인위적인 온실 가스 배출로 인한 자연 재해가 증가하고 있으며 이로 인해 기체 분리막의 개발이 촉진되게 되었다. 이산화탄소(CO2)는 지구 온난화의 주요 원인이다. 고유의 유연성을 가지는 유기 고분자 막은 기체 분리막의 좋은 후보군 중 하나이며, 이 중 이산화탄소에 대한 높은 확산도를 가지고 있는 폴리디메틸실록산(PDMS)은 유망한 소재이다. 또한, 폴리비 닐피롤리돈(PVP)은 이산화탄소에 대한 높은 용해도를 가지고 있는 고분자로 기체 분리막에 활용될 수 있다. 따라서 본 연구 에서는 용이한 조건에서 간단한 단일 반응 자유 라디칼 중합에 의하여 다양한 조성의 폴리디메틸실록산-폴리비닐피롤리돈 (PDMS-PVP) 빗살 공중합체를 합성하였다. PDMS와 PVP로 합성된 공중합체는 FTIR을 통해 분석하였다. 고분자의 형태학 및 열적 특성은 TEM, TGA 및 DSC를 통하여 분석하였다. PDMS-PVP 빗살 공중합체를 다공성 폴리설폰 지지체 위에 코팅 하여 복합막을 제조했으며, 제조한 복합막의 기체 투과 특성을 분석하였다. 그 결과 이산화탄소의 투과도 및 이산화탄소/질소 선택도가 각각 140.6 GPU 및 12.0에 도달하였다.

본 연구는 기상청의 기상레이더 관측망을 이용한 하이브리드 고도면 강우추정 기법 기반의 새로운 정량적 합성강수량 추정 방법을 제시한다. HSR기법은 지형클러터, 빔차폐, 비 기상 에코 및 밝은 띠의 영향을 받지 않는 하이브리드 고도면의 반사도를 합성하는 것이 특징이다. HSR 합성반사도는 정적 HSR (STATIC)과 단일편파레이더에 대한 퍼지로직 기법과 이중편파레이더에 대한 시선방향 질감 기반의 품질관리 절차를 사용하는 동적 HSR (DYNAMIC) 합성으로 구분된다. STATIC과 DYNAMIC은 2014년 5월부터 10월까지 10개의 강우 사례에 대해 기상청 현업용 합성강우 (MOSAIC)와 비교검증 하였다. 차폐 영역에서 STATIC, DYNAMIC, MOSAIC의 상관계수는 각각 0.52, 0.78, 0.69이며 평균 상대 오차는 각각 34.08, 30.08, 40.71%로 분석되었다.

With the development of augmented reality technology, various related technologies and content production are rapidly increasing. The virtual space in the augmented reality is achieved through the synthesis of the virtual environment composed of 3D models with the background of the real world video. The harmonization of these two environments is an important factor for users enjoying augmented reality contents. In this paper, we introduce a video abstraction technique to solve the problem of mismatch between input video and 3D virtual objects, which is one of the points to be improved in augmented reality. In particular, we created a new virtual space by applying video-based cartoon and pencil stylization to transform the AR background.

광중합 방법을 이용하여 고리화 중합이 가능한 디알릴 기를 포함하는 액정 단량체를 합성하였고 이를 이용하여 액정의 상전이 특성 및 배향특성과 중합거동에 대하여 연구하였다. 액정단량체는 2-methyl-1,4-phenylene 기를 중 심구조로 하며 양 말단에 고리화 중합이 가능한 1,6-heptadienyl 기를 포함한다. 합성된 액정단량체를 1H-NMR로 구 조 분석을 하였으며 DSC와 POM을 이용하여 액정단량체의 상전이를 관찰하였다. 그 결과 합성된 합성된 액정단량체는 가열시에는 액정상이 관찰되지 않고 약 52 oC에서 등방성 액체로 녹았으며, 냉각시에는 49.1 oC에서 –9.5 oC 사이에서 전형적이 네마틱 상을 보이고 그 이하에서는 결정성을 나타내는 enatiotropic 상전이를 나타내었다. 합성된 액정 단량체는 광개시제를 포함하는 중합용액으로 제조하여 코팅 후 광조사를 통해 고리화 중합을 진행하였으며, 그 결과 고분자필름을 제조하는 데에는 성공하였으나 중합과정 중 배향이 파괴되어 광학필름으로 사용할 수는 없었다.

공액구조 고분자는 일반적으로 전도성, 착체형성, 색, 광학 비선형성, 높은 기체투과도, 광 및 전기 발광 등의 특성을 보인다. 다양한 유형의 전도성 고분자 중에서 폴리(아로마틱 헤테로사이클릭)은 해당 단량체의 화학적 혹은 전기화학적 중합을 통하여 합성되는 주쇄 방향족성 고분자이다. 이들 소재는 발광소자, 화학센서, 수퍼커페시터, 유기 태양전지, 유기 트랜지스터, 스마트 윈도우 등 다양한 응용 영역을 가지고 있다. 본고에서는 폴리(아로마틱 헤테로사 이클릭)의 합성과 응용에 관한 그동안의 연구동향을 제시하였다.

We synthesized YOF(yttirum oxyfluoride) powders through solid state reactions using Y2O3 and YF3 as raw materials. The synthesis of crystalline YOF was started at 300 oC and completed at 500 oC. The atmosphere during synthesis had a negligible effect on the synthesis of the YOF powder under the investigated temperature range. The particle size distribution of the YOF was nearly identical to that of the mixed Y2O3 and YF3 powders. When the synthesized YOF powders were used as a raw material for the suspension plasma spray(SPS) coating, the crystalline phases of the coated layer consisted of YOF and Y2O3, indicating that oxidation or evaporation of YOF powders occurred during the coating process. Based on thermogravimetric analysis, the crystalline formation appeared to be affected by the evaporation of fluoride because of the high vapor pressure of the YOF material.

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of WO3 nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of WO3 are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on WO3 nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert’s law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

기존에 많이 이용되고 있는 전기탈이온(EDI) 공정은 전기투석법과 이온교환수 지법을 혼합한 공정이다. 이 공정에 이용되는 모듈은 전기투석을 위한 양･음이 온교환막, 두 막 사이에 이온교환수지로 채워지는 형태이다. 하지만 이온교환수지와 양･음이온교환막으로 인해 모듈의 크기가 커지는 단점이 있다. 이러한 점 들을 바탕으로 현재 이온교환수지를 글라인딩하여 바이폴라형태의 막으로 만든 전기흡착탈이온 공정 모듈이 생산되고 있다. 본 연구는 모듈에 적용할 수 있는 높은 이온교환능력을 가지는 이온교환고분자를 합성하고, 이온교환수지을 대신 할 이온교환그룹을 가진 나노입자를 제조하여 이 둘을 적절하게 조절하여 하이브리드막을 제조하였다. 그리고 제조된 하이브리드막은 다양한 특성평가를 실시하였고, 그에 따른 고찰을 진행하였다.

폴리이미드는 뛰어난 기계적 강도, 내열성, 내화학성 및 여러 기체에 대한 높은 투과선택성을 가지고 있으나 유기용매에 대한 낮은 용해성으로 인해 제막할 경우 많은 제약을 받고 있다. 따라서 유기용매에 가용성을 가지는 폴리이미드에 대한 연구가 필요하다. 본 연구에서는 지환족 다이안하이드라이드인 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicar boxylic (DOCDA) 와 다양한 다이아민을 이용하여 DOCDA계 폴리이미드를 합성하였다. FT-IR을 통해 합성이 잘 이루어졌음을 확인하였고, 용해도 테스트를 통해 여러 유기용매에 대한 용해성을 확인하였다. 또한, 기체투과특성을 알아보기 위하여 time-lag 장비를 이용하여 투과도 및 선택도를 알아보았다.

We present a facile, room temperature synthesis of poly(ethylenealt- maleic anhydride)-graft-poly(propylene glycol) (PEMA-g-PPG) graft copolymer-based CO2/N2 gas separation membrane with 100% conversion reaction without any further purification process. As confirmed by the Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR) spectroscopy, the PEMA-g-PPG was successfully synthesized with 100% conversion of PEMA and PPG monomers. It was confirmed that the PEMA-g-PPG was amorphous and rubbery state according to the X-ray diffraction (XRD) and differential scanning calorimetry (DSC0 results. Therefore, PEMA-g-PPG/polysufulfone composite membrane exhibited high performance of CO2 permeability (99.1 Barrer) and selectivity (82.6 for CO2/N2 and 26.8 for CO2/CH4), surpassing conventional PEBAX block copolymer membrane.

In this study, mixed-matrix membranes (MMMs) containing MgO nanosheets (MgO-NSs) and AgBF4 in a comb copolymer matrix were successfully prepared for olefin/paraffin separation. The MgO-NSs, which were synthesized via a non-hydrothermal method, showed a large surface area with multi-mesopores. Two kinds of comb copolymers, POEM-g-PEGBEM and PHMEP-g-PEGBEM, were used as a matrix for dispersion of the MgO-NSs and AgBF4. The separation efficiency was enhanced by addition of MgO-NSs due to the dual-functionality. MgO-NSs resulted in the enhancement of the activity of silver through specific interaction and also led to increased diffusivity due to its mesoporous structure. The interactions among the MgO-NSs, silver ions, and polymer matrix were systematically characterized by using FT-IR, XPS, SAXS, and XRD analysis.

As ZIF materials have their unique properties such as high surface area, tunable pore structure, thermal and chemical stability, they can be used in various applications including gas separation and catalysis. For synthesis of ZIF membranes, fixing sub-micron ZIF seed particles on the support is challenging and important. In this work, ZIF-8 seed layer was synthesized by conversion synthesis of ZnO layer on support in H-mIm solution, followed by the secondary growth synthesis of ZIF-8 membranes. The parameters of conversion seeding had been investigated to control the reaction rate combining the dissolution rate of ZnO and the crystallization rate of ZIF-8. This ZIF-8 membranes showed the better coverage of seeding layer and improved gas separation properties compared with the membranes prepared by traditional dip-coating seeding method.

Until now, single MFI nanosheets have been prepared using a multi-step approach based on the exfoliation of layered MFI, followed by centrifugation to remove nonexfoliated particles. This top-down method is time-consuming, costly and low-yield and it produces fragmented nanosheets with sub micrometre lateral dimensions. Alternatively, direct (bottom-up) synthesis could produce high-aspect-ratio zeolite nanosheets, with improved yield and at lower cost. Here we use a nanocrystal-seeded growth method triggered by a single rotational intergrowth to synthesize high-aspect-ratio MFI nanosheets with a thickness of 5 nanometres (2.5 unit cells). These high-aspect-ratio nanosheets allow the fabrication of thin and defect-free coatings that effectively cover porous substrates. These coatings can be intergrown to produce high-flux and ultra-selective MFI membranes that compare favourably with other MFI membranes prepared from existing MFI materials (such as exfoliated nanosheets or nanocrystals).

A Nanosized WO3 and CuO powder mixture is prepared using novel high-energy ball milling in a bead mill to obtain a W-Cu nanocomposite powder, and the effect of milling time on the structural characteristics of WO3-CuO powder mixtures is investigated. The results show that the ball-milled WO3-CuO powder mixture reaches at steady state after 10 h milling, characterized by the uniform and narrow particle size distribution with primary crystalline sizes below 50 nm, a specific surface area of 37 m2/g, and powder mean particle size (D50) of 0.57 μm. The WO3-CuO powder mixtures milled for 10 h are heat-treated at different temperatures in H2 atmosphere to produce W-Cu powder. The XRD results shows that both the WO3 and CuO phases can be reduced to W and Cu phases at temperatures over 700oC. The reduced W-Cu nanocomposite powder exhibits excellent sinterability, and the ultrafine W-Cu composite can be obtained by the Cu liquid phase sintering process.

ZnS powder was synthesized using a relatively facile and convenient glycothermal method at various reaction temperatures. ZnS was successfully synthesized at temperatures as low as 125 oC using zinc acetate and thiourea as raw materials, and diethylene glycol as the solvent. No mineralizers or precipitation processes were used in the fabrication, which suggests that the spherical ZnS powders were directly prepared in the glycothermal method. The phase composition, morphology, and optical properties of the prepared ZnS powders were characterized using XRD, FE-SEM, and UV-vis measurements. The prepared ZnS powders had a zinc blende structure and showed average primary particles with diameters of approximately 20~30 nm, calculated from the XRD peak width. All of the powders consisted of aggregated secondary powders with spherical morphology and a size of approximately 0.1~0.5 μm; these powders contained many small primary nanopowders. The as-prepared ZnS exhibited strong photo absorption in the UV region, and a red-shift in the optical absorption spectra due to the improvement in powder size and crystallinity with increasing reaction temperature. The effects of the reaction temperature on the photocatalytic properties of the ZnS powders were investigated. The photocatalytic properties of the assynthesized ZnS powders were evaluated according to the removal degree of methyl orange (MO) under UV irradiation (λ = 365 nm). It was found that the ZnS powder prepared at above 175 oC exhibited the highest photocatalytic degradation, with nearly 95 % of MO decomposed through the mediation of photo-generated hydroxyl radicals after irradiation for 60 min. These results suggest that the ZnS powders could potentially be applicable as photocatalysts for the efficient degradation of organic pollutants.

Nano-sized Zinc selenide (ZnSe) powder was successfully synthesized using Zn and Se precursors in a hydrothermal process. Temperature for the synthesis was varied from 95 oC to 180 oC to evaluate its influence on the microstructural properties of the synthetic particles. ZnSe powder thus fabricated was characterized using various analytical tools such as SEM, XRD, TEM and UV-Vis methods. Two types of ZnSe particles, that is, the precipitated particle and the colloidal particles, were identified in the analysis. The precipitated particles were around 100 nm in average size, whereas the average size of the colloidal particles was around 20 nm. The precipitated particles made at 150 oC and 180 oC were found to be a single phase of ZnSe; however, an inhomogeneous phase was obtained at the lower synthesis temperature of 95 oC, suggesting that the temperature for the synthesis should be over 100 oC. The precipitated particles were inactive in the UV-Vis absorption investigation, whereas the colloidal particles showed that absorptions occurred at 380 nm in the UV-Vis spectrum.

The objective of this study was to determine the effect of fructose that was supplemented to a chemically defined in Vitro maturation (IVM) medium on oocyte maturation and embryonic development after parthenogenesis in pigs. The base medium for in Vitro maturation (IVM) was porcine zygote medium (PZM) that was supplemented with 0.05% (w/v) polyvinyl alcohol (PVA) or 10% (v/v) porcine follicular fluid (pFF). In the first experiment, when immature pig oocytes were matured in a chemically defined medium that was supplemented with 5.5 mM glucose or with 1.5, 3.0 and 5.5 mM fructose, 3.0 mM fructose resulted in a higher nuclear maturation (91.5%) than 1.5 and 5.5 mM fructose (81.9 and 81.9%, respectively) but showed a similar result with 5.5 mM glucose (94.2%). However, there was no significant differences among groups in the embryo cleavage (89.4-92.4%), blastocyst formation (37.5-41.1%), and mean cell number of blastocyst (30.8-34.2 cells). Fructose at the concentration of 3.0 mM (1.08 pixels/oocyte) resulted in a higher intra-oocyte glutathione (GSH) content than 1.5 and 5.5 mM fructose (1.00 and 0.87 pixels/oocytes, respectively) while the cumulus cell expansion was not influenced. In the second experiment, effect of individual and combined supplementation of a chemically defined maturation medium with 5.5 mM glucose or 3.0 mM fructose was examined. No significant effect was found in the nuclear maturation (86.3-92.6%). Embryo cleavage was significantly increased by the combined supplementation with glucose and fructose (95.2%) compared to that with 3.0 mM fructose only (85.7%) while blastocyst formation (37.3-42.8%) and embryonic cell number (33.3-34.1 cells) were not altered. Effect of supplementation of pFF-containing medium with glucose and fructose + glucose was examined in the third experiment. No significant effect by the supplementation with glucose and fructose or glucose alone was observed in the nuclear maturation of oocytes (90.7-94.1%) and blastocyst formation (51.0-56.5%). Our results demonstrate that 3.0 mM fructose was comparable to 5.5 mM glucose in supporting in Vitro oocyte maturation and embryonic development after parthenogenesis and could be used as an alternative energy source to glucose for in Vitro maturation of pig oocytes.

The SLIM AU composite beam consists of U-shaped steel plate, A-shaped steel cap and infilled concrete. The bottom steel plate acts as tension bars, and the top steel cap takes roles of shear connector and compression bars in the conventional reinforced concrete section. In this paper the shear strength of this composite beam with closed steel section has been evaluated through the concentrated loading shear experiments. Test results under the symmetrical and asymmetrical loading conditions were compared with the predicted values based on the KBC 2016. The composite beam showed the greater shear strength capacities than those of the theoretical evaluation.

Most of the cultural assets in Korea are wooden structures. Due to the material characteristics of wood, the preservation of traditional wooden structure is impossible by simple maintenance. Damaged member is replaced with new member or completely dissolve and restore them. But member has a cultural value, so that it is impossible to arbitrarily replace each member. Although the preservation treatment method using synthetic resin is emphasized, there is no exact standard for proper reinforcement ratio. This paper is experimental study for reinforcement ratio of wooden flexural member with synthetic resins, Reinforced ratio on section area of flexural member. As a result, synthetic resin reinforcement are selected as experimental variables by proper ratio enhanced flexural capacity of reinforced wooden member than new wooden member.