Engineering Commons^™

Improvement Of Light Intensity And Efficiency Of N-Zno/Nio/P-Gan Heterojunction-Based White Light Emitting Diodes Using Micro-/Nanolens Array, Apurba Adhikary, Md Shamim Ahsan, Md Mahbub Hossain, Md Bipul Hossain, S. H. Shah Newaz, Farid Ahmed, Ik-Bu Sohn

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Our study proposes a technique to enhance light extraction efficiency of light emitting diodes (LEDs) by incorporating various micro-/nanolens arrays (MNLAs) on the substrate layer, which in turn increases the external quantum efficiency (EQE) of the LEDs. To simulate the LEDs, we utilized the finite difference time domain method. To achieve a white LED, we inserted a thin layer of NiO at the interface between the n-type ZnO and the p-type GaN. The basic n-ZnO/NiO/p-GaN heterojunction-based LED exhibited an EQE of 10.99% where the effective refractive index of the LED structure was 1.48. The EQE was further increased by engraving …

Grow Local Manufacturing Along Us/Mexico Border Region For An Integrated Supply Chain In The Post Covid-19 Era, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The current coronavirus disease pandemic, plus the strong movement of manufacturing reshoring, provide a unique opportunity for many US regions to grow local manufacturers. This technical note attempts to review the current situation and trend in US manufacturing. We then discuss challenges and necessary steps, such as asset mapping, required to grow local suppliers. Suggestions are then made to support growing local suppliers along the US/Mexico border region.

Centrifugally Spun Mats Based On Biopolyesters/Hydroxyapatite And Their Potential As Bone Scaffolds, Victoria Padilla-Gainza, Heriberto Rodríguez-Tobías, Graciela Morales, Eduardo Saucedo, Karen Lozano, Vanessa Montaño-Machado,, Diego Mantovani

Mechanical Engineering Faculty Publications and Presentations

This work studied the potential of centrifugal spinning for the production of fibrous materials based on poly(D,L-lactic acid) (PDLLA) and poly(3-hydroxybutyrate) (PHB) with hydroxyapatite nanoparticles (n-Hap). The influence of n-Hap concentration (5, 10, and 15 wt.%) and spinneret angular speed on the final fiber morphology were analyzed. Further experimental evaluations were implemented to determine the effect of n-Hap on the thermal and mechanical performance. The optimum parameters that show a balance among high yield production of homogeneous fibers with the smallest fiber average diameter were found to be at 5 wt.% of n-Hap processed at 7000 rpm for PDLLA, and …

Characterization And Performance Of Minimum Quantity Lubricants In Through-Tool Drilling, Amla Patil, Jay Raval, Tim Bangma, Immanuel Edinbarough, Bruce Tai, David Stephenson, Suleiman Obeidat, Wayne Nguyen Hung

Manufacturing & Industrial Engineering Faculty Publications and Presentations

This study characterized airborne microdroplet diameters and size distribution from two commercially available lubricants A and B for internal minimum quantity lubrication (MQL). The effects of air pressure, oil channel size, physical properties of lubricants on the resultant microdroplets and through-tool MQL drilling performance were studied. Airborne microdroplet diameters were highly sensitive to the coolant channel sizes and air pressure. Cluster method was used to divide microdroplets into smaller clusters for comparison. Experimental data show that the average airborne microdroplet of lubricant B was larger than that of lubricant A at different air pressures and channel sizes. The contact angle …

Effect Of Additional Weight On Human Squat Exercise Stability: Ground Reaction Forces And Centers Of Pressure, Jose Galarza, Dumitru Carantu

Mechanical Engineering Faculty Publications and Presentations

The main focus of this work is to investigate the effect of weight on the stability of human squat exercise. The squat exercise is a common daily activity. Experiments are conducted using one human subject. A VICON motion analysis system integrated with Force Plates is utilized for these experiments. An experimental protocol is developed and followed. This work analyzes the time series of the normal component of the ground reaction forces and each coordinate of the center of pressure. These time series are used to estimate the Lyapunov Exponents using Rosenstein method. MATLAB software package is used for this investigation. …

Design And Validation Of A Portable Handheld Device To Produce Fine Fibers Using Centrifugal Forces, Gregory Potter, Raul Barbosa, Alexa Villarreal, Alexandra Salinas, Hector Guzman, Heriberto De Leon, Javier A. Ortega, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

In the present research project, a novel portable battery-powered handheld device able to produce micron and submicron fibers using centrifugal forces is proposed. The design includes spinnerets with a clamshell configuration with multiple chambers or reservoirs (2, 4, and 8) and different exit orifice diameters (400, 500, 600, and 800 µm). The rotational speed is controlled via an Arduino microcontroller. To validate the design, a series of experiments were conducted and the effect of the orifice diameter, number of chambers, and velocity on the resulting fibers’ diameter and yield was studied. For the experiments, a polymeric solution of Polyvinyl Alcohol …

Application Of Optimized Laser Surface Re-Melting Process On Selective Laser Melted 316l Stainless Steel Inclined Parts, Jafar Ghorbani, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Lower surface quality of selective laser melting (SLM) manufactured parts remains to be a key shortcoming particularly for high performance functional components. In this paper, the authors utilized Box–Behnken methodology to explore the effect of laser surface re-melting process parameters. The process parameters are:laser power, laser exposure time, laser point distance, and shell layer thickness. The experiments were conducted using Renishaw AM-250 machine. SLM manufactured parts with inclination of 45˚ up-skin were treated with a given surface roughness using laser surface re-melting (LSR). The optimization of process parameters was conducted using response surface methodology and the validation tests was carried …

Optimizing Power Consumption Of Freight Railroad Bearings Using Laboratory Experimental Data, Carlos E. Lopez Iii, Constantine Tarawneh, Arturo A. Fuentes, Harry Siegal

Mechanical Engineering Faculty Publications and Presentations

Based on projected freight truck fuel efficiency, freight railroad and equipment suppliers need to identify, evaluate and implement technologies and/or operating practices to maintain traditional railroad economic competitiveness. The railway industry uses systems that record the total energy efficiency of a train but not energy efficiency or consumption by components. Lowering the energy consumption of certain train components will result in an increase in its overall energy efficiency, which will yield cost benefits for all the stakeholders. One component of interest is the railroad bearing whose power consumption varies depending on several factors that include railcar load, train speed, condition …

Estimating The Inner Ring Defect Size And Residual Service Life Of Freight Railcar Bearings Using Vibration Signatures, Jennifer Lima, Constantine Tarawneh, Jesse Aguilera, Jonas Cuanang

Mechanical Engineering Faculty Publications and Presentations

There are currently two primary wayside detection systems for monitoring the health of freight railcar bearings in the railroad industry: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the train operator of high-risk defects. However, many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans about 90% of a bearing’s raceway, and there are less than 30 systems in operation throughout the United States and Canada. HBDs sit on the side of the rail-tracks and use non-contact infrared sensors to …

Optimization Of Railroad Bearing Health Monitoring System For Wireless Utilization, Jonas Cuanang, Constantine Tarawneh, Martin Amaro Jr., Jennifer Lima, Heinrich D. Foltz

Mechanical Engineering Faculty Publications and Presentations

In the railroad industry, systematic health inspections of freight railcar bearings are required. Bearings are subjected to high loads and run at high speeds, so over time the bearings may develop a defect that can potentially cause a derailment if left in service operation. Current bearing condition monitoring systems include Hot-Box Detectors (HBDs) and Trackside Acoustic Detection Systems (TADS™). The commonly used HBDs use non-contact infrared sensors to detect abnormal temperatures of bearings as they pass over the detector. Bearing temperatures that are about 94°C above ambient conditions will trigger an alarm indicating that the bearing must be removed from …

Casimir Effect On Amplitude-Frequency Response Of Parametric Resonance Of Electrostatically Actuated Nems Cantilever Resonators, Dumitru Caruntu, Christian A. Reyes

Mechanical Engineering Faculty Publications and Presentations

This paper deals with the effect of Casimir force on the amplitudefrequency response of parametric resonance of electrostatically actuated nanoresonators. The resonator is actuated by using an electrostatic force to include a f irst order fringe correction. Casimir force and viscous damping force are included in the model, as well. Both electrostatic and Casimir forces are nonlinear. The behavior of the resonator is investigated using two methods, the Method of Multiple Scales (MMS) for a Reduced Order Model (ROM) using one mode of vibration, and numerical integration of ROMs using up to five modes of vibration. ROM is based on …

Processing-Structure-Property Relationships Of Biopolyester/Zinc Oxide Fibrous Scaffolds Engineered By Centrifugal Spinning, Victoria Padilla-Gainza, Heriberto Rodríguez-Tobías, Graciela Morales, Antonio Ledezma-Pérez, Carmen Alvarado-Canché, Cristobal Rodriguez, Robert Gilkerson, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

This study addresses the processing of nonwoven fibrous materials obtained by centrifugal spinning method, namely Forcespinning; a high yield and low production cost technique little explored in this field. Poly(D, L-lactic acid) (PDLLA) and poly(3-hydroxybutyrate) (PHB) were used as matrices and reinforced with zinc oxide nanoparticles (n-ZnO). The morphology, mechanical, and thermal performance of the developed composites were analyzed as well as the antibacterial effect of n-ZnO. Fibrous materials with n-ZnO concentrations of 1, 3, and 5 wt. % for PDLLA and 1 and 3 wt. % for PHB were evaluated. The results showed that the incorporation of n-ZnO produces …

Embedding Computer Simulation Based Classroom Activities To Enhance The Learning Experience For Manufacturing Systems, Tzu-Liang Bill Tseng, Md Fashiar Rahman, Richard Chiou, Ivan Arturo Renteria-Marquez, Aditya Akundi, Amit J. Lopes, Jeevarathinam Senthilkumar

Manufacturing & Industrial Engineering Faculty Publications and Presentations

In recent time, manufacturing environment are bracing higher end technologies to achieve high productivity, efficiency and effectiveness. Due to the adoption of the sophisticated technologies, the system is becoming very complex and stochastic. Moreover, the manufacturing system is interconnected among its different subsystems and components, which cannot be described only through the theoretical explanation. Here, computer simulation can be integrated to design and visualize the stochastic and complex system. This paper uses the advantage of simulation to describe a series classroom activity using SIMIO software, which are deployed in industrial systems simulation course in the University of Texas at El …

Privileging Learning Over Numbers: Developing An Alternative Student Assessment In Engineering, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

In this research study, a new model to assess student performance and academic learning in engineering disciplines is proposed with the intention of shifting a grade driven mentality into a learning-oriented mindset. The rational for this model of assessment is to disrupt normalized assessment practices in higher education, reframe student thinking regarding learning and acquisition of knowledge, and encourage students to engage in coursework in meaningful ways. Unfortunately, grades in higher education have become a primary focal point for many students as a means to secure internship opportunities, undergraduate research, post-graduation employment, and graduate school acceptance into desired institutions. The …

Thermal Conductivity Performance Of 2d Hbn/Mos 2/Hybrid Nanostructures Used On Natural And Synthetic Esters, Jaime Taha-Tijerina, Hélio Ribeiro, Karla Aviña, Juan Manuel Martínez, Anna Paula Godoy, Josué Marciano De Oliveira Cremonezzi, Milene Adriane Luciano, Marcos Antônio Gimenes Benega, Ricardo Jorge Espanhol Andrade, Guilhermino José Macedo Fechine

Manufacturing & Industrial Engineering Faculty Publications and Presentations

In this paper, the thermal conductivity behavior of synthetic and natural esters reinforced with 2D nanostructures-single hexagonal boron nitride (h-BN), single molybdenum disulfide (MoS2), and hybrid h-BN/MOS2-were studied and compared to each other. As a basis for the synthesis of nanofluids, three biodegradable insulating lubricants were used: FR3TM and VG-100 were used as natural esters and MIDEL 7131 as a synthetic ester. Two-dimensional nanosheets of h-BN, MoS2, and their hybrid nanofillers (50/50 ratio percent) were incorporated into matrix lubricants without surfactants or additives. Nanofluids were prepared at 0.01, 0.05, 0.10, 0.15, and 0.25 weight percent of filler fraction. The experimental …

Structuring Student Success: Incorporating A Genre-Based Pedagogical Method To Improve A Strength Of Materials Laboratory Manual, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

In this research study the authors incorporated a pedagogical technique to improve a strength of materials lab manual. The conceptualization and subsequent development of a student friendly lab manual resource emerged from students’ difficulty in understanding the following areas: introduction to experiment, procedures, calculations, and relevancy to class content. Based on a survey conducted before lab manual improvements and modifications, mechanical engineering students expressed high dissatisfaction with the written structure of the manual and felt they spent too much time understanding lab procedures, deciphering what equations to utilize to complete their analyzes, and completing the report. As such, the authors …

Smart Environments For Assisted Living: A Multidisciplinary Collaboration In Engineering And Architecture Education, Adriana Rios-Santiago, Anabel Pineda-Briseno, Jesus A. Gonzalez-Rodriguez, Uriel Saul Huerta

Manufacturing & Industrial Engineering Faculty Publications and Presentations

This paper presents a description of a collaborative project based on the integration of technology development in the built environment for assisted living. The multidisciplinary collaboration is developed as a cooperative commitment to provide support for cross-border, collective projects. It was initiated as a project-based learning setting between undergraduate engineering students, and four years later the program shifted to include undergraduate architecture students and engineering master’s students. The learning experience opens the gate to a completely new collaborative setting, yet to be established, independent from its predecessor setting of project-based learning, focusing now towards an interdisciplinarity setting in cross-border collaboration. …

Rapid Manufacturing Of Critical Industrial Parts: A Method Based On Reverse Engineering, Rapid Prototyping, And Coordinate Metrology, Immanuel Edinbarough, Aditya Akundi

Manufacturing & Industrial Engineering Faculty Publications and Presentations

This paper presents a method of rapidly manufacturing industrial parts that are critical to the production. In order to assist the Advanced Manufacturing industry, a senior project team at the University of Texas Rio Grande Valley (UTRGV) applied Rapid Manufacturing (RM) to manufacture or fabricate critical machine parts used to maintain production machines. Failures of parts and tools in industrial settings cost money and hurt output. Usually, the problem arises when the tooling being used is one of a kind and repair or replacements come with long leadtimes. Other problems are encountered when original part or tool engineering drawing is …

Text Mining-Based Qualitative Student Assessment Of Interactive Simulation Learning Using Simio Tool – A Work In Progress, Aditya Akundi, Immanuel Edinbarough

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Computer simulations complement and extend the real-world components of industries and manufacturing organizations. Teaching simulation-based tools helps students in modeling and analyzing the behavior of real time systems. With the increased demand observed in products and technology consumption, manufacturing industries are evolving to embrace new technologies and initiatives. To keep the emerging workforce technically competent in current tools to understand and interpret manufacturing processes, this paper portrays an effort by the authors in introducing SIMIO i.e. a tool on Simulation of intelligent objects to undergraduate students at University of Texas Rio Grande Valley and in understanding the influence of using …

Expanding Engineering And Technology Opportunities To Students In The Border Region Through International Collaboration, Jesus A. Gonzalez-Rodriguez, Immanuel Edinbarough, Adriana Rios-Santiago, Anabel Pineda-Briseno

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Expanding Engineering and Technology Opportunities to Students in the Border Region through International Collaboration

For some years now, our Department of Engineering Technology of the XXXX, has collaborated with Universities across the southern border to carry out different activities such as undergraduate research, collaborative course-based projects, and senior design projects. We have observed how students benefit from being exposed to work in multidisciplinary and multicultural teams.

We now expand this form of work to a higher-level research collaboration where students and faculty from four different institutions participate. Two institutions of higher education in Mexico and a University and a Community …

Finding Balance: Examining The Impact Of Grades On Engineering Students' Well-Being, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

The authors conducted a preliminary research study to understand the emotional and academic impact grades have on engineering undergraduate students. Grades in higher education have become a priority for students to secure internship opportunities, post-graduation employment, and graduate school acceptance. However, students’ desire to attain high grades in engineering disciplines may lead to negative effects such as additional anxiety and increased mental exertion, physical exhaustion, and overall lack of work-life balance. A survey was conducted with a cohort of 45 students to understand their perspective on grades before, during, and at the end of the semester, and their responses to …

Hollow-Core Photonic Crystal Fiber Mach–Zehnder Interferometer For Gas Sensing, Kaveh Nazeri, Farid Ahmed, Vahid Ahsani, Hang-Eun Joe, Colin Bradley, Ehsan Toyserkani, Martin B. G. Jun

Manufacturing & Industrial Engineering Faculty Publications and Presentations

A novel and compact interferometric refractive index (RI) point sensor is developed using hollow-core photonic crystal fiber (HC-PCF) and experimentally demonstrated for high sensitivity detection and measurement of pure gases. To construct the device, the sensing element fiber (HC-PCF) was placed between two single-mode fibers with airgaps at each side. Great measurement repeatability was shown in the cyclic test for the detection of various gases. The RI sensitivity of 4629 nm/RIU was demonstrated in the RI range of 1.0000347–1.000436 for the sensor with an HC-PCF length of 3.3 mm. The sensitivity of the proposed Mach–Zehnder interferometer (MZI) sensor increases when …

The Use Of Succinonitrile As An Electrolyte Additive For Composite-Fiber Membranes In Lithium-Ion Batteries, Jahaziel Villarreal, Roberto Orrostieta Chavez, Sujay A. Chopade, Timothy P. Lodge, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications and Presentations

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO₂ cathode and a SnO₂/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE …

Tribological And Thermal Transport Of Ag-Vegetable Nanofluids Prepared By Laser Ablation, Jaime Taha-Tijerina, Sadasivan Shaji, Sreed Sharma Kanakkillam, Maria Isabel Mendivil Palma, Karla Aviña

Informatics and Engineering Systems Faculty Publications and Presentations

Lubricants and fluids are critical for metal-mechanic manufacturing operations as they reduce the friction and wear of tooling and components, and serve as coolants to dissipate the heat generated in these operations. The proper application of these materials improves machine operative life and tooling, and decreases cost, energy, and time consumption for maintenance, damage, repairs, or the need to exchange pieces/components within the machinery. Natural or vegetable-based lubricants have emerged as a substitute for mineral oils, which harm the environment due to their low biodegradability and have negative effects on human health (e.g., causing skin/respiratory diseases). Thus, finding biocompatible and …

Hybrid Phase-Change Lattice Boltzmann Simulation Of Vapor Condensation On Vertical Subcooled Walls, Wandong Zhao, Yuan Gao, Ruijie Li, Songgang Qiu, Yin Zhang, Ben Xu

Mechanical Engineering Faculty Publications and Presentations

Saturated vapor condensation on homogenous and heterogeneous subcooled walls is presented in this study by adopting a hybrid phase-change multiple-relaxation-time Lattice Boltzmann model. The effects of wall wettability on the condensation process, including droplets’ growth, coalescence and falling, and the influence of vapor flow to condensation are investigated. The results demonstrate that the heat fluxes around the triple-phase contact lines are higher than that in other cold areas in homogeneous subcooled walls, which actually indicates the fact that filmwise condensation is preventing the continuous condensation process. Furthermore, the dropwise condensation can be formed more easily on the heterogeneous surface with …

On The Spreading Of Non-Canonical Thermals From Direct Numerical Simulations, Kai Liu, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications and Presentations

We present results from direct numerical simulations on laminar and turbulent non-canonical thermals with an initial rectangular density distribution at a Reynolds number of Re = 500 and Re = 5000, respectively. We find the non-canonical shape to induce strong azimuthal variations in the thermal for both the laminar and turbulent cases. These include noticeable differences in downward and horizontal propagation speeds as well as differences in the strength of the vortex tube. These differences persist over a significant period of time and help generate a cross-flow component that is otherwise not present in canonical cases. The cross-flow component is …

Experimental Study On Plugging Behavior Of Degradable Fibers And Particulates Within Acid-Etched Fracture, Lufeng Zhang, Fujian Zhou, Wei Feng, Maysam Pournik, Zhun Li, Xiuhui Li

Mechanical Engineering Faculty Publications and Presentations

As proven from field practices in North America and Northwest China, temporary plugging and diverting acid fracturing is an indispensable technology to enhance stimulation effect and hydrocarbon production of complex carbonate reservoirs. It's well-known that the key to the success of this technology lies in creating a temporary plugging within the previously created fractures. Consequently, many scholars have conducted laboratory experiments to investigate the plugging behavior of fibers and particulates. However, the current devices nearly have certain limitations in simulating temporary plugging experiments. Aiming at this problem, this paper introduced the fracture temporary plugging evaluation system with large fracture size, …

The Performance Of Sio2 And Tio2 Nanoparticles As Lubricant Additives In Sunflower Oil, Vicente Cortes, Karen Sanchez, Mataz Alcoutlabi, Javier A. Ortega

Mechanical Engineering Faculty Publications and Presentations

In recent years, there has been growing concern regarding the use of petroleum-based lubricants. This concern has generated interest in readily biodegradable fluids such as vegetable oils. The present work evaluated the rheological and tribological characteristics of sunflower oil modified with silicon dioxide (SiO2) and titanium dioxide (TiO2) nanoparticles as lubricant additives at different concentrations. A parallel plate rheometer was used to evaluate the eects of concentration and shear rate on the shear viscosity, and the experimental data was compared with conventional models. The wear protection and friction characteristics of the oil-formulations were evaluated by conducting block-on-ring sliding tests. Surface …

Spectroscopic Investigations On Pvdf-Fe2o3 Nanocomposites, Dorina M. Chipara, Victor Kuncser, Karen Lozano, Mataz Alcoutlabi, Elamin Ibrahim, Mircea Chipara

Mechanical Engineering Faculty Publications and Presentations

Polyvinylidene fluoride-iron oxide (PVDF-Fe2O3) nanocomposites have been obtained my melt mixing of PVDF with Fe2O3 nanoparticles. The interactions between the polymeric matrix and the nanofiller have been investigated by wide angle X-ray scattering (WAXS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy, using both red and green excitations (lasers). WAXS, FTIR, and Raman spectra confirm that all samples contain α PVDF as the major crystalline form of the polymeric matrix. Experimental data revealed small changes in the positions of X-ray lines as well as modifications of the width of X-ray lines upon loading by Fe2O3 nanoparticles. FTIR and Raman spectra …