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2005

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Articles 1381 - 1410 of 3074

Full-Text Articles in Engineering

Identification And Expansion Of Pancreatic Stem/Progenitor Cells., You-Qing Zhang, Marcie Kritzik, Nora Sarvetnick Apr 2005

Identification And Expansion Of Pancreatic Stem/Progenitor Cells., You-Qing Zhang, Marcie Kritzik, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Pancreatic islet transplantation represents an attractive approach for the treatment of diabetes. However, the limited availability of donor islets has largely hampered this approach. In this respect, the use of alternative sources of islets such as the ex vivo expansion and differentiation of functional endocrine cells for treating diabetes has become the major focus of diabetes research. Adult pancreatic stem cells /progenitor cells have yet to be recognized because limited markers exist for their identification. While the pancreas has the capacity to regenerate under certain circumstances, questions where adult pancreatic stem/progenitor cells are localized, how they are regulated, and even …


Development Of A Statistical Model For Process Control To Eliminate Sink Marks In Injection Molded Products, Kurt Frederick Hayden Apr 2005

Development Of A Statistical Model For Process Control To Eliminate Sink Marks In Injection Molded Products, Kurt Frederick Hayden

Masters Theses

Customer demands for high-quality, defect-free injection-molded products are ever increasing. In order to satisfy these quality requirements, much effort is spent monitoring and controlling variable data such as cycle time, part weight, and dimensions. Attribute defects such as sink or splay are often overlooked in the development of process control systems. However, customers reject products because of these attribute defects. Industrial control systems based upon process variables and product design variables can detect conditions that may result in the molding of products with attribute defects. The systems can then correct the process prior to the molding of these defective products. …


Effect Of Automation Management Strategies And Sensory Modalities As Applied To A Baggage Screening Task, Michelle Ann Leach Apr 2005

Effect Of Automation Management Strategies And Sensory Modalities As Applied To A Baggage Screening Task, Michelle Ann Leach

Master's Theses - Daytona Beach

Automation management strategies can assist the operator in coordinating activity in automated systems. Baggage screening is a domain in which automation and alarms can be studied in terms of signal detection theory. Baggage screening is vital to national security and should be completed in a time efficient manner without compromising accuracy. In the present study, the automation management strategies of management by consent (MBC) and management by exception (MBE) were crossed with alarm modalities of a visual (flashing) or an auditory alert which served as redundant cues in a baggage screening task. A control base line condition existed in which …


The Effect Of Level Of Automation And Operator-To-Vehicle Ratio On Operator Workload And Performance In Future Uav Systems, Ryan J. Wasson Apr 2005

The Effect Of Level Of Automation And Operator-To-Vehicle Ratio On Operator Workload And Performance In Future Uav Systems, Ryan J. Wasson

Master's Theses - Daytona Beach

The military intends to increase the number of UAVs in service while at the same time reducing the number of operators (Dixon, Wickens & Chang; 2004). To meet this demand, many of the current UAV operator functions will need to be automated. How automation is applied to modern systems is not fixed. Levels of automation exist along a continuum from fully manual to fully automatic. Two proposed levels of automation for future UAV systems are Management by Consent (MBC), where the operator selects the task to be executed, and Management by Exception (MBE), where the computer selects the task to …


A Computational Study Of Thermo-Fluid Dynamics Of Pulse Detonation Engines, Alberto Davila Urresti Apr 2005

A Computational Study Of Thermo-Fluid Dynamics Of Pulse Detonation Engines, Alberto Davila Urresti

Master's Theses - Daytona Beach

The purpose of this thesis is to use a transient Computational Fluid Dynamics computer code written in FORTRAN 90 for full reaction kinetics, to perform an analysis of the physical processes and chemical phenomena occurring on a single cycle of an ideal Pulse Detonation Engine (PDE) using a stoichiometric mixture of H2 and O2. A small zone of high pressure and temperature is used to initiate the detonation wave in the PDE. A simple case with no chemical reactions and the same PDE geometry and “computational spark” is also tested. The speed of the wave relative to …


Acuta Enews April 2005, Vol. 34, No. 4 Apr 2005

Acuta Enews April 2005, Vol. 34, No. 4

ACUTA Newsletters

ln This Issue

Nominate Now for ACUTA Ruth A. Michalecki Leadership Award

From the President .................................Tamara Closs, Georgetown Univ,

Tech Talk: Make Sure Your VolP Equipment Stays Cool ........................... Kevin Tanzillo, Dux PR

Web Tip: Listserv & Resource Library ....................... Aaron Fuehrer, ACUTA Computer Services Mgr.

To Wire or Not to Wire New Construction............... Geoff Tritsch, Compass Consulting lntl. lnc.

Caller lD Spoofing: Another Kind of identity Theft....... Corinne Hoch, Nuala Hallinan, Columbia Univ.

DC Update......................... Whitney Johnson, Retired, No. Michigan Univ.

Board Report............................... Carmine Piscopo, Providence College

Welcome New Members

ACUTA Online Press Room


Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian Apr 2005

Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian

Papers in Biotechnology

Zirconia particles modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTPA), further referred to as r_PEZ, were studied as a support material for use in chromatography. Our previous studies have demonstrated the utility of r_PEZ in the separation of immunoglobulins from biological fluids. In the present study we sought to understand the underlying factors and identify the rate-limiting mechanisms that govern the transport of biomolecules in r_PEZ. Pulse injection techniques were used to elucidate the individual mass transfer parameters. Elution profiles obtained under retained and unretained conditions were approximated by the Gaussian equation and the corresponding HETP contributions were estimated. The dependence of …


Development Of A Novel Microreactor For Improved Chemical Reaction Conversion, Yu Liang Apr 2005

Development Of A Novel Microreactor For Improved Chemical Reaction Conversion, Yu Liang

Doctoral Dissertations

Microreactors have been widely studied over the past two decades for different chemical reactions, to develop new analytical capabilities, and to obtain high mixing performance in the reactors. The main objectives of this work are to investigate the effect of different microchannel structures on the fluid properties and mixing behavior in microreactors, and to design, fabricate, and test a novel microreactor for higher conversion in a chemical reaction. The development of this novel microreactor is intended to provide a valuable guideline in achieving enhanced chemical mixing and to make available a solid research base for optimization of the yield of …


A Numerical Method For Obtaining An Optimal Temperature Distribution In A 3d Triple-Layered Cylindrical Skin Structure, Le Zhang Apr 2005

A Numerical Method For Obtaining An Optimal Temperature Distribution In A 3d Triple-Layered Cylindrical Skin Structure, Le Zhang

Doctoral Dissertations

In recent years, it has been interesting to research hyperthermia combined with radiation and cytotoxic drugs to enhance the killing of tumors. The crucial problem is that when heating the tumor tissues, one needs to keep the surrounding normal tissue below a temperature that will produce harm. Thus, it is important to obtain the temperature field of the entire treatment region. The objective of this dissertation is to develop a numerical model for obtaining an optimal temperature distribution in a 3D triple-layered cylindrical skin structure. To this end, we pre-specify the temperatures to be obtained at the center and perimeter …


Intelligent Control Of Nonlinear Systems With Actuator Saturation Using Neural Networks, Wenzhi Gao Apr 2005

Intelligent Control Of Nonlinear Systems With Actuator Saturation Using Neural Networks, Wenzhi Gao

Doctoral Dissertations

Common actuator nonlinearities such as saturation, deadzone, backlash, and hysteresis are unavoidable in practical industrial control systems, such as computer numerical control (CNC) machines, xy-positioning tables, robot manipulators, overhead crane mechanisms, and more. When the actuator nonlinearities exist in control systems, they may exhibit relatively large steady-state tracking error or even oscillations, cause the closed-loop system instability, and degrade the overall system performance. Proportional-derivative (PD) controller has observed limit cycles if the actuator nonlinearity is not compensated well. The problems are particularly exacerbated when the required accuracy is high, as in micropositioning devices. Due to the non-analytic nature of the …


Moveable Tobacco Curing Frames, George A. Duncan, Larry D. Swetnam, Linus R. Walton Apr 2005

Moveable Tobacco Curing Frames, George A. Duncan, Larry D. Swetnam, Linus R. Walton

Agricultural Engineering Extension Publications

Moveable (or portable) curing frames offer the tobacco grower another option for successfully reducing labor and costs for producing air-cured tobacco. Reducing labor and costs is essential to continuing profitable tobacco production.

Two designs that use the cantilever-beam concept for supporting two rails of stick tobacco on a central beam are shown and explained in this publication. Further details of construction and covering are shown in the following drawings.


User-Controlled, Multimedia-Enhanced Communication Using Prior Knowledge And Experience, S. R. Subramanya, Byung K. Yi Apr 2005

User-Controlled, Multimedia-Enhanced Communication Using Prior Knowledge And Experience, S. R. Subramanya, Byung K. Yi

Electrical and Computer Engineering Faculty Research & Creative Works

This article focuses on enriching the communication, experience between human beings interacting through different kind of devices, including mobile phones and PDAs. the key point is how to effectively exploit multimedia data to enhance the richness of communication without overloading the communication channel. to this end, the system tries to minimize the quantity of information transmitted over the networks and to maximize the usage of locally stored information. the proposed system sends several kinds of data, including continuous video, video clips, still images, and avatars, over the communication channel. the specific data that are sent are based on the parameters …


The Coupling Effect Of Interfacial Adhesion And Tensile Residual Stress On A Thin Membrane Adhered To A Flat Punch, Kai Tak Wan, Lior Kogut Apr 2005

The Coupling Effect Of Interfacial Adhesion And Tensile Residual Stress On A Thin Membrane Adhered To A Flat Punch, Kai Tak Wan, Lior Kogut

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Adhesion and residual stress play a critical role in the performance and reliability of microdevices, in particular, the cross bridge of RF microswitches. to investigate their combinatorial influences on thin films, an elastic model is constructed for a clamped circular membrane in contact with the planar surface of a rigid cylindrical punch. External force applied to the punch leads to thin film delamination and ultimately 'pull-off' at a critical non-zero contact radius. Characteristic trends of the mechanical responses were obtained for fixed load and fixed grips in terms of pull-off force, punch displacement and contact radius. It is shown that …


Examination Of Economical Methods For Repairing Highway Landslides, Liecheng Sun, Tommy C. Hopkins, Tony L. Beckham, Bixian Ni Apr 2005

Examination Of Economical Methods For Repairing Highway Landslides, Liecheng Sun, Tommy C. Hopkins, Tony L. Beckham, Bixian Ni

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet spends millions of dollars each year in the repairs of highway landslides. In previous research, an inventory of highway landslides showed that about 1440 landslides of various sizes exist on major roadways maintained by the Kentucky Transportation Cabinet. Moreover, emergency repairs can exceed one million dollars for large embankment failures. In many instances, drilled-in, or driven, railroad steel rails were frequently used as a stop-gap measure to halt landslide movements or those efforts were tried as a permanent solution. The use of rails to serve as a restraining structure was usually not successful when the height …


Programmable Process Flow Networks, Filip D. Cuckov Apr 2005

Programmable Process Flow Networks, Filip D. Cuckov

Electrical & Computer Engineering Theses & Dissertations

A model that introduces programmability to processes occurring in a cargo terminal simulation through the use of a process language is presented in this thesis. The model provides a means for a straight-forward definition, and redefinition of changing processes, their incorporation in the simulation architecture and efficient execution. The model was built to investigate a solution for transforming the cargo terminal simulation CPortS into a process-oriented simulation without hard-coded processes. The approach taken separates the system into an architecture and a set of processes which utilize and interact with the architecture's resources and infrastructure. The processes that take place within …


Creating Software [Sic] Environments On An M-Node Beowulf Cluster To Execute Discrete-Event Simulations, Jermaine Fitz-Gerald Headley Apr 2005

Creating Software [Sic] Environments On An M-Node Beowulf Cluster To Execute Discrete-Event Simulations, Jermaine Fitz-Gerald Headley

Electrical & Computer Engineering Theses & Dissertations

This thesis describes the development of a software tool that facilitates the creation of software environments that make a simulation tool execute k replications of an application program on several nodes of an M-node Beowulf cluster. It is assumed that each cluster-node consists of p processors. The p processors that are contained in the master cluster-node are termed master processors, and the p processors that are contained in a slave cluster-node are termed slave processors. The slave processors are used to execute the replications, while the master processors are dedicated to schedule the replications and process other housekeeping chores. For …


Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan Apr 2005

Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Reality (VR) applications is challenging where application developers are required to have expertise in the target VR technologies along with the problem domain expertise. New VR technologies impose a significant learning curve to even the most experienced VR developer. The proposed solution relies on synthesis to automate the migration of a VR application to a new unfamiliar VR platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) was developed, that serves as a superset/model representation of the target virtual world. Input modules were developed to populate the framework with the capabilities of the virtual world …


Generalization Issues In Pattern Classification Applied To Speaker Identification, Mame C. Sall Apr 2005

Generalization Issues In Pattern Classification Applied To Speaker Identification, Mame C. Sall

Electrical & Computer Engineering Theses & Dissertations

This thesis is an extension of previous work on speaker identification, but with a primary focus on the generalization performance of patterns classifiers for speaker identification. The goal for all pattern classifiers is to generalize to new data, not just perform well on the training data set. The error on the training data is typically a biased estimate of the generalization error. The training set error tends to be smaller than the generalization error if the model is selected such that it minimizes the training error. Therefore, the training error alone should not be used as a good predictor of …


Static And Modal Analysis Of The Magnetic Levitation Vehicle, Santosh Kumar Desetty Apr 2005

Static And Modal Analysis Of The Magnetic Levitation Vehicle, Santosh Kumar Desetty

Mechanical & Aerospace Engineering Theses & Dissertations

The magnetic levitation train project at Old Dominion University has been stalled due to many technical problems. The control system is the main component of the vehicle, which is supposed to maintain an intended gap of 1 cm between the vehicle and the track while traveling, hence providing a smooth ride. The goal of the project is to document the mathematics of the complete system so that the control algorithm can be implemented and modified with the expectation of obtaining an improved levitation and propulsion.

The complete system includes the vehicle, the track, and the concrete guide-way. The focus of …


An Application And Evaluation Of A Methodology For Testing Operational Level Training Simulations, Karl Dean Neal Apr 2005

An Application And Evaluation Of A Methodology For Testing Operational Level Training Simulations, Karl Dean Neal

Computational Modeling & Simulation Engineering Theses & Dissertations

The Virginia Modeling, Analysis and Simulation Center has developed a methodology for testing operational-level training simulation systems. The methodology is built on analyses of the military tasks that an operational-level simulation is intended to train. These tasks are derived from the U.S. Department of Defense Universal Joint Task List. The methodology analyzes the categories of capabilities the simulation should have to support those tasks based on operational-level-military entities and actions. Cross-referencing the tasks and capabilities leads to functionality items the simulation should have. The methodology focuses on training joint force command tasks and decision making at the operational level of …


Experimental Determination Of Convection Boiling Curves For Water And Ethylene Glycol In A Rectangular Channel With Localized Heating, Andrew T. O'Neill Apr 2005

Experimental Determination Of Convection Boiling Curves For Water And Ethylene Glycol In A Rectangular Channel With Localized Heating, Andrew T. O'Neill

Masters Theses

Convective boiling experiments were conducted to show the effects of velocity, pressure, and subcooling on both water and a water-ethylene glycol mixture. Boiling curves were obtained in a 30 mm wide by 20 mm high rectangular channel with an upward facing 20 mm wide by 30 mm long rectangular copper heater. The velocity ranged from 0.5 m/s to 4.0 m/s, the pressure ranged from 1.0 atm to 2.6 atm, and the subcooling ranged from 10°C to 50°C. The curves were generated with measured heat fluxes up to 100W/cm2 . The inlet conditions of temperature, velocity, and pressure were maintained …


Blood Flow Measurements With Magnetic Resonance Phase Velocity Mapping, George P. Chatzimavroudis Apr 2005

Blood Flow Measurements With Magnetic Resonance Phase Velocity Mapping, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic resonance (MR) phase velocity mapping (PVM) is a non-invasive technique that can measure the flow velocity in any spatial direction in an imaging slice. This technique has wide application in the clinical field in quantifying blood flow, as well as in non-biomedical areas. This review describes the value and/or potential of MR PVM as a diagnostic/monitoring technique in heart valve regurgitation and in the total cavo-pulmonary connection. A single slice placed in the aortic root can accurately quantify the aortic regurgitant volume. A multi-slice control volume method has high potential for the quantification of the mitral regurgitant volume. …


Segmentation Of Non-Viable Myocardium In Delayed Enhancement Magnetic Resonance Images, Arunark Kolipaka, George P. Chatzimavroudis, Richard D. White, Thomas P. O’Donnell, Randolph M. Setser Apr 2005

Segmentation Of Non-Viable Myocardium In Delayed Enhancement Magnetic Resonance Images, Arunark Kolipaka, George P. Chatzimavroudis, Richard D. White, Thomas P. O’Donnell, Randolph M. Setser

Chemical & Biomedical Engineering Faculty Publications

Purpose: To evaluate six algorithms for segmenting non-viable left ventricular (LV) myocardium in delayed enhancement (DE) magnetic resonance imaging (MRI). Methods: Twenty-three patients with known chronic ischemic heart disease underwent DE-MRI. DE images were first manually thresholded using an interactive region-filling tool to isolate non-viable myocardium. Then, six thresholding algorithms, based on the image intensity characteristics of either LV blood pool (BP), viable LV myocardium, or both, were applied to each image. For the Mean−2SDBP algorithm, thresholds were equal to the mean BP intensity minus twice its standard deviation. For the Mean+2SDSemi, Mean+3SDSemi, Mean+2SDAuto …


Reduction Of Stresses On Buried Rigid Highway Structures Using The Imperfect Ditch Method And Expanded Polystyrene (Geofoam), Liecheng Sun, Tommy C. Hopkins, Tony L. Beckham Apr 2005

Reduction Of Stresses On Buried Rigid Highway Structures Using The Imperfect Ditch Method And Expanded Polystyrene (Geofoam), Liecheng Sun, Tommy C. Hopkins, Tony L. Beckham

Kentucky Transportation Center Research Report

The study of earth pressure distribution on buried structures has a great practical importance in constructing highway embankments above pipes and culverts. Based on Spangler’s research, the supporting strength of a conduit depends primarily on three factors: 1. the inherent strength of the conduit; 2. the distribution of the vertical load and bottom reaction; and, 3. the magnitude and distribution of lateral earth pressures which act against the sides of the structure. Considering high fills above them and high earth pressures they may experience, rigid culverts are usually used underneath highway embankments. To reduce high vertical earth pressures acting on …


Safety And Capacity Evaluation For Interstates In Kentucky, Adam J. Kirk, Jerry G. Pigman, Kenneth R. Agent, Barry House Apr 2005

Safety And Capacity Evaluation For Interstates In Kentucky, Adam J. Kirk, Jerry G. Pigman, Kenneth R. Agent, Barry House

Kentucky Transportation Center Research Report

This analysis and evaluation was directed toward assessing safety and capacity issues on interstates in Kentucky and, particularly, the manner in which commercial vehicle traffic affects these issues. Analyses was undertaken to show past trends and project future traffic. Previous research was relied upon to show the level of safety on each of the interstates relative to statewide averages. Analyses were performed to evaluate the impact on safety when comparing segments by number of lanes available for through traffic (4, 6, and 8-lane highway sections). Delay on the interstates was calculated based on closure times due to crashes and estimates …


Nanomechanical Characterization Of Cavity Growth And Rupture In Hydrogen-Implanted Single-Crystal Batio3., Young-Bae Park, Patrick Nardi, Xiaodong Li, Harry A. Atwater Apr 2005

Nanomechanical Characterization Of Cavity Growth And Rupture In Hydrogen-Implanted Single-Crystal Batio3., Young-Bae Park, Patrick Nardi, Xiaodong Li, Harry A. Atwater

Faculty Publications

A thermodynamic model of cavitynucleation and growth in ion-implanted single-crystal BaTiO3 layer is proposed, and cavity formation is related to the measured mechanical properties to better understand hydrogen implantation-induced layer transfer processes for ferroelectric thin films. The critical radius for cavitynucleation was determined experimentally from blistering experiments performed under isochronal anneal conditions and was calculated using continuum mechanical models for deformation and fracture, together with thermodynamic models. Based on thermodynamic modeling, we suggest that cavitiesgrow toward the cracking criteria at a critical blister size whereupon gas is emitted from ruptured cavities. The main driving force for layer splitting is …


Ballistic Anisotropic Magnetoresistance, Julian P. Velev, Renat F. Sabirianov, Sitaram Jaswal, Evgeny Y. Tsymbal Apr 2005

Ballistic Anisotropic Magnetoresistance, Julian P. Velev, Renat F. Sabirianov, Sitaram Jaswal, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

Electronic transport in ferromagnetic ballistic conductors is predicted to exhibit ballistic anisotropic magnetoresistance—a change in the ballistic conductance with the direction of magnetization. This phenomenon originates from the effect of the spin-orbit interaction on the electronic band structure which leads to a change in the number of bands crossing the Fermi energy when the magnetization direction changes. We illustrate the significance of this phenomenon by performing ab initio calculations of the ballistic conductance in ferromagnetic Ni and Fe nanowires which display a sizable ballistic anisotropic magnetoresistance when magnetization changes direction from parallel to perpendicular to the wire axis.


Ceg 210-01: Pc Networking I, Karen Meyer Apr 2005

Ceg 210-01: Pc Networking I, Karen Meyer

Computer Science & Engineering Syllabi

Introduction to PC networking hardware, concepts, and technologies. Focus is on LAN Administration.


Ceg 260-01: Digital Computing Hardware/Switching Circuits, Eric Maston Apr 2005

Ceg 260-01: Digital Computing Hardware/Switching Circuits, Eric Maston

Computer Science & Engineering Syllabi

We will discuss and cover basic digital, combinational and sequential logic systems. Labs will be used to gain valuable practical experience in implementing elementary circuits and logic designs.


Ceg 210-01: Pc Networking I, Karen Meyer Apr 2005

Ceg 210-01: Pc Networking I, Karen Meyer

Computer Science & Engineering Syllabi

Introduction to PC networking hardware, concepts, and technologies. Focus is on LAN administration, and hardware and software configuration.