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Articles 173131 - 173160 of 198061

Full-Text Articles in Engineering

Vibration Control Of Robotic Modules Using Input Shaping Algorithm, Murat Eren Jan 1997

Vibration Control Of Robotic Modules Using Input Shaping Algorithm, Murat Eren

Theses

In this thesis, vibration control using input shaping algorithm is studied. Vibration Control of flexible structures is an important problem and has been an active research area. Different approaches have been developed for vibration control which can be divided roughly into feedback and feedforward methods. Feedback methods need measurements and on-line calculation of the controller outputs. Although feedback methods are generally more robust and have a number of well known performance advantages, proper use of feedforward control can also significantly improve the speed of response of the system.

Input shaping is one of these feedforward methods. It has been successfully …


Experimental Investigation Of Collisional Properties Of Spheres, Laurent Labous Jan 1997

Experimental Investigation Of Collisional Properties Of Spheres, Laurent Labous

Theses

We present experimental results on the collisional properties of spheres obtained through high-speed video analysis. An apparatus is built that produces collisions of spheres of various sizes with a wide range of impact, velocities and incidence angles.

Edge detection techniques are implemented to track the position of the spheres from frame to frame whereby the translational velocities may be computed. In order to determine the rotational velocities, small markers are imprinted on the surfaces of the spheres and also tracked and matched from one frame to the next.. From the pre and post collision kinematic data, three collisional properties are …


Three-Dimensional Stress Analysis Of The Femur With Prosthetic Hip Stem Utilizing Computed Tomography Scans Of The Femur For Geometry And Material Properties, Thomas J. Lavin Jan 1997

Three-Dimensional Stress Analysis Of The Femur With Prosthetic Hip Stem Utilizing Computed Tomography Scans Of The Femur For Geometry And Material Properties, Thomas J. Lavin

Theses

Three-dimensional finite element stress analyses of the femur with prosthesis hip stem were performed for two cases, one male and one female, using ideally bonded cemented titanium prostheses. Computed tomography data files were used to derive the three-dimensional femur geometry and material properties for each cortical bone element. The maximum shear stress (4.7 MPa) in the cement was greater then the maximum tensile stress and occurred at the cement-bone interface. The tensile stresses in the cement were less then the fatigue strength of the cement. The stress patterns were quite similar for the two cases.

A data analysis program was …


Optimization Of Ion-Exchange Chromotography With Multiple Gradient Inputs For Protein Separations, Tariq Mahmood Jan 1997

Optimization Of Ion-Exchange Chromotography With Multiple Gradient Inputs For Protein Separations, Tariq Mahmood

Theses

Gradient elution chromatography is an efficient technique for adjusting the retention of sample components during liquid chromatographic separations. However, the optimization of gradient elution is usually done by trial and error. Thus, for large scale processes this results in expensive and time consuming design and operations. Peak resolution that describes the degree of separation is a commonly used parameter for chromatographic processes. However, in processes where operating time and product dilution are of great importance, resolution alone is not adequate for describing the separation efficiency.

A new parameter "resolution optimization factor" is used for the optimization of gradient elution processes. …


A Methodology For The Design Of An Integrated Air Stripping/Biofiltration Process To Clean Contaminated Aquifers, Pothitos Ioannis Stamatiadis Jan 1997

A Methodology For The Design Of An Integrated Air Stripping/Biofiltration Process To Clean Contaminated Aquifers, Pothitos Ioannis Stamatiadis

Theses

This thesis deals with the conceptual design of an integrated air stripping/biofiltration process for cleaning aquifers contaminated with volatile organic pollutants. In this technology, the pollutant is transferred from the aquifer to an air stream which is subsequently treated in a biofilter. The work presented here is an effort to develop a design methodology for the integrated process and suggests a general, quantitative approach which can be used in preliminary technology evaluation. This methodology involves relatively simple equations for the stripping process and detailed (oftentimes complex) models for biofiltration under conditions of continuous variation of the properties of the polluted …


Experimental Study Of The Rise Of A Large Sphere In A Vibrated Bed Of Monodisperse Spheres, Loic Vanel Jan 1997

Experimental Study Of The Rise Of A Large Sphere In A Vibrated Bed Of Monodisperse Spheres, Loic Vanel

Theses

As a simplified way to study size segregation mechanisms, the rise of a single large sphere in a vibrated bed of smaller monodisperse spheres is investigated. The time it takes for the ball to rise from the bottom of the bed to the surface is measured in a very wide range of vibration amplitude, frequency and acceleration. Rise regimes are identified and are classified according to the macroscopic behaviors displayed by the granular bed: heaping, convection without heaping and crystallization. The influence of the large sphere's size on the rise velocity is described. The scaling features of the vibration amplitude …


A Student Training Manual For Running The Hysim Computer Simulation Program, Roberta Rosty Jan 1997

A Student Training Manual For Running The Hysim Computer Simulation Program, Roberta Rosty

Theses

Hyprotech's HYSIM computer simulation program is used in the chemical processing industry (CPI) to simulate unit operations, which aid in the design of various different kinds of processing plants. It is important then that chemical engineering students should gain early exposure to a simulation program such as HYSIM, in order to facilitate their comprehension of process engineering design work using this type of program, and to bridge the gap between the textbook knowledge they gain of unit operations in the classroom with some of the actual process engineering work-a-day methods available for solving problems.

The objective of this work was …


Tcp/Ip Traffic Over Atm Network With Abr Flow And Congestion Control, Liping An Jan 1997

Tcp/Ip Traffic Over Atm Network With Abr Flow And Congestion Control, Liping An

Theses

Most traffics over the existing ATM network are generated by applications running over TCP/IP protocol stack. In the near future, the success of ATM technology will depend largely on how well it supports the huge legacy of existing TCP/IP applications.

In this thesis, we study and compare the performance of TCP/IP traffic running on different rate based ABR flow control algorithms such as EFCI, ERICA and FMMRA by extensive simulations. Infinite source-end traffic behavior is chosen to represent, FTP application running on TCP/IP. Background VBR traffic with different ON-OFF frequency is introduced to produce transient network states as well as …


Synthesis And Characterization Of Silicon Dioxide Thin Films By Low Pressure Chemical Vapor Deposition, Sutham Niyomwas Jan 1997

Synthesis And Characterization Of Silicon Dioxide Thin Films By Low Pressure Chemical Vapor Deposition, Sutham Niyomwas

Theses

Ditertiarybutylsilane ( DTBS ) and oxygen have been used as precursors to produce silicon dioxide films by low pressure chemical vapor deposition. These films were synthesized in the temperature range of 600°C to 800°C at constant pressure, and at different gas flow composition. The films were found to be uniform with a composition that varied with deposition temperature and gas flow ratio. The growth rate was found to follow an Arrhenius behavior with an apparent activation energy of 2.62 kcal/mol. The growth rate was seen to increase with higher distance between wafers and to vary as a function of square …


Tractor Test Museum Committee Minutes Jan 28, 1997, Tractor Museum Jan 1997

Tractor Test Museum Committee Minutes Jan 28, 1997, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Foundation Budget Recognition Certificates By-law changes


Evaluation Of Resources And Energy Systems At Fort Jefferson Garden Key, Dry Tortugas National Park, Florida Solar Energy Center, James Dunlop Jan 1997

Evaluation Of Resources And Energy Systems At Fort Jefferson Garden Key, Dry Tortugas National Park, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report presents an evaluation of the resources and energy systems at Fort Jefferson, located on Garden Key in Dry Tortugas National Park, Florida. Conducted by Florida Solar Energy Center staff on June 11-12, 1997, this evaluation builds on a prior evaluation conducted in May 1989. The purpose of this evaluation was to document the energy and resource needs at the site, and to identify possibilities for reduced costs through conservation measures and renewable energy options.

Approximately 700 kWh of electrical energy is used at Fort Jefferson on a daily average, supplied exclusively by diesel-fueled generators. Average diesel fuel consumption …


The Influence Of The Wastewater Drainage From The Las Vegas Valley On The Limnology Of Boulder Basin, Lake Mead, Nevada-Arizona, James F. Labounty, Michael J. Horn, Bureau Of Reclamation Jan 1997

The Influence Of The Wastewater Drainage From The Las Vegas Valley On The Limnology Of Boulder Basin, Lake Mead, Nevada-Arizona, James F. Labounty, Michael J. Horn, Bureau Of Reclamation

Publications (WR)

Lake Mead, Colorado River, Arizona-Nevada, is one of the most heavily used reservoirs in the western United States, providing abundant recreational opportunities as well as downstream domestic and agricultural water for over 22 million users. Based on average nutrient levels and productivity, Lake Mead is classified as mildly mesotrophic. The interflow of the Colorado River dominates the limnology of much of the 106 km-long reservoir, and may still be identified at Hoover Dam under certain conditions. The lower basin of Lake Mead ending at Hoover Dam is known as Boulder Basin and is near the Las Vegas metropolitan area. Las …


Affinity Adsorption Of Adsorbates Into Spherical Monodisperse And Bidisperse Porous Perfusive And Purely Diffusive Adsorbent Particles Packed In A Column. Parameter Estimation In The Laplace Transform Domain, G. A. Heeter, Athanasios I. Liapis Jan 1997

Affinity Adsorption Of Adsorbates Into Spherical Monodisperse And Bidisperse Porous Perfusive And Purely Diffusive Adsorbent Particles Packed In A Column. Parameter Estimation In The Laplace Transform Domain, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A novel mathematical method for parameter estimation is proposed and used to estimate in the Laplace transform domain the values of the parameters that characterize the mechanisms of intraparticle diffusion and convection in spherical perfusive or purely diffusive adsorbent particles with a monodisperse or with a bidisperse porous structure when the adsorbent particles are packed in a column. The parameter estimation method in the Laplace transform domain presented in this work is significantly simpler, easier to use and dramatically faster than the conventional parameter estimation procedure in the time domain, which requires the repeated numerical solution of the partial differential …


The Role Of Computer Simulation In The Context Of Zero-Emission Power Plants, Jim Mcgovern Jan 1997

The Role Of Computer Simulation In The Context Of Zero-Emission Power Plants, Jim Mcgovern

Other resources

The role of computer simulation in the context of zero-emission power plants is outlined. The use of computer simulation models to simulate zero-emission power plants in fine detail is strongly recommended.


Batteries And Charge Control In Stand-Alone Photovoltaic Systems: Fundamentals And Application, Florida Solar Energy Center, James Dunlop Jan 1997

Batteries And Charge Control In Stand-Alone Photovoltaic Systems: Fundamentals And Application, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report presents an overview of battery technology and charge control strategies commonly used in stand-alone photovoltaic (PV) systems. This work is a compilation of information from several sources, including PV system design manuals, research reports, data from component manufacturers, and lessons learned from hardware evaluations.


Complexity Theory And Systems Theory, Martin Zwick Jan 1997

Complexity Theory And Systems Theory, Martin Zwick

Complex Systems Faculty Publications and Presentations

I use the label, “complexity theory,” for the research program which studies nonlinear dynamics, “complexity,” “complex adaptive systems,” “artificial life,” etc., and whose intellectual Mecca in the United States is the Santa Fe Institute. I use the label, “systems theory,” for the research program which crystallized after World War II under the names of “general systems theory” and “cybernetics,” and which subsumed such postwar scientific developments as information theory, game theory, feedback control theory, and the beginnings of computer science and artificial intelligence. The central thesis of this paper is that complexity theory is a continuation and revitalization of systems …


Effects Of Monomer Structure Ontheir Organization And Polymerizationin A Smectic Liquid Crystal, C. Allan Guymon, Erik N. Hoggan, Noal A. Clark, Thomas P. Rieker, David M. Walba, Christopher N. Bowman Jan 1997

Effects Of Monomer Structure Ontheir Organization And Polymerizationin A Smectic Liquid Crystal, C. Allan Guymon, Erik N. Hoggan, Noal A. Clark, Thomas P. Rieker, David M. Walba, Christopher N. Bowman

Faculty Publications

Photopolymerizable diacrylate monomers dissolved in fluid-layer smectic A and smectic C liquid crystal (LC) hosts exhibited significant spatial segregation and orientation that depend strongly on monomer structure. Small, flexible monomers such as 1,6-hexanediol diacrylate (HDDA) oriented parallel to the smectic layers and intercalated, whereas rod-shaped mesogen-like monomers such as 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) oriented normal to the smectic layers and collected within them. Such spatial segregation caused by the smectic layering dramatically enhanced photopolymerization rates; for HDDA, termination rates were reduced, whereas for C6M, both the termination and propagation rates were increased. These polymerization precursor structures suggest novel materials-design paradigms for gel …


The Decision To Reactivate A First-Generation Soviet Nuclear Power Plant: Conceptual And Decision-Analytic Frameworks, John M. Gleason Jan 1997

The Decision To Reactivate A First-Generation Soviet Nuclear Power Plant: Conceptual And Decision-Analytic Frameworks, John M. Gleason

RISK: Health, Safety & Environment (1990-2002)

Explores a variety of factors that led to reopening the Armenian Metsamor facility notwithstanding general agreement that this is unwarranted technologically.


Acuta Enews January 1997, Vol.26, No. 1 Jan 1997

Acuta Enews January 1997, Vol.26, No. 1

ACUTA Newsletters

In This Issue

Do You Have a Voice Mail Handbook?

A Few Words of Advice

Board Report

ACUTA Journal: Second Issue Topics

Membership Committee

Reimbursing Personal Calls

Editorial Board Named

DC at a Glance

WCU on the Cutting Edge

Interstate Long Distance Tariffs Eliminated

Block it, again

Welcome New Members


Public Perceptions Of The Midwest’S Pavements - Minnesota - Phase I (Winter Ride), University Of Wisconsin - Extension, Wisconsin Survey Research Laboratory, Marquette University, Department Of Civil, Construction, And Environmental Engineering Jan 1997

Public Perceptions Of The Midwest’S Pavements - Minnesota - Phase I (Winter Ride), University Of Wisconsin - Extension, Wisconsin Survey Research Laboratory, Marquette University, Department Of Civil, Construction, And Environmental Engineering

Transportation Research Center: Public Perception of Midwest Pavements

The Minnesota Winter Ride Survey was designed to gauge the extent to which motorists were tolerant of the rougher ride of pavements on rural two-lane highways in the winter. Survey objectives, therefore, were centered around this focal question of winter ride tolerance. A telephone survey was conducted during the first quarter of the year (January 15 to March 15, 1997) by the Wisconsin Survey Research Laboratory (WSRL), which simultaneously conducted a similar survey in Wisconsin. Random digit dial samples were drawn for both states according to accepted sampling procedure. The survey data set provided by WSRL included 417 respondents.

Analysis …


Analytical Models For Vehicle/Gap Distribution On Automated Highway Systems, Jacob Tsao, Randolph W. Hall, Indrajit Chatterjee Jan 1997

Analytical Models For Vehicle/Gap Distribution On Automated Highway Systems, Jacob Tsao, Randolph W. Hall, Indrajit Chatterjee

Faculty Publications

Highway congestion has in recent years become a pervasive problem for urban and suburban areas alike. The concept of Automated Highway Systems is based on the belief that integration of sensing, communication, and control technologies into vehicles and highways can lead to a large improvement in capacity and safety without requiring a significant amount of additional highway right-of-way. A fundamental determinant of Automated Highway Systems capacity is the vehicle-following rule, the rule that governs the behavior of vehicles traveling along a common lane (e.g., the spacing between any two longitudinally adjacent vehicles). Vehicle following affects the longitudinal capacity (achievable flow …


Laser Profilometry Of Polymeric Materials, Eduard A. Kulik, Patrick Calahan Jan 1997

Laser Profilometry Of Polymeric Materials, Eduard A. Kulik, Patrick Calahan

Cells and Materials

Unlike the mechanical stylus profilometer, the laser profilometer does not damage the surface of soft materials. However, the accuracy of autofocusing of the laser profilometer is not always sensitive enough to discriminate the material/air interface from subsurface structures of semitransparent polymers. In the present study over ten polymeric surfaces were gold coated in order to investigate the effect of gold coating on the readings of a laser profilometer. Surface profiles of some polymeric materials became much smoother even if a very thing gold coating was applied to increase the reflection from the surface. It was concluded that a thin gold …


Image Analysis Of Primary Bone-Derived Cells On Different Polystyrene Surfaces, R. M. Shelton, G. Landini Jan 1997

Image Analysis Of Primary Bone-Derived Cells On Different Polystyrene Surfaces, R. M. Shelton, G. Landini

Cells and Materials

The aim of the present study was to examine whether two different cell populations could be discerned using image analysis of a variety of morphological parameters on bacteriological and tissue culture polystyrene surfaces. Rat periosteal and osteoblast cultures were established on both polystyrene petri dishes and examined using phase contrast microscopy after one and two weeks before capturing digital images which were stored on a personal computer. The digital images were processed to identify the cell margins or perimeter, from which seven different morphological parameters were calculated using a program developed (by GL) for both the cell populations on the …


Corrosion Of Metal Hip Arthroplasties And Its Possible Role In Loosening, H. K. Koerten, J. J. A. M. Van Raay, J. J. M. Onderwater, F. P. Bernoski, P. M. Rozing Jan 1997

Corrosion Of Metal Hip Arthroplasties And Its Possible Role In Loosening, H. K. Koerten, J. J. A. M. Van Raay, J. J. M. Onderwater, F. P. Bernoski, P. M. Rozing

Cells and Materials

Tissue removed with human hip arthroplasties during revision surgery of 45 patients was evaluated by transmission electron microscopy and X -ray microanalysis (XRMA). The results show that microscopic and submicroscopic particles are abundantly present in the tissue at the tissue/implant interface. XRMA of individual particles shows that the chemical composition of a portion of the particles was in agreement with that of the retrieved implants. Regularly, particulates with a dissimilar chemical composition were found. Sometimes, these particles could be recognized as filler particles of the cements used. Other particles could partly or completely be composed of the chemical elements that …


Macrophage Response To Polymethylmethacrylate Particles, Stephen M. Horowtiz Jan 1997

Macrophage Response To Polymethylmethacrylate Particles, Stephen M. Horowtiz

Cells and Materials

This paper reviews studies performed by this laboratory involving the macrophage response to implant particles. Through the development of a tissue culture model, we have studied the events which occur following macrophage phagocytosis of bone cement particles, the released mediators and cell interactions which may ultimately lead to bone resorption, and the inhibition of this process with the use of pharmaceutical agents. This is divided into the following sections: Histologic response of macrophages to cement particles I toxicity I and mediator release, the effects of particle size and composition on mediator release by macrophages, macrophage I osteoblast interactions, macrophage I …


Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert Jan 1997

Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.


Rheology Of Dense Bubble Suspensions, Ashok S. Sangani, Sang-Yoon Kang, Heng-Kwong Tsao, Donald L. Koch Jan 1997

Rheology Of Dense Bubble Suspensions, Ashok S. Sangani, Sang-Yoon Kang, Heng-Kwong Tsao, Donald L. Koch

Biomedical and Chemical Engineering - All Scholarship

The rheological behavior of rapidly sheared bubble suspensions is examined through numerical simulations and kinetic theory. The limiting case of spherical bubbles at large Reynolds number Re and small Weber number We is examined in detail. Here, Re = p y a^2 / u and We = p y^2 a^3 / s, a being the bubble radius, g the imposed shear, s the interfacial tension, and m and r , respectively, the viscosity and density of the liquid. The bubbles are assumed to undergo elastic bounces when they come into contact; coalescence can be prevented in practice by addition of …


Nusselt Number For Flow Perpendicular To Arrays Of Cylinders In The Limit Of Small Reynolds And Large Peclet Numbers, Ashok S. Sangani, Wei Wang Jan 1997

Nusselt Number For Flow Perpendicular To Arrays Of Cylinders In The Limit Of Small Reynolds And Large Peclet Numbers, Ashok S. Sangani, Wei Wang

Biomedical and Chemical Engineering - All Scholarship

The problem of determining the Nusselt number N, the nondimensional rate of heat or mass transfer, from an array of cylindrical particles to the surrounding fluid is examined in the limit of small Reynolds number Re and large Peclet number Pe. N in this limit can be determined from the details of flow in the immediate vicinity of the particles. These are determined accurately using a method of multipole expansions for both ordered and random arrays of cylinders. The results for N/Pe^1/3 are presented for the complete range of the area fraction of cylinders. The results of numerical simulations for …


A Global Computing Environment For Networked Resources, Haluk Topcuoglu, Salim Hariri Jan 1997

A Global Computing Environment For Networked Resources, Haluk Topcuoglu, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

Current advances in high-speed networks and WWW technologies have made network computing a cost-effective, high-performance computing alternative. New software tools are being developed to utilize efficiently the network computing environment. Our project, called Virtual Distributed Computing Environment (VDCE), is a high-performance computing environment that allows users to write and evaluate networked applications for different hardware and software configurations using a web interface. In this paper we present the software architecture of VDCE by emphasizing application development and specification, scheduling, and execution/runtime aspects.


An Information Security Education Initiative For Engineering And Computer Science, Shiu-Kai Chin, Cynthia E. Irvine, Deborah Frincke Jan 1997

An Information Security Education Initiative For Engineering And Computer Science, Shiu-Kai Chin, Cynthia E. Irvine, Deborah Frincke

Electrical Engineering and Computer Science - All Scholarship

This paper puts forward a case for an educational initiative in information security at both the undergraduate and graduate levels. Its focus is on the need for such education, the desired educational outcomes, and how the outcomes may be assessed. A basic thesis of this paper is that the goals, methods, and evaluation techniques of information and computer security are consistent with and supportive of the stated goals of engineering education and the growing movement for outcomes-based assessment in higher education.