• Journal of Energy Engineering
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• v.24 no.4
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• pp.24-32
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• 2015

National and international regulations on the exhaust gases of diesel engines are being strengthened, and a study of the combutsion engine and the post-porcessing system are in progress as a variety of ways. There are many techniques for the removal of nitrogen oxide like HC-SCR, LNT, Urea-SCR. And the technical development on the Urea-SCR owing to high conversion efficiency and fuel economy characteristics has being processed. This study investigated the physical/chemical properties of urea according to the change of the urea content, and were analysed the characteristic of exhaust gas. According to the increase of urea content, the contests of biuret aldehyde, phosphate content was increased and the changes of emission quantity of carbon monoxide, hydrocarbons and particulate matter in the exhaust gas was very slight. The emission quantity of NOx was decreased in accordance with increasing the urea content and it was shown to be more than 80 % in the urea solution having more than 30 wt%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.93-104
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• 2004

This pot experiment was conducted to investigate the effects of combined micronutrient application($T_1$; control, $T_2$; Fe, $T_3$; Fe+Mn, $T_4$; Fe+Mn+Cu, $T_5$ ; Fe+Mn+Cu+Zn, $T_6$ ; Fe+Mn+Cu+Zn+Mo, T$_{7}$; Fe+Mn+Cu+Zn + Mo + B) on forage performance of pure and mixed cultures of orchardgrass and white clover. The fifth part was concerned with the changes in the total and relative contents, uptake amounts, and mutual ratios. of micronutrients in forages. The results obtained are summarized as follows: 1. The relative contents(total contents of 6 micronutrients = 100%) of Fe and Mn were considerably influenced by the antagonism between Fe and Mn, and also were influenced by the differences in Mn-absorption between orchardgrass and white clover. Compared with pure culture, orchardgrass showed high relative contents of Mn, and low relative contents of Fe and B in mixed culture. White clover, however, tended to be exactly opposed to the above trends. In relative contents, the T$_6$ 6/ resulted generally in decrease of Fe. However the $T_7$ resulted in increase of Mn and B. In addition, the $T_7$ resulted in decrease of Cu and Zn in orchardgrass, and Mo in white clover. 2. In general, there were differences in the tendency between the yield changes and the uptake amounts of micronutrients. General differences have been showed in the uptake amounts and mutual ratios of micronutrients based on the forage species, pure/mixed culture, additional fertilization, and antagonism. The uptake amounts of total micronutrients were generally increased by the treatments with increased combination. In uptake amounts, the $T_7$ resulted in the increase of Mn and B, and decrease of Mo. 3. The mutual ratios of Fe/Mn, Fe/Cu, and Mn/Cu were considerably influenced by the antagonism between Fe and Mn. At the $T_7$ , very low ratio of Fe/Mo affected by the T6 tended to be somewhat improved because of the decrease of Mo content． The poor growth of forages at the $T_6$ was improved by the $T_7$ . This fact was likely to be caused by the adequate B/Mo ratio.

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.86-88
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• 1993

The effect of short term duration(1, 2 and 3 days) after urea foliar spray on leaf quality was investigated by chemical analysis of leaves and silkworm rearing with leaves treated with urea in autumn. Foliar spray increased water content by 0.4~0.7% and total nitrogen by 0.19~0.51% in leaves compared to the conventional treatment. Foliar spray increased NO3-N concentration in leaf 503~1107 ppm more than the conventional treatment. NO3-N concentration in leaf decreased with days after foliar spray. Whole cocoon weight and cocoon shell weight increased by 0.02~0.14g and 0.5~3.1 cg, respectively in foliar spray than in the conventional treatment. Though foliar spray raised NO3-N concentration in leaf, leaves harvested one day after foliar spray were no harmful to silkworm.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1307-1319
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• 2018

As interests in the air pollution increases, many kinds of researches are underway on the reduction of air pollutants. The removal of nitrogen oxides from the emission gas of diesel vehicles using urea solution has shown a great effect. The quality of urea solution is strictly defined by domestic law, but the increase of impurities in urea solution reduces the effect of reducing nitrogen oxides. Therefore, in this study, the change of physical properties of urea solution was analyzed after heating the urea solution for a certain temperature and time. Also, the changes of physical properties of urea solution were analyzed according to kinds of storage container and temperature for storing the urea solution. After heating the urea solution for a certain period of time, the biuret content in urea solution increased and the content of urea decreased. As the urea content decreased, both density and refractive index decreased. In the storage stability test carried out at a constant temperature with iron and PET containers, no change in physical properties was observed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.200-206
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• 1985

This field experiment was undertaken to assess the effects of three levels of inclination ($10^{\circ},\;20^{\circ},\;and\;30^{\circ}$) and four rates of $N-P_2O_5-K_2O$ (0-0-0-, 14-10-10, 28-25-25, and 42-40-40kg/10a) on establishment, yield and quality, and botanical compositions of mixed grass-clover sward. This second part is concerned with the soil chemical properties, concentrations and uptake of mineral nutrients, and percent recovery and efficiency of NPK. The results obtained after a two-year experiment are summarized as follows: 1. The pH, exchangeable Mg and Na, and base saturation in the surface soils were decreased by increasing the grade of inclination, whereas organic matter and available $P_2O_5$ tended to be increased. However, the changes in the Ca content and equivalent ratio of $K\sqrt{Ca+Mg}$ were not significant. The pH, exchangeable Ca and Mg, and base saturation were reduced by increasing the NPK rate, whereas available $P_2O_5$, exchangeable K, and equivalent ratio of $K\sqrt{Ca+Mg}$ tended to be increased. 2. The concentrations of mineral nutrients in grasses and weeds were not significantly affected by increasing the grade of slope in hilly pasture, whereas the concentrations of N, K, and Mg in legume were the lowest with the steep slope, which seemed to be related to the low legume yield. The Mg concentrations of all forage species were below the critical level for good forage growth and likelihood of grass tetany. 3. The increase of NPK rate resulted in the increment of N, K and Na concentrations, and the decrease of Mg and Ca in grasses. The P concentration was increased with P application, but there were no differences in that among the P rates applied. It resulted also in a slight increase of K, and a decrease of Mg in legume, but the contents of N, Ca, and Na were not affected by that. On the other hand, it has not affected the mineral contents in weeds except a somewhat increase of N. The mixed forages showed a increase of N and K contents, a decrease of Ca and Mg, and a slight change in P and Na. 4. The percent recovery of N, P and K by mixed forages were greatly decreased by increasing the grade of inclination and NPK rate. They were high in the order; K>N>P. The efficiency of mixed NPK applications was decreased by that. The efficiency of mixed NPK fertilizers absorbed was slightly decreased by the increased rate of NPK, but it was not affected by the grade of inclination.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.11-20
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• 2004

This pot experiment was conducted to investigate the effects of combined micronutrient application($T_1$;control, $T_2$; Fe, $T_3$; Fe＋Mn, $T_4$: Fe＋Mn＋Cu, $T_5$ ; Fe＋Mn＋Cu＋Zn, $T_6$ ; Fe＋Mn＋Cu＋Zn＋Mo, $T_7$ ;Fe＋Mn＋Cu＋Zn＋Mo＋B) on forage performance of pure and mixed cultures of orchardgrass and white clover. This 4th part was related to the changes in the contents of micronutrients(Fe, Mn, Cu, Zn, Mo, and B) in forages. The results obtained are summarized as follows: 1. General differences have been showed in the contents of micronutrients based on the treatments, forage species, pure/mixed culture, cutting order, and additional fertilization, especially N. Compared to pure culture, orchardgrass showed relatively high contents of Mn and Zn, and low contents of B and Fe in mixed culture. White clover, however, tended to be exactly opposed to the above trends. The contents of Cu and Mo did not show any differences between pure and mixed cultures. 2. In relative comparison, the $T_7$ influenced negatively on the contents of Cu, Zn, and Mo in orchardgrass. The $T_7$ also influenced negatively on the contents of Mo in white clover. However, the $T_7$ influenced positively on the contents of Mn in orchardgrass, and also influenced positively on the contents of Fe, Mn, and Cu in white clover. Because of the antagonism between Fe and Mn, the Fe contents in both forages were significantly decreased by the $T_3$. Under the various conditions, the differences among Fe contents tended to be more significant in white clover than in orchardgrass. 3. At the $T_6$ and $T_7$, the Mo contents in both forages tended to be relatively high. The Mo contents, however, were somewhat decreased by the $T_7$ 7/. The Mo-toxicity, which was caused by the high Mo-contents, tended to be diminished, and was likely to be prevented by the optimum B/Mo ratio and B application($T_7$ ).

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.114-120
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• 2000

The aim of this study was to investigate the effects of slow-released nitrogen fertilizer(SRNF) on the growth and yield of rice. SRNF produced from wasted paper was applied to a clay loam paddy field comparing to urea fertilized field and only P-and K-fertilized field. Some agronomic components like as growth development and yield component were observed and physico-chemical properties of the soils were analyzed. Plant height and tiller numbers per hill showed higher in rice plant treated with SRNF than in one treated with urea at the early grow stage whereas they appeared to be all much the same at the end of growth stage. While the chlorophyll content in SRNF-treated rice shoot was higher than in urea-treated one, the photosynthetic activity in urea-treated rice shoot was slightly higher than in SRNF-treated rice. In harvested grain, the nitrogen content was higher than in SRNF treated rice than in urea treated rice, but in straws the content was less. At the harvesting stage, nitrogen uptake in grains was about 4% higher in SRNF-treated rice than in urea treated rice whereas in straws rather 20% lower. The N efficiency in SRNF treated rice was lower than in urea treated rice. In the soils treated with SRNF, pH, organic matter and phosphorus were higher than in the soils treated with urea. Total N content in SRNF treated soil was lower after experiment than in urea treated soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.278-285
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• 1993

This experiment was conducted to investigate the productivity in permanent orchardgrass grassland according to the urea fertilization levels of 0, 100, 200 kg N/ha and the animal excreta fertilization levels of 0. 40, 80, 160 kg N/ha on the basis of N contents respectively and NO$_3$-N content of the soil. The results were obtained as follows; 1. The productivity of grassland was significantly increased by the increase of the excreta fertilization levels until the urea-N level fertilization of 100 kg/ha but repressed and reduced by the increase to 160 kg/ha level of the animal excreta fertilization at urea-N fertilization level of 200 kg/ha. 2. Averaged seasonal productivity of the animal excreta N was decreased in first and third cutting time and was increased in second cutting time according to the increase of urea-N fertilization. 3. The increase of urea-N and animal excreta N increased the content of crude protein but the fertilization effect of urea-N was higher than that of animal excreta N. 4. The total yield of N was continuously increased at both of the urea-N and animal excreta N but the pure yield of N was decreased according to the increase of N fertilization and showed -63.1 kg/ha at the fertilization of the urea-N of 200 kg N/ha and animal excreta N of 160 kg/ha. 5. NO$_3$-N content of the soil of orchardgrass glassland established one year previously was no difference among the N variety and fertilization levels but was increased to the order of summer, autumn and winter. The highest content of NO$_3$-N was measured in winter with the value of 34.9 ppm.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.122-128
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• 1997

A pot experiment was carried out using Seomjin-byeo and Samgang-byeo to investigate the effects of nitrogen and sulfur on the growth, yields, and sulfur containing amino acid content of rice. The yields and number of tillers at 50 days after transplanting were increased with the increase of the amounts of nitrogen and sulfur, but N/S ratio was decreased in both varieties. There were a positive correlations between yield and contents of nitrogen and sulfur in straw and brown rice, but a negative correlation between N/S ratio and yields at harvesting stage. Crude protein contents increased with the increase of amounts of nitrogen and sulfur. contents of amino acid containing sulfur in brown rice were positively correlated with the sulfur and nitrogen contents in rice straw.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.29-36
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• 1992

The experiment was conducted to evaluate the effects of organic fertilizer. Sarang of fermented poultry manure. Miwon glutamic acid fertilizer and poultry manure, on the growth and yield of radish cultivated in spring and autumn. 1) The growth of leaf length, leaf weight, root length, root diameter and root weight of radish in two culture types was stimulated in order of NPK, fermented poultry manure + 1/5NK, fermented poultry manure, poultry manure and control treatment, and chlorophyll and nitrogen content of leaf were increased in order of the above mentioned fertilizers.2) Yield decreased in fermented poultry manure plot of 450kg application comparison with NPK plot but the one of 1800kg fermented poultry manure was increased. The yield of 450kg Sarang plot was sufficient as compared with Korean average yield of spring and autumn culture.3) The difference of growth of radish between treatments of fermented poultry manure and NPK was lowered by continuous application of Sarang organic fertilizer.4) Soil nitrogen content and exchangeable Mg were similar in all treatments but soil pH, the contents of organic matter, $P_2 O_5$ and Ca were high in the fermented poultry manure treatment.