• 한국가스학회지
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• 제12권3호
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• pp.81-84
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• 2008

본 연구는 현재 상용화를 추진중인 Propane-DME(dimethyl ether) 혼합가스를 가정용 가스레인지에 적용하였을 경우 각 버너에서의 열효율 특성이 KS 기준에 부합되는지를 알아보기 위하여 국내 4개사의 가정용 가스레인지를 대상으로 Propane 100%인 가스와 Propane-DME 혼합비율이 $80%{\sim}20%$(wt.%)인 혼합 가스에 대하여 실험을 수행하였다. 실험결과, DME의 발열량이 낮아 DME 혼합비율이 높아질수록 열효율은 감소하는 것을 알 수 있었다. 또한, 4개사 중 1개사의 제품은 Propane-DME 혼합비율이 $80%{\sim}20%$(wt.%)인 혼합가스를 사용하였을 경우 열효율이 KS 기준인 40%에 미치지 못하는 것으로 나타났다. 이에, Propane-DME 혼합비율이 $80%{\sim}20%$(wt.%)인 혼합가스를 가정용 가스레인지에 적용하기 위해서는 적정한 기준개발이 요구된다.

• 한국식품영양학회지
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• 제36권4호
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• pp.244-252
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• 2023

This study was conducted to provide basic data on the antioxidant activity, inhibition of adipocyte differentiation and reactive oxygen species (ROS) production of a mixture of Brassica juncea extract (BJE) and fermented black rice fraction (BRF). We investigated the total phenol content, total flavonoid content, antioxidant effects (DPPH radical scavenging, ABTS radical scavenging, reducing power, FRAP and ORAC assay) and anti-obesity activity of the mixture in 3T3-L1 cells. Our results showed that the total phenol and flavonoid content increased with increasing BRF mixture ratio. The antioxidant activity increased as the BRF mixture ratio increased. In addition, BJE and BRF mixtures did not show any cytotoxicity during the 3T3-L1 differentiation period. During adipocyte differentiation, BJE and BRF mixtures significantly inhibited lipid accumulation and ROS production compared to the control group. These results warrant further experiments to develop an anti-obesity functional food using a mixture of BJE and BRF.

• 대한토목학회논문집
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• 제32권1D호
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• pp.33-39
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• 2012

겨울철의 영하의 날씨와 잦은 눈으로 인해 도로 포장의 파손이 증가하고 있다. 본 연구에서는 도로 포장의 동결융해 메커니즘을 살펴보고, 다양한 평가 방법을 통해 배수성 아스팔트 포장의 동결융해 저항성을 평가하였다. 동결융해 저항성의 평가방법은 강성 포장과 연성 포장이 각각의 특성에 따라 다양한 평가 방법을 사용하고 있다. 본 연구에서는 변형률의 측정, 수정 로트만 실험, 반복 동결융해 실험, 표면 박리 저항성 실험과 같은 강성 포장과 연성 포장의 대표적인 동결융해 저항성 실험을 적용하여 평가를 실시하였다. 연구결과 배수성 아스팔트 콘크리트는 20%의 공극으로 인해 밀입도 아스팔트 콘크리트에 비해 온도에 따른 변형이 작은 것으로 평가되었다. 또한, 수분의 영향을 받는 동결융해 반복 실험에서도 수분의 원활한 배수와 수분의 동결 시 발생하는 팽창압을 분산시킬 수 있는 충분한 공극으로 인해 다른 종류의 아스팔트 혼합물에 비하여 동결 융해 저항성이 우수한 것으로 나타났다.

• 품질경영학회지
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• 제44권2호
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• pp.245-264
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• 2016

Purpose: This article focuses on the reviewing the papers published in the Journal of the Korean Society for Quality Control (JKSQC) and the Journal of the Korean Society for Quality Management (JKSQM) since 1965, in the area of design of experiments. In this paper, moreover, some other contents of another statistical quality control areas is included. Methods: The reviewed articles are classified into the three main categories: theory and application of experimental designs, response surface methodology and mixture experiments, and roust designs. Some omitted papers in the other areas of reviewing works are also included in this paper, and the contents and relationships of the published articles are examined and summarized in each sub-field. Results: We summarize the reviewed papers in the chronological road-maps for each sub-field, and outline the relations of the connected papers. We provide comments on the contents and the contributions of the reviewed papers. The future direction of the research in the theory and application areas of experimental designs can be provided by the contents of this research. Conclusion: The diverse topics on the improving the quality in the various industry fields are studied and published on the theory, methodology and the empirical application in the fields of designs of experiments. We can see that the Korean Society for Quality Management (KSQM) has tremendously contributed on the improvement of quality in the manufacturing and service industries by publishing the reviewed articles in this paper.

• Natural Product Sciences
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• 제10권3호
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• pp.134-139
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• 2004

In this study, an immunoactivity of panaxtriol ginsenosides Re and Rg1 against infection due to Candida albicans was investigated. The ginsenosides were extracted from Red Ginseng with 85% ethanol and heat-treatment and were analyzed by HPLC on water-acetonitrile as a mobile phase. The HPLC analysis revealed that the extract contained ginsenosides Re and Rg1, which were eluted as a combined peak. By agar diffusion susceptibility, the mixture of Re and Rg1 had no growth-inhibitory activity on C. albicans yeast cells. However, in animal tests BALB/c mice given the mixture of Re and Rg1 intraperitoneally (Lp.) before intravenous (Lv.) infection with live C. albicans yeast cells had longer mean survival times (MST) than MST of control mice groups that received only buffer solution instead of Re and Rg1. In experiments 60% of the ginsenosides-treated mice survived the entire duration of the 50-day observation. The Re and Rg1 mixture induced production of nitric oxide when interacted with RAW 264.7 macrophage cell line. In addition, the mixture caused morphological change of the macrophages. These data indicate that immunostimulation by the Re and Rg1 may be responsible for the protection of mice against disseminated candidiasis.

• 한국안전학회지
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• 제24권5호
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• pp.13-20
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• 2009

The risk assessment of thermal hazard to identify chemical or process hazard during early process developments have been considered. The early identification of thermal hazards associated with a process, such as rapid heats of reaction, exothermic decompositions, and the potential for thermal runaways before any large scale operations are undertaken. This paper presents to evaluate the safe operating parameters/envelope for exist plant operations. The assessment of thermal hazard with operating conditions such as amount of process materials, inhibitor, and catalyst on esterification process in manufacture of concrete mixture agents are described. The experiments were performed by a sort of calorimetry with the Multimax reactor system as a screening tool. The aim of the study was to evaluate the thermal risk of process material and mixture in terms of safety security to be practical applications in esterification process. It suggested that we should provide the thermal hazard of reaction materials to present safe operating conditions with cause of accident through this study.

• 대한토목학회논문집
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• 제35권2호
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• pp.465-470
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• 2015

에폭시 아스팔트 혼합물은 에폭시 수지와 경화제의 화학반응이 진행되어 양생시간을 거쳐 성능 발현이 이루어진다. 에폭시 아스팔트의 양생수준은 후속공정의 진행과 교통개방 및 공정계획의 수립에 절대적인 영향을 미치므로 정확한 예측모델의 개발이 중요하다. 본 연구에서는 기존 예측식에 사용되는 인자들의 화학적 의미 분석을 통하여 에폭시 수지의 농도와 경화특성을 반영하여 기존식보다 확대된 적용 범위를 갖는 양생수준 예측식을 제시하였다. 실외양생 실험과 비교 결과 상관계수가 0.971 이상으로 나타나 조성이 다른 에폭시 아스팔트 혼합물의 온도와 시간에 따른 양생수준을 예측할 수 있는 것으로 나타났다.

• 대한기계학회논문집B
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• 제26권12호
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• pp.1692-1698
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• 2002

A diesel engine has various merits such as high thermal-efficiency, superior fuel consumption and durability. Therefore the number of diesel engine in the world is increasing. As the seriousness of environmental pollution increases in the world, the method to reduce the noxious materials of $CO_2$, NOx and P.M. is very important subject to correspond to exhaust gas regulations. A new concept, so called premixed charge diesel combustion(PCCI), is focused among the various corresponding manners. In this study, we investigated the mixture formation within the cylinder with injection timing using GTT simulation code and also compared combustion characteristics of PCCI engine with that of commercial diesel engine. From this experiments, it could be found that homogeneous mixture formation was observed according to advance of injection timing and simultaneous reduction of NOx and Soot in injection timing of BTDC 60$^{\circ}$.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.26-30
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• 2002

A droplet fractionation method was previously developed to concentrate a dilute nonfoaming protein solution. In that earlier study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a nonfoaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of 5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet fractionation experiment.

• 한국지반환경공학회 논문집
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• 제2권2호
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• pp.33-39
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• 2001

굴패각을 혼합한 해성점토를 매립재료로 활용하기 위한 기초자료를 얻기 위해 삼축실험을 실시하여 혼합토의 전단 변형특성을 검토했다. 일련의 실험을 통해, 굴패각의 혼합율이 증가하면 이종혼합토의 강도가 증가한다는 것을 알 수 있었다. 그리고, 이러한 강도개선 효과는 순수점토와 같이 구속압에 기인한 마찰력뿐만 아니라, 굴패각의 골격 구조 및 형성과정에 의해서도 영향을 받고 있다는 것을 알 수 있었다. 또한, 혼합토의 할선탄성계수 및 다일러턴시 특성으로부터 굴패각 혼합에 의해 나타나는 영향을 파악하였고 보정계수의 개념을 도입해 전단과정의 굴패각 골격구조의 변화를 고찰했다.