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Experimental data are used in theoretical models to study the effects of input voltage and gas flow rate on plasma and background gas parameters in a voltage range where the transition from nondischarge to full-discharge happens. To this end, a specific methane-fed dielectric barrier discharge is used as a plasma reactor, and electrical modeling, the Boltzmann equation method, and emission spectrum analysis are employed to calculate plasma parameters and gas heating. The output of this study proves that a uniform plasma with a controllable background gas heating is achievable by the adjustment of input parameters such as voltage and gas flow rate in a well-designed dielectric barrier discharge.

Model-Based Systems Engineering (MBSE) represents a move away from the traditional, document-centric approach to systems engineering. MBSE has the potential to promote consistency, communication, clarity, and maintainability within systems engineering projects. MBSE also has the potential to address one of the well-known issues of the systems engineering ‘Vee’ model – the late discovery of errors. Airbus Space were interested in the application of MBSE to spacecraft, and a literature review elicited the following research aim: ‘To create an MBSE framework, to be deployed during Phase B of the system life cycle, that is able to capture and communicate spacecraft mission design information; is able to perform dynamic simulation of spacecraft behaviour; and is reusable and applicable to different spacecraft missions’. Research presented in this thesis describes the ‘Spacecraft Early Analysis Model’ (SEAM) as one possible solution. The design science research methodology has been adopted to support the development, demonstration, and evaluation of the SEAM. The SysML-based SEAM spans multiple tools (Cameo Systems Modeler, Microsoft Excel, MATLAB, STK) and provides clear definitions of the mission, system, and concept of operations during Phase B. Through an innovative model structure that incorporates a novel representation of functions and modes, the SEAM is executable. This enables the simulation of the system behaviour in response to ‘Flight Operations Procedures’. The SEAM has been demonstrated via its application to three case studies. Case Study 1 involves a dynamic mass memory analysis of Biomass; a low-Earth orbit, Earth-observation mission. Case Study 2 investigates a critical deployment sequence onboard Biomass. Case Study 3 models the ‘Egress from lander’ sequence of ExoMars, a Mars rover mission. The results of these case studies have been verified and sensitivity analyses have been performed. Qualitative feedback from Airbus Space engineers provides evidenc

Model-Based Systems Engineering (MBSE) represents a move away from the traditional, document-centric approach to systems engineering. MBSE has the potential to promote consistency, communication, clarity, and maintainability within systems engineering projects. MBSE also has the potential to address one of the well-known issues of the systems engineering ‘Vee’ model – the late discovery of errors. Airbus Space were interested in the application of MBSE to spacecraft, and a literature review elicited the following research aim: ‘To create an MBSE framework, to be deployed during Phase B of the system life cycle, that is able to capture and communicate spacecraft mission design information; is able to perform dynamic simulation of spacecraft behaviour; and is reusable and applicable to different spacecraft missions’. Research presented in this thesis describes the ‘Spacecraft Early Analysis Model’ (SEAM) as one possible solution. The design science research methodology has been adopted to support the development, demonstration, and evaluation of the SEAM. The SysML-based SEAM spans multiple tools (Cameo Systems Modeler, Microsoft Excel, MATLAB, STK) and provides clear definitions of the mission, system, and concept of operations during Phase B. Through an innovative model structure that incorporates a novel representation of functions and modes, the SEAM is executable. This enables the simulation of the system behaviour in response to ‘Flight Operations Procedures’. The SEAM has been demonstrated via its application to three case studies. Case Study 1 involves a dynamic mass memory analysis of Biomass; a low-Earth orbit, Earth-observation mission. Case Study 2 investigates a critical deployment sequence onboard Biomass. Case Study 3 models the ‘Egress from lander’ sequence of ExoMars, a Mars rover mission. The results of these case studies have been verified and sensitivity analyses have been performed. Qualitative feedback from Airbus Space engineers provides evidenc

MBSE aims to integrate engineering models across tools and domain boundaries to support traditional systems engineering activities (e.g., requirements elicitation and traceability, design, analysis, verification and validation). However, MBSE does not inherently solve interoperability with the multiple model-based infrastructures involved in a complex systems engineering project. The challenge is to implement digital continuity in the three dimensions of systems engineering: across disciplines, throughout the lifecycle, and along the supply chain. Space systems are ideal candidates for the application of MBSE and semantic modelling as these complex and expensive systems are mission-critical and often co-developed by multiple stakeholders. In this paper, the authors introduce the concept of Semantic Systems Engineering (SES) as an expansion of MBSE practices to include semantic modelling through SWTs. The paper also presents the progress and status of a novel Semantic Systems Engineering Ontology (SESO) in the context of a specific design case study – the Large Aperture Space Telescope mission.

Transportation agencies have increasingly pursued the application of TSMO strategies to optimize the performance of the existing transportation system and provide lower cost and more sustainable solutions than traditional transportation infrastructure projects that add lanes to meet safety, mobility, and reliability challenges. An emphasis on transportation equity can create the opportunity for identifying how TSMO strategies can play an effective role in addressing the needs of disadvantaged, underserved, or overburdened populations, thus making it important to define the connections between TSMO and equity. Because transportation inequities result from a complex combination of past actions and external factors, changes in management and operations of the existing transportation system alone will not achieve total transportation equity. However, TSMO can help advance transportation equity with the goal of optimizing the multimodal transportation system for all users. Although transportation equity is not a new concept, it is an evolving field, which creates challenges in evaluating and addressing it. Sometimes, a single agency may not be able to address the equity issue on its own or may have conflicting objectives with other agencies that they would need to partner with to address an issue.