Re-evaluation of Radiation-Energy Transfer to an Extraction Solvent in a Minor-Actinide-Separation Process Based on Consideration of Radiation Permeability

ABSTRACT

Absorbed-dose estimation is essential for evaluation of the radiation tolerance of minor-actinide-separation processes. We propose a dose-evaluation method based on radiation permeability, with comparisons of heterogeneous structures seen in the solvent-extraction process, such as emulsions forming in the mixture of the organic and aqueous phases. A demonstration of radiation-energy-transfer simulation is performed with a focus on the minor-actinide-recovery process from high-level liquid waste with the aid of the Monte Carlo radiation-transport code PHITS. The simulation results indicate that the dose absorbed by the extraction solvent from alpha radiation depends upon the emulsion structure, and that from beta and gamma radiation depends upon the mixer-settler-apparatus size. Non-negligible contributions of well-permeable gamma rays were indicated in terms of the plant operation of the minor-actinide-separation process.     

Contribution of metal vapor mass at periphery part of pulsed arc to electromagnetic force in weld pool

The arc welding has been used in various welding methods because it is inexpensive and high in strength after welding. However, it is a problem that accidents such as collapse of the bridge occur because of the welding defects. The welding of low cost and high productivity is required without the welding defects. The pulsed TIG welding is inexpensive and capable of high‐quality welding. The electromagnetic force contributing to penetration changes because the transient response of arc temperature and iron vapor generated from anode occurs. However, the analysis of pulsed TIG welding with metal vapor has been elucidated only metal vapor concentration near anode with transient phenomenon and heat flux. Thus, the theoretical elucidation of penetration depth with control factor has not been researched. In this paper, the contribution of metal vapor mass at the periphery part of pulsed arc to the electromagnetic force in the weld pool is elucidated. As a result, the iron vapor mass at periphery part decreased with increasing the frequency. The iron vapor was stagnated at axial center within one cycle. The electromagnetic force to the penetration depth direction in weld pool increased at axial center. Therefore, the metal vapor mass at periphery part plays an important role for the electromagnetic force increment at axial center.     

Effect of pitting corrosion on strength of web plates subjected to patch loading

Pitting corrosion is typical corrosion observed on coated hold frames in way of cargo holds of bulk carriers, which exclusively carry coal and iron ore. Extensive survey on the effect of pitting corrosion on structural strength under a wide variety of loading conditions is necessary to clarify the relationship between pitting intensity and residual strength in detail. In the present study, a series of tests has been conducted on structural models which consist of web, shell and face plates to investigate the effect of pitting corrosion on strength of web plates subjected to patch loading. In these tests, artificial pitting was made on the web plates and two equal concentrated loads have been applied vertically at the one third points of simply supported models. It was found that web crippling behavior is strongly affected by the pit distribution on the web plates. According to the FE-analyses following the experiment, ultimate strength of the web plates with pitting under patch loading is a little smaller than or almost the same as that of the web plates with uniform corrosion in terms of average thickness loss.     

Recording of bridge damage areas by 3D integration of multiple images and reduction of the variability in detected results

Machine learning models have been developed to perform damage detection using images to improve bridge inspection efficiency. However, in damage detection using images alone, the 3D coordinates of the damage cannot be recorded. Furthermore, the accuracy of the detection depends on the quality of the images. This paper proposes a method to integrate and record the damage detected from multiple images into a 3D model using deep learning to detect the damage from bridge images and structure from motion to identify the shooting position. The proposed method reduces the variability of the detection results between images and can assess the scale of damage or, conversely, where there is no damage and the extent of inspection omissions. The proposed method has been applied to a real bridge, and it has been shown that the actual damage locations can be recorded as a 3D model.     

Construction of Cellulose Binding Domain Fusion FMN-Dependent NADH-Azoreductase and Glucose 1-Dehydrogenase for the Development of Flow Injection Analysis with Fusion Enzymes Immobilized on Cellulose

The cellulose binding domain (CBD) of cellulosome-integrating protein A from Clostridium thermocellum NBRC 103400 was genetically fused to FMN-dependent NADH-azoreductase (AZR) and glucose 1-dehydrogenase (GDH) from Bacillus subtilis. The fusion enzymes, AZR-CBD and CBD-GDH, were expressed in Escherichia coli Rosetta-gami B (DE3). The enzymes were purified from cell-free extracts, and the specific activity of AZR-CBD was 15.1 U/mg and that of CBD-GDH was 22.6 U/mg. AZR-CBD and CBD-GDH bound strongly to 0.5 % swollen cellulose at approximately 95 and 98 % of the initial protein amounts, respectively. After immobilization onto the swollen cellulose, AZR-CBD and CBD-GDH retained their catalytic activity. Both enzymes bound weakly to 0.5 % microcrystalline cellulose, but the addition of a high concentration of microcrystalline cellulose (10 %) improved the binding rate of both enzymes. A reactor for flow injection analysis was filled with microcrystalline cellulose-immobilized AZR-CBD and CBD-GDH. This flow injection analysis system was successfully applied for the determination of glucose, and a linear calibration curve was observed in the range of approximately 0.16–2.5 mM glucose, with a correlation coefficient, r, of 0.998.     

Dynamic Power Integrity Control of ATE for Eliminating Overkills and Underkills in Device Testing

This paper proposes a power integrity control technique for dynamically controlling power supply voltage fluctuations for a device under test (DUT), and demonstrates its effectiveness for eliminating the overkills/underkills due to the difference of power supply impedance between an automatic test equipment (ATE) and a practical operating environment of the DUT. The proposed method injects compensation currents into the power supply nodes on the ATE system in a feed-forward manner such that the ATE power supply waveform matches with the one on the customer’s operating environment of the DUT. A method for calculating the compensation current is also described. Experimental results show that the proposed method can emulate the power supply voltage waveform under a customer’s operating condition and eliminate 95 % of overkills/underkills in the maximum operating frequency testing with 105 real silicon devices. Limitations and applications of the proposed method are also discussed.     

Silicon based on-chip antenna using an LC resonator for near-field RF systems

This paper presents the silicon based on-chip antenna using a LC resonator. The proposed antenna consists of a stacked capacitor and a spiral inductor on silicon substrate. The spiral inductor structure without underpass was proposed for improvement the performance of the silicon based-antenna. The resonant frequency of the fabricated antenna was measured as 465 MHz. Its return loss was 23.4 dB at resonant frequency. The antenna has a gain of ?35.75 dBi due to small size and silicon substrate. However, the fabricated antenna has good performance in the near-field.     

Side-chain type benzoxazine-functional cellulose via click chemistry

A side-chain type benzoxazine-functional cellulose has been developed using click chemistry via the reaction of ethynyl-monofunctional benzoxazine monomer and azide-functional cellulose. The synthesis, crosslinking, and thermal properties of the benzoxazine-functional cellulose are studied by NMR, FTIR, DSC, and TGA. The crosslinking reaction of the benzoxazine side-chain unusually takes place at low-temperatures in comparison to an ordinary benzoxazine resins. Upon crosslinking, the polymer shows high char yield of 40%, which is a marked improvement from a mere 4% of the unfunctionalized cellulose. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012