Cosmic ray density gradient and its dependence on the north-south asymmetry in solar activity

An analysis of the diurnal anisotropy on geomagnetically quiet days was performed using neutron monitor data at Deep River, Leeds, Rome and Tokyo, well distributed in latitude and longitude for the period 1964-79. The days were separated according to the polarity of IMF on that day. A significant difference in the amplitude and phase was found on towards and away polarity days, particularly during the years of high solar activity and large north-south asymmetry. These results (particularly time of maximum) on geomagnetically quiet days show some better relationship to the expected results as compared to the results obtained using all the days in a year

Detector calibration of the Indian cosmic ray experiment (IONS) in Space-Shuttle Spacelab-13

In the Indian cosmic ray experiment (IONS) in Spacelab-3 the intention is to study nuclei up to iron in low energy cosmic rays, using CR-39 (DOP) detectors. CR-39 (DOP) was exposed to He4, C12, O16, Ne20, Si28, Ar40, Cr52 and Fe56 accelerated beams from various accelerator facilities available around the world. Different beam energies and exposure angles were used. From these exposures, the charge resolution and energy resolution for the detector in the region of interest were studied. The effect of pre-annealing and depth on the response of our detector was studied. For isotopic resolution, exposed the detector samples were exposed to Ne2O and Ne22 accelerated beams. Samples of CR-39 (DOP) exposed to different accelerated heavy ions were kept in the detector module to take into account the effect of ambient conditions on detector response during the flight

Relative abundances of sub-iron to iron nuclei in low energy (50-250 MeV/N) cosmic rays as observed in the Skylab experiment

A Lexan polycarbonate detector exposed on the exterior of Skylab-3 for 73 days during a solar quiet period was used to study the relative abundances of calcium to nickel ions in low energy cosmic rays of 50 to 250 MeV/N. The method of charge identification is based on the measurement of conelength (L) and residual range (R) of these particles in various Lexan sheets. Since more than one cone (sometimes as many as five) is observed and is measured, the charge accuracy becomes precise and accurate. The ratio of (calcium to manganese) to (iron and cobalt) obtained at three energy intervals of 50 to 80, 80 to 150, 150 to 250 and 50 to 250 MeV/N are 7.6 plus or minus 3.8, 2.7 plus or minus 0.8, 1.4 plus or minus 0.6 and 3.3 plus or minus 0.7 respectively. These data thus indicate a large increase of this ratio with decreasing energy. The origin of this strong energy dependence is not understood at present

Transport and Magnetic Properties of FexVse2 (x = 0 - 0.33)

We present our results of the effect of Fe intercalation on the structural, transport and magnetic properties of 1T-VSe2. Intercalation of iron, suppresses the 110K charge density wave (CDW) transition of the 1T-VSe2. For the higher concentration of iron, formation of a new kind of first order transition at 160K takes place, which go on stronger for the 33% Fe intercalation. Thermopower of the FexVSe2 compounds (x = 0 - 0.33), however do not show any anomaly around the transition. The intercalation of Fe does not trigger any magnetism in the weak paramagnetic 1T-VSe2, and Fe is the low spin state of Fe3+.Comment: 7 pages, 8 figures, 2 table

Robust/Optimal Temperature Profile Control Using Neural Networks

An approximate dynamic programming (ADP) based neurocontroller is developed for a heat transfer application. Heat transfer problem for a fin in a car\u27\u27s electronic module is modeled as a nonlinear distributed parameter (infinite-dimensional) system by taking into account heat loss and generation due to conduction, convection and radiation. A low-order, finite-dimensional lumped parameter model for this problem is obtained by using Galerkin projection and basis functions designed through the `Proper Orthogonal Decomposition\u27\u27 technique (POD) and the `snap-shot\u27\u27 solutions. A suboptimal neurocontroller is obtained with a single-network-adaptivecritic (SNAC). Further contribution of this paper is to develop an online robust controller to account for unmodeled dynamics and parametric uncertainties. A weight update rule is presented that guarantees boundedness of the weights and eliminates the need for persistence of excitation (PE) condition to be satisfied. Since, the ADP and neural network based controllers are of fairly general structure, they appear to have the potential to be controller synthesis tools for nonlinear distributed parameter systems especially where it is difficult to obtain an accurate model