• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.407-407
• /
• 2008

무기EL 디스플레이는 고체재료에 전계를 가했을 때 발광하는 현상을 이용한소자로서, 급속도로 발전을 거듭하고 있으나, 유전체층에 강한전계를 가하여 발광하여야 하므로 낮은 Breakdown voltage와 효율의 한계로 인하여 휘도가 낮고 풀 컬러화 디스플레이 등 의 응용에는 적용되고 있지 못하는 실정이다. 본 연구에서는 강유전체 Perovskite 구조를 가지는 ABO3 물질 중 PMN(Lead Magnesium niobate) 과 PZT (Lead Zirconate titanate) 후막을 제조하여 Inorganic EL(Electro Luminance)에 적용하고 소자의 광전특성을 평가하였다. 소자에 사용된 기판은 고온소성에 알맞은 알루미나(Al2O3)기판을 채택 하였으며, 그 위 하부전극으로는 고온소성에 따른 화학적 안정성이 우수한 Au전극을 Screen Printing 하였다. 제조 되어진 PMN후막 페이스트는 PMN(Pb(Mg1/2 Nb2/3)O3) + Glass Frit(Pb-Zn-B) + BaTiO3(99.99%) 로 합성되었으며 하부전극위에 인쇄하였다. 그 다음 PZT sol-gel을 Spin coating으로 도포 하였다. 형광체로 ZnS:Cu.Cl 을 Screen Printing을로 형성하였으며, 평탄화를 위하여 유기물 충을 Screen Printing 공정으로 성막 하였다. 상부전극으로는 DC sputter로 ITO를 증착하여 EL소자 완성 후 Spectro - Chroma meter로 소자특성을 측정하였다. 평탄화를 통한 유기물층에 변화되는 Capacitance를 Oscilloscope로 전압 전류 pulse의 변화에 따른 opto-electronic 특성을 평가하였다.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.3
• /
• pp.9-15
• /
• 2005

Soil aquifer treatment is a water reuse technology that secondary or tertiary treated wastewater is infiltrated into the aquifer in which physical and biochemical reactions occur. Major consideration in SAT is the removal and transport of DOC and nitrogen species. In this study, reaction mechanism in SAT was examined considering nitrification, denitrification and organic oxidation. In addition, SAT modeling system was developed as the reaction mechanism was applied to groundwater flow and transport model. In verification of the reaction module by 1-dimensional unsaturated soil column test, the experimental data of all of the species, ammonium, nitrate, DOC and DO, were well matched with the simulation results. In sensitivity analysis, ammonium partition coefficient, dissolved oxygen inhibition constant and biomass decay rate affect ammonium, DOC and DO concentration of effluent, respectively.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.302-302
• /
• 2009

유기농업에서 유기물은 양분의 공급, 토양의 이화학성 개선, 토양의 생물학적 건전성 유지 등 중요한 역할을 한다. 토양의 생물학적 건전성은 토양의 생태계적 기능을 지속적으로 유지시키는 토양미생물이 관여하고 있다. 따라서 본 연구는 유기물의 장기연용에 따른 밭토양 미생물의 다양성을 비교 분석하였다. 여러 가지 유기자원을 동일한 기준으로 매년 동일 장소에 처리하였다. 사용된 유기자원은 가축분퇴비, 채종유박인 유기질비료, 볏짚으로만 퇴비화한 볏짚퇴비와 겨울철 휴한기에 헤어리베치를 재배하여 이듬해 봄에 예취한 후 토양에 환원한 녹비처리구, NPK구, 가축분퇴비를 혼용처리한 NPK퇴비군, 양분을 전혀 시용하지 않은 무비구 등 총 7처리구였다. 각각의 처리구에서 토양(0-20 cm)을 채취하여 배양성 토양미생물은 희석평판법으로 해당 선백배지에 시료를 도말 하여 조사하였고 비배양성 미생물은 토양으로부터 genomic DNA를 추출하여 세균의 16S rDNA를 증폭시킨 후 denaturing gradient gel electrophoresis (DGGE)를 수행하여 분석하였다. 주요결과를 요약하면 밭토양에 서식하는 토양미생물의 균수는 처리별간의 차이를 보였으며 유기물처리구가 화학비료처리구보다 높았다. DGGE 분석을 통해 유기물 처리에 따른 군집의 다양성을 살펴본 결과 Fig. 1에서 보는바와 같이 Gel 상에서 다양한 위치의 밴드를 확인할 수 있었고 처리별로 특이 밴드가 있음을 확인할 수 있었다. Fig. 1에서 얻은 DGGE profile상의 밴드 강도와 수를 비교하여 Fig 2와 같은 dendrogram을 나타낼 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.380-384
• /
• 2016

홍수완화의 관점에서 강을 관리하기 위하여 수자원의 이용과 생태계보전, 하천흐름과 형태학적 변화들에 대하여 충분히 이해하고 합리적으로 설명하는 것이 필요하다. 최근에 수변지역에서 발달된 식생은 홍수시에 감속영역과 생물들의 피난처를 제공하는 것 이외에 횡단방향의 혼합작용을 활성화하여 유사와 식물의 씨앗 및 입자성 유기물(POM)을 포착하는 기능을 하고 특히 흐름과 유사이송 및 하도 지형변화에 큰 영향을 주기 때문에 중요하다. 입자성 유기물(POM)은 하천생태계를 지탱하는 에너지원으로서 다양한 형태로 존재하고 미생물의 분해를 받아 무기화된 식생의 번무와 물질순환의 시발점이 되기도 하지만 현재까지 식생영역 내에서 그 공급과정에 관련이 있는 운동기구에 관한 연구는 아직 부족한 실정이다. 따라서 본 연구는 식생영역의 유사퇴적 및 분급작용, 입자성 유기물의 포착을 일으키는 원인과 흐름의 특징 중 식생영역 내에서 흐름방향으로 감속에 주목하여 수리 모형실험을 실시하였고 수변식생에서 부유사와 POM의 퇴적과정에 대하여 검토 및 모델링을 실시하였다. 수리 모형실험 결과 CPOM과 FPOM 모두 유사의 퇴적없이 그 자체로는 퇴적이 되지 않았고 수변식생의 종방향 이송의 경우 식생에 의해 퇴적된 부유사가 사련 형태로 형성이 되어 CPOM이 사련의 배후에서 캡쳐 되었다. 또한 두가지 샘플 움직임의 상호작용은 사련의 파고와 파장의 전파속도를 감소시켰다. 식생지역에서 횡방향 분산의 경우에 대해서는 각각의 유사 크기에 대한 퇴적물의 능선은 식생의 경계를 따라 형성되었고 운동의 범위는 유사 퇴적의 능선에 의해 촉진되어 횡방향으로 확산하며 확장되었다. 이러한 결과를 바탕으로 제한된 경험적인 지식보다 오히려 실험을 통하여 식생을 동반하는 장소에서 유사와 POM의 거동특성 차이 및 간섭작용을 명확히 한 후 현장에서 관측된 현상과 비교 검증이 필요하다고 사료되며 추후에 운동기구를 모델링 및 업그레이드 해 나가는 것이 앞으로의 하천생태계 예측평가에 필요하다고 판단된다.

• Journal of Applied Biological Chemistry
• /
• v.63 no.4
• /
• pp.401-406
• /
• 2020

The plant uptake of endosulfan, a new persistent organic pollutants from soil environment was investigated on ginseng through the field survey in Korea. The endosulfan residues in soil for this survey were ranged on 0.013-0.136 mg kg-1. The plant uptake factor (PUF) for endosulfan in ginseng was 0.243-1.708 and the highest PUF was found on 3-year-old ginseng. The PUF for endosulfan decreased in the longer cultivation period and it might be caused by the dilution effect of ginseng growth. In addition, the soil organic matter (SOM) content affected on the PUF negatively and Pearson correlation coefficient (r) between SOM and PUF was -0.7812 (p <0.05). Thus, higher SOM would positively affect to reduce the endosulfan residue in ginseng root.

• Korean Chemical Engineering Research
• /
• v.60 no.4
• /
• pp.486-491
• /
• 2022

A benthic microbial fuel cell (BMFC) is an eco-friendly energy conversion device that uses electricity generated by benthic microorganisms decomposing organic matter in the mud of the sea or lake. In this study, in order to understand how domestic wastewater flowing into tidal flats affects the performance of BMFC. BMFC performance was compared and reviewed by fermenting organic substances in food and mixing them with tidal flats. Performance of the BMFC was improved by 49% by adding fermented food rich in vitamins (B₂, B₆, B₁₂, C, D, E) and soft flour. The maximum power density increased as the amount of fermented organic matter increased, and it was shown that the fermented organic matter fermented during 25~29 days was optimal for BMFC.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.3
• /
• pp.68-77
• /
• 2015

This study was conducted to characterize food waste leachate (FWL) and to compare its characteristics according to generation source: feed supplement- and compost-producing facilities. FWL contained high levels of organic compounds such as carbohydrate, protein and lipid. The moisture content of FWL was among the range of conventional wet anaerobic digestion. FWL was acidic (pH of $4.0{\pm}0.3$) and showed high coefficients of variance for specific parameters: carbohydrate, protein, lipid, ethanol, acetic acid and propionic acid. FWL derived from feed supplement-producing facilities showed slightly lower concentrations of most parameters than FWL derived from compost-producers. However, the difference was not significant at 5% significance level according to analysis of variance.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.5
• /
• pp.748-754
• /
• 2010

The contents of soil organic matter (SOM) and $Al_o+1/2Fe_o$ in soils are important criteria for the classification of new Andisols in Soil Taxonomy system. There are many soil types in Jeju Island with various soil forming environments. This paper was conducted to estimate the contents of soil organic matter and the content of ammonium oxalate extracted Al and Fe ($Al_o+1/2Fe_o$) using various environmental variables and to make soil property maps using a statistical analyses. The soil samples were collected from 321 locations and analyzed to measure the contents of SOM and $Al_o+1/2Fe_o$. It was analyzed the relationships among them and various environmental variables such as temperature, precipitation, net primary product, radiation, evapotranspiration, altitude, soil forming energy, topographic wetness index, elevation, difference surrounded area, and distances from the shore and the peak. We can exclude multi-collinearity among environmental variables with principal component analysis and reduce all the variables to 3 principal components. The contents of SOM and $Al_o+1/2Fe_o$ were estimated by multiple regression models and maps of them were made using the models.

• Applied Biological Chemistry
• /
• v.40 no.2
• /
• pp.128-133
• /
• 1997

This study was conducted to evaluate the adsorption, desorption, leaching and degradation pattern of fungicide fluazinam in the soil environment under the laboratory conditions. The mode of isothermal adsorption of fluazinam in soil was coincident with the Freundlich equation. The adsorption amount of fluazinam was much higher on soils containing organic matter than on soils oxidized with hydrogen peroxide. The presence of organic matter, humic acid or fulvic acid, increased the adsorption amount of fluazinam on soils. The Freundlich constant K was much higher in soil added with humic acid than in soil added with fulvic acid. The desorption ratio of fluazinam adsorbed to soil was increased by removal of organic matter. In leaching experiment using soil column, the fluazinam applied on the soil surface was not moved down to the bottom of soil and was not detected in leachate water. The degradation of fluazinam was faster in Soil I with rich organic matter than Soil II with poor organic matter, in non-sterilized soil than sterilized soil, and in flooded soil than unflooded soil.

• Journal of Animal Environmental Science
• /
• v.13 no.1
• /
• pp.13-20
• /
• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.