Engineering Commons^™

Experiments On Column Base Stiffness Of Long-Span Cold-Formed Steel Portal Frames Composed Of Double Channels, H. B. Blum, K. J. R. Rasmussen

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Cold-formed steel haunched portal frames are popular structures in industrial and housing applications. They are mostly used as sheds, garages, and shelters, and are common in rural areas. Cold-formed steel portal frames with spans of up to 30m (100 ft) are now being constructed in Australia. As these large structures are fairly new to the market, there is limited data on their feasibility and design recommendations. An experimental program was carried out on a series of portal frame systems composed of back-to-back channels for the columns, rafters, and knee braces. The system consisted of three frames connected in parallel with …

Ocean–Atmosphere Interactions Modulate Irrigation’S Climate Impacts, Nir Y. Krakauer, Michael J. Puma, Benjamin I. Cook, Pierre Gentine, Larisa Nazarenko

Publications and Research

Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean– atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity.We find that ocean–atmosphere interaction does impact the magnitude of globalmean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, …

Pepper Mild Mottle Virus As A Surrogate For Enteric Viruses: Implications For Assessing Water Quality, Erin Michelle Symonds

USF Tampa Graduate Theses and Dissertations

Less than 10% of the world’s domestic wastewater is disinfected prior to discharge into surface waters; therefore, human exposure to diverse wastewater-related pathogens results in millions of cases of illness each year. Among the enteric pathogens, viruses represent an important group of emerging pathogens and are frequently the cause of food- and water-borne outbreaks of illness. Although the World Health Organization and many government agencies mandate the use of bacterial indicators to identify poor microbial water quality, it is well known that these indicators poorly correlate with fecal pollution contamination events and risk of disease. The field of public health-related …

Climate Change And The Delta, San Francisco Estuary And Watershed Science, Michael D. Dettinger, Jamie Anderson, Michael L. Anderson, Larry R. Brown, Daniel R. Cayan, Edwin P. Maurer

Civil, Environmental and Sustainable Engineering

Anthropogenic climate change amounts to a rapidly approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in different ways that are characterized by different levels of uncertainty. For example, there is high certainty that climate will warm by about 2°C more (than late-20th-century averages) by mid-century and about 4°C by end of century, if greenhouse-gas emissions continue their current rates of acceleration. Future precipitation changes …

Exploring Access To Portable Water And Sanitation Practices In A Post-Conflict Environment: The Case Of Gulu District, Northern Uganda, Peyton Going

Independent Study Project (ISP) Collection

Over the course of 30 days of fieldwork in October and November of 2016, data was collected through interviews conducted with local government officials, researchers and academics, and village community members of Gulu District.

The aim of this study was to determine the extent to which agencies have improved water and sanitation in the region. The case study of Gulu utilized in-depth interviews with key informants, focus groups, and observations, and sought to determine who the local stakeholders in water and sanitation are, the water sources and sanitation facilities available and their uses, the perception local people have about their …

Creep And Recovery Behavior Of Polymeric And Chemically Treated Asphalt Binders, Mohammed Ziaur Rahaman

Student Theses and Dissertations

For quality assurance and quality control purposes, suppliers and users of asphalt binders follow the widely used dynamic shear rheometer (DSR) test method (AASHTO T 315) to capture viscoelastic properties of polymer-modified binders (PMBs), warm mix asphalt (WMA)- and reclaimed asphalt pavement (RAP)- modified binders even though it is designed for unmodified asphalt binders. AASHTO T 315 is inadequate to characterize the aforementioned binders because of the relatively small impact of the phase angle and strain levels on the rutting and fatigue factors, respectively. The recently balloted multiple stress creep recovery (MSCR) test (AASHTO T 350) results can better relate …

Post-Liquefaction Residual Strength Assessment Of The Las Palmas, Chile Tailings Failure, Tristan Reyes Gebhart

Master's Theses

Assessment of post-liquefaction residual strength is needed for the development of empirically-based, predictive correlations for earthquake engineering design. Previous practice commonly assigned negligible strengths to liquefied materials for engineering analysis, producing overly-conservative designs. Increasingly available case history data, and improved analytical tools have allowed for more accurate and less overly-conservative estimation of soil residual strength, improving empirical predictive models. This study provides a new case history to the limited suite of (approximately 30) liquefaction failure case histories available for post-liquefaction in-situ strength predictive correlations.

This case history documents the Las Palmas gold mine tailings dam failure, resulting from seismic-induced liquefaction …

The Feasibility Of Utilising Compressed Natural Gas As Part Of A Systematic Approach To Establishing The Necessary Groundwork For The Hydrogen Based Transport Economy, James Brunton, John Howlett, David Kennedy

Conference Papers

One key objective for vehicle manufacturers is to develop technology and infrastructure to facilitate the progression from combustion to conversion by the year 2050. In the short to medium term however, the combustion of fossil fuels such as petrol and diesel, coupled with advanced transmission innovations and emission control technology that are governed by strict Euro VI regulations appears to be the main path forward for the transport sector and the environment. This paper presents the feasibility of utilising the developing compressed natural gas network capabilities as part of a systematic approach to establishing the necessary groundwork for a hydrogen …

Scientific Review Report, J D. Rossouw, M Musariri

Policy

This report provides the Scientific Review results and recommendations regarding the existing surface and groundwater monitoring sites for all nine Water Management Areas following the Regional WMA Network Design Workshops held in Nelspruit, Cape Town, Durban,King Williams Town, Bela-Bela and Bloemfontein from March to June 2016. During these workshops theoretical monitoring network considerations for each WMA were presented to various stakeholders, and the considerations were used to review the existing networks and obtain changes and improvements to the networks as recommendations. The main objectives of the workshops were to review the existing monitoring networks against the prioritized National Monitoring Objectives …

Evaluation Of Food Waste Diversion Potential And Economics Of Using Food Waste Dehydrators, Arindam Dhar

Civil Engineering Theses - Archive

According to US EPA (2013), food waste is the second largest component (14.6%) of MSW composition in the US, preceded only by paper. Apart from the negative environmental impacts of food waste through methane and leachate generation, it also incurs huge cost to landfill them. Hence, food waste diversion from landfills is becoming a major issue in landfills across many US states. Though biological treatment of food waste is a potential alternative for food waste diversion, the existing scale of this type of treatment is very narrow. On-site treatment of food waste is a suitable alternative as it can be …

E3.Pt – An E3 Portabledyme Model For Portugal, Anett Großmann, Frank Hohmann

International Congress on Environmental Modelling and Software

E3 models are environmentally extended economic models. They are extensively used for impact assessment of energy, climate and resource policies at national and international level. E3 models have proven to be suitable tools for quantifying effects on the economy, environment and energy system. Usually, the structure and documentation of such models are only accessible by the model builders. They are facing the allegation to be a "black box" meaning that only their creators are able to operate and fully understand the model system. Decision makers are often only engaged at the end of the model building process to discuss the …

A Framework For Decision-Making In Cases Of Invasive Species, Peter A. Khaiter, Marina G. Erechtchoukova, Sina Roushan

International Congress on Environmental Modelling and Software

Invasion of nonindigenous species is one of the most pressing global challenges, causing substantial environmental, economic and social harm. Invasion of alien species alters the composition, structure and functioning of invaded ecosystems as well as the services they generated before the invasion. Decisions about the management of invasive cases are inherently difficult because of the multifactorial and multiattribute scope of the problem. In particular, the resilience limits of invaded ecosystems to fully recover original, pre-invaded states remain unclear. To facilitate management efforts, decision-makers and environmental practitioners require a framework integrating relevant knowledge and acting as a supporting expert system. The …

Simulating Spatial Changes In Vegetation-Livestock Interactions Under Different Landscape Structures: A Multi-Agent System Applied To Agro-Pastoral Territories, Mamadou Sané, Jonathan Vayssières, Myriam Grillot, Alassane Bah, Alexandre Ickowicz

International Congress on Environmental Modelling and Software

Free-range and common-grazing ruminants play a major role in the functioning and the provision of ecosystem services by agro- and silvo-pastoral ecosystems in sub-Saharan Africa. To assess how landscape structure affects the nature of environment-herd-services interactions, this paper describes a Multi-Agent System (MAS) that simulates daily herd movements in a dynamic environment. The model is used to study how the overall productivity of an agricultural territory is affected by the spatial organization of its different landscape units. The originality of this model lies in fine representation, in hourly time steps, of a herd’s movements and activities over the seasons depending …

Evapotranspiration Mapping Using Sebal Algorithms To Account For Agricultural Water Uses In The Upper Pangani, Tanzania, Anna Msigwa, Ann Van Griensven, Hans C. Komakech, Boud Verbeiren, Tim Hessels, Wim G. M. Bastiaanssen

International Congress on Environmental Modelling and Software

To make informed decisions, river basin managers requires information on demands and actual usage from different sectors in the basin. Such water use information has to be adequate in terms of quantities used per sector, where and when. However, because of high costs of maintaining equipment for monitoring use, it is very difficult to obtain this information in developing arid and semi- arid areas of Sub-Saharan Africa. The use of proxy method such as calculation of evapotranspiration is proposed as a cheaper means for such data acquisition. Water consumption through crop evapotranspiration (ET) is a major component of water withdrawal, …

Up In The Air: Understanding Vulnerability When Toilets Fly, Amy Krakowka Richmond, Suzanne Pierce, Sethi Gautam

International Congress on Environmental Modelling and Software

Across sub-Saharan Africa, both natural and social factors contribute to household level vulnerability. This case study focuses specifically on Uganda, which has made progress towards meeting the United Nation’s Millennium Development Goals, most notably halving the proportion of the population that is below the poverty line. Despite these impressive achievements, many households remain vulnerable to multiple social and environmental stressors. A better understanding of the drivers of household level vulnerability will assist stakeholders and policy-makers in determining what drives vulnerability at a household level, where vulnerable populations are, and suggest what type of aid to target specific locations to be …

Hindcasting The Dynamics Of An Eastern Mediterranean Marine Ecosystem Under The Impacts Of Multiple And Cumulative Stressors, X. Corrales, M. Coll, E. Ofir, M. Goren, D. Edelist, J. J. Heymans, G. Gal

International Congress on Environmental Modelling and Software

An important challenge for conserving and managing marine ecosystems is to advance our understanding of how multiple human stressors, environmental factors and marine resources interact and influence each other. The ecosystems of the Israeli Mediterranean coast have undergone significant ecological changes in recent decades caused primarily by the introduction of invasive species through the Suez Canal, intense fishing activities and the effects of climate change. An Ecopath model representing the continental shelf of the Israeli Mediterranean coast was calibrated and fitted to the available time series from early 1990’s to 2010 using the Ecosim temporal dynamic modeling approach. The model …

Application Of The Swat Model To Investigate Surface Runoff And Nitrate Flux Towards The Mediterranean Sea: Case Of The Tafna Catchment (North-West Of Africa), Amin Zettam, Amina Taleb, Sabine Sauvage, José Miguel Sanchez-Perez, Laurie Boithias, Nouria Belaidi

International Congress on Environmental Modelling and Software

Water in North-West of Africa is an increasingly valuable resource due to high competition between agriculture, industry and drinking water supply, accentuated by frequent drought conditions in a semi-arid climate. For a few decades, the demographic explosion, the development of agriculture and industry, and the building of water infrastructures (dams) have modified the water fluxes and the biogeochemical cycle of nitrogen towards an increased production of nitrates in waters. The objectives of this study are to propose a modelling approach to quantify the contribution of the Tafna coastal watershed (North-West of Africa) to the flux of nitrates into the Mediterranean …

From Research Data To Web-Based Policy Tools: User-Centered Design Techniques In The Development Of The Agmip Impacts Explorer, Joske Houtkamp, Inge La Rivière, Hugo De Groot, Sander Janssen, Arjan De Jong

International Congress on Environmental Modelling and Software

decision making through a web-based tool is a complex challenge. Research projects are generally not designed to meet the information needs of specific stakeholder groups. Furthermore, tools developed in these projects are usually intended to disseminate research data on a wide scale, not to provide answers to specific questions of these stakeholders. User-centered design techniques can guide the development process of such tools, to enhance their usefulness and thus the applicability of the research outcomes for the intended audience. We applied techniques for user requirements analysis of the Impacts Explorer tool in the AgMIP research project, which models the impacts …

The Validation Of Algal Growth Processes In A Water Quality Model Using Remote Sensing Data, A. R. Slaughter, S. K. Mantel

International Congress on Environmental Modelling and Software

The Water Quality Systems Assessment Model (WQSAM) uses the concept of requisite simplicity within the context of modelling water quality of data scarce South African surface waters. Although WQSAM has successfully simulated the frequency distribution of observed historical nutrient data for various catchments in South Africa, the validation of algal and macrophyte growth processes in the model is a challenge because of a lack of observed data. Remote sensing data can provide an estimate of algal growth within reservoirs. Therefore, this study aimed to validate the WQSAM simulations of algal growth using remote sensing estimations of primary production in reservoirs. …

Modelling Social Ecological Dynamics With Transfers Of Vulnerability And Robustness. Examples With Adaptation To Coastal Vulnerability, Olivier Barreteau, J. Marty Anderies, Bruno Bonté, Pauline Brémond, Frédéric Grelot, Chloé Guerbois, Tara Quinn

International Congress on Environmental Modelling and Software

Adaption patterns undertaken by policy makers within their own jurisdiction may bump in adaptation patterns undertaken by others at their own level. The consequences of these interactions may lead to mutual reinforcement or to cancelling each policy maker’s adaptation capacity. In this presentation, we consider following Anderies (2014) that autonomous SES have their own adaptive management as an autonomous feedback loop. We take on seriously the concept of pluralism of agency in SES: any goal can be used as the root for a specific feedback loop. We identify the interactions between these loops to characterize transfers of vulnerability or robustness …

On The Use Of Finite-Difference Model To Evaluate The Impact Of Underground Water Overexploitation, Hani A., Bougherira N., Djabri L., Chaffai H., Lallahem S.

International Congress on Environmental Modelling and Software

The potentiometric surface in the Annaba basin, which covers an area of 264 km², has declined significantly since 1995. A transient multilayer model has been developed to synthesise the hydrologic data. The groundwater flow was modelled using the finite difference method with a horizontal dimension of 500 x 500 m for the cells. The model consists of two layers, the first corresponding to the alluvial phreatic aquifer and the second to the deep confined aquifer, and is calibrated against the steady state groundwater heads recorded before 1996. Under steady-state conditions, the correspondence between simulated and observed water levels …

Government Motivation-Embedded Return Guarantee For Urban Infrastructure Projects Based On Real Options, Qingpeng Man, Chengshuang Sun, Yuesheng Fei, Martin Skitmore, Yong Bai, Weizhuo Lu

Civil and Environmental Engineering Faculty Research and Publications

Governments usually guarantee the amount of investment income to private sector partners to encourage their participation in Public-Private Partnership urban infrastructure development projects, with the ‘float return on investment guarantee’ being the main method in use by the Chinese government today. The current problems with the float return on investment guarantee are analysed and a guarantee approach with embedded motivational behaviour is presented as an alternative. A pricing method option is then introduced as the motivation-embedded return guarantee has similar characteristics to real options. From this, a valuation model is developed that provides the basis of a new systematic method …

Groundwater Recharge And Associated Uncertainty Estimation Combining Multi-Method And Multi-Scale Approaches, S. Lanini, Y. Caballero

International Congress on Environmental Modelling and Software

Groundwater resource assessment is a major concern for water managers who have to balance water demands and resources at a basin or territory scale. One operational way to address this question is to estimate the part of recharge which is linked to precipitation. Many methods to estimate groundwater recharge are described in the literature, varying in terms of time scale and the nature of the data they treat. They do not always provide a suitable estimate of uncertainty. To obtain both a realistic estimation of groundwater recharge and a confidence interval at the hydrogeological basin scale, we propose a multi-method …

An Integrated Modelling Approach To Climate Change And Malaria Vulnerability Assessments, Esther Achieng Onyango, Oz Sahin, Cordia Chu, Brendan Mackey

International Congress on Environmental Modelling and Software

Malaria is one of the key research concerns in climate change-health relationships. Numerous risk assessments and modelling studies providing evidence that the transmission range of malaria will expand with rising temperatures resulting in adverse impacts on vulnerable communities. This risk is significant in East Africa whereby current research shows an expansion of malaria into the highland areas due to changes in temperature and rainfall. While there exist multiple lines of evidence for the influence of climate change on malaria and the risk posed to vulnerable communities, there is insufficient understanding of the complexity of factors influencing the spread of the …

Using Sddp To Perform Basin-Wide Water Resources Assessments With Limited Data Availability, Charles Rougé, Amaury Tilmant

International Congress on Environmental Modelling and Software

In many situations, water resources assessments are hindered by the limited availability of data concerning both water supplies and demands. Stochastic dual dynamic programming (SDDP) is one of few solutions available to determine optimal allocation policies in large-scale water resources systems. Yet, limited data on water demands and hydraulic infrastructure leads to the existence of multiple near-optimal solutions (MNOS). This work shows that when MNOS exists, SDDP is very sensitive to even minimal variations of the problem setting, e.g. initial conditions – we call this “algorithmic chaos”. Besides, the approximations of the benefit-to-go function that SDDP constructs at each stage …

Methane Extraction From Lake Kivu: A Case Study For Model-Based Policy, Martin Schmid, Alfred Wüest

International Congress on Environmental Modelling and Software

Lake Kivu in East Africa contains enormous amounts of dissolved carbon dioxide and methane. The dissolved methane is increasingly used as a resource to produce electricity, with two power plants currently in operation and several additional facilities in planning. The design of such gas extraction facilities needs to take into account possible negative impacts: if badly designed, the extraction could disturb the lake’s permanent density stratification and thus risk to create a catastrophic gas eruption; and it could increase nutrient fluxes from the deep water to the surface layers, leading to eutrophication and related negative consequences for the ecosystem, fisheries …

Development Of A Decentralized And Off-Grid Anaerobic Membrane Bioreactor (Anmbr) For Urban Sanitation In Developing Countries, Robert Alonso Bair

USF Tampa Graduate Theses and Dissertations

Urbanization has led to rapid and uncontrolled growth of informal housing settlements in many developing countries. As most slum growth is unplanned, these areas tend to lack basic infrastructure including sanitation. The high user rates, lack of water and electricity infrastructure, space limitations, and scant financial resources make sanitation provision a major challenge in slums. As most decentralized sanitation technologies fail when applied in these environments, better technologies need to be developed that cater to the specific needs of slum dwellers. One promising technology, the membrane bioreactor (MBR) is routinely used in developed countries when a compact and resilient treatment …

Cfd Study Of Decay Function Of Wall Shear Stress With Scour Around Complex-Shape Bridge Pier, Chen Li

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Pier scour problem is close related to the safety of bridges. The Federal Highway Administration of the United State also has a great interest in studying the relation between hydraulic loadings and scour depth. The current technological problem of directly measuring hydraulic loadings on a dynamic bed using physical experiments and the weak capacity to simulate the real scour processes with CFD methods inspired the development of a hybrid approach by combining them to study pier scour.

This research specifically focuses on the CFD part of the hybrid method. A series of three-dimensional (3-D) CFD models were developed with unsteady …

Use Of Cycling Paths Along The Morogoro Brt Line, Ford Sanger

Independent Study Project (ISP) Collection

As the urban population continues to increase rapidly in Dar es Salaam it will become increasingly important to find sustainable means of urban transportation. With planned infrastructure improvements in the city to help alleviate traffic congestion, bicycles, which represent a largely underutilized form of urban transportation, have the potential to play a large role in the future of the city. Through background research, direct observations, community surveys, and interviews, both formal and informal, this study sought to understand the impact of the recent addition of bike lanes along the first phase of the Dar Bus Rapid Transit line. It was …

A Tool For Downscaling Weather Data From Large-Grid Reanalysis Products To Finer Spatial Scales For Distributed Hydrological Applications, Avirup Sen Gupta, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

A downscaling tool was developed to provide sub-daily high spatial resolution surfaces of weather variables for distributed hydrologic modeling from NASA Modern Era Retrospective-Analysis for Research and Applications reanalysis products. The tool uses spatial interpolation and physically based relationships between the weather variables and elevation to provide inputs at the scale of a gridded hydrologic model, typically smaller (∼100 m) than the scale of weather reanalysis data (∼20–200 km). Nash-Sutcliffe efficiency (NSE) measures greater than 0.70 were obtained for direct tests of downscaled daily temperature and monthly precipitation at 173 SNOTEL sites. In an integrated test driving the Utah Energy …