간행물

한국응용과학기술학회지 KCI 등재 The Korean Society of Applied Science and Technology

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Vol.28 No.1 (2011년 3월) 16

1.
2011.03 구독 인증기관 무료, 개인회원 유료
In this study, We investigated the properites of nano-emulsions containing hydrogenated lecithin prepared by high pressure homogenizer. The size of droplet of emulsions prepared by homogenizer at various rpm (rotation per minute) was not measured due to the unstability of emulsions, however, the size of droplet of nano-emulsions prepared by high pressure homogenizer was around 300 nm and the appearance of emulsions was bluish. The stability of emulsions with various lecithin concentration was tested against time. POV (Peroxide value) of emulsions were plotted against time. POVs of emulsions prepared with an egg lecithin and a soy lecithin were increased with time, however, POV of emulsion with Lecinol S-10® was kept constant within 60 hours and at 60℃. In consumer test, the nano-emulsion showed higher affinity regardless of skin type. Both of irritation scores of emulsions were similar.
4,000원
2.
2011.03 구독 인증기관 무료, 개인회원 유료
Step feed process was analyzed stoichiometrically for the optimal operation conditions in this study. In case of optimal operation conditions, minimum R (sludge recycling) value, r (internal recycling ratio) value, and n (influent allocation ratio) value for the step feed process to acquire the maximum TN removal efficiency were identified by theoretical analysis. Maximum TN removal efficiency, based on stoichiometric reaction, can be obtained by controlling n value for the step feed process.
3,000원
3.
2011.03 구독 인증기관 무료, 개인회원 유료
Emulsion polymerization was carried out using RMA like MMA, EMA, BMA and Styrene(St.) as monomer for core-shell latex preparation. It was synthesized at 80℃ in the presence of anionic surfactant SLS. FT-IR, TGA and DSC analysis are used to confirm synthesized core-shell emulsion latexes and to investigate the thermal characteristics of them. From analysis of TGA and DSC, the differences of the decomposition rate and the activation energy are not so large. It considers that the pendent group is not affect of the thermal characteristics and stability on core-shell latexes, which is synthesized with RMA and Styrene.
4,000원
4.
2011.03 구독 인증기관 무료, 개인회원 유료
Threelectrodes systems were used in stripping voltammetry (SW) and cyclic voltammetry (CV) instead of the expensive platinum and Ag/AgCl reference electrodes. Moreover, the electrolyte solution was used with deep seawater, which can reduce water pollution, is more eco-friendly, and has a lower cost. The analytical optimum parameters measured via CV and SW and with working ranges were obtained from 10 to 80 ug/L using fluorine immobilized on a graphite pencil electrode (FE). Under the optimum conditions, the analytical detection limit of 6.30 ug/LAu was obtained. The results of the study can be applied to diagnostic assay for natural minerals and human finger tissue.
4,000원
5.
2011.03 구독 인증기관 무료, 개인회원 유료
Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD] was kinetically investigated in the presence of organometallic catalysts (ESCAT-100Ag18, MBTO) at 150~180℃. The reaction followed from the measurement of the quantity of water which was distilled from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculated as 146.70 kJ/mol(ESCAT-100Ag18) and 87.57 kJ/mol(MBTO), respectively.
4,000원
6.
2011.03 구독 인증기관 무료, 개인회원 유료
The sterilization of strain and algae in sea water was studied to see the possibility to apply the redox reaction of metal alloy to meet the international marine organization(IMO) regulation, which was to regulate deballasting concentration of strain and algae above 99% of sterilization. Two different kinds of brass were heat treated at different temperature and cooled rapidly to conserve the specific character of β brass. Untreated Muntz metal showed the best result of antimicrobial rate in sea water, and 7:3 brass showed similar result to Muntz metal. Heavy metal elution rate was inversely proportional to the sterilization capability.
4,000원
7.
2011.03 구독 인증기관 무료, 개인회원 유료
For the synthesis of water soluble acrylic modified epoxyester resin, fatty acid/epoxy ratio of 50/50 was used, and introduced maleic anhydride. Ratio of styrene/acrylic acid of acrylic monomers was fixed 85/15 and ratio of epoxyester/acrylic monomer was controlled 80/20, 75/25, 70/30, 65/35, and degree of neutralization were changed 65%, 80%, to 100%. As a result, 40% solids acrylic modified epoxyester resins were synthesized. Resins were evaluated water soluble stability, drying time, water resistant, storage stability and physical properties. And the white paints were prepared, and were evaluated viscosity, drying time, water resistance, adhesion, sagging, spray workability, gloss, salt spray resistance, skinning, whiteness and flash rust. As a result, the degree of neutralization of 100% and the ratio of epoxyester/acrylic monomer of 75/25 showed the best properties.
4,500원
8.
2011.03 구독 인증기관 무료, 개인회원 유료
In this study, we investigated the C-V diagrams and metal surface related to the electrochemistry characterization of metal(nickel, SUS-304). We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150, 200 and 250 mV/s. As a result, the C-V characterization of metal using N,N-dimethylacetamide and N,N-dimethylformamide inhibitors appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding organic corrosion inhibitors, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the addition of inhibitors containing amide functional group enhances the corrosion resistance properties.
4,000원
9.
2011.03 구독 인증기관 무료, 개인회원 유료
Polymer electrolyte membrane fuel cell (PEMFC) performance degrades when hydrogen sulfide (H2S) is present in the fuel hydrogen gas; this is referred to as H2S poisoning. This paper reveals H2S poisoning on PEMFC by measuring electrical performance of single cell FC under various operating conditions. The severity of H2S poisoning depended on H2S concentration under best operating conditions(65℃ of cell temperature and 100% of anode humidification). H2S adsorption occured on the surface of catalyst layer on MEA, but not on the gas diffusion layer(GDL) by analyzing SEM/EDX data. In addition, MEA poisoning by H2S was cumulative but reversible. After poisoning for less than 150 min, performance of PEMFC was recovered up to 80% by just inert nitrogen gas purging.
4,000원
10.
2011.03 구독 인증기관 무료, 개인회원 유료
The aim of study was to investigate polluted amounts 16 PAHs in railroad(waste railway ties) area, factory area and land-fill area. All of the samples were analyzed by GC-MSD(SIM mode), and the recovery range, detection limit and standard deviation obtained by this experiment were 73.88 ~ 94.75%, 0.009 ~ 2.252 μg/kg and 1.861 ~ 12.373, respectively. The concentrations of total PAHs(t-PAHs) and total carcinogenic PAHs(t-PAHcarc) in soils of three area were in the range of 12.54 ~ 3274.95 μg/kg on a wet weight basis with a mean value of 499.8 μg/kg and 0 ~122.77 μg/kg with a mean value of 20.16 μg/kg, respectively. The correlation between t-PAHs and t-PAHcarc appeared very high in railroad(waste railway ties) area (R2 = 0.8301), factory area (R2 = 0.9217) except land-fill area(R2 = 0.3782), indicated that t-PAHcarc concentration increases in proportion with t-PAHs.
4,200원
11.
2011.03 구독 인증기관 무료, 개인회원 유료
Atopic dermatitis is a chronic inflammatory skin disease associated with cutaneous hyper-reactivity to environmental triggers. In order to develop effective therapeutic herbal extracts for atopic dermatitis, cytotoxicity, antioxidant, anti-inflammatory and anti-allergic activities were investigated for various herbal extracts. Among candidate extracts, we selected Aloe vera L. (AV), Viola mandshurica W. Becker (VM), Punica granatum L. (PG), Dendrobium nobile L. (DN) and mixture of the above extracts (MX) for further investigations. All of them did not show cytotoxic activities to macrophage RAW264.7 cells below the concentration of 100 ppm. All showed antioxidant, anti-inflammatory and anti-allergic effects, although to various extents. In antioxidant effects, AV showed the highest effect, followed by PG and VM, while DN did the lowest. In evaluation for anti-inflammatory activities in macrophage RAW264.7 cells, AV and DN inhibited almost completely the LPS-induced production of nitric oxide, while AV, DN and VM showed strong inhibitory activities on the LPS-induced production of TNF-α. In anti-allergy effect in mast cell HMC-1, DN showed the highest effect, followed by AV and PG, while VM did the lowest. In the topical allergy reaction induced by compound 48/80 in Sprague-Dawley rat, DN exhibited significant anti-allergic effect, while PG, VM and AV did slight effect. These results suggest that AV, VM, PG and DN have antioxidant, anti-inflammatory and anti-allergic activities, and thus have the potential to reduce and alleviate the symptoms of atopic dermatitis.
4,000원
12.
2011.03 구독 인증기관 무료, 개인회원 유료
Expanded graphites were used as anode materials of high power Li-ion secondary battery. The expanded graphite was prepared by mixing the graphite with HClO4 as a intercalation agents and KMnO4 as a oxidizing agents. The physical and electrochemical properties of prepared expanded graphites through the variation of process variables such as contents of intercalation agent and oxidizing agent, and heat treatment temperature were analyzed for determination of optimal conditions as the anode of high power Li-ion secondary battery. After examing the electrochemical properties of expanded graphites at the different preparing conditions, the optimal conditions of expanded graphite were selected as 8 wt.% of oxidizing agent, 400 g of intercalation agent for 20 g of natural graphite, and heat treatment at 1000℃. The sample showed the improved charge/discharge characteristics such as 432 mAh/g of initial reversible capacity, 88% of discharge rate capability at 10 C-rate, and 24 mAh/g of charge capacity at 10 C-rate. However, the expanded graphite had the problems of potential plateaus like natural graphite and lower initial efficiency than the natural graphite.
4,000원
13.
2011.03 구독 인증기관 무료, 개인회원 유료
We estimated on the stability of W/O type emulsified fuel using by capacitance sensor, so it concluded the following conclusions. For the first 24 hours, prepared emulsified fuel reveals phase separation ratio of 5%, maintains stable status which verifies the stability of emulsified fuel. Adding more water increases the phase separation ratio rapidly, and adding more surfactant displays stable emulsification. Adding water causes larger size of water droplet diameter, and adding surfactant mixture causes smaller size of water droplet diameter. In conclusion, the size of W/O type emulsified fuel water droplet diameter is directly related to the volume of surfactant, and density of water droplet diameter changes thedistribution according to water contents.
4,000원
14.
2011.03 구독 인증기관 무료, 개인회원 유료
The study of wave propagation and scattering in biological media has become increasingly important in recent years. The propagation of light within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is measured. To obtain the results of scattering coefficients(μs) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of (I/Io)wavelength vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements. The result was compromised with transport of intensities though a random distribution of scatters.
4,000원
15.
2011.03 구독 인증기관 무료, 개인회원 유료
In this study, we experimented that how influence chain extension to waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and machanical properties. By instruments analysis measurement we confirmed that synthesis of epoxy and hybrid resin. In this experiment we knew that polyurethane-epoxy hybrid resin have 5 grades of solvent resistance. Tensile strength measured in the polyurethane-epoxy resin(EDA 5.37g, 2.386 kgf/mm2) had the most strong strength.. Also polyurethane-epoxy hybrid resin had better result(EDA 5.37g. 37.4 mg. loss) than other hybrid resins. As hight proportion of EDA in hybid resin, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of EDA.
4,000원
16.
2011.03 구독 인증기관 무료, 개인회원 유료
New type of 5-fluorobenzimidazole derivatives was synthesized through the reaction of 4-fluoro-5-(2,6-dimethylmorpholinyl)-2-aminoaniline with 5-nitro-2-furoic acid and 5-methoxy-3-chlorobenzothiophene-2-carboxylic acid in presence of PPA and treatment of OH-. the resulting substituted 5-fluorobenzimidazole derivatives(6), (7) was characterized by high solubility in common polar organic solvents. We considered 5-fluorobenzimidazole derivatives were useful especially for antifungal drugs. These results are discussed from the viewpoints of the chemical and physical structures of the 5-fluorobenzimidazole derivatives.
4,000원