• 한국추진공학회지
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• 제18권5호
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• pp.12-18
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• 2014

공기흡입형 추진기관의 가스발생기에 사용하기 위한 연료과농(Fuel-rich) 고체 추진제의 특성에 대한 연구를 수행하였다. 일반적인 고체 추진제는 평균 60%이상의 산화제를 포함하는 데, 연료과농 고체 추진제를 개발히기 위해 산화제 함량을 30%내외로 낮추고 매우 높은 부피당 열량을 가지는 비정질 붕소를 입자화(Bead)하여 금속연료 함량을 증가시켜 고체 추진제의 제조 공정성 및 연소속도 특성을 확인하였다. 과립화붕소의 입도가 작을수록 추진제 제조 공정에서 초기 점도가 높아지고, 입도가 클수록 연소속도 및 압력지수가 증가하는 것을 확인할 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.263-267
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• 2003

Solid-state fermentation of lovastatin by Aspergillus terreus was investigated using commercially available 1.2 L polypropylene bottle designed for mushroom cultivation. Moist solid raw materials such as com, rice, and soy bean were tested and com was found to be most suitable for an economical production of lovastatin. 50% or higher water addition prior to the sterilization of com was effective for the maximal lovastatin production. About 0.5% (w/w) lovastatin content in dried cells and corn mass was obtained after 20 days of solid-state fermentation at 30$^{\circ}C$. For safety concerns, aflatoxin Bl and citrinin levels after fermentation were assayed but they were not detected. Lovastatin containing cells and corn residue after fermentation were autoclaved, dried, crushed, and fed to chicken for a period of 3 weeks. Approximately 20% reduction of blood cholesterol level of chicken was observed.

• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.132-135
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• 2007

An efficient production method of chlorella extract was developed by enzymatic treatment using cell lytic and proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was found to be 1.0% (w/w). Proteolytic enzymes were screened to obtain high chlorella growth factor (CGF) index, which indicates crude CGF content and solid recovery. Among the seven tested proteases, Esperase, whose optimal dosage was 1.0% (w/w), was selected. By co-treatment using optimal dosages of Tunicase and Esperase, the highest CGF index and solid recovery were obtained. The CGF index and solid recovery of co-treatment were remarkably enhanced by 250 ($4.36{\rightarrow}15.21$) and 220% ($12.65%{\rightarrow}40.15%$), respectively, than those of the non-treated extracts.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.145-146
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• 2017

This research aimed to analyze the fundamental properties of cement mortar accompanying the change of the solid contents of the maintenance type PC water reducing agent. As a result of the experiment, it was found that the properties of fresh mortar show a tendency to decrease as the solid contents decreases in the case of flow and air contents, and the decrease width with time is small. It was found that the compressive strength of the hardened mortar has almost no difference due to the change of the solid fraction.

• Mycobiology
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• 제36권3호
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• pp.183-189
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• 2008

The production of aerial conidia of Lecanicillium lecanii 41185, a highly virulent fungus, by solid-state fermentation was studied for use as a biocontrol agent against aphids. Among several agro-industrial solid media, steamed polished rice was found to produce the highest amount of aerial conidia. The optimal conditions for aerial conidia production were determined to be a 28.5% moisture content in the rice, 25$^{\circ}C$ culture temperature, rice pH of 6.0, 75% ambient relative humidity, 4-dold seeding culture, 0.6% $KNO_3$, and 12 d of culture time. The conidia yield increased from $5.7\times10^9$ conidia/g polished rice to 18.2 $18.2\times10^9$ conidia/g polished rice following application of these optimized conditions.

• 원예과학기술지
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• 제28권4호
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• pp.691-695
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• 2010

포도의 저장 중 소비자 관능평가와 실험에 의한 객관적 품질인자간의 상관성을 통하여 포도 생산의 객관적 지표를 제시하고자 하였다. 포도를 3부위로 나누어 동일부위 절반은 관능검사에 사용하고, 나머지는 분석용 시료로 사용하여 품질요소 간 상관분석을 실시하였다. 저장 기간 중 포도의 이 화학적 품질특성 변화를 보면 가용성 고형물함량은 다소 증가하였으며, 저온저장보다 상온저장에서 더 많은 증가를 보였고, pH 및 적정산도는 저장 중 약간 감소하였으나 처리구간 큰 차이를 나타내지는 않았다. 포도의 객관적 품질평가인자 상호간에는 낮은 상관성을 보여 pH-가용성 고형물함량 간에는 정(+)의 상관을, 적정산도-가용성 고형물함량 및 pH- 적정산도 간에는 부(-)의 상관을 보였다. 포도에 대한 관능평가 항목간의 상관성 분석결과, 신맛과 신맛을 포함한 단맛의 상관성이 0.933로 가장 높은 상관관계를 보였으며, 외관과 단맛과의 상관성이 0.619로 가장 낮았다. 전체적 기호도에 가장 높은 상관관계를 보이는 요인은 조직감($r^2$=0.890)으로 조사되었고, 그 다음이 신맛을 포함한 단맛($r^2$=0.860)이었다. 또한, 관능적인 품질평가 인자와 객관적인 품질인자 간의 상관성 분석결과, 전반적으로 매우 낮았으나 그 중 전체적 기호도에 대한 가용성 고형물함량의 상관성이 다소 높게 나타나, 소비자 관능평가 지표로써의 활용이 가능한 것으로 평가되었다.

• 한국식품저장유통학회지
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• 제2권2호
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• pp.259-268
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• 1995

Physico-chemical components which are closely related to processed products were investigated on 10 varieties of Cheju citrus fruits. Juice ratio of Hungjin was the highest, 49.2%, while Sankyool was the lowest, 4.2%, which showed great differences among varieties. Peel ratio of Dangyooja was the highest, 46.1%, while both Navel orange and Hungjin were relatively low. Soluble solid($^{\circ}$Brix) was relatively high In Sankyool, Meiwa Kumquat, Sambokam and Iyo. Acid content was the highest, 4.86% in sudachi and relatively high in Sankyool, Natsudaidai and Dangyooja. The $^{\circ}$Brix to acid content ratio was 13.9 in Meiwa Kumquat and more than 10 in Navel orange and Hungjin. Total sugar contents of Juice were 2.78∼10.94%, while reduced sugar contents were 1.63∼6.38% which showed higher in Meiwa Kumquat, Iyo and Navel Orange. Hesperidin and naringin, the sources of biiter taste and cloudness were low in Hungjin and Iyo. Soluble solid($^{\circ}$Brix) of citrus juice showed highest statistical relationship(r=0.907) with total sugar, and was highly significant at 1% level.

• Journal of Applied Biological Chemistry
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• 제56권2호
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• pp.119-129
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• 2013

Thirteen different Streptomyces isolates were evaluated for their ability to produce keratinase using chicken feather as a sole carbon and nitrogen sources under solid state fermentation (SSF). Streptomyces sp. NRC 13S produced the highest keratinase activity [1,792 U/g fermented substrate (fs)]. The phenotypic characterization and analysis of 16S rDNA sequencing of the isolate were studied. Optimization of SSF medium for keratinase production by the local isolate, Streptomyces sp. NRC13S, was carried out using the one-variable-at-a-time and the statistical approaches. In the first optimization step, the effect of incubation period, initial moisture content, initial pH value of the fermentation medium, and supplementation of some agro-industrial by-products on keratinase production were evaluated. The strain produced about 2,310 U/gfs when it grew on chicken feather with moisture content of 75% (w/w), feather: fodder yeast ratio of 70:30 (w/w), and initial pH 7 using phosphate buffer after 8 days. Based on these results, the Box-Behnken design and response surface methodology were applied to find out the optimal conditions for the enzyme production. The corresponding maximal production of keratinase was about 2,569.38 U/gfs.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.196-203
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• 2000

In this study, the evaluation method of diffusion characteristics of Suspended Soli&SS) and the generation limit(source and thick) are investigated, which is significantly affecting on marine examined by construction works such as dredging and reclamation. Dispersion characteristics of SS is examined by hydraulic tests and numerical works in consideration with the Pusan Port. Hydraulic model test was performed in 2-D wave flume to find the limit wave conditon of re-suspension of solid as well as the time dependent characteristics of settlement The results obtainded in the study are as follows; 1) The quantituative evaluation af SS is the basic parameter of marine environmental impact assessment in related with the port development The SS increases as the water content of sea bed solid increases and the density decreases. 2) The sea bed solid in Sinsundai area, Pusan Port has the water content range of 83~157% 3) The ratio of suspension velocity against settlement velocity is about 0.25 and SS concentration converges as the wave heigh. 4) The SS increases 2 time when time step increases 3 time(10 sec to 30 sec) in numerical simulation It means that the effect of the time step should be checked in detail to stable. The diffusion The diffusion coefficient are Affiected senstively in the dispersion process while sea ved friction coefficinet have not strong relation in the simulated area

• 한국세라믹학회지
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• 제51권3호
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• pp.224-230
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• 2014

Nano-sized gadolinium-doped ceria (GDC)/nickel particle-dispersed $La_ySr_{1-y}Ti_{1-x}Fe_xO_3$ (LSFTO)-based composite solid oxide fuel cell anodes were fabricated by an infiltration method and the effects of the GDC/Ni nanoparticles on the anode polarization resistance and cell performance were investigated in terms of the infiltration time and nickel content. The anodic polarization resistance of the LSFTO anode was significantly enhanced by GDC and/or Ni infiltration and it decreased with increasing infiltration time and Ni content, respectively. It is believed that the observed phenomena are associated with enhancement of the ionic conductivity and catalytic activity in the nanocomposite anodes by the addition of GDC and Ni. Power densities of cells with the LSFTO and LSFTO-GDC/Ni nanocomposite anodes were 150 and $300mW/cm^2$ at $800^{\circ}C$, respectively.