Mechanical Engineering Commons^™

Neural Operator And Physics-Informed Deep Learning Approaches For Inverse Design Of Composites And Manufacturing Processes, Minglei Lu

All Dissertations

In this dissertation, artificial intelligence (AI) models are designed and used to accelerate inverse design of composites and manufacturing processes. The critical bottlenecks in machine learning (ML) including data availability, data quality, model generalization and adaptation, interpretability, physical consistency, and the ’black box’ nature of models for the inverse design are addressed. And the proposed AI models are tested under different engineering scenarios. Firstly, a fast deep neural operator (DNO) structure was developed to significantly reduce training time. This model was tested in the context of additive manufacturing, a transformative industrial technology that allows for the creation of materials with …

Investigation Of Conductive Die-Top Thermal Capacitors During Short Circuit Operation Of Silicon Carbide Devices, Youssef Abotaleb

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Silicon carbide (SiC) power devices have garnered significant attention in recent years due to their superior thermal and electrical properties compared to traditional silicon devices. However, SiC power devices suffer from severe reliability issues arising from their mechanical properties. This is because the Young's modulus of SiC is about three times larger than that of silicon, which correspondingly raises the mechanical stresses acting on the bonding structure, often leading to device failure under power shock events.

Traditional packaging materials and designs tend to constrain SiC performance, as hot-spot temperature resulting from a power shock is one of the key factors …

Multiphysics Modeling And Experimental Validation Of High-Strength Steel In Laser Powder Bed Fusion Process, M. Rangapuram, S. Babalola, J. W. Newkirk, L. N. Bartlett, F. W. Liou, K. Chandrashekhara, Stephen R. Cluff

Materials Science and Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a subset of the additive manufacturing process in which a laser beam selectively joins the metal powder into a desired part in a sequential layer process. Owing to its complex nature of rapid heating and cooling of the melt pool, there is a need to understand the melt pool behavior and its effects on the final manufactured part. a densely packed powder bed is highly desirable for fabricating a superior part using the LPBF process. in this work, discrete element model was used to generate powder beds with realistic powder properties and various factors …

Fabrication And Performance Of Scalable Bio-Engineered Porous Layers For Efficient Co2 Capture, Mary Sharon Rose Bondugula

Theses and Dissertations

This dissertation addresses the critical challenge of mitigating climate change by advancing CO2 capture technologies. As global CO2 emissions continue to rise, effective methods for capturing and separating CO2 from industrial processes are essential to combat climate change. Existing CO2 capture systems, such as Pressure Swing Adsorption (PSA) and Temperature Swing Adsorption (TSA), often rely on packed bed designs that face limitations, including poor heat and mass transfer, slow gas diffusion, and low thermal conductivity, reducing their efficiency. To overcome these challenges, this dissertation explores innovative solutions by developing advanced adsorbent coatings and scalable bed configurations.

This research begins by …

Prediction Of Dislocation Density During Casting Of 316 Stainless Steel Based Alloys As A Function Of Chromium And Nickel Composition, Abhishek Chitradurga Ranganath

All Theses

By the 1990s, computational methods were beginning to be used to study dislocation density in mental casting. Prior to that time research was based heavily on laboratory studies. This move was encouraged by the need to overcome limitations that experimental approaches had, including high costs and time-consuming processes, and needs of researchers to understand atomic-scale phenomena. Computational techniques allow complex materials to be simulated in cost effective way and can provide insight into behaviour that could never be determined through experimental methods alone.

This work utilized molecular dynamics (MD) simulations along with machine learning approaches to examine the dislocation density …

Synthesis And Doping Effects In Highly Conductive Chalcogenide Solid Electrolytes., Selim Halacoglu

Electronic Theses and Dissertations

Lithium and sodium ion batteries have been a vital component in the growth of small, portable electronic devices and EVs over the past 30 years. For future energy needs, changes to battery chemistry and composition will be necessary for two primary reasons: safer and higher energy batteries. Metal anodes have not seen widespread commercialization because of their propensity to react aggressively with the flammable liquid electrolytes commonly used in modern batteries. Non-flammable solid-state batteries (SSB) with solid electrolytes can safely be used with metal anodes, potentially providing a solution to both problems. The future perspective of safer battery is that …

High Energy Density Lithium-Ion Battery Materials., Rachel Dewees

Electronic Theses and Dissertations

Growth of the EV industry has created an increased demand for Li-ion battery electrode materials, and support of a robust lithium-ion battery supply chain is a national imperative. For mainstream acceptance in the American market, the range of EVs must be improved, i.e., the energy density of the battery must be increased. Increasing the specific capacity of the electrode materials is the most direct strategy for increasing the energy density of the battery. Silicon anode materials have a theoretical capacity of over 3700 mAh·g^-1 - an order of magnitude beyond that of the graphitic materials which are currently implemented. …

Magnetic Nano And Micro Rods As Tools For Characterizing Materials Mechanical Properties: Fundamentals And Applications, Artis Brasovs

All Dissertations

The focus of this dissertation is insect blood (Hemolymph). Hemolymph is analyzed by taking a materials science approach. Rheological characterization of hemolymph has been performed for the first time. Owing to a minute amount of available material, a new protocol was established where Magnetic Rotational Spectroscopy (MRS) with ferromagnetic nanorods was employed. The challenge was examining the microliter droplets' viscosity in less than a few minutes. This challenge was successfully resolved.

Blood is critical for the insect's survival: after wounding, the insect has to seal the wound quickly, in a few minutes. As the mechanism of fast clotting has never …

Improving Thermionic Power Generation Via The Reduction Of Emission Barriers, Chace E. Franey

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

This thesis investigates methods to improve the performance of thermionic energy converters (TECs) by reducing the emission barriers. A TEC generates electricity from thermal energy when electrons are emitted from a hot electrode (the emitter) through a vacuum gap and absorbed by a cooler electrode (the collector). Due to their lack of working fluids and inherently compact nature, TECs have garnered attention over the years for their potential as a means of power generation in space or high-grade waste heat recovery. Historically, however, the practical implementation of TECs has been hindered by significant technical challenges. Recent advancements in microfabrication techniques …

Electrochemical Treatment Of Mining And Oilfield Wastewater Using Recycled Titanium Alloy Electrodes, Sean Michael Thompsen

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

This thesis explores the integration of circular economy principles into wastewater treatment through the innovative use of recycled Ti-6Al-4V titanium alloy electrodes. By repurposing titanium alloys from metal additive manufacturing (AM) waste, the research aims to address the treatment of acidic and oil-contaminated industrial wastewater in a sustainable manner. The recycled electrodes demonstrate notable stability and fouling resistance in challenging acidic conditions, attributed to their unique surface porosity and conductive properties. Electrochemical processes, including hydrogen evolution at the cathode, facilitate metal ion precipitation and destabilize surfactant-stabilized oil droplets. Cyclic voltammetry and long-term stability tests highlight the electrodes’ resilience, providing an …

Development Of A Surface-Mounted Strong Post For The Midwest Guardrail System, Gnyarienn Selva Kumar

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

This research investigated the development of a surface-mounted strong post for the Midwest Guardrail System (MGS), designed to replicate the behavior of the standard MGS post, a W6 x8.5, 72-in. long post embedded 40 in. into strong soil. The MGS is a strong post, W-beam guardrail system that has been successfully evaluated in many applications using crashworthiness criteria described in the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). However, in some locations, conventional soil-embedded posts are impossible to install due to subgrade obstructions like concrete slabs, mow strips, utilities, and limited right-of-way. …

Synthesis And In Vitro Testing Of Mg-6zn-Xhap Biocomposites From Beef Bone As Biodegradable Bone Implant Material, Jojor Lamsihar Manalu, Francisca Tjhay, Theodora Kristoforus, Sovian Aritonang

Journal of Mechanical Engineering Science and Technology (JMEST)

This study aimed to develop biodegradable Mg-6Zn hydroxyapatite (Mg-6Zn HAp) biocomposites for potential use in bone replacement applications. The hydroxyapatite (HAp) powders, sourced from cow bone, were synthesized through an eco-friendly and cost-effective process, leveraging bioresources for material sustainability. The Mg-6Zn and HAp powders were mechanically mixed through ball milling for six hours to ensure homogeneity. The resultant powder mixture was then subjected to isostatic pressing at a high pressure of 570 MPa, forming a dense coin-shaped composite with a 1.5 cm diameter. This coin was consolidated in a capsule furnace at elevated temperatures for one hour to enhance material …

Analysis Of Tidal Energy Potential In The Merauke Papua River Waters Indonesia, Peter Sahupala, Daniel Parenden

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is as a source of information to study the potential of tidal energy at the estuary of the Maro River in the waters of Merauke Regency. This study uses a quantitative method, while the method for determining the location of the study used is the purposive sampling method where the data collection point is right at the end of the estuary of the Maro River because it faces directly onto the Arafura Sea. Tide data for 5 months, namely September 1, 2023 to January 31, 2024 with a pool area of 1,260,000 m2, with the …

Study On Thermal-Fluid-Solid Coupling Characteristics For Helicopter Intermediate Spiral Bevel Gear Reducer, Dongping Sheng, Jie Yang, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

In the helicopter transmission system, the intermediate reducer is particularly special. It uses bevel gear pairs to change the transmission direction and to transfer the rotational speed effectively. Therefore, an in-depth study of the spiral gear pair is crucial to improve the overall performance of the helicopter rotor system. This study focuses on the study of the thermal-fluid-solid coupling characteristics and one-way steady-state thermal finite element analysis are conducted based on volume of fluid multiphase flow simulation theory to provide strong support for the design and optimization of the helicopter intermediate reducer. Several conclusions could be obtained. Firstly, it could …

Characteristics Of Liquid Products From Spirulina Platensis Pyrolysis Under Microwave Irradiation With Activated Carbon Additive, Mohammad Mirza Yuniar Romaz, Sukarni Sukarni, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

Global energy consumption has surged due to the population's rapid growth, leading to a switch to using renewable and clean energy. Among various strategies for developing renewable and clean energy, biomass pyrolysis emerged as attractive, and microwave irradiation pyrolysis is a prominent technique. This research aims to determine the ideal parameters for microwave-assisted pyrolysis of Spirulina platensis (SP) microalgae in order to produce high-value liquid products with the addition of activated carbon (AC) additives. Liquid bio-oil products were characterized concerning their calorific value, chemical bonds, and thermal stability. This research also investigates product distribution as a function of AC loading. …

Optimization Of The Number Of Cylinder Blades In Coffee Pulper Machine: Finite Element Analysis And Simple Additive Weighting Methods, Mochamad Rifki Syahriza, Dwi Djumhariyanto, Nasrul Ilminnafik, Mahros Darsin, Danang Yudistiro, Hari Arbiantara Basuki, Robertoes Koekoeh Koentjoro Wibowo, Ahmad Syuhri, Sumarji Sumarji

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing interest in coffee in all circles means that coffee production and quality must always increase due to consumer demands. One way to maintain the quality of coffee beans is by breaking them down using a huller machine. This research aims to improve the optimization of coffee machines by modifying the cylinder blades of huller machines with variations of 3, 4, 5, and 7 cylinder blades in terms of static loading design and quality and production capacity of coffee bean breaking. The experiment was carried out using 400 rpm and breaking 10kg of dry coffee cherries every time the …

Simulation-Based Methodology To Investigate The Impact Of Material Type And Compressive Speed Variation On Effective Strain Rate And Springback, Radhi Nurvian Amrullah, Syamsul Hadi, Muhammad Akhlis Rizza

Journal of Mechanical Engineering Science and Technology (JMEST)

To obtain the desired results in the manufacturing process, especially the bending process, the occurrence of springback must be reduced. The effective strain rate must be increased to predict the increase in material. This study uses a simulation method to determine the influence of material type and compressive speed variation on spring back and effective strain rate. This study uses 3 kinds of materials: JIS SPHD, JIS A1100 BE, and JIS SN400A, and speed variations, namely: 90 mm/s, 105 mm/s, and 120 mm/s. This study shows that JIS SN400A material has the smallest springback value compared to JIS A1100 BE …

Turbine Engine Reliability Analysis Using Reliability Availability Maintainability (Ram), Oyong Novareza, Zefry Darmawan, Nasir Widha Setyanto, Effendi Bin Mohamad

Journal of Mechanical Engineering Science and Technology (JMEST)

Electrical energy is a vital necessity characterized by ever-increasing electricity consumption. The most dominating power plant in Indonesia in supplying electricity is the steam power plant, which is 50%. In its implementation, there is damage that occurs where the highest damage is to the general unit with the highest damage to the turbine unit. Therefore, the author uses the reliability, availability, and maintainability method or RAM. The purpose of this study is to determine the value of RAM on the turbine system at PLN and provide recommendations for improvements to system performance. The results showed that the MTTF and MTTR …

Innovative Approaches For Improving Orc Performance: A Review Of Pure Fluids, Zeotropic Mixtures, And Nanoparticles, Ebenezer Kumi, Vasudevarao Veeredhi, Christopher Enweremad

Journal of Mechanical Engineering Science and Technology (JMEST)

Although the organic Rankine Cycle (ORC) is said to effectively capture low-grade heat, its commercialization has been limited because of working fluid constraints and inefficiencies resulting from operating at low temperatures. This study reviews the working fluids used in organic Rankine cycles and examines how nanoparticles could enhance the efficiency of the ORC, by enhancing the thermophysical properties of the working fluids. Results from this review showed that zeotropic mixtures of pure fluids, provide a viable approach to improving the thermophysical characteristics of organic working fluids and have the potential to achieve thermo-economic performance superior to that of individual pure …

Innovations In Additive Manufacturing For Socket Fabrication: An Overview, Linda Ziyadatul Faiza, Wahyu Caesarendra, Wahyu Dwi Lestari

Journal of Mechanical Engineering Science and Technology (JMEST)

Additive Manufacturing (AM) has transformed the prosthetics industry, particularly in socket production, which plays a critical role in the comfort, fit, and functionality of prosthetic limbs. This article examines the latest advancements in AM technologies and their applications in socket fabrication. Key techniques like stereolithography (SLA), selective laser sintering (SLS), and fused deposition modeling (FDM) have facilitated the production of highly personalized, lightweight, and durable prosthetic sockets. These methods not only improve design precision but also allow for the use of biocompatible, flexible materials, enhancing both comfort and functionality. Digital design tools have streamlined the production process, reducing lead times …

Structural Simulation Of Wheelchair Ramp Using Finite Element Method, Bhre Wangsa Lenggana, Agung Nugroho, Ubaidillah Ubaidillah

Journal of Mechanical Engineering Science and Technology (JMEST)

Wheelchairs are essential mobility aids for people with disabilities, but they are often limited to flat surfaces and cannot overcome height differences. Portable ramps are an effective solution to overcome this limitation. This research aims to simulate and analyze the structure of a portable ramp for wheelchairs. Simulations were conducted using finite element method analysis software to assess the portable ramp's von Mises stress, deformation, and safety factor in various loading positions. Finite element method (FEM) analysis software was utilized to evaluate key mechanical properties, including von Mises stress, deformation, and safety factor, under different loading conditions and positions. The …

Analysis Of Biomass Briquette Mixed Bagasse And Sugarcane Peel On The Performance Of Forced Top-Lit Updraft Gasifier Stove, Intan Hardiatama, Aron Enruico, Yuni Hermawan, Muhammad Trifiananto, Skriptyan N.H. Syuhri

Journal of Mechanical Engineering Science and Technology (JMEST)

The population growth in Indonesia from 270 million in 2020 to 279 million in 2024 has increased LPG consumption, potentially leading to future fuel shortages. The top-lit updraft (TLUD) gasifier stove using renewable biomass materials, offers a sustainable alternative. Biomass such as bagasse and sugarcane peel can be optimized into charcoal briquettes with high calorific value and low emissions. The calorific value of briquettes can be further enhanced by blending other high–calorific biomass materials. This experimental research focuses on testing the calorific value of raw bagasse and sugarcane peel before carbonization, as well as briquette mixtures (70:30, 50:50, 30:70) using …

Characterization And Performance Nanofiltration Membranes In Water Quality For Goldfish (Carassius Auratus) Aquaculture, Inpita Casuarina Eqisetia Utari, Uun Yanuhar, Asus Maizar Suryanto Hertika, Heru Suryanto, Jibril Maulana, Nico Rahman Caesar, Mahrus Ismail, Leong-Seng Lim

Journal of Mechanical Engineering Science and Technology (JMEST)

Water quality is an important factor in aquaculture activities, including goldfish (Carassius auratus) farming. One approach to improving water quality is the use of nanofilters. This study aims to evaluate the performance of nanofilters made from Sargassum sp. with the addition of copper oxide nanoparticles. The method used involves the fermentation of bacterial cellulose from Acetobacter xylinum using Sargassum sp. extract as a medium, followed by homogenization and the addition of CuO-NPs at concentrations of 0.5%, 1%, and 1.5%, and subsequent oven drying. The nanofilter membrane will then be analyzed using SEM, XRD, and FTIR to characterize its properties. Performance …

The Potential Of Ramie Fiber As Reinforcement In Calcium Carbonate-Filled Polyester Resin Matrix Composites For Roofing Applications, Reinaldo Reinaldo, Djoko Setyanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Polymer matrix composite roofing materials available in the Indonesian market typically consist of 30%wt chopped strand mat glass fiber embedded in unsaturated polyester resin, filled with 30 parts per hundred resin (PHR) calcium carbonate. The aim of this research is to evaluate whether natural ramie fibers can potentially replace glass fibers. In the first stage of the study, we compared three types of natural fibers abundant in Indonesia: banana stem fibers, sugarcane bagasse, and ramie. Showed that ramie fiber performed the best. Its flexural strength, flexural modulus, and impact toughness were the highest, measured at 191.57 MPa, 6691 MPa, and …

Captivating Combustion Traits Of Bio-Oil Droplets Enriched With Bio-Additives From The Areca Shell Waste, Muhammad Alif Raehan, Helen Riupassa, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

Fuel derived from crude vegetable oil, such as coconut oil, holds promise as an alternative energy source to mitigate the increasing reliance on fossil fuels driven by population growth and industrial activities. The experiment involved suspending a single droplet of crude coconut oil mixed with activated carbon from areca shell waste and placed at the junction on R-type thermocouple (Pt/Pt-Rh13%). The droplets were ignited using a hot wire and subjected to atmospheric pressure and room temperature. Coconut oil comprises a saturated triglyceride carbon chain compound of approximately 91%, and areca shell waste possesses a porous structure that fosters favorable interactions …

Characterization Of Hydroxyapatite Derived From Scallop Shell Waste Synthesized By Sonochemical Method With Different Temperature Calcination, Diki Dwi Pramono, Poppy Puspitasari, Aminnudin Aminnudin, Jeefferie Abd Razak

Journal of Mechanical Engineering Science and Technology (JMEST)

One common bio-ceramic material used in the biomedical industry is hydroxyapatite. Because of its crystallographic and molecular resemblance to the hard tissues of the human body, hydroxyapatite is thought to form. Scallop shells are one natural source of hydroxyapatite, which is high in calcium. This study examines how the calcination temperature affects the characteristics of hydroxyapatite made from leftover scallop shell. Hydroxyapatite was synthesized via the sonochemical method, with calcination conducted at temperatures of 900°C, 1000°C, and 1100°C. The hydroxyapatite that was prepared was assessed using Xray diffraction (XRD) to determine the phase and crystallite size, Scanning Electron Microscopy (SEM) …

The Role Of Banana Peel Surface Pores Through Increasing Temperature For Efficient Hydrogen Production, Abid Fahreza Alphanoda, Erlanda Augupta Pane, Agus Riyanto, Avita Ayu Permanasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Porous carbon derived from banana peel has been synthesized by increasing the temperature range variation from 180 oC - 270 oC. The prepared carbon was tested in an experiment using double-chamber photoelectrochemistry to see the results of hydrogen production. SEM-EDX, FTIR, and TGA analyses identified all banana peel carbons. Optical and electrochemical properties were analyzed and measured by UV-Vis, Tauc Relationship, and Pearson Absolute Electronegativity. The amount of hydrogen gas produced from the simulation of UV-A visible light irradiation on variations of BP-240, BP-210, BP-180, and BPNatural. The surface of BP-270 has more pores and can produce the most significant …

Impact Of Natural Polymer Proportions On The Fire-Retardant Properties Of Bioplastics, I Gusti Ngurah Nitya Santhiarsa, Ni Made Dwidiani, I Gusti Ngurah Putu Tenaya, I Gede Artha Negara

Journal of Mechanical Engineering Science and Technology (JMEST)

This research investigates the influence of varying proportions of natural polymers on the fire-retardant properties of bioplastic. Tapioca starch (Manihot esculenta) and corn starch (Zea mays) were selected as the bioplastic materials, with different weight fractions employed in the analysis. These materials, as naturally occurring polymers, are biodegradable and serve as promising components in the development of bioplastics. Fire resistance testing was conducted in accordance with ASTM D635-03, utilizing weight ratios of tapioca to corn starch at 70:30, 60:40, and 50:50. The results included photographic documentation of each specimen alongside the corresponding outcomes from the fire resistance tests. These images …

Analysis Of Titanium Mesh Ti6al4v Formation Using Die Press Forming Machine For Cranioplasty, Ahmad Ayyub Syaiful Rizal, Mahros Darsin, Robertoes Koekoeh K. Wibowo, Khairul Anam

Journal of Mechanical Engineering Science and Technology (JMEST)

Cranioplasty is required for patients with head defects, where the deformed part of the head is replaced with Ti6Al4V titanium wire implants. The titanium wire forming process is usually done manually, which can take a long time and give results that do not match the anatomical shape of the head. Therefore, it is important to develop domestic technology that can produce titanium wire automatically. This study aims to analyze the frame and mold of the automatic wire mesh molding machine before production. The tool is made using press forming method and finite element analysis with ANSYS software. The machine frame …

The Effect Of Mixing Time And Rotation Speed On The Consistency Of Dough Viscosity In A Horizontal Mixer, Muhammad Akhlis Rizza, Ekky Yovianto Dharsono, Anggit Murdani, Ratna Monasari, Radhi Nurvian Amrullah, Supa Kusuma Aji, Dian Noorvy Khaerudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Cassava must go through several manufacturing processes before it becomes chips on the market, including the process of stirring the dough. The stirring process is an important stage in various food industries. In the stirring process, the viscosity change in the dough is influenced by various factors, including the stirring process time and speed in stirring. Research on dough viscosity is important because it is directly related to the quality of the final product. The purpose of this study is to provide recommendations to users, both in the context of using horizontal mixers and the process of making similar products. …