Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 20 of 20

Full-Text Articles in Engineering

Integrating Multimedia Models To Assess Nitrogen Losses From The Mississippi River Basin To The Gulf Of Mexico, Ruoyu Wang Nov 2018

Integrating Multimedia Models To Assess Nitrogen Losses From The Mississippi River Basin To The Gulf Of Mexico, Ruoyu Wang

Ruoyu Wang

This study describes and implements an integrated, multimedia, process-based system-level approach to estimating nitrogen (N) fate and transport in large river basins. The modeling system includes the following components: (1) Community Multiscale Air Quality (CMAQ), (2) Weather Research and Forecasting Model (WRF), (3) Environmental Policy Integrated Climate (EPIC), and (4) Soil and Water Assessment Tool (SWAT). The previously developed Fertilizer Emission Scenario Tool for CMAQ (FEST-C), an advanced user interface, integrated EPIC with the WRF model and CMAQ. The FEST-C system, driven by process-based WRF weather simulations, includes atmospheric N additions to agricultural cropland and agricultural cropland contributions to ammonia emissions. This study focuses …


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

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

Erin Thomas

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 generation …


Input Uncertainty On Watershed Modeling: Evaluation Of Precipitation And Air Temperature Data By Latent Variables Using Swat, Ruoyu Wang Oct 2018

Input Uncertainty On Watershed Modeling: Evaluation Of Precipitation And Air Temperature Data By Latent Variables Using Swat, Ruoyu Wang

Ruoyu Wang

Latent variables (i.e., normally distributed random noise) provide valuable information regarding model input uncertainty. Watershed processes have been explored with sophisticated simulation models in the past few decades and researchers have found that incorporating the uncertainty attributed to forcing inputs, model parameters, and measured data, can help improve simulation results, however, not in all cases. Latent variable use requires careful consideration to determine if results are better or worse. In this study, latent variables were implemented to both precipitation and air temperature data to investigate the influence on model predictions and associated predictive uncertainty by using the Soil and Water …


The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


Response Spectrum Estimation Using Support Vector Machines, Jale Tezcan, Qiang Cheng, Lincoln Hill Sep 2018

Response Spectrum Estimation Using Support Vector Machines, Jale Tezcan, Qiang Cheng, Lincoln Hill

Qiang CHENG

This study investigates the applicability and efficiency of support vector machines for the problem of estimating the earthquake response spectra from the Fourier amplitude spectra of the ground motion acceleration. Two methods are commonly used for this purpose: time domain simulations, and the random vibration theory. The use of time domain simulations offers high accuracy at high computational cost, while the use random vibration theory, although not computationally intensive, requires knowledge of the statistical distribution of the response amplitudes. This study treats the task of estimating response spectra from the Fourier spectra as a nonlinear regression problem, and constructs a …


Multi-Objective Bayesian Optimization Of Super Hydrophobic Coatings On Asphalt Concrete Surfaces, Ali Nahvi, Ali Arabzadeh, Alireza Sassani, Mohammadkazem Sadoughi, Halil Ceylan Aug 2018

Multi-Objective Bayesian Optimization Of Super Hydrophobic Coatings On Asphalt Concrete Surfaces, Ali Nahvi, Ali Arabzadeh, Alireza Sassani, Mohammadkazem Sadoughi, Halil Ceylan

Ali Nahvi

Conventional snow removal strategies add direct and indirect expenses to the economy through profit lost due to passenger delays costs, pavement durability issues, contaminating the water runoff, and so on. The use of superhydrophobic (super-water-repellent) coating methods is an alternative to conventional snow and ice removal practices for alleviating snow removal operations issues. As an integrated experimental and analytical study, this work focused on optimizing superhydrophobicity and skid resistance of hydrophobic coatings on asphalt concrete surfaces. A layer-by-layer (LBL) method was utilized for spray depositing polytetrafluoroethylene (PTFE) on an asphalt concrete at different spray times and variable dosages of PTFE. …


Ultrasonic Techniques For Air Void Size Distribution And Property Evaluation In Both Early-Age And Hardened Concrete Samples, Shuaicheng Guo, Qingli Dai, Xiao Sun, Ye Sun, Zhen Liu Aug 2018

Ultrasonic Techniques For Air Void Size Distribution And Property Evaluation In Both Early-Age And Hardened Concrete Samples, Shuaicheng Guo, Qingli Dai, Xiao Sun, Ye Sun, Zhen Liu

Zhen Liu

Entrained air voids can improve the freeze-thaw durability of concrete, and also affect its mechanical and transport properties. Therefore, it is important to measure the air void structure and understand its influence on concrete performance for quality control. This paper aims to measure air void structure evolution at both early-age and hardened stages with the ultrasonic technique, and evaluates its influence on concrete properties. Three samples with different air entrainment agent content were specially prepared. The air void structure was determined with optimized inverse analysis by achieving the minimum error between experimental and theoretical attenuation. The early-age sample measurement showed …


Lowest Matric Potential In Quartz: Metadynamics Evidence, Chao Zhang, Yi Dong, Zhen Liu Aug 2018

Lowest Matric Potential In Quartz: Metadynamics Evidence, Chao Zhang, Yi Dong, Zhen Liu

Zhen Liu

The lowest matric potential is an important soil property characterizing the strength of retaining water molecules and a key parameter in defining a complete soil water retention curve. However, the exact value of the lowest matric potential is still unclear and cannot be measured due to the limitation of current experimental technology. In this study, a general theoretical framework based on metadynamics was proposed to determine the lowest matric potential in quartz minerals. The matric potential was derived from partial volume free energy and can be further calculated by the difference between the adsorption free energy and self‐hydration free energy. …


Atomistic‐Scale Investigation Of Effective Stress Principle Of Saturated Porous Materials By Molecular Dynamics, Chao Zhang, Zhen Liu, Peng Deng Aug 2018

Atomistic‐Scale Investigation Of Effective Stress Principle Of Saturated Porous Materials By Molecular Dynamics, Chao Zhang, Zhen Liu, Peng Deng

Zhen Liu

The effective stress principle is one of the most fundamental concepts in the mechanics of porous materials. Several mathematical expressions have been proposed for this fundamental principle, leading to unsettled debates on the validity and applicability of the principle and its mathematical descriptions. Recent developments in atomistic modeling techniques make it possible to understand multiphase systems at the atomistic scale. In this paper, molecular dynamics simulation is explored as a tool to investigate the stress formulation in porous materials. A molecular dynamics framework, including molecular models of phases, interatomic potentials, initial configuration, and simulation procedure, is presented. Numerical simulations based …


Predication Of The Sources Of Particulate Polycyclic Aromatic Hydrocarbons In China With Distinctive Characteristics Based On Multivariate Analysis, Ruoyu Wang May 2018

Predication Of The Sources Of Particulate Polycyclic Aromatic Hydrocarbons In China With Distinctive Characteristics Based On Multivariate Analysis, Ruoyu Wang

Ruoyu Wang

Particulate polycyclic aromatic hydrocarbons (PAHs) have the characteristics of high carcinogenicitydegradation resistance, and long-distance transport. It is necessary to determine the critical sources that contribute to PAHs in atmospheric particulatematter (PM), soils, and sediments. In the present study, particulate PAHs were collected from Chinese cooking, biomass combustion, waste incineration, coal combustion, and petroleum combustion in different regions of the Chinese mainland. Through linear regression analysis, the relationships have been investigated between different measurement units, including the mass of particulate PAHs per mass of particle matter, mass of particulate PAHs per volume of …


New Mixture Additives For Sustainable Bituminous Pavements, Gabriel Nsengiyumva, Kommidi Santosh, Yong-Rak Kim, Helan Xu, Yiqi Yang Phd May 2018

New Mixture Additives For Sustainable Bituminous Pavements, Gabriel Nsengiyumva, Kommidi Santosh, Yong-Rak Kim, Helan Xu, Yiqi Yang Phd

Gabriel Nsengiyumva

In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives
was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and
binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC
mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA …


Evaluation Of Testing Methods For Tracking Cipp Liners’ Life-Cycle Performance, Shaurav Alam, John Matthews Apr 2018

Evaluation Of Testing Methods For Tracking Cipp Liners’ Life-Cycle Performance, Shaurav Alam, John Matthews

John C. Matthews

No abstract provided.


Resilience Is A Property Of A System And A Network, Igor Linkov, Benjamin D. Trump, Jeffrey Keisler Feb 2018

Resilience Is A Property Of A System And A Network, Igor Linkov, Benjamin D. Trump, Jeffrey Keisler

Jeffrey Keisler

This e-Letter, available at http://science.sciencemag.org/content/359/6379/986/tab-e-letters, responds to the Science special issue on resilience. We argue that it in order to move from understanding resilience toward improving it, it is useful to incorporate not just the systems perspective, but also that of network science.


Dense-Graded Aggregate Base Gradation Influencing Rutting Model Predictions, Issam I.A. Qamhia, Liang Chern Chow, Debakanta Mishra, Erol Tutumluer Feb 2018

Dense-Graded Aggregate Base Gradation Influencing Rutting Model Predictions, Issam I.A. Qamhia, Liang Chern Chow, Debakanta Mishra, Erol Tutumluer

Debakanta Mishra

This paper presents findings from an ongoing research study at the University of Illinois focused on developing and calibrating an improved permanent deformation model for unbound aggregate materials through laboratory testing and characterization. The project scope included testing sixteen aggregate materials, commonly used in the state of North Carolina for pavement base courses, in the laboratory through monotonic and repeated load triaxial testing. This paper primarily focuses on quantifying effects of aggregate gradation on permanent deformation behavior. To accomplish this, four materials were tested at both: (1) “source gradations,” i.e. original gradations from quarry, and (2) an “engineered gradation,” i.e., …


Internet Enabled Remote Driving Of A Combat Hybrid Electric Power System For Duty Cycle Measurement, Jarrett Goodell, Marc Compere, Wilford Smith, Mark Brudnak, Mike Pozolo, Et Al. Feb 2018

Internet Enabled Remote Driving Of A Combat Hybrid Electric Power System For Duty Cycle Measurement, Jarrett Goodell, Marc Compere, Wilford Smith, Mark Brudnak, Mike Pozolo, Et Al.

Marc Compere

This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware, both of which were used to measure the duty cycle of a combat vehicle in a virtual simulation environment. The project discussed is a greatly expanded follow-on to the experiment published in [1,7]. This paper is written in the context of [1,7] and therefore highlights the enhancements. The most prominent of these enhancements is the integration (in real-time) of the Power & Energy System Integration Lab (P&E SIL) with a motion base simulator by means of a “long haul” connection over the Internet (a geographical distance of …


The Effect Of Water And Gypsum Content On Strätlingite Formation In Calcium Sulfoaluminate-Belite Cement Pastes, Yeonung Jeong, Craig W. Hargis, Sung-Chul Chun, Juhyuk Moon Jan 2018

The Effect Of Water And Gypsum Content On Strätlingite Formation In Calcium Sulfoaluminate-Belite Cement Pastes, Yeonung Jeong, Craig W. Hargis, Sung-Chul Chun, Juhyuk Moon

Craig Hargis

The main objective of this study was to investigate the phase and strength development of calcium
sulfoaluminate-belite (CSAB) cement pastes with different amounts of gypsum and water.
Thermodynamic modeling and a series of experiments including X-ray diffraction (XRD), thermogravimetric analysis, isothermal calorimetry, and compressive strength tests were performed. Decreasing the mixing water increased the strength of CSAB pastes, but decreased the degree of hydration. Interpretation of the early age XRD results and thermodynamic modeling suggested the formation of a meta-stable phase from the hydration of belite, possibly C-(A)-S-H, which transformed into strätlingite at later ages only in the samples with …


Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru Jan 2018

Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru

Deogratias Eustace

The knowledge of drivers on who has the right-of-way between the one on mainline lanes of a freeway and the one entering the freeway through on-ramp junction lane was evaluated. In addition, drivers’ opinions on how to make the on-ramp junctions safer were collected. A survey instrument with 21 items requesting drivers’ information in regard with demographics, freeway driving experience, knowledge of right-of-way and merging practices was used for data collection. The results show that crashes are relatively rare events and for some reasons, most of them never happen but result into near misses, which can not be reported and …


Engineering Standards In Highway Design Litigation, Michael Lewyn Dec 2017

Engineering Standards In Highway Design Litigation, Michael Lewyn

Michael E Lewyn

Highway engineers sometimes believe that if they redesign streets to improve pedestrian safety (for example, by introducing traffic calming techniques) they might be successfully sued for negligent design by motorists. This chapter suggests that in such situations, governments are likely to be protected by discretionary function immunity. In addition, the chapter discusses a variety of technical issues.


Engineering Standards In Highway Design Litigation, Michael Lewyn Dec 2017

Engineering Standards In Highway Design Litigation, Michael Lewyn

Michael E Lewyn

Chapter in "Engineering Standards for Forensic Application." (coauthored) Focuses on soveriegn immunity for highway designers.