Coal feed component testing for CDIF

Investigations conducted during the conceptual design of the Montana MHD Component Development and Integration Facility (CDIF) identified commercially available processing and feeding equipment potentially suitable for use in a reference design. Tests on sub-scale units of this equipment indicated that they would perform as intended

Key dating features for timber-framed dwellings in Surrey

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Vernacular Architecture Group 2013. MORE OpenChoice articles are open access and distributed under the terms of the Creative Commons Attribution License 3.0.The main component of the Surrey Dendrochronology Project is the accurate dating of 177 ‘dwellings’, nearly all by tree-ring analysis. The dates are used to establish date ranges for 52 ‘key features’, which cover many aspects of timber-framing from building type to details of carpentry. It is shown that changes of method and fashion were in many cases surprisingly rapid, almost abrupt in historical terms. Previous dating criteria for timber-framed dwellings in the county have been refined and new criteria introduced. Clusters of change from the 1440s and the 1540s are shown and some possible historical links suggested.The Heritage Lottery Fund, the Domestic Buildings Research Group (Surrey), the Surrey Archaeological Society and the historical societies of Charlwood, Farnham and Nutfield

Pressure Induced Changes in the Antiferromagnetic Superconductor YbPd2Sn

Low temperature ac magnetic susceptibility measurements of the coexistent antiferromagnetic superconductor YbPd2Sn have been made in hydrostatic pressures < 74 kbar in moissanite anvil cells. The superconducting transition temperature is forced to T(SC) = 0 K at a pressure of 58 kbar. The initial suppression of the superconducting transition temperature is corroborated by lower hydrostatic pressure (p < 16 kbar) four point resisitivity measurements, made in a piston cylinder pressure cell. At ambient pressure, in a modest magnetic field of ~ 500 G, this compound displays reentrant superconducting behaviour. This reentrant superconductivity is suppressed to lower temperature and lower magnetic field as pressure is increased. The antiferromagnetic ordering temperature, which was measured at T(N) = 0.12 K at ambient pressure is enhanced, to reach T(N) = 0.58 K at p = 74 kbar. The reasons for the coexistence of superconductivity and antiferromagnetism is discussed in the light of these and previous findings. Also considered is why superconductivity on the border of long range magnetic order is so much rarer in Yb compounds than in Ce compounds. The presence of a new transition visible by ac magnetic susceptibility under pressure and in magnetic fields greater than 1.5 kG is suggested.Comment: 5 pages, 6 figure

A shrinking Compact Symmetric Object: J11584+2450?

We present multi-frequency multi-epoch Very Long Baseline Array (VLBA) observations of J11584+2450. These observations clearly show this source, previously classified as a core-jet, to be a compact symmetric object (CSO). Comparisons between these new data and data taken over the last 9 years shows the edge brightened hot spots retreating towards the core (and slightly to the west) at approximately 0.3c. Whether this motion is strictly apparent or actually physical in nature is discussed, as well as possible explanations, and what implications a physical contraction of J11584+2450 would have for current CSO models.Comment: 16 pages, 6 figures, 5 tables. Accepted for publication in Ap

Detection of the Ammonium Ion in Space

We report on the detection of a narrow feature at 262816.73 MHz towards Orion and the cold prestellar core B1-bS, that we attribute to the 1(0)-0(0) line of the deuterated Ammonium ion, NH3D+. The observations were performed with the IRAM 30m radio telescope. The carrier has to be a light molecular species as it is the only feature detected over 3.6 GHz of bandwidth. The hyperfine structure is not resolved indicating a very low value for the electric quadrupolar coupling constant of Nitrogen which is expected for NH3D+ as the electric field over the N nucleus is practically zero. Moreover, the feature is right at the predicted frequency for the 1(0)-0(0) transition of the Ammonium ion, 262817(6) MHz (3sigma), using rotational constants derived from new infrared data obtained in our laboratory in Madrid. The estimated column density is 1.1(0.2)e12 cm-2. Assuming a deuterium enhancement similar to that of NH2D, we derive N(NH4+) sim 2.6e13 cm-2, i.e., an abundance for Ammonium of a few 1e(-11).Comment: Accepted for publication in the Astrophysical Journal Letters 04 June 201