104 research outputs found

    A Social Identity Approach to Sport Psychology: Principles, Practice, and Prospects.

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    Drawing on social identity theory and self-categorization theory, we outline an approach to sport psychology that understands groups not simply as features of sporting contexts but rather as elements that can be, and often are, incorporated into a person's sense of self and, through this, become powerful determinants of their sport-related behavior. The underpinnings of this social identity approach are outlined, and four key lessons for sport that are indicative of the analytical and practical power of the approach are presented. These suggest that social identity is the basis for sports group (1) behavior, (2) formation and development, (3) support and stress appraisal, and (4) leadership. Building on recent developments within sport science, we outline an agenda for future research by identifying a range of topics to which the social identity approach could fruitfully contribute

    Athlete brand construction: A perspective based on fans’ perceptions

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    Abstract The purpose of this study was to develop a framework for understanding the antecedents and components of athlete brand. Based on a set of 21 interviews conducted in three different countries, a detailed framework is proposed including five antecedents and two components of athlete brand. The antecedents are media (social media, mass media, video games and major sport events), oral communications (word of mouth, and rumors and narratives), impression management, social agents (parents, family members, friends and community), and teams and sport (sport interest, team interest and team geographical location). In turn, the components of athlete brand are related with on-field attributes (behavior, team, achievements, style of play and skills) and off-field attributes (physical attraction, lifestyle, personal appeal, ethnicity and entertainment). Complementarily, these components of athlete brand are proposed to have an impact on fans' loyalty towards the athlete. Implications of these findings for building and managing athlete brand are discussed, and directions for future studies are provided

    Structural and dynamic studies of Pr(11^{11}BH4_{4})3_{3}

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    Rare earth borohydrides RE (BH4)(3) are studied in the context of energy storage, lumines-cence and magnetic applications. We have investigated the structural behavior of pra-seodymium borohydride Pr ((BH4)-B-11)(3) containing B-11 isotope because of the previously reported negative thermal expansion. Differential scanning calorimetry (DSC), in-situ var-iable temperature synchrotron radiation powder X-ray diffraction (SR-PXD) and infrared studies reveal that Pr ((BH4)-B-11)(3) undergoes to a volume contraction during the phase tran-sition from alpha alpha-Pr ((BH4)-B-11)(3) to rhombohedral r-Pr ((BH4)-B-11)(3) phase upon heating to 493 K. Surprisingly, the phase transition persists upon cooling at room temperature. Vibrational analysis also shows that the stretching frequency of BH4-3; anion does not change upon heating which indicates that the B-H bond length remains constant during the structural phase transition from alpha-Pr ((BH4)-B-11)(3) to r-Pr ((BH4)-B-11)(3) phase. Additionally, the energy barrier of reorientation motion of the BH4- anion in the alpha-phase was estimated to be ca 23 kJ/mol by quasi-elastic neutron scattering (QENS) and Raman spectroscopy. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC

    Dynamics of porous and amorphous magnesium borohydride to understand solid state Mg-ion-conductors

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    Rechargeable solid-state magnesium batteries are considered for high energy density storage and usage in mobile applications as well as to store energy from intermittent energy sources, triggering intense research for suitable electrode and electrolyte materials. Recently, magnesium borohydride, Mg(BH4_{4})2_{2}, was found to be an effective precursor for solid-state Mg-ion conductors. During the mechanochemical synthesis of these Mg-ion conductors, amorphous Mg(BH4_{4})2_{2} is typically formed and it was postulated that this amorphous phase promotes the conductivity. Here, electrochemical impedance spectroscopy of as-received γ-Mg(BH4_{4})2_{2} and ball milled, amorphous Mg(BH4_{4})2_{2} confirmed that the conductivity of the latter is ~2 orders of magnitude higher than in as-received γ-Mg(BH4_{4})2_{2} at 353 K. Pair distribution function (PDF) analysis of the local structure shows striking similarities up to a length scale of 5.1 Å, suggesting similar conduction pathways in both the crystalline and amorphous sample. Up to 12.27 Å the PDF indicates that a 3D net of interpenetrating channels might still be present in the amorphous phase although less ordered compared to the as-received γ-phase. However, quasi elastic neutron scattering experiments (QENS) were used to study the rotational mobility of the [BH4_{4}] units, revealing a much larger fraction of activated [BH4_{4}] rotations in amorphous Mg(BH4_{4})2_{2}. These findings suggest that the conduction process in amorphous Mg(BH4_{4})2_{2} is supported by stronger rotational mobility, which is proposed to be the so-called “paddle-wheel” mechanism

    Lithium-ion (de)intercalation mechanism in core-shell layered Li(Ni,Co,Mn)O2 cathode materials

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    LiNix_{x}CoyMn1xy_{1-x-y}O2_{2} (NCM) intercalation compounds with core-shell architecture have been found to be promising cathode candidates for next-generation lithium-ion battery applications. The NCM cathodes\u27 functional properties are dependent on the transition metal relative ratios, making it a challenge to control the real structure of core-shell NCM cathode materials and to understand the synergistic effect of core and shell during the electrochemical cycling. Herein, a universal and facile synthetic strategy is developed to synthesize the NCM material composed of an inner Ni-rich core and a Mn-rich shell on a secondary particle level. Both the Ni-rich particle core and the Mn-rich outer surface possess a layered α–NaFeO2_{2}–type structure with the same space group (R3m). The in situ synchrotron-based X-ray diffraction and absorption spectroscopy results demonstrate that the two layered phases do not participate in the electrochemical reaction simultaneously during the first cycle between 2.7 and 4.3 V, while they exhibit a similar reversible (de)lithiation mechanism in the following cycles. These findings provide a new perspective for rational design of layered Ni-based cathode materials with high energy and long cycling life with particular two phase electrochemical characteristics

    Sport en criminaliteit

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    ARTIKELEN: R. Stokvis - Sport en corruptie B. Heere - Malversaties in de voetbalwereld; amateurisme, verdeeldheid en de schimmige transfermarkt J. de Boer - Scoren met kinderen; handel in jeugdige voetballers H.T. van Staveren - De juridische basis van het 'dopingverbod' in de sport W. Bos, H. de Doelder - Berechting van 'sportief' wangedrag; aspecten van straf- en tuchtrecht in de sport M. Theeboom - Vechtsporten; leren vechten of ... leren niet te vechten? SAMENVATTING: Met de toenemende verzakelijking van de sport komen steeds meer zaken aan het licht die moeilijk anders dan crimineel genoemd kunnen worden. Dit themanummer van Justitiële verkenningen werpt vanuit verschillende invalshoeken nader licht op de combinatie sport en criminaliteit

    Metal Hydrides and Related Materials - Energy Carriers for Novel Hydrogen and Electrochemical Storage

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    The seventh edition of the International Renewable and Sustainable Energy Conference (IRSEC) was held in Agadir (Sofitel Royal Bay, November 27–30, Morocco) under the Program Chair of Prof. Ahmed Ennaoui (IRESEN). IRSEC, as one of the biggest conferences in north Africa, aims at creating an international forum to facilitate discussions and exchanges in all aspects of renewable and sustainable energy. This Viewpoint will summarize the scientific presentations and stimulated discussions during the Special Session (November 28–29) on Metal Hydrides’ Energy covering topics of metal hydrides and energy related issues for innovative processes and technologies, with a focus on magnesium-based hydrides, intermetallic hydrides, complex and melt hydrides, porous materials, and thin films

    Identity crisis: A theoretical analysis of ‘team identification’ research.

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    Research question: Existing team identification research uses various definitions, conceptualisations, and theoretical frameworks. In this paper, we provide a theoretical analysis of previous research using the two dominant theoretical approaches: identity theory and the social identity approach. Our primary purpose is to provide a theoretical framework for the on-going study of ‘team’ identification in sport management research. Findings: Scholars have used identity theory (role) and the social identity approach (group) in their quest to understand team identification, however, limited attention has been paid to the differences between the two frameworks. We focus on two aspects of role and group identification that epitomize divergence in terms of analytical focus and explanations for behavior: the basis for identification and salience. Implications. The manuscript concludes with three recommendations for future research. First, with the aim of making future research more specific, we recommend the use of fan (spectator) identification in studies using identity theory and team identification (organisation / brand) in studies exploring the influence of group identity. Second, we outline definitions for role (fan) and group (team) identification in sport research. Finally, we reflect on the measurement of team identification

    Regional variation and determinants of vitamin D status in sunshine-abundant Thailand

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    <p>Abstract</p> <p>Background</p> <p>Vitamin D insufficiency is highly prevalent. Most of the studies concerning vitamin D status were generated from countries situated at temperate latitudes. It is less clear what the extent of vitamin D insufficiency is in countries situated in the tropics and how geographical regions within country would affect vitamin D status. In the present study, we investigated vitamin D status in Thais according to geographical regions and other risk factors.</p> <p>Methods</p> <p>Subjects consisted of 2,641 adults, aged 15 - 98 years, randomly selected from the Thai 4th National Health Examination Survey (2008-9) cohort. Serum 25 hydroxyvitamin D were measured by liquid chromatography/tandem mass spectrometry. Data were expressed as mean ± SE.</p> <p>Results</p> <p>Subjects residing in Bangkok, the capital city of Thailand, had lower 25(OH)D levels than other parts of the country (Bangkok, central, northern, northeastern and southern regions: 64.8 ± 0.7, 79.5 ± 1.1, 81.7 ± 1.2, 82.2 ± 0.8 and 78.3 ± 1.3 nmol/L, respectively; <it>p </it>< 0.001). Within each region, except for the northeastern part of the country, subjects living inside municipal areas had lower circulating 25(OH)D (central, 77.0 ± 20.9 nmol/L vs 85.0 ± 22.1 nmol/L, <it>p </it>< 0.001; north 79.3 ± 22.1 nmol/L vs 86.8 ± 21.8 nmol/L, <it>p </it>< 0.001; northeast 84.1 ± 23.3 nmol/L vs 87.3 ± 20.9 nmol/L, <it>p </it>= 0.001; south, 76.6 ± 20.5 nmol/L vs 85.2 ± 24.7 nmol/L, <it>p </it>< 0.001). Overall, the prevalence of vitamin D insufficiency was 64.6%, 46.7%, and 33.5% in Bangkok, municipal areas except Bangkok, and outside municipal area in other parts of the country, respectively. In addition, the prevalence of vitamin D insufficiency according to geographical regions was 43.1%, 39.1%, 34.2% and 43.8% in the central, north, northeast and south, respectively. After controlling for covariates in multiple linear regression analysis, the results showed that low serum 25(OH)D levels were associated with being female, younger age, living in urban and Bangkok.</p> <p>Conclusions</p> <p>Vitamin D insufficiency is common and varies across geographical regions in Thailand.</p
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