Density profiles for a light impurity, boron, are reported for internal transport barrier (ITB) discharges in Alcator C-Mod. During the ITB, the light impurity gradient steepens because the impurity pinch increases relative to diffusion. The ITB-induced impurity profile steepening is at approximately the same major radius as that for the main-ion profile. Neoclassical transport does not describ...

Basic aspects of impurity reaction with dislocations in semiconductors are discussed on the basis of the work of the author's group. Some important insights into the mechanism of impurity reaction with extended structural defects are deduced from a theoretical treatment of impurity distribution around a structural defect in thermal equilibrium, experimental observations on dislocation pinning, ...

We present a comprehensive theoretical study of thermodynamic properties of superconductors with a dilute concentration of magnetic impurities, with focus on how the properties of the superconducting host change if the magnetic moments of the impurities order ferromagnetically. Scattering off the magnetic impurities leads to the formation of a band of Yu-Shiba-Rusinov states within the supercon...

Ion irradiation induced modifications of a periodic Pt/C multilayer system containing Fe impurity have been analyzed by X-ray techniques suitable for exploring nanometer depth scales with sub-nanometer depth resolution. The multilayer stack with 15 Pt/C layer pairs (period 4.23 nm, total thickness 63.45 nm) was fabricated on a glass substrate. A 2 MeV Au2þ ion beam was rastered on the sample to...

The strong radial electric field in a subsonic tokamak pedestal modifies the neoclassical ion parallel flow velocity, as well as the radial ion heat flux. Existing experimental evidence of the resulting alteration in the poloidal flow of a trace impurity is discussed. We then demonstrate that the modified parallel ion flow can noticeably enhance the pedestal bootstrap current when the backgroun...

Positron annihilation experiments have been applied to verify the formation mechanism of electrically inactive vacancy-impurity clusters in highly n-type Si. We show that the migration of V-As pairs at 450 K leads to the formation of V-As2 complexes, which in turn convert to stable V-As3 defects at 700 K. These processes manifest the formation of V-As3 as the dominant vacancy-impurity cluster i...

A sensitive and stable High Performance liquid chromatographic method has been developed for the identification of three process related impurities viz impurity-A, impurity-B and impurity-C in Dapoxetine hydrochloride. The method was optimized based on the peak shape and resolution of impurity-A, impurity-B and impurity-C. Phenomenex Luna C18 column (250mm×4.6 mm, 5um) was used for optimization...