• Journal of Radiation Protection and Research
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• v.24 no.1
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• pp.1-7
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• 1999

Using the TBP slovent extraction method, a simple and precise method for determining uranium isotopes in the environment samples was developed. The soil sample was decomposed with $HNO_3$ and HF. Uranium isotopes were extracted with 15% TBP in $CCl_4$ from aqueous phase to organic phase, and Th fraction was removed with 8M HCl. Uranium fraction was purified in back extraction step with 1M HCl. Optimized electrode position conditions of uranium Isotopes were set using a new electrode position solution including a DTPA chelating agent. The new method of uranium isotopes determination was validated with a result of application to IAEA Reference Soils.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.4
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• pp.221-228
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• 1992

In order to evaluate the degree of air pollution, soils from 125 and 60points of main streets of Seoul and Daejeon, respectively, were sampled and analyzed for the contents of lead, copper, iron and zinc by nitric acid($HNO_3$) extraction followed by atomic absorption spectrophotometry during June and September, 1990. The Pb contents of Seoul and Daejeon were 350.2$\mu$g/g and 175.9$\mu$g/g, respectively, which were 14.5times and 7.3times respectively higher than the control(24.0). In Seoul, the commercial area gave the highest value followed by resdential and industrial areas in the decreasing order, while the order in Daejeon was Industrial, commercial and residential areas. The Cu contents in Seoul and Daejeon were very similar(236.6 and 234.6, respectively) each other, and about 11times higher than the control(20.9). The concentration was highest in industrial, followed by commercial and the lowest in residential areas in Seoul, while the order in Daejeon was industrial, residential and commercial areas. The Fe contents were 25716.5 in Seoul and 22838.6 in Daejeon, both being similar to the control value(22537.0). The value was highest in industrial and next in commercial areas and the lowest in residential area both in Seoul and Daejeon. The Zn contents in Seoul and Daejeon were 728.2 and 404.0, respectively, wihch were 6.3 and 3.6times higher than the control(113.3). The value was highest in commercial and next in industrial areas and the lowest in residental area in Seoul, while the order was industrial, residential and commercial areas in Daejeon. The heavy metal content was higher in the soil of main streets than that of minor streets in Seoul. The content of lead in Seoul was higher in the streets of Chongro-ku(525.9) and Chung-ku(684.8), the central area of the city which had a heavy traffic, than those in Nowon-ku(320.3) and Kwanak-ku(312.6) which had relatively less traffic crowd. The similar pattern was observed in the content of zinc; it was higher in Chongro-ku(1305.0) and Chung-ku(1335.4) than in Nowon-ku(489.1) and Kwanak-ku(569.8). In Daejeon, the contents of lead and zinc were decreasing as the distance from Daejeon Railroad Station increased : they were respectively 157.8 and 447.7 within 2km from the station, 157.6 and 235.7 with in 2-4km, and 63.5 and 156.2 within 4-6km and 58.7 and 142.2 within 6-8km. In summary, the contents of lead, copper and zinc were generally higher in the central area of the city, areas of heavy traffic and areas of industry and commerce.

• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.1
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• pp.46-61
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• 1985

This study was performed to obtain the basic data which can be applied to the use of foaming mortars. The data was based on the properties of foaming mortars depending upon various mixing ratios and addings to compare those of cement mortar. The foaming agents which was used at this experiment were pre-foamed type and mix-foaming type which is being used as mortar structures. The foaming mortar, mixing ratios of cement to fine aggregate were 1:1, 1: 2, 1 : 3 and 1 : 4. The addings of foaming agents were 0.0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% of cement weight. The results obtained were summarized as follows; 1. At the mixing ratio of 1 : 1, the lowest water-cement ratios were showed by foaming mortars, respectively. But it gradually was increased in poorer mixing ratio and decreased in more addition of foaming agent. The water-cement ratios were decreased up to 1. 8~22. 0% by G, 2. 2~24. 1 % by U and 0. 7~53. 1% by J foaming mortar than cement mortar. 2, At the mixing ratio of 1 : 1, the highest bulk densities were showed by foaming mortars, respectively. But, it gradually was decreased in poorer mixing ratio and more addition of foaming agent. The bulk densities were decreased up to 1. 4~20. 7% by G, 2. 3~23. 7% by U and 26. 5~56. 5% by J foaming mortar than cement mortar. Therefore, foaming mortar could be utilized to the constructions which need low strengths. 3. At the mixing ratio of 1:1, the lowest absorption rates were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Specially, according to the absorption rate when immersed in 72 hours, the absorption rates were showed up to 1. 01~1. 24 times by G, 1. 03~1. 58 times by U and 1. 10~5. 91 times by J foaming mortar than cement mortar. It was significantly higher at the early stage of immersed time than cement mortar. 4. At the mixing ratio of 1:1, the lowest air contents were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Air contents were contented up to 4. 0~17. 2 times by G, 5. 2~23. 2 times by U and 23. 8~74. 5 times by J foaming mortar than cement mortar. 5. At the mixing ratio of 1 : 1, the lowest decreasing rates of strengths were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Specially, the strengths of 28 days were decreased 0. 4~2. 2% than those of 7 days by foaming mortar, respectively. Also, the correlations between compressive and tensile strength, compressive and ending strength, tensile and bending strength were highly significant as a straight line shaped, respectively. 6. The correlations between absorption rate, air content, compressive strength and bulk density, absorption rate, compressive strength and air content were highly significant, respectively. The multiple regression equations of water-cement ratio, bulk density, absorption ate, air content, compressive strength, tensile strength and bending strength were computed depending on a function of mixing ratio and addition of foaming agent. It was highly significant, respectively. 7. At the mixing ratio of 1 : 1, the highest strengths were showed by cement mortar and foaming mortars, by chemical reagents. But, it gradually was decreased in poorer mixing ratio. The decreasing rates of strengths were in order of H $_2$S0 $_4$, HNO$_3$ and HCI, J,U,G foaming mortar and cement mortar. Specially, at the each mixing ratio, each chemical reagent and 3.0% of foaming agent, J foaming mortar was collapsed obviously. Therefore, for the structures requiring acid resistence, adding of foaming agent should be lower than 3.0%.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.195-206
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• 2009

We investigated natural background and enrichment characteristics and predicted geochemical disaster for stream sediments in the Hamyang-Sancheong area. Stream sediments samples were collected 95 ea in study area. The stream sediments were well known that had not possibility of contamination effect and represented drainage basins. We got the major and hazardous elements concentrations by XRF, ICP-AES and NAA analysis methods. Acid decomposition for the ICP-AES has been used $HClO_4$ and HF with $200^{\circ}C$ heating at 1st and after that $HClO_4$ HF and HCl with $200^{\circ}C$ heating at 2nd stage. We could know the characteristics that concentration of Cu and Co decreased when concentration of $SiO_2$ increased in correlation analysis. The enrichment factor of the stream sediments was below 2 in study area. This result indicated that study area belonged to moderate enrichment. The stream sediments of Hamyang area were enriched in order of Pb>Th>Cr>V>Co>Cu and those of Sancheong area were enriched in order of Pb>Th>Cr>Co>V>Cu. The enrichment factor(E.F.) of the Pb, Cr, Co and V was similar between Hamyang and Sancheong area. The enrichment factor of the Th was higher in Hamyang area and that of the Cu was higher in Sancheong area. The enrichment factor of the Pb was highly enriched in all study area than earth crust mean. But we could know that study area was not exposed to the pollution of the Pb through the tolerable level.

• Applied Biological Chemistry
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• v.10
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• pp.1-13
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• 1968

Phytin is a salt(mainly calcium and magnesium) of phytic acid and its purity and molecular formula can be determined by assaying the contents of phosporus, calcium and magnesium in phytin. In order to devise a new method for the quantitative analysis of the three elements in phytin, the chelatometric method was developed as follows: 1) As the pretreatment for phytin analysis, it was ashfied st $550{\sim}600^{\circ}C$ in the presence of concentrated nitric acid. This dry process is more accurate than the wet process. 2) Phosphorus, calcium and megnesium were analyzed by the conventional and the new method described here, for the phytin sample decomposed by the dry process. The ashfied phytin solution in hydrochloric acid was partitioned into cation and anion fractions by means of a ration exchange resin. A portion of the ration fraction was adjusted to pH 7.0, followed by readjustment to pH 10 and titrated with standard EDTA solution using the BT [Eriochrome black T] indicator to obtain the combined value of calcium and magnesium. Another portion of the ration fraction was made to pH 7.0, and a small volume of standard EDTA solution was added to it. pH was adjusted to $12{\sim}13$ with 8 N KOH and it was titrate by a standard EDTA solution in the presence of N-N[2-Hydroxy-1-(2-hydroxy-4-sulfo-1-naphytate)-3-naphthoic acid] diluted powder indicator in order to obtain the calcium content. Magnesium content was calculated from the difference between the two values. From the anion fraction the magnesium ammonium phosphate precipitate was obtained. The precipitate was dissolved in hydrochloric acid, and a standard EDTA solution was added to it. The solution was adjusted to pH 7.0 and then readjusted to pH 10.0 by a buffer solution and titrated with a standard magnesium sulfate solution in the presence of BT indicator to obtain the phosphorus content. The analytical data for phosphorus, calcium and magnesium were 98.9%, 97.1% and 99.1% respectively, in reference to the theoretical values for the formula $C_6H_6O_{24}P_6Mg_4CaNa_2{\cdot}5H_2O$. Statical analysis indicated a good coincidence of the theoretical and experimental values. On the other hand, the observed values for the three elements by the conventional method were 92.4%, 86.8% and 93.8%, respectively, revealing a remarkable difference from the theoretical. 3) When sodium phytate was admixed with starch and subjected to the analysis of phosphorus, calcium and magnesium by the chelatometric method, their recovery was almost 100% 4) In order to confirm the accuracy of this method, phytic acid was reacted with calcium chloride and magnesium chloride in the molar ratio of phytic: calcium chloride: magnesium chloride=1 : 5 : 20 to obtain sodium phytate containing one calcium atom and four magnesium atoms per molecule of sodium phytate. The analytical data for phosporus, calcium and magnesium were coincident with those as determine d by the aforementioned method. The new method employing the dry process, ion exchange resin and chelatometric assay of phosphorus, calcium and magnesium is considered accurate and rapid for the determination of phytin.

• Economic and Environmental Geology
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• v.8 no.3
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• pp.117-124
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• 1975

Wet chemical analysis (for $MnO_2$, MnO, and $H_2O$(+)) and electron microprobe analysis (for $Fe_2O_3$ and PbO) give $MnO_2$ 74.91, MnO 11.33, $Fe_2O_3$ (total Fe) 4.19, PbO 0.03, $H_2O$ (+) 9.46, sum 99.92%. 'Available oxygen determined by oxalate titration method is allotted to $MnO_2$ from total Mn, and the remaining Mn is calculated as MnO. Traces of Ba, Ca, Mg, K, Cu, Zn, and Al were found. Li and Na were not found. The existence of (OH) is verified from the infrared absorption spectra. The analysis corresponds to the formula $Mn^{4+}{_{4.85}}(Mn^{2+}{_{0.90}}Fe^{3+}{_{0.30}})_{1.20}O_{8.09}(OH)_{5.91}$, on the basis of O=14, 'or ideally $Mn^{4+}{_{5-x}}(Mn^{2+},Fe^{3+})_{1+x}O_{8}(OH)_{6}$ ($x{\approx}0.2$). X-ray single crystal study could not be made because of the distortion of single crystals. But the x-ray powder pattern is satisfactorily indexed by an orthorhombic cell with a 9.324, b 14.05, c $7.956{\AA}$., Z=4. The indexed powder diffraction lines are 9.34(s) (100), 7.09(s) (020), 4.62(m) (200, 121), 4.17(m) (130), 3.547(s) (112), 3.212(vw) (041), 3.101(s) (300), 2.597(w) (013), 2.469(m) (331), 2.214(vw)(420), 2.098(vw) (260), 2.014 (vw) (402), 1.863(w) (500), 1.664(w) (314), 1.554(vw) (600), 1.525(m) (601), 1.405(m) (0.10.0). DTA curve shows the endothermic peaks at $250-370^{\circ}C$ and $955^{\circ}C$. The former is due to the dehydration: and oxidation forming$(Mn,\;Fe)_2O_3$(cubic, a $9.417{\AA}$), and the latter is interpreted as the formation of a hausmannite-type oxide (tetragonal, a 5.76, c $9.51{\AA}$) from $(Mn,\;Fe)_2O_3$. Infrared absorption spectral curve shows Mn-O stretching vibrations at $515cm^{-1}$ and $545cm^{-1}$, O-H bending vibration at $1025cm^{-1}$ and O-H stretching vibration at $3225cm^{-1}$. Opaque. Reflectance 13-15%. Bireflectance distinct in air and strong in oil. Reflection pleochroism changes from whitish to light grey. Between crossed nicols, color changes from yellowish brown with bluish tint to grey in air and yellowish brown to grey through bluish brown in oil. No internal reflections. Etching reactions: HCl(conc.) and $H_2SO_4+H_2O_2$-grey tarnish; $SnCl_2$(sat.)-dark color; $HNO_3$(conc.)-grey color; $H_2O_2$-tarnish with effervescence. It is black in color. Luster dull. Cleavage one direction perfect. Streak brownish black to dark brown. H. (Mohs) 2-3, very fragile. Specific gravity 3.59(obs.), 3.57(calc.). It occurs as radiating groups of flakes, flower-like aggregates, colloform bands, dendritic or arborescent masses composed of fine grains in the cementation zone of the supergene manganese oxide deposits of the Janggun mine, Bonghwa-gun, southeastern Korea. Associated minerals are calcite, nsutite, todorokite, and some undetermined manganese dioxide minerals. The name is for the mine, the first locality. The mineral and name were approved before publication by the Commission on New Minerals and Mineral Names, I.M.A.