Two particle rapidity correlation in proton-emulsion nucleus interactions at 400 GeV

We present a study of two-particle correlations in proton-emulsion nucleus reactions at 400 GeV. In particular the correlations at different nuclear excitations and different rapidity regions are treated. Positive correlations, depending on nuclear excitation, are observed in the rapidity region η<1.5.     

Adsorption of SO2 on alumina

The adsorption of SO₂ on alumina used in the aluminium industry, the so-called smelter-grade alumina, was studied in the temperature range 15–120°C. It was found that at temperatures lower than 40°C, sulphur dioxide was bonded to alumina reversibly by physical forces, and the adsorption could be described satisfactorily by the Langmuir adsorption isotherm. The heat of adsorption was estimated to be −33 kJ mol⁻¹. At temperatures ranging from 80°C to 120°C, which prevail in dry scrubbers in the aluminium industry, the heat of adsorption was determined to be −56 kJ mol⁻¹. When SO₂ was adsorbed at temperatures higher than 80°C, about 30 % of the SO₂ could not be desorbed even if the samples were heated up to 250°C. In the presence of SO₂ and oxygen, the formation of sulphate was observed at temperatures above 90°C.     

Ein Beitrag zur Kenntnis der Biogenese der Sialinsäure

Zusammenfassung Die Konzentrationen der Brenztraubensäure und der Eiweißzuckerkomponenten wurden in 150 Seren, deren Struktur im Sinne eines deutlichen Anstiegs der-Globulinfraktionen verändert war, ohne Rücksicht auf die Ätiologie dieser Dysprotoeinämien, ermittelt.Aus den Resultaten ist ersichtlich, daß sich am Stoffwechsel der Kohlenhydratkomponenten der Eiweißzucker auch die Brenztraubensäure beteiligt. Aus einem Vergleich der Mittelwerte der genannten Konzentrationen bzw. deren Indices geht hervor, daß zwischen dem Anstieg der Konzentration der Brenztraubensäure und des Hexosamins einerseits, der der Sialinsäure anderseits eine Beziehung besteht. Dies bekräftigt die Annahme, daß auch die Biosynthese der Sialinsäure über die Brenztraubensäure und das Hexosamin ablaufen könnte.

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Summary The concentrations of pyruvic acid and the protein sugar components were determined in 150 sera, whose structure was altered in the sense of a pronounced increase in the-globulin fractions, without consideration of the etiology of these dysproteinemias.It can be seen from the findings that pyruvic acid is also a participant in the metabolism of the carbohydrate components of the protein sugars. From a comparison of the mean values of the cited concentrations or their indices it may be concluded that a relation exists between the rise in the concentration of the pyruvic acid and of the hexosamine on one hand and that of the sialinic acid on the other. This supports the assumption that the biosynthesis of the sialinic acid also can proceed via pyruvic acid and hexosamine.

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Résumé On a déterminé les concentrations en acide pyruvique et en glucoprotéides de 150 sérums dont la structure était altérée par une augmentation importante en-globulines, sans prendre en considération l'étiologie de ces dysprotéinémies.Les résultats montrent clairement que l'acide pyruvique participe aussi à l'assimilation des constituants hydrocarbonés des glucoprotéides. La comparaison des valeurs moyennes des concentrations en question met en évidence une relation entre l'augmentation de la concentration en acide pyruvique et en hexosamine d'une part et celle de l'acide sialinique d'autre part. Ceci renforce l'hypothèse que la biosynthèse de l'acide sialinique pourrait aussi découler via l'acide pyruvique et à l'hexosamine.

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Herrn Prof. Dr. Ing.Fritz Feigl zum 70. Geburtstag gewidmet.     

Electrochemical behaviour of lanthanum fluoride in molten fluorides

The electrochemical behaviour of lanthanum fluoride dissolved in molten lithium fluoride and in eutectic mixture LiF-CaF₂ was investigated by cyclic voltammetry and laboratory electrolysis. The cyclic voltammetry experiments were carried out at 900°C and 800°C, respectively, in a graphite crucible (counter electrode). Several types of working electrodes (Mo, W, Ni and Cu) were used. Ni/Ni(II) was used as a reference electrode. Laboratory electrolysis was carried out in the system LiF-CaF₂-LaF₃ at 800°C in galvanostatic (j _c = −0.21 A cm⁻²) and potentiostatic (E = 0.87 V) regimes. In both cases, nickel served as the cathode and graphite as the anode. It was found that no new separate reduction peak occurred on the molybdenum or tungsten electrodes in the investigated systems. When copper or nickel electrodes were used, new peaks corresponding to the reduction of lanthanum(III) to lanthanum metal appeared. This can be explained by the formation of alloys or intermetallic compounds of lanthanum with copper or nickel. X-ray microanalysis showed that lanthanum was electrodeposited together with calcium under formation of intermetallic compounds with the electrode materials in the galvanostatic regime. In the potentiostatic regime, mainly lanthanum was deposited, which enabled its separation.     

When size matters: exploring the potential of aminocyclopropenium cations as head groups in triphenylene-derived ionic liquid crystals in comparison with guanidinium and ammonium units

The influence of the size of a single ionic head group on the mesomorphic properties of hexaalkoxytriphenylenes was investigated by synthesising three derivatives with increasing head group diameter. The derivatives were investigated with optical polarising microscopy (POM), differential scanning calorimetry (DSC) and X-ray scattering (WAXS, SAXS). For the derivative with the small trimethylammonium head group, an enantiotropic mesophase was found. The derivative with the bigger tetramethylguanidine head group only showed a monotropic phase and the derivative with the largest bisdiisopropylaminocyclopropenium head group displayed no liquid crystaline properties at all.     

First Monte-Carlo modelling of global beryllium migration in ITER using ERO2.0

ERO2.0 is a recently developed Monte-Carlo code for modelling global erosion and redeposition in fusion devices. We report here on the code's application to ITER for studying the erosion of the beryllium (Be) first wall armour under burning plasma steady state diverted conditions. An important goal of the study is to provide synthetic signals for the design of two key diagnostics: the main chamber visible spectroscopy and the laser in-vessel viewing systems. The simulations are performed using toroidally symmetric plasma backgrounds obtained by combining SOLPS simulations extended to the wall using the OSM-EIRENE-DIVIMP edge code package. These are then further combined with a shadowing model using magnetic field line tracing to provide a three-dimensional correction for the flux patterns. The resulting plasma wetted area, which amounts to ∼10% of the total first wall area, is in excellent agreement with shadowing calculations obtained with the SMITER field line tracing code. The simulations reveal that the main Be erosion zones are located in regions intersected by the secondary separatrix, in particular the upper Be panels, which are close to the secondary X-point. For the particular high-density Q = 10 background plasma case studied here, ∼80% of the eroded Be is found to re-deposit on main chamber surfaces. The rest migrates in almost equal parts to the inner and outer divertor and is deposited close to the strike lines.     

Rapid Determination of Meropenem in Biological Fluids by LC: Comparison of Various Methods for Sample Preparation and Investigation of Meropenem Stability

A rapid and sensitive LC-UV method was developed and validated for the determination of meropenem, in human plasma and urine. Meropenem retention time was 4.8 min. Method development was based on comparative analysis of different extraction methods published as well as careful study of meropenem stability in biological samples under different conditions. Best results in plasma sample preparation were obtained from protein precipitation with methanol. LOQ was 0.1 µg mL^?1 for plasma and 1 µg mL^?1 for urine samples. Meropenem in plasma has low stability at room temperature (<20% of original content after 12 h), but had acceptable stability when the whole analysis procedure was designed to minimize the exposure of meropenem-containing samples and solutions to temperatures higher than 4 °C. The developed method was applied to a human pharmacokinetic study in patients with acute peritonitis.     

Diastereo- and Enantioselective Cross-Couplings of Secondary Alkylcopper Reagents with 3-Halogeno-Unsaturated Carbonyl Derivatives

Chiral secondary alkylcopper reagents were prepared from the corresponding alkyl iodides with retention of configuration by an I/Li-exchange using tBuLi (−100 °C, 1 min) followed by a transmetalation with CuBr ⋅ P(OEt)₃ (−100 °C, 20 s). These stereodefined secondary alkylcoppers underwent stereoretentive cross-couplings with several 3-iodo or 3-bromo unsaturated carbonyl derivatives leading to the corresponding γ-methylated Michael acceptors in good yields and with high diastereoselectivities (dr up to 96:4). The method was extended to enantiomerically enriched alkylcoppers, providing optically enriched advanced natural product intermediates with up to 90 % ee.