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.     

Stereoselective iodocyclopropanation of terminal alkenes with iodoform, chromium(II) chloride, and N,N,N',N'-tetraethylethylenediamine

Chemoselectivity of a reagent for (E)-olefination of aldehydes derived by reduction of iodoform with chromium(II) chloride in THF changes markedly by addition of TEEDA (N,N,N',N'-tetraethylethylenediamine), and trans-iodocyclopropanes are produced stereoselectively from terminal alkenes by treatment with the base-added reagent system. The iodocyclopropanation occurs only at terminal double bonds, and di- and trisubstituted double bonds in the same molecules remained unchanged. Such functional groups as alcohol, ether, silyl ether, ester, tertiary amine, and amide groups are compatible with the reaction conditions.     

Structure and properties of Bi2Sr2CaCu2Ox/Bi2Sr2CuOx superlattices prepared by RF magnetron sputtering

We have prepared Bi₂Sr₂CaCu₂O_x/Bi₂Sr₂CuO_x (2212/2201) superlattices with various stacking periodicity by multitarget RF magnetron sputtering. Their crystal structure and electrical properties were investigated. The superlattice was found to be successfully constructed from the data of XRD patterns, AES, etc. The critical temperature increased almost linearly with increasing thickness of the 2212 phase up to a thickness of 6 unit cells. On the other hand, it did not decrease as the thickness of the 2201 layers was increased. The unit cell/unit cell superlattice showed T_{c zero} of 30 K.     

Interaction potentials between point defects in aluminum

Interaction potentials between point defects, vacancy-vacancy, vacancy-Zn impurity, vacancy-Mg impurity, Zn impurity-Mg impurity, Zn impurity-Zn and Mg impurity-Mg impurity, have been calculated in aluminum.     

Localized modification of magnetic properties in 304 stainless steel foil by MeV ion beams

MeV ions were implanted in 304 stainless steel foils to investigate the localized modification of the magnetic susceptibility associated with the phase transformation. The magnetic susceptibility was found to be increased by Au⁺ or Si⁺ implantation because of the localized formation of a martensitic phase. The magnetic susceptibility of ferromagnetic substrates was enhanced much more than that of non-magnetic substrates. The enhancement in the magnetic susceptibility for Au⁺-implanted samples was a factor of 4–5 greater than that for Si⁺-implanted samples.On leave from GLORY Ltd., Simoteno, Himeji, Hyogo 670, Japan     

Comparison of laser-induced etching behavior of III–V compound semiconductors

Laser-induced maskless etching of III–V compound semiconductors (InSb, GaAs, and InP) in a KOH aqueous solution by irradiation with a focused argon-ion laser has been investigated to obtain high etching rates and aspect ratios of etched grooves. The etching rate at low laser power was found to depend on the carrier density of the sample and its type. With the increase of the laser power, the etching reaction becomes primarily a thermochemical reaction. High etching rates and aspect ratios have been achieved with a single scan of the laser beam. The damage induced by laser wet etching is less than that by laser dry etching, and the damage at the etched side wall is less than that at the etched bottom. Grooves with locally controlled depth and slab structures have been fabricated for application.     

Simplicity of crossed products of GCR algebras by abelian groups

Mathematische Annalen -     

Velocity measurement of the diffuse object based on time-differentiated speckle intensity fluctuations

This paper proposes a new velocity measuring method for a moving diffuse object on the basis of the autocorrelation of time-differentiated speckle intensity fluctuations. The theoretical background and experimental verification of this method are given. The correlation length of time-differentiated speckle intensity fluctuations is defined by the point at which the correlation becomes zero. By means of the correlation length the object velocity is found to be accurately measured.     

Contrast of time-averaged image speckle pattern for a vibrating object

In vibration analysis by speckle photography it is qualitatively known that the contrast of speckle patterns averaged in the exposure time varies, depending on the object motion. In this paper, the contrast of time-averaged image speckle patterns is theoretically evaluated and found to be determined by the ratio of the sinusoidally oscillating amplitude of the object motion to the average size of static speckles. An effect of the film response on the contrast of time-averaged speckle patterns is also studied.