Discrete particle simulation of particulate systems: A review of major applications and findings

Preface Acknowledgments 1. Introduction 2. Dispersion principles 3. Unbounded isotropic and anisotropic media 4. Reflection and refraction 5. Oblique incidence 6. Waves in plates 7. Surface and subsurface waves 8. Finite element method for guided wave mechanics 9. The semi-analytical finite element method (SAFE) 10. Guided waves in hollow cylinders 11. Circumferential guided waves 12. Guided waves in layered structures 13. Source influence on guided wave excitation 14. Horizontal shear 15. Guided waves in anisotropic media 16. Guided wave phased arrays in piping 17. Guided waves in viscoelastic media 18. Ultrasonic vibrations 19. Guided wave array transducers 20. Introduction to guided wave nonlinear methods 21. Guided wave imaging methods Appendix A: ultrasonic nondestructive testing principles, analysis and display technology Appendix B: basic formulas and concepts in the theory of elasticity Appendix C: physically based signal processing concepts for guided waves Appendix D: guided wave mode and frequency selection tips.

Ultrasonic Guided Waves in Solid Media

O.B. thanks the European Commission (Marie Curie CIG) and Ministerio de Ciencia e Innovacion, Spain (Juan de la Cierva Fellowship). G.J.L.B. thanks his generous sources of funding: Royal Society, FCT Portugal (FCT Investigator), European Commission (Marie Curie CIG), and the EPSRC. G.J.L.B. is a Royal Society University Research Fellow. The authors thank Paula Boutureira Regla and Francisco Pinteus da Cruz Lopes Bernardes for inspiration.

Advances in Chemical Protein Modification

Modeling wave propagation in damped waveguides of arbitrary cross-section

Plant tissue culture has become one of the fundamental tools of plant science research. It is extensively employed in the production, conservation and improvement of plant resources. The presence of somaclonal variation in populations derived from tissue culture is affecting the use of tissue culture negatively and has remained a major problem. Conversely, it is a source of new desirable clones/variants with better agronomic traits. In this review, we summarize the possible causes, detection methods and desirability of variants. Somaclonal variation is one of the most researched and reviewed topics. Hence, we restricted ourselves to outlining various examples which may be used as important references for researchers who intend to identify and/or characterize somaclonal variants while using tissue culture for research and production. Emphasis is placed on the negative effects of somaclonal variation. However, this review also includes examples of some useful variants generated as a result of somaclonal variation.

Somaclonal variation in plants: causes and detection methods

Guided wave dispersion curves for a bar with an arbitrary cross-section, a rod and rail example

Multiple reflections of Lamb waves at a delamination.

Wave structure analysis of guided waves in a bar with an arbitrary cross-section.

A New Method for Post‐Synthesis Coating of Zirconia on the Mesopore Walls of SBA‐15 Without Pore Blocking

Guided wave techniques are expected to become an effective means for rapid, long-range inspection of pipes. Such techniques still have many practical difficulties in application, however, due to the complex characteristics of guided waves such as dispersion and their multimodal nature. A defect imaging technique is developed in this study to overcome the complexities of guided wave inspection. Received signals are separated into single-mode waveforms with a mode extraction technique and then spatial waveforms on the pipe surface at an arbitrary time are reconstructed. The predicted waveforms can provide a defect image at the moment when an incident wave arrives at a defect region, which is based on a time-reversal technique. This defect imaging technique is experimentally verified using eight signals detected at eight different circumferential positions. Images of artificial defects are obtained with one-hole and two-hole test pipes, and increasing the frequency of incident waves increases the resolution of the images. Holes and pipe ends are recognizable in the images, but the reconstructed images contain some errors in the area behind the defects where guided waves do not propagate or do not reflect back to the receiving transducers.

/pdf/defect-imaging-with-guided-waves-in-a-pipe-3253n7bqad.pdf

Takahiro Hayashi

Papers

Guided wave dispersion curves for a bar with an arbitrary cross-section, a rod and rail example

Multiple reflections of Lamb waves at a delamination.

Wave structure analysis of guided waves in a bar with an arbitrary cross-section.

A New Method for Post‐Synthesis Coating of Zirconia on the Mesopore Walls of SBA‐15 Without Pore Blocking

Defect imaging with guided waves in a pipe