• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.823-830
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• 2008

The feasibility study for the application of the photoelectrocatalytic decolorization of Rhodamine B(RhB) was performed in the slurry photoelectrochemical reactor with powder TiO$_2$. The photoelectrocatalytic process was consisted of powder TiO$_2$, Pt electrode and three 8 W UV-C lamps. The effects of operating conditions, such as current, electrolyte, air flow rate and electrode material were evaluated. The experimental results showed that optimum TiO$_2$ dosage and current in photoelectrocatalytic process were 0.4 g/L and 0.02 A, respectively. It was found that the RhB could be degraded more efficiently by this photoelectrocatalytic process than the sum of the two individual oxidation processes(photocatalytic and electrolytic process). It demonstrated a synergetic effect between the photo- and electrochemical catalysis. Photoelectrocatalytic process was affected to air flow rate and optimum air flow rate was 2 L/min. The electrode material and NaCl effect of decolorization of RhB were not significant within the experiment conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.119-122
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• 2006

Process variables for manufacturing the $CuInSe_2$ thin film were established in order to clarify optimum conditions for growth of the thin film depending upon process conditions (substrate temperature, sputtering pressure, DC/RF Power), and then by changing a number of vapor deposition conditions and Annealing conditions variously, structural and electrical characteristics were measured. Thereby, optimum process variables were derived. For the manufacture of the $CuInSe_2$, Cu, In and Se were vapor-deposited in the named order. Among them, Cu and In were vapor-deposited by using the sputtering method in consideration of their adhesive force to the substrate, and the DC/RF power was controlled so that the composition of Cu and In might be 1:1, while the surface temperature having an effect on the quality of the thin film was changed from 100[$^{\circ}C$] to 300[$^{\circ}C$] at intervals of 50[$^{\circ}C$].

• Journal of Adhesion and Interface
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• v.7 no.3
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• pp.16-25
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• 2006

Water vapour permeable and water resistant film was laminated to made footwear woven fabric and non-woven fabrics by screen type with thermosetting reactive hot melt adhesive. Optimum conditions of each process were investigated, and the properties of film laminated fabric with optimum conditions are evaluated. The results are as follows. Thermosetting reactive polyurethane hot melt is retain proper heat resistance differently thermoplastic hot melt. Optimum melting adhesive process conditions are as follows ; drum temperature $95^{\circ}C$, hose temperature $97^{\circ}C$, feeding pipe temperature $100^{\circ}C$, screen temperature $105^{\circ}C$, pressure of opposite roller $1kgf/cm^2$, pressure of laminating roller $3kgf/cm^2$, finishing speed 15 m/min, melting temperature $120^{\circ}C$, cooling time 20 s, pressing temperature $130^{\circ}C$, pressing time 30 s. As the thickness of film was increased, the water vapour permeability was decreased but water resistance was increased, and the effect of film is dominant over all the others in the air permeability.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.303-309
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• 1988

In order to establish the process of interspecific protoplast fusion of the genus Cellulomonas capable of utilizing of cellulose, C. flavigena NCIB 12901 and Cellulomonas sp. CSI-1, the optimum conditions for the regeneration and fusion were examined. The condition of suitable osmotic stabilizer for the protoplast regeneration of C. flavigena was established by using 0.4M sorbitol. And then, by addition of 3% po]yvinyl pyrrolidone (PVP) to cell wall regeneration medium, regeneration frequency was increased 3 times higher than that without PVP addition. The optimum conditions for the interspecific protoplast fusion between auxotrophic and antibiotics resistant mutants were obtained with 40%(W/V) of PEG (polyethylene glycol) 6000 as the fusogenic agent and 25mM of CaCl$_2$on treating time for 15 min. The fusion frequency between mutants was from 2.0$\times$10$^{-4}$ to 4.0$\times$10$^{-4}$ under the optimum conditions. The fusants were confirmed to revert from protoplast to cells of rod type during regeneration process and the aggregation of protoplast by PEG was observed. Also the progress of fusion was observed by scanning electron microscopy, Many isolated fusants were shown to be complement clones of both parents which occured at a high frequency among the isolated clones.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.257-263
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• 2012

The selection of suitable delignification conditions and optimization of process variables is crucial to the successful operation of chemical pulping processes. Soda pulping of Carpolobia lutea was investigated, as an alternative raw material for pulp and paper production. The process was optimized under the influence of three operational variables, namely, temperature, time and concentration of cooking liquor. Equations derived using a second - order polynomial design predicted the pulp yield and lignin dissolution with errors less than 8% and 11% respectively. The maximum variations in the pulp yield using a second order factorial design was caused by changes in both time and alkali concentration. Optimum pulp yield of 43.87% was obtained at low values of the process variables. The selectivity of lignin dissolution was independent of the working conditions, allowing quantitative estimations to be established between the pulp yield and residual lignin content within the range studied.

• Journal of Welding and Joining
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• v.16 no.6
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• pp.97-103
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• 1998

The bracket tilt among automobile parts is weld parts which construct the column assembly bracket tilt of equipments and accurate dimension after welding is more essential than weldment strength. By the way, it is insufficient that systematic study about this parts which have an importance on welding deformation. The reason is that welding deformation is complex problem with shape, size, material of parts and welding sequence, conditions etc. For reduction and removal of welding deformation, therefore, it is necessary that the security of welding deformation data and systematic examination about equipment, costs, work environment, manufacturing process etc. It is all the better that the prediction of welding deformation using simulation of welding process by FEA is supplemented. In this study, the countermeasure for this welding deformation of bracket tilt is brought up through experimental inspection before the choice of the optimum welding conditions with minimum welding deformation by simulation of welding process.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.10
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• pp.1535-1544
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• 1989

The overhang structure of photoresist in optical lithography was studied for the metallization of GaAs-related devices throughout lift-off method. Optical contact aligner with a dose of 8.5 m J/cm\ulcornerand with a wavelength of 300mm was used for ultraviolet exposure of single layer of S1400-27 photoresist. The overhang thickness shows a linear relationship with the soaking time in monochlorobenzene, which its magnitude becomes high at elevated softbake temperature. Such process conditions as a low softbake temperature, a long monochlorohbenzene soaking time and a little exposed energy make the development rate of photoresist lower. The optimum process conditions to obtain a target line-width, which include an appropriate overhang structure such as complete separation between the sidewall of photoresist pattern and the deposited metal edge, are determined as the softbake temperature of 64-74\ulcornerC, the monochlorobenzene soaking time of 10-15min, the ultraviolet exposure time of 70-100sec and the development time of 50-80sec.

• Journal of Welding and Joining
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• v.5 no.4
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• pp.28-35
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• 1987

The feasibility of underwater wet arc welding process is experimentally investigated by using high titanium oxide type electrodes and TMCP steel plates as base metal. It is assertained the tis process may be put to practical use. Main results are summarized as follows; (1) Sound underwater weld can be obtained by skilled welding operator, if proper welding conditions are selected. (2) In underwater wet arc welding process, the mechanical properties of HAZ are depend upon welding condition and the optimum welding condition can obtained. (3) The maximum hardness in the HAZ of TMCP steel plates is increased significantly in this welding process.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.509-516
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• 1995

The treatment performances of anaerobic-aerobic activated sludge process were investigated under various operation conditions. The treatment system proposed in this study gave a relatively stable performance against hourly change of the flow rate and showed a satisfactory removal of nitrogen and phosphorus compounds under experimental conditions. The recycle ratio of mixed liquor from aerobic to anaerobic region and peak coefficient primarily controlled the extent of nitrogen removal. The recycle ratio had the optimum values which were determined by the microbial activities of nitrification and denitrification. The behavior of the treatment unit could be simulated by using the kinetic equations and reactor models which considered the treatment units as complete mixing tanks.