Solid electrolyte cell

A solid electrolyte cell including a body of solid ionized gas-conductive electrolyte having mutually spaced surfaces and on which is deposited a multiplicity of mutually spaced electrodes is described. Strips and of bare substances are interposed between electrodes, so that currents of ionic gas may be established between the electrodes via the bare strips, whereby electrical resistance for the cells is lowered and the gas conductivity is enhanced

Basic investigation into the electrical performance of solid electrolyte membranes

The electrical performance of solid electrolyte membranes was investigated analytically and the results were compared with experimental data. It is concluded that in devices that are used for pumping oxygen the major power losses have to be attributed to the thin film electrodes. Relations were developed by which the effectiveness of tubular solid electrolyte membranes can be determined and the optimum length evaluated. The observed failure of solid electrolyte tube membranes in very localized areas is explained by the highly non-uniform current distribution in the membranes. The analysis points to a possible contact resistance between the electrodes and the solid electrolyte material. This possible contact resistance remains to be investigated experimentally. It is concluded that film electrodes are not appropriate for devices which operate with current flow, i.e., pumps though they can be employed without reservation in devices that measure oxygen pressures if a limited increase in the response time can be tolerated

Apparent operating limits of arc heaters with respect to total enthalpy and stagnation pressure

Operational limitations of arc heaters caused by enthalpic stagnation pressure

Antenna dimensions of synthetic aperture radar systems on satellites

Design of a synthetic aperture radar (SAR) for a satellite must take into account the limitation in weight and dimensions of the antenna. The lower limits of the antenna area are derived from the conditions of unambiguity of the SAR system. This result is applied to estimate the antenna requirements for SARs on satellites in circular orbits of various altitudes around Earth and Venus

Low pressure arc electrode

Reducing the pressure in the vicinity of the arc attachment point by allowing the gas to flow through a supersonic nozzle minimizes local heating rates, prevents ablation, and increases the efficiency of coaxial gas-flow arcs

Recursion method and one-hole spectral function of the Majumdar-Ghosh model

We consider the application of the recursion method to the calculation of one-particle Green's functions for strongly correlated systems and propose a new way how to extract the information about the infinite system from the exact diagonalisation of small clusters. Comparing the results for several cluster sizes allows us to establish those Lanczos coefficients that are not affected by the finite size effects and provide the information about the Green's function of the macroscopic system. The analysis of this 'bulk-related' subset of coefficients supplemented by alternative analytic approaches allows to infer their asymptotic behaviour and to propose an approximate analytical form for the 'terminator' of the Green's function continued fraction expansion for the infinite system. As a result, the Green's function acquires the branch cut singularity corresponding to the incoherent part of the spectrum. The method is applied to the spectral function of one-hole in the Majumdar-Ghosh model (the one-dimensional $t-J-J^{\prime}$ model at $J^{\prime}/J=1/2$). For this model, the branch cut starts at finite energy $\omega_0$, but there is no upper bound of the spectrum, corresponding to a linear increase of the recursion coefficients. Further characteristics of the spectral function are band gaps in the middle of the band and bound states below $\omega_0$ or within the gaps. The band gaps arise due to the period doubling of the unit cell and show up as characteristic oscillations of the recursion coefficients on top of the linear increase.Comment: 12 pages, 7 figure