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Articles 1381 - 1410 of 2631

Full-Text Articles in Engineering

Gain Scheduled Torque Compensation Of Pmsg-Based Wind Turbine For Frequency Regulation In An Isolated Grid, Haixin Wang, Junyou Yang, Zhe Chen, Weichun Ge, Shiyan Hu, Yiming Ma, Et Al. Jun 2018

Gain Scheduled Torque Compensation Of Pmsg-Based Wind Turbine For Frequency Regulation In An Isolated Grid, Haixin Wang, Junyou Yang, Zhe Chen, Weichun Ge, Shiyan Hu, Yiming Ma, Et Al.

Michigan Tech Publications, Part 1

Frequency stability in an isolated grid can be easily impacted by sudden load or wind speed changes. Many frequency regulation techniques are utilized to solve this problem. However, there are only few studies designing torque compensation controllers based on power performances in different Speed Parts. It is a major challenge for a wind turbine generator (WTG) to achieve the satisfactory compensation performance in different Speed Parts. To tackle this challenge, this paper proposes a gain scheduled torque compensation strategy for permanent magnet synchronous generator (PMSG) based wind turbines. Our main idea is to improve the anti-disturbance ability for frequency regulation …


Laboratory Evaluation On Performance Of Compound-Modified Asphalt For Rock Asphalt/Styrene–Butadiene Rubber (Sbr) And Rock Asphalt/Nano-Caco3, Songtao Lv, Shuangshuang Wang, Tong Guo, Chengdong Xia, Jianglong Li, Gui Hou Jun 2018

Laboratory Evaluation On Performance Of Compound-Modified Asphalt For Rock Asphalt/Styrene–Butadiene Rubber (Sbr) And Rock Asphalt/Nano-Caco3, Songtao Lv, Shuangshuang Wang, Tong Guo, Chengdong Xia, Jianglong Li, Gui Hou

Michigan Tech Publications, Part 1

As a natural modifier of asphalt, rock asphalt has been widely used to improve its thermal stability and aging resistance. However, the thermal cracking resistance of asphalt modified by rock asphalt is unsatisfactory. In order to improve the thermal cracking resistance in low temperature, two kinds of modifiers—styrene–butadiene rubber (SBR) and nano-CaCO3—were selected as the compound modifiers, and then implemented to improve the low-temperature performance of the binder. Then, compound asphalt modified by Buton rock asphalt (BRA) was chosen as the study subject. The thermal stability and aging resistance of asphalt modified by BRA, compound-modified asphalt by BRA/SBR, …


Assessment Of Soil Erosion Vulnerability In The Heavily Populated And Ecologically Fragile Communities In Motozintla De Mendoza, Chiapas, Mexico, Selene González-Morales, Alex Mayer, Neptalí Ramírez-Marcial Jun 2018

Assessment Of Soil Erosion Vulnerability In The Heavily Populated And Ecologically Fragile Communities In Motozintla De Mendoza, Chiapas, Mexico, Selene González-Morales, Alex Mayer, Neptalí Ramírez-Marcial

Michigan Tech Publications, Part 1

Variability in physical rates and local knowledge of soil erosion was assessed across six rural communities in the Sierra Madre del Sur, Chiapas, Mexico. The average erosion rate estimated using the RUSLE model is 274 t ha-1 yr-1, with the estimated erosion rates ranging from 28 to 717 t ha-1 yr-1. These very high erosion rates are associated with high rainfall erosivity (17 000 MJ mm ha-1 h-1 yr-1) and steep slopes (mean slope Combining double low line 67 %). Many of the highest soil erosion rates are found in communities that are dominated by forestland, but where most of …


Sensitivity Of Atmospheric Aerosol Scavenging To Precipitation Intensity And Frequency In The Context Of Global Climate Change, Pei Hou, Shiliang Wu, Jessica L. Mccarty, Yang Gao Jun 2018

Sensitivity Of Atmospheric Aerosol Scavenging To Precipitation Intensity And Frequency In The Context Of Global Climate Change, Pei Hou, Shiliang Wu, Jessica L. Mccarty, Yang Gao

Michigan Tech Publications, Part 1

Wet deposition driven by precipitation is an important sink for atmospheric aerosols and soluble gases. We investigate the sensitivity of atmospheric aerosol lifetimes to precipitation intensity and frequency in the context of global climate change. Our sensitivity model simulations, through some simplified perturbations to precipitation in the GEOS-Chem model, show that the removal efficiency and hence the atmospheric lifetime of aerosols have significantly higher sensitivities to precipitation frequencies than to precipitation intensities, indicating that the same amount of precipitation may lead to different removal efficiencies of atmospheric aerosols. Combining the long-term trends of precipitation patterns for various regions with the …


The Effect Of Nd On Mechanical Properties And Corrosion Performance Of Biodegradable Mg-5%Zn Alloy, Lilach Elkaiam, Orly Hakimi, Jeremy Goldman, Eli Aghion Jun 2018

The Effect Of Nd On Mechanical Properties And Corrosion Performance Of Biodegradable Mg-5%Zn Alloy, Lilach Elkaiam, Orly Hakimi, Jeremy Goldman, Eli Aghion

Michigan Tech Publications, Part 1

Mg based implants are limited by their poor strength, ductility, and corrosion performance in physiological environments, drawbacks further compounded by their premature loss of mechanical integrity and evolution of harmful hydrogen gas. Neodymium additions to magnesium have been shown to improve mechanical properties through precipitation and solid solution hardening. Therefore, the present study incorporated Nd additions (up to 3%) into a promising Mg-5%Zn-0.13%Y-0.35%Zr alloy to improve mechanical properties and corrosion resistance. The microstructure evaluation of a series of alloys was performed using optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction analysis. The mechanical properties were examined in terms of …


Rheological Behavior And Sensitivity Of Wood-Derived Bio-Oil Modified Asphalt Binders, Junfeng Gao, Hainian Wang, Zhanping You, Mohd Rosli Mohd Hasan, Yong Lei, Muhammad Irfan Jun 2018

Rheological Behavior And Sensitivity Of Wood-Derived Bio-Oil Modified Asphalt Binders, Junfeng Gao, Hainian Wang, Zhanping You, Mohd Rosli Mohd Hasan, Yong Lei, Muhammad Irfan

Michigan Tech Publications, Part 1

The demand for bituminous materials is continuously growing; crude oil-based asphalt binders are non-renewable, and are facing rapid depletion. With the increase of petroleum-based asphalt prices, seeking an alternative, renewable material such as bio-asphalt has become a hot research topic. However, shortcomings in this research area have been identified, notably concerning the high-temperature performance of bio-asphalt at present. This research aims to comprehensively apply conventional tests to, and study the rheological behavior of, the high-temperature performances of bio-asphalt binders, i.e., by temperature and frequency sweeps, using a dynamic shear rheometer (DSR). It will also assess the chemical functional groups of …


Me-Em Enewsbrief, June 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Jun 2018

Me-Em Enewsbrief, June 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


A National Pragmatic Safety Limit For Nuclear Weapon Quantities, Joshua M. Pearce, David C. Denkenberger Jun 2018

A National Pragmatic Safety Limit For Nuclear Weapon Quantities, Joshua M. Pearce, David C. Denkenberger

Department of Materials Science and Engineering Publications

This study determines the nuclear pragmatic limit where the direct physical negative consequences of nuclear weapons use are counter to national interests, by assuming all unknowns are conservatively optimistic. The only effect considered is nuclear winter (“nuclear autumn” in the low weapons limits) and the resultant effects on the aggressor nation. First, the ability of low nuclear weapon limits is probed for maintaining deterrence in the worst-case scenario of attacking the most-populous nation. Second, the ability of aggressor nations to feed themselves is assessed without trade and industry resultant from a nuclear attack causing “nuclear autumn” (10% global agricultural shortfall). …


Bioactive Polydimethylsiloxane Surface For Optimal Human Mesenchymal Stem Cell Sheet Culture, Zichen Qian, David Ross, Wenkai Jia, Qi Xing, Feng Zhao Jun 2018

Bioactive Polydimethylsiloxane Surface For Optimal Human Mesenchymal Stem Cell Sheet Culture, Zichen Qian, David Ross, Wenkai Jia, Qi Xing, Feng Zhao

Michigan Tech Publications, Part 1

Human mesenchymal stem cell (hMSC) sheets hold great potential in engineering three-dimensional (3D) completely biological tissues for diverse applications. Conventional cell sheet culturing methods employing thermoresponsive surfaces are cost ineffective, and rely heavily on available facilities. In this study, a cost-effective method of layer-by-layer grafting was utilized for covalently binding a homogenous collagen I layer on a commonly used polydimethylsiloxane (PDMS) substrate surface in order to improve its cell adhesion as well as the uniformity of the resulting hMSC cell sheet. Results showed that a homogenous collagen I layer was obtained via this grafting method, which improved hMSC adhesion and …


Self-Sufficiency Of 3-D Printers: Utilizing Stand-Alone Solar Photovoltaic Power Systems, Khalid Yousuf Khan, Lucia Gauchia, Joshua M. Pearce May 2018

Self-Sufficiency Of 3-D Printers: Utilizing Stand-Alone Solar Photovoltaic Power Systems, Khalid Yousuf Khan, Lucia Gauchia, Joshua M. Pearce

Department of Materials Science and Engineering Publications

A self-replicating rapid prototyper (RepRap) is a type of 3-D printer capable of printing many of its own components in addition to a wide assortment of products from high-value scientific or medical tools to household products and toys. There is some evidence that these printers could provide low-cost distributed manufacturing in underprivileged rural areas. For the most isolated communities without access to the electric grid, a low-cost alternative energy is needed. Solar energy can be harvested through a stand-alone photovoltaic (PV) power system specifically designed to match the needs of the RepRap. The voltage and current requirement for the printer …


Implementation Of Unmanned Aerial Vehicles (Uavs) For Assessment Of Transportation Infrastructure - Phase Ii, Colin Brooks, Richard Dobson, David Banach, Thomas Oommen, Kuilin Zhang, Amlan Mukherjee, Timothy C. Havens, Theresa Ahlborn, Rudiger Escobar-Wolf, Chaitanya Ganesh Bhat, S. Zhao, Q. Lyu, Nicholas Marion May 2018

Implementation Of Unmanned Aerial Vehicles (Uavs) For Assessment Of Transportation Infrastructure - Phase Ii, Colin Brooks, Richard Dobson, David Banach, Thomas Oommen, Kuilin Zhang, Amlan Mukherjee, Timothy C. Havens, Theresa Ahlborn, Rudiger Escobar-Wolf, Chaitanya Ganesh Bhat, S. Zhao, Q. Lyu, Nicholas Marion

Michigan Tech Publications, Part 1

Technological advances in unmanned aerial vehicle (UAV) technologies continue to enable these tools to become easier to use, more economical, and applicable for transportation-related operations, maintenance, and asset management while also increasing safety and decreasing cost. This Phase 2 project continued to test and evaluate five main UAV platforms with a combination of optical, thermal, and lidar sensors to determine how to implement them into MDOT workflows. Field demonstrations were completed at bridges, a construction site, road corridors, and along highways with data being processed and analyzed using customized algorithms and tools. Additionally, a cost-benefit analysis was conducted, comparing manual …


Optimal Level Of Woody Biomass Co-Firing With Coal Power Plant Considering Advanced Feedstock Logistics System, Sangpil Ko, Pasi T. Lautala May 2018

Optimal Level Of Woody Biomass Co-Firing With Coal Power Plant Considering Advanced Feedstock Logistics System, Sangpil Ko, Pasi T. Lautala

Michigan Tech Publications, Part 1

Co-firing from woody biomass feedstock is one of the alternatives toward increased use of renewable feedstock in existing coal power plants. However, the economic level of co-firing at a particular power plant depends on several site-specific factors. Torrefaction has been identified recently as a promising biomass pretreatment option to lead to reduction of the feedstock delivered cost, and thus facilitate an increase in the co-firing ratio. In this study, a mixed integer linear program (MILP) is developed to integrate supply chain of co-firing and torrefaction process and find the optimal level of biomass co-firing in terms of minimized transportation and …


Application Of Composite Hydrogels To Control Physical Properties In Tissue Engineering And Regenerative Medicine, Cassidy Sheffield, Kaylee Meyers, Emil Johnson, Rupak Rajachar May 2018

Application Of Composite Hydrogels To Control Physical Properties In Tissue Engineering And Regenerative Medicine, Cassidy Sheffield, Kaylee Meyers, Emil Johnson, Rupak Rajachar

Michigan Tech Publications, Part 1

The development of biomaterials for the restoration of the normal tissue structure–function relationship in pathological conditions as well as acute and chronic injury is an area of intense investigation. More recently, the use of tailored or composite hydrogels for tissue engineering and regenerative medicine has sought to bridge the gap between natural tissues and applied biomaterials more clearly. By applying traditional concepts in engineering composites, these hydrogels represent hierarchical structured materials that translate more closely the key guiding principles required for improved recovery of tissue architecture and functional behavior, including physical, mass transport, and biological properties. For tissue-engineering scaffolds in …


Study On Components Determination And Performance Evaluation Of Ls Pre-Maintenance Agent, Yuxiang Tian, Biao Ma, Ke Tian, Ning Li, Xueyan Zhou May 2018

Study On Components Determination And Performance Evaluation Of Ls Pre-Maintenance Agent, Yuxiang Tian, Biao Ma, Ke Tian, Ning Li, Xueyan Zhou

Michigan Tech Publications, Part 1

Adequate maintenance and taking active preventive measures can effectively prevent the early disease of asphalt pavements before significant damage occurs. By developing a light screening preventive maintenance agent (LS pre-maintenance agent) for strong ultraviolet (UV) radiation areas, based on the asphalt aging and regeneration mechanism, we analyzed the function and basic components and determined the optimum components ratio based on the best proportion of penetrant and solvent oil for solubility. The optimum ratio for quick-drying and long-term storage ability is the mass ratio of rock asphalt, reducing agent, penetrant, and solvent oil, which is 30:20:20:30. The light-shield agent is 5% …


Selective Flocculation Separation Of Fine Hematite From Quartz Using A Novel Grafted Copolymer Flocculant, Jinxia Zhang, Weiguang Sun, Zhiyong Gao, Fusheng Niu, Long Wang, Yawei Zhao, Yuesheng Gao May 2018

Selective Flocculation Separation Of Fine Hematite From Quartz Using A Novel Grafted Copolymer Flocculant, Jinxia Zhang, Weiguang Sun, Zhiyong Gao, Fusheng Niu, Long Wang, Yawei Zhao, Yuesheng Gao

Michigan Tech Publications, Part 1

Beneficiation of ultrafine mineral particles (typically with an average size less than 20 µm) remains a critical problem for the mineral processing industry. Selective flocculation technique has been found to show great potential to tackle this problem, whose success mainly depends on the selective adsorption of a flocculant on the target mineral particles. In this work, a novel copolymer flocculant was synthesized by grafting starch and acrylamide, which for the first time, was employed in the flocculation separation of fine hematite from quartz. The composites of the grafted copolymer flocculant (GCF) were characterized by Fourier transform infrared spectroscopy (FTIR) and …


Recent Developments In Tough Hydrogels For Biomedical Applications, Yuan Liu, Weilue He, Zhongtian Zhang, Bruce P. Lee May 2018

Recent Developments In Tough Hydrogels For Biomedical Applications, Yuan Liu, Weilue He, Zhongtian Zhang, Bruce P. Lee

Department of Biomedical Engineering Publications

A hydrogel is a three-dimensional polymer network with high water content and has been attractive for many biomedical applications due to its excellent biocompatibility. However, classic hydrogels are mechanically weak and unsuitable for most physiological load-bearing situations. Thus, the development of tough hydrogels used in the biomedical field becomes critical. This work reviews various strategies to fabricate tough hydrogels with the introduction of non-covalent bonds and the construction of stretchable polymer networks and interpenetrated networks, such as the so-called double-network hydrogel. Additionally, the design of tough hydrogels for tissue adhesive, tissue engineering, and soft actuators is reviewed.


Characteristics Of Moduli Decay For The Asphalt Mixture Under Different Loading Conditions, Songtao Lv, Xiyan Fan, Chengdong Xia, Jianlong Zheng, Dong Chen, Lingyun You May 2018

Characteristics Of Moduli Decay For The Asphalt Mixture Under Different Loading Conditions, Songtao Lv, Xiyan Fan, Chengdong Xia, Jianlong Zheng, Dong Chen, Lingyun You

Michigan Tech Publications, Part 1

In order to explore the moduli decay patterns of asphalt mixtures under different loading conditions, the nonlinear fatigue damage model was implemented in order to simulate the moduli decay patterns. Then, the direct tensile, indirect tensile, and uniaxial compression fatigue tests were employed under four kinds of stress levels with four parallel tests. The specimens of AC-13C Styrene-butadiene-styrene (SBS) modified mixtures were manufactured. Based on the test results, the decay patterns of the moduli during fatigue tests under different stress states were revealed, and the parameters of the damage model under different test conditions were obtained. By changing the values …


Effect Of Zr Additions On Thermal Stability Of Al-Cu Precipitates In As-Cast And Cold Worked Samples, Kyle Deane, Paul G. Sanders May 2018

Effect Of Zr Additions On Thermal Stability Of Al-Cu Precipitates In As-Cast And Cold Worked Samples, Kyle Deane, Paul G. Sanders

Michigan Tech Publications, Part 1

While Zr is frequently added to Al alloys to control grain size with the formation of large (>1 μm) primary precipitates, little research has been conducted on the effect of nanoscale Al3Zr precipitates on Al alloys. By comparing the precipitation and corresponding strength evolution between Al-Cu-Zr alloys with different Zr concentrations, the effects of Zr on Al-Cu precipitation with and without primary Al3Zr precipitates can be observed. In the absence of these large precipitates, all Al3Zr phases can be formed, through high temperature aging treatments, as a dispersion of nanoprecipaites inside the Al …


Probability Distributions In The Glass Failure Prediction Model, Samir Blanchet, H. Scott Norville, Stephen Morse May 2018

Probability Distributions In The Glass Failure Prediction Model, Samir Blanchet, H. Scott Norville, Stephen Morse

Michigan Tech Publications, Part 1

Glass, a brittle material, fractures under tensile stress acting over a time duration. Lateral loads, such as wind, acting on a simply supported rectangular glass lite, put one surface of the lite primarily into tension. ASTM E 1300 defines load resistance of glass as the uniform lateral loading acting over a duration of 3 seconds that is associated with a probability of breakage of 8 lites per 1000 at the first occurrence of the loading. To determine load resistance, the underlying window glass failure prediction model facilitates determination of a probability distribution of 3 second equivalent failure loads, P3. The …


Reprapable Recyclebot: Open Source 3-D Printable Extruder For Converting Plastic To 3-D Printing Filament, Aubrey Woern, Joseph Mccaslin, Adam Pringle, Joshua M. Pearce May 2018

Reprapable Recyclebot: Open Source 3-D Printable Extruder For Converting Plastic To 3-D Printing Filament, Aubrey Woern, Joseph Mccaslin, Adam Pringle, Joshua M. Pearce

Department of Materials Science and Engineering Publications

In order to assist researchers explore the full potential of distributed recycling of post-consumer polymer waste, this article describes a recyclebot, which is a waste plastic extruder capable of making commercial quality 3-D printing filament. The device design takes advantage of both the open source hardware methodology and the paradigm developed by the open source self-replicating rapid prototyper (RepRap) 3-D printer community. Specifically, this paper describes the design, fabrication and operation of a RepRapable Recyclebot, which refers to the Recyclebot’s ability to provide the filament needed to largely replicate the parts for the Recyclebot on any type of RepRap 3-D …


The Natural Aging Effect On Hardenability In Al-Mg-Si: A Complex Interaction Between Composition And Heat Treatment Parameters, Alex Poznak, Violet Thole, Paul G. Sanders May 2018

The Natural Aging Effect On Hardenability In Al-Mg-Si: A Complex Interaction Between Composition And Heat Treatment Parameters, Alex Poznak, Violet Thole, Paul G. Sanders

Michigan Tech Publications, Part 1

The technological relevance of Al-Mg-Si alloys has been rapidly growing over the last decade. Of particular interest to current and future applications is the problematic negative effect of prior natural aging on subsequent artificial age hardening. The influence of natural aging is dependent on both processing and compositional variables and has origins that are far from well-understood. This work examines the hardenability of 6000 series alloys under a wide range of conditions, paying particular attention to the natural aging effect. Experimental variables include alloy composition (Mg + Si, Mg/Si), cooling rate after solutionization, and duration of prior natural aging. Hardenability …


Fatigue Equation Of Cement-Treated Aggregate Base Materials Under A True Stress Ratio, Songtao Lv, Chaochao Liu, Jingting Lan, Hongwei Zhang, Jianlong Zheng, Zhanping You Apr 2018

Fatigue Equation Of Cement-Treated Aggregate Base Materials Under A True Stress Ratio, Songtao Lv, Chaochao Liu, Jingting Lan, Hongwei Zhang, Jianlong Zheng, Zhanping You

Michigan Tech Publications, Part 1

The objective of this article is to establish a fatigue equation based on the true stress ratio for cement-treated aggregate base materials. The true stress ratio herein means the ratio of the stress and the true strength of the cement-treated aggregate base materials related to loading rates and curing times. The unconfined compressive strength tests and compressive resilience modulus tests were carried out under various loading rates and curing times of 3, 7, 14, 28, 60, 90 days, respectively. According to the test results, the relationship between the unconfined compressive strength (a mix design parameter in China) and the compressive …


The Ozone Monitoring Instrument: Overview Of 14 Years In Space, Pieternel F. Levelt, Joanna Joiner, Johanna Tamminen, J. Pepijn Veefkind, Pawan K. Bhartia, Simon Carn, Et. Al. Apr 2018

The Ozone Monitoring Instrument: Overview Of 14 Years In Space, Pieternel F. Levelt, Joanna Joiner, Johanna Tamminen, J. Pepijn Veefkind, Pawan K. Bhartia, Simon Carn, Et. Al.

Michigan Tech Publications, Part 1

This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development …


Advanced Paving Materials And Technologies, Zhanping You, Qingli Dai, Feipeng Xiao Apr 2018

Advanced Paving Materials And Technologies, Zhanping You, Qingli Dai, Feipeng Xiao

Michigan Tech Publications, Part 1

No abstract provided.


Metabolism-Driven High-Throughput Cancer Identification With Glut5-Specific Molecular Probes, Srinivas Kannan, Vagarshak Begoyan, Joseph Fedie, Shuai Xia, Łukasz J. Weseliński, Marina Tanasova, Smitha Rao Apr 2018

Metabolism-Driven High-Throughput Cancer Identification With Glut5-Specific Molecular Probes, Srinivas Kannan, Vagarshak Begoyan, Joseph Fedie, Shuai Xia, Łukasz J. Weseliński, Marina Tanasova, Smitha Rao

Michigan Tech Publications, Part 1

Point-of-care applications rely on biomedical sensors to enable rapid detection with high sensitivity and selectivity. Despite advances in sensor development, there are challenges in cancer diagnostics. Detection of biomarkers, cell receptors, circulating tumor cells, gene identification, and fluorescent tagging are time-consuming due to the sample preparation and response time involved. Here, we present a novel approach to target the enhanced metabolism in breast cancers for rapid detection using fluorescent imaging. Fluorescent analogs of fructose target the fructose-specific transporter GLUT5 in breast cancers and have limited to no response from normal cells. These analogs demonstrate a marked difference in adenocarcinoma and …


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, Part 1

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 …


Design Optimization Of Polymer Heat Exchanger For Automated Household-Scale Solar Water Pasteurizer, David C. Denkenberger, Joshua M. Pearce Apr 2018

Design Optimization Of Polymer Heat Exchanger For Automated Household-Scale Solar Water Pasteurizer, David C. Denkenberger, Joshua M. Pearce

Department of Materials Science and Engineering Publications

A promising approach to reducing the >870,000 deaths/year globally from unsafe water is flow-through solar water pasteurization systems (SWPs). Unfortunately, demonstrated systems have high capital costs, which limits access for the poor. The most expensive component of such systems is the heat exchanger (HX). Thus, this study focuses on cost optimization of HX designs for flow-through SWPs using high-effectiveness polymer microchannel HXs. The theoretical foundation for the cost optimization of a polymer microchannel HX is provided, and outputs are plotted in order to provide guidelines for designers to perform HX optimizations. These plots are used in two case studies: (1) …


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, Part 1

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 …


The Circuit, Spring 2018, Department Of Electrical And Computer Engineering, Michigan Technological University Apr 2018

The Circuit, Spring 2018, Department Of Electrical And Computer Engineering, Michigan Technological University

Department of Electrical and Computer Engineering Newsletters

Table of Contents:

  • Fugere Generosity Creates Opportunities
  • Faculty News
  • Sparsifying Graphs for Faster Data Processing
  • Manipulating Electromagnetic Waves by Artificial Materials
  • Taking a Close Look at Computing
  • COVOX is My Co-Pilot
  • Taking on New Departmental Roles
  • Student News
  • Alumni Spotlight


Spatial Dispersion Of Index Components Required For Building Invisibility Cloak Medium From Photonic Crystals, Saeid Jamilan, George Semouchkin, Navid Gandji, Elena Semouchkina Mar 2018

Spatial Dispersion Of Index Components Required For Building Invisibility Cloak Medium From Photonic Crystals, Saeid Jamilan, George Semouchkin, Navid Gandji, Elena Semouchkina

Michigan Tech Publications, Part 1

The opportunities to use dielectric photonic crystals (PhCs) as the media of cylindrical invisibility cloaks, designed using transformation optics (TO) concepts, are investigated. It is shown that TO-based prescriptions for radial index dispersion, responsible for turning waves around hidden objects, can be dropped if the PhC media support self-collimation of waves in bent crystals. Otherwise, to provide prescribed anisotropy of index dispersion, it is possible to employ PhCs with rectangular lattices. It is found, however, that at acceptable cloak thicknesses, modifications of crystal parameters do not allow for achieving the prescribed level of index anisotropy. This problem is solved by …