• Title/Summary/Keyword: liquid scintillation counting

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Some Factors Effect on the Detergency of Triglyceride (Triglyceride의 세척성에 영향을 미치는 몇가지 요인)

  • Lee Mee Sik;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.5 no.1
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    • pp.15-21
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    • 1981
  • The effect of fatty acid content in oily soil and conditions of washing on the removal of triglyceride have been studied. Cotton lawn was soiled with the four-component soil-tripalmitin, palmitic acid, dodecyl alcohol and dodecane-and washed in constant temperature waterbath shaker. The detergency was estimated by analysis of triglyceride labelled carbon-14 on fabrics before and after washing by means of liquid scintillation counting. It was shown that the detergency of triglyceride washed with the nonionic, nonylphenol poly (10)-ethylene oxide and soap was increased steadily with increasing temperature, whereas with the anionics Na-DBS and SLS, the detergency was rather decreased when the temperature was elevated above $40^{\circ}C$. To investigate the effects of free fatty acid content in soil on the removal of triglyceride, the fabrics were soiled altering palmitic acid content, and then washed. From the results, the detergency of triglyceride was developed with increasing free fatty acid content. With soils containing less than $30\%$ of free fatty acid, of the three detergents tested, the nonionic was by far the most effective soil removal. Soap was intermediate and the synthetic anionic was the poorest. With soil containing $45\%$ of free fatty acid, soap was the most effective soil removal. When NaOH was added to detergent solution. the detergency of triglyceride was improved without regard to detergents. The optimum alkalinity was obtained according to free fatty acid content. And the alkalinity changed to low NaOH concentration with increasing free fatty acid content. From the results mentioned above, it could be concluded that the major removal mechanisms of triglyceride containing oily soil were mesomorphic phase formation, solubilization and soap forma-tion when alkali was added in detergent solution.

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Distribution of 90Sr Activities in the Environmental Radiation Samples of Jeju Island, Korea

  • Han, Chung Hun;Park, Youn Hyun;Lee, Young Gyu;Park, Jae Woo
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.418-423
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    • 2016
  • Background: This work was to get information about $^{90}Sr$ contamination of the environment by using soil and moss from selected areas in Jeju Island, Korea. Materials and Methods: The activities of $^{90}Sr$ in soil and moss samples were investigated at nine locations of Jeju island, Korea. The soil samples have been collected at 4 sites of Jeju island during June to August of 2013, analyzed for vertical distribution of $^{90}Sr$ activities. The moss samples have been collected at 5 sites of Jeju island during November of 2011 to June of 2012, and analyzed for radioactive $^{90}Sr$. Results and Discussion: The $^{90}Sr$ vertical concentrations in the investigated soil samples were 2.77 to $18.24Bq{\cdot}kg^{-1}$ in eastern part, 1.69 to $18.27Bq{\cdot}kg^{-1}$ in northern part, 3.76 to $13.46Bq{\cdot}kg^{-1}$ in the western part and 1.09 to $8.70Bq{\cdot}kg^{-1}$ in the southern part of the Mt. Halla in Jeju island, respectively. Activities of $^{90}Sr$ show the highest value at the surface soil and decrease with depth. The activity concentration measured was in the range of 79.6 to $363Bq{\cdot}kg^{-1}$ -dry moss. Conclusion: This material is expected to be basis reference for survey of environmental radioactivity in Jeju Island.

Nasal Absorption of Procyclidine in Rats and Dogs

  • Jang, Eun-Ju;Lee, Young-Joo;Chung, Suk-Jae;Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.24 no.3
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    • pp.219-223
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    • 2001
  • Nasal absorption of procyclidine, a synthetic anticholinergic compound, was investigated in Wistar rats and Beagle dogs. The dosing solution was prepared by dissolving$^{14}C$-procyclidme in 50% ethanolic saline. The dosing solution was administered intravenously and intranasally to rats at a dose of 0.6 mg/kg (i.e., $60{\mu}$l/kg in the form of a 1% w/v solution), and intravenously, orally and intranasally to doss at a dose of 0.3 mg/kg(i.e., $6{mu}$l/kg in the form of a 5% w/v solution). Blood samples were taken from an artery of the animals through the catheter for periods of 1200 (for rats) and 1440 min (for dogs), and the radioactivity in the samples was determined by liquid scintillation counting. The nasal bioavailability of Procyclidine in rats and dogs, based on the radioactivity was calculated to be 81.1 and 98.6% respectively. In both rats and dogs, the plasma profiles of procyclidine following nasal administration were very close to those following intravenous administration, leading to nearly superimposable profiles between the two protocols. In dogs, nasal administration resulted in significantly higher plasma concentrations during the first 30 min period compared to oral administration, suggesting the superiority of the nasal route over the oral route in terms of a prompt expression of the pharmacological effect of the drug. The results obtained in this study indicate that procyclidine is rapidly and nearly completely absorbed via the nasal route. In conclusion, nasal administration represents a viable alternative to intravenous administration in the case of procyclidine.

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Adenyl Cyclase Activity in Cold-acclimatized Animals (한냉적응이 Adenyl Cyclase Activity에 미치는 영향)

  • Kang, Bok-Soon;Lee, Sang-Ho;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.8 no.2
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    • pp.67-74
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    • 1974
  • The object of this research is aimed to determine the activity of adenyl cyclase in both skeletal muscle sarcolemma and fat cell ghost of epididymal adipose tissue isolated from rats exposed to cold for various length of time in an attempt to evaluate whether the tissue sensitivity to catecholamine is increased when rats are exposed to cold for long periods of time Methods: a)Animals: Albino rats ranging in weight from 150 to 200 gm were used throughout this study. For experimental purposes, the rats are divided into two groups: experimental animals were place4 in a cold room at $4^{\circ}C$, controls being kept at $25^{\circ}C$. At the end of 2, 4, 6, 12, and 16 weeks. exposure to cold the rats were used to measure the adenyl cyclase activity. b) Isolation of plasma membrane from skeletal muscle and adipose tissue: The Plasma membrane of skeletal muscle from hind limbs of rats are prepared by the method employed by Rosenthal et at. and fat cell ghost of epididymal adipose tissue of rats by the method employed by Rodbell. c) Adenyl cyclase assay: Adenyl cyclase activity were measured by the method employed by Marinetti et al. Briefly, plasma membrane was incubated with $3^H-ATP$, various amount of noradrenaline and other incubation mixture at $37^{\circ}C$ for 20 minutes. After stopping the enzyme reaction by immersion in boiling water, carrier 3',5'-AMP was added to the system as a marker and $100\;{\mu}1$ aliquots of incubation mixture were pipetted on $20{\time}20$ Whatman No. 3 MM filter paper for one dimensional chromatography. The cyclic AMP spots were cut off and placed in counting vials containing 10ml of Bray's scintillation cocktail. Radioactivity was determined with a Packard Tri-Carb liquid scintillation counter. The enzyme activity is expressed as nanomoles of cyclic AMP produced per mg of membrane per hour. Result: 1. Average adenyl cyclase activity in the plasma membrane of skeletal muscle before and after noradrenaline administration was significantly higher in the cold-exposed rats as compared to the control. Continuous exposure to cold Produced an increased adenyl cyclase activity before and after noradrenaline administration. Adenyl cyclase activity reached peak levels at the 6 weeks exposure to told and level of adenyl cyclase activity remained high. Noradrenaline administration to the incubation medium induced a significant increase in adenyl cyclase activity and the degree of stimulation were proportional to the hormonal concentration But the rate of inclement in adenyl cyclase activity by noradreasline was the same in both groups. 2. Adenyl cyclase activity in fat cell ghost between cold exposed and control rats showed no significant differences before and after noradreualine administration. In summary, it can be concluded that cold adaptation give rise an increased activity of adenyl cyclase in plasma membrane of skeletal muscle in rats.

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Determination of $^{14}C$ in Environmental Samples Using $CO_2$ Absorption Method ($Co_2$ 흡수법에 의한 환경시료중 $^{14}C$ 정량)

  • Lee, Sang-Kuk;Kim, Chang-Kyu;Kim, Cheol-Su;Kim, Yong-Jae;Rho, Byung-Hwan,
    • Journal of Radiation Protection and Research
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    • v.22 no.1
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    • pp.35-46
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    • 1997
  • A simple and precise method of $^{14}C$ was developed to analyze $^{14}C$ in the environment samples using a commercially available $^{14}CO_2$ absorbent and a liquid scintillation counter. An air sampler and a combustion system were developed to collect HTO and $^{14}CO_2$ in the air and the biological samples simultaneously. The collection yield of $^{14}CO_2$ by the air sampler was in the range of 73-89% . The yield of the combustion system was 97%. In preparing samples for counting, the optimum ratio of $CO_2$ absorbent to the scintillator for mixing was 1:1. No variation of the specific activity of $^{14}C$ in the counting sample was observed up to 70 days after preparation of the samples. The detection limit for$^{14}C$ was 0.025 Bq/gC, which is the level applicable to the natural level of $^{14}C$. The analytical result of $^{14}C$ obtained by the present method were within ${\pm}6%$ of the relative error from the one by the benzene synthesis. The specific activity of $^{14}C$ in the air collected at Taejon during the period of October 1996 ranged from 0.26 to 0.27 Bq/gC. The specific activity of $^{14}C$ in the air collected at 1km from the Wolsong nuclear power plant a 679 MWe PHWR, was $0.54{\pm}0.03$ Bq/gC. The ranges of specific activities of $^{14}C$ in the pine needles and the vegetations from the areas around the Wolsong nuclear power plant were 0.56-0.67 Bq/gC and 0.23-1.41 Bq/gC, respectively.

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Radioanalytical and Spectroscopic Characterizations of Hydroxo- and Oxalato-Am(III) Complexes (방사분석과 분광학을 이용한 Am(III) 가수분해와 옥살레이트 착물 화학종 연구)

  • Kim, Hee-Kyung;Cho, Hye-Ryun;Jung, Euo Chang;Cha, Wansik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.4
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    • pp.397-410
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    • 2018
  • When considering the long-term safety assessment of spent-nuclear fuel management, americium is one of the most radio-toxic actinides. Although spectroscopic methods are widely used for the study of actinide chemistry, application of those methods to americium chemistry has been limited. Herein, we purified $^{241}Am$ to obtain a highly pure stock solution required for spectroscopic studies. Quantitative and qualitative analyses of purified $^{241}Am$ were carried out using liquid scintillation counting, and gamma and alpha radiation spectrometry. Highly sensitive absorption spectrometry coupled with a liquid waveguide capillary cell and time-resolved laser fluorescence spectroscopy were employed for the study of Am(III) hydrolysis and oxalate (Ox) complexation. $Am^{3+}$ ions under acidic conditions exhibit maximum absorbance at 503 nm, with a molar absorption coefficient of $424{\pm}8cm^{-1}{\cdot}M^{-1}$. $Am(OH)_3(s)$ colloidal particles formed under near neutral pH conditions were identified by monitoring the absorbance at around 506-507 nm. The formation of ${Am(Ox)_3}^{3-}$ was detected by red-shifts of the absorption and luminescence spectra of 4 and 5 nm, respectively. In addition, considerable enhancements of the luminescence intensities were observed. The luminescence lifetime of ${Am(Ox)_3}^{3-}$ increased from 23 to 56 ns, which indicates that approximately six water molecules are replaced by carboxylate ligands in the inner-sphere of the Am(III). These results suggest that ${Am(Ox)_3}^{3-}$ is formed through the bidentate coordination of the oxalate ligands.

Determination of Tritium in Spent Pressurized Water Reactor (PWR) Fuels (가압 경수로 사용후핵연료 중 삼중수소 분석)

  • Lee, Chang Heon;Suh, Moo Yul;Choi, Kwang Soon;Jee, Kwang Yong;Kim, Won Ho
    • Analytical Science and Technology
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    • v.17 no.5
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    • pp.381-387
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    • 2004
  • To characterize chemically a spent pressurized water reactor (PWR) fuel, an analytical method for trace amounts of tritium ($^3H$) in it has been established. Considering the effective management of radioactive wastes generated through the whole experimental process and the radiological safety for analysts, a separation condition under which $^{14}C$ and $^3H$ can be sequentially recovered from a single fuel sample was optimized using simulated spent PWR fuel dissolved solutions. $^{14}CO_2$ evolved during dissolution of the spent PWR fuels with nitric acid was trapped in an aliquot of 1.5 M NaOH. $^{129}I_2$ which was volatilized along with $^{14}CO_2$ was removed using a silver nitrate-impregnated silica gel absorbent. $^3H$ remaining in the fuel dissolved solution as $^3H_2O$ was selectively recovered by distillation. Its recovery yield was 97.9% with a relative standard deviation of 0.9% (n=3). $^3H$ in a spent PWR fuel with burnup value of 37,000 MWd/MtU was analyzed, reliability of this analytical method being evaluated by standard addition method.

A Study on the Detergency of Alkali-treated Polyester Fabric - The effects of surface structure- (알칼리 감양가공이 Polyester 직물의 세척성에 미치는 영향 -표면구조의 효과를 중심으로-)

  • Shin Rae Won;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.10 no.2
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    • pp.1-9
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    • 1986
  • To study the effects of surface structure of fiber on the decrement of fatty soil removal at high temperature, the following variables were selected: controled and alkali-treated P.E.T.(polyester) fabrics and chopped fibers as substrates to estimate the detergencies, different aging methods of soiled substrates, and different washing temperatures and surfactant solutions. Radiotagged tripalmitin was used as soil and the detergency was estimated by means of liquid scintillation counting method. The results were as following: The surface of the fiber became rough with many grooves and the hydrophilicity of the fiber was increased and the structure of the fabric became loose by alkali treatment. While the detergency of alkali-treated P.E.T. fabric was better than that of controled P. E. T. fabric, there was no significant differences between the detergencies of controled and alkali-treated chopped fibers. These results indicate that the increment of detergency of alkali-treated P.E.T. fabric is mainly resulted from the changes of fabric structure and the improved hydrophilicity of fiber by alkai treatment. The detergency of tripalmitin was increased with elevating temp. below the m.p. of tripalmitin, was decreased around the m.p., and again was increased above the m.p ..It is considered that the decrement of detergency around the m.p. is due to the diffusion of molten tripalmitin into the grooves on fiber surface, the inner part of fiber, and between fibers. When controled and alkali-treated soiled fabrics and soiled chopped fibers were washed in the distilled water and in the Na-DBS solution respectively, below $60^{\circ}C$ detergencies of alkali-treated fabrics and chopped fibers were improved. However above $60^{\circ}C$ this result was reversed. Therefore these results are regarded as the effects of grooves on fiber surface at high temp. and improved hydrophilicity at low temp. by alkali treatment. When controled and alkali-treated soiled fabrics and soiled chopped fibers were hot-aged before washing, the detergencies of both species were decreased generally. Because the soil was diffused into the grooves on fiber surface, the inner part of fiber, and between fibers during hot-aging. The detergencies of hot-aged species were also decreased above certain temp.. These results suggest that the decrement of detergency at high temp. be resulted not only from the diffusion of soil into the grooves on fiber surface, the inner part of fiber, and between fibers, but also from the characteristics of surfactant solutions.

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A Study on Bioassay of Tritium($^{3}H$) Radioacitivity (三重水素($^{3}H$) 放射能의 生理分析에 關한 硏究)

  • 황선태;오필재;김원식
    • Journal of Korean Society for Atmospheric Environment
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    • v.3 no.1
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    • pp.27-33
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    • 1987
  • The environment and biological studies of tritium have been carried out in the advanced countries since the mid 1950's. In the case of a potential tritium exposure, the usual procedure is trifium bioassay (as HTO) in human urine in order to determine the amount of tritium deposited in the body called tritium body burden. The maximum permissible body burden(MPBB) of tritium in total body is about $30{\mu}Ci/{\ell}$ for body tissue. In the bioassay, the most common investigation level for detection of tritium in urine is 1/10th of MPBB. For this bioassay project, the first priority is given to obtaining a quench correction curve. This consideration is necessary because of the variability in color of human urine specimens. Quenching effect in this case mainly is caused by the absorption of scintillation light flashes by the urine sample. By the least squares method on the statistical basis, an estimated formula for quench correction curve was determined to be Y = 0.771 + 1.836 ${\tmes}10^{-4}$X, where the efficiency(Y) was ranged from about 12% to 31% in the liquid scientillation counting. In this paper, a brief theory concerning the biological half-life of tritium and the retention formula to apply to systematically distributed tritium are described.

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Radioactivity Analysis of $^{55}Fe\;and\;^{63}Ni$ in Dismantled Concrete (해체 콘크리트 폐기물에 포함된 $^{55}Fe$$^{63}Ni$ 방사능 분석)

  • Kang, Mun-Ja;Chung, Kun-Ho;Hong, Sang-Bum;Choi, Geun-Sik;Lee, Chang-Woo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.1
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    • pp.19-27
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    • 2007
  • Combined method of extraction chromatography and liquid scintillation analysis was established for determinating $^{55}Fe\;and\;^{63}Ni$ radioactivity in solid samples. Activated concrete wastes generated from dismantling KRR-2 were analysed. The sequential separation including precipitation and extraction chromatography resulted in the above 90% chemical recoveries of Fe. Above 62% recoveries of Ni were obtained by this procedure exception to 43.6 and 46.5% recoveries. The seperation and counting procedure was also confirmed with spiked samples of known quantity. The measured and spiked quantity were agreed with the 3.7% and 0.7% variations in the $^{55}Fe\;and\;^{63}Ni$ experiments, respectively. The radioactivities of $^{55}Fe$ in the dismantled concretes are shown from below MDA to maximum 362 Bq/g. The radioactivities of $^{63}Ni$ in all concrete samples are below MDA. The $^{63}Ni$ doesn't exist in dismantled concretes from KRR-2. The radioactivity of $^{55}Fe$ is decreased rapidly as the sampling depth is increased from the concrete surface.

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