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

Physical Sciences and Mathematics Commons

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

Articles 1 - 21 of 21

Full-Text Articles in Physical Sciences and Mathematics

Protein And Endotoxin Interactions And Endotoxin Removal From Protein Solutions, Liping Li Aug 1999

Protein And Endotoxin Interactions And Endotoxin Removal From Protein Solutions, Liping Li

Dissertations

The investigation objectives of this study include: endotoxin disaggregation by proteins; protein concentration effect on protein-endotoxin binding and endotoxin removal; size exclusion high performance liquid chromatography (SE-HPLC) studies on endotoxin dissociation by bovin serum albumin (BSA); use of Ca+2 to re-aggregate endotoxin in hemoglobin solutions and the subsequent removal of endotoxin by ultrafiltration; quantitative determination of Ca+2 effects on endotoxin removal and protein yield in a two-stage ultrafiltration.

It is known that some proteins can disaggregate endotoxins and form complexes with lipopolysaccharides (LPS). It is also known that Ca can act as "bridges" to aggregate LPS in aqueous …


Evaluation Of Raman Spectroscopy And Ruby Piezospectroscopy As Tools For Investigating The Corrosion Of Metallic Alloys, Daniel P. Renusch Aug 1999

Evaluation Of Raman Spectroscopy And Ruby Piezospectroscopy As Tools For Investigating The Corrosion Of Metallic Alloys, Daniel P. Renusch

Dissertations

Stainless steel system components that operate in high temperature oxidizing environments obtain protection from corrosion by means of thermally grown chromia and alumina scales. Ongoing investigations of protective scales utilize a battery of experimental and theoretical techniques. A technique which has received little attention is Raman scattering. The reason for its limited use has been long data acquisition times required to obtain suitable spectra from thin surface oxides. Because advances in detection systems, namely the multichannel CCD (charge coupled devices), have recently provided dramatic improvement in the sensitivity of Raman scattering experiments, we decided to reevaluate the technique as a …


A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury Jun 1999

A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury

Dissertations

Groundwater vulnerability to contamination from surface sources was evaluated for Nottawa Creek Watershed, Calhoun County Michigan using AQUIPRO and DRASTIC vulnerability methods. A geographic information system (GIS) was used to analyze and map the data. Forty groundwater samples were collected following a statistical sampling protocol from private wells. Samples were analyzed for nitrate-N and atrazine. Atrazine was not detected (detection limit 0.1 ppb) in any of the samples. Five samples contained detectable nitrate-N (detection limit 0.05 mg/L). Due to insufficient chemical data, the relative AQUIPRO and DRASTIC vulnerability scores could not be compared with the frequency of occurrences o f …


Cadmium, Chromium And Lead In Environmental Samples : Speciation And Determination, Hsing-Hui Yu May 1999

Cadmium, Chromium And Lead In Environmental Samples : Speciation And Determination, Hsing-Hui Yu

Dissertations

Heavy metals are important contaminants in many environmental media. This work focuses on the improvement of current methods for water and sediment analysis for three metals, cadmium, chromium and lead. Batch ion exchange was used for water speciation and a microwave assisted sequential extraction scheme was developed for sediment characterization. The developed methods were applied to a group of environmental samples.

The exchangeable species of these metals in water were preconcentrated on ion exchange resins. These include the bioavailable free ions and weakly complexed ions. Metals sorbed on particles and strongly complexed ions, less bioavailable, were eliminated. The method was …


Applications Of A Microtrap For On-Line Monitoring Of Volatile Organics, Chaohua Feng May 1999

Applications Of A Microtrap For On-Line Monitoring Of Volatile Organics, Chaohua Feng

Dissertations

Microtrap is made by packing a narrow metal tubing with adsorbents. The advantage of a microtrap is that it can be heated and cooled in the order of seconds. It has been used previously as a concentration cum injection device for on-line gas chromatography and also monitoring non-methane organic carbon in air emissions. In this research breakthrough and desorption characteristics of the microtrap were studied. A two-stage microtrap system was developed to reduce breakthrough while making sharp injection for GC separation. Microtrap was also used as a concentrator cum injector in on-line mass spectrometry. Finally, a microtrap based, continuous non-methane …


Development Of Membrane Extraction Systems For Measuring Trace Level Organic Compounds In Water, Xuemei Guo May 1999

Development Of Membrane Extraction Systems For Measuring Trace Level Organic Compounds In Water, Xuemei Guo

Dissertations

The presence of volatile organic compounds (VOCs) in ground and surface water resources poses a threat to public health. The measurement of these trace level contaminants in water is of significant importance. Conventional methods for analysis of trace volatile organic compounds in water include purge and trap, head space analysis, and solid phase microextraction (SPME). While these are excellent laboratory techniques, none of them can be used for continuous, on-line monitoring of water streams. Membrane separation of organic compounds from water provides an exciting possibility for on-line extraction and analysis. In previous investigations, water continuously flowed on the feed side …


Developing Techniques For Enhancing Comprehensibility Of Controlled Medical Terminologies, Huanying Gu May 1999

Developing Techniques For Enhancing Comprehensibility Of Controlled Medical Terminologies, Huanying Gu

Dissertations

A controlled medical terminology (CMT) is a collection of concepts (or terms) that are used in the medical domain. Typically, a CMT also contains attributes of those concepts and/or relationships between those concepts. Electronic CMTs are extremely useful and important for communication between and integration of independent information systems in healthcare, because data in this area is highly fragmented. A single query in this area might involve several databases, e.g., a clinical database, a pharmacy database, a radiology database, and a lab test database.

Unfortunately, the extensive sizes of CMTs, often containing tens of thousands of concepts and hundreds of …


Porting The Sisal Functional Language To Distributed-Memory Multiprocessors, Jui-Yuan Ku May 1999

Porting The Sisal Functional Language To Distributed-Memory Multiprocessors, Jui-Yuan Ku

Dissertations

Parallel computing is becoming increasingly ubiquitous in recent years. The sizes of application problems continuously increase for solving real-world problems. Distributed-memory multiprocessors have been regarded as a viable architecture of scalable and economical design for building large scale parallel machines. While these parallel machines can provide computational capabilities, programming such large-scale machines is often very difficult due to many practical issues including parallelization, data distribution, workload distribution, and remote memory latency.

This thesis proposes to solve the programmability and performance issues of distributed-memory machines using the Sisal functional language. The programs written in Sisal will be automatically parallelized, scheduled and …


Flame Dynamics In Steady Strained Flows, Zili Huang May 1999

Flame Dynamics In Steady Strained Flows, Zili Huang

Dissertations

In this dissertation, the response of a premixed flame to time-dependent strained flow fields is investigated. Because of the potential application to turbulent combustion modeling, the main focus is on the particular case of a flame in stagnation point flow with an imposed oscillatory strain rate. The flame is modeled as a hydrodynamic discontinuity separating burned from unburned gasses. To complete the formulation of the problem, conditions relating the fluid variables across the flame front are needed, as is a flame speed equation that determines the evolution of the discontinuity. These conditions are derived through asymptotic analysis of the flame …


Dynamical Systems Associated With Particle Flow Models : Theory And Numerical Methods, Roman V. Samulyak May 1999

Dynamical Systems Associated With Particle Flow Models : Theory And Numerical Methods, Roman V. Samulyak

Dissertations

A new class of integro - partial differential equation models is derived for the prediction of granular flow dynamics. These models are obtained using a novel limiting averaging method (inspired by techniques employed in the derivation of infinite-dimensional dynamical systems models) on the Newtonian equations of motion of a many-particle system incorporating widely used inelastic particle-particle force formulas. By using Taylor series expansions, these models can be approximated by a system of partial differential equations of the Navier-Stokes type. Solutions of the new models for granular flows down inclined planes and in vibrating beds are compared with known experimental and …


Automatic Document Classification And Extraction System (Adoces), Xuhong Li May 1999

Automatic Document Classification And Extraction System (Adoces), Xuhong Li

Dissertations

Document processing is a critical element of office automation. Document image processing begins from the Optical Character Recognition (OCR) phase with complex processing for document classification and extraction. Document classification is a process that classifies an incoming document into a particular predefined document type. Document extraction is a process that extracts information pertinent to the users from the content of a document and assigns the information as the values of the “logical structure” of the document type. Therefore, after document classification and extraction, a paper document will be represented in its digital form instead of its original image file format, …


Knowledge Management For Texpros, Jianshun Hu May 1999

Knowledge Management For Texpros, Jianshun Hu

Dissertations

Most of the document processing systems today have applied Al technologies to support their system intelligent behaviors. For the application of Al technologies in such systems, the core problem is how to represent and manage different kinds of knowledge to support their inference engine components' functionalities. In other words, knowledge management has become a critical issue in the document processing systems. In this dissertation, within the scope of the TEXt PROcessing System (TEXPROS), we identify knowledge of various kinds that are applicable in the system. We investigate several problems of managing this knowledge and then develop a knowledge base for …


Pattern Discovery In Trees : Algorithms And Applications To Document And Scientific Data Management, Chia-Yo Chang May 1999

Pattern Discovery In Trees : Algorithms And Applications To Document And Scientific Data Management, Chia-Yo Chang

Dissertations

Ordered, labeled trees are trees in which each node has a label and the left-to-right order of its children (if it has any) is fixed. Such trees have many applications in vision, pattern recognition, molecular biology and natural language processing.

In this dissertation we present algorithms for finding patterns in the ordered labeled trees. Specifically we study the largest approximately common substructure (LACS) problem for such trees. We consider a substructure of a tree T to be a connected subgraph of T. Given two trees T1, T2 and an integer d, the LACS problem is to find …


A New-Generation Class Of Parallel Architectures And Their Performance Evaluation, Qian Wang May 1999

A New-Generation Class Of Parallel Architectures And Their Performance Evaluation, Qian Wang

Dissertations

The development of computers with hundreds or thousands of processors and capability for very high performance is absolutely essential for many computation problems, such as weather modeling, fluid dynamics, and aerodynamics. Several interconnection networks have been proposed for parallel computers. Nevertheless, the majority of them are plagued by rather poor topological properties that result in large memory latencies for DSM (Distributed Shared-Memory) computers. On the other hand, scalable networks with very good topological properties are often impossible to build because of their prohibitively high VLSI (e.g., wiring) complexity. Such a network is the generalized hypercube (GH). The GH supports full-connectivity …


Modeling Controlled Vocabularies Using Oodbs And Multilevel Area Diagrams, Li-Min Liu May 1999

Modeling Controlled Vocabularies Using Oodbs And Multilevel Area Diagrams, Li-Min Liu

Dissertations

A Controlled Vocabulary (CV) is a software system of domain knowledge that consolidates and unifies the terminology of a large application domain. With a common, centralized CV, costly and time-consuming translations can be eliminated between pairs of organizations and pairs of software systems. Unfortunately, the more knowledge we put into a CV, the harder it is to understand and maintain it. In this dissertation, a comprehensive theoretical methodology for modeling CVs using Object-Oriented Database (OODB) technology is presented. We present two methods for representing a semantic network CV as an equivalent OODB, which we call an Object-Oriented Vocabulary Repository (OOVR). …


Periodicity And Disorder, Simeon D. Simeonov Apr 1999

Periodicity And Disorder, Simeon D. Simeonov

Dissertations

We have studied four examples of periodicity and disorder in nature and the phenomena associated with them.

In the first chapter of the dissertation we present an introduction to this work.

In the second chapter, the photonic band structures of two types of zinc blend structures are computed using the plane wave expansion method. Both structures are formed from an array of dielectric spheres in a vacuum background. In a first type zinc blend structure the spheres have the same size but different dielectric constants. In a second type of structure we keep the dielectric contrast of the spheres the …


Domain Architecture A Design Framework For System Development And Integration, Vassilka D. Kirova Jan 1999

Domain Architecture A Design Framework For System Development And Integration, Vassilka D. Kirova

Dissertations

The ever growing complexity of software systems has revealed many short-comings in existing software engineering practices and has raised interest in architecture-driven software development. A system's architecture provides a model of the system that suppresses implementation detail, allowing the architects to concentrate on the analysis and decisions that are most critical to structuring the system to satisfy its requirements. Recently, interests of researchers and practi-tioners have shifted from individual system architectures to architectures for classes of software systems which provide more general, reusable solutions to the issues of overall system organization, interoperability, and allocation of services to system components. These …


Parallelization For Image Processing Algorithms Based Chain And Mid-Crack Codes, Wai-Tak Wong Jan 1999

Parallelization For Image Processing Algorithms Based Chain And Mid-Crack Codes, Wai-Tak Wong

Dissertations

Freeman chain code is a widely-used description for a contour image. Another mid-crack code algorithm was proposed as a more precise method for image representation. We have developed a coding algorithm which is suitable to generate either chain code description or mid-crack code description by switching between two different tables. Since there is a strong urge to use parallel processing in image related problems, a parallel coding algorithm is implemented. This algorithm is developed on a pyramid architecture and a N cube architecture. Using link-list data structure and neighbor identification, the algorithm gains efficiency because no sorting or neighborhood pairing …


A Methodology For Component-Based System Integration, Yongming Tang Jan 1999

A Methodology For Component-Based System Integration, Yongming Tang

Dissertations

Component-based software based on software architectures is emerging to be the next generation software development paradigm. The paradigm shifts the development focus from lines-of-codes to coarser-grained components and the interconnections among them. It consists of system architecture design, architecture description, component search and system integration from components to generate a software system.

However, one of the bottlenecks in this paradigm is the integration of the individual components into the overall system. In this dissertation a methodology for component-based system integration is proposed. It is based on an architectural aggregation view, a component model, flowgraphs and cyclomatic complexity. We introduce this …


Oxidation Of Dimethyl-Ether And Ethylene In The Atmosphere And Combustion Environment And Thermodynamic Studies On Hydrofluorocarbons Using Ab Initio Calculation Methods, Takahiro Yamada Jan 1999

Oxidation Of Dimethyl-Ether And Ethylene In The Atmosphere And Combustion Environment And Thermodynamic Studies On Hydrofluorocarbons Using Ab Initio Calculation Methods, Takahiro Yamada

Dissertations

Reaction pathways and kinetics are analyzed on CH3OC·H2 unimolecular decay and on the complete CH3OC·H2 + O2 reaction system using thermodynamic properties (ΔHf°298, S°298, and C(T) 300≤T/K≤1500) derived by two ab initio calculation methods, CBS-q and G2. These are used to determine thermodynamic properties of reactants, intermediate radicals and transition state (TS) compounds. Quantum Rice-Ramsperger-Kassel (QRRK) analysis is used to calculate energy dependent rate constants, k(E), and master equation is used to account for collisional stabilization. Comparison of calculated fall-off with experiment indicates that the CBS-q and …


A Theoretical Study Of Bubble Motion In Surfactant Solutions, Yanping Wang Jan 1999

A Theoretical Study Of Bubble Motion In Surfactant Solutions, Yanping Wang

Dissertations

We examine the effect of surfactants on a spherical gas bubble rising steadily in an infinite fluid at low and order one Reynolds number with order one and larger Peclet numbers. Our mathematical model is based on the Navier-Stokes equations coupled with a convection-diffusion equation together with appropriate interfacial conditions. The nonlinearity of the equations and boundary conditions, and the coupling between hydrodynamics and surfactant transport make the problem very challenging.

When a bubble rises in a fluid containing surface-active agents, surfactant adsorbs onto the bubble surface at the leading edge, convects to the trailing edge by the surface flow …