• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.47-51
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• 2010

A powder, containing 80 percent of blue cobalt aluminate $(CoAl_2O_4)$ crystallites, was synthesized at $210 ^{\circ}C$ using a (metal nitrate-malonic acid-ammonium hydroxide-ammonium nitrate) system. The optimal amount of concentrated ammonia water and initial decomposition temperature were determined for the blue $CoAl_2O_4$ crystallites preparation. Three $CoAl_2O_4$ precursor pastes, corresponding to the various amounts of concentrated ammonia water, were prepared by evaporating the initial solutions in an electric furnace fixed at $80 ^{\circ}C$ under a vacuum of 25 torr. The initial solution was used to dissolve the starting materials. The powder with the maximum content (80%) of blue $CoAl_2O_4$ crystallites was prepared when the prepared precursor was decomposed at $210 ^{\circ}C$. The blue $CoAl_2O_4$ crystallite content in the prepared sample decreased with increasing initial decomposition temperature. For 0.2 mole of the $Al^{3+}$ ion, the chemical compositions of the precursor corresponded to molar ratios of 0.4, 1.40, 2.56 and 2.00 for the $Co^{2+}$ ion, malonic acid, ammonia and ammonium nitrate per mole of the $Al^{3+}$ ion, respectively. The blue $CoAl_2O_4$ crystallite content in the sample decreased with the amount of ammonia deviated from the optimal value. The characteristics of the powders were examined using X-ray diffraction, optical microscopy, Fourier transformation infrared spectroscopy and the Brunauer-Emmett-Teller technique.

• Proceedings of the Korean Society of Crop Science Conference
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• 1977.05a
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• pp.5.1-5.1
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• 1977

• Proceedings of the Korean Fiber Society Conference
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• 1993.06a
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• pp.59-59
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• 1993

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.242-252
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• 1984

A port experiment was conducted to compare the effect of chemical forms of nitrogen fertilizers on the rice growth and soil characteristics. The nitrogen fertilizers used for this study were ammonium sulfate, ammonium nitrate, ammonium chloride and urea. The results are summarized as follows. 1. The differences in pH of the soil and surface water between treatments during the first week after fertilizer application were great and the pH values were in the order of urea > ammonium nitrate > ammonium sulfate > ammonium chloride treatment. However the differences were insignificant after the first week. 2. The differences in pH of the air-dried soil somewhat increased and pH values were in the order of urea > ammonium nitrate > ammonium chloride > ammonium sulfate treatment. 3. Sulfur contents of the soil and the rice leaf and N content of the rice leaf were highest when ammonium sulfate was applied. But there were few differences between the treatments in total N content of the soil and in P, K, Ca and Mg contents of the soil and the rice leaf. 4. Number of tillers and dry matter weight of the rice plant were highest in ammonium sulfate plot throughout all the growing stages. 5. Number of panicle per hill was highest in ammonium sulfate plot, and this brought the highest grain yield in ammonium sulfate plot. The lowest grain yield in ammonium nitrate plot resulted from the lowest number of panicle per hill and ripened grain ratio.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.407-412
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• 1985

The effect of potash applied with different sources of nitrogen was experimented in pot soil culture on chinese cabbage (Brassica Pekinensis Rupr, Var. Fall 1984: Sammi Garak, Spring 1985: Jungang Summer lab.) in the fall, 1984 and in the spring, 1985. Results obtained are as follows; 1. Ammonium nitrate increased the yield of chinese cabbage more than urea did, and the effect of yield increase by ammonium nitrate was greater in the fall cultivation than in the spring. 2. The yield of chinese cabbage was positively correlated with the contents of K in the first (May 17, 1985) and second (June 9, 1985) thined cabbages (dry matter). It was also positively correlated with $NO_3-N$ content of the first thined cabbage and with K/Ca+Mg m.e, ratio of outer leaves of the harvested (June 27, 1985) cabbage, but negatively affected with Mg content of the outer leaves. 3. Correlations between K and $NO_3-N$ contained in the dry matter of first and second thined, and inner leaves of the harvested cabbage were learnt to be $r;0.9998^{**}$, r;0.4439, and $r;-0.7135^*$ respectively. The higher $NO_3-N$ content in the inner leaves of harvested cabbage was observed at K omitted ammonium nitrate plot where K was deficient, Ca and Mg contents were low. 4. The nutrient absorption and growth of chinese cabbage may take the following process. Nitrate nitrogen increases vegetative growth of the plant with enhanced K uptake and movement in to inner leaves and followed by replacement of Ca uptake and finally Mg uptake and its movement in to inner leaves.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.166-174
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• 2016

In order to find an efficient bacterial strain that can carry out nitrification and denitrification simultaneously, we isolated many heterotrophic nitrifying bacteria from wastewater treatment plant. One of isolates NS13 showed high removal rate of ammonium and was identified as Alcaligenes faecalis by analysis of its 16S rDNA sequence, carbon source utilization and fatty acids composition. This bacterium could remove over 99% of ammonium in a heterotrophic medium containing 140 mg/L of ammonium at pH 6-9, $25-37^{\circ}C$ and 0-4% of salt concentrations within 2 days. It showed even higher ammonium removal at higher initial ammonium concentration in the medium. A. faecalis NS13 could also reduce nitrate and nitrous oxide by nitrate reductase and nitrous oxide reductase, respectively, which was confirmed by detection of nitrate reductase gene, napA, and nitrous oxide reducase gene, nosZ, by PCR. One of metabolic intermediate of denitrification, $N_2O$ was detected from headspace of bacterial culture. Based on analysis of all nitrogen compounds in the bacterial culture, 42.8% of initial nitrogen seemed to be lost as nitrogen gas, and 46.4% of nitrogen was assimilated into bacterial biomass which can be removed as sludge in treatment processes. This bacterium was speculated to perform heterotrophic nitrification and aerobic denitrification simultaneously, and may be utilized for N removal in wastewater treatment processes.

• Journal of the Korean Chemical Society
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• v.41 no.12
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• pp.661-665
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• 1997

Recently ADN was disclosed to replace AP or AN as a solid oxidizer. 3-N,N-Dinitraminopropanitrile, a key intermediate in the preparation of ADN, was synthesized from bis(2-cyanoethyl)amine by the sequence: nitration of bis(2-cyanoethyl)amine followed by decyanoethylation by base and the second nitration with NO2BF4. 3-N-Nitro-bis(2-cyanoethyl)amine could also be obtained by the oxidation of the corresponding N-nitroso compound.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.04a
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• pp.205-211
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• 1997

최근 유도무기 분야에서 많이 사용되고 있는 가스발생기는 온도가 낮고, 독성이나 부식성이 없는 연소 가스를 요구하고 있기 때문에 산화제로 Ammonium Nitrate(AN)를 주로 사용하고 있다. 그러나 순수한 AN은 온도에 따라 상이 변하는 단점이 있기 때문에 Phase Stabilized Ammonium Nitrate(PSAN)을 사용하고 있으며, 일반적으로 PSAN은 AN과는 다른 연소특성을 갖는다. 본 연구에서는 가스발생기용 추진제의 조성을 연구하면서, 상안정제로 $KNO_3$와 $KCIO_4$을 사용하여 자체적으로 제조한 PSAN들과 ZnO=3%인 PSAN을 사용하여 얻은 추진제의 연소특성을 고찰하였고, 연소촉매를 사용하거나 RDX나 소량의 AP를 사용하여 보다 다양한 연소속도를 갖는 추진제를 제조할 수 있었다.

• Journal of Industrial Technology
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• v.5
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• pp.9-14
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• 1985

The blast-induced ground vibrations is one of the most important factors which is considered to design blasting patterns in urban excavation. To compare with vibration level of different explosives, peak particle velocity of each explosive was measured. The results are summerized as follows. 1. Among the three kinds of explosives, the largest vibration was obtained from the gelatine dynamite, while the smallest was blasting of ammonium nitrate. 2. The vibration levels of ammonium nitrate and slurry explosive were smaller about 35%, 20% respectively than that of gelatine dynamite.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.291-298
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• 1995

An intensive field study was carried out during Aug. 1993 in Seoul to study the characteristics of summertime visibility and diurnal trend of ionic composition of ambient particles. A transmissometer, nephelometer with heated and unheated inlets, PM3 fine particle sampler, and cascade impactor were used to measure optical and particle properties of ambient air. During this study period, a weak smog episode has occurred. Light scattering by particles is the most dominant factor on total light extinction. The effect of light absorption by particles in Seoul is much higher than other major cities in U.S.A. throughout the summer and fall with relatively constant values. The effect of water on $b_{sp}$ was small during the period. The particle size distribution shows a typical bimodal one. Sulfate, ammonium, chloride, and nitrate are the major chemical species in fine fraction aerosols, about 30% of toral mass concentration. Concentraion of sulfate is higher during the daytime while those of nitrate and chloride are higher during the nighttime. Ammonium concentration is constant through the daytime.