4,457 research outputs found
Ocorrencia da cigarrinha Molomea cincta (Signoret, 1854) em mangueira, na microrregiao de Teresina-PI.
bitstream/item/83446/1/CT940001.pd
Situation based strategic positioning for coordinating a team of homogeneous agents
. In this paper we are proposing an approach for coordinating a team ofhomogeneous agents based on a flexible common Team Strategy as well as onthe concepts of Situation Based Strategic Positioning and Dynamic Positioningand Role Exchange. We also introduce an Agent Architecture including a specifichigh-level decision module capable of implementing this strategy. Ourproposal is based on the formalization of what is a team strategy for competingwith an opponent team having opposite goals. A team strategy is composed of aset of agent types and a set of tactics, which are also composed of several formations.Formations are used for different situations and assign each agent a defaultspatial positioning and an agent type (defining its behaviour at several levels).Agents reactivity is also introduced for appropriate response to the dynamicsof the current situation. However, in our approach this is done in a way thatpreserves team coherence instead of permitting uncoordinated agent behaviour.We have applied, with success, this coordination approach to the RoboSoccersimulated domain. The FC Portugal team, developed using this approach wonthe RoboCup2000 (simulation league) European and World championshipsscoring a total of 180 goals and conceding none
Simulation of VUV electroluminescence in micropattern gaseous detectors: the case of GEM and MHSP
Electroluminescence produced during avalanche development in gaseous
avalanche detectors is an useful information for triggering, calorimetry and
tracking in gaseous detectors. Noble gases present high electroluminescence
yields, emitting mainly in the VUV region. The photons can provide signal
readout if appropriate photosensors are used. Micropattern gaseous detectors
are good candidates for signal amplification in high background and/or low rate
experiments due to their high electroluminescence yields and radiopurity. In
this work, the VUV light responses of the Gas Electron Multiplier and of the
Micro-Hole Strip Plate, working with pure xenon, are simulated and studied in
detail using a new and versatile C++ toolkit. It is shown that the solid angle
subtended by a photosensor placed below the microstructures depends on the
operating conditions. The obtained absolute EL yields, determined for different
gas pressures and as functions of the applied voltage, are compared with those
determined experimentally.Comment: Accepted for publication in Journal of Instrumentatio
Contribution to a macromycete survey of the states of Rio Grande do Sul and Santa Catarina in Brazil
Line shape analysis of the K transition in muonic hydrogen
The K transition in muonic hydrogen was measured with a
high-resolution crystal spectrometer. The spectrum is shown to be sensitive to
the ground-state hyperfine splitting, the corresponding triplet-to-singlet
ratio, and the kinetic energy distribution in the state. The hyperfine
splitting and triplet-to-singlet ratio are found to be consistent with the
values expected from theoretical and experimental investigations and,
therefore, were fixed accordingly in order to reduce the uncertainties in the
further reconstruction of the kinetic energy distribution. The presence of
high-energetic components was established and quantified in both a
phenomenological, i.e. cascade-model-free fit, and in a direct deconvolution of
the Doppler broadening based on the Bayesian approach.Comment: 22 pages, 21 figure
ANALYSIS OF AN EXTREME LOSS OF COOLANT IN THE IPR-R1 TRIGA REACTOR USING A RELAP5 MODEL
The RELAP5/MOD3.3 code has been applied for thermal hydraulic analysis of power reactors as well as nuclear research reactors with good predictions. The development and the assessment of a RELAP5 model for the IPR-R1 TRIGA have been validated for steady state and transient situations. The reactor is located at the Nuclear Technology Development Centre (CDTN), Brazil. It is a 250 kW, light water moderated and cooled, graphite-reflected, open pool type research reactor. In this work, an extreme transient case of loss of coolant accident (LOCA) has been simulated. For this type of analysis, the automatic scram of the reactor was not considered because the main aim was to verify the evolution of the fuel elements heating in the absence of coolant. The temperature evolutions are presented as well as an analysis about the temperature safety limits
Portal Vein Embolization With N-Butyl-Cyanoacrylate Through an Ipsilateral Approach Before Major Hepatectomy: Single Center Analysis of 50 Consecutive Patients
PURPOSE:
To evaluate the efficacy of portal vein embolization (PVE) with n-Butyl-cyanoacrylate (NBCA) through an ipsilateral approach before major hepatectomy. Secondary end-points were PVE safety, liver resection and patient outcome.
METHODS:
Over a 5-year period 50 non-cirrhotic consecutive patients were included with primary or secondary liver cancer treatable by hepatectomy with a liver remnant (FLR) volume less than 25% or less than 40% in diseased livers.
RESULTS:
There were 37 men and 13 women with a mean age of 57 years. Colorectal liver metastases were the most frequent tumor and patients were previously exposed to chemotherapy. FLR increased from 422 ml to 629 ml (P < 0.001) after PVE, corresponding to anincrease of 52%. The FLR ratio increased from 29.6% to 42.3% (P < 0.001). Kinetic growth rate was 2.98%/week. A negative association was observed between increase in the FLR and FLR ratio and FLR volume before PVE (P = 0.002). In 31 patients hepatectomy was accomplished and only one patient presented with liver insufficiency within 30 days after surgery.
CONCLUSIONS:
PVE with NBCA through an ipsilateral puncture is effective before major hepatectomy. Meticulous attention is needed especially near the end of the embolization procedure to avoid complications.info:eu-repo/semantics/publishedVersio
Pionic Deuterium
The strong interaction shift and broadening in pionic deuterium have been
remeasured with high statistics by means of the (3p-1s) X-ray transition using
the cyclotron trap and a high-resolution crystal spectrometer. Preliminary
results are (-2325+/-31) meV (repulsive) for the shift and (1171+23/-49} meV
for the width, which yields precise values for the pion-deuteron scattering
length and the threshold parameter for pion production.Comment: Conf. Proc. Few Body 19 (FB19), August 31 - September 5, 2009, Bonn,
Germany 9 pages, 13 figure
Line shape of the muH(3p - 1s) hyperfine transitions
The (3p - 1s) X-ray transition to the muonic hydrogen ground state was
measured with a high resolution crystal spectrometer. A Doppler effect
broadening of the X-ray line was established which could be attributed to
different Coulomb de-excitation steps preceding the measured transition. The
assumption of a statistical population of the hyperfine levels of the muonic
hydrogen ground state was directly confirmed by the experiment and measured
values for the hyperfine splitting can be reported. The results allow a
decisive test of advanced cascade model calculations and establish a method to
extract fundamental strong-interaction parameters from pionic hydrogen
experiments.Comment: Submitted to Physical Review Letter
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