Engineering Commons^™

Particle Slip Velocity Influences Inertial Focusing Of Particles In Curved Microchannels, Saurabh Deshpande, Phanindra Tallapragada

Publications

Size based separation and identification of particles in microfluidics through purely hydrodynamic means has gained significant interest due to a number of possible biomedical applications. Curved micro-channels, particularly spiral micro-channels with rectangular cross-section and the dynamics of particles in such channels have been extensively researched to achieve size based separation of particles. In this paper we present evidence that sheds new light on the dynamics of particles in such curved channels; that a unique particle slip velocity is associated with the focusing positions in the cross sections, which leads to a balance of forces. Our experiments therefore imply that the …

Code Smells For Model-View-Controller Architectures, Maurício Aniche, Gabriele Bavota, Christoph Treude, Marco Aurélio Gerosa, Arie Van Deursen

Research Collection School Of Computing and Information Systems

Previous studies have shown the negative effects that low-quality code can have on maintainability proxies, such as code change- and defect-proneness. One of the symptoms of low-quality code are code smells, defined as sub-optimal implementation choices. While this definition is quite general and seems to suggest a wide spectrum of smells that can affect software systems, the research literature mostly focuses on the set of smells defined in the catalog by Fowler and Beck, reporting design issues that can potentially affect any kind of system, regardless of their architecture (e.g., Complex Class). However, systems adopting a specific architecture (e.g., the …

Customer Segmentation Using Online Platforms: Isolating Behavioral And Demographic Segments For Persona Creation Via Aggregated User Data, Jisun An, Haewoon Kwak, Soon‑Gyo Jung, Joni Salminen, Bernard J. Jansen

Research Collection School Of Computing and Information Systems

We propose a novel approach for isolating customer segments using online customer data for products that are distributed via online social media platforms. We use non-negative matrix factorization to first identify behavioral customer segments and then to identify demographic customer segments. We employ a methodology for linking the two segments to present integrated and holistic customer segments, also known as personas. Behavioral segments are generated from customer interactions with online content. Demographic segments are generated using the gender, age, and location of these customers. In addition to evaluating our approach, we demonstrate its practicality via a system leveraging these customer …

A Comparative Study Of Contact Stress From Different Standards For Some Theoretical Straight Bevel Gear Pairs, Edward E. Osakue, Lucky Anetor

Faculty Publications

ANSI/AGMA 2003-B97, ISO 10300 standards and a new contact stress model are used to estimate and compare contact stresses in some theoretical straight bevel gear pairs. The contact stress expressions in the different gear standards and new model are formatted to highlight the similarity and differences. The power range of 10 to 15,000 kW, backend modules of 2.5 to 25 mm and backend pitch velocities of 4.58 to 25.37 m/s are covered. The results indicate that the percentage differences between the new contact stress and AGMA models are in the range of 2.22% to 7.40%. These differences are small but …

Biofidelic Piezoresistive Sandwich Composites, Nengda Jiang

Doctoral Dissertations and Master's Theses

Silicone based biofidelic surrogates are being used in many biomedical applications; e.g. to understand the body injury mechanisms, evaluate protective equipment like helmets and armors. Apart from matching the mechanical behavior of bodily tissues, there is an increasing requirement for these materials to be electrically conductive and piezoresistive to facilitate direct instrumentation. Carbon nanotubes (CNTs) are a possible filler to impart electrical conductivity and piezoresistivity to silicone biofidelic materials. A sandwich structure of silicone and CNT sheet, comprising two dielectric facesheets and a highly conductive core layer has added advantages of raising the dielectric permittivity and suppressing dielectric loss.

In …

Studying The Applicability Of Biostimulated Calcite Precipitation In Stabilizing Expansive Soils, Md Touhidul Islam

Boise State University Theses and Dissertations

Of the four types of soils, clays are often associated with issues related to low bearing capacity, high compressibility, swelling and shrinking nature. For example, expansive soils swell and shrink with moisture ingress and digress and are prevalent in several parts of the world causing billions of dollars in damages annually to various civil infrastructures. Several ground improvement techniques such as chemical stabilization, deep soil mixing, moisture barriers, and others were employed to counteract these soils. However, these methods are impractical in certain situations and unsustainable in others due to their economic and environmental impacts. Microbiological treatment of soils could …

Irradiation Effects On Titanium Dioxide Electrodes For Lithium Ion Batteries, Kassiopeia Ann Smith

Boise State University Theses and Dissertations

This dissertation presents the mechanisms of irradiation induced defects and the resulting electrochemical response of TiO₂ anode for _­lithium-ion-batteries. The objective is to realize pathways by which irradiation could be used to enhance the energy density of rechargeable lithium ion batteries in order to provide power to applications under extreme environments. Recent studies suggest that the presence of structural defects (e.g. vacancies and interstitials) in metal oxides may enhance the electrochemical charge storage capacity in electrode materials. One approach to induce defect formation in electrode materials is to use ion irradiation, which has been proven to produce point …

New Methods For Understanding And Controlling The Self-Assembly Of Reacting Systems Using Coarse-Grained Molecular Dynamics, Stephen Thomas

Boise State University Theses and Dissertations

This research aims at developing new computational methods to understand the molecular self-assembly of reacting systems whose complex structures depend on the thermodynamics of mixing, reaction kinetics, and diffusion kinetics. The specific reacting system examined in this study is epoxy, cured with linear chain thermoplastic tougheners whose complex microstructure is known from experiments to affect mechanical properties and to be sensitive to processing conditions. Mesoscale simulation techniques have helped to bridge the length and time scales needed to predict the microstructures of cured epoxies, but the prohibitive computational cost of simulating experimentally relevant system sizes has limited their impact. In …

Experimental And Numerical Investigation On The Bond Strength Of Self-Sensing Composite Joints, Shafique Ahmed, Thomas Schumacher, Jennifer Mcconnell, Erik T. Thostenson

Civil and Environmental Engineering Faculty Publications and Presentations

Laboratory experiments demonstrate that a novel carbon nanotube (CNT)-based sensing layer embedded in the bondline of an adhesively bonded structural joint can detect and monitor deformation and damage progression of the adhesive layer. In this study, experimental and numerical investigations were performed to identify any effect of an embedded CNT-based sensing layer on the bond strength of that joint. To evaluate the mechanical behavior of such a bondline configuration, two sets of single-lap specimens, with and without sensing layer, were prepared and tested to determine the bond strengths of the respective types. Two-dimensional digital image correlation (2D DIC) was utilized …

Translating Data From The Laboratory Into Simulation: A Computational Framework For Subject-Specific Finite Element Musculoskeletal Simulation, Donald R. Hume

Electronic Theses and Dissertations

Computational modeling is a powerful tool which has been used to inform decisions made by engineers, scientists, and clinicians for decades. Musculoskeletal modeling has emerged as a computational modeling technique used to understand the interaction between the body and its surroundings. There are several common approaches used for musculoskeletal modeling which take advantage of different model formulations to obtain information of interest. Unfortunately, models with different joint formulations inherit disparities in representations of ligament, muscle, and cartilage at joints of interest. These differences affect the way the joint functions and limit the insight it provides through computational analysis. Musculoskeletal models …

Mitigating Accumulation Of Aeolian Dust Particles On Solar Power Generator Panels Without Water, Sanjana Das

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accumulation of dust on solar panels poses a serious problem as it can significantly reduce light absorption and electrical energy output. Several factors affect the dust accumulation such as location, dust properties, wind velocity, system orientation, ambient temperature, humidity, and panel surface properties. Experimental and theoretical studies show that short circuit current and maximum power output of photovoltaic panels reduce approximately linearly with dust concentration. Incidentally, the locations with higher solar energy concentrations are also arid or semi-arid regions with higher dust concentrations. In order to avoid loss in power output, most PV installations perform periodic panel cleaning with water. …

Conformal Mapping Improvement Of The Boundary Element Method Solution For Underground Water Flow In A Domain With A Very Singular Boundary, Megan Romero

UNLV Theses, Dissertations, Professional Papers, and Capstones

Numerical solutions using a Boundary Element Method (BEM) for a confined flow in a very singular finite domain are developed. Typically, in scientific journal publications, authors avoid domains with many and more malignant singularities due to the extremely big and difficult to estimate errors in the numerical calculations. Using exact Conformal Mapping solutions for simplified domains with the same singularity as in the original domain, this problem can be solved numerically with improvements introduced by Conformal Mapping solutions. Firstly, to experiment with improving the BEM solution by Conformal Mapping, a domain inside a rectangle is considered. The exact solution inside …

Secure Device And Knowledge Discovery In Internet Of Things, Shahab Taregh Tayeb

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the ever-growing adoption of Internet of Things (IoT), there is continued development and deployment of new nodes with various capabilities and services. Such heterogeneity introduces complexity and a significant need for neighbor service discovery frameworks. Because the types of services available are orders of magnitude more than pre-IoT era, researchers need new techniques to accurately discover not only the topologies and adjacencies but also the capability of other nodes and neighbors. Device discovery is usually the first task to be performed, immediately after deployment, as it enables communications, scheduling, and channel estimation. The existing discovery mechanisms do not consider …

Comprehensive Study Of Spray-Painting And 3d Printing Fabrication Methods For Nafion® And Nafion® Equivalents In Ionic Polymer-Metal Composite Actuators And Sensors, Sarah Trabia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ionic Polymer-Metal Composites (IPMC) are smart materials that are useful in different applications because of their low voltage requirements and light weight. IPMC are made of ion- conducting polymer (ionomer) plated with a noble metal, such as platinum. When a voltage potential is applied to the surface of the IPMC, it creates an electro-mechanical effect, causing it to actuate. This is due to the motion of the cations towards the negatively charged side of the IPMC, causing it to swell, and in turn, bend. Conversely, deforming an IPMC moves cations within it, which produces a small voltage that can be …

Investigations Into The Airside Cooling Of A Heat Exchanger, David Vallet

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study we investigate the air-side cooling of a flat-plate fin and tube heat transfer condenser with numerical simulations. A new design is proposed which utilises vortex generators to direct the flow in such a way as to remove some of the stagnant heated air that collects in the wake of the pipes. A comparative study of the proposed design and a standard tube and fin condenser is conducted by varying the air side entrance velocities. The Shear Stress Tension, SST $\kappa - \omega$ 2-equation turbulent model is used to solve the RANS model in ANSYS Fluent 18. The …

The Effect Of Titanium Dioxide On Nucleate Pool Boiling Using An Aluminum Substrate, Kevin Yim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nucleate pool boiling is a mode of pool boiling that tends to transfer heat more efficiently than the other modes of pool boiling. Many studies have been done to augment the heat transferred during nucleate pool boiling. Various methods of heat transfer augmentation in

boiling can be performed through active treatments (mechanical aids, surface/fluid vibrations, etc.) or passive treatments (functional coating, surface roughening, etc.). This study focuses primarily on a passive treatment, specifically TiO2 coating, which involves testing a substrate coated with TiO2 using NeverWetTM base coating as a coupling agent and coated using a method outlined by Wu et …

Investigations On Hydrothermally Synthesized Co3o4/Mnxco3-Xo4 Core-Shell Nanoparticles, Ning Bian

Graduate Theses/Dissertations

Two different morphologies (pseudo-spherical shaped or PS type and hexagonal nanoplate shaped or NP type) and two different concentrations (0.07 M and 0.1 M) of manganese incorporated Co₃O₄@Mn_xCo_3-xO₄ core-shell nanoparticles (CSNs) were investigated, respectively. The motivation of this work is to investigate the magnetic properties of, and specifically the exchange bias, between different shaped CSNs and between different Mn-doped CSNs. A two-step synthesis method was utilized to obtain the CSNs: a soft chemical approach was used to obtain Co₃O₄ nanoparticles and a hydrothermal nano-phase epitaxy was used to …

Feasibility Of Aerial Tramway At Boise State University, Majed Alsaqyani

Boise State University Theses and Dissertations

The use of aerial tramways is becoming common in cities as a way to provide reliable, safe, sustainable, and cost-effective mass transportation. The aerial tramway is especially effective in the most congested areas of major cities. The growth of Boise State University (BSU) and downtown Boise makes this location especially attractive for a tramway. Moreover, based on data collected for this analysis, it is clear that the BSU community is open to using the tramway instead of more traditional modes of transportation.

The viability of the tramway is further enhanced because the computer science department has moved to City Center …

Smart Adaptive Beam-Forming Antenna Design For Next Generation Communication Systems, Ahmed Umar Kausar

Boise State University Theses and Dissertations

Adaptive beamforming antennas open a new venue for research to achieve high data rates. Such antennas are of interest at higher frequencies, especially at millimeter-waves. Millimeter-wave band ranges from 30 GHz - 300 GHz. There is an ample bandwidth available in this spectrum. However, due to the significant path loss at high frequencies, there is a need for better error correction schemes and adaptive beam-forming antennas for this frequency band.

The goal of our research is to design a novel adaptive beamforming smart antenna that is low cost, compact, power-efficient and less complex. Based on our recently awarded US patent, …

Improving And Augmenting The Anm Model For Three-Dimensional Virtual Concrete, Stephen Thomas

Boise State University Theses and Dissertations

The Anm model used for creating virtual concrete consisting of irregular shapes has been improved by integrating two existing algorithms: the extent overlap box (EOB) method for detecting contact between two irregular shapes and the uniform thickness shell algorithm. The EOB method has been compared with the previously used Newton-Raphson method and shown to be able to detect inter-particle contact with better accuracy and with less computational cost. Two parameters that define the balance between accuracy and performance of the EOB method have been identified and studied. The uniform thickness shell has been used to specify the minimum inter-particle distance …

Statistical Meta-Model For Air Traffic Flow And Capacity Management Based On Airspace Optimization-Simulation: The Continuous Challenge Of The Hub Of The America Congestion, Juan Marcos Castillo

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Panama is only Country on the Americas with a Canal and the hub of Logistics that include the interaction of the Atlantic and the Pacific in a less than a day. This Logistics growth after the Panama Canal Expansion resulted in an overwhelming growth in Aviation. Furthermore, the economic and Logistic growth at Panama is increasing the demand of air transportation and it is creating potential for Air Logistics. Thus, the air traffic congestion is one of the greatest challenges that the Aviation Industry is seeking to address. The objective of this research is to understand if the Air Traffic …

Serialised Holography For Brand Protection And Authentication, Dinesh Vather, Izabela Naydenova, Dervil Cody, Monika Zawadzka, Suzanne Martin, Emilia Mihaylova, Stephen Curran, Paul Duffy, Josune Portillo, Daniel Connell, Stephen Mcdonnell, Vincent Toal

Articles

The problems presented by counterfeit products and documentation are discussed. Limitations of existing holograms for anti-counterfeit applications are described. We describe the advantages of full holographic serialisation and the requirements in terms of materials and techniques for mass production of true serialised holograms. These requirements having been met, we report for the first time the mass production of fully serialised holograms. The novelty of approach consists of the direct use of product manufacturer’s information as the object in a holographic recording system along with a self-processing photopolymer and modular optical system to facilitate mass production of truly serialised volume holograms. …

Time Evolution Of Ecog Network Connectivity In Patients With Refractory Epilepsy, Michael J. Selesko

Masters Theses

Epilepsy is a common neurological disorder that causes recurrent, unprovoked seizures. Focal, refractory epilepsy is characterized by seizures that start in a specific area in the brain and do not respond to antiepileptic medication. This study was conducted to characterize the connectivity of the focal brain region where seizures originate, known as the epileptogenic zone. Connectivity was measured from electrocorticogram (ECoG) recordings, during seizure events, using information theoretic measures mutual information (MI) and (TE). MI is the amount of information shared between two discrete random variables. TE is the directed information transfer between two discrete random variables. MI provides information …

A Case Study On Application Of Fuzzy Logic Based Controller For Peak Load Shaving In A Typical Household's Per Day Electricity Consumption, Krishna P. Sharma

Masters Theses

The cost of electricity for consumers depends on the cost of generation, transmission, and distribution of power. The electrical load consumed by consumers per day is not constant throughout the day. The utilities must be capable of meeting the load demand, which means they must have enough electricity generation potential and necessary infrastructure. This cost is significant. However, the revenue they generate will only be for the actual use of electricity by the consumers. In general, the electrical power generation is done in stages, always generating a base load. As demand changes throughout the day, additional stages of power generation …

Identification Of The Seizure Onset Zone By Auto-Regressive Model Residual Modulation Applied To Intracranial Eeg And Its Correlation To Channels With High Preponderances Of Detected Hfos, Allison L. Rogutich

Masters Theses

The objective of this thesis was to examine the ability of the Autoregressive Model Residual Modulation (ARRm) method to identify the Seizure Onset Zone (SOZ) in intracranial electroencephalogram (iEEG) of patients with refractory epilepsy. Patients who have not become seizure free after multiple trials of antiepileptic drugs (AEDs) may seek treatment through epilepsy surgery. Cortical electrodes are implanted directly on the cerebral cortex, then iEEG is collected. A specialized neurologist reviews the iEEG, then in consultation with the neurosurgeon, the SOZ is determined and areas of the brain may be chosen for resection. The success rate of epilepsy surgery varies, …

Modeling Of Cold Compressor Pump Down Process, Kyle A. Dinger

Masters Theses

The Facility for Rare Isotope Beams (FRIB) will use a sub-atmospheric helium refrigeration process operating at 2 K (31 mbar) to support the superconducting radio frequency (SRF) Niobium structures (known as cavities), which are housed within ‘cryo-modules’. The cryomodules are large containers whose exterior forms a vacuum chamber that serves as a thermal shield. The cryo-modules, and the superconducting devices contained within, are used to accelerate charged particles. The accelerator at FRIB is comprised of three separate linear segments, separately or collectively, called a linear accelerator or ‘LINAC’. The helium used as the working fluid to cool the SRF Niobium …

Pnnl Dark Matter Bubble Chamber, Ryan Robinson

STAR Program Research Presentations

The Pacific Northwest National Laboratory (PNNL) prototype bubble chamber is intended to address issues encountered with the current PICO dark matter search detectors and improve the functionality of future experimental designs. The PNNL bubble chamber accomplishes this with a simplified interface between the hydraulic pressure controls and the target vessel and altering the standard chamber design such that it can be easily exchanged and replaced with vessels of various sizes and materials for testing purposes. The chamber itself is a glass vessel which houses perfluorobutane and holds the target fluid above room temperature and atmospheric pressure. The target fluid becomes …

Finite-Time Anti-Synchronization Of Memristive Stochastic Bam Neural Networks With Probabilistic Time-Varying Delays, Manman Yuan, Weiping Wang, Xiong Luo, Linlin Liu, Wenbing Zhao

Electrical and Computer Engineering Faculty Publications

This paper investigates the drive-response finite-time anti-synchronization for memristive bidirectional associative memory neural networks (MBAMNNs). Firstly, a class of MBAMNNs with mixed probabilistic time-varying delays and stochastic perturbations is first formulated and analyzed in this paper. Secondly, an nonlinear control law is constructed and utilized to guarantee drive-response finite-time anti-synchronization of the neural networks. Thirdly, by employing some inequality technique and constructing an appropriate Lyapunov function, some anti-synchronization criteria are derived. Finally, a number simulation is provided to demonstrate the effectiveness of the proposed mechanism.

Methods And Metrics To Measure And Predict The Social Impact Of Engineered Products, Phillip Douglas Stevenson

Theses and Dissertations

More than ever before, engineers are creating products for developing countries. One of the purposes of these products is to improve the consumer's quality of life. Currently, there is no established method of measuring the social impact of these types of products. As a result, engineers have used their own metrics to assess their product's impact, if at all. Some of the common metrics used include products sold and revenue, which measure the financial success of a product without recognizing the social successes or failures it might have. In this thesis I introduce a potential metric, the Product Impact Metric …

Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Taylor Ingersoll

Theses and Dissertations

Improving the wind turbine blade design has a significant effect on the efficiency of the wind turbine. This is a challenging multi-disciplinary optimization problem. During the blade design process, the aerodynamic shapes, sizing of the structural members, and material composition must all be determined and optimized. Some previous blade design methods incorporate the wind turbine's static response with an added safety factor to account for neglected dynamic effects. Others incorporate the dynamic response, but in general is limited to a few design cases. By not fully incorporating the dynamic response of the wind turbine, the final turbine blade design is …