Engineering Commons^™

Mechanical Properties Of 3d Printed Acrylonitrile Styrene Acrylate, William Cahyadi

Electronic Theses and Dissertations

Several studies have been conducted on FDM 3d printed materials such as PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene), however, not for ASA (Acrylonitrile Styrene Acrylate). The use of ASA has been increasing due to its resistance to UV, heat, and some chemicals. The resistance to UV prevents the material from degrading its material properties in common outdoor conditions, whereas resistance to heat and oil prevents the material from discoloration. This combination of effects allows designers to use ASA in outdoor applications, however, material properties for ASA in the FDM 3d printing manufacturing process are not well defined. It …

Repairable Moment-Resisting Steel Buildings, Heath William Pederson

Electronic Theses and Dissertations

Current seismic design codes ensure life safety for buildings, but structural members may significantly yield or even fail under strong earthquakes. A new design approach is to implement connections that localize the yielding and failure to fuses. A more sophisticated approach is to be able to replace the fuses after the event. The present study was carried out to develop repairable moment-resisting (MR) connections for steel buildings and to investigate their seismic performance through nonlinear finite element analyses (FEA). Two details were proposed using buckling restrained fuses (BRFs) and buckling restrained reinforcement (BRR). Test data was collected from the literature …

Well-Ordered Mesoporous Silica And Bioactive Glasses: Promise For Improved Hemostasis, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediate control of uncontrolled bleeding and infection are essential for saving lives in both combat and civilian arenas. Inorganic well-ordered mesoporous silica and bioactive glasses have recently shown great promise for accelerating hemostasis and infection control. However, to date, there has been no comprehensive report assessing their specific mechanism of action in accelerating the hemostasis process and exerting an antibacterial effect. After providing a brief overview of the hemostasis process, this review presents a critical overview of the recently developed inorganic mesoporous silica and bioactive glass-based materials proposed for hemostatic clinical applications and specifically investigates their unique characteristics that render …

Synthesis, Characterization And Selected Application Of Chitosan-Coated Magnetic Iron Oxide Nanoparticles, M. A. Radwan, Mohamed Adel Rashad, M. A. Sadek, Hany A. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, we report an efficient method to prepare highly active chitosan-coated magnetic iron oxide nanoparticles by implementing co-precipitation technique which is used for wastewater treatment applications. Chitosan-coated magnetic iron oxide nanoparticles were synthesized and characterized using TEM, XRD, and XPS. A comparative study has been made between chitosan powder and chitosan coated with magnetic nanoparticles with respect to the rate of adsorption of copper from aqueous solution. It was also experimentally verified that chitosan coated magnetic iron oxide nanoparticles are much more effective in adsorption of heavy metals than chitosan powder and it takes just few minutes instead …

Slightly Fluorination Of Al2o3 Ald Coating On Li1.2mn0.54co0.13ni0.13o2 Electrodes: Interface Reaction To Create Stable Solid Permeable Interphase Layer, Han Yu, Yan Gao, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Improving the performance of cathodes by using surface coatings has proven to be an effective method for improving the stability of Li-ion batteries (LIBs), while a high-quality film satisfying all requirements of electrochemical inertia, chemical stability, and lithium-ion conductivity has not been found. In this study, a composite film composed of Al₂O₃ and AlF₃ layers was coated on the surface of Li_1.2Mn_0.54Co_0.13Ni_0.13O₂ (Li-rich NMC) based electrodes by atomic layer deposition (ALD). By varying the ratio of Al₂O₃ and AlF₃, an optimal coating …

Magnetic Composite Biomaterials For Neural Regeneration, Jessica L. Funnell, Bailey Balouch, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Nervous system damage caused by physical trauma or degenerative diseases can result in loss of sensory and motor function for patients. Biomaterial interventions have shown promise in animal studies, providing contact guidance for extending neurites or sustained release of various drugs and growth factors; however, these approaches often target only one aspect of the regeneration process. More recent studies investigate hybrid approaches, creating complex materials that can reduce inflammation or provide neuroprotection in addition to stimulating growth and regeneration. Magnetic materials have shown promise in this field, as they can be manipulated non-invasively, are easily functionalized, and can be used …

Real-Time Electrical Impedance Monitoring Of Carbon Fiber-Reinforced Polymer Laminates Undergoing Quasi-Static Indentation, Khaled Almuhammadi, Arief Yudhanto, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated composites are vulnerable to damage from out-of-plane loading, particularly impact loading, and the incurred damage is often only detected by evaluating the post-impact condition of the composites. Real-time monitoring techniques are desirable for early detection of damage. Utilizing changes in the electrical properties of composites to track incurred damage is promising, but the interpretation of such measurements is still challenging. Here, an electro-mechanical system is introduced to understand how well we could detect mechanical degradation in carbon-fiber-reinforced polymer (CFRP) plates undergoing a quasi-static indentation (QSI) test, which is representative of an impact load. The system measures the in situ, …

An Experimental Approach That Assesses In-Situ Micro-Scale Damage Mechanisms And Fracture Toughness In Thermoplastic Laminates Under Out-Of-Plane Loading, H. Wafai, A. Yudhanto, G. Lubineau, R. Yaldiz, N. Verghese

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Studying the response of laminated composites under out-of-plane loading routinely involves mechanical tests, such as quasi-static indentation or impact. The phenomenology during these tests is so complex that it is difficult to identify different material properties related to each failure mechanism (damage mode). We aim at providing an experimental approach, which is practical and fast, for assessing the in-situ micro-scale damage mechanism and extracting the fracture toughness in thermoplastic laminates under out-of-plane loading. To this end, we developed a dedicated, micro-scale, three-point bending (micro-3PB) test fitted inside a scanning electron microscope (SEM). In a single experiment, we were able: (i) …

Determine Airborne Release Fractions (Arf) / Respirable Fractions (Rf) For Use In Safety Based Documents, Michael Quinn, Jacob Miller

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Experimental Investigation Of The Dynamics Of Trapped Non-Wetting Droplets Subjected To The Seismic Stimulation In Constricted Tubes: Supporting Information, Yandong Zhang, Chao Zeng, Baojun Bai, Wen Deng

Research Data

• Aspect Ratio of 4.5
• Aspect Ratio of 9.0
• Video Demos

Walking Biomechanics And Energetics Of Individuals With A Visual Impairment: A Preliminary Report, Hunter J. Bennett, Kevin A. Valenzuela, Kristina Fleenor, Steven Morrison, Justin A. Haegele

Human Movement Studies & Special Education Faculty Publications

Purpose.

Although walking gait in sighted populations is well researched, few studies have investigated persons with visual impairments (VIs). Given the lack of physical activity in people with VIs, it is possible that reduced efficiency in walking could adversely affect activity. The purposes of this preliminary study were to (1) examine the biomechanics and energetics utilized during independent and guided walking in subjects with VIs, and (2) compare gait biomechanics between people with VIs and sighted controls.

Methods.

Three-dimensional motion capture and force platforms were used during independent and guided walking at self-selected speeds. Joint angles, moments, external work, and …

A Critical Review Of Using High Viscosity Friction Reducers As Fracturing Fluids For Hydraulic Fracturing Applications, Mohammed Ba Geri, Abdulmohsin Imqam, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The primary purpose of using traditional friction reducers in stimulation treatments is to overcome the tubular drag while pumping at high flow rates. Hydraulic fracturing is the main technology used to produce hydrocarbon from extremely low permeability rock. Even though slickwater (water fracturing with few chemical additives) used to be one of the most common fracturing fluids, several concerns are still associated with its use, including usage of freshwater, high-cost operation, and environmental issues. Therefore, current practice in hydraulic fracturing is to use alternative fluid systems that are cost effective and have less environmental impact, such as fluids which utilize …

Investigate The Rheological Behavior Of High Viscosity Friction Reducer Fracture Fluid And Its Impact On Proppant Static Settling Velocity, Mohammed Ba Geri, Abdulmohsin Imqam, Andrey Bogdan, Lingjuan Shen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recent and rapid success of using high viscosity friction reducers (HVFRs) in hydraulic fracturing treatments is due to several advantages over other fracture fluids (e.g. linear gel), which include better proppant carrying capability, induce more complex fracture system network with higher fracture length, and overall lower costs due to fewer chemicals and less equipment on location. However, some concerns remain, like how HVFRs rheological properties can have impact on proppant transport into fractures. The objective of this study is to provide a comprehensive understanding of the influence the rheological characterization of HVFRs have on proppant static settling velocity within …

Atomistic Simulations Of Nanoindentation Response Of Irradiation Defects In Iron, M. Mustafa Azeem, Qingyu Wang, Muhammad Zubair

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Radiation response of a material is a consequence of defects' evolution in any radiation damage event. The radiation-induced defects can significantly alter the mechanical properties of a material. Radiation damage initiates from incident neutron by bombardment on solid material causing production and evolution of Frenkel defects. Since voids are formed due to aggregation of a large number of vacancies that cause dimensional changes and hence irradiation-induced swelling. In order to characterize the effect of irradiation defects, we have performed molecular dynamics (MD) simulations to investigate nanoindentation response of point defects and voids in Fe and their effects on mechanical parameters. …

Should Robots Prosecute And Defend?, Stephen E. Henderson

Faculty Articles

Even when we achieve the ‘holy grail’ of artificial intelligence—machine intelligence that is at least as smart as a human being in every area of thought—there may be classes of decisions for which it is intrinsically important to retain a human in the loop. On the common account of American criminal adjudication, the role of prosecutor seems to include such decisions given the largely unreviewable declination authority, whereas the role of defense counsel would seem fully susceptible of automation. And even for the prosecutor, the benefits of automation might outweigh the intrinsic decision-making loss, given that the ultimate decision—by judge …

Performance Analysis Of Machine Learning And Deep Learning Architectures For Malaria Detection On Cell Images, Barath Narayanan, Redha Ali, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

Plasmodium malaria is a parasitic protozoan that causes malaria in humans. Computer aided detection of Plasmodium is a research area attracting great interest. In this paper, we study the performance of various machine learning and deep learning approaches for the detection of Plasmodium on cell images from digital microscopy. We make use of a publicly available dataset composed of 27,558 cell images with equal instances of parasitized (contains Plasmodium) and uninfected (no Plasmodium) cells. We randomly split the dataset into groups of 80% and 20% for training and testing purposes, respectively. We apply color constancy and spatially resample all images …

Active Recall Networks For Multiperspectivity Learning Through Shared Latent Space Optimization, Theus Aspiras, Ruixu Liu, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

Given that there are numerous amounts of unlabeled data available for usage in training neural networks, it is desirable to implement a neural network architecture and training paradigm to maximize the ability of the latent space representation. Through multiple perspectives of the latent space using adversarial learning and autoencoding, data requirements can be reduced, which improves learning ability across domains. The entire goal of the proposed work is not to train exhaustively, but to train with multiperspectivity. We propose a new neural network architecture called Active Recall Network (ARN) for learning with less labels by optimizing the latent space. This …

Voltage And Deflection Amplification Via Double Resonance Excitation In A Cantilever Microstructure, Mohammad H. Hasan, Fadi Alsaleem, Abdallah Ramini

Durham School of Architectural Engineering and Construction: Faculty Publications

Cantilever electrostatically-actuated resonators show great promise in sensing and actuating applications. However, the electrostatic actuation suffers from high-voltage actuation requirements and high noise low-amplitude signal-outputs which limit its applications. Here, we introduce a mixed-frequency signal for a cantilever-based resonator that triggers its mechanical and electrical resonances simultaneously, to overcome these limitations. A single linear RLC circuit cannot completely capture the response of the resonator under double resonance excitation. Therefore, we develop a coupled mechanical and electrical mathematical linearized model at different operation frequencies and validate this model experimentally. The double-resonance excitation results in a 21 times amplification of the voltage …

Benchmarking Image Processing Algorithms For Unmanned Aerial System-Assisted Crack Detection In Concrete Structures, Sattar Dorafshan, Robert J. Thomas, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare dierent edge detectors. Edge detection was carried out by six …

Remotely Testing Whether A Climate Control System Controller Is Correctly Installed, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

Disclosed are exemplary embodiments of apparatus and methods for remote testing of controllers such as thermostats, to detect incorrect climate control system configuration parameters . In an exemplary embodiment, a computer wirelessly connects with a remote thermostat and sends signal (s) to the thermostat instructing the thermostat to perform climate control function (s) in predefined sequence (s). The computer receives signal (s) from the thermostat indicating whether the thermostat is performing the climate control function (s) in accordance with the sent signal (s). Based on the signal (s) received from the thermostat, the computer determines whether the thermostat is configured …

Cadmium Sulfide-Buffered Pv Systems: Assessing The Environmental, Health, And Economic Impacts, Maqsood Ali Mughal, Rajesh Sharma

Journal of the Arkansas Academy of Science

As the world’s population continues to grow, global energy crises are expected to rise in the future, thus accelerating the demand for renewable energy technology, particularly solar photovoltaics. The energy sector will face an increasingly complex array of interlocking challenges - technological, environmental, health, economic, and regulatory. In this paper, we study CdS, a widely used buffer material in thin film photovoltaics, to assess and monetize environmental, health, and socio-economic externalities associated with the use of the material. Currently, CdS has a significant advantage over other alternate buffer materials in terms of efficiency and low-cost production of large-area processing of …

Blockchain-Based Healthcare: Three Successful Proof-Of-Concept Pilots Worth Considering, Rebecca Angeles

Journal of International Technology and Information Management

This paper features the use of blockchain technology in the healthcare industry, with special focus on healthcare data exchange and interoperability; drug supply chain integrity and remote auditing; and clinical trials and population health research. This study uses the research method of analyzing the published case studies, academic articles, trade articles, and videos on MEDRec, Patientory, and the AmerisourceBergen/Merck alliance with SAP/CryptoWerk. The “blockchain” concept was introduced around October 2008 when a proposal for the virtual currency, bitcoin, was offered. Blockchain is a much broader concept than bitcoin and has the following key attributes: distributed database; peer-to-peer transmission; transparency with …

Tuning The Reactivity Of Nanoenergetic Gas Generators Based On Bismuth And Iodine Oxidizers, Mkhitar A. Hobosyan, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

There is a growing interest on novel energetic materials called Nanoenergetic Gas- Generators (NGGs) which are potential alternatives to traditional energetic materials including pyrotechnics, propellants, primers and solid rocket fuels. NGGs are formulations that utilize metal powders as a fuel and oxides or hydroxides as oxidizers that can rapidly release large amount of heat and gaseous products to generate shock waves. The heat and pressure discharge, impact sensitivity, long term stability and other critical properties depend on the particle size and shape, as well as assembling procedure and intermixing degree between the components. The extremely high energy density and the …

Investigating The Use Of In-Place Lateral Pull Off Tests To Determine The Compressive Strength Of Structural Concrete, Charlie Sun

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet’s current practice for determining the compressive strength of structural concrete consists of two methods. Both methods require that samples be delivered to an off-site facility for testing. Accordingly, affected parties on the project site must wait for the delivery of samples to the off-site facility, the performance of tests and analysis of test data, and the return of test results to the project site. Analysis of existing structural concrete requires core samples to be taken from the structural element in question. As a result, sample locations must be patched and repaired. Sampling can also potentially damage …

Initiation Of Action Potential In Murine Ventricular Myocytes By Bursts Of Nanosecond Pulses, Iurii Semenov

Bioelectrics Publications

[First slide] Current situation

I. Among 300,000 persons die from sudden cardiac arrest every year over 40% are victims of fibrillation

II. Defibrillation by an electric shock is the effective therapy against sudden cardiac death

III. Current approach to stop fibrillation may involve disruption of plasma membrane (PM) by an electroporation

IV. Electroporation is damaging, it can: I. Induce post shock arrhythmias II. Complicate patient's recovery III. Lead to death after initially successful resuscitation

Building Energy Modeling And Techno-Economic Feasibility Analysis Of Zero Net Energy Tiny Homes In Coastal Humboldt County, California, Jeffrey Alan Harkness

Cal Poly Humboldt theses and projects

This thesis conducts a techno-economic feasibility analysis of tiny homes. Scenarios generated using a mathematical and physical model of energy use of zero-net energy tiny homes in coastal Humboldt County are compared with conventional energy systems powered by fossil-fuels for lifecycle economic cost, energy efficiency, greenhouse gas emissions, and energy use. A residence of 2,425 ft.² (near the regional average) is simulated to offer a broader standard of comparison. A tiny home village model with outlying bedrooms and a central building for cooking, laundry and shower facilities is compared to a standalone tiny home model. A community services building …

Nanosecond Pulsed Electric Signals Can Affect Electrostatic Environment Of Protiens Below The Threshold Of Conformational Effects: The Case Study Of Sod1 With A Molecular Simulation Study, Elena Della Valle, Paolo Marracino, Olga Pakhomova, Micaela Liberti, Francesca Apollonio

Bioelectrics Publications

Electric fields can be a powerful tool to interact with enzymes or proteins, with an intriguing perspective to allow protein manipulation. Recently, researchers have focused the interest on intracellular enzyme modifications triggered by the application of nanosecond pulsed electric fields. These findings were also supported by theoretical predictions from molecular dynamics simulations focussing on significant variations in protein secondary structures. In this work, a theoretical study utilizing molecular dynamics simulations is proposed to explore effects of electric fields of high intensity and very short nanosecond duration applied to the superoxide dismutase (Cu/Zn-SOD or SOD-1), an important enzyme involved in the …

Selective Distant Electrostimulation By Synchronized Bipolar Nanosecond Pulses, Elena C. Gianulis, Maura Casciola, Carol Zhou, Enbo Yang, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

A unique aspect of electrostimulation (ES) with nanosecond electric pulses (nsEP) is the inhibition of effects when the polarity is reversed. This bipolar cancellation feature makes bipolar nsEP less efficient at biostimulation than unipolar nsEP. We propose to minimize stimulation near pulse-delivering electrodes by applying bipolar nsEP, whereas the superposition of two phase-shifted bipolar nsEP from two independent sources yields a biologically-effective unipolar pulse remotely. This is accomplished by electrical compensation of all nsEP phases except the first one, resulting in the restoration of stimulation efficiency due to cancellation of bipolar cancellation (CANCAN-ES). We experimentally proved the CANCAN-ES paradigm by …

Intratumoral Delivery Of Plasmid Il12 Via Electroporation Leads To Regression Of Injected And Noninjected Tumors In Merkel Cell Carcinoma, Shailender Bhatia, Natalie V. Longino, Natalie J. Miller, Rima Kulikauskas, Jayasri G. Iyer, Dafina Ibrani, Astrid Blom, David R. Byrd, Upendra Parvathaneni, Christopher Twitty, Jean S. Campbell, Mai H. Le, Sharron Gargosky, Robert H. Pierce, Richard Heller, Adil Daud, Paul Nghiem

Bioelectrics Publications

Purpose: Interleukin-12 (IL12) promotes adaptive type I immunity and has demonstrated antitumor efficacy, but systemic administration leads to severe adverse events (AE), including death. This pilot trial investigated safety, efficacy, and immunologic activity of intratumoral delivery of IL12 plasmid DNA (tavo) via in vivo electroporation (i.t.-tavo-EP) in patients with Merkel cell carcinoma (MCC), an aggressive virus-associated skin cancer.

Experimental Design: Fifteen patients with MCC with superficial injectable tumor(s) received i.t.-tavo-EP on days 1, 5, and 8 of each cycle. Patients with locoregional MCC (cohort A, N = 3) received one cycle before definitive surgery in week 4. …

Nanosecond Pulsed Electric Fields Induce Endoplasmic Reticulum Stress Accompanied By Immunogenic Cell Death In Murine Models Of Lymphoma And Colorectal Cancer, Alessandra Rossi, Olga N. Pakhomova, Peter A. Mollica, Maura Casciola, Uma Mangalanathan, Andrei G. Pakhomov, Claudia Muratori

Bioelectrics Publications

Depending on the initiating stimulus, cancer cell death can be immunogenic or non-immunogenic. Inducers of immunogenic cell death (ICD) rely on endoplasmic reticulum (ER) stress for the trafficking of danger signals such as calreticulin (CRT) and ATP. We found that nanosecond pulsed electric fields (nsPEF), an emerging new modality for tumor ablation, cause the activation of the ER-resident stress sensor PERK in both CT-26 colon carcinoma and EL-4 lymphoma cells. PERK activation correlates with sustained CRT exposure on the cell plasma membrane and apoptosis induction in both nsPEF-treated cell lines. Our results show that, in CT-26 cells, the activity of …