• 제목/요약/키워드: resistance-area product

검색결과 40건 처리시간 0.032초

순환자원 활용 지반차수재의 노후저수지 보강 적용사례 및 성능검증에 관한 연구 (A Study on Application and Performance Verification of Aged Reservoir Reinforcing Method using Ground Injection Material of Utilizing Circulation Resources.)

  • 박성훈;서세관;송상훤
    • 한국농촌건축학회논문집
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    • 제22권3호
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    • pp.17-24
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    • 2020
  • Reservoirs, which make up most of South Korea's reservoirs, are located in rural areas. In the case of rural reservoirs, about 75% have been reported over 50 years old aged reservoirs constructed before the 1960s. Reservoirs are important facilities that store and supply water necessary for daily life. However, if it is destroyed, the reservoir can cause a lot of damage, so continuous management is necessary. As a method for strengthening old reservoirs, a method using cement has been widely applied. However, OPC is a product that uses a lot of carbon dioxide and natural resources. Therefore, the amount of cement should be reduced. Against this background, in this study, the ground injection material of utilizing circulation resources was applied to the site. Applied reservoirs have been around for 75 years and leaks have occurred in some sections. The application method was constructed in two rows, up to a depth of 12m. After reinforcement, the electrical resistivity test was conducted three times. As a result, similar resistance was shown at 1 month after construction. And after 6 months, the saturation area decreased. And the performance after reinforcing the aged reservoir was examined. As a result of the review, this study confirmed that the applicability was equivalent to that of OPC, and the excellent performance of reinforcing the aged reservoir was shown.

청정닭고기와 일반닭고기의 영양성분에 대한 연구 (Studies on Nutrient Components between the Chungjung Chicken Meats and General Chicken Meats)

  • 양희태;최화정
    • 한국식품영양학회지
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    • 제16권3호
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    • pp.187-191
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    • 2003
  • 지질은 인간내에서 에너지원으로 또 여러 가지 필수 영양소의 원천으로 가장 중요한 영양소 중의 하나이며, 특히 식품에 특유한 풍미를 부여 할 뿐만 아니라, 저장 중에도 중요한 영향을 미치는 영양소이다$^{19}$ ). 그러나 현재 동맥경화나 고혈압 등의 원인으로 지질의 질이 상당히 문제가 되고 있는데 이러한 지질의 물리적, 화학적 성질을 결정지어 주는 중요한 성분은 지방산이다$^{20}$ ). 본 연구는 양질의 사료와 미생물 생균제(INPEX), 액젓을 추출하고 남은 부산물을 먹인 청정닭고기와 국내에서 현재 유통되고 있는 일반닭고기와 조단백질, 조지방, 칼슘 함량 및 지방산 조성을 분석하였다. 조단백질과 칼슘은 청정닭고기가 높았으며 조지방 함량은 일반 닭고기가 높았다. 그러나 지방산 조성에 청정닭고기는 불포화지방산의 비율이 높았으며 이 중에서도 n-3계열 지방산의 함량이 높았고 특히 뇌발달에 필수적인 영양소인 고도불포화지방산인 DHA의 함량이 월등히 높았다. 또한 간접적으로는 단위동물들의 대사적 이향율 즉, 양질의 사료와 미생물 생균제(INPEX), 액젓을 추출하고 남은 부산물중에 함유된 linolenic acid를 ecosapentaenoic acid(EPA)와 decosahexanoic acid(DHA)등의 성분을 청정닭이 보유하고 있음을 알 수 있었다. 본 자료에는 없지만 이러한 청정닭고기는 육질이 부드럽고 맛있으며 고기가 쪽득거리고 씹는 맛(조직감)이 뛰어날 뿐만 아니라 특히 일반닭고기 특유의 비린내가 없고, 지방이 적어 국물이 담백한 관능 결과도 나타내었다.

PCITS에 의해 소손된 강이음쇠형 CSST의 특성 해석에 관한 연구 (A Study on the Properties Analysis of an Iron Fittings Type CSST Damaged by the PCITS)

  • 이장우;최충석
    • 한국화재소방학회논문지
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    • 제30권4호
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    • pp.121-127
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    • 2016
  • 본 논문에서는 대전류공급장치(PCITS)에 의해 소손된 강이음쇠형(iron fittings type) 금속플렉시블호스(CSST)의 구조 및 전기적 특성을 해석하였다. CSST는 보호 피막, 튜브, 너트, 클램프 링, 플레어 캡, 소켓, 볼 밸브 등으로 구성되어 있다. CSST의 내전압 평가는 전기 충전부와 비충전부 사이에 교류 전압 220 V를 1분간 인가하여 견뎌야 한다. 직류 500 V에 의한 절연 성능의 평가는 온도 상승 시험 전에 $1M{\Omega}$ 이상, 시험이 끝난 후에는 $0.3M{\Omega}$ 이상을 요구한다. 정상 제품의 평균 저항은 $11.5m{\Omega}$이었으나 PCITS로 130 A를 흘려 소손된 제품의 평균 저항 $11.50m{\Omega}$이었다. 또한 130 A가 약 10 s 흘렀을 때 튜브의 보호 피막이 일부 용융되었고, 검정색의 연기가 발생하였다. 60 s 경과되면 튜브의 대부분이 적색으로 발열되며, 전류가 120 s 흘렀을 때는 적열 범위가 넓어졌다. 95%의 신뢰 구간(CI)의 검증에서 P 값은 0.019로 정규 분포를 갖지 못하였으나 Anderson-Darling (AD) 통계량은 0.896, 표준 편차는 0.5573 등으로 양호한 특성을 나타냈다.

Perspective of breaking stagnation of soybean yield under monsoon climate

  • Shiraiwa, Tatsuhiko
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.8-9
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    • 2017
  • Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

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Magnetic Tunnel Junctions with AlN and AlO Barriers

  • Yoon, Tae-Sick;Yoshimura, Satoru;Tsunoda, Masakiyo;Takahashi, Migaku;Park, Bum-Chan;Lee, Young-Woo;Li, Ying;Kim, Chong-Oh
    • Journal of Magnetics
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    • 제9권1호
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    • pp.17-22
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    • 2004
  • We studied the magnetotransport properties of tunnel junctions with AlO and AlN barriers fabricated using microwave-excited plasma. The plasma nitridation process provided wider controllability than the plasma oxidization for the formation of MTJs with ultra-thin insulating layer, because of the slow nitriding rate of metal Al layers, comparing with the oxidizing rate of them. High tunnel magnetoresistance (TMR) ratios of 49 and 44% with respective resistance-area product $(R{\times}A) of 3 {\times} 10^4 and 6 {\times} 10^3 {\Omega}{\mu}m^2$ were obtained in the Co-Fe/Al-N/Co-Fe MTJs. We conclude that AlN is a hopeful barrier material to realize MTJs with high TMR ratio and low $R{\times}A$ for high performance MRAM cells. In addition, in order to clarify the annealing temperature dependence of TMR, the local transport properties were measured for Ta $50{\AA} /Cu 200 {\AA}/Ta 50 {\AA}/Ni_{76}Fe_{24} 20 {\AA}/Cu 50 {\AA}/Mn_{75}Ir_{25} 100 {\AA}/Co_{71}Fe_{29} 40 {\AA}/Al-O$ junction with $d_{Al}= 8 {\AA} and P_{O2}{\times}t_{0X}/ = 8.4 {\times} 10^4$ at various temperatures. The current histogram statistically calculated from the electrical current image was well in accord with the fitting result considering the Gaussian distribution and Fowler-Nordheim equation. After annealing at $340^{\circ}C$, where the TMR ratio of the corresponding MTJ had the maximum value of 44%, the average barrier height increased to 1.12 eV and its standard deviation decreased to 0.1 eV. The increase of TMR ratio after annealing could be well explained by the enhancement of the average barrier height and the reduction of its fluctuation.

배유 특이 프로모터에 의해 유도된 GUS 유전자의 형질전환 담배 내에서의 발현 및 유전 양상 (Expression and Inheritance Patterns of Gus Gene Driven by an Endosperm-Specific Promoter in Transgenic Tobacco)

  • 박영두;김형석
    • 원예과학기술지
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    • 제18권5호
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    • pp.594-598
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    • 2000
  • 본 실험은 형질전환 담배내에서의 배유 특이 promoter에 의한 gus 유전자의 조직 특이적 발현 여부와 전이유전자의 후대로의 유전 양상을 확인하고자 수행하였다. 배유 특이 promoter에 의해 유도되는 gus 유전자(Z4pro-gus)와 kanamycin 저항성유전자를 운반하는 BV3 construct를 A. tumerfaciens을 이용하여 담배 형질전환체를 유기시켰다. 형질전환체 중에서 8개체를 선발하여 nptII primer를 이용하여 PCR을 실시한 결과 8개체 모두에서 700bp의 PCR 산물을 얻을 수 있었다. Promoter에 따른 유전자의 발현양상을 알아보기 위하여 Z4pro-gus가 전이된 형질전환체의 잎과 CaMV35S와 gus 유전자(35Spro-gus)로 구성된 pBI121 construct를 전이시킨 형질전환체의 잎으로부터의 발색정도를 비교하였다. 그 결과 Z4pro-gus가 전이된 형질전환체의 경우 잎에서 매우 부분적으로 극소량 발색되었으나 35Spro-gus가 전이된 형질전환체의 잎에서는 상대적으로 많은 양의 발색정도를 보여 promoter에 따른 발현정도의 차이를 보였다. 보다 명확한 Z4 promoter의 조직 특이 발현 양상을 확인하기 위하여 Z4pro-gus로 형질전환시킨 $T_0$ 식물체를 자가수분하여 얻은 $R_1$ 종자와 35Spro-gus를 형질전환시켜 같은 방법으로 얻은 $R_1$ 종자를 histochemical assay하였다. 그 결과 35Spro-gus로 형질전환된 담배 종자는 절단면 전체에서 gus 유전자가 발현되어 배유뿐만 아니라 종자 내 다른 조직에서도 발색되는 양상을 나타내었으나 Z4pro-gus를 형질전환 시켜 얻은 종자의 경우는 배유 부분만이 조직 특이적으로 파랗게 발색되었고 배 또는 그 이외의 조직에서는 gus 발색이 전혀 관찰되지 않았다. Kanamycin 저항성검정을 실시한 결과 모든 계통에서 전이유전자가 후대로 안정적으로 전이됨을 확인할 수 있었다.

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p-i-n 구조의 InSb 웨이퍼를 이용한 적외선 광다이오드의 제조 및 그 특성 (Fabrication and Characteristics of Infrared Photodiode Using Insb Wafer with p-i-n Structure)

  • 조준영;김종석;손승현;이종현;최시영
    • 센서학회지
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    • 제8권3호
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    • pp.239-246
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    • 1999
  • MOCVD로 성장된 p-i-n 구조의 InSb 웨이퍼를 이용하여 $3{\sim}5\;{\mu}m$ 영역의 적외선을 감지할 수 는 고감도 광기전력 형태의 적외선 광다이오드를 제조하였다. InSb는 녹는점과 표면원자들의 증발온도가 낮기 때문에 광다이오드의 접합계면과 표면의 절연보호막으로 $SiO_2$ 박막을 원격 PECVD를 이용하여 성장시켰다. 광다이오드의 저항성 접촉을 위해 In을 증착하였고 77K의 암상태에서 전류-전압 특성을 조사하였다. 영전위 저항과 수광면적의 적($R_0A$)이 $1.56{\times}10^6\;{\Omega}{\cdot}cm^2$의 높은 값을 가졌는데 이는 BLIP 조건을 만족하는 높은 값이었다. InSb 광다이오드에 적외선을 입사 했을때 $10^{11}\;cm{\cdot}Hz^{1/2}{\cdot}W^{-1}$의 매우 높은 정규화된 검지도를 나타내었다. 높은 양자효율과 검지도로 인해 제조된 InSb 적외선 단위 셀을 적외선 array에 그 적용이 가능할 것으로 보인다.

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Integrated RT-PCR Microdevice with an Immunochromatographic Strip for Colorimetric Influenza H1N1 virus detection

  • Heo, Hyun Young;Kim, Yong Tae;Chen, Yuchao;Choi, Jong Young;Seo, Tae Seok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.273-273
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    • 2013
  • Recently, Point-of-care (POC) testing microdevices enable to do the patient monitoring, drug screening, pathogen detection in the outside of hospital. Immunochromatographic strip (ICS) is one of the diagnostic technologies which are widely applied to POC detection. Relatively low cost, simplicity to use, easy interpretations of the diagnostic results and high stability under any circumstances are representative advantages of POC diagnosis. It would provide colorimetric results more conveniently, if the genetic analysis microsystem incorporates the ICS as a detector part. In this work, we develop a reverse transcriptase-polymerase chain reaction (RT-PCR) microfluidic device integrated with a ROSGENE strip for colorimetric influenza H1N1 virus detection. The integrated RT-PCR- ROSGENE device is consist of four functional units which are a pneumatic micropump for sample loading, 2 ${\mu}L$ volume RT-PCR chamber for target gene amplification, a resistance temperature detector (RTD) electrode for temperature control, and a ROSGENE strip for target gene detection. The device was fabricated by combining four layers: First wafer is for RTD microfabrication, the second wafer is for PCR chamber at the bottom and micropump channel on the top, the third is the monolithic PDMS, and the fourth is the manifold for micropump operation. The RT-PCR was performed with subtype specific forward and reverse primers which were labeled with Texas-red, serving as a fluorescent hapten. A biotin-dUTP was used to insert biotin moieties in the PCR amplicons, during the RT-PCR. The RT-PCR amplicons were loaded in the sample application area, and they were conjugated with Au NP-labeled hapten-antibody. The test band embedded with streptavidins captures the biotin labeled amplicons and we can see violet colorimetric signals if the target gene was amplified with the control line. The off-chip RT-PCR amplicons of the influenza H1N1 virus were analyzed with a ROSGENE strip in comparison with an agarose gel electrophoresis. The intensities of test line was proportional to the template quantity and the detection sensitivity of the strip was better than that of the agarose gel. The test band of the ROSGENE strip could be observed with only 10 copies of a RNA template by the naked eyes. For the on-chip RT-PCR-ROSGENE experiments, a RT-PCR cocktail was injected into the chamber from the inlet reservoir to the waste outlet by the micro-pump actuation. After filling without bubbles inside the chamber, a RT-PCR thermal cycling was executed for 2 hours with all the microvalves closed to isolate the PCR chamber. After thermal cycling, the RT-PCR product was delivered to the attached ROSGENE strip through the outlet reservoir. After dropping 40 ${\mu}L$ of an eluant buffer at the end of the strip, the violet test line was detected as a H1N1 virus indicator, while the negative experiment only revealed a control line and while the positive experiment a control and a test line was appeared.

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고덕원 국보 동조아미타여래좌상의 표면에 생성한 부식생성물의 해석 (Analysis Corrosion Products Formed on the Great Buddha Image of Kotokuin Temple in Kamakura)

  • 송전사랑;청목번부;강대일
    • 보존과학연구
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    • 통권17호
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    • pp.161-182
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    • 1996
  • 최근 환경 오염의 영향으로 문화재가 급속히 손상되고 있다. 이에 일본 동경국립문화재연구소에서는 1992년부터 일본 겸창시의 고덕원, 귀원원, 학강팔번궁, 도근현의 일어기신사, 내량시의 동대사 등에 환경 오염 관측 스테이션을 설치하여 조사하고 있다. 본고는 1996년 3월 일본 동경국립문화재연구소에서 발행된 보존과학 제35호에 실린 송전사랑, 청목번부씨의 “고덕원 국보 동조아미타여래좌상의 표면에 생성한 부식생성물의 해석”논문을 저자의 호의에 의해 번역하였다.

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CoFe/NiFeSiB/CoFe 자유층을 갖는 이중장벽 자기터널접합의 바이어스전압 의존특성 (Bias Voltage Dependence of Magnetic Tunnel Junctions Comprising Double Barriers and CoFe/NiFeSiB/CoFe Free Layer)

  • 이선영;이장로
    • 한국자기학회지
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    • 제17권3호
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    • pp.120-123
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    • 2007
  • 이 연구에서는 Ta 45/Ru 9.5/IrMn 10/CoFe $3/AlO_x$/자유층/$AlO_x$/CoFe 7/IrMn 10/Ru 60(nm) 구조를 갖는 이중장벽 자기터널접합(double-barrier magnetic tunnel junction: DMTJ)를 다루었다. 자유층은 $Ni_{16}Fe_{62}Si_8B_{14}\;7nm$, $Co_{90}Fe_{10}(fcc)$ 7 nm 및 $CoFet_1$/NiFeSiB $t_2$/CoFe $t_1$으로 구성하였으며 두께 $t_1,\;t_2$는 변화시켰다. 즉 TMR비와 RA를 개선하기 위하여 부분적으로 CoFe층을 대체할 수 있는 비정질 NiFeSiB층이 혼합된 자유층 CoFe/NiFeSiB/CoFe을 갖는 DMTJ를 연구하였다. NiFeSiB($t_1=0,\;t_2=7$)만의 자유층을 갖는 DMTJ는 터널자기저항(TMR)비 28%, 면적-저항곱(RA) $86k{\Omega}{\mu}m^2$, 보자력($H_c$) 11 Oe 및 층간 결합장($H_i$) 20 Oe를 나타내었다. $t_1=1.5,\;t_2=4$인 경우의 하이브리드 DMTJ는 TMR비 30%, RA $68k{\Omega}{\mu}m^2$$H_c\;11\;Oe$를 가졌으나 $H_i$는 37 Oe로 증가하였다. 원자현미경(AFM)과 투과전자현미경(TEM)측정을 통하여 NiFeSiB층 두께가 감소하면 $H_i$가 증가하는 것을 확인하였다. 비정질 NiFeSiB층이 두꺼워지면 보통 계면의 기복을 유도하는 원주형성장(columnar growth)를 지연시키는데 유효하였다. 그러나 NiFeSiB층이 얇으면 표면거칠기는 증가하고 전자기적 Neel 결합 때문에 Hi는 커졌다.