• Weed & Turfgrass Science
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• v.4 no.4
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• pp.397-404
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• 2015

This study was conducted to find out the optimum nitrogen fertilization for production of good quality and high yield zoysiagrass (Zoysia japonica Steud.), the changes in chemical properties of soil in pot and field experiments treated with different levels of nitrogen fertilizer. In pot experiment, the fresh and dry weights of shoots and stolons and the number of shoots increased as nitrogen levels increased, and showed no significant between 24 and $48kg\;N\;10\;a^{-1}$. In field experiment, the shoot length, fresh and dry weights of shoots, roots and stolons, the number of shoots and total stolons length linearly increased as affected by increased nitrogen application, and were not significantly different between 24 and $32kg\;N\;10\;a^{-1}$. In both experiments, pH and exchangeable cations ($Ca^{2+}$ and $Mg^{2+}$) in soil decreased as the rate of nitrogen application increased. As a results, chemical properties of soil were more deteriorated in the plots of higher nitrogen fertilizer rate. Thus, these results demonstrated that the nitrogen fertilizer rate for maximum growth of zoysiagrass was $24kg\;N\;10\;a^{-1}$ in consideration of growth and soil condition.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.567-572
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• 1994

Diglyceride was prepared by reaction of hydrogenated beef tallow and glycerol (GL) in the presence of a Pseudomonas lipase. Both substrates were mixed at the ratio of GL/Triglyceride of 0.5 which is the stoichiometric molar ratio for the complete conversion of triglyceride (TG) to diglyceride (DG). DG can be obtained by solid phase-glycerolysis of hydrogenated beef tallow without use of organic solvents or emulsifiers by careful control of reaction temperature. Optimized reaction temperature condition was as follows: An initial incubation at$60^{\circ}C$ for 2h followed by the first temperature shift down to $55^{\circ}C$ for 4h, and then the second shift down to $50^{\circ}C$ for up to 3 days. There was a large decrease in the content of TG during the first $60^{\circ}C$ incubation for 2h. Even a prolonged incubation at $60^{\circ}C$ could not make a change of the composition of the reaction mixture at liquid state. By controlling the temperature lower than $60^{\circ}C$, reaction mixtures were solidified. The reaction temperature at $50^{\circ}C$ below the melting temperature of hydrogenaed beef tallow gave an 71% optimum yield of DG after 72h enzymatic glycerolysis and about 73% of total DG was 1,3-DG.

• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.124-128
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• 2012

When ginseng seedlings are cultured in paddy fields, quality degradation and yield reduction are induced by severe plant loss with chlorosis on leaves occurred physiological disorder by excessive salt and poor drainage, rusty-root occurrence, and root rot etc. Accordingly, in order to solve these problems, this study was performed to investigate the treatment method, concentrations and time of activated ion calcium as environment-friendly agricultural materials. Activated ion calcium is an enriched and purified water-soluble mineral calcium component for absorbing quickly into plant as a highly functional calcium and it is an alkaline calcium of 37% (370 $m{\ell}$/1 ${\ell}$) concentration with pH 13. Treatment method was that ginseng seeds were sown after removing water in the shade after seed immersion for 1 minute with active ion calcium of 20-fold diluted solution, and then irrigated $4{\ell}$ per 3.3 $m^2$ with 200-fold, 400-fold, and 600-fold diluted solution before emergence on late March, and supplied 1 time on leaves with 500-fold diluted solution in June and July respectively. The disease rate by treatment of activated ion calcium was that on the treatment of soil irrigated with 200-fold diluted solution compared to non-treated soil, damping-off was 33%, anthracnose was 100% reduced and the occurrence rate of rusty-root was 30% reduced. In addition, when active ion calcium of 200-fold diluted solution were soil irrigated, first and second grade ginseng were respectively 26% and 22% produced more, compared with control.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.155-160
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• 2000

Pseudomnas sp. HJ-2 is capable of producing a rubber-elastic polyhydroxyalkanoate (PHA) consisting of 3- hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyheptanoate (3HHp) from heptanoic acid as the sole carbon source. The polyester produced was a blend of poly(3HB-co-3HV) and poly(3HHp). Although the mixing of poly(3HHp) fraction to poly(3HB-co-3HV) resulted in a decrease of modulus, the sole fraction of poly(3HB-co-3HV) with a high molar fraction of 3HV was shown to be an elastomer with the maximum percent strain of 740%. The biomass yield and the PHA synthesis were relatively high when the initial heptanoic acid concentration was 40 mM, and were significantly decreased when the substrate concentration exceeded 50 mM. The accumulation of PHA was stimulated by deficiency of nitrogen and phosphorus in the medium. The PHA contents and its monomeric compositions were greatly affected by pH and oxygen transfer rate. At pH 7.5, poly(3HB-~0.38% 3HV) was produced from heptanoic acid and a mixture of 95% 3HHp and 5% 3HV was produced at pH 8.0. Increased conten1 of 3HHp in the polyesters with lhe increasing oxygen transfer rate by agitation speed a1 a fixed aeration rate was observed.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.203-209
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• 2007

Soybean milk cake (SMC) was used for the solid-state fermentation by Bacillus subtilis PUL-A isolated from soybean milk cake. In the presence of 5% glutamate the maximum production of biopolymer (59.9 g/kg) was performed by fermentation at $42^{\circ}C$ for 24 hr. The recovered biopolymer was consisted of 87% $\gamma$-polyglutamic acid with molecular weight of $1.3{\times}10^6$ dalton and other biopolymer. The biopolymer solution showed the great decrease in consistency below pH 6.0, regardless of the molecular weight of PGA. Biopolymer solution has a typical pseudoplastic flow behavior and yield stress. The consistency of biopolymer solution was greatly decreased by increasing heating time and temperature in acidic condition compared to the alkaline condition. In kaolin clay suspension, the flocculating activity of biopolymer was the highest value with 15 mg/L biopolymer and 4.5 mM $CaCl_2$, but decreased greatly with $FeCl_3$. The flocculating activity of biopolymer was maximum at pH5, but decreased drastically by heating at $60{\sim}100^{\circ}C$. In particular, biopolymer with native PGA showed the efficient flocculating activity compared to that of modified biopolymer containing low molecular weight of PGA.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.873-882
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• 2009

Sonolysis of TCE (Trichloroethylene) was performed in 584 kHz rectangular reactor. At first, the effect of acoustic power and aqueous temperature which are both important factors to operate ultrasound system on sonolysis of TCE were examined under one side irradiation condition. First degradation rate constants of TCE and chloride yields were increased with increasing acoustic power from 100 to 300 W. And increasing the aqeuous temperature resulted in the increase of first degradation rate constants of TCE and the decrease of chloride yield. Sonolysis of TCE was performed under multi ultrasound irradiation conditions that total acoustic power of 300 W was distributed according to the number of irradiation sides. First degradation rate constants of TCE followed the order 4 sides > 3 sides > 1 side > 2 sides (parallel) > 2 sides (orthogonal). When comparing the experimental results under parallel and orthogonal irradiation conditions of 2 sides with 300 and 450 W, first degradation rate constants of TCE were similar, while production rate constants of hydrogen peroxide were more higher at parallel conditions compared to orthogonal conditions.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.105-109
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• 2005

To enhance salidroside productivity from a cell suspension cultures of Rhodiola sachalinensis, various combinations of auxin (NAA) and cytokinins (BA, Kinetin) concentration and addition of $GA_3$, TDZ, zeatin, spermine and spermidine at a hormone combination to be established were examined. NAA/BA combination is superior to NAA/kinetin combination in biomass and salidroside content. Maximum salidroside production ($64.6{\pm}8.9\;mg/L$ medium) was obtained from $2B_5$ medium with 1 mg/L NAA and 5 mg/L BA. The adding of $GA_3$ ($0.01\;mg/L{\sim}5\;mg/L$) was beneficial for salidroside accumulation and the highest productivity of salidroside, $90.3{\pm}8.34\;mg/L$, was obtained from $2B_5$ medium supplemented with 1 mg/L NAA, 5 mg/L BA and 0.1 mg/L $GA_3$. On TDZ, zeatin, spermine and spermidine, expectant results were not obtained except a little affirmative effect of spermidine ($69{\pm}2.88$ at 1 mg/L).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.47-53
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• 2014

Three kinds of crystalline silicon have been used for the solar cell grade. First of all, single crystalline silicon is the main subject to enhance the production yield. Most of the efforts are focused on the control of the melt-crystal interface shape affected by the crystal-crucible rotation rate. The main subject in the multi-crystalline silicon ingot is the contamination control. Faster Ar gas flow above the melt surface will lower the carbon contamination in the crystal. And also, twin boundary electrically inactive is found to be more effective than grain boundary for the improvement of the MCLT. In the case of mono-like silicon material, propagation of the multi-crystalline silicon growing from the inner side crucible is the problem lowering the portion of the single crystalline part at the center of the ingot. Crystal growing apparatus giving higher cooling rate at the bottom and lower cooling rate at the side crucible was suggested as the optimum solution obtaining higher quality of the mono-like silicon ingot. Proper application of the seeds at the bottom of the crucible would be one of the solutions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.3
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• pp.99-105
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• 2018

In order to avoid un-uniform crystallization on the surface of a quartz glass crucible that is known to affect the production yield of the single crystal silicon, Ba (barium) was selected as a crystallization promotor and the inner surface of the crucible was coated using Ba (barium hydroxide octahydrate)-solution by the spray pyrolysis method. For un-coated crucible, it was found that the crystallization of its surface started at $1350^{\circ}C$, and at $1450^{\circ}C$ the surface was uniformly crystallized with ${\beta}$-cristobalite phase. It was found that the crucible coated with Ba began to be crystallized from $1000^{\circ}C$ and was uniformly crystallized on the crucible surface at $1300^{\circ}C$. In this case, ${\alpha}$-cristobalite and needle-shaped $BaSi_2O_5$ phase were created and disappeared as a crystal phase, and the ${\beta}$-cristobalite phase was eventually evenly distributed over the Ba-coated crucible surface.

• Journal of Technologic Dentistry
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• v.32 no.2
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• pp.65-74
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• 2010

Purpose : To understand the impact on the strength or restoration force by the change of heating temperature when soldering 18-8 stainless steel round wire which is the chrome-nickel class for dental orthodontic device production. Methods : The following conclusions were made upon the results from tensile strength test, 3 point bending test, and $90^{\circ}$ bending fatigue test with 24 samples that had been applied with condition 1 (before heat treatment - natural) and condition 2 (after heat treatment - mooring 30 seconds after heating up to $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$) to ${\phi}0.4mm$, ${\phi}0.7{\beta}mm$, 18-8 stainless steel round wire (spring hard) by Jinsung Company. Results : When it was heat-treated at $900^{\circ}C$, both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low tensile strengths compared to the heat treated cases at $500^{\circ}C$ and $700^{\circ}C$ Yield strengths of both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$, as well. Upon the results of 3 point bending test, the heat treated case at $900^{\circ}C$ showed very low in both ${\phi}0.4mm$ and ${\phi}0.7mm$, compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Tensile strength of both ${\phi}0.4mm$ and ${\phi}0.7mm$ as well, showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Upon the results of $90^{\circ}$ bending fatigue test, the heat treated case at $900^{\circ}C$ showed the highest wave node resistance in both ${\phi}0.4mm$ and ${\phi}0.7mm$. Conclusion : This study concluded that heating temperature change during wire soldering impacts on the characteristics of orthodntic wire.