• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.161-170
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• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated pig slurry on growth of pepper in substrate hyrdoponic culture. In process of composting, compost leachate was was through a saturated compost heap. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. The pig slurry was mixed with chemical nutrient solution and byproduct based on nitrogen content. Peppers were grown in the seven different hydroponic solutions; compost leachate (CL), concentrated pig slurry (CS), compost leachate + byproduct (CL+BP), concentrated pig slurry + byproduct (CS+BP), compost leachate 50% + nutrient solution 50% (CL+NS), concentrated pig slurry 50% + nutrient solution 50% (CS+NS) and chemical nutrient solution for pepper. The chemical nutrient solution was the standard solution of National Horticulture Research Station for the growth of pepper. The concentration of nutrient solution was adjusted $1.6{\sim}2.0mS/cm$ in EC. The compost leachate and concentrated pig slurry were low in phosphorus (P), calcium (Ca), magnesium (Mg), but rich in potassium (K). Growth characteristics as affected by the different nutrient solution were significantly different. Growth and fruit characteristics treated with CL 50+NS 50%CS and 50+NS 50% were similar with NS 100% control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 50%+NS 50%, respectively. The fruit of pepper showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of pepper severely decreased after application of 100% CS treatment. The yield of pepper was not significantly different between the plots treated with mixture of CS50 + NS50% and 100% nutrient solution treatment. Fruit yield of the compost leachate concentrated pig slurry plot were 59, 14% compared to control, repectively. In conclusion, the mixture solution of 50% of pig slurry and 50% of nutrient solution could be used as a nutrition solution of pepper in hydroponic culture.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.235-242
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• 2018

BACKGROUND: About 81% of nitrous oxide ($N_2O$) emissions from agricultural land to the atmosphere is due to nitrogen (N) fertilizer application. Mitigation of $N_2O$ emissions can be more effective in controlling biochemical processes such as nitrification and denitrification in the soil rather than decreasing fertilizer application. The use of urease inhibitors is an effective way to improve N fertilizer efficiency and reduce $N_2O$ emissions. Several compounds act as urease inhibitors, but N-(n-butyl) thiophosphoric triamide (NBPT) has been used worldwide. METHODS AND RESULTS: Hot pepper and chinese cabbage were cultivated in five treatments: standard fertilizer of nitrogen-phosphorus-potassium(N-P-K, $N-P_2O_5-K_2O$: 22.5-11.2-14.9 kg/ha for hot pepper and $N-P_2O_5-K_2O$: 32.0-7.8-19.8 kg/ha for chinese cabbage), no fertilizer, and NBPT-treated fertilizer of 0.5, 1.0, and 2.0 times of nitrogen basal application rate of the standard fertilizer, respectively in Gyeonggi-do Hwaseong-si for 2 years(2015-2016). According to application of NBPT-treated fertilizer in hot pepper and chinese cabbage, $N_2O$ emission decreased by 19-20% compared to that of the standard fertilizer plot. CONCLUSION: NBPT-treated fertilizer proved that $N_2O$ emissions decreased statistically significant in the same growth conditions as the standard fertilization in the hot pepper and chinese cabbage cultivated fields. It means that NBPT-treated fertilizer can be applied for N fertilizer efficiency and $N_2O$ emissions reduction.

• Membrane Journal
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• v.27 no.3
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• pp.205-215
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• 2017

Polymer membranes are cheap and easy in fabrication, and show a high permeability and selectivity, thus play pivotal roles in gas separation as well as water purification. However, polymer membranes typically exhibit the trade-off relation between permeability and selectivity; i.e. when the permeability is high, the selectivity is low and vice versa. Facilitated transport has been considered one of the solutions to address this issue. Over the last decades, facilitated transport concept had played an important role in preparing the membranes and providing ideal and various models for the transport. Understanding the nature of carrier, the mobility of matrix and the physico-chemical properties of polymer composites are crucial for facilitated transport. Depending on the mobility of carrier, facilitated transport membrane is classified into three; mobile carrier membrane, semi-mobile carrier membrane, fixed-site carrier membrane. Also, there are four types of reversible reaction between the carrier and the specific target; proton transfer reaction, nucleophilic addition reaction, p-complexation reaction and electrochemical reaction. The facilitated transport membranes have been applied in the separation of CO2, O2 and olefin (propylene or ethylene). In this review, major challenges surrounding facilitated transport membranes and the strategies to tackle these challenges are given in detail.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.999-1005
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• 1996

Pt catalyst on carbon black was prepared by colloidal method, ion exchanging method and methanol reducing method. The colloidal method has been used generally. At ion exchanging method, $H^+$ of functional group on carbon surface made by oxidation treatment was exchanged with Pt ion. At methanol reducing method, Pt was impregnated on carbon to reduce by methanol contained with surfactants. With TEM and XRD, Pt particle size impregnated on carbon by various methods was $30{\sim}50{\AA}$. Loading yield was about 100%, loading yield of ion exchanging method was 99.92% by DCP analysis and 99.87% by combustion method. Within 60 hour, current density of oxygen reduction was $460mA/cm^2$ at 0.7V(vs. RHE) at colloidal method. It was the better performance than catalyst prepared by ion exchanging, methanol reducing method. But, it was shown some decrease of performance for long operation time(after 100hour), catalyst prepared by methanol reducing method was shown stable performance.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.7-17
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• 2014

Molten salt electrorefining process achieves uranium deposits at cathode using an electrochemical processing of spent nuclear fuel. In order to recover pure uranium from cathode deposit containing about 30wt% salt, the adhered salt should be removed by cathode process (CP). The CP has been regarded as one of the bottle-neck of the pyroprocess as the large amount of uranium is treated in this step and the operation parameters are crucial to determine the final purity of the product. Currently, related research activities are mainly based on experiments consequently it is hard to observe processing variables such as temperature, pressure and salt gas behavior during the operation of the cathode process. Hence, in this study operation procedure of cathode process is numerically described by using appropriate mathematical model. The key parameters of this research are the amount of evaporation at the distillation part, diffusion coefficient of gas phase salt in cathode processor and phase change rate at condensation part. Each of these conditions were composed by Hertz-Langmuir equation, Chapman-Enskog theory, and interphase mass flow application in ANSYS-CFX. And physical properties of salt were taken from the data base in HSC Chemistry. In this study, calculation results on the salt gas behavior and optimal operating condition are discussed. The numerical analysis results could be used to closely understand the physical phenomenon during CP and for further scale up to commercial level.

• Journal of Sericultural and Entomological Science
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• v.24 no.2
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• pp.55-72
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• 1983

These studies were done to find out any difference, ultrastructural, physical or chemical, between the shells of diapausing and non-diapausing eggs of the silkworm, Bombyx mori L. 1. From the electron-microscopic observation, the egg shells have four distinctive layers. In addition to the four layers, the shells in the diapausing eggs has another layer with low electron density on its surface. 2. The permeability of the egg shell to hydrochloride was much lower in diapausing egg than in non-diapausing egg. Also the permeability changed in the opposite directions with the egg age: the diapausing eggs decreased while non-diapausing ones increased. 3. The permeability increased when the diapausing egg shell was treated with HCl. When they were treated with ether, however, the increase in permeability was much smaller. It seems there was an ether soluble material involved in the content of the egg shell. 4. The diapausing eggs were also much more resistant to desiccation than the non-diapausing ones. The former, when treated with HCl or chilling, became less resistant to desiccation. 5. The positive histochemical response of the egg shell to PAS-Alcian blue and protein stainings suggests presence of abundant proteins and carbohydrates in the egg shell. On the other hand, the staining response to lipid was more positive in the inner layers than in the outer layer of the shell. 6. The egg shell adhesives seems to be mucopolysaccharides produced by colleterial glands, since the oviposited eggs showed a positive responses to carbohydrate and negative to lipid-staining chemicals, but not the mature oocytes in the ovarioles. 7. There were two bands on the electrophoretic pattern of the SH proteins extracted from the egg shells both in the diapausing egg and non-diapausing one: a slow moving major component and a fast moving minor one. However, the electrophoretic mobility showed a difference in the minor components between them. It is evident that the fast moving minor one of non-diapausing egg ran a little further than that of diapausing egg. 8. In amino acids analysis, no significant differences were found in their composition between diapausing and non-diapausing egg and SH proteins contain relatively more glycine and less cystine.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.131-131
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• 2016

기원전 5000년 이집트에서부터 시작된 도금은 시간이 지남에 따라 점점 발전하여, 1900년대에 들어 전기를 이용한 도금공정이 개발되었고, 현재 뿌리산업으로써 각종 제조업에 널리 이용되고 있다. 도금 공정은 금속을 부식으로부터 보호하고, 제품의 심미성과 기능성, 생산성 등을 높이기 위해 주로 이용된다. 전주도금 공정은 완벽하게 동일한 형태의 생산품을 다량으로 제작 할 수 있기 때문에, 그 높은 생산성으로 주목 받고 있다. 특히, 나노/마이크로 크기의 정밀 소자 등을 가공하는 차세대 기술인 LIGA공정과 접목이 가능하다는 장점이 있다. 몰드를 이용하여 복제하는 방식인 전주 도금은 도금공정이 끝난 후 몰드와 완성된 제품을 분리해내는 추가공정이 필연적으로 발생하게 되는데, 둘 사이의 접착력을 낮추기 위하여 몰드의 표면에 이형박리제를 도포하게 된다. 이형박리제로는 전기가 잘 흐르면서 접착력이 낮은 이산화 셀렌이나 중크롬산이 주로 이용되지만, 원활한 박리를 위해서는 그 두께가 30 um 이상 확보되어야 하기 때문에 정밀한 미세구조 전주도금이 어렵다는 문제점이 있다. 또한 이와 같은 화학 약품들은 매우 유독하기 때문에 추가적인 폐수 처리 공정이 필요하며, 작업자의 안전을 위협하고 심각한 환경 오염을 초래한다는 추가적인 문제가 발생한다. 따라서, 매우 얇고 친 환경적이며 안전한 전주도금 이형박리제에 대한 연구가 요구되고 있다. 본 연구에서는 전주도금 몰드로 사용한 구리의 표면에 TCVD를 이용하여 단일 층 그래핀을 성장시킨 후, 그래핀이 코팅된 몰드에 구리를 전주도금하여 박리하였다. 박리 후 그래핀은 몰드에 손상 없이 남아있는 것을 Raman microscopy를 통해서 확인하였고, 몰드와 그래핀 사이의 접착력 (약 $0.71J/m^2$)에 비해 그래핀과 전주도금 샘플간에 낮은 접착력 (약 $0.52J/m^2$)을 갖는 것을 확인하였다. 이와 같이 낮은 접착력을 통해 박리 시 표면구조의 손상 없이 정밀한 구조의 미세 패턴구조를 형성할 수 있었다. 전주도금을 이용한 전극 형성과 고분자와의 융합을 통해 유연기판을 제작하여 bending 실험을 진행하였다. $90^{\circ}$의 bending 각도로 10000회 이하에서는 저항의 변화가 없었고, LED chip을 mounting한 후 곡률반경 4.5 mm까지 bending을 진행하여도 이상 없이 LED가 발광하는 것을 확인하였다. 위와 같은 전주도금 공정을 이용하여 고집적 전자기기, 광학기기, 센서기기 등의 다양한 어플리케이션의 부품제조에 활용될 수 있을 것으로 기대한다.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04a
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• pp.33-33
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• 1999

고지 사용율을 증가시킴으로써 원가 절감을 모색하고 있는 국내 신문용지 생산업체에서 는 보류도와 탈수성 저하에 따른 생산성 악화가 발생하고 있을 뿐 아니라 제품의 강도 및 인쇄적성 저하라는 문제를 극복하는 것이 매우 중요한 과제로 대두되고 있다. 또 신문용지 생산공정의 수질이 악화됨에 따라서 사용되는 화학첨가제의 효능이 크게 감소하는 문제를 지니고 있다. 적합한 양성전분과 이러한 문제를 종합적으로 해결하기 위한 방안으로 신문용지 생산에 이의 적용기술을 모색하였다. 전기전도도가 4000 $\mu\textrm{s}$/cm인 신문용지 지료를 이용하여 DS 0.03인 저치환 양성 전분의 보류도 증가효과를 평가한 결과 양성전분을 사용하지 않은 경우에 비하여 보류도 증가율이 6 6%로 낮게 나타났으나, DS 0.06인 전분은 보류도 증가율이 21%로 향상효과가 높게 나타났 다. 또 양성전분의 치환도가 증가할수록 인장지수, 내부결합강도, 표면강도 향상 효과도 증 가되는 결과를 얻을 수 있었다. 가교 처리를 실시한 치환도 0.08 및 0.1의 습식양성전분의 경우에는 미세분 보류도, 여수도, 탁도 등에 큰 효과를 나타내지 않았다. 경우 보류도가 각 확인하였으며,이 건식방법으로 제조된 치환도 0.08 빛 0.15인 양성 전분을 0.5% 첨가할 각 16%, 21% 증가되어 적은 첨가량에서도 보류향상 효과가 높다는 것을 러한 효과는 여수도 및 양이온 요구량 측정을 통하여 재확인되었다. 저치환 양성전분의 성능을 개선시키기 위한 방법으로서 비이온성 천연고분자를 활용하 는 방안을 검토한 결과 비이온성 천연고분자를 병용함에 따라 보류도 증가율이 탁월하게 개 선되었으며, 인장지수, 내부결합강도, 표면강도 등에서도 같은 효과를 얻을 수 있었다.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.335-340
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• 1986

Two kind of ${\beta}-glucosidase$, tightly-bound enzyme(TBE) and loosely-bound enzyme(LBE), were obtained from the conidia of Aspergillus nidulans. The existence of enzymes in conidia was conformed by the fact that these enzyme activities were proportional to the number of conidia. The levels of enzyme activities were independent of aging of the conidia. Enzymes were characterized partially. In spite of the physical and chemical treatments of conidia, there was no significant change in TBE activity. The optimum pH and temperature was 6.0 and $55^{\circ}C$, respectively. Thermostability of the TBE was remarkably higher than that of mycelial ${\beta}-glucosidase$. The electrophoretic pattern of LBE was identical to that of mycelial ${\beta}-glucosidase$. These results suggest that conidial ${\beta}-glucosidase$ are involved in adaptation process of the conidia to variable environments.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.519-524
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• 2019

Even though stainless steel foil is not a highly efficient material for film-type solar cell, it has strong passivation capability without additional process. In this study, silicone resin was employed during a-Si:H thin film solar cell fabrication for the purpose of planarization and electrical insulation. In the first stage of process, silicone resin was coat onto the stainless steel (STS) using spin coater with thickness of $2{\sim}3{\mu}m$ and followed by aluminum deposition using ion beam application. Unexpectedly buckling was formed during aluminum deposition process. After subsequent fabrication processes, solar cell performance was evaluated. In voltage-current data, slight increase of cell performance was obtained and interpreted by the increase of light scattering.