Environmental Engineering Commons^™

161. The Potential Role Of Extensor Muscle Fatigue In The Onset Of Intervertebral Disc Degeneration: A Novel In Vivo Model, Mary Beth M. Grabowsky, Nicholas A. Pallota, Matthew W. Connelly, Brett Van Etten, Rebecca A. Wachs, Max Alley, Joseph C. Glennon, Andrew H. Dubin, John W. German, Richard L. Uhl, Eric H. Ledet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

BACKGROUND CONTEXT: Occupation is strongly correlated to low back pain (LBP). Specific occupational activities associated with low back pain include poor posture, whole body vibration, and repetitive lifting. These activities have a common link: they result in fatigue of the primary spinal extensor musculature. This fatigue may lead to increased intervertebral loading - a stimulus for disc degeneration. If true, this association could provide a vital connection between detrimental physical activities and LBP. However, the link between muscle fatigue and increased load across the disc space has never been quantified in vivo.

PURPOSE: The purpose of this study was to …

Nebraska Agricultural Water Management Demonstration Network (Nawmdn): Integrating Research And Extension/Outreach, Suat Irmak, Jennifer M. Rees, Gary L. Zoubek, Brandy S. Van Dewalle, William R. Rathje, Rodney Debuhr, Dan Leininger, Darrel D. Siekman, James W. Schneider, Andrew P. Christiansen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Maximizing the net benefits of irrigated plant production through appropriately designed agricultural water management programs is of growing importance in Nebraska, and other western and Midwestern states, because many areas are involved in management and policy changes to conserve irrigation water. In Nebraska, farmers are being challenged to practice conservation methods and use water resources more efficiently while meeting plant water requirements and maintaining high yields. Another challenge Nebraska experiences in it's approximately 3.5‐million‐ha irrigated lands is limited adoption of newer technologies/tools to help farmers better manage irrigation, conserve water and energy, and increase plant water use efficiency. In 2005, …

On The Dynamics Of Canopy Resistance: Generalized Linear Estimation And Relationships With Primary Micrometeorological Variables, Suat Irmak, Denis Mutiibwa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The 1‐D and single layer combination‐based energy balance Penman‐Monteith (PM) model has limitations in practical application due to the lack of canopy resistance (r_c) data for different vegetation surfaces. r_c could be estimated by inversion of the PM model if the actual evapotranspiration (E_Ta) rate is known, but this approach has its own set of issues. Instead, an empirical method of estimating r_c is suggested in this study. We investigated the relationships between primary micrometeorological parameters and rc and developed seven models to estimate r_c for a nonstressed maize canopy on an hourly …

Nutrient And Bacterial Transport In Runoff From Soil And Pond Ash Amended Feedlot Surfaces, John E. Gilley, Jason R. Vogel, Elaine D. Berry, Roger Eigenberg, David B. Marx, Brian L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The addition of pond ash (fly ash that has been placed in evaporative ponds and subsequently dewatered) to feedlot surfaces provides a healthier environment for livestock and economic advantages for the feedlot operator. However, the water quality effects of pond ash amended surfaces are not well understood. The objectives of this field investigation were to: (1) compare feedlot soil properties, and nutrient and bacterial transport in runoff, from pond ash amended surfaces and soil surfaces; (2) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and …

Investigation Of The Geotechnical Properties Of Municipal Solid Waste As A Function Of Placement Conditions, Wilson W. Wong

Master's Theses

An investigation of the variability of engineering properties of municipal solid waste as a function of placement conditions was conducted. Limited data have been reported for the engineering properties of municipal solid waste (MSW) as a function of placement conditions. Wastes have high variability of engineering properties due to heterogeneity in composition and component size; influence from time based effects; and presence of compressible solids. Control of moisture content of MSW at the time of waste placement provides opportunity for increased capacity at a given landfill site due to higher compacted unit weight as well as for control of other …

Preserving Assets In At-Risk Municipalities: Financial Strategies For Climate Change Adaptation, New England Environmental Finance Center

Climate Change

A large share of America's population, businesses and economic activity now occurs in coastal areas. At the same time, during this century many coastal communities are likely to be severely impacted by sea level rise and increased storm surge and tidal flooding.

“What to do” about this vulnerability is the subject of this brief. It is intended to help municipalities identify courses of action and steps they might take toward increasing their resilience, especially regarding financial resources that will need to be allocated toward the various strategies identified.

Magnitude And Trends Of Reference Evapotranspiration Rates In South Central Nebraska: Daily, Monthly, Growing Season Total, And Annual Total, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reference evapotranspiration (ET_ref ) is used to determine the actual water use (ET_a) rate for various crops and is one of the key variables that needs to be determined accurately for effective irrigation management. This extension circular provides information on the magnitude and temporal distribution of daily, monthly, annual, and growing season alfalfa-reference evapotranspiration (ET_ref)) in south central Nebraska. It also discusses why long-term average ET_ref values may not represent non-average years or be accurate enough for irrigation management.

The most common way to calculate actual crop water use (ET_a) for a …

Integration Of An Extended Octagonal Ring Transducer And Soil Coulterometer For Identifying Soil Compaction, Santosh Pitla, L. G. Wells, S. A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The soil coulterometer is an “on‐the‐go” electro‐mechanical system which collects impedance force data at multiple depths using an oscillating coulter. During the initial testing (summer 2006), only vertical soil impedance force data was collected using a pressure sensor. To improve the performance of the coulterometer, an extended octagonal ring transducer was integrated into the system to collect both the horizontal and vertical impedance forces given by the soil. In the summer of 2007, data was collected using the revised sensor from a typical central Kentucky field setting in a 0.8‐ha (2‐acre) plot. Four passes were made with the coulterometer. Seventy …

Special Issue On Evapotranspiration Measurement And Modeling, Samuel Ortega-Farias, Suat Irmak, R. H. Cuenca

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability for irrigation throughout the world has been reduced in recent years due to a combination of frequent droughts and competition for water resources among agricultural, industrial, and urban users. In addition, some major agricultural areas face moderate to significant reductions of rainfall, or changes in timing of stream flow due to changes in timing of snowmelt, as a result of global climate change. Under such conditions, sophisticated irrigation water management will be required to optimize water use efficiency and maintain sufficient levels of crop productivity and quality. A key factor to achieve these targets is the estimation of …

Estimating Percent Residue Cover Using The Line-Transect Method, David P. Shelton, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Leaving crop residue on the soil surface is one of the easiest and most cost-effective methods of reducing soil erosion. Research in Nebraska and other midwestern states has shown that leaving as little as 20 percent of the soil surface covered with crop residue can reduce soil erosion by one-half of what it would be from residue-free conditions. Greater amounts of residue cover will further reduce erosion. Many Conservation Plans specify crop residue management or residue left on the soil surface as the primary erosion control method. Generally, the amount of cover required after planting ranges from 30 percent to …

Impact Of Microclimatic Data Measured Above Maize And Grass Canopies On Penman‐Monteith Reference Evapotranspiration Calculations, Suat Irmak, Lameck O. Odhiambo

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Estimation of reference evapotranspiration (ET_ref) using measured microclimatic data and the Penman‐Monteith (PM) method provides a powerful means of quantifying actual plant evapotranspiration (ET_a) needed for use in various disciplines. When applying the PM method to estimate ET_ref, it is desirable to measure the required microclimatic data over a reference grass or alfalfa surface rather than above non‐reference surfaces. However, in reality, establishing and maintaining a reference surface for long periods of time is a difficult task. Other surface energy balance systems, such as the Bowen ratio energy balance system (BREBS), eddy covariance system, …

Special Issue On Evapotranspiration Measurement And Modeling, Samuel Ortega-Farias, Suat Irmak, R. H. Cuenca

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability for irrigation throughout the world has been reduced in recent years due to a combination of frequent droughts and competition for water resources among agricultural, industrial, and urban users. In addition, some major agricultural areas face moderate to significant reductions of rainfall, or changes in timing of stream flow due to changes in timing of snowmelt, as a result of global climate change. Under such conditions, sophisticated irrigation water management will be required to optimize water use efficiency and maintain sufficient levels of crop productivity and quality. A key factor to achieve these targets is the estimation of …

Regional Co2 And Latent Heat Surface Fluxes In The Southern Great Plains: Measurements, Modeling, And Scaling, W. J. Riley, Sebastien C. Biraud, Margaret S. Torn, Marc L. Fischer, David P. Billesbach, Joe A. Berry

Department of Agricultural and Biological Systems Engineering: Faculty Publications

[1] Characterizing net ecosystem exchanges (NEE) of CO2 and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface …

Interpreting Surface-Wave Data For A Site With Shallow Bedrock, Daniel W. Casto, Barbara Luke, Carlos Calderon-Macias, Ronald Kaufmann

Civil and Environmental Engineering and Construction Faculty Research

The inversion of dispersive Rayleigh-wave data has been shown to be successful in providing reliable estimated shear-wave velocities within unconsolidated materials in the near surface. However, in a case where the multi-channel analysis of surface waves method was applied to a site consisting of clay residuum overlying basalt bedrock, inversion for the fundamental-mode Rayleigh wave resulted in shear-wave velocities within the rock that are less than half of expected values. Forward modeling reveals that the fundamental-mode dispersion curve is hardly sensitive to bedrock velocity perturbations over a practical range of wavelengths, leading to poorly constrained solutions. Standard surface-wave methods can …

Development Of A Problem-Based Learning (Pbl) And Cooperative Learning (Cl) Transportation Engineering Course For Undergraduate Students, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

This study reports the findings of a project that was done during the implementation of a problem-based learning (PBL) and cooperative learning (CL) elements into an undergraduate transportation engineering course. The study procedure used the student course evaluations, including a survey questionnaire, and university-wide standardized student evaluations. Additionally, student homework, tests, and exam grades were used as part of the evaluation process. Two methods of teaching formats were evaluated: the traditional teaching method of lecturing and using end-of-chapter book questions for homework assignments and the new currently used teaching method of student field data collection, preparation of a lab report …

Facilitating Use Of The Odor Footprint Tool By Nebraska Pork Producers, Rick R. Stowell

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this project was to make Odor Footprint Tool (OFT) resources readily usable by pork producers and their technical advisors as a planning and screening tool when siting swine facilities. Detailed odor footprints for five specified sizes of swine facilities were developed for twenty-four locations throughout Nebraska: six regional sites and three “localized” sites within each region. Each odor footprint shows the predicted odor annoyance-free frequency as a function of the distance from the facility. Footprints developed using localized weather data differed only slightly from footprints produced using weather data from a regional site when the general topography …

Implementing Mass Nutrient Balance Procedures On Swine Production Facilities, Richard Koelsch, Alan Sutton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Whole Farm Nutrient Balance (WFNB) approaches have been used to provide a measure of environmental performance (Aarts et al., 1992; Lanyon and Beegle, 1993; Klausner, 1995). Whole farm balance concepts are used as part of the Netherlands Mineral Accounting System public policy that includes compulsory mineral input and output reports from livestock farms and levies for excess imbalances (Jongbloed and Lenis, 1998). Procedures for measuring WFNB will be followed in measurements made on commercial swine facilities for 2006 and 2007. The conclusions developed based upon data from 13 for 2006 include:

• On average, the participating swine producers import 1.5 units …

System And Method For Analyzing Material Properties Using Hyperspectral Imaging, Jeyamkondan Subbiah, Chris Richard Calkins, Ashok Samal

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Systems and methods are provided for analyzing material properties of an object using hyperspectral imaging. An exemplary method includes obtaining a hyperspectral image of an object; analyzing the hyperspectral image according to an algorithm; and correlating data obtained from the analysis with material properties of the object.

Lipid Productivity Of Algae Grown On Dairy Wastewater As A Possible Feedstock For Biodiesel, Ian C. Woertz

Master's Theses

The objective of this thesis is to develop a biological wastewater treatment system that utilizes algal growth to simultaneously create renewable energy in the form of biodiesel and digester biogas, remove polluting nutrients, and abate greenhouse gases. Research under the Department of Energy Aquatic Species Program during 1978-1996 concluded that cultivating algae for biofuels was cost prohibitive at that time and that an integrated approach should be studied that combined wastewater treatment with algal biofuel production. Nutrient removal, in particular nitrogen and phosphorus, from wastewater is a growing regulatory need and the use of algae cultivation could create a unique …

Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The knowledge of drivers on who has the right-of-way between the one on mainline lanes of a freeway and the one entering the freeway through on-ramp junction lane was evaluated. In addition, drivers’ opinions on how to make the on-ramp junctions safer were collected. A survey instrument with 21 items requesting drivers’ information in regard with demographics, freeway driving experience, knowledge of right-of-way and merging practices was used for data collection. The results show that crashes are relatively rare events and for some reasons, most of them never happen but result into near misses, which can not be reported and …

Laying The Groundwork For Odor Control And Setback Estimation In Nebraska, Rick R. Stowell

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this field research study was to validate use of the Odor Footprint Tool (OFT) with livestock building sources in rural communities. The primary objective was to evaluate the accuracy of predictions of annoyance potential (as projected by odor concentration output data from AERMOD^® - the OFT's underlying dispersion model) when compared to measures of annoyance potential made in the field. Odor assessors were trained to monitor odors around a 4,800-head finishing site in eastern Nebraska. During the summer of 2005, mobile odor assessors monitored odor levels at downwind locations. During the spring and summer of 2006, …

Spatiotemporal Variations In Growing Season Exchanges Of Co2, H2o, And Sensible Heat In Agricultural Fields Of The Southern Great Plains, Marc L. Fischer, Dave P. Billesbach, Joseph A. Berry, William J. Riley, Margaret S. Torn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate, vegetation cover, and management create finescale heterogeneity in unirrigated agricultural regions, with important but not well quantified consequences for spatial and temporal variations in surface CO2, water, and heat fluxes. Eddy covariance fluxes were measured in seven agricultural fields—comprising winter wheat, pasture, and sorghum—in the U.S. Southern Great Plains (SGP) during the 2001–03 growing seasons. Land cover was the dominant source of variation in surface fluxes, with 50%–100% differences between fields planted in winter–spring versus fields planted in summer. Interannual variation was driven mainly by precipitation, which varied more than twofold between years. Peak aboveground biomass and growing season …

Subsurface Characterization Using Textural Features Extracted From Gpr Data, R. S. Freeland, Lameck O. Odhiambo

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Subsurface conditions can be non-intrusively mapped by observing and grouping patterns of similarity within ground-penetrating radar (GPR) profiles. We have observed that the intricate and often visually indiscernible textural variability found within a complex GPR image possesses important parameters that help delineate regions of similar subsurface characteristics. In this study, we therefore examined the feasibility of using textural features extracted from GPR data to automate subsurface characterization. The textural features were matched to a “fingerprint” database of previous subsurface classifications of GPR textural features and the corresponding physical probings of subsurface conditions. Four textural features (energy, contrast, entropy, and homogeneity) …

Analysis Of An Ion‐Selective Electrode Based Methodology For Integrated On‐The‐Go Mapping Of Soil Ph, Potassium, And Nitrate Contents, B. Sethuramasamyraja, V. I. Adamchuk, D. B. Marx, A. Dobermann, G. E. Meyer, D. D. Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Knowledge of the spatial variation of soil attributes is critical for precision agriculture. On‐the‐go soil sensors have been able to provide relatively high mapping density while assessing this variation. A new ion‐selective electrode (ISE) based approach was developed and tested for simultaneous mapping of soil pH, residual nitrate (NO3 -), and soluble potassium (K+) contents. In this article, results of laboratory experiments investigating the effects of key measurement factors on ISE performance are presented. In addition to four different soils, these factors included: soil/water ratio (SWR), quality of water used for electrode rinsing (QWR) and for …

Risk Of Colon Cancer In Hereditary Non-Polyposis Colorectal Cancer Patients As Predicted By Fuzzy Modeling: Influence Of Smoking, Rhonda M. Brand, David D. Jones, Henry T. Lynch, Randall E. Brand, Patrice Watson, Ramesh Ashwathnayaran, Hemant K. Roy

Department of Agricultural and Biological Systems Engineering: Faculty Publications

AIM: To investigate whether a fuzzy logic model could predict colorectal cancer (CRC) risk engendered by smoking in hereditary non-polyposis colorectal cancer (HNPCC) patients.

METHODS: Three hundred and forty HNPCC mismatch repair (MMR) mutation carriers from the Creighton University Hereditary Cancer Institute Registry were selected for modeling. Age-dependent curves were generated to elucidate the joint effects between gene mutation (hMLH1 or hMSH2), gender, and smoking status on the probability of developing CRC.

RESULTS: Smoking significantly increased CRC risk in male hMSH2 mutation carriers (P < 0.05). hMLH1 mutations augmented CRC risk relative to hMSH2 mutation carriers for males (P < 0.05). Males had a significantly higher risk of CRC than females for hMLH1 non smokers (P < 0.05), hMLH1 smokers (P < 0.1) and hMSH2 smokers (P < 0.1). Smoking promoted CRC in a dose-dependent manner in hMSH2 in males (P < 0.05). Females with hMSH2 mutations and both sexes with the hMLH1 groups only demonstrated a smoking effect after an extensive smoking history (P < 0.05).

CONCLUSION: CRC promotion by smoking in HNPCC patients is dependent on gene mutation, gender and age. …

Trees And Ice Storms: The Development Of Ice Storm–Resistant Urban Tree Populations (Second Edition), Richard J. Hauer, Jeffrey O. Dawson, Les P. Werner

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Severe ice storms occur every year in the United States and Canada, particularly in the midwestern and eastern regions of the United States. Along with fires and wind, ice storms are a frequent and major natural disturbance factor in eastern deciduous forests. Likewise ice storms are responsible for deaths and injuries of people and cause dramatic damage and tree loss to urban forests. Ice storms annually result in millions of dollars in loss, and potentially billions of dollars in losses for extreme and widespread ice storms. Damage to electric distribution systems, blocked roadways, and property damage from fallen trees and …

Nonintrusive Mapping Of Near-Surface Preferential Flow, R. S. Freeland, Lameck O. Odhiambo, J. S. Tyner, J. T. Ammons, W. C. Wright

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A unique survey protocol has been developed that maps near-subsurface preferential flow using integrated ground-penetrating radar (GPR) and a differential geographical positioning system (DGPS). The survey protocol consists of a mobile GPR system that spirals outward along a prescribed course, continuously gathering subsurface data for an extended period. Metered water is applied to a centrally located water-ponding ring, after first capturing the initial dry-state pattern signatures. The water radiates outward beneath the surface as it follows preferential flow pathways, which the GPR instrumentation spiraling above highlights. After data are collected, pre- and post-water time-elapsed images profiles are segmented by pattern …

Development Of Multiple Growth Strategies For Use In Developing Traffic Forecasts: A Robustness Approach, Deogratias Eustace, Eugene R. Russell, E. Dean Landman

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Decisions that may be based on misleading forecasts may lead to a misallocation of funds and to under-performing projects during construction and operation. Poor projections of demographic and socioeconomic data are usually cited as the major source of poor traffic assignment projections and hence, unfavorably conceived planning and construction of street and highway infrastructure facilities.

This report evaluated the accuracy of long range projections by using a transportation study done the in 1970s, projecting transportation demand 20 years into the future. The projected travel model inputs were compared with what actually happened after the horizon year had been reached and …

Evaluation Of Methods For Estimating Daily Reference Crop Evapotranspiration At A Site In The Humid Southeast United States, R. E. Yoder, Lameck O. Odhiambo, Wesley C. Wright

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Estimated daily reference crop evapotranspiration (ET_o) is normally used to determine the water requirement of crops using the crop factor method. Many ET_o estimation methods have been developed for different types of climatic data, and the accuracy of these methods varies with climatic conditions. In this study, pair−wise comparisons were made between daily ET_o estimated from eight different ET_o equations and ET_o measured by lysimeter to provide information helpful in selecting an appropriate ET_o equation for the Cumberland Plateau located in the humid Southeast United States. Based on the standard error of the …

Remote Estimation Of Canopy Chlorophyll Content In Crops, Anatoly A. Gitelson, Andrés Viña, Veronica Ciganda, Donald Rundquist, Timothy J. Arkebauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate estimation of spatially distributed chlorophyll content (Chl) in crops is of great importance for regional and global studies of carbon balance and responses to fertilizer (e.g., nitrogen) application. In this paper a recently developed conceptual model was applied for remotely estimating Chl in maize and soybean canopies. We tuned the spectral regions to be included in the model, according to the optical characteristics of the crops studied, and showed that the developed technique allowed accurate estimation of total Chl in both crops, explaining more than 92% of Chl variation. This new technique shows great potential for remotely tracking the …