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The Coulomb-Born approximation has been formulated for the capture of an electron, initially bound to a nucleus of nuclear charge Z,, by a bare nucleus of charge Z, in the high-energy region. The earlier Coulomb-Born formulations for electron capture in asymmetric collisions are derivable from the present formulation. The simple replacement of the outgoing and incoming scattering wavefunctions in the Coulomb-Born approximation by their asymptotic forms is shown to reproduce the recently revived first-order Born approximation for charge exchange with Coulomb boundary conditions. A semiclassical version of the Coulomb-Born approximation is also presented in which its relation to the distorted-wave solution of the two-state coupled equations is established. The Coulomb-Born approximation is illustrated by its application to the computation of total cross sections for charge exchange in H+ + Ne collisions. An independent-particle model is employed with a one-electron orbital for the target. The present calculated results with hydrogen-like wavefunctions are found to be in good agreement with experimental data in the intermediate-energy region.

Newly observed instances of reverse migration, i.e., migration from urban to rural areas, suggest the possibility that the labor market adjustment process could be unstable. We provide a theoretical analysis of this conjecture using a Harris-Todaro-Lewis model. A bifurcation analysis is presented that shows how various stable and unstable adjustments are possible including chaotic fluctuations and how these possibilities are related to adjustment speed, the productivity of industry and agriculture, and the relative importance of industry and population size. Examples of unstable adjustments in a hypothetical LDC and DC are given using "plausible" parameter values.

This study reports the performance analysis of an organic dye-sensitized solar cell (DSSC), introducing MnO2 as an electron transport layer in TiO2/MnO2 bilayer assembly. The DSSCs have been fabricated using TiO2 and TiO2/MnO2 layer-by-layer architecture films onto fluorine-doped tin oxide (FTO) glass and sensitized with natural dye extracted from Malvaviscus penduliflorus flower in ethanol medium. The counter electrode was prepared to layer copper powder containing paste onto FTO's conductive side by the doctor's blade method. The optical, morphological, and structural properties of photoanodes were explored via ultraviolet–visible, field emission scanning electron microscopy, and X-ray diffraction analyses. Moreover, dye complexity and thermostability of dyes were characterized via Fourier-transform infrared spectroscopy and thermogravimetric analyses. The iodide/triiodide (i.e., I−/I3−) redox couple of electrolyte solution was employed as a charge transport medium between the electrodes. Finally, photoanode and counter electrode sandwiches were assembled to envisage the photovoltaic performance potential under simulated AM 1.5G solar illumination using 100 mW cm–2 light intensity. The as-fabricated DSSC comprising TiO2/MnO2 bilayer assembly exhibited 6.02 mA cm–2 short circuit current density (Jsc), 0.38 V open-circuit voltage (Voc), 40.38% fill factor, and 0.92% conversion efficiency, which is about 200% higher compared to the assembly devoid of MnO2 layer.

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