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2016

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Full-Text Articles in Engineering

Modeling Factors Contributing To Injury And Fatality Of Run-Off-Road Crashes In Ohio, Deogratias Eustace, Omar Eid Almutairi, Peter W. Hovey Nov 2016

Modeling Factors Contributing To Injury And Fatality Of Run-Off-Road Crashes In Ohio, Deogratias Eustace, Omar Eid Almutairi, Peter W. Hovey

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The main objective of this study was to determine the factors that contribute significantly to the levels of injury severity when run-off-road (ROR) crashes occur. This study used a 5-year crash data for years 2008 - 2012 from the state of Ohio. The decision tree model in conjunction with generalized ordered logit model was used to investigate characteristics of injury and fatality of run-off-road crashes in Ohio.

The decision tree modeling was used for exploratory data analysis identified eight factors that explain a large amount of the variation in the response variable, injury severity. These predictor variables include road condition, …


Technology Trajectory Mapping Using Data Envelopment Analysis: The Ex-Ante Use Of Disruptive Innovation Theory On Flat Panel Technologies, Dong-Joon Lim, Timothy R. Anderson Nov 2016

Technology Trajectory Mapping Using Data Envelopment Analysis: The Ex-Ante Use Of Disruptive Innovation Theory On Flat Panel Technologies, Dong-Joon Lim, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

In this paper, we propose a technology trajectory mapping approach using Data Envelopment Analysis (DEA) that scrutinizes technology progress patterns from multidimensional perspectives. Literature reviews on technology trajectory mappings have revealed that it is imperative to identify key performance measures that can represent different value propositions and then apply them to the investigation of technology systems in order to capture indications of the future disruption. The proposed approach provides a flexibility not only to take multiple characteristics of technology systems into account but also to deal with various tradeoffs among technology attributes by imposing weight restrictions in the DEA model. …


Accident Rates, Phase Of Operations, And Injury Severity For Solo Students In Pursuit Of Private Pilot Certification (1994–2013), Douglas Boyd, Peter Dittmer Nov 2016

Accident Rates, Phase Of Operations, And Injury Severity For Solo Students In Pursuit Of Private Pilot Certification (1994–2013), Douglas Boyd, Peter Dittmer

Publications

Flight training accidents constitute 14% of general aviation accidents. Herein we determined the rates, injury severity, and phase of flight for primary student solo accidents/incidents (mishaps) in Cessna 172 aircraft. Mishaps over the period spanning 1994–2013 were identified from the NTSB database. Student population data were from the FAA. Statistics employed proportion tests, Poisson distribution, and Mann-Whitney tests. Across the study period, 598 mishaps were identified. While the mishap rate increased nearly two-fold between 1994/1997 and 2002/ 2005, a 35% decline was evident thereafter. Nevertheless, no statistical difference in mishap rates was evident between the initial and current periods. Over …


Automotive-Inspired Inceptors And Control Laws Designed For Simplified Piloted Flight, Kashif Ali Nov 2016

Automotive-Inspired Inceptors And Control Laws Designed For Simplified Piloted Flight, Kashif Ali

Doctoral Dissertations and Master's Theses

This thesis details the development of a simulator-based experiment in automotive- inspired controls for aircraft. The goal is to fuse the ease of drivability of a car with the flight of an aircraft. A standard automotive control hardware setup coupled with fly-by-wire control laws will allow non-pilots to fly a plane using their familiarity with driving a car. A mathematical description of the control law logic and controller implementation is presented and the human subjects' performance is measured from data collected during experimental testing of the simulator. Preliminary results indicate that non-pilots improve their path-tracking performance and reduce control activity …


Investigation Of Communication Constraints In Distributed Multi-Agent Systems, Zhaoyang Fu Nov 2016

Investigation Of Communication Constraints In Distributed Multi-Agent Systems, Zhaoyang Fu

Doctoral Dissertations and Master's Theses

Based on a simple flocking model with collision avoidance, a set of investigations of multi-agent system communication constraints have been conducted, including distributed estimation of global features, the influence of jamming, and communication performance optimization. In flocking control, it is necessary to achieve a common velocity among agents and maintain a safe distance between neighboring agents. The local information among agents is exchanged in a distributed fashion to help achieve velocity consensus. A distributed estimation algorithm was recently proposed to estimate the group’s global features based on achieving consensus among agents’ local estimations of such global features. To reduce the …


Study Of Surface Tension, Natural Evaporation, And Subcooled Boiling Evaporation Of Aqueous Surfactant Solutions, Matthew John Lehman Nov 2016

Study Of Surface Tension, Natural Evaporation, And Subcooled Boiling Evaporation Of Aqueous Surfactant Solutions, Matthew John Lehman

Doctoral Dissertations and Master's Theses

The relation between surface tension and surfactant concentration and its effect on solution evaporation under natural convection and subcooled pool boiling is examined through experimental methods. Aqueous solutions of sodium lauryl sulfate (SLS), ECOSURFTM EH-14, and ECOSURFTM SA-9 are used in this study. SLS is an anionic surfactant while EH-14 and SA-9 are environmentally-friendly nonionic surfactants.

Surfactants, surface active agents, are known to affect evaporation performance of solutions and are studied in relation to water loss prevention and heat dissipation. Surfactants could be useful under drought conditions which present challenges to water management on a yearly basis in arid areas …


A Computer Program For The Coupled Implementation Of Meanline And Throughflow Methods To Simplify The Aerodynamic Design Of Multistage Axial Compressors, Alexander V. Rozendaal Nov 2016

A Computer Program For The Coupled Implementation Of Meanline And Throughflow Methods To Simplify The Aerodynamic Design Of Multistage Axial Compressors, Alexander V. Rozendaal

Doctoral Dissertations and Master's Theses

A computer program capable of simplifying the preliminary aerodynamic design process of multistage axial compressors has been developed. This interactive design tool, named C-STAAC, combines the Meanline and Throughflow analysis capabilities of two independent compressor design codes to form one standalone system. The program greatly improves the efficiency of the Preliminary-to-Throughflow stages of compressor design by providing fully coupled interaction between the two platforms. The result enables the user to produce stacked airfoil geometry from only a handful of initial input parameters.

The program additionally offers a wide selection of pre- and post-processing capabilities that were not previously available with …


A Robust Speaker Identification Algorithm Based On Atomic Decomposition And Sparse Redundant Dictionary Learning, Thomas James Bryan Jr. Nov 2016

A Robust Speaker Identification Algorithm Based On Atomic Decomposition And Sparse Redundant Dictionary Learning, Thomas James Bryan Jr.

Theses and Dissertations

Speaker identification is performed in high additive white Gaussian noise environments by processing sounds as images in the time-frequency plane. The technique creates audio streams that remove background noise from speech while preserving speech quality. Atomic decomposition is implemented by the matching pursuit algorithm using Gabor or gammatone atomic dictionaries. Gabor atoms were originally proposed as fundamental building blocks of speech; whereas, gammatone atoms closely resemble the human cochlear impulse response. Atomic decomposition creates a sparsely populated time-frequency vector referred to as weight space. The populated positions in weight space have amplitude weights that are proportional to localized energy in …


Flex-Ro: Design, Implementation, And Control Of Subassemblies For An Agricultural Robotic Platform, Jared Patrick Werner Nov 2016

Flex-Ro: Design, Implementation, And Control Of Subassemblies For An Agricultural Robotic Platform, Jared Patrick Werner

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

Automation technology in agriculture is growing, making agricultural robotics viable. Innovative field usable multi-purpose robotic platforms are needed for the successful progression of agricultural robotics. Furthermore, the field of agricultural robotics would benefit from a robotic platform design allowing for variable height, thus accommodating navigation throughout various crop growth stages. A variable height machine, Flex-Ro was developed to accommodate this feature. Multiple sub-assemblies were designed and implemented for Flex-Ro. An electronic control unit (ECU) enabled engine was used to power Flex-Ro. An embedded application program was developed to control engine speed using proprietary Controller Area Network (CAN) messages in conjunction …


Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara Nov 2016

Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Bench-scale anaerobic digesters were amended to elevated steady-state concentrations of triclosan (850 mg/kg) and triclocarban (150 mg/kg) using a synthetic feed. After more than 9 solids retention time (SRT) values of acclimatization, biomass from each digester (and a control digester that received no antimicrobials) was used to assess the toxicity of three antibiotics. Methane production rate was measured as a surrogate for activity in microcosms that received doses of antibiotics ranging from no-antibiotic to inhibitory concentrations. Biomass amended with triclocarban was more sensitive to tetracycline compared to the control indicating synergistic inhibitory effects between this antibiotic and triclocarban. In contrast, …


Anaerobic Digester Bioaugmentation Influences Quasi Steady State Performance And Microbial Community, Kaushik Venkiteshwaran, K. Milferstedt, J. Hamelin, Daniel Zitomer Nov 2016

Anaerobic Digester Bioaugmentation Influences Quasi Steady State Performance And Microbial Community, Kaushik Venkiteshwaran, K. Milferstedt, J. Hamelin, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Nine anaerobic digesters, each seeded with biomass from a different source, were operated identically and their quasi steady state function was compared. Subsequently, digesters were bioaugmented with a methanogenic culture previously shown to increase specific methanogenic activity. Before bioaugmentation, different seed biomass resulted in different quasi steady state function, with digesters clustering into three groups distinguished by methane (CH4) production. Digesters with similar functional performance contained similar archaeal communities based on clustering of Illumina sequence data of the V4V5 region of the 16S rRNA gene. High CH4 production correlated with neutral pH and high Methanosarcina abundance, whereas …


Amulet: An Energy-Efficient, Multi-Application Wearable Platform, Josiah Hester, Travis Peters, Tianlong Yun, Ronald Peterson, Joseph Skinner, Bhargav Golla, Kevin Storer, Steven Hearndon, Kevin Freeman, Sarah Lord, Ryan Halter, David Kotz, Jacob Sorber Nov 2016

Amulet: An Energy-Efficient, Multi-Application Wearable Platform, Josiah Hester, Travis Peters, Tianlong Yun, Ronald Peterson, Joseph Skinner, Bhargav Golla, Kevin Storer, Steven Hearndon, Kevin Freeman, Sarah Lord, Ryan Halter, David Kotz, Jacob Sorber

Dartmouth Scholarship

Wearable technology enables a range of exciting new applications in health, commerce, and beyond. For many important applications, wearables must have battery life measured in weeks or months, not hours and days as in most current devices. Our vision of wearable platforms aims for long battery life but with the flexibility and security to support multiple applications. To achieve long battery life with a workload comprising apps from multiple developers, these platforms must have robust mechanisms for app isolation and developer tools for optimizing resource usage.\r\n\r\nWe introduce the Amulet Platform for constrained wearable devices, which includes an ultra-low-power hardware architecture …


Bioaerosol Deposition On An Air-Conditioning Cooling Coil, Yan Wu, Ailu Chen, Irvan Luhung, Elliott T. Gall, Qingliang Cao, Victor Wei-Chung Chang, William W. Nazaroff Nov 2016

Bioaerosol Deposition On An Air-Conditioning Cooling Coil, Yan Wu, Ailu Chen, Irvan Luhung, Elliott T. Gall, Qingliang Cao, Victor Wei-Chung Chang, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

This study is concerned with the role of a fin-and-tube heat exchanger in modifying microbial indoor air quality. Specifically, depositional losses of ambient bioaerosols and particles onto dry (not cooled) and wet (cool) coil surfaces were measured for different airspeeds passing through the test coil. Total, bacterial and fungal DNA concentrations in condensate water produced by a wet coil were also quantified by means of fluorescent dsDNA-binding dye and qPCR assays. Results revealed that the deposition of bioaerosols and total particles is substantial on coil surfaces, especially when wet and cool. The average deposition fraction was 0.14 for total DNA, …


How Acoustics In California High Performance Schools Relate To Student Achievement, Devin K. Wong Nov 2016

How Acoustics In California High Performance Schools Relate To Student Achievement, Devin K. Wong

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

This research project seeks to determine if students attending K–12 schools meeting a minimum standard of high performance classroom conditions in the state of California do evidence higher scholastic achievement, based on publically available results on state-wide standardized tests. In three phases, a subset of 200+ schools applying for grants dedicated to building high performance schools over the past decade was correlated with an existing database of achievement scores for all public schools in California. The criteria utilized to specify high performance classrooms was provided by the California High Performance Initiative (HPI) Grant program. Academic achievement was evaluated on a …


Design, Fabrication And Characterization Of Low­ Power Gas Sensors Based On Organic-Inorganic Nano-Composition, Ayah Faeik Salim Abu Hani Nov 2016

Design, Fabrication And Characterization Of Low­ Power Gas Sensors Based On Organic-Inorganic Nano-Composition, Ayah Faeik Salim Abu Hani

Theses

Lower power consumption and higher performance are compelling demands in the electronic systems motivating the search for new materials, which are capable of fulfilling these demands. Recently, nanomaterial-based sensor technology has drawn considerable attention towards the development of sensing applications such as H2S gas sensors. Development of H2S gas sensors is crucial due to its extreme toxicity and damaging effects on both health and environment. This thesis aims to develop H2S gas sensors with enhanced sensitivity, flexibility, lower operating temperature, and high selectivity.

The proposed sensors present a contribution to the field of nano-electronics. They are designed based on the …


Fuzzy Expert Systems: A More Human-Based Approach For Sensorial Evaluation Of Coffee-Bean Attributes To Derive Quality Scoring, Javier A. Livio Nov 2016

Fuzzy Expert Systems: A More Human-Based Approach For Sensorial Evaluation Of Coffee-Bean Attributes To Derive Quality Scoring, Javier A. Livio

Theses and Dissertations

In the coffee industry, "cupping" is the process of sensorial evaluations of coffee beans, also known as Sample Evaluation. This process is done for three major reasons: to determine the actual sensory differences between coffee samples, to describe the flavors of the samples, and to determine preference of product. In totality, cupping targets the measurement of the coffee's quality related to fragrance, taste, and appearance which are expressed with a final numerical score. When cupping, the expert judge writes down the individual components' scores (fragrance, aftertaste, acidity, body, etc.) and ranks their intensities for reference. Despite the fact the cuppers …


Method For Fabricating Biocompatible Porous Titanium, B. Sonny Bal, Tieshu Huang, M. N. Rahaman Nov 2016

Method For Fabricating Biocompatible Porous Titanium, B. Sonny Bal, Tieshu Huang, M. N. Rahaman

Materials Science and Engineering Faculty Research & Creative Works

A method for fabricating porous metal constructs (such as porous Ti constructs) which may be used as implants in bone repair is disclosed. The method employs a new saltbath sintering process coupled with conventional powder metallurgy technology which is capable of fabricating porous metal constructs with controlled porosity and pore size having a lower production cost than conventional powder metallurgy methods.


Application Of An Artificial Neural Network To Predict Graduation Success At The United States Military Academy, Gene Lesinski, Steven Corns, Cihan H. Dagli Nov 2016

Application Of An Artificial Neural Network To Predict Graduation Success At The United States Military Academy, Gene Lesinski, Steven Corns, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents a neural network approach to classify student graduation status based upon selected academic, demographic, and other indicators. A multi-layer feedforward network with backpropagation learning is used as the model framework. The model is trained, tested, and validated using 5100 student samples with data compiled from admissions records and institutional research databases. Nine input variables consist of categorical and numeric data elements including: high school rank, high school quality, standardized test scores, high school faculty assessments, extra-curricular activity score, parent's education status, and time since high school graduation. These inputs and the multi-layer neural network model are used …


Combining Max-Min And Max-Max Approaches For Robust Sos Architecting, Hadi Farhangi, Dincer Konur, Cihan H. Dagli Nov 2016

Combining Max-Min And Max-Max Approaches For Robust Sos Architecting, Hadi Farhangi, Dincer Konur, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

A System of Systems (SoS) architecting problem requires creating a selection of systems in order to provide a set of capabilities. SoS architecting finds many applications in military/defense projects. In this paper, we study a multi-objective SoS architecting problem, where the cost of the architecture is minimized while its performance is maximized. The cost of the architecture is the summation of the costs of the systems to be included in the SoS. Similarly, the performance of the architecture is defined as the sum of the performance of the capabilities, where the performance of a capability is the sum of the …


Entity Resolution Using Convolutional Neural Network, Ram Deepak Gottapu, Cihan H. Dagli, Bharami Ali Nov 2016

Entity Resolution Using Convolutional Neural Network, Ram Deepak Gottapu, Cihan H. Dagli, Bharami Ali

Engineering Management and Systems Engineering Faculty Research & Creative Works

Entity resolution is an important application in field of data cleaning. Standard approaches like deterministic methods and probabilistic methods are generally used for this purpose. Many new approaches using single layer perceptron, crowdsourcing etc. are developed to improve the efficiency and also to reduce the time of entity resolution. The approaches used for this purpose also depend on the type of dataset, labeled or unlabeled. This paper presents a new method for labeled data which uses single layered convolutional neural network to perform entity resolution. It also describes how crowdsourcing can be used with the output of the convolutional neural …


Evaluating Forecasting Methods By Considering Different Accuracy Measures, Nijat Mehdiyev, David Lee Enke, Peter Fettke, Peter Loos Nov 2016

Evaluating Forecasting Methods By Considering Different Accuracy Measures, Nijat Mehdiyev, David Lee Enke, Peter Fettke, Peter Loos

Engineering Management and Systems Engineering Faculty Research & Creative Works

Choosing the appropriate forecasting technique to employ is a challenging issue and requires a comprehensive analysis of empirical results. Recent research findings reveal that the performance evaluation of forecasting models depends on the accuracy measures adopted. Some methods indicate superior performance when error based metrics are used, while others perform better when precision values are adopted as accuracy measures. As scholars tend to use a smaller subset of accuracy metrics to assess the performance of forecasting models, there is a need for a concept of multiple accuracy dimensions to assure the robustness of evaluation. Therefore, the main purpose of this …


Multiobjective System Of Systems Architecting With Performance Improvement Funds, Hadi Farhangi, Dincer Konur, Cihan H. Dagli Nov 2016

Multiobjective System Of Systems Architecting With Performance Improvement Funds, Hadi Farhangi, Dincer Konur, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

A System of Systems architecting problem aims to determine a selection of systems, which are capable of providing a set of desired capabilities. A SoS architect usually has multiple objectives in generating efficient architectures such as minimization of the total cost and maximization the overall performance of the SoS. This study formulates a biobjective SoS architecting problem with these two objectives. Here, we consider that, by allocating funds to the systems, the SoS architect can improve the performance of the capabilities the systems can provide. The resulting architecting problem is a biobjective mixed-integer linear programming model. Specifically, the system selection …


Shape Analysis Of Traffic Flow Curves Using A Hybrid Computational Analysis, Wasim Irshad Kayani, Shikhar P. Acharya, Ivan G. Guardiola, Donald C. Wunsch, B. Schumacher, Isaac Wagner-Muns Nov 2016

Shape Analysis Of Traffic Flow Curves Using A Hybrid Computational Analysis, Wasim Irshad Kayani, Shikhar P. Acharya, Ivan G. Guardiola, Donald C. Wunsch, B. Schumacher, Isaac Wagner-Muns

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper highlights and validates the use of shape analysis using Mathematical Morphology tools as a means to develop meaningful clustering of historical data. Furthermore, through clustering more appropriate grouping can be accomplished that can result in the better parameterization or estimation of models. This results in more effective prediction model development. Hence, in an effort to highlight this within the research herein, a Back-Propagation Neural Network is used to validate the classification achieved through the employment of MM tools. Specifically, the Granulometric Size Distribution (GSD) is used to achieve clustering of daily traffic flow patterns based solely on their …


Application Of Neural Network In Shop Floor Quality Control In A Make To Order Business, Rajkamal Kesharwani, Cihan H. Dagli, Zeyi Sun Nov 2016

Application Of Neural Network In Shop Floor Quality Control In A Make To Order Business, Rajkamal Kesharwani, Cihan H. Dagli, Zeyi Sun

Engineering Management and Systems Engineering Faculty Research & Creative Works

A make to order business has to produce the products that are customized to the customer's current need. The customization can be realized by assembling different standard parts with various 'configurations'. The oil field service industry is a typical example where most products produced are cylindrical assemblies made up of standard parts customized in their size, material specifications, coating specifications, and threading suited for the particular load rating and environment. As business cycles go up and down, hiring and firing of personnel is the routine of the day. Thus, it is very hard to keep experienced inspectors due to high …


Performance Of Continuous Concrete Slabs Reinforced With Hybrid Steel-Basalt Bars, Mohammad Sohayeb Akiel Nov 2016

Performance Of Continuous Concrete Slabs Reinforced With Hybrid Steel-Basalt Bars, Mohammad Sohayeb Akiel

Theses

Continuous steel-reinforced concrete structures are vulnerable to corrosion

Damage when exposed to harsh environment. Although replacing conventional steel entirely with basalt fiber-reinforced polymer (BFRP) bars can eliminate corrosion problems, the lower modulus of elasticity of BFRP would reduce serviceability of the structure. The use of hybrid steel-BFRP bars rather than BFRP bars only has a potential to improve the serviceability of continuous concrete

Structures without reducing the deformation capacity. Through experimental testing and numerical simulation, this work aims to examine the structural behavior of two-span concrete specimens internally reinforced with BFRP or hybrid steel-BFRP bars.

A total of 12 two-span …


An Islanding Detection Method For Micro-Grids With Grid-Connected And Islanded Capability, Hasna Mubarak Saleh Ai Seiari Nov 2016

An Islanding Detection Method For Micro-Grids With Grid-Connected And Islanded Capability, Hasna Mubarak Saleh Ai Seiari

Theses

With the increasing prevalence of renewable energy and distributed generation (DG) in distribution systems, micro-grids are becoming more popular and an attractive option for enhancing system operation and reliability. This can be attributed to the micro-grid ability to operate in both connected and disconnected modes. Equally important, micro-grids are the best solution to meet the increasing demand of electric power in a cost effective manner due to the close proximity to the load demand and thus minimizing system losses. Islanding detection methods have been proposed for inverter based distributed generation with only grid-connected capability. Micro-grids are composed of DGs that …


Preparation Of Nano-Size Ceramic Membrane From Industrial Waste, Shereen K. Amin, Mai H. Roushdy, Chakinaz Aly El-Sherbiny, Heba Mohamed Abdallah, Magdi F. Abadir Nov 2016

Preparation Of Nano-Size Ceramic Membrane From Industrial Waste, Shereen K. Amin, Mai H. Roushdy, Chakinaz Aly El-Sherbiny, Heba Mohamed Abdallah, Magdi F. Abadir

Chemical Engineering

Industrial ceramic wastes are becoming an increasing problem worldwide. Recently, this problem has attracted social concern due to the growing amounts of waste despite the measures and precautions that have been taken worldwide aiming at managing such wastes. One promising solution that has been recently researched consists incorporating such wastes in ceramic bodies which besides minimizing the waste load often improve the quality of the ceramic body. Roller kilns used in the production of ceramic tiles are routinely ground to remove traces of contamination. The fine ground powder is usually discarded as a useless waste. In the present paper, the …


Variable Rate Irrigation For Mining Undepleted Soil Water, Derek M. Heeren, Tsz Him Lo, Joe D. Luck, J. Burdette Barker, Derrel Martin, Luciano Mateos Nov 2016

Variable Rate Irrigation For Mining Undepleted Soil Water, Derek M. Heeren, Tsz Him Lo, Joe D. Luck, J. Burdette Barker, Derrel Martin, Luciano Mateos

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Variable Rate Irrigation (VRI) offers the potential to improve irrigation efficiency by accounting for spatial variability in soil properties and water-holding capacity. This study explores the hypothesis that under conventional uniform irrigation, portions of fields with higher root zone available water capacity (R) often retain undepleted soil water. By developing prescription maps based on management allowable depletion (MAD), VRI can strategically “mine” this undepleted soil water, thereby reducing pumping requirements without negatively affecting crop performance.

Multiple tools for identifying spatial variability—including yield maps, digital elevation models, apparent electrical conductivity (ECa), soil sampling, remote sensing imagery, and cosmic ray probes—were evaluated …


Experimental Investigation Of Co2 Transport Through Combined Membrane Absorber And Regenerator, Nima Mohammadrasool Atbaei Nov 2016

Experimental Investigation Of Co2 Transport Through Combined Membrane Absorber And Regenerator, Nima Mohammadrasool Atbaei

Chemical and Petroleum Engineering Theses

Greenhouse gases such as carbon dioxide have been known to contribute significantly to global warming, which in turn has resulted in serious global environmental problems. Carbon dioxide is the main gaseous contaminant in the atmosphere, representing about 80% of greenhouse gases. It is reported that industry and power plants using fossil fuels such as coal-combustion power generators produce half of the CO2 emissions. These emissions create the need for low energy-consumption, and efficient technologies for the capture and removal of CO2 from gas mixtures produced by industrial sources.

Conventional gas absorption processes for the removal of CO2 …


Distribution Of Mean Kinetic Energy Around An Isolated Wind Turbine And A Characteristic Wind Turbine Of A Very Large Wind Farm, Gerard Cortina, Marc Calaf, Raul Bayoan Cal Nov 2016

Distribution Of Mean Kinetic Energy Around An Isolated Wind Turbine And A Characteristic Wind Turbine Of A Very Large Wind Farm, Gerard Cortina, Marc Calaf, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

An isolated wind turbine and a very large wind farm are introduced into large-eddy simulations of an atmospheric boundary layer. The atmospheric flow is forced with a constant geostrophic wind and a time-varying surface temperature extracted from a selected period of the CASES-99 field experiment. A control volume approach is used to directly compare the transfer of mean kinetic energy around a characteristic wind turbine throughout a diurnal cycle considering both scenarios. For the very large wind farm case, results illustrate that the recovery of mean kinetic energy around a wind turbine is dominated by the vertical flux, regardless of …