Other Civil and Environmental Engineering Commons^™

Robust And Flexible Films From 100% Starch Cross-Linked By Biobased Disaccharide Derivative, Helan Xu, Hazal Canisag, Bingnan Mu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In this research, oxidized sucrose, a novel aldehyde-based green cross-linker, endowed starch films with substantial improvement in both tensile strength and elongation, whereas many other cross-linkers did not. Starch films are usually weak, brittle, and highly moisture sensitive, and thus have restricted industrial applications. Cross-linking is one of the most common methods to tackle these problems. However, most of the available cross-linkers are either toxic, expensive, or with low cross-linking efficiencies. Oxidized sucrose is a green cross-linker with multiple aldehyde groups per molecule to cross-link starch molecules via forming hemiacetals/acetals. The starch films cross-linked with oxidized sucrose had tensile strength …

Bionanotechnology And The Future Of Glioma, Peter A. Chiarelli, Forrest M. Kievit, Miqin Zhang, Richard G. Ellenbogen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Designer nanoscaled materials have the potential to revolutionize diagnosis and treatment for glioma. This review summarizes current progress in nanoparticle‑based therapies for glioma treatment including targeting, drug delivery, gene delivery, and direct tumor ablation. Preclinical and current human clinical trials are discussed. Although progress in the field has been significant over the past decade, many successful strategies demonstrated in the laboratory have yet to be implemented in human clinical trials. Looking forward, we provide examples of combined treatment strategies, which harness the potential for nanoparticles to interact with their biochemical environment, and simultaneously with externally applied photons or magnetic fields. …

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

Department of Agricultural and Biological Systems Engineering: Faculty Publications

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

Surface Energy Balance, Evapotranspiration, And Surface Coefficients During Non-Growing Season In A Maize-Soybean Cropping System, Lameck O. Odhiambo, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Surface energy balance components, including actual evapotranspiration (ET), were measured in a reducedtill maize-soybean field in south central Nebraska during three consecutive non-growing seasons (2006/2007, 2007/2008, and 2008/2009). The relative fractions of the energy balance components were compared across the non-growing seasons, and surface coefficients (K_c) were determined as a ratio of measured ET to estimated alfalfa (ET_r) and grass (ET_o) reference ET (ET_ref). The non-growing season following a maize crop had 25% to 35% more field surface covered with crop residue as compared to the non-growing seasons following soybean crops. Net …

Control System Development And Response Analysis Of An Electronically Actuated Variable-Orifice Nozzle For Agricultural Pesticide Applications, Joe D. Luck, S. A. Shearer, M. P. Sama, Santosh Pitla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this research project was to further the development of an electromechanically controlled variable-orifice nozzle by creating an electronic control system and then evaluating that system based on step and ramp inputs. The control system was developed in a programming environment that combined an electronic data acquisition system and actuator with pressure and flow sensors. A proportional, variable-gain (based on system pressure) control system was developed to adjust nozzle flow rates to meet target application rates. The constraints were to achieve settling time of less than 1.0 s, overshoot of less than 10% of maximum flow (or minimum …

Flow, Spray Pattern, And Droplet Spectra Characteristics Of An Electronically Actuated Variable-Orifice Nozzle, Joe D. Luck, Santosh Pitla, M. P. Sama, S. A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to develop and evaluate the flow rate, spray pattern, and droplet spectra characteristics of an actively controlled variable-orifice nozzle at constant carrier pressures. A commercially available variable- orifice nozzle (VariTarget) was modified to allow for direct electromechanical control of the metering stem. The modified system was tested at five carrier pressures ranging from 138 to 414 kPa and five metering stem (and thus orifice) positions. The metering stem position range was chosen because it provided a linear response in flow rate at each carrier pressure. Flow rate testing indicated a turndown ratio of 2.4:1 …

The Effect Of Water Temperature On In-Stream Sediment Concentration And Transport Rate, Jennie Tyrrell

Dissertations, Master's Theses and Master's Reports

Global climate change may result in rising temperatures. As a result, ecological health and the human use of rivers may be impacted. The hydrologic cycle, watershed hydrology, and in-stream hydraulics are dynamic systems, influenced by human activities, natural events, and climate. Although known drivers like precipitation and stream velocity govern sediment processes, the effect of water temperature on sediment transport remains unclear. In-stream sediment movement could lead to blocked harbors, flooding, and degradation of vulnerable fish habitat. To better understand how fluctuations in water temperature affect sediment dynamics, six transport models were analyzed on the Niobrara River, with water temperatures …

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

Department of Agricultural and Biological Systems Engineering: Faculty Publications

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

Roundabout Maintenance Flipbook, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This flipbook is a summary of the work pub­lished in the Roundabout Maintenance Manual by Indiana LTAP. This information was collected through a series of interviews with city engi­neers, public works directors, and street commis­sioners experienced in roundabout maintenance. It serves as a model to guide work crews in correct maintenance procedures.

Roundabout Maintenance Manual, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This maintenance manual serves as an additional resource for communities who have imple­mented roundabouts or are considering them. There are a few other published guides, such as the NCHRP Report 672, Roundabouts: An Informational Guide, and the Wisconsin DOT Facilities Develop­ment Manual. However, the information covered in these guides is very broad. This manual provides specific information regarding roundabout maintenance.

Robust Estimates Of Soil Moisture And Latent Heat Flux Coupling Strength Obtained From Triple Collocation, Wade T. Crow, Fangni Lei, Christopher R. Hain, Martha C. Anderson, Russell L. Scott, David P. Billesbach, Timothy Arkebauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Land surface models (LSMs) are often applied to predict the one-way coupling strength between surface soil moisture (SM) and latent heat (LH) flux. However, the ability of LSMs to accurately represent such coupling has not been adequately established. Likewise, the estimation of SM/LH coupling strength using ground-based observational data is potentially compromised by the impact of independent SM and LH measurements errors. Here we apply a new statistical technique to acquire estimates of one-way SM/LH coupling strength which are nonbiased in the presence of random error using a triple collocation approach based on leveraging the simultaneous availability of independent SM …

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

Department of Agricultural and Biological Systems Engineering: Faculty Publications

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

Identifying Intracellular Pdna Losses From A Model Of Nonviral Gene Delivery, Timothy Michael Martin, Beata Joanna Wysocki, Tadeusz Antoni Wysocki, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nonviral gene delivery systems are a type of nanocommunication system that transmit plasmid packets (i.e., pDNA packets) that are programmed at the nanoscale to biological systems at the microscopic cellular level. This engineered nanocommunication system suffers large pDNA losses during transmission of the genetically encoded information, preventing its use in biotechnological and medical applications. The pDNA losses largely remain uncharacterized, and the ramifications of reducing pDNA loss from newly designed gene delivery systems remain difficult to predict. Here, the pDNA losses during primary and secondary transmission chains were identified utilizing a MATLAB model employing queuing theory simulating delivery of pEGFPLuc …

Narrow Grass Hedges Reduce Tylosin And Associated Antimicrobial Resistance Genes In Agricultural Runoff, Bhavneet Soni, Shannon L. Bartelt-Hunt, Daniel D. Snow, John E. Gilley, Bryan Woodbury, David B. Marx, Xu Li

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobials and ARGs in runoff after land application of swine manure slurry. Plot-scale rainfall simulation tests were conducted on 0.75 m by 4.0 m plots designed to test three treatment factors: manure amendment (control plots receiving no manure vs. amended plots receiving manure based on 3 times N requirement), NGH (plots with a NGH vs. plots without a NGH), and rainfall …

Vulnerability Of Crops And Native Grasses To Summer Drying In The U.S. Southern Great Plains, Naama Raz-Yaseef, Dave P. Billesbach, Marc L. Fischer, Sebastien C. Biraud, Stacey A. Gunter, James A. Bradford, Margaret S. Torn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Southern Great Plains are characterized by a fine-scale mixture of different land-cover types, predominantly winter-wheat and grazed pasture, with relatively small areas of other crops, native prairie, and switchgrass. Recent droughts and predictions of increased drought in the Southern Great Plains, especially during the summer months, raise concern for these ecosystems. We measured ecosystem carbon and water fluxes with eddy-covariance systems over cultivated cropland for 10 years, and over lightly grazed prairie and new switchgrass fields for 2 years each. Growing-season precipitation showed the strongest control over net carbon uptake for all ecosystems, but with a variable effect: grasses …

A Sustainable Slashing Industry Using Biodegradable Sizes From Modified Soy Protein To Replace Petro-Based Poly(Vinyl Alcohol), Yi Zhao, Yuzhu Zhao, Helan Xu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, …

Sustainable And Hydrolysis-Free Dyeing Process For Polylactic Acid Using Nonaqueous Medium, Suxin Xu, Jiangang Chen, Bijia Wang, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A sustainable and hydrolysis-free dyeing process was developed for polylactic acid (PLA) fibers. PLA is a biobased alternative to petroleum based polyethylene terephthalate (PET), which is the most widely used textile fiber. However, the hydrolytic degradation of PLA fibers under the conventional aqueous dyeing conditions limited its applications in textile industry. A new solvent dyeing process was developed using liquid paraffin as a nonaqueous dyeing medium. High quality dyed PLA fabrics were obtained without consuming water and auxiliaries. Minimal strength loss of dyed fibers was achieved by postheat setting treatment. The 3R principle (reduce, reuse, and recycle) was implemented to …

Chitosan-Alginate Scaffold Cell Culture System And Related Methods, Miqin Zhang, Forrest Kievit, Matthew Chi-Hang Leung, Stephen Florczyk

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Methods for culturing cancer cells in vitro using a three dimensional scaffold, scaffolds that include the cultured cancer cells, and methods for using the cultured cancer cells and the scaffolds that include the cultured cancer cells in anticancer therapeutic drug development.

Nanoparticle Mediated Silencing Of Dna Repair Sensitizes Pediatric Brain Tumor Cells To Y-Irradiation, Forrest M. Kievit, Zachary R. Stephen, Kui Wang, Christopher J. Dayringer, Jonathan G. Sham, Richard G. Ellenbogen, John R. Silber, Miqin Zhang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Medulloblastoma (MB) and ependymoma (EP) are the most common pediatric brain tumors, afflicting 3000 children annually. Radiotherapy (RT) is an integral component in the treatment of these tumors; however, the improvement in survival is often accompanied by radiation-induced adverse developmental and psychosocial sequelae. Therefore, there is an urgent need to develop strategies that can increase the sensitivity of brain tumors cells to RT while sparing adjacent healthy brain tissue. Apurinic endonuclease 1 (Ape1), an enzyme in the base excision repair pathway, has been implicated in radiation resistance in cancer. Pharmacological and specificity limitations inherent to small molecule inhibitors of Ape1 …

Underwater Sound Transmission Through Arrays Of Disk Cavities In A Soft Elastic Medium, David C. Calvo, Abel L. Thangawng, Christopher N. Layman Jr., Riccardo Casalini, Shadi F. Othman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Scattering from a cavity in a soft elastic medium, such as silicone rubber, resembles scattering from an underwater bubble in that low-frequency monopole resonance is obtainable in both cases. Arrays of cavities can therefore be used to reduce underwater sound transmission using thin layers and low void fractions. This article examines the role of cavity shape by microfabricating arrays of disk-shaped air cavities into single and multiple layers of polydimethylsiloxane. Comparison is made with the case of equivalent volume cylinders which approximate spheres. Measurements of ultrasonic underwater sound transmission are compared with finite element modeling predictions. The disks provide a …