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2018

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Articles 181 - 210 of 8945

Full-Text Articles in Engineering

Effect Of Curing Conditions On Mechanical Properties And Durability Of Concrete, Edgar Lazaro Salas-Borrero Dec 2018

Effect Of Curing Conditions On Mechanical Properties And Durability Of Concrete, Edgar Lazaro Salas-Borrero

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents the results for three different concrete mix designs with compression strengths of 4500 psi. The experiment was conducted in the Las Vegas area during the summer, from August 16th to October 12th, 2018, where temperatures and relative humidity was recorded daily, three times a day. In total, 135 concrete specimens (4” x 8”) were taken on site and were subjected to five different curing conditions.

For each concrete mix design, three concrete samples (4” x 8”) were taken and submitted for each curing condition, resulting in 45 cylinders for each concrete mix design. The same number of …


Calculation Of Access Charge For High Speed Rail Xpresswest Of Nevada, Sameeksha Sapkota Dec 2018

Calculation Of Access Charge For High Speed Rail Xpresswest Of Nevada, Sameeksha Sapkota

UNLV Theses, Dissertations, Professional Papers, and Capstones

XpressWest is a High Speed Rail (HSR) system that plans to connect Las Vegas with California at Palmdale. It will utilize the railway network of the California High Speed Rail (CAHSR) to connect Las Vegas with California destinations that include Los Angeles and San Francisco. For sharing the railway network of CAHSR, XpressWest will pay certain charge known as an access charge. The access charge is the fee paid by the train operator to the infrastructure owner for the addition of trains in a track. There are several access charge systems in the world. However, there is no study that …


Surface Resistivity For Concrete Quality Assurance, Stanley Tat Dec 2018

Surface Resistivity For Concrete Quality Assurance, Stanley Tat

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the effectiveness of SRT for concrete quality assurance and to evaluate the relationship between SRT and the three chloride ion ingress methods currently used by various State DOTs. Additionally, the influence of binder type and content, concrete age, and water-to cementitious materials ratio on the experimental results were also examined.

In this study, Type V Portland and three SCMs; namely fly ash, slag, and silica fume were used. Fine and coarse, aggregates were supplied by a local quarry. To evaluate the transport properties of the studied concretes, RMT, RCPT, and ACT were …


Monitoring The Impact Of Groundwater Pumping On Infrastructure Using Geographic Information System (Gis) And Persistent Scatterer Interferometry (Psi), Kirsten Deprekel, El Hachemi Bouali, Thomas Oommen Dec 2018

Monitoring The Impact Of Groundwater Pumping On Infrastructure Using Geographic Information System (Gis) And Persistent Scatterer Interferometry (Psi), Kirsten Deprekel, El Hachemi Bouali, Thomas Oommen

Department of Geological and Mining Engineering and Sciences Publications

Transportation infrastructure is critical for the advancement of society. Bridges are vital for an efficient transportation network. Bridges across the world undergo variable deformation/displacement due to the Earth’s dynamic processes. This displacement is caused by ground motion, which occurs from many natural and anthropogenic events. Events causing deformation include temperature fluctuation, subsidence, landslides, earthquakes, water/sea level variation, subsurface resource extraction, etc. Continual deformation may cause bridge failure, putting civilians at risk, if not managed properly. Monitoring bridge displacement, large and small, provides evidence of the state and health of the bridge. Traditionally, bridge monitoring has been executed through on-site surveys. …


Optimal Placement Of Distributed Energy Storage Systems In Distribution Networks Using Artificial Bee Colony Algorithm, Choton K. Das, Octavian Bass, Ganesh Kothapalli, Thair S. Mahmoud, Daryoush Habibi Dec 2018

Optimal Placement Of Distributed Energy Storage Systems In Distribution Networks Using Artificial Bee Colony Algorithm, Choton K. Das, Octavian Bass, Ganesh Kothapalli, Thair S. Mahmoud, Daryoush Habibi

Research outputs 2014 to 2021

The deployment of utility-scale energy storage systems (ESSs) can be a significant avenue for improving the performance of distribution networks. An optimally placed ESS can reduce power losses and line loading, mitigate peak network demand, improve voltage profile, and in some cases contribute to the network fault level diagnosis. This paper proposes a strategy for optimal placement of distributed ESSs in distribution networks to minimize voltage deviation, line loading, and power losses. The optimal placement of distributed ESSs is investigated in a medium voltage IEEE-33 bus distribution system, which is influenced by a high penetration of renewable (solar and wind) …


Analysis And Design Of Analog Front-End Circuitry For Avalanche Photodiodes (Apd) And Silicon Photo-Multipliers (Sipm) In Time-Of-Flight Applications, Vikas Vinayaka Dec 2018

Analysis And Design Of Analog Front-End Circuitry For Avalanche Photodiodes (Apd) And Silicon Photo-Multipliers (Sipm) In Time-Of-Flight Applications, Vikas Vinayaka

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports the analysis and design of analog front-end circuitry for reading out signals from avalanche photodiodes (APD) or silicon photomultiplier (SiPM) in time-of-flight (ToF) applications. An integrated circuit was designed using AMS SiGe 0.35 um BiCMOS process. The chip measured 2 mm x 2 mm (2000 umx2000 um). The chip mainly contains the following circuits: an APD with photoactive area measuring 24 umx24 um, an SiPM with 8x8 APDs with 236 k ohm quench resistors, a transimpedance amplifier (TIA), a comparator and a R-2R digital to analog converter (DAC). The TIA is based on the shunt-shunt feedback topology. …


Performance-Based Economical Seismic Design Of Multistory Reinforced Concrete Frame Buildings And Reliability Assessment, Chunyu Zhang Dec 2018

Performance-Based Economical Seismic Design Of Multistory Reinforced Concrete Frame Buildings And Reliability Assessment, Chunyu Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the next generation of seismic design methodology, performance-based seismic design (PBSD) method requires a structure satisfy multiple preselected performance levels under different hazard levels. Optimal PBSD methods provide different strategies to design the numerous variables, including strength, stiffness and ductility of each structural component. The overall goal of this study is to develop a new optimal PBSD method for multi-story RC moment frames. This method is capable of overcoming the deficiencies of existing optimal PBSD methods and can be implemented by the U.S. design practice. The proposed method minimizes construction cost and takes the limit of member plastic rotation …


A Distributed Real-Time Short-Term Solar Irradiation Forecasting Network For Photovoltaic Systems, Michael Adelbert Gacusan Dec 2018

A Distributed Real-Time Short-Term Solar Irradiation Forecasting Network For Photovoltaic Systems, Michael Adelbert Gacusan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar irradiation forecasting is essential for PV connected electrical grids to maintain reliability, stability, and effective matching of real-time demand to power distribution. This research paper develops and evaluates proposed forecasting methods using wireless sensor networks. Each node of the network is capable of monitoring illuminance data and communicate it through RF and/or WiFi. The nodes are calibrated with respect to irradiance data from an industry-standard pyranometer. Power consumption of each node type is also collected at different operating states. The proposed sensor network can estimate a cloud motion vector or a cloud shadow’s speed and direction from the data …


Fluid Structure Interaction Study Of The Obstructive Sleep Apnea And Surgical Treatment Using Suture-Patch Device On The Patient’S Tongue, Yang Liu Dec 2018

Fluid Structure Interaction Study Of The Obstructive Sleep Apnea And Surgical Treatment Using Suture-Patch Device On The Patient’S Tongue, Yang Liu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Up to 14% of the U.S. population is estimated to have obstructive sleep apnea (OSA) related to obesity, and there is increased incidence occurring worldwide. While treatment with continuous positive airway pressure (CPAP) resolves airway obstruction, patient compliance is relatively low. Alternative interventions are available to treat OSA patients; however, their outcomes have had variable results. For example, current technologies have demonstrated an inability to define and treat the specific anatomical site(s) causing the obstruction, resulting in suboptimal modifications of the airway and poor control of OSA.

In the current study, a three-dimensional (3-D) fluid-structure interaction (FSI) numerical simulation has …


Biodegradable And Biocompatible Silk Fibroin For Optical Applications, Corey Bryce Malinowski Dec 2018

Biodegradable And Biocompatible Silk Fibroin For Optical Applications, Corey Bryce Malinowski

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study presents nanopatterned silk fibroin films that were fabricated using soft lithography and nanoimprinting to replicate patterns from diffraction gratings. These film’s optics were analyzed based on their light scattering potential as well as their transmittance and transmission haze using a laser light, spectrometer, and UV-Vis spectrophotometer, respectively. The patterned fibroin films all displayed similar light scattering patterns to their master patterns with some transmission haze. When using the spectrometer to measure samples, those made without any nanostructure displayed transmission of 90% and over, while those with patterns depended on the structure used. The denser a structure, like the …


Design And Preliminary Evaluation Of A Supercritical Carbon Dioxide Brayton Cycle For Solar Dish Concentrator Clean Energy Production, Danielle Nobles-Lookingbill Dec 2018

Design And Preliminary Evaluation Of A Supercritical Carbon Dioxide Brayton Cycle For Solar Dish Concentrator Clean Energy Production, Danielle Nobles-Lookingbill

UNLV Theses, Dissertations, Professional Papers, and Capstones

As we move toward energy independence and more ambitious clean energy goals, solar energy research must push the efficiency limits of traditional energy generation systems. Increases in efficiency can be achieved by increasing the hot temperature of the power cycle. Recent research demonstrates the potential for increased efficiency and a vastly smaller component size when supercritical carbon dioxide Brayton power cycles are used. Concentrated solar and nuclear heat sources are capable of achieving the high working fluid temperatures needed for significant efficiency gains. This NSF EPSCoR funded, experimental research system is designed to exploit the uniquely immense solar irradiance of …


Design And Analysis Of First And Second Order K-Delta-1-Sigma Modulators In Multiple Fabrication Processes, Shada Sharif Dec 2018

Design And Analysis Of First And Second Order K-Delta-1-Sigma Modulators In Multiple Fabrication Processes, Shada Sharif

UNLV Theses, Dissertations, Professional Papers, and Capstones

Analog to digital converters (ADC) are an important category of electronic circuits that are required in order to convert real-world analog signals into the digital domain. One of the main trade-offs in ADC design is between data conversion speed and resolution. Delta Sigma ADCs are commonly used for high precision data conversion of low bandwidth signals such as those found in audio, industrial and biomedical applications. A major disadvantage of traditional Delta Sigma ADC architectures is that they have limited signal bandwidth and are not suited for high speed applications such as communication systems. The continuous time K-Delta-1-Sigma (KD1S) modulator …


Variable Transition Time Inverters In A Digital Delay Line With Analog Storage For Processing Fast Signals And Pulses, James Kenton Mellott Dec 2018

Variable Transition Time Inverters In A Digital Delay Line With Analog Storage For Processing Fast Signals And Pulses, James Kenton Mellott

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the electronics industry moves forward there is an increasing need to process information faster and more accurately. High speed signals are used in scientific instrumentation, range finding devices, radar applications, and electro-optical interfaces. High-speed state of the art analog-to-digital converters are required to process these signals in real time. High frequency signals or very fast pulses are not able to be processed accurately due to either Nyquist-rate limitations or practical power consumption limits. For applications where signals are transient in nature and design size and power consumption are major factors, the proposed Variable Fast Transient Digitizer (VFTD) will be …


High Speed Fast Transient Digitizer Design And Simulation, Eric Clark Monahan Dec 2018

High Speed Fast Transient Digitizer Design And Simulation, Eric Clark Monahan

UNLV Theses, Dissertations, Professional Papers, and Capstones

In microelectronics, analog-to-digital converters (ADCs) are used as interfaces to convert analog inputs into discrete time or digital values that can be read via microcontrollers. As speed requirements and processing times in electronics continue to increase, high speed ADCs are increasingly critical components in the design of application-specific integrated circuits (ASICs). However, high speed ADCs introduce quantization error and are inefficient relative to size, cost, and power dissipation when compared to a High Speed Fast Transient Digitizer (HSFTD).

This thesis presents the design, layout, and simulation of a HSFTD designed to sample, in time at a fast rate, a high-speed …


Nanopower Analog Frontends For Cyber-Physical Systems, Kenji Aono Dec 2018

Nanopower Analog Frontends For Cyber-Physical Systems, Kenji Aono

McKelvey School of Engineering Graduate Student Theses & Dissertations

In a world that is increasingly dominated by advances made in digital systems, this work will explore the exploiting of naturally occurring physical phenomena to pave the way towards a self-powered sensor for Cyber-Physical Systems (CPS). In general, a sensor frontend can be broken up into a handful of basic stages: transduction, filtering, energy conversion, measurement, and interfacing. One analog artifact that was investigated for filtering was the physical phenomenon of hysteresis induced in current-mode biquads driven near or at their saturation limit. Known as jump resonance, this analog construct facilitates a higher quality factor to be brought about without …


Biosensing By “Growing” Antennas And Error-Correcting Codes, Mingquan Yuan Dec 2018

Biosensing By “Growing” Antennas And Error-Correcting Codes, Mingquan Yuan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Food-borne disease outbreaks not only cause numerous fatalities every year but also contribute to significant economic losses. While end-to-end supply chain monitoring can be one of the keys to preventing these outbreaks, screening every food product in the supply chain is not feasible considering the sheer volume and prohibitive test costs. Fortunately, two converging economic trends promise to make this end-to-end supply chain monitoring possible. The first trend is that passive radio-frequency identification (RFID) tags and quick response (QR) codes are now widely accepted for food packaging. The second trend is that smartphones are now equipped with the capability to …


Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger Dec 2018

Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger

UNLV Theses, Dissertations, Professional Papers, and Capstones

X-ray induced damage is generally considered a nuisance, but in the field of Useful Hard X-ray Photochemistry we harness the highly ionizing and penetrating properties of hard X-rays (> 7 keV) to initiate novel photochemical decomposition and synthesis at ambient and extreme conditions. Preliminary experiments suggest that the energy of irradiating photons and the sample pressure play roles in determining the nature of X-ray induced damage. Here, we present the X-ray energy dependence of damage induced in strontium oxalate, strontium nitrate, and barium nitrate, as well as the pressure dependence of X-ray induced damage of strontium oxalate. Our results indicate …


Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry Dec 2018

Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

This Thesis is concerned with the design, layout, and testing of avalanche photodiodes (APDs). APDs are a type of photodetector and, thus, convert light signals into electrical signals (current or voltage). APDs can be fabricated using silicon (Si). In this Thesis, however, three integrated circuit (IC) chips containing various silicon-germanium (SiGe) APDs with different sizes, structures, and geometries were designed, laid out, and fabricated using the Austriamicrosystems (AMS) 0.35μm SiGe BiCMOS (S35) process. This was done in order to compare SiGe APDs to Si only APDs and investigate the hypothesis that SiGe APDs are capable of detecting longer wavelengths than …


Comparing Beijing's And Tokyo's Population Growths, Ernest M. Oleksy Dec 2018

Comparing Beijing's And Tokyo's Population Growths, Ernest M. Oleksy

The Downtown Review: An Interdisciplinary Journal Written and Peer-Reviewed by Mandel Honors College Students at Cleveland State University

The growth of the human population has led to the formation of largely populated agglomerations known as megacities. Although megacities can be found on multiple continents, Asia’s collection displays how megacities can develop in their own directions. Japan’s megacity of Tokyo, like other Japanese megacities, has adopted a western approach. China’s Beijing, on the other hand, continues to embrace its eastern roots. These megacities may differ in their ideologies, but they share in experiencing similar phenomena. One of these phenomena is population growth.


The Theory Of Relativity And Applications: A Simple Introduction, Ellen Rea Dec 2018

The Theory Of Relativity And Applications: A Simple Introduction, Ellen Rea

The Downtown Review: An Interdisciplinary Journal Written and Peer-Reviewed by Mandel Honors College Students at Cleveland State University

This paper will provide a brief overview of the theory of relativity by looking at its two parts: special relativity and general relativity. It will omit most of the complex mathematics involved in order to focus on providing a more conceptual understanding. However, some simplified equations will be introduced to illustrate various aspects of the theory. Some of the experiments and scientific observations that support the theory as well as some of the scientific advances that emerged from the theory will also be discussed. Following the overview of the theory of relativity will be some of its applications in past …


An Examination Of The Death Penalty, Alexandra N. Kremer Dec 2018

An Examination Of The Death Penalty, Alexandra N. Kremer

The Downtown Review: An Interdisciplinary Journal Written and Peer-Reviewed by Mandel Honors College Students at Cleveland State University

The death penalty, or capital punishment, is the use of execution through hanging, beheading, drowning, gas chambers, lethal injection, and electrocution among others in response to a crime. This has spurred much debate on whether it should be used for reasons such as ethics, revenge, economics, effectiveness as a deterrent, and constitutionality. Capital punishment has roots that date back to the 18th century B.C., but, as of 2016, has been abolished in law or practice by more than two thirds of the world’s countries and several states within the United States. Here, the arguments for and against the death …


Creating Holistic Engineers To Solve The Grand Challenges Of The Future, Una Beagon Dec 2018

Creating Holistic Engineers To Solve The Grand Challenges Of The Future, Una Beagon

Articles

Una Beagon writes that continued growth in construction depends on third level Institutions securing a talent pipeline of Civil & Structural Engineers with suitable skill sets to bring about, maintain and operate large multidisciplinary projects.


Walker, Dorian (Fa 1240), Manuscripts & Folklife Archives Dec 2018

Walker, Dorian (Fa 1240), Manuscripts & Folklife Archives

Folklife Archives Finding Aids

Finding aid only for Folklife Archives Project 1240. Collection of oral history interviews with railroad employees, locals, and historians recorded on Betacam and Betacam SP for Dorian Walker’s 1995 film Beauty of the Southland. Portions of the interviews were also used for a 2010 miniseries, All Aboard.


Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami Dec 2018

Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami

Theses & Dissertations

Past studies have shown that the success of total joint replacements depends on the biocompatibility of orthopaedic materials, which can be improved by modifying the implant surface. However, the exact roles of these modifications and their effective mechanisms are poorly understood. The objective of this study was to develop and evaluate a model system to investigate the impact of nano-structured surfaces, produced by the ion beam-assisted deposition (IBAD) technique, on biomarkers of osteointegration using an in vitro model. The IBAD technique was employed to deposit zirconium oxide (ZrO2), Titanium oxide (TiO2), and Titanium (Ti) nano-films on …


Development Of The University Of New Mexico Spectrometer For High-Resolution Fission Product Yield Data, Richard Emery Blakeley Dec 2018

Development Of The University Of New Mexico Spectrometer For High-Resolution Fission Product Yield Data, Richard Emery Blakeley

Nuclear Engineering ETDs

Well-defined fission product yield data has been of increasing interest in various applications within the nuclear industry. With this need in mind, a fission fragment mass spectroscopy system was designed and developed at the University of New Mexico in collaboration with the Los Alamos National Laboratories with a stated goal of attaining a mass resolution of ≤ 1 % (FWHM/centroid) for light fragments and near 1 % for heavy fragments. The mass spectrometer utilized in this work consists of a transmission time-of-flight detection system to measure fission product velocity and an axial ionization chamber to measure the fission product energy, …


An Engineered Fit-For-Purpose Polymer Nanocomposite Seal Repair Material For Wellbores, Moneeb Genedy Dec 2018

An Engineered Fit-For-Purpose Polymer Nanocomposite Seal Repair Material For Wellbores, Moneeb Genedy

Civil Engineering ETDs

Seal integrity of wellbores has become of significant interest due to repeated leakage and spill incidents occurring worldwide that jeopardize both human health and the environment in addition to causing significant economic burden. This is attributed to the fact that wellbores intersecting geographical formations contain potential leakage pathways. The cement-steel and cement-rock formation interfaces are recognized as two critical leakage pathways.

A seal repair material that has good bond strength with both steel and rock formations in addition to the ability to completely fill thin microcracks is needed to restore the seal integrity of wellbores. In this research, engineered polymer …


Integration Of A Commercial Smart Thermostat To The Aggregated Load Control Simulation Framework, Jee Won Choi Dec 2018

Integration Of A Commercial Smart Thermostat To The Aggregated Load Control Simulation Framework, Jee Won Choi

Mechanical Engineering ETDs

As part of an effort to achieve a better balance between the power demand and supply, load (demand) control simulation framework is previously developed. In the framework, HVAC load is used as a control resource, driven by the thermostat logic modeled within the framework. However, it has not been proved, whether a com- mercial thermostat is able to perform modeled thermostat’s features. Therefore, it is desired to integrate a commercial thermostat to the framework, to verify its capabil- ity of participating and performing the Demand Response (DR) scheme developed. A ‘Nest Learning Thermostat’ is selected as a commercial thermostat. Nest …


Multi-Layer Shotcrete Design For Tunnel Construction, Bruno Mattle, Wolfgang Summerer, Sebastian Höser, Vladimír Bartoš Dec 2018

Multi-Layer Shotcrete Design For Tunnel Construction, Bruno Mattle, Wolfgang Summerer, Sebastian Höser, Vladimír Bartoš

Shotcrete for Underground Support XIII: New Developments in Rock Engineering, Tunneling, Underground Space and Deep Excavation

No abstract provided.


Flow Analysis Through Collectorwell Laterals: A Case Study From Sonoma County Water Agency, California, Matteo D'Alessio, John Lucio, Ernest Williams, Donald Seymour, Jay Jasperse, Chittaranjan Ray Dec 2018

Flow Analysis Through Collectorwell Laterals: A Case Study From Sonoma County Water Agency, California, Matteo D'Alessio, John Lucio, Ernest Williams, Donald Seymour, Jay Jasperse, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction …


Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra Dec 2018

Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra

Physiology Faculty Publications

Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and …