Interlaboratory study of LC-UV and LC-MS methods for the simultaneous determination of deoxynivalenol and nivalenol in wheat

To evaluate LC methods with UV or MS detection for simultaneous analysis of deoxynivalenol (DON) and nivalenol (NIV) in wheat, an interlaboratory study was conducted in 11 laboratories. DON and NIV were purified using a multifunctional column, and their concentrations were determined using LC-UV or LC-MS(/MS). No internal standards were used. Three fortified wheat samples (0.1, 0.5 and 1 mg/kg), one naturally contaminated wheat sample, and one blank wheat sample were used. The recoveries ranged from 90% to 110% for DON and from 76% to 83% for NIV. For DON, the relative standard deviations for repeatability (RSDr) ranged from 1.1% to 7.6%. The relative standard deviations for reproducibility (RSDr) ranged from 7.2% to 25.2%. For NIV, the RSDr ranged from 2.0% to 10.7%, and the RSDr ranged from 7.0% to 31.4%. Regardless of sample and detector, the HorRat values for DON and NIV ranged from 0.4 to 1.4. Both LC-UV and LC-MS(/MS) methods were considered to be suitable for application as an official method.     

Effects of alginate oligosaccharide mixtures on the growth and fatty acid composition of the green alga Chlamydomonas reinhardtii

Alginate is a natural acidic linear polysaccharide that is produced by brown seaweeds. It is currently used in a broad range of commercial enterprises, such as the food and medical products industries. Recent evidence has demonstrated that alginate oligosaccharides may function as growth promoting agents for certain plant cells, including those of some green algae. Chlamydomonas reinhardtii is a green alga that is used as a model organism in fundamental molecular biology studies; it is also a producer of biohydrogen. In the present study, we examined effects of two types of alginate oligosaccharide mixtures (AOMs), which were prepared by either enzymatic degradation (ED) or acid hydrolysis (AH), on the growth of C. reinhardtii. Growth was significantly promoted by AOM (ED) in a concentration-dependent manner. The maximum effect was observed on day 4 of treatment. The fatty acid composition of C. reinhardtii was also influenced by AOM (ED); the levels of C16:0, C18:2 cis and C18:3 n-3 increased in treated cells. AOM (AH) and the other saccharides that we tested did not affect the growth of C. reinhardtii. The effects that we identified could promote efficient biomass production by reducing culture times and by changing cellular fatty acid levels.     

Lithium hydrazide as a potential compound for hydrogen storage

The Metal–N–H system for hydrogen storage has been developed in recent years and is considered to be a promising solution. Here we report a potential compound for hydrogen storage, LiNHNH₂, which is a white solid with 8.0 mass% theoretical hydrogen content and can be synthesized from anhydrous hydrazine and n-butyllithium in diethyl ether. The thermodynamic behaviours and hydrogen storage properties of this compound were firstly investigated and are discussed in this paper. We demonstrate the decomposition pathway of LiNHNH₂ and reveal that an alkali metal hydride such as LiH can significantly increase the hydrogen desorption from LiNHNH₂. Moreover, LiNHNH₂ can also be used for destabilizing other hydrogen storage systems owing to its instability.     

Evolution of ultrafine microstructures in commercial purity aluminum heavily deformed by torsion

Commercial purity aluminum (1100Al) bars were severely plastic deformed by torsion deformation at room temperature. The specimens were deformed to ultrahigh equivalent strain of 5.85 in maximum. Microstructure evolution during the torsion deformation was characterized using electron back scatter diffraction analysis on two different sections: the longitudinal section parallel to the torsion axis and transverse section perpendicular to the torsion axis. The grain size decreased and the fraction of high angle grain boundary increased with increasing equivalent strain. Elongated ultrafine grained structure was obtained after an equivalent strain of 3.27. We have found that the microstructure evolution in the specimen deformed by torsion exhibited similar behavior to those in the same material heavily deformed by accumulative roll bonding. The average grain size of 0.32 μm with the high angle boundary fraction of 0.76 was achieved in the specimen deformed to an equivalent strain of 5.27. Though the microstructure and hardness on the transverse section varied depending on the radial positions, they could be arranged as a simple function of equivalent strain. The present work confirmed that the torsion deformation worked as a kind of severe plastic deformation.     

Synthesis and electrochemical properties of nanosized LiFeO2 particles with a layered rocksalt structure for lithium batteries

Layered rocksalt-type LiFeO₂ particles (O3-LiFeO₂) with average particle sizes of ca. 40 and 400 nm were synthesized by an ion exchange reaction from α-NaFeO₂ precursors. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images confirmed the formation of nanosized O3-LiFeO₂. 40-nm LiFeO₂ exhibited a higher discharge capacity (115 mAh g^?1) than 400-nm LiFeO₂ (80 mAh g^?1), and also had better rate characteristics. The downsizing effect and cation disorder between the lithium and iron layers may have improved the electrochemical activity of the LiFeO₂ particles. Transmission electron microscopy (TEM) observation indicated a phase transition from O3-LiFeO₂ to a cubic lattice system during the electrochemical process. The cubic lithium iron oxide exhibited stable electrochemical reactions based on the Fe²⁺/Fe³⁺ and Fe²⁺/Fe⁰ redox couples at voltages between 4.5 and 1.0 V. The discharge capacities of 40-nm LiFeO₂ were ca. 115, 210, and 390 mAh g^?1 under cutoff voltages of 4.5–2.0 V, 4.5–1.5 V, and 4.5–1.0 V, respectively.     

Soft-lithographic methods for the fabrication of dielectrophoretic devices using molds by proton beam writing

Proton beam writing (PBW) was applied to the fabrication of dielectrophoretic (DEP) devices equipped with high-aspect-ratio pillar arrays. With coupled use of soft lithography for micro-fluidic channels, we successfully fabricated a device equipped with SU-8 pillar arrays produced by PBW, which is covered with a poly-dimethylsiloxane (PDMS) micro-fluidic channel. For more simplified prototyping of the device, we modified a SU-8 mold for simultaneous replication of both pillar arrays and micro-fluidic channel on PDMS. Replication of pillar arrays is limited to the aspect ratio of less than three.     

High power ytterbium fiber lasers at extremely long wavelengths by photonic bandgap fiber technology

Yb-doped fiber laser operating at the long-wavelength edge (1150–1200 nm) of the broad gain spectrum has been investigated for yellow-orange sources. Power scaling in this region has been recently achieved by Yb-doped solid-core photonic bandgap fibers, in which the Yb gain profile is engineered by the sharp-cut, bandpass distributed filtering and therefore amplified spontaneous emission in the high-gain region (1030–1100 nm) is strictly inhibited. We have recently demonstrated amplification with as high as 167 W output power and 61% slope efficiency at 1178 nm. The novel gain profiling technique by photonic bandgap fibers can be extended to other rare-earth doped fibers.     

Technical requirements for UHV substation equipment

CIGRE Study Committee A3 established WG A3.22 ‘Technical requirements for substation equipment exceeding 800 kV’ to review the state-of-the-art technical specifications for substation equipment exceeding 800kV in accordance with a request from IEC SC 17A. WG A3.22 conducted the initial surveys and submitted the first Technical Brochure on technical specifications for substation equipment such as gas circuit breaker (GCB), disconnecting switches (DS), earthing switches (ES), high-speed grounding switches (HSGS) and metal oxide surge arrester (MOSA) applied to 800 kV and 1100/1200 kV networks. The investigations include the insulation level, first-pole-to-clear factor, DC time constants, transient recovery voltage (TRV), line surge impedance and secondary arc extinction time. WG A3.22 will provide the technical background of all aspects of the available specifications with the intention of identifying the best practice for ultra high voltage (UHV) transmission systems. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.