11 GHz and 12 GHz multiwatt internal matching for power GaAs f.e.t.s

Multiwatt internal-matching techniques for multichip power GaAs f.e.t.s at 11 GHz and 12 GHz bands have been developed, adopting a lumped-element input circuit and a semidistributed output circuit. The internally matched device for the 11 GHz band exhibits 4 W power output with 3.4 dB associated gain, and the 12 GHz device 3.6 W power output with 3 dB associated gain.     

A Barium-Titanate-Ceramics Capacitive-Type EEG Electrode

A capacitive-type electrode using barium titanate ceramics is described. This electrode is not affected by the polarization potential. Because its surface is chemically inactive and mechanically strong, its noise voltage is minimum from the beginning of its installation. This device is especially suitable for EEG recording.     

Human placenta gangliosides

Gangliosides extracted from human placenta were composed of four major components (G1–G4), which were purified by silica beads column chromatography. The structures of these gangliosides were analyzed by exoglycosidase treatments, 400 MHz proton magnetic resonance spectroscopy and gas chromatography-mass spectrometry and were concluded to be as follows: Gangliosides containing more than 10 sugar residues were observed in addition to the above four major components. But ganglio-series gngliosides were undetectable in the placenta.     

Determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts

A method for the determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8)} via 2-methyl-1,4-napthoquinone (NQ) was developed. Measurement conditions were optimized for the microbiological determination of water-soluble vitamins, such as vitamin B₆, biotin, folic acid, niacin, and pantothenic acid, using microorganisms that have a water-soluble vitamin requirement. A linear relationship between absorbance and water-soluble vitamin concentration was obtained. The proposed method was applied to determine the concentration of vitamin B₆ in various foodstuffs. There was good agreement between vitamin B₆ concentrations determined after 24 h using the WST-8 colorimetric method and those obtained after 48 h using a conventional method. The results suggest that the WST-8 colorimetric assay is a useful method for the rapid determination of water-soluble vitamins in a 96-well microtiter plate.     

Development of self-commutated SVC for power system

A 50-MVA self-commutated Static Var Compernsator (SVC) using the worlds's largest GTO thyristors rated 6 kV-2500 A has been developed for voltage control of electric power systems. The rated dc voltage is 16.8 kV which is four times higher than the highest one manufactured so far. To achieve the high dc voltage, eight GTO thyristors are connected in series. Voltage unbalance between GTOs during switching transient was investigated. A new overcurrent limiting method is proposed, since conventional fuse protection cannot be applied due to such high voltage. Newly developed technologies for this large and high-voltage self-commutated SVC are described. Although simple star-delta connection transformers are used, harmonics generated from SVC are almost equivalent to the 24-pulse converter by shifting the pulse timing appropriately. The PWM control based on 150 Hz is applied and the SVC is designed to continue operation during system faults. The performance of the controller is tested successfully by a simulator, and typical rest results are introduced.     

High-throughput screening strategy used for enhanced production of pigment by Monascus purpureus D39-4

Most of the fermentation experiment designs were limited by the low-throughput of shake flask, especially for the medium optimization. A simple high-throughput screening system was developed for the determination of pigment in Monascus purpureus fermentation samples. This downscaled system was designed to optimize medium composition combined with statistical methods. The total 29 experiments designed by the Box-Behnken were used to study the 4 most important operating variables on pigment production. The analysis revealed that the optimum concentrations of glucose, peptone, NaNO₃, and KH₂PO₄ were 51.42, 4.91, 1.00, and 1.00 g/L, respectively. A production of 69.5 U/mL was achieved in agreement with the prediction (68.9 U/mL) fermented in 24-deep-well microtiterplates. Furthermore, the fermentation medium optimized in the high-throughput system was verified in shake flasks, and the pigment production could be enhanced from 206.5 U/mL in un-optimized medium to 265.8 U/mL, giving nearly 1.30-fold increase in production.     

Development of a low-noise analog front-end ASIC for CdTe detectors

This paper describes the recent development of a low-noise analog front-end ASIC for CdTe detectors. The ASIC is designed on the basis of the Open-IP LSI project led by JAXA and implemented using TSMC 0.35-μm CMOS technology. The ASIC contains eight identical channels, each of which includes a charge-sensitive amplifier, band-pass filters, and a sample-and-hold circuit. Preliminary testing of the ASIC achieved noise performance of 188e^-+7.5e^-/pF. In order to verify the low-noise characteristics, the ASIC was connected to a guard-ring-equipped CdTe diode detector with dimensions of and having a thickness of 0.5 mm. As a result, the gamma-ray spectra of radioactive sources were obtained with good energy resolutions of 2.51 and 2.35 keV (FWHM) for gamma rays of 59.5 and 122 keV, respectively, at room temperature.     

波导全息存储器的多层读出特性

研究了多层波导全息存储器的读出特性和读出层的选择方法。通过读出光的位置重合,可读出各个记录层所记录的信息,而不受其他层的影响。而且,通过分析波导射出端的强度图形,可判断读出光和光波导的耦合状态。还研究了利用射出光强度的耦合状态判定法。     

Multi-echelon inventory production system solution

The multi-echelon inventory problem can be examined from the points of view of dynamic programming. The difficulty is that the number of possible states will be exceptionally large. The authors avoid this difficulty by using some formulation. An introductory section surveys what Clark and Clark-Scarf formulated, the problem of a single product carried at an arbitrary number of activities arranged in a series structure. Subsequent sections provide the researches on analytic consideration and numerical consideration. The final section discusses the production planning in a multi-echelon inventory production system.