The effect of the longitudinal propagating waves on the electron acceleration in the reconnecting current sheet

Based upon the most efficient electron acceleration near the midplane of 3D non-neutral driven reconnecting current sheet (RCS) and the electrostatic wave excitation by the drift Maxwellian distribution of electrons in Vlasov simulation, we assume that the electrostatic waves mainly propagate opposite to the reconnecting electric field and investigated how these waves affect the electron acceleration. The main results are: (1) when the electron’s velocity equals to the phase speed of the waves, they will be trapped and have the different accelerating characteristics from the untrapped electrons through solving the momentum equations of electrons analytically; (2) the test particle simulations further prove that the number of the energetic electrons decreases with the increasing intensity of unstable waves, and the distribution of the energetic electrons takes on the double power-law.     

Exposure to altered gravity affects all stages of endochondral cartilage differentiation.

Chondrogenesis has a number of well-defined steps: (1) condensation, which involves cell aggregation, adhesion and communication; (2) activation of cartilage genes, which is accompanied by rounding up of the cells and intracellular differentiation; and (3) production and secretion of cartilage specific matrix molecules. Our studies show that each of these steps is affected by exposure to gravitational changes. Clinorotation and centrifugation affected initial aggregation and condensation. In the CELLS experiment, where cells were exposed to microgravity after some condensation occurred preflight, intracellular differentiation and matrix production were delayed relative to controls. Once cartilage has developed, in rats, further differentiation (hypertrophy, matrix production) was also affected by spaceflight and hind limb suspension. For the process of chondrogenesis to proceed as we know it, loading and other factors present at 1g are required at each step of the process. This requirement means that not only will skeletal development and bone healing, processes involving chondrogenesis, be altered by long term exposure to microgravity, but that continuous intervention will be necessary to correct any defects produced by altered gravity environments.     

Comparative Utilization of Limited Energy for Continuous and Pulse Operations

Comparative utilization of a limited amount of energy for continuous and pulse operations was investigated. Under a restriction that the amount of available energy was limited, general equations for operational hours of the energy source for given power output were derived for both continuous and pulse mode operations. This paper points out that due to various adjustable parameters available for pulse mode operation, if properly designed pulse mode operation produces longer utilization of available energy for required output power than continuous mode operation.     

The STEREO/IMPACT Magnetic Field Experiment

The magnetometer on the STEREO mission is one of the sensors in the IMPACT instrument suite. A single, triaxial, wide-range, low-power and noise fluxgate magnetometer of traditional design—and reduced volume configuration—has been implemented in each spacecraft. The sensors are mounted on the IMPACT telescoping booms at a distance of ～3 m from the spacecraft body to reduce magnetic contamination. The electronics have been designed as an integral part of the IMPACT Data Processing Unit, sharing a common power converter and data/command interfaces. The instruments cover the range ±65,536 nT in two intervals controlled by the IDPU (±512 nT; ±65,536 nT). This very wide range allows operation of the instruments during all phases of the mission, including Earth flybys as well as during spacecraft test and integration in the geomagnetic field. The primary STEREO/IMPACT science objectives addressed by the magnetometer are the study of the interplanetary magnetic field (IMF), its response to solar activity, and its relationship to solar wind structure. The instruments were powered on and the booms deployed on November 1, 2006, seven days after the spacecraft were launched, and are operating nominally. A magnetic cleanliness program was implemented to minimize variable spacecraft fields and to ensure that the static spacecraft-generated magnetic field does not interfere with the measurements.     

Computer-aided simulation of the AMg6 alloy rolling process with allowance for its anisotropy

Some data obtained in the course of computer-aided simulation of a process of plane AMg6 alloy specimen rolling in the CAE-system MSC.SuperForm are presented. The influence of a real material structure upon the stress-strain state and the flow pattern of layers throughout the specimen height is taken into account. Also determined are the values of total pressure of metal on the rolls and a moment of rolling with the use of the isotropic and anisotropic finite element models (FEM) of specimens.     

Multi-Criteria Decision Analysis integrated with GIS and remote sensing for astronomical observatory site selection in Antalya province,Turkey

Astronomical observatory site selection is a complex problem that involves evaluation of multiple factors from different sources. The aim of this study is to select the best possible candidates for astronomical observations sites using Multi-Criteria Decision Analysis integrated with Geographical Information Systems and remote sensing technologies. The study was implemented in the Antalya province of Turkey, which is convenient for astronomical site observatory facilities with its appropriate climate properties and weather conditions. Eleven factors (cloud cover, precipitable water, earthquake zones, geology, landslide inventory, active fault lines, Digital Elevation Model, city lights, mining activities, settlement areas, roads) were determined, splitting into three categories; meteorological, geographical and anthropogenic criteria. These factors were evaluated using Analytical Hierarchy Process method and the weights of criteria layers were determined. As a result, the most suitable areas were located extensively in western and eastern part of Antalya. This study offers a robust, accurate, cost and time effective procedure for preliminary site selection for astronomical observatory. However, for a final decision of the best location of astronomical observatory, site testing measurements and atmospheric seeing observations will be further required in these preliminary areas.     

Numerical study of transient interchamber processes when reaching the SPRE operational conditions

A comprehensive numerical study of transient interchamber processes occurring when reaching the SPRE operational conditions is carried out. A conjugate problem under consideration includes nonstationary operation of an igniter heating, ignition and subsequent nonstationary and turbulent burning of a solid-propellant charge; nonstationary three-phase homo-heterogeneous flow of combustion products in the combustion chamber, nozzle and downstream of the nozzle block of a rocket engine; motion of a nozzle block cover. The calculation results are presented.     

Calculation of decoupling zeroes in the multiconnected dynamic system

A recursive method for calculating decoupling zeroes in the linear multiconnected dynamic system based on the application of matrix canonization techniques is proposed. Its essence is that the problem dimension is successively decreased and reduced to finding eigenvalues of some matrix. The results obtained can be used to check controllability and observability as well as to calculate uncontrollable and unobservable modes of the dynamic system.