• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.47-53
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• 1991

A laboratory experiment was conducted in order to learn the effect of a number of organic matters on the ammonification and nitrification of urea, and the reaction of soil, applied to a loamy upland soil poor in orgnic matter(<1.5%, without plants 1.The ammonification of urea was most pronounced in one week period immediatly after fertilizer and water treated, after which a rapid decrease of it was followed showing no accumulation at the end of 3rd week. Owing to the accumlation of ammonium, pHs of treated soils were read 7.0 to 7.3 from 6.8~6.9. 2.Nitrification was also progressed rapidly in the first one week period so that the accumulation of NO$_3$-N surpassed that of ammonia during this period. After the 1st week the accumulation of N0$_3$-N was continuously increased showing the maximum at the end of 4 weeks following a sharp decrease at the end of 5th weeks. The accumulation of NO$_3$-N dropped soil pH from 6.8-7.0 to 6. 0-6.2,but the decrease of NO-N at the end of 5th weeks brought up soil pH to 6.4-6.6. again. 3.Amino acid fermentation byproduct rich in salt, paticularly chloride, slowed down the ammonification and nitrification of urea. 4.The application of organic matter diminished the acidifying effect of chemical fertilizers. The diminishing effect of soluble humic acid and amion acid fermentation byproduct showed greater than that of solid organic matter in this experiment, which might be own to the application of a rather small amount of water soluble organic matters. Rice straw powder among solid organic matters appeared to be the least in the diminishing effect above. It may be reasoned that these soluble organic matters decomposes rapidly so as to affect Soil pH, but solid organic matters, particularly the rice straw powder, form acidic humus.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.829-846
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• 2015

This study was conducted to determine the effects of organic fertilization rates on the nutrient accumulation and recovery in radish (Raphanus sativus L.) as well as growth and yield of radish in Jeju island. An understanding the relationships between organic fertilization rate, crop nutrient recovery and crop yield can assist in making organic fertilizer recommendation which balances crop value and environmental risk in organic cultivation. Nitrogen (T-N), phosphate ($P_2O_5$) and potassium ($K_2O$) were applied at 0, 115-35-40, 230-70-80 (standard application rate), 460-140-160, 230-200-100 (recommended application rate) and 158-53-35 kg/ha (customary application rate), respectively as the broadcast application of mixed organic fertilizer (N 4.5% - $P_2O_5$ 1.5% - $K_2O$ 1%) in combination with langbeinite ($K_2O$ 22%), 100% at sowing period. The organic fertilizer was made of organic materials like oil cakes. Total yield of radish, as fresh weight of roots, increased with increasing organic fertilizer doses to a maximum at rate of standard or soil-testing application. Nitrogen, phosphate and potassium accumulations of radish increased curvilinearly with increasing organic fertilization rate to a maximum at rate of N 460 - $P_2O_5$ 140 - $K_2O$ 160 kg/ha. However, nitrogen, phosphate and potassium use efficiency of applied organic fertilizer decreased curvilinearly or linearly with increasing organic fertilization rate. Application of organic fertilizer in combination with langbeinite (as a potassium source) had significant effect on the yield of radish. Organic fertilization on a basis of standard or soil-testing application rate is recommended for maximun radish yield in organic cultivation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.88-94
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• 1998

Korea has been rapidly industrialized during the past 35 years. During this period, Korea has emphasized only production and workers health has been ignored. Workers are most frequently exposed to organic vapors, such as thinners. This study was performed to evaluate worker exposures to organic solvents by size and type of industry. Results are summarized below. Workers were exposed to mixtures of toluene, xylenes, trichloroethylene, n-hexane, acetone, methanol, n-butanol, n-butyl acetate, and MIBK. Considering additive effects of the compounds, exposure indices (EIs) were calculated. It was found that worker exposures to organic solvents were highest in small industries and lowest in large industries. During a day shift, the highest exposure was indicated 3 - 5 p.m. in the afternoon. Workers in small industries had potential exposures exceeding permissible exposure limits for organic solvents. Local exhuast systems were inappropriate and respiratory protective devices were not supplied to the workers in small industries. Neither program for safe use and storage of toxic materials nor program for respirators was found in any of the plants investigated. Based on the results of the study, workers of small scale industries should be considered first in industrial health.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.274-288
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• 2018

Quantitative data of 50 non-polar organic compounds constituting $PM_{2.5}$ were continuously collected and analyzed from June 2016 to October 2017 (approximately 17 months) at Ichihara, one of the largest industrial areas in Japan. Target non-polar organic compounds including 21 species of polycyclic aromatic hydrocarbons (PAHs), 24 species of n-alkanes and 5 species of phthalate esters(PAEs) were simultaneously measured by gas chromatography/mass spectrometry. Basically, the average concentrations of the total PAHs, n-alkanes and PAEs in each season remained nearly level, and seasonal variations were little throughout the study period. These results suggest that the emission sources, which are not influenced by the seasons, are the dominant inputs for the target organic compounds. Diagnostic ratios of PAHs, assessment of n-alkane homologue distributions, carbon preference index, and the contribution of wax n-alkanes from plants were used to estimate source apportionments. These results indicate that anthropogenic sources were the main contributor for most PAHs and n-alkanes throughout the study period. The concentrations of PAEs selected in this study were low because emission amounts of these chemicals were little within the source areas of the sampling site. To our knowledge, this study is the first attempt to simultaneously measure a high number of non-polar organic compounds in $PM_{2.5}$ collected from the ambient air of Japan, and the resultant data will provide valuable data and information for environmental researchers.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.615-626
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• 2020

The objective of present experiment was to examine the impact of different organic nitrogen (N) fertilizer application rates and different harvesting periods on the forage yield and feed value of kenaf (Hibiscus cannabinus L.). This study was carried out from May to September 2019, the amount of 80 kg of kenaf seed/ha were applied with different rates of nitrogen fertilizer. The plants were sampled at 10 days intervals (100, 110, 120, and 130 days after seeding) from different harvesting dates. In the organic fertilizer treatments, the highest dry matter (DM) yield was observed in the application rate at 250 kg of N/ha. Crude protein (CP) content in leaves was similar between the organic fertilizer rates at 200 and 250 kg of N/ha and were higher compared with other fertilizer treatments. The highest CP content in the stem was 4.3% in the organic fertilizer application rates st 250 kg of N/ha. Neutral detergent fiber (NDF) in leaves showed no significant difference between the chemical fertilizer rates at 200 and 250 kg of N/ha, and the organic fertilizer rates at 150 and 250 kg of N/ha. In addition, DM yield of kenaf was highest in the harvest of 100 days after seeding, and tended to decreased significantly with increase of harvesting periods (p<0.05). As the growth progressed, the plant height and stem ratio increased but the leaves ratio decreased significantly (p<0.05) and the highest was found at 110 days after seeding. The highest CP, Acid detergent fiber (ADF), NDF and total digestible nutrient (TDN) contents in leaves were 13.9, 25.4, 40.5 and 71.1%, respectively that were affected by different harvesting periods. Also, the ADF and NDF in stem increased significantly with increase of kenaf maturity (p<0.05). In conclusion, the optimal organic fertilizer application rates and the proper harvesting periods for the forage yield and quality of kenaf were at 200 to 250 kg of N/ha, and 100 to 110 days after seeding, respectively.

• KSBB Journal
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• v.29 no.2
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• pp.118-123
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• 2014

It was confirmed that malodor connected with an air-conditioner in an automobile is caused by microbial volatile organic compounds (MVOCs) produced by microorganisms getting into an air-conditioner when it is operating. Chemicals such as hydrogen sulfide, dimethyl sulfide, nbutyric acid, n-valeric acid, iso-valeric acid, n-octanol and toluene were detected above the odor threshold inside the automobile. The characteristics of a funky odor in the air blown into the automobile were due to detected sulfur compounds (hydrogen sulfide and dimethyl sulfide). Dimethyl sulfide was produced by microorganisms such as Aspergillus versicolor, Methylobacterium aquaticum, Herbaspirillum sp. and Acidovorax sp. In addition, the characteristics of a sour odor in the air blown into the automobile were due to detected organic acids (n-butyric acid, n-valeric acid and iso-valeric acid). N-valeric acid and iso-valeric acid were generated from Aspergillus versicolor, while iso-valeric acid was produced by Methylobacterium aquaticum. In addition, the odor intensity of the air blown into the automobile was affected by the concentration of detected sulfur compounds and organic acids. On the other hand, it is estimated that chemicals such as hydrogen sulfide, n-octanol and n-butyric acid detected in the air blown into the automobile were produced by non-identified species of microorganisms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.177-180
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• 2002

The purpose of this thesis is to develope buffer materials by the plasma polymerization method. In this article the buffer materials, plasma poly thiophene(PPTh) is used to study the interface of eter/organic in organic light emitting diodes(OLED). The interface of meter/organic materials is the important and critical objectives in development of OLED. The hole transport layer was N,N'-dipheneyl-N, N'bis-(3-methypheneyl)-1,1'dipheneyl-4,4'-diamine (TPD); the host material of mission layer was 8-tris-hydroxyquinoline aluminium (Alq3). When PPTh was inserted between ITO and TPD, emission efficiency increased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.897-902
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• 1998

We prepared Organic LED with a two layer structure by vacuum evaporation. The diode consisted of hole transfer layer (thickness of 30, 50, 70 nm) and electron transfer layer (thickness of 70, 50, 30 nm) material, which was N, N'-diphenyl- N, N'-bis-(3-methyl phenyl)-1,1'-diphenyl-4,4'-diamine)(TPD) and tris(8-hydroxy quinoline) aluminum(Alq3), respectively. We investigated EL properties of the LED with various thickness and cathode electrode. The best results were obtained when thickness of the electron layer is equal to that of emission layer and when AlLi alloy was used as a cathode. The EL intensity, luminance and efficiency of organic LED with equal of layer thick were improved seven, three and two times, respectively. Alq3 was ionized by carrier injection from cathode and could produce exitons. After electron-hole pairs were formed by combination of the electrons and holes at the emission layer, Alq3 layer emitted light.

• Ocean and Polar Research
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• v.33 no.1
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• pp.55-68
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• 2011

The distribution and inter-annual variation of nutrients (N, P, Si) and dissolved/particulate organic carbon were investigated in the equatorial thermocline ridge ($7^{\circ}{\sim}11.5^{\circ}N$, $131.5^{\circ}W$) of the northeast Pacific. From the Oceanic Nino Index and Multivariate ENSO Index provided by NOAA, normal condition was observed in July 2003 and August 2005 on the aspect of global climate/ocean change. However, La Ni$\~{n}$a and El Ni$\~{n}$o episodes occurred in July 2007 and August 2009, respectively. Thermocline ridge in the study area was located at $9^{\circ}N$ in July 2003, $8^{\circ}N$ in August 2005, $10^{\circ}N$ in July 2007, and $10.5^{\circ}N$ in August 2009 under the influence of global climate/ocean change and surface current system (North Equatorial Counter Current and North Equatorial Current) of the northeast Pacific. Maximum depth integrated values (DIV) of nutrients in the upper layer (0~100 m depth range) were shown in July 2007 (mean 21.12 gN/$m^2$, 4.27 gP/$m^2$, 33.72 gSi/$m^2$) and higher variability of DIV in the equatorial thermocline ridge was observed at $10^{\circ}N$ during the study periods. Also, maximum concentration of dissolved organic carbon (DOC) in the upper 50 m depth layer was observed in July 2007 (mean $107.48{\pm}14.58\;{\mu}M$), and particulate organic carbon (POC, mean $9.42{\pm}3.02\;{\mu}M$) was similar to that of DOC. Nutrient concentration in the surface layer increased with effect of upwelling phenomenon in the equatorial thermocline ridge and La Ni$\~{n}$a episode, which had formed in the central Pacific. This process also resulted in the increasing of organic carbon concentration (DOC and POC) in the surface layer. From these results, it is suggested that spatial and temporal variation of chemical and biological factors were generated by physical processes in the equatorial thermocline ridge.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.138-143
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• 2011

BACKGROUND: This study was conducted to investigate growth and yield of organically grown rice under a typhoon during a fall. The treatments included NPK chemical fertilizer, compost, oilcake, oilcake 2X, hairyvetch, and vetch+rye. METHODS AND RESULTS: Nutrient applications were made at rates equivalent to approximately 0.9 kg of actual N per acre. Oilcake and hairyvetch treatments had the lowest C:N ratio, but compost had the highest C:N ratio of 34:1. Rice treated by organic nutrient sources had great growth and development at the beginning of the growing season but had depressed growth and yield at the harvest. Oilcake 2X-treated rice in early growing season, especially, showed better growth and development than rice treated by other nutrient sources but was severely lodged at the harvest season due to the typhoon. Compost treatment with high C:N ratio slowly released inorganic N and produced poor rice growth and yield; however, it recued rice lodging. N uptake was the greatest for the oilcake 2X and vetch+rye treatments but the lowest for the compost, which was the similar pattern to the N use efficiency; the greatest and lowest N use efficiency was observed for the oilcake 2X (55%) and compost (5%), respectively. CONCLUSION(s): Rice lodging should be prevented by reducing the excessive nitrogen supplement, resulting from the lower C:N ratio of the organic materials as well as prevented by the radical midsummer drainage. Vetch+rye treatment with 25:1 of C:N had optimum vegetative growth and reduced rice lodging, which increased N use efficiency and yield.