• International Journal of Railway
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• 제5권3호
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• pp.129-134
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• 2012

Contact fatigue damages on the rail surface, such as head checks and squats are a growing problem. The fatigue cracks forming on the contact surface grow according to load and lubricating conditions and may end up breaking the rail. Rail fracture can be avoided by preventing the cracks from reaching the critical length. Therefore, the crack growth rate needs to be estimated precisely according to the conditions of the track and load to develop a maintenance plan against rail damages. Therefore, it is important to understand the mechanism of cracks initiation and growth on a rail due to repetitive rolling contact. In this study, we have investigated the crack growth behavior on the rail surface by using the twin-disc tests and the finite element analysis.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.317-320
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• 2000

The optimal temperature and pH for both mycelial growth and exe-biopolymer production by Cordyceps millitaris in shake flask culture were found to be $20^{\circ}C$ and 6.0, respectively. Sucrose (4%) and corn steep powder (1%) were the most suitable carbon and nitrogen source for mycelial growth and exo-biopolymer production. The maximum specific growth rate $(0.142h^{-1})$ was achieved when sucrose was used as the sole carbon source. Exo-biopolymer production was increased with the increase in C/N molar ratio concentration, probably due to the facilitated carbon uptake. Under the optimal culture conditions, the maximum mycelial growth exe-biopolymer concentration were reached to around 13.3 g dry cell weigh/l and 3.33 g/l, respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.413-416
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• 2000

Panax ginseng hairy roots, transformed by Agrobacterium rhizogenes KTCT 2744, was incubated flask, and investigated its optimal growth conditions. Transformed P. ginseng hairy roots showed active branching pattern and fast growth at free-hormone medium. Optimal conditions of hairy roots showed maximum growth at $23^{\circ}C$, pH 5.8, 1/2 MS medium, 3% sucrose. Effects of combined sugar showed that it had a better growth at only sucrose without glucose or fructose than with glucose or fructose. Also the case of sucrose with glucose had a better growth than with fructose.

• 한국세라믹학회지
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• 제29권3호
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• pp.189-194
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• 1992

In order to grow a 127.86$^{\circ}$rotated LiNbO3 single crystal with good characteristics of surface acoustic wave (SAW) up to 80 mm in diameter, the temperature gradient of furnace, the growth rate and the rotation rate of crystal were changed. We could grow a crystal which had few macro defects at the conditions of temperature gradient as 30~6$0^{\circ}C$/cm, growth rate as 5 mm/hr and rotation rate as 8 rpm. The experimental ranges of the growth conditions are as follows. Temperature gradient was varied from 20 to 20$0^{\circ}C$/cm, growth rate as 5~7 mm/hr and crystal rotation rate as 6~12rpm.

• 한국버섯학회지
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• 제14권1호
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• pp.6-13
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• 2016

This study was carried out to determine the basic mycelial culture conditions for Poria cocos growth. According to colony diameter and mycelial density, suitable media for mycelial growth were Malt yeast extract, Potato dextrose agar, Yeast extract agar, and Yeast malt agar. The optimum temperature for mycelial growth was between 25 and $35^{\circ}C$, and the optimum pH value was between 4 and 7. Carbon and nitrogen sources were fructose and yeast extract. The optimum C/N ratio was about 10 to 1 with 2% glucose. Other minor components for optimal growth were thiamine-HCl and nicotinamide as vitamins, acetic and lactic acid as organic acids, and $MgSO_4{\cdot}7H_2O$ and $FeSO_4{\cdot}7H_2O$ as mineral salts.

• 대한원격탐사학회지
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• 제31권1호
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• pp.11-20
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• 2015

This study aimed to investigate the canopy growth conditions and the accuracy of phenological stages of paddy rice using ground-based remote sensing data. Plant growth variables including Leaf Area Index (LAI) and canopy reflectance of paddy rice were measured at the experimental fields of Chonnam National University, Gwangju, Republic of Korea during the crop seasons of 2011, 2012, and 2013. LAI values were also determined based on correlations with Vegetation Indices (VIs) obtained from the canopy reflectance. Three phenological stages (tillering, booting, and grain filling) of paddy rice could be identified using VIs and a spatial index (NIR versus red). We found that exponential relationships could be applied between LAI and the VIs of interest. This information, as well as the relationships between LAI and VIs obtained in the present study, could be used to estimate and monitor the relative growth and development of rice canopies during the growing season.

• 미생물학회지
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• 제16권3호
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• pp.131-139
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• 1978

Mycoplasma pneumoniae was examined for growth characteristics and morphology when cultivated in several media supplemented with a variety of sera and under different atmospheric conditions. different formula of the medium as well as different sources of lot numbers of the serum in the same medium exhibited varying effects on growth rate and adherence. When the organisms were cultivated in SSR-2 medium in a normal atmospheric environment or under a facultative anaerobic condition provided with carbon dioxide, they developed filamentous cells with heavy growth, whereas mainly round-shaped cells were produced under strict anaerobic conditions of hydrogen and carbon dioxide. Both morphologies of the organism were transformed by switching the incubation environments. An inverted phasecontrast microscopy using modified petri dishes was excellent to observe single cells and useful to follow the development of the cells. Growth, turbidity, and pneumoniae colonies developed on a solid medium and produced clear when overlaid with sheep blood agar.

• 한국환경과학회지
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• 제33권6호
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• pp.383-402
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• 2024

Variations in lettuce growth and quality were observed depending on the type of artificial light source. The RGB LED treatment resulted in thick leaf development, leading to higher fresh weight, dry weight, and relative growth rates. Two cultivars, "Tomalin" and "seonpunggold," exhibited increased anthocyanin content and dark red leaf color under conditions of RGB LED treatment. Additionally, they exhibited high chlorophyll content under conditions of RGB LED and RGBFR LED treatments. Particularly, under Red LED treatment, the plants showed elongated leaves with narrow widths, resulting in a higher leaf shape index and a tendency towards leaf curling. Therefore, RGB LED lighting which appropriately blends red, blue, and green lights, is more effective than single lighr sources at improving lettuce growth and quality.

• 한국수산과학회지
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• 제48권5호
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• pp.704-711
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• 2015

We examined the effects of temperature and light intensity on gametophyte growth of Ecklonia cava Kjellman. The growth of female and male gametophytes was investigated before maturation. Gametophytes prepared from Munseom, Jeju, Korea in October 2014 were separated by sex and maintained under the following conditions: 15℃, 20 μmol·m^-2·s^-1, and a 12-h/12-h light/dark cycle. The experiments were conducted at five temperatures (10, 15, 20, 25, and 30℃) and three light intensities (5, 20, and 40 μmol·m^-2·s^-1). Daily growth rates were estimated by the increase in filamentous frond area. The optimal growth conditions for female gametophytes were 20℃ and 40 μmol·m^-2·s^-1; the optimal conditions for male gametophytes were 15℃ and 20 μmol·m^-2·s^-1. The relative growth rates (RGR) of female and male gametophytes decreased at 25℃ and 30℃, respectively. At 30℃, RGRs of gametophytes decreased by approximately 1.0% day^-1. In addition, RGRs of male gametophytes were higher than those of female gametophytes. These results indicate that female gametophytes were more sensitive to temperature and light intensity than male gametophytes. Moreover, these results suggest that E. cava growth rates could decrease as a result of global warming.

• 한국수산과학회지
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• 제50권2호
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.