On the structure of stationary sets

We isolate several classes of stationary sets of [k]ωand investigate implications among them. Under a large cardinal assumption, we prove a structure theorem for stationary sets.     

Revised PROMETHEE algorithm with reference values

Central European Journal of Operations Research - PROMETHEE method is a very popular quantitative method of decision-making with many benefits. However, the evaluation of alternatives in the...     

Iron-modified zeolite BETA: efficient catalyst in methyllaurate, 2-hexyl-1,3-dioxolane, 4-methyl-2-propyltetrahydro-2H-pyran-4-ol and 4-methyl-2-phenyl-tetrahydro-2H-pyran-4-ol synthesis

Research on Chemical Intermediates - Several types of modified zeolite BETA38 with different iron loading were prepared. Prepared materials were characterized using different techniques (XRD, XRF,...     

Effective semi-analytic integration for hypersingular Galerkin boundary integral equations for the Helmholtz equation in 3D

We deal with the Galerkin discretization of the boundary integral equations corresponding to problems with the Helmholtz equation in 3D. Our main result is the semi-analytic integration for the bilinear form induced by the hypersingular operator. Such computations have already been proposed for the bilinear forms induced by the single-layer and the double-layer potential operators in the monograph The Fast Solution of Boundary Integral Equations by O. Steinbach and S. Rjasanow and we base our computations on these results.     

A new proof of Kunen's inconsistency

Using a basic fact from Shelah's theory of possible cofinalities, we give a new proof of Kunen's inconsistency theorem: there is no nontrivial elementary embedding of the set-theoretical universe into itself.

     

Dehydration of synthetic lepidocrocite (γ-FeOOH)

The thermal decomposition of synthetic lepidocrocite,γ-FeOOH, was studied using DTA, infrared and Mössbauer spectroscopy and X-ray diffraction, and the dependence of the phase composition of the dehydration products on the method of preparing the initialγ-FeOOH was described. The results demonstrated thatγ-Fe₂O₃ formed by dehydration ofγ-FeOOH consists of very small particles with a broad size distribution and that, depending on the method of preparation, the initialγ-FeOOH can contain a large amount of amorphous ferric hydroxide. A preparation method yieldingγ -FeOOH which is not contaminated with other ferric oxide-hydroxides is recommended.     

A boundary element method for homogenization of periodic structures

Homogenized coefficients of periodic structures are calculated via an auxiliary partial differential equation in the periodic cell. Typically, a volume finite element discretization is employed for the numerical solution. In this paper, we reformulate the problem as a boundary integral equation using Steklov–Poincaré operators. The resulting boundary element method only discretizes the boundary of the periodic cell and the interface between the materials within the cell. We prove that the homogenized coefficients converge super-linearly with the mesh size, and we support the theory with examples in two and three dimensions.     

Formation and Crystallization of FeIII Hydroxides. Effects of precipitation temperature and the nature of starting FeIII salt on the properties of FeIII hydroxides prepared in weakly acidic medium

Amorphous Fe^III hydroxides prepared at pH = 6 differ from analogous precipitates obtained in alkaline media in that they have an increased content of anions bound in their structures, and crystallize less readily both in dry thermal treatment and under hydrothermal conditions. The shapes of DTA curves obtained for freshly prepared gels and for products of ageing in mother liquor are discussed, and the effect of the anions present on the course of thermal decomposition is assessed.     

Proper forcing and rectangular ramsey theorems

I prove forcing preservation theorems for products of definable partial orders preserving cofinality of the meager or null ideal. Rectangular Ramsey theorems for the related ideals follow from the proofs. Partially supported by grant GA ČR 201-03-0933, NSF grants DMS 0071437 and DMS 0300201, and a visiting appointment at CRM, Universitat Autònoma de Barcelona.     

Measurements of natural and artificial radionuclides in food samples and water for human consumption in Austria for the calculation of the ingestion dose

A new report on food habits of the Austrian population in the year 2006/2007 was released in 2008. Mixed diets and foodstuffs are measured within a monitoring program according to the Austrian radiation protection law, food law, and the Commission Recommendation 2000/473/Euratom on the application of Article 36 of the Euratom Treaty concerning the monitoring of the levels of radioactivity in the environment for the purpose of assessing the exposure of the population as a whole. In addition, drinking and mineral water samples are measured for natural and artificial radionuclides. The ingestion dose for the Austrian population is recalculated based on the results of these measurements, literature data, and the data of the new report on food habits. In general, the major part of the ingestion dose is caused by natural radionuclides, especially ⁴⁰K.