We have seen the effects of buffer layer in organic light-emitting diodes using poly(N-vinylcarbazole)(PVK). Polymer PVK buffer layer was made using static spin-casting method. Two device structures were made; one is ITO/TPD/Alq3/Al as a reference and the other is ITO/PVK/TPD/Alq3/Al to see the effects of buffer layer in organic light-emitting diodes. Current-voltage characteristics, luminance-voltage characteristics and luminous efficiency were measured with a variation of spin-casting speeds. We have obtained an improvement of luminous efficiency by a factor of two and half when the PVK buffer layer is used.

다양한 리모델링 시공 중 추가적인 하중저항을 확보하기 위한 기초시공에서는 경제성, 시공성, 소음/진동 등의 이유로 헬리컬 파일을 사용하고 있으며, 좁은 공간에서 소규모 장비를 사용하여 회전관입하므로 파일의 길이가 3m로 제한되어 다수의 연결부가 소요된다. 이러한 연결을 위해 주로 가격이 낮은 pin 타입의 연결부가 사용되고 있으나 토크에 대한 저항력이 낮고 그라우팅이 어려운 단점을 가지고 있다. 이에 기존 대비 20% 이상 토크저항성을 가지며 동시에 경제성을 확보할 수 있는 새로운 헬리컬 파일 연결부를 고안하였고 유한요소해석을 통해 구조성능을 분석하였다.

This study was conducted to determine the optimum number of inter-rows according to distance of drainage furrow (DF) for running-off excessive-water stress (EWS) in paddy field. The most soil water potential was shown in high ridge (distance of DF by 70 cm) cultivation and the soil water potential showed increasing tendency in over four inter-rows cultivation by DF. The growth of soybean reduced by extended inter-row and its reducing level was high, especially, over four inter-rows (DF distance by 2.8 m) because of EWS. The photosynthetic rate decreased in the more extensive field by distance of DF at V5 and R2 stages, especially, in over four interrows cultivation. Also, root activity decreased at wider DF. The yield was reduced with wider distance of DF more extensively, the highest yield of 270 g per m2 at the every row, but yield showed decreasing tendency at over the 4th row (2.8 m) cultivation. Soybean cultivation in paddy field could be founded with DF of every other or 4th row.

This study was carried out to determine adequate planting date, to compare the growth characteristics between early and late maturing cultivars, and to provide the data for the cultivation techniques of soybean [Glycine max (L.) Merr.] in double cropping system with winter crops on paddy field in Korea. Cultivars were planted on 26 May, 16 June, and 7 July with a planting density of 70cm(row~;widtb)~;~times~;10cm (planting spacing). Seed yield of soybean planted on June 16 and July 7 was approximately 37~%~;and~;53~% , respectively, less than that of conventional planting date of May 26 in Pungsan-namulkong, and planted on June 16 and July 7 was about 30~%~;and~;37~% , respectively, less then that of conventional planting date of May 26 in Hanamkong. The number of pods and seeds per plant decreased as planting date delayed. Seed weight increased in Pungsan-namulkong but decreased in Hannamkong as planting date delayed. The flowering date was late in delayed planting plots, but it was shorted for days from emergence to flowering and from emergence to maturity. The plant height of Hannamkong was greater than Pungsan-namulkong from the emergence to flowering stages, but in contrast, it was greater in Pungsan-namulkong than Hannamkong after flowering stage (50d after emergence) when it planted on May 26. There were no significant differences between two soybean cultivars at planting dates of June 16 and July 7. Leaf number, leaf area, and dry matter were also reduced by late planting, and Both of them were shown in high reduction at the later planting. There was a high significant difference at the flowering (r~;=~;0.87**) and pod formation (r~;=~;0.91**) stages between leaf dry matter and seed yield. Crop growth rate (CGR) was greater at R2~~R3 growth stages compared to R3~~R4~;or~;R4~~R5 growth stages in two soybean cultivars and the greatest CGR was obtained at planting date of May 26 in two soybean cultivars except for R4-R5 growth stage in Pungsan-namulkong. There was a highly significant positive difference between the seed yield and the leaf area index (LAI) across R3 to R4 and R2 to R3 stages. The photosynthetic rate (PN) of the uppermost leaf position had no significant difference among planting dates and between two soybean cultivars. However, PN of the 7th leaf position increased as the planting date delayed.

This experiment was carried out at paddy field (commercial silty loam soil) in the southwestern Korea. Pungsannamulkong, a determinate growth habit, was a relatively high yielding and late maturing cultivar, and Han­namkong, a semi determinate growth habit, was a relatively low yielding and early maturing cultivar. Seeds were sowed at two plants and with a planting density of 70~times10cm on May 26, 2003. Fertilizer was applied prior to planting at a rate of 3.0-3.0-3.4g (N-P2O5-K2O)~;per~;m2 by all basal fertilizations. Experimental design was a randomized complete block with three replications. Seed yield was higher in Pungsannamulkong by 362g per m2 than in Hannamkong of 260g per m2 Also, the number of pod, number of seed, and number of seed per pod were greater in Pungsannamulkong than in Hannamkong. The number of leaves per m2 showed similar with two soybean cultivars up to August 24 but thereafter it decreased in Hannamkong. The leaf area up to August 4 increased in Hannamkong higher than in Pungsannamulkong, but after that time, Pungsannamulkong had greater leaf area than Hannamkong. The shoot and leaf dry matter of two soybean cultivars from June 23 to August 4 were similar but thereafter, Pungsannamulkong had a significantly greater than Hannamkong. Crop growth rate (CGR), relative growth rate (RGR) and net assimilate rate (NAR) for Punsannamulkong were relatively higher than Hannamkong but leaf area ratio (LAR) and specific leaf weight (SLW) showed higher in Hannamkong. Most of leaves distributed in the ranges of 80-90cm and 60-70cm from the soil surface in Punsannamulkong and Hannamkong, respectively. Pods of Punsannamulkong ranged 10-80cm from the soil surface and most of pods were distributed at 40-50cm. Photosynthetic rate at the flowering stage showed a significant difference between cultivars in the upper most leaf position. There was no significant difference of the photosynthetic rate at 7tn leaf at the flowering stage, and the uppermost and 7th leaf position at the seed development stage between two soybean cultivars.

This study was conducted to investigate the effect of the salinity on growth, inorganic ion content, and photosynthetic rate (~textrmPN ) in Korean ginseng (Panax ginseng C.A. Meyer) with complex fertilizer (CF) and NaCl concentrations. The salinity was applied to plant using NaCl and CF, and controlled an EC as 0.0, 1.0, 2.0 and 3.0 dS ~textrmm-1 . The salinity treated three times at 35, 42 and 49 d after transplanting. The leaf area in different electrical conductivity (EC) decreased only the higher NaCl 1.0 dS ~textrmm-1 . The root growth increased with CF and especially, it was two times higher at 3.0 dS ~textrmm-1 than that of control. But the root growth sharply decreased with NaCl compared to CF. The light saturation point of Korean ginseng was around 100 ~mu~textrmmol~;~textrmm-2~textrms-1 photosynthetically active radiation (PAR), and ~textrmPN increased as CF increased but decreased with NaCl especially at the late growth stage. The ~textrmNa+ content in Korean ginseng increased sharply with NaCl.

This study was conducted to determine the effect of salinity on the growth and development of Korean ginseng (Panax ginseng C.A.Meyer) and to evaluate the inorganic ion content in Korean ginseng with different general complete fertilizer (GCF) and NaCI concentrations at two growth stages. The stem height of Korean ginseng treated with different GCF and NaCI concentrations decreased at the higher EC (2.0 dS m-1 ), but there were no significant difference in the stem diameter, the leaf length, and the leaf width among different treatments. The root growth increased with the supply of GCF. Especially, the root growth was facilitated two times at 3.0 dS ~textrmm-1 as compared to control. But the root growth more sharply decreased with NaCI treatment than GCF. The ~textrmK+ and ~textrmMg2+ content in leaves and roots increased with GCF at the early growth stage. At the late growth stage, the ~textrmK+ content in leaves decreased but the ~textrmCa2+ and ~textrmMg2+ content increased. The ~textrmCa2+ and ~textrmMg2+ content in roots increased but the ~textrmK+ content decreased. The ~textrmNa+ content in Korean ginseng increased sharply with NaCl treatment. The ~textrmNO3- content in leaves and ~textrmNH4+ content in leaves and roots increased as GCF concentration increased. The ~textrmNO3- content in leaves, stems, and roots at the late growth stage decreased as NaCl concentration increased. The ~textrmNH4+ content in leaves and roots decreased significantly at the early growth stage, but it decreased significantly in leaves and stems at the late growth stage. The root activity of Korean ginseng increased with GCF, but decreased as the EC increased with NaCl. The water potential of leaves with GCF showed no significant difference compare to control, but the water potential of leaves treated with NaCl decreased as EC increased.

This study was conducted to elucidate the changes of photosynthetic ability and cation content in barley cultivar seedlings cultured for 10 and 30 days with different NaCl concentrations containing 1/4 Hoagland solutions. At the highest NaCl concentration, the weight of dry matter and the shoot/root ratio (S/R ratio) were decreased. Thus, shoots were affected more than roots by NaCl treatment. The S/R ratio decreased more in 'Neulssalbori' than in 'Bunong' by the NaCl treatment. The. internal Na+ concentration increased greatly with the highest NaCl concentration, but K+ concentration in plants decreased with the highest NaCl treatment. The Ca2+ concentration had a small change with NaCl concentrations. Thus Na+ /K+ and Na+ /Ca2+ ratios increased with the highest concentration. The chlorophyll content (%/dry weight) of seedlings decreased at higher NaCl levels except for Bunong in 30 day old seedlings. The photosynthetic ability decreased only for Neulssalbori in the 10 days NaCl treatment. The stomatal conductance, and transpiration had decreased in the 10 day old seedlings, but not with 30 day old seedlings.