4,096 research outputs found
Calf feeding and management cow and calf management
"January, 1938, Reprinted, March 1940.""Prepared by T. A. Ewing, Extension Animal Husbandman, in collaboration with E. T. Itschner, State Club Agent."Appended to end, "Record blank for members in 4-H livestock clubs.
Sheep production : ewe and lamb management
Cooperative Extension Work in Agriculture and Home Economics, University of Missouri, College of Agriculture and the United States Department of Agriculture cooperating."December, 1937."Title from cover
Calf feeding and management cow and calf management
"January, 1938.""Prepared by T. A. Ewing, Extension Animal' Husbandman , in collaboration with E. T. Itschner, State Club Agent."Appended to end, "Record blank for members in 4-H livestock clubs."Cooperative Extension Work in Agriculture and Home Economics, University of Missouri, College of Agriculture and the United States Department of Agriculture cooperating.Title from cover
Discrete Symmetries in Covariant LQG
We study time-reversal and parity ---on the physical manifold and in internal
space--- in covariant loop gravity. We consider a minor modification of the
Holst action which makes it transform coherently under such transformations.
The classical theory is not affected but the quantum theory is slightly
different. In particular, the simplicity constraints are slightly modified and
this restricts orientation flips in a spinfoam to occur only across degenerate
regions, thus reducing the sources of potential divergences.Comment: 8 pages, v2: Minor change
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Continuity and Internal Properties of Gulf Coast Sandstones and their Implications for Geopressured Energy Development
The continuity of sandstone reservoirs is controlled by various factors including structural trend, sand-body geometry, and the distribution of framework grains, matrix, and interstices within the sand body. Except for the limits imposed by faults, these factors are largely inherited from the depositional environment and modified during sandstone compaction and cementation. Regional and local continuity of sandstone reservoirs depends on a depositional and structural hierarchy of four levels: (1) genetically related sandstones commonly associated with a single depositional system, (2) areally extensive fault blocks, (3) individual sandstones within a fault block, and (4) isolated reservoirs within a fault-bounded sandstone.
Compilation of published and unpublished data for Tertiary and late Quaternary Gulf Coast sandstones of fluvial, deltaic, barrier-strandplain, and submarine fan origins suggests that volumes of sand systems (first hierarchical level) range from 10^11 to 10^13 ft^3, whereas volumes of individual sand bodies range from 10^9 to 10^11 ft^3. The continuity and productive limits of the ancient sandstones are substantially reduced by faults and internal heterogeneity that further subdivide the sand body into individual compartments.
For the Wilcox and Frio trends of Texas, fault blocks (second hierarchical level) vary greatly in size, most being between 0.3 and 52 mi^2 in area; however, the distribution is strongly skewed toward small areas. Volumes of individual reservoirs (fourth hierarchical level) determined from engineering production data are 50 percent less to 200 percent more than estimates obtained from geologic mapping. In general, mapped volumes underestimate actual volumes where faults are non-sealing and overestimate actual volumes where laterally continuous shale breaks cause reductions in porosity and permeability.Bureau of Economic Geolog
Numerical Modeling of Ablation Heat Transfer
A unique numerical method has been developed for solving one-dimensional ablation heat transfer problems. This paper provides a comprehensive description of the method, along with detailed derivations of the governing equations. This methodology supports solutions for traditional ablation modeling including such effects as heat transfer, material decomposition, pyrolysis gas permeation and heat exchange, and thermochemical surface erosion. The numerical scheme utilizes a control-volume approach with a variable grid to account for surface movement. This method directly supports implementation of nontraditional models such as material swelling and mechanical erosion, extending capabilities for modeling complex ablation phenomena. Verifications of the numerical implementation are provided using analytical solutions, code comparisons, and the method of manufactured solutions. These verifications are used to demonstrate solution accuracy and proper error convergence rates. A simple demonstration of a mechanical erosion (spallation) model is also provided to illustrate the unique capabilities of the method
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Consolidation of Geologic Studies of Geopressured-Geothermal Resources in Texas
Detailed structural mapping at several horizons in selected study areas within the Frio growth-fault trend demonstrates a pronounced variability in structural style. At Sarita in South Texas, shale mobilization produced one or more shale ridges, one of which localized a low-angle growth fault trapping a wedge of deltaic sediments. At Corpus Christi, shale mobilization produced a series of large growth faults, shale-cored domed anticlines, and shale-withdrawal basins, which become progressively younger basinward. At Blessing, major growth faults trap sands of the Greta/Calhoun barrier system, having some discrete shale diapirs but little progradation. At Pleasant Bayou, a major early growth-fault system was overprinted by salt tectonics—the intrusion of Danbury Dome and the development of a salt-withdrawal basin. At Port Arthur, low-displacement, long-lived faults formed on a sand-poor shelf margin contemporaneously with broad salt uplifts and basins. Variability in styles can be related to the nature and extent of Frio sedimentation and shelf-margin progradation and to the presence of salt. Structural styles that are conducive to large geothermal reservoirs include blocks between widely spaced growth faults having dip reversal, salt-withdrawal basins, and shale-withdrawal basins. These styles are widespread on the Texas Gulf Coast. However, actually finding a large reservoir depends on demonstrating the existence of sufficient sand having adequate quality to support geopressured geothermal energy production.Bureau of Economic Geolog
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Consolidation of Geologic Studies of Geopressured-Geothermal Resources in Texas
Two major structural styles are identified in the Wilcox growth-fault trend of the Texas Gulf Coast. The style in central and southeast Texas is characterized by continuous, closely spaced growth faults that have little associated rollover despite moderate expansion of section and that show little flattening of the fault plane with depth. Where the growth-fault trend crosses the Houston Diapir Province, growth faults are localized by preexisting salt pillows; however, the piercement salt domes formed after the main phase of faulting, so the salt tectonics "overprints" the growth faults. In South Texas (south of Live Oak County), a narrow band of growth faults having high expansion and moderate rollover lies over and downdip of a ridge of deformed, overpressured shale and lies updip of a deep Tertiary-filled basin formed by withdrawal of overpressured shale. Significant antithetic faulting is associated with this band of growth faults. Also in South Texas, the lower Wilcox Lobo trend is deformed by highly listric normal faults beneath an unconformity that is probably related to Laramide tectonic activity. Wilcox sandstone reservoirs are predominantly of high-constructive deltaic (distributary-channel and delta-front) origin. This, together with close spacing of faults and characteristically low permeabilities, limits the size of geopressured reservoirs. The largest reservoirs may be in interfault areas or in salt- or shale-withdrawal basins.Bureau of Economic Geolog
Sediment Sorting and Rounding in a Basaltic Glacio-Fluvio-Aeolian Environment: hrisjkull Glacier, Iceland
Sediments and sedimentary rocks preserve a rich history of environment and climate. Identifying these signals requires an understanding of the physical and chemical processes that have affected sedimentary deposits [1]. Such processes include sorting and rounding during transport and chemical alteration through weathering and diagenesis. Although these processes have long been studied in quartz-dominated sedimentary systems [2], a lack of studies of basaltic sedimentary systems limits our interpretations of the environment and climate where mafic source rocks dominate, such as on Mars [3,4]. As part of the SAND-E: Semi-Autonomous Navigation for Detrital Environments project [5], which uses robotic operations to examine physical and chemical changes to sediments in basaltic glacio-fluvialaeolian environments, this research studies changes in sorting and rounding of fluvial-aeolian sediments along a glacier-proximal-to-glacier-distal transect in the outwash-plain of the risjkull glacier in SW Iceland (Fig. 1
Detailed study of dissipative quantum dynamics of K-2 attached to helium nanodroplets
We thoroughly investigate vibrational quantum dynamics of dimers attached to
He droplets motivated by recent measurements with K-2 [1]. For those
femtosecond pump-probe experiments, crucial observed features are not
reproduced by gas phase calculations but agreement is found using a description
based on dissipative quantum dynamics, as briefly shown in [2]. Here we present
a detailed study of the influence of possible effects induced by the droplet.
The helium droplet causes electronic decoherence, shifts of potential surfaces,
and relaxation of wave packets in attached dimers. Moreover, a realistic
description of (stochastic) desorption of dimers off the droplet needs to be
taken into account. Step by step we include and study the importance of these
effects in our full quantum calculation. This allows us to reproduce and
explain all major experimental findings. We find that desorption is fast and
occurs already within 2-10 ps after electronic excitation. A further finding is
that slow vibrational motion in the ground state can be considered
frictionless.Comment: 17 pages, 5 figure
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