Thermal Behaviour of Euclidean Stars

A recent study of dissipative collapse considered a contracting sphere in which the areal and proper radii are equal throughout its evolution. The interior spacetime was matched to the exterior Vaidya spacetime which generated a temporal evolution equation at the boundary of the collapsing sphere. We present a solution of the boundary condition which allows the study of the gravitational and thermodynamical behaviour of this particular radiating model.Comment: 10 pages, 3 figure

Perceptions of performance feedback for an Incredible Years trained teacher : a thesis presented in partial fulfilment of the requirements for the degree of Master of Educational Psychology at Massey University, Albany, New Zealand

Material from Appendix A redacted due to copyright restrictions. Adapted from: Webster-Stratton, C. (2012). Incredible Years Teacher Classroom Management pyramid framework. Retrieved from http://www.incredibleyears.com/wp-content/uploads/800pxteaching-pyramid-good071213.jpgThe Incredible Years Teacher Classroom Management (IYTCM) programme, developed by Webster-Stratton, is delivered to New Zealand teachers as part of an initiative promoting positive behaviour in the education sector. The IYTCM incorporates evidence-based practices that have demonstrated effective and favourable outcomes for students and teachers. Teachers are able to create positive and nurturing learning environments through regular and accurate use of pro-active strategies and appropriate behaviour management practices. In turn, these environments can prevent and/or reduce adverse life outcomes for students. Performance feedback (PFB) was assessed as a support mechanism to enhance implementation of IYTCM command strategies. The use of a mixed methods design with an intervention trial, contributed to the exploration and establishment of value-oriented findings. By integrating methods, data and, analysis of qualitative and quantitative approaches, this research, (a) facilitated awareness for the teacher on their classroom management practices, (b) identified contextual factors that resulted in confounding effects on implementation; (c) underscored the teacher’s perceptions of credibility in relation to PFB consultants; and (d) considered the effects of the teacher’s perceived efficacy in classroom management. A concurrent examination of the findings produced insights into factors that may facilitate and/or hinder PFB, such as, attitudes toward practices, and degree of behavioural control. It was concluded that the combination of (i) teacher’s perceived efficacy; (ii) incongruence of IYTCM strategies with current practices; and (iii) poor knowledge to facilitate attitudinal change, may have impeded the teacher’s intentions to use IYTCM practices. The teacher’s perceptions and experiences present in this research have implications for the delivery and sustainability of classroom management practices, as well as efforts to ensure favourable outcomes for students

Nonlinear Shear-free Radiative Collapse

We study realistic models of relativistic radiating stars undergoing gravitational collapse which have vanishing Weyl tensor components. Previous investigations are generalised by retaining the inherent nonlinearity at the boundary. We transform the boundary condition to an Abel equation of the first kind. A variety of nonlinear solutions are generated all of which can be written explicitly. Several classes of infinite solutions exist.Comment: 13 pages, To appear in Math. Meth. Appl. Sc

Radiating Collapse with Vanishing Weyl stresses

In a recent approach in modelling a radiating relativistic star undergoing gravitational collapse the role of the Weyl stresses was emphasised. It is possible to generate a model which is physically reasonable by approximately solving the junction conditions at the boundary of the star. In this paper we demonstrate that it is possible to solve the Einstein field equations and the junction conditions exactly. This exact solution contains the Friedmann dust solution as a limiting case. We briefly consider the radiative transfer within the framework of extended irreversible thermodynamics and show that relaxational effects significantly alter the temperature profiles.Comment: 10 pages, submitted to IJMP-

The role of shear in dissipative gravitational collapse

In this paper we investigate the physics of a radiating star undergoing dissipative collapse in the form of a radial heat flux. Our treatment clearly demonstrates how the presence of shear affects the collapse process; we are in a position to contrast the physical features of the collapsing sphere in the presence of shear with the shear-free case. By employing a causal heat transport equation of the Maxwell-Cattaneo form we show that the shear leads to an enhancement of the core temperature thus emphasizing that relaxational effects cannot be ignored when the star leaves hydrostatic equilibrium.Comment: 15 pages, To appear in Int. J. Mod. Phys.