• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.6 no.1
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• pp.45-50
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• 1976

The author observed morphological change in palate development of rat embryo after irradiation of x-ray on the one side of the duplex uterus. The time-matings occured between 6 p.m. and 8 p.m. and all females with copulation plugs at 8 a.m. were isolated and properly marked for evidence of copulation. The lower left abdomen of mothers were exposed to x-radiation on the 7 1/2th, 9 1/2th, 11 1/2th day of gestation, respectively 150, 250, 350, 500rads. At 18 1/2th day of post-conception, the pregnant females were dissected and the contents of the two uteri examined. The translucent sample by Alizarin red S stain were prepared. The results were as follows; 1. The result that groups irradiated by 250rads and 350rads made marked difference in comparison with the control group suggests the x-ray to be a inducing factor of cleft palate. 2. At 11 1/2th day of gestation, incidence of cleft palate induced by x-irradiation was highest. 3. Mortality showed the highest frequency at 7 1/2th day of gestation and tended to decrease in according to increasing of age. 4. Morphology of cleft palate induced by x-irradiation showed similarity in comparison with those induced by other factors having reported ever.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.98-106
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• 2005

The construction cost index and the forecasting model of apartment house can be efficient for evaluating the validness of the fluctuating price, and for making guidelines for construction firms when calculating their profit. In this study the previous construction cost index of apartment house was improved, and the forecasting model based on X-12 ARIMA was developed. According to the result, during the last five years the construction cost, excluding labor expense, has risen approximately to 22.7%. And during next three years, additional 16.8% rise of construction cost is expected. Those quantitative results can be utilized for evaluating the apartment house's selling price in an indirection, and be helpful to understand the variation pattern of the price.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.9-14
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• 1965

The frequency of reicprocal translocation damage in males of D. melanogaster irradiated with X-rays was observed in this study. The frequencies were checked at four periods with two days intervals and duration spermatogenesis after irradiation. (1) Modification in the percentage of the reciprocal translocation damage were not obtained at interval after irradiated with 500r and 1500r of X-rays respectively. (2) In two experimental groups irradiated with 50-0r and 1500r of X-rays, the frequencies showing in the spermatogenesis were 0.50%(500r), 3.85%(1500r) in mature sperm, and 1.59%, 8.10% in the spermatocyte. (3) The frequency of reciprocal translocation between the Y and 3 rd chromosomes was the highest, but in accordance with dosage increase that of 2nd and 3rd chromosomes relatively increased from 9.34 % to 30.49% while decreased from 68.75% to 46.80% in the group of the Y and 3 rd chromosomes. (4) It was supposed that these modifications of the frequency were due to heavy damage of the 2nd chromosomes than other chromosomes in accordance with dosage increase. (5) Spontaneous reciprocal translocations involving the Y, 2nd and 3rd chormosomes was 0.23%.

• Journal of the Optical Society of Korea
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• v.12 no.2
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• pp.112-117
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• 2008

Single-mode propagation conditions of X-ray waveguides are investigated by numerical calculations in order to understand the importance of waveguide design parameters, such as core thickness and the optical constants of waveguide materials, on the transmission and coherence properties of the waveguide. The simulation code for mode analyzing is developed based on a numerical solution of the parabolic wave equation. The initial boundary value problem is solved numerically using a finite-difference scheme based on the Crank-Nicolson scheme. The E-field intensities in a core layer are calculated at an X-ray energy of 8.0 keV for air and beryllium(Be) core waveguides with different cladding layers such as Pt, Au, W, Ni and Si to determine the dependence on waveguide materials. The highest E-field intensity radiated at the exit of the waveguide is obtained from the Pt cladded beryllium core with a thickness of 20 nm. However, the intensity from the air core waveguide with Pt cladding reaches 64% of the Be-Pt waveguide. The dependence on the core thickness, which is the major parameter used to generate a single mode in the waveguide, is investigated for the air-Pt, and Be-Pt waveguides at an X-ray energy of 8.0 keV. The mode profiles at the exit are shown for the single mode at a thickness of up to 20 nm for the air-Pt and the Be-Pt waveguides.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3093-3097
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• 2013

The synthesis, X-ray crystallography, spectroscopic (IR, UV-vis), and electrochemical properties of the title compound, $[H_3O][Cr(dipic)_2][H_3O^+.Cl^-]$ (1), ($H_2dipic$ = 2,6-pyridinedicarboxylic acid), are reported. This complex crystallizes in the monoclinic space group Cc with a = 14.9006(10) ${\AA}$, b = 12.2114(8) ${\AA}$, c = 8.6337(6) ${\AA}$, ${\alpha}=90.00^{\circ}$, ${\beta}=92.7460(10)^{\circ}$, ${\gamma}=90.00^{\circ}$, and V = 1569.16(18) ${\AA}^3$ with Z = 4. The hydrogen bonding and noncovalent interactions play roles in the stabilization of the structure. In order to gain a better understanding of the most important geometrical parameters in the structure of the complex, atoms in molecules (AIM) method at B3LYP/6-31G level of theory has been employed.

• Korean Journal of Materials Research
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• v.18 no.8
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• pp.427-431
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• 2008

The mechanical property of a phosphore layer was investigated by measuring the resolution (LP/mm) and by positron annihilation spectroscopy and SEM. Image plate samples containing the phosphore layer were irradiated by X-rays in a hospital numerous times over a course of several years. The LP/mm values of a (Ba,Sr)FBr : Eu image plate irradiated by X-rays varied between 2.2 and 2.0 over a period of four years. Coincidence Doppler Broadening (CDB) positron annihilation spectroscopy was used to analyze defect structures. The S parameters of the samples from hospital use varied from 0.6219 to 0.6232. There was a positive relationship between the time of exposure to the X-rays and the S parameters. Most of the defects were found to have been generated by X-rays.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.8 s.251
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• pp.788-795
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• 2006

From the view of the environmental protection against the use of fossil fuels, the great of efforts have been exerted to find an effective method which is not only pollutant reduction but also high thermal efficiency. Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the hybrid effects of reburning and selective non-catalytic reaction (SNCR) on $NO_x/CO$ reduction from oxygen-enriched LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and $NO_x$ generation were observed to increase by oxygen-enriched combustion, but due to its hybrid effects of reburning and SNCR, $NOx/CO$ concentration in the downstream has considerably decreased.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.130-134
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• 2011

This study aims at the structural safety with optimum design of automotive bumper in order to minimize the maximum stress and displacement and reduce the minimum quantity of bumper material. As the forces of X and Y direction increase, equivalent stress and displacement increase. The displacement of X direction force increases more than 20% in comparison with Y direction force. But the equivalent stress of Y direction force increases more than 60% in comparison with X direction force. The mass of inner bumper becomes minimum and the mass of outer bumper becomes maximum when the force of 4000N is applied on the direction inclined at $45^{\circ}$ toward outer bumper. In 50% range of increase and decrease at X and Y direction force, the optimum forces of X and Y component becomes 2368.8N and 1538.8N respectively. And the masses of inner and outer polypropylene bumper become $3.3227{\times}10^{-2}kg$and $3.5538{\times}10^{-2}kg$respectively.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2375-2380
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• 2013

Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.1-11
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• 2004

This paper presents an implementation of smart antenna system channel card that executes modulation/demodulation. Operations and performances of modules of implemented channel card is confirmed and field test of channel card shows the performance of smart antenna systems. Based on the analysis obtained from the field test in cdma2000 1x environments which contains multipath lading, it is confirmed that smart antenna system channel card provide exact beampattern to the DOA and performance of proposed channel card has better FER by 5∼8 times, compared to 2 antenna diversity system.