Factors affecting the oxidative activity of laccase towards biphenyl derivatives in homogeneous aqueous-organic systems

Catalytic oxidation of biphenyl derivatives was investigated using laccase in a homogeneous aqueous-organic system. A thermostable laccase from Trametes sp. showed the highest catalytic activity for the oxidation of 4-hydroxybiphenyl (4-HB) at a reaction temperature of 60 degrees C when dimethylsulfoxide (DMSO) was employed as a co-solvent. Furthermore, the catalytic performance was successfully enhanced by the incorporation of a laccase mediator system (LMS) into the aqueous-DMSO media. The catalytic performance strongly depended on the type of mediator, and the highest activity was observed with 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as mediator, suggesting the importance of the selection of a suitable mediator. It was verified that this mediator system is applicable to the oxidation of several biphenyl derivatives with hydroxyl groups.     

Wind-flow measurement over the Subaru Telescope

Wind flows over the 8.2-m Subaru Telescope at Mauna Kea in Hawaii were analyzed with a correlation method. Three or four wind flows were detected from our measurements. Spatial and temporal resolution of the wind-flow analysis across the 8.2 m pupil were investigated experimentally. A three-dimensional spatiotemporal-frequency analysis was also applied to the wind-flow data.     

Establishment of a simple method for measurement of chronic blood flow in uterine artery of pregnant cows

Blood flow to the gravid uterine horn of seven multiparous Holstein cows (mean +/- SD, BW = 625.5 +/- 82.4 kg; age = 4.7 +/- 1.7 yr; parity = 2.9 +/- 1.1 yr) was measured from d 225 of gestation to parturition using transit-time ultrasonic blood flow probes placed around the middle uterine artery. Surgery was conducted on d 215 of gestation. The cows were sedated with xylazine and local anesthesia (procaine or bupivacain hydrochloride) during surgery. The surgical operations were conducted at the flank of standing cows. A transit time ultrasonic flow probe ("S" series, diameter 12 or 14 mm, Transonic Systems Inc., Ithaca, NY) was fitted surgically around the uterine artery of each cow. Surgery was completed within 2 h of anesthesia, and the animals recovered rapidly following surgery. Uterine blood flow (UBF, L/min) was recorded at 10-s intervals for 1395 min; these values were averaged to determine UBF. Cows exhibited normal gestation lengths (279.1 +/- 7.4 d), gave birth to normal healthy calves (birth weight = 40.6 +/- 6.6 kg), and had no retained placentas. The UBF increased significantly (P < 0.01) from d 225 (6.67 +/- 2.47) to d 249 (8.23 +/- 2.89) of gestation, but the latter UBF was similar to that of d 266 (8.38 +/- 2.70). The increased UBF after d 225 indicates increased demand of nutrients of fetus with the progress of gestation. The range of mean UBF varied widely among individual cows from 4.1 L/min to 12.2 L/min. Our method is useful for chronic measurement of UBF in cows for nutritional or physiological studies and does not require sophisticated facilities or special surgical technique.     

Magnetization Curve of Two-Dimensional Anti-ferromagnetic Solid 3He on Graphite

Two-dimensional anti-ferromagnetic solid ³He on graphite, so called 4/7 phase, is a highly frustrated magnetic system and its ground state is considered to be a gapless spin liquid. Then how is the behavior in high magnetic fields? We tried to observe the magnetization curve at around 1 mK in high magnetic fields up to 10 T, using a Faraday-type magnetometer. To eliminate a large background signal from graphite as a substrate and copper as a thermal link, a double gradient coil system is employed to produce opposite field gradients in two regions equidistant from the field center. Preliminary results of the 4/7 phase on graphite show no saturated magnetization even at 1 mK and 10 T, suggesting the existence of magnetization plateau.     

A New Neutral-Point-Clamped PWM Inverter

A new neutral-point-clamped pulsewidth modulation (PWM) inverter composed of main switching devices which operate as switches for PWM and auxiliary switching devices to clamp the output terminal potential to the neutral point potential has been developed. This inverter output contains less harmonic content as compared with that of a conventional type. Two inverters are compared analytically and experimentally. In addition, a new PWM technique suitable for an ac drive system is applied to this inverter. The neutral-point-clamped PWM inverter adopting the new PWM technique shows an excellent drive system efficiency, including motor efficiency, and is appropriate for a wide-range variable-speed drive system.     

Analytic Flow Design Method for an Automated Distribution Center with Multiple Shipping Areas

An analytic flow design algorithm for an automated distribution center with multiple shipping areas is presented. The main elements of the analytic flow design are the number of devices and the volumes of product flow between the devices. In the design of an automated distribution center, it is necessary to satisfy the demand throughput while minimizing construction costs. In the conventional design process, system engineers utilize experimental and intuitional approaches. However, conventional approaches are time-consuming and the design outcome is dependent on the skill of the designer. Therefore, a theoretical design algorithm is needed. We propose an analytic flow design algorithm using a dynamic network flow model and considering time-variable flow volumes according to shipment and storage schedules. To verify the feasibility of the proposed method, we perform analytic flow design using real data and confirm that the proposed method can yield a feasible analytic flow design in several minutes.     

Organic LED full-color passive-matrix display

Abstract— A full-color 5.2-inch 1/4-VGA passive-matrix organic LED display has been developed, adopting selective deposition for the different emitting materials. The display features 320 (×3) × 240 pixels with an equivalent pixel size of 0.33 × 0.33 mm, white peak luminance of over 150 cd/m², and power consumption of 6 W.     

Novel Structures for Porous Silicon Light-Emitting Diodes

In this paper, two novel structures of porous silicon (PS) light-emitting diodes (LEDs) are proposed aiming at the reduction of series resistance, R_s. The basic idea of the novel structures is to suppress the excessive growth of nanoporous silicon (nano-PS) layer that is electroluminescence- (EL-) active but highly resistive. The initial wafer of the first structure consists of a lightly-doped layer stacked on a highly-doped substrate. As a consequence of anodization, nano-PS layer is formed only in the lightly-doped layer, while meso-PS layer with moderate resistivity is formed in the highly-doped substrate. The second structure consists of alternately stacked nano- and meso-PS layers, since it is expected that multiple thin nano-PS layers connected in series are less resistive than a single thick nano-PS layer. Preliminary experimental results proved the effectiveness of these novel structures on the reduction of R_s.     

High-Performance Control Strategy of Cycloconverter-Fed Induction Motor Drive System Based on Digital Control Theory

The field-oriented control, or the vector control, has emerged as a powerful tool for controlling squirrel-cage induction motors. The dynamic performance, however, depends on the controllability of the stator currents.