A new project for the investigation of unsolved problems of ddµ and pdµ catalysis in D2 and H/D mixtures

We propose to study a number of open problems in ddµ and pdµ fusion using the new high-pressure ionization chamber for charged particle identification in coincidence with the n-/e-counter array for the detection of neutrons and µ-decay electrons. Our first objective will be a precise measurement of the absolute rates of resonant and non-resonant ddµ formation in D₂ and HD-gases and their temperature dependence from 40 to 350 K. Both output channels of the dd-reaction:³He + n and t + p will be observed and their ratio sensitive to contributions of S and P-waves will be determined. Simultaneously, we shall investigate the pdµ-cycle and determine the absolute pd-fusion yields in different molecular H/D compositions, observing tritons from nuclear muon capture in³Heµ: pdµ ³Heµ + . We have developed a special system for the preparation of HD-gas with high concentration (96%) of HD and a purity (10^–6).     

Duality and Multiplicative Stochastic Processes on Quantum Groups

An analogue of McKean's stochastic product integral is introduced and used to define stochastic processes with independent increments on quantum groups. The explicit form of the dual pairing (q-analogue of the exponential map) is calculated for a large class of quantum groups. The constructed processes are shown to satisfy generalized Feynman-Kac type formulas, and polynomial solutions of associated evolution equations are introduced in the form of Appell systems. Explicit calculations for Gauss and Poisson processes complete the presentation.     

Speciation of native cations and added radionuclides in raw bovine milk

Partition of native sodium, potassium, magnesium, calcium and radioisotopes of cesium, strontium and curopium was investigated in the aqueous liquid-liquid systems formed after agitation of fresh pasteurized skim bovine milk with 4% w/w water solution of pectin of various degree of esterification (60–93%). The partition of the ions in the membraneless dialysis was described by Donnan equilibria and ion-exchange in the macro- and microheterogenous systems and, within uncertainty of results, does not depend on the degree of esterification. Strong negative non-ideality of Sr and Eu in milk phase is attributed to binding with proteins, casein particles in particular, and complexation with low molecular ligands. Separation factor =D(Sr)/D(Ca) is 0.70±0.06, in favor of strontium concentration in pectin phase. While >96% of cesium is diffusible to pectin phase, only 43–56% (depending on physico-chemical model of dialysis) of strontium behaves in that way, and in original milk phase the percent of strontium cationic form may be as low as 13%.     

Preparative isolation of tetra-, penta- and hexapurine oligonucleotides from partial hydrolysates of depyrimidinated herring sperm DNA

Herring sperm DNA is chemically degraded to a complex mixture of purine nucleotides. The oligonucleotides are separated from the partial hydrolysates by column chromatography. The resulting mixture of trimer to hexamer purine oligonucleotides is subsequently fractionated on QAE-Sephadex into different mixtures of sequence-isomeric purine oligonucleotides. In a final separation, which uses reversed-phase (Nucleosil C18) high-performance liquid chromatography, these mixtures are separated under isocratic conditions into 35 pure defined purine oligonucleotides with four to six monomer units, 14 defined mixtures of sequence-isomeric purine oligonucleotides and several unidentified products. Purity and sequence of the isolated oligonucleotides are determined by the "fingerprint" method. The results of the high-performance liquid chromatographic and the "fingerprint" methods of the isolated oligonucleotides are discussed.     

Thioreductones and Derivatives (G)

Thioreductones and Derivatives . Replacement of one or two (principally also three) O‐atoms in aci‐reductones by sulfur leads to the corresponding thioreductones. In the present paper, different methods of their synthesis are discussed. Substitution of the bromo nucleofug in the 2‐position of 1,3‐dicarbonyl compounds as well as of a 3‐oxosulfone by selected sulfur nucleophiles is assumed to follow an S_RN1 pathway. Characteristic properties, some typical reactions, and selected derivatives were studied. S‐Alkyl‐ and S‐aryl‐substituted cyclic 2‐thioreductones have been found to be synthons for the preparation of vinylogous reductones (2,3‐diacyl‐1,4‐dihydroxy‐1,3‐dienes) and of tetraacyl ethylenes as their bis‐dehydro products.     

Zur konduktometrischen Bestimmung des Ammoniaks und der Phosphors?ure

Zusammenfassung Die gleichzeitige quantitative Bestimmung des Ammoniaks und der Phosphorsäure durch eine einzige konduktometrische Titration mit Natronlauge ist nicht nur bei reinen Substanzen, sondern auch bei technischen Düngemittelproben, bzw. in Gegenwart gewisser Fremdsubstanzen möglich.Von den im Handel üblichen Düngesalzen und Mischdüngern sind in Tab. 8 diejenigen zusammengestellt, die hinsichtlich ihres Ammoniakund Phosphorsäuregehaltes nach der beschriebenen konduktometrischen Methode analysiert werden können. Die Tabelle erhebt keinen Anspruch auf Vollständigkeit. — Bezüglich der erreichten Genauigkeit sei noch einmal in Tab. 9 eine kurze Übersicht gegeben.     

Final dt stickingω s using the “survived moun method”

A new direct measurement of the final dt sticking probability _s using a special data analysis called the survived muon method is presented. The data were obtained at PSI using a high pressure ionization chamber with H/D/T gas mixtures. The method can provide information on final sticking dt +n independent of theoretical models of stripping and initial sticking. It was found: _s=(0.57±0.07±0.02)%. The experiment and the analysis method are discussed in detail.     

Experimental survey of the sticking problem in muon catalyzed dt fusion

The sticking process dt + n, which constitutes the most severe limit to the number of fusions which a muon can catalyze, is reviewed. Many attempts were made to determine by calculations and measurements the probability for initial sticking _s ⁰ (immediately after dt fusion) and for final sticking _s (after the came to rest). Previous results based on neutron disappearance rates and on the observation of -X-rays were controversial and also in some disagreement with theory. New data are reported from PSI on direct observation of final sticking, using a setup with the St. Petersburg ionization chamber. These data mark a significant improvement in reliability and may clarify questions concerning previous discrepancies. The new results is _s(0.56±0.04)%, lower than the theory prediction _s=(0.65±0.03)%, at medium density.