• 한국환경보건학회지
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• 제29권3호
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• pp.79-85
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• 2003

The purpose of this study was to disclose the manufacturing process of activated carbon using coal. It investigated the influences on the physical properties that were manufactured activated carbon by using anthracite coal, bituminous coal under carbonizated and activated condition. The adsorption capacities of organic material were superior when the ash content was lower 5∼10%, and the iodine value was about 1,000 mg/g, the adsorption capacity decreased rapidly when ash content was over 15%. The manufactured activated carbon were found characteristics such as the iodine value was over 1,031 mg/g, the specific surface area was over 1,032 $m^2$/g and the hardness was over 95% under manufacturing conditions which were carbonizated temperature of $600^{\circ}C$( 180 minute), activated temperature of 95$0^{\circ}C$(210 minute) and steam weight of 6 $m\ell$/min.100 g coal.

• 대한화학회지
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• 제67권1호
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• pp.28-32
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• 2023

The reaction conditions optimization, including the temperature of the reaction, amount of catalyst required, and reaction time for the linoleic acids (LAs) and conjugated linoleic acids (CLAs) production by catalytic dehydration of castor oil via saponification was investigated by response surface methodology (RSM). It was confirmed that all three parameters (temperature, time, and amount of catalyst) were influential factors in isolating LAs and CLAs. When the temperature was increased, the iodine value increased, and the reaction time and catalyst amount increased. The optimal reaction conditions were: 240 ℃, 2.2 h reaction time, and 7 wt% catalyst amount. The maximum iodine value reached 156.25 with 91.69% conversion to the essential fatty acids.

• 임산에너지
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• 제22권1호
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• pp.17-23
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• 2003

3, 5, 7년생의 중국산 죽순대(Phyllostachys pubescense)를 탄화온도가 서로 다른 3 종류의 탄화로(전용, 개량 및 간이 탄화로)에서 제탄하고 얻어진 대나무 숯의 이화학적 특성을 검토하였다. 전용 탄화로(800 - 1,000℃)에서 제조한 대나무 숯의 고정탄소는 죽령이 증가함에 따라 감소하는 경향을 나타내었으나 비표면적의 경우 죽령에 따라 증가하였다. 요오드 흡착량은 5년생이 가장 높았다. 개량 탄화로(600 - 700℃)로 제탄한 경우 비표면적과 요오드 흡착량은 전반적으로 생육기간이 길어짐에 따라 증가하는 경향을 나타내었다. 간이 탄화로(400 - 500℃)에서 제조한 죽탄의 경우 휘발분이 개량 및 전용 탄화로보다 약 2배나 높음에도 불구하고 고정탄소는 80%이상의 높은 간을 나타내었다. 본 탄화로에서 5년생의 죽순대를 제탄하여 얻어진 대나무 숯의 경우 타 죽령에 비하여 가장 높은 비표면적과 요오드 흡착량을 나타내었다. 한편 3, 5년생의 중국산 죽순대로 제조한 대나무 숯은 동일 죽령의 국산 죽순대로부터 제조한 대나무 숯보다 물리적 성질이 비교적 좋지 않았다. 이것은 중국산 3, 5년생의 죽순대의 조직구조가 동일죽령의 국산보다 치밀하지 못한 것에 기인하는 것으로 생각되었다.

• Preventive Nutrition and Food Science
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• 제2권3호
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• pp.202-206
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• 1997

To develop mil fat fractions with desirable physico-chemical properties, anhydrous milk fat (AMF) was fractionated by one- and two-stage extractions using supercritical $CO_2$(SC-$CO_2$). Tow-stage extraction of AMF was performed by first producing tow fractions, an extract and a residue at 4$0^{\circ}C$/241bar, which were subsequently used as the feed for an extraction at 6$0^{\circ}C$/241bar and 4$0^{\circ}C$/345bar, and separated into five and four fractions, respectively, based one extraction time. These fractions were quantified and analyzed for fatty acids and physico-chemical properties. SHort-chain (C4~C8) fatty acids in extract fractions from an extract were 200~150% compared with those of the original AF. Long-chain (C14~C18) fatty acids in extract fractions from a residue were 118~141%. The ratio of unsaturated fatty acids in the residue fraction was 131%. Melting point ranged from 22 to 43$^{\circ}C$, iodine value 21.8 to 36.9, and saponification value 255 to 221 in the extract and residue fractions. SC-$CO_2$ fractionation of AMF by two-stage extraction offers the possibility of developing ractions with discrete fatty acid compositions and physico-chemical properties such as melting point, iodine value and saponification value.

• 한국식품조리과학회지
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• 제12권3호
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• pp.367-371
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• 1996

실험실에서 제조한 동백유의 몇가지 이화학적 특성은 요오드가가 78.2로 나타나 불건성유로 분류되었고, 지방산 조성은 Oleic acid가 총 지방산함량 중 84.7%를 차지하여 Mono unsaturated fatty acid의 함량이 매우 높은 기름으로 측정되었다. 40$\pm$5$^{\circ}C$의 항온저장시 산화안정성은 동백유가 대두유에 비해 과산화물가와 산가 측정에서 모두 저장 안정성이 높은 것으로 비교되었다. 180$\pm$5$^{\circ}C$에서 튀김시의 동백유 시료의 산가는 튀긴 횟수의 증가에 따라 대두유 시료와 별 차이 없이 모두 점진적으로 증가하였으나 요오드가의 변화는 동백유 시료에 비해 대두유 시료가 2배 이상 감소된 것으로 나타났다. 동백유, 대두유, 옥배유로 튀긴 Potato chips의 관능평가는 맛, 색, 냄새 등의 종합적인 기호도 측정에서 시료간의 유의적인 차이가 5% 수준에서 인정되었으며, 동백유의 튀김시료가 가장 선호도가 높은 것으로 나타났다.

• 한국방사선학회논문지
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• 제17권1호
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• pp.1-9
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• 2023

전산화단층촬영조영술(computer tomography angiography, CTA)의 최적 화질을 위한 서로 다른 요오드 농도와 스캔 매개변수를 적용하여 필터 보정 역투영 (filtered back projection, FBP), 혼합형 반복재구성 (hybrid-iterative reconstruction, hybrid-IR) 및 딥러닝 재구성 (deep learning reconstruction, DLR)의 화질적 특성을 정량적으로 평가하였다. 320행 검출기 CT 스캐너에서 지름 19 cm의 원통형 물 팬텀 가장자리에 있는 다양한 요오드 농도 (1.2, 2.9, 4.9, 6.9, 10.4, 14.3, 18.4 및 25.9 mg/mL)의 팬텀을 스캔하였다. 각각의 재구성 기술을 사용하여 획득한 데이터는 노이즈 (noise), 변동 계수 (coefficient of variation, COV) 및 평균 제곱근 오차 (root mean square error, RMSE)을 통해 영상을 분석하였다. 요오드의 농도가 증가할수록 CT number 값은 증가하였지만 노이즈 변화는 특별한 특성을 보이지 않았다. 다양한 관전류 및 관전압에서 FBP, adaptive iterative dose reduction (AIDR) 3D 및 advanced intelligent clear-IQ engine (AiCE)에 대해 요오드 농도를 증가할수록 COV는 감소하였고 요오드 농도가 낮을 때는 재구성 기술 간의 COV 차이가 다소 발생하였지만, 요오드 농도가 높아짐에 따라 그 차이는 미약한 결과를 보였다. 또한, AiCE에서는 요오드 농도가 높아질수록 RMSE는 감소하지만 특정한 농도 (4.9 mg/mL) 이후에는 RMSE가 오히려 증가 되는 특성을 보여주었다. 따라서 최적의 CTA 영상 획득을 위해 재구성 기술에 따른 요오드 농도의 변화 및 다양한 관전류 및 관전압의 스캔 매개변수의 특성을 고려하여 환자 스캔을 해야 할 것이다.

• 한국식품영양학회지
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• 제35권1호
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• pp.62-73
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• 2022

Omija seed oil was extracted from Omija seeds, a by-product of Omija, using an eco-friendly pressed extraction method. Physicochemical properties and antioxidant activities of 12 extracts using different combinations of seed moisture content (5, 7.5, and 10%) and extraction temperature (25, 49, 75, and 100℃) were then investigated. The highest extraction yield was 31.33% at moisture of 5% and temperature of 75℃. The lowest acid value was 4.18±0.25 at moisture of 5% and temperature of 49℃or moisture of 7.5% and temperature of 25℃. Peroxide value, iodine value, and saponification value were the lowest at 0.64±0.56 meq/kg, 159.38± 6.03, and 57.60±9.40, respectively, at moisture of 5% and temperature of 25℃. The content of total polyphenolics was the highest at 4,413±125 mg TAE/100 g when the moisture content was 10% and the extraction temperature was 25℃. DPPH radical scavenging activities of oil extracts at 20~100 mg/mL were 28.68±7.30~87.65±2.20%. The maximum antioxidant activity and IC₅₀ were 87.65±2.20% and <20 mg/mL, respectively, for extract obtained at moisture of 10% and temperature at 100℃. As a result, the extraction yield, acid value, peroxide value, iodine value, saponification value, and so on were excellent at moisture content of 5% and extraction temperature of 25℃ or 49℃. However, the content of total polyphenolic compounds and antioxidant activity were the highest at moisture of 10% and extraction temperature of 100℃. In conclusion, extracting Omija seed oil from Omija seeds, a by-product of Omija, is effective with a pressed extraction method.

• 한국식품영양과학회지
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• 제23권4호
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• pp.654-659
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• 1994

대두유와 면실유를 $160^{\circ}C,\;180^{\circ}C,\;200^{\circ}C\;및\;220^{\circ}C$에서 60시간 연속 가열하면서 이 때 일어나는 물리화학적 특성변화를 살펴보고 이들 간의 상관관계를 조사하였다. 가열시간이 경과함에 따라 산가, 카르보닐가, 요오드가, 점도, 중합체 함량은 증가하였고, 요오드가는 감소하였으며, 가열온도 $180^{\circ}C$ 이하에서는 이들의 변화가 낮았고, $200^{\circ}C$ 이상에서는 전체적으로 높게 나타났다. 점도와 산가 변화의 상관도는 대두유 0.9843, 면실유 0.9819이었고, 점도와 카르보닐가의 변화에서는 대두유 0.9779, 면실유 0.9797이었다. 점도와 요오드가의 변화에서는 대두유 0.9852, 면실유 0.9948로 나타났다. 이상의 결과는 튀김유의 가열산화에 있어서 점도의 변화를 측정함으로써 산가, 카르보닐가 및 요오드가의 변화를 비교적 정확하고 빠르게 예측할 수 있음을 시사하고 있다고 사료된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.87-90
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• 2006

The experimental study has been done for two kinds of pelletized RDFs to Investigate the carbonization effect to the chlorine concentrations, the heating value and the yield of Produced char in variable conditions of the carbonizing temperature and reaction time. One(RDF-1) is made of 100% wasted plastics and the other(RDF-2) is made of 60% wasted paper with 40% wasted plastics. The screw type carbonizer heated Indirectly by oil burner was used for the experiment and RDF feeding rate was 3kg/hr. The carbonizing temperature was 300, 350 400 and $45^{\circ}C$ and the reaction tine was 5, 10 and 15 minutes respectively. As the increase of carbonizing reaction time and temperature, the chlorine reduction rate was increased and oppositely the yield of char was decreased At the temperature of $400^{\circ}C$ and reaction time of 10 minutes the chlorine reduction rate was 60% and the char yield rate was 80% for the RDF-1 and those of RDF-2 were 80% and 75%, respectively. Additional activation experiment to the char produced from RDF-2 was done in the activation reactor by hot steam supply. As the increase of activation time the iodine number was increased. At the activation time of 20 minutes the iodine number was 552mg/g and the yield of activated carbon was 16%.

• 한국세라믹학회지
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• 제46권6호
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• pp.568-573
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• 2009

In this study, we used coal based activated carbons as starting material and phenolic resin (PR) as a bonding agent to prepare spherical shaped activated carbons. The textural properties of SAC were characterized by BET surface area, XRD, SEM, iodine adsorption, strength intensity and pressure drop. According to the results, the spherical activated carbon prepared with activated carbon and PR at a ratio of 60:40 was found to have the best formation of spherical shape, which was found in sample SAC40. After activation, SAC40 has high BET surface area, iodine adsorption capability and strength value, and lowest pressure drop.