Ethnobotanical Survey of Medicinal Plants in West Kordofan (Western Sudan)

The aim of the present study was primarily to evaluate the medicinal uses of the plants known to some western Kordofan tribes and to encourage preservation of their culture, conservation and sustainable utilization of the plant wealth. The present study revealed a record of 49 plant species belonging to 26 families which are used in the folk medicine of West Kordofan, Sudan. It is believed to be a form of healthcare in many aspects of curing practices. The plants were arranged alphabetically by their family name followed by species name, local name, parts used, mode of preparation and medicinal uses. This wisdom available with the tribes is transmitted only through oral communication therefore needs conservation

Self-sustained annihilation of magnetic islands in helical plasmas

The evolution of the magnetic island which is induced by the resonant deformation by external currents in helical systems (such as the large helical device (LHD) [A. Iiyoshi, Phys. Plasmas 2, 2349 (1995)]) is analyzed. The defect of the bootstrap current, caused by the magnetic island, has a parity which reduces the size of the magnetic island, if the bootstrap current enhances the vacuum rotational transform. The width of magnetic island can be suppressed to the level of ion banana width if the pressure gradient exceeds a threshold value. This island annihilation is self-sustained. That is, the annihilation continues, for fixed beta value, until the external drive for island generation exceeds a threshold. The effects of the reversal of the direction of the bootstrap current and of the sign of radial electric field are also investigated. The possibility of the neoclassical tearing mode in the LHD-like plasma is discussed

Self-annihilation of Magnetic Islands in Helical Plasmas

The evolution of the magnetic island which is induced by the resonant deformation by external currents in helical systems (such as LHD) is analyzed. The defect of the bootstrap current, caused by the magnetic island, has a parity which reduces the size of the magnetic island, if the bootstrap current enhances the vacuum rotational transform. The width of the externally-driven magnetic island can be suppressed to the level of ion banana width if the pressure gradient exceeds a threshold value. This island annihilation is self-sustained. That is, the annihilation continues, for fixed beta-value, until the external drive for island generation exceeds a threshold. Effects of the reversal of the direction of the bootstrap current and of the sign of radial electric field are also investigated. The possibility of the neoclassical tearing mode in the LHD-like plasma is discussed

Transition Probability to Turbulent Transport Regime

Transition phenomena between thermal noise state and turbulent state observed in a submarginal turbulent plasma are analyzed with statistical theory. Time-development of turbulent fluctuation is obtained by numerical simulations of Langevin equation which contains hysteresis characteristics. Transition rates between two states are analyzed. Transition from turbulent state to thermal noise state occurs in entire region between subcritical bifurcation point and linear stability boundary.Comment: 9 pages, 6 figures, to be published in Plasma Phys. Control. Fusio