• 제목/요약/키워드: Acid/base treatment

검색결과 197건 처리시간 0.023초

Study on the characteristics of the organic thin-film transistors according to the gate electrode surface treatments

  • Kim, Hye-Min;Park, Jae-Hoon;Bong, Kang-Wook;Kang, Jong-Mook;Lee, Hyun-Jung;Han, Chang-Wook;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1292-1294
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    • 2007
  • In this report, the effects of chemical surface treatments of ITO gate electrodes of OTFTs have been studied by using acid and base solutions. As a result, it is observed that the threshold voltage of OTFTs could be influenced and modified by the surface treatments. The device with an ITO gate electrode surface-treated by a base solution shows the lowest threshold voltage of -7.66 V, while the threshold voltages are about -13.51 V and -15.3 V for the devices without a surface treatment and with the acid solution treatment, respectively. It is thought that the work function of ITO electrode surface might be affected by the surface treatments, thereby influencing the threshold voltage.

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알루미늄 기판의 무전해 니켈-구리-인 합금도금에 관한 연구(I) 전해액 및 열처리 조건이 무전해 니켈-구리-인 도금층의 제 물성에 미치는 영향 (A Study on the Electroless Ni-Cu-P Alloy Plating of Al Base Hard Disk(I)Effect on some Properties of Electroless Ni-Cu-P Deposits by Electrolyte and Heat Treatment Condition)

  • 오이식;황용길
    • 한국표면공학회지
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    • 제24권2호
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    • pp.103-113
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    • 1991
  • Electroless Ni-Cu-P alloy plating of Al base hard disk was performed to investigate some properties according to the change of composition. It was found that the composition of Ni and Cu in deposits changed linearly with increasing the mole ratio of NiSO4.6H2O/CuSO4.5H2O. The increase in hardness by heat - treatment was confirmed to be associated with small size grained crystallization of the amorphous deposits. Acid resistance of all deposits layer. which had been heated up to 30$0^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, and it showed more superior acid resistance with decreasing Cu content and with increasing P. The resistivity of the deposits heat treated became smaller at temperature more than 50$0^{\circ}C$, and it became largerly with increasing P content. Cu 44.1wt% alloy(C bath) showed the most superior non-magnetically stable characteristics after heat treatment. It was superiorly with higher temperature and with decreasing P content.

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Engine 폐유 자원순환 기술에 관한 연구 (A study for cyclic Process technique of mineral base engine used oil resource)

  • 김주항
    • 기술사
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    • 제18권2호
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    • pp.6-15
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    • 1985
  • A new process disregraded the H$_2$SO$_4$ treatment process heretofore in use, was developed and substituted for mineral base engine used oil of homemade SAE-30 grade H.V.I., which was used covering 4,500km, as samples, and the following results in research, was obtained. (1) A good quality of rerefinded base oil was obtained through roughly a course of developed processes of vacuum distillation process, solvent extraction process, neutralization treatment process and clay treatment process. (2) Through vacuum distillation process, the size of fine grains of insoluble colloid carbon that is, colloid carbon which was produced by burning of internal combustion engine oil and fuel, could be brought up and precipitated (3) The insoluble matters and admixtures could be easily dispersed and dissolved by mixing and extracting solvent disregarded the H$_2$SO$_4$ treatment process heretofore in use (4) waste matter heretofore called acid sludge in consequence of the process, did not appear at all. accordingly, the environmental pollution could be removed. (5) The troubles of corrosion to copper strip which was faults of the usual used oil refined products and peculiar offensive odor of the rerefined oil, could be solved through the neutralization process. (6) The yield of rerefined oil obtained through a course of processes was over 86 percent, and it is of practical use, not to speak of commercial value.

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자외선(紫外線) 조사(照射)에 의한 노랑느타리버섯 담자포자(擔子胞子)의 영양요구성(營養要求性) 균주(菌株) 선발(選拔)에 관한 연구(硏究) (Isolation of Auxotrophic Mutants from Basidiospores of Pleurotus cornucopiae)

  • 이연희;박용환;유영복;민경희
    • 한국균학회지
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    • 제14권2호
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    • pp.185-188
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    • 1986
  • 노랑 느타리버섯의 유전 연구 및 다른 느타리종과의 융합을 위해서 노랑 느타리의 담자포자에 자외선을 조사하여 영양요구성 균주를 선발하였다. 노랑 느타리 포자에 UV를 조사한 결과 UV조사시간이 $40{\sim}70$초이고 생존율 $0.4{\sim}1.4%$ 일때 많은 mutants를 얻을 수 있었고, 선발된 14 auxotrophic mutants의 유전 marker는 amino acid-requiring strain 3균주, nucleic acid base-requiring strain 1 균주, vitamin-requiring strain 3 균주, amino acid/nucleic acid base-requiring strain 2 균주, amino acid/vitamin-requiring strain 5 균주로 되었다.

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Ni 산성염과 Ni 염기성 염의 혼합에 의한 나노 NiO 분말 제조 및 이의 환원 특성 (Preparation of nanosized NiO powders by mixing acid and base nickel salts and their reduction behavior)

  • 김창삼;윤동훈;전성운;권혁보;박상환
    • 한국결정성장학회지
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    • 제20권6호
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    • pp.283-288
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    • 2010
  • 나노 크기의 NiO 분말을 Ni 산성염과 Ni 염기성염을 혼합하여 제조하는 방법에서 원료가 생성되는 NiO와 이의 환원으로 생성되는 Ni 결정 특성에 미치는 영향을 연구하였다. 산성염으로는 Ni formate를 염기성염으로는 수산화 Ni과 염기성 Ni 탄산염을 사용하였다. 혼합비는 산성염 1당량에 염기성염 9당량을 사용하였으며, 탄산염을 사용한 경우 $750^{\circ}C$/2 h 하소에서도 ~100 nm의 구형의 NiO 분말을 얻었으며, 수산화 염을 사용한 경우는 $600^{\circ}C$/2 h에서는 ~100 nm의 유사 구형의 NiO가 생성되나, $750^{\circ}C$ 열처리에서는 100~600 nm의 유사 입방체 분말을 얻었다. 수산화 염을 사용한 경우에는 탄산염을 사용한 경우에 비하여 수소가스에 의한 환원이 훨씬 빠르게 진행되어 necking이 일어나며 소결이 이루어져 다공체를 형성하였다. 이들 특성을 TG/DSC, XRD, SEM으로 분석하였다.

실리카의 표면 처리와 교반 속도가 폴리카프로락톤 마이크로캡슐의 향유 방출 거동에 미치는 영향 (Influence of Surface Treatment of SiO$_2$ and Stirring Rate on Fragrant Oil Release Behavior of Poly($\varepsilon$-caprolactone) Microcapsules)

  • 박수진;양영준;이재락;서동학
    • 폴리머
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    • 제27권5호
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    • pp.464-469
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    • 2003
  • 실리카의 표면 처리가 마이크로캡슐의 향유 방출 거동에 미치는 영향에 대하여 고찰해 보았다. 표면 산-염기 처리 용액으로서 30 wt%, 20 wt% 그리고 10 wt%의 HCl과 NaOH 용액을 사용하였다. 실리카의 표면 산도 및 표면 염기도를 Boehm의 선택 중화법을 이용하여 측정하였으며 그 흡착 표면적과 총 기공부피는 BET법을 이용한 $N_2$ 기체의 흡착을 통해 알아보았다 액중건조법을 사용하여 향유가 흡착된 실리카를 심물질로 하는 PCL 마이크로캡슐을 제조하였으며, 다공성의 실리카에 향유를 흡착시키기 위하여 초음파를 이용하였다. 제조된 마이크로캡슐의 입도는 광학 현미경을 이용하여 관찰하였으며 FT-IR측정을 통하여 심물질이 함입되었음을 확인하였다. 또한 마이크로캡슐의 향유 방출 거동을 살펴보기 위해 UV/vis. 흡광광도법으로 흡광도를 측정하여 용출된 향유의 양을 정량하였다. 실험 결과, 교반 속도가 증가함에 따라 평균입자 크기가 35 $\mu$m에서 21 $\mu$m로 감소하였으며, 실리카의 산처리를 통해 비표면적이 78.1에서 121.1 m$^2$/g으로 증가함에 따라 향유의 흡착량이 약 20% 증가하고 염기처리를 통해 실리카의 염기도가 78에서 134 meq./g으로 증가하여 향유와 실리카의 산-염기 상호작용의 증가로 인해 향유의 시간에 따른 방출 속도가 감소함을 알 수 있었다.

Modeling the electric transport of HCl and H3PO4 mixture through anion-exchange membranes

  • Koter, Stanislaw;Kultys, Monika;Gilewicz-Lukasik, Barbara
    • Membrane and Water Treatment
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    • 제2권3호
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    • pp.187-205
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    • 2011
  • The electric transport of the mixture of hydrochloric and phosphoric acids through strong base (Neosepta ACM) and weak base (Selemion AAV) anion-exchange membranes was investigated. The instantaneous efficiency of HCl removal from the cathode solution, $CE_{Cl}$, with and without $H_3PO_4$ was determined. It was found that $CE_{Cl}$ was 0.8-0.9 if the number of moles of elementary charge passed through the system, $n_F$, did not exceed ca. 80% of the initial number of HCl moles in the cathode solution, $n_{Cl,ca,0}$. The retention efficiency of $H_3PO_4$ in that range was close to one. The transport of acid mixtures was satisfactorily described by a model based on the extended Nernst-Planck and Donnan equations for $n_F$ not exceeding $n_{Cl,ca,0}$. Among the tested model parameters, most important were: concentration of fixed charges, the porosity-tortuosity coefficient, and the partition coefficient of an undissociated form of $H_3PO_4$. For the both membranes, the obtained optimal values of fixed charge concentration, $\bar{c}_m$, were up to 40% lower than the literature values of $\bar{c}_m$ obtained from the equilibrium measurements. Regarding the $H_3PO_4$ equilibria, it was sufficient to consider $H_3PO_4$ as a monoprotic acid.

Effect of coagulation conditions on ultrafiltration for wastewater effluent

  • Maeng, Sung Kyu;Timmes, Thomas C.;Kim, Hyun-Chul
    • Membrane and Water Treatment
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    • 제8권2호
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    • pp.185-199
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    • 2017
  • Low-pressure membrane filtration is increasingly used for tertiary treatment of wastewater effluent organic matter (EfOM), mainly comprising organic base/neutral compounds. In-line coagulation with underdosing, charge neutralization, and sweep floc conditions prior to ultrafiltration (UF) was studied to determine removals of the EfOM components and consequent reduction of fouling using polyethersulfone membranes. Coagulation and UF substantially reduced fouling for all coagulation conditions while removing from 7 to 38% of EfOM organic acids. From 7 to 16% of EfOM organic base/neutrals were removed at neutral pH but there was no significant removal for slightly acid coagulation conditions even though fouling was substantially reduced. Sweep floc produced the lowest resistance to filtration but may be inappropriate for in-line use due to the large added volume of solids. Charge-neutralization resulted in poor recovery of the initial flux with hydraulic cleaning. Under-dosing paralleled sweep floc in reducing hydraulic resistance to filtration (for sub-critical flux) and the initial flux was also easily recovered with hydraulic cleaning. Hydrophobic and hydrophilic base/neutrals were identified on the fouled membranes but as previously reported the extent of fouling was not correlated with accumulation of organic base/neutrals.

Nonlinear self-tuning regulator for neutralization of weak acid streams by a strong base

  • Lee, Sang-Deuk;Lee, Ji-Tae;Park, Sun-Won
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.786-789
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    • 1989
  • A nonlinear self-tuning regulator for a neutralization process of a weak acid and strong base system is proposed. Rearranging the state equation of the process model, we first obtain equations which are linear for a manipulated variable or unknown parameters. Then to these equations we apply the standard procedure used in designing linear self-tuning regulators. Simulation results show that the regulator provides very good performances for various realistic situations and traces variations of the unknown parameters. Since computations are simple and additional measurements except the effluent pH value are only flow rates of influent streams, it can be easily applied to real processes such as a waste water treatment process.

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Adsorption Behaviors of Noxious Gases on Chemically Surface-treated Activated Carbons

  • Park, Soo-Jin;Shin, Jun-Sik
    • Carbon letters
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    • 제4권1호
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    • pp.31-35
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    • 2003
  • The specific adsorption behaviors of activated carbons (ACs) treated with 30 wt% $H_3PO_4$ or NaOH were investigated in the removals of NO or $NH_3$. The acid and base values were determined by Boehm's titration method. And, the surface properties of ACs were studied by FT-IR and XPS analyses. Also, $N_2/77K$ adsorption isotherm characteristics, including the specific surface area and micropore volume were studied by BET and t-plot methods, respectively. From the adsorption tests of NO and $NH_3$, it was revealed in the case of acidic treatment on ACs that the $NH_3$ removal was more effective due to the increase of acidic functional groups in carbon surfaces. Also, the NO removal was increased, in the case of basic treatment, due to the improvement of basic functional groups, in spite of significant decreases of BET's specific surface area and total pore volume. It was found that the adsorption capacity of ACs was not only determined by the textural characteristics but also correlated with the surface functional groups in the acid-base intermolecular interactions.

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