A computation of Tr(−1)F in supersymmetric gauge theories with matter

We introduce “multi-twisted” boundary conditions (MTBC) for gauge theories in a finite volume. MTBC can be applied for a class of gauge theories with non-trivial centers and allow the existence of some matter multiplets which transform non-trivially under the center group. The Witten index for the supersymmetric extension of the gauge theory can be calculated when global abelian symmetries exist and turns out to be non-zero and independent of the matter representations.     

A test of charge dependent forces in nuclei

A test of the charge dependence of nuclear interactions based on a fit of Coulomb displacement energies is presented. The results seem to indicate a violation of charge independence comparable or somewhat greater than that found in scattering experiments.     

Neutron activation of chlorine in zirconium and zirconium alloys use of the matrix as comparator

A procedure is described for neutron activation analysis of chlorine in zirconium and zirconium alloys. Calculation of chlorine concentration is performed relative to zirconium concentration in the matrix in order to minimize effects of differences in irradiation and counting geometry. Principles of the method, and the results obtained are discussed.     

Fast calculational algorithm for the Voigt profile

A fast calculational algorithm is proposed for the evaluation of the Voigt profile of primary use in the line-by-line transmittance computations. It consists of a variation from the method proposed by Drayson, providing comparable accuracy with a simplification of the approximating functions, as well as a reduction of the defining regions and the computational times.     

A computational method for approximate evaluation of ionization constants from potentiometric data

A general equation is given for the evaluation of proton dissociation constants from potentiometric data. The method is applicable to monobasic acids, and also polybasic acids, where the successive dissociation steps may or may not overlap. A computer program was employed for the calculations. The method was tested by evaluation of the constants for 22 acids, from monobasic to octobasic, with satisfactory agreement with literature data.     

Excess properties and vapor-liquid equilibrium data for the chloroform + tetrahydrofuran binary system at 30°C

Excess molar volume, excess viscosity, excess molar enthalpy, and excess molar Gibbs free energy were calculated from the experimental density, viscosity, heat of mixing and vapor-liquid equilbrium data, respectively, for the chloroform + tetrahydrofuran system at 30°C over the complete molar fraction range. The results have been satisfactorily interpreted by assuming the existence of three species A, AB, and B in mutual equilibrium and that these species mix ideally. Values are given for the equilibrium constant and heat of formation of AB.     

Influence of pH on the Molecular Weight of Poly-3-hydroxybutyric Acid (P3HB) Produced by Recombinant Escherichia coli

The production of ultrahigh molecular weight poly-3-hydroxybutyric acid (P3HB) from carbohydrates by recombinant Escherichia coli harboring genes from Ralstonia eutropha was evaluated. In shaken-flask experiments, E. coli XL1 Blue harboring plasmid pSK::phaCAB produced P3HB corresponding to 40 and 27 % of cell dry weight from glucose and xylose, respectively. Cultures in bioreactor using glucose as the sole carbon source at variable pH values (6.0, 6.5, or 7.0) allowed the production of P3HB with molecular weight varying between 2.0 and 2.5 MDa. These figures are significantly higher than the values often obtained by natural bacterial strains (0.5–1.0 MDa). Contrary to reports of other authors, no influence of pH was observed on the molecular weight of the polymer produced. Using xylose, P3HB with high molecular weight was also produced, indicating the possibility to produce these polymers from lignocellulosic materials.     

An Easy and Efficient Access to 2-Bromo-4-methoxyaniline

2-Bromo-4-methoxyaniline was obtained by treatment of 2,6-dibromo-4-methoxyaniline with n-butyllithium.     

Correlation between damping of sea ripples and other physico-chemical properties in coastal marine water

Summary Rheological data of the marine surface obtained from frequency wave spectra are compared with physico-chemical analyses of water samples drawn simultaneously from half a meter below the interface in fifteen preselected locations along a stretch of Tuscan Coast located between the Arno and Serchio rivers. The study has proved the presence of adsorption films tightly related to the rivers' plumes. A good correlation between the anionic surfactants detected in gas-bubble-enriched samples and the adsorbent excess measured at the surface has been observed. Implications of the multifrequency radar remote-sensing technique are here discussed.