고준위방사성폐기물의 처분터널 및 처분공 간격을 결정하고 처분시스템의 성능을 평가하기 위해서는 열-수리-역학적인 복합 거동 변화에 대한 이해가 반드시 필요하고 이를 반영하여 해석해야만 한다. 하지만 한국형 기준 처분시스템에서의 처분 터널 및 처분공 간격을 결정하기 위해 수행된 기존의 연구들은 이러한 복합거동 특성을 반영하지 않고 열 해석 결과만을 근거로 처분시스템을 설계하였다. 따라서 본 연구에서는 열-수리-역학적인 복합거동 특성을 반영하여 한국형 기준 처분시스템의 성능을 TOUGH2-MP/FLAC3D를 이용하여 평가하였다. 고준위방사성폐기물이 처분된 이후 방사성 붕괴열에 의해 처분 시스템의 온도는 급격히 증가하다가 붕괴열의 감소로 온도는 서서히 감소하였으며, 해석 기간 1,000년 동안 벤토나이트 완충재의 최고 온도는 설계 기준인 100℃ 이하로 유지되는 것으로 나타났다. 처분용기와 벤토나이트 완충재의 계면에서의 최고 온도는 약 3.21년이 지난 시점에 용기의 중간 지점에서 약 96.2℃로 나타났으며, 암반에서의 최고 온도는 폐쇄 후 약 17년 이 지난 시점에서 약 68.2℃로 계산되었다. 처분용기 부근 벤토나이트 완충재는 처분 초기에 온도 변화에 따른 건조현상이 발생하여 포화도가 감소하지만, 시간이 지남에 따라 주변 암반으로부터의 지하수 유입에 의해 포화도가 증가하는 것으로 계 산되었다. 이후, 벤토나이트 완충재 및 뒷채움재 모두 약 266년 이후 완전히 포화되는 것으로 계산되었다. 처분시스템에서의 온도 변화에 따른 열응력 그리고 벤토나이트 완충재 및 뒷채움재의 팽윤압으로 인한 응력 변화가 처분장 주변 암반에 미치는 영향을 평가하고자 수치해석에서 계산된 응력을 스폴링 강도(spalling strength)와 Mohr-coulomb 파괴 기준식과 비교 하였다. 계산 결과 일축압축강도와 스폴링 강도에 도달하지 않는 것으로 나타나 처분시스템이 스폴링에 의한 파괴는 나타나지 않을 것으로 판단되며, Mohr-coulomb 파괴 기준 역시 충족하는 것으로 나타났다. 본 연구에서 사용된 수치해석 코드와 방법론은 다양한 조건에서의 한국형 기준 처분시스템에 대한 성능평가뿐만 아니라, 복층 처분시스템에 대한 설계와 성능평가에 활용될 수 있을 것으로 판단된다.
Thermal power generation was a very important power source in Korea. Therefore improvement of seismic reliability of the thermal power plants is required, because occurrence of very large earthquakes is expected in Korea. Especially, after the earthquake in Gyeong-ju and Po-hang, seismic waves are recognized as a new problem in Korea. In this study, numerical analysis was carried out in order to investigate behavior of the boiler structure in the thermal power plant under earthquakes. The effect of the developed hybrid damper is analytically confirmed.
고준위방사성폐기물 처분시스템에서는 방사성 핵종의 붕괴열과 암반으로부터의 지하수 유입으로 열응력 및 팽윤압의 발생으로 열-수리-역학적 복합거동(coupled thermo-hydro-mechanical behavior)이 예상되기 때문에 한국원자력연구원은 처분시스템 및 근계암반에서의 열-수리-역학적인 복합거동 특성을 평가하기 위해서 지하처분연구시설(KAERI Underground Research Tunnel, KURT)에서 2016년부터 현장시험(In-situ Demonstration of Engineered Barrier System, In-DEBS)을 수행 중에 있다. 본 연구에서는 In-DEBS 현장시험 데이터 분석하고 벤토나이트 완충재와 화강암반에서의 열-수리-역학적 복합거동 특성을 평가하기 위해 TOUGH2-MP/FLAC3D을 이용하여 수치해석을 수행하였다. 또한 벤토나이트 블록과 KURT 화강암의 열-수리-역학적 복합거동 특성을 평가하기 위해 사용된 각각의 열, 수리, 그리고 역학적 모델의 적합성을 평가하고 자 현장시험에서 계측된 온도, 상대습도, 그리고 변위의 결과와 수치해석으로 계산된 결과를 비교하였다. 온도와 상대습도의 계산 결과를 현장 데이터와 비교·분석한 결과, 전체적으로 유사한 경향을 보일 뿐만 아니라 시간에 따라 변화하는 정량적인 값 역시 유사하게 나타났다. 역학적 해석 결과를 살펴보면, 계산된 변위의 전반적인 경향은 유사하지만 해석 결과가 계측 값에 비해 상대적으로 작게 나타났다. 축대칭 모델을 이용하여 In-DEBS 현장시험에서 관측된 열-수리-역학적 복합거동 특성을 전반적으로 평가할 수 있었지만, 벤토나이트 블록 및 KURT 암반에서의 열-수리-역학적 복합거동을 면밀히 살펴보기 위해서는 추후 터널의 형상과 주변 KURT 터널의 영향을 반영한 3차원 해석이 필요할 것으로 판단된다. 본 연구에서 사용된 입력 물성과 열-수리-역학적 모델은 추후 In-DEBS 장기 거동 및 처분시스템에서의 열-수리-역학적 복합거동 특성을 평가하고 예측하는데 활용될 수 있을 것으로 기대된다.
환경오염물질 배출 사업장에서는 환경오염 물질 배출에 대한 규제에 대응하고 나아가 자체적인 환경오염 물질 배출 개선을 위한 환경 모니터링 시스템 운영이 필수적이다. 현재 환경관리공단에서는 일정 규모 이상의 사업장을 대상으로 TMS(Tele Metering System)를 설치하여 전국적으로 환경오염 배출 물질을 실시간 감시 중에 있으며, 환경오염 배출 기준치 초과 시에는 예・경보를 발생시키도록 대처하고 있다. 그러나 기존 대부분의 환경 모니터링 시스템들은 환경 배출 물질 초과 발생 시 원인 분석 기능이 없고 특정 측정 장소(굴뚝 상단의 배출구나 특정 수질 측정소 등)에서의 환경오염 물질 농도 데이터만 활용하고 있다. 특히 이력이 제대로 관리되지 않기 때문에 유사 문제 혹은 동일한 문제 발생 시에도 즉각적인 조치가 이루어지지 못한다. 이에 본 연구에서는 기존 환경 모니터링 시스템의 한계점을 적극 보완하여 개선된 시스템을 기획하며, IoT 센싱 기술을 기반으로 하여 실시간으로 사업장 내 이상 상황을 인지하고 원인을 분석하여 해당 조치를 작업자에게 즉각적으로 지원하는 원스톱 환경 모니터링 및 감시 진단 시스템을 개발하고자 한다.
Background : Spiraea prunifolia var. simpliciflora (Rosaceae) called “Brial wreath” is a deciduous latifoliate shrub that is widely distributed throughout in Northeast Asia. Phytochemical and biological investigation of S. prunifolia have led to the discovery of biologically active compounds. Pharmacological studies revealed that the extract of the root of S. prunifolia possess antioxidant, antipyretic and anti-inflammatory activities. Some chemical constituents such as sterols, phenolics, terpene and fatty acid, as well as ethanolic extracts from the roots of S. prunifolia, have previously been reported to modulate the deleterious effects of diabetes, to prevent high-fat diet-induced obesity, and to prevent cisplatin-induced nephrotoxicity. Our continuing research was carried out to search for other phytochemical constituents from the leavess of S. prunifolia. The chemical structures of compounds were determined by NMR and FAB/MS spectroscopic data interpretation.
Methods and Results : Multiple-preparative liquid chromatography (MPLC) purifications were carried out on YMC LC-forte/R instrument (YMC Kyoto, Japan) equipped with YMC-Pack ODS-A columns (ODS gel : 5 ㎛, 10 ㎜ × 250 ㎜). High-performance liquid chromatography (HPLC) was performed on Agilent Technologies instrument (Aglient Tec., Santa clara, CA, USA) equipped with YMC–Pack Pro C18 columns (ODS gel : 5 ㎛, 4.6 ㎜ × 250 ㎜). Next, quantitative analysis was carried out on UPLC-QqQ/MS 3200 Q-TRAP instrument (AB SCIEX Toronto, Canada) using a ACQUITY UPLC (waters corp.) with an ACQUITY BEH C18 column (2.1 ㎜ × 100 ㎜, 1.7 ㎛). The metabolite samples was applied to preparative reversed-phase HPLC and UPLC using gradient method, solvent A [water + 0.1% formic acid (v/v)] and solvent B [acetonitrile + 0.1% formic acid (v/v)].
Conclusion : In this study, we isolated the major metabolites from the stem of Spiraea prunifolia var. simpliciflora by using MPLC and HPLC. UPLC-QqQ/MS was also used to quantify target compounds. Finally, we established methodology and performed the quantitative analysis on target compounds from the stem of Spiraea prunifolia var. simpliciflora.
Background : Lythrum salicaria L. (LS), a herb that is found all around the world, has long been used as medicinal plant to treat inflammation, external wound bleeding, and diarrhea, while its sprouts (young leaves) can be utilized as a food material. The antioxidant and hepato-protective activities of LS have been reported in several articles. This study was conducted to compare the efficacy and cell proliferation of LS leaves according to their growth period, and to obtain information on the optimal harvesting time of LS as a food resource.
Methods and results : LS leaves were collected at ten-day intervals between April 27 and June 26, 2016 in Eumseong-gun, South Korea. The LS leaves were extracted with 50% ethanol at room temperature, and seven LS extracts (LSE) were obtained. A peroxynitrite (ONOO-) scavenging assay and a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay were performed to compare the antioxidant effects of LSE, while a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed on the BV-2 cell lines to determine cell viability. The total phenol contents of LSE were quantified by using the calibration curve of tannic acid. From these assays, LSE harvested on April 27 showed the lowest value, while LSE harvested on June 6 showed the highest DPPH scavenging activity at 10 ㎍/㎖. There was no difference among the extracts in terms of their peroxynitrite scavenging activity. The extract prepared on April 27 showed the highest value in terms of BV2 cell viability, while that obtained on June 6 showed the lowest value. The value in terms of the total phenol content of the LSE harvested on June 6 was the highest, whereas that of the LSE harvested on April 27 was the lowest.
Conclusion : When comparing the activity of LSE according to its harvesting time, the extract dated June 6 showed the highest effect in terms of its antioxidant activity and its total phenol content, whereas the extract dated April 27 showed the highest cell viability. As such, this study suggests that LS leaves harvested in the early season could be utilized as a food material even though they display low efficacy.
Background : The development of an antioxidant to prevent disease by ROS-induced oxidative stress is necessary. This study investigated the changes of antioxidant capacities of two medicinal crops extracts by lactic acid fermentation.
Methods and Results : The changes of free-radical scavenging activity of medicinal crops extracts by lactic acid fermentation were evaluated by using DPPH free-radical scavenging assay and ABTS free-radical scavenging assay. The DPPH free-radical scavenging activity of extracts or lactic acid fermented extracts were estimated as followed. samples were thoroughly mixed with 1 ㎖ ethanol solution of 0.1 mM DPPH. After stand for 30 min in the dark, the absorbance was measured at 570 ㎚ by using a UV Spectrophotometer. ABTS scavenging activity of extracts or lactic acid fermented extracts were estimated as followed. The working solution was prepared by mixing 1 ㎖ of ABTS solution with 88 ㎖ of 50% ethanol. A total of 25 ㎕ of samples were mixed with 225 ㎕ of ABTS working solution and allowed to stand for 10 min. The absorbance was read at 732 ㎚ in a UV spectrophotometer. The data were showed that lactic acid fermented extracts were higher antioxidant ability than the extracts.
Conclusion : This study was showed that the antioxidant capacities of two medicinal crops extracts were improved by lactic acid fermentation.
Background: The demand of recycling renewable agricultural by-products is increasing. Radiation breeding is a method used to improve saccharification efficiency. Thus, we investigated the effect of gamma ray irradiation on the pretreatment and enzymatic hydrolysis of the stalks of Senna tora, an important medicinal plants.
Methods and Results: S. tora seeds were irradiated with gamma ray at doses of 100, 200, 300, and 400 Gy. In the pretreated biomass, glucan and lignin content were higher in the M1 (1st generations of irradiation) S. tora stalks than in the M2 (2nd generations of irradiation) stalks, this can be explained by the higher degradation rate in M1. After oxalic acid pretreatment, the concentration of total phenolic compounds (TPCs) in the hydrolysate increased in the gamma ray treated seeds. The highest relative increase rate in crystallinity in the pretreated biomass was observed in M1-400 Gy and M2-100 Gy. The cellulose conversion rate was higher in M1 than in M2, except for 200 Gy.
Conclusions: Gamma ray irradiation at an appropriate dose can be used to improve the efficiency of pretreatment and enzymatic hydrolysis, thereby increasing biomass availability.
This study was performed an experimental study on mortar containing phytoncide solution. The compressive strength properties with various phytoncide containing ratios were evaluated. The phytoncide solution containing ratios adopted in this study were 0, 2, 4, 6, 8 and 10%. The compressive strength was measured at 3, 7 and 28 days for the hardened mortar specimens. According to the experimental results, the phytoncide has not affect the compressive strength and flow.
Background: Allergic diseases like such as atopic dermatitis, asthma, and rhinitis have recently increased both domestically and globally. The present study was undertaken to select candidates with anti-allergic activity from plant resources. Methods and Results: Fifty-six plant extracts at 20㎍/㎖ were screened against β-hexosaminidase production and interleukin (IL)- 4 release in degranulated rat basophilic leukemia (RBL)-2H3 cells. The anti-allergy activity of three plant extracts selected from the preliminary screening experiment, Polygonatum sibiricum F. Delaroche (root), Pyrus pytifolia var. culta (Makino) Nakai (leaf), and Rehmannia glutinosa (Gaertn.) Libosch. ex Steud (root) were measured at concentrations of 2 - 250㎍/㎖ in three cell lines as RBL- 2H3, HaCaT and Jurkcat T cells. The assay showed the root extract of R. glutinosa to have an inhibitory activity of 4.2% - 28.6% on β-hexosaminidase production from IgE-sensitized RBL-2H3 cells. Each extract of P. sibiricum and R. glutinosa reduced IL-4 release in IgE-sensitized RBL-2H3 cells, respectively. The leaf extract of P. pyrifolia var. culta showed a significantly potent suppressive effect of 10.2% - 74.7% on the mRNA expression of tumor necrosis factor (TNF)-α in HaCaT cells sensitized with TNF-a and INF-g, and showed inhibitory effect of –8.6% - 90.9% on the mRNA expression of IL-2 in Jurkat T cells sensitized with PMA and A23187. Conclusions: The results showed that the root of R. glutinosa and leaf of P. pyrifolia var. culta could be useful candidates as antiallergy materials.
KAERI의 PRIDE 시설에서 공학규모의 전해환원용 원료물질인 UO2 다공성펠렛 제조를 위해 공정과 장치를 최적화시킨 내 용을 다루었다. UO2 분말과 별도로 attrition 밀링된 대용산화물 분말을 출발분말로, 정밀 칭량을 통해 사용후핵연료 조성을 모사하였다(Simfuel). Simfuel 분말은 각각 tumbling mixer로 혼합하여 균질화 하고, rotary press로 성형하여 furnace를 이 용해 소결하였다. 4% H2-Ar 분위기에서 1450℃ 24시간 고온 열처리하여 제조된 소결펠렛은 6.89 g·cm-3의 벌크밀도를 가 지며 이는 후속 전해환원 공정의 요구에 부합한다. 소결된 다공성펠렛의 미세구조 관찰을 통해 다공성 기지상과 함께 산화/ 금속 석출물이 관찰되어 사용후핵연료의 상이 모사됨을 확인하였다. 본 결과는 향후 공학규모 이상의 파이로 연구를 위한 UO2 다공성펠렛 제조에 중요한 기초자료로 활용 될 것이다.
Background: Senna tora is a flowering plant in the legume family Fabaceae. Its seeds are roasted and consumed as tea in Asia, to reduce inflammation in the liver and improve eyesight. Thus, it has been considered as an important medicinal crops in Asia. However, breeding trials to improve its genetic properties are rare. Mutation breeding by gamma ray is known to be an effective and highly successful approach for the generation of agronomically useful cultivars. Here we analyzed the effects of several dosages of gamma ray on the biological conditions of Senna tora seeds. Methods and Results: The germination rate and growth patterns of Senna tora were examined following irradiation with gamma ray at 100, 200, 300 and 400 Gy. The total phenolic compound contents and antioxidant activities of Senna tora were analyzed. Germination increased at 100 and 200 Gy in the M1 and M2 generations compared with that of the control (M0). The total phenolic compound contents and antioxidant activity of the seeds significantly decreased as the radiation dosage increased above 100 Gy in the M1 generation. Conclusions: Senna tora, irradiated with gamma ray at dosages 100, 200, 300, and 400 Gy, showed maximum germination rate at 200 Gy in the M2 generation. Plant height and leaf size gradually decreased with increasing gamma ray intensity in the M2 generation. The total phenolic compound contents decreased significantly at 400 Gy, and the related antioxidant activity was also decreased as the radiation dosage increased.
이동형해상감시레이더는 해안을 따라 이동하며, 해역을 감시하는 기능을 수행한다. 초기 레이더의 방향은 차량의 선수방향으로 정 렬되어 있기 때문에 전개지 이동 후 신속하게 표적의 방위각을 획득하기 위해서는 변경된 차량의 선수방향을 아는 것이 중요하다. 차량의 선 수방위각은 자이로 컴퍼스, GPS 컴퍼스 혹은 전자 컴퍼스로 획득할 수 있다. 그 중에서 전자 컴퍼스는 가격이 저렴할 뿐만 아니라, 부피가 작고, 안정화 시간이 짧아서 빠른 기동성을 요구하는 이동형해상감시레이더에 적합하다. 하지만, 지자계 센서를 사용하다보니 주변 자장의 영 향으로 오차가 발생될 수 있으며, 발생된 오차는 초기 위성의 자동추적을 어렵게 하고, 레이더의 탐지정확도를 떨어뜨린다. 따라서 본 논문에 서는 이동형해상감시레이더 및 정지 위성간의 두 위치좌표로부터 측지학적 역 문제 해석을 통해 기준 방위각을 산출하고 이를 위성 안테나가 실제 지향한 방위각과 비교 산출하여 얻어진 보정값을 레이더에 반영하는 자동보정절차를 제안하고 제안된 방법을 실제 운용 중인 이동형해 상감시레이더에 적용함으로써 운용가능성 및 편리성을 검증하였다.
Background : While the anti-inflammatory effects of 20 (S)-ginsenoside Rg3 (Rg3) have been studied, it remains unclear how Rg3 regulates lipid metabolism in inflammatory macrophages. Thus, in this study, we characterized some eicosanoids related to the anti-inflammatory effects of 20 (S)-ginsenoside Rg3 in murine macrophages. Methods and Results : UPLC-MS/MS was used to profile various eicosanoids from RAW264.7 cells treated with lipopolysaccharide (LPS) and Rg3. The profiling data were statistically analyzed by principal component analysis, hierarchical clustering analysis and analysis of variance. The anti-inflammatory effect of Rg3 was validated by assessing the levels of nitric oxide, tumor necrosis factor-α, and interleukin-6 in the activated macrophages treated with Rg3. A total of 69 eicosanoids were analyzed in RAW264.7 cells. Principal component and hierarchical cluster analyses differentiated control cells from cells treated with LPS, Rg3, or LPS + Rg3 for 12 or 24 h. Furthermore, some differentially regulated compounds were found between macrophages treated with LPS for 24 h and those treated with LPS + Rg3 for 24 h. Conclusion : Rg3 alters eicosanoid metabolism in activated macrophages treated with LPS. Furthermore, we identified several eicosanoids correlated with the anti-inflammatory activity of Rg3.
Background : Methicillin-Resistant Staphylococcus aureus (MRSA) is a multidrug-resistant (MDR) strain. Especially, MRSA is developing resistance to available antibacterial agents and causing complications in the treatment of infections related to skin, soft tissue, respiratory, bone, joint, and endovascular disorders. Therefore, antibacterial agent combination therapy appears to be a useful option, particularly in developing countries where antibiotic availability is limited. (+)-Usnic acid (UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. Methods and Results : In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against MRSA. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid (EDTA) was used. In the other hand, Sodium azide (NaN3) was used as inhibitors of ATPase. These results suggest that the antibacterial effect of UA was potentiated by membrane-binding agents and ABC transporter-inhibiting agents, implying that antibacterial activity is associated with damage of the cell wall and inhibition of ATPase function by UA. Conclusion : UA and in combination with EDTA and NaN3 could lead to the development of new combination antibiotics against MRSA infection. The results of this study appear to be promising, and they are expected to enhance the use of natural products as drugs.