• Title/Summary/Keyword: MOF

Search Result 216, Processing Time 0.024 seconds

Hydraulic Experiments on Stable Armor Weight and Covering Range of Round Head of Rubble-Mound Breakwater Armored with Tetrapods: Non-breaking conditions (경사식방파제 제두부에 거치된 Tetrapod의 안정중량 및 피복범위에 관한 수리실험: 비쇄파 조건)

  • Kim, Young-Taek;Lee, Jong-In
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.29 no.6
    • /
    • pp.389-398
    • /
    • 2017
  • The re-analysis on the stable weight of the concrete armor unit (CAU) at the roundhead and the suggestion of the covering range at the roundhead with the increased weight of CAU were conducted. Tetrapods were applied to the tests and the three dimensional hydraulic tests were performed. The test results for the stable weight at the roundhead area were similar to the guides from Korean Design Standard for Harbour and Fishery Port (MOF, 2014) and Coastal Engineering Manual (USACE, 2005). The investigation of covering range at the roundhead of rubble mound structures armoured with Tetrapods was suggested that the length of five times of the design wave height from the tip of the superstructure was needed and appropriate. Both sides of the superstructure should be covered with increasing weighted CAU to satisfy the stability at roundhead area.

Current Status and Improvement of the Fisheries Supply and Demand Statistics (수산물 수급통계 실태 및 개선과제)

  • Lee, Heon-Dong;Kim, Dae-Young
    • The Journal of Fisheries Business Administration
    • /
    • v.48 no.2
    • /
    • pp.19-32
    • /
    • 2017
  • The purpose of this study is to identify problems and suggest improvements of estimating procedures and item of fisheries supply-demand statistics served as a basis for the fisheries supply-demand policies. Korea Rural Economic Institute(KREI) and Ministry of Oceans and Fisheries(MOF) respectively publish the fisheries supply-demand statistics. But the reliability of data is low as the statistics of these two organizations are limited and show discrepancy in the numbers. It is therefore difficult to use them as the basic data for policies. Also, an accurate data aggregation is difficult due to following problems in the items of statistics. 1) Problems in estimating route sales and non-route sales of production, 2) adequacy of fishery product yield rate compared to raw material in the fisheries import/export sector, 3) selection of target companies for understand stocks and survey scope of fish species, 4) applying'0'to non-edible product demand etc. In order to develop the fisheries industry as a future growth industry, it is necessary to establish the accurate fisheries supply-demand policy as the instability of fisheries supply and demand is increasing. To do this, statistical reliability has to be improved. The improvements proposed in this study should be implemented considering urgency. First of all, an exhaustive analysis of stock statistics and conversion rates of raw material yield in the fisheries import/export sector should be conducted. In the medium term and the long term, transferring production statistics to MOF and surveys on the use demand of non-food product and the level of reduced and discarded seafood products should be carried out in consecutive order.

Preparation of Co3O4/NF Anode for Lithium-ion Batteries

  • Tian, Shiyi;Li, Botao;Zhang, Bochao;Wang, Yang;Yang, Xu;Ye, Han;Xia, Zhijie;Zheng, Guoxu
    • Journal of Electrochemical Science and Technology
    • /
    • v.11 no.4
    • /
    • pp.384-391
    • /
    • 2020
  • Due to its characteristics of light weight, high energy density, good safety, long service life, no memory effect, and environmental friendliness, lithium-ion batteries (LIBs) are widely used in various portable electronic products. The capacity and performance of LIBs largely depend on the performance of electrode materials. Therefore, the development of better positive and negative materials is the focus of current research. The application of metal organic framework materials (MOFs) derivatives in energy storage has attracted much attention and research. Using MOFs as precursors, porous metal oxides and porous carbon materials with controllable structure can be obtained. In this paper, rod-shaped Co-MOF-74 was grown on Ni Foam (NF) by hydrothermal method, and then Co-MOF-74/NF precursor was heat-treated to obtain rodshaped Co3O4/NF. Ni Foam was skeleton structured, which effectively relieved. The change of internal stress changes and destroys the structural volume of the electrode material and reduces the capacity attenuation. Co3O4/NF composite material has a specific discharge capacity of up to 1858 mA h/g for the first time, and a reversible capacity of up to 902.4 mA h/g at a current density of 200 mA/g, and has excellent rate and impedance performance. The synthesis strategy reported in this article opens the way to design high-performance electrodes for energy storage and electrochemical catalysis.

A UML Profile for Specifying Component Design as MDA/PIM (컴포넌트 설계를 MDA/PIM으로 명세하기 위한 UML프로파일)

  • Min Hyun Gi;Kim Soo Dong
    • Journal of KIISE:Software and Applications
    • /
    • v.32 no.3
    • /
    • pp.153-162
    • /
    • 2005
  • Component Based Development (CBD) is appealing as a technology to improve the productivity of software development through component reuse. Model Driven Architecture (MDA) is a new development paradigm which automatically generates application by transforming design models incrementally. Since both reusability of CBD and model transformation of MDA increase software productivity. integration of two technologies is desirable. To enable this technology integration, we need to devise a UML profile for specifying component design as a PIM. In this paper, we first define a meta-model for components, and propose a UML profile which is used to specify elements of component design as PIM. Since the proposed profile is based on Meta Object Facility (MOF) from which is MDA is derived, it is consistent and compatible with existing MDA methods and tools.

Aldol Condensation over Acid-Base Bifunctional Metal-Organic Framework Catalysts (산, 염기 이원기능 금속-유기 구조체 촉매를 이용한 알돌 축합반응)

  • Chung, Young-Min
    • Clean Technology
    • /
    • v.20 no.2
    • /
    • pp.116-122
    • /
    • 2014
  • Various types of MOFs (metal-organic frameworks) were prepared via hydrothermal and post-grafting methods and applied as catalysts for the synthesis of jasminaldehyde, one of the representative perfume intermediates, by Aldol condensation of benzaldehyde with heptanal. Although both acid and base sites could catalyze the reaction, the catalytic performance was strongly dependent on the physical properties as well as the nature of functionalization on MOFs. While the use of sulfonated MOF catalysts led to decrease of jasminaldehyde selectivity regardless of MOFs used, the selectivity change was found to rely on the MOF types in the case of the amine-functionalization. Among the catalysts tested, MIL-101 shows the best catalytic performance, which may suggest that MIL-101 has suitable acid properties to promote the Aldol condensation and the large pore of MIL-101 is also advantageous to alleviate the diffusion problem of bulky products.

Adsorption and Photocatalytic Degradation of Dyes Using Synthesized Metal-Organic Framework NH2-MIL-101(Fe) (합성 금속-유기 골격체 NH2-MIL-101(Fe)를 이용한 염료의 흡착 및 광분해 제거)

  • Lee, Joon Yeob;Choi, Jeong-Hak
    • Journal of Environmental Science International
    • /
    • v.27 no.7
    • /
    • pp.611-620
    • /
    • 2018
  • In this study, a metal-organic framework (MOF) material $NH_2$-MIL-101(Fe) was synthesized using the solvothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectrophotometry, field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and surface area measurements. The XRD pattern of the synthesized $NH_2$-MIL-101(Fe) was similar to the previously reported patterns of MIL-101 type materials, which indicated the successful synthesis of $NH_2$-MIL-101(Fe). The FT-IR spectrum showed the molecular structure and functional groups of the synthesized $NH_2$-MIL-101(Fe). The UV-visible absorbance spectrum indicated that the synthesized material could be activated as a photocatalyst under visible light irradiation. FE-SEM and TEM images showed the formation of hexagonal microspindle structures in the synthesized $NH_2$-MIL-101(Fe). Furthermore, the EDS spectrum indicated that the synthesized material consisted of Fe, N, O, and C elements. The synthesized $NH_2$-MIL-101(Fe) was then employed as an adsorbent and photocatalyst for the removal of Indigo carmine and Rhodamine B from aqueous solutions. The initial 30 min of adsorption for Indigo carmine and Rhodamine B without light irradiation achieved removal efficiencies of 83.6% and 70.7%, respectively. The removal efficiencies thereafter gradually increased with visible light irradiation for 180 min, and the overall removal efficiencies for Indigo carmine and Rhodamine B were 94.2% and 83.5%, respectively. These results indicate that the synthesized MOF material can be effectively applied as an adsorbent and photocatalyst for the removal of dyes.

Synthesis of RuO2/h-Co3O4 Electrocatalysts Derived from Hollow ZIF and Their Applications for Oxygen Evolution Reaction (중공 ZIF를 이용한 RuO2/h-Co3O4 촉매의 합성 및 산소 발생 반응으로의 활용)

  • Yoonmo Koo;Youngbin Lee;Kyungmin Im;Jinsoo Kim
    • Applied Chemistry for Engineering
    • /
    • v.34 no.2
    • /
    • pp.180-185
    • /
    • 2023
  • To improve the efficiency of water electrolysis, it is essential to develop an oxygen evolution reaction (OER) electrocatalyst with high performance and long-term stability, accelerating the reaction rate of OER. In this study, a hollow metal-organic framework (MOF)-derived ruthenium-cobalt oxide catalyst was developed to synthesize an efficient OER electrocatalyst. As the synthesized catalyst increases the surface exposure of ruthenium, a low overpotential (386 mV) was observed at a current density of 10 mA/cm2 with a low Tafel slope. It is expected to be able to replace noble metal catalysts by showing higher mass activity and stability than commercial RuO2 catalysts.

Ionic Liquid Consisted of Composite Membrane for Carbon Dioxide Separation: A Review (이산화탄소 분리를 위한 이온성 액체 기반 복합 멤브레인: 총설)

  • Young Simon Shi Young;Rajkumar Patel
    • Membrane Journal
    • /
    • v.33 no.5
    • /
    • pp.240-247
    • /
    • 2023
  • Even among gas separation methods, CO2 capture and separation via membranes is an ever-growing field, with many different membrane compositions continually being developed. Ionic liquid (IL) based composite membranes show excellent performance values in separating CO2. Similarly, various copolymer/IL composite membranes also display improved performance. The addition of fillers such as graphene oxide to these copolymer/IL composite membranes shows a further enhanced version of these fillers, most likely due to the strong interactions that occur between ILs and organic fillers, which consequently improves factors such as the affinity, selectivity, and adsorption of CO2. Copolymer/IL composite membranes utilizing a metal-organic framework (MOF) showed improved CO2 permeability. This review discusses the study of various combinations of ionic liquid and copolymer composite membranes for carbon dioxide separation.

Control of Water-Adsorption Properties of Mesoporous Silica and MOF by Ion Exchange and Salt Impregnation (양이온 교환 및 염 함침을 통한 메조다공성 실리카와 유기-금속 구조체의 수분 흡착 특성 조절)

  • Lee, Eun Kyung;Cho, Kanghee;Kim, Sang Kyum;Lim, Jong Sung;Kim, Jong-Nam
    • Clean Technology
    • /
    • v.24 no.1
    • /
    • pp.55-62
    • /
    • 2018
  • The adsorbent used in water-adsorption cooling system utilizing low-temperature heat of below $90^{\circ}C$ is required to exhibit high water uptake capacity at a relative humidity ($P/P_0$) between 0.1 and 0.3. Mesoporous silica (MCM-41) and MOF(MIL-101) exhibit quite large water adsorption capacity under saturated water vapor at $35^{\circ}C$. However, these adsorbents show small water adsorption capacity ($0.027{g_{water}\;g_{ads}}^{-1}$, $0.074{g_{water}\;g_{ads}}^{-1}$, respectively) in the relative humidity ($P/P_0$) range of 0.1 to 0.3. In this study, the surface properties of mesoporous silica and MOF were modified by simple methods to develop an adsorbent having a higher water uptake than the conventional water adsorbents at a relative humidity ($P/P_0$) of 0.1 ~ 0.3. In the case of mesoporous silica (MCM-41) exhibiting mainly water adsorption at $P/P_0=0.5{\sim}0.7$, aluminum species was functionalized on the mesopore walls and then cations existing near the aluminum were exchanged with various cations (e.g., $Na^+$, ${NH_4}^+$, and $(C_2H_5)_4N^+$). In addition, 20 wt% (to total weight of the composites) of hygroscopic inorganic salt ($CaCl_2$) was impregnated on the MCM-41. In the case of the MIL-101 (MOF), 20 wt% of hygroscopic inorganic salt ($CaCl_2$) was impregnated on the MIL-101. The MCM-41 which was ion-exchanged with various cations has main adsorption branch around 0.5 of $P/P_0$ which was slightly shifted with low-pressure direction in comparison with pristine MCM-41. However, tiny increases were observed on the adsorption in the range of $P/P_0$ between 0.1 and 0.3. After salt impregnation on the MCM-41, the adsorption capacity under $P/P_0=0.1{\sim}0.3$ at $35^{\circ}C$ was increased from $0.027{g_{water}\;g_{ads}}^{-1}$ to $0.152{g_{water}\;g_{ads}}^{-1}$. In the case of MIL-101, the amount of water adsorption at $35^{\circ}C$ under $P/P_0=0.1{\sim}0.3$ was increased from $0.074{g_{water}\;g_{ads}}^{-1}$ to $0.330{g_{water}\;g_{ads}}^{-1}$ after the salt impregnation.