Biomedical Engineering and Bioengineering Commons^™

Effect Of Extracellular Matrix (Ecm) Protein Micropatterns On The Behavior Of Human Neuroblastoma Cells, Ishwari Poudel

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Recent advances in patterning techniques and emerging surface microtechnologies have allowed cell micropatterning to control spatial location of the cells on a surface as well as cell shape, attachment area, and number of contacting neighbor cells. These parameters play important roles in cell cellular behaviors. Cell micropatterning has thus become one of the most important strategies for biomedical applications, such as, tissue engineering, diagnostic immunoassays, lab-on-chip devices, bio-sensing, etc., and cell biology studies as well. For neuronal cells, there have been attempts to distribute neuronal cells on specific patterns to control cell-to-cell interaction. However, there have been very limited understanding …

Studies On Power Hop Using A Nonlinear Model Of An Agricultural Tractor, Adam B. Flaugh

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

Power hop is an unstable dynamic phenomenon that is observed on agricultural tractors operating at field working speeds under typical draft loads. This dynamic instability can be identified as a bounce motion preceded by an increasing oscillation in either the pitch or bounce modes. A definite and comprehensive correction or prevention strategy for the control of power hop does not exist. In this work a linear and a nonlinear model of an agricultural tractor were developed. The method of multiple time scales has been employed in the analysis of the nonlinear model. Numerical results have been obtained using Mathematica to …

The Economics And Logistics Of The Dual Harvest Of Grain And Biomass In A Single-Pass, Matthew T. Wold

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

Significant interest has developed in using cellulosic resources, especially crop residues, to create biofuels. Collecting these residues in a single-pass of the harvester across the field has the potential to be a low cost option. Two models have been developed; the first characterizes the in-field logistics of single-pass crop residue collection, the second the economics. These models allow the user to easily examine a wide variety of both grain-only and single-pass residue collection harvest cases. A variety of possible residue collection cases have been examined, and their effects both on harvester field capacity and harvest cost compared to grain-only harvest …

A Novel Telecommunications-Based Approach To Mathematical Modeling Of Hiv Infection, Aaron T. Sharp

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

It is well known that biological systems utilize communication in some form, one prolific example of this is the propagation of HIV (Human Immunodeficiency Virus) in the human body. By modeling HIV infection as a communication system, we hope to gain a unique insight into HIV and biological communication systems in general. Such a model would provide researchers a platform for experimenting and simulating various biological communication systems. We have previously developed a layered communication protocol for interpreting biological communication systems using telecommunications paradigms and will apply said model to HIV proliferation. We will also demonstrate the effectiveness of the …

Climate Change Policy Could Make Keystone Xl Obsolete, Adam Liska

Adam Liska Papers

Clearly the Keystone XL pipeline threatens both surface and ground water that sustains the agricultural economy of Nebraska, but the projected profitability of tar sands oil and the pipeline operation are dependent on the future economics of climate change. Three recent scientific studies estimate the total carbon intensity of tar sands-based gasoline from Alberta (from both production and burning of the fuel) at an average of roughly 22 percent higher than U.S. gasoline in 2005, with the range of average carbon intensities for tar sands-gasoline at 16 to 27 percent higher than most other sources.

Extrusion And Alkali Extrusion Of Corn Stover To Improve Enzyme Saccharification, Shujing Zhang

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

Biomass pretreatment constitutes an important part in the whole process of bioethanol production. The main goals of pretreatment include improving cellulose accessibility to enzyme, enhancing sugar yields from hemicellulose, achieving low capital and energy costs, as well as low sugar degradation and low chemical requirements. Extrusion, as a continuous and high throughput pretreatment method, requires much less chemical compared to traditional alkali pretreatment. In this research, twin-screw extrusion was evaluated for its effect with regard to promoting sugar yields from corn stover. Also, the underlying factors contributing to this improvement were examined. It was found that extrusion with no chemicals …

Quantitative Analysis Of The Reaction Between Gliadin And Citric Acid Under Weak Acidic And Weak Alkaline Conditions, Wei Li

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

Gliadin was reacted with citric acid under weak acidic and weak alkaline conditions in both wet and dry states and the reaction mechanism was studied. The low morphological stability in an aqueous environment and inferior mechanical properties have restricted the applications of plant proteins, although these materials possess a unique structure, biocompatibility and biodegradability. Carboxylic acids such as citric acid are inexpensive and nontoxic chemicals and are preferred for crosslinking proteins and cellulose to improve the desired properties of the materials.

In this study, gliadin was chosen as a model of plant proteins to react with citric acid. However, previous …

Zein Nanospheres For Gene Delivery, Mary C. Regier

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

Particulates incorporating DNA provide for protection and sustained release of DNA, and thus are promising candidates for DNA delivery systems. Among the routes of administration for gene delivery, the oral route is perhaps the most appealing as it is associated with patient comfort and compliance and allows for targeting to intestinal targets for therapeutic and vaccination applications. With the goal of realizing the potential of an oral DNA delivery system, zein, a hydrophobic protein from corn that is biocompatible and degraded enzymatically, was investigated. This thesis describes the formulation of zein nanospheres encapsulating DNA by a coacervation technique and their …

Monitoring Of Mesenchymal Based Constructs Using Magnetic Resonance Elastography, Evan T. Curtis

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

Evaluating the functionality of an engineered material lies in the proper characterization of its material and functional properties. In the treatment of musculoskeletal disorders, engineered bone or fat tissue must behave as an adequate replacement else failure of the material could result in discomfort and further surgical procedures. A significant material characteristic that reflects tissue development is the mechanical properties (i.e. shear strength and viscosity). Shear strength and viscosity provide an indication of how efficient the material is in dissipating energy. Energy dissipation occurs naturally in many tissues including fat and can prevent damage to deeper tissues. Many of the …

Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa

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

Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …

A Study On Facility Planning Using Discrete Event Simulation: Case Study Of A Grain Delivery Terminal., Sarah M. Asio

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The application of traditional approaches to the design of efficient facilities can be tedious and time consuming when uncertainty and a number of constraints exist. Queuing models and mathematical programming techniques are not able to capture the complex interaction between resources, the environment and space constraints for dynamic stochastic processes. In the following study discrete event simulation is applied to the facility planning process for a grain delivery terminal. The discrete event simulation approach has been applied to studies such as capacity planning and facility layout for a gasoline station and evaluating the resource requirements for a manufacturing facility. To …

Review Of Gasoline, Diesel, And Ethanol Biofuels From Grasses And Plants, By Ram B. Gupta And Ayhan Demirbas., Adam J. Liska

Biological Systems Engineering: Papers and Publications

A new book on the production of biofuels by Gupta and Demirbas provides technical insight into the conversion processes that could provide a range of domestic fuels from plant materials to substitute for foreign oil. It focuses primarily on conversion processes for production of cellulosic ethanol, Fischer-Tropsch diesel, pyrolysis bio-oil, and hydrothermal biocrude from biomass resources, as well as "first-generation" grain ethanol and biodiesel from vegetable oil. In addition to a detailed summary of these chemical processes, the book provides a briefer treatment of related matters such as biofuel policy, economics, and environmental issues.

Analysis Of Site-Specific Adjustment Applied To On-The-Go Soil Sensing Data For Agronomic Use, Allison K. Jonjak

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

Successful variable-rate applications of agricultural inputs such as lime rely on the quality of input data. Systematic grid soil sampling is the most common method used for creating variable rate prescription maps. The insufficient number of point measurements usually obtained using this method has been primarily responsible for the typical inaccuracies seen in lime prescription maps. To increase sampling density, on-the-go sensing technology was developed for the mapping of soil pH and other relevant attributes. In this study, five fields in eastern Nebraska were mapped using both on-thego sensing technology and systematic grid sampling. Ten calibration points per field were …

Nutrient Runoff Following Manure Application, Chance Thayer

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

A field study was completed to measure the effects of varying flow rate on nutrient transport following the application of varying amounts of beef cattle manure to plots containing either no-residue or a wheat residue cover. Beef cattle manure was applied and incorporated into the soil in May 2010 to meet zero, one, two, four or eight year corn phosphorus requirements. Simulated rainfall events were applied in June and July 2010. The presence of a crop residue cover significantly increased the transport of dissolved phosphorus, total phosphorus, NO₃-N, NH₄-N, and total nitrogen in runoff but decreased …

Characterization Of Potential Health Promoting Lipids In The Co-Products Of De-Flossed Milkweed, Vicki Schlegel, Richard Zbasnik, Tammy Gries, Bo Hyun Lee, Timothy Carr, Ji-Young Lee, Curtis Weller, Susan Cuppett

Biological Systems Engineering: Papers and Publications

The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefiting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis …

Gas Embolic Factors In Cardiovascular Health, Eric L. Cutler

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

Gas emboli are a clinical issue often encountered in the space exploration, marine construction, and medical fields. Individuals involved with these disciplines will often have asympomatic gas emboli circulating throughout their bodies on a regular basis. A study into the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis in humans is thus presented. This research utilized a custom built cardiovascular flow simulator and accompanying data acquisition system to experimentally determine the influence of gas emboli under varied circumstances on the mean wall shear stress of a tube in-vitro. A directly inverse relationship between gas embolus presence in …

Ultrasonic And Stereo-Optical Characterization Techniques For Applications In Mechanical Testing, Jonathan M. Hein

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

This thesis considers methods developed based on ultrasonic reflections from interfaces and stereo-optical surface strain measurements to study the mechanical characterization of materials and bodies. The ultrasonic method is used to characterize wave speed and attenuation for highly attenuating samples. The stereo-optical strain measurements are used to characterize the effects of genes on mechanical properties of bone, and the dynamic characterization of blast waves in the UNL Shock Wave Trauma Mechanics facility.

A method is described and developed for characterizing the wave speed and attenuation spectrums from reflected waves from the contact surface with an unknown material. The method is …

Life Cycle Assessment Of Greenhouse Gas Emissions From Ethanol And Biopolymers, Adam J. Liska, Xiao Xue Fang

Adam Liska Papers

Conclusions

• Regulatory LCA is not likely to be used for non‐fuel chemicals alone in the near future

• Significant GHG emission credits for corn‐ethanol can be obtained by using only roughly 6‐9% of initial starch for production of biopolymers based on previous LCA theory

• Pay close attention to values in calculating credits per kg—these have to stand up in litigation to ensure the credit

• Credits are proportional to the mass of polymer produced

• Many theoretical issues are uncertain and credits will only be determined in conjunction with EPA

• Indirect emissions are uncertain and are a …

Bacterial Killing By Dry Metallic Copper Surfaces, Christophe Espírito Santo, Ee Wen Lam, Christian Elowsky, Davide Quaranta, Dylan W. Domaille, Christopher J. Chang, Gregor Grass

Nebraska Center for Biotechnology: Faculty and Staff Publications

Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of …

Fus Transgenic Rats Develop The Phenotypes Of Amyotrophic Lateral Sclerosis And Frontotemporal Lobar Degeneration, Cao Huang, Hongxia Zhou, Jianbin Tong, Han Chen, Yong-Jian Liu, Dian Wang, Xiaotao Wei, Xugang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fused in Sarcoma (FUS) proteinopathy is a feature of frontotemporal lobar dementia (FTLD), and mutation of the fus gene segregates with FTLD and amyotrophic lateral sclerosis (ALS). To study the consequences of mutation in the fus gene, we created transgenic rats expressing the human fus gene with or without mutation. Overexpression of a mutant (R521C substitution), but not normal, human FUS induced progressive paralysis resembling ALS. Mutant FUS transgenic rats developed progressive paralysis secondary to degeneration of motor axons and displayed a substantial loss of neurons in the cortex and hippocampus. This neuronal loss was accompanied by ubiquitin aggregation and …

Effect Of Distillers Grains Moisture And Inclusion Level In Livestock Diets On Greenhouse Gas Emissions In The Corn-Ethanol-Livestock Life Cycle, Virgil R. Bremer, Andrea K. Watson, Adam J. Liska, Galen Erickson, Kenneth Cassman, Kathryn J. Hanford, Terry Klopfenstein

Adam Liska Papers

A model was previously developed (Biofuel Energy Systems Simulator; www. bess.unl.edu) to predict greenhouse gas (GHG) emissions and net energy yield when ethanol is produced from corn. The model also predicts feedlot cattle, dairy cattle, and swine performance and feed replacement value of ethanol coproducts. Updated equations that predict performance of feedlot cattle fed 0 to 40% of dietary DM as corn wet (WDGS), modified (MDGS), or dry (DDGS) distillers grains plus solubles replacing dry-rolled and high-moisture corn were developed and incorporated into the model. Equations were derived from pen-level performance for 20 finishing studies evaluating WDGS, 4 evaluating MDGS, …

Energy And Climate Implications For Agricultural Nutrient Use Efficiency, Adam J. Liska, Richard K. Perrin

Adam Liska Papers

Energy and climate change are beginning to dominate the global political agenda and will drive policy formation that will shape the future of agriculture. Energy issues threaten national security and economic stability, as well as access to low-cost nutrient inputs for agriculture. Climate change has the potential to cause serious disruption to agricultural productivity. Paradoxically, nutrient use in agriculture to increase crop yields has the potential to negatively impact climate. This chapter will discuss recent and future energy and climate trends, the relationships between agricultural nutrient use efficiency and biofuels, and how global land limitations will shape agriculture in the …

Using Thermally Coupled Reactive Distillation Columns In Biodiesel Production, Nghi Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Production of ethyl dodecanoate (biodiesel) using lauric acid and methanol with a solid acid catalyst of sulfated zirconia is studied by using two distillation sequences. In the first sequence, the methanol recovery column follows the reactive distillation column. In the second sequence, the reactive distillation and methanol recovery columns are thermally coupled. Thermally coupled distillation sequences may consume less energy by allowing interconnecting vapor and liquid streams between the two columns to elminate reboiler or condenser or both. Here we study the thermally coupled side-stripper reactive distillation and eliminate the condenser of the reactive distillation column. Both the sequences are …

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

Biological Systems Engineering: Papers and Publications

Phosphorus (P) loading to streams can occur by both surface runoff and subsurface transport, with subsurface P transport often assumed negligible. Groundwater P concentrations in alluvial aquifers can be significant, especially in preferential flow paths (PFPs). The objectives of this research were to quantify subsurface P transport rates at two sites in northeastern Oklahoma and to compare them with surface runoff P transport rates derived from a hydrologic model, the Pasture Phosphorus Management Calculator (PPM Plus). Ozark ecoregion study sites were adjacent to the Barren Fork Creek and Honey Creek in northeastern OK, USA. Each site, instrumented with 24 observation …

Evaluation Of Soil Salinity Leaching Requirement Guidelines, John Letey, Glenn J. Hoffman, Jan W. Hopmans, Stephen R. Grattan, Donald Louis Suarez, Dennis L. Corwin, Jim D. Oster, Laosheng Wu, Christopher Amrhein

Biological Systems Engineering: Papers and Publications

Water for irrigation is a major limitation to agricultural production in many parts of the world. Use of waters with elevated levels of salinity is one likely option to meet the supply of increased demands. The sources of these waters include drainage water generated by irrigated agriculture, municipal wastewater, and poor quality groundwater. Soil salinity leaching requirements that were established several decades ago were based on steady-state conditions. Recently transient-state models have been developed that potentially can more correctly predict the dynamics of the chemical–physical–biological interactions in an agricultural system. The University of California Center for Water Resources appointed a …

Comparative Manufacture And Cell-Based Delivery Of Antiretroviral Nanoformulations, Shantanu Balkundi, Ari S. Nowacek, Ram S. Veerubhotla, Han Chen, Andrea Martinez-Skinner, Upal Roy, R. Lee Mosley, Georgette Kanmogne, Xinming Liu, Alexander V. Kabanov, Tatiana Bronich, Joellyn Mcmillan, Howard E. Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility.

Biocomposites Developed Using Water-Plasticized Wheat Gluten As Matrix And Jute Fibers As Reinforcement, Narendra Reddy, Yiqi Yang

Biological Systems Engineering: Papers and Publications

Biocomposites developed from wheat gluten using water without any chemicals as plasticizer and jute fibers as reinforcement have much better flexural and tensile properties than similar polypropylene composites reinforced with jute fibers. Wheat gluten is an inexpensive and abundant co-product derived from renewable resources and is biodegradable but non-thermoplastic. Previous attempts at developing biocomposites from wheat gluten have used plasticizers such as glycerol or chemical modifications to make gluten thermoplastic. However, plasticizers have a considerably negative effect on the mechanical properties of the composites and chemical modifications make wheat gluten less biodegradable, expensive and/or environmentally unfriendly. In the research reported, …

Spatial Variability Of Field Machinery Use And Efficiency, Viacheslav I. Adamchuk, Robert Grisso, Michael F. Kocher

Biological Systems Engineering: Papers and Publications

In site-specific crop management, It is a common practice to log the geographic coordinates of agricultural machinery measured using a global satellite navigation system (GNSS) such as the global positioning system (GPS). Yield, fertilizer application, and seed placement maps provide useful data for making agronomic decisions. However, the travel path itself reveals valuable information about machinery performance. Often, during field operations, odd field shapes, obstacles, or contour farming will require operators to increase the complexity of the machinery maneuvering. This usually reduces field efficiency. This chapter presents a methodology to parameterize the spatially variable characteristics of traffic patterns, and to …

Completely Biodegradable Soyprotein–Jute Biocomposites Developed Using Water Without Any Chemicals As Plasticizer, Narendra Reddy, Yiqi Yang

Biological Systems Engineering: Papers and Publications

Soyprotein–jute fiber composites developed using water without any chemicals as the plasticizer show much better flexural and tensile properties than polypropylene–jute composites. Co-products of soybean processing such as soy oil, soyprotein concentrate and soy protein isolates are inexpensive, abundantly available and are renewable resources that have been extensively studied as potential matrix materials to develop biodegradable composites. However, previous attempts on developing soy-based composites have either chemically modified the co-products or used plasticizers such as glycerol. Chemical modifications make the composites expensive and less environmentally friendly and plasticizers decrease the properties of the composites. In this research, soyprotein composites reinforced …

Ethanol Yields And Cell Wall Properties In Divergently Bred Switchgrass Genotypes, Gautam Sarath, Bruce S. Dien, Aaron J. Saathoff, Kenneth P. Vogel, Robert B. Mitchell, Han Chen

Biological Systems Engineering: Papers and Publications

Genetic modification of herbaceous plant cell walls to increase biofuels yields is a primary bioenergy research goal. Using two switchgrass populations developed by divergent breeding for ruminant digestibility, the contributions of several wall-related factors to ethanol yields was evaluated. Field grown low lignin plants significantly out yielded high lignin plants for conversion to ethanol by 39.1% and extraction of xylans by 12%. However, across all plants analyzed, greater than 50% of the variation in ethanol yields was attributable to changes in tissue and cell wall architecture, and responses of stem biomass to diluteacid pretreatment. Although lignin levels were lower in …