Reduction of Vibration in Concentrated Winding Permanent Magnet Synchronous Motor by Means of Skew Effects of Rotor

Global warming and the problem of successfully incorporating environmental safeguards are promoting the need for a more power‐efficient motor. Therefore, as a driving source, permanent magnet synchronous motors (PMSMs) with concentrated winding are widely used in a variety of fields. However, a PMSM with a concentrated winding generates more vibration than one with a distributed winding because of the radial electromagnetic force. This paper describes the effect of a new skewed rotor on the characteristics of a concentrated winding PMSM. We investigated this effect by three‐dimensional finite element method (3D FEM) analysis and measurement. We also demonstrate that the proposed rotor is effective in reducing the radial electromagnetic force without decreasing motor efficiency. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(2): 33–43, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22400     

Wind Force Coefficients for Designing Porous Canopy Roofs

Wind force coefficients for designing porous canopy roofs have been investigated based on a series of wind tunnel experiments. Gable, troughed and mono-sloped roofs were tested. The roof models were made of 0.5 mm thick perforated duralumin plates, the porosity of which was changed from 0 to about 0.4. Overall aerodynamic forces and moments acting on the roof model were measured in a turbulent boundary layer with a six-component force balance for various wind directions. The results indicate that the wind loads on canopy roofs generally decrease with an increase in porosity of the roof. Assuming that the roof is rigid and supported by the four corner columns with no walls, the axial forces induced in the columns are regarded as the most important load effect for discussing the design wind loads. Two loading patterns causing the maximum tension and compression in the columns are considered. Based on a combination of the lift and moment coefficients, the design wind force coefficients on the windward and leeward halves of the roof are presented for the two loading patterns as a function of the roof pitch and porosity. The effect of porosity is taken into account as a reduction factor of the wind loads.     

Use of polyethylene films photografted with 2‐(dimethylamino)ethyl methacrylate as a potential adsorbent for removal of chromium (VI) from aqueous medium

A new polymeric adsorbent material based on polyethylene (PE) was prepared by photografting of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) as a positively chargeable monomer to a PE film. The effects of the experimental parameters, such as the pH value, temperature, and grafted amount on adsorption of chromium(VI) (Cr(VI)) ions were investigated for the DMAEMA‐grafted PE (PE‐g‐PDAMEMA) films. The maximum adsorption capacity was obtained at the initial pH value of 3.0 for a PE‐g‐PDMAEMA film with 1.8 mmol/g and the maximum adsorption capacity obtained was higher than or compatible to those of many of the other polymeric adsorbents prepared for Cr(VI) ions. The adsorption kinetics obeyed the mechanism of the pseudo‐second order kinetic model and adsorption of Cr(VI) ions on PE‐g‐PDMAEMA films was well expressed by the Langmuir isotherm model. A high Langmuir adsorption constant suggests that the adsorption of Cr(VI) ions occurs between protonated dimethylamino groups and ions mainly through the electrostatic interaction. Cr(VI) ions adsorbed were successfully desorbed from a PE‐g‐PDMAEMA film in solutions of NaCl, NH₄Cl, NH₄Cl containing NaOH, and NaOH and a PE‐g‐PDMAEMA film was regenerated and repeatedly used for adsorption of Cr(VI) ions without appreciable loss in the adsorption capacity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43360.     

Blood Pressure Elevation of Tubular Specific (P)RR Transgenic Mice and Lethal Tubular Degeneration due to Possible Intracellular Interactions between (P)RR and Alternative Renin Products

The prorenin/renin receptor ((P)RR) is a multifunctional protein that is widely distributed in various organs. Despite intensive research for more than 20 years, this receptor has not been fully characterized. In this study, we generated mice overexpressing the tubular epithelial (P)RR gene ((P)RR-TG mice) to test the previously reported functional role of (P)RR by Ramkumar et al. in 2015 using tubular specific (P)RR KO mice. (P)RR-TG mice were maintained and analyzed in individual metabolic cages and were administered angiotensin II blocker (ARB), direct renin inhibitor (DRI), and bafilomycin, that is, vacuolar ATPase (V-ATPase) antagonist. (P)RR-TG mice were hypertensive and had alkalized urine with lower osmolality and Na⁺ excretion. ARB and DRI, but not bafilomycin, concurrently decreased blood pressure. Bafilomycin acidized urine of (P)RR-TG mice, or equivalently this phenomenon restored the effect of overexpressed transgene, suggesting that (P)RR functioned as a V-ATPase in renal tubules. Afterall, (P)RR-TG mice were mated with alternative renin transgenic mice (ARen2-TG), which we identified as intracellular renin previously, to generate double transgenic mice (DT-TG). Lethal renal tubular damage was observed in DT-TG mice, suggesting that intracellular renin may be a ligand for (P)RR in tubules. In summary, (P)RR did not substantially affect the tissue renin-angiotensin system (RAS) in our model of tubular specific (P)RR gene over-expression, but alternative intracellular renin may be involved in (P)RR signaling in addition to conventional V-ATPase function. Further investigations are warranted.     

Thermophysical properties of (U,Y)O2

We prepared polycrystalline pellets of (U,Y)O₂, containing YO_1.5 up to 11 mol.%. We performed indentation tests on the pellets, and evaluated the Young’s modulus and hardness. We measured the heat capacity and the thermal diffusivity, and evaluated the thermal conductivity. We succeeded in evaluating the effect of Y content on the thermophysical properties of (U,Y)O₂. We revealed that the Young’s modulus, hardness, and thermal conductivity of (U,Y)O₂ decreased with increasing the Y content.     

Continuous synthesis of Zn2SiO4:Mn fine particles in supercritical water at temperatures of 400-500 °C and pressures of 30-35 MPa

Sub-micron sized Zn₂SiO₄:Mn²⁺ phosphors particles were continuously synthesized in supercritical water with a flow reactor. Colloidal silica or sodium silicate was used as the Si source. Zn and Mn sources were chosen from their nitrates, sulfates, and acetates. The syntheses were carried out at temperatures from 400 to 500 °C, at pressures from 30 to 35 MPa, at NaOH concentrations from 0.014 to 0.025 M, and for residence times from 0.025 to 0.18 s. Sodium silicate formed α- and β-Zn₂SiO₄:Mn²⁺ phases regardless of the Zn and Mn sources, while colloidal silica formed phases dependent on the type of Zn and Mn sources used in addition to the use of alkali. As the reaction temperature increased, the crystallinity of α-Zn₂SiO₄:Mn²⁺ phase increased and the Mn substitution into the Zn sites of the α-Zn₂SiO₄ phase decreased. Of the conditions studied, the most highly crystalline α-Zn₂SiO₄:Mn²⁺ was produced at a temperature of 400 °C, a pressure of 30 MPa, a NaOH concentration of 0.14 M, and a residence time of 0.13 s with Zn and Mn sulfates and colloidal silica as starting materials. The α-Zn₂SiO₄:Mn²⁺ fine particles synthesized were round in shape, had an average diameter of 268 nm, and exhibited a green-emission with a peak wavelength of 524 nm.     

Thermal transients during processing of materials by very high power ultrasonic additive manufacturing

Dynamic recrystallisation at interfaces has been suggested as the bonding mechanism in the joining of metallic tapes, during very high power ultrasonic additive manufacturing. To understand the reasons for such occurrence of dynamic recrystallization, thermal transients from the interface regions were recorded during processing of aluminum alloy (3003 and 6061 series) and 11 000 copper tapes under similar conditions. Measurements in 3003 Al were also carried out for different processing parameters. Measured peak temperatures were seen to increase with increase in shear strength of the material and ultrasonic vibration amplitude. The observations have been rationalized based on interfacial heating at asperities due to adiabatic plastic deformation.     

Growth of bubbles containing plasma in water by high-frequency irradiation

Plasma was generated in water by irradiation at high frequency of 13.56 MHz, and the behavior of bubbles including the plasma was observed by a high-speed camera. The generation pattern of the bubbles was classified into four types according to liquid temperature and supplied power. Conducting the simulation, the maximum temperature in the bubble was found to be from 3500 K to 4300 K, and the decomposition of water molecule occurred. The gas in the bubble was found to become high ratio of hydrogen. The phenomenon can be regarded as a film boiling of exceptionally high heat flux.     

An immuno-wall microdevice exhibits rapid and sensitive detection of IDH1-R132H mutation specific to grade II and III gliomas

World Health Organization grade II and III gliomas most frequently occur in the central nervous system (CNS) in adults. Gliomas are not circumscribed; tumor edges are irregular and consist of tumor cells, normal brain tissue, and hyperplastic reactive glial cells. Therefore, the tumors are not fully resectable, resulting in recurrence, malignant progression, and eventual death. Approximately 69–80% of grade II and III gliomas harbor mutations in the isocitrate dehydrogenase 1 gene (IDH1), of which 83–90% are found to be the IDH1-R132H mutation. Detection of the IDH1-R132H mutation should help in the differential diagnosis of grade II and III gliomas from other types of CNS tumors and help determine the boundary between the tumor and normal brain tissue. In this study, we established a highly sensitive antibody-based device, referred to as the immuno-wall, to detect the IDH1-R132H mutation in gliomas. The immuno-wall causes an immunoreaction in microchannels fabricated using a photo-polymerizing polymer. This microdevice enables the analysis of the IDH1 status with a small sample within 15 min with substantially high sensitivity. Our results suggested that 10% content of the IDH1-R132H mutation in a sample of 0.33 μl volume, with 500 ng protein, or from 500 cells is theoretically sufficient for the analysis. The immuno-wall device will enable the rapid and highly sensitive detection of the IDH1-R132H mutation in routine clinical practice.     

A mass separation of chondrocytes from cartilage tissue utilizing an automatic crushing device

Porcine articular cartilage tissue was crushed using Multi-Beads-Shocker^™ and digested with trypsin and collagenase type II. Chondrocyte cell yield was maximized by automatic crushing for 10 s, which was 4 times that by manual dicing with a surgical blade and might be useful for the automation of the cell processing.