Grazing scattering of 1-2 MeV HeH ions from KCl(0 0 1): Effect of surface track potential

Three dimensional (3D) distributions (energy E, scattering angle θ and azimuth angle φ) of the fragment protons dissociated from HeH⁺ during grazing angle scattering from a KCl(0 0 1) are measured using a magnetic spectrometer in order to study the effect of the surface track potential. The distributions of the fragment protons scattered from a SnTe(0 0 1) are also measured as a reference. Although the observed distributions for KCl(0 0 1) and SnTe(0 0 1) are basically the same, there is small differences, especially in the scattering angle distribution. While the fragment protons are scattered at the specular angle from SnTe(0 0 1), the protons are scattered at slightly larger angles from KCl(0 0 1). The observed angular shift is more pronounced for the trailing protons than the leading protons. It is also found that the angular shift increases with decreasing ion energy. The observed angular shift can be qualitatively explained by the surface track potential induced by the partner He ions using a simple model of the surface track potential.     

Estimation of the Hydromotive Source Pressure from Ejecting Beats of the Left Ventricle

The relationship between peak isovolumic developed pressure (Pmax) and end-diastolic volume can indicate ventricular contractility. Therefore, we propose a practical method to estimate Pmax from the pressure curve of an ejecting contraction of left ventricle. For the estimation, we first considered the left ventricle a linear time varying hydromotive pressure source (HMP(t)) coupled in series with an internal impedance. To formulate the HMP(t) we Fourier analyzed isovolumic pressure curves obtained under various conditions in six dogs. Since the higher order harmonics were found to be very small, HMP(t) could be described simply as where Pd = end-diastolic pressure and w = 2/T in which T is duration of contraction. Finally, HMP(t) for ejecting contraction was estimated by fitting the equation to the isovolumic portions of the pressure curve of ejecting contractions. The estimated Pmax values correlated well with actually observed Pmax values (r = 0.951, N = 24). We conclude that the proposed technique can be used to estimate Pmax from a single ejecting beat.     

Improvements in time resolution and signal-to-noise ratio in a compact pico-second pulse radiolysis system

A compact pico-second pulse radiolysis system has been developing at Waseda University for studying primary processes in radiation chemistry. The system is composed of a photo-injector system and a pico-second all-solid-state laser system. An infrared (IR) and an ultraviolet (UV) laser pulses are obtained from mode-locked Nd:YLF laser system and used for generation of the white light continuum as a probe light and the irradiation to the Cu cathode of a photo-cathode RF-gun, respectively. To improve signal-to-noise (S/N) ratio and time resolution of this pulse radiolysis system, we optimized both probe light and pump electron beam. As a result, our pico-second pulse radiolysis system has been enough to study the primary processes of radiation chemistry. The experimental results and the improvements of our system are described in this paper.     

cis-Vaccenic acid in pulp lipids of commonly available fruits

Fatty acids of commonly available fruit pulps have been analyzed by capillary gas chromatography of their methyl esters and by gas chromatography-mass spectrometry as their dimethyl disulfide adducts. The gas chromatographic and mass spectrometric data proved that these fruits always containedcis-vaccenic (cis-11-octadecenoic) acid as a component fatty acid of their pulp lipids. The concentration ofcis-vaccenic acid in total octadecenoic acids ranged from 1.9% to 95.1% in the fruit pulps examined. The highest concentration of this acid was detected in pulp lipids of Japanese persimmon (Diospyros kaki). In fruit pulp lipids,cis-vaccenic acid was a common octadecenoic acid as well as oleic acid.     

Selective separation of water from water–ethanol solution through quarternized poly(4-vinylpyridine-co-acrylonitrile) membranes by pervaporation technique

Polymer membranes having cationic charge site, poly(1-alkyl-4-vinylpyridinium iodide-co-acrylonitrile) (alkyl: methyl, butyl, or octyl) were prepared in terms of coulombic interaction for separation of water–ethanol mixtures. The incorporation of cationic charge site into the membrane led to improve not only separation factors (selectivity toward water) but also flux number in the separation of aqueous ethanol solution by pervaporation technique. Target values, which were requested to have from the viewpoint of industrial utilization for separation of aqueous ethanol solution were attained as follows: separation factor toward water over 50 and flux value over 500 g m^?2 h^?1, through poly(1-methyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 3 ) (quarternized fraction of pyridinium moiety, 89.5%; mol fraction of pyridinium moiety, 0.034) and poly(1-butyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 5 ) (quarternized fraction, 100%; mol fraction of pyridinium moiety, 0.038). It was found that the introduction of cationic charge site into the membrane was one of feasible methods to obtain suitable membranes for water permselective membranes in the separation of water–ethanol mixtures.     

Ammonia decomposition to clean hydrogen using non-thermal atmospheric-pressure plasma

The plasma decomposition of ammonia was studied as a function of applied voltage/power, residence time including length of an inner electrode and flow rate of reactant gases, partial pressure of ammonia, and amount and the metal species of the inner electrodes. The ammonia decomposition rates were in excellent agreement with the hydrogen production rates and no hydrazine production was detected, indicating the clean decomposition of ammonia in the current system. The decomposition rates were dependent on the applied power and the residence time and independent of metal species of the inner electrodes, in contrast to the strong dependence of the ammonia synthesis reaction on the metal species. A hydrogen yield of 100% was achieved with an applied power of approximately 50 W and a residence time of 1.2 s at ambient temperature and atmospheric pressure, with an applied voltage of 5 kV and a frequency of 50 kHz.