• 한국응용과학기술학회지
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• 제22권4호
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• pp.349-354
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• 2005

It is interesting to discover the reaction kinetics of the newly developed molybdenum containing catalysts. The dissociation/adsorption of nitrogen on molybdenum surface is known to be structure sensitive, which is similar to that of nitrogen on iron surface. The rates over molybdenum nitride catalysts are increased with the increase of total pressure. This tendency is the same as that for iron catalyst, but is quite different from that for ruthenium catalyst. The activation energies of the molybdenum nitride catalysts are almost on the same level, although the activity is changed by the addition of the second component. The reaction rate is expressed as a function of the concentration of reactants and products. The surface nature of $CO_3Mo_3N$ is drastically changed by the addition of alkali, changing the main adsorbed species from $NH_2$ to NH on the surface. The strength of $NH_x$ adsorption is found to be changed by alkali dopping.

• 한국표면공학회지
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• 제42권6호
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• pp.256-259
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• 2009

The wafer surface temperature is an important parameter in the etching process which influences the reaction probabilities of incident species, the vapor pressure of etch products, and the re-deposition of reaction products on feature surfaces. In this study, we investigated all of the effects of substrate temperature on the etch rate of $ZrO_2$ thin film and selectivity of $ZrO_2$ thin film over $SiO_2$ thin film in inductively coupled plasma as functions of $Cl_2$ addition in $BCl_3$/Ar plasma, RF power and dc-bias voltage based on the substrate temperature in range of $10^{\circ}C$ to $80^{\circ}C$. The elements on the surface were analyzed by x-ray photoelectron spectroscopy (XPS).

• 한국표면공학회지
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• 제49권4호
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• pp.331-338
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• 2016

In this work, anodic oxidation behavior of AZ31 Mg alloy was studied as a function of $Na_2CO_3$ concentration in electrolyte by voltage-time curves and observation of surface appearances and morphologies after the anodic treatments, using optical microscopy and confocal scanning laser microscopy (CSLM). The voltage-time curves of AZ31 Mg alloy surface and surface appearances after the anodic treatments showed three different regions with $Na_2CO_3$ concentration : region I, below 0.2 M $Na_2CO_3$ where shiny surface with a number of small size pits; region II, between 0.4 M and 0.6 M $Na_2CO_3$ where dark surface with relatively low number of large size burned or dark spots; region III, more than 0.8 M $Na_2CO_3$ where bright surface with or without large size dark spots were obtained. The anodically treated AZ31 Mg alloy surface became significantly brightened with increasing $Na_2CO_3$ concentration from 0.5 M to 0.8 M which was attribute to the formation of denser and smoother surface films. Pits and porous protruding reaction products were found at relatively large size and small size spots, respectively, on the AZ31 Mg alloy surface in low concentration of $Na_2CO_3$ less than 0.2 M. The formation of pits is attributed to the result of repetition of the formation and detachment of porous anodic reaction products. Based on the experimental results obtained in this work, it is concluded that more uniform, denser and smoother surface of AZ31 Mg alloy could be obtained at more than 0.8 M $Na_2CO_3$ concentration if there is no other oxide forming agent.

• Journal of the Korean Wood Science and Technology
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• 제41권6호
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• pp.497-506
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• 2013

유칼립투스(Eucalyptus globulus)의 반탄화 최적조건을 탐색하기 위하여 반응표면분석법을 이용하였다. 반탄화 바이오매스의 탄소함량은 반탄화 정도를 나타내는 severity factor (SF)에 따라 증가하였으며 바이오매스에 포함된 수소와 산소의 함량은 감소하였다. 반탄화 바이오매스의 발열량은 조건에 따라 20.23~21.29 MJ/kg을 나타냈으며 처리 전 바이오매스와 비교하여 1.6~6.9% 에너지함량이 증가한 것으로 나타났다. 바이오매스의 중량감소율은 SF 증가에 따라 증가하였다. 에너지수율에서 반탄화 온도는 중요한 인자로 작용하였으며 상대적으로 반응시간에 대한 영향은 낮았다. 최대 에너지수율은 낮은 SF에서 반탄화를 수행하였을 때 얻을 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.695-700
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• 2007

The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans (GenBank access code AF222787) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein Aga1p. The surface display of CFTase was confirmed by immunofluorescence microscopy and enzymatic assay. The optimized reaction conditions of surface-displayed CFTase were as follows; pH, 8.0; temperature, $50^{\circ}C$; enzyme amount, 30 milliunit; substrate concentration, 5%; inulin source, Jerusalem artichoke. As a result of the reaction with inulin, cycloinulohexaose was produced as a major product along with cycloinuloheptaose and cycloinulooctaose as minor products.

• 대한화학회지
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• 제61권4호
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• pp.157-162
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• 2017

In the present study, nanocrystalline mixed metal oxide, $CuMnO_3$ catalyst have been synthesized by mechanochemical method with green chemistry approach. The synthesized catalyst was characterized by analytical techniques including FTIR, XRD, SEM, TEM and BET surface area. The synthesized catalyst shows high surface area is $121.06m^2/g$ with particle size 18 nm. The one pot four component synthesis of substituted 2-phenyl-4(3H) quinazolinone from the reaction of anthranilic acid, benzoyl chloride, hydrazine hydrate and substituted benzaldehyde in presence of $CuMnO_3$ nanocatalyst has been carried out. It affords the corresponding products with high yield (76-95%) in very short reaction time. All the obtained products were characterized with $^1HNMR$, $^{13}CNMR$, FTIR and EIMS.

• 한국재료학회지
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• 제12권11호
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• pp.850-855
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• 2002

Silica powders were prepared from $SiCl_4$-$H_2$O system by chemical vapor deposition process, and investigated on size control of the products with reaction conditions. The products were amorphous and nearly spherical particles with 130nm~50nm in size. The size distribution became narrow with the increase of [$H_2$O]/[SiCl$_4$] concentration ratio. The particle size decreased with the increase of reaction temperature, [$H_2$O]/[SiCl$_4$] concentration ratio and total flow rate. The specific surface area measured by BET method was about three times larger than that of electron microscope method.

• 한국응용과학기술학회지
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• 제10권2호
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• pp.81-90
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• 1993

The Surfactants composed of acylated aterocollagen which is produced by the acylation of the side chain amino radicals of aterocollagen with an aliphatic acid having 12 to 18 carbon atoms will be discussed in this study. This condensation is done at moderate reaction temperature (<$25^{\circ}C$) in aqueous alkaline solution. The products of this reaction were identified by UV/VIS spectroscopy and infrared spectroscopy. For these compounds, surface active properties and physical properties including isoelectric point, Krafft point, surface tension, critical micelle concentration(cmc), foaming power, viscosity behaviour, water holding capacity, skin irritation and emulsifying power were measured respectively. The experimental results received that the products have a good emulsifying power, excellent water holding capacity while having low skin irritation. Thus, these derivatives will be expected to be used as an emulsifying agent for O/W type cosmetic emulsion.

• 한국식품과학회지
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• 제18권2호
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• pp.88-92
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• 1986

Bioluminescence방법에 의하여 세균내에 존재하고 있는 ATP를 추출하여 그양을 정량분석하므로서 제육표면에 생존하고 있는 세균수를 신속하게 측정하는데 응용될 수 있는 가능성을 조사하기 위하여 본 실험을 실시하였으며, 그 결과는 1. Luciferin-luciferase에 작용하는 ATP농도가 $10^{-10}M$부터 $10^{-6}M$까지 증가함에 따라 발생된 빛의 양도 비례적으로 증가했다. 2 . 계육에서 분리동정된 부패균인 E. coli, H, alvei, P. putida, A. hydrophila에서 추출된 ATP 농도와 세균수와의 관계는 거의 일직선으로 나타난다. 3. E. coli에 있는 ATP양은 생존중 거의 변화하지 않는 것으로 나타났다. 4 계육의 저장기간동안 증식된 세균수에 따라 ATP 농도도 비례 적으로 증가되며 이때 상판계수(r)는 0.95로 나타났다. 5. 계육에 오염된 세균수와 ATP 농도와의 관계에서 볼 때 ATP농도가 $10^{-7}M$부근에서부터 부패가 시작된다고 사료된다. 6. 개발된 방법에 의하여 계육표면에 존재하는 세균의 ATP 농도를 측정하여 세균수를 간접적으로 신속히 ( 1시간내) 조사할 수 있다.

• 한국표면공학회지
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• 제32권3호
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• pp.336-339
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• 1999

Photo-excited $TiO_2$ surface has a strong ability to induce various chemical reactions. Our study concentrates mainly on the utilisation of light energy to induce reactive radicals for environmental protection application. For instance, we have successfully used TiO$_2$ to break down foul smelling substances in air. In order to retain and separate the $TiO_2$ catalyst from the reactants and products, $TiO_2$ was immobilised by fixing onto various substrates. $TiO_2$ catalyst coated onto glass, wall paper and painted panel was found to show significant deodorising effect. The deodorising effect continues as long as$TiO_2$ is exposed to light irradiation.