Engineering Commons^™

Test 1744: John Deere 8100t Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Investigation Of A Complex Reaction Network: Ii. Kinetics, Mechanism And Parameter Estimation, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković, S. K. Chou, G. Ahmed, R. Kahney

Chemical and Biochemical Engineering Faculty Research & Creative Works

Conventional Strategies for Discrimination of Intrinsic and Apparent Kinetics from Crushed- and Whole-Catalyst-Pellet Experimental Data, Respectively, Do Not Yield Satisfactory Results for the Reaction Network in the Manufacture of Α-Aminomethyl-2-Furanmethanol (Aminoalcohol) from Α-Nitromethyl-2-Furanmethanol (Nitroalcohol). Laboratory Trickle-Bed Reactor Tests in the Range of Concentration and Product Yield of Commercial Interest Are Utilized to Yield a Reasonable Set of Kinetic Parameters, Which Are Otherwise Unobtainable. This is Accomplished by Proposing a Reaction Network, a Plausible Mechanism, and Optimizing the Kinetic Parameters based on the Reactor-Model-Generated Performance Data to Fit Experimental Output Concentrations of All Species for the Entire Set of Experiments. a …

Prediction Of Pressure Drop And Liquid Holdup In High-Pressure Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, M. R. Khadilkar, Y. Wu, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Holub Et Al. (1992, 1993) Phenomenological Model for Pressure Drop and Liquid Holdup in Trickle Flow Regime at Atmospheric Pressure Was Noted by Al-Dahhan and Duduković (1994) to Systematically Underpredict Pressure Drop at High Pressure and High Gas Flow Rates. in This Study, the Holub Et Al. (1992, 1993) Model Has Been Extended to Account for the Interaction between the Gas and Liquid Phases by Incorporating the Velocity and the Shear Slip Factors between the Phases. as a Result, the Prediction of Pressure Drop at the Operating Conditions of Industrial Interest (High Pressure) Has Been Improved Noticeably Without Any …

Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt

Civil & Environmental Engineering Faculty Publications

The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world's largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH …

Electromagnetic Beam Directing Means-Sample Analysis System Stage, And Method Of Use, Daniel W. Thomspon, Darin W. Glenn, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is an electromagnetic beam directing means for use with sample analysis systems, such as relfectometers, ellipsometers and polarimeters and the like, use of which facilitates investigation of sample systems which are not mounted to a sample analysis system sample system supporting stage. The present invention eliminates the requirement os extensice sample analysis system component realignment when alternatingly performing analysis of sample systems mounted upon, and mounted other than upon, a sample analysis system sample system supporting stage.

White Light Interferometric Surface Profiler, Vincent Toal, Brian Bowe

Articles

We describe an optical system for 3-D profilometry based on the white light interferometer. We detail a simple way to construct a profiler that uses two simple algorithms which deal efficiently and quickly with the data. The system has a theoretically unlimited range and can deal with rough and smooth surfaces

Performance And Robustness Issues In The Compensation Of Folpd Processes With Pi And Pid Controllers, Aidan O'Dwyer

Conference papers

This paper will discuss the compensation of first order lag plus time delay (FOLPD) processes using PI and PID controllers whose parameters are specified using appropriate tuning rules. The gain margin, phase margin and maximum sensitivity of the compensated system as the ratio of time delay to time constant of the process varies, are used as ways of judging the performance and robustness of the system.

The Gain Scheduled Piece-Wise Adaptive Digital Control Of A Ph Process, Eugene O'Shaughnessy, Aidan O'Dwyer

Conference papers

The compensation of a pH process is complicated by the non-linear nature of the process titration curve and the significant time delays that typically exist in such processes. This paper will propose the use of a gain scheduled piecewise adaptive PI controller to compensate the process. A pilot plant is controlled, with the control algorithm implemented on a programmable controller. SCADA software displays and trends the plant and controller signals.

A Comparison Of Some Low Cost Laminates For Antennas Operating In The 2.45 Ghz Ism Band, Max Ammann

Conference papers

An evaluation of some low-cost laminates suitable for microstrip patch antennas is presented. Criteria for the selection of substrates for antenna fabrication are given careful consideration. A coaxial-probe fed linearly-polarized rectangular microstrip patch operating at a frequency of 2.45 GHz was fabricated on four different low cost laminates. The substrates used were polyester, epoxy glass (FR-4), a ceramic filled PTFE composite and a woven glass-reinforced hydrocarbon and ceramic thermoset material. Material properties are discussed and the antenna performances are evaluated and compared to one fabricated on a thick glass-loaded microfiber PTFE substrate. An evaluation of some inexpensive microstrip antenna CAD …

Nonlinear Modeling Of Concrete-Filled Frp Tubes Using The Finite Element Method, Kenneth T. Zagers

Retrospective Theses and Dissertations

Fiber reinforced plastic (FRP) has in recent years emerged as an alternative reinforcement for structural concrete. The properties that make FRP appealing to the construction industry include its resistance to electro-chemical corrosion, high strength-to-weight ratio, and electrical insulation. An efficient use of FRP is in the form of concrete-filled tubes, where the tube not only protects the concrete against environmental factors, but also provides confinement and external reinforcement. Since use of fiber composites for confining concrete is relatively new, analytical work in this area is limited to the models that were originally developed for transverse steel reinforcement. However, it has …

Excitation Of The Whispering-Gallery-Modes At The Shielded Hemispherical Dielectric Resonator, Sergey Kharkovsky, V. V. Kutuzov, A. E. Kogut, V. A. Solodovnik

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Methods For Predicting Shale Durability In The Field, Paul Michael Santi, Jerry D. Higgins

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Durability of shales and other weak rock is an important parameter describing the material's susceptibility to breakdown upon exposure to water or during construction work. While laboratory methods have been developed to measure durability, no correlations between laboratory results and simple field tests have been determined. The results of this study show that certain field parameters can predict slake durability with acceptable accuracy. The recommended field tests, in order of desirability, are slake index, jar slake, hammer rebound, and NGI "Q" value. Single variable and multiple variable linear regression equations are given, including equations conservatively modified so that 95% of …

A Hybrid System For Well Test Analysis, Edward A. May, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Petroleum well test analysis is a tool for estimating the average properties of the reservoir rock. It is a classic example of an inverse problem. Visual examination of the pressure response of the reservoir to an induced flow rate change at a well allows the experienced analyst to determine the most appropriate model from a library of generalized analytical solutions. Rock properties are determined by finding the model parameters that best fit the observed data. This paper describes a framework for hybrid network to assist the analyst in selecting the appropriate model and determining the solution. The hybrid network design …

An Object-Based Evolutionary Algorithm: The Nesting Solution, Kanchitpol Ratanapan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

The nesting problems have received considerable attention and have been addressed by a variety of algorithms. Recently, evolutionary algorithms have been adopted for solutions. Most of these algorithms, however, require a search in one-dimensional space; thus a transformation of the problem to a single dimension, as in the sequencing problems, is needed. Unfortunately, this restricts the search space. In this study an object-based evolutionary algorithm for the nesting problems is proposed. The methodology is created in a true two-dimensional space, allowing object-based mechanisms and object-based evolutionary operators to perform effectively on the space without restricting search alternatives. Implementation of the …

Comparative Study Of Stock Trend Prediction Using Time Delay, Recurrent And Probabilistic Neural Networks, Donald C. Wunsch, Emad W. Saad, Danil V. Prokhorov

Electrical and Computer Engineering Faculty Research & Creative Works

Three networks are compared for low false alarm stock trend predictions. Short-term trends, particularly attractive for neural network analysis, can be used profitably in scenarios such as option trading, but only with significant risk. Therefore, we focus on limiting false alarms, which improves the risk/reward ratio by preventing losses. To predict stock trends, we exploit time delay, recurrent, and probabilistic neural networks (TDNN, RNN, and PNN, respectively), utilizing conjugate gradient and multistream extended Kalman filter training for TDNN and RNN. We also discuss different predictability analysis techniques and perform an analysis of predictability based on a history of daily closing …

Voice Recognition Using Neural Networks, Ganesh K. Venayagamoorthy, Viresh Moonasar, K. Sandrasegaran

Electrical and Computer Engineering Faculty Research & Creative Works

One solution to the crime and illegal immigration problem in South Africa may be the use of biometric techniques and technology. Biometrics are methods for recognizing a user based on unique physiological and/or behavioural characteristics of the user. This paper presents the results of ongoing work into using neural networks for voice recognition

A Novel Thin Film Transistor Using Double Amorphous Silicon Active Layer, Jong Hyuni Choi, Chang-Soo Kim, Byung Cheon Lim, Jin Jang

Electrical and Computer Engineering Faculty Research & Creative Works

We have fabricated a novel low off-state leakage current thin-film transistor (TFT) using a chlorine incorporated amorphous silicon [a-Si:H(:Cl)] and amorphous silicon (a-Si:H) stacked active layer, in which conduction channel is formed in a-Si:H and a-Si:H(:Cl) is photo-insensitive material. The off-state photo-leakage current of the a-Si:H(:Cl)/a-Si:H TFT is much lower than that a conventional a-Si:H TFT.

An Improved Method For Incorporating Magnetic Saturation In The Q-D Synchronous Machine Model, Keith Corzine, Brian T. Kuhn, S. D. Sudhoff, H. J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

An improved technique for incorporating saturation into the q-d axis model (Park''s model) of a synchronous machine is proposed. By choosing magnetizing flux linkage as a state variable, iterative procedures required by traditional methods are avoided. The saturation function is represented by an arctangent function which has some distinct advantages over polynomial representations and look-up tables. In particular, the parameters of the proposed function all have physical significance and the proposed function is defined over an infinite range of flux linkage. The model is verified for steady-state and transient conditions using a laboratory synchronous machine-rectifier system similar to those commonly …

Magnetoresistance Of Magnetic Tunnel Junctions In The Presence Of A Nonmagnetic Layer, Shi C. Zhang, P. M. Levy

Materials Science and Engineering Faculty Research & Creative Works

We find that electron propagation across a uniform nonmagnetic metallic layer di in a magnetically layered structure is coherent up to a critical length dc. This provides a possible explanation for the slow decay of the magnetoresistance of magnetic tunnel junctions when a layer of Cu or Ag is inserted between the magnetic electrode and the barrier. However, for many (most) structures the roughness of the interfaces breaks the coherence for di ≪ dc. While the loss of coherence is not fatal for the magnetoresistance of metallic multilayers, it is for tunnel junctions. The quantum well states arising from the …

Analysis Of The Value Of The Fe Examination For The Assessment Of Student Learning In Engineering And Science Topics, John L. Watson

Materials Science and Engineering Faculty Research & Creative Works

This paper presents the results of a project, which investigated the potential of fully using previously unreleased data from the nationally normed Fundamentals of Engineering (FE) examination to assess learning in key engineering and science topics. In the past, very limited information was released by the National Council of Examiners for Engineers and Surveyors (NCEES) for the eight hour FE examination, which is composed of 150-200 questions in ten morning and five afternoon topics. For the purposes of this project the NCEES agreed to release information to the University of Missouri-Rolla (UMR) to permit the value of the FE data …

Evolution Of In Situ Refractories In The 20th Century, William E. Lee, Robert E. Moore

Materials Science and Engineering Faculty Research & Creative Works

A common theme over the past 100 years in refractories science and technology has been to generate a protective refractories layer in a high-temperature container, often by reaction of the refractory materials with the contents (glass, slag, or atmosphere). The history of refractories during the 20th century is used in this review to illustrate how techniques - such as slag splashing, in situ spinel generation in castables, magnesia dense layer formation in magnesia-carbon brick in steelmaking, clinker adhesion in cement kilns, and viscous boundary layer generation in glass tanks - have evolved to their present status.

Organically Deposited Metallic Films For Device Fabrication, Thomas J. O'Keefe, M. Stroder, Matthew O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Advances in integrated circuit density, speed and complexity are dependent on lower resistance, finer line width on-chip interconnections. Methods for incorporating copper interconnects into IC fabrication processes have been developed which accomplish this objective but most of these methods use some form of blanket metal deposition that requires mechanical and/or chemical removal of excess material. To date, investigations into the selective deposition of conductor materials for device fabrication have met with limited success. A new process for selectively depositing metallic conductors using inexpensive, organic-based chemical solutions could potentially force a paradigm shift in the deposition of metals for microelectronic applications. …

Maskless, Direct Deposition Of Copper Onto Aluminum Bond Pads For Flip Chip Applications, M. Fang, Thomas J. O'Keefe, M. Stroder, W. Shih, Matthew O'Keefe, R. Strawser, D. Via

Materials Science and Engineering Faculty Research & Creative Works

Flip chip interconnection of integrated circuits (IC) for packaging applications such as direct chip attachment use Pb-Sn solders as the connection between the die and the substrate. Under bump metallization is typically used to transition from the non-solderable Al bond pad on the IC to a solderable surface such as copper using traditional blanket metal deposition, photolithography and etching procedures. In this study, we report for the first time the use of a novel process for selectively depositing adherent copper directly onto aluminum thin films, eliminating the need for adhesion promoting transition layers and additional patterning steps. Utilizing copper bearing …

On-Line Team Project Communication Tool Set, Halvard E. Nystrom, D. R. Risco

Engineering Management and Systems Engineering Faculty Research & Creative Works

Team projects offer a valuable mechanism for effective learning. However, communication within the team, with the instructor and between different teams is a challenging task that can greatly limit the effectiveness of the learning experience. Some of the tools and concepts that are being developed for distance learning applications can be used to enhance team project communication within teams that are geographically separated as well as for in-campus teams. This article documents a set of on-line tools that allow for asynchronous team participation and timely monitoring and feedback by the instructor.

A Transmission-Constrained Unit Commitment Method, Chung-Li Tseng, Chao-An Li, S. S. Oren, C. S. Cheng, A. J. Svoboda, R. B. Johnson

Engineering Management and Systems Engineering Faculty Research & Creative Works

The paper presents a transmission-constrained unit commitment method using a Lagrangian relaxation approach. The transmission constraints are modeled as linear constraints based on a DC power flow model. The transmission constraints, as well as the demand and spinning reserve constraints, are relaxed by attaching Lagrange multipliers. The authors take a new approach in the algorithmic scheme. A three-phase algorithm is devised including dual optimization, a feasibility phase and unit decommitment. A test problem involving more than 2500 transmission lines and 2200 buses is tested along with other test problems

A Robust Unit Commitment Algorithm For Hydro-Thermal Optimization, Chao-An Li, R. B. Johnson, A. J. Svoboda, Chung-Li Tseng, E. Hsu

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents a unit commitment algorithm which combines the Lagrangian relaxation (LR), sequential unit commitment (SUC), and optimal unit decommitment (UD) methods to solve a general hydro-thermal optimization (HTO) problem. We argue that this approach retains the advantages of the LR method while addressing the method''s observed weaknesses to improve overall algorithm performance and quality of solution. The proposed approach has been implemented in a version of PG&E''s HTO program, and test results are presented.

Placement Of Piezoelectric Actuators For Active Control Of Vibration Using Modal Parameters, Xuegeng Zhu

Mechanical & Aerospace Engineering Theses & Dissertations

An equation is derived to model the piezoelectric actuators incorporation with flexible structures. This equation permits the comparison of the performance indices over the entire structure for a piezoelectric actuator with constant area, which is unachievable if the Finite Element Method is used for complicated structures.

An index has been developed for placement of piezoelectric actuator for control of vibration of a flexible structure. This index is derived from the definition of H2norm. Computation of the proposed index requires only the natural frequencies and corresponding mode shapes of the structures of interest. The method is well suited to large …

The Effect Of A Baffle On Acoustic Radiation Directivity, Walter Eversman, Indranil Danda Roy

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An investigation is made of the effect of an artificial baffle introduced in Finite Element modeling of acoustic radiation from turbofan inlets. The purpose of the baffle is to limit the extent of the computational domain in order to maximize the efficiency of the scheme. However, the possibility exists that the baffle, if improperly oriented, will generate spurious reflections which interfere with the true radiated acoustic field. A generic example of a turbofan inlet, including typical geometry and non-uniform potential flow in and around the nacelle, is modeled with a baffle as typically introduced limiting the angular extent of the …

Aerodynamic Interference For Hypersonic Missiles At Low Angle Of Attack, Harlan F. Nelson, Derek G. Hillstrom

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A Euler code is used to predict the flow field over a hypersonic missile and to determine the carryover factors KW(B), fin lift in the presence of the body, and KB(W), lift produced by the body in the presence of the fins. The missile is assumed to have cruciform, delta fins in the + orientation and an aspect ratio of 1.529. Results are presented as a function of fin span at Mach 6, 8, and 10, for a 2-deg angle of attack. Two ratios of specific heats, 1.4 and 1.3, are considered to partially account for vibrational excitation effects. Both …

An Integrated Approach To Determining The Sequence Of Machining Operations For Prismatic Parts With Interacting Features, Alan C. Lin, Shou Yee Lin, Das Diganta, Wen F. Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper proposed a framework for integrating artificial intelligence (AI) techniques and mechanistic models in the task of generating process plans for prismatic parts. The main issue of process planning addressed in this paper is the determination of the operation sequence for mechanical parts containing interacting features where machining of one feature might adversely affect the surface quality of other features. The informed graph-search strategy in AI is used to achieve the function of operation sequence planning. The search graph is built by considering alternative machining operations in converting a blank stock into the final part configuration. Several heuristic functions …