4,854 research outputs found
Behavior of self-propelled acetone droplets in a Leidenfrost state on liquid substrates
It is demonstrated that non-coalescent droplets of acetone can be formed on
liquid substrates. The fluid flows around and in an acetone droplet hovering on
water are recorded to shed light on the mechanisms which might lead to
non-coalescence. For sufficiently low impact velocities, droplets undergo a
damped oscillation on the surface of the liquid substrate but at higher
velocities clean bounce-off occurs. Comparisons of experimentally observed
static configurations of floating droplets to predictions from a theoretical
model for a small non-wetting rigid sphere resting on a liquid substrate are
made and a tentative strategy for determining the thickness of the vapor layer
under a small droplet on a liquid is proposed. This strategy is based on the
notion of effective surface tension. The droplets show self-propulsion in
straight line trajectories in a manner which can be ascribed to a Marangoni
effect. Surprisingly, self-propelled droplets can become immersed beneath the
undisturbed water surface. This phenomenon is reasoned to be drag-inducing and
might provide a basis for refining observations in previous work
Enhanced transmission versus localization of a light pulse by a subwavelength metal slit: Can the pulse have both characteristics?
The existence of resonant enhanced transmission and collimation of light
waves by subwavelength slits in metal films [for example, see T.W. Ebbesen et
al., Nature (London) 391, 667 (1998) and H.J. Lezec et al., Science, 297, 820
(2002)] leads to the basic question: Can a light be enhanced and simultaneously
localized in space and time by a subwavelength slit? To address this question,
the spatial distribution of the energy flux of an ultrashort (femtosecond)
wave-packet diffracted by a subwavelength (nanometer-size) slit was analyzed by
using the conventional approach based on the Neerhoff and Mur solution of
Maxwell's equations. The results show that a light can be enhanced by orders of
magnitude and simultaneously localized in the near-field diffraction zone at
the nm- and fs-scales. Possible applications in nanophotonics are discussed.Comment: 5 figure
Secondary pulmonary alveolar proteinosis treated by lung transplant: A case report.
Pulmonary alveolar proteinosis (PAP) is a pulmonary disease characterized by disruption of surfactant homeostasis resulting in its accumulation in the alveoli. PAP is classically classified into three categories (Table 1): 1/primary (or autoimmune) with antibodies targeting the GM-CSF pathway, 2/secondary to another disease, typically a hematologic malignancy, and 3/genetic.
A 30 year-old woman received an allogenic hematopoietic stem cell transplantation (HSCT) after treatment for acute myeloid leukemia (AML). Within the first 6 months post HSCT, she developed an ocular, oral, digestive and hepatic graft-versus-host disease associated with a mixed ventilatory defect with a very severe obstructive syndrome and a severe CO diffusion impairment. High resolution computed tomography showed a classical "crazy paving" pattern. Aspect and differential cell count of BAL were normal. All microbiological samples remained culture negative. Histo-pathological analysis of transbronchial biopsies was unremarkable. Because of the severity of the respiratory insufficiency, open-lung biopsy (OBL) could not be performed. Despite multiple immunosuppressive therapies, lung function deteriorated rapidly; the patient also developed an excavated fungal lesion unresponsive to treatment. She underwent a bilateral lung transplant 48 months after HSCT. Histo-pathological analysis of explanted lungs showed obliterative bronchiolitis (OB), diffuse PAP and invasive cavitary pulmonary aspergillosis.
This case illustrates the simultaneous occurrence of OB, PAP and a fungal infection in a 30-year old female patient who underwent HSCT for acute myeloid leukemia (AML). To our knowledge this is the only documented case of PAP associated with OB treated by lung transplantation
Nuclear Theory and Science of the Facility for Rare Isotope Beams
The Facility for Rare Isotope Beams (FRIB) will be a world-leading laboratory
for the study of nuclear structure, reactions and astrophysics. Experiments
with intense beams of rare isotopes produced at FRIB will guide us toward a
comprehensive description of nuclei, elucidate the origin of the elements in
the cosmos, help provide an understanding of matter in neutron stars, and
establish the scientific foundation for innovative applications of nuclear
science to society. FRIB will be essential for gaining access to key regions of
the nuclear chart, where the measured nuclear properties will challenge
established concepts, and highlight shortcomings and needed modifications to
current theory. Conversely, nuclear theory will play a critical role in
providing the intellectual framework for the science at FRIB, and will provide
invaluable guidance to FRIB's experimental programs. This article overviews the
broad scope of the FRIB theory effort, which reaches beyond the traditional
fields of nuclear structure and reactions, and nuclear astrophysics, to explore
exciting interdisciplinary boundaries with other areas.
\keywords{Nuclear Structure and Reactions. Nuclear
Astrophysics. Fundamental Interactions. High Performance
Computing. Rare Isotopes. Radioactive Beams.Comment: 20 pages, 7 figure
Lifetime measurements of Triaxial Strongly Deformed bands in Tm
With the Doppler Shift Attenuation Method, quadrupole transition moments,
, were determined for the two recently proposed Triaxial Strongly Deformed
(TSD) bands in Tm. The measured moments indicate that the
deformation of these bands is larger than that of the yrast, signature
partners. However, the measured values are smaller than those predicted by
theory. This observation appears to be valid for TSD bands in several nuclei of
the regionComment: 8 pages, 5 figures. Submitted to Physical Review
In-beam spectroscopy of medium- and high-spin states in Ce
Medium and high-spin states in Ce were investigated using the
Cd(Ne, ) reaction and the Gammasphere array. The level
scheme was extended up to an excitation energy of MeV and spin 93/2
. Eleven bands of quadrupole transitions and two new dipole bands are
identified. The connections to low-lying states of the previously known,
high-spin triaxial bands were firmly established, thus fixing the excitation
energy and, in many cases, the spin parity of the levels. Based on comparisons
with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant
density functional theory, it is shown that all observed bands are
characterized by pronounced triaxiality. Competing multiquasiparticle
configurations are found to contribute to a rich variety of collective
phenomena in this nucleus.Comment: 20 pages, 11 figure
Acceptability with general orderings
We present a new approach to termination analysis of logic programs. The
essence of the approach is that we make use of general orderings (instead of
level mappings), like it is done in transformational approaches to logic
program termination analysis, but we apply these orderings directly to the
logic program and not to the term-rewrite system obtained through some
transformation. We define some variants of acceptability, based on general
orderings, and show how they are equivalent to LD-termination. We develop a
demand driven, constraint-based approach to verify these
acceptability-variants.
The advantage of the approach over standard acceptability is that in some
cases, where complex level mappings are needed, fairly simple orderings may be
easily generated. The advantage over transformational approaches is that it
avoids the transformation step all together.
{\bf Keywords:} termination analysis, acceptability, orderings.Comment: To appear in "Computational Logic: From Logic Programming into the
Future
Spectroscopy of the odd-odd fp-shell nucleus 52Sc from secondary fragmentation
The odd-odd fp-shell nucleus 52Sc was investigated using in-beam gamma-ray
spectroscopy following secondary fragmentation of a 55V and 57Cr cocktail beam.
Aside from the known gamma-ray transition at 674(5)keV, a new decay at
E_gamma=212(3) keV was observed. It is attributed to the depopulation of a
low-lying excited level. This new state is discussed in the framework of
shell-model calculations with the GXPF1, GXPF1A, and KB3G effective
interactions. These calculations are found to be fairly robust for the
low-lying level scheme of 52Sc irrespective of the choice of the effective
interaction. In addition, the frequency of spin values predicted by the shell
model is successfully modeled by a spin distribution formulated in a
statistical approach with an empirical, energy-independent spin-cutoff
parameter.Comment: accepted for publication in PR
UvA-DARE (Digital Academic Repository) Multicentre European study of thalamic stimulation in parkinsonian and essential tremor
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