A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, 2015 The British University in Egypt
A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din
Centre for Advanced Materials
Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested predicting the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to …
Seeing Red: Characterizing Historic Bricks At Sylvester Manor, Long Island, Ny 1652-1735, 2014 University of Massachusetts Boston
Seeing Red: Characterizing Historic Bricks At Sylvester Manor, Long Island, Ny 1652-1735, Martin John Schmidheiny
Graduate Masters Theses
The goal of this project is to develop a basic material characterization of the bricks excavated at the site of Sylvester Manor on Shelter Island, New York. In the early Manor period of 1650-1690, this early Northern provisioning plantation supplied Barbadian sugar operations and pursued mercantile interests independent of state control. Accounting for the range of production defects and material characteristics of the bricks suggests on-site or local manufacture as a regional ceramic industry developed. Qualitative visual analysis and petrographic thin-sections were used to characterize the internal composition, variation and production evidence in the bricks. Interpreting the results of this …
Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, 2014 The University of Western Ontario
Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, Yongsheng Zhang
Electronic Thesis and Dissertation Repository
The phenol-formaldehyde (PF) resin manufacturing industry is facing a growing challenge with respect to concerns over human health, due to the use of carcinogenic formaldehyde and sustainability due to the use of petroleum-based phenol in PF resin manufacture. Glucose and its derivative, 5-hydroxymethylfurfural (5-HMF), have proven to be potential substitutes for formaldehyde in the synthesis of phenolic novolac resins.
This thesis investigated a number of glucose and 5-HMF resin systems including the curing of phenol-glucose novolac resin (PG) with a bis-phenol-A type epoxy. The curing process was modeled according to the Sestak-Berggren equation (S, B) using Málek methods. This was …
Influence Of Texture And Grain Size On The Plastic Anisotropy In A Wrought Mg Alloy: Synchrotron X-Ray Diffraction And Visco-Plastic Self-Consistent Modeling, 2014 University of Tennessee - Knoxville
Influence Of Texture And Grain Size On The Plastic Anisotropy In A Wrought Mg Alloy: Synchrotron X-Ray Diffraction And Visco-Plastic Self-Consistent Modeling, Yi Wang
Doctoral Dissertations
The combined effects of texture and grain size on the yielding and hardening behavior in a hot-rolled AZ31B Mg alloy were studied by using synchrotron x-ray diffraction and visco-plastic self-consistent (VPSC) simulation methods.
First, the influence of texture on Hall-Petch relationships (namely, critical resolved shear stresses and hardening parameters) in a Mg alloy was investigated to establish a constitutive basis for the VPSC simulation.
Then, the changes in dominant deformation mechanisms (basal, prismatic, and pyramidal slip as well as extension twin) and their relative interactions were studied systematically as a function of the initial texture using a VPSC scheme. The …
Investigation Of Deformation And Failure Mechanisms In Nanoindentation Mechanics, 2014 University of Tennessee - Knoxville
Investigation Of Deformation And Failure Mechanisms In Nanoindentation Mechanics, Yuzhi Xia
Doctoral Dissertations
This dissertation further extends nanoindentation to study the initiation of plasticity in single crystals in nanoscale stressed volumes, to the instrumented tests for damage evaluation and monitoring, and to the fundamental issues in deformation and failure mechanisms in relationship to the defect evolutions.
In the first project, model Fe-Cr, Fe-Ni and Fe-Cr-Ni alloys that are the basis of many structural steels were synthesized as single crystals and characterized. The compositions investigated were Fe-15Cr, Fe-30Cr, Fe-30Ni and Fe-15Cr-15Ni (atomic percent). Several key mechanical properties were determined which will be useful in further studies of irradiation/deformation-induced defects. Incipient plasticity and slip characteristics …
Fatigue, Fracture, And Environmentally-Assisted Behavior Of Advanced Engineering Materials, 2014 University of Tennessee - Knoxville
Fatigue, Fracture, And Environmentally-Assisted Behavior Of Advanced Engineering Materials, Zhi Tang
Doctoral Dissertations
The objective of the present study is to provide a fundamental understanding of fatigue, fracture, and environmentally-assisted behavior of high-entropy alloys (HEAs). The work involves fatigue, fracture, and environmentally-assisted behavior of a new kind of advanced engineering materials, called HEAs. Three tasks are studied: (1) microstructures and fracture mechanisms of HEAs, (2) fatigue failure and life prediction of HEAs, and (3) corrosion and environmentally-assisted behavior of HEAs.
In the first task, microstructural stability and fracture mechanism of the AlCoCrFeNi alloy are studied and compared with thermodynamic calculations. In the second task, high-cycle fatigue-failure mechanisms of the cold-rolled Al0.5CoCrCuFeNi alloy are …
Development Of Micro-Hall Devices For Current Sensing, 2014 University of Arkansas, Fayetteville
Development Of Micro-Hall Devices For Current Sensing, Thomas White
Graduate Theses and Dissertations
In this work, micro-Hall devices were developed for the purpose of sensing current within a high temperature and high power environment. GaAs HEMT, InGaAs pHEMT, and GaN HEMT structures were studied. These structures were grown by molecular beam epitaxy. Processing techniques including photolithography, metallization, Si deposition, wet etching, and dry etching were studied. Electrical characterization measurements including low frequency noise, Hall effect, sensitivity, capacitance-voltage, and current-voltage were performed.
Electron mobility and sheet carrier density studies were performed for both the InGaAs pHEMT and GaAs HEMT structures. Results indicated the InGaAs pHEMT was superior and thus fabricated as the micro-Hall device. …
Reverse Engineering Of Reciprocating Saw, 2014 University of Tennessee, Knoxville
Reverse Engineering Of Reciprocating Saw, Nicholas Alexander Cavopol, Candice Kinsler, Carly Jania, Joseph Richard Creekmore
Chancellor’s Honors Program Projects
No abstract provided.
Early-Age Hydration Studies Of Portland Cement, 2014 University of Louisville
Early-Age Hydration Studies Of Portland Cement, Fengjuan Liu
Electronic Theses and Dissertations
Our current knowledge on cement hydration during setting is based on the discrete observation of hydrated paste. An advanced micro/nano-level technique which can perform the in-situ observation on the continuous hydration of cement paste is demanded. In this study, Raman spectroscopy (RS) was chosen as such a method to continuously investigate wet pastes. The objective of this research is to explore the hydration process and microstructural development of fresh pastes with this technique. This research was conducted in three phases. First, the RS analysis was used to continuously observe the cement hydration from 20 minutes after mixing to 9 hours. …
Atom-Based Geometrical Fingerprinting Of Conformal Two-Dimensional Materials, 2014 University of Arkansas, Fayetteville
Atom-Based Geometrical Fingerprinting Of Conformal Two-Dimensional Materials, Mehrshad Mehboudi
Graduate Theses and Dissertations
The shape of two-dimensional materials plays a significant role on their chemical and physical properties. Two-dimensional materials are basic meshes that are formed by mesh points (vertices) given by atomic positions, and connecting lines (edges) between points given by chemical bonds. Therefore the study of local shape and geometry of two-dimensional materials is a fundamental prerequisite to investigate physical and chemical properties. Hereby the use of discrete geometry to discuss the shape of two-dimensional materials is initiated.
The local geometry of a surface embodied in 3D space is determined using four invariant numbers from the metric and curvature tensors which …
The Development Of A Laminated Copolyester Electric Guitar, 2014 East Tennessee State University
The Development Of A Laminated Copolyester Electric Guitar, Addison S. Karnes
Electronic Theses and Dissertations
This thesis is an investigation of the fabrication and assembly methodologies employed in the development of a proof-of-principle prototype electric guitar composed of laminated copolyester. The objective of the project was to develop the processes and procedures to create an optimized physical and visual bond between layers to minimize vibratory dissipation, thus maximizing sustain. A high speed CNC router, abrasive waterjet, laser engraver-cutter, as well as various manual fabrication and assembly methods were investigated in the construction of the guitar prototypes. The lamination processes explored include low-temperature, heat-assisted pressure bonding, solvent and chemical welding, and contact adhesives. The project concluded …
High Strength Steel Fiber Reinforced Flow-Able Or Scc Concrete With Variable Fiber By Volume Fractions For Thin Plate And Shell Structures, 2014 University of Nevada, Las Vegas
High Strength Steel Fiber Reinforced Flow-Able Or Scc Concrete With Variable Fiber By Volume Fractions For Thin Plate And Shell Structures, Abebe Berhe
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purpose of this study is to incorporate discrete, short, mechanically deformed, small diameter steel fibers into high strength concrete with f'c > 70 MPa (10 ksi) in an attempt to reduce and partially eliminate the need for steel rebar in concrete construction. By introducing steel fibers to high strength concrete mixture, the overall tensile, compressive and shear strength of the mixture can be improved immensely thus, replacing portions or major parts of the longitudinal, temperature and shrinkage reinforcements. The reduction or elimination of longitudinal and transverse reinforcements in the construction of structural or non-structural members can result in savings in …
Functional Nanocomposites From Self-Assembly Of Block Copolymers With Nanoparticles, 2014 University of Massachusetts Amherst
Functional Nanocomposites From Self-Assembly Of Block Copolymers With Nanoparticles, Xinyu Wang
Doctoral Dissertations
This dissertation studied the proper distribution and location control of nanoparticles (NPs) within block copolymer (BCP) templates. A facile ligand exchange reaction was introduced for the hydrophilic magnetic NPs (MNPs) that are readily dispersed in polar solvents with outstanding stability. Small molecule ligands were selected to associate strongly with particle surfaces, provide hydrophilic termini for polarity matching with polar solvents, and offer the potential for hydrogen-bonding interactions to facilitate NP incorporation into polymers. Areal ligand densities of NPs indicated a significant increase in the ligand coverage after the exchange reaction. Hydrophilic MNPs were shown to drive the self-assembly of BCPs …
He+ Ion Irradiation On Tungsten Surface In Extreme Conditions, 2014 Purdue University
He+ Ion Irradiation On Tungsten Surface In Extreme Conditions, George I. Joseph, Jitendra Tripathi, Sivanandan S. Harilal, Ahmed Hassanein
The Summer Undergraduate Research Fellowship (SURF) Symposium
Higher melting point (3695K), lower sputtering yield and most importantly, lower in-bulk, and co-deposit retention at elevated temperature makes tungsten (W) as a potential candidate for plasma-facing component (PFC) in the international thermonuclear experimental reactor (ITER)-divertor. Helium ion (He+) bombardment on W can cause wide variety of microstructural evolution, such as dislocation loops, helium holes/bubbles and fibre-form nanostructures (Fuzz) etc. In this work, 100 eV He+ ion irradiation, at temperature ranges from 500°C to 1000°C, will be performed on mechanically polished mirror like W surfaces. The surface modification and compositional analysis, due to ion irradiation, will be …
Synthesis And Thermoelectric Properties Of Cusbs2, 2014 Purdue University
Synthesis And Thermoelectric Properties Of Cusbs2, Tianyue Gao, Haiyu Fang, Yue Wu
The Summer Undergraduate Research Fellowship (SURF) Symposium
Copper antimony sulfide, CuSbS2 nanoparticles have a large potential of being a good thermoelectric material because they are made up of earth abundant elements. Thermoelectric materials can convert thermal energy into electricity, so that the wasted energy can be saved. Also, by using this earth abundant material, we can make thermoelectric materials much cheaper. The hypothesis of this study is that CuSbS2 could have a large Seebeck coefficient, one of the most important factors of thermoelectric materials, because of the complexity of its band structure. The other hypothesis is that thermal transport could be significantly suppressed through nanostructuring. There are …
Finite Element Analysis Of Bolted Connections Under Fire, 2014 Purdue University
Finite Element Analysis Of Bolted Connections Under Fire, Ke Liu, Qiaqia Zhu, Amit H. Varma
The Summer Undergraduate Research Fellowship (SURF) Symposium
Over the course of human history, fire disasters are one of the major catastrophes that causes loss of lives and properties. In order to ensure building safety against fire, civil engineers seek to understand the behavior of structures at high temperatures. Moreover, they need to study the behavior of bolted connections, given the important role it plays in steel structures. Sarraj (2007) proposed a plate-bearing computational model used to describe this behavior; however, it has never been experimentally verified. Prior to this specific project, a series of single-bolted connection tests at 400°C and 600°C were conducted in the Bowen Laboratory …
Microstructure Development Of Granular System During Compaction, 2014 Purdue University
Microstructure Development Of Granular System During Compaction, Chen Shang, Marcial Gonzalez
The Summer Undergraduate Research Fellowship (SURF) Symposium
Granular materials is the second most manipulated material in the industry today. They are easy to transport and more and more newly developed materials cannot stand the process of traditional casting, like energetic materials and bio-materials, but will survive the powder compaction process. Having a better understanding of the microstructure development of granular systems during compaction process, especially for particles that will heavily deform under loading, will give an insight of how to better process the powders to produce materials with overall better performance comparing to bulk materials. The main theory and mechanism applied are Hertz law and nonlocal contact …
Dynamic Response Of Textile Material Under Transverse Impact, 2014 Purdue University
Dynamic Response Of Textile Material Under Transverse Impact, Yuchen Zheng, Matthew C. Hudspeth, Weinong W. Chen
The Summer Undergraduate Research Fellowship (SURF) Symposium
Textile materials, such as Dyneema and Kevlar, are the major raw materials for state of the art military or personal security armor vests. However, in impact experiments, actual observed penetration speed is much lower than theoretically predicted penetration speed. Each armor vest is composed of high performance yarns which are woven together to form fabrics, which when stacked together form a vest. Understanding penetration behavior of yarns is essential to evaluate the performance of fabric, which will be useful for the design of better vests. The project is composed of three parts: static experiments, dynamic yarn experiments and dynamic fabric …
Fiber Length And Orientation In Long Carbon Fiber Thermoplastic Composites, 2014 University of Central Florida
Fiber Length And Orientation In Long Carbon Fiber Thermoplastic Composites, Imad Hanhan, Connor Sullivan, Bhisham Sharma, Michael Sangid
The Summer Undergraduate Research Fellowship (SURF) Symposium
Carbon fiber composites have become popular in aerospace applications because of their lightweight yet strong material properties. The injection molding process can be used to produce discontinuous fiber composites using less time and resources than traditional methods, thereby broadening carbon fiber composites’ applications in different industries. Utilization of longer fibers offers more load carrying capability and superior strength properties for injected molded composites. Since the fiber length and the orientation distribution in Long Fiber Thermoplastics (LFTs) directly affects LFT composites’ material properties, there is a need to study the microstructure of LFTs and characterize fiber length and orientation distributions. Therefore, …
Bio-Inspired Helicoidal Composites: 3d Printing And Experiments, 2014 Purdue University
Bio-Inspired Helicoidal Composites: 3d Printing And Experiments, Michael E. Jones, Pablo Zavattieri, Nobphadon Suksangpanya
The Summer Undergraduate Research Fellowship (SURF) Symposium
Materials that are impact resistant enough for personal protection in sports, transport, and combat are not also lightweight, strong, tough, and impact tolerant. Nature can provide inspiration for novel materials that can meet these needs. The hierarchical composite of the stomatopod’s, or mantis shrimp’s, dactyl club has been shown to have high impact resistance and damage tolerance due to its helicoidal fiber reinforcement(1,2). Analyzing helicoidal composites of different pitch angles (angles between adjacent rows of fibers) under quasi-static, displacement-controlled loading has provided insights into the fracture mechanisms of the composite structure and how they affect the macroscopic properties of the …