Scenario study on FBR cycle deployment

A scenario study for fast breeder reactor (FBR) has been carried out. Some major scenarios have been induced from the viewpoints of economics, energy security, reduction of radioactive waste burden, and restriction of natural uranium resources “World natural uranium restriction scenario” among some scenarios has been analyzed in detail and introduced in this paper. The results indicate that FBR should be introduced by the middle of the 21st century at the latest in the world sharing energy supply with other energy resources.     

Hydroxypropylated Tapioca Starch Retards the Development of Insulin Resistance in KKAy Mice, a Type 2 Diabetes Model, Fed a High-Fat Diet

ABSTRACT:  The hypoglycemic and antidiabetic effect of hydroxypropyl tapioca starch (HPTS, degree of substitution = 0.180) was investigated in male KKAy mice. Mice were fed a purified high-fat (20%) diet without or with HPTS (5% or 10%) for 33 d. Gelatinized tapioca starch (TS) was used as a reference. Fasting blood glucose concentrations, days 14 and 28, were significantly lower in the 10% HPTS group compared with the reference. In an oral glucose tolerance test (OGTT), day 28, blood glucose concentrations in the 5% HPTS group, at 60, 90, and 120 min, and in the 10% HPTS group, at 30, 60, and 90 min after oral administration of glucose, were significantly lower compared with the reference. The area under the glucose curve (AUC) for glucose in both HPTS groups was significantly lower compared with the reference. Energy intake was significantly lower in the 10% HPTS group compared with the reference. At the end of the experiment, adiponectin concentrations were significantly higher in the 10% HPTS group compared with the reference. A homeostasis model assessment of insulin resistance (HOMA-IR) tended to be lower in the 10% HPTS group compared with the reference, whereas a quantitative insulin sensitivity check index (QUICKI) was significantly higher in both HPTS groups compared with the reference. These results show that HPTS retards the development of insulin resistance in KKAy mice fed a high-fat diet.     

Numerical Simulation of New Friction Welded Joints

In developing the new friction welding technology, the thermal elastic-plastic stress analysis by the finite element method was carried out to seek the suitable welding conditions such as the friction pressure, the friction speed and the upset pressure. The results obtained are as follows： Heat transfer to the specimens and the intermediate material during friction process was made clear; The operational conditions such as the rotation number of the intermediate material and the friction pressure to reach the liquidus in the interface could be estimated; Further, as the overhang length near the interface is well related to the joint efficiency, we tried to obtain the operational conditions by numerical analysis to acquire a certain length of the overhang length near the interface.     

Design progress of the ITER blanket remote handling equipment

The ITER blanket (BL) is composed of about 400 modules in the vacuum vessel (VV). The BL has to be maintained by remote handling means due to high radiation levels in the VV after D-T operation. The remote handling (RH) equipment for BL maintenance consists of articulated rail, supports, a rail-mounted vehicle, a telescopic arm, an end-effecter, tools and related systems such as transfer casks and umbilical system.Towards the construction, the BL RH equipment design has been improved and developed in more detail, based on the 2001 FDR design. The overview of design results is introduced in this paper. The design of rail deployment system of the BL RH has been updated to enable the rail connection in the transfer cask in order to minimize occupation space at storage area. For this purpose, design work has been performed for concept, sequence and typical simulation of BL replacement in the VV and rail deployment/storage of the RH equipment in the cask, including cask docking. In particular, the technical issues of the rail connection in the cask are (1) tight tolerance of a pin at a hinge, (2) limited space for the connection inside a cask and (3) tight positioning accuracy. This paper summarizes the idea to solve these issues and the results of the design work. The paper also introduces new cable handling equipment, rail support equipment and BL module transporter.     

Polymerization of methyl methacrylate with Ni(acac)2–methylaluminoxane catalyst

Polymerization of methyl methacrylate (MMA) with nickel(II) acetylacetonate [Ni(acac)₂] in combination with methylaluminoxane (MAO) was investigated. Ni(acac)₂ was found to be an effective catalyst for the polymerization of MMA. From a kinetic study of the polymerization of MMA with the Ni(acac)₂–MAO catalyst, the overall activation energy was estimated to be 15 kJmol⁻¹. The polymerization rate (R_p) was expressed as follows: R_p = k [MMA]^1.0[Ni(acac)₂–MAO]^0.6 (the MAO/Ni mole ratio was kept constant). The mechanism for the polymerization of vinyl monomers with the Ni(acac)₂–MAO catalyst is discussed. © 2000 Society of Chemical Industry     

Control and protection scheme of HVDC system with self‐commutated converter in system fault conditions

For extending self‐commutated converter application to future trunk power systems, it is important to develop a stable operation scheme as well as to realize substantial cost reduction through coordinated system and control design. Suppression controls of converter overcurrent and dc overvoltage in various system fault conditions are essential in order to ensure stable operation and cost reduction of HVDC systems with voltage source type self‐commutated converters. Converter control and protection schemes which include such suppression controls have been developed, employing CRIEPI's ac/dc Power System Simulator test and EMTP analysis. This paper first discusses the cause of converter overcurrent at ac system faults, considering the effect of PWM pulse number and converter control speed. Continued operation has been achieved by adding a new overcurrent suppression scheme to the converter control. In the case of a dc line grounding fault, the selection of the grounding circuit constant and the adoption of a high‐speed converter control practically ensure the reduction of dc overvoltage while suppressing converter overcurrent. The converter block and restart sequence after a dc fault, which is coordinated with dc circuit breaker operation, enables stable recovery of HVDC transmission as fast as the usual line‐commutated HVDC system. © 2000 Scripta Technica, Electr Eng Jpn, 132(2): 6–18, 2000     

Thermosyphon by refrigerant self‐excited oscillation

In a compact closed two‐phase thermosyphon, the boiling area is adjacent to the condensation area, and the condensation area is provided with innerfins different from conventional thermosyphons. We clarified that the combination of condensation and self‐excited oscillation convection resulted in a good heat release. To intensify this self‐excited oscillation, we made the innerfin unsymmetrical, and consequently an improvement was realized. © 2000 Scripta Technica, Heat Trans Asian Res, 29(6): 523–534, 2000     

Compact thermosyphon using refrigerant flow control

In a compact closed two-phase thermosyphon which consists of a multitube radiator and a refrigerant bath, it is observed that the heat radiation performance drops as the refrigerant bath becomes thin. We have found that this is due to vapor–liquid interaction and dryness in the upper side of the boiling area. We have also improved that heat radiation performance with a new refrigerant flow controller. ©1999 Scripta Technica, Heat Trans Asian Res, 28(8): 627–639, 1999     

Proteolytic degradation of myofibrillar components by carp cathepsin L

Carp cathepsin L, which is the best candidate to produce textural change in the arai-treated carp fillet, exhibited maximum hydrolytic activity for Z-Phe-Arg-MCA and soluble casein at pH 5·0–5·5. The proteolytic action of the enzyme was evaluated by complete degradation of various carp myofibrils at pH 5·0 over 30 min and by potent degradation of the same proteins at pH 5·5–6·0 over 20 h. All myofibrillar components were partially degraded by the enzyme at pH 6·5–7·0, but varying amounts of them remained undegraded after 20 h. These findings indicate that carp cathepsin L degrades not only carp myofibrillar components but also their resultant products between pH 5·0 and 7·0 and that it markedly acts on myosin heavy chain, α-actinin and troponin-T and -I. Carp cathepsin L likely contributes to postmortem muscle tenderisation of carp fillet over an extensive pH range during storage. © 1998 SCI.