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Full-Text Articles in Engineering

Nutrient Transport In Runoff As Affected By Diet, Tillage, And Manure Application Rate, John E. Gilley, Lisa M. Durso, R.A. Eigenberg, David B. Marx, Brian L. Woodbury Nov 2010

Nutrient Transport In Runoff As Affected By Diet, Tillage, And Manure Application Rate, John E. Gilley, Lisa M. Durso, R.A. Eigenberg, David B. Marx, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

Feedlot operators may increase profitability by including distillers grains in finishing diets. However, the nutrients remaining in the by‐product are concentrated by about a factor of three during the distillation process. Manure can be applied to meet single‐ or multiple‐year crop nutrient requirements. The water quality effects of the use of distillers grains in feedlot diets and multiple‐year manure application have not been well quantified. The objectives of this study were to (1) compare the runoff water quality effects resulting from the application of manure derived from corn and distillers grain diets, (2) examine the effects of till and no‐till …


Comparison Of Subsurface And Surface Runoff Phosphorus Transport Capacities In Alluvial Floodplains, Aaron R. Mittelstet, Derek M. Heeren, Daniel E. Storm, Garey A. Fox, M. J. White, R. B. Miller Nov 2010

Comparison Of Subsurface And Surface Runoff Phosphorus Transport Capacities In Alluvial Floodplains, Aaron R. Mittelstet, Derek M. Heeren, Daniel E. Storm, Garey A. Fox, M. J. White, R. B. Miller

Biological Systems Engineering: Papers and Publications

There have been numerous studies on phosphorus (P) contributions from surface runoff, but studies comparing the contribution of surface versus subsurface P are limited, as subsurface transport is often considered negligible. Previous work has shown that the transport of P in the gravelly subsurface at two sites in northeast Oklahoma can be significant, especially in preferential flow paths (PFPs), hypothesized to be buried gravel bars. The objective of this project was to quantify subsurface P losses based on field data, and compare with surface runoff P losses derived from Pasture Phosphorus Management Calculator (PPM Plus) simulations. Ozark ecoregion study sites …


The Other Gulf Oil Crisis - In Southwest Asia, Adam Liska Aug 2010

The Other Gulf Oil Crisis - In Southwest Asia, Adam Liska

Biological Systems Engineering: Papers and Publications

The oil spill in the Gulf of Mexico is a rude reminder of the risks inherent in an economy dependent upon petroleum. But there's a quieter crisis in the other gulf - the Persian Gulf - that should call Americans' attention to the even more severe consequences of relying upon imported oil. The costs of using the military to protect the transport of oil from the most turbulent part of the world should convince our country's policymakers to increase investments in researching and developing affordable, American-made clean-burning alternative fuels. But, first, we have to understand the real causes, costs and …


Enhanced Anthocyanin Extraction From Red Cabbage Using Pulsed Electric Field Processing, Tanya K. Gachovska, David A. Cassada, Jeyamkondan Subbiah, Milford Hanna, Harshavardhan Thippareddi, Daniel D. Snow Aug 2010

Enhanced Anthocyanin Extraction From Red Cabbage Using Pulsed Electric Field Processing, Tanya K. Gachovska, David A. Cassada, Jeyamkondan Subbiah, Milford Hanna, Harshavardhan Thippareddi, Daniel D. Snow

Biological Systems Engineering: Papers and Publications

This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher …


Securing Foreign Oil: A Case For Including Military Operations In The Climate Change Impact Of Fuels, Adam J. Liska, Richard K. Perrin Jul 2010

Securing Foreign Oil: A Case For Including Military Operations In The Climate Change Impact Of Fuels, Adam J. Liska, Richard K. Perrin

Biological Systems Engineering: Papers and Publications

Military operations are major industrial activities that use massive amounts of fuel and materials that significantly contribute to climate change. In this article, we assert that military activity to protect international oil trade is a direct production component for importing foreign oil— as necessary for imports as are pipelines and supertankers—and therefore the greenhouse gas (GHG) emissions from that military activity are relevant to U.S. fuel policies related to climate change. Military security for protection of global maritime petroleum distribution is part of the acquisition process, but in addition, recent Middle Eastern wars may also be related to securing petroleum …


Impact Of Preferential Flow Paths On Alluvial Groundwater Flow Patterns And Phosphorus Transport, Derek M. Heeren, Ronald B. Miller, Garey A. Fox, Daniel E. Storm, Aaron R. Mittelstet, Chad J. Penn Jun 2010

Impact Of Preferential Flow Paths On Alluvial Groundwater Flow Patterns And Phosphorus Transport, Derek M. Heeren, Ronald B. Miller, Garey A. Fox, Daniel E. Storm, Aaron R. Mittelstet, Chad J. Penn

Biological Systems Engineering: Papers and Publications

While surface runoff is considered to be the primary transport mechanism for phosphorus (P), subsurface transport through coarse subsoil to gravel bed streams may be significant and represent a source of P not alleviated by current conservation practices (e.g., riparian buffers). Previous research has documented P transport in a preferential flow path (PFP) identified as a buried gravel bar. It is hypothesized that PFPs, if connected to the soil surface, provide a rapid and efficient method of transporting P, and that these alluvial features are transient storage zones for nutrients, acting as a sink during high flow and a source …


Geophysical Mapping Of Preferential Flow Paths Across Multiple Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Todd Halihan, Aaron R. Mittelstet Jun 2010

Geophysical Mapping Of Preferential Flow Paths Across Multiple Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Todd Halihan, Aaron R. Mittelstet

Biological Systems Engineering: Papers and Publications

In the Ozark ecoregion of Oklahoma, Arkansas and Missouri, the erosion of carbonate bedrock (primarily limestone) by slightly acidic water has left a residuum of chert gravel, producing gravel-bed streams and floodplains generally consisting of coarse chert gravel overlain by a mantle (1 to 300 cm) of gravelly loam or silt loam. Previous research has documented the occurrence of preferential flow paths (PFP) in an alluvial floodplain hypothesized to be a buried gravel bar. Field experiments have shown that the PFP affected alluvial groundwater flow in the floodplain and that water flow in the PFP was transmitted at rates that …


Optimization And Economic Evaluation Of Industrial Gas Production And Combined Heat And Power Generation From Gasification Of Corn Stover And Distillers Grains, Ajay Kumar, Yaşar Demirel, David D. Jones, Milford Hanna May 2010

Optimization And Economic Evaluation Of Industrial Gas Production And Combined Heat And Power Generation From Gasification Of Corn Stover And Distillers Grains, Ajay Kumar, Yaşar Demirel, David D. Jones, Milford Hanna

Biological Systems Engineering: Papers and Publications

Thermochemical gasification is one of the most promising technologies for converting biomass into power, fuels and chemicals. The objectives of this study were to maximize the net energy efficiency for biomass gasification, and to estimate the cost of producing industrial gas and combined heat and power (CHP) at a feedrate of 2,000 kg/h. Aspen Plusbased model for gasification was combined with a CHP generation model, and optimized using corn stover and dried distillers grains with solubles (DDGS) as the biomass feedstocks. The cold gas efficiencies for gas production were 57% and 52%, respectively, for corn stover and DDGS. The selling …


Nutrient Transport In Runoff From Feedlots As Affected By Wet Distillers Grain Diet, John E. Gilley, Jason R. Vogel, Roger A. Eigenberg, David B. Marx, Brian L. Woodbury Mar 2010

Nutrient Transport In Runoff From Feedlots As Affected By Wet Distillers Grain Diet, John E. Gilley, Jason R. Vogel, Roger A. Eigenberg, David B. Marx, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

Distillers byproducts can serve as valuable sources of protein and energy for beef cattle. However, the water quality effects of the use of distillers byproducts in cattle rations are not well understood. The objectives of this study were to: (1) measure soil properties and nutrient transport in runoff from feedlot surfaces as affected by corn‐based and wet distillers grain diets, (2) compare the effects of unconsolidated surface materials and consolidated subsurface materials on feedlot soil characteristics and runoff nutrient transport, (3) determine if runoff nutrient transport from feedlot surfaces is correlated to selected feedlot soil properties, and (4) identify the …


Cytotoxicity Of Bacterial-Derived Toxins To Immortal Lung Epithelial And Macrophage Cells, Dianne E. Peterson, Jayne M. Collier, Matthew E. Katterman, Rachel A. Turner, Mark R. Riley Feb 2010

Cytotoxicity Of Bacterial-Derived Toxins To Immortal Lung Epithelial And Macrophage Cells, Dianne E. Peterson, Jayne M. Collier, Matthew E. Katterman, Rachel A. Turner, Mark R. Riley

Biological Systems Engineering: Papers and Publications

Health risks associated with inhalation and deposition of biological materials have been a topic of great concern due to highly publicized cases of inhalation anthrax, of new regulations on the release of particulate matter, and to increased concerns on the hazards of indoor air pollution. Here, we present an evaluation of the sensitivity of two immortal cell lines (A549, human lung carcinoma epithelia) and NR8383 (rat alveolar macrophages) to a variety of bacterial-derived inhalation hazards and simulants including etoposide, gliotoxin, streptolysin O, and warfarin. The cell response is evaluated through quantification of changes in mitochondrial succinate dehydrogenase activity, release of …


On The Dynamics Of Canopy Resistance: Generalized Linear Estimation And Relationships With Primary Micrometeorological Variables, Suat Irmak, Denis Mutiibwa Jan 2010

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

Biological Systems Engineering: Papers and 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 (rc) data for different vegetation surfaces. rc could be estimated by inversion of the PM model if the actual evapotranspiration (ETa) rate is known, but this approach has its own set of issues. Instead, an empirical method of estimating rc is suggested in this study. We investigated the relationships between primary micrometeorological parameters and rc and developed seven models to estimate rc for a nonstressed maize canopy on an hourly …


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 Jan 2010

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

Biological Systems Engineering: Papers and 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, …


Testing Fuel Efficiency Of A Tractor With A Continuously Variable Transmission, Bart A. Coffman, Michael F. Kocher, Viacheslav I. Adamchuk, Roger M. Hoy, Erin E. Blankenship Jan 2010

Testing Fuel Efficiency Of A Tractor With A Continuously Variable Transmission, Bart A. Coffman, Michael F. Kocher, Viacheslav I. Adamchuk, Roger M. Hoy, Erin E. Blankenship

Biological Systems Engineering: Papers and Publications

A John Deere 8530 IVT tractor (Waterloo, Iowa) with a continuously variable transmission (CVT) that could be operated in automatic (CVT) or manual (fixed gear ratio) mode was tested for fuel consumption at a setpoint travel speed of 9 km·h‐1 with 17 different drawbar loads. Linear regression analysis results showed that with the throttle set to maximum in both transmission modes, operating the tractor with the transmission in the automatic mode was more fuel efficient than operating with the transmission in the manual mode when the drawbar power was approximately 78%, or less, of maximum power. When load transition …


Testing Of Rtk-Level Satellite-Based Tractor Auto-Guidance Using A Visual Sensor System, Dwight Easterly, Viacheslav I. Adamchuk, Roger M. Hoy, Michael F. Kocher Jan 2010

Testing Of Rtk-Level Satellite-Based Tractor Auto-Guidance Using A Visual Sensor System, Dwight Easterly, Viacheslav I. Adamchuk, Roger M. Hoy, Michael F. Kocher

Biological Systems Engineering: Papers and Publications

The use of satellite-based positioning has advanced considerably in the world of agriculture, providing a range of technical solutions that include the automated steering of tractors and self-propelled machinery. With the development of auto-guidance systems comes the need to evaluate their performance. Given that current precision and accuracy claims are relatively small in magnitude, it is imperative there be a testing system capable of detecting errors with ten times greater accuracy-- possibly as little as a few millimeters. A visual sensor was adopted to achieve this level of measurement resolution. The sensor was used to determine the cross-track error estimates …


Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng Jan 2010

Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

This study used two different approaches to model changes in biomass composition during microwave-based pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the pretreatment. Training and testing data sets for development and validation of the models were obtained from pretreatment experiments conducted using 1–3% w/v NaOH (sodium hydroxide) and pretreatment times ranging from 5 to 20 min. The kinetic modeling approach for lignin …


Net Radiation Dynamics: Performance Of 20 Daily Net Radiation Models As Related To Model Structure And Intricacy In Two Climates, Suat Irmak, Denis Mutiibwa, José O. Payero Jan 2010

Net Radiation Dynamics: Performance Of 20 Daily Net Radiation Models As Related To Model Structure And Intricacy In Two Climates, Suat Irmak, Denis Mutiibwa, José O. Payero

Biological Systems Engineering: Papers and Publications

We compared daily net radiation (Rn) estimates from 19 methods with the ASCE‐EWRI Rn estimates in two climates: Clay Center, Nebraska (sub‐humid) and Davis, California (semi‐arid) for the calendar year. The performances of all 20 methods, including the ASCE‐EWRI Rn method, were then evaluated against Rn data measured over a non‐stressed maize canopy during two growing seasons in 2005 and 2006 at Clay Center. Methods differ in terms of inputs, structure, and equation intricacy. Most methods differ in estimating the cloudiness factor, emissivity (α), and calculating net longwave radiation (Rnl). All methods use …


Nebraska Water And Energy Flux Measurement, Modeling, And Research Network (Nebflux), Suat Irmak Jan 2010

Nebraska Water And Energy Flux Measurement, Modeling, And Research Network (Nebflux), Suat Irmak

Biological Systems Engineering: Papers and Publications

Surface energy and water vapor fluxes play a critical role in understanding the response of agro‐ecosystems to changes in environmental and atmospheric parameters. These fluxes play a crucial role in exploring the dynamics of water and energy use efficiencies of these systems. Quantification of the fluxes is also necessary for assessing the impact of land use and management changes on water balances. Accomplishing these goals requires measurement of water vapor and energy exchanges between various vegetation surfaces and microclimates for long‐enough periods to understand the behavior and dynamics involved with the flux transfer so that robust models can be developed …


Preferential Flow Effects On Subsurface Contaminant Transport In Alluvial Floodplains, Derek M. Heeren, Ron B. Miller, Garey A. Fox, Daniel E. Storm, Todd Halihan, Chad J. Penn Jan 2010

Preferential Flow Effects On Subsurface Contaminant Transport In Alluvial Floodplains, Derek M. Heeren, Ron B. Miller, Garey A. Fox, Daniel E. Storm, Todd Halihan, Chad J. Penn

Biological Systems Engineering: Papers and Publications

For sorbing contaminants, transport from upland areas to surface water systems is typically considered to be due to surface runoff, with negligible input from subsurface transport assumed. However, certain conditions can lead to an environment where subsurface transport to streams may be significant. The Ozark region, including parts of Oklahoma, Arkansas, and Missouri, is one such environment, characterized by cherty, gravelly soils and gravel bed streams. Previous research identified a preferential flow path (PFP) at an Ozark floodplain along the Barren Fork Creek in northeastern Oklahoma and demonstrated that even a sorbing contaminant, i.e., phosphorus, can be transported in significant …


Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng Jan 2010

Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Coastal Bermuda grass was pretreated with NaOH at concentrations from 0.5% to 3% (w/v) for a residence time from 15 to 90 min at 121 °C. The pretreatments were evaluated based on total lignin removal and production of total reducing sugars, glucose and xylose from enzymatic hydrolysis of the pretreated biomass. Up to 86% lignin removal was observed. The optimal NaOH pretreatment conditions at 121 °C for total reducing sugars production as well as glucose and xylose yields are 15 min and 0.75% NaOH. Under these optimal pretreatment conditions, total reducing sugars yield was about 71% of the theoretical maximum, …


Using A Vision Sensor System For Performance Testing Of Satellite-Based Tractor Auto-Guidance, Dwight Easterly, Viacheslav I. Adamchuk, Michael F. Kocher, Roger M. Hoy Jan 2010

Using A Vision Sensor System For Performance Testing Of Satellite-Based Tractor Auto-Guidance, Dwight Easterly, Viacheslav I. Adamchuk, Michael F. Kocher, Roger M. Hoy

Biological Systems Engineering: Papers and Publications

A vision sensing system for the measurement of auto-guidance pass-to-pass and long-term errors was implemented to test the steering performance of tractors equipped with auto-guidance systems. The developed test system consisted of an optical machine vision sensor rigidly mounted on the rear of the tested tractor. The center of the drawbar hitch pin point was used as the reference from which to measure the deviation of the tractor’s actual travel path from its desired path. The system was built and calibrated to a measurement accuracy of better than 2 mm. To evaluate the sensor, two auto-guidance systems equipped with RTK-level …


Dual-Stage Sugar Substitution In Strawberries With A Stevia-Based Sweetener, Juan Garcia-Noguera, Curtis L. Weller, Francisca I. P. Oliveira, Sueli Rodrigues, Fabiano A. N. Fernandes Jan 2010

Dual-Stage Sugar Substitution In Strawberries With A Stevia-Based Sweetener, Juan Garcia-Noguera, Curtis L. Weller, Francisca I. P. Oliveira, Sueli Rodrigues, Fabiano A. N. Fernandes

Biological Systems Engineering: Papers and Publications

The present study introduces and analyzes a new process denominated dual-stage sugar substitution (D3S). This process aims to induce sugar substitution in strawberries. In a first stage, high-calorie sugars (sucrose, fructose and glucose) are partially removed from the fruit samples and in a second stage, low-calorie sugar (stevioside and rebaudioside) is incorporated to the fruit to maintain its sweetness. The process was evaluated by studying the use of ultrasound application in one or both stages of the D3S process. Best performance of the process was obtained by subjecting the fruit samples to ultrasound in the sugar removal stage followed by …


Ultrasound-Assisted Osmotic Dehydration Of Strawberries: Effect Of Pretreatment Time And Ultrasonic Frequency, Juan Garcia-Noguera, Francisca I. P. Oliveira, Maria Izabel Gallão, Curtis L. Weller, Sueli Rodrigues, Fabiano A. N. Fernandes Jan 2010

Ultrasound-Assisted Osmotic Dehydration Of Strawberries: Effect Of Pretreatment Time And Ultrasonic Frequency, Juan Garcia-Noguera, Francisca I. P. Oliveira, Maria Izabel Gallão, Curtis L. Weller, Sueli Rodrigues, Fabiano A. N. Fernandes

Biological Systems Engineering: Papers and Publications

Pretreatment of fruits prior to drying has shown success in reducing drying time and costs. In this work, ultrasound-assisted osmotic dehydration has been implemented as a method to increase water diffusivity and reduce drying time in strawberries. Strawberry halves were immersed in distilled water and in two different concentrations of sucrose solutions while pretreatment time and ultrasonic frequency levels were varied to determine their effect on drying time, water loss, and soluble solids gain. A microscopic analysis was carried out to evaluate the formation of microchannels and other changes to the fruit tissue structure. Greater sucrose concentration used in ultrasound- …


Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang Jan 2010

Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang

Biological Systems Engineering: Papers and Publications

This paper reports a new method of cross-linking electrospun zein fibers using citric acid as a non-toxic cross-linker to enhance the water stability and cytocompatibility of zein fibers for tissue engineering and other medical applications. The electrospun structure has many advantages over other types of structures and protein-based biomaterials possess unique properties preferred for tissue engineering and other medical applications. However, ultrafine fiber matrices developed from proteins have poor mechanical properties and morphological stability in the aqueous environments required for medical applications. Efforts have been made to improve the water stability of electrospun protein scaffolds using cross-linking and other approaches, …


Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng Jan 2010

Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave- based alkali pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 min. Simons’ stain method was used to quantify changes in biomass porosity as a result of the pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and …


Numerically Predicting Seepage Gradient Forces And Erosion: Sensitivity To Soil Hydraulic Properties, Garey A. Fox, Derek M. Heeren, Glenn V. Wilson, E. J. Langendoen, Amanda K. Fox, Maria L. Chu-Agor Jan 2010

Numerically Predicting Seepage Gradient Forces And Erosion: Sensitivity To Soil Hydraulic Properties, Garey A. Fox, Derek M. Heeren, Glenn V. Wilson, E. J. Langendoen, Amanda K. Fox, Maria L. Chu-Agor

Biological Systems Engineering: Papers and Publications

Research has suggested that streambank seepage can be an important mechanism of bank instability; however, limited information is available on the level of soil characterization necessary to accurately predict seepage gradient forces and erosion. The objective of this research was to quantify the expected range of predicted seepage gradients for various degrees of site characterization. Uncertainty analysis on seepage gradient predictions was performed relative to variability in soil hydraulic properties. A two-dimensional unsaturated/saturated groundwater flow model was used to simulate a homogeneous soil layer for sand and loamy sand soils packed at various bulk densities, ρb. A pedotransfer …


Extrusion Systems: Components, Qi Fang, Milford Hanna Jan 2010

Extrusion Systems: Components, Qi Fang, Milford Hanna

Biological Systems Engineering: Papers and Publications

An extrusion system can be very simple to very complex. The complexity, or versatility, of a particular system is determined by the range of feedstocks to be processed, the desired transformations of the feedstocks, and the desired form of the products resulting from the process. These determine the specific design requirements of the various components of an extrusion system.


Opto-Electrophoretic Detection Of Bio-Molecules Using Conducting Chalcogenide Glass Sensors, Zhiyong Yang, Megan K. Fah, Kelly A. Reynolds, Jonathan D. Sexton, Mark R. Riley, Marie-Laure Anne, Bruno Bureau, Pierre Lucas Jan 2010

Opto-Electrophoretic Detection Of Bio-Molecules Using Conducting Chalcogenide Glass Sensors, Zhiyong Yang, Megan K. Fah, Kelly A. Reynolds, Jonathan D. Sexton, Mark R. Riley, Marie-Laure Anne, Bruno Bureau, Pierre Lucas

Biological Systems Engineering: Papers and Publications

Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorganisms. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the migration of bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested …


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 Jan 2010

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

Biological Systems Engineering: Papers and 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 Jan 2010

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

Biological Systems Engineering: Papers and 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, …