3,895 research outputs found

    Probing Solar Convection

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    In the solar convection zone acoustic waves are scattered by turbulent sound speed fluctuations. In this paper the scattering of waves by convective cells is treated using Rytov's technique. Particular care is taken to include diffraction effects which are important especially for high-degree modes that are confined to the surface layers of the Sun. The scattering leads to damping of the waves and causes a phase shift. Damping manifests itself in the width of the spectral peak of p-mode eigenfrequencies. The contribution of scattering to the line widths is estimated and the sensitivity of the results on the assumed spectrum of the turbulence is studied. Finally the theoretical predictions are compared with recently measured line widths of high-degree modes.Comment: 26 pages, 7 figures, accepted by MNRA

    Plasmacytomas with more than one immunoglobulin kappa mRNA: implications for allelic exclusion.

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    Locus of control, attributions and impression management in the selection interview

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    Surprisingly little is known about the ways in which candidates create positive impressions during employment interviews. Three studies are presented which investigate how candidate and interviewer locus of control influence preferences for three categories of explanations proffered by candidates during graduate recruitment interviews. In Study 1, we asked 139 undergraduate students and 37 personnel managers to rate internal-controllable, internal-uncontrollable and externaluncontrollable candidate attributions for hypothetical past events according to the likelihood of each producing a positive impression during a selection interview. Students also completed Rotter's Locus of Control questionnaire and the Interview Behaviour Scales. Students and personnel managers rated internal-controllable attributions most likely to create a positive impression. However, students with an external LoC rated external-uncontrollable explanations and internal-controllable explanations as being equally likely to convey a positive impression. In Study 2 a group of 62 candidates applying for actual positions with a company completed the same attribution questionnaire prior to first-stage interviews. Interviewer ratings of candidate performance correlated positively with ratings of internal-controllable explanations (r =.36, p< .001). In Study 3, a sample of 103 experienced interviewers completed the attribution questionnaire and the WLOC. All interviewers rated internal-controllable attributions most likely to convey a positive impression of a candidate. However, locus of control mediated preference for candidate attributions such that ‘External’ interviewers rated external-uncontrollable attributions significantly more likely to convey a positive impression than ‘Internal’ interviewers. The implications of these findings for impression management and interview selection decisions are discussed

    Asteroseismic Theory of Rapidly Oscillating Ap Stars

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    This paper reviews some of the important advances made over the last decade concerning theory of roAp stars.Comment: 9 pages, 5 figure

    Nutritional intakes of highly trained adolescent swimmers before, during, and after a national lockdown in the COVID-19 pandemic

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    Strict lockdown measures were introduced in response to the COVID-19 pandemic, which caused mass disruption to adolescent swimmers’ daily routines. To measure how lockdown impacted nutritional practices in this cohort, three-day photograph food diaries were analysed at three time points: before (January), during (April), and after (September) the first UK lockdown. Thirteen swimmers (aged 15 ± 1 years) from a high-performance swimming club submitted satisfactory food diaries at all time points. During lockdown, lower amounts of energy (45.3 ± 9.8 vs. 31.1 ± 7.7 kcal∙kg BM∙day-1, p0.05), despite fewer training hours being completed (15.0 ± 1.4 vs. 19.1 ± 2.2 h∙week-1, p<0.001). These findings highlight the ability of adolescent swimmers to alter their nutrition based on their changing training circumstances when receiving sport nutrition support. However, some individuals displayed signs of suboptimal nutrition during lockdown that were not corrected once training resumed. This warrants future research to develop interactive education workshops that maintain focus and motivation towards optimal nutrition practices in isolated periods away from training

    Full-Scale Tests of a New Type NACA Nose-Slot Cowling

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    An extended experimental study has been made in regard to the various refinements in the design of engine cowlings as related to the propeller-nacelle unit as a whole, under conditions corresponding to take-off, climb, and normal flight. The tests were all conducted at full scale in the 20-foot wind tunnel. This report presents the results of a novel type of engine cowling, characterized by the fact that the exit opening discharging the cooling air is not, as usual, located behind the engine but at the foremost extremity or nose of the cowling. The efficiency is found to be high, owing to the fact that higher velocities may be used in the exit opening

    Rotation profiles of solar-like stars with magnetic fields

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    The aim of this work is to investigate rotation profile of solar-like stars with magnetic fields. A diffusion coefficient of magnetic angular momentum transport is deduced. Rotating stellar models with different mass are computed under the effect of the coefficient. Then rotation profiles are obtained from the theoretical stellar models. The total angular momentum of solar model with only hydrodynamic instabilities is about 13 times larger than that of the Sun at the age of the Sun, and this model can not reproduce quasi-solid rotation in the radiative region. However, not only can the solar model with magnetic fields reproduce an almost uniform rotation in the radiative region, but its total angular momentum is consistent with helioseismic result at the level of 3 σ\sigma at the age of the Sun. The rotation of solar-like stars with magnetic fields is almost uniform in the radiative region. But there is an obvious transition region of angular velocity between the convective core and the radiative region of models with 1.2 - 1.5 M⊙M_{\odot}, where angular velocity has a sharp radial change, which is different from the rotation profile of the Sun and massive stars with magnetic fields. Moreover the changes of the angular velocity in the transition region increase with the increasing in the age and mass.Comment: Accepted for publication in ChjA
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