109 research outputs found

    Dynamic Response of Wind Turbines to Theoretical 3D Seismic Motions Taking into Account the Rotational Component

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    We study the dynamic response of a wind turbine structure subjected to theoretical seismic motions, taking into account the rotational component of ground shaking. Models are generated for a shallow moderate crustal earthquake in the Madrid Region (Spain). Synthetic translational and rotational time histories are computed using the Discrete Wavenumber Method, assuming a point source and a horizontal layered earth structure. These are used to analyze the dynamic response of a wind turbine, represented by a simple finite element model. Von Mises stress values at different heights of the tower are used to study the dynamical structural response to a set of synthetic ground motion time historie

    Application surface of CPT, an advanced DInSAR displacement near Itoiz dam, Navarra, Spain

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    Itoiz reservoir is located in Navarra, northern Spain, being a newly constructed gravity dam that stores the water from the Irati and the Urrobi rivers. The dam has a total height of 121 m, a total length of 525 m and a maximum water storage volume of 410 hm3. The aim of this work is to study the surface displacement field during the impoundment of the Itoiz water reservoir. Orbital SAR Differential Interferometry (DInSAR) techniques have been proven to be a useful and powerful tool in tectonic areas for surveying subtle surface deformations over several years related to geodynamic phenomena. An advanced DInSAR observation technique, Coherent Pixel Technique (CPT), has been applied to study the existence of deformation in the dam area in order to obtain mean velocities and time series of deformation. We have studied the applicability of this technique to study the surface displacement field during the impoundment of the Itoiz water reservoir. Specifically, we focus on the analysis of the stability of the left slope of the reservoir. We have used ERS and ENVISAT descending and ascending images concerning to the 1992-2008 and 2003-2008 periods respectively. We compare the observation results with the displacement induced by water loading obtained using a theoretical model

    On the applicability of an advanced DInSAR techniques near Itoiz and Yesa reservoirs, Navarra, Spain

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    In this paper we show the applicability of orbital Synthetic Aperture Radar (SAR) Differential Interferometry (DInSAR) with multiple images for terrain deformation episodes monitoring. This paper is focused on the Coherent Pixels Technique (CPT). This technique has been tested with ERS SAR and ENVISAT ASAR data for the period 1992-2008 from The Itoiz and Yesa reservoirs. These ones, located in Navarra, northern Spain, are constructed gravity dams that stores the water from the Irati and the Urrobi rivers, and the AragĂłn river respectively. The results has been compared with theoretical results obtained using an analytical model

    The Mexican consensus on the diagnosis, treatment, and prevention of NSAID-induced gastropathy and enteropathy

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    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 analgĂ©sicas 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 mĂ©dica. En este consenso se emitieron 33 recomendaciones. Elconsenso destaca que el riesgo de toxicidad gastrointestinal de los AINE varĂ­a segĂșn el fĂĄrmacoempleado y su farmacocinĂ©tica, lo cual debe ser considerado al momento de su prescripciĂłn. Losfactores de riesgo de complicaciĂłn gastroduodenal por AINE son: antecedente de Ășlcera pĂ©p-tica, edad mayor a 65 a˜nos, dosis altas del AINE, infecciĂłn por Helicobacter pylori (H.pylori), ypresencia de comorbilidades graves. Los sĂ­ntomas y el da˜no 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 mĂ©to-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 Ăștilesen la enteropatĂ­a

    Scope and limitations of the irreversible thermodynamics and the solution diffusion models for the separation of binary and multi-component systems in reverse osmosis process

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    YesReverse osmosis process is used in many industrial applications ranging from solute-solvent to solvent-solvent and gaseous separation. A number of theoretical models have been developed to describe the separation and fluxes of solvent and solute in such processes. This paper looks into the scope and limitations of two main models (the irreversible thermodynamics and the solution diffusion models) used in the past by several researchers for solute-solvent feed separation. Despite the investigation of other complex models, the simple concepts of these models accelerate the feasibility of the implementation of reverse osmosis for different types of systems and variety of industries. Briefly, an extensive review of these mathematical models is conducted by collecting more than 70 examples from literature in this study. In addition, this review has covered the improvement of such models to make them compatible with multi-component systems with consideration of concentration polarization and solvent-solute-membrane interaction

    Consenso mexicano sobre diagnĂłstico, prevenciĂłn y tratamiento de la gastropatĂ­a y enteropatĂ­a por antiinflamatorios no esteroideos

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    MĂĄs de 30 millones de personas consumen diariamente antiinflamatorios no este-roideos (AINE) en el mundo y este consumo se ve incrementado a˜no tras a˜no. Aunque los AINEposeen propiedades analgĂ©sicas y antiinflamatorias, sus eventos adversos gastrointestinales sonbien reconocidos. En nuestro paĂ­s no existĂ­a un consenso respecto al diagnĂłstico, tratamientoy prevenciĂłn de la gastropatĂ­a y la enteropatĂ­a por AINE, por lo que la AsociaciĂłn Mexicana deGastroenterologĂ­a reuniĂł a un grupo de expertos para establecer recomendaciones de utilidadpara la comunidad mĂ©dica. En este consenso se emitieron 33 recomendaciones. El consensodestaca que el riesgo de toxicidad gastrointestinal de los AINE varĂ­a segĂșn el fĂĄrmaco empleadoy su farmacocinĂ©tica, lo cual debe ser considerado al momento de su prescripciĂłn. Los factoresde riesgo de complicaciĂłn gastroduodenal por AINE son: antecedente de Ășlcera pĂ©ptica, edadmayor de 65 a˜nos, dosis altas del AINE, infecciĂłn por Helicobacter pylori y presencia de comor-bilidades graves. Los sĂ­ntomas y el da˜no gastroduodenal inducido por AINE son variables, ya quepuede cursar asintomĂĄtico o manifestarse como anemia por deficiencia de hierro, hemorragia,estenosis y perforaciĂłn. La cĂĄpsula endoscĂłpica y la enteroscopia son mĂ©todos diagnĂłsticosdirectos en la enteropatĂ­a por AINE. Respecto a la prevenciĂłn, se recomienda prescribir la dosismĂ­nima necesaria de un AINE para obtener el efecto deseado y durante el menor tiempo. PorĂșltimo, los inhibidores de la bomba de protones representan el estĂĄndar de oro para la profilaxisy tratamiento de los efectos gastroduodenales, mas no son Ăștiles en la enteropatĂ­

    Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at √s = 8 TeV with the ATLAS detector

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    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb −1 . No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B → Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B → Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T 5/3 , with subsequent decay T 5/3 → Wt, sets an observed (expected) 95% C.L. lower limit on the T 5/3 mass of 840 GeV (780 GeV)

    Measurement of the cross section of high transverse momentum Z→bb̄ production in proton–proton collisions at √s = 8 TeV with the ATLAS detector

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    This Letter reports the observation of a high transverse momentum Z→bb̄ signal in proton–proton collisions at √s=8 TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb−Âč. The Z→bb̄ decay is reconstructed from a pair of b -tagged jets, clustered with the anti-ktkt jet algorithm with R=0.4R=0.4, that have low angular separation and form a dijet with pT>200 GeVpT>200 GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be σZ→bbÂŻfid=2.02±0.20 (stat.) ±0.25 (syst.)±0.06 (lumi.) pb=2.02±0.33 pb, in good agreement with next-to-leading-order theoretical predictions

    Measurement of the branching ratio Γ(Λb⁰ → ψ(2S)Λ0)/Γ(Λb⁰ → J/ψΛ0) with the ATLAS detector

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    An observation of the Λb0→ψ(2S)Λ0\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0 decay and a comparison of its branching fraction with that of the Λb0→J/ψΛ0\Lambda_b^0 \rightarrow J/\psi \Lambda^0 decay has been made with the ATLAS detector in proton--proton collisions at s=8 \sqrt{s}=8\,TeV at the LHC using an integrated luminosity of 20.6 20.6\,fb−1^{-1}. The J/ψJ/\psi and ψ(2S)\psi(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→pπ−\Lambda^0\rightarrow p\pi^- decay is exploited for the Λ0\Lambda^0 baryon reconstruction. The Λb0\Lambda_b^0 baryons are reconstructed with transverse momentum pT>10 p_{\rm T}>10\,GeV and pseudorapidity ∣η∣<2.1|\eta|<2.1. The measured branching ratio of the Λb0→ψ(2S)Λ0\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0 and Λb0→J/ψΛ0\Lambda_b^0 \rightarrow J/\psi \Lambda^0 decays is Γ(Λb0→ψ(2S)Λ0)/Γ(Λb0→J/ψΛ0)=0.501±0.033(stat)±0.019(syst)\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0) = 0.501\pm 0.033 ({\rm stat})\pm 0.019({\rm syst}), lower than the expectation from the covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table, published on Physics Letters B 751 (2015) 63-80. All figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08

    Measurement of the View the tt production cross-section using eÎŒ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a measurement of the inclusive top quark pair production cross-section (σttÂŻ) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σttÂŻ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σttÂŻ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
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