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Kitami, Japan

Kitami Institute of Technology is a national university in Kitami, Hokkaido, Japan. Founded as the Kitami Junior College of Technology on 1 April 1960, it was chartered as a university on 1 April 1966. In 2004, it became part of the National University Corporation. Wikipedia.

Arai H.,Kitami Institute of Technology
Sub-Cellular Biochemistry | Year: 2014

Lipoproteins consist of lipids and apolipoproteins that have functional roles in lipid metabolism. It has been suggested that oxidation of lipoproteins by reactive oxygen species (ROS) may be involved in the inception of various dis- eases. In particular, the relationship between low-density lipoprotein (LDL) oxida- tion and atherosclerosis has been studied in great detail. The main target molecules of lipoprotein oxidation are polyunsaturated fatty acid residues of lipids and apolipoproteins. Extensive investigations have characterized oxidative modifica- tions of apolipoprotein B100 (apo B100) in LDL. Furthermore, modifications of apo B100 by oxidized lipids have been confirmed in oxidized LDL and atheroscle- rotic lesions using immunological techniques. In this chapter, characteristics and oxidation mechanisms of lipoproteins by ROS are described from in vitro and in vivo studies. Oxidative modifications of apo B100 by lipid hydroperoxides, major products of lipid peroxidation at the early stage, are principally reported. © Springer Science+Business Media Dordrecht 2014.

A new model for ductile fracture initiation is proposed based on a new concept, whereby ductile fracture initiation is caused by a jump in the wave velocity along the intersection line between two different stationary discontinuity bands characterized by the vanishing velocity of an acceleration wave. In the present paper, using the theory of ultrasonic wave velocity under plastic deformation proposed by the author, the micro-crack nucleation caused by a jump in the velocity along the intersection line between two discontinuity bands is verified theoretically by shock wave theory and analyzed numerically. Namely, diffuse necking, localized necking, and micro-crack nucleation diagrams, as well as the orientations of micro-cracks, are analyzed and discussed. Moreover, in order to consider the crystal orientation dependence of the ductile fracture progress, algorithms of the proposed criteria are incorporated into the finite element crystal plasticity model. The post-buckling process and collapse of FCC single crystal plates with different crystal orientations under uniaxial compression are then analyzed in detail and the dependence of the plastic buckling process on the crystal orientation is examined. © 2012 Elsevier Ltd. All rights reserved.

The solid oxide fuel cell triple combined cycle (SOFC-TCC) power generation system considered in this study is of rated power 1.4. MW, and it consists of SOFC (542. kW), a gas turbine (G/T, 550. kW), and a steam turbine (S/T, 308. kW). The relation of the frequency deviation based on the difference between supply and demand of an independent microgrid that interconnects the SOFC-TCC system and large-scale photovoltaics was investigated through numerical analysis. Because the stabilization of the load fluctuations of the SOFC and S/T required 1.8 to 2. h, control of load fluctuations occurring over periods of 2. h or less was mainly determined by the governor-free control of the G/T. Furthermore, the power characteristics (frequency) owing to cyclic fluctuations (changes occurring over a period of several minutes or less) to sustained fluctuations (changes occurring over a period exceeding 20. min) of a microgrid with large-scale photovoltaics was found to be strongly influenced by the magnitude of the inertial force of the G/T and S/T. From the analysis results, long-term supply-and-demand fluctuations, such as changes occurring seasonally and down to a period of 1. day, are mainly controlled by output adjustment of the SOFC and S/T, whereas the operation controlled by the setting of the governor-free control of the G/T and the inertial system of rotary machines is appropriate for short-term power fluctuations. © 2014 Elsevier Ltd.

Obara S.,Kitami Institute of Technology
International Journal of Hydrogen Energy | Year: 2010

A microgrid, with little environmental impact, is developed by introducing a combined SOFC (solid oxide fuel cell) and PEFC (proton exchange membrane fuel cell) system. Although the SOFC requires a higher operation temperature compared to the PEFC, the power generation efficiency of the SOFC is higher. However, if high temperature exhaust heat may be used effectively, a system with higher total power generation efficiency can be built. Therefore, this paper investigates the operation of a SOFC-PEFC combined system, with time shift operation of reformed gas, into a microgrid with 30 houses in Sapporo, Japan. The SOFC is designed to correspond to base load operation, and the exhaust heat of the SOFC is used for production of reformed gas. This reformed gas is used for the production of electricity for the PEFC, corresponding to fluctuation load of the next day. Accordingly, the reformed gas is used with a time shift operation. In this paper, the relation between operation method, power generation efficiency, and amount of heat storage of the SOFC-PEFC combined system to the difference in power load pattern was investigated. The average power generation efficiency of the system can be maintained at nearly 48% on a representative day in February (winter season) and August (summer season). © 2009 Professor T. Nejat Veziroglu.

Obara S.,Kitami Institute of Technology
International Journal of Hydrogen Energy | Year: 2010

The system proposed in this paper produces hydrogen by supplying photovoltaic power to a water electrolyzer and then supplying this gas to a fuel cell with a time shift. The objective of this system is to supply power to an individual house or apartment building with only green energy. However, the solar cell module installation area is large in the proposed system. Therefore, this paper considered installing a solar cell module with a plant shoot configuration. As a result of this modification, the power generation area of the proposed system is 33-52% smaller than that of a conventional flat solar cell module. From these results, it should be possible to introduce the proposed system into an individual house. © 2009 Professor T. Nejat Veziroglu.

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