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Full-Text Articles in Engineering
Optimal Molecular Dynamics System Size For Increased Precision And Efficiency For Epoxy Materials, Khatereh Kashmari, Sagar Patil, Josh Kemppainen, Shankara Gowtham, Gregory Odegard
Optimal Molecular Dynamics System Size For Increased Precision And Efficiency For Epoxy Materials, Khatereh Kashmari, Sagar Patil, Josh Kemppainen, Shankara Gowtham, Gregory Odegard
Michigan Tech Publications, Part 2
Molecular dynamics (MD) simulation is an important tool for predicting thermo-mechanical properties of polymer resins at the nanometer length scale, which is particularly important for efficient computationally driven design of advanced composite materials and structures. Because of the statistical nature of modeling amorphous materials on the nanometer length scale, multiple MD models (replicates) are typically built and simulated for statistical sampling of predicted properties. Larger replicates generally provide higher precision in the predictions but result in higher simulation times. Unfortunately, there is insufficient information in the literature to establish guidelines between MD model size and the resulting precision in predicted …
Deciphering The Controlling Factors For Phase Transitions In Zeolitic Imidazolate Frameworks, Tao Du, Shanwu Li, Sudheer Ganisetti, Mathieu Bauchy, Yuanzheng Yue, Morten M. Smedskjaer
Deciphering The Controlling Factors For Phase Transitions In Zeolitic Imidazolate Frameworks, Tao Du, Shanwu Li, Sudheer Ganisetti, Mathieu Bauchy, Yuanzheng Yue, Morten M. Smedskjaer
Michigan Tech Publications, Part 2
Zeolitic imidazolate frameworks (ZIFs) feature complex phase transitions, including polymorphism, melting, vitrification, and polyamorphism. Experimentally probing their structural evolution during transitions involving amorphous phases is a significant challenge, especially at the medium-range length scale. To overcome this challenge, here we first train a deep learning-based force field to identify the structural characteristics of both crystalline and non-crystalline ZIF phases. This allows us to reproduce the structural evolution trend during the melting of crystals and formation of ZIF glasses at various length scales with an accuracy comparable to that of ab initio molecular dynamics, yet at a much lower computational cost. …
Characterization Of Oscillatory Response Of Light-Weight Wind Turbine Rotors Under Controlled Gust Pulses, Fernando Ponta, Alayna Farrell, Apurva Baruah, North Yates
Characterization Of Oscillatory Response Of Light-Weight Wind Turbine Rotors Under Controlled Gust Pulses, Fernando Ponta, Alayna Farrell, Apurva Baruah, North Yates
Michigan Tech Publications, Part 2
Given the industry-wide trend of continual increases in the size of utility-scale wind turbines, a point will come where reductions will need to be made in terms of the weight of the turbine’s blades to ensure they can be as long as needed without sacrificing structural stability. One such technique that may be considered is to decrease the material used for the shell and spar cap. While this will solve the weight issue, it creates a new one entirely—less material for the shell and spar cap will in turn create blades that are more flexible than what is currently used. …
Increasing The Dissolution Rate Of Polystyrene Waste In Solvent-Based Recycling, Rita Kol, Ruben Denolf, Gwendoline Bernaert, Dave Manhaeghe, Ezra Bar Ziv, George W. Huber, Norbert Niessner, Michiel Verswyvel, Angeliki Lemonidou, Dimitris S. Achilias, Steven De Meester
Increasing The Dissolution Rate Of Polystyrene Waste In Solvent-Based Recycling, Rita Kol, Ruben Denolf, Gwendoline Bernaert, Dave Manhaeghe, Ezra Bar Ziv, George W. Huber, Norbert Niessner, Michiel Verswyvel, Angeliki Lemonidou, Dimitris S. Achilias, Steven De Meester
Michigan Tech Publications, Part 2
Solvent-based recycling of plastic waste is a promising approach for cleaning polymer chains without breaking them. However, the time required to actually dissolve the polymer in a lab environment can take hours. Different factors play a role in polymer dissolution, including temperature, turbulence, and solvent properties. This work provides insights into bottlenecks and opportunities to increase the dissolution rate of polystyrene in solvents. The paper starts with a broad solvent screening in which the dissolution times are compared. Based on the experimental results, a multiple regression model is constructed, which shows that within several solvent properties, the viscosity of the …
Experimental Investigation Of Long-Term Performance Of Fiber-Reinforced Epoxy And Polyurethane Polymer Composites, Abdel Hamid I. Mourad, Amir Hussain Idrisi, Asima Zahoor, Muhammad M. Sherif, Beckry M. Abdel-Magid
Experimental Investigation Of Long-Term Performance Of Fiber-Reinforced Epoxy And Polyurethane Polymer Composites, Abdel Hamid I. Mourad, Amir Hussain Idrisi, Asima Zahoor, Muhammad M. Sherif, Beckry M. Abdel-Magid
Michigan Tech Publications, Part 2
The primary challenge encountered by polymers and their composites when exposed to saline water is their inadequate ability to withstand wear and tear over time. With a potential to replace conventional materials the long-term performance of FRP composites is still a novice area. This manuscript thus, reports an experimental investigation and prediction of the durability of fiber-reinforced polymer composites exposed to seawater at different temperatures. E-glass/epoxy and E-glass/polyurethane samples were exposed to 23 °C, 45 °C and 65 °C seawater for up to 2700 days (90 months). Tensile tests evaluated the mechanical performance of the composite as a function of …
Simulation Of The Multi-Wake Evolution Of Two Sandia National Labs/National Rotor Testbed Turbines Operating In A Tandem Layout, Apurva Baruah, Fernando L. Ponta, Alayna Farrell
Simulation Of The Multi-Wake Evolution Of Two Sandia National Labs/National Rotor Testbed Turbines Operating In A Tandem Layout, Apurva Baruah, Fernando L. Ponta, Alayna Farrell
Michigan Tech Publications, Part 2
The future of wind power systems deployment is in the form of wind farms comprised of scores of such large turbines, most likely at offshore locations. Individual turbines have grown in span from a few tens of meters to today’s large turbines with rotor diameters that dwarf even the largest commercial aircraft. These massive dynamical systems present unique challenges at scales unparalleled in prior applications of wind science research. Fundamental to this effort is the understanding of the wind turbine wake and its evolution. Furthermore, the optimization of the entire wind farm depends on the evolution of the wakes of …
Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han
Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han
Michigan Tech Publications, Part 2
Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction-a measure of …
Analysis Of Wind Turbine Wake Dynamics By A Gaussian-Core Vortex Lattice Technique, Apurva Baruah, Fernando L. Ponta
Analysis Of Wind Turbine Wake Dynamics By A Gaussian-Core Vortex Lattice Technique, Apurva Baruah, Fernando L. Ponta
Michigan Tech Publications, Part 2
The development and deployment of the next generation of wind energy systems calls for simulation tools that model the entire wind farm while balancing accuracy and computational cost. A full-system wind farm simulation must consider the atmospheric inflow, the wakes and consequent response of the multiple turbines, and the implementation of the appropriate farm-collective control strategies that optimize the entire wind farm’s output. In this article, we present a novel vortex lattice model that enables the effective representation of the complex vortex wake dynamics of the turbines in a farm subject to transient inflow conditions. This work extends the capabilities …
Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish K. Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han
Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish K. Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han
Michigan Tech Publications, Part 2
Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction—a measure of …
Polymerizing Actin Regulates Myosin-Independent Mechanosensing By Modulating Actin Elasticity And Flow Fluctuation, Nikhil Mittal, Etienne Michels, Kathleen Pakenas, Shaina P. Royer-Weeden, Sangyoon J. Han
Polymerizing Actin Regulates Myosin-Independent Mechanosensing By Modulating Actin Elasticity And Flow Fluctuation, Nikhil Mittal, Etienne Michels, Kathleen Pakenas, Shaina P. Royer-Weeden, Sangyoon J. Han
Michigan Tech Publications, Part 2
The stiffness of the extracellular matrix induces differential tension within integrin-based adhesions. However, it has been unclear if the stiffness-dependent differential tension is induced solely by myosin activity. Here, we report that in the absence of myosin contractility, 3T3 fibroblasts still transmit stiffness-dependent differential levels of traction. This myosin-independent differential traction is regulated by polymerizing actin assisted by actin nucleators Arp2/3 and formin where formin has stronger contribution than Arp2/3. Interestingly, we report a four-fold reduction in traction of cells when both Arp2/3 and myosin were inhibited, compared to cells with only myosin inhibition, while there was only a slight …
Myosin-Independent Stiffness Sensing By Fibroblasts Is Regulated By The Viscoelasticity Of Flowing Actin, Nikhil Mittal, Etienne B. Michels, Andrew E. Massey, Yunxiu Qiu, Shaina P. Royer-Weeden, Bryan R. Smith, Alexander X. Cartagena-Rivera, Sangyoon J. Han
Myosin-Independent Stiffness Sensing By Fibroblasts Is Regulated By The Viscoelasticity Of Flowing Actin, Nikhil Mittal, Etienne B. Michels, Andrew E. Massey, Yunxiu Qiu, Shaina P. Royer-Weeden, Bryan R. Smith, Alexander X. Cartagena-Rivera, Sangyoon J. Han
Michigan Tech Publications, Part 2
The stiffness of the extracellular matrix induces differential tension within integrin-based adhesions, triggering differential mechanoresponses. However, it has been unclear if the stiffness-dependent differential tension is induced solely by myosin activity. Here, we report that in the absence of myosin contractility, 3T3 fibroblasts still transmit stiffness-dependent differential levels of traction. This myosin-independent differential traction is regulated by polymerizing actin assisted by actin nucleators Arp2/3 and formin where formin has a stronger contribution than Arp2/3 to both traction and actin flow. Intriguingly, despite only slight changes in F-actin flow speed observed in cells with the combined inhibition of Arp2/3 and myosin …
Radiation Force Modeling For A Wave Energy Converter Array, Salman Husain, Gordon Parker, David Forehand, Enrico Anderlini
Radiation Force Modeling For A Wave Energy Converter Array, Salman Husain, Gordon Parker, David Forehand, Enrico Anderlini
Michigan Tech Publications, Part 2
The motivation and focus of this work is to generate passive transfer function matrices that model the radiation forces for an array of WECs. Multivariable control design is often based on linear time-invariant (LTI) systems such as state-space or transfer function matrix models. The intended use is for designing real-time control strategies where knowledge of the model’s poles and zeros is helpful. This work presents a passivity-based approach to estimate radiation force transfer functions that accurately replace the convolution operation in the Cummins equation while preserving the physical properties of the radiation function. A two-stage numerical optimization approach is used, …