10,249 research outputs found

    Complementary stereotyping of ethnic minorities predicts system justification in Poland

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    We investigate the phenomenon of complementary stereotyping of ethnic minorities in Poland and its relationship to system justification. Using results from a nationally representative survey we test the hypothesis that complementary stereotypes—according to which ethnic minorities are seen as possessing distinctive, offsetting strengths and weaknesses—would be associated with system justification among Polish majority citizens. For four minorities, results indicated that stereotyping them as (a) low in morality but high in competence or (b) high in morality but low in competence predicted greater system justification. These results suggest that even in a context that is low in support for the status quo, complementary stereotyping of ethnic minorities is linked to system justification processes. For the three minority groups that were lowest in social status, complementary stereotyping was unrelated to system justification. It appears that negative attitude towards these groups can be expressed openly, regardless of one’s degree of system justification

    Facilitators and barriers to contact between asylum seekers and their Dutch neighbors

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    Currently, Europe is dealing with a large number of asylum seekers. A recent report show that attitudes toward asylum seekers are not that negative in the Netherlands, and yet Dutch citizens living close to asylum seeker centers barely have contact with them. Because contact is vital for a multicultural society, we investigated the facilitators and barriers for Dutch citizens to establish and maintain contact with asylum seekers where they live close together. We conducted semistructured interviews with Dutch people and analyzed them using thematic analysis. We found four themes: Physical possibilities for Contact, Goals for Contact, Social Identities, and Positivity and Openness, and proposed a grounded theory model based on how the themes are related. The findings are discussed in relation to debates on multiculturalism and intergroup tolerance, and can be used to improve the integration policies by local governments, because they present clear conditions and practical information as to how contact can be established and maintained

    OPTIma:simplifying calorimetry for proton computed tomography in high proton flux environments

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    Objective. Proton computed tomography (pCT) offers a potential route to reducing range uncertainties for proton therapy treatment planning, however the current trend towards high current spot scanning treatment systems leads to high proton fluxes which are challenging for existing systems. Here we demonstrate a novel approach to energy reconstruction, referred to as ‘de-averaging’, which allows individual proton energies to be recovered using only a measurement of their integrated energy without the need for spatial information from the calorimeter. Approach. The method is evaluated in the context of the Optimising Proton Therapy through Imaging (OPTIma) system which uses a simple, relatively inexpensive, scintillator-based calorimeter that reports only the integrated energy deposited by all protons within a cyclotron period, alongside a silicon strip based tracking system capable of reconstructing individual protons in a high flux environment. GEANT4 simulations have been performed to examine the performance of such a system at a modern commercial cyclotron facility using a σ ≈ 10 mm beam for currents in the range 10–50 pA at the nozzle. Main results. Apart from low-density lung tissue, a discrepancy of less than 1% on the Relative Stopping Power is found for all other considered tissues when embedded within a 150 mm spherical Perspex phantom in the 10–30 pA current range, and for some tissues even up to 50 pA. Significance. By removing the need for the calorimeter system to provide spatial information, it is hoped that the de-averaging approach can facilitate clinically relevant, cost effective and less complex calorimeter systems for performing high current pCTs

    Ten myths about character, virtue and virtue education – plus three well-founded misgivings

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    Initiatives to cultivate character and virtue in moral education at school continue to provoke sceptical responses. Most of those echo familiar misgivings about the notions of character, virtue and education in virtue – as unclear, redundant, old-fashioned, religious, paternalistic, anti-democratic, conservative, individualistic, relative and situation dependent. I expose those misgivings as ‘myths’, while at the same time acknowledging three better-founded historical, methodological and practical concerns about the notions in question

    Acoustic characterisation of a small high-speed centrifugal compressor with casing treatment: an experimental study

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    [EN] With the advancements in manufacturing, materials and computational methods, turbomachinery designs have become more efficient providing higher specific power and reliability with lower weight and cost. The rotational speed of turbomachines has increased while the overall machine size has decreased for a similar power output leading to the pervasive presence of small, high-speed turbomachines, specifically centrifugal compressors in helicopters, unmanned aerial vehicles (UAVs), auxiliary power units (APUs), turbochargers and micro gas turbines. In addition to superior aerodynamic performance over a wide range, increased operating speeds have made the acoustic emissions of small centrifugal compressors a critical aspect of design. Therefore, this work presents an experimental campaign to characterise the acoustic behaviour of a compressor with an intent to quantify the dominant features of the flow-induced noise for design and near surge operating conditions. Furthermore, the campaign is extended to establish the impact of the ported shroud casing treatment and operating speed on the acoustic emission of the compressor. The in-duct noise measurement method is used in this work to quantify the noise generated in the compressor by measuring pressure fluctuations near the inducer and diffuser while the propagation of the generated noise to the ducts is computed from an array of piezoelectric sensors. Spectra at the design operating point are dominated by tonal noise while broadband noise content is the dominant feature of spectra for near surge operation. Although the ported shroud cavity does not significantly alter the overall noise levels of the compressor operating at design condition, it does seem to propagate tonal noise. For near surge operation, the casing treatment positively impacts the acoustic emission with a reduction of approximately 10 dB in the range up to the blade pass frequency. Furthermore, various broadband features are also observed to be alleviated by the casing treatment. (C) 2019 Elsevier Masson SAS. All rightsThe project was sponsored and supported by BorgWarner Turbo Systems and the Regional Growth Fund (RGF Grant Award 01.09.07.01/1789C). The authors would like to thank BorgWarner Turbo Systems for permission to publish the results presented in this paper.Sharma, S.; Broatch, A.; Garcia Tiscar, J.; Allport, JM.; Nickson, AK. (2019). Acoustic characterisation of a small high-speed centrifugal compressor with casing treatment: an experimental study. Aerospace Science and Technology. 95:1-15. https://doi.org/10.1016/j.ast.2019.1055181159

    Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions

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    [EN] The operation of compressor at lower mass flow rates is limited by surge which is marked by large fluctuations in operational variables and accompanied by significant increase in noise. Ported shroud casing treatment is a widely used method to control the flow near unstable conditions in order to obtain a stable operation and enhance deep surge margin. The research on the acoustic effects of the ported shroud design is limited. Therefore, this paper numerically characterises the acoustic features of a turbocharger compressor with ported shroud design operating at marginal or soft surge conditions and investigates the correlation between acoustic characteristics and the spatial flow structures. The acoustic and the flow field features are analysed using spectral signatures obtained from an experimentally validated numerical model using both performance and acoustic measurements. Propagation of the frequency content through the ducts has been estimated with the aid of the beamforming and method of characteristics to enhance the content coming from the compressor. Expected acoustic phenomena such as rotating order tones and blade passing peaks are correctly identified in the modelled spectrum with the limitation to capture the specific broadband features. Hence, the numerical model can be used to further the research encompassing the impact these flow enhancement solutions have on the noise emission of the turbocharger. Inspection of the flow field shows radially exiting fluid at the ported shroud slot leading to the formation of the high-speed jets exiting the ported shroud cavity. Circumferential propagation of the stall cells is also identified in the impeller. Further inspection of the pressure field through modal decomposition implies the localisation of the energetic noise sources in the impeller downstream components. The influence of the ported shroud cavity on the acoustic characteristic of the compressor is not significant and is limited to the propagation of the tonal noise in the direction of impeller upstream. (C) 2019 Elsevier Ltd. All rights reserved.The project is sponsored and supported by BorgWarner Turbo Systems and the Regional Growth Fund (RGF Grant Award 01.09.07.01/1789C). The authors would like to thank BorgWarner Turbo Systems for permission to publish the results presented in this paper. The support of the HPC group at the University of Huddersfield is gratefully acknowledged.Sharma, S.; Broatch, A.; Garcia Tiscar, J.; Nickson, AK.; Allport, JM. (2019). Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions. Applied Acoustics. 148:434-447. https://doi.org/10.1016/j.apacoust.2019.01.005S43444714

    Thrilled to have “bagged a bargain” or “bitter” and “very frustrating”? Exploring consumer attitudes to value and deals in tourism

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    Similar to most global tourism markets, UK consumers adjusted their behavior during the global financial crisis, emphasizing value for money in travel choices. However, there is little evidence concerning consumers’ value-seeking behavior and especially how deals, discounts, and other sales promotions influence tourist decision making. This project explores concepts of value consciousness and deal proneness to shed light on attitudes toward monetary value in travel purchases. Using focus groups, the study found that deals and discounts frequently underpin some tourist choices, but that value consciousness is related to deal proneness, and interactions between the two could result in negative, positive, or mixed emotions. This relationship was captured through a dynamic categorization of tourists’ attitudes and behavior into four approaches to deals and value, namely, deals (1) as a way of life, (2) as a bonus, (3) as a problem, and (4) as toxic. The categories were dynamic in that individuals could move across them. The implications for tourism marketers are outlined

    Consistent reactive participation of group members and reduction of intergroup conflict

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68015/2/10.1177_002200275900300103.pd
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