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Corona‐discharge air ionizers have been used to neutralize static electricity on electronic devices during manufacturing and/or inspection processes. The neutralization performance, that is, the neutralizing current density (JW) and the electric field (EW), in work area depends on the operating conditions. Methods for estimating the neutralization performance are required to check them without stopping the production lines. In this paper, we propose an estimation method using an equivalent circuit simulation called the Simulation Program with Integrated Circuit Emphasis (SPICE) for estimating the behavior of positive and negative ions in the generation, transportation, and work areas. In the simulation, the ion generation characteristics are simulated by diodes and resistors. The transportation and accumulation of the ions are simulated by resistors and capacitors, respectively. The annihilation of ions by recombination is simulated by a circuit composed of capacitors and resistors. The simulation results are in good agreement with the experimental results when the distance between the emitter of the air ionizer and the work area is varied. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Corona discharge air ionizers are widely used during quality control inspections to neutralize the static electricity on electronic devices because the electric field generated by static charge can lead to soft errors. However, an air ionizer may act as a source of noise, which can also lead to soft errors, because it creates a large number of ions that generate a high‐intensity electric field. The soft errors of a CMOS inverter in a large‐scale integration (LSI) were investigated in a minienvironment in which an AC corona discharge air ionizer was operated. The LSI mounted on a printed circuit board was placed 500 mm under the air ionizer, which was operated with a peak‐to‐peak voltage of 15 kV at frequencies of 1‐50 Hz. The noise in the output voltage, which is a source of soft errors, of the CMOS inverter decreased with increasing operating frequency. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The gross charge distribution in an electrified cloud has already been estimated by polarity distribution of the electrostatic field on the ground surface. While either a dipole or a tripole charge structure is commonly accepted, the increase-decrease and motion of each point charge in those models are both still unclear. This paper presents a new network of electric field mills for multipoint electrostatic measurement to evaluate the temporal variations of a simple cloud charge model with second-scale resolution. Details of our newly developed equipment are described, with an emphasis on its advantages. This network was deployed in the north Kanto area of Japan and operated during the summer season in 2020. In order to simplify the relationship between cloud charge positions and the horizontal distribution of the measured electrostatic field, an isolated thundercloud is focused on. As an initial analysis, a negative point charge model is applied to an isolated cloud observed on 27 August 2020. The quantity and height of the point charge were estimated as being approximately -20 C and 7 km, respectively. The calculated charge location is generally coincident with the C-band radar echo regions. Significant correspondence is demonstrated between the intensity distribution of the electrostatic fields measured at seven sites and that calculated with estimated point charge. This result indicates the possibility to determine the amounts and positions of cloud charges inside the dipole charge structure based on multipoint measurement of the electrostatic field.

An intercomparison for continuous monitors that measure thoron ((220)Rn) concentration was carried out using a (220)Rn chamber of National Institute of Radiological Sciences (NIRS), Japan; eleven (220)Rn monitors (four types) from nine laboratories were evaluated. The (220)Rn detection principle was the same for the eleven instruments and one reference instrument, which were commercially available silicon semiconductor detectors using an electrostatic collection method. The intercomparison results showed that there was a negative deviation of more than 30% in measured (220)Rn concentrations given by the laboratories relative to the reference values, which were obtained by making a decay-correction during the travel of (220)Rn through the sampling assembly (sample tube, filter and drying unit) and using a calibration factor. In order to elucidate the reason for this and then to investigate factors that affect the (220)Rn concentration measured with the monitors. As a result, it was necessary to make the decay-correction, in particular, when using a drying unit with a large inner volume and to use the calibration factor in order to better estimate the (220)Rn concentration. It was also found to be better to determine a calibration factor inherent to an individual monitor, because the calibration factor values ranged from 0.75 to 2.32, depending on the flow rate of the monitor pump (0.37-1.02 L min(-1)). It was concluded from this study that a periodical calibration of the monitor and a check of the monitor flow rate during measurements are necessary to maintain a consistent quality level of the (220)Rn measurement., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Purpose: The purpose of this study was to evaluate the impact of a cyclotron on small-animal PET equipment installed directly above the cyclotron., Methods: The cyclotron equipment was HM-12, which has two targets, and the PET/CT equipment was Inveon. The equipment was installed in conformity to Japanese law and regulations. Before installation of the PET/CT equipment, the radiation dose, radio waves, and static and fluctuating magnetic fields were measured at the position where it would be placed, both when the cyclotron was in use and when it was not in use. After installation of the PET/CT, natural background and emission counts were measured at the same place under the same conditions., Results: An increase of radiation dose was observed when the target nearest the PET equipment was used. There were no distinct effects of radio waves or static and fluctuating magnetic fields. A significant increase of emission counts, approximately 300 cpm, was observed when the nearest target was used., Conclusions: Though radio waves and static and fluctuating magnetic fields generated by running cyclotron had no influence, a significant increase in emission count was observed. Careful attention should be paid to this influence when very low-radioactivity PET measurements are done.

X-linked hypohidrotic ectodermal dysplasia (XLHED), which is characterized by hypodontia, hypotrichosis, and hypohidrosis, is caused by mutations in ED1, the gene encoding ectodysplasin-A (EDA). This protein belongs to the tumor necrosis factor ligand superfamily. We analyzed ED1 in two Japanese patients with XLHED. In patient 1, we identified a 4-nucleotide insertion, c.119-120insTGTG, in exon 1, which led to a frameshift mutation starting from that point (p.L40fsX100). The patient's mother was heterozygous for this mutation. In patient 2, we identified a novel missense mutation, c.1141G>C, in exon 9, which led to a substitution of glycine with arginine in the TNFL domain of EDA (p.G381R). This patient's mother and siblings showed neither symptoms nor ED1 mutations, so this mutation was believed to be a de novo mutation in maternal germline cells. According to molecular simulation analysis of protein structure and electrostatic surface, p.G381R increases the distance between K375 in monomer A and K327 in monomer B, which suggests an alteration of overall structure of EDA. Thus, we identified two novel mutations, p.L40fsX100 and p.G381R, in ED1 of two XLHED patients. Simulation analysis suggested that the p.G381R mutation hampers binding of EDA to its receptor via alteration of overall EDA structure.