• KSBB Journal
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• v.10 no.4
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• pp.401-405
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• 1995

An open pond type photobioreactor for mass cultivation of S. platensis was designed and the growth parameters from different cultivation processes were compared. 0.30(1/day) of specific growth rate and 1.69(g/$\ell$) of maximum cell density were obtained from batch cultivation. In fed-batch cultivation, specific growth rate and maximum cell density were estimated as 0.22(1/day) and 1.75(g/$\ell$), respectively. Maximum biomass productively from continuous cultivation was obtained as 0.44 (g/$\ell$/day). It proves that an outdoors-mass cultivation of S. platensis considering optimal environmental condition is economically feasible. In addition, the biomass productivity was studied in two different mixing systems such as agitation and air sparging methods. The biomass productivity by an agitation method was better than that in an air sparging method.

• Journal of the Korea Institute of Building Construction
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• v.9 no.2
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• pp.77-83
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• 2009

In this study, a test has been carried out to solve the problem with ground granulated blast-furnace slag, low early strength & lack of supply and to find out a way to use as concrete admixture of the ultrafine blaine air cooling slag which is all disposed as the by product of air cooling slag and its test was conducted to the replacement rate of ultrafine blaine air cooling slag & mixing condition of every concrete admixtures by type for the purpose of obtaining later a basic data for practical use of the cement that used ultrafine blaine air cooling slag by conducting comparative analysis. If ultrafine-blaine air cooling slag is used to the concrete following the results, a high efficiency water reducing agent won't be needed much for flow acquisition due to a high increase in flow, and the stripping time of concrete form will be shortened thanks to the acquisition of early strength, And though, it has the problems with long term strength which is similar or a little lower than the 3 types of ground granulated blast-furnace slag, it's still applicable as the substitute materials for 3 types of ground granulated blast-furnace slag at 10, 15% replacement rate of ultrafine-blaine air cooling slag, at which it shows higher activation index than 3 types of ground granulated blast-furnace slag.

• Fashion & Textile Research Journal
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• v.15 no.5
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• pp.808-814
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• 2013

In this study, The mixture of three kinds of pre-treatment agents, Carboxymethyl cellulose sodium salt(CMC), Sodium alginate and Dextrin, have been prepared for the better coloration of digital textile printing. To get sharpness of outline during digital printing process, the optimal formulation is the CMC and Sodium alginate mixture 1:1 ratio by volume. Cyan, Yellow, and Black colours are excellent on the Sodium alginate mixtures. But, Magenta is excellent in the CMC and Dextrin mixture. Sharpness and printability are closely related to viscosity of the mixture. The most optimal sharpness of outline achieved with a consideration of coloring, and field operations account for production when the viscosity of the mixed pre-treatment agent approximately is 10~13 cSt. Change in shade and staining of wash fastness for all the treated samples with the mixtures rated 4-5 grade. Both dry rubbing fastness to shade change and staining are good in the treated samples, whereas wet rubbing fastness rated 2-3 grade. To improve wet rubbing fastness, the Sodium alginate and Dextrine mixture, which rated 3-4 grade for Black color, is applicable. With exception of 3 rating to black color, Light fastness is 4 rating for the remaining three colors in the regardless of treatment condition and mixing of the pre-treatment agent. Dry cleaning fastness of all samples are also 4-5 rating.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.1
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• pp.24-33
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• 2020

In this study, model combustion tests were conducted to investigate the combustion instability characteristics of swirl coaxial injectors for a liquid rocket engine. To examine the effects of the combustion chamber resonant frequency and the injector mixing conditions, pressure fluctuations in the combustion chamber were measured by changing the combustion chamber length, injector recess length, and propellant mixture ratio. From the test results, the variation in the pressure fluctuations for each experimental condition was confirmed and the combustion stability was evaluated by stability mapping. It was found that the longitudinal mode and Kelvin-Helmholtz instabilities occurred due to the change in the combustion chamber and recess lengths.

• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.214-221
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• 1995

When the broad pressure region (0.5-3.5 atm) of laser media is pumped by 70 ns [FWHM] electronbeam accelerator (800 kV, 21 kA), the correlation between free-runnuing XeF$(C\rightarrowA$ excimer laser output and Xe concentration are studied. The resonator consisted of dichroic output coupler, and the laser output is optimized with laser media $(Xe/F_2/Ar)$ as functions of total pressure and gas mixing ratio. Under the condition of F2 0.46% fixed, the laser intrinsic efficiencies of 0.38%, 1.03%, and 0.29% are obtained at 1. 2, and 3 atm, respectively. So then the peaks of laser intrinsic efficiency occured to the higher Xe concentration with decreasing total gas pressure. By analyzing the kinetics for the $XeF^*(C)$ formation efficiency and XeF$(C\rightarrowA$ laser extraction efficiency the dependence of Xe concentration on their correlation is explained. As the results we propose efficient operation of an atmosphericpressure XeF$(C\rightarrowA$ laser. laser.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.137-141
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• 1992

To investigate some factors on oleoresin extraction from red pepper, the content of yield, capsanthin and capsaicin in oleoresin extracted under various factors such as solvent, variety of materials, extraction time and temperature, storage condition of dried red pepper and its parts, particle size of raw material powder and the ratios of red pepper powder to extraction solvent were investigated. Ethyl alcohol and ethylene dichloride were effective in extracting capsanthin and capsaicin from red pepper, respectively. Mixed-solvent bore fruitful in increasing of oleoresin yield, but was fruitless in extracting capsanthin and capsaicin in comparison with single-solvent. In three varieties such as Juktoma, Jinsol and Dabok, Jinsol was excellent in oleoresin extraction. Optimum extracting temperature and time was $20^{\circ}C$ and three to five hours, respectively. Oleoresin quality from long-term storage and/or coarse red pepper were low in point of yield, capsanthin and capsaicin. Capsanthin and capsaicin were distributed into pericarp and seed in abundance, respectively. Optimum mixing ratio of red pepper powder to extracting solvent was suitable for one to three(1 : 3) or one to four(1 : 4) in oleoresin extraction.

• Progress in Superconductivity and Cryogenics
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• v.14 no.4
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• pp.50-53
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• 2012

This paper describes experimental study on GM-type pulse tube refrigerator (PTR). In a PTR, the pulse tube is only filled with working gas and there exists secondary flow due to a large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus, the cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube refrigerator is fabricated and tested. The cooing performance of the fabricated PTR is measured as varying cold-head orientation angle and the results are used as reference data. Then, we divided interior space of pulse tube into three segments, and fixed the various size of screen mesh at interface of each segment to suppress the performance degradation due to secondary flow. For various configuration of pulse tube, no-load test and heat load test are carried out with the fixed experimental condition of charging pressure, operating frequency and orifice valve turns. From experimental results, the fine screen mesh shows the effective suppression of performance degradation for the large orientation angle, but the use of screen mesh cause the loss of cooling capacity rather than the case of no insertion into pulse tube. It should be compromised whether the use of screen mesh in consideration of the installation limitation of a GM-type pulse tube refrigerator.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.4
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• pp.41-48
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• 1999

Silica is the most popular materials as a filler of EMC for microelectronic packaging. However, because of its low thermal conductivity, the use of silica is restricted to parts requiring high thermal dissipation. The superior fluidity of EMC can be achieved with a combination of filler size distribution. In this study, physical properties of EMC filled with the crystalline silica(13$\mu\textrm{m}$) which have high fluidity and low cost and the AlN(2 $\mu\textrm{m}$) which have high thermal conductivity and low coefficient of thermal expansion were evaluated by changing the AlN/silica ratios. As a result of the evaluation of physical properties of EMC, the optimum mixing ratio of AlN/crystalline silica was 0.3/0.7. In this condition, binary mixture(AlN/crystalline silica) filled EMC showed superior properties, i.e., in the thermal conductivity, CTE, dielectric constant, flexural strength, and thermal shock resistance without reduction of fluidity.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.44-50
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• 2013

Process gas piping is one of the most basic components frequently used in the refinery and petrochemical plants. Many kinds of by-product gas have been used as fuel in the process plants. In some plants, natural gas is additionally introduced and mixed with the byproduct gas for upgrading the fuel. In this case, safety or design margin of the changed piping system of the plant should be re-evaluated based on a proper design code such as ASME or API codes since internal pressure, temperature and gas compositions are different from the original plant design conditions. In this study, series of piping stress analysis were conducted for a process piping used for transporting the mixed gas of the by-product gas and the natural gas from a mixing drum to a knock-out drum in a refinery plant. The analysed piping section had been actually installed in a domestic industry and needed safety audit since the design condition was changed. Pipe locations of the maximum system stress and displacement were determined, which can be candidate inspection and safety monitoring points during the upcoming operation period. For studying the effects of outside air temperature to safety the additional stress analysis were conducted for various temperatures in $0{\sim}30^{\circ}C$. Effects of the friction coefficient between the pipe and support were also investigated showing a proper choice if the friction coefficient is important. The maximum system stresses were occurred mainly at elbow, tee and support locations, which shows the thermal load contributes considerably to the system stress rather than the internal pressure or the gravity loads.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.89-94
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• 2006

Traditionally fatty acid composition used to be analysed by a GC and the sample preparation process includes lipid extraction from sample and subsequent methyl esters preparation, which are time-consuming and cumbersome. As an alternative, simultaneous extraction/methylation methods are being developed for rapid and simplified sample preparation. To optimize one-step extraction/methylation method for analysis of fatty acid composition in brown rice, various reaction factors such as sample to reaction solution ratio, reaction time and temperature, shaking intensity were changed and resultant fatty acid composition data were evaluated in comparison with previous reports. The ratio of sample weight to reaction solution volume was the most critical factor in that higher sample to reaction solution ratio caused overestimation of palmitic acid and linoleic acid composition, resulting in underestimation of oleic acid. Lower reaction temperature also induced overestimation of linoleic acid and underestimation of oleic acid. Reaction duration and the intensity of shaking prior to and during the reaction, however, caused no significant changes in analysis results. In conclusion, the optimum condition was mixing 5 grains (about 0.2 g) of brown rice with $680{\mu}L$ of extraction/methylation mixture and $400{\mu}L$ of heptane, followed by reaction at $80^{\circ}C$ for 2 hours.