Publications by authors named "Gigax J"

Article Synopsis
  • The study focused on how adding 1 wt. lead (Pb) affects the plastic deformation and microstructure of pure copper (Cu) and Cu alloys, particularly at grain boundaries where Pb forms precipitates.
  • Various advanced techniques were used, including neutron diffraction and electron microscopy, to examine the behavior of these materials under stress at different scales.
  • Results showed that while the overall deformation responses were similar for both materials, the Cu-1Pb alloy had a higher dislocation density and the presence of lead significantly influenced local deformation, providing important insights for improving structural materials in engineering.
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The advent of nanotechnology has motivated a revolution in the development of miniaturized sensors. Such sensors can be used for radiation detection, temperature sensing, radio-frequency sensing, strain sensing, and more. At the nanoscale, integrating the materials of interest into sensing platforms can be a common issue.

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Amorphous metallic glasses (MGs) convert to crystalline solids upon annealing at a high temperature. Such a phase change, however, does not occur with the local melting caused by damage cascades introduced by ion irradiation, although the resulting thermal spikes can reach temperatures > 1000 K. This is because the quenching rate of the local melting zone is several orders of magnitude higher than the critical cooling rate for MG formation.

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In the quest of new materials that can withstand severe irradiation and mechanical extremes for advanced applications (e.g. fission & fusion reactors, space applications, etc.

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Small disks are often the specimen of choice for exposure in nuclear reactor environments, and this geometry invariably limits the types of mechanical testing that can be performed on the specimen. Recently, shear punch testing has been utilized to evaluate changes arising from neutron irradiation in test reactor environments on these small disk specimens. As part of a broader effort to link accelerated testing using ion irradiation and conventional neutron irradiation techniques, a novel microshear specimen geometry was developed for use with heavy-ion irradiated specimens.

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Beyond the current commercial materials, refining the grain size is among the proposed strategies to manufacture resilient materials for industrial applications demanding high resistance to severe environments. Here, large strain machining (LSM) was used to manufacture nanostructured HT-9 steel with enhanced thermal stability, mechanical properties, and ductility. Nanocrystalline HT-9 steels with different aspect rations are achieved.

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Measurement modalities in Bragg coherent diffraction imaging (BCDI) rely on finding a signal from a single nanoscale crystal object which satisfies the Bragg condition among a large number of arbitrarily oriented nanocrystals. However, even when the signal from a single Bragg reflection with (hkl) Miller indices is found, the crystallographic axes on the retrieved three-dimensional (3D) image of the crystal remain unknown, and thus localizing in reciprocal space other Bragg reflections becomes time-consuming or requires good knowledge of the orientation of the crystal. Here, the commissioning of a movable double-bounce Si (111) monochromator at the 34-ID-C endstation of the Advanced Photon Source is reported, which aims at delivering multi-reflection BCDI as a standard tool in a single beamline instrument.

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As one candidate alloy for future Generation IV and fusion reactors, a dual-phase 12Cr oxide-dispersion-strengthened (ODS) alloy was developed for high temperature strength and creep resistance and has shown good void swelling resistance under high damage self-ion irradiation at high temperature. However, the effect of helium and its combination with radiation damage on oxide dispersoid stability needs to be investigated. In this study, 120 keV energy helium was preloaded into specimens at doses of 1 × 10 and 1 × 10 ions/cm at room temperature, and 3.

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This study investigates the microstructural evolution and mechanical response of sputter-deposited amorphous silicon oxycarbide (SiOC)/crystalline Fe nanolaminates, a single layer SiOC film, and a single layer Fe film subjected to ion implantation at room temperature to obtain a maximum He concentration of 5 at. %. X-ray diffraction and transmission electron microscopy indicated no evidence of implantation-induced phase transformation or layer breakdown in the nanolaminates.

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Article Synopsis
  • The management of radiation defects and helium atoms is crucial for the structural integrity of materials used in fission reactors.
  • A study was conducted on helium bubble formation in amorphous silicon oxycarbide (SiOC) and crystalline iron (Fe) composites to understand how their interface affects radiation tolerance.
  • Results showed no helium bubbles in SiOC layers and reduced bubble density in Fe layers when combined with SiOC, indicating that the amorphous/crystalline interface helps to mitigate helium defects during implantation.
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We studied the effects ion beam irradiation on carbon nanotube (CNT) yarns. CNT yarn was fabricated by drawing and spinning CNT sheets from a vertically aligned CNT forest. The yarn was irradiated by 2.

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Despite recent interest in amorphous ceramics for a variety of nuclear applications, many details of their structure before and after irradiation/implantation remain unknown. Here we investigated the short-range order of amorphous silicon oxycarbide (SiOC) alloys by using the atomic pair-distribution function (PDF) obtained from electron diffraction. The PDF results show that the structure of SiOC alloys are nearly unchanged after both irradiation up to 30 dpa and He implantation up to 113 at%.

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This study investigated effects of stocking rate on cattle performance, quality and quantity of corn residue, and impact of residue removal on grain yield for 5 yr at the University of Nebraska - Lincoln West Central Water Resources Field Laboratory near Brule, NE. Four removal treatments-1) no removal (control), 2) grazing at 2.5 animal unit month (AUM)/ha, 3) grazing at 5.

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The characteristics of eosinophilic ureteritis and idiopathic segmental ureteritis are sufficiently overlapping and so uncommonly reported as to raise a nosological issue. In an attempt to address that question, we compared 2 new cases and 8 previous reports of eosinophilic ureteritis with a series of 21 idiopathic segmental ureteritis patients. One of our patients also had renal pelvic involvement, while 1 is the youngest (3 years old) patient reported and the first instance of bilateral eosinophilic ureteritis.

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