Engineering Commons^™

Laminar Swept And Cross Shockwave/Boundary-Layer Interactions, Jiss Jacob Sebastian

Mechanical and Aerospace Engineering Dissertations - Archive

Shockwave/boundary-layer interactions are considered one of the most complex problems in high-speed gas dynamics, and numerous studies have been carried out for more than eighty years to understand the fundamental physics. A numerical study was performed using fin-plate configurations to study the three-dimensional swept and cross shockwave/ laminar boundary-layer interactions. All the interactions studied were strong enough for the boundary layer to separate. In the first part, swept shock interactions between a laminar boundary layer and the shockwave induced by a sharp fin mounted perpendicularly on a flat plate were studied. Different flow conditions were investigated at freestream Mach numbers …

Design, Operation And Maintenance Of Direct And Indirect Evaporative Cooling Systems In Data Center Thermal Management, Ashwin Siddarth

Mechanical and Aerospace Engineering Dissertations - Archive

Evaporative cooling is an alternative data center cooling solution that presents significant energy cost savings in acquisition and operation when compared to conventional air conditioning and mechanical refrigeration systems. This research focuses on developing a deeper understanding in implementing, operating and maintaining evaporative cooling systems integrated with air-side economization to realize the energy savings potential in data center cooling. The goal of the research is to develop a comprehensive guide to assess and contrast different approaches of evaporative cooling being used in data center cooling and provide guidance in improving water and energy efficiency. An air handling unit (AHU) serves …

Design Of Streamline-Traced Inlets And Their Integration With Rotating Detonation Engines, Malcolm Lee Branch

Mechanical and Aerospace Engineering Theses - Archive

This thesis has two parts: 1) design of the streamline-traced inlets (STIs); and 2) integration of STIs with rotating detonation engines (RDEs). The STI design starts with a two-dimensional, isentropic compression flowfield as the parent flowfield. The method of characteristics was used to generate the flowfield throughout the entire STI. For a given flight altitude 18 km, freestream Mach number M?=3.0, and inlet exit-plane Mach number M?=1.2, a parametric sweep of the initial deflection angle ?1=4.0--11.0 deg and the Mach number at the entrance of the internal compression system M3=1.3--1.7 was performed to determine the STI performance sensitivity as a …

Haptic Interface Optimization For Virtual Anastomosis Surgery Training, Kangji Huang

Mechanical and Aerospace Engineering Theses - Archive

Virtual anastomosis surgery study allows surgeons to perform or practice suturing in virtual reality using a commercial haptic device. The haptic device can generate force feedback so that the user can feel the real touch sensation of the object in virtual reality. The virtual anastomosis surgery study has two requirements which are that the haptic device must be fixed on the operating table and haptic device location must be suitable for different surgeons. The goal is to use a commercially available haptic device for this purpose, rather than design a new device for each possible surgery that must be performed. …

Design And Cfd Analysis Of Bimetallic Based Passive Dynamic Cold Plate For High Power Direct-To-Chip Liquid Cooling, Apurv Pravin Deshmukh

Mechanical and Aerospace Engineering Theses - Archive

Rising demand for high-performance chips results in the need for advanced and efficient cooling technologies like direct to chip liquid cooling. Cold plates based utilizing direct liquid cooling is one of the most efficient and the most investigated cooling technology since the 1980s. Major data services and cloud providers like IBM, Microsoft, and Google had already started a shift towards liquid-cooled data centers for their high computational servers. At the chip level nowadays, the processors are divided into several cores and each of these cores continuously works at varying computational demands. This creates a non-uniform heat distribution across the processor, …

Simulation Of A Soft Body Non-Grasp Manipulator Using A Spring-Mass-Damper Cloth Model, Cristian Almendariz

Mechanical and Aerospace Engineering Theses - Archive

Simulation and modeling are well known and important tools in the field of robotics, being used to validate design and in the development of robotic control systems. Traditionally, robotic systems have been primarily rigid body systems and used in well controlled environments where interactions are highly predictable, and exceptions are minimized. With the ever-increasing adoption of robotics in the medical field, typical robotic environments are becoming highly unpredictable and requiring the modeling and simulation of not only rigid body systems but soft systems and interactions between the two. This work addresses model improvement of a “soft and hard” robotic system …

Development Of Virtual Simulation For Evaluation Of Robotic Assistive Environment, Shubham Raosaheb Gunjal

Mechanical and Aerospace Engineering Theses - Archive

Robotics research in virtual simulation has the advantage of reduced testing time, verification of algorithms on different systems before implementation, and cost-saving. Today’s simulation softwares are capable of providing the physics of the simulation such as torque requirements of the joints which aid in the selection of appropriate hardware. In this research, Webots, an open-source physics-based simulation, and visualization software is evaluated and then used to study and evaluate the performance of two robotic systems for a robotic assistive environment for persons with upper limb disabilities. This includes a wheelchair, a table with objects, and two robotic arms attached to …

Investigating A Finite Element Model Updating Methodology For Characterizing Mechanical Properties Of Ncf Composites, Pasworn Chanchai

Mechanical and Aerospace Engineering Theses - Archive

Composite materials have been a key breakthrough in developing aircraft structures. Their superior strength and stiffness-to-density ratio, which are unmatched by no other materials, allow engineers to create high strength and ultra-lightweight aircraft structures. Recently, non-Crimp Fabric (NCF) composites have emerged as attractive alternatives to traditional autoclave pre-impregnated composites allowing for lower production costs, better handling and improved shelf life while maintaining excellent in-plane mechanical properties compared to other types of textile composites. NCF out-of-plane mechanical properties can also be enhanced by stitching a high tensile strength yarn throughout their entire laminate thickness, improving the resistance to delamination. However, stitch-reinforced …

Surface Modification Of Titanium By Electrolytic Plasma Processing And In-Vitro Studies, Wisanu Boonrawd

Material Science and Engineering Dissertations - Archive

Electrolytic plasma processing (EPP) can be operated in two modes, namely plasma electrolytic saturation (PES) and plasma electrolytic oxidation (PEO). In this study, the PES was used to create hydrophilic surface profiles on titanium (Ti). The wettability, surface morphology characteristics and chemical composition of the treated samples were studied as a function of PES processing parameters. The PES profiled surfaces comprised of a characteristic “hills and valleys” morphology because of continuous surface melting and freezing cycles. A bimodal surface profile was produced with 2-3 µm height hills and valleys with nano-roughness (= 200 nm). The produced profile resulted in a …

Poly(Lactic-Co-Glycolic Acid) Nanoparticle Delivery Of Notch Intracellular Domain Plasmid To Restore Notch Signaling, Victoria L. Messerschmidt

Bioengineering Dissertations - Archive

Notch signaling is a highly conserved signaling system that is required for embryonic development and regeneration of organs. When the signal is lost, maldevelopment occurs and leads to a lethal state. Delivering exogenous genetic materials encoding Notch into cells can reestablish downstream signaling and rescue cellular functions. Here, we utilized the negatively charged and FDA approved polymer poly(lactic-co-glycolic acid) to encapsulate Notch Intracellular Domain-containing plasmid in nanoparticles. We show that primary human umbilical vein endothelial cells (HUVECs) readily uptake the nanoparticles with and without specific antibody targets. We demonstrated in vitro that our nanoparticles are nontoxic, stable over time, and …

Utilizing Load Tests And Site Investigation Data To Predict Design Load Capacities For Drilled Shafts In Different Geologic Formations, Hosam Salman

Civil Engineering Dissertations - Archive

Precise predictions of the design capacities of drilled shafts on weak rock formations is vital for a better design of foundations. Irregularities in rock formations due to weathering cause discrepancies in actual bearing capacities and evaluating the bearing capacity typically requires frequent in-situ testing, using load test shafts at smaller intervals, which is time consuming and expensive. The typical design in Texas currently utilizes in-situ design charts that are developed based on Texas Cone Penetrometer (TCP) blow counts. This approach is found to have limitations related to maximum number of blows, rock characterization, and difficulty in incorporating influential parameters. Problematic …

Localized Treatment Of Malignant Melanoma Using A Modified Cellulose-Based Hydrogel Loaded With Temozolomide With Increased Safety Of Human Dermal Fibroblasts And The Mechanisms Behind The Effect, Joseph Wolf

Bioengineering Dissertations - Archive

Melanoma pathophysiology is highly varied, and the initial cause of tumorigenesis is still unknown, but it is likely a combination of both epigenetic and genetic means. Further, melanoma tumors have one of the highest mutational burdens of all cancers and are largely composed of varied subpopulations within the same tumor. These two factors provide insight into why melanoma is so difficult to treat medicinally. Dacarbazine is the gold-standard of metastatic melanoma treatment, yet only has an overall response rate of 22% and no impact on survival. Temozolomide (TMZ), an analog of dacarbazine, is often viewed as a more ideal choice …

Evaluation Of A Personal Mobile Trainer System Designed For Facilitating Exercise Therapy For Traumatic Brain Injury Patients, Ahmad Fawzi G Turki

Bioengineering Dissertations - Archive

There are no effective pharmacological agents that can prevent or treat post-TBI cognitive deterioration. Previous research has shown that exercise can be an effective means of enhancing the patients condition with mild traumatic brain injury (TBI). However, compliance with the prescribed exercise regimen has been low, as TBI patients often suffer from poor executive function and need assistance with complying with their prescribed exercise program. This study aims to design, build, and test a system based on a wearable exercise tracker to assist and encourage patients by facilitating doing the prescribed exercises at a place and time that is convenient …

Porcine Neonatal Heart Extracellular Matrix As A Regeneration Platform, Karla Perez

Bioengineering Dissertations - Archive

Each year, an estimated 620,000 Americans have new heart attack and suffer from myocardial infarction (MI) that results in massive heart cell death and decrease in heart function. Various therapeutic strategies, such as pharmacological treatments and reperfusion strategies, have greatly improved short-term MI survival. However, these strategies do not restore normal cardiac function due to the permanent loss of cardiomyocytes. As a promising strategy, cardiac cell therapy delivers repairing cells to damaged areas (scar tissues) to revitalize the infracted heart. However, a key challenge in cardiac cell therapy, i.e. the extremely low survival and engraftment rate of transplanted cells, must …

Environmental And Health Implications Of Mine Tailing-Based Construction Materials In Developing Communities: Current Practices And Ways Forward, Jose Raul Velasquez Vasquez

Civil Engineering Theses - Archive

For many years, artisanal and small-scale mining (ASM) communities around the world have been developing strategies to reduce contaminated mine tailings produced by mineral processing operations. These mine tailings are the by-product of the physical and chemical processes required to extract metals that humans require every day. The strategies developed by these communities cover a wide range of solutions, such as better practices in mineral processing activities as well as alternative technologies that help reduce the environmental impact of mining. Specifically, the recycling of mine tailings to produce construction materials has been of interest to researchers and communities. The use …

A New Geothermal Bridge De-Icing System With Attached Hydronic Heating Loops: Field Tests, Numerical Modeling, And Economic Assessment, Omid Habibzadeh Bigdarvish

Civil Engineering Dissertations - Archive

Each year, ice and snow adversely impact U.S. transportation infrastructure during the cold season, causing an extensive impact on the U.S. economy. Bridges are key elements in the transportation network and the most vulnerable sections of the road to ice and snow. Conventional snow and ice removal system (CSRS) is proven not to be a satisfactory solution as it causes induced damages and issues, such as accelerating bridge deck corrosion, safety issues, travel delays, and environmental damages. Thus, the geothermal heat pump de-icing system (GHDS) is introduced as a sustainable solution for bridge deck de-icing, which utilizes renewable geothermal energy …

Further Development Of Ultra-High-Performance Fiber Reinforced Concrete (Uhp-Frc): 3d Printing, Sifcon, Alternative Fibers, Shrinkage Crack Control, High Temperature, And Lightweight, Bhupendra Raj Acharya

Civil Engineering Theses - Archive

Introduction of artificial intelligence (AI) and machine learning in manufacturing industry also in every service industry, decreasing conventional skilled workforce and stagnated construction industry, probability and past statistics of the accident at the construction sites and difficulty in quality control has led the researchers to think of the solution and alternatives of the conventional construction. A new construction paradigm, known as 3-D concrete printing or additive manufacturing of concrete (AMC) provides such a solution. This research focuses on a preliminary study in 3d printed ultra-high-performance fiber-reinforced concrete (UHP-FRC) and, has developed a novel mix that has balanced extrude-ability and buildability. …

Space-Charge Limited Current In Planar And Cylindrical Crossed-Field Diodes Using Variational Calculus, Adam M. Darr, Ranajoy Bhattacharya, Jim Browning, Allen L. Garner

Electrical and Computer Engineering Faculty Publications and Presentations

No abstract provided.

Characterization And Enhancement Of Mechanical Properties In Thermoplastic Fff Parts Using In-Situ Annealing, Rhugdhrivya Rane

Mechanical and Aerospace Engineering Dissertations - Archive

Fused filament fabrication is one of the most common and widely used additive manufacturing techniques. Owing to its ease of use, availability and cheap feedstock it provides a significant advantage over other AM techniques. But these advantages are overshadowed by the fact that FFF parts show high anisotropy and reduced mechanical properties as compared to conventional manufacturing techniques. Literature review of previous research works show multiple approaches to enhance the mechanical properties of FFF parts but each of these techniques have limitations to either the geometries that can be printed or involve complex expensive setups. In one such technique a …

Shape Modeling, Attitude Estimation, And Classification Of Artificial Resident Space Objects (Rso) Using Photometric Light Curves, Katiyayni Balachandran

Mechanical and Aerospace Engineering Dissertations - Archive

Light curve inversion (LCI) has proven valuable in using photometric measurements to optimize various physical parameters of a resident space object (RSO) such as rotational period about its own spin axis, pole orientation and others. Other characteristics such as shape and size are dependent on the surface brightness. To accurately determine size, shape, spin rate, or attitude information of an unresolved resident space object, photometry is required to capture the relatively rapid changes in brightness that these objects can exhibit. LCI has been developed significantly for asteroids, although not fool-proof for artificial RSOs. Satellites and space debris, unlike asteroids, are …

Theoretical And Experimental Analysis And Optimization Of Thermal Conduction In Electrochemical And Latent Heat Energy Storage Systems, Amirhossein Mostafavi

Mechanical and Aerospace Engineering Dissertations - Archive

Phase change materials (PCMs) are used commonly for energy storage purposes. Thermal energy can be stored in a PCM with a variety of configurations such as PCM slabs, cartesian and cylindrical finned systems. Heat transfer in PCM storage systems can be from a heat transfer fluid (HTF) or a heat source at constant temperature to adjacent PCM. The rate of heat transfer is limited by thermal properties. Fin insertion can improve the heat transfer inside the PCM. Chapters 2 and 3 derive and solve the governing energy equations to determine the transient temperature distribution in the PCM due to the …

Reusing Of Recycled Plastic As Pavement Base And Sub-Base Materials, Tanvir Imtiaz

Civil Engineering Dissertations - Archive

A large percentage of waste materials is recycled back into the same product from which they originated. In spite of considerable progress in recycling waste materials generated in urban environments, the materials are sometimes not able to be recycled into the same product due to their quality or technical requirements and are as a result dumped or incinerated. Recycling concrete aggregate (RCCA) and recycled waste plastics are examples of recycled materials that can be used as an alternative to natural aggregates during the construction of newer structures as well as demolition of existing structures like buildings, bridges, and pavements. Materials …

Causes Of Driver Distraction And Incidents At Signalized Intersections, Zannatulferdous Labony

Civil Engineering Dissertations - Archive

Driver distraction causes a major portion of motor vehicle crashes because distractions turn the driver’s attention away from driving the driving task, Intersections represent high risk environments because many conflict points within the intersection exist. At intersections with signalized traffic control, drivers may be more likely to become distracted than at other intersections. While distraction during the red indication may not seem to be a significant concern, this study investigates the role distraction plays in crashes at signalized intersections. Using the SHRP2 naturalistic driving study data, this study focuses on investigating the frequency and types of driver distraction, the causes …

Development Of Non-Prestressed Uhp-Frc Girders For Long-Span Bridges With Dcsr Design Concept And Collapse Assessment Of Smfs With Calibrated Rc And Uhp-Frc Columns Based On Full-Scale Experiments, Seyed Missagh Shamshiri Guilvayi

Civil Engineering Dissertations - Archive

The work presented here is divided in two parts. This summary includes two paragraphs, each summarizing the topics presented in this dissertation. Ultra-high-performance fiber-reinforced concrete (UHP-FRC) is an emerging material and revolutionarily utilize its mechanical properties can offer a new way to design conventional precast prestressed concrete girders. Its ultra-high compressive strength (> 20 ksi) accompanying by exceptional compressive ductility with a maximum useable compressive strain of 0.015–0.03 allow designers to use higher amount of reinforcement. Current design codes (ACI 318 Building Code and AASHTO LRFD Bridge Design Specifications), limits the maximum useable compressive strain, εcu, to 0.003 for conventional …

Rotor Performance Model (Rpm), Chadwick Scott Balfantz

Mechanical and Aerospace Engineering Theses - Archive

Rotorcraft performance modeling is of high interest with multiple industry codes in existence, many of which are high-fidelity and are comprehensive in the analyses that are achievable. Along with the high-fidelity and the comprehensive nature of the industry codes comes an equally high level of complexity in the inputs required to extract meaningful results. The ever-increasing fidelity in the existing codes creates a need for an analysis code that is built to be highly flexible, designed from the top down and implemented from the bottom up in a structured format. The Rotor Performance Model (RPM) was developed to provide high-fidelity …

Towards Real-Time Energy Efficiency Analysis Of A Hydraulic System, Montasir Mamun Mithu

Masters Theses

The study aims at developing a real-time data analysis system for the energy efficiency study of hydraulic systems. It also aims at implementing automation for hydraulic systems so that energy efficiency can be improved using the real-time approach. This research uses a system-level experimental methodology. A linear push system hydraulic prototype is developed for the study. The prototype contains hydraulic actuator, shock absorber, electronic flow control valve, and electronic sensor. This prototype is used to experiment with different operating conditions to characterize hydraulic system behavior. A real-time data analysis system is developed using LabVIEW and an Open Platform Communication (OPC) …

Development Of A Highly Sensitive Pressure Sensing System With Custom-Built Software For Continuous Physiological Measurements, Masoud Panahi

Masters Theses

In this work, a pressure sensing system was designed and fabricated by developing a highly sensitive cone-structured pressure sensor with a custom-built software for physiological monitoring applications. A novel highly sensitive cone structured porous polydimethylsiloxane (PDMS) based pressure sensor capable of detecting very low-pressure ranges was developed for respiration monitoring. The pressure sensor was fabricated using a master mold, a hybrid-structured dielectric layer, and fabric-based electrodes. The master mold with inverted cone structures was created using a rapid and precise three-dimensional (3D) printing technique. The dielectric layer, with pores and cone structures, was prepared by annealing a mixture of PDMS, …

Shape-Based Time Series Mining For Process Monitoring And Anomaly Detection, Li Zhang

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Due to the rapid development of computing and sensing technology, Internet of Things (IoT)-enabled monitoring plays a crucial role for people suffering from cardiac problems. It is important to detect the abnormal ECG cycles during the cardiac monitoring for the early treatment. However, most existing methods focused on the full reading of time series, for the cycle-based time series, it is wasting time to read the whole time series while we can find the characteristic patterns instead. Characteristic patterns named shapelets are time series subsequences, which are explainable and discriminative features that can best classify time series. Shapelet-based classification that …

Attracting Diverse Talent To The Engineering Professions Of 2030 Activity 1 Outcomes, Una Beagon

Conference Papers

As the world’s focus turns to the future and not the present, the engineering profession must respond to the ever increasing need to bring about a sustainable future. The objective of this paper is to support the reform of engineering education by acknowledging and building upon the current awareness and understanding of sustainable development held by key stakeholders in the process.

This paper presents the outcomes of a study involving twelve focus groups with Academics, Employers and Students in four European countries (Denmark, Finland, France and Ireland) as part of the A-STEP 2030 European Project. Based on the findings, it …

Credit Assignment In Multiagent Reinforcement Learning For Large Agent Population, Arambam James Singh

Dissertations and Theses Collection (Open Access)

In the current age, rapid growth in sectors like finance, transportation etc., involve fast digitization of industrial processes. This creates a huge opportunity for next-generation artificial intelligence system with multiple agents operating at scale. Multiagent reinforcement learning (MARL) is the field of study that addresses problems in the multiagent systems. In this thesis, we develop and evaluate novel MARL methodologies that address the challenges in large scale multiagent system with cooperative setting. One of the key challenge in cooperative MARL is the problem of credit assignment. Many of the previous approaches to the problem relies on agent's individual trajectory which …