Cobalt oxide (Co3O4) nanorings prepared from hexagonal β-Co(OH)2 nanosheets

Hexagonal cobalt hydroxide (β-Co(OH)₂) nanosheets over a size range from 100 nm to 1 μm were synthesized using a very simple hydrothermal route with cobalt naphthenate as the cobalt source. Additionally, hexagonal cobalt oxide (Co₃O₄) nanorings over a size range from 100 nm to 1 μm consisting of cubic nanocrystals were obtained via a hydrothermal method using as-prepared β-Co(OH)₂ nanosheets as the precursors. A probable mechanism of formation of the hexagonal Co₃O₄ nanorings is proposed on the basis of time-dependent experimental results.     

Ni(2+) and H(2)PO(4)(-) uptake properties of compounds in the CaTiO(3)-CaFeO(2.5) system

A batch method was used to investigate the uptake of heavy metal cations and anions by the compounds in the CaTiO(3)-CaFeO(2.5) system, in which a series of oxygen vacancies was systematically introduced into a perovskite structure as the x-value of Ca(Fe(x)Ti(1-x))O(3-x/2) was increased. Samples of CaTiO(3), CaFe(0.1)Ti(0.9)O(2.95), CaFe(0.5)Ti(0.5)O(2.75), CaFe(0.67)Ti(0.33)O(2.67) and CaFeO(2.5) were prepared by solid mixing (SM), co-precipitation (CP) and gel evaporation (GE) methods. The resulting samples were calcined at temperatures between 400 and 1000 °C. The target crystalline phases differed according to the preparation method, but in most cases were formed at 700-800 °C. The Ni(2+) sorption isotherms of all the samples were fitted better by the Langmuir model than by the Freundlich model, while in the case of H(2)PO(4)(-) sorption isotherms, these were better fitted by the latter model. The uptake ability increased with increasing x value of the samples. The maximum values for the saturated sorption of Ni(2+) (Q(0)(Ni(2+)) = 2.83 mmol/g) and H(2)PO(4)(-) (K(F)(H(2)PO(4)(-)) = 2.95 mmol/g) were achieved for x = 1 (i.e. CaFeO(2.5)) sample.     

Radical-initiator-Induced solid-state polymerization of butadiyne nanocrystals in water and their dispersion stabilization

Butadiyne nanocrystals in water are usually polymerized by UV or gamma-ray irradiation to give polydiacetylene (PDA) nanocrystals. In this study, we confirmed that solid-state polymerization of 1,6-di(N-carbazolyl)-2,4-hexadiyne (DCHD) and 5,7-dodecadiyn-1,12-diyl bis[N-(butoxycarbonyl-methyl)carbamate] (4BCMU) could be stimulated by water-soluble radical initiators. The radical initiators used were potassium peroxodisulfate, three kinds of azo-type compounds and a redox initiator. In all cases, the solid-state polymerization was confirmed by color change into blue indicating that PDA modified by the radical residues at the end was formed. However, nanocrystal cohesion occurred especially when the concentration of the initiators was high or the dispersion was kept for a long time. In order to improve the dispersion stability, two kinds of surfactants, i.e., sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium chloride (DTMAC), were added to the DCHD nanocrystal aqueous dispersion. As a result, when anionic SDS was added, the solid-state polymerization of nanocrystals proceeded without coagulation and quantitative conversion was confirmed for all initiators. Cationic DTMAC has no effect on dispersion stabilization. PDA nanocrystal surfaces in water are negatively charged in nature and electric interaction of nanocrystals with the cations results in decrease of surface charge and aggregation of nanocrystals.     

The Nodal SDW Gap and the Superconducting Gap in?BaFe2?x Co x As2

The spin density wave (SDW) transition in BaFe₂As₂ and the superconducting transition in BaFe_1.84Co_0.16As₂ were investigated by Raman scattering. The symmetries of the nodal SDW gap at 400?cm^?1 and the superconducting gap at 75?cm^?1 are both?B _2g. The superconducting coherent peak energy is smaller than the gap energy of the hole pocket, indicating that the peak is the resonant peak in the S _?? superconductor. The superconducting symmetry is given by B _2g in the orbital combination and A _1g (S _??) in the momentum space. The exchange interaction energies are estimated from the two-magnon peak.     

Studies on the nickel-iodine-sulfur process for hydrogen production

A thermochemical process involving nickel, iodine and sulfur (NIS process) has been studied and a major improvement of the efficiency of the process has been made by replacing the solvent extraction step with selective crystallization as a means to separate nickel iodide from nickel sulfate. Rates and equilibria related to steps in the process have been measured, including solubility of the nickel salts, decomposition pressures of hydrous and anhydrous nickel iodide, rate of decomposition of nickel iodide and catalytic decomposition rate of sulfur trioxide. The heat balance of the process was estimated.     

N-nitrosamine rejection by reverse osmosis membranes: A full-scale study

This study aims to provide longitudinal and spatial insights to the rejection of N-nitrosamines by reverse osmosis (RO) membranes during sampling campaigns at three full-scale water recycling plants. Samples were collected at all individual filtration stages as well as at a cool and a warm weather period to elucidate the impact of recovery and feed temperature on the rejection of N-nitrosamines. N-nitrosodimethylamine (NDMA) was detected in all RO feed samples varying between 7 and 32 ng/L. Concentrations of most other N-nitrosamines in the feed solutions were determined to be lower than their detection limits (3–5 ng/L) but higher concentrations were detected in the feed after each filtration stage. As a notable exception, in one plant, N-nitrosomorpholine (NMOR) was observed at high concentrations in RO feed (177–475 ng/L) and permeate (34–76 ng/L). Overall rejection of NDMA among the three RO systems varied widely from 4 to 47%. Data presented here suggest that the feed temperature can influence rejection of NDMA. A considerable variation in NDMA rejection across the three RO stages (14–78%) was also observed. Overall NMOR rejections were consistently high ranging from 81 to 84%. On the other hand, overall rejection of N-nitrosodiethylamine (NDEA) varied from negligible to 53%, which was considerably lower than values reported in previous laboratory-scale studies. A comparison between results reported here and the literature indicates that there can be some discrepancy in N-nitrosamine rejection data between laboratory- and full-scale studies probably due to differences in water recoveries and operating conditions (e.g. temperature, membrane fouling, and hydraulic conditions).     

Laboratory-performance study of the notified methods to detect genetically modified maize (CBH351) and potato (NewLeaf Plus and NewLeaf Y)

To investigate the key factors affecting the reliability of the analytical results, a laboratory-performance study was attempted for the notified methods to detect genetically modified (GM) maize (CBH351) and GM potato (NewLeaf Plus and NewLeaf Y). The test samples were designed as three pairs of blind duplicates, which included 0%, 0.1% and 1.0% GM maize (CBH351) or GM potato (NewLeaf Plus or NewLeaf Y). Fourteen laboratories participated in the study. The test samples were sent to the participating laboratories along with the protocol. The data were collected from all laboratories and statistically analyzed. For the 0% sample of the CBH351 maize, one laboratory reported a false-positive result. It was considered that contamination could have occurred via the common use of equipment or tools for the test. For the 0.1% samples of the NewLeaf Plus potato or NewLeaf Y potato, on the other hand, three laboratories reported false-negative results. It was presumed that these results were due to changes of the conditions of the electrophoresis and agarose-gel staining. The other laboratories reported appropriate results. It was considered that the method employed in this study was suitable for the assessment of laboratory performance.     

Active Mixing in Microchamber using Cilia of Vorticella convallaria

Innovative engineering systems can potentially be developed by using biological motors and artificial structures in combination. In this study, we demonstrate active microfluidic mixing using the cilia of living Vorticella microorganisms. We apply the nature of particle transport by Vorticella to mix solutions in a stop flow. Two solutions are injected into a microchannel where Vorticella is immobilized. Pneumatic valves are closed to form microchambers for mixing. The ciliary motion of Vorticella induces mixing in the chambers. The mixing process of solutions by Vorticella is characterized. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Determination of nequinate and buquinolate in livestock products using liquid chromatography-tandem mass spectrometry

We studied the simultaneous determination of nequinate and buquinolate, which are used as feed additives to prevent coccidiosis, by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile, then loaded onto an HLB mini-column with 20% methanol. After clean-up with 20% methanol, the analytes were eluted with acetonitrile-methanol (1 : 1). The coccidiostats in the purified samples were determined using ESI-MRM mode LC-MS/MS with a sample matrix calibration curve. Mean recoveries of nequinate and buquinolate from 8 kinds of livestocks samples (chicken muscle, chicken liver, chicken heart, swine muscle, swine heart, cattle muscle, sheep muscle, egg) were in the range of 89.5% to 108.6%, and the relative standard deviation values were <20% (n=10) at the levels of 0.01 μg/g and 0.05 μg/g, respectively. The limits of quantification of these compounds were 0.001 μg/g in each sample.     

The PHO80/TUP7 locus in Saccharomyces cerevisiae is on the left arm of chromosome XV: mapping by chromosome engineering.

The PHO80/TUP7 locus in Saccharomyces cerevisiae is reported to be located on the right arm of chromosome XV close to its centromere. In the present study, the locus has been reassigned to the left arm of the same chromosome by reciprocal recombination between chromosomes V and XV at URA3 (on chromosome V) and PHO80/TUP7 loci by using the site-specific recombination system of the yeast plasmid pSR1.