19,773 research outputs found
Stratigraphic Relationships of the Brentwood and Woolsey Members, Bloyd Formation (Type Morrowan), Northwest Arkansas
The Brentwood Member of the Bloyd Formation conformably overlies the Prairie Grove Member, Hale Formation in the type Morrowan succession of northwestern Arkansas. At its type locality, the Brentwood is separated from the underlying Prairie Grove Member by nearly 6 m of dark shale. Away from this area, the shale thins rapidly and the Hale-Bloyd boundary may be placed with difficulty. At some localities east of type section, the boundary is thought to be erosional rather than the more typical gradational contact. The Brentwood consists of discrete carbonate bodies separated by dark shales. The carbonates consist principally of open shelf deposits, such as crinozoan biosparites and oolites. All carbonate lithologies contain varying amounts of fine to medium grained, rounded, quartz sand. Regionally, the Brentwood Member becomes more shaly to the west of its type locality and loses the quartz sand content in its carbonate lithologies. To the east, the Brentwood shales become less prominent and quartz sandstone intervals characterize the succession. The Woolsey Member overlies the Brentwood Member and consists of light to dark, argillaceous shales with occasional sandstones, carbonates, and a thin coal. The coal is confined essentially to Washington and northern Crawford counties and never exceeds 45.7 cm. The shales are thought to be of terrestrial origin, but marine fossils and thin limestones in the lower part of typical Woolsey strata indicate a transitional change within the member rather than at its base. In contrast, the detrital fraction of the upper Brentwood carbonates seem to decrease rather than increase towards the Woolsey contact. To the west of the type area, the Woolsey gives rise to marine shales and carbonates. To the east, the Woolsey is equivalent to a thick, quartz pebble-bearing sandstone of fluvial origin. The top of the Woolsey Member is a regional unconformity with the overlying Dye Shale Member, Bloyd Formation
Multidimensional computer simulation of Stirling cycle engines
This report summarizes the activities performed under NASA-Grant NAG3-1097 during 1991. During that period, work centered on the following tasks: (1) to investigate more effective solvers for ALGAE; (2) to modify the plotting package for ALGAE; and (3) to validate ALGAE by simulating oscillating flow problems similar to those studied by Kurzweg and Ibrahim
A Solid State \u3csup\u3e13\u3c/sup\u3eC-NMR Study of Diamonds and Graphites
The 13C-NMR spectra of gem quality and industrial diamonds show two resonances with the more intense resonance at high field. Two resonances are also shown in 13C-NMR spectra of various graphites; however, the low field resonance is of greater intensity than the high field resonance in the graphites. The resonances are very broad and they are assigned to graphite type (sp2) carbon and diamond type (sp3) carbon
Recent developments in home equity lending
The equity that has accumulated in homes is one of the largest components of U.S. household wealth. In recent years, many homeowners have borrowed large amounts against that equity, frequently to finance new consumption expenditures or pay down outstanding consumer debt. In view of the growing importance of home equity credit in household finances, the Federal Reserve has for a number of years participated in nationwide surveys of the use of home equity loans. This article presents findings from a 1997 survey and from other sources of information on home equity lending.Home equity loans
Discussion of the potential and limitations of direct and large-eddy simulations
The full text of the discussion paper presented at the Whither Turbulence Workshop on the potential and limitations of direct and large-eddy simulations is provided. Particular emphasis is placed on discussing the role of numerics and mathematical theory in direct simulations of both compressible and incompressible flows. A variety of unresolved issues with large-eddy simulations such as their implementation in high-order finite difference codes, problems with defiltering, and modifications to accommodate integrations to solid boundaries are elaborated on. These as well as other points are discussed in detail along with the authors' views concerning the prospects for future research
Fluorescence and UV-VIS studies of quinone-induced protein modifications
Quinones are the metabolites of a class of chemicals known as polycyclic aromatic hydrocarbons. These chemicals have been found to be toxic in the environment, especially when interacting with certain proteins. In this study, we investigated the modification of Lysozyme and Ribonuclease A by a series of benzoquinones as well as few naphthoquinones. Fluorescence spectroscopy was used to measure the degree of modification of Lysozyme and Ribonuclease A when incubated with quinones at differing concentrations and for various times. All reactions, unless noted, were carried out in a phosphate buffer (pH=7.0) at 37°C to mimic physiological conditions. The fluorescence intensity of modified protein was shown to be less than that of unmodified protein, and effects of quinone substituents were examined. UV-VIS spectroscopy was also utilized to monitor adduct formation and other protein modifications. This study adds to our understanding of the effects of quinones on biological systems
Alien Registration- Ball, Thomas Charles A. (Camden, Knox County)
https://digitalmaine.com/alien_docs/15129/thumbnail.jp
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