Transfer hydrogenation and transfer hydrogenolysis. X. Selective hydrogenation of methyl linoleate by indoline and isopropyl alcohol

The selective hydrogenation of methyl linoleate was studied using indoline and isopropyl alcohol as hydrogen sources. Many transition metal compounds and metallic palladium were examined as catalysts. High selectivity to monoenes and little formation oftrans isomers were realized under mild conditions in some reaction systems. For example, the system in which isopropyl alcohol and RuCl₂(PPh₃)₃ were used as hydrogen donor and catalyst was excellent. Also in the hydrogen transfer from indoline to the linoleate catalyzed by PdCl₂ and (NH₄)₂PdCl₄, high selec-tivity was realized. In the RuCl₂(PPh₃)₃-isopropyl alcohol, (NH₄)₂PdCl₄-indoline and PdCl₂-indoline system, methylcis- trans conjugated octadecadienoate was reduced rapidly with complete selectivity, where-as the same hydrogen transfer systems resulted in little if any reaction with methyl oleate. High selec-tivity in the reduction of linoleate is presumed to be realized through prior conjugation of the substrate.     

Selective photooxidation of methane into methanol by nitric oxide over V-MCM-41 mesoporous molecular sieves

The partial photooxidation of methane by nitric oxide selectively led to methanol formation over the V-MCM-41 catalysts under UV irradiation ( > 270 nm) at room temperature, while only a complete oxidation of methane could occur in the presence of oxygen. The yield of methanol corresponds with the yield of the photoluminescence of the isolated tetrahedrally coordinated V-oxides species, indicating that the charge transfer excited triplet state of these species are active sites in this photooxidation reaction.     

Control of real-world complex robots using a biologically inspired algorithm

Elementary living beings, like bacteria, are able to reach food sources using only limited and very noisy sensory information. In this paper, we describe a very simple algorithm inspired from bacteria chemotaxis. We present a Markov chain model for studying the effect of noise on the behavior of an agent that moves according to this algorithm, and we show that, counterintuitively, the application of noise can increase the expected average performance over a fixed available time. After this theoretical analysis, experiments on real-world application of this algorithm are introduced. In particular, we show that the algorithm is able to control a complex robot arm, actuated by 17 McKibben pneumatic artificial muscles, without the need of any model of the robot or of its environment.     

Drastic enhancement of effective thermal conductivity of a metal hydride packed bed by direct synthesis of single-walled carbon nanotubes

Low heat conductivity restricts the rate of hydrogen absorption into a metal hydride, and this leads to a mismatch of the required absorption rate. The use of fin systems is standard in such cases, and the use of several different materials has been attempted. This includes high thermal conductivity carbon brushes and carbon nanotube. Unfortunately, such efforts have not been effective because the boundary thermal resistance has not been addressed. In this study, we focused on the direct synthesis of a single-walled carbon nanotube (SWCNT), which has high thermal conductivity, on particles in a packed bed, for reducing boundary thermal resistance and estimated effective thermal conductivity. Referring to Raman spectra, we succeeded in growing SWCNT on a metal hydride and effective thermal conductivity was estimated as a function of the filling ratios of the metal hydride and the SWCNT. Consequently, the effective thermal conductivity can satisfy the required value.     

Direct synthesis of highly crystalline single-phase hexagonal tungsten oxide nanorods by spray pyrolysis

The metastable state hexagonal-tungsten oxide (h-WO₃) has been attracting attention over the past decade because of its high reactivity that arises from the hexagonal channels in its crystal structure. Simplification of the process used to synthesize h-WO₃ is an important step to facilitate the industrial applications of this material. In this study, we addressed this challenge by developing a spray pyrolysis process to synthesize highly crystalline h-WO₃. The ratio of the monoclinic to the hexagonal phase was controlled by adjusting the segregation time. Single-phase h-WO₃ nanorods were synthesized using a carrier gas flow rate of 1?L/min, which was equivalent to a segregation time of 18.4?s. The ability of the h-WO₃ nanorods to adsorb nitrogen and carbon dioxide was evaluated to confirm the presence of hexagonal channels in the crystal structure.     

Dynamic properties of a flexible metal-organic framework exhibiting a unique"picture frame"-like crystal morphology

The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional devices.However,the influence of such modifications on the dynamic properties of flexible MOFs is poorly understood Here,we report the synthesis of a series of Cu₂(bdc)₂(bpy)(bdc^2-=1,4-benzenedicarboxylate;bpy=4,4,-bipyridine)crystals having an unusual picture frame-like morphology that results from a restriction in the quantity of bpy pillars added to the reaction mixture during the intercalation of the Cu₂(bdc)₂(MeOH)₂layers.The width of the frames is found to correlate with the quantity of bpy,and importantly,causes the dynamic properties of the resulting Cu₂(bdc)₂(bpy)material to vary between rigid,elastic,and shape memory modes.In all,the results demonstrate the potential for the properties of MOFs to be optimized via subtle manipulations in the crystal morphology rather than changes in the overall material composition.     

Development of voltage sag compensator and UPS using a flywheel induction motor and an engine generator

Flywheel energy storage systems are attracting attention as uninterruptible power supplies (UPS) from the viewpoint of environmental friendliness and high durability performance. Using a low‐speed, heavy flywheel and a low‐cost squirrel‐cage induction motor/generator, two applications are proposed: (1) an 11‐kW voltage sag compensator using a capacitor self‐excited induction generator without semiconductor converters and (2) a UPS composed of the flywheel system and an engine generator. Based on experimental results, an ideal voltage sag compensator and UPS are realized by the low‐technology flywheel system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 74– 81, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20784     

Resistance spot welding of metal/carbon-fibre-reinforced plastics and applying silane coupling treatment

Dissimilar materials joining of SUS304 and carbon-fibre-reinforced plastics consisting of short fibres and thermoplastics was performed. The materials were joined by series resistance spot welding. The electrodes were pressed on the metal plate of the lap joint of metal/carbon-fibre-reinforced plastics. The SUS304 plate was heated by resistance heating, causing the thermoplastic near the interface to melt slightly because of heat conduction. SUS304 could be joined directly to carbon-fibre-reinforced polyamide and modified polypropylene, but not to polyphenylene sulphide. The joining area increased with an increase in the welding current and welding time, so did the tensile shear fracture load. Furthermore, the silane coupling agent treatment of SUS304 was highly effective in increasing the joining strength.