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Full-Text Articles in Fluid Dynamics

Exploring Red Palm Oil As A Sustainable Plasticizer For Carbon Black-Filled Ssbr/Br Tire Tread Compounds: A Comparative Evaluation Of Commercial Alternatives, Norma Arisanti Kinasih, Mohamad Irfan Fathurrohman, Santi Puspitasari, Dewi Kusuma Arti, Abdulhakim Masa Aug 2026

Exploring Red Palm Oil As A Sustainable Plasticizer For Carbon Black-Filled Ssbr/Br Tire Tread Compounds: A Comparative Evaluation Of Commercial Alternatives, Norma Arisanti Kinasih, Mohamad Irfan Fathurrohman, Santi Puspitasari, Dewi Kusuma Arti, Abdulhakim Masa

Journal of Materials Exploration and Findings

This study investigates the application of red palm oil (RPO) as an alternative vegetable oil resource to substitute petroleum-based plasticizers, which have environmental and health concerns, in carbon black (CB)-filled SSBR/BR tire tread compounds. The plasticizing effects of RPO were thoroughly evaluated by comparing them with a commercial bio-based plasticizer, Epoxidized Soybean Oil (ESBO), and two safer petroleum-based oils, Naphthenic Oil (NYNAS) and Treated Distillate Aromatic Extract (TDAE). The initial investigation shows that fatty acid composition is imposing regarding the plasticizing effect. The higher unsaturated fatty acid content in RPO than in ESBO improved tensile strength and degraded rolling resistance …


Metallurgical Investigation Of A Modified Eye Bolt Failure Caused By Improper Weld Extension, Specification Deviation, And Crevice Corrosion, Dimas Muhammad Fawwaz, Reza Miftahul Ulum, Johny Wahyuadi Soedarsono, Yudha Pratesa Aug 2026

Metallurgical Investigation Of A Modified Eye Bolt Failure Caused By Improper Weld Extension, Specification Deviation, And Crevice Corrosion, Dimas Muhammad Fawwaz, Reza Miftahul Ulum, Johny Wahyuadi Soedarsono, Yudha Pratesa

Journal of Materials Exploration and Findings

A modified eye bolt from the David Arm Manhole Storage Tank underwent thorough metallurgical study due to the consequences of the bolt's malfunction during operation. Safety issues arose when the manhole door detached during operation. The mechanical testing and chemical composition analysis of the bolts indicated they were manufactured from an ASTM A193 Grade B7 material used for high-temperature bolting. This material did not conform to the engineering drawing, which mentioned SA 563A, which is about nuts, not bolts. This contradiction clearly shows that the eye bolt which was installed does not conform to the intended design. Welded connections of …


Rejection Of Fe (Iron) And Kmno4 (Organic Substance) Parameters In Peat Water Using Organic Membranes, Muhamad Rafli Sakti Mulia Gonera, Siti Umi Kalsum, Sarah Fiebrina Heraningsih Aug 2026

Rejection Of Fe (Iron) And Kmno4 (Organic Substance) Parameters In Peat Water Using Organic Membranes, Muhamad Rafli Sakti Mulia Gonera, Siti Umi Kalsum, Sarah Fiebrina Heraningsih

Journal of Materials Exploration and Findings

Peat water is a surface water source widely used by people in swampy and lowland areas, but it has poor quality characteristics such as high organic matter content, low pH, and dissolved metal levels such as iron that exceed the threshold. These conditions can cause health problems and reduce the quality of clean water so that effective treatment technology is needed. This study aims to analyze the effectiveness of ultrafiltration membranes made from chitosan from shrimp shell waste in rejecting iron (Fe) and organic substances in peat water, and to determine the effect of pressure on separation performance. This study …


An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis May 2026

An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis

Civil and Environmental Engineering Theses and Dissertations

Urban areas are increasingly exposed to natural hazards while accommodating a growing share of the global population, yet a consistent science-based framework for quantifying urban and community resilience remains lacking. This dissertation develops a physics-based analytical framework grounded in statistical mechanics and the quantitative theory of Brownian motion. A city is conceptualized as a complex medium in which citizens move analogously to Brownian particles within a viscoelastic environment, influenced by socioeconomic interactions and infrastructure functionality.

A central premise is that urban resilience, interpreted as engineering resilience (an outcome), can be quantified through a single metric: the mean-square displacement MSD=⟨r²(t)⟩, of …


Feasibility Analysis Of Thermal Oxidizer To Determine Remaining Life Using Fitness- For-Service Level 3 Method, Yudhi Yudistirawan, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra, Dewi Kurnia Suci, Agung Putra Mahardhika Apr 2026

Feasibility Analysis Of Thermal Oxidizer To Determine Remaining Life Using Fitness- For-Service Level 3 Method, Yudhi Yudistirawan, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra, Dewi Kurnia Suci, Agung Putra Mahardhika

Journal of Materials Exploration and Findings

An aged thermal oxidizer (TOX) in the oil and gas industry necessitates a comprehensive evaluation to ensure its continued safe operation. This study presents a Remaining Life Assessment (RLA) and a Fitness for Service (FFS) evaluation for the four main components of the TOX, in accordance with API 510, API 579/ASME FFS-1, and ASME BPVC Section VIII Div-1 standards. The investigation includes the determination of maximum stress and maximum temperature required to assess the operational viability of the reactor. The four components are radiant, convection, transition, and stack sections—were modeled using the finite element method (FEM). Following the geometric modeling, …


Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi Dec 2025

Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi

Journal of Materials Exploration and Findings

The Fitness for Service (FFS) analysis is performed as a quantitative assessment to evaluate the integrity condition of a pipeline. Essentially, FFS assessment helps determine whether equipment components can operate safely despite existing deficiencies. This evaluation is carried out using the Finite Element Method (FEM). In the case of an underwater pipeline that experiences leak due to anchor pull at the flange connection, it undergoes plastic deformation and is lifted approximately 1 meter. As a mitigation step, inspection and repairs have been carried out by the company. Subsequently, modeling is performed to reconstruct the deformation process of the pipeline. Then, …


Assessment Of The Melt Quality Of A 30% Scrap Adc12 Aluminium Alloy Using The Inclusion And Fluidity Measurement Instrument (Ifmi) With Mullite Ceramic Filters, Gusti Ruri Ruri Lestari, Sandya Ananda Riswan, Muhammad Anis, Ahmad Ashari, Paramita Vidya Ayuningtyas, Bambang Suharno Prof, Donanta Dhaneswara Dec 2025

Assessment Of The Melt Quality Of A 30% Scrap Adc12 Aluminium Alloy Using The Inclusion And Fluidity Measurement Instrument (Ifmi) With Mullite Ceramic Filters, Gusti Ruri Ruri Lestari, Sandya Ananda Riswan, Muhammad Anis, Ahmad Ashari, Paramita Vidya Ayuningtyas, Bambang Suharno Prof, Donanta Dhaneswara

Journal of Materials Exploration and Findings

The increasing demand for sustainable practices in the metal casting industry has driven the use of recycled aluminum alloys such as ADC12. However, the addition of aluminum scrap tends to increase oxide inclusions, which reduce melt fluidity and compromise casting quality. This study utilizes the Inclusion and Fluidity Measurement Instrument (IFMI), equipped with mullite ceramic filters, to assess the melt quality of ADC12 aluminum alloy containing 30% scrap. Fluidity and inclusion characteristics were evaluated at five pouring temperatures (660°C, 680°C, 700°C, 720°C, and 740°C). The results show that fluidity increased with temperature, reaching a peak of 84.6 g·s⁻¹ at 740°C, …


Equipment Criticality Analysis To Determine Asset Integrity Management System Scheme In Supporting Production Optimization Scenarios In The Aeging Field, Donny Andryanto, Donanta Dhaneswara Dec 2025

Equipment Criticality Analysis To Determine Asset Integrity Management System Scheme In Supporting Production Optimization Scenarios In The Aeging Field, Donny Andryanto, Donanta Dhaneswara

Journal of Materials Exploration and Findings

This research investigates the production decline and cost increase in the X&Y oil and gas fields from 2022 to 2023. Production fell by 34%, while production costs per barrel rose by 79%. To address these issues, a series of optimization processes are proposed. These aim to restructure and enhance the production facilities to reduce current production costs. The optimizations include reducing pressure at the PPP Platform in 2024. Additional steps include shutting down CPP-ORF 14” pipelines and most processes at CPP 2 Platform by 2027 to convert it into an accommodation platform. Further, the plan involves optimizing the release of …


Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab Dec 2025

Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab

Journal of Materials Exploration and Findings

This study investigates the potential of ceramic membranes derived from areca nut fiber as a cost-effective and environmentally sustainable material for the removal of iron (Fe) and manganese (Mn) from groundwater. Two types of membranes were fabricated: one without activation and one chemically activated using 10% sodium hydroxide (NaOH). The morphological and elemental characteristics of both membranes were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) mapping. The concentrations of Fe and Mn before and after treatment were measured using Atomic Absorption Spectroscopy (AAS). The NaOH-activated membrane exhibited a more porous surface structure and higher oxygen content, …


A Study Of Wear Measurement And Life Prediction Of Insert Chute Liner On Gold Ore Processing, Ferry Ardika Natanael, Nony Maulidya, Dedi Priadi Aug 2025

A Study Of Wear Measurement And Life Prediction Of Insert Chute Liner On Gold Ore Processing, Ferry Ardika Natanael, Nony Maulidya, Dedi Priadi

Journal of Materials Exploration and Findings

Chutes are critical materials handling assets to transport solid particles from one process step to another in mineral processing, coal mining and cement industries. The material transport, because of material characteristics, cause severe wear on internal lining of chutes or bins’ structure. The wear problem on internal lining of bins or chutes needs to be checked to keep production efficiency. Therefore, not checked wear rate causes liner replacement schedule becomes unpredictable. It leads to production loss and highly cost maintenance in industry. This study shows that condition-based maintenance through regular thickness measurement using Ultrasonic Transducer (UT) to predict life service …


Techno-Enviro-Economic Approach For Electrification Of Rural And Shrimp Farming Regional Development Of An Isolated Island In Indonesia By Utilizing Hybrid Renewable Energy Systems, Fiqih Akbar Wijaya, Mohammad Akita Indianto Aug 2025

Techno-Enviro-Economic Approach For Electrification Of Rural And Shrimp Farming Regional Development Of An Isolated Island In Indonesia By Utilizing Hybrid Renewable Energy Systems, Fiqih Akbar Wijaya, Mohammad Akita Indianto

Journal of Materials Exploration and Findings

One of the challenges in developing and archipelagic countries such as Indonesia is maintaining energy demand in rural and isolated areas due to difficulties in electrical distribution. For instance, in areas like Bawean Island, no additional electricity capacity has been introduced in the past year, leading to an unmet potential customer demand. One of the possible options is by utilizing Hybrid Renewable Energy Systems (HRES) that are integrated with existing fossil fuel-based energy systems to support the growing energy demand in the remote island. A case study in Bawean Island is conducted with the projected energy demand covers the energy …


Remaining Life Assessment And Fitness For Service Evaluation Of Aging Chemical Reactors In Polyethylene Terephthalate Resin Industry, Aditya Pahlawan Munthe, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra Aug 2025

Remaining Life Assessment And Fitness For Service Evaluation Of Aging Chemical Reactors In Polyethylene Terephthalate Resin Industry, Aditya Pahlawan Munthe, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra

Journal of Materials Exploration and Findings

Aging chemical reactors in the polyethylene terephthalate (PET) resin industry require comprehensive evaluation to ensure safe continued operation. This study conducts a remaining life assessment (RLA) and fitness-for-service (FFS) evaluation on five 30-year-old reactors, based on API 510, API 579/ASME FFS-1, and ASME BPVC Section VIII Div. 1 standards. The analysis involves corrosion rate measurement, future corrosion allowance (FCA) projection, and minimum thickness verification. Among the reactors, R-120 was found to have the shortest remaining life less than 15 years. FFS assessments using three criteria Average Measured Thickness, MAWP from Point Thickness Readings, and Minimum Measured Thickness confirm that R-120 …


Analysis Of Leak Testing Planning For Carbon Dioxide Piping Systems In The Development Of Carbon Capture, Utilization, And Storage Facilities In The Bintuni Basin, Devi Sentiani, Akhmad Herman Yuwono Professor Aug 2025

Analysis Of Leak Testing Planning For Carbon Dioxide Piping Systems In The Development Of Carbon Capture, Utilization, And Storage Facilities In The Bintuni Basin, Devi Sentiani, Akhmad Herman Yuwono Professor

Journal of Materials Exploration and Findings

Carbon Capture, Utilization, and Storage (CCUS) technologies have become a key strategic response to global efforts to reduce CO2 emissions. This study presents a leak testing strategy designed for a carbon dioxide (CO₂) piping system as part of a Carbon Capture, Utilization, and Storage (CCUS) project in the Bintuni Basin, West Papua, Indonesia. This study aims to ensure the system is properly prepared before commissioning by designing a leak test plan that is both practical and technical, based on ASME B31.3, ASME PCC-2, and API STD 520 Part 1. We conducted the process, which involves identifying the system boundaries, …


Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa May 2025

Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa

Journal of Materials Exploration and Findings

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (pH₂S …


Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan May 2024

Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan

Journal of Materials Exploration and Findings

Metal matrix composite (MMC) with 7xxx aluminum matrix is potential for ballistic applications due to the combination of strength, toughness, and light weight. Previous study successfully produced aluminum-based composites with SiC particles which were able to stop type III bullet, however cracks remained on back of the plate. Therefore, in this research, SiC was replaced by zirconia (ZrO2) due to its high fracture toughness. Ti-B grain refiner was added to further improve toughness through grain boundary strengthening mechanism. This research developed 5 vol.% ZrO2 strengthened Al-10Zn-6Mg-2Si composite with addition of Al-5Ti-1B grain refiner produced through squeeze casting …


Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani May 2024

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …


Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, D. Rizal Asral, Donanta Dhaneswara Dec 2023

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, D. Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …


Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj Dec 2023

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N2) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …


Investigation Of The Effect Of Corundum Layer On The Heat Transfer Of Sic Slab, Sri Elsa Fatmi, Donanta Dhaneswara, Muhammad Anis, Ahmad Ashari Dec 2022

Investigation Of The Effect Of Corundum Layer On The Heat Transfer Of Sic Slab, Sri Elsa Fatmi, Donanta Dhaneswara, Muhammad Anis, Ahmad Ashari

Journal of Materials Exploration and Findings

Aluminum is the most widely used metal in industry. Aluminum smelting is one of the important steps that needs to be carried out to produce products made of aluminum metal with good quality. In the process of smelting aluminum there are several problems that occur, one of which is the growth of corundum in Si C refractories which affects the quality of aluminum melt and the durability of Si C refractories. This research was conducted to see the heat transfer in Si C and the effect of the presence of Corundum on heat transfer. This research was carried out by …


Dynamic Rbi With Central Difference Method Approach In Calculation Of Uniform Corrosion Rate: A Casestudy On Gas Pipelines, M.Riefqi Dwi Alviansyah, Fernanda Hartoyo, Zahra Nadia Nurullia, Ari Kurniawan Dec 2022

Dynamic Rbi With Central Difference Method Approach In Calculation Of Uniform Corrosion Rate: A Casestudy On Gas Pipelines, M.Riefqi Dwi Alviansyah, Fernanda Hartoyo, Zahra Nadia Nurullia, Ari Kurniawan

Journal of Materials Exploration and Findings

The oil and gas industry generally uses a piping system to drain fluids. Even though the pipes used have been well designed, the use of pipes as a means of fluid transportation still provides the possibility of failure that can occur at any time, one of which is due to uniform corrosion. The use of standard Risk Based Inspection (RBI) according to the API RBI 581 document has been widely used to anticipate potential failures to pipe components. The use of standard RBI can reduce the risk of failure significantly. Because the standard RBI considers the component risk value to …


Controlled Manipulation Of Droplets On Fibers: Fundamentals And Printing Applications, Yueming Sun Aug 2022

Controlled Manipulation Of Droplets On Fibers: Fundamentals And Printing Applications, Yueming Sun

All Dissertations

In this dissertation, the drop interactions with a single fiber is discussed under an application angle for the development on new Drop-on-Demand (DOD) printhead using a fiber-in-a-tube platform[1] to print highly viscous materials[2]. To control the drop formation and manipulation on fiber, one needs to know how the fiber wetting properties and the fiber diameter influence drop formation. And then, one needs to know the effects of fiber movement in the device on drop formation. These two questions constitute the main theme of this dissertation.

Before this study, it was accepted that the liquids could not form axisymmetric droplets if …


Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins May 2021

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive silicone model …


Optimisation Of Retrofit Wall Insulation: An Irish Case Study, Rakshit D. Muddu, D M. Gowda, Anthony James Robinson, Aimee Byrne Jan 2021

Optimisation Of Retrofit Wall Insulation: An Irish Case Study, Rakshit D. Muddu, D M. Gowda, Anthony James Robinson, Aimee Byrne

Articles

Ireland has one of the highest rates of emissions per capita in the world and its residential sector is responsible for approximately 10% of total national CO2 emissions. Therefore, reducing the CO2 emissions in this sector will play a decisive role in achieving EU targets of reducing emissions by 40% by 2030. To better inform decisions regarding retrofit of the existing building stock, this study proposes Optimum Insulation Thicknesses (OIT) for typical walls in 25 regions in Ireland. The calculation of OIT includes annual heat energy expenditure, CO2 emissions, and material payback period. The approach taken is based on Heating …


Epitaxial Growth Of Semi-Polar (11-22) Gallium Nitride For Uv Photosensing Application, Abdullah Haaziq Ahmad Makinudin Dec 2020

Epitaxial Growth Of Semi-Polar (11-22) Gallium Nitride For Uv Photosensing Application, Abdullah Haaziq Ahmad Makinudin

Student Works (2020-2029)

Semi-polar (11-22) gallium nitride (GaN) epilayers have attracted numerous interests in GaN based technology as it possess significant advantages over its polar (c-plane) counterparts such as low to none spontaneous and piezoelectric polarization which is known to impair the device performance. However, growth along semi-polar (11-22) orientation has been known to exhibit numerous defect densities such as dislocations and stacking faults (SFs). In order to acquire high quality semi-polar (11-22) GaN epilayers, various growth optimizations must be employed. In this work, the semi-polar (11-22) GaN epilayers were grown on planar m-plane sapphire substrate with the use of a 2-inch capability …


Thermo-Fluid Characterizations Of The Powder-Bed Fusion Additive Manufacturing Processes Using Laser And Electron Beam, M Shafiqur Rahman Dec 2020

Thermo-Fluid Characterizations Of The Powder-Bed Fusion Additive Manufacturing Processes Using Laser And Electron Beam, M Shafiqur Rahman

LSU New Orleans Theses and Dissertations

The powder-bed fusion (PBF) process is a subdivision of Additive Manufacturing (AM) technology where a heat source at a controlled speed selectively fuses regions of a powder-bed material to form three-dimensional (3-D) parts. Two of the most effective PBF processes are selective laser melting (SLM) and electron beam additive manufacturing (EBAM), which can fabricate full-density metallic parts in a layer-by-layer fashion. In this study, thermal behavior and melt-pool dynamics in the PBF process are investigated by developing 3-D multiphysics-based thermo-fluid models for both SLM and EBAM, containing Ti-6Al-4V alloy as a powder-bed material. The laser and electron beams are modeled …


A Soft-Robotic Harbor Porpoise Pectoral Fin Driven By Coiled Polymer Actuators As Artificial Muscles, Robert Hunt, Sarah Trabia, Zakai Olsen, Kwang Kim Jun 2019

A Soft-Robotic Harbor Porpoise Pectoral Fin Driven By Coiled Polymer Actuators As Artificial Muscles, Robert Hunt, Sarah Trabia, Zakai Olsen, Kwang Kim

Mechanical Engineering Faculty Research

Biomimicry is an approach in science and engineering to overcome human challenges by designing materials and systems modeled after nature. Selected applications of biomimicry include catheters, hearing devices, and artificial appendages such as arms, legs, and fingers. The inspiration for this study is the hydrofoil-like structured pectoral fin of the harbor porpoise whale that is ultimately useful for studying fluid-structure interactions, drag, lift, and laminar-to-turbulent transitions. The pectoral fin is fabricated by manipulating computed tomography (CT) scans into 3D models using Simpleware ScanIP and post-processed in Autodesk for printing. An array of thermally driven coiled polymer actuators (CPA) fabricated from …


Direct Numerical Simulation Of Roughness Induced Hypersonic Boundary Layer Transition On A 7° Half-Angle Cone, Tara E. Crouch Mar 2019

Direct Numerical Simulation Of Roughness Induced Hypersonic Boundary Layer Transition On A 7° Half-Angle Cone, Tara E. Crouch

Theses and Dissertations

Direct numerical simulation (DNS) computational fluid dynamic (CFD) calculations were performed on a 30° slice of 7° half-angle cones with increasing nose radii bluntness at Mach 10 while simulating a distributed roughness pattern on the cone surface. These DNS computations were designed to determine if the non-modal transition behavior observed in testing performed at the Arnold Engineering Development Center (AEDC) Hypervelocity Wind Tunnel 9 was induced via distributed surface roughness. When boundary layer transition is dominated by second mode instabilities, an increase in nose radius delays the transition location downstream. However, blunt nose experiments indicated that as the nose radius …


Swelling As A Stabilizing Mechanism During Ion Bombardment Of Thin Films: An Analytical And Numerical Study, Jennifer M. Swenson Apr 2018

Swelling As A Stabilizing Mechanism During Ion Bombardment Of Thin Films: An Analytical And Numerical Study, Jennifer M. Swenson

Mathematics Theses and Dissertations

Irradiation of semiconductor surfaces often leads to the spontaneous formation of rippled structures at certain irradiation angles. However, at high enough energies, these structures are observed to vanish for all angles, despite the absence of any identified, universally-stabilizing physical mechanisms in operation. Here, we examine the effect on pattern formation of radiation-induced swelling, which has been excluded from prior treatments of stress in irradiated films. After developing a suitable continuum model, we perform a linear stability analysis to determine its effect on stability. Under appropriate simplifying assumptions, we find swelling indeed to be stabilizing at wavenumbers typical of experimental observations. …


Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao Oct 2016

Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Puddle Jumping: Spontaneous Ejection Of Large Liquid Droplets From Hydrophobic Surfaces During Drop Tower Tests, Babek Attari, Mark M. Weislogel, Andrew Paul Wollman, Yongkang Chen, Trevor Snyder Oct 2016

Puddle Jumping: Spontaneous Ejection Of Large Liquid Droplets From Hydrophobic Surfaces During Drop Tower Tests, Babek Attari, Mark M. Weislogel, Andrew Paul Wollman, Yongkang Chen, Trevor Snyder

Mechanical and Materials Engineering Faculty Publications and Presentations

Large droplets and puddles jump spontaneously from sufficiently hydrophobicsurfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 104 times larger than their normal terrestrial counterparts. We provide and/or confirm quick and qualitative design guides for such “drop shooters” as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, and fluid properties including contact angle. The latter is determined via profile image comparisons with numerical …