Materials Science and Engineering Commons^™

Removal Capabilities Of Zeolite And Zero Valent Iron With High-Level Waste Tank Radionuclides And Metals: Cesium, Strontium And Chromium, Colette R. Towles

UNLV Theses, Dissertations, Professional Papers, and Capstones

High level nuclear waste (HLW) has been disposed for temporary storage in underground steel tanks at the Department of Energy Nuclear sites. For example, at the Hanford Site, WA, and Savannah River Site (SRS), SC, HLW account for eighty-eight million gallons (Mgal) and 450 million Curies (MCi) of radioactivity. In the early nuclear activity at Hanford, the waste was discharged to single-shell steel tanks, and the lack of secondary containment allowed leaks, contaminating soil and groundwater. Despite tremendous efforts to stabilize the liquid waste at nuclear sites, treatment is complex, costly, and time-consuming; therefore, HLW may have to be stored …

Advancing Biofabrication Methodologies To Develop Biomimetic Tissue Scaffolds For Musculoskeletal Applications, Nashaita Yezdi Patrawalla

Theses and Dissertations

Musculoskeletal injuries impose a significant global burden, affecting millions and generating an economic toll exceeding $14 billion. Tissue engineering has gained traction as a promising strategy offering potential for functional restoration of damaged musculoskeletal tissues. This research aims to advance biofabrication techniques for generation of biomimetic tissue scaffolds, by optimizing scaffold design and modulating fabrication process parameters to generate scaffolds for musculoskeletal regeneration with application-specific tailored properties. In this realm, collagen-based biomaterials have been extensively investigated for tendon and ligamentous applications, and in combination with bioceramics incorporated into the collagen framework to produce composite scaffolds that better recapitulate the native …

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. …

Cyclic Thermal Stability Of Native Oxide Solar Thermal Absorbers On Femnnialcr High Entropy Alloys For Energy Applications, Xiaoxue Gao

Dartmouth College Ph.D Dissertations

High entropy alloys (HEAs) are promising candidates for cost-effective high-temperature materials in high-efficiency power cycles. A potential application is in concentrated solar power (CSP) systems, where native oxides of cost-effective FeMnNiAlCr HEAs can also synergistically serve as a high-efficiency solar thermal absorber. However, the huge and repetitive temperature change of the CSP system in day-night cycles greatly challenges its thermal stability. In this thesis, we investigated the cyclic oxidation behavior of FeMnNiAlCr HEAs to improve the optical performance and thermal stability of their native oxides as a solar absorber for next-generation CSP systems. We found that the duplex oxide scale …

Understanding Defect Dynamics In Black Phosphorene Under Noble Gas Ion Irradiation., Saransh Gupta

Electronic Theses and Dissertations

Controlled introduction of defects in phosphorene using high-energy ion beams offers a promising route to design novel high-performance materials for energy technologies. However, this potential remains underexplored due to a lack of fundamental understanding of the atomic-scale mechanisms governing the production, accumulation, and temporal evolution of defects during ion irradiation. Here, we employ a combination of classical and ab initio molecular dynamics simulations to elucidate the effects of ion energy, angle of incidence, noble gas ion size/mass, and fluence on (a) defect generation (i.e., point defects, topological imperfections, voids), (b) atomic-scale mechanisms of defect formation and re-arrangement, and (c) defect …

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. …

Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper presents the results of thermal conductivity characterization of six high oleic soybean oil (HOSO) and four high oleic canola oil (HOCO)-Based hybrid nanofluids formulated with four types of nanoparticles (Graphene nanoplatelet (xGnP), TiO₂, MoS₂, and Al₂O₃) at nanoparticles wt.% concentration from 1 % to 7 % in 1 % increment using the two-step method for use in MQL machining of difficult-to-cut metals. Thermal conductivity of the formulated hybrid nanofluids were measured using Thermtest Transient Hot Wire Liquid Thermal Conductivity Meter at temperatures from 25 °C to 75 °C in increment …

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …

Investigating Functionalized Cvd Graphene Heterostructures As Platforms For Hydrogen Gas Sensing, Evans Asiedu Addo-Mensah

Graduate Theses and Dissertations

The hydrogen economy is rapidly advancing and is poised to become one of the world's largest economies, driven by the abundance of hydrogen gas. Several organizations, particularly in the United States of America, are closely or have been monitoring this development, with rapidly increasing interest. Considering that hydrogen gas has no taste, smell (odor), or color, and very combustible, it’s imperative to develop detectors and sensors capable of rapidly detecting leaks to prevent application disasters. Owing to its extraordinary mechanical and electrical characteristics, graphene is the material that has been studied the most. When combined with hexagonal boron nitride (hBN), …

Modeling, Synthesis, And Experimental Characterization Of Rhenium Disulfide For Optoelectronic Devices, Solomon Opeyami Ojo

Graduate Theses and Dissertations

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have garnered considerable interest for their potential in optoelectronics and photonics owing to their remarkable combination of electronic, optical, and mechanical properties. These characteristics distinguish them from other 2D materials, including graphene, making them particularly valuable for next-generation technologies. This dissertation focuses on ReS_₂, a 2D TMD with a unique anisotropic 1T distorted crystal structure. The research aims to elucidate its fundamental properties through a combination of theoretical modeling, material synthesis, and experimental characterization techniques, with the goal of optimizing ReS_₂ for device applications. A theoretical investigation utilizing Density Functional Theory …

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 …

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 …

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 …

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 …

Tactical Activities To Improve The Effectiveness Of Concrete Batching Plant Based On Overall Equipment Effectiveness Analysis, Yurida Ekawati, Iddo Christian Sutrisno, Teguh Oktiarso

Journal of Mechanical Engineering Science and Technology (JMEST)

The growth of infrastructure projects has led to an increased demand for ready-mix concrete. A company that produces ready-mix concrete using a batching plant encountered difficulties in fulfilling customer orders due to the high rate of machine downtime. Overall equipment effectiveness (OEE) was employed to examine these issues at the tactical activities, where the root causes of losses that occur in the OEE components of availability, performance, and quality were addressed. The OEE analysis was extended to encompass maintenance effectiveness measures, as the anticipated solution to the problem was not the replacement of the machine, but rather an enhancement of …

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 …

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 Influence Of Sodium Chloride Treatment On The Sisal Fiber Bundle’S Properties, Tamaryska Setyayunita, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Currently, composite board manufacturing using natural fiber has the potential to be expanded due to environmental awareness. To produce high-performance natural fiber, treatment is needed to improve natural fiber’s mechanical and physical properties. One of chemical treatments is by using sodium chloride (NaCl). This study aimed to investigate the characteristics of sisal fiber after NaCl treatment. The concentrations of NaCl treatment were 1, 3, and 5 (wt.%) at room and boiling temperature and the soaking duration was 1 hour. Meanwhile, tensile strength, strain, and Young’s modulus were tested to evaluate the mechanical properties. Fiber bundle diameter, weight change due to …

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 …

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. …

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 …

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 …

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 …

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 …

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 …