• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.65-67
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• 2011

The moment-of-fluid (MOF) method is a new volume-tracking method that accurately treats evolving material interfaces. The MOF method uses moment data, namely the material volume fraction, as well as the centroid, for a more accurate representation of the material configuration, interfaces and concomitant volume advection. In this paper, unstructured mesh extension of the MOF method is to be presented. The MOF method is coupled with a stabilized finite element incompressible Navier-Stokes solver for two materials. The effectiveness of the MOF method is demonstrated with a free-surface dam-break problem.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.402-407
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• 2022

Statistical design of experiments was used to optimize the MOF-5 synthesis process. A mixture design was employed to optimize precursor concentration. The optimal composition of three chemical materials, terephthalic acid, zinc acetate dihydrate, and N,N-dimethylformamide for MOF-5 synthesis was determined by extreme vertices design methods as follows; 1 mol : 2.7 mol : 40 mol. A multilevel factorial design was selected to screen the significance of synthesis reaction conditions such as temperature, time, and stirring speed. Statistical analysis results suggested excluding stirring speed from further investigation. Using a central composition design, the synthesis time and temperature were optimized. The quadratic model equation was derived from 13 synthesis experiments. The model predicted that MOF-5 synthesized at 119 ℃ for 10.4 h had the highest crystallinity.

• Membrane Journal
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• v.25 no.6
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• pp.465-477
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• 2015

Recently membrane-based gas separation has attracted a lot of attention due to the growing demands on energy efficient separation processes. Current membrane-based gas separation is dominant by polymer membranes and limited mostly to non-condensable gases rather than condensable gases such as hydrocarbon isomers due to the limitation s of polymer materials. Metal-organic framework (MOF) materials, consisting of metal ions and organic ligands, have received a tremendous attention as membrane materials due to high surface area, controllable pore structure, and functionality. In this review, we provide a recent development of MOF membrane preparation methods and their gas separation applications.

• Membrane and Water Treatment
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• v.13 no.6
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• pp.321-335
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• 2022

Copper-based Metal-organic framework (MOF) namely ([Cu (INA)₂]-MOF) is synthesized by ball milling and characterized using scanning electron microscopy (SEM) for the topography, microstructure, and elemental evidence determination, powdered X-ray diffraction (XRD) for the crystallinity measurement, thermogravimetric (TG) analysis was performed to determine the thermal stability of the material, and Fourier transformed infrared (FTIR) spectroscopy for functional groups identification. The use of [Cu (INA)₂]-MOF as hazardous removal material of β-agonists as persistent hazardous micro-pollutants in our environmental water is first reported in this study. The removal efficiency of the Cu-MOF is successfully determined to be 97.7% within 40 minutes, and the MOF has established an exceptional removal capacity of 835 mg L^-1 with 95 % percent removal on Clenbuterol (CLB) even after the 5th consecutive cycle. The Langmuir model of the adsorption isotherms was shown to be more favourable, while the pseudo-second-order model was found to be favoured in the kinetics. The reaction was exothermic and spontaneous from a thermodynamic standpoint, and the higher temperatures were unfavourable for the adsorption study of the CLB. As a result, the studied MOF have shown promising properties as possible adsorbents for the removal of CLB in wastewater.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.621-626
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• 2021

A sequential design of experiments was used to optimize MOF-801 synthesis process. For the initial screening, a general 2^k factorial design was selected followed by the central composition design, one of the response surface methods. A 2³ factorial design based on the molar ratio of fumaric acid, dimethylformamide (DMF), and formic acid was performed to select the more suitable response variable for the design of experimental method among the crystallinity and BET specific surface area of MOF-801. After performing 8 synthesis experiments designed by MINITAB 19 software, the characteristic analysis was performed using XRD analysis and nitrogen adsorption method. The crystallinity with R² = 0.999 was found to be more suitable for the experimental method than that of BET specific surface area. Based on analysis of variance (ANOVA), it was confirmed that the molar ratio of fumaric acid and formic acid was a major factor in determining the crystallinity of MOF-801. Through the response optimization and contour plot of two factors, the optimal molar ratio of ZrOCl₂·8H₂O : fumaric acid : DMF : formic acid was 1 : 1 : 39 : 35. In order to optimize the synthesis process, the central composition design on synthesis time and temperature was performed under the identical molar ratio of precursors. The results derived through the designed 9 synthesis experiments were calculated using the quadratic model equation. Thus, the maximum crystallinity of MOF-801 predicted under the synthesis time and temperature of 7.8 h and 123 ℃, respectively.

• Journal of Energy Engineering
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• v.27 no.4
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• pp.80-85
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• 2018

Usable capacity is one of the most important parameters for evaluating the performance of an adsorbent for $CO_2$ capture from flue gas streams. In the pressure swing adsorption (PSA) process, the usable capacity is calculated as the difference between the quantity adsorbed in flue gas at high pressure (ca. 20 bar) and the quantity adsorbed at lower purge pressure (ca. 2 bar). In this paper, two stereo-types of metal-organic framework (MOF) were evaluated as an promising adsorbent for $CO_2$ capture: flexible structured MOF (MIL-53) and MOF possessing strong binding sites (MOF-74). The results showed that a total $CO_2$ capture capacity is strongly related to the specific surface area and heat of adsorption, revealing high uptake in MOF-74. However, the usable capacity was more pronounced in MIL-53 due to a structural transition.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.171-180
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• 2013

Metal organic frameworks (MOFs) are a class of crystalline organic-inorganic hybrid compounds formed by coordination of metal clusters or ions with organic linkers. MOFs have recently attracted intense research interest due to their permanent porous structures, large surface areas and pore volume, high-dispersed metal species, and potential applications in gas adsorption, separation, and catalysis. $CO_2$ adsorption in MOFs has been investigated in two areas of $CO_2$ storage at high pressures and $CO_2$ adsorption at atmospheric pressure conditions. In this short review, $CO_2$ adsorption/separation results using MOFs conducted in our laboratory was explained in terms of four contributing effects; (1) coordinatively unsaturated open metal sites, (2) functionalization, (3) interpenetration/catenation, and (4) ion-exchange. Zeolitic imidazolate frameworks (ZIFs) and covalent organic frameworks (COFs) were also considered as a candidate material.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1200-1207
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• 2020

We have fabricated the supercapacitor composed of porous activated carbon, metal-organic framework (MOF) with polymer based solid state electrolyte as a "ion gel" and characterized its electrochemical behaviour as a function of the MOF contents. The electrochemical properties of the supercapacitor were analyzed via cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge test. As a results, the supercapacitor based on porous activated carbon/MOF composite showed the highest capacitance value at 0.5 wt% of MOF contents and decreased capacitance with increase MOF contents over the 0.5 wt%. Consequently, the porous activated carbon/MOF composite based supercapacitor is applicable to various aspect for energy storage device.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.377-385
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• 2008

In this study, we demonstrated that, although hydrogen molecules can be adsorbed onto the adsorbent such as MOF and MC itself, the loading of noble metal such as Pt is necessary to enhance the $H_2$ storage capacity since $H_2$ molecules can be dissociatively adsorbed on Pt metal and migrated to high-surface-area adsorbent via the primary spillover. In addition, the hybrid material have been prepared coupling MOF-5 with Pt/MC through carbon bridges formed by sucrose polymerization/carbonization. That this material showed the highest $H_2$ uptake at room temperature and about 100 bar is believed to be associated with the secondary spillover effect. Thus, such a strategy is very promising in developing $H_2$ storage technology using porous adsorbents. However, further experiments should be carried out to explore the choice of bridge carbon, the hybridization method, the dispersion technique of noble metals, etc.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.184-194
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• 2021

Histone acetylation is a well-characterized epigenetic modification controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Imbalanced histone acetylation has been observed in many primary cancers. Therefore, efforts have been made to find drugs or small molecules such as HDAC inhibitors that can revert acetylation levels to normal in cancer cells. We observed dose-dependent reduction in the endogenous and exogenous protein expression levels of KAT8 (also known as human MOF), a member of the MYST family of HATs, and its corresponding histone acetylation at H4K5, H4K8, and H4K16 in chemotherapy drug gemcitabine (GEM)-exposed T24 bladder cancer (BLCA) cells. Interestingly, the reduction in MOF and histone H4 acetylation was inversely proportional to GEM-induced γH2AX, an indicator of chemotherapy drug effectiveness. Furthermore, pGL4-MOF-Luc reporter activities were significantly inhibited by GEM, thereby suggesting that GEM utilizes an MOF-mediated anti-BLCA mechanism of action. In the CCK-8, wound healing assays and Transwell® experiments, the additive effects on cell proliferation and migration were observed in the presence of exogenous MOF and GEM. In addition, the promoted cell sensitivity to GEM by exogenous MOF in BLCA cells was confirmed using an Annexin V-FITC/PI assay. Taken together, our results provide the theoretical basis for elucidating the anti-BLCA mechanism of GEM.