• Advances in Energy Research
• /
• 제4권1호
• /
• pp.69-86
• /
• 2016

The quest to reduce the level of overdependence on fossil fuel product and to provide all required information on proven existing alternatives for renewable energy has resulted into rapid growth of research globally to identify efficient alternative renewable energy sources and the process technologies that are sustainable and environmentally friendly. The present study is aimed at production and characterization of bioethanol produced from sugarcane juice using a $2^4$ factorial design investigating the effect of four parameters (reaction temperature, time, concentration of bacteria used and amount of substrate). The optimum bioethanol yield of 19.3% was achieved at a reaction temperature of $30^{\circ}C$, time of 72 hours, yeast concentration of 2 g and 300 g concentration of substrate (sugarcane juice). The result of statistical analysis of variance shows that the concentration of yeast had the highest effect of 7.325 and % contribution of 82.72% while the substrate concentration had the lowest effect and % contribution of -0.25 and 0.096% respectively. The bioethanol produced was then characterized for some fuel properties such as flash point, specific gravity, cloud point, pour point, sulphur content, acidity, density and kinematic viscosity. The results of bioethanol characterization conform to American society for testing and materials (ASTM) standard. Hence, sugarcane juice is a good and sustainable feedstock for bioethanol production in Nigeria owing relative abundance, cheap source of supply and available land for large scale production.

• Korean Chemical Engineering Research
• /
• 제49권3호
• /
• pp.325-329
• /
• 2011

본 연구를 통해 최근 개발된 근자외선영역대에서 발광하는 이리듐 착물인 $Ir(pmb)_{3}$ (Iridium(III) Tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,$C,C^{2'}$ ))의 합성 과정상에서 기존의 합성법과 동일한 발광 특성을 가지면서 더 효율적인 합성 방법을 제안하였다. 합성 과정에서 초음파가 투입되면서 용매에 녹지 않는 반응물의 파쇄 및 혼합을 돕고, 촉매의 활성을 향상시켜 이온 및 라디컬을 형성시키는 방법으로 최대 42.5% 합성 수율을 얻어 내었으며 이는 기존 방법 대비 약 4배 이상 향상된 결과이다. 이러한 초음파 합성법으로 합성된 $Ir(pmb)_{3}$은 이성질체 별로 405 nm(면이성질체) 412 nm(자오선이성질체)의 발광 피크를 보였으며 이중 좀더 효율이 높은 자오선이성질체를 사용하여 전계 발광 소자를 제작하였다. 밴드갭이 큰 $Ir(pmb)_{3}$에 적합한 호스트 물질을 UGH2, CBP, mCP 세가지 선정하여 전계발광소자를 제작하였으며, 그 중 mCP를 호스트 물질로 사용한 소자의 경우가 호스트물질과 인광물질사이의 에너지전달이 가장 효율적으로 일어나 가장 높은 휘도와 효율을 보였다.

• The Korean Journal of Ceramics
• /
• 제4권4호
• /
• pp.345-351
• /
• 1998

Thermal shock resistance of $Al_2O_3$- and Fe-$Al_2TiO_5$-based Castable Refractories was studied using a central heating technique. Ring type specimens, 10mm thick and 20 and 100mm inner and outer diameters, respectively, were rapidly heated on the internal surface of the centre hole using a high power electrical heating element. The temperature field was measured experimentally and modelled using finite element analysis (FEA). The thermal stress field was also modelled using FEA. A radial notch was introduced to the ring specimens to enable calculation of the thermal stress intensity factors (SIF). A special LVDT device was incorporated in the thermal shock tester to monitor crack mouth opening displacement (COD). The thermal shock fracture initiation and crack propagation behaviour of the castable refractories were ascertained using the COD measurements and the fracture mechanics analysis data.

• 국제학술발표논문집
• /
• The 1th International Conference on Construction Engineering and Project Management
• /
• pp.533-538
• /
• 2005

An outline of an Artificial Neural Network (ANN) model for bridge condition rating and the results of a pilot study are presented in this paper. Most BMS implementation systems involve an extensive range of data collection to operate accurately. It takes many years to effectively implement a BMS using existing methodologies. This is due to unmatched data requirements. Such problems can be overcome by adopting the ANN model presented in this paper. The objective of the proposed model is to predict bridge condition ratings using historical bridge inspection data for effective BMS operation.

• 대한약리학회지
• /
• 제31권2호
• /
• pp.145-152
• /
• 1995

The effects and interactions of $4{\beta}-phorbol$ 12,13-dibutyrate(PDB) and polymyxin B(PMB) with adenosine on the electrically-evoked norepinephrine (NE) release were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $^3H-noradrenaline$ and the release of the labelled product, $^3H-NE$, which evoked by electrical stimulation$(3\;Hz,\;2\;ms,\;5\;VCm^{-1},\;rectangular\;pulses)$ was measured. PDB$(0.3{\sim}10\;{\mu}M)$, a selective protein kinase C(PKC) activator, increased the evoked NE release in a dose related fashion while increasing the basal rate of release. And the effects of $1\;{\mu}M$ PDB were significantly inhibited by $0.3\;{\mu}M$ tetrodotoxin(TTX) pretreatment or $Ca^{++}-free$ medium. $PMB(0.03{\sim}1\;mg)$, a specific PKC inhibitor, decreased the NE release in a dose dependent manner while increasing the basal rate of release. Adenosine $(1{\sim}10\;{\mu}M)$ decreased the NE release without changing the basal rate of release, and this effect was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine$(2\;{\mu}M)$, a selective $A_1-receptor$ antagonist, treatment. Also, adenosine effects were significantly inhibited by PDB-and PMB-pretreatment. These results suggest that the PKC plays a role in the NE release in the rat hippocampus and might be participated in a post-receptor mechanism of the $A_1-adenosine$ receptor.

• 산업경영시스템학회지
• /
• 제44권3호
• /
• pp.39-49
• /
• 2021

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force's de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

• 대한영상의학회지
• /
• 제84권3호
• /
• pp.763-769
• /
• 2023

유방 실질의 원발성 악성 흑색종은 극히 드물며, 대부분 유방 내 만져지는 종괴로 나타난다. 유방 농양으로 나타난 원발성 악성 흑색종은 아직까지 영문 문헌에 보고된 바 없다. 저자들은 반복적으로 재발하는 유방 농양이 있었던 71세 여자 환자에서 진단된 유방 실질의 원발성 악성 흑색종을 보고하고자 한다. 유방 자기공명영상 검사에서 조영증강되는 고형 부분과 낭성 또는 괴사 부분을 동반한 종괴가 있었고, 조영 전 T1 강조 영상에서 높은 신호 강도인 부분과 T2 강조 영상에서 어두운 신호 강도인 테두리가 있었다. 재발성 유방 농양의 임상 소견을 보인 본 증례에서 기저의 악성 질환 가능성을 의심하고 정확한 진단을 얻는 데 MRI 소견이 결정적인 역할을 하였다.

• 한국식품영양학회지
• /
• 제29권5호
• /
• pp.760-766
• /
• 2016

To increase the collagen recovery rate, bromelain (PB) and a microbial enzyme (PM) were used to treat to pork skin with single agent or combinations. The quality of collagen from the pork skin was evaluated by enzymatic treatments. The highest results for the solid contents and pork skin recovery rate obtained with the microbial-enzyme-bromelain mixtue (PMB) were 13.60% and 18.05% respectively. The result also showed that the color was affected by different types of enzyme treatments. Although PM treatment showed the highest result in the protein content of 251.30 mg/100 g, PMB treatment was the highest in the test of collagen content of 37.73 g/100 g among the treatments. However bands of the pork skin were detected widely at 130 kDa and 170 kDa ranges in SDS-PAGE. The band of PB treatment showed at the range of below 17 kDa, changed into a smaller molecular weight. The collagen content test of the pork skin by the treatments, collagen contents with combination treatment of pork skin with PMB (0.5%) resulted the highest in 43.76 g/100 g. Also the fat content at the above treatment was reduced to 11.12% compared to the other treatments. With these results of this experiment, we conclude that the enzymatic treatments were effective for the processing property of pork skin like enhancing the yield of collagen.

• 보존과학회지
• /
• 제27권4호
• /
• pp.395-401
• /
• 2011

석조 문화재의 보존을 위한 효과적인 처리 방법으로 제안되는 가압 함침 방법으로 methyl methacrylate (MMA), MMA-butyl acrylate (PMB73) 공조성물 및 MMA-vinyl trimethoxy silane (PMV5) 공조성물을 사용하여 사암 및 화강암에 함침 처리한 후 물리 화학적 특성을 평가하였다. 화강암과 비교하여 사암의 경우 함침율이 3.2 - 3.7 wt%로 높은 값을 보였고 고압 반응기 내에 감압 공정 도입 시 32%의 함침율 증가를 나타내었다. 물리화학적 특성인 발수성, 휨강도, 충격특성 및 초음파 속도 등도 화강암보다 사암에 대해 아크릴계 가압함침 처리제의 효과가 두드러지게 나타남을 알 수 있었고, 이는 사암의 공극이 많아 단량체 함침율이 크기 때문으로 해석할 수 있었다. 아크릴계 처리제별 사암에 대한 충격파괴 에너지는 PMMA의 경우 1.22 J, PMB73은 1.84 J, 그리고 PMV5의 경우 2.8 J을 나타내었다. 충격 특성에서 무기 특성을 개선한 PMV5가 최적의 성질을 나타내는 것은 아크릴계 처리제의 분자 구조보다는 처리제의 무기 친화 특성이 석재의 충격 특성에 더 많은 영향을 주기 때문으로 해석할 수 있었다.

• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
• /
• pp.98-98
• /
• 2005