• 대한화학회지
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• 제27권1호
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• pp.46-52
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• 1983

한 분자내에 클로로, 니트로, 에스테르 및 니트릴기를 포함하는 할로겐 화합물에서 수소화붕소리튬을 이용한 할로겐의 선택환원이 논의되었다. 1-브로모-4-클로로부탄은 96%의 수득율로 1-클로로부탄으로, 브롬화 p-니트로벤질은 98%의 수득율로 p-니트로 톨루엔으로 환원되었으나 요오도프로피온산 에틸에스테르나 4-브로모부티로니트릴의 경우 선택환원의 수득율이 낮았다. 그러나 당량의 피리딘 존재하에서 이 반응을 시키면 프로피온산 에틸에스테르는 93%, 부티로니트릴은 88%로서 각각 선택환원의 수득율이 향상되었다.

• 한국연초학회지
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• 제7권1호
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• pp.7-13
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• 1985

Effect of the two PVY strains(PVY-VB and PVY-VN) on yield and chemical constituents of tobacco plants was determined in roar. NC2326 and Burley 21. The virus was inoculated 6 and 8 weeks after transplanting, respectively. The strains and time of inoculation were most critical factors for yield reduction. The greatest reduction was caused by the necrotic strain (PVY-VN) inoculated 6 weeks after transplanting, accounting for the loss of 40% in var. NC2326 and of 45% in var.. Burley21. When inoculated 8 weeks after transplanting with the necrotic strain, only 17% reduction was recorded in roar. Burley21, but no reduction occurred in roar. NC2326. Generally less reduction was caused by the PVY-VB strain, ranging 12-16% depending on the time of inoculation and/or variety. Compared to healthy tobacco, PVY infected tobacco contained higher concentrations of total nitrogen, protein nitrogen, nitrate nitrogen, and lower total sugar in cured leaf of roar. NC2326. Total alkaloid, P, Mg, Ca, and K levels were not altered. In var. Burley21, protein nitrogen and nitrate nitrogen increased, but other chemical components were not changed. Necrotic strain-infected tobacco with a severe symptom had higher nitrogen than did mild strain-infected tobacco.

• 한국재료학회지
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• 제11권12호
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• pp.1047-1051
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• 2001

Purity tantalum powder has been produced by sodium reduction of potassium tantalum fluoride($K_2TaF_7$)in a stainless steel bomb. The influence of experimental variable, such as excess of reductant and temperature of reduction on the yield and quality of the Ta powder has been studied. The excesses of reductant were varied from -20%, -10%, 0%, 5%, 10%, 20%. When -20% excess of sodium was used, the un-reacted sodium remained in the reacted product. The yield of 81% of Ta powder has been achieved by reducing 50g of$K_TaF_7$with 5% sodium in excess of stoichiometric amount in presence of 16.8g of sodium chloride in the charge at a reduction temperature of$905{\circ}C$. The proportion of fine fraction(~325mesh) decreased appreciably with the increase of sodium excess, and the yield of tantalum powder improved from 65% to 94%. The average particle size of Ta Powder is improved from 3 microns to 4 microns in the 5% excess sodium.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.236-243
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• 2000

A number of developments have occurred over recent years that are being used commercially or have the potential to increase the milk yield and consequently the efficiency of dairy cows. Bovine growth hormone is the most widely known of several attempts that have been made to alter the metabolic endocrinology of dairy cows to increase the rate of milk secretion. The factors affecting the milk yield response to growth hormone, growth hormone-releasing factor, thyroxine and placental lactogen as well as to the immuno-neutralization of somatostatin are briefly considered. Secondly, the recent greater understanding of the mechanism by which the milk yield is increased following more frequent milking, which has resulted from the identification and characterization of the feedback inhibitor of lactation (FIL) protein, is reviewed. The identification of this protein provides new avenues of research which may lead to a reduction in the rate of decline in milk yield with advancing lactation or to undiminished milk yields despite a reduction in frequency with which the animals are milked.

• 한국농공학회논문집
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• 제56권3호
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• pp.47-53
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• 2014

We investigated the effect of straw mat cover and soil amendments on the reduction of runoff, non-point source pollution load and yield of a Chinese cabbage from alpine fields. Two plots on sandy loam soil were prepared. Experimental treatments were control and rice straw mat cover (3,300 kg/ha)+Polyacrylamide (PAM) (5 kg/ha)+Gypsum (1 ton/ha) (SPG). A variety of Chinese cabbage was cultivated and runoff was monitored during a growing season in 2012. Monitoring was conducted to seven times. Runoff rate of SPG plot was lower than those of control plot. The reduction rate of runoff from SPG plot was 29.4 % compared to control plot. The reduction rate of suspended solids (SS), total nitrogen (TN) and total phosphorus (TP) load of SPG plot was 86.5 %, 34.7 % and 39.1 %, respectively. Yield of a Chinese cabbage from SPG plot (39,646 kg/ha) was greater than that of control plots (28,482 kg/ha). It was concluded that the use of SPG on soil surface could not only reduce the NPS pollution loads in receiving waters but also help increase the crop yield.

• 대한기계학회논문집B
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• 제31권6호
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• pp.522-530
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• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method and the composition analysis for data collection and data analysis were respectively used in the main board and the cellular phone module production lines. And these methods were evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. While in case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines.

• 한국작물학회지
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• 제44권4호
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• pp.321-329
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• 1999

The effect of water deficits on soybean [Glycine max (L.) Merr.] could appear on seed quality through changes of morphological plant characteristics. Two Korean genotypes, Hwangkeum (determinate growth habit) and Muhan (indeterminate growth habit), were used to examine the influences of treatment stage and method of water deficit during reproductive growth period on yield and seed quality of soybean. Water deficit at R5 or R6 stages was as damaging to seed quality as double water-deficit treatments at R2+R5 or R2+R6. However, seed from double water-deficit treatment tended to have lower oxidation-reduction potential compare to the corresponding single water-deficit treatment. In comparison with Muhan, Hwangkeum had significantly greater oxidation-reduction potential value. Seed yield per plant in both genotypes depended greatly on seed yield of branches. However, the proportion of number of branch seed to total seed umber in Hwangkeum was increased as the water deficit was applied during later reproductive stage, whereas, in Muhan the proportion was lower. Water-deficit treatments including the single and double water-deficit treatments and non-stressed treatment were able to be classified into five groups for Hwangkeum and four groups for Muhan based on the influences on yield components, number of pod, number of seed, and single seed weight, using principal component analysis. In both genotypes, R2+R5 water-deficit treatment decreased number of pod and seed, but increased single seed weight. On the contrary, R6 or R2+R6 stress increased the pod and seed number, but decreased single seed weight.

• 열처리공학회지
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• 제15권1호
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• pp.16-20
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• 2002

In conventional metallothermic reduction(MR) for obtaining tantalum powder in batch-type operation, it is difficult to control morphology and location of deposits because the reaction occurs by direct physical contact between reductants and feed materials. On the other hand, a electronically mediated reaction(EMR) is capable to overcome these difficulties through the reaction by electron transfer and have a merit of continuous process. In this study an MR and EMR method has been applied to the production of a tantalum powder by sodium reduction of $K_2TaF_7$. As the reduction temperature increases, the particle size and yield of tantalum powder obtained by MR and EMR method is increased.

• 한국경영과학회지
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• 제36권3호
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• pp.61-74
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• 2011

The objective of this study is to evaluate the effects of sharing uncertain yield information with a downstream supply chain player. We are interested in understanding how the amount of yield uncertainty affects the supply-side benefits and/or costs, which has not been considered in the literature, in addition to the customer-side benefits. With that purpose, this work evaluates a supplier who provides yield information in comparison with another supplier who shares no information. We simulate an order-up-to type heuristic policy that is adapted from the literature and reasonably modified to represent yield information sharing with error. From the simulation study, we argue that the customer would experience cost reduction, but the cost for supplier's inventory is increasing when sharing yield information. Furthermore, the amount of benefits and costs are situational and affected by level of yield uncertainty and demand variance. Based on the simulation study, we finally make several recommendations for the supply-side approaches to yield information sharing.

• Spatial Information Research
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• 제17권4호
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• pp.431-443
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• 2009

최근 탁수문제는 댐과 저수지관리 업무에서 중요한 이슈중의 하나가 되고 있으며, 고탁수를 유발하는 주요원인은 강우강도 에너지에 의한 유사량이다. 기존의 연구들은 다양한 작물형태를 고려하지 않아 정확한 토양 침식 및 유사량을 계산할 수 없었다. 본 연구에서는 IKONOS 위성영상으로부터 추출한 인삼밭 레이어를 이용하여 토양침식량과 유사량의 저감효과를 분석하였으며, 인삼밭의 면적과 점유비율은 각각 $0.290km^2$와 0.94%로 나타났다. GIS 기반 RUSLE 모델을 이용하여 인삼밭을 고려한 토양침식량의 저감효과를 분석한 결과는 0.9%로 낮게 나타났으며, 이는 인삼밭의 면적이 다른 농경지에 비해 상대적으로 작기 때문으로 해석된다. 미래의 토지이용변화를 반영하기 위해, 본 연구에서는 논, 밭, 과수원 그리고 기타 재배지들이 인삼밭 지역으로 전환된다는 시나리오를 고려하여 토양침식과 유사량의 저감효과를 평가하였다. 시나리오에 따른 인삼밭의 저감효과를 분석한 결과, 밭지역을 인삼밭으로 전환한 시나리오 (1)과 모든 농경지를 인삼밭으로 전환한 (4)가 인삼밭을 고려하지 않은 기존의 연구와 비교할 때 31.3% 및 34.8% 더 높은 저감효과를 나타내었다. 본 연구에서 제시한 방법론은 고탁수와 관련된 저수지관리를 지원하기 위한 매우 효과적인 도구가 될 수 있을 것이다.