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2013

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Full-Text Articles in Engineering

College Of Engineering Senior Design Competition Fall 2013, University Of Nevada, Las Vegas Dec 2013

College Of Engineering Senior Design Competition Fall 2013, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Drainage Structure Datasets And Effects On Lidar-Derived Surface Flow Modeling, Ruopu Li, Zhenghong Tang, Xu Li, Jessie Winter Dec 2013

Drainage Structure Datasets And Effects On Lidar-Derived Surface Flow Modeling, Ruopu Li, Zhenghong Tang, Xu Li, Jessie Winter

School of Natural Resources: Faculty Publications

With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR)-derived digital elevation models (DEMs) have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing …


Wind Turbine Controls For Farm And Offshore Operation, Zhongzhou Yang Dec 2013

Wind Turbine Controls For Farm And Offshore Operation, Zhongzhou Yang

Theses and Dissertations

Development of advanced control techniques is a critical measure for reducing the cost of energy for wind power generation, in terms of both enhancing energy capture and reducing fatigue load. There are two remarkable trends for wind energy. First, more and more large wind farms are developed in order to reduce the unit-power cost in installation, operation, maintenance and transmission. Second, offshore wind energy has received significant attention when the scarcity of land resource has appeared to be a major bottleneck for next level of wind penetration, especially for Europe and Asia. This dissertation study investigates on several wind turbine …


Assessing The Impact Of Chlorine Residual On Trihalomethane And Haloacetonitrile Formation Under Chlorination And Chloramination Disinfection Regimes, Thien Duc Do Dec 2013

Assessing The Impact Of Chlorine Residual On Trihalomethane And Haloacetonitrile Formation Under Chlorination And Chloramination Disinfection Regimes, Thien Duc Do

Graduate Theses and Dissertations

A disinfection byproduct (DBP) formation potential (FP) test can be used to indirectly measure the concentration of DBP precursors in natural waters, permitting assessment of various DBP-related treatment processes and control strategies. While these tests require a 7-day chlorine residual (CR) between 3-5 mg L-1 as Cl2, it is not well known if this recommended residual corresponds to the true DBPFP (i.e., the maximum concentrations) for trihalomethanes (THMs) and haloacetonitriles (HANs). In this study, THMs and HANs were quantified as a function of CR under three common disinfection regimes: (1) free chlorine at pH 7.0 (FC7), (2) …


An Experimental And Computational Evaluation Of The Importance Of Molecular Diffusion In Gas Gravity Currents, Jeremy Jac Herman Dec 2013

An Experimental And Computational Evaluation Of The Importance Of Molecular Diffusion In Gas Gravity Currents, Jeremy Jac Herman

Graduate Theses and Dissertations

The accidental release of hazardous, denser-than-air gases during their transport or manufacture is a vital area of study for process safety researchers. This project examines the importance of molecular diffusion on the developing concentration field of a gas gravity current released into a calm environment. Questions which arose from the unexpectedly severe explosion in 2005 at Buncefield, England were of particular interest. The accidental overfilling of a large tank with gasoline on a completely calm morning led to a massive open air explosion. Forensic evidence showed that at the time of ignition, a vapor cloud, most of which now appears …


Sediment Microbial Fuel Cell As Sustainable Power Resource, Ananta Kothapalli Dec 2013

Sediment Microbial Fuel Cell As Sustainable Power Resource, Ananta Kothapalli

Theses and Dissertations

This research demonstrates that Ceratophyllum demersum a root less non vascular aquatic plant has negatively affected the power generation from a Sediment Microbial Fuel cell (SMFC). In SMFC the reduced organic matter in the sediment in water produces electrons, which reduces oxygen. Whereas in Plant SMFC continuous supply of organic matter to the anode is done by rhizodeposition (root exudates). Six SMFCs were run for more than 3 months to see the effect of plants, pH and temperature on power generation. Out of six only two SMFC showed stable data. The maximum power density 18 ± 1mW/m3 was generated from …


Evaluation Of Alternative Project Delivery Methods In Water And Wastewater Projects, Ruiko Maharjan Dec 2013

Evaluation Of Alternative Project Delivery Methods In Water And Wastewater Projects, Ruiko Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States (U.S.) is facing significant challenges in addressing aging water infrastructure. Most of the drinking water infrastructure is reaching the end of their useful lives. The American Water Works Association (AWWA) estimated that it will cost about $1 trillion to repair or replace drinking water pipes. Over the next 20 years, it will cost about $298 billion to fix or expand pipes of the nation's wastewater and storm-water systems (AWWA, 2012). Owners, engineers, and contractors are using Alternative Project Delivery (APD) methods - e.g., Design-Build Construction Management-at-Risk Construction Management/General Contractor- to build water and wastewater projects in order …


Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor, Jeremiah Boles Dec 2013

Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor, Jeremiah Boles

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to analyze the theoretical criticality of a spherical uranium-hexafluoride reactor with a transient, pulsed shockwave emanating from the center of the sphere in an outward-radial direction. This novel nuclear reactor design, based upon pulsed fission in a spherical enclosure is proposed for possible use in direct energy conversion, where the energy from fission products is captured through the use of electrostatic fields or through induction. An analysis of the dynamic behavior of the shockwave in this reactor is the subject of this thesis. As a shockwave travels through a fluid medium, the characteristics of …


A Case Study Of Zero Energy Home Built For Solar Decathlon Competition 2013, Sanjib Mulepati Dec 2013

A Case Study Of Zero Energy Home Built For Solar Decathlon Competition 2013, Sanjib Mulepati

UNLV Theses, Dissertations, Professional Papers, and Capstones

Energy consumption in residential homes has been a subject of research related to sustainability. Reduction in the consumption of energy is a goal of sustainable construction. The Department of Energy (DOE) started a Solar Decathlon competition in 2002 in which the students from different universities around the globe build an energy efficient and affordable home suitable for their climate and location. The main goal of this competition is to select the best home that is designed and built in a sustainable way. In this study, the home designed and constructed for participation in the competition by the students at University …


Improving Global Impact: How The Integration Of Remotely Reporting Sensors In Water Projects May Demonstrate And Enhance Positive Change, Evan A. Thomas Dec 2013

Improving Global Impact: How The Integration Of Remotely Reporting Sensors In Water Projects May Demonstrate And Enhance Positive Change, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

This article argues that improved feedback on the actual impact of development programs may ensure the success of poverty reduction interventions such as water filters, water pumps, latrines, and cookstoves.


Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi Nov 2013

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …


Zakład Termicznego Przekształcania Odpadów Komunalnych W Krakowie – Założenia Projektowe I Stan Realizacji Budowy, Mateusz Rzeszutek, Robert Oleniacz Nov 2013

Zakład Termicznego Przekształcania Odpadów Komunalnych W Krakowie – Założenia Projektowe I Stan Realizacji Budowy, Mateusz Rzeszutek, Robert Oleniacz

Robert Oleniacz

The aim of this paper is to discuss the design assumptions and to determine the current status of the construction of the Municipal Solid Waste Thermal Treatment Plant (ZTPOK) in Krakow with a capacity of 220 thousand tons per year. This plant, planned to be built by the end of 2015 years, will be an important element of municipal waste management system in the area of the Municipality of Krakow. ZTPOK in Krakow will consist of the following installations: two lines of municipal solid waste incinerators based on moving grate technology, an installation of chemical solidification and stabilization of fly …


The Cost Of Green Infrastructure: Worth The Investment?, Martha Sheils Nov 2013

The Cost Of Green Infrastructure: Worth The Investment?, Martha Sheils

Green Infrastructure

Is GI worth the investment?

• LID techniques often lead to cost savings when we look at WHOLE PROJECT COSTS

• Natural Infrastructure investments for flood control, drinking water protection and wildlife habitat can yield SIGNIFICANT AVOIDED COSTS and additional co-benefits to communitites


Assessing The Performance Of A Northern Gulf Of Mexico Tidal Model Using Satellite Imagery, Stephen C. Medeiros, Scott C. Hagen, Naira Chaouch, Jesse Feyen, Marouane Temimi, John F. Weishampel, Yuji Funakoshi, Reza Khanbilvardi Nov 2013

Assessing The Performance Of A Northern Gulf Of Mexico Tidal Model Using Satellite Imagery, Stephen C. Medeiros, Scott C. Hagen, Naira Chaouch, Jesse Feyen, Marouane Temimi, John F. Weishampel, Yuji Funakoshi, Reza Khanbilvardi

Publications and Research

Tidal harmonic analysis simulations along with simulations spanning four specific historical time periods in 2003 and 2004 were conducted to test the performance of a northern Gulf of Mexico tidal model. A recently developed method for detecting inundated areas based on integrated remotely sensed data (i.e., Radarsat-1, aerial imagery, LiDAR, Landsat 7 ETM+) was applied to assess the performance of the tidal model. The analysis demonstrates the applicability of the method and its agreement with traditional performance assessment techniques such as harmonic resynthesis and water level time series analysis. Based on the flooded/non-flooded coastal areas estimated by the integrated remotely …


Global Change Factors On Ecosystem Invasibility, Raj Lal, Jeffrey Dukes, Michael J. Schuster, Nick G. Smith Oct 2013

Global Change Factors On Ecosystem Invasibility, Raj Lal, Jeffrey Dukes, Michael J. Schuster, Nick G. Smith

The Summer Undergraduate Research Fellowship (SURF) Symposium

Current climate and human-induced changes are projected to alter many regimes of ecosystem functioning. It is projected that invasive species, nonnative species that can be of great detriment to an ecosystem, will benefit under these conditions. The Prairie Invasion and Climate Experiment (PRICLE) studies the effects of two global change factors – N addition and altered precipitation – on invasive species success and the traits that are selected for in a mixed-grass prairie ecosystem. PRICLE is a two by two factorial design over three replications in a restored mixed-grass prairie ecosystem. The major findings from the community traits examination of …


Archaeological Remote Sensing: Exploring The Past From Space, Kel Markert Oct 2013

Archaeological Remote Sensing: Exploring The Past From Space, Kel Markert

Von Braun Symposium Student Posters

No abstract provided.


Ambient: Affordable Microsatellite Based Internet Access And Environmental Monitoring, Tyler Maddox Oct 2013

Ambient: Affordable Microsatellite Based Internet Access And Environmental Monitoring, Tyler Maddox

Von Braun Symposium Student Posters

No abstract provided.


Evaluation Of Phase Change Materials For Cooling In A Super-Insulated Passive House, Jeffrey Stephen Lauck Oct 2013

Evaluation Of Phase Change Materials For Cooling In A Super-Insulated Passive House, Jeffrey Stephen Lauck

Dissertations and Theses

Due to factors such as rising energy costs, diminishing resources, and climate change, the demand for high performance buildings is on the rise. As a result, several new building standards have emerged including the Passive House Standard, a rigorous energy-use standard based on a super-insulated and very tightly sealed building envelope. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference, annual heating energy is less than or equal to 15kWh/m2, and total annual source energy is less than or equal to 120 kWh/m2. A common …


Sweet (Small Wind Energy Estimation Tool), Thomas Woolmington, Keith Sunderland Oct 2013

Sweet (Small Wind Energy Estimation Tool), Thomas Woolmington, Keith Sunderland

Other resources

Description:

Generic Wind Energy Estimation Model incorporating Turbulence Intensity.

Requirements:

Manufacturer specific wind turbine characteristic

Mean wind speed at a specific height

Site conditions in terms of TI and Surface Roughness

Disclaimer:

This model has been designed as an estimation tool for estimating the wind power yield of a custom turbine for an idealised set of site conditions for a given year.

While the assumptions that are made in this estimation tool are mathematically plausible they should not in any way be interpreted as an alternative to a real world site assessment.

A list of assumptions to which the model …


Direct And Indirect Greenhouse Gas Emissions From Biomass Storage: Implications For Life Cycle Assessment Of Biofuels, Isaac Robert Emery Oct 2013

Direct And Indirect Greenhouse Gas Emissions From Biomass Storage: Implications For Life Cycle Assessment Of Biofuels, Isaac Robert Emery

Open Access Dissertations

Ethanol and other biofuels from cellulosic feedstocks are currently the most promising candidates to replace a large fraction of gasoline consumption in the United States and reduce greenhouse gas emissions. Gaps in current approaches to estimating the net greenhouse gas emissions from second-generation biofuels may lead to underestimation of the carbon intensity of these fuels. Current life cycle assessment models of biofuels do not sufficiently account for biomass losses and emissions associated with the harvest and storage of biomass feedstocks, which can require additional fuel and materials use on the farm as well as reducing the effective yield of a …


Electric Machine Differential For Vehicle Traction Control And Stability Control, Sandun Shivantha Kuruppu Oct 2013

Electric Machine Differential For Vehicle Traction Control And Stability Control, Sandun Shivantha Kuruppu

Open Access Dissertations

Evolving requirements in energy efficiency and tightening regulations for reliable electric drivetrains drive the advancement of the hybrid electric (HEV) and full electric vehicle (EV) technology. Different configurations of EV and HEV architectures are evaluated for their performance. The future technology is trending towards utilizing distinctive properties in electric machines to not only to improve efficiency but also to realize advanced road adhesion controls and vehicle stability controls. Electric machine differential (EMD) is such a concept under current investigation for applications in the near future. Reliability of a power train is critical. Therefore, sophisticated fault detection schemes are essential in …


Redefining The Operation And Design Considerations Of Organic Solar Cells: Role Of Morphology And Defect States, Biswajit Ray Oct 2013

Redefining The Operation And Design Considerations Of Organic Solar Cells: Role Of Morphology And Defect States, Biswajit Ray

Open Access Dissertations

Organic photovoltaic (OPV) technology is currently a topic of great interest for potentially low cost solar energy conversion and possibility of many novel PV applications (e.g., building-integrated PV, portable solar cells). Successful commercialization of this technology, however, will require significant improvement in efficiency and lifetime. In the last few years, innovation in novel polymer synthesis has raised the efficiency of OPV above 10%, at par with a-Si and earth-abundant solar cells. Further improvement in performance relies on breakthroughs in device design, which requires profound understanding of the physics of device operation. A major challenge in the design of the state …


Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith Oct 2013

Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith

Open Access Dissertations

In the past few years, stakeholders in the transportation industry have been concerned with sustainability. However, transportation decision makers have had difficulty incorporating sustainability into transportation infrastructure decisions. This is mainly attributed to the vagueness of the term. Incorporating sustainability into transportation decision making has been a desire put forth by engineers for that past 10 years. However, with no apparent method of defining sustainability, designers and decision makers have not been able to fulfill this desire.

This investigation attempts to define sustainability in a comprehensive and quantitative manner. The research proposes a new methodology that relies on the objective …


Solar Cell Temperature Dependent Efficiency And Very High Temperature Efficiency Limits, John Robert Wilcox Oct 2013

Solar Cell Temperature Dependent Efficiency And Very High Temperature Efficiency Limits, John Robert Wilcox

Open Access Dissertations

Clean renewable solar energy is and will continue to be a critically important source of electrical energy. Solar energy has the potential of meeting all of the world's energy needs, and has seen substantial growth in recent years. Solar cells can convert sun light directly into electrical energy, and much progress has been made in making them less expensive and more efficient. Solar cells are often characterized and modeled at 25 °C, which is significantly lower than their peak operating temperature. In some thermal concentrating systems, solar cells operate above 300 °C. Since increasing the temperature drastically affects the terminal …


Energy Systems Analysis For A Solar Economy, Dharik Sanchan Mallapragada Oct 2013

Energy Systems Analysis For A Solar Economy, Dharik Sanchan Mallapragada

Open Access Dissertations

The use of solar energy for human needs faces challenges owing to its relatively low energy intensity and intermittent availability, coupled with the constrained availability of renewable carbon and land resources. This study uses systems analysis tools to identify carbon and energy efficient transformations of solar energy for different purposes, including transportation fuels and grid-scale energy storage. These efforts have been complemented with a feasibility analysis of existing fossil-energy and other hybrid pathways.

In an era of limited fossil resources, liquid fuels from sustainably available (SA) biomass could meet the energy needs of the transportation sector. We present a method …


An Experimental Investigation Of Wind Turbine Aerodynamic Interaction, Brandon Lee Ennis Oct 2013

An Experimental Investigation Of Wind Turbine Aerodynamic Interaction, Brandon Lee Ennis

Open Access Dissertations

Wind turbines have become a viable component in the overall energy makeup of the United States due to improved economics where energy prices have risen and production costs dropped. For a fixed cost, the effectiveness of a wind turbine financially is highly related to its performance. Considering the size of current wind farms, a minor performance improvement will result in large additional sums of revenue. A problem that has received attention with wind farms is that while the fixed costs of the development do get spread out further to reduce the installed cost of each wind turbine, the wind turbines …


An Analysis Of The Impact Of Storage Temperature, Moisture Content & Duration Upon The Chemical Components & Bioprocessing Of Lignocellulosic Biomass, Arun Athmanathan Oct 2013

An Analysis Of The Impact Of Storage Temperature, Moisture Content & Duration Upon The Chemical Components & Bioprocessing Of Lignocellulosic Biomass, Arun Athmanathan

Open Access Dissertations

The successful utilization of lignocellulosic biomass as a feedstock for fuels and chemicals necessitates storage for 2-6 months. It is correspondingly important to understand the impact of storage parameters - moisture concentration, temperature and duration - on biomass quality.

As aerobic storage is the most viable large-scale solution, aerobic storage experiments were carried out with three projected bioenergy feedstocks - sweet sorghum (Sorghum bicolor) bagasse, corn (Zea mays) stover and switchgrass (Panicum virgatum). Stored samples of each were examined for dry matter loss and composition change to develop a material balance around carbohydrates and lignin.

A mean dry matter loss …


Technology Agnostic Analysis And Design For Improved Performance, Variability, And Reliability In Thin Film Photovoltaics, Sourabh Dongaonkar Oct 2013

Technology Agnostic Analysis And Design For Improved Performance, Variability, And Reliability In Thin Film Photovoltaics, Sourabh Dongaonkar

Open Access Dissertations

Thin film photovoltaics (TFPV) offer low cost alternatives to conventional crystalline Silicon (c-Si) PV, and can enable novel applications of PV technology. Their large scale adoption however, requires significant improvements in process yield, and operational reliability. In order to address these challenges, comprehensive understanding of factors affecting panel yield, and predictive models of performance reliability are needed. This has proved to be especially challenging for TFPV for two reasons in particular. First, TFPV technologies encompass a wide variety of materials, processes, and structures, which fragments the research effort. Moreover, the monolithic manufacturing of TFPV modules differs significantly from that of …


Traditional Boat Building: An Intersection Of Zanzibar’S Culture And Environment, Eric Levenson Oct 2013

Traditional Boat Building: An Intersection Of Zanzibar’S Culture And Environment, Eric Levenson

Independent Study Project (ISP) Collection

This study examined traditional boat building on Uzi Island as a manifestation of Zanzibar’s relationship of environment and culture. Information was gathered about traditional boat building practices, the resource use and management pertaining to boats, the cultural reliance on boats, and local views on environment and conservation. This information showed that the people of Uzi Island were dependent on the use of traditional boats to maintain their livelihood, however the tree types used for boat building are being over-harvested. This tension of culture and environment exposed the need for conservation of Zanzibar’s natural resources in a manner that does not …


Enhanced Adaptive Management: Integrating Decision Analysis, Scenario Analysis And Environmental Modeling For The Everglades, Matteo Convertino, Christy Foran, Jeffrey Keisler, Lynn Scarlett, Andrew Loschiavo, Greg Kiker, Igor Linkov Sep 2013

Enhanced Adaptive Management: Integrating Decision Analysis, Scenario Analysis And Environmental Modeling For The Everglades, Matteo Convertino, Christy Foran, Jeffrey Keisler, Lynn Scarlett, Andrew Loschiavo, Greg Kiker, Igor Linkov

Jeffrey Keisler

We propose to enhance existing adaptive management efforts with a decision-analytical approach that can
guide the initial selection of robust restoration alternative plans and inform the need to adjust these
alternatives in the course of action based on continuously acquired monitoring information and changing
stakeholder values. We demonstrate an application of enhanced adaptive management for a wetland
restoration case study inspired by the Florida Everglades restoration effort. We find that alternatives
designed to reconstruct the pre-drainage flow may have a positive ecological impact, but may also have high
operational costs and only marginally contribute to meeting other objectives such as …