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2019

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Articles 5941 - 5970 of 10504

Full-Text Articles in Engineering

Comprehensive Study Of Study Of Optimal Synergetic Skip Entries With Dynamic Thrust Vectoring Control, Jeremiah M. Webb Mar 2019

Comprehensive Study Of Study Of Optimal Synergetic Skip Entries With Dynamic Thrust Vectoring Control, Jeremiah M. Webb

Theses and Dissertations

The atmospheric skip entry has been studied since London's presentation in 1962 describing a more fuel efficient means of altering the orbital inclination of satellites. Since London, research over the decades since has traversed many aspects of this field with varying degrees of success. The present research employs the use of modern optimal control software, complex dynamics with minor simplifications, and thrust vectoring to re-approach the aerocruise atmospheric skip entry. Using the aerodynamics of the X-34, the aerocruise problem is first compared to the un-powered aeroglide where it is shown that the aerocruise is capable of increasing the inclination change …


Computational Aerothermodynamic Analysis Of Satellite Trans-Atmospheric Skip Entry Survivability, John J. Runco Mar 2019

Computational Aerothermodynamic Analysis Of Satellite Trans-Atmospheric Skip Entry Survivability, John J. Runco

Theses and Dissertations

Computational aerothermodynamic analysis is presented for a spacecraft in low Earth orbit performing an atmospheric skip entry maneuver. Typically, atmospheric reentry is a terminal operation signaling mission end-of-life and, in some instances, executed for spacecraft disposal. A variation on reentry – skip entry – is an aeroassisted trans-atmospheric maneuver in which a spacecraft utilizes the effects of aerodynamic drag in order to reduce energy prior to a terminal entry, pinpoint a targeted entry, or change orbital elements such as inclination. Spacecraft performing a skip entry enable new modes of maneuver to enhance operations in nominal or possibly contested mission environments. …


Characterization And Anomalous Diffusion Analysis Of A 100w Low Power Annular Hall Effect Thruster, Megan N. Maikell Mar 2019

Characterization And Anomalous Diffusion Analysis Of A 100w Low Power Annular Hall Effect Thruster, Megan N. Maikell

Theses and Dissertations

A Busek 100W low-power annular Hall effect thruster was characterized to determine the thruster’s best operating parameter range and to study plasma oscillations within the thruster. These experiments were conducted using xenon gas in the Space Propulsion Analysis and System Simulator chamber at the Air Force Institute of Technology on Wright-Patterson Air Force Base. The thruster’s performance characteristics were evaluated at nominal discharge voltages and constant total mass flow rate, solenoid current, and keeper current to determine the operating conditions optimizing divergence angle, beam efficiency, and discharge loss. This was accomplished using a Faraday probe to determine the plume’s current …


Limited-Duty-Cycle Satellite Formation Control Via Differential Drag, Talon A. Townley Mar 2019

Limited-Duty-Cycle Satellite Formation Control Via Differential Drag, Talon A. Townley

Theses and Dissertations

As CubeSat formation flying missions relying on differential drag control become increasingly common, additional missions based on this control must be studied. A mission planning tool is investigated to control the relative spacing of a CubeSat formation where differential drag is the sole control mechanism. System performance is investigated under varying perturbations and a range of system parameters, including limiting the control duty cycle. Optimal solutions based on using a pseudo spectral numerical solver, GPOPS-II, to minimize maneuver time. This study includes the development of a mission planning tool to work with the modeled CubeSat mission to calculate optimal maneuvers …


Comparison Of Novel Heuristic And Integer Programming Schedulers For The Usaf Space Surveillance Network, Kanit Dararutana Mar 2019

Comparison Of Novel Heuristic And Integer Programming Schedulers For The Usaf Space Surveillance Network, Kanit Dararutana

Theses and Dissertations

Space is a highly congested and contested domain begetting the importance of prioritizing the Space Situational Awareness (SSA) mission. With increased dependence on space assets, scheduling and tasking of the Space Surveillance Network (SSN) is vitally important to maintaining space dominance. According to the 2004 USSTRATCOM Strategic Directive 505-1 (SD 505-1) the SSN uses centralized tasking, with decentralized scheduling. Enhancing SSA within available resources is paramount, and the development of a centralized SSN scheduler to maximize performance is crucial. This research develops and compares novel scheduling models to a model reflecting the 2004 SD 505-1. Novel schedulers were developed to …


Analysis Of Military Construction Cost Growth In Major Defense Acquisition Programs, Emily E. Angell Mar 2019

Analysis Of Military Construction Cost Growth In Major Defense Acquisition Programs, Emily E. Angell

Theses and Dissertations

This study is an exploratory analysis combining military construction (MILCON) data from the Selected Acquisition Reports (SAR) of Major Defense Acquisition Programs (MDAP) with the associated Automated Civil Engineer System project actual costs. The analysis uses both descriptive and inferential statistics to identify cost growth of MILCON at the programmatic level as well as to bridge the gap between SAR estimates and actual project costs within those program-level estimates. Overall, programs experience more negative growth (cost savings) in MILCON estimates on SARs, typically less than 0.2% of the total program cost implying minimal impact to program decisions. Estimates got more …


Assessing Artificial Agent Response Time Effects On Human-Agent Teams In Variable Inter-Arrival Time Environments, David J. Canzonetta Mar 2019

Assessing Artificial Agent Response Time Effects On Human-Agent Teams In Variable Inter-Arrival Time Environments, David J. Canzonetta

Theses and Dissertations

Autonomous systems have gained an expanded presence within the Department of Defense (DoD). Furthermore, the DoD has clearly stated autonomous systems must extend the capabilities of their human operators. Thus, the exploration of strategies for effective pairing of humans and automation supports this vision. Previous research demonstrated that the time at which an automated agent assumes a task for its human teammate, or agent response time (ART), affects human-agent team performance, human engagement, and human workload. However, in this research environment, the time between subsequent tasks appearing to the human-agent team, or inter-arrival time (IAT), remained constant. Variable IAT environments …


Methodology For Including Base Infrastructure In Conceptual System Analysis, Patrick J. Kelly Iv Mar 2019

Methodology For Including Base Infrastructure In Conceptual System Analysis, Patrick J. Kelly Iv

Theses and Dissertations

The 2018 National Defense Strategy defines a transition to agile basing, where the logistics footprint of new conceptual systems can be distributed across a set of airfields, instead of one main operating base. Currently, there is no capability to assess early concepts using airfield data. This research develops a methodology and a tool that assesses system concepts using world-wide civil and military airfield infrastructure, such as runway parameters, parking, munitions, fuel and warehouse storage, and distance to areas of interest. Specifically, the focus of the thesis is on concepts for the Intelligence, Surveillance, and Reconnaissance (ISR) Strike mission. Four concepts …


A Mixed Integer Programming Framework For The Fuel Optimal Guidance Of Complex Spacecraft Rendezvous And Proximity Operation Missions, Andrew S. Levalley Mar 2019

A Mixed Integer Programming Framework For The Fuel Optimal Guidance Of Complex Spacecraft Rendezvous And Proximity Operation Missions, Andrew S. Levalley

Theses and Dissertations

Space is a contested, congested, and competitive environment where space situational awareness (SSA) is a key factor in the long term sustainability of space as a national interest. Space-based SSA conducted by inspector satellites is critical to the detecting, tracking, and attribution of actions in space. Thus, space-based fuel-optimal maneuvers are essential to increasing mission life and improving the capability of inspector satellites working to characterize resident space objects (RSOs) in geosynchronous orbit (GEO). Additionally, on-orbit inspection missions can be characterized by multiple waypoint visits where an inspector is accomplishing a set of proximity operation mission objectives through the visit …


Identification Of New Glutamate Decarboxylases From Streptomyces For Efficient Production Of Γ-Aminobutyric Acid In Engineered Escherichia Coli, Haina Yuan, Hongbo Wang, Ozkan Fidan, Yong Qin, Gongnian Xiao, Jixun Zhan Mar 2019

Identification Of New Glutamate Decarboxylases From Streptomyces For Efficient Production Of Γ-Aminobutyric Acid In Engineered Escherichia Coli, Haina Yuan, Hongbo Wang, Ozkan Fidan, Yong Qin, Gongnian Xiao, Jixun Zhan

Biological Engineering Faculty Publications

Background

Gamma (γ)-Aminobutyric acid (GABA) as a bioactive compound is used extensively in functional foods, pharmaceuticals and agro-industry. It can be biosynthesized via decarboxylation of monosodium glutamate (MSG) or L-glutamic acid (L-Glu) by glutamate decarboxylase (GAD; EC4.1.1.15). GADs have been identified from a variety of microbial sources, such as Escherichia coli and lactic acid bacteria. However, no GADs from Streptomyces have been characterized. The present study is aimed to identify new GADs from Streptomyces strains and establish an efficient bioproduction platform for GABA in E. coli using these enzymes.

Results

By sequencing and analyzing the genomes of three Streptomycesstrains, …


Investigating Air Pollution And Equity Impacts Of A Proposed Transportation Improvement Program For Tampa, Talha Kemal Kocak Mar 2019

Investigating Air Pollution And Equity Impacts Of A Proposed Transportation Improvement Program For Tampa, Talha Kemal Kocak

USF Tampa Graduate Theses and Dissertations

Transportation infrastructure is important for human mobility and population well-being. However, it can also have detrimental impacts on health and equity, including through increased air pollution and its unequal social distribution. There is a need for better understanding of these impacts and for better approaches that improve health and equity outcomes of transportation planning programs. In this study, we are investigating the air pollution and health equity impacts of an ongoing large-scale metropolitan transportation improvement program, Tampa Bay Next (TBNext). Specific objectives are: 1) to characterize and quantify the air pollution levels and population exposures resulting from the roadway expansion …


A Faculty Retreat Model Featuring Collaborative And Active Learning, Yeow Siow, Michael Scott, Houshang Darabi, Farzad Mashayek Mar 2019

A Faculty Retreat Model Featuring Collaborative And Active Learning, Yeow Siow, Michael Scott, Houshang Darabi, Farzad Mashayek

ASEE IL-IN Section Conference

A workshop-style, active-learning model was recently implemented in a Mechanical and Industrial Engineering (MIE) department retreat prior to the start of the Fall 2018 term. The department is currently undergoing a curriculum redesign, and a special committee was created to design the talking points for the retreat. Among the concerns were: meaning of grades, expectation of grade distribution, adoption of teaching pedagogies that align with the department goals, and definition of teaching excellence. Opinions were divided, and many felt strongly about each topic. New and non-tenure-track faculty were initially assigned as scribe or presenter, so as to encourage participation. A …


A Model For Incorporating Undergraduate Research Into An Engineering Curriculum, Douglas Stamps Mar 2019

A Model For Incorporating Undergraduate Research Into An Engineering Curriculum, Douglas Stamps

ASEE IL-IN Section Conference

A model is described for incorporating undergraduate research into an engineering curriculum through a vertically integrated design sequence. The sequence is composed of five courses: one each during the spring semester of the freshmen through junior years and two courses during the senior year. Each course offers skills that provide scaffolding for students to contribute to a team performing an engineering design project or research project. Teams are composed of freshmen through seniors (i.e., vertically integrated) and led by seniors. A strength of the model for undergraduate research is that upper level students can mentor lower level students, which allows …


International Aviation Collaboration In A Study Abroad Program, Brian Kozak, Peng Hao Wang Mar 2019

International Aviation Collaboration In A Study Abroad Program, Brian Kozak, Peng Hao Wang

ASEE IL-IN Section Conference

Aviation is a global industry. As we continue to push the boundaries of technical advancements and operational efficiency in the aviation industry, the reliance on the global workforce will continue to increase. In the United States of America, the majority of educational establishments focus mainly in the education and training of students for the US aviation industry. The narrow focus significantly limits the amount of exposure and opportunities available to the students of these educational establishments. In order to improve global exposure and provide students with opportunities outside of the US aviation industry, the authors of the paper successfully established …


Writing Children’S Stories To Improve Engineering Student’S Communication With Non-Engineering Audiences, Benjamin D. Mcpheron, Katelyn J. Butler Mar 2019

Writing Children’S Stories To Improve Engineering Student’S Communication With Non-Engineering Audiences, Benjamin D. Mcpheron, Katelyn J. Butler

ASEE IL-IN Section Conference

One of the biggest challenges for students in science and engineering is communicating technical information to a non-technical audience. Students may struggle because they are not adept writers, because they cannot divorce the ideas from the jargon, or because they simply don't understand the material well enough to explain it to someone else. To attempt to address this issue, this study proposes the use of children’s stories to help students practice writing for a target, non-technical audience. To measure the efficacy of this method, junior level engineering students in an electronics course in Fall 2018 were asked to write children’s …


Application Of Computational Tools To Spaghetti-Based Truss Bridge Design, Jin Xu, Jiliang Li, Nuri Zeytinoglu, Jinyuan Zhai Mar 2019

Application Of Computational Tools To Spaghetti-Based Truss Bridge Design, Jin Xu, Jiliang Li, Nuri Zeytinoglu, Jinyuan Zhai

ASEE IL-IN Section Conference

Application of Computational Tools to Spaghetti-Based Truss Design

Statics and Strength of Materials are two foundational courses for Mechanical/Civil Engineering. In order to assist students in better understanding and applying concepts to a meaningful design task, SolidWorks and theoretical calculation were used for a spaghetti-bridge design contest with the constraints of given maximum weight and allowable support-material weight. As the first step of this iterative designing process, both extrude feature and structural member were introduced to model planar bridge trusses. Then SolidWorks’ Statics module was used to run FEA analysis of the structural performance in efforts to optimize the …


Innovative Remote Smart Home For Immersive Engagement, Kevin B. Martin, Abul Azad, Mohammed Adnan Shareef, Mrinal Roy Mar 2019

Innovative Remote Smart Home For Immersive Engagement, Kevin B. Martin, Abul Azad, Mohammed Adnan Shareef, Mrinal Roy

ASEE IL-IN Section Conference

An openly accessible, remotely operated smart home will be demonstrated as a tool for students to learn about residential energy usage and environmental impacts. Specifically, the demonstration unit provides classrooms an engaging experience that teaches students about energy efficiency technologies and how their behavior will have an impact on energy usage and the environment. It is expected that as students become aware of and understand how various energy efficiency technologies work barriers to their adoption will be lowered. The use of a web accessible, remote laboratory dramatically reduces lab setup time and equipment cost/space requirements for educators. Special attention is …


Development Of A Set Of Pre-Class Videos For Electromagnetic Theory, Benjamin Mcpheron, Josiah D. Kunz Mar 2019

Development Of A Set Of Pre-Class Videos For Electromagnetic Theory, Benjamin Mcpheron, Josiah D. Kunz

ASEE IL-IN Section Conference

One important aspect of experiential learning is allowing students time to reflect on new concepts before the application of the material. Most commonly, this is attempted by assigning readings from a textbook, but research suggests that few students complete these readings. This discouraging fact has prompted the use of other resources, such as videos, to supplement pre-class readings in order to introduce new material. Previous work has been completed by this author to produce pre-class videos for use in an introductory circuits course. This paper extends that work to the development of pre-class videos for a senior level electrical engineering …


Interactive Simulations In Signals And Systems, Anthony Richardson Mar 2019

Interactive Simulations In Signals And Systems, Anthony Richardson

ASEE IL-IN Section Conference

Several interactive simulations that promote a better understanding of concepts traditionally encountered in an undergraduate Signals and Systems course are described. The simulations were developed to support the text “Signals & Systems: Theory and Applications” by Ulaby and Yagle. The text and all simulation programs are available for free download (ss2.eecs.umich.edu) as part of the Free Electrical Engineering Textbook Initiative from the University of Michigan.

All simulations use graphical control elements that allow the student to interact with the simulation. Many of the simulations use either real audio or image data so that the student can vary parameters of the …


Design Of A Carburizing Treatment Of Steel Base Gear In The Materials Science Course, Jiliang Li, Jin Xu, Nuri Zeytinoglu, Jinyuan Zhai Mar 2019

Design Of A Carburizing Treatment Of Steel Base Gear In The Materials Science Course, Jiliang Li, Jin Xu, Nuri Zeytinoglu, Jinyuan Zhai

ASEE IL-IN Section Conference

Diffusion PDE Application to Carburizing Treatment of Steel Base Gear

An introductory materials-science course is required in the mechanical engineering curriculum of many universities. This article describes an example effort to incorporate programming, diffusion transfer, heat treatment process and mechanical-property determination as an integral part of the materials-science course instruction. This effort was undertaken in order to give students additional experience in Fick’s 1st and 2nd laws and in-depth understanding of physics and mathematics involved in diffusion analysis. We chose to focus on Fick’s second law because its applications are not restricted to the materials-science field [1]. As …


Providing A Meaningful Lab Experience For A Manufacturing Processes Course, Kevin Molyet Mar 2019

Providing A Meaningful Lab Experience For A Manufacturing Processes Course, Kevin Molyet

ASEE IL-IN Section Conference

No abstract provided.


Introducing Concept Maps In Undergraduate Thermodynamics, Jessie Lofton Mar 2019

Introducing Concept Maps In Undergraduate Thermodynamics, Jessie Lofton

ASEE IL-IN Section Conference

Concept maps, also called mind maps, are a widely utilized educational tool. While numerous studies cite the benefits of concept mapping as a tool for student learning, the use of concept maps is more common in non-engineering disciplines. This study examines student perceptions and academic performance in an undergraduate, introductory Thermodynamics course for students majoring in Mechanical Engineering. The pedagogical approach includes incorporating student-developed concept maps, as well as an interactive study tool for First Law analysis. Qualitative and quantitative results are presented. Results are limited to a single institution and a small sample size of students. Future work will …


Course And Exam Statistics In Electrical Engineering, D Blandford, Mark Randall, Jessica Lofton Mar 2019

Course And Exam Statistics In Electrical Engineering, D Blandford, Mark Randall, Jessica Lofton

ASEE IL-IN Section Conference

This paper examines the course and national exam records for about fifty students in electrical engineering. The data includes the following: SAT/ACT scores, high school math and science grades, high school GPA, high school class rank, and grades for math, science, and engineering courses in the first two years of the major for undergraduates in electrical engineering. The data is analyzed seeking a correlation with success in the major which is measured by the cumulative GPA at or near graduation.

Two types of correlation data are presented. First, correlation with individual data items and success in the major is established. …


A Critical Look At Mechanical Engineering Curriculum: Assessing The Need, Yeow Siow, Jamison Szwalek, Jonathan Komperda, Houshang Darabi, Farzad Mashayek Mar 2019

A Critical Look At Mechanical Engineering Curriculum: Assessing The Need, Yeow Siow, Jamison Szwalek, Jonathan Komperda, Houshang Darabi, Farzad Mashayek

ASEE IL-IN Section Conference

Since the Morrill Land-Grant Colleges Act in 1862, the U.S. higher education system has been serving the industrial world, and engineering study is the epitome of this ideal: Serve those who will practice it in the immediate future. The mechanical engineering curricula have long been evolving to meet the demand of the changing economy, and it may soon be due for a major update. This paper aims to present an initial effort to explore the need for a systematic redesign, or reform, of the mechanical engineering curriculum at [Institution X], where curricular changes during the past five decades have been …


Student Success And Retention From The Perspectives Of Engineering Students And Faculty, Amy Chan-Hilton Mar 2019

Student Success And Retention From The Perspectives Of Engineering Students And Faculty, Amy Chan-Hilton

ASEE IL-IN Section Conference

Student retention and success is a complex issue, with many factors that impact an individual student’s retention and these factors varying across all of our students. At the University of Southern Indiana (USI), efforts within engineering, as well as across the college and university, have included intentional academic support services (such as expanded advising and tutoring services) and student development programs and extracurricular activities to foster student communities and a student’s sense of belonging. In addition, evidence indicates that implementing curricular changes across an engineering program and within specific courses, such as implementing active learning, instructional innovations, and high-impact practices, …


Theoretical Investigation Of The Ring Opening Of Cyclohexane On Ir(111) And Pt(111), Kushal Ghale Mar 2019

Theoretical Investigation Of The Ring Opening Of Cyclohexane On Ir(111) And Pt(111), Kushal Ghale

LSU Master's Theses

Diesel engines have higher fuel efficiency and can burn cleaner than gasoline engines. To enhance quality of diesel fuels as measured by the cetane number (CN), the removal of aromatic compounds is necessary. A potentially highly efficient approach would be to convert aromatics to saturated cycloparaffin, followed by selective ring opening to linear or branched alkanes, to increase the CN. Here the focus of the project is to study the mechanism of metal-catalyzed ring opening (RO) of cyclohexane (denoted CHA, or c-C6H12) through theoretical and computational modeling. CHA, a simplest cycloparaffin, is used as probe molecule …


String Out And Compressibility Effect On Pressure Rise In A Shut-In Well, Nicholas Henry Mar 2019

String Out And Compressibility Effect On Pressure Rise In A Shut-In Well, Nicholas Henry

LSU Master's Theses

Gas kick migration experiments were performed in a small-scale well prototype model of annular geometry to analyze the behavior of gas kicks in highly non-Newtonian fluids. The objective was to isolate and estimate the effects system compressibility and bubble string out have on the pressure build up in a situation in which a gas kick rises through a noncirculating drilling mud in a vertical well.

The experiments consisted of 2 tests. The first test measured the apparent compressibility of the liquid phase of the experiment – that phase which simulated the drilling mud in a gas kick situation. The second …


Improvement Of Thermal Technical Characteristics Of Wall Ceramic Material Based On Low-Sorted Lyssovid Suglinks And Modified Liquid Glass, Anvar Ishanovich Adilkhodjayev, I.M. Mahamataliev, A.T. Ilyasov Mar 2019

Improvement Of Thermal Technical Characteristics Of Wall Ceramic Material Based On Low-Sorted Lyssovid Suglinks And Modified Liquid Glass, Anvar Ishanovich Adilkhodjayev, I.M. Mahamataliev, A.T. Ilyasov

Journal of Tashkent Institute of Railway Engineers

Application of low-grade loesslike loams (NLS) in the production of effective wall ceramics requires development of methods of increase of frost-resistance of ceramic porizovannoy matrix. It can be attained by adjusting of porosity of structure. In the Tashkent architectural-build institute possibility of making of an effective wall ceramic material is studied on the basis of NLS with the use of dobavki- ash-taking away of Angrenskoy TES and modified liquid glass as a modifier of porous structure. It is set that introduction of addition ash-taking away in an amount 25 % from mass of NLS and burning at the temperature of …


The Risk Of Ballast Graphic Towards Pozzles Moving Frequency, Sh.Sh. Abdukamilov, A.Yu. Mamadaliyev Mar 2019

The Risk Of Ballast Graphic Towards Pozzles Moving Frequency, Sh.Sh. Abdukamilov, A.Yu. Mamadaliyev

Journal of Tashkent Institute of Railway Engineers

A special place in identifying the features of the vibrational process of ballast material, it is necessary to take, first of all, the nature of the process of oscillations. Its identification helps to determine the causes of their occurrence, which is very important for assessing the influence of oscillations on the properties and state of the ballast layer. Knowledge of the nature of the oscillatory process makes it possible in the future to simulate it in laboratory conditions to determine the degree of decrease in strength properties of ballast material, clogged sands under the influence of vibrodynamic load, during the …


Problem Of A Particle Solid Particles With A Ground Surface Airflow Formed Due To High-Speed Train Movement, Sh.S. Fayzibayev, R.Sh. Isanov, M.Sh. Valiyev Mar 2019

Problem Of A Particle Solid Particles With A Ground Surface Airflow Formed Due To High-Speed Train Movement, Sh.S. Fayzibayev, R.Sh. Isanov, M.Sh. Valiyev

Journal of Tashkent Institute of Railway Engineers

The paper deals with the problem of entrainment of particles by air flow with increasing speed of a high-speed train. We have obtained solutions to the problem in the case when the particles in the section have the shape of a trapezoid. If the speed of a high-speed train increases at the end of the train, a whirlwind may occur, which we will study