• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.367-371
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• 2001

Lithium inserted into artificial carbon has been synthesized as a function of the Li concentration. The characteristics of these prepared compounds were determined from the studies using X-ray diffraction(XRD), solid nuclear magnetic resonance (NM R) spectrophotometric and differential scanning calorimeter(DSC) analysis. X-ray diffraction showed that lower stage intercalation compounds were formed with increasing Li concentration. In the case of the AG3, most compounds formed were of the stage 1 structure. Pure stage 1 structural defects of artificial graphite were not observed. 7Li-NMR data showed that bands are shifted toward higher frequencies with increasing lithium concentration; this is because non-occupied electron shells of Li increased in charge carrier density. Line widths of the Li inserted carbon compounds decreased slowly because of nonhomogeneous local magnetic order and the random electron spin direction for located Li between graphene layers. The enthalpy and entropy changes of the compounds can be obtained from the differential scanning calorimetric analysis results. From these results, it was found that exothermic and endothermic reactions of lithium inserted into artificial carbon are related to the thermal stability of lithium between artificial carbon graphene layers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.819-821
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• 2001

This paper describes a characteristics of MFL according to the position of Hall sensor Magnetic Flux Leakage(MFL) Method is used to detect surface defect in ferromagnetic plate. A plate has a surface defect and magnetizing equipment are producted to perform Non-Destructive Testing(NDT) using MFL. The SM 45C carbon steel plate is adopted to this experiment. there is a artifical defect with a twice of thickness and a half of depth of plate. Magnetizing equipment is composed of yoke made by layer-built of silicon sheet steel, NdFeB magnetic and iron brushes. Detecting defect is performed by MFL NDT using Hall sensor. It is shown that magnetic flux detected by Hall sensor is affected according to the position of Hall sensor through MFL experiment and numerical analysis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.841-844
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• 2002

The vertical impact crusher is the machine which could produce artifical sand similar to natural aggregates in the site of guarry and pits. FEM was used to analyse the stress and strength of the machine at high rotational speed. The test specimen was made from the same material as the shaft and tension tests were conducted. The shaft under extreme conditions was analysed to determine maximum stress level and its location from the results. The maximum level of stress and its location could be predicted.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 춘계학술대회
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• pp.211-220
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• 2004

The vertical impact crusher is the machine which could produce artifical sand similar to natural aggregates in the site of guarry and pits. FEM was used to analyse the stress and strength of the machine at high rotational speed. The test specimen was made from the same material as the shaft and tension tests were conducted. The Shaft under extreme conditions was analysed to determine maximum stress level and its location from the results. The maximum level of stress and its location could be predicted.

• 비파괴검사학회지
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• 제27권5호
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• pp.409-416
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• 2007

최근 탄소섬유, 유리섬유 등 보강재의 사용이 증가함에 따라 내구성저하의 원인이 될 수 있는 콘크리트와 보강재 사이의 박리탐사 필요성이 대두된다. 본 연구에서는 중심주파수가 15 GHz이고, 대역폭이 10 GHz인 horn antenna 를 이용하여, 탄소섬유 및 유리섬유시트 보강 콘크리트 박리를 탐사하는 실험을 실시하였다. 실험에 사용된 시편은 길이 $600\;{\times}$ 폭 $600\;{\times}$ 두께 100 mm 의 크기를 가지며, 그 표면에 1.5 mm 두께의 탄소섬유 유리섬유를 에폭시로 부착하였다. 또한, 시편의 중앙에 길이 $50\;mm\;{\times}$ 폭 50 mm 크기의 박리를 콘크리트 표면 밑에 각각 두께 2, 4, 6 mm로 만들어 매립하였고, 콘크리트 표면 위에 2 mm 두께로 만들어, 인공박리를 제작하였다. 제작된 시편은 섬유의 종류에 따라 각각 4종류씩 총 8개의 시편이 제작되었다. 실험 결과는 그래프의 면적차이를 이용한 결과처리방법으로 처리하였고, 실험 결과 탄소섬유와 유리섬유시편에 매립된 인공 박리를 찾아내어, 향후 콘크리트/보강재 박리탐사시스템 개발에 도움이 되는 자료를 제공할 것이다.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 1997년도 Progress and Future Development of Sericultural Science and Technology 40th Anniversary Commemoration Symposium
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• pp.23-49
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• 1997

This is a progress report of rice biotechnology including development of gene transformation system, gene cloning and molecular mapping in rice. The scope of the research was focused on the connection between conventional breeding and biotech-researches. Plant transformation via Agrobacterium or particle bombardment was developed to introduce one or several genes to recommended rice cultivars. Two chimeric genes containing a maize ribosome inactivating protein gene (RIP) and a gerbicide resistant gene (bar) were introduced to Nipponbare, a Japonica cultivar, and transmitted to Korean cultivars. The homozygous progenies of herbicide resistant transgenic plant showed good fertility and agronomic characters. To explore the genetic resourses in rice, over 8,000 cDNA clones from immature rice seed have been isolated and sequenced. About 13% of clones were identified as enzymes related to metabolic pathway. Among them, twenty clones have high homology with genes encoding enzymes in the photorespiratory carbon cycle reaction. Up to now about 100 clones were fully sequenced and registered at EMBL and GenBank. For the mapping of quantitative tarits loci (QTL) and eternal recombinant inbred population with 164 F13 lines (MGRI) was developed from a cross between Milyang 23 and Gihobyeo, Korean rice cultivars. After construction of fully saturated RFLP and AFLP map, quantitative traits using MGRI population were analyzed and integrated into the molecular map. Eighty seven loci were determined with 27 QTL characters including yield and yield components on rice chromosomes. Map based cloning was also tried to isolate semi-dwarf (sd-1) gene in rice. A DNA probe, RG 109, the most tightly linked to sd-1 gene was used to screen from bacterial artifical chromosome (BAC) libraries and five over lapping clones presumably containing sd-1 gene were isolated. Rice genetic database including results of biotech reasearch and classical genetics is provided at Korea Rice Genome Server which is accessible with world wide web (www) browser. The server provides rice cDNA sequences and map informations linked with phenotypic images.