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Civil and Environmental Engineering

2022

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Articles 1 - 30 of 1673

Full-Text Articles in Engineering

Faceted Nanomaterial Synthesis, Characterizations And Applications In Reactive Electrochemical Membrane Filtration, Qingquan Ma Dec 2022

Faceted Nanomaterial Synthesis, Characterizations And Applications In Reactive Electrochemical Membrane Filtration, Qingquan Ma

Dissertations

Facet engineering of nanomaterials, especially metals and metal oxides has become an important strategy for tuning catalytic properties and functions from heterogeneous catalysis to electrochemical catalysis, photocatalysis, biomedicine, fuel cells, and gas sensors. The catalytic properties are highly related to the surface electronic structures, surface electron transport characteristics, and active center structures of catalysts, which can be tailored by surface facet control. The aim of this doctoral dissertation research is to study the facet-dependent properties of metal or metal oxide nanoparticles using multiple advanced characterization techniques. Specifically, the novel atomic force microscope-scanning electrochemical microscope (AFM-SECM) and density functional theory (DFT) …


Bioremediation Of Petroleum Hydrocarbons In Coastal Sediments, Charbel Abou Khalil Dec 2022

Bioremediation Of Petroleum Hydrocarbons In Coastal Sediments, Charbel Abou Khalil

Dissertations

The biodegradation of dispersed crude oil in the ocean is relatively rapid (a half-life of a few weeks). However, it is often much slower on shorelines, usually attributed to low moisture content, nutrient limitation, and higher oil concentrations in beaches than in dispersed plumes. Another factor may be the increased salinity of the upper intertidal and supratidal zones since these parts of the beach are potentially subject to prolonged evaporation and only intermittent inundation. Therefore, two laboratory experiments are conducted to investigate whether such an increase in porewater salinity results in additional inhibitory effects on oil biodegradation in seashores.

In …


2022 Scholarly Productivity Report, Missouri University Of Science And Technology Dec 2022

2022 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.


Analysis Of Possible Causes Of Industrial Injuries And Accidents At Coal Industry Enterprises, F U. Otabekov, M Z. Naimova Dec 2022

Analysis Of Possible Causes Of Industrial Injuries And Accidents At Coal Industry Enterprises, F U. Otabekov, M Z. Naimova

Technical science and innovation

In this article, the issues that a person may face unfortunate events due to a certain reason due to the influence of various dangerous and harmful factors in the course of his life activities are resolved. Depending on the type and degree of exposure or the cause of the accident, the type and degree of injury may also vary. In most cases, injuries and damages occur suddenly and can lead to unexpected and unexpected consequences. Let's imagine that an unfortunate event happened by chance. In this situation, many people lose their senses, start to panic, hurry, become overly nervous or …


Analysis Of Methods Of Construction And Application Of Modern Anti-Radar Missiles, A S. Solonar, P A. Khmarski, B M. Mukhammedov, G Sh Tuganov Dec 2022

Analysis Of Methods Of Construction And Application Of Modern Anti-Radar Missiles, A S. Solonar, P A. Khmarski, B M. Mukhammedov, G Sh Tuganov

Technical science and innovation

The analysis of methods of construction and application of modern anti-radar missiles (ARM) is carried out. The analysis allowed us to identify the most distinctive features of ARM such as: high flight speed (600-1200 m/s), limited launch range, different flight paths and it is oriented towards the attacked radar, small effective distribution surface (ESR), due to a sharp increase in the weight and size characteristics of the homing head of the homing head outside the frequency range (from 0.5 to 40 GHz), radio electronic means of the ARM are not created, the large range and high speed of tuning the …


Effect Of Hot Weather Concreting On The Mechanical And Durability Properties Of Concrete-A Review, Rawan Ramadan, Hassan Ghanem, Jamal Khatib, Adel Elkordi Dec 2022

Effect Of Hot Weather Concreting On The Mechanical And Durability Properties Of Concrete-A Review, Rawan Ramadan, Hassan Ghanem, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

Nowadays, hot weather is an essential motivator that leads concrete to lose its special characteristics. The high loss of moisture by evaporation and rapid hardening encourage the cracking potential and placement operations. The fresh mixed and hardened concrete tend to be damaged due to several conditions such as: high concrete temperature, High ambient temperature, low relative humidity, and high wind speed. These circumstances accelerate the rate of moisture loss and cement hydration. This article briefly reviews hot weather concreting problems precautions, and curing methods and also discusses the role of incorporation SCMs in reducing the temperature of concrete and enhancing …


Assessing The Influence Of Overweight Axles On Rutting Lives In Flexible Pavements Using Parametric Survival Analysis, Ali Hatoum, Jamal Khatib, Firas Barraj, Adel Elkordi Dec 2022

Assessing The Influence Of Overweight Axles On Rutting Lives In Flexible Pavements Using Parametric Survival Analysis, Ali Hatoum, Jamal Khatib, Firas Barraj, Adel Elkordi

BAU Journal - Science and Technology

The existence of rutting or permanent deformation on flexible pavement layers has always been a concern that negatively affects the performance of roads by reducing the lifespan of pavement structure and by posing a safety risk for vehicles over the road. Traffic overloading is one of the primary factors that accelerates the deterioration of flexible pavement. This study aims to determine the time to failure of the flexible pavement structures associated with rutting, to indicate the most significant factors affecting rutting, and to assess the influence of overweight axles on pavement rutting life using parametric survival analysis. The data used …


Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo Dec 2022

Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo

Makara Journal of Technology

The development of the crossing transportation industry is currently increasing in the island areas. The use of Ro-Ro type ferry boats is extremely efficient in moving people, goods, and vehicles. The current research focuses on the damage stability of the 500 DWT Ro-Ro ferry, which aims to meet the needs of the Ro-Ro ferry in the archipelago area. The previously existing initial design of a barge hull with a main size Lpp = 40.15 m, B = 12 m, H = 3.2 m, and T = 2.15 m was used to analyze the damage stability condition further. First, the drawings …


Fire-Resistance Testing Procedures For Construction Elements—A Review, Shashikant Chaturvedi, Ajitanshu Vedrtnam, Maged A. Youssef, Martin T. Palou, Gonzalo Barluenga, Kishor Kalauni Dec 2022

Fire-Resistance Testing Procedures For Construction Elements—A Review, Shashikant Chaturvedi, Ajitanshu Vedrtnam, Maged A. Youssef, Martin T. Palou, Gonzalo Barluenga, Kishor Kalauni

Civil and Environmental Engineering Publications

Fire accidents are a significant risk to human life and civil infrastructure. As a countermeasure, the regulatory bodies of different countries have established standards for evaluating the performance of construction elements during fire exposure. ISO 834 is the globally accepted fire-resistance testing standard. Other standards include ASTM E119, BS 476, IS 3809, JIS A 1304, AS 1503, EN 1363, and GB/T 9978, which are utilized by the US, Britain, India, Japan, Australia, Europe, and China, respectively. This article presents a summary and comparison of the fire-resistance testing standards. In reality, standard tests for isolated structural members may not efficiently portray …


Using Naming Conventions To Facilitate Data Transfer Between Asset Management Systems And Building Information Models, John D. Foster Dec 2022

Using Naming Conventions To Facilitate Data Transfer Between Asset Management Systems And Building Information Models, John D. Foster

Theses and Dissertations

An improvement to the workflow developed by Loeh et al. (2021) is proposed using a Revit template with BUILDER SMS naming conventions when creating the Sustainable Facility Management-enhanced BIM Model. The method presented by Loeh et al. (2021) is modified by integrating BUILDER SMS parameters and naming conventions into the BIM model during, as opposed to after, the creation of the model. Four building models created in 2020-21, four from 2021-22, and one building from 2019 were used in this study. Two groups of students were used to evaluate the effect of the building-specific BIM templates. Evaluating the 2020 and …


Design, Concept, And Visualization Of Urban Multi-Level Growing Table Systems In Hyper Urban Areas, Aaryan Manoj Nair, Shaheed Mohammed, Omar Rahama Dec 2022

Design, Concept, And Visualization Of Urban Multi-Level Growing Table Systems In Hyper Urban Areas, Aaryan Manoj Nair, Shaheed Mohammed, Omar Rahama

Publications and Research

As of a 2019 study conducted by the National Urban Gardening Program (National Urban Gardening Program), urban farming accounts for approximately 19% of the total national farming output and is expected to triple to almost 45% by 2025. There is intensive research being conducted on aspects of reduced recidivism, communal health benefits, natural carbon capture systems, improved urban ecology and the necessity for reducing the carbon footprint of food, (informally dubbed “food miles”) there is little substantive research on optimisation, and maximation of crop productivity in hyper-urban areas.

The purpose of this report is to understand the functionalities of urban …


Leveraging Crowdsourced Navigation Data In Roadway Pluvial Flash Flood Prediction, Arefeh Safaei-Moghadam Dec 2022

Leveraging Crowdsourced Navigation Data In Roadway Pluvial Flash Flood Prediction, Arefeh Safaei-Moghadam

Civil and Environmental Engineering Theses and Dissertations

This dissertation develops and tests a new data-driven framework for short-term roadway pluvial flash flood (PFF) risk estimation at the scale of road segments using crowdsourced navigation data and a simplified physics-based PFF model. Pluvial flash flooding (PFF) is defined as localized floods caused by an overwhelmed natural or engineered drainage system. This study develops a data curation and computational framework for data collection, preprocessing, and modeling to estimate the risk of PFF at road-segment scales. A hybrid approach is also developed that couples a statistical model and a simplified physics-based simulation model in a machine learning (ML) model to …


Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi Dec 2022

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …


Reduction Of Embodied Carbon In Buildings Through Use Of Low Carbon Strategies And Standardization And Enforcement Of Life Cycle Assessment, Bhargavi Sai Sudhakar Dec 2022

Reduction Of Embodied Carbon In Buildings Through Use Of Low Carbon Strategies And Standardization And Enforcement Of Life Cycle Assessment, Bhargavi Sai Sudhakar

Master's Projects and Capstones

The building and construction industry is energy intensive and as of 2021, this industry is responsible for 37% of the total global greenhouse gas emissions. In previous studies of conventional buildings, the operational energy of a building contributed to 80% and the embodied energy contributed to 20% of the total life cycle energy. With increase in policies and standards that focus on reducing the operational energy, low energy and certified green buildings have emerged where the operational energy has considerably reduced. The relative and absolute share of embodied energy in these energy efficient buildings have increased due to excessive use …


Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer Dec 2022

Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer

Electronic Theses and Dissertations

Tidal rivers are landward portions of estuarine systems constituting the union between coastal, tidally controlled settings and rivers, where fluvial processes dominate. In these reaches, river discharge (mean flow) and tides are the two most important mechanisms in controlling geophysical flows. The processes governing water levels and current amplitudes in tidal rivers are highly nonlinear and modulated by external forcings- thus requiring sophisticated techniques for accurate prediction and forecasting. Physical oceanographers and estuarine physicists tend to limit their study area to the maximum extent of the horizontal tide (salinity intrusion), not the most landward point influenced by tidal water levels. …


Estimating Vehicle Infrastructure: Downtown Albuquerque, New Mexico, Zachery Phillip Baiamonte Dec 2022

Estimating Vehicle Infrastructure: Downtown Albuquerque, New Mexico, Zachery Phillip Baiamonte

Architecture and Planning ETDs

Cities have little knowledge about their parking infrastructure despite clear evidence that abundant parking has environmental, economic, and transportation consequences. The objective of this thesis is to illustrate the need to accurately estimate the area dedicated to vehicle infrastructure (parking lots and streets) within urban areas. I focused on a method that estimated the vehicle infrastructure area within the Downtown Core of Albuquerque, New Mexico, by cross-referencing geospatial cadastral data with minimum parking requirements. Three parking space types were identified: 1) parking in structures; 2) surface parking (parking lots and residential driveways); and 3) on-street parking. To illustrate the need …


Modeling The Impact Of The Covid-19 Pandemic On Speeding At Rural Roadway Facilities In Maine Using Short-Term Speed And Traffic Count Data., Amirhossein Shahlaeegilan Dec 2022

Modeling The Impact Of The Covid-19 Pandemic On Speeding At Rural Roadway Facilities In Maine Using Short-Term Speed And Traffic Count Data., Amirhossein Shahlaeegilan

Electronic Theses and Dissertations

The COVID-19 pandemic caused a significant change in traffic operations and safety. For instance, various U.S. states reported an increase in the rate of fatal and severe injury crashes over this duration. In April and May 2020, the comprehensive stay-at-home orders were issued across the country, including in Maine. These orders resulted in drastic reductions in traffic volume,switching working policies of noticeable number of corporations and educational administrations like universities to the remote working, closure of many organizations during the lockdown period, and people avoidance to public places to suppress the possible exposure to the virus were among the most …


Wind-Borne Debris Resistance Of Façades: Identification Of Alternative Impact Test Requirements, Angela Mejorin Dec 2022

Wind-Borne Debris Resistance Of Façades: Identification Of Alternative Impact Test Requirements, Angela Mejorin

Electronic Thesis and Dissertation Repository

Climate change effects are causing a steady increase of previous records both in terms of monetary losses and in fatality occurrence due to severe storms. The frequency and intensity of disaster events are increasing worldwide and areas that were excluded from these extreme weather scenarios in the past, are now looking for solutions to increase the urban resilience. Among others, extreme winds are endangering the built environment, often leading to the breakage of the primary barrier to protect people and property: the building envelope. On May 22nd, 2011, the Joplin tornado killed 161 people, and 14 of those were receiving …


Energy Efficiency Retrofit And Decarbonization Of Old And Historic Buildings In California, Daria Nikolaeva Dec 2022

Energy Efficiency Retrofit And Decarbonization Of Old And Historic Buildings In California, Daria Nikolaeva

Master's Projects and Capstones

Buildings are responsible for almost 40% of total global greenhouse gas emissions and the retrofitting of existing buildings is an essential part of solving the problem. About 75% of buildings in Californian were constructed before the first energy-efficiency building code was adopted in 1978. Old buildings are inefficient, responsible for large carbon footprints and must be retrofitted to stay on track with the state's climate targets. However, current policies do not require substantial changes and tend to favor historic preservation over energy efficiency, missing improvement opportunities. Recognizing the significance of carbon intensity, the 2019 California Energy Efficiency Action Plan shifted …


Polyelectrolyte Functionalized Forward Osmosis For Water Reclamation From Synthetic Spacecraft Wastewater, Alina Ripp Dec 2022

Polyelectrolyte Functionalized Forward Osmosis For Water Reclamation From Synthetic Spacecraft Wastewater, Alina Ripp

Electronic Theses and Dissertations, 2020-2023

This study investigated the application of a polyelectrolyte (PE)-assisted metallic iron nanoparticle-integrated forward osmosis (FO) membrane to treat synthetic spacecraft wastewater comprising urea, ammonium carbonate, and linear alkylbenzene sulfonate (LAS). The draw solution (MgSO4) diluted via the FO operation was further treated using a nanofiltration (NF) membrane aimed at producing potable quality water by the FO-NF hybrid process. A cellulose triacetate FO membrane was functionalized by layer-by-layer deposition of polyallylamine hydrochloride (PAH) and polyacrylic acid (PAA) followed by incorporating zero valent iron nanoparticles (ZVINP) within the "bilayers". It required 14 bilayers to ensure a uniform coating as demonstrated via scanning …


Seismic Site Characterization And Response In Metropolitan Vancouver, Jamal Assaf Dec 2022

Seismic Site Characterization And Response In Metropolitan Vancouver, Jamal Assaf

Electronic Thesis and Dissertation Repository

Metropolitan (Metro) Vancouver is the largest city in British Columbia and has the highest earthquake risk in Canada due to vulnerability of persons and infrastructure located near the Cascadia subduction zone. The effects of local geology on seismic waves (site effects) play a major role in determining surface shaking levels and seismic hazard. Site effects are typically accounted for in ground motion prediction by inclusion of important seismic site characteristics. This thesis first evaluates the seismic site characteristics across Metro Vancouver then facilitates the development of a region-specific site amplification model.

To evaluate site characteristics in Metro Vancouver, a comprehensive …


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 …


A Framework For Multi-Dimensional Assessment Of The Impacts Of Overweight Vehicle Operations And A Corridor-Level Case Study, Maria Alicia Chung Li Dec 2022

A Framework For Multi-Dimensional Assessment Of The Impacts Of Overweight Vehicle Operations And A Corridor-Level Case Study, Maria Alicia Chung Li

Lyles School of Civil Engineering Graduate Student Reports

Ground freight transportation is essential for the economy of any region. The efficient movement of goods from one location to another connects businesses with suppliers and customers, that enhances commerce and ultimately boosts the economy. The high volume of freight that has been transported on the nation’s highway network has allowed the trucking industry to provide enormous socio-economic benefits. Unfortunately, these benefits come with some costs associated with the operation of overweight (OW) trucks, such as accelerated deterioration of highway pavement and bridge assets, and passenger and freight traffic safety degradation. Thus, to manage safety risk, traffic mobility, and infrastructure …


Nucleation-Accumulation Mode Trade-Off In Non-Volatile Particle Emissions From A Small Non-Road Small Diesel Engine, Indranil Brahma, Odinmma John-Paul Ofili Dec 2022

Nucleation-Accumulation Mode Trade-Off In Non-Volatile Particle Emissions From A Small Non-Road Small Diesel Engine, Indranil Brahma, Odinmma John-Paul Ofili

Faculty Journal Articles

Small (< 8 kW) non-road engines are a significant source of pollutants such as particle number (PN) emissions. Many small non-road engines do not have diesel particulate filters (DPFs). They are so designed that air–fuel ratio (AFR) can be adjusted to control visible diesel smoke and particulate matter (PM) resulting from larger accumulation mode particles. However, the effect of AFR variation on smaller nucleation mode nanoparticle emissions is not well understood. Several studies on larger engines have reported a trade-off between smaller and larger particles. In this study, AFR was independently varied over the entire engine map of a naturally aspirated (NA) non-road small diesel engine using forced induction (FI) of externally compressed air. AFR’s ranged from 57 to 239 compared to the design range of 23–92 for the engine, including unusually high AFR’s at full-load operation, not previously reported for conventional combustion. As expected, larger accumulation mode particles were lowered (up to 15 times) for FI operation. However, the smaller nucleation mode nanoparticles increased up to 15 times. Accumulation mode particles stopped decreasing above an AFR threshold while nucleation particles continuously increased. In-cylinder combustion analysis showed a slightly smaller ignition delay and higher burn rate for FI cases relative to NA operation. Much higher peak cylinder pressures were accompanied by much lower combustion and exhaust gas temperatures (EGT), due to higher in-cylinder mass during FI operation. Peak nucleation mode emissions were shown to be negatively correlated to EGT for all the data, collapsing on a single curve. This is consistent with some other studies reporting increased nucleation mode emissions (and higher accumulation mode particles) with decreased load, lower speed, lower EGR, advanced combustion phasing, and higher injection pressure, all of which reduce EGT. The nucleation-accumulation trade-off has been explained by the ‘adsorption hypothesis’ by some investigators. In the current work, an alternative/supplemental argument has been made for the possibility that lower cylinder temperatures during the late-burning phase (correlated to lower EGT) phase hampers oxidation of nucleation mode particles and increases nucleation mode emissions.


Exploring The Use Of Piox System For Treatment Of Endocrine Disrupting Compounds, Alexander Pearson Dec 2022

Exploring The Use Of Piox System For Treatment Of Endocrine Disrupting Compounds, Alexander Pearson

Civil Engineering Theses

In this thesis, the Photon Initiated Oxidation (PIOx) system was investigated for its possible use in the treatment of Endocrine Disrupting Compounds (EDCs). It was theorized that the unique design of the system, namely the multiple wavelengths of UV light and the micronfoam would improve removal rates of the test contaminant when compared to other systems. 17β-estradiol was chosen as the test contaminant due to the compounds known sensitivity to ozone exposure. Two methods of testing were used, the first to test an idealized homogenous concentration (method one) and the second to mimic the sudden influx of contaminant that would …


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 …


Resiliency Of Levee-Protected Power Networks To Flooding In A Changing Climate Integrating Environmental Justice, Seyed Saeed Miraee-Ashtiani Dec 2022

Resiliency Of Levee-Protected Power Networks To Flooding In A Changing Climate Integrating Environmental Justice, Seyed Saeed Miraee-Ashtiani

Theses and Dissertations

Electric power system (EPS) is an integral part of infrastructure systems. Ensuring its resiliency to extreme weather events and natural hazards is crucial to protect the safety, economy and public health. Recorded and projected data show an increase in the frequency and severity of extreme weather events and natural hazards attributed to a changing climate. It is critical to ensure the integrity of the aging infrastructure systems and to promote environmental justice by shrinking the energy-equity gap to lower power outages in disadvantaged communities.

An important aspect is the resiliency interdependency of EPS to other critical infrastructure systems, an aspect …


Inequity Of Access Across America: A Spatial, Temporal, And Modal Disparity Analysis, Sanju Maharjan Dec 2022

Inequity Of Access Across America: A Spatial, Temporal, And Modal Disparity Analysis, Sanju Maharjan

Theses and Dissertations

The overarching goal of this dissertation is to examine the spatial, temporal, and modal disparity of access across America. This is achieved by posing three research objectives. The first objective determines the spatial and temporal disparity of transit and automobile access gap, its impact on transit use, and its socioeconomic and built environment correlates. The second objective examines the spatial and temporal disparity of slightly and extremely risky bike infrastructure and measures the social inequity of access to bike infrastructure. The third objective indicates spatial transit access mismatch between high- and low-wage employment across metropolitans. Three findings are discerned. First, …


Hydraulic Redistribution Under Saline Conditions, Josh Gottlieb Dec 2022

Hydraulic Redistribution Under Saline Conditions, Josh Gottlieb

Civil and Environmental Engineering Undergraduate Honors Theses

Water scarcity and soil salinity are dual stressors for plants in arid, salt-affected ecosystems. Hydraulic redistribution, a hydraulic adaptation which moves water through plant roots into dry or saline soil regions along potential gradients, aids plant survival in stressful environments. Recent theory regarding hydraulic redistribution proposes limitations on the process within saline soils. This study applies a minimalist resistor-capacitor model of the soil-plant-atmosphere system to the experimental conditions of a 2010 study investigating hydraulic redistribution in a salt affected area. The effectiveness of the model is evaluated, and a sensitivity analysis is conducted to identify key dynamics affecting the moisture …


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. …