• Fibers and Polymers
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• 제5권1호
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• pp.52-58
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• 2004

Previous investigation results revealed that after the Low Temperature Plasma (LTP) treatment, the hydrophilicity of wool fiber was improved significantly. Such improvement enhances the wool dyeing and finishing processes which might be due to the changes of the wool surface to a more reactive one. In this paper, wool fibers were treated with LTP with different gases, namely, oxygen, nitrogen and gas mixture (25 % hydrogen/75 % nitrogen). Investigations showed that chemical composition of wool fiber surface varied differently with the different plasma gas used. The surface chemical composition of the different LTP-treated wool fibers was evaluated with different characterization methods, namely FTIR-ATR, XPS and saturated adsorption value. The experimental results were thoroughly discussed.

• 한국물환경학회지
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• 제22권4호
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• pp.626-631
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• 2006

The adsorption features of copper ion have been investigated by taking the barley residue which occurring from the beer production process as an adsorbent. Under the experimental conditions, adsorption equilibrium of copper ion was attained within 30 minutes after the adsorption started and the adsorption reaction was observed to be first order. As the temperature increased, the adsorbed amount of copper ion at equilibrium was also increased, which indicated that the adsorption reaction was endothermic. Based on the experimental results which obtained by varying the temperatures, several thermodynamic parameters for copper adsorption reaction were estimated. Regarding the electrokinetic behavior of barley residue, its electrokinetic potential was observed to be positive below pH 5 and turned into negative above this pH. In the pH range from 1.5 to 4, copper adsorption was found to be increased, which was well explained by the electrokinetic behavior of barley residue in the pH range. When nitrilotriacetic acid, which is a complexing agent, was coexisted with copper ion, equilibrium adsorption of copper ion was decreased and this was presumed to be due to the formation of metal complex. In addition, the adsorbed amount of copper ion was examined to be increased when $KNO_3$ was coexisted, however, it approached a saturated value above a certain concentration of $KNO_3$.

• 한국진공학회지
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• 제1권1호
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• pp.78-82
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• 1992

W(123) 표면위에 수소와 중소수가 흡착될 때 일함수의 변화를 장방출(Field Fmission) 방법으로 측정하였다. 78K에서 이 분자들이 흡착될 때 일함수의 변화는 처음에 는 증가하다가 최대치에 이른 후 감소하였고, 덮임율(coverage)이 증가함에 따라 포화되었 다. 텅스텐 tip의 온도를 200K까지 올렸을 경우에, 일함수의 변화가 최대가 되었을 때의 덮 임율은 78K일 때의 비해 낮은 덮임율 쪽으로 이동하였고, [011] 방향을 갖는 step 혹은 terrace에 의한 일함수의 효과도 동시에 관측되었다.

• 대한금속재료학회지
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• 제49권4호
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• pp.304-312
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• 2011

In this study, MOSFET type micro hydrogen gas sensors with platinum catalytic metal gates were designed, fabricated, and their electrical characteristics were analyzed. The devised MOSFET Hydrogen Sensors, called MHS-1 and -2, were designed with a platinum gate for hydrogen gas adsorption, and an additional sensing part for higher gas sensitivity and with a micro heater for operation temperature control. In the electrical characterization of the fabricated Pt-gate MOSFET (MHS-1), the saturated drain current was 3.07 mA at 3.0 V of gate voltage, which value in calculation was most similar to measurement data. The amount of threshold voltage shift and saturated drain current increase to variation of hydrogen gas concentration were calculated and the hydrogen gas sensing properties were anticipated and analyzed.

• Applied Biological Chemistry
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• 제34권2호
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• pp.125-129
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• 1991

상괴중(上壞中)에서 methyl 2-benzimidazole carbamate(MBC)의 흡착양상(吸着樣相)에 관(關)한 기초자과(基礎資科)를 얻고자 Kaolinite, Bentonite 및 Zeolite에 Na와 Mg를 포화(飽和)시키고 MBC를 첨가(添加)하여 습식(濕式)진(振)탕법(法)으로 흡착실험(吸着實驗)을 행(行)하였다. MBC점토광물(粘土鑛物)의 현탁류(懸濁流)에 있어서 Kaolinite는 2시간(時間), Bentonite와 Zeolite는 10시간(時間) 진탕 반응(反應)으로 각각(各各) 반응평형(反應平衡)에 도달(到達)하였다. MBC의 흡착량(吸着量)은 Zeolite>Bentonite>Kaolinite의 순(順)이었으며 포화(飽和)시킨 각(各) 이온의 종류간(種類間)에는 Mg보다 Na포화점토(飽和粘土)가 다소(多少) 컸다. MBC의 농도(濃度)가 높을수록 흡착량(吸着量)은 증가(增加)하였으며, 점토량(粘土量)이 많아질수록 MBC의 흡착량(吸着量)은 증가(增加)하였으나, Kd치(値)는 오히려 감소(減少)되었으며, Na-Zeolite가 가장 높은 Kd치(値)를 나타냈다. 각(各) 농도(濃度)에서 현탁류(懸濁流)의 pH가 낮을수록 MBC의 흡착량(吸着量)은 증가(增加)하였다. 따라서 점토광물(粘土鑛物)에 의(依)한 MBC흡착(吸着)은 상괴중(上壞中)에 존재(存在)하는 점토광물(粘土鑛物)의 종류(種類))와 함량(含量), ph 및 CEC등에 영향(影響)을 받을 것으로 사료(思料)된다.

• Corrosion Science and Technology
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• 제6권5호
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• pp.227-232
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• 2007

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in $Co_2$ environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCl. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but $Ac^-$ an hydrate easily to create HAc in carbon dioxide saturated environments. HAc is as catalyst in $Co_2$ corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased.

• 대한환경공학회지
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• 제39권1호
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• pp.19-25
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• 2017

본 연구에서는 도로환경에 적용 가능한 통기성 정전필터를 개발하여 흡착능을 평가하였다. 흡착특성은 ASHRAE 52.1, 52.2 등의 방법으로 입경별 제거율과 압력별 흡착량 등을 평가하였다. 평가 입경범위는 $0.3{\mu}m{\sim}10.0{\mu}m$로 12단계로 제거율을 평가하였다. 필터는 $2.5{\mu}m$ 이상에서 91.3%의 제거율을 보였으며 그 미만의 범위에서는 입경에 따라 감소하여 평균 53.5%의 제거율을 보였다. ASHRAE Dust 합성 분진에 의한 중량 제거율은 초기압력 22.6 mmaq에서 말기압력 35 mmaq까지 측정된 결과, 96.7%였으며 이때까지 흡착량은 $715.9g/m^2$ 이었다. 압력에 따른 흡착형태는 Langmuir 선도를 보였다. 말기압력까지 흡착된 필터를 물세정으로 1, 2차 재생한 후 흡착을 평가한 결과 제거효율에는 차이가 없었으나 초기압력과 흡착량은 약간의 저하가 발생하였다.