Engineering Commons^™

Multi-Component Nanofibrous Scaffolds With Tunable Properties For Bone Tissue Engineering, Moncy V. Jose

All ETDs from UAB

Bone is a highly complex tissue which is an integral part of vertebrates and hence any damage has a major negative effect on the quality of life. Tissue engineering is regarded as an ideal route to resolve the issues related to the scarcity of tissue and organ for transplantation. Apart from cell line and growth factors, the choice of materials and fabrication technique for scaffold are equally important. The goal of this work was to develop a multi-component nanofibrous scaffold based on a synthetic polymer (poly(lactic-co-glycolide) (PLGA)), a biopolymer (collagen) and a biomineral (nano-hydroxyapatite (na-no-HA)) by electrospinning technique, which mimics …

Optical Vehicular Tracking System, Joshua D. Jackson

All ETDs from UAB

This dissertation presents research and analysis specific to a well-defined methodology for a low-cost and accurate vehicle tracking system that performs within a spatially limited domain. The Alabama Department of Transportation (ALDOT) requires such a system to increase the efficiency of its bridge load-testing procedures. Currently, human operators estimate vehicle positions. As ALDOT seeks to modernize its systems, they require an accurate yet low-cost system for tracking load-testing vehicles within a spatially limited domain. This body of work presents a novel optical tracking system that makes use of the same optical navigation chip used in an optical computer mouse. Included …

Solidification Under Pressure Of Aluminum Castings, Pavan Chintalapati

All ETDs from UAB

Aluminum castings are widely used in automotive and other applications. These castings gained importance due to their high strength to weight ratio. However, aluminum castings are prone to porosity which significantly deteriorates the mechanical properties. Safety-critical components are subjected to hot isostatic pressing (HIPping), which heals the porosity. HIPping is a post-processing technique resulting in higher costs. An alterna-tive technique is application of pressure during solidification. The effect of application of 1.0132 MPa (150 psi) pressure during solidification on the cooling rate, soundness, pore characteristics and mechanical properties of alumi-num castings was investigated in the current research. Wedge castings of …

Flexural Creep Of Long Fiber Thermoplastic Composites: Effect Of Constituents And Variables On Viscoelasticity, Venkata Sankaranand Chevali

All ETDs from UAB

Long fiber thermoplastic (LFT) composites are used primarily in various automotive and military applications. LFT mechanical properties are dictated by the polymer matrix and fiber reinforcements, and are affected by processing. As LFTs deform under moderate loads and moderate temperatures, flexural creep raises concerns about longevity. The present study is an analysis of creep as a function of constituents and variables, and the development of predictive estimation methods. Compressionmolded high-density polyethylene, nylon 6/6, and polypropylene and their 10 and 40 wt. % LFT composites were studied. The LFTs showed non-linear viscoelasticity, quantitatively described using an empirical model formerly used for …

Information Theoretical Modeling Of Complex Communication Network Usage Patterns, Stanley Carl Thompson

All ETDs from UAB

Today’s voice and data connectivity typically utilizes a complex system of networks of networks. The development of models for characterizing usage patterns in complex networks would be useful in projecting capacity requirements in growing systems. Simplified models applied to a complex network for timing and sizing algorithms would significantly reduce the amount of computations and storage necessary to produce forecasts of capacity requirements. This composition introduces a network usage pattern model based on decomposition by information transfer and verifies its application in real-life voice-data networks. Complex systems can be modeled and decomposed into sub-systems by observing the interactions among their …

Lightweight Composites For Modular Panelized Construction, Amol S. Vaidya

All ETDs from UAB

Rapid advances in construction materials technology have enabled civil engineers to achieve impressive gains in the safety, economy, and functionality of structures built to serve the common needs of society. Modular building systems is a fast-growing modern, form of construction gaining recognition for its increased efficiency and ability to apply modern technology to the needs of the market place. In the modular construction technique, a single structural panel can perform a number of functions such as providing thermal insulation, vibration damping, and structural strength. These multifunctional panels can be prefabricated in a manufacturing facility and then transferred to the construction …

Design Of Highway Overhead Cantilever-Type Sign Support Structures For Fatigue Loads, Ian Edward Hosch

All ETDs from UAB

The 2001 edition of the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals has been revised in its entirety through a major research project conducted under the auspices of the National Cooperative Highway Research Program (NCHRP 17-10). A major part of the revision included updated provisions and criteria for extreme wind loads and new provisions and criteria on fatigue design. These provisions differ considerably from those in previous editions of the specifications, and have remained relatively unchanged in the 2009 edition. The impact of the fatigue criteria …

Radiative Transfer Theory Applied To Ocean Bottom Modeling, Lisa M. Zurk, Jorge Quijano

Electrical and Computer Engineering Faculty Publications and Presentations

Research on the propagation of acoustic waves in the ocean bottom sediment is of interest for active sonar applications such as target detection and remote sensing. The interaction of acoustic energy with the sea floor sublayers is usually modeled with techniques based on the full solution of the wave equation, which sometimes leads to mathematically intractable problems. An alternative way to model wave propagation in layered media containing random scatterers is the radiative transfer RT formulation, which is a well established technique in the electromagnetics community and is based on the principle of conservation of energy. In this paper, the …

Opto-Vlsi-Based Tunable Single-Mode Fiber Laser, Feng Xiao, Kamal Alameh, Yong-Tak Lee

Research outputs pre 2011

A new tunable fiber ring laser structure employing an Opto-VLSI processor and an erbium-doped fiber amplifier (EDFA) is reported. The Opto-VLSI processor is able to dynamically select and couple a waveband from the gain spectrum of the EDFA into a fiber ring, leading to a narrow-linewidth high-quality tunable laser output. Experimental results demonstrate a tunable fiber laser of linewidth 0.05 nm and centre wavelength tuned over the C-band with a 0.05nm step. The measured side mode suppression ratio (SMSR) is greater than 35 dB and the laser output power uniformity is better than 0.25 dB. The laser output is very …

Tunable Multi-Wavelength Fiber Lasers Based On An Opto-Vlsi Processor And Optical Amplifiers, Feng Xiao, Kamal Alameh, Yong Lee

Research outputs pre 2011

A multi-wavelength tunable fiber laser based on the use of an Opto-VLSI processor in conjunction with different optical amplifiers is proposed and experimentally demonstrated. The Opto-VLSI processor can simultaneously select any part of the gain spectrum from each optical amplifier into its associated fiber ring, leading to a multiport tunable fiber laser source. We experimentally demonstrate a 3-port tunable fiber laser source, where each output wavelength of each port can independently be tuned within the C-band with a wavelength step of about 0.05nm. Experimental results demonstrate a laser linewidth as narrow as 0.05 nm and an optical side-mode-suppression-ratio (SMSR) of …

Tunable Photonic Microwave Filters Based On Opto-Vlsi Processors, Feng Xiao, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

A tunable photonic microwave filter structure utilizing an opto-very-large scale integration (opto-VLSI) processor is proposed and experimentally demonstrated. The opto-VLSI processor slices a radio-frequency (RF)-modulated wideband light source into wavebands of arbitrary weights and incremental delay times to realize a tunable RF filter response. Experimental results demonstrate a tunable microwave filter that can simply be reconfigured with high flexibility via a software-driven opto-VLSI processor. Theoretical simulations are in good agreement with the experimental results.

Opto-Vlsi-Based Broadband True-Time Delay Generation For Phased Array Beamforming, Budi Juswardy, Feng Xiao, Kamal Alameh

Research outputs pre 2011

Electronically controlled phased-array antennas can adaptively scan radiated beams in three-dimensional space without mechanically moving parts. While most of the research on phased-array antennas has been focusing on broadband beam steering less attention has been devoted to null steering. Broadband null steering requires a beamformer that can generate variable and frequency independent true time-delays (TTD). In this paper we propose and demonstrate the concept of an Opto-VLSI-based tunable true-time delay generation unit for adaptive null steering in phased array antennas, where arbitrary single or multiple true-time delays can simultaneously be synthesized. Simulated azimuth gain patterns for a 4- element antenna …

Photonic True-Time Delay Unit For Broadband Adaptive Nulling In Antenna Arrays, Budi Juswardy, Feng Xiao, Kamal Alameh

Research outputs pre 2011

This paper describes an opto-VLSI-based tunable true-time delay generation unit used for adaptive null steering in phased array antennas. Arbitrary single or multiple true-time delays can simultaneously be synthesized for each antenna element to generate multiple broadband nulls. Simulated azimuth gain patterns for a 4-elements antenna arrays are presented. Experimental results, which demonstrate the principle of the true-time delay unit are also presented.

Opto-Vlsi-Based Photonic True-Time Delay Architecture For Broadband Adaptive Nulling In Phased Array Antennas, Budi Juswardy, Feng Xiao, Kamal Alameh

Research outputs pre 2011

This paper proposes a novel Opto-VLSI-based tunable true-time delay generation unit for adaptively steering the nulls of microwave phased array antennas. Arbitrary single or multiple true-time delays can simultaneously be synthesized for each antenna element by slicing an RFmodulated broadband optical source and routing specific sliced wavebands through an Opto-VLSI processor to a high-dispersion fiber. Experimental results are presented, which demonstrate the principle of the true-time delay unit through the generation of 5 arbitrary true-time delays of up to 2.5 ns each.

Classical Search And Quantum Search Algorithms For Synthesis Of Quantum Circuits And Optimization Of Quantum Oracles, Sazzad Hossain

Dissertations and Theses

We observe an enormous increase in the computational power of digital computers. This was due to the revolution in manufacturing processes and controlling semiconductor structures on submicron scale, ultimately leading to the control of individual atoms. Eventually, the classical electric circuits encountered the barrier of quantum mechanics and its effects. However, the laws of quantum mechanics can be also used to produce computational devices that lead to extraordinary speed increases over classical computers. Thus quantum computing becomes a very promising and attractive research area. The Computer Aided Design for Quantum circuits becomes an essential ingredient for such emerging research which …

Quantum Inductive Learning And Quantum Logic Synthesis, Martin Lukac

Dissertations and Theses

Since Quantum Computer is almost realizable on large scale and Quantum Technology is one of the main solutions to the Moore Limit, Quantum Logic Synthesis (QLS) has become a required theory and tool for designing Quantum Logic Circuits. However, despite its growth, there is no any unified aproach to QLS as Quantum Computing is still being discovered and novel applications are being identified.

The intent of this study is to experimentally explore principles of Quantum Logic Synthesis and its applications to Inductive Machine Learning. Based on algorithmic approach, I first design a Genetic Algorithm for Quantum Logic Synthesis that is …

The Bundle Dispersion Of Swnt On Interaction With P-Terphenyl, Theresa Hedderman, Anika Mostaert, Anne Shanahan, Hugh Byrne

Articles

This paper investigates the interaction and bundle dispersion of single walled carbon nanotubes (SWNT) produced by arc discharge and by the high pressure decomposition of carbon monoxide, often referred to as the HiPco method, in the presence of the molecule p-terphenyl. The study will show that the extent of SWNT bundle dispersion and the degree of interaction with p-terphenyl is related to the level of purity of the SWNT sample. This study compares the bundle dispersion and interaction of SWNT with p-terphenyl in their as produced state and after purification. A number of spectroscopic and microscopic techniques are used to …

Preparation, Characterization Of Nipam And Nipam/Bam Copolymer Nanoparticles And Their Acute Toxicity Testing Using An Aquatic Test Battery, Pratap Naha, Alan Casey, Tiziana Tenuta, Iseult Lynch, Kenneth Dawson, Hugh Byrne, Maria Davoren

Articles

Poly N-isopropylacrylamide and N-isopropylacrylamide / N-tert-butylacrylamide copolymer nanoparticles of 50 to 70 nm were prepared by free radical polymerisation. The particle sizes of the copolymer nanoparticles were measured in the test media MilliQ water, Algae Media, Daphnia Media and Microtox Diluent as a function of temperature. Whereas in MilliQ water the particle size was seen to decrease above the lower critical solution temperature of the thermoresponsive polymer, in the test media it was seen to increase significantly, indicative of aggregation. At the temperatures employed for the ecotoxicological studies all particles, with the exception of the 50:50copolymer existed as nanoparticles, however. …

Titanium Dioxide Nanoparticles Induce Oxidative Stress And Dna-Adduct Formation But Not Dna-Breakage In Human Lung Cells, Kunal Bhattacharya, Maria Davoren, Jens Boertz, Roel P.F. Schins, Eik Hoffmann, Elke Dopp

Articles

Titanium dioxide (TiO2), also known as titanium (IV) oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP) by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity) and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ < 100 nm) using several parameters such as cyto- and genotoxicity, DNA-adduct formation and generation of free radicals following its uptake by human lung cells in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ < 100 nm) were used. The results of this study showed that both types of NP were located in the cytosol near the nucleus. No particles were found inside the nucleus, in mitochondria or ribosomes. Human lung fibroblasts (IMR-90) were more sensitive regarding cyto- and genotoxic effects caused by the NP than human bronchial epithelial cells (BEAS-2B). In contrast to hematite NP, TiO2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS) was measured acellularly (without any photocatalytic activity) as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG) was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage) and required reducing conditions for radical formation.

Providing Academic Leadership Through The Role Of Senior Lecturer 1 (Teaching) Using The Theme Of 'Sustainable Energy' As An Example, Jim Mcgovern

Articles

An academic leader should lead in their particular area and should love what they are doing. An example of leadership in the area of 'sustainable energy use' is presented that involves leading through identifying and participating in the development of emerging technologies. Excellent academic leadership can be provided by a Senior Lecturer through active research, incorporating the latest developments in student-centred learning in their work and providing example and encouragement for colleagues and learners.

The Effect Of Air Preheating In A Biomass Cfb Gasifier Using Aspen Plus Simulation, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

In the context of climate change, increasing efficiency and energy security, biomass gasification is likely to play an important role in energy production. Atmospheric circulating fluidised bed (CFB) technology was selected for the current study. The primary objective of this research is to develop a computer simulation model of a CFB biomass gasifier that can accurately predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus (Advanced System for Process ENgineering Plus). The model is based on Gibbs free energy minimisation. The restricted equilibrium method was used to calibrate the model against experimental data. This …

Regeneration Of Damaged Growth Plate Using Igf-I Plasmid-Releasing Porous Plga Scaffolds, Nirmal Ravi

University of Kentucky Doctoral Dissertations

Growth plate injuries account for 15-30% of long bone fractures in children. About 10% of these result in significant growth disturbances due to formation of a boney bar. If not treated correctly, this can lead to life-lasting consequences of limb length inequalities and angular deformities. Current treatments for growth plate injuries include removal of boney bar and insertion of fat, silicone, bone cement, etc.. This treatment y is inadequate, leaving almost half of these patients with continued deformities. This dissertation reports characterization of a DNA–containing porous poly(lactic-co-glycolic acid) (PLGA) scaffold system, chondrogenesis using insulin-like growth factor I (IGF-I) plasmid-releasing scaffolds …

Production Sequencing And Stability Analysis Of A Just-In-Time System With Sequence Dependent Setups, John Thomas Henninger

University of Kentucky Doctoral Dissertations

Just-In-Time (JIT) production systems is a popular area for researchers but real-world issues such as sequence dependent setups are often overlooked. This research investigates an approach for determining stability and an approach for mixed product sequencing in production systems with sequence dependent setups and buffer thresholds which signal replenishment of a given buffer. Production systems in this research operate under JIT pull production principles by producing only when demand exists and idle when no demand exists.

In the first approach, an iterative method is presented to determine stability for a multi-product production system that operates with replenishment signals and may …

3d Reconstruction Using Multi-View Imaging System, Conglin Huang

University of Kentucky Master's Theses

This thesis presents a new system that reconstructs the 3D representation of dental casts. To maintain the integrity of the 3D representation, a standard model is built to cover the blind spots that the camera cannot reach. The standard model is obtained by scanning a real human mouth model with a laser scanner. Then the model is simplified by an algorithm which is based on iterative contraction of vertex pairs. The simplified standard model uses a local parametrization method to obtain the curvature information. The system uses a digital camera and a square tube mirror in front of the camera …

Electrical And Mechanical Properties Of Mwcnt Filled Conductive Adhesives On Lead Free Surface Finished Pcb's., Keerthi Varma Mantena

University of Kentucky Master's Theses

Electrically conductive adhesives (ECA) are an alternative to tin/lead solders for attaching Surface Mount Devices (SMD) in electronic assemblies. ECAs are mixtures of a polymer binder (for adhesion) and conductive filler (for electrical conductivity). They bring more conductivity, higher strength, less weight and longer durability than metal alloys. ECAs can offer numerous advantages such as fewer processing steps, lower processing temperature and fine pitch capability. Multi walled carbon nanotubes (MWCNT) were used as conductive fillers in this research because of their novel electronic and mechanical properties.

The high aspect ratio of the nanotubes makes it possible to percolate at low …

Mpi Within A Gpu, Bobby Dalton Young

University of Kentucky Master's Theses

GPUs offer high-performance floating-point computation at commodity prices, but their usage is hindered by programming models which expose the user to irregularities in the current shared-memory environments and require learning new interfaces and semantics.

This thesis will demonstrate that the message-passing paradigm can be conceptually cleaner than the current data-parallel models for programming GPUs because it can hide the quirks of current GPU shared-memory environments, as well as GPU-specific features, behind a well-established and well-understood interface. This will be shown by demonstrating a proof-of-concept MPI implementation which provides cleaner, simpler code with a reasonable performance cost. This thesis will also …

Collective Communication And Barrier Synchronization On Nvidia Cuda Gpu, Diego Alejandro Rivera-Polanco

University of Kentucky Master's Theses

GPUs (Graphics Processing Units) employ a multi-threaded execution model using multiple SIMD cores. Compared to use of a single SIMD engine, this architecture can scale to more processing elements. However, GPUs sacrifice the timing properties which made barrier synchronization implicit and collective communication operations fast.

This thesis demonstrates efficient methods by which these aggregate functions can be implemented using unmodified NVIDIA CUDA GPUs. Although NVIDIA's highest “compute capability" GPUs provide atomic memory functions, they have order N execution time. In contrast, the methods proposed here take advantage of basic properties of the GPU architecture to make implementations that are both …

Design And Analysis Of Nano-Gap Enhanced Surface Plasmon Resonance Sensors, Phillip Donald Keathley

University of Kentucky Master's Theses

Surface plasmon resonance (SPR) sensors are advantageous to other techniques of sensing chemical binding, offering quantitative, real-time, label-free results. Previous work has demonstrated the effectiveness of using dual-mode SPR sensors to differentiate between surface and background effects, making the sensors more robust to dynamic environments. This work demonstrates a technique that improves upon a previously optimized planar film dual-mode SPR sensor’s LOD by introducing a periodic array of subwavelength nano-gaps throughout the plasmon supporting material. First, general figures of merit for a sensor having an arbitrary number of modes are studied. Next, the mode effective index dispersion and magnetic field …

Tem Study Of Niobium Surfaces Treated By Different Polishing Techniques, A.T. Wu, D. Gu, Helmut Baumgart

Electrical & Computer Engineering Faculty Publications

TEM cross-section observation on Nb surfaces has been a challenge to our superconducting radio frequency (SRF) community due to the highly reactive nature of Nb. Although it was demonstrated in an early attempt1 that under a suitable sample preparation procedure reasonably clear cross-section images of Nb could be obtained, to the best of our knowledge good atomically resolved images had never been obtained. In this report, it is shown that by modifying the sample preparation procedure adopted in reference 1 it is possible to obtain good cross-section images of Nb surfaces with atomic resolution routinely. Surface atomic structures of Nb …

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.