Hyper-Kloosterman Sums and their Applications to the Coding Theory

The dual code of the Melas code is called the Kloosterman code. The weights of its codewords can be expressed by the Kloosterman sums, and are uniformly distributed with respect to the Sato-Tate measure. In this paper, the hyper-Kloosterman code C _m (q), a generalization of the Kloosterman code is defined, and the uniform distribution property is deduced using the hyper-Kloosterman sums when m is even and p− 1|m. Finally we discuss doubly-evenness for the weights in the binary case. It shows that we can construct infinitely many doubly-even codes in a non-trivial way. Received: October 30, 2000; revised version: February 28, 2001     

Rapid sensing of trace ionic substances with the novel porous monolith type ion exchanger

Biological and chemical sensor with a rapid response in microlevel test is required for health and environmental monitor. A novel sensing due to porous ion exchanger with three-dimensional acceptor has been first attempted to develop a high-performance sensor. This porous monolith type ion exchanger has an open-cellular monolith structure with 5–50-μm diameter pores. The trace amount of inorganic ions dissolved in aqueous solutions can be quantitatively determined with the impedance given by the monolith, which attracts and adsorbs the ions rapidly. We have succeeded in detecting ions with a concentration as low as 10⁻⁷ mol. The porous ion exchanger has a potentiality as a high-performance device for biological and chemical sensing. POLYM. ENG. SCI., 47:1666–1670, 2007. © 2007 Society of Plastics Engineers     

Fiber-optic transceiver with an optical circulator for opticaltime-domain reflectometers

The paper describes the characterization of an improved fiber-optic transceiver for optical time-domain reflectometers (OTDR). The transceiver employs an active fiber ring which has both transmitter and receiver functions of OTDR. An optical circulator takes the place of the combination of a 3-dB coupler and an optical isolator in the previously reported system. Reflections from several lengths of cascaded fibers are measured to characterize the transceiver. Compared with the previous system, performance improvement of the transceiver with the optical circulator is achieved     

20 Gbit/s chirped return-to-zero transmitter with simplifiedconfiguration using electroabsorption modulator

A novel chirped return-to-zero transmitter with a simplified configuration that uses an electro-absorption modulator is proposed. Using this transmitter, high fibre input power is achieved (up to +14 dbm) in repeaterless 20 Gbit/s transmission over standard singlemode fibres     

A poly-silicon TFT with a sub-5-nm thick channel for low-power gain cell memory in mobile applications

This work presents a gain-cell solution in which a novel ultrathin polysilicon film transistor provides the basis for dense and low-power embedded random-access memory (RAM). This is made possible by the new transistor's 2-nm-thick channel, which realizes a quantum-confinement effect that produces a low leakage current value of only 10/sup -19/ A at room temperature. The memory has the potential to solve the power and stability problems that static RAM (SRAM) is going to face in the very near future.     

Organocatalytic Enantioselective Conjugate Addition of Malonic Acid Half Thioesters to Coumarin‐3‐carboxylic Acids Using N‐Heteroarenesulfonyl Cinchona Alkaloid Amides

We disclose herein an efficient enantioselective conjugate addition reaction between coumarin‐3‐carboxylic acids and malonic acid half thioesters (MAHTs). The reaction was catalyzed by N‐heteroarenesulfonyl Cinchona alkaloid amides to afford double‐decarboxylative conjugate addition products in good yield with high enantioselectivity. The reaction of various coumarin‐3‐carboxylic acids with MAHTs gave products in high yield with high enantioselectivity.

     

Experimental analysis for extrusion screw geometry to produce highly transparent polypropylene sheets

The observation was experimentally conducted by using many screws with various geometries to obtain a highly transparent polypropylene melt resin sheet. The pressure distribution in the extruder, melt temperature profile across melt flow, the extruder throughput and the specific energy consumption were monitored. In a preliminary evaluation, transparent melt web was obtained in a simple straight channel depth screw and a straight channel depth screw with a torpedo type barrier section. The transparency of melted resin sheet was obtained by the screw geometry so that the specific energy consumption was small and the melted temperature was low. Based on these results and taking a wide applicability for a large size extruder of the production machine into consideration, the screw of gently tapered compression with a torpedo type barrier section was selected as the basic design of the screw geometry to satisfy both the transparency and the extrusion stability. The screw geometry optimization was conducted using the analysis of melting performance by the cooling experiment and the pressure pattern. As a result, the screw geometry to satisfy a low external haze and an extrusion stability under higher throughput conditions was designed. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Transfer of high-mannose-type oligosaccharides to disaccharides by endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae

Endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) has transglycosylation activity, and high-mannose-type oligosaccharides are transferred to suitable glycosides as acceptor substrates. The acceptor specificity of Endo-A-catalyzed transglycosylation toward various disaccharides was investigated. To identify an effective acceptor for the transglycosylation by Endo-A, the reaction was carried out using various disaccharides. Endo-A transferred high-mannose-type oligosaccharides more efficiently to beta-linked disaccharides (cellobiose, gentiobiose, sophorose, and laminaribiose) than to alpha-linked disaccharides (isomaltose, maltose, nigerose, kojibiose, and trehalose) as acceptor substrates. The transglycosylation products, (Man)6GlcNAc-Glc-beta-Glc, were more rapidly hydrolyzed than (Man)6GlcNAc-Glc-alpha-Glc. These results indicate that Endo-A recognizes the anomeric configuration of the acceptor substrates, and beta-linked glycosides are suitable for the synthesis of transglycosylation products.     

Estimation of source contribution to nitrate loading in road runoff using stable isotope analysis

The nitrogen load was determined in road runoff during rainfall events. Moreover, nitrate isotopes analysis was conducted to determine the contribution of nitrates from atmospheric deposition and leaching from road dust. The concentrations of NO₃-N in road runoff were higher than those in atmospheric deposits for each rainfall event, except one event with a long antecedent dry weather period. The δ¹⁸O-NO₃ in road runoff was lower than in atmospheric deposits and higher than in leachate from road dust; however, no difference in δ¹⁵N-NO₃ was observed. By using δ¹⁸O-NO₃ as an indicator for evaluating NO₃-N sources in road runoff, contribution ratios of NO₃-N from road dust were estimated to be 14–22%, 23–25%, and 22–34% for Event 1 to Event 3, respectively. These results indicated that the NO₃-N from the atmosphere accounts for more than half of the NO₃-N in road runoff.