Engineering Commons^™

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

No abstract provided.

Activity Recognition Based On Thermopile Imaging Array Sensors, Qingshan Liang

Dissertations and Theses @ UNI

With aging population, the importance of caring for elderly people is getting more and more attention. In this paper, a low resolution thermopile array sensor is used to develop an activity recognition system for elderly people. The sensor is composed of a 32x32 thermopile array with the corresponding 33° × 33° field of view. The outputs of the sensor are sequential images in which each pixel contains a temperature value. According to the thermopile images, the activity recognition system first determines whether the target is within the tracking area; if the target is within the tracking area, the location of …

Investigating The Production Of Cores By Using Reclaimed Foundry Green Sand, Kristopher Lee Boss

Dissertations and Theses @ UNI

Increasing environmental regulations, transportation cost, delivery interruptions leading to production concerns, disposal cost, and demand from other industries have influenced the way foundry’s view used sand. The purpose of this research was to determine a beneficial reuse of overflow-green sand that would normally be disposed. The reclamation process used is a combination of mechanical and wet reclamation. The focus was on the production of foundry cold box cores and if using this reclamation process could create a core with a similar quality performance compared to new sand. Research in reclamation could pave the way for a closed loop sand system, …

The Effect Of Cutting Condition Selection On Tool Life In Sand Milling, Craig Ertl

Dissertations and Theses @ UNI

This study was completed to address the problem of determining what effect selected cutting conditions have on tool wear and tool life in robotic sand milling (RSM) operations. The purpose of this study was to analyze the tool wear mechanisms and characteristics that govern the RSM process. The purpose was also to establish an experimental methodology that may be used in future studies to assess tool life when examining various tooling materials and designs, as well as additional sand workpiece materials. Completing this research allowed the machining process to be optimized by analyzing differences in tooling cost with variable values …

3d Printing Technology On Spare Parts Business Supply Chain Management: A Case Study In Appliance Industry, Salih Boysan

Dissertations and Theses @ UNI

This study investigates the effects of using Additive Manufacturing (AM), also known as 3D printing, to produce spare parts within the supply chain of an appliance manufacturing company.

This research is based on an analysis of the operation of a spare parts business of an appliance manufacturing company. This research study used real data to investigate the feasibility of using 3D printing to reduce complexity in the spare parts division in terms of supplier rationalization, inventory reduction, and total cost of ownership. The research method used two scenarios: one where manufacturing spare parts traditionally was the baseline model and the …

How Quality Management Has Been Impacted In The Face Of Covid-19, Eldina Siljkovic

Dissertations and Theses @ UNI

The Coronavirus pandemic has impacted many facets of the United States. This study focuses on its magnitude in comparison to prior pandemics such as Anthrax, SARS, and Ebola. In addition to this comparison its impact on Quality Management within the agricultural sector and food supply chain was also assessed. The results of these studies showcase that COVID-19 has grown exponentially in comparison to prior pandemics and will continue to do so as we enter the winter season. Agricultural equipment manufacturing companies saw a drastic decline in quarterly revenues within 2020 in comparison to 2019. Millions in net sales were lost …

An Investigation Of Solar Panel Thermal Images Collected From An Unmanned Aerial Vehicle, Ginger Ivy Jo L'Heureux

Dissertations and Theses @ UNI

As the population of the world continues to increase, so does energy consumption. At the same time, available fossil fuels continue to be depleted. Knowing these two facts, there is a need to find additional sources of energy. Photovoltaic panels (solar panels) are front and center of the renewable energy available options.

Exploring the practical use of infrared thermal imaging for data collection and maintenance of photovoltaic panels is the main objective of this study. In this research, three unmanned aerial vehicle (UAV) flights were completed to obtain thermal imaging of the Cedar Falls Utilities Solar Field with various dates …

Impact Of Parent Mentoring And Participation In First Robotics On Middle And High School Age Female Perceptions Of Engineering Careers, Kirsten Olson

Dissertations and Theses @ UNI

Female presence within engineering careers has been a growing concern for decades, as females continue to major in engineering at a far lesser rate than males. Females may be affected by many different environmental factors, from parental influence, early engineering experiences, negative stereotypes present in male dominated careers, and male dominant culture in content classes and the workplace. Researchers have explored ways in which the gender gap within engineering can be closed, such as heightening females’ self-efficacy and providing early STEM experiences. Early engineering experiences include the FIRST (For Inspiration and Recognition of Science and Technology) Programs, where students are …

An Investigation Into The Prediction Of Double-Skin Penetration Within Chromite Molds And Cores In Heavy Section Steel Casting Using Process Simulation Software, Nathaniel Bryant

Dissertations and Theses @ UNI

This investigation was conducted in response to a commercial steel foundry approaching the University of Northern Iowa for assistance with a recurring defect they experienced on a production casting. The defect was described as a mass of metal that penetrated and consumed the interstices of their chromite molds and cores, and it was determined to consist of fayalite. After an extensive literature review, it was concluded that the foundry experienced the double-skin defect, a niche quality issue that most commonly occurs in heavy-section steel casting with chromite molding materials

After it was determined that the double-skin defect was occurring, a …

3d Printed Relief Valve Analysis And Validation, John Anthony Dutcher Iii

Dissertations and Theses @ UNI

Additive Manufacturing allows for faster, lower cost product development including customization, print at point of use, and low cost per volume produced. This research uses Stereolithography produced prototypes to develop an improvement to an existing product, the internal pressure relief valve of a positive displacement pump. Four 3D printed prototype assemblies were developed and tested in this research. The relief valve assemblies consisted of additive manufacturing produced pressure vessel components, post processed, and installed on the positive displacement pump with no additional machining. Prototype designs were analyzed with Computational Fluid Dynamic simulation to increase flow through the valve. The simulation …

Sand Distribution Effect On Three Dimensional Printed Sand Properties, Kip Woods

Dissertations and Theses @ UNI

The purpose of this study was to assess the performance characteristics of commercially available round grain silica sand for the use in three-dimensional sand printers. Two different average diameters were selected to examine the effects of screen distribution on printing performance; these diameters were 57-grain fineness number (GFN) and 70 GFN. These sands were a high purity round grain silica and had low trace contaminates, to reduce any possible influence from contaminates.

The resin system utilized in this investigation was a commercially available Furan resin system. Two test specimens were used in this study the American Foundry Society (AFS) tensile …

Voltage Regulation Of Unbalanced Distribution Network With Distributed Generators Through Genetic Algorithm, Islam Ali

Dissertations and Theses @ UNI

Energy demand has rapidly increased since the manufacturing revolution in the 19th century. One of the higher energy demands is electricity. The great majority of devices in the manufacturing field run on electricity. The vertically integrated grid paradigm has to be changed to supply the increase in the electrical demand residentially and commercially. Distributed generators (DG) such as Photovoltic (PV) is used to supply the increase in the electrical demand. Photovoltaic (PV) is one of the fast growing distributed generators (DG) as a renewable energy source. However, installing many PV systems to the distribution system can cause power quality problems …

Smartphone Based Ubiquitous Sensing Platform Leveraging Audio Jack For Power And Communication, Ranjana Joshi

Dissertations and Theses @ UNI

With the popularization of smartphones, various smartphone centric ubiquitous sensing applications, which use a smartphone in conjunction with external sensors for data acquisition, processing, display, communication, and storage, have emerged. Because smartphones do not have a universal data interfaces, many ubiquitous sensing applications use the earphone and the microphone channels of the 3.5mm audio interface for data communications so that they can work with various types of smartphones. The earphone channels of the 3.5mm audio interface can only send AC signal out of a smartphone, hence DC power needs to be harvested from the earphone channels.

In this research, based …

An Experimental Study Of Non-Metallic Inclusions Precipitation And Its Effect On Impact Toughness Variations In Low Alloy Steel Subjected To Complex Deoxidation, Pavel Bizyukov

Dissertations and Theses @ UNI

A low level of non-metallic inclusions in steel is the key requirement in the concept of clean steel. Although the concept has received its name quite recently, it has been implemented at the large-scale steel mills for more than 40 years. Production of clean steel became possible due active development and adoption of the post-melting treatment of molten metal in the teeming ladle. Ladle metallurgy, an umbrella term for various methods of treatment, includes operations that cannot be performed during primary metallurgical processes such as melting in an electric arc, basic oxygen, or air induction furnace. Initially, the most common …

Corn Stover Biochar In Gypsum Board: Empirical Analysis Of Thermal Conductivity And Flexural Strength, Albena Yordanova

Dissertations and Theses @ UNI

Gypsum board, an economical and durable finish material for wall and ceiling construction in the United States and worldwide, is the component with the lowest thermal performance in a typical exterior wall assembly. It also constitutes a substantial portion of construction waste in landfills, potentially creating harmful environmental effects and dangerous gases. To minimize the negative effects of fast growing construction waste of gypsum in landfills and meet higher standards for energy efficiency in construction, there is a need to explore sustainable ways of improving thermal properties of gypsum board and recycling the material. Gypsum can be recycled and used …

Development Of A Hydraulic Component Leakage Detecting System Using Pressure Decay Signal, Xuanju Shang

Dissertations and Theses @ UNI

It is preferable to detect leakage at the earliest phase in the manufacturing process, and then further assembly of hydraulic components with leakage problems can be avoided. Integrating a USB based microcontroller and a pressure sensor; this study developed a hydraulic leakage detection system in using air instead of hydraulic oil as medium, through measuring pressure decay signals captured by a real time data acquisition system. Compared with the conventional hydraulic system using oils, this system shows advantages in safety operation and little environmental concerns due to use a lower pressure clean air.

The low-cost hydraulic leakage detection system was …

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

An Enhanced Pulse Position Modulation (Ppm) In Ultra-Wideband (Uwb) Systems, Lingxiu Chen

Dissertations and Theses @ UNI

Simplicity, transmission rate, and bit error rate (BER) performance are three major concerns for ultra-wideband (UWB) systems. The main advantage of existing pulse-position modulation (PPM) schemes is simplicity, but their BER performance is poorer than that of an on-off-keying (OOK) modulation scheme, and their transmission rate is lower than that of an OOK scheme. In this research project, I will explore a novel PPM scheme, which can maintain the simplicity of the PPM schemes as well as achieve a BER performance and a transmission rate similar to the OOK scheme. During the research, I will thoroughly investigate the relationship between …

The Environmental Performance Of Biobased Resin Within Phenolic-Urethane Nobake Binders: A Feasibility Study, Ian David Morgan Williams

Dissertations and Theses @ UNI

The objectives of this research were to investigate the discovery and development of a biobased nobake binder resin for use within the foundry industry toward improved energy efficiency and environmental performance. The performance of polysaccharides within biobased resins was evaluated using industry-accepted methods and standards such as cure rate, tensile-strength development, and casting performance based upon step cone core results. Biobased nobake resins comprised of polysaccharide raw materials cure at a rate that is comparable to conventional nobake sand binders. Upon reaching stripping time, the development of biobased resin reveals a rapid increase in tensile strength, reaching 80% of its …

A Clustering Based Matrix For Selecting Optimal Tools And Techniques In Quality Management, Hassan A. Alsultan

Dissertations and Theses @ UNI

The purpose of this research was to explore a systematic pattern for selecting quality tools and techniques in the manufacturing and service industries. This study asked, “What are the best DMAIC tools and techniques concerning circumstances of quality dimensions of products and services?” To answer this question, this research developed innovative, diagnostic matrices by mimicking the contradiction matrix of the Theory of Inventive Problem Solving (TRIZ). These innovative matrices are intended to help non-expert users to select the best sets of quality tools and techniques for solving different quality problems. By conducting a cluster analysis, the researcher uncovered homogeneous patterns …

An Analysis Of Use Of Automated Tools For Improving The Process Of Software Verification And Validation In A Midwestern Company, Darshak Dodiya

Dissertations and Theses @ UNI

As the use of electronics and software in the modern off road vehicles tend to increase, there is a huge challenge of getting the electronics and software tested before making it available for customer use. There are a lot of interactions between the hardware and software for the vehicle to function. And with the amount of interactions in the hardware and software come a lot of problems in verifying the functionality of the vehicle. If proper verification is neglected, the customer might end up getting an unsafe vehicle which can lead to serious consequences. To make these vehicles safe and …

An Investigation On How Operational Wind Turbines Are Used In Secondary Classrooms, James Smith

Dissertations and Theses @ UNI

Through a review of literature, it was found that many schools in the United States are installing operational wind turbines, but it was unclear how teachers were using them in their science, technology, engineering and mathematics (STEM) classrooms. In order to identify how these operational wind turbines were being used and to create a list of expectations for schools with operational wind turbines, this exploratory study surveyed STEM teachers from all across the United States. A stratified random sample was created using a U.S. Department of Energy database of schools with operational wind turbines. Administrators from the selected schools identified …

Analysis Of Wind Power Generation With Application Of Wind Tunnel Attachment, Ulan Dakeev

Dissertations and Theses @ UNI

This study presents an empirical method for developing a new approach in which a wind tunnel apparatus is used to improve the efficiency of power output by a small-scale wind turbine. A custom-designed wind tunnel attachment was constructed to record, analyze, and interpret both incoming and outgoing wind velocity readings. Moreover, the dissertation project addresses a significant issue concerning the power generation of an experimental wind turbine while the wind tunnel is attached. Wind power characteristics that indicate power output versus wind velocity were obtained by performing a number of case studies. The case studies included normal operation of the …

Designing Elementary Engineering Education From The Perspective Of The Child, Beth Dykstra Van Meeteren

Dissertations and Theses @ UNI

Many concerned leaders of industry and government believe the ability to sustain our quality of life and address the grand challenges of our times is contingent upon the successful engagement of our younger children in science, technology, engineering, and mathematics (STEM). What STEM curricula, specifically engineering curricula, should address, how the curriculum should be delivered, and how the children construct an understanding of engineering are still unanswered questions. Engineering curriculum is beginning to emerge for elementary students, but does more to teach children about engineering than allowing them to develop engineering habits of mind.

This qualitative study used constant comparative …

Ergonomics Evaluation Of Task Demands Among Kitchen Staff, Jaqueline Pereira Da Silva

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the workplace demands faced by a group of kitchen staff at six dining centers and to survey musculoskeletal complaints among this sample of workers. The dining centers were located in six different public elementary and middle schools in a city in the south of Brazil. This research was developed following qualitative research design, and the researcher made use of the “Activity Oriented Ergonomics (AOE) methodology.

The AOE focuses on the work analysis that evaluates real work situations that allows a reassessment of work demands. In this case the chosen methodology was a …

Limited Assessment Of A Selected Particulate Matter Sensor Technology In Emission Measurement Applications On Diesel Vehicles, Svetlana Korotkova Espinosa

Dissertations and Theses @ UNI

The study assessed the ability of a novel particle sensor to provide adequate evaluation of real-time emissions from modem diesel engines and estimate the effectiveness of emission control devices. Emission data were obtained from vehicles in real-world field conditions under various test cycles. The datasets were used to determine whether there is an association between particulate matter (PM) measurements produced by particle sensor and the PM measurements from reference instrument. Exploratory analysis was combined with statistical techniques to investigate suitability of particle sensor to adequately measure PM mass concentrations in exhaust gases of modem diesel vehicles. Results of the study …

An Investigation On In-Process Spc Sampling Frequency For Shaft Bearing Turning Process, Jiaxu Chu

Dissertations and Theses @ UNI

The machining processes have the uniqueness of discrete production and flexible scheduling as cellular manufacturing design. To ensure the quality of machining products, control charts for Statistical Process Control (SPC) has been implemented in the company to monitor the machining process. Sampling is an essential part of data collection for SPC control charts and sampling should be done for machining processes becomes an issue in the company.

This study focused on the investigation of SPC sampling frequencies for shaft bearing turning process using the technique of Average Production Length (APL). The purpose of the study was to identify the SPC …

The Integration Of Wind Energy In The Electrical Grid During The Contingencies, Islam Ali

Dissertations and Theses @ UNI

As wind energy expansion develops, there are also many problems and challenges to connect the wind farms to the grid. There are many different interactions during the connection like the voltage flicker, harmonics, transient, short circuit current, frequency, and safety protection. Those problems may affect the performance of the grid and may cause serious problems. This study investigates the grid-connection problems for the wind turbines and offers appropriate solutions. This study provides a simulation for the power system during the faults. The electrical grid in the simulation contains generators and wind turbines which are connected to the grid. It also …

Modeling And Analysis Of Grid-Connected Solar-Wind Hybrid Power System, Sultan Altamimi

Dissertations and Theses @ UNI

Renewable energies are considered to be a significant part of the energy mix to assist the existing electricity demand and the future of electrical generation. Electrical power simulation software is increasingly being used to answer and determine the source of potential problems in the actual power system. To have a better understanding of an electrical power system, it is essential to validate all the components through simulation within an environment that allows accurate modeling of all power system components. This research presents modeling and analysis of an actual grid-connected solar-wind hybrid system at University of Northern Iowa campus in Cedar …

A Sociable Humanoid Autonomous Robotic Platform (The Sharp Project): An Evaluation Of The G.E.N.E.S.I.S. Robot As An Interactive Consumer Robotic Platform, Jeffrey J. Rick

Dissertations and Theses @ UNI

The Social Humanoid Autonomous Robotic Platform (SHARP) project is an android project that was created with the intent of making learning about androids and robotics easier for the novice, diverse for the expert, educational in the classroom, and useful in the home or business. The project centers itself on its simplicity, low cost, and expandability. This paper illustrates how the SHARP Project has the potential to be an affordable fit in nearly every modern setting. The introduction of the SHARP project lays the groundwork for people of many ages, incomes, and educational levels to take advantage of robotics technology. The …