간행물
한국응용과학기술학회지 KCI 등재 The Korean Society of Applied Science and Technology
- 발행기관 한국응용과학기술학회(구 한국유화학회)
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-9098 (Print)2288-1069 (Online)
- 수록기간 1984 ~ 2024
- 주제분류 공학 > 화학공학 공학 분류의 다른 간행물
- 십진분류KDC 575DDC 665
권호리스트/논문검색
Vol.25 No.4 (2008년 12월) 16건
1.
2008.12
구독 인증기관 무료, 개인회원 유료
A group of new N,N-bis(5-acetylpyridin-2-yl)phenylamine derivatives was synthesized in good yield applying an optimized Buchwald-Hartwig amination protocol. The synthesized compounds showed UV absorption maxima in the range of 320-360 nm, and showed good luminescence at dilute concentrations in the blue region of the spectra (in the range of 480-497 nm). They showed also a bathochromic shift associating the increase in solvent polarity. The synthesized compounds could be investigated for use in OLEDs or as potential monomers for PLEDs.
4,000원
2.
2008.12
구독 인증기관 무료, 개인회원 유료
Transesterification of fat of Tra catfish with methanol in the presence of the KOH catalyst yields fatty acid methyl esters (FAME) and glycerol (GL). The effects of the reaction temperature and reaction time on rate constants and kinetic order were investigated. Three regions were observed. In the initial stage, the immiscibility of the Tra fat and methanol limited the reaction rate, hence this region was controlled by the mass transfer. Subsequent to this region, produced FAME like a co-solvent made the reaction mixture homogeneous, therefore the conversion rate increased rapidly so it was controlled by the kinetic parameters of the reaction until the equilibrium was approached in the final slow region. A second-order kinetic mechanism was proposed involving second regions for the forward reaction. The rate determining step for the overall KOH catalyzed-methanolysis of Tra fat was the conversion of triglycerides (TG) to diglycerides (DG). This rate constant was increased from 0.003 to 0.019min-1 when the reaction temperature was increased from 35 to 60℃. Its calculated activation energy was 14.379 (kcal.mol-1).
4,200원
3.
2008.12
구독 인증기관 무료, 개인회원 유료
The p-dioxanone can be used to make a variety of commercially useful products particularly where biodegradability is desired, such as fibers, sutures, molded articles, containers, medical devices and surgical clips, film and compostable trash bags. The mole fraction solubility of p-dioxanone in various solvents such as acetone, ethylacetate, tetrahydrofuran, methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol were measured over the temperature range from 263.05 K to 288.45 K. The solubility of p-dioxanone increases with increasing polarity of the solvents.
4,000원
4.
2008.12
구독 인증기관 무료, 개인회원 유료
For recipe prediction of colorant proportion showing nonlinear behavior, we modeled the effects of colorant proportion of basic colors on the target colors and predicted colorant proportion necessary for making target colors. First, colorant proportion of basic colors and color information indicated by the instrument was applied by a linear model and a multi-layer perceptrons model with back-propagation learning method. However, satisfactory results were not obtained because of nonlinear property of colors. Thus, in this study the neuro-fuzzy model with merit of artificial neural networks and fuzzy systems was presented. The proposed model was trained with test data and colorant proportion was predicted. The effectiveness of the proposed model was verified by evaluation of color difference(δE).
4,000원
5.
2008.12
구독 인증기관 무료, 개인회원 유료
Essential fatty acids (EFA) are fatty acids that must be obtained from the diet because they can not be biosynthesized by human or animals. Gamma fatty acids contain gamma-linolenic acid (GLA, 18:3n-6) and dihomo-gamma-linolenic acid (DHGLA, 20:3n-6) as intermediate metabolites of linoleic acid (LA, 18:2n-6), which is an EFA found in vegetable oils. GLA is an important essential fatty acid that is required by human and animals to function normally. Recently, studies have indicated that GLA may be an essential component of the cell membrane, as well as an active component of dietary supplements and medicine. GLA must beadministered through the diet because it is converted into DHGLA in the body quickly and completely. DHGLA is a key material involved in the metabolism of LA. GLA is biosysthesized by the rate limiting step of δc6-desaturase, which is an enzyme that desaturates LA, there by allowing it to be converted into DHGLA via chain elongation. In addition, DHGLA exerts bioactive effects via action as a precursor of eicosanoid series 1. Breast milk contains an abundant amount of GLA; however, GLA is also available directly in evening primrose oil, black currant seed oil, borage oil and hemp seed oil. In addition, GLA enriched animal and plant can be produced using biotechnology, and highly pure GLA can be extracted using supercritical fluids, such as supercritical carbon dioxide, which will allow economically feasible production of GLA for use in medicines.
4,500원
6.
2008.12
구독 인증기관 무료, 개인회원 유료
Methyl methacrylate(MMA) was grafted onto microcrystalline cellulose(MCC) with ceric ammonium nitrate(CAN) as a redox initiator at the various conditions. The cellulose triacetate(CTA) composite films added MCC and MMA-grafted MCC powders were prepared on a glass plate. The graft yield(GY) and graft efficiency(GE) of the grafted MCC were calculated with the simple equations by the weight balance method. The double bond of C=O on the grafted MCC surfaces was confirmed by the fourier transform infrared spectroscopy with attenuated total reflection(FT-IT ATR) spectrophotometer. After grafting, the degree of crystallinity of cellulose powders was decresed by judging from x-ray diffraction(XRD) data. Scanning electron microscope(SEM) photos showed the only solvent and CAN solution could change the roughness of MCC powders and the effect of powder dispersions in composite matrix. The tensile strength of MCC/CTA composite films was decreased with increase of MCC powder contents. When 5% grafted MCC was added, the tensile strength of grafted MCC/CTA composite films was increased from 82.3 MPa to 97.2 MPa. The thermal property of powders was also analyzed by the thermogravimetric analysis(TGA).
4,000원
7.
2008.12
구독 인증기관 무료, 개인회원 유료
The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of three different types of ionic liquid : quarternary ammonium salt, alkyl pyridinium salt, and alkylimidazolium salt. Ionic liquids of different alkyl groups (C3, C4, C6 and C8) and anions (Cl-, Br- and I-) were used for the reaction which was carried out in a batch autoclave reactor at 60~120℃. The catalytic activity was increased with increasing alkyl chain length in the order of C3 〈 C4 〈 C6. But the ionic liquid with longer alkyl chain length (C8) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the ionic liquid catalysts, the BGE conversion decreased in the order Cl- 〉 Br- 〉 I-.
4,000원
8.
2008.12
구독 인증기관 무료, 개인회원 유료
It is inevitable to use chemical germicidal agents like paraben, imidazolidinyl urea and phenoxyethanol to preserve the emulsions which is usually used in cosmetics. Although these chemical preservatives are good enough to reduce the microbiological contamination, they are irritative, allergenic to the skin. Several kinds of polyols are used in cosmetics as moisturizer and solvent. In this study, we evaluate the effects of polyols on anti-microbial activities, safety and resistant index. MIC(minimal inhibitory concentration) of polyols determined against 6 germs including Staphylococcus aureus. The order of MIC was PG ≅ DPG ≅ 1,3BG 〉 HG 〉 1,2-PD 〉 1,2-HD ≅ 1,2-OD. The 2~3 wt% of 1,2-HD(hexanediol) shows good anti-microbial effects in emulsions without allergenic response. Resistant index of 1,2-HD was less than 2 and this value was smaller than that of chemical preservatives. The mechanism of antimicrobilogical effect might be disturb the membrane of germs by investigating using electron microscope. Added to that, using this paradigm, low preservative contents, paraben-free system, and even preservative-free systems can be expected from these results.
4,000원
9.
2008.12
구독 인증기관 무료, 개인회원 유료
The acrylic coating emulsions were prepared by the emulsion polymerization to protect the surface of steel plate from the corrosion chemicals like acid, base and salt water. MMA(methyl methacrylate), styrene, BA(butyl acrylate), and 2-HEMA(2-hydroxyethyl methacrylate) were used as monomer. KPS(potassium persulfate) and SBS(sodium bisulfite) as redox initiator and SDBS(sodium dodecylbenzene sulfonate) as emulsifier were used on the emulsion polymerization reaction. The most stable in-situ coating was obtained when 10% of MMA was added. Both particle size and quantity in emulsion were decreased as increasing the mount of SDBS. the most stable prepared coating emulsion with polyisocyanate crosslinker showed very high anticorrosion properties on the coated steel layer to salt water, whereas no significant improvement of anticorrosion property to acdic and basic condition it showed.
4,000원
10.
2008.12
구독 인증기관 무료, 개인회원 유료
To investigate the synergy effect on the pyrolysis of mixture of polyethylene(PE) and polystyrene(PS), the pyrolysis of PE, PS and the mixture of PE-PS was carried out in a batch reactor at the atmospheric pressure and 450℃. The pyrolysis time was from 20 to 80 mins. The liquid products formed during pyrolysis were classified into gas, gasoline, kerosene, gas oil and heavy oil according to the distillation temperatures based on the petroleum product quality standard of Korea Institute of Petroleum Quality. The analysis of the product oils by GC/MS showed that the new components produced by mixing were not detected. The synergy effect according to mixing of PE and PS did not also appear. The conversion and yield of mixtures were in proportion to the mixing ratio of sample.
4,000원
11.
2008.12
구독 인증기관 무료, 개인회원 유료
This research is related to the process of refining the raw material, industrial 2-propanone to the 2-propanone of the electronic grade. With this view, the high purity of 2-propanone was obtained through the complex preprocessing(physical adsorption method), distillation process and membrane-filtration of distillate. Impurities were identified by GC and UV, and then we assayed the water content in 2-propanone passing adsorption step made of activated carbon and Zeolite 4A. Furthermore, the distillation was performed with the packed column distillation apparatus to eliminate impurities such as acetaldehyde. Particulates were removed by reduced-pressure filtration through 0.5μm membrane filter and the number of the particulates was measured by particulate counter to confirm the removal of impure particles.
4,000원
12.
2008.12
구독 인증기관 무료, 개인회원 유료
We make high-functional inorganic-composite pearlescent pigment material that coated with carmine on the plate-type particle such as mica. In this experiment, we synthesized composite powder using pH control precipitation method. We make an experiment with changing as synthesis factors that are concentrations of starting material and precipitation materials. We analyzed pearlescent powder's shape, and crystallization with FE-SEM, XRD, and EDS. Optimum condition for preparation of carmine coated mica pearlescent pigment is pH 4.5~5.5.
4,000원
13.
2008.12
구독 인증기관 무료, 개인회원 유료
In this study, positive plates of lead acid battery of Pb-Ca alloy and Pb-Ca-Sn alloy were fabricated and the mechanical characteristics of positive plates were measured. This study observed how the changes of content of Ca & Sn affect interface corrosion which is located in between grid & active materials and lead acid batteries as well. The mechanical characteristics of grid alloy is better when Ca is 0.05 wt.% then 0.1 wt.%. This study said that the corrosion rate between the active material based on the charge/discharge cycle of lead acid battery and grid interface is much faster than a grid which contains Sn. And furthermore, according to the study the rate 30 of Sn/Ca which is added to grid shows the best performance.
4,000원
14.
2008.12
구독 인증기관 무료, 개인회원 유료
To prepare a solution type acrylic pressure-sensitive adhesive, quarter polymers were synthesized from butyl acrylate(BA), 2-ethylhexylacrylate(2-EHA) as a base monomer, methyl methacrylate(MMA) as a comonomer, each of methacrylic acid(MAA), acrylic acid(AA) as a functional monomer. Acrylic solution type pressure-sensitive adhesives(PSA's) of isocyanate derivative crosslinking PSA's were prepared by crosslinking of BEMM, BEMA with toluene-2,4-diisocyanate. The structure of adhesive was identified by FT-IR. The viscosity was measured by using Brookfield DV-III and molecular weight was measured by using gel permeation chromatography. The physical properties of polyethylene film coated with BEMMT, BEMAT were measured as a function of the concentration. As the result, BEMMT(0.6, 0.8), BEMAT(0.6) showed peel adhesion of 160~180 gf/25 mm width and shear adhesion of more than 24 hours, and tackiness of 4/32~6/32 which was relevant to commercial usage.
4,000원
15.
2008.12
구독 인증기관 무료, 개인회원 유료
In order to fine antioxidant and whitening agent source from nature, the comparisons of antioxidative activity and tyrosinase inhibitory activity were carried out for various ethanol extract on Polygoni Multiflori Radix, Polygonati Rhizoma and Ephedrae Herba. Comparing for three ethanol extracts, the highest electron donating ability was found at Polygonati Rhizoma (86.6%), but, the highest SOD-like ability, at the Ephedrae Herba (47.8%). Xanthine oxidase experiment exhibited 95.7% of hindrance effect in Ephedrae Herba, and 84.0% in Polygonati Rhizoma. A tyrosinase inhibitory activity assay was conducted to evaluate the whitening effects of the extracts, The tyrosinase inhibitory activity was 6.5% in the Polygoni Multiflori Radix, 32.6% in the Polygonati Rhizoma, 64.0% in the Ephedrae Herba. Based on these results, we suggest that the ethanol extracts of Polygoni Multiflori Radix, Polygonati Rhizoma and Ephedrae Herba can be used as food and cosmetic ingredients.
4,000원
16.
2008.12
구독 인증기관 무료, 개인회원 유료
It is well understood that developing new drugs is one of the highest value-added businesses in a country; however, the current governments' spending in pharmaceutical research and development(R&D) is minimal in Korea. This paper suggests that different governmental bodies should take in charge of different stages of the R&D process in order to maximize the use of limited government research funding. First, during the initial phase of the drug development, including clinical trials, the Ministry of Education, Science and Technology is the most appropriate governmental organization to support the research. For later procedures such as supporting the industries for exporting developed drugs, legislative approvals, and building infrastructure for future clinical trials should be supported by the Ministry of Knowledge and Economy and the Ministry of Health and Welfare along with the Korea Food and Drug Administration(KFDA). The KFDA, which is the main governmental agency approving newly developed drugs in the market, will need to take a crucial responsibility in the initial phase of the pharmaceutical R&D by guiding the industries with timely and proper information. As a first step, it is recommended to set up and operate a center for supporting new drugs, so that the industries can facilitate the development of marketable drugs which meet customers' needs. Later, in order to expedite the process of exporting and getting approvals of the newly developed drugs from foreign countries, it is necessary to develop new approval system, which includes introduction of the Good Manufacturing Practice (GMP), mandatory validation system, and education program for supporting expertise. Lastly, the KFDA needs to take an active role in developing Korean pharmaceutical industries by communicating with other foreign governments with regards to the globalization of the Korean pharmaceutical industries. For example, as a follow up after the Free Trade Agreement(FTA), active discussion on GLP of Mutual Recognition Agreement(MRA) with the United States of America, should be seriously considered.
5,100원
