• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.94-97
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• 2005

Bismuth high Tc superconducting thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra low growth rate, and sticking processing of the respective elements are evaluated. The sticking processing of bismuth element in bismuth high Tc superconducting thin film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about $730^{\circ}C$ and decreased linearly over about $730^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, $Bi_2O_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the bismuth phase formation in the co-deposition process.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.369-371
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• 2018

The uniform and monodisperse bismuth nanospheres were successfully prepared by simple and convenient solvothermal method. The bismuth nitrate was reduced by ethylene glycol at $150-200^{\circ}C$ for 20-30 hrs. The nanospheres were characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The dispersivity of bismuth nanospheres was investigated using optical microscope. The optimum reaction conditions to prepare the uniform bismuth nanospheres with a narrow diameter range was investigated. The results indicate that the monodisperse bismuth nanospheres prepared at $200^{\circ}C$ possess sizes ranging from 100-200 nm. The formation mechanism of the bismuth nanospheres was hypothesized.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.779-785
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• 2019

By applying an ergonomically developed Bismuth shield to the endovascular treatment of cerebral aneurysm the radiation dose of the scalp and lens from the medical radiation exposure was reduced. The enrtance surface dose was analyzed by measuring the occipital parts, bilateral temporal parts, bilateral quadriceps, and nasal tip of the developed bismuth shield using a photostimulable fluorescence dosimeter before (Group A) before use (Group B). Signal to noise ratio (SNR) and contrast to noise ratio (CNR) analysis were used to evaluate the image quality when Bismuth shielding was used. The mean entrance surface dose of A group and B group was 26.92% lower than that of A group. The analysis of CNR and SNR was the same for both Roadmap and DSA. The use of Bismuth shielding is an alternative that can reduce the radiation impairment due to temporary hair loss and other stochastic effects that may occur after cerebrovascular intervention.

• Clean Technology
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• v.30 no.1
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• pp.23-27
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• 2024

Bismuth is a promising anodic for Li-ion batteries (LIBs) due to its adequate operating voltage and high-volume capacity (3,765 mAh cm^-3). Nevertheless, inevitable volume expansion during Bi alloy reactions leads to severe capacity loss and cell destruction. To address this, a complex of bismuth alloy nanoparticles (Bi@NC) embedded in an N doping-carbon coating is fabricated via a simple pyrolysis method. Nano-sized bismuth alloys can improve the reaction dynamics through a shortened Li⁺-ion diffusion path. In addition, the N-doped carbon coating effectively buffers the volume change of bismuth during the extended alloy/dealloy reaction with Li⁺ ions and maintains an effective conductive network. Based on the Thermogravimetric analysis (TGA) showed high bismuth alloy loading (80.9 wt%) and maintained a high gravimetric capacity of 315 mAh g^-1 up to 100 cycles with high volumetric capacity of 845.6 mAh cm^-3.

• YAKHAK HOEJI
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• v.36 no.6
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• pp.570-576
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• 1992

The treatment with gentamicin in the presence of pretreatment with bismuth nitrate significantly reduced blood urea nitrogen compared with given gentamicin alone. But the amelioration of gentamicin-induced nephrotoxicity by bismuth nitrate was abolished by pretreatment with indomethacin that is cyclooxygenase inhibitor, which significantly decreased renal glutathione S-transferase activity and thiobarbituric acid reactive substance compared with mice of given gentamicin and bismuth nitrate. On the other hand, treatment with bismuth nitrate significantly increased prostaglandin $E_2$ production in rat kidney slice. These results suggest that bismuth nitrate might ameliorate the nephrotoxicity of gentamicin via prostaglandin $E_2$ production.

• Journal of Surface Science and Engineering
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• v.38 no.1
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• pp.7-13
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• 2005

Bismuth thin films were prepared on glass substrate with RF magnetron sputtering and effects of substrate temperature on surface morphology and their electrical transport properties were investigated. Grain growth of bismuth after nucleation and the onset of coalescense of grains at 393 K were observed with field emission secondary electron microscopy. Continuous thin films could not be obtained above 473 K because of grain segregation and island formation. Hall effect measurements showed that substrate heating yields the decrease of carrier density and the increase of mobility. Resistivity of bismuth film has its minimum (about 0.7 x 10/sup -3/ Ωcm) in range of 403～433 K. Annealing of bismuth films deposited at room temperature was carried out in a radiation furnace with flowing hydrogen gas. The change of resistivity was not significant due to cancellation of the decrease of carrier density and the increase of mobility. The abrupt change of electrical properties of film annealed above 523 K was found to be caused by partial oxidation of bismuth layer in x-ray diffraction analysis.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3401-3408
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• 2023

In this study, we used the Monte Carlo N-Particle program to simulate the gamma-ray spectra obtained from plastic scintillators holes filled with bismuth nanoparticles. We confirmed that the incorporation of bismuth nanoparticles into a plastic scintillator enhances its performance for gamma-ray spectroscopy using the subtraction method. The subtracted energy spectra obtained from the bismuth-nanoparticle-incorporated and the original plastic scintillator exhibit a distinct energy peak that does not appear in the corresponding original spectra. We varied the diameter and depth of the bismuth-filled holes to determine the optimal hole design for gamma-ray spectroscopy using the subtraction method. We evaluated the energy resolutions of the energy peaks in the gamma-ray spectra to estimate the effects of the bismuth nanoparticles and determine their optimum volume in the plastic scintillator. In addition, we calculated the peak-to-total ratio of the energy spectrum to evaluate the energy measuring limit of the bismuth nanoparticle-containing plastic scintillator using the subtraction method.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.114-120
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• 2006

Bismuth vanadate is one of the environmentally benign substitutes for conventional inorganic pigments composed of heavy metals. The effect of process parameters on the physical properties of bismuth vanadate pigment prepared from aqueous solutions of potassium vanadate and bismuth nitrate were experimentally examined. Two aqueous solutions were fed into precipitation chamber at the same flow rate, and precipitates were formed at primary pH of 4.5 and secondary pH of 7.0~7.5. After aging for 3 hours in reaction mixture, 3 hours' calcination at $400^{\circ}C$ gave bismuth vanadate pigment with a good color and hiding power. Increase in molybdenum concentration in reaction mixture increased the hiding power of the pigment, but the other minor constituents had minor effect on the physical properties of the pigment.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.65-71
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• 2019

With regard to current Neck CT, Bismuth shielding boards are often being used to reduce exposure to superficial organs such as the thyroid. However, beam hardening often occurs near superficial organs with Bismuth shielding boards and variations in CT Number, Noise, and Uniformity values occur severely. This study looked into the usefulness of shielding boards made from aluminum and silicone that can be easily obtained and have good machinability by comparing them to the existing Bismuth shielding board. An Aluminum 7.3mm and a Silicone 21.5mm were made with shielding ratios similar to that of the Bismuth(0.06 mmPb). TLD (TLD-100) was placed on the thyroid area of the Phantom (RS-108T) and 5 doses were measured for each. To compare image quality, CT Number and Noise variations in axial images of the thyroid area in Neck CT images were compared. Also, variations in CT Number, Noise, and Uniformity were measured in the AAPM phantom images and compared. In the results, when thyroid doses for each shielding board were compared, the Bismuth shielding board showed a 14% reduction, the Silicone 21.5mm showed a 15% reduction, and the Aluminum 7.3mm showed a 13% reduction compared to the Non-Shield. Statistically, there were no significant differences in comparison with the Bismuth shielding board. In CT Number variations of thyroid area images, variations were largest for the Bismuth shielding board. With Uniformity evaluations of the AAPM phantom, the Bismuth shielding board was found unsuitable and the Aluminum 7.3mm and Silicone 21.5mm satisfied the acceptance criteria. Research results show that the Aluminum 7.3mm and Silicone 21.5mm have a similar shielding ratio to the high-priced Bismuth shielding board that is currently being used clinically and in comparison tests of CT Number attenuation coefficient variations, Noise, and Uniformity which are phantom image evaluation items, they proved to be better than Bismuth shielding boards. If various shielding boards are made using aluminum and silicone, sized appropriately for superficial organs, it would be useful in decreasing patient doses.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.171-175
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• 2008

The aim of this study is to assess the dose reduction of eye lens and availability of bismuth garments resulting from the use of radioprotective bismuth garments to shield the eyes of patients undergoing head CT. Rando phantom and TLDs were used to determine the amount of dose reduction by bismuth shielding of the eye in the following simulated CT scans : (a) scanning of the head including orbits, (b) scanning of the whole head, and (c) $20^{\circ}$ angled scanning of the head excluding orbits. The average dose reduction of eye lens was 43.2%, 36.0% and 1.4% for the three CT scans listed above. Significant reduction in the eye lens dose was achieved by using superficial orbital bismuth shielding during head CT scans. However, bismuth shields should not be used for the patients when their eyes are excluded from the primarily exposed region.