Engineering Commons^™

Increasing The Dissolution Rate Of Polystyrene Waste In Solvent-Based Recycling, Rita Kol, Ruben Denolf, Gwendoline Bernaert, Dave Manhaeghe, Ezra Bar Ziv, George W. Huber, Norbert Niessner, Michiel Verswyvel, Angeliki Lemonidou, Dimitris S. Achilias, Steven De Meester

Michigan Tech Publications, Part 2

Solvent-based recycling of plastic waste is a promising approach for cleaning polymer chains without breaking them. However, the time required to actually dissolve the polymer in a lab environment can take hours. Different factors play a role in polymer dissolution, including temperature, turbulence, and solvent properties. This work provides insights into bottlenecks and opportunities to increase the dissolution rate of polystyrene in solvents. The paper starts with a broad solvent screening in which the dissolution times are compared. Based on the experimental results, a multiple regression model is constructed, which shows that within several solvent properties, the viscosity of the …

On Confidence And Sense Of Belonging In Cybersecurity Students: Analysis & Prediction, Sadaf Amna Sarwari

Graduate Theses, Dissertations, and Problem Reports

In recent years, there has been a rapid expansion of cybersecurity programs across higher education institutions in response to the widening skills gap in the cybersecurity job market. This study adopts quantitative and qualitative approaches to identify factors influencing West Virginia University (WVU)’s LANE Department of Computer Science and Electrical Engineering (LCSEE) students’ confidence and sense of belonging in the cybersecurity field. The results are based on data collected from surveys administered to LCSEE students in April 2022 and April 2023. The responses were analyzed using descriptive & inferential statistics and logistic regression techniques. Additionally, the 2023 data was utilized …

Condition Assessment Of Reinforced Concrete Sanitary Sewer Pipelines Using Probabilistic Methods And Advanced Inspection Tools, Moein Ebrahimi

Civil Engineering Dissertations

Large sanitary sewer pipelines (SSPs) are the backbone of modern infrastructure. They carry wastewater from smaller lines to treatment plans; therefore, they are critical for public health and safety. According to the ASCE report card published in 2021, the condition rate of sanitary sewage networks in the United States is D+ (i.e., poor) (ASCE 2021). Therefore, frequent inspections of SSPs are crucial for performing a proper life cycle management strategy. New inspection technologies such as LiDAR have recently been employed for rapid condition assessment of SSPs. Because of the precision of LiDAR inspection data, it can not only measure hydraulic …

Experimental Study On Proportioning Of Ultra-High Strength Similar Materials For Large Similarity Ratio Model Tests, Zhan Xinyu, Gao Lin, Zhao Fanghao, Wang Yongyin, Liu Ping, Han Sen

Coal Geology & Exploration

Similar simulation of physical material is a common research method in the field of geotechnical engineering. Selecting appropriate similar materials and determining their proportions is the key to successfully simulating the prototype project. Existing similar materials are mostly developed for similar simulation with small geometric similarity ratio (1∶250-1∶25). These materials generally have low strength (0.2-7.6 MPa), making it difficult to meet the requirements of large similarity ratio model. Therefore, in order to prepare an ultra-high strength similar material with a strength of more than 10 MPa suitable for large similarity ratio model, river sand, barite, gypsum, and cement with different …

Critical Buckling Coefficient Of Tapered Web Plate Girder Under Compression And Bending Stresses, Saad A. Yehia, Ramy I. Shahin

Mansoura Engineering Journal

The tapered girders were developed as a cost-effective solution to the problem of long-span building construction. These systems are very attractive from an economic viewpoint, combining wide spans, quick erection, and easy access to services between the shallow parts of the beam and the ceiling below. Elastic-local buckling is one of several modes of failure that must be considered during the structure design. Although elastic-local buckling has been studied for decades, there is still a need to develop quick and comprehensive procedures that will reduce product design time, particularly during the pre-sizing stage. Most design codes have no specific provisions …

Dual-Site Photoplethysmography Sensing For Noninvasive Continuous-Time Blood Pressure Monitoring Using Artificial Neural Network, Anas Mohmmad Rabab’Ah

Theses

Millions of people worldwide struggle from high blood pressure, often known as hypertension, and it is a major health concern that can lead to serious cardiovascular diseases, including heart attacks and many other consequences. Blood pressure monitoring that is reliable and accurate is crucial to the detection and management of hypertension. Although invasive techniques, such as arterial catheterization, are considered to be the most accurate means of evaluating blood pressure, they can be painful, time-consuming and carry a risk of complications.
This thesis presents the development of a real time non-invasive blood pressure monitoring system based on commercially available microcontroller …

Evaluation Of A First Flush System With Multiple In-Line Bypassing Fuel Separator Components In The Industrial Area Of An Airport, Kazi Rashid

Civil Engineering Dissertations

ABSTRACT: This dissertation explores the effectiveness of a complex system employed to capture the first flush (FF) generated from industrial activities occurring at an airport. The First Flush System (FFS) utilized by the DFW International Airport is comprised of multiple in-line bypassing fuel separators and located in many parts of the Air Operations Area (AoA) of the airport as well as maintenance areas. The system collects and conveys a portion of the rainfall runoff generated from the drainage areas of the industrial land-use portion of the DFW airport to a Stormwater Pre-treatment Plant (SWPTP) and then to Trinity River Authority …

Preconstruction Support Cost Hours Estimating On Caltrans Pavement Rehabilitation Projects, Nigel Blampied, Tariq Shehab, Elhami Nasr, Laxmi Sindhu Samudrala

Mineta Transportation Institute

Because the construction phase accounts for the majority of project costs for pavement rehabilitation projects, most research on infrastructure project cost estimating focuses on that phase, rather than on the preconstruction phases. Nevertheless, costs incurred prior to construction, referred to in this report as "preconstruction costs" are significant and worthy of consideration (See Section 2.1 of the report for a more detailed and precise definition of preconstruction). In the 20202021 fiscal year, for instance, the California Department of Transportation (Caltrans) spent more than $169 million on preconstruction work for pavement rehabilitation projects. This report presents the results of a study …

Multivariate Regression And Variance In Concrete Curing Methods: Strength Prediction With Experiments, Haiyan Sally Xie, Sai Ram Gandla, Owen Shi, Pranshoo Solanki

Faculty Publications – Technology

Because concrete strengths and quality are affected by various factors, multivariate regression models are often used to analyze the differences between predicted and target outputs. However, the variableness of a predicted output and how individual input parameters affect prediction reliabilities are still uncertain in practical applications, especially for the prediction of compressive strengths of concrete. This study aims to develop multivariate models for predicting concrete strengths and providing the variance analysis of prediction results by comparisons with experiment outcomes. First, this paper provides an in-depth examination of established variance analysis methods in the context of commonly used multivariate regression models. …

Exploring The Spatially Heterogeneous Effects Of The Built Environment On Bike-Sharing Usage During The Covid-19 Pandemic, Hongtai Yang, Zishuo Guo, Guocong Zhai, Linchuan Yang, Jinghai Huo

Civil & Environmental Engineering Faculty Publications

Bike-sharing holds promise for available and healthy mobility services during COVID-19 where bike sharing users can make trips with lower health concerns due to social distancing compared to the restricted transportation modes such as public transit and ridesharing services. Leveraging the trip data of the Divvy bike-sharing system in Chicago, this study explores spatially heterogeneous effects of built environment on bike-sharing usage under the pandemic. Results show that the average weekly ridership declined by 52.04%. To account for the spatially heterogeneous relationship between the built environment and the ridership, the geographically weighted regression (GWR) model and the semiparametric GWR (S-GWR) …

Impact Of New Generation Wide-Base Tires On Fuel Consumption, Izak M. Said, Egemen Okte, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

This study combined multiple approaches to evaluate the structural and economic impact of using new-generation wide-base tires (NG-WBT) in New Brunswick, Canada. A three-dimensional finite-element model of a typical pavement structure used in New Brunswick was used to predict critical pavement responses. The model includes measured tire-pavement contact forces among other variables overlooked in conventional flexible pavement analysis approaches. Using the model output, regression analysis was performed to predict the responses under various loadings to avoid performing the time-consuming finite-element analysis. Eight-year weight-in-motion data and critical pavement responses were used in transfer functions to predict pavement damage and the corresponding …

Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer

Theses and Dissertations

America's General Aviation sector has witnessed significant demographic shifts since the turn of the century. The number of certified, private pilots, non-fatal aircraft accidents, fatal aircraft accidents, and number of general aviation hours flown are all in decline. Meanwhile, the average age of an American private pilot has increased by several years. All of these factors indicate that the industry is in decline. This study determined via mathematical, linear regression that times relationship to the number of annual, fatal General Aviation accidents and the number of certified private pilots is negative. It also proved that the average age of the …

An Exercise Device Used To Achieve Bone Formation Metrics For The Strengthening Of The Proximal Femur., Sean P. Coyle

Electronic Theses and Dissertations

Lateral falls often lead to hip fracture particularly in the elderly who have low bone mineral density. These fractures frequently lead to indirect mortality soon after injury. Normal use over the course over a lifetime leads to optimized adaptation of the bone in the proximal femur according to normal loading. A lateral fall generates non-normal, lateral loading at the proximal hip where the bone has not adapted to withstand such loading. The resulting fracture is generated by reversed strains on the bone tissue in the femoral neck in the hip in contrast to vertical, quotidian loading. Modern practices for preventing …

Delineating The Relationship Between Cardiovascular Physiology And Subject Characteristics Using Computational Modeling And Systemic Review, Aseem Pradhan

All Theses

Lumped Parameter Networks (LPN) are computational models that can capture the systemic responses of the cardiovascular system. An LPN describes the systemic behavior by providing outputs such as the blood pressure, flowrate, and heart chamber volume at the points defined in the network. To use the LPN for medical applications, it needs to provide output values that represent the physiology of realistic subjects. The cardiovascular system exhibits short-term and long-term adaptations to factors such as aging, weight gain, exercise, etc. Therefore, subject characteristics such as age, height, weight, etc. affect the output values of the LPN. Current literature reports the …

Predictive Models For Pulmonary Artery Size In Fontan Patients, Akash Gupta, Chris Gillett, Patrick Gerard, Michael M.H. Cheung, Jonathan P. Mynard, Ethan Kung

Publications

We developed models of pulmonary artery (PA) size in Fontan patients as a function of age and body surface area (BSA) using linear regression and breakpoint analyses based on data from 43 Fontan patients divided into two groups: the extracardiac conduit (ECC) group (n = 24) and the non-ECC group (n = 19). Model predictions were compared against those of a non-Fontan control group (n = 18) and published literature. We observed strong positive correlations of the mean PA diameter with BSA (r = 0.9, p < 0.05) and age (r = 0.88, p < 0.05) in the ECC group. The absolute percentage differences between our BSA and age model predictions against published literature were less than 16% and 20%, respectively. Predicted PA size for Fontan patients was consistently smaller than the control group. These models may serve as useful references for clinicians and be utilized to construct 3D anatomic models that correspond to patient body size or age.

The Impact Of Design Changes In Construction Projects On The Cost Charged By Consultant Offices, Hadi Abou Chakra

BAU Journal - Science and Technology

In any construction project, a large number of modifications occur. The consequences of those modifications may result in additional costs due to the re-design of the project on each member of the project’s stakeholders. The financial impact of modifications during the construction phase of a project on consultant offices will be explored in this study. The aim of this study is to investigate the cost of the modifications and to examine the type of relationship between the time ‎spent on the design to accomplish the modifications and the amount of money earned in the return of the ‎extra work done. …

A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini

Electronic Theses and Dissertations

Wire arc additive manufacturing is a process of making three-dimensional metal parts in a layer-by-layer approach using a feed wire and electric arc as a heat source. Wire arc additive manufacturing (WAAM) is becoming more popular due to its ability to create complex 3D parts, less build time, high deposition rate, and significant cost savings. Out of the many parameters used in WAAM, one of the important parameters is shielding gas which plays a significant role in material quality, properties, and defects. In this study, a controlled amount of Argon (Ar) and Nitrogen (N₂) shielding gases are used …

Optimization And Modeling Of Process Parameters In Multi-Hole Simultaneous Drilling Using Taguchi Method And Fuzzy Logic Approach, Muhammad Aamir, Shanshan Tu, Majid Tolouei-Rad, Khaled Giasin, Ana Vafadar

Research outputs 2014 to 2021

In industries such as aerospace and automotive, drilling many holes is commonly required to assemble different structures where machined holes need to comply with tight geometric tolerances. Multi-spindle drilling using a poly-drill head is an industrial hole-making approach that allows drilling several holes simultaneously. Optimizing process parameters also improves machining processes. This work focuses on the optimization of drilling parameters and two drilling processes-namely, one-shot drilling and multi-hole drilling-using the Taguchi method. Analysis of variance and regression analysis was implemented to indicate the significance of drilling parameters and their impact on the measured responses i.e., surface roughness and hole size. …

Invariant-Based Online Software Anomaly Detection And Selective Regression Testing, Yizhen Chen

Legacy Theses & Dissertations (2009 - 2024)

Software has been extensively used in various domains to provide online services. With the growing popularity of these types of applications, the quality of the software has a great impact on many of our daily activities [1]. Reliable software executions that deliver expected outcomes are essential for quality services. Software is considered abnormal when its behavior deviates from what is expected at any point during its execution. When anomalous behavior propagates to an exit point of the software and produces an incorrect output or an unexpected termination of the execution, it is considered a software failure. An anomaly may or …

Integrated Topic Modeling And Sentiment Analysis: A Review Rating Prediction Approach For Recommender Systems, Anbazhagan Mahadevan, Michael Arock

Turkish Journal of Electrical Engineering and Computer Sciences

Recommender systems (RSs) are running behind E-commerce websites to recommend items that are likely to be bought by users. Most of the existing RSs are relying on mere star ratings while making recommendations. However, ratings alone cannot help RSs make accurate recommendations, as they cannot properly capture sentiments expressed towards various aspects of the items. The other rich and expressive source of information available that can help make accurate recommendations is user reviews. Because of their voluminous nature, reviews lead to the information overloading problem. Hence, drawing out the user opinion from reviews is a decisive job. Therefore, this paper …

Measuring Risks Of Interdependencies In Enterprise Systems: An Application To Ghana’S Salt Enterprise, Yaw Mensah

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation describes the use of Functional Dependency Network Analysis (FDNA) for modeling risks resulting from dependencies among elements of enterprise systems with application to salt processing enterprise in Ghana. FDNA was developed to model dependencies among members of enterprise systems by highlighting two dimensions of dependency: strength and criticality. Nonetheless, the concepts and analytics for these two dimensions of dependencies needed further development and generalization in the context of project management and systems development in developing countries.

Managing risks within the interdependency in enterprise systems through integration will help improve global economic growth. Coherent theory for enterprise integration must …

Analysis And Optimization For Combat Capability Based On Sequential Simulation Experiment, Chenyan Kong, Zhu Jing, Jiao Song, Shaojie Mao

Journal of System Simulation

Abstract: To deal with the optimization of combat capability, the sequential simulation experiment method was proposed. The simulation evaluation method with precision constraint was used to control the simulation running times. The sensitivity analysis experiment was carried out to identify the important factors affecting the combat capability. The relation model between the important factors and combat capability was constructed via regression analysis experiment. To get the combat capability improvement as large as possible with the price as small as possible, the optimization was used. In the application example, the air-defense combat capability was improved by the method.

Post-Disaster Construction Labor Cost Fluctuations: Measurement And Modeling, Navid Ahmadi Esfahani

Civil Engineering Dissertations

The United States has been one of the top five countries most frequently hit by natural disasters. The post-disaster survival of cities and communities depend on their capabilities to reconstruct and repair damages to buildings and other infrastructure systems. The significant increase in the repair costs following large-scale natural disasters, also called “demand surge,” slows down the repair process that impacts many lives touched by large-scale natural disasters. Previous studies showed that post-disaster construction labor cost escalation drives the total post-disaster construction cost escalation in the U.S. The ultimate goal of this research is to (1) measure post-disaster construction labor …

A Simple Method Of Coil Design, M. Rawlik, A. Eggenberger, J. Krempel, Christopher Crawford, K. Kirch, F. M. Piegsa, G. Quéméner

Physics and Astronomy Faculty Publications

In this article, we present a method to design a coil producing an arbitrarily shaped magnetic field by restricting the path of the coil's wires to a regular grid. The solution is then found by a simple least squares minimum. We discuss practical applications, in particular, in the active magnetic field stabilization system of the neutron electric dipole moment experiment at the Paul Scherrer Institute in Villigen, Switzerland. We also publish the software implementation of the method.

Analysis Of Temperature And Humidity Effects On Horizontal Photovoltaic Panels, Corey J. Booker

Theses and Dissertations

The United States Air Force seeks to address power grid vulnerability and bolster energy resilience through the use of renewable energy sources. Air Force Institute of Technology engineers designed and manufactured control systems to monitor power production from the most widely-used silicon-based solar cells at 38 testing locations around the globe spanning the majority of climate types. Researchers conducted multivariate regression analysis to establish a statistical relationship between photovoltaic power output, ambient temperature, and humidity pertaining to monocrystalline and polycrystalline photovoltaic panels. Formulated models first characterized power output globally, then by specific climate type with general inaccuracy. Location-specific models are …

Day Laborers & Extreme Heat: Recommendations For Reducing Heat Stress, Sandra Mena

REU Final Reports

The Intergovernmental Panel on Climate Change (IPCC) has various Global Climate Models (GCM). One of them, models three greenhouse gases. The increasing amount of greenhouse gases are just a fraction of factors that fuel global climate change. According to the IPCC 2014, climate related extremes such as heatwaves are likely to occur more regularly and are likely to increase in duration. Since 1979, there has been over 9000 deaths that occurred from heat-related incidents in the United States (U.S. Environmental Protection Agency, 2016). Which brings attention to population groups who are exposed to hot temperatures on a frequent basis due …

Predicting General Aviation Pilots’ Weather-Related Performance Through A Scenario-Based Assessment, Jessica Cruit, Christina Frederick, Beth Blickensderfer, Joseph Keebler, Thomas Guinn

Publications

Weather-related accidents continue to challenge the general aviation (GA) community and with the development of advanced weather technology, GA pilots need additional education and training on how to effectively use these weather products to ensure flight safety. Currently, the literature on aviation weather suggests that there is a gap in both training and assessment strategy for GA pilots. Furthermore, several studies advocate assessing GA pilots at a deeper level of learning by including weather-based, scenario/application questions on the Federal Aviation Administration’s (FAA) written exam for private pilots. After first developing a scenario-based, aviation weather assessment, we used a multiple regression …

Prediction Of Remaining Life Of Power Transformers Based On Left Truncated And Right Censored Lifetime Data, Yili Hong, William Q. Meeker, James D. Mccalley

James McCalley

Prediction of the remaining life of high-voltage power transformers is an important issue for energy companies because of the need for planning maintenance and capital expenditures. Lifetime data for such transformers are complicated because transformer lifetimes can extend over many decades and transformer designs and manufacturing practices have evolved. We were asked to develop statistically-based predictions for the lifetimes of an energy company’s fleet of high-voltage transmission and distribution transformers. The company’s data records begin in 1980, providing information on installation and failure dates of transformers. Although the dataset contains many units that were installed before 1980, there is no …

Generalized Clusterwise Regression For Simultaneous Estimation Of Optimal Pavement Clusters And Performance Models, Mukesh Khadka

UNLV Theses, Dissertations, Professional Papers, and Capstones

The existing state-of-the-art approach of Clusterwise Regression (CR) to estimate pavement performance models (PPMs) pre-specifies explanatory variables without testing their significance; as an input, this approach requires the number of clusters for a given data set. Time-consuming ‘trial and error’ methods are required to determine the optimal number of clusters. A common objective function is the minimization of the total sum of squared errors (SSE). Given that SSE decreases monotonically as a function of the number of clusters, the optimal number of clusters with minimum SSE always is the total number of data points. Hence, the minimization of SSE is …

Application Of Morlet Wavelet In The Diagnosis Of Noise Signal Characteristics Of A Wind Turbine Blade In Abnormal Operation, Chao-Nan Wang, Yao-Chi Tang

Journal of Marine Science and Technology

This study developed an estimation model for noise signal characteristic diagnosis based on the time-frequency analysis technique. The time-frequency analysis theory uses the relatively mature and extensively used wavelet method as the basis of signal analysis, but wavelet analysis generates wavelet theories different from other mother wavelet methods. This study used the Morlet Transform, which is a type of wavelet transform using a mother wavelet for wavelet analysis of signals. The time axis was integrated according to the result of time-frequency analysis in order to obtain the marginal spectrum value of the frequency domain. Finally, statistical regression analysis was used …