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University of Northern Iowa

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Full-Text Articles in Engineering

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 Jan 2019

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 ...


An Investigation Of Solar Panel Thermal Images Collected From An Unmanned Aerial Vehicle, Ginger Ivy Jo L'Heureux Jan 2019

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 ...


Sand Distribution Effect On Three Dimensional Printed Sand Properties, Kip Woods Jan 2018

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 ...


A Graphical File System Visualization Tool For Operating Systems, Jacob Bundt Jan 2018

A Graphical File System Visualization Tool For Operating Systems, Jacob Bundt

Honors Program Theses

Fileshark was developed for the primary purpose of aiding in the teaching of students in file system related courses, particularly at the undergraduate level, by providing a visual representation of often abstract file system ideas. Many teachers find it difficult to teach the file system in detail in a typical operating systems classroom environment due to its abstract nature and the inability to truly observe what is occurring within the file system. Fileshark provides an easy to use interface that can be used by both students and professors to visualize the internal workings of the file system and the processes ...


Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch Jan 2018

Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch

Honors Program Theses

It is generally accepted that every violin has different tone quality in terms of intonation and the depth of the harmonics produced. The best violins are made by experienced luthiers that craft each with precision to produce the best possible tonal quality. The quality of the finished violin is dependent upon both the specific shape and the vibrational response of the wood used in its construction. Because the hard wood used in violin construction is inhomogeneous, the composition and structure of material used is critical to the final product.1 Luthiers would initially rely on their experience to feel the ...


3d Printed Relief Valve Analysis And Validation, John Anthony Dutcher Iii Jan 2018

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 ...


Voltage Regulation Of Unbalanced Distribution Network With Distributed Generators Through Genetic Algorithm, Islam Ali Jan 2018

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 ...


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 Jan 2017

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 ...


Magnetic Behavior Of Bulk And Nanostructured Mnxtas2, Lucas Paul Beving Jan 2017

Magnetic Behavior Of Bulk And Nanostructured Mnxtas2, Lucas Paul Beving

Honors Program Theses

At its base, material science research aims to categorize specific materials by their various attributes, such as structure, integrity, electronic properties, magnetic properties, and others. By categorizing materials in this way, it becomes easier to generalize the application of a specific material to those within a broader category. The interest in materials that exhibit useful characteristics at small scales derives directly from the technology industry’s need for smaller and smaller devices. Two-dimensional materials are of great interest for this reason.

Two-dimensional materials are comprised of many single layers, or planes, stacked together to create a crystal. Each layer may ...


Smartphone Based Ubiquitous Sensing Platform Leveraging Audio Jack For Power And Communication, Ranjana Joshi Jan 2017

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 ...


The Efficient Recovery Of Deleted Data From Nand Flash Memory, Lisa Diercks Jan 2016

The Efficient Recovery Of Deleted Data From Nand Flash Memory, Lisa Diercks

Honors Program Theses

NAND flash memory is used in flash drives, smart phones, and memory cards for digital cameras. While there are ways to recover data from deleted memory, there are no universal or efficient ways to recover data from NAND flash memory. When a user clicks “delete” on a file in this type of memory, the file is not necessarily deleted, but may just be hidden. This means these files are still on the chip, but are inaccessible through normal means. The ability to recover this lost data could help computer forensic examiners during investigations and corporations working to use secure deletion ...


Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner Jan 2015

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 ...


Development Of A Hydraulic Component Leakage Detecting System Using Pressure Decay Signal, Xuanju Shang Jan 2015

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 ...


An Analysis Of Use Of Automated Tools For Improving The Process Of Software Verification And Validation In A Midwestern Company, Darshak Dodiya Jan 2014

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 Enhanced Pulse Position Modulation (Ppm) In Ultra-Wideband (Uwb) Systems, Lingxiu Chen Jan 2014

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 ...


A Clustering Based Matrix For Selecting Optimal Tools And Techniques In Quality Management, Hassan A. Alsultan Jan 2014

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 ...


The Environmental Performance Of Biobased Resin Within Phenolic-Urethane Nobake Binders: A Feasibility Study, Ian David Morgan Williams Jan 2014

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 ...


Analysis Of Wind Power Generation With Application Of Wind Tunnel Attachment, Ulan Dakeev Jan 2013

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 ...


Development Of A Modular Dual Engine Hybrid Electric Vehicle Simulation Model, Kenan Baltaci Jan 2012

Development Of A Modular Dual Engine Hybrid Electric Vehicle Simulation Model, Kenan Baltaci

Dissertations and Theses @ UNI

Depleting resources of fossil fuel, climate change impacts, high oil prices, and strict emission requirements are leading to the research on efficient, environmentally friendly, and lowered fossil fuel dependent solutions in the transportation field. While a number of studies used computer modeling and simulation tools to investigate hybrid electric vehicles (HEVs), very few attempted to model and simulate a dual-engine hybrid vehicle. Designing a vehicle engine to meet energy needs in the fully loaded condition is not an optimal solution for manufacturers and customers. The larger the engine, the higher the manufacturing costs for companies, and higher fuel consumption for ...


Incorporating The Delphi Technique To Investigate Renewable Energy Technology Transfer In Saudi Arabia, Nasir K. Al-Otaibi Jan 2012

Incorporating The Delphi Technique To Investigate Renewable Energy Technology Transfer In Saudi Arabia, Nasir K. Al-Otaibi

Dissertations and Theses @ UNI

Saudi Arabia is a major oil-producing nation facing a rapidly-growing population, high unemployment, climate change, and the depletion of its natural resources, potentially including its oil supply. Technology transfer is regarded as a means to diversify countries' economies beyond their natural resources. This dissertation examined the opportunities and barriers to utilizing technology transfer successfully to build renewable energy resources in Saudi Arabia to diversify the economy beyond oil production. Examples of other developing countries that have successfully used technology transfer to transform their economies are explored, including Japan, Malayasia, and the United Arab Emirates. Brazil is presented as a detailed ...


The Design And Evaluation Of Wireless Sensor Networks For Applications In Industrial Locations, Hameed Madwar Jan 2012

The Design And Evaluation Of Wireless Sensor Networks For Applications In Industrial Locations, Hameed Madwar

Dissertations and Theses @ UNI

In manufacturing industries, there exist many applications where Wireless Sensor Networks (WSN's) are integrated to provide wireless solution for the automated manufacturing processes. It is well known that industrial environments characterized by extreme conditions such as high temperature, pressure, and electromagnetic (EM) interference that can affect the performance of the WSN's. The key solution to overcome this performance issue is by monitoring the received Signal Strength Index (RSSI) at the received sensor of the WSN device and track frame error rate of wireless packets.

ZigBee is a wireless sensor network (WSN) standard designed for specific needs of the ...


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 Jan 2012

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 ...


Using Metarules To Integrate Knowledge In Knowledge Based Systems. An Application In The Woodworking Industry, Alvaro Villavicencio Jan 2012

Using Metarules To Integrate Knowledge In Knowledge Based Systems. An Application In The Woodworking Industry, Alvaro Villavicencio

Dissertations and Theses @ UNI

The current study addresses the integration of knowledge obtained from Data Mining structures and models into existing Knowledge Based solutions. It presents a technique adapted from commonKADS and spiral methodology to develop an initial knowledge solution using a traditional approach for requirement analysis, knowledge acquisition, and implementation. After an initial prototype is created and verified, the solution is enhanced incorporating new knowledge obtained from Online Analytical Processing, specifically from Data Mining models and structures using meta rules. Every meta rule is also verified prior to being included in the selection and translation of rules into the Expert System notation. Once ...


A Wireless System For Crack Monitoring In Concrete Structures, Souhail M. Saad Jan 2011

A Wireless System For Crack Monitoring In Concrete Structures, Souhail M. Saad

Dissertations and Theses @ UNI

The formation of cracks in concrete is a normal phenomenon. However, effective control and prevention of the formation of cracks is the key for successful life of concrete structures. Specifically, cracks represent a path of least resistance for moisture and corrosive ionic agents from de-icing salts to reach embedded steel in concrete. Commercial wireless sensor networks utilizing crack gauge sensors can be applied for crack monitoring in the common concrete structure. The crack sensors circuits' boards, which are used to stimulate the cracks, are currently unavailable for the SG-Link module platform.

The SG-Link module is an ultra-low-power module for use ...


Wash Water In The Mix: Effects On The Compressive Strength Of Concrete, Brian Wasserman Jan 2011

Wash Water In The Mix: Effects On The Compressive Strength Of Concrete, Brian Wasserman

Dissertations and Theses @ UNI

Beginning with the Water Quality Act of 1987, requirements were put in place to control sediment run off from construction sites, which typically meant silt fences were installed and maintained on job sites. In 2009, when Aggregate Industries was fined $2.7 million by the Environmental Protection Agency (EPA) for poor management of concrete wash water, the disposal of concrete wash water became a significant issue. Following the EPA guidelines, the Minnesota Pollution Control Agency (MPCA) currently allows the dumping of excess concrete on the job sites, but requires control of all water used to wash concrete ready mix trucks ...


Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter Jan 2011

Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter

Honors Program Theses

Thin manganese films were grown by thermal evaporation in high vacuum. The growth rate was varied to determine how the growth rate affects the continuity of ultra-thin films. The resistance was measured with the two-point method in situ and the data was recorded digitally. The resistance was converted to resistivity and this was plotted against thickness. It was found that resistivity decreases exponentially as the film begins to form in islands. The film reaches a critical thickness as the islands coalesce and the data can then be fitted with Fuchs’ equation. The resistivity continues to decrease but the minimum resistivity ...


Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner Jan 2010

Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner

Honors Program Theses

After extensive review of the field of dye-sensitized solar cells, the molecule [Ru(4,4’- dicarboxy-2,2’-bipyridine)(4,4’-di-(2-(2-pyridyl)ethenyl)-2,2’-bipyridine)(NCS)2] has been designed as an original contribution to the field. This dye sensitizer was chosen by derivatizing upon the structure of the standard sensitizer, cis-diisothiocyanatobis(4,4’-dicarboxylic acid-2,2’- bipyridine)ruthenium(II) (N3), by extending the conjugation of one bipyridine ligand. This structural derivatization should enhance light harvesting by red-shifting the dye’s absorbance and increasing the dye’s molar absorptivity, which should result in a dye-sensitized solar cell ...


Detecting The Process' 1.5 Sigma Shift: A Quantitative Study, James R. Stevenson Dec 2009

Detecting The Process' 1.5 Sigma Shift: A Quantitative Study, James R. Stevenson

Dissertations and Theses @ UNI

Process behavior can change with time. In this study an attempt was made to discover whether the Six Sigma™ claim of changes in the process mean stayed within +/- 1.5 sigma units. Several process groups were examined for a particular firm that made metal castings, machined parts, tested major components and assembled these into a vehicle that was a product sold to the customer. As the assembly progressed, deficiencies were identified and recorded. Analyses employed cumulative sum (CUSUM) sequence charts, Autoregressive Integrated Moving Average (ARIMA) time series analyses, minimum mean square error (MMSE) exponentially weighted moving average (EWMA), Shewhart control ...


An Analysis Of The Effect Of Supply Chain And Manufacturing Parameters On Inventory Cost Reduction For Push Type Manufacturing Systems, Mehmet Emre Bahadir Jan 2009

An Analysis Of The Effect Of Supply Chain And Manufacturing Parameters On Inventory Cost Reduction For Push Type Manufacturing Systems, Mehmet Emre Bahadir

Dissertations and Theses @ UNI

In the global network of businesses, supply chain and order fulfillment managements are the most critical functional departments to determine the winner of the global competition. In this research a network of companies that are flowing information, product and services between providers and a receiver is investigated in order to gain a better insight of the current situation. Analyses, explanations and solutions were developed through responding to the following research questions:

(1) What are the most important variables that affect the quality and delivery performances of a supply chain?

(2) What are the most important variables that affect the service ...


Effects Of Nanoscale Disorder On The Paramagnetic To Ferromagnetic Transition In Melt-Spun Gadolinium And Gadolinium Iron Alloys, Justin Gary Bohnet Jan 2008

Effects Of Nanoscale Disorder On The Paramagnetic To Ferromagnetic Transition In Melt-Spun Gadolinium And Gadolinium Iron Alloys, Justin Gary Bohnet

Honors Program Theses

As nanoscale science continues to flourish, scientists strive to understand how structure and order (or disorder) on the nanoscale contribute to macroscopic properties, such as magnetism. This study examines alloys of gadolinium and iron that have been nanostructured through the process of melt-spinning. The result was a two-part system consisting of small (~70 nm) gadolinium grains surrounded by an amorphous gadolinium and iron matrix. Measurements of the samples’ DC magnetization and AC susceptibility were performed. By looking at the paramagnetic to ferromagnetic transition in the materials, the critical exponents were obtained and used to classify and understand how the addition ...