• Journal of IKEEE
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• v.23 no.2
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• pp.487-494
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• 2019

In this paper, we designed IOT(Internet of Things) based hydroponic plant factory in order to avoid the effects of fine dust penetrating into the soil, and proposed the PLC(Programmable Logic Controller) control methods. The designed plant factory could monitor the density of oxygen, the density of nutrient solution, temperature and humidity through touch screen and smart phone, and control the heater and cooler, ventilation and dehumidifier, and wavelengths of LEDs to grow plant in appropriate environments.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.57-64
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• 2016

Soybean sprouts have been a considered a nutrient-rich vegetable for hundreds of years. To evaluate the seedlot quality of soybean sprouts grown, and to evaluate a method for reducing the presence of improper seeds in soybean seedlots, microbes associated with soybean sprout rot were isolated from samples collected. Morphological characteristics and gas chromatography profiles of the cultured fungal and bacterial strains were identified. Eight types of improper seeds were identified: purple stain(Ps), black rot(Br), seed coat black spot(Cb), wrinkled seed(Ws), brown hilum(Bh), seed coat fracture(Cf), unripe seed(Us), and brown seed coat(Bc). The improper seeds were also dipped into 15%, 20%, and 25% NaCl solutions, as well as a saturated solution of NaCl, for 1min. As the NaCl concentration increased, the number of floating improper seeds increased as well. The highest floating rates were observed for the Cf seeds.

• Kyungpook Mathematical Journal
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• v.63 no.2
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• pp.141-154
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• 2023

We study the stability of traveling waves of a certain chemotaxis model. The traveling wave solution is a central object of study in a chemotaxis model. Kim et al. [8] introduced a model on a population and nutrient densities based on a nonlinear diffusion law. They proved the existence of traveling waves for the one dimensional Cauchy problem. Existence theory for traveling waves is typically followed by stability analysis because any traveling waves that are not robust against a small perturbation would have little physical significance. We conduct a numerical nonlinear stability for a few relevant instances of traveling waves shown to exist in [8]. Results against absolute additive noises and relative additive noises are presented.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.323-332
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• 2024

Circulating hydroponic cultivation has the advantage of reducing soil and water pollution problems caused by discharge of fertilizer components because the nutrient solution is reused. However, cyclic hydroponic cultivation has a low biological buffering capacity and can cause outbreaks of infectious root pathogens. Therefore, it is necessary to develop technologies or disinfection systems to control them. This study used dielectric barrier discharge plasma, which generates various persistent oxidants, to treat Fusarium oxysporum f. sp., a pathogen that causes wilt disease. Batch and intermittent continuous inactivation experiments were conducted, and the results showed that the total residual oxidant was persistent in intermittent plasma treatment at intervals of 2-3 days, and F. oxysporum was treated efficiently. Intermittent plasma treatment did not inhibit the growth of tomatoes.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.185-190
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• 2022

BACKGROUND: Most of the bottom ash(BA) from wood pellet-based thermal power plants that is not recycled is placed into landfill. BA has a function and structure similar to biochar. Hence, BA is classified as waste, but, it is predicted that BA can be used agricultural utilization. METHODS AND RESULTS: To investigate the effect of BA application on lettuce, growth characteristics and Pb contents were examined with BA application levels(0, 1, 2, 3 and 4 g/L), respectively, in hydroponic cultivation with Pb solution. Irrespective with BA application levels, the length, leaf number and fresh weight of lettuce in BA treatments were increased by 84.3~120, 36.2~39.0, and 215~322%, respectively, compared to the BA-0 treatment. The groups with BA treatments, Pb in the nutrient solution was adsorbed to the BA due to the surface area and functional groups of the BA, and the lettuce growth was maintained more smoothly than in the BA-0 treatment. BA application is considered to have created a favorable environment for lettuce growth in hydroponic cultivation with Pb solution. CONCLUSION(S): Although direct comparing the removal effect of heavy metal between BA and biochar is not present, the BA application in contaminated area suggested a significant meaning on the recycling waste, and increasing potential crop productivity by immobilizing heavy metal.

• Journal of Convergence Korean Medicine
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• v.2 no.1
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• pp.5-12
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• 2021

Objectives: The purpose of this study is to fabricate an ultra-fine ginsenoside particle atomizer that can provide a new treatment method by delivering ginsenoside components that have a therapeutic effect on respiratory diseases directly to the lungs. Methods: We fabricated the AAO vibrating mesh by using the micromachining process. The starting substrate of an AAO wafer has a 350nm pore diameter with 50㎛ thickness. A photomask having several 5㎛ opening holes with a 100㎛ pitch was used to separate each nanopore nozzle. The photoresist structure was optimized to pattern the nozzle area during the lift-off process precisely. The commercial vibrating mesh was removed from OMRON's NE-U100 product, and the fabricated AAO vibrating mesh was installed. A diluted sample of 20mL with 30% red ginseng concentrate was prepared to atomize from the device. Results: As a result of liquid chromatography analysis before spraying the ginsenoside solution, ginsenoside components such as 20S-Rg3, 20R-Rg3, and Rg5 were detected. After spraying through the AAO vibrating mesh, ginsenosides of the same component could be detected. Conclusion: A nutrient solution containing ginsenosides was successfully sprayed through the AAO vibrating mesh with 350 nm selective pores. In particular, during the atomizing experiment of ginsenoside drug solution having excellent efficacy in respiratory diseases, it was confirmed that atomizing through the AAO vibrating mesh while maintaining most of the active ingredients was carried out.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.392-399
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• 2012

This study was carried out to investigate the influence of molybden (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries. The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant. The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry. The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing. The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight. The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries. The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 $mg{\cdot}kg^{-1}$, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 $mg{\cdot}kg^{-1}$, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated. When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 $mg{\cdot}kg^{-1}$, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.147-151
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• 1986

A study was carried out to investigate yield, yield components, and change of chemical components in rice plants grown under different concentration of lead compound in nutrient solution of sandy culture. The results obtained are as follows. 1. Increasing lead concentration in culture solutions, pb content in the plant was increased and crop yields were decreased. 2. The critical pb concentration at which yield was declined, was 13.6 ppm. 3. As adding higher concentration of lead in nutrient solutions, concentration of lead in rice plant was significantly increased on leaf blade, and brown rice in pb. 4. Yield loss was closely related to pb content in leaf blade.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.95-102
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• 2013

There was a study for biological characteristics, except for physico-chemical and mineralogical properties, on the natural bentonite that is considered as a buffer material for the high-level radioactive waste disposal site. A bentonite slurry that was prepared from a local 'Gyeongju bentonite' in Korea was incubated in a serum bottle with nutrient media over 1 week and its stepwise change was observed with time. From the activated bentonite in the nutrient media, we can find a certain change of both solid and liquid phases. Some dark and fine sulfides began to be generated from dissolved sulfate solution, and 4 species of sulfate-reducing bacteria (SRB) were identified as living cells in samples that were periodically taken and incubated. These results show that sulfate-reducing (or metal-reducing) bacteria are adhering and existing in the powder of bentonite, suggesting that there may be a potential occurrence of longterm biogeochemical effects in and around the bentonite buffer in underground anoxic environmental conditions.