Materials Science and Engineering Commons^™

Computational Fluid Dynamics Analysis Of Temperature Distribution In Solar Distillation Panel With Various Flat Plate Materials, Trismawati Trismawati, Hendry Y. Nanlohy, Helen Riupassa, Susi Marianingsih

Journal of Mechanical Engineering Science and Technology (JMEST)

As the world population continues to grow, the demand for clean water is increasing daily, making it a crucial resource to access. However, there are ways to harness abundant resources like solar energy and seawater to produce clean water. The present studies have conducted experimental investigations to convert seawater into freshwater using solar stills, where solar energy is utilized as the primary heat source for evaporation. The temperature distribution inside the solar stills was analyzed using a flat plate made of three different materials: copper, stainless steel, and aluminum. To examine the temperature distribution and performance of the solar stills, …

Comparative Analysis Of The Effect Dual Spark Ignition And Single Spark Ignition On Performance And Exhaust Emissions In Bioethanol-Fueled Engines, Avita Ayu Permanasari, Ahmad Faizal Wahidin, Hasan Ismail, Erwin Komara, Poppy Puspitasari, Gina A. Lorenzo

Journal of Mechanical Engineering Science and Technology (JMEST)

Bioethanol is an alternative fuel that has a high octane value of around 100 to 110, making it difficult to be applied to spark ignition engines directly. So, it is necessary to make adjustments, including increasing combustion efficiency and thermal efficiency of the combustion chamber by increasing the compression ratio and adjusting the ignition system, both in single spark ignition (SSI) and dual spark ignition (DSI) types. The study aims to determine the effect of SSI and DSI applications on engine performance, specific fuel consumption (SFC), and exhaust emissions using 96% and 99% levels of bioethanol fuel. The results showed …

Performance Enhancement Of Dye Sensitized Solar Cell (Dssc) Through Tio2/Rgo Hybrid: Comprehensive Study On Synthesis And Characterization, Rustan Hatib, Khairil Anwar, Ramang Magga, Muh Anjas Astak, Denny Widhiyanuriyawan, Wardoyo Wardoyo

Journal of Mechanical Engineering Science and Technology (JMEST)

The TiO2 film is immersed in a graphite oxide solution, preparing it for thermal reduction, which converts the graphite oxide to reduced graphene oxide (rGO). This process produces rGO hybrid TiO2 photoanodes for dye-sensitized solar cells (DSSC). rGO in the TiO2 structure prevents electron recombination and improves overall efficiency. The main advantage of this method is its ability to prevent loss of rGO during the sintering process, which is a common problem with other methods. The study investigated heating temperatures ranging between 300˚C, 350˚C, 400˚C, 450˚C, and 500˚C to determine optimal conditions. The presence of rGO in the photoanode structure …

Pyrolysis Kinetics Of Spirulina Platensis And Non-Condensable Gas Product Distribution In A Fixed-Bed Reactor, Ahmad Yusril Aminullah, Sukarni Sukarni, Retno Wulandari, Muhammad Shahbaz

Journal of Mechanical Engineering Science and Technology (JMEST)

Energy is a fundamental factor for civilization development and sustainability. However, energy sources are dominated by non-renewable fractions, such as fossil fuels. Renewable biomass is projected to be a future fuel source. Spirulina platensis (SP) has numerous advantages compared to other biomass, and it is considered 3rd generation biomass that does not interfere with food and land usage and has a relatively low main decomposition temperature at 325.7℃. Thermogravimetric analysis (TGA) was conducted to observe SP kinetics parameters, especially activation energy. Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Starink iso-conversional methods reveal that SP has an activation energy of 152.33, 154.56, and …

Crashworthiness And Deformation Pattern Analysis Of Single And Double Wall With Addition Infill Structure, Redyarsa Dharma Bintara, Moch. Agus Choiron, Yahya Zakariya, M. Hasbi Ash Shiddieqy, Fajar Adi Pratama

Journal of Mechanical Engineering Science and Technology (JMEST)

Ship collisions are a phenomenon that often occurs in maritime transportation. One part of the ship that often experiences damage is the ship's wall (hull). This research aims to analyze and compare deformation patterns, stress distribution, and energy absorption in three wall models, single wall, double wall, and double wall, with the addition of infill structures. The infill structure used Polylactic Acid (PLA) polymer material because it provided convenience in the manufacturing process, while the walls of the test model used Aluminum 6063 material. The test model was developed by carrying out the design process using CAD software. Furthermore, a …

Durability Of Thermoplastic Polyurethane Round Belt Joint With Variations In Heating Methods And Cutting Shapes, Achmad Sabilarrosyad Prawiro Kusumo, Anggit Murdani

Journal of Mechanical Engineering Science and Technology (JMEST)

Thermoplastic polyurethane round belts are widely used for conveyors in various industries, particularly in the food and beverage industry, due to their flexible and abrasion-resistant characteristics. These belts are also popular in manufacturing industries because of their ease of joint. However, a common issue arises when the conveyor belt breaks during the production process. This problem can be attributed to the lack of parameters in the belt joining process at companies. Operators do not have a standard parameter for the joining process. When there is an improper joining operation of an operator, the conveyor belt could fail earlier than the …

Heuristic Approach To Comparing The Environmental Impacts Of Carbon Nanotube Production Methods, Ahmad Atif Fikri, Irham Fadlika, Albarrobi Nabila Saeful, Krisna Dwipa Muhdi, Daniel Febrian Pratama, Nasir Garba Bello

Journal of Mechanical Engineering Science and Technology (JMEST)

Carbon Nanotubes (CNTs) production so far has its own advantages and disadvantages. Some methods that can be used in producing CNTs are chemical vapor deposition (CVD), laser ablation, and arc discharge. The three methods have their own requirements, this causes different environmental impacts on each method. Studies into the environmental impact of the CNTs production process found that during thermal pretreatment of the reactant gas, more than 45 by-products were formed, including methane, volatile organic compounds, and polycyclic aromatic hydrocarbons. Calculating the environmental impact of CNTs production method often has challenges in implementation, because each production process has different systems …

Mechanical Properties Of Corner Lap-45 Types Joined Using Friction Stir Welding, Widia Setiawan, Nugroho Santoso, Felixianus Eko Wismo Winarto, Radhian Krisnaputra, Wirawan Widya Mandala, Jibril Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

Solid welding has always been concerned with probe design, pins, and joint strength. Many researchers have conducted studies on joints, such as butt joints, lap joints, and T joints, but the results show low strength. This study analyzes the mechanical properties of a new design of a 90o angle joint joined by friction stir welding. This study connected aluminum 6061 using the friction stir welding method using a rectifying jig and a probe with EMS 45 material. The corner joint designs used corner-lap 45 with feed rate as independent variables in 6, 8, 10, 15, and 30 mm/min and dependent …

Tension–Compression Fatigue Of A Hybrid Polymer-Matrix/Ceramic-Matrix Composite At Elevated Temperature, Marina B. Ruggles-Wrenn, Joshua Schmidt

Faculty Publications

Fully reversed tension–compression fatigue of a hybrid material comprising polymer matrix composite (PMC) co-cured with a ceramic matrix composite (CMC) was investigated. The PMC portion had a polyimide matrix reinforced with 15 plies of carbon fibers woven in an eight-harness satin weave (8HSW). The CMC portion had three plies of a quartz-fiber 8HSW fabric in a zirconia-based ceramic matrix. The hybrid PMC/CMC was developed for use in aerospace thermal protection systems (TPS). Hence, the experimental setup aimed to simulate the TPS service environment—the CMC side was kept at 329 °C, whereas the PMC side was open to laboratory air. Compression …

Data-Driven Viewpoint For Developing Next-Generation Mg-Ion Solid-State Electrolytes, Fang-Ling Yang, Ryuhei Sato, Eric Jian-Feng Cheng, Kazuaki Kisu, Qian Wang, Xue Jia, Shin-Ichi Orimo, Hao Li

Journal of Electrochemistry

Magnesium (Mg) is a promising alternative to lithium (Li) in solid-state batteries due to its abundance and high theoretical volumetric capacity. However, the sluggish Mg-ion conduction in the lattice of solid-state electrolytes (SSEs) is one of the key challenges that hamper the development of Mg-ion solid-state batteries. Though various Mg-ion SSEs have been reported in recent years, key insights are hard to be derived from a single literature report. Besides, the structure-performance relationships of Mg-ion SSEs need to be further unraveled to provide a more precise design guideline for SSEs. In this Viewpoints article, we analyze the structural characteristics of …

Professor Yong Yang, The Editorial Board Member Of Journal Of Electrochemistry, Is Elected As A Fellow Of The Electrochemical Society, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Kai Wu, The Editorial Board Member Of Journal Of Electrochemistry And Chief Scientist Of Catl, Receives The National Science And Technology Progress Award, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Sorbitol-Electrolyte-Additive Based Reversible Zinc Electrochemistry, Qiong Sun, Hai-Hui Du, Tian-Jiang Sun, Dian-Tao Li, Min Cheng, Jing Liang, Hai-Xia Li, Zhan-Liang Tao

Journal of Electrochemistry

The unstable zinc (Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries. Herein, the hydroxy-rich sorbitol was used as an additive to reshape the solvation structure and modulate the interface chemistry. The strong interactions among sorbitol and both water molecules and Zn electrode can reduce the free water activity, optimize the solvation shell of water and Zn²⁺ ions, and regulate the formation of local water (H₂O)-poor environment on the surface of Zn electrode, which effectively inhibit the decomposition of water molecules, and thus, achieve the thermodynamically stable …

Series Reports From Professor Wei’S Group Of Chongqing University: Advancements In Electrochemical Energy Conversions (1/4): Report 1: High-Performance Oxygen Reduction Catalysts For Fuel Cells, Fa-Dong Chen, Zhuo-Yang Xie, Meng-Ting Li, Si-Guo Chen, Wei Ding, Li Li, Jing Li, Zi-Dong Wei

Journal of Electrochemistry

Two major challenges, high cost and short lifespan, have been hindering the commercialization process of low-temperature fuel cells. Professor Wei’s group has been focusing on decreasing cathode Pt loadings without losses of activity and durability, and their research advances in this area over the past three decades are briefly reviewed herein. Regarding the Pt-based catalysts and the low Pt usage, they have firstly tried to clarify the degradation mechanism of Pt/C catalysts, and then demonstrated that the activity and stability could be improved by three strategies: regulating the nanostructures of the active sites, enhancing the effects of support materials, and …

First Announcement Of 76th Annual Meeting Of The International Society Of Electrochemistry, International Society Of Electrochemistry (Ise)

Journal of Electrochemistry

No abstract provided.

Surface Structures And Properties Of High-Voltage Licoo2: Reviews And Prospects, Jian-Jun Fang, Yu-Hao Du, Zi-Jian Li, Wen-Guang Fan, Heng-Yu Ren, Hao-Cong Yi, Qing-He Zhao, Feng Pan

Journal of Electrochemistry

Nowadays, the development of high-voltage LiCoO₂ (lithium cobalt oxide, LCO) cathodes has attracted the widespread attention from both the academic and industry fields. Among the multiple concerns, researches on the surface issues would provide the most effective performance optimization pathway for the synthesis of high-voltage LCO. In this work, the issues of high-voltage LCO, including the phase transitions and crack formation, the oxygen redox related issues and side reactions, as well as the surface structure degradation, have been systematically reviewed. Then, we further clarify the surface modulations, and the interplay between the surface modulation and electrolyte tuning. Finally, we …

Molybdenum Disulfide And Carbon Nanotubes Composite Electrode For Electrochemical Conversion Of Salinity Gradient Energy, Jia-Jun Li, Wei-Bin Zhang, Xin-Yu Liu, Jing-Lei Yang, Yi Yin, Ze-Qin Yang, Xue-Jing Ma

Journal of Electrochemistry

The ocean accounts for 97% of the total water resources on earth, covering over 70% of the map's surface area. With the continuous consumption of non-renewable energy sources such as fossil fuels and the rapid development of renewable energy, humans are increasingly paying attention to the utilization of ocean resources. Ocean energy includes tidal energy, wave energy, temperature difference energy, and salinity gradient energy. Salinity gradient energy is the energy generated by the interaction of seawater and fresh water, which is the ocean energy existing in the form of chemical energy. This energy is mostly generated in estuaries. The osmotic …

A First Step Towards Understanding Thermomechanical Behavior Of The Nb-Cr System Through Interatomic Potential Development And Molecular Dynamics Simulations, Lucas A. Heaton, Adib J. Samin

Faculty Publications

Utilizing a preliminary interatomic potential, this work represents an initial exploration into the thermomechanical behavior of NbCr solid solutions. Specifically, it examines the effect of different amounts of Cr solute, for which information in the literature is limited. The employed interatomic potential was developed according to the embedded atom model (EAM), and was trained on data derived from density functional theory calculations. While the potential demonstrated reasonable accuracy and predictive power when tested, various results highlight deficiencies and encourage further development and training. Mechanical strength, heat capacities, thermal expansion coefficients, and thermal conductivities were found to decrease with Cr content. …

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Using Dft On Ultrasound Measurements To Determine Patient-Specific Blood Flow Boundary Conditions For Computational Hemodynamics Of Intracranial Aneurysms, Hang Yi, Zifeng Yang, Luke Bramlage, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

Boundary conditions (BCs) is one pivotal factor influencing the accuracy of hemodynamic predictions on intracranial aneurysms (IAs) using computational fluid dynamics (CFD) modeling. Unfortunately, a standard procedure to secure accurate BCs for hemodynamic modeling does not exist. To bridge such a knowledge gap, two representative patient-specific IA models (Case-I and Case-II) were reconstructed and their blood flow velocity waveforms in the internal carotid artery (ICA) were measured by ultrasonic techniques and modeled by discrete Fourier transform (DFT). Then, numerical investigations were conducted to explore the appropriate number of samples (N) for DFT modeling to secure the accurate BC by comparing …

A Computational Investigation Of Wood Selection For Acoustic Guitar, Jonah Osterhus

Senior Honors Theses

The acoustic guitar is a stringed instrument, often made of wood, that transduces vibrational energy of steel strings into coupled vibrations of the wood and acoustic pressure waves in the air. Variations in wood selection and instrument geometry have been shown to affect the timbre of the acoustic guitar. Computational methods were utilized to investigate the impact of material properties on acoustic performance. Sitka spruce was deemed the most suitable wood for guitar soundboards due to its acoustic characteristics, strength, and uniform aesthetic. Mahogany was deemed to be the best wood for the back and sides of the guitar body …

Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao

Graduate Theses and Dissertations (2019 - present)

Biochar, a naturally occurring and renewable carbon material, becomes porous through activation. Activated biochar is an ideal candidate for use as an adsorbent. The objective of this study is to investigate whether activated biochar derived from Colorado soft pine serves as a better adsorbent and demonstrates enhanced adsorption capabilities after undergoing secondary physical activation at various activation times. The effect of secondary action time on physical adsorption properties drawn from the analysis of isotherm plots, surface areas and pore size patterns were examined by using a physisorption analyzer. Chemical structures were identified using both ultimate and proximate analyses, while porosity …

Micro-Mechanical Characterization Of Uhpc Stiffness Mechanisms: Towards A Better Understanding Of Concrete Elastic Modulus, Charissa N. Puttbach

Graduate Theses and Dissertations

Current design code equations for estimating the elastic modulus of specialty concretes like ultra-high performance concrete are not all suitable. Developing empirical curves from exhaustive experimental testing is challenging for concretes that may have high levels of cement replacement with mineral admixtures and fibers at varying volume contents. As such, an alternative approach is taken that seeks to understand the constituent microscale stiffness mechanisms and relate the results to the macroscale. Micropillars are fabricated on several cement paste phases using a focused ion beam. A modified pico-indenter is used to determine the linear and non-linear behavior under micro-compression loading. Micropillar …

Boron-Doped Diamond As A Resilient Electrode Material In Molten Salts, Hannah Katherine Patenaude

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molten salt chemistry has a range of applications within nuclear technology, including for the Molten Salt Reactors (MSRs) and pyroprocessing to recover valuable actinides for energy and national security needs. However, the high-temperature, corrosive nature of molten salts makes them particularly challenging to deploy on an industrial scale and study in benchtop measurements. Material accountability and corrosion monitoring of MSR fuels are essential components to the successful deployment of MSRs, and electroanalytical techniques like cyclic voltammetry (CV) and spectroelectrochemistry (SEC) can provide a wealth of information to describe salt systems in situ. To perform such measurements, it is imperative to …

Numerical Simulation Of Laser Induced Elastic Waves In Response To Short And Ultrashort Laser Pulses., Alireza Zarei

All Dissertations

In an era of intensified market competition, the demand for cost-effective, high-quality, high-performance, and reliable products continues to rise. Meeting this demand necessitates the mass production of premium products through the integration of cutting-edge technologies and advanced materials while ensuring their integrity and safety. In this context, Nondestructive Testing (NDT) techniques emerge as indispensable tools for guaranteeing the integrity, reliability, and safety of products across diverse industries.

Various NDT techniques, including ultrasonic testing, computed tomography, thermography, and acoustic emissions, have long served as cornerstones for inspecting materials and structures. Among these, ultrasonic testing stands out as the most prevalent method, …

Improved Ballistic Impact Resistance Of Nanofibrillar Cellulose Films With Discontinuous Fibrous Bouligand Architecture, Colby Caviness

All Theses

Natural protective materials offer unparalleled solutions for impact-resistant material designs that are simultaneously lightweight, strong, and tough. Particularly, the dactyl club of mantis shrimp features chitin nanofibrils organized in a Bouligand structure, which has been shown to effectively dissipate high-impact energy during powerful strikes. The mollusk shells also achieve excellent mechanical strength, toughness, and impact resistance with a staggered, layer-by-layer structure. Previous studies have shown that hybrid designs, by combining different bioinspired microstructures, can lead to enhanced mechanical strength and energy dissipation capabilities. Nevertheless, it remains unknown whether combining Bouligand and staggered structures in nanofibrillar cellulose (NFC) films, forming a …

A Manufacturing-To-Response Pathway For Manufacturing Optimization Of Carbon Fiber Reinforced Polymer Composite Structures, Madhura Limaye

All Dissertations

Over the past decade, there has been an increased adoption of thermoplastic and thermoset based continuous carbon fiber reinforced polymer (CFRP) composites for structural applications in several industries. Among the different manufacturing methods, thermoforming process for thermoplastic based continuous CFRP’s offer a major advantage in reducing cycle times for large scale productions. Similarly, out-of-autoclave curing process for thermoset based continuous CFRP’s using heated tooling enables production of large composite structures. However, these manufacturing processes can have a significant impact on the structural performance of parts by inducing undesirable effects. These effects include inhomogeneous fiber orientations, thickness variations, and residual stresses …

Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation, Jun-Bo Ma, Sheng Lin, Zhiqun Lin, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Ammonia (NH₃) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H₂ and N₂ as reactants in the presence of iron-based catalysts at high-temperature (400–600 ^oC) and extremely highpressure (20–40 MPa) conditions. However, its efficiency is limited to 10% to 15%. At the same time, a large amount of energy is consumed, and CO₂ emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. …

The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin

Faculty Publications

Analyzing plastic flow in refractory alloys is relevant to many different commercial and technological applications. In this study, screw dislocation statics and dynamics were studied for various compositions of the body-centered cubic binary alloy tungsten–molybdenum (W–Mo). The core structure did not appear to change for different alloy compositions, consistent with the literature. The pure tungsten and pure molybdenum samples had the lowest plastic flow, while the highest dislocation velocities were observed for equiatomic, W_0.5Mo_0.5 alloys. In general, dislocation velocities were found to largely align with a well-established dislocation mobility phenomenological model supporting two discrete dislocation mobility regimes, …

Automated Workflow For Redox Potentials And Acidity Constants Calculations From Machine Learning Molecular Dynamics, Feng Wang, Jun Cheng

Journal of Electrochemistry

Redox potentials and acidity constants are key properties for evaluating the performance of energy materials. To achieve computational design of new generation of energy materials with higher performances, computing redox potentials and acidity constants with computational chemistry have attracted lots of attention. However, many works are done by using implicit solvation models, which is difficult to be applied to complex solvation environments due to hard parameterization. Recently, ab initio molecular dynamics (AIMD) has been applied to investigate real electrolytes with complex solvation. Furthermore, AIMD based free energy calculation methods have been established to calculate these physical chemical properties accurately. However, …