Engineering Commons^™

Approximation Of The Time Rate Of Consolidation For Hydraulically Placed Fine Coal Refuse Using A Variable Coefficient Of Consolidation Method, Cyrus Jedari, Eric Drumm, Angelica Palomino

Faculty Publications and Other Works -- Civil & Environmental Engineering

Terzaghi’s consolidation theory assumes strain in soil due to applied overburden pressure is small, and permeability and thus the coefficient of consolidation (C_v) remain constant during consolidation. Although valid for soft soil consolidation, the C_v for hydraulically placed slurry materials with low solids content may change significantly during the consolidation process as the material transitions from a slurry to a solid. In this study, a spatial and temporal variable C_v was used to predict the time rate of consolidation of fine coal refuse placed in an impoundment as a slurry. The results suggest the variable …

Role Of Multiagency Response And On-Scene Times In Large-Scale Traffic Incidents, Xiaobing Li, Behram Wali

Faculty Publications and Other Works -- Civil & Environmental Engineering

Traffic incidents, often known as nonrecurring events, impose enormous economic and social costs. Compared with short-duration incidents, large-scale incidents can substantially disrupt traffic flow by blocking lanes on highways for long periods. A careful examination of large-scale traffic incidents and associated factors can assist with actionable largescale incident management strategies. For such an analysis, a unique and comprehensive 5-year incident database on East Tennessee roadways was assembled to conduct an in-depth investigation of large-scale incidents, especially focusing on operational responses, that is, response and on-scene times by various agencies. Incidents longer than 120 min and blocking at least one lane …

Extraction And Recovery Of 2-Butoxyethanol From Aqueous Phases Containing High Saline Concentration, Katherine E. Manz, Kimberly E. Carter

Faculty Publications and Other Works -- Civil & Environmental Engineering

Ethylene glycol monobutyl ether (EGBE), also known as 2-butoxyethanol (2-BE), has been identified as a contaminant in hydraulic fracturing fluids. In order to determine the presence of 2-BE in hydraulic fracturing chemical additives, a reliable method for recovering 2-BE from aqueous phases by liquid-liquid extraction combined with gas chromatography/mass spectrometry (GC/MS) was established. The liquid-liquid extraction method was applied to samples matrices containing various amounts of salt. Using methylene chloride for liquid-liquid extraction in a sample to solvent ratio of 1:3, ≥99% 2-BE recovery may be achieved with less than 5% standard error. The limit of detection was determined to …

Model Development Of Dust Emission And Heterogeneous Chemistry Within The Community Multiscale Air Quality Modeling System And Its Application Over East Asia, Xinyi Dong, Joshua S. Fu, Kan Huang, Daniel Tong, Guoshun Zhuang

Faculty Publications and Other Works -- Civil & Environmental Engineering

The Community Multiscale Air Quality (CMAQ) model has been further developed in terms of simulating natural wind-blown dust in this study, with a series of modifications aimed at improving the model's capability to predict the emission, transport, and chemical reactions of dust. The default parameterization of initial threshold friction velocity constants are revised to correct the double counting of the impact of soil moisture in CMAQ by the reanalysis of field experiment data; source-dependent speciation profiles for dust emission are derived based on local measurements for the Gobi and Taklamakan deserts in East Asia; and dust heterogeneous chemistry is also …

Colwellia Psychrerythraea Strains From Distant Deep Sea Basins Show Adaptation To Local Conditions, Stephen M. Techtmann, Kathleen S. Fitzgerald, Savannah C. Stelling, Dominique C. Joyner, Sagar M. Uttukar, Austin P. Harris, Noor K. Alshibli, Steven D. Brown, Terry C. Hazen

Faculty Publications and Other Works -- Civil & Environmental Engineering

Many studies have shown that microbes, which share nearly identical 16S rRNA genes, can have highly divergent genomes. Microbes from distinct parts of the ocean also exhibit biogeographic patterning. Here we seek to better understand how certain microbes from the same species have adapted for growth under local conditions. The phenotypic and genomic heterogeneity of three strains of Colwellia psychrerythraeawas investigated in order to understand adaptions to local environments. Colwellia are psychrophilic heterotrophic marine bacteria ubiquitous in cold marine ecosystems. We have recently isolated two Colwellia strains: ND2E from the Eastern Mediterranean and GAB14E from the Great Australian Bight. …

Discontinuous Element Insertion Algorithm, Timothy James Truster

Faculty Publications and Other Works -- Civil & Environmental Engineering

An algorithm is presented for inserting zero-thickness interface elements, termed herein as “couplers”, into continuous finite element meshes in two and three dimensions. Insertion is governed solely by the mesh topology and is specified according to regions or subdomains within the overall analysis domain, a geometrically intuitive means to designate the coupler locations. The algorithm is self-contained and requires only nodal coordinates and element connectivity as input. A wide class of volume elements and interface couplers are treated within the framework. Since the algorithm is topologically-based, interfaces of arbitrary complexity are naturally accommodated. Separate treatment is given to inserting couplers …

Health Hazards Of China’S Lead-Acid Battery Industry: A Review Of Its Market Drivers, Production Processes, And Health Impacts, Tsering Jan Van Der Kuijp, Lei Huang, Christopher R. Cherry

Faculty Publications and Other Works -- Civil & Environmental Engineering

Despite China’s leaded gasoline phase out in 2000, the continued high rates of lead poisoning found in children’s blood lead levels reflect the need for identifying and controlling other sources of lead pollution. From 2001 to 2007, 24% of children in China studied (N = 94,778) were lead poisoned with levels exceeding 100 μg/L. These levels stand well above the global average of 16%. These trends reveal that China still faces significant public health challenges, with millions of children currently at risk of lead poisoning. The unprecedented growth of China’s lead-acid battery industry from the electric bike, automotive, and photovoltaic …

Structure And Regulation Of The Cellulose Degradome In Clostridium Cellulolyticum, Chenggang Xu, Ranran Huang, Lin Teng, Dongmei Wang, Christopher L. Hemme, Ilya Borovok, Qiang He, Ralph Lamed, Edward A, Bayer, Jizhong Zhou, Jian Xu

Faculty Publications and Other Works -- Civil & Environmental Engineering

Background

Many bacteria efficiently degrade lignocellulose yet the underpinning genome-wide metabolic and regulatory networks remain elusive. Here we revealed the “cellulose degradome” for the model mesophilic cellulolytic bacterium Clostridium cellulolyticum ATCC 35319, via an integrated analysis of its complete genome, its transcriptomes under glucose, xylose, cellobiose, cellulose, xylan or corn stover and its extracellular proteomes under glucose, cellobiose or cellulose.

Results

Proteins for core metabolic functions, environment sensing, gene regulation and polysaccharide metabolism were enriched in the cellulose degradome. Analysis of differentially expressed genes revealed a “core” set of 48 CAZymes required for degrading cellulose-containing substrates as well as an …

Projected Changes Of Extreme Weather Events In The Eastern United States Based On A High Resolution Climate Modeling System, Y Gao, J S. Fu, J B. Drake, Y Liu, J-F Lamarque

Faculty Publications and Other Works -- Civil & Environmental Engineering

This study is the first evaluation of dynamical downscaling using the Weather Research and Forecasting (WRF) Model on a 4 km × 4 km high resolution scale in the eastern US driven by the new Community Earth System Model version 1.0 (CESM v1.0). First we examined the global and regional climate model results, and corrected an inconsistency in skin temperature during the downscaling process by modifying the land/sea mask. In comparison with observations, WRF shows statistically significant improvement over CESM in reproducing extreme weather events, with improvement for heat wave frequency estimation as high as 98%. The fossil fuel intensive …

Dehalogenimonas Spp. Can Reductively Dehalogenate High Concentrations Of 1,2-Dichloroethane, 1,2-Dichloropropane, And 1,1,2-Trichloroethane, Andrew D. Maness, Kimberly S. Bowman, Jun Yan, Fred A. Rainey, William M. Moe

Faculty Publications and Other Works -- Civil & Environmental Engineering

The contaminant concentrations over which type strains of the species Dehalogenimonas alkenigignens and Dehalogenimonas lykanthroporepellens were able to reductively dechlorinate 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA) were evaluated. Although initially isolated from an environment with much lower halogenated solvent concentrations, D. alkenigignens IP3-3^T was found to reductively dehalogenate chlorinated alkanes at concentrations comparable to D. lykanthroporepellens BL-DC-9^T. Both species dechlorinated 1,2-DCA, 1,2-DCP, and 1,1,2-TCA present at initial concentrations at least as high as 8.7, 4.0, and 3.5 mM, respectively. The ability of Dehalogenimonas spp. to carry out anaerobic reductive dechlorination even in the presence of …

Impact Of Anthropogenic Emission On Air Quality Over A Megacity – Revealed From An Intensive Atmospheric Campaign During The Chinese Spring Festival, K Huang, G Zhuang, Y Lin, Q Wang, Joshua S. Fu, R Zhang, J Li, C Deng, Q Fu

Faculty Publications and Other Works -- Civil & Environmental Engineering

The Chinese Spring Festival is one of the most important traditional festivals in China. The peak transport in the Spring Festival season (spring travel rush) provides a unique opportunity for investigating the impact of human activity on air quality in the Chinese megacities. Emission sources are varied and fluctuate greatly before, during and after the Festival. Increased vehicular emissions during the "spring travel rush" before the 2009 Festival resulted in high level pollutants of NO_x (270 μg m⁻³), CO (2572 μg m⁻³), black carbon (BC) (8.5 μg m⁻³) and extremely low single scattering …

Typical Types And Formation Mechanisms Of Haze In An Eastern Asia Megacity, Shanghai, K Huang, G Zhuang, Joshua S. Fu, Q Wang, T Liu, R Zhang, Y Jiang, C Deng, Q Fu, N C. Hsu, B Cao

Faculty Publications and Other Works -- Civil & Environmental Engineering

An intensive aerosol and gases campaign was performed at Shanghai in the Yangtze River Delta region over Eastern China from late March to early June 2009. This study provided a complementary picture of typical haze types and the formation mechanisms in megacities over China by using a synergy of ground-based monitoring, satellite and lidar observations. During the whole study period, several extreme low visibility periods were observed with distinct characteristics, and three typical haze types were identified, i.e. secondary inorganic pollution, dust, and biomass burning. Sulfate, nitrate and ammonium accounted for a major part of PM_2.5 mass during the …

Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, Joshua Fu, S. Wu, L. J. Mickley

Faculty Publications and Other Works -- Civil & Environmental Engineering

Simulations of present and future average regional ozone and PM_2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared …

Air Quality And Emissions In The Yangtze River Delta, China, L. Li, C. H. Chen, Joshua Fu, C. Huang, D. G. Streets, H. Y. Huang, G. F. Zhang, Y. J. Wang, C. J. Jang, H. L. Wang, Y. R. Chen, J. M. Fu

Faculty Publications and Other Works -- Civil & Environmental Engineering

Regional trans-boundary air pollution has become an important issue in the field of air pollution modeling. This paper presents the results of the implementation of the MM5-CMAQ modeling system in the Yangtze River Delta (YRD) for the months of January and July of 2004. The meteorological parameters are obtained by using the MM5 model. A new regional emission inventory with spatial and temporal allocations based on local statistical data has been developed to provide input emissions data to the MM5-CMAQ modeling system. The pollutant concentrations obtained from the MM5-CMAQ modeling system have been compared with observational data from the national …

Characteristics, Sources And Formation Of Aerosol Oxalate In An Eastern Asia Megacity And Its Implication To Haze Pollution, Y Jiang, G Zhuang, Q Wang, T Liu, K Huang, Joshua S. Fu, J Li, Y Lin, R Zhang, C Deng

Faculty Publications and Other Works -- Civil & Environmental Engineering

A total of 238 samples of PM_2.5 and TSP were analyzed to study the characteristics, sources, and formation pathways of aerosol oxalate in Shanghai in four seasons of 2007. The concentrations of oxalate were 0.07–0.41 μg m⁻³ in PM_2.5 and 0.10–0.48 μg m⁻³ in TSP, respectively. Oxalate displayed a seasonal variation of autumn>summer>winter>spring in both PM_2.5 and TSP and was dominantly present in PM_2.5 in all samples. Correlation between oxalate and K⁺ and high ratio of oxalate/K⁺ suggested that biomass burning was a secondary source of aerosol oxalate in …

A Regional Chemical Transport Modeling To Identify The Influences Of Biomass Burning During 2006 Base-Asia, Joshua Fu, N C. Hsu, Y Gao, K Huang, C Li, N H. Lin, S C. Tsay

Faculty Publications and Other Works -- Civil & Environmental Engineering

To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA's 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27–28 March and 13–14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to CO, O₃ and PM_2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 μg/m³, respectively. The perturbations with and without biomass burning of the above three species were in the …

A Regional Chemical Transport Modeling To Identify The Influences Of Biomass Burning During 2006 Base-Asia, Joshua Fu, N. C. Hsu, Y. Gao, K. Huang, C. Li, N.-H. Lin, S.-C. Tsay

Faculty Publications and Other Works -- Civil & Environmental Engineering

To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA's 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27–28 March and 13–14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to CO, O₃ and PM_2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 μg/m³, respectively. The perturbations with and without biomass burning of the above three species were in the …

A Novel Downscaling Technique For The Linkage Of Global And Regional Air Quality Modeling, Y. F. Lam, Joshua Fu

Faculty Publications and Other Works -- Civil & Environmental Engineering

Recently, downscaling global atmospheric model outputs (GCTM) for the USEPA Community Multiscale Air Quality (CMAQ) Initial (IC) and Boundary Conditions (BC) have become practical because of the rapid growth of computational technologies that allow global simulations to be completed within a reasonable time. The traditional method of generating IC/BC by profile data has lost its advocates due to the weakness of the limited horizontal and vertical variations found on the gridded boundary layers. Theoretically, high quality GCTM IC/BC should yield a better result in CMAQ. Unfortunately, several researchers have found that the outputs from GCTM IC/BC are not necessarily better …

Investigation Of Truck-Involved Angle Crashes Based On Ges And Fars Crash Databases, Yan Xeudong, Essam Radwan, Kranthi Kiran Mannila, Stephen Richards

Faculty Publications and Other Works -- Civil & Environmental Engineering

Truck-car angle collisions have a higher crash frequency than other truck-involved collision types and tend to increase injury severity. This paper investigates both general and fatal truck-involved angle collisions using two national crash databases (2000-2004), General estimates system (GES) and Fatality Analysis Reporting system (FARS). In this study, two-vehicle angle collisions were classified into three groups based on fault roles of truck or car drivers in the accidents, including Truck-Car, Car-Truck, and Car-Car crashes. The occurrence conditions of the three angle crash types were compared to each other to identify the potential risk factors such as driver characteristics, road environments, …

A Novel Downscaling Technique For The Linkage Of Global And Regional Air Quality Modeling, Y. F. Lam, Joshua Fu

Faculty Publications and Other Works -- Civil & Environmental Engineering

Recently, downscaling global atmospheric model outputs (GCTM) for the USEPA Community Multiscale Air Quality (CMAQ) Initial (IC) and Boundary Conditions (BC) have become practical because of the rapid growth of computational technologies that allow global simulations to be completed within a reasonable time. The traditional method of generating IC/BC by profile data has lost its advocates due to the weakness of the limited horizontal and vertical variations found on the gridded boundary layers. Theoretically, high quality GCTM IC/BC should yield a better result in CMAQ. Unfortunately, several researchers have found that the outputs from GCTM IC/BC are not necessarily better …