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Physical Sciences and Mathematics

2017

University of Nebraska - Lincoln

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Articles 31 - 60 of 77

Full-Text Articles in Engineering

Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran Jan 2017

Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran

CSE Technical Reports

In this paper, a novel framework for underground beamforming using adaptive antenna arrays is presented. Based on the analysis of propagation in wireless underground channel, a theoretical model is developed which uses soil moisture information and feedback mechanism to improve performance wireless underground communications. Array element in soil has been analyzed empirically and impacts of soil type and soil moisture on return loss and resonant frequency are investigated. Beam patterns are investigated to communicate with both underground and above ground devices. Depending on the incident angle, refraction from soil-air interface has the adverse effects in the UG communications. It is …


Wireless Underground Channel Diversity Reception With Multiple Antennas For Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran Jan 2017

Wireless Underground Channel Diversity Reception With Multiple Antennas For Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran

CSE Conference and Workshop Papers

Internet of underground things (IOUT) is an emerging paradigm which consists of sensors and communication devices, partly or completely buried underground for real-time soil sensing and monitoring. In this paper, the performance of different modulation schemes in IOUT communications is studied through simulations and experiments. The spatial modularity of direct, lateral, and reflected components of the UG channel is exploited by using multiple antennas. First, it has been shown that bit error rates of $10^{-3}$ can be achieved with normalized delay spreads ($\tau_d$) lower than $0.05$. Evaluations are conducted through the first software-defined radio-based field experiments for UG channel. Moreover, …


Towards Internet Of Underground Things In Smart Lighting: A Statistical Model Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak Jan 2017

Towards Internet Of Underground Things In Smart Lighting: A Statistical Model Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak

CSE Conference and Workshop Papers

The Internet of Underground Things (IOUT) has many applications in the area of smart lighting. IOUT enables communications in smart lighting through underground (UG) and aboveground (AG) communication channels. In IOUT communications, an in-depth analysis of the wireless underground channel is important to design smart lighting solutions. In this paper, based on the empirical and the statistical analysis, a statistical channel model for the UG channel has been developed. The parameters for the statistical tapped-delay-line model are extracted from the measured power delay profiles (PDP). The PDP of the UG channel is represented by the exponential decay of the lateral, …


Compensatory Response Of Fathead Minnow Larvae Following A Pulsed In-Situ Exposure To A Seasonal Agricultural Runoff Event, Jonathan M. Ali, John Sangster, Daniel D. Snow, Shannon L. Bartelt-Hunt, Alan S. Kolok Jan 2017

Compensatory Response Of Fathead Minnow Larvae Following A Pulsed In-Situ Exposure To A Seasonal Agricultural Runoff Event, Jonathan M. Ali, John Sangster, Daniel D. Snow, Shannon L. Bartelt-Hunt, Alan S. Kolok

Nebraska Water Center: Faculty Publications

Agriculturally-dominated waterways such as those found throughout the Midwestern United States often experience seasonal pulses of agrichemical contaminants which pose a potential hazard to aquatic organisms at varying life stages. The objective of this study was to characterize the developmental plasticity of fathead minnow larvae in a natural environment subject to a seasonal episodic perturbation in the form of a complex mixture of agricultural stressors. Fathead minnow larvae were maintained at the Elkhorn River Research Station for a 28-d in situ exposure to an agrichemical pulse event.Minnow larvae were sampled after 14 and 28 days to characterize developmental plasticity through …


Aquacrop-Os: An Open Source Version Of Fao’S Crop Water Productivity Model, T. Foster, N. Brozovic, A. P. Butler, C. M. U. Neale, D. Raes, P. Steduto, E. Fereres, T. C. Hsiao Jan 2017

Aquacrop-Os: An Open Source Version Of Fao’S Crop Water Productivity Model, T. Foster, N. Brozovic, A. P. Butler, C. M. U. Neale, D. Raes, P. Steduto, E. Fereres, T. C. Hsiao

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are valuable tools for quantifying crop yield response to water, and for devising strategies to improve agricultural water management. However, applicability of the majority of crop models is limited greatly by a failure to provide open-access to model source code. In this study, we present an open-source version of the FAO AquaCrop model, which simulates efficiently water-limited crop production across diverse environmental and agronomic conditions. Our model, called AquaCrop-OpenSource (AquaCrop-OS), can be run in multiple programming languages and operating systems. Support for parallel execution reduces significantly simulation times when applying the model in large geospatial frameworks, for …


In-Situ Observation And Transport Modelling Of Arsenic In Gangetic Plain, India, Pankaj Kumar Gupta, Pranjay Joshi, Jahangeer Jan 2017

In-Situ Observation And Transport Modelling Of Arsenic In Gangetic Plain, India, Pankaj Kumar Gupta, Pranjay Joshi, Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The focus of this study is to investigate the arsenic movement and impacts on the residual concentrations on groundwater pollution load. The Gangetic plain area in the Ballia, Uttar Pradesh is selected as study area, which is also reported to extreme arsenic pollution in soil-water system. A modelling approach is developed to assess the arsenic flux in partially saturated zone using data of soil texture, soil hydraulic properties and stratigraphy. Soil type, slope, and land-use cover is considered for estimating the transient flux at the top boundary from daily precipitation and evapotranspiration data of the study area. Solute transport in …


Paid To Pump: How A Tax Credit Could Discourage Conservation Of The High Plains Aquifer, S. Polzkill,, A. Stejskal, H. Wilke, Anna Wistrom, Katherine E. B. Gibson, Mindy J. Spiehs, Nicholas Brozovic Jan 2017

Paid To Pump: How A Tax Credit Could Discourage Conservation Of The High Plains Aquifer, S. Polzkill,, A. Stejskal, H. Wilke, Anna Wistrom, Katherine E. B. Gibson, Mindy J. Spiehs, Nicholas Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

In 1965’s United States v. Shurbet case, an irrigator from Texas asserted his claim for a depletion tax deduction for groundwater pumped from the High Plains Aquifer. He argued that the unique conditions of the southern High Plains region - a plateau where the shallow aquifer is recharged only through precipitation at a slow rate - meant the groundwater resource would be depleted in time. The state argued that groundwater was not fundamentally an exhaustible natural deposit, but the Supreme Court concluded the tax deduction was appropriate given the “peculiar” conditions in the area. It was stated the decision was …


Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance Jan 2017

Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance

Daugherty Water for Food Global Institute: Faculty Publications

Without a transformative leap forward in the use of irrigation, Africa will continue falling short in the struggle to feed its growing population, improve its people’s nutrition, grow its economies, adapt to the impacts of climate change, and eliminate poverty. While Africans must lead this transformation for it to be successful, the international community can help African countries substantially increase the use of more productive and sustainable water management practices and unlock the potential of farmer-led irrigated agriculture. Achieving highly productive irrigated agricultural systems in Africa requires an enabling environment that facilitates the full engagement of farmers, public and private …


Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran Jan 2017

Smart Underground Antenna Arrays: A Soil Moisture Adaptive Beamforming Approach, Abdul Salam, Mehmet C. Vuran

CSE Conference and Workshop Papers

Current wireless underground (UG) communication techniques are limited by their achievable distance. In this paper, a novel framework for underground beamforming using adaptive antenna arrays is presented to extend communication distances for practical applications. Based on the analysis of propagation in wireless underground channel, a theoretical model is developed which uses soil moisture information to improve wireless underground communications performance. Array element in soil is analyzed empirically and impacts of soil type and soil moisture on return loss (RL) and resonant frequency are investigated. Accordingly, beam patterns are analyzed to communicate with underground and above ground devices. Depending on the …


Biosimp: Using Software Testing Techniques For Sampling And Inference In Biological Organisms, Mikaela Cashman, Jennie L. Catlett, Myra B. Cohen, Nicole R. Buan, Zahmeeth Sakkaff, Massimiliano Pierobon, Christine A. Kelley Jan 2017

Biosimp: Using Software Testing Techniques For Sampling And Inference In Biological Organisms, Mikaela Cashman, Jennie L. Catlett, Myra B. Cohen, Nicole R. Buan, Zahmeeth Sakkaff, Massimiliano Pierobon, Christine A. Kelley

CSE Conference and Workshop Papers

Years of research in software engineering have given us novel ways to reason about, test, and predict the behavior of complex software systems that contain hundreds of thousands of lines of code. Many of these techniques have been inspired by nature such as genetic algorithms, swarm intelligence, and ant colony optimization. In this paper we reverse the direction and present BioSIMP, a process that models and predicts the behavior of biological organisms to aid in the emerging field of systems biology. It utilizes techniques from testing and modeling of highly-configurable software systems. Using both experimental and simulation data we show …


Ferroelectricity And The Phase Transition In Large Area Evaporated Vinylidene Fluoride Oligomer Thin Films, Keith Foreman, Shashi Poddar, Stephen Ducharme, Shireen Adenwalla Jan 2017

Ferroelectricity And The Phase Transition In Large Area Evaporated Vinylidene Fluoride Oligomer Thin Films, Keith Foreman, Shashi Poddar, Stephen Ducharme, Shireen Adenwalla

Shireen Adenwalla Papers

Organic ferroelectric materials, including the well-known poly(vinylidene fluoride) and its copolymers, have been extensively studied and used for a variety of applications. In contrast, the VDF oligomer has not been thoroughly investigated and is not widely used, if used at all. One key advantage the oligomer has over the polymer is that it can be thermally evaporated in vacuum, allowing for the growth of complex heterostructures while maintaining interfacial cleanliness. Here, we report on the ferroelectric properties of high-quality VDF oligomer thin films over relatively large areas on the order of mm2. The operating temperature is identified via …


Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel Jan 2017

Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel

Yaşar Demirel Publications

Introduction

First‐generation biofuels, namely, ethanol and biodiesel, have led to far reaching impact on the peoples’ life world‐wide.[1] However, they inter-fere with the food supply chain and may not be sustainable although some of the biomass are converted to biofuels after those biomasses have met the human needs. Still, the first‐generation–based biofuels have proved that sugar and lipid platforms can be an answer to energy security and global warming concerns without the need for new infrastructure for feedstock delivery as well as for biomass‐to‐biofuel conversion tech-nologies. At the same time, we are discovering and assessing the long‐term environmental im-plications on …


Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis Jan 2017

Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of the changes in land use and land cover change (LULCC) in respect to oil exploration across the Albertine region in Uganda has been focused around the exploration areas and protected areas, with no attention to the potential impacts of evictees’ activities on resettled areas. This study used LANDSAT images to analyze the land use and land cover changes (LULCC) among the period before eviction (2002 and 2005) at the climax of eviction and resettlements (2005-2011), and during the post-resettlement period (2011-2015) to quantify the impacts of resettlements on the environment. LANDSAT images were processed using ERDAS IMAGINE software …


Nebraska Public Water Supply Program Summary Report 2017 Jan 2017

Nebraska Public Water Supply Program Summary Report 2017

Nebraska Department of Environmental Quality: Reports

The United States Environmental Protection Agency (EPA) established the Public Water System Supervision (PWSS) Program under the authority of the 1974 Safe Drinking Water Act (SDWA). Under the SDWA and the 1986 Amendments, EPA sets national limits on contaminant levels in drinking water to ensure that the water is safe for human consumption. These limits are known as Maximum Contaminant Levels (MCLs) and Maximum Residual Disinfectant Levels (MRDLs). For some regulations, EPA establishes treatment techniques in lieu of an MCL to control unacceptable levels of contaminants in water.


2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman Jan 2017

2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain high quality water and encourage or execute activities to improve poor water quality. Monitoring is done on nearly 17,000 miles of flowing rivers and streams, more than 134,000 acres of surface water in lakes and reservoirs, as well as the vast storage of groundwater in Nebraska’s aquifers.


2017 Nebraska Groundwater Quality Monitoring Report Jan 2017

2017 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …


Nebraska Summary: S1141 John Deere 6120r, Nebraska Tractor Test Lab Jan 2017

Nebraska Summary: S1141 John Deere 6120r, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: S1110 John Deere 6130m, Nebraska Tractor Test Lab Jan 2017

Nebraska Summary: S1110 John Deere 6130m, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2189: Kubota M7-151, Nebraska Tractor Test Lab Jan 2017

Test 2189: Kubota M7-151, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2182: Claas Axion 860, Nebraska Tractor Test Lab Jan 2017

Test 2182: Claas Axion 860, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2185: Case Ih Steiger 470 Rowtrac, Nebraska Tractor Test Lab Jan 2017

Test 2185: Case Ih Steiger 470 Rowtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2184: Case Ih Steiger 420 Rowtrac, Nebraska Tractor Test Lab Jan 2017

Test 2184: Case Ih Steiger 420 Rowtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2183: Claas Axion 880, Nebraska Tractor Test Lab Jan 2017

Test 2183: Claas Axion 880, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2181: Claas Axion 840, Nebraska Tractor Test Lab Jan 2017

Test 2181: Claas Axion 840, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2180: Claas Axion 820, Nebraska Tractor Test Lab Jan 2017

Test 2180: Claas Axion 820, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2179: John Deere 7210r, Nebraska Tractor Test Lab Jan 2017

Test 2179: John Deere 7210r, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2178: Kubota M7-171, Nebraska Tractor Test Lab Jan 2017

Test 2178: Kubota M7-171, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2176: Kubota M7-131, Nebraska Tractor Test Lab Jan 2017

Test 2176: Kubota M7-131, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2188: Case Ih Steiger 540 Quadtrac, Nebraska Tractor Test Lab Jan 2017

Test 2188: Case Ih Steiger 540 Quadtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2187: Case Ih Steiger 500 Quadtrac, Nebraska Tractor Test Lab Jan 2017

Test 2187: Case Ih Steiger 500 Quadtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …