COCORP seismic investigations of the surrency bright spot beneath the southern Appalachians, USA

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

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An HREM study of superstructures in Ca4Al6SO16

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017846x ◽

1990 ◽

Vol 48 (4) ◽

pp. 1066-1067

Author(s):

Y.G. Wang ◽

H.Q. Ye ◽

K.H. Kuo

Keyword(s):

Calcium Aluminate ◽

Structural Model ◽

Bright Spot ◽

Sulphur Atom ◽

Synthetic Compound ◽

Space Group ◽

Lattice Images ◽

Cubic Structure ◽

Good Agreement

A synthetic compound Ca4Al6SO16 (usually abbreviated as C4A3S) obtained by mixing CaO, A12O3 and CaSO4 powders and finally sintered at 1380°C is a cement with excellent hydraulicity and greatly expanding in application. It is hydralysed rapidly by water to form predominatly calcium aluminate hydrates and therefore unlikly to occur naturally, although structurally it may be regarded as an end member of the sodalite-hauynite series of naturally occuring minerals. C4A3S has a cubic structure with ao=9.19Å and space group . Fig.1 is the projection viewed down axis, in which there are two sets of 8C position in , namely CaI and CaII, occupied by the calcium atoms, respectively, and the ratio of occupations in these two sets of positions is about 3:1. This suggests that the calcium atoms can freely occupy these sites in various degrees and usually they almost locates on the CaI positions. A through-focus series of the lattice images were found in good agreement with the simulated ones. Each bright spot in the image taken at Scherzer defocus correspounds to a colunm of sulphur atom in the structural model (Fig.1).

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Fuel consumption and fire characteristics during understory burning in a mixed white pine-hardwood stand in the Southern Appalachians.

10.2737/srs-rp-12 ◽

1998 ◽

Cited By ~ 8

Author(s):

Barton D. Clinton ◽

James M. Vose ◽

Wayne T. Swank ◽

Erik C. Berg ◽

David L. Loftis

Keyword(s):

Fuel Consumption ◽

Southern Appalachians ◽

White Pine ◽

Fire Characteristics

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Fuel consumption and fire characteristics during understory burning in a mixed white pine-hardwood stand in the Southern Appalachians.

10.2737/srs-rp-012 ◽

1998 ◽

Author(s):

Barton D. Clinton ◽

James M. Vose ◽

Wayne T. Swank ◽

Erik C. Berg ◽

David L. Loftis

Keyword(s):

Fuel Consumption ◽

Southern Appalachians ◽

White Pine ◽

Fire Characteristics

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A possible new hydrocarbon play, offshore central West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v180.5082 ◽

1998 ◽

pp. 28-30

Author(s):

Nina Skaarup ◽

James A. Chalmers

Keyword(s):

Seismic Data ◽

Mineral Resources ◽

Source Rocks ◽

Bright Spot ◽

Offshore Area ◽

West Greenland ◽

The Government ◽

Structural Closure ◽

Multichannel Seismic Data ◽

Seismic Lines

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Skaarup, N., & Chalmers, J. A. (1998). A possible new hydrocarbon play, offshore central West Greenland. Geology of Greenland Survey Bulletin, 180, 28-30. https://doi.org/10.34194/ggub.v180.5082 _______________ The discovery of extensive seeps of crude oil onshore central West Greenland (Christiansen et al. 1992, 1994, 1995, 1996, 1997, 1998, this volume; Christiansen 1993) means that the central West Greenland area is now prospective for hydrocarbons in its own right. Analysis of the oils (Bojesen-Koefoed et al. in press) shows that their source rocks are probably nearby and, because the oils are found within the Lower Tertiary basalts, the source rocks must be below the basalts. It is therefore possible that in the offshore area oil could have migrated through the basalts and be trapped in overlying sediments. In the offshore area to the west of Disko and Nuussuaq (Fig. 1), Whittaker (1995, 1996) interpreted a few multichannel seismic lines acquired in 1990, together with some seismic data acquired by industry in the 1970s. He described a number of large rotated fault-blocks containing structural closures at top basalt level that could indicate leads capable of trapping hydrocarbons. In order to investigate Whittaker’s (1995, 1996) interpretation, in 1995 the Geological Survey of Greenland acquired 1960 km new multichannel seismic data (Fig. 1) using funds provided by the Government of Greenland, Minerals Office (now Bureau of Minerals and Petroleum) and the Danish State through the Mineral Resources Administration for Greenland. The data were acquired using the Danish Naval vessel Thetis which had been adapted to accommodate seismic equipment. The data acquired in 1995 have been integrated with the older data and an interpretation has been carried out of the structure of the top basalt reflection. This work shows a fault pattern in general agreement with that of Whittaker (1995, 1996), although there are differences in detail. In particular the largest structural closure reported by Whittaker (1995) has not been confirmed. Furthermore, one of Whittaker’s (1995) smaller leads seems to be larger than he had interpreted and may be associated with a DHI (direct hydrocarbon indicator) in the form of a ‘bright spot’.

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