• The Korean Journal of Ecology
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• v.12 no.4
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• pp.219-236
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• 1989

The effect of salinity on the seed germination and seedling growth of Pinus densiflora for. erecta Uyeki were studied under the controlled conditions in the growth chamber. The seeds were sorted into three classes in weight such as large ($15.49\pm$1.63mg), medium($10.61\pm$1.38mg), and small ($6.57\pm$1.33mg) to determine the role of seed weight in germination and seedling growth of the pine. Polymorphic seeds of the pine were germinated an salinity range of 0 to 1.5% NaCl under various temperature ($10^{\circ}$ $-25^{\circ}$ with $5^{\circ}$C interval of constant temperature, and $10^{\circ}$ $-20^{\circ}$C, $15^{\circ}$ $-25^{\circ}$C of alternating temperature) in order to determine their germinability and seeding growth. In control plot, there was little difference of germination percentage among the seed weight classes, but in saline plot, the larger seeds generally had a higher percentage and rate of germination. There occurred synergistic interaction between salinity and temperature in the germination and the increase of temperature enhanced germination of seeds at the same salinity level. Alternating temperature regimes of $15^{\circ}$-$25^{\circ}$C yielded maximum germination and no germination was occurred at $10^{\circ}C$. The germination at alternating temperature showed higher germination percentage than at constant temperature. The percentage and of germination decreased drastically with increased salinity level to 1.00%; no germination was occurred at 1.50% salinity level. The growth fo sddelings from larger seeds was better than that of smaller seeds at the same salinity and temperature. The hypocotyl and radicle were more sensitive than cotyledon to the increased salinity stress.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.106-111
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• 2003

This study made an experiment On fatigue crack propagation da/dn, stress intensity factor range ${\Delta}K$ respectively in room temperature and in low temperature. And we got the following characteristics from fatigue crack growth test carried Out in the environment of room temperature and law temperature at $25^{\circ}C$, $-60^{\circ}C$, $-80^{\circ}C$, and $-100^{\circ}C$ in the range of stress ratio of 0.3 by means of opening made displacement. The threshold stress intensity factor range ${\Delta}Kth$ in the early stage of fatigue crack growth (Mode I) and stress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Made II) was decreased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at law temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.149-155
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• 2006

This study was carried out to investigate effects of different night temperature treatments during nursery period on flower bud differentiation and growth of pepper cv. Cheongyang. Number of leaves, top fresh weight and top dry weight of pepper seedlings were increased with increasing the night temperature during nursery periods. And also flower bud differentiation and days to flowering were accelerated as increasing the night temperature. Plant height, stem diameter, branch length and intermode length of pepper after transplanting were height at the low night temperature ($28/11^{\circ}C$), but they were retarded at the high night temperature ($28/21^{\circ}C$) treatment. Number of lateral branches was significantly reduced at the high night temperature, but there was no a regular tendency in branching habit of the main stem by temperature treatments. Seedling growth before transplanting was retarded at the low night temperature but gradually recovered after transplanting into the plastic house. However, seedling growth at the high night temperature was shown in contrast to above response of the low night temperature.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.264-274
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• 2020

Background: Climate change has altered the various ecosystem processes including forest ecosystem in Himalayan region. Although the high mountain natural forests including treelines in the Himalayan region are mainly reported to be temperature sensitive, the temperature-related water stress in an important growth-limiting factor for middle elevation mountains. And there are very few evidences on growth performance of planted forest in changing climate in the Himalayan region. A dendrochronological study was carried out to verify and record the impact of warming temperature tree growth by using the tree cores of Pinus roxburghii from Batase village of Dhulikhel in Central Nepal with sub-tropical climatic zone. For this total, 29 tree cores from 25 trees of P. roxburghii were measured and analyzed. Result: A 44-year long tree ring width chronology was constructed from the cores. The result showed that the radial growth of P. roxburghii was positively correlated with pre-monsoon (April) rainfall, although the correlation was not significant and negatively correlated with summer rainfall. The strongest negative correlation was found between radial growth and rainfall of June followed by the rainfall of January. Also, the radial growth showed significant positive correlation with that previous year August mean temperature and maximum temperature, and significant negative correlation between radial growth and maximum temperature (Tmax) of May and of spring season (March-May), indicating moisture as the key factor for radial growth. Despite the overall positive trend in the basal area increment (BAI), we have found the abrupt decline between 1995 and 2005 AD. Conclusion: The results indicated that chir pine planted population was moisture sensitive, and the negative impact of higher temperature during early growth season (March-May) was clearly seen on the radial growth. We emphasize that the forest would experience further moisture stress if the trend of warming temperatures continues. The unusual decreasing BAI trend might be associated with forest management processes including resin collection and other disturbances. Our results showed that the planted pine forest stand is sub-healthy due to major human intervention at times. Further exploration of growth climate response from different climatic zones and management regimes is important to improve our understanding on the growth performance of mid-hill pine forests in Nepal.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3415-3423
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• 1996

The compact tension specimen geometry has been widely used for measuring fatigue crack growth rates at elevated temperature when the fatigue load is under tension/tension condition. However, most of the elevated temperature components which have significant crack growth life experience fatigue load under tension/compression conditions. Thus test techniques are required since the compact tension specimen cannot be used for tension/compression loading. In this paper, a simplified test procedure for measureing fatigue crack growth rates is proposed, which employs a round bar specimen with a small surface crack. Fatigue crack growth rates under tension/ tension loading conditions at elevated temperature were measured according to the proposed procedure and compared with those previously measured by C/(T) specimens. Since both the measured crack growth rates were comparable, the fatigue crack growth rates under tension/ compression load can be reliably measured by the proposed procedure. For monitoring crack depth. DC electric potential method is employed and an optimal probe location and current input conditions were proposed.

• Korean Journal of Medicinal Crop Science
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• v.28 no.3
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• pp.221-228
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• 2020

Background: Angelica gigas Nakai, that belong to the Umbelliferae family, is one of the traditional medicinal plants in Korea. Its roots have been used to treat gynecological diseases. In this study, growth characteristics and index components were compared with the forest microclimate at several forest sites. Methods and Results: A. gigas was planted in three climatic zones according to the temperature (southern temperature zone - Hamyang, central temperature zone - Bonghwa, and northern temperature zone - Jeongseon) and growth characteristics were investigated in comparison with the forest microclimate. Our results indicated that the root diameter and length, and fresh and dry weight were the highest in Jeongseon. The total content of decursin was the highest in Jeongseon (9.52%), followed by those in Hamyang (8.07%) and Bonghwa (7.48%), respectively. Additionally, the yield of decursin (1.39 g) was the highest in Jeongseon. Conclusions: The yield and index components were influenced by the microclimate in the forests, and it was assumed that high altitude and low temperature affected the increase in growth and index components. These results will be useful as basic data to study the correlation among environmental conditions, growth, and index components.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.79-81
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• 1998

To investigate the influence of originated host and water temperature on the infectivity and growth of Microcotyle sebastis, juveniles of Schlegel's black rockfish (Sebastes schlegeli) were exposed to the eggs of M. sebastis originated from. Schlegel's black rockfish and black rockfish (Sebastes inermis) at $10^{\circ}C$ and $10^{\circ}C$. There were significant differences between the two isolates in the infectivity of eggs, and the growth of worms. The growth of M. sebastis was significantly affected by water temperature, and worms grew faster in $20^{\circ}C$ than in $10^{\circ}C$.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.3
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• pp.197-201
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• 1999

The growth of two phytoplanktons was studied in a natural environment and in the laboratory under artificial radiation conditions in the presence or absence of UV radiation. The effect of an elevated temperature on the two phytoplanktons was also examined. UV radiation resulted in a decrease in the growth of the two phytoplanktons ; P. micans was more affected by UV than S. costatum. Four hours of UV radiation decreased the motility of S. costatum and P. micans by 20% and 40%, respectively. Accordingly, an elevated temperature and UV radiation decreased the growth rate of the two phytoplanktons investigated.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.264-268
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• 2008

An assessment of creep-fatigue crack behavior is required to ensure the structural integrity for high temperature components such as fast breeder reactor structures or thermal power plant components operating at an elevated temperature. In this study, an evaluation of creep-fatigue crack growth has been carried out according to the French assessment guide of the RCC-MR A16 for austenitic stainless steel structures. The assessment procedures for creep-fatigue crack growth in the recent version of the A16 (2007 edition) have been changed considerably from the previous version (2002 edition) and the material properties (RCC-MR Appendix A3) have been changed as well. The impacts of those changes on creep-fatigue crack growth behavior are quantified from the assessments with a structural model. Finally the assessment results were compared with the observed images obtained from the structural tests of the same structural specimen.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.49-54
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• 2010

The aim of this research was to estimate the effect of temperature and develop predictive models for the growth of total viable cells (TVC) and Escherichia coli (EC) on chicken breast under aerobic and various temperature conditions. The primary models were determined by Baranyi model. The secondary models for the specific growth rate (SGR) and lag time (LT), as a function of storage temperature, were developed by the polynomial model. The initial contamination level of chicken breasts was around 4.3 Log CFU/g of TVC and 1.0 Log CFU/g of E. coli. During 216 h of storage, SGR of TVC showed 0.05, 0.15, and 0.54 Log CFU/g/h at 5, 15, and $25^{\circ}C$. Also, the growth tendency of EC was similar to those of TVC. As storage temperature increased, the values of SGR of microorganisms increased dramatically and the values of LT decreased inversely. The predicted growth models with experimental data were evaluated by $B_f$, $A_f$, RMSE, and $R^2$. These values indicated that these developed models were reliable to express the growth of TVC and EC on chicken breasts. The temperature changes of distribution and showcase in markets might affect the growth of microorganisms and spoilage of chicken breast mainly.