Digital Commons Network^™

Automated Instrumentation System To Monitor Behavioral Experiments, Dilip S. Gokhale

Theses

An instrumentation system has been designed to monitor behavioral experiments on monkeys. This instrumentation system is capable of performing these experiments in an automated manner without any human intervention. It is capable of monitoring these experiments concurrently in six boxes. It exhibits several features that make it more versatile than previous instrumentation systems. It is also capable of storing the data generated on to a floppy disk and later transmitting it to the mainframe.

Another feature that makes it more versatile is the flexibility of the system. Presently it is configured to run experiments with variable interval schedules. However with …

Reliability Studies On Solid Tantalum Electrolytic Capacitors, Hamed Nassar

Theses

The primary objective of this thesis is to determine and analyze the failure mechanisms of solid tantalum capacitors, pinpoint the causes, and suggest the precautionary measures that prevent the occurrence of these failures. To achieve this goal, the study went in two directions, theoretical and experimental. The theoretical part-is a comprehensive review of the work -done on tantalum capacitors since 1960 up to date.

The experimental part of the study is a life test (1000 hours) of solid tantalum capacitors under humidity and high temperature. To avoid the misconception that could happen by investigating a particular manufacturer's product, units from …

Division-Of-Wave-Front Polarizing Beam Splitter And Half-Shade Device Using Dielectric Thin Film On Dielectric Substrate, R. M.A. Azzam

Electrical Engineering Faculty Publications

No abstract provided.

Fundy Tidal Power Development : Preliminary Evaluation Of Its Environmental Consequences To The Resources Of The State Of Maine, Bigelow Laboratory For Ocean Sciences

Maine Collection

Fundy Tidal Power Development : Preliminary Evaluation of Its Environmental Consequences to the Resources of the State of Maine

A Report to the Maine State Planning Office by the Bigelow Laboratory for Ocean Sciences, April, 1984.

"Technical Report No. 35 - Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, Maine - A Division of Northeastern Research Foundation, Inc."

Contents: Executive Summary / Introduction / Methods / Physical and Biological Consequences / Socio-Economic Consequences / Research Needs / Bibliography / Appendix I. Written Comments on Greenberg Model

Laser-Induced Surface Diffusion, Cheng-Hsiao Wu, Jonathan I. Gittleman

Electrical and Computer Engineering Faculty Research & Creative Works

A Brownian motion model for laser-induced surface diffusion is proposed to account for the kinetics of surface transport of the evaporated molecules from a thin discontinuous film under a focused laser beam. The model is solved exactly where the evaporation rate of the molecules is assumed to be proportional to the temperature rise above the ambient of the absorber layer. The surface diffusion constant and molecular velocity are obtained by comparing the results of calculations with transmission electron micrographs of recorded pits in Te trilayer opticial discs. These values are in good agreement with Einstein's relation.

The Development Of A Microprocessor Controlled Linearly Actuated Valve Assembly, Raymond H. Wall

Mechanical & Aerospace Engineering Theses & Dissertations

The development of a proportional fluid control valve/assembly is presented. This electro-mechanical system is needed for space applications to replace the current proportional flow controllers that use bulky hydraulic or pneumatic actuation systems. The flow is controlled by a microprocessor system that monitors the control parameters of upstream pressure and requested volumetric flow rate. The microprocessor achieves the ·proper valve stem displacement by means of a digital linear actuator. A linear displacement sensor is used to measure the valve stem position. 'Ibis displacement is monitored by the microprocessor system as a feedback signal to close the control loop. With an …

Design Of Multivariable Feedback Control Systems Via Spectral Assignment Using Reduced-Order Models And Reduced-Order Observers, Preston Ivanhoe Carraway Iii

Electrical & Computer Engineering Theses & Dissertations

The feasibility of using reduced-order models and reduced-order observers with eigenvalue/eigenvector assignment procedures is investigated. A review of spectral assignment synthesis procedures is presented. Then, a reduced-order model which retains essential system characteristics is formulated. A constant state feedback matrix which assigns desired closed loop eigenvalues and approximates specified closed loop eigenvectors is calculated for the reduced-order model. It is shown that the eigenvalue and eigenvector assignments made in the reduced order system are retained when the feedback matrix is implemented about the full order system. In addition, those modes and associated eigenvectors which are not included in the reduced-order …

A Plasma Focus Interrupting Switch, Gregory Francis Knapp

Electrical & Computer Engineering Theses & Dissertations

The feasibility of using a dense plasma focus (DPF) as a current interrupting device has been investigated. Specifically, a 34-kJ, Mather-type DPF was modified to accept a third electrode so that a discharge could be created between this electrode and the center electrode of the DPF by a 10-kJ inductive energy storage circuit. It was anticipated that the accelerating mechanisms of the DPF pinch, which are known to cause a rapid reduction in the DPF current, would interrupt the 1-kA to 10-kA secondary discharge current thus forcing the secondary current through an external load and hence result in power amplification. …

Block Transform Coding Of Presample Filtered Data, Thomas A. Shull

Electrical & Computer Engineering Theses & Dissertations

This dissertation addresses the application of non-adaptive transform coding for bit rate reduction of presampled filtered data. Transform coding is examined as an alternative to conventional pulse code modulation (PCM) for multi-source, fixed rate data acquisition systems. Typical bandlimiting presample filters introduce redundancy into the sequence of data samples. Linear transformation of successive N-length blocks of the data sequence and subsequent binary coding of the resulting components is shown to lead to reduced average bit rate for the same less distortion as PCM.

Four Butterworth filters, two corresponding to eight bit PCM systems, and two corresponding to ten bit PCM …

An Investigation Of Methods Of Surface Estimation With Application To The Interpolation Of Antenna Patterns, Paul Matthew Niall Feehan

Masters Theses

"The problem of estimating a surface from a set of discrete measurements lying along straight lines is considered. This situation arises when one attempts to determine the S-Band antenna gain pattern for the Space Shuttle, from measurements taken at several ground stations. The results of previous investigators concerned with the performance of surface approximation techniques for the present application, are extended in this study by examining the case where the data samples are corrupted by measurement noise. Results have been obtained using least-squares approximation with bicubic B-spline basis functions, and for an interpolation algorithm in conjunction with a spatial smoothing …

Radiation Damage To Gaas Solar Cells Including Isotropic Effects, Larry Victor Stock

Physics Theses & Dissertations

A model is developed for the short circuit current of a GaAs solar cell due to radiation (proton or electron) induced defects in the crystal structure. This model is verified by a comparison with proton and electron irradiation results. For electron radiation and energetic protons (energy> 10 MeV), it is found that the damage in the crystal is independent of the angle of incidence. On the other hand, for lower energy proton radiation, the damage as a function of cell thickness is highly dependent on incident angle and energy. The cell's response to low energy protons is strongly dependent on …

Lateral Coherence Of Aerosol-Scattered Laser Radiation, Donald D. Duncan, D. E. Larch

Electrical and Computer Engineering Faculty Publications and Presentations

To assess the probability of detection (by interferometric techniques) of illumination by a coherent source, we characterize the lateral coherence of the off-axis aerosol scattered radiation by applying the van Cittert-Zernike theorem. We find that, for 1.061-pm radiation at a target range of 1 km, the scattered radiation beyond 3.5 cm off axis does not display appreciable lateral coherence.

Pseudo-Brewster And Second-Brewster Angles Of An Absorbing Substrate Coated By A Transparent Thin Film, R. M.A. Azzam, T F. Thonn

Electrical Engineering Faculty Publications

The pseudo-Brewster angle of minimum reflectance for the p polarization, the corresponding angle for thes polarization, and the second-Brewster angle of minimum ratio of the p and s reflectances are all determined as functions of the thickness of a transparent film coating an absorbing substrate by numerical solution of the exact equations that govern such angles of the form Re(Z′/Z) = 0, where Z = R_p, R_s, or ρ represent the complex amplitude-reflection coefficients for the p and s polarizations and their ratio (ρ =R_p/R_s), …

Photodetachment As A Control Mechanism For Diffuse Discharge Switches, Gerhard Schaefer, P. F. Williams, Karl H. Schoenbach, John T. Moseley

P. F. (Paul Frazer) Williams Publications

Photodetachment is considered as a control mechanism for diffuse discharge switches. Experiments have been performed on photodetachment of ions in the flowing afterglow of a dc glow discharge in oxygen. Experiments with different laser wavelengths and the dependence of the optogalvanic signal on the laser energy flux indicate that 0^- is the dominant negative ion. For an energy flux of 35 mJ/cm², 50 percent of the 0^- ions can be photodetached.

Limiting Efficiencies For Multiple Energy-Gap Quantum Devices, Cheng-Hsiao Wu, Richard M. Williams

Electrical and Computer Engineering Faculty Research & Creative Works

We have used a thermodynamic model to calculate theoretical limiting efficiencies for simple and multiple gap solar cells. The limiting efficiency is 26% for a simple solar cell of hydrogenated amorphous silicon, operating at one Sun sensitivity. For a multiple gap cell made from hydrogenated amorphous silicon, together with a second cell, made from a material with lower band gap, it is 38%. The optimum band gap for the second material is 1.0 eV.

Circuit Analysis Of A Gas Flow Switch, Teri Marie Owens

Electrical & Computer Engineering Theses & Dissertations

The circuit analysis of a gas flow switch is presented. The objective of the analysis is to model the switching process during spark gap breakdown. This information is useful in understanding switch operation and identifying ways to improve switch performance.

A lumped circuit model is used to describe a gas flow switch during the switching process. Certain circuit element values are determined experimentally through static tests. Other component values, including a time-varying switch resistance and inductance, are estimated from current measurements. In particular, unknown constants in expressions for gap resistance and inductance are determined using an iterative parameter estimation technique. …

Chebyshev Method Solution Of The Time-Dependent Transport Equation To Describe The Scattering Of Gaussian Plane Wave Pulses, Jonqpyng Yuan

Theses

Millimeter-wave propagation in vegetation (forests) is studied using transport theory. A periodic sequence of gaussian plane wave pulses is assumed to enter a forest. The forest is first modeled as a slab and then treated as a half-space by letting the thickness of the slab go to infinity. The forest is assumed to consist of a random distribution of particles which scatters energy isotropically. The time dependent equation of radiative transfer in such a scattering and absorbing medium is solved by using Chebyshev polynomials as basis functions for series expansions of the diffuse or incoherent intensity. This choice of basis …

Data Acquisition And Parameter Identification In Electro-Oculography, Wolfgang Poelzleitner

Theses

Electro-Oculography (EOG) is used in clinical ophthalmology to measure the time response of the corneoretinal potential (CRP) to changes in light intensity. An automatized data acquisition and system modeling link has been developed that significantly reduces processing time presently required for EOG. The data acquisition is performed on a microprocessor based instrument, which supervises the EOG-test, measures the potential and, after completion of the test, transfers the results to a mainframe computer. Parameter identification routines provide graphical representation and mathematical models for the CRP. Both nonlinear curve fitting methods and Least Squares System Identification schemes are used.

Self‐Refraction Of Nonlinear Capillary‐Gravity Waves, Partha P. Banerjee, Adrianus Korpel, Karl E. Lonngren

Electrical and Computer Engineering Faculty Publications

Self‐refraction effects have been observed during the propagation of deep‐water capillary‐gravity waves. The observations are shown to be in qualitative agreement with the theory of self‐focusing and defocusing in a cubically nonlinear medium in the presence of diffraction.

Explicit Equations For The Second Brewster Angle Of An Interface Between A Transparent And An Absorbing Medium, R. M.A. Azzam

Electrical Engineering Faculty Publications

The second Brewster angle _ΦB2, at which the ratio R_p/R_s of intensity reflectances R_p and R_s for the parallel (p) and the perpendicular (s) polarizations of a dielectric-conductor interface reaches a minimum, is determined by Im[(u - ∊)(u - ∊)²/(u - 2∊)²] = 0, where ∊ is the complex ratio of dielectric constants of the media of refraction and incidence, ∊ = ∊/(∊ + 1), and u= sin²_ΦB2. An equivalent quartic equation in u …

Simple And Direct Determination Of Complex Refractive Index And Thickness Of Unsupported Or Embedded Thin Films By Combined Reflection And Transmission Ellipsometry At 45° Angle Of Incidence, R. M.A. Azzam

Electrical Engineering Faculty Publications

Measurements of the polarization states (represented by complex numbers X_r and X_t, respectively) of light reflected and transmitted by an unsupported or embedded thin film, for totally polarized light (with nonzero p and s components) incident at 45°, permit simple, direct, and explicit determination of the film's complex refractive index N₁ independently of film thickness or input polarization. If α = X_r/X_t, we find that α = r_s + r_s^-1, where r_s is Fresnel’s complex reflection coefficient of the ambient-film interface for the s polarization at …

Experiments Conducted On The Electron Beam Produced By A Dense Plasma Focus, Mark Steven Pronko

Electrical & Computer Engineering Theses & Dissertations

An experimental investigation was conducted using a 34-kJ Dense Plasma Focus (DPF) in which the possible enhancement of the electron beam was addressed. Electron beams ejected from the DPF have been observed to exceed 30 kA with pulse durations of a few nanoseconds. Enhancement was considered to be either an increase in the probability that the peak beam current exceeded some lower limit, or an increase in the mean energy of the beam electrons. The investigation was divided into two parts, each addressing one of the aspects of enhancement.

In the first part of the investigation, an axial magnetic field …

Maximum Minimum Reflectance Of Parallel-Polarized Light At Interfaces Between Transparent And Absorbing Media, R. M.A. Azzam

Electrical Engineering Faculty Publications

The pseudo-Brewster angle Ø_pB, of minimum reflectance R_pm for the parallel (p) polarization, of an interface between a transparent and an absorbing medium is determined by Im{(∊ - u)[1 - (1 + ∊^-1)u]²} = 0, where ∊ is the complex ratio of dielectric constants of the media and u = sin²ø_pB. It is shown that, for a given value of the normal-incidence amplitude reflectance |r|, there is an associated normal-incidence phase shift, δ = δ_mm, that leads to maximum minimum parallel reflectance, …

Application Of Fuzzy Theory To Pattern Recognition, David Usechak

Dissertations

Piecewise curve approximation is used to describe boundaries of objects in pictures and waveforms. The method consists of linear and quadratic piecewise polynomial approximations in which the error must not exceed a predetermined cost threshold. A fuzzy Bayes model is used to determine if a breakpoint exists within an interval I_n or between intervals I_n and I_n+1 and to determine whether these intervals can be merged for data compaction reasons. In order to achieve these objectives a new fast algorithm has been proposed which gives good curve/object fitting. This algorithm uses a technique for generating generalized inverse …

Gallium Nitride Film Deposition By Ionized Cluster Beam Epitaxy, Ghulum Bakiri

Theses

An experimental Ionized Cluster Beam System similar in design to the one developed at Kyoto University in Japan was. designed and constructed in the Microelectronics Laboratory at NJIT. This involved making the working drawings, having the parts machined and then assembling the system in a vacuum system together with the necessary variable power supplies, meters, controls, gas inlets, cooling water connections, etc.

Eleven deposition runs were then attempted to grow gallium nitride utilizing the system constructed. In a typical deposition run, gallium was vaporized from a boron nitride crucible at 1000° C and allowed to expand through a 0.5 mm …

Dependence Of The Conduction Properties Of Annealed Films Of (Hg0.8,Cd0.2)Te On Sputter Deposition And Annealing Parameters, Chia-Jen Wu

Theses

The dependence on annealing parameters of the electrical properties of ten micron thick, (Hg_0.8,0d0.₂)Te films triode-sputtered onto silicon substrates with (111) surface orientation, was studied. The films held positioned in a quartz tube were annealed for 48-54 hours in zone furnace. The film temperature was chosen to be between 230 and 350°C and the Hg pressure was varied between 36 to 620 mmHg. The annealed films were characterized on the basis of free carrier concentrations and carrier mobilities measured by the Hall-effect at temperatures between 94 and 300 degree Kelvin and with magnetic fields between 0.165 …

A Parameter Identification System For The Human Visual Evoked Response, Robert Kalle Michaels

Theses

The Human Visual Evoked Response (VER) provides a useful tool for analyzing an individual's visual system. However, mere inspection of the signal may not always be the best way to make a diagnosis of the patient. To aid in this diagnosis a parameter identification system has been developed which fits the response to an analog model. The development of the model was based on the results of a survey of previous work in the field. Data were acquired from a data acquisition/processing system developed at the New Jersey University of Medicine and Dentistry and the Eye Institute of New Jersey. …

Automated Instrumentation System For Studies Of Metabolic Rates In Rats, Suhas P. Pathak

Theses

The task of the instrumentation system is to measure the respiratory exchange in rats in a controlled experiment. Air is drawn at a predeter-mined rate in and out of rat chambers. The proportion of oxygen and carbon dioxide in the ensuing air indicates the respiratory rate of the rat. The entire operation is controlled by a microcomputer whose most important functions are: to direct the flow of air through the rat chambers by switching valves; and to collect data about the percentages of gases in question.

Thus with the help of a computer it is possible to monitor and control …

Investigation Of The Behavior Of Ferromagnetic Liquids In Magnetic Fields, Avinash Narcinva Velingker

Theses

Ferromagnetic liquids are superparamagnetic in character possessing paramagnetic as well as an almost loose ferromagnetic behavior. The magnetization response has been treated by classical mathematical techniques and computer methods for different excitation functions.

Also, experimental work has been carried out to study the gyromagnetic phenomenon exhibited by ferric fluids when subjected to external magnetic fields. The experimental set-up consists of a solenoid wound around a glass tube channel through which ferrofluid can be circulated at different velocities. The experimental results revealed that saturation occurs at certain level as the field intensity is increased and prior to this point, resonance takes …

The Role Of Electrical Noise In Screening Transformers Prone To Failure, Rajeev D. Shirodkar

Theses

Insulation used as a barrier between the high voltage and low voltage windings of a transformer has sites of in- homogeneities like pinholes, cracks or voids, developed during the manufacturing process. Thus, these minute air pockets are stressed much more than the solid dielectric, on the application of a voltage stress, because the dielectric constant of the solid insulation is many times that of the air dielectric. As a result, excitation or ionization takes place in the air (gases). The amount of excited or ionized molecules is proportional to the volume of the inhomogenei- ties within the insulation.

Therefore, experiments …