Measurement of the elastic magnetic form factor of (3)He at high momentum transfer.

New electron scattering measurements have been made that extend data on the (3)He elastic magnetic form factor up to Q(2) = 42.6 fm(-2). These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as 10(-40) cm(2)/sr, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data.     

Sequential collection of selenium(IV) and selenium(VI) by the use of an anion-exchange resin loaded with bismuthiol-II sulphonic acid

A new ligand-loaded anion-exchange resin has been developed which allows determination of Se(VI) and Se(IV) in mixtures of the two. The ligand is a sulphonic acid derivative of bismuthiol-II.     

Time evolution of electron wave-packets in modulated superlattices and at their boundaries

Time evolution of an electron wave-packet moving perpendicular to a superlattice surface is calculated by numerically solving the Schrödinger differential equation. Reflections and penetrations of the wave-packets at the superlattice surface are shown. Low transmission efficiency is observed when the potential discontinuity between two component semiconductors of the superlattice is large, even though the electron impinging energy is in the allowed mini-band of the superlattice. An “anti-reflection coating” which removes this reflection is discussed. The effect of layer-thickness fluctuation on the electron scattering is also simulated by this method. It is found that a fluctuation model of no correlation with neighboring layers produce a scattering rate which strongly depends on the random number sequence used to generate the fluctuation.     

On the anomalous temperature dependence of ferroelectric Sc*. liquid crystals

A biaxial elastic model for the temperature dependence of S_c* helical pitch is proposed on the basis of a phenomenological theory of S_c* liquid crystals accompanied by a biaxial molecular ordering playing an important role for the anomalous behaviour of the helical pitch near the S_c*-S_A transition point. In the S_c*. phase of p-(n-decyloxybenzylidene)-p-amino-(2-methylbuthyl)-cinnamate (DOBAMBC), a qualitative agreement with the observed helical pitch is found by choosing a few material parameters concerned with a biaxial elasticity and an anisotropy of the elastic constants.     

Total synthesis of (+)-tryptoquivaline

We report the first total synthesis of (+)-tryptoquivaline 1a and of a key precursor, 2,3-dialkylquinazolinone 13b.     

Sound radiation from a circular cylinder subjected to elastic collision by a sphere

Sound radiation from a steel cylinder impacted by a steel sphere from the longitudinal or the transverse direction is studied. In order to analyze the vibration of the cylinder, Hertz's theory is incorporated to obtain an approximate value of the contact force. The influence of the impact speed and the slenderness of the cylinder on the radiation of sound waves from the vibrating cylinder is analyzed. An experimental apparatus was constructed and vibrations of the cylinder as well as the acoustic pressure radiated were measured to demonstrate the analytical results. It is shown that, no matter whether dispersion in the wave propagation in the impacted cylinder is significant as in the case of a transverse impact, or not as in the case of a longitudinal impact, a decaying sound pulse is predominantly generated by the rigid motion of the cylinder provided that the product of the contact time T and the fundamental natural frequency of the cylinder ω₁i.e., ω₁T, is larger than 4π, while a periodic sound due to the free vibration of the cylinder is predominant provided that ω₁T is smaller than 4π.     

Exergy analysis of a pervaporation system and its combination with a distillation column based on an energy utilization diagram

Based on an energy utilization diagram, energy and exergy analysis of a pervaporation system is performed by taking three subsystems into account, supply of heat, pervaporation, and suction. By this single diagram, the energy balance, the exergy loss in each subsystem, and the strength of forces driving processes can be disclosed. Energy transformation in the pervaporation system and the effects of manipulating variables are clarified by comparison with a distillation system. The energy utilization diagram is also applied to examine a system in which a pervaporator and a distillation column are combined. It is shown that separation by pervaporation is quite effective from the viewpoint of exergy, especially when the pervaporation system can proceed by the difference between the temperature of the feed liquid and that of the cooling water only. This is because in this case low-grade energy is utilized completely.