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Articles 91 - 120 of 1954

Full-Text Articles in Other Civil and Environmental Engineering

A Methodology To Optimize Site-Specific Field Capacity And Irrigation Thresholds, Hemendra Kumar, Puneet Srivastava, Jasmeet Lamba, Bruno Lena, Efstathios Diamantopoulos, Brenda Ortiz, Bijoychandra Takhellambam, Guilherme Morata, Luca Bondesan Jan 2023

A Methodology To Optimize Site-Specific Field Capacity And Irrigation Thresholds, Hemendra Kumar, Puneet Srivastava, Jasmeet Lamba, Bruno Lena, Efstathios Diamantopoulos, Brenda Ortiz, Bijoychandra Takhellambam, Guilherme Morata, Luca Bondesan

Department of Biological Systems Engineering: Papers and Publications

The determination of field capacity (FC), irrigation thresholds, and irrigation amounts is characterized by site-specific soil hydraulic properties (SHPs). This study, conducted in two zones (zone 1 and zone 2) delineated based on soil, topography, and historical crop yield in Alabama (USA), focused on determining zone-specific FC using negligible drainage flux (qfc) criterion. The HYDRUS-1D model was used to optimize zone-specific SHPs using measured soil matric potential (h). The zone-specific FCs were determined using optimized and raw SHPs at 0.01 cm/day as qfc. The results showed that the optimized FC at qfc …


Estimating Battery Size Requirements For Tractor Electrification Of Row-Crop Planting Operations, Cheetown Liew, Andrew Donesky, Mark Freyhof, Ian Tempelmeyer, Santosh Kumar Pitla Jan 2023

Estimating Battery Size Requirements For Tractor Electrification Of Row-Crop Planting Operations, Cheetown Liew, Andrew Donesky, Mark Freyhof, Ian Tempelmeyer, Santosh Kumar Pitla

Department of Biological Systems Engineering: Papers and Publications

Power sources such as batteries, used for both on-road and off-road vehicles, are advancing at a rapid pace. Electric batteries are becoming more power dense, thus allowing them to be used as a power source to replace previous diesel or gasoline-powered systems. Efforts are underway to transition off-road agricultural vehicles from Internal Combustion Engine (ICE) vehicles to electric vehicles (EVs); however, the energy requirements of typical agricultural field operations need to be fully understood before such a transition can occur. Theoretical prediction equations available in the American Society of Agricultural and Biological Engineers (ASABE) standards or the use of engine …


Hdd Dataset: Optimising Retrofitted Insulation For Irish Residential Building Walls, Rakshit D. Muddu, Aimee Byrne, Anthony James Robinson Jan 2023

Hdd Dataset: Optimising Retrofitted Insulation For Irish Residential Building Walls, Rakshit D. Muddu, Aimee Byrne, Anthony James Robinson

Datasets

In this study, a thermal-economic analysis was conducted to determine the optimum insulation thickness of retrofitted insulation walls in different regions in Ireland. This was based on the Heating Degree Day method (HDD). This dataset contains optimum insulation thickness, payback period, cost savings and carbon emission for all 25 counties in the Republic of Ireland


Survey Data: Optimising Retrofitted Insulation For Irish Residential Building Walls, Rakshit D. Muddu, Aimee Byrne, Anthony Robinson Dr. Jan 2023

Survey Data: Optimising Retrofitted Insulation For Irish Residential Building Walls, Rakshit D. Muddu, Aimee Byrne, Anthony Robinson Dr.

Datasets

A survey was conducted to determine the preferred set point temperature and heating pattern among Irish households. The survey was sent to 237 people living across Ireland, out of which 32 respondents skipped the survey and 9 surveys were found to be incomplete. Amongst the counties in Ireland 71.1% respondents were from Dublin, 6.34% from Kildare, 5% from Meath, 5% from Wicklow and in all the remaining counties response rate was below 2%. Part 1: This section of the survey recorded information regarding characteristics of the building such as house type, wall type, insulation type, period the house was built. …


Investigating The Change In Pavement Cracking Data Due To Automated Data Collection Methods, Faisal Quibria Chowdhury Jan 2023

Investigating The Change In Pavement Cracking Data Due To Automated Data Collection Methods, Faisal Quibria Chowdhury

Graduate Theses, Dissertations, and Problem Reports

Data collection on pavement surface cracks is crucial for the state Departments of Transportation (DOTs) to make informed decisions on maintenance, repair, and rehabilitation (MR&R) activities. The collected cracking data is translated into a pavement performance indicator to assess the condition of pavement sections and identify MR&R needs based on predetermined threshold values set by the state DOTs. State DOTs have transitioned from manual to automated data collection as automation offers many advantages over manual data collection, such as improved data collection rates, efficiency, cost reduction, and safety. As the state DOTs have integrated automated data into the pavement performance …


Application Of Metagenomic And Molecular Microbiology Techniques To Elucidate Sources Of Fecal Pollution And Anthropogenic Antibiotic Resistance Genes To Surface Water: A Step Towards A “One Health” Approach To Watershed Management, Mehedi Hasan Tarek Jan 2023

Application Of Metagenomic And Molecular Microbiology Techniques To Elucidate Sources Of Fecal Pollution And Anthropogenic Antibiotic Resistance Genes To Surface Water: A Step Towards A “One Health” Approach To Watershed Management, Mehedi Hasan Tarek

Graduate Theses, Dissertations, and Problem Reports

The use of fecal indicator bacteria, such as Escherichia coli, is a widely established regulatory and monitoring practice to detect surface water contamination associated with fecal pollution. However, the detection or quantification of fecal indicator bacteria alone does not accurately inform the sources of fecal pollution. The development of molecular and metagenomic methods that target the DNA of microorganisms has resulted in a host of new tools for monitoring fecal pollution and its sources, as well as for understanding emerging microbial threats, such as antimicrobial resistance. Antimicrobial resistance is a critical “One Health” challenge presenting a high risk to …


Osc-Co2: Coattention And Cosegmentation Framework For Plant State Change With Multiple Features, Rubi Quiñones, Ashok Samal, Sruti Das Choudhury, Francisco Muñoz-Arriola Jan 2023

Osc-Co2: Coattention And Cosegmentation Framework For Plant State Change With Multiple Features, Rubi Quiñones, Ashok Samal, Sruti Das Choudhury, Francisco Muñoz-Arriola

Department of Biological Systems Engineering: Papers and Publications

Cosegmentation and coattention are extensions of traditional segmentation methods aimed at detecting a common object (or objects) in a group of images. Current cosegmentation and coattention methods are ineffective for objects, such as plants, that change their morphological state while being captured in different modalities and views. The Object State Change using Coattention-Cosegmentation (OSC-CO2) is an end-to-end unsupervised deep-learning framework that enhances traditional segmentation techniques, processing, analyzing, selecting, and combining suitable segmentation results that may contain most of our target object’s pixels, and then displaying a final segmented image. The framework leverages coattention-based convolutional neural networks (CNNs) and …


Clim4omics: A Geospatially Comprehensive Climate And Multi-Omics Database For Maize Phenotype Predictability In The United States And Canada, Parisa Sarzaeim, Francisco Muñoz-Arriola, Diego Jarquin, Hasnat Aslam, Natalia De Leon Gatti Jan 2023

Clim4omics: A Geospatially Comprehensive Climate And Multi-Omics Database For Maize Phenotype Predictability In The United States And Canada, Parisa Sarzaeim, Francisco Muñoz-Arriola, Diego Jarquin, Hasnat Aslam, Natalia De Leon Gatti

Department of Biological Systems Engineering: Papers and Publications

The performance of numerical, statistical, and data-driven diagnostic and predictive crop production modeling relies heavily on data quality for input and calibration or validation processes. This study presents a comprehensive database and the analytics used to consolidate it as a homogeneous, consistent, multidimensional genotype, phenotypic, and environmental database for maize phenotype modeling, diagnostics, and prediction. The data used are obtained from the Genomes to Fields (G2F) initiative, which provides multiyear genomic (G), environmental (E), and phenotypic (P) datasets that can be used to train and test crop growth models to understand the genotype by environment (GxE) interaction phenomenon. A particular …


Evaluating Management Zones And Crop-Sensing Relationships For Improved Irrigated Maize Nitrogen Management, Joel D. Crowther, John Parrish, Joe Luck, Richard Ferguson Jan 2023

Evaluating Management Zones And Crop-Sensing Relationships For Improved Irrigated Maize Nitrogen Management, Joel D. Crowther, John Parrish, Joe Luck, Richard Ferguson

Department of Biological Systems Engineering: Papers and Publications

Active crop canopy sensors and management zones (MZ) are two methods of directing variable-rate, in-season nitrogen (N) fertilizer applications in maize (Zea mays L.). Researchers have suggested that integrating these two approaches may result in improved performance of sensor-based N application algorithms through increased N use efficiency and profitability. The objectives of this research study were to (1) identify soil and topographic variables that are related to in-season canopy reflectance and yield for soil-based MZ delineation and (2) determine if delineated MZ can identify areas with differential crop response to N fertilizer. N ramp blocks were placed end-to-end in field-length …


Agricultural Machinery Operator Monitoring System (Ag-Oms): A Machine Learning Approach For Real-Time Operator Safety Assessment, Terence Irumva, Herve Mwunguzi, Santosh Pitla, Bethany Lowndes, Aaron Yoder, Ka-Chun Siu Jan 2023

Agricultural Machinery Operator Monitoring System (Ag-Oms): A Machine Learning Approach For Real-Time Operator Safety Assessment, Terence Irumva, Herve Mwunguzi, Santosh Pitla, Bethany Lowndes, Aaron Yoder, Ka-Chun Siu

Department of Biological Systems Engineering: Papers and Publications

The 2015 CS-CASH (Central States Center for Agricultural Safety and Health, 2015) Injury Surveillance Surveys showed that around 19% of injuries to agricultural producers are related to tractors or large agricultural machinery, yet only a limited number of studies are found that address tools and methods for monitoring safety behaviors of agricultural machinery operators in real-time. The current safety behavior monitoring approaches require an in-person presence, which can be both time- and cost-inefficient, and the other available methods lack a feedback element to alert operators in realtime. As a result, the research presented in this study aimed to develop an …


Evaluation Of Cytocompatability And Safety Of Nerve Retraction Compounds For Local Disc Denervation To Treat Disc-Associated Low Back Pain, Fei San Lee, Uyen N. Nguyen, Rebecca A. Wachs Jan 2023

Evaluation Of Cytocompatability And Safety Of Nerve Retraction Compounds For Local Disc Denervation To Treat Disc-Associated Low Back Pain, Fei San Lee, Uyen N. Nguyen, Rebecca A. Wachs

Department of Biological Systems Engineering: Papers and Publications

Low back pain (LBP) is the leading cause of disability worldwide. Aberrant nerve growth into intervertebral discs is a common pathological feature of disc-associated LBP. Current treatments rely on short-term solutions using opioids or anti-inflammatory prescriptions which can lead to addiction and side effects, respectively. We hypothesize that removal of aberrant nerve fibers in the disc using nerve retraction compounds can alleviate discassociated LBP. We performed screening of nerve retraction compounds using adult rat dorsal root ganglia (DRG) explant culture in hydrogels to mimic disc innervation in vitro. Capsaicin, known to induce nerve retraction, was used as a positive control …


Goniometer In The Air: Enabling Brdf Measurement Of Crop Canopies Using A Cable-Suspended Plant Phenotyping Platform, Geng Bai, Yufeng Ge, Bryan Leavitt, John Gamon, David Scoby Jan 2023

Goniometer In The Air: Enabling Brdf Measurement Of Crop Canopies Using A Cable-Suspended Plant Phenotyping Platform, Geng Bai, Yufeng Ge, Bryan Leavitt, John Gamon, David Scoby

Department of Biological Systems Engineering: Papers and Publications

The Bidirectional Reflectance Distribution Function (BRDF) quantifies the distribution of the spectral reflectance of a target surface at various viewing and illumination angles. In-field measurement of the BRDF of vegetation canopies improves the characterization of offnadir measurements and informs radiative transfer models of canopy reflectance, where the Lambertian assumption does not hold. However, current field goniometers are unable to measure BRDF efficiently, especially for tall vegetation across the growing season because of the limitations of clearance, field accessibility, and flexibility of the sensor field of view. In this study, we explored the potential of using a large-scale cable-suspended field phenotyping …


Crop Stress Sensing And Plant Phenotyping Systems: A Review, Geng Bai, Yufeng Ge Jan 2023

Crop Stress Sensing And Plant Phenotyping Systems: A Review, Geng Bai, Yufeng Ge

Department of Biological Systems Engineering: Papers and Publications

Enhancing resource use efficiency in agricultural field management and breeding high-performance crop varieties are crucial approaches for securing crop yield and mitigating negative environmental impact of crop production. Crop stress sensing and plant phenotyping systems are integral to variable-rate (VR) field management and high-throughput plant phenotyping (HTPP), with both sharing similarities in hardware and data processing techniques. Crop stress sensing systems for VR field management have been studied for decades, aiming to establish more sustainable management practices. Concurrently, significant advancements in HTPP system development have provided a technological foundation for reducing conventional phenotyping costs. In this paper, we present a …


Mixing, Metabolism, And Climate Change: A Modeling Case Study Of A Shallow Hypereutrophic, Polymictic Lake, Benjamin C. Reuss Jan 2023

Mixing, Metabolism, And Climate Change: A Modeling Case Study Of A Shallow Hypereutrophic, Polymictic Lake, Benjamin C. Reuss

Dissertations, Master's Theses and Master's Reports

Globally, lakes are sites of significant carbon cycling, respiring an estimated 0.07 to 0.15 Pg as CO2 and sequestering 0.03 to 0.07 Pg C in sediments annually. These processes can be affected by nutrient availability, with seasonal mixing regulating nutrient transport in monomictic and dimictic systems. However, the effect of intermittent mixing on ecosystem production in polymictic systems has been much less studied. The timing and frequency of lake mixing are expected to be altered by climate change, which has the potential to impact nutrient transport. The first chapter of this thesis introduces lake mixing dynamics and indices of mixing. …


Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer Jan 2023

Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer

Theses and Dissertations (Comprehensive)

Phosphorus (P) is a fundamental element necessary for all life forms and a key component in the fertilizer industry. Meanwhile, the excessive load of P to water bodies due to human activities has the potential to promote eutrophication. Wastewater treatment plants remove P either biologically or chemically and produce P rich sludge which could be a potential renewable source for P. At present, commercial technologies exist for P recovery from biological wastewater sludge. However, P recovery from chemical sludge particularly iron(III)-phosphate (Fe-P) sludge generated in chemical P removal plants that use iron(III) salts remains a challenge.

This study explored, in …


Complab V1.0: A Scalable Pore-Scale Model For Flow, Biogeochemistry, Microbial Metabolism, And Biofilm Dynamics, Heewon Jung, Hyun-Seob Song, Christof Meile Jan 2023

Complab V1.0: A Scalable Pore-Scale Model For Flow, Biogeochemistry, Microbial Metabolism, And Biofilm Dynamics, Heewon Jung, Hyun-Seob Song, Christof Meile

Department of Biological Systems Engineering: Papers and Publications

Microbial activity and chemical reactions in porous media depend on the local conditions at the pore scale and can involve complex feedback with fluid flow and mass transport. We present a modeling framework that quantitatively accounts for the interactions between the bio(geo)chemical and physical processes and that can integrate genome-scale microbial metabolic information into a dynamically changing, spatially explicit representation of environmental conditions. The model couples a lattice Boltzmann implementation of Navier–Stokes (flow) and advection–diffusion-reaction (mass conservation) equations. Reaction formulations can include both kinetic rate expressions and flux balance analysis, thereby integrating reactive transport modeling and systems biology. We also …


The Combined Impact Of Redcedar Encroachment And Climate Change On Water Resources In The Nebraska Sand Hills, Yaser Kishawi, Aaron R. Mittelstet, Zablon Adane, Nawaraj Shrestha, Paolo Nasta Dec 2022

The Combined Impact Of Redcedar Encroachment And Climate Change On Water Resources In The Nebraska Sand Hills, Yaser Kishawi, Aaron R. Mittelstet, Zablon Adane, Nawaraj Shrestha, Paolo Nasta

Department of Biological Systems Engineering: Papers and Publications

The Nebraska Sand Hills (NSH) is considered a major recharge zone for the High Plains Aquifer in the central United States. The uncontrolled expansion of the eastern redcedar (Juniperus Virginiana) under climate warming is posing threats to surface water and groundwater resources. The combined impact of land use and climate change on the water balance in the Upper Middle Loup River watershed (4,954 km2) in the NSH was evaluated by simulating different combination of model scenarios using the Soil Water Assessment Tool (SWAT) model. A total of 222 climate models were ranked according to the aridity …


Evaluation For Using Expended Bioelectrochemical Systems As Soil Amendments For Improved Corn Plant Growth And A Drought Resistant Soil., Jackson Lee Sauers Dec 2022

Evaluation For Using Expended Bioelectrochemical Systems As Soil Amendments For Improved Corn Plant Growth And A Drought Resistant Soil., Jackson Lee Sauers

Theses and Dissertations

A long-held practice is to mix agricultural soil with a soil amendment to improve growing conditions in crops. A common soil amendment is biosolids produced from both municipal and dairy wastewater due to the macro- and micronutrients within it. Both the agricultural and wastewater industries are participating in the Circular Economy concept (CEC). Two experiments explored using expended bioelectrochemical systems (BES) that treated either synthetic dairy wastewater (DWW) or synthetic municipal wastewater (SWW) as soil amendments to improve corn plant growth when treated with three different nutrient treatments: 100%- 50%- and 0% Hoagland Nutrient Solutions. Biochar and used terracotta clay …


Estimation Of Cotton Canopy Parameters Based On Unmanned Aerial Vehicle (Uav) Oblique Photography, Jinyong Wu, Sheng Wen, Yubin Lan, Xuanchun Yin, Jiantao Zhang, Yufeng Ge Dec 2022

Estimation Of Cotton Canopy Parameters Based On Unmanned Aerial Vehicle (Uav) Oblique Photography, Jinyong Wu, Sheng Wen, Yubin Lan, Xuanchun Yin, Jiantao Zhang, Yufeng Ge

Department of Biological Systems Engineering: Papers and Publications

Background: The technology of cotton defoliation is essential for mechanical cotton harvesting. Agricultural unmanned aerial vehicle (UAV) spraying has the advantages of low cost, high efficiency and no mechanical damage to cotton and has been favored and widely used by cotton planters in China. However, there are also some problems of low cotton defoliation rates and high impurity rates caused by unclear spraying amounts of cotton defoliants. The chemical rate recommendation and application should be based upon crop canopy volume rather than on land area. Plant height and leaf area index (LAI) is directly connected to plant canopy structure. …


Comparative Study Of Differentiating Human Pluripotent Stem Cells Into Vascular Smooth Muscle Cells In Hydrogel-Based Culture Methods, Qing Liu, Zhen Liu, Hongyu Gu, Yuxia Ge, Xuesheng Wu, Fuxing Zuo, Qian Du, Yuguo Lei, Zhanqi Wang, Haishuang Lin Dec 2022

Comparative Study Of Differentiating Human Pluripotent Stem Cells Into Vascular Smooth Muscle Cells In Hydrogel-Based Culture Methods, Qing Liu, Zhen Liu, Hongyu Gu, Yuxia Ge, Xuesheng Wu, Fuxing Zuo, Qian Du, Yuguo Lei, Zhanqi Wang, Haishuang Lin

Department of Biological Systems Engineering: Papers and Publications

Vascular smooth muscle cells (VSMCs), which provides structural integrity and regulates the diameter of vasculature, are of great potential for modeling vascular-associated diseases and tissue engineering. Here, we presented a detailed comparison of differentiating human pluripotent stem cells (hPSCs) into VSMCs (hPSCs-VSMCs) in four different culture methods, including 2-dimensional (2D) culture, 3-dimensional (3D) PNIPAAm-PEG hydrogel culture, 3-dimensional (3D) alginate hydrogel culture, and transferring 3- dimensional alginate hydrogel culture to 2-dimensional (2D) culture. Both hydrogel-based culture methods could mimic in vivo microenvironment to protect cells from shear force, and avoid cells agglomeration, resulting in the extremely high culture efficiency (e.g., high …


Behavior Of Completely Automated Evapotranspiration Estimation (Eemetric), Atiqullah Atif Dec 2022

Behavior Of Completely Automated Evapotranspiration Estimation (Eemetric), Atiqullah Atif

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Evapotranspiration (ET) is the second-largest component in the water balance equation, globally consuming 70% of the earth’s annual precipitation. Accurate and consistent estimation of ET is essential for ensuring water resources sustainability, proper management, planning, and regulations of water resources. Though a 100% accurate estimation of ET may not be feasible with the current technology, there are proven techniques that give us estimates of ET we can heavily rely on. Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) is a widely used surface energy balance model that produces relatively accurate ET maps utilizing remote sensing data and requires skilled …


Fundamental Investigation Of Interaction Between Moisture And Asphalt-Aggregate Systems, Rui Xiao Dec 2022

Fundamental Investigation Of Interaction Between Moisture And Asphalt-Aggregate Systems, Rui Xiao

Doctoral Dissertations

Moisture-induced damage is one of the most common forms of flexible pavement distress which directly causes or exacerbates pavement failure. The intrusion of moisture into the asphalt pavements reduces the overall mechanical properties of the locking structures and gives rise to one or more of the visible forms of distress such as raveling, stripping, permanent deformation and fatigue cracking. This doctoral study is aimed at understanding the detrimental action of water on the asphalt-aggregate systems and the damage mechanism by multi-technique investigation. A thermodynamics framework was considered to characterize the properties of asphalt mix ingredients as well as the engineering …


The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr. Dec 2022

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …


Erosion And Resuspension Of Cohesive Sediments In Coastal Louisiana, Laith Qasem Shamaileh Dec 2022

Erosion And Resuspension Of Cohesive Sediments In Coastal Louisiana, Laith Qasem Shamaileh

University of New Orleans Theses and Dissertations

The research presented in this study is motivated by the need to improve the predictions of cohesive sediment erosion and subsequent transport. In addition, the knowledge of the geotechnical engineering soil properties related to the erosion of sediments in coastal Louisiana has broad implications as these properties are used in transport models guiding the current restoration efforts. The erosion measuring device used in the study is the Cheng-Han Tasi and Wilbert Lick Shaker. Previous studies have been conducted before using the Shaker, but challenges with the calibration of the shear stress hampered the resuspension results produced by the Shaker. Therefore, …


Empirical Fragility Functions And Numerical Parametric Study For Buckling Of Steel Grain Bins Under High Wind Loads, Andrew Ruder Dec 2022

Empirical Fragility Functions And Numerical Parametric Study For Buckling Of Steel Grain Bins Under High Wind Loads, Andrew Ruder

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

While rural infrastructure is critical to the agricultural industry, it has been historically more susceptible to damage and slower to recover following natural disasters than its urban and suburban counterparts. This has been made evident most recently by the events of the August 10, 2020, derecho in which rural regions in Iowa were among the hardest hit areas with sustained windspeeds exceeding 120 mph. Among the most frequently damaged structures in this event were corrugated steel grain bins, which farmers and co-ops use to dry and store certain commodities. Unlike most other critical structures, steel grain bins are not designed …


Project Selection In Facility And Infrastructure Maintenance Organizations, Bayram M. Kurbanov Dec 2022

Project Selection In Facility And Infrastructure Maintenance Organizations, Bayram M. Kurbanov

Theses and Dissertations

The current Air Force Civil Engineer Center (AFCEC) built infrastructure Facility Sustainment Restoration and Modernization (FSRM) portfolio management methodology results in an unbalanced project portfolio. The consequence of this unbalance is that majority of the funding goes towards buildings on the flightline and Facility Support Services activities do not get adequate funding which leads to further deterioration of those facilities. This research investigates whether decision support framework based on Value-Focused Thinking (VFT) process yields better project selection outcomes for facility and infrastructure maintenance organizations. To accomplish that, the investigation focuses on understanding current AFCEC decision support methodology, building an alternative …


Evaluation Of Swelling Pressure And Shear Strength Of Inorganic Microfiber-Reinforced Bentonite For The Engineered Barrier System, Jose Maria Ferdinand Victoria Calaunan Dec 2022

Evaluation Of Swelling Pressure And Shear Strength Of Inorganic Microfiber-Reinforced Bentonite For The Engineered Barrier System, Jose Maria Ferdinand Victoria Calaunan

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nowadays, the permanent disposal of high-level radioactive waste materials has been a primary concern in several countries. The deep geological repository, being the preferred disposal method across the globe, utilizes a network of engineered barriers to prevent the radioactive material from spreading throughout the facility and harming the natural environment. Part of this engineered barrier system (EBS) is the buffer material, which essential function is holding the radioactive waste-containing canister in place. However, the potential generation of desiccation cracks in this buffer material is imminent due to the heat emitted from the radioactive waste. Knowing the capability of inorganic fibers …


Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong Dec 2022

Measuring Acoustic Nonlinearity Of Elastic Materials Using Thermal Modulation Of Ultrasonic Waves, Bibo Zhong

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nonlinear acoustic techniques have been used to determine the nonlinear properties of materials. Existing methods either require complex equipment to measure absolute nonlinear coefficients or can only be used on laboratory-sized specimens. A recently developed thermal modulation method addresses the limitations of existing methods, but further theoretical analysis and validation are required.

In this dissertation, theoretical analyses were first conducted to study the mechanically and thermally induced acoustoelastic effect. Beginning with the wave equation, the relationship of the ultrasonic wave velocity with respect to mechanical strain and the thermal strain was derived in detail. These analyses provided theoretical support for …


Active Rheological And Stiffening Control Of Cementitious Systems For Additive Manufacturing, Abdul Basit Peerzada Dec 2022

Active Rheological And Stiffening Control Of Cementitious Systems For Additive Manufacturing, Abdul Basit Peerzada

All Dissertations

Technological advancements and automation in the last two decades have made additive manufacturing of cementitious systems a reality. Among all the additive manufacturing techniques used for cementitious materials, layer-by-layer extrusion-based printing is the most used technique. For a layer-by-layer printing process, the requirements of cementitious materials vary from those of a conventional construction process. Typically, the cementitious materials are pumped to a print head using a positive-displacement pump. The pumpability of the cementitious material for a specific pumping system depends on its rheological properties. For effective pumping, the yield stress and plastic viscosity of a cementitious system should be low. …


Mango Surface Color Features Measurement Using Digital Image Processing, Md Towfiqur Rahman, Goutom Kumar, Md Abdul Momin Dec 2022

Mango Surface Color Features Measurement Using Digital Image Processing, Md Towfiqur Rahman, Goutom Kumar, Md Abdul Momin

Department of Biological Systems Engineering: Papers and Publications

Summary

Postharvest processing of agricultural produce is still done the conventional way in Bangladesh. Manual grading of agricultural produce, especially fruits and vegetables, is laborious and costly due to acute shortage of labor during the peak season, as well as difficulty maintaining the product quality. Machine vision system (MVS) applications are widely used nowadays as a non-destructive and cost-effective technology for automatically grading and sorting large volumes of produce in the packing house according to size, shape, color, texture, and surface defects. In this study, a simple MVS was constructed measuring different color features of mango fruit surface as a …