• 한국해양공학회지
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• 제5권1호
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• pp.64-70
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• 1991

The design theory of roller gate has been systematized laying more emphasis on practical formulas than theoretical ones and the design procedure of the existing gate facilites is reviewed and analyaed on economical viewpoint and safety factor. The design theory of timoshenko, the thechnical standards for hydraulic gate and penstock of Japan, and the design standards for waterworks structures of Germany are applied to the study of optimal design of a gate leaf. In this study, gate leaf which is now being operated for water control at the seadike, estuary dam and reservoir dam are adopted as a mode, and a new design method by the computer is proposed through the variation of design elements within practical ranges. As a result, safety factor and economical design can be made by using T-beams to the horizontal and vertical beam of the gate leaf instead of H-beams used in the existing seadike roller gate at Asan, and total weight of gate leaf is reduced by the present optimization.

• 생명과학회지
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• 제10권1호
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• pp.52-60
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• 2000

Up to now, there have been done much efforts in regard to nitrate reductase activity (NRA) of dicotyledonous herbs and important crop monocotyledons, but few to wild plants having canopy structure such as Carex. The objective of the present study are to determine: a) the optimum in vivo NR assay conditions for leaf samples of Carex species, b) changes of NRA according to section within leaf and leaf ages, c) diurnal variations. Optimized assay media of each Carex species were determined. NRA of C. rostrata adapted to oligotrophic habitats is readily saturated at lower substrate concentration than those of C. distans and C. gracilis, adapted to meso- and eutrophic habitats, respectively. All Carex species investigated have higher NRA in leaves than in roots. NRA of all species showed maximal values at the middle section of each leaf and in the youngest fully expanded leaves. Compared to C. gracilis, NR in leaves of C. distans was adapted readily to the light period. On the whole, Carex showed rather delayed diurnal variation. Even if the in vivo nitrate reductase assay based on nitrite estimation does not give an accurate estimation of total nitrate reduced, it still serves as a useful tool to find out relative differences in varying environmental conditions. Additionally, in vivo RNA measurements are helpful to understand nitrate reduction and basic nitrogen metabolism of Carex species having different canopy structure.

• 한국작물학회지
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• 제44권1호
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• pp.11-19
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• 1999

This experiment was conducted with nine wheat geno-types to choose the wheat which has excellent early vigour. 'Vigour 18' and 'ZL 59A' are excellent in the long coleoptile genotype, while 'Amery' and 'Janz' are excellent in the short coleoptile genotype. Responding to the growth stage and nitrogen level, Vigour 18 is predominant in the long coleoptile genogype, while Janz in the short coleoptile genotype. Responding to sowing density and nitrogen level, the higher the sowing density was, the shorter the leaf area of Vigour 18 and Janz. Also the leaf area turned out to larger in the plot fertilized with high nitrogen than in the plot fertilized with low nitrogen. This is true of leaf weight and root weight. Concerning specific leaf area (SLA) and leaf area ratio (LAR), the higher the sowing density was, the SLA tended to grow larger, while the SLA grew larger in the plot fertilized with low nitrogen, as were found in Vigour 18 and Janz. The roots of long coleoptile genotype, Vigour 18, turned out to grow longest on the plot sown with 3 seeds. While the roots of short coleoptile genotype, Janz, grew longest on the plot sown with 2 seeds. The relative growth rate (RGR) was the same at low N rates and high N rates. The RGR was 0.071 and 0.072 g $g^{-1}d^{-1}$ at low N rates and high N rates. The partitioning of RGR into net assimilation rate (NAR) and LAR showed that the average LAR at low N rates was similar to the LAR at high N rates. Variation within each cultivar in the LAR and NAR was small relative to the difference between them at low N rates and high N rates. Above ground mass was 8.2 mg greater at high N rates than low N rates, whereas leaf area was 0.05 $\textrm{m}^2$$kg^{-l}$ greater at high N rates than low N rates. The NAR was similar at low N rates and high N rates, whereas LAR was greater at high N rates (0.05 $\textrm{m}^2$$kg^{-l}$); variation in SLA was responsible for the variation in NAR and LAR both at low N rates and high N rates. NAR was more closely associated with the reciprocal of SLA.

• 한국작물학회지
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• 제49권3호
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• pp.199-206
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• 2004

Typhoon "MAEMI", happened in September 2003, hit the great damage to Gyeongnam province area. Especially, rice plant was lodged or severe leaf damage was caused. This study was conducted to find out the extents of leaf damage among different rice cultivars, and to evaluate rice yield and eating quality due to leaf damage after typhoon. Rice cultivars torn off over half of the flag leaf length (FLL) were one medium-late maturing cultivar (Donginl), medium maturing cultivar (Yeonganbyeo), eight early maturing cultivars (Samcheonbyeo, Jounghwnbyeo, Munjangbyeo, Taebongbyeo, Odaebyeo, Samhaegbyeo, Sobaegbyeo, Sinunbongbyeo), two long-il type cultivars (Samgangbyeo, Namcheonbyeo), and three special use cultivars (Heukseonchalbyeo, Jinbuchalbyeo, Yangjobyeo). Cultivars torn off below 1/10 FLL were eight medium-late maturing cultivars (Chucheongbyeo, Daecheongbyeo, Saechu cheongbyeo, Donganbyeo, Daeyabyeo, Hwamyeongbyeo, 방eongsanbyeo, Dongjinbyeo) and two medium maturing cultivays (Donghaebyeo, Gumobyeo2). The rest cultivars were tore off by 1/10∼1/2 ELL. In yield components, the longer was flag leaf damage, the lower was ripened grain ratio, grain weight and brown/rough rice ratio, which was severly impacted to late than to ordinary season cultivation. However, rice yield did not decrease up to tearing by 1/10 ELL. Head rice ratio decreased from flag leaf tearing over 1/10 ELL in late season cultivation. The longer was flag leaf damage, the lower was eating quality, which could not show significantly different.

• 한국작물학회지
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• 제52권4호
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• pp.429-438
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• 2007

유묘활력(early growth vigor, EGV)은 초기 생장의 빠르고 늦음을 나타내는 특성이다. 유묘활력의 품종간 변이 및 관련형질간의 상호관계를 검토하여 유묘활력 간접선발지표를 찾고자 2003년 한국품종, 중국품종, IRRI품종 등 총 140개 품종을 대상으로 플라스틱하우스에서 시기를 달리하여 저온기와 고온기 2회, 봄철 보온절충 못자리에서 1회 등 총 3회에 걸쳐서 EGV 및 그 관련 형질 들을 조사하였다. EGV는 파종 후 일정시기가 지난 후에 측정한 생장량(건물중 또는 엽면적)으로 평가할 수 있다. 생육초기 엽폭과 엽장으로 정의되는 EGV 관련형질은 배와 종자의 무게와 고도로 유의한 정의 상관관계가 있었다. 특히 3엽장의 유전변이는 종자무게의 유전변이에 의해 90%이상 설명할 수 있었다. 이와 같이 종자무게는 초기활력이나 그 관련형질에 크게 영향하기 때문에 유묘활력에 미치는 종자 무게의 영향을 제거하고자 종자무게와 유묘활력 및 관련요소들의 직선적 또는 지수적 관계(식)로부터 종자무게의 영향을 배제한 유묘활력 및 관련 형질의 값을 계산하였다 종자 무게의 영향을 제거한 보정 유묘활력(EGVA)과 그 관련형질들도 품종간 큰 변이를 나타내었다. 생육초기 잎들의 엽폭 및 엽장은 EGVA와 높은 유전상관을 보일 뿐만 아니라 높은 광의의 유전력을 보였다. 생육초기잎들의 엽폭(2엽의 90%, 3엽의 93%)이나 엽장(2엽의 87%, 3엽의 89%)의 광의의 유전력은 EGVA의 광의의 유전력 81%보다도 높았다. 따라서 생육초기 잎인 제2엽과 3엽의 엽장 및 엽폭은 EGV를 간접적으로 선발할 수 있는 지표로 이용할 수 있을 것으로 판단되었다.

• 한국작물학회지
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• 제44권1호
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• pp.55-58
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• 1999

Plant water status during growth is directly and indirectly associated with seed yield. The objective of the present study was to determine the genotypic differences in leaf water characteristics at an early growth stage of soybean [Glycine max (L.) Merrill] plants through the pressure-bomb technique. Measurements of water potential as well as relative water content (RWC) were made at the third leaf from the fully-expanded top leaf of eight different soybean genotypes grown for 31 to 35 days after field emergence. On the basis of the modified exponential model, pressure-volume (PV) curves were fitted well ($R^2$=0.92＊＊ to 0.99＊＊ for the curvi-linear region and R=0.67＊＊ to 0.96＊＊ for the linear region), indicating that a segmented model using PROC NLIN of SAS could be used effectively to estimate the leaf water characteristics. The regression analysis for the pressure-volume (PV) curve revealed genotypic variation in the solute potential at saturation (Ψ$_{s,sat}$ :-10.7 to -14.8 bar), solute potential at incipient plasmolysis (Ψ$_{s,ip}$ : -14.3 to -18.3 bar), RWC at incipient plasmolysis (RW $C_{ip}$ : 83.3 to 91.7%), high integrated turgor pressure from saturation to plasmolysis ( $_1$$^{b}$ : 0.39 to 0.81), and maximum volumetric modulus of elasticity ($\varepsilon$$_{max}$ : 150 to 445 bar).).

• 한국작물학회지
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• 제40권3호
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• pp.371-381
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• 1995

콩에 있어서 특정부위의 source제거가 어느 부위의 sink에 영향을 주는가와 주요 sink인 협을 특정 부위에서 제거할 때 다른 부위의 sink에 어떠한 영향을 주는가 등을 절위별 협 및 종실의 변화를 중심으로 연구한 결과를 요약하면 다음과 같다. 1. 엽제거 부위별 절위당 협수변화는 엽제거 부위에서 감소를 가져왔으며 그 영향은 상부엽 > 분기엽 > 하부위 제거구 순으로 적었다. 2. 협제거 부위별 타부위의 절위당 협수 변화는 상부협 제거부가 주경의 중위절과 상위분기에서 협구가 약간 증가되는 경향이었고, 분기협 제거구는 주경의 모든 절위에서 약간 증가시키는 경향이었으나 하부협 제거구는 상위분기에서만 약간 증가시키는 경향이었다. 3. 엽제거 부위별 절위당 협당입수 변화는 엽이 제거되지 않는 부위에서만 약간 증가하는 경향이었고 협제거 부위별 절위당 협당입수도 협을 제거하지 않는 부위에서 약간 증가하는 경향이었다. 4. 엽제거 부위별 입당 입중변화는 엽제거 및 비제거 부위 모두 감소하였으나 협제거 부위별은 비제거부위에서 약간 증가하는 경향이었다. 5. 절위별 종실중은 엽제거부위에서 모두 감소하였고 동일부위에서는 상부가 하부보다 감소폭과 부위별 협제거에서는 상부협과 분지협 제거구가 지부위의 종실을 증가시켰으나 하부협 제거구는 오히려 종실중이 감소하였다. 6. 종피 구렬입율은 엽제거처리는 모두 낮았으며, 그정도가 엽이 제거된 부위에서 컸었고, 협제거 처리는 다른 부위의 종피 구렬입의 증가를 가져 왔으며 상부협 제거구가 그 경향이컸다.

• 약학회지
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• 제35권4호
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• pp.271-276
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• 1991

The extractability and stability of ginkgoflavonolglycosides under presence of several cellulose preparations were investigated. The enzymes used were macerosin, cellulose C and cellulase NC. The content variation of the glycosides was measured with HPLC method, using caffeic acid as an internal standard. The methanol extract of ginkgo leaf, containing the total flavonolglycosides of 4.46%, was used for the content comparison. By extraction with the enzymes, each or mixed, the peak levels of all the glycosides began to decrease after 1 or 2 hours. After 24 hour extraction, most of the glycosides were degraded to minor components. The flavonolglycosides in ginkgo leaf were also hydrolysed simply by the water extraction. After 24 hour extraction with water at $40^{\circ}C$, the peak levels of major glycosides were distinctly decreased. Rutin was hydrolysed by enzyme treatment or by ginkgo leaf itself. As a result, it was concluded that the commercially available cellulases and the ginkgo leaf itself contain the activities of $\beta$-glycosidase and $\alpha$-rhamnosidase. Kaempferol-3-O-(6'"-O-p-coumaroylglucosyl)-rhamnoside and four other ginkgo flavonolglycosides were not hydrolysed under the same condition.tion.

• 식물병과 농업
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• 제1권2호
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• pp.18-21
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• 1995

Mycosphaerella nawae, the causal organism, of spotted leaf casing disease of persimmon, was isolated from infected leaves showing typical symptom. The cultural characteristics of the fungus were compared on artificial media. Among 24 different combinations of culture media and supplements, oatmeal agar+persimmon leaf extract (PLE) and PAD+ PLE+streptomycin showed the highest rate of isolating as 57.1%. The best medium for mycelial growth of the fungus was PDA+persimmon leaf powder (PLP). The colony diameter was reached 47mm for 30 days at 2$0^{\circ}C$. PDA+PLE also supported good mcyelial growth showing 46mm of diameter in same condition. The optimum growth temperature of this fungus in PDA was recognized fairly low. The mycelial growth was higher at 2$0^{\circ}C$ than 15$^{\circ}C$. The variation of pH between pH 4 to pH 8 did not affect to the mycelial growth of the pathogen.

• 한국연초학회지
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• 제14권1호
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.