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2019

Iowa State University

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Articles 1 - 30 of 310

Full-Text Articles in Engineering

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil Dec 2019

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil

Mechanical Engineering Publications

Traumatic brain injuries (TBI) affect millions of people each year. While research has been dedicated to determining the mechanical properties of the uninjured brain, there has been a lack of investigation on the mechanical properties of the brain after experiencing a primary blast-induced TBI. In this paper, whole porcine brains were exposed to a shock wave to simulate blast-induced TBI. First, ten (10) brains were subjected to unconfined compression experiments immediately following shock wave exposure. In addition, 22 brains exposed to a shock wave were placed in saline solution and refrigerated between 30 minutes and 6.0 hours before undergoing ...


A Test System For Ercot Market Design Studies: Development And Application, Swathi Battula, Leigh Tesfatsion, Thomas E. Mcdermott Sep 2019

A Test System For Ercot Market Design Studies: Development And Application, Swathi Battula, Leigh Tesfatsion, Thomas E. Mcdermott

Economics Working Papers

The ERCOT Test System developed in this study permits dynamic performance evaluation of proposed new initiatives for the ERCOT energy region. The test system models ISO-managed day-ahead and real-time wholesale power markets operating over a transmission grid during successive simulated days. Market operations capture salient features of actual ERCOT market practices. Clustering and triangulation methods permit users to construct synthetic transmission grids with buses and lines configured in accordance with ERCOT generation, load, and grid data. A complete 8-bus ERCOT test case is developed and implemented to illustrate the capabilities of the test system. Ongoing studies making use of the ...


Engineering Measurements And Instrumentation: First Edition, Reza Montazami Sep 2019

Engineering Measurements And Instrumentation: First Edition, Reza Montazami

Open Textbooks

This electronic book (e-book) is created with partial financial support from a grant generously provided by the Miller Open Education Mini-Grant Program. This e-book is created as an open educational resource (OER) and it is meant to be used by students and educators for solely educational and non-commercial purposes.

This e-book is intended to be used as a complementary resource for engineering measurements and instrumentation course, at junior engineering level.

If you have any comments or suggestions, please reach out to the author via email: reza@iastate.edu


Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin Sep 2019

Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin

Agricultural and Biosystems Engineering Publications

The water vapor is a relevant greenhouse gas in the Earth's climate system, and satellite products become one of the most effective way to characterize and monitor the columnar water vapor (CWV) content at global scale. Recently, a new product (MCD19) was released as part of MODIS (Moderate Resolution Imaging Spectroradiometer) Collection 6 (C6). This operational product from Multi-Angle Implementation for Atmospheric Correction (MAIAC) algorithm includes a high 1 km resolution CWV retrievals. This study presents the first global validation of MAIAC C6 CWV obtained from MODIS MCD19A2 product. This evaluation was performed using Aerosol Robotic Network (AERONET) observations ...


At The Intersection Of Industry, Academia, And Government: How Do We Facilitate Productive Precision Livestock Farming In Practice?, Brett C. Ramirez, Hongwei Xin, Patrick G. Halbur, Donald H. Beermann, Stephanie L. Hansen, Daniel C. L. Linhares, Joshua M. Peschel, Christopher J. Rademacher, James M. Reecy, Jason W. Ross, Timothy A. Shepherd, James E. Koltes Aug 2019

At The Intersection Of Industry, Academia, And Government: How Do We Facilitate Productive Precision Livestock Farming In Practice?, Brett C. Ramirez, Hongwei Xin, Patrick G. Halbur, Donald H. Beermann, Stephanie L. Hansen, Daniel C. L. Linhares, Joshua M. Peschel, Christopher J. Rademacher, James M. Reecy, Jason W. Ross, Timothy A. Shepherd, James E. Koltes

Veterinary Diagnostic and Production Animal Medicine Publications

This commentary is a comprehensive synthesis of ideas generated from a workshop, hosted by Iowa State University, encompassing precision livestock farming (PLF) research and applications for industry–academia. The goal of this workshop was to demonstrate existing institution research and strategically propel further PLF development and industry adoption. Six key thematic areas were identified from participant discussion: sensors and algorithms, implementation, economic feasibility, data, rural and societal impacts, and education and training. These themes were used to focus discussion on identifying the new knowledge needed to drive implementation and examine current and future challenges of implementing PLF. At the convergence ...


Estimating Economic And Environmental Impacts Of Red-Wine-Making Processes In The Usa, Congmu Zhang, Kurt A. Rosentrater Aug 2019

Estimating Economic And Environmental Impacts Of Red-Wine-Making Processes In The Usa, Congmu Zhang, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

The goal of this study was to examine cost impacts using techno-economic analysis (TEA) and environmental impacts using life-cycle assessment (LCA) for the production of red wine. Three production scales, denoted as “small” (5000 gal per year), “medium” (50,000 gal per year), and “large” (500,000 gal per year) were chosen for analysis. For example, the consumption of water, energy, greenhouse gas emissions, and solid waste generation were considered in order to estimate environmental impacts. A spreadsheet-based economic model was also developed. The results of the LCA and TEA were compared amongst all production scales. The results of the ...


Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian Aug 2019

Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Background

Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide.

Results

Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D ...


Fatigue-Resistant High-Performance Elastocaloric Materials Via Additive Manufacturing, Huilong Hou, Emrah Simsek, Tao Ma, Nathan S. Johnson, Suxin Qian, Cheikh Cissé, Drew Stasak, Naila Al Hasan, Lin Zhou, Yunho Hwang, Reinhard Radermacher, Valery I. Levitas, Matthew J. Kramer, Mohsen Asle Zaeem, Aaron P. Stebner, Ryan T. Ott, Jun Cui, Ichiro Takeuchi Aug 2019

Fatigue-Resistant High-Performance Elastocaloric Materials Via Additive Manufacturing, Huilong Hou, Emrah Simsek, Tao Ma, Nathan S. Johnson, Suxin Qian, Cheikh Cissé, Drew Stasak, Naila Al Hasan, Lin Zhou, Yunho Hwang, Reinhard Radermacher, Valery I. Levitas, Matthew J. Kramer, Mohsen Asle Zaeem, Aaron P. Stebner, Ryan T. Ott, Jun Cui, Ichiro Takeuchi

Aerospace Engineering Publications

Elastocaloric cooling, which exploits the latent heat released and absorbed as stress-induced phase transformations are reversibly cycled in shape memory alloys, has recently emerged as a frontrunner in non-vapor-compression cooling technologies. The intrinsically high thermodynamic efficiency of elastocaloric materials is limited only by work hysteresis. Here, we report on creating high-performance low-hysteresis elastocaloric cooling materials via additive manufacturing of Titanium-Nickel (Ti-Ni) alloys. Contrary to established knowledge of the physical metallurgy of Ti-Ni alloys, intermetallic phases are found to be beneficial to elastocaloric performances when they are combined with the binary Ti-Ni compound in nanocomposite configurations. The resulting microstructure gives rise ...


Characterizing The Soil Microbiome And Quantifying Antibiotic Resistance Gene Dynamics In Agricultural Soil Following Swine Cafo Manure Application, Edward Lopatto, Jinlyung Choi, Alfredo Colina, Lanying Ma, Adina Howe, Shannon Hinsa-Leasure Aug 2019

Characterizing The Soil Microbiome And Quantifying Antibiotic Resistance Gene Dynamics In Agricultural Soil Following Swine Cafo Manure Application, Edward Lopatto, Jinlyung Choi, Alfredo Colina, Lanying Ma, Adina Howe, Shannon Hinsa-Leasure

Agricultural and Biosystems Engineering Publications

As agriculture industrializes, concentrated animal feeding operations (CAFOs) are becoming more common. Feces from CAFOs is often used as fertilizer on fields. However, little is known about the effects manure has on the soil microbiome, which is an important aspect of soil health and fertility. In addition, due to the subtherapeutic levels of antibiotics necessary to keep the animals healthy, CAFO manure has elevated levels of antibiotic resistant bacteria. Using 16s rRNA high-throughput sequencing and qPCR, this study sought to determine the impact of swine CAFO manure application on both the soil microbiome and abundance of select antibiotic resistance genes ...


Principal Component Neural Networks For Modeling, Prediction, And Optimization Of Hot Mix Asphalt Dynamics Modulus, Parnian Ghasemi, Mohamad Aslani, Derrick K. Rollins, R. Christopher Williams Aug 2019

Principal Component Neural Networks For Modeling, Prediction, And Optimization Of Hot Mix Asphalt Dynamics Modulus, Parnian Ghasemi, Mohamad Aslani, Derrick K. Rollins, R. Christopher Williams

Chemical and Biological Engineering Publications

The dynamic modulus of hot mix asphalt (HMA) is a fundamental material property that defines the stress-strain relationship based on viscoelastic principles and is a function of HMA properties, loading rate, and temperature. Because of the large number of efficacious predictors (factors) and their nonlinear interrelationships, developing predictive models for dynamic modulus can be a challenging task. In this research, results obtained from a series of laboratory tests including mixture dynamic modulus, aggregate gradation, dynamic shear rheometer (on asphalt binder), and mixture volumetric are used to create a database. The created database is used to develop a model for estimating ...


Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu Aug 2019

Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu

Mechanical Engineering Conference Presentations, Papers, and Proceedings

The objective of this work is to computationally investigate the impact of an incident-tolerant rotor blade concept on gas-turbine engine performance under off-design conditions. Currently, gas-turbine engines are designed to operate at a single condition with nearly fixed rotor speeds. Operation at off-design conditions, such as during hover flight or during takeoff, causes the turbine blade flow to excessively separate introducing performance degradations, excessive noise, and critical loss of operability. To address these issues, the benefits of using an incidence-tolerant rotor blade concept is explored based on a novel concept that articulates the rotating turbine blade synchronously with the stator ...


Sheet‐Extruded Films From Blends Of Hydroxypropylated And Native Corn Starches, And Their Characterization, Hee-Young Kim, Buddhi P. Lamsal, Jay-Lin Jane, David A. Grewell Aug 2019

Sheet‐Extruded Films From Blends Of Hydroxypropylated And Native Corn Starches, And Their Characterization, Hee-Young Kim, Buddhi P. Lamsal, Jay-Lin Jane, David A. Grewell

Food Science and Human Nutrition Publications

Sheet‐extruded films from the blends of hydroxypropylated normal corn starch (HP) and native normal corn starch (NS) at weight ratios of 100:0, 90:10, 70:30, 50:50, 30:70, and 0:100 were prepared and characterized. Glycerol and water were added as plasticizers at 11 and 27% starch weight, respectively. The highest tensile strength (TS) and longest elongation to break (EB) for dry films were observed at 70:30 HP: NS ratio, which was 25.76 MPa, and 3.97%, respectively. However, TS and EB of this 70:30 blend extruded starch film exhibited low resistance upon ...


Design Thinking: An Approach With Various Perceptions, Sanne Bouwman, Jesper Voorendt, Boris Eisenbart, Seda Mckilligan Aug 2019

Design Thinking: An Approach With Various Perceptions, Sanne Bouwman, Jesper Voorendt, Boris Eisenbart, Seda Mckilligan

Industrial Design Conference Presentations, Posters and Proceedings

Design Thinking has become increasingly popular across different disciplines. However, what it exactly entails is becoming more and more vague, leading to the term being used for many different approaches and applications. This paper presents an interview study with experts on the application and training of Design Thinking in academia and industry. We find a divide with some seeing Design Thinking as a mere toolbox of methods, while others see it as an umbrella term for the mindset that determines how designers think and act. Subjects unanimously attest the approach large potential to support certain types of businesses, when applied ...


Polyurethane-Carbon Microfiber Composite Coating For Electrical Heating Of Concrete Pavement Surfaces, Alireza Sassani, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Kasthurirangan Gopalakrishnan, Peter C. Taylor, Ali Nahvi Aug 2019

Polyurethane-Carbon Microfiber Composite Coating For Electrical Heating Of Concrete Pavement Surfaces, Alireza Sassani, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Kasthurirangan Gopalakrishnan, Peter C. Taylor, Ali Nahvi

Civil, Construction and Environmental Engineering Publications

Electrically-heated pavements have attracted attention as alternatives to the traditional ice/snow removal practices. Electrically conductive polymer-carbon composite coatings provide promising properties for this application. Based on the concept of joule heating, the conductive composite can be utilized as a resistor that generates heat by electric current and increases the surface temperature to melt the ice and snow on the pavement surface. This research investigates the feasibility of applying an electrically conductive composite coating made with a Polyurethane (PU) binder and micrometer-scale carbon fiber (CMF) filler as the electrical heating materials on the surface of Portland cement concrete (PCC) pavements ...


Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen Aug 2019

Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen

Mechanical Engineering Publications

A multi-step approach is described for the fabrication of multi-layer graphene-based electrodes without the need for ink binders or post-print annealing. Graphite and nanoplatelet graphene were chemically exfoliated using a modified Hummers’ method and the dried material was thermally expanded. Expanded materials were used in a 3D printed mold and stamp to create laminate electrodes on various substrates. The laminates were examined for potential sensing applications using model systems of peroxide (H2O2) and enzymatic glucose detection. Within the context of these two assay systems, platinum nanoparticle electrodeposition and oxygen plasma treatment were examined as methods for improving sensitivity. Electrodes made ...


Evaluating Machine Learning Performance In Predicting Injury Severity In Agribusiness Industries, Fatemeh Davoudi Kakhki, Steven A. Freeman, Gretchen A. Mosher Aug 2019

Evaluating Machine Learning Performance In Predicting Injury Severity In Agribusiness Industries, Fatemeh Davoudi Kakhki, Steven A. Freeman, Gretchen A. Mosher

Agricultural and Biosystems Engineering Publications

Although machine learning methods have been used as an outcome prediction tool in many fields, their utilization in predicting incident outcome in occupational safety is relatively new. This study tests the performance of machine learning techniques in modeling and predicting occupational incidents severity with respect to accessible information of injured workers in agribusiness industries using workers’ compensation claims. More than 33,000 incidents within agribusiness industries in the Midwest of the United States for 2008–2016 were analyzed. The total cost of incidents was extracted and classified from workers’ compensation claims. Supervised machine learning algorithms for classification (support vector machines ...


Capacitance-Based Sensor With Layered Carbon-Fiber Reinforced Polymer And Titania-Filled Epoxy, Jin Yan, Austin Downey, An Chen, Simon Laflamme, Sammy Hassan Jul 2019

Capacitance-Based Sensor With Layered Carbon-Fiber Reinforced Polymer And Titania-Filled Epoxy, Jin Yan, Austin Downey, An Chen, Simon Laflamme, Sammy Hassan

Civil, Construction and Environmental Engineering Publications

Advances in intelligent infrastructure can be achieved through the use of novel materials for increased system-level efficiency and multifunctionality. Carbon Fiber-Reinforced Polymer (CFRP) has been widely used in strengthening, rehabilitating, and retrofitting of existing structures because of its speed of deployment, low maintenance requirement, and high strength-to-weight ratio. In this work, the authors propose a novel method to augment CFRP with self-sensing capabilities. The sensor consists of two CFRP layers separated by a titania-filled epoxy dielectric layer, therefore forming a parallel plate capacitor. Sensing capability can be achieved through variations in the sensor’s capacitance provoked by strain, therefore providing ...


Development Of Optimized Phenomic Predictors For Efficient Plant Breeding Decisions Using Phenomic-Assisted Selection In Soybean, Kyle Parmley, Koushik Nagasubramanian, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh Jul 2019

Development Of Optimized Phenomic Predictors For Efficient Plant Breeding Decisions Using Phenomic-Assisted Selection In Soybean, Kyle Parmley, Koushik Nagasubramanian, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh

Mechanical Engineering Publications

The rate of advancement made in phenomic-assisted breeding methodologies has lagged those of genomic-assisted techniques, which is now a critical component of mainstream cultivar development pipelines. However, advancements made in phenotyping technologies have empowered plant scientists with affordable high-dimensional datasets to optimize the operational efficiencies of breeding programs. Phenomic and seed yield data was collected across six environments for a panel of 292 soybean accessions with varying genetic improvements. Random forest, a machine learning (ML) algorithm, was used to map complex relationships between phenomic traits and seed yield and prediction performance assessed using two cross-validation (CV) scenarios consistent with breeding ...


Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada Jul 2019

Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada

Chemical and Biological Engineering Publications

In this study, a novel method based on the transfer of graphene patterns from a rigid or flexible substrate onto a polymeric film surface via solvent casting was developed. The method involves the creation of predetermined graphene patterns on the substrate, casting a polymer solution, and directly transferring the graphene patterns from the substrate to the surface of the target polymer film via a peeling-off method. The feature sizes of the graphene patterns on the final film can vary from a few micrometers (as low as 5 µm) to few millimeters range. This process, applied at room temperature, eliminates the ...


Continuous Monitoring Of Soil Nitrate Using A Miniature Sensor With Poly(3-Octyl-Thiophene) And Molybdenum Disulfide Nanocomposite, Md. Azahar Ali, Xinran Wang, Yuncong Chen, Yueyi Jiao, Navreet K. Mahal, Satyanarayana Moru, Michael J. Castellano, James C. Schnable, Patrick S. Schnable, Liang Dong Jul 2019

Continuous Monitoring Of Soil Nitrate Using A Miniature Sensor With Poly(3-Octyl-Thiophene) And Molybdenum Disulfide Nanocomposite, Md. Azahar Ali, Xinran Wang, Yuncong Chen, Yueyi Jiao, Navreet K. Mahal, Satyanarayana Moru, Michael J. Castellano, James C. Schnable, Patrick S. Schnable, Liang Dong

Agronomy Publications

There is an unmet need for improved fertilizer management in agriculture. Continuous monitoring of soil nitrate would address this need. This paper reports an all-solid-state miniature potentiometric soil sensor that works in direct contact with soils to monitor nitrate-nitrogen (NO3--N) in soil solution with parts-per-million (ppm) resolution. A working electrode is formed from a novel nanocomposite of poly(3-octyl-thiophene) and molybdenum disulfide (POT–MoS2) coated on a patterned Au electrode and covered with a nitrate-selective membrane using a robotic dispenser. The POT–MoS2 layer acts as an ion-to-electron transducing layer with high hydrophobicity and redox properties. The modification of the ...


Proof-Of-The-Concept Of Spent Mushrooms Compost Torrefaction - Preliminary Studies Of Process Kinetics And The Influence Of Temperature And Duration On Calorific Value Of The Biochar, Ewa Syguła, Jacek A. Koziel, Andrzej Białowiec Jul 2019

Proof-Of-The-Concept Of Spent Mushrooms Compost Torrefaction - Preliminary Studies Of Process Kinetics And The Influence Of Temperature And Duration On Calorific Value Of The Biochar, Ewa Syguła, Jacek A. Koziel, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

Poland is the 3rd producer of mushrooms in the world. Mushroom production in Poland accounts for nearly 25% of the total production in the EU, and it is still growing. One type of waste generated during mushroom production is mushroom spent compost (MSC), with a 5:1 (MSC: mushrooms) production rate. We investigated valorizing the MSC to produce fuel via torrefaction (‘roasting’, a.k.a. low-temperature pyrolysis). Specifically, we developed models for the MSC torrefaction kinetics using thermogravimetric analyses (TGA) and the effects of torrefaction temperature (200~300 °C) and process duration time (20~60 min) on the resulting biochar ...


Immersogeometric Analysis Of Moving Objects In Incompressible Flows, Songzhe Xu, Fei Xu, Aditya Kommajosula, Ming-Chen Hsu, Baskar Ganapathysubramanian Jul 2019

Immersogeometric Analysis Of Moving Objects In Incompressible Flows, Songzhe Xu, Fei Xu, Aditya Kommajosula, Ming-Chen Hsu, Baskar Ganapathysubramanian

Mechanical Engineering Publications

We deploy the immersogeometric approach for tracking moving objects. The method immerses objects into non-boundary-fitted meshes and weakly enforces Dirichlet boundary conditions on the object boundaries. The object motion is driven by the integrated surface force and external body forces. A residual-based variational multiscale method is employed to stabilize the finite element formulation for incompressible flows. Adaptively refined quadrature rules are used to better capture the geometry of the immersed boundaries by accurately integrating the intersected background elements. Treatment for the freshly-cleared nodes (i.e. background mesh nodes that are inside the object at one time step, but are in ...


Satisfiability Checking For Mission-Time Ltl, Jianwen Li, Moshe Y. Vardi, Kristin Y. Rozier Jul 2019

Satisfiability Checking For Mission-Time Ltl, Jianwen Li, Moshe Y. Vardi, Kristin Y. Rozier

Aerospace Engineering Publications

Mission-time LTL (MLTL) is a bounded variant of MTL over naturals designed to generically specify requirements for mission-based system operation common to aircraft, spacecraft, vehicles, and robots. Despite the utility of MLTL as a specification logic, major gaps remain in analyzing MLTL, e.g., for specification debugging or model checking, centering on the absence of any complete MLTL satisfiability checker. We prove that the MLTL satisfiability checking problem is NEXPTIME-complete and that satisfiability checking MLTL0 , the variant of MLTL where all intervals start at 0, is PSPACE-complete. We introduce translations for MLTL-to-LTL, MLTL-to-LTLf , MLTL-to-SMV, and MLTL-to-SMT, creating four ...


Oxytree Pruned Biomass Torrefaction: Mathematical Models Of The Influence Of Temperature And Residence Time On Fuel Properties Improvement, Kacper Świechowski, Marek Liszewski, Przemysław Bąbelewski, Jacek A. Koziel, Andrzej Białowiec Jul 2019

Oxytree Pruned Biomass Torrefaction: Mathematical Models Of The Influence Of Temperature And Residence Time On Fuel Properties Improvement, Kacper Świechowski, Marek Liszewski, Przemysław Bąbelewski, Jacek A. Koziel, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

Biowaste generated in the process of Oxytree cultivation and logging represents a potential source of energy. Torrefaction (a.k.a. low-temperature pyrolysis) is one of the methods proposed for the valorization of woody biomass. Still, energy is required for the torrefaction process during which the raw biomass becomes torrefied biomass with fuel properties similar to those of lignite coal. In this work, models describing the influence of torrefaction temperature and residence time on the resulting fuel properties (mass and energy yields, energy densification ratio, organic matter and ash content, combustible parts, lower and higher heating values, CHONS content, H:C ...


Ambient Synthesis Of Nanomaterials By In Situ Heterogeneous Metal/Ligand Reactions, Boyce S. Chang, Brijith Thomas, Jiahao Chen, Ian D. Tevis, Paul Karanja, Simge Çınar, Amrit Venkatesh, Aaron Rossini, Martin M. Thuo Jul 2019

Ambient Synthesis Of Nanomaterials By In Situ Heterogeneous Metal/Ligand Reactions, Boyce S. Chang, Brijith Thomas, Jiahao Chen, Ian D. Tevis, Paul Karanja, Simge Çınar, Amrit Venkatesh, Aaron Rossini, Martin M. Thuo

Ames Laboratory Accepted Manuscripts

Coordination polymers are ideal synthons in creating high aspect ratio nanostructures, however, conventional synthetic methods are often restricted to batch-wise and costly processes. Herein, we demonstrate a non-traditional, frugal approach to synthesize 1D coordination polymers by in situ etching of zerovalent metal particle precursors. This procedure is denoted as the heterogeneous metal/ligand reaction and was demonstrated on Group 13 metals as a proof of concept. Simple carboxylic acids supply the etchant protons and ligands for metal ions (conjugate base) in a 1 : 1 ratio. This scalable reaction produces a 1D polymer that assembles into high-aspect ratio ‘nanobeams’. We demonstrate ...


Mindset For Software Architecture Students, Lotfi Ben Othmane, Monica H. Lamm Jul 2019

Mindset For Software Architecture Students, Lotfi Ben Othmane, Monica H. Lamm

Electrical and Computer Engineering Conference Papers, Posters and Presentations

Software architecture students need to believe that they can change their abilities in order to become proficient with software architecture design. Addressing students’ beliefs about their capabilities introduces the realm of mindset. This paper reports about a survey that we conducted in a large university to study a set of factors associated with the students’ mindset. The study found that the students’ mindsets weakly correlates with their cognitive levels and are associated with their expectations from the course. In addition, it found that the students who prefer practicing software architecture have more open mindset than the ones who prefer quizzes ...


Identification Of The Impacts Of Code Changes On The Security Of Software, Moataz Abdelkhalek, Ameerah-Muhsina Jamil, Lotfi Ben Othmane Jul 2019

Identification Of The Impacts Of Code Changes On The Security Of Software, Moataz Abdelkhalek, Ameerah-Muhsina Jamil, Lotfi Ben Othmane

Electrical and Computer Engineering Conference Papers, Posters and Presentations

Companies develop their software in versions and iterations. Ensuring the security of each additional version using code review is costly and time consuming. This paper investigates automated tracing of the impacts of code changes on the security of a given software. To this end, we use call graphs to model the software code, and security assurance cases to model the security requirements of the software. Then we relate assurance case elements to code through the entry point methods of the software, creating a map of monitored security functions. This mapping allows to evaluate the security requirements that are affected by ...


Interplay Between Superconductivity And Itinerant Magnetism In Underdoped Ba1−Xkxfe2as2 (X = 0.2) Probed By The Response To Controlled Point-Like Disorder, Ruslan Prozorov, Marcin Kończykowski, Makariy A. Tanatar, Hai-Hu Wen, Rafael M. Fernandes, Paul C. Canfield Jul 2019

Interplay Between Superconductivity And Itinerant Magnetism In Underdoped Ba1−Xkxfe2as2 (X = 0.2) Probed By The Response To Controlled Point-Like Disorder, Ruslan Prozorov, Marcin Kończykowski, Makariy A. Tanatar, Hai-Hu Wen, Rafael M. Fernandes, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

The response of superconductors to controlled introduction of point-like disorder is an important tool to probe their microscopic electronic collective behavior. In the case of iron-based superconductors, magnetic fluctuations presumably play an important role in inducing high-temperature superconductivity. In some cases, these two seemingly incompatible orders coexist microscopically. Therefore, understanding how this unique coexistence state is affected by disorder can provide important information about the microscopic mechanisms involved. In one of the most studied pnictide family, hole-doped Ba1−xKxFe2As2 (BaK122), this coexistence occurs over a wide range of doping levels, 0.16 ≲ x ≲ 0.25. We used ...


Quantifying Repeatability Reproducibility Sources Of Error And Capacity Of A Measurement: Demonstrated Using Laboratory Soil Plasticity Tests, Cheng Li, Jeramy C. Ashlock, Xuhao Wang Jul 2019

Quantifying Repeatability Reproducibility Sources Of Error And Capacity Of A Measurement: Demonstrated Using Laboratory Soil Plasticity Tests, Cheng Li, Jeramy C. Ashlock, Xuhao Wang

Civil, Construction and Environmental Engineering Publications

The repeatability, reproducibility, and sources of error inherent in a given measurement are important considerations for potential users. To quantify errors arising from a single operator or multiple laboratories, most testing standards uses a one-way analysis of variance- (ANOVA-) based method, which utilizes a simple standard deviation across all measurements. However, this method does not allow users to quantify the sources of error and capacity (i.e., the precision to tolerance ratio). In this study, an innovative two-way ANOVA-based analysis method is selected to quantify the relative contributions of different sources of error and determine whether a measurement can be ...


Techno-Economic Analysis (Tea) And Life Cycle Assessment (Lca) Of Maize Storage For Small And Middle Sized Farmers, Rashid Suleiman, Kurt A. Rosentrater Jul 2019

Techno-Economic Analysis (Tea) And Life Cycle Assessment (Lca) Of Maize Storage For Small And Middle Sized Farmers, Rashid Suleiman, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

Maize is the most widely cultivated cereal crop worldwide, currently ranked the third most important crop globally after wheat and rice. It is a key staple food in many developing countries. However, maize is produced on a seasonal basis, usually harvest once per year. To maintain a constant supply throughout the year, maize should be properly stored. But this may entail high cost and high-energy consumption, which can contribute significant amounts of greenhouse gas emissions. In this study, three storage capacities (25,000 bu, 250,000 bu and 2,500,000 bu) of maize were evaluated for economic analysis and ...