• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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• pp.133-138
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• 2001

In this study, quantitative nitric oxide concentration distributions are investigated in the laminar nonpremixed $H_2/N_2$ flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different $N_2$ dilution ratios varying from 20${\sim}$80%, and fuel now rate is fixed as lslpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. We applied same excitation line used in $CH_4$ premixed flame. Overall, NO concentration was rapidly decreased with $N_2$ addition and we could not measure the concentration any longer for $N_2$ dilution above 80%.

• 한국재료학회지
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• 제29권12호
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• pp.747-752
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• 2019

Environmental pollution remains a considerable health risk source all over the world; however, hazards are usually higher in developing countries. Iraq has long been suffering from the problem of pollution and how to treat pollution. Photocatalytic degradation has turned out to be most productive process for dye degradation. In this investigation, Rhodamine B (RhB), dye has been selected for degradation under visible light illumination. To address this issue, we fabricate erbium trioxide nanoparticles (Er₂O₃/NPs). Erbium trioxide nanoparticles are prepared and utilized for photo-catalytic degradation. The characterization of Er₂O₃/NPs is described and confirmed by utilizing of XRD (X-ray diffraction) and SEM (Scanning Electron Microscopy). The average size of Er₂O₃ nanoparticles is observed to be 16.00 nm. Er₂O₃/NPs is investigated for its ability of photo-catalytic degradation through certain selected parameters such as concentration and time. The methodological results show that the synthesized Er₂O₃/NPs is a good photo-catalytic for Rhodamine degradation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.156-161
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• 2000

In this study, quantitative nitric oxide concentration distributions are investigated in the post-flame zone of laminar premixed $CH_4/O_2/N_2$, flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different equivalence ratios varying from $0.8{\sim}1.4$, and flow rate is fixed as 5slpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interferences from Rayleigh scattering and $O_2$ fluorescence. NO concentration is rised when equivalence ratios increase at different vertical distances form nozzle tip. In any case, the maximum NO concentration reaches the maximum in reaction zone.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2283-2289
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• 2018

$TiO_2$ microspheres were successfully synthesised by simple solution phase method by using various amount of titanium butoxide as precursor. The prepared $TiO_2$ were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance absorption spectra (UV-DRS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XRD analysis revealed that the as-synthesized $TiO_2$ microsphere poses an anatase phase. The photocatalytic degradation experiments were carried out with three different dyes, such as methylene blue, brilliant black, reactive red-120 for four hours under UV light irradiation. The results show that $TiO_2$ morphology had great influence on photocatalytic degradation of organic dyes. The experimental results of dye mineralization indicated the concentration was reduced by a high portion of up to 99% within 4 hours. On the basis of various characterization of the photocatalysts, the reactions involved to explain the photocatalytic activity enhancement due to the concentration of titanium butoxide and morphology include a better separation of photogenerated charge carriers and improved oxygen reduction inducing a higher extent of degradation of aromatics.

• KSBB Journal
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• 제24권1호
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• pp.106-112
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• 2009

An optical sensing membrane has been fabricated to measure the concentration of dissolved oxygen(DO) and pH value simultaneously. It has employed HPTS as a pH sensitive dye and a ruthenium(II) complex as a DO sensitive dye. The sensing membrane has been applied to wells in a 24-well microtiter plate. Using the 24-well microtiter plate the concentrations of dissolved oxygen and pH values have been on-line monitored during the cultivations of E.coli DH5${\alpha}$, B.cereus 318 and P.pastoris X-33. On-line monitoring of DO and pH in microorganism cultivation processes showed good performance of the sensing membrane containing 5 mM HPTS and 2 or 5 mg/mL Rudpp.

• Elastomers and Composites
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• 제58권4호
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• pp.191-200
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• 2023

In this study, MoS₂ nanoparticles were synthesized and analyzed through powder X-ray diffraction, Raman, ultraviolet-visible, and X-ray photoelectron spectroscopies. The surface morphologies of the as-synthesized MoS₂ nanoparticles were investigated through scanning and transmission electron microscopies. The sonocatalytic activity of the MoS₂ nanoparticles toward Orange II removal was evaluated by utilizing a Box-Behnken design for response surface methodology in the experimental design. The sonocatalyst dosage, Orange II dye concentration, and ultrasound treatment time were optimized to be 0.49 g/L, 5 mg/L, and 150 min, respectively. The maximum efficiency of Orange II degradation on MoS₂ nanoparticles was achieved, with a final average value of 82.93%. Further, the results of a kinetics study on sonocatalytic Orange II degradation demonstrated that the process fits well with a pseudo-first-order kinetic model.

• 한국분무공학회지
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• 제7권4호
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• pp.42-49
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• 2002

In this study, quantitative measurement of nitric oxide concentration distributions were investigated in the laminar CH4/O2/N2 premixed flame by laser-induced fluorescence (LIF). The NO A-X (0,0) vibrational band around 226nm was excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interference from Rayleigh scattering and O2 fluorescence. The measurements were taken in CH4/O2/N2 premixed flame with equivalence ratios varying from $1.0{\sim}1.6$, and a fixed flowrate of 5slpm. NO was found to produce primarily between an inner premixed and an outer nonpremixed flame front, and total NO concentration is raised when equivalence ratios increase. These results suggest that prompt NO is likely to contribute to NO formation in CH4/O2/N2 premixed flame. Furthermore, this trend was well matched with previous works.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.437-447
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• 2018

Visible-light-driven wide bandgap semiconductor photocatalysts were commonly developed via doping or coupling with another narrow bandgap metal oxide. However, these approaches required extra processing. The aim of study was to evaluate the photocatalytic performance of narrow bandgap $WO_x$ nanoparticles. A mixture of $WO_2$ and $WO_3$ nanoparticles were synthesized using solution precipitation technique. The photodegradation of RhB by these nanoparticles more effective in UV light than in visible light. In antibacterial susceptibility assay, $WO_x$ nanoparticles demonstrated good antibacterial against Gram-positive bacteria. The cell wall of bacterial was the main determinant in antibacterial effect other than $W^{4+}/W^{6+}$ ions and ROS.

• 한국염색가공학회지
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• 제16권4호
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• pp.1-9
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• 2004

In recent, development of nano fiber has been one of the most active subjects in the world. Nano fiber is defined as a ultra fine yarn with a diameter unit of $10-100\times10^{-9}meter$, which is possible to be produced by an electro-spinning technology. In this study, physical characteristics and dyeing properties of nylon 66 nano fiber were investigated. Nylon 66 nano fiber was dyed with levelling type acid dyes. X-ray diffraction method and DSC analysis were used for the measurement of the degree of crystallization. Analysis of amino end groups was also performed in order to examine a relationship between number of amino groups and its dyeing property as well as water absorption behavior. The maximum exhaustion % of dyes and dyeing rate under various dyeing conditions, such as dyeing temperature and pH in dye bath, along with build-up properties for 2 acid dyes were evaluated. It was found that the degree of crystallization of nano fiber was smaller than that of regular fiber, and amino end groups of nano fiber were less than regular fiber. Half dyeing time of nano fiber was shorter than regular fiber because of the bigger specific surface area. Effect of pH on exhaustion % was small in case of nano fiber. Exhaustion of nano fiber increased with higher concentration of dye.

• 한국수소및신에너지학회논문집
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• 제13권4호
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• pp.279-286
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• 2002

In this study, quantitative nitric oxide concentration distributions are investigated in the laminar non-premixed $H_2/N_2$ flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different $N_2$ dilution ratios varying from 20~80%, and fuel flow rate is fixed as Islpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. We applied same excitation line used in $CH_4$, premixed flame. Overall, NO concentration was rapidly decreased with Na addition and we could not measure the concentration any longer for $N_2$ dilution above 80%.