• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.79-85
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• 2007

Rice bran application just after transplanting has been increasingly practiced as an herbicide-substitute for organic rice production in Korea. However, this practice is frequently reported to be unsatisfactory in weed suppression. An experiment with five treatments that combines flooding depth, rice bran application dose, and herbicide treatment was done in the paddy field to evaluate whether rice bran application under deep flooding can lead to a successful weed control in compensation for the single practice of rice bran application. Rice bran was broadcasted on the flood water surface just after deep flooding of 8 to 10cm that was started at seven days after transplanting. In the shallow flooding plot without herbicide six weed species were recorded: Monochoria vaginalis, Echinochloa crus-galli, Ludvigia prostrate, Cyperus amuricus, Aneima keisak, and Bidens tripartite. Among the first four dominant weed species, deep flooding significantly suppressed the occurrence of Echinochloa crus-galli and Cyperus amuricus while did not suppress the occurrence of Monochoria vaginalis and Ludwigia prostrate. On the contrary, rice bran application under deep flooding suppressed significantly Monochoria vaginalis and Ludwigia prostrate while didn't exert an additional suppression of Echinochloa crus-galli and Cyperus amuricus compared to deep flooding alone. Rice bran application and deep flooding suppressed complimentarily all the six weed species to a satisfactory extent except for Monochoria vaginalis of which suppression efficacy was 31.9%. Deep flooding reduced the panicle number substantially by inhibiting the tiller production, increased the spikelet number per panicle slightly, and leaded to a lower rice grain yield compared to shallow flooding with herbicide. Rice bran application under deep flooding mitigated the panicle reduction due to deep flooding, increased the spikelets per panicle significantly, and thus produced even higher grain yield in the rice bran application of 2000kg $ha^{-1}$ as compared to the shallow flooding treatment with herbicide. In conclusion, this practice applying rice bran under deep flooding would be promising to be incorporated as an integral practice for an organic rice farming system.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.151-163
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• 2022

This study was conducted to promote organic fertilizer(s) that sustain soil productivity for corn production and protect the environment as required by the Act on the promotion of eco-friendly agriculture. It was conducted at the research station of the Organic Agriculture Division of the National Institute of Agricultural. The treatments consisted of Compost (Com), Bokashi as fermented organic fertilizer (FOF), and mixed expeller pressed cake (PC). They were applied at 174 kg N /ha to field corn, together with a 'no fertilizer' check in Randomized Complete Block Design. At eight weeks after transplanting (WAT) corn, compost increased soil carbon (C) and nitrogen (N) to 7.48 and 0.76 g/kg respectively, while other fertilizers maintained the initial levels (before treatment application). At corn harvest (13 WAT), soil chemical properties (total C, total N, pH, electrical conductivity, P₂O₅, Ca, K, and Mg) were similar among all organic fertilizer treatments. For soil respiration, FOF increased soil CO₂ respiration by 31-76% above other fertilizer treatments. However, there were no prominent changes in the trends of CH₄ fluxes following the two mechanical weeding operations. Fermented organic fertilizer affected N₂O emissions between 87-96% lower than other fertilizer treatments. Compared to the initial microbial densities, FOF increased fungi and actinomycete colony foming unit by 25 and 16% at harvest. Therefore, the additional potential of improving soil biological fertility and local availability of raw materials make FOF a better option to sustain soil productivity while protecting the environment.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.2
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• pp.200-208
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• 2014

This paper presents thermodynamic performance analysis of organic Rankine cycle (ORC) using low temperature heat source in the form of sensible energy and using liquefied natural gas (LNG) as heat sink to recover the cryogenic energy of LNG. LNG is able to condense the working fluid at a very low condensing temperature in a heat exchanger, which leads to an increased power output. Based on the mathematical model, a parametric analysis is conducted to examine the effects of eight different working fluids, the turbine inlet pressure and the condensation temperature on the system performance. The results indicate that the thermodynamic performance of ORC such as net work production or thermal efficiency can be significantly improved by the LNG cold energy.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.422-431
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• 2017

The biogeochemical information of riverine organic matter gives a detailed and integrated recording of natural and anthropogenic activity within a watershed. To investigate the changes in quality and quantity of organic carbon transporting from mountain to ocean via river channels, we estimated the concentrations of dissolved (DOC) and particulate organic carbon (POC), and then traced the source origin of POC using stable carbon isotopes ratio before and after summer rainfalls in the Tamjin River and Ganjin Bay, Korea. Along the small watershed, a total of 13 sites including headwaters, dam reservoir, river and estuary were established for the study. We found some interesting findings in the aspect of distribution of DOC/POC concentration changing their origin sources dynamically flowing downstream. In particular, the river channel transport downstream mainly DOC to river mouth, although upper dam reservoir increased POC concentration by phytoplankton production in summer. Whereas, in the river mouth and estuary, POC was dominated not only by local supply from nearby reed saltmarsh, but also by marine phytoplankton production, respectively. The findings can contribute to increasing the understanding of riverine organic carbon transport in upper large dam and lower open estuary system.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.87-90
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• 2007

VIATRON TECHNOLOGIES has developed an $\underline{A}$tmospheric $\underline{M}$etal $\underline{D}$oping (AMD) system which uniformly dopes metal species onto a substrate. The AMD system injects metal-organic vapor over substrate using an injection head with a scan motion. One of important application of this system is a metalinduced crystallization of amorphous Si for manufacturing AMOLED poly-Si panels. The AMD system with a use of Ni vapor source produces doping of trace amount of Ni onto amorphous Si, enabling uniform MIC crystallization. Also, the operation without vacuum condition offers advantages such as easy maintenance, low cost production, and large glass processes.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.71-76
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• 2014

The Netherlands produce more than 11 million tonnes of milk per year, and approximately 60% of the milk is exported. Dutch milk production is five times higher than that of Korea, even though Korea comprises a land area three times greater than the Netherlands. Upscaling and intensification have characterized the Dutch way of dairy farming since 1960, and adverse effects of the intensification of dairy farming became evident from the late 1970s and early 1980s onwards. The transition toward a more sustainable farming system is a central element of the Dutch agenda for the reconstruction of the livestock production sector. The environmental problems in Dutch dairy farming in the 1980s have led to the establishment of the experimental dairy farm "De Marke" which aims at improving the utilization of fertilizers and feeds, through minimizing nutrient requirements, maximizing the use of nutrients in organic manure and homegrown feeds, and through the targeted use of fertilizers and feeds. 85 cows at "De Marke" produce 720 tonnes of milk per year, using 55 ha of pasture in a sustainable manner. That means, 150,000 ha of pasture are required to produce 2 million tonnes of milk, which the current milk production of Korea. It is urgent to provide sufficient pasture for sustainable milk production in Korea, and primarily the transition to pasture of surplus rice paddies, resulting from of a decrease in rice consumption, should be considered.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.607-615
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• 2022

In this study, economic analysis program was developed for economic evaluation of hydrogen production, storage/delivery, and utilization technologies as well as overseas import of hydrogen. Economic analysis program can be used for the estimation of the levelized cost of hydrogen for hydrogen supply chain technologies. This program include five hydrogen production technology on steam methane reforming and water electrolysis, two hydrogen storage technologies (high compressed gas and liquid hydrogen storage), three hydrogen delivery technologies (compressed gas delivery using tube trailer, liquid hydrogen, and pipeline transportation) and six hydrogen utilization technologies on hydrogen refueling station and stationary fuel cell system. In the case of overseas import hydrogen, it was considered to be imported from five countries (Austraila, Chile, India, Morocco, and UAE), and the transportation methods was based on liquid hydrogen, ammonia, and liquid organic hydrogen carrier. Economic analysis program that was developed in this study can be expected to utilize for planning a detailed implementation methods and hydrogen supply strategies for the hydrogen economy road map of government.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.919-926
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• 2022

Fertigation, which has been introduced in agricultural fields since 1990, has been widely practiced in upland fields as well as in plastic film houses as part of the crop production system. In accordance with demands in the agricultural sector, a huge number of scientific studies on fertigation have been conducted worldwide. Moreover, with a combination of advanced technologies such as big-data, machine learning, etc., fertigation is positioned as an indispensable tool to achieve sustainable crop production and to enhance nutrient and water use efficiency. In this review, we focused on providing valuable information in terms of crop production and nutrient/water use efficiency. A variety of fertigation studies have described that enhancement of crop production did not differ relative to conventional method or slightly increased. In contrast, fertigation significantly improved nutrient/water use efficiency, with a reduction in use ranging from 20 to 50%. Water-soluble organic resources such as livestock manure and agricultural byproducts also have been identified as useful resources like chemical fertilizers. Furthermore, the initial irrigation point was generally recommended in a range of -10 - -40 kPa, although the point differed according to the crop and crop growth stage. From this review, we suggest that fertigation, which is closely integrated with advanced technology, could be a leading technology to attain not only food security but also carbon neutrality via improvement of nutrient/water use efficiency.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.373-384
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• 2011

This experiment was conducted to investigate the selection of regional double cropping system for production of organic forage in middle part of Korea and investigated their productivity, feed values and stock carrying capacity. The test results proved the Sorghum${\times}$Sudangrass hybrid was 10.9 $ton{\cdot}ha^{-1}$, the one of Rye + Red clover and Rye + Hairy vetch were the highest one as 3.3 $ton{\cdot}ha^{-1}$ and the relative yield about a Rye is higher in the dry matter yield in the field soil. And as for the relative forage values (RFV), Corn is the most excellent ones as 96.6 but there were no the significant difference between the Sorghum${\times}$Sudangrass hybrid of 84.4 and it. The total digestible nutrient (TDN) content in Rye + Hairy vetch is higher than others as 59.7%. As for the relative feed value, Rye + Red clover is the highest one as 83.8 but there was no significant differences between them. As for the ability to raise livestock in the field soil, the average values of $K_{CP}$ and $K_{TDN}$ are shown as 4.27 head/ha/yr in Sorghum${\times}$Sudangrass hybrid. As for the same crops, the average values of $K_{CP}$ and $K_{TDN}$ showed the highest ones as 1.74 head/ha/yr, in Rye + Red clover but there were no the significant differences. As for the dry matter yield of the rice field soil, organic rice straw was 3.3 $ton{\cdot}ha^{-1}$ and Rye + Red clover significantly showed the highest values as 4.1 $ton{\cdot}ha^{-1}$. In the rice filed soil, the crude protein content of organic rice straw was 3.1% and the TDN content of organic rice straw was 55%. The TDN content in Rye + Red clover was higher than others as 59.7%. As for the relative forage values, Rye + Red clover showed the highest one as 83.8 but there were no significant differences between them. As for the ability to raise livestock in the rice field, the average values of $K_{CP}$ and $K_{TDN}$ in the organic rice straw was 1.04 head/ha/yr and the average values of $K_{CP}$ and $K_{TDN}$ in Rye + Red clover is the highest one as 1.84 head/ha/yr, but there were no significant differences in all of them.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.488-494
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• 1993

A photosynthetic bacterium strain P17 having high growth rate and assimilating ability of organic acids was isolated from several soil samples, which was identified as Rhodospirillum rubrum. Cultural conditions of the strain P17 were examined for the production of starter culture used in the treatment of organic waste water. The addition of organic acids mixture as carbon source containing 0.2% Na-acetate, 0.1% Na-propionate and 0.2% Na-lactate and 0.1% of yeast extract as growth factor stimulated the cell growth. The maximal cell production was obtained at $30^{\circ}C$, pH 7.0, 2,500 lux of illumination and $50{\sim}100\;rpm$ of agitation. Under the optimal conditions of batch and fed-batch culture systems in a Jar fermentor, 5.17 g/l and 7.93 g/l of cells were obtained after S days of cultivation, respectively. In continuous culture system, the cell productivity was 0.206 g/l/h at a dilution rate of 0.21 $h^{-1}$. When R. rubrum P17 was cultivated in a soybean curd waste water, initial COD level(3,240 mg/l) of the waste water was reduced to 250 mg/l after 4 days of cultivation.