Response of Hainan GPS ionospheric scintillations to the different strong magnetic storm conditions

Using the GPS ionospheric scintillation data at Hainan station (19.5°N, 109.1°E) in the eastern Asia equatorial regions and relevant ionospheric and geomagnetic data from July 2003 to June 2005, we investigate the response of L-band ionospheric scintillation activity over this region to different strong magnetic storm conditions (Dst < −100 nT) during the descending phase of the solar cycle. These strong storms and corresponding scintillations mainly took place in winter and summer seasons. When the main phase developed rapidly and reached the maximum near 20–21 LT (LT = UT + 8) after sunset, scintillations might occur in the following recovery phase. When the main phase maximum occurred shortly after midnight near 01–02 LT, following the strong scintillations in the pre-midnight main phase, scintillations might also occur in the post-midnight recovery phase. When the main phase maximum took place after 03 LT to the early morning hours no any scintillation could be observed in the latter of the night. Moreover, when the main phase maximum occurred during the daytime hours, scintillations could also hardly be observed in the following nighttime recovery phase, which might last until the end of recovery phase. Occasionally, scintillations also took place in the initial phase of the storm. During those scintillations associated with the nighttime magnetic storms, the height of F layer base (h’F) was evidently increased. However, the increase of F layer base height does not always cause the occurrence of scintillations, which indicates the complex interaction of various disturbance processes in ionosphere and thermosphere systems during the storms.     

The Hydrogen Exospheric Density Profile Measured with ASPERA-3/NPD

We have evaluated the Lyman-α limb emission from the exospheric hydrogen of Mars measured by the neutral particle detector of the ASPERA-3 instrument on Mars Express in 2004 at low solar activity (solar activity index = 42, F_10.7=100). We derive estimates for the hydrogen exobase density, n _H = 10¹⁰ m^?3, and for the apparent temperature, T > 600 K. We conclude that the limb emission measurement is dominated by a hydrogen component that is considerably hotter than the bulk temperature at the exobase. The derived values for the exosphere density and temperature are compared with similar measurements done by the Mariner space probes in the 1969. The values found with Mars Express and Mariner data are brought in a broader context of exosphere models including the possibility of having two hydrogen components in the Martian exosphere. The present observation of the Martian hydrogen exosphere is the first one at high altitudes during low solar activity, and shows that for low solar activity exospheric densities are not higher than for high solar activity.     

The Plasma and Suprathermal Ion Composition (PLASTIC) Investigation on the STEREO Observatories

The Plasma and Suprathermal Ion Composition (PLASTIC) investigation provides the in situ solar wind and low energy heliospheric ion measurements for the NASA Solar Terrestrial Relations Observatory Mission, which consists of two spacecraft (STEREO-A, STEREO-B). PLASTIC-A and PLASTIC-B are identical. Each PLASTIC is a time-of-flight/energy mass spectrometer designed to determine the elemental composition, ionic charge states, and bulk flow parameters of major solar wind ions in the mass range from hydrogen to iron. PLASTIC has nearly complete angular coverage in the ecliptic plane and an energy range from ～0.3 to 80 keV/e, from which the distribution functions of suprathermal ions, including those ions created in pick-up and local shock acceleration processes, are also provided.     

Reconstruction of space weather physical parameters on 400-year scale

The main goal of this paper is to get physically informative comprehensive data about dynamics of the solar magnetic field, geomagnetic field, and interplanetary magnetic field over large time scales. The total sunspot magnetic flux, aa and IDV indices of geomagnetic activity, the IMF strength, the dipole-octopole index of the large-scale magnetic field of the Sun, and the open magnetic flux are reconstructed for 400 years. The reconstruction of the π index of the large-scale polar magnetic field of the Sun is performed for 150 years.     

Skylab experiment results: hematology studies

These studies were designed and coordinated to evaluate specific aspects of man's immunologic and hematologic systems which might be altered by or respond to the space flight environment. The biochemical functions investigated included cytogenetic damage to blood cells, immune resistance to disease, regulation of plasma and red cell volumes, metabolic processes of the red blood cell, and physical chemical aspects of red blood cell functions. Only minor changes were observed in the functional capacity of erythrocytes as determined by measuring the concentrations of selected intracellular enzymes and metabolites. Tests of red cell osmotic regulation indicated some elevation in the activity of the metabolic dependent Na-K pump, with no significant alterations in the cellular Na and K concentrations or osmotic fragility. A transient shift in red cell specific-gravity profile was observed on recovery, possibly related to changes in cellular water content. Measurements of hemoconcentration (hematocrit, hemoglobin concentration, red cell count) indicated significant fluctuations postflight, reflecting observed changes in red cell mass and plasma volume. There was no apparent reticulocytosis during the 18 days following the first manned Skylab mission in spite of a significant loss in red cell mass. However, the reticulocyte count and index did increase significantly 5 to 7 days after completion of the second, longer duration, flight. There were no significant changes in either the while blood cell count or differential. However, the capacity of lymphocytes to respond to an in vitro mitogenic challenge was repressed postflight, and appeared to be related to mission duration. The cause of this repression is unknown at this time. Only minor differences were observed in plasma protein patterns. In the second mission there were changes in the proteins involved in the coagulation process which suggested a hypercoagulative condition.     

Skylab experiment M-092: results of the first manned mission

Blood pressure at 30-sec intervals, heart rate, and percentage increase in leg volume continuously were recorded during a 25-min protocol in the M092 Inflight Lower Body Negative Pressure (LBNP) experiment carried out in the first manned Skylab mission. These data were collected during six tests on each crewman over a 5-month preflight period. The protocol consisted of a 5-min resting control period, 1 min at -8, 1 min at -16, 3 min at -30, 5 min at -40, and 5 min at -50 mm Hg LBNP. A 5-min recovery period followed. Inflight tests were performed at approximately 3-day intervals through the 28-day mission. Individual variations in cardiovascular responses to LBNP during the preflight period continued to be demonstrated in the inflight tests. Measurements of the calf indicated that a large volume of fluid was shifted out of the legs early in the flight and that a slower decrease in leg volume, presumably due to loss of muscle tissue, continued throughout the flight. Resting heart rates tended to be low early in the flight and to increase slightly as the flight progressed. Resting blood pressure varied but usually was characterized by slightly elevated systolic blood pressure, lower diastolic pressure, and higher pulse pressures than during preflight examinations. During LBNP inflight a much greater increase in leg volume occurred than in preflight tests. Large increases occurred even at the smallest levels of negative pressure, suggesting that the veins of the legs were relatively empty at the beginning of the LBNP. The greater volume of blood pooled in the legs was associated with greater increases of heart rate and diastolic pressure and larger falls of systolic and pulse pressure than seen in preflight tests. The LBNP protocol represented a greater stress inflight, and on three occasions it was necessary to stop the test early because of impending syncopal reactions. LBNP responses inflight appeared to predict the degree of postflight orthostatic intolerance. Postflight responses to LBNP during the first 48 hours were characterized by marked elevations of heart rate and instability of blood pressure. In addition, systolic and diastolic pressures were typically elevated considerably both at rest and also during stress. The time required for cardiovascular responses to return to preflight levels was much slower than in the case of Apollo crewmen.     

Postmission plasma volume and red-cell mass changes in the crews of the first two Skylab missions

Red-cell mass determinations were performed before and after the first two Skylab missions. The data showed a 14% mean decrease in red-cell mass after the 28-day mission and a 12% mean decrease after the 59-day mission. The red-cell mass returned to premission levels more slowly after the shorter (28-day) than after the longer mission. Plasma volume decreases were found after each mission. with the crew from the longer mission showing the greater change (13% vs. 8.4%). Postmission decreases in red-cell mass and plasma volume have been a general finding in crewmen who return from short or long spaceflight.     

Influence of geometry and operating conditions of a centrifugal compressor stage on the radial gas force

The influence of geometry and operating conditions of the centrifugal compressor stage on the radial gas force is determined on the basis of the theoretical method and calculation program using experimental boundary conditions.     

Vibrations of an elastic guide beam with a missile moving along it

Transverse nonstationary vibrations of a guide beam having the initial flexure are considered. An absolutely rigid missile moves under the propulsive force along this guide beam on two sliding supports. The beam displacements introduced by its vibrations are presented as an expansion with respect to the given functions according to the Ritz method. The equations of nonstationary vibration of the beam with the missile moving along it are obtained in the generalized coordinates, the expansion coefficients being chosen as them. The example is presented. Also studied is the effect of different beam and missile parameters on the beam displacement and transverse and angular velocity of the missile.     

Water feed influence on nitric oxide emission under oxidation of near-stoichiometric air-methane mixtures

We considered the influence of temperature on the nitric oxide emission under combustion of the near-stoichiometric mixtures with and without water feed. We revealed the advantage of the method of fuel-water-air mixture combustion over that of the leaned mixture combustion.