• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.859-865
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• 2005

The stimulatory effects of exogenous salicylate as a pathway inducer on phenanthrene biodegradation were investigated using Burkholderia cepacia PM07. The phenanthrene degradation rate was greatly enhanced by increasing the salicylate additions, and the maximum rate was 19.6 mg $I^{-1}\;d^{-1}$ with the addition of 200 mg $I^{-1}$ of salicylate, 3.5 times higher than that (5.6 mg $I^{-1}\;d^{-1}$) without the addition of salicylate. The degradation rate was decreased at higher concentrations of salicylate (above 500 mg$I^{-1}$), and cell growth was significantly inhibited. The phenanthrene degradation was not affected by increasing glucose up to 2 g $I^{-1}$, although dramatic microbial growth was obtained. The stimulatory effect of exogenous salicylate decreased in the presence of glucose. After the addition of 200 mg $I^{-1}$ of salicylate, approximately $60\%$ of the initial phenanthrene (50 mg $I^{-1}$) was degraded after 96 h. However, with extra addition of 200 mg $I^{-1}$ of glucose, the phenanthrene degradation rate decreased, and only $18.5\%$ of the initial phenanthrene was degraded.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.33-39
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• 1985

The effects of initial concentration, flow rate, and recycle ratio on the removal efficiency of phenol were studied in a tapered fluidized bed reactor packed with activated carbon which was attached with Candida tropicalis. The optimum conditions of Candida tropicalis were showed that pH was 7.0 and temperature was $30^{\circ}C$, and the specific growth rate of Candida tropicalis was satisfied with the Monod equation up to 500 mg/L of phenol, and beyond it the inhibition of substrate was found. According to the increases of initial concentration and flow rate, the removal efficiency was decreased, as the recycle ratio was increased, the removal efficiency was increased. In the case of flow rate of 10mL/sec and the recycle ratio of 2, the removal efficiency was 90% above for the all of initial concentration. The removal rate of phenol was the first order reaction in this system, and the rate equation of reaction was as follows.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.194-198
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• 2005

Growth curves of Listeria monocytogenes in modified surimi-based imitation crab (MIC) broth were obtained by measuring cell concentration in MIC broth at different culture conditions [initial cell numbers, $1.0{\times}10^{2},\;1.0{\times}10^{3}\;and\;1.0{\times}10^{4}$, colony forming unit (CFU)/mL; temperature, 15, 20, 25, 37, and $40^{\circ}C$] and applied to Gompertz model to determine microbial growth indicators, maximum specific growth rate constant (k), lag time (LT), and generation time (GT). Maximum specific growth rate of L. monocytogenes increased rapidly with increasing temperature and reached maximum at $37^{\circ}C$, whereas LT and GT decreased with increasing temperature and reached minimum at $37^{\circ}C$. Initial cell number had no effect on k, LT, and GT (p > 0.05). Polynomial and square root models were developed to express combined effects of temperature and initial cell number using Gauss-Newton Algorism. Relative coefficients of experimental k and predicted k of polynomial and square root models were 0.92 and 0.95, respectively, based on response surface model. Results indicate L. monocytogenes growth was mainly affected by temperature and square root model was more effective than polynomial model for growth prediction.

• KSBB Journal
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• v.13 no.3
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• pp.289-294
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• 1998

The effects of various step-fortifications of the initial medium with amino acids, glucose, and vitamines on the growth and metabolism of a hybridoma cell line in batch cultures were quantified. Comparisons between the metabolic rates of the various cultivations were made for the exponential growth phase. Fortification of the basal medium resulted in higher cell densities through a prolonged growth phase, but the maximum specific growth rate was not affected. The uptake rate of glutamine increased with the addition of amino acids but did not change upon the addition of glucose or vitamines. The specific glucose consumption decreased slightly with the addition of amino acids but increased production of lactate and {{{{ { NH}`_{4 } ^{ +} }}}}. A reciprocal relationship between the yields of {{{{ { NH}`_{4 } ^{+ } }}}} and lactate indicated a joint regulation of glycolysis and glutaminolysis.

• Journal of the Korean Ceramic Society
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• v.32 no.5
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• pp.587-593
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• 1995

Abnomal grain growth behavior of BaTiO3 ceramics was investigated with addition of seed grains. It was foudn that the nucleation rate of abnormal grain was constant and growth of abnormal grain was linearly increased with sitnering time, regardless of amount of seed grains. These facts were also confirmed by fitting of the volume fraction of abnormal grain vs. sintering time using Avrami type equation (n=4). It was suggested that seed grains did not change the nucleation rate or growth mechanism of abnormal grain but increase the number of abnormal grains at initial stage of sintering and then it led to fine microstructure of BaTiO3 ceramics.

• Korean Journal of Crystallography
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• v.3 no.1
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• pp.23-30
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• 1992

a-SiC crystals were grown on the (001) plane of a-SiC seed crystals by sublimation method to find effects of pressure-reduction rate of the crystal growth furnace own the growth rate and orientstion of grown SiC crystals. Pressure-reduction rate at the initial growth stage affected the crystallinity of grown SiC crystals. In case of high pressure-reduction rate, growth rate was high and 3csic polycrystalline was grown on the seed. On the other hand, low pressure-reduction rate caused the growth rate to be slow and 6H-SiC single crystal was grown on the seed. However, even after growing SiC for 2 hours under the condition in which.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.282-287
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• 1999

The object of this study was to determine the difference of the time course changes of transpiration, diffusion resistance and photosynthetic rate of rice at several different growth stages subjected to soil moisture stress (SMS) and recovery by irrigation. A japonica rice cultivar 'Dongjinbyeo', was grown under flooded condition in a plastic container filled with silty loam soil. At 5 main growth stages, the container was treated by SMS until initial wilting point (IWP) and then reirrigated. The duration of SMS until IWP were the longest, 13 days for tillering stage, and the shortest, 7 days for panicle initiation and meiosis stage. The transpiration rate rapidly decreased during SMS and the transpiration rate at IWP of the stressed plant showed 10∼20% compared with control, and the transpiration rate of stressed plant at most growth stages also recovered rapidly after irrigation and then reached 100% of control within a week. The shoot photosynthetic rate in all growth stages rapidly decreased by SMS, and the rates at IWP of stressed plants were de-creased nearly to 0%, beside the treatment at tillering stage. The recovery degree of photosynthetic rate by irrigation ranged from 20 to 90%, showed higher at early growth stages of SMS treatment than that of later stages. At all growth stages the leaf diffusion resistance of stressed plants was over 3 times that of the control resulting from a rapid increase at 3 to 5 days after draining for SMS, and showed quick recovery by irrigation within 3 days after drainage. The above physiological parameters changed in close relation with the decrease of the soil matric potential after SMS. These results indicate that at all main growth stages of rice plants the transpiration and photosynthesis reduction by stomatal closure reponded sensitively to the first stage of SMS closely related with decrease of soil water potential, while those recovery pattern and recovered degree by irrigation are little different by growth stage of rice.

• ALGAE
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• v.25 no.1
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• pp.17-26
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• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• Research in Community and Public Health Nursing
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• v.31 no.1
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• pp.86-95
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• 2020

Purpose: The aim of this study was to examine the correlation between school-life adjustment and suicidal ideation in adolescents by applying the latent growth curve models to the longitudinal data. Methods: This study analyzed three waves of data from the Korean Children & Youth Panel Survey (2014~2016). A total of 1,534 students were included in the analysis. In the application of the latent growth curve models to the longitudinal survey data, we analyzed the initial status and growth changes for each wave, identified individual differences in the general characteristics, and examined the direct relationship between the two latent constructs. Results: The analysis revealed that variations in the initial status and rate of school-life adjustment were significant with respect to parents' education level, household income and academic satisfaction. Variations in the initial status and growth rate of suicidal ideation were significantly associated with household income and family structure. The relationship between school-life adjustment and suicidal ideation showed a negative correlation in which the starting value of the former increased and that of the latter decreased and vice versa. Conclusion: The results confirmed that school-life adjustment and suicidal ideation varied according to students' general characteristics. In addition, school-life adjustment was negatively correlated with suicidal ideation, thereby highlighting students' ability to adjust as an important factor influencing their suicidal thinking.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.69-72
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• 2000

After 300hours cultivation Chlorella vulgaris in standard medium in which the initial cell seeding concentration of $0.7{\times}10^4ells/mL$, $1.21{\times}10^5ells/mL$ was gained but in the case of 0.30g/L of initial cell seeding concentration the maximum growth rate of $0.162g/L\;{\cdot}\;day$ was shown. In the case of the initial glucose concentration of 2.00g/L, the cell concentration was changed from initial 0.025g cells/L to 0.874g cells/L after 140hours cultivation, the specific growth rate was $0.243h^{-1}$, but 268mL of gases were formed in 72hours, and after that, hydrogen evolution was completed. Formed gases were not all hydrogen, and 19.87 mol% of hydrogen is detected by GC. Analyzing the composition of Chlorella vulgaris by elementary analysis, it is found to be $C_{1.000}\;H_{1.774}\;N_{0.125}\;O_{0.557}$, and $CO_2$ conversion rate by Chlorella vulgaris was $0.616\;cells/g\;{\cdot}\;CO_2$