237Np and 57Fe Mössbauer study of NpFeGa5

⁵⁷Fe and ²³⁷Np Mössbauer ōmeasurements have been performed for NpFeGa₅, which is one of the so-called neptunium 1-1-5 compounds. The ⁵⁷Fe Mössbauer spectra below T _N = 118 K show the magnetically ordered state. The magnitude of the hyperfine magnetic field at the ⁵⁷Fe nucleus is determined to be 1.98 ± 0.05 T at 10 K. From the ²³⁷Np Mössbauer spectrum at 10 K, the hyperfine magnetic field at the ²³⁷Np nucleus is 203 T and the hyperfine coupling constant is determined to be 237 T/μ_B using the Np atomic magnetic moment of 0.86 μ_B determined by the neutron diffraction study.     

Enzymatic generation of alloxan radicals in rat liver microsomes: possible participation of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P-450 reductase.

Electron spin resonance studies showed that addition of rat liver microsomes to the reaction system of alloxan with reduced nicotinamide adenine dinucleotide phosphate (NADPH) resulted in a marked increase in the generation of alloxan radicals (AH.), whereas heat-denatured microsomes were without such effect. Oxidation of NADPH by alloxan was also stimulated by microsomes. The microsomes from rats treated with phenobarbital, an inducer of cytochrome P-450 reductase, greatly stimulated both the AH.generation and the NADPH oxidation. However, the microsomes from rats treated with 3-methylcholanthrene, an inducer of DT-diaphorase, did not have stimulative effect greater than the control microsomes. These results suggest the possibility that NADPH-linked AH.generations in microsomal membranes is catalyzed by NADPH-cytochrome P-450 reductase.     

The frequency distribution functions of the crystalline,amorphous and liquid iron

The atomic vibrations in crystalline, amorphous and liquid iron are discussed based on the realistic models simulated in a computer. The frequency distribution functions of amorphous and liquid iron are of double peak and a single peak, respectively.     

Microdetermination of serum iron and of iron-binding capacity by precision photometry

Summary Use is made of the high stability of the photometric system of the Enzyrator. This stability, together with the possibility of multiplying the read-out by a factor of 10, make it possible to decrease the sample size by the same factor.

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Zusammenfassung Die besondere Stabilität der photometrischen Anzeige des Enzyrators sowie die Möglichkeit, die Anzeige zu verzehnfachen, bieten die Voraussetzung, die Probengröße um denselben Faktor zu verkleinern.

     

Unique spin dynamics and unconventional superconductivity in the layered heavy fermion compound CeIrIn5: NQR evidence

We report measurements of the 115In nuclear spin-lattice relaxation rate ( 1/T1) between T = 0.09 and 100 K in the new heavy fermion (HF) compound CeIrIn5. At 0.4 < or = T< or = 100 K, 1/T1 is strongly T-dependent, which indicates that CeIrIn5 is much more itinerant than known Ce-based HFs. We find that 1/T1T, subtracting that for LaIrIn5, follows a (1 / T+straight theta)3/4 variation with straight theta = 8 K. We argue that this novel feature points to anisotropic, due to a layered crystal structure, spin fluctuations near a magnetic ordering. The bulk superconductivity sets in at 0.40 K below which the coherence peak is absent and 1/T1 follows a T3 variation, which suggests unconventional superconductivity with line-node gap.     

Experimental analysis of turbulent flow structure in a fully developed rib-roughened rectangular channel with PIV

An experimental study was carried out to investigate the turbulent water-flow structure over one-side micro-repeated ribs in a narrow two-dimensional rectangular channel by particle image velocimetry (PIV). Two rib pitch-to-height ratios p/k of 10 and 20 were investigated while the rib height was held constant at 4 mm. The rib height-to-channel equivalent diameter ratio k/D_e was 0.1. The streamwise mean velocity and turbulent kinetic energy fields in the fully developed flow region of the channel were calculated at three different positions of x=0, 3.8, and -6.2 mm, which corresponded to center, downstream, and upstream of the rib, respectively, and for two Reynolds numbers Re of 7,000 and 20,000. A large-scale turbulent eddy was generated by the rib promoter and then propagated into the mainstream flow, which led to the deformation of the velocity profile. Downstream of the rib, rotating and counter-rotating eddies were also generated by the rib promoter. The enhancement of the turbulent kinetic energy was not changed when the Reynolds number increased from 7,000 to 20,000 between p/k=20 and 10. The reattachment length L_R was measured from velocity vector fields in the developing, fully developed, and exit regions of the flow over the range Re=1,400-50,000. The results showed that the ratio p/k and the Reynolds number had no significant effect on the reattachment length beyond a critical value of Re=15,000, where L_R was found to be approximately 4 times the rib height.     

First Synthesis and Properties of Calix[4]arene with Two Alternately Arranged Phloroglucinols and Two p-tert-Butylphenols

The Calix[4]arene 1 including two alternately arranged phloroglucinols and p-tert-butylphenols was synthesized via the “3+1” coupling procedure, and its pKa values were estimated to be 3–4 and 7.5, while those of the other six phenolic hydroxyls were approximately 11. Its UV–vis spectrum at pH 11 and ¹H and ¹³C NMR spectra in NaOD-D₂O solution (pH 12.8) showed a dramatic change like those of the phloroglucinol when compared to those in acidic or neutral solution, which suggests a change in the phloroglucinol moiety to the keto-form. During the solvent extraction for alkali metal species using 1, Li⁺ was only extracted in the low yield of 15% at pH 11. The cyclic voltammetry study of 1 was used to compare it with the phloroglucinol and p-tert-butylphenol. The redox potential of the corresponding two phloroglucinols was observed in 1.     

SIMPLE METHOD FOR THE SYNTHESIS OF STANNOLE DIANION

Reduction of 1-t-butyl-1,2,3,4,5-pentaphenylstannole by lithium gave the stannole dianion. Reduction of the bi(1,1-stannole) having a t-butyl group on the tin by lithium also gave the stannole dianion, the formation of which was evidenced by spectral analysis and chemical trapping reaction.