• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.292-298
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• 1997

These studies were conducted to verify the effect of the supplementary lighting by reflective film mulching and its establishment in the north side of greenhouse on the utility of light at tomato by means of investigating changes of leaf temperatures, stomatal features, transpiration rates and photosynthetic rates. Stomatal density of leaves were high in the reflective film mulching but sizes of stomata were not different. As the osmotic potential in rooting zone was low, the stomatal resistance was high, transpiration rate was low, and leaf temperature was increased by 40.62$^{\circ}C$. And also in the block of reflective film mulching photosynthetic rates were decreased hut chlorophyll contents were not different. Especially, there is an effect of controlling greenhouse whiteflies by treatment of reflective film mulching. It is thought that the reason of high quality or increasing yield at several crops by supplementary lighting, such as reflective film mulching, would be caused by influences of absorption and distribution of nutrients through high transpiration rate and photosynthesis which resulted from increase of stomata.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.53-59
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• 1986

The effects of soil moisture on seasonal changes of photosynthesis, transpiration and stomatal resistance were studied in sorghum (Pioneer 931) and sorghum - sudangrass hybird (Pioneer 988) at Suweon in 1985. Soil moisture was maintained with approximately 100, 80, 60 and 40% of field moisture capacity in large concrete pot (12m length $\times$ 1m width $\times$ 1m depth). 1. Photosynthesis and transpiration showed a sharp seasonal changes and reacted similarly to water stress and environmental factors, and were the highest in the middle of August, and were the lowest in the beginning of October. Sorghum - sudan hybird had better photosynthesis, transpiration and stomatal control than those of sorghum in hot summer season. 2. The rate of photosynthesis of 60 and 80% field moisture capacity was higher than that of 100 and 40% throughout growing season, but the effect of soil moisture on photosynthesis varied seasonally by climate factors. Optimum soil moisture was 60% in early summer and fall, and was 60 - 80% in hot summer season. 3. Drought and over-moisture affected physiological metabolism of plant, and so the dry matter yield of 40 and 100% field moisture capacity decreased by 70% compared with that of 60% field moisture capacity.

• Research in Plant Disease
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• v.12 no.1
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• pp.15-19
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• 2006

This study was carried out to know pathogenicity of the pathogen isolated in several location of Korea and penetration mechanism of the Pseudocercospora vitis ($(L\acute{e}v)$.) Speg. Inoculation tests at room temperature were performed on both sides of leaves with different isolates of the fungus. The typical symptoms appeared on the abaxial leaf surface, but no symptom was observed on the adaxial leaf surface with all isolates. The average incubation period was nine days, since all symptoms appeared from 8 to 10 days after inoculation. In order to know the mechanism of invasion of P. vitis to grapevine, the behavior of penetration hyphae through stomata were compared in two cultivars having different level of resistance. In order to know the mechanism of resistance of grape vine to P.vitis, two cultivars having different level of resistance were compared by counting the numbers and measuring size of the stomata per leaf. In a susceptible cultivar Campbell Early, the number of stomata was more than that of a resistance cultivar 'Kyoho'. In a susceptible cultivar 'Campbell Early', the fungus entered readily into stomata after inoculation. However, in a resistant cultivar 'Kyoho', the fungus seemed to pass over or surrounded only the guard cells. In comparison of height of guard cells of stomata between the two cultivars, significant differences were observed by scanning electron microscopy and light microscopy. The height of guard cells of 'Campbell Early' showed a little higher than those of 'Kyoho' known to be resistant to the fungus.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.50-56
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• 1998

Thirty-six $F_3$ hybrid poplar (Populus trichocarpa${\times}$P. deltoides) clones were fumigated with ozone to select for ozone sensitive and resistant clones. Fumigation was applied for 6 to 8 hours each day for approximately 3 months at ozone concentrations of 90 to 115 ppb using by open-top chambers. Height, diameter, number of leaves, total biomass, biomass components, root/shoot ratios, leaf drop and stomatal response were investigated. In summary, ozone generally reduced height, diameter, number of leaves, total biomass, and root/shoot ratios. Ozone stress induced leaf drop and foliar senescence in trees. This study showed very low relationship between total biomass and stomatal conductance. Increased plant resistant to ozone is not always correlated with stomatal behaviour. Probably, characterization of biochemical and other physiological responses to ozone exposure can provide a better understanding of tree response to ozone environment.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.384-388
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• 2000

일반적으로 흡착분리공정 기술개발은 대략 3단계의 과정을 거치게 되는데 흡착제의 선정, 흡착탑의 거동해석, 연속공정 구성 및 운전으로 이루어진다. 이중 흡착제의 선정은 대상 혼합물에 어떤 흡착제를 사용하여 효율적인 분리 결과를 얻을 수 있는가를 결정하는 기초단계이면서도 가장 중요한 과정이다. 이를 위해 여러 흡착제에 대한 흡착평형량과 이로부터 얻어지는 선택도, 흡착열, 그리고 흡착질과 흡착제 사이의 물질전달저항과 흡착제의 기공 분포도, 기공부피, 기공율, 비표면적, 충전 밀도(Bulk Density), 파쇄 강도 및 마모저항 등과 같은 물리적 특성을 종합적으로 비교 검토하여 흡착제를 선택하여야 한다. (중략)

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.112.1-112.1
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.56-57
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• 1990

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.197-197
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• 2011

고온 스퍼터 공정과 구리 리플로우 공정을 통해 다공성 니켈 지지체에 팔라듐-구리-니켈 삼원계 합금 수소 분리막을 제조하였다. 그러나 스퍼터와 같은 물리적 증착법은 주로 주상정 형태로 증착되기 때문에 다공성 니켈 지지체 표면의 수마이크론 내외의 기공이 존재할 경우 다공성 니켈 지지체에 기인한 많은 기공들 때문에 스퍼터 증착에 영향을 주어 수소 분리막 표면에 기공들이 존재하게 된다. 이를 방지하고 균일한 증착이 이루어지도록 다공성 지지체 표면의 전처리 공정이 필요하다. 본 연구에서는 스퍼터 코팅에 의한 균일한 팔라듐 금속층 형성하고 표면에 미세기공이 없는 수소 분리막을 제조하기 위해 다공성 니켈 지지체를 니켈도금, 알루미나 분말 주입 및 미세연마 전처리 공정을 통하여 다공성 니켈 지지체의 표면기공들을 매립하여 치밀한 팔라듐 합금 층을 형성하였다. 전처리를 하지 않은 다공성 니켈 지지체는 팔라듐 및 구리의 고온 스퍼터 증착 및 구리 리플로우 공정에 의해 표면 기공을 막을 수가 없었고 수소분리기능이 없어 수소 분리막으로 역할을 하지 못했다. Al2O3 분말 주입 전처리 공정을 한 다공성 니켈 지지체에 팔라듐 및 구리 고온 스퍼터 증착과 구리 리플로우 공정을 이용하여 제조된 수소 분리막은 다공성 니켈 지지체에 기인한 기공을 메우기 위해서 팔라듐 합금 층이 두꺼워지는 어려움이 있었다. 니켈도금 전처리 공정을 한 다공성 니켈 지지체에 형성한 수소 분리막은 우수한 선택도를 가졌으나 도금 전처리에 사용된 $2{\mu}m$ 두께의 니켈층이 수소의 확산을 방해하는 저항막 역할을 하여 수소 투과도가 3.96 $ml{\cdot}cm-2{\cdot}min-1{\cdot}atm-1$으로 낮게 나타났다. 미세연마 전처리 공정을 한 다공성 니켈 지지체에 형성한 수소 분리막 역시 우수한 수소 선택도를 가졌으며, 수소의 확산을 방해하는 저항막이 존재하지 않아 13.2 $ml{\cdot}cm-2{\cdot}min-1{\cdot}atm-1$의 우수한 수소 투과도를 나타내었다.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.80-88
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• 1984

The removal mechanism of air borne methyl iodide by triethylenediamine (TEDA) impregnated charcoal bed was investigated. The analysis of experimental data indicates that pore diffusion is the rate controlling step when the air velocity is over 20cm/sec, and both fore diffusion resistance and external mass transfer resistance are contributed to the overall resistance when the air velocity is 10cm/sec. The adsorption model to describe the performance of impregnated charcoal bed under dry condition where water vapors do not exist in air, is proposed. The calculated values and experimental results are well matched.

• Korean Journal of Materials Research
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• v.7 no.12
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• pp.1097-1104
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• 1997

인산형 연료전지(PAFC)용 전해질 매트릭스의 표면 거칠기를 감소시켜 분극저항을 줄이고 작업성을 향상시키기 위해 SiC whisker를 사용하여 일반적인 테이프 캐스팅법으로 제조된 매트릭스의 거친 표면을 평탄화 처리하였다. 구형 입자의 분무공정을 이용하여 표면 평탄화 처리(process l)하는 경우와 롤링을 이용하여 표면 평탄화 처리(process 2)하는 두가지 공정을시도하였으며, 두가지 공정 모두 기공율과 인산 함침도를 유지시키면서, 매트릭스의 표면 거칠기를 감소시키고 기공압, 가소성 및 인장강도를 향상시킬 수 있었다. 위와 같이 제조한 매트릭스로 연료전지를 구성하여 교류 임피던스 분석을 한 결과, 표면 평탄화 처리는 매트릭스 표면의 거칠기를 감소시킴으로써 전극과의 접촉시 계면에서의 분극 저항을 감소시켜 전지성능을 향상시키는 것으로 나타났다. process 2는 표면의 거칠기 감소뿐 아니라 표면에서의 인산함침도가 커서 가장 우수한 전지특성을 나타내었으며, process 1은 매트릭스 표면에 불규칙하게 존재하는 거대 기공을 완전히 제거하고 기공압을 크게 향상시킬 수 있기 때문에 대형의 매트릭스 제조를 가능하게 하였다.