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Full-Text Articles in Engineering

Bio-Inspired Micromachined Volumetric Flow Sensor With A Big Dynamic Range For Intravenous Systems, Lansheng Zhang, Yingchen Yang, Georgios A. Bertos, Chang Liu, Huan Hu Dec 2022

Bio-Inspired Micromachined Volumetric Flow Sensor With A Big Dynamic Range For Intravenous Systems, Lansheng Zhang, Yingchen Yang, Georgios A. Bertos, Chang Liu, Huan Hu

Mechanical Engineering Faculty Publications and Presentations

Real-time monitoring of drug delivery in an intravenous infusion system can prevent injury caused by improper drug doses. As the medicine must be administered into the vein at different rates and doses in different people, an ideal intravenous infusion system requires both a low flow rate and large dynamic range monitoring. In this study, a bio-inspired and micromachined volumetric flow sensor is presented for the biomedical application of an intravenous system. This was realized by integrating two sensing units with different sensitivities on one silicon die to achieve a large dynamic range of the volumetric flow rate. The sensor was …


Fabrication Of Solar Absorber Tube With Internal Fin Structure With In718 And Effect Of Boron With In718 For Solar Absorber Tube Using Selective Laser Melting 3d Printing Technology, Naznin Nuria Afrin Dec 2022

Fabrication Of Solar Absorber Tube With Internal Fin Structure With In718 And Effect Of Boron With In718 For Solar Absorber Tube Using Selective Laser Melting 3d Printing Technology, Naznin Nuria Afrin

Theses and Dissertations

This research aimed to fabricate Solar Absorber Tubes for Solar-Thermal Power Plant with internal fin structures using Selective Laser Melting (SLM) technology. In this study, we investigated the effect of B with IN718 in 3D printing using SLM for solar absorber tubes. The objective was to study the material-process-properties relationship with goal to identify and validate the optimal parameters for the SLM process. Material selected for this study was IN718 with 0.5% and 1% B particle mixed using a V-shape mixing machine. The flowability test was conducted using the Angle of Repose (AOR) method. 3D printed samples …


The Deflection And Heat Transfer Analysis Of Injection Mold Cavity With Sla Cooling Channel Insert, Olumide Temidayo Aladesiun Dec 2022

The Deflection And Heat Transfer Analysis Of Injection Mold Cavity With Sla Cooling Channel Insert, Olumide Temidayo Aladesiun

Theses and Dissertations

Fast cooling in injection molding is the critical in the process economy. Among many different cooling channel designs available, conformal cooling offers the best and the most efficient cooling. However, limited awareness, accessibility, complexity, cost, knowledge, and experience limit the use of conformal cooling channels to be used into the mold in a molding process.

Typically, SLM(Selective Laser Melting) method is used to create cavity inserts with conformal cooling channels, however, due to the difficulties listed above, applications of conformal cooling channels are very limited. For an inexpensive alternative SLA (Stereolithography Apparatus) can print cavity inserts with conformal cooling channels. …


Fabrication And Characterization Of Force Spun Polymeric Nanofiber For Drug Delivery And Tissue Engineering Applications, Salahuddin Ahmed Dec 2022

Fabrication And Characterization Of Force Spun Polymeric Nanofiber For Drug Delivery And Tissue Engineering Applications, Salahuddin Ahmed

Theses and Dissertations

This study focuses on the development and characterization of polymeric nanofiber for drug delivery and tissue engineering applications. In this study, poly(lactic-co-glycolic) acid (PLGA), Poly-vinyl alcohol (PVA), and Pullulan(PL) were used as the base polymers to develop the nanofiber. Bioactive components Oleanolic acid(OA), Oxymatrine(OM), and Salvianolic Acid(SA) were incorporated in PLGA, PVA, and PL, respectively, via solution mixing. The nano fiber systems were developed using the Forcespinning® method. Morphological, thermo-physical, and biological properties of the fiber mats were analyzed. The composite fiber system containing OA showed a very high drug loading efficiency. The composite fiber system containing high concentration of …


Ultrafast Laser Direct Writing Of Conductive Patterns On Modified Polyimide Film For Flexible Electronic Applications, Ishrat Jahan Biswas Dec 2022

Ultrafast Laser Direct Writing Of Conductive Patterns On Modified Polyimide Film For Flexible Electronic Applications, Ishrat Jahan Biswas

Theses and Dissertations

Conductive patterns can be printed on a flexible polymer substrate using the direct laser writing (DLW) method. In order to write conductive circuits in such polymer using a laser, polyimide (PI) is a desirable material choice due to its electrical, chemical, and mechanical properties. Electrically non-conductive PI has shown great potential for flexible printed electronics as LDW enables selective carbonization in the bulk of such material leading to the formation of conductive lines. The technique is shown to be a rapid and minimal cost method for printing electrodes to nanoscale devices. However, investigations in this field show several limitations to …


A Study Of The Surface Properties Of Additive Manufactured Inconel 718 After Laser Surface Treatment And Cnc Grinding, Sampson K. Canacoo Dec 2022

A Study Of The Surface Properties Of Additive Manufactured Inconel 718 After Laser Surface Treatment And Cnc Grinding, Sampson K. Canacoo

Theses and Dissertations

This study investigated the surface properties of additive manufactured Inconel 718 produced through selective laser melting, and the effects of laser ablation and CNC grinding on the surface finish. The objectives were to investigate the effects of the various parameters of laser ablation and CNC grinding on the Inconel 718 surface. The parameters used for the laser experiments were pulse energy (4, 20, and 30 µJ), scanning speed (5, 10, and 15 mm/s), and hatch distance (10, 30, and 50 µm). For the grinding experiments, the wheel speed was kept constant at 20.3 m/sec, however, two different workpiece speed (8.6 …


A Numerical Simulation Of The Powder Bed Additive Manufacturing Process With Molecular Dynamics Simulation, Yeasir Mohammad Akib Dec 2022

A Numerical Simulation Of The Powder Bed Additive Manufacturing Process With Molecular Dynamics Simulation, Yeasir Mohammad Akib

Theses and Dissertations

Many manufacturing industries utilize powder bed fusion (PBF) since it can produce microscale precision 3D parts. During PBF, powder particles are selectively fused layer by layer using thermal energy. The build quality in the PBF process relies heavily on powder bed properties and thermal energy deposition. Powder flowability, spreadability, and packing fraction are some of the insightful factors that determine the quality of the powder bed. In this study, a two-dimensional powder bed is developed using the LAMMPS package. A cloud-based pouring of powders with varying volumes and initialization is adopted for the work. A blade-type and circular recoater is …


Investigation Of Process Parameters To Fabricate Refractory Medium-Entropy Alloy By Selective Laser Melting Process, Abdullah Al Masum Jabir Dec 2022

Investigation Of Process Parameters To Fabricate Refractory Medium-Entropy Alloy By Selective Laser Melting Process, Abdullah Al Masum Jabir

Theses and Dissertations

This thesis proposal investigates the synthesis of TiWMo refractory medium entropy alloy (RMEA) by selective laser melting process from elemental powder. Steel, titanium and tungsten substrates were used to study the impact on the formation of TiWMo RMEA. Different process parameters were applied to investigate the effects on melting, diffusion and formation of RMEA. The microstructure of TiWMo and elemental distribution were observed by scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). SEM analysis revealed that with higher energy density the pores and microcracks were improved. EDS data validated the composition is homogenized and stable after few layers …


Development Of Vegetable Oil-Based Nano-Lubricants Using Ag, H-Bn And Mgo Nanoparticles As Lubricant Additives, Kollol Sarker Jogesh Dec 2022

Development Of Vegetable Oil-Based Nano-Lubricants Using Ag, H-Bn And Mgo Nanoparticles As Lubricant Additives, Kollol Sarker Jogesh

Theses and Dissertations

Because of the harmful impact of petroleum-based lubricant on the environment and human body, vegetable oil-based lubricant with eco-friendly nanoparticles has a great potential to be an alternative lubricant if it possesses proper lubricating properties. In this study, thermal conductivity, viscosity and tribological properties (wear scar diameter and coefficient of friction) of vegetable oil-based nanolubricant, developed from soybean oil and sunflower oil, modified with Ag, h-BN and MgO nanoparticles as lubricant additives, were evaluated. For thermal conductivity evaluation, a line heat source method was used with KD2 Pro-Thermal Property Analyzer. For viscosity evaluation, Haake Mars 40-rheometer was used to evaluate …


Femtosecond Pulse Filamentation In Dielectric Media Toward Photonics Sensor Fabrication, Anitha Narayanan Dec 2022

Femtosecond Pulse Filamentation In Dielectric Media Toward Photonics Sensor Fabrication, Anitha Narayanan

Theses and Dissertations

Through pulse filamentation, femtosecond laser pulses have been utilized to modify the refractive indices of dielectric materials such as glass, A-plane sapphire crystal, and Cplane sapphire crystal. The 10x Infinity Corrected Lens was used, and the focusing condition was tuned as being the same and fixed to both glass and sapphire crystals. First, 8uJ of laser energy was optimized to produce controlled pulse filamentation voids in the glass. The laser intensity was then optimized to 2-3.5 uJ, 1.5 uJ, & 2.5 uJ, respectively, for the controlled pulse filamentation in A and C plane sapphire crystals. Due to the different crystal …


Development Of An Electro-Centrifugal Spinning Setup For Nanofiber Production Research, David A. Treviño Dec 2022

Development Of An Electro-Centrifugal Spinning Setup For Nanofiber Production Research, David A. Treviño

Theses and Dissertations

Nanofiber production methods have been developed and improved over the course of decades. Each process allows for the creation of fibers with distinct properties that provide benefits to growing number of applications. On the same note, every process has shortcomings that keep them from being universally valid for all applications. This research considers electrospinning and centrifugal spinning systems and attempts to create a process which maintains high fiber qualities like small and consistent fiber diameters, and improved fiber alignment while providing a high fiber yield. The electro-centrifugal (EC) spinning machine that resulted was designed utilizing computer aided design (CAD) software …


Feasibility Analysis Of Embedding Optical Fiber Sensor Into Additively Manufactured Part, Mahmudul Hasan Porag Dec 2022

Feasibility Analysis Of Embedding Optical Fiber Sensor Into Additively Manufactured Part, Mahmudul Hasan Porag

Theses and Dissertations

The research tried to examine the viability of the embedment of optical fiber sensors in Additively built components, packaging the sensors within the components, and characterizing the sensors for sensing a specified measurement. Optical fiber sensors are popular due to their small size, resilience against electromagnetic radiation, and reliability in potentially dangerous conditions. Embedding fibers inside a product allows for the monitoring of critical areas, allowing for preemptive action in the case of a breakdown. Coupons of Inconel 718 were made using laser powder-bed fusion (LPBF), with the fabrication settings tuned to determine whether such a development was possible. After …


Development And Characterization Of Forcespinning® Mesquite Gum Nanofibers, Cristobal Rodriguez, Victoria I. Padilla, Karen Lozano, Alexa Villarreal, Luis A. Materon, Robert Gilkerson Dec 2022

Development And Characterization Of Forcespinning® Mesquite Gum Nanofibers, Cristobal Rodriguez, Victoria I. Padilla, Karen Lozano, Alexa Villarreal, Luis A. Materon, Robert Gilkerson

Mechanical Engineering Faculty Publications and Presentations

In this study, nanofibers incorporating Prosopis glandulosa mesquite gum (MG) exudate combined with biodegradable polymers, pullulan (PL) and chitosan (CH), were produced via the Forcespinning® technique. The nonwoven composite membranes were characterized via scanning electron microscopy followed by thermogravimetric and Fourier-transform infrared spectroscopy analysis. MG nanofiber composites comprised long, continuous fibers with an average fiber diameter of 523 ± 180 nm and 760 ± 225 nm for 18.1 and 28 wt% of MG, respectively. These composite membranes were water-stable after crosslinking via heat treatment with a ∼3 % water absorption capacity, and demonstrated a thermal capability with an increasing …


Sensitivity Analysis Of Frost Deposition In Turbulent Flow Over A Cold Plate Using Direct Numerical Simulation, N. Farzaneh, ‪Nadim Zgheib, S. A. Sherif, S. Balachandar Nov 2022

Sensitivity Analysis Of Frost Deposition In Turbulent Flow Over A Cold Plate Using Direct Numerical Simulation, N. Farzaneh, ‪Nadim Zgheib, S. A. Sherif, S. Balachandar

Mechanical Engineering Faculty Publications and Presentations

We use a recently-developed, turbulence-informed physics-based model to study frost buildup over a flat plate subjected to turbulent flow. The plate temperature is held fixed but varied across simulations in the range −10◦C ≤ T∗ p ≤ −5◦C. Similarly, the free-stream temperature and humidity ratio are also held fixed but varied across simulations in the range 0◦C ≤ T∗∞ ≤ 20◦C and 3.77 × 10−3 ≤ ew∞ ≤ 1.47×10−2, respectively. We find the Nusselt and Sherwood numbers, when scaled by the frost surface to free stream temperature and humidity ratio difference, respectively, to become independent of free-stream temperature and humidity …


A Survey Of Smart Manufacturing For High-Mix Low-Volume Production In Defense And Aerospace Industries, Tanjida Tahmina, Mauro Garcia, Zhaohui Geng, Bopaya Bidanda Oct 2022

A Survey Of Smart Manufacturing For High-Mix Low-Volume Production In Defense And Aerospace Industries, Tanjida Tahmina, Mauro Garcia, Zhaohui Geng, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Defense and aerospace industries usually possess unique high-mix low-volume production characteristics. This uniqueness generally calls for prohibitive production costs and long production lead-time. One of the major trends in advanced, smart manufacturing is to be more responsive and better readiness while ensuring the same or higher production quality and lower cost. This study reviews the state-of-the-art manufacturing technologies to solve these issues and previews two levels of flexibility, i.e., system and process, that could potentially reduce the costs while increasing the production volume in such a scenario. The main contribution of the work includes an assessment of the current solutions …


Ultrafast Laser Direct Writing Of Conductive Patterns On Polyimide Substrate, Ishrat Jahan Biswas, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li Sep 2022

Ultrafast Laser Direct Writing Of Conductive Patterns On Polyimide Substrate, Ishrat Jahan Biswas, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Laser direct writing (LDW) is a fast and cost-effective method for printing conductive patterns in flexible polymer substrates. The electrical, chemical, and mechanical properties of polyimide (PI) make it an attractive material choice for laser writing of conductive circuits in such polymer. Electrically insulating PI has shown great potential for flexible printed electronics as LDW enables selective carbonization in the bulk of such material leading to the formation of conductive lines. However, existing studies in this area reveal a few key limitations of this approach including limited conductivity of written structures and fragility of carbonized PI. Therefore, more research is …


A Numerical Study On The Powder Flowability, Spreadability, Packing Fraction In Powder Bed Additive Manufacturing, Yeasir Mohammad Akib, Ehsan Marzbanrad, Farid Ahmed, Jianzhi Li Sep 2022

A Numerical Study On The Powder Flowability, Spreadability, Packing Fraction In Powder Bed Additive Manufacturing, Yeasir Mohammad Akib, Ehsan Marzbanrad, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The powder bed fusion (PBF) process is widely adopted in many manufacturing industries because of its capability to 3D print complex parts with micro-scale precision. In PBF process, a thermal energy source is used to selectively fuse powder particles layer by layer to build a part. The build quality in the PBF process primarily depends on the thermal energy deposition and properties of the powder bed. Powder flowability, powder spreading, and packing fraction are key factors that determine the properties of a powder bed. Therefore, the study of these process parameters is essential to better understand the PBF process. In …


Synthesizing And Printing Of Tin Oxide Nanoparticles Using A Single Ultrafast Laser System: A Feasibility Study, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li Sep 2022

Synthesizing And Printing Of Tin Oxide Nanoparticles Using A Single Ultrafast Laser System: A Feasibility Study, Enrique Contreras Lopez, Farid Ahmed, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

In laser-based manufacturing, processing setup customization is one of the popular approaches used to enhance diversity in material processing using a single laser. In this study, we propose setup design modification of an ultrafast laser system to demonstrate both Tin Oxide (SnO2) nanoparticle synthesis from bulk metal, and post printing of said nanoparticles using Laser Induced Forward Transfer (LIFT) method. Using the Pulse Laser Ablation in Liquid (PLA-L) method, nanoparticles were synthesized from a bulk tin metal cube submerged in distilled water. Such nanoparticles dispersed in water can form colloidal ink that can be used for different printed electronics applications. …


Turning Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Process Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S. M. Abdur Rob, Anil K. Srivastava Sep 2022

Turning Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Process Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S. M. Abdur Rob, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Carbon Fiber Reinforced Polymer (CFRP) composites have been widely used in aerospace, automotive, nuclear, and biomedical industries due to their high strength-to-weight ratio, corrosion resistance, durability, and excellent thermo-mechanical properties in non-oxidative atmospheres. Machining of CFRP composites has always been a challenge for manufacturers. In this research, a comparative study was performed between the optimal machining parameters of coated and uncoated carbide inserts obtained from the Multi-Objective Genetic Algorithm during turning of CFRP composites. It was found that coated carbide inserts provide lower tool wear and surface roughness, but higher cutting forces compared to those of uncoated carbide inserts …


Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda Sep 2022

Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Three-dimensional scanning is widely used for the dimension measurements of physical objects with freeform designs. The output point cloud is flexible enough to provide a detailed geometric description for these objects. However, geometric accuracy and precision are still debatable for this scanning process. Uncertainties are ubiquitous in geometric measurement due to many physical factors. One potential factor is the object’s posture in the scanning region. The posture of target positioning on the scanning platform could influence the normal of the scanning points, which could further affect the measurement variances. This paper first investigates the geometric and spatial factors that could …


Ultrafast Laser Ablation Of Inconel 718 For Surface Improvement, Sampson Canacoo, Enrique Contreras Lopez, Oscar Coronel, Farid Ahmed, Jianzhi Li, Anil K. Srivastava Sep 2022

Ultrafast Laser Ablation Of Inconel 718 For Surface Improvement, Sampson Canacoo, Enrique Contreras Lopez, Oscar Coronel, Farid Ahmed, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Inconel 718 is considered difficult to machine because of its ability to maintain its properties at high temperatures. The low thermal conductivity of the alloy causes accelerated tool deterioration when machining. Selective laser melting (SLM) additive manufacturing introduces a possibility of eliminating these difficulties, and producing complex shapes with this difficult-to-machine material. However, high surface roughness and porosity usually occur at the surface of components produced through additive manufacturing. In this study, the surfaces of Inconel 718 samples produced through selective laser melting were treated using laser ablation. The process parameters for the laser ablation process were analyzed in …


Minimax Registration For Point Cloud Alignment, Zhaohui Geng, Mauro Garcia, Bopaya Bidanda Sep 2022

Minimax Registration For Point Cloud Alignment, Zhaohui Geng, Mauro Garcia, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The alignment, or rigid registration, of three-dimensional (3D) point clouds plays an important role in many applications, such as robotics and computer vision. Recently, with the improvement in high precision and automated 3D scanners, the registration algorithm has become critical in a manufacturing setting for tolerance analysis, quality inspection, or reverse engineering purposes. Most of the currently developed registration algorithms focus on aligning the point clouds by minimizing the average squared deviations. However, in manufacturing practices, especially those involving the assembly of multiple parts, an envelope principle is widely used, which is based on minimax criteria. Our present work …


In-Person Instruction Or Remote Learning?: Understanding Students' Learning Experiences During Covid-19, Eleazar Marquez, Samuel Garcia Aug 2022

In-Person Instruction Or Remote Learning?: Understanding Students' Learning Experiences During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

Research attests that student success in engineering education is cultivated largely due to classroom environments, academic inclusion, and engagement in undergraduate research. It is further revealed that the social and academic fabric of the institution such as academic advising, peer tutoring, disability services, and outdoor recreational programs is essential towards fostering well-being, recruitment, retention, and student success. However, these studies were conducted in a period in which students experienced traditional face-to-face instruction. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, educators were …


Navigating The Virtual Landscape: Implementing A Pedagogical Framework In A Virtual Summer Engineering Course To Enhance Students' Academic Development, Eleazar Marquez, Samuel Garcia Aug 2022

Navigating The Virtual Landscape: Implementing A Pedagogical Framework In A Virtual Summer Engineering Course To Enhance Students' Academic Development, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications and Presentations

In this evidence-based practice paper, the recently established CIRE educational model was incorporated, and modified, to establish an alternative pedagogical framework for a virtual, fast-paced summer engineering course in a private university in Texas. Transitioning to fully online courses in the wake of COVID-19 required a rapid modification of traditional pedagogical methods to overcome challenges such as the lack of academic resources and established campus practices, while simultaneously ensuring the academic and social development of students. In this regard, a pedagogical framework known as the CIRE model – which is the acronym for Communication, Initiation, Reduction, and Extension – was …


Disruptions In International Trade: A Perspective On Ports Of Entry And Supply Chain Resilience, Jose A. Jara Jr. Guerrero Aug 2022

Disruptions In International Trade: A Perspective On Ports Of Entry And Supply Chain Resilience, Jose A. Jara Jr. Guerrero

Theses and Dissertations

United States (U.S.) ports of entry (POEs) and supply chains (SCs) have a prominent trade relationship with a growing desire to improve their operational capabilities. Though trade deals like the U.S.-Mexico-Canada (USMCA) agreement have facilitated trade between these countries, U.S. Customs and Border Protection (CBP) at POEs have also increased security inspections, following the September 11th incident, which have impacted international and global SCs. More recently, the COVID-19 pandemic has caused labor shortages at both sea and land POEs, increasing vessel and commercial vehicle congestion. These POE disruptions have also propagated into the third-party logistics (3PL) of SC networks, which …


Development Of A Bootcamp For Freshman Student Success During Covid-19 Transition, Eleazar Marquez, Noe Vargas Hernandez, Arturo Fuentes Aug 2022

Development Of A Bootcamp For Freshman Student Success During Covid-19 Transition, Eleazar Marquez, Noe Vargas Hernandez, Arturo Fuentes

Mechanical Engineering Faculty Publications and Presentations

Results from assessment show that passing rates in introductory courses as well as retention rates of first-year students in the College of Engineering and Computer Science at a HSI significantly dropped with the advent of COVID-19. Such results and trends provide an overall perspective on the academic preparation of incoming students. There is a high concern that the necessary skill set (e.g., adaptability, persistence, and performance) of the new cohort of students, who are primarily underrepresented Hispanics from underserved and challenged communities from the Rio Grande Valley, is not optimal for the rigor of engineering education. To this end, an …


Lubrication Performance Of Sunflower Oil Reinforced With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas, Md Mashfiqur Rahman, Javier A. Ortega, Laura Peña-Parás, Demófilo Maldonado-Cortés, José A. González, Ricardo Cantú, Adrián Campos, Eugenio Flores Jul 2022

Lubrication Performance Of Sunflower Oil Reinforced With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas, Md Mashfiqur Rahman, Javier A. Ortega, Laura Peña-Parás, Demófilo Maldonado-Cortés, José A. González, Ricardo Cantú, Adrián Campos, Eugenio Flores

Mechanical Engineering Faculty Publications and Presentations

This study evaluates the tribological performance of nanolubricants of a vegetable oil (sunflower oil) reinforced with different concentrations of environmentally-friendly nanoparticles of halloysite clay nanotubes (HNTs). Tribological characterization was performed under different conditions to determine its effect on the nanolubricants’ performance and optimal HNT concentration. The tribological performances under low and high contact pressures were analyzed with a block-on-ring tribometer following the ASTM G-077-05 standard procedure. The extreme pressure (EP) properties of the nanolubricants were determined with a T-02 four-ball tribotester according to the ITeE-PIB Polish method for testing lubricants under scuffing conditions. In addition, the lubrication performance of the …


Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca Jul 2022

Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca

Theses and Dissertations

By continuously monitoring train bearing health in terms of temperature and vibration levels of bearings tested in a laboratory setting, statistical regression models have been developed to establish relationships between the sensor-acquired bearing health data with several explanatory factors that potentially influence the bearing deterioration. Despite their merits, statistical models fall short of reliable prediction accuracy levels since they entail restrictive assumptions, such as a priori known functional relationship between the response and input variables. A data-driven machine learning algorithm is presented, which can unravel the nonlinear deterioration model purely based on the bearing health data, even when the structure …


Conductive Polymer Pad For Use In Freight Railcar Bearing Adapters, Jesse Aguilera, Constantine Tarawneh, Harry Siegel, Robert Jones, Santana Gutierrez Jun 2022

Conductive Polymer Pad For Use In Freight Railcar Bearing Adapters, Jesse Aguilera, Constantine Tarawneh, Harry Siegel, Robert Jones, Santana Gutierrez

Mechanical Engineering Faculty Publications and Presentations

Many freight railcars rest on polymer adapter pads made of injection-molded Thermoplastic Polyurethane (TPU) polymers which feature two copper studs to provide electrical conductivity through the pad. This design feature allows signal transmission from the track to the onboard systems, including cargo gates and pneumatic actuators. While in service, the polymer pads experience impact and cyclic loading that produce shear, resulting in the abrasive wear and plastic compression of the copper studs which leads to signal interruptions and loss of function requiring the periodic replacement of these polymer pads. This causes increased downtime due to maintenance and reduced reliability in …


Transient Thermal Analysis Of A Railroad Bearing Adapter For Optimal Placement Of Onboard Sensors, Javier E. Arroyo, Constantine Tarawneh, Arturo Fuentes, Roberto A. Garcia, Jose G. Gallegos Jun 2022

Transient Thermal Analysis Of A Railroad Bearing Adapter For Optimal Placement Of Onboard Sensors, Javier E. Arroyo, Constantine Tarawneh, Arturo Fuentes, Roberto A. Garcia, Jose G. Gallegos

Mechanical Engineering Faculty Publications and Presentations

Bearing temperature serves as an important metric used in identifying defective bearings in the rail industry. Current defect detection systems, such as the Hot Box Detectors (HBDs), are used to measure the temperature of freight car roller bearings. The HBD is a wayside device that utilizes a non-contact infrared sensor to determine the operating temperature of a railroad bearing as it passes over the HBD. Railroads analyze the data collected by HBDs to detect and flag defective bearings. If the operating temperature of a bearing surpasses a predetermined threshold, an emergency stop is initiated, and the bearing is removed from …