Review Of Materials, Functional Components, Fabrication Technologies And Assembling Characteristics For Polymer Electrolyte Membrane Fuel Cells (Pemfcs) – An Update,
2023
Chulalongkorn University
Review Of Materials, Functional Components, Fabrication Technologies And Assembling Characteristics For Polymer Electrolyte Membrane Fuel Cells (Pemfcs) – An Update, Arun Daya, Arputharaj Samson Nesaraj
Journal of Metals, Materials and Minerals
Fuel cells use electrochemical processes to transform the chemical energy of a fuel into electrical energy, which is a key enabler for the shift to an H2-based economy. Because of their high energy conversion efficiency and low pollution emissions, fuel cells with polymer electrolyte membranes (PEMFCs) are regarded as being in frontline of commercialization for the transportation and automotive industries. However, there are two major hurdles to their future commercialization: cost and durability, which promote basic study and development of their components. In this article, we reviewed the materials, functional components, fabrication technologies and assembling characteristics related to PEMFCs. Platinum's …
Structure And Chemical Durability Improvement Of Alkali Silicate Glass By Zirconium Dioxide And Erbium Oxide Addition,
2023
Chulalongkorn University
Structure And Chemical Durability Improvement Of Alkali Silicate Glass By Zirconium Dioxide And Erbium Oxide Addition, Ativit Denprawat, Kittipong Sinwanasarp, Pinit Kidkhunthod, Nattapol Laorodphan, Worapong Thiemsorn
Journal of Metals, Materials and Minerals
Glass structure tailoring of alkali silicate glasses by addition of ZrO2 and Er2O3 is found to enhance the chemical durability of glasses. ZrO2 (x ranged between 5 mol% to 15 mol%) and Er2O3 (y ranged between 0.5 mol% to 1.5 mol%) were used to replace SiO2 and Na2O, respectively, in the glasses with the nominal composition of 10Li2O-(15-y)Na2O-10CaO-(65-x)SiO2-xZrO2-y Er2O3. The samples were prepared by conventional melt quenching technique. The structures of produced glasses were examined by X-ray absorption spectroscopy (XAS) and Raman spectroscopy. XAS spectra demonstrated that the oxidation numbers of Zr and Er ions were +4 and +3, respectively. …
Quantum-Based First-Principles Study Of Gas Molecules (O2 , Co2 , No2 ) Interaction On Monolayer Germanene,
2023
Chulalongkorn University
Quantum-Based First-Principles Study Of Gas Molecules (O2 , Co2 , No2 ) Interaction On Monolayer Germanene, Arief Hermanto, Harmon Prayogi, Ari Dwi Nugraheni, Juliasih Partini, Sholihun Sholihun
Journal of Metals, Materials and Minerals
We perform calculations of the adsorption energy of O2, CO2, and NO2 molecules on germanene by using the density functional theory (DFT). We find two favorable configurations for O2, the U-site and V-site configurations with similar adsorption energies of -4.10 and -4.32 eV. As for NO2, we find two favorable configurations, the T-site and DB-site configurations. The T-site configuration is 0.98 eV more stable than the IB-site one, and both configurations are chemically adsorbed by germanene. On the contrary for CO2, we find a T-site configuration with adsorption energy of 0.42 eV and the configuration physically adsorbed by germanene.
Synthesis And Modification Of Nickel Hydroxide Particle Synthesized By Self-Assembly And Electron Beam Irradiation Technique For Photocatalyst Activity,
2023
Chulalongkorn University
Synthesis And Modification Of Nickel Hydroxide Particle Synthesized By Self-Assembly And Electron Beam Irradiation Technique For Photocatalyst Activity, Narisara Saechin, Sumitra Sripho, Thitirat Rattanawongwiboon, Sakchai Laksee, Pattra Lertsarawut, Wilasinee Kingkam, Sarute Ummartyotin
Journal of Metals, Materials and Minerals
The purpose of this work is to study the methyl orange removal of Ni(OH)2 nanoparticles. The photo-catalyst activity is investigated based on UV lamp of 18 watt. Ni(OH)2 is synthesized by a self-assembly process and then exposed to electron beam radiation at 10 MeV energy with various doses ranging from 50 kGy to 500 kGy. The properties of Ni(OH)2 nanoparticles are then evaluated. No significant change of functional group and percent of crystallinity are observed. The morphology is uniformly presented as a plate-like. The specific surface area, pore size and pore volume are reduced. Point of zero charge confirmed that …
Effect Of Calcination Frequency On The Thermoelectric Properties Of Ti Doped Cucro By Solid State Method,
2023
Chulalongkorn University
Effect Of Calcination Frequency On The Thermoelectric Properties Of Ti Doped Cucro By Solid State Method, Doli Bonardo, Nono Darsono, Syahrul Humaidi, Agung Imaduddin, Noni Surtiana Silalahi
Journal of Metals, Materials and Minerals
In this study, the influence of titanium oxide (TiO2) dopants and varying calcination processes on the thermoelectric properties of CuCrO2 was systematically explored. It was emphasized that these factors were not only affecting dislocation density but also exerting a profound influence on thermoelectric performance through the modulation of Seebeck coefficient and resistivity. The findings highlighted CrT-2, which incorporated TiO2 and underwent a two-time calcination process, as the top-performing sample in terms of power factor values, underscoring the significance of TiO2 as a dopant for enhancing thermoelectric efficiency. Conversely, Cr-4, exposed to four calcination cycles, exhibited slightly lower power factor values …
Electrical And Water Resistance Properties Of Conductive Paste Based On Gold/Silver Composites,
2023
Chulalongkorn University
Electrical And Water Resistance Properties Of Conductive Paste Based On Gold/Silver Composites, Sutthipoj Wongrerkdee, Supab Choopun, Pichitchai Pimpang
Journal of Metals, Materials and Minerals
This study aimed to investigate the effects of a corrosive environment on both the electrical and the water resistance properties of conductive paste based on gold/silver composites. The conductive paste was prepared by incorporating silver and gold powders, polyvinyl acetate, polyvinyl chloride as adhesive components, and methyl isobutyl ketone as a diluent. The gold/silver composite powder was prepared with different mass ratios of gold and silver. The paste was coated on a substrate and heated at 80℃ to form the conductive paste film. Characterizations of conductive paste were performed by using FT-IR spectroscopy, electrometry, cyclic voltammetry, and contact angle measurements. …
Molybdenum Disulfide-Zirconium Dioxide Composite With Enhance Supercapacitance Performance,
2023
Chulalongkorn University
Molybdenum Disulfide-Zirconium Dioxide Composite With Enhance Supercapacitance Performance, Razan Nadhim Shaker, Sami Mohammed, Yousra Ali Abdulsayed
Journal of Metals, Materials and Minerals
As a supercapacitor active material, molybdenum disulfide (MoS2) layer offers good conductivity, large surface area, and electrochemical stability. In practice, however, its capacitance is low in comparison to other materials. This work synthesized MoS2-zirconium dioxide (ZrO2) composite in a simple, high-throughput way to test it as a supercapacitor active layer. During the tests, the composite shows a gravimetric capacitance of 500.0 F⸳g-1, while MoS2 and ZrO2 have capacitances of 265.12 and 152.43, respectively. The increase in capacitance of composite stems from the synergistic effect between ZrO2's pseudocapacitor behavior and MoS2's electric double layer capacitance (EDLC). Moreover, the composite has a …
Dome Tester,
2023
The University of Akron
Dome Tester, Clark Bates, Nikolas M. Kulin
Williams Honors College, Honors Research Projects
We are reconfiguring and modifying the previously built dome tester to be more user friendly and mechanically applicable. This has a long-term goal of being a usable teaching tool for manufacturing education within the college of engineering and polymer sciences. The dome tester pushes a metal dome into a clamped sheet of metal to test its forming limits and where necking occurs. We have implemented a better method of viewing the sheet sample as it is being deformed, and improved measuring methods for the distance a sample is deformed. By introducing these changes in conjunction with improved documentation of the …
Wetting Transition Of Texturized Surfaces,
2023
The University of Akron
Wetting Transition Of Texturized Surfaces, Jenna Stephens
Williams Honors College, Honors Research Projects
Building on previous research, this project aims to continue the investigation of the wettability of various liquids on a uniform, texturized surface. Different surface energies can impact the wettability of a surface. The surface can be hydrophilic, hydrophobic, or in between. The goal of this project is to research how features of texturized surfaces affect the wetting transition of water, oil, and a mixture of both. Additionally, this project aims to improve the quality of the 3D printed surfaces. The surfaces that will be studied are constructed using UV cured resin 3D printing and are made up of an array …
Defining The Proper Operating Time For The Septa Extractor,
2023
The University of Akron
Defining The Proper Operating Time For The Septa Extractor, Abigail Jones
Williams Honors College, Honors Research Projects
Anionic polymerizations are a common type of reaction used to produce synthetic rubber. During these reactions, it is necessary to charge initiators, modifiers, and other substances, through pressurized containers that are sealed with rubber septa. These septa prevent oxygen and moisture from entering the pressurized container, and the reactor, though they need to be cleaned before use to remove other impurities. Currently a glass Soxhlet Extractor is used to remove such impurities, and though effective, it has a limited capacity, so it has to run frequently. This limitation led to the commissioning of the Septa Extractor, which is an automated …
Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy,
2023
Missouri University of Science and Technology
Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank W. Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Nanostructured Steels Are Expected to Have Enhanced Irradiation Tolerance and Improved Strength. However, They Suffer from Poor Microstructural Stability at Elevated Temperatures. in This Study, Fe–21Cr–5Al–0.026C (Wt%) Kanthal D (KD) Alloy Belonging to a Class of (FeCrAl) Alloys Considered for Accident-Tolerant Fuel Cladding in Light-Water Reactors is Nanostructured using Two Severe Plastic Deformation Techniques of Equal-Channel Angular Pressing (ECAP) and High-Pressure Torsion (HPT), and their Thermal Stability between 500–700 °C is Studied and Compared. ECAP KD is Found to Be Thermally Stable Up to 500 °C, Whereas HPT KD is Unstable at 500 °C. Microstructural Characterization Reveals that ECAP KD …
Development Of Inconel 718f And Inconel 718e Powders For Parts Manufacturing Utilizing Binder Jet Three-Dimensional Printing And Compressed Pellet Methods,
2023
West Virginia University
Development Of Inconel 718f And Inconel 718e Powders For Parts Manufacturing Utilizing Binder Jet Three-Dimensional Printing And Compressed Pellet Methods, Duncan Eric Manor Ii
Graduate Theses, Dissertations, and Problem Reports (ETD)
Alloy Inconel 718 is a Ni based superalloy used for high temperature applications including turbine blades, turbocharger rotors and nuclear reactors. Inconel 718 is a popular commercial atomized powder that has limitations in performance for use in additive manufacturing applications due to poor part quality and efficiency of current fabrication methods. Developing new compositions and additive manufacturing (AM) methodologies of IN718 is critical to improve the quality and the efficiency of IN718 parts manufacturing. Developing new additive manufacturing methodology that produces higher quality parts made of IN718 as compared to current methods has the potential to greatly impact industry, academia, …
Manganese-Based A-Site High-Entropy Perovskite Oxides For Solar Thermochemical Hydrogen Production,
2023
West Virginia University
Manganese-Based A-Site High-Entropy Perovskite Oxides For Solar Thermochemical Hydrogen Production, Cijie Liu
Graduate Theses, Dissertations, and Problem Reports (ETD)
Non-stoichiometric perovskite oxides have been studied as a new family of redox oxides for solar thermochemical hydrogen (STCH) production owing to their favourable thermodynamic properties. However, conventional perovskite oxides suffer from limited phase stability and kinetic properties, and poor cyclability. Here, we report a strategy of introducing A-site multi-principal-component mixing to develop a high-entropy perovskite oxide, (La1/6Pr1/6Nd1/6Gd1/6Sr1/6Ba1/6)MnO3 (LPNGSB_Mn), which shows desirable thermodynamic and kinetics properties as well as excellent phase stability and cycling durability. LPNGSB_Mn exhibits enhanced hydrogen production (~77.5 mmol moloxide–1) compared to (La …
Development Of High Kinetic Inductance Superconducting Nanowire Devices On High Permittivity Strontium Titanate Substrates,
2023
University of North Florida
Development Of High Kinetic Inductance Superconducting Nanowire Devices On High Permittivity Strontium Titanate Substrates, Jamie Timmons
UNF Graduate Theses and Dissertations
This thesis involves the fabrication and characterization of devices made from two different superconducting materials: yttrium barium copper oxide (YBCO), a high-TC complex oxide, and niobium nitride (NbN), a low-TC transition metal nitride. Both types of devices are fabricated on strontium titanate substrates, which provides a good lattice match to YBCO and also an extremely large permittivity at low temperature. We demonstrate that wet etching of YBCO thin films via bromine can be a viable microfrabriation technique for the material. Using approximately 35 nm thick epitaxially grown YBCO on an STO substrate, we were able to fabricate YBCO “microwires” with …
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens,
2023
Georgia Southern University
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez
College of Graduate Studies: Theses & Dissertations
Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …
Understanding The Feasibility Of Improving Interfacial Properties In Direct Ink Writing Of Silicone-Polyurethane Resin Hybrid Material,
2023
Georgia Southern University
Understanding The Feasibility Of Improving Interfacial Properties In Direct Ink Writing Of Silicone-Polyurethane Resin Hybrid Material, Ayobami Samuel Akinfenwa
College of Graduate Studies: Theses & Dissertations
The progress in materials engineering and the ability to make various models possible have made soft robotics a popular alternative to traditional robotics. Still, soft robots need various parts, like Printed Circuit Boards (PCBs), batteries, cables, fittings, and more, to work correctly or to get attached to other complex parts. These parts can have different material properties, like elastic moduli, strength, etc. Because of these differences, mechanical failures happen at the points where two materials meet, making soft robots less durable and less lasting in real-life situations due to failure. Conventionally, the fabrication of soft robot parts is through moulding. …
Design And Fabrication Of A High-Performance Heat Exchanger Using An Optimized Three-Dimensional Surface Structure Through Additive Manufacturing,
2023
Georgia Southern University
Design And Fabrication Of A High-Performance Heat Exchanger Using An Optimized Three-Dimensional Surface Structure Through Additive Manufacturing, Seth T. Waters
College of Graduate Studies: Theses & Dissertations
A heat exchanger is a device used to transfer thermal energy between two intertwining fluid pathways. In this study, the design of a novel heat exchanger is proposed using functional gradient double gyroid structure. The complex internal geometries of the gyroid structure significantly increases the surface area to volume ratio, and potentially could expressively improve efficiency of the heat transfer. The proposed idea provides a new approach for the design of a high-efficiency heat exchanger. In order to fabricate the complex structured heat exchanger system additive manufacturing is adapted instead of traditionally subtractive manufacturing techniques or casting. The prototypes of …
Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding,
2023
Virginia Commonwealth University
Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu
Theses and Dissertations
This dissertation emphasizes the need for efficient energy use in buildings and transportation due to global warming and the energy crisis. It suggests that improving energy efficiency can help reduce energy consumption and emissions and support sustainability. The dissertation introduces various transparent materials that can block near-infrared (NIR) radiation from solar radiation to save energy and money, and it highlights the growing market value of such products. The dissertation compares tungsten bronze with other NIR shielding materials and shows its advantages. The dissertation introduces a cheap and environmentally friendly method for continuously producing tungsten bronze particles via aerosol synthesis. Particle …
An Updated Analytical Method For Predicting The Bracing Behavior Of Z-Purlin Supported Standing Seam Diaphragm Systems,
2023
Old Dominion University
An Updated Analytical Method For Predicting The Bracing Behavior Of Z-Purlin Supported Standing Seam Diaphragm Systems, Michael W. Seek
Engineering Technology Faculty Publications
Roof systems utilizing Z-purlins as a secondary member supporting a standing seam panel system are used extensively by the metal building industry. The Z-purlins rely on the diaphragm action in the standing seam panel system to provide lateral support and transfer forces to anchorages. The behavior of the standing seam system is highly nonlinear making prediction of the interaction between the Z-purlin and the standing seam system difficult. To better understand the behavior of the interaction between the purlins and the panel system, a series of non-linear shell finite element models were developed based on the test results of simple …
Radiation Shielding Effectiveness Of Hafnium Diboride (Hfb2) Reinforced Epoxy Composites For Enhanced Radiation Protection And Safety,
2023
Virginia Commonwealth University
Radiation Shielding Effectiveness Of Hafnium Diboride (Hfb2) Reinforced Epoxy Composites For Enhanced Radiation Protection And Safety, Furkan Erdogan
Theses and Dissertations
This thesis investigates the radiation shielding effectiveness of hafnium diboride (HfB2) reinforced epoxy composites, with the aim of enhancing radiation protection and safety in various applications. The study focuses on the development and characterization of HfB2-epoxy composites with varying weight percentages of HfB2 nanoparticles, as well as on the evaluation of their shielding effectiveness against gamma rays and thermal neutrons. The radiation shielding performance of the composites is assessed using gamma-ray spectroscopy and neutron counting, and the neutron attenuation efficacy is compared with that of 5% borated high-dense polyethylene. The results indicate that the HfB2-epoxy composites exhibit promising radiation shielding …
