Pressure dependence of the electric field gradient in Sb and Sb1−x M x (M=ln,Zn, Ge,Pb, Cd,Sn) at the site of111Cd

Using the¹¹¹Cd-TDPAC (time differential perturbated angular correlation) method, the pressure dependence of the electric field gradient (EFG) in Sb and Sb_1–x M _x (M=ln, Zn, Ge, Pb, Cd, Sn) was investigated. The application of a phenomenological ansatz for the parametrisation of the pressure and temperature dependence of the EFG made it possible to combine temperature data gained in former studies [1], [2] with the pressure dependent data presented in this paper. The resulting pressure dependence of –2±0.2 MHz/kbar is shown to be independent of concentration and element of admixture. Results for the volume and explicit temperature dependence agree with existing information on the mixed system Sb_1–x M _x (M=ln, Zn, Ge, Pb, Cd, Sn); the investigation of the EFG in Sb_1–x–y M _x Pb _y showed that the resulting EFG may be interpreted as the weighted sum of the individual contributions of the two metals.This paper is dedicated to Prof. Dr. W. Kreische on the occasion of his 60th aniversary on 02.02.1995     

Bifractality of the devil’s staircase appearing in the burgers equation with brownian initial velocity

It is shown that the inverse Lagrangian map for the solution of the Burgers equation (in the inviscid limit) with Brownian initial velocity presents a bifractality (phase transition) similar to that of the Devil’s staircase for the standard triadic Cantor set. Both heuristic and rigorous derivations are given. It is explained why artifacts can easily mask this phenomenon in numerical simulations.     

Few-neutron removal from238U at relativistic energies

As part of a comprehensive study of uranium fragmentation at relativistic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for severalxn channels at projectile energies of 600 and 950A MeV using targets of Al, Cu and Pb. The variation of the experimental cross sections with target nuclear charge is used to disentangle nuclear and electromagnetic contributions. The electromagnetic cross sections agree surprisingly well with a simple harmonic oscillator calculation of giant dipole resonances based on measured photonuclear cross sections and do not require an extra enhancement of the two-phonon giant dipole excitation as concluded from similar measurements with¹⁹⁷Au.     

Simultaneous Preconcentration and Separation of Chromium(III) and Chromium(VI) at the Low-Temperature Directed Crystallization of Natural Water

It was shown that low-temperature directed crystallization of natural water can be used for separating chromium(III) and chromium(VI). At a moderate crystallization rate (6–10 mm/h), the final part of the ingot (concentrate) is a suspension containing chromium(III) and chromium(VI) in the solid and liquid phases, respectively. It is proposed to separately determine these chromium species by atomic absorption spectrometry after separating the phases by centrifugation and dissolving the precipitate in acids.     

Analytical Chemistry at the Institute of Single Crystals of the National Academy of Sciences of Ukraine

The paper describes the history and main lines of inquiry of the Analytical Laboratory at the Institute of Single Crystals (Kharkov, Ukraine) organized in 1955.     

Canonical representations of the Lie superalgebraosp(1,4)

The method for constructing infinite-dimensional representations of Lie superalgebras proposed by the authors recently is applied to the superalgebraosp (1, 4). Explicit formulae for its generators in terms of two or three pairs of operators fulfilling the canonical commutation relations, at most one pair of operators fulfilling the canonical anticommutation relations and at most one real parameter are obtained. The generators of the Lie subalgebrasp (4, ) osp (1,4) are represented skew-symmetrically and both the Casimir operators are equal to multiples of the unity operator.Dedicated to Professor Ivan Úlehla on the occasion of his sixtieth birthday.     

Liquid chromatographic methods for biotransformation studies of ochratoxin A

Liquid chromatographic methods were used for the detection of ochratoxin A (OTA) and its metabolites ochratoxin alpha (OTalpha), 10-hydroxy OTA (10-OHOTA), 4R-hydroxy OTA (4R-OHOTA) and the ethyl ester of OTA (OTC) in in vitro samples, obtained with Caco-2 cell culture experiments and in in vivo urine samples from sheep. A high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) and a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method were developed and validated for the detection of OTA and its metabolites OTalpha, 10-OHOTA, 4R-OHOTA and OTC, which was used as internal standard. The LOD/LOQ values for OTalpha, 4R-OHOTA and OTA were 0.63/2.11, 0.99/3.31 and 0.84/2.81 microg/L, respectively, for the HPLC-FLD method and 0.98/3.28, 1.11/3.72 and 0.88/2.96 microg/L, respectively for the LC-MS/MS method. Within-day and between-day precision were both <12% for the HPLC-FLD method, and <10% for the LC-MS/MS method. The recovery of OTA and its metabolites ranged between 71 and 111% for the HPLC-FLD method and between 79 and 110 % for the LC-MS/MS method. In the first experiment only OTA was added to the Caco-2 cells while in the second experiment 3-methylcholanthrene (3MC) was also present in the cell culture systems. Besides OTA, which was recovered in all the samples, an unknown compound was also observed in the second experiment. When 3MC was added, the results showed that the OTA concentration in the basolateral samples was decreased by 50%. The methods were also implemented for the analysis of urine samples of sheep, fed increasing amounts of OTA. With the HPLC-FLD method it could be concluded that the concentration of OTA and OTalpha increased according to ingested amounts of OTA, with OTalpha being the most abundant compound. The results obtained with the LC-MS/MS method confirmed these results. Copyright (c) 2008 John Wiley & Sons, Ltd.