• Elastomers and Composites
• /
• 제36권2호
• /
• pp.111-120
• /
• 2001

NR/NBR 혼합고무 컴파운드의 기계적 물성과 아연 및 황동피복 강선과의 접착특성에 대해 NR/NBR 조성비에 대한 함수로 조사하였다. Mooney 점도와 응력이완시간은 NBR 함량의 증가에 따라 감소하였다. NBR 함량증가에 따라 모듈러스는 전반적으로 증가하였고, 인장강도의 경우 NBR 함량이 40 phr 이하일 경우 유사한 수준을 보이다가 $50{\sim}60\;phr$일 때 최소치를 보인 후 다시 증가하는 경향을 보인 반면, 파괴점에서의 변형은 NBR 함량이 50 phr 이하의 범위에서는 선형적인 감소를 보인 후 50 phr 이후에서는 거의 유사한 수준을 보였다. NR/NBR 혼합고무 컴파운드는 NR과 NBR의 유리전이온도인 $-10^{\circ}C$와 $-55^{\circ}C$에서 탄성모듈러스의 급격한 전이와 tan ${\delta}$ 피크를 나타내 비상용성 블렌드의 거동을 나타내었다. 접착력(pullout force)과 rubber coverage 공히 NBR 함량이 증가함에 따라 급격히 감소하여 NR/NBR 혼합비가 50/50인 경우 NR 컴파운드 대비 약 40% 수준을 보였고, 순수한 NBR 컴파운드의 경우 접착력은 다시 증가하여 NR 컴파운드 대비 약 90% 수준의 접착력을 보였다. Auger spectrometer 분석결과 NBR 함량이 증가할수록 황함량이 감소하였고, 이는 강선-고무간 접착계면에서 접착층이 충분히 성장하지 못했다는 것을 의미하고 접착성능 하락의 원인으로 해석하였다.

• 대한한의학원전학회지
• /
• 제22권1호
• /
• pp.121-130
• /
• 2009

Traditionally, Korean Medicine put emphasis on the treatment and health-preserve method that corresponds with circulation of nature. And acupuncture is no exception to this rule. In "Hwangjenaegyeong(黃帝內經)", some chapters present method that is changed according to the seasons. Among the chapters, there are some difference, but we can find a general theory. In spring, Yanggi(陽氣) is coming out but not strong and cannot diffuse. so the Yanggi(陽氣) hang up the middle of outer layer. Therefore, we can take some acupoints around the muscle interspace[分腠] or tiny branches of Meridian[孫絡]. In summer, Yanggi(陽氣) flourish and boil all around of the outer layer. So, we can take some acupunctural points from skin to the yang-meridian. In both fall and winter, five su point[五輸穴] make up almost of point. in fall, yanggi begin convergence. we can remove the Eum-pathogen[陰邪] and help the normal convergence by using Stream point[腧穴], River point[經穴] and Sea point[合穴]. In winter, Eum surround so solidly that the neo Yanggi(陽氣) cannot come out. So, we can break the yin by using Well point[井穴] and make be strong by Spring point[滎穴]. If we Study the method that correspond with the seasonal circulation more, we will be able to treat diseases more minutely.

• 지식경영연구
• /
• 제13권4호
• /
• pp.71-82
• /
• 2012

The purpose of this study is to investigate the effects of employees who attend graduate school on the expansion of the knowledge sharing network in their company. For this purpose, the researchers chose 10 worker-graduate students and 75 members of company 'A' that they belong to and 107 members of university 'B' that they belong to, 172 members in total. 10 overlapped employee-students were excluded. The results of this study are summarized as follow: First, the personal relations of the employee-students enhanced after they have entered the graduate school. The score for the question was 3.85 out of 5 points. Second, the employee-students played the role of the knowledge bridge between company's co-worker network and graduate school's classmate network. It was confirmed that the density of the company's network was higher than the density of the connected network of the company and the graduate school. The analysis result confirmed that the difference of the two groups was significant. This means that the company carried out exchange with more members and therefore gained various kinds of knowledge. Also, in all types of network, the structural hole of the company network was lower than that of the connected network of the company and graduate school. The ANOVA test using QAP procedure confirmed that the difference of two groups was significant (friendship network F=1.2856, p<0.05; information network F=1.278, p<0.05; and trust network F=1.23, p<0.05). It means that the company not only gained the newly acquired knowledge by the knowledge bridge of the employee-students, but also was able to share it more effectively with members. Third and lastly, the employee-students share various information related to the organization, duties and roles rest in the company throughout break time, working hours and direct inquiries. This means that the employee-students contributed to the innovation of knowledge sharing in the company by sharing knowledge that they gained from the graduate school within the company.

• 상하수도학회지
• /
• 제23권3호
• /
• pp.345-352
• /
• 2009

The purpose of inlet baffle is to distribute the flow uniformly over the entire cross-sectional area of the sedimentation basin. The goal when designing this baffle is to achieve some head loss while keeping the velocity gradients through the ports equal to the velocity gradient in the end of the flocculator, so as to not break up the flocs. Sedimentation tank performance is strongly influenced by hydrodynamic and physical effects such as inlet design. This study was conducted to evaluate the effect of open ratio of the inlet baffle on hydraulic behavior within a rectangular sedimentation basin using CFD simulation and ADV technique. In order to verify the CFD simulation, we measured the factual velocity at 18 points in the full-scale sedimentation basin at Y water treatment plant. Good agreement was obtained between the CFD predictions and the experimentally measured data. From the simulation results of the existing basin with 7.4 % open ratio, it was investigated that extreme decrease in velocity occurred in the middle of basin. Since then, flow features was unstable. The region which the velocity decrease rapidly moved forward to the flow direction in proportion to the increase of inflow velocity. Also, it was investigated that the flow characteristic of 6.0 % open ratio was significantly different from 7.4 % open ratio at the same configuration condition. These results are a clear indication that inflow momentum and open ratio are the parameters affecting the characteristics of hydraulic patterns. The influence of these parameters on the sedimentation performance requires further study.

• 대한기계학회논문집A
• /
• 제34권8호
• /
• pp.1059-1065
• /
• 2010

본 연구에서는 SMART 원자로의 사류형 원자로냉각재펌프의 축소모형에 대한 수력성능을 예측하기 위하여 설계점을 포함한 다양한 탈설계점에서의 해석을 수행하였다. 계산시간의 효율성을 위하여 임펠러와 디퓨저 각 1개 유로로 이루어진 계산영역을 해석대상으로 선정하였다. 임펠러와 디퓨저간의 정보교환을 위하여 스테이지 기법을 사용하였다. 정상상태 비압축성 유동조건에서 축소모형의 수력성능특성을 파악하기 위하여 해석영역의 입구와 출구에서 압력차를 측정하여 양정, 효율과 축동력을 산출하였다. 수력성능 곡선은 일반적인 사류펌프의 성능특성을 잘 모사하는 것으로 나타났다. 저유량에서의 펌프 내부유동의 복잡한 흐름을 확인 하였다.

• 한국화재소방학회논문지
• /
• 제34권1호
• /
• pp.79-88
• /
• 2020

이 연구는 초고층건축물의 고층부에서 소방력의 공급의 효율성을 분석하고 이를 효율적으로 공급하는 방안을 제안하였다. 연구결과는 다음과 같다. 첫째, 화재감지는 외부에서 경보·진동·음성 등 화재경보의 다양화, 화재발생지점의 명확화 및 건축물 외부에도 화재층 표시를 통해 소방력 공급시간을 단축할 필요가 있다. 둘째, 신호통신은 무선통신보조설비의 설치대상을 강화하고, 중계기 설치를 보완하며, 다중통신망을 구성할 것을 제안하였다. 셋째, 행동결정은 인접건축물에서 도하의 방법으로 진압대원 및 소방장비를 공급하고, 일정 층마다 파괴가 용이한 유리창을 설치하며 식별표시도 필요하다. 넷째, 현장대응은 활강과 수직구조기법을 적용하여 소방장비의 공급 및 진압대원의 진입을 돕고 드론을 이용하여 소방장비를 공급한다. 마지막으로 충분한 소화액 제공은 헬리콥터와 인접한 건축물을 이용하여 소방용수를 공급한다.

• 접착 및 계면
• /
• 제9권2호
• /
• pp.24-31
• /
• 2008

본 연구에서는 EVA 에멀젼에 내수성 및 기계적 특성을 향상시키기 위하여 금속 이온 가교제인 calcium hydroxide 및 magnesium carbonate를 사용하여 이온성 가교결합을 도입하였다. EVA 에멀젼 필름의 가교밀도, 열적특성, 표면자유에너지 그리고 인장강도, 파단신율 및 인열강도 특성을 고찰하였다. 금속 이온 가교제 양이 증가함에 따라 EVA 에멀젼의 가교밀도는 증가하였고, 이에 내수성과 $T_g$ 값도 증가하였다. 그러나 EVA 에멀젼 필름의 표면에너지 및 기계적 특성들은 다소 다른 거동을 보였다. Calcium hydroxide 0.4% 그리고 magnesium carbonate 0.5%를 첨가한 경우가 EVA 에멀젼에 강한 이온성 가교결합이 형성되어 가장 높은 표면 자유에너지 값과 인장강도 및 인열강도를 보였다. 그러므로 본 연구에서 calcium hydroxide 및 magnesium carbonate와 같은 금속 이온 가교제가 EVA 에멀젼의 내수성과 기계적 물성을 향상시킴을 확인하였다.

• The International Journal of Costume Culture
• /
• 제5권1호
• /
• pp.1-13
• /
• 2002

The purpose of this study is to illuminate the relations between Pop Art and pop music, which formed a serious coupling loop in an identical cultural background. Also this study intends to set up a position of visualized sexual identity as it Points out the conceptional characteristics of glam, a subculture outside mainstream, which includes the matters of sexual minorities such as homosexuality and bisexuality under the influence of the aesthetic and philosophical composition by Andy Warhol. In conjunction herewith, we explore the visual representation of glam style focusing on the influence of Warhol. The classification and explanation about the visual representation of glam style under the influence of Warhol are practised by distinguishing as denotative representation and connotative representation. For the denotative representation shown in the glum style, first, the discordant images were put together by bricolage, then adapted into the new dramatic symbol of youth. Second, through a visually androgynous style a subversion of sex for symbols of sexuality and gender was represented. Third, the factitiveness as a weird display and fallacy is shown from boisterous make-up and unisex sかling in theatricality and put-ons, featuring artificiality, assemblage and unnaturality. And the connaotative representation shown in glum inglam style, first, glam style implies its experimental nature which attempts to break down boundaries between masculinity and femininity, homosexuality and heterosex-uality. Second, the bricolage in sequin and other discordant elements have connotative meanings as sensuality and excessiveness. Third, mixing various style as sexual play shows ironic visual images, in accordance with Superior Theory and Discord Theory.

• Near Infrared Analysis
• /
• 제1권2호
• /
• pp.21-27
• /
• 2000

Temperature-dependent changes in near-infrared (NIR) spectra have been measured for oleic acid, and nonanoic acid in the pure liquid state. Particular attention has been paid to the 5400-4800 cm$\^$-1/ region where a number of combination bands appear. The NIR spectra of oleic acid show that a band at 5303 cm$\^$-1/ increases with temperature while that at 5270 cm/sup-1/ decreases. It ha been found from their second derivative spectra that these spectral changes take place stepwisely with two break points at 30 and 53$\^{C}$, which correspond to the phase transition temperatures oleic acid reported previously. Principle component analysis (PCA) has been carried out for the NIR spectra of oleic acid in the 5400-4800 cm$\^$-1/ region measured over a temperature range of 15-80$\^{C}$. core plots of the first and second principal components (PCs) show that the NIR spectra are classified into three groups; the spectra measured in the temperature range of 15-30$\^{C}$, those in the range of 31-53$\^{C}$, and those in the range of 54-80$\^{C}$. These temperature ranges correspond to those for quasi-smectic liquid crystal, disordered liquid crystal, and isotropic liquid of oleic acid in the pure liquid state. In other words, PCA provides unambiguous evidence for the phase transitions. similar studies have been carried out for petroselinic acid and nonanoic acid in the pure liquid states, but they do not show any evidence for phase transitions.

• 한국작물학회지
• /
• 제50권6호
• /
• pp.442-446
• /
• 2005

관능특성이 우수한 밀가루의 제품생산 및 밀 품종 개량을 위한 기초자료를 얻고자 국산 그루밀 원맥을 Buhler test mill로 제분하고, 각 제분부위별로 휘발성 향기성분을 검토하였다. 1. 제분부위에 따른 밀의 휘발성 향기성분은 배유층인 $B_1,\;B_2,\;R_1$ 및 $R_2$층과 바깥층인 겨층과 배아간에 정성적인 차이는 없었으나 정량적인 차이는 있었다. 2. 겨층 및 배아층은 배유층에 비하여 m-xylene, n-butanol의 조성이 매우 높았다. 3. 밀에서 냄새의 지표화합물인 $C_6-aldehyde$류와 $C_{6-8}-alcohol$류의 조성은 제분부위에 따라 차이가 있었으며, 배유층 내부인 $B_1,\;B_2,\;R_1$층보다 바깥층인 $R_2$층에서 조성이 높았다. 따라서 $R_2$층이 $B_1,\;B_2,\;R_1$층에 비하여 관능적으로 보다 우수할 것으로 추정되었다.