• 제목/요약/키워드: pore analysis

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Characteristics and microstructure of MCFC electrode (용융탄산염형 연료전지 전극의 미세구조와 특성)

  • 김귀열;엄승욱
    • Electrical & Electronic Materials
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    • v.8 no.5
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    • pp.544-550
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    • 1995
  • In this paper, the anode for molten carbonate fuel cell have been prepared by doctor blade method and microstructure, pore distribution, sintering test of the electrode were investigated. Component analysis were done by Scanning Electron Micrograph, porosimeter and sintering test apparatus. As a result, median pore size was 11.mu.m order at the major specimen and porosity was about 70%. And thickness loss of the electrode was 1.5% at Ni-10Co anode after sintering test.

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Modulus of Horizontal Subgrade Reaction in Liquefying Sand by Shaking Table Test (진동대 시험을 통한 액상화되는 지반의 수평지반반력계수에 대한 연구)

  • 박종관;한성길;김상규;이용도
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.255-262
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    • 2000
  • Shaking table tests were peformed to evaluate the subgrade reaction of ground according to the build-up of pore water pressure. Model pile was installed in the sand ground. The acceleration of the model ground, the pore water pressure build-up and displacement of pile were recorded by measuring devices. Subgrade reaction approach based on Winker soil model was applied to obtain the modulus of the horizontal subgrade reaction. The results of analysis show that the reduction factor of the subgrade reaction due to pore pressure increase is about 1 and the horizontal subgrade reaction of liquefied ground is not influenced by the stiffness of pile, a ground acceleration and the intial ground density.

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A study on the fabrication of CdS nanowires using by Alumina Membrane (알루미나 멤브레인을 이용한 CdS nanowire 제작에 관한 연구)

  • Seo, Mun-Su;Lee, Su-Ho;Yoo, Hyun-Min;Lee, Jae-Hyeong;Choi, Won-Seok;Kim, Do-Young
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1493-1494
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    • 2011
  • CdS nanostructure materials have been fabricated in porous anodic aluminum oxide (AAO) template by using chemical bath deposition (CBD). These nanostructure materials had uniform diameters of about 15e200 nm, which correspond to the pore sizes of the templates used, and the length was up to 40 mm. X-ray diffraction (XRD) investigation demonstrates that CdS nanostructure materials were hexagonal polycrystalline in nature. As the pore diameter of AAO templates was enlarged, the preferential orientation of c-axis was improved. From PL analysis, the sulfur-deficient defects at the surfaces of CdS nanostructure materials were increasedwhen the samplewas synthesized in the template with larger pore diameter.

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A Study on the Behavior of Cation in Cement Paste (시멘트 경화체내 양이온 거동에 관한 연구)

  • 윤성진;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.549-554
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    • 2001
  • It is possible for concrete using sea sand to contain chloride ion as well as cation such as Na$^{+}$and $K^{+}$ during mixing process. It is known that some cations such as Na$^{+}$and $K^{+}$ remain in pore solution without binding In this study, therefore, we intend to inspect the behavior of cations in cement paste as well as NaCl, CaCl$_2$ and KCI through analysis of pore solution extracted from cement paste with high pressure vessel. As a result, increase of alkali ions by adding sea sand and admixtures to the fresh concrete means use of the cement contained high alkali contents. In this case, alkali ions in pore solution can decrease durability of cement products causing alkali-aggregate reaction or accelerated carbonation. So it needs to be studied.studied.

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Preparation of Porous Glass by the Sintering (소결법에 의한 다공질유리의 제조)

  • 박용완;이준영
    • Journal of the Korean Ceramic Society
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    • v.31 no.9
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    • pp.957-968
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    • 1994
  • Manufacturing process of porous glass by the filler method was studied. Commercial soda-lime-silicate glass powder was mixed with inorganic salt as the filler such as KCl, K2SO4, Na2SO4. Sintering shrinkages of mixed powders with the variation of sintering temperature were compared, and the effects of the fillers to shrinkages of mixed powder were increased in the order of Na2SO4${\mu}{\textrm}{m}$ of pore diameter were manufactured when the filler sizes 100~200 ${\mu}{\textrm}{m}$. The open pore volume of porous glass is determined by the quantity of filler and porous glasses having open pore volume between 30 and 70 vol% are available. Available sintering temperature range for preparation of porous glass is from the softening temperature of the glass powder to eutectic melting temperature of DTA curve of mixed powder.

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A Study on Pore Water Pressure Behavior of Fill Dam with Water Level Raising using Centrifugal Model Tests (원심모형실험에 의한 수위상승시 필댐의 간극수압 거동 연구)

  • Lee, Chung-Won;Chang, Dong-Su;Park, Sung-Yong;Kim, Ki-Sung;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.2
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    • pp.87-95
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    • 2013
  • The aim of this study is to examine the behavior of reservoir fill dam with the water level raising by use of the centrifugal model test and the numerical simulation. In this study, LIQCA2D-SF based on the cyclic elasto-plastic constitutive model proposed by Oka et al. (1999) is applied for numerical simulation. In order to investigate the displacements and the pore water pressures in the fill dam due to the water level raising velocity, three model tests in centrifugal field of 50g for fill dams were conducted. A comparison between the test result and the simulation result has provided the influence on the displacement and the pore water pressure of the fill dam with increasing up of the water level.

Pore Structure and Mechanic:11 Property of Porous TiNi Biomaterial Produced by Self-Propagating High-Temperature Synthesis (고온자전합성법으로 제조된 다공성 TiNi 생체재료의 기공구조 및 기계적 특성)

  • 김지순;강지훈;양석균;정순호;권영순
    • Journal of Powder Materials
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    • v.10 no.1
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    • pp.34-39
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    • 2003
  • Porous TiNi bodies were produced by Self-propagating High-temperature Synthesis (SHS) method from a powder mixture of Ti and Ni. Porosity, pore size and structure, mechanical property, and transformation temperature of TiNi product were investigated. The average porosity and pore size of produced porous TiNi body are 63% and $216\mutextrm{m}$, respectively. XRD analysis showed that the major phase of produced TiNi body is B2 phase. Its average fracture strength and elastic modulus measured under dry condition were $22\pm2$ MPa and $0.18\pm0.01$GPa, respectively. It could be strained up to 7.3 %. The transformation temperatures determined by DSC showed the $M_s$ temperature of $67^{\circ}C$ and $A_f$ temperature of $99^{\circ}C$.

Analysis of the Behavior of Undrained Pore Water Pressure in Saturated Sand by Isotropic Loading Test (포화된 사질토에서 등방재하시험에 의한 비배수 공극수압의 거동분석)

  • Eam, Sung-Hoon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.4
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    • pp.43-52
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    • 2005
  • It is known in some literatures that the B value is not equal to unity in saturated soil when effective stress is given, in which the B Value is the ratio of measured excess pore water pressure and isometric loading pressure. In this study the B value was measured on various effective stresses and on various incremental loading stresses in various grain size of specimens with saturated sand. The test results showed that the B value was affected largely by grain size of sand in specimen and the amount of effective stress. There was the semi-logarithmic relationship between B value and effective stress, and also there was the linear relationship between the gradient of the former semi-logarithmic relationship and grain size of specimen.

A Simulation Method for Modeling the Morphology and Characteristics of Electrospun Polymeric Nanowebs

  • Kim Hyungsup;Kim Dae-Woong;Seo Moon Hwo;Cho Kwang Soo;Haw Jung Rim
    • Macromolecular Research
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    • v.13 no.2
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    • pp.107-113
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    • 2005
  • We developed an algorithm to simulate the generation of virtual nanowebs using the Monte Carlo method. To evaluate the pore size of the simulated multi-layered nanoweb, an estimation algorithm was developed using a ghost particle having zero volume and mass. The penetration time of the ghost particle through the virtual nanoweb was dependent on the pore size. By using iterative ghost particle penetrations, we obtained reliable data for the evaluation of the pore size and distribution of the virtual nanowebs. The penetration time increased with increasing number of layers and area ratio, whereas it decreased with increasing fiber diameter. Dimensional analysis showed that the penetration time can be expressed as a function of the fiber diameter, area ratio and number of layers.

Suitable Use of Capillary Number for Analysis of NAPL Removal from Porous Media

  • Jeong, Seung-Woo,
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.25-28
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    • 2004
  • The capillary number is used to represent the mobilization potential of organic phase trapped within porous media. The capillary number has been defined by three different forms, according to types of flow velocity and viscosity used in the definition of capillary number. This study evaluated the suitability of the capillary number definitions for representing TCE mobilization by constructing capillary number-TCE saturation relationships. The results implied that the capillary number should be correctly employed, according to interest of scale and fluid flow behavior. This study suggests that the pore-scale capillary number may be used only for investigating the organic-phase mobilization at the pore scale because it is defined by the pore-velocity and the dynamic viscosity. The Newtonian-fluid capillary number using Darcy velocity and the dynamic viscosity may be suitable to quantify flood systems representing Newtonian fluid behavior. For viscous-force modified flood systems such as surfactant-foam floods, the apparent capillary number definition employing macroscopic properties (permeability and potential gradient) may be used to appropriately represent the desaturation of organic-phases from porous media.

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