Guidance, Navigation, and Control System Design in a Mass Reduction Exercise

Early Orion GN&C system designs optimized for robustness, simplicity, and utilization of commercially available components. During the System Definition Review (SDR), all subsystems on Orion were asked to re-optimize with component mass and steady state power as primary design metrics. The objective was to create a mass reserve in the Orion point of departure vehicle design prior to beginning the PDR analysis cycle. The Orion GN&C subsystem team transitioned from a philosophy of absolute 2 fault tolerance for crew safety and 1 fault tolerance for mission success to an approach of 1 fault tolerance for crew safety and risk based redundancy to meet probability allocations of loss of mission and loss of crew. This paper will discuss the analyses, rationale, and end results of this activity regarding Orion navigation sensor hardware, control effectors, and trajectory design

Study of Real-Time Spatial and Temporal Behavior of Bacterial Biofilms Using 2D Impedance Spectroscopy

The study of biofilms and their effect on disease treatment, prevention, and cures has been increasing in importance in recent years. Bacterial biofilms are colony formations developed by bacteria that allow them to anchor onto a surface and survive hostile environments. The formation of harmful bacteria biofilms on some surfaces can be troublesome, particularly in the case of medical implants. The continuing rise of antibiotic-resistant bacteria over the past decade had escalated the need to study and understand biofilms. This thesis presents the design of a multi-channel impedance spectroscopy instrument to allow 2D spatial and temporal evaluation of biofilm growth. The custom-designed circuits allow measurement updates once per second on the entire set of impedance sensors. The distance between the neighboring sensors is 220 micrometers, allowing realtime observation of biofilm growth. The initial results show that the proposed 2D impedance spectroscopy tool provides the needed accuracy to predict the existence of bacteria biofilm at a given sensor location. The initial results were validated using optical images with fluorescent staining

Map of the Welland Canal including the store house and waste weir no.1 drawn by Shamus A. Begly

Map of the Welland Canal including the store house and waste weir no.1 drawn by Shamus A. Begly of Public Works, n.d

Lettre de R. J. Begly à M. O’sullivan

1 pag

Lettre de R. James Begly à M. O’sullivan

1 pag