Continuous path control of a 5-DOF parallel-serial hybrid robot

Using the 5-degree of freedom parallel-serial hybrid robot, to realize the de-burring, new forward and inverse kinematic calculation methods based on the “off-line teaching” method are proposed. This hybrid robot consists of a parallel stage section and a serial stage section. Considering this point, each section is calculated individually. And the continuous path control algorithm of this hybrid robot is proposed. To verify the usefulness, a prototype robot is tested which is controlled based on the proposed methods. This verification includes a positioning test and a pose test. The positioning test evaluates the continuous path of the tool center point. The pose test evaluates the pose on the tool center point. As the result, it is confirmed that this hybrid robot moves correctly using the proposed methods.     

Cross-section analysis of electric devices by scanning capacitance microscope

Carrier influence of semiconductor devices is important as it affects the function of the device. In this experiment, the carrier density distribution in the cross-section of semiconductor device was analyzed by SCM: Scanning Capacitance Microscope which is one of the measuring mode of SPM: Scanning Probe Microscope.This paper describe measurement result of change in carrier density by the gate voltage at p channel area of CMOS device and its efficiency to investigating dopant profile on 16MDRAM cross-section.     

A study on horizontal stud welding by using steel stud for flat welding

ABSTRACT

In recent years, manufacturing sites have strongly requested for the steel stud with large diameter to be welded in the horizontal position, which is difficult because of gravity. In this study, the steel stud of 19 mm in diameter was welded horizontally to the mild steel plate by using ferrule for usage in flat position. As results two kinds of weld defect were observed; lack of fusion and blowhole. The former occurred in the welding condition of too small or too large heat input, and the latter did in the range of longer arc time. Therefore, the suitable welding condition could be found in the large current and shorter arc time. When the areal ratio of weld defect to the cross section of stud was lower than 10 percent, the welded joint had enough statical strength.     

Simulation study of the influence of different urban canyons element on the canyon thermal environment

The heat island effect is an important issue for large cities, especially those located in hot and moist climates. The phenomenon is more severe in urban canyons because surrounding high-rise buildings allow little ventilation and dissipation of heat caused by traffic. The primary goal of the present study is to investigate the thermal environment of a major street in Osaka by intensive measurement during the summer of 2006. Osaka is the second largest city in Japan and suffers from the most severe heat island effect. In addition, several fundamental renovations and a composite renovation for the improvement of thermal environment in the urban canyon are proposed, and the efficacies of these measures are verified by computational fluid dynamics (CFD) simulation. It was found that by modifying the heights of buildings along the street and the ground surface materials and increasing the quantity of vegetation, the thermal environment can be improved by a 2.0°C. reduction in standard new effective temperature (SET^*) at maximum.     

Transient kinetic studies of pH-dependent hydrolyses by exo-type carboxypeptidase P on a 27-MHz quartz crystal microbalance

pH-Dependent kinetic parameters (k(on), k(off), and k(cat)) of protein (myoglobin) hydrolyses catalyzed by exo-enzyme (carboxypeptidase P, CPP) were obtained by using a protein-immobilized quartz crystal microbalance (QCM) in acidic aqueous solutions. The formation of the enzyme-substrate (ES) complex (k(on)), the decay of the ES complex (k(off)), and the formation of the product (k(cat)) could be analyzed by transient kinetics as mass changes on the QCM plate. The Kd (k(off)/k(on)) value was different from the Michaelis constant Km calculated from (k(off) + k(cat))/k(on) due to k(cat) > k(off). The rate-determining step was the binding step (k(on), and the catalytic rate k(cat) was faster than other k(on) and k(off) values. In the range of pH 2.5-5.0, values of k(on) gradually increased with decreasing pH showing a maximum at pH 3.7, values of k(off) were independent of pH, and k(cat) increased gradually with decreasing pH. As a result, the apparent rate constant (k(cat)/Km) showed a maximum at pH 3.7 and gradually increased with decreasing pH. The optimum pH at 3.7 of k(on) is explained by the optimum binding ability of CPP to the COOH terminus of the substrate with hydrogen bonds. The increase of k(cat) at the lower pH correlated with the decrease of alpha-helix contents of the myoglobin substrate on the QCM.     

The microwave effect on the properties of silica-coated TiO2 fine particles prepared using sol-gel method

The silica coating of TiO₂ fine particle was conducted using microwave assisted sol-gel method and conventional sol-gel method to suppress its photo-catalytic activity. The amount and uniformity of silica coating on TiO₂ surface were characterized by X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential measurements. XPS and XRF results showed that the presence of catalyst and reaction time were important factors to reach high silica amounts. SEM, TEM, and zeta potential results indicated that dense film coating of SiO₂ layer formed on TiO₂ surface in conventional sol-gel method, whereas the nucleation coating was observed on sample prepared by microwave assisted sol-gel method. When photo-catalytic activities and ultraviolet (UV) shielding abilities of these samples were evaluated, the sample prepared by microwave processing showed higher inhibition of photo-catalytic activity and better UV shielding ability than the sample prepared by conventional method. These results suggested that the coating method significantly affected the photo-catalytic activity and UV shielding ability of coated TiO₂.     

Analysis of biphasic lubrication of articular cartilage loaded by cylindrical indenter

Combination of theoretical biphasic analyses and corresponding experimental measurements for articular cartilage has successfully revealed the fundamental material properties and time-depending mechanical behaviors of articular cartilage containing plenty of water. The insight of load partitioning between solid and fluid phases advanced the prediction of the frictional behavior of articular cartilage. One of the recent concerns about biphasic finite element (FE) analysis seems to be a dynamic and physiological condition in terms of mechanical functionality as a load-bearing for articular joint system beyond material testing, which has mainly focused on time-dependent reaction force and deformation in relatively small and low speed compression. Recently, the biphasic FE model for reciprocating sliding motion was applied to confirm the frictional effect on the migrating contact area. The results indicated that the model of a cylindrical indenter sliding over the cartilage surface remarkably sustained the higher proportion of fluid load support than a condition without migrating contact area, but the effectiveness of constitutive material properties has not been sufficiently evaluated for sliding motion. In our present study, at the first stage, the compressive response of the articular cartilage was examined by high precision testing machine. Material properties for the biphasic FE model, which included inhomogeneous apparent Young's modulus of solid phase along depth, strain-dependent permeability and collagen reinforcement in tensile strain, were estimated in cylindrical indentation tests by the curve fitting between the experimental time-dependent behavior and FE model simulation. Then, the biphasic lubrication mechanism of the articular cartilage including migrating contact area was simulated to elucidate functionality as a load-bearing material. The results showed that the compaction effect on permeability of solid phase was functional particularly in the condition without the migrating contact area, whereas in sliding condition the compaction effect did not clearly show its role in terms of the proportion of fluid load support. The reinforcement of solid phase, which represented the collagen network in the tissue, improved the proportion of fluid load support especially in the sliding condition. Thus, a functional integration of constitutive mechanical properties as a load-bearing was evaluated by FE model simulation in this study.     

Mutational analysis of the metabolism of 2,6-naphthalenedisulfonate by Pigmentiphaga sp. NDS-2

The metabolism of 2,6-naphthalenedisulfonate (26NDS) by Pigmentiphaga sp. NDS-2 was analyzed by isolating a mutant (NDS2-002) which slowly grew on a minimal medium containing 26NDS as the sole source of carbon. Liquid chromatography/mass spectrometry (LC/MS) analysis of metabolic intermediates in this strain revealed that 5-sulfosalicylate (5SSA) is accumulated during the degradation of 26NDS. To analyze the lower metabolic pathway, a mutant strain NDS2-008, which could not grow either on 26NDS, 5SSA or gentisate, but could on succinate as the carbon source, was isolated. When the resting cells of NDS2-008 were incubated with 5SSA or gentisate, a substance deduced to be maleylpyruvate (Zhou et al., J. Bacteriol., 183, 700-708, 2001) was commonly detected upon HPLC analysis. These results suggest that Pigmentiphaga sp. NDS-2 degrades 26NDS via 5SSA, gentisate and maleylpyruvate as intermediates.     

CeO2–ZrO2 Solid Solution Catalyst for Selective Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide

CeO₂–ZrO₂ solid solution catalysts are very effective for the selective synthesis of dimethyl carbonate from methanol and CO₂. The activity was much dependent on the calcination temperature. The higher the calcination temperature, the higher the activity of the catalyst for DMC formation, though the BET surface area is lower on the catalyst calcined at higher temperature.