32,501 research outputs found
Simplified method introduces drift fields into cells
Drift fields are simply introduced into solar cells at low temperatures in short periods. This is done after their rectifying junctions and output contacts are applied
Methods of calculation of a friction coefficient: Application to the nanotubes
In this work we develop theoretical and numerical methods of calculation of a
dynamic friction coefficient. The theoretical method is based on an adiabatic
approximation which allows us to express the dynamic friction coefficient in
terms of the time integral of the autocorrelation function of the force between
both sliding objects. The motion of the objects and the autocorrelation
function can be numerically calculated by molecular-dynamics simulations. We
have successfully applied these methods to the evaluation of the dynamic
friction coefficient of the relative motion of two concentric carbon nanotubes.
The dynamic friction coefficient is shown to increase with the temperature.Comment: 4 pages, 6 figure
Analysis of radiation damage in silicon solar cells and annealing or compensation of damage by impurities Final report, 7 Jan. 1964 - 21 Apr. 1966
Radiation damage in silicon solar cells and annealing or compensation of damage by impuritie
Ethylene line emission from the North Pole of Jupiter
A significant enhancement in infrared emission from hydrocarbon constituents of Jupiter's stratosphere was observed at a north polar hot spot (60 degrees latitude, 180 degrees longitude). A unique probe of this phenomena is ethylene (C2H4), which has not been observed previously from the ground. The profile of the emission line from ethylene at 951.742 cm-1, measured near the north pole of Jupiter, was analyzed to determine the morphology of the enhancement, the increase in C2H4 abundance and local temperature, as well as possible information on the altitude (pressure regions) where the increased emission is formed. Measurements were made using infrared heterodyne spectroscopy at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii in December 1989. At 181 degrees longitude a very strong emission line was seen, which corresponds to a 13-fold increase in C2H4 abundance or a 115K increase in temperature in the upper stratosphere, compared to values outside the hot spot. The hot spot was found to be localized to approx. 10 degrees in longitude; the line shape (width) implied that the enhanced emission originated very high in the stratosphere
The motion of the freely falling chain tip
The dynamics of the tip of the falling chain is analyzed. Results of
laboratory experiments are presented and compared with results of numerical
simulations. Time dependences of the velocity and the acceleration of the chain
tip for a number of different initial conformations of the chain are
determined. A simple analytical model of the system is also considered.Comment: 29 pages, 13 figure
Critical frequency in nuclear chiral rotation
Within the cranked Skyrme-Hartree-Fock approach the self-consistent solutions
have been obtained for planar and chiral rotational bands in 132La. It turns
out that the chiral band cannot exist below some critical rotational frequency
which in the present case equals omega=0.6MeV. The appearance of the critical
frequency is explained in terms of a simple classical model of two gyroscopes
coupled to a triaxial rigid body.Comment: 4 RevTeX pages, 6 EPS figure
Third-order superintegrable systems separable in parabolic coordinates
In this paper, we investigate superintegrable systems which separate in
parabolic coordinates and admit a third-order integral of motion. We give the
corresponding determining equations and show that all such systems are
multi-separable and so admit two second-order integrals. The third-order
integral is their Lie or Poisson commutator. We discuss how this situation is
different from the Cartesian and polar cases where new potentials were
discovered which are not multi-separable and which are expressed in terms of
Painlev\'e transcendents or elliptic functions
Urban environmental health applications of remote sensing
An urban area was studied through the use of the inventory-by-surrogate method rather than by direct interpretation of photographic imagery. Prior uses of remote sensing in urban and public research are examined. The effects of crowding, poor housing conditions, air pollution, and street conditions on public health are considered. Color infrared photography was used to categorize land use features and the grid method was used in photo interpretation analysis. The incidence of shigella and salmonella, hepatitis, meningitis, tuberculosis, myocardial infarction and veneral disease were studied, together with mortality and morbidity rates. Sample census data were randomly collected and validated. The hypothesis that land use and residential quality are associated with and act as an influence upon health and physical well-being was studied and confirmed
Urban environmental health applications of remote sensing, summary report
Health and its association with the physical environment was studied based on the hypothesis that there is a relationship between the man-made physical environment and health status of a population. The statistical technique of regression analysis was employed to show the degree of association and aspects of physical environment which accounted for the greater variation in health status. Mortality, venereal disease, tuberculosis, hepatitis, meningitis, shigella/salmonella, hypertension and cardiac arrest/myocardial infarction were examined. The statistical techniques were used to measure association and variation, not necessarily cause and effect. Conclusions drawn show that the association still exists in the decade of the 1970's and that it can be successfully monitored with the methodology of remote sensing
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