• Journal of the Korean Magnetics Society
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• v.19 no.6
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• pp.203-208
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• 2009

Magnetic and Ka-band absorbing properties have been investigated in Ti-Co substituted M-type barium hexaferrites with $BaTi_{0.5}Co_{0.5}Fe_{11}O_{19}$ composition. The ferrite powders were prepared by conventional ceramic processing technique and used as absorbent fillers in ferrite-rubber composites. The magnetic properties were measured by vibrating sample magnetometer. The complex permeability and dielectric constant were measured by using the WR-28 rectangular waveguide and network analyzer in the frequency range 26.5~40 GHz. For the Ti-Co substituted M-hexaferrites, the ferromagnetic resonance is observed at Ka-band (29.4 GHz). The matching frequency and matching thickness are determined by using the solution map of impedance matching. A wide band microwave absorbance is predicted with controlled ferrite volume fraction and absorber thickness.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.113-120
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• 2017

The purpose of this present study was to evaluate the surface radiation dose reduction and radiograph artifact images in computed tomography (CT) for the manufactured radiation shields by using sea-shells. The radiation convergence shields were made from silicons, sea-shells, barium powders, producted circle types of diameter 50 mm, thickness 3.5 mm for 5 kinds (only silicon shield, only barium shield, mixed sea-shells with silicon shield, mixed barium with silicon shield, mixed sea-shells with barium and silicon shield). Radiation generation and acquisition were used 4-channel multi-detector CT. The results of this study showed that mixed sea-shells with silicon shields could reduce the surface dose of 5.3% without radiograph artifact images. In the future, we will expect the radiation convergence shield as environmentally friendly materials by using the recycling of sea-shells with the advantages of silicon which can make various shapes.

• Membrane Journal
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• v.29 no.6
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• pp.355-361
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• 2019

We studied the removal of barium ions that may be contained in industrial wastewater using the existing capacitive deionization (CDI). The 30 mg/L BaCl₂ (barium chloride dihydrate) solution was used as the feed solution, and the flow rate was set to 10 mL/min. The adsorption conditions were varied from 1.2 V to 3, 5 and 7 min, and the desorption conditions were -1, -1.5, -2 V and 1, 2 and 3 min, respectively, to select the most efficient conditions. As a result, barium ion removal efficiency of 64.4% was obtained under the adsorption conditions of adsorption of 1.2 V/7 min and the desorption -1 V/1 min. For the desorption voltages and time, under the same experimental conditions, the removal efficiency of CDI for 30 mg/L NaCl aqueous solution with the same concentration as barium showed 69.9% removal efficiency under the adsorption conditions of and the desorption conditions of 1.2 V/7 min desorption -1 V/1 min, respectively.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.403-408
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• 2013

This study made a tentative estimation of the shielding rate of barium compound by thickness through monte carlo simulation to apply medical radiation shielding products that can replace existing lead. Barium sulfate($BaSO_4$) was used for the shielding material, and thickness of the shielding material specimen was simulated from 0.1 mm to 5 mm by applying $15{\times}15cm^2$ of specimen area, $4.5g/cm^3$ of density of barium sulfate, and $11.34g/cm^3$ density of lead. Entered source was simulated with 10kVp Step in consecutive X-ray energy spectrum(40 kVp ~ 120 kVp). Absorption probability in 40 kVp ~ 60 kVp showed same shielding rate with lead in 3 mm ~ 5 mm of thickness, but it was identified that under 2 mm, the shielding rate was a bit lower than the existing lead shielding material. Also, the shielding rate in 70 kVp ~ 120 kVp energy band showed similar performance as the existing lead shielding material, but it was tentatively estimated as fairly low shielding rate below 0.5 mm. This study estimated the shielding rate of barium compound as the thickness function of x-ray energy band for medical radiation through monte carlo simulation, and made comparative analysis with existing lead. Also, this study intended to verify application validity of the x-ray shielding material for medical radiation of pure barium sulfate. As a result, it was estimated that the shielding effect was 95% higher than the existing lead 1.5 mm in at least 2 mm thickness of barium compound in medical radiation energy band 70 kVp ~ 120 kVp, and this result is considered valid to be provided as a base data in weight lightening production of radiation shielding product for medical radiation.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.152-160
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• 1979

The promoting effect of Ba or Sr addition was investigated for furfural hydrogenation reaction over copper-chromium oxide catalysts. X-ray diffraction patterns showed the appearance of $BaCrO_4$ and $SrCrO_4$ phases in Ba, and Sr promoted copper-chromium oxide catalysts. For both Ba and Sr promoted catalysts, the activity decline with reaction time was much smaller compared to that of unpromoted catalyst and copper-chromium oxide catalyst dispersed on silica, reproducible EPR signals of Cr(V) were observed when CO was adsorbed. The promoting effect of Ba addition can be interpreted in terms of active sites dispersion and stabilization.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.256-261
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• 1999

Ileus caused by impaction of hardened residual barium stagnated in the colon, a rare complication of barium-enema examination, constitutes a particularly serious problem when it occurs in congenital megacolon patients. The administration of gastrografin in such case has proven efficacy in dissolution of impacted barium refratory to routine means of evacuation. We experienced a case of barium-impaction occurred in 6-months old male who had congenital megacolon. Gastrografin enema was a safe and simple method used in the management of this case.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.33-39
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• 2015

$BaTiO_3$ is typical ferromagnetic materials with dielectric constant of above 200. $BaTiO_3$ nanoparticles applications are available for multiple purposes such as nanocapacitors, ferroelectric random access memories, and so on. Applications are is diverse from the dispersion of nanoparticles depending on the route of synthesis. In this study, $BaTiO_3$ nanoparticles were synthesized by two different methods such as oxalate method and sol-gel process (ambient condition sol method). Particle size and dispersion condition were studied according to the preparation method and capping agent. Poly vinyl pyrrolidone (PVP) was used as a capping agent in oxalate method and tetrabutylammonium hydroxide (TBAH) used as a capping agent in sol-gel process each. Cubic crystal structure of $BaTiO_3$ phase could be confirmed by X-ray diffraction analysis. Fourier transform-infrared spectroscopy was employed for the confirmation of the capping agent and $BaTiO_3$ nanoparticles. The particle size and distribution analysis was also performed by particles size analyzer and scanning electron microscope.

• Journal of the Korean Magnetics Society
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• v.19 no.6
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• pp.209-215
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• 2009

M-type barium ferrite (BaFe12O19) powders were synthesized through the co-precipitation method. Starting material composition $Fe^{3+}:\;Ba^{2+}$ mole ratio was fixed as 8 and the relative amount of $Fe^{3+}$ and $Ba^{2+}$ was controlled. Structure and magnetic properties and powder morphology were investigated using XRD, SEM, VSM. Powder showing high coercivity and small magnetization was obtained at pH8 and $Fe_{3+}:\;Ba_{2+}$ of 12 : 1.5. Small magnetization value was originated from the existence of ${\alpha}-Fe_2O_3$. Single-phase Mtype barium ferrite were obtained regardless of the heat treatment condition and the amount of $Fe_{3+}\;and\;Ba_{2+}$ at pH$\approx$10. The largest value of magnetization (55.7 emu/g) under investigation were obtained when $Fe_{3+}:\;Ba_{2+}$ of 13.6 : 1.7 and furnace cooled powder in $O_2$. Particle size of powder was in the range of 50~200 nm.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.911-922
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• 2023

Purpose To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation. Materials and Methods Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media. Results For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media. Conclusion The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.05a
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• pp.65-66
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• 1991