• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.25-31
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• 1986

This study was conducted to determine the effects of 5 years continuous application of compost and rice straw with the different rates of nitrogen fertilizer on physico-chemical properties of paddy soils and yield of rice. The results obtained were as follows; 1. The yield of rice was 7 and 4% higher at straw and compost treatment compared to the non-application of organic matter. The rate of yield response for nitrogen fertilizer was lowered as the amount of nitrogen application increased under the condition of organic matter application. 2. Dry mayer weight and total nitrogen content of rice plants were increased in the order of straw > compost > non-application of organic matter. Above two factors were positive correlations with yield but total nitrogen content was negative correlation with ripening rate. 3. $NH_4-N$ in the soil was higher at plot applicated with compost and straw than non-application. It was positive correlation ($r=0.62^*-0.79^{**}$) with total nitrogen content in rice plants from 15 days after transplanting to heading stage. 4. The physical properties of soil, hardness and infilteration rate, after 5 years experiment, were improved in the order of straw > compost > non-application of organic matter. Organic matter content in the soil was decreased 0.1% on the straw treatment after 4 years, 0.1% on the compost after 3 and 4 years, and 0.1% on the non-application every years.

• Tuberculosis and Respiratory Diseases
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• v.60 no.6
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• pp.663-672
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• 2006

Background: $PM_{10}$(Particulate matter with a diameter ($<10{\mu}m$), which is characterized by different environmental conditions, is a complex mixture of organic and inorganic compounds. The Asian dust event caused by meteorological phenomena can also produce unique particulate matter in affected areas. This study investigated the cytokine produced by A549 epithelial cells exposed to particles collected during both the Asian dust pfenomenon and ambient air particles in a non-dusty period. Method: Air samples were collected using a high volume air sampler(Sibata Model HV500F) with an air flow at $500{\ell}/min$ for at least 6 hours. The cytokine messenger RNA(mRNA) was measured using a reverse transcriptase polymerase chain reaction(RT-PCR). The A549 cells were exposed to 10 to $500{\mu}g/m{\ell}$ of a suspension containing $PM_{10}$ for 24 hours. Each was compared with those in the non-exposed control cells. Result: The mRNA levels of interleukin(IL)-$1{\alpha}$, $IL-I{\beta}$, IL-8, and the granulocyte macrophage colony stimulating factor(GM-CSF) increased after veing exposed to $PM_{10}$ in the ambient air particles, compared with those in the non-exposed control cells. The increase in $IL-1{\alpha}$ and IL-8 were dose dependent at a $PM_{10}$ concentration between $100{\mu}g/m{\ell}$ and $500{\mu}g/m{\ell}$. The mRNA level of IL-8 in the A549 epithelial cells was higher during the in the Asian dust period($500{\mu}g/m{\ell}$) than during the non dust period. Conclusion: A549 cells exposed to the $PM_{10}$ collected during the Asian dust period produce more proinflammatory cytokine than during non-dusty period. This cytokine enhances the local inflammatory response in the airways and can also contribute to the systemic component of this inflammatory process.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.125-130
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• 2004

This study has been assessed the influence of applying sewage sludge to soil amendments on the sorption properties, and leaching potential of three commonly used organophosphorus pesticides, Diazinon, Fenitrothion, and Chlorpyrifos. A sandy soil with a low content of organic carbon was treated with sewage sludge with a ratio sandy soil : sludge ratio of 30:1. The sorption was determined with the batch equilibrium technique. The sorption isotherms could be described by Freundlich equation. The Freundlich constant, K value which measures sorption capacity, were 3.97, 9.94, 22.48 for Diazinon, Fenitrothion, Chlorpyrifos in non-amended soil. But in amended soil, K value was 12.58, 28.47, and 61.21 for Diazinon, Fenitrothion, and Chlorpyrifos. The overall effect of sewage sludge addition to soil was to increase pesticides adsorption, due to the high sorption capacity of the organic matter. The effect of sludge on tile leaching of pesticides in the soil was studied using packed soil columns. Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 73～84%, was reduced with the passage of time. Diazinon moved more rapidly than Chlorpyrifos in the unamended soil due to greater sorption and lower water solubility of Chlorpyrifos. Total amounts of pesticides leached from the sewage sludge amended soils were significantly reduced when compared with unamended soils. This reduction may be mainly due to and increase in sorption in amended soils, as a consequence of the increase in the organic matter content.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.401-410
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• 2017

This study analyzed the changes in the concentrations of organic matters in constructed treatment wetlands, coming from discharge water from a sewage treatment plant and non-point pollutant sources during rainfall events. At the beginning of a rainfall event, a massive amount of particulate organic matter flowed in, and was removed from the sedimentation basin (S1, S2); dissolved organic matter was removed after passing through stepwise treatment processes in the wetland. During dry period in the wetland, the removal efficiency rate for COD and TOC was -21 and -7%, respectively; during the rainfall event, the removal efficiency rate for COD and TOC were 47 and 43%, respectively. The highly-concentrated organic matters that flowd in at the beginning of the rainfall event was stabilized by various structures in the wetland before water discharge. Cyanobacteria blooms annually at the confluence of the So-ok stream and Daecheong Lake. Therefore, it is expected that the wetland will contribute significantly to reducing cyanobacteria and improving water quality in the area.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.451-456
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• 2000

Fifty mid-lactation Holstein cows were used in a six-week feeding trial to study effects of high-forage, and high-fat diets on blood constituents, rumen fermentation and dry matter digestibility. Cows were divided into 10 replicates, each consisting of five cows. Each cow was assigned to a control (diet 1) or one of the four experimental diets (high-forage (75%), high-fat (7.5%) (diet 2); high-forage. medium-fat (5.0%) (diet 3); medium forage (65%), high-fat (diet 4); medium-forage, medium-fat (diet 5)), or a control diet containing about 50% forage and 2% fat. All diets were isonitrogenous (17.7% crude protein). The forage mixture consisted of 20% alfalfa hay, 40% alfalfa haylage, and 40% corn silage. Supplemental fat included 80% rumen-protected fat and 20% yellow grease. A non-significant difference was observed in concentrations of blood glucose for cows on different experimental and control diets. Plasma nonesterified fatty acids (NEFA) were higher in cows consuming experimental diets than those consuming the control diet. However, differences in NEFA concentrations in the plasma of cows consuming diets with different forage and fat levels were not significant. Rumen pH, concentration of volatile fatty acids (VFA) in rumen contents, and dry matter digestibility of control and experimental diets, and diets with different levels of forage and supplemental fat did not differ significantly.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1094-1101
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• 2000

Thirty-six crossbred (70% Holstein Friesian) cows in mid-lactation were assigned to one of four treatments. The dietary treatments were concentrate based, containing 13.5, 27.0, 40.5 and 54.0% of cassava in concentrate replacing ground maize (16.0% CP). There were curvilinear responses to intake of organic matter, non-structural carbohydrate and metabolisable energy. Cassava and corn fed in a ratio of 50:50 maximised organic matter, metabolisable energy intake; milk yield, milk protein and lactose yield. Milk fat yield was not affected by levels of inclusion. Dietary treatment did not influence ruminal pH, ammonia and volatile fatty acid concentrations or plasma glucose. The low market price for cassava resulted in a lower concentrate feed cost. The optimal level of cassava in a dairy cow diet is suggested as being between 20.0 and 30.0% of cassava in dry matter intake when fed with rice straw.

• Journal of Plant Biology
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• v.14 no.3
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• pp.21-28
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• 1971

Dry matter production, leaf area growth and total nitrogen changes were studied in Glycine max. soybean communities, which were grown in sandy loam soils controlled to provide various moisture levels, i.e., 5-7%(level 1), 8-10%(level 2), 11-13%(level 3), 14-15%(lev디 4), 17-20%(level 5) and 22-24%(level 6). A summary of the results is shown. The maximum dry matter production of leaves, stems and nodules and the maximum leaf area per unit area were at level 5, but the maximum of root dry matter production was at level 4. Total nitrogen content of the soybean plant decreased with growth, but each level of soil moisture content also showed a little difference. Water content of the plant decreased with plant age and soil water deficiency, especially in roots and nodules. Nodule formation increased in proportion to soil moisture content. total nitrogen content of the soil on which the soybeans grew, increased from 0.23% before sowing to 0.30% at 100 days after sowing. It seems that soil water content acts as a linear factor in the elongation or dry weight increase of shoots and roots until increasing to level 5. Considering the pattern of plant growth through analysis of the shoot and root dry weight ratio, or the photosynthetic organ and non-photosynthetic organ dry weight ratio, the asymptote of plant growth at a high soil water content exceeded that at a low soil water content.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.98-103
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• 2013

Conventional method to estimate mass of particulate matter accumulated in diesel particulate filter is to use pressure difference between upstream and downstream of the filter. Then measured pressure difference should be compared that of clean condition which is no particulate matter accumulated in DPF. During regeneration soot oxidation is also estimated by same method. This methodology, however, has demerit on accuracy because of pressure difference deviation of clean DPFs and pressure difference caused by non-carbon based PM which is different from that of caused by carbon based PM. This study suggests new methodology to estimate accumulated soot oxidation rate through exhaust gas characteristics during regeneration. Results, more high accuracy of soot oxidation was obtained by analysis of relationship between fuel mass and concentration of carbon dioxide and oxygen.

• Particle and aerosol research
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• v.19 no.4
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• pp.145-154
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• 2023

Granular bed filters are widely used to remove particulate matter in flue gas and are filled with various shapes of packing material. The packing material plays an important role in determining the overall collection performance, such as pressure drop and collection efficiency. The pressure drop of a granular bed filter has been calculated using the Ergun equation, while the collection efficiency has been predicted using the log-penetration equation based on the single sphere theory. However, a prediction equation of collection efficiency for a granular bed filter filled with non-spherical packing materials has not been suggested yet. Therefore, in this study, three different shapes of packing materials (sphere, cylinder, and irregular) were prepared to propose a prediction equation. The pressure drop and collection efficiency in a granular bed filter filled with each shape of packing material were measured experimentally and compared with theoretically predicted values. We found that experimentally measured pressure drops matched well with values theoretically predicted using the Ergun equation considering the shape factor. However, experimental collection efficiencies were higher than theoretical ones predicted by the log-penetration equation using the single sphere theory. We modified the log-penetration equation by employing a shape factor and found a good relationship between experimental and theoretical collection efficiencies.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.58-72
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• 2009

In this study, the organic matter and biomass was characterized by using respirometry based on ASM No.2d (Activated Sludge Model No.2d). The activated sludge models are based on the ASM No.2d model, published by the IAWQ(International Association on Water Quality) task group on mathematical modeling for design and operation of biological wastewater treatment processes. For this study, OUR(Oxygen Uptake Rate) measurements were made on filtered as well as non-filtered wastewater. Also, GC-FID and LC analysis were applied for the estimation of VFAs(Volatile Fatty Acids) COD(S_A) in slowly bio-degradable soluble substrates of the ASM No.2d. Therefore, this study was intended to clearly identify slowly bio-degradable dissolved materials(S_S) and particulate materials(X_I). In addition, a method capable of determining the accurate time to measure non-biodegradable COD(S_I), by the change of transition graphs in the process of measuring microbial OUR, was presented in this study. Influent fractionation is a critical step in the model calibrations. From the results of respirometry on filtered wastewater, the fraction of fermentable and readily biodegradable organic matter(S_F), fermentation products(S_A), inert soluble matter(S_I), slowly biodegradable matter(X_S) and inert particular matter(X_I) was 33.2%, 14.1%, 6.9%, 34.7%, 5.8%, respectively. The active heterotrophic biomass fraction(X_H) was about 5.3%.