Engineering Commons^™

Collagen Fibres Are Not Required For Initial Matrix Mineralization By Bone Cells, M. M. Hosseini, S. A. F. Peel, J. E. Davies

Cells and Materials

Passaged primary cultures of young adult rat bone marrow cells were maintained in medium containing combinations of the supplements dexamethasone, ascorbic acid and Na-ß-glycerophosphate. The cultures were examined by both light and scanning electron microscopy (with additional energy dispersive X-ray analysis). In cultures with fully supplemented medium, an extracellular matrix formed at the culture dish surface, beneath developing bone nodules; this matrix was mineralized but collagen-fibre free and corresponded to that which we have reported previously as the equivalent of the cement line in vivo. In selected samples this interfacial, cement line, matrix was analyzed by X-ray …

Physical And Biological Evaluation Of Hydroxylapatite Films Formed On Ti6a14v Substrates By Excimer Laser Ablation, Tatjana Dostálová, Miroslav Jelínek, Lucie Himmlová, Vlasta Pesáková, Milan Adam

Cells and Materials

Thin films of hydroxylapatite, about 500 nm, were formed on Ti6Al4V by excimer laser ablation. Ten different deposition conditions were used such as deposition atmosphere (vacuum, pure water vapor, mixture of Ar and water vapor), substrate temperature, target-substrate distance and energy density. Mechanical and physical analyses were carried out by Rutherford backscattering and particle induced X-ray emission; crystallinity of films was determined by X-ray diffraction, surface topography by scanning electron microscopy and adhesion by a scratch test. Biological evaluation of samples was also performed. The fibroblast proliferation test was used, morphological evaluation of macrophages was carried out, and the activity …

Albumin Affinity Biomaterial Surfaces, James R. Keogh, John W. Eaton

Cells and Materials

Recently, considerable progress has been made in designing biomaterial surfaces which possess enhanced albumin affinity. Two derivatization methods for producing albumin binding biomaterial surfaces, based on an albumin affinity dye, cibacron blue, have been developed. Both surface derivatization methods were found to enhance the binding of albumin to an implant grade polyetherurethane. Evaluations of the enhanced albumin affinity demonstrated the binding to be both selective and reversible. Surfaces having such enhanced albumin affinity were found to be minimally thrombogenic and to discourage the adhesion of bacteria which might otherwise cause device-centered infections. We conclude that albumin affinity surfaces, such as …

Biofilm Mediated Calculus Formation In The Urinary Tract, Robert J. C. Mclean, David J. Stickler, J. Curtis Nickel

Cells and Materials

Mineralization and subsequent calculus formation is a common complication of biofilm infections. In the urinary tract, these infected calculi often arise from infections by urease-producing bacteria. Ammonia, liberated by bacterial urease activity, increases urine pH, resulting in the precipitation of Ca and Mg as carbonateapatite {Ca₁₀(PO₄,CO₃)₆(OH,CO₃)₂} and struvite (NH₄MgP0₄·6H₂O). These minerals become entrapped in the organic matrix which surrounds the infecting organisms and ultimately grow into mature calculi. When the causative organisms grow on urinary catheters and stents, the resulting mineralization can …

Perturbations Of Periosteel Bone During Healing: Effect Of Non-Weight Bearing, Helen E. Gruber, Mary E. Kirchen, John R. Sweeney, William E. Anderson, G. June Marshall

Cells and Materials

Weight bearing (WB) is an important factor influencing bone remodelling. The present study evaluates the effects of weight bearing and non-weight bearing (S) (achieved by tail suspension and hindlimb elevation) on the healing of a fibular osteotomy in adult male rats. After 9, 18 or 36 days under WB or S conditions, periosteum near the callus formed at the osteotomy site was compared to periosteum of the contralateral fibula (which did not receive an osteotomy) or to periosteum of fibula of control animals which did not receive an osteotomy. Data show that periosteal bone healing is sensitive to alterations in …

A Composite Biomaterial: Poly 2 (Hydropoxyethyl) Methacrylate / Alkaline Phosphatase Initiates Mineralization In Vitro, R. Filmon, D. Chappard, J. P. Monthéard, M. F. Baslé

Cells and Materials

Bone substitutes are nowadays largely used in orthopedic surgery but they lack osteoinductive properties. Poly (2-hydroxyethyl methacrylate) (pHEMA) has numerous biomedical applications. Alkaline phosphatase (AlkP), an ectoenzyme elaborated by osteoblasts, initiates bone mineralization by hydrolyzing organic phosphates before calcium-phosphorus deposition. We have immobilized AlkP in pHEMA in a copolymerization technic. Histochemical study revealed that AlkP has retained its biological activity . Image analysis of sections using a tessellation method showed a lognormal distribution of the area of tessels around AlkP particles thus confirming an homogeneous distribution of the enzyme in the polymer. Pellets of pHEMA and pHEMA + AlkP were …

Validation Of Energy Dispersive X-Ray Spectrometry As A Method To Standardize Backscattered Electron Images Of Bone, E. G. Vajda, R. D. Bloebaum, J. G. Skedros

Cells and Materials

The use of backscattered electron (BSE) imaging as a tool for the qualitative measurement of mineral content in bone has been well documented. The challenge still remains to develop BSE imaging as a tool for quantitative mineral content analysis in bone. The limiting factor has been the ability to standardize the BSE signal within and between laboratories. Energy dispersive x-ray spectrometry (EDX) has been proposed as a method to standardize the BSE operating environment. The goal of this study is to investigate the relationship between EDX-determined wt.% Ca measurements and BSE graylevels. A comparison with traditional ash content measurements will …

The Effect Of Vitronectin And Other Extracellular Matrix Molecules On Endothelial Expansion And Plasminogen Activation, P. Anne Underwood, Penny A. Bean

Cells and Materials

Endothelial recovery following procedures used to alleviate blood vessel occlusion is modulated by the local extracellular matrix upon which it has to migrate and proliferate. This extracellular material is derived from vessel wall cells, and plasma proteins which bind to the exposed surfaces. We have demonstrated that vitronectin adsorbs efficiently to tissue culture polystyrene in competition with other plasma proteins, which suggests that it may adsorb to biomaterial surfaces in vivo. We have compared the adhesion, migration and proliferation of human umbilical artery endothelial cells on surface-coated vitronectin, with other extracellular matrix molecules encountered in this environment, namely fibronectin, …

Progress In The Smart Pixel Technologies, Harvard Scott Hinton

Electrical and Computer Engineering Faculty Publications

The purpose of this paper is to review the recent progress in the developing smart pixel technologies. The paper begins by reviewing some of the rapidly evolving smart pixel terminologies. It then describes several of the smart pixel technologies that have recently emerged. Finally, it outlines the performance of these technologies in both device complexity and aggregate capacity. The reviewed SPA technologies include both the modulator-based FET-SEED, hybrid CMOS-SEED, and LCOS smart pixels and the source-based hybrid VCSEL/MSM, ELO, flip-chip-bonded VCSEL/MSM, and monolithic MSM/MESFET/VCSEL smart pixels.

An Atm-Based Intelligent Optical Backplane Using Cmos-Seed Smart Pixel Arrays And Free- Space Optical Interconnect Modules, Dominic J. Goodwill, Kent E. Devenport, Harvard Scott Hinton

Electrical and Computer Engineering Faculty Publications

The architecture, smart pixel array chip design, and optical design of an intelligent free-space digital optical backplane for ATM switching are presented. The smart pixel chip uses reflective SEED (self-electrooptic effect device) optical modulators and detectors flip-chip bonded to CMOS circuitry. This chip is one of the most complex designs ever reported in this technology, and it operates at a simulated backplane clock rate of 125 MHz. The low-loss optical system employs f/4 diffractive minilenses and microlenses to interconnect clusters of smart pixels, and it is shown to allow 2060 connections per chip if 1-cm2 -sized smart pixel chips are …

A Hybrid-Seed Smart Pixel Array For A Four-Stage Intelligent Optical Backplane Demonstrator, David R. Rolston, David V. Plant, Ted H. Szymanski, Harvard Scott Hinton, W. S. Hsiao, Michael H. Ayliffe, David Kabal, Michael B. Venditti, P. Desai, Ashok V. Krishnamoorthy, Keith W. Goossen, J. A. Walker, B. Tseng, S. P. Hui, J. C. Cunningham, W. Y. Jan

Electrical and Computer Engineering Faculty Publications

This paper describes the VLSI design, layout, and testing of a Hybrid-SEED smart pixel array for a four-stage intelligent optical backplane. The Hybrid-SEED technology uses CMOS silicon circuitry with GaAs-AlGaAs multiple-quantum-well modulators and detectors. The chip has been designed based on the HyperPlane architecture and is composed of four smart pixels which act as a logical 4-bit parallel optical channel. It has the ability to recognize a 4-bit address header, inject electrical data onto the backplane, retransmit optical data, and extract optical data from the backplane. In addition, the smart pixel array can accommodate for optical inversions and bit permutations …

Design, Modeling, And Characterization Of Fet-Seed Smart Pixel Transceiver Arrays For Optical Backplanes, David V. Plant, Alain Z. Shang, Marcos R. Otazo, David R. Rolston, Brian Robertson, Harvard Scott Hinton

Electrical and Computer Engineering Faculty Publications

The design, modeling, and characterization of FET-SEED smart pixel transceiver arrays fabricated for application in optical backplanes are presented. Results of digital and analog measurements on 4×4 transmitter arrays and 4×4 receiver arrays, packaged at the printed circuit-board level, will be presented. In addition, these results will be compared to device and circuit models developed for these optoelectronics. Finally, the description of the successful application of these optoelectronics to interconnect two printed circuit boards will be described.

The Study Of The Resistance And Stability Of Vegetation Ecosystem Plant Groupings In Flood Control Channels: Vol. 1, William Rahmeyer, David Werth

Reports

Preface: The following report was prepared by the utah Water Research Laboratory of Utah State University in Logan, Utah. Volume 1 of the UWRL report USU--400A contains the data summary and conclusions of flow tests conducted with different plant types and ecosystem groupings of shrubs and woody vegetation in the hydraulics flumes of Utah State University. The methodology and equations that were developed to predict flow resistance for fultiple plant types include the effects of plant fexibility, varying plant density, plant characteristics, and multiple plant stems. The study included over 214 flow tests, testing of 20 different plant types, 5 …

Utah Water Research Laboratory Publications Listing 1993-1996, David S. Bowles, Leaunda S. Hemphill

Reports

No abstract provided.

Cache County Water Demand/Supply Model, Trevor C. Hughes, Gregory J. Norby, Laxman Thyagarajan

Reports

This report descibes a municipal water demand forecasting model for use in areas of mixed rural and urban housing types. A series of residential demand functions were derived which forecast water demand based on the ype and density of housing and season. Micro sampling techniques were used to correlate water use data and explanatory variable data for low, medium, and high density housing. The demand functions were incorporated into a geographic information system (GIS) platform cosisting of a desk-top mapping program, MapInfo, coupled with a user interface program written in Visual Basic. The GIS-based model analyzes water demand at the …

Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 1. First-Order Reaction, Jagath J. Kaluarachchi, Jahangir Morshed

Civil and Environmental Engineering Faculty Publications

Operator-splitting technique (OST) is a common mathematical approach used in the solution of the advection-dispersion-reaction equation (ADRE), especially in the presence of biological decay, where the scales of transport and biological decay are far apart. The OST introduces a time-lag between the advection-dispersion and reaction stages by splitting the ADRE causing a breakdown of the physics of the problem, thus limiting its applicability. In this work, the applicability of the operator splitting technique is studied in parts. This first manuscript addresses the critical limitations of the operator-splitting technique as related to first-order decay, and the second manuscript extends the work …

Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 2. Monod Kinetics And Coupled Transport, Jahangir Morshed, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

In the first manuscript of this two-part series, the behavior of the inherent time-lag error in the operator-splitting technique has been discussed. However, the discussion has been limited to the advection-dispersion-reaction equation with first-order kinetics. In this manuscript, the discussion is extended to address the applicability of the operator-splitting technique in solving the advection-dispersion-reaction equation with Monod kinetics. The discussion also considers the two-species coupled transport problem. The results of the analysis show that the behavior of the time-lag error causing a mass balance error is rather similar to those observed with first-order kinetics. The time-lag error directly depends on …

Design Factors For Improving The Efficiency Of Freeproduct Recovery Systems In Unconfined Aquifers, Jagath J. Kaluarachchi, R. Elliot

Civil and Environmental Engineering Faculty Publications

Free-product recovery system designs for light hydrocarbon recovery were investigated to evaluate the effects of multiple-stage pumping, delayed startup, and uncertainty of key residual oil saturation input data using a vertically integrated three-phase flow model, ARMOS. The results obtained from a single well recovery system subjected to a given well location and uniform soil properties suggested that multiple-stage water pumping can enhance the recovery and provide optimal design conditions if cost and recovery oil volume are the targets. However, if containment of the spill area with simultaneous recovery is the target, then single-stage pumping still provides the optimal design. Delayed …

Optimal Pumping Strategies To Maximize Dissolved Tce Extraction At Central Base Area, Norton Afb, California, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Norton Air Force Base (NAFB) is located in the San Bernardino Valley, part of the California Peninsular Range geomorphic province (Figure 1). The elevation at NAFB is about 1,100 feet above mean sea level (msl). The ground slopes gradually to the southwest.

Nonparametric Stochastic Generation Of Daily Precipitation And Other Weather Variables, Rajagopalan Balaji

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traditional stochastic approaches for synthetic generation of weather variables often assume a prior functional form for the stochastic process, are often not capable of reproducing the probabilistic structure present in the data, and may not be uniformly applicable across sites. In an attempt to find a general framework for stochastic generation of weather variables, this study marks a unique departure from the traditional approaches, and ushers in the use of data-driven nonparametric techniques and demonstrates their utility.

Precipitation is one of the key variables that drive hydrologic systems and hence warrants more focus. In this regard, two major aspects of …

Advanced Rover Chassis, Eric Alan Poulson, Collin Lewis, Todd Graves

Undergraduate Honors Capstone Projects

Background:

The six wheeled rover vehicle detailed in this design is intended as an upgrade test bed for the sensor array and autonomous navigation algorithms in use by Utah State University's Center for Self-Organizing and Intelligent Systems (CSOIS). The CSOIS's sensor suite can successfully detect and avoid unnavigable obstacles up to five vehicle lengths in front of the vehicle. The center presently uses a modified RC type chassis and only supports two wheel drive. This chassis was adequate to bring the CSOIS's algorithms to a proof-of-principles state, but in order to place the system in any practical application, a full …

Techniques To Improve Electron Density Measurements In The D Region Of The Ionosphere, Earl F. Pound

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The electron density of the ionosphere can be measured using rocket-borne probes that measure changes of the impedance of an antenna as it traverses the plasma. The resistive component of the antenna impedance is difficult to measure accurately in the D region of the ionosphere (50-90 km) because it has such a small value and is in series with a much larger capacitive reactance. The resistance term is squared during data analysis and this further adds to the inaccuracy. Previous data analysis has usually ignored the resistive term and led to errors of as much as 35% for the altitude …

Evaluation Of Synthetic Unit Hydrograph Techniques For Utah Probable Maximum Flood Determinations, Ashraf Mohammed Shammet

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every dam must be capable of safely passing a predetermined flood magnitude. For high-hazard dams, it is a common practice to require that this flood be the Probable Maximum Flood (PMF). The determination of the PMF starts with the determination of the Probable Maximum Precipitation (PMP). We used the generalized estimates of the PMP as outlined in Hydrometeorological Report (HMR) 49. In this study we used the storm event model approach to convert the PMP into PMF. Different synthetic unit hydrograph (SUH) techniques were then used in the conversion process. The Soil Conservation Service (SCS) curve number method was used …

Lake Evaporation: A Model Study, Jumah Amayreh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reliable evaporation data are an essential requirement in any water and/or energy budget studies. This includes operation and management of both urban and agricultural water resources. Evaporation from large, open water surfaces such as lakes and reservoirs may influence many agricultural and irrigation decisions. In this study evaporation from Bear Lake in the states of Idaho and Utah was measured using advanced research instruments (Bowen Ratio and Eddy Correlation). Actual over-lake evaporation and weather data measurements were used to understand the mechanism of evaporation in the lake, determine lake-related parameters (such as roughness lengths, heat storage, net radiation, etc.), and …

Spatial Variability And Error Limits Of Reference Evapotranspiration Estimates, Thomas W. Ley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The overall objective of this research was to develop a methodology for assessing the spatial variability and error limits of reference evapotranspiration (ET_r) estimates from a weather station network. Likely errors introduced into ET_r estimates due to sensor measurement variability and nonstandard site conditions were investigated. Temporal and spatial correlation structures of the weather variables used to compute ET_r and of ET_r data collected over a three-year period by an operational agricultural weather station network were studied.

Results indicated that ET_r errors are minimal compared to inherent model error when sensors (of the type …

An Adaptive "Natural Law" Fuzzy Controller, Sandeep D. Sequeira

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuzzy control has met with a tremendous interest in applications over the past few years. Despite its application potential, a broader industrial exploitation of fuzzy control has been hindered by the lack of standard design methods for fuzzy control systems. Fuzzy controllers have had to be designed on a case-by-case basis employing heuristics and reflecting the designer's limited insight into the control object's behavior. A number of fuzzy theorists have investigated the fuzzy system theoretic problems and results reported in the literature have been encouraging.

This thesis research has explored the notion that fuzzy control, despite being a rule-based control …

Considering Ecological Constraints While Optimizing Sustained Groundwater Yield, Pahvant Valley, Utah, Getachew Belaineh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Concern for groundwater quality and availability is increasing in Pahvant Valley. Ground-water levels are declining due to intense groundwater extraction for irrigation; water having high total dissolved solids concentration is flowing from the southwest toward the pumping sites; and discharge from natural springs in a wildlife refuge is declining. Transient simulation of aquifer response to 20 years of the 1985 pumping rates (beginning with 1985 groundwater level) predicted that spring discharge would decrease by as much as 87% from 1985 rates. Presented are preliminary pumping strategies that maximize sustainable, steady-state groundwater extraction without unacceptably reducing discharge from the springs. A …

Preliminary Pumping Strategy Analyses For Southeastern Cache Valley, Utah And River Baseflow Impacts, Shyamal B. Chowdhury, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

US/REMAX, a linear optimization model for groundwater management, is used to compute preliminary optimal sustained groundwater pumping increases for southeastern Cache Valley. US/REMAX employs the response matrix method of representing system response to stimuli as constraint equations within an optimization problem. The management objective is to maximize groundwater extraction at four specified locations subject to constrai~ts on aquifer potentiometric head, aquifer/river interflow, and the water level in the uppermost aquifer layer. Four scenarios (constraint sets) are presented. The results are most sensitive to the aquifer/river interflow constraints. Interflow is deemed important because baseflows are crucial to satisfying fish, aquatic life, …

Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Lynn M. Dudley, Ronald J. Hanks

Civil and Environmental Engineering Faculty Publications

Irrigation strategies which maximize crop yield while preventing salt from leaching to the groundwater or undesirable salt increases in the root zone are computed by using a one-dimensional simulation/optimization management model. The included constraint equations maintain a water volume balance and salt transport in the unsaturated zone. Implicit finite difference forms of the unsaturated water flow equation (Richards' equation), the diffusion-convection solute transport equation, functions describing the hydraulic properties of the medium, a root extraction function, and other constraints are used. The model uses a large discretization in time. A cyclic prediction and correction type of approach is adopted to …

Maximizing Tce Removal From A Contaminated Aquifer, Richard C. Peralta, Alaa H. Aly

Civil and Environmental Engineering Faculty Publications

A methodology for developing pumping strategies to maximize contaminant extraction is presented. The methodology consists of approximating the mass removal integral using a quadrature rule. Contaminant mass extraction is expressed as a function of the extraction rates. The relation of contaminant extraction to pumping rates is used as one of several constraints within a simulation/optimization model. The implementation and application of the methodology are described. The result is a set of pumping rates which are optimal in the sense that they maximize the mass of contaminant removed by the extraction system for a posed management scenario.