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University of Texas Rio Grande Valley

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Articles 151 - 180 of 666

Full-Text Articles in Mechanical Engineering

Computational Modelling Of A Triaxial Vibrating Sample Magnetometer, Leo Rodriguez, Arjun Sapkota, Jonathan Alvarado, Jitendra S. Tate, Wilhelmus J. Geerts Feb 2024

Computational Modelling Of A Triaxial Vibrating Sample Magnetometer, Leo Rodriguez, Arjun Sapkota, Jonathan Alvarado, Jitendra S. Tate, Wilhelmus J. Geerts

Mechanical Engineering Faculty Publications

Magnetic Field Assisted Additive Manufacturing (MFAAM) enables 3D printing of magnetic materials of various shapes which exhibit a complex anisotropy energy surface containing contributions generated from different origins such as sample, particle, and agglomerate shape anisotropy, flow and field induced anisotropy, and particle crystal anisotropy. These novel magnet shapes require the need to measure the x, y, and z components of the magnetic dipole moment simultaneously to fully understand the magnetic reversal mechanism and unravel the complex magnetic anisotropy energy surface of 3D printed magnetic composites. This work aims to develop a triaxial vibrating sample magnetometer (VSM) by adding a …


Fibrous Finite Element Modeling Of The Optic Nerve Head Region, Mohammad R. Islam, Fengting Ji, Manik Bansal, Yi Hua, Ian A. Sigal Feb 2024

Fibrous Finite Element Modeling Of The Optic Nerve Head Region, Mohammad R. Islam, Fengting Ji, Manik Bansal, Yi Hua, Ian A. Sigal

Mechanical Engineering Faculty Publications

The optic nerve head (ONH) region at the posterior pole of the eye is supported by a fibrous structure of collagen fiber bundles. Discerning how the fibrous structure determines the region biomechanics is crucial to understand normal physiology, and the roles of biomechanics on vision loss. The fiber bundles within the ONH structure exhibit complex three-dimensional (3D) organization and continuity across the various tissue components. Computational models of the ONH, however, usually represent collagen fibers in a homogenized fashion without accounting for their continuity across tissues, fibers interacting with each other and other fiber-specific effects in a fibrous structure. We …


A Simulation Model Analysis In The Us-Mexico Border, Carlo A. Zorola, Hiram Moya, Aditya Akundi Jan 2024

A Simulation Model Analysis In The Us-Mexico Border, Carlo A. Zorola, Hiram Moya, Aditya Akundi

Manufacturing & Industrial Engineering Faculty Publications

Supply Chain (SC) is the flow of goods or services between supply and demand points. New or innovative strategies in SC have been researched and developed to deal with disruptive events, such as COVID-19, hurricanes, geopolitical, and even climate change. These challenges create supply imbalances, logistical challenges, and policy restrictions for transborder commerce. The DHS has implemented the Free and Secure Trade (FAST) program in both the US-Mexico and US-Canada border. These lanes are dedicated queues for commercial vehicles. In 2022, the government of Nuevo León, México, opened a dedicated lane just for Tesla´s northbound commercial traffic. There has been …


Artificial Intelligence For Enhanced Flotation Monitoring In The Mining Industry: A Convlstm-Based Approach, Ahmed Bendaouia, El Hassan Abdelwahed, Sara Qassimi, Abdelmalek Boussetta, Intissar Benzakour, Oumkeltoum Amar, Oussama Hasidi Jan 2024

Artificial Intelligence For Enhanced Flotation Monitoring In The Mining Industry: A Convlstm-Based Approach, Ahmed Bendaouia, El Hassan Abdelwahed, Sara Qassimi, Abdelmalek Boussetta, Intissar Benzakour, Oumkeltoum Amar, Oussama Hasidi

Manufacturing & Industrial Engineering Faculty Publications

In the mining industry, accurate monitoring of the elemental composition in the flotation froth is crucial for efficient minerals separation. The hybrid deep learning algorithms offer powerful computational intelligence for real-time monitoring of froth quality in flotation processes. This soft sensor tool can provide valuable information for process control, including predictions of the elemental chemical composition. In this study, we propose a novel approach based on a Convolutional Long Short-Term Memory (ConvLSTM) neural network for real-time monitoring of chemical composition grades in flotation froth. The proposed model effectively extracts spatial and temporal patterns from video data, providing a better …


Near-Optimal Trajectory Tracking In Quadcopters Using Reinforcement Learning, Randal Engelhardt, Alberto Velazquez, Tohid Sardarmehni Jan 2024

Near-Optimal Trajectory Tracking In Quadcopters Using Reinforcement Learning, Randal Engelhardt, Alberto Velazquez, Tohid Sardarmehni

Mechanical Engineering Faculty Publications

The control of quadcopters poses significant challenges due to their complex dynamics characterized by highly nonlinear couplings, high system order, and under-actuation. This paper presents a novel control solution aimed at achieving near-optimal trajectory tracking for quadcopters. A near-optimal solution based on approximate dynamic programming is proposed to address the curse of dimensionality inherent in traditional dynamic programming, employing a single network adaptive critic. Extensive simulations validate the effectiveness and robustness of the proposed solution.


Functionalized Thermoplastic Polyurethane Nanofibers: An Innovative Triboelectric Energy Generator, Julia I. Salas, Diego De Leon, Sk Shamim Hasan Abir, Mohammed Jasim Uddin, Karen Lozano Dec 2023

Functionalized Thermoplastic Polyurethane Nanofibers: An Innovative Triboelectric Energy Generator, Julia I. Salas, Diego De Leon, Sk Shamim Hasan Abir, Mohammed Jasim Uddin, Karen Lozano

Mechanical Engineering Faculty Publications

A triboelectric nanogenerator (TENG) is one of the most significantly innovative microdevices for built-in energy harvesting with wearable and portable electronics. In this study, the forcespinning technology was used to synthesize a nanofiber (NF) mat-based TENG. Polyvinylidene fluoride (PVDF) membrane was used as the negative triboelectric electrode/pole, and chemically designed and functionalized thermoplastic polyurethane (TPU) was used as the positive electrode/pole for the TENG. The electronic interference, sensitivity, and gate voltage of the synthesized microdevices were investigated using chemically modified bridging of multi-walled carbon nanotubes (MWCNT) with a TPU polymer repeating unit and bare TPU-based positive electrodes. The chemical functionality …


Process-Structure-Property Relationships Of Nanofibers For Biomedical Applications, Dipasree Bhowmick Dec 2023

Process-Structure-Property Relationships Of Nanofibers For Biomedical Applications, Dipasree Bhowmick

Theses and Dissertations

This thesis explores the fabrication, characterization, and applications of nanofiber membranes utilizing Forcespinning® technology. Two distinct nanofiber systems were developed and evaluated, one focusing on pH-responsive Eudragit-baicalin loaded nanofibrous membranes for wound healing and the second one on thermo-responsive nanofiber-hydrogel (PNIPAAm) systems for biosensing applications, specifically dopamine detection. In the first project, nanofiber membranes loaded with Eudragit and baicalin demonstrated superior antibacterial properties against both gram-negative (E. coli) and gram-positive (B. meg) bacteria. Additionally, these membranes exhibited antioxidant properties and enhanced cell proliferation of 3TT cells, making them promising candidates for wound healing dressings. In the second project, a …


Laser Assisted Direct Writing Of Liquid Metal For Microprinting Applications, Olga Vargas Cruz Dec 2023

Laser Assisted Direct Writing Of Liquid Metal For Microprinting Applications, Olga Vargas Cruz

Theses and Dissertations

This paper presents a research study for potential printing of a Liquid Metal (LM) Eutectic Gallium Indium alloy (EGaIn) through the applications of the innovative additive manufacturing technology LIFT (Laser Induced Forward Transfer). LIFT is a precise printing technology that allows to create small, detailed printing. The liquid metal in study, EGaIn, has demonstrated great potential for microelectronics applications due to its minimum toxicity and high conductivity. Throughout this research different printing parameters are studied to comprehend the behavior of EGaIn printing with LIFT technique, these include laser energy, laser pulse, receiver material substrate, donor layer thickness, and …


Effects Of The Build Orientation And Support Patterns On The Geometric Accuracy In Printing Parts With Overhang Structure: An Experimental Study, Bala Murali Krishna Mohan Dec 2023

Effects Of The Build Orientation And Support Patterns On The Geometric Accuracy In Printing Parts With Overhang Structure: An Experimental Study, Bala Murali Krishna Mohan

Theses and Dissertations

Additive manufacturing is becoming increasingly popular in industries such as manufacturing due to its ability to use raw materials more efficiently and require less machining than traditional methods(Calignano et al., 2017). However, constructing overhanging structures in additive manufacturing can be challenging, potentially affecting the overall geometric quality of the printed components. The objective of this study was to identify the most effective printing orientation for overhanging designs in Fused Deposition Modeling (FDM) using two different support structures. To achieve this, the researchers used a laser scanner to collect point cloud data and conducted a comparative study to determine the …


Human-Centric Smart Cities: A Digital Twin-Oriented Design Of Interactive Autonomous Vehicles, Oscar G. De Leon-Vazquez Dec 2023

Human-Centric Smart Cities: A Digital Twin-Oriented Design Of Interactive Autonomous Vehicles, Oscar G. De Leon-Vazquez

Theses and Dissertations

Autonomous vehicle (AV) technology is introduced as a solution to improve transportation safety by eliminating traffic accidents caused by human error, which is the leading cause of 90% of accidents. One key feature of AVs is sensing and perceiving their surrounding environment through processing observations collected from the environment. The perception system is essential for an AV to make informed decisions and safely navigate the environment. This study presents an image semantic segmentation algorithm developed in the area of computer vision to improve AV perception. The U-Net-based algorithm is trained and validated using a synthetically generated dataset in a simulation …


Amplitude-Voltage Response Of Parametric Resonance Of Electrostatically Actuated Circular Membranes, Marcos Alipi, Dumitru I. Caruntu Nov 2023

Amplitude-Voltage Response Of Parametric Resonance Of Electrostatically Actuated Circular Membranes, Marcos Alipi, Dumitru I. Caruntu

Mechanical Engineering Faculty Publications

This paper deals with the amplitude-voltage response of parametric resonance of electrostatically actuated MEMS circular membranes resonator for sensing applications. The system consists of a flexible circular membrane over a parallel ground plate. A soft AC voltage is applied between the MEMS membrane and ground plate to actuate the membrane near its first natural frequency. Two methods of investigation are used in this research, namely the method of multiple scales (MMS), and the reduced order model (ROM). These methods were used to solve for the voltage response of the MEMS analytically and numerically. This work also reports the effects the …


Mems Cantilever Biosensors Driven By Fringe Effect: Voltage-Amplitude Response Of Parametric Resonance, Miguel A. Martinez, Dumitru I. Caruntu Nov 2023

Mems Cantilever Biosensors Driven By Fringe Effect: Voltage-Amplitude Response Of Parametric Resonance, Miguel A. Martinez, Dumitru I. Caruntu

Mechanical Engineering Faculty Publications

This paper deals with voltage-amplitude response of fringing field/effect actuated micro-electromechanical system (MEMS) cantilever beam resonator biosensors at parametric resonance. The system consists of a flexible electrode (cantilever beam) and a fixed electrode (ground plate) in parallel, connected through an AC voltage source. The electrostatic force induced is due to the parallel-plate capacitance, which is directly related to the overlapping area of the two electrodes (Palmer’s Formula). In addition, fringing field electrostatic actuation must be accounted for. This is due to the bending of electric field lines from the ground plate to the top and side walls of the cantilever …


Thermal Transport And Rheological Properties Of Hybrid Nanofluids Based On Vegetable Lubricants, Helio Ribeiro, Jaime Taha-Tijerina, Ofelia Gomez, Ever Acosta, Gabriel M. Pinto, Lorena R. C. Moraes, Guilhermino J. M. Fechine, Ricardo J. E. Andrade, Jefferson Reinoza, Victoria Padilla, Karen Lozano Oct 2023

Thermal Transport And Rheological Properties Of Hybrid Nanofluids Based On Vegetable Lubricants, Helio Ribeiro, Jaime Taha-Tijerina, Ofelia Gomez, Ever Acosta, Gabriel M. Pinto, Lorena R. C. Moraes, Guilhermino J. M. Fechine, Ricardo J. E. Andrade, Jefferson Reinoza, Victoria Padilla, Karen Lozano

Mechanical Engineering Faculty Publications

Nanofluids based on vegetal oil with different wt.% of carbon nanotubes (CNT), hexagonal boron nitride (h-BN), and its hybrid (h-BN@CNT) were produced to investigate the effects of these nano-additives on the thermal conductivity and rheological properties of nanofluids. Stable suspensions of these oil/nanostructures were produced without the use of stabilizing agents. The dispersed nanostructures were investigated by SEM, EDS, XRD, and XPS, while the thermal conductivity and rheological characteristics were studied by a transient hot-wire method and steady-state flow tests, respectively. Increases in thermal conductivity of up to 39% were observed for fluids produced with 0.5 wt.% of the hybrid …


Development Of Pullulan/Chitosan/Salvianolic Acid Ternary Fibrous Membranes And Their Potential For Chemotherapeutic Applications, Salahuddin Ahmed, Megan Keniry, Victoria Padilla, Narcedalia Anaya-Barbosa, Md Noushad Javed, Robert Gilkerson, Kithzia Gomez, Acharan S. Narula, Karen Lozano Oct 2023

Development Of Pullulan/Chitosan/Salvianolic Acid Ternary Fibrous Membranes And Their Potential For Chemotherapeutic Applications, Salahuddin Ahmed, Megan Keniry, Victoria Padilla, Narcedalia Anaya-Barbosa, Md Noushad Javed, Robert Gilkerson, Kithzia Gomez, Acharan S. Narula, Karen Lozano

Mechanical Engineering Faculty Publications

This study investigates the feasibility of centrifugal spinning for producing fibrous membranes containing pullulan, chitosan, and danshen extract. The danshen extract is composed of 20 wt% salvianolic acid B (SA). Citric acid was added to the mixture as a crosslinking agent to promote its use in the aqueous medium. The influence of the danshen concentration (25 wt% and 33 wt%) on fiber morphology, thermal behavior, and the biochemical effect was analyzed. Developed fiber-based membranes consist of long, continuous, and uniform fibers with a sparse scattering of beads. Fiber diameter analysis shows values ranging from 384 ± 123 nm to 644 …


Effect Of Room Size, Shape, Ac Placement, And Air Leakage On Indoor Airborne Viral Transmission, K. Choudhary, K. A. Krishnaprasad, ‪Nadim Zgheib, M. Y. Ha, S. Balachandar Oct 2023

Effect Of Room Size, Shape, Ac Placement, And Air Leakage On Indoor Airborne Viral Transmission, K. Choudhary, K. A. Krishnaprasad, ‪Nadim Zgheib, M. Y. Ha, S. Balachandar

Mechanical Engineering Faculty Publications

Highlights

  • Statistical overloading is used to obtain spatio-temporal pathogen concentration.

  • Symmetrically placed AC limits pathogen propagation over long distances.

  • Well-mixed model captures room-averaged concentration for any shape and AC location.

  • The pathogens level of mixing is reduced when AC is symmetrically positioned.

  • Air leakage has insignificant impact on indoor pathogen distribution.

Abstract

We conducted Euler–Lagrange Reynolds-Averaged Navier–Stokes simulations with statistical overloading to investigate the effect of room shape, air-condition (AC) location, and the presence of an open window on indoor airborne viral transmission, particularly as it relates to the spatio-temporal distribution of viral-laden droplet nuclei. Two room geometries were …


Numerical Study Of Solar Receiver Tube With Modified Surface Roughness For Enhanced And Selective Absorptivity In Concentrated Solar Power Tower, Shawn Hatcher, Mathew Z. Farias, Jianzhi Li, Peiwen Li, Ben Xu Sep 2023

Numerical Study Of Solar Receiver Tube With Modified Surface Roughness For Enhanced And Selective Absorptivity In Concentrated Solar Power Tower, Shawn Hatcher, Mathew Z. Farias, Jianzhi Li, Peiwen Li, Ben Xu

Manufacturing & Industrial Engineering Faculty Publications

Concentrated solar power (CSP) is a reliable renewable energy source that is progressively lowering its cost of energy. However, the heat loss due to reflected and emitted radiation hinders the maximum achievable thermal efficiency for solar receiver tubes on the solar tower. Current solar selective coatings cannot withstand the high temperatures that come with state-of-the-art CSP towers often needing to be recoated soon after initial operation. We intend to use Inconel 718 with different additive manufacturing (AM) practices to construct surfaces that allow for more light-trapping to occur. By adjusting printing parameters, we can tailor a surface to allow for …


A Facile Graphene Conductive Polymer Paper Based Biosensor For Dopamine, Tnf-Α, And Il-6 Detection, Md Ashiqur Rahman, Ramendra Kishor Pal, Nazmul Islam, Robert Freeman, Francois Berthiaume, Aaron Mazzeo, Ali Ashraf Sep 2023

A Facile Graphene Conductive Polymer Paper Based Biosensor For Dopamine, Tnf-Α, And Il-6 Detection, Md Ashiqur Rahman, Ramendra Kishor Pal, Nazmul Islam, Robert Freeman, Francois Berthiaume, Aaron Mazzeo, Ali Ashraf

Mechanical Engineering Faculty Publications

Paper-based biosensors are a potential paradigm of sensitivity achieved via microporous spreading/microfluidics, simplicity, and affordability. In this paper, we develop decorated paper with graphene and conductive polymer (herein referred to as graphene conductive polymer paper-based sensor or GCPPS) for sensitive detection of biomolecules. Planetary mixing resulted in uniformly dispersed graphene and conductive polymer ink, which was applied to laser-cut Whatman filter paper substrates. Scanning electron microscopy and Raman spectroscopy showed strong attachment of conductive polymer-functionalized graphene to cellulose fibers. The GCPPS detected dopamine and cytokines, such as tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) in the ranges of 12.5–400 …


Effects Of Machining Parameters Of C45 Steel Applying Vegetable Lubricant With Minimum Quantity Cooling Lubrication (Mqcl), Mayur A. Makhesana, Prashant J. Bagga, Kaushik M. Patel, Jaime Taha-Tijerina Aug 2023

Effects Of Machining Parameters Of C45 Steel Applying Vegetable Lubricant With Minimum Quantity Cooling Lubrication (Mqcl), Mayur A. Makhesana, Prashant J. Bagga, Kaushik M. Patel, Jaime Taha-Tijerina

Informatics and Engineering Systems Faculty Publications

One of the most significant performance indicators for measuring the machinability of materials is tool wear and surface roughness. Choosing the best combination of cutting parameters can help reduce production costs, which is what the manufacturing industry is interested in. At the same time, industries are always looking for an alternative to conventional flood cooling since its use creates an environmental burden and health concerns for the operators. Therefore, vegetable oil-based minimum quantity cooling lubrication (MQCL) is considered a cutting environment. Sunflower oil is utilized as base fluid in MQCL and applied to the cutting zone through a nozzle. The …


Explainable Ai (Xai)-Driven Vibration Sensing Scheme For Surface Quality Monitoring In A Smart Surface Grinding Process, Abhishek Hanchate, Satish T.S. Bukkapatnam, Kye Hwan Lee, Anil K. Srivastava, Soundar Kumara Aug 2023

Explainable Ai (Xai)-Driven Vibration Sensing Scheme For Surface Quality Monitoring In A Smart Surface Grinding Process, Abhishek Hanchate, Satish T.S. Bukkapatnam, Kye Hwan Lee, Anil K. Srivastava, Soundar Kumara

Manufacturing & Industrial Engineering Faculty Publications

Local Interpretable and Model-agnostic Explanation (LIME), an explainable artificial intelligence (XAI) approach is adapted to identify the globally important time-frequency bands for predicting average surface roughness (Ra) in a smart grinding process. The smart grinding setup consisted of a Supertech CNC precision surface grinding machine, instrumented with a Dytran piezoelectric accelerometer attached to the tailstock quill along the tangential direction (Y-axis). For every grinding pass, vibration signatures were captured, and the ground truth surface roughness values were recorded using a Mahr Marsurf M300C portable surface roughness profilometer. The roughness values ranged from 0.06 to 0.14 microns over the complete set …


Design And Implementation Of A Load Sensor In A Bearing Adapter Assembly For Freight Railcar Applications, Prince E. Mensah Aug 2023

Design And Implementation Of A Load Sensor In A Bearing Adapter Assembly For Freight Railcar Applications, Prince E. Mensah

Theses and Dissertations

The U.S. freight rail network, which covers approximately 140,000 route miles, is commonly regarded as the largest, safest, and most economical freight system in the world. It generates more than 167,000 jobs nationwide and has additional advantages over other modes of transportation, such as lower costs for logistics, public infrastructure upkeep, and decreases in traffic congestion, highway deaths, fuel consumption, and greenhouse gas emissions. Knowing the exact weight of cargo hauled by freight railcars can help avoid exceeding the loading thresholds set by the Association of American Railroads (AAR). Moreover, knowing the exact load applied to each bearing on the …


Vibration-Based Machine Learning Models For Condition Monitoring Of Railroad Rolling Stock, Sergio M. Martinez Aug 2023

Vibration-Based Machine Learning Models For Condition Monitoring Of Railroad Rolling Stock, Sergio M. Martinez

Theses and Dissertations

One of the primary causes of rail rolling stock derailments is attributed to bearing and wheel axle failures. The health of train bearings is primarily monitored at target locations through wayside detection systems. This practice is susceptible to bearing failure and potential derailments at points in between these wayside systems. To remedy this, the University Transportation Center for Railway Safety (UTCRS) has developed a wireless onboard monitoring system that can continuously monitor the vibration response, which directly correlates to the health of bearings. This data is used to train regression-based machine learning algorithms and long-term prediction neural networks to predict …


Developing Control System For Manufacturing Processes, Md Shahriar Forhad Aug 2023

Developing Control System For Manufacturing Processes, Md Shahriar Forhad

Theses and Dissertations

Process control has been a critical component in today's manufacturing industry. Industrialists nowadays want reliable control to assure precision manufacturing. Modern control systems must be more dynamic, so that any needed modifications may be made quickly to accomplish the desired product change. For innovative research and development, system customization is critical to ensure freedom for experimental works. In addition, full control of manufacturing systems is necessary to realize and implement Industry 4.0. Often, it is difficult to achieve such control due to limited access to proprietary equipment. To this end, this thesis focuses on developing a custom control platform for …


Laser-Induced Forward Transfer (Lift) Based Bioprinting Of The Collagen I With Retina Photoreceptor Cells, Md Shakil Arman, Ben Xu, Andrew Tsin, Jianzhi Li Aug 2023

Laser-Induced Forward Transfer (Lift) Based Bioprinting Of The Collagen I With Retina Photoreceptor Cells, Md Shakil Arman, Ben Xu, Andrew Tsin, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications

This study focuses on the 3D bioprinting of retina photoreceptor cells using a laser-induced forward transfer (LIFT) based bioprinting system. Bioprinting has a great potential to mimic and regenerate the human organoid system, and the LIFT technique has emerged as an efficient method for high-resolution micropatterning and microfabrication of biomaterials and cells due to its capability of creating precise, controlled microdroplets. In this study, the parameters for an effective femtosecond laser-based LIFT process for 3D bioprinting of collagen biomaterial were studied. Different concentrations of collagen I solutions were tested and 0.75 mg/ml to 1 mg/ml collagen Ⅰ was identified as …


Two-Dimensional Nanomaterials And Nanocomposites For Sensing, Separation, And Energy Applications, Md Ashiqur Rahman Aug 2023

Two-Dimensional Nanomaterials And Nanocomposites For Sensing, Separation, And Energy Applications, Md Ashiqur Rahman

Theses and Dissertations

Two-dimension (2D) nanomaterials have gained popularity for the last few decades due to their excellent mechanical, electrical and thermal properties. These unique properties of 2D nanomaterials can be exploited in various applications specially in sensor, energy, and separation devices. In this study, the sensing and energy generation performance of PVDF/PAni fiber mat systems made by the forcespinning method with and without graphene coating. The graphene-coated nanocomposites show an average output voltage of 75 mV (peak-to-peak) which is 300% higher compared to bare fiber mats and an output current of 24 mA (peak-to-peak) by gentle finger pressing. Moreover, the graphene-coated PVDF/PAni …


Aerodynamic Flow Control Using Micro Rotating Cylinders, Alejandro Daniel Carrizales Aug 2023

Aerodynamic Flow Control Using Micro Rotating Cylinders, Alejandro Daniel Carrizales

Theses and Dissertations

This research investigates the aerodynamic and flow field characteristics of a NACA 0010 airfoil equipped with rotating cylinders near the leading edge, subjected to a flow with a freestream turbulence intensity of 4.3%. The airfoil was modified to integrate five micro-DC motors positioned at 14.5% of the chord length from the leading edge. The cylinders, with dimensions of 0.75 inches in diameter and 0.5 inches in width, exposed 3mm of their length to the incoming flow. A modified leading edge with eight sinusoidal protrusions (tubercles) was employed to compare the performance of the micro-rotating cylinder airfoil with an unmodified baseline …


Multifunctional Graphene–Polymer Nanocomposite Sensors Formed By One-Step In Situ Shear Exfoliation Of Graphite, Ali Ashraf, Elizabeth Chang, Md Ashiqur Rahman, Dipannita Ghosh, Nazmul Islam, Jennifer K. Lynch-Branzoi Jul 2023

Multifunctional Graphene–Polymer Nanocomposite Sensors Formed By One-Step In Situ Shear Exfoliation Of Graphite, Ali Ashraf, Elizabeth Chang, Md Ashiqur Rahman, Dipannita Ghosh, Nazmul Islam, Jennifer K. Lynch-Branzoi

Mechanical Engineering Faculty Publications

Graphene nanocomposites are a promising class of advanced materials for sensing applications; yet, their commercialization is hindered due to impurity incorporation during fabrication and high costs. The aim of this work is to prepare graphene–polysulfone (G−PSU) and graphene–polyvinylidene fluoride (G−PVDF) nanocomposites that perform as multifunctional sensors and are formed using a one-step, in situ exfoliation process whereby graphite is exfoliated into graphene nanoflakes (GNFs) directly within the polymer. This low-cost method creates a nanocomposite while avoiding impurity exposure since the raw materials used in the in situ shear exfoliation process are graphite and polymers. The morphology, structure, thermal properties, and …


Estudio Termoquímico Asistido Por Computadora De Los Polifenoles Presentes En La Fresa [Thermochemical Computer Assisted Study Of Polyphenols Presented In Strawberry], Federico Lopez, Jeimmy Rocio Bonilla Méndez, Luis Ricárdez Sandoval, Hiram Moya, Daniela Mainardi, Arturo González Quiroga, Jeffrey Leon-Pulido Jul 2023

Estudio Termoquímico Asistido Por Computadora De Los Polifenoles Presentes En La Fresa [Thermochemical Computer Assisted Study Of Polyphenols Presented In Strawberry], Federico Lopez, Jeimmy Rocio Bonilla Méndez, Luis Ricárdez Sandoval, Hiram Moya, Daniela Mainardi, Arturo González Quiroga, Jeffrey Leon-Pulido

Manufacturing & Industrial Engineering Faculty Publications

Las fresas son un alimento importante en Latinoamérica debido a sus componentes químicos, puesto que son una considerable fuente de calorías y polifenoles. Estos elementos son útiles por su capacidad antioxidante y otras propiedades beneficiosas para la salud. Sin embargo, la presión y la temperatura pueden llegar a afectar la integridad molecular de estos componentes, por lo tanto, en el proceso de producción de diferentes productos basados en fresas, se requiere estudiar las propiedades termoquímicas de los diferentes polifenoles presentes en esta fruta. Para ello, se extrajeron datos de las principales familias de polifenoles, antocianinas, flavanoles, flavonoles, ácidos hidroxibenzoicos y …


Regulating The Size And Assembled Structure Of Graphene Building Blocks For High-Performance Silicon Nanocomposite Anodes, Bo Nie, David Sanchez, Mataz Alcoutlabi, Tengxiao Liu, Saurabh Basu, Soundar Kumara, Gongkai Wang, Hongtao Sun Jul 2023

Regulating The Size And Assembled Structure Of Graphene Building Blocks For High-Performance Silicon Nanocomposite Anodes, Bo Nie, David Sanchez, Mataz Alcoutlabi, Tengxiao Liu, Saurabh Basu, Soundar Kumara, Gongkai Wang, Hongtao Sun

Mechanical Engineering Faculty Publications

Silicon-based composites have received significant interest as a high-capacity anode material for high-performance lithium-ion batteries. However, the large volume change during prolonged charge/discharge cycles, poor electric conductivity, and unstable solid electrolyte interface of the Si electrodes lead to performance degradations, such as fast capacity decay and low coulombic efficiency (CE). It's promising but challenging to fabricate Si-based composite anodes with a high Si active material, which enables high energy density, high-rate capability, and good cycling stability. Herein, the size effect of mechanically robust and highly conductive graphene sheets was investigated to effectively regulate the charge transport kinetics, volume changes, first …


Tio2 Coating Methods On Sb2o3 And Their Use As Anode Material In Lithium-Ion Batteries, Kithzia Czarina Gomez Jul 2023

Tio2 Coating Methods On Sb2o3 And Their Use As Anode Material In Lithium-Ion Batteries, Kithzia Czarina Gomez

Theses and Dissertations

The following thesis is concentrated on the development of TiO2Sb2O3 composite material through the hydrolysis of TiCl4 to be applied as anode material for lithium-ion batteries. Antimony (Sb) has been a material of interest due to its high capacity and good chemical properties. The TiO2 accommodated the harsh volume expansion that Sb encounters during the alloying process while still preserving the high capacity offered by Sb. Its electrochemical performance exhibited a stabilized capacity of 523 mAhg-1 after reaching 40 cycles with a capacity loss of 2.4% till reaching 100 cycles. High reversible capacity characteristics were present with an initial capacity …


Image Segmentation With Human-In-The-Loop In Automated De-Caking Process For Powder Bed Additive Manufacturing, Vincent Opare Addo Asare-Manu Jul 2023

Image Segmentation With Human-In-The-Loop In Automated De-Caking Process For Powder Bed Additive Manufacturing, Vincent Opare Addo Asare-Manu

Theses and Dissertations

Additive manufacturing (AM) becomes a critical technology that increases the speed and flexibility of production and reduces the lead time for high-mix, low-volume manufacturing. One of the major bottlenecks in further increasing its productivity lies around its post-processing procedures. This work focuses on tackling a critical and inevitable step in powder-bed additive manufacturing processes, i.e., powder cleaning or de-caking. Pressing concerns can be raised with human involvement when performing this task manually. Therefore, a robot-driven automatic powder cleaning system could be an alternative to reducing time consumption and increasing safety for AM operators. However, since the color and surface texture …