Microscale Surface Patterning of Zirconia by Femtosecond Pulsed Laser Irradiation

Yuka Yamamuro,Tomotaka Shimoyama,Jiwang Yan 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

Irradiation of yttria-stabilized zirconia (YSZ) was performed by a femtosecond pulsed laser to investigate the feasibility of V-shaped groove microstructure fabrication. Firstly, fundamental characteristics of microgroove fabrication was investigated by varying scanning speed of laser and number of scans. Higher scanning speed resulted in a smooth surface without any debris adhesion. By increasing number of scans, the cross-sectional profile of the microgroove became a well-defined V shape, and the taper angle of the V-shaped groove can be precisely controlled by laser scanning speed. Moreover, the laserinduced phase transformation of YSZ was characterized, and it was found that the monoclinic ratio after irradiation decreased in comparison with original YSZ surface, indicating improved strength and toughness. TEM cross-sectional observation of the microgrooves was performed and tetragonal phase was detected independent of locations. Finally, micro pyramid structures were created on the YSZ surface by perpendicularly crossing the laser scan directions. The resulting surface showed a drastic change in surface wettability. These findings demonstrated the possibility of generating precise complex microstructures on YSZ surface with high functionality and low subsurface damage, presenting great potential of wide applications in industry.

幕末における米価の暴騰と暴落に関する考察

山室恭子(Yamamuro, Kyoko),李昌玟(Lee, Chang Min) 동아시아일본학회 2014 일본문화연구 Vol.0 No.49

This paper analyzes the phenomenon of the sudden rise and decline in rice prices at the end of the Edo period. Specifically, it estimates a new price index based on the Mitsui clan’s price bulletins to explain abnormal fluctuations in rice prices. While general commodity prices increased only two to three times over the one-year period from January 1866 to January 1867, rice prices increased by more than 10 times during the same period. The initial rise in rice prices was inspired by anxiety related to the Second Ch?sh? Expedition. After the defeat of the Tokugawa Shogunate, the monetary economy, which had been maintained through trust in the shogunate collapsed and people started to buy rice as a substitute investment. As rice prices soared, the shogunate introduced market competition into rice transactions, so that ordinary merchants who were not rice traders also became able to participate in this market. The shogunate hoped that free competition would lead to depreciated rice prices, but ordinary merchants hoarded rice as one facet of their investment activities, which led to even greater inflation. However, rice was an investment that could not be stored for a long time: ordinary merchants did not possess storage technologies or large warehouses, and thus, when the stored rice got spoiled in the summer season, the merchants offloaded all of their stock at once. Consequently, rice prices declined sharply in 1867, just one year later.

동아시아 근대 지성의 동아시아 인식 ; 일본의 아시아주의와 아시아 학지(學知)

야마무로신이치 ( Yamamuro Shinich ) 성균관대학교 대동문화연구원 2005 大東文化硏究 Vol.50 No.-

역사학과 인문 · 사회과학의 현재, 그리고 기대의 지평으로

야마무로신이치 ( Yamamuro Shinichi ),이한결(번역) 연세대학교 국학연구원 2017 동방학지 Vol.178 No.-

본 논문은 동아시아 역사연구포럼이 교토대학 인문과학연구소·동북아역사재단과 공동개최한 국제연구 심포지엄에서 `동아시아에서의 역사인식과 역사교육 - 인문·사회과학의 과제와 가능성`이라는 주제를 왜 설정할 필요가 있는가를 일본의 시점에서 논한 것이다. 1990년대 이후, 동아시아 각국에서는 인문사회과학의 연구지원체제의 재편성 방식에 관한 시행착오가 지속되고 있다. 그 가운데 경제적인 글로벌화에 따라 학술연구에서의 `세계랭킹`에 대한 대응방향, 학술연구의 평가방식, 학술·교육예산의 효율적인 배분방법, 그리고 인문·사회과학 연구의 사회적인 유용성과 같은 문제들에 대해 인문·사회과학 연구자들은 해답을 낼 것을 요구받고 있다. 경제성장에 도움이 되는 자연과학연구는 필요하지만 인문·사회과학은 불필요하다는 식의 논의가 있는 가운데, 인문·사회과학의 연구자가 당연히 응답해내야 할 책임이기도 하다. 다른 한편, 제2차 세계대전으로부터 70년을 거쳐, 동아시아 각국에서는 일국사를 중심으로 구성되어온 역사교과 과목 재검토, 역사교과서 개정과 같은 움직임이 활발해지고 있다. 일본에서는 일본사·세계사와 같은 분야를 횡단하는 `역사통합`과목이 고등학교에서 필수과목으로 지정될 예정이다. 이러한 움직임과 병행하여 종군 위안부문제·남경대학살문제 등에 관하여, 일본에서는 한국이나 중국에서의 세계기억유산등록을 반대하는 논의가 수년간 이어지고 있다. 그곳에서는 `역사전쟁`에 승리한다는 명목으로, 역사인식과 역사교육에서의 반한·반중의 논조가 고조되고 있는 모습을 보인다. 그리고 다시금 왜, 어떻게 역사를 인식하고 어떻게 교육하는 것이 필요한지에 대해 다시 질문받고 있다. 이렇듯 오늘날 동아시아세계에서는 인문·사회과학의 존재방식과 역사인식·역사교육의 존재방식을 둘러싼 논의가 밀접하게 서로 얽히면서, 학문연구와 교육은 무엇을 위해 존재하는 가라는 근본적인 질문으로 분출하고 있다. 그러한 가운데 우리들에게 요청되는 것은 각각의 연구자가 국적·세대·성별 등의 경계를 넘어서, 동아시아라는 리저널한 시각으로부터 글로벌과 내셔널의 차원에서 일어나고 있는 문제에 접근하여, 자유롭게 토의한다는 기점(基点)으로 되돌아가는 것이다. 그러한 때에 확인해두고자 하는 것은 사회나 세대를 넘어서 다양성을 지니는 문화의 지속적 가능성을 유지하기 위해서는, 분과·세분화되어 버린 인문·사회과학을 `인문학`으로 재구성하고, 연구·교육의 다양성과 지속성을 확보하기 위한 국제공동연구가 필요불가결하다는 인식이다. Since the 1990s, East Asian countries have been undergoing higher education reforms, particularly surrounding issues of research support system in Humanities and Social Sciences. In this process, researchers in such fields have been required to prove their social usefulness. Meanwhile, there has been growing interest in the reforms of history education and textbook among East Asian countries which have stressed on the nation-centered history over the last 70 years. The recent movement of history education in Japan has two distinct aspects: Teaching “comprehensive history” that crosses national boundaries in high school on the one hand, and the growing discussion on “struggles of history” that ignites anti-Korean and anti-Chinese sentiments. These two aspects urge us to reconsider the ways in which we perceive and educate history. In recent years, there have been interwoven discussions of the roles of Humanities and Social Sciences and those of historical perception and history education in East Asian nations. This led to a fundamental question of the reasons for the existence of academic research and education. In order to find an answer, researchers need to cross the national, generation, and gender boundaries and have an open discussion about global and national issues from a regional―i.e. East Asian-perspective. It is also essential to reconstruct the Humanities by integrating different disciplines and facilitate international academic collaboration to maintain cultural multiplicity and sustainability across the social and generation boundaries.

서학(西學)에 의한 만국인식의 변용과 동아시아 국제질서 : 사상연쇄(思想連鎖)의 시각에서

야마무로 신이치(Yamamuro Shinichi),서민교 (번역자) 인제대학교 인간환경미래연구원 2009 인간 · 환경 · 미래 Vol.- No.3

인문ㆍ사회과학이라는 시각으로부터 서학(西學)의 수용사를 포착하고자 할 때, 그것을 중화(中華)제국을 중심축으로 둔 동아시아 세계질서에 대한 ‘도전으로서의 서학’이라는 관점에서 출발하여 구미(歐美)로부터의 ‘충격으로서의 서학’에로 전개되었던 역사로서 개괄하는 것이 가능할 것이다. 그러한 서학으로부터의 충격에 대해서는 ‘서학의 수용’과 ‘서학에 대한 반발’이라는 대립적인 대응이 나타나지만 그 과정에 있어서 ‘만국인식의 사상연쇄’야말로 동아시아 국제질서를 변용시키고 재편성하였던 추동력이었다. 본고에서 제기한 ‘만국인식의 사상연쇄’라는 것은 만국도(萬國圖)로부터 만국사(萬國史)로, 나아가 만국법(萬國法)과 연결된 사상연쇄임과 동시에 그것이 조선, 중국, 일본 사이에서 상호교섭과 상호규정의 연쇄과정까지도 분명히 하고자 하는 것이다. 그러한 사상연쇄의 결과로서 한국 중국 일본 각각의 정치사회에 있어서 세계관의 전환이 생기고 나아가 동아시아 국제질서의 변환이 발생하고 나아가 동아시아 국제질서의 재편성을 촉진하게 되었다. 그러나 서학은 ‘배워야 할 사표(師表)’임과 동시에 동아시아 세계에 있어서는 어디까지나 ‘배척해야 할 이물질’로 서의 측면, 나아가 ‘침략해 온 외적’이라는 측면을 갖고 있었다는 것도 부정할 수 없을 것이다. 그것이 현시점에서 또 미래에 어떠한 의미를 갖는가에 대해서도 고찰하고자 하였다.

EFFECTS OF HYPOPHYSECTOMY ON PROGESTERONE PRODUCTION IN THE FOLLICULAR GRANULOSA CELLS OF THE JAPANESE QUAIL

Mori, M.,Kimora, K.,Yamamuro, H. Asian Australasian Association of Animal Productio 1988 Animal Bioscience Vol.1 No.3

In order to investigate the mechanism of regulation of progesterone production, quail were hypophysectomized at various times during the ovulation cycle, and granulose cells were isolated from follicles 4 hr after the operation. They were incubated in vitro at $40^{\circ}C$ with or without LH or dibutyryl cyclic AMP, and the amounts of progesterone produced during 3 hr of incubation were measured by radioimmunoassay. Hypophysectomy at 8 hr or 20 hr before the predicted time of ovulation caused a reduced responsiveness of F1 granulosa cells to exogenous LH or dibutyrul cyclic AMP. Although hypophysectomy at 24 hr before ovulation caused a slight reduction of responsiveness of F1 granulosa cells, the reduction of the progesterone production during the incubation without any stimuli was prominent by the sham operation. These results suggest that the presence of pituitary gland influences the ability of the granulose cells to produce progesterone in response to LH or dibutyryl cyclic AMP.

Effects of fines content on void ratio, compressibility, and static liquefaction of silty sand

Lade, Poul V.,Yamamuro, Jerry A.,Liggio, Carl D. Jr. Techno-Press 2009 Geomechanics & engineering Vol.1 No.1

Many aspects of the behavior of sands are affected by the content of non-plastic fine particles and these various aspects should be included in a constitutive model for the soil behavior. The fines content affects maximum and minimum void ratios, compressibility, shear strength, and static liquefaction under undrained conditions. Twenty-eight undrained triaxial compression tests were performed on mixtures of sand and fine particles with fines contents of 0, 10, 20, 30, 50, 75, and 100% to study the effects of fines on void ratio, compressibility, and the occurrence of static liquefaction. The experiments were performed at low consolidation pressures at which liquefaction may occur in near-surface, natural deposits. The presence of fines creates a particle structure in the soil that is highly compressible, enhancing the potential for liquefaction, and the fines also alter the basic stress-strain and volume change behavior, which should be modeled to predict the occurrence of static liquefaction in the field. The void ratio at which liquefaction occurs for each sand/fines mixture was determined, and the variation of compressibility with void ratio was determined for each mixture. This allowed a relation to be determined between fines content, void ratio, compressibility, and the occurrence of static liquefaction. Such relations may vary from sand to sand, but the present results are believed to indicate the trend in such relations.

Characteristics of electrodeposited bismuth telluride thin films with different crystal growth by adjusting electrolyte temperature and concentration

Masaki Yamaguchi,Hiroki Yamamuro,Masayuki Takashiri 한국물리학회 2018 Current Applied Physics Vol.18 No.12

Bismuth telluride (Bi2Te3) thin films were prepared with various electrolyte temperatures (10°C–70 °C) and concentrations [Bi(NO3)3 and TeO2: 1.25–5.0 mM] in this study. The surface morphologies differed significantly between the experiments in which these two electrodeposition conditions were separately adjusted even though the applied current density was in the same range in both cases. At higher electrolyte temperatures, a dendrite crystal structure appeared on the film surface. However, the surface morphology did not change significantly as the electrolyte concentration increased. The dendrite crystal structure formation in the former case may have been caused by the diffusion lengths of the ions increasing with increasing electrolyte temperature. In such a state, the reactive points primarily occur at the tops of spiked areas, leading to dendrite crystal structure formation. In addition, the in-plane thermoelectric properties of Bi2Te3 thin films were measured at approximately 300 K. The power factor decreased drastically as the electrolyte temperature increased because of the decrease in electrical conductivity due to the dendrite crystal structure. However, the power factor did not strongly depend on the electrolyte concentration. The highest power factor [1.08 μW/(cm·K2)] was obtained at 3.75 mM. Therefore, to produce electrodeposited Bi2Te3 films with improved thermoelectric performances and relatively high deposition rates, the electrolyte temperature should be relatively low (30 °C) and the electrolyte concentration should be set at 3.75 mM.

Evaluation of a Probability Density Function Approach for Turbulent Jet Diffusion Flames

S. Noda,Y. Horitani,K. Yamamuro 한국전산유체공학회 2003 한국전산유체공학회 학술대회논문집 Vol.2003 No.10

RESTRICTION BY MOTHERWORT (Leonurus sibiricus L) OF LACTATION SUPPRESSED BY PREGNANCY-DEPENDENT MAMMARY TUMORS IN GR/A MICE

Nagasawa, H.,Suzuki, M.,Inatomi, H.,Hibino, A.,Yamamuro, Y.,Sensui, N. Asian Australasian Association of Animal Productio 1991 Animal Bioscience Vol.4 No.1

As a possible step to evaluate in the mammary gland the role of motherwort (Leonurus sibiricus L), a representative medicinal plant used traditionally for the therapy of gynecologic diseases, the effects of the agent on lactation which was suppressed by preganacy-dependent mammary tumors (PDMT) were studied in GR/A mice. Beginning the day of placing with males at 45-50 days of age, female mice were given 60% methanol-extract of the aerial part of motherwort as drinking water at the concentration of 0.5% throughout the experiment. Mice developing PDMT during pregnancy [PDMT(+)] and given motherwort were similar to mice developing no PDMT [PDMT(_)] with or without motherwort treatment and were significantly higher than PDMT(+) mice given tap water in litter growth and mammary RNA/DMA ratio on day 12 of the 2nd lactation. Mammary DNA and RNA contents were also elevated by motherwort in PDMT(+) mice. The results suggest that motherwort can ameliorate lactation suppressed by PDMT through its stimulation of both growth and function of the mammary glands.