Engineering Commons^™

Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Inconel 617 And Nimonic 105, Vito Cedro Iii, Christian Garcia, Mark Render

Mechanical Engineering Faculty Publications and Presentations

Advanced power plant alloys must endure high temperatures and pressures for durations at which creep data are often not available, necessitating the extrapolation of creep life. A recently developed creep life extrapolation method is the Wilshire equations, with which multiple approaches can be used to increase the goodness of fit of available experimental data and improve the confidence level of calculating long-term creep strength at times well beyond the available experimental data. In this article, the Wilshire equation is used to extrapolate the creep life of Inconel 617 and Nimonic 105 to 100,000 h. The use of (a) different methods …

A Parametric Study Of Wave Interaction With A Rotor Having Hydrofoil Blades, Yingchen Yang, Fredrick A. Jenet, Ben Xu, Juan Carlos Garza, Benjamin Tamayo, Yessica Chavez, Oscar Reyes, Samuel Fuentes

Mechanical Engineering Faculty Publications and Presentations

Our recent progress on studying wave interaction with a lift-type rotor is discussed in this paper. The particular focus is on characterization of the rotor’s unidirectional responsiveness in waves. The rotor consists of six hydrofoil blades in two sets. One blade set has three blades laid out as a vertical-axis wind turbine of the Darrieus type. The other blade set has three blades configured like a Wells turbine. In combination, the formed rotor can be driven by flows in any direction to perform unidirectional rotation about its vertically mounted shaft. This unidirectional responsiveness of the rotor also holds in waves, …

Ion-Sensitive Field-Effect Transistors With Micropillared Gates For Measuring Cell Ion Exchange At Molecular Levels, Mohammad G. Abdallah, Rayan Khan, Christian Garcia, Young-Tae Kim, Samir M. Iqbal

Electrical and Computer Engineering Faculty Publications and Presentations

The detection of small concentrations of cancer cells before cancer takes over the primary organ completely, or metastasizes to other areas of the body is important for early screening of cancer. One approach to address cancer early screening is through cell ion exchange bioelectricity, which characterizes voltage potential in non-neuronal cells to regulate shape changing, proliferation, differentiation, migration, and cancer formation. Herein, novel ion-sensitive field-effective transistor (ISFET) modality is shown to measure cell behavior during the change of cell properties at molecular levels. ISFETs produce low resistance signals and consume low power. The small size of ISFETs enables miniature diagnosis …

Use Of The Wilshire Equations To Correlate And Extrapolate Creep Data Of Hr6w And Sanicro 25, Vito Cedro Iii, Christian Garcia, Mark Render

Mechanical Engineering Faculty Publications and Presentations

Advanced power plant alloys must endure high temperatures and pressures for durations at which creep data are often not available, necessitating the extrapolation of creep life. Many methods have been proposed to extrapolate creep life, and one of recent significance is a set of equations known as the Wilshire equations. With this method, multiple approaches can be used to determine creep activation energy, increase the goodness of fit of available experimental data, and improve the confidence level of calculating long-term creep strength at times well beyond the available experimental data. In this article, the Wilshire equation is used to extrapolate …

Texas Sour Orange Juice Used In Scaffolds For Tissue Engineering, Mandana Akia, Nataly Salinas, Cristobal Rodriguez, Robert Gilkerson, Luis A. Materon, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S. aureus and E. coli, respectively. The cell studies revealed a suitable environment for cell growth and cell attachment. The outcome …

4-D Printing Of Pressure Sensors And Energy Harvesting Devices For Engineering Education, Tzu-Liang Bill Tseng, Aditya Akundi, Hoejin Kim

Manufacturing & Industrial Engineering Faculty Publications and Presentations

This paper elaborates on the development of laboratory project modules in the Industrial manufacturing and systems engineering department at The University of Texas El Paso based on Four-Dimensional (4D) printing technology. These modules are aimed at introducing the students to interdisciplinary manufacturing and emerging dimensions in manufacturing technology. 4D printing is a new dimension in additive manufacturing wherein, the 3D printed structures react to the change of parameters within the environment such as temperature, and humidity, resulting in shape change or in functionality such as electricity output, and self-healing. Recently 4D printing of simple devices for pressure sensors application were …

Vibration-Based Defect Detection For Freight Railcar Tapered-Roller Bearings, Joseph Montalvo, Constantine Tarawneh, Arturo A. Fuentes

Mechanical Engineering Faculty Publications and Presentations

The railroad industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the conductor of high risk defects. Many defective bearings may never be detected by TADS™ due to the fact that a high risk defect is considered a spall which spans more than 90% of a bearing’s raceway, and there are less than 20 systems in operation throughout the United States and Canada. Much like the TADS™, the HBD is a device …

Developing And Testing An Electronic Homework System To Improve Student Engagement And Learning In Engineering Thermodynamics, Stephen Crown, Constantine Tarawneh, Jazmin Ley

Mechanical Engineering Faculty Publications and Presentations

An electronic homework delivery system was developed for an advanced undergraduate engineering thermodynamics course due to limitations in available electronic homework systems. A commercially available system was effectively used in the introductory course for simple problems. The complexity of problems in the advanced course made adoption of the same system problematic as students needed feedback in the problem solving process. A system was devised that delivers individual problems to each student, provides feedback throughout the process, and records results for assessment. The system has helped students become more active in homework assignments in both completing assignments and in doing original …

Defect Prognostics Models For Spall Growth In Railroad Bearing Rolling Elements, Nancy De Los Santos, Constantine Tarawneh, Robert E. Jones, Arturo A. Fuentes

Mechanical Engineering Faculty Publications and Presentations

Prevention of railroad bearing failures, which may lead to catastrophic derailments, is a central safety concern. Early detection of railway component defects, specifically bearing spalls, will improve overall system reliability by allowing proactive maintenance cycles rather than costly reactive replacement of failing components. A bearing health monitoring system will provide timely detection of flaws. However, absent a well verified model for defect propagation, detection can only be used to trigger an immediate component replacement. The development of such a model requires that the spall growth process be mapped out by accumulating associated signals generated by various size spalls. The addition …

An Analysis Of The Efficacy Of Wayside Hot-Box Detector Data, Constantine Tarawneh, James Aranda, Veronica Hernandez, Claudia J. Ramirez

Mechanical Engineering Faculty Publications and Presentations

Wayside hot-box detectors (HBDs) are devices that are currently used to monitor bearing, axle, and brake temperatures as a way of assessing railcar component health and to indicate any possible overheating or abnormal operating conditions. Conventional hot-box detectors are set to alarm whenever a bearing is operating at a temperature that is 94.4°C (170°F) above ambient, or when there is a 52.8°C (95°F) temperature difference between two bearings that share an axle. These detectors are placed adjacent to the railway and utilize an infrared sensor in order to obtain temperature measurements. Bearings that trigger HBDs or display temperature trending behavior …

Impact Of Hysteresis Heating Of Railroad Bearing Thermoplastic Elastomer Suspension Pad On Railroad Bearing Thermal Management, Oscar O. Rodriguez, Arturo A. Fuentes, Constantine Tarawneh

Mechanical Engineering Faculty Publications and Presentations

It is a known fact that polymers and all other materials develop hysteresis heating due to the viscoelastic response or internal friction. The hysteresis or phase lag occurs when cyclic loading is applied leading to the dissipation of mechanical energy. The hysteresis heating is induced by the internal heat generation of the material, which occurs at the molecular level as it is being disturbed cyclically. Understanding the hysteresis heating of the railroad bearing elastomer suspension element during operation is essential to predict its dynamic response and structural integrity, as well as to predict the thermal behavior of the railroad bearing …

Development And Optimization Of Alumina Fine Fibers Utilizing A Centrifugal Spinning Process, Mandana Akia, Dulce Capitanachi, Misael E. Martinez, Carlos Hernandez, Hector De Santiago, Yuanbing Mao, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Highlights

• Successful synthesis of AIP/PVA composite fibers using Forcespinning® techniques.

• Optimization of the operating parameters applying response surface methodology (RSM).

• Fabrication of mesostructured gamma alumina and highly crystalline alpha alumina fine fibers.

Abstract

Aluminum isopropoxide and poly(vinylalcohol) fine fibers were successfully fabricated and optimized utilizing the response surface methodology. The optimized composite fibers showed mean fiber diameter of 304 nm. The fiber samples were calcined at different temperatures to attain both gamma and alpha phases of alumina. Various characterization methods including scanning electron microscopy, thermogravimetric analysis, x-ray diffraction and nitrogen adsorption/desorption analysis were conducted. The BET analysis …

The Use Of Fe3o4/Carbon Composite Fibers As Anode Materials In Lithium Ion Batteries, Howard Campos, Jonathan Ayala, Carolina Valdes, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications and Presentations

In the present work, results on the synthesis and mass production of polymer/ceramic composite fibers through Forcespinning® (FS) are reported. Magnetite (Fe3O4), has been considered as a good anode material for Lithium‒Ion Batteries (LIBs) due to its high theoretical capacity (~924 mAhg-1), low cost, and low toxicity. The Fe3O4/carbon composite, in the present study, was achieved through Forcespinning iron (III) acetylacetonate /polyacrylonitrile (PAN) precursor solution with stabilization in air at 280°C followed by carbonization at 600°C under argon. The electrochemical cyclic performance of Fe3O4/C composite fibers was investigated by galvanostatic charge/discharge experiments. The results showed the Fe3O4/C composite fiber anode …

An Implantable Peripheral Nerve Recording And Stimulation System For Experiments On Freely Moving Animal Subjects, Byunghun Lee, Mukhesh K. Koripalli, Yaoyao Jia, Joshua Acosta, M. S. E. Sendi, Yoonsu Choi, Maysam Ghovanloo

Electrical and Computer Engineering Faculty Publications and Presentations

A new study with rat sciatic nerve model for peripheral nerve interfacing is presented using a fully-implanted inductively-powered recording and stimulation system in a wirelessly-powered standard homecage that allows animal subjects move freely within the homecage. The Wireless Implantable Neural Recording and Stimulation (WINeRS) system offers 32-channel peripheral nerve recording and 4-channel current-controlled stimulation capabilities in a 3 × 1.5 × 0.5 cm3 package. A bi-directional data link is established by on-off keying pulse-position modulation (OOK-PPM) in near field for narrow-band downlink and 433 MHz OOK for wideband uplink. An external wideband receiver is designed by adopting a commercial software …

Value Engineering And Its Applications In Civil Engineering, Mohamed Abdel-Raheem, Victoria Burbach, Ahmed Abdelhameed, Grecia Silva Sanchez, Linda Navarro

Civil Engineering Faculty Publications and Presentations

Value engineering (VE) can be a very valuable tool in the field of civil engineering and the construction industry. VE has tremendous benefits in both cost-saving and project improvement areas. Between the pay-offs and wide variety of applications, it is unsurprising that more firms are adopting the principles of VE in the design and construction phases of their projects. Many studies have been conducted on the invention of new tools for VE while others focused on the application aspect of VE in different engineering domains. This paper presents an overview of VE and its applications in the field of civil …

Review: Electric Field Driven Pumping In Microfluidic Device, Mohammad R. Hossan, Diganta Dutta, Nazmul Islam, Prashanta Dutta

Electrical and Computer Engineering Faculty Publications and Presentations

Pumping of fluids with precise control is one of the key components in a microfluidic device. The electric field has been used as one of the most popular and efficient nonmechanical pumping mechanism to transport fluids in microchannels from the very early stage of microfluidic technology development. This review presents fundamental physics and theories of the different microscale phenomena that arise due to the application of an electric field in fluids, which can be applied for pumping of fluids in microdevices. Specific mechanisms considered in this report are electroosmosis, AC electroosmosis, AC electrothermal, induced charge electroosmosis, traveling wave dielectrophoresis, and …

A Framework For Assessing The Economic Feasibility Of Leed For Homes Guidelines For Water Efficiency, Mohamed Abdel-Raheem, Jennifer Lima

Civil Engineering Faculty Publications and Presentations

Sustainable practices have been on the rise during the last decade. From recycling to alternative energy sources, many studies have been conducted to incorporate green practices into people’s daily lives. However, cost efficiency can be a significant deterrent to begin or continue these practices. Homes are responsible for the consumption of a large portion of water in the United States. As such there is a need for more studies directed toward the assessment of the practical implementation of water efficiency. This study follows LEED v4 for homes guidelines to examine the feasibility of adopting green practices for water reduction. The …

Functionalized Graphene Oxide As Reinforcement In Epoxy Based Nanocomposites, F. V. Ferreira, F. S. Brito, W. Franceschi, E. A. N. Simonetti, L. .S Cividanes, Mircea Chipara, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

The effects of amine-modified graphene oxide on dispersion and micro-hardness of epoxy based nanocomposites are reported. Graphene oxide was prepared by the modified Hummers method followed by hexamethylenediamine functionalization. Analysis conducted through Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy-based infrared spectroscopy show that the functionalization process effectively promoted a replacement of oxygen with amine groups while simultaneously creating defects in the graphitic structure. An increase in hardness was observed for the developed nanocomposites.

Modeling Of Aggregation And Gelation Of Nanoparticles Using Quadrature Method Of Moments, Elsayed Abdelfatah, Maysam Pournik

Mechanical Engineering Faculty Publications and Presentations

Applications of Nanotechnology are growing significantly in the petroleum industry such as oil recovery, and well stimulation. In aqueous media, silica nanoparticles aggregate if there is sufficient attractive energy between nanoparticles. Aggregate size distribution evolves as aggregation continues, and once it spans the space, it forms a gel. The objective of this study is to study the aggregation and gelation kinetics in the batch. Population Balance equation (PBE) is used to model the kinetics of aggregation. Quadrature method of moments (QMOM) is used to convert the PBE with continuous distribution of nanoparticle size into a set of moment equations for …

Direct Numerical Simulation Of Transverse Ripples: 1. Pattern Initiation And Bedform Interactions, ‪Nadim Zgheib, J. J. Fedele, D. C. J. D. Hoyal, M. M. Perillo, S. Balachandar

Mechanical Engineering Faculty Publications and Presentations

We present results of coupled direct numerical simulations between flow and a deformable bed in a horizontally periodic, turbulent open channel at a shear Reynolds number of Reτ = 180. The feedback between the temporally and spatially evolving bed and the flow is enforced via the immersed boundary method. Using the near-bed flow field, we provide evidence on the role of locally intense near-bed vortical structures during the early stages of bed formation, from the emergence of quasi-streamwise streaks to the formation of incipient bedform crestlines. Additionally, we take a new look at a number of defect-related bedform interactions, …

Direct Numerical Simulation Of Transverse Ripples: 2. Self-Similarity, Bedform Coarsening, And Effect Of Neighboring Structures, ‪Nadim Zgheib, J. J. Fedele, D. C. J. D. Hoyal, M. M. Perillo, S. Balachandar

Mechanical Engineering Faculty Publications and Presentations

Coupled bed-flow direct numerical simulations investigating the early stages of pattern formation and bedform (ripple) interactions were examined in a previous paper (Part 1), making use of the resolved flow field. In this paper (Part 2), we compare our results to published experimental data and provide an extensive quantitative analysis of the bed using spectral analysis and two-point correlations. The effect of the mobile rippled bed on the flow structure and turbulence is investigated locally (at specific streamwise locations) and over the entire computational domain. We show that developing ripples attain a self-similar profile in both the shape and the …

High-Throughput Production With Improved Functionality And Graphitization Of Carbon Fine Fibers Developed From Sodium Chloride-Polyacrylonitrile Precursors, Mandana Akia, Lee Cremar, Manuel Seas, Jahaziel Villarreal, Alejandra Valdez, Mataz Alcoutlabi, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Fine polyacrylonitrile (PAN) fibers were produced through a scalable centrifugal spinning process. Sodium chloride (NaCl) was added to the PAN-dimethylformamide solution to decrease the surface tension and consequently promote a decrease in fiber diameter while increasing the fiber output. The fiber preparation process involved the centrifugal spinning of the PAN-based solution; developed fibers were stabilized in air at 240°C followed by carbonization at 800°C under a Nitrogen atmosphere. The addition of sodium chloride to the PAN solution led to a 37% decrease in the carbon fiber diameter. The carbon fibers were analyzed by scanning electron microcopy, transmission electron microscopy (TEM), …

High-Throughput Production With Improved Functionality And Graphitization Of Carbon Fine Fibers Developed From Sodium Chloride-Polyacrylonitrile Precursors, Mandana Akia, Lee Cremar, Manuel Seas, Jahaziel Villarreal, Mataz Alcoutlabi, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Fine polyacrylonitrile (PAN) fibers were produced through a scalable centrifugal spinning process. Sodium chloride (NaCl) was added to the PAN-dimethylformamide solution to decrease the surface tension and consequently promote a decrease in fiber diameter while increasing the fiber output. The fiber preparation process involved the centrifugal spinning of the PAN-based solution; developed fibers were stabilized in air at 240°C followed by carbonization at 800°C under a Nitrogen atmosphere. The addition of sodium chloride to the PAN solution led to a 37% decrease in the carbon fiber diameter. The carbon fibers were analyzed by scanning electron microcopy, transmission electron microscopy (TEM), …

Construction Methods Used For Controlling Temperature In Mass Concrete Structures, Mohamed Abdel-Raheem, Ofsman Quintana, Melissa Morales, Yahaira Marroquin-Villa, Dalinda Ramos, Sylvia Hernandez

Civil Engineering Faculty Publications and Presentations

The hydration of cement can release a substantial amount of heat that can be problematic in mass concrete structure. This heat of hydration (HH) can produce thermal stresses that can crack the concrete and compromise the integrity of the structure leading to its failure. Throughout the years, different methods have been developed in order to mitigate the negative effects of the HH on mass concrete structures. This study presents a comprehensive review of the previous methods documented in the literature that have been utilized in controlling the temperature rise due to the HH in mass concreting. The reviewed methods were …

A Two-Dimensional Finite Element Model Of The Grain Boundary Based On Thermo-Mechanical Strain Gradient Plasticity, Yooseob Song, George Z. Voyiadjis

Civil Engineering Faculty Publications and Presentations

In this work, a two-dimensional finite element model for the grain boundary flow rule is developed based on the thermo-mechanical gradient-enhanced plasticity theory. The proposed model is temperature-dependent. A special attention is given to physical and micromechanical nature of dislocation interactions in combination with thermal activation on stored and dissipated energy. Thermodynamic conjugate microforces are decomposed into energetic and dissipative components. Correspondingly, two different grain boundary material length scales are present in the proposed model. Finally, numerical examples are solved in order to explore characteristics of the proposed grain boundary flow rule.

Probabilistic Analysis And Resistance Factor Calibration For Deep Foundation Design Using Monte Carlo Simulation, Thuy Vu, Erik Loehr, Douglas Smith

Civil Engineering Faculty Publications and Presentations

The method of incorporating the sources of parameter uncertainty is crucial when conducting probabilistic analysis for service limit state (SLS) design of a deep foundation. This paper describes the method of using Monte Carlo simulation for probabilistic analyses and for calibration of resistance factors of drilled shafts at SLS. The paper presents discussions on the finding of an impossible case, where the different combinations of load, variability of soil strength and target probability of failure made it impossible to calibrate the SLS resistance factors. Resistance factors for drilled shafts in shale are introduced, and were found to be responsive to …

Initial Investigation Of Generating Electricity From Concrete, Mohamed Abdel-Raheem, Ofsman Quintana

Civil Engineering Faculty Publications and Presentations

Cement heat of hydration (HH) can be problematic especially in mass concrete structures as it causes thermal stresses that can lead to failure. Previous and current research has focused on minimizing the HH and mitigating its effects. The methods currently used for treating the HH in mass concreting varies between using: adding supplementary material to concrete, precooling of aggregates and mixing water, post-cooling of concrete, insulation of concrete members, and placement of concrete in thin lifts. These methods result in adding more cost and time to the construction project. This research sheds the light on a new approach in treating …

Responsiveness Comparison Between A Lift-Type And Drag-Type Rotor In Waves, Yingchen Yang, Fredrick A. Jenet, Deyanira Jimenez, Brandon Benavides, Jesus Cerda, Angel Lopez

Mechanical Engineering Faculty Publications and Presentations

Our recent progress on development of a vertical-axis unidirectional rotary wave energy converter (WEC) is discussed in this work. The WEC features a vertical-axis rotor that preforms unidirectional rotation in waves. The vertical axis arrangement makes the WEC respond well to waves from any direction with no realignment needs. And, the unidirectional behavior of the rotor promises no wave frequency discrimination, which is in comparison to reciprocating WECs that employ the resonant principle and are very frequency-specific. In our earlier proof-of-concept studies, we have successfully demonstrated two types of rotor designs: a lift type employing hydrofoil blades and a drag …

Development Of Antimicrobial Chitosan Based Nanofiber Dressings For Wound Healing Applications, Lee Cremar, Jorge Gutierrez, Jennifer Martinez, Luis A. Materon, Robert Gilkerson, Fenghua Xu, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Objective(s): Chitosan based composite fine fibers were successfully produced via a centrifugal spinning technology. This study evaluates the ability of the composites to function as scaffolds for cell growth while maintaining an antibacterial activity.

Materials and Methods: Two sets of chitosan fiber composites were prepared, one filled with anti-microbial silver nanoparticles and another one with cinnamaldeyhde. Chitosan powder was dissolved in trifluoroacetic acid and dichloromethane followed by addition of the fillers. The fiber output was optimized by configuring the polymer weight concentration (7, 8, and 9 w/w% chitosan) and applied angular velocity (6000-9000 RPM) within the spinning process.

Results: …