• Title/Summary/Keyword: pore analysis

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Development and Its Application of a Discrete Fracture Flow Model for the Analysis of Gas-Water Transient Flow in Fractured Rock Masses Around Storage Cavern (지하저장공동 주변 불연속 암반에서의 가스-물 천이유동해석을 위한 개별균열 유동모델의 개발 및 응용)

  • 나승훈;성원모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.705-712
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    • 2000
  • The fluid generally flows through fractures in crystalline rocks where most of underground storage facilities are constructed because of their low hydraulic conductivities. The fractured rock is better to be conceptualized with a discrete fracture concept, rather continuum approach. In the aspect of fluid flow in underground, the simultaneous flow of groundwater and gas should be considered in the cases of generation and leakage of gas in nuclear waste disposal facilities, air sparging process and soil vapor extraction for eliminating contaminants in soil or rock pore, and pneumatic fracturing for the improvement of permeability of rock mass. For the purpose of appropriate analysis of groundwater-gas flow, this study presents an unsteady-state multi-phase FEM fracture network simulator. Numerical simulation has been also conducted to investigate the hydraulic head distribution and air tightness around Ulsan LPG storage cavern. The recorded hydraulic head at the observation well Y was -5 to -10 m. From the results obtained by the developed model, it shows that the discrete fracture model yielded hydraulic head of -10 m, whereas great discrepancy with the field data was observed in the case of equivalent continuum modeling. The air tightness of individual fractures around cavern was examined according to two different operating pressures and as a result, only several numbers of fractures neighboring the cavern did not satisfy the criteria of air tightness at 882 kPa of cavern pressure. In the meantime, when operating pressure is 710.5 kPa, the most areas did not satisfy air tightness criteria. Finally, in the case of gas leaking from cavern to the surrounding rocks, the resulted hydraulic head and flowing pattern was changed and, therefore, gas was leaked out from the cavern ceiling and groundwater was flowed into the cavern through the walls.

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Morphology and Molecular Phylogeny of Raillietina spp. (Cestoda: Cyclophyllidea: Davaineidae) from Domestic Chickens in Thailand

  • Butboonchoo, Preeyaporn;Wongsawad, Chalobol;Rojanapaibul, Amnat;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.54 no.6
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    • pp.777-786
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    • 2016
  • Raillietina species are prevalent in domestic chickens (Gallus gallus domesticus) in Phayao province, northern Thailand. Their infection may cause disease and death, which affects the public health and economic situation in chicken farms. The identification of Raillietina has been based on morphology and molecular analysis. In this study, morphological observations using light (LM) and scanning electron microscopies (SEM) coupled with molecular analysis of the internal transcribed spacer 2 (ITS2) region and the nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) gene were employed for precise identification and phylogenetic relationship studies of Raillietina spp. Four Raillietina species, including R. echinobothrida, R. tetragona, R. cesticillus, and Raillietina sp., were recovered in domestic chickens from 4 districts in Phayao province, Thailand. LM and SEM observations revealed differences in the morphology of the scolex, position of the genital pore, number of eggs per egg capsule, and rostellar opening surface structures in all 4 species. Phylogenetic relationships were found among the phylogenetic trees obtained by the maximum likelihood and distance-based neighbor-joining methods. ITS2 and ND1 sequence data recorded from Raillietina sp. appeared to be monophyletic. The query sequences of R. echinobothrida, R. tetragona, R. cesticillus, and Raillietina sp. were separated according to the different morphological characters. This study confirmed that morphological studies combined with molecular analyses can differentiate related species within the genus Raillietina in Thailand.

Analysis of the Important Herb Medications Corresponded with Neuropsychiatry of "Bang-Yak-Hap-Pyun" (방약합편(方藥合編)에 수재된 신경정신과(神經精神科) 관련 주요 처방(處方)에 대한 연구(硏究))

  • Kim, Jee-Hoon;Koo, Byung-Soo;Kim, Geun-Woo
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.1
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    • pp.89-106
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    • 2009
  • Objectives : The purpose of this study is to analysis of the herb medications corresponded with neuropsychiatry of "Bang-Yak-Hap-Pyun". Methods : The herb medications of "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong(上.中.下統) and "Enlargement side prescriptions" (增補方) are selected by comment on the chief virtue including reference word of corresponded with neuropsychiatry. Results and Conclusion : "Bang-Yak-Hap-Pyun" is a book most people who have a background or career in Han Medicine(韓醫學) would pore over. They corresponded with neuropsychiatry among the herb medications of "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong(上.中.下統) are 55 prescriptions that Sang-Tong(上統) is 8 prescriptions, Jung-Tong(中.統) is 23 prescriptions and Ha-Tong(下統) is 24 prescriptions. And the herb medications corresponded with neuropsychiatry of "Enlargement side prescriptions" (增補方) are 40 prescriptions. And then the herb medications corresponded with neuropsychiatry of "Bang-Yak-Hap-Pyun" received much influence from "Dong-Eui-Bo-Gam". Incidentally the herb medications corresponded with neuropsychiatry of "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong showed the high percentage in Neurosis. And the herb medications corresponded with neuropsychiatry of "Enlargement side prescriptions" showed the high percentage in Psychosis. Besides not only put "Enlargement side prescriptions a premium on "Dong-Eui-Bo-Gam", but also made it the herb medications which were recorded on books flowed after "Dong-Eui-Bo-Gam" known. It was entered up books quoted from "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong but the herb medications were that were not succeeded from "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong. Therefore "Enlargement side prescriptions" shows the efforts for supplement of "Bang-Yak-Hap-Pyun" Sang.Jung.Ha-Tong.

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A Study on Discharge Capacity of Vertical Drain Considering with In-situ Soil Condition (원지반조건을 고려한 연직배수재의 통수능에 관한 연구)

  • Park, Min-Chul;Kim, Eun-Chul;Lee, Song
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.1
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    • pp.47-56
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    • 2012
  • Discharge capacity of PBD is sensitive in proportion to thickness and ground condition, and drainage of PBD declines due to disturbance effect in surrounding ground by mandrel used for vertical drainage setting and setting machines and type. Also, deviation of discharge capacity gets larger according to ground condition, construction condition and soil properties. But cause and analysis of those problems like reduced discharge of capacity and delayed dissipation of pore water pressure for discharge capacity is lack. Thus, in this text, ground improvement and discharge capacity is investigated by implementing composite discharge capacity test for analysis of an effect factor of PBD discharge capacity with in-situ ground condition. After fixing the vertical drain on a cylindrical cylinder, put churned sample into the cylinder. After in-situ ground and reclamation of ground are dredged, load following the loading step of 30, 70 and 120kPa using a pressure device. Result of the test, The discharge capacity was SM>ML>CL>CL(dredged soil) in situ condition and more fine-grained content, the amount of discharge was greater.

Structure and Property Analysis of Nanoporous Low Dielectric Constant SiCOH Thin Films

  • Heo, Gyu-Yong;Lee, Mun-Ho;Lee, Si-U;Park, Yeong-Hui
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2009.05a
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    • pp.167-169
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    • 2009
  • We have carried out quantitative structure and property analysis of the nanoporous structures of low dielectric constant (low-k) carbon-doped silicon oxide (SiCOH) films, which were deposited with plasma enhanced chemical vapor deposition (PECVD) using vinyltrimethylsilane (VTMS), divinyldimethylsilane (DVDMS), and tetravinylsilane (TVS) as precursor and oxygen as an oxidant gas. We found that the SiCOH film using VTMS only showed well defined spherical nanopores within the film after thermal annealing at $450^{\circ}C$ for 4 h. The average pore radius of the generated nanopores within VTMS SiCOH film was 1.21 nm with narrow size distribution of 0.2. It was noted that thermally labile $C_{x}H_{y}$ phase and Si-$CH_3$ was removed to make nanopore within the film by thermal annealing. Consequently, this induced that decrease of average electron density from 387 to $321\;nm^{-3}$ with increasing annealing temperature up to $450^{\circ}C$ and taking a longer annealing time up to 4 h. However, the other SiCOH films showed featureless scattering profiles irrespective of annealing conditions and the decreases of electron density were smaller than VTMS SiCOH film. Because, with more vinyl groups are introduced in original precursor molecule, films contain more organic phase with less volatile characteristic due to the crosslinking of vinyl groups. Collectively, the presenting findings show that the organosilane containing vinyl group was quite effective to deposit SiCOH/$C_{x}H_{y}$ dual phase films, and post annealing has an important role on generation of pores with the SiCOH film.

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A Comparison Study on the Two Dimensional Consolidation Analysis Methods (2 차원(次元) 압밀해석법(壓密解析法)의 비교연구(比較研究))

  • Park, Byong Kee;Chung, Jin Sup;Park, Hae Kuen
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.39-47
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    • 1985
  • In this paper, a FEM analysis model was developed to solve the consolidation phenomena of embankment on the soft foundation. The developed FEM model was based on the Biot's consolidation equation which was coupled with one of three stress-strain constitutive relationships. In order to check the validity of the newly developed FEM model, the program input data were used by a test embankment which had been already constructed at Cubzac-les-ponts in France by Magnan et al. The FEM results compared to the experimental and analytical results which were obtained by the Magnan's group at Cubzac-les-ponts. The results compared showed that the consolidation phenomena were well explained by the author's FEM model which results were more accurate than the others. As for the pore water pressure, Christian-Boehmer's method used in this paper was considered preferable to Sandhu-Wilson's used by Magnan.

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A Study on the Simultaneous Oxidation of $CH_4$ and CO over $Pd/TiO_2$ Catalyst ($Pd/TiO_2$ 촉매를 이용한 $CH_4$, CO의 동시산화 연구)

  • Lee, Hyun Hee;Jang, Du Hun;Hong, Sung Chang
    • Applied Chemistry for Engineering
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    • v.23 no.3
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    • pp.253-258
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    • 2012
  • The effects of active sites and valence states were investigated over $Pd/TiO_2$ catalyst on simultaneous oxidation of $CH_4$ and CO. The Pd species (PdO) crystallite size increased with increasing Pd loadings, which results in enhancement of the activity of $CH_4$ oxidation. Different results from the activity of $CH_4$ and CO oxidation were shown to be dependent on the Pd valence state on the surface of the catalyst prepared through a thermal treatment. XRD and $H_2-TPR$ analysis confirmed that $Pd^{2+}$species was predominated in the calcination catalyst, while $Pd^0$species was predominated in the reduction catalyst. Additionally, it could be found that the valence state of Pd was a more important factor on the catalytic activity than that of factors as the surface area and pore volume. The reaction mechanism of $CH_4$ and CO followed by the valence state of Pd could be identified using FT-IR analysis.

Numerical Analysis of Light-weight Air Foamed Soils using Dredged Marine Clay for Soft Ground Improvement Method (준설점토 활용 경량혼합토의 연약지반개량공법 수치해석)

  • Yoon, Gillim;Kim, Sunbin
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.3
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    • pp.5-13
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    • 2014
  • This paper presents the results of a numerical investigation on applicability of Light-weighted Foam Soils (LWFS) consisted of dredged soils for soft ground improvement. The engineering properties of LWFS were comprehensively investigated based on the previous experimental tests. And three dimensional numerical models which reflect soft ground conditions were adopted to evaluate the applicability of LWFS compared to SCP and DCM. A number of cases were analyzed using a stress-pore pressure coupled model. The results indicated that LWFS method enables to reduce more settlement, lateral flow and heaving than SCP method and enable to reduce more residual settlement than DCM method. Also it was revealed that such effect depends on the properties of LWFS such as unit weight, unconfined compressive strength, deformation modulus and Poisson's ratio.

Numerical Analysis of Relief Well Effect for Seepage Control of Small Fill Dam (소규모 필댐의 침투수 관리를 위한 감압정 효과에 대한 수치해석)

  • Chang, Jaehoon;Yoo, Chanho;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.2
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    • pp.5-13
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    • 2020
  • The relief wells have been studied to be effective in seepage control in small dams such as agricultural dams. However, quantitative studies on the effects of the relief well are rare and there is no design standard also. To quantitatively analyze the effects of the seepage control in small dams, the research of up-lift pressure influencing the toe of dam body was conducted by seepage analysis, which investigates the behavior characteristics, according to the conditions of dam and foundation. The effect of seepage control was studied by analyzing the reduction effect of up-lift pressure at foundation ground of the toe of downstream dam slope depending on the installation of the relief well. As a result, it was found that the relief wells are effective in reducing the pore water pressure in the foundation, which can cause piping and sliding failure.

CERAMOGRAPHY ANALYSIS OF MOX FUEL RODS AFTER AN IRRADIATION TEST

  • Kim, Han-Soo;Jong, Chang-Yong;Lee, Byung-Ho;Oh, Jae-Yong;Koo, Yang-Hyun
    • Nuclear Engineering and Technology
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    • v.42 no.5
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    • pp.576-581
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    • 2010
  • KAERI (Korea Atomic Energy Research Institute) fabricated MOX (Mixed Oxide) fuel pellets as a cooperation project with PSI (Paul Scherrer Institut) for an irradiation test in the Halden reactor. The MOX pellets were fitted into fuel rods that included instrumentation for measurement in IFE (Institutt for Energiteknikk). The fuel rods were assembled into the test rig and irradiated in the Halden reactor up to 50 MWd/kgHM. The irradiated fuel rods were transported to the IFE, where ceramography was carried out. The fuel rods were cut transversely at the relatively higher burn-up locations and then the radial cross sections were observed. Micrographs were analyzed using an image analysis program and grain sizes along the radial direction were measured by the linear intercept method. Radial cracks in the irradiated MOX were observed that were generally circumferentially closed at the pellet periphery and open in the hot central region. A circumferential crack was formed along the boundary between the dark central and the outer regions. The inner surface of the cladding was covered with an oxide layer. Pu-rich spots were observed in the outer region of the fuel pellets. The spots were surrounded by many small pores and contained some big pores inside. Metallic fission product precipitates were observed mainly in the central region and in the inside of the Pu spots. The average areal fractions of the metallic precipitates at the radial cross section were 0.41% for rod 6 and 0.32% for rod 3. In the periphery, pore density smaller than 2 ${\mu}m$ was higher than that of the other regions. The grain growth occurred from 10 ${\mu}m$ to 12 ${\mu}m$ in the central region of rod 6 during irradiation.