Der Einsatz von Sorbentien räumlich-globulrer Struktur zur Abtrennung radioaktiver Verunreinigungen aus Wasser

Abstract

Possibilities of using a new generation of sorbents have been investigated. Polymers of spatial-globular (spherulitic) structure (RGS polymers) have been tested to separate Cs, Sr and rare earth elements – which can also be radioactive contaminants – from different waters.

RGS polymers are both, solids and highly-disperse systems being extremely permeable to fluids and gases with low pressure decline. They were currently used to clean industrial waste-water.

It is shown that these polymers can be used successfully to separate radionuclides. Polymers RGS-81 and RGS-112 have high distribution coefficients for CS, Sr, Sc, the lanthanide series and Hf in weakly acid solutions. In HF solutions, Sc and Hf can be separated from Cs, Sr and the lanthanides.     

Beiträge zur Mikrobestimmung von Kohlenstoff-14 und Tritium

Die Verwendung Con¹⁴C und Tritium zur Lösung kinetischer und analylischer Probleme erfordert zuverlässige Analysenmethoden. Es wird iiber die Herstellimg von Meβgasen durch Naβcerbrennung mil Chromsäure-Jodsäure-Gemischen, Trockenverbrennung in Gegenwart Con Katalysatoren wie Kupferoxid, Kobaltoxid und Zersetzungsprodukte des Silberpermanganats und durch Umsetziingentm geschlossenen Rohr berichtet. Die Aktivitätsniessungen erfolgten auf cerschiedene IVeise. Hier werden besonders die Ergebnisse diskutiert, die durch Ionisationskammermessungen erzielt wurden. Schlieβlich werden einfache Apparaturen zur routinemäβigen Durchfiihrung von Mikroanalysen beschrieben.     

Aus der Praxis: Die Aktivitätsbestimmung von 99mTc

If nonlinear biological processes are investigated by means of tracer experiments they can be modelled with linear kinetic equations (compartment equations) as long as the total system is in a stationary state. But if nonstationary behaviour is included considerations on the kinetics of the individual processes are necessary. Within the range of biological and agricultural investigations especially first order reactions (constant fraction processes), zero order reactions (constant amount processes) and saturation reactions (Michaelis-Menten-kinetics) are to be taken into account. A rigorous treatment of data based on system theory can be preceded by a graphic-algebraic procedure which may be more or less uncertain in its results but which can easily be handled.

An example is given of methodological considerations concerning the combination of evaluation procedures and the discrimination between different reaction mechanisms. It treats protein turnover in 2 different parts of growing wheat plants investigated by means of an ¹⁵N-tracer experiment. Whereas in a stationary system (upper stalk section) linear tracer equations were sufficient irrespective of the true reaction mechanism,for the protein synthesis in the upper leaf as a nonstationary system it was necessary to decide between the hypotheses of a zero order and a first order reaction. In accordance with statements in the literature the unambiguous result was a combination of protein synthesis as a zero order process and of protein degradation as a first order process.     

Neue Meßgeräte unter Einsatz von Mikroprozessoren

A system with 3 new types of radiation meters for intensity measurement, spectrometry, activity measurement and dosimetry is described. The application of microcomputer technique as well as the utilization of data prozessing via personal computers confer to the user extensive rationalization effects in the accomplishment and evaluation of these measurements.     

Modellrechnungen zur Isotopentrennung durch Multiphotonen-Photodissoziation von Molekülen

Für stoßfreie SF₆-Moleküle werden Mulltiphotonen-Photofragmentierungswahrscheinlichkeiten im intensiven IR-LASER-Feld berechnet einschließlich der Isotopenselektivität derartiger Prozesse in Abhängigkeit von der eingestrahlten LASER-Linie, der Leistungsdichte, dem Impulsprofil und der Temperatur. Über ein quantenmechanisches Modell werden die Rotationsschtwingungsniveaus des SF₆-Moleküls, die Verstimmung zwischen LASER- und Molekülschwin-gungsfrequenz und die intramolekulare Schwingungsrelaxation berücksichtigt.     

Beiträge zur Isotopengeochemie von Erdgasen

It is the proper aim of geochemical investigations regarding natural gas to describe the processes of generation, migration and accumulation of gaseous compounds. By this way our research results should contribute to knowledge about the gas generating potential of organic matter and about the expected gas volumes in natural gas deposits.

The main topics in the authors' research project are

- isotopic characterization of hydrocarbon forming organic matter

- simulation of the generation of natural gas components by coalification processes (model experiments including also radiolytic gas formation from organic matter)

- investigation of various separation processes (diffusion, adsorption, solubility, mixing of gases. oxidation of natural gas components) affecting chemical compositions and isotopic signatures

- elucidation of pressure and temperature dependence of separation processes and especially of the elementary isotope separation cofficients in systems gas/sorbent

- as the main result, an interpretation concept for natural gas samples is proposed which is based on chemical and isotopic compositions of methane and ethane in the samples and which takes into consideration also separation processes.

Following this summarizing publication some of the most important results of our research work will be presented in more detail in three separate parts.     

Untersuchungen zur Mehrfach-Emission von Sekundärelektronen

CuBe- and NaCl-targets are bombarded by single electrons (100–600 eV). The secondary electrons accelerated by 40 kV strike the crystal of a scintillation counter, backed by a multichannel analyser. The probabilityP _n of emission ofn=0, 1, 2, 3, ... secondaries can be found from the pulse height distribution. The probability distributionP _n =f(n) shows a characteristic deviation from aPoisson's distribution. There was no evidence that there is a preference for even numbers ofn as found byBarrington andAnderson.     

Methoden zur Bestimmung der Radiaoktivität von verschiedenen Tritium und 14C-doppeltmatkierten Proben

Es wurde eine Methode zur Radioaktivitātbestimmung von Titrium- und ¹⁴C-markierten Substanzen auf Chromatographie und Pherogrammpapier mit dem Flūssigketisszintillationsspektrometer ausgearbeitet. Mit dieser Methode Können bei einem statistischen 2 σ-Fehler von höchsten ± 15% doppeltmarkierte Proben mit einem T/¹⁴C-Verhältnis von höchsten ½ gezāhlt werden. Weiterhin wurden fūr die Radioaktivitätsbestimmungen im Flūssigkeitsszintillationsspektrometer des T-Hamamelosehydrazons und der beim Abbau entstehenden T-markierten Spaltprodukte optimale meβbedingungen sowie die erforderlichen Eichkurven erstellt.     

Die amorphisierung von kristallen durch ionenbeschuss und mechanismen von sekundärprozessen

Results of an experimental study of the ion-electron-emission coefficient of monocrystalline and amorphous germanium as a function of the angle of incidence for 10–30 keV Ne⁺, Ar⁺, Kr⁺ ions are presented. Using the concept of ion channeling in crystals the energy dependence of anisotropy of the ion-electron-emission coefficient is explained.     

Zustände nicht-normaler Parität von N14

A conventional shell model calculation has been made for some odd-parity states of N¹⁴ assuming them to arise from the configurationsp ⁹ d andp ⁹ 2s. Especially we study the limit, when the inequivalent particle is coupled in thejj-scheme to the p-shell configurations. Then a satisfactory picture can be given of the lowest 0^?, 0 and 3^?, 0 level, supposed that the well depth of the interaction potential between the outer particle and thep-shell is chosen properly.