• 대한수의학회지
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• 제33권3호
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• pp.493-505
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• 1993

Present experiments were undertaken in order to clarify the clinico-pathological characteristics of lead poisoning in goats. Twenty goats were divided into three experimental groups(A, B and C) and a control(D). The three experimental groups received diets contaminated artificially with 10(A group), 200(B group) and $1,000(C group){\mu}g/g$ of lead for 70 days, respectively. The control group received normal diets. Hair samples collected one or two weeks interval were examed for the lead content. On day 70. all the animals were necropsied and various organs were examined pathoanatomically. In addition, various organs were analyzed for lead, zine, copper, iron and calcium content by atomic absorption spectrophotometry. From these experiments following results were obtained ; The lead content of hair was significantly increased from the $42^{nd}$, $21^{st}$ or $14^{th}$ day in all the three groups, which showed significant correlation with lead content of liver and spleen. The lead content of various organs including kidney, liver, spleen, ileum, bone and abomasum were significantly increased in accordance with the lead contamination. The increase was most prominent in abomasal wall. The zinc and copper content of liver, brain, ileum, skin, kidney, lung or muscle were increased in B and C groups whereas the iron and calcium content showed no significant change. Pathoanatomically, degeneration or necrosis of proximal convoluted tubules of kidney, peripheral necrosis of liver, fundic gland necrosis of abomasum and cerebral edema were observed in B and C groups.

• 헤리티지:역사와 과학
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• 제36권
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• pp.241-266
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• 2003

Glass pieces excavated from Mireuksa Temple dated $7^{th}$ century A.D. were characterized by chemical composition, specific gravity and melting point. Lead isotope ratios of lead glasses were also compared with those of lead ore to attribute which lead ore was delivered for making lead glass. It was known that some lead glasses found in Japan were similar with those of Mireuksa Temple as comparing the data of chemical composition and lead isotope ratios. Characteristics of lead glass from Mireuksa Temple Thirty five glass pieces of Mireuksa Temple were analyzed for five oxides and found that all was lead glass system(PbO-$SiO_2$) with the range of 70~79% for PbO and 20~28% for $SiO_2$. The concentrations of oxides such as $Al_2O_3$, $Fe_2O_3$ and CuO were below 0.4%, 0.3% and 0.9%, respectively. Principal component analysis(PCA) as a statistical method was carried out to classify glasses with the similarities of chemical concentrations. The result of PCA has shown that three groups of glasses were created according to the excavation positions and two major oxides(PbO and $SiO_2$) greatly contributed to the dispersion of glasses on principal component 1(PC1) axis and trace element oxides($Al_2O_3$ and $Fe_2O_3$) for PC2 axis. Most of lead glasses were greenish by the efficacy of iron and copper oxides and some showed yellowish-green. The gravity of lead glasses was about 4.4~5.4 and estimated melting point was near $670^{\circ}C$. Lead isotope ratios of glasses were analyzed and found quite close to a lead ore from the Bupyeong mine in Gyeonggi-do. Comparison with lead glasses found in Japan Lead glasses of Mireuksa Temple were compared with those of Japan on the basis of chemical and physical data. Chemical compositions of Japanese lead glasses dated $7^{th}{\sim}8^{th}$ century A.D. were nearly similar with those of Mireuksa Temple but lead isotope ratios of those were separated into two groups. Three distribution maps of lead ores of Korea, Japan and China with lead isotope ratios were applied for lead glasses found in Japan. The result have shown that the locations of lead glasses from Fukuoka Prefecture coincided with the region of northen part of Korea and similar with those of Mireuksa Temple and lead glasses from Nara Prefecture dated $8^{th}$ century A.D. were located in the region of Japanese lead ore. This research has demonstrated that lead glasses of Mireuksa Temple conveyed to Miyajidake site, Fukuoka Prefecture around $7^{th}$ century A.D. and glass melting pots and glass beads excavated from Nara Prefecture confirmed the first use of Japanese lead ore for production of lead glasses from the end of $7^{th}$ century A.D.

• 공업화학
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• 제27권1호
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• pp.21-25
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• 2016

리드프레임에 구리합금소재를 사용할 경우 구리이외의 고농도의 철, 니켈, 아연 등이 포함되며 여기서 발생되는 에칭폐액은 지정폐기물로 지정되어 있다. 따라서 본 연구에서는 전기도금용 산화구리(II)를 제조하기 위해 고농도 중금속을 함유한 리드프레임 에칭폐액의 맞춤형 정제과정을 설계하였다. 리드프레임 에칭폐액의 경우 중금속 함유량이 높아 이온교환수지법 단독으로는 중금속을 제거하는데 한계가 있었다. 따라서 본 연구에서는 물에 대한 용해도차를 이용한 환원-산화법을 연계하여 염화구리(I)을 제조한 후 산화제인 과황산나트륨을 이용하여 염화구리(II)로 재회수하는 방법을 사용하였다. 최적 환원제로는 하이드라진을 선택하였고, 최적 첨가량은 구리 1.0 mol당 1.4 mol이다. 환원-산화법과 이온교환수지법을 연결하여 중금속을 제거할 경우 3회 반복 시 $Fe^{3+}$ (4.3 ppm), $Ni^{2+}$ (2.4 ppm), $Zn^{2+}$ (0.78 ppm)로 전기도금용 산화구리(II) 제조용 원료로 사용이 가능할 것으로 사료된다.

• Toxicological Research
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• 제24권3호
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• pp.227-233
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• 2008

To detect lead ions using electrochemical voltammetric analysis, Infrared Photo-Diode Electrode(IPDE) was applied via cyclic and square wave stripping voltammetry. Lead ions were deposited at 0.5 V(versus Ag/AgCl) accumulation potential. Instrumental measurements systems were made based on a simple and compact detection system. The stripping voltammetric and cyclic voltammetric optimal parameters were searched. The results yielded a cyclic range of $40{\sim}240mgl^{-1}$ Pb(II) and a square wave stripping working range of $0.5{\sim}5.00mgl^{-1}$ Pb(II). The relative standard deviation at 2 and 4 $mgl^{-1}$ Pb(II) was 0.04% and 0.02%(n=15), respectively, using the stripping voltammetric conditions. The detection limit was found to be 0.05 $mgl^{-1}$ with a 40 sec preconcentration time. Analytical interference ions were also evaluated. The proposed method was applied to determine lead ions in various samples.

• 소성∙가공
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• 제11권2호
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• pp.132-137
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• 2002

Using the Taguchi method, optimum process condition of lead frame blanking has been determined in the point of view of shape of blanked profile. As the main process parameters, clearance, strip holding pressure and bridge width are selected. According to the orthogonal array table, three levels of experiment have been carried out for each factor. The optimal blanking condition is analyzed with the SN ratio. It has been verified that the optimal Process condition can be determined with a combination of basic blanking experiment and experiment design method. Both the effect of each factor and gain can be judged in the quantitative manner from the analysis of SN ratio.

• 한국방사선학회논문지
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• 제15권6호
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• pp.789-794
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• 2021

근접방사선치료는 방사선동위원소를 신체 내부에 넣어 종양에 방사선을 집중적으로 조사하는 치료법이다. 근접방사선 치료는 고선량율의 방사선동위원소 선원을 사용하기 때문에 정확한 선원의 위치 및 선량등을 파악하는 것이 매우 중요하다. 하지만 임상에서는 ruler, autoradiograph등을 통하여 육안으로 부정확하게 평가하는 실정이다. 이에 본 연구에서는 Lead(II) Iodide(PbI₂) 물질을 사용하여 방사선근접치료에 사용할 수 있는 선량계를 개발하고, 재현성, 선형성, PID 항목을 분석하여 적용가능성을 평가하였다. 재현성 평가 결과, RSD 값은 1.41%로 평가기준 1.5%를 만족하였다. 선형성 평가결과, R²값은 0.9993으로 평가기준 0.9990을 만족하였다. PID 평가 결과 50% 선량 감약지점에서 거리의 역자승 법칙의 이론값과 비교하여 0.06 cm의 차이만을 나타내었다. 본 실험에서 제작된 선량계는 모든 평가에서 기준치를 만족하는 결과값을 나타내어 방사선근접치료 영역에서의 선량계 적용 가능성이 충분한 것으로 판단된다.

• Membrane and Water Treatment
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• 제11권1호
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• pp.41-48
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• 2020

Lead is a highly toxic heavy metal that causes serious health problems. Nonetheless, it is increasingly being used for industrial applications and is often discharged into the environment without adequate purification. In this study, Pb(II) was removed by powdered waste sludge (PWS) based on the biosorption mechanism. Different PWSs were collected from a submerged moving media intermittent aeration reactor (SMMIAR) and modified Ludzack-Ettinger (MLE) processes. The contents of extracellular polymeric substances were similar, but the surface area of MLE-PWS (2.07 ㎡/g) was higher than that of SMMIAR-PWS (0.82 ㎡/g); this is expected to be the main parameter determining Pb(II) biosorption capacity. The Bacillaceae family was dominant in both PWSs and may serve as the major responsible bacterial group for Pb(II) biosorption. Pb(II) biosorption using PWS was evaluated for reaction time, salinity effect, and isotherm equilibrium. For all experiments, MLE-PWS showed higher removal efficiency. At a fixed initial Pb(II) concentration of 20 mg/L and a reaction time of 180 minutes, the biosorption capacities (q_e) for SMMIAR- and MLE-PWSs were 2.86 and 3.07 mg/g, respectively. Pb(II) biosorption using PWS was rapid; over 80% of the maximum biosorption capacity was achieved within 10 minutes. Interestingly, MLE-PWS showed enhanced Pb(II) biosorption with salinity values of up to 30 g NaCl/L. Linear regression of the Freundlich isotherm revealed high regression coefficients (R² > 0.968). The fundamental Pb(II) biosorption capacity, represented by the K_F value, was consistently higher for MLE-PWS than SMMIAR-PWS.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.65-73
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• 1993

This study was carried out to evaluate the relationship between the biological lead exposure indices and air lead concentrations measured by personal air samplers. The 72 occupationally lead exposed workers were observed and the bioiogical lead Exposure indices chosen for this study were blood lead(PbB), urine lead(PbU), zinc protoporphyrin in whole blood(ZPP), $\delta$-aminolevulinic acid in urine(ALAU), $\delta$-aminolevulinic acid dehydratase activity (ALAD), coproporphyrin in urine(CPU) and hemoglobin(Hb). The workers were divided into four groups by air lead concentrations: Group I; under $0.05mg/m^3$, Group II; $0.05-0.10mg/m^3$, Group III; $0.10-0.15mg/m^3$ and Group IV; and over $0.15mg/m^3$. For evaluation the relationship between the biological lead exposure indices and air lead concentrations was used as correlation coefficients. The results obtained were as follows: 1. In Group I, II, III and IV, the mean value of PbB were $25.45{\pm}1.84{\mu}g/dl,\;27.87{\pm}3.53{\mu}g/dl,\;31.21{\pm}1.76{\mu}g/dl\;and\;47.02{\pm}13.96{\mu}g/dl$. Between Group IV and other groups showed statistically significant difference(p<0.05). 2. There was an increasing tendency of PbB, PbU, ALAU and ZPP according to the increase the mean air lead concentration, while ALAD has decreasing tendency. CPU and Hb did not show any constant tendency. 3. Correlation coefficients between PbB, PbU, ZPP, ALAU, ALAD, CPU, Hb and air lead concentration were 0.95, 0.83, 0.89, 0.72, -0.83, 0.51 and -0.45 respectively, and regression coefficient between PbB(Y) and PbA(X) was Y=126.8746X+16.9996(p<0.01).

• 대한화학회지
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• 제48권6호
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• pp.590-598
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• 2004

수용액 중 흔적량 Cu(II)과 Pb(II)을 알긴산칼슘 비드에 흡착 농축시켜 정량하는 방법에 대해 연구하였다. 알긴산칼슘 비드는 시료용액에 일정량의 Ca(II)과 알긴산을 첨가하여 용액 내에서 형성되도록 하였다. 그리고 효율적인 흡착농축을 위해서 검토해야 할 수용액의 흡착 pH, Ca(II)의 농도, 알긴산의 양, 겔화 방지를 위한 에탄올의 농도, 흡착 평형시간과 탈착을 위해 사용하는 산의 종류 및 농도 등의 조건을 최적화하였다. 흔적량 Cu(II)과 Pb(II)이 포함된 시료 용액에 Ca(II)과 에탄올을 가한 후 용액의 pH를 5.0으로 고정하고, 알긴산을 첨가하여 알긴산칼슘 비드가 용액 내에서 형성되도록 하였다. 흡착 평형이 이루어지면 막 필터로 용액을 거르고, 걸러진 알긴산칼슘 비드를 소량의 완충용액으로 세척한 후 질산용액을 가하여 초음파 세정기에 넣고 역 분산시켰다. 역 분산을 위해 사용하는 탈착제로는 질산이 가장 좋았고, 이때 질산의 농도가 1.0 mol/L 이면 정량적으로 탈착되었다. 공존이온에 대한 방해효과를 Na(I), K(I) 및 Mg(II)에 대해 검토한 결과 Pb(II)에 대해서는 방해효과가 없었으나 과량 존재할 때 Cu(II)에 대해서는 흡광도를 감소시키는 방해를 야기하였다. 2가지 물 시료에 본 방법을 적용한 결과 $90.4{\sim}104.3%$의 회수율을 얻었으므로 수용액 중 흔적량 존재하는 Cu(II)과 Pb(II)을 분리 흡착 농축할 수 있는 효과적인 방법이라고 생각한다.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.406-414
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• 2010

A novel polyacrylamide grafted hydrous ferric oxide adsorbent composite has been synthesized by using glow discharge electrolysis plasma. To optimize the synthesis conditions, the following parameters were examined in detail: applied power, discharge time, post polymerization temperature, post polymerization time, amount of crosslinking agent and hydrous ferric oxide gel added and so on. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The removal percentage of the adsorbent in Pb(II) solution was examined and the data obtained showed that the adsorbent composite has a high capacity for lead ion. For the use in wastewater treatment, the thermodynamic and kinetic of Pb(II)-capture were also studied. Results indicated that the adsorption reaction was a spontaneous and an endothermic process, and it seems to be obeyed a pseudo-secondorder rate model. Moreover, the adsorption isotherm of Pb(II)-capture is following the Langmuir and Freundlich isotherm models.