Global large scale structures in the F region

Measurements of neutral densities, temperatures and ion density and temperature by the Atmosphere Explorer C and E satellites exhibit fluctuations made up of coherent waves of scale size from hundreds to thousands of kilometers. The fluctuations in the AE-C data are found at times of low magnetic activity to extend from the auroral region in one hemisphere across the equator to the corresponding region in the other hemisphere with little change in apparent wavelength. The fluctuations in the AE-E data similarly exhibit at times of low magnetic activity nearly uniform wave structure encircling the equatorial belt. Typical examples of waves of more than 1000 km apparent wavelength in both the AE-C and AE-E data are presented. These observations during quiet times may be explained by a system of quasi-stationary waves excited by the auroral belts that are distributed about the Earth possibly with tidal or sub-tidal periods and scale lengths determined by the structure of the belts. According to this interpretation, Traveling Ionospheric Disturbance (TID's) are manifestations of transient wave systems moving past a ground observatory that result from changes in magnetic activity with periods and scale sizes associated with the regions of enhanced auroral activity. Some evidence suggesting tidal-like stationary waves from the Millstone Hill incoherent scatter radar is presented

Development and fabrication of advanced battery energy storage system Mid-term report, 27 Sep. 1966 - 26 Mar. 1967

Silver-cadmium secondary battery energy storage system using vented cells for manned orbital spacecraf

Experimental and Theoretical Search for a Phase Transition in Nuclear Fragmentation

Phase transitions of small isolated systems are signaled by the shape of the caloric equation of state e^*(T), the relationship between the excitation energy per nucleon e^* and temperature. In this work we compare the experimentally deduced e^*(T) to the theoretical predictions. The experimentally accessible temperature was extracted from evaporation spectra from incomplete fusion reactions leading to residue nuclei. The experimental e^*(T) dependence exhibits the characteristic S-shape at e^* = 2-3 MeV/A. Such behavior is expected for a finite system at a phase transition. The observed dependence agrees with predictions of the MMMC-model, which simulates the total accessible phase-space of fragmentation

Ambiguities in statistical calculations of nuclear fragmentation

The concept of freeze out volume used in many statistical approaches for disassembly of hot nuclei leads to ambiguities. The fragmentation pattern and the momentum distribution (temperature) of the emanated fragments are determined by the phase space at the freeze-out volume where the interaction among the fragments is supposedly frozen out. However, to get coherence with the experimental momentum distribution of the charged particles, one introduces Coulomb acceleration beyond this freeze-out. To be consistent, we investigate the effect of the attractive nuclear force beyond this volume and find that the possible recombination of the fragments alters the physical observables significantly casting doubt on the consistency of the statistical model.Comment: 11 pages+3 figure

Investigation of traveling ionospheric disturbances using the differential Doppler data from the Apollo-Soyuz mission

The ASTP Doppler data were recalibrated, analyzed and related to geophysical phenomena and found consistent. Spectra were computed for data intervals covering each hemisphere. As many as 14 such intervals were analyzed. Wave structure is seen in much of the data. The spectra for all those intervals are very similar in a number of respects. They all decrease with frequency, or with decreasing wavelength. Power law fits are reasonable and spectral indices are found to range from about -2.0 to about -3.5. Both large scale (thousands of kilometers) and medium scale (hundreds of kilometers) waves are evident. These spectra are very similar to spectra of in situ measurements of neutrals and ionization measured by Atmosphere Explorer C

Statistical mechanics of non-hamiltonian systems: Traffic flow

Statistical mechanics of a small system of cars on a single-lane road is developed. The system is not characterized by a Hamiltonian but by a conditional probability of a velocity of a car for the given velocity and distance of the car ahead. Distribution of car velocities for various densities of a group of cars are derived as well as probabilities of density fluctuations of the group for different velocities. For high braking abilities of cars free-flow and congested phases are found. Platoons of cars are formed for system of cars with inefficient brakes. A first order phase transition between free-flow and congested phase is suggested.Comment: 12 pages, 6 figures, presented at TGF, Paris, 200

Density functional approach to finite temperature nuclear properties and the role of a momentum dependent isovector interaction

Using a density functional approach based on a Skyrme interaction, thermodynamic properties of finite nuclei are investigated at non-zero temperture. The role of a momentum dependent isovector term is now studied besides volume, symmetry, surface and Coulomb effects. Various features associated with both mechanical and chemical instability and the liquid-gas coexistence curve are sensitive to the Skyrme interaction. The separated effects of the isoscalar term and the isovector term of momentum dependent interaction are studied for a modified SKM($m^*=m$) interaction. The frequently used Skyrme interaction SLy4 is one of the cases considered and is shown to have better features for neutron star studies due to a larger symmetry energy.Comment: 14 pages, 6 figures, added more discussio