• Advances in concrete construction
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• 제6권3호
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• pp.269-283
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• 2018

This study presents the effects of geometrical dimensions of concrete gravity dams on the seismic response considering different base width/dam height (L/H) ratios. In the study, a concrete gravity dam with the height of 200 m is selected and finite element models of the dam are constituted including five different L/H ratios such as 0.25, 0.5, 0.75, 1.00, 1.25. All dams are modeled in ANSYS software considering dam-reservoir-foundation interaction. 1989 Loma Prieta earthquake records are applied to models in upstream-downstream direction and linear time history analyses are performed. Dynamic equilibrium equations of motions obtained from the finite element models of the coupled systems are solved by using Newmark time integration algorithm. The seismic response of the models is evaluated from analyses presenting natural frequencies, mode shapes, displacements and principal stresses. The results show that the L/H ratios considerably affect the seismic response of gravity dams. Also, the model where L/H ratio is 1.00 has more desirable results and most appropriate representation of the seismic response of gravity dams.

• Journal of Pharmaceutical Investigation
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• 제27권1호
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• pp.23-27
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• 1997

To investigate the effect of L-arginine as stabilizing agent for omeprazole, the degradation rate constant of omeprazole in aqueous solution was determined at 30, 40 and $50^{\circ}C$ with various ratios of L-arginine to omeprazole. The pH of omeprazole solutions was also determined. As the amount of L-arginine increased, the pH of omeprazole solution also increased, and the solution appeared to be more stable. The omeprazole in aqueous solution could be stabilized by more than 15:1 molar ratio of L-arginine to omeprazole. The stability of omeprazole in commercial products using L-arginine or sodium phosphate dibasic as stabilizing agent was investigated. Among the commercial products, the omeprazole product prepared with L-arginine (molar ratio of L-arginine to omeprazole, 20:1) was most stable.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.199-205
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• 2015

Organic wastes such as food waste (FW), livestock wastewater (LW), and sewage sludge (SWS) can produce hydrogen ($H_2$) by anaerobic acid fermentation. Expecially, FW which has high carbohydrate content produces $H_2$ and short chain fatty acids by indigenous $H_2$ producing microorganisms without adding inoculum, however $H_2$ production rate (HPR) and yield have to be improved to use a commercially available technology. In this study, LW was mixed to FW in different ratios (on chemical oxygen demand (COD) basis) as an auxiliary substrate. The mixture of FW and LW was pretreated at pH 2 using 6 N HCl for 12 h and then fermented at $37^{\circ}C$ for 28 h. HPR of FW, 254 mL $H_2/L/h$, was increased with the addition of LW, however, mixing ratio of LW to FW was reversely related to HPR, exhibiting HPR of 737, 733, 599, and 389 mL $H_2/L/h$ at the ratio of FW:LW=10:1, 10:2, 10:3, and 10:4 on COD basis, respectively. Maximum HPR and $H_2$ production yield of 737 $H_2/L/h$ and 1.74 mol $H_2/mol$ hexoseadded were obtained respectively at the ratio of FW:LW=10:1. Butyrate was the main organic acid produced and propionate was not detected throughout the experiment.

• 한국해양학회지
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• 제21권4호
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• pp.259-264
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• 1986

進行性 有限 振幅波가 수평인 底部 境界面 위에 存在할 때 이 波로 因하여 境界面에 인접해서 形成되는 定常流(steady stream)를 硏究하였다. 이를 위하여 境界層 方程式이 使用되었으며, 이것을 二重 Fourier 系別로 展開함으로써 그 解를 구하였다. 이 解의 垂直, 構造를 水深과 波長의 比(h/L)의 양수로 表示하였다. 有限 振幅波가 가장 잘 適用될 수 있는 條件下에서 境界層의 定常流를 구해본 結果 이 定常波는 물의 粘性에는 無關하며 그 上部에 있는 有限 振幅波의 파라메타들, 즉 週期, 波長등과 水深의 計數임이 確認 되었다. 또 이 境界層의 定常流의 速度는 파속과, 水深에 대한 波高의 比(H/L)의 제곱에 比例함이 밝혀졌으며, 이 正常流의 크기는 h/L이 0.5보다 클때에는 아주 작아져서 無意味한 값이 된다.

• 한국지반환경공학회 논문집
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• 제20권9호
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• pp.13-19
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• 2019

Dynamic earth pressure is considered an important parameter in the design of embedded structures. In current engineering design simplified methods developed either for yielding or non-yielding structures are utilized to predict resultant dynamic pressure. The applicability of these equations to embedded structures have not yet been reported. In this study we perform a suite of equivalent linear time history analysis for a range of embedded structure configurations. Numerically calculated dynamic pressure is shown to depend on the flexibility ratio (F), aspect ratio (L/H) of the embedded structure, and ground motion. Increase in L/H and intensity increases the magnitude of dynamic pressure. An increase in F decreases the dynamic pressure. Overall, the trends highlight the need for development of new method that accounts for F and L/H to calculate the dynamic pressure for the performance-based design of embedded structures.

• 한국식품영양학회지
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• 제31권6호
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• pp.873-882
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• 2018

This research is about the quality characteristics of white bread mixed with varying ratios of Seomcho powder, such as 1%, 3%, 5%, and 7% (Spinacia oleracea L.). The pH level of dough decreased as more Seomcho powder (Spinacia oleracea L.) was added, and 7% addition recorded the lowest pH. The fermentation power of dough expansion decreased as the additional ratio increased in both the first and second proofing, and it was negatively correlated to the fermentation time factor. The moisture content of bread decreased as the addition ratio increased. The bread volume became smaller as the addition ratio increased, but it correlated negatively with its specific volume. The color of the crumb, the lightness and redness decreased in comparison to the control, but the yellowness increased. The total amino acid contents increased as the addition ratio increased, and glutamic acid was positively correlated to the additional ratio. The total free amino acids increased as the additional ratio increased, but cysteine levels were high at 5% and 7% additional ratio. The textural characteristics of the bread, springiness and cohesiveness were lower than the control, but gumminess, brittleness, and hardness were higher than the control. The adhesiveness was realized at 7% additional ratio.

• Journal of Nutrition and Health
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• 제28권8호
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• pp.706-716
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• 1995

This study was undertaken to investigate the influence of age and dietary linolenic acid content and the linolenic acid/linoleic acid (LAN/LA) ratio on the brain lipid composition and membrane-bound enzyme, acetylcholinesterase(AchE) activities. AchE was selected as a test case for the relationship between cell lipid composition and cell membrane function. The male rats were fed diets with 0.2, 0.4, 0.6 of LNA/LA ratio within 8% LNA(H-LNA) or 4% LNA(L-LAN) of total fatty acid content for different feeding period(1, 4, 12 month). The fats used s source were sesame oil, perilla oil, soybean oil and beef tallow. The AchE activity of brain crude synaptosomal fraction was reduced with advancing age, showing 20-30% reduction in 12M compared with 1 M, and the P/C ratio was reduced in old rats. In 1 and 4 monthed rats, AchE activites was higher in H-LAN-0.2 and L-LNA-0.2 and 0.4 group. In accordance with rising of AchE activities was higher in H-LNA-0.2 and L-LNA-0.2 and 0.4 group. In accordance with rising of AchE activities, the PC/PE ratio increasedin those groups. Paricularly in L-LNA, the PC/PE ratio increased as the AchE activites for decline of membrane fluidity with increasing cholesterol and decreasing P/C ratio when rats were old. Also, AchE activity increaed with increasing PC/PE ratio which depended on the dietary LNA/LA ratio within each LNA content. Therefore, it is concluded that the lipid composition of cell membrane influenced the AchE activiteis, which was mediated by aging and the modification of dietary LNA/LA ratio.

• 한국의류학회지
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• 제18권5호
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• pp.615-621
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• 1994

This study was carried out to investigate the effect of clothing habit on physiological adaptation to the change of season. The survey of clothing weight in fall '||'&'||' winter for 2 years, the frequency of cold infection in winter and degree of fatigue was performed with 110 female high school students. The actual condition of clothing and the correlations between clothing weight and cold infection, and between the clothing weight and degree of fatigue were suveyed. The results are followed as; 1. The clothing insulation was nearly same to indoor standard clothing insulation in H hun wearing normal clothing, but was higher 2 clo in S hun clothed uniform. Especially in spite of similar enviromental condition the clothing weight, minimum '||'&'||' maximum and variation of clothing weight for 2 years were showed to be heavier in S hun than H hun. Also indoor thermal sensation felt by the subjects indicated "cold", and the difference between clothing insulation and standard clothing insulation showed increase gradually. 2. L group was indicated to be lower in cold infaction ratio than M '||'&'||' H group, and the correlation between clothing group and cold infection ratio was recognized to be significant (p<0.05). And H hun and L-H group showed to be lower in cold infection ratio than S hun, H-L group. 3. The coefficience between clothing weight and degree of fatigue was recognized to be significant (p<0.05).

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.926-932
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• 2008

Human heavy chain (H-) and light chain (L-) ferritins were amplified from a human cDNA library. Each ferritin gene was inserted downstream of the T7 promoter of bacterial expression vectors, and two types of coexpression vectors were constructed. The expression levels of recombinant ferritins ranged about 26-36% of whole-cell protein. H-ferritin exhibited a lower expression ratio compared with L-ferritin, by a coexpression system. However, the coexpression of HL-ferritins was significantly increased above the expression ratio of H-ferritin by cultivation without IPTG induction overnight. Purified recombinant H-, L-, HL-, and LH-ferritins were shown to be homo- and heteropolymeric high molecular complexes and it was indicated that their assembled subunits would be able to work functionally in the cell. Thus, these results indicate an improvement in the expression strategy of H-ferritin for heteropolymeric production and studies of ferritin assembly in Escherichia coli.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.273-279
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• 1990

PHB 생산을 위하여 메탄올을 기질로 한 선별배지에서 토양, 하천수, 퇴비 등으로부터 분홍색 색소를 가지는 PHB 축적 facultative methylotroph를 분리하여, 균주의 특성을 검토하였다. 분리균주의 최적 생육조건과 PHB 축적을 위한 배양조건을 조사한 결과 균체의 생육은 메탄올 농도 1.0(v/v), 질소원인$ NH_4C$ 농도 1.0g/l, 즉 C/N ratio 13.2 일때 그리고 pH 7.0과'$30^{\circ}C$에서 가장 좋았으며, PHB는 C/N ratio가 50.8, 즉 메탄올 농도 1.0(v/v )$NH_4CL$ 0.26g/l 일때, 그리고 pH 6.0일 때 건조중량의 약 40까지 축적되었다. 고농도 메탄올에 의한 생육저해를 극복하기 위하여 기질을 간헐적으로 계속 공급해주는 fed-batch 배양을 시도한 결과 균체량은 14g/l, PHB 축척량은 5.5g/l까지 증가시킬 수 있었다. 생산된 PHB를 분리.정제하여 IR과 $^I H-NMR$로 구조를 분석한 결과 3-hydroxybutyric acid 의 homopolymer임이 확인되었다. 또한 균주의 pink-pigment를 추출하여 absorption spectrum를 조사하여 그 특성을 규명하였다.