On the determination of the thermal diffusion factor from column measurements

A new method for experimental determination of the thermal diffusion factor _T for binary gas mixtures with a thermal diffusion column (TDC) is developed, based on A. M. Rozen's equation of TDC. The experimental results for _T are obtained in a reduced form in this approximation. An experimental reference point, determined in the same TDC with a standard gas mixture, is used for the transformation of the results for _T in absolute units. The proposed method is applicable for arbitrary gas mixtures, irrespective of the mass difference of the components.     

Electronic conductivity of the (+)aluminum/complex anodic film/electrolyte system

The electronic conductivity, i.e. the leakage current of aluminum electrolytic capacitors having as a dielectric a complex anodic film with a defined thickness of the barrier sublayer is measured. The complex films are obtained by re-anodization in a non-dissolving electrolyte of porous alumina films formed in H₂SO₄ and in (COOH)₂. Analogous investigations with barrier-type anodic films are carried out for comparison. It is found that in all cases the empirical dependence of the electronic current on field strength, J_e=_e exp(_eE^1/2), is valid for the investigated system. The constants _e, and _e are determined experimentally. Calculations based on the theory are performed to obtain theoretical values of the constant _e, and they are compared with the experimental values. A satisfactory coincidence is obtained between the experimental data and those calculated on the base of the theory. Capacitors with complex films having different porous matrices are studied. The capacitors with a porous matrix formed in oxalic acid show a lower leakage current than those with a matrix formed in sulfuric acid.     

Proximity Effect in Bulk LaBa2Cu3O7?y Samples with Ag Additions

Bulk LaBa ₂ Cu ₃ O _(7–y) samples with different Ag additions were investigated. It was shown that Ag does not enter the crystallographic structure of the superconductor and segregates on the grain boundary region. Current path in these samples occurs through the proximity-connected grains, and this was confirmed from the temperature dependence of the critical current density and mutual inductance. By using the theory developed for the thin-film structures, we conclude that growing of the Ag content increased the effective cross-section and the normal metal thickness. The effective cross-section prevails at low concentration, increasing the current. The normal metal thickness dominates at higher concentration, leading to saturation or even lowering of the critical current.     

Influence of the active zone diameter, on the UV-ion Ne-CuBr laserperformance

An active-zone-diameter scanning of an ultraviolet (UV) Cu⁺ laser excited in a nanosecond, pulsed longitudinal Ne-CuBr discharge with an excitation pulse repetition frequency of 19.5-25 kHz is carried out. The discharge conditions for achieving a maximum average output power on the UV lines-248.6, 252.9, 260.0, and 270.3 nm are found for each active zone diameter. A record average output power of 1.3 W is obtained for multiline operation. The specific average output power is 57 mW/cm³ at an active volume of 23 cm³. The highest peak pulse power and average laser power on the 248.6-nm laser line for the UV Cu⁺ lasers are also measured-3.25 and 0.85 W, respectively. A simplified kinetic model, which describes the discharge afterglow processes, is made     

An ultra-low energy (30-200 eV) ion-atomic beam source for ion-beam-assisted deposition in ultrahigh vacuum

The paper describes the design and construction of an ion-atomic beam source with an optimized generation of ions for ion-beam-assisted deposition under ultrahigh vacuum (UHV) conditions. The source combines an effusion cell and an electron impact ion source and produces ion beams with ultra-low energies in the range from 30 eV to 200 eV. Decreasing ion beam energy to hyperthermal values (≈10(1) eV) without loosing optimum ionization conditions has been mainly achieved by the incorporation of an ionization chamber with a grid transparent enough for electron and ion beams. In this way the energy and current density of nitrogen ion beams in the order of 10(1) eV and 10(1) nA/cm(2), respectively, have been achieved. The source is capable of growing ultrathin layers or nanostructures at ultra-low energies with a growth rate of several MLs/h. The ion-atomic beam source will be preferentially applied for the synthesis of GaN under UHV conditions.     

Proximity Effect in Bulk LaBa2Cu3O7−y Samples with Ag Additions

Bulk LaBa ₂ Cu ₃ O _(7?y) samples with different Ag additions were investigated. It was shown that Ag does not enter the crystallographic structure of the superconductor and segregates on the grain boundary region. Current path in these samples occurs through the proximity-connected grains, and this was confirmed from the temperature dependence of the critical current density and mutual inductance. By using the theory developed for the thin-film structures, we conclude that growing of the Ag content increased the effective cross-section and the normal metal thickness. The effective cross-section prevails at low concentration, increasing the current. The normal metal thickness dominates at higher concentration, leading to saturation or even lowering of the critical current.     

Computing behavior of finite fuzzy machines – Algorithm and its application to reduction and minimization

We define finite fuzzy machines and investigate their behavior. Algorithm and software are proposed for computing behavior, for establishing equivalence and redundancy of states and for solving reduction and minimization problems. Computational complexity of the algorithm is discussed. Testing examples are supplied. The results are valid for finite max–min, min–max and max–product fuzzy machines.     

Formation of complex anodic films on porous alumina matrices

The kinetics of growth of complex anodic alumina films was investigated. These films were formed by filling porous oxide films (matrices) having deep pores. The porous films (matrices) were obtained voltastatically in (COOH)₂ aqueous solution under various voltages. The filling was done by reanodization in an electrolyte solution not dissolving the film. Data about the kinetics of reanodization depending on the porosity of the matrices were obtained. On the other hand, the slopes of the kinetic curves during re-anodization were calculated by two equations expressing the dependence of these slopes on the ionic current density. A discrepancy was ascertained between the values of the calculated slopes and those experimentally found. For this discrepancy a possible explanation is proposed, related to the temperature increase in the film, because of that the real current density significantly increases during re-anodization.