• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.1
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• pp.15-24
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• 2010

This study was conducted to investigate the effects of swine manure (SM) application with additional nitrogen (N) fertilizer on productivity of corn and environmental pollution in com cultivation soil. The experiment was conformed in lysimeter which was constructed with 30 cm diameter, and 100 cm height. Swine manures used in this study were the compost of swine manure fermented with sawdust (SMFWS) and soft rice hulls treated with high temperature and high pressure (SRH), and swine slurry (SS). The application rates of the additional N, as urea, with swine manure were 50 and 100 kgN/ha on each plot. This study was arranged in completely randomized design with three replication. DM yields in SM treatments with mineral N were increased significantly compared to those in SM treatment without mineral N (zero-mineral N) (P<0.05) and increased as the rate of mineral N application increased (P<0.05). DM yields in SMFWS and SS treatments with mineral 100 kgN/ha showed trends similar to those of chemical fertilizer (control) but higher than those of 50 kg N/ha. DM yields tended to be higher in SMFWS and SS treatments than in SRH treatment. Total N contents in SMFWS, SRH and SS treatments with mineral N were increased, compared with SM treatment without mineral N. N contents in SM treatments with mineral N were lower than those of chemical fertilizer treatment, but N content of chemical fertilizer treatment showed trends similar to that of SS treatments with mineral 100 kgN/ha. $NO_3$-N concentration in SM treatments with mineral N were increased significantly, compared to those in SM treatment without mineral N and in chemical fertilizer (P<0.05). $NH_4$-N concentrations in SMFWS and SS treatments with mineral 100 kgN/ha showed trends similar to those of chemical fertilizer, but higher than those of 50 kg N/ha. $PO_4$-P concentration in SM treatments with mineral N were increased significantly, compared to those in SM treatment without mineral N (P<0.05). $PO_4$-P concentration in chemical fertilizer treatment showed trends similar to that of SS treatments with mineral 100 kgN/ha. The concentrations of $NO_3$-N $NH_4$-N and $PO_4$-P increased as the rate of mineral N application increased (P<0.05). The concentrations of $NO_3$-N $NH_4$-N and $PO_4$-P were highly elevated in the concentrated rainy season in the early stage among experimental period. The maximum $NO_3$-N $NH_4$-N and $PO_4$-P concentrations in the leaching water were 3.46 mg/L, 1.11 mg/L and 0.14 mg/L, respectively.

• Korean Journal of Materials Research
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• v.28 no.4
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• pp.241-246
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• 2018

$TaN_x$ film is grown by plasma enhanced atomic layer deposition (PEALD) using t-butylimido tris(dimethylamido) tantalum as a metalorganic source with various reactive gas species, such as $N_2+H_2$ mixed gas, $NH_3$, and $H_2$. Although the pulse sequence and duration are the same, aspects of the film growth rate, microstructure, crystallinity, and electrical resistivity are quite different according to the reactive gas. Crystallized and relatively conductive film with a higher growth rate is acquired using $NH_3$ as a reactive gas while amorphous and resistive film with a lower growth rate is achieved using $N_2+H_2$ mixed gas. To examine the relationship between the chemical properties and resistivity of the film, X-ray photoelectron spectroscopy (XPS) is conducted on the ALD-grown $TaN_x$ film with $N_2+H_2$ mixed gas, $NH_3$, and $H_2$. For a comparison, reactive sputter-grown $TaN_x$ film with $N_2$ is also studied. The results reveal that ALD-grown $TaN_x$ films with $NH_3$ and $H_2$ include a metallic Ta-N bond, which results in the film's higher conductivity. Meanwhile, ALD-grown $TaN_x$ film with a $N_2+H_2$ mixed gas or sputtergrown $TaN_x$ film with $N_2$ gas mainly contains a semiconducting $Ta_3N_5$ bond. Such a different portion of Ta-N and $Ta_3N_5$ bond determins the resistivity of the film. Reaction mechanisms are considered by means of the chemistry of the Ta precursor and reactive gas species.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.787-796
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• 2021

Nitrogen (N) is the most important element during the process of plant growth, and the quality of crops varies depending on the amount of nitrogen present. Most of the nitrogen is used for plant growth, but approximately 10 - 20% of Nitrogen is carried away by the wind in the form of NH₃. This volatilized NH₃ reacts with various oxides in the atmosphere to generate secondary particulate matter. To address this, the present study attempts to reduce NH₃ occurring in the soil using biochar at a specific pH. Biochar was used as a treatment with 1% (w·w^-1) of the soil, and urea was applied at different levels of 160, 320, and 640 kg·N·ha^-1. NH₃ generated in the soil was collected using a dynamic column and analyzed using the indophenol blue method. NH₃ showed the maximum emission within 4 - 7 days after the fertilizer treatment, decreasing sharply afterward. NH₃ emission levels were reduced with the biochar treatment in all cases. Among them, the best reduction efficiency was found to be approximately 25% for the 320 kg·ha^-1 + pH 6.7 biochar treatment. Consequently, in order to reduce the amount of NH₃ generated in the soil, it is most effective to use pH 6.7 biochar and a standard amount (320 kg·N·ha^-1) of urea.

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.23-27
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• 2002

To establish an in vitro mass production system of grape anthocyanin pigments through callus and cell suspension culture, the effects of nitrogen source and sucrose on fresh weight and anthocyanin production in cell suspension culture of 'Sheridan' grape level were studied. When the medium was devoid of $NO_3^-$, cell fresh weight was either remained stable (1% sucrose) or slightly decreased with culture time (2,3, and 4% sucrose). When $NH_4^-$ was lacking, 3% sucrose was most favorable for cell growth. When $NH_4^-$ was supplied as N source, the anthocyanin content of 2% sucrose containing medium was maintained 2 times higher than other levels till day 8 in culture, then that of 3 and 4% sucrose which peaked at day 12 thereafter. The anthocyanin content was low than $NO_3^-$-free media. Total anthocyanin content in $NH_4^-$-free medium was just about a half of that of $NH_4^+$ medium. Anthocyanin production of 2% sucrose in $NH_4^+$ medium was maintained about 3-fold till day 8, then decreased thereafter. In $NH_4^+$ medium, pH decreased gradually with final pH of 3.5 to 4.0, while pH in $NH_4^+$-free medium increased with final pH of 6.5 to 7.5.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.355-363
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• 2002

A demonstration plant was carried out to investigate the removal efficiency of $NH_3-N$ and $KMnO_4$ consumption depending on the existence of pre-chlorination for the ozonation and activated carbon process in the S water treatment plant which is located at the middle of Keum River. The averge removal efficiency of $KMnO_4$ consumption for $O_3/GAC$ processes with pre-chlorination and $O_3/BAC$ processes without pre-chlorination were 48.6% and 50% respectively. It is similar to removal effect of $KMnO_4$ consumption for GAC and BAC process depending on the existence of pre-chlorination. Otherwise, the removal of THMFP for GAC and BAC process was 58% and 68% respectively. $NH_3-N$ was not almost removed by sand filter and ozonation, but the average removal efficiency in the BAC process was about 31%. Especially, $NH_3-N$ was not almost removed by $O_3/BAC$ processes at the low temperature (below $$10^{\circ}C$$) in the winter season, $O_3/BAC$ processes have the advantage of removal of organic substance when it is compared to pre -chlorination followed by $O_3/GAC$ processes. Pre-chlorination followed by $O_3/GAC$ processes were required to remove $NH_3-N$ in the winter season because the removal of $NH_3-N$ was almost ineffective by $O_3/BAC$ process.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.589-596
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• 2021

Nitrogen applied to soil is highly prone to leaching and volatilization leading to gaseous emissions of nitrous oxide (N₂O) and ammonia (NH₃) which are of great environmental concern. Usage of biochar to reduce the discharge of nitrogen to the environment has attracted much interest in the recent past. Biochar is produced by pyrolyzing various biomasses under oxygen-limited conditions. Biochar is a carbonized material with high adsorptive powers for not only plant nutrients but also heavy metals. The objective of this study was to investigate the adsorption characteristics of NH₄-N onto biochar made from pine needles. The biochar was produced at various pyrolysis temperatures including 300, 400 and 500℃ and holding times of 30 and 120 minutes. The Langmuir isotherm was used to evaluate the adsorption test results. The chemical properties of the biochar varied with the pyrolysis conditions. In particular, the pH, EC and total carbon content increased with the increasing pyrolysis conditions. The rate of adsorption of NH₄-N by the biochar decreased with the increasing pyrolysis conditions. Of these conditions, biochar that was pyrolyzed at 300℃ for 30 minutes showed the highest adsorption rate of approximately 0.071 mg·g^-1. Thus, the use of biochar pyrolyzed at low temperatures with a short holding time can most efficiently reduce ammonia emissions from agricultural land.

• Korean Journal of Materials Research
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• v.7 no.7
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• pp.576-581
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• 1997

TDEAT(TI[N(C$_{2}$H$_{5}$)$_{2}$]$_{4}$)와 NH$_{3}$반응기체를 이용하여 MOCVD(Metal Organic Chemical Vapor Deposition)TiN 박막을 형성하였다. 반응기체들은 chamber내에 주입하기 전에 적절한 기상반응을 유도시켜 주었으며, TiN박막 형성에 미치는 예비혼합 효과를 관찰하였다. 두 반응기체의 예비혼합을 이용하여 낮은 탄소의 함유와 함께 -800$\mu$Ωㆍcm의 비교적 낮은 비저항을 나타내었다. 또한 NH$_{3}$의 유량 증가에 따라 도포성이 상당히 증가되고 있는데 이같은 도포성 향상 효과는 기상반응에 의하여 형성되는 중간상의 낮은 흡\ulcorner계수에 기인하는 것으로 여겨진다. QMS(Quadruple Mass Spectrometer)분석을 이용하여 두가지 경쟁적 반응을 포함한 전체 반응식을 제시하였다. TDEAT/NH$_{3}$혼합증착원의 경우 particle이 관찰\ulcorner지 않았으며 이것은 기상반응의 정도를 효과적으로 조절한데 기인하는 것으로 여겨진다. 결과적으로 반응기체의 예비혼합은 막질 및 도포성 개선과 함께 particle생성억제에 매우 효율적인 방법임을 알 수 있었다.다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.4-4
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• 2017

Atmospheric carbon dioxide enrichment ($eCO_2$) often increases soil nitrous oxide ($N_2O$) emissions, but the underlying mechanisms are not fully understood. Emerging evidence suggests that $eCO_2$ alters plant N preference in favor of ammonium ($NH_4{^+}-N$) over nitrate ($NO_3{^-}-N$). Yet, whether and how this attributes to the enhancement of $N_2O$ emissions has not been investigated. We examined the effects of $eCO_2$ on soil $N_2O$ emissions in the presence of two N forms ($NH_4{^+}-N$ or $NO_3{^-}-N$), using wheat (Triticum aestivum L.) as a model plant. Our results showed that N forms dominated $eCO_2$ effects on plant and microbial N utilization, and thus soil $N_2O$ emissions. Elevated $CO_2$ significantly increased the rate and the sum of $N_2O$ emissions by three to four folds when $NO_3{^-}-N$, but not $NH_4{^+}-N$, was supplied. Enhanced $N_2O$ emission was related to the reduced plant $NO_3{^-}-N$ uptake in wheat. We propose a new conceptual model in which $eCO_2$-inhibition of plant $NO_3{^-}-N$ uptake and/or $CO_2$-enhancement of soil labile C enhances the N and/or C availability for denitrifiers and increases the intensity and/or the duration of $N_2O$ emissions. Together, these findings suggest that to enhance plant N use efficiency and reduce $N_2O$ emission, crop breeding and management need to consider altered plant preference of N sources under future $CO_2$ scenarios.

• Applied Biological Chemistry
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• v.7
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• pp.45-52
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• 1966

This study was carried out to determine how the water soluble, the available $P_2O_5$ and urea-N would change in the course of time, when the mixtures of calcium superphosphate and urea with lime for fertilizer which occurred in Korea and largely contained calcium carbonate were made. Three kinds of materials, i. e., calcium superphosphate, urea and lime for fertilizer were used in this study. Three kinds of mixed fertilizer, i. e., A, B and C were made up by mixing these materials to satisfy the following formula. $$1)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_2H_2(PO_4)+H_2CO_3+NH_3$$ $$2)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+NH_3$$ $$3)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+CaCO_3+NH_3$$ A,B and C were placed in desiccators respectively a six month period. During the time of storage, the water soluble, the available phosphoric acid and urea-N were measured once a month, seven times with the control measurement. The results may be summarized as follows. 1. None of A, B and C showed any change in the urea-N with the lapse of time. This fact indicated that the combination of calcium superphosphate and urea with lime for fertilizer was not unfavourable. 2. A, B and C decreased in the amount of water soluble $P_2O_5$ with the passage of time. This fact indicated that the mixing of calcium superphosphate and urea with lime for fertilizer was unfeasible. 3. The available $P_2O_5$ in any of A,B and C did not undergo a change as time went by. This fact suggested that the combination of calcium superphate and urea with lime for fertilizer was favourable.

• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.38-43
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• 1977

The rate constant of the reaction of 3-or 4-substituted pyridines with benzyl benzenesulfonate in acetone at $35^{\circ}C$ were determined by an electric conductivity method. According to the Hammett plot, the rates were increased the electron donating ability at the $S_N2$ reaction of benzyl benzenesulfonate with pyridine and 4-$NH_2$ pyridine was correlated with ${\sigma}^+$ than Hammett ${\sigma}$ value. This result was explained that $NH_2$ group and N atom in pyridine are largely contribute by resonance. In Br$\"{o}$nsted plot, 4-amino and electron attracting group were deviated from the increasing part at linearity. It was considered to solvent effects on substituents. A mechanistic possibility was proposed to account for the results. Some activation parameters were also calculated.