• Title/Summary/Keyword: CI-이온

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Measurement of Absorbed Dose at the Tissue Surface from a Plain $^{90}Sr+^{90}Y$ Beta Sources (조직 표면에서의 베타선 흡수선량 측정)

  • Hah, Suck-Ho;Kim, Jeong-Mook;Yook, Chong-Chul
    • Journal of Radiation Protection and Research
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    • v.16 no.2
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    • pp.17-26
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    • 1991
  • Beta ray $(^{90}Sr+^{90}Y)$ absorbed dose at tissue surface was measured from the distance of 30cm by use of extrapolation chamber. In the measurement, following factors were considered: effective area of collecting electrode, polarity effect, ion recombination and window attenuation. The measured absorbed dose rate at tissue surface was $1.493{\mu}Gy/sec$ with ${\pm}2.9%$.

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Studies on the Behaviour of Radionuclides in the Soil-Plant System;1) On the Uptake of Cesium-137 by Soybean (토양(土壤)-식물계(植物界)에 대(對)한 방사성핵종(放射性核種)의 거동(擧動)에 관(關)한 연구(硏究);I. 대두작물(大豆作物)에 의(依)한 Cs-137의 흡수이행(吸收移行))

  • Ryu, Joon;Kim, Jae-Sung;Lee, Young-Il
    • Korean Journal of Environmental Agriculture
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    • v.2 no.1
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    • pp.30-34
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    • 1983
  • The present study was carried out to determine the effect of a radionuclide, cesium-137, in soybean, which is an element released usually from nuclear facilities. Soybean plants were grown on the pots treated with cesium-137 $0.5{\sim}60{\mu}Ci/1kg$ soil and the uptake, translocation and accumulation of the radiocesium in the plant parts were measured at different growth stage. The results are summarized as follows: 1) Visual toxic symptoms on the plants due to treatment of radioactive cesium were not observed up to $60{\mu}Ci/10Kg$ soil in a pot. 2) The uptake of cesium-137 in soybean plant was increased with increment of concentration applied, while the uptake of potassium was proportionally decreased, indicating to have an ion antagonistic relationship between them. 3) The absolute amounts of cesium-137 in the plants were gradually increased by the pod setting stage, but rather reduced at harvesting stage. The accumulation occurred more in the leaves and stems than the soybean seeds. 4) The rate of uptake was ranged from 0.069 to 0.005 with proportional decrease by increasing concentration applied and the rate of Cs-137 translocation from plants to seeds was averaged 38.6% in soybean plant. The concentration coefficient was 0.04 in the soybean seeds from the pots treated with $20{\mu}Ci$ of cesium-137 and decreased with increment of cesium-137 applied.

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Geochemical Characteristics and Origin of Dissolved Ions in the Han River Water (한강 하천수 중 용존이온의 지구화학적 특성과 기원)

  • 김규한;심은숙
    • Economic and Environmental Geology
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    • v.34 no.6
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    • pp.539-553
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    • 2001
  • Geochemical data of the Han river water, including four tributary water samples in the main Han river are presented in this paper. The concentration of dissolved ions in the North Han river water decreases in order of Ca>Na>K>Mg and HCO$_3$>NO$_3$>SO$_4$>Cl, which it mainly affected by the chemical weathering of granite and gneiss in the drainage basin. Meanwhile, the South Han river water shows a decreasing order of Ca>Mg>Na>K and HCO$_3$>SO$_4$>NO$_3$>Cl, which is controlled by the bed rock geology of carbornate rooks and the inflow of acid mine drainage from the metal and coal mines in the Taebaegsan and Hwanggangri areas. The main Han river waters are characterized by unusually high concentration of Na, Cl and SO$_4$ (Ca>Na>K>Mg and HCO$_3$>SO$_4$>CI>NO), indicating a significant anthropogenic pollution by human activities in the metropolitan Seoul city. The geochemical data of the Han river waters from 1981 through 1996 to 1999 records a significant increase in SO$_4$ and NO$_3$, which responsible for the increasing arid mane drainage and municipal anthropogenic pollution.

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Real-Time XRD Analysis of Polystyrene/Clay Nanocomposites by In-Situ Polymerization (In-situ 중합법에 의한 폴리스티렌/점토 나노복합재료의 실시간 X선 분석)

  • Kim, Jang-Yup;Hwang, Seok-Ho;Hong, Yoo-Seok;Huh, Wan-Soo;Lee, Sang-Won
    • Polymer(Korea)
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    • v.29 no.1
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    • pp.87-90
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    • 2005
  • In this study, we have examined the exfoliation behavior of layered clay during in-situ polymeriztion with styrene by using real-time XRD analysis. The 4C1 beam line at the Pohang Accelerator Laboratory (PAL) was used for this study. Different exfoliation behaviors have been shown to depend on the cation exchange capacity (CEC) of clay and the chemical structure of organic modifiers. For 10A-MMT and 15A-MMT having high CEC, no peak shifts were observed on real-time XRD analysis during polymerization. However, 2$\theta$ for 25A-MMT and VDAC-MMT, each having low CEC’s as well as aromatic benzene moieties and vinyl groups, respectively, decreased as polymerization time increased.

Investigation of Alkali-Aggregate Reaction of Abroad Aggregates (Using Area of KOREA Cement) (첨가 이온종류에 따른 외국 골재의 알카리.골재 반응성 조사연구 (한국 시멘트 사용 지역 중심))

  • 현석훈;엄태형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.111-117
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    • 1995
  • The alkali-aggregate reaction is a reaction between the alkali metals in the pore water of a concrete and an unstable mineral of the aggregate. There are three types of alkali-aggregate reation which causes deterioration of concrete, such as alkali-silicate reation, alkali-carbonate reaction and alkali-silica reation. Deterioration due to alkali-silica reation is more comon than that due to either the alkali-silicate or alkali-carbonate reaction. The alkali-silica reation is a reaction between the hydroxyl ions in the pore water of a concrete and silica which exists in signigicant quantities in the aggregate. In this PAPER, Alkali-aggregate reactions of mortar made with various abroad aggregate were investigated using XRD, microscope, chemical and physical tests. In additions, the effects of the texture of aggregate, Na, K, CI ion concentrations added to the mortar, on these reactions were studied.

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An Experimental Study about Characteristics of Penetrating Surface Protection Materials to Promote Concrete Structure Durability (콘크리트 구조체 내구성 향상을 위한 침투성 표면 보호재의 특성에 관한 실험적 연구)

  • Lee Jeoung-Yun;Cho Byoung-Young;Kim Young-Keun;Oh Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.11a
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    • pp.93-96
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    • 2005
  • Concrete has been considered as a semi-permanent structural material, because its excellent durability. Recently, durability decline of concrete construction by environmental pollution is becoming social problem. The durability of high durable structure is declined by carbonate, chloride permeation and deterioration of waterproof performance, etc. This study of penetrating surface protection materials evaluated about carbonation, chloride permeation, waterproof performance, and durability of abrasion, etc. It is profitable in durability that spread penetrating surface protection materials

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Pitting Corrosion Behavuor of N2+ ion Implanted AISI 316L Stainless Steel Compacts (질소 이온주입된 AiSi 316L 스테인리스강 소결체의 공식거동)

  • 최한철
    • Journal of the Korean institute of surface engineering
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    • v.31 no.2
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    • pp.73-80
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    • 1998
  • The aim of this study is to develop sintered stainless steels (SSS) with good mechanical strength, wear resistance, and corrosion resistance by nitrogen ion implantation on the Culated SSS surface. Stainless steel compacts containg Cu (2-10 wt%) were prepared by electroless Cu-pating method which results in the increased3 homogenization in alloying powder. Nitrogen ion implantation was carried out by using N2 gas as the ion source. Nitrogen ions were embedded by an acceleratol of 130keV with doese $3.0\times10^{17}\;ions/\textrm{cm}^2$ on the SSS at $25^{\circ}C$ in$2\times10^{-6}$ torr vacuum. The nitrogen ion implanted SSS obtained from anodic ploarization curves revealed higher corrosion potential than that of nitrogen ion unimplante one. And nitrogen ion implanted 316LSSS had good resistance to pitting corrosion due to the synergistic effect of Mo and N, and the inhibition of $NH_4\;^+$<\TEX>, against $CI^-$<\TEX>.

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Son Conduction Properties of PVDF/PAN based for Lithium Polymer Battery (리튬 폴리머전지용 PVDF/PAN계 전해질의 이온 전도 특성)

  • 이재안;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.374-377
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    • 1999
  • The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li polymer battery. This paper describes temperature dependence of conductivity, impedance spectroscopy, electrochemical properties of PVDF/PAN electrolytes as a function of a mixed ratio. PVDF/PAN based polymer electrolyte films were prepared by thermal gellification method of preweighed PVDF/PAN, plasticizer and Li salt. The conductivity of PVDF/PAN electrolytes was 10-3S/cm. 20PVDF5PANLiCIO$_4$PC$\sub$10//EC$\sub$10/ electrolyte shows the better conductivity of the others. 20P7DF5PANLiCI$_4$PC$\sub$10//EC$\sub$10/ electrolyte remains stable up to 5V vs. Li/Li$\^$+/. Steady state current method and ac impedance used for the determination of transference numbers in PVDF/PAN electrolyte film. The transference number of 20PVDF5ANLICIO$_4$/PC $\sub$10//EC$\sub$10/ electrolyte is 0.48

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Patterns and Interrelationships for Meeting Guidelines of Physical Activity, Sedentary, and Dietary Behavior in Korean Adolescents (한국 청소년의 신체활동, 좌식행동, 식이행동에 대한 가이드라인 실천 패턴 및 상호관련성)

  • Kim, Jae-Woo;Kong, Sung-A;Lee, On;Kim, Yeon-Soo;Yun, E-Hwa;Kim, Shin-Ah;Choi, Bo-Youl
    • The Korean Journal of Community Living Science
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    • v.20 no.3
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    • pp.413-421
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    • 2009
  • The purpose of this study was to analyze the patterns and the interrelationships for meeting guidelines of three health behaviors including physical activity(PA), sedentary behavior(SB), and dietary behavior(DB) for Korean adolescents using 2007 KYRBS(Korea Youth Risk Behavior Survey) data. A cross-sectional design was used to assess 73392 middle-high school students. PA(moderate physical activity${\geqq}$5times/week, or vigorous ${\geqq}$3times/week), SB(watching TV, computer, DVD, video, etc. < 3 hr/day), and DB(servings of fruits ${\geqq}$1 times/day, or vegetables ${\geqq}$ 3 times/day) were categorized into two levels (meeting guidelines or not). Chi-squared tests were conducted to compare the prevalence of students not meeting these three health behaviors between boys and girls, and logistic linear regression was used to determine the interrelationships of three health behaviors. Students meeting guidelines for PA, SB, and DB were 31.0%(boys 42.6%, girls 18.0%), 74.7%(boys 75.4%, girls 74.0%), and 38.5%(boys 38.6%, girls 38.4%), respectively. In addition, there were significant differences between both genders for PA and SB (PA; $x^2(1)$=35175.11, p<.0001, SB; $x^2(1)$=19.44, p<.0001). Only 10.9% of students met all three guidelines and 12.4% did not meet all three. Pattern that simultaneously did not meet PA and DB were high in both boys(27.1%) and girls(37.2%). Students who did not meet DB were at greater risk of not meeting PA(Boys; OR 1.49, 95% CI 1.43 to 1.55, Girls; OR 1.42, 95% CI 1.34 to 1.50), and not meeting SB(Boys; OR 1.41, 95% CI 1.34 to 1.48, Girls; OR 1.36, 95% CI 1.29 to 1.43) compared with students who met DB. The findings of this study supported further evidence for the need of a multiple behavior approach considering gender and interrelationships among three behaviors.

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Physiological Response of Chinese Cabbage to Salt Stress (염 스트레스에 대한 배추의 생리학적 반응)

  • Kim, Ju-Sung;Shim, Ie-Sung;Kim, Myong-Jo
    • Horticultural Science & Technology
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    • v.28 no.3
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    • pp.343-352
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    • 2010
  • In order to understand the plant responses to salt stress (0, 50, and 100 mM NaCl), Chinese cabbage seedlings grown up to two leaf stages by hydroponic culture were used. Fresh and dry weight, chlorophyll (Chl), antioxidant materials, polyamine content, antioxidant enzyme activities, and inorganic ion level were evaluated. Fresh and dry weights of Chinese cabbage increased with the increase in salinity while the optimal growth occurred at 50 mM NaCl. The Chl a, total Chl, carotenoid content, and Chl a/b ratio increased by the 6 days after treatment with 100 mM NaCI; however, the Chl b content decreased. Glutathione increased in the root of Chinese cabbage for 6 days. Dehydroascorbate increased remarkably by day 6 caused by the salt stress in both leaf and the root. While ascorbate peroxidase increased, the activity of catalase and glutathione reductase decreased gradually in the first leaf for 6 days. The $Na^+$ content increased by 12.5-fold in the 3 days after treatment with 100 mM NaCI in the shoot, whereas the $Ca^{2+}$, $K^+$, and $Mg^{2+}$ content measured in the same treatment decreased by 43 to 57%. Spermidine content decreased as salinity increased, but spermine content increased. The growth promotion, glutathione and ascorbic acid content in Chinese cabbage were increased by low salt stress, and shortening of the cultivation period for growth increase of Chinese cabbage is expected.