• 한국응용과학기술학회지
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• 제25권2호
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• pp.226-231
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• 2008

In this study, benzoxazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization. Sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-benzoxazolium (inner salt) with triethyl orthobenzoate in the presence of triethylamine. The product was identified by using various analytical tools such as elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, $^1H$-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 507 nm. Therefore, it was concluded that benzoxazolo carbocyanine dye can be used as sensitizing dye for the spectral sensitization of photographic emulsion and color cosmetics.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.416-421
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• 2014

Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization. Sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium (inner salt) with triethyl orthopropionate in the presence of triethylamine. The product was identified by using various analytical tools such as elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, $^1H$-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 578nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as sensitizing dye for the spectral sensitization of photographic emulsion and color cosmetics.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2468-2473
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• 2018

Nitrogen-doped activated carbon fibers (ACFs) were prepared by chemical vapor deposition using melamine powder and acetonitrile for introducing quaternary nitrogen on the commercial ACFs, subsequently heated at $950^{\circ}C$ and activated by steam. Adsorption experiments of nitrate in aqueous solution were also conducted to evaluate adsorption capacity of the prepared ACFs using ion chromatography. The amount of introduced nitrogen content and nitrogen species on activated carbon fibers was examined by CHN elemental analyzer and X-ray photoelectron spectroscopy, respectively. As a result, adsorption capacity of quaternary nitrogen-doped ACF (ST-ML-AN-ST) was 0.75 mmol/g, indicating ca. two-times higher than that of untreated ACF (0.38 mmol/g). According to the adsorption data, the Langmuir isotherm model was the best fit. The prepared samples were also regenerated using hydrochloric acid. After regeneration, the adsorption capacity of the nitrogen-doped ACF (ST-ML-AN-ST) showed ca. 80% on average, implying that a portion of nitrates was adsorbed on the prepared ACFs irreversibly.

• Bulletin of the Korean Chemical Society
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• 제18권6호
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• pp.623-628
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• 1997

A layered perovskite oxide, $RbLa_2Ti_2NbO_{10}$, was prepared and investigated for proton exchange and intercalation behaviors. Its protonated form, $Hla_2Ti_2NbO_{10}$, exhibits the Bronsted acidity and reacts with organic amines. Polyoxonuclear cation, 4Al_{13}$, was then introduced into the interlayer by refluxing octylamine-intercalated compound with an $Al_{13}$ pillaring solution. These layered oxides were characterized by X-ray diffractometer, thermogravimeter, FT-infrared spectrometer and elemental analyzer. It is observed that the polyoxonuclear cation-pillared material exhibits a bilayer structure and is thermally more stable than organic counterpart at higher temperatures. The surface area of the pillared material annealed at 400 ℃ was the value of 25.1 m²/g.

• 환경영향평가
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• 제18권2호
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• pp.69-78
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• 2009

In order to provide fundamental data for developing greenhouse gas emission factor, we investigated power plants in Korea using B-C oil as Energy source. The power plant is a major source of greenhouse gases among the sectors of fossil fuel combustion, thus information of its emission factors is very essential to the establishment of control strategies for the greenhouse gas emissions. The caloric value of fuel was analyzed using calorimeter and the calorific value was 10,419 kcal/kg. The $CO_2$ concentration of flue gas and elemental analysis were conducted using GC-FID and elemental analyzer. The $CO_2$ emission factors from fuel analysis was 75,410 kg/TJ and that from $CO_2$ gas analysis was 94,265 kg/TJ. When compared with IPCC values, the emission factors by the fuel analysis was 2.5% lower, and that by $CO_2$ gas analysis was about 21.85% higher.

• 펄프종이기술
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• 제35권1호
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• pp.27-32
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• 2003

To understand the chemical structure of sewer sludge in comparison with commercial compost and charcoal used as a soil improver, it was carried out to analyse their ash contents and metal ions, and to elucidate the chemical structure of their residuals after a sequential treatment of alcohol-benzene(1:2) extraction in Soxhlet, 3% HCl reflux and 79% H₂SO₄ hydrolysis, using CHNS analyzer and solid C-13 NMR spectrometer. The results obtained were as follows: 1. Ash content of sludge was about 46% that is higher than those of compost (17%) and charcoal (4%). 2. The residual of sludge after a sequential treatment of HCl and H₂SO₄ hydrolyses had high ash content about 23%, too. 3. The sludge seems to be suitable to the soil improver because the content of heavy metal ions in sludge was near the compost and below the organic fertilizer standard. 4. Elemental composition of sludge residual after HCl-H₂SO₄ hydrolyes was C/sub 56/H/sub 91/O/sub 12/N₂S = (C/sub 6/H/sub 10/O/sub 5/)/sub 7/(C/sub 6/H₄)/sub 7/C₂H/sub 43/O₂N₂S, similar to C/sub 103/H/sub 122/O/sub 33/N/sub 6/S = (C/sub 6/H/sub 10/O/sub 5/)/sub 6/(C/sub 6/H₄)/sub 10/C/sub 7/H/sub 22/O₃N/sub 6/S of compost. 5. The sludge residual had proved to have both considerable aliphatic and aromatic groups, but the compost residual to have mainly aliphatic groups and the charcoal to have mainly aromatic groups, through the peak analysis of solid C-13 NMR charts. 6. So, the sewer sludge is proved to have a considerable amount of aromaticity like in woody biomass containing lignin.

• Korean Chemical Engineering Research
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• 제50권6호
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• pp.1043-1048
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• 2012

본 논문에서는 전기이중층 커패시터(EDLC, Electrical Double Layer Capacitor)의 전극소재로 쓰이는 활성탄소의 안정화를 위해 산소함유관능기를 최소화하고 질소함유관능기의 도입을 통해 유기용액계의 전해질을 가지는 EDLC의 축전용량을 개선하는 연구를 하였다. 주사전자현미경(SEM, Scanning Electron Microscopy), 후리에 변환 적외선분광기(FTIR, Fourier Transform Infrared), 자동원소분석기(EA, Elemental Analysis), 보엠(Boehm) 적정법, 충 방전 테스트 등의 분석법을 이용하여 그 결과를 확인하였다. 산 처리를 통하여 산소함유관능기가 도입되고 요소처리를 통하여 질소함유관능기가 도입되었음을 확인하였다. 질소함유관능기 도입을 통하여 EDLC의 g 당 방전용량을 2 mA 상승시켰으며 빠른 속도로 최대 충 방전 성능을 달성하였다. 반면 산소함유관능기는 전해질 속의 전하가 탄소표면에 흡 탈착되는 것을 방해하기 때문에 낮은 방전용량을 보였고, 충 방전 횟수가 늘어남에 따라 방전용량의 큰 감소를 보여주었다.

• 전기화학회지
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• 제12권1호
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• pp.34-39
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• 2009

니들 코크스의 활성화를 위해 $HNO_3$와 $NaClO_3$ 혼합용액에서의 산처리와 열처리를 행하였다. 산화처리 코크스와 열처리한 코크스의 미세구조는 XRD, FESEM, elemental analysis, BET, Raman spectroscopy를 이용하였으며, 전기이중층 거동은 충방전 분석을 행하였다. 니들 코크스는 산화처리 시간에 따라 산소의 중량 %의 증가와 함께 층간이 분리되어(001) 구조로 상변화가 일어나고, $200^{\circ}C$ 이상의 열처리에서 흑연구조 특성인(002) 구조로 되돌아갔다. 이들 산화처리 과정에서 층간에 관능기가 도입 되어 구조결함이 발생하고 1차 충전에서 전계 활성화에 의해 층간을 확장되어 2차 충전에서 전기이중층 용량을 발생 시키는 것으로 보인다. 24시간 산화처리후 $300^{\circ}C$ 열처리한 코크스의 2.5 V까지의 2 전극 기준에서 구한 활물질 중량 당 용량과 전극 부피 당 용량은 각각 32.1 F/g과 29.5 F/ml을 나타내었다.

• 한국자동차공학회논문집
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• 제22권4호
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• pp.152-159
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• 2014

Urea solution as a reductant of SCR has been widely used to reduce NOx emissions from diesel engine. But it has lots of problems which are freezing at low temperature due to liquid state, deposition of solid formation in the exhaust, dosing device, and complex package such as mixers for uniform concentration of ammonia. In order to overcome these obstacle, ammonium carbonate which is one of solid ammonium materials to produce ammonia gas directly by sublimation process is considered. Simple reactor with visible widow was designed to predict equilibrium temperature and pressure of ammonium carbonate. To simulate real operation conditions under automobile environment, several cycles of heating and cooling condition were settled, two different re-solidification materials were extracted from the reactor and visible window. Analytical study is performed to characterize these unknown materials by XRD(X-Ray Diffraction), FT-IR(Fourier Transform Infrared Spectroscopy), and EA(Elemental Analyzer). From analytical results, re-solidification materials from heating and cooling cycles are very similar to original material of ammonium carbonate.

• 환경영향평가
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• 제7권2호
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• pp.5-14
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• 1998

This study was performed to estimate interrelation between characteristics of sediment and nutrient releare from sediment in Dae-cheong lake. For the investigations, sediments were sampled in June and October 1997 at fish farms, embayment, and the main stream of Dae-cheong lake. Items for investigation are as follows; water content, weight loss on ignition(IG), porosity of sediment, Total Kjeldahl Nitrogen(TKN), content of element(H, N, C), nutrient release rate. Water content and porosity were measured to conjecture the physical trait and grain size. And weight loss on ignition was measured to determine the contents of organic substance. For the determination of nutrient release rate, $PO_4-P$ and $NH_4-N$ concentration of interstitial water and overlying water were measured. Release rate of nutrients which has direct influenced upon the water quality were 0.05-8.63mg-$P/m^2{\cdot}day$ and 4.99-36.56mg-$N/m^2{\cdot}day$. And it was found that release rate was measured higher in the 1st sampling than in the 2nd sampling. And for determination of the humus level of sediment, carbon and nitrogen content were measured by using elemental analyzer. Generally, C/N ratio is used to determine humus level of lake sediment. As a result of elemental analysis, C/N ratio was determined in the range of 7.64~11.55, so humus level of Dae-cheong lake sediment was estimated from mesohumic state to oligohumic state.