Design procedure for low-drag subsonic airfoils

Airfoil has least amount of drag under given restrictions of boundary layer transition position, lift coefficient, thickness ratio, and Reynolds number based on airfoil chord. It is suitable for use as wing and propeller aircraft sections operating at subsonic speeds and for hydrofoil sections and blades for fans, compressors, turbines, and windmills

Elucidating the Correlation of the Quasar \ion{Fe}{2}/\ion{Mg}{2} Ratio with Redshift

Interpretation of the \ion{Fe}{2}(UV)/\ion{Mg}{2} emission ratios from quasars has a major cosmological motivation. Both Fe and Mg are produced by short-lived massive stars. In addition, Fe is produced by accreting white dwarf supernovae somewhat after star formation begins. Therefore, we expect that the Fe/Mg ratio will gradually decrease with redshift. We have used data from the Sloan Digital Sky Survey to explore the dependence of the \ion{Fe}{2}(UV)/\ion{Mg}{2} ratio on redshift and on luminosity in the redshift range of $0.75< z< 2.20$, and we have used predictions from our 830-level model for the \ion{Fe}{2} atom in photoionization calculations to interpret our findings. We have split the quasars into several groups based upon the value of their \ion{Fe}{2}(UV)/\ion{Mg}{2} emission ratios, and then checked to see how the fraction of quasars in each group varies with the increase of redshift. We next examined the luminosity dependence of the \ion{Fe}{2}(UV)/\ion{Mg}{2} ratio, and we found that beyond a threshold of \ion{Fe}{2}(UV)/\ion{Mg}{2} =~ 5, and $M_{2500} < -25\rm mag$, the \ion{Fe}{2}(UV)/\ion{Mg}{2} ratio increases with luminosity, as predicted by our model. We interpret our observed variation of the \ion{Fe}{2}(UV)/\ion{Mg}{2} ratio with redshift as a result of the correlation of redshift with luminosity in a magnitude limited quasar sample.Comment: ApJL accepte

Securitisation and/or Westernisation: dominant discourses of Australian values and the implications for teacher education

Debates concerning the nature, purpose and importance of Australian values have resurfaced in Australia following the election of the Liberal-led Coalition government in September 2013. Two dominant discourses on Australian values have emerged within recent government rhetoric and public policy, both of which have included a demand for changes to how Australian values are taught and encountered within Australian education and schooling. In our analysis we suggest that the two dominant discourses, one focusing on securitisation and one on westernisation, have to this point operated separately, but have both focused on narrow, fixed and forced understandings of Australian values. Exploring the key themes of these two discourses, some important issues for teacher educators are set out, including the need to mediate these discourses against research evidence which suggests the importance of holistic and co-operative pedagogical relationships based on trust and humility for effective values education. Though our analysis focuses on the Australian context, the arguments made are likely to be of interest elsewhere given current debates about national values in education across a range of jurisdictions

A case for cautious optimism? Active citizenship and the Australian Civics and Citizenship curriculum

In late 2013 a new curriculum for Civics and Citizenship education was published by the Australian Curriculum and Assessment Reporting Authority for use in Australian schools. In line with previous curricular initiatives concerning education for citizenship in Australia a key rationale behind the new subject is the education of “active citizens”. Research evidence over the last twenty-five years paints a mixed picture regarding the extent to which the translation of policy intent has been successfully implemented within Australian schools. Exploring the new subject of Civics and Citizenship in Australia in the context of previous initiatives and existing research evidence, we explore the contested and complex nature of active citizenship around three key issues – the scope and form of action that constitutes citizenship in one’s communities, how young people themselves conceptualize and experience participation, the potential that active citizenship opportunities are interpreted as being synonymous with the use of active teaching and learning methods. On this basis we argue that the new curriculum provides some optimism for those committed to education for citizenship in Australian schools, but that this optimism needs to be tempered with a degree of caution

The Stellar Populations of Low-redshift Clusters

We present some preliminary results from an on-going study of the evolution of stellar populations in rich clusters of galaxies. This sample contains core line-strength measurements from 183 galaxies with b_J <= 19.5 from four clusters with ~0.04. Using predictions from stellar population models to compare with our measured line strengths we can derive relative luminosity-weighted mean ages and metallicities for the stellar populations in each of our clusters. We also investigate the Mgb'-sigma and Hbeta_G'-sigma scaling relations. We find that, consistent with previous results, Mgb' is correlated with sigma, the likely explanation being that larger galaxies are better at retaining their heavier elements due to their larger potentials. Hbeta', on the other hand, we find to be anti-correlated with sigma. This result implies that the stellar populations in larger galaxies are older than in smaller galaxies.Comment: 3 pages, 2 figures, to appear in the Proceedings of IAU Colloquium 195: "Outskirts of Galaxy Clusters: intense life in the suburbs", Torino Italy, March 12-16 200

THE GLOBALIZATION OF SMALLER AGRI-FOOD FIRMS: CONCEPTS, FINDINGS AND PRESCRIPTIVE RECOMMENDATIONS

Agribusiness,

Stability of the Submillimeter Brightness of the Atmosphere Above Mauna Kea, Chajnantor and the South Pole

The summit of Mauna Kea in Hawaii, the area near Cerro Chajnantor in Chile, and the South Pole are sites of large millimeter or submillimeter wavelength telescopes. We have placed 860 GHz sky brightness monitors at all three sites and present a comparative study of the measured submillimeter brightness due to atmospheric thermal emission. We report the stability of that quantity at each site.Comment: 6 figure

A Variational Approach for Minimizing Lennard-Jones Energies

A variational method for computing conformational properties of molecules with Lennard-Jones potentials for the monomer-monomer interactions is presented. The approach is tailored to deal with angular degrees of freedom, {\it rotors}, and consists in the iterative solution of a set of deterministic equations with annealing in temperature. The singular short-distance behaviour of the Lennard-Jones potential is adiabatically switched on in order to obtain stable convergence. As testbeds for the approach two distinct ensembles of molecules are used, characterized by a roughly dense-packed ore a more elongated ground state. For the latter, problems are generated from natural frequencies of occurrence of amino acids and phenomenologically determined potential parameters; they seem to represent less disorder than was previously assumed in synthetic protein studies. For the dense-packed problems in particular, the variational algorithm clearly outperforms a gradient descent method in terms of minimal energies. Although it cannot compete with a careful simulating annealing algorithm, the variational approach requires only a tiny fraction of the computer time. Issues and results when applying the method to polyelectrolytes at a finite temperature are also briefly discussed.Comment: 14 pages, uuencoded compressed postscript fil