• Title/Summary/Keyword: Resistance-area product

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

  • Park, Seong-hun;Seo, Se-Gwan;Song, Sang-Hwon
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.3
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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.

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

  • 양희태;최화정
    • The Korean Journal of Food And Nutrition
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    • v.16 no.3
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    • pp.187-191
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    • 2003
  • It was performed to find out difference of the nutritional contents between chungjung chicken meats grown chemicals free and general chicken meats. The chungjung chicken was eat and given feeds of good quality mixed living microbial agent, power of ginseng leaves and by-product of extract liquefied sea foods from fishes producted clean area of the Western Sea, including plentiful calciums, amino acids, docosahexanoic acid(DHA) etc. Addition of they improved chungjung chicken yields and meat quality compared to general chicken given feeds mixed antibiotic etc. Also, chungjung chickens eaten miced type develop resistance to in disease. There were significant trend in crude proteins, calciums, crude lipids contents, and unsaturated fatty acids between the chungjung chicken meats and the general chicken meats. The crude proteins and calciums contents were higher in the chungjung chicken meats than the general chicken meats, but the crude lipids contents were higher in the general chicken meats than that. Also, contents of the n6 fatty acids and n3 fatty acids in chungjung meats were higher than that. Especially, contents of DHA in the chungjung chicken meats were detected higher than the general chicken meats. Therefore, the results from this experiments will provide a information for the nutritional knowledge of the 'white meats', especially the clean chicken meats.

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

  • Lee, Jang-Woo;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.30 no.4
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    • pp.121-127
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    • 2016
  • This study analyzed the structural and electrical characteristics of an iron fittings type Corrugated Stainless Steel Tubing (CSST) damaged by the Primary Current Injection Test System (PCITS). CSST consists of cladding, tube, nuts, clamp ring, flare cap, socket, and ball valve. For an evaluation of the dielectric withstand voltage, the area between the live part and non-live part of the CCST shall withstand a voltage of 220 V AC for one minute. For an evaluation of the insulation performance by 500 V DC, it is required that the insulation exceed more than $1M{\Omega}$ before the temperature rise test, $0.3M{\Omega}$ after the test. Although the average resistance of the product was $11.5m{\Omega}$, that of the product damaged at a current of 130 A by the PCITS was $11.50m{\Omega}$. Furthermore, parts of the cladding were melted and black smoke appeared when a current of 130 A applied for 10 s. After 60 s, most parts were heated and turned red. At 120 s, the parts that turned red had widened. Although it did not form a normal distribution because the P value was 0.019 with a confidential interval of 95%, it revealed outstanding characteristics with an AD (Anderson-Darling) value of 0.896 and a standard deviation of 0.5573.

Perspective of breaking stagnation of soybean yield under monsoon climate

  • Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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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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    • v.9 no.1
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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.

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

  • Park, Young Doo;Kim, Hyoung Seok
    • Horticultural Science & Technology
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    • v.18 no.5
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    • pp.594-598
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    • 2000
  • This study was carried out to investigate the tissue-specific expression of ${\beta}$-glucuronidase (gus) gene driven by endosperm-specific promoter (Z4 promoter) in the transgenic tobacco and to find out inheritance pattern of transgene to the next generation. Tobacco (Nicotiana tabaccum cv. Havana SR1) was transformed with Agrobacterium tumerfaciens LBA4404 harboring BV3 construct containing gus gene driven by Z4 promoter and a kanamycin resistant gene. Seven hundred bp PCR products, indicating the presence of npt II gene, were found in the all eight transformants by PCR analysis using nptII primers. To study the expression pattern of the two different kind of promoters, leaf disks of the Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. As a result, leaf disks of Z4pro-gus-transformed plants showed very weak and partial positive gus activity. In contrast, leaf disks of 35Spro-gus-transformed plants showed relatively strong positive gus activity. To investigate the expressed position of Z4 promoter, seeds from Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. Z4pro-gus-transformed seeds showed positive gus activity restricted to the endosperm. However, the blue-colored product in 35Spro-gus-transformed seeds was observed in all the area including endosperm. Kanamycin resistance assay showed that transgenes were stably inherited to next generation in all lines.

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

  • Cho, Jun-Young;Kim, Jong-Seok;Son, Seung-Hyun;Lee, Jong-Hyun;Choi, Sie-Young
    • Journal of Sensor Science and Technology
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    • v.8 no.3
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    • pp.239-246
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    • 1999
  • A highly sensitive photovoltaic infrared photodiode was fabricated for detecting infrared light in $3{\sim}5\;{\mu}m$ wavelength range on InSb wafer with p-i-n structure grown by MOCVD. Silicon dioxide($SiO_2$) insulating films for the junction interface and surface of photodiode were prepared using RPCVD because InSb has low melting point and evaporation temperature. After formation of In ohmic contacts by thermal evaporation, the electrical properties of the photodiode were characterized in dark state at 77K. A product of zero-bias resistance and area($R_0A$) showed $1.56{\times}10^6\;{\Omega}{\cdot}cm^2$ that satisfied BLIP(background limited infrared photodetector) condition. When the photodiode was tested under infrared light, the normalized detectivity of about $10^{11}\;cm{\cdot}Hz^{1/2}{\cdot}W^{-1}$ was obtained. we successfully fabricated a unit cell with InSb IR array with good quantum efficiency and high detectivity.

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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
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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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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Analysis Corrosion Products Formed on the Great Buddha Image of Kotokuin Temple in Kamakura (고덕원 국보 동조아미타여래좌상의 표면에 생성한 부식생성물의 해석)

  • Matsuda Shiro;Aoki Shigeo;Kang, Dai-il
    • 보존과학연구
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    • s.17
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    • pp.161-182
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    • 1996
  • In natural atmosphere, copper and copper alloy have been used to make buddha statues and ornaments of historic buildings since the abovementioned metals have corrosion resistance in some extent, and the patinaformed on the surface of the metals has provided the people aesthetic satisfaction with its beauty. But in atmosphere polluted by $SO_x$and $NO_x$, the patina layer does not work as a protective film, and it allows damages of the metal. Since 1992, Tokyo National Research Institute of Cultural Properties(TNRICP)has conducted studies on the influence of atmospheric pollution on metal cultural property held under open air. The Great Buddha Image which is located in Kamakura about 50km west from Tokyo, has been selected as one of the objects to study because it is made by copper alloy and it has stood exposed in the air for about a few hundreds years. Furthermore it is also the reason to study on it that there are many cultural properties in the surroundings of it. We have analysed the components and the structure of the corrosion products formed on the surface of the Buddha, have carried out exposure tests using the alloy samples which have simulated the components of the Great Image, and have observed climated and polluted air in order to discuss the relation between corrosion of metals in open air and conditions of the atmosphere. In this paper, the authors have described the components and the structure of the corrosion product formed on the surface of the Great Image by means of X-ray fluorescence spectroscopy and X-ray diffraction. The conclusions are as follows. (1) Sulfate patina composed mainly with brochantite were detected on the all sides of the Image and the amount of the patina is found more on the back of the Image facing to north. (2) Antlerite were detected on the back and a park of the left side facing to west, and formation of it was considered to have close relation with malignant atmosphere. (3) A big amount of chloride patina which mainly composed of atacamite were observed on the front facing to south. (4) Carbonate patina mainly composed of malachite were detected on the area where brochantite was often detected as well. It suggested that malachite had been transformed into brochantite by deteriorated atmosphere. (5) On the all sides of the Image, patina were observed together with copper oxides mainly composed of cuprous oxide. It showed that the surface layer of the Image consists of two layers : inner layer of oxide and outer layer of patina. (6) Corrosion products of lead which was a component of copperalloy were detected on the all sides : the main lead product found on the front was chlorophosphate whereas the one on the back was sulfate.

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

  • Lee, S.Y.;Rhee, J.R.
    • Journal of the Korean Magnetics Society
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    • v.17 no.3
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    • pp.120-123
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    • 2007
  • The typical double-barrier magnetic tunnel junction (DMTJ) structure examined in this paper consists of a Ta 45/Ru 9.5/IrMn 10/CoFe7/$AlO_x$/free layer/AlO/CoFe 7/IrMn 10/Ru 60 (nm). The free layer consists of an $Ni_{16}Fe_{62}Si_8B_{14}$ 7 nm, $Co_{90}Fe_{10}$ (fcc) 7 nm, or CoFe $t_1$/NiFeSiB $t_2$/CoFe $t_1$ layer in which the thicknesses $t_1$ and $t_2$ are varied. The DMTJ with an NiFeSiB-free layer had a tunneling magnetoresistance (TMR) of 28%, an area-resistance product (RA) of $86\;k{\Omega}{\mu}m^2$, a coercivity ($H_c$) of 11 Oe, and an interlayer coupling field ($H_i$) of 20 Oe. To improve the TMR ratio and RA, a DMTJ comprising an amorphous NiFeSiB layer that could partially substitute for the CoFe free layer was investigated. This hybrid DMTJ had a TMR of 30%, an RA of $68\;k{\Omega}{\mu}m^2$, and a of 11 Oe, but an increased of 37 Oe. We confirmed by atomic force microscopy and transmission electron microscopy that increased as the thickness of NiFeSiB decreased. When the amorphous NiFeSiB layer was thick, it was effective in retarding the columnar growth which usually induces a wavy interface. However, if the NiFeSiB layer was thin, the roughness was increased and became large because of the magnetostatic $N{\acute{e}}el$ coupling.