View-limiting shrouds for insolation radiometers

Insolation radiometers (normal incidence pyrheliometers) are used to measure the solar radiation incident on solar concentrators for calibrating thermal power generation measurements. The measured insolation value is dependent on the atmospheric transparency, solar elevation angle, circumsolar radiation, and radiometer field of view. The radiant energy entering the thermal receiver is dependent on the same factors. The insolation value and the receiver input will be proportional if the concentrator and the radiometer have similar fields of view. This report describes one practical method for matching the field of view of a radiometer to that of a solar concentrator. The concentrator field of view can be calculated by optical ray tracing methods and the field of view of a radiometer with a simple shroud can be calculated by using geometric equations. The parameters for the shroud can be adjusted to provide an acceptable match between the respective fields of view. Concentrator fields of view have been calculated for a family of paraboloidal concentrators and receiver apertures. The corresponding shroud parameters have also been determined

Microwave ISM Emission Observed by WMAP

We investigate the nature of the diffuse Galactic emission in the Wilkinson Microwave Anisotropy Probe (WMAP) temperature anisotropy data. Substantial dust-correlated emission is observed at all WMAP frequencies, far exceeding the expected thermal dust emission in the lowest frequency channels (23, 33, 41 GHz). The WMAP team (Bennett et al.) interpret this emission as dust-correlated synchrotron radiation, attributing the correlation to the natural association of relativistic electrons produced by SNae with massive star formation in dusty clouds, and deriving an upper limit of 5% on the contribution of Draine & Lazarian spinning dust at K-band (23 GHz). We pursue an alternative interpretation that much, perhaps most, of the dust-correlated emission at these frequencies is indeed spinning dust, and explore the spectral dependence on environment by considering a few specific objects as well as the full sky average. Models similar to Draine & Lazarian spinning dust provide a good fit to the full-sky data. The full-sky fit also requires a significant component with free-free spectrum uncorrelated with \Halpha, possibly hot (~million K) gas within 30 degrees of the Galactic center.Comment: ApJ in press (accepted 5 Dec 2003), version 2: corrected typos and added references. 23 pages, 5 figures, 2 tables. Free-free haze map is available at http://skymaps.inf

Microwave ISM Emission in the Green Bank Galactic Plane Survey: Evidence for Spinning Dust

We observe significant dust-correlated emission outside of H II regions in the Green Bank Galactic Plane Survey (-4 < b < 4 degrees) at 8.35 and 14.35 GHz. The rising spectral slope rules out synchrotron and free-free emission as majority constituents at 14 GHz, and the amplitude is at least 500 times higher than expected thermal dust emission. When combined with the Rhodes (2.326 GHz), and WMAP (23-94 GHz) data it is possible to fit dust-correlated emission at 2.3-94 GHz with only soft synchrotron, free-free, thermal dust, and an additional dust-correlated component similar to Draine & Lazarian spinning dust. The rising component generally dominates free-free and synchrotron for \nu >~ 14 GHz and is overwhelmed by thermal dust at \nu > 60 GHz. The current data fulfill most of the criteria laid out by Finkbeiner et al. (2002) for detection of spinning dust.Comment: ApJ in press. 26 pages, 11 figures, figures jpeg compressed to save spac

The Potential Constants of Ethane

The infrared and Raman data of light and heavy ethane (C2H6 and C2D6) have been reexamined for the purpose of determining as accurately as possible the potential constants of the ethane molecule. In order to fill in some of the gaps in the spectroscopic data, additional high resolution measurements have been made on the infrared spectrum of heavy ethane which have given more precise values for the active fundamental frequencies and zeta‐values. Resolution of the fine structure associated with the parallel band ν5* has given the value of the large moment of inertia of C2D6, thus completing the information required for the spectroscopic determination of the dimensions of ethane. The data yield, C☒C distance=1.543A, C☒H distance=1.102A, H☒C☒C angle=109°37′, and H☒C☒H angle=109°19′. The twenty‐two distinct potential constants compatible with the D3d symmetry of ethane have been determined through their relationships to the normal frequencies and zeta‐values of C2H6 and C2D6. The normal frequencies have been obtained by addition of anharmonic corrections to the spectroscopically observed fundamental frequencies. These corrections were estimated by means of the known anharmonic corrections for methane and the conditions imposed by the Teller product rule. The fundamental frequencies and zeta‐values have been taken directly from the observed band centers and rotational spacings wherever possible. In the cases of resonance, the influence of the couplings were either calculated or estimated and the corresponding unperturbed values for the frequencies and zeta‐values selected. The potential function is determined first in terms of a set of simple symmetry coordinates, and then reexpressed in terms of valence coordinates to permit comparison of the valence force constants of ethane and methane.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70194/2/JCPSA6-20-2-313-1.pd

Extending Access, Choice, and the Reign of the Market: Higher Education Reforms in British Columbia, 1989-2004

British Columbia has implemented two significant higher education reforms in the last 15 years. The first was an Access for All policy, and in particular, the creation of a new breed of institution—university colleges—and recognition of the right of colleges and institutes to confer "applied" degrees. The second reform, more recent and potentially with wider effect, is the decision to allow and, in fact, encourage the emergence of a private higher education sector to complement and to compete with the public sector. Although both reforms had the declared objective of enhancing accessibility and choice by expanding opportunities to study for degrees, the more recent one, now being implemented, had the further objective of opening higher education to market forces.La Colombie-Britannique a mis en oeuvre deux réformes principales de l'enseignement supérieur au cours des quinze dernières années. La première des deux, "Access for Ail," fut marquée par la création de nouvelles entités administratives dans la province que sont les collèges universitaires, et en même temps, l'octroi aux collèges communautaires et aux instituts d'études appliquées du droit de décerner des grades de 2e cycle. Une seconde réforme, plus récente et vraisemblablement plus significative au sens large, crée un secteur privé'd'enseignement post-secondaire, voué à la complémentarité vis-à-vis du public, mais franchement compétitif. Les deux réformes ont comme objectif un niveau d'accès accru au système, avec au surplus une plus grande disponibilité des programmes d'études. La deuxième cache pourtant un but à venir qui est de rendre l'enseignement supérieur beaucoup plus susceptible aux forces du marché libre

Processed meat consumption and Lung function: modification by antioxidants and smoking

This article has supplementary material available from www.erj.ersjournals.com: This study was supported by the Medical Research Council, UK. H. Okubo was supported in part by fellowship of the Astellas Foundation for Research on Metabolic Disorders, Japan and the Naito Memorial Grant for Research Abroad from the Naito Foundation, Japan

Primary Carcinoma of the Gallbladder

Carcinoma of the gallbladder is a relatively rare malignancy which is difficult to diagnose. The advent of improved imaging methods and the expansion of interventional radiology however, combined with advances in surgical technique, has produced a change in attitude towards this tumour. The available world literature since 1960 has been reviewed and is presented in this article. However, whilst the outlook for diagnosis and treatment is improving, clearly the association with cholelithiasis (between 45% and 100%), is a cause for concern particularly with the advent of treatments (lithotripsy, percutaneous gallstone extraction) which leave gall bladder mucosa and residual fragments of stone in situ

Analytical Tendex and Vortex Fields for Perturbative Black Hole Initial Data

Tendex and vortex fields, defined by the eigenvectors and eigenvalues of the electric and magnetic parts of the Weyl curvature tensor, form the basis of a recently developed approach to visualizing spacetime curvature. In particular, this method has been proposed as a tool for interpreting results from numerical binary black hole simulations, providing a deeper insight into the physical processes governing the merger of black holes and the emission of gravitational radiation. Here we apply this approach to approximate but analytical initial data for both single boosted and binary black holes. These perturbative data become exact in the limit of small boost or large binary separation. We hope that these calculations will provide additional insight into the properties of tendex and vortex fields, and will form a useful test for future numerical calculations.Comment: 18 pages, 8 figures, submitted to PR