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        검색결과 2,503

        1601.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, much interest on mesoporous carbon has been shown in their use for both hydrogen and methane storage and as an electrode material for electric double layer capacitors. The mesoporous active carbons by ion exchange were prepared and physical properties such as specific surface area and pore structure of active carbon were investigated using BET. In this study, active carbons with mesopore fraction of 60~90% were obtained. The Fe/Ca-exchanged active carbons showed a greater mesoporosity compared with Fe-exchanged carbons. The mean mesopore size in active carbons using Ca- and Fe-exchange was about 5.5~6.0nm and was approximately 1nm higher than that of the Fe-exchanged active carbon.
        4,000원
        1602.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study DMT(Dimethylterephthalate), NDC(Dimethyl-2, 6-Naphthalene Dicarboxylate) were used to synthesize polyester polyol which shows enhanced storage stability, improved flame retardancy, and good compressive strength. If DMT and NDC react respectively with DEG(Diethylene Glycol) which is kind of linear diol, the obtained polyester polyols tend to crystallize easily after the reaction. In case of DMT, PA(Phthalic Anhydride) which has asymmetric structure was introduced to retard the crystallization. In case of NDC, DPG(Dipropylene Glycol) which has an methyl side chain was introduced to prevent the crystallization. It was found that to introduce DPG was much more effective method to prevent the crystallization than PA. NDC and DMT were reacted together with DPG for various compositions of NDC:DMT(8:2, 6:4, 4:6 mol ratio). The obtained NDC-DMT-DPG based polyester polyol showed improved flame retardancy, and good compressive strength with increasing the content of NDC.
        4,200원
        1603.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, block copolymer of polystyrene and polyethylene glycol methyl ether methacrylate(PEGMA) by ATRP(atom transfer radical polymerization) method was synthesized. 4 arm-molecule which contained halogen atom was synthesized for an initiator. With 4 arm-molecule monodispered polystyrene were synthesized by ATRP method. The molecular change of synthesized monodispersed polystyrene with respect to time was investigated and living polymer characteristic was confirmed. Block copolymer of polystyrene and polyethylene glycol methyl ether methacrylate(PEGMA) was synthesized by ATRP with macroinitiator which was synthesized from the monodispersed polystyrene(Mn=12000). The molecular weight of obtained PS-b-PEGMA was 22,000.
        4,200원
        1604.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Melanoma is the most serious type of skin cancer as a malignant tumor of melanocytes. In this work, the syntheses of a novel series of benzaminoquinoline derivatives 1a-c and their antiproliferative activities against A375 human melanoma cell line were described. All the compounds (IC50=0.78-1.02μM) showed superior antiproliferative activities to Sorafenib (IC50=5.58μM) as a reference compound. These results suggested that benzaminoquinoline derivatives have potentials as a therapeutic agent for the treatment for melanoma.
        4,000원
        1605.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the silica-based hybrid material with high barrier property was prepared by incorporating ethylene-vinyl alcohol (EVOH) copolymer, which has been utilized as packaging materials due to its superior gas permeation resistance, during sol-gel process. In preparation of this EVOH/SiO2 hybrid coating materials, the (3-glycidoxy-propyl)-trimethoxysilane (GPTMS) as a silane coupling agent was employed to promote interfacial adhesion between organic and inorganic phases. As confirmed from FT-IR analysis, the physical interaction between two phases was improved due to the increased hydrogen bonding, resulting in homogeneous microstructure with dispersion of nano-sized silica particles. However, depending on the range of content of added silane coupling agent (GPTMS), micro-phase separated microstructure in the hybrid could be observed due to insufficient interfacial attraction or possibility of polymerization reaction of epoxide ring in GPTMS. The oxygen barrier property of the mono-layer coated BOPP (biaxially oriented polypropylene) film was examined for the hybrids containing various GPTMS contents. Consequently, it is revealed that GPTMS should be used in an optimum level of content to produce the high barrier EVOH/SiO2 hybrid material with an improved optical transparency and homogeneous phase morphology.
        4,000원
        1606.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of C5+ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.
        4,000원
        1607.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the anti oxidative effects, inhibitory effects on elastase, and components of Securinega suffruticosa extracts were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities (FSC50) and reactive oxygen species ROS) scavenging activities (OSC50) of extract/fractions from Securinega suffruticosa were measured. The aglycone fraction (9.04 ± 0.51 μg/mL) and 50 % ethanol extract (1.05 ± 0.41 μg/mL) showed the most effective scavenging activities. The protective effects on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The aglycone fraction exhibited the most prominent cellular protective effect (τ50, 102.77 ± 5.37 min at 10μg/mL). The inhibitory effect of ethyl acetate fraction on tyrosinase were of examined (210.0 ± 1.02 μg/mL). The inhibitory effect of aglycone fraction on elastase were also investigated (17.6 ± 1.26 μg/mL). These results indicate that extract/fractions of Securinega suffruticosa 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. Securinega suffruticosa extract could be used as a new cosmeceutical ingredient for whitening and anti-wrinkle products.
        4,000원
        1608.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Superporous Hydrogels (SPHs) have been extensively investigated for various biomedical applications due to their fast swelling and superabsorbent properties. In this study, glycol chitosan that is one of most abundant natural polymers was used as a cross-linking agent instead of bisacrylamide (BIS), which is a broadly used crosslinking agent for preparation of SPHs. Glycol chitosan was modified to have reactive vinyl groups by chemical conjugation with glycidyl methacrylate (GMA). The vinyl group-containing glycol chitosan (GC-GMA) was characterized by FT-IR and 1H-NMR measurements. SPHs have been prepared in various synthetic conditions to establish the optimum synthetic process for making superporous structure, where the inner pores are interconnected to each other to form a open channel structure. Various SPHs with different GC-GMA contents have been successfully prepared and have been observed to show faster swelling properties than other conventional SPHs. From the study on the swelling behavior of SPHs, the GC-GMA content is considered to be an important factor for controlling their swelling properties.
        4,000원
        1609.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is on the feasibility of use of glycoprotein in various areas such as cosmetics and food etc. by extracting, isolating and refining glycoprotein from carrots, red ginseng extract residue, sesame and pine needles using protease(pepsin) and by analyzing general characteristics and measuring various bioactivities. The results of analysis of nutritional composition showed protein contents of glycoprotein. In the analysis of constitutive amino acids, the ratio of contents of hydroxy proline and glycine, the characteristics of glycoproteins appeared similar and the contents of glutamic acid and aspartic acid appeared higher. As a result of measurement contents of total polyphenol and flavonoid, it showed that glycoprotein had more contents generally, and the effect of bioactivity of glycoprotein appeared higher although different kinds of glycoprotein showed a little DPPH radical and nitrite scavenging ability, total antioxidant capacity by ABTS, ACE inhibitory.
        4,800원
        1610.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to develop a method to evaluate solubility parameter interactions of cosmetic ingredients in formulations. This experimentation relates to the fabrication of new multi-layer cleansing oil which can remove make-up products such as lipstick, foundation, mascara, eye shadow, etc., and also can wash away dirt and sebum from the skin just in one stage process. Solubility parameter and specific gravity of various cosmetic ingredients are measured to explain the cleanliness of interface, detergency of make-up cosmetics on the skin surface. The results suggest that it is possible for cosmetic chemists to use solubility parameter of cosmetic materials for fabrication of new formulation of 3-layer cleansing oil.
        4,000원
        1611.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A reaction device raising a generation yield by efficiently removing water generated in an esterified reaction between diethylene glycol monoethyl ether and succinic acid with mixture of an azeotropic point was newly developed as a new product in development of more stabilized emulsifier with a semi-solid phase(cream) in an emulsified phase of interfacial activity. The bis-(diethylene glycol monoethyl ether succinate(hereinafter, called as BDGS) with a high yield of more than 95% was obtained. As this has a property containing amphoteric emulsified functions such as W/O type or O/W type, etc., and has a merit that can be used regardless of any emulsified phase, there is no need using other emulsified surfactant. therefore, as this has excellent skin wetability in the cosmetics industry, a product having a wider range in quality compatibility or cost saving, etc. as a humectant has been developed.
        4,000원
        1612.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Techniques measuring Maxwell displacement current (MDC) and LB films surface measuring technique have been applied to the study of monolayers of polyamic acid containing azobenzene. MDCs was generated from monolayers on the water surface by monolayer compression and expansion. It was generated when the area per molecule was about 103a2 and 78a2 just before the initial rise of the surface pressure during the 1st and 2nd mixed monolayer compressions cycle, respectively. It was the maximum of MDCs appeared at the molecular area just before the initial rise of surface pressure in compression cycles, and we have found that the increase of aggregations causes the noticeable increase of the surface roughness.
        4,000원
        1613.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Conventional additives were added to a newly synthesized base oil to create synthetic lubricants. Commercial polyol ester prepared in this laboratory were obtained as esterification of 1,1,1-trimethylol propane and respectively. This newly synthesized base oil had a variable chemical structure that could achieved the following properties; oxidation or thermal stability, low temperature fluidity, and higher flash points. When compared with commercial mineral lubricants, the synthetic lubricants show superior thermal and oxidation stability, and anti-wear properties.
        4,200원
        1614.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Solution copolymerization of Styrene(St.) with 2-Hydroxypropylacrylate(2-HPA) was carried out with Benzoylperoxide(BPO) as an initiator in toluene at 80℃ in a batch reactor. Reaction volume and reaction time were 0.3 liters, 8 hours respectively. The time to reach steady state was about the six time. The monomer reactivity ratios, r1(St.) and r2(2-HPA) were determined by both the Kelen-Tudos method and the Fineman-Ross method ; r1(St.)=0.376(0.330), r2(2-HPA)=0.408(0.778). The activation energy of thermal decomposition was in the range of 33~55kcal/mol.
        4,000원
        1615.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S133D) surfactant was prepared. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 2.0 wt% EU-S133D, silicone dioxide/Acrylate core-shell polymerization was carried out on the surface of silicone dioxide particle without forming the new silicone dioxide particle during acrylate shell polymerization in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).
        4,000원
        1616.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have tested the stability of paeoniflorin, a new cosmetic ingredient, extracted from the roots of Paeoniae lactiflora. The stability of aqueous paeoniflorin solution at pH 3, 5 and 7 varied by adding buffer solution was tested at 0℃, 25℃, 40℃, and 65℃. The test was performed with or without UV light. The solution of paeoniflorin was stable at pH 3.0, however, the recovery rate of paeoniflorin was 40% at pH 7.0. The stability of paeoniflorin solution was decreased as the pH of paeoniflorin solution was increased by pH 7.0. The effect of storage temperature of paeoniflorin solution shows that the stability of paeoniflorin solution was decreased as the temperature was increased. The stability of paeoniflorin was rather good under UV light than the condition given above 40℃. The stability of paeoniflorin in W/O emulsions shows similar pattern to that of aqueous solution.
        4,000원
        1617.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the previous study, we reported the antioxidative activity and inhibition of melanogenesis of Ligularia stenocephala extracts. In this study, inhibitory effect on elastase and production type I procollagen were investigated. The compounds which was investigated were 4-hydroxyacetophenone, vanillin, chlorogenic acid, caffeic acid isolated from Ligularia stenocephala. They were slightly mild on elastase inhibition activity but 4-hydroxyacetophenone, vanillin exhibited good inhibition activity on collagen production. These results suggest that Ligularia stenocephala may have potential as an anti-aging ingredient in cosmetics.
        4,000원
        1618.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The esterification of the reactants of Jatropha oil and methanol added by propyleneglycol was done using p-TSA catalyst. And then the emulsification of triglyceride and methanol was conduced by 1.0vol% GMS. The emulsified reactants were transesterified at 65℃ using TMAH and mixed catalyst (50wt%-TMAH+50wt%-NaOH) respectively. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 80min. The overall conversion at the 1:8 molar ratio of mixed fat(50wt% Beef Tallow) to methanol and 65℃ using mixed catalyst was 95.4% The cloud point of Biodiesel decreased with the addition of petroleum diesel.
        4,000원
        1619.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A comparative analysis of the hindered amine light stabilizers (HALS) and UV abosrber (UVA) and their respective photostabilizing effect on wood plastic composites (WPCs) are reported in this study. The influence of accelerated weathering on the mechanical properties of the composites and the microscopic morphology of a degraded layer on the cross section and the surface were studied. UV absorbers were more efficient at preventing composite lightening than was UV stabilizer. The amount of whitening decreased with the increase of photostabilizers. With the addition of a UV absorber (Tinuvin360), the tensile modulus and strength of the composites increased slightly. However, the addition of a light stabilizer (Tinuvin770) and a UV absorber decreased the tensile modulus and strength of the composites. After 250 and 500 hr exposure, tensile modulus and strength of the un stabilized and stabilized composites decreased. The tensile strength of UV absorber (Chimassorb81)-stabilized composites was significantly greater than that of control and light stabilizer (Tinuvin770)- and UV absorber (Tinuvin360)-stabilized composites. UV absorber-stabilized samples showed less whitening and photodegradation than control and light stabilizer-stabilized samples.
        4,000원
        1620.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this work, a novel series of aminoisoquinolinylamide derivatives 1a-c and 2a-f were synthesized via several reaction steps, starting from 2-methyl-4-nitrobenzonitrile (3) and 1-chloro-5-nitroquinoline (8). And their antiproliferative activities were screened against A375 human melanoma cell line compared to Sorafenib as a reference compound. Among them, compound 1b and 1c exhibited meaningful inhibitory activities. These results demonstrated that aminoisoquinolinylamide scaffold possesses the possibility as the treatment for melanoma.
        4,000원