Parallel processing for multiplication modulo by means of phase modulation

We apply optical parallel processing to operations for multiplication modulo, which is one of the key components of a factorization algorithm. With this method, optical phase modulation provides the results of modulo operations. We construct a prototype system based on a Michelson interferometer with a photodetector array. Mirrors are set at both object and reference arms to generate interference fringes. A mirror in the object arm is tilted slightly, whereas the reference arm is set perpendicular to the optical axis. The tilt angle is determined by parameters for the target modulo operations. The presented system can achieve massive data processing in parallel with only simple implementation. We present our experimental results to verify the usefulness of our method.     

Fuel ethanol production from sweet sorghum using repeated-batch fermentation

Ethanol was efficiently produced from three varieties of sweet sorghum using repeated-batch fermentation without pasteurization or acidification. Saccharomyces cerevisiae cells could be recycled in 16 cycles of the fermentation process with good ethanol yields. This technique would make it possible to use a broader range of sweet sorghum varieties for ethanol production.     

Image reconstruction for thin observation module by bound optics by using the iterative backprojection method

A method for reconstructing high-spatial-resolution images in an imaging system known as thin observation module by bound optics (TOMBO) is reported. We investigate a novel procedure combining a pixel-rearrangement method and iterative backprojection (IBP). Pixel rearrangement has been used until now in TOMBO, and IBP is a digital superresolution technique. We verify the effectiveness of the combined procedure with simulated and experimental results.     

DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN SEDIMENTS AND BENTHOS COLLECTED ON THE COAST OF CHIBA

Eight polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene were analyzed in sediment and benthos collected on the coast of Chiba Prefecture in Japan by gas chromatography-mass spectrometry (GC/MS). The total concentration of the PAHs ranged from 8 to 18 μ g/kg-dry in the sediments and from 36 to 59 μ g/kg-wet in the benthos, Mactra quadrangularis, Scoletoma nipponica, and Arenicola basiliensis. The PAH composition in the sediments and the benthos was similar at four sampling points and dominated by phenanthrene (Phe), fluoranthene (Flu), and pyrene (Pyr). The ratios of abundance of Flu to that of Pyr, Flu/Pyr, and of Phe/anthracene suggest that the PAHs in the benthos are derived from the combustion of fossil fuels. The ratio, R, of the PAH concentration in the benthos to that in the sediment is 2.0 for Scoletoma nipponica and 1.8 for Arenicola basiliensis in average, indicating that the bioaccumulation is not significant in the benthos. However, the R value for perylene in Scoletoma nipponica was 3.7 times as large as the average.     

Enantioselective hydrogenation of (E)-α-phenylcinnamic acid with cinchonidine-modified Pd/TiO2: influence of solvents and additives

Both the enantioselectivity and activity of the hydrogenation of (E)-α-phenylcinnamic acid with cinchonidine-modified Pd catalysts are strongly solvent dependent; polar solvents with higher solubility for the substrate are preferable. The simultaneous increases in the enantioselectivity and activity, also induced by the addition of either a small amount of water to aprotic solvents or an amine such as benzylamine, indicate that preferential acceleration of the selective reaction has occurred, thus strongly suggesting the importance of the product desorption step on the modified sites. This revised version was published online in June 2006 with corrections to the Cover Date.     

Glass Formation in the System SiO2–PbO Containing Transition-Metal Oxides

Glass-forming regions, valence states, and viscosities in SiO₂–PbO systems containing various transition-metal oxides as a third component were investigated. The glasses were prepared by melting in an open atmosphere. The glass-forming regions ranged as follows: MnO≡ZnO > FeO_1.5>NiO. The ratios Fe²⁺/(Fe²⁺+ Fe³⁺) and Mn³⁺/ (Mn³⁺+ Mn²⁺) in the glasses were determined by chemical analysis. The Fe²⁺/ (Fe²⁺+ Fe³⁺) ratio in SiO₂–PbO–FeO_1.5 glasses ranged from 0.016 to 0.050. The Mn³⁺/ (Mn³⁺+ Mn²⁺) ratio in SiO₂–PbO–MnO glasses ranged from 0.056 to 0.30. The fraction of manganese (III) ions in the glasses varies considerably with the glass composition. The effects of transitionmetal oxides on the viscosity are discussed.     

Local atomic characterization of LiCo1/3Ni1/3Mn1/3O2 cathode material

Co, Ni and Mn K-edge XAFS investigation of LiCo_1/3Ni_1/3Mn_1/3O₂ as alternative cathode material to commercially used LiCoO₂ in lithium rechargeable battery has been performed. Parameters of a local atomic structure such as radii of metal-oxygen and metal-metal coordination shells and disorder in those shells have been determined. It has been found that the radius of the first coordination shell (metal-oxygen) as well as a local disorder in the second shell (metal-metal) around each of the 3d-metals are in a good agreement with obtained for superlattice model of [√3 × √3] R30° type in triangular lattice of sites by first principle calculation. Other parameters of the local atomic structure around Co, Ni and Mn atoms do not provide evidence for presence of superstructure in LiCo_1/3Ni_1/3Mn_1/3O₂.     

Increase of inductance ratio of flat type fault current limiter with high‐Tc superconducting disk

Fault current limiters (FCLs) are expected to reduce fault current and improve stability of power systems. A flat type fault current limiter consisting of the pancake primary winding and a high‐T_c superconducting (HTS) disk was proposed as a modified version of a conventional magnetic shield type of the FCL with the superconducting cylinder. The flat type FCL has the advantage of being manufactured smaller than the cylinder type FCL. It is pointed out, from a magnetic field analysis, that the volume of the flat type FCL is smaller than that of the cylinder type FCL with same magnitude of the limiting inductance. Further, the magnetic field analysis suggests that a high inductance ratio can be realized by radially enlarging both the primary winding and the HTS disk, stacking the FCL modules in layers and sandwiching the primary winding with superconducting disks. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.