Short term topological changes of coronal holes associated with prominence eruptions and subsequent CMEs

We study the short-term topological changes of equatorial and polar coronal hole (CH) boundaries, such as a variation of their area and disintegration, associated to reconnection with nearby (within 15° distance) quiescent prominence magnetic fields leading to eruptions and subsequent Coronal Mass Ejections (CMEs). The examples presented here correspond to the recent solar minimum years 2008 and 2009. We consider a temporal window of one day between the CH topological changes and the start and end times of prominence eruptions and onset of CMEs. To establish this association we took into account observational conditions related to the instability of prominence/filaments, the occurrence of a CME, as well as the subsequent evolution after the CME. We found an association between short-term local topological changes in CH boundaries and the formation/disappearance of bright points near them, as well as, between short-term topological changes within the whole CH and eruptions of nearby quiescent prominences followed by the appearance of one or more CMEs.     

Geosynchronous magnetic field response to the large and fast solar wind dynamic pressure change

We present a comparison of large and sharp solar wind dynamic pressure changes, observed by several spacecraft, with fast disturbances in the magnetospheric magnetic field measured by the GOES-8, 9 and 10 geosynchronous satellites. Almost 400 solar wind pressure changes in the period 1996–2003 were selected for this study. Using the large statistics we confirmed that increases (decreases) in the dynamic pressure always results in increases (decreases) in the magnitude of geosynchronous B_z component. The amplitude of the geosynchronous B_z response strongly depends on the location of observer relative to the noon meridian, from the value of solar wind pressure before the disturbance arriving and firstly – from the amplitude of the pressure change.     

The gravitational field and brain function.

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the "frontalization" of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: "encephalization", "corticalization", "lateralization" and "frontalization". The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.     

Frequency Domain Error Correction for Monopulse Radar Signals

Angle-measurement error of a coherent monopulse radar signalresulting from imbalances between in-phase and quadraturecomponents, as well as between sigma and delta channels, arecorrected in a simple procedure. No correction is needed for I,Qimbalances in the time domain [1]. Instead, a postintegrationcorrection is performed. This reduces the number of calibrationoperations of the monopulse signal by a factor X, 2 ? X ? N (N isthe number of DFT samples), depending on the degree of filtering.It also reduces the number of numerical operations necessary forthe production of the correction term by a factor of three. A firstorderrder estimation is made of the residual error after correction, dueto bias and image sidelobes.     

Modeling gas exchange in a closed plant growth chamber.

Fluid transport models for fluxes of water vapor and CO2 have been developed for one crop of wheat and three crops of soybean grown in a closed plant growth chamber. Correspondence among these fluxes is discussed. Maximum fluxes of gases are provided for engineering design requirements of fluid recycling equipment in growth chambers. Furthermore, to investigate the feasibility of generalized crop models, dimensionless representations of water vapor fluxes are presented. The feasibility of such generalized models and the need for additional data are discussed.     

Effects of salts and temperatures on post-irradiation growth of penicillium exposed to ultraviolet

The growth of Penicillium notatum colonies after UV irradiation of dried mycelium or spores was studied in relation to post-irradiation temperature and salt environment. Dried mycelium and spores behaved differently with respect to sensitivity to temperature, salts and UV, especially the latter. Threshold inhibitory doses for spores were modified markedly either at 4°C or in magnesium and calcium chlorides. It is suggested that these temperature and salt effects are related to prevention of photochemical membrane damage.     

Corotating events in the energy range 4–13 MeV as observed on board Helios 1 and 2 in 1975 and 1976

Intensity increases of 4 – 13 MeV protons correlated with recurrent high speed solar wind streams were observed on board Helios 1 and 2 at heliocentric distances between 0.3 and 1.0 AU. Study of events which occurred in the time period 1975 – 1976 showed that recurrent fast solar wind streams were sometimes not accompanied by corotating events and small events were more frequently observed than large corotating events, which occurred only occasionally. The explanation for these phenomena seems to be the variation of the number of suprathermal particles injected into the acceleration process. Radial gradients of corotating events from February till April 1976 were investigated. The gradient changed its sign in successive solar rotations and exhibited strong time dependence inside 1 AU. Clearly negative gradients were measured in corotating events which occurred in February and April 1976. These observations showed that probably there were no stationary corotating structures in interplanetary space. We suggest that this effect is related to local disturbances of solar origin, e. g. flare initiated shocks.     

On Conopulse Radar Theoretical Angle Tracking Accuracy

The Cramer-Rao analysis method is applied to a conopulse radar to determine a lower bound on the variance of angle tracking error. The analysis allows the calculation of the variance independent of the form of the signal processor attached to the antenna. Under reasonable assumptions it is found that angle error variance is larger than that of a similar monopulse system by a factor of 2.     

Modeling of a new ZVS bi-directional dc-dc converter

A dual half-bridge (DHB) bidirectional dc-dc converter is a new proposed topology that has the advantages of decreased number of devices, soft-switching implementation, low cost, and high efficiency. Typical applications of this converter are the auxiliary power supply in fuel cell vehicles and battery charging and discharging systems where the power density, cost, weight, and reliability are critical factors. A switching-frequency-dependent state-space averaged model of the converter is developed here for either direction of power flow. This averaged model can be used to derive the steady-state characteristics and small signal dynamics of the proposed topology. It also provides a fast simulation tool to investigate the transient response of the converter. The simulated waveforms of the mathematical model are compared with the detailed circuit simulation to verify the accuracy of the modeling.     

Modeling international cooperation for space exploration

Space exploration into the twenty-first century is contingent upon the ability of states to forge an appropriate vehicle for international cooperation. A theoretical framework that explains international cooperation in space exploration is proposed. This framework encompasses scientific, technological, political, and economic initial conditions, state and nonstate political actors, and models of cooperation that explain how initial conditions and actors interact to realize cooperative outcomes. It is hypothesized that the prevailing initial conditions favor certain political actors over others which, in turn, promote a specific model of cooperation. Cooperative policy outcomes are examined and assessed vis-à-vis case studies of cooperation in space exploration. On this basis, policy recommendations that engender effective cooperative outcomes in space exploration are suggested.