Effects of Winding Attachment Positions on Output Characteristics of Flux‐Modulating Synchronous Machines

The flux‐modulating synchronous machine (FMSM) is a new type of multipole SM with nonoverlapping concentrated armature and field windings on the stator. This paper compares the output characteristics of two FMSMs through finite element analysis (FEA) and experiments. In both of the FMSMs, the attachment positions of the armature and field windings are swapped. To determine the reason for the discrepancies in their output characteristics, unsaturated inductances were calculated using a d‐‐q equivalent circuit. In addition, the calculated results of the inductances were confirmed through a visualization of the leakage fluxes using FEA. The results of the study show that the synchronous inductance can be reduced by attaching the armature winding to the air‐gap side of the stator teeth and that the reduction leads to an increase in output power.     

Correlation between motion of source bender element and feedback signal induced by self-monitoring

Since the introduction of bender element tests to soil testing, the reliability of the estimated travel time has been the most serious problem. The author has previously shown a potential solution whereby removing the response of the bender element subsystem from the whole response could dramatically improve the accuracy of the travel time estimation. In order to lay the foundation for estimating the response of the bender element subsystem, this paper examines the correlation between the displacements of the element and the induced feedback signals by employing a self-monitoring element. The response of the self-monitoring element is modeled as a transfer function involving two internal transfer functions that relate the input signals to the displacements and the displacements to the feedback signals, respectively. Using a laser displacement sensor, the displacements are directly measured through the entire surface and reveal the three-dimensional bending motion of the element oscillating in both longitudinal and width directions. The feedback signals are similar to, but inconsistent with, the tip displacements, and an attempt is made to correct the feedback signals. Finally, a conclusion is given on the potential for estimating the response of the bender element subsystem using the self-monitoring element.     

二垩英与资源回收-Ⅰ考虑到二垩英生成的资源与能量回收基础研究

目前在日本,存在大量工业垃圾,包括各种塑料制品,ASR(汽车破碎垃圾),含有毒PCB(多氯联苯)的110变压器和PVC(聚氯乙稀)制品等.而来自城市垃圾焚烧炉的废气含有大量能量.因此,在充分考虑环境、避免二垩英生成的同时,安全回收来自工业垃圾、城市和/或工业垃圾焚烧炉的资源和能量是个非常重要的课题,这也将对抑制CO2排放作出贡献.正确地阐明焚烧过程中二垩英的生成机理及详细研究含少量二垩英的焚烧废气在冷却过程中大量形成二垩英的临界温度是项很重要的工作.解决这个问题可有效实现资源和能量的回收.本报告介绍日本在二垩英排放方面目前采取的对策和存在的问题以及大阪大学为阻止二垩英生成所做的基础研究工作.     

Reliability of Au bump––Cu direct interconnections fabricated by means of surface activated bonding method

As a room temperature bonding method, surface activated bonding (SAB) method has been introduced to be one of the most appropriate interconnection methods for the next generation of electronic packaging. Thus it is important to study the reliability of SAB interconnection in long term life test.In this paper, interconnections of Au bump and Cu film bonded by SAB method were performed in high temperature thermal aging test. Degradation of properties such as electrical resistance, shear strength of bump and interface microstructure during aging process were studied to investigate the failure mechanism of the interconnection. Intermetallic compound Cu₃Au was found formed at the interface during thermal aging, and it causes evolvement of the properties and failure mode of the interconnection changing in shear test. Results reveal that SAB is suitable for the interconnection between Au bump and Cu film and it is reliable in thermal reliability test.     

The heat transfer and pressure drop characteristics of finned tube banks in forced convection (effects of fin height on pressure drop characteristics)

In recent years the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. For example, in the power generation field, as thermal power generation occupied 60% of the power generation demand, considerable improvement of the thermal efficiency is required. This paper describes the pressure drop characteristics of finned tube banks used for heat exchangers in thermal power generation that were clarified by testing serrated finned tube banks with different fin heights for improved heat transfer and conventional spiral finned tube banks with different fin heights, and an equation to predict pressure drop which is necessary for the heat exchanger design is proposed. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 179–193, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20112     

Preparation of zirconia-toughened bioactive glass-ceramics

Bioactive glass-ceramics toughened by tetragonal zirconia polycrystal (TZP) were prepared by hot-pressing mixed powders of the MgO-CaO-P₂O₅-SiO₂ glass and TZP containing 20 to 80% alumina. The bending strength and the fracture toughness of the composite materials were improved compared with those of the material without TZP. These composites showed high bending strengths (400 to 500MPa) and high fracture toughness ( 2.8MPa m^1/2). The existence of a crack deflection mechanism was observed by scanning electron microscopy. After soaking in simulated physiological solution at 100 °C, no phase transformation from tetragonal to monoclinic of TZP in the composites and no degradation in bending strength occurred.     

Humidity Sensor Characteristics of Woodceramics

The humidity sensor characteristics of Woodceramics were investigated. The Woodceramics used in this experiment were prepared at 650–900°C. The size of specimens selected was 1 × 1 × 10 mm . One was used as-cut and the other was polished. Above 700°C, the resistance of the specimen was below 50 and the decrease of resistance with increasing relative humidity was small. The specimen prepared at 650°C had a resistance of about 1 k. The resistance of as-cut specimens decreased with increase in relative humidity, but that of the polished specimen did not change significantly. The difference between as-cut and polished samples was explained by the differences in surface micro-structure.     

Laser-Sintered Barium Titanate

Laser sintering of alkoxy-derived ultrafine BaTiO₃ powders was investigated. The temperature increases of the sample with laser irradiation were measured with a thermocouple. It was found that laser irradiation could generate enough heat to sinter ceramics. A slurry was prepared by mixing an alkoxy-derived BaTiO₃ powder, binder additives, solvent, and plasticizer. The slurry was tape cast and dried to give a green sheet. The green sheet was laser sintered and was then characterized by SEM, XRD, and density measurements. The effect of burnout before laser irradiation and the characteristic microstructure of laser-sintered BaTiO₃ are described.     

Application of enzymatically gelled chitosan solutions to water‐resistant adhesives

An investigation was undertaken on the application of dilute chitosan solutions gelled by tyrosinase‐catalyzed reaction with 3,4‐dihydroxyphenethylamine (dopamine). The tyrosinase‐catalyzed reaction with dopamine conferred water‐resistant adhesive properties to the semidilute chitosan solutions. The viscosity of the chitosan solutions increased highly by the tyrosinase‐catalyzed reaction and the subsequent reactions between o‐quinone compounds and chitosan. These highly viscous, gel‐like modified chitosan materials were allowed to spread onto the surfaces of the glass slides, which were tightly lapped together and held them in water. Tensile shear adhesive strength of over 400 kPa was observed for the modified chitosan samples. The increase in the amino group concentration of the chitosan solutions and the molecular mass of the chitosan used effectively led to the increase in adhesive strength of the glass slides. In addition, in the case where the chitosan solution was gelled by the enzymatic reaction with dopamine in the presence of poly(ethylene glycol), adhesive strength sharply increased at shorter reaction times concomitantly with the increase in the viscosity of the chitosan solutions because the tyrosinase activity effectively was retained by poly(ethylene glycol). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1818–1827, 2007