We have developed novel gold-silver alloy nanoshells as magnetic resonance imaging (MRI) dual T1 (positive) and T2 (negative) contrast agents as an alternative to typical gadolinium (Gd)-based contrast agents. Specifically, we have doped iron oxide nanoparticles with Gd ions and sequestered the ions within the core by coating the nanoparticles with an alloy of gold and silver. Thus, these nanop...

In situ X-ray diffraction was used to study the interactions of the PNNL G18 fuel cell sealing glasses with the oxides that form on candidate interconnect alloys and with the ebrite alloy. Experiments under 4% hydrogen and air at temperatures up to 1000 °C showed that both sealants react rapidly with alumina and chromia, but not with NiO. The crystallization of the high-CTE phase BaCrO4 was not...

The effects of strain rate and temperature on the dynamic behavior of Fe-based high temperature alloy was studied. The strain rates were 0.001-12,000 s(-1), at temperatures ranging from room temperature to 800 °C. A phenomenological constitutive model (Power-Law constitutive model) was proposed considering adiabatic temperature rise and accurate material thermal physical properties. During whic...

Chirality-controlled synthesis of single-walled carbon nanotubes (SWCNTs) is a prerequisite for their practical applications in electronic and optoelectronic devices. We report here a novel bimetallic CoPt catalyst for the selective growth of high quality SWCNTs with a narrow chirality distribution at relatively high temperatures of 800 °C and 850 °C using atmospheric pressure alcohol chemical ...

The steep thermal gradient and complicated cycle occur in the fabrication of Ti6Al4V alloy during laser solid forming (LSF). That leads to obvious anisotropic mechanical properties requires essential heat treatments improve its performance. In this work, different treatment strategies under vacuum condition were used study evolution microstructures produced by LSF. results show that transformat...

Surfactant-assisted mechanical milling has been used to produce discrete nanoparticles of both Nd-Fe-B and Sm-Co amenable for bottom-up production of nanostructured or nanocomposite permanent magnets. However, in Nd-Fe-B the comminution of the material proceeds by transgranular fracture, which influences both the morphology of the nanoparticles and the magnetic properties. This paper utilizes a...

This study uses a torsional split-Hopkinson bar to investigate the shear response and fracture characteristics of unweldable Al-Sc alloy during mechanical testing at shear strain rates of 800 s , 1500 s , 2200 s 1 and 2800 s 1 and temperatures of 150 C, 25 C and 300 C. The experimental results show that both the shear strain rate and the temperature have a significant effect on the shear proper...