Many pathological processes cause marked changes in the mechanical properties of tissue. MR elastography (MRE) is a noninvasive MRI based technique for quantitatively assessing the mechanical properties of tissues in vivo. MRE is performed by using a vibration source to generate low frequency mechanical waves in tissue, imaging the propagating waves using a phase contrast MRI technique, and the...

The analyses of flagellar movement stimulated by Sir James Gray's (1955) photographic study of the movement of sea-urchin spermatozoa have used sine waves as a convenient mathematical model for the active bending waves of flagella. Machin (1958), following a suggestion of Pringle (1957), outlined an attractively simple model for the mechanical co-ordination of bending elements distributed along...

In this paper, we consider the problem of mechanical wave scattering from a spatially finite system into an infinite surrounding environment. The goal is to illuminate why spectrum undergoes peaks and dips (resonances) at specific locations how these connect vibrational properties scatterer. resonance are connected eigenvalues dimensional effective operator, H e f , corresponding developments p...

This study aimed at analyzing the impact of problem-based learning (PBL) in improving physics students’ conceptual understanding mechanical waves. used a quasiexperimental, pretest–post-test control group design with PBL instruction as teaching intervention. The participants this were 239 students from 19 secondary schools Western Uganda. We analyzed data SPSS v.23.0 using repeated two-way anal...