본 연구는 막걸리 제조 시 아로니아의 첨가 방법을 달리하 여 제조한 후, 발효하면서 항산화 활성 및 이화학적 품질특성 을 분석하였다. 아로니아는 생과와 마쇄한 형태로 첨가하였 고, 쌀 함량의 10%, 30% 그리고 50%로 하였다. 막걸리의 pH 는 발효 초기에 생과를 첨가한 시료가 3.9~4.2로, 마쇄하여 첨 가한 시료(3.6~3.9)보다 높았고, 발효가 진행되면서 생과로 첨가한 경우는 pH가 낮아지다가 다시 증가하는 경향성을 보 였다. 총산의 경우는 초기 발효에는 생과보다 마쇄한 시료에 서 더 높게 나타났고, 발효가 진행될수록 총산의 함량이 증가 하였다. 환원당 함량은 발효가 진행되며 대부분의 시료에서 감소하였다. 에탄올 함량은 1단 담금 시 11.4%로 나타났고, 2단 담금 6일 후에는 10~15%였으며, 특히, 아로니아를 50% 첨가한 실험구는 1단 담금 시 보다 낮은 에탄올 함량을 보였 으며, 마쇄하여 첨가할수록 더 낮은 알코올함량을 보였다. 색 도 중 a값(적색도)을 비교했을 때 생과 사용 시 천천히 a값이 높아져 마지막 날에는 생과 처리구 간 유의적으로 차이가 났 지만, 마쇄한 경우는 처음부터 마지막 발효까지 높은 a값을 가져 생과를 처리한 경우보다 높게 나타났다. 총 폴리페놀함 량 측정과 DPPH radical 소거능 측정 결과는 아로니아 첨가량 이 증가할수록 함께 증가하였는데, 생과첨가군의 경우 초기 에는 낮은 값을 가지다가 발효가 진행하며 급속히 증가하였 고, 마쇄첨가군에서는 초기에서부터 높은 값을 가졌다. 또한 아로니아를 30% 첨가하여도 50%를 첨가한 것과 같이 뛰어난 항산화 활성을 나타내었다. 관능검사는 생과 30%를 첨가 한 시료가 색, 쓴맛, 전체적 기호도에서 높아 관능적 만족도 가 우수한 것으로 나타났다. 이상의 결과로 아로니아를 첨가 한 기능성 막걸리의 특성을 보았을 때 아로니아를 마쇄한 형 태보다 생과 형태로 30%를 첨가하는 것이 관능적 특성과 항 산화 활성을 고려하였을 때 가장 적합한 것으로 나타났다.

스크린 인쇄 방식을 통해 ZnS기반의 AC 분산형 EL 소자를 제작하였다. 유전체층 재료로 BaTiO3를 사용하였다. 소자의 경우는 쉽게 변수를 조정할 수 있는 수동 스크린 인쇄 방식을 사용하여 최적의 조건으로 제작하였다. TiO2는 내산성, 내알칼리성이 좋아 인체에 무해하기 때문에 광촉매제로 많이사용되고 있다. 기판은 투명전극인 ITO glass와 유연한 ITO PET film의 두가지 방식으로 제작하였다. 본연구에서는 형광체층에 TiO2의 첨가량을 변화시킨 EL소자를 SEM과 XRD를 통하여 구조를 분석하고, 발광 스펙트럼을 통하여 분석하였다. 그리고 TiO2의 첨가량이 증가할수록, 발광효율이 증가하는 것을 알 수 있었다.

Purpose : UV-block effect of soft contact lens polymerized and with 2,4-dihydroxybenzophenone in the basic hydrogel contact lens material was evaluated. and also the influence of sterilization condition on change of optical properties was analyzed. Methods: 2,4-dihydroxybenzophenone as additive with 2-hydroxyethyl methacrylate and the initiator AIBN were used for thermal copolymerization. The mixture was heated at 100 ℃ for 50 mins to produce the hydrogel contact lens. and they are heated at 115 ℃ for 3 hour for sterilization. Results: The optical properties of produced contact lens including 2,4-dihydroxybenzophenone showed that the UV-A transmittance was 28~36% and the UV-B transmittance was 10~18%. and Also, in case of sterilization situation, the results showed that the UV-A transmittance was 5~17% and the UV-B transmittance was 4~16%, respectively. Conclusions: After sterilization of produced contact lens, UV-block effect of soft contact lens including benzophenone group was increased.

The effects of the mixing of an active material and a conductive additive on the electrochemical performance of an electric double layer capacitor (EDLC) electrode were investigated. Coin-type EDLC cells with an organic electrolyte were fabricated using the electrode samples with different ball-milling times for the mixing of an active material and a conductive additive. The ball-milling time had a strong influence on the electrochemical performance of the EDLC electrode. The homogeneous mixing of the active material and the conductive additive by ball-milling was very important to obtain an efficient EDLC electrode. However, an EDLC electrode with an excessive ball-milling time displayed low electrical conductivity due to the characteristic change of a conductive additive, leading to poor electrochemical performance. The mixing of an active material and a conductive additive played a crucial role in determining the electrochemical performance of EDLC electrode. The optimal ball-milling time contributed to a homogeneous mixing of an active material and a conductive additive, leading to good electrochemical performance of the EDLC electrode.

Carbonate-type organic electrolytes were prepared using propylene carbonate (PC) and dimethyl carbonate (DMC) as a solvent, quaternary ammonium salts, and by adding different contents of 1-ethyl-3-methyl imidazolium tetrafluoroborate (EMImBF4). Cyclic voltammetry and linear sweep voltammetry were performed to analyze conducting behaviors. The surface characterizations were analyzed by scanning electron microscopy method and X-ray photoelectron spectroscopy. From the experimental results, increasing the EMImBF4 content increased the ionic conductivity and reduced bulk resistance and interfacial resistance. In particular, after adding 15 vol% EMImBF4 in 0.2 M SBPBF4 PC/DMC electrolyte, the organic electrolyte showed superior capacitance and interfacial resistance. However, when EMImBF4 content exceeded 15 vol%, the capacitance was saturated and the voltage range decreased.

In this study, the porous ceramic filter was developed to be able to remove both dust and hazardous gas contained in fuel gas at high temperature. The porous ceramic filters were fabricated and used as a catalyst support. And the effects have been investigated such as the mean particle size, organic content and addition of foaming agent on the porosity, compressive strength and pressure drop of ceramic filters. With the increase of mean powder size and the organic content for the cordierite filter, the porosity was increased, but the compressive strength and pressure drop were decreased. From the results of the research, the optimum condition for the fabrication of ceramic filters could be acquired and they had the porosity of 58%, the compressive strength of 13.4 MPa and the pressure drop of 250 Pa. It was expected that this ceramic filter was able to be applied to the glass melting furnace, combustor, and dust/toxic gas removal filter.

본 연구에서는, 유기용매를 사용하지 않는 친 환경적인 건식 공정과 초임계 공정을 이용한 Thin-multiwalled carbon nanotube (TWNTs)/아민계 에폭시 첨가제의 복합체 제조에 관하여 연구를 하였다. 제조된 TWNTs/아민계 에폭시 첨가제의 복합체는 우레탄기반의 비스페놀 A 타입의 에폭시 레 진의 경화제로 사용하였다. TWNTs/아민계 에폭시 첨가제의 복합체를 경화제로 사용하여 제조된 에폭 시 레진의 열적 성질을 Dynamic mechanical analysis (DMA)를 이용하여 분석 하였으며, 메트릭스상의 carbon nanotube 의 높은 분산성은 SEM을 통하여 확인 하였다. 그 결과, 초임계 공정을 이용하여 제 조된 에폭시 레진의 열적 성질과 매트릭스내의 carbon nanotube 분산성이 건식 공정을 사용 하였을 때 보다 더욱 증가된 결과를 확인 할 수 있었다

Intrigued by the recent emergence and success of low-cost airlines, which use the additive option price framing (as opposed to the subtractive option price framing used by the traditional full-service airlines), we attempted to develop and empirically test a theoretical model that can help better understand the success of this innovative pricing practice for optional services. Drawing on the prospect theory and the loss aversion and endowment effect theory, we argue that option price framing affect customer responses such as perceived risk, perceived price fairness and affect. Further, we propose interaction effects between option framing and product type (utilitarian vs. hedonic) on perceived risk. Using a quasi-experimental design, we constructed four scenarios (2 option price framings x 2 product types). We administered the scenario-based survey among part-time MBA students (full-time managers). Analysis results of 132 responses demonstrated that customer responses in perceived risk, perceived fairness and affect were more favorable in the additive option framing, which in turn led to higher purchase intention. Further, these effects were stronger for utilitarian products. For hedonic products, no difference in perceived risk was observed between the two option price framings. Consequently, our study offered an explanation for when and why the additive option price framing might work better.

목 적: 본 연구는 습윤성 물질을 포함한 기본적인 하이드로젤 콘택트렌즈 재료에 silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(SiNc)를 첨가하여 친수성 콘택트렌즈의 물리적 및 광학 특성을 측정하였다. 또한 제조된 고분자의 자외선 투과율과 접촉각을 측정하여 SiNc의 안의료용 렌즈 소재로의 활용도, 특히 습윤성을 향상시키는 안의료용 고분자로서의 활용도에 대해 알아보았다. 방 법: 친수성 하이드로젤 렌즈 제조를 위해 2-hydroxyethyl methacrylate (HEMA), N-vinyl-2-pyrrolidone (NVP), methylmethacrylate (MMA), 교차결합제인 ethylene glycol dimethacrylate (EGDMA) 그리고 개시제인 azobisisobutyronitrile (AIBN)을 사용하여 공중합 하였다. 또한, SiNc는 첨가제로 사용되었다. 중합 후 제조된 콘택트렌즈 재료의 함수율, 굴절률, 접촉각 및 분광투과율 등의 물리적 특성을 측정하였다. 결 과: 생성된 하이드로젤 렌즈 고분자의 물리적 특성을 측정한 결과, 함수율 38.12 ~ 37.98%, 굴절률 1.434 ~ 1.435, 접촉각 34.33 ~ 62.91°그리고 분광투과율의 경우 34.6 ~ 91.0%의 범위로 나타났다. 또한 SiNc를 첨가한 조합에서 자외선 투과율이 크게 감소하였으며, 습윤성은 증가하였다. 결 론: 습윤성 물질 및 SiNc를 첨가하여 제조된 안의료용 고분자 재료는 자외선 차단 및 습윤성이 우수한 하이드로젤 콘택트렌즈를 제조하기 위한 재료로 유용하게 사용될 것으로 기대된다.

Purpose: Various studies have been conducted on macromolecular materials that not only have basic characteristics but also UV-blocking capabilities. Here we report tinted hydrogel contact lens containing titanium silicon oxide nanoparticles. This study also showed the physical and optical effects of 4-iodoaniline on contact lenses, which affect UV transmissibility. Methods: Titanium silicon oxide nanoparticles were used as additives. HEMA, MA, MMA, 4-iodoaniline and a cross-linker EGDMA were copolymerized in the presence of AIBN as an initiator. The physical properties such as water content, refractive index, contact angle, spectral transmittance of produced contact lenses were measured. Results: Measurement of the physical characteristics of the copolymerized material showed the water content of 38.68~35.01%, refractive index of 1.4350~1.4418, contact angel of 34.15~57.25° and spectral transmittance of 1.0~84.8%. Also, the transmittance for UV light was reduced significantly in combinations containing titanium silicon oxide nanoparticles. Conclusions: Tinted hydrogel contact lens material containing titanium silicon oxide nanoparticles is expected to be able to be used usefully as a material for UV-block hydrogel contact lens.

목적: 본 연구는 2-fluoro-4-pyridinecarboxylic acid 및 6-fluoropyridine-3-carboxylic acid를 사용하여 친수성 하이드로젤 콘택트렌즈 재질을 중합하고 제조된 친수성 콘택트렌즈의 물리적, 광학적 특성을 분석하여 이들 물질들의 콘택트렌즈 재료로서의 활용도를 알아보았다. 방법: 본 연구는 카르복시산 및 불소로 치환한 피리딘을 2가지 이상 첨가제로 사용하여 친수성 콘택트렌즈의 기본적인 재질인 HEMA(2-hydroxyethyl methacrylate), AA(acrylic acid), MMA(methylme-thacrylate), 개시제인 AIBN(azobisisobutyronitrile), 그리고 교차결합제인 EGDMA(ethylene glycol dimethacrylate)를 사용하여 공중합하였다. 결과: 생성된 고분자의 물리적 특성을 측정한 결과, 굴절률 1.4348-1.4300, 함수율 33.69~35.84%, 가시광선 투과율 89.6~90.8%, 인장강도 0.2292-0.3344kgf 그리고 접촉각의 경우 76.05°~50.95°의 분포를 나타내었다. 또한 황색포도상구균에 대한 항균실험 결과 2-fluoro-4-pyridinecarboxylic acid 및 6- fluoropyridine-3-carboxylic acid를 5% 첨가했을 때 항균효과가 다소 있는 것으로 나타났다. 결 론: 본 실험 결과, 2-fluoro-4-pyridinecarboxylic acid 및 6-fluoropyridine-3-carboxylic acid를 첨가하여 제조된 친수성 콘택트렌즈는 기본적인 콘택트렌즈 물성을 만족하였으며 우수한 습윤성과 항균성 및 자외선 차단 콘택트렌즈로 활용될 수 있을 것으로 판단된다.

CSA, a cement mineral compound that is mainly composed of 3CaO·3Al2O3·CaSO4, generates ettringite as a hydration product after a reaction with glass (lime), gypsum and water to speed up the hardening process and enhance the strength and degree of expansion. When used as a cement admixture, there is increased production of ettringite, which can improve the initial strength in the first three days and ameliorate the reduction in the initial strength caused by the use of fly ash in particular. In this study, a hydrate analysis was performed using XRD and SEM after substitution with fly ash (30%) and CSA (8%) with the goal of observing the effect of CSA on the initial strength of a cement mixture containing fly ash. The results of the analysis showed that an addition of CSA promoted the production of ettringite and improved the initial strength, resulting in the generation of hydrates, which can effectively enhance the long-term strength of these materials.

In the livestock feed industry, antibiotics are used to prevent disease, promote growth rate, and improve feed efficiency. However, antibiotic supplementation to animal feed results in increased bacterial resistance to antibiotics as well as antibiotic residues in animal products, which can negatively affect human health. Therefore, alternative sources of antibiotics are need- ed. Probiotics as an alternative to antibiotics in animal feed have been shown to increase feed efficiency and growth rate by improving microbial balance. Further, Bacillus sp. produces a wide spectrum of antibacte- rial peptides. The present study was conducted to investigate the effects of dietary supplementation with CS-32 on safety, growth rate, and feed efficiency. Antibacterial substance (5697.9 molecular weights) produced by CS-32 was isolated and purified from culture broth. Moreover, the results of minimal inhibi- tory concentration (MIC) test confirmed the excellent antibacterial effect of CS-32. In vivo, 0.1% and 1% CS-32 were fed to broiler chickens for 28 days. Feed efficiency was slightly higher in groups of chickens supplemented with 0.1% and 1% CS-32 than those of the control group. CS-32 had no significant effect on necropsy findings, hematology, or serum biochemistry, and there was no mortality. These results suggest that CS-32 among various biologically active substances may be safe and effective as a feed additive to improve growth rate and feed efficiency.

This study shows an air-purification test by the UV lamp on which TiO2 catalyst is deposited with glass fiber in the reactor chamber. This test was based on the fundamental data of air-purifier as assessing a removing ability on various contaminants such as CH3COOH, NH3, NO and SO2 as variation of the TiO2 coating, the wave of UV lamp, and the additive CaO. As a result, the highest decomposing removal ratio was shown when 5-times coated glass fiber was used. It can be due to the recombination reaction of electrons and electron-hole in the loaded CaO. Thus, the decomposing removal ratio increased as the recombination ratio decreased. In addition, it was confirmed that the decomposing removal ratio lowered when CaO was considerably deposited because it hided the lamp of OH-1 radical.

PURPOSES : The purpose of this study is to evaluate of field application and laboratory performance of warm-mix asphalt (WMA) according to the dosage rate of organic-based WMA additive. METHODS: Three asphalt mixtures, i.e., hot mix asphalt (HMA), WMA with the dosage rate of 1.5%, WMA with the dosage rate of 1.0%, were sampled from the asphalt plant when the field trial project were constructed. With these mixtures, the laboratory testings were performed to evaluate the linear viscoelastic characteristics and the resistance to moisture, rutting and fatigue damage. RESULTS : From the laboratory test results, it was found that the WMA with the reduced dosage rate of additive would be comparable to HMA and WMA with the original dosage rate in terms of the dynamic modulus, tensile strength ratio, rutting resistance. However, the fatigue reisistance of WMA with the reduced dosage rate was slightly worse but it should be noted that the fatigue performance is necessarily predicted by combining the material properties and pavement structure. CONCLUSIONS: Through the field construction and laboratory testings, the dosage rate of organic-based WMA additive could be reduced from 1.5% to 1.0% without the significant decrease of compactability and laboratory performance. The long-term performance of the constructed pavement will be periodically monitored to support the findings from this study.

PURPOSES: The liquid-type chemical warm-mix asphalt (WMA) additive has been developed. This study evaluates the basic properties of the additive and the mechanical properties of WMA asphalt and mixture manufactured by using the newly developed chemical additive. METHODS: First, the newly developed WMA additive was applied to the original asphalt by various composition of additive components and dosage ratio of additive. These WMA asphalt binders were evaluated in terms of penetration, softening point, rotational viscosity, and PG grade. Based on the binder test results, one best candidate was chosen to apply to the mixture and then the mechanical properties of WMA mixture were evaluated for moisture susceptibility, dynamic modulus, and rutting and fatigue resistance. RESULTS : According to the binder test, WMA asphalt binders showed the similar properties to the original asphalt binder except the penetraion index of WMA additive was a little higher than original binder. From the Superpave mix design, the optimum asphalt content and volumetric properties of WMA mixture were almost the same with those of hot mix asphalt (HMA) mixture even though the production and compaction temperatures were 30℃ lower for the WMA mixture. From the first set of performance evaluation, it was found that the WMA mixture would have some problem in moisture susceptibility. The additive was modified to improve the resistance to moisture and the second set of performance evaluation showed that the WMA mixture with modified chemical additive would have the similar performance to HMA mixture. CONCLUSIONS : Based on the various laboratory tests, it was concluded that the newly developed chemical WMA additve could be successfully used to produce the WMA mixture with the comparable performance to the HMA mixture. These laboratory evaluations should be confirmed by applying this additive to the field and monitoring the long-term performance of the pavement, which are scheduled in the near future.

PURPOSES : The main purposes of this study are to examine the influences of polyethylene wax-based WMA additive on the optimum asphalt content of warm-recycled asphalt mixture based on the Marshall mix design and to evaluate performance of warm-recycled asphalt mixture containing 30% RAP with polyethylene wax-based WMA additive. METHODS: Physical and rheological properties of the residual asphalt were evaluated in terms of penetration, softening point, ductility and performance grade (PG) in order to examine the effects of polyethylene wax-based WMA additive on the residual asphalt. Also, To evaluate performance characteristics of the warm-recycled asphalt mixtures using polyethylene wax-based WMA additive along with a control hot-recycled asphalt mixture, indirect tensile strength test, modified Lottman test, dynamic immersion test, wheel tracking test and dynamic modulus test were conduced in the laboratory. RESULTS : Based on the limited laboratory test results, polyethylene wax-based WMA additive is effective to decrease mixing and compacting temperatures without compromising the volumetric characteristics of warm-recycled asphalt mixtures compared to hot-recycled asphalt mixture. Also, it doesn't affect the optimum asphalt content on recycled-asphalt mixture. All performance test results show that the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is similar to that of a control hot-recycled asphalt mixture. CONCLUSIONS: Overall, the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is comparable to hot-recycled asphalt mixture.

PURPOSES : This study is to develop a method to evaluate the compaction effects of asphalt binders using WMA additives and compare their compaction effects on two types of WMA additives, two types of testing temperatures, and three types of asphalt film thicknesses. METHODS : This study is based on laboratory experiments and rheological analysis of the experimental results. Testing materials are aggregate disks, asphalt, and WMA additives. The main testing method is the stress sweep test by using dynamic shear rheometer (DSR). In addition, the testing parameters obtained from the stress sweep results to evaluate lubrication effects are complex modulus and LVE-Limit. RESULTS : At both the first compaction condition (110℃, 0.3mm) and second compaction condition (80℃, 0.2mm) assumed, LEADCAP showed better compaction effects than Sasobit. CONCLUSIONS : The temperature 30℃ lower than general compaction temperatures can provide a better sensitivity for the evaluation of compaction effects. If a testing temperature and film thickness are grouped for the proper compaction conditions in the testing results, the compaction performance of each WMA additive can be more clearly discriminated in the grouped testing results matched with the grouped conditions.

In this study, STS 316L powders with 3 wt.% Cu and 1 wt.% Sn known as corrosion-resistance reinforce- ment elements, are prepared to make different kinds of specimens, in which, 3 wt.% Cu and 1 wt.% Sn are added in different forms by mixing, alloying and fully alloying. After sintering in the same condition, the corrosion resistance, wear resistance and their mechanical properties of specimens are tested respectively. According to the comparison, STS 316L specimen sintered at 1270o C showed the most excellent mechanical property: HRB 78 (hardness), 1130.7 MPa (RCS), 26.6% (Fraction Wear), It was similar with the specimen made of STS316L and fully alloyed Cu and Sn pow- ders, meanwhile, the latter one appears the best corrosion resistance, 75hrs-salt immersion test results. In addition, the specimens with Cu and Sn powders additive showed relatively worse wear resistance in compared with STS316L spec- imen.