Other Civil and Environmental Engineering Commons^™

A Geospatial Variable Rate Irrigation Control Scenario Evaluation Methodology Based On Mining Root Zone Available Water Capacity, K. A. Miller, Joe Luck, Derek M. Heeren, T. Lo, Derrel Martin, J. B. Barker

Department of Biological Systems Engineering: Papers and Publications

Increasing concern for sustainable water use has the agriculture industry working toward higher efficiency in use of irrigation water. Recent advancements have improved the capabilities of center pivot irrigation systems to vary water application depths across the field, a technology known as variable rate irrigation (VRI). The goal of this study was to provide a geospatial method for potential VRI technology adopters to evaluate control scenarios and potential water savings using freely available datasets. Root zone available water capacity (R) was estimated spatially across two case study fields using the Natural Resources Conservation Service Gridded Soil Survey Geographic Database. The …

A Novel Diffuse Fraction-Based Two-Leaf Light Use Efficiency Model: An Application Quantifying Photosynthetic Seasonality Across 20 Ameriflux Flux Tower Sites, Hao Yan, Shao-Qiang Wang, Kai-Liang Yu, Bin Wang, Qin Yu, Gil Bohrer, Dave P. Billesbach, Rosvel Bracho, Faiz Rahman

Department of Biological Systems Engineering: Papers and Publications

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Diffuse radiation can increase canopy light use efficiency (LUE). This creates the need to differentiate the effects of direct and diffuse radiation when simulating terrestrial gross primary production (GPP). Here, we present a novel GPP model, the diffuse-fraction-based two-leaf model (DTEC), which includes the leaf response to direct and diffuse radiation, and treats maximum LUE for shaded leaves (ε_msh defined as a power function of the diffuse fraction (D_f)) and sunlit leaves (ε_msu defined as a constant) separately. An Amazonian rainforest site (KM67) was used to calibrate the model by simulating the linear relationship between …

The Assessment Of Water Resources In Ungauged Catchments In Rwanda, O. P. Abimbola, J. Wenninger, R. Venneker, Aaron R. Mittelstet

Department of Biological Systems Engineering: Papers and Publications

Study region: Rwanda is a landlocked country in Africa with precipitation ranging from 800 mm yr−1 in the east to 1500 mm yr−1 in high-altitude regions in the north and west. Study focus: Streamflow estimation is an important task that is required in water resource assessments due to its importance in planning, decision-making and economic development. In this study, streamflow characteristics of ungauged catchments in Rwanda were calculated using a regionalization approach based on climate similarity and stepwise multiple-regression analysis. One climatic homogeneous region was identified and datasets of nine gauged stations and general available catchment characteristics were …

Crop Classification And Lai Estimation Using Original And Resolution-Reduced Images From Two Consumer-Grade Cameras, Jian Zhang, Chenghai Yang, Biquan Zhao, Huaibo Song, Wesley Clint Hoffmann, Yeyin Shi, Dongyan Zhang, Guozhong Zhang

Department of Biological Systems Engineering: Papers and Publications

Consumer-grade cameras are being increasingly used for remote sensing applications in recent years. However, the performance of this type of cameras has not been systematically tested and well documented in the literature. The objective of this research was to evaluate the performance of original and resolution-reduced images taken from two consumer-grade cameras, a RGB camera and a modified near-infrared (NIR) camera, for crop identification and leaf area index (LAI) estimation. Airborne RGB and NIR images taken over a 6.5-square-km cropping area were mosaicked and aligned to create a four-band mosaic with a spatial resolution of 0.4 m. The spatial resolution …

Nanoparticle For Targeting Brain Tumors And Delivery Of O6 - Benzylguanine, University Of Washington, Seattle

Department of Biological Systems Engineering: Papers and Publications

Nanoparticle having a crosslinked chitosan - polyethylene oxide oligomer copolymer coating to which O⁶ - benzylgua nine is covalently coupled , compositions that include the nanoparticle , and methods for using the nanoparticle to treat brain cancers .

The Effect Of Single-Handed Lifting Tasks On The Activation Of The Neck-Shoulder Shared Musculature, Mohamed R. Amar, David Cochran, Jeffrey Woldstad

Department of Biological Systems Engineering: Papers and Publications

The use of the hand in lifting has been linked to occupational injuries of the neck and shoulder. This research is aimed at examining the effect of work-related factors on the major neck-shoulder shared musculature activity on both sides of the cervical spine for a right-handed lifting task. Subjects lifted different weights from 20 different locations produced by the interaction of varying heights, reach distance, and angles simulating the work done by assembly line workers. All lifting tasks were done by the right hand. Bilateral electromyography data of major shared musculature (upper trapezius, sternocleidomastoid, and levator scapula) were collected using …

Regulation-Structured Dynamic Metabolic Model Provides A Potential Mechanism For Delayed Enzyme Response In Denitrification Process, Hyun-Seob Song, Dennis G. Thomas, James C. Stegen, Minjing Li, Chongxuan Liu, Xuehang Song, Xingyuan Chen, Jim K. Fredrickson, John M. Zachara, Timothy D. Scheibe

Department of Biological Systems Engineering: Papers and Publications

In a recent study of denitrification dynamics in hyporheic zone sediments, we observed a significant time lag (up to several days) in enzymatic response to the changes in substrate concentration. To explore an underlying mechanism and understand the interactive dynamics between enzymes and nutrients, we developed a trait-based model that associates a community’s traits with functional enzymes, instead of typically used species guilds (or functional guilds). This enzyme-based formulation allows to collectively describe biogeochemical functions of microbial communities without directly parameterizing the dynamics of species guilds, therefore being scalable to complex communities. As a key component of modeling, we accounted …

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 Biological Systems Engineering: Papers and 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

Department of Biological Systems Engineering: Papers and 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 …

A Case Study Of Field-Scale Maize Irrigation Patterns In Western Nebraska: Implications For Water Managers And Recommendations For Hyper-Resolution Land Surface Modeling, Justin P. Gibson, Trenton E. Franz, Tiejun Wang, John Gates, Patricio Grassini, Haishun Yang, Dean E. Eisenhauer

Department of Biological Systems Engineering: Papers and Publications

In many agricultural regions, the human use of water for irrigation is often ignored or poorly represented in land surface models (LSMs) and operational forecasts. Because irrigation increases soil moisture, feedback on the surface energy balance, rainfall recycling, and atmospheric dynamics is not represented and may lead to reduced model skill. In this work, we describe four plausible and relatively simple irrigation routines that can be coupled to the next generation of hyper-resolution LSMs operating at scales of 1 km or less. The irrigation output from the four routines (crop model, precipitation delayed, evapotranspiration replacement, and vadose zone model) is …

Moving Integrated Weed Management From Low Level To A Truly Integrated And Highly Specific Weed Management System Using Advanced Technologies, S. L. Young, S. K. Pitla, F. K. Van Evert, J. K. Schueller, F. J. Pierce

Department of Biological Systems Engineering: Papers and Publications

Integrated weed management (IWM) is one of the most commonly referred to approaches for sustainable and effective weed control in agriculture, yet it is not widely practiced, likely because current IWM systems fail to meet performance expectations of growers. The effectiveness and value of IWM systems should increase with increasing application specificity and true integration made possible with contemporary advances in technology, information systems and decision support. IWM systems can be classified based on their degree of application specificity and level of integration of tactics. In the application specificity pathway, a tactic is applied at a range of scales, from …

Runoff Water Quality Characteristics Following Swine Slurry Application Under Broadcast And Injected Conditions, Nicole R. Schuster, Shannon L. Bartelt-Hunt, Lisa M. Durso, John E. Gilley, Xu Li, David B. Marx, Amy M. Schmidt, Daniel D. Snow

Department of Biological Systems Engineering: Papers and Publications

This study was conducted to measure the effects of swine slurry application method, time following slurry application, and runoff rate on selected water quality characteristics. Slurry from a commercial swine operation was broadcast or injected on field plots at a rate required to meet annual nitrogen requirements for corn. Rainfall simulation tests were conducted at five varying periods following slurry application. During each study period, three simulated rainfall events, separated by 24 h intervals, were applied for 30 min duration at an intensity of approximately 70 mm h^-1. Following the third rainfall simulation event, inflow was applied at …

Large Co2 And Ch4 Emissions From Polygonal Tundra During Spring Thaw In Northern Alaska, Naama Raz-Yaseef, Margaret S. Torn, Yuxin Wu, David P. Billesbach, Anna K. Liljedahl, Timothy J. Kneafsey, Vladimir E. Romanovsky, David R. Cook, Stan D. Wullschleger

Department of Biological Systems Engineering: Papers and Publications

The few prethaw observations of tundra carbon fluxes suggest that there may be large spring releases, but little is known about the scale and underlying mechanisms of this phenomenon. To address these questions, we combined ecosystem eddy flux measurements from two towers near Barrow, Alaska, with mechanistic soil-core thawing experiment. During a 2 week period prior to snowmelt in 2014, large fluxes were measured, reducing net summer uptake of CO₂ by 46% and adding 6% to cumulative CH₄ emissions. Emission pulses were linked to unique rain-on-snow events enhancing soil cracking. Controlled laboratory experiment revealed that as surface ice …

Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 1. Leaf Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko

Department of Biological Systems Engineering: Papers and Publications

The goal of this study was to explore the relationships between the photochemical reflectance index (PRI) at the leaf level and pigment pools, focusing on the constitutive role of pigments in influencing PRI over seasonal or ontogenetic time frames. The purpose was to re-evaluate the role of PRI as an indicator of seasonally shifting pigment (chlorophyll, carotenoid and anthocyanin) contents, and hence photosynthetic activity, across a range of tree and crop species. We studied natural vegetation — three tree species (maple, chestnut and beech) and two managed irrigated and rain-fed crop species (maize and soybean), contrasting in photosynthetic pathway and …