Engineering Commons^™

Thermal And Stress Analysis Of Nasa X-57 Maxwell Battery Pack, Bhumika Nautiyal

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Air travel has long been an established way of life for millions around the world, but innovation continues to push the boundaries of what is possible in the skies. While aviation has made it easy to travel long distances, the need to lower emissions from flights is pressing. The European Commission has described aviation as “one of the fastest-growing sources of greenhouse gas emissions.”

Airplanes release around 500 million tons of carbon dioxide into the atmosphere each year, representing a significant contribution to global warming. The very concept of a fossil-fuel-powered airplane needs to evolve to fully mitigate the impacts …

Experimental Comparison Between Hollow Cathodes With Cermet, Lanthanum Hexaboride, And Barium Oxide Insert Materials, Nagual Simmons

Masters Theses

This thesis compares two different hollow cathode assemblies (HCA) using three different insert materials. NASA’s Jet Propulsion Laboratory (JPL) provided the H6 HCA and the Lanthanum Hexaboride (LaB₆) insert. A barium oxide (BaO) insert was purchased from Ebeam and used with the H6 HCA. The novel Cermet material was purchased from Plasma Controls, LLC and the HCA was based on the JPL H6 HCA. Plasma properties in the external region of all three inserts and the internal region of the LaB₆ were determine using two separate Langmuir probes. Various operating points were tested at a combination of …

Security Services Using Blockchains: A State Of The Art Survey, Maeda Zolanvari, Aiman Erbad, Raj Jain, Mohammed Samaka

All Computer Science and Engineering Research

This article surveys blockchain-based approaches for several security services. These services include authentication, confidentiality, privacy and access control list (ACL), data and resource provenance, and integrity assurance. All these services are critical for the current distributed applications, especially due to the large amount of data being processed over the networks and the use of cloud computing. Authentication ensures that the user is who he/she claims to be. Confidentiality guarantees that data cannot be read by unauthorized users. Privacy provides the users the ability to control who can access their data. Provenance allows an efficient tracking of the data and resources …

State Measurement Spoofing Prevention Through Model Predictive Control Design, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Security of chemical process control systems against cyberattacks is critical due to the potential for injuries and loss of life when chemical process systems fail. A potential means by which process control systems may be attacked is through the manipulation of the measurements received by the controller. One approach for addressing this is to design controllers that make manipulating the measurements received by the controller in any meaningful fashion very difficult, making the controllers a less attractive target for a cyberattack of this type. In this work, we develop a model predictive control (MPC) implementation strategy that incorporates Lyapunov-based stability …

Thermal And Mechanical Response Of Inner Cone Sample Of Zrb₂-Sic Ceramic Under Arc-Jet Conditions, Jun Wei, Lokeswarappa R. Dharani, K. Chandrashekhara

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Under arc-jet test conditions, ZrB₂-SiC ceramic will undergo high temperature oxidation and develop an external glassy layer (SiO₂), zirconia sub-layer (ZrO₂) and SiC-depleted diboride layer (ZrB₂). This study relates to finite element modeling of the effects of oxidation on heat transfer and mechanical behavior of ZrB₂-SiC ceramic under arc-jet test conditions. A steady-state heat transfer FE method was employed to conduct the heat transfer analysis to obtain the temperature distribution in the inner body of the cone. The surface thermal conditions available in the literature were used in the heat …

Generation Of Transverse Photo-Induced Voltage In Plasmonic Metasurfaces Of Triangle Holes, Marjan Akbari, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We experimentally and numerically demonstrate the transverse electrical response produced by circularly-polarized light with normal incidence observed as transverse photoinduced voltage across the plasmonic metasurface made of triangle holes. The measured transverse photo-induced voltage is consistent with the calculated acting force on electrons in the metasurface by using the Maxwell's stress tensor. The polarity of voltage reverses as the incident spin (light helicity) switches from right-handed circular polarization to left-handed circular polarization. The origin of the spin-dependent voltage sign is the broken symmetries of the electric and magnetic fields in the triangle hole due to the opposite circular polarizations. The …

Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 1, A Thermal Circuit Network Model, Hao Peng, Morteza Ghasri-Khouzani, Shan Gong, Ross Attardo, Pierre Ostiguy, Bernice Aboud Gatrell, Joseph Budzinski, Charles Tomonto, Joel Neidig, M. Ravi Shankar, Richard Billo, David B. Go, David Hoelzle

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The additive manufacturing (AM) process metal powder bed fusion (PBF) can quickly produce complex parts with mechanical properties comparable to wrought materials. However, thermal stress accumulated during PBF induces part distortion, potentially yielding parts out of specification and frequently process failure. This manuscript is the first of two companion manuscripts that introduce a computationally efficient distortion and stress prediction algorithm that is designed to drastically reduce compute time when integrated in to a process design optimization routine. In this first manuscript, we introduce a thermal circuit network (TCN) model to estimate the part temperature history during PBF, a major computational …

Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One perceived cost of integrating winter cover cropping in maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems is the potential negative impact on soil water storage available for primary crop production. The objective of this 3-year study was to evaluate the effects of winter cover crops on soil water storage and cover crop biomass production following no-till maize and soybean rotations. Locations were near Brule (west-central), Clay Center (south-central), Concord (northeast), and Mead (east-central), Nebraska, United States. Treatments included crop residue only (no cover crop) and a multi-species cover crop mix, both broadcast-seeded before …

A Simple Method Of Coil Design, M. Rawlik, A. Eggenberger, J. Krempel, Christopher Crawford, K. Kirch, F. M. Piegsa, G. Quéméner

Physics and Astronomy Faculty Publications

In this article, we present a method to design a coil producing an arbitrarily shaped magnetic field by restricting the path of the coil's wires to a regular grid. The solution is then found by a simple least squares minimum. We discuss practical applications, in particular, in the active magnetic field stabilization system of the neutron electric dipole moment experiment at the Paul Scherrer Institute in Villigen, Switzerland. We also publish the software implementation of the method.

Modeling The Innovation Ecosystem And Development Of A Dynamic Innovation Index, Henriette Schoen

Electronic Theses and Dissertations

The topic of innovation currently generates a tremendous amount of interest around the world. Innovation is considered an essential part of the solution to creating more jobs and improving the socio-economic conditions of many countries around the globe. Innovation comes about through the existence of many interrelated solutions to socio-economic problems in an extensively interconnected network, which create value for each other. Such a complex creativity and innovation value-creating network is here called an Innovation Ecosystem (IE). The main objective of this dissertation research is to improve the current understanding of the IE by developing a simulation model that uses …

Methods For Online Feature Selection For Classification Problems, Alaleh Razmjoo

Electronic Theses and Dissertations

Online learning is a growing branch of machine learning which allows all traditional data mining techniques to be applied on an online stream of data in real-time. In this dissertation, we present three efficient algorithms for feature ranking in online classification problems. Each of the methods are tailored to work well with different types of classification tasks and have different advantages. The reason for this variety of algorithms is that like other machine learning solutions, there is usually no algorithm which works well for all types of tasks. The first method, is an online sensitivity based feature ranking (SFR) which …

Room Temperature Operation Of Quantum Cascade Lasers Monolithically Integrated Onto A Lattice-Mismatched Substrate, Rowel Go

Electronic Theses and Dissertations

Quantum Cascade Lasers (QCLs) are semiconductor devices that, currently, have been observed to emit radiation from ~ 2.6 μm to 250 μm (1 to 100 terahertz range of frequencies.) They have established themselves as the laser of choice for spectroscopic gas sensing in the mid-wavelength infrared (3-8 μm) and long-wavelength infrared (8-15 μm) region. In the 4-12 μm wavelength region, the highest performing QCL devices, in terms of wall-plug efficiency and continuous wave operation, are indium phosphide (InP) based. The ultimate goal is to incorporate this InP-based QCL technology to silicon (Si) substrate since most opto-electronics are Si-based. The main …

Shape Optimization Of A Fan Duncte For A Vertical Takeoff And Landing, Jie Hua

Mechanical and Aerospace Engineering Theses - Archive

The popularity of ride sharing services and recent improvements in electric car performance and automation have sparked interest in E-VTOL (Electric Vertical Takeoff and Landing) aircraft for personal transportation. Companies such as Uber, Airbus and EHANG are currently researching such aircraft for transportation over short distances in crowded urban environments. A personal E-VTOL design based on a ducted fan concept is proposed and the vertical lift capability is optimized. A numerical optimization algorithm is coupled with a computational fluid dynamics (CFD) analysis code to perform shape optimization. The objective is to determine the internal and external duct shape that maximizes …

A Study Of Effect Of Bond Length On Bond Strength Using Transient Heat Transfer Analysis, Junaid Mohamed Baig

Mechanical and Aerospace Engineering Theses - Archive

It is important to understand the mechanical properties of the bonding between the adjacent layers of 3D printed parts build by fused deposition modeling. The bonding process is highly nonlinear and depends on various geometrical and thermal process parameters. This work aims to quantify the degree of bonding by calculating bond potential between the extruded layers using finite element heat transfer analysis. Successive transient analysis were carried out using this model by constantly updating the boundary conditions and geometric model during the deposition of the extruded bead. Temperatures at critical points were calculated over a period to calculate the bond …

Inverse Analysis Of Heat Generating Body For Safety Applications, Sandeep Patil

Mechanical and Aerospace Engineering Dissertations - Archive

Inverse thermal analysis and its applications have been applied to numerous fields of science and engineering. Historically during the 1950's and early 1960's, space programs played a significant role in the advancement of solution techniques for Inverse Heat transfer Problems(IHTP). It was applied to measure the surface temperature of thermal shield of a space vehicle during its re-entry into atmosphere. Inverse analysis was also used in the estimation of thermo-physical properties of the shield at high operating temperatures. Besides thermal application, inverse technique was also used in other engineering applications such as estimation of alloy specification, design of a shape …

Optimization Of Board Level Reliability Of Microelectronic Packages And Modules, Alok Kumar Lohia

Mechanical and Aerospace Engineering Dissertations - Archive

Thermo-mechanical reliability estimation of electronic packages and modules provides an opportunity to predict the function life of semiconductor devices. The problem complexity lies in the fact that there are variety of electronic packages with different form factors, materials and manufacturing technology for various applications. The custom PCB ranges from very thin for portable application to very thick for power application. Despite conventional understanding and prior studies, some of the failures were not explained. This study reviews three failure problems for QFN, WCSP and BGA packages by characterizing the properties of custom PCB materials by layer removal process. Due to layup …

Design And Evaluation Of High Efficiency Power Converters Using Wide-Bandgap Devices For Pv Systems, Fahad Almasoudi

Electronic Theses and Dissertations

The shortage of fossil resources and the need for power generation options that produce little or no environmental pollution drives and motivates the research on renewable energy resources. Power electronics play an important role in maximizing the utilization of energy generation from renewable energy resources. One major renewable energy source is photovoltaics (PV), which comprises half of all recently installed renewable power generation in the world. For a grid-connected system, two power stages are needed to utilize the power generated from the PV source. In the first stage, a DCDC converter is used to extract the maximum power from the …

On Wlan Fingerprint Indoor Positioning Systems Clustering, And Classification For Enhanced Performance, Haider G. Al Glehawi

Masters Theses

The most economic and affordable IPS are those incorporating existing infrastructure, such as the widely spread Wireless Local Area Network (WLAN). The Received Signal Strength (RSS) fingerprinting-based system is one of the most promising and powerful techniques so far to be used for indoor positioning. However, there are two challenges in using RSS based IPS; the first challenge is the variation of RSS to indoor multipath propagation, and the second is the high number of Access Points (APs) that are deployed in the region of interest. The first issue leads to degradation in the performance of RSS based IPS, while …

Control-Oriented Automatic Transmission- Based Powertrain Modeling And Simulation With Judder, Harshal B. Kundale

Masters Theses

This work presents automatic transmission-based powertrain modeling. The powertrain consists of an engine, torque converter with lock up clutch, transmission gearbox, propeller shaft, and vehicle body. Simplified powertrain component models are developed for vehicle powertrain dynamic response analysis and future control work. The powertrain components are modeled with algebraic and first order non-linear differential equations. A MATLAB-based powertrain simulation system is developed to investigate the transient characteristics during lock up of torque converter. Simulation results are used in the determination of effects of judder on torque and angular velocity. Clutch judder is a self-excited vibration that occurs during the clutch …

Maintaining Deck Profile In Steel I-Girder Bridges During Deck Placement, Ali Naif Inceefe

Masters Theses

Conventional steel I-girder highway bridges utilize cast-in-place concrete deck. Maintaining the deck profile as per project specifications might be a challenging task. Deformation of girders and formwork used for deck placement need to be controlled during deck placement. Differential deflection between girders, exterior girder web out-of-plane deformation, exterior girder warping, or a combination thereof could impact the deck profile. These deformations challenge maintaining deck profile and need to be considered as a part of constructability evaluation. Determining deck profile due to potential girder deformations is necessary before deck placement so that the remedial actions can be implemented when deck finish …

Large Scale Cryogenic Storage With Active Refrigeration, Adam Swanger

Electronic Theses and Dissertations

Storage and transfer of cryogenic liquefied gases on volume scales from under 10 liters for lab use, up to hundreds of millions of liters for industrial applications is of paramount importance across a vast range of industries. Traditionally, these commodities have been stored at or near the normal boiling point due to relative ease of operation and safety-related considerations; however, this also means that some percentage will always be lost due to environmental heat leaking into the vessel and causing boiloff. These losses become more concerning as scales increase, and are of particular importance for high-cost commodities such helium and …

Comparison Of A Modified And Traditional Rapid Infiltration Basin For Treatment And Control Of Nutrients In Wastewater Effluent, Jessica Cormier

Electronic Theses and Dissertations

Rapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water disposal. Few, if any, studies have been published where BAM-modified RIBs have been used for this purpose. In this work, a mixture of clay, tire crumb, …

Autonomous Discovery And Maintenance Of Mobile Frees-Space-Optical Links, Mahmudur Khan

Electronic Theses and Dissertations

Free-Space-Optical (FSO) communication has the potential to play a significant role in future generation wireless networks. It is advantageous in terms of improved spectrum utilization, higher data transfer rate, and lower probability of interception from unwanted sources. FSO communication can provide optical-level wireless communication speeds and can also help solve the wireless capacity problem experienced by the traditional RF-based technologies. Despite these advantages, communications using FSO transceivers require establishment and maintenance of line-of-sight (LOS). We consider autonomous mobile nodes (Unmanned Ground Vehicles or Unmanned Aerial Vehicles), each with one FSO transceiver mounted on a movable head capable of scanning in …

Application Of Nano-Plasmonics For Sers Bio-Detection And Photocatalysis In The Same Platform, Muhammad R. Shattique

Graduate Theses/Dissertations

Nano-biological systems interfacing nano-structured solid surfaces with biological compounds such as oligonucleotides or proteins are highly regarded as enabling materials for biosensing and biocatalysis applications. In particular, nanostructures of noble metals such as gold or silver, when exposed to light, exhibit a phenomenon known as surface plasmon resonance. When a proper metal nanostructure (plasmonic substrate) is exposed to light, very efficient absorption of incoming photons is possible, resulting in a buildup of localized high-energy regions, or “hot-spots”, where energetic carriers or “hot carriers” can be created. These hot-carriers can be used to catalyze desired chemical transformations in materials located nearby. …

Systems Engineering Design Of An Electronically Interactive Application For Runway Incursion Prevention, Yixuan Cheng

Doctoral Dissertations and Master's Theses

Runway Incursion is the leading cause of serious incidents or accidents in airports. One of the most common causes of a runway incursion is airport unfamiliarity. Therefore, the researcher designed an electronically interactive application as a practice tool for pilots to utilize during flight preparation. The objective of this application is to enhance airport familiarity to ultimately reduce runway incursion. This application is interactive, affordable, accessible, and mobile device-based. It was designed using the Systems Engineering approach, following Human Factors Engineering principles to make this application user-friendly and to provide optimized human machine interaction. A model-based Systems Engineering software-CORE was …

Evaluation Of Airline Efficiency And Environmental Impacts Using Data Envelopment Analysis, Arun Paul Saini

Doctoral Dissertations and Master's Theses

Airline efficiency has been a focus of research since the birth of the airline industry. Data envelopment analysis has become a highly accepted methodology for performing efficiency analysis and assessing relative differences between comparable business entities; over the last decade, airline efficiency research has proliferated into this linear programming domain. While early airline efficiency research focused primarily on revenue generation and profitability, growing commercial social responsibility is driving greater investment into understanding and improving the environmental impact of airline operations. This study is intended to partially fill a gap in exigent literature. While limited data envelopment analysis including environmental impacts …

Prediction Of Airport Arrival Rates Using Data Mining Methods, Robert William Maxson

Doctoral Dissertations and Master's Theses

This research sought to establish and utilize relationships between environmental variable inputs and airport efficiency estimates by data mining archived weather and airport performance data at ten geographically and climatologically different airports. Several meaningful relationships were discovered using various statistical modeling methods within an overarching data mining protocol and the developed models were tested using historical data. Additionally, a selected model was deployed using real-time predictive weather information to estimate airport efficiency as a demonstration of potential operational usefulness.

This work employed SAS® Enterprise Miner TM data mining and modeling software to train and validate decision tree, neural network, and …

Parametric Study Of Aerodynamic Performance Of An Airfoil With Active Circulation Control Using Leading Edge Embedded Cross-Flow Fan, M.A. Qayyum Mazumder

Doctoral Dissertations and Master's Theses

A concept of a cross-flow fan (CFF) embedded near the leading edge of an airfoil to actively control the boundary layer for lift and thrust enhancement has been proposed. The design places a cross-flow fan near the leading edge of an airfoil and flow is drawn in from the pressure side of the airfoil, energized and expelled out to the suction side near the leading edge. This CFF system simulates the active boundary layer control by blowing commercial computational fluid dynamics (CFD) code ANSYS Fluent is employed to perform 2-D calculations based on various parameters of the CFF and compared …

Development To A Flexible Surface Acoustic Wave Sensor For Strain Sensing, Neha Vedavathi Ramachandran

Doctoral Dissertations and Master's Theses

Surface acoustic wave (SAW) sensors have increasing demand in structural health monitoring due to their passive, variable bandwidth, reliable life-cycle, high accuracy, small size, and light nature. SAW sensors can not only provide the static states of the structural system, such as temperature and pressure but also enable continuous real-time monitoring of dynamic states including strains. SAW sensors are generally fabricated with a rigid piezoceramic substrate, incapable of adapting to highly curved surfaces or flexible objects. The ongoing demands of sensor adaptability with flexible substrates, which is also capable of wireless monitoring, is the basis of the research that can …

Feasibility Of Aerial Tramway At Boise State University, Majed Alsaqyani

Boise State University Theses and Dissertations

The use of aerial tramways is becoming common in cities as a way to provide reliable, safe, sustainable, and cost-effective mass transportation. The aerial tramway is especially effective in the most congested areas of major cities. The growth of Boise State University (BSU) and downtown Boise makes this location especially attractive for a tramway. Moreover, based on data collected for this analysis, it is clear that the BSU community is open to using the tramway instead of more traditional modes of transportation.

The viability of the tramway is further enhanced because the computer science department has moved to City Center …