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Full-Text Articles in Engineering

Assessment Of Groundwater Resources In Siwa Oasis, Western Desert, Egypt, Noha H. Moghazy, Jagath J. Kaluarachchi Dec 2019

Assessment Of Groundwater Resources In Siwa Oasis, Western Desert, Egypt, Noha H. Moghazy, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

One of the major challenges facing Egypt is limited water resources associated with rapid increase in population. In 1960s, Egyptian government started to use groundwater from the Nubian Sandstone Aquifer System (NSAS) in the Western Desert to expand agricultural sector. Siwa Oasis is the focus of this study to assess the efficiency of groundwater use and corresponding impacts from 1980 to 2012. Results show that from 1980 to 1998, withdrawal from poorly designed wells increased rapidly causing an increase in excess water about 336%. The increase of excess water with the usage of poor drainage produced lakes. Remote Sensing showed …


Incorporation Of Unmanned Aerial Vehicle (Uav) Point Cloud Products Into Remote Sensing Evapotranspiration Models, Mahyar Aboutalebi, Alfonso F. Torres-Rua, Mac Mckee, William P. Kustas, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Lynn Mckee, Joseph Alfieri, Lawrence E. Hipps, Calvin Coopmans, Nick Dokoozlian Dec 2019

Incorporation Of Unmanned Aerial Vehicle (Uav) Point Cloud Products Into Remote Sensing Evapotranspiration Models, Mahyar Aboutalebi, Alfonso F. Torres-Rua, Mac Mckee, William P. Kustas, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Lynn Mckee, Joseph Alfieri, Lawrence E. Hipps, Calvin Coopmans, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

In recent years, the deployment of satellites and unmanned aerial vehicles (UAVs) has led to production of enormous amounts of data and to novel data processing and analysis techniques for monitoring crop conditions. One overlooked data source amid these efforts, however, is incorporation of 3D information derived from multi-spectral imagery and photogrammetry algorithms into crop monitoring algorithms. Few studies and algorithms have taken advantage of 3D UAV information in monitoring and assessment of plant conditions. In this study, different aspects of UAV point cloud information for enhancing remote sensing evapotranspiration (ET) models, particularly the Two-Source Energy Balance Model (TSEB), over …


Wintertime Spatial Distribution Of Ammonia And Its Emission Sources In The Great Salt Lake Region, Alexander Moravek, Jennifer G. Murphy, Amy Hrdina, John C. Lin, Christopher Pennell, Alessandro Franchin, Ann M. Middlebrook, Dorothy L. Fibiger, Caroline C. Womack, Erin E. Mcduffie, Randy S. Martin, Kori D. Moore, Munkhbayar Baasandorj, Steven S. Brown Dec 2019

Wintertime Spatial Distribution Of Ammonia And Its Emission Sources In The Great Salt Lake Region, Alexander Moravek, Jennifer G. Murphy, Amy Hrdina, John C. Lin, Christopher Pennell, Alessandro Franchin, Ann M. Middlebrook, Dorothy L. Fibiger, Caroline C. Womack, Erin E. Mcduffie, Randy S. Martin, Kori D. Moore, Munkhbayar Baasandorj, Steven S. Brown

Civil and Environmental Engineering Faculty Publications

Ammonium-containing aerosols are a major component of wintertime air pollution in many densely populated regions around the world. Especially in mountain basins, the formation of persistent cold-air pools (PCAPs) can enhance particulate matter with diameters less than 2.5 µm (PM2.5) to levels above air quality standards. Under these conditions, PM2.5 in the Great Salt Lake region of northern Utah has been shown to be primarily composed of ammonium nitrate; however, its formation processes and sources of its precursors are not fully understood. Hence, it is key to understanding the emission sources of its gas phase precursor, ammonia …


Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung Dec 2019

Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

With the continuous development of nanomaterials, how to improve the conversion efficiency of DSSCs has been the focus of scholars. Nano-TiO2 material is a wide bandgap semiconductor with a bandgap of 3.2eV. It exhibits good performance in dye adsorption, charge separation, electron transport, etc., and has good chemical stability and strong acid and alkali resistance. Therefore, it was always the material of choice for the preparation of photoanodes. In this paper, different thicknesses of TiO2 NRs barrier layers were prepared on FTO substrates by solvothermal method and two-step spin coating method, and their electrochemical and photoelectric properties were tested by …


An Application Of Bayesian Multilevel Model To Evaluate Variations In Stochastic And Dynamic Transition Of Traffic Conditions, Emmanuel Kidando, Ren Moses, Thobias Sando, Eren Erman Ozguven Dec 2019

An Application Of Bayesian Multilevel Model To Evaluate Variations In Stochastic And Dynamic Transition Of Traffic Conditions, Emmanuel Kidando, Ren Moses, Thobias Sando, Eren Erman Ozguven

Civil and Environmental Engineering Faculty Publications

© 2019, The Author(s). This study seeks to investigate the variations associated with lane lateral locations and days of the week in the stochastic and dynamic transition of traffic regimes (DTTR). In the proposed analysis, hierarchical regression models fitted using Bayesian frameworks were used to calibrate the transition probabilities that describe the DTTR. Datasets of two sites on a freeway facility located in Jacksonville, Florida, were selected for the analysis. The traffic speed thresholds to define traffic regimes were estimated using the Gaussian mixture model (GMM). The GMM revealed that two and three regimes were adequate mixture components for estimating …


Restoration Of Defaced Serial Numbers Using Lock-In Infrared Thermography (Part I), Ikwulono Unobe, Lisa Lau, John Kalivas, Rene Rodriguez, Andrew D. Sorensen Nov 2019

Restoration Of Defaced Serial Numbers Using Lock-In Infrared Thermography (Part I), Ikwulono Unobe, Lisa Lau, John Kalivas, Rene Rodriguez, Andrew D. Sorensen

Civil and Environmental Engineering Faculty Publications

Infrared thermal imaging is an evolving approach useful in non-destructive evaluation of materials for industrial and research purposes. This study investigates the use of this method in combination with multivariate data analysis as an alternative to chemical etching; a destructive method currently used to recover defaced serial numbers stamped in metal. This process involves several unique aspects, each of which works to overcome some pertinent challenges associated with the recovery of defaced serial numbers. Infrared thermal imaging of metal surfaces provides thermal images sensitive to local differences in thermal conductivity of regions of plastic strain existing below a stamped number. …


Restoration Of Defaced Serial Numbers Using Lock-In Infrared Thermography (Part Ii), Ikwulono Unobe, Lisa Lau, John Kalivas, Rene Rodriguez, Andrew D. Sorensen Nov 2019

Restoration Of Defaced Serial Numbers Using Lock-In Infrared Thermography (Part Ii), Ikwulono Unobe, Lisa Lau, John Kalivas, Rene Rodriguez, Andrew D. Sorensen

Civil and Environmental Engineering Faculty Publications

This paper details continuing work on the development of a substantive non-destructive method to recover defaced serial numbers stamped or laser engraved into metallic objects based on lock-in infrared thermography. This method relies on the existence of a local zone of plastic strain created from stamping pressures in mechanically stamped pieces and a heat-affected zone in laser engraved samples, both extending to depths below the visible characters. The grain structure within these zones is dislocated due to the external forces applied. These deformed areas are exposed to the surface when the serial numbers are defaced. Infrared thermography utilises the change …


Advances In Remote Sensing To Understand Extreme Hydrological Events, Dongkyun Kim, Minha Choi, Jongho Kim, Ungtae Kim Nov 2019

Advances In Remote Sensing To Understand Extreme Hydrological Events, Dongkyun Kim, Minha Choi, Jongho Kim, Ungtae Kim

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Incorporating Travel Time Reliability In Predicting The Likelihood Of Severe Crashes On Arterial Highways Using Non-Parametric Random-Effect Regression, Emmanuel Kidando, Ren Moses, Eren Erman Ozguven, Thobias Sando Oct 2019

Incorporating Travel Time Reliability In Predicting The Likelihood Of Severe Crashes On Arterial Highways Using Non-Parametric Random-Effect Regression, Emmanuel Kidando, Ren Moses, Eren Erman Ozguven, Thobias Sando

Civil and Environmental Engineering Faculty Publications

© 2019 The Authors Travel time reliability (TTR) modeling has gain attention among researchers' due to its ability to represent road user satisfaction as well as providing a predictability of a trip travel time. Despite this significant effort, its impact on the severity of a crash is not well explored. This study analyzes the effect of TTR and other variables on the probability of the crash severity occurring on arterial roads. To address the unobserved heterogeneity problem, two random-effect regressions were applied; the Dirichlet random-effect (DRE) and the traditional random-effect (TRE) logistic regression. The difference between the two models is …


Wetland Arid Vegetation – Studies Of Vegetated Stormwater Management System Performance In Northern Utah – Field & Lab Experiences, Ryan Dupont, Margie Rycewicz-Borecki, Trixie Rife Oct 2019

Wetland Arid Vegetation – Studies Of Vegetated Stormwater Management System Performance In Northern Utah – Field & Lab Experiences, Ryan Dupont, Margie Rycewicz-Borecki, Trixie Rife

Civil and Environmental Engineering Faculty Publications

Motivation for the Work We’ve Done – The Why

Summary of the Work We’ve Done - The What & The How

Findings - The How Well

Conclusions & Recommendations – The So What


An Open-Source Data Manager For Network Models, Stephen Knox, James Tomlinson, Julien J. Harou, Philipp Meier, David E. Rosenberg, Jay R. Lund, David E. Rheinheimer Sep 2019

An Open-Source Data Manager For Network Models, Stephen Knox, James Tomlinson, Julien J. Harou, Philipp Meier, David E. Rosenberg, Jay R. Lund, David E. Rheinheimer

Civil and Environmental Engineering Faculty Publications

Developing simulation and optimisation models for resource networks like water or energy systems increasingly involves integrating multiple data sources and software. Connecting multiple models and managing data accessed by different groups of analysts is a software challenge. Many resource systems are represented in computer models as networks of nodes and links, driven by a range of objectives and rules. We present a data storage platform, written in Python, which exploits the commonality of network representations to store data for multiple model types within a single deployment. This open-source platform provides a common source of data to multiple models using consistent …


Analysis Of The Effects Of Dam Release Properties And Ambient Groundwater Flow On Surface Water‐Groundwater Exchange Over A 100‐Km‐Long Reach, Stephen B. Ferencz, M. Bayani Cardenas, Bethany T. Neilson Sep 2019

Analysis Of The Effects Of Dam Release Properties And Ambient Groundwater Flow On Surface Water‐Groundwater Exchange Over A 100‐Km‐Long Reach, Stephen B. Ferencz, M. Bayani Cardenas, Bethany T. Neilson

Civil and Environmental Engineering Faculty Publications

Hydroelectric dams often create highly dynamic downstream flows that promote surface water‐groundwater (SW‐GW) interactions including bank storage, the temporary storage of river water in the riverbank. Previous research on SW‐GW exchanges in dammed rivers has primarily been at single study sites, which has limited the understanding of how these exchanges evolve as dam releases travel downstream. This study evaluates how dam releases affect SW‐GW exchange continuously over a 100‐km distance. This is accomplished by longitudinally routing water releases through a synthetic river and modeling bed and bank fluid and solute exchange across transverse transects spaced along the reach. Peak and …


Agricultural Drought Assessment Based On Multiple Soil Moisture Products, Jongjin Baik, Muhammad Zohaib, Ungtae Kim, Muhammad Aadil, Minha Choi Aug 2019

Agricultural Drought Assessment Based On Multiple Soil Moisture Products, Jongjin Baik, Muhammad Zohaib, Ungtae Kim, Muhammad Aadil, Minha Choi

Civil and Environmental Engineering Faculty Publications

In this study, we evaluated three soil moisture (SM) products (Advanced Microwave Scanning Radiometer-2 [AMSR2], Advanced SCATterometer [ASCAT], and European Reanalysis Interim [ERA-interim]) across Australia in four climate zones by comparing against the Australian Water Resources Assessment-Landscape (AWRA-L) SM products from July 2012 to June 2017. The ASCAT SM indicated better performance than other SM products over Australia. To evaluate the applicability and reliability for monitoring agricultural drought, an agricultural drought index, the Soil Water Deficit Index, was estimated from three SM products and compared with three commonly-used drought indices (atmospheric water deficit [AWD], Evaporative Stress Index, and Reconnaissance …


Quantifying Thermal Refugia Connectivity By Combining Temperature Modeling, Distributed Temperature Sensing, And Thermal Infrared Imaging, Jessica R. Dzara, Bethany T. Neilson, Sarah E. Null Jul 2019

Quantifying Thermal Refugia Connectivity By Combining Temperature Modeling, Distributed Temperature Sensing, And Thermal Infrared Imaging, Jessica R. Dzara, Bethany T. Neilson, Sarah E. Null

Civil and Environmental Engineering Faculty Publications

Watershed-scale stream temperature models are often one-dimensional because they require fewer data and are more computationally efficient than two- or three-dimensional models. However, one-dimensional models assume completely mixed reaches and ignore small-scale spatial temperature variability, which may create temperature barriers or refugia for cold-water aquatic species. Fine spatial- and temporal-resolution stream temperature monitoring provides information to identify river features with increased thermal variability. We used distributed temperature sensing (DTS) to observe small-scale stream temperature variability, measured as a temperature range through space and time, within two 400 m reaches in summer 2015 in Nevada's East Walker and main stem Walker …


Active Layer Groundwater Flow: The Interrelated Effects Of Stratigraphy, Thaw, And Topography, Michael T. O'Connor, M. Bayani Cardenas, Bethany T. Neilson, Kindra D. Nicholaides, George W. Kling Jul 2019

Active Layer Groundwater Flow: The Interrelated Effects Of Stratigraphy, Thaw, And Topography, Michael T. O'Connor, M. Bayani Cardenas, Bethany T. Neilson, Kindra D. Nicholaides, George W. Kling

Civil and Environmental Engineering Faculty Publications

The external drivers and internal controls of groundwater flow in the thawed “active layer” above permafrost are poorly constrained because they are dynamic and spatially variable. Understanding these controls is critical because groundwater can supply solutes such as dissolved organic matter to surface water bodies. We calculated steady‐state three‐dimensional suprapermafrost groundwater flow through the active layer using measurements of aquifer geometry, saturated thickness, and hydraulic properties collected from two major landscape types over time within a first‐order Arctic watershed. The depth position and thickness of the saturated zone is the dominant control of groundwater flow variability between sites and during …


Twenty-Three Unsolved Problems In Hydrology (Uph) – A Community Perspective, Günter Blöschl, Marc F.P. Bierkens, Antonio Chambel, Christophe Cudennec, Georgia Destouni, Aldo Fiori, James W. Kirchner, Jeffrey J. Mcdonnell, Hubert H.G. Savenije, Murugesu Sivapalan, Christine Stumpp, Elena Toth, Elena Volpi, Gemma Carr, David G. Tarboton, Et. Al Jul 2019

Twenty-Three Unsolved Problems In Hydrology (Uph) – A Community Perspective, Günter Blöschl, Marc F.P. Bierkens, Antonio Chambel, Christophe Cudennec, Georgia Destouni, Aldo Fiori, James W. Kirchner, Jeffrey J. Mcdonnell, Hubert H.G. Savenije, Murugesu Sivapalan, Christine Stumpp, Elena Toth, Elena Volpi, Gemma Carr, David G. Tarboton, Et. Al

Civil and Environmental Engineering Faculty Publications

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused …


Thermal Bowing Testing Of Precast Concrete Sandwich Wall Panels, Fray Pozo-Lora, Marc Maguire May 2019

Thermal Bowing Testing Of Precast Concrete Sandwich Wall Panels, Fray Pozo-Lora, Marc Maguire

Civil and Environmental Engineering Faculty Publications

Thermal bowing is out-of-plane wall deflection, which is a common issue on sandwich panel walls caused by a temperature differential between a building interior temperature and the environmental conditions.

This report aims to better understand thermal load response of concrete sandwich wall panels. Full-scale testing was performed to verify the assumptions regarding thermal gradient, temperature variation at the cross-section level and thermal conductivity of the connectors.

It was found out that carbon fiber reinforced polymer nor glass fiber reinforced polymer connectors transfer a significate amount of heat from one wythe to the other, hence, the temperature in one wythe remained …


Analytical Models For 3-D Diffusion Of Ions From Salt-Contaminated Aggregates, Robert J. Thomas, Andrew D. Sorensen, Marc Maguire Apr 2019

Analytical Models For 3-D Diffusion Of Ions From Salt-Contaminated Aggregates, Robert J. Thomas, Andrew D. Sorensen, Marc Maguire

Civil and Environmental Engineering Faculty Publications

This article presents an analytical investigation of the mobility of salts from contaminated aggregates in concrete. Salt-contaminated aggregates may have varied effects on the mechanical properties and durability of concrete. These depend primarily on the mobility of salts within the concrete matrix. Existing diffusion-based models for the mobility of salts in concrete focus on their intrusion from external sources (e.g., chloride penetration from deicing salts and brines). Such problems are well described by the closed-form solution of Fick’s law for diffusion in one dimension from a continuous source. Salt-contaminated aggregates represent a case of diffusion from a finite internal source …


Low-Cost, Open-Source, And Low-Power: But What To Do With The Data?, Jeffery S. Horsburgh, Juan Caraballo, Maurier Ramírez, Anthony K. Aufdenkampe, David B. Arscott, Sara Geleskie Damiano Apr 2019

Low-Cost, Open-Source, And Low-Power: But What To Do With The Data?, Jeffery S. Horsburgh, Juan Caraballo, Maurier Ramírez, Anthony K. Aufdenkampe, David B. Arscott, Sara Geleskie Damiano

Civil and Environmental Engineering Faculty Publications

There are now many ongoing efforts to develop low-cost, open-source, low-power sensors and datalogging solutions for environmental monitoring applications. Many of these have advanced to the point that high quality scientific measurements can be made using relatively inexpensive and increasingly off-the-shelf components. With the development of these innovative systems, however, comes the ability to generate large volumes of high-frequency monitoring data and the challenge of how to log, transmit, store, and share the resulting data. This paper describes a new web application that was designed to enable citizen scientists to stream sensor data from a network of Arduino-based dataloggers to …


A New Method For Microsimulation Model Calibration: A Case Study Of I-710, Hossein Nasr Esfahani, Ziqi Song Mar 2019

A New Method For Microsimulation Model Calibration: A Case Study Of I-710, Hossein Nasr Esfahani, Ziqi Song

Civil and Environmental Engineering Faculty Publications

As a part of the feasibility analysis of electric truck roadways for some of the major corridors near Los Angles, California, this paper aims to introduce and investigate a new method for microsimulation model calibration. The model of I-710 southbound was developed in VISSIM software and calibrated through two sets of data: O-D demand from planning models and field data which was consist of traffic flow and speed. Due to the lack of proper count data for on-ramps/off-ramps, the O-D demand was estimated via path flow estimator. After determining the calibration parameters, in an attempt to avoid unnecessary VISSIM’s time-consuming …


Exploring Boarding Strategies For High-Speed Railway, Tie-Qiao Tang, Yi-Xiao Shao, Liang Chen, Hai-Jun Huang, Ziqi Song Mar 2019

Exploring Boarding Strategies For High-Speed Railway, Tie-Qiao Tang, Yi-Xiao Shao, Liang Chen, Hai-Jun Huang, Ziqi Song

Civil and Environmental Engineering Faculty Publications

In light of the increasing demand for passenger transportation on high-speed railway (HSR), the pedestrian flow at HSR stations has become quite crowded in many countries, which has attracted researchers to study the HSR boarding behavior. In this paper, we propose three boarding strategies based on the features of the boarding behavior at an origin HSR station; we then use a cellular automaton (CA) model to study the impacts of boarding strategies on each passenger’s motion during the boarding process at HSR station. The simulation results indicate that some of the three strategies can optimize some passengers’ boarding time and …


Assessing Data Availability And Research Reproducibility In Hydrology And Water Resources, James H. Stagge, David E. Rosenberg, Adel M. Abdallah, Hadia Akbar, Nour A. Atallah, Ryan James Feb 2019

Assessing Data Availability And Research Reproducibility In Hydrology And Water Resources, James H. Stagge, David E. Rosenberg, Adel M. Abdallah, Hadia Akbar, Nour A. Atallah, Ryan James

Civil and Environmental Engineering Faculty Publications

There is broad interest to improve the reproducibility of published research. We developed a survey tool to assess the availability of digital research artifacts published alongside peer-reviewed journal articles (e.g. data, models, code, directions for use) and reproducibility of article results. We used the tool to assess 360 of the 1,989 articles published by six hydrology and water resources journals in 2017. Like studies from other fields, we reproduced results for only a small fraction of articles (1.6% of tested articles) using their available artifacts. We estimated, with 95% confidence, that results might be reproduced for only 0.6% to 6.8% …


A Data Model To Manage Data For Water Resources Systems Modeling, Adel M. Abdallah, David E. Rosenberg Feb 2019

A Data Model To Manage Data For Water Resources Systems Modeling, Adel M. Abdallah, David E. Rosenberg

Civil and Environmental Engineering Faculty Publications

Current practices to identify, organize, analyze, and serve data to water resources systems models are typically model and dataset-specific. Data are stored in different formats, described with different vocabularies, and require manual, model-specific, and time-intensive manipulations to find, organize, compare, and then serve to models. This paper presents the Water Management Data Model (WaMDaM) implemented in a relational database. WaMDaM uses contextual metadata, controlled vocabularies, and supporting software tools to organize and store water management data from multiple sources and models and allow users to more easily interact with its database. Five use cases use thirteen datasets and models focused …


Water Pollution In Old Towns Affecting The Environment And Ecological Restoration, Zou Hang, Muhammad Aqeel Ashraf, Yung Tse Hung Jan 2019

Water Pollution In Old Towns Affecting The Environment And Ecological Restoration, Zou Hang, Muhammad Aqeel Ashraf, Yung Tse Hung

Civil and Environmental Engineering Faculty Publications

© 2019 Technoscience Publications. All rights reserved. In order to solve the problem that the traditional activated sludge method is not effective in recovering the ecological process of water pollution in urban areas, the membrane bioreactor-based sewage treatment process was studied experimentally. Two flat-plate ultrafiltration membranes were used to form the ultrafilter tank in the experimental device sampled, and the processes of nitrate cycle and sludge cycle were adopted. Ozonation and granular activated carbon filtration were adopted to treat the micropollutants. After repeated experiments in 17 experimental cycles, the obtained experimental data were analysed, and it was found that under …


Impact Of Sea Surface Temperature And Surface Air Temperature On Maximizing Typhoon Rainfall: Focusing On Typhoon Maemi In Korea, Jeonghyeon Choi, Jeonghoon Lee, Sangdan Kim Jan 2019

Impact Of Sea Surface Temperature And Surface Air Temperature On Maximizing Typhoon Rainfall: Focusing On Typhoon Maemi In Korea, Jeonghyeon Choi, Jeonghoon Lee, Sangdan Kim

Civil and Environmental Engineering Faculty Publications

In this study, the effects of surface air temperature (SAT) and sea surface temperature (SST) changes on typhoon rainfall maximization are analysed. Based on the numerically reproduced Typhoon Maemi, this study tried to maximize the typhoon-induced rainfall by increasing the amount of saturated water vapour in the atmosphere and the amount of water vapour entering the typhoon. Using the Weather Research and Forecasting (WRF) model, which is one of the regional climate models (RCMs), the rainfall simulated by WRF while increasing the SAT and SST to various sizes at initial conditions and boundary conditions of the model was analysed. As …


Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung Jan 2019

Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

In order to study the intensity of chemical weathering during the formation of sedimentary strata in the site profile, the evolution of climatic environment in the region where the site profile is located was revealed. The rubidium (Rb) and strontium (Sr) values in the rubidium (Rb) and strontium (Sr) were tested and analysed. The Rb/Sr ratio has become an ideal alternative indicator in the study of regional environmental evolution. The Rb value in the strata section of Zhongba site is low, and the average value (calculated based on 202 sample values) is only 80 g/g. The Sr value was higher, …


Stochastic Cost-Optimization And Risk Assessment Of In Situ Chemical Oxidation For Dense Non-Aqueous Phase Liquid (Dnapl) Source Remediation, Ungtae Kim, Jack C. Parker, Robert C. Borden Jan 2019

Stochastic Cost-Optimization And Risk Assessment Of In Situ Chemical Oxidation For Dense Non-Aqueous Phase Liquid (Dnapl) Source Remediation, Ungtae Kim, Jack C. Parker, Robert C. Borden

Civil and Environmental Engineering Faculty Publications

This study involved development of a computer program to determine optimal design variables for in situ chemical oxidation (ISCO) of dense nonaqueous phase liquid (DNAPL) sites to meet site-wide remediation objectives with minimum life-cycle remediation cost while taking uncertainty in site characterization data and model predictions into consideration. A physically-based ISCO performance model computes field-scale DNAPL dissolution, instantaneous reaction of oxidant with contaminant and with readily oxidizable natural oxidant demand (NOD), second-order kinetic reactions for slowly oxidizable NOD, and time to reach ISCO termination criteria. Remediation cost is computed by coupling the performance model with a cost module. ISCO termination …


A Route Navigation Algorithm For Pedestrian Simulation Based On Grid Potential Field, Minghua Li, Yun Wei, Yan Xu Jan 2019

A Route Navigation Algorithm For Pedestrian Simulation Based On Grid Potential Field, Minghua Li, Yun Wei, Yan Xu

Civil and Environmental Engineering Faculty Publications

Pedestrian simulation modeling has become an important means to study the dynamic characters of dense populations. In the continuous pedestrian simulation model for complex simulation scenario with obstacles, the pedestrian path planning algorithm is an indispensable component, which is used for the calculation of pedestrian macro path and microscopic movement desired direction. However, there is less efficiency and poor robustness in the existing pedestrian path planning algorithm. To address this issue, we propose a new pedestrian path planning algorithm to solve these problems in this article. In our algorithm, we have two steps to determine pedestrian movement path, that is, …


Future Climate And Land Use Change Impacts On River Flows In The Tapajós Basin In The Brazilian Amazon, Fabio Farinosi, Mauricio E. Arias, Eunjee Lee, Marcos Longo, Fabio F. Pereira, Angela Livino, Paul R. Moorcroft, John Briscoe Jan 2019

Future Climate And Land Use Change Impacts On River Flows In The Tapajós Basin In The Brazilian Amazon, Fabio Farinosi, Mauricio E. Arias, Eunjee Lee, Marcos Longo, Fabio F. Pereira, Angela Livino, Paul R. Moorcroft, John Briscoe

Civil and Environmental Engineering Faculty Publications

Land conversion and changing climate are expected to significantly alter tropical forest hydrology. We used a land surface model integrated with a river routing scheme to analyze the hydrological alterations expected in the Tapajós River basin, a large portion of the Brazilian Amazon, caused by two environmental drivers: climate and land use. The model was forced with two future climate scenarios (years 2026–2045) from the Earth System Model HadGem2-ES with moderate (+4.5 W/m2 radiative forcing value in the year 2100 with respect to preindustrial levels) and severe (+8.5 W/m2) representative atmospheric carbon dioxide pathways (Representative Concentration Pathways). …


Analysis Of Truck-Related Crashes Of Freeways In China, Ting Xu, Rui-Sen Jiang, Lei Zhao, Long Qi, Yu Zhang Jan 2019

Analysis Of Truck-Related Crashes Of Freeways In China, Ting Xu, Rui-Sen Jiang, Lei Zhao, Long Qi, Yu Zhang

Civil and Environmental Engineering Faculty Publications

Truck-related crashes result in tremendous lives and property loss and become a serious safety issue in China. The goal of this article is to identify the influential factors for severity of truck-related crashes using data from Jingjintang freeways in China and to design an ordered probit model to explore their relationship. Records including crashes, traffic flow attributes, and geometric design features ranging from 2009 to 2012 were collected from Jingjintang freeway. Crashes are divided into three severity levels: slight injury, injury, and fatal injury. The injury crashes is ranking the first place occupying 64.37%. Truck-related crashes are likely to occur …