Tensor Anisotropies in an Open Universe

We calculate the anisotropies in the cosmic microwave background induced by long-wavelength primordial gravitational waves in a universe with negative spatial curvature, such as are produced in the ``open inflation'' scenario. The impact of these results on the COBE normalization of open models is discussed.Comment: 5pgs, 2 figs.; also avalable at http://www.sns.ias.edu/~whu, revision reflects ApJL published version, model dependence clarifie

HEALTHWATCH INVESTIGATIONS: Developing good practice

Investigating issues and concerns raised by service users, carers, patients and the wider public and getting feedback, is core business for local Healthwatch. This is an extremely challenging role. Local Healthwatch are small organisations who are charged with influencing large organisations and local health systems. In order to be successful local Healthwatch have to provide an analysis of the experiences of the public in a way that is credible and understandable to large organisations who will have much greater analytical and professional expertise and who may feel (rightly or wrongly) that they have a better grasp on what the challenges are and ‘what needs to be done’ than a local Healthwatch! This report summarises some of the thinking and practice that has emerged from work that has been led by Health Together1 and involved Healthwatch Leeds, Healthwatch Wakefield and other local Healthwatch in West Yorkshire - Bradford, Calderdale and Kirklees - as well as a briefing session facilitated by Involve Yorkshire and Humber which was attended by a further six Yorkshire and Humber Healthwatch

A First Map of the CMB at 0.5Deg Resolution

We use a Maximum Entropy technique to reconstruct a map of the microwave sky near the star Gamma Ursae Minoris, based on data from flights 2, 3 and 4 of the Millimeter-wave Anisotropy eXperiment (MAX).Comment: 5 pages plus 3 postscript figures, uuencoded compressed postscript, CfPA-94-TH-5

A new method to identify the optimal temperature of latent-heat thermal-energy storage systems for power generation from waste heat

The integration of thermal-energy storage (TES) within waste-heat recovery power generation systems has the potential to improve energy-efficiency in many industrial processes with variable and/or intermittent waste-heat streams. The first objective of this paper is to present a novel model of these systems that can be used at an early design stage to provide fast and accurate estimates of performance. More specifically, the method can identify the optimal temperature of latent-heat TES systems for waste-heat recovery applications based only on the known heat-source and heat-sink conditions (i.e., temperature, mass-flow rate and specificheat capacity), and can assess both single-stage and cascaded systems. The model has been validated against optimal organic Rankine cycle systems identified from a thermodynamic cycle optimisation. The second objective is to identify the characteristics of optimal systems for different heat-source profiles. The results indicate that, for a given application, there exists an optimal temperature for the latent-heat TES system that depends primarily on the relative size of the heat sink. Moreover, it is found that, for a heat engine operating with TES, the power rating ranges between 25% and 60% of the corresponding power rating for an optimal heat engine, operating without TES, that adapts instantaneously to heat-source fluctuations, whilst the total energy production is reduced by between 45% and 85% respectively. Finally, a small deviation is observed between the results obtained for the different heat sources considered, which suggests that these findings can be extrapolated to other heat sources not considered within this study

Quality factors of deformed dielectric cavities

An analysis is provided of the degradation that arises in the quality factor of a whispering gallery mode when a circular or spherical dielectric cavity is deformed. The large quality factors of such resonators are important to their use in applications such as sensors, wavelength filters or lasers. Yet a straightforward analysis of the effect of shape deformation on quality factors cannot given because the underlying complex ray data demanded by a standard eikonal approximation frequently does not exist. In this paper we exploit an approach that has been successfully used elsewhere to describe the strong directional emission of such systems, based on a perturbative treatment of the relevant complex ray families. Applicable when the radial perturbation is formally of the order of a wavelength, the resulting approximation successfully describes changes to the quality factor using the ray geometry in a neighbourhood of a discrete set of escaping rays guiding the directions of maximum emitted intensity.Comment: 16 pages, 4 figure

Energetics of Domain Walls in the 2D t-J model

Using the density matrix renormalization group, we calculate the energy of a domain wall in the 2D t-J model as a function of the linear hole density \rho_\ell, as well as the interaction energy between walls, for J/t=0.35. Based on these results, we conclude that the ground state always has domain walls for dopings 0 < x < 0.3. For x < 0.125, the system has (1,0) domain walls with \rho_\ell ~ 0.5, while for 0.125 < x < 0.17, the system has a possibly phase-separated mixture of walls with \rho_\ell ~ 0.5 and \rho_\ell =1. For x > 0.17, there are only walls with \rho_\ell =1. For \rho_\ell = 1, diagonal (1,1) domain walls have very nearly the same energy as (1,0) domain walls.Comment: Several minor changes. Four pages, four encapsulated figure

Energy Threshold for D+H_2→DH+H Reaction

We have been able to measure the threshold energy Eo for the reaction D+H_2→DH+H. The value obtained was (0.33±0.02) eV. Apparently, this is the first direct determination of a threshold energy for a reaction involving the formation and breaking of covalent bond