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서울 시내 4년제 남자 대학생의 우울과 흡연량, 흡연기간, 니코틴 의존도와의 관계
박지영,박소영,이미숙,백수진,신의경,예혜련,오승진,장윤정,조혜진,김수지 이화여자대학교 간호과학대학 2003 이화간호학회지 Vol.- No.37
Background: With reports on the relation between smoking and depression appearing since 1980, it has become clear that depression is one of the psychodynamics of smoking, though there has been little or no progress made in the study of whether or not there is indeed a relation between depression and nicotine dependence. Purpose: The purpose of the study was to investigate the effects of depression on the amount and period of smoking and nicotine dependence among university man student smokers. Method: In periodical examination between 14 and 21, May, 2003, using 170 university male. The CES-D(Center for Epidemiologic Studies Depression) Scale and the FTQ(Fagerstrom Tolerance Qustionnaire) were utilized to measure the level of depression and nicotine dependency. The amount of smoking was calculated based on the number of cigarette used. Result: Results indicated that depression had something to do with amount of smoking. Nicotine dependence also was related to depression but total value was relatively low. finally the period of smoking had nothing to do with depression. Conclusion: The results of this study revealed that the amount of smoking of university man student smokers was very high. Both the amount of smoking and nicotine dependence were affected by levels of depression. Accordingly psychiatric nursing access such as emotional support is needed to manage depression and decrease smoking.
A Review of Chemical Speciation and Thermodynamic Studies of Plutonium in KAERI
Hye-Ryun Cho 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2
For the safety assessment of the high-level radioactive waste (HLRW) disposal, the thermodynamic data such as solubility products, formation constants of complexes, redox equilibrium constants of radionuclides, and their reaction enthalpy and entropy are required. In order to recommend and summarize the reliable data, thermodynamic databases (TDB) have been persistently developed through the OECD-NEA TDB projects and an updated TDB of actinides has been recently published in 2020. To date, reliable data for Pu reactions are scarce due to the possibility of coexistence of four different oxidation states, Pu(III-VI) by redox equilibria in solutions. To determine the thermodynamic data for the reaction of each Pu oxidation state, it is necessary to precisely control the oxidation state and quantitatively analyze all reactants, products and bi-products by using highly sensitive speciation techniques. Since 2004, the nuclear chemistry research team in KAERI has been focused on developing techniques for the sensitive chemical speciation by using laser-based spectroscopy and determining thermodynamic data of actinides such as U, Pu, Am. In this paper, chemical speciation and thermodynamic studies on Pu in KAERI are reviewed. A combination of a commercial spectrophotometer and a capillary cell was adopted for a sensitive chemical speciation of Pu(III-VI) in solutions. A sensitive detection of trace amount of Pu colloids was carried out with the laser-induced breakdown detection (LIBD) system. Pu(VI) complexation with hydroxide or carbonate ions were investigated under strong oxidation conditions controlled with hypochlorite (NaOCl). The solubility product of Pu(OH)3(am) and formation constant of Pu(III)-OH speices were determined by a combination of wet-chemistry experiments and several analysis methods of spectrophotometry, LIBD, radiometry under a strong reducing condition controlled by electrochemistry. More recently, we reported the reaction enthalpy and entropy data for the formation of Pu(OH)2+ and the dissolution of Pu(OH)3(am). A preliminary data for reaction between Pu(III) and organic matter will be presented.
Cho, Hye-Ryun,Youn, Young-Sang,Jung, Euo Chang,Cha, Wansik Royal Society of Chemistry 2016 Dalton Transactions Vol. No.
<▼1><P>This paper focusses on the determination of the thermodynamic data of Pu(iii) hydrolysis, which are important for a long-term safety assessment of high-level radioactive waste disposal in a deep geological system.</P></▼1><▼2><P>The aim of this work is to determine the solubility product of plutonium hydroxide under reducing conditions and to ascertain the stability of Pu(OH)3 (am) in water. Hydrolysis of Pu(iii) and solubility of Pu(OH)3 (am) were investigated at a constant ionic strength of 0.1 M NaClO4. Coulometric titration was adopted to adjust the pH of plutonium solutions, during which the electrolytic reducing conditions maintained the oxidation state of Pu(iii). Chemical speciation for dissolved plutonium was investigated using sensitive spectrophotometry coupled with a liquid waveguide capillary cell. The spectroscopic investigations indicated that dissolved Pu(iv), Pu(v), and Pu(vi) species were ignorable under these experimental conditions. The absorbance of Pu<SUP>3+</SUP> ions decreased due to hydrolysis of Pu(iii) but the absorbance of Pu(iii) hydrolysis species was not distinguishable. The formation constant for the first hydrolysis species (log <SUP>*</SUP><I>β</I>′1) determined in the present study is −6.62 ± 0.25. The non-crystalline structure of the plutonium precipitate was observed through X-ray diffraction. The solubility product of Pu(OH)3 (am), log <SUP>*</SUP><I>K</I>′s,0 is determined to be 15.23 ± 0.50. These results indicate a stronger tendency for the hydrolysis of Pu(iii) and higher stability (lower solubility) of Pu(OH)3 (am) compared to Am(iii).</P></▼2>
Cho, Hye-Ryun,Jung, Euo Chang,Cha, Wansik,Song, Kyuseok American Chemical Society 2013 ANALYTICAL CHEMISTRY - Vol.85 No.9
<P>A simple analytical method based on the simultaneous measurement of the luminescence of hexavalent uranium ions (U(VI)) and the Raman scattering of water, was investigated for determining the concentration of U(VI) in aqueous solutions. Both spectra were measured using a cw semiconductor laser beam at a center wavelength of 405 nm. The empirical calibration curve for the quantitative analysis of U(VI) was obtained by measuring the ratio of the luminescence intensity of U(VI) at 519 nm to the Raman scattering intensity of water at 469 nm. The limit of detection (LOD) in the parts per billion range and a dynamic range from the LOD up to several hundred parts per million were achieved. The concentration of uranium in groundwater determined by this method is in good agreement with the results determined by kinetic phosphorescence analysis and inductively coupled plasma mass spectrometry.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2013/ancham.2013.85.issue-9/ac303752t/production/images/medium/ac-2012-03752t_0006.gif'></P>
Dissolution Behaviors of ThO2 and PuO2 in the Synthetic Groundwater Contacted With Air
Hye-Ryun Cho,Minji Kim,Sangki Cho,Hee-Kyung Kim,Wansik Cha 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1
Dissolution behaviors of ThO2(cr) and PuO2(cr) in synthetic groundwater were investigated at room temperature (23 ? 2°C) under atmospheric conditions. The synthetic groundwater was prepared according to the chemical composition of the KURT-DB3 groundwater. The pH and Eh of the synthetic groundwater were pH 8.9 and 0.5 V, respectively, and the major components were Na, K, Ca, Mg, Si, Cl, SO4, F and HCO3 ions. A few mg of ThO2(cr) and PuO2(cr) powder were added in the synthetic groundwater and the concentrations of Th and Pu in supernatant were monitored for 5 months of reaction time. The concentrations of Th before and after ultracentrifugation were compared, while the solid-liquid phase separation of Pu samples could not be applied due to the small volume of sample solutions. The concentrations of Th and Pu were measured by ICP-MS and alpha spectrometry, respectively. Geochemist’s Work Bench (GWB, standard, 17.0) was applied for the modeling with ThermoChimie TDB v. 11a, which was updated with the latest NEA-TDB (vol. 14). Aqueous species distributions and solubility limiting solid phases of Th and Pu under the synthetic groundwater conditions were evaluated. The results of geochemical modeling indicate that aqueous Th-OH-CO3 ternary species and Pu(IV) species are dominant in solutions equilibrated with ThO2(s) and PuO2(am, hyd), respectively. The dissolution behaviors of ThO2(cr) and PuO2(cr) are comparable to the dissolution of ThO2(aged, logKsp = 8.5) and the oxidative dissolution of PuO2(am, hyd) in the presence of PuO2(coll, hyd), respectively.