• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.510-516
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• 2016

This study examines the effects of linear alkylbenzene sulfonate on hydrogen fermentation of food waste. The hydrogen production rate was similar with different linear alkylbenzen sulfonate (LAS) concentrations. The maximum hydrogen yield increased with increasing LAS concentration. The highest maximum hydrogen yield was $0.550{\pm}0.005mol$ H2/mol hexose at LAS for 5.52 mg/L. But the maximum hydrogen yield decreased above LAS for 11.05 mg/L. The concentration of acetate in control reactor was increased, but it decreased with increasing LAS concentration in other reactors.

• Structural Engineering and Mechanics
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• 제58권4호
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• pp.677-687
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• 2016

On the basis of the energy approach it is reported a development of the yield function and the constitutive equations for the orthotropic material with consideration of the crystal lattice constants and parameters of the crystallographic texture for the general stress state. For practical use in sheet metal forming analysis it is considered different loading scenarios: plane stress and plane strain states. Using the proposed yield function, the influence of single ideal components on the shape of yield surface was analyzed. The six texture components investigated here were cube, Goss, copper, brass, S and rotated cube, as these components are typically observed in rolled sheets from FCC alloys.

• 한국의류학회지
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• 제13권1호
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• pp.89-97
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• 1989

Graft polymerization of MMA onto cotton fiber was carried out in two ways, two step graft polymerization and one step emulsion graft polymerization, using tetravalent cerium ion as an initiator. At two step graft polymerization, the first step was the pretreatment of cotton fiber with an aqueous initiator solution and the second was the grafting pretreated cotton fiber in the monomer solution. In case of one step emulsion graft polymerization, MMA was emulsified with SLS in initiator solution. Under the various graft polymerization conditions, graft yield, graft efficiency and from the Arrhenius plot the apparent activation energy were compared. The results of this study were as follows: 1. Graft yield and graft efficiency of emulsion graft polymerization were higher than those of two step graft polymerization. 2. In case of two step graft polymerization, graft yield was affected by the pretreatment time of cotton fiber with an aqueous initiator solution. And graft yield of emulsion graft polymerization was increased with the concentration of emulsifier below cmc of SLS and was decreased thereafter. 3. Elevation of temperature resulted increase in graft yield for both grafting methods. The apparent activation energy of emulsion graft pelymerzation was lower than that of two step graft polymerization. 4. Increased reaction time increased in graft yield, but decreased in graft efficiency. 5. Moisture regain of grafted cotton was decreased with graft yield.

• 한국작물학회지
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• 제28권3호
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• pp.351-357
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• 1983

예상요인이 대두에 미치는 영향을 알기 위하여 1976년부터 1981년까지의 강우량, 강수일수, 온도등의 기상요인과 동 기간에 재배한 봉의 품종의 수량을 비롯한 중요 농경형질간의 관계를 조사하여 얻어진 경과를 요약하면 다음과 같다. 1. 중요형질의 년차에 따른 변이계수는 등숙율이 37.9%, 수량 및 주당협수는 30%, 100립중은 5.5%였다. 2. 대두 재배기간 동안의 강우량, 강수일수, 온도 등을 월별로 보면 7, 8월의 기상요인이 생육에 크게 영향을 미치며 그 중 온도조건이 가장 문제가 되었다. 3. 7월의 최고, 최저 및 평균온도와 수량 및 립중, 8월의 최고온도와 수량 및 립중, 8월의 최고, 최저 및 평균온도와 등숙율과는 부의 상관이 있었다. 4. 예상요인과 수량과의 관계를 회귀직선식으로 나타내면 7월의 평균온도와 수량은 y=-42.46X ＋1200.86, 8월의 최고온도와 수량은 y=-37.95X ＋1210.42였다. 5. 중부지방의 맥전작재배지역에서는 개화기에 해당하는 7월 21일부터 7월 31일까지의 고온이 특히 대두의 수량감소를 가져온다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.45-52
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• 1995

광 촉매로 널리 알려진 TiO$_2$의 광 분해 거동의 변화를 관찰하기 위하여 Nb$_2$O$_{5}$를 첨가하여 sol-gel 용법으로 제조한 후 DCA(dichloroacetic acid) 의 광분해 효율을 측정하였다. Sol-gel process 과정에서 첨가된 Nb$_2$O$_{5}$의 농도 및 열처리 온도변화에 따른 광분해 효율을 관찰한 결과, Nb$_2$O$_{5}$를 첨가한 후 40$0^{\circ}C$에서 한시간 동안 열처리 한 광 촉매의 광분해 효율이 가장 높게 나타났다. 또한 열처리 온도와 무관하게 Nb$_2$O$_{5}$의 양이 증가할수록 광분해 효율은 감소하는 것으로 관찰되었다. 이는 excess electron 의 증가로 환원 반응 혹은 recombination rate기 증가하기 때문이라고 사료된다. 분해 대상 물질의 pH가 낮을수록 광분해 효율이 증가하는 것을 알 수 있었다.알 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.173-173
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• 2010

This thesis identified basic design elements (Sustainable Yield, Temperature of Groundwater, Depth of Well, Separation Distance between wells) regarding installation of Standing Column Well, Geothermal Heat pump System by dynamic analysis.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.576-580
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• 2009

This thesis identified basic design elements(Sustained Yield, Depth of Well, Separation Distance between wells) regarding installation of Standing Column Well, Geothermal Heat pump System by dynamic analysis.

• Earthquakes and Structures
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• 제4권4호
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• pp.365-381
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• 2013

In this paper, a numerical simulation study was conducted on the seismic behavior and ductility demand of single-degree-of-freedom (SDOF) systems with partially self-centering hysteresis. Unlike fully self-centering systems, partially self-centering systems display noticeable residual displacement after unloading is completed. Such partially self-centering behavior has been observed in a number of recently researched self-centering structural systems with energy dissipation devices. It is thus of interest to examine the seismic performance such as ductility demand of partially self-centering systems. In this study, a modified flag-shaped hysteresis model with residual displacement is proposed to represent the hysteretic behavior of partially self-centering structural systems. A parametric study considering the effect of variations in post-yield stiffness ratio, energy dissipation coefficient, and residual displacement ratio on the displacement ductility demand of partially self-centering systems was conducted using a suite of 192 scaled ground motions. The results of this parametric study reveal that increasing the post-yield stiffness, energy dissipation coefficient or residual displacement ratio of the partially self-centering systems generally leads to reduced ductility demand, especially for systems with lower yield strength.

• 한국공간구조학회논문집
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• 제6권2호
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• pp.115-121
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• 2006

최근 바람 및 지진에 대한 진동제어를 목적으로 한 저항복점강재를 이용한 댐퍼가 많이 사용되고 있다. 그러나 전체 구조물의 진동에 영향을 미치는 저항복점강재의 동적특성 및 지진에너지 소산효과는 명확히 밝혀지지 않고 있다. 본 연구에서는 저항복점감재에 대한 반복재하실험 결과 및 저항복점감재를 정착한 3층 규모의 구조물에 대하여 실시한 강제진동시험의 결과에 대해 보고한다. 또한 저항복점강재의 지진에너지 소산양의 정량적인 평가를 위하여 수학적 이력형모델 및 등가선형해석법을 이용하여 평가한 결과에 대해 보고한다.

• 한국수소및신에너지학회논문집
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• 제26권1호
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• pp.1-7
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• 2015

In this study, characteristics of reforming process of automotive liquefied petroleum gas (LPG) fuel using plasma reactor are investigated. Because plasma reformer technology has advantages of a fast start-up and wide fuel/oxidizer ratio of operation, and reactor size is smaller and more simple compared to typical combustor and catalytic reactor, plasma reforming is suitable to the on-board vehicle reformer. To evaluate the characteristics of the reforming process, parametric effect of $O_2/C$ ratios, reactant flow rate and metal form on the process were investigated. In the test of varying $O_2/C$ ratio from partial oxidation to stoichiometry combustion, conversion of LPG was increased but selectivity of $H_2$ decreased. The optimum condition of $O_2/C$ ratio for the highest $H_2$ yield was determined to be around 1.0 for 20~50 lpm, and 1.35 for 100 lpm. Specific energy density (SED) was major factor in reforming process and higher SED leads to higher $H_2$ yield. And metal form in the reformer increased $H_2$ yield of about 34 % as compared to the case of no metal form. The result can be a guide to map optimal condition of reforming process.