9,207 research outputs found
Computer program simulates design, test, and analysis phases of sensitivity experiments
Modular program with a small main program and several specialized subroutines provides a general purpose computer program to simulate the design, test and analysis phases of sensitivity experiments. This program allows a wide range of design-response function combinations and the addition, deletion, or modification of subroutines
Investigations into the harvesting ecology of the South African kelp Ecklonia maxima (Alariaceae, Laminariales)
Word processed copy.Includes bibliographical references.This present study examines several questions that were not addressed by previous studies of South African Ecklonia maxima beds. Firstly, this thesis examined the distribution of kelp biomass, at various sites around the Cape Peninsula and on the west coast, and at different depths within sites. An attempt was made to calculate a single figure that could be used in determining the biomass of kelp beds
Masterful Women: Slaveholding Widows From the American Revolution Through the Civil War
Prim and property Widows in control of land and slaves In the slave South, white masculinity entailed mastery, with its attendant privileges of patriarchal household dominance of dependent and submissive women and slaves, and its rights of democratic participation in the polit...
The Trial: The Assassination of President Lincoln and the Trial of the Conspirators
Extensive Anthology: Essays from the historical literature of slavery The emergence of the conceptual lens of the Atlantic World as a means of understanding New World slavery is one of the most significant recent scholarly developments in slavery studies. In this collection, Gad...
Accounting for Slavery: Masters and Management
If there is a central human character in Caitlin Rosenthal’s book about recordkeeping, accounting, and slavery, his name is Thomas Affleck. Born in Scotland, Affleck migrated to the United States in the 1830s. He eventually ended up in southwestern Mississippi, where he found the methods used by his fellow slaveholding cotton planters to manage and measure their operations irregular and inadequate for effectively gauging productivity over time. Drawing in part on his previous experience as a bookkeeper for the Bank of Scotland, Affleck crafted an accounting journal for his overseers to use, and in the late 1840s, he published the first edition of his Plantation Record and Account Book. Comprising a series of fifteen preprinted forms, the book let planters compile and track in one place everything from the number of people they enslaved and the amount of cotton each of those people picked every day, to tallies of capital costs and revenue from cotton sales. The recorded information could then be brought together on an annual balance sheet, allowing planters to account systematically for profit and loss, to review where they might be falling short, and to figure how they might squeeze more out of the laborers they held in bondage
Washington Brotherhood: Politics, Social Life, and the Coming of the Civil War
Reevaluating Washington\u27s Blundering Generation
One glance at opinion polls registering Congressional approval ratings in the single digits makes it plain that Americans today are both widely and deeply disgusted with the way politics and politicians operate in the nation’s capital. Acro...
The Lorentz Force and the Radiation Pressure of Light
In order to make plausible the idea that light exerts a pressure on matter,
some introductory physics texts consider the force exerted by an
electromagnetic wave on an electron. The argument as presented is both
mathematically incorrect and has several serious conceptual difficulties
without obvious resolution at the classical, yet alone introductory, level. We
discuss these difficulties and propose an alternate demonstration.Comment: More or less as in AJ
Two-dimensional hydrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic fluid flow through porous media
The behaviour of two dimensional binary and ternary amphiphilic fluids under
flow conditions is investigated using a hydrodynamic lattice gas model. After
the validation of the model in simple cases (Poiseuille flow, Darcy's law for
single component fluids), attention is focussed on the properties of binary
immiscible fluids in porous media. An extension of Darcy's law which explicitly
admits a viscous coupling between the fluids is verified, and evidence of
capillary effects are described. The influence of a third component, namely
surfactant, is studied in the same context. Invasion simulations have also been
performed. The effect of the applied force on the invasion process is reported.
As the forcing level increases, the invasion process becomes faster and the
residual oil saturation decreases. The introduction of surfactant in the
invading phase during imbibition produces new phenomena, including
emulsification and micellisation. At very low fluid forcing levels, this leads
to the production of a low-resistance gel, which then slows down the progress
of the invading fluid. At long times (beyond the water percolation threshold),
the concentration of remaining oil within the porous medium is lowered by the
action of surfactant, thus enhancing oil recovery. On the other hand, the
introduction of surfactant in the invading phase during drainage simulations
slows down the invasion process -- the invading fluid takes a more tortuous
path to invade the porous medium -- and reduces the oil recovery (the residual
oil saturation increases).Comment: 48 pages, 26 figures. Phys. Rev. E (in press
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