Engineering Commons^™

Nebraska Summary: S1127 Challenger Mt495e, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

A Standards-Based Grading Model To Predict Students' Success In A First-Year Engineering Course, Farshid Marbouti

Open Access Dissertations

Using predictive modeling methods, it is possible to identify at-risk students early in the semester and inform both the instructors and the students. While some universities have started to use standards-based grading, which has educational advantages over common score-based grading, at–risk prediction models have not been adapted to reap the benefits of standards-based grading. In this study, seven prediction models were compared to identify at-risk students in a course that used standards-based grading. When identifying at-risk students, it is important to minimize false negative (i.e., type II) errors while not increasing false positive (i.e., type I) errors significantly. To increase …

In Situ Microscopy Of The Self-Assembly Of Branched Nanocrystals In Solution, Eli Sutter, Peter Sutter, Alexei V. Tkachenko, Roman Krahne, Joost De Graaf, Milena Arciniegas, Liberato Manna

Department of Mechanical and Materials Engineering: Faculty Publications

Solution-phase self-assembly of nanocrystals into mesoscale structures is a promising strategy for constructing functional materials from nanoscale components. Liquid environments are key to self-assembly since they allow suspended nanocrystals to diffuse and interact freely, but they also complicate experiments. Real-time observations with single-particle resolution could have transformative impact on our understanding of nanocrystal self-assembly. Here we use real-time in situ imaging by liquid-cell electron microscopy to elucidate the nucleation and growth mechanism and properties of linear chains of octapod-shaped nanocrystals in their native solution environment. Statistical mechanics modelling based on these observations and using the measured chain-length distribution clarifies the …

Influence Of Shear Stress Magnitude And Direction On Atherosclerotic Plaque Composition, Ryan M. Pedrigi, Vikram V. Mehta, Sandra M. Bovens, Zahra Mohri, Christian Bo Poulsen, Willy Gsell, Jordi L. Tremoleda, Leila Towhidi, Ranil De Silva, Enrico Petretto, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The precise flow characteristics that promote different atherosclerotic plaque types remain unclear. We previously developed a blood flow-modifying cuff for ApoE^−/− mice that induces the development of advanced plaques with vulnerable and stable features upstream and downstream of the cuff, respectively. Herein, we sought to test the hypothesis that changes in flow magnitude promote formation of the upstream (vulnerable) plaque, whereas altered flow direction is important for development of the downstream (stable) plaque. We instrumented ApoE^−/− mice (n=7) with a cuff around the left carotid artery and imaged them with micro-CT (39.6 μm resolution) eight to nine weeks …

Effects Of Altitude On Monarch Butterfly Aerodynamics, Brittany Greene

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Experimental Strain Measurement In Ultrasonic Welding Of Battery Tabs, Chen Chen

Wayne State University Theses

Lithium-ion battery is one the most popular types of batteries currently used in electric

vehicles. To meet the power requirement, hundreds of Lithium ion battery cells are connected together before being assembled into a battery pack. Ultrasonic welding is the most widely used joining technology to connect battery cells together. In an ultrasonic welding process, high frequency oscillation is used to generate small relative motions between sheet metals to be welded, and produce solid-state bonds between the sheet metals clamped under pressure. One of the major issues for battery pack ultrasonic welding is that sometimes the welding process damages the …

Quantitative Assessment Of Brain Iron Content As A Function Of Age Using Magnetic Resonance Imaging, Kiarash Ghassaban

Wayne State University Theses

As the most abundant transition metal in the brain, iron is known to play a key role in a variety of functional and cellular processes. Recent in vivo and post-mortem studies have shown that the levels of iron deposition in the brain, particularly in deep gray matter nuclei, vary as a function of age. On the other hand, elevated iron has also been associated with some neurodegenerative diseases such as Multiple Sclerosis (MS) and Parkinson’s disease (PD) among others.

Magnetic Resonance Imaging (MRI) is a widely used non-invasive and non-ionizing imaging modality which is sensitive to magnetic properties of materials …

Bio-Inspired Synthesis Of Nanostructured Materials On Substrates For Environmental And Energy Applications, Xinghua Meng Meng

Wayne State University Dissertations

It is still a challenging task to develop simple methods for facile synthesis of functional nanostructures on substrates under mild conditions without using expensive instruments. We have successfully developed a bio-inspired method using simple diaphragm-assisted system to synthesize functional nanostructures on various substrates under mild conditions. We have systematically studied the effects of experimental parameters on the formation of nanostructures under controlled conditions. The fundamental mechanism involved has been systematically studied and revealed. By growing the unique networks of nanostructures on a piece of substrate, a double-rough surface, with structures at both nanoscale and microscale, has been achieved, showing interesting …

Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance, Sabarish Chandramohan

Wayne State University Dissertations

For the fabrication, focused ion beam parameters are investigated to successfully fabricate dense periodical patterns, such as gratings, on hard transition metal nitride such as zirconium nitride. Transition metal nitrides such as titanium nitride and zirconium nitride have recently been studied as alternative materials for plasmonic devices because of its plasmonic resonance in the visible and near-infrared ranges, material strength, CMOS compatibility and optical properties resembling gold. Coupling of light on the surface of these materials using sub-micrometer gratings gives additional capabilities for wider applications. Here we report the fabrication of gratings on the surface of zirconium nitride using gallium …

Substrate Effects And Dielectric Integration In 2d Electronics, Bhim Prasad Chamlagain

Wayne State University Dissertations

The ultra-thin body of monolayer (and few-layer) two dimensional (2D) semiconducting materials such as transitional metal dichalconiges (TMDs), black phosphorous (BP) has demonstrated tremendous beneficial physical, transport, and optical properties for a wide range of applications. Because of their ultrathin bodies, the properties of 2D materials are highly sensitive to environmental effects. Particularly, the performance of 2D semiconductor electronic devices is strongly dependent on the substrate/dielectric properties, extrinsic impurities and absorbates. In this work, we systematically studied the transport properties of mechanically exfoliated few layer TMD field-effect transistors (FETs) consistently fabricated on various substrates including SiO2,Parylene –C, Al2O3, SiO2 modified …

An Automated System To Measure The Quantum Efficiency Of Ccds For Astronomy, Rebecca Ann Coles

Wayne State University Dissertations

We describe a system to measure the Quantum Efficiency in the wavelength range of 300nm to 1100nm of 40x40 mm n-channel CCD sensors for the construction of the 3.2 gigapixel LSST focal plane. The technique uses a series of instruments to create a very uniform flux of photons of controllable intensity in the wavelength range of interest across the face the sensor. This allows the absolute Quantum Efficiency to be measured with an accuracy in the 1% range. This system will be part of a production facility at Brookhaven National Lab for the basic component of the LSST camera.

Improved Direct Power Control For 3-Level Ac/Dc Converter Under Unbalanced And/Or Distorted Voltage Source Conditions, Imad Merzouk, Mohamed Lokmane Bendaas

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an improved direct power control with space vector modulation for a 3-phase 3-level neutral point clamped converter supplied by unbalanced and/or distorted grid voltage is proposed. The main objective of the control scheme is to obtain balanced and sinusoidal input current with unity power factor under nonideal voltage supply. To achieve the control objectives, compensated active and reactive powers are calculated and added to the referencing one. A theoretical analysis of active and reactive power under a nonideal source is clearly demonstrated. In order to calculate the compensated powers, the extraction of positive, negative, and harmonic sequences …

Theoretical Analysis Of Doping Management And Its Effects On Power Scaling, Ami̇ra Tandi̇rovi̇ç Gürsel, Parvi̇z Elahi̇, Fati̇h Ömer İlday, Mustafa Sadetti̇n Özyazici

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

A Robust Bayesian Inference-Based Channel Estimation In Power Line Communication Systems Contaminated By Impulsive Noise, Mohammad Asadpour, Behzad Mozaffari Tazehkand, Hadi Seyedarabi

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Studies On The Application Of Wavelet Families For A High Impedance Fault Location Algorithm In A Distribution Network, Mohd Syukri Ali, Ab Halim Abu Bakar, Chia Kwang Tan, Hazlie Mokhlis, Hamzah Arof

Turkish Journal of Electrical Engineering and Computer Sciences

Detecting high impedance faults in a distribution network is a great challenge and locating one is even more challenging. This paper will present an enhanced high impedance fault location algorithm based on the database technique. This paper is an extension of a faulty section identification algorithm developed previously. However, in this paper, the performance of the previous algorithm is investigated first in terms of different sampling rate and window size. Then these parameters will be used as a standard parameter to study the effectiveness of different types of mother wavelets. Each mother wavelet will be used to extract important features …

Modeling Long-Term Deformations Of Unbound Pavement Materials Using The Miniaturized Pressuremeter Creep Data, A. M. Shaban, P. J. Consentino

Mechanical and Civil Engineering Faculty Publications

This research was undertaken to study the predictive capability of the pressuremeter test for characterizing in situ creep behavior of unbound pavement layers. Although the creep potential of granular pavement materials is less pronounced than fine-grained soils, consideration of actual creep deformations in the pavement evaluation process will improve long-term pavement performance. In this investigation, the long-term deformations determined from laboratory one-dimensional creep tests were compared with those investigated by field pressuremeter tests. The pressuremeter test consisted of inflating a cylindrical probe incrementally up to a given stress level, and then maintaining the pressure constant for a 5-min single stage. …

Modeling Fluid Interactions With Granular And Fibrous Surfaces, Mana Mokhtabad Amrei

Theses and Dissertations

Understanding the interactions between a body of liquid and a curvy surface is important for many applications such as underwater drag force reduction, droplet filtration, self-cleaning, and fog harvesting, among many others. This study investigates ways to predict the performance of granular and fibrous surfaces for some of the above applications. More specifically, our study is focused on 1) modeling the mechanical stability of the air-water interface over submerged superhydrophobic (SHP) surfaces and their expected drag reduction benefits, and 2) predicting the mechanical stability of a droplet on a fiber in the presence of an external body force. For the …

Supervision Of Community Based Microgrids: An Economic Model Predictive Control Approach, Francesco Tedesco, Lubna Mariam, Malabika Basu, Alessandro Casavola, Michael F. Conlon

Conference papers

Abstract— In this paper, an Economic Model Predictive Control (EMPC) approach has been presented to manage a Community-based microgrid (C-µGCC) at the pricing level. The main task is at satisfying the demand at prosumer sides and, at the same time, optimizing various µ-Grid contrasting objectives. Emphasis has been given to the operational constraints related to the components lifetime, whose satisfaction would be beneficial for the grid in that the maintenance and replacement costs would be reduced. A simulative analysis has been carried out on the basis of available measured data related to a location in Dublin, Ireland. Results show the …

Spontaneous Mirror-Symmetry Breaking In Different Non-Chiral Liquid Crystalline Systems, Yuri Panarin

Conference papers

Spontaneous Mirror-Symmetry and appearance of chiral self-assembled superstructures in non-chiral systems represents a fascinating field of contemporary research with potential applications. For long time the formation of helical superstructure was associated with enantiomeric chiral molecules. Later on Pasteur showed that that the racemic mixtures of chiral molecules can resolve spontaneously into two chiral forms. Such deracemization or symmetry breaking in racemic mixtures was observed during crystallization. In recent years interest in mirror-symmetry breaking extended to soft matter systems.

The Accuracy Of A 2d And 3d Dendritic Tip Scaling Parameter In Predicting The Columnar To Equiaxed Transition (Cet), M. Seredynski, Marek Rebow, J. Banaszek

Conference papers

The dendrite tip kinetics model accuracy relies on the reliability of the stability constant used, which is usually experimentally determined for 3D situations and applied to 2D models. The paper reports authors` attempts to cure the situation by deriving 2D dendritic tip scaling parameter for aluminium-based alloy: Al-4wt%Cu. The obtained parameter is then incorporated into the KGT dendritic growth model in order to compare it with the original 3D KGT counterpart and to derive two-dimensional and three-dimensional versions of the modified Hunt’s analytical model for the columnar-to-equiaxed transition (CET). The conclusions drawn from the above analysis are further confirmed through …

Comparative Study Between Direct Load Control And Fuzzy Logic Control Based Demand Response, Chittesh Veni Chandran, Malabika Basu, Keith Sunderland

Conference papers

Demand response (DR), as part of Demand side management (DSM), is a method that modifies consumer side energy consumption. By actively controlling the time associated with electricity consumption, both energy and economic efficiencies are increased. There is however, depending on the algorithm employed, potential for consumer comfort levels to be adversely affected. Generally direct load (Boolean logic) control is employed, which solely considers demand reduction and not customer comfort. In comparison, fuzzy logic based programs can consider non-deterministic inputs such as consumer comfort level with ease and simplicity. This paper considers the evolution of DR through a comparison of the …

Exploring The Role Of Spatial Cognition In Problem Solving, Gavin Duffy, Sheryl Sorby, Steven Nozaki, Brian Bowe

Conference papers

While spatial aptitude is acknowledged as a key cognitive ability that accompanies success in STEM education, less is reported about the qualitative differences between weak and strong visualisers in how they approach and engage with assessments in STEM education. In this paper, we study one particular aspect of the STEM curriculum - solving convergent ‘word’ problems in mathematics - in an attempt to discern quantitative and qualitative differences between the approaches weak and strong visualisers adopt when solving these problems. The paper is a work-in-progress that started with a search for suitable convergent mathematics problems which were then presented to …

Analysis Of Glottal Source Parameters In Parkinsonian Speech, Jane Hanratty, Catherine Deegan, Mary Walsh, Barry Kirkpatrick

Conference papers

Diagnosis and monitoring of Parkinson's disease has a number of challenges as there is no definitive biomarker despite the broad range of symptoms. Research is ongoing to produce objective measures that can either diagnose Parkinson's or act as an objective decision support tool. Recent research on speech based measures have demonstrated promising results. This study aims to investigate the characteristics of the glottal source signal in Parkinsonian speech. An experiment is conducted in which a selection of glottal parameters are tested for their ability to discriminate between healthy and Parkinsonian speech. Results for each glottal parameter are presented for a …

Development Of Low-Temperature Atomic Layer Deposition Of Ultra-Thin Ruco Direct Plate Liners For Flexible Electronics Applications, Dillon Alexander Gregory

Legacy Theses & Dissertations (2009 - 2024)

Low temperature plasma-assisted atomic layer deposition-grown metal nanocomposite layers based on mixtures of ruthenium and cobalt have been investigated as potential copper adhesion/barrier layers in flexible electronics applications. The success of adapting this process to flexible electronics depends on the candidate barriers meeting several necessary properties including sufficient electrical conductivity, compatibility with Cu electroplating, and ability to prevent Cu diffusion into the substrate. Preliminary testing has shown that atomic layer deposition (ALD) can be used as a technique for depositing alloyed metallic barrier layers at the lower thermal constraints dictated by the use of polymer substrates and still produce continuous …

Texture And Microstructure Of Ipvd Copper Manganese Seed In 1 Μm & 70 Nm Wide Damascene Trenches, Robert Stuart Brown

Legacy Theses & Dissertations (2009 - 2024)

This thesis describes the grain texture and microstructure of Ionized Physical Vapor Deposition (iPVD) Copper Manganese seed in 1 µm and 70 nm wide damascene trenches. Using Transmission Electron Microscopy (TEM) imaging and diffraction pattern analysis, the grain size and general orientation of the grains were determined. It was found that the 1 µm wide trenches contained larger grains and more texture than that of the 70 nm wide trenches. While this thesis builds upon previous work by Brendan O’Brien in the Dunn group, one significantly different finding will be presented regarding the structure on the sidewall of the trenches. …

The Investigation Of Nanoscale Effects On Schottky Interfaces And The Scattering Rates Of High Resistivity Metals, Christopher Anthony Durcan

Legacy Theses & Dissertations (2009 - 2024)

Understanding the transport of electrons through materials and across interfaces is fundamental to modern day electronics. As electrons travel, interactions with defects within the crystal lattice induce scattering which gives rise to resistivity. At the interface between two materials, electrostatic barriers exist which can impede the flow of electrons. The work of this thesis is to further the understanding of electron transport by measuring the transport across metal-semiconductor interfaces at the nanoscale and measure scattering phenomena in metals. The measurement technique ballistic electron emission microscopy (BEEM) was used due to its ability to probe the scattering processes within a metal …

Experimental And Theoretical Investigations Of Cadmium Diffusion In Vacancy-Rich Cu(In, Ga)Se₂ Material, Norb Biderman

Legacy Theses & Dissertations (2009 - 2024)

Copper indium gallium selenide (Cu(In,Ga)Se2 or CIGS) has become a significant topic of research and development for photovoltaic application. CIGS photovoltaic devices have demonstrated record conversion efficiencies however are still below the maximum solar conversion efficiency. Losses in performance have been attributed structural defects including vacancies, doping, grain boundaries, and compositional non-uniformity that are poorly understood and controlled.

Investigating The Size Dependent Material Properties Of Nanoceria, Bushra B. Alam

Legacy Theses & Dissertations (2009 - 2024)

Nanoceria is widely being investigated for applications as support materials for fuel cell catalysts, free radical scavengers, and as chemical and mechanical abrasives due to its high antioxidant capacity and its oxygen buffering capacity. This antioxidant or oxygen buffering capacity has been reported to be highly size dependent and related to its redox properties. However, the quantification of this antioxidant capacity has not been well defined or understood and has been often been carried out using colorimetric assays which do not directly correlate to ceria nanoparticle properties. Fabrication rules for developing materials with optimal antioxidant/oxygen buffering capacities are not yet …

Investigation Of Contact Properties At Metal Graphene Junctions, Their Degradation And Intrinsic Limitations, Zhenjun Zhang

Legacy Theses & Dissertations (2009 - 2024)

Graphene is a two-dimensional material, comprised of a monolayer of carbon in a hexagonal lattice. Since 2004, the most promising applications of this material are high frequency devices (such as mixers and power amplifiers), as well as flexible and transparent electronics. However, these applications can’t be realized without a proper contact metal. With more understanding of the contact properties, the range of prospects for graphene’s applications can be better defined.

Development Of Enhanced Window Layers For Cigs Photovoltaic Devices, James Nicholas Alexander

Legacy Theses & Dissertations (2009 - 2024)

Photovoltaic devices are among the promising options for sustainable future energy generation. Thin film solar cells have demonstrated the ability to be a low-cost solution to clean renewable energy and are cost competitive with current silicon based photovoltaic devices. One of the most promising thin film devices right now is the Copper Indium Gallium Selenide (CIGS) solar cell with maximum reported power conversion efficiency of 22.3%. The Transparent Conducting Oxide (TCO) which is the top layer of the CIGS device also known as the window layer, is responsible for collecting the electrons generated in the CIGS device and conducting them …