• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.329-329
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• 2007

• 한국환경보건학회지
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• 제33권5호
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• pp.456-461
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• 2007

This study was carried out two point view that reuse of sludge and adsorption of benzene, toluene and o-xylene of VOCs in cast, carbonized cast and activated carbon. The cation exchange capacity of cast and carbonized cast were 59.2, 112 meq/100g, respectively. The specific surface were 560, $800m^2/g$, respectively. The average removal rates of benzene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 15.0, 41.2, 88.2, 99.4% in 60min of retention time. The average removal efficiency of toluene by 50 g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 12.5, 34.2, 88.2, 99.5% in 60 min of retention time. The average removal rates of o-xylene 50 g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 8.8, 28.5, 84.8, 98.1% in 60min of retention time. The adsorption efficiency of test absorbent was in order of Activated Carbon > Carbonized Cast > Cast.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.125-128
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• 2005

폴리스티렌의 열분해반응에서 분해반응속도 및 생성되는 오일 중에 함유된 스틸렌모노머와 부산물로 얻어지는 에틸벤젠, 알파메틸스티렌, 다이머, 트라이머 등은 반응온도 및 반응시간 등의 여러 가지 변수들에 의해 영향을 받았으며, 특히 반응시간에 따라 반응성 및 스티렌의 수율은 많은 차이를 보였다. 이 결과는 열분해 반응과정에서 생성되는 유기성 잔류물과 고화탄소의 영향 때문에 기인하였다. 연속열분해시간의 진행과 함께 생성되는 오일의 수율이 저하되었으며 오일에 함유되어 있는 스티렌의 선택도는 감소하였으며 부산물인 알파메틸스티렌, 에틸벤젠, 벤젠, 톨루엔 등의 부산물의 생성은 증가하였다. 본 연구결과로부터 새로운 연속반응을 위한 열분해반응기를 사용하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1989년도 추계학술발표회논문집
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• pp.65-70
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• 1989

This paper presents resarch results on the use of a corona detector and a pulse counter in order to diagnose for oil transformers. Using these experimental apparatus, tests were carried out on a typical transformer oil containing different carbonized paper and various moisture contents to measure the picocoulomb val-ues and pulse count. Through the result of this study it was found that the picocoulomb values and pulse count of corona were depended on the getting stained in transformer oil. The amplitude of the partial discharge amount and the number of pulse were decreased up to 70 [。c] and then was increased as the oil temperature goes up. It was concluded that the determinati-on level for diagnosis of oil transform-er was taken into account the temperatu-er of transformer oil, The use of pulse counter method, which have been taken the same property of voltage and temperature variation for the corona measurement mothod, considera-bly increase insulator avilability.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.29-30
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• 2023

Wood is a construction material that has the advantages of carbon dioxide storage ability, noise reflection, and eco-friendliness. In order to use wood for a long time, you must use wood-specific paint, which is called oil stain. Oil stain improves water resistance and moisture resistance, but has the disadvantage of being weak against fire. This is because the oil contained in the oil stain causes a chemical reaction, and this chemical reaction causes the oil stain to spontaneously ignite, igniting nearby combustible materials and causing frequent fires. To improve this, in this study, different flame retardants were mixed and added to oil stain to produce functional oil stain. In addition, we would like to apply it to wood to check glow time and carbonization area. As a result of the experiment, it shows the best performance when mixed at 30(15 + 15)(%) and added to oil stain. The remaining burn time is satisfied from 10% for all samples, and the carbonized area is satisfied when it is 30%.

• Fibers and Polymers
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• 제2권4호
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• pp.178-183
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• 2001

A pitch precursor for a general purpose carbon fiber was prepared by condensation of pyrolized fuel oil (petroleum residual oil) with bromine under nitrogen blowing. such a condensation raised the softening point of the pitch from 4$0^{\circ}C$ to $265^{\circ}$ with a yield of 43%. The pitch precurosr showed an enhanced aromaticity and enlarged molecular size, which led to a reduction in molecular mobility and optical isotropy. The precursor was spun into fibers of $20\mu\textrm{m}$ diameter at a take-up speed of 700m/min. The fiber was stepwise stabilized in air and carbonized in Ar gas to obtain an isotropic carbon fiber. The carbon fiber exhibited tensile strengths of 500-800 ㎫though the fiber was formed via a crude method. The electric conductivity of the carbon fiber was relatively high, 2.2$\times$$10^2$S/cm, sufficient to be used as electrode materials.

• Fibers and Polymers
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• 제1권2호
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• pp.97-102
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• 2000

Pitch precursors were synthesized from coal tar(CT) and pyrolysis fuel oil(PFO, petroleum residue oil) at relatively low temperature of $250^{\circ}$, in the presence of horontrifluorideidiethyletherate complex(BFDE) as a catalyst and nitrobenzene(NB) as a co-catalyst. The softening point, nitrogen content and carbon yield increased with an increase of concentration of NB. The pitch precursors with good spinnability were prepared by removing the volatile components through $N_2$ blowing. The precursor pitches were spun through a circular nozzle, stabilized at $310^{\circ}$ and finally carbonized at $1000^{\circ}$. The optically anisotropic structure formed at the absence of NB was changed into isotropic structure, showing a decrease in size of the flow domain. The hollow carbon fiber could be prepared in the process of stabilization. The results proposed that the morphology of carbon materials could be controlled by changing the concentration of catalyst and/or co-catalyst and/or stabilization condition that affect on the mobility of molecules during carbonization.

• 공업화학
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• 제33권5호
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• pp.496-501
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• 2022

본 연구에서는 석유 정제 부산물인 석유계 잔사유를 이용하여 리튬이차전지용 음극재를 제조하였다. 석유계 잔사유 중 열분해 연료유(pyrolysis fuel oil, PFO), 유동접촉분해 데칸트 오일(fluidized catalyst cracking-decant oil, FCC-DO), 감압잔사유(vacuum residue, VR)를 탄소 전구체로 사용하였다. MALDI-TOF, 원소분석(EA)을 통하여 석유계 잔사유의 물리화학적 특징을 확인하였고, 잔사유로부터 제조된 음극재는 XRD, Raman 등의 분석을 통해 그 구조적 특징을 평가하였다. VR은 PFO 및 FCC-DO에 비하여 광범위한 분자량 분포와 많은 양의 불순물을 함유하는 것을 확인할 수 있었고, PFO와 FCC-DO는 거의 유사한 물리화학적 특징을 나타내었다. XRD 분석결과로부터 탄화된 PFO와 FCC-DO는 유사한 d₀₀₂값을 나타내었다. 그러나 Lc 및 La값에서는 FCC-DO가 PFO보다 더 발달된 층상구조를 갖는 것으로 확인되었다. 또한, 전기화학적 특성 평가에서는 FCC-DO가 가장 우수한 사이클 특성을 나타내었다. 이러한 석유계 잔사유의 물리화학적, 전기화학적 결과로 미루어 보아 FCC-DO가 PFO와 VR보다 더 우수한 리튬이차전지용 탄소 전구체인 것으로 사료된다.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권6호
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• pp.297-303
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• 2002

We have developed an on-line ultrasonic detector to monitor partial discharge in an operating transformer. The ultrasonic sensor has 150[KHz] resonance frequency and contains a pre-amplifier with 60[㏈] gain. The on-line ultrasonic detector has 50~300[KHz] frequency band-pass filter to remove electrical and mechanical noises from the transformer. This detector has an ultrasonic signal discrimination algorithm which discriminates ultrasonic signals due to partial discharge in a transformer. A moving average method of ultrasonic signal number was employed to effectively monitor the increasing trend of the partial discharge. This paper describes an experience of partial discharge detection in a 154[㎸] operating transformer using an ultrasonic detector. With regards to gas analysis in oil, C2H2 gas was produced with a warning level in this transformer We detected ultrasonic signals on the transformer steel wall, and estimated the position of partial discharge. With further inspection, we found carbonized marks due to partial discharge on the supporting bolt which fastens the windings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1393-1395
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• 1997

In order to investigate the interfacial effects on the aging of power cables, we analyzed recently failed cables using characterization techniques. In this study, some cables showed a convolution which can cause the concentration of electric field and carbonized impurities at the surface of insulation. Also there is a relation between the degree of cross- linking and volume resistivity. From the hot oil test, the sites of water tree and void coincided with each other.