• Title/Summary/Keyword: effective diffusion

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Prediction of Leachate Migration from Waste Disposal Site to Underground LPG Storage Facility and Review of Contamination Control Method by Numerical Simulations (수치모의를 통한 지하 LPG 저장시설에 인접한 폐기물매립지에서의 침출수이동 예측 및 제어공법 검토)

  • 한일영;서일원;오경택
    • Journal of the Korean Society of Groundwater Environment
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    • v.3 no.2
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    • pp.51-59
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    • 1996
  • In case waste disposal site is to be constructed close to the underground facilities such as LPG storage cavern which is completely maintained by groundwater pressure, it is generally requested that the possibility on leachate contamination of cavern area be reviewed and the countermeasure, if it is estimated cavern area is severely affected by leachate, be taken into consideration. Prediction was performed and leachate control plan was made using by analytical and the numerical analysis on the leachate migration which is likely to happen at the area between the proposed waste disposal site and the underground LPG storage cavern located at the U petrochemical complex. Analytical solutions were obtained by the conservative mass advection-diffusion equation and the effect of advection and dispersion factor on the leachate migration was reviewed through peclet number calculation and the functional relationship between the factors and leachate transport velocity was established, which leads to enable us to predict the leachate transport velocity without difficulties when different parameters (factors) are used for analytical solution. Numerical solutions were obtained by FEM using AQUA2D which is for the simulation of groundwater flow and contaminant transport. 3-D discrete fracture models were simulated and fracture flow analysis was performed and feasibility study on the water-curtain system was conducted through the fracture connectivity analysis in rock mass. As results of those analyses, it was interpreted that the leachate would trespass on the LPG storage cavern area in 30 years from the proposed wate disposal site and the vertical water-curtain system was effective mathod for the prevention of leachate's migration further into the cavern area.

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A Study on System Interconnection for National R&D Information Diffusion (범부처 국가R&D정보 공동 활용을 위한 시스템 연계 방안 연구)

  • Choi, Heeseok;Lim, Chul-Su;Lee, Byeong-Hee;Kwon, Lee-Nam;Kim, Tae-Hyun;Kim, Yun-Jeong;Shin, Donggu;Kim, Jae-Soo
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.396-400
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    • 2007
  • Linking of the national R&D information between different ministries is a difficult task because they were all constructed independently. A standard infrastructure for the dissemination of such R&D information is required. This paper suggests a distributed integration method for the effective linking, gathering and integration of national R&D information. R&D management institutes designated by each ministry will gather and manage all the R&D information produced using the budget by the ministry and the information required for the integrated management of national R&D will be gathered from this information. Standardization of the R&D information, linking procedure and the construction method for the data linking software will be defined in this paper. The usage of R&D information will be processed more effectively to maximize the utiliation and productivity of national R&D activities.

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Evaluation on Chloride Binding Capacity of Mineral Mixed Paste Containing an Alkaline Activator (알칼리 활성화제를 사용한 무기질 혼합 페이스트의 염화물이온 고정화 평가)

  • Cho, Gyu-Hwan;Yeo, In-Hwan;Ji, Dong-Hun
    • Journal of the Korea Concrete Institute
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    • v.28 no.2
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    • pp.157-165
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    • 2016
  • It is possible to achieve high strength ranging from 40 MPa to 70 MPa in alkali-activated slag concrete (AASC), and AASC is also known to have a finer pore structure due to its high latent hydraulicity and fineness of slag cement, which makes it difficult for chloride ions to penetrate. Electrophoresis is mostly used to calculate the effective diffusion coefficient of chloride ions, and then to evaluate resistance to salt damage. Few studies have been conducted on the fixation capacity of chloride ions in AASC. For this reason, in this study the chloride fixation within the hardened paste was evaluated according to the type and the amount of alkaline activators. As a result, it was revealed that among the test specimens, the chloride fixation was greatest in the paste containing $Na_2SiO_3$. In addition, it was found that as more activator was added, a higher level of chloride fixation was observed. Through this analysis, it can be concluded that the type and the amount of alkaline activators have a high correlation with the amount of C-S-H produced.

Changes of Serum antibody Levels by Indirect Hemagglutination Test after Treatment in Clonorchiasis (IHA(Indirect hemagglutination test)를 이용한 간흡충증(肝吸虫症)의 면역혈청학적(免疫血淸學的) 진단(診斷)에 관한 연구(硏究) -ELISA법과의 비교(比較) 및 치료(治療) 전후(前後) 의 혈청항체가(血淸抗體價) 변동(變動)에 관하여-)

  • Joo, Kyoung-Hwan;Kim, Jong-Seong;Chung, Myung-Sook;Rim, Han-Jong
    • Journal of agricultural medicine and community health
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    • v.12 no.1
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    • pp.117-123
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    • 1987
  • Detection of IgG antibody in clonorchiasis has been accomplished through various serodiagnostic procedure including complement fixation test, gel diffusion test, indirect fluorescent antibody test, indirect hemagglutination test etc. In this report enzyme immunoassay (ELISA) and indirect hemagglutination test (IHA) were used to determine IgG serum antibody levels before and after therapy with praziquantel. Briefly, sera from 62 cases of confirmed human clonorchiasis were examined before and after treatment with praziquantel. Among 62 cases treated 25 cases were categorized as completely cured groups by formalin-ether and careful examination of 4 cellophane thick smered slides at 18 months after treatment. The sera of 25 cases of cured groups were examined again by ELISA and IHA, and com-pared to the previous data. The results obtained were as follows; 1) Sensitivity of IHA test was 83.6% when cut-off titer of 1:8 was applied. No sera obtained from 10 normal healthy control showed positive reaction. 2) Twenty cases (80.0%) out of 25 cured one showed negative results by IHA at 18 months after treatment. 3) Although 5 cases showed positive titer even 18 months after treatment 3 cases of them showed decreased antibody titer. However 2 cases did not show any response. 4) Even though almost all cases showed de- creased ELISA value, only 11 cases (44.0%) out of 25 patients showed negative results by ELISA at 18 months after treatment. In conclusion, it is suggested that, while IgG ELISA for detecting long persisting antibody was more sensitive than IHA, IHA results more conclusively indicated effective treatment in clonorchiasis by negative conversion than did the results of ELISA.

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The Perception on Alternative Therapy of Adults in Some Areas (일부 지역 성인의 대체요법에 대한 인식도)

  • Gim, Nan-Hee;Hong, Seong-Gyun
    • Journal of the Korean Society of Radiology
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    • v.1 no.2
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    • pp.37-53
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    • 2007
  • This study is carried in the goal to investigate the individual awareness rate about alternative therapy among the unspecified persons and their experience of using it, and to promote the diffusion of alternative therapy. The questionnaire research for this study has been conducted among 300 unspecified persons who live in some areas. The following is figured out in this study: 1. To the question of knowledge grade about alternative therapies, 44.4% of respondents answer they 'know a little.' 2. Regarding the experience of using alternative therapies, 22.6% of respondents answer 'Yes.' This rate is very low, the reason of it can be perceived that the names of categories in alternative therapies has not been showed to them and they don't have pre-knowledge about it. 3. The 166 persons of 248 reply that they use alternative therapies. This rate indicate their recognition of categories of alternative therapies, and the gap of the question of experience and using nowadays is interpreted to result from the gap of the pre-knowledge. 4. Regarding the field of the alternative therapies that the respondents want to learn, the first field the male respondents choose is acupuncture(41 persons, Res in needle, bloodletting, etc.), and the female respondents choose acupuncture firstly(20 persons). Therefore the learning courses of alternative therapies are more effective when the preference of men and women is considered. Consequently, both the research about the given kinds of alternative therapies with demonstration of their medical effect and the systematic promotion and education about alternative therapy is considered to be needed.

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Antibacterial effects of natural products on Vibrio vulnificus growth in seawater and shellfish (바닷물과 조개에서 패혈증비브리오균 증식에 대한 천연물의 항균 효과)

  • Hong, Yeongjin;Ryu, Phil Youl;Kim, Seung Yong;Yeom, Kyung Min;Park, Jung Up;Jo, Se Jin;Guo, Rui Hong;Tran, The Bach;Jin, Hang;Kim, Young Ran
    • Korean Journal of Food Science and Technology
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    • v.52 no.1
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    • pp.89-93
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    • 2020
  • Vibrio vulnificus, an opportunistic pathogen, causes septicaemia when raw shellfish and fish are eaten by patients with hepatic diseases or reduced immunity. In this study, we evaluated inhibitory effects of some natural products on V. vulnificus growth using 96-well microplate assay. We found that Phyllanthus emblica L., Rosa chinensis Jacq., Rosa rugose Thub., and Chukrasia tabularis A. Juss. significantly inhibited V. vulnificus growth in Luria-Bertani (LB) broth. Among these four extracts, the inhibition diameter of Chukrasia tabularis was 16.00 ± 0.58 mm in disc diffusion assay on V. vulnificus growth. In addition, these four natural products protected HeLa cells from V. vulnificus-induced cytotoxicity. A cocktail containing these four products showed an inhibitory effect on V. vulnificus growth in seawater and shellfish by reducing its growth by 75.7% and 97%, respectively. These results suggest that these four natural products are safe and effective natural antimicrobial candidates to prevent V. vulnificus infection.

Development of Antagonistic Microorganism for Biological Control of Pythium Blight of Turfgrass (잔디 피시움마름병(Pythium blight)의 생물학적 방제를 위한 길항 미생물의 선발과 효력 검정)

  • Jung, Woo-Chul;Shin, Taek-Su;Do, Ki-Suk;Kim, Won-Kuk;Lee, Jae-Ho;Choi, Ki-Hyun
    • Research in Plant Disease
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    • v.12 no.3
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    • pp.260-266
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    • 2006
  • Pythium blight caused by Pythium spp. is one of major diseases in putting green of golf course. In this study, microorganisms which are anatgonistic to Pythium aphanidermatum, a pathogen of pythium blight, were selected primary through in vitro tests, dual culture method and triple layer agar diffusion method. In vivo test against pythium blight were conducted to select the best candidate biocontrol microorganism by pot experiment in a plastic house. Bacillus subtilis GB-0365 was finally selected as a biocontrol agent against pythium blight. Relative Performance Indies(RPI) was used as a criterion of selecting potential biocontrol agent. B. subtilis GB-0365 showed resistance to major synthetic agrochemicals used in golf course. Alternative application of synthetic agrochemicals and B. subtilis GB-0365 was most effective to successfully contol pythium blight. B. subtilis GB-0365 suppressed the development of pythium bight of bentgrass by 56.4% as compared to non-treated control and its disease control efficacy was 60.9% of a synthetic fungicide Oxapro(WP) efficacy. B. subtilis GB-0365 has a potential to be a biocontrol agent for control of pythium blight.

Isolation of Salmonella from the layer chickens reacting in pullorum-typhoid agglutination test (추백리 혈청검사 양성 산란계로부터 Salmonella속균 분리)

  • 류재윤;전무형;장경수;손현수;곽학구;박경재;우용구
    • Korean Journal of Veterinary Service
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    • v.22 no.3
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    • pp.221-237
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    • 1999
  • To investigate the specificity of rapid slide agglutination test for pullorum-gallinarum diseases and to obtain a basic data for avian salmonellosis control, salmonella isolation was peformed for the layer chickens positively reacted in pullonlm-typhoid agglutination test. The biochemical, serological and antimicrobial properties of the isolates were examined. The results obtained through this study were summarized as follows; 1. Of 2,384 chickens tested by the agglutination test, 606 chickens (25.4%) were positive reactors. 154 of 606 reactors and 49 of the non-reacting chickens were investigated for salmonella isolation, resulting in isolation of 68 strains of salmonellae from 27 chickens. 2. By organs, the isolation frequency from liver, cecum, spleen, ovary and gall bladder showed 8.9% (18 strains), 8.9% (18 strains), 7.4% (15 strains), 4.4% (9 strains) and 3.9% (8 strains), respectively. 3. By culture medium the combination of selenite broth and MacConkey agar revealed the highest isolation rate and the enrichment culture by delayed secondary enrichment culture method was found the most effective for salmonella isolation. 4. The serotypes of 68 salmonella isolates were identified as 3 strains of S pullorum, 24 strains of S gallinarum, 15 strains of S typhimurium, 8 strains of S enteritidis, 7 strains of S paratyphi A, 5 strains of S typhimurium and 6 strains of the other salmonellae. 5. The serotypes of 8 salmonella strains isolated from 49 chickens non-reacting in pullorum-typhoid agglutination test were identified as 3 strains of S typhimurium and 5 strains of S infantis. 6. When 24 chickens of which 68 strains of salmonellae isolated were examined by microplate agglutination test, the average antibody titer for pullorum antigen was $2^{5.25}$. The chickens at antibody titer between $2^3$ and $2^5$ showed the higher frequency of isolation as compared with the chickens at the other titers. 7. When salmonella isolates were tested the antimicrobial drug sensitivity by disk diffusion method, S paratyphi A were highly sensitive by 100% to ATM and GM, S typhimurium, by 88% to AM, CIP, IMP and TN, S infantis, by 100% to AM, CRO, ENR and PIP, S enteritidis,by 100% to IMP and PIP, S pullorum, by 100% to ATM, CRO, ENR and PIP and S gallinarum, by 92% to CRO, CIP and PIP.

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Model Study of the Fate of Hydrocarbons in the Soil-Plant Environment (녹지 토양내 탄화수소화합물의 분포변화에 관한 모델링 연구)

  • Yoon-Young Chang;Kyung-Yub Hwang
    • Journal of Korea Soil Environment Society
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    • v.1 no.2
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    • pp.91-101
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    • 1996
  • In recent years, phytoremediation, the use of plants to detoxify hydrocarbons, has been a promising new area of research, particularly in situ cleanup of large volumes of slightly contaminated soils. There is increasing need for a mathematical model that can be used as a predictive tool prior to actual field implementation of such a relatively new technique. Although a number of models exist for solute-plant interaction in the vegetated zone of soil, most of them have focused on ionic nutrients and some metals. In this study, we developed a mathematical model for simulation of bioremediation of hydrocarbons in soil, associated with plant root systems. The proposed model includes root interactions with soil-water and hydrocarbons in time and space, as well as advective and dispersive transport in unsaturated soil. The developed model considers gas phase diffusion and liquid-gas mass exchanges. For simulation of temporal and spatial changes in root behavior on soil-water and with hydrocarbons, time-specific distribution of root quantity through soil was incorporated into the simulation model. Hydrocarbon absorption and subsequent uptake into roots with water were simulated with empirical equations. In addition, microbial activity in the rhizosphere, a zone of unique interaction between roots and soil microorganisms, was modeled using a biofilm theory. This mathematical model for understanding and predicting fate and transport of compound in plant-aided remediation will assist effective application of plant-aided remediation to field contamination.

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Investigation on Antibacterial and Antioxidant Activities, Phenolic and Flavonoid Contents of Some Thai Edible Plants as an Alternative for Antibiotics

  • Lee, J.H.;Cho, S.;Paik, H.D.;Choi, C.W.;Nam, K.T.;Hwang, S.G.;Kim, Soo-Ki
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.10
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    • pp.1461-1468
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    • 2014
  • This study was aimed to examine the antibacterial and antioxidative properties of seven edible plants from Thailand to develop alternative antibiotics as feed additives. The plants include Citrus aurantifolia Swingle (Lime) fruits and its leaves, Sesbania grandiflora L. (Agati sesbania) leaves, Piper sarmentosum Roxb (Wild betal) leaves, Curcuma domestica Valeton (Turmeric) roots, Morinda citrifolia L. (Beach mulberry) leaves, Cassia siamea britt (Siamea cassia) leaves, and Cocos nucifera L. (Coconut) peels. The plants were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. Antibacterial activities with minimum inhibitory concentration (MIC) were determined by agar diffusion assay against Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, and Clostridium perfringens that were considered pathogenic strains in livestock infection. Methanol extracts of C. aurantifolia Swingle fruits and leaves showed the broadest spectrum of antibacterial activities except for C. perfringens. Butanol extract of S. grandiflora L. leaves showed the strongest activity against Burkholderia sp. with MIC, $135{\mu}g/mL$. P. sarmentosum Roxb leaves showed antibacterial activities against E. coli, Burkholderia sp. and H. parasuis. Ethyl acetate and water extracts from C. domesitca Valeton roots showed MIC of $306{\mu}g/mL$ and $183{\mu}g/mL$, respectively against only C. perfringens. Antioxidative activity was determined by 2-diphenyl-2-picryl hydrazyl photometric assay. The methanol extracts of C. aurantifolia Swingle fruits and P. sarmentosum Roxb leaves showed the highest antioxidant activity among all the extracts with 3.46 mg/mL and 2.70 mg/mL effective concentration 50% ($EC_{50}$) values, respectively. Total contents of phenolics and flavonoids were measured from the plant extracts. Methanol extracts of S. grandiflora L. and chloroform extracts of C. domestica Valeton were found to have the highest amount of total phenolics, 41.7 and $47.8{\mu}g/mL$, respectively. Flavonoid content of methanol extracts in S. grandiflora L. T was $22.5{\mu}g/mL$ and the highest among plant extracts tested. These results indicated that C. aurantifolia Swingle, S. grandiflora L., P. sarmentosum Roxb, and C. domestica Valeton have antibacterial and antioxidant activities and can be used as alternative antibiotics or potential feed additives for the control of animal pathogenic bacteria.