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A simple mathematical expression for nonlinear resistive properties of metal oxide varistor (MOV) elements is proposed for electromagnetic and surge simulations using the finite-difference time-domain (FDTD) method. The nonlinear resistive properties of MOV elements are obtained experimentally as the voltage versus current ( V–I ) characteristics. The V–I characteristics are converted to the resistivity versus electric field ( ρ–E ) characteristics. The ρ–E characteristics are approximated by the simple mathematical expression with three adjustable constants, the values of which can be easily determined with the least square method. The proposed simple ρ–E expression is of great use in FDTD simulations since it can approximate measured ρ–E characteristics reasonably well and requires no iterative computations.

A zinc oxide (ZnO) varistor, also called a metal oxide varistor, has a resistance or resistivity that varies with the applied voltage or electric field. The nonlinear resistive properties of ZnO elements are usually obtained experimentally as the voltage versus current characteristics. It is shown that a simple mathematical expression with four adjustable constants can well reproduce measured nonlinear resistive properties of six low-voltage ZnO elements.

Objectives Fluoroquinolone (FQ)- and third-generation cephalosporin-resistant Escherichia coli are increasing in Japan. In the early 2000s, the FQ-resistant E. coli clone ST131 increased in clinical settings worldwide. It frequently produces extended-spectrum β-lactamases (ESBLs) such as CTX-M. This study aimed to explore the characteristics of FQ-resistant E. coli isolated in Japan during 2008–2009 and 2020. Methods We compared FQ-resistant E. coli clinical isolates from urine samples collected in 2020 (151 isolates) with a FQ-resistant E. coli collection isolated in 2008–2009 (42 isolates). Identification of E. coli ST131 clades and blaCTX-M were determined by multiplex PCR. Sequence types of non-ST131 isolates were determined by whole-genome sequencing. Results Although the prevalence of ST131 was comparable in 2020 (74.2%) and 2008–2009 (78.6%), the subclades differed during the two time periods (C1-nM27: 40.2% in 2008–2009 vs. 78.8% in 2020; C1-M27: 32.1% in 2008–2009 vs. 9.1% in 2020). The incidence of blaCTX-M among ST131 isolates increased from 27.3% in 2008–2009 to 64.3% in 2020. blaCTX-M was found in 80.6% and 93.8% of C1-M27 and C2 in 2020, respectively, and blaCTX-M possession in C1-nM27 increased from 19.2% in 2008–2009 to 40% in 2020. FQ-resistant ST1193 was detected only in 2020 (17.9% of 151 isolates, of which 14.8% possessed blaCTX-M). Conclusion Increased resistance of E. coli to FQs and third-generation cephalosporins in Japan can be attributed to the accumulation of blaCTX-M in C1-nM27 and the increase of C1-M27 and C2 clades with high blaCTX-M possession, alongside the spread of ST1193.

This study focuses on the relationship between test current waveforms and impulse withstand capability of metal–oxide varistors (MOVs) (withstand energy, current density, and the number of withstand shots) in repetitive impulse application and discusses the mechanical and electrical failure mechanisms. The performance and relationship of withstand energy and withstand shots for conventional 2-ms rectangular waveform, 4/10- $\mu $ s, and newly introduced 10/350- $\mu $ s impulses are investigated. Notably, the 10/350- $\mu $ s waveform has aspects of both steep rise impulse and long duration impulse. In addition, the varistor voltage change after repetitive impulse applications for 10/350- $\mu $ s and 4/10- $\mu $ s waveforms is investigated. There is no direct relationship between varistor voltage drop and repetitive withstand shots. However, ${V}_{1\ {\rm mA}}$ and ${V}_{0.01\ {\rm mA}}$ changes indicate the degree of MOV damage caused by the impulses and are important factors to monitor progressive damage. Based on these findings, optimal MOV design is discussed.

Metal oxide varistors (MOVs) composed of multiple MOVs connected in parallel have benefits, including compactness and the potential to realize high surge withstand capability. On the other hand, it is absolutely necessary to control the V-I characteristics of each MOV connected in parallel to ensure uniform current flow between the component MOVs. If this current is not uniform, the component MOV having low voltage will puncture and degrade at a lower surge current than expected. In this paper, we have studied the distribution of electric field and current on the surface of a three-parallel MOV using the finitedifference time-domain (FDTD) method. Additionally, real impulse testing was conducted to confirm the surge withstand capability of three-parallel MOV. From the obtained results, we have concluded that the surge withstand capability of the three-parallel MOV is not decreased from the desired 3X individual surge withstand capability if the variation of V 1mA voltage between each MOV component is less than 4%.

西欧の多くの都市で,交通問題解決,都市の再生と環境保全を目的として,自動車依存の体系から,徒歩とLRT(Light Rail Transit)等の公共交通中心の都市構造への転換が進んでいる。本論は,フランスを対象として,代表的な3都市について現地調査,政策担当者ヒアリングを行った結果について述べる。中心的な課題は,LRT整備が都市に与えた影響および事業化に伴う利害調整の取組状況の分析である。これらに基づいて,日本のLRT整備に関わる課題について考察する。

Background Gold nanoparticles are promising nanomaterials for catalytic reactions, sensing/imaging systems, photonic/plasmonic devices, and electronics because of their unique physical and chemical properties. To date, significant catalytic activities of gold nanoparticles have been reported for reactions such as carbon monooxide oxidation and 4-nitrophenol reduction, and diverse gold nanoparticle morphologies such as nanospheres, wires, rods, and cubes have been achieved using a variety of capping/stabilizing organic molecules. However, there are few reports on the simultaneous assembly of peptides forming secondary structures and metallic nanoparticles into peptide-metallic particle hybrids under mild aqueous conditions and demonstration of their use as catalysts. Furthermore, the gold nanoribbon surfaces are covered with β-sheet structures, disrupting the access of substrates to the active sites, thereby possibly inhibiting their catalytic activity. Objectives The main objective of this study is design, synthesis, and characterization of peptidegold nanoparticle hybrids that are prepared by an α-helical conformation of a template and examination of the catalytic activities of the hybrids. Methods We here report (i) the design, synthesis, and characterization of a new template peptide, RU025, that tends to form an α-helical conformation and self-assembles into network nanoarchitectures in aqueous solution through possibly hydrophobic and electrostatic interactions, (ii) the characterization of gold seed crystals synthesized by mixing RU025 and HAuCl4, (iii) the characterization of peptide-gold nanoparticle hybrids directed by crystal growth with NaBH4 and the dependence on the conditions used for nucleation, and (iv) the catalytic activities of the hybrids towards the reduction of 4-nitrophenol to 4-aminophenol in the presence of excess NaBH4. Results We demonstrated the design, synthesis, and characterization of a new template peptide, RU025, that tends to form an α-helical conformation and self-assembles into network nanoarchitectures in aqueous solution. Gold seed crystals were synthesized by mixing RU025 and HAuCl4 in a 1:2 molar ratio, followed by further reduction of the gold seed crystals with NaBH4. This reaction afforded worm-like gold nanoparticles embedded in the peptide self-assemblies. The peptide-gold nanoparticle hybrids exhibited catalytic activities for the Langmuir-Hinshelwood type reduction of 4-nitrophenol to 4-aminophenol in the presence of excess NaBH4, with an activation energy of 33 kJ mol-1. Conclusion The size and morphology of gold nanoparticles can be tuned in the nanometer range by altering the peptide concentration relative to HAuCl4 and by changing the nucleation time. This method for constructing peptide-metallic nanoparticle hybrids, in which metallic nanoparticles are dispersed in the peptide self-assemblies, provides highly reactive catalysts.

西欧諸国の多くの都市で,都市の成長や環境保全を目的とした都市交通体系の転換が進められている。具体的には,自動車依存の体系から,徒歩と公共交通中心の都市構造へ変えようとするものである。本論は,このような都市交通政策の転換が最も進んでいると考えられるフランスを対象として,まず,それを支える法制度,財源制度について述べる。次に,実際にこのような政策を実施している代表的な3都市を選んで,現地調査,政策担当者ヒアリングを行った結果について述べる。このことから,日本の都市交通政策の課題について考察する。

In Japan, the merit of installing LRT (Light Rail Transit) is well known, however the introduction of LRT to urban areas is not making progress. To study effective strategies of LRT adaption, field surveys were conducted at cities where LRT systems were placed in Spain with data collection of urban characteristics adjacent conditions, accommodating spatial conditions, effectiveness of service and project management. This paper aims to clarify the specific requirements to make LRT adaption possible. The results indicate, beyond the need for middle range transportation systems, the importance of the following: potential contribution to inner city revitalization, environmental concerns, land use conditions and spatial composition needed by adjacent businesses.

Background: Multidrug-resistant Escherichia coli, especially a lineage of O25b:H4-ST131, has increased and spread worldwide. The surveillance of cross-resistance of E. coli is necessary. Methods: Cross-resistance to fluoroquinolones (FQs) and aminoglycosides (AGs) was examined in E. coli isolated in Hokkaido Prefecture, Japan, between 2008 and 2009. Results: Gentamicin (GEN) resistance was more common in FQ-resistant isolates (30/112 strains; 26.8%) than in FQ-susceptible isolates (2/100 strains; 2%). The frequency of GEN resistance was similar in two groups of FQ-resistant strains, O25b:H4-ST131 genotype (22/87 strains; 25.3%) and a group of other FQ-resistant genotypes (8/25 strains; 32.0%). The main AG resistance gene was aac(3)-II (87.5% of GEN-resistant strains). The only amikacin-resistant strain which was FQ resistant carried the aac(6')-Ib-cr gene. CTX-M type extended-spectrum β-lactamase (ESBL) genes were also found in FQ-resistant strains at a high frequency. However, the number of strains with both ESBL and AG-modifying enzyme genes was relatively low (8 strains). Conclusion: All FQ-resistant strains, not only O25b:H4-ST131, appeared to preferentially acquire ESBL genes and/or genes encoding AG-modifying enzymes; however, the acquisitions of these genes seemed to occur independently.

This study focuses on current distribution in a metal oxide varistor (MOV) element stressed by 4/10 μs impulse current studied using the finite-difference time-domain (FDTD) method. After 100 kA shots, V 1mA/ mm values, which indicate deterioration of nonlinear characteristics of MOV, in edge parts of MOV elements decreased more than those in center parts. FDTD analysis was conducted in two ways, namely 1-D and 3-D models. The varistor is represented with many nonlinear cubic cells of 3 mm × 3 mm 0× 3 mm It turns out from the 3-D FDTD analyses that the skin effect is insignificant for a lightning current having a rise time of 4 μs. However, if there is small difference in the nonlinear characteristic of a ZnO element between its periphery and other parts, the distributions of current density are considerably affected, which may result in enhanced degradation of a varistor element in its periphery.

The Bi2O3 based ZnO varistors (MOVs) are used in surge arresters or surge protective devices (SPDs) as key components. As their performance, MOVs shall have I-V non ohmic characteristics, higher surge withstand capability and reliability for ageing: When AC power line voltage is applied to MOV, its leakage current or watt loss shall be decreased continuously.In order to maintain reliability for ageing, it is known that additional heat treatment after sintering process in MOV manufacturing flow is effective. The mechanism of the heat treatment effect was considered to be realized by a crystal structure change of the bismuth oxide as a main material which forms a grain boundary. However, in this study, it is found that watt loss behavior does not necessarily correspond to crystal structure of the bismuth oxide. Besides, from the fact that ZnO which dissolve in Bi2O3 liquid phase is compounded with other additives by heat treatment, precipitation of ZnO in Bi2O3 liquid phase by heat treatment can be considered as important factor.In addition, uniformity not only in grain boundary structure from a microscopic of view, but also of size and its distribution of the multiple points from a macroscopic of view is integrant in order to realize MOVs having lower watt loss and its stability.

本論文では,道路空間の「公共性」に関する市民意識を形成する構造をアンケート調査から日独比較分析することで,道路空間利用に関する社会的合意形成のための有効な方策に資することを目的とした。アンケート調査結果によれば,日本(堺市)でもドイツ(ヴュルツブルク市)でも,現在の都心部における自動車による交通混雑,交通事故,生活・歩行環境の悪化,商店街等の活力低下などの面から,都心部への自動車乗り入れ規制を容認する意識が強い。次に,日本では自宅直近の道路に対する「私的」感が強いが,ドイツでは,他の人々による道路の多様な使われ方に寛容であり「私的」感は薄い。逆に,自宅前道路の通行規制や道路整備に伴う建物移転など,公共による私権制限に対する反発はドイツの方が強く,日本の方が公共的な事業に対する協力意識は高い。以上のことを路面公共交通整備のための道路空間の再配分という観点から整理すると、以下のことがいえる。まず、ドイツでは意識面から私的制限に対する抵抗の大きさの反映として、社会的合意を得るための法体系、ガイドライン・基準の整備状況、情報公開制度、予算的裏付け等が適切に整備されていると考えることができる。わが国では、これらがあいまいなまま、ある場合には行政の恣意的施策と地域有力者だけの根回しで進められた事業も多いと考えられ、行政と市民の不幸な相互不信感を生み出す一要因となっている。近年のわが国市民の権利意識の増大と行政活動の公平性・透明性・客観性の確保という点から、ドイツに倣った同様の「仕組み」を整えればLRT整備が急速に進む可能性はある。その際、わが国の直近道路空間に対する「私的感」にも十分に配慮した計画内容とすることが合意を進める上で重要である。, This paper explores better ways to establish social consensus when developing Light Rail Transit (LRT) systems in Japan. For this purpose, an inquiry into the attitudes of private users toward road space was made in Japan and Germany. On the basis of this comparative analysis, users' (or stakeholders') attitudes and opinions indicated that the development of LRT systems themselves was not such a crucial issue. In contrast, however, issues involving public awareness of the processes of development and the systems employed in constructing LRT's, such as regulations, guidelines, standards and access to information, are considered crucial.

We identified and genetically characterized seven fluoroquinolone-resistant Streptococcus pneumoniae strains among 293 clinical strains isolated from 1999 to 2001 in Japan. The resistant strains were isolated only from adults, and 7 of 31 isolates (22.6%) were from patients more than 20 years old. Resistant strains were not found in 262 isolates from children under age 10.

Multidrug-resistant Escherichia coli, especially a lineage of O25b:H4-ST131, has increased and spread worldwide. The surveillance of cross-resistance of E. coli is necessary.Cross-resistance to fluoroquinolones (FQs) and aminoglycosides (AGs) was examined in E. coli isolated in Hokkaido Prefecture, Japan, between 2008 and 2009.Gentamicin (GEN) resistance was more common in FQ-resistant isolates (30/112 strains; 26.8%) than in FQ-susceptible isolates (2/100 strains; 2%). The frequency of GEN resistance was similar in two groups of FQ-resistant strains, O25b:H4-ST131 genotype (22/87 strains; 25.3%) and a group of other FQ-resistant genotypes (8/25 strains; 32.0%). The main AG resistance gene was aac(3)-II (87.5% of GEN-resistant strains). The only amikacin-resistant strain which was FQ resistant carried the aac(6')-Ib-cr gene. CTX-M type extended-spectrum β-lactamase (ESBL) genes were also found in FQ-resistant strains at a high frequency. However, the number of strains with both ESBL and AG-modifying enzyme genes was relatively low (8 strains).All FQ-resistant strains, not only O25b:H4-ST131, appeared to preferentially acquire ESBL genes and/or genes encoding AG-modifying enzymes; however, the acquisitions of these genes seemed to occur independently.

The data on interactive actions between running vehicles should be obtained when making microscopic traffic simulation models based on Car Following Theory. In this paper, the data collection method using GPS is proposed. The GPS device installed to each car observes the velocity and location every second and based on those data, the headway and the reaction time-lag data can be calculated. Using this method, the data on various kind of traffic conditions and road conditions can be obtained. The usefulness of the method is apparent by applying the data to our microscopic traffic simulation model.

The purpose of this study is to analyze the relationship between the change of the character of an area and the transportation network improvement. We first collected the data regarding the increasing rate of the number of the population and industrial employees in Kinki Area. In the basis of those data, we investigated the difference of the rate between the districts where the transportation network is much improved and the ones where not so improved. As a result, this study displays the change of the character is depend upon the transportation network improvement.

Lightning protection using surge protective devices (SPDs) have an important role for reliability of power delivery in current advanced information technology society. SPDs are categorized by 3 test class (Class I, II and III) according to IEC 61643-11) [1]. Especially, because class I SPDs intend to install at the entrance of power line according to IEC 61643-12) [2], it is important how big current SPD withstands. As components of SPD in Low voltage power distribution system, metal oxide varistors (MOVs) and/or spark gaps (GDT) were mainly used. SPDs with MOVs are voltage limiting type and have some merits as follows compared to that with GDT. • Capability of cut off the follow current • Lower residual voltage • Quickly response However, from surge withstand capability of the view, it is easy for MOVs to degrade its electrical characteristics by surge current because it translates from surge energy to heat itself. This point is a drawback for MOVs. This study describes the degradation mechanism of MOVs by surge impulses and the approaches for high and stable surge withstand capability through 10/350us impulse test results.