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        검색결과 2,609

        1541.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가교에 관한 리뷰논문으로 특허의 다수는 의료용이다. 조직공학용 지지체나 약물전달용 매체로 쓰이는 고분자의 가교는 세포 무독성, 제 자리 겔 형성성이 있는 가교반응을 중시하고 있다. 가교를 탄성률, 내약품성, 내열성의 증대 목적 외에 가교부위에 금속 흡착성, 방오성, 항균성, 이온교환성 등의 기능을 부여하고 있다. 환경의 자극에 응답하는 스마트 가교, 환경을 고려한 광 가교, 물리적 가교, 효소가교, 천연물 가교, 수성가교가 연구되고 있다. 120세 수명을 목표로 의용재료의 발전에 고분자 소재의 개발도 필수적이다. 가교를 통한 고분자의 기능성 부여 및 물성 강화도 더욱 섬세하게 될 것이다. 고분자 가교물 중의 중요한 분야를 점하는 히드로젤은 주사용 제자리 겔 형성성의 개선 방향으로 전개될 것이다. 코팅용 고분자 가교제는 작업자, 작업환경을 고려하여 저독성-무독성의 가교제, 낮은 에너지에서 가교되는 에너지 절약형 가교제가 개발될 것이다.
        4,600원
        1542.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        금속 주조시 사용되는 탄소이형제를 카본블랙과 점증제 겸 알데하이드 화합물의 경화제로 사용될 수 있는 수용성 고분자인 잔탄검(X-gum), 카르복시메틸셀룰로오스(CMC)을 혼합하여 제조하였다. 이 때 카본블랙의 안정한 분산을 위하여 0.25 wt%의 X-gum 또는 1.0 wt%의 CMC가 적당하였다. 1.0 wt% 보다 낮은 농도의 CMC를 사용했을 경우 카본블랙이 매우 쉽게 층분리되었다. 유리판에 대한 부착력은 경화제와, 구르탈알데하이드 및 사슬연장제인 올리고당의 양에 비례하였으며. X-gum으로 제조된 탄소 이형제는 CMC를 이용해 제조된 것보다 유리에 대한 부착력이 우수하였다. 결과적으로 본 실험의 최적 조건에서 제조된 탄소이형제는 친환경적으로 주조시에 적용할 수 있을 것으로 판단된다.
        4,000원
        1543.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 다양한 시설내에 적은 농도의 CO2 제거를 위한 선택적 CO2 흡수능력을 향상시킨 흡착제의 효율평가에 관한 것이다. 직경 4mm의 구형 흡착제는 시판용 제올라이트에 첨가제, 물, 바인더, LiOH를 섞어 제조하였다. 칼럼테스트에서 400분 이내에 90% 이상의 CO2흡착효율을 나타내었고, 흡착필터모듈 흡착능력을 평가하기 위해 회분식과 연속식타입의 챔버테스트가 시행되었다. 회분식테스트에서 30분 이내에 약 92%의 CO2가 제거되는 것을 확인하였다. 연속식테스트에서 30분 이내 70%의 CO2가 제거효율을 보였으며, 2,500ppm 이상의 CO2가 제거되는 것을 확인하였다. 재현성테스트를 수차례 수행한 결과 15일동안 1,000ppm 이상의 CO2가 연속적으로 제거됨을 보였다. TGA 분석법을 이용한 흡착량 분석에서 흡착제 g당 5.0mmol의 CO2를 흡착하는 것으로 나타났다. 본 연구에서 개발된 흡착제는 상온에서 저농도 CO2 실내환경에 적용가능한 것으로 판단된다.
        4,300원
        1544.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Squid ink was added to the low salt fermented squid by 4% of concentration and ripened at 10℃ for 6 weeks and at 20℃ for 28 days. The effect of the squid ink on the titrable acidity and free amino acids of low salt fermented squid were investigated. The results are as follows; The titrable acidity in the salt fermented squid without addition of the squid ink was continuously decreased except for the salt fermented squid with 9% salt content till the latter stage of the ripening, had larger decreasing range than treatment groups. Seeing the composition of free amino acid, the major amino acids are proline, arginine, glutamic acid. leucine and glycine.
        4,000원
        1545.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrotreated biodiesel(HBD) is paraffinic bio-based liquid, with the chemical structure CnH2n+2, originating from vegetable oil(the process can also be applied to animal fat). The oil or fat is treated in a number of process, the most important being hydrogenation, in order to create a bio-based liquid diesel fuel. During the hydrogenation, oxygen is removed from the triglyceride and converted into water. Propane is formed as a by product and can be combusted and used for energy production. HBD can be used in conventional diesel engines, pure or blended with conventional diesel, due to its similar physical properties to diesel. This study reports the quality characteristics with chemical and physical properties as an alternative diesel fuel. Especially, HBD showed higher cetane value and number than FAME, and it is consisted of C15 - C18 n-paraffinic compounds. We also describes quality characteristics of HBD blends(2, 5, 10, 20, 30, 40, 50 vol%) in automotive diesel. HBD blends(max. 20 vol%) were the limit by the Korean specification due to poor low temperature characteristics.
        4,000원
        1546.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.
        4,000원
        1547.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polymer electrolyte membrane fuel cell (PEMFC) performance degrade when sulfur dioxide is present in the fuel hydrogen gas, this is referred as SO2 poisoning. This paper reveals SO2 poisoning on PEMFC cathode part by measuring electrical performance of single cell under 1 ppm and 5 ppm on SO2 gas operating. The security of SO2 poisoning depended on SO2 concentration under the best operating conditions(65℃ of cell temperature and 100% of relative humidity between anode and cathode). SO2 adsorption occured on the surface of catalyst layer on membrane electrode assembly (MEA), In addition, MEA poisoning by SO2 was cumulative but reversible. After poisoning within 5 ppm SO2 for 1hr, the electrical performance of PEMFC was found to recover up to about 93% by cyclic voltametry scan.
        4,000원
        1548.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        N-(fluorodichlomethylthio) phthalimide-silver complexes were prepared and investigated the antimicrobial activity on rubber mat manufactured with waste rubber. We are exposed to harmful bacteria and fungi all the time. We manufactured antimicrobial mat to be imposed to mats that it can prevent generation of bacteria and microorganisms, and restrict their reproduction. Infection of medical devices causes significant morbidity and mortality. For aim of this study, we measured the antimicrobial mat manufactured with N-(fluorodichlomethylthio) phthalimide-Ag complex by CCD, FT-IR and NMR. The effect of mole ratio of N-(fluorodichlomethylthio) phthalimide-Ag complex on antibacterial activity to bacteria and fungi is investigated. Reduction rate is evaluated using the Quinn method. Escherichia Coli is effectively inhibited than Staphylococcus aureus by antimicrobial mat.
        4,000원
        1549.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the antioxidative effects and inhibitory effects on tyrosinase and elastase of Sorbus commixta (S. commixta) twig extracts were investigated. The aglycone fraction of S. commixta twig extract showed the prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity(FSC50, 13μg/mL). Reactive oxygen species (ROS) scavenging activities of S. commixta twig extracts on ROS generated in Fe3+-EDTA/H2O2 system were investigated by the luminol-dependent chemiluminescence assay. The 50 % ethanol extract among extracts showed the most prominent ROS scavenging activity (OSC50, 0.189μg/mL). The cellular protective effects of extract/fractions of S. commixta twig on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The 50 % ethanol extract and ethyl acetate fraction showed the cellular protective effects against ROS in a concentration dependent manner (5~50μg/mL). The inhibitory effect of S. commixta twig extract on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate (IC50, 113.2μg/mL) and aglycone fraction(IC50, 105.3μg/mL) on tyrosinase showed more remarkable inhibitory effect than arbutin(IC50, 226.88μg/mL), known as the whitening agent. The inhibitory effect of aglycone fraction (IC50, 6.9μg/mL) on elastase was simillar to quercetin(IC50, 6.1μg/mL), flavonoid known as reference compound. These results indicate that extract/fractions of S. commixta twig can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging 1O2 and other ROS, and protect cellular membranes against ROS. S. commixta twig extracts can be applicable to new functional cosmetics for anti-aging products.
        4,000원
        1550.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is known that the content of saturated fatty acids methyl ester (SFAME) affect the pour point of biodiesel at low temperature. In this study, biodiesel (BD) was produced from beef tallow (TAL) by alkali catalyst. To reduce the saturation in BD, acetone fractionation was applied. Besides, TAL was also solvent-fractionated to reduce the saturated fatty acid (SFA) content for further producing BD. With acetone, TAL or TAL methyl ester (5:1 v/w) were fractionated at 10, 0, -10, and -15℃, respectively. At -10℃, 17.35% of SFA was observed in fractionated TAL (liquid part, -10TAL) when 5:1 solvent ratio was used for 24 hr. Under the same condition, fractionated BD (liquid part, -10BD) showed SFA (33.14%) with 78wt % yield. Also, fractionation of BD with different concentration of crystallizer 209 (0.1, 0.5, and 1%) along with different time (2, 6, 12, and 24 hr.) was observed. The best condition for reducing the SFA was 0.5% of crystallizer 209 addition for 12 hr of fractionation time at -10℃, in which 30.14% of SFA content was observed in BD (liquid part). Among different crystallizer, ps 66 showed the least content of SFA content (23.28%) in BD after fractionation (-10℃ and 24 hr) with 0.5wt% addition.
        4,000원
        1551.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sesame oil is a simple pressed oil as unrefined oil. During manufacturing process of roasting-expression, benzo(a)pyrene[B(a)P] formed as a strong carcinogenic substance is cause a social problem. In manufacturing process of sesame oil, it had following the forming pathway of benzo(a)pyrene[B(a)P] as well as minimizing plan of B(a)P formation. Suitable roasting condition by roaster was during 15~20min at 220℃, B(a)P content in sesame oil was 1.35~1.57μg/kg. Between roasting temperature and/or roastingtime and forming amount of B(a)P was showed a linear correlation. As a point of view the turbidity and yield of final product, roasting process of the more regular level was required.
        4,000원
        1552.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The average sulfur content of crude oil is 2.2%. Coal is about 0.3 to 4.0 percent of the sulfur gases or particles being discharged into the atmosphere through the chimney as 1 to 2% SO3(Sulfur trioxide) and about 95% of the SO2 is reported. SO3 gas, which has many different causes of, as the combustion of sulfur containing fuel during the air due to the excess SO2 gas is oxidized to SO3 gas. Sulfur trioxide emitted from high sulfur heavy oil fired boiler caused white plume in stack and high temperature and cold end corrosion of facilities. So, in order to control sulfur trioxide concentration of Fuel gas in boiler, various of additives are used in other foreign. They are injected to Fuel Oil and consumed in boiler and reduce ash and the conversion rate of sulfur trioxide. In domestic, MgO compounds are used as additives but the total volume of them are made from other foreign company. In this study, MgO compounds were developed with liquid MgO compounds and field application was accomplished. The effect of newly developed chemicals and process were nearly equal to foreign products. In Consequent, the chemicals and process produced by newly developed technology can be substituted for foreign products and reduce the cost of plant operation.
        4,000원
        1553.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This surfactant can be used as a cosmetics and chemical dispersants. The variation of critical micelle concentration(CMC) with temperature for N-eicosyl pyridinium bromide over the range 40℃ to 60℃ has been measured by drop methods. Thermodynamic quantities for micellization of N-eicosyl pyridinium bromide in water have been calculated by polynominal equation.
        4,000원
        1554.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chitosan is widely used in cosmetics and medical fields. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. We have described the synthesis and biological activity of novel peptide amino acid derivatives. The polyamino acid derivatives were synthesized by introducing alkylamine functional group on chitosan at C-6. The poor aqueous solubility of chitosan derivatives hinder both pharmacological studies and pharmaceutical development. To make amino acid coupled chitosan derivatives with improved biological effect and solubility, some attempts have been taken to consist of amino peptide group like aspartic acid and phenylalanine-aspartic acid derivatives onto chitosan C-6. The resultingly substituted chitosan was characterized by solubility in various solvents. We measured chitosan derivatives with 1H-NMR and 13C-NMR. Also, We were investigated on the physical properties and biological activities of these products.
        4,200원
        1555.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transparent liquid crystal gels with high oil content by fatty acid soap were investigated. The solubilization efficiency of the mineral oil was dependent on the process. The process of dropping water part into the solution of oil and surfactant was more efficient than the process of dropping water part into the surfactant solution and after that dropping oil. The fatty acid soap could not solubilize the high oil content, but under the certain range, addition of CDE (Coconut Diethanolamide), Arlacel 165 (Glyceryl Stearate/PEG-100 Stearate) and cetostearyl alcohol helped solubilize the high content oil. Also, the glycerin and water content had influence on the solubilization. Especially, higher oil content gel showed elastic feature.
        4,000원
        1556.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to provide an improving direction of K-EIP(Korean Eco-Industrial Park) construction project by company's voluntary participation. For this purpose, we investigated and analyzed the status of domestic eco-industrial park projects from various literatures, foreign EIP cases and FGI(Focus Group Interview). The key issues to construct a voluntary K-EIP are the lack of experts, the difficulties of commercialization financing, and so on. In this study, therefore, the programs to resolve these problems in K-EIP construction project were suggested at the level of government and corporation.
        4,500원
        1557.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Effects of ethylene-propylene diene monomer (EPDM)/polypropylene (PP), zinc oxide, stearic acid, and clay on the combustive properties based on EDPM/PP were investigated. The EDPM/PP/clay nanocomposites was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). It was found that the specific mass loss rate (SMLR) in the nanocomposites decreased due to the fire resistance compared with unfilled EDPM/PP, while the nanocomposites showed the higher total heat release (THR), higher CO production release, and higher specific extinction area (SEA) than those of virgin EPDM/PP. The stearic acid for softening ruber increased the THR and amount of smoke by itself, combustible.
        4,000원
        1558.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Compatibility and properties of PP/N66 blends with or without PP-g-MAH as a compatibilizer were investigated by DSC, SEM and universal testing machine. Morphological studies revealed that PP and N66 were incompatible and addition of PP-g-MAH was very effective to enhance the compatibility between PP and N66. The compatibilization effect between N66 and PP-g-MAH was based on the reaction between the amine end group of N66 and anhydride group in PP-g-MAH. The crystallization and melting behavior of PP/N66 blends were investigated and the results of analyses for enthalpy changed were discussed. The Izod impact strength could be improved by optimizing the compatibilizer concentration. Tensile strength, elongation at break, notched Izod impact strength were increased with using compatibilizer, however, both the compatibilized and the noncompatibilizer blends did not show any big difference in the flexural modulus.
        4,000원
        1559.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Natural Curcumin belongs to Zingiber Officinale Roscoe was known to possess natural odor, natural taste, natural color, and other pharmaceutical & chemical characteristics. Natural Curcumin extract was made to use ethanol as a solvent was to show a yellow color having state of solid powder and an active component. Natural Curcumin extract tested pharmaceutical & chemical experiment to dilute in curcumin 1%-water solution. Curcumin extract tested antimicrobial experiment using microbe, and tested dye experiment using fiber. Some conclusions in the result of characteristics experiment was obtained as follow. The result of antimicrobial experiment showed that the growth of staphylococcus aureus (ATCC-001) and aspergillus niger (ATCC-002) as microbes decreased according to passage of time. This phenomenon could know that Curcumin compoment showed influence to antimicrobial effect. Also, the result of dye experiment showed that cotton and sick with fiber dyeing dyed in direction of dark yellow color. This phenomenon could know that Curcumin extract showed influence to dyeing effect in observation of optical electron microscope(OEM.) The result of instrument analysis ascertained inorganic components of K(53.300ppm), Na(1.150ppm), Ca(0.711ppm), Ti(0.351ppm), Li(0.256ppm), Cu(0.233ppm) etcs from Curcumin component with ICP/OES, and ascertained organic components of propanoic acid(1.859), benzene(10.814), phenol(14.194) etcs from Curcumin component with GC/MSD.
        4,000원
        1560.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We are crystallized to the linear low density polyethylene(LLDPE) particles by a thermally induced phase separation(TIPS). TIPS process based on the phase separation mechanism was performed for the LLDPE system which undergoes liquid-solid phase separation. The linear low density polyethylene particle formation occurred by the nucleation and growth mechanism in the metastable region. Although the growth rates depended on the experimental conditions such as the polymer concentration and temperature, the particles were larger when the polymer concentration was higher or temperature was higher. The particles were observed by SEM. The LLDPE particle size distribution became broader when the polymer concentration was higher.
        4,000원