• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.588-595
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• 2020

This study examined the catalytic property of Ni-catalyst used in the gas purifying process to manufacture inert gases of N2 and Ar with high-purity over 9N for semiconductor industrial applications. Two types of Ni-catalysts with a cylindrical shape (C1) and churros shape structure (C2) were compared for the assessment. Optical microscopy and FESEM were used to analyze the shape and microstructure of the Ni-catalyst. EDS, XRD, and micro-Raman characterization were performed to examine the composition and properties. BET and Pulse Titration analyses were conducted to check the surface area and catalytic property of the Ni-catalyst. From the composition analysis results, C1 contained a relatively large amount of graphite as an impurity, and C2 contained higher Ni contents than C1. From specific surface area analysis, the specific surface area of C2 was approximately 1.69 times larger than that of C1. From catalytic property analysis, outstanding performance in O₂ and CO impurity removal was observed at room temperature. Therefore, C2, having low-impurity and large specific surface area, is a suitable catalyst for the high-purity inert gas process in the semiconductor industry because of its outstanding performance in O₂ and CO impurity removal at room temperature.

• Journal of Life Science
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• v.26 no.12
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• pp.1477-1486
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• 2016

Lactulose (4-O-${\beta}$-D-galactopyranosyl-D-fructose) is a non-digestible synthetic ketose disaccharide which can used in food and pharmaceutical fields due to its useful functions for encephalopathy, chronic constipation, hyperammonemia, etc. Therefore, the lactulose is regarded as one of the most important disaccharides and have been concentrated much interesting as an attractive functional material in the current industry. From this reason, the research related on the production of lactulose has been carried out various academic and industrial research groups. To produce lactulose, two main methods, chemical production and enzymatic production have been used. Commercially lactulose produced by alkaline isomerization of lactose as chemical production method but it has many disadvantages such as rapid lactulose degradation, purification, and waste management. From these reasons, lactulose produced by enzymatic method which solves these problems has been suggested as a proper method for lactulose production. Two different enzymatic methods have been reported as methods for lactulose production. Lactulose can be obtained through hydrolysis and transfer reaction catalyzed by a ${\beta}$-galactosidase which requires fructose as co-substrate and exhibits a low conversion. Alternatively, lactulose can be produced by direct isomerization of lactose to lactulose catalyzed by cellobiose 2-epimerase which requires lactose as a single substrate and achieves a high lactulose yield. This review summarizes the current state of lactulose production by chemical and biological methods.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.453-466
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• 2020

As the demand for eco-friendly energy increases to overcome the energy shortage and environmental pollution crisis, hydrogen economy has been proposed as a potential solution. Accordingly, an economical and efficient hydrogen production is considered to be an essential industrial process. Research on applying hydrogen separation membranes for H₂/CO₂ separation to the production of highly concentrated hydrogen by purifying H₂ and capturing CO₂ simultaneously from synthetic gas produced by gasification is in progress nowadays. In high temperature environments, the membrane separation process using glassy polymeric membrane with H₂ selectivity has the potential for CO₂ capture performance, and is an energy and cost effective system since polybenzimicazole (PBI)-based separators show excellent chemical and mechanical stability under high-temperature operation conditions. Thus, the development of high-performance PBI hydrogen separators has been rapidly progressing in recent years. This overview focuses on the recent developments of PBI-based membranes including structure modified, cross-linked, blended and carbonized membranes for applications to the industrial hydrogen separation process.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.2
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• pp.19-29
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• 2011

Due to the development of web technologies and the increasing use of smart devices such as smart phone, in recent various web services are widely used in many application fields. In this environment, the topic of supporting personalized and intelligent web services have been actively researched, and an analysis technique on a web-click stream generated from web usage logs is one of the essential techniques related to the topic. In this paper, for efficient analyzing a web-click stream of sequences, a sequential pattern mining technique is proposed, which satisfies the basic requirements for data stream processing and finds a refined mining result. For this purpose, a concept of interesting sequential patterns with a time-interval constraint is defined, which uses not on1y the order of items in a sequential pattern but also their generation times. In addition, A mining method to find the interesting sequential patterns efficiently over a data stream such as a web-click stream is proposed. The proposed method can be effectively used to various computing application fields such as E-commerce, bio-informatics, and USN environments, which generate data as a form of data streams.

• Proceedings of the KGS Conference
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• 2002.05a
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• pp.49-53
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• 2002

국토의 효율적 이용과 여가공간의 개발에 있어서 산악지형의 개발 잠재력은 무궁무진하다고 볼 수 있다. 그간에 산악지형의 개발은 관광자원으로서의 활용이라는 견지에서 무분별한 개발과 자연환경 훼손을 방치해왔던 것이 사실이다. 산악지형의 관광자원 활용은 그 범위에 있어서나 방법에 있어서 매우 다양한 방식을 채택할 수 있다. 한국의 산이 보유하고 있는 자연경관과 문화유적이 접목된 명산사찰을 활용한 문화관광, 자연자원의 보존과 경제 개발, 도시민의 위락 여가공간 제공이라는 세 가지 목적을 동시에 충족시킬 수 있는 산악형 자연공원, 동계스포츠 활동을 위한 스키리조트의 개발과 이용, 마지막으로 산악지형의 경제 발전을 위한 대체산업 육성이라는 취지 하에 등장한 산지 카지노리조트 등 사회, 문화, 경제, 보건, 오락 등 산지는 그 효용성을 날로 더해가고 있다. 산은 더 이상 인간과 격리된 공간이 아니라, 인간의 생활 공간이자 휴식공간이며, 다양한 여가행위를 위한 공간이다. 유럽 등 구미 관광 선진국에서는 이미 산악지형 고유의 경제적, 사회적 중요성에 입각하여 공간의 효율적인 정비를 통해 합목적적이고 친환경적인 산악형 리조트 건설을 통해 지속적인 개발을 추진하고 있으며, 개발에 일부제약이 뒤따르기는 하지만, 관광개발을 위해서 환경보존을 필수적인 조건으로 인식하고 있다. 다시 말하면 관광개발과 환경보존은 불가분의 관계에 놓여있다는 것이다. 따라서 산이 우리에게 가져다주는 이로운 점을 생각할 때 인간의 지나친 개발욕구와 몰지각한 자원활용을 위한 관점에서 산을 보아서는 아니될 것이다. 산을 개발하고 정비하여 관광자원으로 활용할 때보다 친환경적인 시각으로 접근해야 하며, 우리의 산이 우리에게 돌려줄 것을 생각하기 보다 우리가 산에게 해주어야 할 것이 무엇인지를 먼저 생각한다면, 산은 우리에게 경제적 이득과 함께 우리의 여가생활을 위한 최적공간으로 다가설 것이다(요약 및 결론에서 발췌)는pocyanidin C-1-3'-3" -3.'S _0-trigallate는 100rM에서 70%의 강한 저해효과를 나타냈으며,epigallocatechin-(4$\beta$$\longrightarrow$8)-epigallo-catechin-(4$\beta$$\longrightarrow$8)-catechin는 51%의 저해효과를 나타내었다. 산업적응용을 위해 분획한 폴리페놀군은 미백효과 검증실험인 tyrosinase 저해율 측정평가에서 폴리페놀 함량이 가장 높은 Fraction 111의 경우 Sooppm에서 74.2%의 높은 저해율을 나타내었다. 항산화력 실험에서는500pw1이상에서 강한 활성능을 보인 SOD 유사활성능을 제외한 나머지 DPPH와 xanthine oxidase 저해효과에서는 Fraction II와III 모두가50ppm이상에서 80% 이상의 높은 유리라디칼 소거능력을 나타내었다. 그리고 각 Fraction별 항균력 측정 결과 Fraction 르와 111이 우수하게 나타났고 항균활성은 그람음성균보다 그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.min/+}$계 수컷 이형접합체 형질전환 마우스에 AIN-76A 정제사료만을 투여한 대조군은 1.40$\pm$0.24(100%)에 비하여 I3C 저농도 투여 실험군(Group 1; 0.85$\pm$0.23; 61%, P<0.01), 그리고 I3C 고농도 투여 실험군(Group 2 ; 1.32$\pm$0.2

• Clean Technology
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• v.18 no.3
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• pp.229-249
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• 2012

At present, global warming and depletion of fossil fuels have been one of the big issues which should be solved for sustainable development in the future. CCS (carbon capture and sequestration) technology as the post $CO_2$ reduction technology has been considered as a promising solution for global warming due to increased carbon emission. However, the environmental and ecological effects of CCS have drawn concerns. There are needs for noble post reduction technology. More recently, CCU (carbon capture and utilization) Technology, which emphasizes transforming carbon dioxide into value-added chemicals rather than storing it, has been attracted attentions in terms of preventing global warming and recycling the renewable carbon source. In this paper, various technologies developed for carbon dioxide conversion both in gas and liquid phase have been reviewed. For the thermochemical catalysis in gas phase, the development of the catalytic system which can be performed at mild condition and the separation and purification technology with low energy supply is required. For the photochemical conversion in liquid phase, efficient photosensitizers and photocatalysts should be developed, and the photoelectrochemical systems which can utilize solar and electric energy simultaneously are also in development for more efficient carbon dioxide conversion. The energy needed in CCU must be renewable or unutilized one. CCU will be a key connection technology between renewable energy and bio industry development.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.397-406
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• 2019

The purpose of this study was to develop the evaluation scale according to the major selection attribute of culinary major students. For the scale development, 69 items were extracted through theoretical review. After that, a survey was conducted on 73 students who are currently studying culinary majors, and two culinary majors and three culinary major professors conducted in-depth analysis and refining. The questionnaire was conducted from March 18 to March 27, 2019, and the second expert group survey was conducted from August 19 to August 31, 2019 based on Kendall's W-validated mean and standard deviation. The results of this study are as follows. First, 46 properties were derived from the first expert group survey. Second, six factors and 32 attributes were derived through consultation with the second and third expert groups. Thirdly, through the verification of Kendall's W attributes of 32 six factors, verification of consensus on the importance of experts was made, and the final four factors (individual factors, occupational factors, major characteristics factors, and university-related factors) were derived. It was. The results of this study suggest that the final composition of the culinary major selection attribute is expected to contribute enough to increase student satisfaction, school loyalty, and enrollment rate of students through the measurement scale to grasp the competitiveness of the culinary major.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.342-345
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• 2019

The standards for the contents of glyphosate and glufosinate in foods are specific and well categorized. However, the standard of content in animal feeds is relatively inadequate and the classification is insufficient. There is also constant debate about the risk of glyphosate and glufosinate to human health, but the risk to animals has not been well studied. In this study, we established an analytical method in feeds that is estimated to be the path for animals to ingest glyphosate. The solvent extraction was carried out using 25% methanol. After centrifugation, samples were purified using solid phase extraction (SPE) and quantitatively analysed using LC-MS/MS after concentrated. Assessment of validation was conducted through detection limits, accuracy, and precision tests. The detection limits for the established method were 1.8 of ${\mu}g/kg$ of glufosinate and $2.4{\mu}g/kg$ of glyphosate. Accuracy was ranged from 94.4% to 103.4% and precision was range from 1.5% to 7.2%. Glufosinate was detected in one sample ($ND{\sim}8.8{\mu}g/kg$) and glyphosate was detected in all but one sample ($ND{\sim}337.0{\mu}g/kg$) by applying the analytical method to animal feeds (n=13).

• Food Engineering Progress
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• v.13 no.4
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• pp.262-268
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• 2009

A dark brownish pigment in the crude polysaccharide from Auricularia auricula was adsorbed by activated charcoal. The leaching of the pigment adsorbed on activated charcoal and regeneration of activated charcoal used was investigated with eight kinds of solvents. The highest leaching capacity was obtained with the alkaline solution (KOH). The optimum volume of 1 M KOH solution per activated carbon was 45 mL/g, and the treatment for 10 min during single stage leaching was sufficient to achieve the leaching equilibrium. Second-order kinetic model provided the best fitting for the pigment leaching. The pigment leaching capacity of 88.9% was obtained by seven times of treatment with 1 M KOH solution at 25$^{\circ}C$, while at 95$^{\circ}C$, leaching capacity of 82.6% was achieved with single stage alone showing the significant increase of leaching capacity with increasing temperature. The regenerated activated charcoal was nearly as effective as fresh activated charcoal in pigment adsorption of crude polysaccharide from Auricularia auricula.

• Food Science and Industry
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• v.55 no.1
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• pp.58-73
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• 2022

Due to the recent demand for low-calorie foods, consumers are looking for alternative sweeteners that can control blood sugar, low risk of tooth decay and low calories. Regulations for permitted sweeteners in food vary from every country, and it is important for the government and the food industry to monitor products containing these sweeteners to ensure global compliance. Therefore, rapid, precise, and accurate analysis for food matrices should be applied to quality control, market surveillance, monitoring, and evaluation of food additive intake in the food industry. To analyze sweeteners simultaneously, it is essential to develop an efficient and rapid analytical method and to perform appropriate pretreatment steps such as solvent extraction and purification. This study presented the recent analysis trends about the suitable extraction method for food matrices focusing on non-nutritive sweeteners. Additionally, techniques for multi-compounds analysis using HPLC and LC-MS/MS and non-destructive analysis techniques using FT-IR were comprehensively described.