• Title/Summary/Keyword: Tracer Test

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Transport of Zn Ion under various pH Conditions in a Sandy Soil (사질토양에서의 pH조건에 따른 Zn의 이동특성)

  • Park, Min-Soo;Kim, Dong-Ju
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.1
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    • pp.33-42
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    • 2000
  • Adsorption onto the surfaces of solid particles is a well known phenomenon that causes the retardation effect of heavy metals in soils. For adequate remediation of soil and groundwater contamination, it is important to investigate the mobility of heavy metals that largely depends on pH conditions in the soil water since adsorption of heavy metals is pH-dependent. In this study, we investigated the transport of Zn ion under various pH conditions in a sandy soil by conducting batch and column tests. The batch test was performed using the standard procedure of equilibrating fine fractions collected from the soil with eleven different initial $ZnCl_2$ concentrations, and analysis of Zn ion in the equilibrated solutions using ICP-AES. The column test consisted of monitoring the concentrations of soil solutions exiting the soil column with time known as a breakthrough curve (BTC). We injected respectively $ZnCl_2$ and KCl solutions with the concentration of 10 g/L as a tracer in a square pulse type under three different pH conditions (7.7, 5.8, 4.1) and monitored the flux concentration at the exit boundary using an EC meter and ICP-AES. The resident concentration was also monitored at the 10cm-depth by Time Domain Reflectometry (TDR). The results of batch test showed that ion exchange process between Zn and other cations (Ca, Mg) was predominant. The retardation coefficients obtained from adsorption isotherms (Linear, Freundlich, Langmuir) resulted in the various values ranging from 1.2 to 614.1. No retardation effect but ion exchange was found for the BTCs under all pH conditions. This can be explained by the absence of other cations to desorb Zn ion from soil exchange sites under the conditions of ETC experiment imposing blank water as leachate in steady-state flow. As pH decreased, the peak concentration of Zn increased due to the competition of Zn with hydrogen ions ($H^+$) and the concentrations of other cations decreased. The peak concentration of Zn was increased by 12.7 times as pH decreased from 7.7 to 4.1.

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Antifungal effects of synthetic human β-defensin 3-C15 peptide

  • Lim, Sang-Min;Ahn, Ki-Bum;Kim, Christine;Kum, Jong-Won;Perinpanayagam, Hiran;Gu, Yu;Yoo, Yeon-Jee;Chang, Seok Woo;Han, Seung Hyun;Shon, Won-Jun;Lee, Woocheol;Baek, Seung-Ho;Zhu, Qiang;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.41 no.2
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    • pp.91-97
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    • 2016
  • Objectives: The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human ${\beta}$-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. Materials and Methods: C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and $300{\mu}g/mL$), CH ($100{\mu}g/mL$), and Nys ($20{\mu}g/mL$) for 7 days at $37^{\circ}C$. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a two-tailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. Results: C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (${\geq}100{\mu}g/mL$). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (${\geq}100{\mu}g/mL$) showed significant fungicidal activity compared to CH group (p < 0.05). Conclusions: Synthetic HBD3-C15 peptide (${\geq}100{\mu}g/mL$) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm.

Development and Assessment Individual Maximum Permissible Dose Method of I-131 Therapy in High Risk Patients with Differentiated Papillary Thyroid Cancer (물리학 선량법을 이용한 갑상선암의 개인별 최대안전용량 I-131 치료법 개발과 유용성 평가)

  • Kim, Jeong-Chul;Yoon, Jung-Han;Bom, Hee-Seung;JaeGal, Young-Jong;Song, Ho-Chun;Min, Jung-Joon;Jeong, Heong;Kim, Seong-Min;Heo, Young-Jun;Li, Ming-Hao;Park, Young-Kyu;Chung, June-Key
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.2
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    • pp.110-119
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    • 2003
  • Purpose: Radioiodine (I-131) therapy is an effective modality to reduce both recurrence and mortality rates in differentiated thyroid cancer. Whether higher doses shows higher therapeutic responses was still debatable. The purpose of this study was to validate curve-fitting (CF) method measuring maximum permissible dose (MPD) by a biological dosimetry using metaphase analysis of peripheral blood lymphocytes. Materials and Methods: Therapeutic effects of MPD was evaluated in 58 patients (49 females and 9 males, mean age $50{\pm}11$ years) of papillary thyroid cancer. Among them 43 patients were treated with ${\Leq}7.4GBq$, while 15 patients with ${\geq}9.25GBq$. The former was defined as low-dose group, and the latter high-dose group. Therapeutic response was defined as complete response when complete disappearance of lesions on follow-up I-131 scan and undetectable serum thyroglobulin levels were found. Statistical comparison between groups were done using chi-square test. P value less than 0.05 was regarded as statistically significant. Results: MPD measured by CF method using tracer and therapeutic doses were $13.3{\pm}1.9\;and\;13.8{\pm}2.1GBq$, respectively (p=0.20). They showed a significant correlation (r=0.8, p<0.0001). Exposed doses to blood measured by CF and biological methods were $1.54{\pm}0.03\;and\;1.78{\pm}0.03Gy$ (p=0.01). They also showed a significant correlation (r=0.86, p=0.01). High-dose group showed a significantly higher rate of complete response (12/15, 80%) as compared to the low-dose group (22/43, 51.2%) (p=0.05). While occurrence of side effects was not different between two groups (40% vs. 30.2%, p=0.46). Conclusion: Measurement of MPD using CF method is reliable, and the high-dose I-131 therapy using MPD gains significantly higher therapeutic effects as compared with low-dose therapy.

Reproducibility of Adenosine Tc-99m sestaMIBI SPECT for the Diagnosis of Coronary Artery Disease (관동맥질환의 진단을 위한 아데노신 Tc-99m sestaMIBI SPECT의 재현성)

  • Lee, Duk-Young;Bae, Jin-Ho;Lee, Sang-Woo;Chun, Kyung-Ah;Yoo, Jeong-Soo;Ahn, Byeong-Cheol;Ha, Jeoung-Hee;Chae, Shung-Chull;Lee, Kyu-Bo;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.6
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    • pp.473-480
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    • 2005
  • Purpose: Adenosine myocardial perfusion SPECT has proven to be useful in the detection of coronary artery disease, in the follow up the success of various therapeutic regimens and in assessing the prognosis of coronary artery disease. The purpose of this study is to define the reproducibility of myocardial perfusion SPECT using adenosine stress testing between two consecutive Tc-99m sestaMIBI (MIBI) SPECT studies in the same subjects. Methods: Thirty patients suspected of coronary artery disease in stable condition underwent sequential Tc-99m MIBI SPECT studies using intravenous adenosine. Gamma camera, acquisition and processing protocols used for the two tests were identical and no invasive procedures were performed between two tests. Mean interval between two tests were 4.1 days (range: 2-11 days). The left ventricular wall was divided into na segments and the degree of myocardial tracer uptake was graded with four-point scoring system by visual analysis. Images were interpretated by two independent nuclear medicine physicians and consensus was taken for final decision, if segmental score was not agreeable. Results: Hemodynamic responses to adenosine were not different between two consecutive studies. There were no serious side effects to stop infusion of adenosine and side effects profile was not different. When myocardial uptake was divided into normal and abnormal uptake, 481 of 540 segments were concordant (agreement rate 89%, Kappa index 0.74). With four-grade storing system, exact agreement was 81.3% (439 of 540 segments, tau b=0.73). One and two-grade differences were observed in 97 segments (18%) and 4 segments (0.7%) respectively, but three-grade difference was not observed in any segment. Extent and severity scores were not different between two studios. The extent and severity scores of the perfusion defect revealed excellent positive correlation between two test (r value for percentage extent and severity score is 0.982 and 0.965, p<0.001) Conclusion: Hemodynamic responses and side effects profile were not different between two consecutive adenosine stress tests in the same subjects. Adenosine Tc-99m sestaMIBI SPECT is highly reproducible, and could be used to assess temporal changes in myocardial perfusion in individual patients.

Current Status of Korean Ginseng Research (한국인삼론(韓國人蔘論))

  • Han, Byung-Hoon
    • Korean Journal of Pharmacognosy
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    • v.3 no.3
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    • pp.151-160
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    • 1972
  • Recent achievements of scientific research on the pharmacologic activities and the chemical problems of dammalene glycosides, which are considered to be effective principles of Korean ginseng, are reviewed and analyzed in view of structure-activity relationship. 1) S. Shibata and his co-workers detected 12 glycoside spots of dammalene series on the two dimensional T.L.C. of total glycoside fraction from Japanese ginseng, and designated them Ginsenoside Rx(x=a, b, c, g, h, etc.) in the order of increasing Rf-value. The aglycones of those glycosides were characterized to be protopanaxadiol for the Ginsenoside $Rx(x=a,\;b_{1},\;b_{2},\;c,\;d,\;e,\;f)$ and protopanaxatriol for the Ginsenoside $Rx(x=g_{1},\;g_{2},\;g_{3},\;h_{1}\;'h_{2})$. Using Korean ginseng as the material for our study, the author and his coworkers isolated a new dammalene glycoside(Panax Saponin C), which comes under the category of protopanaxadiol glycosides based on the classification of S. Shibata et al., and characterized this saponin to be the glycoside of protopanaxatriol series. Furthermore, Panax Saponin C dissociated into $two\;components(C_{1}\;and\;C_{2}-acetate)$ by acetylation, both of which returned to original Panax Saponin C by deacetylation. Based on this result, more than 13 glycoside components of dammalene series will be expected in the Korean ginseng. 2) The structures of protopanaxadiol and protopanaxatriol, the genuine aglycones of dammalene glycosides, are fully established to be structural analogues by S. Shibata and his co-workers, therefore antagonistic and/or analogical activities will be expected for the pharmacologic activities of these glycoside series of structural analogues. K. Takaki and his co-workers found central nervous system (CNS) stimmulant activity from the glycosides of protopanaxatriol series and CNS-depressant activity from the glycosides of protopanaxadiol series. On the other hand, the author and his co-workers found stimmulating activity on the protein synthesis from both the series of dammalene glycosides with delayed and long-lasting characteristics. This delayed and long-lasting characteristics were also observed in the anti-inflammatory activity of glycosides of protopanaxatriol series on their time course tendency. For the convenience's sake of argument, pluralistic pharmacologic activities of dammalene glycosides, which were observed by many workers at various pharmacologic site, may be classified into two main categories; one is pan-cellular activity and the other is organ specific activity to the certain tissue which is a mass of cells differentiated to a certain direction for their special functions in the body. Based on the data of K. Takaki and those of the authors, following assumption will be probable; Pharmacologic activities of both series of glycosides of protopanaxadiol and protopanaxatriol aglycones may be antagonistic on their tissue-specific activities and analogic on their pan-cellular activities. Therefore, the mixture of these two series of glycosides in an appropriate ratio, as the case of total extract of Korean ginseng, will be probably beneficial to the host by increasing the synthesis of some functional proteins, due to the additive action of pan-cellular activity, and with the disappearance of any significant behavioral symptoms due to the antagonism of tissue specific activity. This fact will probably be the main reason why classical trials of pharmacologists failed in re-discovering the efficacy of Korean ginseng with their behavioral test. 3) The author and his co-workers achieved the synthesis of $C^{14}-labelled\;Panax\;Saponin\;A\;on\;C_{25}-C_{27}\;position\;of\;aglycone$ in the interest of tracer studies in vivo. The method will be applicable to other dammalene glycosides regardless of their chemical structure. 4) The author and his co-workers converted chemically betulafolienetriol, a triterpene component of Betula platyphylla, to the protopanaxadiol, one of genuine aglycone of dammalene glycosides.

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Predicting Migration of a Heavy Metal in a Sandy Soil Using Time Domain Reflectometry (TDR을 이용한 사질토양에서의 중금속 이동 추정)

  • Dong-Ju Kim;Doo-Sung Baek;Min-Soo Park
    • Journal of Korea Soil Environment Society
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    • v.4 no.1
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    • pp.109-118
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    • 1999
  • Recently, transport parameters of conservative solutes such as KCl in a porous medium have been successfully determined using time domain reflectometry (TDR) . This study was initiated to Investigate the applicability of TDR technique to monitoring the fate of a heavy metal ion in a sandy soil and the distribution of its concentration along travel distance with time. A column test was conducted in a laboratory that consists of monitoring both resident and flux concentrations of $ZnCl_2$in a sandy soil under a breakthrough condition. A tracer of $ZnCl_2$(10 g/L) was injected onto the top surface of the sample as pulse type as soon as a steady-state condition was achieved. Time-series measurements of resistance and electrical conductivity were performed at 10 cm and 20 cm of distances from the inlet boundary by horizontal-positioning of parallel TDR metallic rods and using an EC-meter for the effluent exiting the bottom boundary respectively. In addition. Zn ions of the effluent were analyzed by ICP-AES. Since the mode and position of concentration detected by TDR and effluent were different, comparison between ICP analysis and TDR-detected concentration was made by predicting flux concentration using CDE model accommodating a decay constant with the transport parameters obtained from the resident concentrations. The experimental results showed that the resident concentration resulted in earlier and higher peak than the flux concentration obtained by EC-meter, implying the homogeneity of the packed sandy soil. A close agreement was found between the predicted from the transport parameters obtained by TDR and the measured $ZnCl_2$concentration. This indicates that TDR technique can also be applied to monitoring heavy metal concentrations in the soil once that a decay constant is obtained for a given soil.

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Accuracy of F-18 FDG PET/CT in Preoperative Assessment of Cervical Lymph Nodes in Head and Neck Squamous Cell Cancer: Comparison with CT/MRI (두경부 편평상피암 환자에서 수술 전 경부림프절 전이 평가에 대한 F-18 FDG PET/CT의 정확도: CT/MRI와의 비교)

  • Choi, Seung-Jin;Byun, Sung-Su;Park, Sun-Won;Kim, Young-Mo;Hyun, In-Young
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.6
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    • pp.309-315
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    • 2006
  • Purpose: Accurate evaluation of cervical lymph node (LN) metastasis of head and neck squamous cell canter (SCC) is important to treatment planning. We evaluated the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the detection of cervical LN metastasis of head and neck SCC and performed a retrospective comparison with CT/MRI findings. Materials & Methods: Seventeen patients with pathologically proven head and neck SCC underwent F-18 FDG PET/CT and CT/MRI within 4 week before surgery. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. F-18 FDG PET/CT images were analyzed visually for assessment of regional tracer uptake in LN. We analyzed the differences in sensitivity and specificity between F-18 FDG PET/CT and CT/MRI using the Chi-square test. Results: Among the 17 patients, a total of 123 LN levels were dissected, 29 of which showed metastatic involvement. The sensitivity and specificity of F-18 FDG PET/CT for detecting cervical LN metastasis on a level-by-level basis were 69% (20/29) and 99% (93/94). The sensitivity and specificity of CT/MRI were 62% (18/29) and 96% (90/94). There was no significant difference in diagnostic accuracy between F-18 FDG PET/CT and CT/MRI. Interestingly, F-18 FDG PET/CT detected double primary tumor (hepatocellular carcinoma) and rib metastasis, respectively. Conclusion: There was not statistically significant difference of diagnostic accuracy between F-18 FDG PET/CT and CT/MRI for the detection of cervical LN metastasis of head and neck SCC. The low sensitivity of F-18 FDG PET/CT was due to limited resolution for small metastatic deposits.

Water Flow Distribution and Sedimentation Characteristics of Particle Materials in the Sihwa Constructed Wetland (시화호 인공습지의 물흐름 분포 및 입자성물질 퇴적 특성)

  • Choi, Dong-Ho;Choi, Kwang-Soon;Kim, Sea-Won;Oh, Young-Taek;Kim, Dong-Sup;Joh, Seong-Ju;Park, Je-Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.4
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    • pp.425-437
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    • 2007
  • Flow distribution of water and sedimentation rate were investigated to understand the hydrodynamics and settling characteristics of particulate materials in a constructed wetland for treatment of non-point sources pollutants, the Sihwa constructed wetland, Korea. The Sihwa constructed wetland is divided into three sub-wetlands(the Banwol, the Donghwa and the Samhwa wetlands) to treat the polluted water from three streams, the Banwol stream, the Donghwa stream and the Samhwa stream. From the results of water flow experiment using dye(Rhodamine 50WT Red), it was found that the water flow in the wetland was prevailing at the waterway and open water. Dye was spread slowly in the closed water area planted by plants. The mean hydraulic retention time(HRT) at the upper area of high wetland and lower wetland of Banwol, was found to be 34.1 hr at the upper area and 74.6 hr at the lower area respectively, totaling approximately 108.7 hr(4.5 days). The sedimentation rate was higher at lower area(sites of B, C and D) of the wetland than upper area(site of A which is settling zone). Based on the forecast for 20 years as to the amount of sediment that can be deposited in the open water in the future, the sediment depth of each area would be like this: A: 6.3 cm, B: 8.3 cm, C: 7.0 cm, D: 9.5 cm. The contents of organic materials in the sediment deposited within the sediment trap were found to be higher overly in the first investigation period which had much rainfall, and B, C and D areas were found to have an increased COD accumulation than A area. Also, nitrogen and phosphorus were found to increase in the down-stream of the wetland. The results of this study suggest that a sustainable research and management for the characteristics of water flow pattern and sedimentation changeable as time passes is needs to maintain or improve the efficiency of water treatment in the constructed wetland.

Analysis of $^{99m}Tc-ECD$ Brain SPECT images in Boys and Girls ADHD using Statistical Parametric Mapping(SPM) (통계적 파라미터지도 작성법(SPM)을 이용한 남여별 ADHD환자의 뇌 SPECT 영상비교분석)

  • Park, Soung-Ock;Kwon, Soo-Il
    • Journal of radiological science and technology
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    • v.27 no.3
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    • pp.31-41
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    • 2004
  • Attention deficit hyperactivity disorder(ADHD)is one of the most common psychiatric disorders in childhood, especially school age children and persisting into adult. ADHD is affected 7.6% in our children, Korea. and persisting into $15{\sim}20%$ in adult. And it is characterized by hyperactivity, inattention and impulsivity. Brain imaging is one of way to diagnosis for ADHD. Brain imaging studies may be provide information two types - structural and functional imaging. Structural and functional images of the brain play an important role in management of neurologic and psyciatric disorders. Brain SPECT, with perfusion imaging radiopharmaceuticals is one of the appropriate test to diagnosis of neurologic and psychiatric diseases. Ther are a few studies about separated analysis between boys and girls ADHD SPECT brain images. Selection of Probability level(P-value) is very important to determind the abnormalities when analysis a data by SPM. SPM is a statistical method used for image analysis and determine statistical different between two groups-normal and ADHD. Commonly used P-value is P<0.05 in statistical analysis. The purpose of this study is to evaluation of blood flow clusters distribution, between boys and girls ADHD. The number of normal boys are 8(6-7y, average : $9.6{\pm}3.9y$) and 51(4-11y, average : $9.0{\pm}2.4$) ADHD patients, and normal girls are 4(6-12y, average : $9{\pm}2.4y$) and 13(2-13y, average $10{\pm}3.5y$) ADHD patiens. Blood flow tracer $^{99m}Tc-ethylcysteinate$ dimer(ECD) injected as rCBF agent and take blood flow images after 30 min. during sleeping by SPECT camera. The anatomical region of hyperperfusion of rCBF in boys ADHD group is posterior cingulate gyrus and hyperperfusion rate is 15.39-15.77% according to p-value. And girls ADHD group appears at posterior cerebellum, Lt. cerbral limbic lobe and Lt. Rt. cerebral temporal lobe. These areas hyperperfusion rate are 24.68-31.25%. Hypoperfusion areas in boys ADHD,s brain are Lt. cerebral insular gyrus, Lt. Rt. frontal lobe and mid-prefrontal lobe, these areas decresed blood flow as 15.21-15.64%. Girls ADHD decreased blood flow regions are Lt. cerebral insular gyrus, Lt. cerebral frontal and temporal lobe, Lt. Rt. lentiform nucleus and Lt. parietal lobe. And hypoperfusion rate is 30.57-30.85% in girls ADHD. The girls ADHD group's perfusion rate is more variable than boys. The studies about rCBF in ADHD, should be separate with boys and girls.

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Correlation of Soil Particle Distribution and Hydrodynamic Dispersion Mechanism in Ununiformed Soils Through Laboratory Column Tests (실내주상실험에 의한 불균일한 토양의 입도와 수리분산기작의 상관성 연구)

  • Kang, Dong-Hwan;Chung, Sang-Yong
    • Journal of Soil and Groundwater Environment
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    • v.11 no.6
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    • pp.28-34
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    • 2006
  • Laboratory column tests using $Cl^-$ tracer were conducted to study the correlation of soil particle distribution and hydrodynamic dispersion mechanism with three kinds of ununiformed soil samples, in which the ratio of gravel and sand versus silt and clay is 24.5 for S-1 soil, 4.48 for S-2 soil, and 0.4 for S-3 soil. Chloride breakthrough curves with time were fitted with gaussian functions. The relative concentrations of chloride were converged to 1.0 after 0.7 hours for S-1, 6.3 hours for S-2, and 389 hours for S-3. Average linear velocity, longitudinal dispersion coefficient, and longitudinal dispersivity were calculated by chloride breakthrough curves. Longitudinal dispersion coefficients were $1.20{\times}10^{-4}\;m^2/sec$ for S-1, $8.87{\times}10^{-7}\;m^2/sec$ for S-2, and $1.94{\times}10^{-9}\;m^2/sec$ for S-3. Peclet numbers calculated by the molecular diffusion coefficient of chloride and the mean grain diameters of soils were $2.59{\times}10^2$ for S-1, $6.27{\times}10^0$ for S-2, and $1.35{\times}10^{-4}$ for S-3. Mechanical dispersion was dominant for the hydrodynamic dispersion mechanism of S-1. Both mechanical dispersion and molecular diffusion were dominant for the hydrodynamic dispersion mechanism of S-2, but mechanical dispersion was ascendant over molecular diffusion. Hydrodynamic dispersion in S-3 was occurred mainly by molecular diffusion. When plotting three soils on the graph of $D_L/D_m$ versus Peclet number produced by Bijeljic and Blunt (2006), the values of $D_L/D_m$ for S-1 and S-2 were more than 2.0 order compared to their graph. S-3 was not plotted on their graph because the Peclet number was as small as $1.35{\times}10^{-4}$.