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Articles 3481 - 3510 of 6127

Full-Text Articles in Civil and Environmental Engineering

Analyses, Calibration And Validation Of Evapotranspirationmodels To Predict Grass-Reference Evapotranspiration In Thesenegal River Delta, Koffi Djaman, Hossein Tabari, Alpha B. Balde, Lamine Diop, Koichi Futakuchi, Suat Irmak Jan 2016

Analyses, Calibration And Validation Of Evapotranspirationmodels To Predict Grass-Reference Evapotranspiration In Thesenegal River Delta, Koffi Djaman, Hossein Tabari, Alpha B. Balde, Lamine Diop, Koichi Futakuchi, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Study region: Grass-reference evapotranspiration estimation by the Penman-Monteithmethod (PM-ETo) requires a number of climate variables which are not always availableat all weather stations. Different alternative ETo equations have been developed and theirutilization for various local climate conditions requires analyses of their accuracy as com-pared to the standardized Penman-Monteith method. There is a significant lack of data andinformation on this topic in the Senegal River Delta (SRD). Study focus: The objective of this study was to evaluate, calibrate and validate six EToequations ((Trabert, Mahringer, Penman1948, Albrecht, Valiantzas1 and Valiantzas2) forthe SRD. Although all six equations showed good agreement with the PM-ETo …


A Multi-Sensor System For High Throughput Field Phenotyping In Soybean And Wheat Breeding, Geng Bai, Yufeng Ge, Waseem Hussain, P. Stephen Baenziger, George L. Graef Jan 2016

A Multi-Sensor System For High Throughput Field Phenotyping In Soybean And Wheat Breeding, Geng Bai, Yufeng Ge, Waseem Hussain, P. Stephen Baenziger, George L. Graef

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Collecting plant phenotypic data with sufficient resolution (in both space and time) and accuracy represents a long standing challenge in plant science research, and has been a major limiting factor for the effective use of genomic data for crop improvement. This is particularly true in plant breeding where collecting large-scale field-based plant phenotypes can be very labor intensive and costly. In this paper we reported a multi-sensor system for high throughput phenotyping in plant breeding. The system comprised five sensor modules (ultrasonic distance sensors, thermal infrared radiometers, NDVI sensors, portable spectrometers, and RGB web cameras) to measure crop canopy traits …


A Multi-Scale Comparison Of Modeled And Observed Seasonal Methane Emissions In Northern Wetlands, Xiyan Xu, William J. Riley, Charles D. Koven, Dave P. Billesbach, Rachel Y.-W. Chang, Roisin Commane, Eugenie S. Euskirchen, Sean Hartery, Yoshinobu Harazono, Hiroki Iwata, Kyle C. Mcdonald, Charles E. Miller, Walter C. Oechel, Benjamin Poulter, Naama Raz-Yaseef, Colm Sweeny, Margaret Torn, Steven C. Wofsy, Zhen Zhang, Donatella Zona Jan 2016

A Multi-Scale Comparison Of Modeled And Observed Seasonal Methane Emissions In Northern Wetlands, Xiyan Xu, William J. Riley, Charles D. Koven, Dave P. Billesbach, Rachel Y.-W. Chang, Roisin Commane, Eugenie S. Euskirchen, Sean Hartery, Yoshinobu Harazono, Hiroki Iwata, Kyle C. Mcdonald, Charles E. Miller, Walter C. Oechel, Benjamin Poulter, Naama Raz-Yaseef, Colm Sweeny, Margaret Torn, Steven C. Wofsy, Zhen Zhang, Donatella Zona

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wetlands are the largest global natural methane (CH4) source, and emissions between 50 and 70° N latitude contribute 10–30% to this source. Predictive capability of land models for northern wetland CH4 emissions is still low due to limited site measurements, strong spatial and temporal variability in emissions, and complex hydrological and biogeochemical dynamics. To explore this issue, we compare wetland CH4 emission predictions from the Community Land Model 4.5 (CLM4.5-BGC) with siteto regional-scale observations. A comparison of the CH4 fluxes with eddy flux data highlighted needed changes to the model’s estimate of aerenchyma area, which …


Direct And Indirect Effects Of Climatic Variations On The Interannual Variability In Net Ecosystem Exchange Across Terrestrial Ecosystems, Junjiong Shao, Xuhui Zhou, Yiqi Luo, Bo Li, Mika Aurela, David Billesbach, Peter D. Blanken, Rosvel Bracho, Jiquan Chen, Marc Fischer, Yuling Fu, Lianhong Gu, Shijie Han, Yongtao He, Thomas Kolb, Yingnian Li, Zoltan Nagy, Shuli Niu, Walter C. Oechel, Krisztina Pinter, Peili Shi, Andrew Suyker, Margaret Torn, Andrej Varlagin, Huimin Wang, Junhua Yan, Guirui Yu, Junhui Zhang Jan 2016

Direct And Indirect Effects Of Climatic Variations On The Interannual Variability In Net Ecosystem Exchange Across Terrestrial Ecosystems, Junjiong Shao, Xuhui Zhou, Yiqi Luo, Bo Li, Mika Aurela, David Billesbach, Peter D. Blanken, Rosvel Bracho, Jiquan Chen, Marc Fischer, Yuling Fu, Lianhong Gu, Shijie Han, Yongtao He, Thomas Kolb, Yingnian Li, Zoltan Nagy, Shuli Niu, Walter C. Oechel, Krisztina Pinter, Peili Shi, Andrew Suyker, Margaret Torn, Andrej Varlagin, Huimin Wang, Junhua Yan, Guirui Yu, Junhui Zhang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climatic variables not only directly affect the interannual variability (IAV) in net ecosystem exchange of CO2 (NEE) but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C) dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor …


Cellulase Immobilization On Superparamagnetic Nanoparticles For Reuse In Cellulosic Biomass Conversion, Qing Song, Yu Mao, Mark Wilkins, Fernando Segato, Rolf Prade Jan 2016

Cellulase Immobilization On Superparamagnetic Nanoparticles For Reuse In Cellulosic Biomass Conversion, Qing Song, Yu Mao, Mark Wilkins, Fernando Segato, Rolf Prade

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Current cellulosic biomass hydrolysis is based on the one-time use of cellulases. Cellulases immobilized on magnetic nanocarriers offer the advantages of magnetic separation and repeated use for continuous hydrolysis. Most immobilization methods focus on only one type of cellulase. Here, we report co-immobilization of two types of cellulases, β-glucosidase A (BglA) and cellobiohydrolase D (CelD), on sub-20 nm superparamagnetic nanoparticles. The nanoparticles demonstrated 100% immobilization efficiency for both BglA and CelD. The total enzyme activities of immobilized BglA and CelD were up to 67.1% and 41.5% of that of the free cellulases, respectively. The immobilized BglA and CelD each retained …


Switchgrass Storage Effects On The Recovery Of Carbohydrates After Liquid Hot Water Pretreatment And Enzymatic Hydrolysis, Noaa Frederick, Mengxing Li, Danielle Julie Carrier, Michael D. Buser, Mark R. Wilkins Jan 2016

Switchgrass Storage Effects On The Recovery Of Carbohydrates After Liquid Hot Water Pretreatment And Enzymatic Hydrolysis, Noaa Frederick, Mengxing Li, Danielle Julie Carrier, Michael D. Buser, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW) and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass …


Ecosystem Evapotranspiration: Challenges In Measurements, Estimates, And Modeling, D.M. Amatya, Sibel Irmak, P. Gowda, G. Sun, J.E. Nettles, K.R. Douglas-Mankin Jan 2016

Ecosystem Evapotranspiration: Challenges In Measurements, Estimates, And Modeling, D.M. Amatya, Sibel Irmak, P. Gowda, G. Sun, J.E. Nettles, K.R. Douglas-Mankin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Evapotranspiration (ET) processes at the leaf to landscape scales in multiple land uses have important con- trols and feedbacks for local, regional, and global climate and water resource systems. Innovative methods, tools, and technologies for improved understanding and quantification of ET and crop water use are critical for adapting more effective management strategies to cope with increasing demand for freshwater resources under global climate change. This article introduces an ASABE Special Collection of 12 articles on ET monitoring and modeling research for multiple land uses and scales. The collection focuses on recent advances in four critical topical areas: (1) reference …


Critical Factors Affecting The Integration Of Biomass Gasification And Syngas Fermentation Technology, Karthikeyan D. Ramachandriya, Dimple K. Kundiyana, Ashokkumar M. Sharma, Ajay Kumar, Hasan K. Atiyeh, Raymond L. Huhnke, Mark R. Wilkins Jan 2016

Critical Factors Affecting The Integration Of Biomass Gasification And Syngas Fermentation Technology, Karthikeyan D. Ramachandriya, Dimple K. Kundiyana, Ashokkumar M. Sharma, Ajay Kumar, Hasan K. Atiyeh, Raymond L. Huhnke, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gasification-fermentation is a thermochemical-biological platform for the production of fuels and chemicals. Biomass is gasified at high temperatures to make syngas, a gas composed of CO, CO2, H2, N2 and other minor components. Syngas is then fed to anaerobic microorganisms that convert CO, CO2 and H2 to alcohols by fermentation. This platform offers numerous advantages such as flexibility of feedstock and syngas composition and lower operating temperature and pressure compared to other catalytic syngas conversion processes. In comparison to hydrolysis-fermentation, gasification-fermentation has a major advantage of utilizing all organic components of biomass, including lignin, to yield higher fuel production. Furthermore, …


Incorporation Of Globally Available Datasets Into The Roving Cosmic-Ray Neutron Probe Method For Estimating Field-Scale Soil Water Content, William A. Avery, Catherine Finkenbiner, Trenton E. Franz, Tiejun Wang, Anthony L. Nguy-Robertson, Andrew E. Suyker, Timothy J. Arkebauer, Francisco Munoz-Arriola Jan 2016

Incorporation Of Globally Available Datasets Into The Roving Cosmic-Ray Neutron Probe Method For Estimating Field-Scale Soil Water Content, William A. Avery, Catherine Finkenbiner, Trenton E. Franz, Tiejun Wang, Anthony L. Nguy-Robertson, Andrew E. Suyker, Timothy J. Arkebauer, Francisco Munoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The need for accurate, real-time, reliable, and multi-scale soil water content (SWC) monitoring is critical for a multitude of scientific disciplines trying to understand and predict the Earth’s terrestrial energy, water, and nutrient cycles. One promising technique to help meet this demand is fixed and roving cosmic-ray neutron probes (CRNPs). However, the relationship between observed low-energy neutrons and SWC is affected by local soil and vegetation calibration parameters. This effect may be accounted for by a calibration equation based on local soil type and the amount of vegetation. However, determining the calibration parameters for this equation is labor- and time-intensive, …


New Frontiers In Chemical Energy And Environmental Engineering, Srinath Suranani, Sandeep Kumar, Sundergopal Sridhar Jan 2016

New Frontiers In Chemical Energy And Environmental Engineering, Srinath Suranani, Sandeep Kumar, Sundergopal Sridhar

Civil & Environmental Engineering Faculty Publications

(First paragraph) Energy is one of the major building blocks of modern society. Industries are attributed to be the main source of environmental pollution. The problems associated with the energy and environment have now become the subject of international debate. Engineers play vital role in devising environmental pollution mitigating techniques and developing sustainable energy technologies.


Low Impact Development Analysis And Comparative Assessment Of Wet Detention Ponds With Floating Treatment Wetlands, Nicholas Hartshorn Jan 2016

Low Impact Development Analysis And Comparative Assessment Of Wet Detention Ponds With Floating Treatment Wetlands, Nicholas Hartshorn

Electronic Theses and Dissertations

The aim of this thesis is to examine, develop, and assess innovative best management practices (BMPs) in stormwater management for pollutant reduction, flood control, and environmental sustainability. Previous research has clearly shown that urban stormwater runoff quickly transports pathogens, metals, sediment, and chemical pollutants to receiving waterbodies, resulting in the degradation of receiving waters and disruption of ecological networks. In response to this growing concern, regulatory agencies, such as the Environmental Protection Agency (EPA) and the Florida Department of Environmental Protection (FDEP), have set forth regulations aimed at protecting and restoring waterbodies. These regulations include numeric nutrient criteria (NNC) and …


Do Characteristics Of Walkable Environments Support Bicycling? Toward A Definition Of Bicycle-Supported Development, Christopher D. Muhs, Kelly Clifton Jan 2016

Do Characteristics Of Walkable Environments Support Bicycling? Toward A Definition Of Bicycle-Supported Development, Christopher D. Muhs, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Does walkability equate with bikeability? Through a comprehensive review of studies of the built environment and bicycling, including mode choice, route choice, safety, and urban design literature, this paper addresses this question. Previous work has raised the issue that the two modes are functionally different, despite them often being combined into a nonmotorized category, and has highlighted research challenges. Existing studies of bikeability have largely focused on infrastructure. This paper contributes to the literature on bicycling and the built environment by providing a thorough review of past research with a focus on the relationships between land use, urban form, and …


Field Study Of Electrochemical Disinfection Of Municipal Wastewater, Luis De Grau Vidal Dec 2015

Field Study Of Electrochemical Disinfection Of Municipal Wastewater, Luis De Grau Vidal

LSU New Orleans Theses and Dissertations

Research on electrochemical disinfection of municipal wastewater has been conducted at the University of New Orleans using a continuous flow electrochemical reactor connected to a direct current (DC) power supply changing its polarity and varying the electrode distance. Bacterial inactivation and chlorine production were the main parameters that were recorded.

After months of research, it was determined that the electrochemical disinfection reactor is efficient and has a great potential for the future. There is no need to use chlorine and it has low operation costs.

The following design recommendations for an electrochemical disinfection unit were given:

  • A detention time of …


Multi-Criteria Evaluation Of Cmip5 Gcms For Climate Change Impact Analysis, Ali Ahmadalipour, Arun Rana, Hamid Moradkhani, Ashish Sharma Dec 2015

Multi-Criteria Evaluation Of Cmip5 Gcms For Climate Change Impact Analysis, Ali Ahmadalipour, Arun Rana, Hamid Moradkhani, Ashish Sharma

Civil and Environmental Engineering Faculty Publications and Presentations

Climate change is expected to have severe impacts on global hydrological cycle along with food-water-energy nexus. Currently, there are many climate models used in predicting important climatic variables. Though there have been advances in the field, there are still many problems to be resolved related to reliability, uncertainty, and computing needs, among many others. In the present work, we have analyzed performance of 20 different global climate models (GCMs) from Climate Model Intercomparison Project Phase 5 (CMIP5) dataset over the Columbia River Basin (CRB) in the Pacific Northwest USA. We demonstrate a statistical multicriteria approach, using univariate and multivariate techniques, …


College Of Engineering Senior Design Competition Fall 2015, University Of Nevada, Las Vegas Dec 2015

College Of Engineering Senior Design Competition Fall 2015, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Effects Of A Beaver Pond In Southwestern Montana On Metals Concentration And Loads, William J. Drury, Martin Lorenzo Dec 2015

Effects Of A Beaver Pond In Southwestern Montana On Metals Concentration And Loads, William J. Drury, Martin Lorenzo

Environmental Engineering

A 400-m2 beaver pond on Cabbage Gulch (Deer Lodge County, MT) was investigated for its retention of total recoverable (TR) and dissolved arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and total suspended solids (TSS) during three storm water runoff events in the summer of 2013. Water samples were collected and flow rates were measured at monitoring stations above and below the pond. Decreases in TR metals concentrations were -17 percent for As (that is, As concentrations increased), 10 percent for Cu, 7 percent for Pb, and 27 percent for Zn. Total recoverable metals retained in the …


Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen Dec 2015

Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Sustainability has become an important factor in the chemical process and energy industries with a strong drive for process improvements towards more environmentally conscious solutions. However, there are many ways of defining sustainability and even more ways of trying to determine how sustainable a process is. This work looks into applying a conjunction of tools including; process simulation, multi-criteria decision matrices and life-cycle assessment to more quantitatively determine sustainability metrics. We have applied these tools for the production of electricity, methanol and dimethyl ether. A novel method of electricity production, in chemical looping combustion (CLC), was used that inherently involves …


Assessing The Water Quality Benefits Of Green Infrastructure Stormwater Control Measures., Sam Abdollahian Dec 2015

Assessing The Water Quality Benefits Of Green Infrastructure Stormwater Control Measures., Sam Abdollahian

Electronic Theses and Dissertations

Permeable pavements systems and tree boxes are a common type of Green Infrastructure (GI) Stormwater Control Measures (SCMs) that are often used for mitigating the stormwater runoff. In this study two permeable pavement systems and a tree box installed along parking lanes of an urban street in Louisville, KY, were investigated to evaluate their performance on improving stormwater runoff quality. The water quality monitoring was accomplished by analysis of samples collected from stormwater runoff and the captured stormwater volume at the bottom of the permeable pavements’ sub-base reservoir and by a drain gauge (lysimeter) installed in the tree box. Pollutants …


Electrochemical Enhancement Of Butanol Production And Xylose Consumption In Pure And Mixed Culture Fermentations, Jovan Popovic Dec 2015

Electrochemical Enhancement Of Butanol Production And Xylose Consumption In Pure And Mixed Culture Fermentations, Jovan Popovic

All Dissertations

The volatility of foreign and domestic petroleum markets has prompted initiatives for the development of alternative liquid energy carriers which have the capacity to accommodate our current transportation infrastructure. Butanol, which has an energy density similar to that of gasoline and can be produced through the fermentation of carbohydrates by solventogenic Clostridia, has been investigated as a supplement or direct replacement to gasoline. However, most butanol fermentations rely on glucose as a feedstock which is in direct competition with our food supply, and this requires the exploration of alternative fermentable substrates. This study investigates the use of electrochemical fermentation modifications …


Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts Dec 2015

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO2-supplemented raceway ponds, each with a 33-m2 surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …


Two-Phase Anaerobic Digestion To Reduce The Nox Emission Potential Of Biogas, Nathaniel Manuel Olivas Dec 2015

Two-Phase Anaerobic Digestion To Reduce The Nox Emission Potential Of Biogas, Nathaniel Manuel Olivas

Master's Theses

Anaerobic digestion can be used to decrease the mass of organic wastes to be disposed of while producing useful biogas (CH4 and CO2) for heat or power production, but in air basins with strict emissions limits, biogas combustion is difficult to implement due to the high costs of controlling NOx emissions. NOx production can be minimized by blending H2 gas with CH4 at a volume ratio of 15:85 H2:CH4, which allows burning at ultra-lean air-to-fuel ratios. For biogas systems, a potential low-cost NOx control strategy is to produce H2-CH …


Resource Recovery Through Halophyte Production In Marine Aquaponics: An Evaluation Of The Nutrient Cycling And The Environmental Sustainability Of Aquaponics, Suzanne Boxman Nov 2015

Resource Recovery Through Halophyte Production In Marine Aquaponics: An Evaluation Of The Nutrient Cycling And The Environmental Sustainability Of Aquaponics, Suzanne Boxman

USF Tampa Graduate Theses and Dissertations

Aquaculture, the farming of aquatic animals and plants, is an important component of global food production, which supplies a nutritious protein source for millions of people. Interest in improving the sustainability of aquaculture has led to the development of aquaponics in which fish production is combined with plant production to create zero-discharge systems. A need for more fundamental science and engineering research on marine aquaculture and growing interest in production of halophytes motivated this novel research on marine aquaponics. One objective was to evaluate the growth and nutrient removal capacity of halophytes in marine aquaponics. Bench-scale studies were conducted to …


Ammonium Removal From High Strength Wastewater Using A Hybrid Ion Exchange Biological Process, Veronica Ester Aponte-Morales Nov 2015

Ammonium Removal From High Strength Wastewater Using A Hybrid Ion Exchange Biological Process, Veronica Ester Aponte-Morales

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion (AD) has been shown to be an effective technique for energy recovery and stabilization of livestock wastes, municipal sludges and industrial wastewaters. However, further treatment is required to remove nitrogen from AD effluents to avoid detriments to surface and ground waters. The high free ammonia (FA) concentrations present in AD effluents can inhibit nitrification processes in conventional biological nitrogen removal (BNR) systems. The overall goal of this research was to develop a process for removal of nitrogen from AD swine waste (ADSW) effluent. The proposed solution was to incorporate particulate chabazite, which has a high cation exchange capacity, …


Pathogen Removal In Natural Wastewater Treatment And Resource Recovery Systems: Solutions For Small Cities In An Urbanizing World, Matthew Eric Verbyla Nov 2015

Pathogen Removal In Natural Wastewater Treatment And Resource Recovery Systems: Solutions For Small Cities In An Urbanizing World, Matthew Eric Verbyla

USF Tampa Graduate Theses and Dissertations

Sanitation, renewable energy, and food security are among the most pressing global development needs of the century, especially for small cities with rapid population growth. Currently, 53% of the world’s population either lacks access to improved sanitation or discharges fecal waste to the environment without treatment. Furthermore, 80% of food consumed in developing regions is produced by 500 million small farms, and while many of them are still rain-fed, irrigated agriculture is increasing. The post-2015 Sustainable Development Goals, recently adopted by the United Nations, include targets to address the water-energy-food nexus. Wastewater reuse in agriculture can be an important solution …


Evaluating Corrosion Resistance Of Reinforcing Steel In A Novel Green Concrete, Andrea Carolina Ramirez Nov 2015

Evaluating Corrosion Resistance Of Reinforcing Steel In A Novel Green Concrete, Andrea Carolina Ramirez

USF Tampa Graduate Theses and Dissertations

Reinforced concrete structures are expected to have a long service life with minimal maintenance. Corrosion of reinforcing steel is a major factor in reducing concrete structure lifespan, as corrosion products occupy a larger volume than that of the consumed steel and generate tensile stresses that crack the concrete cover. Procedures to control corrosion in traditional concrete, which is made with Portland-cement (PC), have been well established. However, in recent years novel concrete materials based on alternatives to normally cured PC have been developed in response to global needs to reduce greenhouse gases emissions. In particular, a promising new cement has …


Weighting The Perceived Importance Of Minimising Economic, Social, And Environmental/Cultural Risks In Flood Risk Management, Zeinab Bedri, John O'Sullivan Nov 2015

Weighting The Perceived Importance Of Minimising Economic, Social, And Environmental/Cultural Risks In Flood Risk Management, Zeinab Bedri, John O'Sullivan

Reports

A new national flood policy adopted in Ireland in 2004 set out that a range of flood-related impacts should be taken into account in planning flood risk management strategies and projects, including impacts on people, properties, the environment and cultural heritage. This was reinforced by the 2007 EU 'Floods' Directive that is aimed at the reduction of adverse consequences of flooding for human health, the environment, cultural heritage and economic activity.

In 2006, the Office of Public Works (OPW) began the National Catchment-based Flood Risk Assessment and Management (CFRAM) Programme through a series of pilot studies. A Multi-Criteria Analysis (MCA) …


Gc/Ms Analysis Of Some Extractives From Eichhornia Crassipes, Héctor A. Fileto-Pérez, O. Miriam Rutiaga-Quiñones, Mark D. Sytsma, Isabelle M. Lorne, Wentai Luo, James F. Pankow, José G. Rutiaga-Quiñones Nov 2015

Gc/Ms Analysis Of Some Extractives From Eichhornia Crassipes, Héctor A. Fileto-Pérez, O. Miriam Rutiaga-Quiñones, Mark D. Sytsma, Isabelle M. Lorne, Wentai Luo, James F. Pankow, José G. Rutiaga-Quiñones

Environmental Science and Management Faculty Publications and Presentations

Eichhornia crassipes (water hyacinth) is an invasive weed that causes serious issues for rivers, lakes, and other reservoirs around the world, although it can be an excellent source for bioactive compounds such as phytosterols and some steroids found in many plants. In this study, water hyacinth samples from both Durango and Distrito Federal in Mexico were collected. Ascendant extracts (cyclohexane, hexane, acetone, and methanol) from their leaves, stems, and roots were analyzed. Using boron trifluoride (similar to 10% [similar to 1.3 M] in 1-butanol), all extracts were derivatized. Twenty-four derivatized samples were analyzed using a gas chromatography-mass spectrometry (GC/MS) method. …


An Upscaled Approach For Transport In Media With Extended Tailing Due To Back-Diffusion Using Analytical And Numerical Solutions Of The Advection Dispersion Equation, Jack C. Parker, Ungtae Kim Nov 2015

An Upscaled Approach For Transport In Media With Extended Tailing Due To Back-Diffusion Using Analytical And Numerical Solutions Of The Advection Dispersion Equation, Jack C. Parker, Ungtae Kim

Civil and Environmental Engineering Faculty Publications

The mono-continuum advection-dispersion equation (mADE) is commonly regarded as unsuitable for application to media that exhibit rapid breakthrough and extended tailing associated with diffusion between high and low permeability regions. This paper demonstrates that the mADE can be successfully used to model such conditions if certain issues are addressed. First, since hydrodynamic dispersion, unlike molecular diffusion, cannot occur upstream of the contaminant source, models must be formulated to prevent “back-dispersion.” Second, large variations in aquifer permeability will result in differences between volume-weighted average concentration (resident concentration) and flow-weighted average concentration (flux concentration). Water samples taken from wells may be regarded …


Ion Exchange-Precipitation For Nutrient Recovery From Dilute Wastewater, A. T. Williams, Daniel Zitomer, Brooke K. Mayer Nov 2015

Ion Exchange-Precipitation For Nutrient Recovery From Dilute Wastewater, A. T. Williams, Daniel Zitomer, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Regulated phosphorus (P) and nitrogen (N) discharges and the cost of fertilizer provide economic drivers for nutrient removal and recovery from wastewater. This study used ion exchange (IX) in dilute (domestic) wastewater to concentrate nutrients with subsequent recovery by struvite precipitation. This is the first tertiary wastewater treatment study directly comparing P removal using a range of Fe, Cu, and Al-based media followed by clinoptilolite IX columns for N removal and precipitation using the combined regenerants. Phosphate removal prior to breakthrough was 0.5–2.0 g P Lmedia−1, providing effluent concentrations −1 PO4-P and −1 NH4 …


Review Of Robotic Technology For Strawberry Production, S. G. Defterli, Yeyin Shi, Yunjun Xu Nov 2015

Review Of Robotic Technology For Strawberry Production, S. G. Defterli, Yeyin Shi, Yunjun Xu

Department of Agricultural and Biological Systems Engineering: Faculty Publications

With an increasing world population in need of food and a limited amount of land for cultivation, higher efficiency in agricultural production, especially fruits and vegetables, is increasingly required. The success of agricultural production in the marketplace depends on its quality and cost. The cost of labor for crop production, harvesting, and post-harvesting operations is a major portion of the overall production cost, especially for specialty crops such as strawberry. As a result, a multitude of automation technologies involving semi-autonomous and autonomous robots have been utilized, with an aim of minimizing labor costs and operation time to achieve a considerable …