Weak Wave Turbulence Scaling Theory for Diffusion and Relative Diffusion in Turbulent Surface Waves

We examine the applicability of the weak wave turbulence theory in explaining experimental scaling results obtained for the diffusion and relative diffusion of particles moving on turbulent surface waves. For capillary waves our theoretical results are shown to be in good agreement with experimental results, where a distinct crossover in diffusive behavior is observed at the driving frequency. For gravity waves our results are discussed in the light of ocean wave studies.Comment: 5 pages; for related work visit http://www.imedea.uib.es/~victo

Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 8 PACS 85

Abstract. We consider the features of formation of AuTiPd ohmic contacts to p + -Si. Metallization was made by vacuum thermal sputtering of Pd, Ti and Au films onto the Si substrate heated up to 330 С. It is shown that the contact resistivity increases with temperature; this is typical of metallic conductivity. We suggest that the ohmic contact is formed owing to appearance of shunts at Pd deposition on dislocations or other structural defects. The number of shunts per unit area is close to the measured density of structural defects at the metalSi interface

Strike-slip related continental rifting of the eastern margin of Asia

The present paper considers the research of the Cretaceous-Cenozoic rifting for the Eastern margin of Asia occurring under the strike-slip related geodynamic regime, which resulted from development of the Eastern Asian global strike-slip fault zone (EAGSSFZ). The EAGSSFZ infrastructure proves to be recognized. It includes the longitudinal system of the NE (25-30°) trending sinistral faults, which form the through strike-slip fault zone to be pivot for the EAGSSFZ, together with two diagonal systems: the NE (50-70°) trending near-continental system of obligue-reverse-slip faults and the N-S trending near-oceanic fault system, which are feathering for the pivot zone. The paragenesis of the longitudinal and diagonal near-continental systems is studied. There are two paragenetic stages of their development: 1) the Jurassic-to-Early-Cretaceous orogenic stage is to be an effect of the formation of the diagonal system of the fold-thrust dislocations as compression structures of the longitudinal sinistral fault system (orogenic strike-slip related constriction of masses continued through the end of Early Cretaceous); 2) the Late-Cretaceous-to-Cenozoic riftogenic stage is to be an effect of riftogenic extension (pulling apart) of the crustal block bounded by the sinistral faults of the longitudinal system and due to the rifting that was caused by substitution (within the diagonal system) of predominantly reverse-and-thrust fault kinematics (of the 1st stage) for sinistral slips with development of the riftogenic extension structures controlling sedimentary basins along the strike-slip faults. At the same time, the sinistral activation of the diagonal fault system comprising the Bohai-Amur (BA) zone caused transformation of the Tan-Lu (TL) strike-slip fault into the extension structure, forming here the up-to-80-km-wide riftogenic trough with subsidence of its sides that led to formation of the North Chinese sedimentary basin up-to-700-km-wide. Being identical with the TL rift by orientation, morphology, and depth of initiation, the Eastern Amur rift formed also synchronously with the TL rift that corroborates opening of the latter via south-westward displacements of the NW sides of the BA system’s strike-slip faults. The established sinistral displacements of the NW sides for the faults belonging to both the diagonal and longitudinal systems to the south-westward (the total displacements’ sector is SW 205-250°) show dynamo-kinematic activity of the Asian continent in the processes of rifting of the Eastern margin of Asia

Physical and numerical simulation of the thermal and mechanical characteristics of stationary flows in the gasair paths of piston engines

Thermomechanical perfection of intake and exhaust systems largely determine the efficiency of the working process of reciprocating engines (ICE). The article presents the results of numerical simulation and experimental study of the heat transfer of gas flows in profiled gas- air systems of ICEs. A description of the numerical simulation technique, experimental setup, configurations of the studied hydraulic systems, measuring base and features of the experiments are given. On the basis of numerical modeling, it has been established that the use of profiled sections with cross sections in the shape of a square or a triangle in exhaust systems of an ICEs leads to a decrease in the heat transfer coefficient by 5-11%. It is shown that the use of similar profiled sections in the intake system of reciprocating engines also leads to a decrease in the heat transfer coefficient to 10 % at low air flow rates (up to 40 m/s) and an increase in the heat transfer coefficient to 7% at high speeds. Experimental studies qualitatively confirm the simulation results