http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nishimoto, Kazutoshi,Woo, In Su 대한금속재료학회(대한금속학회) 2001 METALS AND MATERIALS International Vol.7 No.3
A study was carried out to determine the effect of cerium addition on HAZ cracking susceptibility in cast alloy 718 welds. The cause of HAZ cracking was also investigated using commercial cast alloy 718 varying in grain size at three levels. The hot cracking test results for commercial cast alloy 718 indicated that the fine-grained alloy was less sensitive to HAZ cracking. Furthermore, cerium addition of up to 0.3 wt.% was found to have a beneficial effect in reducing HAZ cracking susceptibility. When cerium addition exceeds 0.3 wt.%, HAZ cracking susceptibility increased further. The mechanism of HAZ cracking was found to be related to intergranular liquation caused by the eutectic melting of sulfur containing a laves cluster at the grain boundaries. The degree of grain boundary liquation in the fine-grained specimen was less than that of the coarse-grained specimen due to a decrease in the amount of laves cluster and sulfur segregation in it at the grain boundaries, which seems to be responsible for a reduction in hot cracking susceptibility in the fine-grained specimen. Microscopic observation suggested that the improved HAZ cracking susceptibility in cerium containing alloy could be attributed to a reduction in the amount of laves cluster and sulfur segregation in it at grain boundaries due to the grain size reduction and sulfur-scavenging effects of cerium.
Nishimoto, Kazutoshi,Woo, In Su,Kang, Chang Yun 대한금속재료학회(대한금속학회) 2001 METALS AND MATERIALS International Vol.7 No.4
The factors affecting intergranular liquation cracking susceptibility in electron beam welds were investigated for cast alloy 718. The materials used were as-received plates and heat-treated plates with three different levels of grain size. Liquation cracking susceptibility in HAZ was evaluated by a bead-on-plate test and a restraint/relaxation U-type hot cracking test. The penetrated shapes in the welds were classified into wine cup-like Type W and nail head-like Type N. For a given beam current, Type W and Type N were observed at the lower and higher welding speeds, respectively. Welding defects, i.e., underfills and microcracks were seen in the electron beam welds. Compared with Type W, the liquation cracking was more sensitive for the Type N bead cross sectional shape. Furthermore, it easily occurred at grain boundaries in Region II, i.e., very near the nail head necked part. According to the restraint/relaxation U-type hot cracking test, the liquation cracking susceptibility decreased with decreasing grain size or with homogenization heat treatment. These results suggested that the liquation cracking susceptibility in cast alloy 718 electron beam welds could be improved by using the Type W bead cross sectional shape, a decreasing the grain size and using appropriate heat treatment before welding.
Tinea Pedis: An Opportunistic Infection of The Skin
Nishimoto, Katsutaro 대한의진균학회 2001 대한의진균학회지 Vol.6 No.4
In Japan, the average incidence of tinea pedis among dermatology out-patients is around 10%. Obviously this does not reflect the true invasion of dermatophytes on human skin. Several attempts to elucidate the incidence of tinea pedis among the population revealed nearly 40% of randomly chosen patients at dermatology clinics suffered from tinea pedis with an increasing incidence by age group. Furthermore, results obtained from regular medical checks of healthy adults at Nagasaki Municipal Hospital revealed more than 30% of the recruits had only a slight scaling of mild hyperkeratosis which could not be differentiated clinically from other pathological or even age-related changes. Nearly two-thirds of these tinea penis lesions are left untreated, or even unnoticed as a disease. Several experiments to prove the presence of dermatophytes from healthy-looking skin revealed the possibility of the presence of subclinical lesions or carriers of dermatophytes accumulating around these tinea pedis patients. Uncontrolled tinea pedis lesions are a major cause of tinea unguium, which is expensive and time-consuming to cure especially in the aged. There are no standardized treatment modalities for tinea pedis patients focusing on the complete cure. But the difficulties to eradicate the pathogens from their host are common among opportunistic infections. Also the dissociation of the number of patients and the population having the pathogens without apparent lesions, i.e. healthy carrier, is a characteristic of opportunistic infection. Undetected tinea penis patients are problematic since they are source of infection for others. Discovering and treating the hidden patients is becoming a public health problem, as well as a private hazard. Prevalence of pathogens in the host tissue and low mobility rate are a feature of opportunistic infections. The control of methods for tinea penis as an opportunistic infection should also be taken under consideration. [Kor J Med Mycol 6(4): 207-212] Key Words: Tinea pedis, Prevalence, Anthropophilic dermatophytes, Opportunistic infection, Healthy carrier
시간에 관한 풍요로움과 빈곤의 관념 -속도사회에 대한 의문제기-
니시모토이쿠코 ( Nishimoto Ikuko ),허문경 ( Moon Kyung Heo ) 한국슬로시티연구학회 2012 슬로시티연구 Vol.6 No.-
최근 ‘슬로라이프(slow life)’, ‘슬로푸드(slow food)’가 주목받고 있지만, 역사를 거슬러 올라가면 시간의 문화는 산업화에 의해 크게 변화하였고 이무렵 속도사회에 대한 비판이 시작되었다. 19세기 후반 영국사회에서는 ‘빠름’과 ‘바쁨’, 이에 따른 돌연사를 우려하였고, 19세기 후반 미국의 F. Taylor(테일러)에 의해 과학적 관리방법이 확립되고 20세기 초반 일본에 도입된 이후 일본사회 곳곳에서 가속화현상이 관찰되었다. 일본사회의 시간감각은 에도(江戶)시대에는 계절에 따라 해가 뜨는 시각에 따라 다를 정도로 느긋하였으나, 1873년 태양력의 도입과 함께 서구의 기계식 시계를 사용하게 되면서 크게 변화하였다. 일찍이 메이지(明治)시대 문학작품에는 이러한 사회의 변화를 우려하는 목소리가 나타난다. 저자는 근대화에 의해 비롯된 시간감각의 변화와 스트레스, 능률주의와 그에 대한 반발을 풍부한 사례를 들어 설명하는데 ‘빨리빨리’에 길들여진 한국사회에 시사하는 바가 크다.
Growth of ZnO Thin Films by Using MOCVD with a High-Speed Rotating Disk Reactor
Naoki Nishimoto,Obuliraj Senthilkumar,Takahiro Yamamae,Kasilingam Senthilkumar,Yasuhisa Fujita 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5
ZnO thin films were grown by using MOCVD with separated nozzles and a vertical-type highspeed rotating disk reactor. The interaction between source gases is prevented by the separated nozzles. The high-speed disk rotating system realized laminar flow by suppressing the thermallyinduced buoyancy flow, and it will be possible to inhibit the oxygen vacancies because the source gases are attracted on the substrate by the centripetal force. High thickness uniformity of below 2.0 % variation was obtained in 2-inch-diameter wafers. The results of the photoluminescence and the Hall-effect easurements were compared to the results obtained for conventional orizontal-type reactor and showed a suppression of the green emission band and of the carrier concentration, which shows the advantage of the high-speed rotating disk reactor.
Numerical Study on Supersonic Mixing Enhancement with a Ramp Injector and a Cavity
Fumihiko NISHIMOTO,Kohei YAMAGUCHI,Shigeru ASO,Yasuhiro TANI 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
In the present study, supersonic mixing enhancement has been investigated computationally for a SCRAM-jet engine model combustor with a swept ramp injector and a cavity. The calculation condition of the main stream are Ma = 3.96, total pressure 1.27 MPa and total temperature 283 K. In order to enhance the mixing among fuel and air a cavity is placed downstream of the ramp injector. The position and geometry of the cavity plays an important role in mixing efficiency. Therefore L/D and the Length from the ramp to the cavity have been varied. From numerical results. the mixing efficiency was the highest when L/D =2, but the total pressure loss was also the highest compared to L/D= 1,3 and 4.