• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.703-708
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• 2014

This study was conducted to investigate effects of soil amendments on survival rate and growth of seedlings in a semi-arid region, Mongolia. 2-year-old Populus sibirica and Ulmus pumila seedlings were planted in alkaline sandy soils and treated with 2 levels of nitrogen, elemental sulfur, artificial moisture retention and converted loess. After 4 months, the seedling survival rate of both species decreased as the amount of nitrogen increased. Nitrogen has been generally known to increase seedling survival rate and growth by supplying nutrients, however, reduced survival rate in this study might be affected by consequential increase in soil osmotic pressure, which was caused by excessive nitrogen fertilization. The root collar diameter (RCD) growth of both species increased significantly by the treatment of converted loess, and only RCD growth of P. sibirica increased by the artificial moisture retention treatment. Although P. sibirica is drought-tolerant, it is in the group of Populus spp. which requires a high capacity of available water. Conversely, the elemental sulfur treatment showed no effect on survival rate and RCD growth for both species due to the low oxidation of sulfur in arid soils. The extended monitoring of seedling growth and soil characteristics is required to elucidate the long-term effects of soil amendments in the semi-arid region, and the further studies are also needed to examine the appropriate amount of fertilizers for both species.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.109-114
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• 1999

This study was carried out to obtain some information on the sustainability of paddy rice through the long-term variation of nitrogen use efficiency. The experiment was conducted during 30-year with the same amount of N, P, K and compost at Milyang, southern part of Korea. The results were as follows. Grain yield was increased significantly in the plots of compost incorporation only. However, yield productivity was decreased slightly in the plots with nil and unbalanced fertilization. The effects of rice straw compost on grain yield was not clear at the early crop years but was shown slightly at the late period of the experimental. The grain yield in the plots of compost incorporation at 30th crop year was come to about 80% of NPK plots. The amount of nitrogen uptaken by rice plant was the highest as $167kg\;ha^{-1}$ in NPK plus compost incorporation. Recovery efficiency)($RE_N$) was higher as 0.48~0.74 in compost incorporation plots than in other plots of balanced and unbalanced application. Average agronomic efficiency($AE-N$) and partial factor productivity from N fertilizer applied($PFP_N$) during 30 crop years in NPK plots was 12.8 kg/kg N and 37.7 kg/kg N, respectively, and difference of $AE-N$ and $PFP_N$ shown as indigenous soil nitrogen supply(INS) was higher as 28.4 kg/kg N in NPK + compost plot than NPK plot and was widened at the late period of experiment.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.249-255
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• 2023

Korean melon (Cucumis melo L.) is grown mostly in Northeast Asia area, and as a fruit mainly produced in Korea, the yield per unit area continues to improve, but the cultivation method is limited to soil cultivation, so it is necessary to develop hydroponic cultivation technology for scale and labor-saving is needed. As the ratio of NO₃^- increased, the plant height, the leaf length, the leaf width, and the internode length became longer and larger. On the other hand, the SPAD value decreased. The lower the ratio of NO₃^-, the faster the female flower bloom, and there was no difference in fruit maturity between treatments. There was no difference in the shape of fruit according to the ratio of NO₃^-, and the hardness was higher as the ratio of NO₃^- was lower. The total yield from March to July was KM3 5,650 kg/10a and KM1 4,439 kg/10a, 27% higher in KM3 and, in particular, 36% higher in quantity from March to May, when Korean melon prices were high season. Therefore, it was judged that it would be appropriate to supply NO₃^- suitable for hydroponic cultivation of Korean melon, which was formalized in December and produced from spring, at the level of 6.5 to 10 me·L^-1.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.4
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• pp.77-85
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• 2020

This study analyzes the effects of mixed fermented organic fertilizer on chinese cabbage growth and soil properties in order to investigate the nutritional effects of organic fertilizers, which are developed as an alternative fertilizer for imported castor oil cake. In this study, four treatments were set up: 100% and 200% rate of nitrogen application (320 kg ha-1 for Chinese cabbage) on mixed fermented organic fertilizer A(FA) and mixed fermented organic fertilizer B(FB), respectively, 100% rates of the mixed expeller cake (MEC) fertilizer, and the untreated control. Results revealed that the growth and yield of Chinese cabbage increased as more fermented organic fertilizer was used. However, while there were no significant differences in growth characteristics between treatments of 100% rate of mixed fermented organic fertilizer and 100% rate of MEC, the impacts on yields resulted similar. The nitrogen use efficiency (NUE) of Chinese cabbage was measured a range of 20-31% depending on the response to treatment. The 100% FA showed the same as NUE and nitrogen absorption with 100% rate of MEC. Regarding soil properties after cultivation, there were no significant differences among the effects of fertilizers in pH, EC, soil organic matter, and available phosphate. However, the content of exchangeable cations(K, Ca, Mg) was higher in areas treated with mixed fermented organic fertilizer than in untreated areas. Furthermore, the bacterial population density in the soil was higher in areas treated with mixed fermented organic fertilizer than in untreated areas and increased as more mixed fermented organic fertilizer was used. There were no significant differences in the population density of actinomycetes and fungi when fertilizer was applied to the soil. These results also show that FA, as a alternative organic fertilizer for imported castor oil cake, has similar nutritional effects as that of MEC. Therefore, further research the appropriate amounts of fertilizer is required to achieve economical and eco-friendly nutrient management.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.31-39
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• 2007

Monitoring data of 48 agricultural irrigation reservoirs from 1999 to 2004 was analyzed for water quality characteristics including biochemical oxygen demand $(BOD_5)$, chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and chl-${\alpha}$. Land uses of the watersheds associated with these reservoirs were determined for residential, forest, upland, paddy and miscellaneous, and regressed against water quality characteristics. Correlation analysis showed that forest land use was negatively correlated with all the water quality characteristics implying it's beneficial effects in water quality perspectives. Other land uses including residential, upland, and paddy generally illustrated positive correlation with water quality characteristics, which indicates most human activities of the watershed could degrade water quality of the receiving water bodies. Paddy land use partially contributed to the water quality degradation in contrast to the previous studies. It might be attributed to the relatively clean water quality of the study area, where even slight pollutant loading could degrade sensitively water quality. Further investigation is recommended for the effect of proximity as well as land use portions on the water quality of receiving water body.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.607-616
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• 2003

This study was conducted to determine the effect of feeding a total mixed ration(TMR) of broiler litter(BL) and bakery by-product(BB) with additional BL or rice straw incorporated at 10% of dietary DM as a roughage source on behavior pattern, nutrient intake, digestibility, digestible nutrient intake, ruminal and blood parameters, and N balance of sheep. All the treatment diets were formulated to be isoenergetic[total digestible nutrients(TDN) 66.9%]. Compared with the conventional formulated feed - rice straw feeding system(control), feeding TMR with BL(T1) or rice straw(T2) at 10% of dietary DM resulted in reduced eating, ruminating and total chewing time(P<0.05), similar DM intake, low(P<0.05) digestible DM, OM, fiber and total nutrients intake, low(P<0.05) nutrients digestibilities except EE, similar ruminal characteristics(pH, VFA concentrations and ratios, efficiency of carbohydrate fermentation, NH3-N), and favorable N digestion and retention. There were no differences in the above parameters between T1 and T2 with the exception of increased(P<0.05) eating, ruminating and total chewing time for T2. These results suggested that a TMR of BL and BB with or without rice straw may replace the conventional formulated feed and rice straw in ruminant diets successfully and furthermore feeding the TMR with rice straw made sheep behavior pattern more favorable.

• Journal of IKEEE
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• v.25 no.4
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• pp.782-785
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• 2021

In this paper, we propose a personalized cooling management system with thermal imaging camera. The proposed equipment uses a thermal imaging camera to control the amount of cold air and the system according to the difference between the user's skin temperature before and after the procedure. When the skin temperature is abnormally low, the cold air supply is cut off to prevent the possibility of a safety accident. It is economical by replacing the skin temperature sensor with a thermal imaging camera temperature measurement, and it can be visualized because the temperature can be checked with the thermal image. In addition, the proposed equipment improves the sensitivity of the sensor that measures the distance to the skin by calculating the focal length by using a dual laser pointer for the safety of a personalized cooling management system to which a thermal imaging camera is applied. In order to evaluate the performance of the proposed equipment, it was tested in an externally accredited testing institute. The first measured temperature range was -100℃~-160℃, indicating a wider temperature range than -150~-160℃(cryo generation/USA), which is the highest level currently used in the field. In addition, the error was measured to be ±3.2%~±3.5%, which showed better results than ±5%(CRYOTOP/China), which is the highest level currently used in the field. The second measured distance accuracy was measured as below ±4.0%, which was superior to ±5%(CRYOTOP/China), which is the highest level currently used in the field. Third, the nitrogen consumption was confirmed to be less than 0.15 L/min at the maximum, which was superior to the highest level of 6 L/min(POLAR BEAR/USA) currently used in the field. Therefore, it was determined that the performance of the personalized cooling management system applied with the thermal imaging camera proposed in this paper was excellent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.21-30
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• 1991

In Summer, oxygen-deficient water masses were developed extensively in the closed eutrophic bays such as Chinhae Bay which results in mass mortality of marine organisms and severe decrease the production of the bay every year. Under the circumstances, this study was performed to investigate the oxygen depletion relating to eutrophication, and also to evaluate self-purfication capacity of Buk Bay by dissolved oxygen mass balance in 1988. The mean concentration of total inorganic nitrogen, phosphate phosphorus and chlorophyll-a were $11.06{\mu}g-at/l,\;0.80{\mu}g-at/l\;and\;1.11mg/m^3$ respectively, which were over eutrophication criteria. Oxygen-deficient water mass was formed in July with the minimum concentration of 2.08ml/l(mean) at the bottom of all stations and recovered slowly in August. The decay and reaeration coefficient calculated from dissloved oxygen sag curve were 0.222/day and 0.018ml/l/day, respectively. To maintain above 4ml/l of oxygen to prevent oxygen-deficient water mass, it is recommendable to supply as much as 0.856ml/l/day of dissolved oxygen or should be reduced the same mass loading of BOD from watershed by the construction of wastewater treatment plant.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.34-48
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• 1982

1. Production and consumption of chemical fertilizers in Korea could be divided into five different phases of total imports, setting up fertilizer plants, self-sufficiency in production, net export, and diversification in compound fertilizers. Currently the nation has production capacity of 800 thousand M/T of nitrogen, 400 thousand M/T of phosphate ($P_2O_5$) and 200 thousand M/T of potash ($K_2O$). 2. Yearly consumption increased every year, since 1964, 28,000 M/T N, 7,700 M/T $P_2O_5$, and 7,500 M/T $K_2O$ until 1972, when the increase jumped by eight times for $P_2O_5$ and seven times for $K_2O$ for the following 3 years in anticipation of their short supply. Now total consumption has been more or less stabilized at the level of 450 thousand M/T N, 220 thousand M/T $P_2O_5$ and 180 thousand M/T $K_2O$ for the last 7 years. 3. Current operation rate of fertilizer plants is around 80% throughout the whole industry, after going through several different levels depending on demand at times. 4. Fertilizer export started in 1967 and reached a peak of 150 thousand nutrient ton in 1972, about 20% of total production, before temporarily stopping due to over-demand for next three years. The export resumed again in 1976 rise to the all time high of 670 thousand nutrient ton in 1980, almost half of total production, and then started to decline due to higher price of petroleum since then. 5. The decline in fertilizer export appears to be accelerated because several countries, in South-Eastern Asia, traditional export market for Korean fertilizers, started to build their own plants, since 1980, based on their raw materials of especially petroleum. 6. Current consumption in Korea is about 30 nutrient Kg per 10a, equivalent to that in Western European countries, partly due to new high-yielding rice varieties and extensive cultivation of fruit trees and vegetables. Additional fertilizer demand in future can be anticipated in reclaimed land for growing grass and forestry.

• Korean Journal of Microbiology
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• v.18 no.1
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• pp.20-28
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• 1980

Thirty species of wild yeasts were ioslated and identified from two hundred strains collected from flowers by enrichment techniques using steptomycin. Among them, twnety three species could assimilate methanol and three species, Candida incommunis, cryptococcus aerius and Hansenula ciferrii which showed good biomass yield were selected. These three species assimilated methanol as carbon and energy source without mixture of vitamin and yeast extract. The species grown on methanol media were confirmed to have all essential amino acids in their cellular constituents. The content of total amino acids are as followings ; Candida incommunis : 42.5%, Hansenula ciferrii : 39.9%. Of the essential amino acids lysine and threonine which are usually lacking in grain protein were as much as flour's. The experiments on the growth conditions for the higher biomass yield showed the result that the optimum concentration of methanol ans temeprature wre defined as 1.3% and $30^{\circ}C$ in each species.