• Title/Summary/Keyword: Rubidium

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Rubidium Market Trends, Recovery Technologies, and the Relevant Future Countermeasures (루비듐 시장 및 회수 동향에 따른 향후 관련 대응방안)

  • Sang-hun Lee
    • Resources Recycling
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    • v.32 no.3
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    • pp.3-8
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    • 2023
  • This study discussed production, demand, and future prospects of rubidium, which is an alkali group metal that is highly reactive to various media and requires carefulness in handling, but no significant environmental hazard of rubidium has been reported yet. Rubidium is used in various fields such as optoelectronic equipment, biomedical, and chemical industries. Because of difficulty in production as well as limited demand, the transaction price of rubidium is relatively high, but its detail information such as market status and potential growth is uncertain. However, if the mass production of versatile ultra-high-performance equipment such as quantum computers and the necessity of rubidium use in the equipment are confirmed, there is a possibility that the rubidium market will expand in the future. Rubidium is often found together with lithium, beryllium, and cesium, and may be present in granite containing minerals such as lepidolite and pollucite, as well as in seawater and industrial waste. Several technologies such as acid leaching, roasting, solvent extraction, and adsorption are used to recover rubidium. The maximum recovery efficiency of the rubidium from the sources and the processing above is generally high, but, in many practices, rubidium is not the main recovery target, and therefore the actual recovery effects should depend on presence of other valuable components or impurities, together with recovery costs, energy consumption, environmental issues, etc. In conclusion, although the current production and consumption of rubidium are limited, with consideration of the possible market fluctuations according to the emergence of large-scale demand sources, etc., further investigations by related institutions should be necessary.

Stress/Rest Tc-99m-MIBI SPECT in Comparison with Rest/Stress Rubidium-82 PET (휴식/부하 심근 Rubidium-82 양전자단층촬영과 부하/휴식 심근 Tc-99m-MIBI 단일광자단층촬영의 비교)

  • Lee, D.S.;Kang, K.W.;Lee, K.H.;Jeong, J.M.;Kwark, C.;Chung, J.K.;Lee, M.C.;Seo, J.D.;Koh, C.S.
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.1
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    • pp.31-40
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    • 1995
  • We compared stress/rest myocardial Tc-99m-MIBl tomographic image findings with rest/stress rubidium-82 tomographic images. In 23 patients with coronary artery disease (12 of them received bypass grafts before) and 6 normal subjects, rest rubidium PET study was performed : rubidium-82 and Tc-99m-MIBI were injected simultaneously to each patient after dipyridamole stress for rubidium PET and MIBI SPECT; and rest MIBI SPECT was performed 4 hours thereafter. We scored segmental decrease of rubidium or MIBI uptakes into 5 grades for 29 segments from 3 short-axis, vertical and horizontal slices. Scores were summed for each major arterial territory. When more score than two grade-2's or one grade-3 was considered as the cue for significant stenosis for major arterial territories, 67% of 46 stenosed arteries were found with MIBI studies and 78% of them by rubidium studies. Fourteen among 28 grafted arterial territories of 12 post-CABG patients were found normal with both rubidium and MIBI. Segmental scores were concordant between rubidium and MIBI in 72% of 709 stress segments and in 80% of 825 rest segments. Stress rubidium segmental scores were less than stress MIBI scores in 9%, so were rest rubidium scores. Stress rubidium scores were more than stress MIBI scores in 20% of segments, and rest rubidium segmental scores were more than rest MIBl scores in 11%. Rank correlations (Spearman's rho's more than 0.7(stress) and 0.5(rest), slopes (MIBI/rubidium) around 0.7(stress) and 0.9 (rest)) suggested deeper and wider defects in stress with rubidium. Slope over 1 (MIBI/rubidium) with LAD segemental scores at rest and 7 territories which had much larger score with MIBI revealed exaggeration of rest defects with rest MIBI in same-day stress/rest study. Difference scores (stress-rest for each territory) suggesting Ischemia were larger with rubidium (slope of MIBI/rubidium around 0.45). As has been implied by animal or separate-day-human studies, these segmental analyses with simultaneous examination in patients told that rubidium PET flow studies disclose ischemia more often than MIBI studies and that rest MIBI studies in same-day stress/rest-sequence gave a little larger rest defect than they would have shown.

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Two Crystal Structures of Dehydrated Fully $Ca^{2+}$-Exchanged Zeolte A Reacting with Rubidium Vapor

  • Song, Seong-Hwan;Kim, Yang
    • Bulletin of the Korean Chemical Society
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    • v.14 no.2
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    • pp.258-262
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    • 1993
  • Two single crystals of fully dehydrated $Rb^+$ -exchanged zeolite A have been prepared by the reduction of all $Ca^{2+}$ ions in dehydrated $Ca_6$-A by rubidium vapor. Their structures were determined by single crystal X-ray diffraction methods in the cubic space group Pm3m (a=12.160(2) $^{\AA}$ and 12.166(2) $^{\AA}$) at 22(1)$^{\circ}$C. In these structures, 12.4(2) to 13.3(2) Rb species are found per unit cell, more than 12 Rb$^+$ ions needed to balance the anionic charge of the zeolite framework, indicating that the sorption $Rb^0$ has occurred. In each structure, three $Rb^+$ ions per unit cell are located at the centers of the 8-rings. Six to eight $Rb^+$ ions are found opposite the 6-rings on threefold axes, and three $Rb^+$ ions are found in a sodalite unit. About 0.5 $Rb^+$ ion lies opposite a 4-ring. The structural analysis indicates the presence of a triangular rubidium cluster in the sodalite cavities. The triangular rubidium clusters may be stabilized by the coordination to two and/or three rubidium ions in the large cavity. Therefore, this cluster may be viewed as $(Rb_5)^{4+}$ and/or $(Rb_6)^{4+}$.

Study of the Compressed and Expanded Liquid Rubidium with the Optimized Nonlocal Model Potential

  • 강홍석;박성호
    • Bulletin of the Korean Chemical Society
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    • v.20 no.11
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    • pp.1288-1294
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    • 1999
  • We show that Shaw's optimized nonlocal model potential (OMP) in combination with the perturbative hyper-netted-chain equation for pair correlation functions can be successfully applied to predict pair structures of compressed and expanded liquid rubidium. For compressed rubidium, it is possible to apply the OMP to a state for which the model radius is even close to the Wigner-Seitz radius. In addition, our results are parallel to those from Chihara and Kahl's quantal hypernetted-chain equation in that it supports the uniform compression model up to 6.1 GPa. Calculation also shows that the pair structure is relatively insensitive to the choice of the exchange-correlation function for the electron liquid. Discussions are also given for compressed and expanded cesium.

Production of Hyperpolarized 129Xe Using Spin Exchange Optical Pumping

  • Kavtanyuk, Vladimir Vladimirovich;Kim, Wooyoung;Ando, Yu;Chebotaryov, Sergey;Seon, Yonggeun;Tan, Joshua Artem
    • Journal of the Korean Physical Society
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    • v.73 no.10
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    • pp.1458-1465
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    • 2018
  • We present a constructed setup for polarizing $^{129}Xe$ noble gas. Hyperpolarized $^{129}Xe$ has been obtained via spin exchange with an optically pumped rubidium vapor. Optical pumping is based on polarizing the valence electron of rubidium by the resonant absorption of a circularly polarized laser light. The magnetic field of 30 G was used for obtaining $^{129}Xe$ polarization. The apparatus for detecting polarization is a nuclear magnetic resonance spectrometer. The highest $^{129}Xe$ polarization of 54% has been obtained using 60 W circularly polarized laser light with wavelength of 794.7 nm. The measured longitudinal relaxation time of the hyperpolarized $^{129}Xe$ was 72.3 minutes.

The Crystal Structure of Rubidium Hydrogen Carbonate ($RbHCO_3$) (炭酸水素루비듐의 結晶構造)

  • Kim Moon Il
    • Journal of the Korean Chemical Society
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    • v.13 no.2
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    • pp.131-136
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    • 1969
  • The crystal structure of rubidium hydrogen carbonate has been determined by single crystal X-ray diffraction method. the crystals are monoclinic with a = 15.05 $\AA$, b = 5.83 $\AA$, c = 4.02 $\AA$, and $\beta$ = $107^{\circ}.$ There are four chemical units per unit cell and the space-group was fixed as $C2-C^3_2$. Patterson and trial-and-error methods gave the approximate structure and its refinements were made by two-dimentional Fourier summation. The Co3 group is planar with tshhe C-O distances of 1.32 $\AA$, 1.32 $\AA$, and 1.33 $\AA$ within experimental error and the two $CO_3$ groups are linked together to form a complex anion [$H_2C_2O_6$] with the O-H${\cdot}{\cdot}{\cdot}$O distance, 2.53 $\AA.$ Two molecules of $RbHCO_3$ make the dimer structure with two hydrogen bonds. The values of reliability factor for $F_{(hol)}$, $F_{(hko)}$and $F_{(okl)}$are 0.15, 0.15 and 0.17 respectively. Each rubidium ion has eight oxygen neighbours with the Rb-O distances of 2.84~3.11 $\AA.$.

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Time-Error Prediction of Rubidium Atomic Clock according to the Elapsed Time (루비듐 원자시계의 경과시간에 따른 시간오차 예측)

  • 김영범;정낙삼;박동철
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.3
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    • pp.439-445
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    • 2001
  • In this paper, we propose a method that can minimize time-error when a commercial rubidium atomic clock is used as a portable reference clock. A linear interpolation method which was widely used is not based upon long-term stability, but our new method is considered to reduce time error. The comparison results between two method have shown that time error of our new approach considering with long-term stability is better than that of linear interpolation method within observation duration about one and half days. In addition, when the role of a rubidium atomic clock as a portable reference clock is completed within 12 hours, our new method can provide at most maximum time-error of 10 ns which is shorter than 15 ns in conventional method.

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