Multielementanalyse von Schwebst?uben der Stadt Ulm und Vergleich der Luftbelastung mit anderen Regionen

Zusammenfassung Es wurden die Konzentrationen von 54 Elementen in der Luft der Stadt Ulm, die als Beispiel für eine mittelgroße Industriestadt angesehen werden kann, bestimmt. Hierfür wurden die auf Celluloseacetatmembranfiltern mit durchflußgeeichten Geräten gesammelten Schwebstäube von zwei Probenahmeorten in der Innenstadt (Stadtzentrum/Münster und Ehinger Tor — ein stark frequentierter Verkehrsknotenpunkt) mittels INAA, ETAAS und Mikrotitrimetrie analysiert.Im Vergleich mit dem Stadtzentrum wurde in der Luft des Standortes Ehinger Tor für fast alle Elemente eine deutlich höhere Konzentration gemessen, die im allgemeinen auf eine höhere Gesamtstaubkonzentration zurückzuführen ist. Lediglich die Elemente Br, Cr, Cu, Mo, Pb und Sb sind auch im Luftstaub dieses Sammelortes erheblich angereichert. Dies kann durch den Straßenverkehr als Emissionsquelle an diesem stark frequentierten Verkehrsknotenpunkt erklärt werden. Im Stadtzentrum wurden die Elementhöhenprofile durch Probenahme in 2, 16 und 70 m über dem Boden ermittelt. Für die meisten Elemente konnte dabei kein wesentlicher Einfluß dieses Probenahmeparameters auf die Konzentration festgestellt werden.Allgemein liegen die ermittelten Konzentrationen im Rahmen der wenigen anderen bisher untersuchten mittelgroßen Städte.

---

Multielement analysis of airborne dust of the city of ulm and comparison with other regions

Summary The concentrations of 54 elements were determined in the air of the city of Ulm, which can serve as an example for a well industrialized city of medium size. The airborne dust samples were collected at two places (city center/Münster and Ehinger Tor — a center of traffic) with flow calibrated samplers on cellulose acetate membrane filters, and analyzed by INAA, ETAAS and micro titration.The higher concentrations of nearly all elements in the air of the sampling place Ehinger Tor in comparison with that of the city center is approximately proportional to the increased concentration of the whole dust at this sampling place. Only the Elements Br, Cr, Cu, Mo, Pb and Sb are enriched in the airborne dust, which can be explained by the heavy street traffic at this sampling place. In the city center, samples were collected in the height of 2, 16 and 70 m and, for most elements, only a slight effect of the height on the concentration was found.The element concentrations determined in the air of the city of Ulm are generally at similar level as available results for some few other medium large cities.

---

---

Herrn Prof. Dr. Hartkamp zum 60. Geburtstag gewidmet     

Exact results for one-dimensional disordered bosons with strong repulsion

We study one-dimensional disordered bosons with strong repulsive interactions. A Bose-Fermi mapping expresses this problem in terms of noninteracting Anderson-localized fermions, whereby known results for the distribution function of the local density of states, the spectral statistics, and density-density correlations can be transferred to this new domain of applicability. We show that disorder destroys bosonic quasi-long-range order by calculating the momentum distribution, and comment on the experimental observability of these predictions in ultracold atomic gases.     

Improved limit on the rate of the decay K+ --> pi(+)&mgr;(+)e(-)

We report results of a search for the lepton-family number violating decay K+-->pi(+)&mgr;(+)e(-) from data collected by experiment E865 in 1996 at the Alternating Gradient Synchroton of Brookhaven National Laboratory. We place an upper limit on the branching ratio at 3.9x10(-11) ( 90% C.L.). Together with results based on data collected in 1995 and an earlier experiment, E777, this result establishes a combined 90% confidence level upper limit on the branching ratio at 2.8x10(-11). We also report a new upper limit on the branching ratio for pi(0)-->&mgr;(+)e(-) of 3.8x10(-10) ( 90% C. L.).     

Strong interaction shifts and widths in light kaonic atoms

Energy shifts and line widths of X-ray transitions in kaonic atoms have been measured with an accuracy of about 10%. These data have been interpreted in terms of an optical potential. Whereas earlier approaches based on the free K⁻N scattering lengths fail to reproduce the data, a set of effective parameters consistant with all now available experiments could be derived.     

Elektrophile Substitution von Cymantrenen, 1. Mitt.Friedel—Crafts-Acetylierung von Halogen- und Acylaminocymantrenen

Zusammenfassung Die Leistungsfähigkeiten der bisher bei Cyclopentadienylmetallocenen zur Trennung und Konstitutionszuordnung von Stellungsisomeren verwendeten Methoden werden verglichen. Dabei erweist sich die NMR-Spektroskopie-neben der chemischen Korrelation-als allgemeinstes Verfahren zur Strukturermittlung, da die Spektren erheblich einfacher als bei Benzolderivaten sind.Die vier Halogencymantrene, -Dijodcymantren und Benzyloxycarbonylamidocymantren (9) sowie Acetamidocymantren (10) wurden nachFriedel—Crafts acetyliert (mit Acetylchlorid/AlCl₃/CS₂) und die Isomerenverteilung durch Gaschromatographie und NMR-Analyse ermittelt. In allen Fällen überwiegen die -Isomeren. Die Strukturzuordnung wurde sowohl auf Grund der NMR-Spektren als auch durch chemische Korrelation der isolierten Isomeren mit Produkten gesicherter Konstitution durchgeführt. Aus9 entstehen bei derFriedel-Crafts-Reaktion direkt - und -Amino-acetylcymantrene, die sich, da nur das -Isomere eine intramolekulare H-Brücke ausbildet, besonders glatt trennen lassen. An Hand der gewonnenen Daten werden die Substituenteneffekte diskutiert.

---

The methods employed hitherto for the separation and structural assignment of positional isomers of cyclopentadienyl metallocenes are compared with regard to their efficiencies. Besides chemical correlation, NMR spectroscopy proves to be most versatile, mainly because the spectra are much simpler than those of benzene derivatives.The four halogenocymantrenes, -di-iodocymantrene, benzyloxycarbonylamidocymantrene (9), and acetamidocymantrene (10) were acetylated according toFriedel-Crafts (with acetyl chloride/AlCl₃/CS₂) and the ratios of isomers determined byGLC and NMR analysis. In all cases the -isomers were found to predominate. Structural assignments were made both by NMR spectra and chemically by correlation of the isomers isolated with compounds of know structure. - and -aminoacetyl cymantrene are formed from9 in one step byFriedel-Crafts reaction. The two isomers are easily separable due to intramolecular hydrogen bonding in the -compound. On the basis of the data obtained substituent effects are discussed.

---

---

Mit 1 Abbildung     

Multielement radiochemical neutron activation analysis of high purity aluminium

Summary A radiochemical neutron activation analysis technique for the determination of 51 elements in high purity aluminium via medium- and long-lived indicator radionuclides has been developed. It is based on a separation procedure involving the removal of ²⁴Na, produced via the reaction ²⁷Al(n,), on a hydrated antimony pentoxide column and further separation of the radionuclide mixture into 11 groups on two Dowex 1X8 columns and one Dowex 50X8 column from HCl/HF and HCl media as well as the extraction of copper with APDTC in chloroform. The indicator radionuclides for the significant impurities thorium and uranium, ²³³Pa and ²³⁹Np, were separated with satisfactory selectivity in one fraction. For 43 elements, the limits of detection are <10 ng/g, for thorium and uranium, they are 50 pg/g. The method was applied to the analysis of different high purity aluminium samples. For a number of elements, the results of this technique are compared with those of other techniques.

---

Radiochemische Multielement-Neutronenaktivierungsanalyse von hochreinem Aluminium

---

Dedicated to Prof. Dr. W. Fresenius on the occasion of his 75th birthday     

The Kinetics of the gas-phase isomerization of 1,trans-3,trans-5-heptatriene into the cis-5-isomer catalyzed by Nitric Oxide and the stabilization energy in the pentadienyl radical

The kinetics of the nitric oxide catalyzed, homogeneous, gas-phase isomerization of 1,trans-3,trans-5-heptatriene have been studied for temperatures ranging between 130°C and 241°C. The very clean reaction involves exclusive geometrical isomerization about the 5,6-π-bond. The observed rate constants for \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm NO} + trans - {\rm 3,}trans{\rm - 5}\stackrel{1}{\rightarrow}trans - 3,cis - 5 + {\rm NO} $\end{document} can be represented (with standard errors) by log k₁ = (7.18 ± 0.06) – (16.75 ± 0.12)/θ, where θ = 2.303 R T in kcal/mole. The consecutive-step reaction mechanism involves addition of NO to the double bond (K_{a, b} = k_a/k_b), followed by rotation of the 5,6-C? C bond in the adduct radical (k_c.) Analysis of the observed activation parameters shows, that k_c is rate-controlling and consequently k₁ = k_cK_{a, b}. Estimates of k_c and K_{a, b} lead to a value of k₁ in good agreement with experiment. Comparing our data with those previously obtained for the similar 1,3-pentadiene system results in a value for the extra stabilization energy generated in the 1,3-heptadienyl radical of 18.5 ± 1.7 kcal/mole. This value is discussed in view of comparable data in the literature.     

Strong interaction effects in antiprotonic atoms

Yields of the last observable X-ray transitions in antiprotonic atoms have been measured for groups of neighbouring elements. In sulphur a natural line width and an energy shift could be observed. These data are compared with calculations describing the p?-nucleus interaction in terms of an optical potential using the free p?-N scattering lengths.