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Full-Text Articles in Engineering

A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam Dec 2020

A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam

Faculty Publications

Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the …


Literature Review: Global Neonicotinoid Insecticide Occurrence In Aquatic Environments, Josephus F. Borsuah, Tiffany L. Messer, Daniel D. Snow, Steve D. Comfort, Aaron R. Mittelstet Dec 2020

Literature Review: Global Neonicotinoid Insecticide Occurrence In Aquatic Environments, Josephus F. Borsuah, Tiffany L. Messer, Daniel D. Snow, Steve D. Comfort, Aaron R. Mittelstet

Biosystems and Agricultural Engineering Faculty Publications

Neonicotinoids have been the most commonly used insecticides since the early 1990s. Despite their efficacy in improving crop protection and management, these agrochemicals have gained recent attention for their negative impacts on non-target species such as honeybees and aquatic invertebrates. In recent years, neonicotinoids have been detected in rivers and streams across the world. Determining and predicting the exposure potential of neonicotinoids in surface water requires a thorough understanding of their fate and transport mechanisms. Therefore, our objective was to provide a comprehensive review of neonicotinoids with a focus on their fate and transport mechanisms to and within surface waters …


Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and …


Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza Aug 2020

Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza

Faculty Publications

The electromagnetic characteristics of the soil are discussed in this chapter. The characteristics of porous bedrock, soil medium, and impacts of rain attenuations are also presented. The models of dielectric soil properties are studied with a rigorous focus on the constitutive parameters of subsurface soil medium. Moreover, the permittivity and wavenumber in soil are explained. In addition, the frequency-dependent dielectric properties such as dispersion in soil, absorption characteristic, and penetration depth versus frequency are reviewed. Furthermore, the effective permittivity of soil–water mixture for through-the soil-propagation mechanism is analyzed thoroughly.


Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza Aug 2020

Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza

Faculty Publications

This chapter presents a framework for adaptive beamforming in underground communication. The wireless propagation is thoroughly analyzed to develop a model using the soil moisture as an input parameter to provide feedback mechanism while enhancing the system performance. The working of array element in the soil is analyzed. Moreover, the effect of soil texture and soil moisture on the resonant frequency and return loss is studied in detail. The wave refraction from the soil–air interface highly degrades the performance of the system. Furthermore, to beam steering is done to achieve high gain for lateral component improving the UG communication. The …


Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza

Faculty Publications

Antenna is a major design component of Internet of Underground Things (IOUT) communication system. The use of antenna, in IOUT, differs from traditional communication in that it is buried in the soil. Therefore, one of the main challenges, in IOUT applications, is to establish a reliable communication. To that end, there is a need of designing an underground-specific antenna. Three major factors that can impact the performance of a buried antenna are: (1) effect of high soil permittivity changes the wavelength of EM waves, (2) variations in soil moisture with time affecting the permittivity of the soil, and (3) difference …


Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza Aug 2020

Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza

Faculty Publications

The soil moisture and permittivity estimation is vital for the success of the variable rate approaches in the field of the decision agriculture. In this chapter, the development of a novel permittivity estimation and soil moisture sensing approach is presented. The empirical setup and experimental methodology for the power delay measurements used in model are introduced. Moreover, the performance analysis is explained that includes the model validation and error analysis. The transfer functions are reported as well for soil moisture and permittivity estimation. Furthermore, the potential applications of the developed approach in different disciplines are also examined.


Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza Aug 2020

Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza

Faculty Publications

The latest developments in Internet of Underground Things are covered in this chapter. First, the IOUT Architecture is discussed followed by the explanation of the challenges being faced in this paradigm. Moreover, a comprehensive coverage of the different IOUT components is presented that includes communications, sensing, and system integration with the cloud. An in-depth coverage of the applications of the IOUT in various disciplines is also surveyed. These applications include areas such as decision agriculture, pipeline monitoring, border control, and oil wells.


Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, novel subsurface soil sensing approaches are presented for monitoring and real-time decision support system applications. The methods, materials, and operational feasibility aspects of soil sensors are explored. The soil sensing techniques covered in this chapter include aerial sensing, in-situ, proximal sensing, and remote sensing. The underlying mechanism used for sensing is also examined as well. The sensor selection and calibration techniques are described in detail. The chapter concludes with discussion of soil sensing challenges.


Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the important application of autonomous irrigation management in the field decision agriculture is discussed. The different types of sensor-guided irrigation systems are presented that includes center pivot systems and drip irrigation systems. Their sensing and actuator components are with detailed focus on real-time decision-making and integration to the cloud. This chapter also presents irrigation control systems which takes, as an input, soil moisture and temperature from IOUT and weather data from Internet and communicate with center pivot based irrigation systems. Moreover, the system architecture is explored where development of the nodes including sensing and actuators is presented. …


Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the variable rate applications (VRA) are presented for the field of decision agriculture. The characteristics of VRA control systems are described along with control hardware. Different types of VRA systems are discussed (e.g., liquid VRA systems and dry VRA systems). A case study is also explored in this regard. Moreover, recent advances and future trends are also outlined. Accordingly, a sustainable variable-rate irrigation scheduling is studied where different hardware and software component of the cyber-physical system are considered. Finally, chapter is concluded with a novel sensor deployment methodology.


Photovoltaic Systems On Dairy Farms: Financial And Renewable Multi-Objective Optimization (Farmoo) Analysis, Michael Breen, J. Upton, Michael D. Murphy Aug 2020

Photovoltaic Systems On Dairy Farms: Financial And Renewable Multi-Objective Optimization (Farmoo) Analysis, Michael Breen, J. Upton, Michael D. Murphy

Publications

No abstract provided.


On-Farm Research And Student Engagement To Assess And Promote The Use Of Organic Amendments To Improve Agricultural Soil Health And Resilience Of Crop Production Systems In Nebraska, Agustin Jose Olivo Jul 2020

On-Farm Research And Student Engagement To Assess And Promote The Use Of Organic Amendments To Improve Agricultural Soil Health And Resilience Of Crop Production Systems In Nebraska, Agustin Jose Olivo

Department of Biological Systems Engineering: Dissertations and Theses

In nearly every production environment, there are opportunities to capture profits if waste streams can be further processed or enhanced to create “value added” products. On-farm research studies were initiated in 2019 at four locations across Nebraska to assess the impacts of livestock manure, cedar mulch from forestry management and coal char from sugar beet processing, on agricultural cropland. Study treatments included beef cattle manure (CM), beef cattle slurry (CS), coal char (CC), woody biomass (WB) CM+WB, CS+WB, CM+CC and control (CON; no organic amendment). Soil properties and corn yield were evaluated after a single growing season. Results indicate that …


Restoring Lake Urmia: Moving Beyond A Uniform Lake Level (2-Page Summary), Somayeh Sima, Dory Rosenberg, Wayne A. Wurtsbaugh, Sarah E. Null, Karin M. Kettenring Jul 2020

Restoring Lake Urmia: Moving Beyond A Uniform Lake Level (2-Page Summary), Somayeh Sima, Dory Rosenberg, Wayne A. Wurtsbaugh, Sarah E. Null, Karin M. Kettenring

Watershed Sciences Faculty Publications

More than 5 million people live near Lake Urmia in northwestern Iran, one of the world's largest hypersaline lakes. Over the past two decades, the lake has lost 95% of its volume, lake level has dropped more than 7 m, and lake restoration has gained widespread interest. The government seeks a uniform "ecological" target lake level of 1274.1 m above sea level to lower salinity below 240 gL-1 and recover brine shrimp (Artemia spp.) and flamingos (Phoenicopterus roseus).

We have synthesized over 40 years of available data, defined 8 ecosystem services for human health, water quality, ecology, recreation, and …


Implications Of Soil And Canopy Temperature Uncertainty In The Estimation Of Surface Energy Fluxes Using Tseb2t And High-Resolution Imagery In Commercial Vineyards, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Luis Sanchez, Nick Dokoozlian May 2020

Implications Of Soil And Canopy Temperature Uncertainty In The Estimation Of Surface Energy Fluxes Using Tseb2t And High-Resolution Imagery In Commercial Vineyards, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Luis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Estimation of surface energy fluxes using thermal remote sensing–based energy balance models (e.g., TSEB2T) involves the use of local micrometeorological input data of air temperature, wind speed, and incoming solar radiation, as well as vegetation cover and accurate land surface temperature (LST). The physically based Two-source Energy Balance with a Dual Temperature (TSEB2T) model separates soil and canopy temperature (Ts and Tc) to estimate surface energy fluxes including Rn, H, LE, and G. The estimation of Ts and Tc components for the TSEB2T model relies on the linear relationship between the composite land surface temperature and a vegetation index, namely …


To What Extent Does The Eddy Covariance Footprint Cutoff Influence The Estimation Of Surface Energy Fluxes Using Two Source Energy Balance Model And High-Resolution Imagery In Commercial Vineyards?, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Louis Sanchez, Nick Dokoozlian May 2020

To What Extent Does The Eddy Covariance Footprint Cutoff Influence The Estimation Of Surface Energy Fluxes Using Two Source Energy Balance Model And High-Resolution Imagery In Commercial Vineyards?, Ayman Nassar, Alfonso F. Torres-Rua, William Kustas, Héctor Nieto, Mac Mckee, Lawrence Hipps, Joseph Alfieri, John H. Prueger, Maria Mar Alsina, Lynn Mckee, Calvin Coopmans, Louis Sanchez, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Validation of surface energy fluxes from remote sensing sources is performed using instantaneous field measurements obtained from eddy covariance (EC) instrumentation. An eddy covariance measurement is characterized by a footprint function / weighted area function that describes the mathematical relationship between the spatial distribution of surface flux sources and their corresponding magnitude. The orientation and size of each flux footprint / source area depends on the micro-meteorological conditions at the site as measured by the EC towers, including turbulence fluxes, friction velocity (ustar), and wind speed, all of which influence the dimensions and orientation of the footprint. The …


Estimation Of Evapotranspiration And Energy Fluxes Using A Deep-Learning-Based High-Resolution Emissivity Model And The Two-Source Energy Balance Model With Suas Information, Alfonso F. Torres-Rua, Andres Ticlavilca, Mahyar Aboutalebi, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Joseph Alfieri, Lawrence Hipps, Lynn Mckee, William Kustas, Calvin Coopmans, Nick Dokoozlian May 2020

Estimation Of Evapotranspiration And Energy Fluxes Using A Deep-Learning-Based High-Resolution Emissivity Model And The Two-Source Energy Balance Model With Suas Information, Alfonso F. Torres-Rua, Andres Ticlavilca, Mahyar Aboutalebi, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Joseph Alfieri, Lawrence Hipps, Lynn Mckee, William Kustas, Calvin Coopmans, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Surface temperature is necessary for the estimation of energy fluxes and evapotranspiration from satellites and airborne data sources. For example, the Two-Source Energy Balance (TSEB) model uses thermal information to quantify canopy and soil temperatures as well as their respective energy balance components. While surface (also called kinematic) temperature is desirable for energy balance analysis, obtaining this temperature is not straightforward due to a lack of spatially estimated narrowband (sensor-specific) and broadband emissivities of vegetation and soil, further complicated by spectral characteristics of the UAV thermal camera. This study presents an effort to spatially model narrowband and broadband emissivities for …


Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray Feb 2020

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …