Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, 2016 Portland State University
Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko
Dissertations and Theses
Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …
Morphological And Material Effects In Van Der Waals Interactions, 2016 University of Massachusetts Amherst
Morphological And Material Effects In Van Der Waals Interactions, Jaime C. Hopkins
Doctoral Dissertations
Van der Waals (vdW) interactions influence a variety of mesoscale phenomena, such as surface adhesion, friction, and colloid stability, and play increasingly important roles as science seeks to design systems on increasingly smaller length scales. Using the full Lifshitz continuum formulation, this thesis investigates the effects of system materials, shapes, and configurations and presents open-source software to accurately calculate vdW interactions. In the Lifshitz formulation, the microscopic composition of a material is represented by its bulk dielectric response. Small changes in a dielectric response can result in substantial variations in the strength of vdW interactions. However, the relationship between these …
Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, 2016 University of Massachusetts Amherst
Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, Dana Erin Wong
Doctoral Dissertations
The partnership of biocatalysts and solid support materials provides many opportunities for bioactive packaging and bioprocessing aids beneficial to the agricultural and food industries. Biocatalysis, or reactions modulated by enzymes, allows bioactive materials to assist in bringing a substrate to product. Enzymes are proteins which catalyze reactions by lowering the activation energy required to drive the production of a desired product. Enzymes are commonly utilized in food processing as catalysts with specificity in order to enhance product quality through the production of beneficial food components, and to break down undesirable components that may be harmful or may decrease product quality. …
Frequency Multiplication In Silicon Nanowires, 2016 Portland State University
Frequency Multiplication In Silicon Nanowires, Marius Mugurel Ghita
Dissertations and Theses
Frequency multiplication is an effect that arises in electronic components that exhibit a non-linear response to electromagnetic stimuli. Barriers to achieving very high frequency response from electronic devices are the device capacitance and other parasitic effects such as resistances that arise from the device geometry and are in general a function of the size of the device. In general, smaller device geometries and features lead to a faster response to electromagnetic stimuli. It was posited that the small size of the silicon nanowires (SiNWs) would lead to small device capacitance and spreading resistance, thus making the silicon nanowires useful in …
Studies On The Electrical Transport Properties Of Carbon Nanotube Composites, 2016 Louisiana Tech University
Studies On The Electrical Transport Properties Of Carbon Nanotube Composites, Taylor Warren Tarlton
Doctoral Dissertations
This work presents a probabilistic approach to model the electrical transport properties of carbon nanotube composite materials. A pseudo-random generation method is presented with the ability to generate 3-D samples with a variety of different configurations. Periodic boundary conditions are employed in the directions perpendicular to transport to minimize edge effects. Simulations produce values for drift velocity, carrier mobility, and conductivity in samples that account for geometrical features resembling those found in the lab. All results show an excellent agreement to the well-known power law characteristic of percolation processes, which is used to compare across simulations. The effect of sample …
Three-Dimensional Printing And Nanotechnology For Enhanced Implantable Materials, 2016 Louisiana Tech University
Three-Dimensional Printing And Nanotechnology For Enhanced Implantable Materials, Karthik Kumar Tappa
Doctoral Dissertations
Orthopedic and oro-maxillofacial implants have revolutionized treatment of bone diseases and fractures. Currently available metallic implants have been in clinical use for more than 40 years and have proved medically efficacious. However, several drawbacks remain, such as excessive stiffness, accumulation of metal ions in surrounding tissue, growth restriction, required removal/revision surgery, inability to carry drugs, and susceptibility to infection. The need for additional revision surgery increases financial costs and prolongs recovery time for patients. These metallic implants are bulk manufactured and often do not meet patient's requirements. A surgeon must machine (cut, weld, trim or drill holes) them in order …
Contribution Of Fiber Undulation To Mechanics Of Three-Dimensional Collagen-I Gel, 2016 University of Nebraska-Lincoln
Contribution Of Fiber Undulation To Mechanics Of Three-Dimensional Collagen-I Gel, Shengmao Lin, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
The collagen-I gel is extensively used as a scaffold material in tissue engineering due to its ability to mimic the extracellular matrix (ECM). In this study, the mechanics of collagen-I gel is investigated using a numerical model of three-dimensional collagen network. The resulted mechanical behavior was validated against the published experimental data. Results illustrated that fiber alignment was dominated in the low strain region, and its transition to stretching dominated phenomena at higher strain led to the strain stiffening of collagen gel. The collagen undulation at the microscopic level was found to delay the initiation of strain stiffening
Investigation Of Carbon Nanomaterials Embedded In A Cementitious Matrix, 2016 Western Kentucky University
Investigation Of Carbon Nanomaterials Embedded In A Cementitious Matrix, Clarissa A. Roe
Masters Theses & Specialist Projects
The objective of this thesis was to investigate whether the addition of carbon nanofibers had an effect on the splitting tensile strength of Hydro-Stone gypsum concrete. The carbon nanofibers used were single-walled carbon nanotubes (SWNT), buckminsterfullerene (C60), and graphene oxide (GO). Evidence of the nanofibers interacting with gypsum crystals in a connective manner was identified in both 1 mm thick concrete discs and concrete columns possessing a height of 2 in and a diameter of 1 in. Before imaging, the columns were subjected to a splitting tensile strength test. The results illustrate that while there is a general decrease in …
Predictive Coupled-Cluster Isomer Orderings For Some SiNCM (M, N ≤ 12) Clusters: A Pragmatic Comparison Between Dft And Complete Basis Limit Coupled-Cluster Benchmarks, Jason N. Byrd, Jesse J. Lutz, Duminda S. Ranasinghe, Yifan Jin, Ajith Perera, Xiaofeng F. Duan, Larry W. Burggraf, John A. Montgomery Jr.
Faculty Publications
The accurate determination of the preferred Si12C12 isomer is important to guide experimental efforts directed towards synthesizing SiC nano-wires and related polymer structures which are anticipated to be highly efficient exciton materials for opto-electronic devices. In order to definitively identify preferred isomeric structures for silicon carbon nano-clusters, highly accurate geometries, energies and harmonic zero point energies have been computed using coupled-cluster theory with systematic extrapolation to the complete basis limit for set of silicon carbon clusters ranging in size from SiC3 to Si12C12. It is found that post-MBPT(2) correlation energy plays a …
Nano Clay-Enhanced Calcium Phosphate Cements And Hydrogels For Biomedical Applications, 2016 Louisiana Tech University
Nano Clay-Enhanced Calcium Phosphate Cements And Hydrogels For Biomedical Applications, Udayabhanu Jammalamadaka
Doctoral Dissertations
Biomaterials are used as templates for drug delivery, scaffolds in tissue engineering, grafts in surgeries, and support for tissue regeneration. Novel biomaterial composites are needed to meet multifaceted requirements of compatibility, ease of fabrication and controlled drug delivery. Currently used biomaterials in orthopedics surgeries suffer limitations in toxicity and preventing infections. Polymethyl methacrylate (PMMA) used as bone cement suffers from limitations of thermal necrosis and monomer toxicity calls for development of better cementing biomaterials. A biodegradable/bioresorbable cement with good mechanical properties is needed to address this short coming. Metal implants used in fixing fractures or total joint replacement needs improvements …
The Experiment And Analysis Of Active Mechanisms For Enhancing Heat And Mass Transfer In Sorption Fluids, 2016 University of Nebraska-Lincoln
The Experiment And Analysis Of Active Mechanisms For Enhancing Heat And Mass Transfer In Sorption Fluids, Ziqi Shen
Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research
This project was funded by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE RP-1462). It is a three years’ research, including the literature review, labs construction, experiments and data analysis.
In this thesis, first of all, we conducted literature review of mechanism motion influence on heat and mass transfer and additive effect in absorption chiller. This part helps us understand the basic idea of how mechanism motion affects the heat and mass transfer of sorption fluids and gives us reference on how to select the experiment instrument and the experiment operation range.
In the second part, the instrument selection …
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, 2016 Western Kentucky University
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner
Mathematics Faculty Publications
A basic kinetic model that incorporates a coupled dynamics of the carbon atoms and dimers ona copper surface is used to compute growth of a single-layer graphene island. The speed of theisland's edge advancement on Cu[111] and Cu[100] surfaces is computed as a function of the growthtemperature and pressure. Spatially resolved concentration pro les of the atoms and dimers aredetermined, and the contributions provided by these species to the growth speed are discussed.Island growth in the conditions of a thermal cycling is studied.
Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, 2016 University of South Florida
Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili
USF Tampa Graduate Theses and Dissertations
Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …
Preparation And Characterization Of Van Der Waals Heterostructures, 2016 University of South Florida
Preparation And Characterization Of Van Der Waals Heterostructures, Horacio Coy Diaz
USF Tampa Graduate Theses and Dissertations
In this dissertation different van der Waals heterostructures such as graphene-MoS2 and MoTe2-MoS2 were prepared and characterized. In the first heterostructure, polycrystalline graphene was synthesized by chemical vapor deposition and transferred on top of MoS2 single crystal. In the second heterostructure, MoTe2 monolayers were deposited on MoS2 by molecular beam epitaxy.
Characterization of graphene-MoS2 heterostructures was conducted by spin and angle resolve spectroscopy which showed that the electronic structure of the bulk MoS2 and graphene in this van der Waals heterostructures is modified. For MoS2 underneath the graphene, a band …
Electrochemical And In Situ X-Ray Absorption Fine Structure Study Of Li-Rich Cathode Materials, 2016 Department of Chemistry, Fudan University, Shanghai, 200433, China;Shanghai Institute of Applied Physics, CAS, Shanghai, 201800;
Electrochemical And In Situ X-Ray Absorption Fine Structure Study Of Li-Rich Cathode Materials, Meng-Yan Hou, Hong-Liang Bao, Ke Wang, Jian-Qiang Wang, Yong-Yao Xia
Journal of Electrochemistry
A series of the lithium-rich and manganese-based layered structure xLi2MnO3•(1-x)LiMn1/3Ni1/3Co1/3O2 (x = 0.3,0.5,0.7) materials were synthesized by a co-precipitation method, and followed by a solid-state reaction process. By comparing the first cycle efficiency, the reversible discharge capacity, the cycling stability and the voltage decay during the charge/discharge cycling process, the material with the composition of 0.5Li2MnO3•0.5LiMn1/3Ni1/3Co1/3O2was found to show the best electrochemical performance. The lithium storage mechanism and thermal stability of the de-lithiated compound were also investigated …
Electrochemiluminescence Immunosensor Based On Platinum Nanoparticles For The Determination Of Apolipoprotein A1, 2016 College of Biological and Chemical Engineering, Panzhihua University, Panzhihua 617000, Sichuan, China;
Electrochemiluminescence Immunosensor Based On Platinum Nanoparticles For The Determination Of Apolipoprotein A1, Liao Ni, Zhuo Ying, Yuan Ruo
Journal of Electrochemistry
In this paper, a novel electrochemiluminescence (ECL) immunosensor for the detection of apolipoprotein A1 was constructed based on flower-like platinum nanoparticles (PtNFs) via a one-pot chemical synthesis method. The PtNFs was used to immobilize the secondary antibody and enzyme (GOD). Then the prepared bioconjugates were introduced onto the electrode via sandwich immunoreactions. Accordingly, the ECL luminophore peroxydisulfate (S2O82- ) was presented in the working buffer solution containing an appropriate amount of glucose. Through the ECL responses of S2O82- and O2, a dramatically amplified ECL signal was obtained for the reason …
Uniform Nanoshells For Functional Materials:Constructions And Applications, 2016 Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Science (CAS), Beijing 100190, P. R. China;
Uniform Nanoshells For Functional Materials:Constructions And Applications, Shu-Yi Duan, Wei Zhang, Jun-Yu Piao, An-Min Cao, Li-Jun Wan
Journal of Electrochemistry
As a significant protocol for materials treatment, surface modification has found broad applications in different fields including catalyst, photochemistry, and electrochemistry. Herein, we introduced the representative synthetic methodologies for the constructions of different functional materials with a focus on their core-shell structures. By taking the electrode materials in lithium ion batteries as an example, we demonstrated the importance of surface modification on the electrode materials. Different coating materials ranging from metal oxides, metal phosphates to carbon have been discussed. We also showed that an accurate control on the surface layer can be crucial for optimizing the electrochemical performances of the …
Effects Of Electrode Off Centre On Trapped Thickness-Shear Modes In Contoured At-Cut Quartz Resonators, 2016 Zhengzhou University
Effects Of Electrode Off Centre On Trapped Thickness-Shear Modes In Contoured At-Cut Quartz Resonators, Junjie Shi, Cuiying Fan, Minghao Zhao, Jiashi S. Yang
Department of Mechanical and Materials Engineering: Faculty Publications
We investigated thickness-shear vibrations of a contoured, AT-cut quartz resonator with a pair of electrodes displaced from the resonator centre. The scalar differential equations by Stevens and Tiersten for thickness-shear vibrations of electroded and unelectroded quartz plates were employed. Based on the variational formulation of the scalar differential equations established in a previous paper and the variation-based Ritz method with trigonometric functions as basis functions, free vibration resonance frequencies and trapped thickness-shear modes were obtained. The effects of the electrode off centre on resonance frequencies and mode shapes were examined. When the electrode off centre is about one hundredth of …
Hydrothermally Processed 1d Hydroxyapatite: Mechanism Of Formation And Biocompatibility Studies, 2016 Serbian Academy of Sciences and Arts
Hydrothermally Processed 1d Hydroxyapatite: Mechanism Of Formation And Biocompatibility Studies, Zoran Stojanović, Nenad Ignjatović, Victoria M. Wu, Vojca Žunič, Ljiljana Veselinović, Srečo D. Škapin, Miroslav Miljković, Vuk Uskoković, Dragab Uskoković
Pharmacy Faculty Articles and Research
Recent developments in bone tissue engineering have led to an increased interest in one-dimensional (1D) hydroxyapatite (HA) nano- and micro-structures such as wires, ribbons and tubes. They have been proposed for use as cell substrates, reinforcing phases in composites and carriers for biologically active substances. Here we demonstrate the synthesis of 1D HA structures using an optimized, urea-assisted, high-yield hydrothermal batch process. The one-pot process, yielding HA structures composed of bundles of ribbons and wires, was typified by the simultaneous occurrence of a multitude of intermediate reactions, failing to meet the uniformity criteria over particle morphology and size. To overcome …
The Effect Of Relative Electrode Size On The Performance Of A Supercapacitive Microbial Fuel Cell Design, 2016 University of New Mexico
The Effect Of Relative Electrode Size On The Performance Of A Supercapacitive Microbial Fuel Cell Design, Jeremiah Houghton
Nanoscience and Microsystems ETDs
Supercapacitive microbial fuel cells with various anode and cathode dimensions were investigated in order to determine the effect on capacitance and delivered power quality. The cathode size was determined to be the limiting component of the system, while anode size showed little effect on the devices performance. By doubling the cathode area, peak power output was improved by roughly 120% for a 10 ms pulse discharge. Doubling the cathode area also had a positive effect on the internal resistance of the cell, lowering the equivalent series resistance by approximately 47%. Doubling the anode area increased peak power output slightly, with …