Non-invasive quantification of physiological processes with dynamic PET using blind deconvolution

Author name used in this publication: Daniel Pak-Kong LunAuthor name used in this publication: Dagan FengVersion of RecordPublishe

Synthesis, densification, and properties of high entropy ultra-high temperature ceramics

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On the expected number of facets for the convex hull of samples

This paper studies the convex hull of $d$-dimensional samples i.i.d. generated from spherically symmetric distributions. Specifically, we derive a complete integration formula for the expected facet number of the convex hull. This formula is with respect to the CDF of the radial distribution. As the number of samples approaches infinity, the integration formula enables us to obtain the asymptotic value of the expected facet number for three categories of spherically symmetric distributions. Additionally, the asymptotic result can be applied to estimating the sample complexity in order that the probability measure of the convex hull tends to one

Boro/carbothermal Reduction Co-Synthesis of Dual-Phase High-Entropy Boride-Carbide Ceramics

Dense, dual-phase (Cr,Hf,Nb,Ta,Ti,Zr)B2-(Cr,Hf,Nb,Ta,Ti,Zr)C ceramics were synthesized by boro/carbothermal reduction of oxides and densified by spark plasma sintering. The high-entropy carbide content was about 14.5 wt%. Grain growth was suppressed by the pinning effect of the two-phase ceramic, which resulted in average grain sizes of 2.7 ± 1.3 µm for the high-entropy boride phase and 1.6 ± 0.7 µm for the high-entropy carbide phase. Vickers hardness values increased from 25.2 ± 1.1 GPa for an indentation load of 9.81 N to 38.9 ± 2.5 GPa for an indentation load of 0.49 N due to the indentation size effect. Boro/carbothermal reduction is a facile process for the synthesis and densification of dual-phase high entropy boride-carbide ceramics with both different combinations of transition metals and different proportions of boride and carbide phases

Superhard Single-Phase (Ti,Cr)B2 Ceramics

A nominally pure and dense (Ti0.9Cr0.1)B2 ceramic was produced by spark plasma sintering of powders synthesized by boro/carbothermal reduction of oxides. The synthesized powders were a single phase and had an average particle of 0.4 ± 0.1 μm and an oxygen content of 1.2 wt%. Average Vickers hardness values of the resulting ceramics increased from 25.9 ± 0.8 GPa at a load of 9.81 N, to 46.3 ± 0.8 GPa at a load of 0.49 N. Compared to the nominally pure TiB2 ceramic obtained under the same processing conditions, the (Ti0.9Cr0.1)B2 ceramic had higher values under the same load due to the finer average grain size (2.4 ± 1.0 μm), higher relative density, and solid solution hardening. The results indicated that the Cr addition promoted densification, suppressed grain growth, and improved the hardness of TiB2 ceramics. This is the first report for dense and single-phase (Ti,Cr)B2 ceramics as superhard materials

Efficient blind image restoration using discrete periodic Radon transform

Author name used in this publication: Daniel P. K. LunAuthor name used in this publication: David Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe