Engineering Commons^™

Seismic Characterization Of Select Engineered Nanoparticles In Essentially Saturated Glass Beads, Mohamed Nihad Rajabdeen

UNLV Theses, Dissertations, Professional Papers, and Capstones

A laboratory testing apparatus was developed for the study of seismic body wave propagation through nanoparticles dispersed in pore fluid that is essentially saturating glass beads. First, the responses of water-saturated glass bead specimens were studied to establish baseline signatures. Then the seismic responses in the presence of engineered nanoparticles of various concentrations dispersed in the pore fluid of the specimen chamber were studied to observe variances from baseline.

The testing apparatus incorporates piezoceramic bender elements to actuate and receive seismic body waves through a cylindrical column filled with glass beads and back-saturated at ambient pressure with liquid. The system …

Traffic Safety: Modeling, Analysis And Visualization, Puneet Lakhanpal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traffic Safety has always been one of the major issues of concern in United States. Every year, stringent efforts are made by the national agencies and safety offices to uplift the traffic safety standards and build systems which can guide them in policy making, reducing crashes and routing the financial resources in an optimal direction. This thesis studies the traffic safety from three different angles: modeling, analysis and visualization. In the beginning, these three components are explored in the domain of Injury Severity. Later on, the focus is shifted towards the Traffic Safety related to Safety Belts. Factors and models …

Accurate Circuit Model For Predicting The Performance Of Lead-Acid Agm Batteries, Wenxin Peng

UNLV Theses, Dissertations, Professional Papers, and Capstones

Energy storage technologies are becoming of great importance in many modern electrical systems. In particular, electrochemical batteries are rapidly gaining wide-spread application in transportation systems as well as in the electric utility sector, where they provide a means to convert non-dispatchable renewable resources into dispatchable generation sources. Hence, accurate battery models are needed during the design stage of such systems to forecast future performance.

A variety of models with a varying degree of complexity and accuracy currently exist that predict battery behavior. In the proposed paper, an existing battery model is modified to account for some battery irregularities while maintaining …

Determination Of The Electric Field Intensity And Space Charge Density Versus Height Prior To Triggered Lightning, Christopher J. Biagi, Martin A. Uman, Jay Gopalakrishnan, J. D. Hill, Vladimir A. Rakov, T. Ngin, Douglas M. Jordan

Mathematics and Statistics Faculty Publications and Presentations

We infer the vertical profiles of space charge density and electric field intensity above ground by comparing modeling and measurements of the ground-level electric field changes caused by elevating grounded lightning-triggering wires. The ground-level electric fields at distances of 60 m and 350 m were measured during six wire launches that resulted in triggered lightning. The wires were launched when ground-level electric fields ranged from 3.2 to 7.6 kV m⁻¹ and the triggering heights ranged from 123 to 304 m. From wire launch time to lightning initiation time, the ground-level electric field reduction at 60 m ranged from 2.2 …

Variability Of Strain And Strain Rate In The Human Tibial Diaphysis During Walking, Tyler Franklin Rooks

Boise State University Theses and Dissertations

With the prevalence of stress fractures in the military and athletes of all levels, research into the pathology of this injury has taken flight in recent years. One area of research has focused on the role bone strain, which is known to be a factor in bone remodeling, has on stress fracture development. It has been difficult to perform studies in this area of research due to the invasiveness of in vivo measurements of the bone strain. Recently, a methodology for approximating the bone strain using a computational model was proposed by Al Nazer et al. (Al Nazer et al., …

Wideband Dual-Frequency Dual-Polarized Dipole-Like Antenna, Xiulong Bao, Max Ammann

Articles

A wideband dual-frequency dual-polarized printed antenna is proposed for LTE, WLAN, and UWB systems. The dual-band antenna provides wide impedance bandwidths of 74% with respect to the center frequency of 2.725 GHz, and 39% with respect to the center frequency of 7.15 GHz. An open slot in the ground plane between the feed arms provides an orthogonal path to realize an embedded circularly polarized band at 2.35 GHz with an axial-ratio bandwidth of 16%. Dual-band characteristics are achieved by an asymmetrical dipole-like element and the coupling configuration between the T-shaped feed line and the wide ground-plane slot.

Monofilar Spiral Slot Antenna For Dual-Frequency Dual-Sense Circular Polarization, Xiulong Bao, Max Ammann

Articles

A dual-band antenna with right-hand circular polarization for the first frequency and the counter polarization at the second frequency is realized with compact printed spiral slots. The coupled spiral slots are fed by a 50 Ω microstrip line. Dual-sense circularly-polarized performance is achieved by realizing oppositely-directed current rotation for the two frequency bands. A parametric study shows that the additional slot significantly improves the bandwidth for both frequency bands. Measured results show that the fractional impedance bandwidth is greater than 18% for both bands. The 3 dB axial-ratio bandwidths are 4.5% and 3.5% for the RHCP and LHCP bands, respectively.

Applying Inventory Control Practices Within The Sisters Of Mercy Health Care Supply Chain, Server Apras

Graduate Theses and Dissertations

This research lays a foundation for the better understanding of the application and acceptance of more advanced inventory control practices within the health care supply chain. The demand characteristics and optimal control policies for pharmaceutical items within a multi-echelon provider network are examined within the framework of a case study. Demand forecasting algorithms were applied to forecast demand for inventory control procedures. A spreadsheet-based inventory planning tool was used to minimize the inventory holding and ordering costs subject to fill rate constraints. The costs of inventory control models are compared to the current ordering and inventory control strategies to document …

Recycling Waste Latex Paint In Overlays, Rigid Pavements, And Pervious Concrete, Oscar Inez Quiroz

UNLV Theses, Dissertations, Professional Papers, and Capstones

With over 16 million gallons of latex paint (WLP) being disposed every year it is the largest by volume, liquid hazardous waste in the United States. WLP is difficult to recycle and hazardous to the environment due to the volatile organic compounds it contains. Several methods exist for disposing WLP including paint swaps, combustion, drying and discarding in a landfill, and by placing pigments in cement. Many communities are moving to dispose WLP by drying and placing in a landfill due to the reduced cost. However, this is the least preferred technique for the environment because it creates a need …

Interview With Adam Boesel, Green Micro Gym, 2011 (Audio), Adam Boesel

All Sustainability History Project Oral Histories

Interview of Adam Boesel by Teresa Celestine at Green Micro Gym Portland, Oregon on July 29th, 2011.

The interview index is available for download.

Efficient, Accurate, And Non-Gaussian Error Propagation Through Nonlinear, Closed-Form, Analytical System Models, Travis V. Anderson

Theses and Dissertations

Uncertainty analysis is an important part of system design. The formula for error propagation through a system model that is most-often cited in literature is based on a first-order Taylor series. This formula makes several important assumptions and has several important limitations that are often ignored. This thesis explores these assumptions and addresses two of the major limitations. First, the results obtained from propagating error through nonlinear systems can be wrong by one or more orders of magnitude, due to the linearization inherent in a first-order Taylor series. This thesis presents a method for overcoming that inaccuracy that is capable …

Simulation Of Dna Extension In Nanochannels, Yanwei Wang, Douglas R. Tree, Kevin D. Dorfman

Faculty Publications

We have used a realistic model for double-stranded DNA and Monte Carlo simulations to compute the extension (mean span) of a DNA molecule confined in a nanochannel over the full range of confinement in a high ionic strength buffer. The simulation data for square nanochannels resolve the apparent contradiction between prior simulation studies and the predictions from Flory theory, demonstrating the existence of two transition regimes between weak confinement (the de Gennes regime) and strong confinement (the Odijk regime). The simulation data for rectangular nanochannels support the use of the geometric mean for mapping data obtained in rectangular channels onto …

Investigation Of Rfid Readability For License Plates In Static And Motion Testing, Srinivasan Venkatesan

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The most important function of RFID in vehicle tracking is to store information concerning tagged elements in order to improve the overall performance of movable asset management. There is a need to discover an RFID system for the tracking of vehicles, as existing vehicle tracking systems are undependable. Experiments were performed with SIRIT, SAVI, and RF code RFID systems under differing conditions, attaching the tag to the license plate instead of the windshield. Different spacers were also tested to reduce the effect of metal surfaces on RFID signals.

Preliminary experiments were performed before stationary and motion testing in order to …

Development Of A Multiple Vehicle Collaborative Unmanned Aerial System, Lloyd B. Mize Iv

Theses and Dissertations

The purpose of this research was to design a multiple UAV system with collaborative operation. This project is built on work that has been done in the field of Unmanned Systems at VCU and is aimed at providing a starting point for research into collaborative control of multiple UAVs. The current GCS software was extended to include multiple vehicles per single controller via a new communication protocol. Many changes were made to the user interface to facilitate controlling multiple vehicles with a single operator. A second processor, called an MCS, was added to each vehicle to allow for greater flexibility …

Quantitative Analysis Of The Reaction Between Gliadin And Citric Acid Under Weak Acidic And Weak Alkaline Conditions, Wei Li

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Gliadin was reacted with citric acid under weak acidic and weak alkaline conditions in both wet and dry states and the reaction mechanism was studied. The low morphological stability in an aqueous environment and inferior mechanical properties have restricted the applications of plant proteins, although these materials possess a unique structure, biocompatibility and biodegradability. Carboxylic acids such as citric acid are inexpensive and nontoxic chemicals and are preferred for crosslinking proteins and cellulose to improve the desired properties of the materials.

In this study, gliadin was chosen as a model of plant proteins to react with citric acid. However, previous …

Performance Comparison Of Layered Composite Bimodal Fiber Mats With Unimodal Fiber Mats, Sukhada Sanjay Kulkarni

Theses and Dissertations

The study was conducted to evaluate and compare performance of unimodal and bimodal mats with approximately same mass. 10% and 18% Nylon 4, 6 polymer solution were used for electrospinning the fibers. A negative ion source was used to neutralize the surface charge. The fiber diameters were measured with SEM and were <500 nm thus incorporating the slip effect. Bimodal mats were prepared from different deposition modes. Optimal mode was selected on analyzing the performance factors. The bimodal mats were then compared with unimodal mats. For their performance the fiber mass for these mats was approximately the same. It was observed that the unimodal mats had higher efficiencies and higher pressure drop giving a lower FOM. Bimodal mats showed lower efficiencies and pressure drop compared to unimodal mats. However, the FOM for bimodal mats was approximately 200% higher than unimodal mats

Wireless Embedded Smart Cameras: Performance Analysis And Their Application To Fall Detection For Eldercare., Alvaro Pinto

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Wireless Embedded Smart Camera Networks has received a lot of attention from academia and industry because they are small in size and easy to deploy, and they offer a multitude of attractive applications. They can be used for embedded single unit applications, or can be networked for multi-camera applications.

We first analyze three different operation scenarios for a wireless vision sensor network wherein different levels of local processing is performed. A detailed quantitative comparison of three operation scenarios are presented in terms of energy consumption and latency. This quantitative analysis provides the motivation for performing high-level local processing and decision …

Fracture Analyses Of Aging Aircraft Structures And Human Aorta, Ananth Ram Mahanth Kasavajhala

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Understanding the behavior of fracture due to preliminary flaws in materials is essential to escalate the life and reliability of a structure. The present work is focused on investigating the influence of various structural parameters on the pre-crack growth stress state, initiation and propagation of flaws in two distinct fields of engineering that is, aging aircraft structural repair (aerospace) and the human aortic dissection (life sciences). Three dimensional finite element methodologies, coupled with linear elastic fracture mechanics (LEFM) formulation was utilized in both the cases.

A model of pre-cracked Al 7075 T6 plate was used to analyze pre- and post- …

Silk Fibroin-Based Scaffolds For Tissue Engineering Applications, Jennifer Mccool

Theses and Dissertations

This study focused on the comparison of the electrospun silk scaffolds to the electrospun silk fibroin gel scaffolds. Moreover, this study examined the differences in cross-linking effects of genipin and methanol as well as solvents on the mechanical properties and cell compatibility of the scaffolds. Silk scaffolds were electrospun from an aqueous solution or 1,1,1,3,3-hexafluoro-2-propanol (HFIP) without genipin, immediately after 8 % (wt) genipin was added to the solution, and 18 hours after genipin blended with the solution. Uniaxial tensile testing determined that the silk scaffolds electrospun from water exhibit a higher modulus and peak stress than that of the …

Characterization Of Parallel Application Runtime Sensitivity On Multi-Core High Performance Computing Systems, Padma Priya Veeraraghavan

Purdue Polytechnic Masters Theses

A commonly seen behavior of parallel applications is that their runtime is influenced by network communication load. The way a parallel application is run in a network and the presence of other applications and processes in the network can contribute to a wide range of variations in the runtime. Therefore, in order to achieve consistent and optimal runtimes, it is important to understand and characterize the runtime sensitivity of parallel applications with respect to execution under the presence of network communication load.

In this research, runtime sensitivities for various parallel applications were studied by applying additional network communication load. In …

Miniature Mass Spectrometry: Rf Amplitude Control System Design, Matthew Allen Kirleis

Purdue Polytechnic Masters Theses

This thesis covers the methods used to construct and characterize a custom digital RF amplitude control system. Many types of mass spectrometers exist, but few have been miniaturized as much as the Mini instruments developed at Purdue University. The goal of this research was to improve upon an earlier amplitude control system consisting of analog circuits first implemented in the Mini 11.5 mass spectrometer developed at Purdue University.

A custom set of control and data acquisition electronics were developed for testing the digital and analog control systems in a Mini 11.5 mass spectrometer chassis. A MATLAB Simulink simulation was done …

Applied And Mechanistic Studies Of Microbial 17beta-Estradiol Degradation, Zhongtian Li

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The presence of natural estrogens, a class of endocrine disrupting compounds, in water has caused increasing concerns over their adverse impacts on the health of aquatic eco-systems and human beings. In this study, adsorption characteristics of two natural estrogens, 17β-estradiol (E2) and estrone (E1), on granular activated carbon (GAC) were investigated in isotherm tests and in a GAC column. The GAC column was then converted to a biologically active carbon (BAC) column and the removal efficiency of E2 and its primary biodegradation intermediate E1 were monitored. During BAC operation, the impacts of various reactor operation parameters, such as the carbon …

Automating The Fret Slotting Process Using A Plc Controlled 1.5 Axis Mill, James Stratton

Purdue Polytechnic Masters Theses

Stratton, James A. M.S., Purdue University, August 2011. Automating the Fret Slotting Process Using a PLC Controlled 1.5 Axis CNC Mill. Major Professor: Richard Mark French.

Can automation assist small job shops and hobbyists in the production of stringed instruments? This research set out to answer the question using a quantitative approach to determine if an economical CNC machine could be produced in such a fashion as to seamlessly join the workshop as an affordable, yet precise instrument to aid in the production of stringed instruments. The key was to incorporate common industrial automation equipment into the operation of the …

Roadside Grading Guidance, Kevin D. Schrum

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Provisions for the design of roadside foreslopes are not readily available, and as a result, engineering judgment is often employed. Unfortunately, this can lead to inconsistent designs, where, inevitably, some designs will be too costly and other designs will be too dangerous. Therefore, a design guide was created to lend consistency to the design of these foreslopes while maintaining the most economical and safe design.

This design guide was prepared after conducting a benefit-cost analysis using the Roadside Safety Analysis Program (RSAP). A large test matrix was developed in an attempt to simulate the most possible scenarios, leaving interpolation to …

Molecular Dynamics Simulation Based On Hadoop Mapreduce, Chen He

School of Computing: Dissertations, Theses, and Student Research

Molecular Dynamics (MD) simulation is a computationally intensive application used in multiple fields. It can exploit a distributed environment due to inherent computational parallelism. However, most of the existing implementations focus on performance enhancement. They may not provide fault-tolerance for every time-step.

MapReduce is a framework first proposed by Google for processing huge amounts of data in a distributed environment. The simplicity of the programming model and fault- tolerance for node failure during run-time make it very popular not only for commercial applications but also in scientific computing.

In this thesis, we develop a novel communication-free and each time-step fault- …

Theoretical And Experimental Studies Of Noise Limited Phenomena In Nanowires, Pratik Agnihotri

Theses and Dissertations

Electronic noise is an area of fundamental importance that reveals information about the system that transport or optical measurements cannot. The present work focuses on recent advances made in the area of noise in nanodevices. This area is attracting increasing attention because noise in nanostructures is qualitatively and quantitatively different from that in bulk systems. Chapter 1 discusses different kinds of noise in nanostructures with a focus on 1/f noise. Monte-Carlo simulation is used to find velocity as a function of time to calculate velocity autocorrelation function and noise spectral density. The spectrum has 1/f^2 dependence which is universal irrespective …

Networks - Ii: Em-Wave Consideration Through Polarization And Magnetization Effects In Fiber Optics, Hassan Ali, Zain -Ul- Abiden, M. Rizwan Anjum

International Conference on Information and Communication Technologies

Optical fiber communication is the field of the applied science and a promising technique that permits the communication of data in the form of audio and video signal over transparent medium with high data rate over longer distances. Due to the property of fiber optics that it carries high frequency and allows high bandwidth, as the information travels through fiber optic cable in the form of light which belongs to the spectrum of EM wave. The intensity of the electromagnetic radiation decreases in the non conducting medium due to the scattering and absorption of photons. The research on the behavior …

Networks - Ii: Closed-Form Expressions For Correlation Function And Power Density Spectrum In Mimo Mobile-To-Mobile Channels Using Two-Erose-Ring Model, Muahammad Riaz, Noor M. Khan

International Conference on Information and Communication Technologies

This paper presents an extensive study of MIMO channels in mobile-to-mobile environment. Recently proposed two-erose-ring model is reviewed for more details, and closed-form mathematical expressions for space-time correlations and power spectral density for MIMO mobile-to-mobile communication channels are derived. Using the correlation function, we analyze and compare capacity and diversity gains for two-ring model and two-erose-ring model. Furthermore, we compared the results with the existing models.

Networks - Ii: A High Bandwidth Covert Channel In Network Protocol, Mehdi Hussain

International Conference on Information and Communication Technologies

Covert channel is secret communication path, which existence is not expected in original system of design. It allows different users access to the same information, at the same time, but from different points-of-view. It is being more and more studying due to the grooming of internet. Always high-bandwidth network covert channel pose the significant risk of detection over network. Although the existing technique utilized the reserved bits of header, timestamp, initial sequence number, packet length etc for network covert channel, to some extend these have good temper resistance. But when increase their covert data capacity they becomes to fail to …

Network Security: A Review Of Salient Security Aspects Of The Universal Mobile Telecommunication System (Umts), F. Imran, M. Hussain

International Conference on Information and Communication Technologies

Wireless communication is known as key to global development. Wireless and mobile communication is gaining more importance in our life. Protecting information is one the aspects which we need to focus on the wireless networks. Universal mobile telecommunication system (UMTS) is evolution of the third generation mobile communication system. It was built on the success of global system for mobile communication (GSM). Universal mobile telecommunication system's security is also built on global system for mobile communication (GSM). The paper reviews the literature of the security aspects of the Universal mobile telecommunication system. A critical evaluation of the proposed solutions is …