• Journal of the Korean Magnetics Society
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• v.19 no.3
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• pp.89-93
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• 2009

Amorphous $Ge_{1-x}Mn_x$ semiconductor thin films grown by low temperature vapor deposition were annealed, and their electrical and magnetic properties have been studied. The amorphous thin films were $1,000{\sim}5,000\;{\AA}$ thick. Amorphous $Ge_{1-x}Mn_x$ thin films were annealed at $300^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$ and $700^{\circ}C$ for 3 minutes in high vacuum chamber. X-ray diffraction analysis reveals that as-grown $Ge_{1-x}Mn_x$ semiconductor thin films are amorphous and are crystallized by annealing. Crystallization temperature of amorphous $Ge_{1-x}Mn_x$ semiconductor thin films varies with Mn concentration. Amorphous $Ge_{1-x}Mn_x$ thin films have p-type carriers and the carrier type is not changed during annealing, but the electrical resistivity increases with annealing temperature. Magnetization characteristics show that the as-grown amorphous $Ge_{1-x}Mn_x$ thin films are ferromagnetic and the Curie temperatures are around 130 K. Curie temperature and saturation magnetization of annealed $Ge_{1-x}Mn_x$ thin films increase with annealing temperature. Magnetization behavior and X-ray analysis implies that formation of ferromagnetic $Ge_3Mn_5$ phase causes the change of magnetic and electrical properties of annealed $Ge_{1-x}Mn_x$ thin films.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.359-364
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• 2008

We have investigated optical and structural properties of $Al_{0.3}Ga_{0.7}N$/GaN and $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ heterostructures (HSs) grown by metal-organic chemical vapor deposition, by means of Hall measurement, high-resolution X-ray diffraction, and temperature- and excitation power-dependent photoluminescence (PL) spectroscopy. A strong GaN band edge emission and its longitudinal optical phonon replicas were observed for all the samples. At 10 K, a 2DEG-related PL peak located at ${\sim}\;3.445\;eV$ was observed for $Al_{0.3}Ga_{0.7}N$/GaN HS, while two 2DEG peaks at ${\sim}\;3.42$ and ${\sim}\;3.445\;eV$ were observed for $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS due to the additional $Al_{0.15}Ga_{0.85}N$ layers. Moreover, the emission intensity of the 2DEG peak was higher in $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS than in $Al_{0.3}Ga_{0.7}N$/GaN HS probably due to an effective confinement of the photo-excited holes by the additional $Al_{0.15}Ga_{0.85}N$ layers. The 2DEG-related emission intensity decreased with increasing temperature and disappeared at temperatures above 150 K. To investigate the origin of the new 2DEG peaks, the energy-band structure for multiple AlGaN/GaN HSs were simulated and compared with the experimental data. As a result, the observed high- and low-energy peaks of 2DEG can be attributed to the spatially-separated 2DEG emissions formed at different AlGaN/GaN heterointerfaces.

• Journal of the Korean earth science society
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• v.39 no.5
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• pp.419-435
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• 2018

The purpose of this study is to understand meteorological and climatological factors that have influence on the garlic product in Seosan and Taean, and to analyze the economic value according to the use of climatical information data for garlic farmers. The climatological characteristics and trends in this area are analyzed using the meteorological data at the Seosan local meteorological agency from 1984 to 2013, the national statistical data for the product of garlic from 1989 to 2013, and the scenario data for climate change (RCP 4.5 and 8.5) for the period from 2001 to 2100. The results are as follows. First, the condition of lower temperature for garlic growth in winter season is satisfied with the mean air temperature. The wind speed are lower and stronger in Seosan and Taean than other garlic area. The suitable condition for the growth of northern type of garlic shows the decreasing trend in the accumulated precipitation in May. However, the area of growing the northern type garlic in the future is likely diminished because mean air temperature, accumulated precipitation, and mean wind speed are strong in the harvest time of garlic. Second, the seedtime of the northern and southern type of garlic using climate change scenarios (RCP 4.5, 8.5) in Seosan and Taean is getting late as time passes. and the harvest time gets faster, which indicates s that the period of garlic cultivation becomes shorter from 50 days to around 90 in the next 100 years. Third, the beginning days of white rot and delia platura of garlic are estimated by applying to the meteorological algorithm using mean air temperature and soil humidity. Especially, the beginning day of white rot garlic is shown to be faster according to the scenarios of RCP 4.5 and RCP 8.5. Fourth, the product of garlic (kg/10a) shows a high correlation with the minimum air temperature of a wintering time, the mean wind speed of a wintering time, the accumulated precipitation of a corpulent time, and the mean relative humidity of corpulent time of garlic. On the other hand, the analysis of garlic product when using the meteorological information data in cultivating garlic in Seosan and Taean reveals that the economic value increases up to 9% in total.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1658-1672
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• 2016

This study aimed to investigate preferences for sous-vide cooked jabchae between Korean and Chinese consumers according to sauce mixing proportion. To commercialize sous-vide cooked jabchae and localize it for overseas circumstances in the Korean and Chinese markets, consumers' subjective preferences for sous-vide cooked jabchae were investigated especially in 119 Korean consumers (55 males and 64 females) and 136 Chinese consumers (70 males and 66 females). For jabchae samples, this study set up three different mixture rates of soy sauce and sugar, 8% (LSS), 13% (MSS), and 18% (HSS), and three different salad oil rates, 0% (LO), 12% (MO), and 24% (HO), to propose nine kinds of samples. As a result of consumer preferences, for Koreans, MSS and HSS regardless of oil content were significantly high in overall, appearance, saltiness, sweetness preferences, and purchase intention (P<0.001). In addition, for oiliness preference, LSS, MSS, LO, and MO were significantly high (P<0.001). For Chinese, HSS, MO, and HO were significantly high in overall, flavor preference, and purchase intention (P<0.001). For saltiness and sweetness preference, regardless of oil content, saltiness preference was significantly high in HSS and sweetness in MSS and HSS (P<0.001). For oiliness preference, regardless of content of soy sauce and sugar mixture, LO and MO were significantly higher, and for appearance preference, there was no significant difference among all samples (P<0.01). In general, both Korean and Chinese tended to prefer MS and HO, irrespective of oil content. Especially for Koreans, LSS was the least favorite sample in almost all preference questionnaires. For Chinese, preference scores for LSS and HSS were higher than for Koreans. On the other hand, oil content did not have much effect on consumer preference as compared with contents of soy sauce and sugar mixture.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.3
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• pp.141-150
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• 2024

Garlic (Allium sativum L.) is considered as one of the most important vegetables with various uses throughout the many countries. Also, it is one of the most economically important Allium species, and has been widely cultivated for more than 5,000 years. In Korea, garlic is planted in late summer and is grown from autumn and spring of the next year. Bulb starts to form when temperature rises under longer photoperiods. Garlic growth is affected by various factors such as storage conditions, humidity, duration of minimum temperature, and photoperiod. Also, the storage conditions for propagation seed are known to potentially affect future vegetative stages. In this study, we evaluated to effect of the inter-bud growth and growth of the southern-type cultivar 'Namdo' according to storage temperatures. The inter-bud growth, emergence & sprouting rate, and initial growth of stored garlic at low temperatures (5~15℃) exhibited robust growth, while garlic stored at high temperatures (30℃) was investigated to be sluggish compared to another treatments. However, the bulb diameter of stored garlic at 10 ℃ and 15℃ increased to 148.7% and 154.0 % compared to untreated garlic, respectively. Also, the bulb weight of stored garlic increased to 285.7% and 294.4% compared to control, respectively. In contrast, garlic stored at 5℃ showed a decrease of 70 .5% in bulb dimeter and 70 .6% in bulb weight compared to the control. As a results, it was confirmed that the storage temperature of garlic affects the inter-bud growth, emergence & sprouting rate, growth, bulb diameter, and bulb weight. These results will be to the possibility that is possible to estimate the growth cycle of garlic using the growth index for the improvement of crop modeling.