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University of Nevada, Las Vegas

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Sustainability

Civil and Environmental Engineering and Construction Faculty Research

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Evaluating Irrigation Performance And Water Productivity Using Eeflux Et And Ndvi, Usha Poudel, Haroon Stephen, Sajjad Ahmad Jul 2021

Evaluating Irrigation Performance And Water Productivity Using Eeflux Et And Ndvi, Usha Poudel, Haroon Stephen, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Southern California’s Imperial Valley (IV) faces serious water management concerns due to its semi-arid environment, water-intensive crops and limited water supply. Accurate and reliable irrigation system performance and water productivity information is required in order to assess and improve the current water management strategies. This study evaluates the spatially distributed irrigation equity, adequacy and crop water productivity (CWP) for two water-intensive crops, alfalfa and sugar beet, using remotely sensed data and a geographical information system for the 2018/2019 crop growing season. The actual crop evapotranspiration (ETa) was mapped in Google Earth Engine Evapotranspiration Flux, using the linear interpolation method in …

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Estimation Of Performance Indices For The Planning Of Sustainable Transportation Systems, Alexander Paz, Pankaj Maheshwari, Pushkin Kachroo, Sajjad Ahmad Jan 2013

Estimation Of Performance Indices For The Planning Of Sustainable Transportation Systems, Alexander Paz, Pankaj Maheshwari, Pushkin Kachroo, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

In the context of sustainable transportation systems, previous studies have either focused only on the transportation system or have not used a methodology that enables the treatment of incomplete, vague, and qualitative information associated with the available data. This study proposes a system of systems (SOS) and a fuzzy logic modeling approach. The SOS includes the Transportation, Activity, and Environment systems. The fuzzy logic modeling approach enables the treatment of the vagueness associated with some of the relevant data. Performance Indices (PIs) are computed for each system using a number of performance measures. The PIs illustrate the aggregated performance of …

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Losing The Lake: Development And Deployment Of An Educational Game, Joseph M. Vesco, Katie Gilgen, Anne Paine, Marissa Owens, Michael Nussbaum, Gale M. Sinatra, Sajjad Ahmad, Kent J. Crippen, Sergiu Dascalu, Frederick C. Harris Mar 2012

Losing The Lake: Development And Deployment Of An Educational Game, Joseph M. Vesco, Katie Gilgen, Anne Paine, Marissa Owens, Michael Nussbaum, Gale M. Sinatra, Sajjad Ahmad, Kent J. Crippen, Sergiu Dascalu, Frederick C. Harris

Civil and Environmental Engineering and Construction Faculty Research

When asked what the top three issues of the Las Vegas region were, the reply was “water, water, water!" This was the result of a survey done a few years ago of Las Vegas Valley TV anchors. The reason for this response is that sustainability of the urban environments requires sufficient water resources as does population growth. With the advent of global climate change, this resource is in danger. Water flow and mountainous ice packs are impacted by this change in climate there by impacting the amount of water the the region. This is compounded over time as the population …

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Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke Jan 2007

Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke

Civil and Environmental Engineering and Construction Faculty Research

Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this …

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Creep And Creep-Recovery Models For Wood Under High Stress Levels, Zhiyong Cai, Kenneth J. Fridley, Michael O. Hunt, David V. Rosowsky Jul 2002

Creep And Creep-Recovery Models For Wood Under High Stress Levels, Zhiyong Cai, Kenneth J. Fridley, Michael O. Hunt, David V. Rosowsky

Civil and Environmental Engineering and Construction Faculty Research

Forty small clear southern pine specimens were loaded under third-point bending to examine creep and creep-recovery behavior for wood under high stress levels. Stress levels of between 69% and 91% of the predicted static strength were applied for 23 h with 1 h allowed for recovery, and the resulting deflection vs. time behavior was studied. The experimental creep and creep-recovery behavior was modeled using modified power law functions. The results indicate that these functions provide the best fit to both primary and secondary experimental data. The empirical models can be used to simulate the viscoelastic behavior of wood under high …

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