Engineering Commons^™

Mechanical Interfacial Locking And Multiscale Modeling Of Reinforced Thermoplastic Composites For Structural Applications, Anmol Kothari

All Dissertations

The ever-growing pressure of reducing the adverse impact of transportation systems on environment has pushed industries towards fuel-efficient and sustainable solutions. While several approaches have been used to improve fuel efficiency, the light-weighting of structural components has proven broadly effective. In this regard, reinforced thermoplastic composites (RTPC), owing to their high recyclability, higher impact strength and fast cycle times, have become competitive candidates at an industrial scale. However, to implement RTPC toward large scale structural applications several challenges pertaining to material design and manufacturing effects need to be addressed. To this end, a computational study is carried out to address …

Investigation And Characterization Of New Optically Stimulated Luminescence (Osl) Dosimetric Materials, Linyu Pan

All Dissertations

Optically stimulated luminescence (OSL) dosimeters have attracted increasing attention due to advantages over TL dosimeters, including no thermal quenching and higher sensitivity. Nevertheless, currently, there are only two commercially available OSL dosimeters, BeO and Al₂O₃:C. An OSL dosimeter requires low effective atomic number (Z_eff < 16), at least one type of recombination center and one type of trap, and UV~blue emission. In this dissertation, motivated by the search of new OSL dosimetric materials, a systematic investigation of alumina (Z_eff = 11.3) and magnesium aluminate spinel (Z_eff = 11.2) based materials was performed in terms of the engineering of the recombination centers and electronic traps. Microstructural characterization was executed by means of X-ray diffraction (XRD) and Raman spectroscopy. Luminescence was characterized under X-ray excitation (radioluminescence; RL) at ambient and …

Bioabsorbable Metal Zinc Differentially Affects Mitochondria In Vascular Endothelial And Smooth Muscle Cells, Olivia R. M. Bagshaw, Fereshteh Moradi, Christopher S. Moffatt, Hillary A. Hettwer, Ping Liang, Jeremy Goldman, Jaroslaw Drelich, Jeffrey A. Stuart

Michigan Tech Publications, Part 1

Zinc is an essential trace element having various structural, catalytic and regulatory interactions with an estimated 3000 proteins. Zinc has drawn recent attention for its use, both as pure metal and alloyed, in arterial stents due to its biodegradability, biocompatibility, and low corrosion rates. Previous studies have demonstrated that zinc metal implants prevent the development of neointimal hyperplasia, which is a common cause of restenosis following coronary intervention. This suppression appears to be smooth muscle cell-specific, as reendothelization of the neointima is not inhibited. To better understand the basis of zinc's differential effects on rat aortic smooth muscle (RASMC) versus …

Hybrid Two Dimensional Quantum Devices, Joshua Patrick Thompson

Graduate Theses and Dissertations

This thesis describes measurements on hybrid material systems involving two dimensional (2D) materials and phenomena along with the development of a small, hermetically sealed cell. The hermetic cell is designed to assist with analyzing sensitive 2D materials outside of an inert environment. When working with van der Waals materials that are especially sensitive to oxygen or water, it can be difficult to identify usable thin flakes without exposing them to air. To help preserve materials for analysis in air, a capsule was designed that isolates the material in an inert environment. Although the capsule is hermetically sealed, the encapsulated material …

Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu

Graduate Theses and Dissertations

Since the early 2000s heavy-metal-free quantum dots (QDs) such as CuInS2/ZnS have attempted to replace CdSe, their heavy-metal-containing counterparts. CuInS2/ZnS is synthesized in a two-step process that involves the fabrication of CuInS2 (CIS) nanocrystals (NCs) followed by the addition of zinc precursors. Instead of the usual core/shell architecture often exhibited by binary QDs, coating CIS QDs results in alloyed and/or partially alloyed cation-exchange (CATEX) QDs. The effect that zinc has on the properties of CIS NCs was studied by incorporating zinc during the first step of the synthesis. Different In:Cu:Zn ratios were employed in this study, maintaining a constant 4:1 …

Life Cycle Assessment Of Pasture-Based Agrivoltaic Systems: Emissions And Energy Use Of Integrated Rabbit Production, Alexis Pascaris, Robert Handler, Chelsea Schelly, Joshua Pearce

Michigan Tech Publications, Part 1

Agrivoltaic systems, which deliberately maximize the utility of a single parcel of land for both solar photovoltaic (PV) electricity production and agriculture, have been demonstrated as a viable technology that can ameliorate competing land uses and meet growing energy and food demands efficiently. The goal of this study is to assess the environmental impacts of a novel pasture-based agrivoltaic concept: co-farming rabbits and solar PV. A life cycle assessment (LCA) quantified the impacts of 1) the integrated agrivoltaic concept in comparison to conventional practices including 2) separate rabbit farming and PV production and 3) separate rabbit farming and conventional electricity …

Energy Efficient Configuration Or Perforated Solar Screens For Residential Desert Buildings, Rasha Arafa

Archived Theses and Dissertations

In hot arid desert environments, the solar radiation passing through windows increases the cooling loads and energy consumption of buildings. Shading of windows can reduce these loads. External perforated wooden solar screens were traditionally used for windowsâ shading. However, there is a lack in understanding their performance in a quantitative manner and unavailability of scientific means that could be used for developing new efficient designs that suit the harsh desert conditions. This thesis investigates the impact of changing screen configurations such as perforation percentage, depth, perforation openings aspect ratio and reflectivity on the energy loads, hence defining the most efficient …

Dechlorination Apparatus For Treating Chloride Salt Wastes: System Evaluation And Scale-Up, Brian J. Riley, Saehwa Chong, Charmayne E. Lonergan

Materials Science and Engineering Faculty Research & Creative Works

This paper describes an apparatus used to remove chlorine from chloride salt-based nuclear wastes from electrochemical reprocessing and/or chloride-based molten salt reactors (MSRs) through dechlorination by reacting the salts with ammonium dihydrogen phosphate (NH₄H₂PO₄ or ADP) at temperatures up to 600 °C to produce NH₄Cl as a byproduct. The benefits of removing the Cl from these salts include ³⁷Cl recovery from Cl-based MSR salts, formation of UCl₃ from the NH₄Cl, as well as removal of Cl from the salts and conversion of the salt cations to oxides to allow …

Comparative Studies On Combustion Characteristics Of Blended Crude Jatropha Oil With Magnetic Liquid Catalyst And Dex Under Normal Gravity Condition, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

A comparative study on the combustion characteristics of a single droplet fueled by DEX, crude jatropha oil (CJO), and a mixture of CJO with a magnetic liquid catalyst of rhodium trisulfate has been carried out under normal gravity conditions. The high viscosity of crude jatropha oil makes it difficult to burn under normal conditions (room temperature and atmospheric pressure), therefore the addition of a magnetic liquid catalyst rhodium trisulfate is needed to improve the properties of crude jatropha oil. As a catalyst, rhodium trisulfate has the potential to improve combustion performance while improving the physical properties of crude jatropha oil …

Study Of Methanol And Ethanol Absorption On Vacuum Temperature Of Adsorption Cooling Machine Adsorption Cycle, Jhon Sufriadi Purba, Jandri Fan Ht. Saragi

Journal of Mechanical Engineering Science and Technology (JMEST)

Cooling machines are currently being used more and more in accordance with technological advances and increasing living standards. Common uses are for preserving food, air conditioning, cooling beverages, for making ice cubes, and others. The need for cooling systems in remote areas for various needs such as preservation or storage of food ingredients is felt to be increasing, while the existing conventional cooling systems cannot necessarily be used because not all remote areas have electricity networks, so a simple adsorption cooling system is an alternative for solving problems. A cooling system needs in remote areas like this. The purpose of …

Spray Characteristics At Preheating Temperatur Of Diesel-Biodiesel-Gasoline Fuel Blend, Moch. Miftahul Arifin, Nasrul Ilminnafik, Agus Triono

Journal of Mechanical Engineering Science and Technology (JMEST)

Technological developments in diesel engines require improvements to the fuel injection system to meet the criteria for economical, high-power and efficient combustion and meet environmental regulatory standards. One method that has a lot of interest is changing the characteristics of the fuel, with the aim of producing optimal combustion. Spray characteristics have a big role in determining the quality of combustion in diesel engines. A good spray can improve the quality of fuel atomization and the homogeneity of the air-fuel mixture in the combustion chamber so that it can produce good engine performance and low emissions. This study aims to …

Design Of Shielded Metal Arc Welding Parameters For Optimum Tensile Strength Using Taguchi Method, Moh. Dedy Setiawan, Yanuar Rohmat A. P. Pradana, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

Shielded Metal Arc Welding (SMAW), an arc welding process, is widely used in applications. In practice, SMAW is widely applied to the welding process on hollow square pipe. Performance expected from this welding is the tensile strength of weld joint. The tensile strength is influenced by parameters process which have possibility for an optimization process to become ‘robust’. Robust is a design which less sensitive to the effect of uncertain quantities or noise factors. Taguchi method is the most efficient optimization method which accommodates the noise factors effect and requires less experiment. This study is focusing on optimizing the welding …

Effect Of Variations In Pyrolysis Reactor With Glass Wool Equipped And Without Glass Wool On The Weight Of The Oil Produced, I Gusti Ngurah Nitya Santhiarsa

Journal of Mechanical Engineering Science and Technology (JMEST)

Currently, plastic waste is a very serious threat because plastic waste pollution can harm all living things around and also harm the environment. The increasing volume of plastic waste is due to the lack of processing technology, so that the volume of plastic waste is increasing day by day. Plastic is a material that is difficult to decompose because it is non-biodegradable. One application of plastic waste processing technology offered in this study is to use the pyrolysis principle. Pyrolysis is a method of converting plastic into fuel oil through a thermal decomposition process without the use of oxygen. The …

Characterization Of Bacterial Nanocellulose - Graphite Nanoplatelets Composite Films, Bili Darnanto Susilo, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Bacterial cellulose (BC) was synthesized from pineapple peel extract media with addition of fermentation agent bacteria Acetobacter xylinum. BC was disintegrated from the pellicle into bacterial nanocellulose (BNC) by using a high-pressure homogenizer (hph) machine, which has a three-dimensional woven nanofibrous network. The synthesis of composite films started when BNC, graphite nanoplatelets, and cetyltrimethylammonium bromide (CTAB) were homogenized using an ultrasonic homogenizer then baked on a glass mold at a temperature of 80 degrees Celcius for 14h. A scanning electron microscope (SEM) was used to analyze its morphology. X-Ray diffraction spectra were used to analyze the composite films structure. The …

Implementation Of Internet Of Things (Iot) In A Plastic Blow Moulding Machine And Its Performance Measurement, Muhammad F. Faqih, Mahros Darsin, Aris Z. Muttaqin, Danang Yudistiro

Journal of Mechanical Engineering Science and Technology (JMEST)

Efficiency and effectiveness are indispensable things in the production process. Accurate use of existing resources and the shorter cycle time of production are of particular concern to optimize the production process. This research aims to implement automation to a conventional blow molding. An advanced attempt was carried out to use the Internet of Things (IoT) to increase its efficiency while maintaining the quality of the products. The use of the nodeMCU microcontroller and the blynk application allows the operator to operate the machine without having to come into or having direct contact with the machine. The performance of automation and …

Wear Property Of Machined Ultra High Molecular Weight Polyethylene (Uhmwpe) Acetabular Liner Product With Cnc Milling, W D. Lestari, A T. Danaryanto, A Nugroho, R Ismail, J Jamari, A P. Bayuseno

Journal of Mechanical Engineering Science and Technology (JMEST)

UHMWPE has been used as a cushion in artificial hip joint for the last decades. The reliability of the components of a hip joint implant can be achieved by understanding their wear behavior. This study observed the tribological performance of the UHMWPE acetabular liner manufactured with a CNC milling machine on the femoral head made of SS 316L. Materials commonly used for tribo pairs in hip joint replacement. The wear tests were performed on a hip joint simulator in dry condition. The wear test is carried out by applying a constant load of 800N. Before and after the wear test, …

Interferometric Lithography- An Approach To Large Area And Cost Effective Nanopatterning, Vineeth Sasidharan

Optical Science and Engineering ETDs

In this dissertation interferometric lithography is approached in two different ways to address two important constraints of nanopatterning. One approach solves the problem of scaling up interferometric lithography to wafer scale (4 inch or larger) area. Through the second approach we have developed a nanopatterning technique based on interferometric lithography by using an inexpensive (~$100) diode laser as source, making interferometric lithography a very cost-effective technique.

Wafer-scale large-area nanopatterning was developed using an amplitude grating mask as a grating beam splitter along with spatial averaging of laser intensity by wobbling. The longitudinal and transverse coherence issues both are eased by …

Stochastic Lightning Damage Prediction Of Carbon/Epoxy Composites With Material Uncertainties, S.Z.H. Shah, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

This study presents a novel stochastic modeling framework predicting lightning thermal damage in carbon/epoxy composites. The stochastic lightning damage model (SLDM) was developed with random distributions of composite’s electrical conductivity and void. The Box-Muller transformation was applied to generate random in-plane and through-thickness electrical conductivities with Gaussian distributions. The SLDM suggested that the predicted lightning thermal damage to carbon/epoxy composites increased slightly with the use of stochastic electrical conductivity, but the presence of voids did not significantly affect the damage development. The predicted size and shape of lightning thermal damage agreed fairly well with experimental results. In addition, the proposed …

Growth, Characterization, And Mechanical Testing Of Diamond-Like Carbon Films, Tailei Qi

LSU Master's Theses

The high residual stresses within diamond-like carbon (DLC) films limit its thickness and make the film tend to delaminate from the substrate and be defective on the surface. To address this problem, a new plasma enhanced chemical vapor deposition system (PECVD) was set up to investigate the effects of different film growth parameters on the DLC films, such as chromium doping, gas fluxes, depositing pressures, bias voltages, and depositing times. After the film growth parameters were optimized, this condition was transferred from silicon wafer to SS316 steel plate to deposition of DLC films with some adjustments. Scanning electron microscopy (SEM) …

Surface Engineering Of Materials For Optical And Biomedical Applications, Syed Mohammad Abid Hasan

LSU Doctoral Dissertations

The mechanisms of various optical and medical applications depend on the characteristics of the surface of the material which is being used to detect the molecule of interest. In this work, we focused on some specific areas of surface engineering that play a vital role to improve the performance of some material characteristics. Firstly, we focused on the wettability of graphene, which is important for surface modification and thermal/fluidic properties. The level of transparency to van der Waals forces, chemical bonds, and electrostatic interactions between atoms and molecules on two sides of graphene single layer is not well understood. Our …

Spatial And Temporal Analysis Of Sodium-Ion Batteries, Dewen Hou, Eric Gabriel, Joshua A. Russell, Kincaid Graff, Hui Xiong

Materials Science and Engineering Faculty Publications and Presentations

As a promising alternative to the market-leading lithium-ion batteries, low-cost sodium-ion batteries (SIBs) are attractive for applications such as large-scale electrical energy storage systems. The energy density, cycling life, and rate performance of SIBs are fundamentally dependent on dynamic physiochemical reactions, structural change, and morphological evolution. Therefore, it is essential to holistically understand SIBs reaction processes, degradation mechanisms, and thermal/mechanical behaviors in complex working environments. The recent developments of advanced in situ and operando characterization enable the establishment of the structure–processing–property–performance relationship in SIBs under operating conditions. This Review summarizes significant recent progress in SIBs exploiting in situ and operando …

Degradation Issues And Stabilization Strategies Of Protonic Ceramic Electrolysis Cells For Steam Electrolysis, Hanrui Su, Yun Hang Hu

Michigan Tech Publications, Part 1

Protonic ceramic electrolysis cells (PCECs) are attractive electrochemical de-vices for converting electrical energy to chemicals due to their high conversion efficiency, favorable thermodynamics, fast kinetics, and inexpensive materials. Compared with conventional oxygen ion- conducting solid oxide electrolysis cells, PCECs operate at a lower operating temperature and a favorable operation mode, thus expecting high durability. However, the degradation of PCECs is still significant, hampering their development. In this review, the typical degradations of PCECs are summarized, with emphasis on the chemical stability of the electrolytes and the air electrode materials. Moreover, the degradation mechanism and influencing factors are assessed deeply. Finally, …

Explorations And Developments In Multifunctionality, 3d Printing, And Accelerated Aging For Thermoplastics And Thermosets, Zachary Brounstein

Nanoscience and Microsystems ETDs

If the world is to progress through the fourth industrial revolution, rapid advances in materials science must complement new technological feats in manufacturing, computation and device functionality, and a broader understanding of how materials behave as they age and degrade. To this effect, much effort has been directed towards polymeric materials to address and solve many problems in this new era. This includes developing polymer composites that incorporate fillers to imbue multifunctionality, fabricating novel formulations for additive manufacturing, and conducting aging studies to assess the performance of these materials over long time spans. Building and expanding on the latest research …

The Photophysical Studies Of Transition Metal Polyimines Encapsulated In Metal Organic Frameworks (Mof’S), Jacob M. Mayers

USF Tampa Graduate Theses and Dissertations

Light harvesting systems provide a platform that converts solar energy into other forms of energy. One of the most common examples of photon capturing and conversion into chemical energy is observed in photosynthetic organisms in both Eurkaroyic and Prokaryotic domains. Nature provides a model for successful light harvesting platforms which includes the compartmentalization of antenna complexes that contain separated donor and acceptor pairs that participate in efficient electron transfer processes. In order to mimic such systems, crystalline porous materials that exhibits regular cavities and pore dimensions provides an excellent starting place. Metal organic frameworks (MOFs) are a class of porous …

Crystal Structure Prediction Of Materials At Extreme Conditions, Ashley S. Williams

USF Tampa Graduate Theses and Dissertations

The prediction of the structure of a crystal given only the constituent elements is one of the greatest challenges in both materials science and computational science alike. If one were to try to predict a novel crystal by brute force, meaning by arranging the atoms in every possible position of the unit cell and optimizing the geometry to find the energy minima of the potential energy surface, the amount of computer resources required to complete the calculation on the timescale of a few years would vastly exceed the currently installed computational capacity of the entire world. Fortunately, several methods have …

Nanocrystals Impregnated Porous Article And Method Of Making And Using Same, Michael D. Sherburne

AFIT Patents

The present invention relates to devices for detecting radiation by the excitation of colloidal nanocrystals within a porous article and methods of using same. The aforementioned device is inexpensive and can be fabricated quickly in order to detect radiation. Due to the use of colloidal nanocrystals which have been known to have a decay constant of under 100 ps when energetic electrons produced by an incident x-ray excite the nanocrystals, this device can be used in fast radiation detection of x-rays.

Improvised Centrifugal Spinning For The Production Of Polystyrene Microfibers From Waste Expanded Polystyrene Foam And Its Potential Application For Oil Adsorption, Marco Laurence M. Budlayan, Jonathan N. Patricio, Jeanne Phyre B. Lagare, Susan D. Arco, Arnold C. Alguno, Antonio M. Basilio, Felmer S. Latayada, Rey Y. Capangpangan

Physics Faculty Publications

A straightforward approach to recycle waste expanded polystyrene (EPS) foam to produce polystyrene (PS) microfibers using the improvised centrifugal spinning technique is demonstrated in this work. A typical benchtop centrifuge was improvised and used as a centrifugal spinning device. The obtained PS microfibers were characterized for their potential application for oil adsorption. Fourier transform infrared spectroscopy results revealed similarity on the transmission bands of EPS foam and PS microfibers suggesting the preservation of the EPS foam’s chemical composition after the centrifugal spinning process. Scanning electron microscopy displayed well-defined fibers with an average diameter of 3.14 ± 0.59 μm. At the …

Optically Active Selenium Vacancies In Baga4Se7 Crystals, Brian C. Holloway, Timothy D. Gustafson, Christopher A. Lenyk, Nancy C. Giles, Kevin T. Zawilski, Peter G. Schunemann, Kent L. Averett, Larry E. Halliburton

Faculty Publications

Barium gallium selenide (BaGa₄Se₇) is a recently developed nonlinear optical material with a transmission window extending from 470 nm to 17 μm. A primary application of these crystals is the production of tunable mid-infrared laser beams via optical parametric oscillation. Unintentional point defects, such as selenium vacancies, cation vacancies (barium and/or gallium), and trace amounts of transition-metal ions, are present in BaGa₄Se₇ crystals and may adversely affect device performance. Electron paramagnetic resonance (EPR) and optical absorption are used to identify and characterize these defects. Five distinct EPR spectra, each representing an electron …

Spin Coupling In Magnetic Core - Shell Nanoparticles, Corisa Kons

USF Tampa Graduate Theses and Dissertations

Magnetic nanoparticles (NPs) have garnered much interest due to the unique properties that emergewhen compared to their bulk counterparts. In particular, core-shell (CS) NPs offer the ability to tailor the magnetic properties of the system through careful selection of core and shell constituent materials. In this work, the magnetic ordering of CS NPs with contrast in core/shell features (moment, anisotropy, coercivity, etc.) have been investigated using a combination of X-ray magnetic circular dichroism spectroscopy (XMCD) and polarized small angle neutron scattering (SANS). First, temperature-dependent analyses of XMCD and SANS studies were carried out for CS NPs featuring a core composed …

Entrepreneurially Minded Learning In The Unit Operations Laboratory Through Community Engagement In A Blended Teaching Environment, Erick S. Vasquez, Kelly Bohrer, Abraham Noe-Hays, Arthur Davis, Matthew Dewitt, Michael J. Elsass

Chemical and Materials Engineering Faculty Publications

Online and blended learning opportunities in Chemical Engineering curriculum emerged due to COVID-19. After eight weeks of in-person Unit Operations Laboratory sessions, a remote-learning open-ended final project was assigned to student teams. The assignment involved aspects related to entrepreneurial-minded learning (EML) and community-based learning (CBL). Results show correlations between self-directed learning and the EML framework. Continuous support and involvement of a community partner correlate to students' m