• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1275-1277
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• 1995

We designed and constructed an extremly high power s-band traveling wave resonator for the test of high power microwave components using 80MW pulsed klystron with $4{\mu}s$ pulse width. The 10dB directional coupler for the input power coupling was used, and the ring consists of phase shifter, tuner, H-band, and other microwave components. The designed total electrical length of the system is 10 times of the waveguide wavelength, ${\lambda}_g$=15.3cm, and the measured total insertion loss is 0.15dB. The low power test measurment showed the power multiplication of 14.69. The design goal is to achieve the peak power of 300MW, pulse width $4{\mu}s$ with 30 pulse repetition rate. In this article we discuss the treveling wave resonant ring constructed at the PAL laboratory together with the test results.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.177-183
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• 2002

The study was designed to investigate the aspects of the goblet cell of the oviduct in laying Korean ring-necked pheasants by histochemical methods (PAS, alcian blue-PAS, alcian blue pH 2.5, alcian blue pH 1.0, and aldehyde fuchsin-alcian blue stain). Twelve laying Korean ring-necked pheasants were used. The results were summarized as follows. The goblet cell of the oviduct of the Korean ring-necked pheasant contained sulfated acid mucosubstances and neutral mucosubstances in the infundibulum. The compounds of sulfated acid mucosubstances, nonsulfated acid mucosubstances, and neutral mucosubstances are present in goblet cells of the magnum, vagina and openings of the tubular gland of the uterus of the oviduct in the Korean ring-necked pheasant. The goblet cell of the isthmus and uterus of the oviduct of the Korean ring-necked pheasant contained neutral mucosubstances except openings of the tubular gland of the uterus. The histochemical characteristics of secretory granules of goblet cells in oviduct of the Korean ring-necked pheasant were not related to the position of eggs in oviduct.

• Journal of the Korean Vacuum Society
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• v.8 no.1
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• pp.43-50
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• 1999

We have studied the alignment and the lattice quality of hexagonal rings of h-BN films synthesized by ion beam assisted deposition (IBAD) method. Boron was e-beam evaporated at 1.5 $\AA$/sec and nitrogen gas was ionized using end-hall type ion gun at 60, 80, and 100 eV, respectively. Substrate was either not heated or heated at 200, 400, 500, and $800^{\circ}C$, respectively. As nitrogen ion energy increases, c-axes of hexagonal rings tend to align parallel to the substrate, which is explained by larger compressive stress at higher ion energies. Alignment of c-axis increases with temperature and shows maximum around $400^{\circ}C$. The lattice quality of hexagonal rings improves with temperature. Such behaviors can be understood from two counter trends of increasing the atomic mobility and decreasing compressive stress with temperature. Hardness of h-BN films shows the same trend with the alignment of c-axis. Ion beam assisted deposition method seems to be effective for aligning hexagonal rings and optimizing h-BN properties.

• Transactions of Materials Processing
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• v.19 no.6
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• pp.329-336
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• 2010

Ring forging process is more appropriate for high-length and thin walled ring, because it utilizes the forging press and hence does not require heavy-duty ring rolling mill. Although ring forging process is very simple and economic for facilities, the process is not efficient because of multi-forging-step and low material utilization. An effective ring forging process is developed using a hollow ingot. When a hollow ingot is used with a workpiece, the ingot can be forged into a final ring without multi-stage pre-forging process, such as, cogging, upsetting, and piercing, etc.. Finally it has advantages of the material utilization and process improvement because a few reheating and forging process are not necessary to make workpiece for ring forging. The important design variables are the applied plastic deformation energy to eliminate cast structure and make uniform properties. In this study, the mechanical properties after forging of hollow cast ingot were investigated from the experiment using circumferential sectional model. Also, the effects of process variables were studied by FEM simulation on the basis of thermo-visco-plastic constitutive equation. Applied strain is different at each position in length direction because diameter of hollow ingot is different in length direction. The different strain distribution become into a narrow gap by additional plastic deformation during diameter extension process.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.228-229
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• 2008

In this study, we propose an effective method to improve the clarity and period of the beat in a ring structure. Ring is an simplified model of a Korean bell, in which beating vibration and sound are very important features. An equivalent ring theory is applied and finite element analysis on the equivalent ring is performed to determine the condition of the asymmetric element for the clear and proper period beat. The clarity and the period of the beat are improved by attacking asymmetric mass and decreasing local thickness. Using the equivalent ring, the amount and position of the local variation for the required beat condition are determined and the results are verified by experiment.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.663-666
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• 1999

The 4-methylene-1,3-dioxolane(4-MDO) derivatives with dimethoxyphenyl group on the 2-position of 1,3-dioxolane ring, 2-(x,y-dimethoxyphenyl)-4-MDO derivatives (x,y=2,3(1b), 2,4(2b), 2,5(3b) and 3,4(4b)) were prepared by acelalizationof the corresponding benzaldehyde with 3-chloro-1,2-propanediol, followed by dehydrochlorination. 2-(Dimethoxy)phenyl-4-MDO derivatives underwent polymerization wiht ring opening as will as cyclization reaction to afford a mixture of the ring-opened polymer and 3(2H)-dihydrofuranone derivative with boron trifluoride as a cationic catalyst. Both the methylene group and 1,3-dioxolane ring were participated in the reaction with cationic catalyst. The key intermediate of the polymerization is a benzyl cation generated by ring opening, and the cyclization reaction proceed via proton addition to oxygen atom of 1,3-dioxolane ring.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.126-131
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• 1996

The effects of various synthetic benzimidazole derivatives on gastric H^+/K^+$ATPase activity in vitro were examined. The results showed that the effects of substituents on the benzimidazole ring were not significant. However, replacement of sulfoxide connecting two ring systems to sulfide resulted in a completely inactive compound in vitro, suggesting the essential role of sulfoxide group in the inhibition. In addition, compounds with 5 or 6-membered oxacyclic substituents attached to the pyridine ring displayed the most effective inhibitory activity. Among these derivatives, AU-47 was the most potent, and detailed mechanistic studies with the compound were carried out. AU-47 inhibited gastricH^+/K^+$ATPase in a concentration and time dependent manner with 50% inhibition at $6\muM$. The presence of sulfhydryl reducing agents or substrate analogue protected H^+/K^+$ATPase from the inactivation. The inhibition by AU-47 was potentiated by acid pretreatment of the compound, suggesting the structural conversion of AU-47 into a more active intermediate which was favored in acidic condition. Consistent with in vitro results, AU-47 inhibited in vivo gastric acid secretion. The results suggest that AU47 is a relevant candidate for the development of new antiulcer agent.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.156-156
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• 2023

Salinity is a major abiotic stress that limits rice productivity in many regions of the world. In order to develop salt stress tolerant rice plants, genetic engineering is a promising approach. We characterized the molecular function of rice C3H2C3 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under salinity conditions, OsRFPH2-3-overexpressing plants exhibited higher chlorophyll, proline, SOD, POD, CAT, and soluble sugar contents and lower H₂O₂ accumulation than wild-type plants, supporting transgenic plants with enhanced salinity tolerance phenotypes. OsRFPH2-3-overexpressing plants exhibited low Na+ accumulation and Na+/K+ ratios in their roots. Theses results suggest that overexpression of OsRFPH2-3 can make plant insensitivity about salinity conditions.

• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1115-1123
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• 2016

Let $D{\subseteq}E$ be an extension of integral domains with characteristic zero, I be a nonzero proper ideal of D and let H(D, E) and H(D, I) (resp., h(D, E) and h(D, I)) be composite Hurwitz series rings (resp., composite Hurwitz polynomial rings). In this paper, we show that H(D, E) satisfies the ascending chain condition on principal ideals if and only if h(D, E) satisfies the ascending chain condition on principal ideals, if and only if ${\bigcap}_{n{\geq}1}a_1{\cdots}a_nE=(0)$ for each infinite sequence $(a_n)_{n{\geq}1}$ consisting of nonzero nonunits of We also prove that H(D, I) satisfies the ascending chain condition on principal ideals if and only if h(D, I) satisfies the ascending chain condition on principal ideals, if and only if D satisfies the ascending chain condition on principal ideals.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.250-257
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• 2015

The crystal structure of the potential active 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile ($C_{19}H_{16}N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=6.6869 (8) ${\AA}$, b=15.8326 (19) ${\AA}$ and c= 15.237 (2) ${\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=100.663^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...N and C-H...O hydrogen bond interaction.