The airborne natural radioactivity in the uranium mine Rožná I

The knowledge of the behaviour of radioactive aerosol particles in the uranium mine atmosphere is very important due to the evaluation of the effective dose for uranium miners. During the research of the project SUJ200402-'Study of behaviour of natural long-lived radionuclides in the mine atmosphere', several measurement campaigns were performed in the last active Central Europe uranium mine Rozna I. The main purpose of this paper is characterisation the radionuclides which creating the main part of the airborne radioactivity in the uranium mine atmosphere. The present paper introduces results of the measurements of airborne radioactivity in stopes of the uranium mine Rozna I. The measurements were performed at the 21st floor at a depth of ～1100 m under the ground. In addition to the concentration of (222)Rn, its progenies, long-lived radionuclides and also the concentration of aerosol particles were measured.     

Investigating the physics of disruptions with real-time tomography at JET

As JET is developing and testing operational scenarios for higher fusion performance, an increase in pulse disruptivity is being observed. On a deeper analysis, we find that several radiative phenomena play an active role in determining the outcome of the pulse. The analysis is enabled by the use of real-time tomography based on the bolometer diagnostic. Even though plasma tomography is an inverse problem, we use machine learning to train a forward model that provides the radiation profile directly, based on a single matrix multiplication step. This model is used to investigate radiative phenomena including sawtooth crashes, ELMs and MARFE, and their relationship to the radiated power in different regions of interest. In particular, we use real-time tomography to monitor the core region, and to throw an alarm whenever core radiation exceeds a certain threshold. Our results suggest that this measure alone can anticipate a significant fraction of disruptions in the JET baseline scenario.     

Simulation of containment thermal-hydraulics in the Marviken Blowdown 16 experiment with ASTEC and CONTAIN codes

The boiling heavy water reactor Blowdown 16 experiment, which was performed in the Marviken experimental facility, was simulated with the ASTEC and CONTAIN codes. The main purpose of the work was the assessment of the codes for simulating thermal-hydraulic phenomena in a BWR containment at accident conditions. Simulated pressures, atmosphere temperatures and wetwell pool masses are compared to experimental measurements. The results show that both codes satisfactorily reproduced the overall containment thermal-hydraulic behaviour. The simulations also allow a more detailed understanding of the governing mechanisms during the performed experiment.     

Calculating prices and final accounts for housing construction

In countries with unstable conditions, negotiations regarding construction work takes place under conditions of great uncertainty with both sides, the purchaser and the investor, trying to minimize the difficulties. This paper gives an insight of how matters relating to costing are looked at by professionals when faced with such conditions.     

Spontaneous copolymerization of 2-phenyl-2-oxazoline with cyclic carboxylic anhydrides

Summary The copolymers obtained by the spontaneous reaction between 2-phenyl-2-oxazoline (PhOx) and different anhydrides (succinic-SA, maleic-MA and phthalic-PA) in the absence of an added initiator have been studied. The copolymers were characterized by FTIR and ¹³C-NMR spectroscopies. Compositions were determined by quantitative elemental analysis and average molecular weights were obtained by GPC. The PhOx/MA and PhOx/PA were found to be alternating copolymers, whereas the PhOx/SA copolymer was a statistical one, rich in PhOx.     

Stress computations for nearly incompressible materials by the p-version of the finite element method

In the case of nearly incompressible elastic materials the strain energy, the shear stress and the difference of normal stresses can be computed accurately by direct methods when the p-version of the finite element method is used. Computation of the sum of the normal stresses requires special procedures. In this paper such procedures are described and examples are presented.     

Thermodynamics and Stoichiometry of Reactions between Hydrogen Sulfide and Concentrated Sulfuric Acid

A thermodynamic analysis of the possible reactions between hydrogen sulfide and concentrated sulfuric acid shows that four reactions are feasible. However, only two of these reactions apparently occur in experiments at 1 atm and 0°C to 150°C. Hydrogen sulfide is first oxidized by molecular sulfuric acid, forming SO₂, sulfur and water, and then the H₂S may react with the dissolved product, SO₂, to generate sulfur and water. The stoichiometry of the consecutive reactions and their dependence on acid concentration were determined experimentally using mass balance measurements. The results of this study suggest a possible alternative method for sulfur removal and recovery that has more advantages.