Engineering Commons^™

On The Best Bandstructure For Thermoelectric Performance: A Landauer Perspective, Changwook Jeong, Raseong Kim, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The question of what bandstructure produces the best thermoelectric device performance is revisited from a Landauer perspective. We find that a delta-function transport distribution function (TDF) results in operation at the Mahan-Sofo upper limit for the thermoelectric figure-of-merit, ZT. We show, however, the Mahan-Sofo upper limit itself depends on the bandwidth (BW) of the dispersion, and therefore, a finite BW dispersion produces a higher ZT when the lattice thermal conductivity is finite. Including a realistic model for scattering profoundly changes the results. Instead of a narrow band, we find that a broad BW is best. The prospects of increasing ZT …

Processes Involving Acid Gas Solubility In Room Temperature Ionic Liquids (Rtils), Fadekemi E. Osideinde

Electronic Theses and Dissertations

The literature contains a number of thermodynamic studies involving the solubility of acid gases in RTILs. This thesis looks at using these studies in the context of two processes: membrane separation and absorption refrigeration cycles. The first part of this study investigated the separation of a mixed dry gas feed of CO2/CH4 by four Stabilized Ionic Liquid Membranes (SILMs); 1-Ethyl-3-methlyimidazolium dicyanamide, [emim][DCA], 1-ethyl-3-methylimidazolium thiocyanate, [emim][SCN], 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [emim][Tf2N] and 1-Butyl-3-methylimidazolium nitrate, [bmim][NO 3]. The selectivities and permeances for the CO2/CH 4 feed were measured in all four SILMs at various partial pressures of CO2 in the feed and at two …

Predicting Success Or Failure Of Immunotherapy For Cancer: Insights From A Clinically Applicable Mathematical Model, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The objective of this study was to create a clinically applicable mathematical model of immunotherapy for cancer and use it to explore differences between successful and unsuccessful treatment scenarios. The simplified predator-prey model includes four lumped parameters: tumor growth rate, g; immune cell killing efficiency, k; immune cell signaling factor, λ; and immune cell half-life decay, μ. The predator-prey equations as functions of time, t, for normalized tumor cell numbers, y, (the prey) and immunocyte numbers, x, (the predators) are: dy/dt = gy – kx and dx/dt = λxy – μx. A parameter estimation procedure that capitalizes on available clinical …

Optimizing Electrode Placement For Hemodynamic Benefit In Cardiac Resynchronization Therapy, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Background: Research is needed to explore the relative benefits of alternative electrode placements in biventricular and left ventricular pacing for heart failure with left bundle branch block (LBBB). Methods: A fast computational model of the left ventricle, running on an ordinary laptop computer, was created to simulate the spread of electrical activation over the myocardial surface, together with the resulting electrocardiogram, segmental wall motion, stroke volume, and ejection fraction in the presence of varying degrees of mitral regurgitation. Arbitrary zones of scar and blocked electrical conduction could be modeled. Results: Simulations showed there are both sweet spots and poor spots …

Climatic Effects Of The Chicxulub Impact Ejecta, Devon Parkos, Marat Kulakhmetov, Brandon Johnson, Henry J. Melosh, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Examining the short and long term effects of the Chicxulub impact is critical for understanding how life developed on Earth. While the aftermath of the initial impact would have produced harmful levels of radiation sufficient for eradicating a large portion of terrestrial life, this process does not explain the concurrent marine extinction. Following the primary impact, a large quantity of smaller spherules would de-orbit and re-enter the earths atmosphere, dispersed nearly uniformly across the planet. This secondary wave of debris would re-enter at high velocities, altering the chemical composition of the atmosphere. Furthermore, the combined surface area for the spherules …

An Analysis Of Step, Jt, And Pdf Format Translation Between Constraint-Based Cad Systems With A Benchmark Model, Dillon Mckenzie-Veal

Department of Computer Graphics Technology Degree Theses

This research was conducted to provide greater depth into the ability of STEP AP 203 Edition 2, JT, and 3D PDF to translate and preserve information while using a benchmark model. The benchmark model was designed based on four industry models and created natively in the five industry leading 3D CAD programs. The native CAD program models were translated using STEP, JT, and 3D PDF. Several criteria were analyzed along the paths of translation from one disparate CAD program to another. Along with the analysis of the three interoperable file formats a survey was conducted to determine how well the …

Evaluating Net-Zero Energy Houses From The U.S. Department Of Energy Solar Decathlon 2011, Jordan P. Wallpe, William J. Hutzel, Gregory Lasker, Clark Cory

School of Engineering Technology Faculty Publications

The Solar Decathlon is a two year, international project where university students compete to design, build, and test energy-efficient, net-zero homes. By definition, net-zero energy houses annually produce as much electricity as they consume. The 2011 Solar Decathlon, held in Washington D.C., had 19 university teams from around the world.

Unfortunately, many past Solar Decathlon houses have traditionally been very costly. However, the 2011 Solar Decathlon was the first competition to have an affordability contest. The affordability contest required each home to be valued under an estimated builder’s cost of $250,000, forcing the teams to select economically feasible solutions for …

An Optimization Approach To Indoor Location Problem Based On Received Signal Strength, Lei Zheng

Browse all Theses and Dissertations

This research was motivated by the desire of a Fortune 100 retail company to track its customers' behaviors through the implementation of a low-cost indoor location system using received signal devices. Indoor location through received signal strength (RSS) is of low costs, yet it suffers from poor accuracy due to lack of direct line-of-sight, multi-path ratio propagation, and various interferences. To improve its location estimation accuracy, therefore, we propose a mathematical programming based propagation approach for RSS based location systems. The core of our approach is an optimization model that minimizes the sum of squared errors of signal strength. In …

Knowledge-Enabled Engineering Design: Toward An Integrated Model, Michael Fosmire, David Radcliffe

Libraries Faculty and Staff Scholarship and Research

Librarians and engineering faculty have long understood that design is one of the defining processes of the engineering profession. In an increasingly knowledge-driven society, students need to efficiently locate, assess and integrate relevant information into their design process so that they can develop innovation solutions to emerging complex, global grand challenges. Increasingly, engineering curricula are incorporating design as early as the first year, but a question remains as to how effectively information literacy is being integrated into these early experiences of design. For example, the Engineering Change study found there has been very little improvement to lifelong learning skills in …

Shear And Dilational Interfacial Rheology Of Surfactant-Stabilized Droplets, Kendra Erk, Jeffrey D. Martin, Jonathan T. Schwalbe, Frederick R. Phelan Jr., Steven D. Hudson

School of Materials Engineering Faculty Publications

A new measurement method is suggested that is capable of probing the shear and dilational interfacial rheological responses of small droplets, those of size comparable to real emulsion applications. Freely suspended aqueous droplets containing surfactant and non-surface-active tracer particles are transported through a rectangular microchannel by the plane Poiseuille flow of the continuous oil phase. Optical microscopy and high-speed imaging record the shape and internal circulation dynamics of the droplets. Measured circulation velocities are coupled with theoretical descriptions of the droplet dynamics in order to determine the viscous (Boussinesq) and elastic (Marangoni) interfacial effects. A new Marangoni-induced stagnation point is …

A Study Of Field Emission Process In Electrostatically Actuated Mems Switches, L Michalas, A Garg, A Venkattraman, M Koutsoureli, Alina A. Alexeenko, Dimitrios Peroulis, G Papaioannou

School of Aeronautics and Astronautics Faculty Publications

A study of field emission process in MEMS-based capacitor/switch-like geometries is presented. High resolution current-voltage characteristics up to breakdown have been obtained across micro-gaps in fixed-fixed Metal-Air- Metal and Metal-Air-Insulator-Metal structures. In metallic devices the I-V dependence reveals Fowler –Nordheim theory effects. In the presence of insulator the process is found to be limited by the film conductivity following Poole –Frenkel dependence. The data analysis reveals the major importance of surface asperities on the onset of the field emission process while it is also presented that charge transfer may occur between metal and insulator surfaces even in the presence of …

Nonlinear Effects In Squeeze Film Gas Damping On Microbeams, S Chigullapalli, A Weaver, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

We consider squeeze film gas damping during microbeam motion away and toward a substrate as occurs during opening and closing of RF switches and other MEMS devices. The numerical solution of the gas damping problem in two-dimensional geometries is obtained based on the Boltzmann-ESBGK equation. The difference in damping force between downward and upward moving beams is shown to vary from as little from as 5% for low beam velocities of 0.1m/s to more than 200% at 2.4m/s. For a constant velocity magnitude of 0.8m/s, this difference increases from 60% to almost 90% when the pressure is reduced by an …

Immersed Boundary Method For Boltzmann Model Kinetic Equations, Cem Pekardan, Sruti Chigullapalli, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Three different immersed boundary method formulations are presented for Boltzmann model kinetic equations such as Bhatnagar-Gross-Krook (BGK) and Ellipsoidal statistical Bhatnagar-Gross-Krook (ESBGK) model equations. 1D unsteady IBM solution for a moving piston is compared with the DSMC results and 2D quasi-steady microscale gas damping solutions are verified by a conformal finite volume method solver. Transient analysis for a sinusoidally moving beam is also carried out for the different pressure conditions (1 atm, 0.1 atm and 0.01 atm) corresponding to Kn=0.05,0.5 and 5. Interrelaxation method (Method 2) is shown to provide a faster convergence as compared to the traditional interpolation scheme …

Binary Scattering Model For Lennard-Jones Potential: Transport Coefficients And Collision Integrals For Non-Equilibrium Gas Flow Simulations, Ayyaswamy Venkattraman, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

A Lennard-Jones (LJ) binary interaction model for dilute gases is obtained by representing the exact scattering angle as a polynomial expansion in non-dimensional collision variables. Rigorous theoretical verification of the model is performed by comparison with exact values of diffusion and viscosity cross sections and related collision integrals. The collision quantities given by the polynomial approximation model agree within 3.5% with those of the exact LJ scattering. The proposed model is compared in detail with the generalized soft sphere (GSS) model which is the closest in terms of fidelity among existing direct simulation Monte Carlo collision models. The GSS model's …

Resolving Structure And Mechanical Properties At The Nanoscale Of Viruses With Frequency Modulation Atomic Force Microscopy, David Martinez-Martin, Carolina Carrasco, Mercedes Hernando-Pérez, P. J. De Pablo, Júlio Gómez-Herrero, Rebeca Pérez, Mauricio Garcia Mateu, José López Carrascosa, Daniel Roy Kiracofe, John C. Melcher, Arvind Raman

School of Mechanical Engineering Faculty Publications

Structural Biology (SB) techniques are particularly successful in solving virus structures. Taking advantage of the symmetries, a heavy averaging on the data of a large number of specimens, results in an accurate determination of the structure of the sample. However, these techniques do not provide true single molecule information of viruses in physiological conditions. To answer many fundamental questions about the quickly expanding physical virology it is important to develop techniques with the capability to reach nanometer scale resolution on both structure and physical properties of individual molecules in physiological conditions. Atomic force microscopy (AFM) fulfills these requirements providing images …

A Retrospective Study Of The Elementary School Experiences, Influences, Skills, And Traits Of Talented Engineers, Michele L. Strutz

School of Engineering Education Graduate Student Series

No abstract provided.

Access And Definition: Exploring How Stem Faculty, Department Heads, And University Policy Administrators Navigate The Implementation Of A Parental Leave Policy, Corey T. Schimpf, Marisol Mercado Santiago, Alice L. Pawley

School of Engineering Education Graduate Student Series

Access and Definition: Exploring how STEM Faculty, Department Heads and University Policy Administrators Navigate the Enactment of a Parental Leave Policy A key feature in various reports exploring women’s persisting underrepresentation in STEM faculty positions in the US is the need to disseminate policy information to all stakeholders involved in issues relating to women STEM faculty underrepresentation and retention. Indeed, the National Academies of Science Beyond Barriers and Bias: Fulfilling the Potential of Women Academic Science and Engineering (2007) and the AAUW’s Why so Few?(2010) identify institutional policies, like parental leave, as a way to address an outmoded institutional structure …

Engineering Evaluation Of Multi-Beam Satellite Antenna Boresight Pointing Using Land/Water Crossings, Catherine Susan May

Electronic Theses and Dissertations

The Microwave Radiometer (MWR) on the Aquarius/SAC-D mission measures microwave radiation from earth and intervening atmosphere in terms of brightness temperature (Tb). It takes measurements in a push-broom fashion at K (23.8GHz) and Ka (36.5 GHz) band frequencies using two separate antenna systems, each producing eight antenna beams. Pre-launch knowledge of the alignment of these beams with respect to the space-craft is used to geolocate the antenna footprints on ground. As a part of MWR’s on-orbit engineering check-out, the verification of MWR’s pointing accuracy is discussed here. The technique used to assess MWR’s pointing involved comparing the radiometer image of …

Intricate Dynamics And Hydrodynamic Frictional Losses Of The Piston-Ring Assembly In Internal Combustion Engines, Mohannad Hakeem

Wayne State University Dissertations

Frictional losses in internal combustion engines approximately account for 10% of the expended fuel energy. Moreover, forty percent of these losses are attributed to the reciprocating motion of the piston-assembly. Besides the adverse effect of friction on fuel economy, the intricate dynamics of the piston-assembly tend to significantly influence the thermal efficiency through blow-by, the engine durability through wear, and the engine noise through piston-slap. Moreover, 40 to 80% of the lubricant oil consumption has been attributed to the ring-pack dynamics.

In this dissertation, a reliable tool has been developed using MATLAB/SIMULINK and embedded C-S Functions that predicts the intricate …

Querying And Managing Opm-Compliant Scientific Workflow Provenance, Chunhyeok Lim

Wayne State University Dissertations

Provenance, the metadata that records the derivation history of scientific results, is important in scientific workflows to interpret, validate, and analyze the result of scientific computing. Recently,

to promote and facilitate interoperability among heterogeneous provenance systems, the Open Provenance Model (OPM) has been proposed and has played an important role in the community.

In this dissertation, to efficiently query and manage OPM-compliant provenance, we first propose a provenance collection framework that collects both prospective provenance, which captures

an abstract workflow specification as a recipe for future data derivation and retrospective provenance, which captures past workflow execution and data derivation information. …

Remote Software Upload Techniques In Future Vehicles And Their Performance Analysis, Irina Hossain

Wayne State University Dissertations

Updating software in vehicle Electronic Control Units (ECUs) will become a mandatory requirement for a variety of reasons, for examples, to update/fix functionality of an existing system, add new functionality, remove software bugs and to cope up with ITS infrastructure. Software modules of advanced vehicles can be updated using Remote Software Upload (RSU) technique. The RSU employs infrastructure-based wireless communication technique where the software supplier sends the software to the targeted vehicle via a roadside Base Station (BS). However, security is critically important in RSU to avoid any disasters due to malfunctions of the vehicle or to protect the proprietary …

Spray Characterization Of Flex-Fuel Gasoline Di Injectors And Spray Interaction With Charge Motion In A Variable Valve Actuation Engine, Atsushi Matsumoto

Wayne State University Dissertations

The objective of this study is to understand the characteristics of GDI sprays and behavior of in-cylinder charge motion in a GDI engine which is equipped with variable valve actuation. High speed spray visualization in a spray chamber was conducted for a study of spray development. By Schlieren visualization technique, the effect of different conditions including ambient conditions (temperature, pressure) and injection conditions (fuel type, fuel temperature, nozzle design) on spray formation was discussed in both qualitative and quantitative methods. High-speed visualization of the in-cylinder charge motion was carried out as well using an optical accessible engine. The testing was …

Linear And Non-Linear Deformations Of A Wind Turbine Blade Considering Warping And All Aeroelastic Load Couplings, Fouad Mohammad Mohammad

Wayne State University Dissertations

The structural dynamics behavior of the blade of a horizontal axis wind turbine that reacts to the different components of the aerodynamic loading were studied by many researchers using different approaches and assumptions. In the present research, the author considered all the extensional, torsional and flexural loadings acting on the blade with their couplings, variable airfoil cross sections with warping effects, shear deflection, rotary inertia and with or without blade's pretwist for both the linear small deformation case and the nonlinear large deformation case. To the best knowledge of the author the simultaneous inclusion of all these factors has not …

Multi-Fuel Operation Of Modern Engines; On Board Fuel Identification, Florin Mocanu

Wayne State University Dissertations

Modern engines require enhancement of electronic controls to achieve better fuel economy, higher power density and satisfactory emissions levels while operating safely.

Military vehicles should be capable to run safely and efficiently on any fuel available in the field, therefore on-board fuel identification and adaptation of engine controls to the type of fuel becomes extremely important. In these conditions, the use of an inexpensive, nonintrusive sensor is highly desirable.

The development of a technique based on the measurement of the instantaneous crankshaft speed and engine dynamics could be a convenient solution.

Several such methods have been elaborated at the Center …

An Integrated Framework For Freight Forwarders:Exploitation Of Dynamic Information For Multimodal Transportation, Farshid Azadian

Wayne State University Dissertations

Advent of real-time information broadcasting technologies, growth in demand for air-cargo, and increased congestion and variability on air-road network, are the main forces compelling today's air-freight forwarders to improve their operational decision-making to be more competitive and responsive to needs of customers. This research studies the air-cargo transportation on both road (short-haul) and air (long haul) network from the perspective of a mid-size freight forwarder.

We develop a routing algorithm for congestion avoidance on air-network based on historical data and introduce an innovative approach to incorporate real-time information to enable dynamic routing of cargo on a stochastic air-network. In the …

Optical Investigation Of Ethanol And N-Heptane Dual-Fuel Partially Premixed Combution In S Reciprocating Engine, Radu Catalin Florea

Wayne State University Dissertations

The details of the dual-fuel combustion of n-heptane and ethanol were investigated in an optically accessible engine representative of light-duty applications. Experimental work involved the application of optical diagnostics such as high-speed imaging of combustion chemiluminescence and soot radiation, spectral measurements and laser induced fluorescence. At the same time, the experimental conditions have been replicated using numerical simulation of chemically reactive in-cylinder flow.

The numerical simulation results, which showed good agreement with the experimental data across several validation approaches, provided an improved understanding of the mechanism responsible for the control of the rate of combustion for dual-fuel operation. The comparison …

Enhancing The Mechanical Properties Of A Hydroxyapatite-Collagen Bone Surrogate, Richard Franz Banglmaier

Wayne State University Dissertations

The synthesis of biomimetic hydroxyapatite-collagen composites is desirable from the perspective of graft elimination and load-bearing support when treating damaged or diseased bone. Bone is an organized network of carbonated hydroxyapatite mineralized collagen, whose strength and toughness is dependent on the organized array of mineralized collagen fibers that align with applied physiologic stresses. The apatitic calcium phosphate phase, hydroxyapatite, is promising for the biomimetic mineralization of collagen. Hydroxyapatite-collagen composites are osteoconductive and resorbable. However, the mechanical properties of these composites are one or more orders of magnitude less than bone. The aim of this study was to produce a bone-like …

A Multi-Agent Intelligent System For Detecting Unknown Adverse Drug Reactions Through Communication And Collaboration, Ayman Mohammad Mansour

Wayne State University Dissertations

Several thousands of drugs are currently available on the U.S. market. A complete understanding of the safe use of drugs is not possible at the time when drug is developed or marketed. At that time, the safety information is only obtained from a few thousand people in a typical pre-marketing clinical trial. Clinical trials are not capable of detecting rare adverse drug reactions (ADRs) because of limitations in sample size and trial duration. Early detection of unknown ADRs could save lives and prevent unnecessary hospitalizations. Current methods largely rely on spontaneous reports which suffer from serious underreporting, latency, and inconsistent …

Rethinking The Design And Implementation Of The I/O Software Stack For High-Performance Computing, Xuechen Zhang

Wayne State University Dissertations

Current I/O stack for high-performance computing is composed of multiple software layers in order to hide users from complexity of I/O performance optimization. However, the design and implementation of a specific layer is usually carried out separately with limited consideration of its impact on other layers, which could result in suboptimal I/O performance because data access locality is weakened, if not lost, on hard disk, a widely used storage medium in high-end storage systems.

In this dissertation, we experimentally demonstrated such issues in four different layers, including operating system process management layer and MPI-IO middleware layer on compute server side, …

Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner

Wayne State University Dissertations

Robotics and sensor technology have made impressive advancements over the years. There are now robotic systems that help perform surgeries or explore the surface of Mars, and there are sensors that detect trace amounts of explosives or identify diseased human tissue. The most powerful systems integrate robots and sensors, which are natural complements to each other. Sensors can provide information that might otherwise be unavailable due to indirect robotic manipulation (e.g., images of the target environment), and robots can provide suitably precise positioning of an analytical sensor.

To have an effective sensor-integrated robotic system, multiple capabilities are needed in the …