PV Power Output Control Improving Transient Stability of Power System with a Large Penetration of PV

Because of energy and environmental policies in the last decade, a lot of photovoltaic (PV) generations have been installed into power systems in Japan in recent years. In this situation, it is of great concern that disconnection of PV due to voltage drop caused by a system fault has a critical impact on power system stability. To avoid its disconnection, Fault Ride Through (FRT) requirement is applied for PVs. In this paper, PV power output control which improves transient stability of the power system with a huge amount of PVs is proposed and its effectiveness is confirmed by the numerical simulations.     

Multiphase surfactant-assisted reaction-separation system in a microchannel reactor

The Lewis acid-catalyzed addition of trimethylsilyl cyanide to p-chlorobenzaldehyde in a microchannel reactor was investigated. The microchannel was integrated to promote both reaction and separation of the biphase system. FeF₃ and Cu(triflate)₂ were used as water-stable Lewis acid catalysts. Sodium dodecyl sulfate was incorporated in the organic-aqueous system to enhance the reactivity and to manipulate the multiphase flow inside the microchannel. It was found that the dynamics and the kinetics of the multiphase reaction were affected by the new micellar system. Parallel multiphase flow inside the microchannel was obtained, allowing for continuous and acceptable phase separation. Enhanced selectivity was achieved by operating at lower conversion values.     

Improved water resistance in edible zein films and composites for biodegradable food packaging

Zein, corn prolamine, was dissolved in several organic solvents to make films and their properties were examined. Ethanol with 20% water and acetone with 30% water were found to dissolve zein well and transform it into a transparent flexible film after moderate drying. Both films showed similar breaking strength to that of commercial thin film of polyvinylidene chloride for food use and were digested with proteases. Only the film prepared from acetone solution showed a relatively low water permeability. This water permeation was found to depend strongly on the rate of diffusion. 1,2-Epoxy-3-chloropropane (ECP) was added into the acetone solution to cross-link the zein molecules for the purpose of improving the breaking strength and water-resistant properties of the film. Alpha-chymotrypsin was found to digest the film even after the modification with ECP. However, this cross-linking resulted in little improvement in the water-resistant properties of the film and also reduced its flexibility.     

A resource allocation problem on timed marked graphs: a decomposition approach

In complex man-made environments discrete event dynamic systems are frequently encountered, and a timed marked graph is widely accepted as a convenient tool to describe systems of this kind. We consider trade-offs of cost and performance on such a system. First we formulate an optimization problem and transform it into a mixed integer linear programming problem. To improve computational efficiency, we decompose the problem into two phases. In phase one we determine the optimal number of each resource to be adopted in the system, and in phase two we optimize the distribution of these resources over the system. Phase one is solved very quickly and approximately by the dominance relaxation through a binary search procedure. This also gives the estimate of error bounds. An illustrative example shows an application to a jobshop optimization problem, and numerical experiments are carried out for some sample problems.     

Si nanowire FET and its modeling

Because of its ability to effectively suppress off-leakage current with its gate-around conffguration, the Si nanowire FET is considered to be the ultimate structure for ultra-small CMOS devices to the extent that the devices would be approaching their downsized limits. Recently, several experimental studies of Si nanowire FETs with on-currents much larger than those of planar MOSFETs have been published. Consequently, Si nanowire FETs are now gaining significant attention as the most promising candidate fo...     

Prototype Evaluation of Grid‐Connected Bidirectional Power Conversion System for Storage Battery Systems with Bidirectional Switch Circuit Topology

In recent years, various storage battery systems, such as home battery system, V2H/V2G system, and UPS system, have spread rapidly all over the world. We propose a new power conversion system for use in the previously‐stated storage battery systems. This paper describes operation analysis of this system for bi‐directional power conversion with fundamental grid‐interconnection. Good output follow‐up controllability characteristics of the proposed system are shown through experimental results.     

LIPASE ACTIVITY AND STABILITY IN SUPERCRITICAL CARBON DIOXIDE

The use of a supercritical fluid as a medium for enzymatic reaction was investigated with respect to its application and reaction mechanism. Lipase could catalyze the reaction of hydrolysis and interes-terification in supercritical carbon dioxide at 35°C and 137 bar. There was no difference in the time course of interesterification between the untreated lipase and the lipase exposed to supercritical carbon dioxide indicating that the enzyme was not severely damaged.     

IMPEDANCE CALCULATION OF SOLID SALIENT-POLE MACHINE AT ASYNCHRONOUS OPERATION

ABSTRACT

This paper calculates the impedance of salient-pole machine, using the finite element technique, also the induction torque calculated for asynchronous operation. The flux distribution and Poynting vector are also calculated by finite element method (FEM).

The impedance calculation formula of the solid pole which has nonlinear magnetic characteristics is obtained analytically by using the solution of the two dimensional problem taking into consideration the magnetic saturation of the solid rotor induction motor     

基于阻抗辨识器的摇操作工程机器人主从控制

提出一种基于阻抗辨识器的摇操作工程机器人主从控制方法.首先建立负载阻抗辨识器模型，依此模型，通过在线提取负载力和监测负载形变，获得负载阻抗，以此改变从动手机构的控制量。实验证明，基于该方法提出的变增益控制和位置-力复合控制的主从控制结构及算法，均可使操作者对负载形变及刚度的感觉得到明显改善.     

The Effects of Fluorescent Substances on the Photofading of Colours

The addition of fluorescent brightening agents of the pyrazoline-type accelerates the photofading of triphenylmethane dyes, while the dyes quench the photoreactions of the fluorescent brightening agents. The accelerations were most marked when irradiation was carried out in the maximum fluorescence excitation region of the fluorescent brightening agents. Stern-Volmer quenching studies and chromatographic analyses of the photoproducts revealed that the accelerated photofading reactions involved triplet sensitizations of the dyes by the fluorescent brightening agents.