A fully quantum mechanical calculation of the diffusivity of hydrogen in iron using the tight binding approximation and path integral theory

We present calculations of free energy barriers and diffusivities as functions of temperature for the diffusion of hydrogen in bcc-Fe. This is a fully quantum mechanical approach since the total energy landscape is computed using a new self consistent, transferable tight binding model for interstitial impurities in magnetic iron. Also the hydrogen nucleus is treated quantum mechanically and we compare here two approaches in the literature both based in the Feynman path integral formulation of statistical mechanics. We find that the quantum transition state theory which admits greater freedom for the proton to explore phase space gives result in better agreement with experiment than the alternative which is based on fixed centroid calculations of the free energy barrier. We also find results in better agreement compared to recent centroid molecular dynamics (CMD) calculations of the diffusivity which employed a classical interatomic potential rather than our quantum mechanical tight binding theory. In particular we find first that quantum effects persist to higher temperatures than previously thought, and conversely that the low temperature diffusivity is smaller than predicted in CMD calculations and larger than predicted by classical transition state theory. This will have impact on future modeling and simulation of hydrogen trapping and diffusion

Report of a study on the uptake and use of the 'Managing Change in the NHS' publications

Between December 2001 and March 2002, a team of independent researchers working in collaboration with and assisted by the NCCSDO carried out a telephone survey designed to gain feedback from the field about uptake, use and perceived impact of Organisational Change and Making Informed Decisions on Change. The study gathered a range of useful feedback and views about the two publications, highlighting the importance of evaluation in the process of commissioning research

Pigments of Imagination: An Actor\u27s Journey of Creating the Character of Jack Lawson from David Mamet\u27s Race

Abstract The purpose of this study is to create a believable, multiple dimension character portrayal of Jack Lawson in David Mamet’s Race. Documentation of the process will include: an explanation of the acting technique and analysis used to create the backstory and portrayal of the character; insight into the background and beliefs of playwright, David Mamet; and a personal review of my growth and performance

Dark Stars: Improved Models and First Pulsation Results

We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_{sun}. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with previous models, which assumed polytropic interiors. There are some differences in the details, with positive implications for observability. We found that, in the mass range of 10^4 -10^5 M_{sun}, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3 - 4, and more luminous by a factor of 2. Our models also confirm previous results, according to which supermassive DSs are very well approximated by (n=3)-polytropes. We also perform a first study of dark star pulsations. Our DS models have pulsation modes with timescales ranging from less than a day to more than two years in their rest frames, at z ~ 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.Comment: 17 pages; 11 figures; revised version; accepted by Ap

Self-Efficacy and Adventure Programs: Transferring Outcomes to Everyday Life

In the field of outdoor education, the be­lief that outdoor adventure programs have the ability to increase the participants\u27 self-efficacy has long been. used to defend program existence and to give more credi­bility to the discipline (Berman & Ber­man, 1994; Cockrell, 1991; Ewert, 1989; Miles & Priest, 1990). Although outdoor adventure programs are based on the as­sumption that a positive effect on indi­viduals\u27 self-efficacy will carry over into the participants\u27 lives after the course, there is little empirical research on this topic. In Hattie, Marsh, Neill, & Richards\u27 (1997) meta-analysis of research on adventure programs, they point out the need to study the development of self­-efficacy and to test specifically for efficacy (rather than self-concept in general or self-esteem). They suggest using alter­native research designs to enhance the standard pre-test, post-test design so commonly used in our field. In this paper, we address the theoretical and methodo­logical issues raised by Hattie et al. (1997), as well as the question of the transference of self-efficacy gained on an outdoor adventure course to individuals\u27 everyday lives. The paper reports on a study of self-efficacy in adult Outward Bound participants, and the level of trans­ference of self-efficacy gains to everyday life

Anatomical and biomechanical traits of broiler chickens across ontogeny. Part II. Body segment inertial properties and muscle architecture of the pelvic limb

In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogeny influence standing and moving. Here, to demonstrate these changes we quantify the segment inertial properties of the whole body, trunk (legs removed) and the right pelvic limb segments of five broilers at three different age groups across development. We also consider how muscle architecture (mass, fascicle length and other properties related to mechanics) changes for selected muscles of the pelvic limb. All broilers used had no observed lameness, but we document the limb pathologies identified post mortem, since these two factors do not always correlate, as shown here. The most common leg disorders, including bacterial chondronecrosis with osteomyelitis and rotational and angular deformities of the lower limb, were observed in chickens at all developmental stages. Whole limb morphology is not uniform relative to body size, with broilers obtaining large thighs and feet between four and six weeks of age. This implies that the energetic cost of swinging the limbs is markedly increased across this growth period, perhaps contributing to reduced activity levels. Hindlimb bone length does not change during this period, which may be advantageous for increased stability despite the increased energetic costs. Increased pectoral muscle growth appears to move the centre of mass cranio-dorsally in the last two weeks of growth. This has direct consequences for locomotion (potentially greater limb muscle stresses during standing and moving). Our study is the first to measure these changes in the musculoskeletal system across growth in chickens, and reveals how artificially selected changes of the morphology of the pectoral apparatus may cause deficits in locomotion