• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.1-8
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• 2012

Characteristics of smoke emission in light duty diesel vehicles was investigated according to the year of production, engine displacement volume, and mileage. The smoke emission was measured using light extinction smoke measurement method under free acceleration test mode. Total number of the tested vehicles was 180. The year of production of the tested vehicles distributed from 2002 to 2007. The displacement volumes of the tested vehicles were categorized as 2-liter, 2.5-liter, 2.7-liter, and 3-liter. The mileage of the tested vehicles distributed from 20,000 km to 400,000 km. The more recent in the year of production of the tested vehicles did not show clearly lower in smoke emissions. Smoke emission showed different values according to driver's pedal pushing pattern. Also, smoke emission peak for each free acceleration test initially increased and reach a maximum of the peak values. Afterwards, the smoke peak gradually decreased as number of test increased. A new guide line was proposed to determine the smoke value from the light duty diesel vehicles based on smoke emission peak patterns which were obtained with several repeated free acceleration tests.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.453-458
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• 2000

The paper describes a study of the variation of the NO production emitted from turbulent propane flames established on a practical combustor where a primary and a secondary fuel lines are installed. The flowrate of the secondary fuel is pulsated or added in addition to that of the primary fuel which constrantly flows to the nozzle of the burner. Two modes depending on the positions of supplying the secondary fuel are performed; one is for its position to be placed at the center of the primary fuel tube and the other around the stabilization baffle. The mean concentrations of gas species, $O_2,\;Co\;CO_2,\;NO$, and HC(unburnt hydrocarbones) have been measured at the exit of the combustor. As equivalence ration $({\Phi})$ is increased the profile of the NO concentration on the latter mode rises slowly less than that on the former one. In the range of ${\Phi}=0.5$ to 0.54 the NO production is reduced by about 35% more on the latter mode than on the former one. The influence of pulsating the secondary fuel on the variation of the NO concentration doesn't appear at both modes.

• Journal of Biosystems Engineering
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• v.37 no.6
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• pp.385-397
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• 2012

Purpose: Drying characteristics of sawdust was studied under batch mode using lab scale microwave dryer. The objective of this study was to investigate the effect of material load and microwave output power on drying characteristics of sawdust. Methods: Material load and microwave output power were varied from 23 to 186 g and 530 to 370 W respectively. Different kinetic models were tested to fit the drying rates of sawdust. Similarly, the activation energy was calculated by employing the Arrhenius equation. Results: The drying efficiency increased considerably, whereas the specific energy consumption significantly decreased with increase in material load and microwave output power. The cumulative energy efficiency increased by 9%, and the specific energy consumption decreased by 8% when the material load was increased from 23 to 186 g. The effective diffusivity increased with decrease in material load and increase in microwave output power. The previously published model gave the best fit for data points with $R^2$ and RMSE values of 0.999 and 0.01, respectively. Conclusions: The data obtained from this study could be used as a basis for modeling of large scale industrial microwave dryers for the pellet production.

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.360-367
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• 1994

The effect of various nutrients for the production of the anti-complementary polysaccha- ride by Flammulina velutipes, was examined and the partial purification of the polysaccharide was carried out. The culture conditions and medium compositions considerably influenced the anti-complementary activity of the polysaccharides. When a culture was carried out at 23$\circ$C and pH 5.5 for 6 days in the synthetic medium supplemented with galactose and NaNO$_{3}$, the production of the anti-complementary polysaccharide was maximized. The crude polysaccharide, FV-1 was isolated from the culture broth and partially purified into two fractions, FV-1-II and FV-1-III by gel filtration using Sephadex G-100. FV-1-II was mainly consisted of xylose, mannose, galactose and glucose, and rhamnose, mannose and galactose, for FV-1-III. Also, the anti-complementary activity of FV-1-III was reduced partially in the absence of the Ca ion. When crossed immunoelect- rophoresis using anti-human C3 serum was carried out after incubation of normal human serum with the FV-1-III in the Ca ion free condition, a cleavage of C3 precipitin line was observed. These results indicate that the mode of complement activation by polysaccharide from Flammulina velutipes is via not only the classical pathway but also the alternative pathway.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.588-594
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• 1998

Lactic acid bacteria were isolated from Kimchi and screened for bacteriocin production. Strain SE1, identified as Lactobacillus curvatus sp., showed the strongest inhibitory activity against Lactobacillus delbrueckii subsp. delbrueckii. The bacteriocin was inactivated by amyloglucosidase, trypsin, or protease K treatment. However, it maintained its activity under heat treatment at $100^{\circ}C$ for 60 min. The production of the bacteriocin had a growth-related mode and decreased around the early-stationary phase. The optimum temperature for the growth of L. curvatus SE1 was $37^{\circ}C$; however, the optimum temperature for bacteriocin production was $30^{\circ}C$. The bacteriocin activity was decreased by treatment with methanol, butanol, acetone, or chloroform, however, it was not affected by treatment with ethanol, iso-propanol, or cyclohexane. The inhibitory activity of bacteriocin was stable over a wide range of pHs (2 to 11). The bacteriocin from L. curvatus SE1 killed the indicator strain by a bactericidal mode of action. The bacteriocin from L. curvatus SE1 was partially purified by ethanol precipitation and ion exchange chromatography. SDS-polyacrylamide gel electrophoresis was used to determine the molecular weight of the bacteriocin by the bacteriocin activity test. The apparent molecular mass of the bacteriocin produced by L. curvatus SE1 was about 14 kDa.

• Journal of Aquaculture
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• v.20 no.3
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• pp.194-198
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• 2007

Reproductive traits of Palaemon gravieri such as embryo size, number of embryo (fecundity), incubation period, larval development mode, larval development period, larval survival and larval growth were described and compared to analyze the correlation among those traits. Embryo volume is a primary factor determining other ensuing reproductive features. Egg volume was $0.042mm^3$ in the first developmental stage. Embryo volume in P. gravieri was comparatively small which is indicative of great number of embryo (y = 3.0161x + 0.0185 $R^2$ = 0.74 positive isometric relationship) and relatively long incubation period. Larvae survived from zoea 1 to post-larvae and it took 45 days at $22^{\circ}C$. Survival rate of the larvae was rather great in the early stage and thereafter steadily decreased. Daily growth rate of larvae in P. gravieri at $22^{\circ}C$ was 0.0195 mm on average. They grew steadily as time went by. Incubation period was between 10-14 days at $22^{\circ}C$. Larval development mode was almost complete planktotrophic. PNR (point of no return) appeared to be the third day on average. Survival rate of larvae without feeding declined rapidly between 3 and 4 days. Larval development period and stage frequency were 23-30 days and 11 stages which imply prolonged larval period and high mortality. The pattern of brood production followed fast successive parturial pattern. Most ovigerous female had mature ovary when they performed parturial molt soon after hatching (larval release).

• Ocean and Polar Research
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• v.37 no.4
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• pp.333-340
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• 2015

The contrast (fish body to medium ratio) of density and sound speed were measured to estimate acoustic scattering from small juvenile cod (Gadus macrocephalus) with the Kirchhoff-Ray Mode backscatter model. The density contrast was measured by the density-bottle method and the sound speed contrast was estimated by the time of flight method. The results revealed that the measured density contrasts of juvenile cod varied between 1.003 and 1.029 (mean = 1.014, S.D. = 0.01). On the other hand, sound speed contrasts varied between 1.039 and 1.041 (mean = 1.041, S.D. = 0.001). The relationship between averaged target strength (TS) and total length (TL) established by the model were <$TS_{38kHz}$> = 20log(TL) - 68.8 and <$TS_{38kHz}$> = 20log(TL) - 69.4, respectively.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.927-932
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• 2006

S-Adenosylmethionine (SAM) is a ubiquitous biomolecule serving mainly as a methyl donor. Our recent studies revealed that SAM controls antibiotic production in Streptomyces. In this study, the functional mode of SAM was studied in S. coelicolor and S. antibioticus ATCC11891, employing S-adenosylhomocysteine (SAH), a methylation reaction product of SAM. Actinorhodin biosynthesis did not require SAM as a methyl donor, whereas SAH enhanced the actinorhodin biosynthesis up to the level comparable to SAM, and the most effective concentration of SAH was higher than that of SAM. In the case of oleandomycin that requires SAM for its biosynthesis, both SAM and SAH at the concentration as low as 100 mM showed comparable efficacy in enhancing the production; SAM at 1 mM concentration additionally stimulated to give a 5-fold enhancement of oleandomycin production. In vitro autophosphorylation of protein kinase AfsK was found to be activated by both SAM and SAH, as well as other structurally related compounds. Our studies demonstrate that SAM regulates antibiotic biosynthesis in a mode independent of its role as a methyl donor and suggest that SAM acts directly as an intracellular signaling molecule for Streptomyces.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.273-278
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• 1996

The research was undertaken to characterize the reaction mode of transglucosidase (TG) from Aspergillus niger for the production of isomaltooligosaccharides such as isomaltose, panose and isomaltotriose. TG hydrolyzed maltose to glucose units and produced panose and glucose by transglucosylation. TG hydrolyzed panose to maltose and glucose when panose was used as an initial substrate. The reaction patterns of products when isomaltose, isomaltotriose or isomaltotetraose were used as substrates were different from the case when maltose was used as a substrate. Maltotriose and maltose showed the same formation pattern of products. TG also produced isomaltooligosaccharides from maltooligosaccharides. The production of panote by TG from maltose was mathematically described by Michaelis-Menten kinetics. The kinetic constants, $V_{max}$ (the maximum velocity) and $K_m$ (Michaelis constant), were estimated by Lineweaver-Burk plot to be 400 M/min and 21.4 mM, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.156-158
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• 2009

New liquid crystal (LC) host mixtures and reactive mesogens (RMs) designed for the Polymer Sustainable Vertically Aligned (PS-VA) mode have been developed. The novel combination of LC host mixture with RMs enables to show superior LC display performance with high reliability and to contribute for the robust LC panel production process.