Mechanical Engineering Commons^™

Ultrahigh Sensitivity Of Methylammonium Lead Tribromide Perovskite Single Crystals To Environmental Gases, Hong-Hua Fang, Sampson Adjokatse, Haotong Wei, Jie Yang, Graeme R. Blake, Jinsong Huang, Jacky Even, Maria Antonietta Loi

Department of Mechanical and Materials Engineering: Faculty Publications

One of the limiting factors to high device performance in photovoltaics is the presence of surface traps. Hence, the understanding and control of carrier recombination at the surface of organic-inorganic hybrid perovskite is critical for the design and optimization of devices with this material as the active layer. We demonstrate that the surface recombination rate (or surface trap state density) inmethylammonium lead tribromide (MAPbBr3) single crystals can be fully and reversibly controlled by the physisorption of oxygen and water molecules, leading to a modulation of the photoluminescence intensity by over two orders of magnitude.We report an unusually low surface recombination …

Pulsed Laser Cutting Of Magnesium-Calcium For Biodegradable Stents, M. P. Sealy, Y. B. Guo, J. F. Liu, C. Li

Department of Mechanical and Materials Engineering: Faculty Publications

There is growing interests in the use of biodegradable magnesium implants for cardiovascular and pulmonary applications such as stents. Magnesium is a metal that has the ability to gradually dissolve and absorb into the human body after implantation. There is very little work discussing the relationship between process parameters and cut quality of magnesium stents by laser cutting. The objective of this research is to determine the effect of laser cutting conditions including peak laser power and cutting speed of a millisecond range pulsed laser on kerf geometry, surface topography, surface roughness, and microstructure. An assessment on the experimental work …

Impact Of Patient Factors On Operative Duration During Laparoscopic Cholecystectomy: Evaluation From The National Surgical Quality Improvement Program Database, Bethany Rose Lowndes, Cornelius A. Thiels, Elizabeth B. Habermann, Juliane Bingener, M. Susan Hallbeck, Denny Yu

Department of Mechanical and Materials Engineering: Faculty Publications

BACKGROUND: Patient factors impact laparoscopic cholecystectomy (LC) difficulty, specifically operative duration. This study quantifies the impact of patient factors on LC duration.

METHODS: The national surgery database (American College of Surgeons National Surgical Quality Improvement Program) was reviewed for all elective LC for biliary colic from 2005 to 2013. Multivariate general linear model and logistic regression were used to evaluate patient factors as predictors of operative duration greater than 60 minutes, adjusted for resident involvement and cholangiography.

RESULTS: A total of 24,099 LC met inclusion criteria. Regression analysis found procedure duration greater than 60 minutes was less likely for patients …

A Comparative Study On Machining Capabilities Of Wet And Dry Nanoscale Electro-Machining, Muhammad P. Jahan, Kamlakar P. Rajurkar, Ajay P. Malshe

Department of Mechanical and Materials Engineering: Faculty Publications

Presently, the nano scale electro-machining (nano-EM) process has been demonstrated in both the liquid and air dielectric mediums, which are known as wet and dry nano-EM respectively. In the current study, two important aspects of the nano-EM have been investigated: the minimum possible feature dimension and mass fabrication capability of nano-EM. Firstly, the investigation has been done on the capability of machining graphene at atomic scale with focus on obtaining smallest possible nano-feature using the wet nano-EM. Secondly, the ability of the nano-EM process for the fabrication of arrays of nano-holes has been investigated using dry nano-EM. It was found …

Bioink Properties Before, During And After 3d Bioprinting, Katja Holzl, Shengmao Lin, Liesbeth Tytgat, Sandra Van Vlierberghe, Linxia Gu, Aleksandr Ovsianikov

Department of Mechanical and Materials Engineering: Faculty Publications

Bioprinting is a process based on additive manufacturing from materials containing living cells. These materials, often referred to as bioink, are based on cytocompatible hydrogel precursor formulations, which gel in a manner compatible with different bioprinting approaches. The bioink properties before, during and after gelation are essential for its printability, comprising such features as achievable structural resolution, shape fidelity and cell survival. However, it is the final properties of the matured bioprinted tissue construct that are crucial for the end application. During tissue formation these properties are influenced by the amount of cells present in the construct, their proliferation, migration …

Development Of A Synthetic Gene Network To Modulate Gene Expression By Mechanical Forces, Zoltan Kis, Tania Rodin, Asma Zafar, Zhangxing Lai, Grace Freke, Oliver Fleck, Armando Del Rio Hernandez, Leila Towhidi, Ryan M. Pedrigi, Takayuki Homma, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The majority of (mammalian) cells in our body are sensitive to mechanical forces, but little work has been done to develop assays to monitor mechanosensor activity. Furthermore, it is currently impossible to use mechanosensor activity to drive gene expression. To address these needs, we developed the first mammalian mechanosensitive synthetic gene network to monitor endothelial cell shear stress levels and directly modulate expression of an atheroprotective transcription factor by shear stress. The technique is highly modular, easily scalable and allows graded control of gene expression by mechanical stimuli in hard-to-transfect mammalian cells. We call this new approach mechanosyngenetics. To insert …

Portable Camera Aided Simulator (Portcas) For Minimally Invasive Surgical Training, Ka-Chun Sui, Carl Nelson, Mohsen Zahiri, Dmitry Oleynikov

Department of Mechanical and Materials Engineering: Faculty Publications

The present disclosure is directed to a system and method for surgical training with low cost, reusable materials and a highly customizable virtual environment for skill-building. According to various embodiments, a surgical training tool is usable in conjunction with a support structure configured to at least partially constrain the tool movement. Meanwhile, the tool is tracked in real-time with off-tool detectors to generate a tool path driving a virtual rendering of the surgical training tool in an operative environment. The virtual rendering may be visually observable via a display device and may include a customizable and/or selectable operative environment with …

Secondary Pool Boiling Effects, C. Kruse, A. Tsubaki, C. A. Zuhlke, T. P. Anderson, Dennis R. Alexander, George Gogos, Sidy Ndao

Department of Mechanical and Materials Engineering: Faculty Publications

A pool boiling phenomenon referred to as secondary boiling effects is discussed. Based on the experimental trends, a mechanism is proposed that identifies the parameters that lead to this phenomenon. Secondary boiling effects refer to a distinct decrease in the wall superheat temperature near the critical heat flux due to a significant increase in the heat transfer coefficient. Recent pool boiling heat transfer experiments using femtosecond laser processed Inconel, stainless steel, and copper multiscale surfaces consistently displayed secondary boiling effects, which were found to be a result of both temperature drop along the microstructures and nucleation characteristic length scales. The …

Experimental Explanation Of The Formation Mechanism Of Surface Mound-Structures By Femtosecond Laser On Polycrystalline Ni60Nb40, Edwin Peng, A. Tsubaki, Craig A. Zuhlke, Meiyu Wang, Ryan Bell, Michael J. Lucis, Troy P. Anderson, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Femtosecond laser surface processing (FLSP) is an emerging technique for creating functionalized surfaces with specialized properties, such as broadband optical absorption or superhydrophobicity/ superhydrophilicity. It has been demonstrated in the past that FLSP can be used to form two distinct classes of mound-like, self-organized micro/nanostructures on the surfaces of various metals. Here, the formation mechanisms of below surface growth (BSG) and above surface growth (ASG) mounds on polycrystalline Ni₆₀Nb₄₀ are studied. Cross-sectional imaging of these mounds by focused ion beam milling and subsequent scanning electron microscopy revealed evidence of the unique formation processes for each class of …

Analytical Solution For Speed To Achieve A Desired Operating Point For A Given Fan Or Pump, Michael F. Kocher, Jeyamkondan Subbiah

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Affinity Laws for fans (and pumps) provide a way of determining new fan or pump speed given fan or pump performance curve data and a desired operating point (combination of flow rate and pressure) that does not fall on the curve. However, the affinity law calculations require using a point on the curve (hereafter referred to as the “basic point”) to determine the new speed. Most references regarding the Affinity Laws do not give a clear description of the method for determining the “basic point”, and improper selection of this point can affect the results considerably. This article describes …

In-Field Fuel Use And Load States Of Agricultural Field Machinery, Santosh Pitla, Joe D. Luck, Jared Werner, Nannan Lin, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The ability to define in-field tractor load states offers the potential to better specify and characterize fuel consumption rate for various field operations. For the same field operation, the tractor experiences diverse load demands and corresponding fuel use rates as it maneuvers through straight passes, turns, suspended operation for adjustments, repair and maintenance, and biomass or other material transfer operations. It is challenging to determine the actual fuel rate and load states of agricultural machinery using force prediction models, and hence, some form of in-field data acquisition capability is required. Controller Area Networks (CAN) available on the current model tractors …

Inter-Row Robot Navigation Using 1d Ranging Sensors, Tyler A. Troyer, Santosh Pitla, Ethan Nutter

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In this paper a fuzzy logic navigation controller for an inter-row agricultural robot is developed and evaluated in laboratory settings. The controller receives input from one-dimensional (1D) ranging sensors on the robotic platform, and operated on ten fuzzy rules for basic row-following behavior. The control system was implemented on basic hardware for proof of concept and operated on a commonly available microcontroller development platform and open source software libraries. The robot platform used for experimentation was a small tracked vehicle with differential steering control. Fuzzy inferencing and defuzzification, step response and cross track error were obtained from the test conducted …

Tractor Hydraulic Power Data Acquisition System, J. B.W. Roeber, Santosh Pitla, Michael F. Kocher, Joe D. Luck, Roger M. Hoy

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Tractor hydraulic power is used on a wide range of agricultural implements; however, the availability of operational hydraulic data at points other than full engine throttle position is limited. Operators could utilize this hydraulic data to maximize field efficiency and minimize machinery costs when determining suitable machinery for field operations. A field usable hydraulic test apparatus capable of measuring tractor hydraulic pressure and flow rate data was developed. The goal of this study was to determine if a hydraulic flow and pressure measurement device could be installed on the rear of a tractor to provide implement hydraulic power consumption at …

Comparing Various Hardware/Software Solutions And Conversion Methods For Controller Area Network (Can) Bus Data Collection, Samuel E. Marx, Joe D. Luck, Santosh Pitla, Roger M. Hoy

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Various hardware and software solutions exist for collecting Controller Area Network (CAN) bus data. Digital data accuracy could vary based upon different data logging methods (e.g., hardware/software timing, processor timing, etc.). CAN bus data were collected from agricultural tractors using multiple data acquisition solutions to quantify differences among collection methods and demonstrate potential data accumulation rates. Two types of data were observed for this study. The first, CAN bus frame data, represents data collected for each line of hex data sent from an ECU. One issue with frame data is the resulting large file sizes, therefore a second logging format …

A Comprehensive Model Of The Transport Phenomena In Gas Metal Arc Welding, Junling Hu, Zhenghua Rao, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A comprehensive two-dimensional gas metal arc welding (GMAW) model was developed to take into account all the interactive events in the gas metal arc welding process, including the arc plasma, melting of the electrode, droplet formation, detachment, transfer, and impingement onto the workpiece, and the weld-pool dynamics and weld formation. The comprehensive GMAW model tracks the free surface using the volume of fluid method and directly modeled the coupling effects between the arc domain and the metal domain, thus eliminating the need to assign boundary conditions at the interface. A thorough investigation of the plasma arc characteristics was conducted to …

Optimal Switch Timing For Piezoelectric-Based Semi-Active Vibration Reduction Techniques, Christopher Kelley

Electronic Theses and Dissertations

Semi-active vibration reduction techniques switch a piezoelectric transducer between an open circuit and a shunt circuit in a way that reduces vibration. The steady-state vibration amplitude is reduced by exploiting the change in stiffness between states, manipulating the converted electrical energy, or both. Semi-active techniques typically require four switches per vibration cycle. Control laws such as state switching and synchronized switch damping require switches to occur at every displacement extrema. Due to the complexity of analyzing a system with discrete switches, these control laws were developed based on intuition. The few analyses that attempt to determine an optimal switching law …

Regression Analysis Of Pem Fuel Cell Transient Response, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

To develop operating strategies in polymer electrolyte membrane (PEM) fuel cell-powered applications, precise computationally efficient models of the fuel cell stack voltage are required. Models are needed for all operating conditions, including transients. In this work, transient evolutions of voltage, in response to load changes, are modeled with a sum of three exponential decay functions. Amplitude factors are correlated to steady-state operating data (temperature, humidity, average current, resistance, and voltage). The obtained time constants reflect known processes of the membrane heat/water transport. These model parameters can form the basis for the prediction of voltage overshoot/undershoot used in computational-based control systems, …

Effect Of Poisson’S Ratio On Material Properties Characterization By Nanoindentation With A Cylindrical Flat Tip Indenter, Md Mehadi Hassan

Electronic Theses and Dissertations

Nano indentation technology is commonly used to determine the mechanical properties of different kinds of engineering materials. The young’s modulus of the materials can be calculated with the load depth data obtained from an indentation test with a known Poisson’s ratio. In this investigation the NANOVEA micro/nanoindentation tester with a cylindrical flat-tip indenter will be used to find the elastic modulus, hardness and Pile up. Low carbon steel AISI1018, alloy steel AISI 4340 and aluminum alloy 6061 were selected for the case study. Finite element (FE) analysis using axisymmetric 3-D models used to establish the relationship between Poisson’s ratio and …

Supersonic Combustion Ramjet: Analysis On Fuel Options, Stephanie Barone

Honors Theses

This report focuses on different fuel options available to use for scramjet engines. The advantages and disadvantages of JP-7, JP-8, and hydrogen fuels are covered, also the effectiveness and requirements for each fuel are discussed. The recent history of the scramjet engine is included as well as its advantages and disadvantages. An explanation of what each fuel option encompasses and engineering analysis for each fuel are shown. The equations presented for the parametric analysis are shown as functions of the freestream Mach number, with the combustion Mach number as a parameter. The results can be seen for the theoretical possibilities …

Real-Time Monitoring Of Personal Exposures To Carbon Dioxide, Elliott T. Gall, Toby Cheung, Irvan Luhung, Stefano Schiavon, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

Elevated indoor CO₂ levels are indicative of insufficient ventilation in occupied spaces and correlate with elevated concentrations of pollutants of indoor origin. Adverse health and well-being outcomes associated with elevated indoor CO₂ levels are based on CO₂ as a proxy, although some emerging evidence suggests CO₂ itself may impact human cognition. Using portable monitors, we conducted an exposure study with 16 subjects in Singapore to understand the levels, dynamics and influencing factors of personal exposure to CO₂. Participants carried a CO₂ monitor continuously for 7-day periods recording their exposure levels at 1-min intervals. …

Remote Sensing Of Neutron And Gamma Radiation Using Aerial Unmanned Autonomous System, Alex Barzilov, Jessica Hartman, Ivan Novikov

Graduate & Professional Student Association Research Forum

With the continuing advancement of nuclear technologies, the detection and identification of radioactive material is a necessary part of commercial and government applications. There is a wide array of options available for detection and identification of material, but most rely on compact devices which are manually positioned. The deployment of robots equipped with detection equipment is not always feasible, especially in locations where there is considerable debris on the ground, or where there are low clearance areas. To solve this, the goal of this research was to design a remote sensing system for radiation using unmanned aerial vehicles (UAVs). A …

The Effects Of Carbon Fiber Misalignment On Composite Material Strength, Luke Stangler

Electronic Theses and Dissertations

Nondestructive Evaluation (NDE) is an effective way for determining material properties. More specifically, ultrasonic waves along with visual measurements from a microscope can be used to systematically determine the elastic modulus of single ply composites that are subject to an altered manufacturing process. In this approach, the magnitude of specific ultrasonic wave velocities is applied through Chirstoffel's equations to determine the necessary five elastic constants that describe the elastic modulus of transversely isotropic composites. On the other hand, fiber misalignment measurements are taken through via digital microscopy to satisfy a statistical approach for the determination of the same elastic modulus. …

Nonlinear Vibration Energy Harvesting Based On Variable Double Well Potential Function, Wei Yang, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Converting ambient mechanical energy to electricity, vibration energy harvesting, enables powering of the low-power remote sensors. Nonlinear energy harvesters have the advantage of a wider frequency spectrum compared to linear resonators making them more efficient in scavenging the broadband frequency of ambient vibrations. To increase the output power of the nonlinear resonators, we propose an energy harvester composed of a cantilever piezoelectric beam carrying a movable magnet facing a fixed magnet at a distance. The movable magnet on the beam is attached to a spring at the base of the beam. The spring-magnet system on the cantilever beam creates the …

Magnetoelastic Beam With Extended Polymer For Low Frequency Vibration Energy Harvesting, Alwathiqbellah Ibrahim, Shahrzad Towfighian, Mohammad I. Younis, Quang Su

Mechanical Engineering Faculty Scholarship

Ambient energy in the form of mechanical kinetic energy is mostly considered waste energy. The process of scavenging and storing such energy is known as energy harvesting. Energy harvesting from mechanical vibration is performed using resonant energy harvesters (EH) with two major goals: enhancing the power scavenged at low frequency sources of vibrations, and increasing the efficiency of scavenging energy by increasing the bandwidth near the resonant frequency. Toward such goals, we propose a piezoelectric EH of a composite cantilever beam with a tip magnet facing another magnet at a distance. The composite cantilever consists of a piezoelectric bimorph with …

Development Of Learning Objectives For An Undergraduate Computer-Aided Drafting And Design Animation Using The Delphi Technique, Gavin M. Wilk

Masters Theses

This study reflects on learning objectives created for an advanced computer aided drafting (CAD) learning module(s) or course with the emphasis on simulation and engineering animations. These objectives were derived by using the Delphi technique by access the support of a panel of subject matter experts (SME) from academia and industry that are interested in CAD. The results of this study are intended for the use of creating instructional modules for undergraduate studies.

A panel of experts were chosen through an electronic listserv of engineering and technology supporters. Two rounds of two different Delphi survey instruments were utilized to complete …

Arbitrary Lagrangian-Eulerian Method Investigation On Fuel Tank Strap Simulation Under Proving Ground Condition, Guangtian Song

Wayne State University Dissertations

The Arbitrary Lagrangian-Eulerian (ALE) is a hybrid finite element formulation that can alleviate many of the drawbacks from the traditional Lagrangian-based and Eulerian-based finite element simulations, which is developed through combining modern algorithms for Lagrangian hydrodynamics, meshing technology and remap methods developed for high-resolution Eulerian methods. Lagrangian-based finite element formulations is that the computational system moves with the material and main drawback is that it will face severe problems to deal with strong distortions in the computational domain. Eulerian-based finite element formulations is that the computational system is a prior fixed in space and unable to deal easily with fluids …

Stop Identity Cues As A Cue To Language Identity, Paula Lisa Castonguay

Wayne State University Dissertations

The purpose of the present study was to determine whether language membership could potentially be cued by the acoustic-phonetic detail of word-initial stops and retained all the way through the process of lexical access to aid in language identification. Of particular interest were language-specific differences in CE and CF word-initial stops. Experiment 1 consisted of an interlingual homophone production task. The purpose of this study was to examine how word-initial stop consonants differ in terms of acoustic properties in Canadian English (CE) and Canadian French (CF) interlingual homophones. The analyses from the bilingual speakers in Experiment 1 indicate that bilinguals …

Development Of An Elderly Female Torso Finite Element Model For Restraint System Research And Development Applications, Anil Kalra Kalra

Wayne State University Dissertations

Elderly females are found to be one of the most vulnerable segments of population during motor vehicle crashes and their population is increasing in the coming decades. Current design of restraint systems as well as other passive safety measures are designed based on anthropomorphic details of younger population. Developing another dummy representing elderly female population is a costly effort, while a finite element (FE) model of elderly female with similar anthropomorphic details and age- and gender-specific material properties can be a better alternative solution. The current research focuses on the development of a FE model of an elderly female torso, …

Experimental Validation Data For Cfd Of Forced Convection On A Vertical Flat Plate, Jeff R. Harris, Blake W. Lance, Barton L. Smith

Mechanical and Aerospace Engineering Faculty Publications

A CFD validation data set for turbulent forced convection on a vertical plate is presented. The design of the apparatus is based on recent validation literature and provides a means to simultaneously measure boundary conditions and system response quantities. All important inflow quantities for RANS CFD are also measured. Data are acquired at two heating conditions and cover the range 40;000 < Rex < 300;000, 357 < Red2 < 813 and 0:02 < Gr/Re2 < 0:232. The data and uncertainties are contained in files in the supplemental material

Finite Element Analysis And Topology Optimization Of Differential Case And Control Arm For Static And Fatigue Loading, Pankaj N. Kalan

Dissertations, Master's Theses and Master's Reports

Optimization of the automobile components can result in a significant decrease in vehicle weight, increase in fuel efficiency and reduction in environmental damage. For example, the lightweight vehicle production will save over 4.4×109 GJ of energy and 4.1×108 tons of CO2 over a 10 year period, compared to the current non-light weight vehicles. This equates to 890 billion miles or 42 billion gallons of gas savings (Wu 2016). This study evaluates the weight reduction possible by using manual and automatic (using Optistruct software) topology optimization processes. Optimization of a vehicle differential case done in this study shows that a weight …