Resistencia al esfuerzo cortante en suelos pumíticos

La mayoría de los suelos que se encuentran en el Área Metropolitana de Guadalajara provienen principalmente de la caldera de La Primavera cuya última actividad se dio en tiempos geológicos recientes, hace 30,000 años aproximadamente. Actualmente la técnica de penetración estándar (SPT) es la más utilizada para la exploración del subsuelo y para la obtención de los parámetros de comportamiento mecánico; sin embargo, hay pocos trabajos que relacionen los datos obtenidos con esta técnica y la resistencia al esfuerzo cortante de los suelos de Guadalajara. Como etapa inicial para correlacionar estos valores, se presenta este trabajo, se realizaron pruebas de corte directo y triaxiales variando características físicas de los suelos y registrando la resistencia al esfuerzo cortante máxima y residual: se varió su granulometría, peso volumétrico seco y contenido de agua. Se determinó la influencia de estos factores con la resistencia al esfuerzo cortante. El mejor ajuste se dio con el Peso Volumétrico Seco. Además algunas pruebas demuestran que los suelos presentan una resistencia por cohesión que debería ser considerada al estudiar el comportamiento de estos suelos. En un trabajo posterior se deberán relacionar estos resultados con los datos obtenidos por medio de la prueba de penetración estándar

Correlación entre propiedades mecánicas y propiedades físicas en suelos pumíticos no saturados

Se realizaron diversas pruebas de caracterización física (granulometría, contenido de agua, densidad, etc.) y de comportamiento mecánico (corte directo y permeabilidad) en suelos pumíticos que representan la gran mayoría de los suelos (depósitos piroclásticos) de la zona metropolitana de guadalajara. Dichos suelos están conformados por arenas limosas y cenizas provenientes de la actividad volcánica reciente en el valle de Atemajac. Se llevó a cabo un análisis de regresión multivariable para poder obtener expresiones matemáticas que resolvieran las propiedades mecánicas de estos suelos a partir de sus propiedades índices. Las expresiones que presentamos son ecuaciones prácticas que proponemos como una forma alternativa para obtener la resistencia al esfuerzo cortante y la permeabilidad de los suelos pumíticos, a partir de propiedades físicas sencillas de obtener

Diferentes ecuaciones de falla al cortante en suelos pumíticos no saturados

Se realizaron pruebas de corte directo en suelos pumíticos que representan a la gran mayoría de los suelos (depósitos piroclásticos) de la Zona Metropolitana de Guadalajara. Dichos suelos están conformados por arenas limosas y cenizas provenientes de la actividad volcánica reciente (geológicamente hablando) en el valle de Atemajac. Para las pruebas de corte directo se utilizaron gráficas esfuerzo cortante vs esfuerzo normal y se resolvió trabajar con cuatro variables independientes: granulometría (D10 y % Que pasa malla No.200), contenido de agua (w), densidad y esfuerzo efectivo. De este modo las variables dependientes resultan ser: esfuerzo cortante, ángulo de fricción y cohesión

Mar project: a project for monitoring Antarctic and subantarctic ozone layer

Ponencia presentada en: 3ª Asamblea Hispano Portuguesa de Geodesia y Geofisica, celebrada en Valencia en 2002The co-ordinated Project presented attempts to increase the limited information existing nowadays about the space-time distribution of NO2, O3, OClO constituents and ultraviolet radiation over Antarctic and sub-Antarctica regions. In the framework of projects financed in previous convocations of the CICYT (PNIA) the installation of three spectrometers in the Argentinean bases of Belgrano, Marambio and Ushuaia was carried out (1994) and an ozosondeador in Belgrano (1999) for the INTA as well as the installation of three radiometers for the INM in the same stations (1999) thanks to the existent agreements of scientific collaboration between INTA and DNA/IAA and INM with DNA/IAA. Both networks of instruments, complementary and co-ordinated, will allow to reach the following objectives: To observe and to characterise the space and temporal evolution so much of the O3, NO2 and OClO like of the ultraviolet radiation in those regions during next years, to carry out a dynamic study of the Antarctic polar vortex in which is analysed as the daily evolution of this it affects at the O3, NO2, OClO and spectral UV radiation giving special attention to populated regions of the South Hemisphere (Ushuaia) and to carry out an exhaustive control of quality of the data obtained by the instruments that assure us to be able to use the measures obtained by the same ones to approach studies of tendencies in next years. Independently of the scientific interest of the previously mentioned objectives, under the atmospheric point of view, this project will provide an unique information to other Spanish groups in Antarctic biology research

Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

Background: The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods: Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results: Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion: Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistance

A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector

A search for the dimuon decay of the Standard Model (SM) Higgs boson is performed using data corresponding to an integrated luminosity of 139 fb(-1) collected with the ATLAS detector in Run 2 pp collisions at root s = 13 TeV at the Large Hadron Collider. The observed (expected) significance over the background-only hypothesis for a Higgs boson with a mass of 125.09 GeV is 2.0 sigma (1.7 sigma). The observed upper limit on the cross section times branching ratio for pp -> H -> mu mu is 2.2 times the SM prediction at 95% confidence level, while the expected limit on a H -> mu mu signal assuming the absence (presence) of a SM signal is 1.1(2.0). The best-fit value of the signal strength parameter, defined as the ratio of the observed signal yield to the one expected in the SM, is mu = 1.2 +/- 0.6. (C) 2020 The Author(s). Published by Elsevier B.V

Searches for lepton-flavour-violating decays of the Higgs boson into eτ and μτ in \sqrt{s} = 13 TeV pp collisions with the ATLAS detector

Abstract This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy s $$\sqrt{s}$$ = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Leptonic (τ → ℓνℓντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, B $$\mathcal{B}$$ (H → eτ) < 0.20% (0.12%) and B $$\mathcal{B}$$ (H → μτ ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → μτ signals. The best-fit branching ratio difference, B $$\mathcal{B}$$ (H → μτ) → B $$\mathcal{B}$$ (H → eτ), measured with the Symmetry method in the channel where the τ-lepton decays to leptons, is (0.25 ± 0.10)%, compatible with a value of zero within 2.5σ

Measurement of the H → γ γ and H → ZZ∗ → 4 cross-sections in pp collisions at √s = 13.6 TeV with the ATLAS detector

The inclusive Higgs boson production cross section is measured in the di-photon and the Z Z∗ → 4 decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre of-mass energy of √s = 13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the chan nel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,γ γ = 76+14 −13 fb, and σfid,4 = 2.80 ± 0.74 fb, in agreement with the corresponding Standard Model predic tions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two chan nels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ (pp → H) = 67+12 −11 pb and 46±12 pb at 13.6 TeV from the di-photon and Z Z∗ → 4 measurements respectively. The two measure ments are combined into a total cross-section measurement of σ (pp → H) = 58.2±8.7 pb, to be compared with the Stan dard Model prediction of σ (pp → H)SM = 59.9 ± 2.6 p

Search for new phenomena in three- or four-lepton events in pp collisions at root s=13 TeV with the ATLAS detector

A search with minimal model dependence for physics beyond the Standard Model in events featuring three or four charged leptons (3l and 4l, l = e, mu) is presented. The analysis aims to be sensitive to a wide range of potential new-physics theories simultaneously. This analysis uses data from pp collisions delivered by the Large Hadron Collider at a centre-of-mass energy of root s = 13 TeV and recorded with the ATLAS detector, corresponding to the full Run 2 dataset of 139 fb(-1). The 3l and 4l phase space is divided into 22 event categories according to the number of leptons in the event, the missing transverse momentum, the invariant mass of the leptons, and the presence of leptons originating from a Z-boson candidate. These event categories are analysed independently for the presence of deviations from the Standard Model. No statistically significant deviations from the Standard Model predictions are observed. Upper limits for all signal regions are reported in terms of the visible cross-section. Crown Copyright (C) 2021 Published by Elsevier B.V