Coprecipitation with yttrium phosphate as a separation technique for iron(III), lead, and bismuth from cobalt, nickel, and copper matrices

The coprecipitation behavior of 44 elements (47 ions because of chromium(III,VI), arsenic(III,V), and antimony(III,V)) with yttrium phosphate was investigated at various pHs. Yttrium phosphate could quantitatively coprecipitate iron(III), lead, bismuth, and indium over a wide pH range; however, 18 ions, including alkali metals and oxo anions, such as vanadium(V), chromium(VI), molybdenum(VI), tungsten(VI), germanium(IV), arsenic(III,V), selenium(IV), and tellurium(VI), were scarcely collected. In addition, 19 ions, including cobalt, nickel, and copper(II), were hardly coprecipitated at pHs below about 3. Based on these results, the separation of iron(III), lead, and bismuth from cobalt, nickel, and copper(II) matrices was investigated. Iron(III), lead, and bismuth ranging from 0.5 to 25 μg could be separated effectively from a solution containing 0.5 g of cobalt, nickel, or copper at pH 3.0. The separated iron(III), lead, and bismuth could be determined by inductively coupled plasma atomic emission spectrometry using internal standardization. The detection limits (3σ, n = 7) of iron(III), lead, and bismuth were 0.008, 0.137, and 0.073 μg, respectively. The proposed method was applied to the analyses of metals and chlorides of cobalt, nickel, and copper.     

Direct preparation of allylic indium(III) reagents from allylic alcohols via a reductive transmetalation of pi-allylnickel(II) with indium(I) iodide

InI-mediated direct allylation of carbonyl compounds with allylic alcohols proceeded smoothly with catalytic amounts of Ni(acac)(2) and PPh(3) to give the corresponding homoallylic alcohols in high yields. Allylindium compounds were shown to be the real allylating agents in the present system. Substituted allylic alcohols gave branched homoallylic alcohols with syn-selectivity irrespective of the geometry of the starting allylic alcohols, whereas high anti-selectivity was observed when a bulky substituent is present in the allylic alcohols. The outcome of the diastereoselectivity is discussed on the basis of the reaction mechanism, comparing with the corresponding Pd-catalyzed version. Another distinct behavior between the Ni- and Pd-catalyzed allylation was demonstrated in the reaction of hex-1,5-diene-3,4-diol derivatives: the Pd catalyst did not give any coupling product, whereas the Ni-catalyzed InI-mediated reaction with benzaldehyde afforded the 1:1 and 1:2 adduct diols selectively depending on the reaction conditions.     

Precise measurement of the magnetic moment of doubly closed shell + 1 nucleon nucleus17F(I π=5/2+,T 1/2=64.5 s)

Hyperfine interactions of -emitting¹⁷F implanted in single crystals of NaF and CaF₂ were studied. The nuclear magnetic moment of theI =5/2⁺ state was determined with improved precision to be |(¹⁷F;I =5/2⁺,T _1/2=64.5s)|=4.72130±0.00025 µ_N.     

Super-Derivations and Associated Standard Super-Potentials

Abstractly defined super-derivations on Fermionic systems on a lattice are studied. The existence and uniqueness of the associated standard super-potential are shown for every super-derivation with the subalgebra of all local operators as its domain. The relation between the standard super-potential of a super-derivation and the standard potential for the square of the super-potential (which is shown to be a derivation in the case of finite range super-potentials) is obtained (by use of local super-Hamiltonian for the super-derivation and local Hamiltonian for the square). As a consequence, a necessary and sufficient condition for a super-derivation to be nilpotent is obtained in terms of the corresponding standard super potential. Examples of translation invariant nilpotent super-derivations are given in the case of super-potentials of finite ranges on a one-dimensional lattice. A merit of considering the super-potential associated with a super-derivation is that the former can be used as free parameters for the latter.     

In-situ cyclic pulse annealing of InN on AlN/Si during IR-lamp-heated MBE growth

To improve crystal quality of InN, an in-situ cyclic rapid pulse annealing during growth was carried out using infrared-lamp-heated molecular beam epitaxy. A cycle of 4 min growth of InN at 400 °C and 3 s pulse annealing at a higher temperature was repeated 15 times on AlN on Si substrate. Annealing temperatures were 550, 590, 620, and 660 °C. The back of Si was directly heated by lamp irradiation through a quartz rod. A total InN film thickness was about 200 nm. With increasing annealing temperature up to 620 °C, crystal grain size by scanning electron microscope showed a tendency to increase, while widths of X-ray diffraction rocking curve of (0 0 0 2) reflection and E₂ (high) mode peak of Raman scattering spectra decreased. A peak of In (1 0 1) appeared in X-ray diffraction by annealing higher than 590 °C, and In droplets were found on the surface by annealing at 660 °C.     

Degradation mechanism of scandia-stabilised zirconia electrolytes: Discussion based on annealing effects on mechanical strength,ionic conductivity,and Raman spectrum

In the present study, the mechanical strength as well as the ionic conductivity of the scandia- and ytterbium oxide-codoped zirconia electrolyte is investigated during annealing. Based on the annealing effect on both properties, the degradation mechanism is discussed. The X-ray diffraction and Raman spectroscopic analyses confirmed that annealing enhanced the tetragonal phase content in the samples which initially contained the tetragonal phase. The samples with the rhombohedral phase showed no phase changes. The samples initially with the tetragonal phase showed a significant decrease in the conductivity but an increase in the strength whereas the samples with the rhombohedral phase generally showed no change and the ones with the cubic phase showed slight decreases in both properties. From above results, the conductivity degradation of the sample with the tetragonal phase was attributed to two causes: the formation of low conductive but transformable t-phase from the high conductive t′-phase and the formation of t′-phase from the t″-phase. The annealing effect was little for the samples initially with rhombohedral phase and complex for the ones with cubic phase.     

Phase-Modulation Fluorometer Using an Ultraviolet Light-Emitting Diode

We have constructed a phase-modulation fluorometer using a commercially-available ultraviolet light-emitting diode (UV LED) as an excitation light source. The center wavelength of the UV LED is 370 nm and its spectral bandwidth is 10 nm. A 10 mApp modulation-current was superimposed on a bias current of 5 mA with a fixed frequency in the range of 1-20 MHz. The average UV power on the sample was 250 μW. The fluorescence signal was detected by a photomultiplier tube and was fed into a versatile digital oscilloscope. The phase difference between the fluorescence signal and the reference signal obtained from a diffusion plate was directly read out using the operational functions of the digital oscilloscope. To demonstrate the system performance, fluorescence lifetimes of 25 ppm rhodamine 6G in ethanol and of 10 ppm quinine sulfate in 0.1 N H₂SO₄ were measured. The calculated lifetimes of 5.8 ns and 19.1 ns, respectively, agreed with those reported in the literature. The combination of the UV LED and the digital oscilloscope made the fluorometer simple and easy to construct with low cost.     

Phosphotransacetylase as a key factor in biological production of polyhydroxybutyrate

Phosphotransa cetylase (Pta) catalyzes the reversible conversion of, acetyl-coenzyme A (CoA) to acetyl phosphate. Polyhydroxybutyrate (PHB) synthase and accumulation were compared between a Pta-deficient mutant and the wild-type Escherichia coli, which were transformed with pAE100, coding for 3-ketothiolase, NADPH-dependenta cetoacetyl-CoA reductase, and PHB synthase from Ralstonia eutropha. During the growth period, PHB synthase activity in the Pta-deficient mutant was lower than that in the wild type. PHB accumulation in the Pta-deficient mutant, however, was higher than that in wild-type cells grown in Luria-Bertani (LB) medium containing 1% glucose (high C:N ratio). The Pta-deficient mutant showed PHB accumulation even in LB medium (low C:N ratio), whereas wild-type cells showed no PHB accumulation. These data suggest the activation of PHB synthase by acetyl phosphate that is synthesized by Pta. A decrease in Pta activity probably causes some increase in acetyl-CoA as substrate for the PHB synthesis pathway, resulting in increased PHB accumulation.     

Identification of ammonia in gas emanated from human skin and its correlation with that in blood.

Identifying and measuring the ammonia gas that emanates from human skin, which we called skin gas, has been achieved using a modified gas chromatographic system with a nitrogen-selective detector (flame-thermoionic detector: FTD). The skin gas is collected with a home-made sampling probe or bag, which is used to cover the skin surface of a subject's wrist, or a finger, for 5 min. It was proved that ammonia was present in skin gas for healthy persons and patients with hepatic disease. The average amounts of ammonia were 1.7 +/- 0.4 and 2.7 +/- 0.8 ng/cm2; furthermore, there was a significant difference between them (p < 0.05). In addition, the ammonia levels present in skin gas were correlated with that in blood (r = 0.64, p < 0.05).