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2020

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Full-Text Articles in Engineering

Performance Of Cracked Reinforced Concrete Pipes Subjected To Different Environmental Conditions, Bassam Hatem Karim Al-Lami Aug 2020

Performance Of Cracked Reinforced Concrete Pipes Subjected To Different Environmental Conditions, Bassam Hatem Karim Al-Lami

Civil Engineering Dissertations - Archive

Performance of reinforced concrete pipes, as a major part of the water and waste-water infrastructure, plays an important role in the resilience and sustainability of today’s modern cities. Cracks may appear in these pipes due to handling and placement and might affect their long-term performance due to corrosion concerns. Current practice for quality control after installation of these pipes is quite strict and any pipe with a crack width of more than 0.01" is not approved. The goal of this research project is to evaluate the performance of cracked reinforced concrete pipes subjected to saline environments with three different concentration …


Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong Aug 2020

Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong

Boise State University Theses and Dissertations

For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation …


Temporal And Spatial Analysis Of The Wage Gap For Women And Underrepresented Minorities In The Architecture, Engineering, And Construction (Aec) Workforce, Saba Nikkhah Manesh Aug 2020

Temporal And Spatial Analysis Of The Wage Gap For Women And Underrepresented Minorities In The Architecture, Engineering, And Construction (Aec) Workforce, Saba Nikkhah Manesh

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Architecture, Engineering, and Construction (AEC) industry has failed to solve persistent labor shortage problems or to fill the labor demand in the workforce by recruiting from untapped/underrepresented groups such as Women and Underrepresented Minorities (WUMs). There have been several studies on diversity and inclusion in the AEC industry, but the issue still persists, as the AEC industry has failed to solve these issues. If the industry better understands the status of wage gaps by gender and race, as well as how the industry has performed in terms of providing comparable wages for the workforce over time, along with the …


Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim Aug 2020

Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim

Faculty Publications

The COVID-19 pandemic resulted in significant social and economic impacts throughout the world. In addition to the health consequences, the impacts on travel behavior have also been sudden and wide ranging. This study describes the drastic changes in human behavior using the analysis of highway volume data as a representation of personal activity and interaction. Same-day traffic volumes for 2019 and 2020 across Florida were analyzed to identify spatial and temporal changes in behavior resulting from the disease or fear of it and statewide directives to limit person-to-person interaction. Compared to similar days in 2019, overall statewide traffic volume dropped …


Active Transportation And Health: Understanding The Impact Of Transportation-Related Physical Activity On Health, Sina Famili Aug 2020

Active Transportation And Health: Understanding The Impact Of Transportation-Related Physical Activity On Health, Sina Famili

Civil Engineering Dissertations - Archive

Car-oriented infrastructure in the U.S. leads to physically inactive lifestyles and negative health outcomes. To promote physical activity, public health officials encourage active transportation, namely biking and walking on daily trips. Previous studies proved that both perceived or self-assessed and objective health measures should be used to understand individuals’ health status. Therefore, this study uses the National Household Travel Survey (NHTS) data to understand the associations between perceived health and modal trip features including the number of trips, trip distance, and duration for auto, public transit, walk, and bike trips. Regarding the objective health, this dissertation uses one-week walking activities …


Development Of A Structural Design Methodology For Cementitious Sprayed Applied Pipe Linings In Gravity Storm Water Conveyance Conduits, Amin Darabnoush Tehrani Aug 2020

Development Of A Structural Design Methodology For Cementitious Sprayed Applied Pipe Linings In Gravity Storm Water Conveyance Conduits, Amin Darabnoush Tehrani

Civil Engineering Dissertations - Archive

Culverts are important components of the highway infrastructure. They form passageways through the embankment to convey storm water. Culverts are structurally designed to support superimposed earth loads or other fill materials as well as live loads. Corrugated metal pipes (CMPs) and reinforced concrete pipes (RCPs) are commonly used as culverts in the United States. Most of these culverts were installed four to five decades ago and have reached their design life. Spray applied pipe linings (SAPLs) are trenchless technology solutions for culvert rehabilitation that prevent further deterioration, such as corrosion, abrasion, etc., and can provide structural support for severely damaged …


Advancing Hydrologic And Hydraulic Understanding And Application Through Inundation Mapping And Estimation Of Losses, Jiaqi Zhang Aug 2020

Advancing Hydrologic And Hydraulic Understanding And Application Through Inundation Mapping And Estimation Of Losses, Jiaqi Zhang

Civil Engineering Dissertations - Archive

Flooding is the most frequent weather hazard that can cause serious fatalities and property damages worldwide. Climate change with extreme weather has further increased the impact from flooding and brought unprecedented challenges to engineering infrastructure and design. Scientists and engineers have used models to investigate and forecast the hydrologic and hydraulic responses to environmental changes in meteorological forcing and land use. With recent advances in sensing and computing technologies, models have been reaching higher levels of spatiotemporal granularity and scale. However, gaps exist between the scientific exploration and engineering practices. This doctoral study has been conducted to bridge such gaps …


Study Of New Transistor Architecture With Energy Filtering, Nnaemeka Mcdonald Eluagu Aug 2020

Study Of New Transistor Architecture With Energy Filtering, Nnaemeka Mcdonald Eluagu

Material Science and Engineering Theses - Archive

The thermodynamic limit of the subthreshold slope to 60mV/decade at 300K forces MOSFET devices to use high supply voltages (> 0.5V) and therefore dissipate a lot of energy. This physical limitation of transistors is a direct consequence of thermal excitation of electrons. This study investigates a new transistor architecture capable of suppressing thermally excited electrons using a quantum well as an energy filter. The energy filter consists of a 2nm SiO2 tunneling barrier and a 2nm Quantum Well (QW) layer of Cr2O3 sandwiched between Ni electrodes and a channel of Si. Transistors having this QW energy filter have been fabricated …


Investigation Of High-Temperature Oxidation Resistance Mechanism Of Ceramic Coatings Via Microstructure Analysis, Yi Shen Aug 2020

Investigation Of High-Temperature Oxidation Resistance Mechanism Of Ceramic Coatings Via Microstructure Analysis, Yi Shen

Material Science and Engineering Dissertations - Archive

Recent developments of ceramic coatings deposited using magnetron reactive sputtering show that these films exhibited superior high-temperature oxidation resistance along with other desirable properties such as high hardness, optical transparency and good electrical conductivity. Detailed microstructure study of these films annealed to high temperatures using transmission electron microscopy (TEM) is deemed necessary as it provides an intuitive vision on the behavior of the materials at elevated temperature, which is essential to further improve their high-temperature oxidation resistance. In this study, Hf-B-Si-C-N films with various compositions that were annealed to various temperatures in both helium and air were subjected to detailed …


Need Based Evaluation Of Cloud Services In The Wake Of Covid-19, Samir Souidi, Stanley Mierzwa Aug 2020

Need Based Evaluation Of Cloud Services In The Wake Of Covid-19, Samir Souidi, Stanley Mierzwa

Center for Cybersecurity

For many organizations, particularly those that may be considered legacy, or older existing enterprises, the recent COVID-19 pandemic may be pushing them to further progress into the realm of cloud services. With the global population asked to quarantine or shelter-in-place during the pandemic spread of 2020, many businesses that were able to function with their workforce remotely had no choice but to do so. Having information systems available with true remote access capabilities was a must. For those organizations who had already moved to a cloud-based model, they found themselves in a far better situation than those firms who still …


Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight Aug 2020

Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this dissertation, optical Hall effect (OHE) measurements are used to determine the free charge carrier properties of important two-dimensional materials and monoclinic oxides. Two-dimensional material systems have proven useful in high-frequency electronic devices due to their unique properties, such as high mobility, which arise from their two-dimensional nature. Monoclinic oxides exhibit many desirable characteristics, for example low-crystal symmetry which could lead to anisotropic carrier properties. Here, single-crystal monoclinic gallium oxide, an AlInN/GaN-based high-electron-mobility transistor (HEMT) structure, and epitaxial graphene are studied as examples. To characterize these material systems, the OHE measurement technique is employed. The OHE is a physical …


Enhanced Control Algorithms In Permanent Magnet Synchronous Machines, Haibo Li Aug 2020

Enhanced Control Algorithms In Permanent Magnet Synchronous Machines, Haibo Li

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Permanent magnet synchronous machines (PMSMs) are gaining increasing popularity in various applications due to their advantages, such as high efficiency, high power density, and superior control performance. A well-designed machine control algorithm is indispensable for a PMSM system to secure its good performance.

In this work, enhanced control algorithms in PMSMs are developed. Online machine current trajectory tracking, source power management, hardware overcurrent regulation, and machine current sensor fault detection and isolation (FDI) are included in the developed algorithms. The online machine current trajectory tracking ensures the maximum torque per ampere (MTPA) or maximum torque per voltage (MTPV) control in …


An End-To-End Trainable Method For Generating And Detecting Fiducial Markers, J. Brennan Peace Aug 2020

An End-To-End Trainable Method For Generating And Detecting Fiducial Markers, J. Brennan Peace

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Existing fiducial markers are designed for efficient detection and decoding. The methods are computationally efficient and capable of demonstrating impressive results, however, the markers are not explicitly designed to stand out in natural environments and their robustness is difficult to infer from relatively limited analysis. Worsening performance in challenging image capture scenarios - such as poorly exposed images, motion blur, and off-axis viewing - sheds light on their limitations. The method introduced in this work is an end-to-end trainable method for designing fiducial markers and a complimentary detector. By introducing back-propagatable marker augmentation and superimposition into training, the method learns …


Cyber-Assets At Risk (Car): Monetary Impact Of Personally Identifiable Information Data Breaches On Companies, Omer Ilker Poyraz Aug 2020

Cyber-Assets At Risk (Car): Monetary Impact Of Personally Identifiable Information Data Breaches On Companies, Omer Ilker Poyraz

Engineering Management & Systems Engineering Theses & Dissertations

Cyber-systems provide convenience, ubiquity, economic advantage, and higher efficiency to both individuals and organizations. However, vulnerabilities of the cyber domain also offer malicious actors with the opportunities to compromise the most sensitive information. Recent cybersecurity incidents show that a group of hackers can cause a massive data breach, resulting in companies losing competitive advantage, reputation, and money. Governments have since taken some actions in protecting individuals and companies from such crime by authorizing federal agencies and developing regulations. To protect the public from losing their most sensitive records, governments have also been compelling companies to follow cybersecurity regulations. If companies …


Residual-Based Multi-Filter Methodology For All-Source Fault Detection, Exclusion, And Performance Monitoring, Juan Jurado, John F. Raquet, Christine M. Schubert Kabban Air Force Institute Of Technology, Jonathon S. Gipson Aug 2020

Residual-Based Multi-Filter Methodology For All-Source Fault Detection, Exclusion, And Performance Monitoring, Juan Jurado, John F. Raquet, Christine M. Schubert Kabban Air Force Institute Of Technology, Jonathon S. Gipson

Faculty Publications

All-source navigation has become increasingly relevant over the past decade with the development of viable alternative sensor technologies. However, as the number and type of sensors informing a system increases, so does the probability of corrupting the system with sensor modeling errors, signal interference, and undetected faults. Though the latter of these has been extensively researched, the majority of existing approaches have constrained faults to biases and designed algorithms centered around the assumption of simultaneously redundant, synchronous sensors with valid measurement models, none of which are guaranteed for all-source systems. As part of an overall all-source assured or resilient navigation …


Model-Based Approach For Diffuse Glioma Classification, Grading, And Patient Survival Prediction, Zeina A. Shboul Aug 2020

Model-Based Approach For Diffuse Glioma Classification, Grading, And Patient Survival Prediction, Zeina A. Shboul

Electrical & Computer Engineering Theses & Dissertations

The work in this dissertation proposes model-based approaches for molecular mutations classification of gliomas, grading based on radiomics features and genomics, and prediction of diffuse gliomas clinical outcome in overall patient survival. Diffuse gliomas are types of Central Nervous System (CNS) brain tumors that account for 25.5% of primary brain and CNS tumors and originate from the supportive glial cells. In the 2016 World Health Organization’s (WHO) criteria for CNS brain tumor, a major reclassification of the diffuse gliomas is presented based on gliomas molecular mutations and the growth behavior. Currently, the status of molecular mutations is determined by obtaining …


A Core Reference Hierarchical Primitive Ontology For Electronic Medical Records Semantics Interoperability, Ziniya Zahedi Aug 2020

A Core Reference Hierarchical Primitive Ontology For Electronic Medical Records Semantics Interoperability, Ziniya Zahedi

Engineering Management & Systems Engineering Theses & Dissertations

Currently, electronic medical records (EMR) cannot be exchanged among hospitals, clinics, laboratories, pharmacies, and insurance providers or made available to patients outside of local networks. Hospital, laboratory, pharmacy, and insurance provider legacy databases can share medical data within a respective network and limited data with patients. The lack of interoperability has its roots in the historical development of electronic medical records. Two issues contribute to interoperability failure. The first is that legacy medical record databases and expert systems were designed with semantics that support only internal information exchange. The second is ontological commitment to the semantics of a particular knowledge …


Secure Mobile Computing By Using Convolutional And Capsule Deep Neural Networks, Rui Ning Aug 2020

Secure Mobile Computing By Using Convolutional And Capsule Deep Neural Networks, Rui Ning

Electrical & Computer Engineering Theses & Dissertations

Mobile devices are becoming smarter to satisfy modern user's increasing needs better, which is achieved by equipping divers of sensors and integrating the most cutting-edge Deep Learning (DL) techniques. As a sophisticated system, it is often vulnerable to multiple attacks (side-channel attacks, neural backdoor, etc.). This dissertation proposes solutions to maintain the cyber-hygiene of the DL-Based smartphone system by exploring possible vulnerabilities and developing countermeasures.

First, I actively explore possible vulnerabilities on the DL-Based smartphone system to develop proactive defense mechanisms. I discover a new side-channel attack on smartphones using the unrestricted magnetic sensor data. I demonstrate that attackers can …


Possible Self Dynamics Of Community College Students Engaged In 3d Printing In Informal Environments, Lawrence Ralph Nightingale Jr. Aug 2020

Possible Self Dynamics Of Community College Students Engaged In 3d Printing In Informal Environments, Lawrence Ralph Nightingale Jr.

Educational Leadership & Workforce Development Theses & Dissertations

The overall number of students from diverse backgrounds and women that graduate from community college with degrees in high paying Science Technology Engineering and Mathematics (STEM) disciplines is unacceptably low. The number of opportunities to gain exposure to STEM-based expressions of technology to overcome the dearth of exposure in high school is limited in community college. 3D Printing uses computer-controlled machines to build physical objects one layer at a time starting from the bottom up. The computer-controlled nature of 3D Printing provides a low risk, low cost platform to exercise elements of computer programming and engineering.

This study was a …


Towards Dynamic Vehicular Clouds, Aida Ghazizadeh Aug 2020

Towards Dynamic Vehicular Clouds, Aida Ghazizadeh

Computer Science Theses & Dissertations

Motivated by the success of the conventional cloud computing, Vehicular Clouds were introduced as a group of vehicles whose corporate computing, sensing, communication, and physical resources can be coordinated and dynamically allocated to authorized users. One of the attributes that set Vehicular Clouds apart from conventional clouds is resource volatility. As vehicles enter and leave the cloud, new computing resources become available while others depart, creating a volatile environment where the task of reasoning about fundamental performance metrics becomes very challenging. The goal of this thesis is to design an architecture and model for a dynamic Vehicular Cloud built on …


Human Error In Commercial Fishing Vessel Accidents: An Investigation Using The Human Factors Analysis And Classification System, Peter J. Zohorsky Aug 2020

Human Error In Commercial Fishing Vessel Accidents: An Investigation Using The Human Factors Analysis And Classification System, Peter J. Zohorsky

Engineering Management & Systems Engineering Theses & Dissertations

The commercial fishing industry is frequently described as one of the most hazardous occupations in the United States. The objective, to maximize the catch, is routinely challenged by a variety of elements due to the environment, the vessel, the crew, and several external considerations and how they interact with each other. The analysis of fishing vessel accidents can be complicated due to the diverse nature of the industry, including the species caught, the type and size of boat that is employed, how far travelled from their homeport, and the adequacy of the support organizations ensuring safe and uninterrupted operations. This …


Deep Learning For Remote Sensing Image Processing, Yan Lu Aug 2020

Deep Learning For Remote Sensing Image Processing, Yan Lu

Computational Modeling & Simulation Engineering Theses & Dissertations

Remote sensing images have many applications such as ground object detection, environmental change monitoring, urban growth monitoring and natural disaster damage assessment. As of 2019, there were roughly 700 satellites listing “earth observation” as their primary application. Both spatial and temporal resolutions of satellite images have improved consistently in recent years and provided opportunities in resolving fine details on the Earth's surface. In the past decade, deep learning techniques have revolutionized many applications in the field of computer vision but have not fully been explored in remote sensing image processing. In this dissertation, several state-of-the-art deep learning models have been …


Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters In Resonance And Off-Resonance Modes, Mohamed A. Shabara Aug 2020

Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters In Resonance And Off-Resonance Modes, Mohamed A. Shabara

Mechanical & Aerospace Engineering Theses & Dissertations

Energy harvesting technologies are integrated into various modern devices and systems. These systems include Artificial Intelligence (AI) systems, Internet of Things (IoT), various types of energy harvesters are integrated in many engineering applications such as automotive, aerospace and ocean engineering. In order to develop a fully functioning stand-alone system, it is essential to integrate it with a built in power source such as a battery or a power generator. Also, in many situations, city power sources might not be available. Therefore, reliable, renewable and sustainable local power generators are desired. Piezoelectric energy harvesting (PEH) technologies, which are piezoelectric material-based devices, …


Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo Aug 2020

Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo

Mechanical & Aerospace Engineering Theses & Dissertations

With an ever-increasing demand for composites, more ways of manufacturing them are becoming popular and widely used. Stitching of dry fabrics is an efficient method for improving delamination resistance. Discontinuous fiber reinforced composites can be used as a lightweight alternative material for metals through a process of compression molding, which allows for complex shape manufacturing while offering structural grade mechanical properties.

This study demonstrates how the stitching of dry fabrics can be adapted to more complex surfaces. The consequences of stitching of curvilinear surfaces can result in defect formation. Therefore, to understand the physical formation of possible defects, experimental characterization …


A Quest To Identify The Emerging Leadership Skills In Vuca World And Investigation Of Their Applications In Various Organizational Levels And Security Environments, Ali Can Kucukozyigit Aug 2020

A Quest To Identify The Emerging Leadership Skills In Vuca World And Investigation Of Their Applications In Various Organizational Levels And Security Environments, Ali Can Kucukozyigit

Engineering Management & Systems Engineering Theses & Dissertations

The theoretical framework of this research is based on “skills approach” that emphasizes the leader’s capabilities (skills, knowledge, and capabilities) that can be learned, taught, and fostered. VUCA (Volatile, Uncertain, Complex and Ambiguous) environment is chosen as the focal point of this research as the leadership skills are extracted from studies referring to such environment. Although the acronym is dominantly used in management and business domains, the military also uses it to describe the complex operational environments like in Iraq and Afghanistan. The identification of individual leadership skills and delivering the right skill, at the right time, to the right …


Validation Of Nanosecond Pulse Cancellation Using A Quadrupole Exposure System, Hollie A. Ryan Aug 2020

Validation Of Nanosecond Pulse Cancellation Using A Quadrupole Exposure System, Hollie A. Ryan

Biomedical Engineering Theses & Dissertations

Nanosecond pulsed electric fields (nsPEFs) offer a plethora of opportunities for developing integrative technologies as complements or alternatives to traditional medicine. Studies on the biological effects of nsPEFs in vitro and in vivo have revealed unique characteristics that suggest the potential for minimized risk of complications in patients, such as the ability of unipolar nsEPs to create permanent or transient pores in cell membranes that trigger localized lethal or non-lethal outcomes without consequential heating. A more recent finding was that such responses could be diminished by applying a bipolar pulse instead, a phenomenon dubbed bipolar cancellation, paving the way …


Do Different Pathologies Affect The Relationship Between The Stiffness Of The Plantar Fascia And The Function Of The Mtp Joint?, Madeline Ryan Pauley Aug 2020

Do Different Pathologies Affect The Relationship Between The Stiffness Of The Plantar Fascia And The Function Of The Mtp Joint?, Madeline Ryan Pauley

Biomedical Engineering Theses & Dissertations

Compared to healthy individuals, individuals with plantar fasciitis and diabetes experience material and structural property changes to soft tissues in the feet. The purpose of this study was to compare the relationship between material properties, power absorption, and energy storage characteristics to metatarsal power between healthy, plantar fasciitis symptomatic and asymptomatic, and diabetic participants. Investigating material change differences as well as energy storage and transfer trends in different pathology groups can lead to a better overall understanding of power transfer at the metatarsophalangeal joint (MTP). Participants were recruited for kinematic gait analysis and lower extremity shear wave elastography analysis and …


Life Cycle Assessment Of The Us Beef Processing Through Integrated Hybrid Approach, Shaobin Li, Yuwei Qin, Jeyamkondan Subbiah, Bruce Dvorak Aug 2020

Life Cycle Assessment Of The Us Beef Processing Through Integrated Hybrid Approach, Shaobin Li, Yuwei Qin, Jeyamkondan Subbiah, Bruce Dvorak

Department of Civil and Environmental Engineering: Faculty Publications

Hybrid life cycle assessment (LCA) incorporating process-based and economic input-output (EIO)–based inventory data has been applied in various industries (e.g., wind energy, biofuel). Few hybrid LCA studies have been found in the food industry. This work analyzes the life cycle environmental impacts of the US beef processing industry using process-based and integrated hybrid LCA. The process-based inventory includes all resource inputs and waste outputs associated with a beef processing plant. The EIO-based inventory includes key activities missing in the process-based inventory, such as technical and management service, wood and paper, and industrial equipment. Ten environmental impact categories from TRACI v2.1 …


Minimum Induced Drag For Tapered Wings Including Structural Constraints, Jeffrey D. Taylor, Douglas F. Hunsaker Aug 2020

Minimum Induced Drag For Tapered Wings Including Structural Constraints, Jeffrey D. Taylor, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

LIFTING-LINE theory [1,2] is the foundation for much of our understanding of finite-wing aerodynamics. Solutions based on lifting-line theory are widely accepted and have been shown to be in good agreement with CFD [3-10]. From Prandtl’s analytic solution to the classical lifting-line equation [1,2], the wing section-lift distribution can be expressed as a Fourier series of the form [11]

bL~ (θ)/L = (4/π)[sin(θ) + Σ∞n-2 Bnsin(nθ)]; θ = cos-1(-2z/b) (1)

where b is the wingspan, L~ is the local wing section lift, L is the total wing lift, z is the spanwise …


The Structural And Magnetic Properties Of Nio/Mn(Ni)-Oxide Magnetic Heterostructured Nanocrystals Synthesized Under Varying Ph Values, Abdullah Al Shafe Aug 2020

The Structural And Magnetic Properties Of Nio/Mn(Ni)-Oxide Magnetic Heterostructured Nanocrystals Synthesized Under Varying Ph Values, Abdullah Al Shafe

Graduate Theses/Dissertations

The role of pH on the structural, morphological, and magnetic properties of hydrothermally synthesized NiO-based magnetic heterostructured nanocrystals (MHNCs) is investigated. The NiO nanocrystals were synthesized using a two-step thermal decomposition process whereas the deposition of the surrounding Mn-based phases was accomplished by hydrothermal means at pH values ranging from 2.4 to 7.0. The resulting heterostructured nanocrystals consist of inverted AFM-FiM NiO/±MnxNi1-xO/±Mn3O4 bimagnetic/trimagnetic systems. A complete characterization of the MHNCs was carried using XRD, TEM, EDS, MPMS magnetometry and XPS analysis. Structural investigations revealed predominantly faceted MHNCs ranging in size from 24-30 nm …