Influence of sintering temperature and aging on properties of cermet Ni/8YSZ materials obtained by citric method

The anode supported cell for solid oxide fuel cell, as a modification of the traditional Ni-YSZ anode supported on electrolyte, is examined in this work. The materials obtained on the base of citric method are presented and investigated in this work. The materials consisted of 40 wt.% Ni/YSZ, 50 wt.% Ni/YSZ and 60 wt.% Ni/YSZ were obtained. The base Ni/YSZ materials are tested on the two ways: (a) aging tests and (b) sintering tests. All the materials after aging and sintering are tested by the impedance spectroscopy. The results of electrical conductivity for samples before and after aging show that only in the case of 40 wt.% Ni/YSZ, sample loses of metallic conductivity after 500 h of heating. The other samples reveal metallic conductivity even after long period of aging. The tests of sintering temperature show that this process does not affect significantly on electrical conductivity of the materials.     

Plasmonic enhancement of blue emission from ZnO nanorods grown on the anodic aluminum oxide (AAO) template

Luminescent properties of ZnO nanorods covered with Ag nanoparticles are examined. Nanorods were synthesized on AAO templates using Atomic Layer Deposition (ALD) technique. Two types of the samples were prepared with different arrangement of ZnO nanorods and doping conditions. Nanorods of the second type were codoped with Al, to stimulate defect-related emissions. The ZnO material fills heterogeneously the interior of the AAO nanopores and has hexagonal, wurtzite structure. Both types of structures exhibit a broad defect-related emission at about 440 nm, most probably related to recombination at zinc interstitial (Zn_i) defects. This emission in samples with a random distribution of ZnO:Al nanorods and finer Ag nanoparticles is enhanced by factor of ～2.5 upon Ag deposition. The so-obtained material is interesting from the point of view of its application in blue range emitting diodes.     

MCSCF calculation of response properties of Argon

Summary Analytic equations of the multiconfigurational SCF (MCSCF) response theory are combined with the finite-field (FF) approach to compute static and frequency dependent electric and magnetic properties of the Argon atom. A complete active space (CAS SCF) function including the 3s, 3p, 3d, 4s and 4p orbitals in the active space and a large (17s 13p 7d 5f 3g) basis set are employed. This permits an accurate determination of various linear and non-linear response properties such as e.g. electric dipole polarisability and second hyperpolarisability, Verdet constant, magnetisability and second hyperpolarisability. The results, both for the static values and for the frequency dependence of these properties, compare well with other most recent experimental and theoretical data.Dedicated to Jan Linderberg on the occasion of his 60th birthday     

Towards Martins minimum

We show that it is consistent with MA + ?CH that the Forcing Axiom fails for all forcing notions in the class of ω^ω–bounding forcing notions with norms of [17]. Received: 28 April 1999 / Published online: 12 December 2001     

Exotic smoothness,noncommutative geometry,and particle physics

We investigate how exotic differential structures may reveal themselves in particle physics. The analysis is based on A. Connes' construction of the standard model. It is shown that, if one of the copies of the spacetime manifold is equipped with an exotic differential structure, a compact object of geometric origin may exist even if the spacetime is topologically trivial. Possible implications are discussed. AnSU(3) ⊗SU(2) ⊗U(1) gauge model is constructed. This model may not be realistic, but it shows what kind of physical phenomena might be expected due to the existence of exotic differential structures on the spacetime manifold.     

Electrospray ionization mass spectrometric study of 1,3,4-oxadiazole–copper complexes

The complexes of 2,5-disubstituted-1,3,4-oxadiazoles, namely 2,5-diphenyl-1,3,4-oxadiazole (1), 2,5-bis(2-pyridyl)-1,3,4-oxadiazole (2) and 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (3), with copper cation were studied by electrospray ionization mass spectrometry (ESI-MS). The ability of the compounds studied to form complexes with copper (under the ESI conditions) can be ordered as 2 > 1 > 3. The compounds studied tend to form both 1 : 1 and 2 : 1 chelate complexes with both copper(II) and copper(I). The complexes with copper(I) are formed in the ESI process. The influence of solvent polarity, solution flow-rate, counter ions (Cl⁻, NO₃⁻, CH₃COO⁻, SO₄²⁻, acetylacetonates) on the type of the ions observed was studied. Copyright © 2004 John Wiley & Sons, Ltd.     

Computational experience with a bundle approach for semidefinite cutting plane relaxations of Max-Cut and Equipartition

We propose a dynamic version of the bundle method to get approximate solutions to semidefinite programs with a nearly arbitrary number of linear inequalities. Our approach is based on Lagrangian duality, where the inequalities are dualized, and only a basic set of constraints is maintained explicitly. This leads to function evaluations requiring to solve a relatively simple semidefinite program. Our approach provides accurate solutions to semidefinite relaxations of the Max-Cut and the Equipartition problem, which are not achievable by direct approaches based only on interior-point methods. Received: April, 2004 The last author gratefully acknowledges the support from the Austrian Science Foundation FWF Project P12660-MAT.     

Lifetimes and side-feeding population of the yrast band levels in 131La

Lifetimes of yrast levels with spins I^π = 23/2^--43/2^- in ¹³¹La populated in the ¹²²Sn(¹⁴N, 5n) reaction at a beam energy of 70MeV are measured by the Doppler Shift Attenuation method. A model of side-feeding population is presented. The model parameters are determined in an experiment based on the lineshape of γ-transitions from two highest spin levels and from the intensity distribution along the yrast band. The properties of the h_11/2 band in ¹³¹La are compared with the theoretical predictions obtained in the framework of the Core-Quasi-Particle Coupling and the self-consistent Total Routhian Surface models.     

Sheaves of Einstein algebras

To include all types of singularities into a geometrically tractable theoretical scheme we change from Einstein algebras, an algebraic generalization of general relativity, to sheaves of Einstein algebras. The theory of such spaces, called Einstein structured spaces, is developed. Both quasiregular and curvature singularities are studied in some detail. Examples of the closed Friedmann world model and the Schwarzschild spacetime show that Schmidt'sb-boundary is a useful theoretical tool when considered in the category of structured spaces.