Functional Neuromuscular Stimulation for articular angle control with an Inverse Dynamics Model tuned by a neural network

A Functional Neuromuscular Stimulation (FNS) system was developed to restore the motor function of people with central nervous system disorders. An FNS articular angle control system with an Inverse Dynamics Model (IDM) tuned by a neural network was proposed. The system was designed to control the elbow joint angles by learning the characteristics of the neuromuscular system of controlled limbs. Three kinds of control schemes using the IDM were proposed. In a simulation experiment, the system was able to learn the abnormal characteristics of a limb and any changes in these characteristics, and then allow for better control of the limb. The results of experiments using human participants showed that the system had ability to control both normal and paralysed limbs.     

Design systems for gear elements made of cotton fiber-reinforced plastics

We look on the cotton fiber reinforced plastics as industrial gear materials, and have been developing design systems for industrial gears made of cotton fiber-reinforced plastics. In this report, we deal with a method estimating for tooth root stresses caused by bending movements under running conditions. The gear material used was cotton fiber plain woven cloth reinforced phenolic resin laminates. Paper-reinforced phenolic resin laminates, a commonly used material, was used as a control for comparison. The main dimensions of the gears were module 3–5 mm and tooth width 25 mm. First, accelerations of gears were measured under running conditions to estimate dynamic performance. Second, fracture tests of gear teeth were carried out under bending loads. Different fracture modes at tooth roots for cotton fiber-reinforced plastics and phenolic resin gears were observed. The fractures occurred at a high position from the tooth root in the case of the cotton fiber-reinforced plastics gear because the cotton fiber-reinforced plastics had excellent cleavage and shear strength. This gear also had higher strength for tooth bending loads. Third, the mechanical properties of the gears were researched by tensile, bending, and shearing tests. It was clear that the cotton fiber-reinforced plastics had excellent properties in cleavage fracture between laminates and shear strength. Finally, we proposed a design method for this gear, which considers the cleavage and shear strength.     

Electron-microscopical observation of crystal growth in amorphous Fe75B25 alloy

Amorphous ribbons of Fe₇₅B₂₅ alloy were made by melt-spinning and their crystallization process was observed in situ under a transmission electron microscope (TEM). Especially, the growth rate of b c t Fe₃B crystals was measured with high precision at various temperatures, and the kinetics of the movement of the amorphous-crystalline interface was examined. Differing from the amorphous Fe₈₆B₁₄ alloy studied earlier and other Fe-B alloys with compositions not close to the 31 stoichiometry, crystal growth in the Fe₇₅B₂₅ alloy showed a perfect linearity against time, with no relaxation phenomena being observed. The linear growth was not disturbed by the small concentration deviations or the crystal orientations. When the annealing temperature was changed stepwise up and down between 190° C to 380° C, the linear growth was maintained at each temperature and no temperature hysteresis of the growth rate appeared. The Arrhenius plots of the growth rates gave an apparent activation energy of about 2 eV, but the plotted lines were not exactly straight but upward concave and/or convex. Theoretical analysis of the reaction kinetics of the amorphous-crystalline boundary movement was based on either the concept of multiple processes connected in series or in parallel or of the temperature-dependent activation energy of the process. Good agreement between the calculated and experimental curves was obtained and underlying mechanisms of the growth process were considered and discussed. It was concluded that the crystal growth process of amorphous Fe₇₅B₂₅ alloy is not controlled by long-range diffusion but presumably by small concentration deviations and local fluctuations of concentration and structural order.     

Preparation of poly(methyl methacrylate) macromonomer by radical polymerization in the presence of methyl α-(bromomethyl)acrylate and copolymerization of the resultant macromonomer

Radical polymerization of methyl methacrylate (MMA) in the presence of methyl -(bromomethyl) acrylate yielded poly-(MMA) bearing the 2-methoxycarbonylallyl end group through chain reaction involving bimol ecular termination. The molecular weight of the resultant polymer was effectively controlled with a small amount of the bromomethylacrylate added; the chain transfer constant was estimated to be 0.9. The poly (MMA) with the unsaturated end group (

Viscoelastic properties of Japanese lacquer film

The storage modulus (E′) and loss modulus (E″) of Japanese lacquer films were measured over a temperature range of −150 to 400°C. Three relaxation processes labeled α, β, and γ were detected at 80, −60, and −140°C, and their apparent activation energies (ΔE) were 63–91, 13, and 9 kcal/mol, respectively. These were attributed to the micro-Brownian motions of polymerized urushiol, the molecular motion related to the absorbed water, and the motions of methylene groups in the side chains, respectively. With aging at room temperature, the location of the α peak shifted to higher temperature and its ΔE value decreased. This result was ascribed to the autoxidative polymerization of urushiol. The E′ of lacquer films increased with heat treatments at 100°C or above. When treated at temperatures below 200°C, the location of the α peak shifted to higher temperature, with a reduction in the ΔE value. Heat treatments at 200°C or above resulted in remarkable shrinkage and weight loss of films owing to the pyrolysis of lacquer constituents. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1727–1732, 1999     

Frequency domain discussions on PD signal propagation characteristics in GIS

The frequency dependency of PD signal propagation in GIS was investigated at an underground substation. Injecting dummy pulses into a GIS through its internal electrode, frequency spectra were measured by a spectrum analyzer at various points of the GIS. It is shown that this measurement is very reproducible and the signal propagation phenomena are independent of its direction. It is also clarified that the PD signal reduction phenomena are closely related with mode transfer from TEM to TE or TM. The major higher mode seems to be TE₁₁. Pulse waveforms were also measured with 65‐MHz bandpass filter. Their magnitudes are compared with the gain of the 65‐MHz component of the frequency spectra and good agreement is obtained. This implies the possibility of PD location by observing a frequency pattern with several bandpass filters. © 2000 Scripta Technica, Electr Eng Jpn 133(3): 9–17, 2000     

Analysis of the vehicle mix in the passenger-car sector in Japan for CO2 emissions reduction by a MARKAL model

Carbon dioxide (CO₂) emissions from the passenger-car sector in Japan are increasing rapidly and should be reduced cost-effectively in order to stabilize energy-related CO₂ emissions in Japan. The purpose of the present paper is to clarify the most cost-effective mix of vehicles for reducing CO₂ emissions and to estimate the subsidy that is necessary to achieve this vehicle mix. For this analysis, the energy system of Japan from 1988 to 2032 is modeled using a MARKAL model. The most cost-effective mix of vehicles is estimated by minimizing the total energy system cost under the constraint of an 8% energy-related CO₂ emissions reduction nationally by 2030 from the CO₂ emissions of 1990. Based on the results of the analysis, hybrid vehicles are the only type of clean-energy vehicle, and their share of the passenger car sector in 2030 will be 62%. By assuming the subsidization of hybrid vehicles, the same vehicle mix can be achieved without constraining CO₂ emissions. The peak of the total subsidy estimated to be necessary is 1.225 billion US$/year in 2020, but the annual revenue of the assumed 31 US$/t-C carbon tax from the passenger car sector is sufficient to finance the estimated subsidy. This suggests that we should support the dissemination of hybrid vehicles through subsidization based on carbon tax.     

Enhancement of enzymatic catalysis of Bacillus amyloliquefaciens α-amylase by nonionic surfactant micelles

Some enzymes are considerably more stable when formulated with nonionic surfactants than when formulated with anionic surfactants. The effect of a nonionic surfatant, polyoxyethylene mono-N-dodecyl ether (Brij 35; number of units of ethylene oxide moieties, 23), on the kinetic behavior of hydrolysis of amylopectin with Bacillus amyloliquefaciens α-amylase (BAA) was studied at a temperature of 25°C and a pH of 7.0. The hydrolytic rate was accelerated by the addition of the nonionic surfactant above its critical micelle concentration. Lineweaver-Burk plots for the enzymatic hydrolysis in the absence and presence of the nonionic surfactant at 0.5 to 2.5% (wt/vol) had linear relationships, and the kinetic parameters, K _m and k _cat were obtained. The value of k _cat was increased with an increased concentration of Brij 35, whereas the K _m value was approximately constant. Therefore, the increase in k _cat contributed to the acceleration of the apparent hydrolytic rate. The interaction of amylopectin with the surfactant was examined by a surface tension measurement, and the result confirmed the corresponding binding between the substrate and the surfactant. A fluorescence analysis due to tryptophan in BAA suggested that BAA bound to the nonionic micelles. The increase in k _cat suggested that hydrolytic catalysis at the micellar pseudophase was more efficient than that at the aqueous pseudophase. The enhancement of the catalytic rate contributed to the effective removal of food stains containing starch when BAA was added with Brij 35 in a laundry detergent washing test.     

Graphitization behavior of the implanted furan-resin-derived carbon

Ar or Xe ions were implanted into the fractured-faces or surfaces of as-carbonized glass-like carbon (GC) specimens for modification of the structure of them. Microstructural changes were examined by Raman spectroscopy, by scanning tunneling microscope (STM) and by transmission electron microscopy (TEM). It was found that the as-carbonized surfaces and fractured-faces of the specimens were changed to an amorphous structure by ion implantation. Implanted as-carbonized surfaces of specimens were restored nearly pristine structures after re-heat-treatment at 3000 °C. On the other hand, implanted fractured-faces of specimens resulted in well-developed structures after re-heat-treatment at 3000 °C. After re-heat-treatment at 3000 °C, the degree of graphitization on the implanted fractured-faces was higher than that on the pristine fractured-faces. It can be concluded that mobility of carbon atoms, or free face, seemed to play an important role on surface graphitization.     

Direct Synthesis of Phenylchlorogermanes from Metallic Germanium and Chlorobenzene Using Metal Chloride Catalysts

In the direct synthesis of phenylchlorogermanes, copper(I) chloride was the best catalyst among the metal chlorides tested, the products being diphenyldichlorogermane and phenyltrichlorogermane. The reaction mainly gave diphenyldichlorogermane; however at the beginning of the reaction, phenyltrichlorogermane was afforded by the reaction of chlorobenzene and dichlorogermylene formed from metallic germanium and chloride ion in the catalyst.