Engineering Commons^™

Bioresorbable Composite Stents For Enhanced Response Of Vascular Smooth Muscle Cells, Hozhabr Mozafari

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Formation of arterial plaque and stenosis is one of the main cardiovascular disease risk factors. Stenting is a popular approach to increase the inner diameter of the artery and provide an acceptable lumen gain. This is achieved by applying internal pressure to the arterial wall. Despite the desirable outcomes of this procedure, there are complexities and challenges that are being discussed among scholars in this area. Restenosis is one of these complications, in which smooth muscles cell start proliferation and remodeling in response of induced mechanical stresses. Another important issue is the placement of the stent and possible migration due …

Magnetic Properties Of Nd-Fe-B Permanent Magnets Under Thermal Experimentation, Géraldine Houis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Neodymium-Iron-Boron (Nd-Fe-B) magnets were developed in the 1980s, and since then, they have appeared as a common component in many fields. From the industry to consumers or defense applications, from turbines, computers, cellphones to most audio systems, Nd-Fe-B magnets are present everywhere. But when Nd-Fe-B magnets are applied to the motors of electric vehicles and wind-turbine generators, their temperature rises, therefore Nd-Fe-B-Dy magnets are used. However, while the use of these magnets is common at low temperatures, their properties decrease dramatically with the increase of temperature. In this paper, the Nd-Fe-B-based samples used were prepared by using arc melting, melt …

The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Conventional nondestructive delamination detection of concrete pavements through thermography is often based on temperature contrasts between delaminated and sound areas. Non-uniform backgrounds caused by the environmental conditions are often challenging for contrast-based methods to robustly differentiate the delaminated areas from the sound areas. Instead of focusing on the temperature contrast, this study proposes a temperature gradient-based level set method (LSM) to detect boundaries for delamination segmentations. A modified edge indicator function is developed to represent the normalized temperature gradient of a thermal image. The experimental study was conducted to evaluate its applicability and stability for boundary detection in terms of …

Predicting Agricultural Implement Hydraulic Power Demand Using Synchronized Controller Area Network And Ancillary Sensor Data, Gabriel P. Stoll

Department of Biological Systems Engineering: Dissertations and Theses

As agricultural implement designs have progressed in recent years, there has been an increase in hydraulic power demand from the tractor. Current power estimation standards do not accurately estimate hydraulic power demand for implements designed with higher hydraulic power requirements. Several stakeholders, including agricultural producers, tractor and implement manufacturers, and government agencies would benefit from accurate published data on these power requirements.

While an increasing amount of operational data available on the Controller Area Network (CAN) of tractors has assisted researchers in more easily obtaining machinery performance data, hydraulic control valve flow rate and pressure measurements are not currently publically …

Multi-Scale Modeling Of The Lamellar Unit Of Arterial Media, Hozhabr Mozafari, Lulu Wang, Yuguo Lei, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The heterogeneity of the lamellar unit (LU) of arterial media plays an important role in the biomechanics of artery. Current two-component (fibrous component and a homogenous matrix) constitutive model is inappropriate for capturing the micro-structural variations in the LU, such as contraction/relaxation of vascular smooth muscle cells (VSMCs), fragmentation of the elastin layer, and deposition/disruption of the collagen network. In this work, we developed a representative volume element (RVE) model with detailed micro-configurations, i.e., VSMCs at various phenotypes, collagen fibers, and elastin laminate embedded in the ground substance. The fiber architecture was generated based on its volume fraction and orientations. …

Water Pipeline Leakage Detection Based On Machine Learning And Wireless Sensor Networks, Yang Liu, Xuehui Ma, Yong Tie, Yinghui Zhang, Jing Gao

Department of Electrical and Computer Engineering: Faculty Publications

The detection of water pipeline leakage is important to ensure that water supply networks can operate safely and conserve water resources. To address the lack of intelligent and the low efficiency of conventional leakage detection methods, this paper designs a leakage detection method based on machine learning and wireless sensor networks (WSNs). The system employs wireless sensors installed on pipelines to collect data and utilizes the 4G network to perform remote data transmission. A leakage triggered networking method is proposed to reduce the wireless sensor network’s energy consumption and prolong the system life cycle effectively. To enhance the precision and …

Machine Current Sensor Fdi Strategy In Pmsms, Haibo Li, Yi Qian, Sohrab Asgarpoor, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

This work proposes a machine current sensor fault detection and isolation (FDI) strategy in permanent magnet synchronous machines (PMSMs) resilient to multiple faults. The fault detection is performed by comparing the measured and estimated DC link currents. The fault isolation is achieved according to machine phase signal estimation and the corresponding residual examination. Single sensor fault, multiple sensor faults and non-sensor fault are covered by the proposed FDI method. The proposed sensor FDI method is not influenced by machine imbalance, feasible for FDI of both single and multiple machine current sensor faults, and capable of distinguishing between machine current sensor …

Bibliometric Survey Of Privacy Of Social Media Network Data Publishing, Rupali Gangarde Ass. Prof., Amit Sharma Dr., Ambika Pawar Dr.

Library Philosophy and Practice (e-journal)

We are witness to see exponential growth of the social media network since the year 2002. Leading social media networking sites used by people are Twitter, Snapchats, Facebook, Google, and Instagram, etc. The latest global digital report (Chaffey and Ellis-Chadwick 2019) states that there exist more than 800 million current online social media users, and the number is still exploding day by day. Users share their day to day activities such as their photos and locations etc. on social media platforms. This information gets consumed by third party users, like marketing companies, researchers, and government firms. Depending upon the purpose, …

The Art Of Selecting Phd Students: Combination Of Bibliometric And Ahp Approach, Preeti Mulay Dr., Rahul Raghvendra Joshi Prof., Sophia Gaikwad Dr.

Library Philosophy and Practice (e-journal)

For the PhD guide or the advisor selecting the accurate PhD scholar is the most elephantine task. It actually requires an art for the perfect selection; as the length, breadth, depth and volume of PhD work is spread across the years and this relationship between the scholar and the guide should start and flourish positively for the immense experience throughout the PhD process. Hence it was essential to understand bibliometric details including how many researchers have already published their contributions in the form of papers and patents, in the Scopus database. In addition to the bibliometric details, in this study, …

Personality Prediction Through Curriculam Vitae Analysis Involving Password Encryption And Prediction Analysis, Gagandeep Kaur, Shruti Maheshwari

Library Philosophy and Practice (e-journal)

A recruitment process requires an eligibility check, an aptitude evaluation and a psychometric analysis of prospective candidates. The work puts forward an application where the system allows employers to post new job offerings and registered candidates can apply. The application estimates applicant’s emotional aptitude through a psychometric analysis based on a test whereas the professional standard is verified via a technical aptitude test. OCEAN Model is used to assess emotional quotient and predict the personality traits. Machine learning techniques such as Logistic Regression are used for modelling the personality predictor. The details of the candidates are kept secure by using …

A Co-Optimal Coverage Path Planning Method For Aerial Scanning Of Complex Structures, Zhexiong Shang, Justin Bradley, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

The utilization of unmanned aerial vehicles (UAVs) in survey and inspection of civil infrastructure has been growing rapidly. However, computationally efficient solvers that find optimal flight paths while ensuring high-quality data acquisition of the complete 3D structure remains a difficult problem. Existing solvers typically prioritize efficient flight paths, or coverage, or reducing computational complexity of the algorithm – but these objectives are not co-optimized holistically. In this work we introduce a co-optimal coverage path planning (CCPP) method that simultaneously co-optimizes the UAV path, the quality of the captured images, and reducing computational complexity of the solver all while adhering to …

The Stability Analysis For Wind Turbines With Doubly Fed Induction Generators, Baohua Dong

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

The quickly increasing, widespread use of wind generation around the world reduces carbon emissions, decreases the effects of global warming, and lowers dependence on fossil fuels. However, the growing penetration of wind power requires more effort to maintain power systems stability.

This dissertation focuses on developing a novel algorithm which dynamically optimizes the proportional-integral (PI) controllers of a doubly fed induction generator (DFIG) driven by a wind turbine to increase the transient performance based on small signal stability analysis.

Firstly, the impact of wind generation is introduced. The stability of power systems with wind generation is described, including the different …

Adding Value To Lignocellulosic Biorefinery: Efficient Process Development Of Lignocellulosic Biomass Conversion Into Polyhydroxybutyrate, Mengxing Li

Department of Biological Systems Engineering: Dissertations and Theses

Polyhydroxybutyrate (PHB) is bacteria synthesized polymer that has comparable mechanical properties as petroleum-based plastics and high biocompatibility. Current commercial PHB production process is not cost effective. Raw materials make up about 50% of the production cost. Lignocellulosic biomass are cheap, abundant feedstocks that can be converted into PHB to add profit and sustainability to lignocellulosic biorefinery. Lignocellulosic biorefinery upstream process produces polymeric sugar rich stream and lignin-enriched stream. Polymeric sugars are then hydrolyzed into a sugar stream with glucose, xyloseand arabinose mainly present. To the best of the author’s knowledge, limited studies have been done on sugar mixture conversion into …

Enhancing Single Walled Carbon Nanotube Deposition For The Study Of Extracellular Analytes, Joseph A. Stapleton

Department of Biological Systems Engineering: Dissertations and Theses

Extracellular signaling is a dynamic process responsible for coordinating large scale biological processes. As such, understanding extracellular signaling is important to our determination of normal function and pathophysiological development. High resolution spatial and temporal information are critical to completely understanding these processes. Unfortunately, current methods of detection are lacking in either spatial or temporal resolution of extracellular products, limiting researchers’ ability to understand complex biological processes. A new group of sensors based on fluorescent single walled carbon nanotubes (SWNT) have shown the potential to provide both high quality spatial and temporal resolution for the sensing of analytes. However, while SWNT …

Double-Sided Corrugated Composite Tube And Axle Protective Mechanism For Railway Vehicles, Hozhabr Mozafari

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Structural elements in transportation vehicles are exposed to different types of dynamic loadings and impact scenarios. Protecting passengers against injury and providing mechanisms to avoid impact induced damages to the critical components are the two hot topics in crashworthiness engineering. The presented research work includes two parts. The first part is about designing a novel double-sided composite corrugated tube that can be implemented in front chassis rail of ground vehicles to improve their crashworthiness against collision and car accidents. To maximize the controllable energy absorption of corrugation troughs as observed in the single sided corrugated (SSC) tube, we proposed and …

Global Research Trend On Cyber Security: A Scientometric Analysis, Somesh Rai, Kunwar Singh Dr, Akhilesh Kumar Varma

Library Philosophy and Practice (e-journal)

Scientometrics is a quantitative analysis of scholarly literature related to a particular subject or area (well defined by some limits, scope and coverage), which helps to understand different aspects about the scholarly literature’s growth in various dimensions of knowledge. Similarly, this study is a quantitative analysis of the Global research trends in cyber security. Some works related to scientometrics of ‘deception, counter-deception in cyberspace’ had been published in 2011, but we have focused on ‘cyber security’ as the topic of research. For analysis we have utilised the published data available in Scopus database, which is directly related to ‘cyber security’. …

The Business Case For Industrial Safety: Revealing The Comprehensive Value Of Ergonomic Investments For Manufacturing Enterprises In Industry 4.0, Shane Stan

Honors Theses

How can today’s manufacturing enterprises construct, implement, and optimize modern safety initiatives in a manner that will present maximum return on investment and facilitate enterprise growth? Furthermore, how can these manufacturers assure individual ergonomic investments become part of a larger strategy to facilitate organizational change in safety? This work addresses these questions by placing industrial ergonomics in a business improvement context which comprehensively presents the financial returns and growth opportunities poised by modern safety initiatives. Additionally, to further strengthen the business case for industrial safety, an ergonomic action planning framework is established to guide the creation of holistic safety programs …

Investigation Of Oxygen Reduction Reaction In Carbon-Based Electrocatalysts, Andrew Mason

Honors Theses

In the modern era, some global challenges are energy storage conversion. To find sustainable solutions to this problem, researchers have turned to renewable energy resources. An example of promising energy generation devices is fuel cell. Fuel cells are electrochemical systems that convert the chemical energy of the fuel to electrochemical potential that can be used as direct current (dc) generators. Although these technologies are very attractive, they are known to be expensive due to high cost of catalysts and concerns regarding their energy densities. Fuel cells composed of two electrodes, namely cathode and anode and electrolyte separating the oxidizing agents …

Beyond The Toolpath: Site-Specific Melt Pool Size Control Enables Printing Of Extra-Toolpath Geometry In Laserwire-Based Directed Energy Deposition, Brian T. Gibson, Bradley S. Richardson, Tayler W. Undermann, Lonnie J. Love

Department of Mechanical and Materials Engineering: Faculty Publications

A variety of techniques have been utilized in metal additive manufacturing (AM) for melt pool size management, including modeling and feed-forward approaches. In a few cases, closed-loop control has been demonstrated. In this research, closed-loop melt pool size control for large-scale, laser wire-based directed energy deposition is demonstrated with a novel modification, i.e., site-specific changes to the controller setpoint were commanded at trigger points, the locations of which were generated by the projection of a secondary geometry onto the primary three-dimensional (3D) printed component geometry. The present work shows that, through this technique, it is possible to print a specific …

Effect Of Silica Fume In Concrete On Mechanical Properties And Dynamic Behaviors Under Impact Loading, Shijun Zhao, Qing Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

The effect of silica fume (SF) in concrete on mechanical properties and dynamic behaviors was experimentally studied by split Hopkinson pressure bar (SHPB) device with pulse shaping technique. Three series of concrete with 0, 12%, and 16% SF as a cement replacement by weight were produced firstly. Then the experimental procedure for dynamic tests of concrete specimens with SF under a high loading rate was presented. Considering the mechanical performance and behaviors of the concrete mixtures, those tests were conducted under five different impact velocities. The experimental results clearly show concrete with different levels of SF is a strain-rate sensitive …

Perceptions Of Higher Education In Nonmetropolitan Nebraska: Research Report 19‐4, Rebecca Vogt, Cheryl Burkhart-Kriesel, Randolph L. Cantrell, Bradley Lubben, L. J. Mcelravy, Tim L. Meyer, Jason L. Weigle

Rural Futures Institute: Publications

Some recent national polls have shown a decline in confidence in higher education. The cited reasons for this decline are concerns about affordability, access and the political culture on campuses. Given these national trends, how do rural Nebraskans view the impacts of their education? Do they view higher education as important for individuals and the economy? Have these views changed over the past four years? What types of higher education institutions have their households attended? This paper provides a detailed analysis of these questions. This report details 1,776 responses to the 2019 Nebraska Rural Poll, the 24th annual effort to …

Smart Additive Manufacturing: In-Process Sensing And Data Analytics For Online Defect Detection In Metal Additive Manufacturing Processes, Mohammad Montazeri

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The goal of this dissertation is to detect the incipient flaws in metal parts made using additive manufacturing processes (3D printing). The key idea is to embed sensors inside a 3D printing machine and conclude whether there are defects in the part as it is being built by analyzing the sensor data using artificial intelligence (machine learning). This is an important area of research, because, despite their revolutionary potential, additive manufacturing processes are yet to find wider acceptance in safety-critical industries, such as aerospace and biomedical, given their propensity to form defects. The presence of defects, such as porosity, can …

Evaluation Of Internally Cured Bridge Deck Concrete With Standard And Optimized Aggregate Gradation, Arman Abdigaliyev

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research developed internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. The study focused on resolving two issues associated with fine aggregate replacement based on Bentz equation. To identify the …

Take Off To Superiority: The Evolution & Impact Of U.S. Aircraft In War, Lane Weidner

Honors Theses

Military aviation has become a staple in the way wars are fought, and ultimately, won. This research paper takes a look at the ways that aviation has evolved and impacted wars across the U.S. history timeline. With a brief introduction of early flight and the modern concept of an aircraft, this article then delves into World Wars I and II, along with the Cold, Korean, Vietnam, and Gulf Wars. The current War on Terrorism is then investigated, and finally, a look toward the future. Topics covered include the newest aircraft of each era, technological advancements, and how strategy and war …

Removal Of Selected Pharmaceuticals And Personal Care Products In Wastewater Treatment Plant In Jordan, Othman Al-Mashaqbeh, Diya Alsafadi, Sahar Dalahmeh, Shannon L. Bartelt-Hunt, Daniel D. Snow

Nebraska Water Center: Faculty Publications

The largest wastewater treatment plant in Jordan was monitored in the summer to determine the removal of pharmaceuticals and personal care products (PPCPs). Grab samples were collected from the influent and effluent of As-Samra Wastewater Treatment Plant (WWTP). Liquid chromatography and tandem mass spectrometry (LC–MS/MS) were utilized to determine the concentrations of 18 compounds of pharmaceuticals and personal care products (PPCPs). The results showed that 14 compounds were detected in the collected samples from the influent and effluent of As-Samra WWTP. These compounds are 1,7-dimethylxanthine, amphetamine, acetaminophen, caffeine, carbamazepine, cimetidine, cotinine, diphenhydramine, methylenedioxymethamphetamine (MDMA), morphine, phenazone, sulfamethazine, sulfamethoxazole, thiabendazole, and …

System And Method For Sensing Wind Flow Passing Over Complex Terrain, Saleh Nabi, Piyush Grover, Mithu Debnath

Department of Mechanical and Materials Engineering: Faculty Publications

A wind flow sensing system determines a first approximation of the velocity field at each of the altitudes by simulating computational fluid dynamics ( CFD ) of the wind flow with operating parameters reducing a cost function of a weighted combination of errors , determines a horizontal derivative of vertical velocity at each of the altitudes from the first approximation of the velocity fields , and determines a second approximation of the velocity fields using geometric relationships between a velocity field for each of the altitudes , projections of the measurements of radial velocities on the three - dimensional axes …

Hybrid Superhydrophilic–Superhydrophobic Micro/ Nanostructures Fabricated By Femtosecond Laserinduced Forward Transfer For Sub-Femtomolar Raman Detection, Xiaodan Ma, Lan Jiang, Xiaowei Li, Bohong Li, Ji Huang, Jiaxing Sun, Zhi Wang, Zhijie Xu, Liangti Qu, Yongfeng Lu, Tianhong Cui

Department of Electrical and Computer Engineering: Faculty Publications

Raman spectroscopy plays a crucial role in biochemical analysis. Recently, superhydrophobic surface-enhanced Raman scattering (SERS) substrates have enhanced detection limits by concentrating target molecules into small areas. However, due to the wet transition phenomenon, further reduction of the droplet contact area is prevented, and the detection limit is restricted. This paper proposes a simple method involving femtosecond laser-induced forward transfer for preparing a hybrid superhydrophilic–superhydrophobic SERS (HS-SERS) substrate by introducing a superhydrophilic pattern to promote the target molecules to concentrate on it for ultratrace detection. Furthermore, the HS-SERS substrate is heated to promote a smaller concentrated area. The water vapor …

Advanced Mathematical And Numerical Methods In Control And Optimization For Smart Grids, Zhan Shu, Michael Z.Q. Chen, Qing Hui

Department of Electrical and Computer Engineering: Faculty Publications

While renewable energy, as a part of smart-grid technologies, brings clean energy, it also brings a series of power quality problems. An increasing number of power electronic devices and new smart-grid technologies are used to ensure a safe, reliable, and high-quality operation of the power grid. However, the effectiveness of these control devices and technologies largely depends on the accuracy of the model, the advancement of control methods, and the numerical optimization of the parameters.

This special issue focuses on recent advances in modeling, numerical analysis, control, and optimization of smart grids with some special emphasis on the mathematical problems …

Bibliometric Survey On Incremental Clustering Algorithms, Archana Chaudhari, Rahul Raghvendra Joshi, Preeti Mulay, Ketan Kotecha, Parag Kulkarni

Library Philosophy and Practice (e-journal)

For clustering accuracy, on influx of data, the parameter-free incremental clustering research is essential. The sole purpose of this bibliometric analysis is to understand the reach and utility of incremental clustering algorithms. This paper shows incremental clustering for time series dataset was first explored in 2000 and continued thereafter till date. This Bibliometric analysis is done using Scopus, Google Scholar, Research Gate, and the tools like Gephi, Table2Net, and GPS Visualizer etc. The survey revealed that maximum publications of incremental clustering algorithms are from conference and journals, affiliated to Computer Science, Chinese lead publications followed by India then United States. …

Multi-Agent Control System And Method, Piyush Grover, Karthik Elamvazhuthi

Department of Mechanical and Materials Engineering: Faculty Publications

Motion of multiple agents with identical non - linear dynamics is controlled to change density of the agents from the initial to the final density . A first control problem is formulated for optimizing a control cost of changing density of the agents from the initial density to the final density subject to dynamics of the agents in a density space . The first control problem , which is a non - linear non - convex problem over a multi - agent control and a density of the agents , is trans formed into a second control problem over the …