• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.123-130
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• 2015

For the analysis of ⁹⁰Sr, which is a pure beta emitter, radiochemical separation from the main interfering elements such as Ca, Ba and Ra is required due to their similarity in chemical behavior to strontium. This study describes a radioanalytical procedure using extraction chromatography for separating Sr from interfering elements. The maximum capacity of the resin for Sr was approximately 6 mg per 1.5 mL of bed volume (BV). The recovery of Sr on the resin 1.5 mL (BV) was quantitative for the calcium level of 200 mg at the flow rate of 1 mL min^-1. However the chemical yield declined by increasing the flow rate by up to 5 mL min^-1 even at the calcium level of 200 mg. When using the same BV of Sr resin, the performance of the resin was enhanced as the cross-sectional area of the Sr resin column is small.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.3
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• pp.453-467
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• 1998

This study helps to clarify conflicting reports by comparing the physical properties and accuracy of complete denture processed by the pack and press technique, continuous- pressure injection technique(SR-Ivocap system) and Mark press technique. The 6 different specimens have been evaluated using the SEM, Impact test, DSC (Differential Scanning Calorimetry) and DMTA (Dynamic Mechanical Thermal Analysis). Each sample was made of SR-Ivocap resin and QC-20 resin by different processing methods. The results were as follows ; 1. As the result of the observation on the fracture surface of resin by use of SEM, sample SR-Ivocap resin cured by continuous pressure injection method showed the most homogeneous structure. This is why molecules in SR-Ivocap resin have no orientation. 2. As the result of the Impact test in order to measure the deformity, fracture energy and impact resistance of resin, the samples with QC-20 acrylic resin and SR-Ivocap resin cured by continuous pressure injection method were exellent. 3. In consequence of measuring ${\alpha}$-glass transition temperature by use of DSC on the basis of temperature change, the glass transition temperatures of sample QC-20 resin cured by pack and press method and sample SR-Ivocap resin cured by continuous pressure injection method were very similar. Thus volumetric stability could not be evaluated only by glass transition temperature. 4. In comparing volumetric stability data by DMTA, the glass transition temperature(Tg) showed $137.88^{\circ}C$ at sample QC-20 resin cured by pack and press method and $139.78^{\circ}C$ at sample SR-Ivocap resin cured by continuous pressure injection method. Therefore sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in the dimensional stability at high temperature. 5. In comparing storage modulus data by DMTA, the storage modulus of sample SR-Ivocap resin cured by continuous pressure injection method was higher than that of sample QC-20 resin cured by pack and press method. So. sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in impact strength.

• Analytical Science and Technology
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• v.18 no.6
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• pp.469-474
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• 2005

This paper presents a quantitative method of sequential separation of $^{90}Sr$, $^{241}Am$ and Pu radionuclides with an anion exchange resin and a Sr-Spec resin. The Pu isotopes were purified with an anion exchange resin. The americium and strontium fractions were separated from the matrix elements with an oxalate co-precipitation method. Americium fraction was separated from the strontium fraction with iron co-precipitation method and purified from lanthanides with anion exchange resin. Strontium-90 was purified from other hindrance elements with the Sr-Spec resin after oxalate co-precipitation. The measurement of Pu and Am isotopes was carried out by an ${\alpha}$-spectrometer. Strontium-90 was measured by a liquid scintillation counter. The radiochemical procedure of $^{90}Sr$, $^{241}Am$ and Pu radionuclides investigated in this study has been validated by application to IAEA-Reference soils.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.248-254
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• 2005

This paper presents a quantitative method of sequential separation of $^{90}Sr,\;^{241}Am$ and Pu nuclides with an anion exchange resin and a Sr-Spec resin. The Pu isotopes were purified with an anion exchange resin. The americium and strontium fractions were separated from the matrix elements with an oxalate co-precipitation method. Americium fraction was separated from the strontium fraction with iron co-precipitation method and purified from lanthanides with anion exchange resin. Strontium-90 was purified from other hindrance elements with the Sr-Spec resin after oxalate co-precipitation. The measurement of Pu and Am isotopes was carried out by an ${\alpha}$-spectrometer. Strontium-90 was measured by a liquid scintillation counter. The radiochemical procedure of $^{90}Sr,\;^{241}Am$ and Pu nuclides investigated in this study has been validated by application to IAEA-Reference soils.

• Journal of Dental Rehabilitation and Applied Science
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• v.21 no.1
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• pp.59-67
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• 2005

The bond strength of denture base resin and resin teeth, is an important factor in the long term prognosis of dentures. The purpose of this study is to find an appropriate combination of commercial denture base resin and artificial resin teeth according to shear bond strength. In this study, the shear bond strength of various denture base resins (Vertex $RS^{(R)}$(Dentimax Ziest, Holland), $PERform^{(R)}$(Hedent GmbH., Germany), SR $IVOCAP^{(R)}$(Ivoclar AG, Schaan, Liechtenstein)) and resin teeth (SR Orthosit PE(Ivoclar AG, Schaan, Liechtenstein), $Trubyte^{(R)}$ $Biotone^{(R)}$(Dentsply, U.S.A.)) was evaluated. 1. In comparison of denture resin, the shear bond strength increased in the order of $IVOCAP^{(R)}$, $PERform^{(R)}$, Vertex $RS^{(R)}$. 2. In resin teeth, $Trubyte^{(R)}$ $Biotone^{(R)}$ showed higher strength, but there was no statistical difference between the groups. 3. According to loading direction, the lingual showed higher strength, but there was no statistical difference. 4. When using SR Orthosit PE, SR $IVOCAP^{(R)}$ showed significantly higher shear bond strength(p<0.05). 5. Fracture tendancy showed more cohesive fractures(59) than adhesive failures(13). $IVOCAP^{(R)}$ showed the most superior results statistically. $Trubyte^{(R)}Biotone^{(R)}$ showed the highest shear bond strength. When using the SR Orthosit PE, it is thought that $IVOCAP^{(R)}$ would present the most superior results.

• Analytical Science and Technology
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• v.33 no.6
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• pp.274-284
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• 2020

This study described the analytical method for simultaneous determination of 89Sr and 90Sr in liquid sample using automated separation system. Radiostrontium in 0.5 kg of liquid sample was concentrated as SrCO3 to reduce the volume of sample, and purified from the sample using Sr-resin 2 mL (BV, Bed volume). The behavior of Sr and interferences such as Ba, Ca and Y were estimated with various flow rate ranging from 1 to 4 mL min-1. The detailed procedure for the purification of Sr on Sr-resin was presented. The purified radiostronitum was measured in Cerenkov mode and then measured in Scintillation mode by mixing scintillation cocktail. The measured value in both modes were used to calculate the activity of 89Sr and 90Sr. The performance tests were carried out the lab-control-sample having various activity ratio of between 89Sr and 90Sr. The recovery of Sr was ranged from 68 to 94 %. The relative bias of 89Sr activity was ranged from -5 to 20 %, and it was ranged from -10 to 10 % for 90Sr.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.131-132
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• 2009

시멘트 고화체 중의 Sr-90 분석을 위한 시료 전처리 방법을 실험을 통하여 확립하였다. 시멘트 고화체 중의 Sr-90 과 같은 베타방출 핵종을 분석하기 위해서는 고화체 시료를 건조, 분쇄, 산처리, Sr-90 분리 및 LSC 를 이용한 Sr-90의 방사능 측정을 해야 한다. 이를 위하여 인수 고화체 시료를 전 처리 하기 전, SRM 1887a portland cement 를 사용하여 여러 산 처리 방법을 통하여 각 원소들의 회수율을 알아보았다. SRM 시료를 통하여 얻은 조건을 참조하여 실제 고화체 시료 5g 씩 3회의 7개 시료들을 전 처리하여 ICP-AES 를 통하여 각 원소들의 회수율을 비교하였다. 또한, 전처리 후 Sr 분리에 Sr-resin (Eichrom)를 이용하기 위해서는 Sr-resin 사용 시 많은 영향을 주는 칼슘의 량을 미리 알아야 한다, 이를 위하여 시멘트 고화체 중 50% 가까이 함유되어 있는 칼슘 량을 반 정량적으로 알아내기 위한 방법을 확립하였다.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.104-113
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• 1986

The ion exchange behaviour of the $Cs^{+1},\;Sr^{+2},\;and\;Th^{+4}$ in the system of $Cs^{+1},\;Sr^{+2},\;Th^{+4},\;and\;7Cl^{-}-H^{+}$ from Dowex HCR-W2, was examined in the loading and elution processes. $Th^{+4}$ was slowly adsorbed through the entire contact time between resin and solution and $Cs^{+1}\;and\;Sr^{2+}$ were adsorbed fast for the first few minutes of contact time. Because of the strong affinity of $Th^{+4}$, the longer contact time was allowed, the less amount of $Cs^{+1}\;and\;Sr^{2+}$ was adsorbed on the resin. The peak concentration of the resin phase $Cs^{+1}$ in the solution concentration of $Cs^{+1}:Sr^{+2}:Th^{+4}$ in the ratio of 2 : 2 : 1 in normality with total normality of 0.1N was produced at about 4 minutes of contact time and the peak time for $Sr^{+2}$ was 20 minutes. The loaded ions were eluted using hydrochloric acid. The loaded $Cs^{+1}$ was eluted at the low eluent concentration of less than 0.1N with less than 5% contamination of $Sr^{+2}$. The loaded $Th^{+4}$ was eluted at the high eluent concentration of greater than 1N. The best eluent concentration for eluting $Th^{+4}$ was 4N.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.210-230
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• 1995

To compare the wear resistance of four kinds of commercial acrylic resin teeth [SR-Orthosit PosterioresR(Ivoclar Co., Liechtenstein), Endura PosteriorR(Shofu Inc. Japan), trubyte IPN teethR(Dentsply International Inc., York,), Trubyte BiotoneR(dentsply Inermational Inc. Brazil) by means of the toothbrush abrasion method, the artificial resin teeth were embedded in epoxy resin with the occlusal surfaces aligned in one plane for a total of 40 blocks. There after, each lock was mounted in the arm of the toothbrush abrasion machine(K 236, Japan). Wear measurements were made on the three preconditioned states. Those were as follows : no treatment specimens, thermocycled specimens, and thermocycled specimens which were immeresed applied load of 400g during the buring the brushing cycle. At the end of the 30,000-stroke cycle, each specimen was removed, and weighed. The microhardness of four kinds of commercial resin teeth were determined by means of microhardness tester. Microhardness tests were performed on te no treatment specimens, thermocycled specimens, and thermocycled specimens with immersion in the denture cleansing solution. Finally, the comparison of thermal properties were perfomed using differential scanning calorimeter(DSC-1500). The following results were obtained : 1. In the case of no treatment teeth, the wear amount of endura Posterior(EN) was the greatest among the others(p<0.01), and the wear amount of three kinds of artificial resin teeth was increased in the order of Trubyte IPN teeth(IN), Trubyte Biotone(BN), SR-Orthosit Posteriores(SN) but there was no statistic significance(p>0.01). 2. The wear amount of Trubyte IPN teeth(IT) and Trubyte Biotone(BT), was increased due to thermocycling effect, but that of Endura Posteriores(ET) was decreased conversely(p<0.01). 3. Except for the SR-Orthosit Posteriores(STC), the wear amount of three kinds of artificial resing teeth(that is, ETC, ITC, BTC) was increased due to denture cleansing solution$(Cledent^R)$, but there was no statistic significance(p>0.01). But the wear amount of the SR-Orthosit Posteriores(STC) was the greatest among the others(p<0.01). 4. The wear amount of toothbrush was the greatest in case of contact with occlusal surface of SROrthosit Posteriores resin teeth(p<0.01). 5. the microhardness values(KHN) of the SR-Orthosit Posteriores was the highest among the experimental artificial resin teeth(p<0.01). 6. There was no relationship between microhardness valuse(KHN) and wear amount of four kinds of experimental artificial resin teeth(p<0.01). 7. The differential canning calorimetric property of four kinds of artificial resin teeth did not show endothermal or exothermal peak in the range of $100^{\circ}C$

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.71-78
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• 2019

Nuclear imaging is one of the most powerful measures for non-invasive diagnosis of myocardial vascular disease. Radionuclide such as ¹³N, ¹⁵O, ²⁰¹Tl and ⁸²Rb is used for the measurement of cardiac blood flow. ¹³N, ¹⁵O and ²⁰¹Tl are produced in cyclotrons while ⁸²Rb is obtained from generator. Rubidium (Rb), an alkali ion, behaves biologically like potassium, and accumulates in myocardial tissue. Rb has rapid blood clearance profile which allows the use of ⁸²Rb with a short physical half-life of 75 s for non-invasive evaluation of regional myocardial perfusion. There are several advantages of ⁸²Rb over other radioisotopes. An ultra-short half-life significantly reduces the exposure of patients to radiation and allows to repeat injections for studying the effects of medical intervention. As a positron emitter, ⁸²Rb allows positron emission tomography (PET) imaging which have shown superior diagnostic performances. ⁸²Rb can be produced from generator by decay of its parent ⁸²Sr. However, the preparation of ⁸²Sr is difficult, because appropriate purity is required to meet the specification of the product. Recently reported procedure from ARRONAX research institute showed that a Chelex-100 resin is sufficient for this purpose and additional column is not necessary. Whereas Brookhaven National Laboratory (BNL) procedure contains three ion exchange resin separation, including Chelex-100 resin. Currently, since ⁸²Sr production site is non-existent in Korea, Korea Atomic Energy Research Institute (KAERI) has plan to produce ⁸²Sr within specifications. We compared ⁸²Sr purification procedures reported from ARRONAX and BNL to investigate the most suitable procedure for our conditions.