Greg O'Bryan

In situ phase change characterization of PVDF thin films using Raman spectroscopy

A process for the design and optimization of a morphing aileron using flexible matrix composite (FMC) actuators is developed. Design requirements were based on the use of a morphing aileron with an existing medium size commercial transport aircraft limiting the planform to the existing conventional aileron. The design uses two sets of contracting FMC actuators operating independently to actuate the deformable aileron in both trailing edge up and down cases while matching coefficient of lift values of a conventional aileron. The design was optimized by developing a series of response models which were then used to understand the sensitivity to material, geometric and loading design variables while minimizing required force from the FMC actuators. Using a combination of response models and sequential quadratic programming algorithm, a design is chosen that matched the conventional ailerons performance at multiple flight conditions.

Final LDRD Report: Advanced Plastic Scintillators for Neutron Detection

This report summarizes the results of a one-year, feasibility-scale LDRD project that was conducted with the goal of developing new plastic scintillators capable of pulse shape discrimination (PSD) for neutron detection. Copolymers composed of matrix materials such as poly(methyl methacrylate) (PMMA) and blocks containing trans-stilbene (tSB) as the scintillator component were prepared and tested for gamma/neutron response. Block copolymer synthesis utilizing tSBMA proved unsuccessful so random copolymers containing up to 30% tSB were prepared. These copolymers were found to function as scintillators upon exposure to gamma radiation; however, they did not exhibit PSD when exposed to a neutron source. This project, while falling short of its ultimate goal, demonstrated the possible utility of single-component, undoped plastics as scintillators for applications that do not require PSD.