2,607 research outputs found

    Evaluation of the Detectability of Electromechanical Faults in Induction Motors Via Transient Analysis of the Stray Flux

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    © 1972-2012 IEEE. The stray flux that is present in the vicinity of an induction motor is a very interesting information source to detect several types of failures in these machines. The analysis of this quantity can be employed, in some cases, as a supportive tool to complement the diagnosis provided by other quantities. In other cases, when no other motor quantities are available, stray flux analysis can become one of the few alternatives to evaluate the motor condition. Its noninvasive nature, low cost, and easy implementation makes it a very interesting option that requires further investigation. The aim of this work is to evaluate the suitability of the stray flux analysis under the starting transient as a way to detect certain faults in induction motors (broken rotor bars and misalignments), even when these types of faults coexist in the motor. To this end, advanced signal processing tools will be applied. Several positions of the flux sensors are considered in this study. Also, for the first time, a fault indicator based on the stray flux analysis under the starting is introduced and its sensitivity is compared versus other indicators relying on other quantities. It must be emphasized that, since the capture of the transient and steady-state flux signals can be carried out in the same measurement, the application of the approach presented in this work is straightforward and its derived information may become crucial for the diagnosis of some faults.Ministerio de Economía y Competitividad’ (MINECO) and FEDER program in the framework of the ‘Proyectos I+D del Subprograma de Generación de Conocimiento, Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia’ (ref: DPI2014-52842-P)

    Efficacy and safety of lurbinectedin and doxorubicin in relapsed small cell lung cancer. Results from an expansion cohort of a phase I study

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    Background A phase I study found remarkable activity and manageable toxicity for doxorubicin (bolus) plus lurbinectedin (1-h intravenous [i.v.] infusion) on Day 1 every three weeks (q3wk) as second-line therapy in relapsed small cell lung cancer (SCLC). An expansion cohort further evaluated this combination. Patients and methods Twenty-eight patients with relapsed SCLC after no more than one line of cytotoxic-containing chemotherapy were treated: 18 (64%) with sensitive disease (chemotherapy-free interval [CTFI] ≥90 days) and ten (36%) with resistant disease (CTFI <90 days; including six with refractory disease [CTFI ≤30 days]). Results Ten patients showed confirmed response (overall response rate [ORR] = 36%); median progression-free survival (PFS) = 3.3 months; median overall survival (OS) = 7.9 months. ORR was 50% in sensitive disease (median PFS = 5.7 months; median OS = 11.5 months) and 10% in resistant disease (median PFS = 1.3 months; median OS = 4.6 months). The main toxicity was transient and reversible myelosuppression. Treatment-related non-hematological events (fatigue, nausea, decreased appetite, vomiting, alopecia) were mostly mild or moderate. Conclusion Doxorubicin 40 mg/m(2) and lurbinectedin 2.0 mg/m(2) on Day 1 q3wk has shown noteworthy activity in relapsed SCLC and a manageable safety profile. The combination is being evaluated as second-line therapy for SCLC in an ongoing, randomized phase III trial. Clinical trial registration www.ClinicalTrials.gov code: NCT01970540. Date of registration: 22 October, 2013

    Vector field and rotational curves in dark galactic halos

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    We study equations of a non-gauge vector field in a spherically symmetric static metric. The constant vector field with a scale arrangement of components: the time component about the Planck mass m_{Pl} and the radial component about M suppressed with respect to the Planck mass, serves as a source of metric reproducing flat rotation curves in dark halos of spiral galaxies, so that the velocity of rotation v_0 is determined by the hierarchy of scales: \sqrt{2} v_0^2= M/m_{Pl}, and M\sim 10^{12} GeV. A natural estimate of Milgrom's acceleration about the Hubble rate is obtained.Comment: 17 pages, iopart style, misprint remove

    Declínio de empatia e formação de estudantes de enfermagem

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    Indexación: Scopus.Objective: The objective of this article is to examine whether the levels of empathy fit the concept of empathic decline. Method: This was a non-experimental and cross-sectional study. Two populations of nursing students in two nursing programs were studied: Universidad San Sebastián (Santiago, Chile) and Universidad Mayor (Temuco, Chile). The original data on empathy, assessed by the Jeferson Scale of Empathy, were combined into a single data base. They were then analyzed by means of normality tests and homoscedasticity, Cronbach’s alpha, analysis of variance; the standard deviation of the dependent outcome measure (Sy.x) and the coefficient of determination (R2) were estimated. Results: The sample sizes from the two programs were 479 and 277, respectively. It was found that the distributions of the averages over the course of study for empathy (and its components) were constant, and in some cases increased. Conclusion: It was found that the distribution of the means of empathy in the nursing students analyzed did not conform to the classical empathic decline observed in other studies. Therefore, it is inferred that the traditional factors identified as causes of empathic erosion were not operating in the same way in the studied context.https://www.scielo.br/j/reeusp/a/YPfy3YRCCXwv7z8VPNZXjns/?lang=e

    Vector field as a quintessence partner

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    We derive generic equations for a vector field driving the evolution of flat homogeneous isotropic universe and give a comparison with a scalar filed dynamics in the cosmology. Two exact solutions are shown as examples, which can serve to describe an inflation and a slow falling down of dynamical ``cosmological constant'' like it is given by the scalar quintessence. An attractive feature of vector field description is a generation of ``induced mass'' proportional to a Hubble constant, which results in a dynamical suppression of actual cosmological constant during the evolution.Comment: 14 pages, LaTeX file, iopart class, discussion extended, reference adde

    Physics and Mathematics of Calogero particles

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    We give a review of the mathematical and physical properties of the celebrated family of Calogero-like models and related spin chains.Comment: Version to appear in Special Issue of Journal of Physics A: Mathematical and Genera

    Risk score for early risk prediction by cardiac magnetic resonance after acute myocardial infarction

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    [EN] Background: Cardiac magnetic resonance (CMR) performed early after ST-segment elevation myocardial infarction (STEMI) can improve major adverse cardiac event (MACE) risk prediction. We aimed to create a simple clinical-CMR risk score for early MACE risk stratification in STEMI patients. Methods: We performed a multicenter prospective registry of reperfused STEMI patients (n = 1118) in whom early (1-week) CMR-derived left ventricular ejection fraction (LVEF), infarct size and microvascular obstruction (MVO) were quantified. MACE was defined as a combined clinical endpoint of cardiovascular (CV) death, nonfatal myocardial infarction (NF-MI) or re-admission for acute decompensated heart failure (HF). Results: During a median follow-up of 5.52 [2.63-7.44] years, 216 first MACE (58 CV deaths, 71 NF-MI and 87 HF) were registered. Mean age was 59.3 +/- 12.3 years and most patients (82.8%) were male. Based on the four variables independently associated with MACE, we computed an 8-point risk score: time to reperfusion >4.15 h (1 point), GRACE risk score > 155 (3 points), CMR-LVEF 1.5 segments (1 point). This score permitted MACE risk stratification: MACE per 100 person-years was 1.96 in the low-risk category (0-2 points), 5.44 in the intermediate-risk category (3-5 points), and 19.7 in the high-risk category (6-8 points): p 4.15 h and GRACE risk score > 155) and CMR (LVEF 1.5 segments) variables allows for simple and straightforward MACE risk stratification early after STEMI. External validation should confirm the applicability of the risk score.This work was supported by the Instituto de Salud Carlos III and cofunded by Fondo Europeo de Desarrollo Regional (FEDER) (grants PI20/00637 and CIBERCV16/11/00486), "Marató TV3" [grant number 20153030-31-32], the Catalonian Society of Cardiology 2015, La Caixa Foundation [HR17-00527], and by Sociedad Española de Cardiología (grant SEC/FECINV-CLI 21/024). D.M. acknowledges financial support from the Conselleria d'Educació, Investigació, Cultura i Esport, Generalitat Valenciana (grants AEST/ 2019/037 and AEST/2020/029). J. G. acknowledges financial support from the Agencia Estatal de Investigación (grant FJC2020-043981-I / AEI/10.13039/501100011033).Marcos-Garcés, V.; Perez, N.; Gavara-Doñate, J.; Lopez-Lereu, MP.; Monmeneu, JV.; Rios-Navarro, C.; De Dios, E.... (2022). Risk score for early risk prediction by cardiac magnetic resonance after acute myocardial infarction. International Journal of Cardiology. 349:150-154. https://doi.org/10.1016/j.ijcard.2021.11.05015015434

    Determination of ππ\pi\pi scattering lengths from measurement of π+π−\pi^+\pi^- atom lifetime

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    The DIRAC experiment at CERN has achieved a sizeable production of π+π−\pi^+\pi^- atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave ππ\pi\pi scattering length difference ∣a0−a2∣=(.0.2533−0.0078+0.0080∣stat.−0.0073+0.0078∣syst)Mπ+−1|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1} has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure

    Magnetic resonance microscopy and correlative histopathology of the infarcted heart

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    Altres ajuts:The present study was supported by the EU Joint Programming Initiative 'A Healthy Diet for a Healthy Life' (JPI HDHL INTIMIC-085), Generalitat Valenciana (GV/2018/116), INCLIVA and Universitat de Valencia (program VLC-BIOCLINIC 20-nanomIRM-2016A).Delayed enhancement cardiovascular magnetic resonance (MR) is the gold-standard for non-invasive assessment after myocardial infarction (MI). MR microscopy (MRM) provides a level of detail comparable to the macro objective of light microscopy. We used MRM and correlative histopathology to identify infarct and remote tissue in contrast agent-free multi-sequence MRM in swine MI hearts. One control group (n = 3 swine) and two experimental MI groups were formed: 90 min of ischemia followed by 1 week (acute MI = 6 swine) or 1 month (chronic MI = 5 swine) reperfusion. Representative samples of each heart were analysed by contrast agent-free multi-sequence (T1-weighting, T2-weighting, T2*-weighting, T2-mapping, and T2*-mapping). MRM was performed in a 14-Tesla vertical axis imager (Bruker-AVANCE 600 system). Images from MRM and the corresponding histopathological stained samples revealed differences in signal intensities between infarct and remote areas in both MI groups (p-value < 0.001). The multivariable models allowed us to precisely classify regions of interest (acute MI: specificity 92% and sensitivity 80%; chronic MI: specificity 100% and sensitivity 98%). Probabilistic maps based on MRM images clearly delineated the infarcted regions. As a proof of concept, these results illustrate the potential of MRM with correlative histopathology as a platform for exploring novel contrast agent-free MR biomarkers after MI
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