• Nuclear Engineering and Technology
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• 제28권1호
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• pp.79-92
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• 1996

In a repository containing low-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms and assesses the potential effects of gas generation on the performance of a radioactive waste repository. The metal corrosion model incorporates a three-stage process encompassing aerobic and anaerobic corrosion regimes ; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. A prediction is made for gas concentrations and generation rates over an assessment period of ten thousand years in a radioactive waste repository. The results suggest that H$_2$will be the principal gas generated within the radioactive waste cavern.

• KSBB Journal
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• 제23권1호
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• pp.1-7
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• 2008

The world demand of ethanol as an alternative fuel for gasoline is increasing rapidly because of high oil price and global climate change. Most of ethanol is currently produced from corn grain or sugars in sugarcane and sugar beet. Because these sources compete with foods and animal feed and are not expected to be enough for future demand of ethanol. Thus, cellulosic ethanol from agricultural residues or wood has to be commercialized in near future. Typical cellulosic ethanol production consists of pretreatment, enzyme hydrolysis, fermentation and product separation. This paper reviews the principles and status of each step and discusses issues for cellulosic ethanol production.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제17권12호
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• pp.1179-1183
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• 2007

Electro-Active paper(EAPap) is a new smart material that has a potential to be used in biomimetic actuator and sensor. It is made by cellulose that is abundant material in nature. EAPap is fascinating with its biodegradability, lightweight, large displacement, high mechanical strength and low actuation voltage. Actuating mechanism of EAPap is known to be the combined effects of ion migration and piezoelectricity. However, the electromechanical actuation mechanisms are not yet to be established. This paper presents the modeling of the actuation behavior of water infused cellulose samples and their composite dielectric constants calculated by Maxwell-Wagner theory. Electro-mechanical forces were calculated using Maxwell stress tensor method. Bending deflection was evaluated from simple beam model and compared with experimental observation, and which result in good correlation with each other.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.699-702
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• 2004

Plastic shrindage cracking occurs at the exposed surfaces of freshly placed concrete due to consoilidation of the concrete mass and rapid evaporation of water from the surface. This so called shrindage craking is a major concern for concrete, especially for been performed to obtain the plastic shrindage porperties of cellolus fiber reinforced concrete. The results of tests of the cellolus fiber were compared with plain and polypropylene fibers. Test results indicated that cellolus fiber reinforcement showed an aility to reduce the total crack area and maximum crack width significantly.

• Proceedings of the KIEE Conference
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
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• pp.28-30
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• 2007

본 논문은 변압기의 과부하 상태를 모의하고 내부 절연물의 잔존수명을 평가하기 위한 방법으로 열적 스트레스를 인가한 가속 수명 시험을 수행하여 광유 함침 절연지의 전기적 기계적 열화 특성을 분석하였다. 시험에 사용된 절연 재료는 변압기의 주 절연물로 널리 사용하고 있는 셀룰로스계 크래프트 절연지와 광유계 절연유를 사용하였다. 가속 열열화 시험은 IEEE/ANSI Standard C59.91-1981의 수명 예측 곡선에 의거하여 국내 배전환경에 부합하도록 $55^{\circ}C$ 절연시스템을 기준으로 하였으며, $150^{\circ}C$에서 약 1,000시간 동안 열 스트레스를 인가함으로써 변압기의 수명이 다하도록 모의하였다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1486-1487
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• 2006

본 논문은 변압기의 과부하 상태를 모의하고 내부 절연물의 잔존수명을 평가하기 위한 방법으로 가속 열 열화 시험을 수행하였으며, 광유 함침 절연지의 열 스트레스에 의한 절연 열화 특성을 분석하였다. 시험에 사용된 절연재료는 변압기의 주 절연물로 널리 사용하고 있는 셀룰로스계 크래프트 절연지와 광유계 절연유를 사용하였다. 가속 열 열화 시험은 IEEE/ANSI Standard C59.91-1981의 수명 예측 곡선에 의거하여 국내 배전환경에 부합하도록 $55^{\circ}C$ 절연시스템을 기준으로 하였으며, $150^{\circ}C$에서 약 1,000시간 동안 열 스트레스를 인가함으로써 변압기의 수명이 다하도록 모의하였다. 또한 절연지의 절연 열화 특성을 분석하기 위해 인장강도, 비유전율, 절연파괴 강도를 시험하였다.

• Textile Coloration and Finishing
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• 제32권3호
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• pp.142-149
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• 2020

The purpose of this study was to investigate the dyeing properties of mugwort extract by nano-cellulose(n-cell). When dyeing cotton, rayon(artificial silk, called Ingyeon) and silk with mugwort extract, the difference with and without 2 wt% n-cell which it diluted to 0.6% treatment was compared. It was found that the addition of n-cell changed the values of L^∗, -a^∗(+red ~ -green), and b^∗(+yellow ~ -blue) of all scoured cotton, rayon and silk fabrics, compared to dyeing only mugwort extract. Furthermore, it was confirmed that the ΔE and the K/S value slightly increased in all of the dyed cotton, rayon, and silk fabrics treated with n-cell at the same time as dyeing compared to the untreated ones. Therefore, by treating the fabric with n-cell, a natural cellulose component, at the same time as dyeing, it is expected to maintain stable fastness, which is a disadvantage of dyeing using natural dyes, and contribute to the utilization and commercialization of other natural dyes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.129-130
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• 2021

For the development of high-fluidity concrete using low-binder, The effect of the use of the developed acrylic viscosity agent on the physical properties of concrete evaluated. The amount acrylic viscosity agent used was 0.28%, 0.29% and 0.30% based on the binder amount of 350kg/m³, and slump flow test, air volume measurement, U-Box passing test and strength compressive were conducted to determine the effect of the physical properties of concrete. it was judged that 0.29% of the cellulose type viscosity agent used in high-fluidity concrete using low-binder was most suitable.

• Journal of The Korean Society of Grassland and Forage Science
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• 제36권4호
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• pp.344-349
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• 2016

This study was conducted to evaluate the possibility of expanding the usage of whole crop silage from beef cattle and dairy cow to hogs and chickens. For this purpose, a crushing device was developed to crush whole crop silage. The crushed silage was sealed, and analyzed for its feed value. The silage varieties used for the experiment included Saessal barley and Geumgang wheat. Whole crop barley and wheat were crushed in the crushing system as a whole without separating stems, leaves, grains, etc.. When the crushed whole crop silages (CWCS) were analyzed, full grain, grains above 10 mm in size, grains 5~10 mm in size, and grains below 5 mm in size accounted for, 20%, 4%, 27%, and 49 %, respectively. In order to facilitate the fermentation of CWCS, inoculated some fermenter into each CWCS sample (barley or wheat). As control, another set of sample was not inoculated. Crude protein (CP), ether extract (EE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, cellulose content, total digestible nutrient (TDN), and relative feed value (RFV) of fermenter-inoculated Saessal barley were 2.45 %, 1.61%, 8.95%, 16.94%, 9.52%, 1.01%, 8.51%, 81.38%, and 447.5%, respectively. The CP, EE, CF, NDF, ADF, lignin, cellulose content, TDN, and RFV in the other sample of Saessal barley without inoculation of fermenter were 2.57%, 1.62%, 9.61%, 18.25%, 10.13%, 1.10%, 9.04%, 80.90%, and 412.9%, respectively. The CP, EE, CF, NDF, ADF, lignin, cellulose content, TDN, and RFV of fermenter-inoculated Geumgang wheat sample were 2.43%, 1.27%, 10.99%, 19.49%, 11.23%, 1.46%, 9.77%, 80.03%, and 382.6%, respectively. The CP, EE, CF, NDF, ADF, lignin, cellulose content, TDN, RFV of the other set sample of Geumgang wheat sample without the inoculation of fermenter were 2.28%, 1.44%, 10.08%, 18.02%, 10.44%, 1.26%, 9.18%, 80.65%, and 416.9%, respectively. The TDN and RFV content in the fermenter-inoculated Saessal barley were 81.38% and 447.5%, respectively, while the one in the fermenter-inoculated Geumgang wheat were 80.03% and 382.6% respectively. When the feed value of whole crop barley and wheat silage without crushing process was compared to the feed value of whole crop barley and wheat silage made from crushing system, the latter appeared to be higher than the former. This could be due to the process of sealing the crushed silage which might have minimized air content between samples and shortened the golden period of fermentation. In conclusion, these results indicate that a crushing process might be needed to facilitate fermentation and improve the quality of silage when making whole crop silage.

• Korean Journal of Agricultural Science
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• 제36권1호
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• pp.1-10
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• 2009

The characteristics of fruit ripening and cell wall modifications of two oriental pear fruits were compared during storage. The loss of fresh weight was lower in 'Pingguoli' than 'Niitaka', probably due to the difference in wax accumulation and skin structure. 'Pingguoli' produced much higher amount of ethylene and showed climacteric ripening pattern, but this response was not found in 'Niitaka'. A significant difference in soluble pectin contents was found, thus, the amount of water soluble pectins were much higher in 'Niitaka' at harvest but this difference was not significant at later stage of storage. A severe loss of water soluble pectins in 'Niitaka' was confirmed whereas a similar tendency was not found in CDTA soluble ones. Even the amount of $Na_2CO_3$ soluble pectins was relatively low, 'Pingguoli' contained approximately 2 times higher than 'Niitaka' and both cultivars showed an increasing tendency in $Na_2CO_3$ soluble polymers at later stage of storage. No significant difference in alkali soluble polysaccharides (hemicelluloses fraction) was found between both cultivars. There was a significant change in gel filtration profiles regardless of cultivars, especially in water soluble pectins resulting from severe depolymerization probably due to degradation of higher molecular weight pectins and loss of their side chains. In gel filtration profiles of $Na_2CO_3$ soluble pectins, neutral sugars were evenly distributed regardless of molecular size of pectic polymers but the decrease of high molecular weight fraction was found. In comparison of alkali soluble polymers, a similar trend was found, that is, there was no difference in gel filtration profiles but 'Niitaka' seemed to have longer side chains in alkali soluble polysaccharides in both 4% and 24% of KOH soluble fractions.