Mechanical Engineering Commons^™

Effect Of Mnfe2o4 Nanoparticles To Reduce Co And Hc Levels On Vehicle Exhaust Gas Emissions, Poppy Puspitasari, Sukarni Sukarni, Amir Hamzah

Journal of Mechanical Engineering Science and Technology (JMEST)

The air pollution particle emitted from transportation in Indonesia Bay 2015 consist of 70.50% CO; 18.34% HC; 8.89% NOx; 0.88% SOx; 1.33%. These gases are very harmful to humans. To reduce the toxic gas effect, special treatment is needed, one of them is by applying catalyst on exhaust system. MnFe2O4 has the potential to bind the CO and HC elements contained in the exhaust gas. This study aims to investigate the effect of MnFe2O4 addition on catalityc converter towards CO gas and HC emissions of motor vehicles. Therefore, the percentage of exhaust reduction with and without applying MnFe2O4 on varied …

Damage Simulation Of Pre-Forming V-Neck Plates With Variations In Material Type, Time And Temperature Using The Taguchi Method, Avita Ayu Permanasari, Rr. Poppy Puspitasari, Kevin Valiant Cahya, Mahfud Ihsan

Journal of Mechanical Engineering Science and Technology (JMEST)

In metal forming, damage can be caused by several factors: load on the workpiece, initial heating temperature, and temperature due to the friction between the die and the material for pre-forming. The metal forming process can be executed in 2 ways, namely by hot working and cold working. During these two types of mechanical working process, the metal undergoes plastic deformation. In hot working, the required deformation force is relatively low, and changes in mechanical properties are also insignificant. In cold working, a higher force is required, but the strength of the metal will increase significantly. The use of simulation …

Mechanical Properties And Permeability Of Sand Casting Moulds With Eggshells Binder, Maryam Sharifi Jebeli Sharifi Jebeli, Wahyu Kurnianto, Wahono Wahono

Journal of Mechanical Engineering Science and Technology (JMEST)

This research aimed to analyse whether or not eggshell could be a potential addition to sand mould composition as a binding material together with bentonite. Different amounts of eggshell material, i.e. 4%, 7%, 10% and 3%, were added to each sample. This study was a type of pre-experimental design called the one-shot case study. Among all sand moulds under study, sample 3 10% ES in dry conditions had the highest tensile, compressive and shear strengths of 0.09 Kg/cm2, 3.11 Kg/cm2 and 1.13 Kg/cm2, respectively. The results of the permeability test with heat treatment at 110˚C for 60 minutes showed that …

Properties Of Cassava Starch Based Bioplastic Reinforced By Nanoclay, Nanang Eko Wahyuningtiyas, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Synthetic Synthetic plastic is chemical materials which cause severe environmental problems. Incinerating plastic waste leads to release of hazardous gases, which is not good for humans. Bioplastic can help reduce the dependence on fossil fuels and petroleum, that bioplastic can solve the problem of synthetic plastic use. This research aims to define the properties of the cassava starch-based bioplastic reinforced by nanoclay. Methods were experimental with bioplastic component of cassava starch, glycerol as plasticizer and nanoclay as reinforcement. The bioplastic was analyzed using XRD, tensile test, moisture absorption, biodegradability, and compared with another bioplastic. The results show that the addition …

My Catalyst, Gabrielle Gambino Lyon

Celebration of Learning

Over the course of my internship and shadow program with Pepper Lawson Construction and Ziegler Cooper Architects, I was able to explore the various career paths involved in the design, construction, and civil engineering fields. My work on the construction site of a high-rise apartment building located in the heart of Houston, TX allowed me first-hand experience working and learning alongside project engineers, contractors, building developers, and the construction team.

This project was the perfect confluence of my main areas of interest: structural, mechanical, civil, and environmental engineering, as well as architecture. My daily work consisted of on-site walk throughs, …

Reliability Of Solder Joints In Embedded Packages Using Finite Element Methods, Valeri Aisha Yunusa

Dissertations and Theses

Solder joints serve as both mechanical and electrical connections between elements in a package. They are subjected to shear strains generated as a result of the different behaviors of the elements in the package (tension and compression) due to the differences in coefficients of thermal expansion during service conditions.

Some of the causes of solder joint failures are due to the following:

Vibration: small rapid displacements of parts of the assembly. This is not necessarily an issue with electronic components but larger parts like automobiles.

Humidity: the package being exposed to water or ionic species can undergo corrosion if an …

Influence Of Stress Triaxiality On Fracture Ductility For Stereo Lithography, Anjali Sandip, Ravi Kiran Yellavajjala

Mechanical Engineering Posters and Presentations

Stress triaxiality is one of the most important factors that controls fracture ductility. The objective of this study was to investigate the influence of stress triaxiality on fracture ductility for specimens’ printed using stereolithography (SL). Dog bone shape specimens were printed using Formlabs® Form 2 Desktop SLA 3D printer. The specimens were built layer by layer with the help of this 3D printer. Each layer of liquid photopolymer is solidified through a computer-controlled ultraviolet (UV) light source with a laser spot size of 140 𝜇m. A photopolymer resin supplied by the manufacturer which comprised of a proprietary mix of Methacrylated …

Molecular Dynamics Simulation Study On The Possible Factors Affecting Stability Of Ods Steel, M. Mustafa Azeem, Zhongyu Li, Qingyu Wang, Abid Hussian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Oxide-dispersed-strengthened (ODS) steel has excellent mechanical, thermodynamic and radiation resistant properties, which makes it an important candidate material for high-Temperature reactors applications. Radiation stability of oxide is very important to study at the atomic level. In present case molecular dynamics (MD) simulation is used to study stabilities of Y₂O₃ particles in ODS steel as a function of particle sizes. The size dependence is obvious for particle sizes larger than 2.8 nm. Furthermore, the stabilities depend on charges of Y and O atoms.

Design Of Lattice Structures With Graded Density Fabricated By Additive Manufacturing, Wenjin Tao, Yong Liu, Austin T. Sutton, Krishna C. R. Kolan, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice structures fabricated by Additive Manufacturing (AM) processes are promising for many applications, such as lightweight structures and energy absorbers. However, predicting and controlling of their mechanical behaviors is challenging due to the complexity of modeling and the uncertainties exist in the manufacturing process. In this paper, we explore the possibilities enabled by controlling the local densities. A set of lattice structures with different density gradients are designed using an implicit isosurface equation, and they are manufactured by Selective Laser Melting (SLM) process with 304L stainless steel. Finite element analysis and compression test are used to evaluate their mechanical properties. …

Emulating Balance Control Observed In Human Test Subjects With A Neural Network, Wade William Hilts

Dissertations and Theses

Human balance control is a complex feedback system that must be adaptable and robust in an infinitely varying external environment. It is probable that there are many concurrent control loops occurring in the central nervous system that achieve stability for a variety of postural perturbations. Though many engineering models of human balance control have been tested, no models of how these controllers might operate within the nervous system have yet been developed. We have focused on building a model of a proprioceptive feedback loop with simulated neurons. The proprioceptive referenced portion of human balance control has been successfully modeled by …

Pore-Resolving Simulation Of Char Particle Gasification Using Micro-Ct, Greg Hingwah Fong, Scott Jorgensen, Simcha L. Singer

Mechanical Engineering Faculty Research and Publications

Understanding the interaction between transport, reaction and morphology at the scale of individual char particles is important for optimizing solid fuel gasification and combustion processes. However, most particle-scale models treat porous char particles as an effective porous continuum, even though the presence of large, irregular macropores, voids and fractures render such upscaled treatments mathematically invalid, and the models non-predictive. A new modeling framework is therefore proposed to elucidate the impact of morphology on char particle gasification and combustion. A pore-resolving, transient, three-dimensional simulation for gasification of a realistic coal char particle is developed based on X-ray micro-computed tomography (micro-CT). The …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Students Participate in Study Abroad in Germany

Properties Of Torrefied U.S. Waste Blends, Zhou Xu, Stas Zinchik, Shreyas Kolapkar, Ezra Bar Ziv, Ted Hansen, Dennis Conn, Armando G. Mcdonald

Michigan Tech Publications, Part 1

Power generation facilities in the U.S. are looking for a potential renewable fuel that is sustainable, low-cost, complies with environmental regulation standards and is a drop-in fuel in the existing infrastructure. Although torrefied woody biomass, meets most of these requirements, its high cost, due to the use of woody biomass, prevented its commercialization. Industrial waste blends, which are also mostly renewable, are suitable feedstock for torrefaction, and can be an economically viable solution, thus may prolong the life of some of the existing coal power plants in the U.S. This paper focuses on the torrefaction dynamics of paper fiber-plastic waste …

A Study Of Comparing Cad/Cam Simulated Machining Time With Practical Cnc Machining Time And The Influence Of The Parameter Setting In Cnc, Jinming Wan

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the degree of Master of Science by Jinming Wan on July 11, 2018.

The Performance Of Syngas-Fueled Sofcs Predicted By A Reduced Order Model (Rom): Temperature And Fuel Composition Effects, Xinfang Jin, Anthony Ku, Atul Verma, Brandon Ohara, Kevin Huang, Surinder Singh

Faculty Publications

An electrochemical reduced order model (ROM) has been developed in this study to simulate the performance of syngas-fueled anode-supported SOFCs with coupled bulk chemical reactions and multi-species gas diffusion in the electrodes. Experimental V-I curves with syngas fuel were used to validate the model to ensure its high fidelity. The model was used to investigate the effects of fuel composition and temperature on the electrochemical performance of the cell, chemical reaction rate and concentration distributions of gaseous species across the anode. The results show that H₂ electro-oxidation dominates the overall cell performance, and that CO contributes to the performance …

Near-Field Heat Transfer Enabled Nanothermomechanical Memory And Logic Devices, Sidy Ndao, Mahmoud Elzouka

Department of Mechanical and Materials Engineering: Faculty Publications

A thermomechanical memory / logic device is disclosed . In embodiments , the thermomechanical device includes a first thermally controlled terminal ( e . g . , hot terminal ) ; a second thermally controlled terminal ( e . g . , cool terminal / base ) ; a stem or other structure that can be thermally expanded connected to the cool terminal ; and a thermal conductive head coupled to the stem . The head can exchange heat with the hot terminal . The stem and head are between the first thermally controlled terminal and the second thermally controlled …

Design For Maintainability In Developing Communities—A Case Study On The Uros Islands, Thomas Barlow

Undergraduate Honors Theses

Designing products for developing communities has exposed many of the underlying assumptions that engineers from developed nations have during the design process. There has been much written about these underlying assumptions in order to create a better framework for designing for developing communities. One unexplored, yet important area is the universality of common maintainability principles used in developed countries when designing products used in developing communities. Such principles include: simplicity, diagnosability, standardization of parts, modular subassemblies, minimizing assembly and disassembly parts, labeling components, increased life of moving parts, manuals, and simplifying tools needed for repairs [1]–[3]. The purpose of this …

Considerations For Atmospheric Measurements With Small Unmanned Aircraft Systems, Jamey D. Jacob, Phillip B. Chilson, Adam L. Houston, Suzanne Weaver Smith

Mechanical Engineering Faculty Publications

This paper discusses results of the CLOUD-MAP (Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics) project dedicated to developing, fielding, and evaluating integrated small unmanned aircraft systems (sUAS) for enhanced atmospheric physics measurements. The project team includes atmospheric scientists, meteorologists, engineers, computer scientists, geographers, and chemists necessary to evaluate the needs and develop the advanced sensing and imaging, robust autonomous navigation, enhanced data communication, and data management capabilities required to use sUAS in atmospheric physics. Annual integrated evaluation of the systems in coordinated field tests are being used to validate sensor performance while integrated into various sUAS platforms. …

Synthesis And Characterization Of Alpha-Hematite Nanomaterials For Water-Splitting Applications, Hussein Alrobei

USF Tampa Graduate Theses and Dissertations

The recent momentum in energy research has simplified converting solar to electrical energy through photoelectrochemical (PEC) cells. There are numerous benefits to these PEC cells, such as the inexpensive fabrication of thin film, reduction in absorption loss (due to transparent electrolyte), and a substantial increase in the energy conversion efficiency. Alpha-hematite ([U+F061]-Fe2O3) has received considerable attention as a photoanode for water-splitting applications in photoelectrochemical (PEC) devices. The alpha-hematite ([U+F061]-Fe2O3) nanomaterial is attractive due to its bandgap of 2.1eV allowing it to absorb visible light. Other benefits of [U+F061]-Fe2O3 include low cost, chemical stability and availability in nature, and excellent photoelectrochemical …

In Vitro Cytocompatibility Of Antibacterial Levels Of Polymer Nitric Oxide Release, Rana Gbyli, Christina Zito, Kagya Amoako

Mechanical and Industrial Engineering Faculty Publications

Although the antibacterial property of nitric oxide (NO) has been well documented in gram positive and gram negative bacteria cultures, its cytotoxic effects are not completely clear. To limit potential in vivo cytotoxicity, our group recently investigated the effects of a range of NO fluxes on S. epidermidis and S. aureus to determine a minimum effective NO level. In this study, we report the antibacterial function of this minimum NO level also on gram negative Pseudomonas aeruginosa as well as its cytocompatibility effects on lung and kidney cells. Standardized bacterial cultures were treated with NO releasing PDMS substrates followed by …

Texas Sour Orange Juice Used In Scaffolds For Tissue Engineering, Mandana Akia, Nataly Salinas, Cristobal Rodriguez, Robert Gilkerson, Luis A. Materon, Karen Lozano

Mechanical Engineering Faculty Publications

Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S. aureus and E. coli, respectively. The cell studies revealed a suitable environment for cell growth and cell attachment. The outcome …

Intermodel Comparison Between Switch 2.0 And Ge Maps: Evaluating A New Tool For Integrated Modeling Of Electric Vehicles And High-Renewable Power Systems, Florida Solar Energy Center, Matthias Fripp

FSEC Energy Research Center®

This report presents an inter-model comparison between the Switch and GE Energy Consulting, (GE) Multi Area Production Simulation (MAPS) power system models. This work was conducted as part of the project on the "Effect of Electric Vehicles on Power System Expansion and Operation" under a sub award to the Hawaii Natural Energy Institute, University of Hawaii at Manoa (UH), from the Electric Vehicle Transportation Center (EVTC) at the Florida Solar Energy Center, University of Central Florida. The EVTC is a University Transportation Center funded by the Research and Innovative Technology Administration of the US Department of Transportation. The EVTC is …

Fuzzy-Model-Based (Fmb) Control Of A Spacecraft With Fuel Sloshing Dynamics, Lilit Mazmanyan

Engineering Ph.D. Theses

During the upper-stage separation and orbit injection, orbital control, and attitude maneuver, propellant slosh in partially-filled fuel tanks can cause dynamical instability or pointing errors. The spacecraft dynamics combined with propellant sloshing results in a highly nonlinear and coupled dynamic system that requires a complicated control law. This problem has been a long-standing concern for space missions. The purpose of this research is two fold. The first part is to investigate and develop nonlinear Takagi-Sugeno (T-S) fuzzy model-based controllers for a spacecraft with fuel sloshing considering the input constraints on the actuators. It includes i) a fuzzy controller/observer with a …

What Can I Do As A Student To Make A Positive Impact On The Environment?, Tammy Guthrie, Greg Herzig, Kathy Prophet, Cassie Kautzer

Middle School Lesson Plans

Students discover ways they can make a positive impact on the environment.

Prevascularization Of 3d Printed Bone Scaffolds By Bioactive Hydrogels And Cell Co-Culture, Mitchell Kuss, Shaohua Wu, Ying Wang, Jason B. Untrauer, Wenlong Li, Jung Yul Lim, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated …

Structural Transformations In Porous Glasses Under Mechanical Loading. I. Tension, Nikolai V. Priezjev, Maxim A. Makeev

Mechanical and Materials Engineering Faculty Publications

The evolution of porous structure and mechanical properties of binary glasses under tensile loading were examined using molecular dynamics simulations. We consider vitreous systems obtained in the process of phase separation after a rapid isochoric quench of a glass-forming liquid to a temperature below the glass transition. The porous structure in undeformed samples varies from a connected porous network to a random distribution of isolated pores upon increasing average glass density. We find that at small strain, the elastic modulus follows a power-law dependence on the average glass density and the pore size distribution remains nearly the same as in …

Methods For Creating Rigid Foldability In Origami-Inspired Deployable Mechanisms, Alden Daniel Yellowhorse

Theses and Dissertations

Because origami has proved to be a tremendously rich source of inspiration in engineering, interest in solving some of the challenges that affect origami-inspired design has been significant. One such challenge involves ensuring that origami-inspired mechanisms are rigid-foldable or capable of moving without requiring links to bend or distort. Because rigid-foldability is essential in mechanisms that are constructed using rigid materials, access to methods of engineering this characteristic are highly desirable. This research addresses this need by developing methods for the design of origami-inspired mechanisms that are rigid-foldable. Methods for modifying crease patterns to achieve this are described and compared. …

Use Of A Triboelectric Generator For A Tunable Wideband Energy Harvester And A Threshold Shock Sensor, Daniel S. Nelson

Graduate Dissertations and Theses

The prevalence of triboelectricity as a transduction mechanism has increased rapidly in recent years. We will discuss two uses for triboelectric generators. One design is a tunable wideband energy harvester. An axial force and amplitude limiter work together to create an energy harvester that can accommodate various frequency sources and have a large operating bandwidth. The addition of the compressive axial force also softens the system, which allows for higher voltage outputs. A proof of concept of a threshold shock sensor is proposed that incorporates bi-stability along with the triboelectric effect. A clamped-clamped buckled beam will switch stable states when …

Solid Oxide Electrochemical Cells For High Temperature Hydrogen Production: Theory, Fabrication And Characterization, Can Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

In this dissertation, the concept of water splitting using solid oxide photoelectrochemical cells (SOPCs) at high temperature was introduced and experimentally investigated. High temperature photoelectrochemical water splitting physically broadens the selection of potential applicable semiconductor materials and enables more visible sunlight absorption. This newly conceived concept provides a unique pathway for solar hydrogen production, as compared to conventional photoelectrochemical cells (PECs) that use wide band gap semiconductors in aqueous environments. The theoretical framework of SOPC was elaborated, followed by the experimental investigation to search for appropriate high temperature materials. Selected high temperature Schottky and p-n junction diodes, which were expected …

The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Non-equilibrium molecular dynamics simulations are performed to investigate the dynamic behavior of three-dimensional binary glasses prepared via an instantaneous quench across the glass transition. We found that with increasing strain amplitude up to a critical value, the potential energy approaches lower minima in steady state, whereas the amplitude of shear stress oscillations becomes larger. Below the yielding transition, the storage modulus dominates the mechanical response, and the gradual decay of the potential energy over consecutive cycles is accompanied by reduction in size of transient clusters of atoms with large nonaffine displacements. In contrast, above the yield strain, the loss modulus …