4,074 research outputs found
The complex dust formation zone of the AGB star IRC+10216 probed with CARMA 0.25 arcsec angular resolution molecular observations
We present low spectral resolution molecular interferometric observations at
1.2 mm obtained with the Combined Array for Research in Millimetre-wave
Astronomy (CARMA) towards the C-rich AGB star IRC+10216. We have mapped the
emission of several lines of SiS, H13CN, SiO, and SiC2 in the ground and first
excited vibrational states with a high angular resolution of 0.25 arcsec. These
observations have allowed us to partially resolve the emission of the envelope
at distances from the star <50 stellar radii (R*), where the stellar wind is
mainly accelerated. The structure of the molecular emission has been modelled
with a 3D radiation transfer code. The emission of line SiS(v=0,J=14-13) is
best reproduced with a set of maser emitting arcs arranged between 5 and 20 R*.
The abundance of H13CN with respect to H2 decreases from 8e-7 at 1-5 R* to 3e-7
at 20 R*. The SiO observations are explained with an abundance <2e-8 in the
shell-like region between 1 and 5 R*. At this point, the SiO abundance sharply
increases up to (2-3)e-7. The vibrational temperature of SiO increases by a
factor of 2 due North-East between 20 and 50 R*. SiC2 is formed at the stellar
surface with an abundance of 8e-7 decreasing down to 8e-8 at 20 R* probably due
to depletion on to dust grains. Several asymmetries are found in the abundance
distributions of H13CN, SiO, and SiC2 which define three remarkable directions
(North-East, South-Southwest, and South-East) in the explored region of the
envelope. There are some differences between the red- and blue-shifted
emissions of these molecules suggesting the existence of additional asymmetries
in their abundance distributions along the line-of-sight.Comment: 22 pages, 16 figures, 9 tables, accepted for publication in MNRA
Datasets on technological GHG emissions mitigation options for the agriculture sector
The 2030 EU policy framework for climate and energy confirms that all sectors, including agriculture, should contribute to climate stabilisation and greenhouse gas (GHG) emission reduction in the most cost-effective way. Since 2009, the European Commission's Joint Research Centre (JRC) analyses the economic impact of GHG mitigation policy options for EU agriculture. However, the lack of precise, integrated and harmonised data on the current and potential uptake, cost-effectiveness and GHG emissions reduction potential of technological (i.e. technical and management based) mitigation options hampers the analysis of the economic impacts of GHG mitigation in agriculture. Against this background, the JRC organised a workshop in Seville on 14th June 2016 which gathered European Commission staff and experts from diverse international institutions aiming to: i) identify current activities conducted by research institutes on the building of datasets for GHG mitigation technologies and their state and development, ii) establish synergies and working mechanisms among the different institutions working on the topic, iii) identify which are the current gaps and limitations of existing datasets and models and, iv) conceive a roadmap to build possible new datasets per mitigation technology. The present report is based on the workshop results and concludes on how to move forward.JRC.D.4-Economics of Agricultur
Do measures of physical function enhance the prediction of persistent pain and disability following a whiplash injury?:Protocol for a prospective observational study in Spain
INTRODUCTION: Not all factors that predict persistent pain and disability following whiplash injury are known. In particular, few physical factors, such as changes in movement and muscle behaviour, have been investigated. The aim of this study is to identify predictive factors that are associated with the development of persistent pain and disability following a whiplash injury by combining contemporary measures of physical function together with established psychological and pain-related predictive factors.METHODS AND ANALYSIS: A prospective observational study will recruit 150 consecutive eligible patients experiencing whiplash-related symptoms, admitted to a private physiotherapy clinic in Spain within 15 days of their whiplash injury. Poor outcome will be measured using the Neck Disability Index (NDI), defined as an NDI score of 30% or greater at 6 months post injury. Candidate predictors, including demographic characteristics, injury characteristics, pain characteristics, self-reported psychosocial factors and physical factors, will be collected at baseline (within 15 days of inception). Regression analyses will be performed to identify factors that are associated with persistent neck pain and disability over the study period.ETHICS AND DISSEMINATION: The project has been approved by the Ethics Committee of the province of Malaga, Spain (#30052019). The results of this study will be published in peer-reviewed journals.</p
Optimización del sistema de ventilación y la calidad de aire en la Empresa Minera Artesanal La Chira S. R. L.
En la siguiente investigación tiene como principal objetivo Optimizar el sistema de
ventilación en la empresa minera Miarlachi acorde al reglamento de seguridad y salud
ocupacional, la presente investigación es de tipo aplicativo, por otro lado por su profundidad
de investigación es de tipo descriptiva, de tal modo que se propone investigar el sistema
actual de ventilación, asà mismo es de tipo No Experimental – Cuantitativa, puesto que no
se manipularán las variables y se realizarán toma de datos como el flujo de aire y gases
presentes en las labores, como la presencia de gas Metano (CH4), Monóxido de carbono
(CO), Dióxido de carbono (NO2) y Oxigeno (O2), por otra parte se concluye la ineficiencia
del sistema actual de ventilación con un caudal de 5292,32 cfm no apto para el buen
desempeño de los colaboradores que trabajan en el frente de extracción, asà mismo se llegó
a calcular y simular en el software Ventsim el caudal necesario en la labor de acorde al
número de trabajadores y parámetros correspondientes con un requerimiento de 8279,5448
cfm. Por ende es necesario implementar un nuevo sistema de ventilación en el nivel principal
de la unidad minera, que cumpla con los estándares de acuerdo con el reglamento de
seguridad y salud ocupacional
Early postoperative complications of transvaginal access in minimally invasive sigmoid colon procedures
Objectives: The aim of the study was to evaluate early (the first 30 days) postoperative complications after transvaginal resection of the sigmoid colon. Material and Methods: A total of 23 laparoscopy-assisted transvaginal resections of the sigmoid colon and 1 NOTES transvaginal sigmoid resection were performed in the course of 3 years. Postoperative complications were recorded in a prospective manner. Results: In the group of 24 patients operated on using the transvaginal approach, 6 (25%) complications were recorded, including 3 urinary tract infections, 2 vaginal bleedings, and 1 abdominal trocar site hernia. Conclusion: Early postoperative complication rate after transvaginal resection of the sigmoid colon is relatively low and the clinical complications are not severe
Use of organo-montmorillonite for the nitrate retention in water: Influence of alkyl length of loaded surfactants
The removal of NO3− from water was performed and compared among four organo-montmorillonites (OMt) with quaternary amine surfactants of different chain lengths [octadecyl trimethyl-(ODTMA), hexadecyl trimethyl-(HDTMA), tetradecyl trimethyl-(TDTMA) and dodecyl trimethyl-ammonium (DDTMA)] and loadings [100%, 200%, 400% of the Mt cation exchange capacity (CEC)]. The maximum adsorption of NO3− was attained by the long chain length surfactants (64 and 100 mg NO3− ions per gram of OMt, for HDTMA and ODTMA, respectively) with initial loading of 400% with respect to the CEC of Mt. The short chain length surfactants (DDTMA and TDTMA) did not show adsorption of NO3− except for TDTMA 400 sample. The NO3− adsorption produced a slight expansion of the interlayer thickness of the OMt samples loaded with long-chain surfactants that was assigned to the entrance of NO3− by a synergic effect with these surfactants. The decrease of the negative zeta potential, found for OMt samples relative to that of Mt sample, was attributed to the surfactant chain length rather than to the actual surfactant loaded amounts, which allowed attaining positive zeta potential values for the OMt loaded with long-chain surfactants. The NO3− adsorption on OMt samples caused a slight decrease in the positive zeta potential values, reflecting the external surface coating by NO3−. For long-chain molecules, this behaviour also indicated the formation of greater interactions such as ion pairs between the positive polar group of the surfactant and NO3− ions.Fil: Jaworski, MarÃa Angélica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de IngenierÃa; ArgentinaFil: Flores, Federico Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; ArgentinaFil: Fernandez, Mariela Alejandra. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; ArgentinaFil: Casella, Mónica Laura. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Torres Sanchez, Rosa Maria. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de TecnologÃa de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de TecnologÃa de Recursos Minerales y Cerámica; Argentin
Influence of non-Consecutive Bar Breakages in Motor Current Signature Analysis for the Diagnosis of Rotor Faults in Induction Motors
(c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Studies of rotor asymmetries in squirrel-cage induction motors have traditionally focused on analyses of the effects of the breakage of adjacent bars on the magnetic field and current spectrum. However, major motor manufacturers have reported cases where damaged bars are randomly distributed around the rotor perimeter of large HV machines. In some of these cases, the motors were being monitored under maintenance programs based on motor current signature analysis (MCSA), and the degree of degradation found in the rotor was much greater than that predicted by analysis of their current spectra. For this reason, a complete study was carried out, comprising a theoretical analysis, as well as simulation and tests, to investigate the influence that the number and location of faulty bars has on the traditional MCSA diagnosis procedure. From the theoretical analysis, based on the application of the fault-current approach and space-vector theory, a very simple method is deduced, which enables the left sideband amplitude to be calculated for any double bar breakage, per unit of the sideband amplitude corresponding to a single breakage. The proposed methodology is generalized for the estimation of the sideband amplitude in the case of multiple bar breakages and validated by simulation using a finite-element-based model, as well as by laboratory tests.This work was supported by the Spanish Ministerio de Educacion y Ciencia under ´ the framework of the Programa Nacional de proyectos de Investigacion Funda- ´mental Project Reference DPI2008-06583/DPI. Paper no. TEC-00393-2008Riera-Guasp, M.; Fernandez Cabanas, M.; Antonino-Daviu, J.; Pineda-Sanchez, M.; Rojas GarcÃa, CH. (2010). Influence of non-Consecutive Bar Breakages in Motor Current Signature Analysis for the Diagnosis of Rotor Faults in Induction Motors. IEEE Transactions on Energy Conversion. 25(1):80-89. https://doi.org/10.1109/TEC.2009.2032622S808925
Two Different Populations within the Healthy Elderly: Lack of Conflict Detection in Those at Risk of Cognitive Decline
During healthy aging, inhibitory processing is affected at the sensorial, perceptual, and cognitive levels. The assessment of event-related potentials (ERPs) during the Stroop task has been used to study age-related decline in the efficiency of inhibitory processes. Studies using ERPs have found that the P300 amplitude increases and the N500 amplitude is attenuated in healthy elderly adults compared to those in young adults. On the other hand, it has been reported that theta excess in resting EEG with eyes closed is a good predictor of cognitive decline during aging 7 years later, while a normal EEG increases the probability of not developing cognitive decline. The behavioral and ERP responses during a Counting-Stroop task were compared between 22 healthy elderly subjects with normal EEG (Normal-EEG group) and 22 healthy elderly subjects with an excess of EEG theta activity (Theta-EEG group). Behaviorally, the Normal-EEG group showed a higher behavioral interference effect than the Theta-EEG group. ERP patterns were different between the groups, and two facts are highlighted: (a) the P300 amplitude was higher in the Theta-EEG group, with both groups showing a P300 effect in almost all electrodes, and (b) the Theta-EEG group did not show an N500 effect. These results suggest that the diminishment in inhibitory control observed in the Theta-EEG group may be compensated by different processes in earlier stages, which would allow them to perform the task with similar efficiency to that of participants with a normal EEG. This study is the first to show that healthy elderly subjects with an excess of theta EEG activity not only are at risk of developing cognitive decline but already have a cognitive impairment
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