• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.293-297
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• 1993

Chitosan is a natural chelating agent. It is derived from chitin which is a cellulose-like biopolymer distributed widely in nature, expecially in shellfish, insects, fungi, and yeast. The purpose of the present study is to investigate whether orally given water soluble chitosan can eliminate intraperitoneally injected radiostrontium (Sr-85) in mice. Water soluble chitosan and usual food was mixed as 10:90 by weight. The mixed food were fed for 60 (group 1) or 90 days (group 2). No chitosan was given to the control group. Each group consists of 5 mice. Sr-85 ($0.2{\mu}Ci$) was intraperitoneally injected after completion of prefeeding of usual or mixed food. The same food was given for more 5 days. The animals were sacrificed at the 6th day. Isolated spines, skulls, femurs, tibias, teeth, and tails were counted by a gamma counter. The retention of Sr-85 in bones was significantly lowere in the prefeeding groups (p<0.01). It was lowest in the 90 day prefeeding group. Therefore, prefeeding of water-soluble chitosan was effective on the removal of intraperitoneally injected radiostrontium.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.816-819
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• 1995

(Ba$_{1-x}$ , Sr$_{x}$)TiO/$_3$thin films on Pt/Ti/SiO$_2$/Si substrates were prepared by LP MOCVD(Low Pressure Metal-Organic Chemical Vapor Deposition). The crystalinity of BST deposit had a (100) preferred orientation with increasing deposition temperature due to surface diffusion. BST films deposited at 90$0^{\circ}C$ showed a dielectric constant of 365 and a dissipation factor of 0.052 at a frequency of 100kHz. The chance of capacitance of the films with applied voltage was small, showing paraelectric properties. BST film deposited at 90$0^{\circ}C$ had a charge storage density of 60 fc/${\mu}{\textrm}{m}$$^2$at a field of 0.2MV/cm and the leakage current density of 20 nA/$\textrm{cm}^2$ at a field of 0.15 MV/cm.cm.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.362-366
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• 1989

For the effective use of soymilk residue(SR), by-product of soymilk production, Wheat Doenjang made of Wheat flour-SR koji(WFSR koji) and soybean was manufactured. As the results, the contents of reducing sugar were increased till 50 days in all samples and decreased thereafter during aging of the mash. The contents of amino nitrogen were prominently increased till 50 days, but increasing ratio was slightly slowdowned thereafter. The higher the mixing ratio of SR was, the less the contents of reducing sugar and amino nitrogen were. The contents of total acid were also prominently increased till 40 days, but were slowdowned thereafter and the differences among all treatments were small. As the mixing ratio of SR was increased, the yellowness and the redness were increased and the lightness was decreased in 80 days aged samples. In sensory evaluation of 90 day aged samples, control [WFSR koji 100 (WF: SR ; 100 : 0), soybean 100] was the best in soy sprout Doenjang soup. As the mixing ratio of SR was increased, the taste was dropped slightly but no significant differences were obtained between control and sample A[WFSR koji 125 (WF: SR ; 100 : 25), soybean 75], sample B[WFSR koji 150(WF: SR ; 100 : 50), soybean 50] and sample C[WFSR koji 175 (WF: SR ; 100 : 75), soybean 25], sample C and sample D[WFSR koji 200(WF: SR ; 100 : 100), soybean 0].

• Journal of Korean Society of Environmental Engineers
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• v.37 no.3
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• pp.145-151
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• 2015

In order to remove Sr ions and Cs ions from aqueous solution, PS-zeolite beads were prepared by immobilizing zeolite with polysulfone (PS). The prepared PS-zeolite beads were characterized by SEM, XRD, FT-IR, and TGA. The optimum condition to prepare PS-zeolite beads was 1.25 g of PS content and 2 g of zeolite A. The removal efficiencies of Sr and Cs ions by the PS-zeolite beads increased as the solution pH increases and nearly reached a plateau at pH 4. The PS-zeolite beads prepared in this study showed a remarkably high selectivity for Sr ion and Cs ion under the coexistence of ions such as $Na^+$, $K^+$, $Mg^{2+}$, and $Ca^{2+}$. Zeolite particles detached from the PS-zeolite beads were not observed on this experiments, and also the PS-zeolite beads maintained the morphological structure on a SEM image. The removal efficiencies of Sr ions and Cs ions by PS-zeolite beads were maintained over 90% even after five adsorption-desorption cycles. These results implied that the prepared PS-zeolite beads could be an available adsorbent for the adsorption of Sr and Cs ions. These results suggest that the PS-zeolite can potentially be used as an adsorbent in radioactive ions removal for the treatment of industrial wastewater.

• Journal of Chest Surgery
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• v.46 no.2
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• pp.117-123
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• 2013

Background: We examined perioperative predictors of sustained sinus rhythm (SR) in patients undergoing the Cox maze operation and concomitant cardiac surgery for structural heart disease. Materials and Methods: From October 1999 to December 2008, 90 patients with atrial fibrillation (AF) underwent the Cox maze operation and other concomitant cardiac surgery. Eighty-nine patients, all except for one postoperative death, were followed-up with serial electrocardiographic studies, 24-hour Holter monitoring tests, and regular echocardiographic studies. Results: Eighty-nine patients undergoing the maze operation were divided into two groups according to the presence of SR. At the time of last follow-up (mean follow-up period, $51.0{\pm}30.8$ months), 79 patients (88.8%) showed SR (SR group) and 10 patients (11.2%) had recurrent AF (AF group). Factors predictive of sustained SR were the immediate postoperative conversion to SR (odds ratio, 97.2; p=0.001) and the presence of SR at the 6th month postoperatively (odds ratio, 155.7; p=0.002). Duration of AF, mitral valve surgery, number of valves undergoing surgery, left atrial dimension, and perioperative left ventricular dimensions and ejection fractions were not predictors of postoperative maintenance of SR. Conclusion: Immediate postoperative SR conversion and the presence of SR at the 6th postoperative month were independent predictors of sustained SR after the maze operation.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.530-531
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• 2005

• Journal of the Korean Ceramic Society
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• v.29 no.11
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• pp.900-904
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• 1992

High temperature electrical conductivity was measured for perovskite La0.98Sr0.02MnO3 at 200~130$0^{\circ}C$ as a function of Po2 and 1/T. Perovskite La1-xSrxMnO3 system is the typical oxygen electrode in solid oxide fuel cell (SOFC). Acetate precursors were used for the preparation of mixed water solution and the calcined powders were reacted with Na2CO3 flux in order to obtain highly reactive powders of perovskite La0.98Sr0.02MnO3. The relative density was greatly increased above 90% because of the homogeneous sintering. From the conductivity ($\sigma$)-temperature and conductivity-Po2 at constant temperature, the defect structure of La0.98Sr0.02MnO3 was discussed. From the slope of 1n($\sigma$) vs 1/T, the activation energy of 0.069 and 0.108eV were evaluated for above 40$0^{\circ}C$, respectively. From the relationship between $\sigma$ and Po2, it was found that the decomposition of La0.98Sr0.02MnO3 was occurred at 10-15.5 atm(97$0^{\circ}C$) and 10-11 atm(125$0^{\circ}C$). It is supposed that the improvement of p-type conductivity may be leaded by the increase of Mn4+ concentration through the substitution of divalent/monovalent cations for La site in LaMnO3.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1488-1490
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• 2002

The (Bi,Ba,Sr)$TiO_3$[BBST] thin films were fabricated on Pt/Ti/$SiO_2$/Si substrate by RF sputtering method. We investigated the effects of Ar/$O_2$ rates on the structural properties of BBST thin films. Decreasing the $O_2$ rates, the intensity of $BaBi_4Ti_4O_{15}$ and $Bi_4Ti_3O_{12}$ peaks were increased but the $(Ba_{0.5}Sr_{0.5})TiO_3$ peak was decreased. In the case of BBST thin films deposited with condition of 90/10 (Ar/$O_2$) ratio, the composition of Ba/Sr/Bi was 0.35/0.4/0.25. Also, in the BBST thin films deposited with condition of 80/20(Ar/$O_2$) ratio, the composition of Br,Sr and Ti were relatively uniform. But the component of Bi and Ti were diffused into the Pt layers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.518-521
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• 2003

Bi$_2$Sr$_2$Ca$_{n-1}$Cu$_{n}$O$_{x}$ superconducting thin films have been fabricated by atomic layer-by-layer deposition using IBS(Ion Beam Sputtering) method. During the deposition, 90 mol% ozone gas of typical pressure of 1~9 $\times$ 10$^{-5}$ Torr are supplied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal out that a buffer layer with some different compositions is formed at the early deposition stage of less than 10 units cell and then Bi-2201 oriented along the c-axis is grown.grown.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.259-260
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• 2006

$Bi_2Sr_2Ca_{n-1}Cu_nO_x$ superconducting thin films have been fabricated by atomic layer-by-layer deposition using IBS(Ion Beam Sputtering) method During the deposition, 90 mol% ozone gas of typical pressure of $1{\sim}9{\times}10^{-5}$ T orr are supplied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal out that a buffer layer with some different compositions is formed at the early deposition stage of less than 10 units cell and then Bi-2201 oriented along the c-axis is grown.