Engineering Commons^™

Demonstration Of A Daily High-Resolution (375-M) Alexi Evapotranspiration Product For The Nena Region, Christopher Hain, Martha C. Anderson, Mitch Schull, Christopher M.U. Neale

Daugherty Water for Food Global Institute: Faculty Publications

While the current constellation of geostationary sensors provides near-global coverage (60N to 60S) – it requires merging data from 7 satellites [resolving time differences; view angles; atmospheric correction]. Polar orbiting sensors such as MODIS and VIIRS provide daily global coverage of LST at higher resolutions than GEO sensors but at only two times per day.

Yield Gap Analysis Of Field Crops: Methods And Case Studies, V. O. Sadras, Kenneth Cassman, Patricio Grassini, W. G.M. Bastiaanssen, A. G. Laborte, A. E. Milne, G. Sileshi, P. Steduto

Daugherty Water for Food Global Institute: Faculty Publications

The challenges of global agriculture have been analysed exhaustively and the need has been established for sustainable improvement in agricultural production aimed at food security in a context of increasing pressure on natural resources. Whereas the importance of R&D investment in agriculture is increasingly recognised, better allocation of limited funding is essential to improve food production. In this context, the common and often large gap between actual and attainable yield is a critical target. Realistic solutions are required to close yield gaps in both small and large scale cropping systems worldwide; to make progress in this direction, we need (1) …

Integrating Ecological And Engineering Concepts Of Resilience In Microbial Communities, Hyun-Seob Song, Ryan S. Renslow, Jim K. Fredrickson, Stephen R. Lindemann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Many definitions of resilience have been proffered for natural and engineered ecosystems, but a conceptual consensus on resilience in microbial communities is still lacking. We argue that the disconnect largely results from the wide variance in microbial community complexity, which range from compositionally simple synthetic consortia to complex natural communities, and divergence between the typical practical outcomes emphasized by ecologists and engineers. Viewing microbial communities as elasto-plastic systems that undergo both recoverable and unrecoverable transitions, we argue that this gap between the engineering and ecological definitions of resilience stems from their respective emphases on elastic and plastic deformation, respectively. We …

An Adaptive Photovoltaic Topology To Overcome Shading Effect In Pv Systems, Mohamed Amer Chaaban, Lana El Chaar, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Shading in photovoltaic systems can cause many undesired effects.When shading occurs, the power generated from the PV system is much less than nominal power, increasing the electrical mismatching losses between PV system components. Active research to address this power loss focuses on static and adaptive systems.This paper addresses an adaptive system solution and proposes a new method to adaptively overcome losses due to shading during low radiation conditions. In addition, a statistical analysis for choosing the most feasible and efficient configuration for the system size is presented. The proposed system has been validated under shade conditions in a simulation and …

Influence Of Spatial Variations Of Railroad Track Stiffness And Material Inclusions On Fatigue Life, Celestin Nkundineza

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Railroad transportation is very important for economic growth and effective maintenance is one critical factor for its economic sustainability. The high repetitive forces from a moving railcar induce cyclic stresses that lead to rail bending and potential deterioration due to fatigue crack initiation and propagation. Previous research for prediction of fatigue life has been done under the assumptions of a uniform track bed and a homogeneous rail. However the spatial variation of the track stiffness is expected to increase the maximum stresses in the rail and, therefore, accelerate the fatigue process. The research described in this dissertation is focused on …

Evaluation Of Sixteen Reference Evapotranspiration Methods Under Sahelian Conditions In The Senegal River Valley, Koffi Djaman, Alpha B. Balde, Abdoulaye Sow, Bertrand Muller, Suat Irmak, Mamadou K. N'Diaye, Baboucarr Manneh, Yonnelle D. Moukoumbi, Koichi Futakuchi, Kazuki Saito

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Study region: Reference evapotranspiration (ETo) plays a key role in irrigation sys-tems design, water management under irrigated and rainfed production. Underthe sahelian conditions in the Senegal River Valley that receives less than 300 mmannual rainfall, rice crop water use should be estimated for the sustainability of theresource. Study focus: However the Penman–Monteith (PM) equation is revealed the mostaccurate one; it necessitates several climatic parameters that are not always avail-able mostly in the developing countries. The objective of this study was to evaluatethe performance of 16 ETo equations against the ASCE-PM equation under thesahelian conditions at Ndiaye and Fanaye …

Using Swat To Simulate Crop Yields And Salinity Levels In The North Fork River Basin, Usa, Aaron R. Mittelstet, Daniel E. Storm, Art L. Stoecker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop yields and salinity levels in the North Fork of the Red River (North Fork River) basin, located in southwestern Oklahoma and the Texas Panhandle, were analyzed based on the diverse climate in the region. Saline irrigation water is a major problem in the basin. The Elm Fork Creek flows through salt deposits, making the creek and its receiving stream, the North Fork River, too saline to use for irrigation. This greatly reduces the number of hectares that can be utilized for agricultural crops within the basin. A baseline SWAT model was setup, calibrated and validated to simulate streamflow and …

A Low-Power Compact Nuclear Quadrupole Resonance (Nqr) Based Explosive Detection System, Xinwang Zhang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Abandoned landmines and terrorist bomb attacks are severe issues threatening our society. These issues necessitate the development of prompt and accurate explosive detection systems. The detection mechanisms commonly-used nowadays usually search for explosive containers, which suffer numerous false alarms caused by external detection circumstance changes. Alternatively, explosive substances inside the bombs and landmines can be detected by means of biology, chemistry and physics techniques. Nuclear Quadrupole Resonance (NQR) detection technology has proven to be a highly effective solution for detecting explosives unambiguously.

In this work, a portable NQR-based explosive detection system that employs state-of-the-art semiconductor technologies is presented. This system …

A Game-Theoretic Analysis Of The Nuclear Non-Proliferation Treaty, Peter Revesz

School of Computing: Conference and Workshop Papers

Although nuclear non-proliferation is an almost universal human desire, in practice, the negotiated treaties appear unable to prevent the steady growth of the number of states that have nuclear weapons. We propose a computational model for understanding the complex issues behind nuclear arms negotiations, the motivations of various states to enter a nuclear weapons program and the ways to diffuse crisis situations.

Reply To ‘Co2 Emissions From Crop Residue-Derived Biofuels’, Adam Liska, Haishun Yang, Matthew P. Pelton, Andrew E. Suyker

Adam Liska Papers

The soil organic carbon (SOC) model that we used was parameterized with data from arable land under normal farming conditions in North America, Europe, Africa and Asia, but the equation is insensitive to changes in tillage, soil texture and moisture. The model has reasonable accuracy, however, in predicting changes in SOC, residue remaining and CO₂ emissions from initial SOC, carbon inputs from residue, and daily temperature; the shoot-to-root ratio used in the geospatial simulation was 0.29 (that is, root carbon is 29% of total aboveground carbon), which did not underestimate carbon input to soil (Supplementary Figure 2 in Ref. …

Flax Fibre: Innovation And Change In The Early Neolithic; A Technological And Material Perspective, Susanna Harris

Textile Society of America: Symposium Proceedings

Flax (Linum sp.) was one of the first domestic plants in Neolithic Europe, providing a potential cultivable source of fibres for the first farmers. As the plant provides both oil and fibre, it is a matter of enquiry as to whether the plant was first domesticated for its seeds or stem. Through examining new data collected by the EUROEVOL Project, UCL it is possible to chart the earliest archaeobotanical evidence for flax species in Europe. This provides the basis on which to consider the origin of fibres from the flax plant (linen) as a basis for change and innovation …

Irrigation Demand In A Changing Climate: Using Disaggregate Data To Predict Future Groundwater Use, Calvin R. Shaneyfelt

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The paper estimates an irrigation water demand function using disaggregate climate and well data over a 33 year time period. Aggregating climate information over long periods, like a year, causes a loss of detail on temporal climatic variation, while aggregating climate information over space causes a loss of detail on spatial variation. This analysis uses disaggregate climate variation at a temporospatial level to determine the effects of climate on groundwater use. Results show that increased heat, measured in cooling degree-days, correlates with increased water use, while increased precipitation correlates with decreased water use. However, the effects are generally magnified for …

Determining The Dynamics Of Agricultural Water Use: Cases From Asia And Africa, Lisa-Maria Rebelo, Robyn Johnston, Poolad Karimi, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

Across Africa and Asia, water resources are being affected by a complex mixture of social, economic, and environmental factors. These include climate change and population growth, food prices, oil prices, financial disruptions, and political fluctuations. The need to produce more food will have one of the largest impacts on water and will continue to reshape the patterns of agricultural water use in major food-growing regions. With this increasing demand on water for agriculture, from large-scale irrigation to intensification of rainfed systems, it is becoming increasingly important to ensure that water resources decision-making has access to information that captures the spectrum …

Biofuels From Crop Residue Can Reduce Soil Carbon And Increase Co2 Emissions, Adam J. Liska, Haishun Yang, Maribeth Milner, Steve Goddard, Humberto Blanco-Canqui, Matthew P. Pelton, Xiao X. Fang, Haitao Zhu, Andrew E. Suyker

Adam Liska Papers

Removal of corn residue for biofuels can decrease soil organic carbon(SOC) and increase CO₂ emissions because residue C in biofuels is oxidized to CO₂ at a faster rate than when added to soil. Net CO2 emissions from residue removal are not adequately characterized in biofuel life cycle assessment (LCA). Here we used a model to estimate CO₂ emissions from corn residue removal across the US Corn Belt at 580 million geospatial cells. To test the SOC model, we compared estimated daily CO₂ emissions from corn residue and soil with CO₂ emissions measured using eddy covariance, …

Providing Flexible File-Level Data Filtering For Big Data Analytics, Lei Xu, Ziling Huang, Hong Jiang, Lei Tian, David Swanson

School of Computing: Technical Reports

The enormous amount of big data datasets impose the needs for effective data filtering technique to accelerate the analytics process. We propose a Versatile Searchable File System, VSFS, which provides a transparent, flexible and near real-time file-level data filtering service by searching files directly through the file system. Therefore, big data analytics applications can transparently utilize this filtering service without application modifications. A versatile index scheme is designed to adapt to the exploratory and ad-hoc nature of the big data analytics activities. Moreover, VSFS uses a RAM-based distributed architecture to perform file indexing. The evaluations driven by three real-world analytics …

Afrontar El Cambio: Cuidar Del Agua, De La Agricultura Y De La Seguridad Alimentaria En Una Era De Incertidumbre Climática, Peter G. Mccornick, Vladimir Smakhtin, Luna Bharati, Robyn Johnston, Matthew Mccartney, Fraser Sugden, Floriane Clement, Beverly Mcintyre

Daugherty Water for Food Global Institute: Faculty Publications

En 1950, la población mundial era apenas superior a los 2500 millones de habitantes. En 2013, ronda los 7 mil millones. Aunque el crecimiento de la población se está ralentizando, se estima que en 2050 se alcanzarán los 9600 millones de habitantes. El aumento de la población será mayor en los países en desarrollo, donde los alimentos a menudo escasean, y la tierra y el agua están sometidas a presión. Para alimentar a la población mundial en 2050, tendrán que producirse más alimentos sin que haya un aumento significativo del terreno de cultivo y contando con un caudal menor de …

Fluoride Exposure From Groundwater As Reflected By Urinary Fluoride And Children’S Dental Fluorosis In The Main Ethiopian Rift Valley, Tewodros Rango, Avner Vengosh, Marc Jeuland, Redda Tekle-Haimanot, Erika Weinthal, Julia Kravchenko, Christopher Paul, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are lifelong residents of 33 rural communities in which groundwater concentrations of F⁻ cover a wide range. A subset of 156 children was selected for urinary F⁻ measurements. Our results showed that the mean F⁻ concentrations in groundwater were 8.5 ± 4.1 mg/L (range: 1.1–18 mg/L), while those in urine …

The Effect Of Non-Fluoride Factors On Risk Of Dental Fluorosis: Evidence From Rural Populations Of The Main Ethiopian Rift, Julia Kravchenko, Tewodros Rango, Igor Akushevich, Behailu Atlaw, Peter G. Mccornick, R. Brittany Merola, Christopher Paul, Erika Weinthal, Courtney Harrison, Avner Vengosh, Marc Jeuland

Daugherty Water for Food Global Institute: Faculty Publications

Elevated level of fluoride (F⁻) in drinking water is a well-recognized risk factor of dental fluorosis (DF). While considering optimization of region-specific standards for F⁻, it is reasonable, however, to consider how local diet, water sourcing practices, and non-F⁻ elements in water may be related to health outcomes. In this study, we hypothesized that non-F⁻ elements in groundwater and lifestyle and demographic characteristics may be independent predictors or modifiers of the effects of F⁻ on teeth. Dental examinations were conducted among 1094 inhabitants from 399 randomly selected households of 20 rural communities of …

Fluoride Exposure From Groundwater As Reflected By Urinary Fluoride And Children’S Dental Fluorosis In The Main Ethiopian Rift Valley, Tewodros Rango, Avner Vengosh, Marc Jeuland, Redda Tekle-Haimanot, Erika Weinthal, Julia Kravchenko, Christopher Paul, Paul Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are lifelong residents of 33 rural communities in which …

On Target For People And Planet: Setting And Achieving Water-Related Sustainable Development Goals, Julie Van Der Bliek, Peter G. Mccornick, James Clarke

Daugherty Water for Food Global Institute: Faculty Publications

Our specific focus in this book is on securing water for sustainable food production. This links to sustainable water resources management, delivering on the water supply and sanitation requirements and provisioning water for energy and the urban sector. A specific intent is to ensure that the realities in low- and middle-income countries in Africa and Asia are recognized and to provide practical pathways to change that fit these realities and the aspirations of those countries. This will help to prepare for the next step in the SDG [sustainable development goals] process: devolving the SDGs to the national level. It will …

Co-Occurrence Of The Cyanotoxins Bmaa, Daba And Anatoxin-A In Nebraska Reservoirs, Fish, And Aquatic Plants, Maitham Ahmed Al-Sammak, Kyle D. Hoagland, David A. Cassada, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins β-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and animal health. Biomagnification, though not well understood in aquatic systems, is potentially relevant to both human and animal health effects. Because little is known regarding their presence in fresh water, we investigated the occurrence and potential for bioaccumulation of cyanotoxins …

Seed Tape Effects On Corn Emergence Under Greenhouse Conditions, Ramarao Venkatesh, Peter R. Thomison, Colette K. Gabriel, Mark A. Bennett, Elaine M. Grassbaugh, Matthew D. Kleinhenz, Scott A. Shearer, Santosh Pitla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Seed tape has recently received attention as an alternative planting system for smallholder farmers in underdeveloped regions of South America, Africa, China, and India (Mateus, 2014). Seed companies are also developing seed-tape planting systems for germplasm evaluations (Deppermann et al., 2013). Although seed tape has been promoted as a method for ensuring uniform seed spacing and plant density of small-seeded flowers, herbs, and vegetables (Chancellor, 1969), little or no information is available on the use of seed tape for larger-seeded row crops and its effect on crop emergence. The objective of this study was to compare the emergence of corn …

The Biophysical Link Between Climate, Water, And Vegetation In Bioenergy Agro-Ecosystems, Justin E. Bagley, Sarah C. Davis, Matei Georgesu, Mir Zaman Hussain, Jesse Miller, Stephen W. Nesbitt, Andy Vanloocke, Carl J. Bernacchi

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes …

Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO₂ emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO₂ flux data from a 9-year field …

Design Of Experimental Methods To Test The Performance Of Pads And Helmets Under Blast Loading Conditions, Kurtis Palu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Improvised explosive devices (IEDs) have become a primary weapon in conflicts against US and allied forces. Improvements in body armor and medicine have increased the survivability of such events. These factors have caused an increase in traumatic brain injury (TBI) and mild traumatic brain injury (mTBI) induced by primary blast waves. Injury mechanisms caused from primary blast waves are not clearly understood or defined. How primary blast waves interact with materials or between narrow gaps found between helmet pads is not known. Two novel test fixtures were developed to provide a basic understanding of these two issues.

The first fixture …

Department Of Biological Systems Engineering Newsletter, Volume 7, Number 2, April 2013

BSE Department Magazine

No abstract provided.

Tackling Change: Future-Proofing Water, Agriculture, And Food Security In An Era Of Climate Uncertainty, Peter G. Mccornick, Vladimir Smakhtin, Luna Bharati, Robyn Johnston, Matthew Mccartney, Fraser Sugden, Floriane Clement, Beverly Mcintyre

Daugherty Water for Food Global Institute: Faculty Publications

In 1950 the global population was just over 2.5 billion. Now, in 2013, it is around 7 billion. Although population growth is slowing, the world is projected to have around 9.6 billion inhabitants by 2050. Most of the population increase will be in developing countries where food is often scarce, and land and water are under pressure. To feed the global population in 2050 the world will have to produce more food without significantly expanding the area of cultivated land and, because of competition between a greater number of water users, with less freshwater. On top of land and water …

Maintaining The Master International Frequency Register, Frans G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

The present paper is the written elaboration of a presentation held under the same title at the workshop “International Regulations of Space Communications” held in Luxembourg on 24 and 25 May 2012. Consequently, the topic of this paper, the maintenance of the Master International Frequency Register as a key tool for allowing satellite communications to be a viable international sector of space activities, is viewed through the looking glass of the session title, “WRC-12 from the Perspective of International Telecommunications Law.”

In other words, it does not purport to deal with the actual details of maintaining the Register …

Vibration Energy Harvesting For Wireless Underground Sensor Networks, Salman Kahrobaee, Mehmet C. Vuran

Department of Electrical and Computer Engineering: Faculty Publications

Recent developments in wireless underground communication have enabled the realization of underground sensor network applications. To this end, it is desirable to provide a sustainable operation for wireless underground sensor networks (WUSNs) with extended lifetimes as maintenance is significantly costly. One promising method towards sustainable operation is to harvest energy underground based on the vibration sources in the environment. However, to the best of our knowledge, underground vibration energy harvesting has not been investigated before. In this paper, the feasibility of vibration energy harvesting for WUSNs is investigated. First, an analytical framework is developed to model the maximum harvestable power …

Proceedings Of The Nebraska Academy Of Sciences: Anthropology

Nebraska Academy of Sciences: Programs and Proceedings

Presentations

A Marxist Approach to US Historical Archaeology: A Review and Summary of the History and Application of Marxism on the Field of Historical Archaeology in the US

John Collier, Anthropology, and the Indian New Deal

Colonoware and Culture: The Changing Interpretation of 17th Century Ceramic Traditions in the South Eastern United States

Creole Cottages and Garden Estates: Space and Purpose in Early New Orleans

Quality Control for In-field Photography: Digital Curationa and Non-collections of Artifacts

Assesing Lithics through Color Metrics

Refitting of Stone Artifacts Using Colorimetric Analysis

The Restroer of the Republic: An Analysis of Augustus’s Social, Moral, and …