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Full-Text Articles in Engineering

Revisiting The Paleomagnetism Of The Neoarchean Uauá Mafic Dyke Swarm, Brazil: Implications For Archean Supercratons, J. Salminen, E. P. Oliveira, Elisa J. Piispa, Aleksey Smirnov, R. I. F. Trindade Dec 2018

Revisiting The Paleomagnetism Of The Neoarchean Uauá Mafic Dyke Swarm, Brazil: Implications For Archean Supercratons, J. Salminen, E. P. Oliveira, Elisa J. Piispa, Aleksey Smirnov, R. I. F. Trindade

Michigan Tech Publications

The original connections of Archean cratons are becoming traceable due to an increasing amount of paleomagnetic data and refined magmatic barcodes. The Uauá block of the northern São Francisco craton may represent a fragment of a major Archean craton. Here, we report new paleomagnetic data from the 2.62 Ga Uauá tholeiitic mafic dyke swarm of the Uauá block in the northern São Francisco craton, Eastern Brazil. Our paleomagnetic results confirm the earlier results for these units, but our interpretation differs. We suggest that the obtained characteristic remanent magnetization for the 2.62 Ga swarm is of primary origin, supported by a …


Effective Exploitation Potential Of Shale Gas From Lower Cambrian Niutitang Formation, Northwestern Hunan, China, Han Cao, Tianyi Wang, Ting Bao, Pinghe Sun, Zheng Zhang, Jingjing Wu Dec 2018

Effective Exploitation Potential Of Shale Gas From Lower Cambrian Niutitang Formation, Northwestern Hunan, China, Han Cao, Tianyi Wang, Ting Bao, Pinghe Sun, Zheng Zhang, Jingjing Wu

Michigan Tech Publications

The marine shale in the Lower Cambrian Niutitang Formation is the dominant shale-gas reservoir in northwestern Hunan, which accounts for more than 70% of unconventional energy in Hunan province. Accurately evaluating the shale-gas exploitation potential is a key to determining whether commercial exploitation standards can be met. In the literature, most existing studies have focused on evaluating the shale-gas exploitation potential based on either accumulation conditions or the shale fracability, which will lead to a gap between the real production and proven gas reserves due to the characteristics of the shale’s low permeability and low porosity. Therefore, further studies are …


Investigative Study On Nitric Oxide Production In Human Dermal Fibroblast Cells Under Normal And High Glucose Conditions, Maria Paula Kwesiga, Emily Cook, Jennifer Hannon, Sarah Wayward, Caroline Gwaltney, Smitha Rao, Megan C. Frost Nov 2018

Investigative Study On Nitric Oxide Production In Human Dermal Fibroblast Cells Under Normal And High Glucose Conditions, Maria Paula Kwesiga, Emily Cook, Jennifer Hannon, Sarah Wayward, Caroline Gwaltney, Smitha Rao, Megan C. Frost

Michigan Tech Publications

Diabetic foot ulcers (DFU) are a major health problem associated with diabetes mellitus. Impaired nitric oxide (NO) production has been shown to be a major contributor to the dysregulation of healing in DFU. The level of impairment is not known primarily due to challenges with measuring NO. Herein, we report the actual level of NO produced by human dermal fibroblasts cultured under normal and high glucose conditions. Fibroblasts produce the extracellular matrix, which facilitate the migration of keratinocytes to close wounds. The results show that NO production was significantly higher in normal glucose compared to high glucose conditions. The real-time …


Reinforcement Learning-Based Multi-Auv Adaptive Trajectory Planning For Under-Ice Field Estimation, Chaofeng Wang, Li Wei, Zhaohui Wang, Min Song, Nina Mahmoudian Nov 2018

Reinforcement Learning-Based Multi-Auv Adaptive Trajectory Planning For Under-Ice Field Estimation, Chaofeng Wang, Li Wei, Zhaohui Wang, Min Song, Nina Mahmoudian

Michigan Tech Publications

This work studies online learning-based trajectory planning for multiple autonomous underwater vehicles (AUVs) to estimate a water parameter field of interest in the under-ice environment. A centralized system is considered, where several fixed access points on the ice layer are introduced as gateways for communications between the AUVs and a remote data fusion center. We model the water parameter field of interest as a Gaussian process with unknown hyper-parameters. The AUV trajectories for sampling are determined on an epoch-by-epoch basis. At the end of each epoch, the access points relay the observed field samples from all the AUVs to the …


Target Localization And Tracking By Fusing Doppler Differentials From Cellular Emanations With A Multi-Spectral Video Tracker, Casey D. Demars, Michael Roggemann, Adam Webb, Timothy C. Havens Oct 2018

Target Localization And Tracking By Fusing Doppler Differentials From Cellular Emanations With A Multi-Spectral Video Tracker, Casey D. Demars, Michael Roggemann, Adam Webb, Timothy C. Havens

Michigan Tech Publications

We present an algorithm for fusing data from a constellation of RF sensors detecting cellular emanations with the output of a multi-spectral video tracker to localize and track a target with a specific cell phone. The RF sensors measure the Doppler shift caused by the moving cellular emanation and then Doppler differentials between all sensor pairs are calculated. The multi-spectral video tracker uses a Gaussian mixture model to detect foreground targets and SIFT features to track targets through the video sequence. The data is fused by associating the Doppler differential from the RF sensors with the theoretical Doppler differential computed …


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 a …


First Observations Of Volcanic Eruption Clouds From The L1 Earth-Sun Lagrange Point By Dscovr/Epic, Simon Carn, N. A. Krotov, B. L. Fisher, C. Li, A. J. Prata Oct 2018

First Observations Of Volcanic Eruption Clouds From The L1 Earth-Sun Lagrange Point By Dscovr/Epic, Simon Carn, N. A. Krotov, B. L. Fisher, C. Li, A. J. Prata

Michigan Tech Publications

Volcanic sulfur dioxide (SO2) emissions have been measured by ultraviolet sensors on polar‐orbiting satellites for several decades but with limited temporal resolution. This precludes studies of key processes believed to occur in young (~1–3 hr old) volcanic clouds. In 2015, the launch of the Earth Polychromatic Imaging Camera (EPIC) aboard the Deep Space Climate Observatory (DSCOVR) provided an opportunity for novel observations of volcanic eruption clouds from the first Earth‐Sun Lagrange point (L1). The L1 vantage point provides continuous observations of the sunlit Earth, offering up to eight or nine observations of volcanic SO2 clouds in the …


Climbing The Crustal Ladder: Magma Storage-Depth Evolution During A Volcanic Flare-Up, Guilherme A. R. Gualda, Darren M. Gravley, Michelle Connor, Brooke Hollmann, Ayla S. Pamukcu, Florence Begue, Mark S. Ghiorso, Chad Deering Oct 2018

Climbing The Crustal Ladder: Magma Storage-Depth Evolution During A Volcanic Flare-Up, Guilherme A. R. Gualda, Darren M. Gravley, Michelle Connor, Brooke Hollmann, Ayla S. Pamukcu, Florence Begue, Mark S. Ghiorso, Chad Deering

Michigan Tech Publications

Very large eruptions (>50 km3) and supereruptions (>450 km3) reveal Earth’s capacity to produce and store enormous quantities (>1000 km3) of crystal-poor, eruptible magma in the shallow crust. We explore the interplay between crustal evolution and volcanism during a volcanic flare-up in the Taupo Volcanic Zone (TVZ, New Zealand) using a combination of quartz-feldspar-melt equilibration pressures and time scales of quartz crystallization. Over the course of the flare-up, crystallization depths became progressively shallower, showing the gradual conditioning of the crust. Yet, quartz crystallization times were invariably very short (<100 years), demonstrating that very large reservoirs of eruptible magma were transient crustal features. We conclude that the dynamic nature of the TVZ crust favored magma eruption over storage. Episodic tapping of eruptible magmas likely prevented a supereruption. Instead, multiple very large bodies of eruptible magma were assembled and erupted in decadal time scales.


Rheological Performance Of Bio-Char Modified Asphalt With Different Particle Sizes, Ran Zhang, Qingli Dai, Zhanping You, Hainian Wang, Chao Peng Sep 2018

Rheological Performance Of Bio-Char Modified Asphalt With Different Particle Sizes, Ran Zhang, Qingli Dai, Zhanping You, Hainian Wang, Chao Peng

Michigan Tech Publications

To improve the performance of petroleum asphalt, bio-char was used as a modifier for a petroleum asphalt binder, in this study. The rheological properties of bio-char modified asphalt binders were compared with different particle sizes and contents, with one control and one flake graphite modified asphalt binder. Specifically, the bio-char modifiers with two particle sizes (ranging from 75 μm–150 μm and less than 75 μm) and three contents of 2%, 4%, and 8% were added into the asphalt binder. A flake graphite powder with particle sizes less than 75 μm was used as a comparison modifier. The Scanning Electron Microscopy …


Coal With Carbon Capture And Sequestration Is Not As Land Use Efficient As Solar Photovoltaic Technology For Climate Neutral Electricity Production, James Gunnar Groesbeck, Joshua M. Pearce Sep 2018

Coal With Carbon Capture And Sequestration Is Not As Land Use Efficient As Solar Photovoltaic Technology For Climate Neutral Electricity Production, James Gunnar Groesbeck, Joshua M. Pearce

Michigan Tech Publications

Avoiding climate destabilization caused by greenhouse gas (GHG) emissions, requires climate-neutral electricity sources. It has been proposed that the GHG emissions from coal-fired power plants can be offset by carbon capture and sequestration or bio-sequestration. However, solar photovoltaic (PV) technology has recently declined so far in costs it now offers both technical and economic potential to offset all of coal-fired electricity use. PV only emits GHGs during fabrication and not during use. To determine which technical solution to climate-neutral electricity generation should be preferred, this study aggregates and synthesizes life cycle analysis studies for exergy, GHG emissions and land transformation …


Synthesis And Characterization Of Controlled Nitric Oxide Release From S-Nitroso-N-Acetyl-D-Penicillamine Covalently Linked To Polyvinyl Chloride (Snap-Pvc), Sean Hopkins, Megan C. Frost Sep 2018

Synthesis And Characterization Of Controlled Nitric Oxide Release From S-Nitroso-N-Acetyl-D-Penicillamine Covalently Linked To Polyvinyl Chloride (Snap-Pvc), Sean Hopkins, Megan C. Frost

Michigan Tech Publications

Polyvinyl chloride (PVC) is one of the most widely used polymers in medicine but has very poor biocompatibility when in contact with tissue or blood. To increase biocompatibility, controlled release of nitric oxide (NO) can be utilized to mitigate and reduce the inflammatory response. A synthetic route is described where PVC is aminated to a specified degree and then further modified by covalently linking S-nitroso-N-acetyl-d-penicillamine (SNAP) groups to the free primary amine sites to create a nitric oxide releasing polymer (SNAP-PVC). Controllable release of NO from SNAP-PVC is described using photoinitiation from light emitting diodes (LEDs). Ion-mediated NO release is …


Standardization Of Fatigue Characteristics Of Cement-Treated Aggregate Base Materials Under Different Stress States, Jiawei Xie, Limin Tang, Songtao Lv, Naitian Zhang, Tuo Huang, Hongfu Liu Sep 2018

Standardization Of Fatigue Characteristics Of Cement-Treated Aggregate Base Materials Under Different Stress States, Jiawei Xie, Limin Tang, Songtao Lv, Naitian Zhang, Tuo Huang, Hongfu Liu

Michigan Tech Publications

In this study, to decrease the evaluation uncertainty of the fatigue characteristics of cement-treated aggregate base materials under different test conditions, unconfined compressive, indirect tensile, flexural tensile strength tests and fatigue tests of these base materials with different cement content and at different curing times were carried out. The Weibull distribution was employed to analyze fatigue test results. The standardization model of fatigue characteristics for cement-treated aggregate base materials under different stress states was established. Based on the interval analysis theory, the fatigue characteristic model under different stress states was established using interval parameters. Results revealed that the curing time …


Landsliding Near Enguri Dam (Caucasus, Georgia) And Possible Seismoectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Davit Odilavadze Aug 2018

Landsliding Near Enguri Dam (Caucasus, Georgia) And Possible Seismoectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Davit Odilavadze

Michigan Tech Publications

The Enguri dam and water reservoir, nested in southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that involve a subaerial area of 1.2 km2. The head scarp interests the main Jvari-Khaishi-Mestia road with offset of man-made features that indicate slip rates of 2-9 cm/y. Static, pseudostatic and Newmark numerical analyses, based on field and seismological data, suggest different unstable rock volumes basing on the …


Slalom: An All-Surface Snow Water Path Retrieval Algorithm For The Gpm Microwave Imager, Jean-François Rysman, Giulia Panegrossi, Paolo Sanò, Anna Cinzia Marra, Stefano Dietrich, Lisa Milani, Mark S. Kulie Aug 2018

Slalom: An All-Surface Snow Water Path Retrieval Algorithm For The Gpm Microwave Imager, Jean-François Rysman, Giulia Panegrossi, Paolo Sanò, Anna Cinzia Marra, Stefano Dietrich, Lisa Milani, Mark S. Kulie

Michigan Tech Publications

This paper describes a new algorithm that is able to detect snowfall and retrieve the associated snow water path (SWP), for any surface type, using the Global Precipitation Measurement (GPM) Microwave Imager (GMI). The algorithm is tuned and evaluated against coincident observations of the Cloud Profiling Radar (CPR) onboard CloudSat. It is composed of three modules for (i) snowfall detection, (ii) supercooled droplet detection and (iii) SWP retrieval. This algorithm takes into account environmental conditions to retrieve SWP and does not rely on any surface classification scheme. The snowfall detection module is able to detect 83% of snowfall events including …


Energy Science And Engineering: Looking Ahead, Yun Hang Hu Aug 2018

Energy Science And Engineering: Looking Ahead, Yun Hang Hu

Michigan Tech Publications

No abstract provided.


Reverse Flotation Separation Of Fluorite From Calcite: A Novel Reagent Scheme, Jianjun Wang, Zihan Zhou, Yuesheng Gao, Wei Sun, Yuehua Hu, Zhiyong Gao Jul 2018

Reverse Flotation Separation Of Fluorite From Calcite: A Novel Reagent Scheme, Jianjun Wang, Zihan Zhou, Yuesheng Gao, Wei Sun, Yuehua Hu, Zhiyong Gao

Michigan Tech Publications

Fluorite (CaF2), as an important strategic mineral source, is usually separated from calcite by the common froth flotation method, but this separation is still not selective enough. The development of a selective collector and/or depressant is the key to achieving high selective separation. 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP or H4L) is widely used as an environmentally friendly water treatment reagent due to its low cost and excellent anti-scaling performance in an aqueous solution. In this study, a novel reagent scheme was developed using HEDP as a fluorite depressant and sodium oleate (NaOL) as a calcite collector for the …


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 fiber-plastic waste …


Optimal Multidimensional Droop Control For Wind Resources In Dc Microgrids, Kaitlyn J. Bunker, Wayne Weaver Jul 2018

Optimal Multidimensional Droop Control For Wind Resources In Dc Microgrids, Kaitlyn J. Bunker, Wayne Weaver

Michigan Tech Publications

The inclusion of electricity generation from wind in microgrids presents an important opportunity in modern electric power systems. Various control strategies can be pursued for wind resources connected in microgrids, and droop control is a promising option since communication between microgrid components is not required. Traditional droop control does have the drawback of not allowing much or all of the available wind power to be utilized in the microgrid. This paper presents a novel droop control strategy, modifying the traditional approach and building an optimal droop surface at a higher dimension. A method for determining the optimal droop control surface …


Nonlinear Fatigue Damage Of Cracked Cement Paste After Grouting Enhancement, Zhi Wang, Long Li, Shuaicheng Guo, Qingli Dai Jul 2018

Nonlinear Fatigue Damage Of Cracked Cement Paste After Grouting Enhancement, Zhi Wang, Long Li, Shuaicheng Guo, Qingli Dai

Michigan Tech Publications

Grouting reinforcement is an important part of modern engineering and has grown in popularity due to the benefits of grouting enhancement on cyclic loading. Understanding the fatigue mechanism of grouting-enhanced structures is vital to the design and the long-term stability analysis of such structures. In this study, the fatigue mechanical properties of cracked cement paste after epoxy resin grouting enhancement under different cyclic conditions were investigated in the laboratory and an inverted S-shaped curve was proposed to describe the damage accumulation. The test results indicated that the fatigue axial deformation can be divided into three stages: the initial stage, constant …


Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware, Joshua M. Pearce Jul 2018

Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware, Joshua M. Pearce

Michigan Tech Publications

As a growing number of companies reject intellectual property (IP) monopoly-based business models to embrace libre product development of free and open source hardware and software, there is an urgent need to refurbish the instruments of university-corporate research partnerships. These partnerships generally use a proprietary standard research agreement (PSRA), which for historical reasons contains significant IP monopoly language and restrictions for both the company and the university. Such standard research agreements thus create an artificial barrier to innovation as both companies using a libre model and universities they wish to collaborate with must invest significantly to restructure the contracts. To …


Effects Of Titanate Coupling Agent On Engineering Properties Of Asphalt Binders And Mixtures Incorporating Lldpe-Caco3 Pellet, Mohd Rosli Mohd Hasan, Zhanping You, Mohd Khairul Idham Mohd Satar, Muhammad Naqiuddin Mohd Warid, Nurul Hidayah Mohd Kamaruddin, Dongdong Ge, Ran Zhang Jun 2018

Effects Of Titanate Coupling Agent On Engineering Properties Of Asphalt Binders And Mixtures Incorporating Lldpe-Caco3 Pellet, Mohd Rosli Mohd Hasan, Zhanping You, Mohd Khairul Idham Mohd Satar, Muhammad Naqiuddin Mohd Warid, Nurul Hidayah Mohd Kamaruddin, Dongdong Ge, Ran Zhang

Michigan Tech Publications

This study was initiated to evaluate the performance of asphalt binders and mixtures incorporating linear low-density polyethylene- calcium carbonate (LLDPE-CaCO3) pellet, either with or without titanate coupling agent. The detailed manufacturing process of modifier pellets was displayed. The coupling agent was used to enhance the cross-linking between materials by means of winding up covalent bonds or molecule chains, thus improving the performance of composites. In the preparation of modified bitumen, the preheated asphalt binder was mixed with the modifiers using a high shear mixer at 5000 rpm rotational speed for 45 min. Experimental works were conducted to evaluate …


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

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

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

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

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

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

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 …


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

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 …


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

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

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 …