• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.61-65
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• 2011

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce the large amount of energy from biomass around the world. In this study, to obtain basic data for practical application of agricultural and forest by-products as fuel of heating system in agriculture, agricultural and forest biomass resources were surveyed, the pelletizer with capacity of $50\;kg{\cdot}h^{-1}$ was designed and manufactured and pellets were made by the pelletizer. High heating value, ash content, etc. of pellets made of agricultural and forest by-products were estimated. Straw of rice was the largest agricultural biomass in 2009 and the total amount of rice straw converted into energy of $299{\times}10^3$ TOE. And in 2009, amount of forest by-product converted into energy of $9,579{\times}10^3$ TOE. High heating values of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk were 16,034, 16,026, 16,089, 15,650, $15,044\;kJ{\cdot}kg^{-1}$ respectively. High heating values of pellets made of agricultural by-products were average 83.6% compared to that of wood pellet. Average bulk density of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk was $1,400\;kg{\cdot}m^{-3}$ ($1.4\;g{\cdot}cm^{-3}$). Ash contents of the pellets were 6.6, 7, 6.2, 5.5, 33% respectively. Rice husk pellet produced the largest ash content compared to other kinds of pellets.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.72.1-72.1
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• 2013

광촉매 활용 기술은 수질 및 대기 중의 난분해성 오염 물질 처리 등의 환경 분야에서부터 항균 및 초친수성 기능을 활용한 소재 분야, 그리고 태양광을 이용한 물분해 수소 제조 및 이산화탄소의 전환 등의 인공 광합성 연구 분야까지 그 응용분야가 대단히 넓은 기술이다. 본 강연에서는 이러한 광촉매의 반응 원리와 대표적인 응용분야인 환경 정화 분야 및 에너지 분야에서의 광촉매 기술의 활용, 그리고 현재 광촉매 관련 연구 분야의 주요 관심사 및 미래 성장을 위한 과제 등을 포괄적으로 다루고자 한다. 광촉매 반응은 반도체의 따간격 에너지 흡수에 따라 전자와 정공(+전하를 가진 전자와 같은 거동을 하는 입자)가 발생한 뒤에 일어나는 계면에서의 전자전달 반응을 기초한다. 발생한 정공과 전자는 각각 산화와 환원 반응을 유발하며 이러한 산화, 환원반응을 통해 다양한 분야로의 응용이 가능하다. 환경 정화 분야의 경우, 정공이 물 혹은 공기 속에 존재하는 수분과 반응하여 생성되는 OH 라디칼 ($OH{\cdot}$)의 강력한 산화력을 주로 이용하게 된다. OH 라디칼에 의한 다양한 난분해성 유기물질의 산화분해 반응을 활용하여 고도처리공정이 가능하게 되며, 수계 난분해성 유기오염물질의 제거뿐만 아니라 대기 중에 존재하는 VOCs, 악취물질 등의 분해도 가능하며, 아울러 바이러스나 박테리아와 같은 세균을 제거할 수 있는 것으로 알려져 있다. 한편, 물 분해 수소제조 및 이산화탄소의 전환과 같은 에너지 분야 응용의 경우, 전도대의 전자를 활용한 환원반응에 기초한다. 앞서 언급한 다양한 응용분야에서 활용될 수 있는 광촉매의 종류 또한 매우 다양하며, 이사화티탄(TiO2)는 대표적인 고효율 상용 광촉매이다. 아울러, 원하는 응용 분야에서의 광활성이 높은 새로운 광촉매의 제조 및 평가가 꾸준히 진행되고 있으며, 그 가운데 태양광의 가장 많은 영역을 차지하고 있는 가시광 활성을 갖는 광촉매 개발에 관한 연구가 활발히 수행되고 있다. 이에, 현재까지 개발된 다양한 가시광 광촉매 시스템에 대한 소개 및 각 광촉매 응용분야에서 최근 새롭게 대두되고 있는 이슈들에 대하여 중점적으로 고찰하고자 한다.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.136-144
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• 2004

In this paper, we present an improved channel estimation method for orthogonal frequency division multiplexing systems using pilot-symbol-aided parameter estimation. Conventional linear minimum mean square error(LMMSE) channel estimation method uses only pilot symbols for channel estimation. So, as the fading channel varies rapidly, a performance is decreased. We proposed a channel estimation method, which estimates channel attenuation in the middle of pilots using pilot symbols and then estimates the whole channel attenuation with pilots and estimated channel attenuation. Compared with conventional LMMSE channel estimation method, the proposed method is significantly robust in a rapid fading channel with high Doppler frequency and delay spread.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.128-142
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• 2021

Purpose: This study examines the safety management of anchors that have already been constructed and evaluates the results of lift-off tests conducted at the site. The purpose of the project is to study countermeasures if necessary. Method: Compare the residual load gained after the lift-off test at 36 points behind the site with the preemptive load, allowable load, and design load. We also analyze stability through this and evaluate the stability of anchors. Results and Conclusion: The residual tension at 26 points remained stable. However, the residual load at 10 points was analyzed to be greater than the designed load and less than the allowable load, and it was evaluated as an instability that could cause fracture problems. Therefore, anchors with unstable conditions at 10 points should be monitored and monitored through periodic measurements and quality tests, and the anchor should be observed at the surrounding points as well as the relevant points to maintain stability.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.106-114
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• 2021

We evaluated the anti-cancer activity against human prostate cancer cells and the associated molecular mechanism of extracts from the branches of Rhamnus yoshinoi (RYB). Treatment with RYB suppressed viability of human prostate cancer cells (PC-3) and decreased protein levels of both β-catenin and T-cell factor 4 (TCF4). This was reflected in reduced TCF4 mRNA, but not decreased β-catenin mRNA. PC-3 cells were pretreated with the proteosome inhibitor MG132 before treatment with RYB, which blocked RYB-mediated down regulation of β-catenin in PC-3 cells, thus confirming that RYB promotes the proteasomal degradation of β-catenin. RYB induced β-catenin phosphorylation, and GSK-3β inhibition by LiCl blocked the phosphorylation and proteasomal degradation of β-catenin by RYB. These results suggest that GSK-3β may be an important upstream kinase for RYB-mediated regulation of β-catenin. Finally, GC/MS analysis of RYB identified 18 compounds. Based on these findings, RYB shows potential for development as a therapeutic agent for prostate cancer.

• Journal of the Korean Geotechnical Society
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• v.28 no.5
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• pp.13-25
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• 2012

Ground anchor method is one of the most popular reinforcing technology for slope in Korea. For the health monitoring of slope which is reinforced by permanent anchor for a long period, monitoring of the tension force of ground anchor is very important. However, since electromechanical sensors such as strain gauge and V/W type load cell are also subject to long-term risk as well as suffering from noise during long distance transmission and immunity to electromagnetic interference (EMI), optical FBG sensors embedded tendon was developed to measure strain of 7-wire strand by embedding FBG sensor into the center king cable of 7-wire strand. This FBG sensors embedded tendon has been successfully applied to measuring the short-term anchor force. But to adopt this tendon to long-term monitoring, temperature compensation of the FBG sensors embedded tendon should be done. In this paper, we described how to compensate the effect in compliance with the change of underground temperature during long-term tension force monitoring of ground anchors by using optical fiber sensors (FBG: Fiber Bragg Grating). The model test was carried out to determine the temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon. The determined temperature sensitivity coefficient ${\beta}^{\prime}=2.0{\times}10^{-5}/^{\circ}C$ was verified by comparing the ground temperatures predicted from the proposed sensor using ${\beta}^{\prime}$ with ground temperatures measured from ground thermometer. Finally, temperature compensations were carried out based on ${\beta}^{\prime}$ value and ground temperature measurement from KMA for the tension force monitoring results of tension type and compression type anchors, which had been installed more than 1 year before at the test site. Temperature compensated tension forces are compared with those measured from conventional load cell during the same measuring time. Test results show that determined temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon is valid and proposed temperature compensation method is also appropriate from the fact that the temperature compensated tension forces are not dependent on the change of ground temperature and are consistent with the tension forces measured from the conventional load cell.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.3 s.151
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• pp.481-486
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• 2006

There are attempts to utilize Hanji for apparel material, but, the reason that the strength and durability of Hanji decrease to a great extent in the wet condition, restricts the usability of Hanji. In order to improve the resistance against water, Hanji was treated with silicone type water repellent agents. The treatment was carried out by conventional pad-dry-cure method. The optimum treatment condition was obtained by varying the concentration of repellent agent, curing temperature and time. Water repellency was tested by spray rating method. Wet and dry tensile strength, tearing resistance and abrasion resistance were examined after the treatment. Flexural stiffness and wrinkle recovery angles of hanji were also measured. In result, the optimum condition of treatment was at resin concentration of 40g/l, catalyst concentration of 20g/l(half of resin concentration), curing temperature of 160$^{circ}C$, curing time of 120 sec. Flexural stiffness of Hanji was hardly increased and wrinkle recovery angle of Hanji was improved a little by resin treatment. After the treatment, in dry condition, tensile strength and tearing resistance were little changed but abrasion resistance was improved. In wet condition, tensile strength, tearing strength and abrasion resistance were improved.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.27-36
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• 2010

Objectives : We investigated the role of intracellular calcium chelator, bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid(BAPTA), on the modulation of phosphorylation of the spinal N-methyl-D-aspartate receptor(NMDAR) NR1 and NR2B subunits following electroacupuncture(EA). Methods : Bilateral 2 Hz EA stimulation with 1.0 mA was delivered at those acupoints corresponding to Zusanli(ST36) and Sanyinjiao(SP6) in man via needles for 30min. Results : EA analgesia was reduced by intra-peritoneal injection at a higher dose of BAPTA from termination of EA stimulation. At 60 min after EA treatment, the total number of c-fos-immunostained neurons in each regions of the dorsal horn in the $L_{4-5}$ segments was decreased by BAPTA injection, especially in nucleus proprius. The mean integrated optical density (IOD) of NR1 and NR2B subunits were increased only in superficial laminae of EA-treated rats when compared with normal rats. However, the mean IOD of pNR1 was significantly decreased by BAPTA injection in both the superficial laminae and neck region and pNR2B in the superficial laminae. Western blot analyses confirmed the decreased expression of pNR1 and pNR2B. Conclusions : We concluded that intracellular calcium may well play an important role in EA analgesia by modulating the phosphorylation state of spinal NMDAR subunits.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.252.2-252.2
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• 2010

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce the large amount of energy from biomass around the world. In this study, to obtain basic data for practical application of wood pellet and wood pellet boiler system as heating system in agriculture, agricultural biomass resources were surveyed, pellet was made of agricultural by-product such as stem of rape, oat and rice, ricehusk and sawdust and wood pellet boiler system with capacity of 116 kW was manufactured and installed in greenhouse of $38.5m{\times}32m$. High heating value, bulk density and ash content of pellet made of agricultural by-product and efficiency and heating performance of this system was estimated. Rice straw was the largest agricultural biomass in 2005 and the total amount of rice straw converted into energy of $131.71{\times}10^{11}$ kJ. And in 2005, total amount of forest' by-product converted into energy of $29,277.05{\times}10^{11}$ kJ. High heating values of pellets made of agricultural by-products of stem and seed of rape, stem of oat, rice straw and rice husk were 16,034, 16,026, 16,089, 15,650, 15,044 kJ/kg respectively. High heating values of pellets made of agricultural by-products were 83.6% compared to that of wood pellet. Average bulk density of pellets made of agricultural by-products of stem and seed of rape, stem of oat, rice straw and rice husk was 1,400 $kg/m^3$. Ash contents of the pellets were 6.6, 7.0, 6.2, 5.5, 33% respectively. Ash content of rice husk pellet was the largest compared to other kind of pellets. To increase efficiency of agricultural pellet boiler, the boiler adopted secondary heat exchanger. The agricultural pellet boiler designed and manufactured in this study had high efficiency of 84.2% compared to the conventional agricultural pellet boiler, when water flow rate, exhaust gas temperature and average combustion furnace temperature were 39L/min, $180^{\circ}C$, $680^{\circ}C$ respectively. And pellet supplying and pausing time were 13, 43 seconds respectively. In March of 2010, prices of wood pellet, agricultural tax free diesel, diesel, kerosene were 350 won/kg, 811 won/L, 1,422 won/L, 976 Won/L respectively. Also in terms of energy, prices per same heating value were 77.8, 90.1, 158, 108.4 Won/Mcal. Energy saving rate of wood pellet was 16, 50, 39% compared to agricultural tax free diesel, diesel and kerosene respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.44-52
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• 2012

As an alternative strategy in the era of high level petroleum cost, the study focused to suggest the way on the revitalization of renewable energy through the impact on introduction effect of renewable energy in green village. Total feasible solar energy production is 6.73 GWh/yr along with the biomass energy producing electric power energy is 134.06 GWh/yr, the two category's total electric power energy is 233.19 GWh/yr, which is possible to achieve the selfsufficiency of energy by 33% for total energy consumption of 705.80 GWh/yr in the region. The calculated feasibility on the carbon dioxide reduction, carbon dioxide reduction level is 1,891 ton_$CO_2$ by agricultural byproducts, 43,635 ton_$CO_2$ by livestock waste, 395 ton_$CO_2$ by municipal waste, 50,324 ton_$CO_2$ by forest byproducts, the total biomass shows 96,245 ton_$CO_2$, while the carbon dioxide reduction of solar light energy is 2,251 ton_$CO_2$, 1,383.3 ton_$CO_2$ by solar heat energy, the total solar energy shows 3,634 ton_$CO_2$. So total carbon dioxide reduction effect shows 99,879 ton_$CO_2$.