Engineering Commons^™

Comparison Of Crude Oil Fouling Using Two Different Probes, A. P. Watkinson

Heat Exchanger Fouling and Cleaning: Fundamentals and Applications

A variety of different fouling rigs, each with its own advantages and disadvantages is available to assess crude oil fouling. In this research, fouling of three crude oils are compared, using two electrically heated annular probes with strikingly different modes of operation. The Hot Liquid Process Simulator (HLPS) was operated in single-pass mode, under creeping flow conditions for time durations of a few hours at constant surface temperature. The Portable Fouling Research Unit (PFRU) was operated at velocities a factor of 250 higher, and followed the fouling process over two or more days at constant heat flux, using re-circulation of …

Improvements And New Developments In Self-Cleaning Heat Transfer Leading To New Applications , Dick G. Klaren

Heat Exchanger Fouling and Cleaning: Fundamentals and Applications

Improvements in the design have made the fluidized bed heat exchanger better suitable for the revamp of existing vertical severely fouling heat exchangers in evaporators, crystallizers and reboilers into a self-cleaning configuration. Highly viscous non-Newtonian slurries used in mineral processing can benefit from the fluidized bed heat exchanger not only due to its self-cleaning performance, but also as a result of the shear-thinning action of the fluidized particles which dramatically lowers the viscosity of the slurry. New developments have created the possibility to design compact self-cleaning fluidized bed heat exchangers which can compete with plate and frame exchangers.

An Effective Cip Procedure For Removing Dairy Protein Based Deposit – A Laboratory Investigation, Xiao Dong Chen, Necati Özkan, Frank Qin, Hong Xin, Lin Lin

Heat Exchanger Fouling and Cleaning: Fundamentals and Applications

In this paper, examples of using an in-situ electrochemical cleaning technique are illustrated. It can be shown that while using the standard chemical for cleaning in the dairy industry, the application of the in-situ electrochemical method is very effective in removing the dairy protein based fouling deposits. Both the gel protocol developed earlier and the real fouling procedure have been used to evaluate the effectiveness of the new method.

Compressed Data Structures For Recursive Flow Classification, Edward W. Spitznagel

All Computer Science and Engineering Research

High-speed packet classification is crucial to the implementation of several advanced network services and protocols; many QoS implementations, active networking platforms, and security devices (such as firewalls and intrusion-detection systems) require it. But performing classification on multiple fields, at the speed of modern networks, is known to be a difficult problem. The Recursive Flow Classification (RFC) algorithm described by Gupta and McKeown performs classification very quickly, but can require excessive storage when using thousands of rules. This paper studies a compressed representation for the tables used in RFC, trading some memory accesses for space. The compression’s efficiency can be improved …

2003 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823 For Transmutation Applications, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the elevated temperature tensile properties of Alloy EP-823, a leading target material for accelerator-driven waste transmutation applications. This alloy has been proven to be an excellent structural material to contain the lead-bismuth-eutectic (LBE) nuclear coolant needed for fast spectrum operations. However, very little data exist in the open literature on the tensile properties of this alloy. The selection of Alloy EP-823 as the test material in the proposed task is based on the recommendation of our collaborator at the Los Alamos National Laboratory (LANL). The test material will be thermally treated prior …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean

Separations Campaign (TRP)

Two activities are proposed: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model will be continuously focusing on the integrated approach to the analysis of the materials separations associated with the TRP Program. A second portion of the project will streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to the systems engineering model. …

Multiscale Modeling Of Hysteretic Phenomena In Magnets „(Invited), Vladimir P. Antropov, Kirill D. Belashchenko

Nebraska Center for Materials and Nanoscience: Faculty Publications

Methodology of multiscale modeling of hysteretic phenomena in magnets is discussed. A practical combination of first-principles, micromagnetic, and microstructural calculations is constructed which allows one to study the hysteretic phenomena in hard magnets. Advantages and shortcomings of this approach are discussed. Multiscale nature of coercivity in CoPt type magnets is elucidated. Two sources of coercivity in polytwinned CoPt type magnets developing at different length scales, domain wall pinning at antiphase boundaries and splitting at twin boundaries, are illustrated for a realistic microstructure

Atomic, Electronic, And Magnetic Properties Of Magnetic Tunnel Junctions, I.I. Oleynik, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

We report results of first-principles density-functional studies of the atomic and electronic structure of Co/Al₂O₃/Co and Co/SrTiO₃/Co magnetic tunnel junctions (MTJs). The atomic structure has been studied for different interface terminations and the interfacial energetics was quantified based on the work of separation. Based on energetics of cohesion, the O-terminated and TiO₂-terminated interfaces were identified as the most stable structures for Co/Al₂O₃/Co and Co/SrTiO₃/Co MTJs, respectively. The electronic structure was analyzed using local densities of states. We found that the electronic structure of the O-terminated Co/Al …

Optical And Electrical Properties Of Pr0.8sr0.2mno3 Thin Films, Toshio Suzuki, Piotr Z. Jasinski, Vladimir Petrovsky, Xiao Dong Zhou, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The optical and electrical properties of Pr_0.8Sr_0.2MnO₃ thin films were discussed. It was found that the results of optical measurements were correlated with the annealing temperatures of the films and the shape of the optical spectra was found to change as the structure changed from an amorphous to crystalline structure. the electrical conductivity was found to be observed to be about three orders of magnitude higher for specimens which were crystalline as compared to amorphous.

Mechanisms Of Photoluminescence From Silicon Nanocrystals Formed By Pulsed-Laser Deposition In Argon And Oxygen Ambient, X. Y. Chen, Yongfeng Lu, Y. H. Wu, B. J. Cho, M. H. Liu, D. Y. Dai, W. D. Song

Department of Electrical and Computer Engineering: Faculty Publications

We have investigated the different mechanisms of photoluminescence (PL) of silicon nanocrystals due to the quantum confinement effect (QCE) and interface states. Si nanocrystals were formed by pulsed-laser deposition in inert argon and reactive oxygen gas. The collisions between the ejected species greatly influence the morphology of the Si nanocrystals and cause a transition from a film structure to a porous cauliflower-like structure, as the ambient gas pressure increases from 1 mTorr to 1 Torr. The oxygen content of the Si nanocrystals increases with increasing O₂ ambient pressure, and nearly SiO₂ stoichiometry is obtained when the O_{2 …}

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 2/16/03- 5/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

Progress continues on the analysis of casting and solidification of the melt into molds. Modeling results for constant pressure casting, which is more realistic, have been obtained and produce physically realistic results for flow that starts, flows, and then eventually stops as it enters the mold. Potential mass transfer modeling features (Lammuir’s law for example) are being studied to enhance the capabilities of a mass transfer in a detailed system model. Different parameters are being varied as part of a parametric study to evaluate factors that impact the flow of the melt into the molds. The ability to include the …

Yscat Backscatter Distributions, Benjamin E. Barrowes

Theses and Dissertations

YSCAT is a unique ultrawideband microwave scatterometer developed to investigate the sea surface under a variety of environmental and radar parameters. The YSCAT94 experiment consisted of a six month deployment on the WAVES research tower operated by the Canada Center for inland Waters (CCIW). Over 3500 hours of data were collected at 2Γ 3.05Γ 5.3Γ 10.02Γ and 14 GHz and at a variety of wind speeds, relative azimuth angles, and incidence angle.

A low wind speed "rolloff" of the normalized radar cross section (σ°) in YSCAT94 data is found and quantified. The rolloff wind speedΓ γΓ is estimated through regression …

An Implementation Of Field-Wise Wind Retrieval For Seawinds On Quikscat, Andrew S. Fletcher

Theses and Dissertations

Field-wise wind estimation (also known as model-based wind estimation) is a sophisticated technique to derive wind estimates from radar backscatter measurements. In contrast to the more traditional method known as point-wise wind retrieval, field-wise techniques estimate wind field model parameters. In this way, neighboring wind vectors are jointly estimated, ensuring consistency. This work presents and implementation for field-wise wind retrieval for the SeaWinds scatterometer on the QuikSCAT satellite.

Due to its sophistication, field-wise wind retrieval adds computational complexity and intensity. The tradeoffs necessary for practical implementations are examined and quantified. The Levenberg-Marquardt algorithm for minimizing the field-wise objective function is …

Multisensor Microwave Remote Sensing In The Cryosphere, Quinn P. Remund

Theses and Dissertations

Because the earth's cryosphere influences global weather patterns and climate, the scientific community has had great interest in monitoring this important region. Microwave remote sensing has proven to be a useful tool in estimating sea and glacial ice surface characteristics with both scatterometers and radiometers exhibiting high sensitivity to important ice properties. This dissertation presents an array of studies focused on extracting key surface features from multisensor microwave data sets. First, several enhanced resolution image reconstruction issues are addressed. Among these are the optimization of the scatterometer image reconstruction (SIR) algorithm for NASA scatterometer (NSCAT) data, an analysis of Ku-band …

A Field-Wise Retrieval Algorithm For Seawinds, Stephen L. Richards

Theses and Dissertations

In the spring of 1999 NASA will launch the scatterometer SeaWinds, beginning a 3 year mission to measure the ocean winds. SeaWinds is different from previous spaceborne scatterometers in that it employs a rotating pencil-beam antenna as opposed to fixed fan-beam antennas. The scanning beam provides greater coverage but causes the wind retrieval accuracy to vary across the swath. This thesis develops a filed-wise wind retrieval algorithm to improve the overall wind retrieval accuracy for use with SeaWinds data.

In order to test the field-wise wind retrieval algorithm, methods for simulating wind fields are developed. A realistic approach interpolates the …

Calibration Of And Attitude Error Estimation For A Spaceborne Scatterometer Using Measurements Over Land, Clarence J. Wilson Iii

Theses and Dissertations

The NASA Scatterometer (NSCAT) was launched August 20, 1996 aboard the National Space Development Agency of Japan's Advanced Earth Observing Spacecraft (ADEOS). NSCAT's primary mission was to measure radar backscatter over the world's oceans. These measurements are used to generate estimates of ocean wind speed and direction. Scatterometers must be calibrated before their measurements are scientifically useful. However, the calibration of NSCAT must be done in orbit. A new methodology for selecting land regions for use in extended target spaceborne scatterometer calibration is first developed. Next, a summary of the calibration technique used in this thesis is presented. While the …

Azimuth Modulation Of The Radar Backscatter At Near-Normal Incidence, Andrew D. Greenwood

Theses and Dissertations

Radar observations of the ocean surface are becoming increasingly important. Common applications are wind retrieval and global weather forecasting and characterization. Because of the common use of ocean radar measurements, it is important to understand the sensitivity of the backscatter to both radar parameters and surface parameters.

At near-normal incidence angles, it has been assumed that the radar backscatter exhibits little or no azimuth dependence (Colton, 1989). However, recent data taken by the BYU YSCAT radar system suggests that this is not the case. At an incidence angle of 10°, the YSCAT radar data shows from a fraction of a …

The Phase Gradient Autofocus Algorithm With Range Dependent Stripmap Sar, James S. Bates

Theses and Dissertations

The Phase Gradient Autofocus (PGA) algorithm is widely used in spotlight mode SAR for motion compensation. The Maximum Likelihood PGA (ML PGA) algorithm has been shown to be a superior autofocus method. The PGA is restricted to high altitude aircraft. Since lower altitude SARs have significant range dependencies that cannot be ignored, the PGA could not be used. This thesis eliminates the high altitude restriction and extends the PGA for use with all spotlight SARs. The new algorithm is tested with three images. Each image has a unique quality. A desert image provides a low signal to clutter ratio with …

Studies To Improve Estimation Of The Electromagnetic Bias In Radar Altimetry, Justin Dewitt Smith

Theses and Dissertations

In May of 2000 Jason-1, a joint project between NASA and the French space agency CNES, will be launched. Its mission is to continue the highly successful gathering of data which TOPEX/Poseidon has collected since August of 1992. The main goal of Jason-1 is to achieve higher accuracy in measuring the mean sea level (MSL). In order to do so, the electromagnetic (EM) bias must be estimated more accurately because it is the largest contributing error. This thesis presents two different studies which add to the knowledge and improve estimation of the EM bias, and thus assists Jason-1 in achieving …

Uncertainties In Oceanic Microwave Remote Sensing: The Radar Footprint, The Wind-Backscatter Relationship, And The Measurement Probability Density Function, Paul E. Johnson

Theses and Dissertations

Oceanic microwave remote sensing provides the data necessary for the estimation of significant geophysical parameters such as the near-surface vector wind. To obtain accurate estimates, a precise understanding of the measurements is critical. This work clarifies and quantifies specific uncertainties in the scattered power measured by an active radar instrument.

While there are many sources of uncertainty in remote sensing measurements, this work concentrates on three significant, yet largely unstudied effects. With a theoretical derivation of the backscatter from an ocean-like surface, results from this dissertation demonstrate that the backscatter decays with surface roughness with two distinct modes of behavior, …

A Methodology For The Design Of Spaceborne Pencil-Beam Scatterometer Systems, Michael W. Spencer

Theses and Dissertations

Spaceborne scatterometer instruments are important tools for the remote sensing of the Earth's environment. In addition to the primary goal of measuring ocean winds, data from scatterometers have proven useful in the study of a variety of land and cryopshere processes as well. Several satellites carrying scatterometers have flown in the last two decades. These previous systems have been "fan-beam" scatterometers, where multiple antennas placed in fixed positions are used. The fan-beam scatterometer approach, however, has disadvantages which limit its utility for future missions. An alternate approach, the conically-scanning "pencil-beam" scatterometer technique, alleviates many of the problems encountered with earlier …

Using Space Borne Microwave Sensors To Track Large Antarctic Icebergs, Jarom James Ballantyne

Theses and Dissertations

Studying Antarctic icebergs can provide insight into climatic changes of the Earth's frozen continent. Antarctic icebergs are regularly formed by the separations of massive sections of ice from ice shelves and glaciers.

The National Ice Center (NIC) is playing a major role in sea ice analysis and forecasts. As a part of its mission the NIC is using a variety of satellite sensors to track many large Antarctic icebergs. The NIC reports iceberg positions every 15-20 days. However, there are limitations in the NIC's iceberg tracking techniques. The areas covered by the images used by the NIC are limited to …

Apparatus And Method For Measurement Of Fluid Viscosity, Feredoon Behroozi

Patents (University of Northern Iowa)

A non-contact apparatus and method for mapping the wave profile of capillary waves on a fluid surface to determine viscosity of the fluid. Two conducting blades coupled to a sine wave generator are positioned spaced laterally above and near the surface of the fluid to generate a standing capillary wave on the fluid surface between the blades. A laterally moveable fiber optic probe is coupled to a laser to transmit laser light toward the fluid surface and to receive reflected light from the fluid surface. Part of the laser light reflects from the end of the probe and creates an …

Evolutionary Algorithms For Beginners, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This presentation offers a detailed introduction into the concepts and applications of evolutionary ideas in computing, adapted from genetics and evolution.

Ultrasonic Flowmeters In Determination Of Correlation Functions Of Velocity And Ultrasound Wave Fluctuations In Grid-Generated Turbulence, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

The paper is devoted to the experimental investigation of the statistical characteristics of the grid-generated turbulence produced in a wind tunnel. Ultrasonic time-of-flight method using dual transducers is utilized to develop a methodology for determination of the correlation functions of turbulent velocity and sound speed fluctuations. The ultrasonic flowmeter equation is considered in the form that includes effects of turbulent velocity and sound speed fluctuations. The influence of temperature inhomogeneities on ultrasonic wave propagation is investigated using a set of experiments with a heated grid. Utilization of high-speed digital data acquisition cards and LabView software for the experiments allows collecting …

Cpt-Based Probabilistic Assessment Of Seismic Soil Liquefaction Initiation., Robb E.S. Moss

Civil and Environmental Engineering

The correlation of seismic field performance with in situ index test results has been proven to be a reliable method for defining the threshold between liquefaction and non-liquefaction. The objective of this research was to define in the most accurate and unbiased manner possible the initiation of seismic soil liquefaction using the Cone Penetration Test (CPT). Case histories of occurrence and non-occurrence of soil liquefaction were collected from seismic events over the past three decades. These were processed to develop improved CPT-based correlations for prediction of the likelihood of “triggering” or initiation of soil liquefaction during earthquakes. Important advances over …

Gis Mapping For Irrigation District Rapid Appraisals, Daniel Howes, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

Geographic information system (GIS) mapping is slowly becoming commonplace in irrigation districts as the need for more accurate and organized data becomes increasingly important. The Irrigation Training and Research Center (ITRC) at California Polytechnic State University, San Luis Obispo commonly uses GIS as a tool in technical assistance packages for irrigation districts. One of the challenges in developing a strategic irrigation district modernization plan is to organize spatial data in such a way that various options can be easily understood. ITRC uses a combination of commercially available software with web-downloadable maps and photographs to organize and present the spatial information. …

Implementing An Integrated Signaling And Power Distribution Control System For Remotely Located Devices, Andrew Stephen Hintz

Graduate Theses - Electrical and Computer Engineering

A system was designed and implemented that combined the distribution of high-current power with a digital control signal over a common conductor. Two different versions of this system were implemented. Initially, a design based on of commercially available parts was created and tested to prove that the concept of combining communications and power is valid. The resulting design was then miniaturized to show that the system might be combined onto a single integrated circuit. In the miniaturization process, some circuit blocks were redesigned to take advantage of the flexibility provided by ASIC designs. Both the proof of concept and the …