Engineering Commons^™

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823: Task 10, First Quarter Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The objective of this task is to evaluate the elevated temperature tensile properties of Alloy EP-823, a leading target material for accelerator-driven waste transmutation applications. The test material will be thermally treated prior to evaluation of its tensile properties at temperatures relevant to the transmutation applications. The deformation characteristics of tensile specimens, upon completion of testing, will be evaluated by surface analytical techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The overall results are expected to provide a mechanistic understanding of high-temperature deformation behavior of Alloy EP-823 as a function of heat treatment.

Highlights of Accomplishment

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Inferring Liquid Chaotic Dynamics In Bubble Columns, M. Cassanello, F. Larachi, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experiments Carried Out to Study the Liquid Displacements in Bubble Columns Via the Computer Automated Radioactive Particle Tracking Technique Are Analyzed by Means of Lagrangian and Qualitative Dynamics Tools. the Lagrangian Approach Yields the Detailed Motion Sequences of the Tracer as Entrained by the Fast Ascending Bubbles or by the Liquid Flow Alongside the Column Walls. the Qualitative Dynamics Tools, on the Other Hand, Provide Prima Facie Corroboration of Chaos in Liquid Motion based on an Analysis of the Volume-Averaged Kolmogorov Entropy and the Mutual Information Function. Other Features of the Chaotic Motion, the Reconstructed Attractors and the Radial and …

Is There Synchronicity In Nitrogen Input And Output At The Noland Divide Watershed, A Small N-Saturated Forested Catchment In The Great Smoky Mountains National Park, H. Van Miegroet, I. F. Creed, N. S. Nicholas, David G. Tarboton, K. L. Webster, J. Schubzda, B. Robinson, J. Smoot, D. W. Johnson, S. E. Lindberg, G. Lovett, S. Nodvin, S. Moore

Civil and Environmental Engineering Faculty Publications

High-elevation red spruce [Picea rubens Sarg.]-Fraser fir [Abies fraseri (Pursh.) Poir] forests in the Southern Appalachians currently receive large nitrogen (N) inputs via atmospheric deposition (30 kg N ha(-1) year(-1)) but have limited N retention capacity due to a combination of stand age, heavy fir mortality caused by exotic insect infestations, and numerous gaps caused by windfalls and ice storms. This study examined the magnitude and timing of the N fluxes into, through, and out of a small, first-order catchment in the Great Smoky Mountains National Park. It also examined the role of climatic conditions in causing interannual variations in …

Electrical Activation Studies Of Ion Implanted Gallium Nitride, James A. Fellows

Theses and Dissertations

A comprehensive and systematic electrical activation study of Si-implanted GaN was performed as a function of ion implantation dose, anneal temperature, and implantation temperature. Additionally, Mg-implanted GaN was also investigated. Temperature-dependent Hall effect measurements and photoluminescence (PL) spectra were used to characterize the samples. GaN wafers capped with AlN were implanted with Si ions at doses ranging from 1x10¹³ to 5x10¹⁵ cm^-2 and annealed from 1050 to 1350 °C. The optimum anneal temperature for samples implanted with the higher Si doses is around 1350 °C, exhibiting nearly 100% electrical activation efficiency. Exceptional mobilities and carrier concentrations were …

Modeling, Fabrication, And Optimization Of Niobium Cavities – Phase I: Quarterly Progress Report August 20, 2001 - November 20, 2001, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Multipacting is one of the major loss mechanisms in rf superconductivity cavities for accelerators. This loss mechanism limits the maximum amount of energy/power supported by the cavities. Optimal designs have been identified in others’ studies. In practice, these designs are not easily manufactured. Chemical etching processes used to polish the cavity walls result in a nonuniform surface etch. A nonuniform surface etch will leave some unclean areas with contaminants and micron size particles. These significantly affect mutipacting. Further, a nonuniform etch will leave areas with damaged grain structure, which is not good for superconducting properties. Typically, the depth of chemical …

Innovation In Space: University Programs, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Innovation in Space: University Programs" on November 15, 2001.

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

We examined stainless samples that were exposed to LBE in experiments conducted by the Russians, under contract to Los Alamos. We examined both corroded and uncorroded samples using the Scanning Electron Microscope (SEM), the Energy Dispersive X-Ray (EDAX) Spectroscopy, and the X-ray Photoelectron Spectrometer (XPS). We found that the surface of the corroded sample is covered by oxygen-containing compounds, presumably mostly iron oxide. In samples exposed for shorter times or lower temperatures, we found that some areas were covered by an oxide layer, and some areas was uncovered. We found that the level of Cr in the uncovered area is …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report August 16,2001- November 15, 2001, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application.

Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 8/16/01- 11/15/01, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

The AAA program is developing technology for the transmutation of nuclear waste to address many of the long-term disposal issues. An integral part of this program is the proposed chemical separations scheme.

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 …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 8/16/01- 11/15/01, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible. The process involves evacuation of the furnace. The evacuation of the furnace also evacuates quartz rods used as fuel pin molds. Once evacuated the open ends of the molds are lowered into the melt; the casting furnace is then rapidly pressurized, forcing the molten metal up into the evacuated molds where solidification occurs.

This process works well …

Industry Guide To Selecting The Best Residential Window Options For The Florida Climate (Revised), Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

It used to be said that windows are little more than holes in the insulation. It is true to some extent that poorly insulated and drafty windows in certain climates defeat the purpose of wall insulation. However, modern high performance windows are almost as good as opaque insulated wall sections, at least in terms of total energy savings over long periods of time. In some cases, they can be shown to actually out-perform insulated walls. Of course, they have the priceless additional benefits of providing views to the outdoors and natural daylight illumination indoors important issues of quality and comfort. …

Phad: Packet Header Anomaly Detection For Identifying Hostile Network Traffic, Philip K. Chan, Matthew V. Mahoney

Electrical Engineering and Computer Science Faculty Publications

We describe an experimental packet header anomaly detector (PHAD) that learns the normal range of values for 33 fields of the Ethernet, IP, TCP, UDP, and ICMP protocols. On the 1999 DARPA off-line intrusion detection evaluation data set (Lippmann et al. 2000), PHAD detects 72 of 201 instances (29 of 59 types) of attacks, including all but 3 types that exploit the protocols examined, at a rate of 10 false alarms per day after training on 7 days of attack-free internal network traffic. In contrast to most other network intrusion detectors and firewalls, only 8 attacks (6 types) are detected …

Non-Repressing Carbon Sources For Alcohol Oxidase (Aoxi) Promoter Of Pichia Pastoris, Mehmet İnan, Michael M. Meagher

Papers in Biochemical Engineering

The growth of Pichia pastoris in a mixture of either glycerol or glucose and methanol follows a diauxic growth, with C1, utilizing enzymes being repressed. Therefore, these carbon sources can not be used as a mixture with methanol to simultaneously grow P. pastoris and induce C1, utilizing enzymes, especially in shake flask cultures of AOX-deficient P. pastoris. Among the alternative carbon sources tested, alanine, sorbitol, mannitol and trehalose, did not repress β-gal production when methanol was used as an inducer in mut- strain of P. pastoris. Our results show that either one of alanine, sorbitol, …

Evaporation Estimates For Irrigated Agriculture In California, Charles M. Burt, Daniel J. Howes, Andrew Mutziger

BioResource and Agricultural Engineering

All California irrigation districts that receive either federal or state water are now required to prepare Water Conservation Plans. For the first time in the history of most districts, they are developing an elementary water balance. The term "elementary" should be emphasized, because there are significant weaknesses in our knowledge of subsurface flows and some components of Evapotranspiration (ET). Irrigation districts generally use published "typical" values of ET for their water balance computations.

A Generalized Framework For Reasoning With Angular Directions, Mitra Debasis

Electrical Engineering and Computer Science Faculty Publications

This extended abstract presents a new scheme for qualitative reasoning with directions between points in 2D-space, called Star-ontology(6). The current results of our study on the complexity issues for reasoning with incomplete/disjunctive information using this new ontology has been outlined here. We have also proposed a generalized framework Star-ontology(a) for an integer a, that could be specialized to many ontologies including some of the known ones like the 2D-Cradinal ontology for a=4, and the currently studied one for a=6. This generalization also points to an interesting direction for investigation in the field of spatio-temporal reasoning.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 3, November 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Acuta Enews November 2001, Vol.30, No. 11

ACUTA Newsletters

In This Issue

Tornado Strikes Maryland Campus

Thanks to Exhibitors for 2001

ACUTA Events

DC Update

IT Disasters Recovery Near the World Trade Center

Board Report

Business Continuity Planning in Higher Ed

Welcome New Members

Positions Available

A Study Of Muscle Activation In A Mathematical Model Of The Human Head And Neck, Janet Brelin-Fornari, A. Arabyan

Crash Safety Center Publications

A model of the human head and neck that incorporates active and passive muscles is utilized in the analysis of non-impact loading in high “g” environments. The active muscles have the capability to be activated partially and in different combinations.The model is implemented in MADYMO using lumped parameters and Hill muscles. A comparison of simulation results with experimental data, generated by the Naval Biodynamics Laboratory (NBDL) for neck flexion and rebound, shows excellent agreement for a 15g impulsive load.

Moisture Problems In Manufactured Housing: Probable Causes And Cures, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

A significant number of new manufactured houses built to HUD code and located in the hot, humid Southeast are experiencing moisture problems. Soft wallboards, buckled floors, damaged wood molding and extensive mold growth are the most common symptoms. These problems do not respond to the standard service and repair strategies for water intrusion

At the request of four manufacturers, over twenty-five such moisture damaged homes were investigated in 1999 and 2000 to determine likely causes. One time blower door, duct tightness and pressure differential measurements were performed on all homes. Field data on ambient, crawlspace, belly and house temperatures and …

Representation, Elicitation, And Aggregation Of Uncertainty In Risk Analysis - From Traditional Probabilistic Techniques To More General, More Realistic Approaches: A Survey, Scott Ferson, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.

A Realistic (Non-Associative) Logic And A Possible Explanations Of 7+-2 Law, Raul A. Trejo, Vladik Kreinovich, I. R. Goodman, Jesus Martinez, Reginaldo Gonzalez

Departmental Technical Reports (CS)

When we know the subjective probabilities (degrees of belief) p1 and p2 of two statements S1 and S2, and we have no information about the relationship between these statements, then the probability of S1&S2 can take any value from the interval [max(p1+p2-1,0),min(p1,p2)]. If we must select a single number from this interval, the natural idea is to take its midpoint. The corresponding "and" operation p1&p_2=(1/2)(max(p1+p2-1,0)+min(p1,p2)) is not associative. However, since the largest possible non-associativity degree |(a&b)&c-a&(b&c)| is equal to 1/9, this non-associativity is negligible if the realistic "granular" degree of belief have granules of width <=1/9. This may explain why humans are most comfortable with <=9 items to choose from (the famous "7 plus minus 2" law).

We also show that the …

Ultrasonic Pulse Velocity In Concrete Using Direct And Indirect Transmission, Ismail Ozgur Yaman, Gokhan Inci, Nazli Yesiller, Haluk M. Aktan

Civil and Environmental Engineering

The relationship between velocities of ultrasonic stress waves transmitted along direct and indirect paths was investigated. Tests were conducted on plain concrete slabs of dimensions 1000 x 1500 mm, with a thickness of 250 mm. Direct ultrasonic wave transmission tests were conducted between top and bottom surfaces of the slabs and indirect tests were conducted along the slab surface. A test procedure, described in BS 1881 to determine indirect wave velocities, was refined by defining the number and spacing of transducers. Comparisons were made between direct and indirect wave velocity measurements using statistical analysis. The statistical analysis revealed that direct …

Design Of An Fpga-Based High-Speed Filter-Decimator For The Gifts Imaging Interferometer, Scott E. Budge, Charles R. O'Brien

Electrical and Computer Engineering Faculty Publications

This paper presents the design of an FPGA-based frame filter-decimator for the geostationary imaging Fourier transform spectrometer (GIFTS). The decimator reduces samples from two 128/spl times/128 sample imaging arrays from 1638.4 fps to 102.4 complex fps for the long wave IR (LWIR) band and from 1638.4 fps to 204.8 complex fps for the medium wave IR (MWIR) band. The design uses a novel parallel pipeline architecture to handle the bandpass sampling and decimation of the 16 k array samples which arrive a frame-at-a-time. The design is challenging because of significant speed, size, weight and power restrictions for satellite implementation.

A Fast Full-Search Adaptive Vector Quantizer For Video Coding, Scott E. Budge, Christian B. Peel

Electrical and Computer Engineering Faculty Publications

This paper presents a novel VQ structure which provides very good quality encoding for video sequences and exploits the computational savings gained from a fast-search algorithm. It uses an adaptive-search, variable-length encoding method which allows for very fast matching of a wide range of transmission rates. Both the encoding quality and the computational benefits from the fast-search algorithm are presented. Simulations show that full-search tree residual VQ (FTRVQ) can provide up to 3 dB improvement over a similar RVQ encoder on video sequences.

29th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 29th Conference on Senior Engineering Design Projects was held on November 27, 2001 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Dc Power-Bus Modeling And Design With A Mixed-Potential Integral-Equation Formulation And Circuit Extraction, Jun Fan, James L. Drewniak, Hao Shi, James L. Knighten

Electrical and Computer Engineering Faculty Research & Creative Works

Application of a circuit extraction approach based on a mixed-potential integral equation formulation (CEMPIE) for dc power-bus modeling in high-speed digital designs is detailed herein. Agreement with measurements demonstrates the effectiveness of the approach. Dielectric losses are included into the calculation of Green's functions, and thus, incorporated into the rigorous first principles formulation. A SPICE model is then extracted from the discretized integral equation. A quasistatic approximation is used for Green's functions to keep the extracted circuit elements frequency independent. Previous work has established a necessary meshing criterion in order to ensure accuracy for a given substrate thickness and dielectric …

Mechanical, Geometrical, And Electrical Characterization Of Silicon Membranes For Open Stencil Masks, E. Sossna, A. Degen, I. W. Rangelow, M. Drzik, P. Hudek, T. E. Tiwald, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Silicon membranes are used for stencil masks which are key to charged particle projection lithography, particularly for ion projection lithography, electron beam projection. Quantitative and qualitative determination of the mechanical properties of the true thickness, thickness variations (morphology), electrical conductivity and stress is critical to the development of next generation lithography. The metrology setup includes high accuracy thickness, refractive index and electrical conductivity measurement based on infrared variable angle spectroscopic ellipsometry, thickness variation characterization based on the Fizeau interferometric scheme and mechanical stress evaluation based on a novel double bulging technique.

Monitoring Subsurface Drainage Flow At Remote Locations, Stephen R. Workman, Stephen F. Higgins, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Laboratory evaluations and field results are presented for a slotted weir used to measure discharge from subsurface drains. The head–discharge curve for the vertical slot is a simple power function with an exponent of 1.5. There was excellent agreement (r² > 0.99 and 1:1 slope) between predicted and observed discharge in laboratory testing of 12 test weirs representing five slot widths. The primary advantages of the vertical slot weir are its simplicity, ease of maintenance, and ability to measure small flow rates. Disadvantages include a tendency for the slot to close a small amount over time as a result of …

Practical Issues For The Application Of High-Performance Concrete To Highway Structures, John J. Myers, Yumin Yang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In recent years, the advantages of high-performance concrete (HPC) have been well documented. Among others, these advantages include enhanced design flexibility and improved durability performance that results in reduced maintenance costs and an increased service life. Despite these obvious benefits, the implementation of HPC has been very slow. This can be attributed to several factors including the uncertainty related to current design codes and a lack of familiarity of designers and contractors with practices and requirements for proper design and construction of high-performance concrete structures. This paper introduces and discusses several fundamental issues that affect the implementation of HPC and …

Pickup And Delivery Problem With Time Windows: Algorithms And Test Case Generation, Hoong Chuin Lau, Zhe Liang

Research Collection School Of Computing and Information Systems

In the pickup and delivery problem with time windows (PDPTW), vehicles have to transport loads from origins to destinations respecting capacity and time constraints. In this paper, we present a two-phase method to solve the PDPTW. In the first phase, we apply a novel construction heuristics to generate an initial solution. In the second phase, a tabu search method is proposed to improve the solution. Another contribution of this paper is a strategy to generate good problem instances and benchmarking solutions for PDPTW, based on Solomon's benchmark test cases for VRPTW. Experimental results show that our approach yields very good …