Engineering Commons^™

Optical Properties Of Semiconducting Boron Carbide For Neutron Detection Applications, Ravi B. Billa

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Solid state neutron detection devices based on semiconducting boron carbide have the potential for nearly ideal neutron detection effciency for thermal neutrons. The present work is focused on characterizing optical properties of this semiconducting boron carbide material as a step in further development of the material for neutron detection and other applications.

Semiconducting boron carbide films were grown on silicon substrates using plasma enhanced chemical vapor deposition and their optical properties were characterized using variable angle spectroscopic ellipsometry over a wide spectral range, from mid-infrared to vacuum-ultraviolet wavelengths. The effects of deposition substrate temperature and of post-deposition heat treatments on …

Modeling And Simulation Of Interactions Between Blast Waves And Structures For Blast Wave Mitigation, Wen Peng

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Explosions occur in military conflicts as well as in various industrial applications. Air blast waves generated by large explosions move outward with high velocity, pressure and temperature. The blast waves not only incapacitate military and civilian personnel, but also damages buildings, vehicles, and other properties. Hence, there has been extensive research on how to mitigate blast wave effects. Understanding the interactions between blast waves and structures is a very important step in the development of devices for blast wave mitigation. The objective of this dissertation is to explore the complicated physical problem of blast waves impacting structures. The structures comprise …

Towards Supervised Autonomous Task Completion Using An In Vivo Surgical Robot, Jason J. Dumpert

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Laparoscopy is a minimally invasive alternative to traditional abdominal surgery. Unlike traditional surgery, a laparoscopic procedure can be completed using small incisions. The use of these small incision results in reduced pain to the patient, shorter recovery times, and less trauma to skin, muscle and other tissues. However, these benefits to the patient are offset by the increased difficulty to the surgeon performing the procedure. These difficulties include reduced dexterity, reduced perception, and longer procedure times. The use of small in vivo robotic devices in minimally invasive surgery is one possible solution to these problems. The movement of these devices …

Development Of Guidelines For Deformable And Rigid Switch In Ls-Dyna Simulation, Ling Zhu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

LS-Dyna simulations have been widely used in research and design to reduce fiscal and time costs. In order to improve the simulation’s efficiency, the components which experience negligible deformations are usually modeled as rigid bodies. However, the use of rigid bodies is always restricted. Though the use of more rigid bodies can save computing resources for a particular simulation, less rigid bodies are preferred for building a model in order to broaden its applications. Meanwhile, if a simulation task has multiple events, the application of rigid bodies in the particular simulation is always minimized so that it can satisfy all …