Undergraduate sports students’ perceptions of a change in learning pedagogy

This paper contributes to research in the scholarship of teaching by reporting on undergraduate sports students’ perceptions of their own learning when exposed to a Game Sense learning approach and reflections on my experience of teaching it. A multiple methods approach was utilised to gather data from a four-week “games” component of a 10-week unit of study with all participants (n = 20; aged 18-21) in their first year of a three-year sports-related undergraduate degree. The games classification system was used to plan session content over the four weeks with each week focusing on a different games classification. Data were organised and coded via inductive coding procedures with analysis conducted concurrently to identify three prominent themes: 1) positive experiences of competition and game play, 2) the range of cognitive and emotional learning opportunities provided by Game Sense pedagogy facilitated improved student engagement and learning, and 3) the challenge of effective teacher questioning to stimulate game play knowledge construction

Effects of cobalt in nickel-base superalloys

The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys

On How to Extend the NIR Tully-Fisher Relation to be Truly All-Sky

Dust extinction and stellar confusion by the Milky Way reduce the efficiency of detecting galaxies at low Galactic latitudes, creating the so-called Zone of Avoidance. This stands as a stumbling block in charting the distribution of galaxies and cosmic flow fields, and therewith our understanding of the local dynamics in the Universe (CMB dipole, convergence radius of bulk flows). For instance, ZoA galaxies are generally excluded from the whole-sky Tully-Fisher Surveys ($|b| \leq 5^\circ$) even if catalogued. We show here that by fine-tuning the near-infrared TF relation, there is no reason not to extend peculiar velocity surveys deeper into the ZoA. Accurate axial ratios ($b/a$) are crucial to both the TF sample selection and the resulting TF distances. We simulate the effect of dust extinction on the geometrical properties of galaxies. As expected, galaxies appear rounder with increasing obscuration level, even affecting existing TF samples. We derive correction models and demonstrate that we can reliably reproduce the intrinsic axial ratio from the observed value up to extinction level of about $A_J\simeq3$ mag ($A_V\sim11$ mag), we also recover a fair fraction of galaxies that otherwise would fall out of an uncorrected inclination limited galaxy sample. We present a re-calibration of the 2MTF relation in the NIR $J$, $H$, and $K_s$-bands for isophotal rather than total magnitudes, using their same calibration sample. Both TF relations exhibit similar scatter at high Galactic latitudes. However, the isophotal TF relation results in a significant improvement in the scatter for galaxies in the ZoA, and low surface brightness galaxies in general, because isophotal apertures are more robust in the face of significant stellar confusion.Comment: 12 pages, 10 figures, 4 tables, accepted for publication in MNRA

Galaxy peculiar velocities in the Zone of Avoidance

Dust extinction and stellar confusion of the Milky Way hinder the detection of galaxies at low Galactic latitude, creating the so-called Zone of Avoidance (ZoA). This has hampered our understanding of the local dynamics, cosmic flow fields and the origin of the Cosmic Microwave Background dipole. The ZoA ($|b| \le 5^\circ$) is also excluded from the "whole-sky" Two Micron All-Sky Survey (2MASS) Redshift Survey (2MRS) and 2MASS Tully-Fisher Survey (2MTF). The latter aims to provide distances and peculiar velocities for all bright inclined 2MASS galaxies with $K_s^o$ \leq 11\hbox{.\!\!^{\rm m}}25. Correspondingly, knowledge about the density distribution in the ZoA remains limited to statistical interpolations. To improve on this bias we pursued two different surveys to fill in the southern and northern ZoA. These data will allow a direct measurement of galaxy peculiar velocities. In this paper we will present a newly derived optimized Tully-Fisher (TF) relation that allow accurate measures of galaxy distances and peculiar velocities for dust-obscured galaxies. We discuss further corrections for magnitudes and biases and present some preliminary results on flow fields in the southern ZoA.Comment: 6 pages, 3 figures, to appear in Proceedings of SAIP2013, the 58th Annual Conference of the South African Institute of Physics, edited by Roelf Botha and Thulani Jili (SAIP and University of Zululand, 2014). ISBN: 978-0-620-62819-

How Barred is the NIR Nearby Universe? An analysis using 2MASS

We determine a firm lower limit to the bar fraction of 0.58 in the nearby universe using J+H+Ks-band images for 134 spirals from 2MASS. With a mean deprojected semi-major axis of 5.1 kpc, and a mean deprojected ellipticity of 0.45 this local bar sample lays the ground work for studies on bar formation and evolution at high redshift.Comment: In the proceedings "Penetrating Bars through Masks of Cosmic Dust: The Hubble Tuning Fork strikes a New Note

Oil Price Volatility, Financial Institutions and Economic Growth

Theory attributes finance with the ability to both promote growth and reduce output volatility. But evidence is mixed in both regards, partly due to endogeneity effects. For example, financial institutions themselves might be a source of volatility, as the events of 2008 suggest. We address this endogeneity issue by using oil price volatility as a source of exogenous volatility, to study the effect of finance. To do this, we use two empirical methodologies. First, we develop a quasi-natural experiment by studying the dramatic decline of oil prices in 2014 and beyond, using a synthetic control methodology. Our hypothesis is that the ability of oil-rich countries to mitigate the effects of this decline rested on the quality of their financial institutions. We focus on 11 oil-rich countries between 1980 and 2014 that had “poor” measures of financial development (treatment group) out of 20 such countries and synthetically create counterfactuals from the remaining (control) group with “superior” financial development. We subject both to the oil price shock of 2014. We find evidence that better financial institutions do indeed reduce output volatility and mitigate its negative effect on growth in the year that showed a sustained decline of the oil price. To address any remaining potential endogeneity between oil prices and finance, we further examine our findings by using a Panel CS-ARDL approach with 30 oil producing countries in our sample (and data over the period 1980-2016), illustrating that the effect of oil price volatility on growth is mitigated with better financial institutions. Our results make a strong case for the support of the positive role of financial development in growth and development