• Title/Summary/Keyword: Central X-ray

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The Study of Appropriate X-ray Tube Angle for the Anterior-posterior Chest Radiography Using S-align Function (S-align 기능을 이용한 흉부 전·후 방향 검사 시 적절한 X선관 각도에 관한 연구)

  • Park, Myeong-Ju;Joo, Young-Cheol;Kim, Min-Suk;Yuk, Jeong-Won;Kim, Han-Yong;Kim, Dong-Hwan
    • Journal of radiological science and technology
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    • v.45 no.4
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    • pp.299-304
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    • 2022
  • This study uses the 'S-align' function to present a reference value of the X-ray tube angle for the realization of an image similar to that of the chest PA image during chest AP radiography. This study targeted dummy phantom and used a 17"×17" DR image receptor. The irradiation conditions were 110 kVp, 160 mA, 50 ms, and the distance between the central X-ray and the image receptor was set to 180 cm and 110 cm, respectively. The end of the catheter was placed at the 11th thoracic height to indicate the nasogastric tube. In the case of lung apex length measurement, the mean value of measurement was 30.53±0.47 in PA. T 0°, TCA 5~25°, TCE 5~15° were 21.07±0.29, 27.60±0.21, 34.13±0.44, 39.86±0.31, 45.96±0.61 mm, 54.13±0.37 mm, 16.16±0.46 mm, 9.81±0.35 mm, 2.75±0.30 mm, respectively. For the depth of the catheter end, the average value measured at PA was 6.70±0.31 mm. T 0°, TCA 5~25°, TCE 5~15° were 15.72±0.38 mm, 24.10±0.50 mm, 29.24±0.86 mm, 34.35±0.35 mm, 41.06±1.08 mm, 48.07±0.38 mm, 12.85±0.25 mm, 7.92±0.36 mm, 3.01±0.39 mm, respectively. The length of the lung apex was similar to that of chest PA when the angle of incidence was adjusted from 5° to 10° in the leg direction, and the depth of the catheter tip was most similar when the X-ray tube angle was incident at 10° in the head direction. Therefore, To change the X-ray tube angle according to the purpose of the examination during the chest AP radiography using 'S-align' function is considered necessary.

Comparative Study and Electrochemical Properties of LiFePO4F Synthesized by Different Routes

  • Huang, Bin;Liu, Suqin;Li, Hongliang;Zhuang, Shuxin;Fang, Dong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2315-2319
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    • 2012
  • To improve the performance of $LiFePO_4F$, a novel sol-gel process is developed. For comparison, ceramic process is also implemented. From X-ray diffraction results we know that each sample adopts a triclinic $P{\bar{1}}$ space group, and they are isostructural with amblygonite and tavorite. The scanning electron microscope images show that the homogeneous grains with the dimension of 300-500 nm is obtained by the sol-gel process; meanwhile the sample particles obtained by ceramic process are as big as 1000-3000 nm. By galvanostatic tests and at electrochemical impedance spectroscopy method, the sample obtained by sol-gel process presents better electrochemical properties than the one obtained by ceramic process.

Abell 2261: a fossil galaxy cluster in a transition phase

  • Kim, Hyowon;Ko, Jongwan;Kim, Jae-woo;Smith, Rory;Song, Hyunmi;Hwang, Ho Seong
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.33.2-33.2
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    • 2018
  • Fossil galaxy cluster has a dominant central elliptical galaxy (${\Delta}M12$ >2 in 0.5Rvir) embedded in highly relaxed X-ray halo, which indicates dynamically stable and passively evolved system. These features are expected as a final stage of the cluster evolution in the hierarchical structure formation paradigm. It is known that Abell 2261(A2261 hereafter) is classified as a fossil cluster, but has unusual features such as a high central X-ray entropy (i.e., non-cool core system), which is not expected in normal fossil clusters. We perform a kinematic study with a spectroscopic data of 589 galaxies in the A2261 field. We define cluster member galaxies using the caustic method and discover a new second bright galaxy at ~1.5 Rvir (nearly the splash-back region). It implies the current fossil state of the cluster can break in the near future. In addition, with three independent substructure finding methods, we find that A2261 has many substructures within 3 Mpc from the center of the cluster. These findings support that A2261 is not in a dynamically stable state. We argue that A2261 is in a transitional phase of dynamical evolution of the galaxy cluster and maybe previously defined fossil cluster does not mean the final stage of the evolution of galaxy clusters.

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The Defect Characterization of $Gd_2O_2S$: Tb Crystals by Positron Annihilation Spectroscopy (양전자 소멸 분광법을 이용한 $Gd_2O_2S$ : Tb 결함 특성)

  • 이종용;김창규
    • Journal of the Korean Vacuum Society
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    • v.13 no.2
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    • pp.92-98
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    • 2004
  • DBPAS has been used to characterize atomic size defect structures in materials. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. As the samples were exposed by X-ray increasing the exposed doses from 3, 6, and 9 Gy with 6 MV and 15 MV, respectively and also irradiated by X-ray as the medical applications used for in 0, 2, 4 and 6 years. The S-parameter values were increased as increasing the exposed time and the energies, that indicated the defects generate more. The S-parameters of the samples with medical treatment is varied from 0.4932 to 0.4956.

SEM/EDS Analysis of the Enamel in Mesiodens (정중 과잉치 법랑질의 SEM/EDS 분석)

  • Oh, Nakyeong;Lee, Jaesik;Nam, Soonhyeun;Kwon, Taeyub;Kim, Hyunjung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.46 no.1
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    • pp.101-110
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    • 2019
  • The aim of this study was to evaluate and compare the microstructural properties and mineralization quality of mesiodens with permanent and primary central incisors. Fifteen mesiodens, permanent and primary central incisors were collected. The enamel rod diameter and enamel thickness were observed and measured using field emission scanning electron microscope (FE-SEM). Chemical composition of the enamel was analyzed using energy dispersive X-ray spectrometer (EDS). The measurements were then assessed using the one-way ANOVA and Tukey test. There was no statistically significant difference in the enamel rod diameter between mesiodens and permanent central incisors. However, enamel rods of primary central incisors were smaller than remaining two groups. The thickness of enamel was thick in order of permanent central incisors, mesiodens, primary central incisors. In the composition analysis using EDS, there was no difference in the Ca/P ratio and Ca/C ratio between mesiodens and permanent central incisors, but small in primary central incisors. In conclusion, the microstructural properties of mesiodens were more similar to those of permanent central incisors compared to primary central incisors. Futher, the mineralization quality of mesiodens did not differ significantly from that of permanent central incisors.

Adsorption of Nucleotides on ${\beta}$-Cyclodextrin Derivative Grafted Chitosan

  • Xiao Jian-Bo;Yu Hong-Zhu;Xu Ming;Chen Xiao-Qing
    • Macromolecular Research
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    • v.14 no.4
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    • pp.443-448
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    • 2006
  • A novel ${\beta}$-cyclodextrin derivative (CCD-C) was synthesized with chitosan and carboxymethyl-${\beta}$-cyclodextrin. Its structure was characterized by elemental analysis, infrared spectra analysis, and X-ray diffraction analysis. The adsorption properties for guanosine 5'-monophosphate, cytidine 5'-monophosphate and uridine 5'-monophosphate were studied. Experimental results demonstrated that CCD-C had higher adsorption capability for guanosine 5'-monophosphate, and that the adsorption capacity for guanosine 5'-monophosphate was 74.20mg/g. The adsorption capacity was greatly influenced by pH, time and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of ${\beta}$-cyclodextrin for guanosine 5'-monophosphate. This novel derivative of chitosan is expected to have wide applications in the separation, concentration and analysis of nucleotides in biological samples.

Magnetic Interaction in FeCo Alloy Nanotube Array

  • Zhou, D.;Wang, T.;Zhu, M.G.;Guo, Z.H.;Li, W.;Li, F.S.
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.413-416
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    • 2011
  • An array of FeCo nanotubes has been successfully fabricated in the pores of porous anodic aluminum oxide (AAO) templates by wetting templates method. The morphology and structure of the nanotube array were characterized by scanning electron microscopy, transmission electron microscopy and x-ray diffraction. The average diameter of the nanotubes was about 200 nm, and the length was more than 10 ${\mu}m$. Vibrating sample magnetometer and superconducting quantum interference device were used to investigate the magnetic properties of the nanotube array. Interaction between the nanotubes has been found to be demagnetizing as expected and the switching field distribution is broad.

Structure-based Functional Discovery of Proteins: Structural Proteomics

  • Jung, Jin-Won;Lee, Weon-Tae
    • BMB Reports
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    • v.37 no.1
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    • pp.28-34
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    • 2004
  • The discovery of biochemical and cellular functions of unannotated gene products begins with a database search of proteins with structure/sequence homologues based on known genes. Very recently, a number of frontier groups in structural biology proposed a new paradigm to predict biological functions of an unknown protein on the basis of its three-dimensional structure on a genomic scale. Structural proteomics (genomics), a research area for structure-based functional discovery, aims to complete the protein-folding universe of all gene products in a cell. It would lead us to a complete understanding of a living organism from protein structure. Two major complementary experimental techniques, X-ray crystallography and NMR spectroscopy, combined with recently developed high throughput methods have played a central role in structural proteomics research; however, an integration of these methodologies together with comparative modeling and electron microscopy would speed up the goal for completing a full dictionary of protein folding space in the near future.

HALO EMISSION OF THE CAT’S EYE NEBULA, NGC 6543: SHOCK EXCITATION BY FAST STELLAR WINDS

  • Hyung, Siek;Lee, Seong-Jae
    • Journal of Astronomy and Space Sciences
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    • v.19 no.3
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    • pp.173-180
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    • 2002
  • Images taken with the Chandra X-ray telescope have for the the first time revealed the central, wind-driven, hot bubble (Chu et al. 2001), while Hubble Space Telescope (HST) WFPC2 images of the Cat's Eye nebula, NGC 6543, show that the temperature of the halo region of angular radius ~ 20", is much higher than that of the inner bright H II region. With the coupling of a photoionization calculation to a hydrodynamic simulation, we predict the observed 〔O III〕 line intensities of the halo region with the same O abundance as in the core H II region: oxygen abundance gradient does not appear to exist in the NGC 6543 inner halo. An interaction between a (leaky) fast stellar wind and halo gas may cause the higher excitation temperatures in the halo region and the inner hot bubble region observed with the Chandra X-ray telescope.

Evolution of Spin and Superorbital Modulation in 4U 0114+650

  • Hu, Chin-Ping;Ng, Chi-Yung;Chou, Yi
    • Journal of Astronomy and Space Sciences
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    • v.33 no.3
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    • pp.173-176
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    • 2016
  • We report on a systematic analysis of the spin and superorbital modulations of the high-mass X-ray binary 4U 0114+650, which consists of the slowest spinning neutron star known. Utilizing dynamic power spectra, we found that the spin period varied dramatically during the RXTE ASM and Swift BAT observations. This variation consists of a long-term spin-up trend, and two ~1,000 day and one ~600 day random walk epochs previously, MJD 51,000, ~MJD 51,400-52,000, and ~MJD 55,100-56,100. We further found that the events appear together with depressions of superorbital modulation amplitude. This provides evidence of the existence of an accretion disk, although the physical mechanism of superorbital modulation remains unclear. Furthermore, the decrease of the superorbital modulation amplitude may be associated with the decrease of mass accretion rate from the disk, and may distribute the accretion torque of the neutron star randomly in time.