Effect of platinum on the critical current density of fluorine-doped YBa2Cu3Ox superconductors

The critical current density, Jc, in fluorine-doped YBa2Cu3Ox bulk superconductors has been measured at several temperatures. The measured Jc value is 108 A m-2 at 77 K and 0.5 T. A sample with a larger critical current density can be produced by the addition of a small amount of platinum during the sintering process. The added platinum has the effect of evenly distributing Y2BaCuO5 particles and voids in the matrix in comparison with the undoped sample. These distributions of Y2BaCuO5 particles and voids are reflected in an increase in the critical current density. However, these distributions are not directly related to the observed peak effect in the critical current density. If the fluorine-doped YBa2Cu3Ox superconductor consists of the matrix and a phase with a Ginzburg–Landau parameter, that is slightly different from that of the matrix, then the occurrence of the peak effect can be explained.     

日本水坝的安全管理和地震安全评价

日本是一个地震多发的国家,而特殊的地形又决定了水坝在其经济社会发展中具有重要的地位,因此水坝的安全管理和地震安全评价就成为一个至关重要的方面.     

SENSORY AND INSTRUMENTAL TEXTURE ANALYSIS OF CASSAVA (MANIHOT ESCULENTA, CRANTZ) ROOTS

Two cassava varieties, at three harvesting ages, 6, 12 and 24 months, were analyzed for sensory flavor and texture development. Maximum shear force, Texture Profile Analysis (TPA) and water absorption during cooking were determined at various sampling times. Changes during cooking were described by pseudo‐zero order models for water absorption, flavor and texture development for the fast cooking samples. The 24‐month‐old roots had higher variability and never reached optimum texture or flavor development. Significant pseudo first order models could represent hardness, cohesiveness and chewiness of the TPA, while springiness and adhesiveness varied in a non‐linear fashion. Maximum shear force was 111 N for raw samples and 8.1 N for samples that cooked in less than 25 min. Samples that required longer cook time had on the average a maximum shear force of 19 N.     

Vacuum Insulation and Achievement of 980 keV, 185 A/m~2 H-Ion Beam Acceleration at JAEA for the ITER Neutral Beam Injector

Vacuum insulation of 1 MV is a common issue for the HV bushing and the accel- erator for the ITER neutral beam injector (NBI). The HV bushing as an insulating feedthrough has a five-stage structure and each stage consists of double-layered insulators. To sustain 1 MV in vacuum, reduction of electric field at several triple points existing around the double-layered insulators is a critical issue. To reduce electric field simultaneously at these points, three types of stress ring have been developed. In a voltage holding test of a full-scale mockup equipped with these stress rings, 120% of rated voltage was sustained and the voltage holding capability required in ITER was verified. In the MeV accelerator, whose target is the acceleration of a H ion beam of 1 MeV, 200 A/m 2 , the gap between the grid support was extended to suppress breakdowns triggered by electric field concentration at the edge and corner of the grid support. This modi- fication improved the voltage holding capability in vacuum, and the MeV accelerator succeeded in sustaining 1 MV stably. Furthermore, it appeared that the H ions beam was deflected and a part of the beam was intercepted at the acceleration grid. This causes high heat load on the grids and breakdowns during beam acceleration. To suppress the direct interception, a new grid was designed with proper aperture displacement based on a three dimensional beam trajectory analysis. As a result, 980 keV, 185 A/m 2 H ion beam acceleration has been demonstrated, which is close to the ITER requirement.     

Non-inductive start up of QUEST plasma by RF power

Both start-up and sustainment of plasma were successfully achieved by fully non-inductive current drive using microwave with a frequency of 8.2 GHz. Plasmas current of 15 kA was implemented for 1 s. Magnetic surface reconstruction exhibited a plasma shape with an aspect ratio of below 1.5. The plasma current was dependent significantly on the launchen microwave power and vertical magnetic field, whiile not affected by the mode of launched wave and the toroidal refractive index. Hard X-ray (HXR) emitted from energetic electrons accelerated by the microwave was observed, and the discharge with a plasma current over 4 kA followed the same trend as the number of photons of 10 to 12 keV. This suggests that the plasma current may be driven by energetic electrons. Based on the experimental conditions, alternative explanations of how the plasma current could be driven are discussed.     

日本木作技术书《镰仓造营名目》中的禅宗样斗栱构成与设计方法(其一):与《营造法式》的比较研究

本文以 13—19 世纪镰仓建长寺木匠世家河内家族流传下来的建筑技术书籍《镰仓造营名目》为研究对象， 分析了其中记述的禅宗样斗栱的构成与设计方法，继而将其与中国建筑技术书《营造法式》进行了比较研究。最终确认了中日均有以栱木尺寸为基准单位进行设计的做法， 而使用等距控制线以及使用椽子尺寸为基本尺寸单位等做法为日本改进之后的日本化技法。     

ε-(γ-Glutamyl)lysine Crosslink Distribution in Foods as Determined by Improved Method

Quantitative analysis of ε-(γ-glutamyl)lysine crosslink in 127 foods was achieved with a, preliminary separation by reverse phase-HPLC before o-phthalaldehyde derivatization to remove interfering peaks. ε-(γ-Glutamyl)lysine was detected in 96 foods and its contents ranged from 0.2 to 135 μmol/lOOg protein. High levels were found in fish paste products, processed fish, shellfish, meats and soybeans, and raw poultry organs. For fish and meats, the level of ε-(γ-glutamyl)lysine in processed foods and fish paste was relatively higher than that in raw materials. The improved procedure could be applied for screening materials with transglutaminase activities.     

Fast Electromagnetic Transient Simulations of Power Systems Utilizing Single‐Phase Phasor‐Based Modeling of Remote Systems

Electromagnetic transient (EMT) simulations of relatively large power systems have become quite common, for instance, in the case where simulations of HVDC converters are carried out with large ac power systems connected to the converters. Thus, the increase in computation time is a serious concern. To reduce computation time, this paper proposes a method to reduce computational demand of a remote power system which is located far from the source of a transient event to be simulated. In the proposed method, the remote power system, which is supposed to be represented by a three‐phase EMT‐based model, is reduced to a single‐phase phasor‐based model, and the size of the circuit to be simulated is thus reduced and the dynamics calculations of inductors and capacitors included in the remote power system are neglected. The calculation algorithm of generator models included in the remote power system is also simplified. The proposed method has been applied to EMT simulations of the WEST 10 benchmark power system prepared by the IEEJ, and it has been shown that the computation time is remarkably reduced without significant loss of accuracy if the portion assumed to be the remote power system is sufficiently far from the source of a transient event.     

A Development of Rom-Exercise Machine Using Linkages(Design of Leg Mechanism by Walking Simulation)

In this study, the design of an automatic ROM-Exercise machine that is constructed witha planar multililnk mechamsm consisting of only revolute pairs is investigated. Namely, equations thatdetermine the minimum moving spaces and relative positions of link required to construct the legmechanism are formulated with consideration of transform functions. For the leg mechanism that isconstructed with a planar eleven-link mechanism, arrangements of each link and optimum linkprofiles avoided mutual interferences among moving links are determined wb consideration of therelative locations of each link in the same plane during a cycle of motion of the mechanism. Based onthe above analytical results, an automatic ROM-Exercise machine that performs within a minimum moving spaces is proposed as a prachcal example. ms study is carried out as part of the students'computcr education to the graduation thesis, in order to improve their creativity and machine designtechnology skills in coniunction with educational advantages. Significam educational results areobtained by using the design techniques mentioned above.     

Sodium Caseinate and Skim Milk Gels Formed by Incubation with Microbial Transglutaminase

Several suspensions and emulsions containing commercial sodium caseinate or skim milk were gelatinized by Ca²⁺-independent microbial transglutaminase treatment. The characteristics of the gels were largely affected by the enzyme concentrations employed. For caseinate gels generally the higher enzyme concentration gave steep decreases in breaking strength, strain and cohesiveness of the gels. The creep tests on emulsified gels prepared to two different enzyme concentrations showed that the gel made with a higher enzyme concentration was the more viscoelastic. For skim milk gels, the enzyme treatment in higher concentration caused substantial increase of the breaking and hardness while the strain and cohesiveness had little or no changes.