2,642 research outputs found
Variational bounds on the energy dissipation rate in body-forced shear flow
A new variational problem for upper bounds on the rate of energy dissipation
in body-forced shear flows is formulated by including a balance parameter in
the derivation from the Navier-Stokes equations. The resulting min-max problem
is investigated computationally, producing new estimates that quantitatively
improve previously obtained rigorous bounds. The results are compared with data
from direct numerical simulations.Comment: 15 pages, 7 figure
Exponentially growing solutions in homogeneous Rayleigh-Benard convection
It is shown that homogeneous Rayleigh-Benard flow, i.e., Rayleigh-Benard
turbulence with periodic boundary conditions in all directions and a volume
forcing of the temperature field by a mean gradient, has a family of exact,
exponentially growing, separable solutions of the full non-linear system of
equations. These solutions are clearly manifest in numerical simulations above
a computable critical value of the Rayleigh number. In our numerical
simulations they are subject to secondary numerical noise and resolution
dependent instabilities that limit their growth to produce statistically steady
turbulent transport.Comment: 4 pages, 3 figures, to be published in Phys. Rev. E - rapid
communication
Internal Communication at a Liberal Arts College
The purpose for the policy manual is to inform all offices of the college of the administrative and management policies daily. These policies establish a method of communication for requests, coordination, approval, classification and issuance of standard operating procedures of the college.
Faculty, students and administration need guidelines for implementing objectives. The manual provides guidelines for implementing objectives . The manual provides guidelines for management policies and the functioning of the organization. More specifically, the manual is a means of determining how policy is reflected in the organizational structure and in the management practices.
The policy manual is a basic communication tool of executive action decision making and leadership
Construction and Evaluation of the Performance of a Horizontal Well in a Shallow, Thin Aquifer
Since infiltration galleries have been effective as a means of securing large quantities of water from thin aquifers, the question has arisen as to whether or not a small horizontal well that would yield sufficient water for irrigation could be constructed at a cost that would be within the budget of the family-sized farm in South Dakota. If so, a subsequent problem would be the development of some method of estimating the quantity of water a particular aquifer will yield to such a well. A possible approach would be to relate a certain length of horizontal casing to a vertical well of some particular diameter. If such a relationship can be found, the performance of such a well in another place could be predicted from data collected during a conventional pump test. This study will be confined to the details of the dragline construction of a pit, the placement of a horizontal well in a shallow thin aquifer; a, and an actual pump test to learn if a certain length of horizontal casing may be equivalent to a vertical well of some particular radius
Phase space dynamics of overdamped quantum systems
The phase space dynamics of dissipative quantum systems in strongly condensed
phase is considered. Based on the exact path integral approach it is shown that
the Wigner transform of the reduced density matrix obeys a time evolution
equation of Fokker-Planck type valid from high down to very low temperatures.
The effect of quantum fluctuations is discussed and the accuracy of these
findings is tested against exact data for a harmonic system.Comment: 7 pages, 2 figures, to appear in Euro. Phys. Let
Fuel quality/processing study. Volume 4: On site processing studies
Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded
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