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2023

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Articles 601 - 630 of 1746

Full-Text Articles in Civil and Environmental Engineering

Traffic Conflict Analysis Of Multila Neexpressway Based On Simulation, Ceng Yuekai, Zhou Tao, Chen Yazhen Jul 2023

Traffic Conflict Analysis Of Multila Neexpressway Based On Simulation, Ceng Yuekai, Zhou Tao, Chen Yazhen

Journal of China & Foreign Highway

In order to prevent traffic accidents on multi-lane expressways, the VISSIM traffic simulation model was established based on three types of multi-lane traffic conflicts: mixed passenger and cargo type, separated passenger and cargo type, and separated main and auxiliary type. SSAM software was used to obtain traffic conflict data, and the form, quantity, and location of the conflicts were analyzed. The results show that traffic conflicts are the most under the mixed passenger and cargo type, which are mainly distributed in the upper 100 m range of the innermost lane, outermost lane, and deceleration lane. The traffic conflicts under the …


Risk Analysis Of Highway Nighttime Maintenance Operation Based On Sem, Fan Jinhua, Zou Leping, Qi Shaoren, Tian Zhen Jul 2023

Risk Analysis Of Highway Nighttime Maintenance Operation Based On Sem, Fan Jinhua, Zou Leping, Qi Shaoren, Tian Zhen

Journal of China & Foreign Highway

In order to analyze the factors affecting the risk of nighttime expressway maintenance operation and quantitatively assess the degree of influence of various factors on the risk of nighttime maintenance operation, this paper extracted five first-level indicators and 36 second-level indicators that affect the risk of operation through literature review, accident data, and questionnaire survey and built an evaluation system. The first-order and second-order confirmatory factor analysis models were constructed by using a structural equation model (SEM) based on 343 questionnaires of the nighttime maintenance operation risks. The results show that the driver factor has the greatest effect on the …


Study On Effectiveness Evaluation Method Of Expressway Drainage System In Rainy Area, Luo Datian, Li Jiayi, Zou Jingrong Jul 2023

Study On Effectiveness Evaluation Method Of Expressway Drainage System In Rainy Area, Luo Datian, Li Jiayi, Zou Jingrong

Journal of China & Foreign Highway

In order to comprehensively evaluate the effectiveness of expressway drainage systems in rainy areas and comprehensively analyze the factors affecting the effectiveness of drainage systems, this paper took the perfection of drainage system, stability of drainage facilities, and road traffic safety as the first-level evaluation index and six kinds of influencing factors such as the degree of integrity as the second-level index, and it put forward the evaluation criteria of the effectiveness of expressway drainage system in rainy areas. The fuzzy comprehensive evaluation method was used to determine the membership degree of expert scoring through the trapezoid membership function, and …


Research On Crack And Permeability Characteristics Of Cement ⁃Modified Expansive Soil Under Dry ⁃Wet Cycles, Bao Guiyong, Xu Yangshaojun, Jiang Zhijie, Rong Hongliu, Wang Jinlong Jul 2023

Research On Crack And Permeability Characteristics Of Cement ⁃Modified Expansive Soil Under Dry ⁃Wet Cycles, Bao Guiyong, Xu Yangshaojun, Jiang Zhijie, Rong Hongliu, Wang Jinlong

Journal of China & Foreign Highway

In order to study the engineering permeability characteristics of cement-modified expansive soil under dry and wet cycles, the mix ratio of cement-modified expansive soil was designed, and the orthogonal design test method was adopted. Image analysis software PACS, unconfined compressive strength test, and laboratory permeability test were used to study the crack development, strength attenuation characteristics, and permeability changes of cement-modified expansive soil under dry and wet cycle conditions. The results show that soil permeability and strength are greatly affected by the number of dry and wet cycles. Under the condition of dry and wet cycles, the moisture content of …


Digital Challenges And Opportunities Of Addressing On-Site Productivity And Safety On Construction Job Sites: An International Perspective, Ahmed Hassan, Ankur Mitra, Mark Mulville, Alan Hore Jul 2023

Digital Challenges And Opportunities Of Addressing On-Site Productivity And Safety On Construction Job Sites: An International Perspective, Ahmed Hassan, Ankur Mitra, Mark Mulville, Alan Hore

Conference papers

The slow pace of digital transformation in construction remains an impediment to the industry’s evolution. Despite rapid developments in digital technologies, the vast bulk of data generated on construction job sites remains underutilised due to the limited use of real-time data capture. The diffusion of digital solutions in construction depends on successfully capturing critical real-time data that can inform and contribute to more productive work patterns and safer job sites. Nevertheless, the construction industry’s fragmented nature has segregated the digital solutions offered by technology providers from the volatile challenges facing on-site construction practitioners.

This paper will present the early development …


Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan Jul 2023

Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan

LSU Master's Theses

Mangrove forests can be found along the world’s intertidal tropical and sub-tropical coastlines. These forested wetlands provide many ecosystem services, including supporting coastal food chains, trapping sediment, and shoreline stabilization. Mangroves are also known for flood damage mitigation by dissipating waves and surge during flooding events. Thus, coastal communities declare a vested interest in the performance of the forest to mitigate flood damage. Physical models using artificial mangrove structures have shown that red mangrove-dominated fringe forests can protect built infrastructure by reducing wave height due to increased drag. One way to estimate the contribution of red mangrove (Rhizophora mangle) prop …


Size Effects In Additively Manufactured Inconel-718 Thin Elements And Cellular Structures, Reem Abdelkarim Abo Znemah Jul 2023

Size Effects In Additively Manufactured Inconel-718 Thin Elements And Cellular Structures, Reem Abdelkarim Abo Znemah

LSU Doctoral Dissertations

A current focus in the additive manufacturing (AM) research community is the production of complex shaped metallic parts and cellular structures. Many researchers went on analyzing and simulating these structures without considering the effect of the element thickness and heterogeneous printing parameters on the resulting material behavior. To advance the application of laser powder bed fusion (LPBF), an AM process, in producing Inconel718 (IN718) complex shaped parts and cellular structures, this study aimed to investigate the effect of thin-walled elements thickness on the mechanical characteristics of both the individual elements and overall cellular structure. A multiscale experimental evaluation of the …


Exploration Of Efficient Dewatering Methods In Stimulus-Responsive Hydrogels And Their Potential For Desalination, Weiliang Sun Jul 2023

Exploration Of Efficient Dewatering Methods In Stimulus-Responsive Hydrogels And Their Potential For Desalination, Weiliang Sun

LSU Doctoral Dissertations

Addressing global freshwater scarcity is a pressing challenge, and desalination has emerged as a viable solution to generate high-quality water without compromising natural freshwater ecosystems. In comparison to conventional desalination methods such as thermal distillation and membrane-based processes, hydrogels offer distinct advantages including strong water absorption, water retention, well-defined pore structures, customizable functional groups, and responsive properties to external stimuli. These unique characteristics position hydrogels as promising candidates for water treatment applications. Hydrogel-based desalination involves the utilization of hydrogels to absorb water from saltwater, and then discharge low-concentration solutions to obtain reclaimed water. The fundamental principle underlying the desalination ability …


Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat Jul 2023

Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Internal curing (IC) and other shrinkage mitigating materials are employed to reduce shrinkage and risk of cracking. This study investigates the efficiency of individual versus combined use of IC and shrinkage mitigating materials on key characteristics of fiber-reinforced mortar (FRM). The investigated mixtures include a 25% pre-saturated lightweight sand (LWS) that is added individually and combined with 10% CaO-based expansive agent (EA) and 2% shrinkage reducing admixture (SRA). This elucidates the synergistic effect of high content IC and EA/SRA on macro- and micro-mechanical characteristics of FRM, especially at the interface of the matrix with fibers. Mechanical properties, microstructural characteristics, and …


Triverus Infiltration And Cleaning Report 2023, Unh Stormwater Center Jul 2023

Triverus Infiltration And Cleaning Report 2023, Unh Stormwater Center

UNH Stormwater Center

No abstract provided.


Probabilistic Modeling Of North Atlantic Ocean Hurricane Spawn Considering Climate Change, Susmita Bhowmik, Weichiang Pang, Michael Stoner Jul 2023

Probabilistic Modeling Of North Atlantic Ocean Hurricane Spawn Considering Climate Change, Susmita Bhowmik, Weichiang Pang, Michael Stoner

Publications

Hurricanes are a significant natural hazard, which cause significant damage and financial losses in the coastal areas of the United States almost every year. For example, the devastating nature of North Atlantic Ocean (NAO) storms can easily be understood from the 2005 Hurricane Katrina, which was the most damaging NAO storm in modern history, causing more than 1,800 deaths and a financial loss of at least 161.3 billion USD. It has been found that the formations of hurricanes depend heavily on climate conditions, which implies a direct relationship between the changes in climate extremes and the occurrences of hurricanes or …


Development Of A Covid-19 Vulnerability Index (Cvi) For The Counties And Residents Of New Jersey, Usa., Remo Disalvatore, Sarah K Bauer, Jeong Eun Ahn, Kauser Jahan Jul 2023

Development Of A Covid-19 Vulnerability Index (Cvi) For The Counties And Residents Of New Jersey, Usa., Remo Disalvatore, Sarah K Bauer, Jeong Eun Ahn, Kauser Jahan

Henry M. Rowan College of Engineering Departmental Research

The coronavirus disease 2019, or COVID-19, has impacted countless aspects of everyday life since it was declared a global pandemic by the World Health Organization in March of 2020. From societal to economic impacts, COVID-19 and its variants will leave a lasting impact on our society and the world. During the height of the pandemic, it became increasingly evident that indices, such as the Center for Disease Control's (CDC) Social Vulnerability Index (SVI), were instrumental in predicting vulnerabilities within a community. The CDC's SVI provides important estimates on which communities will be more susceptible to 'hazard events' by compiling a …


Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller Jul 2023

Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

Federal requirements have made it mandatory that safe mailbox support systems be designed to yield or breakaway whenimpacted by a vehicle. The Nebraska Department of Transportation (NDOT) has previously used a non-proprietary, U-channel post mailbox support that was evaluated at the Midwest Roadside Safety Facility (MwRSF) in the 1980's. NDOT desires that the mailbox support be updated to meet MASH 2016 TL-3 safety performance criteria and be redesigned to use perforated square steel tubing (PSST) for the mailbox support post.

The objective of this research project is to develop a non-proprietary mailbox support using PSST support posts that is MASH …


Characterizing Wind-Wave Flow Physics And Loading Effects On Power Transmission Systems And Offshore Wind Turbines, Tianqi Ma Jul 2023

Characterizing Wind-Wave Flow Physics And Loading Effects On Power Transmission Systems And Offshore Wind Turbines, Tianqi Ma

LSU Doctoral Dissertations

Recent extreme hurricanes caused extensive damage to critical civil infrastructure. Accurate modeling of the extreme complex wind fields and coupled wind-wave fields is essential to quantify the single wind or combined wind-wave loading effects on the structures. This research aims to characterize wind and wind-wave flow physics to quantify the loading effect on power transmission systems and offshore wind turbines.

First, a microscale (∼km) high-fidelity high-resolution computational model is developed to simulate hurricane wind fields with detailed physics. The generated wind field is applied to analyze the structural response of a power transmission system. The proposed hurricane boundary layer (HBL) …


Public Sector Bim Adoption: Development And Evaluation Of Government Policy Interventions: A Systematic Literature Review, Shiyao Kuang, Alan Hore, Ahmed Hassan, Barry Mcauley, Roger West Jul 2023

Public Sector Bim Adoption: Development And Evaluation Of Government Policy Interventions: A Systematic Literature Review, Shiyao Kuang, Alan Hore, Ahmed Hassan, Barry Mcauley, Roger West

Conference Papers

Rapid technological advancements in the Architecture, Engineering and Construction (AEC) sector have provided a significant opportunity for improving the industry's efficiency, performance and sustainability. Building Information Modelling (BIM) is an innovative approach to information management in construction that provides a structured methodology for storing and analysing building information exchanged between project stakeholders. However, successful interventions and supports introduced by the public sector in accelerating BIM adoption can be seen through BIM mandates, promotion of information management ISO standards, guidance, funding and procurement integration. In this study, a systematic literature review is adopted to identify BIM policy interventions. The study aims …


Increasing The Impact Of Utah State University's Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio Jul 2023

Increasing The Impact Of Utah State University's Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio

Reports

Study Goal – Increase the volume of water saved by the Utah State University (USU) Extension landscape Water Check program because outdoor water use is the largest component of residential use with the largest opportunity to reduce use. We used 5-second water use data collected with Flume Smart Home Water Monitoring devices (Figure 1) at residential homes before and after a Water Check (Box 1; Figure 2) to answer four questions:

  1. How much water did households save?
  2. Which Water Check recommendations did participants implement?
  3. Why did participants implement some recommendations and not others?
  4. How to further reduce landscape water use?


Increasing The Impact Of Utah State University’S Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio Jul 2023

Increasing The Impact Of Utah State University’S Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio

Reports

Study Goal – Increase the volume of water saved by the Utah State University (USU) Extension landscape Water Check program because outdoor water use is the largest component of residential use with the largest opportunity to reduce use. We used 5-second water use data collected with Flume Smart Home Water Monitoring devices (Figure 1) at residential homes before and after a Water Check (Box 1; Figure 2) to answer four questions:

  1. How much water did households save?

  2. Which Water Check recommendations did participants implement?

  3. Why did participants implement some recommendations and not others?

  4. How to further reduce landscape water use?


Assessing The Impact Of Spatial Resolution Of Uas-Based Remote Sensing And Spectral Resolution Of Proximal Sensing On Crop Nitrogen Retrieval Accuracy, Kianoosh Hassani, Hamed Gholizadeh, Saleh Taghvaeian, Victoria Natalie, Jonathan Carpenter, Jamey Jacob Jul 2023

Assessing The Impact Of Spatial Resolution Of Uas-Based Remote Sensing And Spectral Resolution Of Proximal Sensing On Crop Nitrogen Retrieval Accuracy, Kianoosh Hassani, Hamed Gholizadeh, Saleh Taghvaeian, Victoria Natalie, Jonathan Carpenter, Jamey Jacob

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Foliar nitrogen (N) plays a central role in photosynthetic machinery of plants, regulating their growth rates. However, field-based methods for monitoring plant N concentration are costly and limited in their ability to cover large spatial extents. In this study, we had two objectives: (1) assess the capability of unoccupied aerial system (UAS) and non-imaging spectroscopic data in estimating sorghum and corn N concentration and (2) determine the impact of spatial and spectral resolution of reflectance data on estimating sorghum and corn N concentration. We used a UAS and an ASD spectroradiometer to collect canopy- and leaf-level spectral data from sorghum …


Residential Building Flood Risk Assessment And The Benefits Of Home Elevation, Ayat Al Assi Jul 2023

Residential Building Flood Risk Assessment And The Benefits Of Home Elevation, Ayat Al Assi

LSU Doctoral Dissertations

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars is needed to provide valuable information for stakeholder decision-making inside and outside the special flood hazard area (SFHA, which corresponds to the 100-year floodplain). To further inform flood mitigation strategies, quantifying flood risk reduction with home elevation above an initial first-floor height (FFH0) and the cost effectiveness of federal mitigation assistance for elevation are important steps to enhance awareness of the effect of elevation in reducing flood risk. …


Adsorptive–Photocatalytic Performance For Antibiotic And Personal Care Product Using Cu0.5Mn0.5Fe2O4, Chanat Chokejaroenrat, Chainarong Sakulthaew, Athaphon Angkaew, Apiladda Pattanateeradetch, Wuttinun Raksajit, Kanokwan Teingtham, Piyaporn Phansak, Pawee Klongvessa, Daniel D. Snow, Clifford E. Harris, Steven Comfort Jul 2023

Adsorptive–Photocatalytic Performance For Antibiotic And Personal Care Product Using Cu0.5Mn0.5Fe2O4, Chanat Chokejaroenrat, Chainarong Sakulthaew, Athaphon Angkaew, Apiladda Pattanateeradetch, Wuttinun Raksajit, Kanokwan Teingtham, Piyaporn Phansak, Pawee Klongvessa, Daniel D. Snow, Clifford E. Harris, Steven Comfort

Nebraska Water Center: Faculty Publications

The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu0.5Mn0.5Fe2O4 nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu0.5Mn0.5Fe2O4 recrystallized, improving material crystallinity and purity for the adsorptive–photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction …


A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario Buchely, Ronald O'Malley, Haiming Wen Jul 2023

A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario Buchely, Ronald O'Malley, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Most of the face-centered cubic (FCC) multi-principal element alloys (MPEAs) developed thus far contain cobalt. for many applications, it is either required or beneficial to avoid cobalt, since cobalt has long-term activation issue (for nuclear applications), is expensive, and is considered a critical material. in addition, FCC structured solid-solution MPEAs tend to have relatively low strength. an FCC solid-solution Fe30Ni30Mn30Cr10 (at %) MPEA was fabricated via arc melting, followed by homogenization at 1100 °C for 12 h. the alloy was hot rolled at 1100 °C with a total reduction of up to 97 %. the microstructure was characterized, and mechanical …


Optimizing The Membrane-Assisted Recovery Of Solids (Mars) Technology For Nutrient Removal And Recovery From Concentrated Waste Streams, Ben Yamin Hoque Jul 2023

Optimizing The Membrane-Assisted Recovery Of Solids (Mars) Technology For Nutrient Removal And Recovery From Concentrated Waste Streams, Ben Yamin Hoque

USF Tampa Graduate Theses and Dissertations

The effective management of nutrients, such as nitrogen and phosphorus, in decentralizedwastewater treatment environments is a pressing challenge. These nutrients pose significant risks to the environment and public health when discharged into water bodies, while their recovery and reuse can help alleviate nutrient shortages in various industries, including agriculture. Conventional biological treatment methods used in centralized facilities are not suitable for decentralized systems due to operational complexities and space limitations. Chemical treatment mechanisms, such as adsorption, ion exchange, precipitation, and air-stripping, offer potential solutions but are accompanied by challenges like high costs and logistical issues. Therefore, finding a sustainable and …


Exploration Of Shared Passenger Urban Air Mobility – Integrated Network Design, Operation Scheduling And System Configuration, Zhiqiang Wu Jul 2023

Exploration Of Shared Passenger Urban Air Mobility – Integrated Network Design, Operation Scheduling And System Configuration, Zhiqiang Wu

USF Tampa Graduate Theses and Dissertations

Urban air mobility (UAM) is an emerging concept proposed in recent years that uses electric vertical take-off and landing vehicles (eVTOLs). UAM is expected to offer an alternative way of transporting passengers and goods in urban areas with significantly improved mobility by making use of low-altitude airspace. Considering the high capital investment of eVTOLs and relative high fee of using UAM passenger service, a viable UAM format is shared passenger service. Such a service is usually station-based, i.e., with vertiport located in popular sites where potential passengers can access. To understand the viability of such use cases, the vertiport owners …


Viscoelastic Properties Of Fresh Cement Paste: Measuring Procedures And Influencing Parameters, Ammar Yahia, Arnaud Perrot, Dimitri Feys, Kamal Khayat, Mohammed Sonebi, Shiho Kawashima, Wolfram Schmidt Jul 2023

Viscoelastic Properties Of Fresh Cement Paste: Measuring Procedures And Influencing Parameters, Ammar Yahia, Arnaud Perrot, Dimitri Feys, Kamal Khayat, Mohammed Sonebi, Shiho Kawashima, Wolfram Schmidt

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fresh cement pastes behave as viscoelastic materials below the flow onset. The measurements of viscoelastic properties of fresh cement paste provide valuable insight into the dispersion of solid particles as well as the hydration kinetics at early age and its influence on the structural evolution and solidification behavior at quasi-static conditions. Monitoring the development of viscoelastic properties of fresh cement paste using dynamic oscillatory shear measurements can also elucidate the working mechanisms of chemical admixtures. These properties are efficient indicators to guide mixture proportion design and are necessary to understand the rheology and stability of concrete. In this paper, the …


Exploring The Determinants Of Organic Matter Bioavailability Through Substrate-Explicit Thermodynamic Modeling, Firnaaz Ahamed, Yaqi You, Amy Burgin, James C. Stegen, Timothy D. Scheibe, Hyun-Seob Song Jul 2023

Exploring The Determinants Of Organic Matter Bioavailability Through Substrate-Explicit Thermodynamic Modeling, Firnaaz Ahamed, Yaqi You, Amy Burgin, James C. Stegen, Timothy D. Scheibe, Hyun-Seob Song

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Microbial decomposition of organic matter (OM) in river corridors is a major driver of nutrient and energy cycles in natural ecosystems. Recent advances in omics technologies enabled high-throughput generation of molecular data that could be used to inform biogeochemical models. With ultrahigh-resolution OM data becoming more readily available, in particular, the substrate-explicit thermodynamic modeling (SXTM) has emerged as a promising approach due to its ability to predict OM degradation and respiration rates from chemical formulae of compounds. This model implicitly assumes that all detected organic compounds are bioavailable, and that aerobic respiration is driven solely by thermodynamics. Despite promising demonstrations …


Experimental Study: The Effect Of Pore Shape, Geometrical Heterogeneity, And Flow Rate On The Repetitive Two-Phase Fluid Transport In Microfluidic Porous Media, Seunghee Kim, Jingtao Zhang, Sangjin Ryu Jul 2023

Experimental Study: The Effect Of Pore Shape, Geometrical Heterogeneity, And Flow Rate On The Repetitive Two-Phase Fluid Transport In Microfluidic Porous Media, Seunghee Kim, Jingtao Zhang, Sangjin Ryu

Department of Civil and Environmental Engineering: Faculty Publications

Geologic subsurface energy storage, such as porous-media compressed-air energy storage (PM-CAES) and underground hydrogen storage (UHS), involves the multi-phase fluid transport in structurally disordered or heterogeneous porous media (e.g., soils and rocks). Furthermore, such multi-phase fluid transport is likely to repeatedly occur due to successive fluid injections and extractions, thus, resulting in cyclic drainage–imbibition processes. To complement our preceding study, we conducted a follow-up study with microfluidic pore-network devices with a square solid shape (Type II) to further advance our understanding on the effect of the pore shape (aspect ratio, Type I: 5–6 > Type II: ~1), pore-space heterogeneity (coefficient of …


Uncovering The Spatio-Temporal Impact Of The Covid-19 Pandemic On Shared E-Scooter Usage: A Spatial Panel Model, Farzana Mehzabin Tuli, Arna Nishita Nithila, Suman Mitra Jul 2023

Uncovering The Spatio-Temporal Impact Of The Covid-19 Pandemic On Shared E-Scooter Usage: A Spatial Panel Model, Farzana Mehzabin Tuli, Arna Nishita Nithila, Suman Mitra

Civil Engineering Faculty Publications and Presentations

This study examines the spatio-temporal effects of the COVID-19 pandemic on shared e-scooter usage by leveraging two years (2019 and 2020) of daily shared micromobility data from Austin, Texas. We employed a series of random effects spatial-autoregressive model with a spatially autocorrelated error (SAC) to examine the differences and similarities in determinants of e-scooter usage during regular and pandemic periods and to identify factors contributing to the changes in e-scooter use during the Pandemic. Model results provided strong evidence of spatial autocorrelation in the e-scooter trip data and found a spatial negative spillover effect in the 2020 model. The key …


Improved Burned Area Mapping Using Monotemporal Landsat-9 Imagery And Convolutional Shift-Transformer, Seyd Teymoor Seydi, Mojtaba Sadegh Jul 2023

Improved Burned Area Mapping Using Monotemporal Landsat-9 Imagery And Convolutional Shift-Transformer, Seyd Teymoor Seydi, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Satellite imagery, specifically Landsat, have been widely used for mapping and monitoring wildfire burned areas. The new Landsat-9 satellite – with higher radiometric resolution compared to its predecessors, and improved temporal resolution when combined with Landsat-8 (∼8 days) – enables a wide range of applications, particularly burned area mapping (BAM). We propose a novel deep learning BAM model that leverages the strengths of the convolutional layers for deep feature generation from Landsat-9 imagery and shift-transformer block for burned area classification. The performance of the model is evaluated in five large fire case studies across the globe. BAM results are also …


Load Effects Of Truck Platooning On Existing Bridges In Oregon, Patricia Oleson Jul 2023

Load Effects Of Truck Platooning On Existing Bridges In Oregon, Patricia Oleson

Civil and Environmental Engineering Master's Project Reports

Truck Platooning (TP) involves managing multiple trucks closely together to reduce aerodynamic drag. While TP offers benefits such as fuel savings, emission reductions, and enhanced safety, it raises concerns for existing infrastructure. This study reviews literature on TP and conducts bridge analyses comparing representative truck platoon configurations allowed under Oregon law with current truck loadings. It also explores the effects of truck head spacing and bridge span lengths, utilizing the research results to calculate rating factors using real-world case studies. The objective is to identify truck platoon configurations that may exceed acceptable load levels for Oregon bridges. The findings will …


Design Of Bamboo Reinforced Concrete Beams Considering Variability In Tensile Strength Of Bamboo, Bibek Bhardwaj, Michael Stoner, Weichiang Pang Jul 2023

Design Of Bamboo Reinforced Concrete Beams Considering Variability In Tensile Strength Of Bamboo, Bibek Bhardwaj, Michael Stoner, Weichiang Pang

Publications

In recent years, the price of steel has soared, making steel reinforcement in concrete structures unaffordable for households in low-income countries. Seismic activities in low-income households, particularly those in developing countries, pose a significant threat to life and property to unreinforced concrete structures. The application of bamboo as an alternative to steel in reinforced concrete is still in its early stages of development. Unlike steel, bamboo is a natural material, and its structural properties vary greatly based on species, location, age, and geometric properties. Thus, the design of bamboo-reinforced concrete involves more uncertainties than steel-reinforced concrete. This research investigates the …