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Electrical and Computer Engineering Commons

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Full-Text Articles in Electrical and Computer Engineering

Solid-State Transformers For Interfacing Solar Panels To The Power Grid: An Optimum Design Methodology Of A High Frequency Transformer For Dc-Dc Converter Applications, Kenny George Jan 2016

Solid-State Transformers For Interfacing Solar Panels To The Power Grid: An Optimum Design Methodology Of A High Frequency Transformer For Dc-Dc Converter Applications, Kenny George

Inquiry: The University of Arkansas Undergraduate Research Journal

Nowadays the use of power electronic interfaces to integrate distributed generation with the power grid is becoming relevant due to the increased penetration of renewable energy sources like solar, and the continued interest to move to a smarter and more robust electric grid. Those interfaces, which also provide a voltage step-up or step-down function, are of particular interest because renewable energy sources do not always have voltages compatible with the connecting grid. Among them, the so-called “power electronic transformer” or “solid-state transformer” (SST) is the focus of significant research. Advantages such as bidirectional power flow, improved system control, reduced size, …


Interface Property Of Collagen And Hydroxyapatite In Bone And Developing Bioinspired Materials, Clint Paul Jan 2015

Interface Property Of Collagen And Hydroxyapatite In Bone And Developing Bioinspired Materials, Clint Paul

Inquiry: The University of Arkansas Undergraduate Research Journal

Bone at the nanoscale consists of type I collagen and hydroxyapatite (HAP). Type I collagen and HAP [Ca10(PO4)6(OH)2] are responsible for most of the structural integrity of bone. Collagen fibrils contain HAP platelets of varying size dispersed between the collagen. We investigate heterotrimeric collagen interaction with HAP using Steering Molecular Dynamics to obtain the force-displacement relation as the collagen is undergoing shearing and peeling on the surface of HAP. Results indicate that the collagen requires 40% less force to separate form the HAP surface under peeling, when compared to shear loading conditions. In both shearing and peeling, the number of …


A New Design Method For Vanadium Redox Batteries In Renewable Energy Systems, Casey Gibson, Karla G. Morrissey Unversity Of Arkansas, Fayetteville Jan 2015

A New Design Method For Vanadium Redox Batteries In Renewable Energy Systems, Casey Gibson, Karla G. Morrissey Unversity Of Arkansas, Fayetteville

Inquiry: The University of Arkansas Undergraduate Research Journal

This study investigated the behavior of vanadium redox flow batteries (VRFBs), which are batteries capable of easily switching between charging and discharging modes, making them a suitable option for storing intermittent sources of alternative energies (solar, wind, etc). Since different sizes of the battery provide varying voltages, optimal parameters for a particular home are key for implementation. These parameters, specifically the cell and tank volumes of the battery that are capable of providing consistent on-load voltage, were determined using data from a 13 kW solar array and a medium-sized house. Charge/discharge current values were used to run a mathematical model …


Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow Jan 2007

Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow

Inquiry: The University of Arkansas Undergraduate Research Journal

Data logging capability of a previously developed self contained cough recorder using an accelerometer as the sensing element is improved by using a secure digital memory card for later retrieval on a computer. Firmware is developed to enhance the functionality of the cough recorder. Existing libraries are modified for increased write rates. Increased writing speed allows 8-bit sampling at rates exceeding 8kHz, allowing for detailed time and frequency domain analysis. Additional features have also been developed to enable easy management of recordings, such as a file system compatibility with Microsoft Windows., and unique file names for each recording.


Parameter Extraction Software For Silicon Carbide Schottky, Merged Pin Schottky And Pin Power Diode Models, Edgar Cilio Jan 2004

Parameter Extraction Software For Silicon Carbide Schottky, Merged Pin Schottky And Pin Power Diode Models, Edgar Cilio

Inquiry: The University of Arkansas Undergraduate Research Journal

A software program for on-state parameter extraction is presented for the realization of a high quality model for SiC Schottky, Merged PiN Schottky, and PiN Power diodes based on McNutt and Mantooth's Comprehensive SiC Diode model [ 1 ].


Investigation On How To Improve Latent Semantic Analysis Performance, Thao Doan Jan 2003

Investigation On How To Improve Latent Semantic Analysis Performance, Thao Doan

Inquiry: The University of Arkansas Undergraduate Research Journal

Latent Semantic Analysis (LSA) is a matching technique capable of recognizing the semantic relationships of data that ordinary techniques such as string matching cannot. This is especially valuable for data integration applications, like those of Acxiom, where data items are usually related by context, rather than in a literal match. Even though it has been shown that LSA is 30% more effective in finding and ranking relevant pieces of information than existing string-by-string matching techniques (Deerwester et al., 1990; Dumais, 1995), the performance of the LSA seems to be affected by the presence of shared words, or “noise”, in data. …


The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick Jan 2002

The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick

Inquiry: The University of Arkansas Undergraduate Research Journal

Perfluorocompounds (PFCs) are highly stable chemical compounds used in two integral steps of semiconductor manufacturing: chemical vapor deposition (CVD) chambers and etch chambers. Unfortunately, PFCs are also greenhouse gases linked to global warming. This, combined with their long atmospheric lifetimes gives them global warming potentials much higher than C02 the principal greenhouse gas. In a series of voluntary agreements with the United States and other national governments, the worldwide semiconductor industry has set a goal of reducing PFC emissions to 90% of their 1995 levels. To reach this goal, researchers have explored four main methods of reduction: substitution of PFCs, …


A Method Of Implementing The Interleaver In 3g Wireless Communication Systems For Randomization Of Burst Errors, Eric Duquette Jan 2001

A Method Of Implementing The Interleaver In 3g Wireless Communication Systems For Randomization Of Burst Errors, Eric Duquette

Inquiry: The University of Arkansas Undergraduate Research Journal

In less than a year or two, third generation ( 3G) wireless communication systems will be replacing the currently existing second generation (2G) wireless systems and be used worldwide. The 3G systems will have a higher data transfer capacity, which allows for simultaneous data, voice, and video transfer (e.g., multimedia applications) while most of 2G systems only allow for low-rate data and voice transfer. The wireless communications industry has set standards for 3G, which detail various operations of the technology. It should be noted that the 3G standards outline only the different operations and not the processes for the production …