• Journal of Korean Society on Water Environment
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• 제32권3호
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• pp.291-296
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• 2016

This study investigated the potential use of soybean stover (SS) (0.1-0.5 g/100 mL)and rice hull (RH) (1.5-3.5 g/100 mL) derived biochars for removing methylene blue (100 mg/L) from wastewater compared to activated carbon (AC) (0.1-0.5 g/100 mL). The adsorption equilibrium data were best represented by Langmuir adsorption isotherm. The calculated maximum adsorption capacity was 71.42 mg/g for AC, 30.30 mg/g for SS, and 4.76 mg/g for RH. The adsorption kinetics was found to follow the pseudo-second order kinetics model. The rate constant was 0.0020-0.0065 g/mg.min for AC, 0.0069-0.5787 g/mg.min for SS, and 0.1370-0.3060 for RH. AC and SS biochars showed considerable potential for adsorption.

• Korean Chemical Engineering Research
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• 제59권1호
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• pp.54-59
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• 2021

The pretreatment of cellulosic biomass is essentially needed because it has more lignin compared with a starch biomass. Ethanol as an organosolv for pretreatment can easily separate some components which can inhibit enzymatic hydrolysis and be re-usuable by distillation. The flow-through process have some strength, separating components continuously, development for scale up. In this research, two-kinds (wheat straw, miscanthus) of biomass was pretreated for development of enzymatic hydrolysis by adoption of pretreatment process of corn stover.

• Korean Journal of Medicinal Crop Science
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• 제11권2호
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• pp.109-114
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• 2003

To determine the optimum N rate m Jeju island for utricle and root production of Achyranthes japonica Nakai, a medicinal plant, the plants were grown at two plant densities $(50\;and\;100\;hills/m^2$, two plants per hill; mall plots) at six N application rates (0, 6, 12, 18, 24, and 30 kg/10a; split plots) in 2001. There was no significant interaction between plant density and N application rate for all measured agronomic characters. Main root length and roots per hill were 5 and 52% greater, respectively, but N content of stover was lower under lower plant density compared to higher plant density. The other characters were not affected by plant density. N application rate did not significantly affect mall stem diameter, spikes per hill, spike length, utricles per spike, mall root length and diameter, and utricle N content. As N rate increased from 0 to 30 kg/10a, SPAD values and stover N content increased linearly from 35.0 to 40.5 and 1.09 to 1.38%, respectively, and plant height, branches per hill, stover, utricle and root dry matter yields, roots per hill, and top N yield increased quadratically. Spikes per hill were increased in a cubic manner with increased N application rates. N application rate for the maximum dry matter yield of utricle and root in A. japonica was estimated to be 21 kg N/10a.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제46권4호
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• pp.266-271
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• 2001

Soybean can produce high-N residue due to N-fixation, so soybean rotation may increase yield of subsequent corn and reduce N fertilizer on the corn fairly. To find out the contribution of nitrogen to subsequent corn following soybean cultivation, soil nitrate, corn yield, and nitrogen uptake were measured for three continuous corn cropping years after soybean rotation. Three N rates of 0, 80, and 160 kg/ha were applied to three continuous corn following soybean cropping. At 6-leaf stage, soil nitrate amount at the soil depth of 0-30cm ranged from 60 to 80 kgN/ha higher in the first corn cropping year than that in the second and third corn cropping years. Judging from corn N status such as SPAD value, N concentration of ear-leaf and stover at silking stage, N contribution of previous soybean to corn in the first corn year was N fertilizer of approximately 80 kg N/ha. Stover N uptake at silking stage increased from 47 to 52 kg N/ha at the 0, and 80 kg N/ha of N rates in the first corn cropping year compared with those in the second and third corn cropping years. Corn grain yield at the 0 kg N/ha of N rate was 6-7 ton/ha higher in the first corn cropping year than that in the second and third corn cropping years, respectively. When compared the first corn year following soybean cropping with the second and third corn cropping years, N uptake of grain and stover at harvest with low N rates such as 0 and 80 kg N/ha increased from 45 to 67kg N/ha, from 35 to 60 kg N/ha, respectively. N uptake of whole plant by soybean rotation increased from 93 to 118 kg N/ha in the first year compared with that in the second and third corn cropping years. However, the N contribution by soybean cropping was small in the second and third continuous corn cropping years. Therefore, it was concluded that the nitrogen fertilizer of 80-100 kg N/ha in the first corn cropping year could be saved by soybean rotation and annual alternative corn-soybean rotation could be the best rotation system.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1996년도 춘계 학술대회논문집
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• pp.33-39
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• 1996

An incompressible flow stover based on the unstructured finite volume method has been developed. The flow domain is discretized by triangles in 2D or tetrahedra in 3D. The convective and viscous fluxes are obtained using edge connectivities of the unstructured meshes. The pressure-velocity coupling is handled by the artificial compressibility algorithm due to its computational efficiency associated with the hyperbolic nature of the resulting equations. Laminar test flow problems are computed and presented with a comparison against other numerical solutions or experimental results.

• Journal of Korean Society for Atmospheric Environment
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• 제30권1호
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• pp.48-58
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• 2014

It is very important to investigate air pollutants emissions emitted from open burning in order to control nonpoint sources effectively. In this study, we utilized incineration simulator proposed by U.S EPA and investigated emissions of CO, OC/EC, from household waste and biomass burning to estimate pollutant emissions by illegal incineration of biomass wastes. Emission factor of OC was estimated as 17.1 g/kg for rice strew, 23.5 g/kg for barley, 10.3 g/kg for corn stover, 4.3 g/kg for unseasoned wood, respectively. In case of EC, it was calculated as 1.6 g/kg for rice strew, 4.3 g/kg for barley, 1.4 g/kg for corn stover, 0.6 g/kg for unseasoned wood, respectively. Most of the pollutants emissions were emitted at the stage 1 and 2. In the stage 3, the pollutants concentration decreased gradually. To estimate emissions and build inventory for biomass burning, we need to know accurate activity data. We, therefore, used activity data of both survey results of previous study and statistical data of National Statistical Office. However, we need to perform additional experiments in the future to obtain more accurate activity data for various cases.

• Asian-Australasian Journal of Animal Sciences
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• 제33권11호
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• pp.1770-1778
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• 2020

Objective: This study was conducted to reveal potential metabolic differences of dairy cows fed corn stover (CS) and rice straw (RS) instead of alfalfa hay (AH) as main forage source. Methods: Thirty multiparous mid-late lactation Holstein dairy cows were selected and randomly assigned to three diets, AH, CS, or RS (n = 10). After 13 weeks of the feeding trial, coccygeal arterial and superficial epigastric venous plasma samples were collected before morning feeding for gas chromatography time-of-flight/mass spectrometry analyses. Results: In the artery, 8 and 13 metabolites were detected as differential metabolites between AH and CS, and between AH and RS, respectively. The relative abundance of phenylpropanoate (log₂fold change [FC]) = 1.30, 1.09), panthenol (log₂FC = 2.36, 2.20), threitol (log₂FC = 1.00, 1.07), and 3,7,12-trihydroxycoprostane (log₂FC = 0.79, 0.78) were greater in both CS and RS than in AH, and tyrosine (log₂FC = -0.32), phenylalanine (log₂FC = -0.30), and pyruvic acid (log₂FC = -0.30) were lower in RS than in AH. In the vein, 1 and 7 metabolites were detected as differential metabolites between AH and CS, and between AH and RS, respectively. By comparing AH and RS, we found that metabolic pathways of phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism were enriched by integrative artery and vein analysis. Furthermore, AH and RS, arterial phenylpropanoate and 4-hydroxyproline were positively, and phenylalanine was negatively correlated with milk urea nitrogen. Finally, in AH and CS, arterial panthenol was negatively correlated with feed efficiency. Conclusion: Arterial metabolic profiles changed more than those in the veins from animals on three forage diets, differing in amino acids. We found that phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism were restricted when cows were fed low-quality cereal straw diets.

• Korean Journal of Organic Agriculture
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• 제23권3호
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• pp.497-507
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• 2015

It is necessary to evaluate the resistance to disease among genetic resources for development of disease resistant grapes. This study was conducted to screen the resistance to crown gall in muscadine and Florida hybrid bunch grapes by pathogen inoculation. In order to compare the responses to infection with different pathogen strains, muscadine and Florida hybrid grapes were inoculated with 3 strains of Agrobacterium vitis. Although there were different levels crown gall formation among grape cultivars, there little variation in response to inoculated strains. Among 29 muscadine cultivars tested by inoculation of A. vitis 'C4612', most of them were shown to be susceptible, and 'Gold Isle' and 'Africa Queen' were highly susceptible, and two cultivars, 'Welder' and 'Jumbo' were found to be resistant to crown gall disease. Among Florida hybrid grapes, 'Daytona', 'Stover', and 'Swanee' were susceptible and 'Blanc du Bois' was moderately susceptible to crown gall. Because muscadine grapes have been actively utilized as useful genetic resources for development of new grape varieties by intersub-genus cross, this result from the screening of resistance among muscadine grapes can provide valuable information in breeding programs of grape resistant to crown gall.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.191-196
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• 2002

In this paper we introduce novel electrode structure for high efficiency discharge. We operate discharge tube under the 0.16 torr pure Xe and apply the sinusoidal wave power to the lamp with 60kHz. We measure the electric power dissipation, plasma parameters, and 828 nm IR intensity. From these data we determine the discharge efficiency, IR intensity/watt, EEDF(Electron energy distribution function). As a result we obtain that the novel electrode structure has better performance in efficiency than that of conventional external electrode system. Also we determine the EEDF for each type of electrode structure by Boltzmann stover, EELNDIF code. The result of Boltzmann equation solving show that the noble electrode system has many high energy electrons compared with the conventional system.

• Asian Journal of Turfgrass Science
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• 제12권4호
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• pp.203-210
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• 1998

Environmental concerns arising from synthetic herbicides in plant management systems have led to an interest in plant-derived compounds as natural herbicides. Inhibitory effects of compounds extracted with 50% methanol from corn (Zea mays L.) and pine (Pinus densiflora L.) were evaluated on large crabgrass (Digitaria sanguinalis (L.) Scop.), annual bluegrass Poa annua L.), radish (Raphanus sativus L.), and perennial ryegrass (Lolium perenne L.) The aqueous extracts inhibited seed germination and had postemergence activity on the four species. The stability of biological activity of corn grain, stover, and root extracts was not affected by heating to $135^{\circ}C$ or freezing/thawing treatments when applied at levels above 0.25kg m(sup)-2 based on dry weights of powders before extraction. Heating reduced the activity of pine litter and bark extracts at all levels except the highest application level but had little effect on pine needle extracts.