A Flux‐Modulating Synchronous Machine with Permanent Magnet Excitation

This paper presents a novel type of flux‐modulating synchronous machine (FMSM) in which permanent magnets (PMs) are embedded in the stator back‐iron. The rotor has neither windings nor PMs. A prototype machine with an outer‐rotor configuration was designed and manufactured to validate the operating principle of the FMSM. The characteristics in the motor mode of the prototype machine were also investigated with a vector control system. The results of the investigations show that, as in surface‐mounted PM motors, the torque of the FMSM is predominantly generated by the PM flux and can be controlled using the armature current.     

Kinetics of Initial Sintering with Grain Growth

Kinetic equations for initial sintering were obtained by combining the conventional kinetic equation with an empirical expression for grain growth in the initial stage. The equations describe the isothermal shrinkage of ZnO in O₂ at 80 torr and 800° to 950°C. The equation also successfully analyzed the sintering of powder compacts of Al₂O₃ studied by other workers.     

INFORMATION FILTERING FOR EMERGENCY MANAGEMENT

Information filtering is an intelligent function that selects the relevant messages and items of use or interest to the user from a large amount of incoming information. This function has become very important for the rapid development of network technology. This article focuses on information filtering for the management of emergency situations. We believe that special purpose-built "information filtering systems" should be developed to cope with the problem of information overload in emergency management. In this article, we first investigated features of information in emergent situations and then proposed an information filtering system for emergency management. The proposed system is composed of two parts: causal analysis and information classification. A prototype system has been developed and its effectiveness was evaluated by experiments.     

Stability Analysis for Grid‐Connected LCL‐Type Inverter with Digital Control

A grid‐connected inverter is indispensable for photovoltaic power generation and smart grid systems, and it must be designed for stable operation. The impedance method based on the Nyquist criterion is often utilized to analyze the stability of grid‐connected inverter systems. The impedance method is based on the eigenvalues of the product of the inverter output admittance and the line impedance matrices in the frequency domain. However, the frequency characteristics have so far been derived only for inverters with analog control systems. A new frequency analysis method for inverters with digital control systems is proposed in this paper. First, a stability analysis example for a three‐phase LCL‐type inverter controlled digitally is shown and the results are compared and validated with those by simulation using a Saber simulator. Finally, they are also compared and validated with experimental results digitally controlled by a DSP‐based system.     

ENZYMATIC CHARACTERISTICS OF TRYPSIN FROM PYLORIC CECA OF SPOTTED MACKEREL (SCOMBER AUSTRALASICUS)

Trypsin was purified from the pyloric ceca of spotted mackerel (Scomber australasicus) by gel filtration on Sephacryl S‐200 and Sephadex G‐50. The purification and yield were 20‐fold and 81%, respectively, as compared to those in the starting crude extract. Final enzyme preparation was nearly homogeneous in sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) and the molecular weight of the enzyme was estimated to be 24,000 Da by SDS–PAGE. The trypsin was stable at pH 5–11 for 30 min at 30C, and its maximal activity against N^α‐p‐tosyl‐L‐arginine methyl ester was pH 8.0. Trypsin was heat‐stable up to about 50C for 15 min at pH 8.0. Optimum temperature of the trypsin enzyme was 60C. The enzyme was stabilized by calcium ion. The purified trypsin was strongly inhibited by serine protease inhibitors such as N‐p‐tosyl‐L‐lysine chloromethyl ketone and soybean trypsin inhibitor, suggesting that it is a trypsin‐like serine protease. N‐Terminal amino acid sequence of spotted mackerel trypsin was IVGGYECTAHSQPHQVSLNS.     

A Study on Influence of Ramp Event of Aggregated Power Output of Photovoltaic Power Generation on Electric Power System Frequency

This paper examines the influence of aggregated power output fluctuation of photovoltaic power generation system (PVS) on the power system frequency focusing on ramp events of aggregated PVS power output. A numerical simulation model of economic load dispatching control (EDC) and load frequency control (LFC) is used together with a PVS power output forecasting model and a unit commitment (UC) scheduling model developed in our preceding study. As a result, in the case of ramp event with long duration and high ramp rate, the frequency violation occurs when the power output of controllable generators with high load‐following capability reaches to upper/lower limit even if the power output of low load‐following capability generators is still available. If the load dispatching scheme is tentatively changed from the conventional EDC using an equal incremental fuel cost rule to, for example, a dispatching policy based on the capacity without the consideration of fuel cost, the aggregated load‐following capability can be kept, avoiding the frequency violation.     

CHARACTERISTICS OF TWO TRYPSIN ISOZYMES FROM THE VISCERA OF JAPANESE ANCHOVY (ENGRAULIS JAPONICA)

Two isozymes of trypsin (TR‐I and TR‐II) were purified from the viscera of Japanese anchovy (Engraulis japonica) by gel filtration and anion‐exchange chromatography. Final enzyme preparations were nearly homogeneous in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), and the molecular weights of both enzymes were estimated to be 24,000 Da by SDS‐PAGE. The N‐terminal amino acid sequences of the TR‐I, IVGGYECQAHSQPHTVSLNS, and TR‐II, IVGGYECQPYSQPHQVSLDS, were found. Both TR‐I and TR‐II had maximal activities at around pH 8.0 and 60C for hydrolysis of Nα‐p‐tosyl‐L‐arginine methyl ester hydrochloride. The TR‐I and TR‐II were unstable at above 50C and below pH 5.0 and were stabilized by calcium ion.     

Integration of Incinerator Plants and Utilization of Forest Biomass on the Basis of FIT

Feed‐in tariff (FIT) has been enforced in order to promote the utilization of renewable energy since 2012 in Japan. In consideration of FIT, we propose an integration plan for incinerator plants (IPs) with highly efficient power generation for the whole area of a prefecture. The plan includes disposal of forest biomass using the reserve capacity of IPs. The model prefecture's population is set to 1,200,000 and the proportion of the forested area is set to 70% of the model area based on data for northeastern Japan. The present 16 IPs are integrated into three new IPs. A relay transportation (RT) facility for waste is located at a decommissioned IP, and the waste from the area is transported to the new IP. In order to calculate the RT costs, an approximation formula for the RT distance is estimated via the IPs integration study. The plan will realize about 37% cost reduction and 1.8‐fold CO₂ reduction including RT as compared to the plan to update the current IP situation. Forest biomass of 56,500 tons per year, which is about 43% of available forest biomass volume in the model prefecture, can be disposed of at new IPs. On the other hand, enough profit is not expected from the dedicated biomass power generation plant as a result of wood chip processing fees. The plan will help to develop local forestry.     

Evaluation of Grain-Growth Parameters

The complicated texture of a thin sheet of MgO and MgO-doped Al₂O₃ (∼15 pm) was statistically resolved into four typical grain geometries. Grain size distribution was related to the ratio of expressions describing the growth (or shrinkage) of individual grains and the growth of grains of average size R. Grain-growth data for MgO indicate that the mobility of a grain boundary is independent of R (parabolic-grain-growth behavior) but depends strongly on the ratio of individual grain size to average grain size. When mobility is proportional to 1/R, the time dependence of grain growth is <1/2.     

COMPARATIVE STUDY OF ENZYMATIC CHARACTERISTICS OF TRYPSINS FROM THE PYLORIC CECA OF YELLOW TAIL (SERIOLA QUINQUERADIATA) AND BROWN HAKELING (PHYSICULUS JAPONICUS)

Trypsins from the pyloric ceca of two fish species, yellow tail (Seriola quinqueradiata) and brown hakeling (Physiculus japonicus) were purified by a series of chromatographic separations. Purity increased 62‐ and 106‐fold with approximately 55 and 10% yield for yellow tail trypsin and brown hakeling trypsin, respectively. Final enzyme preparations were homogeneous in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), and the molecular weights of both enzymes were estimated to be 24 kDa by SDS‐PAGE. Yellow tail and brown hakeling trypsins had maximal activity at pH 8.0 for hydrolysis of N_α‐p‐tosyl‐L‐arginine methyl ester hydrochloride and was unstable at acidic pH. The optimum temperatures for yellow tail and brown hakeling trypsins were 60 and 50C, respectively. Yellow tail trypsin was stable up to 50C, whereas brown hakeling was stable up to 40C. Both trypsins were stabilized by calcium ions. The activities of both trypsins were strongly inhibited by soybean trypsin inhibitor and N_α‐p‐tosyl‐L‐lysine chloromethyl ketone hydrochloride, and were partially inhibited by ethylenediaminetetraacetic acid. The N‐terminal amino acid sequences of yellow tail trypsin and brown hakeling trypsin were determined as IVGGYECTPYSQPHQVSLNS and IVGGYECPKHSQPHQVSLNS, respectively.