Feeding response of the silkworm,Bombyx mori,to UV irradiation of mulberry leaves

Ultraviolet irradiation of mulberry leaves caused a reduced feeding response inBombyx mori larvae (ca. 22% reduction in consumption as compared with control). Sucrose content of the foliage decreased after exposure to UV irradiation (0.5 mW/cm² for 1 hr. Electrophysiological responses of the sensilla styloconica-I to sucrose concentration (ca. 0–80 mg/g) showed a reduced response to UV-irradiated foliage when compared with the control. From feeding, gustatory, and electrophysiological responses, as well as the measurement of sucrose contents of the leaves, we concluded that the reduced feeding response to UV-irradiated leaves is due to the reduced sucrose content of the mulberry leaves, thus reducing pleogostimulatory levels.     

Structure Optimization of the Toxic Conformation Model of Amyloid β42 by Intramolecular Disulfide Bond Formation

Amyloid β (Aβ) oligomers play a critical role in the pathology of Alzheimer's disease. Recently, we reported that a conformation-restricted Aβ42 with an intramolecular disulfide bond through cysteine residues at positions 17/28 formed stable oligomers with potent cytotoxicity. To further optimize this compound as a toxic conformer model, we synthesized three analogues with a combination of cysteine and homocysteine at positions 17/28. The analogues with Cys-Cys, Cys-homoCys, or homoCys-Cys, but not the homoCys-homoCys analogue, exhibited potent cytotoxicity against SH-SY5Y and THP-1 cells even at 10 nM. In contrast, the cytotoxicity of conformation-restricted analogues at positions 16/29 or 18/27 was significantly weaker than that of wild-type Aβ42. Furthermore, thioflavin-T assay, non-denaturing gel electrophoresis, and morphological studies suggested that the majority of these conformation-restricted analogues exists in an oligomeric state in cell culture medium, indicating that the toxic conformation of Aβ42, rather than the oligomeric state, is essential to induce cytotoxicity.     

Effects of epoxy resin on mechanical and thermal characteristics of poly(propylene oxide)/poly(butyl acrylate) networks

We report mechanical and thermal characteristics of a network composed of poly(propylene oxide) (PPG) and poly(butyl acrylate) crosslinked with tolylene diisocyanate. It was found that addition of about 4 wt % of an epoxy resin resulted in a higher mechanical toughness and less discoloration. Furthermore, it was found that the epoxy has a self‐restoration function against thermal degradation of the network. The reaction mechanism between the network and the epoxy was investigated with infrared spectroscopy and ¹³C‐NMR and the effect of the epoxy resin on the thermal stability and physical properties is discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1886–1893, 2000     

Evaluation of extruded cathode honeycomb monolith-supported SOFC under rapid start-up operation

The electrochemical properties of a novel honeycomb solid oxide fuel cell (SOFC), supported by an extruded cathode monolith and capable of generating high-volumetric power density under intermediate temperature operation, are reported. The SOFC was fabricated via the extrusion of a cathode honeycomb support and channel surface coating with electrolyte/anode bilayers using a wet chemical process. Under humidified H₂ fuel flow, high-volumetric power density above 2 and 3 W cm⁻³ at 0.7 V was exhibited at 700 and 750 °C, respectively. In addition, microstructure observation and electrochemical analyses confirmed that the honeycomb SOFC has structural durability for the rapid start-up operation with a heating rate of 100 °C min⁻¹.     

Combined measurement of PEMFC performance decay and water droplet distribution under low humidity and high CO

Measurements of the performance decay for a proton exchange membrane fuel cell (PEMFC) and the observation of water droplets were simultaneously carried out for 4000 h under degradation conditions of low humidity and high CO concentration. An optical cell was designed for observation of water droplets and measurement of the transition points.     

Experimental study of heating fluid between two concentric cylinders with cavities

In this paper, we are concerned with the heating fluid in the annular space between two concentric cylinders where the inner cylinder with cavities is rotated and the outer cylinder is at rest. The effects of cavities of the inner cylinder on the heating fluid and the cavitation behavior are examined. We measured the flow rate, rotating speed of rotor, friction torque, temperature rise and pressure drop between inlet and outlet of this device. The flow rate of water ranged from 0.42×10^-4 to 4.59×10^-4 ma/s at the inlet. The friction torque and the quantity of heat of the inner cylinder with cavities were larger than the case of no cavities, and they increased as the rotating speed of inner cylinder increased. The efficiency was close to about 1 as the rotating speed of inner cylinder increased. The behavior of cavitation in the cavity on the surface of inner cylinder was discussed.     

Output power leveling of wind turbine generator by pitch angle control using H∞ control

Effective utilization of renewable energies such as wind energy is expected instead of the fossil fuels. Wind energy is not constant and windmill output is proportional to the cube of wind speed, which causes fluctuating power of wind turbine generator (WTG). In order to reduce the fluctuating power of WTG, this paper presents an output power leveling technique of WTG by pitch angle control using H_∞ control, and the control input of WTG linear model is separated from the disturbance. The simulation results using actual detailed model for WTG show the effectiveness of the proposed method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 17–24, 2008; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20657     

Realization of acceleration control using multirate sampling method

This paper focuses on the realization of high‐performance motion control based on acceleration control. The characteristics of acceleration control are investigated and the relationship between the performance and sampling frequency of the system is discussed. This paper then describes that a higher sampling frequency is required for acquisition of output information than for updating the input value. Based on this idea, a new multirate sampling method for an acceleration control system is proposed. A disturbance observer for the multirate system is designed by adopting a new definition of disturbance torque. A bilateral system is introduced as a preeminent example of a system that requires robust acceleration control. Both simulations and experiments are performed on the system, and the validity of the proposition is verified by the results. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 72–81, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20507     

How accurately people can discriminate the differences of floor materials with various elasticities.

Tactile ground surface indicators installed on sidewalks help visually impaired people walk safely. However, these indicators sometimes cause the nonvisually impaired to stumble. Thus, these indicators also have to be made safer and less of a problem for those who do not use them. There are several facilities in Japan that have installed floor materials of different elasticity to indicate paths for the visually impaired. However, the effectiveness of this method has not been tested. Therefore, this study examined how accurately people can discriminate differences in the elasticity of flooring samples. Flooring samples of different elasticity were presented by placing two walking boards made of plywood, each surfaced with one of three different flooring samples, in an end-to-end fashion. Ten young adults whose sight was temporarily cutoff by eye masks were asked to walk on the path for 144 trials and indicate whether the flooring samples were different or not. Interestingly, the percentages of correct answers were high for most pairs of samples. Moreover, there was a strong positive correlation between the percentage of correct answers and the magnitude of difference in floor elasticity. These results indicate that people can distinguish changes of flooring samples fairly accurately, even when there are no convexities, if there is sufficient difference in elasticity between the flooring samples.