Comparison of Traditional Versus CubeSat Remote Sensing: A Model-Based Systems Engineering Approach

This thesis compares the ability of both traditional and CubeSat remote sensing architectures to fulfill a set of mission requirements for a remote sensing scenario. Mission requirements originating from a hurricane disaster response scenario are developed to derive a set of system requirements. Using a Model-based Systems Engineering approach, these system requirements are used to develop notional traditional and CubeSat architecture models. The technical performance of these architectures is analyzed using Systems Toolkit (STK); the results are compared against Measures of Effectiveness (MOEs) derived from the disaster response scenario. Additionally, systems engineering cost estimates are obtained for each satellite architecture using the Constructive Systems Engineering Cost Model (COSYSMO). The technical and cost comparisons between the traditional and CubeSat architectures are intended to inform future discussions relating to the benefits and limitations of using CubeSats to conduct operational missions

Out of sight, out of mind: Legislative perceptions and congressional representation.

Scholars of representative democracy have long struggled with basic questions related to representation: What do we mean by representation? How do we evaluate the quality or success of representation? These questions have been pursued with particular intensity by scholars who examine how members of Congress represent the constituents in their state or district. Central to the congressional literature are issues such as how members know the preferences of their constituents, and whether those preferences influence congressional decision-making. While scholars have explored these questions for half a century, we still do not have a consensus on the answers to these questions, or even how to proceed in addressing them. This research focuses on an aspect of congressional representation that has received far too little attention---legislators' perceptions of their constituents. I put forward a theory of legislative perception that addresses the central question of who is represented. My arguments are grounded in contemporary work in the field of cognitive psychology, which helps to shed new light on the representation puzzle. Information that is more easily accessible in individual legislators' memory is likely to shape who they see when the look at the district. This research examines both the mechanisms of legislative perception and the implications for congressional representation. Perceptions of constituency are issue-specific, and this research focuses on health and natural resources policy. I examine perceptions by conducting face-to-face interviews with professional staff to members of the U.S. House of Representatives. The interviews include structured survey instruments and are combined with a dataset consisting of economic, political, and demographic variables, which allow for the evaluation of alternative hypotheses from the political science and cognitive psychology literatures. I find that constituents who are organized and active, contacting the legislator more frequently and making larger financial contributions, are more likely to be seen than either the median voter or a representative sample of the district. These findings identify a cognitive basis for inequality in the everyday practice of representation on Capitol Hill. Legislators and their staff have a distorted view of their district that favors well-organized and well-financed constituents.Ph.D.Political scienceSocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/123908/2/3106123.pd

Development and characterisation of a novel biodegradable IPC biomaterial

grantor: University of TorontoThe objective of this study was to develop a biodegradable interpenetrating phase composite (IPC) for the potential use as a biodegradable, load-bearing implant for bone augmentation and segmental replacement. Calcium polyphosphate (CPP) and polycaprolactone (PCL) were selected for the development of the IPC biomaterial. Porous CPP discs were produced by cold pressing and sintering amorphous CPP powders. The discs were pressure-infiltrated with PCL to yield the IPC. A 14-day in vitro degradation study was performed in a tris-buffered pH 7.4 solution at 37\sp\circC. The degradation was characterised by three-point bend testing and the phosphorus levels of the degradation media were quantified by colourimetric analysis. The mechanical testing ascertained the IPC to possess superior bending strength, strain to failure and 'toughness' relative to the porous CPP. The mechanical properties were found to decline with degradation; however, in general the IPC maintained greater mechanical properties in comparison with the monolithic CPP ceramic.M.A.Sc

The synthesis of peptide bonds.

This thesis reports work which is an integral part of a larger project underway in these laboratories under the direction of Dr. R. V. V. Nicholls, the ultimate goal of which is the synthesis of several naturally-occurring oligopeptides with physiological activities. The purpose of the present work is to initiate an investigation of the problems associated with the synthesis of peptide bonds. Two aspects are under consideration here; first, to study the methods by which amine acids can be rendered monofunctional so that their reactions may be strictly controlled; second, to examine amidation reactions from the standpoint of the controlled synthesis of peptide bonds