Engineering Commons^™

The Determination Of The Concrete Tensile Creep At Early Age Using The Ring Test, Tadamon Mohammed

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, the modified double power law (MDPL) model is used to determine the tensile creep of concrete at an early age based on the ASTM C1581 restrained shrinkage ring test. Three concrete mixes using Ordinary Portland Cement (OPC) were tested. The three concrete mixes were cast, and each underwent the ring tests up to cracking. Mechanical properties of concrete at the age of 1, 3, 7, 14, and 28 days were tested to find the compressive strength, tensile strength and Young’s Modulus of concrete. The strength tests results were obtained from both 4x8 inch and 6x12 inch cylinders. …

A Proposal For A Technological Solution To Improve User Experience In A Shopping Center Based On Indoor Geolocation Services, Luinel Andrade, Johan Quintero, Eric Gamess, Antonio Russoniello

Research, Publications & Creative Work

For shopping centers, mobile devices and their associated technologies represent great business opportunities and a way to improve the user experience within their facilities. These types of constructions are usually quite large, multi-story, and with a significant number of shops, services, where the visitors may find themselves having difficulties to have a complete and up-to-date list of the stores, determine which stores and services are those that meet the characteristics or specifications they seek, know the location of the shops or how to reach them. This research studies and contemplates different technologies, tools, and approaches for the development of a …

A Proposal For A High Availability Architecture For Voip Telephone Systems Based On Open Source Software, Alejandro Martin, Eric Gamess, Dedaniel Urribarri, Jesús Gómez

Research, Publications & Creative Work

The inherent needs of organizations to improve and amplify their technological platform entail large expenses with the goal to enhance their performance. Hence, they have to contemplate mechanisms of optimization and the improvement of their operational infrastructure. In this direction arises the need to guarantee the correct operation and non-degradation of the services provided by the platform during the periods with a significant load of work. This type of scenario is perfectly applicable to the field of VoIP technologies, where users generate elevated loads of work on critical points of the infrastructure, during the process of interaction with their peers. …

Homogenization And Growth Behavior Of Second-Phase Particles In A Deformed Zr-Sn-Nb-Fe-Cu-Si-O Alloy, Liang-Yu Chen, Peng Sang, Lina Zhang, Dongpo Song, Yanqiu Chu, Linjiang Chai, Laichang Zhang

Research outputs 2014 to 2021

Homogeneous distribution of fine second-phase particles (SPPs) fabricated by cycles of deformation and annealing in zirconium alloys is a critical consideration for the corrosion resistance of fuel claddings. Different deformation degrees of zirconium alloys would result in distinctive microstructures, leading to a distinct growth of SPPs during subsequent annealing. Unfortunately, the homogenization and growth behavior of SPPs in deformed zirconium alloys have not been well studied. In this work, a β-quenched Zr–Sn–Nb–Fe–Cu–Si–O alloy was rolled and annealed at 580◦C or 680◦C. The morphologies, distributions, and sizes of SPPs resulting from the different processing procedures were investigated. A linear distribution of …

Short-Term Load Forecasting Of Natural Gas With Deep Neural Network Regression, Gregory Merkel, Richard J. Povinelli, Ronald H. Brown

Electrical and Computer Engineering Faculty Research and Publications

Deep neural networks are proposed for short-term natural gas load forecasting. Deep learning has proven to be a powerful tool for many classification problems seeing significant use in machine learning fields such as image recognition and speech processing. We provide an overview of natural gas forecasting. Next, the deep learning method, contrastive divergence is explained. We compare our proposed deep neural network method to a linear regression model and a traditional artificial neural network on 62 operating areas, each of which has at least 10 years of data. The proposed deep network outperforms traditional artificial neural networks by 9.83% weighted …

Deep Convolutional Particle Filter With Adaptive Correlation Maps For Visual Tracking, Reza Jilil Mozhdehi, Yevgeniy Vladimirovich Reznichenko, Abubakar Siddique, Henry P. Medeiros

Electrical and Computer Engineering Faculty Research and Publications

The robustness of the visual trackers based on the correlation maps generated from convolutional neural networks can be substantially improved if these maps are used to employed in conjunction with a particle filter. In this article, we present a particle filter that estimates the target size as well as the target position and that utilizes a new adaptive correlation filter to account for potential errors in the model generation. Thus, instead of generating one model which is highly dependent on the estimated target position and size, we generate a variable number of target models based on high likelihood particles, which …

Detection And Quantification Of Multi-Analyte Mixtures Using A Single Sensor And Multi-Stage Data-Weighted Rlse, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco

Electrical and Computer Engineering Faculty Research and Publications

This work reports the development and experimental verification of a sensor signal processing technique for online identification and quantification of aqueous mixtures of benzene, toluene, ethylbenzene, xylenes (BTEX) and 1, 2, 4-trimethylbenzene (TMB) at ppb concentrations using time-dependent frequency responses from a single polymer-coated shear-horizontal surface acoustic wave sensor. Signal processing based on multi-stage exponentially weighted recursive leastsquares estimation (EW-RLSE) is utilized for estimating the concentrations of the analytes in the mixture that are most likely to have produced a given sensor response. The initial stages of EW-RLSE are used to eliminate analyte(s) that are erroneously identified as present in …

Stochastic Search Methods For Mobile Manipulators, Amoako-Frimpong Samuel Yaw, Matthew Messina, Henry P. Medeiros, Jeremy Marvel, Roger Bostelman

Electrical and Computer Engineering Faculty Research and Publications

Mobile manipulators are a potential solution to the increasing need for additional flexibility and mobility in industrial applications. However, they tend to lack the accuracy and precision achieved by fixed manipulators, especially in scenarios where both the manipulator and the autonomous vehicle move simultaneously. This paper analyzes the problem of dynamically evaluating the positioning error of mobile manipulators. In particular, it investigates the use of Bayesian methods to predict the position of the end-effector in the presence of uncertainty propagated from the mobile platform. The precision of the mobile manipulator is evaluated through its ability to intercept retroreflective markers using …

Measurements Of Milli-Newton Surface Tension Forces With Tilted Fiber Bragg Gratings, Changyu Shen, Chuan Zhong, Dejun Liu, Xiokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, John F. Donegan

Articles

Small lateral forces (lower than 0.1 N) cannot normally be measured with conventional single-mode fiber-based sensors because of the high value of their Young modulus (>70 GPa). Here we demonstrate the measurement of lateral forces in the range from 0.2 to 1.4 × 10−3 N with a tilted fiber Bragg grating (TFBG) in conventional single-mode fiber pushed against the surface tension (ST) of a bead of water. The measured transmission changes of individual cladding mode resonances of the TFBG corresponding to these force values are of the order of 29 dB. Separate measurements of the contact angle between the …

Optical Fibre Sensors For Monitoring Phase Transitions In Phase Changing Materials, Rahul Kumar, Wei Han, Dejun Liu, W. P. Ng, Binns, Richard Binns, Richard, Krishna K. Busawon, Yong Qing Fu, Zabih Ghassemlooy, Chris P. Underwood, Khamid Kh Mahkamov, Jinhui Yuan, Chongxiu Yu, Huazhong Shu, Xing Ao Li, Tuan Guo, Gerald Farrell, Yuliya Semenova, Qiang Wu

Articles

A platinum coated singlemode-multimode (SM) structure is investigated in this paper as an optical fibre sensor (OFS) to monitor the phase transition of a phase change material (PCM). Paraffin wax has been used as an example to demonstrate the sensor's performance and operation. Most materials have the same temperature but different thermal energy levels during the phase change process, therefore, sole dependency on temperature measurement may lead to an incorrect estimation of the stored energy in PCM. The output spectrum of the reflected light from the OFS is very sensitive to the bend introduced by the PCM where both liquid …

Formation And Development Of Nanometer-Sized Cybotactic Clusters In Bent-Core Nematic Liquid Crystalline Compounds, Yuri Panarin, Sithara P. Sreenilayam, Jagdish K. Vij, Anne Lehmann, Carsten Tschierske

Articles

Two homologue achiral bent-core liquid crystals (LCs), BCN66 and BCN84, in their nematic phases are studied by dielectric spectroscopy in the frequency range 10 Hz–10 MHz. In each of these compounds, two relaxation processes are identified and assigned to (i) collective dynamics of molecules in nanometer-sized cybotactic clusters and (ii) individual molecular relaxations, in the ascending order of frequency of the probe field. The temperature and the bias electric field dependence of the dielectric strength and relaxation frequency for these processes are shown to give rise to sharpness in cluster boundaries, increased size and volume fraction in the LC nematic …

The Role Of The Dendritic Growth Models Dimensionality In Predicting The Columnar To Equiaxed Transition (Cet), M. Seredyński, Marek Rebow, J. Banaszek

Articles

The dendrite tip kinetics model accuracy relies on the reliability of the stability constant used, which is usually experimentally determined for 3D situations and applied to 2D models. The paper reports authors` attempts to cure the situation by deriving 2D dendritic tip scaling parameter for aluminium-based alloy: Al-4wt%Cu. The obtained parameter is then incorporated into the KGT dendritic growth model in order to compare it with the original 3D KGT counterpart and to derive two-dimensional and three-dimensional versions of the modified Hunt’s analytical model for the columnar-to-equiaxed transition (CET). The conclusions drawn from the above analysis are further confirmed through …

An Lcl-Filter Design With Optimum Total Inductance And Capacitance, Sampath Jayalath, Mohamed Moin Hanif

Articles

LCL-filter is among the best performing filters for grid-connected voltage source inverters. Designing of the filter parameters (grid-side and inverter-side inductors and capacitor), takes an iterative approach due to the coherence between the parameters and design requirements such as IEEE-519 Std for harmonic current limitations, reactive power compensation limit, and maximum allowable voltage drop across the filter to limit the switching losses. Most of the proposed LCL-filter optimization strategies emphasize on reducing the total inductance and losses of the filter while meeting the design requirements. There is less emphasis given on the capacitor selection and optimizing its value. Therefore, this …

A Coated Spherical Micro-Resonator For Measurement Of Water Vapor Concentration At Ppm Levels In Very Low Humidity Environments, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova

Conference Papers

This paper presents a novel approach to measurements of low relative humidity (RH) values based on the whispering gallery modes (WGMs) effect in a small silica microsphere coated with a thin layer of Agarose hydrogel. The light from a narrow-linewidth tunable laser with a few GHz tuning range is launched into an adiabatic tapered fiber, which excites WGMs in the Agarose layer via evanescent coupling. Adsorption and desorption of water vapor by the Agarose layer in response to changes in ambient humidity lead to changes in the layer’s refractive index, which in turn leads to a spectral shift of the …

Task Complexity, And Operators’ Capabilities As Predictor Of Human Error: Modeling Framework And An Example Of Application, Maria Chiara Leva, Alberto Caimo, Rebecca Duane, Micaela Demichela, Lorenzo Comberti

Conference Papers

This paper presents the initial framework adopted to assess human error in assembly tasks at a large manufacturing company in Ireland. The model to characterize and predict human error presented in this paper is linked conceptually to the model introduced by Rasch (1980), where the probability of a specified outcome is modelled as a logistic function of the difference between the person capacity and item difficulty. The model needs to be modified to take into account an outcome that is not dichotomous and feed into the interaction between two macro factors: (a) Task complexity: that sum-marises all factors contributing to …

Molecular Dynamics Simulation Of Gas Transport And Adsorption In Ultra-Tight Formations, Yannick Tambe Agbor

Theses and Dissertations

Kerogen, which plays a very important part in reservoir characterization for ultra-tight formations, is also involved in the storage and production of hydrocarbons in shale. In this work, we study the kerogen structure and its interaction with insitu hydrocarbons to fully understand the fluid flow and adsorption mechanisms in the shale. Also the advancement in pore network modelling has greatly helped the understanding of mesoscale fluid flow. In this work, transport of methane in a type II marine environment kerogen model is studied using molecular dynamics simulations. Non Equilibrium Molecular Dynamics Simulations (NEMDS) using GROMACS code and Grand Canonical Monte …

Entrepreneurial Mindset: Integrating Creative Thinking And Innovation Into A Graphical Communications Course, Leroy Long Iii, Lulu Sun

Publications

Nationwide, leaders in business and industry have increasingly acknowledged the importance of entre¬preneurship. Several areas of the country showcase the importance of entrepreneurship such as Silicon Valley in California where a large number of start-up companies in science, technology, engineering and math (STEM) fields are located. To meet the needs of business and industry, institutions of higher educa¬tion prepare students for future employment by offering rigorous and relevant coursework in areas such as entrepreneurship. Collegiate faculty and staff can use fundamental engineering courses to instill an en¬trepreneurial mindset – a set of beliefs, attitudes, and behaviors that drive innovation – …

Infographic: Institutional Barriers To Black And Latino Male Collegians’ Success In Engineering And Related Stem Fields, Leroy L. Long Iii, William Wanyagah

Publications

Infographic was created to support the article Institutional Barriers to Black and Latino Male Collegian's Success in Engineering and Related Stem Fields, which can be read here:

Study Of 4h-Sic And Alxga1-Xn Based Heterojunction Devices For Ultraviolet Detection Applications, Venkata Surya Naga Raju Chava

Theses and Dissertations

Ultraviolet (UV) detectors are important for their applications in flame detection, furnace gas control systems, plume monitoring etc. Due to their wide band-gap, 4H-SiC (Eg=3.26eV) and III-V semiconductors such as GaN (Eg=3.4eV), AlxGa1-xN (Eg=3.4eV to 6.2eV) etc., are excellent candidates for visible(��cut-0ff=400nm) and solar blind(��cut-0ff=290nm) UV detectors. Conventional SiC UV detectors suffer from poor UV responsivities due to reflection/absorption/transmission losses caused by the metal electrodes used in those detectors.

In the first part, a novel bipolar transistor with epitaxial graphene(EG)/p-SiC (30μm)/n+-SiC substrate was fabricated and characterized. The 2-3 ML thick, transparent and conducting, EG used in this work was grown …

The Rational Synthesis Of Bimetallic Catalysts On Oxide Supports, Andrew Phillip Wong

Theses and Dissertations

Catalysts play an important role in many chemical reactions. However, simple impregnated monometallic catalysts are often limited in their function. One way to overcome this limitation is through the incorporation of a secondary metal to the catalysts. These bimetallic catalysts often have synergistic benefits not observed in the monometallic analogues. Here, we focused on the synthesis of bimetallic catalysts using rational methods in order to improve catalyst function; specifically by tuning the particle size, morphology, and composition. The two methods of interests were Strong Electrostatic Adsorption (SEA) and Electroless Deposition (ED). An adaptation of SEA to bimetallic catalysts (coSEA) was …

Monitoring The Progress Of Damage In A Sicf-Sicm Composite Nuclear Fuel Cladding Under Internal Pressure Using Acoustic Emission, Luis H. Alva

Theses and Dissertations

The relation between the progress of damage and the acoustic emission (AE) activity of a nuclear grade Sif-SiCm composite tubing under internal pressure was studied. The nuclear grade Sif-SiCm composite tubing is manufactured by the company General Atomics (GA) and made of nuclear grade HI Nicalon type S fiber preforms following a chemical vapor infiltration (CVI) technique. Sif-SiCm composites are good candidates to replace current nuclear fuel cladding materials because of the good chemical stability and strength at high temperatures. In this work, a Sif-SiCm composite tubing was tested under internal pressure at room temperature (RT) to study the damage …

Multifunction Radio Frequency Composite Structures, David L. Zeppettella

Theses and Dissertations

There has been recent interest in the development of multifunction structures for weight-critical applications. A multifunction structure is a load-bearing structure that also allows one or more additional functions such as RF communication, energy storage, sensing etc. The focus of this dissertation is to analyze, design, develop, and test new high performance (broadband, high gain, circularly polarized) internal antennas that are structural and integral to the aircraft. It is demonstrated that antennas with more bandwidth and higher efficiency could be developed if the space and materials available in an aircraft structure could be judiciously exploited for multifunctional usage. This is …

Combinatorial Study Of Oxidation Catalysts: Uncovering Synthesis-Structure-Activity Relationships, Kathleen B. Mingle

Theses and Dissertations

High throughput experimentation (HTE) in catalysis has proven useful in expediting materials discovery via parallelized synthesis, characterization, and testing of candidate materials. However, even in a high-throughput manner, the combinatorial explosion of relevant parameters far exceeds our ability to study. To further complicate the problem, a large time investment and great deal of characterization is often required to build an in-depth understanding of catalytic materials. It follows that the field of heterogeneous catalysis is rich with examples of catalytic systems that have been developed using trial and error efforts for which a lot is known but context is lacking. Techniques …

Role Of Bed Design Characteristics On The Effective Thermal Conductivity Of A Structured Adsorbent, Pravin Bosco Charles Antony Amalraj

Theses and Dissertations

This work evaluates the role of different design variables on the effective thermal conduction of a structured adsorbent bed for its possible application in a temperature swing adsorption (TSA) process. The structured adsorbent bed is represented by eight parallel layers of intercalated smooth and corrugated foils of a metal support coated with 13X zeolite resulting in the formation of parallel triangular channels. The variables investigated include the thickness of the adsorbent coating, thickness of the metal, nature of contacts between smooth and corrugated foils, type of metal, presence and magnitude of an air gap between the foils, difference in alignment …

High Temperature Compression Creep Of U3si2, Emil Angelo Cahanap Mercado

Theses and Dissertations

As a result of the Fukushima Daiichi Nuclear Disaster in 2011, a push for increasing the safety of nuclear power plants was made through research grants funded through the United States Department of Energy via the Accident Tolerant Fuels (ATF) campaign. One of the focuses of the campaign is improving the accident tolerance of nuclear fuel during a loss of coolant accident.

A promising set of being researched from the ATF is Silicon Carbide (SiC) composite cladding and Uranium Silicide (U3Si2) fuel pellets. Under high temperatures, stresses, and times the creep deformation can play an important factor in pellet to …

The Visual Ecology Of Speyeria Mormonia, Natalie Sanchez Gonzalez

Theses and Dissertations

Variations in environmental factors such as temperature, precipitation, and day length during larval development are known to affect morphological traits in butterflies related to their visual ecology, including eye size and wing color. These vision-related traits are important for the ability of diurnal butterfly species to detect mates, especially at long distances. Thus, changes in environmental conditions may result in phenotypic modifications to butterflies which may alter their visual ecology and subsequently, their reproductive fitness. To study the interaction of phenotypic plasticity and visual ecology in the Mormon Fritillary, Speyeria mormonia, I set up a natural-laboratory experiment at the Rocky …

Sand Distribution Effect On Three Dimensional Printed Sand Properties, Kip Woods

Dissertations and Theses @ UNI

The purpose of this study was to assess the performance characteristics of commercially available round grain silica sand for the use in three-dimensional sand printers. Two different average diameters were selected to examine the effects of screen distribution on printing performance; these diameters were 57-grain fineness number (GFN) and 70 GFN. These sands were a high purity round grain silica and had low trace contaminates, to reduce any possible influence from contaminates.

The resin system utilized in this investigation was a commercially available Furan resin system. Two test specimens were used in this study the American Foundry Society (AFS) tensile …

Screening Of Novel Active Salicylic Acid Analogs And Identification Of A Bacterial Effector Targeting Key Proteins Involved In Salicylic Acid-Mediated Defense, Ian Palmer

Theses and Dissertations

The master regulator of salicylic acid (SA)-mediated plant defense, NPR1 (NONEXPRESSER OF PR GENES 1), and its paralogs NPR3 and NPR4 act as SA receptors. After the perception of a pathogen, plant cells produce SA in the chloroplast. In the presence of SA, NPR1 protein is reduced from oligomers to monomers, and translocated into the nucleus. There, NPR1 binds to TGA and WRKY transcription factors to induce expression of plant defense genes. EDS1 and PBS3 are two key proteins involved in SA biosynthesis. Previous research has shown that several plant pathogens produce SA hydroxylases. These pathogen-produced hydroxylases act to degrade …

Development Of Advanced Mixed Electronic And Carbonate Ion Conducting Membranes And Reactors For Combined Co2 Capture And Conversion, Jie Fang

Theses and Dissertations

Global warming and climate change resulted from CO2 emissions have been increasingly observed to impact our daily life and damage our economy in recent human history. To deal with this grand challenge, carbon capture and storage (CCS) has been established as a key technology to curb CO2 emission from fossil-fueled power plants. The core of the CCS technology is to capture CO2 at emission sources and geologically bury it for permanent storage or enhanced oil recovery (OER). As the first step of CCS, carbon capture technologies are currently being developed for three power-generation related combustion processes that are responsible for …

Nox Formation In Syngas/Air Combustion, Nazli Asgari

Theses and Dissertations

Syngas is a reliable energy source derived from the gasification of coal and other solid fuels. The feedstock type and the production process of syngas can affect the composition of syngas. Gas turbines utilizing high hydrogen content (HHC) fuels like syngas for power generation applications need to meet stringent pollutant emission standards, particularly with respect to nitrogen oxides (NOx). For gas turbine conditions, reliable experimental data, especially at high-pressure, is necessary for both generating accurate NOx prediction models and improving reaction pathways regarding the NOx chemistry. In this study, NOx formation in post-flame gases of syngas combustion at different conditions …