• Title/Summary/Keyword: Rock stress

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Geological Characteristics of Extra Heavy Oil Reservoirs in Venezuela (베네주엘라 초중질유 저류층 지질 특성)

  • Kim, Dae-Suk;Kwon, Yi-Kyun;Chang, Chan-Dong
    • Economic and Environmental Geology
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    • v.44 no.1
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    • pp.83-94
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    • 2011
  • Extra heavy oil reservoirs are distributed over the world but most of them is deposited in the northern part of the Orinoco River in Venezuela, in the area of 5,500 $km^2$, This region, which has been commonly called "the Orinoco Oil Belt", contains estimated 1.3 trillion barrels of original oil-in-place and 250 billion barrels of established reserves. The Venezuela extra heavy oil has an API gravity of less than 10 degree and in situ viscosity of 5,000 cP at reservoir condition. Although the presence of extra heavy oil in the Orinoco Oil Belt has been initially reported in the 1930's, the commercial development using in situ cold production started in the 1990's. The Orinoco heavy oil deposits are clustered into 4 development areas, Boyaco, Junin, Ayachoco, and Carabobo respectively, and they are subdivided into totally 31 production blocks. Nowadays, PDVSA (Petr$\'{o}$leos de Venzuela, S.A.) makes a development of each production block with the international oil companies from more than 20 countries forming a international joint-venture company. The Eastern Venezuela Basin, the Orinoco Oil Belt is included in, is one of the major oil-bearing sedimentary basins in Venezuela and is first formed as a passive margin basin by the Jurassic tectonic plate motion. The major source rock of heavy oil is the late Cretaceous calcareous shale in the central Eastern Venezuela Basin. Hydrocarbon materials migrated an average of 150 km up dip to the southern margin of the basin. During the migration, lighter fractions in the hydrocarbon were removed by biodegradation and the oil changed into heavy and/or extra heavy oil. Miocene Oficina Formation, the main extra heavy oil reservoir, is the unconsolidated sand and shale alternation formed in fluvial-estuarine environment and also has irregularly a large number of the Cenozoic faults induced by basin subsidence and tectonics. Because Oficina Formation has not only complex lithology distribution but also irregular geology structure, geological evolution and characteristics of the reservoirs have to be determined for economical production well design and effective oil recovery. This study introduces geological formation and evolution of the Venezuela extra heavy oil reservoirs and suggest their significant geological characteristics which are (1) thickness and geometry of reservoir pay sands, (2) continuity and thickness of mud beds, (3) geometry of faults, (4) depth and geothermal character of reservoir, (5) in-situ stress field of reservoir, and (6) chemical composition of extra heavy oil. Newly developed exploration techniques, such as 3-D seismic survey and LWD (logging while drilling), can be expected as powerful methods to recognize the geological reservoir characteristics in the Orinoco Oil Belt.

Induction of Autophagy by Low Dose of Cisplatin in H460 Lung Cancer Cells (폐암세포주에서 저용량 시스플라틴에 의해 유도된 자가포식)

  • Shin, Jeong-Hyun;Jang, Hye-Yeon;Chung, Jin-Soo;Cho, Kyung-Hwa;Hwang, Ki-Eun;Kim, So-Young;Kim, Hui-Jung;Lee, Sam-Youn;Lee, Mi-Kung;Park, Soon-Ah;Moon, Sun-Rock;Lee, Kang-Kyu;Jo, Hyang-Jeong;Yang, Sei-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.1
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    • pp.16-23
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    • 2010
  • Background: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung cancer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells. Methods: H460 cells were incubated with RPMI 1640 and treated in $5{\mu}M$ or $20{\mu}M$ cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy. Results: Lung cancer cells treated with $5{\mu}M$ cisplatin-treated were less sensitive to cell death than $20{\mu}M$ cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at $5{\mu}M$ was not detected, even though it was discovered at $20{\mu}M$. Poly (ADP-ribose) polymerase cleavages were not detected in $5{\mu}M$ within 24 hours. Massive vacuolization in the cytoplasm of $5{\mu}M$ treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in $5{\mu}M$ treated cells, but was not detected in $20{\mu}M$ treated cells. The expression of GFP-LC3 were increased in $5{\mu}M$ treated cells in a time-dependent manner. Conclusion: The induction of autophagy occurred in $5{\mu}M$ dose of cisplatin-treated lung cancer cells.

Growth of Minuartia laricina, Arenaria juncea, and Corydalis speciose in Field with Various Soil Water Contents (토양 수분 함량에 따른 너도개미자리, 벼룩이울타리, 산괴불주머니의 노지 생육)

  • Gil, Min;Kwon, Hyuck Hwan;Kwon, Young Hyun;Jung, Mi Jin;Kim, Sang Yong;Rhie, Yong Ha
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.344-353
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    • 2020
  • Plants native in Korea have not only ornamental values but also have excellent environmental adaptability, so they can be used as garden plants. Studies on proper volumetric water content (VWC) of substrates have been reported, but many have been conducted in glasshouse conditions where environmental factors were controlled. When considering garden planting, it is necessary to perform the automated irrigation system in outdoor conditions where rainfall occurs at frequent intervals. This research aimed to investigate the VWC suitable for the growth of Minuartia laricina, Arenaria juncea, and Corydalis speciosa in open filed. Sandy soil which consisted of particles of weathered rock was used, and the VWC of 0.15, 0.20, 0.25, and 0.30 ㎥·m-3 was maintained using an automated irrigation system with capacitance soil moisture sensors and a data logger. No significant differences in growth and antioxidant enzymes activity of A. juncea were observed among VWC treatments. However, the survival rate was low at VWC 0.30 ㎥·m-3 treatment, which was the highest soil moisture content. Even considering the efficiency of water use, we recommended that VWC 0.15-0.20 ㎥·m-3 is suitable for the cultivation of A. juncea. Minuartia laricina showed better growth with lower VWC. Because of frequent rainfall in open field, plant volume and survival rate was high even in VWC 0.15 ㎥·m-3 treatment. In C. speciosa, the plant height, number of shoots and lateral shoots, and fresh and dry weight were higher in plants grown in VWC 0.25 ㎥·m-3 as compared with that in the plants grown at 0.15, 0.20, and 0.30 ㎥·m-3. Based on these results, M. laricina needed less water in open filed, and A. juncea and C. speciosa required higher VWC, but excessive water should be avoided.

Application of the Homogenization Analysis to Calculation of a Permeability Coefficient (투수계수 산정을 위한 균질화 해석법의 적응)

  • 채병곤
    • Journal of Soil and Groundwater Environment
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    • v.9 no.1
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    • pp.79-86
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    • 2004
  • Hydraulic conductivity along rock fracture is mainly dependent on fracture geometries such as orientation, aperture, roughness and connectivity. Therefore, it needs to consider fracture geometries sufficiently on a fracture model for a numerical analysis to calculate permeability coefficient in a fracture. This study performed new type of numerical analysis using a homogenization analysis method to calculate permeability coefficient accurately along single fractures with several fracture models that were considered fracture geometries as much as possible. First of all, fracture roughness and aperture variation due to normal stress applied on a fracture were directly measured under a confocal laser scaning microscope (CLSM). The acquired geometric data were used as input data to construct fracture models for the homogenization analysis (HA). Using the constructed fracture models, the homogenization analysis method can compute permeability coefficient with consideration of material properties both in microscale and in macroscale. The HA is a new type of perturbation theory developed to characterize the behavior of a micro inhomogeneous material with a periodic microstructure. It calculates micro scale permeability coefficient at homogeneous microscale, and then, computes a homogenized permeability coefficient (C-permeability coefficient) at macro scale. Therefore, it is possible to analyze accurate characteristics of permeability reflected with local effect of facture geometry. Several computations of the HA were conducted to prove validity of the HA results compared with the empirical equations of permeability in the previous studies using the constructed 2-D fracture models. The model can be classified into a parallel plate model that has fracture roughness and identical aperture along a fracture. According to the computation results, the conventional C-permeability coefficients have values in the range of the same order or difference of one order from the permeability coefficients calculated by an empirical equation. It means that the HA result is valid to calculate permeability coefficient along a fracture. However, it should be noted that C-permeability coefficient is more accurate result than the preexisting equations of permeability calculation, because the HA considers permeability characteristics of locally inhomogeneous fracture geometries and material properties both in microscale and macroscale.

Seasoning of Commercial Wood Using Solar Energy (태양에너지를 이용한 유용목재의 건조)

  • Jung, Hee-Suk;Lee, Hyoung-Woo;Lee, Nam-Ho;Lee, Sang-Bong
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.4
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    • pp.10-39
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    • 1988
  • This study investigated the temperatures and relative humidities in the semi-greenhouse type solar dryer with a black rock-bed heat storage and without heat storage and outdoor temperature and relative humidity at 9 a.m. and 2 p.m.. A comparison was made of the drying rates, final moisture contents, moisture content distributions, casehardening stresses, drying defects, volumetric shrinkage of dried lumber for solar- and air-drying from the green condition of mixtures of Douglas-fir, lauan, taun, oak and sycamore 25mm- and 50 mm-thick lumber during the same period for four seasons, and heat efficiencies for solar dryer with and without the heat storage for saving of heat energy and the cost of lumber drying using the solar energy. The results from this study were summarized as follows: I. The mean weekly temperatures in the solar dryers were 3 to $6^{\circ}C$ at 9 a.m. and 9 to $13^{\circ}C$ at 2 p.m. higher than mean outdoor temperature during all the drying period. 2. The mean weekly relative humidities in the solar dryers were about 1 to 19% at 9 a.m. higher than the outdoor relative humidity. and the difference between indoor and outdoor relative humidity in the morning was greater than in the afternoon. 3. The temperatures and relative humidities in the solar dryer with and without the heat storage were nearly same. 4. The overall solar insolation during the spring months was highest and then was greater in the order of summer, atumm, and winter month. S. The initial rate of solar drying was more rapid than that of air drying. As moisture content decreased, solar drying rate became more rapid than that of air drying. The rates of solar drying with and without heat storage were nearly same. The drying rate of Douglas-fir was fastest and then faster in the order of sycamore, lauan, taun and oak. and the faster drying rate of species, the smaller differences of drying rates between thicknesses of lumber. The drying rates were fastest in the summer and slowest in the winter. The rates of solar drying during the spring were more slowly in the early stage and faster in the later stage than those during the autumn. 6. The final moisture contents were above 15% for 25mm-thick air dried and about 10% for solar dried lumber, but the mean final MCs for 50mm-thick lumber were much higher than those of thin lumber. The differences of final MC between upper and lower course of pile for solar drying were greater than those of pile for air drying. The differences of moisture content between the shell and the core of air dried lumbers were greater than those of solar dried lumber, smallest in the drying during summer and greatest in the drying during winter among seasons. 7. Casehardening stresses of 25mm- and 50mm-thick dried lumber were slight, casehardening stress of solar dried lumber was severer than that of air dried lumber and was similar between solar dried lumber with and without heat storage, Casehardening stresses of lumber dried during spring were slightest and then slighter in the order of summer, autumn, and winter. Casehardening stresses of Douglas -fir, sycamore and lauan were slight, comparing with those of taun and oak. 8. Maximum initial checks of 25mm-thick lumber occurred above and below fiber saturation point and those of 50mm-thick lumber occurred in the higher moisture content than thin lumber. As the moisture content decreased, most of checks were closed and didn't show distinct difference of the degree of checks among drying methods. The degree of checks were very slight in case of Douglas-fir and lauan, and severe in case of taun and oak. The degree of checks for 50mm-thick lumber were severer than those for 25mm-thick lumber. 9. The degree of warpage showed severe in case of oak and sycamore lumber, but no warping was found in case of Douglas-fir, lauan and taun. 10. The volumetric shrinkages of taun and oak were large and medium in case of Douglas-fir, lauan and sycamore. 11. Heat efficiencies of solar dryer with heat storage were 6.9% during spring, 7.7% during summer, 12.1% during autumn and 4.1% during winter season. Heat efficiency of solar dryer with heat storage was slightly greater than that of without heat storage. As moisture content of lumber decreased, heat efficiency decreased.

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Effects of Minerals Added to Medicinal Plant Extracts on Alcohol-Induced Oxidative Stress and Alcohol Metabolism in Rats (약용식물 추출물이 첨가된 미네랄이 알코올에 의한 산화적 스트레스 및 숙취해소에 미치는 효과)

  • Lee, Seok-Jun;Kim, Andre;Lee, Jae-Hwa;Kim, Mee-Hee;Lee, Bong-Sang;Jee, Young-Taek;Bin, Jae-Hun;Ha, Jong-Myung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.393-400
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    • 2011
  • This study investigates the effects of a hangover beverage (MIX) that contains minerals (highly-salty mineral water, HSMW) and several medicinal plant extracts, on antioxidant and alcohol-metabolizing enzymes in alcohol administered Sprague-Dawley rats. HSMW is pumped from below the sedimentary rock layer of Dadaepo, Busan, South Korea, which is 1,050 m below the land surface; it tastes salty, like sea water. In terms of medicinal plant extracts, the total phenolic and flavonoid contents of Rubus coreanus and Cornus officinalis were measured as being significantly higher than those in Curcuma longa. The results suggest that treatment with MIX significantly increases superoxide dismutase (SOD) activity and DPPH radical scavenging activity. In the 10% HSMW-, for MIX- and company product (CP)-treated groups, the concentration of blood alcohol was significantly reduced 1~5 hr after alcohol loading, compared to that in the control group. In hepatic alcohol-metabolizing enzyme activities, alcohol dehydrogenase (ADH) activity was found to be higher in the MIX- and CP-treated groups than in controls, whereas acetaldehyde dehydrogenase (ALDH) activity was significantly higher in the CP-treated groups than other groups. This study concludes, therefore, that MIX (HSMW) minerals, like as Zn, Ca, Mg, Mn, and others stimulate alcohol-metabolizing enzymes, while the antioxidants of plant extracts prevent the damage otherwise incurred by alcohol toxicity. These results suggest that the hangover beverage (MIX) alleviates alcohol hangover symptoms by stimulating activities related to hepatic alcohol-metabolizing enzymes and antioxidant effects.

Relationship between Earthquake and Fluctuation of Water Level in Active Fault Zone and National Groundwater Monitoring Wells of Gyeongju Area (경주 활성단층대 및 주변 국가지하수 관측정에서 지진과 수위변동 상관관계 연구)

  • Jang, Hyeon-Woo;Jeong, Chan-Ho;Lee, Yong-Cheon;Lee, Yu-Jin;Hong, Jin-Woo;Kim, Cheon-Hwan;Kim, Young-Seog;Kang, Tae-Seob
    • The Journal of Engineering Geology
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    • v.30 no.4
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    • pp.617-634
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    • 2020
  • The purpose of this study is to investigate the relationship of between earthquakes and fluctuation of water level in a groundwater well of the active-fault zone and 124 national groundwater monitoring wells in Gyeongju area. The spatial and temporal relationships between the fluctuation of water level and the earthquake were analyzed by the calculation of earthquake effectiveness (ε) and q-factor which are the function of earthquake magnitude and distance from epicenter. Two earthquake events of E1 (April 22, 2019, M 3.8) and E2 (June 11, 2019, M 2.5) show a close relationship with a post-seismic 83 cm decrease and a pre-seismic 76 cm increase in water level at the active fault zone of Dangu-ri, respectively. The spatial analysis of water level fluctuation data in National Groundwater Monitoring Networks caused by earthquake events shows a more distinct response in deep groundwater around fault zones than other area, and a greater change in deep groundwater than shallow groundwater. It's inferred that the decrease and increase in groundwater level are affected by the expansion of fractures and compression of rock mass due to seismic stress, respectively. The effective ranges of ε-value and q-factor of the monitoring well in Dangu-ri were calculated as 2.70E-10~5.60E-10 and 14.4~18.0, respectively.

A study on the field tests and development of quantitative two-dimensional numerical analysis method for evaluation of effects of umbrella arch method (UAM 효과 평가를 위한 현장실험 및 정량적 2차원 수치해석기법 개발에 관한 연구)

  • Kim, Dae-Young;Lee, Hong-Sung;Chun, Byung-Sik;Jung, Jong-Ju
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.1
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    • pp.57-70
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    • 2009
  • Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.