2,400 research outputs found

    Heat loss prediction of a confined premixed jet flame using a conjugate heat transfer approach

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    The presented work addresses the investigation of the heat loss of a confined turbulent jet flame in a lab-scale combustor using a conjugate-heat transfer approach and large-eddy simulation. The analysis includes the assessment of the principal mechanisms of heat transfer in this combustion chamber: radiation, convection and conduction of heat over walls. A staggered approach is used to couple the reactive flow field to the heat conduction through the solid and both domains are solved using two implementations of the same code. Numerical results are compared against experimental data and an assessment of thermal boundary conditions to improve the prediction of the reactive flow field is given.The research leading to these results has received funding through the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7, 2007–2013) under the Grant agreement No. FP7-290042 for the project COPA-GT as well as the European Union’s Horizon 2020 Programme (2014–2020) and from Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E Project, Grant agreement No. 689772. The authors thankfully acknowledge the computer resources, technical expertise and assistance provided by the Red Española de Supercomputación (RES). Finally, the authors would like to thank O. Lammel for the useful discussions and kindly providing the data for the comparison.Peer ReviewedPostprint (published version

    A functional analysis of two transdiagnostic, emotion-focused interventions on nonsuicidal self-injury

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    OBJECTIVE: Nonsuicidal self-injury (NSSI) is prevalent and associated with clinically significant consequences. Developing time-efficient and cost-effective interventions for NSSI has proven difficult given that the critical components for NSSI treatment remain largely unknown. The aim of this study was to examine the specific effects of mindful emotion awareness training and cognitive reappraisal, 2 transdiagnostic treatment strategies that purportedly address the functional processes thought to maintain self-injurious behavior, on NSSI urges and acts. METHOD: Using a counterbalanced, combined series (multiple baseline and data-driven phase change) aggregated single-case experimental design, the unique and combined impact of these 2 4-week interventions was evaluated among 10 diagnostically heterogeneous self-injuring adults. Ecological momentary assessment was used to provide daily ratings of NSSI urges and acts during all study phases. RESULTS: Eight of 10 participants demonstrated clinically meaningful reductions in NSSI; 6 participants responded to 1 intervention alone, whereas 2 participants responded after the addition of the alternative intervention. Group analyses indicated statistically significant overall effects of study phase on NSSI, with fewer NSSI urges and acts occurring after the interventions were introduced. The interventions were also associated with moderate to large reductions in self-reported levels of anxiety and depression, and large improvements in mindful emotion awareness and cognitive reappraisal skills. CONCLUSIONS: Findings suggest that brief mindful emotion awareness and cognitive reappraisal interventions can lead to reductions in NSSI urges and acts. Transdiagnostic, emotion-focused therapeutic strategies delivered in time-limited formats may serve as practical yet powerful treatment approaches, especially for lower-risk self-injuring individuals.Dr. Barlow receives royalties from Oxford University Press, Guilford Publications Inc., Cengage Learning, and Pearson Publishing. Grant monies for various projects come from the National Institute of Mental Health (F31MH100761), the National Institute of Alcohol and Alcohol Abuse, and Colciencias (Government of Columbia Initiative for Science, Technology, and Health Innovation). Consulting and honoraria during the past several years have come from the Agency for Healthcare Research and Quality, the Foundation for Informed Medical Decision Making, the Department of Defense, the Renfrew Center, the Chinese University of Hong Kong, Universidad Catolica de Santa Maria (Arequipa, Peru), New Zealand Psychological Association, Hebrew University of Jerusalem, Mayo Clinic, and various American Universities. (F31MH100761 - National Institute of Mental Health; National Institute of Alcohol and Alcohol Abuse; Colciencias (Government of Columbia Initiative for Science, Technology, and Health Innovation))Accepted manuscrip

    A Multi-wavelength Study of the Host Environment of SMBHB 4C+37.11

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    4C+37.11, at z=0.055 shows two compact radio nuclei, imaged by VLBI at 7mas separation, making it the closest known resolved super-massive black hole binary (SMBHB). An important question is whether this unique object is young, caught on the way to a gravitational in-spiral and merger, or has `stalled' at 7pc. We describe new radio/optical/X-ray observations of the massive host and its surrounding X-ray halo. These data reveal X-ray/optical channels following the radio outflow and large scale edges in the X-ray halo. These structures are promising targets for further study which should elucidate their relationship to the unique SMBHB core.Comment: To appear in the Astrophysical Journa

    Antispasmodic effects and action mechanism of essential oil of Chrysactinia mexicana A. Gray on rabbit ileum

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    The Chrysactinia mexicana A. Gray (C. mexicana) plant is used in folk medicine to treat fever and rheumatism; it is used as a diuretic, antispasmodic; and it is used for its aphrodisiac properties. This study investigates the effects of the essential oil of C. mexicana (EOCM) on the contractility of rabbit ileum and the mechanisms of action involved. Muscle contractility studies in vitro in an organ bath to evaluate the response to EOCM were performed in the rabbit ileum. EOCM (1–100 µg·mL-1) reduced the amplitude and area under the curve of spontaneous contractions of the ileum. The contractions induced by carbachol 1 µM, potassium chloride (KCl) 60 mM or Bay K8644 1 µM were reduced by EOCM (30 µg·mL-1). Apamin 1 µM and charybdotoxin 0.01 µM decreased the inhibition induced by EOCM. The d-cAMP 1 µM decreased the inhibition induced by EOCM. l-NNA 10 µM, Rp-8-Br-PET-cGMPS 1 µM, d, l-propargylglycine 2 mM, or aminooxyacetic acid hemihydrochloride 2 mM did not modify the EOCM effect. In conclusion, EOCM induces an antispasmodic effect and could be used in the treatment of intestinal spasms or diarrhea processes. This effect would be mediated by Ca2+, Ca2+-activated K+ channels and cAMP

    Three dimensional magnetic field structure of six parsec-scale active galactic nuclei jets

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    The parsec-scale Faraday rotation measure (RM) distribution of six "blazars" is investigated using multi-frequency (4.6--43 GHz) polarization observations taken on 2006 July 2 with the VLBA. Analysis of the RM provides the direction of the line-of-sight (LoS) magnetic field component, as well as the intrinsic 2-D polarization distribution on the plane of the sky. Our results show that the magnitude of the core RM increases systematically with frequency, and is well described by a power-law, where |RM_{core}| \propto \nu^a. Our measured values of aa vary from 0.9 to 3.8, providing information on the assumed power-law fall-off in the electron density with distance from the central engine for each source. RM gradients were detected across the jets of three sources, supporting the presence of helical magnetic fields in a sheath or boundary layer surrounding their jets. We find a bi-modal distribution of the intrinsic jet polarization orientation; either aligned or orthogonal to the jet direction. A helical magnetic field geometry can neatly explain both the bi-model distribution of the jet polarization orientation and the ordered polarization structure detected on these scales. In half the sources, we find that the core RM changes sign with distance from the central engine. We provide an explanation for this by considering a boundary layer of Faraday rotating material threaded by a helical magnetic field, where bends in the relativistic jet or accelerating/decelerating flows give rise to changes in the dominant LoS components of the magnetic field, which in turn gives rise to different signs of the RM. (abridged)Comment: 29 pages, 26 figures, accepted for publication in MNRAS, v2 -> proof corrections: references update

    Estrategias basadas en el aprendizaje cooperativo y en la metrologĂ­a para el laboratorio en el trabajo experimental

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    Se proponen estrategias de secuencia didáctica para mejorar el trabajo experimental con la finalidad de conseguir los objetivos de aprendizaje y los contenidos propuestos. Las estrategias están basadas en el aprendizaje cooperativo y en un control estricto en las mediciones

    Rotation-Measures across Parsec-scale Jets of FRI radio galaxies

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    We present the results of a parsec-scale polarization study of three FRI radio galaxies - 3C66B, 3C78 and 3C264 - obtained with the Very Long Baseline Array at 5, 8 and 15 GHz. Parsec-scale polarization has been detected in a large number of beamed radio-loud active galactic nuclei, but in only a handful of the relatively unbeamed radio galaxies. We report here the detection of parsec-scale polarization at one or more frequencies in all three FRI galaxies studied. We detect Faraday rotation measures of the order of a few hundred rad/m^2 in the nuclear jet regions of 3C78 and 3C264. In 3C66B polarization was detected at 8 GHz only. A transverse rotation measure gradient is observed across the jet of 3C78. The inner-jet magnetic field, corrected for Faraday rotation, is found to be aligned along the jet in both 3C78 and 3C264, although the field becomes orthogonal further from the core in 3C78. The RM values in 3C78 and 3C264 are similar to those previously observed in nearby radio galaxies. The transverse RM gradient in 3C78, the increase in the degree of polarization at the jet edge, the large rotation in the polarization angles due to Faraday rotation and the low depolarization between frequencies, suggests that a layer surrounding the jet with a sufficient number of thermal electrons and threaded by a toroidal or helical magnetic field is a good candidate for the Faraday rotating medium. This suggestion is tentatively supported by Hubble Space Telescope optical polarimetry but needs to be examined in a greater number of sources.Comment: Accepted for publication in The Astrophysical Journal, March 2009 - 20 v694 issu
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