Subtleties in the quasi-classical calculation of Hawking radiation

he quasi-classical method of deriving Hawking radiation is investigated. In order to recover the original Hawking temperature one must take into account a previously ignored contribution coming from the temporal part of the action. This contribution plus a contribution coming from the spatial part of the action gives the correct temperature.Comment: 6 pages revtex. Honorable Mention in 2008 GRF essay contest, typos fixed, sign errors corrected. To be published in Special Issue of IJMP

Comparison between mirror Langmuir probe and gas puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer

Statistical properties of the scrape-off layer (SOL) plasma fluctuations are studied in ohmically heated plasmas in the Alcator C-Mod tokamak. For the first time, plasma fluctuations as well as parameters that describe the fluctuations are compared across measurements from a mirror Langmuir probe (MLP) and from gas-puff imaging (GPI) that sample the same plasma discharge. This comparison is complemented by an analysis of line emission time-series data, synthesized from the MLP electron density and temperature measurements. The fluctuations observed by the MLP and GPI typically display relative fluctuation amplitudes of order unity together with positively skewed and flattened probability density functions. Such data time series are well described by an established stochastic framework which model the data as a superposition of uncorrelated, two-sided exponential pulses. The most important parameter of the process is the intermittency parameter, {\gamma} = {\tau}d / {\tau}w where {\tau}d denotes the duration time of a single pulse and {\tau}w gives the average waiting time between consecutive pulses. Here we show, using a new deconvolution method, that these parameters can be consistently estimated from different statistics of the data. We also show that the statistical properties of the data sampled by the MLP and GPI diagnostic are very similar. Finally, a comparison of the GPI signal to the synthetic line-emission time series suggests that the measured emission intensity can not be explained solely by a simplified model which neglects neutral particle dynamics

Orbital Separation Amplification in Fragile Binaries with Evolved Components

The secular stellar mass-loss causes an amplification of the orbital separation in fragile, common proper motion, binary systems with separations of the order of 1000 A.U. In these systems, companions evolve as two independent coeval stars as they experience negligible mutual tidal interactions or mass transfer. We present models for how post-main sequence mass-loss statistically distorts the frequency distribution of separations in fragile binaries. These models demonstrate the expected increase in orbital seapration resulting from stellar mass-loss, as well as a perturbation of associated orbital parameters. Comparisons between our models and observations resulting from the Luyten survey of wide visual binaries, specifically those containing MS and white-dwarf pairs, demonstrate a good agreement between the calculated and the observed angular separation distribution functions

Kinetic treatment of parallel gradient nonuniformity for the ICRF heating—A fourier integral approach

We study the generally nonlocal Vlasov‐Maxwell wave propagation and absorption problem for an arbitrarily nonuniform plasma. The Fourier transform of the nonlocal dielectric response kernel, K(r,k), is constructed by integration along particle orbits in the nonuniform field. Although a finite Larmor radius expansion of the transverse particle motion still applies, the phase integrals which comprise the usual plasma dispersion function are altered, containing an additional parameter characterizing the parallel field gradient. The use of realistic phase decorrelation estimates over a single bounce orbit leads to a reduction of the phase integrals to a tractible form. We numerically solve a 1‐D sheared field version of the resultant integral equation describing the mode conversion physics. Significant changes are found for small k∥ values. In addition, local absorption in the resonance zone appears to be stratified in conjunction with the rf‐particle phase correlation which occurs for particles passing through the localized resonance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87459/2/350_1.pd

Alpha Particle Dynamics in Muon-Boosted Fusion Propulsion System

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77129/1/AIAA-2008-4674-768.pd

Supervision in healthcare: a critical review of the role, function and capacity for training

This paper examines the notion of clinical supervision and takes a close look at what it means from the perspective of both the supervisee and the supervisor, considering how it can be of benefit to the learner, the teacher and the patient. Clinical supervision has been shown to be vital for the development and consolidation of undergraduate and postgraduate education, while having a positive impact on patient outcomes and as such is a fundamental component in healthcare education. Central to supervision is achieving the best outcomes for the supervisee, and effective supervision ensures the development of confidence, professional identity, and the consolidation of therapeutic knowledge. Clinical supervision provides a platform for extending the supervisor-supervisee relationship beyond the student-teacher model to one of mutual personal development in contemporary knowledge and skills for clinical practice. Despite the perceived importance of clinical supervision for healthcare more broadly, there is evidence to suggest that few supervisors are adequately prepared with the theory and practice of clinical supervision to adequately fulfill the expectations that the role entails. It follows therefore, that in many cases, there is an expectation that the health professionals will supervise without adequate preparation. This paper, although not a panacea, may assist those who are supervising and who seek or require some guidance and support

Field Asymmetry and Thrust Control in the GDM Fusion Propulsion System

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76831/1/AIAA-2007-5612-220.pd