Mechanical Engineering Commons^™

Analysis Of Space-Charge-Limited Conduction Mechanisms In Zron/Sic System, Hasnurashid Nur Hasdyanna

Student Works (2020-2029)

In this study, current conduction mechanism by space-charge-limited conduction (SCLC) and Poole-Frenkel (PF) emission on ZrON/SiC system that was oxidized and nitrided in N2O at various temperatures (400-900˚C) were analysed. The current-voltage (I-V) measurements were performed in Al-gate metal-oxide-semiconductor (MOS) capacitor by sputtering of Al film on top of the film and at the back of the substrate. Then, characterization of electrical properties was done according to two types of bulk-limited conduction, which are space-charge-limited conduction and Poole-Frenkel emission conduction. Space-charge-limited conduction and Poole-Frenkel emission have been systematically evaluated through data analysis method by the fitting of linear regression according …

Large-Stroke Capacitive Mems Accelerometer Without Pull-In, Meysam Daeichin, Ronald Miles, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

In this study, the feasibility of obtaining electrical read-out data from a capacitive MEMS accelerometer that employs repulsive electrode configuration is demonstrated. This configuration allows for large-stroke vibrations of microstructures without suffering from pull-in failure that exists in conventional accelerometers based on the parallelplate configuration. With initial fabrication gap of 2:75um, the accelerometer can reach a 4:2um dynamical displacement amplitude. The accelerometer is tested up to 95(V) without exhibiting pull-in failure. For comparison, the pull-in voltage of an accelerometer with same dimensions but with conventional parallel-plate electrode configuration is 0:8(V). The MEMS device is fabricated using the POLYMUMPs fabrication standard. …

Me-Em Enewsbrief, September 2020, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Determining The Severity Of Obstructive Sleep Apnea (Osa) By Using Numerical Analysis, Ming Lok Ang

Student Works (2020-2029)

Computational technologies and biomechanical theories have been applied to study upper airway mechanics in obstructive sleep apnea (OSA). In this study, the patient is selected from ENT Department, UMMC, diagnosed with mild to severe OSA. In addition, the patient underwent maxillomandibular advancement (MMA) surgical treatment. Therefore, 3-dimensional modeling software will be used to model the upper airway, based on patient specific geometrical characteristics obtained from medical imaging and computed tomography (CT). Hence, providing an accurate assessment of airflow characteristics. Computational fluid dynamics (CFD) analysis will be combined with upper airway geometries obtained before and after surgical to determine the effects …

Trap-Assisted Tunneling Mechanism Of Zirconium Oxynitride (Zron) Thin Film On Silicon Carbide, Krishnamoorthy Nicklaane

Student Works (2020-2029)

This research is a study on the possibilities of trap-assisted tunneling conduction mechanism in Zirconium Oxynitride (ZrON) after Zirconium (Zr) with thickness 5nm was sputtered on Silicon Carbide (SiC) substrate which then underwent simultaneous nitridation and oxidation in Nitrous Oxide (N2O) for 15 minutes in 4 different ambient temperatures of 400°C, 500°C, 700⁰C, 900°C. Electrical properties of the samples were then characterized by fabricating Al-gate MOS capacitors onto the film surface. Of all 4 samples, sample that was oxidized/nitrided at 500°C demonstrated to have the highest dielectric breakdown (EB) of 5.05 MV/cm and lowest EB was by sample that was …

Investigation Of Space-Charge-Limited Conduction Mechanisms In Fe3o4-Y-Fe2o3 Based On Sio2/N-Type Si Substrate, Nik Zumaihan Nik Nadia Aina

Student Works (2020-2029)

In this work, thin films of functionalized Fe3O4-γ-Fe2O3 NPs deposited on n-type Si substrate was formed by self-assembly. The co-precipitation method was involved to synthesis the bare iron oxide NPs and the particles were altered to optimum pH 12 by using NH4OH. Iron oxide NPs were then undergone modification process with addition of 0.4 g oleic acid and 1.63 mmol functionalization 4-pentynoic acid. For electrical characterization of self-assembled 4-pentynoic acid functionalized Fe3O4-γ-Fe2O3 NPs on SiO2/n-Si substrate, the charge conduction mechanisms were quantitatively investigated and analyzed through the oxides for different heat treatment temperatures (70-300oC). In this study, the Ohm’s Law …

Social Enterprise And Sustainability: Key Factors That Lead To The Successful Establishment Of Sustainable Development Initiatives In Ireland, Gerard Doyle

Doctoral

International research points to the positive impact that social enterprises with an environmental focus (also referred to as sustainable development initiatives) perform in the transition to low carbon societies. This thesis examines the capacities required for the establishment and maintenance of sustainable development initiatives in Ireland. The thesis is based on five pieces of research which are either published in international peer-reviewed publications or of a publishable standard. One of the published pieces provides an explanatory framework addressing the reasons why the social enterprise sector in Ireland is less developed than in a number of European countries, details a number …

Open-Source Grinding Machine For Compression Screw Manufacturing, Jacob Franz, Joshua M. Pearce

Michigan Tech Publications, Part 1

Some of the most promising distributed recycling and additive manufacturing (DRAM) technical systems use fused particle fabrication (FPF) or fused granular fabrication (FGF), where compression screws force post-consumer waste plastic through a heated nozzle for direct 3D printing. To assist the technical evolution of these systems, this study provided the details of an invention for a low-cost, easily replicable open-source grinding machine for compression screw manufacturing. The system itself can be largely fabricated using FPF/FGF following the self-replicating rapid prototyper (RepRap) methodology. This grinding machine can be made from a cordless cut-off grinder and < $155 in parts. The new invention is demonstrated to be able to cut custom screws with variable (i) channel depths, (ii) screw diameters, (iii) screw lengths, (iv) pitches, (v) abrasive disk thicknesses, (vi) handedness of the screws, (vii) and materials (three types of steel tested: 1045 steel, 1144 steel, and 416 stainless steel). The results show that the device is more than capable of replicating commercial screws as well as providing makers with a much greater flexibility to make custom screws. This invention enables the DRAM toolchain to become even more self-sufficient, which assists the goals of the circular economy.

Gradient-Based Optimization Of Solar-Regenerative High-Altitude Long-Endurance Aircraft, Taylor Mcdonnell, Andrew Ning

Faculty Publications

This paper uses gradient-based optimization to minimize the mass of a solar-regenerative high-altitude long-endurance (SR-HALE) flying-wing aircraft while accounting for nonlinear aeroelastic effects. The aircraft is designed to fly year round at 35° latitude at 18 km above sea level and subjected to energy capture, energy storage, material failure, local buckling, stall, longitudinal stability, and coupled flight and aeroelastic stability constraints. The optimized aircraft has an aspect ratio of 54.52, a surface area of 73.56 m2 , a mass of 349.5 kg, exhibits little aeroelastic deflection at the design airspeed, and is primarily stability constrained. Several parameter sweeps are performed …

Experimental Demonstration Of Heat Loss And Turn-Down Ratio For A Multi-Panel, Actively Deployed Radiator, Rydge B. Mulford, Samuel D. Salt, Lance P. Hyatt, Kyle S. Meaker, Vivek H. Dwivedi, Matthew R. Jones, Brian D. Iverson

Faculty Publications

Origami-inspired, dynamic spacecraft radiators have been proposed which utilize an expandable/collapsible surface capable of large variations in emitting surface area. In this work, an experimental prototype of this concept is realized and its performance is analyzed. In particular, we demonstrate the capability of maintaining a spacecraft component at a desired operating temperature through the expansion and contraction of a collapsible radiator to control radiative heat loss. Four aluminum panels are connected via a flexible hinge constructed from interwoven copper wires and suspended from an actuating framework. The radiator panels are connected to a heated aluminum block. The radiator is placed …

Resonant Triad Interactions In One And Two-Layer Systems, Malik Chabane

Dissertations

This dissertation is a study of the weakly nonlinear resonant interactions of a triad of gravity-capillary waves in systems of one and two fluid layers of arbitrary depth, in one and two-dimentions. For one-layer systems, resonant triad interactions of gravity-capillary waves are considered and a region where resonant triads can be always found is identified, in the two-dimensional wavevector angles-space. Then a description of the variations of resonant wavenumbers and wave frequencies over the resonance region is given. The amplitude equations correct to second order in wave slope are used to investigate special resonant triads that, providing their initial amplitude …

Numerical Study Of Paraffin Wax Melting In A Cavity With A Gradient Of Hot Wall Inclination, Agus Dwi Korawan

Makara Journal of Technology

The melting of a phase change material (PCM) in a cavity with a gradient of hot wall inclination was simulated numerically using five models, namely, Model-A, Model-B, Model-C, Model-D, and Model-E with gradients of −2, −4, ∞, 4, and 2, respectively. The PCM was paraffin wax, which was melted using an enthalpy porosity technique with a pressure-based method. Model-A was found to be the best model. For the completion of the melting process, the models were assigned with the liquid fraction of 1. Model-A required the shortest time, followed by Model-B, Model-C, Model-E, and Model-D, respectively. Compared with Model-C, Model-A …

The Effect Of Adsorbed Volatile Organic Compounds On An Ultrathin Water Film Measurement, Shahab Bayani Ahangar, Chan Ho Jeong, Fei Long, Jeffrey S. Allen, Seong Hyuk Lee, Chang Kyoung Choi

Michigan Tech Publications, Part 1

Using surface plasmon resonance imaging (SPRi), we have recently shown for the first time the existence of a monolayer water film between droplets during dropwise condensation. This study examines the effect of adsorbed volatile organic compounds (VOCs) on the ultrathin film measurement using SPRi. Further, the work presents the proper surface-treatment process that enables measurements of the ultrathin water layer during high-speed imaging of dropwise condensation at 3000 frame per second. In this study, two methods were applied for cleaning the surface (gold-coated glass)-(1) standard cleaning procedure (SCP) using acetone, isopropyl alcohol, and deionized water and (2) SCP followed by …

Applying Clustering To Optimize Markovian Models In Human-Machine Interactions, Griffon Mcmahon

The Journal of Purdue Undergraduate Research

No abstract provided.

Quantifying Changes In Muscle Force In The Presence Of Fatigue, Emily Bywater

The Journal of Purdue Undergraduate Research

No abstract provided.

Large-Scale Flow In Micro Electrokinetic Turbulent Mixer, Keyi Nan, Zhongyan Hu, Wei Zhao, Kaige Wang, Jintao Bai, Guiren Wang

Faculty Publications

In the present work, we studied the three-dimensional (3D) mean flow field in a micro electrokinetic (μEK) turbulence based micromixer by micro particle imaging velocimetry (μPIV) with stereoscopic method. A large-scale solenoid-type 3D mean flow field has been observed. The extraordinarily fast mixing process of the μEK turbulent mixer can be primarily attributed to two steps. First, under the strong velocity fluctuations generated by μEK mechanism, the two fluids with different conductivity are highly mixed near the entrance, primarily at the low electric conductivity sides and bias to the bottom wall. Then, the well-mixed fluid in the local region convects …

Bioprinted In Vitro Model Of Human Glioblastoma, Rachel Lauren Schwartz

Theses and Dissertations

Glioblastoma multiform (GBM) is one of the most aggressive forms of primary brain tumors. GBM is fast progressing and resistant to treatment, resulting in a low survival rate. Conventional 2-dimensional tissue culture models cannot fully replicate the complexities of cancer lesions that contain multiple cell types and structures (e.g. vessels composed of endothelial cells, cancer cells, normal cells, etc.) as well as an intricate scaffold of proteins comprising the extracellular matrix (ECM). In addition, animal models cannot translate into the clinical disease in patients. Thus, this study has developed a bioprintable organ-on-a-chip (OOAC) model that mimics the important ECM factors …

Thermal Control Development Of A Proton Exchange Membrane Fuel Cell System, Ola Mohammed Taha Al-Shalash

Mechanical Engineering Theses

A fuel cell is an electrochemical energy conversion device that uses fuel to generate electricity. It basically converts the chemical energy of reactants directly into electricity without combustion. In a Proton Exchange Membrane Fuel Cell (PEMFC), the reactants, hydrogen and oxygen, are fed into the two electrodes, anode and cathode, respectively. A reaction takes place at each electrode and produces electricity, as well as water, and heat as the by-products. In order to maximize performance of a fuel cell, many factors can be considered for tuning and control. Temperature management is one of these factors.

A thermal-fluid model of a …

Multidirectional Cylindrical Piezoelectric Force Sensor: Design And Experimental Validation, Ye Rim Lee, Justin Neubauer, Kwang Jin Kim, Youngsu Cha

Mechanical Engineering Faculty Research

A common design concept of the piezoelectric force sensor, which is to assemble a bump structure from a flat or fine columnar piezoelectric structure or to use a specific type of electrode, is quite limited. In this paper, we propose a new design of cylindrical piezoelectric sensors that can detect multidirectional forces. The proposed sensor consists of four row and four column sensors. The design of the sensor was investigated by the finite element method. The response of the sensor to various force directions was observed, and it was demonstrated that the direction of the force applied to the sensor …

Dynamics Analysis Of Misalignment And Stator Short-Circuit Coupling Fault In Electric Vehicle Range Extender, Xiaowei Xu, Jingyi Feng, Nan Zhang, Xiaoqing Wang

Research, Publications & Creative Work

Due to the complex structure and wide excitation of the range extender, the misalignment and stator short-circuit coupling fault can easily occur. Therefore, it is necessary to study the coupling fault mechanism of the range extender, analyze the cause of the fault and the fault evolution law, and research the coupling fault characteristics. To reveal the mechanism of misalignment and stator-short-circuit coupling fault, the misalignment mechanism was analyzed and the bending and torsion electromagnetic stiness of the generator in the stator short-circuit fault was derived. Then the dynamic model of bending and torsion coupling for the generator was established. Furthermore, …

Mimicking Blood Rheology For More Accurate Modeling In Benchtop Research, Lindsey Webb

The Pegasus Review: UCF Undergraduate Research Journal

Because blood is challenging to use as a working fluid in a laboratory setting due to health and safety concerns, a blood analogue would be useful to perform benchtop experiments. Viscosity is an important fluid property for modeling and experiments, especially because blood is a shear thinning fluid; therefore, it has a decreasing viscosity with higher shear rates. This project seeks to create a blood-mimicking fluid for benchtop laboratory use. Numerous fluids with different combinations of water, glycerin, salt, and xanthan gum (XG) were created to mimic blood viscosity at different hematocrit levels. Four additional solutions were also created from …

Ventilation & Masks: Reducing Airborne Transmission Of Covid-19 In A Classroom, Eric A. Schiff

SyracuseCoE

We've calculated the number of COVID-19 infections that will be spread from a single COVID-19 "superspreader" to students and teachers in a classroom shared for 4 hours in different ventilation and masking conditions.

Feasibility Study On Environmental Protection Reform Of Ship Stern Tube System Based On Water Lubrication, Yang Cui

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Dr. Cesmeci Awarded DOE Grant

Methodologies For Improvement Of Metal Fatigue Life, Ali Haghshenas

LSU Doctoral Dissertations

A methodology is proposed to identify the onset of crack initiation that utilizes the material damping. The damping is measured using the impulse excitation technique (IET). The damping is also used to correlate fatigue life of additively manufactured (AM) specimens to their damping characteristics. Results reveal that the damping value is inversely proportional to the fatigue life of the specimens.

To detect the damage accumulation and crack initiation in metals due to cyclic loading, another methodology based on the measurement of the surface roughness parameters is introduced. Results presented reveal that the evolution of the surface roughness parameters can be …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Dr. M. Xu Receives Faculty Award from AIST

Measured Cooling Energy Savings From Reflective Wall Finishes: Evaluation As An Efficiency Measure Across Climates, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

In past research, reflective roofs have shown significant potential to reduce cooling in buildings. However, there have been few empirical evaluations of cooling reductions from changing wall reflectance. In the reported study, several experiments with instrumented scale test buildings are used to provide validation for a detailed simulation analysis across varied North American climates. The simulations establish the potential of reflective walls as an efficiency measure in existing buildings against climate.

This paper was published in the 2020 ACEEE Summer Study on Energy Efficiency in Buildings.

Who's Leading: The Dance Between Mini-Splits And Existing Hvac Systems, Florida Solar Energy Center, Cheryn Metzger

FSEC Energy Research Center®

Recently, many utilities across the U.S. have provided incentives for ductless mini-split heat pumps due to their relatively high efficiencies. However, when these ductless mini-splits are installed in existing homes, utilities and researchers find that they are not living up to their energy saving potential, due to a lack of coordinated controls with the existing HVAC system. The Pacific Northwest National Laboratory (PNNL), the Florida Solar Energy Center (FSEC), and The Levy Partnership are all leading projects across the country to address this problem. The goal for this body of work is to determine which control strategies provide the most …

Targeting The Best Performing Home Efficiency Programs With Advanced Metering Evaluation Supplemented By Simulation, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

The authors investigated the impacts of seven residential rebate energy efficiency programs offered by a municipal utility. The evaluation examined energy use pre and post retrofit using the Advanced Metering Infrastructure (AMI) data, disaggregated by major end-use and weather-adjusted; and also by detailed simulations. Residences modeled were representative of typical participants for that measure based on factors such as year built, conditioned square feet and number of bedrooms.

Our analysis found the residential rebate programs to be of highly varied effectiveness, but important differences surfaced between the simulation and the AMI data evaluation. Not surprisingly, programs with larger samples tended …

Analysis Techniques For Evaluating Energy Conservation Programs Using Utility Ami Data, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

With the evolution of Advanced Metering Infrastructure (AMI) electric meters, utility companies now have direct access to whole building electricity use at a granular time scale. AMI data can be used for a variety of purposes beyond billing, for example, to evaluate the efficacy of energy conservation (EC) programs. Historical methods for calculating EC program savings include building simulation models and laboratory and/or field testing. With big data now available, which analysis methods are more likely to yield quality results?

In a recent project, the Orlando Utility Commission provided monitored AMI data from Oct 1, 2015 - Sep 27, 2018 …