In this article a reliable and rapid method based on specific turbidimetry is proposed for the determination of sizes of nanoparticles. Conventionally in specific turbidimetry specific turbidities for a colloidal dispersion are measured as a function of light wavelength, and compared to theoretical values calculated from Mie scattering theory for presumed particle sizes. In contrast specific turbidity at a fixed wavelength is measured in the proposed method, and particle sizes are determined from the prepared calibration curve. The calibration curve is a plot of specific turbidity vs particle size and in this case the specific turbidities are measured for a couple of samples of known sizes.

Development of white light emitting materials has been an interesting area for scientists and scientists have developed many organic, polymer and inorganic materials for white electroluminescent devices. Among them, single component small molecules gave best results in terms of efficiency, simplicity of device fabrication, and CIE values. Therefore, this review covers detailed discussion about syntheses of small compounds used in white organic light emitting devices until 2007.

The core-shell latex particles were prepared by sequential emulsion polymerization using alkyl methacrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We study the effects of core-shell structure of calcium carbonate/alkyl methacrlyate in the presence of an anionic surfactant sodium lauryl sulfate (SLS) and polyoxyethylene alkyl ether sulfate (EU-S133D)). 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 transmission electron microscope (TEM).

This study was done to investigate the antidiabetic and antioxidant effects of Lycii fructus in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose 45mg/kg.b.w. dissolved in citrate buffer(pH4.5). The ethanol extract of Lycii fructus was orally administrated once a day for 7 days. The contents of serum glucose, total cholesterol were significantly decreaed (p<0.05) in Lycii fructus treated group compared to the those of STZ-control group, also content of Triglyceride (TG), Altherogenic index (AI) were decreased, but not statistically significant. But high density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were increased in Lycii fructus treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase(G-6PDH), glutathione-s-transferase(GST), superoxide dismutase(SOD) were significantly increased(p<0.05), glucose-6-phos-phatase(G-6pase)was significantly decreased(p<0.05) and The glutathione(GSH), glucokinase(GK) were increased. But not statistically significant In Lycii fructus treated group compared to the those of STZ-control group These results indicated that ethanol extract of Lycii fructus would have antidiabetic and antioxidant effects in STZ-induced diabetic rats.

The ion exchangers supported on silica gel containing primary, secondary, or tertiary amine groups show a behaviour that is weakly acidic, while the quaternary salts are strongly acidic. These properties change according to the hydrophilicities of the modifier functional groups. Ammonium salt derivatives supported on silica gel were prepared from silica modified with 3-Aminopropyltriethoxysiliane and N-3-(Trimethoxysilyl)propylehtylene diamine. The preparation and the ion exchange properties of two systems were discussed. Two systems have different hydrophilicities and contain ammonium chloride derivatives of 3-amminopropyltriethoxysilane and N-3-(triehtoxysilyl)propyl ethylene diamine supported on silica gel, SA+/Cl- and SA+/Cl-, respectively. The high affinity to perchlorate ion presented by the SA+/Cl- through the equilibrium studies of ion exchange led us to its application as an ion selective electrode for the perchlorate ion. The determination of the perchlorate ion in the presence of other anions and in complexes is very difficult. Few analytical methods are available and most of them are indirect. Both materials showed potential use as an ion exchanger; they are thermically stable, achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered.

Pretreatment of eliminating FFA is needed to make biodiesel from animal fat recovered from leather wastes because its acid value is high. This study was carried out to investigate the influence of 4 different pretreatment methods, which are heterogeneous catalyst method, ion exchange resin method, low pressure.high temperature method, and alkali method on the eliminating FFA and fatty acid composition. The results showed that the rate of eliminating FFA increased in the order of alkali method > catalyst method > low pressure high temperature method > ion exchange method. In the case of pretreatment of alkali method using NaOH, the rate of eliminating FFA appeared more than 86% regardless of acid value. Therefore, it was considered that alkali method using NaOH was the most effective in the view of economical and productive aspects, taking it into account that the acid value of animal fat recovered from fleshing scrap generated during leather making processes was 7 to 8.

In the present study, impedance characteristics for AgO-Zn cell at various State-of-Charge (SoC) has been studied. The impedance measurements of AgO-Zn cell at various SoC were made over the frequency range from 100kHz to 10mHz with an amplitude 5mV. The impedance parameters have been evaluated by the analysis of the data using an equivalent circuit and a Non-linear least squares (NLLS) fitting method. The total resistances reflects the SoC of the cell. This indicates that the total resistance is important parameter for predicting SoC of AgO-Zn cell.

Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at 30-50℃ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at 37-44℃.

This study was conducted to made a grid alloy (Pb-Ca-Sn-Al) which has a temporary composition ratio in order to improve the efficiency of lead acid batteries. The positive activity material made a 3BS(tri-basic lead sulfate; 3PbO·PbSO4·H2O) by a low temperature curing and it evaluates the plate efficiency through the life cycle testing. The initial current capacity of low temperature curing plate was excellent but the life cycle was not good (S1). As for the S2 plate, however, the initial current capacity and the life cycle were superior.

1,4-Dioxane is an EPA priority pollutant often found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to decompose this compound effectively. Therefore, an advanced oxidation process system (AOP) was used for the degradation of 1,4-dioxane. This research investigates the effect of adding oxidants, such as ozone, air, and H2O2 during the UV irradiation of 1,4-dioxane solution. In order to analyze 1,4-dioxane, a modified 8270 method, which is an improved method of U.S EPA 8720, was used. Degradation efficiencies of 1,4-dioxane by only UV irradiation at various temperatures were not significant. However, The addition of oxidants and air bubbling in the UV irradiation system for 1,4-dioxane decomposition showed the higher 1,4-dioxane degradation rate. And, during AOP treatment the tendency of TOC changes was similar to that of 1,4-dioxane decomposition rate.

In general, anionic and cationic surfactants are incompatible because their mixtures form insoluble complexes. There are, however, some complexes that are soluble and behave like regular surfactants, specifically like nonionic surfactants, thus named pseudo-nonionic surfactant complexes. Pseudo-nonionic complexes are more effective and efficient than their ionic surfactant components as shown by their equilibrium and dynamic surface tensions and interfacial tensions. They pack at the interface more than their ionic components. Since, pseudo-nonionic complexes show their own characteristics, they can be treated as separate classes of surfactants distinct from ionic and nonionic surfactants. Novel cationic surfactant was synthesized, having the polyhydroxyl group at the head group. We found that aqueous mixtures of our cationic surfactant and usual anionic surfactant(SDS) could form homogeneous solutions even at high concentration. The properties of mixed surfactant solutions were measured. Foam stability, CMC(critical micelle concentration), water hardness tolerance and thickening effect were tested. The foam stability of mixed surfactants was very good and various synergy effects were observed.

The effects of fillers on the mechanical and thermal properties of glass/novolac composites have been studied. The matrix polymer and reinforcement were novolac type phenolic resin and milled glass fiber, respectively. Three different fillers, such as calcium carbonate, aluminum oxide, and wood powder were used for glass fiber reinforced plastic(GFRP) manufacture. Gravity, moisture content, tensile and flexural strength were measured to analyze the mechanical properties of GFRP and the final composites was burned in the electronic furnace at 1000℃ to confirm thermal properties GFRP containing aluminium oxide shows the highest thermal stability with 32% of weight loss at 1000℃ for one hour. GFRP containing calcium carbonate shows the maximum flexural strength (146 MPa), but that containing wood powder dose the highest tensile strength (65 MPa). Conclusively, we found that the characteristics of final composites strongly depend on several factors, such as types of materials, contents and chemical affinity of fillers. Therefore, it is very important to set up the combination of fillers for GFRP manufacturing to improve both mechanical and thermal properties at the same time.

To prepare weather-resistant modified silane acrylic resin coatings for an architectural purpose, tetrapolymers were synthesized by radical polymerization. 3-Methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer and n-butyl acrylate, methyl methacrylate, and n-butyl methacrylate as acrylic monomers were used. The composition of monomers was adjusted to fix the glass transition temperature of acrylic polymer for 20℃. The composition of MPTS in the synthesized polymer were varied from 10 wt% to 30 wt%. On the basis of synthesized resin amber paints were prepared and their physical properties and effects on weatherability were examined. The presence of MPTS in modified silane acrylic resins generally resulted in low molecular weight and broad molecular weight distribution, and also lowered the viscosity of the copolymers. The coated films prepared from these resins showed good and balanced properties in general. Adhesion to the substrate was outstanding in particular. Weatherability tests were carried out in three different types such as outdoor exposure, QUV, and SWO. The test results showed that the modified silane acrylic resins containing 30 wt% of MPTS had superior weathering properties.

Anaerobic reductive dehalogenation of perchloroethene (PCE) was studied with lactate as the electron donor in a continuously stirred tank reactor (CSTR) inoculated with a mixed culture previously shown to dehalogenate vinyl chloride (VC). cis-1,2- dichloroethene (cDCE) was the dominant intermediate at relatively long cell retention times (〉56 days) and the electron acceptor to electron donor molar ratio (PCE:lactate) of 1:2. cDCE was transformed to VC completely at the PCE to lactate molar ratio of 1:4, and the final products of PCE dehalogenation were VC (80%) and ethene (20%). VC dehalogenation was inhibited by cDCE dehalogenation. Propionate produced from the fermentation of lactate might be used as electron donor for the dehalogenation. Batch experiments were performed to evaluate the effects of increased hydrogen, VC, and trichloroethene (TCE) on VC dehalogenation which is the rate-limiting step in PCE dehalogenation The addition of TCE increased the VC dehalogenaiton rate more than an increase in the H2 concentration, which suggests that the introduction of TCE induces the production of an enzyme that can comtabolize VC.

에너지원으로서 수소를 생산하기 위하여 하니컴 구조를 갖는 모노리스에 10 wt% Ni/CeO2-ZrO2 촉매를 담지한 후 메탄의 수증기 개질 실험을 수행하였다. 다른 CeO2/ZrO2 몰비를 갖는 촉매들 중에서, Ni/CeO2-ZrO2(CeO2/ZrO2=4/1)촉매가 700-800℃에서 높은 메탄의 전환율을 보여 주었다. 10wt% Ni/CeO2-ZrO2 촉매가 담지된 금속 모노리스 촉매체는 높은 열전도도와 비표면적들로 인하여 좋은 촉매 특성을 보여줌을 확인할 수 있었다. 또한, 금속모노리스 촉매체는 반응물에서 과다의 수증기에 의한 수소 수율에서 크게 영향을 받지 않음을 알 수 있었다. GHSV=30,000h-1, 반응물 비(H2O/CH4=3.0) 반응온도 800℃에서 금속모노리스 촉매체는 98%이상의 메탄의 전환율을 보여주었다. 생성물 가스에서 CO2/CO의 비는 수증기/메탄의 반응물비가 증가할수록 수성가스화 반응에 의하여 증가됨을 알 수 있었다.

Polypropylene (PP) composites with wood flour/wax/coupling agent were manufactured by melt compounding and injection molding. The influence of wood flour(WF), wax, and coupling agent on the mechanical and thermal properties of the composites was investigated. The addition of wood flour to neat PP has the higher tensile modulus and strength compared with neat PP. The presence of wax also improved the tensile modulus. At the same loading of PP and WF, the addition of coupling agent highly decreased the tensile modulus, and increased the tensile strength. From thermogravimetric analysis (TGA), the addition of wax improved the thermal stability of the composites in the later stages of degradation. The presence of MAPP and wood flour in turn decreased thermal stabilities of composites. From differential scanning calorimetry analysis (DSC), neither the loading of wax. nor the presence of MAPP has shown significant effect on the thermal transition of composites.

Functional cosmetics are intensively investigated for the effectiveness of skin whitening, anti-aging and slimming. For enhancing the effectiveness, active ingredients should be delivered into the cell in the dermis. The amounts of penetration of caffeine and Arbutin® were tested, in vitro, using Franz diffusion cell. Oil-in-water emulsions were used for the vehicles of the transport. For the measuring the amounts of active ingredients delivered into the dermal skin, tape stripping was done after finishing the penetration experiments. The amounts of delivered caffeine were 8.45± 1.26ug/ml before tape stripping and 3.45± 1.80ug/ml after tape stripping, however, the amounts of delivered Arbutin® was quite small to detect. From now on, proper vehicles are considered for enhancing the delivery of Arbutin® Hairless mouse skin was compared with pig skin as a transdermal delivery membrane. The aspects of delivery were similar, but the amount of delivered ingredients using pig skin was larger than that of using hairless mouse skin. Therefore, the pig skin would be considered as a membrane for drug delivery experiments.

Characteristics of polyaniline anti-corrosive coatings with various primer coating resins(epoxy resin, urethane resin, and others) and top coating resins(epoxy and acrylic urethane resins) were investigated through adhesion, acid resistance, alkaline resistance, water resistance, and anti-corrosion tests. As a result, the anti-corrosive properties of the prepared coatings using polyaniline varied with the types of primer and top coating resins. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using emeraldine base (EB) of polyaniline blended with single-packaged urethane and acrylic urethane resins as the primer coatings, and using acrylic urethane resin as the top coatings. Also, the anti-corrosive function of these anti-corrosive coatings was well preserved for 1000 hr in the salt spray experiment.

We investigated heat stability of epoxy resin products and epoxy resin according to the influence hardener. The heat flow which shows the degree of thermal decomposition of the epoxy resin product and epoxy resin measured by using the differential scanning calorimeter (DSC). As a result, we found that in the case of heat stability for epoxy resin as hardener was added, the ratio of one to one (epoxy resin : hardener) was the most suitable in air condition and nitrogen atmosphere.

This paper is studied on the efficient purification process of dimethyl carbonate (DMC) from the melt layer crystallization combining crystallization process, sweating process and distillation recovery process. Purity and yield of DMC crystal depended mainly on the crystallization temperature, cooling rate, sweating termperature sweating rate. Through the optimization of crystallization and sweating operation, DMC crystal can be upgraded to very high purity over 99.9% and high yield over 85%.