44,938 research outputs found
Singularity theorems based on trapped submanifolds of arbitrary co-dimension
Standard singularity theorems are proven in Lorentzian manifolds of arbitrary
dimension n if they contain closed trapped submanifolds of arbitrary
co-dimension. By using the mean curvature vector to characterize trapped
submanifolds, a unification of the several possibilities for the boundary
conditions in the traditional theorems and their generalization to arbitrary
co-dimension is achieved. The classical convergence conditions must be replaced
by a condition on sectional curvatures, or tidal forces, which reduces to the
former in the cases of co-dimension 1, 2 or n.Comment: 11 pages, no figures, some corrections
HOW MUCH DO FARMERS PAY IN TAXES?
A variety of federal, state, and local taxes are levied on farming operations in the United States. To date, there has been no attempt to systematically estimate what the total tax burden is on U.S. farms and how that burden varies from state to state. Based on the results of this analysis, the total farmer tax burden in 1994 was estimated at nearly $17 billion, most of which was in the form of real property tax (44%) and federal personal income tax (26%).farms, income taxes, property taxes, tax burdens, Agricultural Finance, Public Economics,
Inclusive deuteron-induced reactions and final neutron states
We present in this paper a formalism for deuteron-induced inclusive
reactions. We disentangle direct elastic breakup contributions from other
processes (which we generically call non-elastic breakup) implying a capture of
the neutron both above and below the neutron emission threshold. The reaction
is described as a two step process, namely the breakup of the deuteron followed
by the propagation of the neutron-target system driven by an optical potential.
The final state interaction between the neutron and the target can eventually
form an excited compound nucleus. Within this context, the direct neutron
transfer to a sharp bound state is a limiting case of the present formalism.Comment: To appear in the proceedings of the 14th International Conference on
Nuclear Reaction Mechanisms, Varenna, Ital
Afterburner Performance of Circular V-Gutters and a Sector of Parallel V-Gutters for a Range of Inlet Temperatures to 1255 K (1800 F)
Combustion tests of two V-gutter types were conducted in a 19.25-in. diameter duct using vitiated air. Fuel spraybars were mounted in line with the V-gutters. Combustor length was set by flame-quench water sprays which were part of a calorimeter for measuring combustion efficiency. Although the levels of performance of the parallel and circular array afterburners were different, the trends with geometry variations were consistent. Therefore, parallel arrays can be used for evaluating V-gutter geometry effects on combustion performance. For both arrays, the highest inlet temperature produced combustion efficiencies near 100 percent. A 5-in. spraybar - to - V-gutter spacing gave higher efficiency and better lean blowout performance than a spacing twice as large. Gutter durability was good
Experimental measurements of the laminar separation bubble on an Eppler 387 airfoil at low Reynolds numbers
An experimental investigation was conducted to measure the flow velocity in the boundary layer of an Eppler 387 airfoil. In particular, the laminar separation bubble that this airfoil exhibits at low Reynolds numbers was the focus. Single component laser Doppler velocimetry data were obtained at a Reynolds number of 100,000 at an angle of attack of 2.0 degree. Static Pressure and flow visualization data for the Eppler 387 airfoil were also obtained. The difficulty in obtaining accurate experimental measurements at low Reynolds numbers is addressed. Laser Doppler velocimetry boundary layer data for the NACA 663-018 airfoil at a Reynolds number of 160,000 and angle of attack of 12 degree is also presented
Report from a multidisciplinary meeting on anxiety as a non-motor manifestation of Parkinson’s disease
Alaska Supreme Court, Alaska Court of Appeals, U.S. District Court of Appeals for the Ninth Circuit, and U.S. District Court for the District of Alaska Year in Review
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