Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 61561 - 61590 of 197986

Full-Text Articles in Engineering

A Decade Of Unmanned Aerial Systems In Irrigated Agriculture In The Western U.S., Jose L. Chavez, Alfonso F. Torres-Rua, Wayne E. Woldt, Huihui Zhang, Christopher Robertson, Gary W. Marek, Dong Wang, Derek M. Heeren, Saleh Taghvaeian, Christopher M. U. Neale Jan 2020

A Decade Of Unmanned Aerial Systems In Irrigated Agriculture In The Western U.S., Jose L. Chavez, Alfonso F. Torres-Rua, Wayne E. Woldt, Huihui Zhang, Christopher Robertson, Gary W. Marek, Dong Wang, Derek M. Heeren, Saleh Taghvaeian, Christopher M. U. Neale

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Several research institutes, laboratories, academic programs, and service companies around the United States have been developing programs to utilize small unmanned aerial systems (sUAS) as an instrument to improve the efficiency of in-field water and agronomical management. This article describes a decade of efforts on research and development efforts focused on UAS technologies and methodologies developed for irrigation management, including the evolution of aircraft and sensors in contrast to data from satellites. Federal Aviation Administration (FAA) regulations for UAS operation in agriculture have been synthesized along with proposed modifications to enhance UAS contributions to irrigated agriculture. Although it is feasible …

Go to article

Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, T. M. Brown-Brandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda Jan 2020

Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, T. M. Brown-Brandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology- related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at …

Go to article

Ultrasmall Mixed Eu−Gd Oxide Nanoparticles For Multimodal Fluorescence And Magnetic Resonance Imaging Of Passive Accumulation And Retention In Tbi, Badrul Alam Bony, Hunter A. Miller, Aria W. Tarudji, Connor C. Gee, Anandakumar Sarella, Michael G. Nichols, Forrest Kievit Jan 2020

Ultrasmall Mixed Eu−Gd Oxide Nanoparticles For Multimodal Fluorescence And Magnetic Resonance Imaging Of Passive Accumulation And Retention In Tbi, Badrul Alam Bony, Hunter A. Miller, Aria W. Tarudji, Connor C. Gee, Anandakumar Sarella, Michael G. Nichols, Forrest Kievit

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. TBI can have a long-term impact on the quality of life for survivors of all ages. However, there remains no approved treatment that improves outcomes following TBI, which is partially due to poor delivery of therapies into the brain. Therefore, there is a significant unmet need to develop more effective delivery strategies that increase the accumulation and retention of potentially efficacious treatments in the injured brain. Recent work has revealed that nanoparticles (NPs) may offer a promising approach for site-specific delivery; however, a detailed understanding of the …

Go to article

Optimal Depth Jump Height Quantified As Percentage Of Athlete Stature, Curtis L. Tomasevicz, Ryan Hasenkamp, Jack W. Ransone, David Jones Jan 2020

Optimal Depth Jump Height Quantified As Percentage Of Athlete Stature, Curtis L. Tomasevicz, Ryan Hasenkamp, Jack W. Ransone, David Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Purpose: An individual’s optimal depth jump platform height provides a resistive force which allows an athlete to rebound with substantial velocity resulting in maximum power exertion. The objective of this investigation was to show that the optimal platform height in a depth jump can be quantified as a percentage of individual body stature which can serve as measurable quantified value. Although athlete height is not highly correlated to power ability nor does a universal height exist, this value can provide a basis for a rehabilitation or strength and conditioning program. The desired intensity of a program can be prescribed as …

Go to article

Comparison Of Object Detection And Patch-Based Classification Deep Learning Models On Mid- To Late-Season Weed Detection In Uav Imagery, Arun Narenthiran Veeranampalayam Sivakumar, Jiating Li, Stephen Scott, Eric T. Psota, Amit J. Jhala, Joe D. Luck, Yeyin Shi Jan 2020

Comparison Of Object Detection And Patch-Based Classification Deep Learning Models On Mid- To Late-Season Weed Detection In Uav Imagery, Arun Narenthiran Veeranampalayam Sivakumar, Jiating Li, Stephen Scott, Eric T. Psota, Amit J. Jhala, Joe D. Luck, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Mid- to late-season weeds that escape from the routine early-season weed management threaten agricultural production by creating a large number of seeds for several future growing seasons. Rapid and accurate detection of weed patches in field is the first step of site-specific weed management. In this study, object detection-based convolutional neural network models were trained and evaluated over low-altitude unmanned aerial vehicle (UAV) imagery for mid- to late-season weed detection in soybean fields. The performance of two object detection models, Faster RCNN and the Single Shot Detector (SSD), were evaluated and compared in terms of weed detection performance using mean …

Go to article

Representing Organic Matter Thermodynamics In Biogeochemical Reations Via Substrate-Explicit Modeling, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Joon-Yong Lee, Vanessa A. Garayburu-Caruso, William C. Nelson, Xingyuan Chen, J. David Moulton, Timothy D. Scheibe Jan 2020

Representing Organic Matter Thermodynamics In Biogeochemical Reations Via Substrate-Explicit Modeling, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Joon-Yong Lee, Vanessa A. Garayburu-Caruso, William C. Nelson, Xingyuan Chen, J. David Moulton, Timothy D. Scheibe

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Predictive biogeochemical modeling requires data-model integration that enables explicit representation of the sophisticated roles of microbial processes that transform substrates. Data from high-resolution organic matter (OM) characterization are increasingly available and can serve as a critical resource for this purpose, but their incorporation into biogeochemical models is often prohibited due to an over-simplified description of reaction networks. To fill this gap, we proposed a new concept of biogeochemical modeling—termed substrate-explicit modeling—that enables parameterizing OM-specific oxidative degradation pathways and reaction rates based on the thermodynamic properties of OM pools. Based on previous developments in the literature, we characterized the resulting kinetic …

Go to article

Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi Jan 2020

Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Latest advances in unmanned aerial vehicle (UAV) technology and convolutional neural networks (CNNs) allow us to detect crop lodging in a more precise and accurate way. However, the performance and generalization of a model capable of detecting lodging when the plants may show different spectral and morphological signatures have not been investigated much. This study investigated and compared the performance of models trained using aerial imagery collected at two growth stages of winter wheat with different canopy phenotypes. Specifically, three CNN-based models were trained with aerial imagery collected at early grain filling stage only, at physiological maturity only, and at …

Go to article

Predicting Total Petroleum Hydrocarbons In Field Soils With Vis–Nir Models Developed On Laboratory-Constructed Samples, Nuwan K. Wijewardane, Yufeng Ge, Natasha Sihota, Thomas Hoelen, Toni Miaso, David C. Weindorf Jan 2020

Predicting Total Petroleum Hydrocarbons In Field Soils With Vis–Nir Models Developed On Laboratory-Constructed Samples, Nuwan K. Wijewardane, Yufeng Ge, Natasha Sihota, Thomas Hoelen, Toni Miaso, David C. Weindorf

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate quantification of petroleum hydrocarbons (PHCs) is required for optimizing remedial efforts at oil spill sites. While evaluating total petroleum hydrocarbons (TPH) in soils is often conducted using costly and time-consuming laboratory methods, visible and near-infrared reflectance spectroscopy (Vis–NIR) has been proven to be a rapid and cost-effective field-based method for soil TPH quantification. This study investigated whether Vis–NIR models calibrated from laboratory-constructed PHC soil samples could be used to accurately estimate TPH concentration of field samples. To evaluate this, a laboratory sample set was constructed by mixing crude oil with uncontaminated soil samples, and two field sample sets (F …

Go to article

High‐ And Low‐Molecular‐Weight Chitosan Act As Adjuvants During Single‐Dose Influenza A Virus Protein Vaccination Through Distinct Mechanisms, Anna T. Lampe, Eric Farris, Deborah M. Brown, Angela K. Pannier Jan 2020

High‐ And Low‐Molecular‐Weight Chitosan Act As Adjuvants During Single‐Dose Influenza A Virus Protein Vaccination Through Distinct Mechanisms, Anna T. Lampe, Eric Farris, Deborah M. Brown, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The investigation of new adjuvants is essential for the development of efficacious vaccines. Chitosan (CS), a derivative of chitin, has been shown to act as an adjuvant, improving vaccine‐induced immune responses. However, the effect of CS molecular weight (MW) on this adjuvanticity has not been investigated, despite MW having been shown to impact CS biological properties. Here, two MW variants of CS were in- vestigated for their ability to enhance vaccine‐elicited immune responses in vitro and in vivo, using a single‐dose influenza A virus (IAV) protein vaccine model. Both low‐ molecular‐weight (LMW) and high‐molecular‐weight (HMW) CS‐induced interferon regulatory factor pathway …

Go to article

Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Schmidt Jan 2020

Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Schmidt

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Land application of manure introduces gastrointestinal microbes into the environ- ment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agri- cultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff. All samples were negative for the 10 b-lactamase genes assayed. For tetracycline resistance, …

Go to article

Setback Distance Impacts On Transport And Antibiotic Resistance Phenotypes Of Fecal Indicators, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Daniel N. Miller, Xu Li, Amy M. Schmidt Schmidt Jan 2020

Setback Distance Impacts On Transport And Antibiotic Resistance Phenotypes Of Fecal Indicators, Morgan A. Meyers, Lisa M. Durso, John E. Gilley, Daniel N. Miller, Xu Li, Amy M. Schmidt Schmidt

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Although the land application of livestock manure has numerous agronomic benefits, runoff from manured fields can degrade water quality. Setbacks instruct a minimum distance be maintained between manure application and surface waters. They are commonly used to manage nutrient contamination of surface waters; however, their utility for reducing microbial inputs remains unclear. Here we evaluated the efficacy of five setback distances in no-till wheat (Triticum aes- tivum L.) residue plots for reducing runoff fecal indicator concentrations from swine manure-amended fields. Also, since there is increasing interest in the use of water quality indicators to monitor antibiotic resistance in environmental sys- …

Go to article

Interrelationships Between Water Use Efficiency And Light Use Efficiency In Four Row Crop Canopies, Meetpal S. Kukal, Suat Irmak Dr. Jan 2020

Interrelationships Between Water Use Efficiency And Light Use Efficiency In Four Row Crop Canopies, Meetpal S. Kukal, Suat Irmak Dr.

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Quantitative evidence of light use efficiency (LUE) controls on water use effi- ciency (WUE) is lacking, especially comparatively across row crops. Field research experiments (2016–2018) were set up for maize (Zea mays L.), soybean [Glycine max (L.) Merr.], sorghum [Sorghum bicolor (L.) Moench], and winter wheat (Triticum aestivum L.), under optimal growth conditions in dry sub-humid conditions. Overall, LUE was able to explain 52% of variance in WUE, and were related as WUE = 1.73 LUE, although crop-specific variation was observed. High- est sensitivity of WUE to changes in LUE was found in sorghum, followed by soybean, winter wheat, and …

Go to article

Innovative Extension Methods In The U.S. To Promote Irrigation Water Management, Daran Rudnick, Matt Stockton, Saleh Taghvaeian, Jason Warren, Michael D. Dukes, Amy Kremen, Christopher G. Henry, Jonathan Aguilar, Brenda Ortiz, Allan A. Andales, Chuck A. Burr, Xin Qiao, Wei‑Zhen Liang, Steven Walthour, Steve H. Amosson Jan 2020

Innovative Extension Methods In The U.S. To Promote Irrigation Water Management, Daran Rudnick, Matt Stockton, Saleh Taghvaeian, Jason Warren, Michael D. Dukes, Amy Kremen, Christopher G. Henry, Jonathan Aguilar, Brenda Ortiz, Allan A. Andales, Chuck A. Burr, Xin Qiao, Wei‑Zhen Liang, Steven Walthour, Steve H. Amosson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extension and outreach programs have been devised to engage and educate growers. This article describes some …

Go to article

Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx Jan 2020

Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The concentrations of phosphorus (P) and nitrogen (N) in runoff from cropland areas may be influenced by accumulation and release of P and N by stalk residues. A laboratory study was conducted to measure the effects of time since harvest and immersion period on accumulation and release of P and N by corn, soybean, and wheat stalks. Experimental variables included type of stalk material (corn, soybean, and wheat), time since harvest (six residue collection dates over an approximate 1-year period), and stalk immersion period (25 s (0.42 min), 250 s (4.2 min), 2500 s (42 min), 25,000 s (6.9 h), …

Go to article

Effect Of Urea Fertilizer Deep Placement Days After Transplanting Using Brri Prilled Urea Applicator On Transplanted Boro Rice Yield, Muhammad Rashed Al Mamun, K. Naher, Md Towfiqur Rahman, Md Anwar Hossen Jan 2020

Effect Of Urea Fertilizer Deep Placement Days After Transplanting Using Brri Prilled Urea Applicator On Transplanted Boro Rice Yield, Muhammad Rashed Al Mamun, K. Naher, Md Towfiqur Rahman, Md Anwar Hossen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rice is the most important crop in the developing countries of Asia. In the south and south-east Asia, rain-fed and irrigated transplanted rice occupies nearly two-thirds of the rice-growing area and produces more than 80% of the rough rice. In these areas, prilled urea conventionally applied by farmers is very insufficient in the transplanted rice field, where severe losses occur (up to 60% of applied N) via NH3volatilization, denitrification, leaching, and runoff. Considering loss minimization, an experiment was conducted during the Boro season at Bangladesh Agricultural Development Corporation (BADC) in Sylhet to evaluate the performance of BRRI Prilled …

Go to article

Effect Of Rotary Blade Modification On Residue Retention Into Conservation Agriculture Practices, Md Talash Mahmud, Md Towfiqur Rahman, Md Mosharraf Hossain, Muhammad Ashik-E-Rabbani Jan 2020

Effect Of Rotary Blade Modification On Residue Retention Into Conservation Agriculture Practices, Md Talash Mahmud, Md Towfiqur Rahman, Md Mosharraf Hossain, Muhammad Ashik-E-Rabbani

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conservation Agriculture (CA) has been a promising technique for better crop production. Manual seeding with conventional tillage practice is laborious and time consuming. However, Strip tillage (ST) method incorporating seeding machines minimizes human drudgery and optimizes the crop yield. Many problems associated with ST have been rectified e.g. tiny furrow backfill, inaccuracy of seed and fertilizer placement, leading to poor germination and curtailed outcomes. This article focused on the effects of residue retention for the rotary blades design on a versatile multi-crop planter (VMP). Four types of rotary blades of VMP differed by 15o increment of tip angles were …

Go to article

Present Mechanization Of Regional Tea Processing And Grading System In Bangladesh, Md Towfiqur Rahman, Marwa Rahman, Kaswar Hamid, Sabiha Ferdous, Muhammad Rashed Al Mamun Jan 2020

Present Mechanization Of Regional Tea Processing And Grading System In Bangladesh, Md Towfiqur Rahman, Marwa Rahman, Kaswar Hamid, Sabiha Ferdous, Muhammad Rashed Al Mamun

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nowadays tea is the most popular beverage crop of Bangladesh which contributes to our national GDP. There are 166 tea gardens in the various region in Bangladesh are producing tea. Some best quality tea is exporting from our country but this amount is negligible due to improper handling and processing systems. Quality tea production from processing houses is beyond control and mostly depends on the processing method. Improper handling and insufficient technology results in lower grade tea, as well as foreign contaminates, are found in made tea. This research focused on the problems of the present of tea processing and …

Go to article

Pilot Selection Research Gaps: What We Do And Don't Know About "The Right Stuff", Thomas C. Scott, Meredith Carroll Jan 2020

Pilot Selection Research Gaps: What We Do And Don't Know About "The Right Stuff", Thomas C. Scott, Meredith Carroll

Aeronautics Faculty Publications

Ever since the commencement of high-powered flight, pilot selection has been a crucial process within military, general, and commercial aviation. Through effective pilot selection, individuals with the necessary aptitudes, or "the right stuff" to get through a training program and successfully perform the job, can be chosen. There is a range of different aptitudes that have been shown through research to correlate with effective pilot performance. However, there is currently not a comprehensive understanding of the aptitudes, including both cognitive abilities and psychological attributes, necessary not only for effective pilot performance but also for a successful career as an aviator. …

Go to article

Examining Pilot Response To Cybersecurity Events On The Flight Deck, Meredith Carroll, Summer Rebensky, Paige Sanchez Jan 2020

Examining Pilot Response To Cybersecurity Events On The Flight Deck, Meredith Carroll, Summer Rebensky, Paige Sanchez

Aeronautics Faculty Publications

Cybersecurity is a growing concern in the aviation industry. In general, cybersecurity research has typically focused on providing technical solutions such as hardening networks and improving computer systems, with little focus on the human operator. Human operators, such as pilots, are often the last line of defense; however, it is currently unclear whether pilots can recognize cybersecurity vulnerabilities, detect when a system is being compromised, and respond appropriately to a cybersecurity event. A review of literature revealed three key stages in cybersecurity response decision process (susceptibility, detection, and response) that are influenced by eight separate factors (perceived susceptibility, perceived safeguard …

Go to article

Examination Of The Impact Of Various Training Approaches On Different Uas Operator Populations, Summer Rebensky, Meredith Carroll, Maria Chaparro Jan 2020

Examination Of The Impact Of Various Training Approaches On Different Uas Operator Populations, Summer Rebensky, Meredith Carroll, Maria Chaparro

Aeronautics Faculty Publications

In recent years, the UAS industry has extended beyond military and recreational use and is now positioned to become a major portion of the aviation industry. As we move toward UAS integration into the national airspace system, UAS operators need effective training to ensure safe operation. Training UAS operators in an engaging way is important to ensure the best performance and transfer of training. Training methods that elicit high levels of learner engagement have been shown to improve knowledge gains, performance, and therefore such training techniques provide an opportunity for improving UAS training effectiveness and transfer. The growth of the …

Go to article

Brassinosteroids Inhibit Autotropic Root Straightening By Modifying Filamentous-Actin Organization And Dynamics, Louise De Bang, Ana Paez-Garcia, Ashley E. Cannon, Sabrina Chin, Jaydeep Kolape, Fuqi Liao, J. Alan Sparks, Qingzhen Jiang, Elison B. Blancaflor Jan 2020

Brassinosteroids Inhibit Autotropic Root Straightening By Modifying Filamentous-Actin Organization And Dynamics, Louise De Bang, Ana Paez-Garcia, Ashley E. Cannon, Sabrina Chin, Jaydeep Kolape, Fuqi Liao, J. Alan Sparks, Qingzhen Jiang, Elison B. Blancaflor

Nebraska Center for Biotechnology: Faculty and Staff Publications

When positioned horizontally, roots grow down toward the direction of gravity. This phenomenon, called gravitropism, is influenced by most of the major plant hormones including brassinosteroids. Epi-brassinolide (eBL) was previously shown to enhance root gravitropism, a phenomenon similar to the response of roots exposed to the actin inhibitor, latrunculin B (LatB). This led us to hypothesize that eBL might enhance root gravitropism through its effects on filamentous-actin (F-actin). This hypothesis was tested by comparing gravitropic responses of maize (Zea mays) roots treated with eBL or LatB. LatB- and eBL-treated roots displayed similar enhanced downward growth compared with controls …

Go to article

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jin Nakashima, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang Jan 2020

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jin Nakashima, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang

Nebraska Center for Biotechnology: Faculty and Staff Publications

Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level (breakstrength and …

Go to article

The Improvement Of Shewhart-Stable Time Series Processes By Applying Jensen-Shannon Complexity Measures To Characterize Emergent Structure, Blaine Lorimer Jan 2020

The Improvement Of Shewhart-Stable Time Series Processes By Applying Jensen-Shannon Complexity Measures To Characterize Emergent Structure, Blaine Lorimer

Electronic Theses and Dissertations, 2020-2023

Despite the nearly universal imperative to continuously improve processes, Shewhart-stable time series are often ignored for improvement because of various generalized assumptions and "rules", many of which are actually very context dependent. The process control literature presents widely divergent views, including the extreme position that stable processes are completely random and therefore any further compensation ("tampering") can only increase process variability. The traditional reductionist approach to process improvement characterizes underlying factors using statistical variance measures, which has been very effective for unstable processes. However, this approach, especially when it involves Shewhart control charts, is generally much less effective for directing …

Go to article

Additive Manufacturing Of Elastomeric Lung Phantoms In Radiation Oncology, Jonathan Sookdeo Jan 2020

Additive Manufacturing Of Elastomeric Lung Phantoms In Radiation Oncology, Jonathan Sookdeo

Electronic Theses and Dissertations, 2020-2023

Cancer is a particularly difficult disease to manage and treat, with cancer of the lung being a notably complex disease to treat with radiation therapy. In this study, a stereolithography-based 3D printing process was developed to fabricate human lung phantoms with identical mechanical and physical properties of human lungs in order to assist with targeted radiation therapy. A highly flexible UV photopolymer material with an elastic modulus of approximately 350 KPa was formulated for use in a custom-built stereolithography-based 3D printing apparatus. The printer built for 3D printing of the photopolymer features a large build volume with off-shelf components with …

Go to article

Study Of Non-Ideal Effects On Shock Wave Propagation, Cory Kinney Jan 2020

Study Of Non-Ideal Effects On Shock Wave Propagation, Cory Kinney

Electronic Theses and Dissertations, 2020-2023

Shock tube experiments provide insightful data on combustion, emissions, and ablation characterization for a wide variety of defense and energy sector research topics. Accurate characterization of shock tube facilities is essential to verifying the accuracy of research data. Non-ideal effects, such as boundary layer growth, introduce uncertainty into pressure and temperature conditions, the primary independent variables of interest for shock tube research results. The effect of boundary layer growth on shock tube experiments was investigated by conducting simulations for University of Central Florida's two geometrically different shock tube using StanShock, a quasi-one-dimensional, reacting, compressible flow solver. The characteristic quantities considered …

Go to article

Indium Phosphide Based Quantum Cascade Lasers Grown On Silicon Substrate, Rowel Go Jan 2020

Indium Phosphide Based Quantum Cascade Lasers Grown On Silicon Substrate, Rowel Go

Electronic Theses and Dissertations, 2020-2023

Quantum Cascade Lasers (QCLs) are semiconductor devices that, currently, have been observed to emit radiation from ~ 2.6 µm to 250 µm (1 to 100 terahertz range of frequencies). They have established themselves as the laser of choice for spectroscopic gas sensing in the mid-wavelength infrared (3-8 µm) and long-wavelength infrared (8-15 µm) region. In the 4-12 µm wavelength region, the highest performing QCL devices, in terms of wall-plug efficiency and continuous wave operation, are indium phosphide (InP) based. The ultimate goal is to incorporate this InP-based QCL technology to silicon (Si) substrate since most opto-electronics are Si-based. The main …

Go to article

Hybrid Physics-Informed Neural Networks For Dynamical Systems, Renato Giorgiani Do Nascimento Jan 2020

Hybrid Physics-Informed Neural Networks For Dynamical Systems, Renato Giorgiani Do Nascimento

Electronic Theses and Dissertations, 2020-2023

Ordinary differential equations can describe many dynamic systems. When physics is well understood, the time-dependent responses are easily obtained numerically. The particular numerical method used for integration depends on the application. Unfortunately, when physics is not fully understood, the discrepancies between predictions and observed responses can be large and unacceptable. In this thesis, we show how to directly implement integration of ordinary differential equations through recurrent neural networks using Python. We leveraged modern machine learning frameworks, such as TensorFlow and Keras. Besides offering basic models capabilities (such as multilayer perceptrons and recurrent neural networks) and optimization methods, these frameworks offer …

Go to article

Control Strategies For Multi-Controller Multi-Objective Systems, Raaed Al-Azzawi Jan 2020

Control Strategies For Multi-Controller Multi-Objective Systems, Raaed Al-Azzawi

Electronic Theses and Dissertations, 2020-2023

This dissertation's focus is control systems controlled by multiple controllers, each having its own objective function. The control of such systems is important in many practical applications such as economic systems, the smart grid, military systems, robotic systems, and others. To reap the benefits of feedback, we consider and discuss the advantages of implementing both the Nash and the Leader-Follower Stackelberg controls in a closed-loop form. However, closed-loop controls require continuous measurements of the system's state vector, which may be expensive or even impossible in many cases. As an alternative, we consider a sampled closed-loop implementation. Such an implementation requires …

Go to article

Identifying Diurnal Variability Of Brain Connectivity Patterns Using Graph Theory, Farzad Vasheghani Farahani Jan 2020

Identifying Diurnal Variability Of Brain Connectivity Patterns Using Graph Theory, Farzad Vasheghani Farahani

Electronic Theses and Dissertations, 2020-2023

Circadian rhythms are 24-hour fluctuations determining periodicity in a wide range of physiological processes, including neural activity and hormone secretion, which controls sleeping and feeding habits. Despite significant diurnal variation in human brain function, neuroscientists have rarely considered the effects of time-of-day on their studies. Moreover, there are interpersonal discrepancies in sleep-wake patterns, diurnal preferences, and daytime alertness (known as chronotypes), which can cause different diurnal profiles in human cognition and brain performance. The study of circadian typology differences has increased in recent years, however, examining the effects of both time-of-day and people's chronotype requires further elucidation. In the present …

Go to article

Detailed Study Of Flow And Surface Heat Transfer Enhancement Mechanism In The Presence Of Dimples And/Or Protrusions, Gaurav Gupta Jan 2020

Detailed Study Of Flow And Surface Heat Transfer Enhancement Mechanism In The Presence Of Dimples And/Or Protrusions, Gaurav Gupta

Electronic Theses and Dissertations, 2020-2023

Recent advancements in material technology have led to the development of non-porous negative Poisson's ratio (NPR) materials (also called auxetic structures) by making spherical inline dimples on both sides of an elastic sheet. Manufacturing technologies such as 3-D printing and additive manufacturing paved the way to realize the complex shapes needed to achieve NPR behavior. These materials are desirable in many engineering applications, especially in the gas turbines hot-gas-path, due to their unique properties. In the current study, an effort is made to understand the flow physics and surface heat transfer mechanism for channel flow having one wall with spherical …

Go to article

First Prev Next Last