Non-BPS D-Branes in Light-Cone Green-Schwarz Formalism

Non-BPS D-branes are difficult to describe covariantly in a manifestly supersymmetric formalism. For definiteness we concentrate on type IIB string theory in flat background in light-cone Green-Schwarz formalism. We study both the boundary state and the boundary conformal field theory descriptions of these D-branes with manifest SO(8) covariance and go through various consistency checks. We analyze Sen's original construction of non-BPS D-branes given in terms of an orbifold boundary conformal field theory. We also directly study the relevant world-sheet theory by deriving the open string boundary condition from the covariant boundary state. Both these methods give the same open string spectrum which is consistent with the boundary state, as required by the world-sheet duality. The boundary condition found in the second method is given in terms of bi-local fields that are quadratic in Green-Schwarz fermions. We design a special ``doubling trick'' suitable to handle such boundary conditions and prescribe rules for computing all possible correlation functions without boundary insertions. This prescription has been tested by computing disk one-point functions of several classes of closed string states and comparing the results with the boundary state computation.Comment: 47 pages, 1 figure. Typos corrected, references added and slight modification of certain explanation made. Version accepted for publication in JHE

Computer program for nonlinear least square analysis of impedance and admittance data

A computer program to estimate the parameter value from the complex impedance data of the equivalent circuit is reported. Non-linear complex least squares fitting is made using a laboratory microcomputer (with real values). Different values are used as the initial guess in the iterative calculation of complex least-square method which fits both real and imaginary components of the actual impedance. The program is tested for simple RC circuits which are generally used to model the electrochemical system by introducing random experimental errors and it is found to converge within a few number of iteration

Solid electrolyte systems - recent trends

Solid electrolytes, which possess high ionic conductivitiescomparable with those of aqueous electrolytes, have received much attention in the last decade, as they play a major role in the field of miniaturisation particularly as power sources. Recent developments in the field from the point of view of materials, development of proper electrodes for battery applications, the process of intercalation are highlighted. An account of the important electrochemical device applications is dealt with

Photoluminescence of oxygen dominated phosphors

The mechanism of fluorescence in (a) CaW04, (b) Zn2Si04:Mn, (c) 3.5 MgO + 0.5 MgF2 + GeO, : Mn, and (dl 3Ca,(P04), Ca(F, C1)2:Sb3+, Mn2+ under excitation by shortwave ultraviolet is explained by the electronic transitions involved in the activators. To get a daylight phosphor conforming to 6500"K, a blending of a sb3+ activated halophosphate blue phosphor and a Sb3+ and Mn2+ activated warmwhite phosphor is essential and the successful preparation of the same is presente

Surface treatments of fluorine doped tin oxide films

Fluorinedoped tin oxide films prepared by spray pyrolysis were subjected to chemical etching using hydrazine hydrate, mechanical polishing and electrochemical etching (cathodic), and the consequent changes in the sheet resistance and optical transmiss~on of the films are reported. Scanning electron microscopic examination revealed a change in the surface morphology of the film

Photoluminescence of oxygen dominated phosphors

The mechanism of fluorescence in (a) CaW04, (b) Zn2Si04:Mn, (c) 3.5 MgO + 0.5 MgF2 + GeO, : Mn, and (dl 3Ca,(P04), Ca(F, C1)2:Sb3+, Mn2+ under excitation by shortwave ultraviolet is explained by the electronic transitions involved in the activators. To get a daylight phosphor conforming to 6500"K, a blending of a sb3+ activated halophosphate blue phosphor and a Sb3+ and Mn2+ activated warmwhite phosphor is essential and the successful preparation of the same is presente