• 한국세라믹학회지
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• 제32권5호
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• pp.587-593
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• 1995

Abnomal grain growth behavior of BaTiO3 ceramics was investigated with addition of seed grains. It was foudn that the nucleation rate of abnormal grain was constant and growth of abnormal grain was linearly increased with sitnering time, regardless of amount of seed grains. These facts were also confirmed by fitting of the volume fraction of abnormal grain vs. sintering time using Avrami type equation (n=4). It was suggested that seed grains did not change the nucleation rate or growth mechanism of abnormal grain but increase the number of abnormal grains at initial stage of sintering and then it led to fine microstructure of BaTiO3 ceramics.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.228-230
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• 2004

Samples of the aluminum alloy 3103 sheets were repeatedly deformed by ECAR up to twelve passes. Shear textures developed after the first passage of ECAR. However, the intensity of shear texture components decreased with increasing number of ECAR passages. Observations by TEM and EBSD revealed that the degree of misorientations within the deformed grains increased with increasing number of ECAR passes. Changes in textures and microstructures were hardly observed during recrystallization anneal. Upon subsequent annealing, the samples deformed by a large number of ECAR passes displayed a continuous grain growth. A higher deformation by ECAR resulted in a slower softening, which reflects the stability of ultra-fine grains against the grain growth.

• 소성∙가공
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• 제16권5호통권95호
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• pp.406-411
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• 2007

The microstructure and the hardness of interstitial free steel processed by equal channel angular pressing (ECAP) was investigated experimentally. ECAP processing of route A and route C was compared with regard to grain refinement by transmission electron micrographs. Micro hardness evolution was correlated with the gram structure produced by ECAP. Especially, the effects of the ECAP processing temperature and the number of processing passes were discussed in terms of grain refinement.

• 한국작물학회지
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• 제47권3호
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• pp.206-210
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• 2002

종실 등의 특성을 기준으로 분류한 7가지 벼 이형주군의 변이와 분리양상은 다음과 같다. 1. Esterase 동위효소 분석에서 장립적미군은 1과 3 esterase isozyme zymogram(EIZ), 장립메성군은 1, 3 및 7 EIZ로 분류할 수 있었다. 2. 극만생 불임군은 EIZ가 1, 2, 1+2, 5, 6, 5+6, 7, 8, 7+8 및 12로 다양하게 분리되었다. 3. EIZ가 1인 장립적미군이 3 EIZ인 장립적미군에 비해 간장이 길고 현미의 장폭비가 낮았다. 4. EIZ가 3인 장립메성군은 1이나 7 EIZ인 장립메성군에 비해 간장이 길고 수장이 짧고 분얼수가 많고 현미의 장폭비가 낮으며 수당 립수가 적었다.

• 한국작물학회지
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• 제38권2호
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• pp.134-138
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• 1993

한국에서 수집된 장, 단입형 적미 각각 4계통과 삼강벼와 섬진벼를 대조품종으로 하여 질소수준을 0, 7.5, 15.0, 22.5kg/10a 등 4수준으로 하여 수량구성 요소와 수량을 조사한 결과를 요약하면 다음과 같다. 1. 적미의 수수와 이삭당 영화수는 질소수준이 0-22.5kg/10a으로 증가함에 따라 대조품종과 같은 경향으로 증가하였다. 2. 장입형 적미의 천입종은 질소 시비량이 증가함에 따라 대체로 감소하는 경향이었던 반면 대조품종인 삼강벼는 증가하였다. 단입형 적미와 대조품종인 섬진벼의 천입중은 질소 시비량 증가에 따른 변화가 없었다. 3. 질소 시비량이 22.5kg/10a까지 증가함에 따라 장입형 적미의 수량은 대체로 증가하는 경향이었으나 단입형 적미는 7.5kg/10a까지는 증가하나 그 이상의 질소 수준에서는 비슷한 수량을 보였다.

• 한국작물학회지
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• 제45권4호
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• pp.237-240
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• 2000

This experiment was conducted to evaluate the effect of split application of nitrogen(N) on development of vascular bundle(VB) and yield components of rice. Two cultivars were used in this study; IR58, an indica type and Shinunbongbyeim a japonica type. The number and total cross sectional area of the VB in the peduncle and leaf blade were more and bigger in N split application than 100 percent basal fertilizer. Nitrogen split application at necknode differentiation stage increased the number and size of the VB. Nitrogen split application resulted in increased panicle number with application of N before transplanting and at tillering stage; increased spikelets number with N application at necknode differentiation stage; and increased spikelet fertility and 1000 grain weight with N application at necknode differentiation and heading stages. Grain yield increased 7-10% in N split as compared to all basal application. The total cross sectional area of VB in peduncle closely correlated with the number of spikelets per panicle. Nitrogen management can have an impact on spikelet differentiation through more and bigger VB and increase grain yield potential.

• 한국작물학회지
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• 제44권1호
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• pp.86-94
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• 1999

A set of rice recombinant inbred lines was developed from a cross between a Tongil type variety, Nonganbyeo, and an indica variety, BG276, by the single seed descent method. The number of the lines in the population was 272. All the agronomic characters studied except ADV (alkali-digestion value) showed continuous variation among the RILs, implying that their inheritance mode should be quantitative. The patterns of the variation in the RILs were either normal or skewed distribution. ADVs of RILs were segregated into two groups with 1:1 ratio, indicating that ADVs in this KIL population might be controlled by one major gene. Transgressive variations were also observed in all characters. Heritability values of the characters varied from 0.488 in brown/rough rice ratio to 0.895 in alkali-digestion value. In the analysis of genotypic and phenotypic correlations, the character of yield was positively correlated with 8 different agronomic characters. The number of panicles per hill was negatively correlated with culm length, panicle length, and number of spikelets per panicle. Grain length was positively correlated with grain width, grain thickness, grain length/width ratio, white belly, ADV, and amylose. However, grain length/width ratio was negatively correlated with grain width. White core was also negatively correlated with white belly and ADV.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.124-124
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• 2022

Wheat (Triticum aestivum L.) is the major staple foods and is in increasing demand in the world. The elevated temperature due to changes in climate and environmental conditions is a major factor affecting wheat development and grain quality. The optimal temperature range for winter wheat is between 15~25℃, it is necessary to study the physiological characteristic of wheat according to the elevated temperature. This study presents the effect of elevated temperature on the yield and quality of two Korean bread wheat (Baekkang and Jokyoung) in a temperature gradient tunnel (TGT). Two bread wheat cultivars were grown in TGT at four different temperature conditions, i.e. TO control (near ambient temperature), T1 control+1℃, T2 control+2℃, T3 control+3℃. The period from sowing to heading stage has accelerated, while the growth properties including culm length, spike length and number of spike, have not changed by elevated temperature. On the contrary, the number of grains per spike and grain yield was reduced under T3 condition compared with that of control condition. In addition, the. The grain filling rate and grain maturity also accelerated by elevated temperature (T3). The elevating temperature has led to increasing protein and gluten contents, whereas causing reduction of total starch contents. These results are consistent with reduced expression of starch synthesis genes and increased gliadin synthesis or gluten metabolism genes during late grain filling period. Taken together, our results suggest that the elevated temperature (T3) leads to reduction in grain yield regulating number of grains/spike, whereas increasing the gluten content by regulating the expression of starch and gliadin-related genes or gluten metabolism process genes expression. Our results should be provide a useful physiological information for the heat stress response of wheat.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.251-254
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• 2001

In this paper, the effect of grain refinement on room temperature ductility of copper was addressed. Recent experimental results have shown that this material, as well as a number of other single-phase metals that are ductile when coarse-grained, loose their ductility with decreasing grain size in the sub micrometer range. A recently developed model in which such materials are considered as effectively two-phase ones (with the grain boundaries treated as a linearly viscous second phase) was applied to analyze stability of Cu against ductile necking. As a basis, Hart's stability analysis that accounts for strain rate sensitivity effects was used. The results confirm the observed trend for reduction of ductility with decreasing grain size. The model can be applied to predicting the grain size dependence of ductility of other metallic materials as well.

• 한국작물학회지
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• 제47권6호
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• pp.443-447
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• 2002

참깨 재배조건에 따른 생육과 수량 및 품질 차이를 구명하고자 수행한 연구결과는 다음과 같다. 1. 비닐하우스 재배가 노지 재배에 비해 개화기가 빠른 반면 성숙기가 늦어 생식생장기간이 길었다. 또한 경장과 착삭부위장이 매우 길었다 한편 주당삭수가 많고 천립중이 무거워 수량이 57%가량 많았다. 2. 비닐하우스 재배에서는 6월 8일 파종구가 5월 9일 파종 구에 비해 착삭부위장이 길었다. 그리고 주당삭수가 많고 천립중이 무거웠다. 또한 착삭 상단부위 등숙율이 높고 착삭 중, 하단부위 천립중이 무거우나 수량은 비슷하였다. 3. 노지 재배에서는 5월 9일 파종구가 6월 8일 파종구에 비해 유효분지수와 주당삭수가 많았다. 그러나 착삭 상, 중단부위의 등숙율이 낮고 천립중이 가벼워 수량은 비슷하였다. 4. 종실의 $L^*$값은 재배조건에 따라 차이가 없었고 $a^*$값은 비닐하우스 재배에서 높았으나 $b^*$값은 노지 재배에서 높게 나타났다 그리고 파종기간 색차($\Delta E^*{ab}$)는 노지 재배에서 가장 높게 나타났다. 5. 비닐하우스 재배에서는 수용성 성분인 세사미놀 배당체 함량이 높고, 노지 재배에서는 세사민과 세사몰린 함량이 높게 나타났다.