题目：Endeavor for developing new approaches to evaluate materials performance in service
报告人：Ben Jar, Ph.D., P.Eng. Professor，Department of Mechanical Engineering, University of Alberta, Canada.
摘要：Mechanical property is one of the most important pieces of information for materials characterization, especially to evaluate their suitability for load-carrying applications. Although an extensive variety of standard methods are now available for establishing the relationship between mechanical properties and material performance, a pretty wide gap still exists for applying mechanical properties measured from coupon specimens to prediction of in-service performance. The main objective of my research is to develop new test methods to close this gap and to shorten the time for material evaluation in load-carrying applications.
This presentation will give examples from our recent studies on the needs of new test methods to evaluate material performance. The presentation will introduce two approaches in which coupon test results are directly used to evaluate material performance in service, of which one is for polyethylene (PE) and the other steel. The former is used to make gas and water pipes and the latter railway network. Although both types of materials are now widely used in their respective applications, the presentation will show that there are still needs of new methods to characterize their mechanical properties, not only to meet the application requirements but also to satisfy the academic curiosity. The presentation will also give a brief history about how I became interested in these areas and how I set the research goals to maintain interests from industries. The presentation will conclude by summarizing what we have learned from the studies and pointing out the future work that will benefit from research collaboration.
个人简介：加拿大机械工程师协会(CSME)会士，加拿大机械工程师协会年度最高学术荣誉G.H. Duggan奖得主。发表SCI期刊论文120篇，专业英文著作6部。是阿尔伯塔大学机械工程学院前研究生项目主任。
2.题目：Application of High Frequency Ultrasound in Dentistry
报告人：Lawrence H Le, PhD, MBA, Professor, Medical Physics, Graduate Coordinator，Radiology and Diagnostic Imaging, University of Alberta, Canada.
摘要：Intraoral ultrasonography uses high-frequency mechanical waves to study dento-periodontium. Besides the advantages of portability and cost-effectiveness, ultrasound technique has no ionizing radiation. Previous studies employed a single transducer or an array of transducer elements, and focused on enamel thickness and distance measurement. This study used a phased array system with a 128-element array transducer to image dento-periodontal tissues. We studied two porcine lower incisors from a 6-month-old piglet using 20-MHz ultrasound. The high-resolution ultrasonographs clearly showed the cross-sectional morphological images of the hard and soft tissues. The investigation used an integration of waveform analysis, travel-time calculation, and wavefield simulation to reveal the nature of the ultrasound data, which makes the study novel. With the assistance of time-distance radio-frequency records, we robustly justified the enamel-dentin interface, dentin-pulp interface, and the cemento-enamel junction. The alveolar crest level, the location of cemento-enamel junction, and the thickness of alveolar crest were measured from the images and compared favorably with those from the cone beam computed tomography with less than 10% difference. This preliminary and fundamental study has reinforced the conclusions from previous studies, that ultrasonography has great potential to become a non-invasive diagnostic imaging tool for quantitative assessment of periodontal structures and better delivery of oral care.
个人简介：美国医学物理学会、加拿大医学物理协会会士，为IEEE Access, Annals of Applied Acoustics, Medical Physics, Sensors, Ultrasonics等13个知名学术刊物的编辑和审稿人，复旦大学兼职教授。
