• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.66-75
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• 1996

This study was carried out to investigate the effects of high temperature and humidity on the ageing of processed leaf tobacco. Four(1993) or six(1994) grades (Both flued-cured and burley) of processed leaf packed in carton box were stored under the natural and artificial conditions. When the Processed leaf was stored in the controlled mom at 40℃ with 75% R.H.(1993) for 40 days, the leaf pH was decreased. The decreasing rate of leaf pH was similar to that of leaf stored under the natural warehouse condition for 15 months. The degree of lightness and yellowness of leaf also decreased, while the decaying or darkening of the leaf was observed. When the processed leaf was stored in the controlled room at 35℃ with 65% R.H.(1994) for 90 days, the pH of flue-cured was decreased 0.22, which was similar to that of the leaf stored under the natural warehouse condition for 15 months, and the lightness, and redness of the leaf were higher than those of the control. As compared with the leaf stored under the natural condition for 2 years, the smoking quality of leaf stored under this condition was similar or somewhat better. The pH of burley tobacco changed little compared to that of flue-cured during storage in this study.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.331-346
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• 2010

This study was carried out to leach valuable metals from galena using indigenous bacteria with no optimum pH conditions at room temperature. Even in these conditions, the rod-shaped indigenous bacteria, ranging from $0.4{\times}0.2{\mu}m$ to $0.5{\times}1.7{\mu}m$, were attached to the surface of the galena. For the 19 days of the bioleaching experiment, the content of Ph, Fe, Zn ions was found to be 347, 222 and 1.7 times higher than that of the control leaching agent, respectively. Numerous hexagonal column crystals were observed on the surface of galena. Those crystals may be formed from the biooxidation of galena by the indigenous bacteria. XRD analysis showed the peaks of anglesite observed in the bioleached galena. It is expected that more valuable elements can be leached out of the galena, if the bacteria is used under optimum pH and temperature conditions in future bioleaching experiments.

• Structural Engineering and Mechanics
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• v.77 no.6
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• pp.819-830
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• 2021

To evaluate the performance of concrete load bearing walls in a structure under horizontal loads after being exposed to real fire, two steps were followed. In the first step, an experimental study was performed on the thermo-mechanical properties of concrete after heating to temperatures of 200-1000℃ with the purpose of determining the residual mechanical properties after cooling. The temperature was increased in line with natural fire curve in an electric furnace. The peak temperature was maintained for a period of 1.5 hour and then allowed to cool gradually in air at room temperature. All specimens were made from calcareous aggregate to be used for determining the residual properties: compressive strength, static and dynamic elasticity modulus by means of UPV test, including the mass loss. The concrete residual compressive strength and elastic modulus values were compared with those calculated from Eurocode and other analytical models from other studies, and were found to be satisfactory. In the second step, experimental analysis results were then implemented into structural numerical analysis to predict the post-fire load-bearing capacity response of the walls under vertical and horizontal loads. The parameters considered in this analysis were the effective height, the thickness of the wall, various support conditions and the residual strength of concrete. The results indicate that fire damage does not significantly affect the lateral capacity and stiffness of reinforced walls for temperature fires up to 400℃.

• Korean Journal of Plant Resources
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• v.27 no.3
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• pp.263-270
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• 2014

Loranthus tanakae (Franch. & Sav.) is an endangered species of mistletoe, distributed in Korean peninsula. The objective of our research is to determine the effect of storage duration and conditions [air flow (AF) and air tight (AT)] at different temperatures for survivability and germination of mistletoe seeds, and also to monitor the effect of seed scarification on germination in vitro. The result revealed that the seeds stored in natural conditions (no stratification) showed highest survival rate of 100% and retained up to 93.3% even after two months of storage in natural conditions and showed higher germination percentage (90%) compare to after ripened seeds. However, the seed stored at $0^{\circ}C$ decreased the germination percentage (ranged from 63 to 73%). Therefore, it can be confirmed that mistletoe does not need after ripened treatment to promote germination. Our research also showed that the storage of L. tanaka seeds in freezing temperatures of $-20^{\circ}C$ and in room temperature for long time either in AT or AF conditions caused the loss of survival and germination rate. On the other hand, the chemical scarification (0.01N HCl incubation for 12 hrs. at $38^{\circ}C$) method was proven more effective to enhance germination percentage of L. tanakae. Regarding the temperature regime, $22^{\circ}C$ showed early germination of mistletoe seeds in vitro.

• KIEAE Journal
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• v.4 no.3
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• pp.179-186
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• 2004

The evaluation of the indoor environment of the Assembly Hall in the University, which is designed to be a large space, requires efficient design of its heating system that takes into consideration natural convection and the characteristics of the occupant's spaces. Indoor thermal environment was measured in the field and simulated with CFD code. The estimations of temperature distribution and indoor airflow distribution must be carried out simultaneously, as the thermal stratification is induced by natural convection flows. In order to simulate the even distribution of factors affecting the indoor environment, including temperature and airflow, Phoenics is used. The turbulent flow model adopted is the RNG k- model. The inlets and outlets of the air-conditioning systems, material and thermal properties, and the size of the test room ($35m{\times}18m{\times}10m$) are used for the simulation. Since the Assembly Hall is symmetric, half of the space is simulated. A Cartesian grid is used for calculation and the number of grids are respectively $60{\times}45{\times}35$. The results of the computer simulation during winter conditions are compared with the measurements at the typical points in the assembly hall with the heating system. After evaluating the results of the computer simulations, the methods of the heating system and layout are suggested.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.417-423
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• 2005

In order to investigate effects of dyeing conditions on the dyeing characteristics in silk during natural dyeing using indigo plants , various dyeing conditions including the temperature of dyeing solution, dyeing period, the concentration and pH of dyeing solution and mordants were treated. As the temperature of dyeing solution decreases low, the color of silk surface showed lower b value. The color of silk surface showed G line when the dyeing solution was $-5^{\circ}C$ and room temperature and GY line at more than $40^{\circ}C$. Coloring degree increased high as the temperature increases. Dyeing period showed no effect on the surface color, but as dyeing period was longer the coloring degree increased. When the concentration of dyeing solution was $1\~4\%$, the silk was colored to BG line and $5\%$ to B line. The coloring degree increased as the concentration of dyeing solution more increased. The pH of dyeing solution sensitively affected coloring of silk. The pH lower than 7 showed G line, pH 8 showed GY line and pH 9 showed YR line. Coloring degree decreased as pH was more increases. Surface color of silk was different according to the kinds of natural mordants and coloring degree was increased by the natural mordants.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.79-87
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• 2010

Research was initiated to investigate the early establishment characteristics and germination patterns of perennial ryegrass (PR, Lolium perenne L.). Eight cultivars of PR were evaluated in the study. Experiment was conducted under a room temperature condition of $6^{\circ}C$ to $23^{\circ}C$ (natural conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and germination percentage with different environments and cultivars. Germination percentage was variable with cultivars at the end of study. It was 66.25 to 93.50% under natural conditions. There were considerable variations in the early germination characteristics and germination pattern among the entries according to different conditions. The first germination was initiated between 3 and 5 DAS (days after seeding) under ISTA (International Seed Testing Association) conditions. But it started between 6 and 8 DAS under natural conditions, being 2 to 4 days later as compared with that under ISTA conditions. It was 8 to 12 DAS that reached to days to the 50% germination, which was 2 to 5 days after the first germination. Days to the 75% germination were 10.08 to 13.70 DAS under natural conditions, being 2.07 to 5.70 days slower as compared with ISTA conditions. 'Pennant II' was the fastest cultivar. But the slowest was 'Catalina II' that was 3.62 days later than 'Pennant II' under natural conditions. Considering days to the first germination, days to 75% germination, and germination pattern etc, 'Pennant II' and 'Brightstar II' were regarded as excellent cultivars under both conditions. From this study, information on differences in germination characteristics and patterns would be usefully applied for golf course design and construction, when established with PR.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.226-232
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• 2017

Dhup (Canarium resiniferum) is an economically and aesthetically important rare native tree species of Bangladesh. In natural condition 78.5-98.7% seeds do not germinate due to inhibition by hard seed coat, seed predation and unfavorable environmental conditions. A study was conducted in the Seed Research Laboratory and nursery of Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh in 2013 to find out appropriate pre-sowing treatments for maximizing germination and initial seedling growth. Eleven pre-sowing treatments were provided in both the seeds sown in polybags and seeds sown in propagator house. Results revealed that, germination started at first (after 20 days of seed sown) in seeds immersed in water at room temperature for 24 hours and germination completed within 38 days. Significantly higher (p<0.05) germination percentage (33%), germination energy (16.7%), plant percent (33%) and germination value (0.4) was found with seeds immersed in water at room temperature for 24 hours. Seedling height measured at three, four and five months after the seed germination in case of seeds treated by immersion in water for 24 hours was also greater than others. Therefore, pre-sowing treatment by immersion in water at room temperature for 24 hours was more effective in germination and production of quality vigor seedlings of Dhup.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.41-47
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• 2009

This study investigated antioxidative and hypoglycemic activities of Omija for evaluation of usefulness as a functional food resource. Omija water extracts were extracted with water for 24 hr, 6 hr and 3 hr at room temperature, 60$^{\circ}C$ and 100$^{\circ}C$, respectively. Omija ethanol extracts were extracted with 60% ethanol for 24 hr and 3 hr at room temp temperature and 60$^{\circ}C$, respectively. The antioxidant properties of Omija(Schizandra chinensis Baillon) extracts prepared under different extraction conditions were evaluated by a variety of radical scavenging assays including DPPH, $ABTS^{{cdot}+}$, and nitrite and reducing power. Hypoglycemic activity was examined for $\alpha$-glucosidase inhibition using an in vitro model. The total phenolic content was also determined. Antioxidant activities of Omija were the highest in the group extracted with 60% ethanol for 3 hr. The ethanol extracts showed higher activity than water extracts. An extraction temperature was the highest in 60$^{\circ}C$. The total phenolic content extracted with 60% ethanol for 3 hr at 60$^{\circ}C$ was 530 mg GAE/100 g. The water extract extracted with water for 24 hr at room temperature showed the lowest antioxidant activity and phenolic content. $\alpha$-glucosidase inhibitory activity was the highest in the group extracted with 60% ethanol for 3 hr at 60$^{\circ}C$, followed by the group extracted with 60% ethanol for 24 hr. The results suggest that extraction of Omija by 60% ethanol for 3 hr at 60$^{\circ}C$ will be useful as a functional food resource with natural antioxidants and hypoglycemic activities.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.274-282
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• 2013

Research was initiated to investigate early germination and establishment characteristics of perennial ryegrass (PR, Lolium perenne L.). An alternative condition was applied in Experiment I with 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA condition). Experiment II was conducted under $5^{\circ}C$ to $25^{\circ}C$ (natural condition). Significant differences were observed in germination percentage, germination speed and germination peak time. Seed germinating vigor was 66.00 to 93.75% under ISTA and 66.25 to 93.50% under natural conditions. Germination speed, measured as days to germination of 50% through 90%, was much faster with 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' under ISTA conditions. But it was faster only with 'Pennant II' and 'Brightstar II' under natural conditions. Germination peak time ranged 1.48 to 5.65 days under ISTA, while 2.17 to 10.63 days under natural conditions. Regardless of growing conditions, the shortest cultivars in peak time were 'Sonata', 'Pennant II', and 'Brightstar II' and the longest one 'Revenge GLX'. Considering germinating vigor, early germination speed and germination peak time, 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' were regarded as excellent cultivars under ISTA conditions, while 'Pennant II' and 'Brightstar II' under natural conditions.