• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.497-506
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• 2023

In the case of radiation workers in medical institutions, radiation exposure is made for patient protection and accurate procedures, so they have a problem of low dose exposure. Low-dose radiation exposure occurs mainly in parts of the body other than the Apron area, and the most frequent place is the skin of the back of the hand. In particular, since the medical personnel's hands require senses and fine movements during the procedure, they are defenseless in the radiation exposure area and are at risk of exposure. It can solve the problem of shielding such as lead gloves, and it is difficult to use by suggesting the activity of the hand during the procedure. To solve this problem, a shielding cream capable of obtaining a functional radiation protection effect was developed and its shielding performance was compared with lead equivalent of 0.1 mmPb. In the process of manufacturing shielding cream, the shielding performance was improved by adding a defoaming process to reduce air holes to increase the density of the cream. Therefore, the shielding cream using barium sulfate as the main material has a lower shielding rate than the lead plate, and in the realm of effective energy, it is 59%, At high effective energy, a difference of about 37% was shown, indicating that there is a functional radiation protection effect. The advantage is that it can be used directly on the skin, and it is considered that it can be used before wearing surgical gloves and has a permanent protective effect.

• Analytical Science and Technology
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• v.22 no.2
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• pp.186-190
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• 2009

The oxidation studies of a sulfur to a sulfate ion by various oxyhalide oxidants in organic (thiourea, methionine) and inorganic (sulfate, thiophosphate) compounds were carried out in an acidic solution. The optimized result of the oxidation reaction was obtained when a bromate compound (${BrO_3}^-$) as an oxidant and a 3 M $HNO_3$ solvent were used. The chemical yield for the oxidation of the organic and inorganic sulfur compounds to a sulfate ion was monitored as 80% for thiophosphate, 87% for methionine, and 100% for thiourea and sulfate within 5% RSD. The oxidations of thiourea required at least 1.6 equivalents of the bromate in an acidic solution. In the case of the oxidation of methionine and thiophosphate, the oxidation yields were above 80% if the bromate was used at 20 times higher than that of the substrates. The sulfate ion was quantitatively measured by using a GPC counting of $^{35}S$ followed by precipitates of $BaSO_4$. A quenching correction curve for the $^{35}S$ counting was obtained to use the difference via the precipitate weight result.

• Elastomers and Composites
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• v.36 no.1
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• pp.3-13
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• 2001

To resolve environmental problem of waste tire and asbestos and also to capitalize the wastes, we developed a new kind of friction material using scrap tire, potassium hexatitanate, filler, and friction modifier in which rubber made a continuous phase. The material containing 5, 20, 10, 20phr of potassium hexatitanate, phenol, friction modifier, $BaSO_4$, respectively showed good friction properties, high and stable coefficient or friction, and low wear rate.

• Journal of radiological science and technology
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• v.24 no.2
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• pp.53-57
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• 2001

The purpose of this study is to investigate the contamination rate of barium sulfate suspension made in the exposed state in usual circumstances. This study was performed in four university hospital using the contrast media by barium sulfate powder. The specimen were detected at dispensing water, agitator and mixing tank. We also classified the suspension into general bacteria, mycete, and Bacillus coli infection. The tap water were used to dispense water in the all hospitals. Bacillus colt were not detected in the all. General bacteria and mycete were not detected in the one specimen, but detected in two specimen over defined value. In the contamination rate of agitator, mixing tank, and the manufactured, Bacillus coli were not detected in all. However, general bacteria and mycete were detected too numberous to count. In conclusion, the refined water must be used in dispensing water in manufacturing suspension. The disinfectant is also used in washing the agitator and mixing tank for sterilization. Hand washing is indispensible to manufacturing suspension for preventing from infection.

• Journal of radiological science and technology
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• v.20 no.2
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• pp.68-72
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• 1997

Small bowel series using methylcellulose are considered a better technique than using other contrast media considering a significant decrease of transit time of $BaSO_4$ and that of the necessary time for the examination. We investigated the mean transit time of $BaSO_4$, maximum luminal diamenter of small bowel, optical density and flocculation frequency after adminstratting 100 ml of 120% $BaSO_4$ to 20 pts), 150 ml of 70% $BaSO_4$ to 20 pts and 200 ml of $BaSO_4$ with 600 ml of mechylcellulose. It was shown that the technique using 150 ml of 70% $BaSO_4$ had the best result. When we apply a adequate amount of density(w/v%), dosage to pts for small bowel series using MC, we can decrease an examination time and have the better image due to double contrast. It is considered that a more study to lower the density of 70% $BaSO_4$ is necessary.

• Journal of radiological science and technology
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• v.3 no.1
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• pp.43-48
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• 1980

An experimental study was carried out to make a comparison between tube voltage and density of barium sulphate in the stomach radiography. The results were summarized as follows: 1. The percentage of density on concentrations of barium sulphate as contrast media could not show in differences with changes of voltages applied X-ray tube. 2. The changes of density visualized on X-ray film mainly depend upon with thickness of stomach filled barium sulphate than the ratio of barium sulphite and plain water volume. 3. The lesions positioned in upper part within stomach exhibited their best discrimination performanance with depth in the low tube voltage, followed in order by the middle part and lower part. However, the discrimination performanance at the high tension radiography uniformly visualized over X-ray film without density in change.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.39-44
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• 2003

The aim of this study is to evaluate a efficient w/v% barium suspension and w/v% sodium carboxy methyl cellulose (SCMC) for small bowel examination. Between november 2001 and june 2002, 370 patients were examined small bowel examination with oral administration of barium suspension mixed with SCMC. we classified into six groups including A(fine type 40% $BaSO_4$ mixed 0.5% SCMC and 600 ml 0.5% SCMC administration), B(fine type 30% $BaSO_4$ mixed 0.5% SCMC), C(fine type 20% $BaSO_4$ mixed 0.5% SCMC), D(fine type 25% $BaSO_4$ mixed 0.5% SCMC), E(D mixed coarse type 25% $BaSO_4$ mixed 0.5% SCMC), F(D mixed coarse type 25% $BaSO_4$ mixed 0.75% SCMC). We measured transparency rate of contrast media transit time, administration dose, viscosity and particle size. The transparency rate was higher then 80 kV and 90 kV in 100 kV in the same 20 mAs condition. Transit time was the fastest in A group(mean trans time 56 minutes) and the slowest in E group(mean 100 minutes), Administration dose was the smallest in A group(mean dose 541 ml and the most in E group(mean 1,100 ml), viscosity was the lowest in E(125.1 mpa/s) and the highest in A(375.5 mpa/s), and particle size was $1.0\;{\mu}m$ in A, B, C, and D group, $0.6\;{\mu}m,\;1.0\;{\mu}m,\;10.0\;{\mu}m$ in E, F group. In conclusion, we propose that the efficient condition for small examination is high voltage technique, high density $BaSO_4$, and 0.625% w/v SCMC.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.282-288
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• 2015

A monte carlo simulation about shielding material and thickness of the syringe shield for radiation shield was performed. As a result of analysis, high atomic number materials such as tungsten, lead and bismuth have the highest shielding effect. However, $^{18}F$, $^{67}Ga$ and $^{111}In$ show high energy distribution in the region with thin shielding thickness. As the thickness of shielding materials increased, the energy distribution decreased due to reduction of ${\gamma}$-ray. In the case of low atomic number materials, they, showed energy distribution from highest to lowest, were barium sulfate, steel, stainless, iron and copper. Aluminum, plastic, concrete and water showed diverse aspect. they showed relatively high energy distribution because of increased ${\gamma}$-ray that penetrate the shield.

• YAKHAK HOEJI
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• v.36 no.6
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• pp.538-547
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• 1992

Optimal synthetic condition of barium sulfate were investigated from the viewpoint of yield and bulkiness according to a randomized complete block design proposed by G.E.P. Box and K.B. Wilson. Barium chloride and magnesium sulfate were utilized as reactants in order to prepare barium sulfate in this study. It was found that optimum temperature range of reactant solutions was $60{\sim}100^{\circ}C$ and the optimum concentration range of the reactant solutions was $10{\sim}17.3%$ and $10{\sim}20%$ respectively, on the viewpoint of yield and bulkiness. The optimum mole ratio of $BaCI_2$ to $BaSO_4$ was in the range of $1.50{\sim}2.0$ and the optimum mole ratio of $BaCI_2$ to $BaSO_4$ was in the range of $1.50{\sim}2.0$ and the optimum reacting time range was $15{\sim}20$ minutes. The optimum drying temperature range was $110{\sim}130^{\circ}C$ from the viewpoint of yield, but it was $90{\sim}110^{\circ}C$ on the basis of bulkiness. Apparent viscosity of barium sulfate suspensions dispersed in various concentrations of Na. CMC was measured by using Brookfield synchrolectric viscometer model LVT, the relative equation, log ${\eta}_{sp}=A+B.{\phi}$ was examined and the equation was found to agree fairly well. 1 w/v% Na. CMC aqueous solution and 0.1 volume fraction of $BaSO_4$ powder were optimum in the preparation of $BaSO_4$ suspension showing highest viscosity at infinite shearing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1871-1876
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• 2013

In this study, we developed and characterized the shielding properties of dose reduction fiber (DRF, Buffalo Co.) sheet during brain and chest CT examinations. The DRF sheet was composed of $1{\sim}500{\mu}m$ oxide Bismuth ($Bi_2O_3$) and 5 ~ 50 nm nano-barium sulfate ($BaSO_4$). Phantom and clinical studies were performed for characterization of the DRF shielding properties. In clinical study, we measured doses of eye, chest, abdomen and reproductive system of 60 patients in 3 hospitals during brain and chest CT examinations. We could determined the shielding effect of the DRF by comparing the doses when we used the DRF sheet or not. When we used the sheet during CT examination, the scattered dose were reduced about 20~50%. So, we suggest that the fiber should be used in radiological examinations for reducing patients doses.