Engineering Commons^™

Conductivity Modulation In Strained 2d Transition- Metal- Dichalcogenides Via Micro- Electro- Mechanical Actuation, Aldo Ivan Vidaña

Open Access Theses & Dissertations

In this thesis, strain-induced conductivity modulation in bi-layer molybdenum disulfide (MoS2) flakes is experimentally investigated and modeled. Uniaxial tensile strain in the MoS2 flakes is achieved using a micro-electro-mechanical (MEM) actuator. Conductivity ratios up to 400 are demonstrated. Theoretical predictions of conductivity versus applied voltage in the MEMS-MoS2 device match experimental data reasonably well using only the effective width of the TMDC flakes as the sole fitting parameter. The amount of strain induced in the MoS2 flakes was determined to be as high as 2.7% for one flake using the model fitted to the experiment data. The switching energy required …

Thermo-Fluid System Level Modeling For The Crome And Crome-X Ground Propellant System Using Generalized Fluid System Simulation Program, Mariano Mercado

Open Access Theses & Dissertations

A recent resurgence of interest in space exploration has given rise to a number of newcomers in the space industry. A number of private companies like SpaceX, Blue Origin, and United Launch Alliance have joined the likes of NASA with the goal to expand the current capabilities of space travel and exploration. Perhaps the most ambitious of these goals is a manned mission to Mars. In order to achieve this goal, many of these companies have taken a keen interest in liquid oxygen and methane engine technologies. Engines like the Raptor by SpaceX and the Blue Origin BE-4 already run …

Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco

Open Access Theses & Dissertations

Nitride nanocomposite thin films have generated significant attention as a result of their robust mechanical properties, excellent triobology, and good chemical (corrosion) stability. Due to their excellent hardness and high wear resistance NbN coatings have found use in a wide variety of applications such as the coating of cutting tools and to strengthen the surface mechanical properties of superconducting cavities. The mechanical properties of NbN can be further improved through mixing with Si3N4, leading to the formation of a nanocomposite structure. NbN-Si3N4 nanocomposite coatings have been actively studied due to their high hardness, high elastic modulus, and high resistance to …

Development And Implementation Of The Triac Data Acquisition And Control System, Raymundo Mendivil Rojo

Open Access Theses & Dissertations

The Technology Research and Innovation Acceleration Park (tRIAC) located at Fabens, Texas, was established for the ongoing development and testing of the miro center for Space Exploration and Technology Research’s (cSETR’s) liquid methane and liquid oxygen rocket engines. These engines range from a 5 lbf Reaction Control Engine (RCE) to the 500 lbf and 2000 lbf Centennial Restartable Oxygen Methane Engines, called CROME and CROME-X respectively. Alongside their development, a comprehensive control system was built in the Modular Instrumentation and Control Interface Trailer (MICIT) and is equipped with National Instrument’s LabVIEW software and hardware. The LabVIEW code is based off …

Dedicated Hardware For Machine/Deep Learning: Domain Specific Architectures, Angel Izael Solis

Open Access Theses & Dissertations

Artificial intelligence has come a very long way from being a mere spectacle on the silver screen in the 1920s [Hml18]. As artificial intelligence continues to evolve, and we begin to develop more sophisticated Artificial Neural Networks, the need for specialized and more efficient machines (less computational strain while maintaining the same performance results) becomes increasingly evident. Though these “new” techniques, such as Multilayer Perceptron’s, Convolutional Neural Networks and Recurrent Neural Networks, may seem as if they are on the cutting edge of technology, many of these ideas are over 60 years old! However, many of these earlier models, at …

Performance Evaluation Of Communication Technologies And Network Structure For Smart Grid Applications, Desong Bian, Murat Kuzlu, Manisa Pipattanasomporn, Saifur Rahman, Di Shi

Engineering Technology Faculty Publications

The design of an effective and reliable communication network supporting smart grid applications requires the selection of appropriate communication technologies and protocols. The objective of this study is to study and quantify the capabilities of an advanced metring infrastructure (AMI) to support the simultaneous operation of major smart grid functions. These include smart metring, price-induced controls, distribution automation, demand response, and electric vehicle charging/discharging applications in terms of throughput and latency. OPNET is used to simulate the performance of selected communication technologies and protocols. Research findings indicate that smart grid applications can operate simultaneously by piggybacking on an existing AMI …

Exposing Students To Stem Careers Through Hands-On Activities With Drones And Robots, Vukica M. Jovanović, George Mcleod, Thomas E. Alberts, Cynthia Tomovic, Otilia Popescu, Tysha Batts, Ms. Mary Louise Sandy

Engineering Technology Faculty Publications

Autonomous robots have been used in a variety of ways from collecting specimen in hazardous environments to space exploration. These robots can be found in various manufacturing systems as Autonomous Guided Vehicles (AGVs) to transport parts and assemblies throughout the manufacturing system. They have also been used as a vehicle to convey design thinking and other STEM-related concepts in mechanical engineering/mechanical engineering technology, electrical engineering/electrical engineering technology, computer science, and computer engineering. Various outreach events have included robotics based activities that engage students in building and programming autonomous robots for the purpose of achieving a specific task. These events are …

Spin Response Function For Spin Transparency Mode Of Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang

Engineering Technology Faculty Publications

In the Spin Transparency (ST) mode of RHIC, the axes of its Siberian snakes are parallel. The spin tune in the ST mode is zero and the spin motion becomes degenerate: any spin direction repeats every particle turn. In contrast, the lattice of a conventional collider determines a unique stable periodic spin direction, so that the collider operates in the Preferred Spin (PS) mode. Contributions of perturbing magnetic fields to the spin resonance strengths in the PS mode are usually calculated using the spin response function. However, in that form, it is not applicable in the ST mode. This paper …

Uv-Curable Organic-Inorganic Hybrid Polyurethane Coating, Shiyin Yu

Master's Theses and Doctoral Dissertations

This thesis explored a series of organic-inorganic hybrid polyurethane oligomers with varying molecular weights and functional groups (acrylate and/or silane) that were cured with a single ultraviolet (UV) trigger but two photo-initiators. Upon UV irradiation, the free-radical initiator initiated a free-radical reaction for acrylate cross-linking, and the photo-latent base initiated a sol-gel reaction for condensation of the silanes. This study explored the cure extent of both reactions by FTIR for acrylates and silanes and a weight-loss method for silanes as a function of functional group concentration and time. The general film properties were also studied. The results showed that the …

Glioma Grading Using Structural Magnetic Resonance Imaging And Molecular Data, Syed M.S. Reza, Manar D. Samad, Zeina A. Shboul, Karra A. Jones, Khan M. Iftekharuddin

Electrical & Computer Engineering Faculty Publications

A glioma grading method using conventional structural magnetic resonance image (MRI) and molecular data from patients is proposed. The noninvasive grading of glioma tumors is obtained using multiple radiomic texture features including dynamic texture analysis, multifractal detrended fluctuation analysis, and multiresolution fractal Brownian motion in structural MRI. The proposed method is evaluated using two multicenter MRI datasets: (1) the brain tumor segmentation (BRATS-2017) challenge for high-grade versus low-grade (LG) and (2) the cancer imaging archive (TCIA) repository for glioblastoma (GBM) versus LG glioma grading. The grading performance using MRI is compared with that of digital pathology (DP) images in the …

Effect Of Model Of Care And Comorbidities On Multiple-Drug-Resistant Tuberculosis Treatment In Nigeria, Oluremilekun Comfort Kusimo

Walden Dissertations and Doctoral Studies

Multidrug-resistant tuberculosis (MDR-TB) is a public health problem in several countries such as Angola, India, China, Kenya, and Nigeria. Due to the increasing high burden of MDR-TB, most of these countries do not have adequate capacities to manage MDR-TB patients effectively. This study investigated the effect of model of care; human immunodeficiency virus comorbidity; and demographic factors such as age, gender, and marital status on the treatment outcomes of MDR-TB patients in Nigeria. The study was based on the analysis of secondary data of 402 MDR-TB patients accessed from the data systems of the National Tuberculosis, Buruli Ulcer, and Leprosy …

Special Issue On Low Temperature Plasma Jets, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

[Introduction] Low temperature plasma jets are unique plasma sources capable of delivering plasma outside of the confinement of electrodes and away from gas enclosures/chambers. With these jets plasma can be easily delivered to a target located at some distance from the plasma generation region [1].

Near-Field Electrospinning Of A Polymer/Bioactive Glass Composite To Fabricate 3d Biomimetic Structures, Krishna C. R. Kolan, Jie Li, Sonya Roberts, Julie A. Semon, Jonghyun Park, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Bioactive glasses have recently gained attention in tissue engineering and three-dimensional (3D) bioprinting because of their ability to enhance angiogenesis. Some challenges for developing biological tissues with bioactive glasses include incorporation of glass particles and achieving a 3D architecture mimicking natural tissues. In this study, we investigate the fabrication of scaffolds with a polymer/bioactive glass composite using near-field electrospinning (NFES). An overall controlled 3D scaffold with pores, containing random fibers, is created and aimed to provide superior cell proliferation. Highly angiogenic borate bioactive glass (13-93B3) in 20 wt.% is added to polycaprolactone (PCL) to fabricate scaffolds using the NFES technique. …

Modeling Cell Line-Specific Recruitment Of Signaling Proteins To The Insulin-Like Growth Factor 1 Receptor, Keesha E. Erickson, Dipak Barua, For Full List Of Authors, See Publisher's Website.

Chemical and Biochemical Engineering Faculty Research & Creative Works

Receptor tyrosine kinases (RTKs) typically contain multiple autophosphorylation sites in their cytoplasmic domains. Once activated, these autophosphorylation sites can recruit downstream signaling proteins containing Src homology 2 (SH2) and phosphotyrosine-binding (PTB) domains, which recognize phosphotyrosine-containing short linear motifs (SLiMs). These domains and SLiMs have polyspecific or promiscuous binding activities. Thus, multiple signaling proteins may compete for binding to a common SLiM and vice versa. To investigate the effects of competition on RTK signaling, we used a rule-based modeling approach to develop and analyze models for ligand-induced recruitment of SH2/PTB domain-containing proteins to autophosphorylation sites in the insulin-like growth factor 1 …

Effects Of Mixing Methods Of Bifunctional Catalysts On Catalyst Stability Of Dme Synthesis Via Co₂ Hydrogenation, Shoujie Ren, Shiguang Li, Naomi Klinghoffer, Miao Yu, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of three different mixing methods of CuO/ZnO/Al₂O₃ (CZA) and HZSM-5 bifunctional catalyst on the stability for dimethyl ether (DME) synthesis from carbon dioxide (CO₂) hydrogenation were investigated. When the bifunctional catalyst was prepared by method A (mixing powder without pelletization), there was no significant change in DME production and catalyst stability when the HZSM-5 loading was varied between 0.1 g and 0.5 g with a fixed CZA loading of 0.5 g,. When the bifunctional catalysts were prepared by method B (pressed into pellets of CZA and pellets of HZSM-5 and then mixed) and …

In Situ Mechanical Characterization Of The Mixed- Mode Fracture Strength Of The Cu/Si Interface For Tsv Structures, Chenglin Wu, Congjie Wei, Yanxiao Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In situ nanoindentation experiments have been widely adopted to characterize material behaviors of microelectronic devices. This work introduces the latest developments of nanoindentation experiments in the characterization of nonlinear material properties of 3D integrated microelectronic devices using the through-silicon via (TSV) technique. The elastic, plastic, and interfacial fracture behavior of the copper via and matrix via interface were characterized using small-scale specimens prepared with a focused ion beam (FIB) and nanoindentation experiments. A brittle interfacial fracture was found at the Cu/Si interface under mixed-mode loading with a phase angle ranging from 16.7° to 83.7°. The mixed-mode fracture strengths were extracted …

Smart Building And Construction Materials, Donglu Shi, Julian Wang, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Advances and innovations in materials science and engineering have always played a substantial role in civil engineering, building structural design, and construction. In recent years, extensive effort has been devoted to the applications of stimuli-responsive smart materials and nanostructures in buildings. These smart materials used in the built environment can be defined as those offering specific functional and adaptable properties in response to thermal, optical, structural, and environmental stimuli. Not only do these materials enhance the overall performance of new building construction but also promise safer structures, longer durability of building elements, efficient building energy savings, greater environmental sustainability, and …

Recent Results From Nb₃Sn Single Cell Cavities Coated At Jefferson Lab, U. Pudasaini, M. J. Kelley, Gianluigi Ciovati, G.V. Eremeev, M. J. Kelley, C. E. Reece, Ishwari Prasad Parajuli, Md. Nizam Sayeed

Physics Faculty Publications

Because of superior superconducting properties (Tc ~ 18.3K, H_{s h}~ 425 mT and Δ ~ 3.1 meV) compared to niobium, Nb₃Sn promise better RF performance (Q₀ and E_acc) and/or higher operating temperature (2 K Vs 4.2 K) for SRF cavities. Nb₃Sn-coated SRF cavities are produced routinely by depositing a few micron-thick Nb₃Sn films on the interior surface of Nb cavities via tin vapor diffusion technique. Early results from Nb₃Sn cavities coated with this technique exhibited precipitous low field Q-slope, also known as Wuppertal slope. Several Nb₃Sn single cell cavities coated at JLab appeared to exhibit …

Solutions For Fermi Questions, November 2019: Question 1: Cell Phones Make Me Boil; Question 2: Charging The Phone, Larry Weinstein

Physics Faculty Publications

Answers to the Fermi questions:

How much water can you boil with the energy stored in a cell phone battery?

How much does the electrical energy for a cell phone cost each year?

Melt Property Variation In Gese2-As2se3-Pbse Glass Ceramics For Infrared Gradient Refractive Index (Grin) Applications, Anupama Yadav, Andrew Buff, Myungkoo Kang, Laura Sisken, Charmayne Smith (Lonergan), Jason Lonergan, Cesar Blanco, Michael Antia, Megan Driggers, Andrew Kirk, Clara Rivero-Baleine, Theresa Mayer, Andrew Swisher, Alexej Pogrebnyakov, A. R. Hilton, Greg Whaley

Materials Science and Engineering Faculty Research & Creative Works

Melt size-dependent physical property variation is examined in a multicomponent GeSe₂-As₂Se₃-PbSe chalcogenide glass developed for gradient refractive index applications. The impact of melting conditions on small (40 g) prototype laboratory-scale melts extended to commercially relevant melt sizes (1.325 kg) have been studied and the role of thermal history variation on physical and optical property evolution in parent glass, the glass' crystallization behavior and post heat-treated glass ceramics, is quantified. As-melted glass morphology, optical homogeneity and heat treatment-induced microstructure following a fixed, two-step nucleation and growth protocol exhibit marked variation with melt size. These attributes …

The Influence Of Of Company Culture On Employee Satisfaction At Holder Construction: A Case Study, Callie Alexander

Construction Management

Since being founded in 1960, Holder Construction has grown to do work all across The United States and internationally as well. Today, repeat clients are what drive Holder’s core markets and provide eighty five percent of the work that Holder performs. The associates at Holder Construction believe their success stems from the company’s culture. The “Holder Way” is a slogan that encompasses all cultural attributes that Holder Construction expects their associates to embody. This case study evaluates Holder Construction’s effectiveness of their company’s cultural training in regards to employee satisfaction and fulfillment. Are these employees truly living out what is …

Osha-30 Interactive Laboratory Course, Matthew Bramlett

Construction Management

This course is aimed to give the students of the Construction Management (CM) department a more in depth knowledge on topics covered in the online OSHA-30 hour safety course. The online focuses on a wider range of topics that are covered in the OSHA-10 hour course that students are required to complete in CM 413: Jobsite Management, such as hazard communication, OSHA inspection procedures, industrial hygiene & bloodborne pathogens, and much more. The course will also include topics outside the scope of the 30-hour class such as: heavy equipment inspections, rigging safety and techniques, challenges of working in the marine …

Implementation Of Blockchain Technology In The Construction Industry, Steven Graham

Construction Management

In general, the construction industry has been pretty resistant to change. While most industries have gained in productivity over the years through implementation of new technologies and other factors, construction industry productivity has been on a steady decline since the 1960s. Even though there are a multitude of reasons for this, including more complex building types and a decline in the workforce, the major problem holding construction back are project management issues and alienation of project stakeholders in the construction process. Some improvements have been made to help with collaboration between parties, like BIM (building information modeling) and project management …

Logistics And Funding Plan For The Simpson Strong-Tie Lab Crane, Arya Ghourchian

Construction Management

In the recent years, there has been interests regarding an overhead crane to be erected inside of Cal Poly Simpson Strong Tie Lab (Building 187). This under running single girder crane system will be used for construction classes, and to lift heavy equipment. The erection of this 2 Ton indoor crane will be crucial to provide modular pieces, for whom that lost their homes due to the California fires. Additionally, there has been previous senior projects researches; reference attached preconstruction services, and a full structural analysis of SST Laboratory. I am in charge of collecting information regarding: Bid Estimate, Advertisement …

Reducing Energy Use In Excavators With Biodiesel, Omeed Abolfathi

Construction Management

In assessing the life-cycle cost of a building, the operation energy and construction energy are considered. The operation energy constitutes 90 to 95 percent of the lifetime energy use of a building. Concern over reducing operation energy has led to advancements where many buildings can now be considered net zero. While considerable advancements were made in achieving net zero in the operation, construction energy use has largely remained the same. To achieve net zero for the entire life-cycle of the building, construction energy consumption needs to be reduced. Excavators are one of the most popular pieces of construction equipment. They …

Instance Segmentation And Object Detection In Road Scenes Using Inverse Perspective Mapping Of 3d Point Clouds And 2d Images, Chungyup Lee

Electronic Theses and Dissertations

The instance segmentation and object detection are important tasks in smart car applications. Recently, a variety of neural network-based approaches have been proposed. One of the challenges is that there are various scales of objects in a scene, and it requires the neural network to have a large receptive field to deal with the scale variations. In other words, the neural network must have deep architectures which slow down computation. In smart car applications, the accuracy of detection and segmentation of vehicle and pedestrian is hugely critical. Besides, 2D images do not have distance information but enough visual appearance. On …

Column Flotation Performance Prediction: Pca, Ann And Image Analysis-Based Approaches, Fardis Nakhaei, Mehdi Irannajad, Sima Mohammadnejad

Mining Engineering Faculty Research & Creative Works

The flotation froth surface appearance includes remarkable information, which can be employed as a helpful index for the qualitative evaluation of the process efficiency. Image analysis is a practical technology for the sake of achieving process related information that can be employed in expert controllers in order to amend flotation performance. In this paper, the intelligent modelling of relationship between froth characteristics and the metallurgical performance in a pilot column flotation of iron ore was established. Column flotation tests were carried out at a wide range of operating conditions and the froth features along with the metallurgical performances were specified …

A Seed Dormancy Gene-Mediated Biotechnology To Mitigate Transgene Flow Into Weedy Rice, Luai Nahar Muhammad

Electronic Theses and Dissertations

Transgene flows into wild/weedy relatives may cause ecological and economic problems. Seed dormancy is an adaptive trait that distributes germination over time and promotes persistence of weeds in agroecosystems. Silencing natural genes controlling seed dormancy (SD) could promote germination and reduce weed adaptability. The goal of this project was to develop a transgenic mitigation (TM) technology by linking to a primary transgene with an SD gene-silencing structure, as a tandem construct for transformation, to reduce the risk of gene flow into weed populations. In this research, the Bar (Bialaphos) gene for resistance to the glufosinate herbicide was used as a …

Impulse Measurements Of Electric Solid Propellant In An Electrothermal Ablation-Fed Pulsed Plasma Thruster, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled and extinguished) through the application and removal of an electric current. These propellants are also being considered for use in the ablative pulsed plasma thruster. In this paper, the performance of an electric solid propellant operating in an electrothermal ablation-fed pulsed plasma thruster was investigated using an inverted pendulum micro-Newton thrust stand. The impulse bit and specific impulse of the device using the electric solid propellant were measured for short-duration test runs of 100 pulses and longer-duration runs to end-of-life, at energy levels of 5, …

Thermodynamic And Transport Properties Of Hydroxylammonium Nitrate-Based Electric Solid Propellant Vapor, Matthew S. Glascock, Patrick D. Drew, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants controlled by electric current. Electric solid propellants may also be used in an electric propulsion system, specifically, an ablative pulsed plasma thruster. Previous experiments with the electric solid propellant HIPEP suggest its ablation processes are similar to traditional propellant polytetrafluoroethylene (C2F4). Better understanding of the ablation and resulting propulsion performance of HIPEP requires a model of its vapor composition and transport properties. This paper reports on the development of such a model. The model was validated by comparing results for C2F4 with literature, which showed agreement with multiple models described. Transport …