Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 42

Full-Text Articles in Mechanical Engineering

Radio Frequency Emissions From Dark-Matter-Candidate Magnetized Quark Nuggets Interacting With Matter, J. Pace Vandevender, C. Jerald Buchenauer, Chunpei Cai, Aaron P. Vandevender, Benjamin A. Ulmen Dec 2020

Radio Frequency Emissions From Dark-Matter-Candidate Magnetized Quark Nuggets Interacting With Matter, J. Pace Vandevender, C. Jerald Buchenauer, Chunpei Cai, Aaron P. Vandevender, Benjamin A. Ulmen

Michigan Tech Publications

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks. They are also called strangelets, nuclearites, AQNs, slets, Macros, and MQNs. Quark nuggets are a candidate for dark matter, which has been a mystery for decades despite constituting ~ 85% of the universe’s mass. Most previous models of quark nuggets have assumed no intrinsic magnetic field; however, Tatsumi found that quark nuggets may exist in magnetars as a ferromagnetic liquid with a magnetic field BS = 1012±1 T. We apply that result to quark nuggets, a dark-matter candidate consistent with the Standard Model, and ...


Power Take-Off And Energy Storage System Static Modeling And Sizing For Direct Drive Wave Energy Converter To Support Ocean Sensing Applications, Xiang Zhou, Ossama Abdelkhalik, Wayne Weaver Jul 2020

Power Take-Off And Energy Storage System Static Modeling And Sizing For Direct Drive Wave Energy Converter To Support Ocean Sensing Applications, Xiang Zhou, Ossama Abdelkhalik, Wayne Weaver

Michigan Tech Publications

This paper addresses the sizing and design problem of a permanent magnet electrical machine power take-off system for a two-body wave energy converter, which is designed to support ocean sensing applications with sustained power. The design is based upon ground truth ocean data bi-spectrums (swell and wind waves) from Martha’s Vineyard Coastal Observatory in the year 2015. According to the ground truth ocean data, the paper presents the optimal harvesting power time series of the whole year. The electrical machine and energy storage static modeling are introduced in the paper. The paper uses the ground truth ocean data in ...


Open-Source Digitally Replicable Lab-Grade Scales, Benjamin R. Hubbard, Joshua M. Pearce Jun 2020

Open-Source Digitally Replicable Lab-Grade Scales, Benjamin R. Hubbard, Joshua M. Pearce

Michigan Tech Publications

This study provides designs for a low-cost, easily replicable open-source lab-grade digital scale that can be used as a precision balance. The design is such that it can be manufactured for use in most labs throughout the world with open-source RepRap-class material extrusion-based 3-D printers for the mechanical components and readily available open-source electronics including the Arduino Nano. Several versions of the design were fabricated and tested for precision and accuracy for a range of load cells. The results showed the open-source scale was found to be repeatable within 0.05 g with multiple load cells, with even better precision ...


Investigation Of Deformation Induced Micro To Macro Scale Surface Roughness, Ayotunde Olayinka, William J. Emblom, Scott W. Wagner, Michael Khonsari, Ali Haghshenas Jun 2020

Investigation Of Deformation Induced Micro To Macro Scale Surface Roughness, Ayotunde Olayinka, William J. Emblom, Scott W. Wagner, Michael Khonsari, Ali Haghshenas

Michigan Tech Publications

In the present work the relationship between deformation and deformation induced surface roughness of 100 micron thick annealed AISI 304 stainless steel was investigated at the meso scale. This work is a continuation of the previous work by the authors where roughness values were determined at the apex of the bulge test samples at micro scale. The apex is believed to be the region of highest stress and strain in a typical bulge process in a circular die. The material was deformed using a biaxial bulge test through hydraulic fluid pressure. The strains on the workpieces were measured with respect ...


Conversion Of Self-Contained Breathing Apparatus Mask To Open Source Powered Air-Purifying Particulate Respirator For Fire Fighter Covid-19 Response, Benjamin R. Hubbard, Joshua M. Pearce Jun 2020

Conversion Of Self-Contained Breathing Apparatus Mask To Open Source Powered Air-Purifying Particulate Respirator For Fire Fighter Covid-19 Response, Benjamin R. Hubbard, Joshua M. Pearce

Michigan Tech Publications

To assist firefighters and other first responders to use their existing equipment for respiration during the COVID-19 pandemic without using single-use, low-supply, masks, this study outlines an open source kit to convert a 3M-manufactured Scott Safety self-contained breathing apparatus (SCBA) into a powered air-purifying particulate respirator (PAPR). The open source PAPR can be fabricated with a low-cost 3-D printer and widely available components for less than $150, replacing commercial conversion kits saving 85% or full-fledged proprietary PAPRs saving over 90%. The parametric designs allow for adaptation to other core components and can be custom fit specifically to fire-fighter equipment, including ...


Sparse And Random Sampling Techniques For High-Resolution, Full-Field, Bss-Based Structural Dynamics Identification From Video, Bridget Martinez, Andre Green, Moises Felipe Silva, David Mascareñas, Yongchao Yang Jun 2020

Sparse And Random Sampling Techniques For High-Resolution, Full-Field, Bss-Based Structural Dynamics Identification From Video, Bridget Martinez, Andre Green, Moises Felipe Silva, David Mascareñas, Yongchao Yang

Michigan Tech Publications

Video-based techniques for identification of structural dynamics have the advantage that they are very inexpensive to deploy compared to conventional accelerometer or strain gauge techniques. When structural dynamics from video is accomplished using full-field, high-resolution analysis techniques utilizing algorithms on the pixel time series such as principal components analysis and solutions to blind source separation the added benefit of high-resolution, full-field modal identification is achieved. An important property of video of vibrating structures is that it is particularly sparse. Typically video of vibrating structures has a dimensionality consisting of many thousands or even millions of pixels and hundreds to thousands ...


Open Source High-Temperature Reprap For 3-D Printing Heat-Sterilizable Ppe And Other Applications, Noah G. Skrzypczak, Nagendra Gautam Tanikella, Joshua M. Pearce May 2020

Open Source High-Temperature Reprap For 3-D Printing Heat-Sterilizable Ppe And Other Applications, Noah G. Skrzypczak, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Thermal sterilization is generally avoided for 3-D printed components because of the relatively low deformation temperatures for common thermoplastics used for material extrusion-based additive manufacturing. 3-D printing materials required for high-temperature heat sterilizable components for COVID-19 and other applications demands 3-D printers with heated beds, hot ends that can reach higher temperatures than polytetrafluoroethylene (PTFE) hot ends and heated chambers to avoid part warping and delamination. There are several high temperature printers on the market, but their high costs make them inaccessible for full home-based distributed manufacturing required during pandemic lockdowns. To allow for all these requirements to be met ...


Parametric Nasopharyngeal Swab For Sampling Covid-19 And Other Respiratory Viruses: Open Source Design, Sla 3-D Printing And Uv Curing System, Nicole Gallup, Adam Pringle, Shane Oberloier, Nagendra Gautam Tanikella, Joshua M. Pearce May 2020

Parametric Nasopharyngeal Swab For Sampling Covid-19 And Other Respiratory Viruses: Open Source Design, Sla 3-D Printing And Uv Curing System, Nicole Gallup, Adam Pringle, Shane Oberloier, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Access to nasopharyngeal swabs for sampling remain a bottleneck in some regions for COVID19 testing. This study develops a distributed manufacturing solution using only an open source manufacturing tool chain consisting of two types of open source 3-D printing and batch UV curing, and provides a parametric fully free design of a nasopharyngeal swab. The swab was designed using parametric OpenSCAD in two components (a head with engineered break point and various handles), which has several advantages: i) minimizing print time on relatively slow SLA printers, ii) enabling the use of smaller print volume open source SLA printers, iii) reducing ...


Chlorine Removal From U.S. Solid Waste Blends Through Torrefaction, Zhuo Xu, Josh W. Albrecht, Shreyas Kolapkar, Stas Zinchik, Ezra Bar Ziv May 2020

Chlorine Removal From U.S. Solid Waste Blends Through Torrefaction, Zhuo Xu, Josh W. Albrecht, Shreyas Kolapkar, Stas Zinchik, Ezra Bar Ziv

Michigan Tech Publications

The amount of solid waste generated annually is increasing around the world. Although the waste has a high calorific value, one major obstacle that may prevent it from becoming a feedstock for power applications is the existence of polyvinyl chloride (PVC), which causes corrosion and emission issues after combustion due to its high chlorine content. Torrefaction is known to release hydrochloric acid; thus, it has been applied in this study for the reduction of chlorine from potential waste feedstocks. Fiber-plastic (60-40%) waste blends, with different chlorine content levels, as well as PVC were used in the current study. Torrefaction was ...


Energy Storage Power And Energy Sizing And Specification Using Hsspfc, Mehrzad M. Bijaieh, Wayne Weaver, Rush D. Robinett Iii Apr 2020

Energy Storage Power And Energy Sizing And Specification Using Hsspfc, Mehrzad M. Bijaieh, Wayne Weaver, Rush D. Robinett Iii

Michigan Tech Publications

The intermittent nature of renewable sources requires the integration of Energy Storage Systems (ESSs) with appropriate power and energy densities. One of the applications of Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is to size ESSs for power and energy densities by employing them as sole actuators of Microgrid (MG) systems. This Article provides a comprehensive yet simplified example of utilization of HSSPFC to size ESSs of inverter-based three-phase MG systems under hierarchical control. Here, the distributed Hamiltonian controller is expanded for control of parallel ESSs and power sharing metrics are defined to distribute power between hybrid storage systems ...


Electric Vehicle-Grid Integration With Voltage Regulation In Radial Distribution Networks, Chong Cao, Zhouquan Wu, Bo Chen Apr 2020

Electric Vehicle-Grid Integration With Voltage Regulation In Radial Distribution Networks, Chong Cao, Zhouquan Wu, Bo Chen

Michigan Tech Publications

In this paper, a vehicle-grid integration (VGI) control strategy for radial power distribution networks is presented. The control schemes are designed at both microgrid level and distribution level. At the VGI microgrid level, the available power capacity for electric vehicle (EV) charging is optimally allocated for charging electric vehicles to meet charging requirements. At the distribution grid level, a distributed voltage compensation algorithm is designed to recover voltage violation when it happens at a distribution node. The voltage compensation is achieved through a negotiation between the grid-level agent and VGI microgrid agents using the alternating direction method of multipliers. In ...


Fracture Toughness Analysis Of Epoxy-Recycled Rubber-Based Composite Reinforced With Graphene Nanoplatelets For Structural Applications In Automotive And Aeronautics, Alaeddin Burak Irez, Emin Bayraktar, Ibrahim Miskioglu Feb 2020

Fracture Toughness Analysis Of Epoxy-Recycled Rubber-Based Composite Reinforced With Graphene Nanoplatelets For Structural Applications In Automotive And Aeronautics, Alaeddin Burak Irez, Emin Bayraktar, Ibrahim Miskioglu

Michigan Tech Publications

This study proposes a new design of lightweight and cost-efficient composite materials for the aeronautic industry utilizing recycled fresh scrap rubber, epoxy resin, and graphene nanoplatelets (GnPs). After manufacturing the composites, their bending strength and fracture characteristics were investigated by three-point bending (3PB) tests. Halpin-Tsai homogenization adapted to composites containing GnPs was used to estimate the moduli of the composites, and satisfactory agreement with the 3PB test results was observed. In addition, 3PB tests were simulated by finite element method incorporating the Halpin-Tsai homogenization, and the resulting stress-strain curves were compared with the experimental results. Mechanical test results showed that ...


Publisher Correction: Evaporation Of A Sessile Droplet On A Slope., Mitch Timm, Esmaeil Dehdashti, Amir Jarrahi Darban, Hassan Masoud Feb 2020

Publisher Correction: Evaporation Of A Sessile Droplet On A Slope., Mitch Timm, Esmaeil Dehdashti, Amir Jarrahi Darban, Hassan Masoud

Michigan Tech Publications

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


Characterizing Meteorological Forecast Impact On Microgrid Optimization Performance And Design, Robert Jane, Gordon G. Parker, Gail Vaucher, Morris Berman Jan 2020

Characterizing Meteorological Forecast Impact On Microgrid Optimization Performance And Design, Robert Jane, Gordon G. Parker, Gail Vaucher, Morris Berman

Michigan Tech Publications

A microgrid consists of electrical generation sources, energy storage assets, loads, and the ability to function independently, or connect and share power with other electrical grids. Thefocus of this work is on the behavior of a microgrid, with both diesel generator and photovoltaic resources, whose heating or cooling loads are influenced by local meteorological conditions. Themicrogrid's fuel consumption and energy storage requirement were then examined as a function of the atmospheric conditions used by its energy management strategy (EMS). A fuel-optimal EMS, able to exploit meteorological forecasts, was developed and evaluated using a hybrid microgrid simulation. Weather forecast update ...


Tra-1-60-Positive/Cd45low Cells Found In The Peripheral Blood Of Prostate Cancer Patients With Metastatic Disease – A Proof-Of-Concept Study, Claudia Schäfer, Yawen Ju, Youngbin Tak, Cesar Vazquez, Sangyoon J. Han, Edwin Tan, Et Al. Jan 2020

Tra-1-60-Positive/Cd45low Cells Found In The Peripheral Blood Of Prostate Cancer Patients With Metastatic Disease – A Proof-Of-Concept Study, Claudia Schäfer, Yawen Ju, Youngbin Tak, Cesar Vazquez, Sangyoon J. Han, Edwin Tan, Et Al.

Michigan Tech Publications

Purpose

Over 90% of all cancer related deaths are due to metastasis. However, current diagnostic tools can't reliably discriminate between invasive and localized cancers.

Patients and methods

In this proof-of-concept study, we employed the embryonic stem cell marker TRA-1-60 (TRA+) to identify TRA + cells within the blood of prostate cancer patients and searched for TRA + cells in men with metastatic and localized cancers. We isolated whole peripheral blood mononuclear cells from 26 metastatic prostate cancer patients, from 13 patients with localized prostate cancer and from 17 healthy controls. Cells were stained for DAPI, CD45 and TRA + by immunofluorescence and ...


Primal-Dual 2-Approximation Algorithm For The Monotonic Multiple Depot Heterogeneous Traveling Salesman Problem, S. Rathinam, R. Ravi, J. Bae, K. Sundar Jan 2020

Primal-Dual 2-Approximation Algorithm For The Monotonic Multiple Depot Heterogeneous Traveling Salesman Problem, S. Rathinam, R. Ravi, J. Bae, K. Sundar

Michigan Tech Publications

We study a Multiple Depot Heterogeneous Traveling Salesman Problem (MDHTSP) where the cost of the traveling between any two targets depends on the type of the vehicle. The travel costs are assumed to be symmetric, satisfy the triangle inequality, and are monotonic, i.e., the travel costs between any two targets monotonically increases with the index of the vehicles. Exploiting the monotonic structure of the travel costs, we present a 2-approximation algorithm based on the primal-dual method.


Droop Control In Dq Coordinates For Fixed Frequency Inverter-Based Ac Microgrids, Mohamed Toub, Mehrzad Mohammadi Bijaieh, Wayne Weaver, Rush D. Robinett Iii, Mohamed Maaroufi, Ghassane Aniba Oct 2019

Droop Control In Dq Coordinates For Fixed Frequency Inverter-Based Ac Microgrids, Mohamed Toub, Mehrzad Mohammadi Bijaieh, Wayne Weaver, Rush D. Robinett Iii, Mohamed Maaroufi, Ghassane Aniba

Michigan Tech Publications

This paper presents a proof-of-concept for a novel dq droop control technique that applies DC droop control methods to fixed frequency inverter-based AC microgrids using the dq0 transformation. Microgrids are usually composed of distributed generation units (DGUs) that are electronically coupled to each other through power converters. An inherent property of inverter-based microgrids is that, unlike microgrids with spinning machines, the frequency of the parallel-connected DGUs is a global variable independent from the output power since the inverters can control the output waveform frequency with a high level of precision. Therefore, conventional droop control methods that distort the system frequency ...


Open Source Waste Plastic Granulator, Arvind Ravindran, Sean Scsavnicki, Walker Nelson, Peter Gorecki, Jacob Franz, Shane Oberloier, Theresa K. Meyer, Andrew Barnard, Joshua M. Pearce Oct 2019

Open Source Waste Plastic Granulator, Arvind Ravindran, Sean Scsavnicki, Walker Nelson, Peter Gorecki, Jacob Franz, Shane Oberloier, Theresa K. Meyer, Andrew Barnard, Joshua M. Pearce

Michigan Tech Publications

In order to accelerate deployment of distributed recycling by providing low-cost feed stocks of granulated post-consumer waste plastic, this study analyzes an open source waste plastic granulator system. It is designed, built, and tested for its ability to convert post-consumer waste, 3D printed products and waste into polymer feedstock for recyclebots of fused particle/granule printers. The technical specifications of the device are quantified in terms of power consumption (380 to 404 W for PET and PLA, respectively) and particle size distribution. The open source device can be fabricated for less than $2000 USD in materials. The experimentally measured power ...


Design Of Hydroxyapatite/Magnetite (Hap/Fe3o4) Based Composites Reinforced With Zno And Mgo For Biomedical Applications, D. Katundi, E. Bayraktar, F. Gatamorta, I. Miskioglu Oct 2019

Design Of Hydroxyapatite/Magnetite (Hap/Fe3o4) Based Composites Reinforced With Zno And Mgo For Biomedical Applications, D. Katundi, E. Bayraktar, F. Gatamorta, I. Miskioglu

Michigan Tech Publications

Hydroxyapatite (HAP-- Ca 10(PO4 )6 (OH)2 ) is a biocompatible and bioactive material that is widely used for biomedical applications, especially in bone replacements. It has good load carrying capacity; however, it lacks antibacterial property. New bio-composites based on bovine hydroxyapatite doped with, magnetite iron oxide (HAP/ Fe3 O4 ) matrix reinforced with ZnO and MgO nanoparticles are proposed for biomedical applications that provide improved antibacterial activity with potential to be used in magnetic therapy. Microwave sintering was used to manufacture the composites. The microstructure evolution in these composites were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy ...


Optimal And Decentralized Control Strategies For Inverter-Based Ac Microgrids, Michael D. Cook, Eddy H. Trinklein, Gordon Parker, Rush D. Robinett Iii, Wayne Weaver Sep 2019

Optimal And Decentralized Control Strategies For Inverter-Based Ac Microgrids, Michael D. Cook, Eddy H. Trinklein, Gordon Parker, Rush D. Robinett Iii, Wayne Weaver

Michigan Tech Publications

This paper presents two control strategies: (i) An optimal exergy destruction (OXD) controller and (ii) a decentralized power apportionment (DPA) controller. The OXD controller is an analytical, closed-loop optimal feedforward controller developed utilizing exergy analysis to minimize exergy destruction in an AC inverter microgrid. The OXD controller requires a star or fully connected topology, whereas the DPA operates with no communication among the inverters. The DPA presents a viable alternative to conventional P−ω/Q−V droop control, and does not suffer from fluctuations in bus frequency or steady-state voltage while taking advantage of distributed storage assets necessary for the ...


Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas Aug 2019

Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas

Michigan Tech Publications

To achieve persistent systems in the future, autonomous underwater vehicles (AUVs) will need to autonomously dock onto a charging station. Here, reinforcement learning strategies were applied for the first time to control the docking of an AUV onto a fixed platform in a simulation environment. Two reinforcement learning schemes were investigated: one with continuous state and action spaces, deep deterministic policy gradient (DDPG), and one with continuous state but discrete action spaces, deep Q network (DQN). For DQN, the discrete actions were selected as step changes in the control input signals. The performance of the reinforcement learning strategies was compared ...


Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai Jul 2019

Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai

Michigan Tech Publications

This paper presents our recent work on investigating velocity slip boundary conditions’ effects on supersonic flat plate boundary layer flow stability. The velocity-slip boundary conditions are adopted and the flow properties are obtained by solving boundary layer equations. Stability analysis of two such boundary layer flows is performed by using the Linear stability theory. A global method is first utilized to obtain approximate discrete mode values. A local method is then utilized to refine these mode values. All the modes in these two scenarios have been tracked upstream-wisely towards the leading edge and also downstream-wisely. The mode values for the ...


Mapping Modeled Exposure Of Wildland Fire Smoke For Human Health Studies In California, Patricia Koman, Michael Billmire, Kirk Baker, Ricardo De Majo, Frank Anderson, Sumi Hoshiko, Brian Thelen, Nancy H. F. French Jun 2019

Mapping Modeled Exposure Of Wildland Fire Smoke For Human Health Studies In California, Patricia Koman, Michael Billmire, Kirk Baker, Ricardo De Majo, Frank Anderson, Sumi Hoshiko, Brian Thelen, Nancy H. F. French

Michigan Tech Publications

Wildland fire smoke exposure affects a broad proportion of the U.S. population and is increasing due to climate change, settlement patterns and fire seclusion. Significant public health questions surrounding its effects remain, including the impact on cardiovascular disease and maternal health. Using atmospheric chemical transport modeling, we examined general air quality with and without wildland fire smoke PM2.5. The 24-h average concentration of PM2.5 from all sources in 12-km gridded output from all sources in California (2007–2013) was 4.91 μg/m3. The average concentration of fire-PM2.5 in California by year ...


Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce May 2019

Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Past work has shown that particle material extrusion (fused particle fabrication (FPF)/fused granular fabrication (FGF)) has the potential for increasing the use of recycled polymers in 3D printing. This study extends this potential to high-performance (high-mechanical-strength and heat-resistant) polymers using polycarbonate (PC). Recycled PC regrind of approximately 25 mm2 was 3D printed with an open-source Gigabot X and analyzed. A temperature and nozzle velocity matrix was used to find useful printing parameters, and a print test was used to maximize the output for a two-temperature stage extruder for PC. ASTM type 4 tensile test geometries as well as ...


Open Source Completely 3-D Printable Centrifuge, Salil S. Sule, Aliaksei Petsiuk, Joshua M. Pearce May 2019

Open Source Completely 3-D Printable Centrifuge, Salil S. Sule, Aliaksei Petsiuk, Joshua M. Pearce

Michigan Tech Publications

Centrifuges are commonly required devices in medical diagnostics facilities as well as scientific laboratories. Although there are commercial and open source centrifuges, the costs of the former and the required electricity to operate the latter limit accessibility in resource-constrained settings. There is a need for low-cost, human-powered, verified, and reliable lab-scale centrifuges. This study provides the designs for a low-cost 100% 3-D printed centrifuge, which can be fabricated on any low-cost RepRap-class (self-replicating rapid prototyper) fused filament fabrication (FFF)- or fused particle fabrication (FPF)-based 3-D printer. In addition, validation procedures are provided using a web camera and free and ...


Capillary Penetration Method For Measuring Wetting Properties Of Carbon Ionomer Films For Proton Exchange Membrane Fuel Cell (Pemfc) Applications, Sofyane Abbou, Kazuya Tajiri, K. T. Alofari, Ezequiel F. Medici, A. T. Haug, Jeffrey S. Allen Apr 2019

Capillary Penetration Method For Measuring Wetting Properties Of Carbon Ionomer Films For Proton Exchange Membrane Fuel Cell (Pemfc) Applications, Sofyane Abbou, Kazuya Tajiri, K. T. Alofari, Ezequiel F. Medici, A. T. Haug, Jeffrey S. Allen

Michigan Tech Publications

In this work, capillary rise experiments were performed to assess the wetting properties of carbon-ionomer (CI) films. The samples were attached to a micro-balance and then immersed into liquid water to (i) measure the mass gain from the liquid uptake and (ii) estimate the (external) contact angle to water (typical value around 140°). The results showed that drying the CI films under low vacuum significantly impacted the CI film wettability. The influence of the ionomer content on the CI films’ wettability was investigated with various ionomer to carbon (I/C) ratios: 0.8, 1.0, 1.2 and 1.4 ...


Multidimensional Optimal Droop Control For Dc Microgrids In Military Applications, Kaitlyn J. Bunker, Michael D. Cook, Wayne Weaver, Gordon Parker Oct 2018

Multidimensional Optimal Droop Control For Dc Microgrids In Military Applications, Kaitlyn J. Bunker, Michael D. Cook, Wayne Weaver, Gordon Parker

Michigan Tech Publications

Reliability is a key consideration when microgrid technology is implemented in military applications. Droop control provides a simple option without requiring communication between microgrid components, increasing the control system reliability. However, traditional droop control does not allow the microgrid to utilize much of the power available from a solar resource. This paper applies an optimal multidimensional droop control strategy for a solar resource connected in a microgrid at a military patrol base. Simulation and hardware-in-the-loop experiments of a sample microgrid show that much more power from the solar resource can be utilized, while maintaining the system’s bus voltage around ...


Properties Of Torrefied U.S. Waste Blends, Zhou Xu, Stas Zinchik, Shreyas Kolapkar, Ezra Bar Ziv, Ted Hansen, Dennis Conn, Armando G. Mcdonald Jul 2018

Properties Of Torrefied U.S. Waste Blends, Zhou Xu, Stas Zinchik, Shreyas Kolapkar, Ezra Bar Ziv, Ted Hansen, Dennis Conn, Armando G. Mcdonald

Michigan Tech Publications

Power generation facilities in the U.S. are looking for a potential renewable fuel that is sustainable, low-cost, complies with environmental regulation standards and is a drop-in fuel in the existing infrastructure. Although torrefied woody biomass, meets most of these requirements, its high cost, due to the use of woody biomass, prevented its commercialization. Industrial waste blends, which are also mostly renewable, are suitable feedstock for torrefaction, and can be an economically viable solution, thus may prolong the life of some of the existing coal power plants in the U.S. This paper focuses on the torrefaction dynamics of paper ...


Control Of Wave Energy Converters With Discrete Displacement Hydraulic Power Take-Off Units, Shangyan Zou, Ossama Abdelkhalik Apr 2018

Control Of Wave Energy Converters With Discrete Displacement Hydraulic Power Take-Off Units, Shangyan Zou, Ossama Abdelkhalik

Michigan Tech Publications

The control of ocean Wave Energy Converters (WECs) impacts the harvested energy. Several control methods have been developed over the past few decades to maximize the harvested energy. Many of these methods were developed based on an unconstrained dynamic model assuming an ideal power take-off (PTO) unit. This study presents numerical tests and comparisons of a few recently developed control methods. The testing is conducted using a numerical simulator that simulates a hydraulic PTO. The PTO imposes constraints on the maximum attainable control force and maximum stroke. In addition, the PTO has its own dynamics, which may impact the performance ...


The Role Of Electron Irradiation History In Liquid Cell Transmission Electron Microscopy., Trevor H Moser, Hardeep Mehta, Chiwoo Park, Ryan T Kelly, Tolou Shokuhfar, James E Evans Apr 2018

The Role Of Electron Irradiation History In Liquid Cell Transmission Electron Microscopy., Trevor H Moser, Hardeep Mehta, Chiwoo Park, Ryan T Kelly, Tolou Shokuhfar, James E Evans

Michigan Tech Publications

In situ liquid cell transmission electron microscopy (LC-TEM) allows dynamic nanoscale characterization of systems in a hydrated state. Although powerful, this technique remains impaired by issues of repeatability that limit experimental fidelity and hinder the identification and control of some variables underlying observed dynamics. We detail new LC-TEM devices that improve experimental reproducibility by expanding available imaging area and providing a platform for investigating electron flux history on the sample. Irradiation history is an important factor influencing LC-TEM results that has, to this point, been largely qualitatively and not quantitatively described. We use these devices to highlight the role of ...