193 research outputs found
An overview on armor research for the laser fusion project HiPER
During the current preparatory phase of the European laser fusion project HiPER, an intensive effort has being placed to identify an armour material able to protect the internal walls of the chamber against the high thermal loads and high fluxes of x-rays and ions produced during the fusion explosions. This poster addresses the different threats and limitations of a poly-crystalline Tungsten armour. The analysis is carried out under the conditions of an experimental chamber hypothetically constructed to demonstrate laser fusion in a repetitive mode, subjected to a few thousand 48MJ shock ignition shots during its entire lifetime. If compared to the literature, an extrapolation of the thermomechanical and atomistic effects obtained from the simulations of the experimental chamber to the conditions of a Demo reactor (working 24/7 at hundreds of MW) or a future power plant (producing GW) suggests that “standard” tungsten will not be a suitable armour. Thus, new materials based on nano-structured W and C are being investigated as possible candidates. The research programme launched by the HiPER material team is introduced
High-Resolution Observations in B1-IRS: ammonia, CCS and water masers
We present a study of the structure and dynamics of the star forming region
B1-IRS (IRAS 03301+3057) using the properties of different molecules at high
angular resolution (~4''). We have used VLA observations of NH3, CCS, and H2O
masers at 1 cm. CCS emission shows three clumps around the central source, with
a velocity gradient from red to blueshifted velocities towards the protostar,
probably due to the interaction with outflowing material. Water maser emission
is elongated in the same direction as a reflection nebula detected at 2micron
by 2MASS, with the maser spots located in a structure of some hundreds of AU
from the central source, possibly tracing a jet. We propose a new outflow model
to explain all our observations, consisting of a molecular outflow near the
plane of the sky. Ammonia emission is extended and anticorrelated with CCS. We
have detected for the first time this anticorrelation at small scales (1400 AU)
in a star forming region.Comment: 6 pages, 3 figures. To appear in the Proceedings of the 2004 European
Workshop: "Dense Molecular Gas around Protostars and in Galactic Nuclei",
Eds. Y.Hagiwara, W.A.Baan, H.J.van Langevelde, 2004, a special issue of ApSS,
Kluwe
Temperature Evolution and Light Species Diffusion in Armor and Structural Material for Inertial Fusion Reactor Chambers: a Case for HiPER 4a
One of the most advance designs for HiPER fusion reactor is a spherical chamber 10 m in diameter based on dry wall concept. In this system, the first wall will have to withstand short energy pulses of 5 to 20 MJ at a repetition rate of 0.5-10 Hz mostly in form of X-rays and charged particles. To avoid melting of the inner surface, the first wall consists on a thin armor attached to the structural material. Thickness (th) and material of each layer have to be chosen to assure the proper functioning of the facility during its planned lifetime
Improving emergency plans management with SAGA
[EN] Emergency plans are the tangible result of the preparedness activities of the emergency management lifecycle. In many countries, public service organizations have the legal obligation to develop and maintain emergency plans covering all possible hazards relative to their areas of operation. However, little support is provided to planners in the development and use of plans. Often, advances in software technology have not been exploited, and plans remain as text documents whose accessibility is very limited. In this paper, we advocate for the definition and implementation of plan management processes as the first step to better produce and manage emergency plans. The main contribution of our work is to raise the need for IT-enabled planning environments, either at the national or organization-specific levels, which can lead to more uniform plans that are easier to evaluate and share, with support to stakeholders other than responders, among other advantages. To illustrate our proposal, we introduce SAGA, a framework that supports the full lifecycle of emergency plan management. SAGA provides all the actors involved in plan management with a number of tools to support all the stages of the plan lifecycle. We outline the architecture of the system, and show with a case study how planning processes can benefit from a system like SAGA.We thank J. Marzal and R. Garrido, from the UPV Prevention Service, for their cooperation in the early design of SAGA. The work of J.H. Canós, M.C. Penadés, M. Llavador and A. Gómez is partially funded by the Spanish Ministerio de Educación y Ciencia (MEC) under grant TIPEx (TIN2010-19859-C03-03). The work of M.R.S. Borges is partially supported by grant nos. 560223/2010-2 and 308003/2011-0 from CNPq (Brazil) and
grant no. E-26/103.076/2011 from FAPERJ (Brazil). The cooperation between the Brazilian and the Spanish research groups was partially sponsored by the CAPES/MECD Cooperation Program, Project #169/PHB2007-0064-PC.Canos Cerda, JH.; Borges, M.; Penadés Gramage, MC.; Gómez Llana, A.; Llavador Campos, M. (2013). Improving emergency plans management with SAGA. Technological Forecasting and Social Change. 80(9):1868-1876. https://doi.org/10.1016/j.techfore.2013.02.014S1868187680
A framework for variable content document generation with multiple actors
“NOTICE: this is the author’s version of a work that was accepted for publication in Information and Software Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Information and Software Technology, Volume 56, Issue 9, September 2014, Pages 1101–1121 DOI10.1016/j.infsof.2013.12.006Context -
Advances in customization have highlighted the need for tools supporting variable content document management and generation in many domains. Current tools allow the generation of highly customized documents that are variable in both content and layout. However, most frameworks are technology-oriented, and their use requires advanced skills in implementation-related tools, which means their use by end users (i.e. document designers) is severely limited.
Objective -
Starting from past and current trends for customized document authoring, our goal is to provide a document generation alternative in which variants are specified at a high level of abstraction and content reuse can be maximized in high variability scenarios.
Method
Based on our experience in Document Engineering, we identified areas in the variable content document management and generation field open to further improvement. We first classified the primary sources of variability in document composition processes and then developed a methodology, which we called DPL based on Software Product Lines principles to support document generation in high variability scenarios.
Results -
In order to validate the applicability of our methodology we implemented a tool DPLfw to carry out DPL processes. After using this in different scenarios, we compared our proposal with other state-of-the-art tools for variable content document management and generation.
Conclusion -
The DPLfw showed a good capacity for the automatic generation of variable content documents equal to or in some cases surpassing other currently available approaches. To the best of our knowledge, DPLfw is the only framework that combines variable content and document workflow facilities, easing the generation of variable content documents in which multiple actors play different roles.This work has been partially funded by the Spanish Ministerio de Economia y Competitividad under Grant TIPEx (TIN2010-19859-C03-03).Gómez Llana, A.; Penadés Gramage, MC.; Canos Cerda, JH.; Borges, MR.; Llavador Campos, M. (2014). A framework for variable content document generation with multiple actors. Information and Software Technology. 56(9):1101-1121. https://doi.org/10.1016/j.infsof.2013.12.006S1101112156
Chiral unitary approach to S-wave meson baryon scattering in the strangeness S=0 sector
We study the S-wave interaction of mesons with baryons in the strangeness S=0
sector in a coupled channel unitary approach. The basic dynamics is drawn from
the lowest order meson baryon chiral Lagrangians. Small modifications inspired
by models with explicit vector meson exchange in the t-channel are also
considered. In addition the pi pi N channel is included and shown to have an
important repercussion in the results, particularly in the isospin 3/2 sector.Comment: 23 pages, LaTeX, 21 figure
Adaptive Mesh Refinement for Characteristic Grids
I consider techniques for Berger-Oliger adaptive mesh refinement (AMR) when
numerically solving partial differential equations with wave-like solutions,
using characteristic (double-null) grids. Such AMR algorithms are naturally
recursive, and the best-known past Berger-Oliger characteristic AMR algorithm,
that of Pretorius & Lehner (J. Comp. Phys. 198 (2004), 10), recurses on
individual "diamond" characteristic grid cells. This leads to the use of
fine-grained memory management, with individual grid cells kept in
2-dimensional linked lists at each refinement level. This complicates the
implementation and adds overhead in both space and time.
Here I describe a Berger-Oliger characteristic AMR algorithm which instead
recurses on null \emph{slices}. This algorithm is very similar to the usual
Cauchy Berger-Oliger algorithm, and uses relatively coarse-grained memory
management, allowing entire null slices to be stored in contiguous arrays in
memory. The algorithm is very efficient in both space and time.
I describe discretizations yielding both 2nd and 4th order global accuracy.
My code implementing the algorithm described here is included in the electronic
supplementary materials accompanying this paper, and is freely available to
other researchers under the terms of the GNU general public license.Comment: 37 pages, 15 figures (40 eps figure files, 8 of them color; all are
viewable ok in black-and-white), 1 mpeg movie, uses Springer-Verlag svjour3
document class, includes C++ source code. Changes from v1: revised in
response to referee comments: many references added, new figure added to
better explain the algorithm, other small changes, C++ code updated to latest
versio
Two-body decays in the minimal 331 model
The two-body decays of the extra neutral boson Z_2 predicted by the minimal
331 model are analyzed. At the three-level it can decay into standard model
particles as well as exotic quarks and the new gauge bosons predicted by the
model. The decays into a lepton pair are strongly suppressed, with and . In the bosonic
sector, Z_2 would decay mainly into a pair of bilepton gauge bosons, with a
branching ratio below the 0.1 level. The Z_2 boson has thus a leptophobic and
bileptophobic nature and it would decay dominantly into quark pairs. The
anomaly-induced decays and , which occurs
at the one-loop level are studied. It is found that and at most. As for the and decays, with H a relatively light Higgs boson, they
are induced via Z'-Z mixing. It is obtained that
and . We also examine the flavor changing neutral
current decays and , which may have branching
fractions as large as and , respectively, and thus may be of
phenomenological interest.Comment: 14 pages, 3 figures, submitted to Physical Review
Exploring metabolic responses of potato tissue induced by electric pulses
In this study, we investigated the metabolic
responses of potato tissue induced by pulsed electric field
(PEF). Potato tissue was subjected to field strengths ranging
from 30 to 500 V/cm, with a single rectangular pulse of 10 μs,
100 μs, or 1 ms. Metabolic responses were monitored using
isothermal calorimetry, changes on electrical resistance during
the delivery of the pulse, as well as impedance measurements.
Our results show that the metabolic response involves oxygen
consuming pathways as well as other unidentified events that
are shown to be insensitive to metabolic inhibitors such as
KCN and sodium azide. The metabolic response is strongly
dependent on pulsing conditions and is independent of the
total permeabilization achieved by the pulse. Evidence shows
that calorimetry is a simple and powerful method for
exploring conditions for metabolic stimulation, providing
information on metabolic responses that can not be obtained
from electrical measurements. This study set the basis for
further investigations on defense-related consequences of
PEF-induced stress.Sparbanksstiftelsen Färs & Frosta (Sweden).Fundação para a Ciência e a Tecnologia (FCT).Lund University (Sweden).Department of Cell and Organism Biology; Department of Plant Biochemistry
Diffusion Issues of Heat and Light Species in Laser Fusion Devices
There are several heat and mass diffusion problems which affect to the IFC chamber design. New simulation models and experiments are needed to take into account the extreme conditions due to ignition pulses and neutron flu
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