562 research outputs found
Performance Evaluation of a Temperature Control Stage Used on a Semiconductor Gas Sensor 3D Electro-Thermal Model Through Simulink(r)
Sulfate attack and reinforcement corrosion in concrete with recycled concrete aggregates and supplementary cementing materials
As strategies to contribute to the concrete industry sustainability, reinforced concrete was fabricated using recycled concrete coarse aggregate and replacing partially portland cement with supplementary cementing materials as fly ash and silica fume. On test specimens, partially immersed in 3.5% Na2SO4 aqueous solution, the effect of the recycled and supplementary materials against sulfate attack and reinforcement corrosion was evaluated. For such aim, weight loss of concrete and corrosion potentials, corrosion current density of reinforcement were determined by means of electrochemical techniques as open circuit potential and linear polarization resistance, respectivelyPostprint (published version
Chloride ion penetrability and corrosion behavior of steel in concrete with sustainability characteristics
Postprint (published version
The Mexican consensus on the diagnosis, treatment, and prevention of NSAID-induced gastropathy and enteropathy
MĂĄs de 30 millones de personas consumen diariamente antiinflamatorios noesteroideos (AINE) en el mundo, y este consumo se ve incrementado anualmente. Aunque losAINE poseen propiedades analgĂŠsicas y antiinflamatorias, sus eventos adversos gastrointesti-nales son bien reconocidos. En nuestro paĂs no existĂa un consenso respecto al diagnĂłstico,tratamiento y prevenciĂłn de la gastropatĂa y la enteropatĂa por AINE, por lo que la AsociaciĂłnMexicana de GastroenterologĂa reuniĂł a un grupo de expertos para establecer recomendacionesde utilidad para la comunidad mĂŠdica. En este consenso se emitieron 33 recomendaciones. Elconsenso destaca que el riesgo de toxicidad gastrointestinal de los AINE varĂa segĂşn el fĂĄrmacoempleado y su farmacocinĂŠtica, lo cual debe ser considerado al momento de su prescripciĂłn. Losfactores de riesgo de complicaciĂłn gastroduodenal por AINE son: antecedente de Ăşlcera pĂŠp-tica, edad mayor a 65 aËnos, dosis altas del AINE, infecciĂłn por Helicobacter pylori (H.pylori), ypresencia de comorbilidades graves. Los sĂntomas y el daËno gastroduodenal inducido por AINEson variables ya que puede cursar asintomĂĄtico o manifestarse como anemia por deficiencia dehierro, hemorragia, estenosis y perforaciĂłn. La cĂĄpsula endoscĂłpica y la enteroscopia son mĂŠto-dos diagnĂłsticos directos en la enteropatĂa por AINE. Respecto a la prevenciĂłn, se recomiendaprescribir la dosis mĂnima necesaria de un AINE para obtener el efecto deseado y durante elmenor tiempo. Finalmente, los inhibidores de la bomba de protones (IBP) representan el estĂĄn-dar de oro para la profilaxis y tratamiento de los efectos gastroduodenales, mas no son Ăştilesen la enteropatĂa
Dark Matter and Fundamental Physics with the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) is a project for a next-generation
observatory for very high energy (GeV-TeV) ground-based gamma-ray astronomy,
currently in its design phase, and foreseen to be operative a few years from
now. Several tens of telescopes of 2-3 different sizes, distributed over a
large area, will allow for a sensitivity about a factor 10 better than current
instruments such as H.E.S.S, MAGIC and VERITAS, an energy coverage from a few
tens of GeV to several tens of TeV, and a field of view of up to 10 deg. In the
following study, we investigate the prospects for CTA to study several science
questions that influence our current knowledge of fundamental physics. Based on
conservative assumptions for the performance of the different CTA telescope
configurations, we employ a Monte Carlo based approach to evaluate the
prospects for detection. First, we discuss CTA prospects for cold dark matter
searches, following different observational strategies: in dwarf satellite
galaxies of the Milky Way, in the region close to the Galactic Centre, and in
clusters of galaxies. The possible search for spatial signatures, facilitated
by the larger field of view of CTA, is also discussed. Next we consider
searches for axion-like particles which, besides being possible candidates for
dark matter may also explain the unexpectedly low absorption by extragalactic
background light of gamma rays from very distant blazars. Simulated
light-curves of flaring sources are also used to determine the sensitivity to
violations of Lorentz Invariance by detection of the possible delay between the
arrival times of photons at different energies. Finally, we mention searches
for other exotic physics with CTA.Comment: (31 pages, Accepted for publication in Astroparticle Physics
On the constraints violation in forward dynamics of multibody systems
It is known that the dynamic equations of motion for constrained mechanical multibody systems are frequently formulated using the Newton-Eulerâs approach, which is augmented with the acceleration constraint equations. This formulation results in the establishment of a mixed set of partial differential and algebraic equations, which are solved in order to predict the dynamic behavior of general multibody systems. The classical resolution of the equations of motion is highly prone to constraints violation because the position and velocity constraint equations are not fulfilled. In this work, a general and comprehensive methodology to eliminate the constraints violation at the position and velocity levels is offered. The basic idea of the described approach is to add corrective terms to the position and velocity vectors with the intent to satisfy the corresponding kinematic constraint equations. These corrective terms are evaluated as function of the Moore-Penrose generalized inverse of the Jacobian matrix and of the kinematic constraint equations. The described methodology is embedded in the standard method to solve the equations of motion based on the technique of Lagrange multipliers. Finally, the effectiveness of the described methodology is demonstrated through the dynamic modeling and simulation of different planar and spatial multibody systems. The outcomes in terms of constraints violation at the position and velocity levels, conservation of the total energy and computational efficiency are analyzed and compared with those obtained with the standard Lagrange multipliers method, the Baumgarte stabilization method, the augmented Lagrangian formulation, the index-1 augmented Lagrangian and the coordinate partitioning method.The first author expresses his gratitude to the Portuguese Foundation for Science and Technology through the PhD grant (PD/BD/114154/2016). This work has been supported by the Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 â Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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