64,331 research outputs found
Zinc Nutrition of Rice Plants as Influenced by Seed Germinated in Zinc Solutions
In recent years a physiological disorder of rice (Oryza sativa L.) seedlings growing in soils high in exchangeable calcium has been diagnosed as zinc deficiency. Calculations show that less than 30 g of zinc is needed to satisfy the nutrition of a hectare of 6-8-wk-old rice plants. Rice seed was soaked and germinated in dilute solutions of zinc ethylenediamine tetraacetate, zinc sulfate and zinc lignosulfonate prior to planting in greenhouse pots containing a zinc-deficient soil. The rice plants grown from the zinc-treated seed produced more growth and sorbed more zinc than rice plants grown from untreated seed
Projective-symmetric spaces
Cartanian symmetrical property of Riemannian projective-symmetric spaces - tensor geometr
An investigation of the optimization of parameters affecting the implementation of fourier transform spectroscopy at 20-500 micron from the C-141 airborne infrared observatory
A program for 20-500 micron spectroscopy from the NASA flying C141 infrared observatory is being carried out with a Michelson interferometer. The parameters affecting the performance of the instrument are studied and an optimal configuration for high performance on the C-141 aircraft is recommended. As each parameter is discussed the relative merits of the two modes of mirror motion (rapid scan or step and integrate) are presented
Hydrodynamics of internal solitons and a comparison of SIR-A and SIR-B data with ocean measurements
Large internal solitary waves have been observed by Shuttle SIR-A and SIR-B at locations in the Andaman Sea and the New York Bight. Satellite imagery and oceanographic measurements are used in conjunction with hydrodynamic interaction and electromagnetic scattering models to estimate the expected SAR image intensity modulations associated with the internal waves. There is reasonable agreement between the predicted and observed internal wave signatures
The addition of algebraic turbulence modeling to program LAURA
The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is modified to allow the calculation of turbulent flows. This is accomplished using the Cebeci-Smith and Baldwin-Lomax eddy-viscosity models in conjunction with the thin-layer Navier-Stokes options of the program. Turbulent calculations can be performed for both perfect-gas and equilibrium flows. However, a requirement of the models is that the flow be attached. It is seen that for slender bodies, adequate resolution of the boundary-layer gradients may require more cells in the normal direction than a laminar solution, even when grid stretching is employed. Results for axisymmetric and three-dimensional flows are presented. Comparison with experimental data and other numerical results reveal generally good agreement, except in the regions of detached flow
Steady-state attitude control propulsion systems computer program documentation and user's manual, volume 1
Computer program documentation and user manual for steady state attitude control propulsion system - vol.
Laser cooling in the Penning trap: an analytical model for cooling rates in the presence of an axializing field
Ions stored in Penning traps may have useful applications in the field of
quantum information processing. There are, however, difficulties associated
with the laser cooling of one of the radial motions of ions in these traps,
namely the magnetron motion. The application of a small radio-frequency
quadrupolar electric potential resonant with the sum of the two radial motional
frequencies has been shown to couple these motions and to lead to more
efficient laser cooling. We present an analytical model that enables us to
determine laser cooling rates in the presence of such an 'axializing' field. It
is found that this field leads to an averaging of the laser cooling rates for
the two motions and hence improves the overall laser cooling efficiency. The
model also predicts shifts in the motional frequencies due to the axializing
field that are in qualitative agreement with those measured in recent
experiments. It is possible to determine laser cooling rates experimentally by
studying the phase response of the cooled ions to a near resonant excitation
field. Using the model developed in this paper, we study the expected phase
response when an axializing field is present.Comment: 22 pages, 7 figure
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