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        검색결과 2,503

        1301.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various efforts have been explored to save the cost in many industrial fields. In order to recover the residual thermal energy from the flue gas, an extreme high efficiency heat exchanger is planning to install at a power plant. The gas temperature will be reduced to 40°C from 115°C. Thus gas buoyancy decreases, and dispersion of nitrogen oxides is expected to deteriorate as increasing relative humidity. In this study, the conversion of nitrogen monoxide to nitrogen dioxide and dispersion regime are investigated through computational modeling. Nitrogen dioxide which indicates 0.1 ppm at 85 m from the ground could be propagated to 620 m at 115°C of the flue gas, whilst when cooled down to 40°C, it expands up to 750 m. The ground level influence area showed more expansion of dispersion, approximately to 930 m.
        4,200원
        1302.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biodiesel is one of the most important renewable energy, since it is one of the most important alternative and eco-friendly energy source compared to fossil energy, especially for diesel engineequipped vehicles. It is now coming up for preparation of biodiesel as the alternative that applies the hetrogeneous catalyst, super critical state and various methods used in order to reduce the stages of the processes be converted and separation stages started from oil and fat which are originated from animals and wastes, and those new methods bring eco-friendly as well, though some of those are stand on research step so far. It is necessary that nation provides the tax exemption program for the supplier and strengthen the research system for the farming crops relate to fat and oil. It can improve the development of biodiesel which sustains stability against oxidation and keeps good mobility over the low temperatures in the winter season by new additives and develops new processes to show good harmony with diesel engine.
        4,300원
        1303.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,6-dihydroxyindole was easily oxidation with air and light Conditions. Availability of 5,6-dihydroxyindole was studied for hair dye as a precursor of melanin. This study used wet and dry coating process to stabilize 5,6-dihydroxyindole. In wet process used dimethicone and cyclometicone, the 5,6-dihydroxyindole had darkened through the drying process at 58℃. Wet coating process was inappropriate to stabilize the coating. In dry coating process, shea butter coating was stable until 3 days. Dextrin palmitate was most efficient ingredient to prevent oxidation by sun light and air until 7days. Oxidation test with 1.0% and 1.5% of dextrin palmitate was not different under conditions of sun light and air and was not dependent on contents. Vitamin E acetate under conditions of sun light and air, there were no significant effect in preventing oxidation.
        4,000원
        1304.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to process extraction and separation for polyglucose porpyran from pophyra yezoensis as high yield. The acidic porphyran solution was extracted with 0.1∼1N of α,β-dichloromaleic acid or α-chloromaleic acid of 2% solution as organic acid instead of inorganic acid at 60℃ and then porphyran was collection of high yield to acidic solution and it was neutralization treated with 0.1N of d-Ca(OH)2 solution and the mixture was conversion to porphyran salt form and treated with a shell powder of ouster and then added of ethanol as precipitator. It recovery porphyran contained of violet purple laver coloring matter was obtained as a crystalline and used for the next step without future purification to prepare of porphyran laver jam. so, The resulting porphyran and porphyran jam was characterized by it component and physical properties.
        4,600원
        1305.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, CO₂ adsorbent was produced for minimizing energy loss due to ventilation within the building. For improved selectivity about low concentration of CO₂ in multiple-use facilities, the ball type adsorbent was modified from a commercial zeolite, alumina, alkali metals and activated carbon with mixing LiOH, binder, and H₂O. We measured specific surface area, pore characteristic, and crystal structure of the modified adsorbent. Effects of alkalization on the absorptive properties of the adsorbents were investigated. Continuous column tests (2,000 ppm) and batch chamber tests (4m3, 5,000ppm) showed that the modified adsorbent indicated about the selectivity of CO₂ more than 9.7% (0.613 mmol/g) compared with ordinary adsorbents and CO₂ removal efficiency of 88.8% within l hour, respectively. It was estimated that the modified adsorbent was applicable to indoor environments.
        4,000원
        1306.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study shows the effect of 4% squid ink on the textural properties of squid during fermentation for 8 weeks at 10℃ or 32 days at 20℃ in 5% salt solution. Although the hardness and chewiness of the squid fermented with squid ink continuously decreased during fermentation, the degree of decrease was smaller than that of squid fermented without squid ink. We can conclude that squid ink inhibited the ripening of the low salt fermented squid.
        4,000원
        1307.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bioenergy is classified to one of the renewable energy resources such as solar, wind, hydro and tidal energies. It should be noted that all the renewable energies contribute to the reduction of greenhouse gases emission. In some cases, energy from wastes was also categorized as a renewable energy in our country even though it has only negligible effect on the emission reduction. In this paper, we tried to identify the bioenergy in order to follow the global indices of the renewable energy. The indices evaluated here were whether a resource is renewable, iogenic, biodegradable, combustible and organic. Biogenic and combustible were selected as the indices to identify the bioenergy. It was also suggested that combustible as an index can be exchangeable to organic.
        4,000원
        1308.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The conductive polymer composites recently became increasingly to many fields of industry due to their electrical properties. To understand these properties of composites, electrical properties were measured and were studied relatively. Electrical conductivity measurements showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in composites made of a conductive filler and an insulating matrix. It has been showed both experimentally and theoretically that the percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. This paper was to study epoxy resin filled with copper. The experiment was made with vehicle such as epoxy resin replenished with copper powder and the study about their practical use was performed in order to apply to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 3.065~13.325 in using copper powder. The weight loss of conductive composites happened from 350℃~470℃.
        4,000원
        1309.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Use of low bandgap polymers is the most suitable way to harvest a broader spectrum of solar radiations for solar cells. But, still there is lack of most efficient low bandgap polymer. In order to solve this problem, we have synthesised a new low bandgap polymer and investigated its interaction with the ILs to enhance its conductivity. ILs may undergo almost unlimited structural variations; these structural variations have attracted extensive attention in polymer studies. In addition to this, UV-Vis spectroscopy, confocal Raman spectroscopy and FT-IR spectroscopy results have revealed that all studied ILs (tributylmethylammonium methyl sulfate [N1444] MeSO4] from ammonium family) and 1-methylimidazolium chloride ([MIM]Cl, and 1-butyl-3-methylimidazolium chloride [Bmim]Cl from imidazolium family) has potential to interact with polymer. Further, protic ILs shows enhanced conductivity than aprotic ILs with low bandgap polymer. This study provides the combined effect of low bandgap polymer and ILs that may generate many theoretical and experimental opportunities.
        4,200원
        1310.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        NOx from the thermal power plants are NO and NO₂. This work investigated the chemical/physical characteristics and SCR efficiency of newly prepared catalysts including tungsten (WO₃), molybdenum (MoO₃) and antimony (SbO₃) based on vanadia(V₂O5) over titania(TiO2). As a result of the examination, the surface area of the catalysts promoted with additional metals was larger and the de-NOx efficiency also was enhanced with temperature. The most efficient catalytst was V₂O5/TiO₂-WO₃(10%) at 200 °C. Such a high efficiency could contribute to reduce the ammonia slip.
        4,000원
        1311.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The influences of scatterer and absorber in turbid material by light scattering on silica fume of additive were interpreted for the scattered intensity and wavelength. The molecular properties have been studied by Monte Carlo simulation in resin of New Austria Tunnel Method. It has been found that the effects of optical properties in scattering media could be investigated by the optical parameters(μs, μa ,μt). Monte Carlo Simulation method for modelling of light transport in the civil engineering and construction field was applied. The results using a phantom were discussed that the distance from source to detector is closer, and scattering intensity is stronger with those obtained through Monte Carlo Simulation. It may also aid in designing the best model for coatings and corrosion for the durability of metal constructions.
        4,000원
        1312.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sulfur content of diesel fuel has been cut down to under 10 ppm ULSD (ultra low sulfur diesel) level by environmental regulation with the aim of reducing exhaust emissions. This review discusses the methods and principles of sulfur reduction in diesel and presents an overview of new approaches for ultra-deep desulfurization. The deep HDS (hydrodesulfurization) problems of diesel streams is exacerbated by the inhibiting effect of co-existing aromatics, nitrogen compounds and H₂S. The new approaches to deep desulfurization includes non-HDS type processing schemes such as adsorptive, extractive and oxidative desulfurization.
        4,500원
        1313.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon coils could be synthesized using C₂H₂/H₂as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition (CVD) system. Prior to the carbon coils deposition reaction, two kinds of samples having different combination of Ni catalyst and substrate were employed, namely, a commercially-made Al₂O₃ceramic boat with Ni powders and a commercially-made Al₂O₃substrate with Ni layer. By using a commercially-made Al₂O₃ceramic boat, the synthesis of carbon coils could be enhanced as much as 10 times higher than that of Al₂O₃substrate. Furthermore, the dominant formation of the microsized carbon coils could be obtained by using Al₂O₃ceramic boat. The surface roughness of the supporting substrate of Al₂O₃ceramic boat was understood to be associated with the large scale synthesis of carbon oils as well as the dominant formation of the larger-sized, namely the microsized carbon coils.
        4,000원
        1314.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polymers in cosmetics are used to deliver desired attributes to skin and hair. Precisely constructed block and graft copolymers widen the range of available mechanical properties and compatibilities. Stimuli responsive hydrophobic polymers can be triggered to become hydrophilic by changes in their environment and this can confer waterproof properties at low temperature and easy water removal at higher temperatures. Transfer-resistant cosmetics can be possible due to silicone resins. The control of rheology properties in cosmetics gradually continue to be easy with copolymers. Durability of colors and fragrances for rinse-off products can be enhanced by delivery systems from complex coacervates. Polymeric anti-microbials promise product preservation while minimizing the concern of skin permeation. This article reviews recent trends in the use of polymers in cosmetics.
        4,300원
        1315.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the effects of feeding the broilers that are exposed to extreme heat stress by control of inverse lighting times with night restricted feeding of extreme heat diet(EHD1, 2: extreme heat diet) containing different amount of soy oil, molasses, amino acids and vitamin C on short chain fatty acid and blood lipid profile. 300 broiler chickens(Abaica strain) were randomized into four dietary treatment groups according to a randomized block design on the day they were hatched. The four dietary treatment groups were: T1(EHD 1, 10:00~19:00 Dark, 19:00〜10:00 Light), T2(EHD 2, 10:00〜19:00 Dark, 19:00〜 10:00 Light), T3(EHD 1, 09:00〜18:00 Dark, 18:00〜09:00 Light), T4(EHD 2, 09:00〜18:00 Dark, 18:00~09:00 Light). The body weight gain of the broilers was highest in T2, and high in order T1, T4, T3(p<0.05). Weights of the lymphoid organ, thymus and bursa of Fabricius were high in T1, T2 as compared to T3, T4 but spleen was lower in T4 than T1, T2, T3(p<0.05). Blood triglyceride, total cholesterol and glucose were higher in T1, T2 than T3, T4(p<0.05). LDL-C was high in orderT4, T3, T2, T1 but HDL-C showed the opposite trend(p<0.05). Blood concentrations of IgG, IgG and IgM were higher in T1, T2 than inT3, T4, but the corticosterone concentration decreased significantly in them. In T1 and T2, Lactobacillus in the feces increased, but total aerobic bacteria, E.coli, coliform bacteria was decreased rather significantly, compared with those in T3 and T4(p<0.05). Concentrations of acetic acid, propionic acid and total SCFA in cecum were high in order T2, T1, T3, T4, but butyric acid, isobutyric acid, valeric acid, isovaleric acid were lower in T1, T2 than in T3, T4 (p<0.05).
        4,200원
        1316.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the antidiabetic study effect in ethanol extract of Ailanthicortex(A.C) radici in Streptozotocin(STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose of 45㎎/㎏ dissolved in citrate buffer. The ethanol extract of A.C radici was orally administrated once a day for 7 days at a dose of 500㎎/㎏. The content of serum glucose, triglyceride(T.G), total cholesterol were significantly decreased in treated group compared to the those of STZ-control group. The content of hepatic glycogen and activity of glucokinase(GK) were significantly increased in treated group compared to the those of STZ-control group. but activity of glucose-6-phosphate dehydrogenase(G-6-PDH) was significantly increased. These results indicated that ethanol extract of A.C would have antidiabetic effect in STZ-induced diabetic rats.
        4,000원
        1317.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The crystallization of polypropylene (PP) particles in PP/decalin solution was conducted using the thermally induced phase separation(TIPS). During the control of particles sizes followed by the cooling of PP/decalin solution, particles were formed controllably, the concentrated PP resulted in an increase in the average diameter of PP particles. The effects of surfactants changes on particles sizes were investigated by using a field emission scanning electron microscope (FE-SEM). The PP crystals showed spherical shapes with a diameter 5∼18 μm. Additionally, as an effect of concentration of PP, the size distribution of the PP particles became broad with higher concentration of PP in the solution.
        4,000원
        1318.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        N,N,N-Trimethyl-10-nitrophenoxy decylammonium bromide (N10TAB) and N,N,N,N-Tetramethyl-bis-〔10-nitrophenoxy decyl〕-1,6-hexanediammonium dibromide (N10-6-10N), bearing aromatic nitrophenoxy group in the end of their hydrophobic chains have been prepared, and their properties in aqueous solutions have been studied by conductivity and H-NMR spectroscopy. Below the critical micelle concentration N10-6-10N form premicelle with two or three surfactant molecules. Beyond the critical micelle concentration two molecules have strong self-aggregation ability and form micelles of rather small size and with small aggregation numbers. H-NMR at different concentrations give the informations on the environmental changes of the surfactants on their micellization progress.
        4,000원
        1319.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to improve the selective oxidation reaction of gaseous ammonia at a low temperature, various types of metal-impregnated activated alumina were prepared, and also physical and chemical properties of the conversion of ammonia were determined. Both types of metal (Cu, Ag) impregnated activated alumina show high conversion rate of ammonia at high temperature (over 300℃). However, at lower temperature (200 ℃), Ag-impregnated catalyst shows the highest conversion rate (93%). In addition, the effects of lattice oxygen of the developed catalyst was studied. Ce-impregnated catalyst showed higher conversion rate than commercial alumina, but also showed lower conversion rate than Ag-impregnated sample. Moreover, 5 vol.% of Ag activation under hydrogen shows the highest conversion rate result. Finally, through high conversion at low temperature, it was considered that the production of NO and NO2, toxic by-products, were effectively inhibited.
        4,000원
        1320.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Coconut shell 계 상용 활성탄을 후처리하여 EDLC 전극재로 적용하였다. Coconut shell계 활성탄을 별도의 처리없이 EDLC 전극재로 사용하였을 때, 초기 무게용량 및 부피용량은 66 F/g 및 39 F/cc이었고, 100 사이클 충 방전을 반복한 후, 각각 54 F/g 및 32 F/cc로 감소하여 82%의 충 방전효율을 나타내었다. 충 방전 반복에 따른 용량의 감소폭이 크며, CV 특성에서 부반응에 의한 분극현상이 발생하여 전극재로 적합하지 않았다. 상업용 활성탄에 포함된 불순물을 효율적으로 제거하기 위하여 알칼리 및 산 처리를 하였고, 그 후 세공 분포와 표면의 산성 관능기 함량을 제어하기 위하여 질소 분위기에서 열처리하였다. 알칼리 및 질산처리 한 후 800℃에서 열처리한 전극재의 경우, 초기부피용량 44 F/cc, 100사이클 후 42 F/cc로서 실용화 가능한 수준의 높은 부피용량 및 95% 이상의 높은 충 방전 효율을 나타내었다.
        4,000원