Preservation of wooden structure due to deterioration and corrosion is based on preservation of original form, and wooden member should not be arbitrarily replaced or damaged. Accordingly, preservation processing method with synthetic resins is embossed. But it has an adverse effect because there is no exact standard for the reinforcement ratio with the synthetic. This paper experimental study for reinforcement ratio of wooden compressive member with synthetic resins, Reinforced ratio on section area of compressive member and direction. As a result, synthetic resin reinforcement selected as experimental variables by proper ratio enhanced compressive capacity of reinforced wooden member, than new wooden member.

Recently, a new long span composite rahmen bridge has been developed to complement the short span concrete rahmen bridges. In this study, a static bending test was carried out for steel composite rahmen bridges developed for the purpose of decreasing negative moment at the end of steel girder and positive moment at the center of steel girder by introducing a horizontal prestress to the upper flange of the steel girder end. From this, the reinforcement effect of the introduction to the horizontal prestress was verified and the structural safety for the steel composite rahmen bridges was evaluated. As a result, the maximum tensile strain and the maximum compressive strain of the DL specimen at 800 kN were 16% and 12% smaller than those of the CR specimen, respectively. From this, the DL specimen decreased compressive strain due to the tensile strain of the upper flange caused by introducing the horizontal prestress at the end of the steel girder, and the tensile strain of the lower flange also decreased.

4,4'(hexafluoroisopropylidene) diphthalic anhydride (6FDA)와 4,4'-oxydianiline (ODA)로부터 용해성이 있는 폴리이미드인 chloromethylated polyimide(CPI)를 합성하고 이를 chloromethylmethyl ether로 hloromethylatation 시켰 다. 다음 CPI를 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) 촉매 존재하에서 carboxy-terminated PEG와 반응함으로써 PEG-grafted polyimide를 합성하였다. 합성된 고분자는 1H-NMR, FT-IR, DSC, TGA 등으로 구조 분석하였다. PEG-grafted polyimide의 고분자 고체전해질로의 응용을 위해 lithium trifluoromethanesulfonate와 lithium perchlorate 등의 리티움염을 섞은 후 impedance spectroscopy를 이용하여 이온전도도를 측정하였는데 그 결과 상온 에서 10-5 ~ 10-6 S/cm 정도의 전도도를 얻었다.

YSZ (Yttria-stabilized zirconia) is a ceramic material that is used for electronic and structural materials due to its excellent mechanical properties and specific electrical characteristics according to the Yttrium addition. Hydrothermal synthesis has several advantages such as fine particle size, uniform crystalline phase, fast reaction time, low process temperature and good dispersion condition. In order to synthesize YSZ nanoparticles with high crystallinity, hydrothermal synthesis was performed at various concentrations of NaOH. The hydrothermal process was held at a low temperature (100 °C), with a short process time (2,4,8 hours); the acidity or alkalinity of solution was controlled in a range of pH 2~12 by addition of NaOH. The optimum condition was found to be pH 12, at which high solubility levels of Y(OH) and Zr(OH) were reported. The synthesized nano powder showed high crystallinity and homogenous composition, and uniform particle size of about 10 nm.

The structural formation of inorganic nanoparticles dispersed in polymer matrices is a key technology for producing advanced nanocomposites with a unique combination of optical, electrical, and mechanical properties. Barium titanate (BaTiO3) nanoparticles are attractive for increasing the refractive index and dielectric constant of polymer nanocomposites. Current synthesis processes for BaTiO3 nanoparticles require expensive precursors or organic solvents, complicated steps, and long reaction times. In this study, we demonstrate a simple and continuous approach for synthesizing BaTiO3 nanoparticles based on a salt-assisted ultrasonic spray pyrolysis method. This process allows the synthesis of BaTiO3 nanoparticles with diameters of 20-50 nm and a highly crystalline tetragonal structure. The optical properties and photocatalytic activities of the nanoparticles show that they are suitable for use as fillers in various nanocomposites.

In this study, we investigate the optical properties of InP/ZnS core/shell quantum dots (QDs) by controlling the synthesis temperature of InP. The size of InP determined by the empirical formula tends to increase with temperature: the size of InP synthesized at 140oC and 220oC is 2.46 nm and 4.52 nm, respectively. However, the photoluminescence (PL) spectrum of InP is not observed because of the formation of defects on the InP surface. The growth of InP is observed during the deposition of the shell (ZnS) on the synthesized InP, which is ended up with green-red PL spectrum. We can adjust the PL spectrum and absorption spectrum of InP/ZnS by simply adjusting the core temperature. Thus, we conclude that there exists an optimum shell thickness for the QDs according to the size.

In this study, the electroless nickel plating method has been investigated for the coating of Ni nanoparticles onto fine Al powder as promising energetic materials. The adsorption of nickel nanoparticles onto the surface of Al powders has been studied by varying various process parameters, namely, the amounts of reducing agent, complexing agent, and pH-controller. The size of nickel nanoparticles synthesized in the process has been optimized to approximately 200 nm and they have been adsorbed on the Al powder. TGA results clearly show that the temperature at which oxidation of Al mainly occurs is lowered as the amount of Ni nanoparticles on the Al surface increases. Furthermore, the Ni-plated Al powders prepared for all conditions show improved exothermic reaction due to the selfpropagating high-temperature synthesis (SHS) between Ni and Al. Therefore, Al powders fully coated by Ni nanoparticles show the highest exothermic reactivity: this demonstrates the efficiency of Ni coating in improving the energetic properties of Al powders.

Photoelectron-hole separation efficiency plays an important role in the enhancement of the photocatalytic activity of photocatalysts towards the degradation of organic molecules. In this study, TiO2/TiOF2 heterostructured composite powders with suitable band structures, which structures are able to separate photoelectron-hole pairs, have been synthesized using a simple and versatile ultrasonic spray pyrolysis process. In addition, their phase volume fractions have been controlled by varying the pyrolysis temperature from 400 oC to 800 oC. The structural and optical properties of the synthesized powders have been characterized by X-ray diffraction, scanning electronic microscopy and UV-vis spectroscopy. The powder with a phase volume ratio close to 1, compared with single TiOF2 and other composite powders with different phase volume fractions, was found to have superior photocatalytic activity for the degradation of rhodamine B. This result shows that the TiO2/TiOF2 heterostructure promotes the separation of the photoinduced electrons and holes and that this powder can be applicable to environmental cleaning applications.

양이온계 광중합에 적용 가능한 propenyl ether 형태의 단량체들을 mono 및 di-functional alcohol과 allyl bromide의 축합반응으로 합성하였다. 이들 단량체들을 양이온 광개시제와 혼용하여 코 팅조성물을 제조하여 광경화 반응성을 조사하였다. 그 결과 mono propenyl ether 형태인 ((prop-1-en-1-yloxy)methyl)benzene (POMB)는 dipropenyl ether 계인 1,4-bis(prop-1-en-1-yloxy) benzene (BPOB) 비교하여 초기 중합 속도는 10.2로 상대적으로 낮게 나타났으나 1.5mol%의 광개시제 를 포합한 배합물에서는 90초이내에 거의 정량적으로 반응하였다. 또한 긴알킬기를 갖는 술폰산 염계 광개시제들은 단량체들에 빠른 용해 특성을 나타내었고 산성도가 높은 광개시제인 (4-n-decyloxyphenyl)diphenylsulfonium hexafluoroantimonate (DPSA)와 (4-n-decyloxyphenyl) diphenylsulfonium triflate (DPST) 를 사용한 경우 비교적 높은 중합속도와 전환율을 나타내었다.

Bi2Te3 powders are recovered by wet chemical reduction for waste n-type thermoelectric chips, and the recovered particles with different morphologies are prepared using various surfactants such as cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzenesulfonate (SDBS), and ethylenediaminetetraacetic acid (EDTA). When citric acid is added as the surfactant, the shape of the aggregated particles shows no distinctive features. On the other hand, rod-shaped particles are formed in the sample with CTAB, and sheet-like particles are synthesized with the addition of SDBS. Further, particles with a tripod shape are observed when EDTA is added as the surfactant. The growth mechanism of the particle shapes depending on the surfactant is investigated, with a focus on the nucleation and growth phenomena. These results help to elucidate the intrinsic formation mechanism of the rod, plate, and tripod structures of the Bi2Te3 recovered by the wet reduction process.

목적: 비침습적 혈당 분석은 환자의 편의와 감염에 대한 안전성을 위하여 요구된다. 본 연구에서는 금 나노입자의 합성과 응집반응을 활용하여 누액 내 글루코오스의 농도를 정량적으로 분석하고, 이를 종이 미세유체 장치에서 구현하고자 하였다. 방법: 종이 미세유체 장치는 얇은 필터 종이 위에 3mm 직경의 친수성 영역을 형성하는 왁스패턴을 인쇄하여 제작되었다. 완성된 종이 미세유체 장치 위에 염화금 용액 4μl과 누액의 생리적 농도의 글루코오스 용액 5μl를 차례로 떨어뜨려 건조시켰다. 글루코오스 용액이 건조 되면, 개시제(Sodium hydroxide, 60mM)와 발색강화제(Sodium chloride, 100mM)가 포함된 용액 5μl을 떨어뜨려 테스트 영역을 발색시켰다. 테스트 영역의 색상 값은 붉은 색과 노란색의 비율로 환산하여 분석하였다. 결과: 테스트 영역은 글루코오스 농도가 증가함에 따라서 옅은 노란색에서 분홍색으로 변하였다. 또한 농도가 증가함에 따라, 비색분석의 R/Y 비율 값은 선형으로 증가하였다. 이는 글루코오스에 의하여 금 이온이 금 나노입자로 환원됨을 의미한다. 글루코오스의 각 농도에 대한 SEM 이미지를 보면, 글루코오스 농도가 증가함에 따라 종이 표면에 더 많은 금 나노 입자가 흡착된 것을 볼 수 있다. 흡착된 금 나노입자는 20–50nm 직경의 붉은색을 띄는 형태로 형성되었다. 카오트로픽 이온의 첨가는 금 나노입자의 응집을 촉진하여, 보다 진한 발 색양상을 나타내었다. 카오트로픽 이온이 적용된 글루코오스의 분석은 높은 신뢰도 (R² >0.95)를 나타내었다. 결론: 본 연구는 글루코오스와 이온성 요인들에 의해서 금 나노입자가 합성, 응집되는 원리를 이용하여 누액 내에 존재하는 글루코오스의 양을 판정하였다. 이 글루코오스 정량 검출 방법은 기존의 검출 기법과는 다른 새로운 검출 전략으로, 현재 바이오센서 분야에서 각광 받고 있는 금속 나노입자가 활용되었다. 또한 적은 양의 체액을 대상으로 하기 때문에 경제 적인 비색분석으로 활용될 수 있다.

고분자 주쇄가 공액구조를 갖는 고분자는 일반적으로 전기전도성, 비선형광학특성, 기체투과성, 자기성, 광 및 전기발광 등의 다양한 특성을 보인다. 공액구조 고분자의 이러한 특성을 근간으로 유기발광소자, 유기태양전지, FET, Schottky 다이오드, 배터리, 화학센서 등에서 중요한 소재로 이용되어 오고 있다. 지금까지 다양한 형태의 공액 구조 고분자가 설계되었는데, 특히 고분자 전해질은 고분자 구조 내의 많은 부분이 이온화가능하거나 이온성 부분을 갖는 분자량이 큰 물질을 말한다. 본고에서는 공액고분자 전해질의 분자설계와 합성, 더 나아가 이들의 응용에 관한 최근의 연구동향을 제시하였다.

Inorganic phosphors based on ZrO2:Eu3+ nanoparticles were synthesized by a salt-assisted ultrasonic spray pyrolysis process that is suitable for industrially-scalable production because of its continuous nature and because it does not require expensive precursors, long reaction time, physical templates or surfactant. This facile process results in the formation of tiny, highly crystalline spherical nanoparticles without hard agglomeration. The powder X-ray diffraction patterns of the ZrO2:Eu3+ (1-20 mol%) confirmed the body centered tetragonal phase. The average particle size, estimated from the Scherrer equation and from TEM images, was found to be approximately 11 nm. Photoluminescence (PL) emission was recorded under 266 nm excitation and shows an intense emission peak at 607 nm, along with other emission peaks at 580, 592 and 632 nm which are indicated in red.

돼지 난자의 체외성숙 배양액에서 다양한 농도의 육탄당 처리는 난자의 성숙률과 배 발 육능, 세포수 증가에 영향을 주는 것으로 보고되고 있다. 본 연구에서는 육탄당의 일종인 fructose가 돼 지 난자의 체외성숙에 미치는 영향을 조사하였다. 난자의 체외배양액으로는 cysteine, pyruvate, epidermal growth factor, kanamycin, insulin 및 호르몬이 첨가된 porcine zygote medium (PZM)-4 또는 10% 돼지 난포액이 첨가된 PZM-3을 이용하였고 실험설계에 따라 다양한 농도의 fructose 및 5.5 mM의 glucose를 첨가하여 44시간 동안 배 양함으로써 난자의 성숙을 유도하였다. 첫 번째 실험에 서는 1.5, 3.0 및 5.5 mM의 fructose 와 5.5 mM의 glucose가 첨가된 성숙배양액에서 배양된 난자의 성숙률 및 단위발생 후 배 발육능을 조사하였다. 실험 결과 1.5, 3.0 및 5.5 mM fructose를 첨가한 배양액에서 성숙된 난자는 5.5 mM glucose가 첨가된 배양액에서 성숙된 난자와 비교하였을 때 유 사한 핵 성숙 률(81.9-91.5% vs. 94.2%), 단위발생 후 분할률(89.4-92.4% vs. 90.1%), 배반포 발달률 (39.3-41.1% vs. 39.4%) 및 배반포 세포수(30.8-34.2% vs. 31.8%)를 보였다. 두 번째 실험에서, 10% 돼지 난포액이 첨가된 PZM-3 배양액에서 무처리 및 3.0 mM fructose, 5.5 mM glucose 및 3.0 mM fructose와 5.5 mM glucose 병행 첨가 성숙배양액에서 성숙된 난자의 성숙률 및 단위발생 후 배 발 육률을 조사하였다. 실험 결과 3.0 mM fructose (93.1%), 5.5 mM glucose(91.7%) 및 3.0 mM fructose 와 5.5 mM glucose 병행 처리군(93.5%)이 무처리군(74.4%)에 비해 유의적으로(P<0.05) 높은 핵 성 숙률을 보였다. 또한 5.5 mM glucose(90.1%) 및 병행 처리군(97.2%)은 대조군(67.6%)에 비해 유의 적으로(P<0.05) 높은 분할률을 보였다. 배반포 발달률은 3.0 mM fructose(52.6%) 및 병행 처리군 (58.8%) 에서 무처리군(44.4%) 및 5.5 mM glucose (51.0%)에 비해 유의적으로(P<0.05) 증가하였다. 본 실험 결과로 보아 체외성숙 합성배양액 내 fructose 첨가는 glucose와 유사한 수준의 배 발육률 을 보임으로써 glucose를 대체할 수 있는 에너지원으로 이용 가능함을 확인하였다.

철강산업 부생가스 중 파이넥스 공정에서 발생하는 FOG는 CO2 (46.6%) 및 CO (30.3%)로 구성되어 있으며, 이들은 주로 저효율 열원으로 사용되고 있다. 고순도의 CO2와 CO는 화학원료로 사용 할 수 있기 때문에 이들을 효율적으로 분리할 경우 온실가스 절감 및 고부가가치의 제품을 생산할 수 있다. 본 연구에서는 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic (DOCDA)와 4,4'-Oxydianiline (ODA)를 이용하여 선택성이 우수한 DOCDA-ODA 폴리이미드를 합성하였고, 이산화탄소의 투과성을 향상시키기 위해 이산화탄소 친화성이 좋은 폴리에틸렌옥사이드를 DOCDA-ODA에 도입하여 폴리이미드 공중합체를 합성하였다.

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 gas separation properties compared with the membranes prepared by traditional dip-coating seeding.

Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

Applications of nonlinear acoustics are getting popular in the field of nondestructive characterization of material microstructure and damage. Before the nonlinear acoustic technique is fully utilized, it is important to understand the behavior of nonlinear acoustic fields generated by finite amplitude excitation. A two wave mixing technique can be considered and the difference frequency component can be used to determine the nonlinear material properties. One important advantage of using the difference frequency component is known to minimize the source nonlinearity and to acquire low attenuating nonlinear signals. In this paper, the expression for the difference frequency sound beam is derived from the quasilinear theory of the Westervelt equation which includes the material nonlinearity, beam diffraction and material attenuation. Simulation results are presented and the beam properies are discussed in comparison with the behavior of the second harmonic beam fields.

In this study, (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate acrylate was synthesized by reacting (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate with acrylic acid to minimize hardening shrinkage and to improve heat resistance, which are known as disadvantages of photopolymers for 3D printing application. Urethane acrylate was synthesized by reacting 1,3,5-triazine-2,4,6-triamino alcohol, 2-hexylethyl acrylate, and isophorone diisocyanate in order to improve the mechanical properties without deteriorating the heat resistance. The physical properties before and after the synthesis of the acrylate and the mechanical properties when the urethane acrylate was applied were investigated. The reaction progress of the composite was examined by FTIR and 13C NMR. The heat deflection temperature, flexural strength, and surface hardness of the molding were measured. The curing behavior by Photo-DSC ultraviolet irradiation was also examined.