To reduce costs, the solar cell industry aims at producing thinner cells. Structuring surfaces of optically thin devices is important for avoiding transmission-related losses and, hence, increasing their efficiency. Light trapping leads to longer optical pathlengths and increased absorption energy. In addition, resonances in nanostructures enhance energy-converting material. Further, periodic s...

two possible isomers of some 1,3-diaryl-h-benzo[f]chromene have been studied using density functional theory. structures of e1 and e2 isomers were optimized at the b3lyp and mp2 levels with different basis sets. the total electronic energies show that e2 isomer is about 3-5 kcal/mol more stable than e1 isomer and this energy difference is attributed to the planarity of heterocyclic ring and mor...

in today's design, system complexity and increasing demand for safer, more efficient and less costly systems have created new challenges in science and engineering. locomotives are products which are designed according to market order and technical needs of customers. accordingly, targets of companies, especially designers and manufacturers of locomotives, have always been on the path of progre...

We investigate kink-antikink scattering in the $\lambda \phi^4$ model presence of an additional scalar field, $\psi$, that is its quantum vacuum and interacts with $\phi$ via a $\xi \phi^2\psi^2$ term where $\xi$ coupling. The final state such either bound eventual annihilation or reflection pair. Without $\psi$ outcome known to depend fractally on initial velocity In fractal dependence gets mo...