A Verification of Estimation Accuracy of Lightning Current Waveform and Charge Transfer from Measured E‐Field Waveform

To establish effective countermeasures on power facilities against lightning damage, it is necessary to clarify the lightning characteristics such as current parameters at the area of interest. In order to collect lightning current parameters effectively, the authors have observed electric and magnetic field waveforms simultaneously at south Kyushu, where the lightning flash density in summer is high. Based on observed electric field waveforms, the lightning current parameters have been estimated by adopting the Diendorfer–Uman model (DU model) as the return‐stroke model. In this paper, the accuracy of the estimated return‐stroke current waveform is verified by comparison with directly measured return‐stroke current waveform, along with the accuracy of the estimated charge transfer from the electric field waveform measured with a slow antenna.     

Analytical Method Applying a Mathematical Model for Axial‐Gap‐Switched Reluctance Motor

In this paper, an analytical method using a mathematical model for switched reluctance motors (SR motors) is proposed. The feature of this method is the representation of the effect of the mutual flux on the integral model by applying transient analysis utilizing preprocessed inductance tables. The advantage of this method is that the analysis time is reduced in comparison with the finite element method (FEM). The calculation results for the torque show little difference between the FEM and the proposed method, and the computation time was shortened. A 3.7‐kW prototype axial‐gap SR motor designed using the proposed method delivered the specified performance.     

Improved Modified Switching Transient Pulse Width Modulation (MT‐PWM) Method Applied to H‐Bridge Type Step‐Down Converter

The authors have devised a new method to decrease high‐frequency harmonics in a specific frequency band by modifying the switching transient slope. In previous studies, there were several problems in applying modified transient pulse width modulation (MT‐PWM) to actual converters. In this paper, three problems are solved using an improved MT‐PWM method. First, the MT‐PWM signal was obtained using a trial‐and‐error approach that involved complex computation procedures in the previous studies. In this paper, a new calculation procedure for obtaining the MT‐PWM waveform using a simple calculation is proposed. Second, a new controller (drain‐source voltage controller) based on voltage feedback is proposed in order to realize a modified switching transient to increase the stability of the switching operation. Third, the dependency of MT‐PWM on source voltage variation is investigated in order to implement MT‐PWM in an actual step‐down converter. From this result, the concept of a new type of controller with the source voltage variation taken into consideration is proposed. Finally, the authors attempted to apply MT‐PWM to an H‐bridge converter to expand the application of MT‐PWM. An H‐bridge converter with MT‐PWM for a dc motor drive is successfully operated in an experiment.     

Development of Electrolytic Capacitor Less Photovoltaic Grid Connected Inverter with Boost‐Up Type Active Buffer Circuit

This paper proposes a configuration of a single‐phase voltage source inverter that features power decoupling capability. Generally, the converter connected to a single‐phase grid employs bulky dc link capacitors such as electrolytic capacitors in order to decouple the power ripple with twice the frequency of the power supply. The power ripple in the proposed circuit is compensated by an active buffer with small capacitors. In this paper, the fundamental operations of the proposed converter are confirmed by experimental results. From the experimental results, the output current total harmonic distortion (THD) is 3.51%, the ratio of the input current is 14.3%, and the output power factor is over 99%. In addition, the volume of the proposed circuit is reduced by 61% when the carrier frequency is 64 kHz compared to that with a carrier frequency of 16 kHz. Finally, from an evaluation of the power density using Pareto front curves, the proposed circuit achieves high power density in comparison with the conventional circuit.     

Gel Forming Characteristics of Frozen Surimi from Chum Salmon in the Presence of Protease Inhibitors

When salted surimi paste of chum salmon was incubated at 20–60°C, a marked loss of the breaking strength of heat-induced gel occurred simultaneously with breakdown of myosin heavy chain, but this was effectively suppressed by addition of cysteine protease inhibitors or bovine plasma powder. In the presence of protease inhibitor, the surimi gels were formed at relatively low temperatures showing highest gel strength at incubations of 50 and 60°C. Chum salmon surimi showed no evidence of suwari and no myosin heavy chain cross-linking.     

MILK BASIC PROTEIN ENHANCES THE BONE STRENGTH IN OVARIECTOMIZED RATS

We studied the effects of milk basic protein (MBP) on bone metabolism in ovariectomized (OVX) rats. Five‐week‐old female Sprague‐Dawley rats were ovariectomized and fed a low‐calcium diet (0.009% Ca) for 5 weeks. The OVX rats were divided into three experimental groups: Control group (20% casein), MBP‐L group (19.9% casein, 0.1% MBP), and MBP‐H (19% casein, 1% MBP) of six animals. The rats were fed each experimental diet for 3 weeks. The bone breaking strength and energy of femur in the MBP‐H group were significantly higher than those in the control group. The bone breaking energy of femur in the MBP‐L group was also significantly higher than those in the control group. There were no differences in the amount of femoral calcium and phosphorus among the three groups, however, the amounts of femoral proline, hydroxyproline and hydroxylysine (typical amino acids of collagen) in the MBP groups were significantly higher than those in the control group. These data indicate that MBP in the whey protein increases the amount of the bone collagen and enhances the bone strength.     

Characterization of Fish Muscle Type I Collagen

Muscle Type I collagen of five teleosts was characterized with respect to its thermal stability and subunit composition. The muscle collagen exhibited a higher denaturation temperature, Td, in solution and a higher degree of proline hydroxylation, compared with skin Type I collagen of the respective species. Moreover, the Td values seemed to increase with the increasing upper limit of environmental temperature of fish habitats. The subunit composition also varied with fish species; an α1α2α3 heterotrimer existed in eel and common mackerel and an (α1)₂α2 heterotrimer in saury, while (α1)₂α2 and α1α2α3 heterotrimers appeared to be major and minor components, respectively, in chum salmon and carp.     

Microstrip Band Pass Filter of GHz Region Employing Aerosol-Deposited Alumina Thick Films

The miniaturized 10 GHz microstrip band-pass filter was successfully fabricated on the alumina thick films grown on Cu substrates at room temperature by aerosol deposition method and using the newly developed pattern electroplating procedure and electromagnetic analysis. The relative dielectric permittivity and loss tangent of the aerosol-deposited alumina thick films on Cu were 9.9 and 0.089, respectively. The resistivity of the electroplated Cu line was determined to be 2 × 10^{? 8} Ω m. The very good agreement was shown between results simulated using a 3-dimensional electromagnetic analysis and the actual measured data.     

随流而动 北京银河SOHO

北京银河sOHO是扎哈·哈迪德在中国的第二个项目,也是第一个商业项目。文章介绍了设计过程中对各方面的具体考量,提出一种新的营造柔性城市景观的建筑策略,从而应对巨型建筑和街区尺度的城市环境。     

Role of F-actin in Thermal Gelation of Fish Actomyosin

The thermal gelation processes of the myosin-natural actomyosin system were investigated to determine the role of F-actin in thermal gelation of actomyosin. The dynamic viscoelastic behavior during thermal gelation changed considerably depending on the (F-actin)/ (myosin) ratio. F-actin gave the viscosity to an actomyosin sol but did not affect the elasticity development occurring in the 30 - 46°C range. The decrease in storage modulus in the 46 - 53°C range was directly induced by the presence of F-actin. The gel of myosin alone showed the highest elasticity, while that of myosin containing a small amount of F-actin had the highest elastic modulus.