n+ self-aligned-gate AlGaAs/GaAs heterostructure FET

The n+ self-aligned-gate technology for high-performance AlGaAs/GaAs heterostructure FETs employing rapid lamp annealing have been studied. The large transconductance of 330 mS/mm at 300 K and 530 mS/mm at 83 K was obtained for the 0.7 ?m gate length device, by reducing the source resistance to 0.6 ?mm. The minimum delay time of 18.7 ps was obtained with a power dissipation of 9.1 mW at 300 K. The standard deviation of the delay time was as small as 1.1 ps at a fixed bias of 2.5 V.     

Frequency response of a unidirectional-output optical frequencyconversion device with an asymmetrical-κ DBR laser structure

The frequency response of a unidirectional-output optical frequency conversion device is measured. The device has a saturable absorber region within the active region, which acts as an optical gate for converted light. The 3-dB bandwidth of the device with saturable absorber region is measured up to 800 MHz, and is found to be limited by the frequency response of the saturable absorber region. To operate the device faster, lasing mode intensity modulation by input light is attempted by using the device in a laser diode mode. In this case, the electrodes of the saturable absorber and the gain regions are connected electrically, and the saturable absorber region is also biased far above the threshold condition at the same time with the gain region. The 3-dB bandwidth of the device increases to over 10 GHz, and the 10-Gb/s nonreturn-to-zero (NRZ) eye pattern can be observed when the input TM-polarized light intensity is modulated by a 10-Gb/s NRZ pseudorandom signal     

Spectral linewidth reduction (580 kHz) in structure-optimised 1.5 mu m butt-jointed distributed Bragg reflector lasers

Spectral linewidth reduction due to structural optimisation is studied in butt-jointed DBR lasers. It is theoretically shown that a laser structure with passive DBR regions on both sides of an active region is effective in reducing the linewidth.. Based on theoretical calculation, 1.5 mu m butt-joined DBR lasers are fabricated entirely by MOVPE growth. Linewidth is reduced to 580 kHz in structure-optimised 1.5 mu m butt-jointed DBR lasers.<>     

Increase in total blood leukocyte count following intranasal administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in rabbits with cyclophosphamide-induced leukopenia

We investigated the effects of intranasal (i.n.) administration of recombinant human granulocyte colony-stimulating factors (rhG-CSF) on the total count of leukocytes in peripheral blood (total blood leukocyte count) of rabbits with leukopenia who received cyclophosphamide (CPA). When CPA (30 mg/kg per d) was administered intravenously, the total blood leukocyte count decreased to levels below 5000/microliters approximately 4 d after the initiation of CPA multiple dosing. The decreased level of the total blood leukocyte count was maintained throughout the period of CPA dosing. RhG-CSF was given once a day for 3 d in CPA-treated rabbits via i.n. administration of aqueous preparations containing rhG-CSF with or without alpha-cyclodextrin (alpha-CyD). The total blood leukocyte count increased from levels below 5000/microliters to the normal physiological level following i.n. administration of rhG-CSF preparation and reduced the period of leukopenia induced by CPA. The coadministration of rhG-CSF and alpha-CyD was more effective in increasing the total blood leukocyte count. It is suggested that i.n. administration of rhG-CSF is promising for reducing the risk of cytotoxic chemotherapy (CPA)-induced leukopenia as an adverse side effect.     

High-speed intensity modulation of 1.5 μm DBR lasers withwavelength tuning

Intensity modulation characteristics of a 1.5-μm butt-jointed DBR (distributed-Bragg-reflector) laser with wavelength tuning were studied. A 3-dB modulation bandwidth of 9 GHz and a high relaxation oscillation frequency of more than 10 GHz were obtained for the DBR laser. These characteristics were not affected by changing the lasing wavelength. The chirping width of the DBR laser is lower than that of the distributed feedback (DFB) laser. A clear eye opening and low chirping characteristics were obtained under 5-Gb/s nonreturn to zero (NRZ) pseudorandom modulation with a sufficient extinction ratio     

Postmortem changes in bovine troponin T isoforms on two-dimensional electrophoretic gel analyzed using mass spectrometry and western blotting: The limited fragmentation into basic polypeptides

To comprehend postmortem changes in troponin T (TnT), whole beef proteins were developed on a two-dimensional electrophoretic gel. Multiple TnT-related spots were identified by both western blotting and MALDI-TOF MS utilizing bovine TnT isoform mRNA sequences. More than 10 TnT fast-type isoform spots (pI 5.7-9.6<) and the two slow-type isoform spots (pI 5.6-5.7) were observed at slaughter. All the isoforms were degraded exclusively into basic spots (pI 9.6<) at day 14 postmortem. Some TnT-related phosphorylated spots present at slaughter had disappeared by day 14, suggesting that the phosphorylated N-terminal region was cut off during beef aging. The intact isoforms and the fragments were identified by the MS with sequence coverage of 20.8-62.7%, and two of the fragments included the cutting site peptide of a conventional 30kDa or of a slow TnT-derived fragment. These results revealed that all of the TnT isoforms are cut exclusively in the glutamic acid-rich amino-terminal region during postmortem aging.     

Beef texture characterization using internationally established texture vocabularies in ISO5492:1992: Differences among four different end-point temperatures in three muscles of Holstein steers

‘Tenderness’ has been an important sensory characteristic for beef, although ‘tenderness’ has not been commonly defined. On the other hand, ISO5492:1992 provides internationally established vocabularies for sensory analysis with simple definition. The aim of this study was texture characterization for three beef muscles cooked to four end-point temperatures using ISO5492:1992 texture terms in Japanese to develop objective sensory evaluation terms for beef texture other than ‘tenderness.’ Longissimus, semitendinosus, and psoas major muscles harvested from three Holstein steers were cooked to 45, 60, 72, and 92 °C end-point temperatures and evaluated by a trained sensory panel. Correspondence analysis indicated that the ‘chewiness’ and ‘hardness’ defined in ISO5492 were distinguished in each muscle. Changes in the ‘chewiness’ and ‘hardness’ qualities during cooking were different from each other. These findings suggest that both ‘chewiness’ and ‘hardness’ as defined in ISO5492:1992 should be evaluated simultaneously to determine the sensory texture of beef.     

Incorporating Penalty Function to Reduce Spill in Stochastic Dynamic Programming Based Reservoir Operation of Hydropower Plants

This paper proposes a framework that includes a penalty function incorporated stochastic dynamic programming (SDP) model in order to derive the operation policy of the reservoir of a hydropower plant, with an aim to reduce the amount of spill during operation of the reservoir. SDP models with various inflow process assumptions (independent and Markov‐I) are developed and executed in order to derive the reservoir operation policies for the case study of a storage type hydropower plant located in Japan. The policy thus determined consists of target storage levels (end‐of‐period storage levels) for each combination of the beginning‐of‐period storage levels and the inflow states of the current period. A penalty function is incorporated in the classical SDP model with objective function that maximizes annual energy generation through operation of the reservoir. Due to the inclusion of the penalty function, operation policy of the reservoir changes in a way that ensures reduced spill. Simulations are carried out to identify reservoir storage guide curves based on the derived operation policies. Reservoir storage guide curves for different values of the coefficient of penalty function α are plotted for a study horizon of 64 years, and the corresponding average annual spill values are compared. It is observed that, with increasing values of α, the average annual spill decreases; however, the simulated average annual energy value is marginally reduced. The average annual energy generation can be checked vis‐à‐vis the average annual spill reduction, and the optimal value of α can be identified based on the cost functions associated with energy and spill. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Tensile Strength and Deformation of a Two-Dimensional Carbon–Carbon Composite at Elevated Temperatures

Tensile strength and creep behavior of a two-dimensional (2D) laminate carbon–carbon composite (C/C) were examined from room temperature to 2773 K in an inert atmosphere. The tensile strength of the C/C was monotonically enhanced with increasing test temperatures. In particular, significant improvement was observed at temperatures higher than 1773 K. In this temperature range, nonlinear stress–strain curves were observed at low deformation rates, but with increasing test speed, the stress–strain curves became linear until total fracture. The source of the apparent nonlinearity was thus concluded to be creep deformation, which appeared from 1773 K. Two ruling mechanisms for the strength enhancement of the C/C at elevated temperatures were identified. The first source was degassing of absorbed water, which had a dominant influence on the strength enhancement up to 1773 K. The second was creep deformation. This phenomenon was notable at temperatures higher than 1773 K, and produced much larger enhancement than the degassing.     

Determination of gamma-glutamylglutathione and other low-molecular-mass biological thiol compounds by isocratic high-performance liquid chromatography with fluorimetric detection

A method was developed for the simultaneous determination of gamma-glutamylglutathione (gamma-GluGSH) and other low-molecular-mass thiol compounds (cysteine, cysteamine, homocysteine, cysteinylglycine, gamma-glutamylcysteine, glutathione and N-acetylcysteine) using high-performance liquid chromatography combined with precolumn fluorescence labeling with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate (SBD-F). These SBD-labeled thiol compounds were separated within 35 min on a Cosmosil 5C-18AR column with isocratic elution using 75 mM sodium citrate buffer (pH 2.90)-methanol (98:2) and detected fluorimetrically (ex. 386 nm, em. 516 nm). The calibration graphs using 2-mercaptoethanol as an internal standard showed good linearity in the range from 20 pmol to 10 nmol for all thiol compounds examined. The application of this method for the quantitative determination of thiol compounds in the urine from gamma-glutamyl transpeptidase-deficient mice was also demonstrated. This method is sufficiently simple, rapid and sensitive for the determination of gamma-GluGSH and other low-molecular-mass thiol compounds in biological samples.