• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.165-165
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• 2009

• 한국연초학회지
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• 제14권1호
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• pp.87-93
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• 1992

The adsorption efficiency of some adsorbents for the organic solvents and gas phase of smoke was investigated. 1. Specific surface area of activated carbon increased to 1900 mfg with increased activation time. 2. Adsorption efficiency of benzene and acetone increased with increasing total surface area. Adsorption capacity for gas phase such as hydrogen cyanide, aldehyde was proportional to the micro pore surface area under 20A. 3. The removal efficiency of particulate matter of smoke was higher with the adsorbents of relatively higher pore size compared to that of micro pore.

• Environmental Engineering Research
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• 제17권2호
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• pp.83-88
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• 2012

Currently, the technology of $CO_2$ capture and storage (CCS) has become the main issue for climate change and global warming. Among CCS technologies, the prediction of $CO_2$ behavior underground is very critical for $CO_2$ storage design, especially for its safety. Hence, the purpose of this paper is to model and simulate $CO_2$ flow and its heat transfer characteristics in a storage site, for more accurate evaluation of the safety for $CO_2$ storage process. In the present study, as part of the storage design, a micro pore-scale model was developed to mimic real porous structure, and computational fluid dynamics was applied to calculate the $CO_2$ flow and thermal fields in the micro pore-scale porous structure. Three different configurations of 3-dimensional (3D) micro-pore structures were developed, and compared. In particular, the technique of assigning random pore size in 3D porous media was considered. For the computation, physical conditions such as temperature and pressure were set up, equivalent to the underground condition at which the $CO_2$ fluid was injected. From the results, the characteristics of the flow and thermal fields of $CO_2$ were scrutinized, and the influence of the configuration of the micro-pore structure on the flow and scalar transport was investigated.

• Smart Structures and Systems
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• 제23권5호
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• pp.479-493
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• 2019

In this paper, the interaction between notch and micro pore under uniaxial compression has been performed experimentally and numerically. Firstly calibration of PFC2D was performed using Brazilian tensile strength, uniaxial tensile strength and biaxial tensile strength. Secondly uniaxial compression test consisting internal notch and micro pore was performed experimentally and numerically. 9 models consisting notch and micro pore were built, experimentally and numerically. Dimension of these models are 10 cm*1 cm*5 cm. the length of joint is 2 cm. the angularities of joint are $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. For each joint angularity, micro pore was situated 2 cm above the lower tip of the joint, 2 cm above the middle of the joint and 2 cm above the upper of the joint, separately. Dimension of numerical models are 5.4 cm*10.8 cm. The size of the cracks was 2 cm and its orientation was $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. Diameter of pore was 1cm which situated at the upper of the notch i.e., 2 cm above the upper notch tip, 2 cm above the middle of the notch and 2 cm above the lower of the notch tip. The results show that failure pattern was affected by notch orientation and pore position while uniaxial compressive strength is affected by failure pattern.

• 공업화학
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• 제20권4호
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• pp.396-401
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• 2009

전기이중층 캐패시터의 성능향상을 위한 전극물질로서 resorcinol-formaldehyde수지를 탄소원으로 사용하여 meso-pore 비율 52~64%의 기공특성을 지니며 직경 $2{\sim}10{\mu}m$의 미세구형 활성탄을 제조하였다. 이 활성탄을 전기이중층에 적용한 결과, meso-pore구조의 미세구형활성탄은 전하전달저항의 저감 및 충방전율 수용능력 향상에 효과적인 영향을 나타내어 전기이중층 캐패시터의 성능향상을 위한 효과적인 전극물질이 될 수 있음을 확인할 수 있었다.

• Korean Chemical Engineering Research
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• 제60권4호
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• pp.557-563
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• 2022

극세 공극 직물의 알레르겐 투과율을 측정하기 위해서는 극세 공극 직물의 공극을 측정하는 편리하고 적절한 실험 장치의 연구 개발이 필요하다. 본 연구에서는 중량 감소율을 측정하여 극세 공극 직물의 공극 크기를 측정하기 위한 간단하고 경제적인 실험 방범을 개발하였다. 또한, 개발된 미세 입자 투과 장치를 사용하여 다양한 직물의 공극 크기를 측정하여 알레르겐 차단 성능을 평가하였다. 본 연구에 의하면 극세 공극 직물의 공극의 크기는 중량 감소 비율을 측정함으로써 구할 수 있었다. 또한 중량 감소 비율의 값은 입자 투과 장치를 통과하는 흡입 압력이 작을수록, 흡입 시간이 길수록 큰 값을 나타났으며, 이 값으로부터 직선 삽입 방법을 통하여 실험 직물의 공극 크기를 측정 할 수 있었다. 개발된 실험 장치 및 방법은 집먼지 진드기 차단 침구에 사용되는 극세 공극 직물에 대하여 그 효과를 검증하는 품질 관리 방법의 실험 기준으로 사용될 수 있을 것으로 기대된다.

• 한국세라믹학회지
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• 제34권8호
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• pp.834-842
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• 1997

Controlled Ca impurity implanted inner crack-like pore in the high purity alumina single crystal, sapphire, had been created by micro-fabrication technique, which includes ion implantation, photo-lithography, Ar ion milling, and hot press technique. The morphological change and the healing of cracklike pore in Ca doped high purity single crystal alumina, sapphire, during high temperature heat treatment in vacuum were observed using optical microscopy. The dot-like surface roughening was developed and hexagon like crystal appeared on inner surface of crack-like pore after heat treatment. Bar type crystals, probably CaO.6Al2O3, were observed on the inner surface after 1 hour heat treatment at 1, 50$0^{\circ}C$, but this bar type crystal disappeared after 1 hour heat treatment at 1, $600^{\circ}C$. This disappearance means that there should be a little increase of Ca solubility limit to alumina at this temperatures.

• Membrane and Water Treatment
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• 제13권6호
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• pp.313-320
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• 2022

Theoretical calculation results are presented for the enhancement of the water mass flow rate through the hydrophobic micro/nano pores in the membrane respectively on the micrometer and nanometer scales. The water-pore wall interfacial slippage is considered. When the pore diameter is critically low (less than 1.82nm), the water flow in the nanopore is non-continuum and described by the nanoscale flow equation; Otherwise, the water flow is essentially multiscale consisting of both the adsorbed boundary layer flow and the intermediate continuum water flow, and it is described by the multiscale flow equation. For no wall slippage, the calculated water flow rate through the pore is very close to the classical hydrodynamic theory calculation if the pore diameter (d) is larger than 1.0nm, however it is considerably smaller than the conventional calculation if d is less than 1.0nm because of the non-continuum effect of the water film. When the driving power loss on the pore is larger than the critical value, the wall slippage occurs, and it results in the different scales of the enhancement of the water flow rate through the pore which are strongly dependent on both the pore diameter and the driving power loss on the pore. Both the pressure drop and the critical power loss on the pore for starting the wall slippage are also strongly dependent on the pore diameter.

• 한국염색가공학회지
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• 제11권6호
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• pp.1-6
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• 1999

The porosities of PET fibers were investigated using a nitrogen porosimeter according to oxygen plasma treatment and dyeing with a disperse dye, and they were discussed in terms of the change of internal micro-structure of the PET fiber. The total pore volume, surface area and average pore size of the plasma treated PET fibers increased expectably compared with the untreated sample. The PET fibers treated with oxygen plasma and then dyed with a disperse dye were increased significantly in the surface area and the total pore volume comparing with those of plasma treated only, but decreased in the average pore size. The increase of the surface area, after dyeing, of the plasma treated PET fibers was due to addition of the surface area of the dye itself to that of the PET fiber. The increase of the total pore volume of the plasma treated PET fibers by dyeing, which is the opposite result to the general idea that the pore volume of fibers would be reduced by occupation of dye molecules in the pores, could be explained by the free-volume model. This is that the amorphous region in the fiber expanded by occupation of dye molecules, and the marginal space surrounding dyes was generated as many smaller pores, and the decrease of the average pore size of the dyed sample also could be explained The decrease of the average pore size was caused by the splitting of a larger pore into smaller pores.

• 콘크리트학회논문집
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• 제17권5호
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• pp.857-868
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• 2005

This paper deals with the accumulated damage in concrete structures due to the cyclic freeze-thaw as an environmental load. The cyclic ice body nucleation and growth processes in porous systems are affected by the thermo-physical and mass transport properties, and gradients of temperature and chemical potentials. Furthermore, the diffusivity of deicing chemicals shows significantly higher value under cyclic freeze-thaw conditions. Consequently, the disintegration of concrete structures is aggravated at marine environments, higher altitudes, and northern areas. However, the properties of cyclic freeze-thaw with crack growth and diffusion of chloride ion effects are hard to be identified in tests, and there has been no analytic model for the combined degradations. The main objective is to determine the driving force and evaluate the reduced strength and stiffness by freeze-thaw. For the development of computational model of those coupled deterioration, micro-pore structure characterization, pore pressure based on the thermodynamic equilibrium, time and temperature dependent super-cooling with or without deicing salts, nonlinear-fracture constitutive relation for the evaluation of internal damage, and the effect of entrained air pores (EA) has been modeled numerically. As a result, the amount of ice volume with temperature dependent surface tensions, freezing pressure and resulting deformations, and cycle and temperature dependent pore volume has been calculated and compared with available test results. The developed computational program can be combined with DuCOM, which can calculate the early aged strength, heat of hydration, micro-pore volume, shrinkage, transportation of free water in concrete. Therefore, the developed model can be applied to evaluate those various practical degradation cases as well.