Mixed convection in a rotating porous cavity having local heater

Numerical simulation of convective heat transfer inside a rotating porous square cavity with local heater of constant temperature has been performed. Governing equations formulated on the basis of mass, momentum and energy conservation laws written using the dimensionless stream function, vorticity and temperature have been solved by the finite difference method. The effects of Rayleigh and Taylor numbers on periodic flow and heat transfer have been studied

Supramolecular organization of the human N-BAR domain in shaping the sarcolemma membrane

This is the final version of the article. Available from Elsevier via the DOI in this record.The 30 kDa N-BAR domain of the human Bin1 protein is essential for the generation of skeletal muscle T-tubules. By electron cryo-microscopy and electron cryo-tomography with a direct electron detector, we found that Bin1-N-BAR domains assemble into scaffolds of low long-range order that form flexible membrane tubules. The diameter of the tubules closely matches the curved shape of the N-BAR domain, which depends on the composition of the target membrane. These insights are fundamental to our understanding of T-tubule formation and function in human skeletal muscle.This work was supported by grants from the Deutsche Forschungsgemeinschaft (GRK 1026, SFB610) (A.A., T.G., J.B.), the BMBF ZIK program (A.M., J.B.), the European Regional Development Fund of the European Commission (A.M., T.G.: EFRE 1241 12 0001), and the state Sachsen-Anhalt (A.M., T.G., J.B.)

Thermal diffusion of supersonic solitons in an anharmonic chain of atoms

We study the non-equilibrium diffusion dynamics of supersonic lattice solitons in a classical chain of atoms with nearest-neighbor interactions coupled to a heat bath. As a specific example we choose an interaction with cubic anharmonicity. The coupling between the system and a thermal bath with a given temperature is made by adding noise, delta-correlated in time and space, and damping to the set of discrete equations of motion. Working in the continuum limit and changing to the sound velocity frame we derive a Korteweg-de Vries equation with noise and damping. We apply a collective coordinate approach which yields two stochastic ODEs which are solved approximately by a perturbation analysis. This finally yields analytical expressions for the variances of the soliton position and velocity. We perform Langevin dynamics simulations for the original discrete system which fully confirm the predictions of our analytical calculations, namely noise-induced superdiffusive behavior which scales with the temperature and depends strongly on the initial soliton velocity. A normal diffusion behavior is observed for very low-energy solitons where the noise-induced phonons also make a significant contribution to the soliton diffusion.Comment: Submitted to PRE. Changes made: New simulations with a different method of soliton detection. The results and conclusions are not different from previous version. New appendixes containing information about the system energy and soliton profile

Flexible In-Ga-Zn-O based circuits with two and three metal layers: simulation and fabrication study

The quest for high-performance flexible circuits call for scaling of the minimum feature size in Thin-Film Transistors (TFTs). Although reduced channel lengths can guarantee an improvement in the electrical properties of the devices, proper design rules also play a crucial role to minimize parasitics when designing fast circuits. In this letter, systematic Computer-Aided Design (CAD) simulations have guided the fabrication of highperformance flexible operational amplifiers (opamps) and logic circuits based on Indium-Gallium-Zinc-Oxide (IGZO) TFTs. In particular, the performance improvements due to the use of an additional third metal layer for the interconnections has been estimated for the first time. Encouraged by the simulated enhancements resulting by the decreased parasitic resistances and capacitances, both TFTs and circuits have been realized on a free-standing 50μm thick polymide foil using three metal layers. Despite the thicker layer stack, the TFTs have shown mechanical stability down to 5mm bending radii. Moreover, the opamps and the logic circuits have yielded improved electrical performance with respect to the architecture with two metal layers: gainbandwidth- product (GBWP) increased by 16:9%, for the first one, and propagation delay (tpd) decreased by 43%, for the latter one

Numerical electrokinetics

A new lattice method is presented in order to efficiently solve the electrokinetic equations, which describe the structure and dynamics of the charge cloud and the flow field surrounding a single charged colloidal sphere, or a fixed array of such objects. We focus on calculating the electrophoretic mobility in the limit of small driving field, and systematically linearise the equations with respect to the latter. This gives rise to several subproblems, each of which is solved by a specialised numerical algorithm. For the total problem we combine these solvers in an iterative procedure. Applying this method, we study the effect of the screening mechanism (salt screening vs. counterion screening) on the electrophoretic mobility, and find a weak non-trivial dependence, as expected from scaling theory. Furthermore, we find that the orientation of the charge cloud (i. e. its dipole moment) depends on the value of the colloid charge, as a result of a competition between electrostatic and hydrodynamic effects.Comment: accepted for publication in Journal of Physics Condensed Matter (proceedings of the 2012 CODEF conference

Radio frequency electronics on plastic

In this paper the recent progress of active high frequency electronics on plastic is discussed. This technology is mechanically flexible, bendable, stretchable and does not need any rigid chips. Indium Gallium Zinc Oxide (IGZO) technology is applied. At 2 V supply and gate length of 0.5 μm, the thin-film transistors (TFTs) yield a measured transit frequency of 138 MHz. Our scalable TFT compact simulation model shows good agreement with measurements. To achieve a sufficiently high yield, TFTs with gate lengths of around 5 μm are used for the circuit design. A Cherry Hopper amplifier with 3.5 MHz bandwidth, 10 dB gain and 5 mW dc power is presented. The fully integrated receiver covering a plastic foil area of 3 × 9 mm2 includes a four stage cascode amplifier, an amplitude detector, a baseband amplifier and a filter. At a dc current of 7.2 mA and a supply of 5 V, a bandwidth of 2 - 20 MHz and a gain beyond 15 dB were measured. Finally, an outlook regarding future advancements of high frequency electronics on plastic is given

Atropselective syntheses of (-) and (+) rugulotrosin A utilizing point-to-axial chirality transfer

Chiral, dimeric natural products containing complex structures and interesting biological properties have inspired chemists and biologists for decades. A seven-step total synthesis of the axially chiral, dimeric tetrahydroxanthone natural product rugulotrosin A is described. The synthesis employs a one-pot Suzuki coupling/dimerization to generate the requisite 2,2'-biaryl linkage. Highly selective point-to-axial chirality transfer was achieved using palladium catalysis with achiral phosphine ligands. Single X-ray crystal diffraction data were obtained to confirm both the atropisomeric configuration and absolute stereochemistry of rugulotrosin A. Computational studies are described to rationalize the atropselectivity observed in the key dimerization step. Comparison of the crude fungal extract with synthetic rugulotrosin A and its atropisomer verified that nature generates a single atropisomer of the natural product.P50 GM067041 - NIGMS NIH HHS; R01 GM099920 - NIGMS NIH HHS; GM-067041 - NIGMS NIH HHS; GM-099920 - NIGMS NIH HH

ifo Konjunkturprognose 2007/2008: Aufschwung mit niedrigerem Tempo

Die Weltwirtschaft befindet sich im vierten Jahr eines konjunkturellen Aufschwungs und expandierte auch im Frühjahr 2007 kräftig. Das Bruttoinlandsprodukt legte infolge der günstigen Ertragslage der Unternehmen, höherer Aktienkurse und der zwar zuletzt gestiegenen, aber immer noch vergleichsweise niedrigen langfristigen Zinsen dynamisch zu. Und auch im Prognosezeitraum wird die Expansion der Weltwirtschaft schwungvoll bleiben, sich jedoch etwas abflachen. In der Eurozone setzt sich der Aufschwung zunächst schwungvoll fort, verliert aber im nächsten Jahr etwas an Dynamik. In den Industrieländern wird das Bruttoinlandsprodukt im Jahr 2007 um 2,5% und im Jahr 2008 um 2,8% zunehmen. Der Welthandel wird in diesem Jahr um 7,5% und im nächsten Jahr um 8,0% expandieren. In Deutschland hat sich der Aufschwung nach der Jahreswende trotz der Erhöhung der Mehrwertsteuer fortgesetzt. Saisonbereinigt ist die gesamtwirtschaftliche Produktion im ersten Quartal mit einer laufenden Jahresrate von 2,1% gestiegen, zuvor hatte das Expansionstempo allerdings noch bei 4,0% gelegen. Im Prognosezeitraum dürfte sich der konjunkturelle Aufschwung fortsetzen, dabei aber nicht mehr die hohe Dynamik des vergangenen Jahres erreichen. Die gesamtwirtschaftliche Produktion wird im laufenden Jahr um 2,6% expandieren; arbeitstäglich bereinigt um 2,8%. Im Jahr 2008 tritt der konjunkturelle Aufschwung in seine Spätphase ein.Weltkonjunktur, Konjunkturprognose, Wirtschaftslage, Wirtschaftswachstum, Deutschland, Welt