Engineering Commons^™

Recent Developments In Timber Design & Its Impact On Carbon Emissions, Raquel Jackson

Spectra Undergraduate Research Journal

This paper explores recent developments in timber building designs and its potential towards reducing carbon emissions. Carbon dioxide emissions are a growing issue worldwide as urbanization and industrialization continues to increase. The rising concentration of carbon dioxide emissions pose significant concerns towards public welfare and environmental health. Despite current methods to reduce greenhouse gasses, carbon emissions remain difficult to reduce from steel and concrete industries. Increasing timber use in building design is a possible solution. Increasing more timber in building design can help reduce carbon emissions due to the carbon-absorbing properties of the construction material. Timber as a construction material …

Spatiotemporal Variability In Total Dissolved Solids And Total Suspended Solids Along The Colorado River, Godson Ebenezer Adjovu, Haroon Stephen, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

The Colorado River is a principal source of water for 40 million people and farmlands in seven states in the western US and the Republic of Mexico. The river has been under intense pressure from the effects of climate change and anthropogenic activities associated with population growth leading to elevated total dissolved solid (TDS) and total suspended solid (TSS) concentrations. Elevated TDS- and TSS-related issues in the basin have a direct negative impact on the water usage and the ecological health of aquatic organisms. This study, therefore, analyzed the spatiotemporal variability in the TDS and TSS concentrations along the river. …

Evaluating The Potential Of Geopolymer Concrete As A Sustainable Alternative For Thin White-Topping Pavement, Sathvik S. Chandra, Pshtiwan Shakor, Sarwar Mohmmad, Bankole O. Awuzie, Atul K. Singh, Abishek Rauniyar, M Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

Introduction:

The construction industry uses a large quantity of natural materials in the production of concrete. Although attempts to incorporate green materials in concrete began years ago, not every building uses such materials today, and roadways, particularly, still rely on unsustainable materials.

Methods:

Therefore, this study used alternative materials, including fly ash, manufactured sand aggregates, and different molarities of alkaline activators, to incorporate waste byproducts in a geopolymer concrete white-topping pavement layer. Recent developments have led to the emergence of geopolymers as distinct classes of materials. In the 1990s, fly ash-based geopolymers became more popular than other kinds, as they …

Non-Destructive Means Of Predicting Masonry Prism Strength Using Ultrasonic Pulse Velocity (Upv), Connor J. Barlow

UNLV Theses, Dissertations, Professional Papers, and Capstones

Current ASTM standards call for grouted masonry prisms to be tested for compressive strength at 28-days to ensure compliance with the structural design. In the event of failing tests, the subject samples may require redesign or reconstruction which can pose problems due to ongoing development around and including the prisms between the time of placement and obtaining test results. The purpose of this research is to determine if the use of ultrasonic pulse velocity (UPV) testing can be utilized to determine a correlation between prism composite strength of the masonry prism with ultrasound readings as to provide preliminary means of …

Three-Dimensional Finite Element Numerical Analysis Of Closely Spaced Foundations Resting On Clay Soil Supported With A Geocell Mattress Embedded In A Fly Ash Layer, Yahia Iskander

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation studied several models supported by a geocell mattress filled with fly ash material as a filling material on top of a clay soil bed. Two square rigid steel plates presenting footings with different spacing between them were subjected to loading. The effect of spacing between footings on the function of the system was investigated by measuring the footings load and settlement.In the past, limited cases were studied for closely spaced footings. The subject of two closely spaced footings on clay soil supported by geocell has not been researched before. Most of the previous research was on sandy soil; …

A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microbial fuel cells (MFCs) are electrochemical devices that utilize microorganisms to convert organic matter into electrical energy. MFCs have been discussed to have potential application for sustainable wastewater treatment due to their ability to generate electricity while simultaneously treating contaminated water. To optimize MFC performance, numerical models can be used to understand the complex electrochemical and biological processes occurring in the system. In this study, a numerical model was developed to simulate the performance of MFCs under varying operating conditions and to investigate the performance of a MFC for treating wastewater fuel. More specifically, the MFC was modeled to oxidize …

Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection can promote safe drinking water. Chlorine and chloramines are the two most used disinfectants. While these disinfectants are effective in inactivating disease-causing pathogens, they also produce hazardous byproducts when they react with organic compounds (precursors). Nitrogenous disinfection byproducts (N-DBPs) are more toxic than their counterparts. The increased use of nitrogen-based agrochemicals and antibitics has led to their detection in different water sources. The presence of secondary amine and aniline in these compounds can act as a source of reactive nitrogen to form N-DBPs. In addition, the increased concentration of bromide in water systems due to anthropogenic activities can enhance …

Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fatalities, injuries, and property damage that result from traffic crashes impose a significant burden on society. Current research and practice in traffic safety rely on analysis of quantitative data from crash reports to understand crash severity contributors and develop countermeasures. Despite advances from this effort, quantitative crash data suffers from drawbacks, such as the limited ability to capture all the information relevant to the crashes and the potential errors introduced during data collection. Crash narratives can help address these limitations, as they contain detailed descriptions of the context and sequence of events of the crash. However, the unstructured nature …

Nexuscapes: A Landscape Approach For A Transdisciplinary Water-Energy-Food Nexus Decision-Making Process, Fortino Acosta

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study develops a reliable transdisciplinary framework for complex ecological and social systems by characterizing, mapping, typifying, assessing, and testing enhanced water-energy-food nexus scenarios under critical time constraints, specialized skills, or sensitive data accessibility. Detached management of limited essential resources like fresh water, reliable energy from renewable sources, and nutritious food can jeopardize regional economies and governance. Using a novel landscape approach, this study recommends a decision-making the framework focused on the circular economy that induces collaboration among diverse sectors and brings strategic coordination, specificity, and magnitude to the proposed solutions. The study elaborates on a decision-making tool that integrates …

Application Of Experimentally Calibrated Numerical Models For Prediction Of Composite Masonry Prism Strength, James Bristow

UNLV Theses, Dissertations, Professional Papers, and Capstones

The composite masonry prism test is a common laboratory test to determine the compressive strength of a set of masonry prisms (f’mt) to verify that the composite masonry prism assembly, and more importantly, the constituent materials, are providing adequate strength. While constructing masonry structures, the subcontractors, designers, and inspectors rarely provide continuous supervision or inspection of the construction process. Accordingly, verification of grout mix design, mixed proportions, proper installation of blocks, placement of mortar, dimensions of joints, etc. are more traditionally performed on a periodic basis instead. However, through the use and review of the composite masonry prism test results, …

Effects Of Particle Size And Replacement Proportion Of Post-Consumer Glass In Concrete, Negasi Gebremichael

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concrete, next to water, is the most used material (Gagg, 2014), which consumes natural or manufactured aggregates and resource-intensive cement. Concrete is also a more wasteful construction material than timber and steel. Depleting the natural resource due to aggregate extraction and the environmental unfriendliness of cement production have left the construction industry with no choice. Reducing waste, reusing, or recycling can help conserve natural resources. In this regard, the construction industry constantly seeks full or partial replacement of concrete aggregates and cement with recycled material. Glass is a candidate for replacing the three major components: cement, fine aggregate, and coarse …

Development And Application Of A Safety Index For Transit Stops: A Case Study From Las Vegas, Nevada, Rithesh Shivuni

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research developed a methodology to evaluate safety proximate to transit stops through a Safety Index, identified key factors associated with fatal crashes proximate to bus transit stops, and illustrated the applications of these using a case study based on the Las Vegas metropolitan area in Nevada, USA. The methodology is based on motor vehicle crashes that involve pedestrians recorded in the proximity of transit stops, and the severity of the crash outcomes. It focused on crashes which involved pedestrians that occurred within walking distances of individual transit stops. The severity of the crash outcomes was classified based on the …

Automated Approach For The Enhancement Of Scaffolding Structure Monitoring With Strain Sensor Data, Sayan Sakhakarmi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction researchers have made a significant effort to improve the safety of scaffolding structures, as a large proportion of workers are involved in construction activities requiring scaffolds. However, most past studies focused on design and planning aspects of scaffolds. While limited studies investigated scaffolding safety during construction, they are limited to simple cases only with limited failure modes and simple scaffolds. In response to this limitation, this study aims to develop an automated scaffold monitoring approach capable of monitoring large scaffolds. Accordingly, this study developed an automated scaffold safety monitoring framework that leverages sensor data collected from a scaffold, scaffold …

Cutting-Edge Technologies To Achieve A Higher Level Of Modular Construction – Literature Review, Seungtaek Lee, Jin Ouk Choi, Seung Song

Civil and Environmental Engineering and Construction Faculty Research

Cost overruns, schedule delays, and a shortage of skilled labor are common problems the construction industry is currently experiencing. Modularization and standardization strategies have the potential to resolve the various problems mentioned above and have been applied for various construction applications for a long time. However, the level of modularization remains low, and modular construction projects have not been getting the full benefits. Thus, this review investigated the cutting-edge technologies currently being utilized to develop the modular construction field. For this paper, qualified research papers were identified using predetermined keywords from previous related research papers. Identified literature was then filtered …

Hands-On Education Module For Modular Construction, 3d Design, And 4d Schedule, Kyle A. Kithas, Jin Ouk Choi

Architecture Faculty Research

A paradigm shift in teaching modular construction in higher education and K-12 is proposed as a means to increase the future adoption of the modular construction technique. To this effect, a new education module is presented to STEM educators. This education module is based on LEGOs and directed towards educators in the architecture, engineering, and construction (AEC) industry. The main objectives of the education module are to increase interest and knowledge of modular construction, acknowledge the benefits of using 3D design with 4D scheduling, and create a simulating hands-on educational opportunity. The education module is designed to allow participants to …

Applications Of Agent-Based Modeling (Abm) In Enhancing Facility Operation And Management, Ali Khodabandelu, Jee Woong Park

Civil and Environmental Engineering and Construction Faculty Research

Agent-based modeling (ABM), as a relatively new simulation technique, has recently gained in popularity in the civil engineering domain due to its uniquely advantageous features. Among many civil engineering applications, ABM has been applied to facility operation and management, such as energy consumption management, as well as the enhancement of maintenance and repair processes. The former studies used ABM to manage energy consumption through simulating human energy-related behaviors and their interactions with facilities, as well as electrical, heating, and cooling systems and appliances, while the latter used ABM to enhance maintenance process through facilitating coordination, negotiation, and decision making between …

An Agent-Based Framework For Investigating Safety-Productivity Tradeoff Of Construction Laborers Considering Risk-Taking Behavioral Heterogeneity, Ali Khodabandelu, Jee Woong Park, Seyedmohsen Kheyrandish

Civil and Environmental Engineering and Construction Faculty Research

Construction laborers and crews play a critical role in achieving a safe and productive construction site. Many past research studies used top-down approaches/perspectives for studying the impact of laborers' performance on overall construction site outputs with limited flexibility in accounting for laborers' various characteristics. However, the recent reap in computational advances allowed applications of bottom-up architectures, which can potentially incorporate heterogeneous characteristics of laborers' individual behavioral and decision-making features effectively. Accordingly, agent-based modeling (ABM), as a tool to leverage a bottom-up methodological approach, has been widely adopted by recent research. Existing literature investigated the influence of changes in laborers' behaviors …

Analysis Of A Long Volumetric Module Lift Using Single And Multiple Cranes, Ali Khodabandelu, Jee Woong Park, Jin Ouk Choi, Mahsa Sanei

Civil and Environmental Engineering and Construction Faculty Research

Industrialized and modular construction is a growing construction technique that can transfer a large portion of the construction process to off-site fabrication yards. This method of construction often involves the fabrication, pre-assembly, and transportation of massive and long volumetric modules. The module weight keeps increasing as the modules become more complete (with infill) to minimize the work at the site and, as higher productivity can be achieved at the fabrication shop. Thus, a volumetric module delivery gets more challenging and risky. Despite its importance, past research paid relatively insufficient attention to the problem related to the lifting of heavy modules. …

The Current State And Future Directions Of Industrial Robotic Arms In Modular Construction, Seung Ho Song, Jin Ouk Choi, Seungtaek Lee

Civil and Environmental Engineering and Construction Faculty Research

Industrial robotic arms are widely adopted in numerous industries for manufacturing automation under factory settings, which eliminates the limitations of manual labor and provides significant productivity and quality benefits. The U.S. modular construction industry, despite having similar controlled factory environments, still heavily relies on manual labor. Thus, this study investigates the U.S., Canada, and Europe-based leading modular construction companies and research labs implementing industrial robotic arms for manufacturing automation. The investigation mainly considered the current research scope, industry state, and constraints, as well as identifying the types and specifications of the robotic arms in use. First, the study investigated well-recognized …

Lessons Learned During The Early Phases Of A Modular Project: A Case Study Of Unlv's Solar Decathlon 2020 Project, Jin Ouk Choi, Seungtaek Lee, Eric Weber

Civil and Environmental Engineering and Construction Faculty Research

The U.S. Department of Energy conducts the Solar Decathlon competition as a student-based achievement that encourages sustainable design with energy efficiency and solar energy technologies. In the 2020 competition, the University of Nevada, Las Vegas (UNLV) team designed, fabricated, and constructed a net-zero modular house that applies innovative and highly efficient building technologies. This paper focused on the lessons learned during the early phases of this ongoing modular project. The research methodology included obtaining feedback from key project participants using a well-structured questionnaire. The results showed that the major items/challenges in the project’s planning phase included selecting the modular size, …

Urban Air Mobility: Envisioning Uam As An Integrated Form Of Future Transport - A Las Vegas Case Study, Osarodion Victory Igbinobaro

Hospitality Design Graduate Student Capstones

Rapid urbanization has resulted in more people moving to cities to live and work. By 2030, an estimated 5 billion people will live in urban areas representing about 60% of the world's population. This increase in population growth brings forth new mobility challenges and opportunities for city planners, importantly, the challenge of transporting people and goods to their destinations in the most efficient, safe, quick and sustainable manner.

Traffic congestion, greenhouse gas emissions from vehicles, the cost of maintaining existing and building new transportation infrastructure are among several reasons why many cities seek sustainable alternatives to compliment their existing transport …

Behavior Of Axially-Restrained Reinforced Concrete Beams Under High Sustained Loads, Ghazaleh Mehdikhan Laleh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Following column failure in a reinforced concrete (RC) frame structure, a progressive collapse may result if the beams supported by the failed column cannot generate an alternate path to carry the redistributed gravity loads. Past studies of the collapse resistance of RC frame beams were limited to their short-time load-carrying capacity. Axially restrained frame beams experience a compressive arch action as a beneficial load-resisting mechanism not considered in a conventional structural design. Due to the compressive arch action, the column failure may not cause an immediate collapse; however, gravity loads still act on the damaged structure, inducing high sustained stresses …

Flow Characteristics Through Granular Soil Influenced By Saline Water Intrusion: A Laboratory Investigation, Sudip Basack, Ghritartha Goswami, Hadi Khabbaz, M Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

The coastal geoenvironment initiates saline water intrusion into the freshwater aquifers, producing a geohydraulic problem. Such intrusion not only contaminates the fresh groundwater resources, making them unsuitable for human use, but also alters the hydraulic conductivity of the aquifer materials, which affects the coastal groundwater flow, influencing the water resources planning and management. Past investigations reveal that the groundwater flow can be linear or nonlinear depending upon the hydraulic gradient. Thus, the coefficients of nonlinear hydraulic conductivities are affected by saltwater intrusion. The present study focuses on an in-depth laboratory investigation into the influence of saltwater submergence on the nonlinear …

Application Of Lanthanides In Wastewater Treatment And Water Reuse, George William Kajjumba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the world’s population feed on grains (wheat, rice, and corn). Corn is as sensitive as it is productive. This thirsty, fast-growing plant goes into thermal shock in drought. In 2014, California lost over $2.2 billion in crop production due to drought. The Horn of Africa (in 2011) and Sahel (in 2012) faced humanitarian disasters due to food and water scarcity. The higher frequency of climate change and the erratic nature of rain, combined with underlying economic and social vulnerabilities, has meant that food and water scarcity is here to stay. To improve food and water scarcity, water reclamation …

Powering A Sustainable Electric Vehicle Future, Harmony Ruth, Jordan Brickman

Undergraduate Research Symposium Posters

Electric vehicle sales account for roughly 20% of total sales world wide and are projected to be 80% by 2050. China's electric vehicle market holds a 13.3% market share. China exported 550,000 electric vehicles in 2021. China represents a 54% share of the world's coal consumption as of 2020. Why study China on this issue? China is a major player in the World Economy.

Improving Active Learning Through Advanced Teaching Practices On An Online Course, Jin Ouk O. Choi

UNLV Best Teaching Practices Expo

Since the outbreak of the COVID, there has been a great need to advance learning experiences and opportunities for students when the courses are taught remotely. To address the need, the author incorporated the teaching strategies learned from the Culturally Relevant & Responsive Teaching (CRRT) fellows program supported by the NSF TRANSCEnD project. In Fall 2021, the author implemented multiple new teaching techniques and strategies in the CEM453-653 course, delivered entirely online. The specific teaching practices and technologies are: 1) Delivering lectures both live (synchronous) and recordings (asynchronous); 2) Using adaptive technology (Mentimeter & WebEx Poll) with real-time feedback; 3) …

The Improvement Of The Regional Regulatory Governance System For Radiation Risk Management: Spatial Analysis On Radiation Hazards In South Korea, Sangwon Lee, Jaewon Lim, Chan Goo Yi

Public Policy and Leadership Faculty Publications

Since the 2011 Fukushima nuclear power plant accident, nuclear regulators have strength-ened safety standards or decided to decommission the nuclear power plant. The vast majority of radiation is from nuclear power plants, so safety measures are also concentrated in nuclear power plants. Radioactive materials located much closer to the people are scattered around the nation. However, it is difficult for citizens to predict the radiation risk around them because regulatory agencies do not provide adequate information on radiation. The main goal of this study is to analyze the spatial distribution patterns of radioactive materials that serve as indicators for potential …

Transdisciplinarity In Experience Design: A Global Survey Of Higher Ed Programs In Exd/Xd, Yvonne Houy

Creative Collaborations

In our age of ubiquitous devices and digital media it is the perceived value of the end-to-end experience that brings people to a place. Designing inspiring and emotionally engaging end-to-end experiences requires experts in a wide range of disciplines committed to an interdisciplinary collaboration that can arrive at transdisciplinary design - the sum becomes greater than its parts.

Civil engineering, hospitality, business, psychology, digital User Experience (UX) design, and experience data analysis need to be seamless integrated with the fine and performing arts and design fields:

• Architecture, interior, landscape and sound design actively engage the senses.

• Graphic and fine arts …

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Improving Pedestrian Safety With The Implementation Of The Demand-Responsive Transverse Rumble Strip As A New Traffic Safety Countermeasure, Md Shakhawat Hossen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …