On parallel displacement within the light cone and its application in the electrodynamics of charges moving with the velocity of light

It is shown that there exists on the light cone an affine connection which is metric, semisymmetric and locally integrable. There exists a correspondence between this connection and a system of charges moving with the velocity of light. The correspondence reveals in the case of commensurable charges a symmetry which disappears for non-commensurable charges.     

A test strip for diamines in tuna.

This study describes the production of a solid-phase assay (test strip/dipstick test) for putrescine and cadaverine in tuna based on the coupling of an amine oxidase to a peroxidase/dye system. The assay was linear to 75 microM in phosphate buffer, and the minimum detectable concentration was 0.5 microM (< 0.1 ppm), corresponding to 0.01 mg% in spiked extracts. Intra- and interassay precisions were < 20%. Test strips were stable at 4 degrees C for at least 12 months. Lysine, ornithine, and histidine did not react with the assay, and histamine reacted only minimally. Sixteen fish samples were tested by test strip and the standard AOAC protocol, and results were in good agreement.     

Gas chromatographic method for putrescine and cadaverine in shrimp

A gas-liquid chromatographic method developed for the determination of putrescine and cadaverine in fishery products was modified for application to the determination of diamines in shrimp. Addition of potassium chloride and hydrochloric acid to the methanol-water extraction solvent resulted in increased recovery of the diamines and minimized gel formation. The recovery of putrescine increased on average from 64 to 98%, and the recovery of cadaverine increased from 85 to 93%. The chromatographic separation of the derivatized diamines was significantly improved with a change from an OV-225 column (cyanopropyl methyl phenyl methyl silicone) to a more polar HP-Innowax column (crosslinked polyethylene glycol). Background levels of putrescine and cadaverine in known high-quality shrimp ranged from 0 to 0.7 ppm. Shrimp that failed sensory examination generally contained putrescine at levels >4.8 ppm and cadaverine at levels >1.3 ppm.     

Quantum Mechanics of the Supplementary Series

Unitary, irreducible representations of the proper, orthochronous Lorentz group comprise the main series and the supplementary series. The main series is spanned by the complete set of eigenstates of the self-adjoint Casimir operator C ₁=–(1/2)M M , where M are generators of Lorentz transformations. The supplementary series has no such interpretation; moreover it is spurious from the point of view of functional analysis as it does not enter into the integral representation of an arbitrary test function. The author describes the physical context within which the supplementary series arises, nevertheless, in a natural way: it arises if we exponentiate a massless scalar quantum field living in three-dimensional de Sitter space-time and if the appropriate coupling constant is small enough.     

Infrared and Raman spectroscopy at high pressures

Pressure is accepted theoretically as a useful variable. However in a studies on liquid or solid samples, it is still relatively unusual for pressure to be used as an experimental variable. The reluctance of experimentalists to use this theoretically attractive variable is caused mainly by the technical difficulties associated with the use of sufficiently high pressures. In this talk I will try to show that in many cases the experimental limitations are no longer those introduced by the use of high pressures. High pressure spectroscopic studies clearly imply the use of high pressure spectroscopic cells. A brief account will therefore be given of the various types of high pressure optical cells which are currently being used for spectroscopic studies. Each individual high pressure spectroscopic study has its own special justification. However there are a few quite general observations that can be made which cover many of the specific objectives of individual high pressure spectroscopic studies. For example:(i) pressure induced frequency shifts carry unambiguous information about anharmonic terms in the relevant potential function (i.e. the potential V is a function of distance d. therefore pressure can be used to change d and study V.)(ii) all known materials undergo structural phase transitions if the form which is thermodynamically stable under ambient conditions is compressed to high enough pressures: these high pressure phases should be studied.(iii) as the application of pressure forces a material towards a phase transition, the spectroscopic study can be used to gain information about the approaching structural instability.(iv) virtually all infrared and Raman spectra contain examples of Fermi resonance which confuse the interpretation of the spectra and the effects of pressure are valuable aids to the correct assignment of the resonating levels.(v) pressure induced frequency shifts can often give extra information to help with the more reliable assignment of features within a spectrum.The above points will be discussed and illustrated by examples chosen mainly from recent work by members of the spectroscopy group at King's College London.     

Lattice dynamics of InAs under hydrostatic pressures

The lattice dynamics of InAs under variable hydrostatic pressures is investigated on the basis of an ‘11-parameter’ rigid-ion model (RIM). The calculated phonon dispersion curves are in satisfactory agreement with the neutron scattering data (available for the TA modes only) measured at room temperature and atmospheric pressure. The one- and two-phonon densities of states functions and mode Gruneisen parameters have been computed at two arbitrary hydrostatic pressures. The effect of high pressure on the phonon dispersion curves is shown to lead to a typical ‘softening’ in the transverse acoustic modes and eventually to a phase trnasformation of the compound.     

Quantum mechanics of phase and charge and quantization of the coulomb field

A closed dynamical system is constructed which is linear and has the electric charge as one of its degrees of freedom. The system consists of the electric part of the infrared electromagnetic field and of two additional degrees of freedom. Quantization of this system gives quantization of the electric charge in units equal to the constant e. An evidence is indicated that the theory has a nontrivial dependence on the constant e². The dependence on e² arises because the complete set of states is generated in a nonlinear, e² dependent way. In particular, comparing the present theory with the theory of unitary representations of the Lorentz group by Gelfand, Graev, and Vilenkin, one finds the unitarity condition 0 < e²/khc < π.     

Raman and resonance-Raman spectra of CsI/I−3

Raman and resonance-Raman spectra of the I^?₃ ion isolated within CsI crystals have been studied using 647 nm and 488 nm exciting radiation. Sample temperatures between 300 and 20 K have been used. Eleven overtones of the symmetric stretching mode (nν₁) have been observed in the resonance-Raman spectrum excited by the 488 nm Ar⁺ laser line. Bands centred at 153, 170, 264 and 304 cm^?1 have been assigned as ν₃, 2ν₂, ν₁+ν₃ and 2ν₃(Σ⁺) respectively. The remaining structure between the nν₁ lines has been assigned as due to combinations of these lines with the lattice vibrations of the CsI crystal.