128 research outputs found

    The relationship among personality, psychological athletic factors, and sports performance

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    This study aimed to explore the relationship among personality traits, psychological factors, such as self-efficacy, mental energy, and perfectionism, and the ability of college athletes to perform successfully as measured by their level of competition. Fifty-six NCAA Division I college athletes between 18 and 23 years old participated in the study. The questionnaire for this study included four different scales that measured personality traits, energy, individual and social self-efficacy, self-regulation, intrinsic motivation, and perfectionism levels of participants. The study examined the extent to which these psychological variables are important in determining the performance of college athletes. Results from the study revealed that athletes who played individual sports scored higher in openness compared to team sport athletes. Limitations and future research directions were discussed

    Observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304 with the MAGIC telescopes

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    The two BL Lac objects 1ES 1215+303 and 1ES 1218+304, separated by 0.8 deg, were observed with the MAGIC telescopes in 2010 and 2011. The 20 hours of data registered in January 2011 resulted in the first detection at Very High Energy (>100 GeV) of 1ES 1215+303 (also known as ON-325). This observation was triggered by a high optical state of the source reported by the Tuorla blazar monitoring program. Comparison with the 25 hours of data carried out from January to May 2010 suggests that 1ES 1215+303 was flaring also in VHE gamma-rays in 2011. In addition, the Swift ToO observations in X-rays showed that the flux was almost doubled respect to previous observations (December 2009). Instead, 1ES 1218+304 is a well known VHE gamma-ray emitter lying in the same field of view, which was then simultaneously observed with the MAGIC telescopes. The overall observation time of nearly 45 hours has permitted to measure the spectrum of this source with a much higher precision than previously reported by MAGIC. Here, we present the results of the MAGIC and the multi-wavelength observations of these two VHE gamma-ray emitting AGNs.Comment: 4 pages, 5 figures, Proceedings of the 32nd ICRC (2011) Beijin

    The X-ray variability of Seyfert 1.8/1.9 galaxies

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    Seyfert 1.8/1.9 are sources showing weak broad H-alpha components in their optical spectra. We aim at testing whether Seyfert 1.8/1.9 have similar properties at UV and X-ray wavelengths to Seyfert 2. We use the 15 Seyfert 1.8/1.9 in the Veron Cetty and Veron catalogue with public data available from the Chandra and/or XMM-Newton archives at different dates, with timescales between observations ranging from days to years. Our results are homogeneously compared with a previous work using the same methodology applied to a sample of Seyfert 2 (Hernandez-Garcia et al. 2015). X-ray variability is found in all 15 nuclei over the aforementioned ranges of timescales. The main variability pattern is related to intrinsic changes in the sources, which are observed in ten nuclei. Changes in the column density are also frequent, as they are observed in six nuclei, and variations at soft energies, possibly related to scattered nuclear emission, are detected in six sources. X-ray intraday variations are detected in six out of the eight studied sources. Variations at UV frequencies are detected in seven out of nine sources. A comparison between the samples of Seyfert 1.8/1.9 and 2 shows that, even if the main variability pattern is due to intrinsic changes of the sources in the two families, these nuclei exhibit different variability properties in the UV and X-ray domains. In particular, variations in the broad X-ray band on short time-scales (days/weeks), and variations in the soft X-rays and UV on long time-scales (months/years) are detected in Seyfert 1.8/1.9 but not in Seyfert 2. Overall, we suggest that optically classified Seyfert 1.8/1.9 should be kept separated from Seyfert 2 galaxies in UV/X-ray studies of the obscured AGN population because their intrinsic properties might be different.Comment: Accepted for publication in A&A. arXiv admin note: text overlap with arXiv:1505.0116

    Circumnuclear structure and kinematics in the active galaxy NGC 6951

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    A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B'IJK images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is evidence of two modes of star formation, in bursts and continuously. The equivalent width of the CaII triplet absorption lines show that, in the metal rich central region, the continuum is dominated by a population of red supergiants. The gaseous and stellar kinematics along three slit position angles, suggest the existence of a hierarchy of disks within disks, whose dynamics are decoupled at the two ILRs, that we find at 180 pc and at 1100 pc. This is supported by the structure seen in the high resolution HST images. The nucleus is spatially resolved within a radius of 1.5 arcsec, just inside the innermost ILR. Outside the iILR, the stellar CaT velocity profile is resolved into two components, associated with the bar and the disk. Several results indicate that this is a dynamically old system. It is thus possible that a nuclear bar has existed in NGC 6951 that drove the gas towards the nucleus, as in the bars within bars scenario, but that this bar has already dissolved by the gas accumulated within the circumnuclear region. We discuss the possibility that the kinematical component inside the iILR could be due to a nuclear outflow produced by the combined effects of SN and SN remnants, or to a nuclear disk, as in the disk within disk scenario that we propose for the fueling of the AGN in NGC 6951.Comment: 14 pages, 16 figures. Accepted for publication in Astronomy and Astrophysics. High resolution images in http://www.iaa.es/~eperez/research/degas.htm

    Ecology and diversity of mosquito larvae in ponds and lagoons of Northwestern Spain

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    Galicia, located in the northwestern part of Spain, has a great number and variety of aquatic ecosystems where mosquitoes can breed. Despite the sanitary relevance of these insects, studies on mosquito populations in the region are still scarce. The field research was carried out in 48 sampling points (27 continental lagoons, 12 coastal lagoons and 9 temporary ponds) throughout the entire Galician territory. The samples were collected intermittently and seasonally through different water quality monitoring projects between 2001 and 2017. More than 1500 mosquito larvae belonging to ten species of five genera (Aedes, Anopheles, Coquillettidia, Culex and Culiseta) were identified. Anopheles (Anopheles) maculipennis s.l. Meigen was the most widely distributed species in the study, being especially dominant in rural areas. In contrast, Culex (Culex) pipiens Linnaeus and Culex (Culex) theileri Theobald showed a preference for breeding in urban areas. New contributions to the knowledge about the larval ecology and distribution of these mosquito species are made throughout this study, including information about the tolerance of each species to water parameters (temperature, pH, dissolved oxygen and conductivity). Likewise, the relationship between culicid diversity and the habitat characteristics of the breeding sites (water body type, climate and level of anthropization) are discussed.Universidade de Vigo/CISUGXunta de Galici

    Regenerative tourism: A bibliometric analysis

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    Purpose: Despite regenerative tourism representing a beacon of hope to fight the problems faced by today's humankind, its multidisciplinary essence and fragmentation hinder the identification of major thematic areas for upcoming researchers. Therefore, the present study aims to systematically review the relevant literature on regenerative tourism. Methods: The literature was revised by adopting a bibliometric protocol. Web of Science and Scopus were employed to access pertinent publications, and Biblioshiny was used to track publication and source evolution and impact, main countries and affiliations' production, authors' relevance, productivity, collaborations, perform content, thematic, and co-citations analyses. Results: The literature on regenerative tourism has recently grown, fostered by rising interest due to the COVID-19 crisis. Attention in the field is still limited to a few main players, requiring an expansion in geographic and academic discipline terms. Thematic areas and their level of development were identified, assessing some relevant topics as fairly unexplored, especially concerning mindset change. Implications: This study offers inferences for future researchers and practitioners, employing literature summarizing, main sources and author identification, as well as gap detection, limiting its results to dual database record retrieval, as well as limited scope or search

    γ-Al2O3 as acid catalyst for dehydration of glucose to 5-hydroxymethylfurfural

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    Currently, the search and development of sustainable feedstocks for chemicals derived from petrol have gained worldwide attraction because of the instability of the price of crude oil, the reduction of fossil oil reserves, and the environmental concerns associated to the greenhouse effect caused by CO2 emissions, being biomass one of the world’s most important renewable carbon sources. The major component of plant-derived biomass are carbohydrates, being of great importance to develop efficient and green approaches to their valorization by conversion into high value-added products. Thus, glucose can be transformed by dehydration into 5-hydroxymethylfurfural (HMF), which is a versatile and key intermediate for the production of a wide variety of biobased chemicals and it is attracting much attention in biofuels and chemical industry. Different catalytic systems have been evaluated for HMF production from C6 carbohydrates as glucose, mostly based on heterogeneous catalysis as alternative to the use of liquid mineral acids. On the other hand, the high surface area, large pore size and thermal and hydrothermal stabilities of some mesoporous solids make them suitable for many catalytic processes. In the present work, the dehydration of glucose to HMF has been evaluated by using different mesoporous γ-Al2O3 with acid, neutral or basic character, in a biphasic water–MIBK solvent system to avoid the HMF degradation and its possible reaction with the intermediates from glucose to give soluble polymers and humins or acetalization with glucose. Different experimental parameters, such as reaction temperature and time, as well as the addition of inorganic salts have been studied in order to reach the maximum HMF yield.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministry of Economy and Competitiveness (CTQ2012-38204-C04-02 project), Junta de Andalucía (RNM-1565) and FEDER fund

    Valorization of carbohydrates: dehydration of sorbitol to isosorbide in the presence of acidic zeolites

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    Currently, the growing interest in the use of biomass as a renewable and sustainable raw material for the production of energy, chemicals and biofuels is driving the development of new catalytic processes and technologies for its conversion. In this context, the transformation of lignocellulosic biomass can lead to a variety of platform chemicals, with a broad spectrum of applications. Sorbitol is one of the useful biomass-derived chemicals that is obtained by catalytic hydrogenation of glucose, which subsequent dehydration and intramolecular cyclization in acid medium gives rise to the formation of isosorbide. This is a high value-added chemical widely used as intermediate in the pharmaceutical industry, additive polymers such as polyethylene terephthalate (PET) and production of biodegradable polymers. Mineral acids such as sulphuric and hydrochloric acids have efficient catalytic properties for dehydration of sorbitol. However, the well-known drawbacks associated to homogeneous catalysis have promoted the studies of heterogeneous catalytic processes. Thus, solid acid catalysts such as zeolites, tetravalent metal phosphates and sulfated copper oxide have been reported as alternative solid catalysts. Nevertheless, sometimes, drastic experimental conditions are required to reach a high catalytic activity. In the present work, different commercial zeolites, in their protonic form, have been evaluated as acid solid catalysts for sorbitol dehydration, and several experimental variables have been optimizedUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad (CTQ2012-38204-C04-02 project), Junta de Andalucía (RNM-1565) y Fondos FEDER de la U

    Mesoporous niobium oxide for dehydration of D-xylose into furfural

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    Se ha demostrado que el óxido de niobio mesoporoso es un catalizador eficaz para la deshidratación de D-xilosa a furfural, alcanzando una conversión del 92% y un rendimiento de furfural 49,3% a 170º C y 90 minutos. La lixiviación de Nb, determinada por ICP-MS, era inferior al 0,5% en peso de la concentración de Nb inicial, confirmando de este modo la estabilidad del catalizador ácido sólido.El furfural posee un gran potencial como molécula plataforma de origen renovable para la síntesis de una alta variedad de compuestos químicos. Se obtiene mediante la deshidratación de pentosas, principalmente a partir de D-xilosa, proceso catalizado por ácidos minerales en fase homogénea. Por tanto, dentro de la química verde y la búsqueda de sostenibilidad de los procesos catalíticos, es necesaria su sustitución por catalizadores sólidos ácidos que sean tolerantes al agua, ya que es el disolvente más utilizado para esta reacción. El óxido de niobio posee propiedades ácidas y es insoluble en agua, pero su superficie específica es muy baja. Por lo tanto, resulta muy interesante la síntesis de un óxido de niobio mesoporoso para emplearlo como catalizador en esta reacción. En este trabajo, se ha sintetizado un Nb2O5 mesoporoso y se ha evaluado su comportamiento catalítico en la obtención de furfural a partir de D-xilosa.Spanish Ministry of Science and Innovation (ENE2009-12743-C04-03 project)Junta de Andalucía (P09-FQM-5070).Ministry of Science and Innovation for the financial support under the Program Ramón y Cajal (RYC-2008-03387)
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