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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Society for Atmospheric Environment
Journal Basic Information
Journal DOI :
Korean Society for Atmospheric Environment
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Dec 1999
Volume 15, Issue 5 - Oct 1999
Volume 15, Issue 4 - Aug 1999
Volume 15, Issue 3 - Jun 1999
Volume 15, Issue 2 - Apr 1999
Volume 15, Issue 1 - Feb 1999
Volume 5, Issue 4 - 00 1999
Volume 5, Issue 3 - 00 1999
Volume 15, Issue E - 00 1999
Selecting the target year
and Activity for Propylene Partial Oxidation
도임자 ; 배영일 ; 손종락 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 161~161
was prepared by adding the
powder into a mixed aqueous solution of ammonium metavanadate and ammonium metatungstate followed by drying and calcining at high temperatures. The characterization of the prepared catalysts was performed using FTIR, solid-state
NMR, XRD, and DSC. In the case of calcination temperature at 773 K, for the samples containing low loading
below 18 wt % vanadium oxide was in a highly dispersed state, while for samples containing high loading
equal to or above 18 wt % vanadium oxide was well crystallized due to the
loading exceeding the formation of monolayer on the surface of catalyst. The
compound was formed through the reaction of
at 873 K and decomposed into
at 1073 K, which were confirmed by FTIR, solid-state
NMR, and XRD.
series catalysts exhibited the effective catalytic activity for propylene partial oxidation and the activity increased with increasing
content reaching a maximum at 12 wt %
Catalytic Oxidation Kinetics of Vapor Phase BTX over Pt/r-
이승범 ; 강성래 ; 이재동 ; 홍인권 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 170~170
The objective of this study was to depict the kinetic behavior of the platinum catalyst for the deep oxidation of BTX. The oxidation kinetics of BTX were studied on a 0.5% Pt /r-
catalyst at temperature ranging from 200 to 350℃ and the inlet concentration ranging from 133 to 333 ppmv. An approach based on the two-stage redox model was used to analysis the results. The conversions of BTX were increased as the inlet concentration was decreased and the reaction temperature was increased. The maximum deep conversion of benzene, toluene and m-xylene were 95.81%, 72.20% and 65.70% at 350℃, respectively. A simple multicomponent model based on two-stage redox rate model made reasonably good predictions of conversion over the range of parameters studied. The kinetic parameters of multicomponent model were independently evaluated from the single compound oxidation experiments. Toluene and m-xylene conversion was inhibited by benzene. The reaction model reveals that there is a competition between the two reactants for the oxidized catalyst. Benzene competes more effectively for the oxidized site and is thus oxidized more rapidly.
Electrochemical Characteristics of the Sulfonated Polysulfone Cation-Exchanger Membrane at Rotating Disk Electrode
박세용 ; 채만병 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 177~177
The transfer of copper ions into the Sulfonated Polysulfone (SPSF) cation-exchanger membrane coated on rotating disk electrodes in 0.007 M
solution was investigated with using cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Impedance value obtained from AC impedance method could be adapted to the proposed equivalent circuit model and was consistent with calculated values obtained by non-linear least square fitting method. Both transport (diffusion coefficient) and interfacial parameters (charge transfer resistance and double layer capacitance) were investigated with the reduction potential and rotation rate of electrode. The diffusion coefficient obtained by curve-fitting to experimental result is
at open circuit voltage. The charge transfer resistance, double layer capacitance, and bulk membrane resistance showed dependence on reduction potential, but no dependence on rotation rate of electrodes.
Temporal Electrochemical Behavior of a Steel Bar in Concrete Containing Inorganic Additions and Corrosion Inhibiting Admixtures
이용은 ; 장태선 ; 양우석 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 183~183
The effect of simultaneous incorporation of four different corrosion inhibiting admixtures and fly ash or ground granulated blast-furnace slag (ggbfs) in concrete mixture on the corrosion of its embedded steel bar was investigated by ac impedance spectroscopy and Tafel plot. The amounts of fly ash and ggbfs replacing portland cement were 20% and 40% by weight, respectively. Concrete specimens were exposed to alternating cycles of immersion in seawater and drying in air after 7 days' aging to accelerate the corrosion of the embedded steel bars. Electrochemical properties such as concrete resistance, film resistance, Tafel constants and the corrosion current density for each mixture were measured with time. The average corrosion current densities were estimated and compared with the visual inspection results. The incorporation of corrosion inhibiting admixtures generally improved the corrosion resistance of the embedded steel but with some exceptions. In terms of binder effect, 40% ggbfs blended concrete outperformed 20% fly ash blended concrete and ordinary portland concrete for most cases. Under the test conditions in this study, the performance of the corrosion inhibitors showed a dependence on the type of concrete binder: an inhibitor containing nitrite showed a good performance in ordinary portland concrete and while that containing a modified amino alcohol did in the fly ash or ggbfs blended concrete.
Fluorescence and ESR Studies for the Formation Mechanism of the Mesoporous MCM-41 Materials upon Microwave Irradiation
성형미 ; 김대성 ; 박상언 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 191~191
The mesoporous MCM-41 materials were prepared in short crystallization time (∼40 min) upon microwave irradiation in comparison with conventional hydrothermal heating method. The supramolecular templating mechanism of the MCM-41 formation upon microwave irradiation has been monitored by fluorescence and electron spin resonanace (ESR) spectroscopy. Pyrene as a fluorescence probe and 4-(N,N-dimethyl-N-hexadecyl)ammonium-2,2,6,6,-tetramethyl piperidinyloxy iodide (CAT16) as a spin probe were respectively dissolved into the myristyltrimethylammonium bromide (MTAB) surfactant solutions to form the MCM-41 precursor gels. These probes allow to observe the supramolecular interaction between surfactant and silicate species during the MCM-41 formation by monitoring fluorescence and ESR spectra of the probes in the MCM-41 precursor gels. The results elucidate the fast increase of hydrophobicity and microviscosity at the microenvironment of the probes in the micelles during the microwave MCM-41 formation due to the accelerated condensation of silicates onto the micelle surface in comparison with hydrothermal heating method. It seems that the fast formation of MCM-41 upon microwave irradiation is ascribed to the microwave-susceptible head groups of surfactant molecules in addition to fast dissolution of the precursor gel.
Dehydrogenation of Propane over Pd-Composite Membrane
노현석 ; 박민석 ; 장종산 ; 박용기 ; 박상언 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 198~198
Pd-composite membrane for selective permeation of hydrogen was prepared by the deposition of palladium on the asymmetric
tube purchased from US Filter corporation using the electroless plating method. The thickness of Pd layer was controlled to be less than 5 ㎛. The membrane exhibited high hydrogen permeabilities as temperature increased, and hydrogen selectivities over nitrogen at 400℃ were in the range of 12∼50 depending on pressure differences. When propane dehydrogenation reaction was carried out over the prepared Pd-composite membrane, propane conversion was 2 times higher than the equilibrium conversion by the alleviation of themodynamic equilibrium and the reaction temperature of 80℃ as well.
Comparison between Melt Crystallizations with Indirect and Direct Contact Cooling Methods
김광주 ; Alfons Mersmann ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 204~204
The effects of cooling mode on the crystal nucleation and growth kinetics have been explored through melt crystallization operations. Comparison between direct and indirect contact cooling methods has been made for the melt crystallization of n-dodecanol from n-decanol-n-dode-canol mixture. Direct contact coolants like air and water were investigated. The crystallizers were capable of being operated batchwise and continuously. The effect of operating modes on the crystallization kinetics was also studied. It was shown that crystal growth rates in all modes increase with the square of the supersaturation. The presence of direct contact coolants does not affect the nucleation characteristic due to their immiscibility and inert behavior with the melt. The comparison between crystallization kinetics for cooling modes was carried out by Mersmann's criteria.
Immobilization of Polyamine Ligands onto a Fluorophore Framework: Their Syntheses and Fluorescent Studies
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 212~212
Geometric immobilization of polyamine ligands is expected to change their binding properties toward metal ions. 1,8-Bis(1,4,7-triazacyclononylmethyl) anthracene (10) and 1,8-bis(1,5,9-triaza-cyclododecanylmethyl)anthracene (11) were synthesized from 1,8-bis(bromomethyl)anthracene (7) using appropriate azacrown type compounds. Purification of these compounds based on selective pH extraction methods is described. Chelation-enhanced fluorescence (CHEF) effect was observed when 10 complexed nonquenching metal ions such as Zn(Ⅱ) and Cd(Ⅱ). When compound 10 was titrated with Cu(Ⅱ), we could observe chelation-enhanced quenching(CHEQ) effect in 100% aqueous solution. On the other hand, compound 11 showed no effect on fluorescence by any metal ion examined.
A Study on the Synthesis of New Aminophosphonopeptides Containing P-N Amide Bonded Cephalosporin
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 218~218
A new kind of aminophosphonopeptides containing cephalosporin, diphenylmethyl 7-β-[O-alkyl phthalimidoglycylbenzylserylphosphonyl]-3-acetoxymethyl-3-cephem-4-carboxylates 1(a)-1(d), have been synthesized. O-Alkyl phthalimidoglycylbenzylserylphosphochloridate 9(a)-9(d), aminophosphonopeprides, were produced starting from benzyl 2-(N-Boc)aminoserinate (2) and benzyl 2-(N-t-Boc)amino-3-bromopropionate (4) by way of benzyl 2-amino-3-alkylphosphonopropionate 7(a)-7(d). The coupling of aminophosphonopeptides 9(a)-9(d) and diphenylmethyl 7-β-amino-3-acetoxymethyl-3-cephem-4-carboxylate yielded aminophosphonopeptides containing cephalosporin 1(a)-1(d). Antibacterial activities of these compounds were examined and relationship between structure and activities was studied. As a result, these compounds showed low antibacterial activities compared to cefotaxime used as control.
Reductive Amination of r-Keto Mono or Geminal Bisphosphonates with Primary Amines
정강연 ; 이미영 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 224~224
Reductive amination of carbonyl functionality to an amine is a very important tool in the synthesis of different kinds of amines. Commonly most of these processes have been applied for the carbonyl compounds, which contain various substituents except phosphonate functional group to an amine. During our study to synthesize aminated mono or bisphosphonate compounds as a drug we have tried several methods for the reductive amination of r-Keto mono or bisphosphonates. To get the desired product in a reasonable yield we have used, among various methods, the one-pot reductive amination process using sodium triacetoxyborohydride and acetic acid.
The Synthesis of New Pseudoceramides using Alkylketene Dimer and Their Physical Properties
박병덕 ; 이명진 ; 김윤 ; 이종기 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 228~228
As cosmetic raw materials, novel pseudoceramides have been synthesized and their physical properties have been investigated. The pseudoceramides, PC-4 (N-(2,3-dihydroxypropyl)-2-myristyl/palmityl-3-oxostearamide/arachidamide), and PC-5 (N-(1,3-dihydroxyisopropyl)-2-myristyl/palmityl-3-oxostearamide/arachidamide), were synthesized according to the reaction between alkylketene dimer (AKD) and alkanolamines. The reduced types of new pseudoceramides, PC-4R (N-(2,3-dihydroxypropyl)-2-myristyl/palmityl-3-hydroxystearamide/arachidamide) and PC-5R (N-(1,3-dihydroxyisoprophl)-2-myristyl/palmityl-3-hydroxystearamide/arachidamide) were prepared by the reduction of PC-4 and PC-5, respectively. An effective and economical synthetic pathway with high purity and high yield enabled the industrial production of these pseudoceramides. It was confirmed that there were several kinds of hydrogen bonding in them by the FT-IR study. X-ray diffraction (XRD) method and cross-polarized microscopy results make us confirm their intrinsic characteristics of lamellar structure formations. This intrinsic power to form the lamellar structure made it possible to form a pseudo-stratum corneum lipid emulsion, which shows the multi-lamellar structure.
Preparation of Water-swollen Hydrogel Membranes for the Separation of Carbon Dioxide
박유인 ; 이규호 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 235~235
Water-swollen hydrogel (WSH) membranes for the separation of carbon dioxide were prepared by dip-coating asymmetric porous polyetherimide (PEI) supporters with poly(vinyl alcohol) (PVA)-poly(acrylic acid) (PAA), followed by the thermal crosslinking of the PVA/PAA layer. The PVA/PAA layers with different blend compositions (PVA/PAA = 90/10, 80/20, 70/30 in wt %) were characterized with differential scanning calorimetry (DSC), infrared spectroscopy (IR) and the determination of their water swelling ratio. The permeabilities and the separation factors of carbon dioxide through these membranes were measured with a vacuum mode of downstream using a mass flow meter and gas chromatograph at different temperatures. When the feed composition of
mixture was 20/80 (vol %), the separation factors toward carbon dioxide were about 100 and the permeabilities of
(㎤/㎠·sec·cmHg). These membranes were stable at least up to 12 h.
The PEI Localization Effect on the Impact Properties of PEI toughened Carbon/Epoxy Composites
신승한 ; 장정식 ; 심정섭 ;
Journal of Korean Society for Atmospheric Environment, volume 5, issue 3, 1999, Pages 240~240
The impact properties of carbon/epoxy composites as a function of PEI content were investigated by means of a driven dart impact test. The impact properties of PEI toughened carbon/epoxy composites were enhanced with increasing the PEI content. This was mainly due to the suppression of matrix cracking by PEI particles. Although the same amount of PEI was used, the mechanical properties of carbon/epoxy composites were varied by the PEI localization. When the PEI toughened layer was located at the opposite side of impact point, the total impact energy of carbon/epoxy composites showed maximum value due to the easy deformation of PEI toughened layer. In addition, the flexural strengths of carbon/epoxy composites also depended on the PEI localization effect.