Air gap flux analysis for cage rotor diagnosis

The relationship between the magnetomotive force distribution of a three-phase induction motor and various cage rotor faults, such as broken bars and end rings, is discussed in detail. Search coil output and its harmonic components are analyzed to allow the determination of faults from the air-gap flux density. The results obtained in tests on a motor into which faults were intentionally introduced confirm the effectiveness of this method of analysis.     

Inhibition of liver metastasis of human pancreatic carcinoma by angiogenesis inhibitor TNP-470 in combination with cisplatin

The anti-tumor and anti-metastatic effects of O-(chloroacetyl-carbamoyl) fumagillol (TNP-470), an angiogenesis inhibitor, and cisplatin (CDDP), an anti-neoplastic agent, were investigated using our established liver-metastasizing pancreatic carcinoma line, HPC-3H4. HPC-3H4 was injected into the spleens of nude mice. Mice were randomly divided into 5 groups; a control group given saline solution, a group receiving 45 mg/kg TNP-470, a group receiving 90 mg/kg TNP-470, a group receiving 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP, and a group receiving 0.25 mg/kg CDDP. In the control group, liver metastasis developed in 14 of 15 mice (93.3%). Liver metastasis developed in 9 of 11 mice (81.8%) receiving 0.25 mg/kg CDDP. It developed in 11 of 15 mice (73.3%) receiving 45 mg/kg TNP-470, in 17 of 18 mice (94.4%) receiving 90 mg/kg TNP-470, and in 4 of 10 mice (40%) receiving 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP. TNP-470 in combination with CDDP displayed a significant inhibitory effect on liver metastasis compared to the control. Although TNP-470 alone and CDDP alone had no effect on the tumor growth in vivo, 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP had a significant effect. In vitro examinations demonstrated that the growth of HPC-3H4 cells was only mildly inhibited by TNP-470, but the production of vascular endothelial growth factor (VEGF) by HPC-3H4 was clearly inhibited by TNP-470. The inhibitory effect on the production of VEGF was not strong with CDDP treatment. These results indicate that the angiogenesis inhibitor TNP-470 in combination with low-dose CDDP has inhibitory activity against liver metastasis of human pancreatic carcinoma.     

Polyacrylonitrile/Nylon 6 Blends: Preparation and Characterization

Summary: Polyacrylonitrile (PAN) particles with micro‐size ranges (0.15–2 μm) were prepared by emulsion and dispersion polymerizationa and in supercritical carbon dioxide media. The PAN particles were blended with Nylon 6 (PA6) at 220 °C by using a miniature mixer; it was found that melt‐mixing was possible for PAN‐rich compositions as high as 70 wt.‐%. Blends were characterized by scanning electron microscopy, IR, viscosity measurements, differential scanning calorimetry, and dynamic mechanical thermal analysis (DMTA). The size and shape of original PAN particles were retained in PAN/PA6 blends. The useful range to blend PAN particles size was less than 1 μm in terms of shape retention of the PAN particles in blends. Blends with 40 wt.‐% PAN content were found to be melt‐processable. The elastic modulus was higher for PAN/PA6 blends than pure PA6.

SEM photograph of PAN‐SC/PA6 blend with a 40/60 weight ratio.     

Design of discrete time adaptive PID control systems with parallel feedforward compensator

This paper deals with the design of an adaptive PID control system with a parallel feedforward compensator (PFC) for discrete-time SISO systems and its application to water level control of a 3-tank system. The proposed method utilizes the characteristics of almost strict positive realness (ASPR) of the controlled plant. A conventional design scheme of a PFC which realizes an ASPR augmented controlled plant is also proposed. Further it is shown that the introduction of an internal model improves the control performance of the control system with the PFC. The effectiveness of the proposed method is confirmed through water level control experiments on a three-tank SISO system.     

Simultaneous three-dimensional step-height measurement and high-resolution tomographic imaging with a spectral interferometric microscope

A noncontact, nonmechanical scanning, wide-field spectral interference microscope is developed for simultaneous measurement of three-dimensional step-height of discontinuous objects and tomographic imaging. A superluminescent diode (SLD) is used as a broadband light source and a liquid-crystal Fabry-Perot interferometer (LC-FPI) as a frequency-scanning device. By means of changing the injection current to the SLD, the spectral profile of the SLD is equalized, and a constant light input to the interferometer is achieved over the entire frequency-scan range. The Fourier-transform technique is used to determine both the amplitude and the phase of spectral fringe signals. Three-dimensional height distribution of a discontinuous object is obtained from the phase information, whereas optically sectioned images of the object are obtained either from the amplitude information alone or from the combination of both the amplitude and phase information. Experimental results with submicrometer resolution are presented for both step-height measurement and tomographic sectioning.     

Spectral interferometric microscope with tandem liquid-crystal Fabry-Perot interferometers for extension of the dynamic range in three-dimensional step-height measurement

The maximum measurable range of a spectral interference microscope depends on the coherence length of the light transmitted by its tunable spectral filter. To achieve a large range in step-height measurement we have developed a new tunable spectral filter that uses tandem liquid-crystal Fabry-Perot interferometers (LC-FPIs), which can simultaneously attain both a high spectral resolution and a large tuning range. Fringe visibility measurements were carried out, and it was found that the coherence length of the light transmitted through tandem LC-FPIs is two times larger than that transmitted through a single LC-FPI. Using this novel tunable spectral filter, we developed a new spectral interference microscope for the measurement of three-dimensional shapes of discontinuous objects. Experimental results of step-height measurements both with a single LC-FPI and with tandem LC-FPIs are presented for a combination of standard steel gauge block sets with 1-, 99-, and 100-microm steps. A large range (1-100 microm) of measurement with submicrometer resolution was achieved with tandem LC-FPIs that was not possible with our previous system in which a single LC-FPI was used.     

Cloning of a fatty acid synthase component FAS1 gene from Saccharomyces kluyveri and its functional complementation of S. cerevisiae fas1 mutant

A gene encoding a fatty acid synthase component, FAS1, has been cloned from a genomic library of the polyunsaturated fatty acid (PUFA)-producing yeast Saccharomyces kluyveri. This gene (named Sk-FAS1) was found to contain an open reading frame of 6150 bp, coding for 2049 amino acids. The deduced Sk-FAS1 protein showed significant (75-59%) homology with FAS proteins from the other yeasts, including S. cerevisiae, Candida albicans and Yarrowia lipolytica. The substrate-binding sites of the acetyl transferase and malonyl/palmitoyl transferase domains, and the FMN- and NADPH-binding sites of the enoyl reductase domain, were all highly conserved. Expression of the Sk-FAS1 gene in S. cerevisiae complemented genetic disruption of the S. cerevisiae FAS1 gene (Sc-FAS1), suggesting the formation of a heterogeneous complex of Sk-FAS1 (beta) and Sc-FAS2 (alpha), which is able to function to synthesize fatty acids. Compared with the isogenic wild-type of S. cerevisiae, as well as S. kluyveri, the S. cerevisiae fas1 mutant carrying the Sk-FAS1 gene showed an increase in the relative amount of 16-carbon fatty acids and a decrease in 18-carbon fatty acids.     

Study on the Anti-Coking Nature of Ni/SrTiO3 Catalysts by the CH4 Pyrolysis

A solid phase crystallization (spc) method was applied for the preparation of SrTiO₃-supported Ni catalysts and compared to the impregnation (imp) method. spc-Ni_0.2/SrTiO₃ has highly dispersed and stable Ni metal particles resulting in higher activity and higher sustainability against coking than imp-Ni_0.2/SrTiO₃ in the partial oxidation of CH₄. Both catalysts were tested for the CH₄ pyrolysis in order to elucidate the catalytic nature against coking of spc-Ni_0.2/SrTiO₃. The amount of carbon and the rate of H₂ formation were similar over both catalysts at both 773 and 1073 K. On both catalysts, CH₄ continuously decomposed at 773 K, while the rate of CH₄ pyrolysis quickly decreased at 1073 K. Fibrous carbons grew up with a Ni metal particle on the tip of the fiber at 773 K, while carbon balls and short carbon fibers with a Ni metal particle encapsulated inside formed and no sufficient growth of the fiber was observed at 1073 K. The carbon species formed at 773 K was hydrogenated completely to CH₄ around 873 K, while the hydrogenation of that formed at 1073 K needed higher temperature around 1073 K. However, the carbon species formed on both the catalysts at either 773 or 1073 K was completely oxidized around 773 K. Thus, judging from the anti-coking nature, the behaviors in the CH₄ pyrolysis are similar over both catalysts, nonetheless spc-Ni_0.2/SrTiO₃ was far superior to imp-Ni_0.2/SrTiO₃ in the CH₄ oxidation. It is likely that the high sustainability against coking of spc-Ni_0.2/SrTiO₃ is not due to its intrinsic nature suppressing the coking but due to its high activity of reforming which can quickly eliminate the carbon formed on the catalyst surface.