• 한국수산과학회지
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• 제37권5호
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• pp.359-365
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• 2004

To study the lipid adsorption characteristic of chitosans with different molecular weights and the degrees of deacetylation, in vitro test and near-infrared (NIR) spectroscopic analysis have been performed for the measurement of lipid adsorption characteristics of chitosan. The degrees of deacetylation in chitosans were $70{\%},\;85{\%}\;and\;92{\%}$ at different deacetylation times (1 hr, 2 hrs, 3 hrs), respectively. The molecular weight of each chitosan was controlled by enzymatic hydrolysis, and then the molecular weight of the chitosan was 4 kDa. The bulk density, water holding capacity and fat binding capacity of each chitosan powder were $96.2-504.0{\%},\;374.4-1217.9{\%},\;and\;307.0-659.3{\%}$, respectively. The higher molecular weight of chitosan was exhibited the lower bulk density and the higher water and fat binding capacities. Bindinf capacities of chitosan powders to bile salts, cholesterol and linoleic acid were $41.2-63.3{\%},\;40.8-67.4{\%},\;42.6-72.6{\%}$, respectively. In NIR spectrum of lipid adsorbed chitosan the occurrence static eletronical binding between chitosan and lipid was identified by NIR spectrum peak induced from combination of carboxylic group in lipid and amino group in chitosan. In conclusion, the higher degree of deacetylation and molecular weight of chitosan showed the higher lipid binding capacity and the lipid adsorption of chitosan were occurred by combination of carboxylic group in lipids and amino group in chitosan.

• 한국대기환경학회지
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• 제26권4호
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• pp.357-366
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• 2010

The purpose of this study is to evaluate a method for the measurement of N,N-Dimethylformamide (DMF) and to apply the method to the ambient air samples. For the determination of DMF together with other general VOCs (e.g., benzene, toluene, and xylenes), adsorption sampling and thermal desorption with GC/MS was used in this study. The sampling and analytical approaches tested in this study showed a good repeatability and linearity with lower detection limits of less than 0.35 ppb. Field measurements were carried out at three industrial sites (Daegu-Seongseo, Siwha and Banwall industrial complexes) and one residential site in Daegu city during a period from October 2006 to November 2008. DMF was detected in 71.8% of the total samples from the Seongseo industrial complex, well known for textile industry. In contrast, DMF was detected in only 20.4% and 12.9% of all the samples from the other two sites in Banwall and Siwha industrial complexes, respectively. This implies that sources of DMF should be strongly associated with textile industry. The mean concentration of DMF also appeared to be the highest in Seongseo site (5.95 ppb), followed by a residential site in Daegu (3.28 ppb), Banwall (0.88 ppb) and Siwha (0.55 ppb). In this study, we demonstrated the environmental significance of DMF in urban ambient air. To our knowledge, the DMF measurement introduced in this paper is the first case of an official report in Korea.

• 한국토양비료학회지
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• 제26권3호
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• pp.160-171
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• 1993

Ultisol(필리핀의 Luisiana 토양)과 Alfisol(필리핀의 Maahas 토양)및 Inceptisol(한국의 용지통) 토양의 표면전하 특성을 전위차 측정법과 역적정법 및 이온흡착법 등의 세가지 방법으로 정량하였고 분석법간의 차이를 비교한 결과는 아래와 같다. 1. 이온흡착법(또는 CEC-AEC method)으로 구한 PZNC(point of zero net charge)값은 Luisiana토양과 Maahas 토양 및 용지통에서 각각 3.1, 2.2 및 2.9였다. 따라서 이들 토양의 자연 pH조건에서는 음전하를 보였다. 2. 전위차 적정법과 역적정법에서 구한 PZSE(point of zero salt effect)값은 Maahas토양 외의 두 토양에서 일치하였다. 3. PZNC값은 PZSE값에 비해 모든 토양에서 낮았는데 이는 영구음전하의 영향으로 생각되었다. 한편 Uehara and gillman(1980)의 이론에 의해 구한 영구음전하는 Luisiana 토양과 Maahas 토양 및 용지통에서 각각 2.6, 4.5 및 0.4me/100g로 pH 7에서 측정된 CEC중 상당히 적은 부분을 차지하였다. 4. 역적정법은 pH가 너무 높거나 낮을 때 전위차 적정법이 표면전하를 과다 평가하는 결점을 보완해 주었으나 여전히 이온흡착법에 비해 과대 평가하고 있어 영구전하의 영향이 큰 보통 토양에서는 이온흡착법의 사용이 나을 것으로 판단되었다.

• 한국가구학회지
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• 제19권6호
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• pp.447-451
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• 2008

This study was carried out to know the difference of vapor transmission on the thickness of Paulownia wood(Paulownia tomentosa). The behavior of moisture transmission of wood thickness direction is generally estimated by vapor permeability and vapor transmission resistance. In general, Paulownia wood is known to use of inside material for furniture making, because of the excellent ability of vapor adsorption and/or desorption. Quarter sawing Paulownia wood material is prepared and the thickness is 6.0mm, 7.0mm, 8.0mm, 9.0mm, 10.0mm, respectively. The measurement of vapor transmission were conducted by the "cup method" in accordance with JIS(Japanese Industrial Standard) Z-0208. The experiment was made in the condition of 49.8mmHg vapor pressure difference and $40^{circ}C$ at constant temperature. From the experiment results, it was considered that Paulownia wood is very stable on moisture variation and any other material conditions. In this experiment we found that the vapor permeability and vapor permeance was reduced with the increase of wood thickness to vapor direction and vapor transmission resistance and specific vapor transmission resistance was increased with the increase of wood thickness to vapor direction. Besides moisture contents of adsorption and desorption side were about 5 percent and 14 percent, respectively. Mean value was 9.5 percent and about 10 percent in dry oven method. Moisture gradient was reduced with the increase of wood thickness for a small moisture difference of adsorption and desorption side.

• 한국표면공학회지
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• 제52권3호
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• pp.130-137
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• 2019

In this study, the cobalt sulfide (CoS) nanosheet on stainless steel as a supercapacitor electrode is synthesized by using a facile successive ionic layer adsorption reaction (SILAR) method. The number of cycles for dipping and rinsing can control the nanosheet thickness of CoS on stainless steel. Field emission-scanning electron microscopy (FE-SEM) showed a layer structure of CoS particles coupled as agglomeration. And x-ray diffraction (XRD) showed the crystallinity of the CoS nanosheet. To investigate the characteristics of the CoS nanosheet electrode as the supercapacitor, analysis of electrochemical measurement was conducted. Finally, the CoS nanosheet of 70cycles on stainless steel shows the specific capacitance ($44.25mF/cm^2$ at $0.25mA/cm^2$) with electrochemical stability of 78.5% over during 2000cycles.

• 한국대기환경학회지
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• 제18권2호
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• pp.127-137
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• 2002

Phenolic compounds in air are toxic even at their low concentrations. We had evaluated a total of five phenolic compounds (Phenol, o-Cresol, m-Cresol, 2-Nitrophenol and 4-Chloro-3-methylphenol) in artificial air using a combination of ATD/GC/MS. To compare the adsorption efficiency of these phenolic compounds, three adsorbents (Tenax TA, Carbotrap and Carbopack B) were tested. Tenax TA adsorbent was most effective of all the adsorbents used for the efficiency test. Five phenolic compounds were found to be very stable on adsorbent tubes for 4 days at room temperature. Detection limit of five phenolic compounds ranged from 0.05 to 0.08 ppb (when assumed to collect 10 L air). The calibration curve was linear over the range of 22∼ 164 ng. The reproducibility was less than 4%. Sampling of duplicate pairs (DPs) was made to demonstrate duplicate precision and sampling efficiency.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.143-148
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• 2005

Plastics and vinyl resin is generally used in the various fields of industry and daily life. Except incineration, most waste has been disposed finally in landfill and the leaching of plasticizer as DEHP(di 2-ethylhexyl phthalaet) has been taken place in the landfill. DEHP had been found. for endocrine disrupter by World Wild Life Fund and Japan. In this study aimed at estimation of capacity of adsorption and measurement of phthalate ester in the residual soil. The residual soil had been gathered from three closed landfill which was under stabilization with sorting and transferring. The Dibutyl phthalate and DEHP had been contained in all residual soil. Especially, resisual soil contained DEHP much more than peripheral soil. In J landfill residual soil, organic matter content, CEC and #200 sieve passing ratio is highest, and Freundlich isotherm sorption coefficient(K) and constant(1/n) is highest.

• 한국응용과학기술학회지
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• 제27권4호
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• pp.531-538
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• 2010

The electrochemistry characterization of metal is important in many industrial applications. In this study, we investigated the C-V diagrams related to the electrochemistry characterization of nickel. We determined electrochemical measurement by using cyclic voltammetry with a three electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rate were 100, 150, 200 and 200mV/s. As a result, the C-V characterization of nickel using ethanolamine and ethylethanolamine inhibitor appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding ethanolamine compound additive, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the effect of the electrochemistry characterization of nickel depends on ethanolamine structure interaction to adsorption complex.

• Applied Science and Convergence Technology
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• 제23권2호
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• pp.83-89
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• 2014

Adsorption of residual gas molecules damped the emission current of a W (310) field electron emission (FE) emitter. The damping speed was linearly proportional to the pressure gauge readings at pressure ranging from ${\sim}10^{-8}Pa$ to ${\sim}10^{-9}Pa$, and the proportionality constant was employed to measure pressure in the $10^{-10}Pa$ range. A time plot of FE current revealed the existence of an "initial stable region" after the flash heating of W(310) FE, during which the FE current damps very slowly. The presence of non-hydrogen gas removed this region from the plot, supplying a means of qualitatively analysing the gas species.

• 대한환경공학회지
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• 제35권7호
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• pp.472-478
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• 2013

기존 흡착제들보다 우수한 흡착성능을 확보하고, 특히 특정한 용제에 대한 흡착성능을 극대화하기 위하여 활성탄소섬유를 기본흡착제로 적용하였고, 여기에 활성금속을 첨착시켜 흡착성능과 선택성을 제고하고자 하였다. 선행 연구를 통하여 선정된 Cu, Cr을 기본 활성금속으로 하고 여기에 활성보조금속으로서 Pt, Pd를 복합 첨착시킨 활성탄소섬유를 첨착온도 및 시간을 변수로 하여 제조하였다. 복합첨착 활성탄소섬유의 흡착 성능이 단일첨착 활성탄소섬유와 비교하여 향상되었으며, 첨착온도 $100^{\circ}C$, 첨착시간 5시간 조건에서 최상의 흡착 성능을 확인할 수 있었다. Cu-Cr-Pt-Pd 복합첨착 활성탄소섬유가 가장 뛰어난 흡착성능을 보였으며, 기존 활성탄소섬유보다 2배 이상의 높은 흡착성능을 확인하였다. 한편, 활성금속첨착 활성탄소섬유상에의 확산 및 흡착에 필요한 최소 접촉시간은 0.5초 이상은 유지해야 함을 확인 할 수 있었다.