• Journal of Plant Biology
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• v.14 no.4
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• pp.5-13
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• 1971

Pot and paddy field tests were conducted to study red discoloration of rice var. IR 667 leaves with reference to the leading Korean native variety Jinhung and Paldal, with the following results: 1. Minor elements such as Mn, Fe, B, Al, Ca and Si had no influence on the discoloration, but a supply of various soluble nitrogen compounds completely restricted it. The more prosperous the growth of IR 667 with nitrogen, the more severe the discoloration appears when nitrogen absorptin becomes limited. 2. Chlorotic pigments extracted from both IR 667 and Jinhung were compared spectrophotometrically, and found to have different spectral peaks. IR 667 had peak closer to red than Jinhung, indicating the characteristic of the variety. IR 667 was observed to be more sensitive to nitrogen deficiency than Jinhung or the other japonica variety. 3. It was concluded that all the factors limiting nitrogen supply for IR 667 growth, such as low nitrogen application, restriction of root respiration (low temperature, poor drainage, toxic gases or substances in the root zone, etc.) and pest injuries, would result in the appearance of the so-called red discoloration, because of the reduction in nitrogen uptake. Since, the discoloration of IR 667 is varietal characteristic when grown in Korea, control of it may be beneficial cultural practice in increasing grain yield, although the increased succeptibility to pests and a drop in the rate of maturity due to relatively high nitrogen level in the leaves may result in an unexpected drop in yield. It is anticipated that further exploration conducted from practical point of view will establish the relatioknships between the extent of red discoloration, nitrogen availability and grain yield in IR 667.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1153-1158
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• 1997

The powder characteristics of LiMn2O4 prepared by the citrate sol-gel method have been investigated. The optimum pH for the preparation of homogeneous citrate gel was calculated by the theoretical consideration of thermodynamic equilibrium constants for metal-citrate complexes and metal salts. The obtained citrate gel was prefired at 300 ℃ and calcined at 300-700 ℃ for 1 h. The obtained powders were characterized by TG/DSC, FT-IR spectrometer, X-ray diffractometer, SQUID magnetometer, SEM, and particle size analyzer. It was observed that the mixed phases of spinel LiMn2O4 and Mn3O4 were transformed into spinel LiMn2O4 phase and the vibrational bands due to the carbonate and nitrate were also disappeared over 400 ℃. At temperatures below 150 K, inverse molar susceptibilities of every sample began to show an antiferromagnetic ordering of Mn magnetic moments.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.06a
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• pp.64-65
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• 2004

• Journal of Magnetics
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• v.22 no.1
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• pp.7-13
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• 2017

The magnetoresistance (MR) properties of antiferromagnetic (AFM) IrMn based giant magnetoresistance-spin valve (GMR-SV) was investigated in view point of the artificial rotation effect of ferromagnetic (FM) layer in the plane induced by an applied field during the post annealing temperature. The MR curves measured with an azimuthal angle region of ${\phi}=0^{\circ}-360^{\circ}$ are depended on the annealing temperature and the magnetization easy axis of two free NiFe layers and two pinned NiFe layers in dual-type GMR-SV film. Especially, the annealing temperature and sample rotation angle(${\theta}$ ) maintained to the magnetic sensitivity (MS) of 1.4 %/Oe with an isotropic region angle of $110^{\circ}$ are $100^{\circ}C$ and $90^{\circ}$, respectively.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.443-450
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• 2014

Selective catalytic reduction of nitrogen monoxide by hydrogen ($H_2$-SCR of NO) over platinum catalysts impregnated on zirconia-incorporated silica ($ZrO_2-SiO_2$) and manganese oxide ($MnO_x$) was investigated. $Pt-MnO_x$ catalyst showed low conversions and low yields of $N_2O$ and $NO_2$ at $100{\sim}350^{\circ}C$. On the other hand, NO conversions over $Pt/ZrO_2-SiO_2$ were very high, but $N_2O$ was predominantly produced at $100-150^{\circ}C$ and the yield of $NO_2$ increased with temperature at $200-300^{\circ}C$, resulting in poor $N_2$ yields. $Pt-MnO_x/ZrO_2-SiO_2$ exhibited a small enhancement in $N_2$ yield at $100-150^{\circ}C$ due to the synergy of $MnO_x$ and $ZrO_2-SiO_2$. The surface composition and oxidation state of the catalyst components and the acidity of the catalysts were examined. IR spectra of the adsorption of NO and their subsequent reactions with hydrogen on these catalysts were also recorded. The variations of conversion and product yield according to the catalyst components in the $H_2$-SCR of NO were discussed in relation to their catalytic roles.

• Analytical Science and Technology
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• v.16 no.3
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• pp.218-225
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• 2003

Hydrogen Chloride is among the most problematic gases used in semiconductor process. It raises serious environmental and health problems due to its extreme toxicity. This study is to develop a method to effectively remove hydrogen chloride gas during the process by using various types of inorganic gas adsorption agents, which have not been attempted in the conventional methods. The removal efficiency of the gas was both qualitatively and quantitatively measured by a FT-IR spectrophotometer. The whole device for the measurement has been designed and built in our lab. The removal efficiencies of hydrogen chloride gas were compared between those tested resins; zeolite A, modified AgA zeolite, ZnO, and $AgMnO_3$. The experimental result revealed that ZnO showed the best efficiency that had removed 0.067 g of HCl per 1 g of the resin used.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.14.1-14.1
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.98-99
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• 2009

• Proceedings of the Korean Magnestics Society Conference
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• 2009.05a
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• pp.217-218
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• 2009

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.184-185
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• 2010