• Title/Summary/Keyword: Bismuth(Bi)

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Effects of Self-Made Bismuth Shield Installation on Entrance surface Dose Reduction during Endovascular Treatment of Cerebral Aneurysms (뇌동맥류 코일 색전술시 자체 제작한 Bismuth 차폐체 설치의 피부선량 감소 효과)

  • Kim, Jae-Seok;Kim, Young-Kil;Choi, Jae-Ho
    • Journal of the Korean Society of Radiology
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    • v.13 no.2
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    • pp.175-183
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    • 2019

  • Cerebral nervous system intervention has been reported frequently due to radiation exposure such as blistering of the skin, hair loss, and erythema due to prolonged procedures. By applying ergonomically manufactured Bismuth (atomic number 83; Bi) shield to endovascular treatment of cerebral aneurysms, we aimed to minimize radiation exposure of scalp and lens from medical radiation exposure. The measurement site was the posterior part of the head, bilateral temporal part, bilateral quadriceps part, nose part, and the measuring part was attached to the optically stimulated Luminescence dosimeter (OSLD) Before and after the use, the entrance surface dose was compared and analyzed. The average entrance surface dose of group A (unshield) was 92.44 mGy, and group B was measured at 67.55 mGy. The average decrease in Group B was 26.92% compared to Group A. The entrance surface dose mean of the occipital region was measured at 146.08 mGy B group at 103.23 mGy and decreased by an average of 29.32% in group B compared to group A. The average entrance surface dose of the bilateral temporal part was measured in group A at 101.90 mGy group B at 72.69 mGy and decreased by an average of 28.67% in group B compared to group A. The average entrance surface dose for bilateral quadriceps part was measured at 27.51 mGy group B at 21.39 mGy and averaged 22.26% less in group B than group A. It is believed that the use of bismuth shields will be an alternative to reducing radiation disturbance due to temporary hair loss and other stochastic effects that may occur after the endovascular treatment of cerebral aneurysms procedure.

  • https://doi.org/10.7742/jksr.2019.13.2.175 인용 PDF KSCI HTML

Ferroelectric Properties of Bi3.25La0.75 Ti3O12 Thin Films with Excess Bi Contents for Non-Volatile Memory Device Application (비휘발성 메모리 소자응용을 위한 과잉 Bi 첨가에 따른 BLT 박막의 강유전 특성)

  • 김경태;김창일;강동희;심일운
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.9
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    • pp.764-769
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    • 2002

  • The effect of excess Bi contents on the ferroelectric properties of B $i_{3.25}$ L $a_{0.75}$ $Ti_3$ $O_{12}$ (BLT) thin films has been investigated. Bismuth lanthanum titanate thin films with excess Bi contents were prepared onto Pt/Ti/ $SiO_2$/Si substrate by metalorganic decomposition (MOD) technique. The structure and morphology of the films were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. From the XRD analysis, BLT thin films show polycrystalline structure and the layered-perovskite phase was obtained over 10% excess of Bi contents. As a result of ferroelectric characteristics related to the Bi content of the BLT thin film, the remanent polarization and dielectric constant decreased with increasing over Bi content of 10% excess. The BLT film with Bi content of 10% excess was measured to have a dielectric constant of 326 and dielectric loss of 0.024. The BLT thin films showed little polarization fatigue test up to 3.5$\times$10$^{9}$ bipolar switching cycling.

  • https://doi.org/10.4313/JKEM.2002.15.9.764 인용 PDF KSCI

Characteristics of Tensile Strength and Corrosion Resistance of Lead- free Brass Containing 1 wt.% of Bi (1 wt.% Bi 함유 무연황동의 인장강도와 내식특성에 대한 연구)

  • Joo, Y.S.;Lee, S.B.;Kim, S.Y.;Joo, C.S.;Jung, B.H.
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.3
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    • pp.133-139
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    • 2011

  • This study has been investigated for tensile properties with lead-free brass containing 1 wt.% of Bi. And also characteristic of corrosion resistance was analyzed by polarization test. An increase of tempering temperature was found to tend to decrease tensile strength, and percentage of elongation was shown to be the lowest value at $300^{\circ}C$. On the other hand, the elongation was increased with an increase of tempering temperature after $300^{\circ}C$. The change of mechanical properties was closely related with the content and shape of acicular Witmanst$\ddot{a}$tten ${\alpha}$ formed at the interface of ${\beta}$ phase as well as in ${\beta}$ phase. Tensile strength had a tendency to be decreased with an increase of test temperature. The elongation was shown to be the lowest value at around $300^{\circ}C$, while it began to increase as test temperature rose after $300^{\circ}C$. It might be speculated that the reason that elongation was decreased was found to form bismuth film at the interface of ${\alpha}/{\beta}$ phase leading to be easily brittle when loaded by tensile stress. The lead-free brass containing 1 wt.% of Bi had similar characteristic of corrosion resistance with a free-cutting brass with 3.4 wt. % of Pb in spite of higher fraction of ${\beta}$ phase.

  • https://doi.org/10.12656/jksht.2011.24.3.133 인용 PDF KSCI