• Journal of the Korean Vacuum Society
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• v.6 no.1
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• pp.36-43
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• 1997

FECAPS(ferroelectric capacitors) have been fabricated by RF magnetron sputtering deposition of 3000$\AA$ PZT thin films on the Pt/Ti/$SiO_2$/Si substrates and post-annealing with the temperature of $550^{\circ}C$~$650^{\circ}C$ for 10 sec~50 sec in a RTA system. The electrical characteristics of the fabricated capacitors showed the highest dielectric constant and remanent polarization[${\varepsilon_r(1kHz)$=690, $2P_r$(-5V~5V sweep)=22$\mu$C/$ \textrm{cm}^2$] in the samples annealed at $650^{\circ}C$ for 30 sec, while the lowest tangent loss and leakage current [$tan\delta(\ge10kHz)\le0.02, \; J_i(5V)=3\mu\textrm{A}/\textrm{cm}^2$]in the samples annealed at $600^{\circ}C$ for 30 sec.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.1-12
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• 2007

This study was investigated hazardous substances in agricultural products of baggage by Incheon Port from chinese. We tested 293 kinds of dried red pepper, cereal, sesame, bean, nut, herbal medicine and sesame oil for pesticides residue, mold, tar color, sudan I, II, III, IV, aflatoxin, Pb, Cd, Hg, As and sulfur dioxide residues. Violated samples over standard limits by Korean Food and Drug Administration (KFDA) were 76 dried red pepper over the number of mold and 1 dried red pepper detected red 102 tar color and 1 dried red pepper over the number of mold and detected red 102 tar color simultaneously. And 2 rice, 1 sticky rice, 1 adlay and 1 millet were over lead. Violated herbal medicine were 2 Zizyphi Furctus and 2 Zingiberis Rhizoma over sulfur dioxide residue and 1 Zingiberis Rhizoma over sulfur dioxide residue and cadmium simultaneously. The contents of heavy metals in cereal were as follow; $Pb\;0.000{\sim}0.740mg/kg(0.191{\pm}0.209),\;Cd\;0.000{\sim}0.108mg/kg(0.007{\pm}0.020),\;Hg\;0.000{\sim}4.201mg/kg(0.162{\pm}0.319)$. The contents of heavy metals in herbal medicine were as follow; $Pb\;0.000{\sim}2.480mg/kg(1.130{\pm}0.730),\;Cd\;0.000{\sim}0.761mg/kg(0.044{\pm}0.122),\;Hg\;0.000{\sim}0.157mg/kg(0.022{\pm}0.033),\;As\;0.000{\sim}0.560mg/kg(0.040{\pm}0.082)$. Contents of $SO_2$ ranged $2.0{\sim}1459.4ppm(303.1{\pm}324.2)$.

• Polymer(Korea)
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• v.31 no.2
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• pp.93-97
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• 2007

Phenyl styryl ketone ligands 1-5 containing different functional groups were synthesized and attached to the aminated poly (styrene-divinvlbenzene) copolymer through diazotization. The coupling of the ligand with polymer was confirmed by FT-IR. The variation of the uptakes of Pb (II) or Cu (II) ions loaded in the prepared polymers (6-10) was examined at different pH values. An increase of metal uptake in the polymers was observed with the increase in pH value in aqueous solution.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.217-235
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• 2012

We evaluated the geochemical characteristics and their potential pollution of Asian Dusts in Daejeon, Korea during spring 2007. Compared with the chemical compositions of soils in source area of Asian Dust, those of aerosols in Daejeon were enriched with trace elements (ten to hundred fold), inferring that pollutants from China have affected on local environment in adjoining country such as Korea. Chemical analysis of aerosols during Asian dust showed that fine particles ($PM_{2.5}$) contained high contents of trace elements such as Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc and Y. In the case of TSP (Total Suspended Particle), Zr, Sr, Ba, Li, Th and U were contained much more than other trace elements. The contents of some elements (i.e. Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr and Sc) in aerosols collected in Asian Dust period, which are not likely enriched by air pollutants, were higher (2 - 4.2 fold) than those in Non Asian Dust period, indicating that these elements could be used as indicator elements for determining the occurrence of Asian Dust phenomena (especially, Sr, V, Cr & Li). In the case of Asian Dust coming through the big cities and/or industrial areas of China, the domestic aerosols had higher contents of trace elements (such as S, Cd, Zn, Pb, Cu, Mo and As) than those from Northeastern China via North Korea, indicating that the transportation courses of air mass are very important to determine the pollution degrees. Using the enrichment factors of trace elements in aerosols during Asian Dust and Non Asian Dust, we identified that some elements (i.e. S, Zn, Cu, Pb, As, Mo and Cd) were most problematic in terms of environmental hazard aspects, and these elements could affect adverse effects on human health as well as ecosystem and surface environment (soil and water) through long-lived precipitation.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.85-90
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• 2017

The $TiCl_4$ as a blocking material is adsorbed in the mesoporous $TiO_2$ electron transfer layer(ETL) of the Perovskite solar cell to prevent the direct contact between the FTO electrode and the photoactive layer(AL), and facilitate the movement of the electrons between $TiO_2:TiCl_4$ ETL and Perovskite AL to improve the photoelectric conversion efficiency(PCE). The structure of the perovskite solar cell is FTO/$TiO_2:TiCl_4$/Perovskite($CH_3NH_3PbI_3$)/spiro-OMeTAD/Ag. It was investigated that the dipping time of the $TiO_2$ into $TiCl_4$ aqueous solution affects on the photoelectric characteristics of the device. By the dipping for 30 minutes, the PCE of the perovskite solar cell with the $TiO_2:TiCl_4$ ETL was the highest 10.46%, which is 27% higher than the cell with $TiO_2$ ETL. From SEM, EDS, and XRD characterization on the $TiO_2:TiCl_4$ ETL and the perovskite AL, it was measured that the decrease of the porosity of the $TiO_2$ layer, the detection of the Cl component by the $TiCl_4$ adsorption, the cube-type morphology of perovskite AL, and shift of the $PbI_2$ peak of the perovskite AL. From these results, it was confirmed that the $TiO_2:TiCl_4$ ETL and the perovskite AL were formed.

• Journal of Society of Preventive Korean Medicine
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• v.6 no.2
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• pp.66-85
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• 2002

Traditional herbal medicine is used extensively among the Korean populations, and other Asian countries employ similar therapies as well In recent years, extensive focus was laid on adulteration of the herbal medicine with heavy metals. This may be mainly due to a soil contamination by an environmental pollution. The objective of this study is to identify the contents of various heavy metals in the blood from OhJeokSan-Decoction (OD) treated-rats. For this study, 13 kinds of metals including essential and heavy metals, i.e. Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were analyzed by a slight modification of EPA methods and the following results are obtained. ; 1. There is no significant difference between the OD-treated groups and control group in liver, kidney, bone, brain, weight, food intake. 2. The amount of each metal analyzed in the liver are as follows; Al ; $0.235{\sim}4.215mg／kg$, As ; $0.103{\sim}0.461mg／kg$, Cd ; $0.005{\sim}0.010mg／kg$, Co ; $0.017{\sim}0.046mg／kg$, Cr ; $0.137{\sim}0.403mg／kg$, Cu ; $1.736{\sim}4.827mg／kg$, Fe ; $54.472{\sim}381.447mg／kg$, Hg ; not detected, Mn ; $1.159{\sim}2.803mg／kg$, Ni ; $0.007{\sim}0.095mg／kg$, Pb ; not detected, Se ; $0.682{\sim}1.887mg／kg$, Zn ; $10.213{\sim}26.119mg／kg$, by groups, respectively. In control and other experimental group, several metal (Co, Cu, Mn, Zn, As, Cr) has a significant difference, but in experimental I and other experimental II, III, IV, V groups, there are no significant difference. 3. The amount of each metal analyzed in the kidney are as follows; Al ; $1.712{\sim}31.230mg／kg$, As ; $0.062{\sim}0.439mg／kg$, Cd ; $0.010{\sim}0.062mg／kg$, Co ; $0.000{\sim}0.101mg／kg$, Cr ; $0.125{\sim}0.636mg／kg$, Cu ; $3.385{\sim}12.502mg／kg$, Fe ; $41.148{\sim}99.709mg／kg$, Hg ; $0.000{\sim}0.270mg／kg$, Mn ; $0.433{\sim}2.301mg／kg$, Ni ; $0.000{\sim}0.221mg／kg$, Pb ; $0.000{\sim}0.584mg／kg$, Se ; $0.540{\sim}1.600mg／kg$, Zn ; $8.775{\sim}17.060mg／kg$, by groups, respectively. The concentration of Cu, Se, Cr, and Hg are variated significantly in control and other experimental group, and Cu, Se, Cd, Cr are variated significantly in experimental I and other experimental II, III, IV, V groups. 4. The amount of each metal analyzed in the bone(tibia and fibula) are as follows; Al ; $9.557{\sim}119.464mg／kg$, As ; $0.139{\sim}12.250mg／kg$, Cd ; $0.000{\sim}0.295mg／kg$, Co ; $0.022{\sim}0.243mg／kg$, Cr ; $0.239{\sim}1.999mg／kg$, Cu ; $0.000{\sim}2.291mg／kg$, Fe ; $240.249{\sim}841.956mg／kg$, Hg ; $0.000{\sim}0.983mg／kg$, Mn ; $0.214{\sim}7.353mg／kg$, Ni ; $5.473{\sim}11.453mg／kg$, Pb ; $0.000{\sim}8.502mg／kg$, Se ; $0.000{\sim}3.005mg／kg$, Zn ; $61.158{\sim}195.038mg／kg$, by groups, respectively. The concentration of Se, Cd are variated significantly in control and other experimental groups, and Se is variated significantly in experimental I and other experimental II, III, IV, V groups. 5. Exceptionally several metal concentration is increased or decreased. but there is no significant harmful difference of metal concentration in the liver, kidney and bone, from the OD-treated-rats compared to those of the control group even if higher dosage($1{\sim}8$ times dosage of person) of OD was administered. Thus, it is expected that the herbal decoction in the traditional herbal medicine would not lay any burden on the body and the heavy metal toxins would not affect our physiological system. However, other kinds of herbal treatment, such as i.v. and i.p. should be considered in terms of metal toxicity in the body since the level of certain metal.

• Journal of Radiation Protection and Research
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• v.42 no.3
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• pp.158-165
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• 2017

Background: Nuclear facilities in South Korea have generally adopted pressurized ion chambers to measure ambient gamma ray exposure rates for monitoring the impact of radiation on the surrounding environment. The rates assessed with pressurized ion chambers do not distinguish between natural and man-made radiation, so a further step is needed to identify the cause of abnormal variation. In contrast, using NaI(Tl) scintillation detectors to detect gamma energy rates can allow an immediate assessment of the cause of variation through an analysis of the energy spectra. Against this backdrop, this study was conducted to propose a more effective way to monitor ambient gamma exposure rates. Materials and Methods: The following methods were used to analyze gamma energy spectra measured from January to November 2016 with NaI detectors installed at the Korea Atomic Energy Research Institute (KAERI) dormitory and Hanbat University. 1) Correlations of the variation of rates measured at the two locations were determined. 2) The dates, intervals, duration, and weather conditions were identified when rates increased by $5nSv{\cdot}h^{-1}$ or more. 3) Differences in the NaI spectra on normal days and days where rates spiked by $5nSv{\cdot}h^{-1}$ or more were studied. 4) An algorithm was derived for automatically calculating the net variation of the rates. Results and Discussion: The rates measured at KAERI and Hanbat University, located 12 kilometers apart, did not show a strong correlation (coefficient of determination = 0.577). Time gaps between spikes in the rates and rainfall were factors that affected the correlation. The weather conditions on days where rates went up by $5nSv{\cdot}h^{-1}$ or more featured rainfall, snowfall, or overcast, as well as an increase in peaks of the gamma rays emitted from the radon decay products of $^{214}Pb$ and $^{214}Bi$ in the spectrum. This study assumed that $^{214}Pb$ and $^{214}Bi$ exist at a radioactive equilibrium, since both have relatively short half-lives of under 30 minutes. Provided that this assumption is true and that the gamma peaks of the 352 keV and 1,764 keV gamma rays emitted from the radionuclides have proportional count rates, no man-made radiation should be present between the two energy levels. This study proved that this assumption was true by demonstrating a linear correlation between the count rates of these two gamma peaks. In conclusion, if the count rates of these two peaks detected in the gamma energy spectrum at a certain time maintain the ratio measured at a normal time, such variation can be confirmed to be caused by natural radiation. Conclusion: This study confirmed that both $^{214}Pb$ and $^{214}Bi$ have relatively short half-lives of under 30 minutes, thereby existing in a radioactive equilibrium in the atmosphere. If the gamma peaks of the 352 keV and 1,764 keV gamma rays emitted from these radionuclides have proportional count rates, no man-made radiation should exist between the two energy levels.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2842-2849
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• 2024

The amorphous glasses containing PbO, ZnO, MgO, and B₂O₃ have been fabricated using the melt quenching technique. The structural properties have been analysed using the Fourier-transform infrared (FTIR) and Raman spectroscopy. Derivative of Absorption Spectra Fitting (DASF) method have been used to estimate the band gap energy from the UV-Vis absorption data which decreases from 3.02 eV to 2.66 eV with increasing the concentration of the PbO.The four glass samples 0.284 and 0.826 MeV showed unique variations in terms of gamma attenuation ability. LZMB4 glass sample proved to be the mist effective in terms of shielding of gamma radiation as it requires little distance compared to LZMB3, LZMB2 and LZMB1 to attenuate. RPE revealed a raise with increase in the thickness of the material and reduces as the energy raises. TF is superior in LZMB1 compared to LZMB2, LZMB3 and LZMB4, confirming that, LZMB4 will attenuate better. The Z_Eff of the materials was seen falling as the energy increases, confirming that the linear attenuation coefficient of the glass materials decreases when the energy is increased. The results confirmed that, glass material LZMB4 is the best option especially for gamma radiation shielding applications compared to LZMB3, followed by LZMB2, then LZMB1.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.5
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• pp.11-22
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• 2010

Recently, Fan and Dai introduced a Shifted Polynomial Basis and construct a non-pipeline bit-parallel multiplier for $F_{2^n}$. As the name implies, the SPB is obtained by multiplying the polynomial basis 1, ${\alpha}$, ${\cdots}$, ${\alpha}^{n-1}$ by ${\alpha}^{-\upsilon}$. Therefore, it is easy to transform the elements PB and SPB representations. After, based on the Modified Shifted Polynomial Basis(MSPB), SPB bit-parallel Mastrovito type I and type II multipliers for all irreducible trinomials are presented. In this paper, we present a bit-parallel architecture to multiply in SPB. This multiplier have a space complexity efficient than all previously presented architecture when n ${\neq}$ 2k. The proposed multiplier has more efficient space complexity than the best-result when 1 ${\leq}$ k ${\leq}$ (n+1)/3. Also, when (n+2)/3 ${\leq}$ k < n/2 the proposed multiplier has more efficient space complexity than the best-result except for some cases.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.2
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• pp.21-29
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• 1989

The metals present in atmospheric particulate come from various sources; natural or anthropogenic. Among various metals Fe, Zn, Pb, Cu, and Mn are of particular concern in as much as they are not only present in large quantity, but toxic to human body. A simple, fast, and non-destructive analytical method for these metals in atmospheric particulate was developed and the analytical details were described herein. The method involves the measurements of X-ray fluorescence of sample contained in filters and comparing it with those for standards. The standard filters were prepared by applicating premeasured standard solution to the filters and then drying. The accuracy of the method was tested by analyzing standard reference materials and by independently analyzing samples using a different, previously accuracy-proven method, inductively coupled plasma atomic emission spectrometry, and comparing the results obtained. Analytical sensitivities and detection limits of the present method were 62.9, 178.2, 82.9, 146.1, 37.2, 120.3 cps/$\mug/cm^2$ and 39.0 35.6, 137.5, 125.9, 182.6, 72.8 $ng/cm^2$ for Fe, Zn, Pb, Cu, Mn, and Ni respectively. The method was applied to Seoul atmospheric particulate and some results were reported.