• Title/Summary/Keyword: P700

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Development of a TL pellet based on $CaSO_4:Dy$ for Neutron Measurement ($CaSO_4:Dy$ 물질 기반 중성자 측정용 TL소자 개발)

  • Yang, Jeong-Seon;Lee, Jeong-Il;Kim, Jang-Lyul;Kim, Bong-Hwan;Sou, Dong-Sup
    • Journal of Radiation Protection and Research
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    • v.31 no.3
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    • pp.129-134
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    • 2006
  • A TL pellet for a neutron dose measurement (KCT-306) by embedding a $^6Li$-compound into a $CaSO_4:Dy$ phohphor was developed based upon the technical information of KCT-300. The KCT-300 is an another kind of $CaSO_4:Dy$ TL detector shich was developed at KAERI, in which small amounts of $NH_4H_2PO_4$ have been emvedded as a binding material. This paper presented the optimized manufacturing condition of KCT-306 and compared its sensitivity with that of the commercialized neutron TL pellets. $CaSO_4:Dy$ Phosphor with grain size ranging less than $45{\mu}m$ are used for the KCT-306. The optimum $CaSO_4:Dy$ TL phosphor, $^6Li$-compounds and P-compound as the binding material are determined as 20-40wt%, 50-70wt% and 20wt%. The TL pellet combination of our KCT-306/KCT-300, TLD-600/TLD-700 and TLD-600H/TLD-700H(Harshaw) have been irradiated in the neutron/gamma mixed fields from a $D_2O$ moderated $^{252}Cf$ neutron source. The KCT-300, TLD-700 and TLD-700H were used at the same time as gamma ray discriminators in the neutron/gamma mixed fields. It was found that the neutron/gamma response ratios of KCT-306/KCT-300, which were developed in this study, were approximately 4 times higher than those of the commercial TLD-600H/TLD-700H.

Quantum well intermixing of compressively strained InGaAs/InGaAsP multiple quantum well structure by using impurity-free vacancy diffusion technique (Impurity-free vacancy diffusion 방법을 이용하여 압축 응력을 가진 InGaAs/InGaAsP 다중양자우물 구조의 무질서화)

  • 김현수;박정우;오대곤;최인훈
    • Journal of the Korean Vacuum Society
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    • v.9 no.2
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    • pp.150-154
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    • 2000
  • We investigated the quantum well intermixing (QWI) of a compressively strained InGaAs/InGaAsP multiple quantum well (MQW) by using impurity free vacancy diffusion technique. The samples with InGaAs/$SiO_2$ capping layer showed a higher degree of intermixing compared to that of InP/$SiO_2$ capping layer after rapid thermal annealing (RTA). Band-gap shift difference as large as 123 meV (195 nm) was observed between samples capped with InGaAs/$SiO_2$ and with InP/$SiO_2$ layer at RTA temperature of $700^{\circ}C$. Using the InGaAs/$SiO_2$ cap layer, the band-gap wavelength of MQW was changed by the intermixing from 1.55 $\mu\textrm{m}$ band to 1.3 $\mu\textrm{m}$ band with a wavelength shift of a 237 nm. The transform from MQW structure to homogenous alloy was observed above the RTA temperature of $700^{\circ}C$.

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Changes of Pulmonary Function and Biopersistence Evaluation of Sepiolite in Sprague-Dawely Rats (랫드에 주입된 세피오라이트에 의한 폐기능 변화 및 생체내구성 평가)

  • Chung, Yong Hyun;Han, Jeong Hee;Sung, Jae Hyuck;Yu, Il Je
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.16 no.4
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    • pp.303-313
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    • 2006
  • Two kinds of sepiolite (sepiolite 1, sepiolite 2), a $500^{\circ}C$ heat treated sepiolite (sepiolite 500), and a $700^{\circ}C$ heat treated sepiolite (sepiolite 700) were analyzed for their physicochemical properties. After these sepiolites were instilled into rat lungs, the effects of these substances on lung function and biochemical changes were evaluated. In addition, the fibers in the lungs were counted and characterized after the lungs were treated for electron microscopical analysis. The lungs instilled with sepiolites increased their weight and tidal volume statistically significantly compared with the unexposed control. The numbers of lymphocytes and polymorphonuclear cells (PMN) in the bronchoalveolar lavage (BAL) fluid also increased compared with the control, indicating the sepiolite induced inflammation. The heat treated sepiolites, however, did not show any toxicological differences from the untreated sepiolites. Although sepiolite showed less change in fiber atomic % compositions ( sepiolite 500, Si 0.9%, p <0.01 ; sepiolite 700, Si 3.7%, p<0.05) than chrysotile (Si 9.7%, p<0.01), the durability of the fibers in the lungs could not be determined in this subchronic experiment.

Effect of irradiation temperature on the nanoindentation behavior of P92 steel with thermomechanical treatment

  • Huang, Xi;Shen, Yinzhong;Li, Qingshan;Li, Xiaoyan;Zhan, Zixiong;Li, Guang;Li, Zhenhe
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2408-2417
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    • 2022
  • The nanoindentation behavior of P92 steel with thermomechanical treatment under 3.5 MeV Fe13+ ion irradiation at room temperature, 400 and 700 ℃ was investigated. Pop-in behavior is observed for all the samples with and without irradiation at room temperature, while the temperature dependence of pop-in behavior is only observed in irradiated samples. The average load and penetration depth at the onset of pop-in increase as the irradiation temperature increases, in line with the results of the maximum shear stress. Irradiation induced hardening is exhibited for all irradiated samples, but there is a significant reduction in the hardness of sample irradiated at 700 ℃ in comparison to the samples irradiated at room temperature and 400 ℃. The ratio of hardness to elastic modulus for all samples decreases with increasing penetration depth except for samples at 700 ℃. With the increasing of irradiation temperature, the ratio of the irreversible work to the total work gradually decreases. In contrast, it increases for samples without irradiation.

Properties of Polyacene Anode Derived from Phenolic Resin (페놀 수지로부터 유도된 Polyacene계 부극의 특성)

  • Oh, Won-Chun;Kim, Bum-Soo;Hwang, In-Soo;Lee, Young-Hoon;Lee, Byung-Eui
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.504-508
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    • 1999
  • We have studied structural charecterization, electrical charge and discharge, and impedence properties for polyacene anode material derived from phenolic resin of novolak type. From the X-ray diffraction results, diffraction patterns for compounds of the three kinds of P-700, P-850, P-1000 were observed for semiirregular structural transition. A electrical charge and discharge data showed that the properties of p-850 was much better than any other samples. From the impedence properties for finding the effect of ions and electron transfer of battery, P-1000 and P-850 of high frequency of real number showed good electrical impedence properties.

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The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Expression of a Bacillus subtilis Endoglucanase in Protease-Deficient Bacillus subtilis Strains

  • Yang, Mi-Jeong;Jung, Sun-Hwa;Shin, Eun-Sun;Kim, Jung-Ho;Yun, Han-Dae;Wong, Sui-Lam;Kim, Ho-On
    • Journal of Microbiology and Biotechnology
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    • v.14 no.2
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    • pp.430-434
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    • 2004
  • Three extracellular protease-deficient Bacillus subtilis strains were transformed with the plasmid pCK98 containing the endo-$\beta$-1,4-glucanase (Eng) gene of B. subtilis BSE616. The three transformants, B. subtilis DB104 (pCK98), WB600 (pCK98) and WB700 (pCK98), produced the same high level of enzyme activity and showed similar patterns of cell growth and enzyme production. When B. subtilis DB 104 (pCK98), a two-extracellular protease deficient strain, was cultured for 22 h, almost all the secreted enzyme was found to be in the completely cleaved form by both activity staining and Western blotting studies. B. subtilis WB600 (pCK98), a six-extracellular protease-deficient strain, produced a partially cleaved form in addition to the intact form of the enzyme, although the degree of internal cleavage of the enzyme was greatly reduced. With B. subtilis WB700 (pCK98), a seven-extracellular protease-deficient strain, almost all the enzyme was produced as the intact uncleaved form. This study illustrates that a role of the V pr protease is to degrade foreign proteins produced in B. subtilis and WB700 is a suitable expression system for producing the intact form of the Eng and other foreign proteins that may lose at least part of their efficacy due to internal proteolytic cleavage.

Impact of Elevated Carbon Dioxide, Temperature, and Drought on Potato Canopy Architecture and Change in Macronutrients (상승된 이산화탄소와 온도 그리고 한발 영향에 따른 감자의 군락 형태와 무기영양 변화)

  • Lee, Yun-Ho;Cho, Hyeoun-Suk;Kim, Jun-Hwan;Sang, Wan-Gyu;Shin, Pyong;Baek, Jae-Kyeong;Seo, Myung-Chul
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.63 no.2
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    • pp.164-173
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    • 2018
  • Elevated atmospheric carbon dioxide concentration ($CO_2$) is a major component of climate change, and this increase can be expected to continue into the crop and food security in the future. In this study, Soil-Plant-Atmosphere-Research (SPAR) chambers were used to examine the effect of elevated $CO_2$, temperature, and drought on the canopy architecture and concentration of macronutrients in potatoes (Solanum tuberosum L.). Drought stress treatments were imposed on potato plants 40 days after emergence. Under AT+2.8C700 (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$), at maximum leaf area, elevated $CO_2$, and no drought stress, a significant increase was observed in both the aboveground biomass and tuber, and for the developmental stage. Even though $CO_2$ and temperature had increased, AT+2.8C700DS (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$ under drought stress) under drought stress showed that the leaf area index (LAI) and dry weight were reduced by drought stress. At maturity, potatoes grown under $CO_2$ enrichment and no drought stress exhibited significantly lower concentrations of N and P in their leaves, and of N, P, and K in tubers under AT+2.8C700. In contrast, elevated $CO_2$ and drought stress tended to increase the tuber Mg concentration under AT+2.8C700DS. Plants grown in AT+2.8C700 had lower protein contents than plants grown under ATC450 (30-year average temperature at $400{\mu}mol\;mol^{-1}$ of $CO_2$). However, plants grown under AT+2.8C700 showed higher tuber bulking than those grown under AT+2.8C700DS. These findings suggest that the increase in $CO_2$ concentrations and drought events in the future are likely to decrease the macronutrients and protein concentrations in potatoes, which are important for the human diet.

Effects of Heavy Metal Compounds (As, Cr, and Se) on the Development of Drosophila melanogasier (중금속화합물(As, Cr, Se)이 초파리 발생계에 미치는 영향)

  • 김기원;정연태;박승택;김정중
    • The Korean Journal of Zoology
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    • v.30 no.2
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    • pp.99-106
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    • 1987
  • It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

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Regulation of Cumulus Expansion of Porcine Cumulus-Oocyte Complexes in vitro: Involvement of cAMP and Calcium (돼지 난구세포의 분산조절에 관한 연구 : cAMP와 Calcium의 작용)

  • 권혁방;이원교;김남중;김문규;나철호
    • The Korean Journal of Zoology
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    • v.30 no.2
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    • pp.107-116
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    • 1987
  • It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

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