La lucha por el mercado del petróleo alemán en los inicios del régimen de Hitler

On the basis of diplomatic documents, the paper reconstructs a detailed picture of the expulsion from the German market during 1933 of the Soviet firms “Derop” and “Derunaft”, suppliers of oil products. The document of Soviet intelligence shows that a big Dutch-British oil magnate, Sir H. Deterding, can be considered one of the inspirers of this process; he hoped, among other things, to seize control of the Caucasian oil fields in the course of the alleged "crusade" against the USSR.Sobre la base de documentos diplomáticos, el artículo reconstruye un cuadro detallado de la expulsión del mercado alemán durante 1933 de las empresas soviéticas "Derop" y "Derunaft", proveedoras de productos petrolíferos. Los materiales de la inteligencia soviética muestran que uno de los inspiradores de este proceso puede ser considerado el gran magnate petrolero holandés-británico Sir H. Deterding, quien, en el curso de la supuesta "cruzada" contra la URSS, esperaba, entre otras cosas, tomar el control de los campos petroleros del Cáucaso

Selberg Supertrace Formula for Super Riemann Surfaces III: Bordered Super Riemann Surfaces

This paper is the third in a sequel to develop a super-analogue of the classical Selberg trace formula, the Selberg supertrace formula. It deals with bordered super Riemann surfaces. The theory of bordered super Riemann surfaces is outlined, and the corresponding Selberg supertrace formula is developed. The analytic properties of the Selberg super zeta-functions on bordered super Riemann surfaces are discussed, and super-determinants of Dirac-Laplace operators on bordered super Riemann surfaces are calculated in terms of Selberg super zeta-functions.Comment: 43 pages, amste

Optimal length of low Reynolds number nanopropellers

Locomotion in fluids at the nanoscale is dominated by viscous drag. One efficient propulsion scheme is to use a weak rotating magnetic field that drives a chiral object. From bacterial flagella to artificial drills, the corkscrew is a universally useful chiral shape for propulsion in viscous environments. Externally powered magnetic micro- and nanomotors have been recently developed that allow for precise fuel-free propulsion in complex media. Here, we combine analytical and numerical theory with experiments on nanostructured screw-propellers to show that the optimal length is surprisingly short–only about one helical turn, which is shorter than most of the structures in use to date. The results have important implications for the design of artificial actuated nano- and micropropellers and can dramatically reduce fabrication times, while ensuring optimal performance