Moment problem for effect algebras

We present a solution to the moment problem for effect algebras, concerning mean values of all powers of an observable concentrated on the interval [0, 1] for states from a convex set. We give a solution for particular examples, e.g., for the set of all effect operators. We examine how this problem is related to a socalled E-property. Finally, we give a solution for observables studied in the operational approach to physical theories.     

Kinetics of the solution polymerization of dioxolane in the presence of water

Water acts as a cocatalyst in the polymerization of dioxolane initiated by the ion pair ～Si^⊕HSO₄^?. The dependence of the reaction rate on the water concentration exhibits a maximum, the width of which strongly depends on the concentration of dioxolane. The change of the coordinates of the maximum and its shape with the decrease of the monomer concentration causes the reaction rate to decrease with increasing conversion. The point at which the slope of the conversion curve changes is a function of initial concentration of water. There is a very fast decrease of the concentration of free water in the polymerizing system. The consumption of water is associated with some peculiarities. The amount of free water which remains in the system is a function of the concentration of the original initiator. The ratio [H₂O]_∞/[initiator] is constant over a rather broad range of initial concentration of water.     

160Tb nuclear orientation in yttrium single crystal

First experimental results of¹⁶⁰Tb nuclear orientation in yttrium single crystal matrix are described. The influence of external magnetic field in combination with the crystal field interaction is discussed.     

Observation of a Doppler broadening of the 4438 keV gamma-line of12C in processes12C(n,n′γ)12C and9Be(α, nγ)12C

A Doppler broadening is described of the 4438 keV spectral gamma-line observed by means of a Ge(Li) detector during the deexcitation of nuclei of¹²C in an inelastic scattering¹²C(n, n′γ)¹²C using an²⁴¹Am−Be source as well as during the reaction⁹Be(α, nγ)¹²C taking place in the Am−Be source. The FWHM of the spectral line is equal to (90±4) keV in the latter reaction and (64±8) keV in the former process. Experimental values agree well with theoretical ones. Presented at the Instrumental Activation Analysis Conference, IAA 79, June 4–8, 1979, Klučenice, Czechoslovakia.     

ICP-MS determination of heavy metals in submerged cultures of wood-rotting fungi

Accumulation of five heavy metal ions by five species of wood-rotting basidiomycetes during a 9-day cultivation was studied. Contents of Cd, Cu, Pb, and Zn were measured using ICP-MS; the amount of mercury was determined directly in solid samples using the Advanced Mercury Analyser. A standard operation procedure for the sample preparation and determination of metal content was developed and validated. Presence of Cd, Cu, Hg, and Pb decreased the accumulation of zinc by the fungi. The basidiomycete Pycnoporus cinnabarinus exhibited the highest metal binding capacity of all fungi tested.     

Untypical rheological behaviour of the lignite–carboxymethylcellulose–water dispersion system

Suspensions of lignite in a solution of a high molecular weight carboxymethylcellulose show peculiar rheological behaviour. Unless the lignite concentration is sufficiently high, apparent viscosity and viscoelastic moduli of the suspension are lower than those of the pure solution. This effect is not suppressed by changing pH and seems to be common for low-concentrated suspensions in solutions of high molecular weight (bio)polymer. It is explained by specific structuring of the suspensions. Lignite particles at lower concentration separate long cellulose chains and facilitate their movement under shear flow. The particles loosen inter-chain contacts, disturb and release elastic gel-like structure formed by the long cellulose chains, which results in the low strain oscillatory deformation, the decrease in the moduli and the increase in the loss angle. If the amount of lignite particles is sufficiently high, suspension stiffening occurs as usual. No such effect was observed for suspensions prepared from the low molecular weight derivative. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

The use of liquid scintillation spectrometry for the determination of radionuclidic purity of 90Y from a radiochemical 90Y/90Srgenerator

Summary An extraction technique for the separation of ⁹⁰Sr from a high excess of⁹⁰Y has been developed. This procedure can be used for the determination of trace amounts of⁹⁰Sr in⁹⁰Y prepared by a radiochemical⁹⁰Y/⁹⁰Sr generator by liquid scintillation.     

Schnelle Trennung von Barium aus einem Gemisch von Spaltprodukten

Zusammenfassung Eine Methode zur schnellen und selektiven Trennung von Barium aus einem Gemisch von Spaltprodukten wurde ausgearbeitet, die auf der Fällung des Bariumsulfats in Anwesenheit von äDTA beruht. Die Selektivität wurde durch Messung der -Spektren und der Zerfallskurven ÜberprÜft. Die Schnelligkeit der Methode wird durch die Abtrennung des Kernisomers ^137m Ba aus einem im Gleichgewicht befindlichen Gemisch von ^137m Ba und ¹³⁷Cs gezeigt.Das angefÜhrte Verfahren eignet sich fÜr die Herstellung von radiochemisch reinem Barium, fÜr die quantitative Auswertung der Kontamination der Spaltprodukte und fÜr die Berechnung des Alters radioaktiver atmosphärischer Niederschläge.

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Summary A method has been developed for the rapid and selective isolation of barium from a mixture of fission products, based on precipitating barium sulphate in EDTA medium. The selectivity was checked by measuring -spectra and by decay curve analysis. The rapidity of the method is illustrated by the isolation of the ^137mBa isomer from an equilibrium mixture of ¹³⁷Cs+^137m Ba.The method described is convenient for preparing radiochemically pure barium, for a quantitative evaluation of a decontamination with fission products and for determining the age of radioactive fall-out.