• International Journal of Reliability and Applications
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• 제10권2호
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• pp.89-99
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• 2009

Oriented Strand Board (OSB) is an important engineered wood product used in housing construction which has a lower environmental impact or "carbon footprint." In this paper, reliability and statistical tools are applied to gain insights on the strand thickness of OSB panels. An OSB panel consists of several hundred wood strands that are resinated and pressed. The variability of OSB strand thickness for six manufacturers in the Eastern United States is examined as a whole, as well as individually. Little research exists on OSB strand thickness across mills even though strand thickness variability has been documented in laboratory experiments to greatly influence the dimensional stability of OSB panels. Our aims are to quantify and characterize strand thickness, plus apply reliability techniques, such as Kaplan-Meier curves, to characterize the probability of strand thickness. We further explore graphically and statistically the thickness of the strands.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.47-56
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• 2015

본 논문에서는 HDI(High Density Interconnection) 기판의 코어로 사용될 수 있는 카본 CCL(Copper Claded Layer)의 열거동 및 신뢰성 특성을 실험과 CAE를 이용한 수치해석을 통해 평가하였다. 카본 CCL의 특성평가를 위해 기존 FR-4 코어와 heavy cu 코어와 비교하였다. 연구결과에 의하면 pitch계열 카본코어가 적용된 PCB의 휨강도가 가장 높고 온도에 따른 변형량이 가장 낮았다. 또한, HDI 신뢰성평가 기준의 TC(Thermal Cycling), LLTS(Liquid-to-Liquid Thermal Shock), Humidity 실험을 통해 카본코어가 적용된 PCB는 신뢰성이 확보되었음을 확인하였다. 카본 파이버에 의한 불균일한 비아홀의 표면형상 여부와 드릴비트 마모 가능성을 분석하였는데 비아홀의 표면은 균일하고, 드릴비트의 표면도 매끄러워 카본 CCL의 우수한 드릴가공성도 확인하였다.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.19-27
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• 2017

This paper is a study to improve the fire-resistance capacity of reinforced concrete (RC) members strengthened by fiber-reinforced-polymer (FRP). The fire resistance of the RC members strengthened by FRP was evaluated through high temperature exposure test. In order to improve the fire resistance of the FRP reinforcing method, a fire-proof board was attached to the reinforced FRP surface and then the high temperature exposure test was carried out to evaluate the improvement of the fire resistance performance. It was confirmed that the resistance to high temperature of NSMR could be improved somewhat compared with that of EBR from the experiment that exposed to high temperature under the load corresponding to 40% of nominal strength. When 30 mm thick fire-resistance (FR) board is attached to the FRP surface, the surface of the reinforced FRP does not reach $65^{\circ}C$, which is the glass transition temperature (GTT) of the epoxy until the external temperature reaches $480^{\circ}C$. In particular, when a high performance fire-proof mortar was first applied prior to FR board attachment, the FRP portion did not reach the epoxy glass transition temperature until the external temperature reached $600^{\circ}C$.

• Journal of Biosystems Engineering
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• 제23권2호
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• pp.187-194
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• 1998

This study was carried out to investigate mechanical properties o major part for agricultural machinery in Korea. The results are as follows ; 1. The mechanical Properties for heat resisting steel bars, alumium alloy castings, carbon steel for machine structural use, chromium molybdenum steels, high strength brass castings and carbon tool steels are proper for Korean standard. 2. The mechanical properties fir spring steels used to mould board, share of plow and blade of rotary are not suitable to Korean standard. Ⅰ think that a counterplan for quality rising is necessary such as supply of good quality materials and improvement of new materials in Korean agricultural machinery.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.37-46
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• 2015

본 논문에서는 PCB용 카본 CCL의 열전달 특성을 실험과 수치해석을 통해 연구하였는데 카본 CCL의 특성 연구를 위해 기존 FR-4 코어와 Heavy copper 코어를 적용한 PCB를 비교하였다. 열전달특성 분석을 위해 코어는 한 개와 두 개가 적용된 HDI PCB 샘플이 제작되었고, 카본코어는 Pan grade와 pitch grade의 2종이 적용되었으며, 코어 두께에 의한 열전달 특성도 평가되었다. 연구결과에 의하면 카본 코어의 열전달 특성은 heavy copper 코어보다는 낮으나 FR-4 코어보다는 우수하였다. 또한, 카본 코어와 heavy copper 코어는 두께가 증가할수록 열전달 특성이 높아졌으나 FR-4 코어는 두께가 증가할수록 열전달 특성이 낮아졌다. heavy copper 코어 적용시 드릴마모도 증가, 무게 증가, 전기절연성 확보를 위한 절연재의 추가로 원가상승을 고려할 때 카본 코어가 PCB의 열전달 특성 향상을 위한 대안이 될 것으로 판단된다.

• 한국유기농업학회지
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• 제20권4호
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• pp.475-490
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• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic, fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.04968kg-$CO_2$ for oystershells, 0.004692kg-$CO_2$ for expanded rice hull, and 1.029kg-$CO_2$ for bordeaux mixture liquid.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.340-340
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• 2017

Rice straw is very important to maintain fertility in agricultural soil with several aspects such as carbon and nitrogen cycles in Korea. Recently, concerning about climate change, carbon sequestration in agricultural land has become one of the most interesting and debating issues. Rice straw is most representative source of organic material produced in agricultural sectors. In order to evaluate changes of soil carbon treated by rice straw during cultivating rice in paddy field, we carried out to treat rice straw with 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ at $50{\times}50{\times}20cm$ blocks made of wood board, and analyze contents of fulvic acid and humic acid form, and total carbon periodically. The experiment was conducted in 2013-2016, and sampled with interval in a month. The organic material was applied to treatment blocks in 2 weeks ago in rice transplanting of each year. Total carbon in beginning time is low as $7.9g\;kg^{-1}$. The contents of total carbon with treatments of rice straw after experiment are recorded as 8.7, 11.2, 9.5, 10.5, and $10.9g\;kg^{-1}$ applied by 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$, respectively. When trend lines were calculated on changes of soil carbon in periods of experiments, The trend equations of soil carbon changes with treatments of 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ were Y=0.0015X+8.479, Y=0.073X+8.2577, Y=0.0503X+8.4477, Y=0.0822X+8.2103, and Y=0.082X+8.5736. These trends suggested several results. When rice straw was applied in cultivating paddy fields, most carbon in rice straw would be decomposed regardless the amount of rice straw in soil. We calculated sequestration rate of applied rice straw as about 0.1% per year during rice cultivation in paddy fields. It means that if farmer want to increase 1% soil organic matter by using application of rice straw returned after cultivation, famer should apply rice straw continuously for ten years. The change of soil carbon as fulvic acid, humic acid, and humane is showed that only content of carbon as mumine is increased significantly while fulvic acid and humic acid were changed in range of 10 to 30% among total carbon in soil. In conclusion, to sequestrate soil carbon with rice straw, it is important for rice straw to apply continuously every year. The amount of rice straw applied is not much effected to increase soil organic matter.

• 한국토양비료학회지
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• 제48권6호
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• pp.736-743
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• 2015

Organic matter plays important roles in soil ecosystem in terms of carbon and nitrogen cycles. Due to recent concerns on climate change, carbon sequestration in agricultural land has become one of the most interesting and debating issues. It is necessary to understand behavior of soil carbon for evaluating decomposition or sequestration of organic matter and analyzing potential carbon decomposition pattern about the kinds of organic matter sources to cope with well. In order to evaluate decomposition of soil carbon according to organic material during cultivating rice in paddy field, we treated organic material such as hairy vetch, rice straw, oil cake fertilizer, and manure compost at $50{\times}50{\times}20cm$ blocks made of wood board, and analyzed carbon contents of fulvic acid and humic acid fraction, and total carbon periodically in 2013 and 2014. Soil sampling was conducted on monthly basis. Four Kinds of organic matter were mixed with soil in treatment plots on 2 weeks before transplanting of rice. The treatment of animal compost showed the highest changes of total carbon, which showed $7.9gkg^{-1}$ in May 2013 to $11.6gkg^{-1}$ in October 2014. Fulvic acid fraction which is considered to easily decompose ranged from 1 to $2gkg^{-1}$. Humic acid fraction was changed between 1 to $3gkg^{-1}$ in all treatments until organic material had been applied in 2014. From May to August in the second year, the contents of humic acid fraction increased to about $4gkg^{-1}$. The average of humic fraction carbon at treatments of animal compost was recorded highest among treatments during two years, $2.1gkg^{-1}$. The treatment of animal compost has showed the lowest ratio of fulvic acid fraction, humic acid fraction compared with other treatments. The average ratio of fulvic fraction carbon in soil ranged from 16 to 20%, and humic fraction carbon ranged from 19 to 22%. In conclusion, animal compost including wood as bulking agent is superior in sequestrating carbon at agricultural land to other kinds of raw plant residue.

• 멤브레인
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• 제20권4호
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• pp.267-277
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• 2010

가스분리막을 이용한 분리공정은 기존의 분리공정을 대체할 공정으로서 수십 년간 발전이 되어 왔다. 특히 분리막 공정은 가스분리에 있어서 기존공정에 비해서 에너지 소모가 적고 설치에 필요한 공간이 간소하며, 스케일업이 간단한 장점이 있다. 최근에는 기체분리막 공정은 질소발생장치, 수소발생장치, 막제습기, 선박이나 항공기용 불활성기체충진장치, 천연가스 정제, 바이오가스 정제, 연료전지분야에서 널리 사용이 되고 있으며, 향후에는 이산화탄소의 분리에도 강력한 대체공정으로 사용이 될 수 있다. 이러한 가스분리막 공정을 좀 더 널리 보급하기 위해서는 로베슨 플롯의 한계를 넘어설 수 있는 새로운 소재의 개발이 절실하며, 이러한 한계를 돌파하기 위하여 많은 연구자와 회사들이 카도그룹이나 스피로 구조를 가지는 고분자나 PIMs 같은 소재의 개발에 박차를 가하고 있다.

• 공업화학
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• 제20권6호
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• pp.622-627
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• 2009

알칼리 수용액에 현상이 가능한 감광성 수지재료와 전도성 카본블랙 필러를 이용하여 포토 패터닝이 가능한 폴리머 후막 저항 페이스트를 제조하고 평가하였다. 감광성 수지로는 인쇄회로기판의 보호층으로 주로 사용되는 photo solder resist(PSR)를 사용하여 자외선에 의한 노광 및 알칼리 수용액에의 현상이 가능하게 하였다. 감광성 폴리머 저항 페이스트를 제작한 후, PCB 테스트 보드를 이용하여 후막저항체의 전기적 특성을 평가하였다. 카본블랙의 첨가량에 따라 시트저항은 감소하였으나, 과량 첨가시에는 현상성에 한계를 나타내었다. 재경화에 따라서 시트저항이 감소하였으며, 카본블랙의 첨가량이 많을수록 그 변화율은 작게 나타났다. 포토공정을 적용하여, 미세 패터닝된 meander형 후막저항체를 제조할 수 있었고, 이 방법을 통하여 적은 면적에도 시트저항의 수십 배에 달하는 큰 저항값을 구현할 수 있었다.