• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.653-660
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• 2022

The interaction between UN and CdCl₂ in the LiCl-KCl molten eutectic was studied at 1023 K. The chlorination was monitored by sampling and recording the redox potential of the medium. At 1023 K the chlorination of UN with cadmium chloride in the molten LiCl-KCl eutectic proceeds completely and results in the formation of uranium chlorides. The melts of the LiCl-KCl-UCl₃ or LiCl-KCl-UCl₄ compositions can be obtained by the end of experiment depending on the presence of metallic cadmium in the reaction zone. The higher the concentration of the chlorinating agent, the faster the reaction rate. At [CdCl₂]/[UN] = 1.65 (10% excess) the reaction proceeds to completion in about 7.5 h. At [CdCl₂]/[UN] = 7 the complete chlorination takes 2.5-3 h.

• Membrane and Water Treatment
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• v.15 no.2
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• pp.89-98
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• 2024

The ability of Zizyphus lotus stem powder (ZLSP) to remove Pb (II) and Cd (II) ions from an aqueous solution was evaluated. The present phenomenon of biosorption was revealed to depend on pH, biosorbent dosage, temperature, initial ionic concentration, time of contact and biosorbent's particle size. The sorption process was exothermic (∆H°<0), and showing a strong Pb(II)/Cd(II)-ZLSP affinity (∆S°>0). Gibbs free energy data (∆G°<0, and decreases as temperature increase) reveals that the process studied is characterized by its feasibility and spontaneous nature. The best fits of the equilibrium data were obtained by the Temkin model and the Langmuir model. The maximum Pb(II)/Cd(II)-ZLSP biosorption capacities were 33.02 mg/g for Pb (II) and 20.73 mg/g for Cd (II). The pseudo-second order model was the most appropriate for fitting the kinetic data. The characterization of the biochemical groups essentially involved in the sorption phenomenon was made possible by FTIR spectral analysis. The capacity of ZLSP as an effective and ecofriendly biosorbent is confirmed through this study.

• Analytical Science and Technology
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• v.26 no.6
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• pp.353-356
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• 2013

A method on the determination of caffeine in beverage with acridiene orange-${\beta}$-cyclodextrin (CD) inclusion complex was developed. The conditions such as pH of the sample solution and concentration of acridine orange and ${\beta}$-CD were optimized to 12.0(${\pm}0.5$), $1.9{\times}10^{-6}M$ and $1.25{\times}10^{-3}M$, respectively. Under these optimum conditions, the calibration curve of caffeine was obtained over concentration range of $5{\times}10^{-5}{\sim}1.1{\times}10^{-3}M$. The detection limit was $1.0{\times}10^{-5}M$. The relative errors(%) in beverage samples were less than 5.0%.

• Journal of Environmental Science International
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• v.15 no.12
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• pp.1171-1175
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• 2006

Deposited road particles (DRPs) were analysed for heavy metal concentrations at four different roads in a city, Korea. The samples were collected using a roadway surface vacuum cleaning vehicle which was commonly used in collecting roadway surface particles. Six particle size ranges were analyzed separately for twelve heavy metal elements (Cd, Cr, Pb, Ni, Al, As, Co, Cu, Fe, Mn, Zn and Hg). At all sampling sites, the high concentration of the heavy metals occurred in the <74um particle size range, which conventional roadway cleaning vehicles do not remove efficiently. The Pb concentration significantly increased with decreasing particle size of DRPs, and other toxic heavy metals (Cd, Cr and Ni) also showed similar results. The heavy metal concentrations in the smaller size fraction of DRPs is important because they are contaminants that are preferentially transported by road runoff during rainfall.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.22-32
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• 1989

In order to assess the level of atmospheric pollution and to contribute the health improve ment of residents in Pusan, the authors measured the $CO, SO_2, NO_2, TSP, Noise, Pb, Cd, Cr and V$ level at 3 place by time from Jan. 1988 to Feb. 1988. THe places were Kukje, Daehyeon, Pujeon underground commercial floor. The results were as follows; 1. The range of concentration of air pollutants (1) CO : 0.5 - 3.0 ppm (2) $SO_2$ : 0.012 - 0.360 ppm (3) $NO_2$ : 0.018 - 0.089 ppm (4) TSP : 30 - 330 $\mug/m^3$ (5) Pb : 0.219 - 3.116 $\mug/m^3$ (6) Cd : 0.000 - 0.070 $\mug/m^3$ (7) Cr : 0.378 - 4.098 $\mug/m^3$ (8) V : 0.000 - 1.010 $\mug/m^3$ (9) Noise : 47 - 77 dB(A) 2. The level of all air pollutants were higher in the afternoon or night than in the morning. 3. The mean concentration of $SO_2$ in all places exceede the ambient air quality standard of $SO_2$,.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1433-1436
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• 2007

Using a blue emitting DPVBi material and red dopant DCJTB, WOLEDs with and without green emitter C6 added in ETL or HTL have been fabricated. The chromaticity color index of WOLEDs without C6 depends strongly on the doping concentration. In addition, manipulating thickness of emitting layer is similar effect such as controlling weight concentration of dopant. While the white color of WOLEDs with C6 added in ETL or HTL depend on position of C6. WOLED of three colors added green dye have been shown turn-on voltage of 3.25V, and EL efficiency 3.05cd/A @9V, $8102\;cd/m^2$, CIE coordinates (0.30, 0.32).

• 한국해양학회지
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• v.15 no.1
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• pp.66-70
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• 1980

A method for the determination of dissolved species of Cd, Co, Cu, Ni, Pb and Zn in sea water by flame atomic absorption spectrophotometry (AAS) is described. Prior to analysis by AAS, these elements are concentrated by coprecipitation with iron pyrrolidinedithiocarbamate at pH 3 because of matrix effects and their low concentration levels in sea water. The detection limits are 0.01, 0.04, 0.02, 0.05, 0.08, and 0.03$\mu\textrm{g}$/l, and the relative standard deviations are 1.0, 2.4, 1.3, 2.9, 2.0 and 2.9% for Cd, Co, Cu, Ni, Pb and Zn, respectively. The method is shown to be satisfactory in terms of recovery and precision for the determination of these metals in sea water.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.363-369
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• 1999

The heavy metal removability of four kinds of tea was investigated in the various conditions: particle size of tea(10, 35. 70, 100 mesh), concentration of heavy metal(25, 50, 100ppm) and extraction temperature(30. 50, 70. 10$0^{\circ}C$). The removabilities by the tea solids were increased as the particle size decreased, concentration of heavy metal increased, and extracting temperature increased. Of the four kinds of tea Pb, Cd and Cu removability by Eucommia ulmoides Oliv tea was the highest. In addition, heavy metal removability by Schizandra chinensis Baillon tea was better than that of other tea as extraction temperature was increased.

• Advances in nano research
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• v.1 no.3
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• pp.153-158
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• 2013

An approach to achieving of spatially homogeneous, ordered ensemble of semiconductor quantum rods in polymer film of polyvinyl butyral is reported. The CdSe/ZnS quantum rods are embedded to the polymer film. Obtained film is stretched up to four times to its initial length. A concentration of quantum rods in the samples is around $2{\times}10^{-5}$ M. The absorption spectra, obtained in the light with orthogonal polarization, confirm the occurrence of spatial ordering in a quantum rod ensemble. Anisotropy of the optical properties in the ordered quantum rod ensemble is examined. The presented method can be used as a low-cost solution for preparing the nanostructured materials with anisotropic properties and high concentration of nanocrystals.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.589-597
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• 2016

There are a number of industrial complexes which could be a source of heavy metal (loid)s contamination of arable soil in Gyeongnam province of South Korea. Heavy metal (loid)s accumulation of plant is more related to the concentration of plant available heavy metal (loid)s in arable soil than that of total heavy metal (loid)s. The objectives of this study were 1) to examine heavy metal concentrations in soils located near industrial complexes in Gyeongnam province and 2) to determine the relationship between concentration of plant available heavy metal (loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 7 industrial complexes in Gyeongnam province. Total heavy metal (loid)s concentration, available heavy metal (loid)s concentration, and chemical properties of collected soils were measured. The mean concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the soils were $5.8mg\;kg^{-1}$, $1.3mg\;kg^{-1}$, $0.03mg\;kg^{-1}$, $51.5mg\;kg^{-1}$, and $68.7mg\;kg^{-1}$, respectively. Total concentration of Cd and Zn in arable soil located near ${\nabla}{\nabla}$ industrial complex exceeded the warning criteria ($4mg\;kg^{-1}$ and $300mg\;kg^{-1}$ for Cd and Zn, respectively) as described by in the soil environmental conservation Act of Korea. The concentration of plant available heavy metal (loid)s was negatively related to the soil pH and available Pb and Zn concentrations had relatively high correlation coefficient when compared with other heavy metal (loid)s. The concentration of plant available Pb and Zn was negatively related to that of organic matter (OM). Based on the above results, it might be a good soil management to control pH and OM concentration with soil amendments such as lime and compost to reduce phytoavailability of heavy metal (loid)s in arable soil located near industrial complex.