Prototype Experiments on a 1/32‐Scale Model Via‐Wheel Power Transfer Electric Vehicle

Electric vehicles (EVs) are expected to play a leading role in the changeover from fossil fuels to clean energy. However, EVs are currently not very popular, owing to their short cruising distance and long charging time. Wireless power transfer from the infrastructure to running EVs is expected to be the solution to these problems. Electric vehicle and electrified roadway (EVER) has been proposed as a wireless power transfer system for EVs while in motion. Via‐wheel power transfer (V‐WPT) is expected to be a wireless power transfer scheme for EVER. We designed and prototyped a 1:32 scale model of a V‐WPT system that consists of an RF inverter, an electrified roadway, a rectifier, and an EV with a dc motor. The output power of the prototype RF inverter was 5.9 W and the dc–RF conversion efficiency was 36.6%. The LC matching circuits for the V‐WPT were designed with two‐port conjugate matching because S₁₁ of the V‐WPT was intrinsically –0.06 dB. After matching, the S₁₁ value was reduced to –21.5 dB. The power transmission efficiency of the V‐WPT system was 75%. The RF–dc conversion efficiency of the rectifier was 62%. The total efficiency of the EVER system was 24.2%.     

影响啤酒酵母菌吸附铅离子条件的研究

采用啤酒酵母自制生物吸附剂用于吸附金属铅离子,考察了pH值、反应时间、酵母浓度及金属离子浓度对啤酒酵母吸附Pb2 的影响.单因素实验结果表明,当pH值为5.0、溶液初始Pb2 浓度为80 mg·L-1、啤酒酵母的浓度为1.0 g·L-1、反应时间为0.5 h时,吸附效果最佳.通过正交实验,确定初始Pb2 浓度为反应过程中的显著因素.     

啤酒酵母吸附重金属离子铬的研究

将啤酒酵母自制成生物吸附剂，用于吸附重金属离子铬，考察了啤酒酵母吸附Cr^3＋过程中的影响因素，即pH值、初始Cr^3＋质量浓度、吸附时间、菌体浓度及酸碱预处理方法等因素。结果表 明，啤酒酵母对Cr^3＋的吸附量随pH值的增加而增大，吸附的最佳pH值范围是4～7，当pH7时达到吸附最大值；随着初始Cr^3＋质量浓度增加，吸附量有所提高，当溶液初始Cr^3＋质量浓度为80mg／L吸附效果最佳；最佳吸附时间为1h；菌体的最佳浓度为50mg／L；及啤酒酵母经碱处理后吸附量增大：正交试验确定反应时间为反应过程的显著因素，确定啤酒酵母对Cr^3＋的吸附过程遵循Langmuir方程。     

CUMULATIVE FATIGUE DAMAGE UNDER RANDOM LOADS

Abstract This paper presents a simple algorithm of hysteresis loop counting to make on-line data processing much easier. It involves a modification of the range pair counting method and the rain flow method and yields practically the same result as these methods. In addition, the applicability of the present method to cumulative damage estimation is examined in experiments on fatigue crack growth rates under stationary random loads and low cycle fatigue lives under stationary random loads together with non-stationary random loads such as seismically excited loads.     

Heat and Moisture Transfer in Composite Food—Theoretical Analysis of Influence of Surface Conductance and Component Arrangement

Heat and moisture transfer in composite bodies undergoing drying was simulated using a previously developed mathematical model which included the chemical potential of moisture as a mass transfer potential. Composite bodies included layered cylinders and concentric spheres consisting of a starch granule hydrate (H) and a hydrate of starch granules-sucrose 3:l mixture (S). The influence of the following factors on heat and moisture transfer was examined: convective surface mass transfer conductance, initial moisture, and component arrangement. The three factors significantly influenced moisture transfer white they had slight influence on heat transfer. Overall drying rate of each composite body was infhrenced interactively by moisture fluxes, which were caused by a surrounding drying medium and by a mass transfer potential difference across the interface of H and S.     

Grain size and texture changes of magnesium alloy AZ31 during multi-directional forging

Grain size and texture changes of magnesium alloy AZ31 were studied in multidirectional forging(MDF) under decreasing temperature conditions.MDF was carried out up to large cumulative strains of 4.8 with changing the loading direction during decrease in temperature from pass to pass.MDF can accelerate the uniform development of fine-grained structures and increase the plastic workability at low temperatures.As a result,the MDFed alloy shows excellent higher strength as well as moderate ductility at room ...     

A Simple Method to Determine Synchronous Machine Quantities Using Frequency Characteristics of Operational Impedances

This paper presents a simple method for determining synchronous machine quantities: d‐ and q‐axes time constants and reactances. This method determines them only by drawing additional lines in the frequency characteristics of operational impedances. A new systematic drawing strategy for determining transient/subtransient open‐circuit time constants and the d‐axis transient reactance is proposed. The frequency characteristics of operational impedances are obtained by the standstill dc test using a small dc power supply. Since the rotational test becomes unnecessary, the proposed method is suitable for tests in a factory. The validity of the proposed method was demonstrated with a numerical calculation example on a large‐capacity machine (800 MVA, 25 kV, two poles, 60 Hz) and an implementation test on a small‐capacity machine (10 kVA, 200 V, 31.9 A, four poles, 50 Hz).     

MULTICAST ROUTING SCHEMES IN ATM

In this study, we investigate the problem of accommodating multicast traffic in ATM networks, with emphasis on the virtual path (VP) environment. We propose a network structure called “virtual copy network” that is suitable for multicast communication and connection setup scheme, taking into account the VP environment. With our technique, we can expect statistical multiplexing gain in accommodating multiple multicast traffic streams over a VP. Also, we propose two multicast routing algorithms (the CNR-LH algorithm and the improved CNR-LH algorithm) for an ATM network environment. In these algorithms, in addition to determining an adequate route, the exact corresponding VPs on the route are also obtained. We examine the efficiency of the algorithms by demonstrating their basic characteristics using computer simulations.