위지동이전의 제문제 : 위지동이전에 나타난 제천의식과 가무

양재연 ( Yang Jae Yeon ) 성균관대학교 대동문화연구원 1979 大東文化硏究 Vol.13 No.-

시간 및 온도변화에 따른 폴리아크릴로니트릴/디메틸술폭시드 중합체 용액의 유변학적 특성 연구

양재연 ( Jae-yeon Yang ),이병민 ( Byoung-min Lee ),국윤수 ( Yun-su Kuk ),김병석 ( Byoung-suhk Kim ),서민강 ( Min-kang Seo ) 한국복합재료학회 2019 Composites research Vol.32 No.1

본 연구에서는 PAN 섬유용 폴리아크릴로니트릴(PAN)/디메틸술폭시드(DMSO) 용액의 보관시간 및 온도 변화에 따른 구조적 및 유변학적 특성에 대해 고찰하였다. 결과로서, 모든 PAN/DMSO 용액은 온도 변화에 따라 매우 특징적인 유변학적 거동을 보였다. 중합체 용액은 온도가 40~70oC의 온도 범위까지 증가함에 따라 복합 점도가 증가하고 손실 계수(tanδ)가 감소함을 나타내었으며, 낮은 진동수에서 점도가 급격히 증가하는 것을 확인할 수 있었다. 이러한 결과는 저장 시간에 따라 중합체 용액내 물에 의한 분자간 수소 결합으로 겔 고분자 및 고밀도 겔 구조가 형성되었기 때문으로 판단된다. In this study, the structural and rheological characterizations of polyacrylonitrile(PAN)/dimethyl sulfoxide(DMSO) solutions for PAN fiber were investigated according to the change of storage times and temperatures. As a result, PAN/DMSO solutions exhibited a very characteristic rheological behavior with variation of temperature. The solutions showed an increase of complex viscosity and a decrease of loss tangent(tanδ) as temperature was increased over the temperature range of 40 and 70oC and it could be seen that the viscosity rapidly increased at low frequency. These results indicated that the gel polymer and denser gel structure were formed due to the intermolecular hydrogen bonding of water in the polymer solution depending on the storage time.

석유계 피치가 첨가된 고온 탄소복합재용 페놀수지의 열 유변학적 거동 연구

양재연 ( Jae-yeon Yang ),국윤수 ( Yun-su Kuk ),서민강 ( Min-kang Seo ),김병석 ( Byoung-suhk Kim ) 한국복합재료학회 2020 Composites research Vol.33 No.6

본 연구에서는 각각에 다른 연화점을 갖는 석유계 피치의 열 유변학적 특성을 연구하였으며, 이를 함침용 페놀수지에 석유계 피치를 첨가하여 B-stage 형태의 페놀수지/석유계 피치 혼합물을 제조하였다. 그 결과, 연화점이 다른 석유계 피치는 QI의 함량이 증가할수록 피치의 유동성이 감소하였고, 고체의 점탄성 특성을 나타내었다. 또한, 다른 연화점을 갖는 석유계 피치를 페놀수지에 첨가함으로써, 페놀수지의 경화거동과 열 유변학적 특성에 미치는 영향에 대해 고찰하였을 때, 다른 연화점의 석유계 피치를 첨가함에 따라 페놀수지의 경화속도 및 경화거동을 조절할 수 있었으며, 이 중 P-Pitch 2가 첨가된 페놀수지 혼합물의 경우 동일한 경화 온도조건에서 다른 혼합물에 비해 유동성이 높은 것을 확인할 수 있었다. In this study, the thermo-rheological behaivors of petroleum pitches with different softening points were studied, and a B-stage phenolic resins/petroleum pitches blends were prepared by adding petroleum pitches to the phenolic resins. As a result, the petroleum pitch with different softening points decreased the fluidity of the petroleum pitch as the Quinoline insoluble (QI) content increased and showed the viscous properties of the solid. In addition, the effect of adding petroleum pitches having different softening points on the thermo-rheological properties of phenolic resins was investigated. When petroleum pitch with a high softening point was added, the fluidity of the phenolic resin was reduced, and the hardening behavior was fast. It was possible to control the curing rate and curing behavior of the phenolic resin by adding petroleum pitches of different softening points. Among them, the phenolic resin mixture to which P-Pitch 2 was added has a higher fluidity than other blends under the same curing temperature condition.

전기이중층 커패시터용 탄소 에어로겔 전극의 전기화학적 거동 연구

양재연 ( Jae-yeon Yang ),서민강 ( Min-kang Seo ),김병석 ( Byoung-suhk Kim ) 한국복합재료학회 2020 Composites research Vol.33 No.6

본 연구에서는 헥사 메틸렌 테트라민을 촉매로 사용하여 이소프로판올에서 레소시놀과 퍼푸랄을 졸-겔중축합한 후 이소프로판올 동결 건조 조건에서 유기 겔을 직접 건조시킨 후 질소 분위기에서 탄화시켜 탄소 에어로겔을 제조하였다. 탄소 에어로겔의 제조 조건은 퍼푸랄에 대한 레소시놀의 몰비를 변경하여 조사하였다. 탄소 에어로겔의 기공 구조에 대한 제조조건의 영향은 질소 흡착 등온선에 의해 고찰하였다. 탄소 에어로겔의 특성은 주사전자현미경과 적외선 분광법을 가지고 측정하였다. 전기 이중층 커패시터에서 전극으로서의 탄소 에어로겔의 기공 접근성과 성능을 전기 화학적으로 고찰하였다. 결과적으로 BET 표면적과 비용량은 R/C 비율에 따라 증가하였으며, 765 m²/g 및 132 F/g의 최대 값은 각각 R/C 비율 200에서 달성되었다. 결론적으로 R/C 비율을 높이면 CA 전극의 평균 기공 크기가 증가하여 시스템의 속도 성능이 향상됨을 확인하였다. In this study, carbon aerogels (CA) were prepared by sol-gel polycondensation of resorcinol and furfural in isopropanol using hexamethylenetetramine as a catalyst, and then directly drying the organic gels under isopropanol freeze-drying conditions, followed by carbonization under a nitrogen atmosphere. The preparation conditions of the CA were explored by changing the mole ratio of resorcinol to furfural. The effect of the preparation conditions on the pore structure of the CA was studied by nitrogen adsorption isotherms. The characteristics of the CA were studied by scanning and transition electron microscopy, and infrared spectrometry. The accessibility of pores and performance of the CA as an electrode in electric double layer capacitors were also electrochemically investigated. As a result, BET surface area and specific capacitance increased with the molar ratio of resorcinol to catalyst (R/C) ratio; the maximum values of 765 m²/g and 132 F/g were achieved at the R/C ratio of 200, respectively. Consequently, it was confirmed that increasing the R/C ratio increased the average pore size of the CA electrode, which improved the rate capability of the system.

석탄계 및 석유계 피치가 함침된 탄소/탄소 복합재료 제조 및 특성

양재연 ( Jae Yeon Yang ),박상희 ( Sang Hee Park ),박수진 ( Soo Jin Park ),서민강 ( Min Kang Seo ) 한국공업화학회 2015 공업화학 Vol.26 No.4

Unidirectional carbon/carbon (C/C) composites were manufactured using phenolic resins as a precursor of the carbonized matrix throughout a one-step manufacturing process. Also, molybdenum oxide (MoO3) and binder pitches were impregnated with phenolic resins to improve the bulk density and mechanical property of the C/C composites. In this study, the influence of MoO3 and binder pitches on mechanical properties of the C/C composites were investigated by measuring flexural strength (σf) and interlaminar shear strength (ILSS). The results show that the enhancement of interfacial adhesions between the fibers and matrix resins of the C/C composites with MoO3 and binder pitches which led to the improvement of mechanical properties of the C/C composites. This indicates that the presence of MoO3 and binder pitches in C/C composites can develop the graphite structure and increase the bulk density.

고강도 강봉을 이용한 철근 콘크리트 보의 보강에 관한 연구

양재연(Yang, Jae Yeon),박순규(Park, Soon kyu) 한국콘크리트학회 2004 한국콘크리트학회 학술대회 논문집 Vol.2004 No.5

콜타르 기반 등방성 피치 섬유의 산화안정화 공정에 대한 오존 처리 영향

양재연,고재경,윤광의,서민강,Yang, Jae-Yeon,Ko, Jae-Kyoung,Yoon, Kwang-Eui,Seo, Min-Kang 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.5

In this work, we performed ozone treatment of isotropic pitch fibers to optimize the duration and temperature during the stabilization process. The treatment worked effectively for long-term and high-temperature stabilization. The isotropic pitch fibers were ozone-treated at different ozone concentrations of 10, 20, and 30 mg/l. The surface properties of the isotropic pitch fibers were analyzed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy, while their structural characteristics were examined using X-ray diffraction. The experimental results indicated that the surface oxygen functional groups (COOH, OH, and CO) and oxygen concentration of the pitch fibers increased after the ozone treatment. During the oxidative stabilization process, the cross-linking reactions of the oxygen functional groups formed the thermosetting pitch, as confirmed by the replacement of hydrogen with oxygen. Additionally, it was observed that the ozone treatment could improve the optimized oxidative stabilization procedure in carbon fiber manufacturing. Therefore, the ozone treatment played an important role in optimizing the oxidative stabilization procedure of the pitch fibers.

가축분퇴비가 연용된 밭 토양에서 잠재적 질소 무기화량 추정

윤홍배(Hong-Bae Yun),이연(Youn Lee),유창연(Chang-Yeon Yu),양재의(Jae-E Yang),이상민(Sang-Min Lee),신재훈(Jae-Hun Shin),김석철(Suk-Chul Kim),이용복(Yong-Bok Lee) 한국토양비료학회 2010 한국토양비료학회지 Vol.43 No.3

The characteristics of nitrogen mineralization in upland soil was studied with 27-week incubation at 25℃. The used soils in this experiment were received six kinds of livestock manure compost each year for four years. Six different composts, which were chicken (CHM), pig (PIM), and cow (COM) manure composted without bulking agent, and chicken (CHMS), pig (PIMS), and cow (COMS) manure composted with sawdust as a bulking agent, were selected for this study. The first-order model was fit to the observed mineral nitrogen (N) vs incubation days using a non-linear regression procedure. The soil potential for N mineralization (No) of manure compost (CHM, PIM, and COM) treated soils were higher than those of the manure-sawdust compost (CHMS, PIMS, and COMS) treated soils. The No value of PIM applied soil was 15.0 mg 100 g<SUP>-1</SUP>, which was the highest value among the treatments. The amount of N mineralized in compost applied soils ranged from 8.1% to 11.9% of the total N content in soils and increased with increasing total N content in soils. The organic matter content in compost applied soils were negatively correlated with No value (r = - 0.69*). Therefore, our result indicated that determination of N application rate in livestock manure compost applied soil should be based on total nitrogen content better than soil organic matter content.

밭 토양에서 가축분퇴비 연용시 토양 유기물 Fraction

윤홍배(Hong-Bae Yun),이연(Youn Lee),유창연(Chang-Yeon Yu),양재의(Jae-E Yang),이용복(Yong-Bok Lee),이기상(Kee-Sang Lee) 한국토양비료학회 2007 한국토양비료학회지 Vol.40 No.5

Flupyrazofos(KH - 502) 의 토양중 용탈 및 흡착

조부연,양재의,유경렬 한국환경농학회 1997 한국환경농학회지 Vol.16 No.1

신규 활성물질인 Flupyrazofos(KH-502)의 토양에서의 흡착성, 용탈성 및 잔류성을 실내조건과 포장조건하에서 연구하여 본 공시약제의 안전사용을 위한 기초자료를 제공하고 토양-수질환경에 미칠 영향을 예측 평가하기 위한 목적으로 수행한 연구결과는 다음과 같다. 1. Flupyrazofos의 흡착량과 시간과의 사이에는 유의성있는 power function 관계가 있어서, 흡착이 빨리 일어나서 반응 30분 후에 45%가 흡착되고, 6∼12시간 이후에는 疑似평형에 도달했다. 2. Flupyrazofos의 흡착은 First-order kinetic model에 유의성있게 따랐고, 가해준 Flupyrazofos의 50%가 흡착되는 시간은 사양토의 경우 5.8시간이었다. 3. Flupyrazofos의 농도에 따른 흡착양상은 Freundlich 등온식으로 설명될 수 있었고, 등온식은 S-型으로 분류될 수 있었다. 4. 토양 column을 통해 용탈된 Flupyrazofos의 농도는 가해준 농도에 비해 매우 낮았다. 용탈된 Flupyrazofos의 농도는 사양토가 식양토보다 약간 높았다. 砂壤土에서 용탈된 최대 C/C_0 값이 0.073, 埴壤土에서는 0.017에 불과했다. 5. 표토에서 Flupyrazofos의 잔류량은 낮은편이며 시간이 경과할 수록 현저히 감소했다. 반감기는 사양토의 경우 20일, 식양토는 18일이었다. 심토로 이동·잔류된 농도는 매우 낮았다. 6. Flupyrazofos의 흡착시험, 용탈시험, 포장시험 결과와 약제의 물리화학적 특성을 근거로 판단할 때 공시농약은 토양에서 잘 흡착디고 이동·잔류성이 낮기 때문에, 상용농도를 시용할 경우 주변 환겅에 미칠 수 있는 위해성은 낮은 것으로 판단된다. Adsorption, leaching, and retention of the Flupyrazofos(KH-502), a new active ingredient for insecticide, in the soils under laborarory and field conditions were investigated to provide the basic data for the safety use and to assess a secondary impact of this insecticide on soil and water environments. A significant power function relation was found between the adsorbed KH-502 and time, representing that 45% of the added KH-502 was adsorbed within 30 min. but a quasiequilibrium was reached after 6 to 12 hr with a slower adsorption. Adsorption phenomena followed th first-order kinetics and time required for 50% adsorption was 5.8 hr. The equilibrium adsorption isotherm was explained by the Freundlich equation and was classified as S-type. The amounts of KH-502 leached through the soil column (C) as compared to initial conc. (C_0) were very low and these relative concentrations (C/C_0) were 0.073 and 0.017 in SL and CL soils, respectively. The residual conc. of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 under the field conditions were estimated to be 20 and 18 days in the SL and CL soils, respectively. The KH-502 cone, transported to the subsurface soils was extremely low. These results demonstrate that KH-502 has a low pollution risk potential to the surrounding environment as far as it is used following the recommended guideline.