방사선과 상호작용으로 단일 금 나노입자로부터 나타나는 2차 전자의 발생과 입자 크기, 입사 에너지 간 의 관계를 확인하였으며, 금 나노입자를 이용한 선량 증가 효과에 대한 기초 자료를 제공하고자 하였다. MCNPX MC code를 이용하여 Monte Carlo 시뮬레이션 기법을 적용하였으며, X선 에너지는 50, 100, 150 kV와 6, 15 MV를 사용하였다. 물 팬텀 내부에 30, 50, 70, 90, 110 nm 직경의 단일 금 나노입자를 위치 시켜 10 nm 간격으로 계수 체적을 지정하였다. 금 나노입자로부터 발생하는 전자의 차이는 입자가 없을 때를 기준으로 표준화하여 나타내었으며, X선의 에너지가 낮을수록, 금 입자의 직경이 클수록 많은 전자의 발생을 보였다. 에너지가 낮을수록 나노입자의 크기와 전자 발생 간 선형식에서 높은 기울기 값을 나타내 었으며, MV X선에 비해 kV X선에서 현저히 많은 전자의 발생을 보였다. 금 나노입자를 이용한 선량 증가 현상을 이해하기 위한 자료로 활용할 수 있을 것으로 생각되며, 추후 금 나노입자를 포함한 다양한 선량 증가 물질에 대한 추가 연구가 필요할 것으로 사료된다.

Structural performance of cable-bridge has been evaluated based on the field load test and the measurement monitoring system of existing Nielsen arch bridge. The measured acceleration data was converted to the displacement of girder and the tension of cable in the process of numerical integration and maximum frequency detection algorithm..

This study investigated the effect of electron beam (EB) treatment on the microbial reduction of dried laver (Porphyra tenera) and identified EB-resistant bacteria from the treated dried laver. After EB treatments of 4 kGy and 7 kGy, the numbers of total bacteria and EB-resistant bacteria were measured using tryptic soy agar and mannitol salt agar, respectively. The morphological and biochemical characteristics of each isolated EB-resistant bacteria were investigated and these bacteria were identified. Compared to the control (1.5±0.2)×106 CFU/g, the total bacterial number was significantly decreased to (5.4±0.5)×104 CFU/g and (1.1±0.6)×104 CFU/g after EB treatments of 4 kGy and 7 kGy, respectively. With a higher EB dosage, the number of red colonies was almost same, whereas the number of yellow colonies was significantly decreased to (3.3±1.2)×103 CFU/g and 0 CFU/g for 4 kGy and 7 kGy, respectively. All red and yellow colonies were gram-positive cocci, catalase-positive, and resistant to 3% and 5% NaCl media. From the 16S rDNA sequence analysis, yellow and red colonies were identified as either Micrococcus flavus or M. luteus, with 99% similarity for the yellow colonies, and Deinococcus proteolyticus and D. piscis, with 99% and 97% similarity for the red colonies, respectively.

Background : Plants belonging to 5 species of the genus Eleutherococcus are currently distributed in the Korean peninsula. The traditional medicine ‘Ogapi’, derived from Eleutherococcus sessiliflorus and other related species, and ‘Gasiogapi’, derived from Eleutherococcus senticosus, are frequently mixed up and marketed. Therefore, accurated identification of their origins in urgently required. Methods and Results : Candidate genes from nuclear ribosomal DNA (nrDNA) and chloroplast DNA (cpDNA) of Eleutherococcus plants were analyzed. Whereas the nrDNA-internal transcribed spacer (ITS) regions were useful in elucidating the phylogenetic relationships among the plants, the cpDNA regions were not as effective. Therefore, a combined analysis with nrDNA-ITS was performed. Various combinations of nrDNA and matK were effective for discriminating among the plants. However, the matK and rpoC1 combination was ineffective for discriminating among some species. Based on these results, it was found that OG1, OG4, OG5, OG7, GS1, GS2, and GS3 were derived from E. sessiliflorus. In particular, it was confirmed that GS1, GS2, and GS3 were not derived from E. senticosus. However, more samples need to be analyzed because identification of the origins of OG2, OG3, OG6 and GS4 was not possible. Conclusion : The ITS2, ITS5a, and matK combination was the most effective in identifying the phylogenetic relationship among Eleutherococcus plants and traditional medicines based on Eleutherococcus.

Currently in Korea, there are about 1200 dam (height 15m or more) Recently, natural disasters are caused by abnormal climate and they have caused a lot of damage. but many institutions about dam don’t resolve this problem because dam was owned and managed by other institutions. Therefore, to develop Web2.0 Smart Management System, it will be possible to combine different institutions and do efficiently intelligent management of dam.

The study was conducted for making accident-free, accurate and effective construction site to improve the smart construction site management system by using new developed technology such as IoT, RFID, and etc... The study recommends new IoT construction management application and web with a structure of the system

This study provides an experimental result of thermal mercury reduction and condensation characteristics for inventing a mercury recovery technology from the waste sludge which contains high concentration of mercury. Thermal treatment was conducted in the temperature range of up to 900oC from 600oC with different residence time using a waste sludge from domestic industrial facility. Properties of powder material condensed after thermal treatment were analyzed to assess the effectiveness of thermal processing. Leaching characteristics of bottom ash and condensed powder material were analyzed by Korean Standard Leaching Test method (KSLT). Cold vapor atomic absorption spectroscopy (CVAAS) Hg analyzer was used for the analysis of mercury content in solid and liquid samples. We found that mercury contents was concentrated compared with waste sludge. However, the mercury concentration of leached solution from the condensed powder material was very low. The chemical characteristics of condensed powder material was estimated using experimental analysis and literature survey. In order to recover purified elemental mercury, the further researches of refining experiments would be required.

We conducted this study to develope technique for removing fine mortar attached to waste reinforcing steel bar (D13). We observed the effect of the glycolic acid concentration (10 ~ 40%) and reaction time (0.5 ~ 4 hr) on the mortar removal. The reaction rate (−1.3089 hr−1) was the fastest at 20% of glycolic acid. The mortar was completely removed in 3 hrs. The reaction rate decreased with pH increase (1.4 ~ 2.0) at 20% of glycolic acid.

레고(Lego)식 차도블록 시스템은 도심지 도로굴착 공사 후 원상 복구공사 및 가설 도로 현장에서 안전하고 신속하게 임시 도로 포장면을 형성하는 것으로써 지금까지 없었던 선진국형의 획기적 공사 방법으로 교통체증, 교통사고, 비산먼지, 폐기물, 민원의 발생을 억제할 수 있다. 그리고 기술적으로는 다짐 불량으로 인한 부실공사를 방지하며, 재시공에 따른 공사비 과다 투입을 방지할 수 있는 경제적으로 예산 절감을, 사회적으로 국민의 안전과 건강을 지킬 수 있는 신개념·신기술의 친환경 건설을 제공하는 도로포장 복구용 블록 시스템이다. 레고식 차도블록 시스템의 주요 기능은 가설 포장도로 형성 및 자동 다짐, 비산먼지 덮개 기능, 견고한 상하·좌우 결합 및 결속 기능 그리고 과속방지, 야간 식별장치, 선형 변경 기능 등을 가지고 있다. 특히, 개발된 레고식 차도블록 시스템의 자동 다짐 기능은 블록 하부에 일정한 돌기형 몰드가 바닥판을 구성한 후 블록 상단으로 통행하는 차량의 윤하중에 의한 진동에너지를 이용하여 보조기층이 자동 다짐됨에 따라 단단하고 균등한 몰드가 형성되어 다짐 불량에 의한 부실시공이 자연적으로 제거될 뿐만 아니라 본 포장시 완벽한 포장을 가능케 한다. 본 연구에서는 선진국형 도로복구를 위해 개발된 레고식 차도블록 시스템의 다짐 성능에 대한 검증을 위해 실내 및 현장 시험을 수행하였으며, 레고식 차도블록이 하부지반의 다짐 및 강성에 미치는 영향을 검토하였다.

현재 복잡한 도심지 도로 복구공사에서는 당일 굴착 및 복구로 인한 조급한 시공으로 다짐이 완벽하지 않아 부실시공의 발생 위험이 존재하며, 일일 복구공사 투입대비 복구수량 감소로 인해 시공적자가 증가하고 있다. 특히, 공사 주변 비산먼지로 인한 민원이 급증하고 있어 이에 대한 대책이 시급한 상황이다. 이러한 현 문제점들을 해결하기 위한 대책으로 세계 최초로 복잡한 도심지 도로 복구공사에서의 교통 혼잡 및 정체, 비산먼지의 발생을 방지하고, 부실공사를 예방하여 경제적 효과를 획기적으로 창출하는 선진국형 기술개발의 일환으로써 신개념·신기술의 도로복구를 위한 레고(Lego)식 차도블록 시스템을 개발하였다. 본 연구에서는 선진국형 도로복구를 위해 개발된 레고식 차도블록 시스템의 개념 및 기능에 대해 정립하고, 차량 윤하중에 의한 동적 유한요소해석을 통해 차도블록 시스템의 동적 거동 검토를 수행하였다. 또한, 레고식 차도블록 시스템의 동적 해석결과를 활용하여 최대 연직변위로 인해 발생한 지반의 다짐 효과와 최대 상향 변위 발생으로 인한 동적 구조 안전성에 대해 평가하였다. 본 레고식 차도블록 시스템은 세계 최초로 개발한 도로 굴착복구 방법의 신개념·신기술의 선진국형 건설 시스템으로 상·하수도, 전기, 통신 등 긴급도로 복구공사와 관로 굴착공사, 임시 우회도로, 가설도로 그리고 임시 및 상설 주차장 등 다양하게 사용됨에 따라 국민과 국가와 기업이 상생하고, 저탄소 녹색성장을 주도하는 미래의 친(건설)환경을 제공할 것으로 전망된다.

Polygonatum is a genus placed in the family Liliaceae, distributed throughout the Northern Hemisphere and 16 of the species are grown naturally in Korea. In oriental medicine, the rhizomes of Polygonatum have been used as two different medicines, Okjuk (Polygonati odorati Rhizoma) and Hwangjeong (Polygonati Rhizoma). However, it is difficult to identify the morphological and chemical differences between the medicinal groups and thus easy to confuse the one with the other. Therefore, a clear classification standard needs to be established so as to be able to discriminate between them. In the study, the morphological characteristics of the plants, Polygonatum spp., were examined. Then, the differences in SNPs among the DNA sequences of 7 of the Polygonatum spp. and 1 of the Disporum spp. were analyzed by DNA barcoding with rpoC1, rpoB2, matK, and psbA-trnH of the cpDNA region. In the results, three regions, rpoC1, rpoB2, and matK were useful for discriminating the species, P. stenophyllum and P. sibiricum. Furthermore, it was possible to discriminate the individual germplasm within the species by using the combination of the results obtained from rpoB2, rpoC1, and matK.

Fossil fuel combustion generates large amount of green house gas and it was considered major emission source causingglobal warming. For reducing green house gas, renewable energy resources have been emerged as an alternative energy.Among those resources, waste has been considered major resource as one of renewable energy, but it has been not utilizedsufficiently. In Korea, there are lots of efforts to utilize sewage sludge as one of renewable energy resources due to wasteto energy project of government. In this paper, sewage sludge was utilized as main fuel in order to recover heat energysource using oxy-fuel combustion in 30KWth circulating fluidized bed (CFB) pilot plant. Firstly, basic characteristics ofsewage sludge were analyzed and fuel feed rate was calculated by stoichiometry oxygen demand. For producing 30kwthermal energy in pilot plant, the feeding rate of sewage sludge was calculated as 13kg/hr. In oxy-fuel combustion, oxygeninjection rate was ranged from 21% to 40%. Fluidized material was more suitably circulated in which the rate of U/Umfwas calculated as 8 at 800oC. Secondly, Temperature and pressure gradients in circulation fluidized bed were comparedin case of oxy and air combustion. Temperature gradients was more uniformly depicted in case of 25% oxygen injectionwhen the value of excess oxygen was injected as 1.37. Combustion efficiency was greatest at the condition of 25% oxygeninjection rate. Also, the flue gas temperature was the highest at the condition of 25% oxygen injection rate. Lastly,combustion efficiency was presented in case of oxy and air combustion. Combustion efficiency was increased to 99.39%in case of 25% oxygen injection rate. In flue-gas composition from oxy-fuel combustion, nitrogen oxide was ranged from47ppm to 73ppm, and sulfur dioxide was ranged from 460ppm to 645ppm.

의료용 선형가속장치는 1952년에 개발된 이후 방사선 치료에 사용되어 왔으며 그 활용도가 더욱 증가하고 있다. 현재는 6 MeV 이상의 광자 에너지를 사용하는 고 에너지 방사선치료가 보편화되어 사용되고 있으나, 광핵반응에 의한 중성자의 생성으로 환자 및 술자에 대한 피폭이 문제가 되고 있다. 이에 본 연구에서는 MCNPX를 사용하여 의료용 선형가속장치에서 발생되는 6~24 MV 광자선의 스펙트럼을 분석하고, 평균에너지 및 텅스텐의 중성자 생성 임계에너지인 7.41 MeV 이상의 광자 개수를 평가하였다. 그 결과 8 MV를 시작으로 24 MV에서는 전체 검출 광자 수에 비해 0.59%의 비율로서 광핵 반응을 일으킬 수 있는 광자수가 증가함을 알 수 있었다.

This study provides a result of thermal mercury reduction for inventing a mercury recovery technology from the sludgewhich contains high concentration of mercury. Physical, chemical and thermal properties of the sludge were analyzed andmercury degradation at elevated temperatures was investigated to find out the optimum temperature range for thermalrecovery of mercury from the sludge generated from an industrial facility, which contained high concentration of mercury.The study was carried out in the temperature range of up to 650oC from 200oC, and 500~710µm particle size of wastesludge samples were selected from such industries. As primary thermal tests the sludge was heated up to observe weightdegradation at a continuous weight measurable thermogravimetric analyzer and a muffle furnace and the degradationcurves from both devices were found to be well matched. Mercury conversion to gaseous form was investigated fromthe analyzed data of mercury concentrations sampled every 25oC from a muffle furnace. Cold vapor atomic absorptionspectroscopy (CVAAS) Hg analyzer was used for the analysis of mercury content in solid and liquid samples. Most ofmercury was degraded and released as gas phase at the temperature range from 300oC to 550oC, which could be theoptimum temperature of mercury recovery by thermal method for the sludge containing high concentration of mercury.Based on these thermal mercury reduction studies, degradation kinetics study of mercury was conducted to provide thereaction kinetics data for further reactor design to recover mercury using a thermal method.