Technical paper on Twin screw extruder processing technology for fibres as raw material for peat substitution

One important aim of the Organic-PLUS project is to develop resource and energy efficient technologies to produce fibres from lignocellulosic plant materials as a raw material to substitute peat. For this purpose, Leibniz Institute für Agrartechnik und Bioekonomie (ATB), Germany leads the work in the task 5.3, “Processing of agroforestry and other plant material for improved characteristics”. This report (Project deliverable D5.3) describes one technology available at pilot scale at ATB which changes the characteristics of plant fibres to make them better suited for peat replacement. The process is called extrusion, and is described in this report. The purpose is to inform stakeholders interested in peat replacement, including scientists involved in the Organic-PLUS project, to collect relevant materials for extrusion and to test further utilisations of extruded fibres

Spectral dependence of the Kapitza resistance between O,5 K and 2,3 K

Summarizing, we observed strongly enhanced phonon transport from a real solid into 4 He starting at about 85 GHz which is independent of the He gas pressure up to liquid helium. With the isotope 3 He the onset frequency for enhanced phonon transport shifts to 100 GHz. The threshold frequencies are almost independent of the He temperature in the range between 0.5 K and 2.3 K. Only slight shifts to lower frequencies with decreasing He temperature have been observed. No significant influence of the generator material (Sn, Al, SiO) or the generator preparation on the onset frequency has been observed. Moreover at low temperatures and thin He films we observed an additional structure which might be interpreted as film thickness resonances in the He film layer on the generator

Path integral solution for an angle-dependent anharmonic oscillator

We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making an adequate change of time we were able to separate the angular motion from the radial one. The relative propagator is then exactly calculated. The energy spectrum and the corresponding wave functions are obtained.Comment: Corrected typos and mistakes, To appear in Communications in Theoretical Physic

Driving-Induced Symmetry Breaking in the Spin-Boson System

A symmetric dissipative two-state system is asymptotically completely delocalized independent of the initial state. We show that driving-induced localization at long times can take place when both the bias and tunneling coupling energy are harmonically modulated. Dynamical symmetry breaking on average occurs when the driving frequencies are odd multiples of some reference frequency. This effect is universal, as it is independent of the dissipative mechanism. Possible candidates for an experimental observation are flux tunneling in the variable barrier rf SQUID and magnetization tunneling in magnetic molecular clusters.Comment: 4 pages, 4 figures, to be published in PR