Two approaches are proposed for solving inverse problems in shape optimization. We are looking for the unknown position of a small hole in a domain Ω. First, the asymptotic analysis of the underlying p.d.e. defined in a perturbed domain is performed and the so-called topological derivative is defined. Then, in the first approach, the self-adjoint extensions of elliptic operators are used to mod...

A highly sensitive hybrid perovskite photodetector is demonstrated to be able to directly resolve light irradiance down to sub-picowatts per square centimeter, in good accordance with the calculated noise equivalent power, which is enabled by electron and hole transport layer engineering, especially the trap passivation effect of the double fullerene layer.

BACKGROUND On completion of the surgical procedure the hole in the ascending aorta has to be closed after withdrawal of the aortic root cannula. The aorta is usually pinched by a double transversal stitch or it is crumpled by a purse string suture. Nevertheless, hemostasis is difficult to obtain because closure is done under recovered pressure. Additional stitches buttressed with teflon-felt pl...

After considering the reference case of the motion of spinning test bodies in the equatorial plane of the Schwarzschild space-time, we generalize the results to the case of the motion of a spinning particle in the equatorial plane of the Schwarzschild-de Sitter space-time. Specifically, we obtain the loci of turning points of the particle in this plane. We show that the cosmological constant af...

Initially poorly conducting PbSe nanocrystal solids (quantum dot arrays or superlattices) can be chemically "activated" to fabricate n- and p-channel field effect transistors with electron and hole mobilities of 0.9 and 0.2 square centimeters per volt-second, respectively; with current modulations of about 10(3) to 10(4); and with current density approaching 3 x 10(4) amperes per square centime...