• Journal of Pharmaceutical Investigation
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• 제30권2호
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• pp.99-105
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• 2000

This study compared the permeability of $[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ through the blood-brain barrier (BBB) in mice and rats with common carotid artery perfusion (CCAP) method that modified internal carotid artery perfusion (ICAP) method. External carotid artery (ECA) was cannulated with coagulating pterygopalatine artery (PPA) in ICAP method, while CCA was cannulated without coagulating PPA in CCAP method. Also, for evaluation of BBB permeability of drugs in mice and rats, we used intravenous injection technique. The results of CCAP method in mice at a perfusion flow-rate of 2 ml/min, the brian volume of distribution $(V_D)$ of $[^{14}C]sucrose,\;[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ were similar to the result of ICAP method in rats at perfusion flow rate of 4 ml/min. The area under the plasma concentration-time curve and brain uptake of $[^3H]taurine$ by intravenous injection technique, were $65.5{\pm}9.7%ID^*min/ml\;and\;0.515{\pm}0.093%ID/g$, respectively, in mice, and the corresponding values were $8.00{\pm}0.03%ID^*min/ml\;and\;0.052{\pm}0.003%ID/g$ in rats. But the BBB permeability surface-area product of $[^3H]taurine$ was similar between mice and rats. In conclusion, the CCAP method in mice was simple, fast and comparable to ICAP method in rats for drug permeability through the BBB.

• Geomechanics and Engineering
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• 제18권2호
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• pp.205-213
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• 2019

A calculation model of reservoir pressure field distribution around multiple production wells in a heavy oil reservoir is established, which can overcome the unreasonable uniform-pressure value calculated by the traditional mathematical model in the multiwell mining areas. A calculating program is developed based on the deduced equations by using Visual Basic computer language. Based on the proposed mathematical model, the effects of drainage rate and formation permeability on the distribution of reservoir pressure are studied. Results show that the reservoir pressure drops most at the wellbore. The farther the distance away from the borehole, the sparser the isobaric lines distribute. Increasing drainage rate results in decreasing reservoir pressure and bottom-hole pressure, especially the latter. The permeability has a significant effect on bottom hole pressure. The study provides a reference basis for studying the dynamic pressure field distribution before thermal recovery technology in heavy oilfield and optimizing construction parameters.

• 터널과지하공간
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• 제12권4호
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• pp.304-311
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• 2002

절리의 기하학적 특성이 절리의 수직변형 및 투수성에 미치는 영향에 대해 수치해석적 방법을 통해 연구하였다. 실험적 계측 결과에 의하면, 절리의 간극은 통계적 방법에 의해 묘사되며 이에 근거하여 수치해석에 사용할 수 있는 절리를 모사할 수 있었다. 이를 위해. 자동 상관관계 함수를 이용하여 다양한 공간 상관길이의 인공 절리를 발생하였으며, 이를 토대로 수직변천 모델 및 수리해석 모델을 개발하였다. 수직변형 모델은 수직응력에 의한 절리면의 압축과 변형을 고려하여 절리의 변형거동을 해석하려 시도하였으며, cubic law에 근거한 유한차분법을 이용하여 수리해석을 수행하였다. 여러 가지 공간 상관길이의 인공 절리에 대한 수직변형 거동 및 이에 따른 수리해석의 결과, 간극의 공간 상관길이가 증가함에 따라 절리의 수직변형 및 투수성 감소가 분명하였다. 절리의 수직강성 역시 간극의 상관길이에 영향을 받는 것으로 나타났으며, 이로 인해 절리의 투수성이 수직강성과 내재적 관계가 있음을 유추할 수 있겠다. 본 연구 결과는 공학적 프로젝트로 인한 절리 암반의 수리-역학적 거동을 이해하는데 공헌할 것으로 사료된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.511-512
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• 2007

• 한국농공학회:학술대회논문집
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• 한국농공학회 2004년도 학술발표논문집
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• pp.64-64
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• 2004

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2773-2784
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• 2023

It is essential to evaluate the blasting-enhanced permeability (BEP) feasibility of a low-permeability sandstone-type uranium deposit. In this work, the mineral composition, reservoir physical properties and rock mechanical properties of samples from sandstone-type uranium deposits were first measured. Then, the reformability evaluation method was established by the analytic hierarchy process-entropy weight method (AHP-EWM) and the fuzzy mathematics method. Finally, evaluation results were verified by the split Hopkinson Pressure Bar (SHPB) experiment and permeability test. Results show that medium sandstone, argillaceous sandstone and siltstone exhibit excellent reformability, followed by coarse sandstone and fine sandstone, while the reformability of sandy mudstone is poor and is not able to accept BEP reservoir stimulation. The permeability improvement and the distribution of damage fractures before and after the SHPB experiment confirm the correctness of evaluation results. This research provides a reformability evaluation method for the BEP of the low-permeability sandstone-type uranium deposit, which contributes to the selection of the appropriate regional and stratigraphic horizon of the BEP and the enhanced ISL of the low-permeability sandstone-type uranium deposit.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권3호
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• pp.42-49
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• 2017

TOUGH2 was used to simulate the migration of $CO_2$ injected into a sandy aquifer. A series of numerical simulations was performed to investigate the effects of a low-permeability layer (LPL) embedded in the aquifer on the injection rate and the pressure distribution of $CO_2$. The results show that the size and location of the LPL greatly affected the spread of $CO_2$. The pressure difference between two points in the aquifer, one each below and above the LPL, increased as the size of the LPL increased, showing a critical value at 200 m, above which the size effect was diminished. The location of the LPL with respect to the injection well also affected the migration of $CO_2$. When the injection well was at the center of the LPL, the injection rate of $CO_2$ decreased by 5.0% compared to the case with no LPL. However, when the injection well was at the edge of the LPL, the injection rate was decreased by only 1.6%. The vertical distance between the injection point and the LPL also affected the injection rate. The closer the LPL was to the injection point, the lower the injection rate was, by up to 8.3%. Conclusively, in planning geologic storage of $CO_2$, the optimal location of the injection well should be determined considering the distribution of the LPL in the aquifer.

• 지구물리와물리탐사
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• 제6권2호
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• pp.64-70
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• 2003

본 연구에서는 토목현장에서 필요로하는 여러 파라미터들 중에서 물리탐사가 제공할 수 있는 영역을 한걸음 더 넓히고자 투수계수 산출을 위한 새로운 접근을 시도하였다. 전기비저항과 투수계수의 상관관계를 밝히기 위한 현장시험 결과 전기비저항검층과 수압시험(Lugeon test)에 의한 전기비저항-투수계수는 log-log 그래프상에서 반비례 관계를 만족하였다. 양산지역의 화강암과 안산암의 경우 $log(k){\approx}-0.85621\;log({\rho})+0.0031$ 의 관계를 보였으며 측선 상에서 수행된 AMT (Audio-frequency Magneto-Telluric) 탐사 결과와 이 식을 이용하여 전기비저항 단면을 2차원 투수계수 분포단면으로 변환하고 이를 지하수 유동모델링의 입력자료로 제공하였다.

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.61-70
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• 2003

원심법을 이용하여 침엽수 생재 심재부의 조재와 만재에 대한 수분이동경로의 크기를 평가하였다. 또한, 원심처리 후의 포수율 분포와 수분포텐셜의 관계로부터 액체투과성을 측정하였다. 삼나무의 경우, 조재는 0.70 ㎛, 만재는 0.50 ㎛의 반경에서 뚜렷한 피크가 관찰되었다. 솔송나무는 조재와 만재 모두 0.50 ㎛의 반경에서 피크를 나타냈다. 일본전나무와 일본잎갈나무는 조재 0.70 ㎛, 만재 0.30 ㎛의 반경범위에서 피크 값이 관찰되었다. 반면에, 미송과 시트카스푸르수는 뚜렷한 피크 값을 보이지 않았다. 액체투과성은 미송을 제외한 모든 수종에서 조재가 만재보다 좋게 평가되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.609-612
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• 2001

To investigate the magnetic field distribution of power line, we used amorphous wire sensor. And we discuss extremely low frequency magnetic field distribution dependent upon arrangement of power line and shielding pipe made from iron or alumimum materials by both measurement and FEM(Finite Element Method) analysis. Appling current of single phase 60 [Hz] 15 [A] is supplied to copper wire coated enamel resign. As the results, we confirmed that linear characteristics of amorphous wire sensor is very excellent and measurement value agrees with FEM calculation. Magnetic field distribution due to shielding materials is changed by permeability and conductivity.