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2017

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Articles 61 - 90 of 166

Full-Text Articles in Bioresource and Agricultural Engineering

A Tunable, Three-Dimensional In Vitro Culture Model Of Growth Plate Cartilage Using Alginate Hydrogel Scaffolds, Alek G. Erickson, Taylor D. Laughlin, Sarah Romereim, Catherine Sargus-Patino, Angela K. Pannier, Andrew T. Dudley May 2017

A Tunable, Three-Dimensional In Vitro Culture Model Of Growth Plate Cartilage Using Alginate Hydrogel Scaffolds, Alek G. Erickson, Taylor D. Laughlin, Sarah Romereim, Catherine Sargus-Patino, Angela K. Pannier, Andrew T. Dudley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Defining the final size and geometry of engineered tissues through precise control of the scalar and vector components of tissue growth is a necessary benchmark for regenerative medicine, but it has proved to be a significant challenge for tissue engineers. The growth plate cartilage that promotes elongation of the long bones is a good model system for studying morphogenetic mechanisms because cartilage is composed of a single cell type, the chondrocyte; chondrocytes are readily maintained in culture; and growth trajectory is predominately in a single vector. In this cartilage, growth is generated via a differentiation program that is spatially and …


Two-Step Sequential Pretreatment For The Enhanced Enzymatic Hydrolysis Of Coffee Spent Waste, Rajeev Ravindran, Swarna Jaiswal, Nissreen Abu-Ghannam, Amit Jaiswal May 2017

Two-Step Sequential Pretreatment For The Enhanced Enzymatic Hydrolysis Of Coffee Spent Waste, Rajeev Ravindran, Swarna Jaiswal, Nissreen Abu-Ghannam, Amit Jaiswal

Articles

In the present study, eight different pretreatments of varying nature (physical, chemical and physico-chemical) followed by a sequential, combinatorial pretreatment strategy was applied to spent coffee waste to attain maximum sugar yield. Pretreated samples were analysed for total reducing sugar, individual sugars and generation of inhibitory compounds such as furfural and hydroxymethyl furfural (HMF) which can hinder microbial growth and enzyme activity. Native spent coffee waste was high in hemicellulose content. Galactose was found to be the predominant sugar in spent coffee waste. Results showed that sequential pretreatment yielded 350.12mg of reducing sugar/g of substrate, which was 1.7-fold higher than …


Supraspinatus Tendon Micromorphology In Individuals With Subacromial Pain Syndrome, Federico Pozzi, Amee L. Seitz, Hillary A. Plummer, Kira Chow, Gregory R. Bashford, Lori A. Michener May 2017

Supraspinatus Tendon Micromorphology In Individuals With Subacromial Pain Syndrome, Federico Pozzi, Amee L. Seitz, Hillary A. Plummer, Kira Chow, Gregory R. Bashford, Lori A. Michener

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Study Design: Cross-sectional cohort. Introduction: Tendon collagen organization can be estimated by peak spatial frequency radius (PSFR) on ultrasound images. Characterizing PSFR can define the contribution of collagen disruption to shoulder symptoms.

Purpose of the Study: The purpose of this was to characterize the (1) supraspinatus tendon PSFR in participants with sub acromial pain syndrome (SPS) and healthy controls; (2) PSFR between participants grouped on a tendon visual quality score; and (3) relationship between PSFR with patient-reported pain, function, and shoulder strength.

Methods: Participants with SPS (n ¼ 20) and age, sex, and arm-dominance matched healthy controls (n ¼ 20) …


Method For The Production Of Substituted Polysaccharides Via Reactive Extrusion, Milford Hanna, Pratik Bhandari May 2017

Method For The Production Of Substituted Polysaccharides Via Reactive Extrusion, Milford Hanna, Pratik Bhandari

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A reactive extrusion process for the production of substituted polysaccharides, in particular, cellulose acetate, starch acetate, carboxymethyl cellulose, and carboxymethyl starch.

The present application claims the benefit of PCT/ US20111059785 filed on Nov. 8, 2011, which claimed the benefit of U.S. provisional application 611411,521, filed on Nov. 9, 2010, U.S. provisional application 611411,992, filed on Nov. 10, 2010, and U.S. provisional application 611472, 748, filed on Apr. 7, 2011, each of which is which is incorporated herein by reference in its entirety.

The production of substituted polysaccharides such as starch and cellulose acetates and carboxymethylated starches and celluloses have typically …


Genetically Engineered Organisms: Progress Or Poison, Melina Sansi May 2017

Genetically Engineered Organisms: Progress Or Poison, Melina Sansi

Senior Theses

Genetically engineered organisms are a part of almost everything we put into our bodies. More than any other time in history, humans are manipulating plants and organisms on an advanced level. Scientists are able to genetically alter food so that it precisely fills a specific dietary need, or increase crop yields to feed the growing global population expected to reach 9 billion people by the year 2050. Currently 250 million acres worldwide are used to grow genetically modified organisms. Many consumers don’t fully understand the use and impact of genetically engineered organisms for lack of accessible and straightforward information. Federal …


Analysis Of Lid Implementation To Combat Flooding And Erosion At The University Of Arkansas Campus, Madison E. Crowl May 2017

Analysis Of Lid Implementation To Combat Flooding And Erosion At The University Of Arkansas Campus, Madison E. Crowl

Biological and Agricultural Engineering Undergraduate Honors Theses

The city of Fayetteville, Arkansas has experienced rapid urbanization throughout recent years as it continues to grow. Within the city, the University of Arkansas has been constantly expanding, with increased impervious surfaces as more parking lots and facilities are built. This has caused issues including flooding and stream bank erosion, specifically in Mullins Creek, which receives runoff from a large part of campus. A portion of the creek was restored, but there are still downstream issues. Low Impact Development (LID) is a type of green infrastructure that has been shown to decrease runoff and increase infiltration. EPA SWMM, a hydrologic …


Improving Flow Measurement Accuracy Using A Portable Irrigation Turnout Calibration Unit, Stuart Styles, Kyle Feist, Charles M. Burt May 2017

Improving Flow Measurement Accuracy Using A Portable Irrigation Turnout Calibration Unit, Stuart Styles, Kyle Feist, Charles M. Burt

BioResource and Agricultural Engineering

Relatively accurate flow measurement at irrigation district water delivery points is an important component of volumetric billing and equitable service. In California, this has often occurred with conversions to pressurized irrigation systems which commonly include the installation of pipeline flow meters as part of the on-farm system. However, a large portion of irrigation turnouts in the western US continue to operate via gravity and fall into one of the following categories: (a) a metergate, or similar structure was installed without adherence to standard construction requirements or (b) the structure was never intended for flow measurement.

For these and other scenarios, …


Using Electricity Consumption To Estimate Water Volumes Pumped From Wells, Charles M. Burt May 2017

Using Electricity Consumption To Estimate Water Volumes Pumped From Wells, Charles M. Burt

BioResource and Agricultural Engineering

The Sustainable Groundwater Management Act (SGMA) of California has led some organizations to want access to documentation of the volumes of groundwater pumped by individual wells. Many well pumps already have flow meters installed that provide an accurate measurement of both instantaneous flow rate and the cumulative volume pumped. For wells that do not have flow meters, it has been proposed for many years that pumped volumes can be accurately estimated by simply using the total power consumption, measured in kilowatt-hours (kWh).


Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi May 2017

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …


Development Of A One Pass Microwave Heating Technology For Rice Drying And Decontamination, Deandrae Lynette Smith May 2017

Development Of A One Pass Microwave Heating Technology For Rice Drying And Decontamination, Deandrae Lynette Smith

Graduate Theses and Dissertations

An industrial microwave (MW) system operating at 915 MHz frequency was used to dry high moisture content (MC) (23% to 24% wet basis) medium-grain rough rice samples (cv. Jupiter). The rice beds were contained in a modified tray that accommodated up to 9 kg of rice separated by thin fiberglass mesh in 3 kg increments. Each layer of rice was fitted with fiber optic sensors connected to a real time data logger during MW treatments. It was determined that drying rice to a MC of 14% to 16% was feasible with the application of MW specific energy at 600 kJ/kg-grain …


Integrated Life Cycle And Techno-Economic Assessment Of The Conversion Of High Productivity, Low Lipid Algae To Renewable Fuels, Chad R. De Mill May 2017

Integrated Life Cycle And Techno-Economic Assessment Of The Conversion Of High Productivity, Low Lipid Algae To Renewable Fuels, Chad R. De Mill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The production of alternative transportation fuels is imperative to meet future energy demands without contributing to global climate change. Advances in alternative processing techniques that have emerged due to interest in microalgae as a feedstock have led to a variety of potential processing pathways for the production of bio-based fuels. A major hurdle in the algal production process is maintaining a fast and stable algae culture. Monocultures, developed for their high lipid content, suffer from low productivity, are susceptible to crashes and require a constant supply of carbon dioxide to maintain productivity. In an effort to circumvent these obstacles, algal …


Testing Effectiveness Of Aqueous Phases From Struvite And Hydroxyapatite Mineral Precipitation As Algal Nutrient Sources, Aaron Lyons Apr 2017

Testing Effectiveness Of Aqueous Phases From Struvite And Hydroxyapatite Mineral Precipitation As Algal Nutrient Sources, Aaron Lyons

Virginias Collegiate Honors Council Conference

As interest in algal biofuel grows, the need to explore diverse nutrient sources for growing algae becomes apparent. Struvite and Hydroxyapatite (HAP) were precipitated after flash hydrolysis. The leftover aqueous phase (AP) could serve as nutrients source for algae cultivation and the potential reuse of this waste stream is promising. To test this, 12 bottles of Scenedemus sp., four of Struvite, four of HAP, and four control AM-14 synthetic media were cultivated. 10% of the Phosphorus in the synthetic media was replaced with phosphorous from the struvite AP, and 10% of the nitrogen in the synthetic media was replaced …


High Throughput In Vivo Analysis Of Plant Leaf Chemical Properties Using Hyperspectral Imaging, Piyush Pandey, Yufeng Ge, Vincent Stoerger, James C. Schnable Apr 2017

High Throughput In Vivo Analysis Of Plant Leaf Chemical Properties Using Hyperspectral Imaging, Piyush Pandey, Yufeng Ge, Vincent Stoerger, James C. Schnable

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

The possibility of predicting plant leaf chemical properties using hyperspectral images was studied. Sixty maize and 60 soybean plants were used, and two experiments were conducted: one with water limitation and the second with nutrient limitation, with the purpose of creating wide ranges of these chemical properties in plant leaf tissues. A hyperspectral imaging system with a spectral range from 550 to 1700 nm was used to acquire plant images in a high throughput fashion (plants placed on an automated conveyor belt). Leaf chemical properties were measured in the laboratory. Partial least squares regression was implemented on spectral data to …


Energy–Water Reduction And Wastewater Reclamation In A Fluid Milk Processing Facility, Carly Rain Adams, Yulie E. Meneses, Bing Wang, Curtis L. Weller Apr 2017

Energy–Water Reduction And Wastewater Reclamation In A Fluid Milk Processing Facility, Carly Rain Adams, Yulie E. Meneses, Bing Wang, Curtis L. Weller

Department of Food Science and Technology: Dissertations, Theses, and Student Research

The energy-water nexus is the inseparable connection linking water and energy. We are faced with a unique opportunity to co-manage these resources, as conservation of one is directly linked to the conservation of its counterpart. Therefore, immediately facing this critical challenge, will lead to tangible impacts on the water and energy crisis our food system is faced with. Determining the role of water and energy in the food industry has proved to be the starting point for reducing the distance between process productivity and resource efficiency. Therefore, this research focuses on determining opportunities for water-energy optimization and wastewater reduction and …


Investigation Of Petroleum Use In Off-Road Agricultural Machinery And Analysis Of J1939 Controller Area Network (Can) Data For Advanced Machinery Testing, Rodney Rohrer Apr 2017

Investigation Of Petroleum Use In Off-Road Agricultural Machinery And Analysis Of J1939 Controller Area Network (Can) Data For Advanced Machinery Testing, Rodney Rohrer

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

Nearly all modern off-road agricultural machinery are powered by petroleum, primarily diesel fuel. Equipment manufacturers work to improve fuel efficiency of their equipment to provide better value to their customers. Benefits of reducing petroleum use include lower operating costs, improved operational efficiency, improved energy security, and environmental benefits. Agricultural tractor testing focuses primarily on characterizing maximum performance but there is a need for advanced test procedures to better measure fuel efficiency for load cases representative of in-field operations. This would help farmers make better equipment purchasing and utilization decisions and help manufacturers quantify efficiency improvements; ultimately driving continued progress toward …


Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde Apr 2017

Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde

Electronic Theses and Dissertations

Biomass processing for industrial products and biofuels has gained an increasing presence as society looks to using sustainable resources for manufacturing and renewable fuels for energy. However, these sustainably produced materials and products cannot gain a competitive edge because of the manufacturing expenses that are a result of high process temperatures and pressures. In order to lower these costs, theoretical modeling has described a value-added co-product strategy as one of the best ways to combat high bioprocessing prices. Biomass has been shown to make effective carbons for energy storage devices such as supercapacitors and batteries. These carbons, with the right …


Oral History Conversation With Lydell Aaron (Beartha), Alexander Z. Bulkin, Kari Schattinger, Kate L. Gardner, Charbel Mouannes, Danielle Silvaggio Mar 2017

Oral History Conversation With Lydell Aaron (Beartha), Alexander Z. Bulkin, Kari Schattinger, Kate L. Gardner, Charbel Mouannes, Danielle Silvaggio

Philosophy: All Student Work

Oral History Interview conducted with Lydell Aaron. He founded Beartha Systems which builds scalable and smart systems that harness energy and resources for small communities.


Using The Vehicle Routing Problem To Reduce Field Completion Times With Multiple Machines, Hasan Seyyedhasani, Joseph S. Dvorak Mar 2017

Using The Vehicle Routing Problem To Reduce Field Completion Times With Multiple Machines, Hasan Seyyedhasani, Joseph S. Dvorak

Biosystems and Agricultural Engineering Faculty Publications

The Vehicle Routing Problem (VRP) is a powerful tool used to express many logistics problems, yet unlike other vehicle routing challenges, agricultural field work consists of machine paths that completely cover a field. In this work, the allocation and ordering of field paths among a number of available machines has been transformed into a VRP that enables optimization of completion time for the entire field. A basic heuristic algorithm (a modified form of the common Clarke-Wright algorithm) and a meta-heuristic algorithm, Tabu Search, were employed for optimization. Both techniques were evaluated through computer simulations in two fields: a hypothetical basic …


Influence Of Supply-Channel Velocity On Farm Delivery Meter Gate Flow Measurement, Daniel J. Howes, Charles M. Burt, John M. Thorburn Feb 2017

Influence Of Supply-Channel Velocity On Farm Delivery Meter Gate Flow Measurement, Daniel J. Howes, Charles M. Burt, John M. Thorburn

BioResource and Agricultural Engineering

The work presented here is an extension of previous papers that updated the calibration of round (Armco-type) meter gates (three sizes: 0.30, 0.46, and 0.61 m), developed ratings for rectangular gates (two sizes: 0.46 and 0.61 m) on round pipes, and examined errors and uncertainty related to using these devices for water discharge measurement. Previous works examined gate discharge ratings under low supply-channel flow velocity perpendicular to the gate discharge pipeline. Here, additional testing was conducted to test the hypothesis that higher velocities in the supply channel would show decreased meter gate flow compared to the low-velocity ratings, but that …


Contemporary And Future Characteristics Of Precipitation Indices In The Kentucky River Basin, Somsubhra Chattopadhyay, Dwayne R. Edwards, Yao Yu Feb 2017

Contemporary And Future Characteristics Of Precipitation Indices In The Kentucky River Basin, Somsubhra Chattopadhyay, Dwayne R. Edwards, Yao Yu

Biosystems and Agricultural Engineering Faculty Publications

Climatic variability can lead to large-scale alterations in the hydrologic cycle, some of which can be characterized in terms of indices involving precipitation depth, duration and frequency. This study evaluated the spatiotemporal behavior of precipitation indices over the Kentucky River watershed for both the baseline period of 1986–2015 and late-century time frame of 2070–2099. Historical precipitation data were collected from 16 weather stations in the watershed, while future rainfall time-series were obtained from an ensemble of 10 Coupled Model Intercomparison Project Phase 5 (CMIP5) global circulation models under two future emission pathways: Representative Concentration Pathways (RCP) 4.5 and 8.5. Annual …


Remediating 1,4-Dioxane-Contaminated Water With Slow-Release Persulfate And Zerovalent Iron, Ann Kambhu, Megan Gren, Wei Tang, Steve D. Comfort, Clifford Harris Feb 2017

Remediating 1,4-Dioxane-Contaminated Water With Slow-Release Persulfate And Zerovalent Iron, Ann Kambhu, Megan Gren, Wei Tang, Steve D. Comfort, Clifford Harris

Nebraska Water Center: Faculty Publications

1,4-dioxane is an emerging contaminant that was used as a corrosion inhibitor with chlorinated solvents. Metal-activated persulfate can degrade dioxane but reaction kinetics have typically been characterized by a rapid decrease during the first 30 min followed by either a slower decrease or no further change (i.e., plateau). Our objective was to identify the factors responsible for this plateau and then determine if slow-release formulations of sodium persulfate and Fe0 could provide a more sustainable degradation treatment. We accomplished this by conducting batch experiments where Fe0-activated persulfate was used to treat dioxane. Treatment variables included the timing …


Center Pivot Irrigation Handbook (Ec3017), Derrel Martin, William Kranz, Tyler Smith, Suat Irmak, Charles Burr, Ron Yoder Feb 2017

Center Pivot Irrigation Handbook (Ec3017), Derrel Martin, William Kranz, Tyler Smith, Suat Irmak, Charles Burr, Ron Yoder

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Center pivot irrigation has been the most rapidly expanding form of irrigation in the Central Great Plains and across the United States. The amount of land irrigated with sprinkler, gravity and drip or trickle systems was determined for all states in the USA in the Farm and Ranch Irrigation Survey1 by the USDA in 2012. Results of the survey for the Great Plains States shows that approximately 85% of the land in Nebraska is irrigated with center pivots and that very little land was irrigated with drip systems in 2012 (Figure 1). The percentage of land irrigated with sprinklers in …


Tissue Decellularization Methods, Christine E. Schmidt, Rebecca A. Wachs, Robert Chase Cornelison Jan 2017

Tissue Decellularization Methods, Christine E. Schmidt, Rebecca A. Wachs, Robert Chase Cornelison

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Provided herein are methods of producing an acellular tissue product wherein the method can include the step of inducing apoptosis and washing the tissue after induction of apoptosis with a tonic solution. Also provided herein are acellular tissue products produced by the methods provided herein and methods of administering the acellular tissue products to a subject in need thereof.


The Irreversible Momentum Of Clean Energy, Barack Obama Jan 2017

The Irreversible Momentum Of Clean Energy, Barack Obama

United States Department of Energy: Publications

The release of carbon dioxide (CO2) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean. Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations. Although our understanding of the impacts of climate change is increasingly and disturbingly clear, there is still debate about the proper course for U.S. policy—a debate that is very much on display …


2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman Jan 2017

2017 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain high quality water and encourage or execute activities to improve poor water quality. Monitoring is done on nearly 17,000 miles of flowing rivers and streams, more than 134,000 acres of surface water in lakes and reservoirs, as well as the vast storage of groundwater in Nebraska’s aquifers.


Correction: Messer, T.L.; Burchell, M.R.; Birgand, F. Comparison Of Four Nitrate Removal Kinetic Models In Two Distinct Wetland Restoration Mesocosm Systems. Water 2017, 9, 517, Tiffany L. Messer, Michael R. Burchell, François Birgand Jan 2017

Correction: Messer, T.L.; Burchell, M.R.; Birgand, F. Comparison Of Four Nitrate Removal Kinetic Models In Two Distinct Wetland Restoration Mesocosm Systems. Water 2017, 9, 517, Tiffany L. Messer, Michael R. Burchell, François Birgand

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The authors wish to make the following corrections to this paper [1]:

(1): The author name “François Bírgand” should be François Birgand.

(2): Reference 38 should be the following:

Birgand, F.; Aveni-Deforge, K.; Smith, B.; Maxwell, B.M.; Horstman, M.; Gerling, A.B.; Carey, C.C. First report of a novel multiplexer pumping system coupled to a water quality probe to collect high temporal frequency in situ water chemistry measurements at multiple sites. Limnol. Oceanogr. Methods 2016, 14, 767–783, doi:10.1002/lom3.10122.

(3): Reference 49 should be the following:

Christensen, P.B.; Nielsen, L.P.; Sørensen, J.; Revsbech, N.P. Denitrification in Nitrate-Rich Streams: Diurnal and Seasonal Variation …


Comparison Of Four Nitrate Removal Kinetic Models In Two Distinct Wetland Restoration Mesocosm Systems, Tiffany L. Messer, Michael R. Burchell, François Birgand Jan 2017

Comparison Of Four Nitrate Removal Kinetic Models In Two Distinct Wetland Restoration Mesocosm Systems, Tiffany L. Messer, Michael R. Burchell, François Birgand

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The objective of the study was to determine the kinetic model that best fit observed nitrate removal rates at the mesocosm scale in order to determine ideal loading rates for two future wetland restorations slated to receive pulse flow agricultural drainage water. Four nitrate removal models were investigated: zero order, first order decay, efficiency loss, and Monod. Wetland mesocosms were constructed using the primary soil type (in triplicate) at each of the future wetland restoration sites. Eighteen mesocosm experiments were conducted over two years across seasons. Simulated drainage water was loaded into wetlands as batches, with target nitrate-N levels typically …


Development And Validation Of A Tractor Drawbar Force Measurement And Data Acquisition System (Daq), James Roeber, Santosh Pitla, Roger M. Hoy, Joe D. Luck, Michael F. Kocher Jan 2017

Development And Validation Of A Tractor Drawbar Force Measurement And Data Acquisition System (Daq), James Roeber, Santosh Pitla, Roger M. Hoy, Joe D. Luck, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Matching agricultural tractors to implements towed by the drawbar is one of the important aspects of machinery management for ensuring optimum performance and fuel cost savings. A field deployable tractor draft force measurement and data acquisition system was developed and evaluated as part of this research project. A drawbar instrumented to measure draft force in field operating conditions was developed and statically calibrated. The drawbar was calibrated by applying loads from 4.45 to 134 kN using a hydraulic cylinder connected to a 444.8 kN load cell. Testing was conducted with the drawbar installed on a tractor on a concrete track. …


Green And Sustainable Technology For High-Efficiency And Low- Damage Manipulation Of Densely Crosslinked Proteins, Helan Xu, Kaili Song, Bingnan Mu, Yiqi Yang Jan 2017

Green And Sustainable Technology For High-Efficiency And Low- Damage Manipulation Of Densely Crosslinked Proteins, Helan Xu, Kaili Song, Bingnan Mu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A two-step technology using nontoxic and ecofriendly chemicals is developed for the durable setting of densely/highly crosslinked proteins, such as wool and hair. Currently, most technologies for morphological modification are effective only for materials from non-highly-crosslinked proteins and cellulose. Before their morphological change, only water is needed to interrupt hydrogen bonds and ionic linkages, which stabilize the relative positions of molecules in non-highlycrosslinked proteins and cellulose. However, highly crosslinked proteins contain disulfide crosslinks, which are insusceptible to water. Thus, the controlled cleavage of disulfide bonds is required for creating new morphologies of highly crosslinked protein materials, such as hair and …


Differences In Soil Biological Activity By Terrain Types At The Sub-Field Scale In Central Iowa Us, Amy L. Kaleita, Linda R. Schott, Sarah K. Hargreaves, Kirsten S. Hofmockel Jan 2017

Differences In Soil Biological Activity By Terrain Types At The Sub-Field Scale In Central Iowa Us, Amy L. Kaleita, Linda R. Schott, Sarah K. Hargreaves, Kirsten S. Hofmockel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soil microbial communities are structured by biogeochemical processes that occur at many different spatial scales, which makes soil sampling difficult. Because soil microbial communities are important in nutrient cycling and soil fertility, it is important to understand how microbial communities function within the heterogeneous soil landscape. In this study, a self-organizing map was used to determine whether landscape data can be used to characterize the distribution of microbial biomass and activity in order to provide an improved understanding of soil microbial community function. Points within a row crop field in southcentral Iowa were clustered via a self-organizing map using six …