Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Relationship Between Standardization Critical Success Factors (Csfs) And Project Performance, Binit Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facility standardization strategy is defined as the development and use of consistent designs to align project stakeholders, objectives, and scope to capture and optimize schedule, cost, and value. The implementation and proper execution of this strategy can lead to considerable benefits, such as design once and reuse multiple times, along with learning curve benefits in fabrication, operations, and construction, as well as accelerated responds to schedule needs. Although standardization strategy is not a new idea; capital projects have failed to achieve high levels of facility standardization. The primary reason for this is the industry’s struggle to execute standardized projects successfully. …

Developing Lrfd Side Shear And End Bearing Resistance Factors For Design Of Axially Loaded Drilled Shafts In Soil Containing Caliche Layers Using The Monte Carlo Approach, Visar Farhangi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Conventional design and construction procedures of the drilled shafts (bored piles) are mainly developed for homogenous soils in the absence of highly cemented layers. However, the presence of competent and cementitious layers such as caliche deposits in soil profile can affect the resistance and settlement of pile foundations. This study concerns with the uncertainties on the resistance estimation of axially loaded drilled shafts in interaction with caliche layers The prime objective is to calibrate the side shear and end bearing resistance factors of axially loaded drilled shafts based on the soil characteristics of Nevada. The load-settlement responses of axially loaded …

Behavior Of Aged Reinforced Concrete Columns Under High Sustained Concentric And Eccentric Loads, Wenchen Ma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Columns are critical components resisting the collapse of a reinforced concrete (RC) frame structure subjected to high sustained loads. Research on columns under sustained high stresses is very limited. At material level, past creep tests were focused either on concrete with ages less than 90 days or under a sustained stress less than 70% of short-time strength. At structural component scale, virtually no experimental data can be found for the response of axially loaded RC columns subjected to high sustained loads exceeding 75% of column short-time strength with loading age greater than 200 days. Even if a few experiments were …

Investigation Of Bench-Scale Packed Bioreactor For Perchlorate Reduction In The Presence Of Co-Contaminants And High Salinity, Julia Ribeiro Rabello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Perchlorate (ClO4-), commonly found as a salt, is naturally occurring in nature and is found in natural nitrate deposits (such as the Chilean nitrate). Perchlorate anion is considered an inhibitor of iodine by the thyroid gland, reducing the production of thyroid hormones. The latest action by the USEPA was to not determine a national drinking water standard for perchlorate. However, the states still have their own regulations on perchlorate concentration in drinking water. Contaminated sites with high concentrations of perchlorate (ppm levels) are associated with historic perchlorate manufacture and use, while those with low concentrations (ppb levels) are found in …

Geometric Quality Assessment Of A Modular House Using Bim And Photogrammetric Point Clouds, Preetam Kapsikar

UNLV Theses, Dissertations, Professional Papers, and Capstones

As-built documentation of modular structures is an important set of records for a project, that consist of construction drawings and specifications, project design modifications, prefabrication, and component assembly. In particular, manual geometric quality assessments of a structure’s prefabricated components are generally fraught with errors, making it extremely difficult to compare the as-built construction with the specified drawings, which affects the project. Furthermore, if the prefabricated components are manufactured with errors, this can result in construction schedule delays and high additional costs due to rework. Several technologies, such as point cloud data generated using laser sensors and LiDAR, have been developed …

Impact Of Disadvantaged Business Enterprises Participation And Mobilization Cost On Highway Project Performance, Shristy Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction practitioners have their goals to complete projects within time without exceeding the allocated budget. However, studies have shown many projects overrun their allocated budget and face delays due to numerous reasons. Some of the main reasons are lack of efficient construction and financial resource management, lack of proper planning, and unavailability of new construction technologies, as well as ineffective supervision and communication, design changes, and unskilled workers. In some studies, mobilization costs, along with the participation of Disadvantaged Business Enterprises (DBEs) in projects were identified as factors affecting the cost and schedule performance of construction projects. However, no statistical …

Alternate Novel Thermal Structure Interaction Designs Of Molten Salt Shell Structures At High Temperatures Ranging From 565˚C To 700˚C, Nathan David Tyrrell Loyd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Excess energy from solar power stations and other baseline power production methods canbe stored in molten salts (MS) in the 565°C range, therefore allowing the use of large containers to store energy for up to a week and generate eight hours of electricity or more to be used during peak demand hours, at night, or adverse weather conditions, depending on the container size. Supported by Office of Naval Research (ONR), this research presents a survey of molten salt properties used in solar power storage, as well as the history of molten salt usage for energy storage and production for nuclear …

Three-Dimensional (3d) Characterization Of The Middle Ordoovician (Darriwilian) Strata In The Southern Great Basin, Western United States, Uday Mohamed Baheej Kara Ali

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carbonates are mostly produced in shallow-marine environments and their deposition is sensitive to water depth changes on carbonate platforms. The water depth in depositional environments of a particular carbonate platform is controlled by the interplay of eustatic sea-level change, tectonic subsidence, platform morphology, and depositional rate. Due to the morphological variations of carbonate platforms in different tectonic settings, facies distribution across carbonate platforms varies significantly even during a single eustatic sea-level cycle. Carbonate platforms developed on passive continental margins are thought to be the most stable platforms and their facies distribution is commonly taken as examples in textbook depositional models. …

Temporal And Spatial Analysis Of The Wage Gap For Women And Underrepresented Minorities In The Architecture, Engineering, And Construction (Aec) Workforce, Saba Nikkhah Manesh

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Architecture, Engineering, and Construction (AEC) industry has failed to solve persistent labor shortage problems or to fill the labor demand in the workforce by recruiting from untapped/underrepresented groups such as Women and Underrepresented Minorities (WUMs). There have been several studies on diversity and inclusion in the AEC industry, but the issue still persists, as the AEC industry has failed to solve these issues. If the industry better understands the status of wage gaps by gender and race, as well as how the industry has performed in terms of providing comparable wages for the workforce over time, along with the …

A Hybrid Experimental-Numerical Study On The Flow Topology In The Confluence Hydrodynamics Zone Of An Open Channel With Lateral Drainage Pipe Discharge, Mohammad Nazari-Sharabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

To avoid disrupting the flow in flood control channels with lateral drainage pipes, or impact channel capacity, confluences are constructed at small angles (Maximum 30○). These small angles are costly to construct, since they require more real estate than greater angles.

By performing several laboratory experiments in the Fluid Dynamics Laboratory of the University of Nevada, Las Vegas (UNLV) and utilizing a numerical model (FLOW-3D), this study investigated the impact of submerged lateral drainage pipe discharges into rectangular open channels, on flow topology in the confluence hydrodynamics zone (CHZ). This was done across a range of channel widths, flow rates, …

Acoustic Sonolysis Of Antibiotics In Water, Natalie Pinon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Antibiotic resistance is a prominent issue in the world today. It is said by the Centers for Disease Control and Prevention that it is one of the major public health challenges we face today. Predominantly, antibiotic resistance is growing because conventional wastewater treatment processes are not able to completely break down antibiotics. As bacteria are exposed to such antibiotics, which don’t kill them due to selective pressure, they become immune and develop resistance which is a huge health concern. To prevent this from occurring, antibiotics need to be removed from hospital wastewater. Sonication is a promising technology that can be …

Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations of groundwater in a former industrial perchlorate manufacturing site have shown high contamination with perchlorate, chlorate, nitrate, hexavalent chromium (Cr (VI)), and chloroform (CF) with levels greater than 3,000, 30,000, 300, 100, and 4 mg/L, respectively. Remediation efforts using biological reduction to desired contaminant levels at this site has been challenging due to high contaminant concentrations, and high total dissolved solids (TDS). Furthermore, removal of Cr(VI) and CF in the presence of nitrate, chlorate, and perchlorate has not been examined at the contaminated site. Nano-scale Zero-Valent-Iron (NZVI) has been effective at reducing groundwater contamination both with and without bacterial …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Public-Private Partnership Contract Framework Development And Project Performance Analysis Compared To Design-Build In The Us Highway Projects, Medya Fathi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction projects can be delivered through various approaches; nevertheless, all practitioners and involved parties have a mutual goal, which is completing the project within the original scope, defined budget, and schedule. Reviewing the literature on public-private partnership (PPP), many efforts have been made covering different research areas, including policies, risks, roles and responsibilities, and finance. However, a study involving the development of a framework for PPP contracts, and quantitative assessment of project performance associated with PPP highway projects in the US is lacking. Therefore, this research fills such a noticeable gap in the body of knowledge on the PPP delivery …

High Salinity, High Concentration Perchlorate Reduction In The Presence Of Hexavalent Chromium, Nitrate, And Chlorate, Nicole Martin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Perchlorate is a chemically stable anion which was used as an oxidizer in rocket propellant and explosives throughout the 1950’s and 1960’s. While natural sources of perchlorate exist, perchlorate in the environment is primarily a result of contamination from anthropogenic processes. Perchlorate contamination has now been identified in at least 45 states and is hazard to human health due to perchlorate’s ability to interfere with uptake of iodine in the thyroid gland. One of the most common and cost effective treatment methods for perchlorate remediation is biological reduction—utilizing bacteria to enzymatically reduce perchlorate into chloride and oxygen.

The purpose of …

Examining The Effectiveness Of A 4d Schedule And A Virtual Reality Model On A Modular Project: Unlv Solar Decathlon Case, Rajarshi Ghimire

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of a 4D schedule as technological advancement has brought significant improvement to the planning and execution of construction projects, through visualizing stepwise construction progress, following a sequence of pre-planned activities, and finalizing a baseline schedule with necessary changes. Moreover, the application of virtual reality (VR) to create interactive 3D models of a planned structure has made it possible to make a detailed planning of any construction project. Because of these benefits, the use of 4D schedules and VR in the construction industry has increased drastically, leading to improved planning and execution. However, past studies have given little attention …

Development Of Natural Perlite Based Concrete For Sustainable Construction, Seyedmahmoud Motaharikarein

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study aimed to partially replace Portland Cement (PC) with environmentally friendly binders capable of improving the longevity of concrete. The new binders consisted of different proportions of natural pozzolan (perlite) with various fineness and particle size distributions. A step-by-step research program was designed to: (1) discover the optimum fineness of perlite powder and its optimum replacement level with cement; (2) investigate the rheological properties of the perlite-containing mixtures, and examine whether this binder can be used in selfconsolidating concrete; and (3) assess the weaknesses of the new binder, and improve its deficiencies by using nanomaterials such as nano-silica. The …