Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 32221 - 32250 of 34156

Full-Text Articles in Entire DC Network

Mn-Catalyzed Oxidation Of Multiple-Ringed Aromatics, G. Whelan, Ronald C. Sims Jan 1995

Mn-Catalyzed Oxidation Of Multiple-Ringed Aromatics, G. Whelan, Ronald C. Sims

Biological Engineering Faculty Publications

The role of manganese (Mn) oxides in catalyzing the abiotic oxidation of polynuclear aromatic compounds (PNAs) has been investigated by monitoring the oxidation of dihydrodiol and dione PNAs and corresponding reduction of Mn in an aqueous environment. 1,4-, 1,3-, and 2,3-naphthalenediol, 1,4-naphthoquinone, and l,4-dihydroxy-9,10-anthracenedione (Quinizarin) were oxidized in an oxic, aqueous environment, where each of these organic compounds is soluble in water, except Quinizarin. A mathematical model is presented, which describes the redox reactions, and suggests that electron transfer/organic release from the oxide surface is rate limiting with the reaction apparently proceeding through a free-radical formation. Results indicate significant oxidation …


Treatment Of Pentachlorophenol With Manganese Oxide Addition To Biotic And Abiotic Sediments, R. Petrie, J. E. Mclean, Ronald C. Sims Jan 1995

Treatment Of Pentachlorophenol With Manganese Oxide Addition To Biotic And Abiotic Sediments, R. Petrie, J. E. Mclean, Ronald C. Sims

Biological Engineering Faculty Publications

Laboratory microcosms containing subsamples of a complex environmental sediment were used to evaluate the addition of oxidized manganese as the primary electron acceptor in the presence of pentachlorophenol (PCP) as the primary electron donor. Manganese oxide (MnO2) particles were added to poisoned abiotic and non-poisoned biotic microcosms and incubated at 11°C in the presence of sediment samples that were shown capable of mineralizing PCP with indigenous microorganisms. Reduction in PCP concentration and production of reduced manganese was measured for both abiotic and biotic systems.

PCP was observed to be transformed most rapidly and to the greatest extent in …


Evaluation Of Biological Treatability Of Soil Contaminated With Manufactured Gas Plant Waste, J. S. Ginn, Ronald C. Sims, I. P. Murarka Jan 1995

Evaluation Of Biological Treatability Of Soil Contaminated With Manufactured Gas Plant Waste, J. S. Ginn, Ronald C. Sims, I. P. Murarka

Biological Engineering Faculty Publications

The biological treatability of subsurface soil contaminated with manufactured gas plant (MGP) waste was evaluated. Mineralization assays incorporating 14C-phenanthrene were used to evaluate the biotransformation potential of indigenous microorganisms at the site. Multi-phase laboratory microcosms were used to evaluate the interphase transfer potential and chemical mass distribution of phenanthrene. The Microtox™ bioassay was used to evaluate detoxification trends at the site. Mineralization results indicated that indigenous microorganisms at the site were capable of transforming phenanthrene, a component of coal-tar creosote. Results also indicated that spiked 14C-phenanthrene mineralization was influenced by nutrient addition and by the amount of contamination. …


Mn-Catalyzed Oxidation Of Naphthalenediol, G. Whelan, Ronald C. Sims Jan 1995

Mn-Catalyzed Oxidation Of Naphthalenediol, G. Whelan, Ronald C. Sims

Biological Engineering Faculty Publications

This study investigates the effects that manganese(IV) dioxide particles have on 2,3-naphthalenediol at varying pH levels (i.e., initial pH of 4.58, 5.85, and 8.75) and under different organic concentration conditions (4×10−3, 4×10−4, and 4×10−5 M), and assesses the importance of Mn oxides on abiotic catalysis of the multiple-ringed aromatic compound. Proton concentration affected the rates of reductive dissolution; as the pH values increased, the rate of reductive dissolution decreased, as predicted by theory. Also, as the concentration of naphthalenediol increased, the rate of reductive dissolution increased, although not proportionally; thus indicating that a majority of …


Optimal Pumping Strategy To Capture Tce Plume At Base Boundary, Norton Afb, California, Richard C. Peralta, A. H. Aly Jan 1995

Optimal Pumping Strategy To Capture Tce Plume At Base Boundary, Norton Afb, California, Richard C. Peralta, A. H. Aly

Civil and Environmental Engineering Faculty Publications

Ground water contaminated by trichloroethylene (TCE) at Norton AFB (NAFB) has reached off-base supply wells. Utah State University (USU) computed an optimal steady pumping strategy to eventually halt off-base migration of TCE exceeding 5 ppb. (A steady pumping strategy is a spatially distributed set of extraction and injection rates.)


Optimal Perennial Groundwater Yield Planning For Complex Nonlinear Aquifers: Methods And Examples, Shu Takahashi, Richard C. Peralta Jan 1995

Optimal Perennial Groundwater Yield Planning For Complex Nonlinear Aquifers: Methods And Examples, Shu Takahashi, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Optimal perennial groundwater yield pumping strategies were computed for a complex multilayer aquifer with: (i) confined and unconfined flow, and (ii) many flows typically described by piecewise-linear (nonsmooth) equations. The latter flows account for over 50% of the aquifer discharge from the test area, the eastern shore of the Great Salt Lake in Utah. Normally utilized response matrix (RM) and embedding (EM) simulation/optimization modelling procedures did not converge to optimal solutions for this area; they diverged or oscillated. However, the newly presented linear RM and EM approaches satisfactorily addressed the nonlinearities posed by over 2000 piecewise-linear constraints for evapotranspiration, discharge …


Stepwise Pumping Approach To Improve Free Phase Light Hydrocarbon Recovery From Unconfined Aquifers, Grant Cooper, Richard C. Peralta, Jagath J. Kaluarachchi Jan 1995

Stepwise Pumping Approach To Improve Free Phase Light Hydrocarbon Recovery From Unconfined Aquifers, Grant Cooper, Richard C. Peralta, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A stepwise, time-varying pumping approach is developed to improve free phase oil recovery of light non-aqueous phase liquids {LNAPL) from a homogeneous, unconfined aquifer. Stepwise pumping is used to contain the floating oil plume and obtain efficient free oil recovery. The pumping approach is developed using detailed simulations, multiple linear regression and graphical plots. The approach uses ARMOS©, an areal two-dimensional multiphase flow, finite-element simulation model. Systematic simulations of f~ oil area changes to pumping rates are analyzed. Pumping rates are determined that achieve LNAPL plume containment at different times (i.e. 90, 180 and 360 days) for a planning period …


Maximizing Conjunctive Use Of Surface And Ground Water Under Surface Water Quality Constraints, Muhammad Shafqat Ejaz, Richard C. Peralta Jan 1995

Maximizing Conjunctive Use Of Surface And Ground Water Under Surface Water Quality Constraints, Muhammad Shafqat Ejaz, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A simulation/optimization (s/o) model is presented to address the increasingly common conflicts between water quantity and quality objectives. The model can assist water resources analysts in selecting compromise strategies for stream/aquifer systems in which the stream gains water from the aquifer. The water quantity objective is to maximize steady conjunctive use of groundwater and surface water resources. The water quality objective is to maximize waste loading from a sewage treatment plant {STP) to the stream without violating downstream water quality beyond acceptable limits. The STP discharge is proportional to human population. The two objectives conflict because an increase in groundwater …


A Silicon Knife Design And Fabrication, Mingli Wang Jan 1995

A Silicon Knife Design And Fabrication, Mingli Wang

Theses

In this thesis, the design and fabrication of a silicon knife is described. The device design is based on the principle of oxidation sharpening.

The knife is made from a silicon wafer and can be made to be any chosen length up to 150 mm. It was made with the same basic procedures used in semiconductor chip manufacturing. This type of processing/manufacturing results in a knife with a high degree of sharpness and smoothness compared with existing knife technology.

The knife fabrication plan combines IC processing, techniques including anisotropic and isotropic etching of silicon, plasma dry etching and chemical etching …


Adaptive Resonance Associative Map, Ah-Hwee Tan Jan 1995

Adaptive Resonance Associative Map, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This article introduces a neural architecture termed Adaptive Resonance Associative Map (ARAM) that extends unsupervised Adaptive Resonance Theory (ART) systems for rapid, yet stable, heteroassociative learning. ARAM can be visualized as two overlapping ART networks sharing a single category field. Although ARAM is simpler in architecture than another class of supervised ART models known as ARTMAP, it produces classification performance equivalent to that of ARTMAP. As ARAM network structure and operations are symmetrical, associative recall can be performed in both directions. With maximal vigilance settings, ARAM encodes pattern pairs explicitly as cognitive chunks and thus guarantees perfect storage and recall …


Em Interaction Of Handset Antennas And A Human In Personal Communications, Michael A. Jensen, Yahya Rahmat-Samii Jan 1995

Em Interaction Of Handset Antennas And A Human In Personal Communications, Michael A. Jensen, Yahya Rahmat-Samii

Faculty Publications

In personal communications, the electromagnetic interaction between handset-mounted antennas and the nearby biological tissue is a key consideration. This paper presents a thorough investigation of this antenna-tissue interaction using the finite-difference time-domain (FDTD) electromagnetic simulation approach with detailed models of real-life antennas on a transceiver handset. The monopole, side-mounted planar inverted F, top-mounted bent inverted F, and back-mounted planar inverted F antennas are selected as representative examples of external and internal configurations. Detailed models of the human head and hand are implemented to investigate the effects of the tissue location and physical model on the antenna performance. Experimental results are …


Embedology And Neural Estimation For Time Series Prediction, Robert E. Garza Dec 1994

Embedology And Neural Estimation For Time Series Prediction, Robert E. Garza

Theses and Dissertations

Time series prediction has widespread application, ranging from predicting the stock market to trying to predict future locations of scud missiles. Recent work by Sauer and Casdagli has developed into the embedology theorem, which sets forth the procedures for state space manipulation and reconstruction for time series prediction. This includes embedding the time series into a higher dimensional space in order to form an attractor, a structure defined by the embedded vectors. Embedology is combined with neural technologies in an effort to create a more accurate prediction algorithm. These algorithms consist of embedology, neural networks, Euclidean space nearest neighbors, and …


Experimental Definition For Implantation Of The Afit Cortical Multielectrode Array, Adam G. Spenik Dec 1994

Experimental Definition For Implantation Of The Afit Cortical Multielectrode Array, Adam G. Spenik

Theses and Dissertations

A two-dimensional multiplexed array of 256 electrodes (16 x 16) has been fabricated using conventional CMOS fabrication techniques. The size and spacing of the electrodes (160 x 160 µm squares with center-to-center spacing of 250 µm) approximate that of the cortical columns. The device is mounted on a small biocompatible package and a protocol to implant this package on the visual cortex of a ferret and a Rhesus monkey was developed and approved. An instrumentation setup to record the data from the device is described as well as the methods used to demultiplex the data. Testing of the device in …


A Systems Engineering Approach To Environmental Risk Management: A Case Study Of Depleted Uranium At Test Area C-64, Eglin Air Force Base, Florida, Charles M. Carter, Kristina M. Fortmann, Stephen W. Hill, Robert M. Latin, Edward J. Masterson, Joseph A. Roh, Sujay R. Setlur Dec 1994

A Systems Engineering Approach To Environmental Risk Management: A Case Study Of Depleted Uranium At Test Area C-64, Eglin Air Force Base, Florida, Charles M. Carter, Kristina M. Fortmann, Stephen W. Hill, Robert M. Latin, Edward J. Masterson, Joseph A. Roh, Sujay R. Setlur

Theses and Dissertations

Environmental restoration is an area of concern in an environmentally conscious world. Much effort is required to clean up the environment and promote environmentally sound methods for managing current land use. In light of the public consciousness with the latter topic, the United States Air Force must also take an active role in addressing these environmental issues with respect to current and future USAF base land use. This thesis uses the systems engineering technique to assess human health risks and to evaluate risk management options with respect to depleted uranium contamination in the sampled region of Test Area (TA) C-64 …


Computer-Aided Breast Cancer Diagnosis, Catherine M. Kocur Dec 1994

Computer-Aided Breast Cancer Diagnosis, Catherine M. Kocur

Theses and Dissertations

This research advances computer-aided breast cancer diagnosis. More than 50 million women over the age of 40 are currently at risk from this disease in the United States. Computer-aided diagnosis is offered as a second opinion to radiologists to aid in decreasing the number of false readings of mammograms. This automated tool is designed to enhance detection and classification. New feature extraction methods are presented that provide increased classification power. Angular second moment, a second-order gray-level histogram statistic, provides baseline accuracy. Two novel extraction methods, eigenmass and wavelets, are introduced to the field. Based on the Karhunen-Loeve Transform, eigenmass features …


In Vitro Activities Of 2,2'-Bipyridyl Analogs Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez, Anita A. Dhople Dec 1994

In Vitro Activities Of 2,2'-Bipyridyl Analogs Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez, Anita A. Dhople

Biomedical Engineering and Sciences Faculty Publications

In vitro susceptibility of Mycobacterium leprae to two bipyridyl analogs was studied by using two biochemical parameters to measure the metabolic activity of the organism. VUF-8514 at 0.16 μg/ml, but not VUF-8842, completely inhibited the metabolic activity of M. leprae, and the action was bactericidal. When compared to rifampin (MIC 0.3 μg/ml), VUF-8514 was equally bactericidal against M. leprae.


An Evolutionary Approach To Allocating Tasks In Hard Real-Time Distributed Systems, Christian Lang Dec 1994

An Evolutionary Approach To Allocating Tasks In Hard Real-Time Distributed Systems, Christian Lang

Masters Theses

In real-time systems, correctness not only depends on the result of the computation but also on the time at which this result is available. The violation of timing constraints in hard real-time systems can be critical to human life or environment. Therefore, the scheduling algorithm for distributed systems has to allocate tasks to processing nodes so that no timing constraints can be violated. In addition to timing constraints, tasks have precedence and fault-tolerance constraints.

Static scheduling allocates tasks to processing nodes before the tasks are executed. Static scheduling problems are known to be NP-hard [4]. Therefore, heuristic techniques are necessary …


A 3-D Finite Difference Time Domain Investigation Of Microwave Propagation Through Inhomogeneous Biological Materials, David B. Dunn Jr. Dec 1994

A 3-D Finite Difference Time Domain Investigation Of Microwave Propagation Through Inhomogeneous Biological Materials, David B. Dunn Jr.

Theses and Dissertations

This paper extends past analysis of an optimal source distribution around a homogeneous sphere of muscle tissue by using a 3-D finite difference time domain (FDTD) scenario in which an anatomically correct human head model is irradiated. It first duplicates the analytical solution within an FDTD space using an FDTD computer code developed at Penn State University. This duplication uses a 9.45 cm radius sphere represented in an FDTD space of 2.35 mm cubic cells. FDTD simulations are then performed on four, three, and two layer laminated spheres, designed to provide simple models of a head. Finally, four simulations were …


Msda A Machinery Selection Decision Aid For Stubble Management Practices, Linda Leonard, Andrew Green Dec 1994

Msda A Machinery Selection Decision Aid For Stubble Management Practices, Linda Leonard, Andrew Green

Grain and other field crops published reports

MSDA is a user friendly program developed to help farmers predict stubble outcomes before acting on their management practice. This manual is an accompaniment to a computer program designed on Micorsoft Excel-macros. Its aim is to help farmers assess their current machinery and stubble handling ability and view options that may be adopted as best practice for their properties.

The program is designed with the complete season in mind. Information is gathered on the full complement of machinery used from harvest through to seeding, to allow farmers to see all choices available and enable them to choose the best system …


Application Of Lawn Fertilizers And Pesticides In Salt Lake Valley Recharge Areas, Ghassan R. Musharrafieh, Larry Sager, Howard M. Deer, Richard C. Peralta Dec 1994

Application Of Lawn Fertilizers And Pesticides In Salt Lake Valley Recharge Areas, Ghassan R. Musharrafieh, Larry Sager, Howard M. Deer, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Homeowners, chemical applicators, and commercial lawncare companies apply chemicals to lawns and ornamentals overlying the recharge zone of Salt Lake Valley's principal aquifer. These applied fertilizers, herbicides, insecticides, and fungicides can potentially leach far enough to contaminate ground water. This report summarizes a study conducted in 1993-1994 to determine the type, rate, and frequency of applying chemicals to lawns and ornamentals in the recharge zone. Surveyed are lawncare companies, chemical applicators, schools, churches, hospitals, parks, homeowners, and government documents and community and state regulations. Results will help assess the potential impact of these applications on future ground water quality.


Modelling For Optimal Conjunctive Water Management: Irrigated Crop Production Versus Nps Pollution Prevention, O. H. Daza, Richard C. Peralta Nov 1994

Modelling For Optimal Conjunctive Water Management: Irrigated Crop Production Versus Nps Pollution Prevention, O. H. Daza, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Conjunctive water management{CWM)involves coordinating use of ground and surface water sources. Agricultural (A) and nonagricultural {NA)users compete for available water of adequate quality. A Simulation/Optimization (S/0) conjunctive water management model was developed to aid estimating the effects of water and environmental management decisions on crop yield and water quality. Included subsystems are groundwater, surface water, reservoir, delivery system, drainage, and A and NA water users. The nonlinear model addresses flows described by nonsmooth piecewise-linear functions which have discontinuous derivatives. Embedded constraints describe all significant subsystem flows. For example 1 deep percolation and runoff from surface irrigation are explicitly described as …


A Prototype Computational Phantom To Create Digital Images For Research And Training In Diagnostic Radiology, Charles F. Babbs Nov 1994

A Prototype Computational Phantom To Create Digital Images For Research And Training In Diagnostic Radiology, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

Research in the processing, compression, transmission, and interpretation of digital radiographic images require the testing and evaluation of a wide variety of images, varying both in format and in spatial resolution. If receiver operating characteristic (ROC) analysis or a related method is used to evaluate the performance of observers using novel vs. conventional displays, large numbers of test images containing known abnormalities are required. This report describes a convenient, inexpensive, and reproducible source of test images, having any desired resolution and containing precisely defined abnormalities of unlimited subtlety. The images are generated by computing x-ray transmission through mathematically defined, three …


Expression Of A Functional Human Complement Inhibitor In A Transgenic Pig As A Model For The Prevention Of Xenogeneic Hyperacute Organ Rejection., William L. Fodor, Barry L. Williams, Louis A. Martis, Josaeph A. Madri, Scott A. Rollins, James W. Knight, William H. Velander, Stephen P. Squinto Nov 1994

Expression Of A Functional Human Complement Inhibitor In A Transgenic Pig As A Model For The Prevention Of Xenogeneic Hyperacute Organ Rejection., William L. Fodor, Barry L. Williams, Louis A. Martis, Josaeph A. Madri, Scott A. Rollins, James W. Knight, William H. Velander, Stephen P. Squinto

Papers in Biotechnology

ABSTRACT The serious shortage of human organs available for transplantation has engendered a heightened interest in the use of animal organs (xenografts) for transplantation. However, the major barrier to successful discordant xenogeneic organ transplantation is the phenomenon of hyperacute rejection. Hyperacute rejection results from the deposition of high-titer preformed antibodies that activate serum complement on the luminal surface of the vascular endothelium, leading to vessel occlusion and graft failure within minutes to hours. Although endogenous membrane-associated complement inhibitors normally protect endothelial cells from autologous complement, they are species restricted and thus confer limited resistance to activated xenogeneic complement. To address …


Computer-Aided Instruction In Dynamics: Does It Improve Learning?, Ralph E. Flori Nov 1994

Computer-Aided Instruction In Dynamics: Does It Improve Learning?, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Since 1992, the authors have been developing and testing BEST Dynamics software (Basic Engineering Software for Teaching Dynamics) with the goal of transforming how engineering dynamics is taught at the University of Missouri-Rolla, USA. This paper introduces the "BEST" Dynamics and its classroom implementation, raises questions concerning the cognitive impact of the software, attempts to classify the type of learning environment used in BEST Dynamics, and gives some new directions that are being taken based on the authors'' observations and experiences.


Ultrasonic Enhancement Of Antibiotic Action On Gram-Negative Bacteria, William G. Pitt, Michael O. Mcbride, Jared K. Lunceford, Randall J. Roper, Richard D. Sagers Nov 1994

Ultrasonic Enhancement Of Antibiotic Action On Gram-Negative Bacteria, William G. Pitt, Michael O. Mcbride, Jared K. Lunceford, Randall J. Roper, Richard D. Sagers

Faculty Publications

The effect of gentamicin upon planktonic cultures of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Staphylococcus aureus was measured with and without application of 67-kHz ultrasonic stimulation. The ultrasound was applied at levels that had no inhibitory or bactericidal activity against the bacteria. Measurements of the MIC and bactericidal activity of gentamicin against planktonic cultures of P. aeruginosa and E. coli demonstrated that simultaneous application of 67-kHz ultrasound enhanced the effectiveness of the antibiotic. A synergistic effect was observed and bacterial viability was reduced several orders of magnitude when gentamicin concentrations and ultrasonic levels which by themselves did not reduce …


Correlation Between Tidal Volume Measured By Spirometry And Impedance Pneumography, Krithika Seshadri Oct 1994

Correlation Between Tidal Volume Measured By Spirometry And Impedance Pneumography, Krithika Seshadri

Theses

In this study, an alternative method, impedance pneumography was used to measure the respiration volume. The respiration volume was measured both by using a conventional spirometer and an impedance pneumograph, and evaluated quantitatively in 17 subjects using linear and nonlinear regression algorithms.

Data were collected from 17 normal, healthy subjects during rest and paced breathing conditions. A technique was developed to measure tidal volume by impedance pneumography. The respiration volume measured by the spirometer was correlated with the volume measured by the pneumograph. Different electrode positions and postures were included in the study to determine the position and posture which …


The Use And Evaluation Of Cleaner Wicks To Accelerate In Situ Bioremediation Of Organically Contaminated Groundwater And Soil, Brian Michael Sielski Oct 1994

The Use And Evaluation Of Cleaner Wicks To Accelerate In Situ Bioremediation Of Organically Contaminated Groundwater And Soil, Brian Michael Sielski

Theses

The adaptation of Cleaner Wicks to accelerate in situ bioremediation of organically contaminated ground water and soil can be accomplished by making minor modifications to the Cleaner Wick design.

Once these changes in the Cleaner Wick design have been made the two primary ingredients necessary for aerobic microorganisms, nutrients and oxygen, can be delivered via the Cleaner Wick to the subsurface environment both above and below the water table to stimulate microbial growth and activity. Therefore, the microbial population will be able to biodegrade the target contaminants, rendering them harmless products such as carbon dioxide and water.

An adequate understanding …


Computerized Scoring Of Sleep Stage Data, Subbarao Narayana Oct 1994

Computerized Scoring Of Sleep Stage Data, Subbarao Narayana

Theses

Sleep is a non-uniform biological state which has been subdivided into different stages. The basic criteria behind staging are the amplitude and frequency variations of sleep data. The sleep analysis is carried out by considering the characteristic variation of all three EEG, EOG and EMG signals. The polygraphic recording of nocturnal sleep is a method of research widely used in neurophysiology laboratories, both for the clinical study of sleep and for the evaluation of the therapeutic effectiveness of drugs acting on sleep. The analysis of this method is carried out by an expert individual whose depth of knowledge regarding the …


Autonomic Nervous System Evaluation Using Time-Frequency Analysis, Sanjay Fernando Oct 1994

Autonomic Nervous System Evaluation Using Time-Frequency Analysis, Sanjay Fernando

Theses

Spectral analysis of heartrate variability (HRV) provided an estimate of the sympathetic and parasympatheticinfluences on heart rate without drugs or other invasive procedures.However, there are many situations where heart rate changed rapidlyover time and the control of those changes was of considerable interest.Time-frequency analysis was utilized to expand the concept of spectralanalysis of HRV to describe changes in vagal tone and sympatho-vagalbalance as a function of time. As a result the assessment of the autonomicnervous system during rapid changes in heart rate was made.

There were three advantagesto calculating vagal tone and sympatho-vagal balance by using timefrequencyanalysis. First, vagal tone …


Passive Radiosonde Transducer Design For Remote Pressure Sensing Applications, Yang Gao Oct 1994

Passive Radiosonde Transducer Design For Remote Pressure Sensing Applications, Yang Gao

Theses

Intracranial pressure can be measured to accuracies within 1 milliTorr using passive microtransponders that are micromachined using silicon as a base technology. These microtransponders can operate with either a dual-oscillator or a phase-locked loop frequency scanned control system.

The current work describes the design of a totally implantable microsensor for biomedical applications with the aim to monitor and measure the epidural intracranial pressure . The implanting microsensor is basically an RLC device in which capacitance varies with fluid pressure. The resonant frequency of RLC Series connected device varies with chemically etched diaphragm electrode spacing and thereby measures the variations with …