• Polymer(Korea)
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• v.37 no.5
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• pp.563-570
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• 2013

Poly(vinyl pivalate) (PVPi) was bulk polymerized to make poly(vinyl alcohol) (PVA) microfibrils to apply for polymeric embolization coils replacing metalic coils. Then, syndiotactic PVA (s-PVA) microfibrils having number-average degree of polymerization of 1100 and s-diad content of 60.4% were prepared via saponification of the PVPi with no separate spinning process. To make s-PVA microfibrils with radiopacity, zirconium dioxide ($ZrO_2$) and barium sulfate ($BaSO_4$) were added into s-PVA microfibrils during saponification. The computed tomography (CT) value indicating radiopacity reached up to over 1000 when the amount of $ZrO_2$ and $BaSO_4$ were 12 and 6 wt%, respectively.

• Advances in concrete construction
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• v.4 no.2
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• pp.123-143
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• 2016

Use of heavy fuel fly ash (HFFA) (diesel and cracked fuel) for power generation in Saudi Arabia has generated and accumulated large quantities of HFFA as a byproduct. In this research, HFFA is studied with the emphasis on the utilization of this waste material in concrete blocks and asphalt concrete mixes. Two types of mixes, one with low and other with high cement content, were studied for concrete blocks. Different mixes having varying percentages of HFFA (0% to 25%), as cement/sand replacement or as an additive, were studied. The performance of concrete blocks is evaluated in terms of compressive strength, water absorption, durability and environmental concerns. The results showed that blocks cannot be cast if more than 15% HFFA is used; also there is a marginal reduction in the strength of all the mixes before and after being exposed to the sulfate solution for a period of ten months. HFFA is studied in asphalt concrete mixes in two ways, as an asphalt modifier (3&5%) and as a filler (50%) replacement, the results showed an improvement in stiffness and fatigue life of mixes. However, the stability and indirect tensile strength loss were found to be high as compared to the control mix due to moisture damage, indicating a need of using antistripping agents. On environmental concerns, it was found that most of the concerned elements are within acceptable limits also it is observed that lower concentration of barium is leached out with the higher HFFA concentrations, which indicates that HFFA may work as an adsorbent for this leaching element.

• Polymer(Korea)
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• v.34 no.4
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• pp.346-351
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• 2010

The mechanical properties of polypropylene (PP) composites, especially the effects of the filler shapes on the modulus were studied. The experimental results were investigated and compared with the theoretical approaches proposed by Lee and Paul and based on Eshelby's principle, which three dimensional ellipsoids were filled as filler and analyzed in terms of aspect ratio, ${\rho}_\alpha=a_1/a_3$ and ${\rho}_\beta=a_1/a_2$. The shapes of fillers were observed by SEM and aspect ratios were statistically calculated. Young's moduli in the longitudinal and transverse directions for barium sulfate whose shape was sphere ($\rho_\alpha=\rho_\beta=1$) had the same values, as predicted values. The modulus in the $x_1$ direction for a glass fibers increased as the filler content increased, while the modulus in the $x_3$ direction was increased relatively small. Furthermore, mica was also used to investigate the effects of the primary and secondary aspect ratios on the mechanical properties.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4137-4141
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• 2021

As NPPs continue to operate, liquid waste continues to be generated, and containers are needed to store and transport them at low cost and high capacity. To transport and store liquid phase very low-level radioactive waste (VLLW), a container is designed by considering related regulations. The design was constructed based on the existing container design, which easily transports and stores liquid waste. The radiation shielding calculation was performed according to the composition change of barium sulfate (BaSO₄) using the Monte Carlo N-Particle (MCNP) code. High-density polyethylene (HDPE) without mixing the additional BaSO₄, represented the maximum dose of 1.03 mSv/hr (<2 mSv/hr) and 0.048 mSv/hr (<0.1 mSv/hr) at the surface of the inner container and at 2 m away from the surface, respectively, for a 10 Bq/g of ⁶⁰Co source. It was confirmed that the dose from the inner container with the VLLW content satisfied the domestic dose standard both on the surface of the container and 2 m from the surface. Although it satisfies the dose standard without adding BaSO₄, a shielding material, the inner container was designed with BaSO₄ added to increase radiation safety.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.215-221
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• 2023

Among brain CT scan conditions including the lens, the tube voltage was changed to 80, 100, and 120 kVp and applied. The change in dose was analyzed using lead, lead goggles and barium sulfate silicon shielding materials, and the degree of influence of the shielding materials on image quality was compared and analyzed by applying the SNR, CNR, and SSIM index analysis methods. As a result, it was analyzed that although the dose was reduced by applying all shielding materials, the difference in dose reduction was not large (P > 0.05). In addition, as for the change in image quality due to the application of the shielding material, SNR and CNR were the highest when lead goggles were applied, and the structural similarity was measured to be the best as it was closest to the reference value of 1 in SSIM analysis. Therefore, based on the results of this study, it is thought that if more diverse shielding materials and clinical test results are derived and applied, it will be helpful for the clinical application criteria in the case of shielding utilization inspection.

• Conservation Science in Museum
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• v.30
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• pp.23-46
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• 2023

The Jija Chongtong Gun, owned by Seokdang Museum of Dong-A University, is a tubedstyle heavy weapon of the battlefield in the mid-Joseon Dynasty and is the second largest firearm after Cheonja Chongtong. The original surface color of the Jija Chongtong Gun was obscured by foreign substances and therefore it was judged that its condition requires the conservation treatment. For stable conservation treatment, gamma ray and X-ray non-destructive transmission surveys was conducted to determine the internal structure and conservation condition. And the component analysis on the material components and surface contaminants of Jija Chongtong Gun was conducted by utilizing the p-XRF component analysis, SEM-EDS component analysis, and XRD analysis. As a result of the gamma-ray and X-ray non-destructive transmission investigation, a large amount of air bubbles was observed inside Jija Chongtong Gun, and the part that appeared to be a chaplet by visual observation was not identified. As a result of gamma-ray and p-XRF component analysis, it was confirmed that Jija Chongtong Gun was bronze made of copper (Cu), tin (Sn), and lead (Pb) alloy. As a result of surface analysis of foreign substances using SEM-EDS, it was confirmed that the main components of white foreign substances were calcium (Ca), sulfur (S), and titanium (Ti). Titanium was presumed to be titanium dioxide (TiO₂), the main component of white correction fluid. The red foreign substance was confirmed to contain barium (Ba) as its main ingredient, and was presumed to be barium sulfate (BaSO₄), an extender pigment in paint. White and red contaminants, mainly composed of titanium and barium, are presumed to have been deposited on the surface in recent years. The yellow foreign substances were confirmed to be aluminum (Al) and silicon (Si), and were presumed to have originated from soil components. As a result of SEM-EDS and XRD component analysis, the white foreign substance was confirmed to be gypsum (CaS). Based on the results of component analysis, surface impurities were removed, stabilization treatment, and strengthening treatment were performed. During the conservation process, unknown inscriptions Woo (右), Byeong (兵), Sang (上), and Yi (二) were discovered through a portable microscope and precise 3D scanning. In addition, the carving method, depth, and width of the inscription were measured. Woo Byeong Sang is located above Happo Fortress in Changwon, and Yi can be identified as the second hill.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.1-9
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• 1989

The distribution of portal veins within the liver in 30 Korean native cattle were observed. Vinylite solution was injected into portal veins of eighteen specimens for cast preparation. The angiography was prepared in twelve specimens by injecting 30% barium sulfate solution into portal veins, and then radiographed on a X-ray apparatus(Shimadzu 800MA 120Kvp). The results were summarized as follow: 1. The Vena portae was divided immediately upon entering the liver into a very short Truncus dexter venae portae($14.75{\pm}4.86$ : 6.9~23.1mm) and a long Truncus sinister venae portae($94.16{\pm}9.62$ : 110~150mm). 2. The Truncus sinister venae portae runs of first in the long axis of the liver from the Porta hepatis toward the left lobe. At the boundary between the quadrate and left lobes it bends sharply 50 to 80 degrees toward the Incisura ligamentum teretis, and after a course of 36. 5 to 54.mm between the quadrate and left lobes, ends abruptly. The Truncus sinister venae portae is divided for description into the Pars transversa, from the Porta hepatis to the flexure, and the Pars umbilicalis, from the flexure to the end. 3. The branches of Venae portae were Ramus ventralis lobi sinistri, Ramus intermedius lobi sinistri, Ramus dorsalis lobi sinistri, Ramus lobi quadratii, Ramus ventralis lobi dextri, Ramus intermedius lobi dextri, Ramus dorsalis lobi dextri, Rami processus caudatorum and Rami processus papillarum. 4. The Ramus intermedius lobi sinistri was arised from the left surface of the Pars umbilicalis, and was origined on the common trunk with Ramus dorsalis lobi sinistri(3 cases, 10%) or Ramus ventralis lobi sinistri(3 cases, 10%). 5. The Rami lobi quadratii consisted of the vein(15 cases, 50%) or two veins(15 cases, 50%), and was observed on the arched-shaped at 2 cases (6.6%) of the liver. 6. The Rami processus caudatorum consisted of one vein(28 cases, 93.3%) or two veins(2 cases, 6.6%). The former were formed common trunk with R, dorsalis lobi dextri(7 cases, 23.3%) or R. ventralis lobi dextri (2 cases, 6.6%). 7. The Rami processus papillarum were arised from the dorsal border of Pars transversa, and also gave off many small branches supplied papillary process of the caudate lobe. 8. The anastomosis on the branches of Vena portae was observed in the intralobar and interlobar areas. 9. The Truncus dexter venae portae and Truncus sinister venae were ramified many secondary branches that were radiated within the liver. 10. On the diaphragmatic surface, small vessels of the portal veins were observed, while there were big ones on the visceral surface. 11. The ramified angles at Ramus dorsalis lobi dextri, Rami processus papillarum, Ramus dorsalis lobi sinistri, Ramus intermedius lobi sinistri, Ramus ventralis lobi sinistri, Rami lobi quadratii, Rami processus caudatorum, Ramus ventralis lobi dextri and Ramus intermedius were 10~50, 70~110, 100~150, 140~170, 185~220, 270~330, 240~300, 270~320 and 340~10 degrees, respectively.

• Journal of Environmental Impact Assessment
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• v.22 no.2
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• pp.135-145
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• 2013

The recycling of coal bottom ash generated from coal power plants in Korea has been limited due to heterogenous characteristics of the materials. The most common management option for the ash is disposal in landfills (i.e. ash pond) near ocean. The presence of large coarse and fine materials in the ash has prompted the desire to beneficially use it in an application such as fill materials. Prior to reuse application as fill materials, the potential risks to the environment must be assessed with regard to the impacts. In this study, a total of nine test cells with bottom ash samples collected from pretreated bottom ash piles and coal ash pond in a coal-fired power plant were constructed and operated under the field conditions to evaluate the leachability over a period of 210 days. Leachate samples from the test cells were analyzed for a number of chemical parameters (e.g., pH, salinity, electrical conductance, anions, and metals). The concentrations of chemicals detected in the leachate were compared to appropriate standards (drinking water standard) with dilution attenuation factor, if possible, to assess potential leaching risks to the surrounding area. Based on the leachate analysis, most of the samples showed slightly high pH values for the coal ash contained test cells, and contained several ions such as sodium, potassium, calcium, magnesium, chloride, sulfate, and nitrate in relatively large quantities. Three elements (aluminum, boron, and barium) were commonly detected above their respective detection limits in a number of leachate samples, especially in the early leaching period of time. The results of the test cell study indicate that the pollutants in the leachate from the coal ash test cells were not of a major concern in terms of leaching risk to surface water and groundwater under field conditions as fill materials. However, care must be taken in extending these results to actual applications because the results presented in this study are based on the limited field test settings and time frame. Structural characteristics and analysis for coal bottom ash may be warranted to apply the materials to actual field conditions.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.117-123
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• 1992

In this study, the water soluble sulfur, lead and cadmium contents of Prunus yedoerais leaves were analysed. The water soluble sulfur content considered as a main pollution indicator was extracted by the conventional barium sulfate method and the concentrations were calculated. The results obtained are as follows ; 1. The water soluble sulfur contents of the leaves collected from the heavy traffic roadside trees were two time higher than that of control materials on average. It was presumed those trees has been under meaningful pollutants impact. The water soluble sulfur contents of leaves between Cheonju and Iri was higher than that between Iri and Kunsan. 2. The range of Pb contents from roadside trees was 11.9-34.5 ppm for exceeding the control. The trees grown on the right roadside were more heavliy Pb-contaminated. 3. The range of Cd contents from roadside trees grown between Iri and Kunsan, the site-to-site variations of Cd concentration was not significant.

• Analytical Science and Technology
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• v.29 no.2
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• pp.65-72
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• 2016

This study presented an analytical method for detecting radium in soils using a liquid scintillation counter (LSC). The isotope ²²⁶Ra was extracted from soil using the fusion method and then separated from interfering radionuclides using the precipitation method. Radium was coprecipitated as sulfate salts with barium (Ba) and then converted into Ba(Ra)CO₃, which is soluble in an acidic solution. The isotope ²²²Rn, the decay progeny of ²²⁶Ra, was trapped in a water immiscible cocktail and analyzed by LSC. The pulse shape analysis (PSA) level was estimated using ⁹⁰Sr and ²²⁶Ra standard solutions. The figure of merit was the highest at PSA 80, while the alpha spillover was the lowest at PSA 80. The counting efficiency was 243 ± 2% in a glass vial. This analytical method was verified with International Atomic Energy Agency (IAEA) reference materials, including IAEA-312, IAEA-314, and IAEA-315. The recovery ranged from 60–82%, while the relative bias between the measured value and the recommended value was less than 10%. The minimum detectable activity was 2.1 Bq kg⁻¹ with dry mass 1 g, the background count rate of 0.02 cpm, the recovery rate of 70% and counting time of 30 min.