Engineering Commons^™

Effect Of Temperature On Early‐Age Properties Of Self‐Consolidating Concrete Equivalent Mortar, Nima Farzadnia, Jing Pan, Kamal Khayat, Eric Wirquin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the effect of ambient temperature during casting on fresh properties, hydration kinetics, and early‐age compressive strength of self-consolidating concrete (SCC) was evaluated. Concrete equivalent mortars (CEMs) with water‐to‐binder ratios of 0.41 and 0.45 were cast based on SCC mixture designs for building and infrastructure construction and precast applications. The CEMs were prepared at temperatures ranging from 8 to 36°C. Superplasticizer (SP) and air‐entraining agent (AEA) demand were evaluated for the CEM mixtures made with different supplementary cementing material (SCM) and limestone filler types. Test results showed that the ambient temperature can significantly affect the SP and AEA …

Securing User Interaction Channels On Mobile Platform Using Arm Trustzone, Amit Ahlawat

Dissertations - ALL

Smartphones have become an essential part of our lives, and are used daily forimportant tasks like banking, shopping, and making phone calls. Smartphones provide several interaction channels which can be affected by a compromised mobile OS. This dissertation focuses on the user interaction channels of UI input and audio I/O. The security of the software running on smartphones has become more critical because of widespread smartphone usage. A technology called TEE (Trusted Execution Environment) has been introduced to help protect users in the event of OS compromise, with the most commonly deployed TEE on mobile devices being ARM TrustZone.

This …

Discrete-Time Stable Geometric Controller And Observer Designs For Unmanned Vehicles, Reza Hamrah

Dissertations - ALL

In the first part of this dissertation, we consider tracking control of underactuated systems on the tangent bundle of the six-dimensional Lie group of rigid body motions, SE(3). We formulate both asymptotically and finite-time stable tracking control schemes for underactuated rigid bodies that have one translational and three rotational degrees of freedom actuated, in discrete time. Rigorous stability analyses of the tracking control schemes presented here guarantee the nonlinear stability of these schemes. The proposed schemes here are developed in discrete time as it is more convenient for onboard computer implementation and ensures stability irrespective of the sampling period. A …

Reinforcement Learning For Mobile Robot Collision Avoidance In Navigation Tasks, Zilong Jiao

Dissertations - ALL

Collision avoidance is fundamental for mobile robot navigation. In general, its solutions include: {\it map-based} and {\it mapless approaches.} In the map-based approach, robots pre-plan collision-free paths based on an environment map and follow their paths during navigation. On the other hand, the mapless approach requires robots to avoid collisions without referencing to an environment map. This thesis first studies the map-based approach for multiple robots to collectively build environment maps. In this study, a robot following a pre-planned path may encounter unexpected obstacles, such as other moving robots and obstacles inaccurately presented on an environment map. This motivates us …

User Authentication Across Devices, Modalities And Representation: Behavioral Biometric Methods, Amith Kamath Kamath Belman

Dissertations - ALL

Biometrics eliminate the need for a person to remember and reproduce complex secretive information or carry additional hardware in order to authenticate oneself. Behavioral biometrics is a branch of biometrics that focuses on using a person’s behavior or way of doing a task as means of authentication. These tasks can be any common, day to day tasks like walking, sleeping, talking, typing and so on. As interactions with computers and other smart-devices like phones and tablets have become an essential part of modern life, a person’s style of interaction with them can be used as a powerful means of behavioral …

4d Printing Shape Memory Polymers For Biomedical Applications, Kathleen Pieri

Dissertations - ALL

The development of 3D printing techniques using shape-memory polymers (SMPs) hascreated potentials for creating dynamic, three-dimensional structures that can be produced rapidly and be customized for specific and complex architectures. These qualities have made 3D printing a popular fabrication method for future SMP parts and devices. While important information about is known about the effects of printing parameters on 3D printed SMPs, there remains a gap in the understanding of these parameters on fundamental shape memory properties. Understanding the shape memory behavior of the SMPs post-printing can implicate potential advantages or weaknesses in using these materials in biomedical applications. Furthermore, …

Learning Semantic Information From Multimodal Data Using Deep Neural Networks, Krittaphat Pugdeethosapol

Dissertations - ALL

During the last decades, most collective information has been digitized to form an immense database distributed across the Internet. This can also be referred to as Big data, a collection of data that is vast in volume and still growing with time. Nowadays, we can say that Big data is everywhere. We might not even realize how much it affects our daily life as it is applied in many ways, ranging from online shopping, music streaming, TV streaming, travel and transportation, energy, fighting crime, to health care. Many organizations and companies have been collecting and analyzing large volumes of data …

Model-Based Approach For Product Requirement Representation And Generation In Product Lifecycle Management, Omer Yaman

Dissertations - ALL

The requirement specification is an official documentation activity, which is a collection of certain information to specify the product and its life-cycle activities in terms of functions, features, performance, constraints, production, maintenance, disposal process, etc. It contains mainly two phases; product requirement generation and representation. Appropriate criteria for the product design and further life-cycle activities are determined based on the requirement specification as well as the interrelations of product requirements with other life-cycle information such as; materials, manufacturing, working environments, finance, and regulations. The determination of these criteria is normally error-prone. It is difficult to identify and maintain the completeness …

Wrinkling Patterns On Curved Surface With Gradient Curvature Under Compression, Xiaoxiao Zhang

Dissertations - ALL

This work focuses on understanding the wrinkling patterns on a curved surface, i.e., tori and cones, with varying curvatures and global deformation. By tuning the geometry confine-ment and material properties, we can control the surface morphologies in these systems which can potentially be applied to wide applications in bio-inspired devices, microfluidic, and optical.

First, we investigate the wrinkles on a tri-layer torus consisting of an expanding thin outer layer, an intermediate soft layer, and an inner core with a tunable shear modulus. This study is inspired by pattern formations and evolutions in developmental biology, such as follicle pattern formation during …

Application Of Wavelet Transform To Endurance Time Analysis Method For Performance-Based Seismic Design, Mohammadhossein Mamaghani

Dissertations - ALL

Earthquakes occur quite frequently around the world, but the number of reliable recorded ground motion data for a given site is often limited. In addition, the use of present methodologies to modify existing earthquake records to match site conditions could change the relationship between the recorded earthquake characteristics and their actual physical attributes. The result is that these modified earthquakes could have qualities not quite the same as those of the real earthquakes. Instead of using scaling and spectral matching of real earthquakes, artificial earthquakes capable of mimicking both the physical conditions and qualities of real earthquakes should be generated …

The Compressive And Flexural Strength Of Concrete Containing Recycled Waste Plastic, Isaiah Akinkunmi

Master of Science in Civil Engineering Theses

Annually, tons of plastic wastes end up in landfills and the oceans through indiscriminate dumping, constituting a major source of pollution to the environment and threat to human health and marine lives. It therefore necessitates an innovative strategy to help mitigate the environmental hazards caused by this pollution. A feasible eco-friendly strategy is by using granulated plastics, fibers or regrinds in concreting. This research explored the feasibility of this strategy by testing the compressive and flexural strengths of hardened concrete specimens containing varying percent of plastic aggregates used as partial replacement for fine aggregates. The compressive strength of specimens of …

Solar Photovoltaic Performance Monitoring: A Bibliometric Review, Research Gaps And Opportunities, Javed Sayyad, Paresh Nasikkar

Library Philosophy and Practice (e-journal)

Electrical power generation has been revolutionized by growing demand and use of Renewable Energy (RE) sources such as Solar Photovoltaic (SPV) as the main electricity source in modern times. The main objective of this bibliometric analysis is to understand the scope of the literature available for SPV performance characterization. This detailed reviewed was performed on the documents related to SPV research considering all the subject categories from Scopus and Web of Science (WoS) databases. The patterns for the particular set of keywords were broke down with the recuperated outcomes from Scopus database in the language, publication type, year of publication, …

Feasibility Study Of A Micro-Electro-Mechanical-Systems Threshold-Pressure Sensor Based On Parametric Resonance: Experimental And Theoretical Investigations, Mark Pallay, Meysam Daeichin, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

A tunable threshold pressure sensor based on parametric resonance of a microbeam subjected to electrostatic levitation is proposed. Parametric excitation can trigger a large amplitude vibration at twice the natural frequency if the magnitude of the driving force is large enough to overcome energy loss mechanisms in the system such as squeeze film damping. This causes a temporarily unstable response with a significant gain in oscillation amplitude over time until it is eventually capped by nonlinearities in the force or material or geometric properties. The instability divides the frequency region into two regions: distinct responses bounded by the system non-linearity, …

Modeling And Simulation Of Morphological Instabilities In Thin Elastic Solids, Junbo Chen

Dissertations - ALL

The study of morphological instabilities in thin solids, such as buckling of thin shells and wrinkling of thin sheets, is of growing interest to a number of academic disciplines including en-gineering, physics, biology, and many others. For example, buckling has traditionally been re-garded as an unfavorable phenomenon in engineering design, but emerging technologies con-sider such behavior as an opportunity for novel functionality. The formation of wrinkle patterns on thin sheets has also emerged rapidly as canonical problems to investigate pattern formation in the physics community. The nonlinearities of the post-buckling behaviors encountered in these problems make theoretical analysis a challenging …

Cardiac Organoid Technology And Computational Processing Of Cardiac Physiology For Advanced Drug Screening Applications, Plansky Hoang

Dissertations - ALL

Stem cell technology has gained considerable recognition since its inception to advance disease modeling and drug screening. This is especially true for tissues that are difficult to study due to tissue sensitivity and limited regenerative capacity, such as the heart. Previous work in stem cell-derived cardiac tissue has exploited how we can engineer biologically functional heart tissue by providing the appropriate external stimuli to facilitate tissue development. The goal of this dissertation is to explore the potentials of stem cell cardiac organoid models to recapitulate heart development and implement analytical computational tools to study cardiac physiology. These new tools were …

Amplifier Architectures For Wireless Communication Systems, Mehmet Kok

Dissertations - ALL

Ever-increasing demand in modern wireless communication systems leads researchers to focus on design challenges on one of the main components of RF transmitters and receivers, namely amplifiers. On the transmitter side, enhanced efficiency and broader bandwidth over single and multiple bands on power amplifiers will help to have superior performance in communication systems. On the other hand, for the receiver side, having low noise and high gain will be necessary to ensure good quality transmission over such systems. In light of these considerations, a unique approach in design methodologies are studied with low noise amplifiers (LNAs) for RF receivers and …

Analysis And Behavior Of Segmented Energy Absorbing Steel Plate Shear Walls (Sea-Spsws), Nafiseh Shahbazi Majd

Dissertations - ALL

Conventional steel plate shear walls (SPSWs) are often designed to behave elastically under normal lateral load condition. However, they are expected to yield and absorb energy through inelastic hysteresis under extreme load condition. Depending on the width-to-thickness ratio and boundary conditions of these walls, SPSWs may also experience inelastic out-of-plane buckling. Therefore, maintaining structural integrity and preventing building collapse are dependent upon their post-buckling behavior. In this study, a new type of SPSW referred to as the Segmented Energy Absorbing Steel Plate Shear Wall (SEA-SPSW) is proposed and its behavior is investigated.The proposed steel plate shear wall is segmented into …

Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases, Shokhrukh Khojiev

Acta of Turin Polytechnic University in Tashkent

The article analyzes the scientific problems of the copper industry. In particular, the main problem with the classical production of copper is the causes of large amounts of slag and the negative impact of these wastes on the environment. Accordingly, the main component that forms the slag is iron, and the higher its content in the original copper concentrate, the more slag is formed, and at the same time a large amount of copper metal is released into the waste. The departure is indicated by evidence. To prevent this problem, a technology has been proposed to reduce copper sulfide concentrates …

Specific Features Of Optical Fiber Cable Operation During Tension And Change Of Ambient Temperature, Dilmurod Davronbekov, Zafar Khakimov

Bulletin of TUIT: Management and Communication Technologies

This article examines the effect of longitudinal and thermoelastic deformation of an optical module on the technological reserve of an optical fiber. Analytical expressions are given for determining the lower limit of the technological margin of an optical fiber for various types of fiber-optic cable section along the axis.

Effect Of Microcapsule Content On Diels-Alder Room Temperature Self-Healing Thermosets., Sadella C Santos, John J La Scala, Giuseppe R Palmese

Henry M. Rowan College of Engineering Departmental Research

A furan functionalized epoxy-amine thermoset with an embedded microcapsule healing system that utilizes reversible Diels-Alder healing chemistry was used to investigate the influence of microcapsule loading on healing efficiency. A urea-formaldehyde encapsulation technique was used to create capsules with an average diameter of 150 µm that were filled with a reactive solution of bismaleimide in phenyl acetate. It was found that optimum healing of the thermoset occurred at 10 wt% microcapsule content for the compositions investigated. The diffusion of solvent through the crack interface and within fractured samples was investigated using analytical diffusion models. The decrease in healing efficiency at …

Exploring A Platinum Nanocatalytic Microcombustion-Thermoelectric Coupled Device, Dylan Moore Mcnally

Theses and Dissertations

This work aimed to create a first-generation power device for eventual application to portable electronics. A platinum nanoparticle catalytic substrate was employed in a microcombustion-thermoelectric coupled (MTC) device for the purpose of chemical-to-electrical energy conversion. Multiple microcombustion reactors were designed, fabricated, and investigated. Most importantly, the reactor configuration was designed to accommodate thermoelectric generators (TEGs) for power production. Temperature studies with catalytic combustion of methanol-air fuel mixtures were used to evaluate the thermal power generation performance of each reactor. The final reactor design enabled ignition at room temperature with the ability to achieve repeat catalytic cycles upon subsequent exposure to …

Spectral Absorption Coefficient Of Additive Manufacturing Materials, Nicholas J. Wallace, Matthew R. Jones, Nathan B. Crane

Faculty Publications

Active thermography techniques are of interest for quality assurance of additive manufacturing processes. However, accurate measurements of thermophysical properties of materials are required to successfully implement active thermography. In particular, the spectral absorption coefficient of materials commonly used in additive manufacturing must be known to accurately predict the spatial distribution of thermal energy generated from absorption of power emitted by a laser or pulsed flash lamp. Accurate measurements of these optical properties are also needed to develop greater understanding of additive manufacturing processes that rely on radiative heat transfer to fuse powders. This paper presents spectral absorption coefficient measurements and …

Modified C-17 Taxi Procedures: A Fuel Cost Savings Exploration, Michael Wells, Michael Krester, Benjamin Hazen, Jeffery D. Weir

Faculty Publications

Purpose — This study aims to explore the viability of using C-17 reduced-engine taxi procedures from a cost savings and capability perspective. Design/methodology/approach — This study model expected engine fuel flow based on the number of operational engines, aircraft gross weight (GW) and average aircraft groundspeed. Using this model, the research executes a cost savings simulation estimating the expected annual savings produced by the proposed taxi methodology. Operational and safety risks are also considered. Findings — The results indicate that significant fuel and costs savings are available via the employment of reduced-engine taxi procedures. On an annual basis, the mobility …

Effect Of Applied Pressure During Sintering On The Densification And Mechanical Properties Of Sicf/Sic Composites Prepared By Electrophoretic Infiltration, Alfian Noviyanto

Makara Journal of Science

SiC-fiber-reinforced SiC matrix ceramic (SiC_f/SiC) composites were successfully fabricated by electrophoretic infiltration and sintering at various applied pressures. The effect of applied pressure (i.e., 5, 10, and 20 MPa) was thoroughly examined, and applied pressure appears to influence the densification and mechanical properties of SiC_f/SiC composites. The densities of SiC_f/SiC composites prepared at applied pressure of 5, 10, and 20 MPa were 2.99, 3.10, and 3.16 g/cm³, respectively. All samples showed dense microstructures in their matrix areas; however, many closed pores were found with increasing pressure. Pressure induced densification in the fiber …

Effect Of Surfactant Addition On The Dispersion And Antioxidant Performance Of Pyrogallol In Biodiesel, Silvya Yusri, Mohammad Nasikin, Hery Sutanto

Makara Journal of Science

Biodiesel is one of the most feasible energy sources that can be used as a replacement for fossil fuel. Biodiesel has several advantages over conventional fuels because of its availability, renewability, and high combustion efficiency. However, biodiesel that contains unsaturated fatty acid methyl esters is prone to oxidation during the blending process and storage period. The complete oxidation reaction of biodiesel produces insoluble gums that could potentially plug the fuel engines. This reaction has become the main barrier for biodiesel to compete with other biofuels. Among several methods, the addition of antioxidants is the most cost-effective method to prevent the …

Improving The Maximum Power Point Tracking Efficiency Of Photovoltaic Arrays Via Machine Learning And Deep Learning, Sumedha Inamdar

Master of Science in Computer Science Theses

Under partial shading conditions, photovoltaic (PV) modules in a solar array experience varying irradiance. A Global Maximum (GM) and multiple Local Maximums (LMs) can originate on the Power-Voltage (P-V) curve under nonuniform irradiance conditions. There are many maximum power point tracking (MPPT) algorithms developed to detect the true maximum power point (MPP) of a PV array. However, in the real-world environment, limited samples of power-voltage (P-V) data might be available to quickly and accurately predict the position of the global maximum point. Since the change of environmental conditions are dynamic, limited time is available to locate the global peak. Machine …

Comparing Greedy Constructive Heuristic Subtour Elimination Methods For The Traveling Salesman Problem, Petar Jackovich, Bruce A. Cox, Raymond R. Hill

Faculty Publications

Purpose — This paper aims to define the class of fragment constructive heuristics used to compute feasible solutions for the traveling salesman problem (TSP) into edge-greedy and vertex-greedy subclasses. As these subclasses of heuristics can create subtours, two known methodologies for subtour elimination on symmetric instances are reviewed and are expanded to cover asymmetric problem instances. This paper introduces a third novel subtour elimination methodology, the greedy tracker (GT), and compares it to both known methodologies. Design/methodology/approach — Computational results for all three subtour elimination methodologies are generated across 17 symmetric instances ranging in size from 29 vertices to 5,934 …

Advanced Thermal Characterization And Temperature Control To Enable The Next Generation Of Micro-Electronic Technologies, Assaad El Helou

Mechanical Engineering Research Theses and Dissertations

In the electronics world, self-heating is an inevitable by-product of electrical activation that has a major impact on device performance and reliability. Thermal technologies have been in constant development to effectively dissipate the generated heat and keep device operation temperatures within reliable limits. Moreover, thermal characterization technologies have been implemented to understand the thermal performance within microelectronic sys- tems, but not without facing experimental and numerical challenges. This work presents ad- vanced thermal investigations, both experimental and numerical, that are adapted and most suited for emerging micro-electronic technologies. Initially, the main experimental and numerical modeling challenges faced in the thermal …

Microparticle Propulsion For In Vivo Navigation, Louis Rogowski

Mechanical Engineering Research Theses and Dissertations

Microscale propulsion impacts a diverse array of fields, with simplistic microrobots allowing for novel innovations in microscale surgery and drug delivery. Propulsion at the microscale is constrained by physics, with time-reversal and geometric symmetries limiting available propulsion mechanisms. However, certain fluid environments and surface coatings allow for the propulsion of microparticles through externally applied magnetic fields. Presented here is a detailed analysis of microparticles propelling using spontaneous symmetry breaking, flagella surface coatings, and multi-modal actuation mechanisms. Spontaneous symmetry breaking in nonlinearly viscoelastic fluids is presented for the first time in literature, with two equal and opposite propulsion states existing along …

The Effect Of Surface Air Entrapment On Oscillating Fin Flow At Intermediate Reynolds Number, Nicholas Davis

Mechanical Engineering Research Theses and Dissertations

Oscillating fin flow has been a subject of study due to its simplicity and similarity to aquatic propulsion methods found in nature. At intermediate Reynolds numbers, in the range of 10 to 1000, drag tends to have a larger impact than at higher Reynolds numbers and the boundary layer thickness on the fin surface tends to be larger, which can alter the vortices shed during oscillation. To attempt to reduce these effects, an apparent slip condition may be placed on the surface of the fin. In this investigation, entrapment of pneumatically supplied air at a perforated fin surface was used …