Materials Science and Engineering Commons^™

Ii-Vi Type-Ii Quantum Dot Superlattices For Novel Applications, Vasilios Deligiannakis

Dissertations, Theses, and Capstone Projects

In this thesis, we discuss the growth procedure and the characterization results obtained for epitaxially grown submonolayer type-II quantum dot superlattices made of II-VI semiconductors. We have investigated the spin dynamics of ZnSe layers with embedded type-II ZnTe quantum dots and the use of (Zn)CdTe/ZnCdSe QDs for intermediate band solar cell (IBSC). Samples with a higher quantum dot density exhibit longer electron spin lifetimes, up to ~1 ns at low temperatures. Tellurium isoelectronic centers, which form in the ZnSe spacer regions as a result of the growth conditions, were also probed. A new growth sequence for type-II (Zn)CdTe/ZnCdSe (QDs) was …

Impact Of Team Formation Approach On Teamwork Effectiveness And Performance In An Upper-Level Undergraduate Chemical Engineering Laboratory Course, Erick S. Vasquez, Matthew J. Dewitt, Zachary J. West, Michael J. Elsass

Chemical and Materials Engineering Faculty Publications

This study focuses on the impact of team formation approach on teamwork effectiveness and performance spanning three years of instruction of the chemical engineering unit operations laboratory, which is an upper-level undergraduate laboratory course. Team formation approaches changed each year, and assessment tools, including peer-assessment, academic performance, and course evaluations, were employed to evaluate team performance. Approaches included three cases: instructor-selected teams based on GPA with the objective of a similar cumulative average GPA for each team, student self-selected teams, and a combination of self-selected teams with instructor-selected teams for a final experiment. For the third case, new teams were …

Performance Evaluation Of Lightweight Normal And Geopolymer Foamed Concrete Using Palm Oil Fuel Ash As Partial Replacement Of Binder, M .E. Alnahhal Ahmed

Student Works (2020-2029)

Carbon dioxide (CO2) emissions from Ordinary Portland Cement (OPC) have a detrimental effect on the environment and this had led many researchers to search for other alternatives in the form of sustainable cementitious materials. The depletion of natural resources and dumping the industrial by-products and waste materials are serious concern to our environment. This research focusses on the performance of using a palm oil industrial by-product, namely, palm oil fuel ash (POFA), as a partial replacement for OPC and fly ash (FA) in lightweight normal foamed concrete and lightweight geopolymer foamed concrete, respectively. Thus, using 10, 20, and 30% POFA …

Development Of Integrated Zinc Oxide Nanorods Coated Glass Substrate Sensing Device, Mohd Yusof Haziezol Helmi

Student Works (2020-2029)

A simple and practical cost-effective integrated zinc oxide (ZnO) nanorods coated glass substrate sensing device for humidity and formaldehyde vapor sensing applications is reported. The developed sensor device is composed of a commercial light-emitting diode (LED) and photodiode that correspondingly served as light source and detector which precisely positioned on a 3D printed sensor platform. A receiver circuit and Arduino platform were employed for signal amplification and processing. A uniform ZnO nanorods coating were grown on the surface of glass substrate via hydrothermal method by controlling the growth durations and coating length. A standard reference for the optimum working condition …

Dry And Wet Torrefaction Of Microalgal Biomass For Biochar Production As Bioenergy Sources, Yong Yang Gan

Student Works (2020-2029)

Increasing population in global and living standards have risen the consumption of global energy. Thermochemical conversion approaches hold great potential for the biomass conversion into energy applications. Among these approaches, torrefaction is a promising technique to enhance the biomass properties, making it more practical and suitable in biofuel applications. In this study, two different species of microalgae (third generation biofuel feedstock) including Chlorella vulgaris ESP-31 and FSP-E were used as feedstocks for dry and wet torrefaction. Dry torrefaction of microalgae was performed at temperatures of 200, 250 and 300 ºC, and holding times of 15, 30, 45 and 60 min, …

Noble-Transition Alloy Absorbers For Near-Infrared Hot-Carrier Optoelectronics, Sara Karoline Figueiredo Stofela

LSU Doctoral Dissertations

Optoelectronics is the field of technology concerned with the study and application of electronic devices that source, detect and control light. Here we focus on the optical communications field which relies on optical fiber systems to carry signals to their destinations operating in the near-infrared range. To improve the performance of current optical fiber systems, one of the paths is to develop better near-infrared photodetectors.

The current group of materials used for near-infrared photodetection relies in the III-V semiconductor family. Although their spectral photosensitivity correlates well with the near-infrared, response time performance and electronic circuit integration remain limited for this …

Mechanical And Structural Behavior Of As-Built And Post Treated Ti6al4v Lattice Structures Fabricated By Selective Laser Melting (Slm), Hala Ahmed Salem

Theses and Dissertations

Lattice structure is a type of cellular structures that is composed of repeatable unit cells, each of which is formed of interconnect network of struts. Lattices with different structures are gaining attention for their good mechanical properties for light weight applications. Selective laser melting (SLM), is one of the AM powder-bed fusion fabrication techniques. SLM is widely known for its capability for fabricating complex metallic structures such as lattice structures with high resolution. SLM process influence the microstructure and mechanical properties of fabricated parts. The used processing parameters influence the level of internal porosity within the fabricated parts which directly …

Plasmonic-Active Nanostructured Thin Films, Jay Bhattarai, Helal Maruf, Keith Stine

Chemistry & Biochemistry Faculty Works

Plasmonic-active nanomaterials are of high interest to scientists because of their expanding applications in the field for medicine and energy. Chemical and biological sensors based on plasmonic nanomaterials are well-established and commercially available, but the role of plasmonic nanomaterials on photothermal therapeutics, solar cells, super-resolution imaging, organic synthesis, etc. is still emerging. The effectiveness of the plasmonic materials on these technologies depends on their stability and sensitivity. Preparing plasmonics-active nanostructured thin films (PANTFs) on a solid substrate improves their physical stability. More importantly, the surface plasmons of thin film and that of nanostructures can couple in PANTFs enhancing the sensitivity. …

A Validation Study For A New Erosion Model To Predict Erosive Airfoil Defouling, Arthur Rudek, David Muckenhaupt, Thomas Zitzmann, Gerald Russ, Barry Duignan

Articles

A new defouling erosion model for Lagrangian particle tracking is used to predict defouling of amor-phous, heterogeneous coatings such as those typically found in aircraft compressors. The main problem description, the mathematical formulation and the underpinning experiment of the model are presented in a previous communication by the authors. In this work, the Ansys CFX implementation of the model is described and an experiment is presented for the validation of the model. Air flows laden with a number of dry-ice particles are observed in an optically accessible stream channel containing a flat plate target. The defouling process of these particles …

Rc Mini Baja Car - Suspension And Chassis, Collin Mckenzie

All Undergraduate Projects

Two students have developed a unique design of the RC Baja Car to optimize functionality and performance. A Baja car is a remote controlled 1/10 scale car that is used for recreation or competition, usually meant for competing in the ASME Baja car competition versus various schools. The competition focuses on the best time achieved in different courses that utilize speed, turns, and jumps. The objective for the project was to create a unique suspension from previous individual’s projects by creating a four-link suspension in which allows more travel in the suspension of the car and maintains functionality with the …

Graphene/Oxide Interactions With Polymer Networks Modeled Using Molecular Dynamics, Matthew Alan Reil

Electronic Theses and Dissertations

Due to its unique physical properties, graphene has shown great promise as an additive to Polymer Matrix Composites (PMCs) for material property enhancement. Achieving homogeneous dispersion of the graphene platelets within a polymeric network is critical to realizing these enhancements. Research has shown that achieving homogeneous dispersion of graphene platelets within PMCs is challenging as graphene is immiscible with most polymeric networks. This work used Molecular Dynamics (MD) simulations to demonstrate dispersion of graphene platelets within PMCs is inhibited by molecular surface charge potentials. Further simulations were conducted to demonstrate functionalized forms of graphene, specifically graphene oxide, have altered surface …

Concrete Beam Design: Pouring The Foundation To Engineering In T&E Classrooms, Andrew J. Hughes, Chris Merrill

Educational Leadership & Technology Faculty Publications

Ask a middle or high school student if they could design a concrete beam that weighs only 20 pounds and is 36” long but must hold 600 pounds without failing. What is the student likely to say? What if the student was told that, with some optimized decision making based on relatively straightforward mathematics, their beam could hold 2400 pounds or more? The focus of this article is not on concrete beam design, it is rather an introduction to engineering principles in beam design using a lab activity. The concepts and skills learned in this article will lead students into …

Investigation Of Physiochemical Properties And Biocompatibility Of Amourphos Calcium Polyphosphate Hydrogel Doped With Antibiotics And Injectable Polymeric Dicalcium Phosphate Dihydrate Bone Cement, Yasaman Chehreghanianzabi

Wayne State University Dissertations

Amorphous calcium polyphosphate (ACPP) is an inorganic polymer ceramic. Here we use a simple method of preparing ACPP hydrogel in the presence of excess volume of water. Essentially, water availability to polyphosphate chains accelerates water molecule ingress and microstructural transformation of ACPP hydrogels. Antibiotic delivery capacity of ACPP hydrogel increases by the specific mixing and molding method, where the VCM has higher antibiotic encapsulation efficiency with the small burst release for the compressed discs. In part of this study, we investigate impact of ACPP hydrogel replacement by monomeric calcium phosphate on the quality of final product (dicalcium phosphate dihydrates (DCPD) …

Influence Of Graphene Oxide And Carbon Nanotubes On The Fatigue Properties Of Silica/Styrene-Butadiene Rubber Composites Under Uniaxial And Multiaxial Cyclic Loading, Zongchao Xu, Stephen Jerrams, Hao Guo, Yanfen Zhou, Liang Jiang, Yangyang Gao, Liqun Zhang, Li Liu, Shipeng Wen

Articles

The influence of equivalent replacement of silica (SiO2) by carbon nanotubes (CNT) or graphene oxide (GO) on the microstructure, mechanical and fatigue behaviors of SiO2/styrene-butadiene rubber (SBR) composites was investigated. Results showed that the synergistic effect between CNT (or GO) and SiO2 was beneficial for the filler network and improved the mechanical properties of SBR composites. Furthermore, the introduction of CNT (or GO) led to low crack growth rates and the crack propagation tips were easy to deflection. Under multiaxial fatigue conditions, the maximum engineering stress was determined to be a reliable fatigue life predictor for SBR composites.

Exact Solutions To The Three-Dimensional Navier-Stokes Equations Using The Extended Beltrami Method, Nolan J. Dyck, Anthony G. Straatman

Mechanical and Materials Engineering Publications

No abstract provided.

Nanoengineered Core-Shell Structures Using Tubile Halloysite Clay, Yusuf A. Darrat

Doctoral Dissertations

Halloysite nanotubes are a versatile nanomaterial that can be used in a wide variety of applications. They have a unique structure which could be described as a flat material that consists of silica on one side and alumina on the other; this structure is rolled up in a way naturally forming an internal 10-15 nm lumen and interlayer spacing. This could lead to many potential applications for example incorporating halloysite as a template material or as a support structure. They are an inexpensive clay material that is available in large quantities (thousands of tons), so they may be practically used …

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri

Wayne State University Dissertations

Solid electrolytes including ceramics and polymers are considered to be the ultimate substitute for organic liquid electrolytes currently used in commercialized lithium ion batteries to address the safety concerns due to Li dendrite growth and internal short circuiting. However, low ionic conductivity due to high grain boundary resistance in ceramics and semi-crystalline nature of polymers has held back the solid electrolytes from being used in Li-ion batteries. Polyethylene oxide (PEO), complexed with a Li-salt, is a well-studied polymer electrolyte showing ionic conductivity properties at room temperature. However, the coexistence of amorphous and crystalline regions at room temperature (< Tm, the melting temperature) has

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Development Of Lightweight Materials By Meso- And Microstructure Control, Myranda Shea Spratt

Doctoral Dissertations

”In this work, two lightweight structures – lattice structures and metal matrix syntactic foams (MMSF) – were studied. Honeycomb lattices were manufactured by powder bed selective laser melting (SLM) from 304L stainless steel. The wall thicknesses of these structures ranged from 0.2 to 0.5 mm. Surface roughness was the primary cause of dimensional mismatch between the expected and as-built structures with an average wall thickness increase of 0.12 mm. The strength of the honeycombs increased with increasing wall thickness. A feature of the SLM microstructure, the melt pool boundary, was also studied as a part of this work. 3D models …

Cerium Oxide Based Nanocomposites For Supercapacitors, Aadithya Jeyaranjan

Electronic Theses and Dissertations, 2020-2023

Access to clean, and sustainable energy is one of the biggest challenges of our generation. With the rapid growth of renewable energy harvesters, developing electrochemical energy storage devices (EEDs) that respond well to them is of significant interest. Supercapacitors are a class of EEDs with exceptional power densities and ultra-long cycle life. These properties make them an attractive candidate as a replacement, or to be used in combination with batteries and other EEDs. In this dissertation, nano cerium oxide (nano CeO2) based materials are examined as an active material for supercapacitor applications. The first part of this work details how …

Optimization Studies For The Gas Atomization And Selective Laser Melting Processes Of Al10simg Alloy, Sharon Park

Electronic Theses and Dissertations, 2020-2023

Selective laser melting (SLM) is an additive manufacturing technology that can fabricate complex engineering components using a scanning laser beam to melt consecutive layers of powders with characteristics that significantly influence material properties. Present work investigates both the gas atomization and SLM processes for the Al10SiMg alloy with a focus on establishing the relationships among atomization parameters, powder characteristics, SLM parameters and materials properties. Al10SiMg alloy powders (Al-10wt.%Si-0.5wt.%Mg) were batch-produced through gas atomization by systematically varying the melt flow rate (0.012 - 0.037 kg/s), gas pressure (1.4 - 3.1 MPa), and melt temperature (850C -1000C). The highest yield of 80 …

The Reliability Of Through Glass Vias And Solder Joints For Three Dimensional Multi Functional Integrated Systems, Omar Ahmed

Electronic Theses and Dissertations, 2020-2023

Three-dimensional (3D) integration technologies, including interposer-based integration, are among the most promising solutions to meet the increased demand for high performance computing, high chip density, and small form factor. Key technologies that enable 3D integration include through-substrate vias and solder joints. Glass is considered as a promising substrate material for interposer-based 3D integration technology especially in radio frequency applications because of glass's high resistivity, low dielectric constant, low electrical loss, and the adjustable coefficient of thermal expansion (CTE). However, during fabrication or service, through-glass vias can suffer from interface delamination and substrate cracking. The problem of copper protrusion is also …

Investigation Of Via Extrusion And The Effect Of Cap Layer For 3d Integrated Circuits, Golareh Jalilvand

Electronic Theses and Dissertations, 2020-2023

Copper (Cu) through-silicon via (TSV) is an essential structural and functional element in three-dimensional integration circuits (3D ICs), which offers substantial improvements in integration density, form factor, device performance, and power efficiency. However, Cu-filled TSVs are exposed to multiple thermal cycles during fabrication, test and operation, which lead to the development of considerable thermal stresses, in and around the vias, due to the large mismatch of the coefficient of thermal expansion (CTE) between Cu and silicon (Si). The stress subsequently raises reliability concerns, among which, via extrusion is an important one. Via extrusion can damage the adjacent components, in particular …

Characteristics Of Nanosilver Ink (Utdag) Microdroplets And Lines On Polyimide During Inkjet Printing At High Stage Velocity, Aamir Hamad, Adam Archacki, Ahsan Mian

Mechanical and Materials Engineering Faculty Publications

The performance of printed electronics strongly depends on printing techniques and printing resolution that enhance their electrical and mechanical properties. In this research paper, a Jetlab 4xl was used to control and dispense microdroplets of highly conductive nanosilver ink (UTDAg) on a polyimide substrate. The waveform effect on the droplet generation is characterized by measuring the size and the speed of the drops. The behavior of ejected drops on the substrate is studied by printing lines at different drop spacing and stage velocity. The jetting parameters that drive the piezoelectric actuator were properly determined and two waveforms (bipolar) were created …

A Numerical Simulation On The Airfoil S833 Equipped With Flapping Trailing Edge Fringes, H. Yu, Zifeng Yang

Mechanical and Materials Engineering Faculty Publications

Design optimization has been increasingly investigated for an airfoil, aiming to reduce the vorticity in the wake and increase the aerodynamic performance. In the current work, a two-dimensional (2D) S833 airfoil equipped with a flapping fringe at the trailing edge has been studied using computational fluid dynamics (CFD) simulations. The objective is to investigate the influence of the length (Lf) and flapping frequency (f) of the fringe on shedding vortices from the airfoil and the drag and lift coefficients. The validation of the current numerical approach for both static and dynamic motions of the airfoil was conducted. First, four different …

Evaluation Of Cyclo Olefin Polymer As Sabot Material For High-Density Projectiles, Estebanne Tarango

Open Access Theses & Dissertations

Assuring the integrity of spacecraft and its occupants are a priority in the field of space exploration. Micrometeoroids and orbital debris are one of the primary threats that affect spacecraft materials due to the high kinetic energies involved with hypervelocity impacts. Improvement of projectile launching capabilities prompts the investigation of adequate materials for the manufacturing of sabots able to carry high-density projectiles without catastrophic failure. Polycarbonate (PC) has been the chosen material by the Hypervelocity Team at White Sands Test Facility for sabots on the 0.50 caliber launcher; however, there is a material constraint when the projectile becomes significantly dense …

The Study Of Non-Permanent Tattoo Ink Using Nano Silver Compounds And Untact 3d Printing Technology, Jisu Lee

Open Access Theses & Dissertations

Due to a recent epidemic of COVID 19, the possibility of 3D tattoo printing technology using the Internet of Things (IoT) control system developed in a non-face-to-face contact process was identified. A non-surgical tattoo process and hygiene safety differentiated with silver tattoo ink was used to solve the health problems arising from the surgical tattoo process and to identify 3D tattoo printing techniques through a non-personal contact concept. During the tattoo processing, the image selected by the customer is sent to a designated printer via an IoT control system in a separate location. A piston-type extruder (PTE) printing technique was …

Enhancement Of Absorptance By Ultrafast Laser Pulse Shaping For Efficient Laser Processing Of Thin Polymers, Arifur Rahaman

Electronic Theses and Dissertations, 2020-2023

Ultrashort-pulsed lasers have been used for high precision processing of a wide range of materials including dielectrics, semiconductors, metals, and polymers/polymer composites, enabling numerous applications ranging from micromachining, photonics to life sciences. However, there are challenges when applying this technology in the industry, which requires scale and throughput different from lab use. The goal of this research is to understand how ultrafast laser pulses interact with thin polymers/polymer composite materials and develop a method that is efficient for ultrafast laser processing of these materials. It is a common practice in industrial applications to run the laser at a high repetition …

Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes

Electronic Theses and Dissertations

GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. The first of its kind, GRCop-84, was specifically designed for the environments seen by channel cooled main combustion chamber liners. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop- 42 was developed. In recent years, NASA has successfully additively manufactured GRCop with comparable material characteristics to wrought GRCop using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate cooling channels as …

Data-Driven Modeling Of The Wake Behind A Wind Turbine Array, Naseem Ali, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

The wake flow in a wind turbine array boundary layer is described using the Koopman operator. Dynamics of the flow are decomposed into the linear and forcing terms, and the low-energy delay coordinates are revealed. The rare events show the non-Gaussian long tails that capture the switching and bursting phenomena. The near-wake region shows the incoherent phase space region, where the dynamics are strongly nonlinear. The far-wake region is marked with the small non-Gaussian forcing term, and the dynamics are largely governed by linear dynamics. The data-driven predictive model is built based on the Hankel-based dynamic mode decomposition and treats …

Utility-Scale Solar Pv Performance Enhancements Through System-Level Modifications, Andrew D. S. Glick, Naseem Ali, Juliaan Bossuyt, Marc Calaf, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Performance of solar PV diminishes with the increase in temperature of the solar modules. Therefore, to further facilitate the reduction in cost of photovoltaic energy, new approaches to limit module temperature increase in natural ambient conditions should be explored. Thus far only approaches based at the individual panel level have been investigated, while the more complex, systems approach remains unexplored. Here, we perform the first wind tunnel scaled solar farm experiments to investigate the potential for temperature reduction through system-level flow enhancement. The percentage of solar irradiance converted into electric power depends upon module efficiency, typically less than 20%. The …