Engineering Commons^™

Accuracy Of Scatterometer-Derived Winds Using The Cramer-Rao Bound, David G. Long, Travis E. Oliphant

Faculty Publications

A wind scatterometer makes measurements of the normalized radar-backscatter coefficient O of the ocean surface. To retrieve the wind, a geophysical model function (GMF), which relates O to the near-surface wind, is used. The wind vector can be estimated using maximum-likelihood techniques from several O measurements made at different azimuth angles. The probability density of the measured O is assumed to be Gaussian with a variance that depends on the true O and therefore, depends on the wind through the GMF. With this model for wind estimation, the Cramer-Rao (C-R) bound is derived for wind estimation, and its implications for …

Helical Single-Lamellar Crystals Thermotropically Formed In A Synthetic Nonracemic Chiral Main-Chain Polyester, Christopher Y. Li, Donghang Yan, Stephen Z. D. Cheng, Feng Bai, Jason J. Ge, Bret H. Calhoun, Tianbai He, Liang-Chy Chien, Frank W. Harris, Bernard Lotz

College of Polymer Science and Polymer Engineering

Phase structures and transformation mechanisms of nonracemic chiral biological and synthetic polymers are fundamentally important topics in understanding their macroscopic responses in different environments. It has been known for many years that helical structures and morphologies can exist in low-ordered chiral liquid crystalline (LC) phases. However, when the chiral liquid crystals form highly ordered smectic liquid crystal phases, the helical morphology is suppressed due to the crystallization process. A double-twisted morphology has been observed in many liquid crystalline biopolymers such as dinoflaggellate chromosomes (in Prorocentrum micans) in an in vivo arrangement. Helical crystals grown from solution have been reported in …

Mri Techniques For Cardiovascular Imaging, Roderic I. Pettigrew, John N. Oshinski, George P. Chatzimavroudis, W. Thomas Dixon

Chemical & Biomedical Engineering Faculty Publications

Over the last several years, cardiovascular MRI has benefited from a number of technical advances which have improved routine clinical imaging techniques. As a result, MRI is now well positioned to realize its longstanding promise of becoming the comprehensive cardiac imaging test of choice in many clinical settings. This may be achieved using a combination of basic advanced techniques. In this overview, the basic cardiac MRI techniques which are clinically useful are reviewed, and the recent technical advances which are clinically promising are described. These advances include routine black blood and cine bright blood techniques that are high speed (slice), …

1999 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to establish 1999 safety belt and child safety seat usage rates in Kentucky. The 1999 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994. Data were collected at 200 sites spread across Kentucky. Data from the individual sites were combined into a statewide percentage considering function classification, geographic region, and vehicle miles traveled.

The data show that the usage rate increased in 1999 after a few years where the rate had remained at a stable level below the highest value which occurred in 1994 immediately after …

Evaluation Of The Adaptir System For Work Zone Traffic Control, Kenneth R. Agent

Kentucky Transportation Center Research Report

The ADAPTIR system (Automated Data Acquisition and Processing of Traffic Information in Real Time) uses variable message signs (VMS) equipped with radar units, along with a software program to interpret the data, to display appropriate warning and advisory messages to motorists approaching a work zone when certain speed and delay thresholds are met. The overall conclusion of the evaluation is that the ADAPTIR type system is an effective method to provide real time information to motorists approaching a work zone. The information relates to speed reductions, delay, and possible diversions. Drivers who traveled through the work zone when the VMS …

The Energetics Of A Bouncing Ball, Warren A. Turner, Glenn W. Ellis

Engineering: Faculty Publications

Computer-based, real-time data collection is used to explore the energetics of a bouncing ball. Discussion centers around student comprehension and misconceptions surrounding interconversion of mechanical energy and the pedagogical use of this experiment.

Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu

Electro-Optics and Photonics Faculty Publications

A 16 X 16 Crossover photonic switching network with hybrid integrated CMOS/SEED smart pixel device and 2D optical fiber bundle array I/O access device is reported in this paper. SEEd array devices ar used as light receivers and transmitters, while CMOS devices make efficient logical processing. 4 X 40 2D multilayer optical fiber bundle arrays are fabricated and are used as I/O access devices in the crossover photonic switching network. The center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125micrometers , and the spacing between adjacent layers is 250micrometers . Displacing …

Bs News

Building Services Engineering

No abstract provided.

The Relationship Between Basic Multicellular Unit Activation And Origination In Cancellous Bone, C. J. Hernandez, S. J. Hazelwood, R. B. Martin

Biomedical Engineering

Activation frequency is often used as a measure of basic multicellular unit (BMU) activity in cancellous bone. However, activation frequency expresses the rate of BMU appearance in a histologic slide and not the rate of origination, which is a more physiologic indicator of remodeling activity and is necessary for the development of BMU-level bone remodeling simulations. Using identical assumptions to those for calculating the activation frequency, it is shown that the origination frequency in cancellous bone is equal to the activation frequency divided by the total distance traveled by the BMU and its width.

Optimization Of Solid-State Fermentation Parameters For The Production Of Xylanase By Trichoderma Longibrachiatum On Wheat Bran In A Forced Aeration System, Elizabeth R. Ridder, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 …

Runoff From Fescue Plots Treated With Trimec, Cristopher G. Moss, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams

Biosystems and Agricultural Engineering Faculty Publications

Runoff of herbicides can promote adverse impacts in receiving waters. The objective of this study was to assess the effects of rainfall delay, herbicide application rate, rainfall intensity, and pre-application rainfall on runoff of TRIMEC (a combination of 2,4-D, dicamba, and mecoprop), a herbicide that is commonly used in central Kentucky. The levels of rainfall delay were 0, 2, and 4 d following application; and the levels of herbicide application rate were 0, 0.5, 1 and 2 times the recommended rate. Simulated rainfall was applied at intensities of 64, 102, and 140 mm h^-1; and the depths of …

Guideline Policy For Snow And Ice Control, Aaron W. Braun, Dirk J. Medema

Indiana Local Technical Assistance Program (LTAP) Publications

These Guidelines are a compilation of information given by several agencies, such as the National Cooperative Highway Research Program, the Salt Institute, American Public Works Association, AASHTO, and many others.

Our goal was to was to gather all the information that could be useful for the Indiana Counties and Cities, add our own experience and expertise, and place it in one report.

These Guidelines are Divided into three sections. The first section is the Guidelines. It gives information and suggestions on all aspects of snow and ice control. The second section is a template for a snow and ice control …

Piezoelectric Doping In Alingan/Gan Heterostructures, M. Asif Khan, J. W. Yang, Grigory Simin, R. Gaska, M. S. Shur, A. D. Bykovski

Faculty Publications

We report on the piezoelectricdoping and two-dimensional (2D) electron mobility in AlInGaN/GaN heterostructures grown on 6H–SiC substrates. The contribution of piezoelectricdoping to the sheet electron density was determined using an In-controlled built-in strain-modulation technique. Our results demonstrate that in strained AlGaN/GaN heterostructures, the piezoelectric field generates at least 50% of the 2D electrons. The strain modulation changes the potential distribution at the heterointerface, which, in turn, strongly affects the 2D electron mobility, especially at cryogenic temperatures. The obtained results demonstrate the potential of strain engineering and piezoelectricdoping for GaN-based electronics.

Low-Frequency Noise In N-Gan With High Electron Mobility, M. E. Levinshtein, S. L. Rumyantsev, D. C. Look, R. J. Molnar, M. Asif Khan, Grigory Simin, V. Adivarahan, M. S. Shur

Faculty Publications

We report on the results of measurements of low frequency noise in n-type gallium nitride (GaN) grown on sapphire with 300 K electron mobility of 790 cm²/V s. The noise spectra have the form of 1/f noise with a Hooge parameter α of approximately 5×10⁻². This value of α is two orders of magnitude smaller than that observed before in n-GaN. The obtained results show that the level of flicker noise in GaN, just like that in GaAs and Si, strongly depends on the structural perfection of the material (the amplitude of the 1/f …

Supervisory Control And Data Acquisition Experiment Using The Advanced Communications Technology Satellite - Lessons Learned, Florida Solar Energy Center, Carol Emrich

FSEC Energy Research Center®

Satellite Supervisory Control and Data Acquisition (SCADA) of a Photovoltaic (PV)/diesel hybrid system was tested using NASA's Advanced Communication Technology Satellite (ACTS) and Ultra Small Aperture Terminal (USAT) ground stations. The setup consisted of a custom-designed PV/diesel hybrid system, located at the Florida Solar Energy Center (FSEC), which was controlled and monitored at a remote hub via Ka-band satellite link connecting two USATs in a SCADA arrangement. The robustness of the communications link was tested for remote monitoring of the health and performance of a PV/diesel hybrid system, and for investigating load control and battery charging strategies to maximize battery …

Opal Press Release: October 28, 1999, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A press release written by Professor Bob Twiggs titled "Opal Press Release: October 28, 1999."

Gauge Repeatability & Reproducibility Study For A 3-D Solder Paste Inspection System, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Due to the increased use of Ball Grid Arrays (BGAs) and fine pitch and ultra fine pitch Quad Flat Packages (QFPs), there is a dramatic increase in demand for solder paste inspection after the stencil printing process. The important response variables of the printing process are deposited solder paste volume, area, height and position. To identify and remove defects at the earliest possible process step, a 3-D solder paste inspection system should be used to monitor solder paste deposited on all pads on every board before component placement. An example is a fully automatic laser-based 3-D triangulation solder paste inspection …

Preparation Of Monolithic Carbon Fiber Composite Material, Geoffrey M. Kimber

Center for Applied Energy Research Faculty Patents

A process for preparing an activated carbon fiber composite material includes the steps of mixing carbon fibers, binder and water to form a slurry, molding the slurry to produce a green monolithic body, curing the monolithic body, carbonizing the cured monolith to produce a carbon fiber composite with an open, permeable structure and activating the composite. If pre-activated carbon fibers are utilized in the mixing step the carbonizing and activating steps are eliminated.

Letters To The Editor: Filtering Property Of A Lightly Damped System, Subjected To Transient Excitation, M. F. Dimentberg, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

No abstract provided.

Methods Of Fabricating Plasticized, Antiplasticized And Crystalline Conducting Polymers And Precursors Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Methods of forming materials containing precursors to electrically conductive polymers and electrically conductive polymers are described which have a high degree of crystallinity. The high degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. High levels of electrical conductivity are achieved in in the electrically conductive materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriented film which has isotropic electrical conductivity. In the preferred embodiment, additives …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high volume surface mount assembly. Control of the amount of solder paste deposited is critical for fine pitch and ultra-fine pitch SMT assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% of SMT defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the deposited solder paste volume, area, and height. An experiment was conducted to investigate the effects of relevant process parameters on the amount of …

Coulomb Crystals And Glasses For Self-Assembly Of Nanoparticles, P. F. Williams, A. Belolipetski, A. Goussev, M. E. Markes

P. F. (Paul Frazer) Williams Publications

Under proper conditions, small particles may be suspended in a regularly-spaced array called a Coulomb crystal. In this paper we discuss the application of this phenomenon to the self-assembly of nanoparticles in a lattice-lie array on a substrate. Issues associated with depositing the particles, and the size and lattice spacing of the particles are discussed.

Current Canal Modernization From An International Perspective, Charles M. Burt

BioResource and Agricultural Engineering

Modernization differs from rehabilitation, which simply returns a deteriorated project or structures to their original new state. Rehabilitation by itself typically only perpetuates the vicious cycle of rehabilitation, deterioration, rehabilitation, etc. A modern irrigation design is the result of a thought process that selects the configuration and the physical components in light of a well-defined and realistic operation plan that is based on the service concept. A modern irrigation design is not defined by specific hardware components and control logic. Advanced concepts of hydraulic engineering, irrigation engineering, agronomy, and social science should be used to arrive at the most simple …

Case Study: Modernization Of The Government Highline Canal, Stuart W. Styles, Charles M. Burt, Ram Dhan Khalsa, Robert Norman

BioResource and Agricultural Engineering

The Government Highline Canal Modernization Study was completed to evaluate options for reducing the flow rate requirement of the Government Highline Canal during the late Summer and Fall water delivery months. The intent was to develop a design for which Colorado River diversions could be better matched to on-farm demands. The two primary challenges associated with reducing diversions are that (i) at low canal flows many turnouts do not have sufficient pressure, and (ii) it is difficult to schedule diversions to match deliveries. The Government Highline Canal is part of the federal Grand Valley Project in the Colorado River Basin …

Modernization Of The Delano-Earlimart Irrigation District, Charles M. Burt, Dale R. Brogan

BioResource and Agricultural Engineering

Delano-Earlimart Irrigation District (DEID) delivers water through closed reinforced concrete pipelines on an arranged schedule. Farmers are not allowed to operate their own turnouts, and individual turnout flow rate changes impact flow rates at all other turnouts on the same pipeline. DEID is in the process of a complete modernization program which will allow the farmers to operate their own turnouts on a very flexible arranged schedule. The modernization includes (i) a new water ordering program, (ii) new turnout designs with pressure regulators and new flow propeller flow meters, (iii) the use of hand held data recorders to document deliveries …

Case Study: Modernization Of The Patterson Irrigation District, Stuart W. Styles, Charles M. Burt, Mike Lehmkuhl, John Sweigard

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) at Cal Poly in San Luis Obispo, California has been working in conjunction with the Patterson Irrigation District (PID) on modernization of the district facilities. This project is being partially funded by the United States Bureau of Reclamation (USBR) Mid-Pacific Region. The district is located in the San Joaquin Valley of California. Water supply for the district is pumped primarily from the San Joaquin River. The district utilizes a series of pump stations and canal pools to bring water uphill to supply the lateral canals, which are laid out on the contour. Modernization …

Carrier Concentration And Lattice Absorption In Bulk And Epitaxial Silicon Carbide Determined Using Infrared Ellipsometry, Thomas E. Tiwald, John A. Woollam, Stefan Zollner, Jim Christiansen, R. B. Gregory, T. Wetteroth, S. R. Wilson, Adrian R. Powell

Department of Electrical and Computer Engineering: Faculty Publications

We have measured the dielectric function of bulk nitrogen-doped 4H and 6H SiC substrates from 700 to 4000 cm^-1 using Fourier-transform infrared spectroscopic ellipsometry. Photon absorption by transverse optical phonons produces a strong reststrahlen band between 797 and 1000 cm^-1 with the effects of phonon anisotropy being observed in the region of the longitudinal phonon energy (960 to 100 cm^-1). The shape of this band is influenced by plasma oscillations of free electrons, which we describe with a classical Drude equation. For the 6H-SiC samples, we modify the Drude equation to account for the strong effective …

Opal Microsatellite, Greg Hutchins

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Greg Hutchins on the "OPAL Microsatellite" from October 8, 1999.

A Defect In Interleukin 12-Induced Activation And Interferon Gamma Secretion Of Peripheral Natural Killer T Cells In Nonobese Diabetic Mice Suggests New Pathogenic Mechanisms For Insulin-Dependent Diabetes Mellitus., Marika Falcone, Brian Yeung, Lee Tucker, Enrique Rodriguez, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The function of natural killer T (NKT) cells in the immune system has yet to be determined. There is some evidence that their defect is associated with autoimmunity, but it is still unclear how they play a role in regulating the pathogenesis of T cell-mediated autoimmune diseases. It was originally proposed that NKT cells could control autoimmunity by shifting the cytokine profile of autoimmune T cells toward a protective T helper 2 cell (Th2) type. However, it is now clear that the major function of NKT cells in the immune system is not related to their interleukin (IL)-4 secretion. In …

Student Space Program: Stanford University, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Student Space Program: Stanford University" from October 3, 1999.