• 한국수소및신에너지학회논문집
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• 제23권5호
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• pp.493-502
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• 2012

Syngas laminar burning velocity measurements were carried out at atmospheric pressure and ambient temperature using the Bunsen flame configuration with nozzle burner as a fundamental study on flame stability of syngas fuel. Representative syngas mixture compositions ($H_2$:CO) such as 25:75%, 50:50% and 75:25% and equivalence ratios from 0.5 to 1.4 have been conducted. Average laminar burning velocities have been determined by the stabilized nozzle burner flames using the angle method, radical surface area method and compared with the data obtained from the other literatures. And the results of each experimental methodologies in the various composition ratios and equivalence ratios were coincided with the result of numerical simulation. Especially, it was confirmed that there was necessary to choice a more accurate measurement methodology even the same static flame method for the various composition ratios of syngas fuel including hydrogen. Also, it was reconfirmed that the laminar burning velocities gradually increased with the increasing of hydrogen content in a fuel mixture.

• 한국환경과학회지
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• 제17권4호
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• pp.397-403
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• 2008

The purpose of this study is to investigate weighted compaction density according to a leading density in truck, a compaction density of solid waste and composition ratios of solid waste fur calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was $1m^3(1m{\times}1m{\times}1m)$. The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was $0.264\;ton/m^3$ ($0.113{\sim}0.487\;ton/m^3$). When the loading density for each compositions was compared, the composition of the highest average loading density ($0.474\;ton/m^3$) was miscellaneous wastes. The composition of the lowest average loading density ($0.120 ton/m^3$) was general solid waste. The reported results indicated that the compaction density at the landfill site was $0.538\;ton/m^3$, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from $0.021\;ton/m^3$ to $0.221\;ton/m^3$. When the compaction density for each composition was compared, the composition with the highest average compaction density ($0.221\;ton/m^3$) was miscellaneous wastes. The composition with the lowest average compaction density ($0.021\;ton/m^3$) was general solid wastes.

• 한국유기농업학회지
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• 제8권1호
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• pp.101-109
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• 1999

In order to investigate the possibility of treating the different mixture ratios of apple pomace and nightsoil sludge by vermicomposting was performed and the stability of worm casts, and availability of worm casts as plant growth media was evaluated by the analysis of chemical composition. The results were obtained as follows ; 1. The value of cast production at 100% apple pomace treatment was higher than those of other mixture ratios of apple pomace and nightsoil sludge. 2. The highest values of increasing rate and reproductive efficiency were obtained at mixture ratios of 60% apple pomace with 40% nightsoil sludge. 3. The value of increasing rate at 100% nightsoil sludge treatment was lower that those of other mixture ratios of apple pomace and nightsoil sludge. 4. Organic matter, available inorganic nutrients and stability of worm casts showed high values in all treatments. It means that worm casts are an excellent plant growth media source with a high chemical composition and their stability.

• 한국식품저장유통학회지
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• 제14권1호
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• pp.30-34
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• 2007

불포화지방산의 함량이 많은 오징어 간유의 미세캡슐화 공정을 최적화하기 위하여 부형제 조성을 달리하여 미세캡슐화 특성을 살펴본 결과, 모든 조성비에서 유화액의 점도는 유사한 경향을 나타내었고, Na-caseinate의 함량이 높을수록 유화안정성이 증가하였다. 미세캡슐화 효율은 Na-caseinate와 cyclodextrin의 비율이 4:6 > 6:4 > 5:5 > 3:7 > 7:3의 순으로 4:6 비율이 가장 높게 나타났으나 미세캡슐화된 분말의 흡습성은 cyclodextrin의 함량이 높을수록 증가하였으며, 수분함량과 입도크기는 모든 실험구가 유사하게 나타나 큰 영향이 없었다. 지방산 조성은 모든 조성비에서 고도불포화지방산이 50% 이상으로 나타났으며, Na-caseinate와 cyclodextrin의 혼합비가 4:6으로 제조된 분말의 포화지방산에 대한 고도불포화지방산의 비율이 2.11로 높게 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제21권2호
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• pp.57-65
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• 1993

The aim of this research was to manufacture sludge-particle board using paper sludge with wood particle and to investigate physical and mechanical properties of various sludge-particle boards, fabricated with ratios of sludge to particle of 10 to 90, 20 to 80, 30 to 70, 40 to 60 and 50 to 50(oven dry weight based). Sludge-particle boards were manufactured by urea-formaldehyde resin, 0.8 target specific gravity, and 10mm thickness. It was possible to manufacture sludge-particle board as the same processing in the present particleboard manufacturing system. This sludge-particle board have different properties as composition ratios of sludge and particle. And sludge-particle board made from 10 percent to 20 percent of sludge mixing ratio have similar mechanical properties compared with control particleboard. Especially, the sludge-particle board made from 10 percent to 40 percent mixing ratios of sludge have superior to control particleboard in internal bond, screw withdrawal holding strength and modulus of elasticity. In the case of dimensional stability, water absorption was increased and thickness swelling was decreased as increased with sludge mixing proportion. The sludge-particle board made of different mixing ratios of our laboratory design was able to concluded that there is possibility of partial substitution of wood particle materials.

• Animal Bioscience
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• 제34권5호
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• pp.895-903
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• 2021

Objective: The objective of this study was to investigate the effects of various dietary unsaturated to saturated fatty acids ratios (UFA to SFA ratios) on growth performance, carcass traits, blood lipid parameters, tissue fatty acid (FA) composition, and meat quality of finishing pigs. Methods: A total of 45 crossbred pigs ([Duroc×Landrace]×Yorkshire), with an average initial body weight of 60.3±2.4 kg, were randomly allocated to three treatment groups of 1:1, 2:1, and 3:1 dietary UFA to SFA ratios. Results: Both average daily gain and average daily feed intake of pigs were decreased linearly (p<0.05), whereas backfat thickness was decreased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Serum triglyceride and low density lipoprotein cholesterol were decreased quadratically or linearly (p<0.05) respectively, whereas high density lipoprotein cholesterol was increased quadratically (p<0.05) with increasing dietary UFA to SFA ratio. In M. longissimus thoracis, the proportion of C18:1 and monounsaturated FA was decreased linearly (p<0.05), whereas the proportion of C18:2n-6, C20:4n-6 and polyunsaturated FA (PUFA) were increased linearly (p<0.05) as dietary UFA to SFA ratio increased. In the subcutaneous adipose tissue, the proportion of SFA was decreased linearly (p<0.05), whereas the proportion of n-6 PUFA, n-3 PUFA, and the UFA to SFA ratios were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Meat color scores and shear force of pigs were decreased linearly (p<0.05), whereas drip loss and cooking loss were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Conclusion: Appropriately boosted dietary UFA to SFA ratio could be conductive to optimize blood lipid parameters and tissue FA composition. However, when the ratio is too high or too low it tends to have negative effects on growth performance and meat quality.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.220-229
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• 2016

A numerical study on lifted flame structure in impinging jet geometry with syngas composition ratio was investigated. The numerical calculations including chemical kinetic analysis were conducted using SPIN application of the CHEMKIN Package with Davis-Mechanism. The flame temperature and velocity profiles were calculated at the steady state for one-dimensional stagnation flow geometry. Syngas mixture compositions were adjusted such as $H_2:CO=10:90(10P)$, 20 : 80 (20P), 30 : 70 (30P), 40 : 60 (40P), 50 : 50 (50P). As composition ratios are changed from 10P to 50P, the axial velocity and flame temperature increase because the contents of hydrogen that have faster burning velocity increase. This phenomenon is due to increase in good reactive radicals such as H, OH radical. As a result of active reactivity, the burning velocity is more faster and this is confirmed by numerical methods. Consequently, combustion reaction zone was moved to burner nozzle.

• 자원환경지질
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• 제57권3호
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• pp.343-352
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• 2024

경복궁 전각 청기와에 사용된 납유의 발색 원리와 용융제로 사용된 납의 산지를 확인하기 위해 성분 분석과 납동위원소비 분석을 실시했다. 청기와 31점을 녹색, 청색, 황색으로 구분하여 표면에 시유된 납유의 성분을 분석한 결과 Pb, Si, Cu가 주성분으로, Fe, Ca, Mg, Al 등이 미량으로 검출되었다. 청색 납유에서는 Cu의 함량이 높았으며 황색 또는 갈색의 납유에서는 Cu는 검출되지 않았고 Fe의 함량이 높게 나타났다. 따라서 납유의 제작에 용융제로 납을, 발색제로 산화동을 사용했음을 알 수 있었다. 또한 경복궁 청기와에 사용된 납유의 납동위원소비는 한반도 납동위원소비 분포도에서 충청도와 전라도를 포함하는 zone 3 영역에 도시되었으며, 납유의 용융제는 이들 지역에서 산출되는 방연석 등을 사용했을 것으로 추정된다. 삼국과 통일신라시대 녹유의 납동위원소비는 대부분 한반도를 벗어나 위치하여 납의 산지가 변화되었음을 알 수 있었다. 특히 녹유 전돌의 납동위원소비를 통해 주변국과의 교류를 추정할 수 있었으며 동일 사찰에서 출토된 녹유 전돌의 납동위원소비가 서로 달라 다른 시기 또는 다른 공방에서 제작된 것으로 판단할 수 있었다.

• Nutritional Sciences
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• 제5권4호
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• pp.184-189
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• 2002

The effects of dietary Int levels on lipid metabolism under fixed P/S (1.3) and n-6/n-3 (5.1) fatty acid ratios were examined in rats using palm oil, soybean oil and perilla oil. These ratios correspond to the recommended composition of dietary fat for humans. The range of dietary fat levels was 5-20% by weight (11.8-39.3% of total energy). The levels of dietary fat did not influence the concentrations of serum and liver cholesterol, whereas the level of triglycerides was gradually elevated with increasing levels of dietary fat, especially in the liver. The fatty acid composition of tissue phosphatidylcholine seemed to vary with the different levels of fat. The ratio of linoleic acid to arachidonic acid was increased more significantly in the heart than in the liver. In adipose tissue total lipids, the percentages of saturated and monounsaturated fatty acids decreased, whereas the percentage of polyunsaturated fatty acid increased, with increasing dietary Int levels. In addition, though the level of aortic prostacyclin was not uniformly affected by increasing dietary fat levels, thromboxane A2 production by platelets tended to increase with higher levels of dietary fat, suggesting an increased risk of thrombosis in this situation. Thus, even though dietary fat may have desirable compositions of fatty acids, these excessive consumption can produce unfavorable metabolic responses.

• 한국전기전자재료학회논문지
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• 제16권4호
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• pp.317-321
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• 2003

In this study, the structural properties were Investigated for the deposited (Ba,Sr)(Nb,Ti)O$_3$[BSNT] thin films grown on Pt/TiO$_2$/SiO$_2$/Si substrate by RF sputtering method. The structural properties of the BSNT thin films affected by the Ar/02 ratios were Investigated. In the case of the BSNT thin films deposited with condition of 60/40(Ar/O$_2$) ratio, the BaTiO$_3$, SrTiO$_3$ and BaNbO$_3$ phases were showed. The composition ratio of Nb and Ti in the BSNT thin films were nearly equivalent. Also, in the BSNT thin films deposited with condition of 60/40 and 80/20(Ar/O$_2$) ratios, the composition of Ba, Sr, Nb and Ti were relatively uniform. The Ba, Sr, Nb and Ti in the BSTN thin films were not diffused into the Pt layer.