• Korean journal of food and cookery science
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• v.21 no.4 s.88
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• pp.440-446
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• 2005

To determine the shelf-life of low salted Myungran-jeot (low salted and fermented Alaska pollack roe), various chemical, microbiological and sensory analyses were carried out with Myungran-jeot stored at 10 days. The lactic acid content was slowly increased in the early stage of storage but then was rapidly increased with lengthening storage period, while pH was decreased during storage. The $NH_2-N$ content was steady at 10 days and peaked at 17 days. The production of VBN was increased to over $30mg\%$ at 19 days. In microbiological tests, the viable cell count and halotolerant bacteria were $1.5\times10^3\;and\;5.5\times10^3CFU/g$, respectively, at the initial state, but they slowly increased to $10^7 CFU/g$ at 17 days. Yeast or fungi did not appear on the surface of Myungran-jeot. Sensory evaluation showed that the original torture of Myungran-jeot in the mouth was a very important indicator for acceptability. Sensory characters and acceptability of Myungran-jeot at 17 days were not significantly different from those of the initial state. From these results, the estimated shelf-life of Myungran-jeot whom sealed with aluminum coated paper, was about 18 days in this study.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.2
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• pp.72-92
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• 1996

식물유, 어유 및 축산 폐기물을 포함한 동식물성 기름은 어느 연료든지 기관의 연료로서 사용 가능하지만, 이들 연료는 점도가 높고, 저휘발성이어서 착화지연기간동안에 가연성혼합기 생성이 어려워 저 NOx이며, 정숙한 운전이 사능할 뿐 아니라 경유정도의 열소비율 및 배기 매연농도로 디젤기관의 대체 연료로서의 충분한 가능성이 있는 연료임을 확인하였다. 그러나, 고점도에 의한 분무 특성의 악화에 기인한 분무입자의 증대로 미연소분에 의한 carbon deposit 및 piston ring stick 등이 문제점으로 지적되었다. 그러나, 이같은 문제점의 해결책으로 경질유와의 혼합, 에스테르 변환 및 연료의 가열등 여러 해결책을 제시하였고, 배기가스분석결과도 양호함을 확인하였다. 이같은 biomass 연료 일종인 식물유가 아무런 변화없이 이용되기 위해서는 고과급화, 단열 및 연소실의 적절한 설계가 필요할 것으로 생각된다. 따라서, 현재의 실황을 생각한다면 기존기관을 특별하게 개조함이 없이 사용을 전제로 할 때 식물유의 이용은 local 에너지로서, 생산, 전환 또는 이용기술의 개발과 동시에 화석에너지의 보충적인 에너지로 고려하는 것이 유효할 것으로 생각된다.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.17-23
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• 2007

For the purpose of antibacterial and photocatalystic deodorization functions, the papermaking inorganic fillers and pigments were surface-modified with Ag nano-colloidal solution and $TiO_2$ by using the hybridization technique. The functional specialty sheets and coating papers were produced with the surface-modified fillers and pigments, and evaluated by halo test and inhibition growth test in their antibacterial and photocatalystic characteristics. For the application of specially produced antibacterial handsheet to the wallpaper usages, the photocatalyst efficiency test of benzene in volatile organic compound dissolution experiment of antibacterial and deodorization function wallpaper showed that the efficiency was 45~50% for 80 min of reaction time and 90% of attained resolution was reached at approximately 30 min of response time.

• Journal of Sensor Science and Technology
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• v.11 no.6
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• pp.327-334
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• 2002

Fine particles of $SnO_2$ were fabricated by the sol-gel powder processing using tine(II) chloride dihydrate($SnCl_2{\cdot}2H_2O$) and ethanol($C_2H_5OH$) as raw materials. The powders were investigated about the properties and electrical sensing. Gel powders were fabricated by drying of sol at $120^{\circ}C$ after aging 72hrs and 168hrs. The amount of $SnO_2$ phase was increased below $600^{\circ}C$ due to the elimination of volatile components, and the $SnO_2$ phase was almost completed by the heat treatment at $700^{\circ}C$ for 30min. The grain sizes were about 30nm below $700^{\circ}C$, and it showed the narrow distribution of the grain sizes. The specimens to measure electrical properties were fabricated by the thick film screen printing technique on the alumina substrates. The conductance of $SnO_2$ was showed the intrinsic behaviour of semiconducting ceramics above at $450^{\circ}C$. The constant conductance was observed in the temperature range of $200{\sim}450^{\circ}C$. The sensing properties of response time, recovery, and sensitivity of CO were improved with aging time.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.165-174
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• 2010

The numerical modeling of a coal gasification reaction occurring in an entrained flow coal gasifier is presented in this study. The purposes of this study are to develop a reliable evaluation method of coal gasifier not only for the basic design but also further system operation optimization using a CFD(Computational Fluid Dynamics) method. The coal gasification reaction consists of a series of reaction processes such as water evaporation, coal devolatilization, heterogeneous char reactions, and coal-off gaseous reaction in two-phase, turbulent and radiation participating media. Both numerical and experimental studies are made for the 1.0 ton/day entrained flow coal gasifier installed in the Korea Institute of Energy Research (KIER). The comprehensive computer program in this study is made basically using commercial CFD program by implementing several subroutines necessary for gasification process, which include Eddy-Breakup model together with the harmonic mean approach for turbulent reaction. Further Lagrangian approach in particle trajectory is adopted with the consideration of turbulent effect caused by the non-linearity of drag force, etc. The program developed is successfully evaluated against experimental data such as profiles of temperature and gaseous species concentration together with the cold gas efficiency. Further intensive investigation has been made in terms of the size distribution of pulverized coal particle, the slurry concentration, and the design parameters of gasifier. These parameters considered in this study are compared and evaluated each other through the calculated syngas production rate and cold gas efficiency, appearing to directly affect gasification performance. Considering the complexity of entrained coal gasification, even if the results of this study looks physically reasonable and consistent in parametric study, more efforts of elaborating modeling together with the systematic evaluation against experimental data are necessary for the development of an reliable design tool using CFD method.

• Food Science and Preservation
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• v.20 no.4
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• pp.554-563
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• 2013

The changes in quality properties and nutritional components for two mugworts, namely, Artemisia capillaris Thumberg Artemisiae asiaticae Nakai fermented by Bacillus strains were characterized followed by rapid pattern analysis of volatile flavor compounds through the SAW-based electronic nose sensor in the GC system. After fermentation, the pH has remarkably decreased from 6.0~6.4 to 4.6~5.1 and there has been a slight change in the total soluble solids. The L (lightness) and b (yellowness) values in the Hunter's color system significantly decreased, whilst the a (redness) value increased via fermentation. The HPLC analysis demonstrated that the total amino acids increased in quantity and the essential amino acids were higher in the A. asiaticae Nakai than in the A. capillaris Thumberg, specially with high contents of glutamic and aspartic acid. After fermentation, the monounsaturated fatty acid increased in the A. asiaticae Nakai and the polyunsaturated fatty acids increased in the A. capillaris Thumberg. While the total polyphenol contents have not been affected by fermentation, the total sugar contents have dramatically decreased. Scopoletin, which is one of the most important index components in mugworts, was highly abundant in the A. capillaris Thumberg; however, it was not detected in the A. asiaticae Nakai. Small pieces of plant tissue in the surface microstructure were found in the fermented mugworts through the use of the scanning electron microscope (SEM). Volatile flavor compounds via electronic nose showed that the intensity of several peaks has increased and additional seven flavor peaks have been produced after fermentation. The VaporPrintTM images demonstrated a notable difference in flavors between the A. asiaticae Nakai and A. capillaris Thumberg, and the fermentation enabled the mugworts to produce subtle differences in flavor.