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Articles 1 - 30 of 16280

Full-Text Articles in Engineering

Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong Feb 2019

Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong

Aerospace Engineering Publications

In this paper, molecular dynamics (MD) simulations of the interaction between tilt grain boundaries (GBs) and a shuffle screw dislocation in silicon are performed. Results show that dislocations transmit into the neighboring grain for all GBs in silicon. For Σ3, Σ9 and Σ19 GBs, when a dislocation interacts with a heptagon site, it transmits the GB directly. In contrast, when interacting with a pentagon site, it first cross slips to a plane on the heptagon site and then transmits the GB. The energy barrier is also quantified using the climbing image nudged elastic band (CINEB) method. Results show that Σ3 ...


Critical Analysis Of Case Law: Are Partnering Charters Binding?, Milagros Pinto Nunez, Douglas D. Gransberg Feb 2019

Critical Analysis Of Case Law: Are Partnering Charters Binding?, Milagros Pinto Nunez, Douglas D. Gransberg

Civil, Construction and Environmental Engineering Publications

Construction project partnering in the United States has been used successfully for nearly 30 years in reducing disputes. Most partnered projects are characterized by the joint development of a nonbinding partnering charter between the owner and the contractor, which encapsulates the project’s goals and lays out the desired process for resolving issues at the lowest level. This paper explores the outcomes when partnered projects fail and the parties involved must turn to the courts to settle their disputes. The paper evaluates the case law for 16 partnered projects through content analysis and cross-case comparison. The paper explores the question ...


Validating The Opa Cascading Blackout Model On A 19402 Bus Transmission Network With Both Mesh And Tree Structures, Benjamin A. Carreras, Jose M. Reynolds-Barredo, Ian Dobson, David E. Newman Jan 2019

Validating The Opa Cascading Blackout Model On A 19402 Bus Transmission Network With Both Mesh And Tree Structures, Benjamin A. Carreras, Jose M. Reynolds-Barredo, Ian Dobson, David E. Newman

Electrical and Computer Engineering Conference Papers, Posters and Presentations

The OPA model calculates the long-term risk of cascading blackouts by simulating cascading outages and the slow process of network upgrade in response to blackouts. We validate OPA on a detailed 19402 bus network model of the Western Electricity Coordinating Council (WECC) interconnection with publicly available data. To do this, we examine scalings on a series of WECC interconnection models with increasing detail. The most detailed, 19402 bus network has more tree structures at the edges of the main mesh structure, and we extend the OPA model to account for this. The higher-risk cascading outages are the large cascades that ...


Thin-Film Sensor For Fatigue Crack Sensing And Monitoring In Steel Bridges Under Varying Crack Propagation Rates And Random Traffic Loads, Xiangxiong Kong, Jian Li, Caroline Bennett, William Collins, Simon Laflamme, Hongki Jo Jan 2019

Thin-Film Sensor For Fatigue Crack Sensing And Monitoring In Steel Bridges Under Varying Crack Propagation Rates And Random Traffic Loads, Xiangxiong Kong, Jian Li, Caroline Bennett, William Collins, Simon Laflamme, Hongki Jo

Civil, Construction and Environmental Engineering Publications

Fatigue cracks are critical structural concerns for steel highway bridges, and fatigue initiation and propagation activity continues undetected between physical bridge inspections. Monitoring fatigue crack activity between physical inspections can provide far greater reliability in structural performance and can be used to prevent excessive damage and repair costs. In this paper, a thin-film strain sensor, called a soft elastomeric capacitor (SEC) sensor, is evaluated for sensing and monitoring fatigue cracks in steel bridges. The SEC is a flexible and mechanically robust strain sensor, capable of monitoring strain over large structural surfaces. By deploying multiple SECs in the form of dense ...


Quantification Of Voc Emissions From Carbonized Refuse-Derived Fuel Using Solid-Phase Microextraction And Gas Chromatography-Mass Spectrometry, Andrzej Białowiec, Monika Micuda, Antoni Szumny, Jacek Łyczko, Jacek A. Koziel Dec 2018

Quantification Of Voc Emissions From Carbonized Refuse-Derived Fuel Using Solid-Phase Microextraction And Gas Chromatography-Mass Spectrometry, Andrzej Białowiec, Monika Micuda, Antoni Szumny, Jacek Łyczko, Jacek A. Koziel

Agricultural and Biosystems Engineering Publications

In this work, for the first time, the volatile organic compound (VOC) emissions from carbonized refuse-derived fuel (CRDF) were quantified on a laboratory scale. The analyzed CRDF was generated from the torrefaction of municipal waste. Headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was used to identify 84 VOCs, including many that are toxic, e.g., derivatives of benzene or toluene. The highest emissions were measured for nonanal, octanal, and heptanal. The top 10 most emitted VOCs contributed to almost 65% of the total emissions. The VOC mixture emitted from torrefied CRDF differed from that emitted by other types ...


Analyzing Large Workers’ Compensation Claims Using Generalized Linear Models And Monte Carlo Simulation, Fatemeh Davoudi Kakhki, Steven A. Freeman, Gretchen A. Mosher Dec 2018

Analyzing Large Workers’ Compensation Claims Using Generalized Linear Models And Monte Carlo Simulation, Fatemeh Davoudi Kakhki, Steven A. Freeman, Gretchen A. Mosher

Agricultural and Biosystems Engineering Publications

Insurance practitioners rely on statistical models to predict future claims in order to provide financial protection. Proper predictive statistical modeling is more challenging when analyzing claims with lower frequency, but high costs. The paper investigated the use of predictive generalized linear models (GLMs) to address this challenge. Workers’ compensation claims with costs equal to or more than US$100,000 were analyzed in agribusiness industries in the Midwest of the USA from 2008 to 2016. Predictive GLMs were built with gamma, Weibull, and lognormal distributions using the lasso penalization method. Monte Carlo simulation models were developed to check the performance ...


Waste To Carbon: Densification Of Torrefied Refuse-Derived Fuel, Andrzej Białowiec, Monika Micuda, Jacek A. Koziel Nov 2018

Waste To Carbon: Densification Of Torrefied Refuse-Derived Fuel, Andrzej Białowiec, Monika Micuda, Jacek A. Koziel

Agricultural and Biosystems Engineering Publications

In this work, for the first time, the feasibility of obtaining carbonized refuse-derived fuel (CRDF) pelletization from municipal solid waste (MSW) was shown. Production of CRDF by torrefaction of MSW could be the future of recycling technology. The objective was to determine the applied pressure needed to produce CRDF pellets with compressive strength (CS) comparable to conventional biomass pellets. Also, the hypothesis that a binder (water glass (WG)) applied to CRDF as a coating can improve CS was tested. The pelletizing was based on the lab-scale production of CRDF pellets with pressure ranging from 8.5 MPa to 76.2 ...


Seasonal Warranty Prediction Based On Recurrent Event Data, Qianqian Shan, Yili Hong, William Q. Meeker Jr. Nov 2018

Seasonal Warranty Prediction Based On Recurrent Event Data, Qianqian Shan, Yili Hong, William Q. Meeker Jr.

Statistics Preprints

Warranty return data from repairable systems, such as vehicles, usually result in recurrent event data. The non-homogeneous Poisson process (NHPP) model is used widely to describe such data. Seasonality in the repair frequencies and other variabilities, however, complicate the modeling of recurrent event data. Not much work has been done to address the seasonality, and this paper provides a general approach for the application of NHPP models with dynamic covariates to predict seasonal warranty returns. A hierarchical clustering method is used to stratify the population into groups that are more homogeneous than the than the overall population. The stratification facilitates ...


A Data Set Of Bloodstain Patterns For Teaching And Research In Bloodstain Pattern Analysis: Gunshot Backspatters, Daniel Attinger, Yu Liu, Ricky Faflak, Yalin Rao, Bryce A. Struttman, Kris De Brabanter, Patrick M. Comiskey, Alex L. Yarin Nov 2018

A Data Set Of Bloodstain Patterns For Teaching And Research In Bloodstain Pattern Analysis: Gunshot Backspatters, Daniel Attinger, Yu Liu, Ricky Faflak, Yalin Rao, Bryce A. Struttman, Kris De Brabanter, Patrick M. Comiskey, Alex L. Yarin

Mechanical Engineering Publications

This is a data set of blood spatter patterns scanned at high resolution, generated in controlled experiments. The spatter patterns were generated with a rifle or a handgun, and different ammunitions. The resulting atomized blood droplets travelled opposite to the bullet direction, generating a gunshot backspatter on a poster board target sheet. Fresh blood with anticoagulants was used; its hematocrit and temperature were measured. Main parameters of the study were the bullet shape, size and speed, and the distance between the blood source and target sheet. Several other parameters were explored in a less systematic way. This new and original ...


Erasure Coding For Distributed Matrix Multiplication For Matrices With Bounded Entries, Li Tang, Konstantinos Konstantinidis, Aditya Ramamoorthy Nov 2018

Erasure Coding For Distributed Matrix Multiplication For Matrices With Bounded Entries, Li Tang, Konstantinos Konstantinidis, Aditya Ramamoorthy

Electrical and Computer Engineering Publications

Distributed matrix multiplication is widely used in several scientific domains. It is well recognized that computation times on distributed clusters are often dominated by the slowest workers (called stragglers). Recent work has demonstrated that straggler mitigation can be viewed as a problem of designing erasure codes. For matrices A and B, the technique essentially maps the computation of ATB into the multiplication of smaller (coded) submatrices. The stragglers are treated as erasures in this process. The computation can be completed as long as a certain number of workers (called the recovery threshold) complete their assigned tasks. We present a novel ...


Electrically-Conductive Asphalt Mastic: Temperature Dependence And Heating Efficiency, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Alireza Sassani, Kasthurirangan Gopalakrishnan, Mani Mina Nov 2018

Electrically-Conductive Asphalt Mastic: Temperature Dependence And Heating Efficiency, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Alireza Sassani, Kasthurirangan Gopalakrishnan, Mani Mina

Civil, Construction and Environmental Engineering Publications

Asphalt mastic, a pitch-matrix composite, consists of bitumen and mineral fillers (very fine aggregates), that fills the voids created by coarser aggregates in asphalt concrete. In this study, asphalt mastic was modified with carbon fiber (CF) and graphite powder (GP) to produce single-phase (containing only CF) and two-phase (containing both CF and GP) electrically-conductive asphalt mastic (ECAM) for anti-icing and deicing applications. Volume resistivities of ECAMs were measured at two different temperatures and the influence of temperature on electrical conductivity was evaluated, revealing that reduction in temperature enhances the ECAM's electrical conductivity. After analyzing the volume resistivity data for ...


Effect Of Density Ratio On Velocity Fluctuations In Dispersed Multiphase Flow From Simulations Of Finite-Size Particles, Vahid Tavanashad, Alberto Passalacqua, Rodney O. Fox, Shankar Subramaniam Nov 2018

Effect Of Density Ratio On Velocity Fluctuations In Dispersed Multiphase Flow From Simulations Of Finite-Size Particles, Vahid Tavanashad, Alberto Passalacqua, Rodney O. Fox, Shankar Subramaniam

Chemical and Biological Engineering Publications

Velocity fluctuations in the carrier phase and dispersed phase of a dispersed multiphase flow are studied using particle-resolved direct numerical simulation. The simulations correspond to a statistically homogeneous problem with an imposed mean pressure gradient and are presented for Rem=20 and a wide range of dispersed phase volume fractions (0.1≤ϕ≤0.4) and density ratios of the dispersed phase to the carrier phase (0.001≤ρp/ρf≤1000) . The velocity fluctuations in the fluid and dispersed phase at the statistically stationary state are quantified by the turbulent kinetic energy (TKE) and granular temperature, respectively. It is found ...


Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer Nov 2018

Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer

Mechanical Engineering Publications

Blood glucose monitoring is essential to avoid the unwanted consequences of glucose level fluctuations. Optical monitors are of special interest because they can be non-invasive. Among optical glucose sensors, fluorescent upconversion nanoparticles (UCNPs) have the advantage of good photostability, low toxicity, and exceptional autofluorescence suppression. However, to sense glucose, UCNPs normally need surface functionalization, and this can be easily affected by other factors in biological systems, and may also affect their ability for real-time sensing of both increasing and decreasing glucose levels. Here, we report YVO4 : Yb3+, Er3+@Nd3+core/shell UCNPs with Nd and Yb shell and GdVO4 : Yb3 ...


Performance Of Concrete Overlays In Iowa, Peter C. Taylor, Jerod Gross, Dan King, Yu-An Chen, Halil Ceylan Oct 2018

Performance Of Concrete Overlays In Iowa, Peter C. Taylor, Jerod Gross, Dan King, Yu-An Chen, Halil Ceylan

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

It has often been claimed that concrete overlays are a cost effective, low maintenance preservation tool used to extend pavement life. However, there has been relatively little data to confirm this. The State of Iowa has a long history of using concrete overlays as a means of extending the life of all types of roadways and as such provides an interesting opportunity to examine their performance over time. The work described in this paper summarizes the activities and findings of a study conducted for the Iowa Highway Research Board. Existing databases operated by the Department of Transportation and Iowa State ...


Optimization Of Time-Weighted Average Air Sampling By Solid-Phase Microextraction Fibers Using Finite Element Analysis Software, Bulat Kenessov, Jacek A. Koziel, Nassiba Baimatova, Olga P. Demyanenko, Miras Derbissalin Oct 2018

Optimization Of Time-Weighted Average Air Sampling By Solid-Phase Microextraction Fibers Using Finite Element Analysis Software, Bulat Kenessov, Jacek A. Koziel, Nassiba Baimatova, Olga P. Demyanenko, Miras Derbissalin

Agricultural and Biosystems Engineering Publications

Determination of time-weighted average (TWA) concentrations of volatile organic compounds (VOCs) in air using solid-phase microextraction (SPME) is advantageous over other sampling techniques, but is often characterized by insufficient accuracies, particularly at longer sampling times. Experimental investigation of this issue and disclosing the origin of the problem is problematic and often not practically feasible due to high uncertainties. This research is aimed at developing the model of the TWA extraction process and optimization of TWA air sampling by SPME using finite element analysis software (COMSOL Multiphysics, Burlington, MA, USA). It was established that sampling by porous SPME coatings with high ...


Lattice Instability During Solid-Solid Structural Transformations Under A General Applied Stress Tensor: Example Of Si I → Si Ii With Metallization, Nikolai A. Zarkevich, Hao Chen, Valery I. Levitas, Duane D. Johnson Oct 2018

Lattice Instability During Solid-Solid Structural Transformations Under A General Applied Stress Tensor: Example Of Si I → Si Ii With Metallization, Nikolai A. Zarkevich, Hao Chen, Valery I. Levitas, Duane D. Johnson

Aerospace Engineering Publications

The density functional theory was employed to study the stress-strain behavior and elastic instabilities during the solid-solid phase transformation (PT) when subjected to a general stress tensor, as exemplified for semiconducting Si I and metallic Si II, where metallization precedes the PT, so stressed Si I can be a metal. The hydrostatic PT occurs at 76 GPa, while under uniaxial loading it is 11 GPa (3.7 GPa mean pressure), 21 times lower. The Si I → Si II PT is described by a critical value of the phase-field’s modified transformation work, and the PT criterion has only two parameters ...


Selective Glucose Isomerization To Fructose Via Nitrogen-Doped Solid Base Catalyst Derived From Spent Coffee Grounds, Season S. Chen, Iris K.M. Yu, Dong-Wan Cho, Hocheol Song, Daniel C.W. Tsang, Jean-Philippe Tessonnier, Yong Sik Ok, Chi Sun Poon Oct 2018

Selective Glucose Isomerization To Fructose Via Nitrogen-Doped Solid Base Catalyst Derived From Spent Coffee Grounds, Season S. Chen, Iris K.M. Yu, Dong-Wan Cho, Hocheol Song, Daniel C.W. Tsang, Jean-Philippe Tessonnier, Yong Sik Ok, Chi Sun Poon

Chemical and Biological Engineering Publications

In this work, glucose isomerization to fructose was conducted via a solid base biochar catalyst derived from spent coffee grounds and melamine. The X-ray photoelectron spectroscopy (XPS) spectra identified the majority of pyridinic nitrogen on the biochar surface, which imparted the strong base character of the catalyst. Activity of the catalyst was evidenced by fast conversion of glucose (12%) and high selectivity to fructose (84%) in 20 min at a moderate temperature (120 °C) compared to recently reported immobilized tertiary amines at comparable N concentrations (10-15 mol% relative to glucose). By increasing the reaction temperature to 160 °C, fructose yield ...


Transactive Energy Design For Integrated Transmission And Distribution Systems, Hieu Trung Nguyen, Swathi Battula, Rohit Reddy Takkala, Zhaoyu Wang, Leigh Tesfatsion Oct 2018

Transactive Energy Design For Integrated Transmission And Distribution Systems, Hieu Trung Nguyen, Swathi Battula, Rohit Reddy Takkala, Zhaoyu Wang, Leigh Tesfatsion

Economics Working Papers

The increasing deployment of distributed energy resources (DERs) is disrupting every aspect of power system operations, from retail distribution to wholesale production and transmission. This paper reports on the development of an agentbased test system enabling the study of new transactive energy system (TES) designs to ensure the reliable efficient operation of integrated transmission and distribution (ITD) systems with growing DER penetration. This ITD test system is used to explore the ability of a non-profit Distribution System Operator (DSO), participating within an ITD system, to use an innovative TES design to manage the power usage of DER devices in accordance ...


Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen Oct 2018

Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen

Mechanical Engineering Publications

Flexible graphene electronics are rapidly gaining interest, but their widespread implementation has been impeded by challenges with ink preparation, ink printing, and post-print annealing processes. Laser-induced graphene (LIG) promises a facile alternative by creating flexible graphene electronics on polyimide substrates through a one-step laser writing fabrication method. Herein we demonstrate the use of LIG, created through a low-cost UV laser, for electrochemical ion selective sensing of plant-available nitrogen (i.e., both ammonium and nitrate ions: NH4+ and NO3-) in soil samples. The laser used to create the LIG was operated at distinct pulse rates (10, 20, 30, 40, and 50 ...


Spatial Structuring Of Cellulase Gene Abundance And Activity In Soil, Jinlyung Choi, Elizabeth Bach, Jaejin Lee, Jared Flater, Shane Dooley, Adina Howe, Kirsten S. Hofmockel Oct 2018

Spatial Structuring Of Cellulase Gene Abundance And Activity In Soil, Jinlyung Choi, Elizabeth Bach, Jaejin Lee, Jared Flater, Shane Dooley, Adina Howe, Kirsten S. Hofmockel

Agricultural and Biosystems Engineering Publications

Microbial mechanisms controlling cellulose degradation in soil habitats remains a critical knowledge gap in understanding and modeling terrestrial carbon-cycling. We investigated land management and soil micro-habitat influences on soil bacterial communities and distribution of cellulose-degrading enzyme genes in three bioenergy cropping systems (corn, prairie, and fertilized prairie). Within the soil, aggregates have been examined as potential micro- habitats with specific characteristics influencing resource partitioning and regulation, thus we also investigated genes associated with cellulose degradation within soil aggregate fractions from the fertilized prairie system. Soil bacterial communities and carbon-cycling gene presence varied across land management and soil microhabitats. Examination of ...


Library & Administrative Support For Civil & Environmental Engineering Scholars, Erin Thomas, Kris Stacy-Bates Oct 2018

Library & Administrative Support For Civil & Environmental Engineering Scholars, Erin Thomas, Kris Stacy-Bates

Library Reports

As university researchers’ needs for information and research support continue to change over time, it is important for university libraries to assess how well their services fit with the current research environment. Collecting perspectives from scholars in particular fields is a key step in developing and redeveloping library support for research. The Supporting Civil and Environmental Engineering Scholars project was coordinated by Ithaka S+R and sponsored by the American Society of Civil Engineers (ASCE) to explore the research and information needs of scholars in the fields of civil and environmental engineering. All phases of the research process, from idea ...


Adaptive Wavelet Neural Network For Terrestrial Laser Scanner-Based Crack Detection, Yelda Turkan, Jonathan Hong, Simon Laflamme, Nisha Puri Oct 2018

Adaptive Wavelet Neural Network For Terrestrial Laser Scanner-Based Crack Detection, Yelda Turkan, Jonathan Hong, Simon Laflamme, Nisha Puri

Civil, Construction and Environmental Engineering Publications

Objective, accurate, and fast assessment of civil infrastructure conditions is critical to timely assess safety risks. Current practices rely on visual observations and manual interpretation of reports and sketches prepared by inspectors in the field, which are labor intensive, subject to personal judgment and experience, and prone to error. Terrestrial laser scanners (TLS) are promising for automatically identifying structural condition indicators, as they are capable of providing coverage for large areas with accuracy at long ranges. Major challenges in using this technology are in storing significant amount of data and extracting appropriate features enabling condition assessment. This paper proposes a ...


Deep Learning For Plant Stress Phenotyping: Trends And Future Perspectives, Asheesh Kumar Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Arti Singh Oct 2018

Deep Learning For Plant Stress Phenotyping: Trends And Future Perspectives, Asheesh Kumar Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Arti Singh

Agronomy Publications

Deep learning (DL), a subset of machine learning approaches, has emerged as a versatile tool to assimilate large amounts of heterogeneous data and provide reliable predictions of complex and uncertain phenomena. These tools are increasingly being used by the plant science community to make sense of the large datasets now regularly collected via high-throughput phenotyping and genotyping. We review recent work where DL principles have been utilized for digital image–based plant stress phenotyping. We provide a comparative assessment of DL tools against other existing techniques, with respect to decision accuracy, data size requirement, and applicability in various scenarios. Finally ...


A Novel Multirobot System For Plant Phenotyping, Tianshuang Gao, Hamid Emadi, Homagni Saha, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh K. Singh, Sourabh Bhattacharya Sep 2018

A Novel Multirobot System For Plant Phenotyping, Tianshuang Gao, Hamid Emadi, Homagni Saha, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh K. Singh, Sourabh Bhattacharya

Mechanical Engineering Publications

Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a multi-robot system for row crop field data collection. The proposed system has been deployed in a soybean research farm at Iowa State University.


A Deep Learning-Based Approach For Fault Diagnosis Of Roller Element Bearings, Mohammakazem Sadoughi, Austin Downey, Garrett Bunge, Aditya Ranawat, Chao Hu, Simon Laflamme Sep 2018

A Deep Learning-Based Approach For Fault Diagnosis Of Roller Element Bearings, Mohammakazem Sadoughi, Austin Downey, Garrett Bunge, Aditya Ranawat, Chao Hu, Simon Laflamme

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Condition monitoring and fault detection of roller element bearings is of vital importance to ensuring safe and reliable operation of rotating machinery systems. Over the past few years, convolutional neural network (CNN) has been recognized as a useful tool for fault detection of roller element bearings. Unlike the traditional fault diagnosis approaches, CNN does not require manually extracting the fault-related features from the raw sensor data and most CNN-based fault diagnosis approaches feed the raw or shallowly pre-processed data as the training/testing inputs to a CNN model, thereby avoiding the need for manual feature extraction. As such, these approaches ...


Inverting Thermal Degradation (Itd) Of Paper Using Chemi- And Physi-Sorbed Modifiers For Templated Material Synthesis, Paul R. Gregory, Andrew Martin, Boyce S. Chang, Stephanie Oyola-Reynoso, Jean-Francis Bloch, Martin M. Thuo Sep 2018

Inverting Thermal Degradation (Itd) Of Paper Using Chemi- And Physi-Sorbed Modifiers For Templated Material Synthesis, Paul R. Gregory, Andrew Martin, Boyce S. Chang, Stephanie Oyola-Reynoso, Jean-Francis Bloch, Martin M. Thuo

Materials Science and Engineering Publications

Fibrous cellulosic materials have been used as templates for material synthesis or organization via thermal degradation of the cellulose. Most of these methods, however, fail to exploit fiber organization, in part due to loss of structure with processing. Herein, we demonstrate that chemi- and physi-sorbed modifiers of cellulose alters the thermal degradation mechanism allowing for controlled deposition of oxide and carbon (incomplete combustion) along the original paper fiber network. We demonstrate that the degradation of the cellulose fibers depends on the amount of physisorbed material due, in part, to effect on the propagation of the ignition event. From the distribution ...


Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo Sep 2018

Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo

Mechanical Engineering Publications

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting ...


Disorder-Driven Transition From S(+/-) To S(+ +) Superconducting Order Parameter In Proton Irradiated Ba(Fe1-Xrhx)(2)As-2 Single Crystals, G. Ghigo, D. Torsello, G. A. Ummarino, L. Gozzelino, Makariy A. Tanatar, Ruslan Prozorov, Paul C. Canfield Sep 2018

Disorder-Driven Transition From S(+/-) To S(+ +) Superconducting Order Parameter In Proton Irradiated Ba(Fe1-Xrhx)(2)As-2 Single Crystals, G. Ghigo, D. Torsello, G. A. Ummarino, L. Gozzelino, Makariy A. Tanatar, Ruslan Prozorov, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

Microwave measurements of the London penetration depth and critical temperature T c were used to show evidence of a disordered-driven transition from s ± to s + + order parameter symmetry in optimally doped Ba ( Fe 1 − x Rh x ) 2 As 2 single crystals, where disorder was induced by means of 3.5 MeV proton irradiation. Signatures of such a transition, as theoretically predicted [V. D. Efremov et al., Phys. Rev. B 84, 180512(R) (2011)], are found as a drop in the low-temperature values of the London penetration depth and a virtually disorder-independent superconducting T c . We show how these experimental ...


Human Factors And Ergonomics In Diversity, Inclusion And Social Justice Research, Rupa Valdez, Enid Montague, Mattie N. Milner, Michael C. Dorneich, Rod Roscoe Sep 2018

Human Factors And Ergonomics In Diversity, Inclusion And Social Justice Research, Rupa Valdez, Enid Montague, Mattie N. Milner, Michael C. Dorneich, Rod Roscoe

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

The Human Factors and Ergonomics Society Diversity Committee is entering its second year and continuing to explore ways to increase the diversity of the society. Following last year’s panel on “Challenges and Opportunities for Involvement,” we, and others, recognized that human factors and ergonomics (HFE) professionals are equipped and able to advance diversity, inclusion and social justice issues. This panel will bring together researchers to discuss experiences addressing these issues to highlight existing work, spark excitement about conducting new work and share advice. This panel will discuss and share lessons learned in a range of projects, including an HFE ...


The Wearer, The Device, And Its Use: Advances In Understanding The Social Acceptability Of Wearables, Norene Kelly, Stephen B. Gilbert Sep 2018

The Wearer, The Device, And Its Use: Advances In Understanding The Social Acceptability Of Wearables, Norene Kelly, Stephen B. Gilbert

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

The WEAR Scale was used to collect data on the social acceptability of three wearable devices from 1,387 participants from the US Midwest and Silicon Valley. The most notable result was that a head-worn “medical device” was rated as more socially acceptable (d=0.78) than the same device described as a “brain fitness tool,” which was the opposite of what was hypothesized. Also, as hypothesized, Silicon Valley participants found the wearables more socially acceptable than Midwestern U.S. participants. The Scale and these results enable industry to better predict the human factors affecting social acceptability of wearables throughout ...