Response of epoxy oversized models of strands to axial and torsional loads

As part of an extensive investigation on strand and cable properties, epoxy oversized models of strands have been manufactured using a newly developed technique. Axial and torsional loadings have been applied to the models. Strains, stresses and displacements have been determined using mechanical and electrical strain gages, dial gages and brittle coatings. The results obtained are compared with calculations using a previously developed theory. The response of a reference structure in which each wire is assumed to act independently is also compared with the response of the strand. Several discrepancies with theory are pointed out. It is believed that these are the first systematic measurements taken on strands.     

Anomalous excimer formation of a pyrenyl derivative having a mesogen group of alkoxycyanobiphenyl in its smectic mesophase

The direct photolysis of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in aqueous solution was investigated under monochromatic ultraviolet (UV) irradiation at 254 nm. ABTS was found to be directly photolyzed by UV irradiation to yield the one-electron oxidized radical, ABTS⁺, which is a blue-green colored persistent radical species that has strong visible absorption bands. The photochemical production of ABTS⁺ was strongly dependent on the solution pH and the presence of dissolved oxygen. The presence of dissolved oxygen increased the quantum yields at pH 3, whereas it inhibited the production of ABTS⁺ at pH 6.5. Spectrophotometric and spectrofluorometric data indicated that ABTS photolysis may occur as a result of the transfer of one-electron between the singlet excited state and the ground state of ABTS. Observations made during UV/H₂O₂ experiments with ABTS suggested that the dependence of the photoloysis of ABTS on the solution pH and the presence of dissolved oxygen is related to the role of the hydroperoxyl/superoxide radical (HO₂/O₂⁻), which appears to be formed via a secondary reaction of the reduced intermediate of ABTS with dissolved oxygen. The proposed photolytic reactions were supported by the observed stoichiometry between the amount of ABTS⁺ radicals produced and the amount of ABTS molecules decomposed.     

Superconducting Pb island nanostructures studied by scanning tunneling microscopy and spectroscopy

Superconductivity of nanosized Pb-island structures whose radius is 0.8 to 2.5 times their coherence length was studied under magnetic fields using low-temperature scanning tunneling microscopy and spectroscopy. Spatial profiles of superconductivity were obtained by conductance measurements at zero-bias voltage. Critical magnetic fields for vortex penetration and expulsion and for superconductivity breaking were measured for each island. The critical fields depending on the lateral size of the islands and existence of the minimum lateral size for vortex formation were observed.     

Anomalous Josephson vortex solutions in Josephson junctions with multiple tunneling channels

We construct a theory for Josephson junction with multiple tunneling channels. We focus on two situations, i.e., a heterotic junction composed of two-gap-superconductor, insulator, and one-gap-superconductor, and a grain-boundary junction formed by two identical multi-gap superconductors. Then, we show that the magnetic field distribution of the Josephson vortex for ±s-wave superconductivity is much more enlarged than that for s-wave without sign change between the order parameters. We display such anomalous vortices and suggest how to evaluate the enlargement.     

Near-infrared spectra of formamide and its anharmonic potential

The near-infrared spectra of formamide and its N- and C-deuterated compounds in chloroform solutions were investigated and a perturbation calculation of the vibrational levels of these isotopic formamides was carried out. The trans-interaction constant and the cubic cross-term constants between the NH stretching and the CNH bending coordinates were found to be necessary to reproduce observed frequencies. The stretching potentials of the trans- and the cis-NH bonds show close correspondence with those of the free and the bonded NH bonds of o-bromoaniline. The correlation between the compliance constants and the change of the CH, CO, and NH bond lengths on the dissociation of the CN bond is discussed.