bluuebunny/crossref_metadata_2025 huggingface dataset:
New multiplicities of dreaming and REMing
Authors: Hunt Harry T.
Published: July 2002

The five authors vary in the degree to which the recent neuroscience of the REM state leads them towards multiple dimensions and forms of dreaming consciousness (Hobson et al.; Nielsen; Solms) or toward all-explanatory single factor models (Vertes & Eastman, Revonsuo). The view of the REM state as a prolongation of the orientation response to novelty fits best with the former pluralisms but not the latter monisms.

[Hobson et al.; Nielsen; Revonsuo; Solms; Vertes & Eastman]
Dream science 2000: A response to commentaries on Dreaming and the brain
Authors: Hobson J. Allan , Pace-Schott Edward F. , Stickgold Robert
Published: July 2002

Definitions of dreaming are not required to map formal features of mental activity onto brain measures. While dreaming occurs during all stages of sleep, intense dreaming is largely confined to REM. Forebrain structures and many neurotransmitters can contribute to sleep and dreaming without negating brainstem and aminergic-cholinergic control mechanisms. Reductionism is essential to science and AIM has considerable heuristic value. Recent findings support sleep's role in learning and memory. Emerging technologies may address long-standing issues in sleep and dream research.
Evolving null hypotheses and the base rate fallacy: A functional interpretation of scientific myth
Authors: Gibbs Brian J.
Published: July 2002

The meaning of an experimental result depends on the
experiment's conceptual backdrop, particularly its null
hypothesis. This observation provides the basis for a functional
interpretation of belief in the base rate fallacy. On this
interpretation, if the base rate fallacy is to be labelled a
“myth,” then it should be recognized that this
label is not necessarily a disparaging one.
Evolution might select constructivism
Authors: Hurford James , Joseph Sam , Kirby Simon , Reid Alastair
Published: July 2002

There is evidence for increase, followed by decline, in
synaptic numbers during development. Dendrites do not function in
isolation. A constructive neuronal process may underpin a selectionist
cognitive process. The environment shapes both ontogeny and phylogeny.
Phylogenetic natural selection and neural selection are compatible.
Natural selection can yield both constructivist and selectionist
solution to adaptuive problems.
Self-deception and the desire to believe
Authors: Lazar Ariela
Published: July 2002

This commentary concentrates on two flaws in
Mele's account. The first is Mele's attempt to
account for self-deception by appealing to a desire to believe,
together with an instrumental belief concerning the means of
satisfying this desire. Contrary to Mele, it is argued that such an
account requires a recognition on the part of agents that their
actions instantiate these means. Second, Mele misidentifies the
most essential – and flawed – ingredient of the
standard approach to self-deception, the agent's desire
to form the belief (the belief that is undermined by the evidence).
This ingredient is retained in Mele's own account of
self-deception.
Atran's biodiversity parser: Doubts about hierarchy and autonomy
Authors: Hunn Eugene S.
Published: July 2002

Atran argues that an autonomous ethnobiological
information-processing module exists. This module imputes
a “deep causal essence” to folk-biological taxa
and uses a hierarchy of taxonomic ranks. I argue that Atran's
own data suggest that rank is not an essential feature of the
ethnobiological module, and that ethnobiological causal essences
may be generalized to other domains and vice versa, limiting its
autonomy.
Indices of program-level comprehension
Authors: Want Stephen C. , Harris Paul L.
Published: July 2002

Byrne & Russon suggest that the production of action
by primates is hierarchically organised. We assess the evidence for
hierarchical structure in the comprehension of action by primates.
Focusing on work with human children we evaluate several possible
indices of program-level comprehension.
Individuals, properties, and the explicitness hierarchy
Authors: Barber Alex
Published: July 2002

The scenario used by Dienes & Perner to show that individual
representation can be implicit when property representation is explicit
can be adapted to show that property representation can be implicit when
individual representation is explicit. So there is no hierarchy of
explicitness, contrary to their claim. There is a reading of the
“implicit/explicit” distinction that does appear to exhibit
an asymmetry parallel to that alleged to hold between individual and
property. But this is not a distinction Dienes & Perner mention,
nor is it one that could be easily incorporated into their framework.
Does the hand reflect implicit knowledge? Yes and no
Authors: Goldin-Meadow Susan , Alibali Martha Wagner
Published: July 2002

Gesture does not have a fixed position in the Dienes &
Perner framework. Its status depends on the way knowledge is expressed.
Knowledge reflected in gesture can be fully implicit (neither factuality
nor predication is explicit) if the goal is simply to move a pointing
hand to a target. Knowledge reflected in gesture can be explicit (both
factuality and predication are explicit) if the goal is to indicate an
object. However, gesture is not restricted to these two extreme
positions. When gestures are unconscious accompaniments to speech and
represent information that is distinct from speech, the knowledge they
convey is factuality-implicit but predication-explicit.
Conversation and community: Chat in a virtual world. Lynn Cherny. Stanford,
CA: CSLI Publications, 1999. Pp. 369.
Authors: Locke John L.
Published: July 2002

In the early 1990s, Lynn Cherny spent much of her time in the MUD – not mired in
wet earth, but actively exploring “Multi-User Dungeons.” These “fictional
universes with a focus on role-playing,” as they are defined in the Introduction, enable
groups of Internet-connected individuals to assemble in cyberspace, communicating by way of
sequentially typed text. Later, as a doctoral student in linguistics at Stanford, Cherny decided to
study ethnographically – that is, from the perspective of one methodically and
dispassionately observing a different race – the expressive practices of those habitually
using this strange new modality.
Signal to syntax: Bootstrapping from speech to grammar in early acquisition.
James L. Morgan and Katherine Demuth (Eds.). Mahwah, NJ: Erlbaum, 1996. Pp. 487.
Authors: Levelt Clara C.
Published: July 2002

In February 1993, a conference was organized at Brown University, Providence, RI, where an
interesting mélange of theoretical linguists, computer scientists, acousticians,
psycholinguists, and cognitive scientists discussed issues bearing on how children's
perception and representation of the speech stream may contribute to the acquisition of syntax.
The contents of the current volume are based on the proceedings of this conference.
Ergodic properties of infinite measure-preserving interval maps with indifferent fixed points
Authors: ZWEIMÜLLER ROLAND
Published: July 2002

We consider piecewise twice differentiable maps $T$ on $[0,1]$ with indifferent fixed points giving rise to infinite invariant measures, and we study their behaviour on ergodic components. As we do not assume the existence of a Markov partition but only require the first image of the fundamental partition to be finite, we use canonical Markov extensions to first prove pointwise dual-ergodicity, which, together with an identification of wandering rates, leads to distributional limit theorems. We show that $T$ satisfies Rohlin's formula and prove a variant of the Shannon–McMillan–Breiman theorem. Moreover, we give a stronger limit theorem for the transfer operator providing us with a large collection of uniform and Darling–Kac sets. This enables us to apply recent results from fluctuation theory.
${\bi T},{\bi T}^{\bf -1}$ is not standard
Authors: HEICKLEN DEBORAH , HOFFMAN CHRISTOPHER
Published: July 2002

A sequence of random variables, $Y_0,Y_1,Y_2,\ldots\,$, is called standard if there exists a one-sided isomorphism between it and a sequence of independent random variables. In this paper it is demonstrated that the sequence arising from the past of the $T,T^{-1}$ map is not standard.
Describing quadratic Cremer point polynomials by parabolic perturbations
Authors: SØRENSEN DAN ERIK KRARUP
Published: July 2002

We describe two infinite-order parabolic perturbation procedures yielding quadratic polynomials having a Cremer fixed point. The main idea is to obtain the polynomial as the limit of repeated parabolic perturbations. The basic tool at each step is to control the behaviour of certain external rays.

Polynomials of the Cremer type correspond to parameters at the boundary of a hyperbolic component of the Mandelbrot set. In this paper we concentrate on the main cardioid component. We investigate the differences between two-sided (i.e. alternating) and one-sided parabolic perturbations.

In the two-sided case, we prove the existence of polynomials having an explicitly given external ray accumulating both at the Cremer point and at its non-periodic preimage. We think of the Julia set as containing a ‘topologist's double comb’.

In the one-sided case we prove a weaker result: the existence of polynomials having an explicitly given external ray accumulating at the Cremer point, but having in the impression of the ray both the Cremer point and its other preimage. We think of the Julia set as containing a ‘topologist's single comb’.

By tuning, similar results hold on the boundary of any hyperbolic component of the Mandelbrot set.
Class (in Place) Without Capitalism (in Space)?
Authors: Kalb Don
Published: July 2002

Geoff Eley and Keith Nield embrace an institutional perspective
à la Ira Katznelson, but they do so with a much stronger
emphasis on popular alliance formation and social movements than Katznelson.
Social history's role, in their vision, would consist of capturing the
dynamics of stability and change in densely and intensively studied local
contexts. It is the injustices embedded in such contexts that apparently feed
these movements and alliances. Class is thus reduced to a microheuristic of
hidden injuries and subaltern identities. However, the concept of social class
can only help to articulate a position beyond formal institutionalism and the
class language of bipolarity when it is wedded to a nonreductionist,
nonessentialist, and nonfinalist theory of capitalism. Seen from this
perspective, capitalism is a worldwide and world- embedded process of combined
and uneven development that constantly assembles and disassembles the materials
from which human communities are made. In short, if we want to rethink class in
place, we need to rethink capitalism in space.
The liberal-communitarian debate in contemporary political philosophy and its significance for international relations
Authors: MORRICE DAVID
Published: July 2002

This article examines the debate between liberalism and communitarianism in
contemporary political philosophy and considers its significance for international relations.
The debate tends to pose a false dichotomy between liberalism and communitarianism, and
neither position alone can provide an adequate basis for international relations theory. It is
necessary to go beyond the liberal-communitarian divide in order to reconcile the valuable
insights that may be rescued from both positions. There is a community which is a moral
reality, which includes all individuals and maintains their moral integrity, and which can
accommodate all legitimate, smaller communities. This is the community of humanity, which
is recognized in traditional theories of natural law and the law of nations. The article
concludes by considering whether the universal community of humanity requires and justifies
world government.
Conflicting authorities: states, currency markets and the ERM crisis of 1992–93
Authors: AYKENS PETER
Published: July 2002

The concept of authority has recently received heightened attention in the international politics literature. Unfortunately, considerable confusion still exists regarding who possesses authority, how authority is constituted, how it erodes and how it differs from other means of generating compliance, most notably power. Drawing on work from international political economy and political theory, this article sets out to clarify some of the many ambiguities surrounding authority. It builds hypotheses regarding state/market authority relations and tests these hypotheses in the context of the Exchange Rate Mechanism (ERM) crisis of 1992–93. The article concludes that the ERM crisis did not represent a mere ‘bump in the road’ on the way to European Monetary Union, but rather the break-up of policy consensus in a dramatic way.
Charles Townes, How the Laser Happened: Adventures of a
Scientist, Oxford University Press, New York, 1999. 256 pp.
ISBN: 0-19-5122268-2.
Authors: Hora Heinrich
Published: July 2002

All of mankind, not only the readers of this Journal,
is now fascinated by the laser. The process of many preceding
physics discoveries beginning with Einstein (Zürich
lecture, printed 1916, see A. Held, General Relativity
and Gravitation One Hundred Years after the Birth of Einstein,
Plenum, New York, 1980, Vol. 1, p. 17–21) and how
this earth shattering discovery was not recognized by the
giants in science is really a process of “how it
happened” and the fact is: Charles Townes is its
creator. Since there were some dark clouds through which
this discovery of our century (next to the quantum theory
and the theory of relativity) had to finally shine through,
it is a revelation to now read what its creator has to
say; modest, quiet, but true and fascinating.
Nonequilibrium laser-produced plasma of volume-structured
media and ICF applications
Authors: GUS'KOV S.Yu. , GROMOV A.I. , MERKUL'EV Yu.A. , ROZANOV V.B. , NIKISHIN V.V. , TISHKIN V.F. , ZMITRENKO N.V. , GAVRILOV V.V. , GOL'TSOV A.A. , KONDRASHOV V.N. , KOVALSKY N.V. , PERGAMENT M.I. , GARANIN S.G. , KIRILLOV G.A. , SUKHAREV S.A. , CARUSO A. , STRANGIO C.
Published: July 2002

This paper is devoted to the investigation of powerful
laser pulse interaction with regularly and statistically
volume-structured media with near critical average density
and properties of laser-produced plasma of such a media.
The results of the latest experiments on laser pulse interaction
with plane foam targets performed on Nd-laser facilities
“ABC” in the ENEA-EURATOM Association (Frascati,
Italy) and “MISHEN” in the Troitsk Institute
of Innovation Thermonuclear Investigations (TRINITI, Troitsk
Russia), and J-laser “ISKRA-4” in the Russian
Federal Nuclear Center, All-Russian Scientific Research
Institute of Experimental Physics (RFNC-VNIIEF, Sarov,
Russia) are presented and analyzed. High efficiency of
the internal volume absorption of laser radiation in the
foams of supercritical density was observed, and the dynamics
of absorbing region formation and velocity of energy transfer
process versus the parameters of porous matter
are found. Some inertial confinement fusion (ICF) applications
based on nonequilibrium properties of laser-produced plasma
of a foam and regularly structured media such as the powerful
neutron source with yield of 109–1011
DT-neutrons per 1 J of laser energy, laser-produced X-ray
generation in high temperature supercritical plasma, and
the compact ICF target absorbers providing effective smoothing
and ablation are proposed.
Laser uniformity and hydrodynamic stability experiments
at the OMEGA laser facility
Authors: BOEHLY T.R. , BABUSHKIN A. , BRADLEY D.K. , CRAXTON R.S. , DELETTREZ J.A. , EPSTEIN R. , KESSLER T.J. , KNAUER J.P. , McCRORY R.L. , McKENTY P.W. , MEYERHOFER D.D. , REGAN S. , SEKA W. , SKUPSKY S. , SMALYUK V.A. , TOWN R.P.J. , YAAKOBI B.
Published: July 2002

Experiments to demonstrate the effects of various
beam-smoothing techniques have been performed on the 60-beam,
30-kJ UV OMEGA laser system. These include direct measurements
of the effect beam-smoothing techniques have on laser beam
nonuniformity and on both planar and spherical targets.
Demonstrated techniques include polarization smoothing
and “dual-tripler” third-harmonic generation
required for future broad bandwidth (∼1 THz) smoothing
by spectral dispersion (SSD). The effects of improvements
in single-beam uniformity are clearly seen in the target-physics
experiments, which also show the effect of the laser pulse
shape on the efficacy of SSD smoothing. Saturation of the
Rayleigh-Taylor (RT) growth of the broad-bandwidth features,
in agreement with the Haan model (Haan, 1989), produced
by laser imprinting has also been observed.
Control of Rayleigh–Taylor instabilities in laser
accelerated seeded targets
Authors: DESAI T. , PANT H.C.
Published: July 2002

It is important to ameliorate the early time imprinting
of nonuniformities due to laser radiation or target shell
surface in an inertial confinement fusion (ICF) scheme.
However, they will not prevent the instabilities which
originate at the ablation surface due to acceleration of
high density plasma by low density plasma. One of the methods
discussed here is to combat the growth of instabilities
at the ablation surface. The present work is aimed to control
growth of hydrodynamic instability in laser irradiated
target at moderate intensities. Laser (λ = 1.06 μm)
radiation was focused on the plastic (base) target seeded with
microinclusions of Al and Au at various concentrations. Targets
had planar geometry and were of few microns in thickness. The
target stability was studied using the optical backlighting technique. Shadowgrams of the seeded targets show a uniform motion of the target
rear, whereas pure plastic targets break up under identical
conditions. Results are analyzed by considering the X-radiation
transport, coherent structure effects of the plasma like
vortices, self-generated magnetic field in the accelerated
target, and nonlinear conversion of long wavelength perturbation
into short wavelength perturbation.
Experimental investigation into the interaction of the stationary
shock wave with the turbulent layer
Authors: PAVLENKO A.V. , BAISHEV A.I. , KUCHERENKO Yu.A. , LITVIN A.T. , SOROKATYI N.N.
Published: July 2002

The method for providing the contact surface of gases to study
the Richtmyer–Meshkov and Rayleigh–Taylor instabilities
development with the P-membrane being destroyed forcedly is
proposed. At the membrane destruction, the plane turbulent layer
determining the initial and boundary conditions for the gravitational
instabilities development is formed. For the shock tube OSA, the
initial stage of the development of the turbulent layer from the
P-membrane, after the interaction with a stationary shock
wave (Ms = 1.81) has been investigated.
Status of laser fusion research at VNIIEF (Arzamas-16)
Authors: KIRILLOV G.A. , KOCHEMASOV G.G. , BESSARAB A.V. , GARANIN S.G. , MKHITARIAN L.S. , MURUGOV V.M. , SUKHAREV S.A. , ZHIDKOV N.V.
Published: July 2002

Review of some research into laser thermonuclear fusion
carried out in Russian Federal Nuclear Center (RFNC-VNIIEF)
within the last several years is presented. The review
begins with a brief survey into ICF development in RFNC-VNIIEF
starting from A.D. Sakharov and S.B. Kormer's pioneer
proposals of the 1960s. The review concludes with the exposition
of historical background of the 10 TW ISKRA-4 and 100 TW
ISKRA-5 laser facilities creation and with the prospects
of the 300 kJ ISKRA-6 (λ= 0.35 μm) laser
development. The results of survey carried out at the ISKRA-5
facility are presented in the review. The high degree of symmetry
(nonuniformity < 3%) of irradiation of a DT-shell by the X-ray
emission made it possible to successfully conduct experiments
with the asymmetrical shells. The asymmetry was effected through
the asymmetrical Mg layers deposition on a spherically uniform
glass shell surface. The asymmetry impact on neutron yield and
the moment of neutron generation was investigated. The line
X-ray emission characteristics of the H-like and He-like
Ar, Fe, and Al ions were studied in another set of experiments.
Ar was doped into DT-gas, while Fe and Al were deposited
on the CH spherical hohlraums' inner surface. Development
of the Cherenkov radiation generator in which the electron
motion is actuated by the faster-than-light X-ray pulse
motion on the surface of a plane sample, being under voltage,
is reported. And in fine a brief description of experiments
carried out at the ISKRA-4 facility under the program of
turbulent mixing in plane multi layer targets is presented.
Numerical simulation of spontaneous magnetic fields in laser
produced plasma jet using MAG code
Authors: DIYANKOV O.V. , GLAZYRIN I.V. , KOSHELEV S.V. , LIKOV V.A.
Published: July 2002

The results of numerical simulation of spontaneous
magnetic field generation and the influence of this field
on laser produced plasma jet expansion in vacuum and low
density gas are presented. The numerical simulation has
been carried out using 2D MHD code for the case of an Al
plate of 5 μm thickness irradiated by an Nd laser.
The laser pulse duration was 0.5 ns at half-width, laser
irradiation intensity was up to 1013 W/cm2
and laser focal spot diameter was about 100 μm. According
to the received results, the magnetic field amplitude achieves
the value of 150 kGs. This fact has no considerable influence
on the temperature maximum in laser produced plasma, but
significantly affects the process of the energy transport
from plasma jet to low density gas. Shock wave generated
magnetic field with reversal profile can be achieved in
the case of plasma propagating into background gas.
Operating characteristics of the low energy accelerator
Authors: EL-BAKI M.M. ABD , EL-RAHMAN M.M. ABD
Published: July 2002

The main purpose of this work is to describe the
construction and operation of the low energy accelerator
with energy in the range from (zero to 100 KeV). This accelerator
includes an ion source of the cold cathode Penning type
(with pierce geometry for ion beam extraction), an accelerating
tube (with 8 electrodes) and Faraday cup (FC) for measuring
ion current. A vacuum system which gives vacuum of the
order 3.0 × 10−8 Torr is used. A
palladium tube is used to supply the source with pure hydrogen
atoms. It was possible to operate this accelerator with
an energy 50 KeV at minimum hydrogen pressure, 6.3 ×
10−6 Torr. The total resistance applied
between the accelerating electrodes RT
= 31.5 MΩ. These data include the influence of the
pressure in the accelerating tube, the magnetic field of
the ion source, the extraction potential and the accelerating
potential on the collector ion current. It was possible
to accelerate protons with an energy 50 KeV with current
about 100 μA at pressure 6.3 × 10−6
Torr, the source magnetic field = 110 G (IB
= 2 A), the arc current = 0.4 A and the extraction potential = 10 KV.
Guest Editor's Preface: ULIA-1 Conference
Authors: Gizzi Leonida A.
Published: July 2002

The ULIA-1 Conference, a scientific initiative of
Antonio Giulietti, was the first of the ULIA Euroconferences
Series, from the Istituto di Fisica Atomicae Molecolare
(IFAM), Pisa, Italy. It was held in Elounda, Crete, Greece,
May 7-11, 1999, one of the most attractive Mediterranean
spots, characterized by beautiful surroundings rich with
suggestions of the ancient Minoan civilization.
Coherence properties of high-order harmonics: Application
to high-density laser–plasma diagnostic
Authors: MERDJI H. , SALIÈRES P. , LE DÉROFF L. , HERGOTT J.-F. , CARRÉ B. , JOYEUX D. , DESCAMPS D. , NORIN J. , LYNGÅ C. , L'HUILLIER A. , WAHLSTRÖM C.-G. , BELLINI M. , HULLER S.
Published: July 2002

We present two interferometry schemes in the extreme
ultraviolet, based on either the wave-front division of
a unique harmonic beam (1st scheme) or two spatially
separated, phase-locked harmonic sources (2nd
scheme). In the first scheme using a Fresnel bimirror interferometer,
we measure the degree of spatial coherence of the 13th
harmonic generated in xenon, as a function of different
parameters. A high degree of coherence, larger than 0.5,
is found for the best conditions in almost the full section
of the beam. Then, we demonstrate that the second scheme
can be used for interferometry measurements with an ultrahigh
time resolution. The 11th harmonic is used to
study the spatial variation of the electron density of
a laser-produced plasma. Electronic densities higher than
2.1020 cm−3 are measured.
Particle acceleration by ultraintense laser interactions
with beams and plasmas
Authors: NAKAJIMA KAZUHISA
Published: July 2002

Recently, there has been great interest growing in ultrahigh
field particle acceleration driven by ultraintense laser
interactions with beams and plasmas. Although numerous
concepts of particle acceleration by laser fields have been
proposed almost since the beginning of the laser evolution,
there has been tremendous progress in recent years on their
theoretical and experimental aspects owing to advances in
the generation of ultraintense short laser pulses. The
laser–plasma accelerator concepts are reviewed on
the laser wakefield acceleration mechanism. In particular,
the electron acceleration by the laser wakefield in plasmas
is illustrated by our recent experimental results, including
the propagation of the ultrashort intense laser pulses
in plasmas.
Phase effects in two-photon free–free transitions
in a bichromatic field of frequencies ω and 3ω
Authors: CIONGA A. , ZLOH G.
Published: July 2002

The effect of the relative phase between the components of a
bichromatic field of frequencies ω and 3ω is discussed
in the case of free–free transitions in laser-assisted
electron-hydrogen scattering. For fast projectile and low
field intensities, the role of target dressing is pointed out.
Liquid-metal targets for high-power applications: Pulsed
heating and shock hydrodynamics
Authors: HASSANEIN AHMED
Published: July 2002

Significant interest has recently focused on the use
of liquid-metal targets flowing with high velocities for
various high-power nuclear and high-energy physics applications
such as fusion reactor first-walls, the Spallation Neutron
Source, Isotope Separation On Line, and Muon Collider projects.
This is because the heat generated in solid targets due
to beam or plasma bombardment cannot be removed easily
and the resulting thermal shock damage could be a serious
lifetime problem for long-term operation. More recently,
the use of free or open flying-liquid jets has been proposed
for higher-power-density applications. The behavior of
a free-moving liquid mercury or gallium jet subjected to
proton beam deposition in a strong magnetic field has been
modeled and analyzed for the Muon Collider project. Free-liquid-metal
jets can offer significant advantages over conventional
solid targets, particularly for the more demanding and
challenging high-power applications. However, the use of
free-moving liquid-metal targets raises a number of new
and challenging problems such as instabilities of the jet
in a strong magnetic field, induced eddy-current effects
on jet shape, thermal-shock formation, and possible jet
fragmentation. Problems associated with shock heating of
liquid jets in a strong magnetic field are analyzed in
this study.
Energy loss and effective charge of low-energy oxygen ions
in partially ionized plasma
Authors: NISHIGORI K. , NEUNER U. , TAKIZAWA M. , KOJIMA M. , SAGAMI T. , SAKUMI A. , HASEGAWA J. , OGURI Y. , OGAWA M.
Published: July 2002

This article reports on the interaction between slow
ions and a partially ionized plasma. Temporal evolutions
of energy loss and charge distribution of 2.4 MeV oxygen
beams in the laser-induced polyethylene plasma were measured.
The charge distribution showed strong stripping ability
in the early phase of the plasma. Stopping power deduced
from the experimental energy loss was 1.9 times larger
than that for the solid. The effective charge of the projectile
ion was estimated from the yields of 4+ and 6+ states.
The peak value of the effective charge was 1.4 times larger
than that of the solid. The stopping power equation given
by Sigmund was extended for the partially ionized plasma
and it could reproduce the measured energy loss.
Laser Larmor X-ray radiation from low-Z matter
Authors: UESHIMA YUTAKA , KISHIMOTO YASUAKI , SASAKI AKIRA , TAJIMA TOSHIKI
Published: July 2002

A relativistically intense short laser pulse can
produce a large flux of X rays through the interaction
with electrons that are driven by its intense electromagnetic
fields. Apart from X rays from the high-Z matter
irradiation by an intense laser, two main processes, Larmor
and Bremsstrahlung radiation, are among the most significant
mechanisms for X-ray emission from short-pulse laser irradiation
on low-Z matter in the regime of relativistic
intensities. We evaluate the power, energy spectrum, brilliance,
polarization, and time structure of these X rays. We suggest
a few methods that significantly enhance the power of Larmor
X rays. Because of the peakedness in the energy spectrum
of Larmor X rays, Larmor X rays have important applications.
J. Turunen and F. Wyrowski (eds.), Diffractive Optics
for Industrial and Commercial Applications, Akademie
Verlag, Berlin, Germany, 1997. 426 pp.
Authors: Jahns Juergen
Published: July 2002

The field of diffractive optics is at the same
time old and young. Diffraction gratings have been known
for two centuries and used extensively in spectroscopy,
for example. Also the theoretical understanding of the
basic properties of grating diffraction has been well developed
since that time. Until the 1960s, the technological foundation
of grating manufacture used to be precision mechanics.
It was then, when with the advent of the laser, things
gradually started to change. On the one hand, laser interferometry
became an additional tool to fabricate grating structures
with very small periods. On the other hand, many new applications
for optics started to develop based on the use of different
types of laser sources. Some examples that may be mentioned
are—besides modern spectroscopic techniques—areas
like material processing, optical communications and information
processing, optical data storage, etc. Consequently, the
term “diffractive optics” has obtained a different
flavor during the past 20–30 years. New types of
diffractive elements were being developed with new technologies.
This started in the mid-1960s with the invention of computer-generated
holography which allowed to create “arbitrary”
wavefronts (this means, within practical limits) by diffracting
a light wave at an irregular binary structure. The computation
and fabrication of computer-generated holograms was made
possible by then newly available digital computers and
plotting equipment. Since the early 1970s, people started
to make diffractive elements using microfabrication techniques
(lithography, etching, etc.) adapted from the processing
of electronic circuits. These ideas were initially demonstrated
in industrial research laboratories like Philips and Thomson-CSF.
New high-power laser facility PALS—prospects for laser–plasma
research
Authors: RUS B. , ROHLENA K. , SKÁLA J. , KRÁLIKOVÁ B. , JUNGWIRTH K. , ULLSCHMIED J. , WITTE K.J. , BAUMHACKER H.
Published: July 2002

In this paper, we report on a new laser facility
called PALS (Prague Asterix Laser System), which is currently
under construction, and which will house the high-power
iodine laser Asterix IV. Upon its completion in late 1999,
the PALS facility will be capable of providing single-
or multiple-pulse irradiation with a variable pulse duration
ranging from 100 to 500 ps. Wavelengths available will
be 1.315 μm, 658 nm, and 438 nm. The system will provide
one main beam with energy up to 1200 J and two smaller
auxiliary beams with a combined energy of up to 100 J.
A wide variety of geometries and variable pulse timings
is available. We assess PALS' potential for investigating
the physics of laser plasmas in inertial confinement fusion,
the development and applications of X-ray lasers, X-ray
spectroscopy, and radiation transport, using multiple-pulse
and extended beam capability.
Experimental study of line spectrum generation by argon
dopant in DT-gas on ISKRA-5 facility
Authors: BEL'KOV S.A. , BESSARAB A.V. , VESELOV A.V. , GAIDACH V.A. , DOLGOLEVA G.V. , ZHIDKOV N.V. , IZGORODIN V.M. , KIRILLOV G.A. , KOCHEMASOV G.G. , LITVIN D.N. , MKHITARIAN L.S. , MARTYNENKO S.P. , MITROPHANOV E.I. , MURUGOV V.M. , PETROV S.I. , PINEGIN A.V. , PUNIN V.T. , SUSLOV N.A.
Published: July 2002

The experiments measuring the density of DT mixture
compressed in indirect drive targets (X-ray targets) were
conducted on the ISKRA-5 facility. The density was determined
from the line broadening of H- and He-like Ar doped in
DT-gas as a diagnostic substance. A series of three experiments
with the X-ray targets having different shell thickness
of capsule filled with DT + Ar mixture were carried out.
In two of the three experiments, radiation spectra of Ar
were recorded and the density of compressed gas was determined.
The analysis of the experimental results for the X-ray
target with a 280-μm diameter and a 7 μm wall thickness
revealed that the density of the compressed gas may be
estimated as ∼1 g/cm3.
Study of the shell's large-scale asymmetry influence
on the target dynamics using the ISKRA-5 facility
Authors: BEL'KOV S.A. , BESSARAB A.V. , GAIDASH V.A. , ISGORODIN V.M. , KIRILLOV G.A. , KOCHEMASOV G.G. , KUNIN A.V. , LITVIN D.N. , MURUGOV V.M. , MKHITARIAN L.S. , PETROV S.I. , PINEGIN A.V. , PUNIN V.T. , SUSLOV N.A. , TOKAREV V.A. , VINOKUROV O.A. , ZHIDKOV N.V.
Published: July 2002

The first experiments to study the shell's
controlled asymmetry of capsule with DT-fuel in a highly
symmetrical X-ray field, which is obtained inside a spherical
hohlraum, were implemented. The asymmetry results from
the coating of one hemisphere with the additional layer
of material. The main goal of the experiment was to define
the value of the capsule asymmetry, allowing us to experimentally
obtain the neutron yield, which would be very different
from the yield obtained in the experiment with the spherically
symmetrical shell having the same mass as the asymmetrical
one. It was shown that the shell asymmetry of ∼50%
leads to the ∼(2–4) times reduction of the neutron
yield as compared with the symmetrical shell. 2D calculations
of the asymmetric capsule compression, using the MIMOZA-ND
code, were conducted. The calculations demonstrated that
the compression of targets, when exploding pusher regime
occurs has a complicated character. The computational neutron
yield, and the delay of the neutron generation time are
in good agreement with the experimental data.
Formation of a waveguide having the ultimately small cross-section
due to self-consistent propagation of a highly intensive
laser beam (1018 W/cm2) with duration
of 100 ps in an overdense plasma
Authors: KOCHEMASOV G.G. , MKHITARYAN L.S. , VOINOV B.A.
Published: July 2002

Here we study the problem of a focused laser beam
propagation in plasma with the initial density, which is
much higher than the critical one. The Helmholtz equations,
together with the equations of single fluid hydrodynamics,
with the relativistic ponderomotive force were solved.
It was shown that the stable waveguide with the cross-section
of wavelength size was formed when plasma was affected
by the laser radiation with the intensity exceeding the
critical one while the laser radiation pulse was as long
as (10–100) ps.
“State of Art” the program of target fabrication
at the Lebedev Physics Institute
Authors: KROKHIN O.N.
Published: July 2002

A novel approach for injection of a freestanding
target into an ICF chamber is described which could significantly
reduce both the dead volume of the target system and the
fill time of cryotarget. The extremely short flight time
of a target inside the ICF target chamber (less than 100
ms) allows one to keep the quality of the cryolayer up
to the very moment of target irradiation. The possibility
of improving the quality of the inner surface of the cryogenic
layer by using the target illumination by the electron
beams during the free fall of the target in the fusion
chamber is also discussed.
2D high power laser diode arrays for solid-state laser driver
inertial fusion energy project
Authors: BASOV N.G. , POPOV Yu.M. , BEZOTOSNY V.V. , KUMYKOV Kh.Kh.
Published: July 2002

2D arrays of laser diodes were developed and investigated
under QCW operating conditions. Output power and energy
density up to 1 kW/cm2 and 0.45 J/cm2
(at pulse duration 0.5 ms) were measured at the wavelength
810 nm. The spectral composition of radiation, shape of
the output pulses, and far-field and near-field radiation
zones were examined under various pumping parameters. The
kinetics of the temperature profiles in monolithic QCW
AlGaAs/GaAs linear bars and 2D arrays, emitting at the
wavelength 810 nm was modeled numerically. Quasi-CW and
CW operation under various pump parameters were considered
as a function of a heat sink design. A calculation model
was used to interpret the experimental dependences of the
output parameters of the arrays on the pump conditions
for application in the solid-state laser driver project.
The limit of total power conversion efficiency of diode
lasers was analyzed in respect of the threshold current
density, series resistance and external differential quantum
efficiency. The estimated maximum value of 75% was obtained
for the present technological level of the diode lasers
production. The corresponding limit of the output optical
power density of 2D laser array was defined around 10 kW/cm2.
Weibel instability by ultraintense laser pulses
Authors: OKADA T. , SAJIKI I. , SATOU K.
Published: July 2002

Particle-in-cell (PIC) simulations show that an
anisotropic electron velocity distribution is demonstrated
by ultraintense laser pulses in underdense plasmas. Recently,
it is reported that the anisotropy has been experimentally
demonstrated in laser-produced plasmas. It is also pointed
out that gigagauss magnetic fields are generated by ultraintense
laser pulses. We have already published that the Weibel-type
electromagnetic instabilities can be theoretically excited
by electrons in a velocity distribution with anisotropic
temperature. If these electromagnetic waves are excited,
the target may have a possibility not only to give rise
to a new type of energy loss mechanism but also to influence
the implosion characteristics. In this work, we present
PIC simulation of the interaction of ultraintense laser
pulses with plasmas. Intense self-generated magnetic fields
is produced by the mechanism of Weibel instability in underdense
plasmas.
Richtmyer–Meshkov instability evolution in layered system
Authors: ALESHIN A.N. , LAZAREVA E.V. , SERGEEV S.V. , ZAYTSEV S.G.
Published: July 2002

Presently, a great part of the attention paid to
the studies on the Richtmyer–Meshkov instability
(RMI) is focused on the case of shock passage through a
system of gas layers of different densities. The interest
to this problem has been induced, in particular, by multiple
attempts to minimize the process of mixing between the
layers of different densities in targets for inertial confinement
fusion (ICF), caused by excitation of the RMI on the layer
boundaries. The RMI suppression is one of the most important,
but difficult problems in worldwide efforts on ICF. A direct
investigation of this phenomenon in laser experiments (in
NOVA, for example) is a rather difficult task. Shock tubes
are a more promising tool for modeling the impulsively-driven
instabilities in gas layers, for they allow us a detailed
investigation of the mechanism of initiation and the pathways
of evolution of the instability (Jacobs et al.
1995; Aleshin et al. 1995a). A series of shock-tube
experiments for the shock passage through a system of gas
layers of different densities has been carried out. The
effect of a suppression of the RMI has been found. A 2.5-fold
reduction of the mixing region thickness in the presence
of the layer as compared to the thickness without it has
been obtained.
Development of holographic methods for investigating a moving
free surface, accelerated by laser-induced shock waves
Authors: WERDIGER M. , ELIEZER S. , MAMAN S. , HOROVITZ Y. , ARAD B. , HENIS Z. , GOLDBERG I.B.
Published: July 2002

Holographic methods developed to study the behavior
of surfaces shocked by high power lasers are reported.
Shock waves of the order of hundreds of kilobars are generated
in Sn targets 50-μm thick, by a Nd:YAG laser system
with a wavelength of 1.06 μm, a pulse duration of 7.5
ns FWHM, and irradiance in the range (1.0–2.6)·1013
W/cm2. Two configurations of off-axis holography
were applied: holograms based on forward scattering, and
holograms of both backward and forward scattering. The
hologram is produced by scattering of a pulse, 6.7 ns (FWHM),
of green laser light synchronized with the laser that generates
the shock wave. Holograms of the topology of the rear surface
of shocked Sn targets moving in vacuum and in air (at atmospheric
pressure) are reported.
Determination of singularity contours for five-bar planar parallel manipulators
Authors: Alıcı Gürsel
Published: July 2002

From a design point

of view, it is crucial to predict singular configurations of

a manipulator in terms of inputs in order to improve

the dexterity and workspace of a manipulator. In this paper,

we present a simple, yet a systematic appoach to obtain

singularity contours for a class of five-bar planar parallel manipulators

which are based on five rigid links and five single

degree of freedom joints – revolute and prismatic joints. The

determinants of the manipulator Jacobian matrices are evaluated in terms

of joint inputs for a specified set of geometric parameters,

and the contours of the determinants at 0.0 plane which

are the singularity contours in joint space are generated for

the three types of singularities reported in the literature. The

proposed approach/algorithm is simple and systematic, and the resulting equations

are easy to solve on a computer. The singularity contours

for all the class are presented in order to demonstrate

the method. It is concluded that the proposed method is

useful in trajectory planning and design of five-bar planar parallel

manipulators in order to improve their dexterity and workspace.
Stabilized minimum infinity-norm torque solution for redundant manipulators
Authors: Shim Ick-Chan , Yoon Yong-San
Published: July 2002

The minimization of the joint torques based on the ∞-norm is proposed for the dynamic control of a kinematically redundant manipulator. The ∞-norm is preferred to the 2-norm in the minimization of the joint torques since the maximum torques of the actuators are limited. To obtain the minimum ∞-norm torque solution, we devised a new algorithm that uses the acceleration polyhedron representing the end-effector's acceleration capability. Usually the minimization of the joint torques has an instability problem for the long trajectories of the end-effector. To suppress this instability problem, an inequality constraint, named the feasibility constraint, is developed from the geometrical relation between the required end-effector acceleration and the acceleration polyhedron. The minimization of the °-norm of the joint torques subject to the feasibility constraint is shown to improve the performances through the simulations of a 3-link planar redundant manipulator.
Kinematic modelling and trajectory planning for a tele-laparoscopic manipulating system
Authors: Faraz Ali , Payandeh Sharam
Published: July 2002

This paper addresses the kinematic modelling, solutions and trajectory planning of a tele-laparoscopic manipulator. This type of manipulator can be used in remote positioning of laparoscopic tools through tele-operating system. Specifically the paper models kinematics of a typical manipulating system which can be used in such tele-surgery. Inverse kinematics solutions are also obtained for two kinematically constraint motions which are part of a typical trajectory of the laparoscopic tools. These are fixed axis rotation of the tool and its

straight line motion. Simulation results are presented to demonstrate the validity of such models and solutions.
Developing strategies for delivering music technology in secondary PGCE courses
Authors: Busen-Smith Maria
Published: July 2002

For some years, music technology has been incorporated into the secondary music Post-Graduate Certificate in Education (PGCE) course at Kingston University. Student evaluations of this work have been supportive in the main, but identified continuing challenges in relation to establishing a sense of ease with its application in education. A range of course developments were devised in response, and closely monitored in 1997. The first half of this article outlines the rationale behind them. It draws upon a range of texts that document the reception of IT in schools and colleges, and on an interpretative response (based on theories of cognition), which the writer feels holds much relevance for music educators. The second half outlines course developments, and includes feedback from students and partner schools. Eighteen months on, the fundamental strategy is still in place, and staff have found it consistent with the requirements for ICT outlined in circular 4/98 by the DfEE.
HEALTH TECHNOLOGY ASSESSMENT IN BELGIUM
Authors: Cleemput Irina , Kesteloot Katrien
Published: July 2002

The Belgian healthcare system has a Bismarck-type compulsory health insurance,

covering almost the entire population, combined with private provision of care. Providers are

public health services, independent pharmacists, independent ambulatory care professionals,

and hospitals and geriatric care facilities. Healthcare responsibilities are shared between

the national Ministries of Public Health and Social Affairs, and the Dutch-, French-, and German-speaking

Community Ministries of Health. The national ministries are responsible for sickness and disability

insurance, financing, determination of accreditation criteria for hospitals and heavy medical care units,

and

construction of new hospitals. The six sickness and disability insurance funds

are responsible for reimbursing health service benefits

and paying disability benefits. The

system's strength is that care is highly accessible and responsive to patients.

However, the healthcare system's size remained relatively

uncontrolled until recently, there is an excess supply of certain types of care, and there is a large number of

small hospitals. The national government created a legal framework to modernize the

insurance system to control budgetary deficits. Measures for reducing

healthcare expenditures include regulating healthcare supply, healthcare evaluation, medical

practice organization, and hospital budgets. The need to control healthcare facilities and quality of

care in hospitals led to formal procedures for opening hospitals,

acquiring expensive medical equipment, and developing highly specialized services. Reforms in

payment and regulation are being considered. Health technology assessment (HTA) has played little part

in the reforms so far. Belgium has no formal national program for HTA. The future

of HTA in Belgium depends on a changing perception by providers and policy makers that health care

needs a stronger scientific base.
Impacts of density and large mammals on space use by the pouched mouse (Saccostomus mearnsi) in central Kenya
Authors: KEESING FELICIA , CRAWFORD TARA
Published: July 2002

Rodents in tropical Africa have been recognized for decades both as important pests of agriculture and as reservoirs
of numerous diseases that affect humans and livestock (Keesing 2000). Despite this recognition, however, little is
known about the ecology and behaviour of these abundant and widespread animals. Because the impacts of small
mammals as pests are expected to be some function of their population density, most ecological research on African
rodents has focused on their population dynamics (Delany 1972, 1986; Leirs et al. 1994, 1996a).