Elemental abundances for Nova LMC 1990#1

We present our analysis of the UV spectra of the fast ONeMg Nova LMC 1990#1. Observations with the IUE began on 1990 January 18 and continued through to 1990 March 15. We have analysed these spectra, and determined line fluxes and physical parameters as a function of time. Using both He  ii lines and the Balmer decrement, we find the reddening for the nova to be E ( B − V )≃0.22. Using the photoionization code cloudy 90.03b and the minimization routine minuit , we derive elemental abundances for the ejecta. We find the following abundances, relative to solar material: He=1, C=8, N=109, O=20, Ne=62, Mg=16, Al=257 and Si=41. These results are based on independent fits to different data sets acquired three weeks apart. These abundances are extremely similar to those found for V693 Corona Austrinae 1981. Given the position of V693 CrA in the Galaxy and the range of distances found for it, the similar abundances imply that the V693 CrA outburst took place on an older population white dwarf. The high N/O ratio implies an outburst on a massive white dwarf.     

THE COLONY METEORITE AND VARIATIONS IN CO3 CHONDRITE PROPERTIES

The Colony meteorite is an accretionary breccia containing several millimeter-to centimeter-size chondritic clasts embedded in a chondritic host. Colony is one of the least equilibrated CO3 chondrites; it has an unrecrystallized texture and contains compositionally heterogeneous olivine and low-Ca pyroxene, kamacite with low Ni and Co and high Cr, amoeboid inclusions with low FeO and MnO, a fine-grained silicate matrix with very high FeO, and numerous small chondrules with clear pink glass. However, Colony differs from normal CO chondrites in several respects: Although Al, Sc, V, Cr, Ir, Fe, Au and Ga abundances are consistent with a CO chondrite classification, certain lithophiles (Mg and Mn), siderophiles (Ni and Co) and chalcophiles (Se and Zn) are depleted by factors of 10–40%. The shape of Colony's thermoluminescence (TL) glow curve is similar to that of Allan Hills A77307 (another unequilibrated chondrite with CO3 petrological characteristics) and different from those of normal CO chondrites. [ALHA77307 also resembles Colony in having low Mg, Mn, Ni and Co, compared to normal CO chondrites, but it possesses CO-CV levels of Se and Zn and nearly CV levels of Cd.] Colony is badly weathered; it contains 22.7 wt.% Fe₂O₃ and 5.7 wt.% H₂O. Recalculating the analysis on an H₂O-free basis with all Fe₂O₃, NiO and CoO converted to metal, yields an inferred original metallic Fe, Ni abundance of ～ 19 wt.%. This is similar to that of Kainsaz (an unweathered CO3 fall), but much higher than that of all other CO3 chondrites (< 6.3 wt.%). Although it is possible that Colony and either ALHA77307 or Kainsaz constitute distinct CO3 chemical subgroups, the weathered nature of Colony and ALHA77307 preclude the drawing of firm conclusions. Nevertheless, it is clear that CO3 chondrites vary more in compositional and petrological properties than was previously recognized.     

Dynamics of buried pipes in abck filled trench

Dynamic response of pipelines lying in a back-filled trench in a semi-infinite medium is investigated. The pipelines are modelled as circular cylindrical shells of small thickness. The problems associated are the ones of plane strain, in which it is assumed that the waves are propagating perpendicular to the pipe-axes. Since no exact solution is obtainable for the problems considered here, a numerical teahnique that combines the finite element method with multipolar representation of the scattered field is used. Numerical results are presented for the normal displacements, as well as the hoop stress in the pipewall either in the presence or absence of another pipe lying nearby.     

Trace elements in fines from the Apollo 15 deep drill

No systematic variations in concentrations with depth were found for 1O trace elements in samples from the Apollo 15 deep drill. Presence of a significant amount of KREEP is indicated.     

The influence of morphology in determining the decomposition of two salt marsh macrophytes

Annual decomposition rates of Spartina alterniflora height forms and Juncus roemerianus were determined in situ in three North Carolina salt marshes using the litter bag method. The decomposition of Spartina was significantly influenced by size, i.e., height form, with the taller plants which had greater amounts of stem tissue, being more resistant to decay. Instantaneous decay rates for short and medium Spartina were not significantly different at any site, but they were both significantly greater than that of the tall form at two of the three study sites. Juncus decomposed more slowly than Spartina during the first 8 months, but had decomposed as completely as all three height forms of Spartina at two of the study sites by the end of the 13-month study period. Constant submergence appeared to inhibit decomposition since there was twice as much undecomposed plant material remaining in bags placed in tidal creeks as in those on the marsh surface.     

西藏中尼公路沿线的泥石流

中尼公路是西藏西南部经济发展的动脉，沿线泥石流灾害严重威胁到线路的正常运营，本研究根据航空照片和卫星图象解译结果，结合现场踏勘校对，深入地研究了沿线700km范围内的环境背景条件和泥石流活动规律，确定沿线有泥石流沟842条，其中沟谷型泥石流沟474条，在公路一侧直接危害公路的沟谷型泥石流241条，深入地探讨了这一高原特殊环境下的泥石流活动特性；为公路部门提供了泥石流防治方案，成为线路整治改建的依据。     

MICROSTRUCTURES OF SOME CHINESE ANTHRACITE

1. Previous works on microscopy of anthracite. The existing method of coal petrography seems to be well adaptableonly to bituminous or lignitic coals; in the case of anthracite,because of itsextreme opacity to light and resistency to most chemical solvent     

From public to private to … mutual? Restructuring water supply governance in England and Wales

A little over a decade after privatization, the water supply industry in England and Wales is undergoing a period of restructuring; many water companies have withdrawn from equity markets, some have separated asset ownership from operation and maintenance, and others have made proposals to return water supply infrastructure to public control through ‘mutuals’ or ‘customer corporations’. This paper situates the restructuring of the water industry within broader debates over ‘associative self-governance’ taking place in Britain. Underpinned by a conceptual framework drawing on insights from regulation theory, in which governance models are enacted through regulatory practice, the interrelationship between restructuring and re-regulation of the water supply industry is analyzed. The paper argues that the failure of the post-privatization regulatory model to contain the contradictions between stable returns and the efficiency imperative, on the one hand, and politically acceptable rates of return and the equity imperative, on the other, led to a re-regulation of the water supply industry, which was a key factor in restructuring. Restructuring has entailed multiple strategies (diversification, internationalization, vertical de-integration, mutualization, securitization), which are briefly analyzed. In contrast to analyses which depict restructuring as a ‘retreat of the market’, the analysis presented in this paper emphasizes the continuity of the commercial governance model applied in the water supply industry in 1989. In interpreting restructuring as an industry response to re-regulation of services provision, the paper interrogates the incentive structure underpinning current proposals for a ‘mutual’ future for public services in Britain.