What is the fine-grained topic of the following text: Some of the scientific questions he is working to answer include understanding how materials fail due to the combined mechanical and chemical effects, what are the atomistic mechanisms governing the brittle to ductile transition in crystals, why the introduction of nano-sized twins can significantly increase the rate sensitivity of nano-crystals, and how domain structures affect the reliability of ferroelectric ceramics and thin films. Only return the topic.
Scientific research on the behavior and properties of materials.