Engineering Commons^™

Quantification Of Thoracic Aorta Blood Flow By Magnetic Resonance Imaging During Supine Cycling Exercise Of Increasing Intensity, Laura M. Ellwein, John F. Ladisa, Stacy Leibham, Sheila M. Schindler-Ivens, Margaret M. Samyn

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Online State Of Charge And Electrical Impedance Estimation For Multicell Lithium-Ion Batteries, Taesic Kim, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a hybrid battery model-based high-fidelity state of charge (SOC) and electrical impedance estimation method for multicell lithium-ion batteries. The hybrid battery model consists of an enhanced Coulomb counting algorithm for SOC estimation and an electrical circuit battery model. A particle swarm optimization (PSO)-based online parameter identification algorithm is designed to estimate the electrical parameters of the cells sequentially. An SOC compensator is designed to correct the errors of the enhanced Coulomb counting SOC estimations for the cells sequentially. This leads to an accurate, robust online SOC estimation for individual cells of a battery pack. The proposed method …

Synthesis Of Mn3o4-Encapsulated Graphene Sheet Nanocomposites Via A Facile, Fast Microwave Hydrothermal Method And Their Supercapacitive Behaviour, Li Li, Kuok Hau Seng, Zhixin Chen, Hua-Kun Liu, Ivan P. Nevirkovets, Zaiping Guo

Faculty of Engineering and Information Sciences - Papers: Part A

Well-crystallized Mn3O4-anchored reduced graphene oxide (rGO) nanocomposites have been successfully synthesized via a facile, effective, energy-saving, and scalable microwave hydrothermal technique for potential application as supercapacitor material. Integrating these nanostructures resulted in a strong synergistic effect between the two materials, consequently leading to a hybrid composite with higher specific capacitance compared to the bare Mn3O4 nanoparticles. The results from different sorts of characterization indicate that the Mn3O4 particles were deposited and anchored on graphene sheets. The capacitance value of the rGO(31.6%)–Mn3O4 nanocomposite reached 153 F/g, much higher than that of the bare Mn3O4 (87 F/g) at a scan rate of …

Separation Control On High Lift Low-Pressure Turbine Airfoils Using Pulsed Vortex Generator Jets, Ralph J. Volino, Mounir B. Ibrahim

Mechanical Engineering Faculty Publications

Boundary layer separation control has been studied using vortex generator jets (VGJs) on a very high lift, low-pressure turbine airfoil. Experiments were done under low (0.6%) freestream turbulence conditions on a linear cascade in a low speed wind tunnel. Pressure surveys on the airfoil surface and downstream total pressure loss surveys were documented. Instantaneous velocity profile measurements were acquired in the suction surface boundary layer. Cases were considered at Reynolds numbers (based on the suction surface length and the nominal exit velocity from the cascade) of 25000 and 50000. Jet pulsing frequency and duty cycle were varied. In cases without …

An Investigation Of Security Challenges In Cognitive Radio Networks, Deepraj S. Vernekar

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

The recent advances in wireless communication have led to the problem of growing spectrum scarcity. The available wireless spectrum has become scarcer due to increasing spectrum demand for new wireless applications. The large portion of the allocated spectrum is sporadically used leading to underutilization of significant amount of spectrum. To improve the spectrum efficiency, the idea of cognitive radio technology was introduced. This concept of cognitive radio provides a promising solution for the spectrum scarcity issues in wireless networks. Meanwhile, the security issues of cognitive radio have received more attentions recently since the inherent properties of CR networks would pose …

An Ultra-Low Power Communication Protocol For A Self-Powered Wireless Sensor Based Animal Monitoring System, Tao Ma

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

To prevent and control the outbreak of contagious animal disease, many countries have developed animal identification and tracking systems. However, the current animal identification and tracking system, which is based on passive RFID technology, has many limitations such as the short communication range and incapability of automatically monitoring the animal. To overcome these limitations, our Advanced Telecommunications Engineering Laboratory (TEL) in Department of Computer and Electronics Engineering (CEEN), University of Nebraska-Lincoln took the mission of developing a more advanced monitoring system for animal identification and tracking. This dissertation work as a part of this mission was focusing on developing an …

Online Nonintrusive Condition Monitoring And Fault Detection For Wind Turbines, Xiang Gong

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The goal of this dissertation research is to develop online nonintrusive condition monitoring and fault detection methods for wind turbine generators (WTGs). The proposed methods use only the current measurements that have already been used by the control and protection systems of WTGs; no additional sensors or data acquisition devices are needed. Current-based condition monitoring and fault detection techniques have great economic benefits and the potential to be adopted by the wind energy industry. However, there are challenges in using current measurements for wind turbine condition monitoring and fault detection. First, it is a challenge to extract WTG fault signatures …

Suppressing Leakage By Localized Doping In Si Nanotransistor Channels, Jesse Maassen, Hong Guo

Birck and NCN Publications

By first principles atomistic analysis we demonstrate how controlled localized doping distributions in nanoscale Si transistors can suppress leakage currents. We consider dopants (B and P atoms) to be randomly confined to a approximate to 1 nmwidth doping region in the channel. If this region is located away from the electrodes, roughly 20% of the channel length L, the tunneling leakage is reduced 2x compared to the case of uniform doping and shows little variation. Oppositely, we find the leakage current increases by orders of magnitude and may result in large device variability. We calculate the maximum and minimum conductance …

Real Time X-Ray Studies During Nanostructure Formation On Silicon Via Low Energy Ion Beam Irradiation Using Ultrathin Iron Films, Osman El-Atwani, Anastassiya Suslova, Alexander Demasi, Sean Gonderman, Justin Fowler, Mohamad El-Atwani, Karl Ludwig, Jean Paul Allain

Birck and NCN Publications

Real time grazing incidence small angle x-ray scattering and x-ray fluorescence (XRF) are used to elucidate nanodot formation on silicon surfaces during low energy ion beam irradiation of ultrathin iron-coated silicon substrates. Four surface modification stages were identified: (1) surface roughening due to film erosion, (2) surface smoothing and silicon-iron mixing, (3) structure formation, and (4) structure smoothing. The results conclude that 2.5 x 10(15) iron atoms in a 50 nm depth triggers surface nanopatterning with a correlated nanodots distance of 25 nm. Moreover, there is a wide window in time where the surface can have correlated nanostructures even after …

Theranostic Oxygen Delivery Using Ultrasound And Microbubbles, James J. Kwan, Mehmet Kaya, Mark A. Borden, Paul A. Dayton

Biomedical Engineering and Sciences Faculty Publications

Means to overcome tumor hypoxia have been the subject of clinical investigations since the 1960’s; however these studies have yet to find a treatment which is widely accepted. It has been known for nearly a century that hypoxic cells are more resistant to radiotherapy than aerobic cells, and tumor hypoxia is a major factor leading to the resistance of tumors to radiation treatment as well as several cytotoxic agents. In this manuscript, the application of ultrasound combined with oxygen-carrier microbubbles is demonstrated as a method to locally increase dissolved oxygen. Microbubbles can also be imaged by ultrasound, thus providing the …

Mechanical Properties And Tensile Failure Analysis Of Novel Bio-Absorbable Mg-Zn-Cu And Mg-Zn-Se Alloys For Endovascular Applications, Dharam Persaud, Noah Budiansky, Anthony J. Mcgoron

Department of Biomedical Engineering Faculty Publications

In this paper, the mechanical properties and tensile failure mechanism of two novel bio-absorbable as-cast Mg-Zn-Se and Mg-Zn-Cu alloys for endovascular medical applications are characterized. Alloys were manufactured using an ARC melting process and tested as-cast with compositions of Mg-Zn-Se and Mg-Zn-Cu, being 98/1/1 wt.% respectively. Nanoindentation testing conducted at room temperature was used to characterize the elastic modulus (E) and surface hardness (H) for both the bare alloys and the air formed oxide layer. As compared to currently available shape memory alloys and degradable as-cast alloys, these experimental alloys possess superior as-cast mechanical properties that can increase their biocompatibility, …

Comparison Of 4d Phase-Contrast Mri Flow Measurements To Computational Fluid Dynamics Simulations Of Cerebrospinal Fluid Motion In The Cervical Spine, Theresia Yiallourou, Jan Robert Kroger, Nikolaos Stergiopulos, David Maintz, Bryn A. Martin, Alexander C. Bunck

Mechanical Engineering Faculty Research

Cerebrospinal fluid (CSF) dynamics in the cervical spinal subarachnoid space (SSS) have been thought to be important to help diagnose and assess craniospinal disorders such as Chiari I malformation (CM). In this study we obtained time-resolved three directional velocity encoded phase-contrast MRI (4D PC MRI) in three healthy volunteers and four CM patients and compared the 4D PC MRI measurements to subject-specific 3D computational fluid dynamics (CFD) simulations. The CFD simulations considered the geometry to be rigid-walled and did not include small anatomical structures such as nerve roots, denticulate ligaments and arachnoid trabeculae. Results were compared at nine axial planes …

Universal Programmable Quantum Circuit Schemes To Emulate An Operator, Anmer Daskin, Ananth Grama, Giorgos Kollias, Sabre Kais

Birck and NCN Publications

Unlike fixed designs, programmable circuit designs support an infinite number of operators. The functionality of a programmable circuit can be altered by simply changing the angle values of the rotation gates in the circuit. Here, we present a new quantum circuit design technique resulting in two general programmable circuit schemes. The circuit schemes can be used to simulate any given operator by setting the angle values in the circuit. This provides a fixed circuit design whose angles are determined from the elements of the given matrix-which can be non-unitary-in an efficient way. We also give both the classical and quantum …

Information Technology News, Georgia Southern University

Information Technology News (2012-2023)

• The Department of Information Technology Joins Linux Professional Institute’s Approved Academic Partner Program

Stress And Strain Adaptation In Load-Dependent Remodeling Of The Embryonic Left Ventricle, Christine Buffinton

Faculty Journal Articles

Altered pressure in the developing left ventricle (LV) results in altered morphology and tissue material properties. Mechanical stress and strain may play a role in the regulating process. This study showed that confocal microscopy, three-dimensional reconstruction, and finite element analysis can provide a detailed model of stress and strain in the trabeculated embryonic heart. The method was used to test the hypothesis that end-diastolic strains are normalized after altered loading of the LV during the stages of trabecular compaction and chamber formation. Stage-29 chick LVs subjected to pressure overload and underload at stage 21 were reconstructed with full trabecular morphology …

The Effect Of Native Oxide On Ion-Sputtering-Induced Nanostructure Formation On Gasb Surfaces, Osman El-Atwani, Jean Paul Allain, Anastassiya Suslova

Birck and NCN Publications

We have investigated the influence of native oxides on ion-sputtering-induced nanostructure formation on GaSb using in situ low energy ion scattering spectroscopy (LEISS) and X-ray photoelectron spectroscopy (XPS). Comparing an oxygen-free sample with a native oxide sample, LEISS and XPS reveal the effect of oxygen in generating higher surface Ga fractions during early stages (fluences of 1 x 10(15)-1 x 10(16) cm(-2)) of low energy (< 100 eV) Ar+ irradiation. Enhanced surface Ga and Ga2O3 fractions were also observed on "oxide free" samples exposed to air following irradiation. The results suggest preferential Ga oxidation and segregation on the top of the amorphous layer if oxygen is present on the surface. In addition, the native oxide also increases the fluence threshold for nanopatterning of GaSb surfaces by almost a factor of four during low energy irradiation. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4772980]

A Smartphone Design Approach To User Communication Interface For Administering Storage System Network, Weider Yu, Xiao Su, Jason Hansen

Faculty Publications

This paper investigates the feasibility and potential of using a mobile smartphone as a user administration control for storage system network. It includes the design and implementation of a mobile smartphone software system that can be used to perform system administration activities on the storage system without the need of using a laptop or desktop system. In the paper the design of some effective metaphors to present the storage system on the limited display area of a mobile smartphone device and the set of system features chosen for implementation are presented. Current storage system administration is limited to using storage …

Automatic Object Recognition And Registration Of Dynamic Heavy Equipment Using A Hybrid Ladar System, Mengmeng Gai

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

It has been a challenging subject to recognize dynamic objects from a scattered work environment because large and complex 3D site data obtained by a laser scanner makes it difficult to process itself in real or near real time. This thesis introduces a model-based automatic object recognition and registration framework, Projection-Recognition-Projection (PRP), to assist heavy equipment operators in rapidly perceiving 3D working environment at dynamic construction sites. In this study, a digital camera and a hybrid laser scanner were used to rapidly recognize and register dynamic target objects in a 3D space by separating target object’s point cloud data from …

An Investigation Of The Optical Properties Of Disordered Silicon Nanowire Mats, Hua Bao, Weixia Zhang, Liangliang Chen, Haoxiang Huang, Chen Yang, Xiulin Ruan

Birck and NCN Publications

Optical reflectance spectra of three disordered silicon nanowire mats with average diameters of 40, 60, and 80 nm are investigated both experimentally and theoretically. The total hemispherical reflectance spectra from 200 to 1600 nm wavelength are first measured. All three samples exhibit reflectance about 15% to 20% within the ultraviolet band. As the wavelength becomes longer, the reflectance will first increase to around 50% and then decrease to below 20%. Such reflectance spectra are attributed to the combined effect of silicon dielectric function, the nanowire geometry, and the volume fraction of the mats. An analytical method based on Mie scattering …

High Performance Low Temperature Solid Oxide Fuel Cells With Novel Electrode Architecture, Yu Chen, Qian Liu, Zhibin Yang, Fanglin Chen, Minfang Han

Faculty Publications

In this study, we have fabricated high performance low temperature solid oxide fuel cells (LT-SOFCs) with both acicular anodes and cathodes with thin Gd-doped ceria (GDC) electrolyte film. The acicular Ni-Gd_0.1Ce_0.9O_2−δ (Ni-GDC) anode was prepared using freeze drying tape casting, while the hierarchically porous cathode with nano-size Sm_0.5Sr_0.5CoO₃ (SSC) particles covering an acicular GDC skeleton was prepared by a combination of freeze drying tape casting and self-rising approaches. The acicular electrodes with 5–200 μm pores/channels enhance mass transport, while SSC particles of about 50 nm in the cathode promote …

Spatiotemporal Capacity Management For The Last Level Caches Of Chip Multiprocessors, Dongyuan Zhan

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Judicious management of on-chip last-level caches (LLC) is critical to alleviating the memory wall of chip multiprocessors (CMP). Although there already exist many LLC management proposals, belonging to either the spatial or temporal dimension, they fail to capture and utilize the inherent interplays between the two dimensions in capacity management. Therefore, this dissertation is targeted at exploring and exploiting the spatiotemporal interactions in LLC capacity management to improve CMPs' performance. Based on this general idea, we address four specific research problems in the dissertation.

For the private LLC organization, prior-art proposals can improve the efficacy of inter-core cooperative caching at …

2011 Nanoelectronic Devices For Defense & Security (Nano-Dds) Conference: A Request For Funding To Support Attendee Participation. To Be Held Aug. 29 To Sept 1, 2011 At Nyu-Poly, Carl P. Tripp

University of Maine Office of Research Administration: Grant Reports

Intellectual Merit: The Nanoelectronic Devices for Defense & Security (NANO-DDS) Conference is a bi-annual science and technology event which has been organized for the purpose of reviewing the evolving research and development (R&D) activities in the arena of nanoelectronic devices that have direct relevance to critical capability needs for national defense & security in the future. The charter of this special conference is to unify and focus the very broad array of nanoelectronic and supporting nanotechnology activities that are currently engaged in reaching the long expected applications payoffs in core defense and security related areas such as sensing, data processing, …

A Building Energy Efficiency Optimization Method By Evaluating The Effective Thermal Zones Occupancy, Anna Laura Pisello, Michael Bobker, Franco Cotana

Publications and Research

Building energy efficiency is strongly linked to the operations and control systems, together with the integrated performance of passive and active systems. In new high quality buildings in particular, where these two latter aspects have been already implemented at the design stage, users’ perspective, obtained through post-occupancy assessment, has to be considered to reduce whole energy requirement during service life. This research presents an innovative and low-cost methodology to reduce buildings’ energy requirements through post-occupancy assessment and optimization of energy operations using effective users’ attitudes and requirements as feedback. As a meaningful example, the proposed method is applied to a …

Effects Of Crossflow Velocity And Transmembrane Pressure On Microfiltration Of Oil-In-Water Emulsions, Nikolai V. Priezjev, Tohid Darvishzadeh

Mechanical and Materials Engineering Faculty Publications

This study addresses the issue of oil removal from water using hydrophilic porous membranes. The effective separation of oil-in-water dispersions involves high flux of water through the membrane and, at the same time, high rejection rate of the oil phase. The effects of transmembrane pressure and crossflow velocity on rejection of oil droplets and thin oil films by pores of different cross-section are investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure, which is required for the oil droplet entry into a circular pore of a given surface hydrophilicity, agrees …

Analytical Representations For Frequency Dependences Of Microwave Permeability, Konstantin N. Rozanov, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic materials applied to solve various EMC and EMI problems require adequate analytical description of their RF and microwave material parameters. This is necessary for numerical optimization of wideband electromagnetic performance of devices incorporating these materials. The paper discusses the shape of frequency dependences of microwave permeability in homogeneous materials and composites. The Lorentzian frequency dispersion law is shown to allow for rather accurate description of all types of magnetic loss peaks, including those related to the ferromagnetic resonance and the effect of eddy currents. To model wideband electromagnetic performance of composites, mixing laws are typically used. The problem is …

Electromagnetic Properties Of Metal Granular Composite Materials For Emc Applications, Takanori Tsutaoka, Aiko Tsurunaga, Teruhiro Kasagi, Kenichi Hatakeyama, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic properties of copper and Fe₅₅Ni₄₅alloy (Permalloy) composite materials have been studied by measuring the relative complex permeability (µ_r = µ_r’– jµ_r”), and permittivity (Σ_r = Σ_r’– jΣ_r”) spectra over the microwave range, as well as the a.c. electrical conductivity σac spectra. The variation of σ_ac and Σ_r with particle content shows the insulator-metal transition due to the percolation effect. The effective cluster model can be applied to the percolation effect in permittivity. The permeability spectra in Permalloy composites, which contain the percolated particles, …

Alternative Aefie-Efie Method For Broadband Cem Modeling, Jia Liu, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

It is well known that the electric field integral equation (EFIE) has the low frequency breakdown problem while the Augmented electric field integral equation (AEFIE) method has the high frequency breakdown issue. To obtain a unified method that works for both low and high frequencies without manual switching of methods, a novel and simple method is proposed in this paper. It uses AEFIE and EFIE to compensate each other iteratively in all frequency regimes to guarantee the accuracy of the solution. As a result, it effectively extends AEFIE to the high frequency regime and extends EFIE to the low frequency …

Method For Removing Co2 From Coal-Fired Power Plant Flue Gas Using Ammonia As The Scrubbing Solution, With A Chemical Additive For Reducing Nh3 Losses, Coupled With A Membrane For Concentrating The Co2 Stream To The Gas Stripper, Kunlei Liu, James K. Neathery, Joseph E. Remias, Xiansen Li

Center for Applied Energy Research Faculty Patents

A method for removing and capturing carbon dioxide from a fluid stream includes the steps of exposing the fluid stream to an aqueous scrubbing solution that removes and holds carbon dioxide from the fluid stream, passing the aqueous scrubbing solution through a membrane in order to separate excess water from the scrubbing solution and increase the concentration of carbon dioxide in the scrubbing solution, heating the scrubbing solution having an increased concentration of carbon dioxide so as to release carbon dioxide gas and recycling the scrubbing solution. A carbon dioxide capture apparatus includes a carbon dioxide scrubber, a membrane downstream …

Characterization Of Wave Physics Using The Rigorous Helmholtz Decomposition Based On The Surface Integral Equation, Xiaoyan Y.Z. Xiong, Wei E.I. Sha, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Helmholtz decomposition (HD) is a fundamental tool of vector calculus and plays an important role in electromagnetics. In this work, arbitrary vector field defined on the open or closed surface is decomposed into the sum of an irrotational (curl-free) vector field and a solenoidal (divergence-free) vector field by using the surface integral equation method. Unlike the popular loop-tree decomposition that is only a quasi-HD suitable for the circuit physics in the low frequency regime, the HD developed in this paper is rigorous and can capture both circuit and wave physics from very low frequency to high frequency regimes. The work …

The Far Field Transformation Using The Iterative Srm Based On The Phaseless Data, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional equivalent source reconstruction methods (SRM) require both phase and amplitude information of the field data. However, there are situations where the phase information is not easy to obtain. Hence, developing novel SRM based on phaseless data is necessary. In this paper, a novel iterative SRM based on two sets of measured phaseless data is presented. It can reproduce the 3D radiation pattern with very good accuracy. Integral equation (IE) is employed to build reconstruct equivalent source. Combined field IE (CFIE) is also employed to obtain more physical current distribution. © 2012 IEEE.