Linear Amplifier Breakdown and Concentration Properties of a Gaussian Field Given that its L2\bm{L^2}-Norm is Large

In the context of linear amplification for systems driven by the square of a Gaussian noise, we investigate the realizations of a Gaussian field in the limit where its $L^2$-norm is large. Concentration onto the eigenspace associated with the largest eigenvalue of the covariance of the field is proved. When the covariance is trace class, the concentration is in probability for the $L^2$-norm. A stronger concentration, in mean for the sup-norm, is proved for a smaller class of Gaussian fields, and an example of a field belonging to that class is given. A possible connection with Bose-Einstein condensation is briefly discussed.Comment: REVTeX file, 11 pages, 1 added paragraph in the introduction, 2 added references, minor modifications in the text and abstract, submitted to J. Stat. Phy

A Soluble Phase Field Model

The kinetics of an initially undercooled solid-liquid melt is studied by means of a generalized Phase Field model, which describes the dynamics of an ordering non-conserved field phi (e.g. solid-liquid order parameter) coupled to a conserved field (e.g. thermal field). After obtaining the rules governing the evolution process, by means of analytical arguments, we present a discussion of the asymptotic time-dependent solutions. The full solutions of the exact self-consistent equations for the model are also obtained and compared with computer simulation results. In addition, in order to check the validity of the present model we confronted its predictions against those of the standard Phase field model and found reasonable agreement. Interestingly, we find that the system relaxes towards a mixed phase, depending on the average value of the conserved field, i.e. on the initial condition. Such a phase is characterized by large fluctuations of the phi field.Comment: 13 pages, 8 figures, RevTeX 3.1, submitted to Physical Review

Rate-equation calculations of the current flow through two-site molecular device and DNA-based junction

Here we present the calculations of incoherent current flowing through the two-site molecular device as well as the DNA-based junction within the rate-equation approach. Few interesting phenomena are discussed in detail. Structural asymmetry of two-site molecule results in rectification effect, which can be neutralized by asymmetric voltage drop at the molecule-metal contacts due to coupling asymmetry. The results received for poly(dG)-poly(dC) DNA molecule reveal the coupling- and temperature-independent saturation effect of the current at high voltages, where for short chains we establish the inverse square distance dependence. Besides, we document the shift of the conductance peak in the direction to higher voltages due to the temperature decrease.Comment: 12 pages, 6 figure

Conceptual design of a winged hybrid airship

The present study focuses on the sizing and aerodynamic contour design of a two-seater 1000 kg gross take-off mass winged hybrid airship. Unlike the conventional hybrid airships, which stay aloft and takeoff with the help of VTOL propulsion systems, a winged hybrid airship requires a certain speed to takeoff by utilizing lift coming from its aerodynamic surfaces. Heaviness fraction and takeoff ground roll are considered as measure of merit in initial sizing. Based on the design requirement of Malaysian inter-island tourism and transportation of agricultural products, range is set to 450 km and ground roll for take-off about 150 m. For the airship to be heavy enough for ground handling, the ratio of hydrostatic to hydrodynamic lift is set equal to 49:51. Summary of the results to be obtained in early design phase will give a baseline start to study the aerodynamics and stability characteristics of such airships in future

Systemoptimierung der Infrastruktur von Steinkohlenbergwerken Abschlussbericht

SIGLEAvailable from TIB Hannover: F95B923+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Informationen zum Messplatz fuer Roentgen-Topographie mit Synchrotronstrahlung am HASYLAB/DESY (Hamburg)

TIB: D.Dt.F./AC 1000 (18,30) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman