Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2011 - 2040 of 30252

Full-Text Articles in Mechanical Engineering

Effects Of Die Type On Mechanical Performance And Failure Behaviors Of Self-Piercing Riveting Joints In Aa5052, Lun Zhao, Amr Monier, Ao Zhang, Liya Li, Ahmed Elkaseer, Zeshan Abbas, Kai Ye Feb 2025

Effects Of Die Type On Mechanical Performance And Failure Behaviors Of Self-Piercing Riveting Joints In Aa5052, Lun Zhao, Amr Monier, Ao Zhang, Liya Li, Ahmed Elkaseer, Zeshan Abbas, Kai Ye

Mechanical Engineering

This study investigates the effects of self-piercing riveting (SPR) die type on the joint quality and failure modes of AA5052 SPR joints. Three die types: flat, pip, and ball-shaped were designed and processed for the SPR process, and 30 riveted specimens were prepared. A 2D axisymmetric finite element (FE) simulation model was established using LS-Dyna to evaluate the impact of each die type. The accuracy of the FE model was validated by comparing simulated joint cross-sections with experimental results. Subsequently, the quality and forming mechanisms of the SPR joints fabricated using each die type were analyzed. Mechanical properties were assessed …


Few-Shot Transfer Learning For Individualized Braking Intent Detection On Neuromorphic Hardware, Nathan A. Lutes, V. Sriram Siddhardth Nedendla, K. Krishnamurthy Feb 2025

Few-Shot Transfer Learning For Individualized Braking Intent Detection On Neuromorphic Hardware, Nathan A. Lutes, V. Sriram Siddhardth Nedendla, K. Krishnamurthy

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work explores use of a few-shot transfer learning method to train and implement a convolutional spiking neural network (CSNN) on a Brain Chip Akida AKD1000 neuromorphic system-on-chip for developing individual-level, instead of traditionally used group-level, models using electroencephalographic data. The efficacy of the method is studied on an advanced driver assist system related task of predicting braking intention. Approach. Data are collected from participants operating an NVIDIA JetBot on a testbed simulating urban streets for three different scenarios. Participants receive a braking indicator in the form of: (1) an audio countdown in a nominal baseline, stress-free environment; (2) an …


Quality Evaluation For Colored Point Clouds Produced By Autonomous Vehicle Sensor Fusion Systems, Colin Schaefer, Zeid Kootbally, Vinh Nguyen Feb 2025

Quality Evaluation For Colored Point Clouds Produced By Autonomous Vehicle Sensor Fusion Systems, Colin Schaefer, Zeid Kootbally, Vinh Nguyen

Michigan Tech Publications

Perception systems for autonomous vehicles (AVs) require various types of sensors, including light detection and ranging (LiDAR) and cameras, to ensure their robustness in driving scenarios and weather conditions. The data from these sensors are fused together to generate maps of the surrounding environment and provide information for the detection and tracking of objects. Hence, evaluation methods are necessary to compare existing and future sensor systems through quantifiable measurements given the wide range of sensor models and design choices. This paper presents an evaluation method to compare colored point clouds, a common fused data type, among two LiDAR-camera fusion systems …


Trpv4 Dominates High Shear-Induced Initial Traction Response And Long-Term Relaxation Over Piezo1, Mohanish Chandurkar, Manli Yang, Majid Rostami, Sangyoon J. Han Feb 2025

Trpv4 Dominates High Shear-Induced Initial Traction Response And Long-Term Relaxation Over Piezo1, Mohanish Chandurkar, Manli Yang, Majid Rostami, Sangyoon J. Han

Michigan Tech Publications

Modulation of endothelial traction is critical for the responses of endothelial cells to fluid shear stress (FSS), which has profound implications for vascular health and atherosclerosis. Previously, we demonstrated that under high FSS, endothelial cells rapidly increase traction forces, followed by relaxation, with traction aligning in the flow direction. In contrast, low shear preconditioning induces a modest short-term increase in traction (min), followed by a secondary long-term (>14 hr) rise, with traction/cells aligning perpendicular to the flow. The upstream mechanosensors driving these responses, however, remain unknown. Here, we sought the roles of Piezo1 and TRPV4 ion channels in shear-induced …


Hemodynamics Of Slip Surfaces For Thrombosis Control In Implanted Cardiovascular Devices, Kieun Choi, Weiguang Yang, On Shun Pak, Jongmin Seo Feb 2025

Hemodynamics Of Slip Surfaces For Thrombosis Control In Implanted Cardiovascular Devices, Kieun Choi, Weiguang Yang, On Shun Pak, Jongmin Seo

Mechanical Engineering Faculty Publications

Percutaneous medical devices are preferred for the treatment of cardiovascular diseases due to their minimal intervention compared to surgery. However, complications such as thrombosis remain significant challenges. This study aims to investigate the hemodynamic effects of slip surfaces on pacemaker leads and coronary stents using computational fluid dynamics under physiological conditions. Two computational models were developed: a venous anatomical model with a pacemaker lead and a coronary artery model with a stent. Slip boundary conditions were applied to these devices, and we quantitatively analyzed critical hemodynamic parameters, including wall shear stress (WSS) and residence time (RT), which are associated with …


Iros 2023 Workshop Report: Draft Guidelines On Manufacturing Procedures, Test Methods And Reporting For Soft Robotics, Robert Baines, Laura Blumenschein, Jennifer Case, Robert Maccurdy, Gina Olson, Andrew Spielberg Feb 2025

Iros 2023 Workshop Report: Draft Guidelines On Manufacturing Procedures, Test Methods And Reporting For Soft Robotics, Robert Baines, Laura Blumenschein, Jennifer Case, Robert Maccurdy, Gina Olson, Andrew Spielberg

School of Mechanical Engineering Working Papers

No abstract provided.


Significance Of Multi-Level Fusion In Multi-Component Fault Diagnosis Under Speed Varying Condition In Rotational Machinery, S. Sowmya, M. Saimurugan, Immanuel A. Edinbarough Feb 2025

Significance Of Multi-Level Fusion In Multi-Component Fault Diagnosis Under Speed Varying Condition In Rotational Machinery, S. Sowmya, M. Saimurugan, Immanuel A. Edinbarough

Informatics and Engineering Systems Faculty Publications

Most well-known challenging effects of identifying multiple defects in a rotational machine when speed is varied, are illustriously inspected by many researchers. However, different fusion logics are evolved in the series of research attempt, but not paid much attention in interrogating it for unsteady speed signals.Addressing this literature void, this paper focusses on multi-level fusion strategy with the help of sensor-centric feature integration and Dempster Shafer’s (D-S) theory of evidence for uncovering multi-faults in bearings, shafts and gears of rotational machines under speed variational condition. Primarily, instantaneous frequency and envelope from the acquired vibration and sound signals of complex system …


Si-Doped Ain Using Pulsed Metalorganic Chemical Vapor Deposition And Doping, Tariq Jamil, Abdullah Al Mamun Mazumder, Mohammod Ali, Jingyu Lin, Hongxing Jiang, Grigory Simin, M. Asif Khan Feb 2025

Si-Doped Ain Using Pulsed Metalorganic Chemical Vapor Deposition And Doping, Tariq Jamil, Abdullah Al Mamun Mazumder, Mohammod Ali, Jingyu Lin, Hongxing Jiang, Grigory Simin, M. Asif Khan

Faculty Publications

In this paper we describe a pulsed metalorganic chemical vapor deposition (MOCVD) Si-doping approach for AlN epilayers over bulk AlN. The Al-rich growth/doping conditions in the pulsed MOCVD process resulted in n-AlN layers with transmission line model currents that were an order higher than for structures on layers that were grown/doped at identical temperatures using the conventional MOCVD process. Our work demonstrated that like the other reported approaches such as UV exposure during growth, the pulsed MOCVD process is also very effective in reducing point defects by the defect quasi-Fermi level-chemical potential control.


Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter Feb 2025

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …


Lustr20 Thermal Profiling Repository Data, Paul Van Susante Feb 2025

Lustr20 Thermal Profiling Repository Data, Paul Van Susante

LuSTR20 Datasets

The PSTDL was a recipient of a 2020 NASA’s Lunar Surface Technology Research grant (LuSTR20) for the development of a lunar prospecting instrument known as the Percussive Hot Cone Penetrometer (PHCP) in combination with Ground Penetrating Radar (GPR). The goal of this project is to produce a science instrument that is capable of probing the lunar surface up to a depth of 1 meter to extract the geotechnical properties of the lunar regolith, identifying the vertical and lateral concentrations of volatiles present.


Potential Effects Of Statistical Complexity Measure In Improving The Fault Diagnosis Performance Under Speed Fluctuations, S. Sowmya, M. Saimurugan, N. Kannan, Immanuel A. Edinbarough Feb 2025

Potential Effects Of Statistical Complexity Measure In Improving The Fault Diagnosis Performance Under Speed Fluctuations, S. Sowmya, M. Saimurugan, N. Kannan, Immanuel A. Edinbarough

Informatics and Engineering Systems Faculty Publications

Many research studies are performed in extracting non-stationary signal properties such as instantaneous frequency (IF) and envelope to diagnose machinery faults under time-varying speed conditions. But accurate IF extraction is difficult from such complex fluctuating signals to identify the faults efficiently. Therefore, this paper proposes the Statistical Complexity Measure (SCM) as a feature that evaluates the randomness and complexity without any additional requirement, providing an outstanding result in multi-component fault detection under speed fluctuations. Primarily, the influence of SCM is proved by ranking the features with the help of the Random Forest (RF) algorithm. The fault classification of individual signal …


High Shear Stress Reduces Erg Causing Endothelial-Mesenchymal Transition And Pulmonary Arterial Hypertension, Tsutomu Shinohara, Jan-Renier Moonen, Yoon Hong Chun, Yannick C. Lee-Yow, Kenichi Okamura, Jason M. Szafron, Jordan Kaplan, Aiqin Cao, Lingli Wang, Weiguang Yang Feb 2025

High Shear Stress Reduces Erg Causing Endothelial-Mesenchymal Transition And Pulmonary Arterial Hypertension, Tsutomu Shinohara, Jan-Renier Moonen, Yoon Hong Chun, Yannick C. Lee-Yow, Kenichi Okamura, Jason M. Szafron, Jordan Kaplan, Aiqin Cao, Lingli Wang, Weiguang Yang

Mechanical Engineering Faculty Publications

Background: Computational modeling indicated that pathological high shear stress (HSS; 100 dyn/cm2) is generated in pulmonary arteries (PAs; 100-500 µm) in congenital heart defects causing PA hypertension (PAH) and in idiopathic PAH with occlusive vascular remodeling. Endothelial-to-mesenchymal transition (EndMT) is a feature of PAH. We hypothesize that HSS induces EndMT, contributing to the initiation and progression of PAH.

Methods: We used the Ibidi perfusion system to determine whether HSS applied to human PA endothelial cells (ECs) induces EndMT when compared with physiological laminar shear stress (15 dyn/cm2). The mechanism was investigated and targeted to prevent PAH in a mouse with …


Effect Of Mg–Nb Oxides On Hydrogen Sorption Kinetics Of Ball-Milled Mgh2, Md. Wasikur Rahman, Muhammad Nurunnabi Siddiquee, Mohammad M. Hossain, M. Jasim Uddin Feb 2025

Effect Of Mg–Nb Oxides On Hydrogen Sorption Kinetics Of Ball-Milled Mgh2, Md. Wasikur Rahman, Muhammad Nurunnabi Siddiquee, Mohammad M. Hossain, M. Jasim Uddin

Mechanical Engineering Faculty Publications

Addition of Mg–Nb oxides (e.g. MgNb2O6, Mg4Nb2O9, and Mg3Nb6O11) ameliorates H2 absorption/desorption kinetics of MgH2 as demonstrated in the current article. H2 desorption and absorption rates of the ball-milled MgH2 are evidently temperature-dependent, which points out that the prior rate increases with increasing temperature (593–673 K) and vice versa. Among the tested samples, MgH2 with Mg3Nb6O11 nanoparticles showed superior performance. The Johnson–Mehl–Avrami equation was employed to construct H2 desorption curves as well as …


Oxidation–Reduction Of Ti-6al-4v In Direct Energy Deposition Subject To Minimum Argon Consumption, Bharadwaja Ragampeta, Prashansa Ragampeta, Todd Sparks, Frank Liou Feb 2025

Oxidation–Reduction Of Ti-6al-4v In Direct Energy Deposition Subject To Minimum Argon Consumption, Bharadwaja Ragampeta, Prashansa Ragampeta, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ti-6Al-4V is a well-known alloy for its low density and excellent corrosion resistance, making it popular in aerospace, marine, medical, and automotive applications. However, at elevated temperatures, the alloy forms oxides, leading to embrittlement. In additive manufacturing, particularly in the direct energy deposition (DED) process, which involves high temperatures, the alloy experiences oxidation. An inert gas chamber provides shielding during the process but limits the size of the manufactured components, and deposition in a vacuum chamber can alter the chemical composition of the alloy. Local shielding is a technique generally used for such applications, but it uses a high volume …


Predicting The High Temperature Deformation Behavior Of Haynes282 By A Dislocation-Density Based Crystal Plasticity Model, Tianju Chen, Huadong Fu, Shujing Dong, Yue Zhou, Yijia Gu, Caizhi Zhou, Ridwan Sakidja Feb 2025

Predicting The High Temperature Deformation Behavior Of Haynes282 By A Dislocation-Density Based Crystal Plasticity Model, Tianju Chen, Huadong Fu, Shujing Dong, Yue Zhou, Yijia Gu, Caizhi Zhou, Ridwan Sakidja

Materials Science and Engineering Faculty Research & Creative Works

Mechanical behavior of Haynes282 is heavily dependent upon the microstructure state, calling for mesoscale model to study the relationship between the underlying microstructure and macroscopic performance. In this work, we employ crystal plasticity finite element method (CPFEM) to explore the deformation mechanisms of Hanyes282 subjected to tensile (short-term) and creep (long-term) tests. Haynes282 is a newly developed Ni-based superalloy, containing relatively low volume fraction (≤20%) of spherical γ′ precipitate phase. A dislocation-density based model is developed to describe the tensile and the creep behavior, where a dimension reduction algorithm is proposed to obtain more accurate inter-particle spacing. Furthermore, dislocation-particle interaction …


A Comprehensive Study Of Cooling Rate Effects On Diffusion, Microstructural Evolution, And Characterization Of Aluminum Alloys, Atiqur Rahman, Sriram Praneeth Isanaka, Frank Liou Feb 2025

A Comprehensive Study Of Cooling Rate Effects On Diffusion, Microstructural Evolution, And Characterization Of Aluminum Alloys, Atiqur Rahman, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Cooling Rate (CR) definitively influences the microstructure of metallic parts manufactured through various processes. Factors including cooling medium, surface area, thermal conductivity, and temperature control can influence both predicted and unforeseen impacts that then influence the results of mechanical properties. This comprehensive study explores the impact of CRs in diffusion, microstructural development, and the characterization of aluminum alloys and the influence of various manufacturing processes and post-process treatments, and it studies analytical models that can predict their effects. It examines a broad range of CRs encountered in diverse manufacturing methods, such as laser powder bed fusion (LPBF), directed energy deposition …


Flow And Heat Transfer Experimental Study For 3d-Printed Solar Receiving Tubes With Helical Fins At Internal Surface, Fouad Haddad, Naznin Nuria Afrin, Jianzhi Li, Peiwen Li, Bharath Pidaparthi, Samy Missoum, Ben Xu Feb 2025

Flow And Heat Transfer Experimental Study For 3d-Printed Solar Receiving Tubes With Helical Fins At Internal Surface, Fouad Haddad, Naznin Nuria Afrin, Jianzhi Li, Peiwen Li, Bharath Pidaparthi, Samy Missoum, Ben Xu

Manufacturing & Industrial Engineering Faculty Publications

3D-printing technology was applied to fabricate novel solar thermal collection tubes that have internal heat transfer enhancement fins and external surfaces with high solar absorptivity and low emissivity due to the ability to use different materials in one tube. Helical fins were selected to introduce circumferential flow and thus minimize the circumferential temperature difference of the tube that receives sunlight on one side. The structures of the helical fins were previously optimized from computational fluid dynamics (CFD) analysis with the objective of low entropy production rate by looking for high heat transfer coefficient and relatively lower pressure loss. High-temperature alloy, …


Introduction To The Special Issue On Verification And Validation Of Source And Propagation Models For Underwater Sounda), Kathleen J. Vigness-Raposa, Klaus Lucke, Michael A. Ainslie, Michele B. Halvorsen, Christ A. F. De Jong, Stanley J. Labak, Martin Siderius Feb 2025

Introduction To The Special Issue On Verification And Validation Of Source And Propagation Models For Underwater Sounda), Kathleen J. Vigness-Raposa, Klaus Lucke, Michael A. Ainslie, Michele B. Halvorsen, Christ A. F. De Jong, Stanley J. Labak, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

This joint Special Issue of JASA and JASA Express Letters focuses on underwater sound source and propagation modelling, both of ambient sound as well as sources of relevance to possible effects of sound on aquatic life, and corresponding acoustical metrics. Combining information on the sound field with information on a dose-effect relationship enables estimation of the potential effects. The Special Issue presents a collection of eighteen articles on the following topics: (1) verification of source and propagation models, (2) validation of source and propagation models, and (3) bioacoustical metrics for assessment of the risk of environmental effects. This special issue …


Development Of A Basilar Membrane-Inspired Mechanical Spectrum Analyzer Using Metastructures For Enhanced Frequency Selectivity, Shantanu H. Chavan, Vijaya Venkata Narasimha Sriram Malladi Jan 2025

Development Of A Basilar Membrane-Inspired Mechanical Spectrum Analyzer Using Metastructures For Enhanced Frequency Selectivity, Shantanu H. Chavan, Vijaya Venkata Narasimha Sriram Malladi

Michigan Tech Publications

This study introduces a mechanical spectrum analyzer (MSA) inspired by the tonotopic organization of the basilar membrane (BM), designed to achieve two critical features. First, it replicates the traveling-wave behavior of the BM, characterized by energy dissipation without reflections at the boundaries. Second, it enables the physical encoding of the wave energy into distinct spectral components. Moving beyond the conventional focus on metamaterial design, this research investigates wave propagation behavior and energy dissipation within metastructures, with particular attention to how individual unit cells absorb energy. To achieve these objectives, a metastructural design methodology is employed. Experimental characterization of metastructure samples …


Co2 Electrolysis Using Metal-Supported Solid Oxide Cells With Infiltrated Pr0.5Sr0.4Mn0.2Fe0.8O3−Δ Catalyst, Boxun Hu, Ka-Young Park, Asia Sarycheva, Robert Kostecki, Fanglin Chen, Michael C. Tucker Jan 2025

Co2 Electrolysis Using Metal-Supported Solid Oxide Cells With Infiltrated Pr0.5Sr0.4Mn0.2Fe0.8O3−Δ Catalyst, Boxun Hu, Ka-Young Park, Asia Sarycheva, Robert Kostecki, Fanglin Chen, Michael C. Tucker

Faculty Publications

Electrochemical conversion of CO2 to CO is demonstrated with symmetric-structured metal supported solid oxide cells (MS-SOC). Perovskite Pr0.5Sr0.4Mn0.2Fe0.8O3−δ (PSMF) and Pr6O11 catalysts were infiltrated into the MS-SOC cathode and anode, using 3 cycles with firing at 850 °C and 8 cycles with firing at 800 °C, respectively. Upon reduction during operation, the perovskite PSMF was transformed to Ruddlesden–Popper structure with a highly efficient electrocatalytic activity. The impact of operating temperature (600–800 °C) and overpotential (0–1.8 V) on the CO2 conversion was investigated. The highest CO2 conversion …


Desktop-Scale Robot Tape Manipulation For Additive Manufacturing, Nahid Tushar, Rencheng Wu, Yu She, Wenchao Zhou, Shou Wang Jan 2025

Desktop-Scale Robot Tape Manipulation For Additive Manufacturing, Nahid Tushar, Rencheng Wu, Yu She, Wenchao Zhou, Shou Wang

Mechanical Engineering Faculty Publications and Presentations

Advancements in additive manufacturing and robotic automation have enabled diverse fabrication techniques using various materials. However, small-scale tape placement for three-dimensional (3D) printing remains underexplored, with most research focused on large-scale composite manufacturing using carbon fiber prepreg tapes. This work presents an innovative, automated, and cost-effective tape placement system that extends traditional methods beyond carbon fiber prepreg. We developed a customized tape print module (TPM) integrated with a robotic arm, enabling precise and versatile tape placements. Our system supports non-linear toolpaths, complex patterns, and controllable placements on multi-plane surfaces, creating overhangs without support. We demonstrate circuit printing with copper tape …


Stabilizing A Bio-Inspired Rotating Empennage Fighter Aircraft In Multiple Trim Scenarios, Benjamin C. Moulton, Matthew W. Harris, Douglas F. Hunsaker Jan 2025

Stabilizing A Bio-Inspired Rotating Empennage Fighter Aircraft In Multiple Trim Scenarios, Benjamin C. Moulton, Matthew W. Harris, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

This paper considers the problem of stabilizing a bio-inspired fighter aircraft at its Air Combat Maneuver Condition in steady level and coordinated-turning flight. The aircraft equations of motion are linearized, and an infinite-horizon linear quadratic regulator design is conducted. The open-loop system is unstable in the short period and Dutch roll modes. This is mitigated in the closed-loop system, which is analyzed in the time and frequency domains. Included in the simulation dynamics are first-order actuator models, actuator deflection limits, and actuator rate limits. These are particularly important for this bio-inspired aircraft because control actuation requires rotation of the empennage, …


System Dynamics For Manufacturing: Supply Chain Simulation Of Hemp-Reinforced Polymer Composite Manufacturing For Sustainability, Gurinder Kaur, Ronald Kander Jan 2025

System Dynamics For Manufacturing: Supply Chain Simulation Of Hemp-Reinforced Polymer Composite Manufacturing For Sustainability, Gurinder Kaur, Ronald Kander

School of Design and Engineering Papers

Supply chain management (SCM) involves complexities and uncertainties in the flow of goods and services from raw materials to end users. Inaccurate estimation of raw materials, labor, or equipment can lead to financial losses and environmental impacts. This study explores the application of system dynamics modeling (SDM) in manufacturing hemp-reinforced polymer composites (HRPC) to optimize resource usage. Using SDM software STELLA® (Version 3.7.3), selected for its affordability and features, the research demonstrates how system dynamics (SD) can enhance sustainability by minimizing materials, labor, and equipment, reducing energy consumption. A literature review identified a gap in existing research, as we …


Influence Of Process Parameter And Build Rate Variations On Defect Formation In Laser Powder Bed Fusion Ss316l, Tasrif Ul Anwar, Patrick Merighe, Rahul Reddy Kancharla, Boopathy Kombaiah, Nadia Kouraytem Jan 2025

Influence Of Process Parameter And Build Rate Variations On Defect Formation In Laser Powder Bed Fusion Ss316l, Tasrif Ul Anwar, Patrick Merighe, Rahul Reddy Kancharla, Boopathy Kombaiah, Nadia Kouraytem

Mechanical and Aerospace Engineering Student Publications and Presentations

Laser powder bed fusion (LPBF) is an additive manufacturing process that has gained interest for its material fabrication due to multiple advantages, such as the ability to print parts with small feature sizes, good mechanical properties, reduced material waste, etc. However, variations in the key process parameters in LPBF may result in the instantiation of porosity defects and variation in build rate. Particularly, volumetric energy density (VED) is a variable that encapsulates a number of those parameters and represents the amount of energy input from the laser source to the feedstock. VED has been traditionally used to inform the quality …


Optimization And Dft Study For Boosted Electooxidation Of Formic Acid At Niox Modified Pt Using Urea Derivatives As Blending Fuels, Aya Saada Jan 2025

Optimization And Dft Study For Boosted Electooxidation Of Formic Acid At Niox Modified Pt Using Urea Derivatives As Blending Fuels, Aya Saada

Biochemical Engineering

This paper addresses the enhancement of formic acid electrooxidation (FAO) at Pt and Pt-NiOx nanoparticles based-catalysts assisted with urea derivatives as blending fuels. Blending formic acid with various ratios of urea derivatives showed noticeable enhancements of FAO as demonstrated by a favorable negative shift of its onset potential (Eonset) and increase of its peak current density concurrently with suppression of the amount of CO poisoning reaction intermediate. Among all the used derivatives, phenyl urea (PU) showed superior enhancing effect towards the direct FAO with a minimal CO formation together with a favorable negative shift of Eonset by 150 mV. The …


Direct Graphene Growth On Low-Alloy And Mild Steel Surfaces Controlled By Carbon Solubility And Surface Microstructural Transformations During Chemical Vapor Deposition, Kaleb Hood, Nam Nguyen, Sebastian Lara, Adan Velasquez, Samuel Olson, Yi Xia, Jun Jiao Jan 2025

Direct Graphene Growth On Low-Alloy And Mild Steel Surfaces Controlled By Carbon Solubility And Surface Microstructural Transformations During Chemical Vapor Deposition, Kaleb Hood, Nam Nguyen, Sebastian Lara, Adan Velasquez, Samuel Olson, Yi Xia, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

This study demonstrates for the first time, graphene grown directly on the iron-rich surfaces of bulk 8620 low-alloy and 1018 mild steel by chemical vapor deposition, a key step toward developing thin graphene coatings with strong graphene-steel bonding. Low growth temperatures of 660 °C–680 °C, were used to manipulate the steel's carbon solubility, confining carbon diffusion and microstructural transformations to the surface regions, with the bulk relatively unchanged. For 1018, a growth temperature of 680 °C resulted in a multilayer graphene coating with 80 % coverage. The alloying elements in 8620 improved graphene formation by influencing the surface microstructure transformations …


Long-Range Inertia Prediction Considering Contemporary Evolution Of Power Grid Networks, Peter M. Makolo Jan 2025

Long-Range Inertia Prediction Considering Contemporary Evolution Of Power Grid Networks, Peter M. Makolo

Tanzania Journal of Engineering and Technology (TJET)

Reduced network inertia due to high penetration levels of non-synchronous generators in modern power systems is becoming a pressing issue. As a result, very quick inertial responses are observed after contingency events in networks. Due to quick inertial responses, there is a practically very limited time interval for control actions in real-time. Thus, system operators need to understand the prior inertia values to plan, control, and operate the network securely. Long-range forecasting of the network's inertia values, in contrast to short-range forecasting techniques, can pinpoint when the network is most likely to be vulnerable in a reasonable time ahead. Thus, …


Circular Dichroism In Achiral Metasurfaces Induced By Spatially Selective Coupling With Molecules, Baojuan Han, Xiaodong Yang, Jie Gao Jan 2025

Circular Dichroism In Achiral Metasurfaces Induced By Spatially Selective Coupling With Molecules, Baojuan Han, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Achiral metasurfaces with near-field optical chirality have attracted great attention in molecular sensing and chiral emission control. Here, the circular dichroism (CD) response of an achiral metasurface induced by spatially selective coupling with polymethyl methacrylate (PMMA) molecules is demonstrated. A designed achiral metasurface with a V-shaped resonator exhibits large optical chirality with a strongly dissymmetric distribution under circular polarization. By introducing a PMMA molecule layer on top of the metasurface, which covers the area with large optical chirality, CD in absorption of 0.38 and a dissymmetric factor of optical chirality gc of 0.16 are obtained. Furthermore, an analysis of the …


Identifying The Effect Of Architecture Morphology On Wind Fields And Pm2.5 Dispersion At The Urban Block Scale Via A Combined Scheme, Bin Guo, Lu Li, Xiaowei Zhu, Zheng Wang, Miaoyi Chen, Lin Pei, Tengyue Guo Jan 2025

Identifying The Effect Of Architecture Morphology On Wind Fields And Pm2.5 Dispersion At The Urban Block Scale Via A Combined Scheme, Bin Guo, Lu Li, Xiaowei Zhu, Zheng Wang, Miaoyi Chen, Lin Pei, Tengyue Guo

Mechanical and Materials Engineering Faculty Publications and Presentations

This study explores the potential of architecture morphology to mitigate PM2.5 pollution through enhanced urban ventilation. Despite the recognized influence of building designs on wind and air pollution distribution at the urban block scale, specific mechanisms remain poorly understood. To address this gap, we have developed an integrative approach combining in-situ observations, Geographic Information System (GIS), Remote Sensing (RS), Computational Fluid Dynamics (CFD), and statistical modeling. Here, CFD simulates the flow field and PM2.5 dispersion, using in-situ observations for turbulence model selection. GIS quantify architecture morphology parameters to establish accurate CFD boundary conditions, ensuring simulations reflect real-world conditions and precise …


Advancing Prosthetic Technology: 3d-Printed Robotic Arm With Micro Linear Actuators, Vu Tran, Nathan Reed, Mahdi Yazdanpour Jan 2025

Advancing Prosthetic Technology: 3d-Printed Robotic Arm With Micro Linear Actuators, Vu Tran, Nathan Reed, Mahdi Yazdanpour

Posters-at-the-Capitol

The increasing demand for affordable and accessible prosthetic solutions has driven innovation in the field of robotics. In this project, we present the design and development of a 3D-printed robotic prosthetic arm aimed at addressing the challenges faced by individuals with upper limb amputations. Our prosthetic arm utilizes five micro linear actuators to achieve precise and naturalistic movement. The design of the prosthetic arm prioritizes affordability and accessibility, with a focus on leveraging 3D printing technology to reduce manufacturing costs and enable customization. The use of micro linear actuators offers advantages in terms of compactness, lightweight construction, and efficient power …