• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.30-36
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• 2001

The crystal structures of fully dehydrated $Pd^{2+}$ - and $TI^{+}$ -exchanged zeolite X, $Pd_{18}TI_{56}Si_{100}Al_{92}O_{384}(Pd_{18}TI_{50-}X$, a = $24.935(4)\AA$ and $Pd_{21}TI_{50}Si_{100}Al_{92}O_{384}(Pd_{21}TI_{50-}X$ a = $24.914(4)\AA)$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd3 at $21(1)^{\circ}C.$ The crystals were prepared using an exchange solution that had a $Pd(NH_3)_4Cl_2\;:TINO_3$ mole ratio of 50 : 1 and 200 : 1, respectively, with a total concentration of 0.05M for 4 days. After dehydration at $360^{\circ}C$ and 2 ${\times}$$10^{-6}$ Torr in flowing oxygen for 2 days, the crystals were evacuated at $21(1)^{\circ}C$ for 2 hours. They were refined to the final error indices $R_1$ = 0.045 and $R_2$ = 0.038 with 344 reflections for $Pd_{18}Tl_{56-}X$, and $R_1$ = 0.043 and $R_2$ = 0.045 with 280 reflections for $Pd_{21}Tl_{50-}X$; I > $3\sigma(I).$ In the structure of dehydrated $Pd_{18}Tl_{56-}X$, eighteen $Pd^{2+}$ ions and fourteen $TI^{+}$ ions are located at site I'. About twenty-seven $TI^{+}$ ions occupy site II recessed $1.74\AA$ into a supercage from the plane of three oxygens. The remaining fifteen $TI^{+}$ ions are distributed over two non-equivalent III' sites, with occupancies of 11 and 4, respectively. In the structure of $Pd_{21}Tl_{50-}X$, twenty $Pd^{2+}$ and ten $TI^{+}$ ions occupy site I', and one $Pd^{2+}$ ion is at site I. About twenty-three $TI^{+}$ ions occupy site II, and the remaining seventeen $TI^{+}$ ions are distributed over two different III' sites. $Pd^{2+}$ ions show a limit of exchange (ca. 39% and 46%), though their concentration of exchange was much higher than that of $TI^{+}$ ions. $Pd^{2+}$ ions tend to occupy site I', where they fit the double six-ring plane as nearly ideal trigonal planar. $TI^{+}$ ions fill the remaining I' sites, then occupy site II and two different III' sites. The two crystal structures show that approximately two and one-half I' sites per sodalite cage may be occupied by $Pd^{2+}$ ions. The remaining I' sites are occupied by $TI^{+}$ ions with Tl-O bond distance that is shorter than the sum of their ionic radii. The electrostatic repulsion between two large $TI^{+}$ ions and between $TI^{+}$ and $Pd^{2+}$ ions in the same $\beta-cage$ pushes each other to the charged six-ring planes. It causes the Tl-O bond to have some covalent character. However, $TI^{+}$ ions at site II form ionic bonds with three oxygens because the super-cage has the available space to obtain the reliable ionic bonds.

• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.64-71
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• 2019

Background: It is very difficult to distinguish between a radioactive contamination source and background radiation from natural radionuclides in the marine environment by means of online monitoring system. The objective of this study was to investigate a statistical process for triggering abnormal level of count rate data measured from our on-line seawater radioactivity monitoring. Materials and Methods: Count rate data sets in time series were collected from 9 monitoring posts. All of the count rate data were measured every 15 minutes from the region of interest (ROI) for $^{137}Cs$ ($E_{\gamma}=661.6keV$) on the gamma-ray energy spectrum. The Shewhart ($3{\sigma}$), CUSUM, and Bayesian S-R control chart methods were evaluated and the comparative analysis of determination methods for count rate data was carried out in terms of the false positive incidence rate. All statistical algorithms were developed using R Programming by the authors. Results and Discussion: The $3{\sigma}$, CUSUM, and S-R analyses resulted in the average false positive incidence rate of $0.164{\pm}0.047%$, $0.064{\pm}0.0367%$, and $0.030{\pm}0.018%$, respectively. The S-R method has a lower value than that of the $3{\sigma}$ and CUSUM method, because the Bayesian S-R method use the information to evaluate a posterior distribution, even though the CUSUM control chart accumulate information from recent data points. As the result of comparison between net count rate and gross count rate measured in time series all the year at a monitoring post using the $3{\sigma}$ control charts, the two methods resulted in the false positive incidence rate of 0.142% and 0.219%, respectively. Conclusion: Bayesian S-R and CUSUM control charts are better suited for on-line seawater radioactivity monitoring with an count rate data in time series than $3{\sigma}$ control chart. However, it requires a continuous increasing trend to differentiate between a false positive and actual radioactive contamination. For the determination of count rate, the net count method is better than the gross count method because of relatively a small variation in the data points.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.776-783
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• 2021

Objective : The purpose of this study was to identify risk factors for distal adding on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF) to L3 with a minimum 2-year follow-up. Methods : AIS patients undergoing PSF to L3 by two senior surgeons from 2000-2010 were analyzed. Distal AO and DJK were deemed poor radiographic results and defined as >3 cm of deviation from L3 to the center sacral vertical line (CSVL), or >10° angle at L3-4 on the posterior anterior- or lateral X-ray at ultimate follow-up. New stable vertebra (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores. Results : Ten of 76 patients (13.1%) were included in the poor radiographic outcome group. The other 66 patients were included in the good radiographic outcome group. Lower Risser grade, more SV-3 (CSVL doesn't touch the lowest instrumented vertebra [LIV]) on standing and side bending films, lesser NV and TS score, rigid L3-4 disc, more rotation and deviation of L3 were identified risk factors for AO or DJK. Age, number of fused vertebrae, curve correction, preoperative coronal/sagittal L3-4 disc angle did not differ significantly between the two groups. Multiple logistic regression results indicated that preoperative Risser grade 0, 1 (odds ratio [OR], 1.8), SV-3 at L3 in standing and side benders (OR, 2.1 and 2.8, respectively), TS score -5, -6 at L3 (OR, 4.4), rigid disc at L3-4 (OR, 3.1), LIV rotation >15° (OR, 2.9), and LIV deviation >2 cm from CSVL (OR, 2.2) were independent predictive factors. Although there was significant improvement of the of Scoliosis Research Society-22 average scores only in the good radiographic outcome group, there was no significant difference in the scores between the groups. Conclusion : The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was 13.1%. To prevent AO or DJK following fusion to L3, we recommend that the CSVL touch L3 in both standing and side bending, TS score is -4 or less, the L3/4 disc is flexible, L3 is neutral (<15°) and ≤2 cm from the midline and the patient is ≥ Risser 2.

• Journal of Conservation Science
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• v.38 no.2
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• pp.133-143
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• 2022

In this study, we analyzed the rickshaw (Owned by the Daegu Modern History Museum) by measuring each material. The purpose of the study was to identify the materials in modern cultural assets that utilize a variety of materials in a complex way, and establish basic data for preservation and management. Using portable X-ray fluorescence analyzers (P-XRF), species identification, fiber identification, paint film analysis (microscope observation, SEM-EDS, FTIR) on metal, wood, fiber and paint was carried out. Brass, an alloy of Copper, Zinc and Iron, was measured in the metal parts. Further, wooden parts, such as Oak (Quercus acutissima), Japanese Cedar (Cryptomeria japonica), Bamboo (Bambusoideae). Torreya nucifera (Torreya spp.) were identified in the body. Fiber parts consisted mainly of cotton, but some parts were also made of leather. In terms of paint, rickshaws were applied with multiple layers, using cashew (synthetic paint used in place of lacquer). In sum, the rickshaw body part appeared to overlap with layers of fiber, metal (soild), paint, and colored (black, red) layer.

• Journal of agricultural medicine and community health
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• v.27 no.2
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• pp.107-126
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• 2002

Health sub-centers(HSCs) have played an important role in primary health care in rural area in Korea. The unification of neighboring HSCs was a strategy to improve the role of HSCs. This study was conducted to reveal the efficacy of the unified HSC established in Yangbuk-myeon, Gyeongju-si in1997. The utilization patterns of HSC and its related factors, and satisfaction of consumer on HSC were compared before and after unification of two HSCs in Gampo-eup, Yangnam-myeon using questionnaire survey, and also the statistics of medical care services and public health services were compared. Four hundred forty nine subjects were questioned in survey, 156 from Gampo-eup, 147 from Yangbuk-myeon, and 146 from Yangnam-myeon. Following unification, the utilization rates and the frequency of visits in Gampo-eup declined. In all three areas, chronic illness was the common factor influencing the utilization and change in frequency of visits to the unified HSC. Following unification, aspects of consumer satisfaction, for example; accessibility and affordability decreased in Gampo-eup, but increased in both Yangbuk-myeon and Yangnam-myeon. The statistics relating to medical care, X-ray examination, home visiting service, vaccination, and health education showed an increase for the unified HSC when compared to the sum of the statistics for the previous two. The execution rates for other public health services were the same, or a little decreased. Clinical laboratory examinations and the issuing of civil affair documents were new services offered by the unified HSC. It is concluded, the overall consumer satisfaction with the unified HSC was improved. In Gampo-eup, where after unification there was no HSC, it seemed to be a barrier to accessing the unified HSC. The effect of the unified HSC, in the respect of medical care and public health services, was not as significant as expected at the time of being established. Therefore, the strategies to reenforce the unified HSC should be developed to provide all residents with comprehensive primary health care services.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.281-295
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• 2010

This paper deals with magnetic susceptibility, mineralogy, soil properties (pH, EC, CEC, loss on ignition), iron and manganese oxides, the content and partitioning of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn), and their mutual relationship in the soil samples of an unpolluted, abandoned mine area, and industrial complex area. The various minerals derived from weathered bedrock were identified by X-ray diffraction in the unpolluted soil samples, except for the magnetic minerals. XRD analysis also revealed the existence of hematite and magnetite related to mine tailings and waste rocks in the abandoned mine area samples. The industrial complex area samples had carbonate minerals, such as calcite and dolomite, that might be due to anthropogenic deposition. The sum of the reducible, oxidizable, and residual fractions was over 80% for the abandoned mine area samples and over 50% for the industrial complex area samples using the sequential extraction method. The industrial complex area samples had a relatively high carbonate fraction that was associated with carbonate minerals. The content of aqua regia-extractable Fe, Mn, As, and Zn had a high positive correlation with the content of the dithionite-citrate-bicarbonate (DCB)-extractable method related to Fe/Mn oxide phases. The 54% and 58% of aqua regia-extractable Fe and As content, respectively, acted together with the concentrations of the DCB-extractable phases. Magnetic susceptibility values of total samples ranged from 0.005 to $2.131{\times}10^{-6}m^3kg^{-1}$. The samples including iron oxide minerals, such as hematite and magnetite, had a high magnetic susceptibility. The magnetic susceptibility showed a significant correlation with the heavy metals, Cd (r=0.544, p<0.05), Cr (r=0.714, p<0.01), Ni (r=0.645, p<0.05), Pb (r=0.703, p<0.01), and Zn (r=0.496, p<0.01), as well as Fe (r=0.608, p<0.01) and Mn (r=0.615, p<0.01). The aqua regia-extractable Fe and Mn content had a significant positive correlation with Cd, Cr, Cu, Ni, and Zn. However, the DCB-extractable Fe and Mn content had a significant positive correlation with As and Ni, indicating that the heavy metals were associated with Fe and Mn oxide minerals.

• 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.