Break-Through Investigation on Uranium Isotope Separation in the System Uranyl Ion Solution Ti(III)-Cationic Resin

A break-through experiment on separation of uranium isotopes was carried out by use of a cation-exchange resin in Ti(III) form. By analyzing the experimental results the apparent equilibrium constants of the order K = 1·00021–1·00034 were determined.

The maximum value on the experimental curies of the isotopic ratio versus effluent volume was interpreted by considering two antagonistic isotope effects: one relatively large given by an exchange reaction between U(IV) in resin and U(VI) in solution and another smaller given by the reduction reaction of U(VI) with Ti(III). The difference of the equilibrium constants of the these two isotope effects as a function of temperature was used for the determination of the apparent thermodynamic values of the resultant process, determined experimentally: ΔH⁰ = 0.8542 cal mol^?1 and ΔS⁰ = 3.33×10^?3cal°K^?1.     

Characteristics of charged particle multiplicity for¯nn andnn interactions and¯nn annihilations at 6·1 GeV/c

Topological cross sections and characteristics of charged particle multiplicity distributions for¯nn andnn interactions and¯nn annihilations at 6·1 GeV/c are presented. KNO-distributions for¯nn andnn interactions are very similar. Characteristics for¯nn and¯pp annihilations are identical at equal energies.Dedicated to the 30th anniversary of the Joint Institute for Nuclear Research.     

Statistical Evaluation of Cu,Mn and Zn Determinations in Biological Samples by Radiofrequency Capacitively Coupled Plasma Atomic Emission Spectrometry Using the Bland and Altman Test

This paper presents a statistical comparison of Cu, Mn and Zn determinations in biological samples by low power radiofrequency capacitively coupled Ar plasma (275W; 27.12MHz; 0.4Lmin^–1 flow rate) atomic emission spectrometry and flame atomic absorption spectrometry using statistical analysis according to the Bland and Altman test and linear regression. For a content (µgg^–1 dry mass) of 5-43 Cu, 10-15800 Mn and 8-1100 Zn in fish fillet and freshwater molluscs, there was no significant bias in r.f.CCP-AES for a 95% confidence level. Certified reference materials were analysed by r.f.CCP-AES, and a good agreement between analysis results and certified values was obtained. Matrix effects of Ca and Na and their influence on the detection limits of Cu, Mn and Zn are presented for both methods. As compared to FAAS, r.f.CCP-AES is more prone to interferences and, consequently, the detection limits for Cu, Mn and Zn in biological samples (2; 2 and 3µgg^–1 dry mass) are higher than those in FAAS. In spite of these problems, r.f.CCP-AES is capable of accurate and precise analyses of biological samples.     

Profile distribution of As(III) and As(V) species in soil and groundwater in Bozanta area

The profile distribution of arsenic(III) and arsenic(V) species in soil and groundwater was investigated in the samples collected in 2005 from a hand-drilled well, in the Bozanta area, Baia Mare region, Romania. The total content of arsenic in the soil was in the range of 525–672 mg kg⁻¹ exceeding 21–27 times the action trigger level for sensitive soil. 0.9–11.3 % of the total content was soluble in water, 83.0–92.6 % in 10 mol dm⁻³ HCl and 2.6–13.3 % was the residual fraction. Arsenic(V) was the dominant arsenic species in the soil in the range of 405–580 mg kg⁻¹. The distribution and mobility of arsenic species was governed by soil pH and contents of Al, Fe, and Mn. The mobility of arsenic(V) decreased with depth, while that of arsenic(III) was high at the surface and in the proximity of groundwater. The total concentration of arsenic in groundwater was (43.40 ± 1.70) μg dm⁻³, which exceeded the maximum contaminant level of 10 μg dm⁻³. Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May 2006.     

Disentangling the K-complex of kaonic hydrogen with DEAR

The DEAR (DAΦNE Exotic Atom Research) experiment at the new φ-factory DAΦNE of Laboratori Nazionali di Frascati aims for a 1% measurement of the line shift of the K-complex due to strong interaction in kaonic hydrogen. This presentation is meant to prove that the high statistics and good resolution obtainable with DEAR will be able to disentangle the kaonic hydrogen K-complex lines (a cascade unconstrained fit), obtaining in this way constraints for what concerns the cascade parameters and, consequently, information regarding the physical processes involved in the kaonic hydrogen atomic cascade. This revised version was published online in August 2006 with corrections to the Cover Date.     

Measurement of the kaonic hydrogen x-ray spectrum

The DEAR (DAPhiNE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift epsilon and the width Gamma of the 1s state due to the K(-)p strong interaction are epsilon(1s)=-193 +/- 37 (stat) +/- 6 (syst) eV and Gamma(1s)=249 +/- 111 (stat) +/- 30 (syst) eV, the most precise values yet obtained. The pattern of the kaonic hydrogen K-series lines, K(alpha), K(beta), and K(gamma), was disentangled for the first time.     

New Experimental Limit on the Pauli Exclusion Principle Violation by Electrons��The VIP Experiment

We present an experimental test of the validity of the Pauli Exclusion Principle for electrons based on the concept put forward a few years ago by Ramberg and Snow (Ramberg and Snow in Phys. Lett. B 238:438, 1990). In this experiment we perform a very accurate search of X-rays from the Pauli-forbidden atomic transitions of electrons in the already filled 1S shells of copper atoms. Although the experiment has a simple structure, it poses deep conceptual and interpretational problems. Here we describe the experimental method and recent experimental results, which we interpret as an upper limit for the probability to violate the Pauli Exclusion Principle. We present also future plans to upgrade the experimental apparatus using Silicon Drift Detectors.