- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Fill Factor Loss in Fielded Photovoltaic Modules Due to Metallization Failures, Characterized by Luminescence and Thermal Imaging
摘要： During irradiation UO2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of both porosity and elastic properties in high burnup UO2 pellet can be investigated via high frequency acoustic microscopy. For this purpose ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A UO2 pellet with a burnup of 67 GWd/tU was characterized using the acoustic microscope installed in the hot cells of the JRC-ITU at a 90 MHz frequency, with methanol as coupling liquid. VR was measured at different radial positions. A good agreement was found, when comparing the porosity values obtained via acoustic microscopy with those determined using SEM image analysis, especially in the areas close to the centre. In addition, Young’s modulus was calculated and its radial pro?le was correlated to the corresponding burnup pro?le and to the hardness radial pro?le data obtained by Vickers micro-indentation
关键词： Nuclear fuels,piezoelectric devices,Vickers microhardness,Young’s modulus,nuclear power
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - In-situ Microscopy Characterization of Cu(In,Ga)Se <sub/>2</sub> Potential-Induced Degradation
摘要： During irradiation UO2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of both porosity and elastic properties in high burnup UO2 pellet can be investigated via high frequency acoustic microscopy. For this purpose ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A UO2 pellet with a burnup of 67 GWd/tU was characterized using the acoustic microscope installed in the hot cells of the JRC-ITU at a 90 MHz frequency, with methanol as coupling liquid. VR was measured at different radial positions. A good agreement was found, when comparing the porosity values obtained via acoustic microscopy with those determined using SEM image analysis, especially in the areas close to the centre. In addition, Young’s modulus was calculated and its radial pro?le was correlated to the corresponding burnup pro?le and to the hardness radial pro?le data obtained by Vickers micro-indentation
关键词： Nuclear fuels,piezoelectric devices,Vickers microhardness,Young’s modulus,nuclear power
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Rough and Straightforward Estimation of the Mismatching Loss by Partial Shading of the PV Modules Installed on an Urban Area or Car-Roof
摘要： During irradiation UO2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of both porosity and elastic properties in high burnup UO2 pellet can be investigated via high frequency acoustic microscopy. For this purpose ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A UO2 pellet with a burnup of 67 GWd/tU was characterized using the acoustic microscope installed in the hot cells of the JRC-ITU at a 90 MHz frequency, with methanol as coupling liquid. VR was measured at different radial positions. A good agreement was found, when comparing the porosity values obtained via acoustic microscopy with those determined using SEM image analysis, especially in the areas close to the centre. In addition, Young’s modulus was calculated and its radial pro?le was correlated to the corresponding burnup pro?le and to the hardness radial pro?le data obtained by Vickers micro-indentation
关键词： Nuclear fuels,piezoelectric devices,Vickers microhardness,Young’s modulus,nuclear power
更新于2025-09-19 17:13:59
-
Laser energy density dependence of performance in additive/subtractive hybrid manufacturing of 316L stainless steel
摘要： An enormous amount of research effort goes into the manufacturing process for additive manufacturing (AM) or subtractive manufacturing (SM) process for property microstructure. Moreover, additive/subtractive hybrid manufacturing (ASHM), which combines additive and subtractive processes in a single machine, has provided an important opportunity to increase the high percentage of stock utilization and produce complex functional components. However, the system comprehensive investigation and the study of ASHM-manufactured parts by various process parameters have rarely been reported. The present paper depicted the effect of laser energy density (ψ) on the phase change, density, microstructure, Vickers hardness, and tensile testing within the ASHM specimens. It was observed that the highest Vickers microhardness, the largest tensile strength, and the attendant ductility were gained at ψ =222 J/mm3, the most excellent value, which was put down to the high density and relatively fine grains. The results of this study have a better knowledge of the ASHM method to produce a high surface state and mechanical behavior 316L SS component by governing laser energy density (ψ).
关键词： Additive/subtractive hybrid manufacturing,Laser energy density,Microstructure,Densification,Vickers microhardness,Tensile properties
更新于2025-09-16 10:30:52
-
Comparison of theoretical and experimental microhardness of tetrahedral binary Zn1-xErxO semiconductor polycrystalline nanoparticles
摘要： polycrystalline nanoparticles with various compositions were prepared using sol–gel techniques, for which zinc acetate dihydrate and erbium 2–4 pentanedionate are used as precursors. Nanoparticles were pressed under a pressure of tons for min into disk-shaped compacts with 2 mm thicknesses and 10 mm diameters. The pressed samples were annealed at 400 °C for min. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Vickers microhardness analyses of the produced Er-doped bulk nanomaterials were performed. Specifically, in this study we focused on the analysis of their mechanical properties. Undoped and Er-doped bulk samples were investigated according to Meyer's law; the proportional sample resistance (PSR), elastic/plastic deformation (EPD), and indentation-induced cracking (IIC) models; and the Hays–Kendal (HK) approach. As a result, the IIC model was more suitable to determine the micromechanical properties and the reverse indentation size effect (RISE) behavior of Er-doped semiconductors.
关键词： Vickers microhardness,Sol–gel,IIC model,RISE,ZnO,Er doping
更新于2025-09-10 09:29:36