Neutrino mass and cosmological baryon excess in left-right symmetric grand unified theories

In left-right symmetric grand unified theories both the smallness of the neutrino mass and a sizable cosmological baryon excess can be ascribed to a superheavy Majorana lepton. We show, taking SO(10) as the simplest model of this kind, that the largest neutrino mass is constrained to lie between 10^?3 eV and 100 eV in order to give the observed magnitude of baryon excess.     

Glucosidation shifts of allylic and benzylic alcohols in 13C NMR spectroscopy

The ¹³C FT NMR spectra of β-D -glucopyranosides (including their tetraacetates) of several secondary allylic and benzylic alcohols were compared with those of methyl β-D -glucopyranoside and the corresponding parent alcohols. The characeristic glucosidation shifts observed for these alcohols may be applicable to the determination of the absolute configuration of the hydroxy group in these alcohols.     

Page usage in a quadtree index

This paper provides a characterization of the storage needs of a quadtree when used as an index to access large volumes of 2-dimensional data. It is shown that the page occupancy for data in random order approaches 33%. A precise mathematical analysis that involves a modicum of hypergeometric functions and dilogarithms, together with some computer algebra is presented.A brief survey of the analysis of storage usage in tree structures is included. The 33% ratio for quadtrees is to be compared to the figures for binary search trees (50%), tries (69%), and quadtries (46%).The research of this author was done while visiting INRIA, Rocquencourt, France under support from the Ministry of Education of Japanese Government.Work of this author was supported in part by the Basic Research Action of the E.C. under contract No. 3075 (Project ALCOM).     

Cooperative chain relaxation in miscible polymer blends

Orientation relaxation of dissimilar chains in the molten miscible blends, poly(methyl methacrylate)/poly(vinylidene fluoride) and poly(methyl methacrylate)/poly(vinylidene fluoride-co-trifluoroethylene), were investigated by measuring (1) the change of infrared dichroic ratio with time after the uniaxial stretching of film specimens, (2) the shear stress relaxation spectrum, and (3) birefringence relaxation in shear. The dissimilar polymers showed an identical time variation of the normalized Hermans orientation function. The blend showed a relaxation spectrum with a single characteristic relaxation time τ_c, depending on the blend composition. The birefringence relaxed monotonically, remaining positive. These results suggest that the dissimilar polymers do not relax independently but cooperatively. This behavior may be induced by a constraint due to the specific interactions between the dissimilar polymers, e.g., weak hydrogen bonding. For the cooperative chain relaxation, a third power relationship was found; τ_c/τ_e vprop; (M/M_e),³ where τ_e and M_e are the relaxation time and molecular weight of entanglement strand, respectively, and M is the number average molecular weight in the blend.     

Mössbauer effect of57Fe in spin frustration system,CsCoCl3

The Mössbauer spectra of 3%⁵⁷Fe doped CsCoCl₃ revealed marked relaxation in all phases. The relaxation was interpreted in terms of propagating domain walls along the magnetic chains together with the transition between the lowest doublet and the low excited singlet levels. The hyperfine field of 24.5T was observed at 4.5K.     

Quantum vacuum energy and singularity-free Kaluza-Klein cosmology

We present a class of cosmological models in which vacuum collapse to curvature singularity is prevented by the generalized gravitational Casimir energy. The mechanism works in higher dimensions, and gives rise to Kaluza-Klein cosmologies free from singularity.     

Liberation of excess energy and retransformation of mechanically activated cadmium sulphide

On heating vibro-milled CdS containing the strained high-pressure rock salt phase, the excess energy was gradually liberated accompanied by the retransformation into more stable phases and the restoration of their crystallinity. Profiles of DSC curves, inter-relationships between thermal and crystallographical properties, the stability of each phase and the mechanism of the mechanochemical activation are discussed. A direct retransformation of the strained high-pressure phase was found to accompany the liberation of the excess energy.