A Maximum of Temperature in the Middle Ionosphere
J. FUCHS1 has already pointed out the fact that from the change of electron-density (N) with height (h) conclusions as to the temperature in the ionosphere can be drawn. It was, however, not possible then to carry out exact calculations for two reasons: first, the electron-density was only known to be dependent on the apparent height (h′), and secondly, the process of electron loss was not known in more detail, so that Fuchs had to calculate with a recombination-coefficient constant as to space and time.
A study of lymphocyte behavior in cultures of fibroblast-like lymphoreticular cells.
Abstract Fibroblast-like reticular cells were isolated from mouse lymph node and spleen and maintained in culture. These cells were found to be highly phagocytic and possess receptors for the Fc portion of immunoglobulin and for activated complement. These cells, unlike fibroblasts from other sources, were found to bind both syngeneic and allogeneic thymocytes and peripheral lymphocytes in large numbers. Thymocytes consistently bind in larger numbers than peripheral lymphocytes and there appears to be a qualitative difference in this binding. Identification of the bound cells using immunofluorescent techniques showed that more than 90% of bound peripheral lymphocytes are B cells. Microcinematographic studies suggest that lymphocytes, normally very nonadhesive, move readily over and between confluent layers of reticular cells. The significance of these observations to lymphocyte recirculation and positioning is discussed.
Simulation study of high power microwave generation by virtual cathode oscillation in coaxial vircator
Summary form only given, as follows. We have numerically simulated the high power microwave generation by virtual cathode oscillation in a coaxial vircator with 3 dimensional PIC code Magic. It is noted that the coaxial vircator has the advantage of an enhancement of power efficiency and gaining of narrow bandwidth frequency. The study is focused on the design of a diode structure for a coaxial vircator suitable for Chundoong IREB pulser (Max. 600 kV, 85 kA, 60 ns). It consists of a center annular cathode, a cylindrical meshed-anode and a reflector. The simulation results showed that the coaxial vircator can indeed be operated at the selected frequency with the narrow bandwidth and the microwave output power strongly depends on the position and geometry of the reflector. From this simulation results we expect that the maximum microwave output power will be obtained by the reflector of 4 cm in width and also 4 cm in distance away from the IREB, where the resonant frequency of microwave from coaxial vircator is simulated to be 6.577 GHz.