Engineering Commons^™

Porous Triboelectric Nanogenerator For Load Sensing Of Total Knee Replacement, Elham Mahmoudi, Adam Garry Redgrift, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This study addresses the critical need for self-powered, durable pressure sensors in Total Knee Replacement (TKR) implants to enable the collection of post-operative information. The scope of this research encompasses the design, development, and testing of a triboelectric nanogenerator (TENG) integrated into an instrumented knee implant for energy harvesting and pressure sensing. The authors’ unique approach involves utilizing a porous silicone rubber as a dielectric material. This allows the TENG to withstand forces up to 2000 N and generate a maximum power output of 18 μW. Theoretical modeling combined with experimental validation provides deeper insight into the fundamental operating principles. …

Robust Data-Driven Predictive Control Of Nonlinear Systems Under Modeling Uncertainty, Pegah Ghafghanbari

All Dissertations

Data-driven predictive control enables designing controllers directly from data, making it attractive for complex systems with hard-to-model dynamics. However, practical deployment is challenged by modeling inaccuracies and changing operating conditions. This dissertation develops predictive control frameworks that incorporate robustness and adaptability to address these issues in uncertain nonlinear systems.

The first part employs the Linear Parameter-Varying (LPV) framework, which represents nonlinear dynamics through simple linear form representation. To characterize the plant-model-mismatch often caused by limited data and numerical calculations, Bayesian Neural Networks (BNNs) are used, and their uncertainty estimates are integrated into two robust control approaches. The first is a …

Hydrodynamics Of Perforated Heave Plates, Muhammad Usman

All Dissertations

Ocean waves are a clean and renewable energy source that can help reduce dependence on fossil fuels and combat climate change. To capture this energy, researchers have developed devices known as wave energy converters (WECs). One common type, called a two-body point absorber WEC, uses a buoy floating on the ocean surface connected to a submerged reaction plate, known as the heave plate, which lies underwater. The relative up-and-down motion between the buoy and the heave plate, driven by ocean waves, generates usable power via a power take-off (PTO) system. Traditionally, these submerged heave plates are solid structures. However, this …

Opposed-Piston Two Stroke Engine As A High Power Density Solution In Heavy Duty Applications: An Experimental Evaluation With Diesel And Ethanol, Ankur Bhatt

All Dissertations

With an increasing demand to reduce greenhouse gas (GHG) emissions, the conventional powertrain technology is at a saturation point. There is reinvigorated research interest in alternative powertrain designs that offer potentially higher efficiencies and lower engine-out emissions compared to conventional powertrains. The opposed piston two-stroke (OP2S) engine is one such alternative engine architecture that has demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Like any two-stroke engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Without dedicated …

When Textures Trim Drag: Micro-Structures For Adaptive Drag Reduction And Flow Authority, Miguel Angel Olvera

Theses and Dissertations

Turbulent boundary layers are a major source of drag and performance loss. This thesis investigates Triangular Porous Texturing (TPT), apex-forward microstructures with optional bleed channels, as a passive concept for simultaneously reducing skin friction and strengthening boundary layer momentum near separation. Low-speed wind tunnel tests are conducted over tripped turbulent boundary layers on flat plates with three surfaces: a smooth baseline, a solid-crest TPT array isolating the knife-edge “slip-cut” effect, and a porous-bleed TPT array whose paired micro-channels vent a small fraction of the free stream. Time-resolved PIV provides wall-normal velocity fields; skin friction is inferred from near-wall shear, and …

Wearable Triboelectric Nanogenerators Based Sensors For Human Cardiovascular Monitoring: Progress And Perspectives, Mashrufa Akther, Andrea K. Quezada, Md. Arafat Hossain, Julia I. Salas, Md. Mahmud Alam, Mohammed Jasim Uddin

Mechanical Engineering Faculty Publications

Cardiovascular conditions remain the leading cause of death worldwide, driving a critical need for non-invasive, continuous, and dependable health monitoring results. Triboelectric nanogenerators have emerged as a groundbreaking technology enabling self-powered wearable sensors that convert natural biomechanical energy, such as heartbeat, pulse wave, and body motion, into electrical signals. The paper reviews the recent progress and development in TENG-based wearable sensors for cardiovascular monitoring, with a focus on monitoring particular and clinical healthcare. The working principles, advanced materials, structural designs, and integration with wireless data transmission, machine literacy, and bio-signal processing technologies are explored in this article. Operations, including heart …

Performance Assessment Of Reconditioned Freight Rail Bearings Using Eddy Current Array For Enhanced Nondestructive Inspection, Eduardo Miranda

Theses and Dissertations

In North America, freight bearings removed from service must undergo a reconditioning process in accordance with Association of American Railroads recommended guidelines before reuse, with approximately 80% having been reconditioned at least once. This process includes bearing inspection, where repairable defects may be refurbished and returned to service with an extended performance range of 50,000 to 250,000 miles. Motivated by this extensive range in performance, researchers at the University Transportation Center for Railway Safety, in collaboration with MxV Rail, utilized a nondestructive evaluation method to enhance the reconditioning inspection process. An Eddy Current Array (ECA) was applied to bearing cup …

Thermal Management With Supercritical Carbon Dioxide Under Extreme Applications, Devon Hardy

Doctoral Dissertations and Master's Theses

A unique challenge in thermal system design is minimizing the power required to operate cooling systems while maintaining effective heat removal. Traditional cooling systems utilize single-phase fluids where the heat transfer mechanisms are well understood. To meet a variety of cooling demands, a range of technologies are available, including microchannel forced convection, jet impingement, porous media, nanofluids, pin fin arrays, and film cooling, each offering distinct advantages and limitations. While the performance of single- or two-phase cooling systems are generally predictable, in extreme thermal environments, new cooling solutions are needed to improve overall system efficiency and reliability.

Supercritical fluids, particularly …

Further Evaluation Of Speed Tables On Roadway Curves: Simulation And Expeditionary Deployments, Nathan Reineke

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The road network leading up to a United States military base is known as an Entry Control Facility, or ECF. Entry control facilities are used to shield military installations by monitoring vehicles and refusing access to unauthorized vehicles. Passive control devices, including speed tables, are used to disrupt or delay threat vehicles attempting to navigate ECFs at high speeds. The purpose of this research was to recommend optimized configurations of speed tables in combination with roadway curves which allow safe, efficient traversal for authorized vehicles and disruption or delay for threat vehicles.

First, an analytical model of a Tesla Model …

Effect Of Capillary And Viscous Forces On Carbon Dioxide Desorption In Porous Adsorbent Layers, Caroline Isabel Mcclung

Theses and Dissertations

Temperature swing adsorption-based (TSA) carbon dioxide (CO₂) separation processes, which involve an alternating flow of gases and liquids in adsorbent-coated microchannels, have been shown to yield superior and environmentally friendly performance than the existing processes. This technique begins by sending the impure gas mixture through hydrophobic silicalite adsorbent-coated microchannels, which results in the adsorption of CO₂. Subsequently, hot water heat transfer fluid (HTF) flows through the same channels, displaces the purified gas stream, heats the adsorbent, desorbs the CO₂, and removes that desorbed CO₂ from the channel. This stage is followed by cooling …

Component Model Development Of Heat Exchangers, Expanders, And Control Valves For Autonomous Cryogenics Plant Cool-Down, William Harris Buhrig Iv

Mechanical & Aerospace Engineering Theses & Dissertations

The traditional method of cryogenic plant cool-down involves having continuous on-call staff to head into the office at any time to modify the existing multi-layered PID control systems if the on-call staff member detects a significant deviation from the cool-down plan. This thesis aims to outline an effective method for modeling the structure of systems with performance characteristics that deviate from design requirements and from ideal inlet-outlet correspondence, enabling the adjustment and modification of existing control structures across all Thomas Jefferson National Accelerator Facility (JLab) cryogenic refrigeration plants. Analytical Modeling and Gaussian Process Regression (GPR) are applied to model the …

Dynamic Modeling And Simulation Of A Power Generation Steam Rankine Cycle For A Fluoride Salt-Cooled High-Temperature Reactor Nuclear Power Plant, William R. Ton

Master's Theses

Nuclear Fluoride Salt-Cooled High-Temperature Reactors (FHRs) have the potential to greatly improve nuclear technology in terms of safety and cost. By combining molten salt coolant technology from the Molten Salt Reactor (MSR) and TRISO fuel technology from the Very High Temperature Gas Reactor (VHTR), FHRs may operate at significantly lower pressures than Light Water Reactors (LWRs) and with a more robust fuel source that is excellent at containing fission products. However, as no FHR has been built, there are still many design questions to address. This thesis uses transient computer modeling and simulation to investigate how an FHR could potentially …

Real Time Markerless 3d Hand Tracking For Intuitive Robotic Arm Control, Dylan G. Featherson

Master's Theses

This thesis presents a real-time, markerless motion-capture system for intuitive control of a multi-degree-of-freedom robotic arm. Using two synchronized RGB cameras and stereo-vision triangulation, the system reconstructs the three-dimensional position of a user’s hand without the need for physical markers or wearable sensors. The reconstructed 3D coordinates are mapped directly to the end-effector position of the Quanser QArm, a four-degree-of-freedom educational manipulator. Developed entirely in Python, the system integrates stereo camera calibration, 3D hand tracking with MediaPipe, coordinate transformation, and inverse kinematics into a unified real-time control pipeline operating at approximately 200 Hz. Calibration is performed through a checkerboard-based stereo …

Origami-Inspired Pneumatic Soft Robotic Gripper, Conor J. Schott

Master's Theses

This thesis presents the design and evaluation of a vacuum-actuated, origami-based soft robotic gripper. A custom Sea Urchin crease pattern forms a lightweight folding skeleton that collapses radially under vacuum. The system emphasizes low cost and accessibility through laser cutting, 3D printing, and silicone molding. The Sea Urchin geometry was selected after digital and physical screening of candidate crease patterns for smooth folding, low strain concentration, and uniform inward motion. The folding skeleton is laser cut from 4 mil drafting film and folded into a compliant core. Four membrane configurations were developed: an origami gripper with a 36-inch balloon (Design …

Investigation Of Laser Based Flow Diagnostics With Metastable Argon, Sterling S. Gordon

Physics Theses & Dissertations

The overarching motivation of this work is the development of seedless, non-intrusive, laser-based diagnostics for supersonic airflow in wind tunnels. To advance this goal, this dissertation fo-cuses on three-photon excitation in a research-grade argon beam within a tabletop vacuum system, which offers a controlled environment for testing and refining the approach. The chosen excitation scheme drives argon atoms to the 3d[5/2]₃ state using a pulsed Ti:Sapphire laser system, enabling time-of-flight (ToF) measurements on atoms that subsequently undergo a multi-step decay to the metastable 4s[3/2]₂ state. Although full realization of this excitation scheme was hindered by technical …

Harnessing The Mechanical And Gelation Behavior Of Tyramine-Substituted Silk Fibroin Bioinks Through Integration Into A Modular And Low-Cost 3d Bioprinting Platform, Sourjjadeepta Biswas

Boise State University Theses and Dissertations

3D printing has become an indispensable tool in research labs across the globe. Yet, when it comes to bioprinting with custom or sensitive bioinks, accessible options remain limited. Commercial systems are often prohibitively expensive and restricted to proprietary materials, while DIY setups frequently lack the precision and compatibility needed for biologically relevant printing. Moreover, tunable bioinks that align with real-world biological constraints are still hard to come by. To address these gaps, we developed a modular, low-cost bioprinting platform tailored for tyramine-substituted silk fibroin (TA-SF) hydrogels-biocompatible materials known for their rapid gelation, tunable stiffness, and potential to support cell differentiation …

Jhtdb-Wind: A Web-Accessible Large-Eddy Simulation Database Of A Wind Farm With Virtual Sensor Querying, Xiaowei Zhu, Shuolin Xiao, Ghanesh Narasimhan, Luia A. Martinez-Tossas, Michael Schnaubelt, Gerard Lemson, Hanxun Yao, Alexander S. Szalay, Dennice F. Gayme, Charles Meneveau

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper introduces JHTDB-wind (https://turbulence.idies.jhu.edu/datasets/windfarms), a publicly accessible database containing large-eddy simulation (LES) data from wind farms. Building on the framework of the Johns Hopkins Turbulence Database (JHTDB), which hosts direct numerical and some large-eddy simulation datasets of canonical turbulent flows, JHTDB-wind stores the full space-time (4D) history of the flow and provides users the ability to access and query the data via a web-based virtual sensor interface. The initial dataset comprises LES results from a large wind farm with 6 X 10 turbines, modeled using a filtered actuator line method, under conventionally neutral atmospheric conditions. This data comprises one …

Full Factorial Design Of Carbon Content And Heating Temperature On Height Reduction In Bonnell Springs, Yurida Ekawati, Cendana Anggun Sasmitha, Mochamad Syamsul Ma’Arif

Journal of Mechanical Engineering Science and Technology (JMEST)

The durability of Bonnell springs, which are widely used in the manufacture of spring beds, is often compromised by height reduction during use, which negatively impacts product comfort and quality. This study aims to minimize spring height reduction by investigating the effects of heating temperature and carbon content in the spring steel. A full factorial experimental design was applied using two factors: heating temperature (250°C, 260°C, and 270°C) and carbon content (0.72%, 0.73%, and 0.74%). Nine treatment combinations were tested, with five replicates each, and the height reduction values were measured after 100 compression cycles. The data were analyzed using …

Simulation Of Stress, Deformation, And Vibration In Unlubricated Ball Bearings At Varying Rotational Speeds, Billy Dwiki, Moh. Hartono

Journal of Mechanical Engineering Science and Technology (JMEST)

Bearings are critical components in rotating machinery, and their performance is highly influenced by operational factors such as rotational speed, load, and lubrication. This study aims to analyze the deformation, stress, and dynamic behavior of SAE 52100 bearings under dry operating conditions at various rotational speeds, as well as to propose mitigation strategies for high-speed industrial applications. A finite element simulation was conducted using ANSYS R19.2 to evaluate the total deformation, equivalent elastic strain, Von Mises stress, and vibrational characteristics of a 6204-type SAE 52100 bearing. The simulations were performed across a speed range of 600 to 2000 RPM under …

Optimizing Zeolite Catalysts For Efficient Ldpe Plastic Waste Pyrolysis, Hilda Porawati, Mazwan Mazwan, Sukadi Sukadi

Journal of Mechanical Engineering Science and Technology (JMEST)

The problem of plastic waste, particularly from low-density polyethylene (LDPE) plastic bags, poses a significant challenge in environmental management due to its non-biodegradable nature and widespread use in daily life. This study evaluates the influence of catalyst types on the characteristics and energy efficiency of liquid fuel products produced from LDPE waste pyrolysis. The three treatments compared were no catalysts, natural zeolite catalyst, and synthetic zeolite catalysts, each subjected to three different temperature variations: 250°C, 300°C, and 350°C. The observed parameters in this study were volume, product mass, cetane index, density, sulfur content, viscosity, flash point, calorific value, and energy …

Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif

Journal of Mechanical Engineering Science and Technology (JMEST)

Vegetable oil-based cutting fluids are of great importance in supporting green and sustainable manufacturing. This research introduces a new groundbreaking vegetable lubricant formulated with canola oil as the base material, coupled with CaCO3 nanoparticles synthesized from scallop shell waste and used as a cutting fluid in the AISI 1045 CNC machining process steel sprayed with minimum quantity lubrication (MQL). This investigation delves into the thermophysical, rheological, and wear resistance of the developed bio-lubricant. The results of this analysis show density value increased in the canola + CaCO3 0.15% sample by 3.28% of the pure canola sample, as did the viscosity …

Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to evaluate the influence of adding copper aluminum–alumina composite (Al–Al₂O₃) against characteristic thermal properties through metallurgical powder. Three variations of the composition of weight copper were used, namely 5%, 10%, and 15%, with aluminum as the matrix and alumina as the reinforcement. Thermal test covering analysis of thermal conductivity, specific heat, and microstructure characterization using SEM-EDX. The results show that adding Cu increases thermal conductivity significantly, with the highest mark achieved in the 15% Cu composite (6.47 W/m.°C). However, the increase in Cu content above 10% causes the agglomeration of particles and enhancements in porosity, which harms …

Numerical Investigation Of Ethanol-Enriched Diesel And Biodiesel Fuels In A Diesel Engine, Annisa Bhikuning, Hezron Elyakim Potto, Sandi Apriandi Setiawan, Jamal F. Jati

Journal of Mechanical Engineering Science and Technology (JMEST)

This study explores the effects of ethanol blending on the performance and emissions of a compression ignition (CI) engine using both diesel and biodiesel as base fuels. Motivated by increasing environmental concerns regarding pollutant emissions from conventional diesel engines, ethanol was introduced as an oxygenated additive to improve combustion characteristics and reduce the formation of harmful exhaust emissions. Ethanol’s high oxygen content promotes more complete combustion, potentially lowering carbon-based emissions such as carbon monoxide (CO), particulate matter (PM), and unburned hydrocarbons. In this study, performance and emission parameters were simulated using Diesel-RK software at various engine speeds of 1500, 2000, …

One-Way Thermal-Fluid-Solid Coupling Analysis Of Helicopter Tail Reducer With Spiral Bevel Gear, Dongping Sheng, Zhongyuan Ma, Chenqi Zhou, Haidong Feng, Hun Guo, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

This research focuses on investigating the thermal-fluid-solid coupling behavior within spiral bevel gears to enhance the bearing capacity and extend the operational service life of the gear reducer located in the helicopter tail gearbox. The study commences by constructing detailed, parametrically defined threedimensional digital models. These models accurately represent the critical components: the spiral bevel gear itself, the surrounding gearbox housing, and the supporting gear shaft, based directly on the specifications of an actual helicopter tail reducer assembly. Subsequently, the analysis proceeds with a one-way, steadystate thermal-solid coupling simulation performed on the established model assembly. This critical simulation phase aims …

The Impact Of Pine Resin-Epoxy Ratios On Fire Resistance And Acoustic Performance Of Banana Fiber Composites, Cokorda Istri Putri Kusuma Kencanawati, Dewa Ngakan Ketut Putra Negara, I Gede Andy Andika Parahita

Journal of Mechanical Engineering Science and Technology (JMEST)

Because of their low environmental impact and biodegradability, composite materials derived from natural fibers and resins have drawn interest as sustainable substitutes for synthetic materials in thermal and acoustic applications. Two promising natural components are banana stem fiber and pine resin, but they need to be modified due to their mechanical limitations and flammability. Epoxy resin is commonly used to enhance structural performance; however, its effects on acoustic and fire resistance properties require further investigation. This study examined how different epoxy resin contents affected the sound absorption and fire resistance of composites made from banana stem fiber and pine resin. …

Effect Of Argon Gas Flow Rate On Crystal Structure, Morphology, And Optical Properties Of Cigs Film For Photodetector Applications, Nurul Lathi’I Fatul Chamidah, Fadilah Wulan Cahyani, I Gusti Ayu Isnaini Fatha Ramadhani, Erma Surya Yuliana, Nasikhudin Nasikhudin, Safwan Abd. Aziz, Nandang Mufti

Journal of Mechanical Engineering Science and Technology (JMEST)

CIGS material can be used as a material for photodetector applications. The deposition of CIGS thin films remains challenging. Generally, argon is used as a gas to bombard the CIGS material through the sputtering method. This study fabricated photodetectors by varying the argon gas flow rate (50-80 sccm) to investigate its effect on device performance. XRD, SEM, UV-Vis, and photoresponse tests were characterized. Structural analysis using XRD showed a weak (112) diffraction peak, indicating that the resulting film was not fully crystalline, but rather consisted of a nanocrystalline phase, even partly amorphous, with small crystallite sizes. According to the SEM …

Spray Angle On The Performance Of Split-Type Ac Condenser Installed On Concrete Rooftop In Tropical Climate, Kennedy Kennedy, I N Frenki Aryana, Basri Basri

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigated the influence of different water spray angles (0°, 15°, and 30°) on the thermal and energy performance of a split-type air-conditioning (AC) condenser installed on a concrete rooftop in a tropical climate. An experimental setup was designed to replicate actual concrete rooftop conditions, focusing on the condenser inlet temperature, compressor power consumption, and system coefficient of performance (COP). A 6-minute ON and 6-minute OFF intermittent spray cycle was employed to optimise water usage and minimise excessive humidity. Experimental measurements were conducted on a 9,000 Btu/h split-type unit equipped with a nozzle system connected to a 200 L …

The Effect Of Preheater On Heat And Mass Transfer Efficiency Using Rotating Drum Roaster, Melisa Surya Andini, Retno Wulandari, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is the third-largest coffee producer globally, facing challenges including rising raw material costs, increased energy consumption, and unpredictable weather conditions. One potential solution is optimizing energy efficiency during roasting. This study investigates the effect of preheating on time and energy efficiency in heat and mass transfer by utilizing waste heat to preheat green Robusta coffee beans. The experiment was conducted on a laboratory scale using a rotating drum roaster with a double-layer drum made of stainless steel and clay, at 200 °C under atmospheric pressure. Two treatments were applied: roasting with a preheater and without, each repeated three times …

Impact Of Cpo And B35 On Diesel Engine Rocker Arm Wear During Long-Term Operation, Fawwaz Aqilah Nurmansyah, Nur Fadilah Rizky Supramono, Muhammad Ikhsan, Erwan Adi Saputro, Wiliandi Saputro

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing number of motor vehicles has led to higher fossil fuel consumption, contributing to greenhouse gas emissions, climate change, and environmental degradation. As a renewable alternative, biodiesel offers a way to reduce these impacts. Indonesia, with its abundant natural resources, has significant potential for biodiesel production. Crude palm oil (CPO) is a promising feedstock due to its availability and relatively low environmental impact. However, the high costs associated with the transesterification process make direct use of pre-heated CPO an area worth exploring. This study investigates the impact of pre-heated pure CPO compared to B35 ("Dexlite") on rocker arm wear …

Numerical Analysis Of The Effect Of Vortex Generator On The Aerodynamic Performance Of Naca 6412 Airfoils Using Large Eddy Simulation, Dedet Hermawan Setiabudi, Joan Bayuaji Nugroho, Eli Kumolosari, Lazuardy Rahendra Pinandhita, Okto Dinaryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Aerodynamic performance of an airfoil is significantly affected by flow separation, especially at high angles of attack. One common strategy to control flow separation is adding a triangular vortex generator (VG), which creates small vortices that help keep the airflow attached. The present study investigated the impact of triangular vortex generators on a NACA 6412 airfoil using Computational Fluid Dynamics (CFD) method. Large Eddy Simulation (LES) was applied due to its ability to show the vortices more clearly than other methods. It can also accurately capture the flow separation. To obtain the lift, drag, and lift-to-drag ratio (CL/CD) data, four …