Time-Dependent Models for a decade of SN 1993J

A classical and a relativistic law of motion for a supernova remnant (SNR) are deduced assuming an inverse power law behavior for the density of the interstellar medium and applying the thin layer approximation. A third equation of motion is found in the framework of relativistic hydrodynamics with pressure, applying momentum conservation. These new formulas are calibrated against a decade of observations of \snr. The existing knowledge of the diffusive processes of ultrarelativistic electrons is reviewed in order to explain the behavior of the `U' shaped profile of intensity versus distance from the center of SN 1993J.Comment: 20 pages 19 figures, Accepted for pubblication in Astrophysics and Space Science 201

Moisture uptake characteristics of a pultruded fibre reinforced polymer flat sheet subjected to hot/wet aging

This paper studies the moisture uptake characteristics of a pultruded E-glass fibre reinforced (isophthalic polyester) polymer after long-term exposure to hot/wet conditions. Both fully exposed samples of varying aspect ratios and selectively exposed samples were immersed in distilled water at 25 °C, 40 °C, 60 °C and 80 °C for a period of 224 days. For the fully exposed condition, bulk and directional diffusion coefficient values were determined. A three-dimensional approach using Fickian theory was applied to approximate the principal direction diffusions at 60 °C by using mass changes from samples having different aspect ratios. This revealed that the diffusion coefficient in the longitudinal (pultrusion) direction to be an order of magnitude higher than in the transverse and through-thickness principal directions. Diffusion coefficients in the three principal directions have also been determined for the selectively exposed condition at 60 °C through the application of one-dimensional Fickian theory. It was found that the size and shape of the samples influences moisture uptake characteristics, and thereby the values determined for bulk and directional diffusion coefficients. Furthermore, the influence of exposure temperature on moisture uptake and mass loss with time was examined. Investigation of the water medium by means of electrical measurements suggested that decomposition of the polymeric composite initiates very early, even after the very first day of immersion. Comparison between the infrared signatures from the pultruded material and the water's residual substances revealed significant decomposition, and this behaviour is verified by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopic (EDS) analysis as well as the recorded mass loss after 224 days of aging

The experiences and perceptions of female breast cancer patients regarding weight management during and after treatment for oestrogen-receptor positive disease: a qualitative study

Background: Weight gain is commonly observed during and after breast cancer treatment and is associated with poorer survival outcomes, notably in women with oestrogen-receptor positive disease. The aim of this qualitative study was to investigate the experiences and perceptions of oestrogen-receptor positive (ER +) female breast cancer patients (BCPs) regarding weight management behaviours during and after treatment. Secondly, to gain insight into the experiences of healthcare professionals (HCPs) regarding the provision of weight management advice to patients undergoing treatment. Methods: Four focus groups involving 16 BCPs having a median (range) age of 51 (35–70 y) and three focus groups involving 21 HCPs aged 46 (29–62) were held at a university campus, local cancer support centre or clinical site. Data were analysed using Framework analysis. Results: Four overarching themes (and 10 subthemes) were identified: (1) Treatment; (2) Support for lifestyle behaviour change; (3) Information availability for BCPs; (4) Knowledge of current evidence amongst HCPs. The physical and psychological consequences of treatment influenced motivation for weight management amongst BCPs. Social support for health promoting behaviours was viewed as important but was conflicting, requiring context-specific considerations. BCPs said they would have welcomed access to credible information (guided by HCPs) about the potential detrimental health effects of excess body weight and weight gain, together with advice on weight management via healthy eating and physical activity. HCPs felt that they had insufficient knowledge of public health dietary and physical activity recommendations or evidence-based interventions to confidently offer such advice. HCPs expressed concern that raising weight management issues would exacerbate distress or invoke feelings of guilt amongst BCPs, and cited time pressures on patient consultations as additional barriers to providing weight management support. Conclusion: The study yielded novel insights into factors influencing weight management behaviours amongst overweight ER + BCPs. The results suggest that evidence-based information and support, which addresses key physical and psychological challenges to physical activity and dietary behaviours, offers the best route to sustainable weight management in this population