Engineering Commons^™

An Automated Test Station Design Used To Verify Aircraft Communication Protocols, Joshua Berrian

Master's Theses

Requirements verification is typically the costliest part of the systems engineering design process. In the commercial aircraft industry, as the software and hardware design evolves, it must be verified to conform to requirements. In addition, when new design releases are made, regression analysis must be performed which usually requires repeat testing. To streamline verification, a suite of automated verification tools is described in this document which can reduce the test effort. This test suite can be qualified to be used to verify systems at any DO-178B design assurance level. Some of the software tools are briefly described below.

There are …

Mars Carbon Dioxide Propulsion, Christopher Cushman Perry

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental investigation was conducted to characterize the performance of a small-scale supersonic propulsion system using supercritical CO₂ as a propellant intended for Mars surface applications. This research has focused on estimating the specific impulse behavior of high-pressure carbon dioxide propellant that can be produced by condensing dry ice out of Mars's atmosphere and heating it at constant volume to temperatures above its 31.1 ° C critical temperature. Since supercritical fluid was created by heating different dry ice-vapor mixtures to moderate temperatures, the nominal initial density and thermodynamic state within the pressure vessel could be controlled. The instrumented test …

Ranolazine Reduces Ca2+ Overload And Oxidative Stress And Improves Mitochondrial Integrity To Protect Against Ischemia Reperfusion Injury In Isolated Hearts, Mohammed Aldakkak, Amadou K.S. Camara, James S. Heisner, Meiying Yang, David F. Stowe

Biomedical Engineering Faculty Research and Publications

Ranolazine is a clinically approved drug for treating cardiac ventricular dysrhythmias and angina. Its mechanism(s) of protection is not clearly understood but evidence points to blocking the late Na⁺ current that arises during ischemia, blocking mitochondrial complex I activity, or modulating mitochondrial metabolism. Here we tested the effect of ranolazine treatment before ischemia at the mitochondrial level in intact isolated hearts and in mitochondria isolated from hearts at different times of reperfusion. Left ventricular (LV) pressure (LVP), coronary flow (CF), and O₂ metabolism were measured in guinea pig isolated hearts perfused with Krebs-Ringer’s solution; mitochondrial (m) O_{2 …}

Bilateral Assessment Of Functional Tasks For Robot-Assisted Therapy Applications, Michelle J. Johnson, Sarah Wang, Ping Bai, Elaine Strachota, Guennady Tchekanov, Jeff Melbye, John Mcguire

Biomedical Engineering Faculty Research and Publications

This article presents a novel evaluation system along with methods to evaluate bilateral coordination of arm function on activities of daily living tasks before and after robot-assisted therapy. An affordable bilateral assessment system (BiAS) consisting of two mini-passive measuring units modeled as three degree of freedom robots is described. The process for evaluating functional tasks using the BiAS is presented and we demonstrate its ability to measure wrist kinematic trajectories. Three metrics, phase difference, movement overlap, and task completion time, are used to evaluate the BiAS system on a bilateral symmetric (bi-drink) and a bilateral asymmetric (bi-pour) functional task. Wrist …

Region-Of-Interest Material Decomposition From Truncated Energy-Resolved Ct, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: Energy-resolved CT using photon-counting detectors has the potential to provide improved material decomposition compared to dual-kVp approaches. However, available photon-counting detectors are susceptible to pulse-pileup artifacts, especially at the periphery of the field of view (FOV) where the object attenuation is low compared to the center of the FOV. Pulse pileup may be avoided by imaging a region-of-interest (ROI) where the dynamic range is expected to be limited. This work investigated performing material decomposition and reconstructing ROI basis images from truncated energy-resolved data.

Methods: A method is proposed to reconstructimages of basis functions primarily contained within the ROI, such …

Comparison Of Four Chip-Seq Analytical Algorithms Using Rice Endosperm H3k27 Trimethylation Profiling Data., Brandon M. Malone, Feng Tan, Susan M. Bridges, Zhaohua Peng

BCoE Publications

Chromatin immunoprecipitation coupled with high throughput DNA Sequencing (ChIP-Seq) has emerged as a powerful tool for genome wide profiling of the binding sites of proteins associated with DNA such as histones and transcription factors. However, no peak calling program has gained consensus acceptance by the scientific community as the preferred tool for ChIP-Seq data analysis. Analyzing the large data sets generated by ChIP-Seq studies remains highly challenging for most molecular biology laboratories.Here we profile H3K27me3 enrichment sites in rice young endosperm using the ChIP-Seq approach and analyze the data using four peak calling algorithms (FindPeaks, PeakSeq, USeq, and MACS). Comparison …

Rational Efficiency Of A Heat Exchanger, Jim Mcgovern, Brian P. Smyth

Articles

The authors propose a new and unique definition for the rational efficiency of a heat exchanger. This new rational efficiency is defined in terms of its sub-rational efficiencies: a heat transfer rational efficiency and a friction rational efficiency for each of the fluid systems comprising the heat exchanger. The heat transfer rational efficiency is based on the definition of a mean temperature for the heat source and a mean temperature for the heat sink and reflects the exergy supplied and the exergy received, due to heat transfer only. The friction rational efficiency for each fluid system of the heat exchanger …

Stage-Dependent Transient Storage Of Phosphorus In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Ronald B. Miller, Daniel E. Storm, Amanda K. Fox, Chad J. Penn, Todd Halihan, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Models for contaminant transport in streams commonly idealize transient storage as a well-mixed but immobile system. These transient storage models capture rapid (near-stream) hyporheic storage and transport, but do not account for large-scale, stage-dependent interaction with the alluvial aquifer. The objective of this research was to document transient storage of phosphorus (P) in coarse gravel alluvium potentially influenced by large-scale, stage-dependent preferential flow pathways (PFPs). Long-term monitoring was performed at floodplain sites adjacent to the Barren Fork Creek and Honey Creek in northeastern Oklahoma. Based on results from subsurface electrical resistivity mapping which was correlated to hydraulic conductivity data, observation …

High Ethanol Titers From Cellulose By Using Metabolically Engineered Thermophilic, Anaerobic Microbes, D. Aaron Argyros, Shital A. Tripathi, Trisha F. Barrett, Stephen R. Rogers, Lawrence F. Feinberg, Daniel G. Olson, Justin M. Foden, Bethany B. Miller, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

This work describes novel genetic tools for use in Clostridium thermocellum that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native C. thermocellum hpt gene and the Thermoanaerobacterium saccharolyticum tdk gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta). The Δldh Δpta mutant was evolved for 2,000 h, resulting in a stable strain with 40:1 ethanol selectivity and a 4.2-fold increase in ethanol yield over the wild-type strain. Ethanol production from cellulose was investigated with an engineered coculture of organic acid-deficient engineered strains of …

Ridge Aperture Antenna Array As A High Efficiency Coupler For Photovoltaic Applications, Edward C. Kinzel, Pornsak Srisungsitthisunti, Xianfan Xu

Birck and NCN Publications

Weak absorption of light near the absorption band edge of a photovoltaic material is one limiting factor on the efficiency of photovoltaics. This is particularly true for silicon thin-film solar cells because of the short optical path lengths and limited options for texturing the front and back surfaces. Directing light laterally is one way to increase the optical path length and absorption. We investigate the use of a periodic array of apertures originated from bowtie aperture antennas to couple incident light into guided modes supported within a thin silicon film. We show the presence of the aperture array can increase …

Inverted Pendulum Swing Up Controller, David Kennedy, James Conlon

Conference Papers

The inverted pendulum is a classic control problem. The system is open – loop unstable and continuously wants to reach equilibrium by falling over. The system must be stabilised by means of feedback. The developed inverted pendulum system is shown in Figure 1.

In order to balance the pendulum in the inverted position the pivot must be moved continuously to correct the falling pendulum. This is similar to trying to vertically balance a broom on your hand. This interesting control problem is fundamentally the same as those involved in rocket or missile propulsion. The rocket has to balance on its …

Investigating Polymer-Tool Steel Interfaces To Predict The Work Of Adhesion For Demoulding Force Optimisation, Kevin Delaney, David Kennedy, Giuliano Bissacco

Conference Papers

Demoulding parts from replication tools is a critical stage of replication processes such as injection moulding and hot embossing. This challenge increases as part size decreases since components and associated replication cores become more fragile and liable to damage. Understanding interfacial characteristics between a polymer and the tool surface is critical to optimise the demoulding of such parts from replication tools. The strength of the polymer-tool interaction is characterised by the adhesion energy and is specific for a particular polymer-tool pair. It’s magnitude depends upon the tool material, the chemical structure of the polymer, the processing conditions and the surface …

Fpga Bootstrapping Using Partial Reconfiguration, Patrick Sutton Ostler

Theses and Dissertations

Partial reconfiguration (PR) is the process of configuring a subset of resources on a Field Programmable Gate Array (FPGA) while the remainder of the device continues to operate. PR extends the usability of FPGAs and makes it possible to perform design bootstrapping. Just like bootstrapping in PCs, bootstrapping in FPGAs consists of using a small application to initialize basic services and load a larger, more complex application to the device. Bootstrapping allows for unique design applications that can be used to maintain communication services, increase design security, reduce initial configuration time, and reduce nonvolatile configuration memory storage. This thesis presents …

A Comparison Of Finite State Classifier And Mahalanobis-Taguchi System For Multivariate Pattern Recognition In Skin Cancer Detection, Elizabeth A. Cudney, Steven M. Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

This project presents two methods for image classification for the detection of malignant melanoma: The Mahalanobis-Taguchi System and Finite State Classifiers. the Mahalanobis-Taguchi System is a diagnosis and predictive method for analyzing patterns in multivariate cases, while Finite State Classifiers are a state-based machine learning technique. the goal of this study is to compare the ability of the Mahalanobis-Taguchi System and a Finite State Classifier to discriminate using small data sets. We examine the discriminant ability as a function of data set size using publicly available skin lesion image data. While analysis of the data shows a high degree of …

Performance Analysis Of Solar Walls In Minnesota: Final Project Report, Patrick A. Tebbe, Saeed Moaveni, Louis Schwartzkopf

Mechanical and Civil Engineering Department Publications

A study of unglazed transpired solar collectors (referred to as solar walls for this report), has been undertaken. Several installations in the Twin Cities, MN region have been identified, researched, and studied. A combination of weather stations, data logging systems, and building energy management systems were used to collect experimental data on four buildings. Performance calculations were then performed for these buildings and compared with various performance/modeling tools.

Isostaticity Of Constraints In Amorphous Jammed Systems Of Soft Frictionless Platonic Solids, Kyle C. Smith, Timothy Fisher, Meheboob Alam

Birck and NCN Publications

The average number of constraints per particle < C(total)> in mechanically stable amorphous systems of Platonic solids approaches the isostatic limit at the jamming point (< C(total)> -> 12), though average number of contacts are hypostatic. By introducing angular alignment metrics to classify the degree of constraint imposed by each contact, constraints are shown to arise as a direct result of local orientational order reflected in edge-face and face-face alignment angle distributions. With approximately one face-face contact per particle at jamming, chainlike face-face clusters form with finite extent-a signature of amorphous jammed systems.

Comparison Of Computational And Experimental Aerodynamics: Results For A Wmu Solar Car Model, Yang Yang, William W. Liou

The Hilltop Review

Three-dimensional numerical simulations using FLUENT [1] were performed to model the airflow over the Sunseeker, an award-winning solar car that was designed and built at Western Michigan University. Converged numerical solutions on three different grids are reported and compared with the available experimental data, which include the lift and the drag coefficients. Also reported are the results obtained by using the second-order upwinding discretization on one of the grids. The comparison shows that the computed lift coefficients agree well with the experimental data for all the three grids and the different orders of numerical methods, indicating that the pressure field …

Evaluation Of Dye And Pigment Based Ink Jet Ink Sets, Veronika Chovancova

The Hilltop Review

The development of high performance inkjet printers and inks is advancing rapidly. Manufacturers seem to introduce their new technology inks to the market on an almost daily basis. Chemists in ink laboratories are still fighting with the issue of combining a wide gamut of dye-based inks with the lightfast and weather resistance qualities of pigment-based inks into new-age ink formulations.

Three different inkjet printers and inks were investigated in this work: the Epson Stylus® Pro 5000, using a dye-based ink set, the Epson Stylus® Pro 5500, employing Archival ink technology, and the Epson Stylus® Photo 2200, with 7-color UltraChrome™ inks. …

A Collaborative Engineering Manager Training And Certification Program, Benjamin L. Dow, William Daughton

Engineering Management and Systems Engineering Faculty Research & Creative Works

As technology has rapidly increased, so has the demand for well-trained engineering managers. the engineering management skills needed to succeed in business and industry continues to evolve and includes both organizing and directing people and projects. the American Society of Engineering Management (ASEM) has developed a training and certification program to help enhance and develop these skills. This paper explores both the ASEM training and certification efforts to date. © 2011 IEEE.

Theoretical Capacity Analysis For Multi-Hop Backscatter Communication Networks, Aditya V. Padaki, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Traditionally wireless sensor networks (WSNs) employ active RF communication where the RF signal has to be generated at nodes, thus consuming a significant amount of energy. in contrast, employment of passive communication, where nodes backscatter a modulated version of the incident RF signal, offers great advantages including reducing the energy cost of communication. Existing example includes a traditional RFID system with active reader communicating directly with passive tags. However, the proposed approach targets future, more advanced systems that support a generic backscatter communication. However, the inherent asymmetry in communication, reliance on external source of RF signal, and limited energy storage …

Cooperative Approaches Indicating To Capacity And Power Control For Ad Hoc Wireless Network, Liuju Wu, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, two integrated schemes for fair capacity allocation and power control for ad hoc wireless network are presented. the game theory approach is utilized to derive a collaborative update law. in the practical wireless network, a non-uniform distribution of nodes results in varying degree of interference among the network links or hops. Such varying mutual interference may lead to unfair allocation of bandwidth and result in network congestion. as a result, some links may become bottlenecks for the entire network. Hence, it is important to fairly allocate resources in the entire network. the proposed schemes aim to address …

Efficient Design And Synthesis Of Decimation Filters For Wideband Delta-Sigma Adcs, Rajaram Mohan Roy Koppula, Sakkarapani Balagopal, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

A design methodology for synthesizing power-optimized decimation filters for wideband Delta Sigma (ΔΣ) analog-to-digital converters (ADCs) for next-generation wireless standards is presented. The decimation filter is designed to filter the out-of-band quantization noise from a fifth-order continuous-time ΔΣ modulator, with 20 MHz signal bandwidth and 14-bits resolution. The modulator employs an oversampling ratio (OSR) of 16 with a clock rate of 640 MHz. Retiming, pipelining, Canonical Signed Digits (CSD) encoding has been utilized along with an optimized halfband filter to realize the power savings in the overall decimation filter. A process flow to rapidly design the optimized filters in MATLAB, …

Solving The Capacitated Vehicle Routing Problem With Environmental Criteria Based On Real Estimations In Road Transportation: A Case Study, Javier Faulin, Angel Juan, Fernando Lera, Scott Erwin Grasman

Engineering Management and Systems Engineering Faculty Research & Creative Works

One of the most important objectives in company logistics is the optimization of goods distribution considering the whole value chain. There are many algorithms to optimize the capacitated vehicle routing problems (CVRP) associated to problems of road transportation. the objective function of those problems usually involves distance, cost, number of vehicles, or profits, among others. in this contribution we also take into account environmental costs. Here, we want to manage environmental costs estimations based on surveys about road transportation crossing rural areas having valuable biological and natural stock. Thus, we develop some variants (AWEC) to traditional heuristic algorithms, such as …

Radiation Effects Basics For 7750, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs on "Radiation Effects Basics for 7750" on September 25, 2011.

Experimental And Atomistic Theoretical Study Of Degree Of Polarization From Multilayer Inas/Gaas Quantum Dot Stacks, Muhammad Usman, Tomoya Inoue, Yukihiro Harda, Gerhard Klimeck, Takashi Kita

Birck and NCN Publications

Recent experimental measurements, without any theoretical guidance, showed that isotropic po- larization response can be achieved by increasing the number of QD layers in a QD stack. Here we analyse the polarization response of multi-layer quantum dot stacks containing up to nine quan- tum dot layers by linearly polarized PL measurements and by carrying out a systematic set of multi-million atom simulations. The atomistic modeling and simulations allow us to include cor- rect symmetry properties in the calculations of the optical spectra: a factor critical to explain the experimental evidence. The values of the degree of polarization (DOP) calculated from …

Lifetime Enhanced Transport In Silicon Due To Spin And Valley Blockade, Gabriel Lansbergen, Rajib Rahman, J. Verdujin, Giuseppe Tettamanzi, Nadine Collaert, Serge Biesemans, Gerhard Klimeck, Lloyd Hollenberg, Sven Rogge

Birck and NCN Publications

We report the observation of Lifetime Enhanced Transport (LET) based on perpendicular valleys in silicon by transport spectroscopy measurements of a two-electron system in a silicon transistor. The LET is manifested as a peculiar current step in the stability diagram due to a forbidden transition between an excited state and any of the lower energy states due perpendicular valley (and spin) configurations, offering an additional current path. By employing a detailed temperature dependence study in combination with a rate equation model, we estimate the lifetime of this particular state to exceed 48 ns. The two-electron spin-valley configurations of all relevant …

Effects Of Pressure On The Properties Of Coal Char Under Gasification Conditions At High Initial Heating Rates, Randy C. Shurtz

Theses and Dissertations

The effects of elevated pressure and high heating rates on coal pyrolysis and gasification were investigated. A high-pressure flat-flame burner (HPFFB) was designed and built to conduct these studies. The HPFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ~10^5 K/s, pressures of up to 15 atm, and gas temperatures of up to 2000 K. Residence times were varied from 30 to 700 ms in this study. Pyrolysis experiments were conducted at particle heating rates of ~10^5 K/s and maximum gas temperatures of ~1700 K at pressures of 1 to 15 atm. …

Toward The Design Of A Statically Balanced Fully Compliant Joint For Use In Haptic Interfaces, Levi Clifford Leishman

Theses and Dissertations

Haptic interfaces are robotic force-feedback devices that give the user a sense of touch as they interact with virtual or remote environments. These interfaces act as input devices, mapping the 3-dimensional (3D) motions of the user's hand into 3D motions in a slave system or simulated virtual world. A major challenge in haptic interfaces is ensuring that the user's experience is a realistic depiction of the simulated environment. This requires the interface's design to be such that it does not hinder the user's ability to feel the forces present in the environment. This "transparency" is achieved by minimizing the device's …

Adaptive Control In Swarm Robotic Systems, Hanyi Dai

The Hilltop Review

Inspired by the collective behavior observed in natural insects, swarm robotics is a new approach in designing control algorithms for a large group of robots performing a certain task. In such robotic systems, an individual robot with only limited capabilities in terms of sensing, computation, and communication can adapt its own behavior so that a desired collective behavior emerges from the local interactions among robots and between robots and the environment. Swarm robotics has been the focus of increased attention recently because of the beneficial features demonstrated in such systems, such as higher group efficiency, robustness against the failures of …

The Study Of Ink Pigment Dispersion Parameters, Lokendra Pal, Paul D. Fleming Iii

The Hilltop Review

The purpose of this study was to investigate the influence of rotation speed and milling time on the pigment dispersion quality. The information can be used to obtain a standard laboratory condition at which a wide range of pigments may be dispersed to formulate water-based rotogravure inks. The influence of pigment concentration and shear forces on the pigment dispersion were also studied.

The procedure consisted of dispersing the pigment using a laboratory Dispermat® SL bead mill at various milling times with two different rotation speeds and measuring the particle size and particle size distribution of the milled samples. The pigment …