Multi-Attribute Tradespace Exploration as an Enabler of Architecting an Extensible On-Orbit Servicing System

Student research poste

Islamic Contracts of Finance in Malaysia

This paper explores the legal issues that arise in several of the principal instruments currently used in Islamic financing in Malaysia. Through the document review, it is submitted that these financial instruments consist of English-Malaysian commercial law, albeit set within an Islamic periphery. A consideration of how Islamic law could affect the litigation of these instruments is also undertaken and it is further submitted that given the current statutory and judicial framework of Islamic banking in Malaysia, the effect of Islamic commercial law upon these contracts appears to be morally exhortative, rather than legally enforceable. Finally, it is concluded that Islamic law is presently consigned to the margins of these financial contracts, and the consequences that arise from this conclusion are discussed.DOI: 10.15408/sdi.v10i1.64

T-EBC coating system failure modes

The failure modes during steam cycling between 110 o and 1316oC of silicon-ytterbium silicate EBC systems applied to silicon carbide substrates have been investigated. Premature delamination failure at silicon-ytterbium monosilicate (YbMS) interfaces is shown to result from thermal expansion mismatch driven channel cracking of the YbMS layer. These coating penetrating cracks enabled water vapor and oxygen to reach the silicon bond coat layer outer surface from the start of the thermal cycling process, and resulted in the rapid growth of an upper (b-phase) cristobalite thermally grown oxide (TGO) layer on the silicon surface. This silica layer suffered rapid edge erosion followed by thermal contraction mismatch induced delamination crack extension from the edge of the samples during cooling. Replacement of the steam erosion resistant monosilicate by its dislicate counterpart eliminated the channel crack oxidizer pathways to the silicon surface and delayed the growth of the silica TGO. The eventual failure of this coating architecture was governed by the development of a significant delamination driving force at the silicon - ytterbium dislicate interface as the TGO thickness exceeded ~5 mm. Coating failure life was then governed by the rate of permeation of oxidants through the ytterbium dislicate and by the very large thermal stresses developed during the upper to lower cristobalite transformation. Interestingly, the oxidant permeation is likely to increase during prolonged cycling as the diffusion barrier dislicate layer thickness was decreased by steam erosion. Preliminary results from investigations of several concepts for extending the coating system life will be described. One sought to utilize a thermal barrier coating to reduce the EBC temperature and water vapor flow rate at the ytterbium dislicate outer surface. A second has investigated the use of thin hafnia layers applied to the silicon bond coat outer surface to induce the formation of a composite silica/hafnium silicate TGO to reduce the thermal strain energy for delamination. Please click Additional Files below to see the full abstract

Junior Recital: Katherine Riess, trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Ms. Riess studies trombone with Wes Funderburk.https://digitalcommons.kennesaw.edu/musicprograms/1463/thumbnail.jp

Faculty Recital: James Barket, string bass, A Recital of Classical Music, Folk Song Arrangements and Spiritual Music for String Bass

KSU Faculty Recital featuring James Barket on string bass assisted by Gabriel Monticello, William Thornton, Aaron Yackley, Daniel Barket, Daniel Kim, David Metrio, and Matt Richards.https://digitalcommons.kennesaw.edu/musicprograms/1074/thumbnail.jp

Testing Assumptions in Deliberative Democratic Design: A Preliminary Assessment of the Efficacy of the Participedia Data Archive as an Analytic Tool

At smaller social scales, deliberative democratic theory can be restated as an input-process-output model. We advance such a model to formulate hypotheses about how the context and design of a civic engagement process shape the deliberation that takes place therein, as well as the impact of the deliberation on participants and subsequent policymaking. To test those claims, we extract and code case studies from Participedia.net, a research platform that has adopted a self-directed crowd-sourcing strategy to collect data on participatory institutions and deliberative interventions around the world. We explain and confront the challenges faced in coding and analyzing the Participedia cases, which involves managing reliability issues and missing data. In spite of those difficulties, regression analysis of the coded cases shows compelling results, which provide considerable support for our general theoretical model. We conclude with reflections on the implications of our findings for deliberative theory, the design of democratic innovations, and the utility of Participedia as a data archive

On-Board Real-Time Trajectory Planning for Fixed Wing Unmanned Aerial Vehicles in Extreme Environments

A team from the University of Bristol have developed a method of operating fixed wing Unmanned Aerial Vehicles (UAVs) at long-range and high-altitude over Volcán de Fuego in Guatemala for the purposes of volcanic monitoring and ash-sampling. Conventionally, the mission plans must be carefully designed prior to flight, to cope with altitude gains in excess of 3000 m, reaching 9 km from the ground control station and 4500 m above mean sea level. This means the climb route cannot be modified mid-flight. At these scales, atmospheric conditions change over the course of a flight and so a real-time trajectory planner (RTTP) is desirable, calculating a route on-board the aircraft. This paper presents an RTTP based around a genetic algorithm optimisation running on a Raspberry Pi 3 B+, the first of its kind to be flown on-board a UAV. Four flights are presented, each having calculated a new and valid trajectory on-board, from the ground control station to the summit region of Volcań de Fuego. The RTTP flights are shown to have approximately equivalent efficiency characteristics to conventionally planned missions. This technology is promising for the future of long-range UAV operations and further development is likely to see significant energy and efficiency savings

The SAMI Galaxy Survey: Revising the Fraction of Slow Rotators in IFS Galaxy Surveys

The fraction of galaxies supported by internal rotation compared to galaxies stabilized by internal pressure provides a strong constraint on galaxy formation models. In integral field spectroscopy surveys, this fraction is biased because survey instruments typically only trace the inner parts of the most massive galaxies. We present aperture corrections for the two most widely used stellar kinematic quantities $V/\sigma$ and $\lambda_{R}$. Our demonstration involves integral field data from the SAMI Galaxy Survey and the ATLAS$^{\rm{3D}}$ Survey. We find a tight relation for both $V/\sigma$ and $\lambda_{R}$ when measured in different apertures that can be used as a linear transformation as a function of radius, i.e., a first-order aperture correction. We find that $V/\sigma$ and $\lambda_{R}$ radial growth curves are well approximated by second order polynomials. By only fitting the inner profile (0.5$R_{\rm{e}}$), we successfully recover the profile out to one $R_{\rm{e}}$ if a constraint between the linear and quadratic parameter in the fit is applied. However, the aperture corrections for $V/\sigma$ and $\lambda_{R}$ derived by extrapolating the profiles perform as well as applying a first-order correction. With our aperture-corrected $\lambda_{R}$ measurements, we find that the fraction of slow rotating galaxies increases with stellar mass. For galaxies with $\log M_{*}/M_{\odot}>$ 11, the fraction of slow rotators is $35.9\pm4.3$ percent, but is underestimated if galaxies without coverage beyond one $R_{\rm{e}}$ are not included in the sample ($24.2\pm5.3$ percent). With measurements out to the largest aperture radius the slow rotator fraction is similar as compared to using aperture corrected values ($38.3\pm4.4$ percent). Thus, aperture effects can significantly bias stellar kinematic IFS studies, but this bias can now be removed with the method outlined here.Comment: Accepted for Publication in the Monthly Notices of the Royal Astronomical Society. 16 pages and 11 figures. The key figures of the paper are: 1, 4, 9, and 1