• Progress in Superconductivity
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• 제4권2호
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• pp.162-167
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• 2003

The critical current value of Bi-2223/Ag tape can be influenced by various factors. In particular, it was known that properties of precursor powders could affect the formation of Bi -2223 and grain growth rate of the same. Since, moistures and organic matters can easily contaminate the precursor powders of Bi-2223 tapes and degrade properties of superconductors, the precursor powders should be kept in optimal conditions to minimize contamination. In this study, the effect of moisture and organic matters has been investigated. A Bi-2223/Ag tape contaminated with a large amount of moisture and organic matter has been characterized by low critical current values and bubbling. It has been found that as the quantity of moisture increases, the Bi-2223 phases are formed at lower temperature and the amount of non-superconducting phase increases.

• 한국작물학회지
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• 제58권3호
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• pp.239-252
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• 2013

국산밀을 재배하는 전국 175농가를 대상으로 2년 동안 농업형질과 원맥 특성을 조사 한 결과, 간장, 수장, 경수와 이형주율은 년차간 차이를 나타내었다. 시비량이 많았던 남부지역에서 재배된 밀의 간장이 중북부 지역 보다 길었으며, 추비시기는 간장에 영향이 없었지만, 3월 중순 이후에 늦게 추비를 준 농가의 수장은 다른 농가에 비하여 길었으나 경수는 감소하였다. 추비 횟수는 농업형질에 영향을 미치지 않는 것으로 나타났다. 농업형질과 마찬가지로 원맥 특성도 연차간 변이가 있었으며, 남부지역에서 재배된 밀은 중북부지역에서 재배된 밀에 비하여 천립중이 높았으며, 리터중은 낮았으며, 전라북도는 다른 지역에 비하여 낮은 회분 함량과 높은 단백질 함량을 나타냈으며, 전라남도는 다른 지역에 비하여 높은 회분 함량을 나타내었다. 추비시기가 리터중에는 영향을 주었지만 천립중과 회분 및 단백질 함량에는 영향을 주지 않았으며, 추비 횟수도 원맥 특성에 영향이 없는 것으로 나타났다. 시비량에 따라 간장이 증가하고, 천립중과 단백질 함량이 증가하였으며, 수장과 회분함량은 시비량과 부의 상관을 나타내었다. 단백질 함량은 천립중과 정의 상관을 나타내었지만 회분 함량은 천립중 및 리터중과 부의 상관을 나타내었다. 간장이 증가할수록 천립중은 증가하고 리터중은 감소하였으며, 수장은 천립중과 부의 상관을 나타내었다. 시비량이 간장 및 원맥 특성에 영향을 미치기 때문에 품종별 용도에 맞는 밀 품종을 재배하기 위해서는 적정 시비기술에 대한 농가 지도가 필요하다. 또한, 국산 밀의 생산성 증진과 품질 향상 및 균일성 확보를 위해서는 용도별 가공적성에 적합한 품종에 대한 집단 재배단지를 조성하고 철저한 생산 관리와 체계적인 수확 후 관리 구축에 대한 종합적인 고려가 있어야 할 것이다.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.60-71
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• 1996

The purposes of this study were to develop a simulation model and to determine minimum specific airflow rate requirements for natural air drying of rough rice in Korea. A simulation model was developed considering energy and mass balances within grain bed, drying and rewetting rates, and hysterisis effect between sorption and desorption isotherms. As the results of validation test, the moisture contents predicted by the model agreed very well with the actual data. The criteria for determining minimum specific airflow rate requirements was that the top loom layer in the bin be dried to a moisture content below 16 percent wet basis with less than 0.5% drymatter decomposition. The minimum specific airflow rate requirements in 13 locations of Korea were presented based on the worst one among the past 7 to 13-year weather data. These requirements were also presented for all the combinations of three harvest dates and four harvest moisture contents. Specific airflow rate requirements seemed to be half by each 2 percent reduction in moisture content from 24 percent. As harvest date was delayed by 10 days from October 1, these requirements were reduced by about 20 to 40 percent.

• 한국환경과학회지
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• 제4권5호
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• pp.427-435
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• 1995

In order to discuss the differences among the SMP(Surface Moisture Availability Parameter), by previous researchers on the basis of their own theoretical and empirical background, we assessed the SMP according to the soil types and volumetric soil water contents. The results are as follows. There are differences among all the five SMAPs. There's a tendency that the larger grain size, the higher value of parameters. And they divided into two groups for their value: one group has parameters with exponential function and the other with cosine and linear function. The maximum difference between the two groups appears when the volumetric soil water contents are 0.07m3m-3 for sand, 0.l1m3m-3 for loam, 0.12 for clay, and 0.13m3m-3 for silt loam. So, these differences must be considered when we estimate the surface evaporation rate. From field data, the paddy field soil around Junam reservoir is classified as a silt has high wetness, 0.56. So, the parameter obtained from the field measurement is much higher than that of Clapp and Hornberger(1978)'s Table. This study treated the SMP for a certain point of time in winter season. But if we measured the soil water contents continuously, we could obtain better time-dependent parameter. Key words : SMAP(Surface Moisture Availability Parameter), Paddy field, Volumetric soil water content, Evaporation, Capillary potential.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.354-360
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• 2020

본 연구는 잡곡(조, 기장, 수수)의 물리적 특징 중 기하학적 특성, 산물밀도 및 종말속도를 함수율별로 분석하여 미곡가공시설의 선별 장치를 이용하여 잡곡의 선별의 가능성을 위한 기초자료로 활용하기 위하여 연구를 수행하였다. 조, 기장 및 수수의 초기함수율은 16.3, 19.8, 16.5 %(w.b.)로 나타났다. 잡곡은 5수준으로 건조하여 실험에 사용하였다. 잡곡의 기하학적 특성 중 원형율을 제외하고 단축, 장축 및 면적은 함수율이 높을수록 증가하는 것으로 나타났으며, 1차식 실험모델로 모두 표현이 가능하였다. 산물밀도는 조 및 기장은 함수율이 높을수록 증가하는 것으로 나타났으나 수수의 경우는 함수율과 무관하였다. 종말속도는 함수율이 높을수록 종말속도가 증가하는 것으로 나타났으며, 1차식 실험모델로 표현이 가능하였다. 잡곡별 측정한 물리적 특성은 함수율의 변화에 따른 1차식 실험모델로 표현이 가능하였으며, 기존 미곡선별장치를 이용할 경우 종말속도를 이용하는 장치는 사용이 가능하지만 기하하적 특성 및 산물밀도를 이용하는 공정은 잡곡에 따라 전용 공정의 설계가 별도로 필요하였다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.922-931
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• 1993

Boundary element method was used to solve heat conduction problem for predicting temperature distribution in grain storage bin. Temperature of grain in storage is one of the three main abiotic factors, besides the intergranular gas composition and the grain moisture content, that determine the keeping quality and control measures used to protect grain from insects and damaging microflora. Collecting the temperature data at various points in the storage bins at different time of the day over a period of time is one way of finding the temperature distribution, this method requires a lot of time, cost and labour and less efficient. However data so collected serve useful purpose of being used to validate predicted temperature distribution using mathematical models. Mathematical models based on physical principles can potentially predict with accuracy the temperature distribution in a grain storage bin. Using the boundary element model the effect of bin wall material, ambient emperature, bin size etc. on temperature distribution can be studied. A knowledge of temperature distribution in stored grain not only helps in identifying active deterioration , but also gives an indication of potential for detection.

• 한국식품조리과학회지
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• 제18권6호
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• pp.593-602
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• 2002

The objective of this study was to investigate the sensory and quality characteristics of Gamjeobyung containing different ratios of ingredients such as heated potato flour(30%, 40%, 50%), potato starch(30%, 40%), sugar, honey, and water by sensory evaluation and mechanical examination. The results of sensory evaluation showed that Gamjeobyung containing 30% heated potato flour, and potato starch had higher scores in overall acceptability, color, flavor, grain, moistness, chewiness and sweetness preferance. In the textural analysis of Gamjeobyung, the cohesivenss, springiness, adhesiveness were the highest in the samples with 30% potato starch, and the chewiness, gumminess, and hardness were the highest in the 40% added samples. The hunter's color L value and b-value of Gamjeobyung was decreased and a-value was increased of potato starch. The moisture content of Gamjeobyung was higher in the samples with heated potato flour than the samples with potato starch.

• 한국식품조리과학회지
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• 제19권4호
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• pp.493-503
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• 2003

The purpose of this study was to investigate the sensory and mechanical characteristics of Mohaebyung by the addition of chestnut, jujube, dried persimmon, pine nut, and codonopsis lanceolata flours. In the sensory evaluation of Mohaebyung, the acceptance for the color, moistness and sweetness was best with the addition of 25% mixed flour. The flavor, grain, chewiness and overall quality were best with the addition of 20% mixed flour. As a result of a textural analysis, the hardness and springiness of Mohaebyung decreased with increases in the addition of mixed flour. The redness, yellowness and lightness of Mohaebyung were increased with increases in the addition of mixed flour. A moisture content of 15% in the mixed flour added to the Mohaebyung was higher with 25% mixed flour.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.183-192
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• 2004

The effect of eight varieties of grain and forage type whole crop rice (Oryza sativa L Japonica) each harvested at four stages of maturity were investigated for morphology and yield, proportion of botanical fractions, fermentatability and chemical composition in an $8{\times}4$ factorial experiment. All crops were sown in 1997 at Saitama Prefecture, Japan under identical condition and harvested on 10, 22, 34 and 45 days after flowering in 1998. Total DM yield of forage type varieties was similar to that of the highest yield of grain type varieties. However, while yield of forage type varieties was attributed to higher proportion of straw than head, the reverse was in the case of grain type varieties. Yield in line with the proportion of head increased (p<0.001), but in contrast proportion of straw decreased (p<0.001) with the increase in maturity. Silage fermentability of grain type varieties was better than forage type varieties. Fermentability improved with the increase (p<0.001) in maturity suggesting that the moisture content should be reduced to improve fermentation quality. Forage type varieties contained higher (p<0.001) ash, crude fat (EE), organic cell wall (OCW) and acid detergent fiber (ADF), but contained lower crude protein (CP), organic cell content (OCC), CP in OCC and nitrogen-free cell wall extract (NCWFE) than the grain type varieties. The ash, CP, EE, Oa (60% digestible OCW), Ob (40% digestible OCW), OCW, ADF and acid detergent lignin (ADL) decreased (p<0.001), but OCC and NCWFE increased (p<0.001) with the increase in maturity. It is concluded that stage of maturity not only increases yield and proportion of head, but also improved the fermentation quality and increases quality chemical composition (except CP) of whole crop rice. Forage type varieties may be as good as grain type varieties in terms of yield, but fermentation quality and chemical composition may not be as good as that of grain type varieties.

• Journal of Biosystems Engineering
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• 제5권1호
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.