• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.269-279
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• 1984

The optimum conditions for measuring cadmium content of less than 0.2ppm by flame atomic absorption spectrophotometry were investigated. The cadmium in urine was extracted by APDC-MIBK for the analysis by atomic absorption spectrophotometry after ashing them by a wet method. 1. Optimum conditions by APDC-MIBK and DDTC-MIBK extractions. The acidic aqueous solution was prepared with appropriate amount of 0.IN nitric acid, 5ml of 25% (W/V) sodium potasstum tartarate, 10ml of saturated ammonium sulfate, and 2ml of 2% APDC(or 1 ml of 5% DDTC) chelating agent. The total volume of solution was adjusted to 55 ml and pH to $2{\sim}10$ (or$7{\sim}10$). The aqueous solution was extracted with 10ml MIBK. Concentration of Triton X-100 did not effect the absorbance for APDC-MIBK extraction of cadmium, but absorbance decreased as the concentration increased for DDTC-MIBK extraction. The sensitivity and detection limits for the cadmium determination from APDC-MIBK extraction were 0.0038ppm and 0.0102, 0.0022ppm and 0.0116 for DDTC-MIBK, and 0.0132ppm and 0.0034 for 0.1N nitric acid. APDC-MIBK and DDTC-MIBK extractions were 3 times higher than 0.1N nitric acid for the sensitivity. 2. Excretion of cadmium in 24-hour urine by APDC-MIBK extraction. Determination of cadmium in urine by atomic absorption spectrophotometry of A.A. (Cd=2 mA) mode and B.C. (Cd=4 mA) mode and B.C. (Cd=4mA, $D_2=20mA$) mode showed some difference (p<0.05). The difference of cadmium determination and recovery according to method of standard additions and standard calibration curve method in urine was not significant (p>0.05, $93.48{\pm}11.78%,\;94.83{\pm}22.00%$). Excretion of cadmium in 24-hour urine collection from normal person and variance analysis within measurement variation was not significant (p>0.05), but between interindividual was significant (0.05). Determination of cadmium content by two different methods of flame atomic absorption spectrophotometry and dithizone colorimetry showed that the results from the two methods can be described by a regression line with a good correlation (y=1.0153x-0.2927, x=Cd by D.C., y=Cd by A.A.S., $r=0.8651^*$, p<0.01).

• 셀메드
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• 제6권1호
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• pp.3.1-3.4
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• 2016

Consumption of herbal products from the medicinal plants contaminated with heavy metals can cause serious consequences on human health. This is a major concern for traditional and herbal medicine. The present study was carried out to analyze and quantify the levels of six potentially toxic heavy metals namely arsenic, lead, cadmium, mercury, chromium and nickel in ten important Indian medicinal herbs. The air dried raw herbs were processed by microwave assisted wet digestion and analyzed by using atomic absorption spectrophotometer equipped with graphite tube atomizer. Except the chromium content in three plants, all the levels of six heavy metals analyzed were found to be quite below the permissible limits in all the ten raw medicinal herbs analyzed. The present work implies that, regular and systematic screening of raw medicinal herbs is necessary to check the levels of the heavy metal contaminants before using them for consumption or preparation of herbal formulations so that the possible contamination cannot cumulate up to the finished products.

• 방사성폐기물학회지
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• 제8권3호
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• pp.201-205
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• 2010

고준위방사성폐기물에서 유출되어 나오는 아이오딘의 이동을 저지하기 위하여 은을 흡착시킨 벤토나이트 블록에 NaI 용액을 흘려주었을 때 대부분의 아이오딘이 흡착되었다. 이 은이온에 의한 아이오딘의 저지 메커니즘을 상세히 조사하기 위하여 아이오딘과 접촉하기 전후의 은이 흡착된 벤토나이트의 X-ray Absorption Near Edge Structure (XANES)와 Extended X-ray Absorption Fine Structure (EXAFS) 스펙트 럼과 표준물질로서 AgO, $Ag_2O$, AgI의 스펙트럼을 비교하였다. 그 결과, 벤토나이트에 흡착되었던 은이 떨어져 나와 AgI 침전 클러스터를 형성함으로서 아이오딘의 이동이 지연되는 것으로 생각된다.

• 방사선산업학회지
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• 제6권3호
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• pp.211-215
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• 2012

In this study, crosslinked polyethylene (PE) foam sheets were prepared through gamma-ray irradiation. PE foam sheets were prepared through a foaming process using sodium bicarbonate as a blowing and foaming agent. The prepared PE foam sheets were then crosslinked through gamma-ray irradiation. The crosslinking degree was increased to 86.0% with an increase in the absorption dose. The tensile strength of the crosslinked PE foam sheets was increased with an increase in the absorption dose. However, the elongation-at-break of the crosslinked PE foam sheets was decreased. The thermal decomposition temperature of the crosslinked PE foam sheets was increased to $421.2^{\circ}C$ with an increase in the absorption dose. The SEM analysis revealed that the morphology was not changed significantly after the crosslinking through gamma-ray irradiation.

• 대한기계학회논문집A
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• 제22권4호
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• pp.826-833
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• 1998

The energy-absorbing characteristic of impact limiters affects the cask design so significantly that it should be evaluated as accurate as possible. The objective of this study is to find the influence of the impact limiter's steel case and gusset plates which enclose the shock absorbing cellular material on the impact energy absorption. The influence of impact limiter's steel case and gusset plate stiffeners on the impact energy absorption behavior under horizontal drop impact was evaluated for a radioactive isotope transport cask. Though the impact limiters mitigate the impact damage of the cask, the impact limiter's steel case and gusset plate stiffeners increase the impact force so significantly that should be designed as soft as possible. The impact analysis without considering impact limiter's steel case and gusset plates stiffener gives non-conservative results, so the stiffness of the steel case and gusset plates should be considered in impact analysis.

• 자원환경지질
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• 제45권2호
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• pp.205-215
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• 2012

금속이온은 토양이나 퇴적물 내의 광물에 수착되어 고착화될 수 있다. 여기서는 광물 표면의 화학적 특성과 금속이온의 수착에 관련된 이론 및 수착 연구를 위한 X-선 흡수 미세구조(extended X-ray absorption fine structure, EXAFS) 분석방법에 대해 알아보고 금속이온의 광물표면 수착에 관한 원자 단위 연구 결과를 정리하였다. 광물표면의 특성과 금속이온의 수착에 관한 원자 단위 이론의 이해는 원자 단위 분광법의 분석을 수행하는데 있어서 기초가 된다. 여기에 정리된 원자 단위 수착상 연구 결과는 외부권 착물, 내부권 착물, 표면침전뿐 아니라 공침전, 삼성분 착물, 수착반응 시간의 효과, 탈착가능성을 포함한다.

• 분석과학
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• 제13권2호
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• pp.151-157
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• 2000

수소화물 발생법-원자흡수 분광계를 이용한 비소의 분석에서 금속이온의 은폐제로 사용되는 L-cysteine, thiourea, KI/ascorbic acid 등의 예비 환원제와 염산, 질산, 황산 및 이들의 1:1 혼산의 종류 및 농도가 비소의 분석에 미치는 영향을 비교 연구하였다. 대부분의 예비 환원제의 경우 3-5M 이상의 고농도 산 용액에서 비소에 대한 높은 흡괌도를 나타냈으나, 0.1M 이하의 낮은 산 용액에서는 L-cysteine을 제외하고는 극히 저조한 흡광도를 나타내었다. 질산 산성용액에서는 흡광도 신호의 불안정성이 심하였다. 방해물질로서 $Cr^{6+}$, $Br^{5+}$ 이온의 방해영향이 크게 관찰되었지만, 이때 예비 환원제는 수소화물 생성을 크게 증가시켰다.

• Journal of Radiation Protection and Research
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• 제31권1호
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• pp.47-52
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• 2006

$0.3g/cm^3$ 에서 $1.5g/cm^3$까지 다양한 겉보기 밀도를 갖는 감마방출핵종 환경시료의 정확한 방사능 분석을 위해서 자체흡수보정(self-absorption correction)은 중요한 문제이다. 방사선 표준선원을 밀도별로 제작할 필요없이 마리넬리 비커를 감싸는 외부용기를 새롭게 제작하여 실용적이면서 간단한 자체흡수보정방법을 본 논문에서 제시하였다. 밀도 0.8, 1.0, $1.3g/cm^3$ 대해서 새로운 방법을 이용하여 자체흡수보정을 한 효율들과 밀도별로 직접 표준선원용액을 만들어 측정한 효율값이 4 % 이내에서 일치하였다.

• 한국산업보건학회지
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• 제1권2호
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• pp.214-220
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• 1991

As chromium in urine remains as oxychromic acid ions, chromium was extracted by using ion pair formed by anion exchanger trioctylamine. then after it is noted whether this TOA-MIBK method is effective or not for the chromium analysis by using flame method of Atomic absorption Spectrophotometric Analysis. The result is as following. 1. Effects of various acids on the extraction of Cr with MIBK including TOA are good in order $NHO_3$, $H_2SO_4$, HCl in distilled water sample and its proper concentration of HCl is 0.2 N. 2. For the analysis of urine sample, the best result can be achieved by following condition. After finished pretreatment adjusted to pH 6.5-7.5 by NaOH and again controlled pH 0.5-0.6 by HCl. 3. Though TOA concentration slightly affects the analytic value, best result is noted in 1-3% concentration. 4. Recovery rates of urine samples made by $0.3mg/l{\cdot}urine$, $0.6mg/l{\cdot}urine$, $0.9mg/l{\cdot}urine$ are shown from 96.7% to 104.8%. 5. Recovery rates of urine samples made by $0.01mg/l{\cdot}urine$, $10.03mg/{\cdot}urine$, $0.05mg/l{\cdot}urine$ are shown from 89.3% to 98.6%.

• 한국미생물·생명공학회지
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• 제36권3호
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• pp.221-226
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• 2008

효모에서 사람의 H-, L-ferritin을 생산하기 위해서, 기존에 복제된 vector를 사용하였으며,단백질을 발현하기 위해서 각각의 증폭된 ferritin 유전자를 GALI promoter에 의해 조절되는 pYES2.1/V5-His-TOPO 효모 발현 vector에 삽입하였다. Western blot 분석을 통해서 사람의 H-, L-ferritin subunits을 함유한 재조합 효모에서 사람의 ferritin이 발현된 것을 확인할 수 있었다. 또한 Atomic absorption spectrometry(AAS) 분석을 통해서 형질변환된 효모의 철 함유량이 대조군과 비교하여 $1.6{\sim}l.8$배 증가한 것을 확인하였다. 향후 ferritin이 함유된 형질변환 효모를 사용하여 잠재적으로 철이 강화된 영양성분을 기능성 식품과 사료에 이용할 수 있을 것이다.