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

Physical Sciences and Mathematics Commons

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

Articles 1 - 30 of 42

Full-Text Articles in Physical Sciences and Mathematics

A Theoretical Model For Biased Superlattice Devices, Michael Ferner Dec 1992

A Theoretical Model For Biased Superlattice Devices, Michael Ferner

Theses

A model describing the subband structures and tunneling characteristics of superlattices is presented. The model solves the envelope function equations by the transfer matrix technique. The results are codified in a Fortran program, and the model is applied to several structures.

Superlattice have been studied extensively, however many new structures await investigation.

This model is presented as a preliminary design tool. The program allows a designer to do preliminary calculations. This type of investigation guides a designer toward a goal by making possible a large number of calculations on many different structures.


Bacterial Biosorption Of Heavy Metals From Liquid Wastestreams, Emilia Rus Oct 1992

Bacterial Biosorption Of Heavy Metals From Liquid Wastestreams, Emilia Rus

Theses

In this study, immobilized activated sludge from a municipal wastewater aerobic treatment plant has been evaluated as a potential biosorbent for the removal of heavy metals from liquid waste streams. The method of immobilization consists of entrapment of the microorganisms in calcium alginate beads.

The affinity of immobilized activated sludge to cadmium, lead, chromium and copper has been evaluated under well defined laboratory conditions.

Initially, the time course of metallic ions uptake and the effect of pH and temperature on biosorption were studied for each metal. Then the biosorption pattern and the effect of biosorbent concentration on binding capacity were …


Performance Analysis Of Queueing Systems With Synchronous Server, Wonmu Hur Oct 1992

Performance Analysis Of Queueing Systems With Synchronous Server, Wonmu Hur

Theses

The performance measures are derived for a queueing system which is characterized by its synchronous server operations. This property is the one which normal queueing systems lack. A system of this nature contains a single common server to which multiple number of buffers are connected in parallel, where the server operates only when all system buffers are occupied.

In this thesis, the analysis is carried out focusing on the simplest system involving only two buffers. Throughout the analysis, a symmetricity of the system is assumed (i.e., system is symmetrical in terms of arriving customer statistics.). Also assumed are the Poisson …


Quantitative Measurement Of Pyrolysis And Combustion Species Concentration By Molecular-Beam-Sampling-Mass-Spectrometry, Xian Zhong Oct 1992

Quantitative Measurement Of Pyrolysis And Combustion Species Concentration By Molecular-Beam-Sampling-Mass-Spectrometry, Xian Zhong

Theses

A molecular-beam-sampling apparatus utilizing both a time-of-flight mass spectrometer with vacuum ultraviolet (VUV) photoionization and a quadrupole mass spectrometer with electron impact ionization is described. These systems are used to analyze reactants and products, as well as reactive intermediates, from flow tube experiments at reduced pressures and elevated temperatures. It is shown that the quadrupole signal sensitivity can be predicted using literature cross sections which are based upon the atom hybridization within the various molecules. Measurements of the VUV photoionization sensitivity for stable species led to development of a group additivity approach to predict cross sections. This approach was extended …


Determination Of Pentachlorophenol In Wood And Leachate From Discarded Treated Wooden Poles, Yan Zha Oct 1992

Determination Of Pentachlorophenol In Wood And Leachate From Discarded Treated Wooden Poles, Yan Zha

Theses

Pentachlorophenol(PCP) has long been used as a preservative in the wood industry. The disposal of the used treated wood poles in landfill is of an environmental concern.

The study presented in this paper was designed to determine the leaching of pentachlorophenol from treated aged wood. An analytical method for HPLC determination of PCP was developed and validated to perform the analysis of pentachlorophenol in samples of the oringinal wood and leaching solutions.

Further studies involved the description of the PCP distribution in wood poles, the estimation of the leaching rate of PCP and the factors which influence the leaching rate …


Thermal Decomposition Of Dichloromethane In Absence And Presence Of Added Oxygen And/Or Methane, Hong-Ming Chiang Oct 1992

Thermal Decomposition Of Dichloromethane In Absence And Presence Of Added Oxygen And/Or Methane, Hong-Ming Chiang

Theses

Thermal decomposition experiments on dichloromethane in absence and presence of added O2 and/or 4 and in argon bath gas were conducted in a tubular flow reactor. The thermal reactions were studied at 1 atmosphere pressure with residence times of 0.3 - 2.0 seconds in the temperature range from 680 to 840 °C.

The degradation of dichloromethane and the decomposition product distributions were studied in both oxidative and pyrolytic reaction environments. The slowest decay of dichloromethane occurred when CH4 was present and 02 was absent. The concentration of all products, (except HCl, CO, and CO2 in the oxidation), …


Synthesis Of Bisphenol A Bis-2-Hydroxypropylmethacrylate (Bisgma) And Diethylchlorophosphate And 2-Hydroxyethylmethacrylate (Decp-Hema) And Preparation Of Dental Adhesives, Da Xie Oct 1992

Synthesis Of Bisphenol A Bis-2-Hydroxypropylmethacrylate (Bisgma) And Diethylchlorophosphate And 2-Hydroxyethylmethacrylate (Decp-Hema) And Preparation Of Dental Adhesives, Da Xie

Theses

BisGMA and DECP-HEMA were separately synthesized from Bisphenol A and glycidyl methacrylate and from diethylchlorophosphate and 2-hydroxyethyl-methacrylate. The structure of the monomer, BisGMA, was further analyzed by means of chromatography, VPO, IR, FTIR and GC-MASS.

Based on the main monomers, BisGMA, DECP-HEMA and an organosilane compound, a dental adhesive has been formulated. Although the tervile strength of the adhesive has been found to be not as good as the adhesive formulated by a previous worker (student), its applicability to teeth is more suitable for clinic practice.


A Theoretical Study Of The Subband Structures And Tunneling In Polytype Heterostructures, Hong Chen Oct 1992

A Theoretical Study Of The Subband Structures And Tunneling In Polytype Heterostructures, Hong Chen

Theses

A theoretical study of the electronic and optical properties in polytype heterostructures is presented in this thesis.

In the first part of the thesis (Chap. 2 and Chap. 3), an explicit expression for calculating the subband structure and tunneling is formulated by the incorporation of the envelope function approximations and the transfer matrix technique. It is based on the k*p theory as done to date, but contains two significant improvements: a more realistic treatment of the spatial and energetic dependance of effective masses and band edges; the availability of the calculations, in favor of direct numerical evaluation, to various quantum …


Domain Analysis Within The Gensif Framework, Heiko Thimm Oct 1992

Domain Analysis Within The Gensif Framework, Heiko Thimm

Theses

The GenSIF framework which is targeted towards very large, distributed, and complex software systems recently has been proposed to accomplish a form of systems engineering and systems development in which the issue of systems integration is considered from the beginning on.

One of the components of GenSIF is domain analysis. Domain analysis leads to the design of a domain model. The specific needs GenSIF has in that area were investigated with an emphasis on domain modeling. Main points addressed in that investigation were the issue regarding the relevant information for the domain modeling process and the required type of domain …


Design And Implementation Of Two Text Recognition Algorithms, Madhumathi Yendamuri Oct 1992

Design And Implementation Of Two Text Recognition Algorithms, Madhumathi Yendamuri

Theses

This report presents two algorithms for text recognition. One is a neural-based orthogonal vector with pseudo-inverse approach for pattern recognition. A method to generate N orthogonal vectors for an N-neuron network is also presented. This approach converges the input to the corresponding orthogonal vector representing the prototype vector. This approach can restore an image to the original image and thus has error recovery capacility. Also, the concept of sub-networking is applied to this approach to enhance the memory capacity of the neural network. This concept drastically increases the memory capacity of the network and also causes a reduction of the …


Character Recognition Using String Matching, Xiaozhi Ye Oct 1992

Character Recognition Using String Matching, Xiaozhi Ye

Theses

To handle noisy and distorted pattern is the use of similarity or distance measures. A similarity or distance measure can be defined between a representation of an unknown pattern and a representation of a prototype pattern. Recognition of the unknown pattern can be carried out on the basis of the maximum-similarity or minimum distance criterion (Bunke 1990) This approach is proposed to recognize the noisy or distorted character image. In this work, a directly string representation of the pattern ( prototype as well as unknown input) using the histogram method, a decision procedure for classification is the well known Levenshtein …


Instrumentation For The Characterization Of 10 Micron Focal Plane Array Detectors, Zhen Zong Oct 1992

Instrumentation For The Characterization Of 10 Micron Focal Plane Array Detectors, Zhen Zong

Theses

In the atmospheric window thermal imaging technology, the 8-12 micron spectral range is of particular interest, since the 300 K black body radiation peaks at around 10 micron with a flux as large as 1019photons/cm2sec. Due to its extreme temperature sensitivity for the 300 K background imaging, this long wave length infrared atmospheric window is vital for a variety of applications. A monolithic GaAs multiple quantum well (MQW) IR image sensor in this spectrum region is being developed in the research group of Profs. K. Chin and J. C. Hensel.

The work performed here is to set up a computer-controlled …


Porting Cosmos Expert System From Unix To Dos, Ching-Jeng Chiu Oct 1992

Porting Cosmos Expert System From Unix To Dos, Ching-Jeng Chiu

Theses

COSMOS is an object-oriented Knowledge Based System building Tools (KBSTs) to solve problem in engineering industry. COSMOS stands for C++ Object-oriented System Made for expert System development.

In order to provide more people those who don't have a Sun workstation to use this expert system, our task is porting COSMOS form UNIX to DOS.

Because the differents of workstation environment, the user interface and structure of original COSMOS no longer can be used, therefore we made some necessary change before we porting it to IBM Personal Computer.

In stead of X Window system®, we implemented ObjectWindows® runs on Microsoft WindowsTM. …


Thermal Oxidative Decomposition Of Chlorobenzene In A Tubular Flow Reactor, Jian Liu May 1992

Thermal Oxidative Decomposition Of Chlorobenzene In A Tubular Flow Reactor, Jian Liu

Theses

The thermal reaction experiments of chlorobenzene decomposition were carried out in a tubular flow reactor in hydrogen and oxygen mixtures ranged from 1% to 5% at one atmosphere total pressure. Experiment temperatures were varied over a range of 590--640°C. Residence times ranged from 0.3 to 2.0 seconds.

It was found that the decomposition of chlorobenzene increased with both temperature and residence time. The oxidation of chlorobenzene occurred more rapidly when oxygen concentration was increased. 95% decomposition of chlorobenzene occurred at 620°C, O2/H2 = 5%, and two seconds residence time.

The major products were benzene and HCl, and …


The Removal Hcl From Hot Gases With Calcium Compounds, Qian Lao May 1992

The Removal Hcl From Hot Gases With Calcium Compounds, Qian Lao

Theses

The use of CaCO3, Ca(OH)2, and CaO as adsorbents for removal of HCl from hot gas streams is investigated through a series of experiments. The experiments are conducted to evaluate the influence of key parameters such as temperature, (500 K to 1000 K), particle size, (0.037 mm to 3.36 mm), pressure drop of the packed bed, (0.1 cm H2O to 25.5 cm H2O), and concentration of CCl in the feed gas, (1,550 ppm to 20,000 ppm), on HCl adsorption. The results of these experiments show that all three of the calcium compound …


Microwave Treatment Of Hazardous Wastes : Feasibility Studies - Operating Costs, Yongping Lu May 1992

Microwave Treatment Of Hazardous Wastes : Feasibility Studies - Operating Costs, Yongping Lu

Theses

Pilot plant studies have been carried out on a process for the remediation of soils contaminated with volatile organics (VOCs) and semi-volatile organics (SVOCs) by microwave-assisted steam distillation that had been developed in benchscale studies. The major concern had been that the process is based upon the use of electrical energy, and thus could not be competitive with fossil fuel based technologies like incineration. That concern was addressed in the pilot plant studies.

A pilot plant rated at 6 kW power and a cavity of approximately 60 cubic feet was used. In studies carried out on a water load it …


Measurement Of Vocs Pollution From Recycling Petroleum Contaminated Soils In Hot Mix Asphalt Concrete, Yaoqing Chen May 1992

Measurement Of Vocs Pollution From Recycling Petroleum Contaminated Soils In Hot Mix Asphalt Concrete, Yaoqing Chen

Theses

The petroleum contaminated soils (PCSs) due to leaking underground storagetanks are required to be removed and isolated in a designated area for proper treatment. Recently, a technique of recycle has been developed to incorporate PCSs into hot mixing asphalt (HMA) as a partial substitute for stone aggregate; the mixture then was used for road paving.

This study focuses on the estimation of the emission of volatile organic compounds from the process of mixing asphalt with PCSs and the contamination of ground water by paving the asphalt mixture made with PCSs. Eleven volatile organic compounds and total non-methane organic compounds emitted …


Decomposition Of Geometric-Shaped Structuring Elements And Optimization On Euclidean Distance Transformation Using Morphology, Hong Wu May 1992

Decomposition Of Geometric-Shaped Structuring Elements And Optimization On Euclidean Distance Transformation Using Morphology, Hong Wu

Theses

Mathematical morphology which is based on geometric shape, provides an approach to the processing and analysis of digital images. Several widely-used geometric-shaped structuring elements can be used to explore the shape characteristics of an object. In first chapter, we present a unified technique to simplify the decomposition of various types of big geometric-shaped structuring elements into dilations of smaller structuring components by the use of a mathematical transformation. Hence, the desired morphological erosion and dilation are equivalent to a simple inverse transformation over the result of operations on the transformed decomposable structuring elements. We also present a strategy to decompose …


Influence Of Fly Ash And Chromium Characteristics On Compressive Strength Of Mortar And Concrete, Lin Wang May 1992

Influence Of Fly Ash And Chromium Characteristics On Compressive Strength Of Mortar And Concrete, Lin Wang

Theses

The behavior of cement mortar incorporating fly ash varies with chemical and physical characteristics of fly ash. Of many parameters affecting the compressive strength of fly ash mortar, five were investigated in this study. They are the particle size, the particle size distribution, fineness of fly ash, the CaO content and the Fe2O3 content.

Fly ashes from two different sources were used in this study. One comes from the Public Service Electric and Gas (PSE&G)'s electrical generation station in Hudson County and the other is from the PSE&G plant in Mercer County. Each was separated into seven …


The Use Of Henry's Law Constants In The Determination Of Factors That Influence Voc Concentration In Aqueous And Gaseous Phases In Wastewater Treatment Plant, Hui-Zhi Yu May 1992

The Use Of Henry's Law Constants In The Determination Of Factors That Influence Voc Concentration In Aqueous And Gaseous Phases In Wastewater Treatment Plant, Hui-Zhi Yu

Theses

This study focuses on the determination and comparison of Henry's law constant of eight selected volatile organic compounds in the wastewater of Linden Roselle Sewerage Authority (LRSA) wastewater treatment plant. The factors that influence the vapor-aqueous equilibrium were studied by calculating the Henry's law constants of the different species determined in the gas phase before and after the spiking of different aqueous media. Both centrifuged and uncentrifuged wastewater samples were studied, and compared to distilled water.

For wastewater sample with no suspended particles, the amount of organics in wastewater appears to influence the Henry's law constant for compounds with low …


I: Reaction Of Ch3c1 With H2 And Ch4 Under Oxidation And Pyrolysis Conditions Ii: Kinetic Analysis Of C2h6, C2h4, And C2h2 Reactions With Oh, O, H, And Cl, Qing-Rui Yu May 1992

I: Reaction Of Ch3c1 With H2 And Ch4 Under Oxidation And Pyrolysis Conditions Ii: Kinetic Analysis Of C2h6, C2h4, And C2h2 Reactions With Oh, O, H, And Cl, Qing-Rui Yu

Theses

Experimental and detailed modeling are presented for the high temperature combustion systems involving CH3Cl/CH4/O2 and C33Cl/H2/O2 reactions. More important C2 species reaction rate constant are created. A mechanism incorporating 263 step elementary reactions and 76 stable compounds and active radicals is developed based on (1) fundamental thermochemical and Kinetic principles (2) Quantum Rice-Ramsperger-Kassel (QRRK) theory analysis (3) accurate thermodynamic Properties and thermochemical analysis (4) reliable experimental data to validate our model.

The study of Part II evaluates and analyzes theoretically the rate constants of C2H6, C …


Design Of Stable Di And Tetraradical Nitroxides As Magnetic Resonance Imaging Agents, Radha V. Iyer May 1992

Design Of Stable Di And Tetraradical Nitroxides As Magnetic Resonance Imaging Agents, Radha V. Iyer

Theses

Several nitroxides have been prepared in the Biotechnology Laboratory at NJIT to study their image enhancement capability. These nitroxides contain different moieties within one molecule and their paramagnetism is found to be initially increasing proportionally to the number of their radical centers. It is found that the addition of nitroxides at very close distances causes interference and a reduction of intensity due to the interaction of the two paramagnetic centers with each other. Thus MRI contrast agents are not improved by simple addition of nitroxide centers to a given molecule and drug designers must pay special attention to intramolecular spacing. …


Graphical Image Persistence And Code Generation For Object Oriented Databases, Subrata Chatterjee May 1992

Graphical Image Persistence And Code Generation For Object Oriented Databases, Subrata Chatterjee

Theses

Attached is the detailed description of the design and implementation of graphical image persistence and code generation for object oriented databases. Graphical image persistent is incorporated into a graphics editor called OODINI. OODINI creates and manipulates graphical schemas for object-oriented databases. This graphical image on secondary storage is then translated into an abstract, generic code for dual model databases. This abstract code, DAL can then be converted into different dual model database languages. We provide an example by generating code for the VODAK Data Modeling language. It is also possible to generate a different abstract language code, OODAL from a …


Interpreting And Integrating Landsat Remote Sensing Image And Geographic Information System By Fuzzy Unsupervised Clustering Algorithm, Gwotsong Philip Chen May 1992

Interpreting And Integrating Landsat Remote Sensing Image And Geographic Information System By Fuzzy Unsupervised Clustering Algorithm, Gwotsong Philip Chen

Theses

Due to the resolution of Landsat images and the multiplicity of the terrain, it is improper to assign each pixel in an image to one of a number of land cover types by using the conventional remote sensing classification method. This is also known as the hard partition method. The concept of the fuzzy set provides the means to resolve this problem. This paper presents a two-pass-mode fuzzy unsupervised clustering algorithm.

In the first passing, the cluster mean vectors which represent the geographic attributes or the land cover types are derived. In the second passing, the concept of fuzzy set …


Transformations And Analysis Of Parallel Real Time Programs, Chandima J. Gunasekara May 1992

Transformations And Analysis Of Parallel Real Time Programs, Chandima J. Gunasekara

Theses

The problem of schedulability analysis of a set of real time programs form a NP complete problem. The exponential complexity of analysis is a direct result of the complexity in the real time programs, as a combinatorial explosion takes place when trying to determine access patterns of shared resources. Thus, to transform the original programs to a less complex form, while preserving its timing characteristics, is the only viable solution. By using such transformations to reduce the complexity of real time programs, it is possible to schedulability analyze programs at compile time efficiently, without adding an unnecessary overhead to the …


Irreversible Immobilization Of Heavy Metal, Hyoung-Seog Ko May 1992

Irreversible Immobilization Of Heavy Metal, Hyoung-Seog Ko

Theses

Heavy metals are contaminants of both solid and liquid wastes. For example, the ash produced from the incineration of domestic or industrial wastes often contains substantial concentration of lead, mercury, cadmium and other heavy metals that make it a hazardous waste. These heavy metals in wastes are hazardous because they are mobile. Immobilization of the metals is an effective method of rendering the metals harmless, provided that immobilization is irreversible. This study focused on the heavy metal immobilization potential associated with the activities of anaerobic bacteria known as the dissimilatory sulfate reducers (Postgate, 1984). The sulfate-reducing bacteria produce sulfide and …


An Implementation And Evaluation Of Distributed Information System Based On The Osca Architecture Guidelines, Babita Masand May 1992

An Implementation And Evaluation Of Distributed Information System Based On The Osca Architecture Guidelines, Babita Masand

Theses

The concepts in this thesis discuss and evaluate the need for systems integration. As a conceptual architecture, the OSCATM architecture is investigated. A prototype of the CS Department distributed information system is built following the guidelines and standards of this conceptual architecture. This prototype is implemented in 'C'. RPC (remote procedure call) is used for the communication channel to implement the distributed environment. Conclusions and results that were achieved by implementing this prototype are presented. The main outcome of this thesis is the introduction of the infrastructure to the GenSIF framework.


New Algorithms For Mid-Crack Codes In Image Processing, Wai-Tak Wong May 1992

New Algorithms For Mid-Crack Codes In Image Processing, Wai-Tak Wong

Theses

The chain code is a widely-used description for a contour image. Recently, a mid-crack code algorithm has been proposed as another more precise method for image representation. New algorithms using this new mid-crack code for image representation, restoration, and skeletonization are developed. The efficiency and accuracy can be increased obviously.

Firstly, the conversion of a binary image with multiple regions into the mid-crack codes is presented. A fast on-line implementation can be achieved using tables look-up. The input binary image may contain several object regions and their mid-crack codes can be extracted at the same time in a single-pass row-by-row …


Microwave Treatment Of Hazardous Wastes : Feasibility Studies-Mass Balances, Liu Liu Apr 1992

Microwave Treatment Of Hazardous Wastes : Feasibility Studies-Mass Balances, Liu Liu

Theses

This laboratory has been developing processes for the remediation of soils contaminated with hazardous wastes using microwave treatment. The initial stage was to define situations in which microwave treatment could potentially have unique advantages, and to define the relevant physical chemical mechanisms. That having been accomplished, at the present stage, feasibility studies are being carried to determine whether or not on-site field testing is justified. To that end, mass balances on the processes are needed. In this study mass balance studies were carried out on the microwave assisted steam distillation of volatile organic chemicals (VOCs) and semi-volatile organics (SVOCs), respectively, …


Characterization Of Low Pressure Chemical Vapor Deposited Silicon Dioxide Thin Films, Xue Du Jan 1992

Characterization Of Low Pressure Chemical Vapor Deposited Silicon Dioxide Thin Films, Xue Du

Theses

LPCVD deposited amorphous silicon dioxide SiO2 thin films from a new chemical vapor source, diethylsilane (DES), were characterized. This work is focused on evaluation of SiO2 films prepared by varies deposition temperatures and flow rates series.

SiO2 thin films were evaluated for density, porosity, and refractive index. Techniques for evaluation of the above mentioned parameters for this work included the use of infrared absorption spectroscopy, preferential etch procedures, optical measurement of refractive index and thickness, and thermal annealing of CVD films. The densification in vacuum ambient has been carried out at the temperature of 600 °, 750 …