• 콘크리트학회논문집
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• 제21권6호
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• pp.729-735
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• 2009

이 연구에서는 산업부산물을 재활용하는 차원에서 화학비료공장의 인산제조과정 중 부산물로 발생되는 인산부산석고($CaSO_4/H_2O$)를 이수석고 형태인 건조석고, 반수석고, III형 무수석고, II형 무수석고로 실험용시료를 제조하여 화학분석을 통해 그 석고의 품질특성을 분석하고 조건별로 제조된 석고를 각각 3.0%씩 고로슬래그 시멘트에 첨가하여 시멘트 품질에 미치는 영향을 연구하였다. 그 결과 석고의 제조 조건에서 온도가 높아질수록 석고의 품질이 향상되는 결과가 확인 되었으며 $700^{\circ}C$ 소성조건인 II형 무수석고에서 시멘트 품질에 영향을 미칠 수 있는 수용성인산($S-P_2O_5$)이 현저히 낮아지는 경향이 나타났다. 또한 고로슬래그 시멘트 적용 실험 결과 II형 무수석고에서 재령 3일 압축강도와 건조수축 길이변화가 양호한 것으로 나타났고 재령 56일에서 압축강도는 반수석고, III형 무수석고, 건조석고, II형 무수석고 순으로 높게 나타나는 경향을 보였다.

• 대한환경공학회지
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• 제27권2호
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• pp.163-169
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• 2005

본 연구에서는 인공 UV lamp의 대체에너지로 무한한 청정에너지인 태양광을 광원으로 이용하여 Cu(II)-EDTA 제거를 위한 광촉매 산화반응을 실시하였다. Cu(II)-EDTA의 광촉매 산화반응의 효율에 관한 연구를 위해 집광반사판의 형태, 집광반사판의 입사각, 광세기, 유량, 반응면적, $H_2O_2$의 효율, 그리고 광촉매 형태의 변화에 따라 실시하였다. Cu(II)와 DOC 제거율은 평판형의 집광반사판보다 반구형의 집광반사판 사용시 높게 나타났으며, 반사판의 각도를 $38^{\circ}$까지 증가시킬수록 제거속도 및 제거율이 각각 증가였다. $TiO_2$ 분말시스템은 $TiO_2$ 코팅 시스템보다 Cu(II)와 DOC 제거율에 있어서 약 4배 이상의 큰 제거율을 나타내어서 제거효율에 있어서는 우수한 것으로 조사되었다. Cu(II)와 DOC 모두 자외선 세기가 높은 맑은 날($0.372{\sim}2.265\;mW/cm^2$)에 제거효율이 가장 좋은 것으로 나타났는데, Cu(II)의 경우 흐린날($0.038{\sim}1.129\;mW/cm^2$에 비하여 약 3배, DOC의 경우 약 2배의 높은 제거율이 나타나서 광세기가 양자수율에 직접적으로 영향을 미침을 알 수 있었다. Cu(II)가 제거되는 경향은 반응기의 면적이 클수록 증가하였으며, 유량변동에는 비슷한 경향을 보였지만 일정유량 이상에서는 방해요인이 되는 것으로 나타났다. 코팅된 $TiO_2$를 광촉매로 사용하였을 때 $H_2O_2$ 농도증가에 따라 Cu(II)의 제거효율은 크게 증가하였지만 분말형 $TiO_2$ 사용시에는 이에 비해 $H_2O_2$ 주입효과가 크게 나타나지 않았다.

• 수산해양기술연구
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• 제50권3호
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• pp.318-325
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• 2014

The main object of this study is to investigate the collection characteristics of wet-type rotating porous disk system experimentally. The experiment is carried out to analyze the pressure drop and collection efficiency for the present system with the experimental parameters such as system inlet velocity, stage number, tube diameter, inlet concentration, etc. In results, for the present system, at 5 stage and ${\upsilon}_{in}=1.8m/s$, the pressure drop becomes significantly lower as $64mmH_2O$ in comparison with that of the conventional wet type scrubber (Venturi scrubber, over $250mmH_2O$). The collection efficiencies increase with higher inlet velocity showing 92, 95.7, 98.4%, while $SO_2$ removal efficiencies decrease with increment of inlet velocity as 80, 65, 50% at ${\upsilon}_{in}=1.08$, 1.44, 1.8 m/s and tube diameter $D_t=10mm$, respectively. The present system is to be considered as an effective compact system for a simultaneous removal of particle/gas phase pollutants from marine diesel engines.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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• pp.142-145
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• 1993

$TiO_2-V_2O_5$ thin films are fabricated by Sol-Gel method and humidity sensing properties have been investigated. As the results of humidity sensing properties of thin films fabricated as humidity sensor, it is confirmed to have good humidity sensing properties in high humidity and low frequency regions.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.679-682
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• 2002

Layered Na0.7[Ni0.05Mn0.95]O2 compounds have been synthesized by a sol-gel method, using glycolic acid as a chelating agent. Na0.7[Ni0.05Mn0.95]O2 precursors w ere used to prepare layered lithium manganese oxides by ion exchange for Na by Li, using LiBr in hexanol. Powder X-ray diffraction shows the layered Na0.7[Ni0.05Mn0.95]O2 has an O3 type structure, which exhibits a large reversible capacity of approximately 190 mA h g-1 in the 2.4-4.5 V range. Na0.7[Ni0.05Mn0.95]O2 powders undergo transformation to spinel during cycling.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1162-1164
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• 1995

In this paper, $TiO_2$-xmol%$V_2O_5$, x=0.0, 1.0, 2.0, 3.0 specimens are fabricated by Sol-Gel method. For the improvement of humidity sensitive characteristics for specimens, their microstructures are analysed and the optimum processing condition is established. Grain size increases with substitution rate of $V^{5+}$, on $Ti^{4+}$ site. Their humidity sensitive characteristics is good at 1mol% of $V_2O_5$ rate and heat-treated at $700^{\circ}C$. The capacitance of specimens decreases with frequency.

• 웰빙융합연구
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• 제7권3호
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• pp.67-72
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• 2024

This study developed a dry composite module-type deodorization facility with Twisting airflow changes and two forms (catalyst, adsorbent) within one module. Experiments were conducted to evaluate the reduction efficiency of odor substances C₈H₇N and C₉H₉N. The device combines UV oxidation using TiO₂, catalytic oxidation using MnO₂, and adsorption using A/C in five different methods. Data analysis of experimental results utilized the statistical package program Python 3.12. The program applied frequency analysis of odor removal efficiency, one-way ANOVA, and post-hoc tests, with statistical significance determined by p-value to ensure reliability and validity of the measurements. Results indicated that the highest removal efficiency of C₈H₇N and C₉H₉N was achieved by the UV+A/C method, suggesting the superior effectiveness and efficiency of the developed device. Combining multiple processes and technologies within one module enhanced odor treatment efficiency compared to using a single method. The device's modularity allows for flexibility in adapting to various sewage treatment scenarios, offering easy maintenance and cost-effective deodorization. This composite reaction module device can apply multiple technologies, such as biofilters, plasma, activated carbon filters, UV-photocatalysis, and electromagnetic-chemical systems. However, this study focused on UV-photocatalysis, catalysts, and activated carbon filters. Ultimately, the research demonstrates the practical applicability of this innovative device in real sewage treatment operations, showing excellent reduction efficiency and effectiveness by integrating UV oxidation, TiO₂ photocatalysis, MnO₂ catalytic oxidation, and A/C adsorption within a modular system.

• 한국수소및신에너지학회논문집
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• 제18권4호
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• pp.452-457
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• 2007

Titanium foil and mesh(anodized tubular $TiO_2$ electrode, ATTE) were anodized in a bath at $5^{\circ}C$ with 20V external bias applied, then annealed at different temperatures($450^{\circ}C{\sim}850^{\circ}C$) to obtain tubular $TiO_2$ on the Ti substrate. The prepared sample was used to investigate rate of hydrogen production as well as Cr(VI) reduction. The ATTEs annealed at relatively lower temperatures showed higher activity than those at relatively higher temperatures. In particular, the Cr(VI) reduction was pH-dependent. To improve photocatalytic Cr(VI) reduction with the ATTEs, two configurations, fixing foil type and rotating mesh type, were also compared. As a result, the rotating mesh type was much more effective for Cr(VI) reaction than the former due to the more efficient use of the light. In the rotating type reactor, as the rotating speed increased, the rate of the Cr(VI) reduction was getting faster.

• 한국재료학회지
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• 제18권2호
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• pp.84-91
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• 2008

The effects of the deposition and annealing temperature on the structural, electrical and optical properties of Ag doped ZnO (ZnO : Ag) thin films were investigated. All of the films were deposited with a 2wt% $Ag_2O-doped$ ZnO target using an e-beam evaporator. The substrate temperature varied from room temperature (RT) to $250^{\circ}C$. An undoped ZnO thin film was also fabricated at $150^{\circ}C$ as a reference. The as-grown films were annealed in temperatures ranging from 350 to $650^{\circ}C$ for 5 h in air. The Ag content in the film decreased as the deposition and the post-annealing temperature increased due to the evaporation of the Ag in the film. During the annealing process, grain growth occurred, as confirmed from XRD and SEM results. The as-grown film deposited at RT showed n-type conduction; however, the films deposited at higher temperatures showed p-type conduction. The films fabricated at $150^{\circ}C$ revealed the highest hole concentration of $3.98{\times}1019\;cm^{-3}$ and a resistivity of $0.347\;{\Omega}{\cdot}cm$. The RT PL spectra of the as-grown ZnO : Ag films exhibited very weak emission intensity compared to undoped ZnO; moreover, the emission intensities became stronger as the annealing temperature increased with two main emission bands of near band-edge UV and defect-related green luminescence exhibited. The film deposited at $150^{\circ}C$ and annealed at $350^{\circ}C$ exhibited the lowest value of $I_{vis}/I_{uv}$ of 0.05.

• 한국식품영양학회지
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• 제22권1호
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• pp.103-109
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• 2009

현재까지 미생물에 의해 생산되는 10,000여 종의 항생물질 가운데 약 2/3 에 해당하는 64% 정도가 방선균으로부터 발견되었다. 따라서 토양 중에 널리 분포하고 있는 방선균을 분리하여 광범위 항생물질 생산능이 가강 우수한 Y-88을 최종 선정하였다. 이 균을 형태학적, 생리상 및 배양학적으로 동정한 결과 Streptomyces 속으로 밝혀져 Streptomyces sp. Y-88 이라 명명하였다. Y-88로부터 항생물질 생산 최적 배양조건을 검토한 결과 soluble starch 1.6%, glucose 1.6%, beef extract 0.6%, $K_2HPO_4$, $MgSO_4$ $7H_2O$ 및 $ZnSO_4$ $7H_2O$가 각각 0.01%였으며, 최적 pH4.0, 배양온도 25$^{\circ}C$ 그리고 배양시간으로 위의 조건에 30시간에서 항생물질 생산이 빠른 것으로 나타났다.