Chromatographic separation and identification of human urine components

Summary Ultraviolet-absorbing components of human urine were separated by HPLC with a large scale column (250 × 28 mm I.D. stainless-steel) containing a macroreticular type strongly basic anion-exchange resin. The sample was eluted with a linear gradient of 0.006 M to 6.0 M ammonium acetate buffer (pH 4.40) and different fractions were collected. The identification of one compound using ultraviolet, infrared and mass spectral data is illustrated; it was found to be uric acid.     

Self-reversal phenomena of toroidal current by reversing the external toroidal field in helicity-driven toroidal plasmas

In order to understand self-organization in helicity-driven systems, we have investigated the dynamics of low-aspect-ratio toroidal plasmas by decreasing the external toroidal field and reversing its sign in time. Consequently, we have discovered that the helicity-driven toroidal plasma relaxes towards the flipped state. Surprisingly, it has been observed that not only toroidal flux but also poloidal flux reverses sign spontaneously during the relaxation process. The self-reversal of the magnetic fields is attributed to the nonlinear growth of the n=1 kink instability of the central open flux.     

Seed polymerization of tetraethyl orthosilicate in the presence of anionic and cationic polystyrene colloidal spheres

Kinetic analyses are made for the seed polymerization of tetraethyl orthosilicate (TEOS) in the presence of anionic and cationic polystyrene colloidal sphere seeds by turbidity and dynamic light-scattering measurements. Transmission-electron microscopy pictures of the spheres formed are also used. The seed polymerization of TEOS is difficult to take place on the surface of anionic polystyrene spheres (44–212 nm in diameter). On the other hand, the reaction proceeds easily on the cationic polystyrene spheres. Hairy and soft surfaces of polystyrene spheres will disturb the seed polymerization. Furthermore, the electrostatic attraction between the anionic hydrolytic products of TEOS molecules and cationic polystyrene spheres plays an important role for the seed polymerization.     

Hypernuclear properties derived from the Jülich hyperon-nucleon interaction (in comparison with the Nijmegen interactions)

TheG-matrix interactions are derived from the Jülich YN interaction models A and B, and compared with those from the Nijmegen models. The DDHF calculations for heavy A hypernuclei and the shell-model analysis for spin-doublet states of light hypernuclei are performed by use of theG-matrix interactions. It is demonstrated that the OBE models can be tested by the hypernuclear calculations.     

Angular distribution of electrons injected through a quantum point contact

This paper reports on the measurement of the angular distribution of electrons injected through a quantum point contact. We observed double peaks in the distribution with the point contact quantized in two modes. Our calculation of the distribution using an approximation of Fraunhofer diffraction through a quantized single slit agreed well with results. This paper also discusses the interference between the first and second modes, and shows how the terms of interference in the angular distribution are canceled.     

Decomposition of chlorofluorocarbons and hydrofluorocarbons in water by ultrasonic irradiation

The sonochemical degradation of CFC-113 (F₂ClC---CCl₂F), HCFC-225ca (F₃C---CF₂CCl₂H), HCFC-225cb (F₂ClC---CF₂---CClFH) and HFC-134a (F₃C---CF₂H) in water was investigated. The decomposition rates of CFC-113 increased with increasing the concentration of the CFC and at high concentration the rates far exceeded the rate of OH radical formation by water sonolysis, and OH radicals seemed to have little effect on the decomposition. The pyrolysis in the cavitation bubbles was suggested.     

Binodal curve of two liquid phases and solid-liquid equilibrium for water + fatty acid + ethanol systems and water + fatty acid + acetone systems

To determine the liquid-liquid-solid three-phase equilibrium (LLSE), binodal data of the liquid-liquid equilibrium (LLE) and the solid-liquid equilibrium (SLE) have been measured for the ternary water + acetone or ethanol + lauric acid, myristic acid or palmitic acid systems. The binodal region for two liquid phases increases successively in the following order of the third component: lauric acid < myristic acid < palmitic acid. The binodal regions of the ternary systems with acetone as the second component are larger than those for ethanol. These binodal curves are not highly sensitive to temperature. The isothermal solubility of these fatty acids is considerably reduced when the water content in the aqueous phase increases. The solubility of fatty acids is successively reduced in the following order: lauric acid > myristic acid > palmitic acid. The solubility of fatty acids in aqueous solutions containing acetone is smaller than in those containing ethanol. Predictions of both the binodal curve for LLE and the SLE curve by the UNIFAC method and the NRTL equation do not represent the experimental data. However, data of the binodal curve and solubility are well correlated by the NRTL equation, and also the LLSE relationship could be represented.