Whistler-mode electron cyclotron emission from the Phaedrus-B endcell

Measurements of whistler-mode electron-cyclotron emission made in the Phaedrus-B tandem-mirror end cell are described. The receiving horn was located on the axis of the machine just outboard of the end cell. Under normal conditions, the signal had a component which was identified as blackbody emission, and an electron temperature was obtained which was in good agreement with electron end loss-energy-analyzer data. In addition, the signal contained short bursts of unknown origin. Significant heating of the electrons due to end-cell ion-cyclotron frequency range (ICRF) was seen. Comparison of end loss and Thomson scattering data shows that emission from hotter edge electrons is responsible for a large part of the total signal     

Stochasticity in many-dimensional nonlinear oscillating systems

Qualitative analytic estimates of the stochasticity limit of one- and many-dimensional nonlinear oscillating systems are derived using the overlapping of first-order resonances as a criterion for stochasticity. Computational results obtained with several very simple transformations are compared with the analytic estimates. Numerical studies significantly below the stochasticity limit of a many-dimensional nonlinear system reveal an example of a very slow instability, the first, to the best of our knowledge.     

Domination in permutation graphs

O(n³) algorithms to solve the weighted domination and weighted independent domination problems in permutation graphs, and an O(n²) algorithm to solve the cardinality domination problem in permutation graphs are presented.     

The development of a membrane-based screening method to detect antibodies to intermediate filament proteins.

Autoantibodies directed against the intermediate filament proteins (IF) arise in a variety of disease states. The authors have investigated the binding of the IF to solid membrane supports in a dot blot format in an attempt to develop a simple procedure to detect antibodies (ab) to IF. Commercially obtained, purified IF were utilized. These were: vimentin (VIM), cytokeratin 8 (CYK), glial fibrillary acidic protein (GFA), desmin (DES), and the neurofilament triplet proteins (68, 160, and 200 KDa, respectively designated LMW, MMW, and HMW). Murine monoclonal antibody (mAb) probes were used to detect the presence and immunoreactivity of IF. The mAb were visualized with HRP-anti-mouse conjugates using alpha-chloronaphthol/H 2O 2 as substrate. The membranes studied were nitrocellulose (NC), and two of modified nylon. Nitrocellulose provided the most reproducible binding; no advantage was found to ensue from the use of the other membranes with regard either to quantitative binding or improved capping. Among the IF studied, VIM, GFA, LMW, MMW, and HMW bound well to NC; optimal mass/dot was 1 mug. Filtered, non-fat dry milk is a better capping agent than either albumin or fetal calf serum, but interferes with ab binding to GFA. Binding of CYK and DES is weak at neutral pH. Standard densitometric techniques provide the possibility of quantitation. We conclude that dot and slot blot assays may be practical methods to detect ab to IF antigens.     

An evaluation of solvent mediators for ion-selective electrode membranes based on calcium bis(dialkylphosphate) sensors trapped in poly(vinyl chloride) matrices

This study on several alkan-1-ols, di-n-octylphenyl phosphorate and di-n-nonyl phthalate as solvent materials in ion-selective electrode membranes based on calcium bis(dialkylphosphate) sensors trapped in a PVC matrix indicates that the best electrodes are made with di-n-octylphenyl phosphonate. These are selective for calcium. The liquid alcohols readily exude from the PVC matrix, and solid alcohols are completely unsuitable for membrane fabrication. However, despite a tendency to be exuded, decan-1-ol gives acceptable electrodes responsive to bivalent cations if calcium bis (di-2-ethylhexylphosphate) is used as sensor. Several selectivity coefficients, k(caj), greater than unity were found, but though such values for j = Na or K do not involve complete loss of selectivity towards calcium, a value of K(CaCu) = 13 for a membrane with di-n-nonyl phthalate as mediator and calcium bis(di-n-decylphosphate) as sensor indicates greater selectivity for copper than for calcium.     

Pattern recognition strategies for molecular surfaces. I. Pattern generation using fuzzy set theory

A new method for the characterization of molecules based on the model approach of molecular surfaces is presented. We use the topographical properties of the surface as well as the electrostatic potential, the local lipophilicity/hydrophilicity, and the hydrogen bond density on the surface for characterization. The definition and the calculation method for these properties are reviewed shortly. The surface is segmented into overlapping patches with similar molecular properties. These patches can be used to represent the characteristic local features of the molecule in a way that is beyond the atomistic resolution but can nevertheless be applied for the analysis of partial similarities of different molecules as well as for the identification of molecular complementarity in a very general sense. The patch representation can be used for different applications, which will be demonstrated in subsequent articles.     

Uranium(VI) separation from aqueous solution by calix[6]arene modified textiles

The separation of uranium(VI) from aqueous solution by textile bound uranophile calix[6]arenes is possible at pH values ≥4. A maximum of 7.6^.10^-7 mol uranium per 1 g of the calixarene modified textile is bound at pH 5. The influence of competing ions on the uranium separation at pH 5 is very small. However, at pH 7 in carbonate rich waters calcium ions have a competing effect. Under environmentally relevant pH conditions the uranium is strongly bound to the calixarene modified textile. Under acidic conditions an almost complete regeneration of the calixarene modified textile is possible. The regenerated material can be utilized for further uranium separation cycles. This revised version was published online in July 2006 with corrections to the Cover Date.     

Hochselektive spektralphotometrische Bestimmung von Thallium mit Natriumdi?thyldithiocarbamidat

Zusammenfassung Bei der Bestimmung des Tl(III) mit Natriumdiäthyldithiocarbamidat konnte durch Überführung des mit Tetrachlorkohlenstoff extrahierten Thalliumdiäthyldithiocarbamidat-Komplexes in den Kupferdiäthyldithiocarbamidat-Komplex eine etwa 20 fache Verbesserung der Empfindlichkeit erreicht werden. Es wurde eine Vorschrift ausgearbeitet, welche die spezifische Bestimmung des Tl in vielen Materialien erlaubt. Von 60 untersuchten Kationen und 13 Anionen stört nur Bi.

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Highly selective spectrophotometric determination of thallium by sodium diethyldithiocarbamate

The spectrophotometric determination of thallium as Tl(III)-diethyldithiocarbamate can be improved substantially by transformation of the Tl-complex (extracted in CCl₄) into the Cu-complex. By this modification the sensitivity of the method is enhanced by a factor of about 20. A procedure has been worked out, which allows the specific determination of Tl in many materials. Of 60 cations and 13 anions tested only Bi interferes with the Tl determination.

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Für die Überprüfüng des Manuskriptes bin ich Herrn Dr. P. Baertschi zu Dank verpflichtet.     

Rotationally inelastic scattering from surfaces HF(g) + LiF(001)

Rotationally inelastic scattering has been measured for a supersonic beam of HF off a clean LiF(001) surface, as a function of surface temperature and incident and final scattering angles. Rotational accomodation was found to be incomplete. Angular distributions were broad (substantially broader than cos θ_f) and independent of the rotational inelasticity.