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Articles 991 - 1020 of 20603

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Numerical Assessment Of Shot Peening Contribution To The Fatigue Strength Of Gear Tooth Root, Gurutz Cortabitarte Laucirica, Xuban Telleria, Iñigo Llavori, Ibai Ulacia, Miren Larrañaga, Jon Ander Esnaola Sep 2025

Numerical Assessment Of Shot Peening Contribution To The Fatigue Strength Of Gear Tooth Root, Gurutz Cortabitarte Laucirica, Xuban Telleria, Iñigo Llavori, Ibai Ulacia, Miren Larrañaga, Jon Ander Esnaola

15th International Conference on Shot Peening

Gears are commonly treated with shot peening (SP) and/or case hardening to enhance fatigue resistance. However, their effects are often conservatively assessed using standardized methods, which can limit their optimal application in industrial components. Particularly, the effect of SP over case-hardened gears remains insufficiently explored. Therefore, the present study evaluates the contribution of SP on single tooth bending fatigue (STBF) strength of raw and case-hardened spur gears, commonly used in automotive and heavy machinery industries. In the study four conditions are addressed: (i) untreated, (ii) case-hardened, (iii) shot-peened, and (iv) case-hardened and shot-peened. First, the residual stress field of the …


Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy Sep 2025

Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy

15th International Conference on Shot Peening

The deep penetration of laser peening (LP) and retention of residual stress at high temperature by LP is significant in improving fatigue life and strength of superalloys exposed to high temperature and corrosion. Single crystal CMSX-4, was evaluated for stress relaxation and both fatigue life and fatigue strength of material that was LP-treated compared to non-LP and shot-peened (SP) specimens. LP was done with multiple layers using a 20 J/pulse laser where the laser high energy enabled using a 5 mm spot size on the metal surface. Stress measurements by the slitting technique showed the plastic penetration depth exceeded SP …


Nonlinear Analytical Models Of The Seismically Isolated ``Frame-Boiler'' System With Cantilever-Type Hysteresis Dampers, Aleksandr Mikhailovich Anushchenko, Dmitrii Evgenievich Bondarev, Aleksandr Yurievich Schukin Sep 2025

Nonlinear Analytical Models Of The Seismically Isolated ``Frame-Boiler'' System With Cantilever-Type Hysteresis Dampers, Aleksandr Mikhailovich Anushchenko, Dmitrii Evgenievich Bondarev, Aleksandr Yurievich Schukin

Journal of Sustainable Construction Materials and Technologies

This study shows results of development of the ``frame-boiler'' system with hysteresis dampers analytical model. Hysteresis dampers are used as boiler antiseismic bracing. It is noted that simplified analytical models are necessary at the stage of preliminary iterative calculations, when a CAE-modeling is impractical due to significant time costs. The authors have proposed 2 options of analytical models: 2-mass model and 3-mass model. The differential equations of motion for each model are written below. The results of the calculation for seismic impacts are compared with the finite element model. It is shown that 3-mass model gives good match of results …


Advancing Sustainable Structural Solutions: Hemp Fiber-Reinforced Polymer (Hfrp) Reinforcement Bars For Concrete Applications Through Material Selection, Simulation, And Pathways For Future Development, Thomas Cadenazzi, Busra Keles Sep 2025

Advancing Sustainable Structural Solutions: Hemp Fiber-Reinforced Polymer (Hfrp) Reinforcement Bars For Concrete Applications Through Material Selection, Simulation, And Pathways For Future Development, Thomas Cadenazzi, Busra Keles

Journal of Sustainable Construction Materials and Technologies

This paper investigates innovative Hemp Fiber-Reinforced Polymer (HFRP) rebars as a sustainable alternative to conventional Carbon Steel (CS) and Glass Fiber-Reinforced Polymer (GFRP) rebars used as reinforcement in concrete structures. The feasibility of HFRP rebars is assessed, focusing on mechanical properties and sustainability advantages. A virtual tensile test on a modeled M19 HFRP rebar, conducted using Autodesk's Fusion 360, demonstrates tensile strength comparable to CS 235 and greater environmental sustainability than GFRP, despite a slight reduction in stiffness. The study also considers the potential of graphene fiber integration to enhance mechanical properties, underscoring HFRP's adaptability. Findings suggest that HFRP rebars, …


Overcoming Variable Illumination In Photovoltaic Snow Monitoring: A Real-Time Robust Drone-Based Deep Learning Approach, Amna Mazen, Ashraf Saleem, Kamyab Yazdipaz, Ana Dyreson Sep 2025

Overcoming Variable Illumination In Photovoltaic Snow Monitoring: A Real-Time Robust Drone-Based Deep Learning Approach, Amna Mazen, Ashraf Saleem, Kamyab Yazdipaz, Ana Dyreson

Michigan Tech Publications

Snow accumulation on photovoltaic (PV) panels can cause significant energy losses in cold climates. While drone-based monitoring offers a scalable solution, real-world challenges like varying illumination can hinder accurate snow detection. We previously developed a YOLO-based drone system for snow coverage detection using a Fixed Thresholding segmentation method to discriminate snow from the solar panel; however, it struggled in challenging lighting conditions. This work addresses those limitations by presenting a reliable drone-based system to accurately estimate the Snow Coverage Percentage (SCP) over PV panels. The system combines a lightweight YOLOv11n-seg deep learning model for panel detection with an adaptive image …


Performance Of A Two-Body Wave Energy Converter With An Annular Heave Plate, Raj Tamakuwala, Muhammad Usman, Nathan Tom, Hassan Masoud Sep 2025

Performance Of A Two-Body Wave Energy Converter With An Annular Heave Plate, Raj Tamakuwala, Muhammad Usman, Nathan Tom, Hassan Masoud

Michigan Tech Publications

We theoretically examine the performance of a two-body wave energy converter (WEC) featuring a floating sphere and a submerged annular heave plate, connected by a power take-off (PTO) system. Utilising linear wave theory, we derive the system's frequency-domain response to regular plane waves and analyse the impact of varying disk porosity on power generation. Our results suggest that annular disks can enhance power extraction efficiency in various cases compared with solid heave plates. Additionally, permeable plates can broaden operational conditions by reducing oscillation amplitudes and decreasing the mechanical strain on the PTO system without substantially compromising the power conversion efficiency. …


Comparative Analysis Of Belt-Slider Pan Configurations On The Power Consumption Of Belted Conveyor Systems, Asib Ridwan Sep 2025

Comparative Analysis Of Belt-Slider Pan Configurations On The Power Consumption Of Belted Conveyor Systems, Asib Ridwan

Student Theses and Dissertations

Conveyor systems are widely used in industrial applications for material handling, but their high energy consumption remains a significant challenge. This study investigated the influence of different belt-slider pan configurations on conveyor power consumption, aiming to optimize efficiency while minimizing energy losses. Three types of slider pans; mild steel, galvanized steel, and powder-coated steel, were analyzed under controlled experimental conditions to determine the motor torque and power consumption of a test conveyor system under various loading conditions. Torque and power values were derived, plotted, and comparatively analyzed across all configurations to determine performance differences. Static friction coefficients of each type …


Development Of An Instrumented Test System To Evaluate Mechanical Characteristics Of Belted Conveyor Systems, Coleman Emerson Wilson Sep 2025

Development Of An Instrumented Test System To Evaluate Mechanical Characteristics Of Belted Conveyor Systems, Coleman Emerson Wilson

Student Theses and Dissertations

The use of conveyor systems within industrial and warehouse settings gives the ability for increased productivity and increased speed of moving objects. As in many settings, the use of these conveyor systems requires large amounts of continuous runtime, and the ability to save even small amounts of energy over a large period can create large improvements in the total overhead cost of running the facility. Research into the ability to characterize the components within a conveyor system gives the ability to identify sources of large amounts of wasted energy and quantify these losses. There is a need to quantify the …


Engineering And Technology, Fred Haan Sep 2025

Engineering And Technology, Fred Haan

University Faculty Publications and Creative Works

9/21/2025 for the event, Integration of Faith and Learning, at University Pelita Harapan in Jakarta, Indonesia


Advanced Microstructured Batio3-Embedded Pvdf–Hfp/Peo Film For Enhanced Triboelectric Interface In Self-Sufficient Energy Generation And Sensing, Rigobert Ybarra, Diego De Leon, Michael Moreno, Cesar Sanchez, Fernando Viesca, Kevin Alejandro, Shishir Timilsena, Nicholas Dimakis, Joseph H. Dumont, Tommy Rockward, Tarik J. Dickens, Md. Wasikur Rahman, Mohammed Jasim Uddin Sep 2025

Advanced Microstructured Batio3-Embedded Pvdf–Hfp/Peo Film For Enhanced Triboelectric Interface In Self-Sufficient Energy Generation And Sensing, Rigobert Ybarra, Diego De Leon, Michael Moreno, Cesar Sanchez, Fernando Viesca, Kevin Alejandro, Shishir Timilsena, Nicholas Dimakis, Joseph H. Dumont, Tommy Rockward, Tarik J. Dickens, Md. Wasikur Rahman, Mohammed Jasim Uddin

Mechanical Engineering Faculty Publications

The global reliance on fossil fuels and natural gas has largely dominated the energy production field, but due to finite resource depletion and escalating greenhouse gas emissions, the immediate exploration of sustainable energy alternatives to mitigate climate change and ensure resource security has been a major concern. There has been extensive research into other more renewable methods of energy production, such as wind and hydropower. Of these current energy generation types, there are many areas of untapped potential from the mechanical movements generated ambiently not only in the large scale of power generation but also on a smaller scale. The …


Comparative Analysis Of Life Cycle Assessment Of Traditional And Contemporary Timber Buildings, Sadık Akşar, Gökçe Tuna Sep 2025

Comparative Analysis Of Life Cycle Assessment Of Traditional And Contemporary Timber Buildings, Sadık Akşar, Gökçe Tuna

Journal of Sustainable Construction Materials and Technologies

Wood has long been used as a primary building material, but with the Industrial Revolution and the spread of multi-story structures, its structural limitations became evident. In the 21st century, engineered timber products have reintroduced wood as a sustainable alternative, offering advantages such as lightness, rapid assembly, and recyclability. At the same time, buildings are responsible for significant environmental impacts, making assessment methods essential. Life Cycle Assessment (LCA) is one of the most widely used tools for evaluating these impacts across all stages of a building’s life cycle. This study applies LCA to timber construction systems, focusing on both traditional …


Sustainable Paving Block Development: Utilizing Rejected Coal As Filler And Assessing Its Impact On Paving Block’S Properties, Siti Nikmatin, Allen Kurniawan, Heriansyah Putra, Rima Fitria Adiati, Riawan Ma’Ruf, Dwi Arso Yedi Irwanto Sep 2025

Sustainable Paving Block Development: Utilizing Rejected Coal As Filler And Assessing Its Impact On Paving Block’S Properties, Siti Nikmatin, Allen Kurniawan, Heriansyah Putra, Rima Fitria Adiati, Riawan Ma’Ruf, Dwi Arso Yedi Irwanto

Journal of Sustainable Construction Materials and Technologies

This study investigated the potential use of rejected coal as a fine aggregate filler in paving block production. Comprehensive characterization of the rejected coal was conducted, including toxicity, physical, chemical, and mineralogical analyses of the coal. The results showed that the rejected coal met environmental safety standards (TCLP) and had suitable properties as an aggregate. Paving blocks were produced by incorporating different proportions of rejected coal fillers and were tested for compressive strength, water absorption, and density. The optimal mix with 35% rejected coal filler as a replacement of stone ash achieved a compressive strength of 14.61 MPa, water absorption …


Numerical Comparative Study Of The Thermal Performance And Load-Bearing Capacity Of Hollow Clay Bricks Used In Construction In Libya, Osama Lawej, Mahmoud Ahmed, Ismael Ehtiwesh Sep 2025

Numerical Comparative Study Of The Thermal Performance And Load-Bearing Capacity Of Hollow Clay Bricks Used In Construction In Libya, Osama Lawej, Mahmoud Ahmed, Ismael Ehtiwesh

Journal of Sustainable Construction Materials and Technologies

The optimization of structural and thermal performance in building components is a key challenge in sustainable construction, particularly in hot climate regions like Libya. Hollow clay bricks are widely used due to their local availability and affordability; however, their internal geometry is often not optimized for thermal resistance or mechanical integrity. This study addresses this gap by numerically investigating the effect of cavity geometry on the load-bearing capacity and thermal insulation performance of hollow clay bricks. Three configurations were analyzed, including two commercial designs from the Libyan market and a newly proposed arched cavity design. Finite Element Method (FEM) simulations …


Developing A Modular Circular Wall Over-Clad System For Facade Thermal Upgrade In Deep Energy Retrofit, Patrick Daly Sep 2025

Developing A Modular Circular Wall Over-Clad System For Facade Thermal Upgrade In Deep Energy Retrofit, Patrick Daly

Journal of Sustainable Construction Materials and Technologies

The EU has implemented several policy and legislative initiatives aimed at decarbonisation and circularity transition of the Built Environment including a strategy for large scale renovation of the building / housing stock. Modularised construction solutions are argued to be a potential acceleration pathway toward this objective. Yet there remains issues and challenges in implementing such strategies in a complex and heterogeneous stock and sector. This research investigates this decarbonisation pathway, examining the feasibility and potential of applying a modularised construction over-clad system, based on advanced circularity, in the deep energy retrofit of social housing. The research is based on a …


Tissue-Like Fracture Toughness And Stress–Relaxation Ability In Pva-Agar-Based Hydrogels For Biomedical Applications, Ismael Lamas Jr., Bhuvana L. Chandrashekar, Cláudia C. Biguetti, Mohammad R. Islam Sep 2025

Tissue-Like Fracture Toughness And Stress–Relaxation Ability In Pva-Agar-Based Hydrogels For Biomedical Applications, Ismael Lamas Jr., Bhuvana L. Chandrashekar, Cláudia C. Biguetti, Mohammad R. Islam

Mechanical Engineering Faculty Publications

Soft tissues exhibit remarkable stretchability, fracture toughness, and stress–relaxation ability. They possess a large water content to support cellular processes. Mimicking such a combination of mechanical and physical properties in hydrogels is important for tissue engineering applications but remains challenging. This work aims to develop a hydrogel that can combine excellent mechanical properties with cellular viability. The research focused on polyvinyl alcohol (PVA)/agar double-network (DN) hydrogels, fabricated by thermal gelation and freeze–thawing methods. Their mechanical properties were characterized through tension, compression, fracture, and stress–relaxation tests, and their cellular viability was measured through cytotoxicity tests. The results show that the PVA/agar …


Effect Of Gelam Wood And Rice Husk Composition With Molding Pressure On The Combustion Performance Of Biopellets, Rachmat Subagyo, Rudi Siswanto, Ma’Ruf Ma’Ruf, Mastiadi Tamjidillah, Abdul Ghofur, Femiana Gapsari, M. Zainul Rusdi, Azie Aprianto, Wardoyo Wardoyo, Naila Salsabila Sep 2025

Effect Of Gelam Wood And Rice Husk Composition With Molding Pressure On The Combustion Performance Of Biopellets, Rachmat Subagyo, Rudi Siswanto, Ma’Ruf Ma’Ruf, Mastiadi Tamjidillah, Abdul Ghofur, Femiana Gapsari, M. Zainul Rusdi, Azie Aprianto, Wardoyo Wardoyo, Naila Salsabila

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates the effects of gelam wood (Melaleuca leucadendron) and rice husk composition in biopellet production, focusing on compaction pressures of 60, 80, and 100 kg/cm². Five biomass ratios (G100–RH0, G80–RH20, G60–RH40, G50–RH50, G0–RH100) were tested for moisture, ash, fixed carbon, volatile matter, calorific value, ignition time, burning rate, and combustion temperature. Results showed that moisture content ranged from 0.98% (G0–RH100, 60 kg/cm²) to 12.28% (G100–RH0, 80 kg/cm²), while ash content varied between 2.47% (G100–RH0, 60 kg/cm²) and 20.93% (G0–RH100, 80 kg/cm²). The highest calorific value reached 3968 cal/g (G100–RH0, 60–80 kg/cm²), though below the SNI 8675:2018 minimum of …


Spatiotemporal Deep Learning To Forecast Storm Surge Water Levels And Storm Trajectory: Case Study Hurricane Harvey, Junqin Hou, Muhammad K. Akbar, Manar D. Samad, Lizhi Ouyang Sep 2025

Spatiotemporal Deep Learning To Forecast Storm Surge Water Levels And Storm Trajectory: Case Study Hurricane Harvey, Junqin Hou, Muhammad K. Akbar, Manar D. Samad, Lizhi Ouyang

Mechanical and Manufacturing Engineering Faculty Research

No abstract provided.


Effect Of A Small Control Rod On The Aerodynamic Forces And Wake Structure Of Side-By-Side Cylinders At Moderate Reynolds Number, M. M. Mosallem Sep 2025

Effect Of A Small Control Rod On The Aerodynamic Forces And Wake Structure Of Side-By-Side Cylinders At Moderate Reynolds Number, M. M. Mosallem

Journal of Engineering Research

The unsteady wake interaction between two side-by-side circular cylinders often leads to significant vortex shedding and fluctuating aerodynamic forces. This numerical study investigates the effect of a small passive control rod with a rod-to-cylinder diameter ratio d/D = 0.07 on the wake dynamics and aerodynamic forces of two side-by-side circular cylinders. Two configurations are explored: one where the control rod is placed directly behind the cylinders (x/D = 0), and another where it is located downstream (x/D = 0.5). The two cylinders are arranged with a center-to-center spacing ratio T/D = 1.25. The simulations were …


Employing Machine Learning Regression Models For Performance Prediction Of A Two-Stage Solar Dryer, Hany El-Ghaish, Ahmed Aman, Mohamed Abdelgaied Sep 2025

Employing Machine Learning Regression Models For Performance Prediction Of A Two-Stage Solar Dryer, Hany El-Ghaish, Ahmed Aman, Mohamed Abdelgaied

Journal of Engineering Research

The present manuscript aims to examine the application of artificial intelligence techniques to predict the performance of a two-stage solar dryer system equipped with preheating via two solar air collectors. Three machine learning algorithms, namely Linear Regression, k-Nearest Neighbors, and Multilayer Perceptron, were developed, trained, and evaluated on experimental data to identify the most accurate model for predicting the system's performance throughout the year. The dataset undergoes a preprocessing step including temporal linear augmentation, z-score normalization, and second-degree polynomial feature expansion. The evaluation process utilized several performance indices, including mean square error, mean absolute error, mean absolute percentage error, and …


Design And Implementation Of A Smart Solar Tracking System Using Hydraulic Actuation, Bassem Nashaat Zakher, Mahmoud M. Ramzi, Kirolos A. Amin Sep 2025

Design And Implementation Of A Smart Solar Tracking System Using Hydraulic Actuation, Bassem Nashaat Zakher, Mahmoud M. Ramzi, Kirolos A. Amin

Journal of Engineering Research

This research presents the design and implementation of a smart single-axis solar tracking system that introduces a novel integration of hydraulic actuation with minimalistic sensor control. Unlike traditional trackers that rely on multiple light sensors and complex mechanical setups, the proposed system uses a simplified control mechanism driven by a single-point light detection strategy to maintain panel alignment with the sun. The core innovation lies in replacing motor-driven tracking mechanisms with a hydraulic actuator, offering smoother, more durable movement with reduced maintenance. Additionally, the system integrates smart monitoring via Arduino, enabling real-time data processing and decision-making without relying on costly …


Transparent Eeg Analysis: Leveraging Autoencoders, Bi-Lstms, And Shap For Improved Neurodegenerative Diseases Detection, Badr Mouazen, Ahmed Bendaouia, Omaima Bellakhdar, Khaoula Laghdaf, Aya Ennair, El Hassan Abdelwahed, Giovanni De Marco Sep 2025

Transparent Eeg Analysis: Leveraging Autoencoders, Bi-Lstms, And Shap For Improved Neurodegenerative Diseases Detection, Badr Mouazen, Ahmed Bendaouia, Omaima Bellakhdar, Khaoula Laghdaf, Aya Ennair, El Hassan Abdelwahed, Giovanni De Marco

Manufacturing & Industrial Engineering Faculty Publications

Highlights

  • Novel hybrid architecture: Combined autoencoders with bidirectional LSTM networks for enhanced EEG signal classification, achieving 98% accuracy in distinguishing AD, FTD, and healthy controls.

  • Explainable AI integration: Implemented SHAP (SHapley Additive exPlanations) framework to enhance model transparency and identify entropy as the most influential feature for neurodegenerative disease detection.

  • Optimal temporal segmentation: Demonstrated that 5-s EEG windows with 50% overlap provide the best balance between classification accuracy and computational efficiency.

  • Comprehensive feature extraction: Utilized Power Spectral Density (PSD) analysis across standard frequency bands (Delta, Theta, Alpha, Beta, Gamma) following autoencoder-based dimensionality reduction.

  • Superior performance validation: Outperformed traditional machine learning …


Self-Organization In Metal Plasticity: An Ilg Update †, Avraam Konstantinidis, Konstantinos Spiliotis, Amit Chattopadhyay, Elais C. Aifantis Sep 2025

Self-Organization In Metal Plasticity: An Ilg Update †, Avraam Konstantinidis, Konstantinos Spiliotis, Amit Chattopadhyay, Elais C. Aifantis

Michigan Tech Publications

In a 1987 article of the last author dedicated to the memory of a pioneer of classical plasticity Aris Philips of Yale, the last author outlined three examples of self-organization during plastic deformation in metals: persistent slip bands (PSBs), shear bands (SBs) and Portevin Le Chatelier (PLC) bands. All three have been observed and analyzed experimentally for a long time, but there was no theory to capture their spatial characteristics and evolution in the process of deformation. By introducing the Laplacian of dislocation density and strain in the standard constitutive equations used for these phenomena, corresponding mathematical models and nonlinear …


Energy-Aware Optimal Reconfiguration Of A Heterogeneous Connected And Automated Vehicle Cohort On A Limited-Access Highway, Pruthwiraj Santhosh, Darrell Robinette, Daniel Knopp, Jeffrey Naber, Jungyun Bae Sep 2025

Energy-Aware Optimal Reconfiguration Of A Heterogeneous Connected And Automated Vehicle Cohort On A Limited-Access Highway, Pruthwiraj Santhosh, Darrell Robinette, Daniel Knopp, Jeffrey Naber, Jungyun Bae

Michigan Tech Publications

This paper presents an optimized vehicular reordering methodology designed to minimize energy consumption within heterogeneous cohorts operating at constant velocity on limited-access highways. The approach addresses the challenge of optimizing vehicle sequencing by considering both aerodynamic drag reduction benefits and the energy costs of reconfiguring a cohort from a stochastic initial state. This study provides empirical validation through on-road vehicle tests, demonstrating significant energy savings, achieving up to 10% reduction in axle energy for optimally configured cohorts compared to independent operation. A System of Systems (SoS) simulation environment, integrating micro-traffic, validated powertrain, and aerodynamic drag reduction models, was developed to …


Ferric Metal-Organic Frameworks (Mofs)-Based Electrospinning Fibers For Supercapacitors, Samar A. Salim, Hani Nasser Abdelhamid Sep 2025

Ferric Metal-Organic Frameworks (Mofs)-Based Electrospinning Fibers For Supercapacitors, Samar A. Salim, Hani Nasser Abdelhamid

Nanotechnology Research Centre

Ferric-based metal-organic frameworks (Fe-MOFs) were synthesized and incorporated into poly(methyl methacrylate) (PMMA) using electrospinning to produce PMMA_Fe-MOF nanofibers. The materials were analyzed using X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). The electrospun materials were directly integrated into nickel foam (NF) electrodes for energy storage applications, e.g., supercapacitors. The electrochemical performance was assessed using cyclic voltammetry (CV), galvanostatic charge-discharge curves (GCDC), linear sweep voltammetry (LSV), and electrochemical potentiokinetic reactivation (EPR). The PMMA_Fe-MOF electrodes exhibited outstanding capacitive performance, achieving specific capacitances of up to 1017.5 F/g at 1 A/g for the 2.5 % Fe-MOF …


Underwater Acoustic Integrated Sensing And Communication: A Spatio-Temporal Freshness For Intelligent Resource Prioritization, Ananya Hazarika, Mehdi Rahmati Sep 2025

Underwater Acoustic Integrated Sensing And Communication: A Spatio-Temporal Freshness For Intelligent Resource Prioritization, Ananya Hazarika, Mehdi Rahmati

Electrical and Computer Engineering Faculty Publications

Underwater acoustic communication faces significant challenges including limited bandwidth, high propagation delays, severe multipath fading, and stringent energy constraints. While integrated sensing and communication (ISAC) has shown promise in radio frequency systems, its adaptation to underwater environments remains challenging due to the unique acoustic channel characteristics and the inadequacy of traditional delay-based performance metrics that fail to capture the spatio-temporal value of information in dynamic underwater scenarios. This paper presents a comprehensive underwater ISAC framework centered on a novel Spatio-Temporal Information-Theoretic Freshness metric that fundamentally transforms resource allocation from delay minimization to value maximization. Unlike conventional approaches that treat all …


A Polar Turbulence Invariant Map With Applicability To Realisable Machine Learning Turbulence Models, James G. Wnek, Christopher Schrock, Eric M. Wolf, Mitch Wolff Sep 2025

A Polar Turbulence Invariant Map With Applicability To Realisable Machine Learning Turbulence Models, James G. Wnek, Christopher Schrock, Eric M. Wolf, Mitch Wolff

Mechanical and Materials Engineering Faculty Publications

Invariant maps are a useful tool for turbulence modelling, and the rapid growth of machine learning-based turbulence modelling research has led to renewed interest in them. They allow different turbulent states to be visualised in an interpretable manner and provide a mathematical framework to analyse or enforce realisability. Current invariant maps, however, are limited in machine learning models by the need for costly coordinate transformations and eigendecomposition at each point in the flow field. This paper introduces a new polar invariant map based on an angle that parametrises the relationship of the principal anisotropic stresses, and a scalar that describes …


Experimental Study Of Gas-Dynamic Heating In Hartmann-Sprenger Tubes For Rocket Engine Ignition, Jacob T. Huff Sep 2025

Experimental Study Of Gas-Dynamic Heating In Hartmann-Sprenger Tubes For Rocket Engine Ignition, Jacob T. Huff

Master's Theses

Ignition systems for chemical rocket engines typically rely on hypergolic propellants or auxiliary electrical hardware to supply the energy required to initiate combustion. The resonance igniter is a simple and robust alternative to these conventional methods, capable of inducing autoignition of non-hypergolic propellants without an external ignition source. At the core of this concept is the Hartmann-Sprenger Tube (HST), a device in which a high-velocity jet of gas impinges on a resonance cavity. This interaction establishes self-sustaining gas oscillations within the cavity that heat the propellants to their autoignition temperature. To facilitate the development of a functional resonance igniter at …


Physics-Based Machine Learning Framework For Predicting Structure-Property Relationships In Ded-Fabricated Low-Alloy Steels †, Atiqur Rahman, Md Hazrat Ali, Asad Waqar Malik, Muhammad Arif Mahmood, Frank Liou Sep 2025

Physics-Based Machine Learning Framework For Predicting Structure-Property Relationships In Ded-Fabricated Low-Alloy Steels †, Atiqur Rahman, Md Hazrat Ali, Asad Waqar Malik, Muhammad Arif Mahmood, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Directed Energy Deposition (DED) process has demonstrated high efficiency in manufacturing steel parts with complex geometries and superior capabilities. Understanding the complex interplays of alloy compositions, cooling rates, grain sizes, thermal histories, and mechanical properties remains a significant challenge during DED processing. Interpretable and data-driven modeling has proven effective in tackling this challenge, as machine learning (ML) algorithms continue to advance in capturing complex property structural relationships. However, accurately predicting the prime mechanical properties, including ultimate tensile strength (UTS), yield strength (YS), and hardness value (HV), remains a challenging task due to the complex and non-linear relationships among process …


Wind Turbine Rotor Design Using High-Fidelity Aerostructural Optimization, Marco Mangano, Sicheng He, Yingqian Liao, Denis-Gabriel Caprace, Andrew Ning, Joaquim R. R. A. Martins Sep 2025

Wind Turbine Rotor Design Using High-Fidelity Aerostructural Optimization, Marco Mangano, Sicheng He, Yingqian Liao, Denis-Gabriel Caprace, Andrew Ning, Joaquim R. R. A. Martins

Faculty Publications

Large wind turbines yield more energy but demand careful aeroelastic blade design. Coupled multiphysics design strategies can reduce wind energy costs exploiting fluid-structure interactions. This work presents the first high-fidelity aerostructural optimization study of a large wind turbine rotor.We use blade-resolved fluid dynamics and structural solvers in a monolithic gradient-based optimization framework to explore steady-state torque and blade mass trade-offs. The coupled-adjoint approach computes gradients efficiently, enabling the optimization of over 100 structural and geometric parameters simultaneously. Our optimization study modifies a DTU 10 MW benchmark with a simplified structure and isotropic material properties. The tightly coupled optimizations increase torque …


Optimizing Hip And Knee Assistance For Walking And Sit-To-Stand Transitions: An Intrinsic Muscle Mechanics Based Predictive Approach, Neethan Ratnakumar Aug 2025

Optimizing Hip And Knee Assistance For Walking And Sit-To-Stand Transitions: An Intrinsic Muscle Mechanics Based Predictive Approach, Neethan Ratnakumar

Dissertations

As the global population ages, the demand for wearable assistive technologies continues to rise, driven by their potential to enhance mobility and independence in older adults. Effectively designed controllers for lower-limb exoskeletons to assist sit-to-stand (STS) and walking are crucial for delivering efficient, safe, and comfortable assistance during daily activities. Traditionally, controller optimization involves biomechanical modeling and user-specific customization. Musculoskeletal simulations play a central role in this process by providing insights into human-exoskeleton interaction dynamics, thereby informing and refining control strategies.

This work presents a simulation-driven approach for developing exoskeleton controllers for walking and STS using two distinct methods: optimal …