754 research outputs found
Dynamic Response and Optimal Design of Curved Metallic Sandwich Panels under Blast Loading
It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a âsoftâ outer face and a âhardâ inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances
Association of metabolic syndrome with erosive esophagitis and Barrettâs esophagus in a Chinese population
AbstractBackgroundMetabolic syndrome has been highlighted as a risk factor for several gastrointestinal diseases, including gastroesophageal reflux disease and Barrettâs esophagus (BE). The aim of this study was to investigate the association of metabolic syndrome with erosive esophagitis (EE) and BE.MethodsData were retrospectively collected from patients who visited the Medical Screening Center at Taichung Veterans General Hospital, Taichung, Taiwan from January 2006 to December 2009. All patients underwent an open-access transoral upper gastrointestinal endoscopy, and serum laboratory data were collected. The exclusion criteria included prior gastric surgery, or presence of esophageal varices or peptic ulcers. These patients were assigned to groups according to their endoscopic findings as follows: (1) normal group; (2) EE group; and (3) BE group. Metabolic syndrome was diagnosed based on the International Diabetes Federation criteria.ResultsThere were 560/6499 (8.6%) patients, 214/1118 (9.6%) patients, and 19/95 (20%) patients with metabolic syndrome in the normal, EE, and BE groups, respectively. There was a significantly higher percentage of cases with hypertriglyceridemia in the EE group (67%) compared with the other groups. The BE group had significantly higher rates of central obesity (33%) and hypertension (29.5%) compared with rates in the normal and EE groups. After adjusting for confounders, the positive association with metabolic syndrome still existed in both the EE group (adjusted odds ratio=2.43; 95% confidence interval=1.02â3.44) and the BE group (adjusted odds ratio=2.82; 95% confidence interval=2.05â3.88).ConclusionOur research indicated that in fact there is a greater risk of concurrent metabolic syndrome in patients with EE or BE
Consecutive Tumor Lysis Syndrome and Hepatic Failure after Transarterial Chemoembolization for Treatment of Hepatocellular Aarcinoma: A Case Report and Literature Review
Introduction: Acute tumor lysis syndrome (ATLS) and hepatic failure are fatal complications that can occur in patients with hepatocellular carcinoma (HCC) who undergo transarterial chemoembolization (TACE).Presentation of Case: We report the case of a 78-year-old man with HCC who had successive ATLS and hepatic failure after the first course of TACE. He succumbed due to rapid deterioration of his condition.Conclusion: We therefore concluded that awareness of the risks of ATLS and hepatic failure before administration of TACE is crucial in patients with HCC
Identifying water stress-response mechanisms in citrus by in silico transcriptome analysis
f0(980) production in inelastic pp collisions at s = 5.02 TeV
The measurement of the production of f0(980) in inelastic pp collisions at sqrt(s) = 5.02 TeV is presented. This is the first reported measurement of inclusive f0(980) yield at LHC energies. The production is measured at midrapidity, |y| pi+pi- hadronic decay channel using the ALICE detector. The pT-differential yields are compared to those of pions, protons and Ï mesons as well as to predictions from the HERWIG 7.2 QCD-inspired Monte Carlo event generator and calculations from a coalescence model that uses the AMPT model as an input. The ratio of the pT-integrated yield of f0(980) relative to pions is compared to measurements in e+e- and pp collisions at lower energies and predictions from statistical hadronisation models and HERWIG 7.2. A mild collision energy dependence of the f0(980) to pion production is observed in pp collisions from SPS to LHC energies. All considered models underpredict the pT-integrated 2f0(980)/(pi+ + pi-) ratio. The prediction from the canonical statistical hadronisation model assuming a zero total strangeness content of f0(980) is consistent with the data within 1.9Ï and is the closest to the data. The results provide an essential reference for future measurements of the particle yield and nuclear modification in pâPb and PbâPb collisions, which have been proposed to be instrumental to probe the elusive nature and quark composition of the f0(980) scalar meson
Light (anti)nuclei production in Pb-Pb collisions at sNN=5.02Â TeV
The measurement of the production of deuterons, tritons and 3 He and their antiparticles in Pb-Pb collisions
at âs NN = 5.02 TeV is presented in this article. The measurements are carried out at midrapidity (|y| <
0.5) as a function of collision centrality using the ALICE detector. The pT -integrated yields, the coalescence
parameters and the ratios to protons and antiprotons are reported and compared with nucleosynthesis models. The
comparison of these results in different collision systems at different center-of-mass collision energies reveals a
suppression of nucleus production in small systems. In the Statistical Hadronisation Model framework, this can
be explained by a small correlation volume where the baryon number is conserved, as already shown in previous
fluctuation analyses. However, a different size of the correlation volume is required to describe the proton yields
in the same data sets. The coalescence model can describe this suppression by the fact that the wave functions
of the nuclei are large and the fireball size starts to become comparable and even much smaller than the actual
nucleus at low multiplicities
Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p-Pb collisions
Measurements of the production of electrons from heavy-flavour hadron decays in pp collisions at root s = 13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (p(T)) of 0.2 GeV/c and up to p(T) = 35 GeV/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p-Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the p(T) range 0.5 < p(T) < 26 GeV/c at root s(NN) = 8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p-Pb collisions grow faster than linear with the self-normalised multiplicity. A strong p(T) dependence is observed in pp collisions, where the yield of high-p(T) electrons increases faster as a function of multiplicity than the one of low-p(T) electrons. The measurement in p-Pb collisions shows no p(T) dependence within uncertainties. The self-normalised yields in pp and p-Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations
Production of pions, kaons, and protons as a function of the relative transverse activity classifier in pp collisions at = 13 TeV
Abstract: The production of ϱ, K±, and ( p )p is measured in pp collisions at âs = 13 TeV
in different topological regions of the events. Particle transverse momentum (pT) spectra are
measured in the âtowardâ, âtransverseâ, and âawayâ angular regions defined with respect
to the direction of the leading particle in the event. While the toward and away regions
contain the fragmentation products of the near-side and away-side jets, respectively, the
transverse region is dominated by particles from the Underlying Event (UE). The relative
transverse activity classifier, RT = NT/ăNTă, is used to group events according to their UE
activity, where NT is the measured charged-particle multiplicity per event in the transverse
region and ăNTă is the mean value over all the analysed events. The first measurements
of identified particle pT spectra as a function of RT in the three topological regions are
reported. It is found that the yield of high transverse momentum particles relative to the
RT-integrated measurement decreases with increasing RT in both the toward and the away
regions, indicating that the softer UE dominates particle production as RT increases and
validating that RT can be used to control the magnitude of the UE. Conversely, the spectral
shapes in the transverse region harden significantly with increasing RT. This hardening
follows a mass ordering, being more significant for heavier particles. Finally, it is observed
that the pT-differential particle ratios (p + p )/(Ï+ + Ïâ) and (K+ + Kâ)/(Ï+ + Ïâ) in
the low UE limit (RT â 0) approach expectations from Monte Carlo generators such as
PYTHIA 8 with Monash 2013 tune and EPOS LHC, where the jet-fragmentation models
have been tuned to reproduce e+eâ results
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