Materials Science and Engineering Commons^™

Synthesis Of Libob Fine Powder To Increase Solubility, Etty Marti Wigayati, Titik Lestariningsih, Christin Rina Ratri, Ibrahim Purawiardi, Bambang Prihandoko

Makara Journal of Technology

Lithium bis (oxalate) borate or LiBOB compound has captured interest of researchers, because it is potentially viable to be used as electrolyte salt in lithium-ion battery system. This compound is easy to synthesize and considered to be more environmentally friendly compared to conventional electrolyte salt because LiBOB does not contain halogen element. This research focused on the synthesis of LiBOB fine powder, which main purpose is improving LiBOB salt solubility in liquid electrolyte solution. This will aid the ion transfer between electrodes which in turn will increase the electrolyte performance. Solid state reaction was employed in this experiment. Synthesis of …

Influence Of Polyethylene Glycol (Peg) In Cmc-Nh4br Based Polymer Electrolytes: Conductivity And Electrical Study, Nur Khalidah Zainuddin, Ahmad Salihin Samsudin

Makara Journal of Technology

The present work was carried with new type and promising polymer electrolytes system by development of carboxyl methylcellulose (CMC) doped NH4Br and plasticized with polyethylene glycol (PEG). The sample was successfully prepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity and thermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedance spectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1 at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable …

Purification Simulation With Vapor Permeation And Distillation-Adsorption In Bioethanol Plant, Misri Gozan, Mia Sari Setiawan, Kenny Lischer

Makara Journal of Technology

High purity of Bioethanol is required in biofuel mixing with gasoline (EXX). In bioethanol production line, the azeotropic property of ethanol-water becomes the barrier for purification process. This study examined two bioethanol separation processes by support of simulation tools, Superpro Designer 9.0 software. Ethanol purity and a low costeconomical process were the major considerations. Purification method of vapor permeation membrane technology was compared with distillation-adsorption method. Data from previous lab experiments and some literatures were used. The results showed that distillation-adsorption method is more economical compared to vapor permeation technology. Payback period of the simulation is 3.9 years and 4.3 …

Gradient-Enriched Finite Element Methodology For Axisymmetric Problems, C. Bagni, H. Askes, E. C. Aifantis

Michigan Tech Publications, Part 1

Due to the axisymmetric nature of many engineering problems, bi-dimensional axisymmetric finite elements play an important role in the numerical analysis of structures, as well as advanced technology micro/nano-components and devices (nano-tubes, nano-wires, micro-/nano-pillars, micro-electrodes). In this paper, a straightforward C0-continuous gradient-enriched finite element methodology is proposed for the solution of axisymmetric geometries, including both axisymmetric and non-axisymmetric loads. Considerations about the best integration rules and an exhaustive convergence study are also provided along with guidances on optimal element size. Moreover, by applying the present methodology to cylindrical bars characterised by a circumferential sharp crack, the ability of the present …

Chemically Stable Artificial Sei For Li-Ion Battery Electrodes, Qinglin Zhang, Lei Han, Jie Pan, Zhi Chen, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

The importance of coating's chemical stability in lithium-ion batteries has been demonstrated by this study. It is well known that the mechanical properties determine the cycle life, and chemical stability or chemical degradation rate determines the calendar life. In this study, we used HfO₂ coatings prepared by atomic layer deposition as an example to show the chemical stability of the coatings for lithium ion battery electrodes.

A Study Of Corrosion Monitoring Techniques Used In Urls For Metals, Sirui Li

USF Tampa Graduate Theses and Dissertations

With the increasing use of fission-type nuclear power generation, particularly high-levels radioactive nuclear waste are generated, so the safe use of nuclear energy requires proper disposal of high-level radioactive nuclear waste. The selected treatment method is deep geological disposal. Therefore, underground research laboratory (URL) to prepare for deep geological disposal will also be carried out. Corrosion of metallic materials, which are closely related to the safety of URL, is the focus of this research project. This study selected monitoring techniques for URL and developed a rough monitoring scheme for temperature and resistivity in URL. In this study, corrosion-temperature and corrosion-resistivity …

A Study Of Iron-Nitrogen-Carbon Fuel Cell Catalysts: Chemistry – Nanostructure – Performance, Michael J. Workman

Nanoscience and Microsystems ETDs

Fuel cells have the potential to be a pollution-free, low-cost, and energy efficient alternative to the internal combustion engine for transportation and small-scale stationary power applications. The current state of fuel cell technology has already achieved two of these three lofty goals. The remaining barrier to wide-scale deployment is the high cost, which is primarily caused by dependence on large amounts of platinum to catalyze the energy conversion reactions. To overcome this barrier and facilitate the integration of fuel cells into mainstream applications, research into a new class of catalyst materials that do not require platinum is needed.

There has …

Creep Of Hi-Nicalon™ S Ceramic Fiber Tows At 900°C In Air And In Silicic Acid-Saturated Steam, Ronald K. Mitchell

Theses and Dissertations

Advanced SiC/SiC ceramic matrix composites (CMCs) are being considered for demanding aerospace applications such as aircraft engine hot-section components. In these applications the composites will be subjected to cyclic and sustained loadings at elevated temperature in aggressive combustion environments. Current aircraft engines employ Nickel-based superalloys in applications such turbine blades, where the metallic alloys must perform at or near their operating temperature limits in highly corrosive environments. The SiC/SiC composites, which offer low density, high strength and fracture toughness at elevated temperatures could potentially replace Nickel-based superalloy in aircraft engine applications. However, before the SiC/SiC composites can be safely used …

Building Energy Model Calibration For Retrofit Decision Making, Nicolas R. Johnson

Dissertations and Theses

Accommodating the continued increase in energy demand in the face of global climate change has been a worldwide concern. With buildings in the US consuming nearly 40% of national energy, a concerted effort must be given to reduce building energy consumption. As new buildings continue to improve their efficiency through more restrictive energy codes, the other 76.9 billion square feet of current building stock falls further behind. The rate at which current buildings are being retrofit is not enough and better tools are needed to access the benefits of retrofits and the uncertainties associated with them. This study proposes a …

Making Light-Weight Mg-Metal Laminated Nanocomposites, Soodabeh Azadehranjbar, Xinyan Xie, Jeffrey E. Shield, Jian Wang

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Magnesium is the lightest of all the engineering metals. Replacing steel structural materials with Mg-based materials in automotive applications would boost fuel. However, conventional Mg alloys typically suffer from low strength and poor deformability due to very few slip systems and easy twinning. Alloying Mg with other materials and microstructural engineering are promising approaches to increase ductility and strength of Mg. According to Wang et al., interfaces with low energy and high coherency may effectively constrict the nucleation of twins in Mg. In this work, Mg-metal multilayered nanocomposites will be produced by melt spinning procedure and the layers’ mechanical properties …

Transient Nonlinear Optical Properties Of Thin Film Titanium Nitride, Sarahkatie Thomas

Theses and Dissertations

nitride (TiN) and scandium nitride (ScN), using the beam deflection characterization technique. The thin films were made at the Air Force Research Lab by controllably unbalanced magnetron sputtering. Transition metal nitrides, specifically TiN, are used widely in industry because of their unique properties, including extreme hardness and high damage threshold. The properties of thin film transition metal nitrites are dependent on the chemical structure of the thin film, which can be heavily influenced by substrate and deposition method. This durability and tunability is an asset in applications such as sensor protection and all optical computing. Two substrates, sapphire (Al_{2 …}

Analysis Of Additively Manufactured Lattice Structures Using Finite Element Methods, Christopher A. Box

Theses and Dissertations

Additive Manufacturing (AM) processes are well known for their ability to fabricate parts with complex geometries. Lattice structures leverage this ability to create parts with high strength-to-weight ratio and other desirable structural qualities. This research presents a parameterized modeling tool using common Finite Element Analysis (FEA) and scripting software with which aggregated lattice structures can be analyzed, given different geometric properties and loading conditions. A full factorial Design of Experiments is run to explore the effects of various parameters on the strength of lattice structures. Experimental compressive strength results from three FDM-produced PLA lattices are discussed and compared to predictions …

Effects Of Microstructure And Alloy Concentration On The Corrosion And Tribocorrosion Resistance Of Al-Mn And We43 Mg Alloys, Hesham Y. Saleh Mraied

USF Tampa Graduate Theses and Dissertations

The design of new engineering materials resistant to both wear damage and corrosion degradation becomes increasingly demanding in complex service conditions. Unfortunately, there is typically a tradeoff between wear and corrosion resistance, even for important passive metals such as Al alloys. This is because the presence of precipitates hardens the material but at the same time lead to unfavorable galvanic coupling between the precipitates and the matrix, resulting in accelerated corrosion. This work showed that Al (or Mg) supersaturated solid solution formed using non-equilibrium methods exhibited enhanced corrosion resistance without compromising strength. For Al, alloying with Mn up to ~ …

Emerging Business Models For Open Source Hardware, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The rise of Free and Open Source models for software development has catalyzed the growth of Free and Open Source hardware (also known as “Libre Hardware”). Libre Hardware is gaining significant traction in the scientific hardware community, where there is evidence that open development creates both technically superior and far less expensive scientific equipment than proprietary models. In this article, the evidence is reviewed and a collection of examples of business models is developed to service scientists who have the option to manufacture their own equipment using Open Source designs. Profitable Libre Hardware business models are reviewed, which includes kit, …

Liquid-Gas Surface Tension Voltage Dependence During Electrowetting On Dielectric Of 5-90 Nm Gold Nanofluids, Saeid Vafaei, Karthik Chinnathambi, Theodorian Borca-Tasciuc

Materials Science and Engineering Faculty Publications and Presentations

This article investigates the effective liquid-gas surface tension changes of water and 5-90nm gold nanofluids measured during electrowetting on dielectric experiments. The Young-Laplace equation for sessile droplets in air was solved to fit the experimental droplet shape and determine the effective liquid-gas surface tension at each applied voltage. A good agreement between experimental droplet shapes and the predictions was observed for all the liquids investigated in applied range of 0-30V. The measured liquid-gas effective surface tensions of water and gold nanofluid decreased with voltage. At a given voltage, the effective liquid-gas surface tension of gold nanofluids initially decreased as the …

Engineered Nanocomposite Materials For Microwave/Millimeter-Wave Applications Of Fused Deposition Modeling, Juan De Dios Castro

USF Tampa Graduate Theses and Dissertations

A variety of high-permittivity (high-k) and low-loss ceramic-thermoplastic composite materials as fused deposition modeling (FDM) feedstock, based on cyclo-olefin polymer (COP) embedded with sintered ceramic fillers, have been developed and investigated for direct digital manufacturing (DDM) of microwave components. The composites presented in this dissertation use a high-temperature sintering process up to 1500°C to further enhance the dielectric properties of the ceramic fillers. The electromagnetic (EM) properties of these newly developed FDM composites were characterized up to the Ku-band by using the cavity perturbation technique. Several models for prediction of the effective relative dielectric permittivity of composites based …

Synthesis And Catalytic Applications Of Non-Metal Doped Mesoporous Titania, Syed Z. Islam, Suraj R. Nagpure, Doo Young Kim, Stephen E. Rankin

Chemical and Materials Engineering Faculty Publications

Mesoporous titania (mp-TiO₂) has drawn tremendous attention for a diverse set of applications due to its high surface area, interfacial structure, and tunable combination of pore size, pore orientation, wall thickness, and pore connectivity. Its pore structure facilitates rapid diffusion of reactants and charge carriers to the photocatalytically active interface of TiO₂. However, because the large band gap of TiO₂ limits its ability to utilize visible light, non-metal doping has been extensively studied to tune the energy levels of TiO₂. While first-principles calculations support the efficacy of this approach, it is challenging to …

Intracellular Nanoparticle Dynamics Affected By Cytoskeletal Integrity, Martha E. Grady, Emmabeth Parrish, Matthew A. Caporizzo, Sarah C. Seeger, Russell J. Composto, David M. Eckmann

Mechanical Engineering Faculty Publications

The cell interior is a crowded chemical space, which limits the diffusion of molecules and organelles within the cytoplasm, affecting the rates of chemical reactions. We provide insight into the relationship between non-specific intracellular diffusion and cytoskeletal integrity. Quantum dots entered the cell through microinjection and their spatial coordinates were captured by tracking their fluorescence signature as they diffused within the cell cytoplasm. Particle tracking revealed significant enhancement in the mobility of biocompatible quantum dots within fibrosarcoma cells versus their healthy counterparts, fibroblasts, as well as in actin destabilized fibroblasts versus untreated fibroblasts. Analyzing the displacement distributions provided insight into …

Tailoring Magnetic Behavior Of Cofemnnix (X = Al, Cr, Ga, And Sn) High Entropy Alloys By Metal Doping, Tingting Zuo, Michael C. Gao, Lizhi Ouyang, Xiao Yang, Yongqiang Cheng, Rui Feng, Shuying Chen, Peter K. Liaw, Jeffrey A. Hawk, Yong Zhang

Mathematical Sciences Faculty Research

Magnetic materials with excellent performances are desired for functional applications. Based on the high-entropy effect, a system of CoFeMnNiX (X = Al, Cr, Ga, and Sn) magnetic alloys are designed and investigated. The dramatic change in phase structures from face-centered-cubic (FCC) to ordered body-centered-cubic (BCC) phases, caused by adding Al, Ga, and Sn in CoFeMnNiX alloys, originates from the potent short-range chemical order in the liquid state predicted by ab initio molecular dynamics (AIMD) simulations. This phase transition leads to the significant enhancement of the saturation magnetization (Ms), e.g., the CoFeMnNiAl alloy has Ms of 147.86 Am2/kg. First-principles density functional …

Negahban Group Report: Saw-Tooth Shear Response Of Aged Poly(Methyl Methacrylate) (Pmma), Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

Results for isothermal saw-tooth shear loading experiments conducted on annealed and oven-cooled poly(methyl methacrylate) (PMMA) at temperatures between 50^oC and 140^oC. The experiments were conducted 1996.

Universal Slip Dynamics In Metallic Glasses And Granular Matter – Linking Frictional Weakening With Inertial Effects, Dmitri V. Denisov, Kinga A. Lorincz, Wendelin J. Wright, Todd C. Hufnagel, Aya Nawano, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen, Peter Schall

Faculty Journal Articles

Slowly strained solids deform via intermittent slips that exhibit a material-independent critical size distribution. Here, by comparing two disparate systems - granular materials and bulk metallic glasses - we show evidence that not only the statistics of slips but also their dynamics are remarkably similar, i.e. independent of the microscopic details of the material. By resolving and comparing the full time evolution of avalanches in bulk metallic glasses and granular materials, we uncover a regime of universal deformation dynamics. We experimentally verify the predicted universal scaling functions for the dynamics of individual avalanches in both systems, and show that both …

Defect-Related Optical Absorption Bands In Cdsip2 Crystals, Elizabeth M. Scherrer, Brant T. Kananen, Eric M. Golden, F. Kenneth Hopkins, Kevin T. Zawilski, Peter G. Schunemann, Larry E. Halliburton, Nancy C. Giles

Faculty Publications

When used as optical parametric oscillators, CdSiP₂ crystals generate tunable output in the mid-infrared. Their performance, however, is often limited by unwanted optical absorption bands that overlap the pump wavelengths. A broad defect-related optical absorption band peaking near 800 nm, with a shoulder near 1 µm, can be photoinduced at room temperature in many CdSiP₂ crystals. This absorption band is efficiently produced with 633 nm laser light and decays with a lifetime of ∼0.5 s after removal of the excitation light. The 800 nm band is accompanied by a less intense absorption band peaking near 1.90 µm. Data …

Lateral Strength And Ductile Behavior Of A Mortise-Tenon Connected Timber Frame, Alexandros Kouromenos

Master's Theses

The primary goals of this project were to examine the amount of lateral force resisted by a single-bay mortise-tenon connected timber moment frame, and to introduce ductile behavior into the mortise-tenon connections by adding a steel sleeve around a traditional wood peg. This research aimed to provide proof that traditional timber frames are capable of ductile racking while reliably complying with ASCE 7-10 building code drift speci! cations, implying an increase in the ASCE 7-10 ductility factor (R) for wood frames when used as lateral force resisting elements. A secondary goal was to promote traditional heavy timber framing as a …

Incorporating Poly(3-Hexyl Thiophene) Into Orthogonally Aligned Cylindrical Nanopores Of Titania For Optoelectronics, Suraj R. Nagpure, James F. Browning, Stephen E. Rankin

Chemical and Materials Engineering Faculty Publications

The incorporation of hole conducting polymer poly(3-hexyl thiophene) (P3HT) into the 8-9 nm cylindrical nanopores of titania is investigated using films with a unique orthogonally oriented hexagonal close packed mesostructure. The films are synthesized using evaporation induced self-assembly (EISA) with Pluronic triblock copolymer F127 as the structure directing agent. The orthogonally oriented cylindrical nanopore structure was chosen over a cubic structure because confinement in uniform cylindrical channels is hypothesized to enhance hole conductivity of P3HT by inducing local polymer chain ordering. Orthogonal orientation of the cylindrical nanopores is achieved by modifying the substrate (FTO-coated glass slides) with crosslinked F127. After …

Toxicity Evaluation Of Magnetic Hyperthermia Induced By Remote Actuation Of Magnetic Nanoparticles In 3d Micrometastasic Tumor Tissue Analogs For Triple Negative Breast Cancer, Nathanael A. Stocke, Pallavi Sethi, Amar Jyoti, Ryan Chan, Susanne M. Arnold, J. Zach Hilt, Meenakshi Upreti

Chemical and Materials Engineering Faculty Publications

Magnetic hyperthermia as a treatment modality is acquiring increased recognition for loco-regional therapy of primary and metastatic lung malignancies by pulmonary delivery of magnetic nanoparticles (MNP). The unique characteristic of magnetic nanoparticles to induce localized hyperthermia in the presence of an alternating magnetic field (AMF) allows for preferential killing of cells at the tumor site. In this study we demonstrate the effect of hyperthermia induced by low and high dose of MNP under the influence of an AMF using 3D tumor tissue analogs (TTA) representing the micrometastatic, perfusion independent stage of triple negative breast cancer (TNBC) that infiltrates the lungs. …

6 Field-Observed Cracking Of Paired Lightweight And Normalweight Concrete Bridge Decks, Tara L. Cavalline, Jeremy T. Calamusa, Amy M. Kitts, Brett Q. Tempest

Engineering Technology Faculty Publications

Research has suggested that conventional lightweight concrete can offer durability advantages due to reduced cracking tendency. Although a number of publications exist providing the results of laboratory-based studies on the durability performance of lightweight concrete (with lightweight coarse aggregate) and internally cured concrete (using prewetted lightweight fine aggregate), far fewer field studies of durability performance of conventional lightweight concrete bridge decks in service have been performed. This study was commissioned to provide insight to a highway agency on whether enhanced durability performance, and therefore reduced maintenance and longer lifecycles, could be anticipated from existing lightweight concrete bridge decks that were …

Formation Of Mound-Like Multiscale Surface Structures On Titanium By Femtosecond Laser Processing, Edwin Peng, Alfred Tsubaki, Craig A. Zuhlke, Ryan Bell, Meiyu Wang, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Surface Functionalization Technique • Femtosecond Laser Surface Processing (FLSP) • Utilize high power, femtosecond (10-15 s) laser pulses • Produce self-organized, multiscale surface micro/nanostructures • Diverse range of applicable substrates: semiconductors, metals, polymers, & composites

Why? • What are the different types of FLSP structures on Ti? • Physical evidence needed for FLSP formation models • Optimize FLSP of Ti for biomedical & other applications

How? • Obtain evidence of mound growth processes by examining underlying microstructure • Utilize dual beam Scanning Electron Microscope-Focused Ion Beam instrument to cross section surface structures & fabricate transmission electron microscopy samples

Performance Of Piperidine Ionic Liquid Based Mixed Electrolyte In Li/Licoo2 Cell, Hu Cheng, Xiao-Yan Nie, Ye-Dan Shen

Journal of Electrochemistry

The N-methyl-N-ethyl (propyl, butyl) piperidinium bis (trifluo romethanesulfonyl) imide (PP12(3,4)TFSI) ionic liquids were prepared, and their influences on the performances of Li/LiCoO₂ cells were investigated. The electrochemical performance and thermostability of ionic liquids based mixed electrolytes were characterized by electrochemical methods and thermogravimetric analysis. The results showed that the piperidine ionic liquids could improve the thermostability of organic electrolyte, and the size of their side chain had played an important role on the electrochemical performance of Li/LiCoO₂ cell. The Li/LiCoO₂ cell used the electrolyte mixed with PP13TFSI exhibited the best electrochemical performance among the three ionic liquids. …

The Problem Of The Anode Electrolyte In H-Type Electrolytic Cell For Electrochemical Reduction Of Carbon Dioxide, Rui Zhang, Wei-Xin Lv, Li-Xu Lei

Journal of Electrochemistry

Electrochemical reduction of carbon dioxide (CO₂) was studied in the H-type electrolytic cell. It was found that the voltage between the cathode and the anode would increase during the long time electrolysis process, for this reason the electrolytic process would be unsustainable. After the experimental investigations carried out by constant potential electrolysis, constant current electrolysis, pH test and KHCO₃ concentration analysis of anode electrolyte before and after the electrolysis, the increase in cell voltage might be caused by the following process: H⁺, that was generated from the anodic oxygen evolution reaction, reacted with HCO_{3 …}

Effects Of Flame Retardant On The Rate Capability And Safety Performances Of The Soft-Package 5ah Lithium Ion Battery, Yan-Zhuo Lv, Xiao-He Wang, Yi-Ming Qin, Zhen-Bo Wang, Ke Ke

Journal of Electrochemistry

The 5 Ah soft packed lithium ion batteries with LiNi _0.4Co_0.2Mn_0.4 O₂ as the positive electrode material and the organic electrolytes with different amounts of fire retardants as the electrolyte solution were prepared. The effects of the fire retardant amount (5 %,10 %,20 %) of the fire retardants on the rate performances, short-circuit characteristics and overcharged behaviors of the 5 Ah soft packed lithium ion battery were investigated by electrochemical methods. The results indicated that the best rate performances were obtained by adding 5 vol.% of the fire retardants in the electrolyte solution when the …