微微型JT节流器（MMR）

微微型ＪＴ节流器（简称ＭＭＲ）发明于１９７８年，它以其高效性、结构简单、无噪声、无震动、低流率和快速预令等优点，被广泛地应用在军工及其它高科技领域中。微微型ＪＴ节流器是根据由微型逆流换热器理论发展来的设计理论，再结合光刻技术而制造出来的。它可以使用单工质或混合工质，能够满足较大的制冷温区。本文将回顾这种节流器的基本设计理论，制造工艺，基本性能及应用和发展前景。     

Measurement of radon concentration in water using the portable radon survey meter

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be <20 %, when the radon concentration in the mineral water was >20 Bq l(-1).     

A carrier phase control suitable for conducted EMI noise reduction in a multiple‐converter system

The conducted EMI noise flowing from power converters to an AC utility line is regulated by international commissions such as the International Electrotechnical Commission (IEC). Adherence to the IEC regulations requires that EMI filters should be used in power electronics equipment. This paper proposes a method for analyzing conducted EMI noise in multiple power converters connected to the same power line. In this method, the phase difference between subharmonic modulated carrier signals at each power converter is taken into account. The phase difference among the power converters determines the EMI noise level in a multiple converter system, as is evident from the analysis of the waveform of the common mode current. In addition, EMI noise suppression using carrier phase control is proposed. In order to reduce the size of the EMI filter effectively, the phase difference θ should be set to 360/nN°, where n is a high‐order harmonic component near 150 kHz and N is the number of power converters. Therefore, the conducted EMI noise can be reduced effectively with the help of the proposed phase control. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(3): 56–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21305     

Maximum potential of PV installation based on an energy system planning model considering a distribution voltage constraint

As the key solution for energy sustainability this decade, the growth of installing photovoltaic (PV) systems has dramatically increased. However, the high penetration of PV systems can cause a voltage variation problem in a distribution grid. This paper proposes a model for evaluating the maximum potential for installing PV systems in an urban area under a bus voltage constraint. A PV system is considered as an energy system alternative that replaces a conventional system. Regarding the power variation, it is necessary to add a parameter that is used to evaluate the variation of PV systems in terms of a standard deviation to the PV systems' electric load curve. The installations of PV and conventional systems are determined as share solutions for each load area along a distribution network. Total power loads and variations in each load area are input to a load flow calculation to obtain each bus voltage and confirm the voltage constraint. Finally, the total PV system installations over the whole network area is maximized. The alternative PV system with battery installation is introduced to validate the model evaluation when comparing with a typical PV system without a battery, which has larger power variation. Furthermore, adjusting the sending voltage at a substation to increase the PV installation is validated using the proposed model. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Preparation and Characterization of BaO–TeO2 Thin Films Obtained from Tellurium(VI) Alkoxide by a Sol–Gel Method

BaO–TeO₂ thin films were prepared from tellurium(VI) alkoxide by a sol–gel method and their structure was investigated by X-ray diffractometry, Fourier transform infrared spectrometry, and ¹²⁵Te static nuclear magnetic resonance. Their crystallization temperature ( T _c), optical transmittance, and dielectric constant were measured, and their refractive index was calculated from the transmission spectra. The results indicate that the BaO–TeO₂ thin films were composed of TeO₆ and TeO₄ units, and had a T _c of ∼520°C, refractive index of ∼1.79, dielectric constant of ∼20. These films had a T _c higher than the glass prepared by a melt-quench method, but their refractive index and dielectric constant were lower. These differences may be due to differences in their structural units.     

Enantioselective Hydrogenation of (E)-α-phenylcinnamic Acid over Cinchonidine-modified Pd Catalysts Supported on TiO2 and CeO2

The effects of the catalyst support, reaction temperature, and concentration of the modifier were examined to optimize supported Pd-catalysts and reaction conditions for the achievement of higher enantiomeric excess in the hydrogenation of (E)-α-phenylcinnamic acid. Over 90% of enantioselectivity was achieved using a cinchonidine-modified 40 wt% Pd/TiO₂ catalyst at 288 K.     

Continuous preparation of activated carbon supported zinc acetate catalyst and industrial synthesis of vinyl acetate from acetylene

A continuous manufacturing method of an activated carbon supported zinc acetate catalyst has been established. Based on the dipping of a crushed activated palm carbon into a zinc acetate aqueous solution, the catalyst is prepared for the synthesis of vinyl acetate from acetylene in an industrial fluidized reaction vessel. The relationship between the supported amount of zinc acetate and various factors has been studied. Based on these results, an empirical formula was developed. Using this formula, the continuous manufacturing apparatus was designed and constructed for the purpose of preparing the optimum supported fluidized catalyst. To minimize the activated carbon loss due to crushing and wearing, a vibrating conveyor system was employed. This continuous manufacturing process produced a uniform catalyst with an activated carbon feed rate of 0.25 m³ h^?1. Using this catalyst, a series of operational tests of the vinyl acetate synthesis was performed for investigating the optimum reaction conditions. These operational tests were carried out using an industrial fluidized reaction vessel of 3.28 m diameter and 50 tons day^?1 vinyl acetate production capacity. Based on these test results, the reaction rate constant and the deterioration rate constant were newly introduced, and the optimum operation conditions were then determined.