• Title/Summary/Keyword: Sr-90

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Efficient removal of radioactive waste from solution by two-dimensional activated carbon/Nano hydroxyapatite composites

  • El Said, Nessem;Kassem, Amany T.
    • Membrane and Water Treatment
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    • v.9 no.5
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    • pp.327-334
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    • 2018
  • The nano/micro composites with highly porous surface area have attracted of great interest, particularly the synthesis of porous and thin film sheets of high performance. In this paper, an easy method of cost-effective synthesis of thin film ceramic fiber membranes based on Hydroxyapatite, and activated carbon by turned into studied to be applied within the service-facilitated the transport of radioactive waste such as $^{90}Sr$, $^{137}Cs$ and $^{60}Co$) as activated product of radioisotopes from ETRR-2 research reactor and dissolved in 3M $HNO_3$, across a thin flat-sheet supported liquid membrane (TFSSLM). Radionuclides are transported from alkaline pH values. The presence of sodium salts in the aqueous media improves in $HNO_3$, the lowering of permeability because the initial $HNO_3$ concentration is improved. The study some parameters on the thin sheet ceramic supported liquid membrane. EDTA as stripping phase concentration, time of extraction and temperature were studied. The study of maximum permeability of radioisotopes for all parameters. The pertraction of a radioactive waste solution from nitrate medium were examined at the optimized conditions. Under the optimum experimental 98.6-99.9% of $^{90}Sr$, 79.65-80.3% of $^{137}Cs$ and $^{60}Co$ 45.5-55.5% in 90-110 min with were extracted in 10-30 min, respectively. The process of diffusion in liquid membranes is governed by the chemical diffusion process.

Solidification of high level waste using magnesium potassium phosphate compound

  • Vinokurov, Sergey E.;Kulikova, Svetlana A.;Myasoedov, Boris F.
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.755-760
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    • 2019
  • Compound samples based on the mineral-like magnesium potassium phosphate matrix $MgKPO_4{\times}6H_2O$ were synthesized by solidification of high level waste surrogate. Phase composition and structure of synthesized samples were studied by XRD and SEM methods. Compressive strength of the compounds is $12{\pm}3MPa$. Coefficient of thermal expansion of the samples in the range $250-550^{\circ}C$ is $(11.6{\pm}0.3){\times}10^{-6}1/^{\circ}C$, and coefficient of thermal conductivity in the range $20-500^{\circ}C$ is $0.5W/(m{\times}K)$. Differential leaching rate of elements from the compound, $g/(cm^2{\times}day)$: $Mg-6.7{\times}10^{-6}$, $K-3.0{\times}10^{-4}$, $P-1.2{\times}10^{-4}$, $^{137}Cs-4.6{\times}10^{-7}$; $^{90}Sr-9.6{\times}10^{-7}$; $^{239}Pu-3.7{\times}10^{-9}$, $^{241}Am-9.6{\times}10^{-10}$. Leaching mechanism of radionuclides from the samples at the first 1-2 weeks of the leaching test is determined by dissolution ($^{137}Cs$), wash off ($^{90}Sr$) or diffusion ($^{239}Pu$ and $^{241}Am$) from the compound surface, and when the tests continue to 90-91 days - by surface layer depletion of compound. Since the composition and physico-chemical properties of the compound after irradiation with an electron beam (absorbed dose of 1 MGy) are constant the radiation resistance of compound was established.

Tunable Dielectric Properties and Curie Temperature with BST Thick Films (BST 후막의 가변 유전특성과 큐리온도에 관한 연구)

  • Kim In-Sung;Song Jae-Sung;Min Bok-Ki;Jeon So-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.8
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    • pp.392-398
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    • 2006
  • The properties of tunable dielectric materials on RF frequency band are important high tunability and low loss for RF variable devices, variable capacitor, phased array antenna and other components application. Various composite of BST(barium strontium titanate) ratio combined with other non-electrical active oxide ceramics have been formulated for such uses. We present the tunable properties and Curie temperature on BST thick films. The grain growth of the weight ratio of $BaTiO_3$ increased. This can be explained by the substitute $Sr^{2+}$ ion for $Ba^{2+}$ ion in the $BaTiO_3$ system. The Curie temperature was shifted to lower temperature with increasing $SrTiO_3$in the $BaTiO_3-SrTiO_3$ system, because of decreasing the lattice constant. Also, the dielectric constant, tunability and K-factor of $(Ba_xSr_{1-x})TiO_3$ at over the Curie temperature decreased, at over the $60^{\circ}C$ fixation, maximum dielectric constant at Curie temperature and hence sharper phase transformation occurred at Curie temperature. The result were interpreted as a process of internal stress relaxation resulting form the increase of $90^{\circ}$ domains induced the BST. As a result, It is concluded that over the Curie temperature, frequency response and DC field effect for the tunable properties of BST thick film are suppressed by the transition broadening. For the application of tunable devices, that the curie temperature was investigated to be increased.

Integration of Ayurvedic formulations with iron folic acid in the treatment of nutritional anaemia among school going adolescents of Dehradun District

  • Prakash, Vaidya Balendu;Prakash, Shyam;Sharma, Rajesh;Prakash, Megha;Prakash, Shikha;Parmar, Kiran
    • CELLMED
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    • v.6 no.1
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    • pp.5.1-5.5
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    • 2016
  • Combating anaemia is a global public health challenge of the developing world. Nutritional anaemia is a serious health problem faced by Indian school children. An investigation was taken up to study the effect of non iron containing Ayurvedic preparation Sootshekhar Rasa (SR) plus Sitopaladi Churna (SC) along with iron and folic acid (IFA) for improving nutritional anaemia among adolescent school going students of Dehradun district in Northern India. The blinded, controlled randomized trial comprised of 820 adolescents anaemic students aged 11 - 18 years. The anaemic students were randomly divided into 4 groups, students of group I (control) received starch, group II, III, and IV students received daily dose of (SR 250 mg + SC 400 mg), IFA and (SR 250 mg + SC 400 mg) + IFA, respectively. All the students received treatment for 90days and were followed up for next 180days. At the end of follow-up (day 270), significant increase of haemoglobin (Hb) level from the base line was recorded in all treatment groups. The maximum gain in Hb concentration was noted in group IV (10.1 ± 0.6 g/L), which was significantly higher than any other group. There were 123 drop-outs; however, no major side effect of treatment was noted in any student. We conclude that daily dose of (SR 250 mg + SC 400 mg) along with IFA can produce sustainable improvement of nutritional anaemia in adolescent students.

IL-4-deficient Mice Aggravate Hypersensitivity Pneumonitis

  • Hwang, Su-Jin;Chung, Doo-Hyun
    • IMMUNE NETWORK
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    • v.8 no.3
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    • pp.90-97
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    • 2008
  • Background: Hypersensitivity pneumonitis (HP) comprises a group of lung diseases resulting from repeated inhalation of various antigens such as Saccharopolyspora rectivirgula (SR). HP is categorized as a Th1 disease. Therefore, it has been suggested that IL-4, Th2 type cytokine, plays a protective role in the development of HP. However, the functional role of IL-4 in HP has not been extensively investigated in vivo. Therefore, we investigated the functional role of IL-4 in HP using IL-4 knockout (KO) mice. Methods: HP was induced by repeated exposure to SR in C57BL/6 (B6) and IL-4 KO (C57BL/6 background) mice. Results: IL-4 KO mice aggravated HP in terms of histological alteration, SR-specific immune responses, and inflammatory cell infiltration in the lungs compared with B6 mice. IL-4 KO mice produced high levels of IFN-${\gamma}$, TGF-${\beta}$ and TNF-${\alpha}$ in the lungs, whereas B6 mice showed the enhanced production of IL-4. Moreover, chemokines such as MIP-1${\alpha}$, MCP-1, and RANTES were highly expressed in IL-4 KO mice. IFN-${\gamma}$-secreting CD4, CD8 T cells, and neutrophils were enhanced in the bronchoalveolar lavage fluid (BALF) of IL-4 KO mice than those of B6 mice. The administration of recombinant(r) IL-4 restored these immunologic parameters in IL-4 KO mice. Conclusion: These results indicate that IL-4 plays a suppressive role in SR-induced HP by attenuating Th1-dominant immune responses.

A pH-specific Released Formulation Study of WHW Extract for Therapeutics of Renal Failures (신부전 치료제 WHW 엑스의 pH 특이적인 방출 제형 연구)

  • So, Jae-Woo;Kang, Hee-Chul;Park, Yong-Ki;Kim, Young-Ho;Kang, Jong-Seong;Cho, Cheong-Weon
    • Journal of Pharmaceutical Investigation
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    • v.39 no.4
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    • pp.257-261
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    • 2009
  • Effective therapeutics for renal failures have not yet been developed until now. Recently, there was a report showing that Wen-pi-tang-Hab-Wu-ling-san (WHW) prescriptions had the potential to prevent renal failures through the increased expression of HSP-27 and HSP-72 after ischemia/reperfusion. Therefore, formulation studies by pH-specific released systems were carried out to exhibit the optimal activity of WHW prescriptions in this study. WHW prescriptions were separately extracted using water into two parts of stomach-released (SR) and intestine-released (IR) extracts. Subsequently, the double-layered tablet was prepared using the SR extracts and pharmaceutical additives and enteric-coated IR tablet. Dissolution studies were carried out to figure out the release of cinnamic acid and icarrin from SR tablet, IR tablet and double-layered tablet, respectively. The complete release of cinnamic acid from SR tablet showed 90min after dissolution in pH 1.2 and insignificant drug released from IR tablet. As well as, icarrin from IR tablet completely released in pH 6.8 and 7.4 as enteric-coating film dissolved.

Characteristics of the Decontamination by the Melting of Aluminum Waste (용융에 의한 알루미늄 폐기물의 제염 특성)

  • Song Pyung-Seob;Choi Wang-Kyu;Min Byung-Youn;Kim Hak-I;Jung Chong-Hun;Oh Won-Zin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.2
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    • pp.95-104
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    • 2005
  • Effects of the aluminum melting temperature, melting time and a kind of flux agents on the distribution of surrogate nuclide were investigated in the electric furnace at the aluminum melting including surrogate radionuclides(Co, Cs, Sr) in order to establish the fundamental research of the melting technology for the metallic wastes from the decommissioning of the TRIGA research reactor. It was verified that the fluidity of aluminum melt was increased by adding flux agent but it was slightly varied according to the sort of flux agents. The results of the XRD analysis showed that the surrogate nuclides move into the slag phase and then they were combined with aluminum oxide to form more stable compound. The weight of the slag generated from aluminum melting test increased with increasing melting temperature and melting time and the increase rate of the slag depended on the kind of flux agents added in the aluminum waste. The concentration of the cobalt in the ingot phase decreased with increasing reaction temperature but it increased in the slag phase up to 90$\%$according to the experimental conditions. The volatile nuclides such as Cs and Sr considerably transferred from the ingot phase to the slag and dust phase.

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Quantitative Analysis of Trace Metals in Lithium Molten Salt by ICP-AES (ICP-AES를 이용한 리튬 용융염내의 미량 금속성분원소 정량에 관한 연구)

  • Kim, Do-Yang;Pyo, Hyung-Yeal;Park, Yong-Joon;Park, Yang-Soon;Kim, Won-Ho
    • Analytical Science and Technology
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    • v.13 no.3
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    • pp.309-314
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    • 2000
  • The quantitative analysis of various trace metals including fission products in lithium molten salts has been performed using a inductively coupled plasma atomic emission spectrometer (ICP-AES). The spectral interferences of lithium content, 500, 1,000 and 2,000 mg/L, in the sample solution were investigated using an optimum wavelength for the respective metal species. As a result, the line intensities for Y, Nd, Sr, and La had no influences from the lithium content up to 2,000 mg/L, while Mo, Ba, Ru, Pd, Rh, Zr and Ce showed spectral interferences of 10% to 50%. The group separation of metals from lithium in the molten salts solution was carried out by adding ammonia water into the solution. The recovery of Ru, Y, Rh, Zr, Nd, Ce, La and Eu was found to be over 90%, while Mo, Ba, Pd, and Sr provided low recovery percentages.

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Sorption Characteristics of Strontium and Nickel on Mackinawite According to pH Variations in Alkaline Conditions (염기 환경에서 pH 변화에 따른 맥키나와이트 광물에 스트론튬과 니켈의 수착 특성)

  • Park, Chung-Kyun;Park, Tae-Jin;Lee, Seung-Yup;Lee, Jae-Kwang
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.1
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    • pp.73-81
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    • 2020
  • Strontium (90Sr) and nickel (59Ni) have been considered as key radionuclides in the safety assessment of radioactive waste disposal. Through various efforts to impede the migration of radioactive nuclides underground, it has been established that some minerals generated from the corrosion of the waste containers have a positive chemical interaction with these radionuclides. Among these minerals we selected mackinawite (FeS), an iron and sulfur compound, and performed a sorption experiment for the Sr and Ni in FeS under anoxic and alkaline conditions by reflecting deep underground environments. The effects of pH on sorption were likewise investigated in the pH range of 8 ~ 12. As a result, it was found that strontium failed to exhibit a good sorption capacity in a weak alkaline range, while nickel showed a noticeably higher sorption affinity over the entire experimental pH range. Moreover, we determined that as the pH increased in the solution, the distribution coefficients (Kd) were increased for both nuclides, which reflects when an alkalinity increses, the surface of the mineral charges much negatively by detaching the hydrogen or cations on the mineral surface. Thus, it can be concluded that the cationic nuclides of Sr and Ni can attach easily to the mineral under strong alkalinity.

Anisotropy and Dose Equivalents Conversion Factors for the Unmoderated $^{252}Cf$ Source (비감속 $^{252}Cf$ 중성자선원에 대한 비등방성교정인자 및 선량당량환산인자)

  • Jeong, Deok-Yeon;Chang, Si-Young;Yoon, Suk-Chul;Kim, Jong-Soo
    • Journal of Radiation Protection and Research
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    • v.18 no.2
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    • pp.71-79
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    • 1993
  • Form the pure Maxwellian distribution(kT= 1.42MeV), the effects upon calibration factors of encapsulating a $^{252}Cf$ spontaneous fission neutron source were investigated to establish a standard neutron field in the Secondary Standard Dosimetry Laboratory at Korea Atomic Energy Research Institute(KAERI). A Monte Carlo code MCNP was used in simulating the encapsulation SR-Cf-100 and SR-Cf-1273 to be real conditions. The anisotropy(FI) and fluence-to-dose equivalents conversion factors$(H/{\Phi})$ were evaluated and compared with other results. As the results, the FI was determined to be 1.061 at ${\theta}=90^{\circ}$ with ${\pm}0.2%$ statistical error and the $(H/{\Phi})$ was evaluated to be $333.9 [pSv\;cm^2]\;with\;{\pm}0.5%$ statistical error, which is lower by 1.8% than that recommended by the ISO 8529. This means physically that the neutron spectrum of the unmoderated $^{252}Cf$ source in KAERI is a little more softened than that by the ISO.

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