• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.513-516
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• 2011

본 연구에서 NaOH, Acetic acid, Silane 처리는 천연섬유와 matrix간의 계면 결합에 불리하게 작용하는 wax, lignin, hemicellose 등을 제거하기 위한 방법 중의 하나이다. 이러한 화학적 처리에 따른 왕겨분말의 형태학적 변화와 열적특성 변화를 관찰하였다. 전처리 조건으로 농도는 1.5%, 3%, 9%이며 각각 30min, 60min, 90min을 처리하였다. 처리하지 않은 왕겨 분말과 NaOH, Acetic acid, Silane 처리를 한 왕겨 분말의 성분을 Energy dispersive spectroscopy(EDS)로 분석하였으며, Scaning electron microscopy(SEM)으로 표면을 관찰하였다. 표면의 상태가 NaOH, Acetic acid, Silane 처리를 하였던 왕겨 분말이 처리를 하지 않았던 왕겨 분말보다 비교적 깨끗해지고, 크랙이 발생함을 확인하였다. 또한 전처리가 된 상태에서 수분흡수율을 측정하고, 처리를 하지 않은 왕겨 분말과 NaOH, Acetic acid, Silane 처리를 한 왕겨 분말을 Thermogravimetric Analysis(TGA)로 열분석을 실시하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.307-310
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• 2010

The research for production of jet fuel from petroleum displacement resources such as bio-mass, coal, natural gas mainly consists of three sub-research areas; the fisrt step is the pretreatment for producing a synthetic gas, and the next step is the Fischer-Trophsh reaction process for making hydrocarbons. The last is the upgrading technology for the hydrocarbons to fit a jet fuel specification via cracking and isomerization reactions. This talk presents reaserch trends and main technologies for production of jet fuel derived from petroleum displacement resources.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.48-55
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• 1998

An acute ethanol load(50mmol/kg , i.p) resulted in an increase in peroxidation and a decrease in the levels of $\alpha$-tocopherol and ascorbate in rat cerebellum. Pretreatement with allopurinol(146$\mu$mol/kg, i.p) prevented the ethnol-induced increment in lipid peroxidation and decrease in $\alpha$-tocopherol content. However, the decrease of ascorbate was of greater magnitude when allopurinol was associated with ethanol. These results suggested that allopurinol. besides its action as a radical scavenger and xanthine oxidase inhibitor, might favor the regeneration of $\alpha$-tocopherol antioxidant acitviity was studied using ${\gamma}$-radiolysis in aerated ethanolic solutions. Even though allopurinol did not react by itself with $\alpha$-hydroxyethyl-peroxyl radicals [H3C-CH(OH)OO] , it enhance the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$tocopherol. The regeneration of $\alpha$-tocopherol from the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$-tocophero. The regeneration of $\alpha$-tocopherol from the $\alpha$-tocopherol radical by ascorbate remained as efficient in the presence of allopurinol as in its absence. The effects of allopurinol on the Vitamin E oxidation-reduction mechanism could be involoved in the beneficial effectof allopurinol on the biological cellular damages linked to free radical reactions.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.171-171
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• 2011

리그노셀룰로오스 바이오매스를 원료로 하여 발효당을 생산하고자 할 때 최종적인 당수율은 적용하는 전처리 기술의 종류와 전처리 조건에 따라 크게 달라질 수 있다는 사실은 널리 알려져 있다. 또한 전처리물의 효소당화에서 셀룰로오스의 당전환율은 효소의 종류와 사용량에 의존적이므로 부족한 전처리 효과를 일부 보완하기도 한다. 본 연구에서는 바이오매스의 효소당화에 흔히 사용되고 있는 특정효소와 최근 공급되기 시작한 새로운 효소를 시료로 하여 해바라기 줄기의 열수전처리에 이은 효소당화에서 효소의 종류가 최종 당수율, 효소당화 시간 및 전처리효과에 미치는 영향을 측정하였다. 해바라기 줄기 분말을 $180^{\circ}C$에서 30분 동안 열수전처리하였을 때 헤미셀룰로오스의 수율이 최대가 되었으나 이 조건에서는 후속 효소당화에 의한 포도당 수율이 높지 않았다. Celluclast 1.5L 혹은 Celluclast conc BG는 전처리 물의 당화속도가 상대적으로 빠른 편이었고, 이 효소에 의한 당수율은 해바라기 줄기 셀룰로오스 함량의 80% 내외였으며, 바이오매스 1g당 효소첨가량이 3ml까지 증가함에 따라 당수율도 꾸준히 증가하는 경향을 보였다. 반면에 노보자임 스코리아로부터 분양받은 효소로서 NS22074와 NS50010의 혼합물은 Celluclast보다 약 10% 더 높은 당수율을 보여주었으나 당화는 상대적으로 느리게 진행되어 72시간 이상이 소요되었다. Endoxylanase 혹은 hemicellulase 등 다른 효소를 NS22074와 NS50010의 혼합물에 가하여도 당수율의 증대 효과는 미미하거나 거의 없었다. 시험에 사용한 효소제제에는 포도당, 소르비톨 등 여러 가지 당들이 보존제 혹은 안정화제로 함유되어 있는 것으로 나타나서 사용에 주의할 필요가 이었다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.1
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• pp.96-102
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• 1994

Factors affecting non-proficient analytical ability were compared and evaluated by rating of laboratories and round. Analyst Indices between proficient and non-proficient participants were different. Coefficients of determination($R^2$) for standard of toluene, xylene and trichloroethylene of the 4th round between some proficient and non-proficient participants were significantly different(p<0.05). But, there was no difference in the 5th round. Average desorption efficiency of non-proficient participants was 88%-98%, which was lower than 96%-100% of some randomly selected proficient participants. Also non-proficient participants have a large variance of desorption efficiency, 11.79-19.69%. In the 5th round, desorption efficiency of metyl iso-butyl ketone(MIBK) reported by all participants was lower than 90% tested by NIOSH and especially low compared to other analytes. Participants evaluated to be non-proficient in the metal part have 85%-100.84% of average recovery, which was larger variance than 98% of some proficient participants. Although it is difficult to find quantitatively factors causing non-proficiency in analytical ability, pretreatement techniques and experience of analyst seems to be more important factors to produce accurate analytical result.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.95-118
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• 1987

This study was undertaken to observe the elemental transition of Interface depending on different pretreatment methods, the number of filings, the kinds of porcelain powders and the various alloys in ceramo-metal restoration. The materials used in this study were Pors-on $4^{(R)}$ and Ceramco porcelain powder to compare the differences depending on the pretreatement methods and the number of firings. Ceramco porcelain powder and Vita porcelain powder were used to compare the differences of elemental transition depending on the porcelain powders. The $Parasil^{(R)},\;PGV^{(R)}$ and Pors-on $4^{(R)}$ as Pd-Ag alloy were used to compare the difference of elemental transition depending on the various alloys. The pretreatment methods were : no treatment, treatment under vacuum and air, treatment with 50 % hydrofluoric acid and double heat tretament. The number of firings were 3, 5 and 7 repeated firings All specimens were observed by SEM and concentration of elements were analyzed quantitatively with EPMA The results of this study were obtained as follows : 1. In the groups of air-treatment, concentration of Sn were the highest and widest. A high concentration of In were in the groups of vacuum and air treatment. 2. There were no significant differences in concentration of Sn between the group of vacuum, 5 minutes hydrofluoric acid and double heat treatment. (p>0.05) 3. As the period of time of hydrofluoric acid treatment increased, not only were the trace elements reduced but the main components such as Pd and Ag were also reduced. 4. Concentration of Sn and In increased and diffused with repeated firings but 5 repeated and 7 repeated firings groups had no significant differences. (p>0.05) 5. Sn were more concentrated in the group of Ceramco porcelaion powder than Vita porcelain powder. 6. The higher concentration of trace elements in the alloy, the more increasing concentration of Sn and In in the interface.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.3
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• pp.110-116
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• 2016

Biogas yields point of view, the possibility of reusing excess sludge treated by thermal pretreatment for the purpose of improving the efficiency of the anaerobic digestion process has been investigated in recent year. Thermal pretreatment technology was considered as a pretreatment technique to improve excess sludge properties because of the solubilization of particulate organics. As a view point of sludge reduction and recycle, however, many researchers focused on the ability of particulate hydrolysis and COD solubilization under a high temperature, and few reports have addressed on the physical/chemical characteristics changing. This research was performed to evaluate the effects of a various temperature and chemical additives on carbon formation and fractionation in treated slurry from thermal pretreatment. Based on the results, it was revealed that oxidants injection and temperature changing have significantly caused the change of carbon fractions in slurry from thermal pretreament. Especially, it was considered that the efficiencies of particle hydrolysis increased with the increase of the reaction temperature. Low molecular weight(Mw < 350 g/mol) organic carbon formation increased with the increase of oxidants injection. It was expected that results of this research will provide an overview of the characteristics of thermal pretreatement for excess sludge reduction and recycle.