The Two-fluid Description of a Mesoscopic Cylinder

Quantum coherence of electrons interacting via the magnetostatic coupling and confined to a mesoscopic cylinder is discussed. The electromagnetic response of a system is studied. It is shown that the electromagnetic kernel has finite low frequency limit what implies infinite conductivity. It means that part of the electrons is in a coherent state and the system can be in general described by a two-fluid model. The coherent behavior is determind by the interplay between finite size effects and the correlations coming from the magnetostatic interactions (the interaction is considered in the mean field approximation). The related persistent currents depend on the geometry of the Fermi Surface. If the Fermi Surface has some flat portions the self-sustaining currents can be obtained. The relation of the quantum coherent state in mesoscopic cylinders to other coherent phenomena is discussed.Comment: 21 pages, Latex, 4 figures, in print in Eur. Phys. J. B (Z. Phys. B

Orbital Magnetic Ordering in Disordered Mesoscopic Systems

We present some model calculations of persistent currents in disordered one- and two-dimensional mesoscopic systems. We use the tight-binding model and calculate numerically the currents in small systems for several values of disorder. Next we fit appropriate analytical formulae, and using them we find self- -sustaining currents and critical fields in larger, more realistic systems with different shapes of the Fermi surfaces.Comment: 16 pages, LaTeX, 8 figures, in print in J. Magn. Magn. Ma

Geodetic Measurement of Deformation East of the San Andreas Fault in Central California

Triangulation and trilateration data from two geodetic networks located between the western edge of the Great Valley and the San Andreas fault have been used to calculate shear strain rates in the Diablo Range and to estimate the slip rate along the Calaveras and Paicines faults in Central California. Within the Diablo Range the average shear strain rate was determined for the time period between 1962 and 1982 to be 0.15 + or - 0.08 microrad/yr, with the orientation of the most compressive strain at N 16 deg E + or - 14 deg. The orientation of the principal compressive strain predicted from the azimuth of the major structures in the region is N 25 deg E. It is inferred that the measured strain is due to compression across the folds of this area: the average shear straining corresponds to a relative shortening rate of 4.5 + or - 2.4 mm/yr. From an examination of wellbore breakout orientations and the azimuths of P-axes from earthquake focal mechanisms the inferred orientation of maximum compressive stress was found to be similar to the direction of maximum compressive strain implied by the trend of local fold structures. Results do not support the hypothesis of uniform fault-normal compression within the Coast Ranges. From trilateration measurements made between 1972 and 1987 on lines that are within 10 km of the San Andreas fault, a slip rate of 10 to 12 mm/yr was calculated for the Calaveras-Paicines fault south of Hollister. The slip rate of the Paicines fault decreases to 4 mm/yr near Bitter

Electromagnetic properties of mesoscopic cylinder

The electromagnetic response of a mesoscopic cylinder made of a normal metal or a semiconductor is studied. The relation between the induced current J(q, w) and the electric field E(q, w) is derived. It is shown that the kernel K(q, w) which determines the properties of the system has a finite limit which implies infinite conductivity. The mesoscopic cylinder by virtue of its topology and small dimensions can support a persistent current. If the coherence of currents from different channels is strong enough a novel effect — the self-sustaining current can be obtained. We show tlat a mesoscopic multichannel system exhibits some features which bear resemblance to the superconductor

Physicochemical properties and agglomeration parameters of biogas digestate with addition of calcium carbonate

ArticleThe aim of the work was to determine the physical properties of digestate from biogas production - either with or without the addition of calcium carbonate and to determine the parameters of its compaction. The material for research was obtained from an agricultural biogas plant specialized in processing cattle manure, vegetable pomace, chicken manure and maize silage. The parameters of compaction of digestate were experimentally determined and its net calorific value was calculated based on the gross calorific value. Physical properties were determined according to standards. The moisture content of liquid digestate was 96%. Mechanical separation allowed to decrease the water content by 19% and addition of 20% of calcium carbonate by 30%. It was found that digestate with addition of calcium carbonate is not suitable to use for energy purposes, because of its low net calorific value (5.2–5.9 MJ kg-1), however it can be used for fertilizer purposes in relation to its chemical composition. Without additives, the net calorific value was 14.9 MJ kg-1 , but due to the high moisture content of the raw material it is unprofitable to dry it and burn. On the other hand, it was proved that it is possible to obtain pellets of appropriate density out of the digestate using 40 mm of the die height and 0.3 g of single portion of the material

Coherent phenomena in mesoscopic systems

A mesoscopic system of cylindrical geometry made of a metal or a semiconductor is shown to exhibit features of a quantum coherent state. It is shown that magnetostatic interaction can play an important role in mesoscopic systems leading to an ordered ground state. The temperature $T^{*}$ below the system exhibits long-range order is determined. The self-consistent mean field approximation of the magnetostatic interaction is performed giving the effective Hamiltonian from which the self-sustaining currents can be obtained. The relation of quantum coherent state in mesoscopic cylinders to other coherent systems like superconductors is discussed.Comment: REVTeX, 4 figures, in print in Supercond. Sci. Techno

Wzorzec stratności dielektrycznej przy niskich częstotliwościach

Wzorcowanie mierników pojemności elektrycznej C i współczynnika tg delta, stosowanych do pomiarów przenikalności elektrycznej i współczynnika stratności dielektrycznej, jest utrudnione przez brak odpowiednio dokładnych wzorców tg d. Wzorce tg d realizuje się poprzez szeregowe połączenie kondensatora z rezystorem o znanej wartości. Zasadniczą przyczyną niedokładności takiego wzorca są głównie parametry resztkowe rezystora. Opisany w tym artykule wzorzec tgd przy 50 Hz ma zakres pomiarowy (0,1÷10)×10-4 i niepewność wartości 10-5.============.Calibration of electric capacitance C and the tgd factor of meters, used for permittivity and dielectric dissipation factor tgd measurements, is difficult as there is no adequately accurate tgd standards. Dielectric dissipation factor standards are made of series connection of known value capacitor and resistor. Main reason of inaccuracy this type of standard are mainly residual parameters of resistor. The standard tgd described in this paper has at 50 Hz the range (0.1÷10)×10-4 and uncertainty of value 10-5

Possibility of long-range order in clean mesoscopic cylinders

A microscopic Hamiltonian of the magnetostatic interaction is discussed. This long-range interaction can play an important role in mesoscopic systems leading to an ordered ground state. The self-consistent mean field approximation of the magnetostatic interaction is performed to give an effective Hamiltonian from which the spontaneous, self-sustaining currents can be obtained. To go beyond the mean field approximation the mean square fluctuation of the total momentum is calculated and its influence on self-sustaining currents in mesoscopic cylinders with quasi-1D and quasi-2D conduction is considered. Then, by the use of the microscopic Hamiltonian of the magnetostatic interaction for a set of stacked rings, the problem of long-range order is discussed. The temperature $T^{*}$ below which the system is in an ordered state is determined.Comment: 14 pages, REVTeX, 5 figures, in print in Phys. Rev.

Vacuum annealing phenomena in ultrathin TiDy/Pd bi-layer films evaporated on Si(100) as studied by TEM and XPS

Using a combination of TEM and XPS, we made an analysis of the complex high-temperature annealing effect on ultrathin titanium deuteride (TiDy) films evaporated on a Si(100) substrate and covered by an ultrathin palladium layer. Both the preparation and annealing of the TiDy/Pd bi-layer films were performed in situ under UHV conditions. It was found that the surface and bulk morphology of the bi-layer film as well as that of the Si substrate material undergo a microstructural and chemical conversion after annealing and annealing-induced deuterium evolution from the TiDy phase. Energy-filtered TEM (EFTEM) mapping of cross-section images and argon ion sputter depth profiling XPS analysis revealed both a broad intermixing between the Ti and Pd layers and an extensive inter-diffusion of Si from the substrate into the film bulk area. Segregation of Ti at the Pd top layer surface was found to occur by means of angle-resolved XPS (ARXPS) and the EFTEM analyses. Selected area diffraction (SAD) and XPS provided evidence for the formation of a new PdTi2 bimetallic phase within the top region of the annealed film. Moreover, these techniques allowed to detect the initial stages of TiSi phase formation within the film–substrate interlayer