• Title/Summary/Keyword: 가돌리늄

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Direct determination of gadolinium in urania-gadolinia nuclear fuels by inductively coupled plasma atomic emission spectrometry (유도결합플라스마 원자방출분광법을 이용한 UO2-Gd2O3 핵연료 중 가돌리늄 분석)

  • Choi, Kwang-Soon;Suh, Moo-Yul;Lee, Chang-Heon;Han, Sun-Ho;Jee, Kwang-Yong
    • Analytical Science and Technology
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    • v.20 no.2
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    • pp.131-137
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    • 2007
  • The urania-gadolinia fuels were dissolved with nitric acid. The analytical conditions of ICP-AES for the direct determinations of gadolinium in the uranium matrices without separation process were investigated. Based on the effect of uranium on gadolinium intensity, the best wavelength for gadolinium was 336.223 nm. The relative deviation of two methods, direct and indirect measurements with anion exchange chromatography, was less than 5 %. Therefore it was possible for this procedure directly to measure 5~10 wt.% of gadolinium in urania-gadolinia fuels without separation by ICP-AES.

On the Accurate Determination of Curie Temperature of Bulk Gadolinium (큐리온도 근방에서의 전기적, 자기적 성질변화를 이용한 강자성 가돌리늄의 큐리온도의 결정)

  • 이일수
    • Journal of the Korean Vacuum Society
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    • v.4 no.3
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    • pp.283-286
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    • 1995
  • 자화도와 비저항의 온도에 따른 변화를 측정함으로써 덩치 가돌리늄의 큐리온도를 정확히 결정하였다. 이 두 물리량은 큐리온도에서 비정상적인 특이성을 보여준다. 이들의 특이성에서 결정된 큐리온도의 값은 서로 1도 이내에서 잘 일치함을 보여주었다.

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The Shift of Cuire Temperature in Ferromagnetic Gadolinium Films (강자성 가돌리늄 박막의 큐리 온도의 이동)

  • 이일수;추교진;이의완;이상윤;이종용;김양수;김동락;이형철
    • Journal of the Korean Vacuum Society
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    • v.3 no.3
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    • pp.305-308
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    • 1994
  • 가돌리늄 박막의 큐리온도를 자기화의 온도에 따른 변화를 측정함으로써 결정하였다. 박막의 큐 리돈도는 bulkrP의 큐리온도보다 낮아지며 이 박막에서의 큐리온도의 이동은 두께가얇아 질수록 커진다 는 것이 관측되었다. 이실험결과를 유한축적 이론의 관점에서 분석한 결과 전이온도의 이동에 관련된 지수 λ는 0.82$\pm$0.13로서 이론적인 값의 1.48과 상치한다는 사실이 발견되었다. 이러한 유한계의 실험치 와 유한축척이론과 파이는 여러 유한계에서 관측되었다.

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The increase of blood vessels using a signal during the image acquisition phase T1 shortening effect (위상영상 획득 시 T1 shortening effect를 이용한 혈관의 신호 증가에 관한 연구)

  • Lee, Ho-Beom;Choi, Kwan-Woo;Son, Soon-Yong;Min, Jung-Whan;Lee, Jong-Seok;Yoo, Beong-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4704-4710
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    • 2015
  • The purpose of this study is to obtain a useful diagnostic image by increasing the signal strength of the peripheral artery, was to use a T1 shortening effect of gadolinium contrast agents to improve the disadvantages of the phase image. From october to december 2014 thirty patients were underwent the MRI scanning, except for heart disease. Research method was evaluated comparing the image after gadolinium contrast MR image acquisition step before evaluating the difference between the signal intensity for T1 shortening effect. In frontal lobe 19.45%, temporal lobe 23.09%, occipital lobe 25.45%, parietal lobe 18.82%, cerebellum 20.93% after peripheral arterial signal strength results of gadolinium contrast agent injection was increased significantly after injection of gadolinium both statistically significant. After injecting a contrast agent gadolinium in SWI by increasing the signal strength of the T1 shortening effect can be obtained when using the phase image to give a useful image in diagnosis and treatment.

Usefulness of contrast agent involving high gadolium content for myocardial viability assessment (심근생존능검사 시 가돌리늄 함유량이 높은 조영제의 유용성)

  • Choi, Kwan-Woo;Son, Soon-Yong;Kim, Tae-Hyung;Han, Man-Seok;Lee, Ju-Hee;Min, Jung-Whan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1294-1300
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    • 2013
  • The purpose of this study is to increase contrast to noise ratio(CNR) in myocardial viability test by using contrast agent which highly content gadolinium(1mmol/mL) maximizing diagnostic value. This research method that four hundred four patients were underwent the MRI scanning two hundred eighty four of them were injected commercial contrast media which have 0.5mmol/L and the rest of them were injected new contrast media(gadobutrol) which have 1mmol/mL of molarity to study the contrast difference depending on the molarity of the contrast agent signal intensities of normal ventricle and left ventricle were measured to compare and evaluate signal to noise ratio(SNR) and CNR of the images. As result, 1mmol/mL contrast agent showed higher SNR by 25.13% in myocardium and 30.74% in left ventricle. CNR was proved to be better in 1mmol/mL contrast agent by 31.29%. The results above were all statistically meaningful. Therefore, contrast agent contenting more gadolinium which was 1mmol/mL in this study, could more effectively shorten T1 relaxation time, increase the signal intensity and at the same time maximize CNR and diagnostic value. This study firstly report the usefulness of 1mmol/mL contrast agent in patients allegedly suffering cardiac diseases and it is considered to increase diagnostic value.

Demonstrative Experiments on the Magnetocaloric Effect of Gadolinium (가돌리늄의 자기열량효과에 대한 실증실험)

  • 이종석
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.4
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    • pp.383-389
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    • 2004
  • Magnetic refrigeration is based on the magnetocaloric effect (MCE) - the ability of some materials to heat up when magnetized and cool down when removed from the magnetic field. The available techniques for studying the MCE we: (1) direct measurements by monitoring the change in the material's temperature during the application or removal of the magnetic field; and (2) indirect calculations from the experimental data of magnetization and/or specific heat as a function of the temperature and magnetic field. The MCE of gadolinium (Gd) has been demonstrated by direct measurements of temperature change, and isothermal magnetic entropy changes and adiabatic temperature changes have been calculated.

On the thickness dependence of electrical and magnetic characteristics near the critical point in gadolinium films (강자성 가돌리늄박막의 큐리온도근방에서 두께에 따른 전기적 자기적 특성변화)

  • Rhee, Ilsu;Ha, Dong-Han
    • Korean Journal of Materials Research
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    • v.5 no.3
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    • pp.275-279
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    • 1995
  • 가돌리늄박막의 큐리온도를 비저항의 온도에 따른 변화를 측정함으로써 결정하였다. 이비저항 실험치에서 구한 큐리온도의 값은 기존의 자화도에서 구한 큐리 온도값과 잘 일치함을 보여준다. 또한 박막의 큐리온도 실험값들은 얇은 박막일수록 큐리온도가 낮아지는 두께에 따른 변화를 잘 보여주고 있다. 유한 축척이론에 의한 분석에서 임계지수 $\lambda$ 는 0.82 $\pm$ 0.15가 나왔으며 이 값은 이론치인 1.48과 일치하지 않는다. 이 사실은 다른 많은 실험에서 확인한 바와 일치하고 있다.

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