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Luminescence characteristics of Dy^(3+) doped Gd_2O_3-CaO-SiO_2-B_2O_3 scintillating glasses

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journal of Rare Earths 2016年第6期34卷 583-589页

作者： j.Kaewkhao N.Wantana S.Kaewjaeng S.Kothan h.j.kim Center of Excellence in Glass Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Department of Radiologic Technology Faculty of Associated Medical Sciences Chiang Mai University Department of Physics Kyungpook National University

Glasses were prepared from the compositions of 25Gd_2O_3-10 CaO-10 SiO_2-（55–x）B_2O_3-xDy_2O_3（where x is 0.0 mol.%–1.0 mol.%） by the conventional melt-quenching technique at 1400 oC. The results demonstrated the increase in the glass density with respect to the increase in the doping concentrations of Dy_2O_3. Nine absorption bands were observed. The emission spectra of the developed glass showed two strong peaks at 577 nm（~4F_（9/2）→~6h_（13/2）） and 482 nm（~4F_（9/2）→~6h_（15/2））. The highest emission intensity was observed from the developed glass prepared at 0.4 mol.% of Dy_2O_3, as the efficient energy transfer took place from Gd^（3＋） to Dy^（3＋）. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest intensity observed from the glass quenched at 0.45 mol.% of Dy_2O_3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.

关键词： amorphous materials glasses oxides optical properties luminescence rare earths

high-performance and Multi-functional Control of Transformerless Single-phase Smart Inverter for Grid-connected PV System

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journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1386-1394页

作者： Kamran Zeb Saif Ul Islam Waqar Uddin Imran Khan Muhammad Ishfaq Tiago Davi Curi Busarello h.j.kim Department of Electrical Engineering Pusan National University School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of Control Automation and Computing EngineeringFederal University of Santa Catarina Blumenau

highly reliable and flexible control is required for distributed generation(DG) to efficiently connect to the *** inverters play a key role in the control and integration of DG into the power grid and provide advanced functionalities. In this paper, an energy-based single-phase voltage-source smart inverter(SPV-SSI) of 5 k VA is designed and analyzed in detail. SPV-SSI is capable of supplying the power to local load and the utility load up to the rated capacity of the inverter, injecting the power into the grid, storing the energy in lead-acid battery bank, controlling the voltage at the point of common coupling(PCC) during voltage sags or faults, and making decisions on real-time pricing information obtained from the utility grid through advanced metering. The complete design of smart inverter in dq frame, bi-directional DC-DC buck-boost converter, IEEE standard 1547 based islanding and recloser, and static synchronous compensator(STATCOM) functionalities is presented in this paper. Moreover, adaptive controllers, i. e., fuzzy proportional-integral(F-PI) controller and fuzzy-sliding mode controller(F-SMC) are designed. The performances of F-PI controller and F-SMC are superior, stable, and robust compared with those of conventionally tuned PI controllers for voltage control loop(islanded mode) and current control loop(grid-connected mode).

关键词： Distributed generation(DG) inverter convert-er fuzzy-sliding mode controller(F-SMC) fuzzy proportionalintegral(F-PI)controller

Gamma-ray and neutron shielding efficiency of Pb-free gadolinium-based glasses

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Nuclear Science and Techniques 2016年第4期27卷 206-213页

作者： V.P.Singh N.M.Badiger S.Kothan S.Kaewjaeng T.Korkut h.j.kim j.Kaewkhao Department of Physics Karnatak University Department of Radiologic Technology Faculty of Associated Medical SciencesChiang Mai University Department of Nuclear Energy Engineering Faculty of Engineering Sinop University Department of Physics Kyungpook National University Center of Excellence in Glass Technology and Materials Science Nakhon Pathom Rajabhat University

The radiation shielding efficiency of material depends upon photon attenuation, exposure buildup factors and neutron removal capacity. A newly developed Pb-free gadolinium-based glasses in compositions(80-x) B_2O_3-10 Si O_2-10 Ca O-x Gd_2O_3(where x = 15, 20, 25, 30 and35 mol%) had completely been investigated for their shielding efficiency with Geant4 simulation for mass attenuation coefficients and neutron total macroscopic cross section and by calculating exposure buildup *** exposure buildup factors for photon energy from 0.015 to 15 Me V had been calculated up to 40 mean free paths using five factors geometric progression method. The mass attenuation coefficients of the Pb-free glasses were simulated for energies from 223 to 2614 ke V and compared with the possible available experimental results. The neutron shielding efficiency of these glasses was discussed by calculating neutron total macroscopic cross section for energies from 1 e V to 14.1 Me V. Present investigations are found to be very useful for applications in nuclear engineering.

关键词：无铅玻璃屏蔽效率中子质量衰减系数 γ射线光子能量截面计算 Geant4

胰腺神经内分泌肿瘤门静脉期CT肿瘤/胰腺实质增强比的预后价值

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国际医学放射学杂志 2023年第3期 369-370页

作者： h.j.Park h.j.kim j.h.kim S.Y.kim S.h.Choi j.h.Byun 程欣

摘要目的评估胰腺神经内分泌肿瘤（PanNEN）病人门静脉期CT肿瘤-胰腺实质增强比（CER on PVP）在预后方面的价值，并将其与当前常见的分级和分期系统进行比较。方

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Comparative study of Sm^(3+) ions doped phosphate based oxide and oxy-fluoride glasses for solid state lighting applications

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journal of Rare Earths 2019年第4期37卷 374-382页

作者： M.Shoaib G.Rooh R.Rajaramakrishna N.Chanthima N.Kiwsakunkran h.j.kim j.Kaewkhao S.Tuscharoen Department of Physics Abdul Wali Khan University Center of Excellence in Class Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Physics Program Faculty of Science and TechnologyNakhon Pathom Rajabhat University Department of Physics Kyungpook National University

The physical and luminescent properties of Sm^(3+)-doped oxide and oxy-fluoride phosphate glasses were investigated. The glass samples with chemical composition of 69 P_2 O_5-10 BaO-10 ZnO-10 Gd_2 O_3-1 Sm_2 O_3 and 69 P_2 O_5-10 BaO-10 ZnO-10 GdF_3-1 Sm_2 O_3 were prepared by conventional melt quenching technique. The prepared glass samples were characterized with density, molar volume, refractive index,FTIR, UV-Vis-NIR, photo luminesce nce, radio luminescence, decay time profile and CIE diagram. The density and refractive index of the oxide glass have higher values as compared to the oxy-fluoride *** FTIR spectra show the reduction of O-h group in oxy-fluoride glass. The characteristic peaks of Sm^(3+)are observed at 360,372,402,438,419,473,944,1077,1227,1373,1474,1529 and 1585 nm in UV-VIS-NIR spectra. These peaks are related respectively to the transitions from ground state ~6 h_(5/2) to ~4 D_(3/2), ~6 P_(7/2),6 P3/2, ~4 I_(11/2), ~6 F_(11/2), ~6 F_(9/2), ~6 F_(7/2),~6 F_(5/2),~6 F_(3/2), ~6 h_(15/2) and ~6 F_(1/2) excited states. From photoluminescence and radio-luminesce nce it is observed that the oxy-fluoride glass samples show better emission intensity than the oxide glass. The judd-Ofelt theory(j-0 theory) was used to find j-O intensity Ω_λ(λ = 2,4 and 6)parameters and radiative properties such as transition probability, stimulated emission cross section and branching ratios for titled glasses. The trend observed in the j-O parameters is Ω_4 >Ω_2 >Ω_6. The transition probability,emission cross section and branching ratio have the highest values for the ~4 G_(5/2)→~6 h_(7/2)transition. The CIE coordinates of the prepared glass samples are positioned in the orange region and the CCT value is 3776.105 for oxide and oxyfluoride glass. The oxy-fluoride glass has shorter decay time as compared to the oxide glass and it is recorded to be 1.62 and 1.32 ms for oxide and oxy-fluoride respectively. According to the results obtained in this work, it is obvious t

关键词： Oxy-fluoride glass Photoluminescence judd-Ofelt theory CIE coordinates Rare earths

Optical and luminescence characteristics of Eu^(3+)-doped B_2O_3:SiO_2:Y_2O_3:CaO glasses for visible red laser and scintillation material applications

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journal of Rare Earths 2018年第5期36卷 482-491页

作者： Pabitra Aryal C.R.Kesavulu h.j.kim S.W.Lee Sang jun Kang j.Kaewkhao N.Chanthima B.Damdee Department of Physics Kyungpook National University College of Liberal Arts Semyung University Center of Excellence in Glass Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Physics Program Faculty of Science and TechnologyNakhon Pathom Rajabhat University

Europium（Eu^3＋） doped glasses of chemical compositions（55-x）B2O3：10 SiO2：25 Y2O3：10CaO：xEu2O3,where x denotes mol% and ranges 0≤ x ≤ 2.5, were synthesized by adopting conventional melt quenching technique, Physical properties like density, molar volume, polaron radius, inter-ionic distance and field strength of the glass samples were investigated to assess the impact of Eu2O3. Optical and luminescence properties of the glasses were characterized with optical absorption, photoluminescence,X-ray induced emission spectra, temperature dependence emission spectra and decay times. judd-Ofelt（jO） intensity parameters（Ωλ） of the glasses were evaluated based on the absorption spectrum of 0.5 mol%. jO parameters, calculated from absorption spectra with thermal corrections on oscillator strength, were used to evaluate radiative properties such as radiative transition probability（AR）,branching ratio（βR）, stimulated cross section emission（σ） and radiative lifetime（τR） for 5D0→7 Fj（j = 0,1,2,3 and 4） transitions. The decay rate of 5D0 fluorescent level for all the glass samples was single exponential. Lifetimes of the 5D0 level were decreased with increasing concentrations of Eu^3＋ions from 0.05 mol% to 2.5 mol% which might be due to energy transfer through cross-relaxation in the glasses. The chromaticity coordinates（x, y） were similar for all BSYCaEu glasses and were located at the red region of CIE 1931 color chromaticity diagram. hence, these results confirm that the Eu^3＋ doped BSYCaEu glasses could be useful for visible red lasers and glass scintillation applications.

关键词： BSYCaEu glasses judd-Ofeltintensity parameters Luminescence properties CIE color co-ordinates Glass scintillation Rare earths

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小截面有限流光管(LST)的研究

小截面有限流光管(LST)的研究

三叉神经痛:T2 VISTA和FLAIR VISTA联合成像评估

第8届全国核电子学与核探测技术学术年会

作者：万裕德 h.j.kim 中国原子能科学研究院 Oak Rigde National Laboratory

本文介绍阴极截面为6mm×6mm,阳极丝直径100μm,阴极截面为5mm×5mm的有限流光管的研究。

关键词：有限流光管工作气体

来源： cnki会议评论

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国际医学放射学杂志 2012年第1期 101-102页

作者： S.T.kim h.j.kim j.W.Choi h.j.kim P.jeon 夏艺 Department of Radiology and Center for Imaging Science Sungkyunkwan University School of MedicineSamsung Medical CenterSeoulKorea

目的采用T2 VISTA和FLAIR VISTA联合成像评估三叉神经痛(TN)病人的神经血管压迫(NVC)。方法回顾性研究2008年4月—2010年10月间行3TMR成像的连续

关键词：三叉神经痛 MRI 神经血管压迫微血管减压多平面重组

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.jeong S.W.Lee W.j.kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth