An autonomous orbit transfer controller for the NASA Magnetospheric MultiScale satellite

With the ever more demanding goals of space exploration and research comes the need for more complex mission planning. Part of this complexity manifests itself in a satellite\u27s orbit specifications. An increasing number of explorer missions call for a group of satellites to maneuver while arranged in a tightly controlled formation, or constellation. In order to maintain these constellations at immense distances from Earth, engineers must rely on feedback systems within the satellites\u27 hardware. Controllers are created to manipulate the actuators, such as thrusters, and are therefore responsible for the economical use of fuel; overusing fuel can reduce a satellite\u27s useful lifetime. It is necessary to achieve all controller demands while monitoring fuel consumption when developing a system such as the one presented by this thesis. This thesis presents a detailed method of obtaining a simplified model of a spin-stabilized spacecraft and its environment, including relevant uncertainties, disturbances and sensor models. This thesis shows through rigorous simulations that it is feasible to control orbit maneuvers of spin-stabilized spacecraft to very strict specifications, despite the inclusion of sensor noise, thruster disturbance and bias, and nutation effects

Ion-Exchanged Waveguides in Glass Doped with PbS Quantum Dots

The lowest-loss (≤1 dB/cm) ion-exchanged waveguides in glass doped with PbS quantum dots are presented. Near-field mode profile and refractive index profile using the refracted near-field technique were measured for these waveguides. We demonstrate that the optical properties of this glass unchanged during the ion-exchange process

A utilization analysis of the Navy's financial management subspecialty coded officers

The Army, Air Force and Navy all have a cadre of Financial Management (FM) officers. Although the three military services all employ FM military officers, the structure, management practices and policies governing each service's FM officer communities differ. One consequence is that each service experiences a different FM officer utilization rate. This thesis presents each service's approach to its FM community structure and management, identifying strengths, weaknesses and utilization rates. Using , an analysis of the Navy's FM community was conducted. This analysis identified areas in which the Navy can improve the utilization rate of its FM subspecialty coded officers.http://archive.org/details/autilizationnaly109453736US Navy (USN) author.Approved for public release; distribution is unlimited

Current-induced bond rupture in single-molecule junctions: Effects of multiple electronic states and vibrational modes

Current-induced bond rupture is a fundamental process in nanoelectronic architectures such as molecular junctions and in scanning tunneling microscopy measurements of molecules at surfaces. The understanding of the underlying mechanisms is important for the design of molecular junctions that are stable at higher bias voltages and is a prerequisite for further developments in the field of current-induced chemistry. In this work, we analyse the mechanisms of current-induced bond rupture employing a recently developed method, which combines the hierarchical equations of motion approach in twin space with the matrix product state formalism, and allows accurate, fully quantum mechanical simulations of the complex bond rupture dynamics. Extending previous work [J. Chem. Phys. 154, 234702 (2021)], we consider specifically the effect of multiple electronic states and multiple vibrational modes. The results obtained for a series of models of increasing complexity show the importance of vibronic coupling between different electronic states of the charged molecule, which can enhance the dissociation rate at low bias voltages profoundly

First results with non-perturbative fermion improvement

We present initial results for light hadron masses and nucleon structure functions using a recent proposal for eliminating all $O(a)$ effects from Wilson fermion simulations in the quenched approximation. With initially limited statistics, we find a much more linear APE plot and a value of the axial coupling $g_A$ nearer to the experimental point than with comparable runs using unimproved Wilson fermions.Comment: 3 pages, 2 PostScript figures, LaTeX 2.09 with espcrc2.sty v2.6, amstex and epsf, talk presented at LATTICE96(phenomenology) by P. Stephenso

Methods and compositions for X-ray induced release from pH sensitive liposomes

Compositions including pH sensitive lipid vesicles comprised of a lipid layer, an agent, and an organic halogen such that the agent is released from the vesicles after exposure to ionizing radiation. Methods of delivering the agent to a target in a subject using the compositions provided herein are also described. The methods allow for controlled release of the agent. The timing of release of the agent from the lipid vesicle may be controlled as well as the location of release by timing and localizing the exposure to ionizing radiation exposure

Methods and compositions for X-ray induced release from pH sensitive liposomes

Compositions including pH sensitive lipid vesicles comprised of a lipid layer, an agent, and an organic halogen such that the agent is released from the vesicles after exposure to ionizing radiation. Methods of delivering the agent to a target in a subject using the compositions provided herein are also described. The methods allow for controlled release of the agent. The timing of release of the agent from the lipid vesicle may be controlled as well as the location of release by timing and localizing the exposure to ionizing radiation exposure

Leveraging the co-evolution of offline and online video games: an empirical study

Considerable research has been carried out on online shopping and the implications of this purchasing format for consumers and retailers. Most of these studies have focused on consumer attitudes towards online shopping, and how these can be useful predictors of online shopping adoption. Notwithstanding these insights from adoption theory, existing research has yet to distil the most effective means of understanding consumers’ attitudes towards online video game purchases. Based on a qualitative study, our study contributes to literature on adoption theory by presenting some explanations involving online video games purchases by identifying salient perceptions of online and offline motivations and advances ideas on the facilitating role of incentives in making purchase decisions

Persistent Penumbra in a Rabbit Stroke Model: Incidence and Histologic Characteristics

Duration and extent of penumbra determine the window and brain volume in which interventions may save injured tissue after stroke. Understanding the penumbra in animals is necessary in order to design models that translate to effective clinical therapies. New Zealand white rabbits were embolized with aged autologous clot (n = 23) or insoluble microspheres (n = 21). To examine effects of treatment on penumbra, sphere-stroked animals were treated with 3 μm microbubbles plus ultrasound (n = 19). Rabbits were euthanized at 4 or 24 hr. Infarct volume was measured following triphenyltetrazolium chloride (TTC) staining of brain sections. Penumbra was visualized using immunostaining of pimonidazole injected fifteen minutes prior to euthanasia. Potentially reversible penumbra was present in 14.3% stroked rabbits at 4 hours and 15.7% at 24 hours after embolic stroke and represented up to 35% of total lost tissue. Intervention at up to 24 hours may benefit a significant patient population