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Full-Text Articles in Biomedical Engineering and Bioengineering

A Modified Surface Energy Balance For Modeling Evapotranspiration And Canopy Resistance, Luis O. Lagos Dec 2008

A Modified Surface Energy Balance For Modeling Evapotranspiration And Canopy Resistance, Luis O. Lagos

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

A modified surface energy balance (SEB) model based on the Shuttleworth-Wallace and Choudhury-Monteith methods was developed to estimate evaporation from soil covered by crop residue, and transpiration from crop canopies. The model describes the energy balance and flux resistances for partially-vegetated and residue-covered surfaces. Physical and biochemical energy storage terms and lateral fluxes are neglected in the model. Net radiation is one of the inputs in the SEB model and provides the energy needed for soil evaporation, crop transpiration and heat transfer through the canopy, soil/residue surfaces and the atmosphere.

A sensitivity analysis of the SEB model parameters showed that …


Department Of Biological Systems Engineering Newsletter, Vol. 4 No. 2, December 2008 Dec 2008

Department Of Biological Systems Engineering Newsletter, Vol. 4 No. 2, December 2008

BSE Department Magazine

Environmental Management Research
From the Department Head
Meet the Faculty
Alumni News
Comings and Goings
Alumna Profile
In Memoriam
Museum Hand-picked for HELP
Urban Water Quality
Summer Graduates
Distinguished Fellowship Awards
Partners in Pollution Prevention Interns
Quarter-scale Tractor Competition
Scholarships and Ice Cream
BSE faculty develop Odor Footprint Tool By Crystal Powers
Ethanol Co-product Storage and Utilization Conference By John Hay
Biological Systems Engineering Department Hall of Fame: Don Eret and Ned Meier
International Symposium
Faculty & Staff News
University Service Awards
ASABE Annual Meeting


Monitoring Tissue Engineering Using Magnetic Resonance Imaging, Huihui Xu, Shadi F. Othman, Richard L. Magin Dec 2008

Monitoring Tissue Engineering Using Magnetic Resonance Imaging, Huihui Xu, Shadi F. Othman, Richard L. Magin

Biological Systems Engineering: Papers and Publications

Assessment of tissue regeneration is essential to optimize the stages of tissue engineering (cell proliferation, tissue development and implantation). Optical and X-ray imaging have been used in tissue engineering to provide useful information, but each has limitations: for example, poor depth penetration and radiation damage. Magnetic resonance imaging (MRI) largely overcomes these restrictions, exhibits high resolution (approximately 100 μm) and can be applied both in vitro and in vivo. Recently, MRI has been used in tissue engineering to generate spatial maps of tissue relaxation times (T1, T2), water diffusion coefficients, and the stiffness (shear moduli) of …


Extracellular Matrix Protein Orientation By Adsorption On Self-Assembled Monolayers Controls Nonviral Gene Delivery, Beth A. Duensing, Angela K. Pannier Nov 2008

Extracellular Matrix Protein Orientation By Adsorption On Self-Assembled Monolayers Controls Nonviral Gene Delivery, Beth A. Duensing, Angela K. Pannier

Department of Biological Systems Engineering: Conference Presentations and White Papers

To date, most efforts to understand and improve the efficiency of nonviral gene delivery have focused on altering the physicochemical properties of delivery systems and developing new delivery strategies. The importance of the cellular microenvironment in achieving successful nonviral gene transfer has not been thoroughly examined, though proteins of the extracellular matrix (ECM) mediate cell adhesion and serve to regulate cellular behavior that may, in turn, dictate the cellular responsiveness to nonviral gene delivery. Self-assembled monolayers (SAMs) of alkanethiols on gold were used to control adsorption of ECM molecules and thus control the architecture of the extracellular environment presented to …


Metabolic Engineering Of A Thermophilic Bacterium To Produce Ethanol At High Yield, A. Joe Shaw, Kara K. Podkaminer, Sunil G. Desai, John S. Bardsley, Stephen R. Rogers, Philip G. Thorne, David A. Hogsett, Lee R. Lynd Sep 2008

Metabolic Engineering Of A Thermophilic Bacterium To Produce Ethanol At High Yield, A. Joe Shaw, Kara K. Podkaminer, Sunil G. Desai, John S. Bardsley, Stephen R. Rogers, Philip G. Thorne, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

We report engineering Thermoanaerobacterium saccharolyticum, a thermophilic anaerobic bacterium that ferments xylan and biomass-derived sugars, to produce ethanol at high yield. Knockout of genes involved in organic acid formation (acetate kinase, phosphate acetyltransferase, and L-lactate dehydrogenase) resulted in a strain able to produce ethanol as the only detectable organic product and substantial changes in electron flow relative to the wild type. Ethanol formation in the engineered strain (ALK2) utilizes pyruvate:ferredoxin oxidoreductase with electrons transferred from ferredoxin to NAD(P), a pathway different from that in previously described microbes with a homoethanol fermentation. The homoethanologenic phenotype was stable for >150 generations …


Department Of Biological Systems Engineering Newsletter, Vol. 4 No. 1, August 2008 Aug 2008

Department Of Biological Systems Engineering Newsletter, Vol. 4 No. 1, August 2008

BSE Department Magazine

Contents:
New Biomedical Lab Makes Debut
From the Department Head
The Dean's List
Meet the Faculty
Alumni News
Student News
UCARE
Graduates
John Miller: A Success Story
Discover Your Career Mechanized Systems Management
Alumnus Profile
Faculty and Staff News
Comings and Goings
Spreading the word about No-till


A Design Aid For Determining Width Of Filter Strips, Michael G. Dosskey, M. J. Helmers, Dean E. Eisenhauer Aug 2008

A Design Aid For Determining Width Of Filter Strips, Michael G. Dosskey, M. J. Helmers, Dean E. Eisenhauer

Biological Systems Engineering: Papers and Publications

Watershed planners need a tool for determining width of filter strips that is accurate enough for developing cost-effective site designs and easy enough to use for making quick determinations on a large number and variety of sites. This study employed the process-based Vegetative Filter Strip Model to evaluate the relationship between filter strip width and trap¬ping efficiency for sediment and water and to produce a design aid for use where specific water quality targets must be met. Model simulations illustrate that relatively narrow filter strips can have high impact in some situations, while in others even a modest impact cannot …


Preparing, Characterizing, On-Line Digital Image Processing Of Residence Time Distribution And Modeling Of Mechanical Properties Of Nanocomposite Foams, Siew Yoong Lee Jul 2008

Preparing, Characterizing, On-Line Digital Image Processing Of Residence Time Distribution And Modeling Of Mechanical Properties Of Nanocomposite Foams, Siew Yoong Lee

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

The objectives of this research were to prepare, characterize and to study the effects of organoclay and extrusion variables on the physical, mechanical, structural, thermal and functional properties of tapioca starch (TS)/poly(lactic acid) (PLA) nanocomposite foams. On-line digital imaging processing was used to determine residence time distribution (RTD). Adaptive neuro-fuzzy inference system (ANFIS) was used to model the mechanical properties of nanocomposite foams.

Four different organoclays (Cloisite 10A, 25A, 93A, 15A) were used to produce nanocomposite foams by melt-intercalation. The properties were characterized using Xray diffraction, scanning electron microscopy, differential scanning calorimetric, and Instron universal testing machine. The properties were …


Effects Of Narrow Grass Hedges On Nutrient Transport From Land Application Areas, John E. Gilley, Bahman Eghball, David B. Marx Jul 2008

Effects Of Narrow Grass Hedges On Nutrient Transport From Land Application Areas, John E. Gilley, Bahman Eghball, David B. Marx

Department of Biological Systems Engineering: Conference Presentations and White Papers

The placement of stiff-stemmed grass hedges on the contour along a hill slope has been shown to decrease runoff nutrient transport. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted beef cattle manure was applied at dry weights of 0, 68, 105, 142, and 178 Mg ha-1 to a silty clay loam soil and then incorporated by disking. Soil samples were collected 243 days later for analysis of water-soluble phosphorus (WSP), Bray and Kurtz No.1 phosphorus (Bray-1 P), NO3 …


Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury Jul 2008

Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury

Department of Biological Systems Engineering: Conference Presentations and White Papers

Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site-specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: a) measure selected feedlot soil properties, and nutrient and microbial transport in runoff from various feedlot locations b) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and microbial transport, and c) …


Methods To Prioritize Placement Of Riparian Buffers For Improved Water Quality, M. D. Tomer, Michael G. Dosskey, Michael R. Burkart, Matthew J. Helmers, Dean E. Eisenhauer May 2008

Methods To Prioritize Placement Of Riparian Buffers For Improved Water Quality, M. D. Tomer, Michael G. Dosskey, Michael R. Burkart, Matthew J. Helmers, Dean E. Eisenhauer

Biological Systems Engineering: Papers and Publications

Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying and mapping locations where agroforestry buffers can effectively improve water quality. One technique employs soil survey information to rank soil map units for how effectively a buffer, when sited on them, would trap sediment from adjacent cropped fields. Results allow soil map units to be compared for relative effectiveness of buffers …


Aquatic Bacteria Removal Using Carbon Nanotubes, Suvish Melanta May 2008

Aquatic Bacteria Removal Using Carbon Nanotubes, Suvish Melanta

Biological and Agricultural Engineering Undergraduate Honors Theses

The purpose of this project is to explore the functionality of carbon nanotubes as a bacterial removal method, specifically towards water-borne bacterial pathogens in wastewater by utilizing its unique magnetic and bacteria-binding properties. The general protocol set for this research follows five steps: 1) Preparation of wastewater media, 2) preparation of CNT culture, 3) preparation of reaction mixture with CNTs for bacterial binding, 4) magnetic separation of bacteria-bound-CNT clusters and, 5) assessment of supernatant. The CNTs effectively removed bacterial contaminants in the wastewater (10%, v/v) after the sand filtration process from the Paul R. Noland Wastewater Facility at Fayetteville, Arkansas. …


Cellular Arrays (Us Patent Application), Angela K. Pannier, Eric A. Ariazi, V. Craig Jordan, Lonnie D. Shea May 2008

Cellular Arrays (Us Patent Application), Angela K. Pannier, Eric A. Ariazi, V. Craig Jordan, Lonnie D. Shea

Biological Systems Engineering: Papers and Publications

The present invention relates to characterizing transcription within cells. In particular, the present invention provides transfected cell arrays (e.g., two-dimensional and/or three-dimensional arrays) and systems, kits and methods utilizing the same (e.g., for transcriptional activity characterization). Compositions and methods of the present invention find use in, among other things, research, drug discovery and clinical (e.g., diagnostic, preventative and therapeutic) applications.


Artificial Neural Network Estimation Of Soil Erosion And Nutrient Concentrations In Runoff From Land Application Areas, Minyoung Kim, John E. Gilley May 2008

Artificial Neural Network Estimation Of Soil Erosion And Nutrient Concentrations In Runoff From Land Application Areas, Minyoung Kim, John E. Gilley

Biological Systems Engineering: Papers and Publications

The transport of sediment and nutrients from land application areas is an environmental concern. New methods are needed for estimating soil and nutrient concentrations of runoff from cropland areas on which manure is applied. Artificial Neural Networks (ANNs) trained with a backpropagation (BP) algorithm were used to estimate soil erosion, dissolved P (DP) and NH4–N concentrations of runoff from a land application site near Lincoln, Nebraska, USA. Simulation results from ANN-derived models showed that the amount of soil eroded is positively correlated with rainfall and runoff. In addition, concentrations of DP and NH4–N in overland flow …


Computational Modeling Of Oxidative Stress: An Analysis Of Nad (P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel May 2008

Computational Modeling Of Oxidative Stress: An Analysis Of Nad (P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel

Biological and Agricultural Engineering Undergraduate Honors Theses

Nitric oxide (NO) is inactivated in the human body when exposed to superoxide (O2 -). This reaction forms peroxynitrite (ONOO-). Superoxide is produced in the cardiac system by several different ways, including NAD(P)H oxidase. Superoxide dismutase (SOD) breaks down superoxide into oxygen and hydrogen peroxide. This prevents superoxide from reacting with nitric oxide and allows normal function to take place. Superoxide and peroxynitrite are main contributors to vascular disease in the human body, in particular hypertension. Experiments have shown that there was an increase of superoxide production in spontaneously hypertensive rats (SHR) vs. age-matched Wistar Kyoto rats (WKY) that were …


The Effect Of Water Extracted Silibinin On Reactive Oxygen Species (Ros) Production Of Macrophages, Julie Abbott, Sunny Wallace, Ed Clausen, Danielle Carrier May 2008

The Effect Of Water Extracted Silibinin On Reactive Oxygen Species (Ros) Production Of Macrophages, Julie Abbott, Sunny Wallace, Ed Clausen, Danielle Carrier

Biological and Agricultural Engineering Undergraduate Honors Theses

The world is actively looking for technology to produce sustainable liquid fuels to replace our reliance on petroleum-based fuels. Biomass can be converted either through the thermochemical or saccharification platforms into fuels such as ethanol or butanol. In addition to converting the biomass into liquid fuels, valuable phytochemicals can be extracted prior, during, or after the conversion. Extracting useful phytochemicals, as a part of the overall conversion of biomass to fuels, is included in the concept of the biobased biorefinery. However, the key to effectively and economically extract phytochemicals from biomass is the ability to couple the extraction to the …


Narrow Grass Hedge Effects On Nutrient Transport Following Compost Application, John E. Gilley, Bahman Eghball, David B. Marx May 2008

Narrow Grass Hedge Effects On Nutrient Transport Following Compost Application, John E. Gilley, Bahman Eghball, David B. Marx

Biological Systems Engineering: Papers and Publications

The placement of stiff‐stemmed grass hedges on the contour along a hillslope has been shown to decrease nutrient transport in runoff. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted beef cattle manure was applied at dry weights of 0, 68, 105, 142, and 178 Mg ha-1 to a silty clay loam soil and then incorporated by disking. Soil samples were collected 243 days later for analysis of water‐soluble phosphorus (WSP), Bray and Kurtz No. 1 phosphorus (Bray‐1 P), NO …


Developing Lcfs For Biofuels: Getting It Right For Corn Ethanol, Kenneth Cassman, Adam Liska Apr 2008

Developing Lcfs For Biofuels: Getting It Right For Corn Ethanol, Kenneth Cassman, Adam Liska

Adam Liska Papers

• Corn ethanol will be first to test the newly developed LCFS assessment methods; substantial amounts of other biofuels will come several years later

• Accurate valuation of direct-effect GHG emissions from corn ethanol is the foundation of the LCFS process; these affects vary with ethanol biorefinery type and corn feedstock supply

• Different reference GHG emissions values are needed for each major class of ethanol plants

• The BESS model provides the most up-to-date, scientifically sound estimate of corn-ethanol GHG emissions; can BESS and GREET reach agreement?

• Certification and compliance tools are also needed


Modeling Electric Fields In Microfluidic Devices, Micah Fincher Apr 2008

Modeling Electric Fields In Microfluidic Devices, Micah Fincher

Honors Theses

No abstract provided.


An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones Mar 2008

An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones

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

Tapioca starch, poly(lactic acid) and Cloisite 30B nanocomposites foams, with clay contents of 1, 3, 5 and 7% (w/w), were prepared by a meltintercalation method. Multiple inputs single output models were developed to predict radial expansion ratio, unit density, bulk compressibility and spring index of the nanocomposite foams. An individual ANFIS model was developed for each mechanical property using clay content, temperature, pressure and torque as input parameters. All models preformed well with R2 values > 0.71. All models had very low root mean squared error values.


Spatial Variations In Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury Mar 2008

Spatial Variations In Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury

Biological Systems Engineering: Papers and Publications

Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site‐specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: (1) measure selected feedlot soil properties and nutrient and microbial transport in runoff from various feedlot locations, (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 microbial transport, and (3) …


Preparation And Characterization Of Tapioca Starch–Poly(Lactic Acid) Nanocomposite Foams By Melt Intercalation Based On Clay Type, Siew-Yoong Lee, Han Chen, Milford Hanna Jan 2008

Preparation And Characterization Of Tapioca Starch–Poly(Lactic Acid) Nanocomposite Foams By Melt Intercalation Based On Clay Type, Siew-Yoong Lee, Han Chen, Milford Hanna

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

Abstract Tapioca starch (TS), poly(lactic acid) (PLA), and four different organoclays (Cloisite 10A, Cloisite 25A, Cloisite 93A and Cloisite 15A) were used to produce nanocomposite foams by melt-intercalation. Structural, thermal, physical and mechanical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and an Instron universal testing machine, respectively. The first XRD peaks for all four nanocomposite foams, were observed to shift to lower angles, indicating that intercalation occurred. The extent of intercalation depended on the type of organoclay and was exhibited in the sequence of Cloisite 10A > 25A > 93A > 15A. Glass transition temperatures …


Pyrene Fate Affected By Humic Acid Amendment In Soil Slurry Systems, Y. Liang, D. Sorensen, Ronald C. Sims, Joan Mclean Jan 2008

Pyrene Fate Affected By Humic Acid Amendment In Soil Slurry Systems, Y. Liang, D. Sorensen, Ronald C. Sims, Joan Mclean

Biological Engineering Faculty Publications

Background

Humic acid (HA) has been found to affect the solubility, mineralization, and bound residue formation of polycyclic aromatic hydrocarbons (PAHs). However, most of the studies on the interaction between HA and PAH concentrated on one or two of the three phases. Few studies have provided a simple protocol to demonstrate the overall effects of HA on PAH distribution in soil systems for all three phases.

Methods

In this study, three doses of standard Elliott soil HA (ESHA), 15, 187.5, and 1,875 μg ESHA/g soil slurry, were amended to soil slurry systems. 14C-pyrene was added to the systems along …


Construction, Installation, And Performance Of Two Repacked Weighing Lysimeters, José O. Payero, Suat Irmak Jan 2008

Construction, Installation, And Performance Of Two Repacked Weighing Lysimeters, José O. Payero, Suat Irmak

Biological Systems Engineering: Papers and Publications

Weighing lysimeters are the standard method for directly measuring evapotranspiration (ET). This paper discusses the construction, installation, and performance of two (1.52 m × 1.52 m × 2.13-m deep) repacked weighing lysimeters for measuring ET of corn and soybean in West Central Nebraska. The cost of constructing and installing each lysimeter was approximately US $12,500, which could vary depending on the availability and cost of equipment and labor. The resolution of the lysimeters was 0.0001 mV V-1, which was limited by the data processing and storage resolution of the datalogger. This resolution was equivalent to 0.064 and 0.078 …


Field Slope Effects On Uniformity Of Corn Seed Spacing For Three Precision Planter Metering Systems, Corey L. Searle, Michael F. Kocher, John A. Smith, Erin E. Blankenship Jan 2008

Field Slope Effects On Uniformity Of Corn Seed Spacing For Three Precision Planter Metering Systems, Corey L. Searle, Michael F. Kocher, John A. Smith, Erin E. Blankenship

Biological Systems Engineering: Papers and Publications

The effects of field slope on planter seed spacing uniformity were evaluated for three different seed metering units (cell plate, finger pick‐up, and flat plate) operating with medium round corn seed in a laboratory using the University of Nebraska planter test stand with an opto‐electronic seed spacing sensor system. The metering units included a John Deere MaxEmerge™ Plus VacuMeter row unit with the standard cell corn plate, a John Deere MaxEmerge™ Plus VacuMeter row unit with the flat plate, and a John Deere MaxEmerge™ Plus row unit with the finger pick‐up metering system. Planter seed spacing uniformity was measured using …


Surface Polyethylene Glycol Enhances Substrate-Mediated Gene Delivery By Nonspecifically Immobilized Complexes, Angela K. Pannier, Julie A. Wieland, Lonnie D Shea Jan 2008

Surface Polyethylene Glycol Enhances Substrate-Mediated Gene Delivery By Nonspecifically Immobilized Complexes, Angela K. Pannier, Julie A. Wieland, Lonnie D Shea

Biological Systems Engineering: Papers and Publications

Substrate-mediated gene delivery describes the immobilization of gene therapy vectors to a biomaterial, which enhances gene transfer by exposing adhered cells to elevated DNA concentrations within the local microenvironment. Surface chemistry has been shown to affect transfection by nonspecifically immobilized complexes using self-assembled monolayers (SAMs) of alkanethiols on gold. In this report, SAMs were again used to provide a controlled surface to investigate whether the presence of oligo(ethylene glycol) (EG) groups in a SAM could affect complex morphology and enhance transfection. EG groups were included at percentages that did not affect cell adhesion. Nonspecific complex immobilization to SAMs containing combinations …


Pathogen Best Management Practices (Bmps), Richard K. Koelsch Jan 2008

Pathogen Best Management Practices (Bmps), Richard K. Koelsch

Department of Biological Systems Engineering: Conference Presentations and White Papers

Management practices targeting pathogens focus on establishing multiple barriers between the pathogen source and water, with each barrier designed to lessen the risk of pathogens. The “Agricultural Environmental Management” program developed at Cornell University for dairy producers in New York watersheds promotes a four-barrier approach.


High Temperature Dilute Acid Pretreatment Of Coastal Bermudagrass, Arthur Redding, Deepak R. Keshwani, Ziyu Wang, Jay J. Cheng Jan 2008

High Temperature Dilute Acid Pretreatment Of Coastal Bermudagrass, Arthur Redding, Deepak R. Keshwani, Ziyu Wang, Jay J. Cheng

Department of Biological Systems Engineering: Conference Presentations and White Papers

The conversion of lignocellulosic biomass into ethanol is an encouraging technology in the face of concerns over global warming and finite energy resources. In the southeastern United States, coastal bermudagrass shows potential for use as an energy crop for ethanol production. A review of the literature has shown that research has been done on the dilute sulfuric acid pretreatment of costal bermudagrass at 121ºC prior to enzymatic hydrolysis. This study examined dilute acid concentrations of 0.3%(w/w) to 1.2%(w/w) at temperatures from 120C to 180C over residence times of 5 to 60 minutes in an effort to optimize the pretreatment process …


Alkaline Pretreatment Of Coastal Bermudagrass For Bioethanol Production, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng Jan 2008

Alkaline Pretreatment Of Coastal Bermudagrass For Bioethanol Production, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng

Department of Biological Systems Engineering: Conference Presentations and White Papers

Lignocellulosic materials are regarded as an alternative energy source for bioethanol production to reduce our reliance on fossil fuels. Pretreatment is important for improving the enzymatic digestibility of lignocelluloses to increase the yield of fermentable sugars. Alkaline (sodium hydroxide and lime (calcium hydroxide)) pretreatment of coastal bermudagrass for enhanced reducing sugars recovery was investigated in this study. The effect of NaOH pretreatment at 121°C using 1%, 2% and 3% (w/v) NaOH for 15, 30, 60 and 90 minutes was evaluated first. Lower NaOH concentrations (0.5% and 0.75%) and lower temperatures (50, 80 and 100°C) were then examined. Lime (0.1 g …


Computational Modeling Of Oxidative Stress: An Analysis Of Nad(P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel Jan 2008

Computational Modeling Of Oxidative Stress: An Analysis Of Nad(P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel

Inquiry: The University of Arkansas Undergraduate Research Journal

Nitric oxide (NO) is inactivated in the human body when exposed to superoxide (02-). This reaction forms peroxynitrite (ONOO). Superoxide is produced in the cardiac system by several mechanisms, including NAD(P)H oxidase. Superoxide dismutase (SOD) breaks down superoxide into oxygen and hydrogen peroxide. This prevents superoxide from reacting with nitric oxide and allows normal function to take place. Superoxide and peroxynitrite are main contributors to vascular disease in the human body, in particular hypertension.