure of volatility
clustering. We test this measure by applying it to different stock market data,
and we uncover a rich temporal structure in volatility fluctuations described
very well by a scaling relation. The scale factor used in the scaling provides
a direct measure of volatility clustering; such a measure may be used for
developing techniques for option pricing, risk management, and economic
forecasting. In addition, we present a stochastic volatility model that can
display many of the salient features exhibited by volatilities of empirical
financial time series, including the behavior of conditional probabilities that
we have deduced.


title:
Evidence for a Global Warming at the Termination I Boundary and Its
  Possible Cosmic Dust Cause

abstract:
  A comparison of northern and southern hemispheric paleotemperature profiles
suggests that the Bolling-Allerod Interstadial, Younger Dryas stadial, and
subsequent Preboreal warming which occurred at the end of the last ice age were
characterized by temperatures that changed synchronously in various parts of
the world, implying that these climatic oscillations were produced by
significant changes in the Earth's energy balance. These globally coordinated
oscillations are not easily explained by ocean current mechanisms such as
bistable flipping of ocean deep-water production or regional temperature
changes involving the NW/SE migration of the North Atlantic polar front. They
also are not accounted for by Earth orbital changes in seasonality or by
increases in atmospheric CO-2 or CH-4. On the other hand, evidence of an
elevated cosmic ray flux and of a major interstellar dust incursion around
15,800 years B.P. suggest that a cosmic ray wind driven incursion of
interstellar dust and gas may have played a key role through its activation of
the Sun and alteration of light transmission through the interplanetary medium.


title: Fast Factoring of Integers

abstract:
  An algorithm is given to factor an integer with $N$ digits in $\ln^m N$
steps, with $m$ approximately 4 or 5. Textbook quadratic sieve methods are
exponentially slower. An improvement with the aid of an a particular function
would provide a further exponential speedup.


title: Lattice Boltzmann Model for Axisymmetric Multiphase Flows

abstract:
  In this paper, a lattice Boltzmann (LB) model is presented for axisymmetric
multiphase flows. Source terms are added to a two-dimensional standard lattice
Boltzmann equation (LBE) for multiphase flows such that the emergent dynamics
can be transformed into the axisymmetric cylindrical coordinate system. The
source terms are temporally and spatially dependent and represent the
axisymmetric contribution of the order parameter of fluid phases and inertial,
viscous and surface tension forces. A model which is effectively explicit and
second order is obtained. This is achieved by taking into account the discrete
lattice effects in the Chapman-Enskog multiscale analysis, so that the
macroscopic axisymmetric mass and momentum equations for multiphase flows are
recovered self-consistently. The model is extended to incorporate reduced
compressibility effects. Axisymmetric equilibrium drop formation and
oscillations, breakup and formation of satellite droplets from viscous liquid
cylindrical jets through Rayleigh capillary instability and drop collisions are
presented. Comparisons of the computed results with available data show
satisfactory agreement.


title:
How Hertzian solitary waves interact with boundaries in a 1-D granular
  medium

abstract:
  We perform measurements, numerical simulations, and quantitative comparisons
with available theory on solitary wave propagation in a linear chain of beads
without static preconstrain. By designing a nonintrusive force sensor to
measure the impulse as it propagates along the chain, we study the solitary
wave reflection at a wall. We show that the main features of solitary wave
reflection depend on wall mechanical properties. Since previous studies on
solitary waves have been performed at walls without these considerations, our
experiment provides a more reliable tool to characterize solitary wave
propagation. We find, for the first time, precise quantitative agreements.


title:
Orientation changes of the large-scale circulation in turbulent
  Rayleigh-Benard convection

abstract:
  We present measurements of the orientation theta_0(t) of the large-scale
circulation (LSC) of turbulent Rayleigh-Benard convection in cylindrical cells
of aspect ratio 1. theta_0(t) undergoes irregular reorientations. It contains
reorientation events by rotation through angles Delta theta with a
monotonically decreasing probability distribution p(Delta theta), and by
cessations (where the LSC stops temporarily) with a uniform p(Delta theta).
Reorientations have Poissonian statistics in time. The amplitude of the LSC and
the magnitude of the azimuthal rotation rate have a negative correlation.


title: Stock Mechanics: a classical approach

abstract:
  New theoretical approaches about forecasting stock markets are proposed. A
mathematization of the stock market in terms of arithmetical relations is
given, where some simple (non-differential, non-fractal) expressions are also
suggested as general stock price formuli in closed forms which are able to
generate a variety of possible price movements in time. A kind of mechanics is
submitted to cover the price movements in terms of classical concepts. Where
utilizing stock mechanics to grow the portfolios in real markets is also
proven.


title: Some Aspects of the Electromagnetic Multipole Expansions

abstract:
  Various procedures for expressing the multipolar expansion of the
electromagnetic field are considered with application to the calculation of the
radiated power. Some results from literature are discussed and perspective of
developing the subject is pointed out.


title:
Formation, Manipulation, and Elasticity Measurement of a Nanometric
  Column of Water Molecules

abstract:
  Nanometer-sized columns of condensed water molecules are created by an
atomic-resolution force microscope operated in ambient conditions. Unusual
stepwise decrease of the force gradient associated with the thin water bridge
in the tip-substrate gap is observed during its stretch, exhibiting regularity
in step heights (~0.5 N/m) and plateau lengths (~1 nm). Such "quantized"
elasticity is indicative of the atomic-scale stick-slip at the tip-water
interface. A thermodynamic-instability-induced rupture of the water meniscus
(5-nm long and 2.6-nm wide) is also found. This work opens a high-resolution
study of the structure and the interface dynamics of a nanometric aqueous
column.


title:
Sub-Rayleigh resolution of interference pattern with independent laser
  beams

abstract:
  We propose a new scheme to achieve sub-Rayleigh resolution of interference
pattern with independent laser beams. We perform an experimental observation of
a double-slit interference with two orthogonally polarized laser beams. The
resolution of the interference pattern measured by a two-photon detection is
doubled provided the two beams illuminate the double-slit with certain incident
angles. The scheme is simple and can be in favor of both high intensity and
perfect visibility.


title: Comment on "Heisenberg in Poland" by Jeremy Bernstein

abstract:
  Some erroneous and misleading statements in an article by J. Bernstein on
Heisenberg's visit to Cracow during the war are corrected.


title: Cyclic Topology in Complex Networks

abstract:
  We propose a cyclic coefficient $R$ which represents the cyclic
characteristics of complex networks. If the network forms a perfect tree-like
structure then $R$ becomes zero. The larger value of $R$ represents that the
network is more cyclic. We measure the cyclic coefficients and the
distributions of the local cyclic coefficient for both various real networks
and the representative network models and characterize the cyclic structures of
them.


title: Pair Dispersion in Turbulence

abstract:
  Turbulent mixing of liquids and gasses is ubiquitous in nature. It is the
basis of all industrial fluid mixing processes, and it determines the spread of
pollutants or bioagents in the atmosphere and oceans. Biological organisms even
use it to survive in marine ecosystems. A fundamental component of turbulent
mixing is the separation of two nearby fluid elements, i.e., pair dispersion.
Despite almost eighty years of intense scientific inquiry, no clear
understanding of this fundamental aspect of turbulence has emerged. One
critical unresolved question is the extent to which the initial separation of
the fluid particles influences their subsequent motion. Surprisingly, our
measurements in a laboratory water flow at very high turbulence levels (Taylor
microscale Reynolds numbers up to R_lambda = 815) suggest that the initial
separation remains important for all but the most violent flows on Earth. This
observation has important consequences for such varied problems as pollution
control, combustion modelling, hazardous chemical control, and even the
understanding of how animals locate food, predators, and mates.


title: Photonic band structure of ZnO photonic crystal slab laser

abstract:
  We recently reported on the first realization of ultraviolet photonic crystal
laser based on zinc oxide [Appl. Phys. Lett. {\bf 85}, 3657 (2004)]. Here we
present the details of structural design and its optimization. We develop a
computational super-cell technique, that allows a straightforward calculation
of the photonic band structure of ZnO photonic crystal slab on sapphire
substrate. We find that despite of small index contrast between the substrate
and the photonic layer, the low order eigenmodes have predominantly
transverse-electric (TE) or transverse-magnetic (TM) polarization. Because
emission from ZnO thin film shows strong TE preference, we are able to limit
our consideration to TE bands, spectrum of which can possess a complete
photonic band gap with an appropriate choice of structure parameters. We
demonstrate that the geometry of the system may be optimized so that a sizable
band gap is achieved.


title: Numerical Solution of the 1D Schr\"odinger Equation: Bloch Wavefunctions

abstract:
  In this article we discuss a procedure to solve the one dimensional (1D)
Schroedinger Equation for a periodic potential, which may be well suited to
teach band structure theory. The procedure is conceptually very simple, so that
it may be used to teach band theory at the undergraduate level; at the same
time the point of view is practical, so that the students may experiment
computing band gaps, and other features of band structure. Another advantage of
the procedure lies in that it does not use specific symmetry properties of the
potential, so that the results are generally valid.


title: The Neutrino - Its Past, Present and Future

abstract:
  The review consists of two parts. In the first part the critical points in
the past, present and future of neutrino physics (nuclear, particle and
astroparticle) are reviewed. In the second part the contributions of Yugoslav
physics to the physics of the neutrino are commented upon. The review is meant
as a first reading for the newcomers to the field of neutrino physics.


title:
Terahertz generation in Czochralski grown periodically poled Mg:Y:LiNbO3
  via optical rectification

abstract:
  Using a canonical pump-probe experimental technique, we studied the terahertz
(THz) waves generation and detection via optical rectification and mixing in
Czochralski-grown periodically poled Mg:Y:LiNbO3 (PPLN) crystals. THz waves
with frequencies at 1.37 THz and 0.68 THz as well as 1.8 THz were obtained for
PPLN with nonlinear grating periods of 0.03 and 0.06 mm, respectively. A
general theoretical model was developed by considering the dispersion and
damping of low frequency phonon-polariton mode. Our results show that THz waves
are generated in forward and backward directions via pumping pulse
rectification. The generated THz waves depend on the spectral shape of the
laser pulses, quasi-phase mismatches and dispersion characteristics of a
crystal.


title:
Reduction of wood hygroscopicity and associated dimensional response by
  repeated humidity cycles

abstract:
  The reduction of wood response to variations of ambient humidity, described
as kind of ageing, has been studied from both points of view of moisture uptake
and dimensional changes. Clearwood specimens from 3 gymnosperms (Pinus
sylvestris L., Pinus pinaster Ait., Pinus insignis Dougl.) and 4 angiosperms
(Populus spp., Quercus pyrenaica Willd., Entandrophragma cylindricum Sprague,
Chlorophora excelsa Benth. & Hook f.) were subjected to five wet-dry cycles and
their moisture content and dimensional changes in radial and tangential
direction at three increasing levels of relative humidity (57.6, 84.2 and
90.2%) were measured before and after the treatment. For a given increase of
relative humidity, a coefficient of hygroscopic ageing was defined as the
relative decrease of moisture uptake, and the coefficient of dimensional ageing
as the difference of swelling strain before and after ageing. All species
exhibited a clear ageing effect, much stronger in the wet range than in the dry
range. Calculation of swelling coefficients suggested that in some cases the
relation between swelling strain and moisture content is no longer linear in
aged wood.


title: Geometric Solutions to Algebraic Equations

abstract:
  A method to the explict solutions of general systems of algebraic equations
is presented via the metric form of affiliated K\"ahler manifolds. The
solutions to these systems arise from sets of geodesic second order non-linear
differential equations. Algebraic equations in various fields such as integers
and rational numbers, as well as transcendental equations, are amenable. The
case of Fermat's set of equations is a subset.


title: Statistical properties of an experimental political futures market

abstract:
  A 24-hour exchange market was created on the Web to trade political futures
contracts using fictitious money. In this online market, a political futures
contract is a futures contract which matures on the election day with a
liquidation price determined by the percentage of votes a candidate receives on
the election day. Continuous double auctions were implemented as the system for
order storage and price discovery. We drew market participants in the form of
tournaments in which top traders won cash awards. Such a market was run, with
about 400 registered traders, during the U.S. presidential election in November
2004 and Taiwan parliamentary election in December 2004. The experiments
recorded transaction price, highest bid, lowest ask, and trading volume of each
contract as a function of time. Despite the relatively small scale of the
exchange, in terms of the number of participants and duration of the
tournament, we report evidence for asymptotic power-law behaviors of the
distributions of price returns, trading volumes, inter-transaction time
intervals, and accumulated wealth that were found universal in real financial
markets.


title: Shareholding Networks in Japan

abstract:
  The Japanese shareholding network existing at the end of March 2002 is
studied empirically. The network is constructed from 2,303 listed companies and
53 non-listed financial institutions. We consider this network as a directed
graph by drawing edges from shareholders to stock corporations. The lengths of
the shareholder lists vary with the companies, and the most comprehensive lists
contain the top 30 shareholders. Consequently, the distribution of incoming
edges has an upper bound, while that of outgoing edges has no bound. The
distribution of outgoing degrees is well explained by the power law function
with an exponential tail. The exponent in the power law range is gamma=1.7. To
understand these features from the viewpoint of a company's growth, we consider
the correlations between the outgoing degree and the company's age, profit, and
total assets.


title: Swelling of acetylated wood in organic liquids

abstract:
  To investigate the affinity of acetylated wood for organic liquids, Yezo
spruce wood specimens were acetylated with acetic anhydride, and their swelling
in various liquids were compared to those of untreated specimens. The
acetylated wood was rapidly and remarkably swollen in aprotic organic liquids
such as benzene and toluene in which the untreated wood was swollen only
slightly and/or very slowly. On the other hand, the swelling of wood in water,
ethylene glycol and alcohols remained unchanged or decreased by the
acetylation. Consequently the maximum volume of wood swollen in organic liquids
was always larger than that in water. The effect of acetylation on the maximum
swollen volume of wood was greater in liquids having smaller solubility
parameters. The easier penetration of aprotic organic liquids into the
acetylated wood was considered to be due to the scission of hydrogen bonds
among the amorphous wood constituents by the substitution of hydroxyl groups
with hydrophobic acetyl groups.


title:
A laboratory work: A teaching robot arm for mechanics and electronic
  circuits

abstract:
  Mechanics and electronic systems can be applied to the physical models to
understand the physical phenomena for students in laboratory. In this paper we
have developed a robot arm for a laboratory experiment, where students learn
how to design a human arm and fingers with basic knowledge of the mechanics and
electronics. This experiment culminates in an exhibition tie together aspects
of a surprisingly wide range of disciplines and represents an alternative
vision of how robot arm design can be used to teach both physics and
electric/electronic engineering. A new tool is described that combines the
mechanical arrangement with an electronic control circuit and it is shown that
this can be readily used as an instructional tool in the physics laboratory to
teach the law of mechanics and basic electronic devices for both teacher and
students.


title:
Assessment of Various Density Functionals and Basis Sets for the
  Calculation of Molecular Anharmonic Force Fields

abstract:
  In a previous contribution (Mol. Phys. {\bf 103}, xxxx, 2005), we established
the suitability of density functional theory (DFT) for the calculation of
molecular anharmonic force fields. In the present work, we have assessed a wide
variety of basis sets and exchange-correlation functionals for harmonic and
fundamental frequencies, equilibrium and ground-state rotational constants, and
thermodynamic functions beyond the RRHO (rigid rotor-harmonic oscillator)
approximation. The fairly good performance of double-zeta plus polarization
basis sets for frequencies results from an error compensation between basis set
incompleteness and the intrinsic error of exchange-correlation functionals.
Triple-zeta plus polarization basis sets are recommended, with an additional
high-exponent $d$ function on second-row atoms. All conventional hybrid GGA
functionals perform about equally well: high-exchange hybrid GGA and meta-GGA
functionals designed for kinetics yield poor results, with the exception of of
the very recently developed BMK functional which takes a middle position along
with the HCTH/407 (second generation GGA) and TPSS (meta-GGA) functionals. MP2
performs similarly to these functionals but is inferior to hybrid GGAs such as
B3LYP and B97-1.


title: Scientific Eschatology

abstract:
  The future evolution of the universe suggested by the cosmological model
proposed earlier at this meeting by the authors is explored. The fundamental
role played by the positive "cosmological constant" is emphasized. Dyson's 1979
paper entitled "Time Without End" is briefly reviewed. His most optimistic
scenario requires that the universe be geometrically open and that biology is
structural in the sense that the current complexity of human society can be
reproduced by scaling up its (quantum mechanical) structure to arbitrary size.
If the recently measured "cosmological constant" is indeed a fundamental
constant of nature, then Dyson's scenario is, for various reasons, ruled out by
the finite (De Sitter) horizon due to exponential expansion of the resulting
space. However, the finite temperature of that horizon does open other
interesting options. If, as is suggested by the cosmology under consideration,
the current exponential expansion of the universe is due to a phase transition
which fixes a physical boundary condition during the early radiation dominated
era, the behavior of the universe after the relevant scale factor crosses the
De Sitter radius opens up still other possibilities. The relevance of Martin
Rees' apocalyptic eschatology recently presented in his book "Our Final Hour"
is mentioned. It is concluded that even for the far future, whether or not
cultural and scientific descendants of the current epoch will play a role in
it, an understanding (sadly, currently lacking) of community and political
evolution and control is essential for a preliminary treatment of what could be
even vaguely called scientific eschatology.


title: On some recent results about inertial manifolds and kinematic dynamos

abstract:
  The conditions imposed in the paper ['Inertial manifolds and completeness of
eigenmodes for unsteady magnetic dynamos', Physica D {\bf 194} (2004) 297-319]
on the fluid velocity to guarantee the existence of inertial manifolds for the
kinematic dynamo problem are too demanding, in the sense that they imply that
all the solutions tend exponentially to zero. The inertial manifolds are
meaningful because they represent different decay rates, but the classical
kinematic dynamos where the magnetic field is maintained or grows are not
covered by this approach, at least until more refined estimates are found.


title:
Is the San Andreas Fracture a bayonet-shaped fracture as inferred from
  the acoustic body waves in the SAFOD Pilot hole ?

abstract:
  The method using the propagation of acoustic body waves within the stress
modified areas around a vertical borehole has been applied to the granitic
formation penetrated by the SAFOD Pilot hole near the San Andreas Fault trace.
This method allows us investigating the horizontal in situ stresses. Only P
waves supplied useful and surprising information. A depth of 1270 m separates
an upper region of uniform thickness of stress modified areas, possibly
corresponding to a shear domain, and a lower region where there are
simultaneously two values of the thicknesses of the stress modified areas
(particularly between 1500 and 1600 m of depth) possibly corresponding to a
compressive and a shear domain. In order to integrate the contradictory effects
of the simultaneity of shear and compressive domains at some depths, as well as
the presence of three shear zones at particular depths, we propose that the San
Andreas Fault could be bayonet-shaped instead of planar. Other recent available
information in the literature about this fault, such as the presence of a fault
zone of low shear wave velocity, stress rotation measured with depth, and the
large angles of the frictional coefficients, can be logically explained by this
kind of fault geometry.


title:
A Model for Collaboration Networks Giving Rise to a Power Law
  Distribution with an Exponential Cutoff

abstract:
  Recently several authors have proposed stochastic evolutionary models for the
growth of complex networks that give rise to power-law distributions. These
models are based on the notion of preferential attachment leading to the ``rich
get richer'' phenomenon. Despite the generality of the proposed stochastic
models, there are still some unexplained phenomena, which may arise due to the
limited size of networks such as protein, e-mail, actor and collaboration
networks. Such networks may in fact exhibit an exponential cutoff in the
power-law scaling, although this cutoff may only be observable in the tail of
the distribution for extremely large networks. We propose a modification of the
basic stochastic evolutionary model, so that after a node is chosen
preferentially, say according to the number of its inlinks, there is a small
probability that this node will become inactive. We show that as a result of
this modification, by viewing the stochastic process in terms of an urn
transfer model, we obtain a power-law distribution with an exponential cutoff.
Unlike many other models, the current model can capture instances where the
exponent of the distribution is less than or equal to two. As a proof of
concept, we demonstrate the consistency of our model empirically by analysing
the Mathematical Research collaboration network, the distribution of which is
known to follow a power law with an exponential cutoff.


title:
Time and space reconstruction in optical, non-imaging,
  scintillator-based particle detectors

abstract:
  A new generation of ultra-low-background scintillator-based detectors aims to
study solar neutrinos and search for dark matter and new physics beyond the
Standard Model. These optical, non-imaging detectors generally contain a
"fiducial volume" from which data are accepted, and an "active buffer region"
where there are higher levels of radioactive contaminants. Events are observed
in real time. To distinguish between events occurring in the two regions, it is
imperative that event position reconstruction be well-understood. The object of
this paper is the study of the reconstruction, in time and space, of
scintillation events in detectors of large dimensions. A general,
likelihood-based method of position reconstruction for this class of detectors
is presented. The potential spatial resolution of the method is then evaluated.
It is shown that for a spherical detector with a large number N of
photosensitive elements that detect photons, the expected spatial resolution at
the center of the detector is given by delta a ~ (c sigma / n) sqrt(3/N), where
sigma is the width of the scintillator time response function and n is the
index of refraction in the medium. However, if light in the detector has a
scattering mean free path much less than the detector radius R, the resolution
instead becomes (R/2) sqrt(3/N). Finally, a formalism is introduced to deal
with the common case in which only the arrival time of the first photon to
arrive at each photosensitive element can be measured.


title:
A simple model for the short-time evolution of near-surface current and
  temperature profiles

abstract:
  A simple analytical/numerical model has been developed for computing the
evolution, over periods of up to a few hours, of the current and temperature
profile in the upper layer of the ocean. The model is based upon conservation
laws for heat and momentum, and employs an eddy diffusion parameterisation
which is dependent on both the wind speed and the wind stress applied at the
sea surface. Other parameters such as the bulk-skin surface temperature
difference and CO$_2$ flux are determined by application of the Molecular
Oceanic Boundary Layer Model (MOBLAM) of Schluessel and Soloviev. A similar
model, for the current profile only, predicts a temporary increase in wave
breaking intensity and decrease in wave height under conditions where the wind
speed increases suddenly, such as, for example, during gusts and squalls. The
model results are compared with measurements from the lagrangian Skin Depth
Experimental Profiler (SkinDeEP) surface profiling instrument made during the
1999 MOCE-5 field experiment in the waters around Baja California. SkinDeEP
made repeated profiles of temperature within the upper few metres of the water
column. Given that no tuning was performed in the model, and that the model
does not take account of stratification, the results of the model runs are in
rather good agreement with the observations. The model may be suitable as an
interface between time-independent models of processes very near the surface,
and larger-scale three-dimensional time-dependent ocean circulation models. A
straightforward extension of the model should also be suitable for making
time-dependent computations of gas concentration in the near-surface layer of
the ocean.


title:
Reply to comment on `A simple model for the short-time evolution of
  near-surface current and temperature profiles'

abstract:
  This is our response to a comment by Walter Eifler on our paper `A simple
model for the short-time evolution of near-surface current and temperature
profiles' (arXiv:physics/0503186, accepted for publication in Deep-Sea Research
II). Although Eifler raises genuine issues regarding our model's validity and
applicability, we are nevertheless of the opinion that it is of value for the
short-term evolution of the upper-ocean profiles of current and temperature.
The fact that the effective eddy viscosity tends to infinity for infinite time
under a steady wind stress may not be surprising. It can be interpreted as a
vertical shift of the eddy viscosity profile and an increase in the size of the
dominant turbulent eddies under the assumed conditions of small stratification
and infinite water depth.


title:
Experimental test of the compatibility of the definitions of the
  electromagnetic energy density and the Poynting vector

abstract:
  It is shown that the generally accepted definition of the Poynting vector and
the energy flux vector defined by means of the energy density of the
electromagnetic field (Umov vector) lead to the prediction of the different
results touching electromagnetic energy flux. The experiment shows that within
the framework of the mentioned generally accepted definitions the Poynting
vector adequately describes the electromagnetic energy flux unlike the Umov
vector. Therefore one can conclude that a generally accepted definitions of the
electromagnetic energy density and the Poynting vector, in general, are not
always compatible.


title: How political parties adjust to fixed voter opinions

abstract:
  We propose a new version of the spatial model of voting. Platforms of five
parties are evolving in a two-dimensional landscape of political issues so as
to get maximal numbers of voters. For a Gaussian landscape the evolution leads
to a spatially symmetric state, where the platform centers form a pentagon
around the Gaussian peak. For a bimodal landscape the platforms located at
different peaks get different numbers of voters.


title: Exact Expansion Law for Richtmyer-Meshkov Turbulent Mixing Zone

abstract:
  Development of the Richtmyer-Meshkov instability leads to mixing of two
substances separated by contact boundary. Mixture of two fluids is confined
between two mixing fronts. Universal asymptotics follows the transition stage
at late time. Functions which describe the fronts penetration asymptoticaly
transform to power law dependences. Mixing is acompanied by cascade of
enlarging of dominant scale of a turbulent mixing zone. The exponents of the
power laws are: 2/5 for 2D and 1/3 for 3D cases. These exact exponents are
calculated in our work. They are determined by the mechanism of redistribution
of momentum from small into the large scales.


title: Decay Chain Fitting with a Kalman Filter

abstract:
  We present a method to perform a least squares fit of a decay chain involving
multiple decay vertices. Our technique allows for the simultaneous extraction
of decay time, position and momentum parameters and their uncertainties and
correlations for all particles in a decay chain.


title: Multiple species atom source for laser-cooling experiments

abstract:
  We describe the design of a single beam, multiple species atom source in
which the flux of any component can be separately adjusted. Using this design
we have developed a 23Na-6Li atom source for ultracold atom experiments. The
fluxes of lithium and sodium are independently tunable, allowing operation as a
single 23Na or 6Li source as well as a double source with equal atomic fluxes
in each component.


title: Unusual formations of the free electromagnetic field in vacuum

abstract:
  It is shown that there are exact solutions of the free Maxwell equations
(FME) in vacuum allowing an existence of stable spherical formations of the
free magnetic field and ring-like formations of the free electric field. It is
detected that a form of these spheres and rings does not change with time in
vacuum. It is shown that these convergent solutions are the result of an
interference of some divergent solutions of FME. One can surmise that these
electromagnetic formations correspond to Kapitsa's hypothesis about
interference origin and a structure of fireball.


title: Geometric Solutions to Non-linear Differential Equations

abstract:
  A general formalism to solve nonlinear differential equations is given.
Solutions are found and reduced to those of second order nonlinear differential
equations in one variable. The approach is uniformized in the geometry and
solves generic nonlinear systems. Further properties characterized by the
topology and geometry of the associated manifolds may define global properties
of the solutions.


title: Signatures of direct double ionization under XUV radiation

abstract:
  In anticipation of upcoming two-photon double ionization of atoms and
particularly Helium, under strong short wavelength radiation sources (45 eV),
we present quantitative signatures of direct two-photon double ejection, in the
photoelectron spectrum (PES) and the peak power dependence, that can be
employed in the interpretation of related data. We show that the PES provides
the cleanest signature of the process. An inflection (knee) in the laser power
dependence of double ionization is also discernible, within a window of
intensities which depends on the pulse duration and cross sections


title:
Scattering of Dirac particles from non-local separable potentials: the
  eigenchannel approach

abstract:
  An application of the new formulation of the eigenchannel method [R.
Szmytkowski, Ann. Phys. (N.Y.) {\bf 311}, 503 (2004)] to quantum scattering of
Dirac particles from non-local separable potentials is presented. Eigenchannel
vectors, related directly to eigenchannels, are defined as eigenvectors of a
certain weighted eigenvalue problem. Moreover, negative cotangents of
eigenphase-shifts are introduced as eigenvalues of that spectral problem.
Eigenchannel spinor as well as bispinor harmonics are expressed throughout the
eigenchannel vectors. Finally, the expressions for the bispinor as well as
matrix scattering amplitudes and total cross section are derived in terms of
eigenchannels and eigenphase-shifts. An illustrative example is also provided.


title: The origin of transport barriers in toroidal plasmas

abstract:
  A transport barrier in a toroidal plasma is treated as the boundary region
between the hot and cold phases of the plasma. These two phases possess
essentially different collisional and transport properties, so the boundary
region between them corresponds to the minimum values of specific resistivity
and transport coefficients of the plasma. The behavior of magnetic shear in the
region of a transport barrier and some other specific properties of transport
barriers are the consequences of the minimum plasma resistivity in this region.
The origin of sawtooth oscillations in toroidal plasmas is shown to have a
similar nature.


title:
Science Icebreaker Activities: An Example from Gravitational Wave
  Astronomy

abstract:
  At the beginning of a class or meeting an icebreaker activity is often used
to help loosen the group and get everyone talking. Our motivation is to develop
activities that serve the purpose of an icebreaker, but are designed to enhance
and supplement a science-oriented agenda. The subject of this article is an
icebreaker activity related to gravitational wave astronomy. We first describe
the unique gravitational wave signals from three distinct sources:
monochromatic binaries, merging compact objects, and extreme mass ratio
encounters. These signals form the basis of the activity where participants
work to match an ideal gravitational wave signal with noisy detector output for
each type of source.


title: Opinion dynamics and decision of vote in bipolar political systems

abstract:
  A model of the opinion dynamics underlying the political decision is
proposed. The analysis is restricted to a bipolar scheme with a possible third
political area. The interaction among voters is local but the final decision
strongly depends on global effects such as, for example, the rating of the
governments. As in the realistic case, the individual decision making process
is determined by the most relevant personal interests and problems. The
phenomenological analysis of the national vote in Italy and Germany has been
carried out and a prediction of the next Italian vote as a function of the
government rating is presented.


title: Integer and Rational Solutions to Polynomial Equations

abstract:
  A formalism is given to count integer and rational solutions to polynomial
equations with rational coefficients. These polynomials $P(x)$ are
parameterized by three integers, labeling an elliptic curve. The counting of
the rational solutions to $y^2=P(x)$ is facilitated by another elliptic curve
with integral coefficients. The problem of counting is described by two
elliptic curves and a map between them.


title: Steady f-plane circulation in basins with saddle-point bathymetry

abstract:
  J. Nilsson, G. Walin, and G. Brostroem (paper accepted by Journal of Marine
Research, 2005) have recently shown how a velocity field in geostrophic and
hydrostatic balance in an f-plane may be diagnosed from prescribed
distributions of buoyancy and wind stress, in a basin with closed isobaths. I
extend their analysis to cover basins with more complex depth contours,
treating in particular the behaviour of the flow in the presence of a saddle
point.


title: Relaxation of atomic polarization in paraffin-coated cesium vapor cells

abstract:
  The relaxation of atomic polarization in buffer-gas-free, paraffin-coated
cesium vapor cells is studied using a variation on Franzen's technique of
``relaxation in the dark'' [Franzen, Phys. Rev. {\bf 115}, 850 (1959)]. In the
present experiment, narrow-band, circularly polarized pump light, resonant with
the Cs D2 transition, orients atoms along a longitudinal magnetic field, and
time-dependent optical rotation of linearly polarized probe light is measured
to determine the relaxation rates of the atomic orientation of a particular
hyperfine level. The change in relaxation rates during light-induced atomic
desorption (LIAD) is studied. No significant change in the spin relaxation rate
during LIAD is found beyond that expected from the faster rate of spin-exchange
collisions due to the increase in Cs density.


title:
Helmholtz theorem and the v-gauge in the problem of superluminal and
  instantaneous signals in classical electrodynamics

abstract:
  In this work we substantiate the applying of the Helmholtz vector
decomposition theorem (H-theorem) to vector fields in classical
electrodynamics. Using the H-theorem, within the framework of the two-parameter
Lorentz-like gauge (so called v-gauge), we show that two kinds of magnetic
vector potentials exist: one of them (solenoidal) can act exclusively with the
velocity of light c and the other one (irrotational) with an arbitrary finite
velocity $v$ (including a velocity more than c . We show also that the
irrotational component of the electric field has a physical meaning and can
propagate exclusively instantaneously.


title:
Role of the Gelatinous Layer (G-Layer) on the Origin of the Physical
  Properties of the Tension Wood of Acer sieboldianum

abstract:
  The tension wood (TW) properties of a 70 year-old Acer sieboldianum Miq were
analyzed by using the G-fiber model which was proposed in our previous paper.
The roles of the G-layer on the origins of (1) a high large tensile growth
stress, (2) a large longitudinal Young's modulus, and (3) a high longitudinal
drying shrinkage in the tension wood xylem were discussed on the basis of the
simulations using the G-fiber model. The results suggest that the G-layer
generates a high tensile stress in the longitudinal direction during the xylem
maturation; the longitudinal Young's modulus of the green G-layer becomes
significantly higher than that of the lignified layer; furthermore, the G-layer
tends to shrink extraordinarily higher than that of the lignified layer during
the moisture desorption.


title: Mod\'{e}lisation des d\'{e}formations de maturation de la fibre

abstract:
  The generation mechanism of growth strains is investigated theoretically by
developing an elastic analysis of a wood cell viewed as a composite tube, with
layers composed of a ligno-cellulosic material of varying composition and
microfibrillar orientation. For each layer, the kinetics of induced strain is
assumed synchronous with that of rigidification. In this case, variations of
polymer behaviour concomitant with orientation must be invoked to account for
observed variations of the growth strain.


title: Neutrinos in the Electron

abstract:
  We will show that one half of the rest mass of the electron is equal to the
sum of the rest masses of electron neutrinos and that the other half of the
rest mass of the electron is given by the energy in the sum of electric
oscillations. With this composition we can explain the rest mass, the electric
charge, the spin and the magnetic moment of the electron.


title: Brownstein's Whole-Partial Derivatives: The Case of the Lorentz Gauge

abstract:
  In this brief note we show that the usual Lorentz gauge is not satisfied by
the Lienard-Wiechert potentials, then, using Brownstein's concept of
"whole-partial" derivatives we introduce the generalized expression for the
Lorentz gauge showing that it is satisfied by the LW-potentials.


title:
Discrete Lattice BGK Boltzmann Equation Computations of Transient
  Incompressible Turbulent Jets

abstract:
  In this paper, computations of transient, incompressible, turbulent, plane
jets using the discrete lattice BGK Boltzmann equation are reported. A priori
derivation of the discrete lattice BGK Boltzmann equation with a spatially and
temporally dependent relaxation time parameter, which is used to represent the
averaged flow field, from its corresponding continuous form is given. The
averaged behavior of the turbulence field is represented by the standard {\it
k-$\epsilon$} turbulence model and computed using a finite-volume scheme on
non-uniform grids. Computed results are compared with analytical solutions,
experimental data and results of other computational methods. Satisfactory
agreement is shown.


title:
Invariant imbedding theory of mode conversion in inhomogeneous plasmas:
  I. Exact calculation of the mode conversion coefficient in cold, unmagnetized
  plasmas

abstract:
  This is the first of a series of papers devoted to the development of the
invariant imbedding theory of mode conversion in inhomogeneous plasmas. A new
version of the invariant imbedding theory of wave propagation in inhomogeneous
media allows one to solve a wide variety of coupled wave equations exactly and
efficiently, even in the cases where the material parameters change
discontinuously at the boundaries and inside the inhomogeneous medium. In this
paper, the invariant imbedding method is applied to the mode conversion of the
simplest kind, that is the conversion of $p$-polarized electromagnetic waves
into electrostatic modes in cold, unmagnetized plasmas. The mode conversion
coefficient and the field distribution are calculated exactly for linear and
parabolic plasma density profiles and compared quantitatively with previous
results.


title: From Baking a Cake to Solving the Schrodinger Equation

abstract:
  The primary emphasis of this study has been to explain how modifying a cake
recipe by changing either the dimensions of the cake or the amount of cake
batter alters the baking time. Restricting our consideration to the genoise,
one of the basic cakes of classic French cuisine, we have obtained a
semi-empirical formula for its baking time as a function of oven temperature,
initial temperature of the cake batter, and dimensions of the unbaked cake. The
formula, which is based on the Diffusion equation, has three adjustable
parameters whose values are estimated from data obtained by baking genoises in
cylindrical pans of various diameters. The resulting formula for the baking
time exhibits the scaling behavior typical of diffusion processes, i.e. the
baking time is proportional to the (characteristic length scale)^2 of the cake.
It also takes account of evaporation of moisture at the top surface of the
cake, which appears to be a dominant factor affecting the baking time of a
cake. In solving this problem we have obtained solutions of the Diffusion
equation which are interpreted naturally and straightforwardly in the context
of heat transfer; however, when interpreted in the context of the Schrodinger
equation, they are somewhat peculiar. The solutions describe a system whose
mass assumes different values in two different regions of space. Furthermore,
the solutions exhibit characteristics similar to the evanescent modes
associated with light waves propagating in a wave guide. When we consider the
Schrodinger equation as a non-relativistic limit of the Klein-Gordon equation
so that it includes a mass term, these are no longer solutions.


title:
Near-field photoluminescence study of InAs/AlGaAs quantum-dot-based
  nanoclusters: band filling effect

abstract:
  We have performed near-field spectroscopy and microscopy of the InAs/AlGaAs
quantum-dot-based nanoclusters. It is observed that the photoluminescence
spectra of spatially confined excitons in the nanoclusters is blue-shifted up
to 20 meV as the power density is increased. In particular, the near-field
photoluminescence images have shown that excitons became spatially confined
gradually from lower energy state (1.4150 eV) to higher energy state (1.4392
eV) as the excitation power is increased, which is indicative of the
band-filling effect of semiconductor nanostructures.


title: Knots and Polytopes

abstract:
  A construction of polytopes is given based on integers. These geometries are
constructed through a mapping to pure numbers and have multiple applications,
including statistical mechanics and computer science. The number form is useful
in topology and has a mapping to one-dimensional knot contours.


title: Computational Derivation to Zeta Zeros and Prime Numbers

abstract:
  A route to the derivation of the numbers $s$ to the transcendental equation
$\zeta(s)=0$ is presented. The solutions to this equation require the solving
of a geodesic flow in an infinite dimensional manifold. These solutions enable
one approach to a formula generating the prime numbers.


title: Optimal supply against fluctuating demand

abstract:
  Sornette et al. claimed that the optimal supply does not agree with the
average demand, by analyzing a bakery model where a daily demand fluctuates
with a uniform distribution. In this note, we extend the model to general
probability distributions, and obtain the formula of the optimal supply for
Gaussian distribution, which is more realistic. Our result is useful in a real
market to earn the largest income on average.


title: Multi-Component Gas-Dynamics and Turbulence

abstract:
  In the article, correct method for the kinetic Boltzmann equation asymptotic
solution is formulated, the Hilbert method and the Enskog error are considered.
The equations system of multi-component nonequilibrium gas-dynamics is derived,
that corresponds to the first order in the approximate method for solution of
the kinetic Boltzmann equation within the Struminskii approach. It is shown,
that velocity distribution functions, received by the proposed method and by
the Enskog method within the Enskog approach to solving of kinetic Boltzmann
equation for gas mixture, are equivalent to first infinitesimal order terms,
but, generally speaking, differ in the next order. An interpretation of
turbulent gas flow is proposed, as stratified to components gas flow, which is
described by the derived equations system of multi-component nonequilibrium
gas-dynamics.


title:
Geometric visualization of the Brewster angle from dielectric--magnetic
  interface

abstract:
  A geometric visualization is presented for the Brewster angle for a plane
wave reflecting from an interface. The surface is assumed isotropic but it is
allowed to display both dielectric and magnetic susceptibility, and hence the
Brewster (polarizing) angle can attain any value between 0 and 90 degrees, and
can exist for both parallel and perpendicular polarizations. The geometric
construction (a tetrahedron) is spanned by the basic material parameters of the
surface. The Brewster angle appears in one of the faces of the tetrahedron.


title:
Variational description of multi-fluid hydrodynamics: Coupling to gauge
  fields

abstract:
  In this work we extend our previously developed formalism of Newtonian
multi-fluid hydrodynamics to allow for coupling between the fluids and the
electromagnetic and gravitational field. This is achieved within the convective
variational principle by using a standard minimal coupling prescription. In
addition to the conservation of total energy and momentum, we derive the
conservation of canonical vorticity and helicity, which generalize the
corresponding conserved quantities of uncharged fluids. We discuss the
application of this formalism to electrically conducting systems,
magnetohydrodynamics and superconductivity. The equations of electric
conductors derived here are more general than those found in the standard
description of such systems, in which the effect of entrainment is overlooked,
despite the fact that it will generally be present in any conducting
multi-constituent system.


title:
Exchange-correlation potentials and local energies per particle along
  non-linear adiabatic connections

abstract:
  We study non-linear adiabatic connection paths in density-functional theory
using modified electron-electron interactions that perform a
long-range/short-range separation of the Coulomb interaction. These adiabatic
connections allows to define short-range exchange-correlation potentials and
short-range local exchange-correlation energies per particle that we have
calculated accurately for the He and Be atoms and compared to the corresponding
quantities in the local density approximation (LDA). The results confirm that
the LDA better describes exchange-correlation potentials and local
exchange-correlation energies per particle when the range of the interaction is
reduced.


title:
Nonlinear dynamics of the interface of dielectric liquids in a strong
  electric field: Reduced equations of motion

abstract:
  The evolution of the interface between two ideal dielectric liquids in a
strong vertical electric field is studied. It is found that a particular flow
regime, for which the velocity potential and the electric field potential are
linearly dependent functions, is possible if the ratio of the permittivities of
liquids is inversely proportional to the ratio of their densities. The
corresponding reduced equations for interface motion are derived. In the limit
of small density ratio, these equations coincide with the well-known equations
describing the Laplacian growth.


title: Fluctuational Spacetime

abstract:
  Newton's action at a distance gravitational law and Coulomb's action at a
distance electrostatic law had to be reexamined in the light of field theories
which originated from Maxwell's electrodynamics. These ideas were further
modified with the advent of Quantum Theory, even though the differentiable
spacetime manifold of Classical Physics was retained. More recent approaches in
unifying gravitation with the other fundamental interactions has lead to a
spacetime that is not smooth. In this light we examine the nature of spacetime,
taking into consideration the role of fluctuations.


title: On the stability of Bose-Fermi mixtures

abstract:
  We consider the stability of a mixture of degenerate Bose and Fermi gases.
Even though the bosons effectively repel each other the mixture can still
collapse provided the Bose and Fermi gases attract each other strongly enough.
For a given number of atoms and the strengths of the interactions between them
we find the geometry of a maximally compact trap that supports the stable
mixture. We compare a simple analytical estimation for the critical axial
frequency of the trap with results based on the numerical solution of
hydrodynamic equations for Bose-Fermi mixture.


title:
Environment influence on the IR fluorescence of Xe$_{2}^{*}$ molecules
  in electron beam excited Ar--Xe mixture at high density

abstract:
  We report new measurements of the near infrared (NIR) Xe$_2^*$ excimer
fluorescence in an electron--beam--excited Ar (90%)--Xe (10 %) mixture at room
temperature. Previous measurements up to a density $N\approx 2\times 10^{26}$
m$^{-3}$ discovered a broad excimer fluorescence band at $\approx 7800$
cm$^{-1},$ whose center is red--shifted by increasing $N$ (A. F. Borghesani, G.
Bressi, G. Carugno, E. Conti, and D. Iannuzzi, {\em J. Chem. Phys.}, {\bf 115},
6042 (2001)). The shift has been explained by assuming that the energy of the
optical active electron in the molecule is shifted by the density--dependent
Fermi shift and by accounting for the solvation effect due to the environment.
We have extended the density range up to $N\approx 6\times 10^{26}$ m$^{-3}, $
confirming the previous measurements and extending the validity of the
interpretative model. A detailed analysis of the width of the fluorescence band
gives a value of 2.85 nm for the size of the investigated excimer state. Such a
large value lends credence to the validity of the proposed explanation of the
experimental findings.


title:
Simulation study of electron drift and gas multiplication in Micro Pixel
  Chamber

abstract:
  The physical processes of charge collection and gas multiplication of a Micro
Pixel Chamber (mu-PIC) were studied in detail using a three-dimensional
simulation. The collection efficiencies of primary electrons and gas
multiplication factors were calculated for several electrode structures. Based
on those studies, we analyzed the optimization of the electrode structure of
the mu-PIC, in order to obtain a high gas gain of more than 10^4 and a
simultaneous suppression of discharges. Consequently, we found that these
characteristics strongly depend on the substrate thickness and the anode
diameter of the mu-PIC. In addition, a gas gain of 10^5 would be expected for a
mu-PIC having a thick substrate of > 150um.


title: Strain induced half-metal to semiconductor transition in GdN

abstract:
  We have investigated the electronic structure and magnetic properties of GdN
as a function of unit cell volume. Based on the first-principles calculations
of GdN, we observe that there is a transformation in conduction properties
associated with the volume increase: first from halfmetallic to semi-metallic,
then ultimately to semiconducting. We show that applying stress can alter the
carrier concentration as well as mobility of the holes and electrons in the
majority spin channel. In addition, we found that the exchange parameters
depend strongly on lattice constant, thus the Curie temperature of this system
can be enhanced by applying stress or doping impurities.


title: A note on the stability of slip channel flows

abstract:
  We consider the influence of slip boundary conditions on the modal and
non-modal stability of pressure-driven channel flows. In accordance with
previous results by Gersting (1974) (Phys. Fluids, 17) but in contradiction
with the recent investigation of Chu (2004) (C.R. Mecanique, 332), we show that
slip increases significantly the value of the critical Reynolds number for
linear instability. The non-modal stability analysis however reveals that the
slip has a very weak influence on the maximum transient energy growth of
perturbations at subcritical Reynolds numbers. Slip boundary conditions are
therefore not likely to have a significant effect on the transition to
turbulence in channel flows.


title:
Tunable positive and negative refraction in optically-induced photonic
  lattices

abstract:
  We study tunable refraction of light in one-dimensional periodic lattices
induced optically in a photorefractive crystal. We observe experimentally both
positive and negative refraction of beams which selectively excite the first or
second spectral bands of the periodic lattice, and demonstrate tunability of
the output beam position by dynamically adjusting the lattice depth. At higher
laser intensities, the beam broadening due to diffraction can be suppressed
through nonlinear self-focusing while preserving the general steering
properties.


title: How Ampere could have derived the Lorentz Transformations

abstract:
  Lorentz Transformations of Special Relativity are derived from two
postulates: the first is the Principle of Relativity, while the postulate of
invariance of the velocity of light, used in usual derivations, is replaced by
a law of lectro-magneto-statics and invariance of electrical charge. Our
derivation does not require the assumption of regularity conditions of the
Transformations, such as linearity and continuity required by other
derivations. The level of the needed mathematics and physical concepts makes
the proposed derivation suitable for Secondary School.


title:
A Formula for Gauge Invariant Reduction of Electromagnetic Multipole
  Tensors

abstract:
  Based on some previous results, one gives a general formula for introducing
electromagnetic multipole expansions in terms of symmetric and traceless
cartesian tensors.


title: The Improbability Scale

abstract:
  The Improbability Scale (IS) is proposed as a way of communicating to the
general public the improbability (and by implication, the probability) of
events predicted as the result of scientific research. Through the use of the
Improbability Scale, the public will be able to evaluate more easily the
relative risks of predicted events and draw proper conclusions when asked to
support governmental and public policy decisions arising from that research.


title: Self-fulfilling Ising Model of Financial Markets

abstract:
  We study a dynamical Ising model of agents' opinions (buy or sell) with
coupling coefficients reassessed continuously in time according to how past
external news (magnetic field) have explained realized market returns. By
combining herding, the impact of external news and private information, we test
within the same model the hypothesis that agents are rational versus
irrational. We find that the stylized facts of financial markets are reproduced
only when agents are over-confident and mis-attribute the success of news to
predict return to herding effects, thereby providing positive feedbacks leading
to the model functioning close to the critical point.


title:
Statistical modelling of tropical cyclone tracks: a semi-parametric
  model for the mean trajectory

abstract:
  We present a statistical model for the unconditional mean tracks of
hurricanes. Our model is a semi-parametric scheme that averages together
observed hurricane displacements. It has a single parameter that defines the
averaging length scale, and we derive the optimum value for this parameter
using a jackknife. The main purpose of this model is as a starting point for
developing a statistical model of hurricanes for use in the estimation of the
wind, rainfall and flooding risks. The model also acts as an optimal filtering
tool for estimating mean hurricane tracks.


title: Perfect electromagnetic conductor

abstract:
  In differential-form representation, the Maxwell equations are represented by
simple differential relations between the electromagnetic two-forms and source
three-forms while the electromagnetic medium is defined through a constitutive
relation between the two-forms. The simplest of such relations expresses the
electromagnetic two-forms as scalar multiples of one another. Because of its
strange properties, the corresponding medium has been considered as
nonphysical. In this study such a medium is interpreted in terms of the
classical Gibbsian vectors as a bi-isotropic medium with infinite values for
its four medium parameters. It is shown that the medium is a generalization of
both PEC (perfect electric conductor) and PMC (perfect magnetic conductor)
media, with similar properties. This is why the medium is labeled as PEMC
(perfect electromagnetic conductor). Defining a certain class of duality
transformations, PEMC medium can be transformed to PEC or PMC media. As an
application, plane-wave reflection from a planar interface of air and PEMC
medium is studied. It is shown that, in general, the reflected wave has a
cross-polarized component, which is a manifestly nonreciprocal effect.


title:
Piecewise continuous distribution function method: Fluid equations and
  wave disturbances at stratified gas

abstract:
  Wave disturbances of a stratified gas are studied. The description is built
on a basis of the Bhatnagar -- Gross -- Krook (BGK) kinetic equation which is
reduced down the level of fluid mechanics. The double momenta set is introduced
inside a scheme of iterations of the equations operators, dividing the velocity
space along and opposite gravity field direction. At both half-spaces the local
equilibrium is supposed. As the result, the momenta system is derived. It
reproduce Navier-Stokes and Barnett equations at the first and second order in
high collision frequencies. The homogeneous background limit gives the known
results obtained by direct kinetics applications by Loyalka and Cheng as the
recent higher momentum fluid mechanics results of Chen, Rao and Spiegel. The
ground state declines from exponential at the Knudsen regime. The WKB solutions
for ultrasound in exponentially stratified medium are constructed in explicit
form, evaluated and plotted.


title: Electronic Fock spaces: Phase prefactors and hidden symmetry

abstract:
  Efficient technique of manipulation with phase prefactors in electronic Fock
spaces is developed. Its power is demonstrated on example of both relatively
simple classic configuration interaction matrix element evaluation and
essentially more complicated coupled cluster case. Interpretation of coupled
cluster theory in terms of a certain commutative algebra is given.


title: Werner Heisenberg (1901-1976)

abstract:
  A brief review of Heisenberg's life and work: participating in the youth
movement in the aftermath of World War I, creating quantum mechanics, conflict
with "deutsche Physik", involvement in "Hitler's Uranium Project", last
illusions. Problems and dilemmas for scientists under a dictatorship - East and
West.

categories: physics.hist-ph math-ph math.MP physics.soc-ph quant-ph


title: Electronic Fock space as associative superalgebra

abstract:
  New algebraic structure on electronic Fock space is studied in detail. This
structure is defined in terms of a certain multiplication of many electron wave
functions and has close interrelation with coupled cluster and similar
approaches. Its study clarifies and simplifies the mathematical backgrounds of
these approaches. And even more, it leads to many relations that would be very
difficult to derive using conventional technique. Formulas for action of the
creation-annihilation operators on products of state vectors are derived.
Explicit expressions for action of simplest particle-conserving products of the
creation-annihilation operators on powers of state vectors are given. General
scheme of parametrization of representable density operators of arbitrary order
is presented.


title:
MHSP in reversed-biased operation mode for ion blocking in gas-avalanche
  multipliers

abstract:
  We present recent results on the operation of gas-avalanche detectors
comprising a cascade of gas electron multipliers (GEMs) and Micro-Hole and
Strip Plates (MHSPs) multiplier operated in reversed-bias (R-MHSP) mode. The
operation mechanism of the R-MHSP is explained and its potential contribution
to ion-backflow (IBF) reduction is demonstrated. IBF values of 4E-3 were
obtained in cascaded R-MHSP and GEM multipliers at gains of about 1E+4, though
at the expense of reduced effective gain in the first R- MHSP multiplier in the
cascade.


title: Simulation for competition of languages with an ageing sexual population

abstract:
  Recently, individual-based models originally used for biological purposes
revealed interesting insights into processes of the competition of languages.
Within this new field of population dynamics a model considering sexual
populations with ageing is presented. The agents are situated on a lattice and
each one speaks one of two languages or both. The stability and quantitative
structure of an interface between two regions, initially speaking different
languages, is studied. We find that individuals speaking both languages do not
prefer any of these regions and have a different age structure than individuals
speaking only one language.


title: Sznajd model and its applications

abstract:
  In 2000 we proposed a sociophysics model of opinion formation, which was
based on trade union maxim "United we Stand, Divided we Fall" (USDF) and latter
due to Dietrich Stauffer became known as the Sznajd model (SM). The main
difference between SM compared to voter or Ising-type models is that
information flows outward. In this paper we review the modifications and
applications of SM that have been proposed in the literature.


title:
Observation and absolute frequency measurements of the 1S0 - 3P0 optical
  clock transition in ytterbium

abstract:
  We report the direct excitation of the highly forbidden (6s^2) 1S0 - (6s6p)
3P0 optical transition in two odd isotopes of ytterbium. As the excitation
laser frequency is scanned, absorption is detected by monitoring the depletion
from an atomic cloud at ~70 uK in a magneto-optical trap. The measured
frequency in 171Yb (F=1/2) is 518,295,836,593.2 +/- 4.4 kHz. The measured
frequency in 173Yb (F=5/2) is 518,294,576,850.0 +/- 4.4 kHz. Measurements are
made with a femtosecond-laser frequency comb calibrated by the NIST cesium
fountain clock and represent nearly a million-fold reduction in uncertainty.
The natural linewidth of these J=0 to J=0 transitions is calculated to be ~10
mHz, making them well-suited to support a new generation of optical atomic
clocks based on confinement in an optical lattice.


title: On Holmboe's instability for smooth shear and density profiles

abstract:
  The linear stability of a stratified shear flow for smooth density profiles
is studied. This work focuses on the nature of the stability boundaries of
flows in which both Kelvin-Helmholtz and Holmboe instabilities are present. For
a fixed Richardson number the unstable modes are confined to finite bands
between a smallest and a largest marginally unstable wavenumber. The results in
this paper indicate that the stability boundary for small wavenumbers is
comprised of neutral modes with phase velocity equal to the maximum/minimum
wind velocity whereas the other stability boundary, for large wavenumbers, is
comprised of singular neutral modes with phase velocity in the range of the
velocity shear. We show how these stability boundaries can be evaluated without
solving for the growth rate over the entire parameter space as was previously
done. The results indicate further that there is a new instability domain that
has not been previously noted in the literature. The unstable modes, in this
new instability domain, appear for larger values of the Richardson number and
are related to the higher harmonics of the internal gravity wave spectrum.


title: Application of noise level estimation for portfolio optimization

abstract:
  Time changes of noise level at Warsaw Stock Market are analyzed using a
recently developed method basing on properties of the coarse grained entropy.
The condition of the minimal noise level is used to build an efficient
portfolio. Our noise level approach seems to be a much better tool for risk
estimations than standard volatility parameters. Implementation of a
corresponding threshold investment strategy gives positive returns for
historical data.


title: Low background techniques for the Borexino nylon vessels

abstract:
  Borexino is an organic liquid scintillator underground detector for low
energy solar neutrinos. The experiment has to satisfy extremely stringent low
background requirements. The thin nylon spherical scintillator containment
vessel has to meet cleanliness and low radioactivity levels second only, within
the detector, to the scintillator itself. Overall, the background from the
vessel in the fiducial volume of the detector must be kept at the level of one
event per day or better. The requirements, design choices, results from
laboratory tests, and fabrication techniques that have been adopted to meet
this goal are presented. Details of the precautions taken during the
installation of the vessels inside the Borexino detector are also discussed.


title:
Theoretical Study of Pressure Broadening of Lithium Resonance Lines by
  Helium Atoms

abstract:
  Quantum mechanical calculations are performed of the emission and absorption
profiles of the lithium 2s-2p resonance line under the influence of a helium
perturbing gas. We use carefully constructed potential energy surfaces and
transition dipole moments to compute the emission and absorption coefficients
at temperatures from 200 to 3000 K at wavelengths between 500 nm and 1000 nm.
Contributions from quasi-bound states are included. The resulting red and blue
wing profiles are compared with previous theoretical calculations and with an
experiment, carried out at a temperature of 670 K.


title: Neutron Stars

abstract:
  This short encyclopedia article, reviewing current information on neutron
stars, is intended for a broad scientific audience.


title:
High-contrast dark resonance on the D2 - line of 87Rb in a vapor cell
  with different directions of the pump - probe waves

abstract:
  We propose a novel method enabling to create a high-contrast dark resonance
in the 87Rb vapor D2-line. The method is based on an optical pumping of atoms
into the working states by a two-frequency, linearly-polarized laser radiation
propagating perpendicularly to the probe field. This new scheme is compared to
the traditional scheme involving the circularly-polarized probe beam only, and
significant improvement of the dark resonance parameters is found. Qualitative
considerations are confirmed by numerical calculations.


title: Dynamic Behaviors of Mix-game Model and Its Applications

abstract:
  This paper proposes a modification to Minority Game (MG) by adding some
agents who play majority game into MG. So it is referred to as mix-game. The
highlight of this model is that the two groups of agents in mix-game have
different bounded abilities to deal with history information and to count their
own performance. Through simulations, this paper finds out that the local
volatilities change a lot by adding some agents who play majority game into MG,
and the change of local volatilities largely depends on different combinations
of history memories of the two groups. Furthermore this paper analyses the
underlying mechanisms for this finding. It also gives an example of
applications of mix-game.


title:
The Quantitative Relations between Stock Prices and Quantities of
  Tradable Stock Shares and Its Applications

abstract:
  This paper analyzes the quantitative relations between stock prices and
quantities of tradable stock shares in Chinese stock markets at six time points
by means of Exploratory Data Analysis (EDA) method. It is found the resulting
formulae have the same structure but different parameters. This paper also uses
these relationships in order to analyse the feasibility of policies for Chinese
Government to sell the state-owned shares in Chinese stock markets.


title: Observation of attraction between dark solitons

abstract:
  We demonstrate a dramatic change in the interaction forces between dark
solitons in nonlocal nonlinear media. We present what we believe is the first
experimental evidence of attraction of dark solitons. Our results indicate that
attraction should be observable in other nonlocal systems, such as
Bose-Einstein condensates with repulsive long-range interparticle interaction.


title:
Comparing omnidirectional reflection from periodic and quasiperiodic
  one-dimensional photonic crystals

abstract:
  We determine the range of thicknesses and refractive indices for which
omnidirectional reflection from quasiperiodic multilayers occurs. By resorting
to the notion of area under the transmittance curve, we assess in a systematic
way the performance of the different quasiperiodic Fibonacci multilayers.


title: Power laws and self-similar behavior in negative ionization fronts

abstract:
  We study anode-directed ionization fronts in curved geometries. When the
magnetic effects can be neglected, an electric shielding factor determines the
behavior of the electric field and the charged particle densities. From a
minimal streamer model, a Burgers type equation which governs the dynamics of
the electric shielding factor is obtained. A Lagrangian formulation is then
derived to analyze the ionization fronts. Power laws for the velocity and the
amplitude of streamer fronts are observed numerically and calculated
analytically by using the shielding factor formulation. The phenomenon of
geometrical diffusion is explained and clarified, and a universal self-similar
asymptotic behavior is derived.


title: Modeling of a Resonant Tunneling Diode Optical Modulator

abstract:
  The integration of a double barrier resonant tunneling diode within a
unipolar optical waveguide provides electrical gain over a wide bandwidth. Due
to the non-linearities introduced by the double barrier resonant tunneling
diode an unipolar InGaAlAs/InP optical waveguide can be employed both as
optical modulator and optical detector. The modeling results of a device
operating as optical modulator agree with preliminary experimental data,
foreseeing for an optimized device modulation depths up to 23 dB with chirp
parameter between -1 and 0 in the wavelength range analyzed (1520 nm - 1600
nm).


title:
Societal and ethical interactions with nanotechnology ("SEIN") -- an
  introduction

abstract:
  We identify 6 important issues tied to the continued development of
nantechnology: (1) environmental issues, (2) equity issues relating to the
possible emergence of a "nanodivide", (3) legal, regulatory and insurance
challenges, (4) privacy issues, (5) the interaction between nanomedicine and
medical issues and (6) "hypertechnology, or the pace of nanotechnological
change. We conclude that continued efforts are needed to build upon an emerging
inclusice dialogue engaging all of nano's stakeholders - from various publics
to entrepreneurs, industrialists, venture capitalists, scientists and
engineers-to ensure a mutually beneficial relationship between nanotechnology
and society.


title: On the problem of Zitterbewegung of the Dirac electron

abstract:
  Reformulation of Dirac equation in terms of real quadratic division algebra
of quaternions is given. Similar equations with different mass term are
identified as suitable for description of free propagating quark motion. The
complete orthonormal set of the positive-energy plane wave solutions is
presented. Therefore, Zitterbewegung phenomenon is absent in this formulation.
The probability current is proportional to the momentum, as in standard
Schrodinger wave mechanics.


title: Characteristics of the Korean stock market correlations

abstract:
  In this study, we establish a network structure of the Korean stock market,
one of the emerging markets, with its minimum spanning tree through the
correlation matrix. Base on this analysis, it is found that the Korean stock
market doesn't form the clusters of the business sectors or of the industry
categories. When the MSCI (Morgan Stanley Capital International Inc.) index is
exploited, we found that the clusters of the Korean stock market is formed.
This finding implicates that the Korean market, in this context, is
characteristically different form the mature markets.


title: Design of beam splitters and microlasers using chaotic waveguides

abstract:
  We consider waveguides formed by single or multiple two-dimensional chaotic
cavities connected to leads. The cavities are chaotic in the sense that the ray
(or equivalently, classical particle) dynamics within them is chaotic.
Geometrical parameters are chosen to produce a mixed phase space (chaotic
regions surrounding islands of stability where motion is regular). Incoming
rays (or particles) cannot penetrate into these islands but incoming plane
waves dynamically tunnel into them at a certain discrete set of frequencies
(energies). The support of the corresponding quasi-bound states is along the
trajectories of periodic orbits trapped within the cavity. We take advantage of
this difference in the ray/wave behavior to demonstrate how chaotic waveguides
can be used to design beam splitters and microlasers. We also present some
preliminary experimental results in a microwave realization of such chaotic
waveguide.


title: Design of switches and beam splitters using chaotic cavities

abstract:
  We propose the construction of electromagnetic (or electronic) switches and
beam splitters using chaotic two-dimensional multi-port waveguides. A prototype
two-port waveguide is locally deformed in order to produce a ternary incomplete
horseshoe proper of mixed phase space (chaotic regions surrounding islands of
stability where motion is regular). Due to tunneling to the phase space
stability islands the appearance of quasi-bound states (QBS) is induced. Then,
we attach transversal ports to the waveguide on the deformation region in
positions where the phase space structure is only slightly perturbed. We show
how QBS can be guided out of the waveguide through the attached transversal
ports giving rise to frequency selective switches and beam splitters.


title: Autocatalytic reaction front in a pulsative periodic flow

abstract:
  Autocatalytic reaction fronts between reacted and unreacted species may
propagate as solitary waves, namely at a constant front velocity and with a
stationary concentration profile, resulting from a balance between molecular
diffusion and chemical reaction. A velocity field in the supporting medium may
affect the propagation of such fronts through different phenomena: convection,
diffusion enhancement, front shape changes... We report here on an experimental
study and lattice BGK numerical simulations of the effect of an oscillating
flow on the autocatalytic reaction between iodate and arsenous acid in a
Hele-Shaw cell. In the low frequency range covered by the experiments, the
front behavior is controlled by the flow across the gap and can be reproduced
with 2D numerical simulations. An analytical solution is also derived under the
condition of a weak flow velocity, and is found to be in reasonable agreement
with our data.


title: Progress on indium and barium single ion optical frequency standards

abstract:
  We report progress on 115In+ and 137Ba+ single ion optical frequency
standards using all solid-state sources. Both are free from quadrupole field
shifts and together enable a search for drift in fundamental constants.


title: Hausdorff clustering of financial time series

abstract:
  A clustering procedure, based on the Hausdorff distance, is introduced and
tested on the financial time series of the Dow Jones Industrial Average (DJIA)
index.


title:
Measurement of the cell membrane capacitance and conductance of colonic
  crypt cells of the rat using the patch clamp technique

abstract:
  Using the patch clamp technique the membrane capacitance and membrane
conductance of colonic crypt cells of the rat was measured. The influence of
the intracellular agonists Ca++, cAMP and of osmotic changes on the membrane
capacitance and conductance was studied.