@article{du_yousefian_horn_muller_2020, title={Evaluation of Structural Anisotropy in a Porous Titanium Medium Mimicking Trabecular Bone Structure Using Mode-Converted Ultrasonic Scattering}, volume={67}, ISSN={["1525-8955"]}, DOI={10.1109/TUFFC.2019.2963162}, abstractNote={The mode-converted (longitudinal to transverse, L-T) ultrasonic scattering method was utilized to characterize the structural anisotropy of a phantom mimicking the structural properties of trabecular bone. The sample was fabricated using metal additive manufacturing from high-resolution computed tomography (CT) images of a sample of trabecular horse bone with strong anisotropy. Two focused transducers were used to perform the L-T ultrasonic measurements. A normal incidence transducer was used to transmit longitudinal ultrasonic waves into the sample, while the scattered transverse signals were received by an oblique incidence transducer. At multiple locations on the sample, four L-T measurements were performed by collecting ultrasonic scattering from four directions. The amplitude of the root mean square (rms) of the collected ultrasonic scattering signals was calculated for each L-T measurement. The ratios of rms amplitudes for L-T measurements in different directions were calculated to characterize the anisotropy of sample. The results show that the amplitude of L-T converted scattering is highly dependent on the direction of microstructural anisotropy. A strong anisotropy of the microstructure was observed, which coincides with simulation results previously published on the same structure as well as with the anisotropy estimated from the CT images. These results suggest the potential of mode-converted ultrasonic scattering methods to assess the anisotropy of materials with porous, complex structures, including trabecular bone.}, number={5}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Du, Hualong and Yousefian, Omid and Horn, Timothy and Muller, Marie}, year={2020}, month={May}, pages={1017–1024} }
 @article{du_mohanty_mullera_2017, title={Microstructural characterization of trabecular bone using ultrasonic backscattering and diffusion parameters}, volume={141}, ISSN={["1520-8524"]}, DOI={10.1121/1.4982824}, abstractNote={Finite differences time domain methods were utilized to simulate ultrasound propagation and scattering in anisotropic trabecular bone structures obtained from high resolution Computed Tomography (CT). The backscattered signals were collected and the incoherent contribution was extracted. The diffusion constant was calculated for propagations along and across the main direction of anisotropy, and was used to characterize the anisotropy of the trabecular microstructures. In anisotropic structures, the diffusion constant was significantly different in both directions, and the anisotropy of the diffusion constant was strongly correlated to the structural anisotropy measured on the CT images. These results indicate that metrics based on diffusion can be used to quantify the anisotropy of complex structures such as trabecular bone.}, number={5}, journal={JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA}, author={Du, Hualong and Mohanty, Kaustav and Mullera, Marie}, year={2017}, month={May}, pages={EL445–EL451} }
 @article{li_song_ni_wang_liu_du_2015, title={Grain size evaluation of structural materials in nuclear power plant using a thickness independent ultrasonic method}, volume={351}, journal={Nuclear Instruments & Methods in Physics Research. Section B, Beam Interactions With Materials and Atoms}, author={Li, X. B. and Song, Y. F. and Ni, P. J. and Wang, Z. and Liu, F. and Du, H. L.}, year={2015}, pages={16–22} }