Robotically Assembled Space Telescopes with Deployable Modules: Concepts and Design Methodologies

This thesis first presents a novel architecture for robotically assembled optical telescopes with apertures between 20 m and 100 m, that utilizes only currently available technology. In this architecture, the primary mirror consists of two layers: a reflective layer and a truss backplane layer. The reflective layer is divided into mirror modules, or groups of mirror segments and actuators. The truss backplane layer is divided into truss modules that fold compactly for launch and are deployed in space by the robot. In this thesis, the design methodology of the mirror modules and truss modules is detailed. The ability of the designed truss layer to maintain precision requirements in the presence of typical space environment loads is demonstrated. This architecture requires the deployment of many truss modules, and thus the deployment must be reliable despite errors introduced during manufacturing. In this thesis, a new simulation-based toolkit for estimating deployment reliability is described, including the experimental validation of the deployment simulation and the Monte Carlo-style method for repeating deployment simulations with different distributions of random fabrication errors to statistically estimate reliability. Using the toolkit, a set of reliability trade studies are then presented, revealing how different types of errors and design parameters affect reliability. Finally, the manufacturing tolerances and design modifications required to ensure high reliability are proposed. Even if all modules deploy successfully, fabrication errors will still be present and may affect the assembly process. In this thesis, a new simulation method is presented that can model the step-by-step assembly of flexible modules with errors. The method is used to reveal that overall shape errors grow with the number of connections, resulting in significantly decreased surface precision and large-scale deformations from the nominal backplane shape as the size of the backplane increases. The misalignment at each individual connection does not increase as the backplane increases, but can still be much larger than the applied manufacturing tolerances simply due to random combinations. A simple design for the interconnects between modules is then tested, with simulation results demonstrating that it is unlikely to fully engage when the expected errors are present. With this information, a requirement on the complexity of the interconnect design is inferred, and potential modifications that may increase its efficacy are suggested.</p

Barthian Bliss in the Films of Darren Aronofsky.

In this essay I argue that the films of director Darren Aronofsky correspond to the Text of Bliss defined in Roland Barthes\u27 The Pleasure of the Text. Using several aspects of audience reception to dissect Aronofsky’s films justifies identifying his oeuvre as texts of bliss: works that disquiet viewers by unsettling their assumptions of the world around them and their own relationships with it. This Barthes-based appropriation of literary theory to audience reception theory in Film Studies serves as an example of how personally-developed classification systems can be used to circumvent relying on popular opinion and corporate aims for guidance in film classification

Agriculture in Williams-West Arthur : report of a survey of farm practices

THIS article summarises the results of a survey of 81 farms in the Williams and West Arthur Shires, carried out by officers of the Department of Agriculture at the request of the Central South Zone Development Committee. Field work for the survey started in 1961

Agriculture in Western Australia : past, present and future

THE post war period has seen very rapid growth and changes in the agriculture of Western Australia. Almost every industry and region of the State has contributed to the growth of rural production which in turn has been responsible for much of the development in other sectors of the economy

Agriculture in the Lakes District : report of a survey of farm practices

At the request of the Central South Zone Development Committee a survey which covered 58 farms in the Lakes District was carried out by officers of the Department of Agriculture. Field work for the survey started in 1961. The Lakes District supports about 70 holdings adjoining a chain of salt lakes to the east of Newdegate and Hyden but west of the No. 1 Rabbit Proof Fence. The chain of lakes is about 70 miles long running in a N.N.W. to S.S.E. direction. The lakes are O\u27Connor, Carmody, Hurlstone, Varley, Gulson, Fox, Camm, King, and Pal lamp

Agriculture in Western Australia. 2. A preview of future development

THE agricultural areas of Western Australia produce most of the State\u27s agricultural output. Only isolated small areas of arable agriculture exist in the North- West and tropical areas of the State

Agriculture in Western Australia

A review of the development of agriculture in Western Australia with an outline of the distribution and importance of present agricultural and pastoral enterprises. WESTERN Australia\u27s economy has always been largely dominated by its pastoral and agricultural activities. For short periods gold has given greater annual returns than the products of farms and stations, but these periods have never been very long. Only in recent years has the value of factory production equalled that of our stations and farms

Verification of TG-61 dose for synchrotron-produced monochromatic x-ray beams using fluence-normalized MCNP5 calculations

Ion chamber dosimetry is being used to calibrate dose for cell irradiations designed to investigate photoactivated Auger electron therapy at the Louisiana State University CAMD synchrotron facility. This study performed a dosimetry intercomparison for synchrotron-produced monochromatic x-ray beams at 25 and 35 keV. Ion chamber depth-dose measurements in a PMMA phantom were compared with the product of MCNP5 Monte Carlo calculations of dose per fluence and measured incident fluence. Monochromatic beams of 25 and 35 keV were generated on the tomography beamline at CAMD. A cylindrical, air-equivalent ion chamber was used to measure the ionization created in a 10x10x10-cm3 PMMA phantom for depths from 0.6 to 7.7 cm. The American Association of Physicists in Medicine TG-61 protocol was applied to convert measured ionization into dose. Photon fluence was determined using a NaI detector to make scattering measurements of the beam from a thin polyethylene target at angles 30 degrees to 60 degrees. Differential Compton and Rayleigh scattering cross sections obtained from xraylib, an ANSI C library for x-ray-matter interactions, were applied to derive the incident fluence. MCNP5 simulations of the irradiation geometry provided the dose deposition per photon fluence as a function of depth in the phantom. At 25 keV the fluence-normalized MCNP5 dose overestimated the ion-chamber measured dose by an average of 7.2+/-3.0% to 2.1+/-3.0% for PMMA depths from 0.6 to 7.7 cm, respectively. At 35 keV the fluence-normalized MCNP5 dose underestimated the ion-chamber measured dose by an average of 1.0+/-3.4% to 2.5+/-3.4%, respectively. These results showed that TG-61 ion chamber dosimetry, used to calibrate dose output for cell irradiations, agreed with fluence-normalized MCNP5 calculations to within approximately 7% and 3% at 25 and 35 keV, respectively.Comment: 22 pages, 5 figure