Friction and wear behaviors of rolling bearing were studied in contaminated oil containing white fused alumina particles. The friction and wear processes were monitored using a spectrometric oil analysis program (SOAP) and vibration measurement method. Alumina particles were 3 and 16μm in size. The particles were mixed with turbine oil (ISO VG 46) and the concentration was varied in the range of 0 to 0.15g/l. The following conclusions were obtained in this study. (1) The contaminant did not affect strongly on the friction coefficient when the size was 3μm. In contrast, the friction coefficient decreased significantly when the size was 16μm and the concentration was above 0.1g/l. (2) Iron element concentration increased with the run time in the contaminated oil. The increasing rate became high as the contaminant size increased. (3) The contaminant particles accelerated fatigue wear that caused flaking on the inner and outer ring surfaces. Abrasive wear due to rolling and sliding of contaminant was predominant on the ball and retainer. (5) The probability density function of vibration waveform changed significantly depending on the wear of bearing.

View full abstract

In this research, a cheap color distinction device has been developed. The developed color distinction device emits light of R → G → B in order at intervals of about 4sec with the high output LED.The reflected light is received by the phototransistor, and the voltage proportional to the amount of light as output. The microcontroller synchronizes with the luminescence trigger and takes in data of voltage of RGB. The data is converted from the analogue into digital, and displayed in the indicator. The color that is passing of can be judged by the displayed data. The performance of high output LED color distinction device was compared with the commercial color sensor. By the high output LED color distinction device,it is confirmed that the distinction of the color is easy.

View full abstract

We previously proposed a planar parametric transformer using a laminated Si-Fe core. In that study, it was noted that there was a relationship between the shape of the magnetic path and the trajectory of the operating point. In this paper, we report on the following: (1) the trajectory of the operating point in the transformer moves parallel to the q'-axis in the a'-q' plane for a shape of the magnetic path, indicating that parametric oscillations are stable. (2) the trajectory of the operating point approaches the area where the parametric oscillations stops, because approximated coefficients changes with the shape of the magnetic path. (3) the trajectory of the operating point is affected by the approximate coefficients of first-order and fifth-order polynomials for the magnetic flux of the magnetic saturation curve. These states of a transformer were analyzed using MATLAB.

View full abstract

The synergistic extraction of trivalent rare earth elements (RE) has been investigated by a mixture of 1-(2-pyridylazo)-2-naphthol(PAN, HA), and a neutral ligand, 5,6-dimethyl-1,10- phenanthroline (dmp) in toluene. The synergistic enhancement of the extraction of RE(III) occurred by the addition of dmp, and extraction constants with PAN alone and those in the presence of dmp were evaluated. The synergistic enhancement decreased with increasing atomic number of lanthanoids.

View full abstract

Silica fibers coated with alumina layers have been prepared using a solution of aluminum nitrate dissolved in 1,3-butanediol. The alumina layer usually had a homogeneous flat surface. However,the alumina layer transformed to crude assemblies of alumina particles after aging the alumina-modified silica fiber in deionized water at 100 ℃ . The fibrils alumina supported on silica fiber kept large surface area after the exposure to steam at higher temperature. When Ni was impregnated on alumina, the catalyst demonstrated the excellent catalytic performance in CH_4 steam reforming without the deactivation at higher temperature.

View full abstract

Resorcinol cyclic tetramer(n-Host) and its derivative(a-Host) interact with polar organic compounds such as sugars, alcohols and carboxylic acids via multiple hydrogen-bonding. The hosts extract polyphenols from water solution to a nonpolar organic solvent via same manner. Polyphenols used are chlorogenic acid, gallic acid, ellagic acid and rutin. Especially, a-host having polar binding space strongly interacts with gallic acid. From extraction of another polyphenols such as di- and trihydroxybenzenes, it was shown that trihydroxybenzene part is necessary structure for this strong interaction.

View full abstract

The ubiquinol-cytochrome c oxidoreductase (cytochrome bc_1) complex is an integral membrane protein complex and an essential segment of the electron transport chain in photosynthetic bacteria.This complex catalyzes electron transfer from ubiquinol to the high potential iron-sulfur protein in the thermophilic purple sulfur photosynthetic bacterium Thermochromatium (T.) tepidum. In this study, the cytochrome bc_1 complex was isolated from T. tepidum and the redox potential of pigments (heme c, heme b_H, heme b_L) in this complex was determined by chemical titration that measured the absorbance changes for potential. The cytochrome bc_1 complex solution for chemical titration was prepared by adding some mediators, KCl, β-D-glucose, glucose oxidase, catalase. The potential of the solution was measured by potentiostat. As a result of fitting the Nernst equation for the absorbance changes, the redox curve was obtained and the redox potentials of heme c_1 and heme b were 0.189 V, 0.000 V..

View full abstract

Recently, we isolated 2 types of wild yeast, named as HK2205 and HK2206, from cherry blossom planted at Hachinohe National College of Technology (HNCT). These yeast strains indicated alcohol fermentation activity equivalent to beer yeast. In this study, we tried the analysis of alcohol resistance activity and killer toxin activity, and identified the species by DNA sequencing. In the result, HK2206 yeast strain was identified as Saccharomyces cerevisiae which was the most popular brewery yeast, and exhibited high alcohol resistance activity and non-killer toxic activity. Thus, HK2206 was evaluated with promising for new brewage.

View full abstract

We propose a characteristic Galerkin scheme using B-spline basis functions for one-dimensional advection diffusion problems. One of significant features of the B-spline basis functions is that the B-spline basis functions of p degrees have at most C^p-1 continuous derivatives although classical finite elements based on Lagrange polynomials have only C^0 continuous derivatives. The feature works better for the characteristic Galerkin scheme. In order to confirm effectivity of the present scheme, we perform some numerical experiments and compare results of the present scheme with the SUPG scheme using the same basis functions.

View full abstract

An extension lecture meeting on the Great East Japan Earthquake was held on July 2011. The lecture meeting was geared toward junior high school students to raise their awareness of disaster prevention. This report provided a summary of the lecture on the disasters caused by the great earthquake.

View full abstract

It is essential for the students specialized in engineering to have a certain competence in English. In a College of Technology in Japan, they start their course when they are still as young as in upper secondary education. To prepare the students for the later education, it is better to start their learning of basic sciences such as physics, chemistry, biology, earth sciences, and so on, in English as early as possible. Using science textbooks for secondary school students in English speaking countries is a way to meet the needs. We have been using a science textbook in several courses. The results and problems are reported.

View full abstract