Engineering Commons^™

Normalized Effect Of Condenser Fouling And Refrigerant Charge On Performance Of Vapor Compression Air Conditioning Systems, Mehdi Mehrabi, David Yuill

Durham School of Architectural Engineering and Construction: Faculty Publications

Several laboratory experiments have studied the effect of faults on vapor compression cycle air-conditioning systems. There has been a particular focus on refrigerant charge variation, which is believed to be quite common in air conditioners, and a lesser focus on heat exchanger fouling. The majority of the published results evaluate the fault effects on particular system operating parameters in one unit. For example, the effect on capacity and efficiency are typically evaluated. The results differ from one study to the next. The current paper summarizes the effects for all of the results available in the literature for condenser fouling and …

Electric 4-Wheeler: Making The World A Cleaner Place, Joshua Knighton, Wade Cox

Electrical and Computer Engineering

Due to rising concerns of the air quality, this project was done to demonstrate that carbon dioxide emissions can be eliminated from 4-wheelers by replacing the combustion motor with an electric motor.

The conversion was done using a brushless-DC motor, motor controller, lithium batteries, and an Arduino Mega for instrument control

Remote Diagnosis Of Equipment Failures: A Design For Dynapac Rotating Company, Anthony Swenson

Electrical and Computer Engineering

Dynapac Rotating Company is the industry leader in the design and manufacture of high quality motion products for the sign and display industry.

The president of Dynapac Rotating approached me last summer with a problem he had, and asked me if I would design a solution for my senior project.

Rehabilitation And Strengthening Of Reinforced Concrete Members Using A Fiber Reinforced Cementitious Matrix Composite, Zena Riyadh Aljazaeri

Doctoral Dissertations

“Externally bonded fiber reinforced cementitious matrix (FRCM) for structural members was tested and evaluated as a new class of composite material for repairing and strengthening infrastructures. In comparison with fiber reinforced polymer (FRP) composites, FRCM composite has a superior high temperature resistance and great compatibility with concrete substrates. Experimental investigation is ongoing in the United States to evaluate the structural and durability performance of FRCM composite to be implemented in field applications. This experimental program consisted of testing 12 strengthened reinforced concrete (RC) beams to study the fatigue and flexure performance under environmental exposure and sustained stress, 10 strengthened RC …

Shield: Shotgun Interdiction Of Enemy Low-Flying Drones, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

When conventional disruption and neutralization methods fail, it’s time to choose a kinetic solution. SHIELD is a preliminary concept for an automatic, state-of-the art kinetic defense system. Drones can be eliminated at ranges up to 100 meters. The SHIELD weapon system design consists of an ultra-reliable, high-capacity, semiautomatic shotgun with tungsten shot. This weapon system is coupled with precision pointing, target tracking, and real-time ballistics, ensuring high first-round hit probability. Battle-network capable, SHIELD can perform slew-to-cue operations and cue other networked systems.

Celis: Compact Eyesafe Lidar System, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SDL has developed a novel Compact Eyesafe Lidar System (CELiS) designed to monitor airborne particulate matter (PM) emissions. It uses a 1.57 µm wavelength commercial laser, an 8 inch off-axis parabolic mirror, and a 200 µm diameter InGaAs avalanche photodetector (APD). The laser, mirror, and APD are mounted on a carbon fiber breadboard and housed in an environmentally-sealed housing. CELiS can operate over an 80°C temperature range with an optical path change of only 100 µm.

Rdg: Remote Door Gunner, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Leveraging decades of experience in precision optical and spacecraft pointing systems, SDL developed the Remote Door Gunner (RDG) system, a M240/M134 door gunner station. RDG was designed for operation inside a UH-60 Black Hawk helicopter.

Calibration Considerations For A Reduced-Timeline Optimized Approach For Vnir Earth-Orbiting Satellites, Zachary Bergen, Joe Tansock

Space Dynamics Laboratory Publications

With the increasing number of commercial satellite constellations launching, the need for calibration remains as relevant as ever. Some of these instruments are built with COTS optical components and, given the number and need for timely calibration, a flexible, dynamic, and streamlined approach is necessary for reproducibility, regression testing, adaptability, and high-quality image data. We present a use case for a commercial VNIR payload and demonstrate techniques and a storyboard of our experience. We ran a calibration campaign on a 100” focal length telescope assembled in a payload of approximate 50kg containing a commercial Bayer pattern camera of medium resolution …

Design And Use Of The Ionospheric Connection Explorer Payload Mockup, Burt Lamborn, John Elwell, Andy Little, William Craig, Rich Rynders, Eric Moulton

Space Dynamics Laboratory Publications

The Ionospheric Connection Explorer (ICON) satellite contains six science instruments that are integrated into a small volume on a single payload interface plate (PIP). Integrating these six instruments onto a single deck was challenging and complex in part due to their different physical configurations. After investigating various methods of reducing integration schedule and risk, an innovative approach of creating a high-fidelity full-scale mockup using 3D printed parts was chosen to address these concerns. This mockup included all instruments, the PIP, and associated harnessing, plumbing, and blanketing components. While the mockup integration effort yielded invaluable information for the flight payload integration, …

Making 3d Images, Bryce Walker

Electrical and Computer Engineering

The Idea: Turn a mirascope into an animated 3D imaging device by replacing the top mirror and frog with an LED screen and an optical filter.

Bluetooth Low Energy Quantum Meter, Christopher Clark

Electrical and Computer Engineering

The purpose of this project is to design a quantum meter that interfaces with a mobile device. A quantum meter is a type of light sensor that measures the light in the spectrum that causes photosynthesis, which is 400 to 700 nanometers.

Di2e: Defense Intelligence Information Enterprise, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

The rising demand for rapid intelligence software solutions combined with limited Government funding has highlighted the need for an organized process to use resources more efficiently. The solution needed to leverage existing capabilities to meet mission needs and ensure that defense intelligence information flows seamlessly across enterprise boundaries. In response, as a Government initiative, the NRO and AFRL developed the Defense Intelligence Information Enterprise (DI2E) framework as a solution to promote intelligence software asset reuse where possible.

Comparison Of Selected Differential Producing, Ultrasonic And Magnetic Flow Meters, Johnny B. Prettyman, Michael C. Johnson, Steven L. Barfuss

Civil and Environmental Engineering Faculty Publications

Selecting the best flow meter for a specific application can be challenging because of the many types and designs of flow meters, with each having its own merits and drawbacks. Illustrating these specific benefits and drawbacks can help the buyer select the meter best suited for the desired application. The flow meters investigated in this research include five designs of differential-pressure meters (i.e., differential-producing), a magnetic flow meter, and an ultrasonic flow meter. The differential meters included the Venturi designs, the wedge flow meter, and the V-cone meter. Testing was completed at the Utah Water Research Laboratory to quantify the …

Analyses, Calibration And Validation Of Evapotranspirationmodels To Predict Grass-Reference Evapotranspiration In Thesenegal River Delta, Koffi Djaman, Hossein Tabari, Alpha B. Balde, Lamine Diop, Koichi Futakuchi, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Study region: Grass-reference evapotranspiration estimation by the Penman-Monteithmethod (PM-ETo) requires a number of climate variables which are not always availableat all weather stations. Different alternative ETo equations have been developed and theirutilization for various local climate conditions requires analyses of their accuracy as com-pared to the standardized Penman-Monteith method. There is a significant lack of data andinformation on this topic in the Senegal River Delta (SRD). Study focus: The objective of this study was to evaluate, calibrate and validate six EToequations ((Trabert, Mahringer, Penman1948, Albrecht, Valiantzas1 and Valiantzas2) forthe SRD. Although all six equations showed good agreement with the PM-ETo …

Control Architecture For Multi-Robot System, John H. Posselius, Christopher A. Foster, Santosh K. Pitla, Scott A. Shearer, Joe D. Luck, Michael P. Sama, Rodrigo S. Zandonadi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A multiple robot control architecture including a plurality of robotic agricultural machines including a first and second robotic agricultural machine. Each robotic agricultural machine including at least one controller configured to implement a plurality of finite state machines within an individual robot control architecture (IRCA) and a global information module (GIM) communicatively coupled to the IRCA. The GIMs of the first and second robotic agricultural machines being configured to cooperate to cause said first robotic agricultural machine and said second agricultural machine to perform at least one agricultural task.

Direct And Indirect Effects Of Climatic Variations On The Interannual Variability In Net Ecosystem Exchange Across Terrestrial Ecosystems, Junjiong Shao, Xuhui Zhou, Yiqi Luo, Bo Li, Mika Aurela, David Billesbach, Peter D. Blanken, Rosvel Bracho, Jiquan Chen, Marc Fischer, Yuling Fu, Lianhong Gu, Shijie Han, Yongtao He, Thomas Kolb, Yingnian Li, Zoltan Nagy, Shuli Niu, Walter C. Oechel, Krisztina Pinter, Peili Shi, Andrew Suyker, Margaret Torn, Andrej Varlagin, Huimin Wang, Junhua Yan, Guirui Yu, Junhui Zhang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climatic variables not only directly affect the interannual variability (IAV) in net ecosystem exchange of CO2 (NEE) but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C) dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor …

A Generalized Spatial Measure For Resilience Of Microbial Systems, Ryan S. Renslow, Stephen R. Lindemann, Hyun-Seob Song

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The emergent property of resilience is the ability of a system to return to an original state after a disturbance. Resilience may be used as an early warning system for significant or irreversible community transition; that is, a community with diminishing or low resilience may be close to catastrophic shift in function or an irreversible collapse. Typically, resilience is quantified using recovery time, which may be difficult or impossible to directly measure in microbial systems. A recent study in the literature showed that under certain conditions, a set of spatial-based metrics termed recovery length, can be correlated to recovery time, …

Switchgrass Storage Effects On The Recovery Of Carbohydrates After Liquid Hot Water Pretreatment And Enzymatic Hydrolysis, Noaa Frederick, Mengxing Li, Danielle Julie Carrier, Michael D. Buser, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW) and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass …

Ecosystem Evapotranspiration: Challenges In Measurements, Estimates, And Modeling, D.M. Amatya, Sibel Irmak, P. Gowda, G. Sun, J.E. Nettles, K.R. Douglas-Mankin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Evapotranspiration (ET) processes at the leaf to landscape scales in multiple land uses have important con- trols and feedbacks for local, regional, and global climate and water resource systems. Innovative methods, tools, and technologies for improved understanding and quantification of ET and crop water use are critical for adapting more effective management strategies to cope with increasing demand for freshwater resources under global climate change. This article introduces an ASABE Special Collection of 12 articles on ET monitoring and modeling research for multiple land uses and scales. The collection focuses on recent advances in four critical topical areas: (1) reference …

Objective Climatological Analysis Of Extreme Weather Events In Arizona During The North American Monsoon, Jeremy J. Mazon, Christopher L. Castro, David K. Adams, Hsin-I Chang, Carlos M. Carrillo, John J. Brost

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Almost one-half of the annual precipitation in the southwestern United States occurs during the North American monsoon (NAM). Given favorable synoptic-scale conditions, organized monsoon thunderstorms may affect relatively large geographic areas. Through an objective analysis of atmospheric reanalysis and observational data, the dominant synoptic patterns associated with NAM extreme events are determined for the period from 1993 to 2010. Thermodynamically favorable extreme-weather-event days are selected on the basis of atmospheric instability and precipitable water vapor from Tucson, Arizona, rawinsonde data. The atmospheric circulation patterns at 500 hPa associated with the extreme events are objectively characterized using principal component analysis. The …

Critical Factors Affecting The Integration Of Biomass Gasification And Syngas Fermentation Technology, Karthikeyan D. Ramachandriya, Dimple K. Kundiyana, Ashokkumar M. Sharma, Ajay Kumar, Hasan K. Atiyeh, Raymond L. Huhnke, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gasification-fermentation is a thermochemical-biological platform for the production of fuels and chemicals. Biomass is gasified at high temperatures to make syngas, a gas composed of CO, CO2, H2, N2 and other minor components. Syngas is then fed to anaerobic microorganisms that convert CO, CO2 and H2 to alcohols by fermentation. This platform offers numerous advantages such as flexibility of feedstock and syngas composition and lower operating temperature and pressure compared to other catalytic syngas conversion processes. In comparison to hydrolysis-fermentation, gasification-fermentation has a major advantage of utilizing all organic components of biomass, including lignin, to yield higher fuel production. Furthermore, …

Long-Term Patterns Of Air Temperatures, Daily Temperature Range, Precipitation, Grass-Reference Evapotranspiration And Aridity Index In The Usa Great Plains: Part Ii. Temporal Trends, Meetpal S. Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Detection of long-term changes in climate variables over large spatial scales is a very important prerequisite to the development of effective mitigation and adaption measures for the future potential climate change and for developing strategies for future hydrologic balance analyses under changing climate. Moreover, there is a need for effective approaches of providing information about these changes to decision makers, water managers and stakeholders to aid in efficient implementation of the developed strategies. This study involves computation, mapping and analyses of long-term (1968-2013) county-specific trends in annual, growing-season (1st May- 30th Sept.) and monthly air temperatures [(maximum (T_max), …

Long-Term Patterns Of Air Temperatures, Daily Temperature Range, Precipitation, Grass-Reference Evapotranspiration And Aridity Index In The Usa Great Plains: Part I. Spatial Trends, Meetpal S. Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Due to their substantial spatio-temporal behavior, long-term quantification and analyses of important hydrological variables are essential for practical applications in water resources planning, evaluating the water use of agricultural crop production and quantifying crop evapotranspiration patterns and irrigation management vs. hydrologic balance relationships. Observed data at over 800 sites across the Great Plains of USA, comprising of 9 states and 2,307,410 km² of surface area, which is about 30% of the terrestrial area of the USA, were used to quantify and map large-scale and long-term (1968-2013) spatial trends of air temperatures, daily temperature range (DTR), precipitation, grass-reference evapotranspiration (ET …

Pch1 Integrates Circadian And Light- Signaling Pathways To Control Photoperiod-Responsive Growth In Arabidopsis, He Huang, Chan Yul Yoo, Rebecca Bindbeutel, Jessica Goldsworthy, Allison Tielking, Sophie Alvarez, Michael J. Naldrett, Bradley S. Evans, Meng Chen, Dmitri A. Nusinow

Nebraska Center for Biotechnology: Faculty and Staff Publications

Plants react to seasonal change in day length through altering physiology and development. Factors that function to harmonize growth with photoperiod are poorly understood. Here we characterize a new protein that associates with both circadian clock and photoreceptor components, named PHOTOPERIODIC CONTROL OF HYPOCOTYL1 (PCH1). pch1 seedlings have overly elongated hypocotyls specifically under short days while constitutive expression of PCH1 shortens hypocotyls independent of day length. PCH1 peaks at dusk, binds phytochrome B (phyB) in a red light-dependent manner, and co-localizes with phyB into photobodies. PCH1 is necessary and sufficient to promote the biogenesis of large photobodies to maintain an …

Heterogeneity Influences On Stream Water–Groundwater Interactions In A Gravel-Dominated Floodplain, R. B. Miller, Derek M. Heeren, Garey A. Fox, Todd Halihan, Daniel E. Storm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Floodplains are composed of complex depositional patterns of ancient and recent stream sediments, and research is needed to address the manner in which coarse floodplain materials affect stream/groundwater exchange patterns. Efforts to understand the heterogeneity of aquifers have utilized numerous techniques typically focused on point-scale measurements; however, in highly heterogeneous settings, the ability to model heterogeneity is dependent on the data density and spatial distribution. The objective of this research was to investigate the correlation between broad-scale methodologies for detecting heterogeneity and the observed spatial variability in stream/groundwater interactions of gravel-dominated alluvial floodplains. More specifically, this study examined the correlation …

Using Swat To Enhance Watershed-Based Plans To Meet Numeric Water Quality Standards, Aaron R. Mittelstet, Daniel E. Storm, Michael J. White

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The number of states that have adopted numeric nutrient water-quality standards has increased to 23, up from ten in 1998. One state with both stream and reservoir phosphorus (P) numeric water-quality standards is Oklahoma. There were two primary objectives of this research: (1) determine if Oklahoma was meeting the stream and reservoir numeric water-quality standards in the Illinois River and Eucha–Spavinaw watersheds, respectively and (2) identify various combinations of management practices required to meet the water-quality standards. A Soil and Water Assessment Tool (SWAT) model was developed for each watershed. After runoff and P calibration and validation, each model was …

Calibration Procedure For Fuel Flow Meters At The Nebraska Tractor Test Lab, Michael F. Kocher, Matthew T. Wold, Roger M. Hoy, Austin Lammers, Erin E. Blankenship

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reports in the literature indicated several factors that can influence the accuracy of Coriolis Effect mass flow meters. A Coriolis Effect mass flow meter is used to verify tractor manufacturer’s fuel consumption claims at the Nebraska Tractor Test Laboratory (NTTL). The accuracy requirement placed on the flow meter by the Organization for Economic Co-operation and Development (OECD) in the Code 2 tractor performance test procedure is not clear, but in the most conservative interpretation is ±0.5% of each flow rate measured. Results showed a dynamic weighing calibration method was not accurate enough to obtain a calibration of the flow meter …

Temporal Dynamics Of Maize Plant Growth, Water Use, And Leaf Water Content Using Automated High Throughput Rgb And Hyperspectral Imaging, Yufeng Ge, Geng Bai, Vincent Stoerger, James C. Schnable

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Automated collection of large scale plant phenotype datasets using high throughput imaging systems has the potential to alleviate current bottlenecks in data-driven plant breeding and crop improvement. In this study, we demonstrate the characterization of temporal dynamics of plant growth and water use, and leaf water content of two maize genotypes under two different water treatments. RGB (Red Green Blue) images are processed to estimate projected plant area, which are correlated with destructively measured plant shoot fresh weight (FW), dry weight (DW) and leaf area. Estimated plant FW and DW, along with pot weights, are used to derive daily plant …

Pumpage Reduction By Using Variable Rate Irrigation To Mine Undepleted Soil Water, Tsz Him Lo, Derek M. Heeren, Derrel Martin, Luciano Mateos, Joe D. Luck, Dean E. Eisenhauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conventional irrigation schedules are typically based on portions of the field where root zones hold the least available soil water. This leaves undepleted available water in areas with larger water holding capacities. The undepleted water could be used through variable-rate irrigation (VRI) management; however, the benefits of VRI without in-field mapping are unexamined. In this research, the field-averaged amount of undepleted available soil water in the root zone was calculated from the NRCS Soil Survey Geographic database for 49,224 center-pivot irrigated fields in Nebraska. Potential reductions in pumpage from mining undepleted available water were then estimated. Results of the analysis …

Analytical Solution For Speed To Achieve A Desired Operating Point For A Given Fan Or Pump, Michael F. Kocher, Jeyamkondan Subbiah

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Affinity Laws for fans (and pumps) provide a way of determining new fan or pump speed given fan or pump performance curve data and a desired operating point (combination of flow rate and pressure) that does not fall on the curve. However, the affinity law calculations require using a point on the curve (hereafter referred to as the “basic point”) to determine the new speed. Most references regarding the Affinity Laws do not give a clear description of the method for determining the “basic point”, and improper selection of this point can affect the results considerably. This article describes …