Vortex Pair Creation on Brane-Antibrane Pair via Marginal Deformation

It has been conjectured that the vortex solution on a D-brane - anti-D-brane system represents a D-brane of two lower dimension. We establish this result by first identifying a series of marginal deformations which create the vortex - antivortex pair on the brane - antibrane system, and then showing that under this series of marginal deformations the original D-brane - anti-D-brane system becomes a D-brane - anti-D-brane system with two lower dimensions. Generalization of this construction to the case of solitons of higher codimension is also discussed.Comment: LaTeX file, 21 page

`Blowing up' D-branes on Non-supersymmetric Cycles

In the orbifold limit of K3, one can give exact conformal field theory description of D-branes wrapped on certain non-supersymmetric cycles of K3. We study the effect of switching on the `non-geometric blow up modes' corresponding to anti-symmetric tensor gauge field flux through the 2-cycles on these D-branes. Working to first order in the blow up parameter, we determine the region of the moduli space in which these D-branes are stable. Across the boundary of this region, the D-brane wrapped on the non-supersymmetric cycle decays to a pair of D-branes, each wrapped on a supersymmetric cycle, via a second order phase transition.Comment: LaTeX file, 24 pages, 4 figures, epsf.st

Timelike Boundary Sine-Gordon Theory and Two-Component Plasma

It has long been known that there is a relation between boundary sine-Gordon theory and thermodynamics of charge neutral two-component Coulomb plasma on a unit circle. On the other hand, recently it was found that open string worldsheet description of brane decay can be related to a sequence of points of thermodynamic equilibrium of one-component plasma. Here we consider a different decay process which is specifically described by the timelike boundary sine-Gordon theory. We find time evolution to be mapped to a one-dimensional curve in the space of points of thermal equilibrium of a non-neutral two-component Coulomb plasma. We compute the free energy of the system and find that along the curve it is monotonously decreasing, defining a thermodynamic arrow of time.Comment: 11 pages, v2: reference adde

On Superstring Disk Amplitudes in a Rolling Tachyon Background

We study the tree level scattering or emission of n closed superstrings from a decaying non-BPS brane in Type II superstring theory. We attempt to calculate generic n-point superstring disk amplitudes in the rolling tachyon background. We show that these can be written as infinite power series of Toeplitz determinants, related to expectation values of a periodic function in Circular Unitary Ensembles. Further analytical progress is possible in the special case of bulk-boundary disk amplitudes. These are interpreted as probability amplitudes for emission of a closed string with initial conditions perturbed by the addition of an open string vertex operator. This calculation has been performed previously in bosonic string theory, here we extend the analysis for superstrings. We obtain a result for the average energy of closed superstrings produced in the perturbed background.Comment: 15 pages, LaTeX2e; uses latexsym, amssymb, amsmath, slashed macros; (v2): references added, some typo fixes; (v3): reference adde

Orientifolds of type IIA strings on Calabi-Yau manifolds

We identify type IIA orientifolds that are dual to M-theory compactifications on manifolds with G_2-holonomy. We then discuss the construction of crosscap states in Gepner models. (Based on a talk presented by S.G. at PASCOS 2003 held at the Tata Institute of Fundamental Research, Mumbai during Jan. 3-8, 2003.)Comment: 3 pages, RevTeX, PASCOS '03 tal

Auxiliary Part of Ligand Mediated Unique Coordination Chemistry of Copper (II)

Six N,N,O-donor Schiff-base ligands, HL1-HL6, [HL1/HL2/HL3= {2-(2-piperazin-1-yl)ethylimino)methyl)-4-(Cl/H/Me)-phenol}; HL4/HL5/HL6={2-(2-morpholine/piperidine/ pyrrolidine 1-yl)ethylimino)methyl)-4-chlorophenol}, have been designed by combining 5-R-2-hydroxy-benzaldehyde, (R=Cl/H/Me) and N-(2-aminoethyl)-Y, (Y=piperazin/morpholine/ piperidine/pyrrolidine) with the view to explore the role of R and X (part of Y excluding coordinating N) on the coordination chemistry of Cu (II) in presence of bromide as counter anion. HL1-HL6 formed in situ on reaction with Cu(II)Br2 produce complexes 1\u20136, respectively. Complex 1, [Cu(II)2Cu(I)2(L1)(MeOH)2Br7.30], is a mixed valence Cu(I)-Cu(II) species having phenyl ring brominated at ortho position with 0.65 occupancy. Complexes 2\u20134 are mononuclear species with general formula [Cu{L2/L3/L4)}Br2]. Complexes [Cu3(L5)Br4] (5) and [Cu3(L6)Br4] (6) are trinuclear species having similar structure but exhibit different magnetic property, 5 is ferro- (J= +16.64 cm1 ) and 6 is antiferromegnetic (J= \u201311.76 cm1). The influence of R and X on bromination, magnetic property and nuclearity issues have been rationalized by DFT calculations

Field bioefficacy and residue dynamics of chlorantraniliprole (18.50% sc) in okra (Abelmoschus esculentus)

The okra fruit borer (Earias vittella) and sucking pests are a key limiting factor in okra cultivation due to their severe crop destruction behaviour. An experiment was conducted during 2019–20 to assess the bioefficacy of various new insecticides and persistence of chlorantraniliprole 18.50 sc residues in okra fruits at research farm of ICAR- Indian Institute of Vegetable Research, Varanasi, Uttar Pradesh. Among various treatments, chlorantraniliprole tested at 30 g a.i./ha was reported to be effective in reducing fruit damage by E. vittella (96%), as well as sucking pests infestation (87.81–1100%) with a significantly higher marketable fruit yield (8.88 t/ha) recorded under open field situations. Ethyl acetate was used to extract the chlorantraniliprole contaminants from the okra fruit matrix, and PSA and magnesium sulphate were used to clean up the matrix. The estimate for the limit of quantification (LOQ) was 0.01 mg/kg, and the average percent recoveries ranged from 83.67–89.00. The half-life was estimated 1.72 days. Based on the field bioefficacy against insect pests and residue status in okra fruits, it can be concluded that the chlorantraniliprole 30 g a.i./ha can be utilized in the okra ecosystem to successfully manage the sucking pest complex and fruit borer without posing any health risks to consumers