• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.151-158
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• 2022

In this paper, parameter characteristics such as pH effect, isotherm, kinetic and thermodynamic parameters and competitive adsorption of dyes including malachite green (MG), direct red 81 (DR 81) and thioflavin S (TS), which have different functional groups, being adsorbed onto activated carbon were investigated. Langmuir, Freundlich and Temkin isotherm models were employed to find the adsorption mechanism. Effectiveness of adsorption treatment of three dyes by activated carbon were confirmed by the Langmuir dimensionless separation factor. The mechanism was found to be a physical adsorption which can be verified through the adsorption heat calculated by Temkin equation. The adsorption kinetics followed the pseudo second order and the rate limiting step was intra-particle diffusion. The positive enthalpy and entropy changes showed an endothermic reaction and increased disorder via adsorption at the S-L interface, respectively. For each dye molecule, negative Gibbs free energy increased with the temperature, which means that the process is spontaneous. In the binary component system, it was found that the same functional groups of the dye could interfere with the mutual adsorption, and different functional groups did not significantly affect the adsorption. In the ternary component system, the adsorption for MG lowered a bit, likely to be disturbed by the other dyes meanwhile DR 81 and TS were to be positively affected by the presence of MG, thus resulting in much higher adsorption.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.2
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• pp.101-108
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• 1982

In this paper the result of heat transfer analysis around the square heat source of interior solid by using the F. E. M is reported. Calculation for temperature distribution and each element was used by F. E. M. the solid is sub-divided into system of equal size triangular shape. These values of temperature distribution will valuable for design of jet engine and steam generator and the results gained are as follow; 1. Calculation by F. E. M is identified with the experiment. 2. Temperature distribution on the horizontal surface is $\theta$=0.698 in model 4 and the other hand $\theta$=0.401 in model 6 for X=16cm. In intermediates surface between heat source and bottom surface, the influence of L is more greater than that of height in the temperature difference. 3. Temperature distribution on the vertical surface for model 2 is resulted strong influence by K. In the case of Y=4cm is identified with $\theta$=0.0790 for K=7 and also $\theta$=0.0036 for K=0.3. In the difference of temperature distribution.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.1
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• pp.14-19
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• 2023

In summer, the natural ventilation performance for varying greenhouse width is very important in the glasshouses for year round cultivation. The effect of the side openings and greenhouse width on natural ventilation performance was analyzed by simulation. The necessary ventilation rate with different solar radiation transmittance increased significantly when the outside temperature grows higher. The necessary ventilation rate of 40% transmittance was about half of that of 90% transmittance. In consequence, shading effect on temperature control in greenhouse is significant in summer. When the total area of the openings for ventilation is constant, the maximum ventilation rate happens when the area of roof openings is equal to the area of side openings. This maximum ventilation rate is about 3 times of that of the greenhouse with roof openings and without side openings. Therefore, the side openings are advantageous to improve the natural ventilation in greenhouses. As the greenhouse width increases, the influence of side openings on the ventilation rate is becoming smaller. If the natural ventilation rate of the greenhouse with roof and side openings is to become double of that of the roof openings only, the width should be narrower than 38.4m for the Venlo type and 64m for Wide span type.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.47-47
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• 2022

단자엽식물은 잎의 곡선과 직선의 조화가 아름다워 관상용으로 가치가 높은 식물이다. 이로 인해 자생 단자엽식물의 실내 관상 및 조경용 소재개발 연구가 활성화되고 있으나 재배에 대한 정보는 미비한 실정이다. 본 연구에서는 국내 자생 단자엽식물인 참김의털[Festuca ovina L. var. coreana (St.-Yves) St.-Yves], 청사초(Carex breviculmis R.Br.), 골풀[Juncus decipiens (Buchenau) Nakai]을 대상으로 몇 가지 재배 조건에 대한 생육 차이를 확인하였다. 국립생물자원관으로부터 분양 받은 세 종의 종자는 휴면 여부와 발아 적온을 확인하기 위해 종자를 페트리디쉬에 파종한 후 15, 20, 25, 30℃(명 또는 암조건) 및 25/15℃(16/8h, 명/암) 조건에 배치하였다. 재배실험은 유리온실에서 수행되었으며, 토양에 파종 후 4주간 육묘한 다음 균일한 생육상태의 묘를 7cm 포트에 이식하여 실험의 재료로 사용하였다. 토양실험은 시판 원예용상토와 마사토를 혼합하여 사용하였으며, 비율을 1:1, 2:1 및 3:1로 조성하였다. 차광 환경은 55, 75% 차광과 무차광 조건으로 달리 하였으며, 추비는 재배 6, 8, 10주차에 500, 1,000ppm의 하이포넥스(NPK 7-10-6) 용액을 엽면시비 하였다. 토양실험을 제외한 모든처리구에서는 원예상토 단용을 사용하였으며, 이식 후 12주간 재배하였다. 발아 실험 결과, 참김의털은 명조건에서 25/15와 15℃를 제외하고 발아율이 10% 이하로 조사되었으며, 암조건에서 온도가 증가할수록 발아율이 감소하였다. 청사초는 모든 온도에서 90%이상 발아하였으며, 암조건의 경우 발아율이 10% 이하로 조사되어 광발아성 종자로 확인되었다. 골풀은 실험이 진행된 30일 동안 모든온도에서 발아하지 않았으나, 재배실험을 위해 토양에 파종된 골풀은 파종 약3주 이후 발아가 관찰되었다. 재배실험 결과, 참김의털과 청사초의 경우 2:1로 혼합한 토양에서 엽수와 분얼수, 생체중 등이 가장 높게 조사되어 관상적 가치가 높았으며, 골풀은 3:1의 혼합토양에서 생육이 가장 우수하였다. 차광은 세 종 모두에게서 생육에 부정적인 영향을 미쳤으며, 청사초와 골풀은 500ppm의 하이포넥스를 시비하였을 때 생육이 촉진되었다.

• Solar Energy
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• v.17 no.2
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• pp.35-42
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• 1997

Thermal diode is a device which allows heat to be transferred in one direction by convection due to difference of density of fluid, and blocks heat flow in the opposite direction. Vertical plate for heat collection and radiation are of utility for design of thermal diode. It was considered the transient and steady state of air filled thermal diode with guide vane which combined rectangular and parallelogrammic shape enclosures. $Gr^*$ was kept constantly on $1.11{\times}10^{10}{\sim}1.4{\times}10^{10}$ and error range was ${\pm}3%$ during the experiment. Nu was examined when inclined angle are $15^{\cir\c}\;and\;45^{\circ}$ and, also the experiments was carried out with and without guide vane as well. Specially, Nu was linearly increased due to increase of $Gr^*$, and the effect of guide vane and dimensionless channel depth was sensitive. Developed state of temperature began at dimensionless time $0.5{\sim}0.6$ due to variation of inclined angle, which is characteristic of system.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.18-18
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• 2011

본 연구는 태양초 품질에 미치는 후숙방법과 산광재료의 효과를 구명하기 위하여 2011년 8월부터 2011년 9월 25일까지 충청북도농업기술원 1중 플라스틱 하우스에서 수행하였다. 전처리 방법은 고추 수확 후 벌크(대조구), 하우스 밀봉, 비닐밀봉 등 3처리를 하였으며, 산광재료는 관행(무차광, 대조구), 차광망(35%), 천막지, 백색부직포, 흑색부직포를 건조대 위의 멀칭용 철사에 고정하여 실험을 수행하였다. 고추건조대($6{\times}1.5{\times}0.75(m)$, $L{\times}W{\times}H$)를 각 앵글로 설치하고, 고추 건조기의 건조 깔판을 깔고 고추를 널어 건조하였다. 플라스틱하우스 바닥에는 천막지를 깔고 토양으로부터 습기를 차단하여 고추 건조를 촉진코자 하였다. 고추 전처리 방법은 벌크 건조가 건조기간이 짧고 비상품과율이 낮아 건조 효율이 우수하였으나, 태양초 생산을 위한 전처리 방법으로는 하우스 밀봉이 우수하였다. 산광재료는 백색부직포 처리시 고추의 수분 증발 속도가 대조구보다 뒤졌으나, 다른 처리보다 온도가 높아 건조기간을 단축할 수 있었고, 색택이 우수할 뿐만아니라 상품성도 우수하였다.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.291-297
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• 2000

This study was conducted to find out the environmental factors affecting the differences in the half-life of the insecticide cyfluthrin in soil between field and laboratory tests carried out in 1998. Degradation and leaching of cyfluthrin in soil were examined under various environmental conditions that were considered to affect the residuality. Cyfluthrin was degraded 1.9 times faster in non-sterilized soil than in sterilized soil and 1.2 times at $25^{\circ}C$ than at $15^{\circ}C$. The half-lives of cyfluthrin were 61.4 days under the dark condition and 4.5 days under sunlight, and those were 11.8 days under the open condition and 23.8 days under the closed condition. The half-lives of the authentic compound and the commercial product of cyfluthrin were 15 and 1 day in the field test and 26 and 3 days in the laboratory test, respectively. Cyfluthrin was rapidly degraded with an increase in soil moisture content and decomposed faster in the alkaline solution of pH 12 than in the acidic solution of pH 3, but the half-life of cyfluthrin did not make any difference between pH 6.4 of the field test soil and pH 5.6 of the laboratory test soil. Cyfluthrin was immobile in soil from the results that $81{\sim}94%$ of the initial amount remained in the $0{\sim}2\;cm$ layer of the soil column regardless of the amount and time of rainfall after the chemical treatments. From viewing the abovementioned results, soil moisture content, sunlight and formulation type affected greatly soil microbes and volatilization affected slightly, and temperature, pH and rainfall did not affect the big difference in the half-life of cyfluthrin in soil between the field and laboratory tests in the year of 1998.