Mechanical Engineering Commons^™

Investigating The Impacts Of Information Framing And Representation On Multi-Stakeholder Decision-Making For Tradespace Exploration, Meredith G. Sutton

All Dissertations

Tradespace exploration (TSE) is a decision-making process used in engineering design to search through a tradespace, containing all potential solutions to a design problem and their performance evaluations, in order to select optimal or near-optimal solutions. Solution optimality is driven by a desire to maximize the overall utility of a solution, which often cannot be done without making tradeoffs or compromises. The TSE process requires vast amounts of information which can be difficult to generate and understand, often leading to challenges including information overload, delays in decision-making, and suboptimal decisions, even for the most experienced designers. To address the challenges …

Thermal Degradation Analysis Of Bagasse Fibers From Sugarcane Waste, Rashmitha Suresh, Faisal Al Nasser

Journal of Mechanical Engineering Science and Technology (JMEST)

Sugarcane is one of the important commodities in the industry where bagasse fiber as waste is abundantly available.   Sugarcane bagasse fiber has high cellulose, a key element in the utilization of bagasse. Chemical pretreatment is important to prepare the natural fiber before used as composite reinforcement. The purpose of the study is to analyze the thermal degradation of bagasse fiber after being treated using NaOH and TEMPO solution. The manufacturing method was carried out by a series of washing bagasse with distilled water and NaOH solution, subsequently soaking it in 6% NaOH and 2,2,6,6-tetramethylpiperidine-l-oxyl (TEMPO) solution, and conducted oven-dried. Thermogravimetric …

Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer

Faculty Publications and Presentations

The Cosmic Fabric Model establishes a continuum-mechanics isomorphism to General Relativity by representing physical space as an elastic three-dimensional hyperplate embedded in a four-dimensional spatial bulk. Reproducing vacuum kinematics requires a vanishing P-wave modulus, which in turn implies a negative bulk modulus—an apparent thermodynamic instability in a closed system. This paradox is resolved by recasting the framework as an open system: the instability is not pathological but instead drives cosmic expansion. In this interpretation, the observable universe is a lower-energy solid formed through continuous solidification from a higher-dimensional precursor fluid. Using multiplicative kinematics from finite-growth mechanics, the model shows that …

Developing Simulation To Improve G3p3 Efficiencies, Andrew Gaudette

Mechanical Engineering ETDs

Concentrated solar power (CSP) systems offer a promising method of renewable energy generation by using heliostats to focus sunlight onto a falling particle receiver. At the National Solar Thermal Testing Facility (NSTTF), particles absorb and store solar energy for later power generation. A major source of efficiency loss is wind-driven particle escape through the receiver aperture. This thesis develops computational fluid dynamics (CFD) simulations to characterize wind flow around the G3P3 falling particle receiver and support future wind mitigation strategies. Numerical studies were conducted to establish an appropriate simulation methodology. Iteration studies showed that 2,000 iterations were sufficient for convergence, …

Control Of Reshock In A Shock Tube, Alexander Sweis

Mechanical Engineering ETDs

Reshocks can pose a threat to the structural integrity of structures and buildings. While incident shock waves pose larger threats, the study of reshocks and reshock attenuation is important to consider. This thesis investigates methods for controlling and attenuating reshock strength within a shock tube through material-based damping and modifications to baffle box geometric configurations. Experiments are performed using a custom-built shock tube in the University of New Mexico fluid mechanics laboratory. Four baffle box configurations are examined: a foam-lined configuration, a foam-lined configuration with ”egg crate-like” textured foam, an empty (no foam) configuration, and a configuration which incorporates a …

Development Of Dynamic Proof-Mass Configurations For Broadband Piezoelectric Energy Harvesting, Nico E. Galarza

Electrical and Computer Engineering ETDs

The purpose of this thesis is to investigate and develop dynamic proof-mass configurations for broadband piezoelectric energy harvesting. Conventional piezoelectric energy harvesters are typically limited by narrow operating bandwidths, restricting their performance under variable-frequency excitation. This research presents the design, fabrication, and experimental evaluation of multiple proof-mass concepts intended to increase the usable frequency range of cantilever-based piezoelectric energy harvesters. Several dynamic mass configurations were developed using additive manufacturing techniques and integrated with commercially available piezoelectric cantilevers. Experimental testing was conducted under controlled vibration conditions to characterize voltage response, resonant behavior, and bandwidth performance. The results demonstrate that dynamic proof-masses …

Investigating Light-Matter Interactions In Low-Dimensional Silicon Carbide, Nishan Shrestha

Mechanical Engineering ETDs

Recent advances in materials science have transformed the study and application of low-dimensional materials, with two-dimensional (2D) systems and nanoscale structures exhibiting properties beyond their bulk counterparts. Despite significant progress in materials such as graphene and silicon, the nanoscale exploration of silicon carbide (SiC) remains relatively underdeveloped, despite its critical importance in photonics and electronics and high temperature applications. Motivated by the transformative potential of nanoscale material design and the technological importance of SiC, this dissertation investigates structure and properties of low-dimensional silicon carbide structures. It explores the synthesis and optical properties of SiC nanosheets and nanowires using a variety …

Analysis Of Electronic Control Unit Optimization On The Performance Of A 150 Cc Motorcycle Engine Using Ethanol-Blended Fuel, Agus Achmad Syaiful, Annisa Bhikuning, Muhammad Rizal Baihaqi, Muhammad Aulia Rafli

Journal of Mechanical Engineering Science and Technology (JMEST)

The use of ethanol-blended fuel in a standard vehicle can reduce combustion quality, which has an impact on decreasing vehicle performance. At the above 20% blend level, it affects vehicle performance and requires adjustments to engine settings or the Electronic Control Unit (ECU) before use on conventional engines. This study investigates the effect of aftermarket ECU settings on the performance of a 150 cc motorcycle operating on a gasoline-ethanol blend. Four fuel variations were tested: Pertalite (P100), revvo 90 (R100), and 30% ethanol blends (PE30 and RE30). This study analyzes the effects of optimizing injection duration and ignition timing settings …

Object Avoidance Onboard An Autonomous Underwater Vehicle In Support Of Geomagnetic Based Navigation System, Eric Benavidez

Electronic Theses and Dissertations

The objective of this thesis was to collect and analyze magnetic field data in the vicinity of the Mercy, Tracey, and Jay Scutti with an autonomous underwater vehicle (AUV) and a forward mounted magnetometer. The collected data was used to develop geomagnetic contour maps and magnetic thresholds of known anomalies to compare the results with validated sources such as NOAA.

In addition, this collected data was used to develop a Gazebo simulation which accurately modeled the magnetic field data and ocean effects of the Fort Lauderdale Shipwreck Trail. This Gazebo simulation allowed for proper testing and refinement of object avoidance …

Chemical Composition Stability Of Cu–Sn And Cu–Zn Journal Bechemical Composition Stability Of Cu–Sn And Cu–Zn Alloys Fabricated By Sand And Permanent Mold Casting With Nickel Alloying, Erwin Erwin, Didik Sugiyanto, Juan Pratama, Trisna Ardi Wiradinata, Abdul Rachmadhan, Muhammad Fikri Andika

Journal of Mechanical Engineering Science and Technology (JMEST)

The processes of moulding and reinforcing chemical elements have a big impact on the balance of chemical composition in copper-based bearing alloys. This has a direct impact on how well the material works. This study examines Cu–Sn alloys produced via sand casting and Cu–Zn alloys fabricated through permanent mould casting, with the incorporation of nickel, which remains uncommon. The objective was to examine the variations in the equilibrium of the chemical composition and the performance potential of the bearing alloy metal when subjected to different casting techniques and nickel concentrations ranging from 0% to 4%. Some of the methods used …

Effect Of Concentration And Temperature Of Tio2-Al2o3 Hybrid Nanofluid On The Corrosion Rate Of Aluminum Radiator, Ratna Monasari, Rizky Maulana Ramadhan, Nike Nur Farida, Ahmad Hanif Firdaus, Supa Kusuma Aji, Yuniarto Agus Winoko, Rizkyansyah Alif Hidayatullah

Journal of Mechanical Engineering Science and Technology (JMEST)

Corrosion of aluminum radiators can reduce cooling system reliability and shorten service life in automotive applications. This study examines the effect of TiO₂-Al₂O₃ hybrid nanofluid concentration and temperature on the corrosion rate of commercially available aluminum radiator material. Hybrid nanoparticles with a TiO₂-Al₂O₃ mass ratio of 50:50 were dispersed in distilled water at concentrations of 0.6 wt.%, 0.8 wt.%, and 1.0 wt.%. Corrosion behavior was evaluated using a 14-day accelerated immersion test at 60°C and 80°C, and the corrosion rate was determined using the gravimetric mass loss method. The results …

Experimental Evaluation Of Membranes In The Recovery Of Hydrogen From Serpentinization, Rafael Dos Santos

LSU Master's Theses

Natural hydrogen generated through serpentinization reactions has emerged as a promising low-carbon energy resource. However, serpentinization-derived gas streams commonly contain methane (CH₄) and carbon dioxide (CO₂), requiring purification before hydrogen can be utilized in industrial applications. Membrane-based gas separation technologies offer a potentially cost-effective solution for hydrogen recovery; however, to the best of the author's knowledge, no previous studies have specifically investigated their application to serpentinization-derived gas streams.

This work evaluates the performance of two commercial polymeric membrane modules (Evonik and Generon) and one palladium-copper (Pd-Cu) membrane module (Okaya) for hydrogen recovery from gas compositions representative of serpentinization environments. An …

Global Time-Resolved Measurements Of Inlet/Isolator Unstart Induced By Mass Injection, Andrew N. Bustard, Benjamin L. Bemis, Aaron Marques, Matthew J. Zahr, Thomas J. Juliano

Publications

The inner surface pressure of an axisymmetric inlet/isolator model was measured using anodized-aluminum pressure-sensitive paint (PSP) viewing through cast acrylic. Temperaturesensitive paint was utilized to correct for the PSP’s temperature sensitivity. The model was tested under Mach 5.7 flow at 𝑹𝒆 = 7.1 ×106 /m under conventional noise conditions. Transverse jet injection with jet-to-inlet mass-flow ratios up to 0.8 was used to induce unstart in the inlet/isolator. Background-oriented schlieren visualization of the inlet shocks was collected simultaneously with the PSP to determine when the inlet unstarted. Computational fluid dynamics results were used to determine off-wall flow structures and quantify approach …

Straw As A Potential Vegetable Fibre Insulative Infill In Framed Constructions - Material Testing\Tnotereftnote1, Patrick Daly

Journal of Sustainable Construction Materials and Technologies

The construction sector faces increasing pressure to reduce embodied carbon and adopt circular material strategies, with bio-based materials offering a promising pathway. Straw-based insulation, particularly in loose-fill form, has gained traction in Europe, where several products have achieved certification under EAD 040138-01-1201. This study investigates the potential of Irish-processed straw chip as a bio-based insulative infill for framed construction by evaluating its material properties and thermal conductivity–density performance relative to European ETA-certified reference products. A programme of laboratory testing was undertaken on commercially available Irish straw samples, including material characterisation (moisture content, particle morphology, and dust content) and thermal conductivity …

Development And Characterization Of Mycelium-Based Biocomposites From Ganoderma Lucidum Using Spent Yerba Mate And Residual Sunflower Oil For Sustainable Insulation In Construction, Paula V. Alfieri, Guadalupe Canosa

Journal of Sustainable Construction Materials and Technologies

The construction industry urgently requires sustainable alternatives to petroleum-based insulation materials such as expanded polystyrene (EPS) and mineral wool. Mycelium-based biocomposites offer a promising solution by valorizing agricultural waste while delivering competitive thermal and acoustic performance. In this study, developed and characterized biocomposites using Ganoderma lucidum mycelium combined with spent yerba mate and residual sunflower oil (70 g/30 mL), both commonly generated as waste in Argentine institutions. Two formulations were evaluated: high density (HD: 280 ± 5 kg/m³) and low density (LD: 185 ± 5 kg/m³). Samples were cultivated for 90 days at 28 °C and 65% relative humidity and …

Comparative Life Cycle Assessment Of Hemp Walls In Residential Construction In Morocco, Hicham Kaddouri, Rachida Elbarghmi, Firyal Latrache, Marwane Hammouti, Abderrahim Abidouche, Ismael Driouch

Journal of Sustainable Construction Materials and Technologies

This study analyzes the energy and environmental performance of hemp-based wall solutions applied to Moroccan residential buildings by combining dynamic thermal simulation and life cycle assessment (LCA). A reference building is assessed under four representative Moroccan climates (Al Hoceima, Oujda, Marrakech, and Ouarzazate), comparing a conventional wall retrofitted with hemp plaster and a wall incorporating hemp concrete. The results show that hemp concrete significantly reduces annual heating and cooling energy demands by 20–24% depending on the climate, with heating needs decreasing by up to 40% and cooling needs by approximately 15%, particularly in hot and arid regions. The LCA reveals …

Dual-Waste Integration For Geotechnical Improvement: Silica Fume And Eggshell Ash In Kaolin Soil Stabilization, Ng Jun Shen, Muzamir Hasan, Siti Sarah Eliyun, Md. Ikramul Hoque, Mohamad Afiq Jazrin Mohamad Sidek

Journal of Sustainable Construction Materials and Technologies

This study reveals the potential substitution of silica fume and eggshell ash in the technique of soil stabilization, varying across distinct proportions in the modification of geotechnical parameters. The untreated kaolinitic soil which has low soil bearing capacity in nature is frequently reflected in its mechanical instability, for instance, soil settlement and extreme compressibility. By associating the industrial and agricultural material, it is potentially to resolve the above-mentioned issues with explicit designs. A number of laboratory approaches have been implemented in the assessment of basic geotechnical properties, including grain size distribution, Atterberg limits, specific gravity, proctor properties, and shear strength …

Innovation-Driven Development Of Advanced Manufacturing Industry Clusters: Trends, Issues, And Implications For 15th Five-Year Plan, Mu Rongping, Jingjing Guo, Yuchen Li, Qiang Li, Ze Feng, Mengyuan Zhu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Advanced manufacturing industry clusters have emerged as a key driver of global manufacturing transformation and upgrading, playing an increasingly significant role in technological innovation, industrial collaboration, supply chain resilience, and green, low-carbon development. This study systematically analyzes the innovation development trends of advanced manufacturing clusters worldwide, outlining the strategic layouts, policy measures, and implementation pathways adopted by major countries. Based on a comprehensive review of China’s current development status and prominent challenges in this field, the study proposes targeted policy orientations and recommendations. These policy recommendations include strengthening the innovation capacity of clusters, improving collaborative innovation networks, promoting the integration …

Structural Design And Finite Element Analysis Of A 54 Ton Freight Wagon Bolster Test Rig Under Vertical Center Plate Load, Shandy Dwi Prayoga, I Dewa Gede Ary Subagia, I Ketut Adi Atmika, Abdul Rohman Farid, Yunior Lanang Satrio

Journal of Mechanical Engineering Science and Technology (JMEST)

Bolster is one of the bogie's components that receives direct loading from the car body and freight movement. One of the problems that occurs in the bolster is permanent deflection during vertical and transversal static loading. Therefore, a static loading test is required to evaluate the structural strength of the bolster. During the static loading test, a rig is required to hold the bolster so that the bolster is in a fixed position. The rig owned by PT. INKA (Persero) showed a plastic deformation at the vertical center plate load (VCP 5.22P). Therefore, a modified design of the rig is …

Numerical Simulation Of Centrifugal Pump Performance Under Impeller Blade And Suction Diameter Variations, Gunawan Budi Santoso, Susanto -, Akhmad Nuriyanis, Anang Budhi Nugroho, Rizka Noor Miftakhul Ulum, Suyono -

Journal of Mechanical Engineering Science and Technology (JMEST)

The objective of this study is to model variations in pump geometry to obtain optimal performance under the effects of cavitation. The resulting geometric variation models were then simulated using ANSYS Fluent software. The first geometric variation model used a standard 5-blade impeller with suction pipe diameter variations of 2, 2 ½, 2 ¾, 3, 3 ¼, 3 ½, and 4 inches. The second geometric variation model for simulation used a standard 3-inch suction pipe with impeller blade variations of 3, 4, 5, 6, 7, 8, and 9. The simulation results indicated that the number of blades without changes in …

Characterization Of Various Corrosion-Resistant Rebars Embedded In Concrete After 20 Years Of Exposure, Samantha Mavrak

Electronic Theses and Dissertations

In aggressive marine environments, the deterioration of reinforced concrete structures is primarily caused by chloride-induced corrosion of embedded carbon steel reinforcement, resulting in concrete cracking, spalling, and costly maintenance or premature replacement. Corrosion-resistant reinforcement has been developed to mitigate these effects; however, long-term field performance data remain limited. This study evaluates the long-term corrosion performance of several corrosion-resistant rebars embedded in simulated deck slab concrete specimens following approximately 20 years of chloride exposure.

Concrete specimens containing 304SS, 316SS, and 2304 duplex SS, two types of clad reinforcement (316SS with carbon steel core), and an intermediate alloy with 12% Cr were …

Property Tables For Thermally Perfect Gases At Low Pressure, Travis J. Moore, Matthew R. Jones

Faculty Publications

Tables giving gas properties at low pressure enable the efficient analysis of processes in which the gas is approximated as thermally perfect but not calorically perfect. In addition to specific enthalpy and specific internal energy, thermally perfect gas tables include special functions that depend only on temperature—relative pressure and relative specific volume. These functions may be used to determine pressure, volume, and temperature of thermally perfect gases undergoing hypothetical isentropic processes. However, the definitions of these functions included in widely used thermodynamics textbooks are vague, inconsistent, or incorrect. The intent of this work is to discuss common inaccuracies in the …

Enhancement Of A Copolyester’S Impact Resistance Via Inorganic Reinforcement, David Felipe Gonzalez

Electronic Theses and Dissertations

Thermoplastic copolyester elastomers (TPEEs) are widely used in engineering applications because of their flexibility, toughness, and chemical resistance. However, prolonged exposure to marine environments can reduce their mechanical performance through moisture-induced degradation. This research investigated the use of titanium dioxide (TiO2) nanoparticles and APTES-functionalized TiO2 nanoparticles to improve the mechanical, thermal, and environmental durability of Hytrel 5556. Nanocomposites containing 1 wt.% and 2 wt.% TiO2 were fabricated through melt blending and compression molding. Mechanical properties were evaluated through tensile, compression, flexural, and impact testing, while thermal behavior was characterized using differential scanning calorimetry (DSC). Nanoparticle dispersion was examined using scanning …

A Reduced-Order Framework For Stochastic Criticality Estimation In Granular Energetic Materials, Philip T. Melton

LSU Master's Theses

Granular energetic materials (EMs) exhibit stochastic shock initiation because pore collapse, frictional dissipation, and localized thermal activation depend on microstructural descriptors that vary between nominally identical samples. Fully resolved mesoscale and atomistic calculations can represent these mechanisms, but their computational cost limits direct ensemble evaluation of microstructure-conditioned criticality thresholds. This thesis introduces a reduced-order framework for stochastic criticality estimation in granular EMs by coupling five explicitly defined model components: first, a one-dimensional steady compaction-shock model that maps initial solid volume fraction and shock pressure to a bulk mass-specific dissipated-work budget; second, an SEM/synthetic-image segmentation workflow that extracts pore area, perimeter, …

Analysis Of The Fracture Toughness Of Ercual A2 Cladding On Api X70 Using The Instrumented Charpy Impact Test, Martín Aguirre-Pulido, Francisco Fernando Curiel-López, Jose Jaime Taha-Tijerina, Jorge Alejandro Verduzco-Martínez, Víctor Hugo López-Morelos, Heriberto Granados-Becerra, Ariosto Medina-Flores

Mechanical Engineering Faculty Publications

The degradation of steel used in the oil industry has become a serious problem due to the high costs associated with material loss from corrosion. Applying thin layers of corrosion-resistant material promises to be a viable alternative for extending the service life of pipelines. ERCuAl-A2 electrode claddings were applied to API X70 carbon steel using the MIG brazing process with direct current (DC) and pulsed current (P). The cladding was applied under three conditions: base material (BM) at room temperature, BM preheated to 120 °C, and Ni-buttered BM. Microhardness profiles and Charpy impact tests were performed on the MB and …

Evaluation Of Optimal Force For Intrusion Of A Periodontally Compromised Maxillary Anterior Dentition Treated With Fixed Orthodontics – A Finite Element Analysis, Tanzim Ahmed, Amrita Puri, Aatira Nair, Anshul Singla, Mathew Koshy Vaidyan, Shruti Sharma, Chhavi Singh

International Arab Journal of Dentistry

Introduction: Adult orthodontic treatment is increasingly sought due to aesthetic and functional concerns, often involving periodontally compromised patients with altered biomechanics. Reduced bone support shifts the center of resistance and necessitates lower, carefully controlled forces, while finite element modeling has become a key tool to analyze tissue response under such conditions.

Objectives: The study aimed to determine the optimal intrusive force for periodontally compromised maxillary anterior teeth using Finite Element Analysis (FEA).

Methods: A 3D finite element model of the maxillary anterior dentition was created and divided into healthy and compromised halves, the latter with one-third alveolar bone loss. A …

Effect Of Naoh Concentration On The Structural, Morphological, And Tensile Properties Of Pineapple Stem Fibers, Ahmad Norca Kurnia Zen, Heru Suryanto, Aminnudin Aminnudin, Fajar Nusantara, Joseph Selvi Binoj

Journal of Mechanical Engineering Science and Technology (JMEST)

Natural fiber reinforced composites are increasingly being developed due to their environmentally friendly nature, low production costs, and safety for human health. However, the presence of lignin and hemicellulose reduces adhesion properties between fiber and composite matrix. Alkalization treatment is an effective way to remove lignin and hemicellulose attached to cellulose. This study aims to determine the optimum concentration of NaOH used during alkalization process of pineapple stem fiber. The methods included the retting process of fibers from pineapple stems. The obtained fibers were soaked in variations of 2%, 4%, 6%, and 8% NaOH for 4 hours,  then dried and …

Pseudodifferential Absorbing Boundary Conditions For Waves, Lauren Taylor

Mechanical Engineering Theses

Absorbing boundary conditions (ABCs) are required to truncate the computational domain when performing Finite Element Analyses of exterior acoustic problems where physical domain is unbounded. ABC is applied on a fictitious boundary containing the scatterer and ideally allows outgoing waves to leave without non-physical reflections. Preventing artificial reflections is essential to benefit from the accuracy of the numerical method used. Otherwise, ABC acts as a reflective surface, and artificial reflections distort the solution in the entire domain which is not recoverable by any type of refinement. Pseudodifferential ABCs were used to describe the Dirichlet-to-Neumann map which maps known boundary values …

3d Semi-Analytical Thermo-Elasto-Plastic Model For Additive Manufacturing, Tao Liu, Ming C. Leu, Edward C. Kinzel, Chinedum Okwudire

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In additive manufacturing (AM), stress field drives distortion and warping and promotes delamination and cracking. Fast, accurate stress prediction is therefore essential for AM process planning and control, including real-time adaptive control, AM digital twins, data-driven and physics-driven workflows. However, spot-wise thermo-elasto-plastic finite element method (FEM) are often too slow for design iteration or real time use. Existing semi-analytical thermo-elasto-plastic approaches achieve high speed but are largely limited to 2D. In this paper, a full 3D semi-analytical thermo-elasto-plastic model for AM is built. The method uses a spot-wise analytical thermal field as the load and computes displacements and stresses via …

Performance Evaluation And Sustainable Benefits Of Using Metakaolin And Recycled Steel Fibers In Concrete, Lova Raju Surla, Ramprasad Naik Desavathu, Raja Murugadoss Jeyaraju

Journal of Sustainable Construction Materials and Technologies

The rapid accumulation of waste vehicle tires and the increasing demand for cement pose significant environmental challenges through land pollution and CO2 emissions. The combined use of recycled steel fibers (RSFs) recovered from waste tires and supplementary cementitious materials (SCMs) offers a sustainable solution to these issues. This study investigates concrete incorporating 20% fly ash (FA), varying metakaolin (MK) contents (4–16%), and RSF dosages of 0.5–1.5%. Mechanical properties (compressive, split tensile, and flexural strengths) and durability characteristics (sorptivity, water absorption, chloride permeability, and homogeneity) were evaluated at 7, 28, and 90 days. Results showed that the mixture containing 20% FA …