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

Engineering Commons™

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

Civil and Environmental Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5491 - 5520 of 39916

Full-Text Articles in Engineering

Enhancement Of Heat-Cured Cement Paste With Tannic Acid, Jinrui Zhang, Ziye Kang, Youzhi Yang, Biqin Dong, Hongyan Ma Mar 2023

Enhancement Of Heat-Cured Cement Paste With Tannic Acid, Jinrui Zhang, Ziye Kang, Youzhi Yang, Biqin Dong, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Improvement of Cement-Based Materials' Performance by Natural Organic Compounds Can Greatly Promote the Green and Sustainable Development of the Construction Industry. However, Such Compounds Are Not Widely Used Yet Because of their Retarding Effect on Cement. in This Study, the Retardation Effect of Tannic Acid (TA, a Well-Known Retarding Compound) is overcome and the Enhancing Effect is Achieved by Adding Less Than 0.1% Content and Curing Samples in Thermal Regime. Then the Mechanism of TA Enhancing Heat-Cured Cement Pastes is Studied Systematically. Mechanical Properties Results Suggest that Addition of 0.025% TA Can Reduce the Compressive and Flexural Strengths of …

Go to article

Application Of Connected Vehicle Data To Assess Safety On Roadways, Mandar Khanal, Nathaniel Edelmann Mar 2023

Application Of Connected Vehicle Data To Assess Safety On Roadways, Mandar Khanal, Nathaniel Edelmann

Civil Engineering Faculty Publications and Presentations

Using surrogate safety measures is a common method to assess safety on roadways. Surrogate safety measures allow for proactive safety analysis; the analysis is performed prior to crashes occurring. This allows for safety improvements to be implemented proactively to prevent crashes and the associated injuries and property damage. Existing surrogate safety measures primarily rely on data generated by microsimulations, but the advent of connected vehicles has allowed for the incorporation of data from actual cars into safety analysis with surrogate safety measures. In this study, commercially available connected vehicle data are used to develop crash prediction models for crashes at …

Go to article

Physicochemical Technique In Municipal Solid Waste (Msw) Landfill Leachate Remediation: A Review, Hamidi Abdul Aziz, Siti Fatihah Ramli, Yung-Tse Hung Mar 2023

Physicochemical Technique In Municipal Solid Waste (Msw) Landfill Leachate Remediation: A Review, Hamidi Abdul Aziz, Siti Fatihah Ramli, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

Leachate generation is among the main challenging issues that landfill operators must handle. Leachate is created when decomposed materials and rainwater pass through the waste. Leachate carries many harmful pollutants, with high concentrations of BOD, COD, colour, heavy metals, ammoniacal nitrogen (NH3-N), and other organic and inorganic pollutants. Among them, COD, colour, and NH3-N are difficult to be completely eliminated, especially with a single treatment. They should be handled by appropriate treatment facilities before being safely released into the environment. Leachate remediation varies based on its properties, the costs of operation and capital expenditures, as well as the rules and …

Go to article

A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A Sarkar, Hossam Abohamer, Mohammad Oyan Mar 2023

A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A Sarkar, Hossam Abohamer, Mohammad Oyan

Data

The presence of moisture beneath the pavement surface is a matter of great concerns as it is responsible for significant distresses such as asphalt concrete (AC) stripping, fatigue cracking, rutting, and poor durability of asphalt mixes. The objective of this study was to evaluate and recommend an asphalt mixture design that would provide superior performance against AC stripping and cracking. To achieve this objective, a laboratory test factorial was developed to evaluate the use of nanomaterials, emerging anti-stripping agents, warm-mix asphalt technologies, and adhesion promotors. In the experimental program, the modified Lottman test (AASHTO T 283) and the Indirect Tensile …

Go to article

Existing Transportation Infrastructure In The Central Appalachian Basin To Support Core-Cm, Bryan Gibson, Robin Baskette, Doug Kreis Mar 2023

Existing Transportation Infrastructure In The Central Appalachian Basin To Support Core-Cm, Bryan Gibson, Robin Baskette, Doug Kreis

Kentucky Transportation Center Research Report

Stretching from Tennessee northeastward through southwestern Pennsylvania, the Central Appalachian Basin’s economic fortunes have long depended on coal production. However, as the U.S. has increasingly turned toward new forms of energy to generate electricity, the region’s economy has faced inexorable headwinds. Yet, what is clear is that the extractive industries are likely to play a key role in shaping the basin’s economy in the years to come. Taking this assumption as a starting point, this paper discusses how well current transportation infrastructure can support expanded us of the basin’s carbon ore, rare earth, and critical minerals (CORE-CM), other minerals, and …

Go to article

Evaluation Of A Droplet Spraying/Misting System To Enhance Leachate Evaporation And Reduce Leachate Treatment Costs: A Case Study At The Three Rivers Solid Waste Authority Landfill, Kaitlen Drafts, Suzie Boxman, Scott Ribes, Mike Terry, Bryan Staley, Nicole Berge Mar 2023

Evaluation Of A Droplet Spraying/Misting System To Enhance Leachate Evaporation And Reduce Leachate Treatment Costs: A Case Study At The Three Rivers Solid Waste Authority Landfill, Kaitlen Drafts, Suzie Boxman, Scott Ribes, Mike Terry, Bryan Staley, Nicole Berge

Faculty Publications

Three Rivers Solid Waste Authority (TRSWA) operates a MSW landfill outside Jack-son, South Carolina at which leachate is stored in a collection pond then trucked to a local wastewater treatment plant (WWTP) for treatment. This landfill operates a droplet spraying/misting system (referred to as the Lilypad system) to enhance leachate evaporation and ultimately reduce the quantity of leachate in the pond that requires subsequent treatment. Little work investigating the efficacy in using such a system to enhance leachate evaporation has been reported. The overall goal associated with this study was to quantify the amount of evaporation enhanced by the droplet …

Go to article

Performance Of High Early-Strength Materials Used In Concrete Bridge Repair, Zina Ebrahim, Fray F. Pozo-Lora, Zachary Benson, Mohammad Mastali, Marc Maguire, Jiong Hu Mar 2023

Performance Of High Early-Strength Materials Used In Concrete Bridge Repair, Zina Ebrahim, Fray F. Pozo-Lora, Zachary Benson, Mohammad Mastali, Marc Maguire, Jiong Hu

Nebraska Department of Transportation: Research Reports

High early-strength materials are widely used for rapid concrete patching projects to limit road closure time and traffic obstruction. This research investigated the field performance of multiple high early-strength materials used in maintenance projects across Nebraska. Data from high early-strength products included in the state’s approved product list were collected and compared to field performance. In addition, a survey was prepared and distributed to the surrounding states to understand standard practices related to appropriate specifications of these materials that can be later used to develop specifications for the utilization of high early strength materials in Nebraska based on experimental and …

Go to article

Uhpc Decked I-Beam For Accelerated Bridge Construction, George Morcous, Maher K. Tadros Mar 2023

Uhpc Decked I-Beam For Accelerated Bridge Construction, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

Ultra-High-Performance Concrete (UHPC) is an excellent material for bridge construction due to its exceptional durability and superior mechanical properties. Several Departments of Transportations (DOTs), including NDOT, have limited the use of UHPC in bridge construction to joints and connections between bridge components due to the relatively high materials cost of commercially UHPC products. Recently, NDOT has sponsored a research project to develop a non-proprietary UHPC using local materials to reduce materials cost and ensure its availability to local contractors and precast producers. The project was completed successfully and an economical UHPC mix that satisfied all workability, durability, and strength requirements …

Go to article

Protection Of Linear Assets In Arctic Regions Using Basic Expeditionary Airfield Resources (Polaar Bear), Christopher P. Lintz Mar 2023

Protection Of Linear Assets In Arctic Regions Using Basic Expeditionary Airfield Resources (Polaar Bear), Christopher P. Lintz

Theses and Dissertations

In the 2018 United States National Defense Strategy, the Department of Defense mandated that forces are to be more dynamic and decentralized. The Arctic region was a key topic that was addressed. This means that in the future, it is possible that personnel will need to operate in the Arctic, away from the standard built up infrastructure, to enhance the capabilities of the Air Force and enable the power projection required for mission execution. When establishing a new location, water systems are one of the first requirements for setting up a temporary base infrastructure. However, the Air Force’s current expeditionary …

Go to article

Mission Dependency Weighted Water Distribution Networks, Payten A. Connally Mar 2023

Mission Dependency Weighted Water Distribution Networks, Payten A. Connally

Theses and Dissertations

How does the United States Air Force (USAF) assess and plan to replace their most critical drinking water infrastructure? The historical answer is to wait for it to break and then replace or repair the failed pipe. While this has been the process in the past, it is no longer a sustainable approach with resources and funding becoming more constrained in the public and private sectors, and aging assets approaching the end of their usable life. The USAF has taken the first step in asset management to identify their underground water lines, but they have not developed ways to convey …

Go to article

Investigation Of Possible Alternatives To Fossil Fuels For The Dod In Indopacom, Terrence W. Caploe Mar 2023

Investigation Of Possible Alternatives To Fossil Fuels For The Dod In Indopacom, Terrence W. Caploe

Theses and Dissertations

Energy security, greenhouse gas (GHG) emissions, and geopolitical concerns in the south pacific require diversification and independence from legacy energy sources in the Indo-Pacific Combatant Command (INDOPACOM) area of operation (AO). The United States Government has placed mandates and directives to minimize the impacts of GHG on the climate. These orders require divestment from GHG producing fuel sources by 2050. This study compares the energy alternates to Jet Propulsion 8 (JP8) as Ammonia, Hydrogen, and Lithium-ion Batteries. The study uses Life Cycle Assessment (LCA) tools to determine the environmental impacts of various energy candidates in the South Pacific. These results …

Go to article

Timber Box Header Using Bamcore Side Panels: A Senior Project Study, Jonathan Frank Herrera Mar 2023

Timber Box Header Using Bamcore Side Panels: A Senior Project Study, Jonathan Frank Herrera

Architectural Engineering

The purpose of this study was to begin development of a composite box header that was able to span long openings with minimal deflection. The headers in study were comprised of BamCore side panels, nailed top and bottom each face to a 2x6 top plate, and a header of multiple specified sizes. The 2x6 top plate and headers ranging from a 6x6 to a 6x12 were made up of Douglas Fir-Larch, No.1. Analysis was performed assuming 10d common nailing at top and bottom of the BamCore side panels. Initial analysis of a composite box header was performed and analyzed as …

Go to article

Building Artificial Reefs From Recycled Construction Materials: A Feasibility Study, Nicholas H. Lew Mar 2023

Building Artificial Reefs From Recycled Construction Materials: A Feasibility Study, Nicholas H. Lew

Construction Management

Naturally occurring reefs are some of the world’s most biologically diverse ecosystems formed by jagged rocks tucked slightly below sea level. In recent years global warming began to pose a major threat to many reef habitats. Most relevant is the increase in surface seawater temperatures that cause coral to bleach, taking away major food sources for larger marine species. Researchers have combated this by deploying artificial reefs in substitution for naturally formed limestone rock formations in order to promote the expansion of coastal habitats. This project specifically aims to utilize construction waste towards the production of artificial reefs, effectively upcycling …

Go to article

Growing Grounds Farm, Santa Maria - Greenhouse Planter Bench Tables, Joseph Miller Mar 2023

Growing Grounds Farm, Santa Maria - Greenhouse Planter Bench Tables, Joseph Miller

Construction Management

This paper covers the planning, fundraising, design, construction, and installation associated with building the Growing Grounds Farm of Santa Maria greenhouse planter bench tables. Growing Grounds prides itself on nourishing the local community through a combination of horticulture therapy, and vocational training for individuals with severe and persistent mental illness. The farm offers various opportunities for socialization and interaction with coworkers and customers. After meeting with the farm managers, Anna Wiens and Keith Bartlett, it was clear that this project was of the highest priority. Upon agreement of the project, the farm managers and I determined the future vision and …

Go to article

Las Vegas Commercial Contractors' Mitigation Techniques For Inflationary Impacts, Kannen I. Caldwell Mar 2023

Las Vegas Commercial Contractors' Mitigation Techniques For Inflationary Impacts, Kannen I. Caldwell

Construction Management

Recent rises in inflation have impacted global business. The construction industry in particular has experienced a decrease in already slim margins due to a plethora of factors. Employers have had difficulty affording increased labor rates to accommodate higher costs of living, ultimately leading to a labor shortage in many areas. Supply chain issues are a product of this labor shortage, but also a myriad of other inflation related issues like the price of gas and global trade agreements. This has led to dramatically increased lead times and has posed major supply chain management issues for project management teams. Construction professionals, …

Go to article

Feasibility Of Funding Construction-Related Projects With Cryptocurrencies, Farbod Pourdehmobed Mar 2023

Feasibility Of Funding Construction-Related Projects With Cryptocurrencies, Farbod Pourdehmobed

Construction Management

The current method of acquiring funds for construction projects consists of loans and/or a board of investors. With the emergence of the cryptocurrency industry in the past five to ten years, an influx of cash has been inserted into the market and is simply being held captive by government regulations. With development and construction being an attractive investment for most anyone, these "crypto billionaires" are insistent on financing possible projects. The issue lies within the construction industry and the possibly outdated financial system and whether it is capable of adhering to certain requirements that come with the usage of crypto …

Go to article

The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson Mar 2023

The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

While the eddy covariance (EC) technique is a well-established method for measuring water fluxes (i.e., evaporation or 'evapotranspiration’, ET), the measurement is susceptible to many uncertainties. One such issue is the potential underestimation of ET when relative humidity (RH) is high (>70%), due to low-pass filtering with some EC systems. Yet, this underestimation for different types of EC systems (e.g. open-path or closed-path sensors) has not been characterized for synthesis datasets such as the widely used FLUXNET2015 dataset. Here, we assess the RH-associated underestimation of latent heat fluxes (LE, or ET) from different EC systems for 163 sites in …

Go to article

Urban Densification At Twin Creeks Apartments: High-Density Living With Low-Density Luxuries, Ryan Griswold Mar 2023

Urban Densification At Twin Creeks Apartments: High-Density Living With Low-Density Luxuries, Ryan Griswold

Construction Management

Urban sprawl is characterized by the rapid growth of the extent of cities and towns. In the United States, urban sprawl is greatly influenced by housing density. In the past half-century, developers have favored constructing and consumers have preferred living in neighborhoods of detached, single-family homes. This is because low-density living provides more housing services, or additional benefits, than most high-density developments, such as apartments and townhomes. Residents of low-density living often have more privacy, outdoor space, interior natural light, and many other benefits over residents of higher-density developments. However, Twin Creeks Apartments, located in San Luis Obispo, California, is …

Go to article

New Bike Path On Highland Drive, Christian T. Pedersen Mar 2023

New Bike Path On Highland Drive, Christian T. Pedersen

Construction Management

The purpose of the following paper is to provide a breakdown of the preconstruction and construction processes for a new bike path to be built on Highland Drive. Studies about the selected construction method and materials needed to complete the project are included. Soil-cement will be at the forefront as it offers the cheapest and most efficient way for the proposed new path to be constructed. The explanation for why soil-cement was chosen along with the various other ways in which it can be used are included. One concern the paper will address is the fact that the current bike …

Go to article

Parental And Family Leave In The California Construction Industry, Hailee Malins Mar 2023

Parental And Family Leave In The California Construction Industry, Hailee Malins

Construction Management

Struggles between work life balance often result in lower levels of job and life satisfaction, and higher rates of inefficiency and employee turnover, with varying impact on employees based on seniority, gender and parenthood. Policies such as paid parental leave have shown positive effects on work life balance, but there is a lack of information on leave policies within the American construction industry. Focusing on California, this research aimed to determine employee's understanding, use and acceptance of these leave policies. Using a survey, we gain a better understanding of these goals. Rates of confidence in knowledge of paternal and family …

Go to article

Moisture Sources Of Precipitation In The Great Lakes Region: Climatology And Recent Changes, Zhao Yang, Yun Qian, Pengfei Xue, Jiali Wang, T. C. Chakraborty, William J. Pringle, Jianfeng Li, Xiaodong Chen Mar 2023

Moisture Sources Of Precipitation In The Great Lakes Region: Climatology And Recent Changes, Zhao Yang, Yun Qian, Pengfei Xue, Jiali Wang, T. C. Chakraborty, William J. Pringle, Jianfeng Li, Xiaodong Chen

Michigan Tech Publications, Part 1

Given the critical role of precipitation on hydroclimate, we quantified the contributions of moisture source regions to precipitation in the Great Lakes Region (GLR) using multiple reanalysis data sets. Results show that the Great Plains (GPs) and the GLR itself are the primary sources of moisture. The moisture sources for the double peaks in the GLR precipitation that occur in June and September are identified, which is caused by a shift in the peak timing of moisture contribution from the GLR and GPs. In particular, moisture from the GPs contributes more to the heavy precipitation, while moisture from the GLR …

Go to article

Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow Mar 2023

Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow

School of Social Work Faculty Publications

The current global focus on transportation equity, as well as a move towards smart mobility, highlights the need for more representative transportation data to inform transportation planning. In this case study, an interdisciplinary research team describes the process of refining and evaluating the utility of a transportation daily diary mobile-phone-based app. The process is framed through transportation equity and diverse key stakeholder engagement. The team custom-designed the app, MyAmble, to capture successful transportation behaviors, as well as latent demand, defined as travel not taken but desired, among underserved populations. Stakeholder focus groups with subject matter expert (n = …

Go to article

The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden Mar 2023

The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden

Theses and Dissertations

Bacillus anthracis has been a biological threat for decades and after the 2001 terrorist attack via the U.S. Postal Service where five people died, there was heightened awareness and inquiry on the subject (Goel, 2015; Greenberg et al., 2010; Nicholson & Galeano, 2003; Spotts Whitney et al., 2003). The health risk to humans makes this biological agent, a Tier 1 agent and one of the most likely to be used in an attack (Anthrax as a Bioterrorism Weapon | CDC, n.d.; Driks, 2009; Rose & Rice, 2014). B. anthracis is one of most resistant and potent biological warfare agents as …

Go to article

A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A. Sarkar, Hossam Abohamer, Mohammad Oyan Mar 2023

A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A. Sarkar, Hossam Abohamer, Mohammad Oyan

Publications

The presence of moisture beneath the pavement surface is a matter of great concerns as it is responsible for significant distresses such as asphalt concrete (AC) stripping, fatigue cracking, rutting, and poor durability of asphalt mixes. The objective of this study was to evaluate and recommend an asphalt mixture design that would provide superior performance against AC stripping and cracking. To achieve this objective, a laboratory test factorial was developed to evaluate the use of nanomaterials, emerging anti-stripping agents, warm-mix asphalt technologies, and adhesion promotors. In the experimental program, the modified Lottman test (AASHTO T 283) and the Indirect Tensile …

Go to article

Predicting And Validating The Load-Settlement Behavior Of Large-Scale Geosynthetic-Reinforced Soil Abutments Using Hybrid Intelligent Modeling, Muhammad Nouman Amjad Raja, Syed Taseer Abbas Jaffar, Abidhan Bardhan, Sanjay Kumar Shukla Mar 2023

Predicting And Validating The Load-Settlement Behavior Of Large-Scale Geosynthetic-Reinforced Soil Abutments Using Hybrid Intelligent Modeling, Muhammad Nouman Amjad Raja, Syed Taseer Abbas Jaffar, Abidhan Bardhan, Sanjay Kumar Shukla

Research outputs 2022 to 2026

Settlement prediction of geosynthetic-reinforced soil (GRS) abutments under service loading conditions is an arduous and challenging task for practicing geotechnical/civil engineers. Hence, in this paper, a novel hybrid artificial intelligence (AI)-based model was developed by the combination of artificial neural network (ANN) and Harris hawks’ optimisation (HHO), that is, ANN-HHO, to predict the settlement of the GRS abutments. Five other robust intelligent models such as support vector regression (SVR), Gaussian process regression (GPR), relevance vector machine (RVM), sequential minimal optimisation regression (SMOR), and least-median square regression (LMSR) were constructed and compared to the ANN-HHO model. The predictive strength, relalibility and …

Go to article

Heat Transfer Augmentation And Entropy Generation Analysis Of Microchannel Heat Sink (Mchs) With Symmetrical Ogive-Shaped Ribs, Kareem Akhtar, Haseeb Ali, Israr Ud Din, Azed Abbas, Muhammad Zeeshan Zahir, Faraz Ahmad, Fayyaz Alam, Nasir Shah, Muhammad Aamir Mar 2023

Heat Transfer Augmentation And Entropy Generation Analysis Of Microchannel Heat Sink (Mchs) With Symmetrical Ogive-Shaped Ribs, Kareem Akhtar, Haseeb Ali, Israr Ud Din, Azed Abbas, Muhammad Zeeshan Zahir, Faraz Ahmad, Fayyaz Alam, Nasir Shah, Muhammad Aamir

Research outputs 2022 to 2026

This study proposes the use of symmetrical ogive-shaped ribs on the walls of microchannel heat sinks (MCHS) to improve their thermal performance with minimal pressure drop. The ribs are arranged in three different configurations: ribs attached to all channel walls (MC-SAWR), ribs attached to side channel walls (MC-SSWR), and ribs attached to the bottom channel wall (MC-SBWR). Numerical investigations are conducted using the laminar conjugate heat transfer model to study the flow and heat transfer characteristics of the MCHS. The augmentation entropy generation number and thermal enhancement factor criterion are used to quantify the overall hydrothermal performance of the MCHS. …

Go to article

Response Of The Metastable Pitting Corrosion Of Laser Powder Bed Fusion Produced Ti–6al–4v To H+ Concentration Changes, Yuwei Cui, Liangyu Chen, Liqiang Wang, Jun Cheng, Laichang Zhang Mar 2023

Response Of The Metastable Pitting Corrosion Of Laser Powder Bed Fusion Produced Ti–6al–4v To H+ Concentration Changes, Yuwei Cui, Liangyu Chen, Liqiang Wang, Jun Cheng, Laichang Zhang

Research outputs 2022 to 2026

There is limited research on metastable pitting corrosion in an acidic environment, and acid is a major challenge for material corrosion. Therefore, this work investigated the metastable pitting corrosion of laser powder bed fusion (LPBF)-produced Ti–6Al–4V, in Hank’s solution, at different pH values (pH = 3, 5, and 7). This work investigated the effect of acid on the characteristics of passive films, as well as the change in metastable pitting behavior. Based on the results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS), the passive film will be inhibited and dissolved under the influence of H+. The higher …

Go to article

Two−Dimensional Nanomaterials Confined Single Atoms: New Opportunities For Environmental Remediation, Yu Yin, Lei Shi, Shu Zhang, Xiaoguang Duan, Jinqiang Zhang, Hongqi Sun, Shaobin Wang Mar 2023

Two−Dimensional Nanomaterials Confined Single Atoms: New Opportunities For Environmental Remediation, Yu Yin, Lei Shi, Shu Zhang, Xiaoguang Duan, Jinqiang Zhang, Hongqi Sun, Shaobin Wang

Research outputs 2022 to 2026

Two−dimensional (2D) supports confined single−atom catalysts (2D SACs) with unique geometric and electronic structures have been attractive candidates in different catalytic applications, such as energy conversion and storage, value−added chemical synthesis and environmental remediation. However, their environmental applications lack of a comprehensive summary and in−depth discussion. In this review, recent progresses in synthesis routes and advanced characterization techniques for 2D SACs are introduced, and a comprehensive discussion on their applications in environmental remediation is presented. Generally, 2D SACs can be effective in catalytic elimination of aqueous and gaseous pollutants via radical or non−radical routes and transformation of toxic pollutants into …

Go to article

Evaluating Automated Truck Platoon (Atp) Deployment For The Los Angeles–Inland Empire Trade Corridor Enhancement, Shailesh Chandra, Aastha Chaudhary, Prakhar Srivastava, Jose Torres-Aguilera Mar 2023

Evaluating Automated Truck Platoon (Atp) Deployment For The Los Angeles–Inland Empire Trade Corridor Enhancement, Shailesh Chandra, Aastha Chaudhary, Prakhar Srivastava, Jose Torres-Aguilera

Mineta Transportation Institute

The California Freight Mobility Plan 2020 lists the Los Angeles-Inland Empire trade corridor region as a prominent industrial hub experiencing an increase in freight flows. The California Freight Mobility Plan also regards automated truck platoon (ATP) as an emerging opportunity to minimize congestion on the trade corridor routes. Percentage change in accessibility from 2022 (“without” ATP) to 2040 (“with” ATP) is calculated for the eighteen industry sectors of the Los Angeles-Inland Empire trade corridor. The application of the accessibility formulation was carried out with data on travel time from I-710 and I-10 within Los Angeles County. The findings suggest that …

Go to article

Modeling Vehicle-Miles Of Travel Accounting For Latent Heterogeneity, Fatemeh Nazari, Abolfazl (Kouros) Mohammadian Mar 2023

Modeling Vehicle-Miles Of Travel Accounting For Latent Heterogeneity, Fatemeh Nazari, Abolfazl (Kouros) Mohammadian

Civil Engineering Faculty Publications

Vehicle use is associated with negative externalities such as traffic congestion, air pollution, and greenhouse gas emissions. Particularly in the U.S. as a car-oriented country, vehicle use — in terms of vehicle-miles of travel (VMT) — has been on the rise and is projected to increase in the future. To curb the VMT growth and mitigate the associated externalities, policy makers can design informed strategies based on VMT predicted by vehicle use models. However, traditional vehicle use models capture merely the observed heterogeneity across vehicle decision making units (e.g., individuals) and ignore the latent or taste heterogeneity sourced in …

Go to article

First Prev Next Last