ROSAT Observations of the Flare Star CC Eri

The flare/spotted spectroscopic binary star CC Eri was observed with the Position Sensitive Proportional Counter (PSPC) on the X-ray satellite ROSAT on 1990 July 9-11 and 1992 January 26-27. During the observations, the source was variable on time scales from a few minutes to several hours, with the X-ray (0.2-2 keV) luminosity in the range $\sim 2.5-6.8\times 10^{29} erg s^{-1}$. An X-ray flare-like event, which has a one hour characteristic rise time and a two hour decay time, was observed from CC Eri on 1990 July 10 16:14-21:34 (UT). The X-ray spectrum of the source can be described by current thermal plasma codes with two temperature components or with a continuous temperature distribution. The spectral results show that plasma at $Te\sim 10^{7}$ K exists in the corona of CC Eri. The variations in the observed source flux and spectra can be reproduced by a flare, adopting a magnetic reconnection model. Comparisons with an unheated model, late in the flare, suggest that the area and volume of the flare are substantially larger than in a solar two ribbon flare, while the electron pressure is similar. The emission measure and temperature of the non-flaring emission, interpreted as the average corona, lead to an electron pressure similar to that in a well-developed solar active region. Rotational modulation of a spot related active region requires an unphysically large X-ray flux in a concentrated area.Comment: 14 pages, compressed and uuencoded postscript file, to be published in MNRA

The letters of Charlotte Mary Yonge (1823-1901) edited by Charlotte Mitchell, Ellen Jordan and Helen Schinske.

Charlotte Yonge is one of the most influential and important of Victorian women writers; but study of her work has been handicapped by a tendency to patronise both her and her writing, by the vast number of her publications and by a shortage of information about her professional career. Scholars have had to depend mainly on the work of her first biographer, a loyal disciple, a situation which has long been felt to be unsatisfactory. We hope that this edition of her correspondence will provide for the first time a substantial foundation of facts for the study of her fiction, her historical and educational writing and her journalism, and help to illuminate her biography and also her significance in the cultural and religious history of the Victorian age

Synthesis of calculational methods for the design and analysis of radiation shields for nuclear rocket systems. Volume 5 - TIC-TOC-TOE, a FORTRAN program for the temperature in the coolant tank and other calculations and for the thermal neutron originating energy Final progress report

TIC-TOC-TOE computer program for radiation shielding design and analysis in nuclear rocket system

Uptake of nitrate and sulfate on dust aerosols during TRACE-P

Aerosol data collected near Asia on the DC-8 aircraft platform during TRACE-P has been examined for evidence of uptake of NO3− and SO4= on dust surfaces. Data is compared between a sector where dust was predominant and a sector where dust was less of an influence. Coincident with dust were higher mixing ratios of anthropogenic pollutants. HNO3, SO2, and CO were higher in the dust sector than the nondust sector by factors of 2.7, 6.2, and 1.5, respectively. The colocation of dust and pollution sources allowed for the uptake of NO3−and nss-SO4= on the coarse dust aerosols, increasing the mixing ratios of these particulates by factors of 5.7 and 2.6 on average. There was sufficient nss-SO4= to take up all of the NH4+present, with enough excess nss-SO4= to also react with dust CaCO3. This suggests that the enhanced NO3− was not in fine mode NH4NO3. Particulate NO3− (p-NO3−) constituted 54% of the total NO3− (t-NO3−) on average, reaching a maximum of 72% in the dust sector. In the nondust sector, p-NO3− contributed 37% to t-NO3−, likely due to the abundance of sea salts there. In two other sectors where the influence of dust and sea salt were minimal, p-NO3−accounted for \u3c15% of t-NO3−

A New Symmetric Expression of Weyl Ordering

For the creation operator \adag and the annihilation operator $a$ of a harmonic oscillator, we consider Weyl ordering expression of (\adag a)^n and obtain a new symmetric expression of Weyl ordering w.r.t. \adag a \equiv N and a\adag =N+1 where $N$ is the number operator. Moreover, we interpret intertwining formulas of various orderings in view of the difference theory. Then we find that the noncommutative parameter corresponds to the increment of the difference operator w.r.t. variable $N$. Therefore, quantum (noncommutative) calculations of harmonic oscillators are done by classical (commutative) ones of the number operator by using the difference theory. As a by-product, nontrivial relations including the Stirling number of the first kind are also obtained.Comment: 15 pages, Latex2e, the title before replacement is "Orderings of Operators in Quantum Physics", new proofs by using a difference operator added, some references added, to appear in Modern Physics Letters

Symmetries of pp-Waves with Distributional Profile

We generalize the classification of (non-vacuum) pp-waves \cite{JEK} based on the Killing-algebra of the space-time by admitting distribution-valued profile functions. Our approach is based on the analysis of the (infinite-dimensional) group of ``normal-form-preserving'' diffeomorphisms.Comment: 10 pages, latex2e, no figures, statement about the combination of symmetry classes of impulsive waves correcte

Distributional energy momentum tensor of the extended Kerr geometry

We generalize previous work on the energy-momentum tensor-distribution of the Kerr geometry by extending the manifold structure into the negative mass region. Since the extension of the flat part of the Kerr-Schild decomposition from one sheet to the double cover develops a singularity at the branch surface we have to take its non-smoothness into account. It is however possible to find a geometry within the generalized Kerr-Schild class that is in the Colombeau-sense associated to the maximally analytic Kerr-metric.Comment: 12 pages, latex2e, amslatex and epsf macro

Synthesis of calculational methods for design and analysis of radiation shields for nuclear rocket systems

Eight computer programs make up a nine volume synthesis containing two design methods for nuclear rocket radiation shields. The first design method is appropriate for parametric and preliminary studies, while the second accomplishes the verification of a final nuclear rocket reactor design

NFAT5 genes are part of the osmotic regulatory system in Atlantic salmon (Salmo salar)

Acknowledgements This study was supported by a grant from the Biotechnology and Biological Sciences Research Council (BBSRC, BB/H008063/1), UK to DGH and SAM. Funding also came from Research Council Norway for project number 241016 for DGH and EJ. This work was carried out as part of a PhD thesis funded by the Marine Alliance of Science and Technology Scotland (MASTS).Peer reviewedPublisher PD