In order to improve the breaking strength and elongation of Polybutylene succinate (PBS) monofilament, the monofilament was produced by blending PBS and Polybutlyne adipate-co-terephthalate (PBAT). The PBS/PBAT blend monofilament was prepared by the melt spinning system, and the weight ratios of the compositions of PBS/PBAT was 100/0, 95/5, 90/10 and 85/15, respectively. The breaking strength, elongation, softness and crystallization of PBS/PBAT blend monofilament were analyzed by using a tensionmeter, softness measurement, X-ray diffractometer in the both dry and wet conditions. The PBS/PBAT blend monofilaments were spun in the take-up velocity of 1.19m/sec under the drawing ratio of 6.8:1 condition. The production volumes of PBS/PBAT blend monofilaments showed 20% less than that of Nylon. The breaking strength of PBS/PBAT blend monofilaments were decreased as PBAT contents increased, while elongation and softness were increased. In case of PBAT content were over 5%, the breaking strength, elongation and softness of PBS/PBAT blend monofilaments were not shown to increase in spite of increasing in PBAT contents. Based on these results, it was possible to make the monofilaments with the maximized physical properties when the PBAT contents at 5%.

In the present work, water-based gold nanofluids were synthesized by the solution plasma processing (SPP). The size distribution and the shape of gold nanoparticles in the nanofluids were investigated using high resolution transmission electron microscopy (HR-TEM). The dispersion stability of gold nanofluids was characterized using zeta potential, as well. The thermal properties of gold nanofluids were measured by utilizing lambda measurement device. Nanofluids containing nanoparticles with in diameter were successfully synthesized. As diameter of nanoparticles decreased, dispersion stability of nanofluids increased and the enhanced ratio of thermal conductivity increased. The nanofluid with nanoparticles of in diameter showed approximately 3% improvement in thermal conductivity measurement and this could be due to the enhanced Brownian movement.

High speed steels (HSS) were used as cutting tools and wear parts, because of high strength, wear resistance, and hardness together with an appreciable toughness and fatigue resistance. Conventional manufacturing process for production of components with HSS was used by casting. The powder metallurgy techniques were currently developed due to second phase segregation of conventional process. The powder injection molding method (PIM) was received attention owing to shape without additional processes. The experimental specimens were manufactured with T42 HSS powders (59 vol%) and polymer (41 vol%). The metal powders were prealloyed water-atomised T42 HSS. The green parts were solvent debinded in normal n-Hexane at for 24 hours and thermal debinded at mixed gas atmosphere for 14 hours. Specimens were sintered in , gas atmosphere and vacuum condition between 1200 and . In result, polymer degradation temperatures about optimum conditions were found at and . After sintering at gas atmosphere, maximum hardness of 310Hv was observed at . Fine and well dispersed carbide were observed at this condition. But relative density was under 90%. When sintering at gas atmosphere, relative density was observed to 94.5% at . However, the low hardness was obtained due to decarbonization by hydrogen. In case of sintering at the vacuum of torr at temperature of , full density and 550Hv hardness were obtained without precipitation of MC and in grain boundary.

Multi shell graphite coated Ag nano particles with core/shell structure were successfully synthesized by pulsed wire evaporation (PWE) method. Ar and (10 vol.%) gases were mixed in chamber, which played a role of carrier gas and reaction gas, respectively. Graphite layers on the surface of silver nano particles were coated indiscretely. However, the graphite layers are detached, when the particles are heated up to in the air atmosphere. In contrast, the graphite coated layer was stable under Ar and atmosphere, though the core/shell structured particles were heated up to . The presence of graphite coated layer prevent agglomeration of nanoparticles during heat treatment. The dispersion stability of the carbon coated Ag nanoparticles was higher than those of pure Ag nanoparticles.

A carbon doped (C-) photocatalyst, which shows good photocatalytic activity to Ultraviolet irradiation and visible irradiation, was successfully prepared by co-grinding of with ethanol or Activated Carbon(C), followed by heat treatment at in air for 60 min. Ethanol and C were used as a representative agent of liquid and solid for carbon doping. Their influence on improving photocatalytic ability and carbon doping degree was studied with degradation of methyl orange and XPS analysis. The product prepared by co-grinding of with Ethanol had Ti-C and C-O chemical bonds and showed higher photocatalytic activity than the product prepared by co-grinding of with C, where just C-O chemical bond existed. As a result, mechanochemical route is useful to prepare a carbon doped photocatalyst activating to visible irradiation, where the solid-liquid operation is more effective than solid-solid operation to obtain a carbon doped .

Ethylene glycol-based Cu nanofluids were prepared by pulsed wire evaporation (PWE) method. The structural properties of Cu nanoparticles were studied by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The average diameter and Brunauer Emmett Teller (BET) surface area of Cu nanoparticles were about 100 nm and , respectively. The thermal conductivity and viscosity of copper nanofluid were measured as functions of Cu concentration and temperature. As the volume fraction of Cu nanoparticles increased, both the enhanced ratios of thermal conductivity and viscosity of Cu nanofluids increased. As the temperature increased, the enhanced ratio of thermal conductivity increased, but that ratio of viscosity decreased.

Hexagonal barium ferrite () nano-particles have been successfully fabricated by spraypylorysis process. precursor solutions were synthesized by self-assembly method. Diethyleneamine (DEA) surfactant was used to fabricate the micelle structure of Ba-DEA complex under various DEA concentrations. powders were synthesized with addition of Fe ions to Ba-DEA complex and then fabricated powders by spray-pyrolysis process at the temperature range of . The molar ratio of Ba/DEA and heat-treatment temperatures significantly affected the magnetic properties and morphology of powders. powders synthesized with Ba/DEA molar ratio of 1 and heat-treated at showed the coercive forces (iHc) of 4.2 kOe with average crystal size of about 100 nm.

The usual ceramic process of mixing and milling in state of oxides ZrO2 and CeO2 was adopted in this study in a wet process to manufacture Ce-TZP. CeO2-ZrO2 ceramics containing 8~20 mol% CeO2 were made by heat treatment at 1250~1500˚C for 5hr. The maximum dispersion point of every slurry manufactured with a mixture of ZrO2 and CeO2 was neat at pH10. A stable slurry with average particle size of 90 nm can be manufactured when it is dispersed with the use of ammonia water and polycarboxylic acid ammonium. The sintered Ce-TZP ceramics manufactured with the addition of CeO2 in a concentration of less than 10 mol% progressed to the fracture of the specimen due to the existence of a monoclinic phase of more than 30% at room temperature. More than 99% of the tetragonal phase was created for the sintered body with the addition of CeO2 beyond 18 mol%, but the degradation of the mechanical properties on the entire specimen was brought about due to the CeO2 existing in a percentage above 3%. Consequently, the optimal Ce-TZP level combined in the oxide state was identified to be 16 mol% of CeO2 contents.

For this paper, we investigated the area specific resistance (ASR) of commercially available ferritic stainless steels with different chemical compositions for use as solid oxide fuel cells (SOFC) interconnect. After 430h of oxidation, the STS446M alloy demonstrated excellent oxidation resistance and low ASR, of approximately 40 mΩcm2, of the thermally grown oxide scale, compared to those of other stainless steels. The reason for the low ASR is that the contact resistance between the Pt paste and the oxide scale is reduced due to the plate-like shape of the Cr2O3(s). However, the acceptable ASR level is considered to be below 100 mΩcm2 after 40,000 h of use. To further improve the electrical conductivity of the thermally grown oxide on stainless steels, the Co layer was deposited on the stainless steel by means of an electroless deposition method; it was then thermally oxidized to obtain the Co3O4 layer, which is a highly conductive layer. With the increase of the Co coating thickness, the ASR value decreased. For Co deposited STS444 with 2 μmhickness, the measured ASR at 800˚ after 300 h oxidation is around 10 mΩcm2, which is lower than that of the STS446M, which alloy has a lower ASR value than that of the non-coated STS. The reason for this improved high temperature conductivity seems to be that the Mn is efficiently diffused into the coating layer, which diffusion formed the highly conductive (Mn,Co)3O4 spinel phases and the thickness of the Cr2O3(S), which is the rate controlling layer of the electrical conductivity in the SOFC environment and is very thin

CoSb3 Skutterudites materials have high potential for thermoelectric application at mid-temperature range because of their superior thermoelectric properties via control of charge carrier density and substitution of foreign atoms. Improvement of thermoelectric properties is expected for the ternary solid solution developed by substitution of foreign atoms having different valances into the CoSb3 matrix. In this study, ternary solid solutions with a stoichiometry of Co1-xNixSb3 x = 0.01, 0.05, 0.1, 0.2, CoSb3-yTey, y = 0.1, 0.2, 0.3 were prepared by the Spark Plasma Sintering (SPS) system. Before the SPS synthesis, the ingots were synthesized by vacuum induction melting and followed by annealing. For phase analysis X-ray powder diffraction patterns were checked. All the samples were confirmed as single phase; however, with samples that were more doped than the solubility limit some secondary phases were detected. All the samples doped with Ni and Te atoms showed a negative Seebeck coefficient and their electrical conductivities increased with the doping amount up to the solubility limit. For the samples prepared by SPS the maximum value for dimensionless figure of merit reached 0.26, 0.42 for Co0.9Ni0.1Sb3, CoSb2.8Te0.2 at 690 K, respectively. These results show that the SPS method is effective in this system and Ni/Te dopants are also effective for increasing thermoelectric properties of this system.

Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (μ-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.

Silicon quantum dots (Si QDs) in a superlattice for high efficiency tandem solar cells were fabricated by magnetron rf sputtering and their characteristics were investigated. SiC/Si1-xCx superlattices were deposited by co-sputtering of Si and C targets and annealed at 1000˚C for 20 minutes in a nitrogen atmosphere. The Si QDs in Si-rich layers were verified by transmission electron microscopy (TEM) and X-ray diffraction. The size of the QDs was observed to be 3-6 nm through high resolution TEM. Some crystal Si and -SiC peaks were clearly observed in the grazing incident X-ray diffractogram. Raman spectroscopy in the annealed sample showed a sharp peak at 516 cm-1 which is an indication of Si QDs. Based on the Raman shift the size of the QD was estimated to be 4-6 nm. The volume fraction of Si crystals was calculated to be about 33%. The change of the FT-IR absorption spectrum from a Gaussian shape to a Lorentzian shape also confirmed the phase transition from an amorphous phase before annealing to a crystalline phase after annealing. The optical absorption coefficient also decreased, but the optical band gap increased from 1.5 eV to 2.1 eV after annealing. Therefore, it is expected that the optical energy gap of the QDs can be controlled with growth and annealing conditions.

Polyvinyl acetate (PVAc) prepared by emulsion polymerization has broad applications for additive such as paint binder, adhesive for wood and paper due to its low glass transition temperature which help to plasticize substrate resins. Since emulsion polymerization has a disadvantage that surfactant and ionic initiator degrade properties of the product polymer, poly (vinyl acetate-eo-ethyl acrylate) (VAc-EA) was synthesized using potassium persulfate as catalyst and polyvinylalcohol (PVA) as protective colloid to prevent the degradation. The copolymer latex product was internally plasticized and has enhanced adhesion, water resistance during VAc-EA emulsion polymerization. No coagulation and complete conversion occur with the reactant mixture of 10 mmol/L potassium persulfate, 10 mmol/L poly ( vinyl alcohol) (PVA 17). As the concentrations of PVA increase, the viscosity becomes increase.

EAF dust which is contained around 30% of zinc, 15% of iron and 3% of lead individually, is chemically treated by ammonium chloride, ammonia water, ammonia gas and carbon dioxide, and also tested and identified the ratios of the recovery of In by applied the variations of particle size, pH and heating temperature as well, in order to getting optimized recovery of the In metal after performing all of those processes. Experimental results showed that the rate of Zn recovery is 97% when the mixture of 1.3 of NH4Cl/EAF is heated to the temperature of 400℃ and leached by water, and 95% recovery of In when ammonia gas and carbon dioxide is added simultaneously and adjust the 9.5 of pH to the same mixture above. For the purpose of remove the impurities in the mixed sample, which is prepared by the two samples, indicated above showing as the ratio of 95% and 97% recovery, in case of applied the cementation process to it, and also by electrolytic process, produced the In plate of 95~97%, and acquired 99-99.5% of In metal ingot finally by applied the heating process at 470~500℃.

Poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA) 가지형 공중합체를 합성한 후, 이를 이용하여 80℃에서 열적으로 환원하여 은 나노입자를 제조하였다. 반응 시간을 바꿈에 따라 다양한 구조의 은 나노입자를 제조하는데 성공하였다. 1시간 정도의 짧은 반응 시간에서는 가지형 공중합체의 미세 상분리 구조를 크게 변화시키지 않고 5 nm 크기의 작은 은 나노입자가 생성되었다. 5시간 정도의 중간 반응 시간에서는 30 내지 50 nm 정도의 크기를 갖는 은 나노입자가 생성되었다. 18시간 정도의 긴 반응 시간에서는, 은입자가 뭉친 허리케인 모양의 은 집합체가 관찰되었다.

기업은 경쟁우위를 확보하고 지속적인 성장을 이끌기 위해 기술개발을 위한 R&D 투자 및 혁신활동에 집중해야 한다. 그러나, 기업의 이러한 활동은 언제나 성공하는 것이 아니며, 기술개발의 위험도가 높고 이익의 전용가능성이 낮거나 기업내부의 역량이나 자원이 부족할 경우, 기업의 혁신활동은 저해되기 쉽다. 이러한 상황에서 외부파트너와의 연구협력은 이러한 문제들을 해결할 수 있는 좋은 전략이라고 할 수 있다. 본 연구에서는 한국의 제조업체를 대상으로 각 기업이 기술혁신을 위해 연구협력을 선택할 때 어떤 요인들이 연구 협력결정에 영향을 미치는지를 분석하였다. 이를 위해서 과학기술정책연구원(STEPI)에서 수행한 기술혁신조사 데이터를 활용하였으며, 분석결과 기업의 규모가 클수록, 과거의 연구협력경험이 많을수록, 하이테크 기업에 속한 기업일수록 연구협력을 통해 제품혁신을 수행하는 것으로 나타났으며, 혁신실패의 위험성, 자금조달의 어려움, 조직내부의 역량부족, 외부환경요인 등과 같은 혁신활동저해요소들은 제품혁신활동 수행시 외부와의 연구협력에 영향을 미치지 못하는 것으로 나타났다.

본 연구는 양성전해질막의 금속이온 특성을 조사하기 위하여 Taurine (TAU)막을 제조하였다. 제조방법으로는 방사선조사법에 의한 Glycidyl methacrylate (GMA)의 중공사막 표면위에 고정시키고, 이후 Taurine의 염기성 부분인 -NH2기(amine fuction)와 GMA의 glycididyl의 개환 반응을 통하여 안정된 막을 형성하도록 하였다. 한편 TAU막과 비교를 위해 GMA가 고정된 중공사 막에 Sodium sulfite로 화학적 결합을 형성 SS막을 제조하였다. 이렇게 제조된 TAU막의 타우린 밀도가 높아져도 투과유속은 0.9 m/h로 변화 없으나, SS막은 술폰산기의 밀도가 높아짐에 따라 투과유속이 급격히 감소하는 것을 나타내었다. 타우린 밀도가 0.8 mmol/g인 막을 사용한 결과 금속이온의 량은 Cu > Cd > Mg > Sb > Pb의 순으로 나타내었다. 전반적으로 타우린막은 전화율과 밀도의 증가에 따라 많은 양의 금속이온 흡착과 높은 투과유속을 나타내었다.

본 연구에서는 지하수 내 질산성 질소 이온을 제거하기 위해 전기투석 공정에 적용가능한 음이온교환 복합막을 제조하였다. 막의 제조를 위해 기본 단량체로 vinyl benzylchloride (VBC)와 styrene (ST), 가교제로 divinylbenzene (DVB), 그리고 개시제 α,α-azobis(isobutyronitrile) (AIBN)으로 이루어진 단량체 용액에 구조적으로 단단한 fabric을 함침한 후 열중합 가교시켜 복합막을 생성한 다음 trimethylamine (TMA)과 acetone을 이용해 음이온 교환기(-N+(CH3)3)를 함유하는 복합막을 제조하였다. 제조한 아민화 완료된 poly(VBC-ST-DVB)/fabric 복합막들의 특성을 알아보고자 막의 함수율, 이온교환 용량(IEC) 및 전기저항을 아스톰사의 상용화 음이온교환막(AMX)과 비교 조사하였다. 그 결과 제조된 막들은 아스톰사의 AMX보다 높은 IEC와 낮은 전기저항 특성을 나타냈다. 또한 제조된 음이온막을 전기투석장치에 설치하여 NaNO3, MgSO4, NaF (각각 100 mg/L) 등의 이온제거 실험을 60분 수행한 결과 NaNO3뿐만 아니라 MgSO4, NaF 이온 등도 1 mg/L 이하까지 잘 제거되었음을 확인할 수 있었으며, 전기투석 15분 전후로 하여 이온전도도값의 변화가 거의 없는 것으로 보아 전기투석 특성을 실험한 결과 전기투석 약 15분 이내에 이온이 제거되었음을 확인할 수 있었다.

다양한 형태의 Polysulfone 막을 MBR공정에 적용하기 위해 제조하였다. 특히 제조공정에 있어서 여러 형태의 에테르형 알코올을 사용 도프용액에 첨가시킴으로써, 공경크기에 미치는 영향력을 조사하였다. 본 연구에서는 공경의 크기는 첨가된 첨가제의 끓는점에 의한 영향력보다는 그들 자체(첨가된 첨가제)의 분자구조에 의한 확산에 더 큰 영향력을 받고 있음을 보여주었다. 분자적으로 methoxy (CH3-O-) < secondary propanol (-CH2-CH(OH)-CH3) < ethoxy (CH3-CH2-O-)의 순으로 공경크기가 커지고 그에 따라 순수투과도 또한 커짐을 보여주었다. 이러한 현상은 첨가된 용매가 분자적으로 ether형 알코올의 bulky한 정도에 따라 공경의 형성이 다른 형태로 나타나고 있음을 보여주고 있다. 본 연구에서는 다양한 형태의 ether형 alcohol를 통하여 바라고자하는 형태(평균 pore size 0.1~0.4 μm)의 MF (microfiltration)막을 제조할 수 있었으며, MBR (membrane bio-reactor)에 적용한 결과 2달 동안 안정되게 운전되었다.