Dynamic Characteristics Analysis of Two‐DOF Oscillatory Actuator and Experimental Verification of Prototype

Recently, linear oscillatory actuators have been used in a wide range of applications. In particular, small linear oscillatory actuators are expected to be used in haptic devices by being extended to provide multi‐degree‐of‐freedom motion with arbitrary acceleration. In this paper, we propose a compact two‐DOF oscillatory actuator that can move in various directions on a plane. The static and dynamic characteristics of the actuator are determined by the 3D finite element method. The effectiveness of this method is shown through a comparison of the measured results with the experimental results from a prototype. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 58–65, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22312     

Development of multianode photomultiplier tube

We have developed a multianode photomultiplier tube (MAPMT) which has a sensitive cathode diameter of 36 mm and an anode with 88 segments. The position sensitivity of the tube was studied by using light from a LED and scintillation light from a scintillation-fiber bundle. We observed particle tracks for the first time by using a single photomultiplier tube.     

Large-Scale Shake Table Experiment and Numerical Simulation on the Nonlinear Behavior of Pile-Groups Subjected to Large-Scale Earthquakes

This paper describes the results of large-scale shake-table experiments involving a 3×3 pile-group. The pile-group was embedded in dry sand and subjected to sinusoidal waves and an earthquake motion recorded from the 1995 Hyogo-ken Nanbu (Kobe) earthquake. The load transfer between soil and pile was derived and the group effect was captured. Numerical simulations were also performed using a Beam-on-Nonlinear-Winkler-Foundation approach with a new hysteretic p-y curve. A comparison of the experimental and numerical results revealed that the numerical simulation is capable of accounting for the soil-pile interaction observed in the experiment.     

Millimeter-Wave Radiometer for the Measurement of Stratospheric ClO Using a Superconductive (SIS) Receiver Installed in the Southern Hemisphere

A new sensitive radiometer for atmospheric minor constituents has been developed by Nagoya University and the National Institute for Environmental Studies (NIES). The instrument equipped low-noise superconducting (SIS) mixer with a system noise temperature of ≈200K (SSB) at 204GHz. The SIS mixer is operated in a single side band mode with a side band ratio grater than 10dB by adjusting the two tunable backshorts of the mixer. Since any additional SSB filters are not necessary, we can simplify the quasi-optical system and reduce the standing waves which makes difficult to achieve a flat spectral baseline. We installed the observation system at Las Campanas Observatory, Chile in December 1999, and started the test observation from 2000 October. We have detected significant ClO emission at 204.3 GHz with an actual observation time of only 4 hours. This is the first detection of the ClO at 40km altitude from the mid-latitude region of the southern hemisphere. The Nagoya-NIES system has enabled continuous monitoring of ClO in the stratosphere with a time resolution of 4 or 5 hours.     

基于 EVD 的一种高速公路路基压实度快速检测方法研究

路基的压实质量直接决定路基承载能力和抗变形能力,也同时影响道路的服务水平和使用寿命。传统的路基压实度采用环刀法、灌砂法、灌水法等,其操作复杂、投入人力多、测试时间长。本文将便携式动态变形模量测试仪(LFGpro)测得的动态变形模量(EVD)与压实度(K)之间建立相关关系,从而快速、高效的得到路基的压实度。本文分别建立了黄土(低液限粉土ML)、红砂岩(黏土质砂)、红泥岩(高液限黏土CH)路基EVD与K之间的相关关系,相关性良好。     

桥梁铰缝加固用环氧树脂力学性能的影响因素分析

研究了时间、配比和温度对桥梁铰缝加固用环氧树脂力学性能的影响。试验结果表明,随着固化温度的升高,胶体固化时间减少,树脂自身强度增加,抗弯、抗压和劈裂强度增大,断裂伸长率降低,胶体发生脆断所需拉伸力减小;不同温度下,抗弯、抗压和劈裂抗拉强度随时间的增长,基本呈现上升趋势。升高温度有利于树脂的早期粘结强度,但是后期可能存在老化,使得粘结能力下降;固化剂的含量在一定范围内增加,树脂固化时间缩短,但是对最终粘结强度影响不大。     

Bloom Formation on Poorly-Tempered Chocolate and Effects of Seed Addition

Bloom on chocolate with different levels of cocoa butter seed addition was investigated. When insufficient cocoa butter seed crystals were added to give proper temper, the chocolate developed bloom as dark brown spheres in lighter color areas, similar to that seen in bloom on untempered chocolate. These dark colored spheres overlapped and the lighter color areas disappeared with increasing seed amount added. The relationship between seed amount and lighter color area (bloom), as quantified by image analysis, showed that over 270 ppm seeds (fat basis) were needed to accomplish good tempering. The cocoa butter crystallization behavior with various amounts of seed was observed by light microscopy. Too few seeds caused sparse β crystallization and massive β′ crystallization, which explains the appearance of poorly tempered chocolate bloom. As seed amount increased, β crystallization of cocoa butter took less time to reach the upper level of solid fat content and the size became smaller. In addition, DSC analysis was carried out to study crystallization and melting behavior of cocoa butter with different seed amounts. Higher levels of added seeds resulted in greater amounts of β crystal formation and the crystallization temperature increased, which meant crystallization occurred earlier. These results showed that the mechanism of bloom formation on poorly tempered chocolate (insufficient seeds) is due to sufficient time and space for phase (particles and fat) separation as the stable polymorphs grow.     

超临界流体技术在苎麻织物中的应用研究

对影响超临界CO2流体处理苎麻纤维的因素，如温度、压力、时间以及助溶剂进行正交试验，对处理后的苎麻纤维的含杂情况、微结构、机械物理性能和热稳定性等性质作了测试分析。结果表明，超临界CO2流体处理苎麻织物的最佳工艺条件为：工作温度120℃、压力25MPa、时间40min、助溶剂0．1％。该处理可改善苎麻纤维的性能，提高其膨胀性，有利于后续加工，并为其进一步改性打下基础。     

Two acyl-CoA dehydrogenases of Acinetobacter sp. strain M-1 that uses very long-chain n-alkanes

Two genes encoding acyl-CoA dehydrogenases, acdA and acdB, arranged in tandem, were found in the chromosomal DNA of Acinetobacter sp. strain M-1. AcdA was purified from the parental strain and AcdB was purified from an Escherichia coli strain expressing the cloned gene. The substrate specificities of the two enzymes suggest that AcdA is a medium-chain acyl-CoA dehydrogenase and that AcdB is a long-chain acyl-CoA dehydrogenase. Characterization of n-alkane metabolism in Acinetobacter sp. strain M-1 has revealed parallel pathways as well as enzymes with overlapping specificities in a single pathway. The two acyl-CoA dehydrogenases described here provide another example of the physiological complexity underlying n-alkane utilization.