Ueber die in einem mittelst Schwefels?ure getrockneten Gase noch enthaltene Menge Feuchtigkeit

Ohne Zusammenfassung749 Republic Street, Cleveland Ohio, U. S. A., 25. Mai 1885.     

Hydrodynamical model of electron-positron annihilation into hadrons

Landau's hydrodynamical model of multiparticle production is formulated for e⁺e^? → hadrons at center-of-momentum energies 10 GeV and higher. An analytical solution to the problem of spherical expansion of a relativistic fluid is presented. When hadrons condense out at the last stage of expansion, fluid thermal motion is taken into account. We derive predictions for multiplicities, average secondary energies and inclusive single particle distributions for various secondary hadrons; these results are then compared to other models. Finally, we investigate the internal consistency of the model.     

Symmetric function means of positive operators

Many authors have studied means involving ratios of the elementary symmetric functions. This work involves generalizing these means to an operator theoretic setting, and extending many of the classical scalar inequalities to operators. It is shown that these operator means are related to electrical networks.     

Focusing mutations into the P. fluorescens esterase binding site increases enantioselectivity more effectively than distant mutations

Rational design of enzymes with improved properties, such as enantioselectivity, usually focuses mutations within the substrate binding site. On the other hand, directed evolution of enzymes usually targets the entire protein and discovers beneficial mutations far from the substrate binding site. In this paper, we propose an explanation for this discrepancy and show that a combined approach--random mutagenesis within the substrate binding site--is better. To increase the enantioselectivity (E) of a Pseudomonas fluorescens esterase (PFE) toward methyl 3-bromo-2-methylpropionate, we focused mutagenesis into the substrate binding site at Trp28, Val121, Phe198, and Val225. Five of the catalytically active mutants (13%) showed better enantioselectivity than wild-type PFE. The increases in enantioselectivity were higher (up to 5-fold, reaching E = 61) than with mutants identified by random mutagenesis of the entire enzyme.     

A family of mixed finite elements for linear elasticity

Summary A family of finite elements for use in mixed formulations of linear elasticity is developed. The stresses are not required to be symmetric, but only to satisfy a weaker condition based upon Lagrange multipliers. This is based on the same formulation used in the PEERS finite element spaces. Elements for both two and three dimensional problems are given. Error analysis on these elements is done, and some superconvergence results are proved.     

Breakdown of scaling in grand unified theories

We investigate the collapse of asymptotic freedom inS U (5) grand unified theory and itsS U (3) _c colour subgroup. It is shown that the change from a decreasing to an increasing gauge coupling constant, in the deep Euclidean, is dramatically sudden.     

Inequalities induced by network connections II. Hybrid connections

It has been found that interesting mathematical relationships arise from a vectorial generalization of Kirchhoff's and Ohm's laws, in which the “resistors” become Hermitian positive semidefinite (PSD) linear operators. In analogy to the parallel connection of resistors Anderson and Duffin studied the parallel sum R : S of two PSD operators on a finite dimensional space, defined by $\text{R : S = R(R + S)}{}^2\text{S}$. Duffin and Trapp then studied the hybrid connection. This paper generalizes some of their results to a much broader class of electrical connections.     

Pd-Na/F double exploding foil photoionization experiment

By means of two exploding foils, we have achieved inner-shell photoionization of Zn-like Pd resulting in the soft X-ray transition 3d ⁹4s ² 3d ¹⁰4p at 46 Å.