Anti-de Sitter quotients,bubbles of nothing,and black holes

In 3+1 dimensions there are anti-de Sitter quotients which are black holes with toroidal event horizons. By analytic continuation of the Schwarzschild-anti-de Sitter solution (and appropriate identifications) one finds two one parameter families of spacetimes that contain these quotient black holes. One of these families consists of B-metrics (“bubbles of nothing”), the other of black hole spacetimes. All of them have vanishing conserved charges. I. Bengtsson was supported by VR.     

Evaluation of the accuracy of gran plots by means of computer calculations: Application to the potentiometric titration of the total alkalinity and carbonate content in sea water

The use of computer calculations for the determination of the systematic errors associated with Gran plots is demonstrated. The results of such calculations are used to derive “modified” Gran plots capable of locating the equivalence point both more accurately and more precisely. The general principles are exemplified by application to the determination of the total alkalinity and carbonate content in sea water by means of potentiometric titration.     

Hamiltonian treatment of self-dual antisymmetric tensors

Self-dual antisymmetric tensors occur in certain (4n + 2)-dimensional supergravity models, in particular the one connected to type IIB superstrings. So far they have been quantized only using light front methods. Here we show that the existing covariant action for such fields leads to a consistent hamiltonian system also for ordinary “timelike” dynamics, although rather complicated second class constraints are present.     

Description of nuclear moments and nuclear spectra in the particle-rotor model

The particle-rotor model using strong coupling basis functions is briefly reviewed. Recent developments are discussed. For example, a formalism for odd-odd nuclei (and negative parity states in even nuclei) is presented. With a standard neutron-proton interaction, measured spins and moments of transitional and deformed Ho nuclei are used to extract their main configurations. Total energy calculations in the (ε, ψ)-plane based on the particle-rotor model are presented for¹⁸⁵Au.     

Shell structure in nuclei

A review of shell structure for spherical and a variety of deformed nuclei is presented. The microscopic-macroscopic method of Strutinsky is used to calculate potential energy surfaces with the pure harmonic oscillator and the modified harmonic oscillator. New sets of “magic numbers” for a variety of different prolate, oblate and axially asymmetric shapes are generated. Experimental evidence for the special stability caused by these shell effects is presented with special emphasis on the lightest and heaviest nuclei where the effects are most pronounced. The radial diffuseness parameter is treated as a Strutinsky variable and its significance in extrapolating into the superheavy region considered. The calculation of shell effects for high spin states is also reviewed.     

Competition between hydrogen and oxygen dissociation on palladium surfaces at atmospheric pressures

A large change in the surface and interface potential of Pd-films on SiO₂ is observed at a constant ratio between hydrogen and oxygen pressure in the ambient. This observation, which is most probably due to a competition between hydrogen and oxygen for the same dissociative adsorption sites, is described in this communication. Furthermore the potential measurements indicate the presence of another type of hydrogen adsorption sites on the oxygen covered surface.     

Aggregation-induced folding of a de novo designed polypeptide immobilized on gold nanoparticles

This communication reports the first steps in the construction of a novel, nanoparticle-based hybrid material for biomimetic and biosensor applications. Gold nanoparticles were modified with synthetic polypeptides to enable control of the particle aggregation state in a switchable manner, and particle aggregation was, in turn, found to induce folding of the immobilized peptides.     

Design and testing of a small-scale sublimation apparatus

In many areas of scientific research and development, for example in the pharmaceutical industry, it is important to prepare and to characterize crystals of pure organic compounds which are thermodynamically stable. The formation of crystals from the gas phase is technically less straightforward than crystallisation from solution, but sublimation techniques can have several important features. In the present paper we report the design and testing of a novel apparatus for small scale sublimation and fractional deposition of crystals. The instrument has been developed with special reference to the needs in the pharmaceutical industry. A few mg of the samples are enclosed, under reduced pressure, in thin-walled glass tubes, along which a well defined temperature gradient can be formed. During an experiment the substance will sublime from the hot end of the glass tube and crystals will be deposited along the temperature gradient. The applicability of the instrument has been verified by experiments with several test compounds. Results from experiments with carbamazepine, are reported in some detail. Carbamazepine single crystals of high quality were obtained and the transition temperature between the triclinic (Form I) and the monoclinic (Form III) crystal modifications agreed with literature values.     

A half year's experience with the facit-algol 1 compiler

The Facit-Algol 1 compiler is described briefly. Restrictions compared to Algol 60 and compatibility with other compilers is mentioned. The paper then discusses the experience with the compiler in the areas of teaching, programming, punching, debugging, and program exchanging. The conclusion is that Algol has done well and represents a great step forward.