• Asian Journal of Turfgrass Science
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• v.6 no.2
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• pp.73-81
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• 1992

This study was designed to estimate on the interaction of the first productivity, light condition and to examine the ecophysiological 'characteristics of Zoysia japonica. Artificial community of Zoysia japonica was analyzed effect of matter production and growth construction under various shading condition. The results summarized this experiment were as follows ; 1. The relative growth rate(RGR) in all experimental plots was high during the growth stage of 20 days after transplanting and then tend to decrease. RGR value in severe shading or short day condition was remarkably decreased from the early growth stage. 2. The net assimilation rate(NAR) was high during the early growth stage after transplanting. and then decreased the growth proceeded. NAR value in the severe shading or short day condition plots was low. 3. The increasing rate of leaf ared ratio(LAR) was high during the early growth stage after transplanting in the control plot and 30% shading plot, but it appeared to be high 40 days after transplanting in the 50% and 70% shading plot. LAR was appeared to be negative correlation against RGR and NAR. 4. The crop growth rate(CGR) in each experimental plot was increased until 50 days after transplanting, and then decreased. After that time, the maximum CGR value appeared in the control plot(1.56g /g, 10days), 60days after transplanting. CGR had positive correlation with LAI. The optimum LAI in the control, 30%, 50%, and 70% shading plots was appeared as 2.10, 1.75, 1.25, and 0.90.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.268-275
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• 2006

ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide by the action of the protoporphyrinogen IX oxidase (Protox IX). A study was conducted to determine photodynamic herbicidal effect of ALA on seedling growth of rice (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) under dry and wet conditions. ALA effect on early plant growth of rice and barnyardgrass was greatly concentration dependant, suggesting that it promotes plant growth at very low concentration and inhibits at high concentration. No significant difference in herbicidal activity of biologically and synthetically produced ALAs on plant lengths of test plants was observed ALA exhibited significant photodynamic activity regardless of PSDIP and its duration. Significant shoot growth inhibition by ALA soaking treatment exhibited apparently, indicating that ALA absorbed through root system was translocated into shoot part of plants. ALA reduced plant heights of rice and barnyardgrass seedlings by 6% and 27%, respectively, showing more tolerant to ALA in rice under wet condition. Leaf thickness was reduced markedly by ALA with increasing of ALA concentration, due to mainly membrane destruction and severe loss of turgidity in mesophyll cells, although the epidermal was little affected. It was observed that photodynamic herbicidal activity of ALA applied by pre-and post-emergence application exhibited differently on plant species, and that the activity of ALA against susceptible plants was highly correlated with growing condition.

• KSBB Journal
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• v.30 no.1
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• pp.33-37
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• 2015

Recently, several health benefits of rice wine, makgeolli, were known due to the interest on the traditional Korean liquor and the researches on the rice wine are increasing. Organic acids produced during the process of rice wine fermentation play important roles in the taste and flavor. In this study, we have examined the optimal conditions for lactic acid production in rice koji as a carbon source. Skim milk was also used as a supplementary ingredient for the optimization of lactic acid fermentation. Bacterial growth of Lactobacillus sakei was monitored under this condition. The pH, acidity of the culture and the ethanol tolerance of this bacterium were also tested. Through these experiments, we were able to optimize the growth condition of lactic acid bacteria by the addition of skim milk. This was also able to affect the change of pH, acidity, sugar concentration and alcohol tolerance, which might contribute to the improvement of the quality of rice wine. The optimal condition for the growth was 2 days with 10% (w/v) of skim milk concentration. With these results, it was confirmed that rice koji was an effective carbon source for the growth of lactic acid bacteria.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.4
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• pp.151-157
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• 2014

The degradation mechanisms of thermal barrier coatings (TBCs) were investigated in different thermal fatigue condition in terms of microstructural analyses. The isothermal and cyclic oxidation tests were conducted to atmospheric plasma sprayed-TBCs on NIMONIC 263 substrates. The delamination occurred by the oxide layer formation at the interface, the Ni/Cr-based oxide was formed after Al-based oxide layer grew up to ${\sim}10{\mu}m$ in the isothermal condition. In the cyclic oxidation with dwell time, the failure occurred earlier (500 hr) than in the isothermal oxidation (900 hr) at same temperature. The thickness of Al-based oxide layer of the delaminated specimen in the cyclic condition was ${\sim}4{\mu}m$ and the interfacial cracks were observed. The acoustic emission method revealed that the cracks generated during the cooling step. It was considered that the specimens were prevented from the formation of the Al-based oxide by cooling treatment, and the degradation mode in the cyclic test was dominantly interfacial cracking by the difference of thermal expansion coefficients of the coating layers.

• Journal of Applied Reliability
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• v.14 no.2
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• pp.129-136
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• 2014

Reliability test is focusing to detect the unexpected reliability failure and solve them for the high quality of products. The test data should be used to assess and project the current level of interesting product reliability and so it is very important to have the accurately assessing methodology with test data. There are two type of trend for test data as constant and changing one during testing and this paper shows the difference in the assessing results of these two cases. There is less information how to define the existence of reliability growth rate changing and calculate the parameters of the reliability growth models to make an accurate assessment with such condition, so i established the process and mathematical model to calculate the parameters at such condition to make reliability growth curve with high Goodness of Fit. I validated the new method with the data made from Monte Carlo Simulation and case from Demko (1993). Even the assessed result with the new methodology may be different with the case by case because of very diversity in test condition and testing product quality, but the process and method founded in this research can be applied to any case using Duane and AMSAA model for their test data assessment. I also present the evaluation method to see the effectiveness with new one which is a conventional knowledge and not popular to use, so it is possible to compare the results with the newly presented and conventional method for better business decision.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.401-407
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• 2006

This study was conducted to investigate the effect of onion cultivation under paddy and upland condition on the yield and storage of onion bulbs. In comparison of soil conditions, nitrogen, phosphate, potassium content and average temperature in upland condition were higher than those of paddy condition, but calcium, magnesium, sodium and water content in paddy condition were higher than those of upland condition. The growth of aerial part was better in upland cultivated condition. It showed that bulb formation in paddy cultivated condition was faster during in early growth stage, but was slower during in late growth stage. Average bulb size and weight were higher in upland cultivated condition, but dry weight per 100 g fresh weight and bulb hardness were higher in paddy cultivated condition. Sugar contents, inorganic compounds, nitrogen, phosphate and potassium content of onion were higher in upland cultivated condition, but calcium, magnesium and sodium content of onion were higher in paddy cultivated condition. In distribution of onion bulb size, most of large sized onions were produced in upland cultivated condition. Average bulb production for seed harvesting were $63{\sim}70%$ higher in paddy cultivated condition than that of upland cultivated condition. The rotted rate of onion was about $27.2{\sim}34.6%$ in paddy, $37.5{\sim}51.4%$ in upland cultivated condition respectively, showed favorable result as the difference of $8.7{\sim}24.2%$ in paddy cultivated condition.

• Environmental Engineering Research
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• v.23 no.2
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• pp.216-222
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• 2018

The growth characteristics of Spirulina platensis were investigated using four photo-bioreactors with $CO_2$-mixed air flows. Each reactor was operated under a specific condition: 3% $CO_2$ at 50 mL/min, 3% $CO_2$ at 150 mL/min, 6% $CO_2$ at 50 mL/min, and 6% CO2 at 150 mL/min. The 3% $CO_2$ at 150 mL/min condition produced the highest algal growth rate, while the 6% $CO_2$ at 150 mL/min conditioned produced the lowest. The algal growth performance was suitably assessed by the linear growth curve rather than the exponential growth. The medium pH decreased from 9.5 to 8.7-8.8 (3% $CO_2$) and 8.4-8.5 (6% $CO_2$), of which trends were predicted only by the pH-carbonate equilibrium and the reaction kinetics between dissolved $CO_2$ and $HCO_3{^-}$. Based on the stoichiometry between the nutrient amounts and cell elements, it was predicted that depleted nitrogen (N) at the early stage of the cultivation would reduce the algal growth rates due to nutrient starvation. In this study, use of the photobioreactors capable of good light energy distribution, proper ranges of $CO_2$ in bubbles and medium pH facilitated production of high amounts of algal biomass despite N limitation.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.501-506
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• 2001

The creep crack growth properties in 3.5NiCrMoV steel were investigated at $550^{\circ}C$ by using CT specimen under constant $C_t$ condition that was held during crack growth of 1mm distance. $C_t$ lely on load line displacement rate and $C^*$ usually increase with crack length though load is reduced in order to maintain constant $C_t$ value as crack growth. Fully coalesced area(FCA) ahead of crack tip tend to increase as $C_t$ increase to the critical value, and after that value FCA decrease. For the tertiary creep stage of crack growth test, the most of displacement is due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of $C_t$. At constant load and $C_t$ region, crack growth slope was 0.900 and 0.844 each, on the other hand $C^*$ slope was 0.480.

• Mycobiology
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• v.34 no.2
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• pp.83-91
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• 2006

Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.1-11
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• 2004

The purpose of this study was to determine usability as potted flowers and garden plants by controlled plant height using growth retardants. There was no significant difference on the dwarfing effect according to the degree of exposure the sun, but growth was well under full exposure to the sun. The plant height was decreased by application of Cycocel (CCC), Bonzi (paclobutrzol), Ancymidol, and Uniconazole compared to the control group, and treatment of Bonzi $5mg{\cdot}L^{-1}$ was most dwarfing effect for both full sun exposure or 70% controlled shading condition. No consistent different was found in stem diameter, leaf color change, the content of chlorophyll and anthocyanin when the concentration of plant growth retardants was altered. These factors were affected only by light intensity. In comparison to the results of the control group, leaf length, leaf width, plant width and petiole length were all reduced by the application of growth retardants.