Shape recovery and irrecoverable strain control in polyurethane shape-memory polymer

In shape-memory polymers, large strain can be fixed at a low temperature and thereafter recovered at a high temperature. If the shape-memory polymer is held at a high temperature for a long time, the irrecoverable strain can attain a new intermediate shape between the shape under the maximum stress and the primary shape. Irrecoverable strain control can be applied to the fabrication of a shape-memory polymer element with a complex shape in a simple method. In the present study, the influence of the strain-holding conditions on the shape recovery and the irrecoverable strain control in polyurethane shape-memory polymer is investigated by tension test of a film and three-point bending test of a sheet. The higher the shape-holding temperature and the longer the shape-holding time, the higher the irrecoverable strain rate. The equation that expresses the characteristics of the irrecoverable strain control is formulated.     

VARIATION IN THE ANTIANDROGENIC ACTIVITY OF DIESEL EXHAUST PARTICULATES EMITTED UNDER DIFFERENT ENGINE LOADS

We examined endocrine disruptors in diesel exhaust particulates (DEP) emitted from a diesel engine under different engine loads. The antiandrogenic and aryl hydrocarbon receptor (AhR) agonistic activity of DEP extracts (DEPE) were evaluated using PC-3/AR human prostate cancer cells transiently transfected with androgen- or AhR agonist-regulated luciferase reporter plasmids, respectively. The antiandrogenic and AhR agonistic activities were enhanced by higher engine load. The AhR antagonist α-naphthoflavone reversed the antiandrogenic activity of DEPE as seen through a reduction in AhR agonistic activity. The concentrations of polycyclic aromatic hydrocarbons (PAHs) with four or more rings, which are AhR agonists in DEPE, increased with higher engine load. Therefore, the enhanced antiandrogenic activity of DEPE is due in part to the increase in AhR agonists such as PAHs with higher engine load.     

Green leaf volatiles enhance methyl jasmonate response in Arabidopsis

Plants emit green leaf volatiles (GLVs) in response to insect or pathogen damage. GLVs consist of C6 and C9 aldehydes, alcohols, and their acetate esters, and play important roles in the plant defense response. One of the functions of GLVs in the defense response is priming. Plants pretreated by GLVs can induce a defense response more rapidly and effectively than unpretreated plants when they are damaged by pathogens or insects. In this study, we focused on the priming effects of GLVs on jasmonic acid response involved in the defense response. When Arabidopsis was pretreated with aldehyde GLVs, especially with (E)-2-hexenal, the anthocyanin content was significantly increased by a subsequent methyl jasmonate (MeJA) treatment. On the other hand, no effect of anthocyanin accumulation was observed for plants pretreated with alcohol GLVs. These results suggest that aldehyde GLVs, especially (E)-2-hexenal, could enhance sensitivity to MeJA in Arabidopsis.     

A calculation method of the total efficiency of wind generators

The spread of wind energy converters is progressing in recent years and its capacity is becoming larger and larger. In order to capture more energy from the wind, it is important to analyze loss characteristics of wind generators for the operating speed which is determined dependent on the wind speed. This paper presents a method to evaluate various losses in a wind generator as a function of wind speed, which is based on steady‐state analysis and thus the calculations can be performed quickly. By using the proposed method, wind turbine power, generator output, various losses, and the total energy efficiency are calculated for three types of wind speed data which are represented by a Weibull function. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(3): 52–62, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20426 Copyright © 2006 Wiley Periodicals, Inc.     

Development of QTAT online electronic circuit patterning system

An arbitrary pattern exposure system has been developed by employing a liquid crystal display (LCD) with 1600 /spl times/ 1200 pixels for the formation of projection images in place of a conventional reticle. The minimum pattern size becomes 11.5 /spl mu/m, which corresponds to the aperture size of each pixel on the LCD. For the purpose of quick turnaround time (TAT), the exposure system was directly connected to the circuit design system with the transmission control protocol/internet protocol network. From the experimental results on patterning of a typical electronic circuit data with the area of 46/spl times/ 46 mm, it was confirmed that the TAT from the output of design data to the finish of the exposure becomes less than 28 min. By using this system, reduction of the production cost in the printed wiring boards fabrication is expected.     

Cooperative operation of a wind energy conversion system with a hydrogen electrolyzer by using an adjustable speed flywheel generator

Hydrogen is considered as the energy source of the next generation. This paper proposes a system which consists of Flywheel Generator (FWG), Wind Energy Conversion System (WECS), and Hydrogen Electrolyzer (HE), for the purpose of hydrogen generation and grid output power smoothing. The cooperative control among flywheel generator, hydrogen electrolyzer, and wind generator is performed by controlling the flywheel generator. Simulations have been done by PSCAD/EMTDC. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(3): 19–27, 2009; Published online in Wiley InterScience ( www.interscience.wiley. com ). DOI 10.1002/eej.20863     

Thermal switching of the actuation ability of an electroactive polymer actuator

Electroactive polymer actuators have the simple ability to be actuated by a voltage. In this study, we added a new function: the ability to be actuated by temperature. We used a bending‐electrostrictive actuator made of a polyurethane film. The polyurethane was designed to be rigid at room temperature but to be flexible at temperatures greater than 40°C because of the melting of the soft segment in the polyurethane. Therefore, the actuator showed slight bending in response to a voltage at room temperature. However, it showed significant bending at 61°C. The degree of bending at 61°C was 29 times greater than that at 13°C. Thus, the actuation ability was switched on at 61°C but switched off at 13°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1566–1570, 2005     

Effect of macrophage colony-stimulating factor (M-CSF) on mouse immune responses in vivo

We examined the effects of recombinant human M-CSF (rhM-CSF) on mouse macrophages and immune responses in vivo. Intraperitoneal administration of rhM-CSF (20-500 microgram/ml) increased Mac-1+ cell numbers in the peritoneal cavity. The tumoricidal activities of the macrophages from vehicle-administered (V-M phi) and from rhM-CSF-administered (M-M phi) mice were the same as those observed in vitro. However, when activated by lipopolysaccharide (LPS), the tumoricidal activity of M-M phi was stronger than that of V-M phi. Intravenous administration of rhM-CSF (500 micrograms/gk) increased the number of spleen cells. Flow cytometric analysis showed that administration of rhM-CSF increased Mac-1+, B220+ and NK 1.1+ cell counts in the spleen. However, CD4+ and CD8+ cell numbers did not change. Concomitant increases were observed in levels of IL-4 and IL-10 in mouse serum following rhM-CSF administration, but no significant changes were observed in the serum level of IFN-gamma. In experiments involving mouse immune responses, the administration of rhM-CSF reduced the contact sensitivity (CS) reaction against picryl chloride (PC) and augmented IgE production in response to 2,4-dinitrophenyl (DNP), but did not affect the production of either IgM or IgC1. These results suggest that administration of rhM-CSF not only activates murine macrophages, but modulates antigen-specific immune responses in vivo.     

Hybrid Josephson Junctions with Iron-based and Conventional Superconductor Electrodes

We investigate the iron-based superconductor Ba(Fe _1?x Co _x ) ₂As ₂ (Ba-122) regarding its superconducting properties and possible applications. Therefore, Ba-122 thin films are used as base electrode to prepare different kinds of hybrid Josephson junctions with a counter electrode of the conventional superconductor Pb. Additionally, we use both c-axis and a b-plane transport geometries and different kinds of barriers like interface-engineered surfaces, sputtered titanium oxide and gold layers. Temperature dependent I– V characteristics as well as magnetic field dependence and microwave response of the junctions are shown. The examined I– V characteristics and I _c R _n– T behaviours of each junction type are compared and described according to the electrical behaviour of the respective normal conducting or insulating barrier. While the I _c R _n product of the interface-engineered barrier junction was 12 μV and the planar junction with Au barrier showed 18 μV, we could increase the I _c R _n to 90 μV for planar TiO _x barrier junctions.