Silica-supported cobalt catalysts for the selective reduction of nitrogen monoxide with propene

Catalytic behavior of silica-supported transition metals for NO reduction with propene in the presence of oxygen was investigated. While both silica and cobalt oxides did not show any activity for the selective NO reduction, impregnated CoO/SiO₂ prepared from cobalt acetate showed good activity although the preparation conditions had significant effect on the activity. It was suggested that highly dispersed surface Co²⁺ ions on silica are responsible for the catalytic activity.     

Recognition of substrates by membrane potential of immobilized glucose oxidase membranes

The shifts in membrane potential, caused by the injection of glucose into a permeation cell, were measured using immobilized (entrapped) glucose oxidase membranes. No, pH change in the permeation cell was observed upon injection of glucose, but the shift in membrane potential was definitely detected. The shift in membrane potential was observed under nitrogen bubbling (in the absence of oxygen) using initially used enzyme membranes. It was, therefore, suggested that the shifts in membrane potential were not caused by an enzyme-substrate reaction, but by binding of the substrate to the enzyme, which indues a conformational change in the enzyme and leads to a change in charge density in the enzyme membrane. This mechanism is also supported by the fact that the shifts in membrane potential were observed upon injection of not only D-glucose but also L-glucose as reported in our previous study [J. Chem. Soc. Faraday Trans., 87 , 695 (1991)]. © 1994 John Wiley & Sons, Inc.     

Synthesis of Super-Microporous Aluminosilicate Having Excellent Water Vapor Adsorption Property as an Adsorbent for an Adsorption Heat-Pump

The synthesis of super-microporous aluminosilicate with a pore diameter of 14.6 Å has been achieved, by means of synthesis under specified conditions with a skeletal material comprising TMOS and a small quantity of sodium aluminate, and a conventional alkyl-trimethylammonium halide (C₁₀TMABr) as a template. This super-microporous aluminosilicate has an adsorption capacity of 0.2 ml/g at a relative water vapor pressure of 0.2, and thus is promising as an adsorbent for an adsorption heat-pump.     

Shear-rate dependence of first normal stress difference of poly(isoprene-b-styrene) in solution near the order-disorder transition temperature

Viscoelastic properties of poly(isoprene-b-styrene) in dioctylphthalate under steady shear flow were measured near the order—disorder transition temperature. In ordered states, first normal stress difference N₁ is proportional to shear rate at low region, but becomes proportional to at the high region, similar to the N₁ behaviour of polymer blends undergoing shear-induced homogenization. Because the existence of microdomains was confirmed at the high region by the flow birefringence method, it is concluded that the above N₁ behaviour is not caused by shear-induced homogenization, but is probably caused by the shear-induced alignment of the microdomain structure.     

Anodic characteristics of amorphous ternary palladium-phosphorus alloys containing ruthenium,rhodium, iridium,or platinum in a hot concentrated sodium chloride solution

Amorphous ternary palladium-based alloys containing platinum group metals as an additional element were prepared by rapid quenching from the molten state and their anodic characteristics were investigated in a 4 mol dm^?3 NaCl solution of pH 4 and 80° C. The amorphous alloys containing sufficient quantities of rhodium, platinum or iridium were passivated by anodic polarization and their corrosion rates at high current densities in the chlorine evolution region were extremely low. This fact was attributed to the formation of a highly protective passive film due to both the transformation to the amorphous structure and the addition of rhodium, platinum or indium. The electrocatalytic activities for chlorine evolution of amorphous alloys were higher than those of pure platinum group metals except palladium. In particular, the amorphous Pd₄₁Ir₄₀P₁₉ alloy had the desired stable, high electrocatalytic activity for chlorine evolution and the high overvoltage for oxygen evolution.     

低气压等离子喷涂TiO2涂层结构的研究

本研究分析了在低气压等离子喷涂条件下,TiO_2涂层的结构受等离子弧喷涂过程中氧分解量所影响。氧分解量很大程度上依赖于离子气中氢流量的大小,此外喷涂室压力也有一定影响。而等离子弧功率和喷涂距离对TiO_2涂层的氧分解量没有多大影响。在离子气中氢流量不变的条件下,涂层中Ti_3O_5量随喷涂室压力(从100×133.322Pa至400×133.322Pa)增加而增加。     

Swarm robotic network using Lévy flight in target detection problem

One approach in swarm robotics is homogeneous system which is embedded with sensing, computing, mobile and communication components. In this study, a target detection problem, which is one of navigation problems, was employed. Once a robot detects a target, robots immediately communicate with a base station via intermediate relay robots due to the multi-hop transmission of wireless communication. Therefore, this control task is completed with connectivity of the network. In a target detection problem, we must improve the performance of exploration as well as connectivity of the network. This study investigates the performances of the two types of random walk algorithm in navigation while loosely ensuring connectivity of the robotic network based on our previous study.     

Control of secondary flow in concentrically traveling flow on centrifugal microfluidics

This paper reports a fundamental study of the stripe laminar flow pattern on a centrifugal microfluidic device with the goal of realizing a sedimentation-based, continuous mode particle separation technique. Microfluidic channels were designed with a concentrically integrated microchannel, and the patterning of the flow in the channel was investigated. A significant secondary flow was observed as a preliminary result. We conclude that the origin of this secondary flow was not the Dean force, because it was observed in a straight microchannel, but was not observed in curved channel during the spinning of the system at rest. The transition of the pattern was investigated using a simulation and experiment, and the flow pattern’s dependence on the rotational speed was determined, which suggested that the origin of the secondary flow was the Coriolis force. The significance of the secondary flow was controlled by adjusting the rotational speed of the disk, and the flow rate and laminar flow patterns were controlled by the stripe flow pattern.     

A content search system considering the activity and context of a mobile user

People routinely carry mobile devices in their daily lives and obtain a variety of information from the Internet in many different situations. In searching for information (content) with a mobile device, a user’s activity (e.g., moving or stationary) and context (e.g., commuting in the morning or going downtown in the evening) often change, and such changes can affect the user’s degree of concentration on his or her mobile device’s display and information needs. Therefore, a search system should provide the user with an amount of information suitable for the current activity and a type of information suitable for the current context. In this study, we present the design and implementation of a content search system that considers a mobile user’s activity and context, with the goal of reducing the user’s operation load for content search. The proposed system switches between two kinds of content search systems according to the user’s activity: the location-based content search system is activated when the user is stationary (e.g., standing and sitting), while a menu-based content search system is activated when the user is moving (e.g., walking). Both systems present information according to user context. The location-based system presents detailed information via menus and a map according to location-based categories. The menu-based system presents only a few options to enable users to get content easily. Through user experiments, we confirmed that participants could get desired information more easily with this system than with a commercial search system.     

Polytetrafluoroethylene processing characteristics using high-energy X-ray

Polytetrafluoroethylene (PTFE) microstructures’ processing characteristics using X-ray photo dcomposition and desorption are studied in the highest energy region (2 keV to >12 keV). While the exposed surface states are seen melting and boiling from the remaining bubble structure of the irradiated surface, basic photochemistry of PTFE is also same as previous reports and high-aspect ratio structures are successfully formed. We developed new Ni stencil electroformed stencil masks and successfully fabricated first and practical example of PTFE micro fluidic parts. The characteristics of fabricated micro fluidic parts, a PTFE fluid filter for vertical fluid flow operation which works as passive valve, agreed with the calculated results. This suggests that the accuracy of patterning is adequate to apply this technique to fabricate microfluidic parts and other various microparts.