Digital Commons Network^™

Dmodel And Dalgebra : A Data Model And Algebra For Office Documents, Fortune Solani Mhlanga

Dissertations

This dissertation presents a data model (called D_model) and an algebra (called D_ algebra) for office documents. The data model adopts a very natural view of modeling office documents. Documents are grouped into classes; each class is characterized by a "frame template", which describes the properties (or attributes) for the class of documents. A frame template is instantiated by providing it with values to form a "frame instance" which becomes the synopsis of the document of the class associated with the frame template. Different frame instances can be grouped into a folder. Therefore, a folder is a set of frame …

Characterization Of Advanced Etching Reactors Using Novel Diagnostic Tools, Vipulkumar Patel

Dissertations

Plasma etching equipment used for sub-micron integrated circuit fabrication at present are exclusively based on 13.56 MHz, capacitively coupled, parallel-plate geometry. The underlying mechanisms of plasma processes in these reactors are not well understood and there is even less understanding of how the etch-tool parameters relate to the plasma discharge characteristics which actually determine the etch process. In this thesis, new diagnostic techniques were applied for the characterization and optimization of plasma etching processes in various reactor configurations.

Specifically, diode and triode configurations were studied extensively using tuned scanning Langmuir probes. Both radial and axial distributions of plasma density were …

Kinetic Study Of Decomposition Of Azo Dyes And Phenol In Advanced Oxidation Processes Reaction Mechanisms, Pathways And Intermediates, Hung-Yee Shu

Dissertations

Advanced Oxidation Processes (AOP) are an emerging technology for treatment of various hazardous organics in wastewater and groundwater. However, the kinetics and mechanisms for AOP have not been well understood. A mechanism including light intensity was studied for the decomposition of azo dyes and phenol in an AOP reactor with a 5,000 watt low pressure mercury lamp. UV light absorption is an important parameter. The effect of pH, hydrogen peroxide dosage, and dye concentration on the decomposition of azo dyes in an H₂O₂/UV reactor were also studied. Reaction pathways and intermediates of phenol oxidation by different …

Unreinforced Masonry Structures : Nonlinear Analysis And Evaluation Of Some Rehab Schemes, Sanjay Mehta

Dissertations

Unreinforced masonry (URM) structures have been a common type of construction in the past and are still used in regions of low seismicity. Retrofitting of these structures is necessary because of two reasons: Firstly, observed damage after earthquakes reveals that URM construction is one of the most hazardous constructions even in the region of low seismicity; secondly, reclassification of seismic zones would require retrofitting of existing structures to comply with new guidelines for earthquake design.

Retrofitting measures require that the response of original and new structural systems as well as their interaction be considered. It is therefore important to correctly …

Megsdf Mega-System Development Framework, Tamar Zemel

Dissertations

A framework for developing large, complex software systems, called Mega-Systems, is specified. The framework incorporates engineering, managerial, and technological aspects of development, concentrating on an engineering process. MegSDF proposes developing Mega-Systems as open distributed systems, pre-planned to be integrated with other systems, and designed for change.

At the management level, MegSDF divides the development of a Mega-System into multiple coordinated projects, distinguishing between a meta-management for the whole development effort, responsible for long-term, global objectives, and local managements for the smaller projects, responsible for local, temporary objectives.

At the engineering level, MegSDF defines a process model which specifies the tasks …

Utilization Of Fly Ash In Concrete, Chai Jaturapitakkul

Dissertations

Fly ash, a by-product of coal burning power plants, is produced in large quantities each year. It is commonly known that fly ash possesses pozzolanic behavior which can enhance the properties of concrete. Due to a lack of proper understanding on the formation of fly ash and its performance in concrete, the question of quality assurance has frequently been a major concern of engineers using fly ash in their construction projects. As a result, much fly ash is disposed of as waste material in landfills. Recent environmental concerns and a shortage of landfill space have rapidly escalated the disposal cost …

Competition Between Two Microbial Populations In A Sequencing Fed-Batch Reactor And Its Implications For Waste Treatment Applications, Sitaram Dikshitulu

Dissertations

Pure and simple competition between two microbial populations in a sequencing fed-batch reactor (SFBR) was studied both at the theoretical and experimental level. Competition occurred for a single chemical pollutant which could serve as the sole carbon and energy source for both competitors. A mathematical model describing the process under inhibitory kinetics (as is usually the case with hazardous and toxic substances) was derived and theoretically analyzed. The model predicts that the dynamics of a SFBR, and the kinetics of biodegradation, result in a complex set of operating regimes in which neither species, only one species, or both species survive …

Analysis Of The Optimum Extraction System Design For The Separation And Purification Of Rare Earths, Kenneth Yeon-Kang Chan

Dissertations

A mathematical model for the liquid-liquid equilibrium of the lanthanide and yttrium oxides in the nitric acid - water - tributyl phosphate (HNO₃-H₂O-TBP) two-phase system has been developed. This model is based on the interrelationships of chemical reactions, phase equilibrium, and material balance. The chemical reactions were modelled using experimentally derived empirical equations for components involved. The distribution coefficients of 16 rare earths which were experimentally determined. by UK Harwell Laboratory were used to evaluate the parameters of this equilibrium model. Once model parameters are determined, material balance for all species in the HNO₃-H …

Analysis Of A Band-Saw, Suat Ali Ozsoylu

Dissertations

The solution for the transverse oscillations of a band-saw is determined. Two different models are treated: a fourth-order model and a second-order model. The response characteristics for both models are determined using Laplace transformation. To obtain the inverse Laplace Transform for the fourth-order model, it was necessary to fmd the frequencies by applying the Extended Lanczos Method in order to overcome the problem for computer overflow.

The limits of stability for both models are studied by plotting the eigenvalues against changing parameter values. Conditions for the onset of divergence and flutter instabilities, which need to be taken into account in …

Kinematic Synthesis Of Adjustable Four-Bar Mechanisms For Multi-Phase Motion Generation, Shao Jie Wang

Dissertations

A four-bar linkage can satisfy up to five prescribed positions for the motion generation problem. The adjustable four-bar linkage, on the other hand, can satisfy more than five given positions by making some of the parameters adjustable.

Limited work had been done in the area of motion generation problems of kinematic synthesis of adjustable four-bar linkages until Wilhelm introduced the concept of multiple adjustments.

This study considers for the first time, the adjustment of a moving pivot, and the problems of three phases of motion. Various combinations of the number of prescribed positions for the motion generation problems are solved …

Study Of Surface Properties Produced By Magneto-Plasma On Nitriding For Improving Wear Resistance, I-Tsung Shih

Dissertations

In this work a newly developed surface treatment process, Magneto-Plasma Ion Nitriding process, was developed and studied. This process was developed to increase durability and wear resistance of operational surfaces of different machine components.

In this study, orthogonal experimental analysis was used to develop, optimize, and select the process parameters. Coating layers were characterized and studied by using scanning electron microscopy(SEM), Auger electron spectroscopy(AES), and image analysis system. The influence of different process treatment parameters, such as temperature, nitrogen concentration, and magnetization, on the layers properties was studied. The mechanism of layer formation and bonding was proposed and a mathematical …

Investigation Of The Striation Formation In The Course Of Abrasive Waterjet Cutting, Jo-Fei Chao

Dissertations

The principal defect of the surfaces generated by abrasive waterjet machining is excessive waviness (striation). The existing theories of striation formation are not adequate to explain this phenomenon. The presented study is concerned with the development of an understanding of the mechanism of striation formation.

A spectral analysis of temporal process and spatial surface characteristics demonstrated that the striation is caused by nozzle vibration that is due to the conditions of the motion control of the nozzle. This enabled us to discover a means for improving the surface finish. From a study of the surface spectra, it was found that …

Investigation Of The Consumer Electronics Bus, Jaesoo Yang

Dissertations

The objectives of this dissertation are to investigate the performance of the Consumer Electronics Bus (CEBus) and to develop a theoretical formulation of the Carrier Sense Multiple Access with Contention Detection and Contention Resolution (CSMA/CDCR) with three priority classes protocol utilized by the CEBus

A new priority channel assigned multiple access with embedded priority resolution (PAMA/PR) theoretical model is formulated. It incorporates the main features of the CEBus with three priority classes. The analytical results for throughput and delay obtained by this formulation were compared to simulation experiments. A close agreement has been found thus validated both theory and simulation …

On Adaptive Censored Cfar Detection, Loizos Anastasiou Prastitis

Dissertations

In an automatic radar detection system the received signal in every range resolution cell is compared with a threshold to test for the presence of a target. A Neyman-Pearson type test is used which maximizes the probability of detection for a fixed probability of false alarm. For the simple case where the noise is homogeneous a fixed threshold is chosen to achieve the designed constant false alarm rate (CFAR). In the more realistic case the noise background is non-stationary due to clutter and interference. In this situation, the threshold used for testing a particular cell is usually set adaptively using …

Investigation Of Reactor Design Parameters Towards Optimizing Biodegradation Of Chlorophenols By Phanerochaete Chrysosporium, Nirupam Pal

Dissertations

The biodegradation of 2,4,6-trichlorophenol (246-TCP) and 2,4,5-trichiorophenol (245-TCP) by Phanerochaete chrysosporium was studied in batch and in continuous systems. Contrary to most of the previous reports from the literature, this study shows that degradation of both TCPs can occur in the absence of any measurable ligninase activity. The microorganism did not retain its degradative ability for more than about two weeks

In order to better understand the degradation process, the individual contributions of both the biomass and the extracellular proteins were studied separately. The results show that neither the biomass nor the extracellular proteins alone can completely degrade 246-TCP, but …

An Investigation Of The Relationship Among Self-Efficacy Beliefs, Goal Setting, And Academic Performance Of Students In A Transition To High School Program, Cheryl Kinsman

Dissertations

No abstract provided.

Faculty Perceptions Of The Role Of Department Chairperson In Facilitating Tenure Acquisition, Frances Daly

Dissertations

No abstract provided.

The Dunne School Board : Reform In Chicago, 1905-1908, Mary Schiltz

Dissertations

No abstract provided.

Perceived Leadership Style, Style Flexibility, And Style Effectiveness Of Government Hospital Administrators In Thailand, Pongsin Chuwattanakul

Dissertations

Problem. Many health care organizations have a great need for leaders who can handle the complex mix of health care facilities, legal and patient demands. Currently, hospital administrators of government-operated hospitals in Thailand are selected from physicians. These physicians are not directly trained to be professional hospital administrators. It was the purpose of this study to study and reveal their leadership styles.

Method. A descriptive design was used to study the leadership styles, style flexibility, and style effectiveness of hospital administrators in self-reports and as perceived by supervisors. The LBA II-Self (Leader Behavior Analysis II: Self Perceptions of Leadership Style) …

A Comparative Study Of The Perceived Needs And Learning Styles Of Generic Nursing Students And Registered Nurse Students In Selected Baccalaureate Programs, Pamela A. Bachmeyer

Dissertations

No abstract provided.

The Articulation Of The National Teacher Education Department To Teachers Colleges In Thailand: A History, 1954-1984, Boon-Anan Phinaitrup

Dissertations

No abstract provided.

The Origins And Development Of Evening Undergraduate Education In Chicago, 1891-1939, Sandra Averitt Cook

Dissertations

No abstract provided.

A Case Study Of The Steinmetz Academic Centre For Wellness And Sports Science : Differential Program Preference Ratings By Group Constituency, Race, And Gender, Kay Tokunaga

Dissertations

No abstract provided.

Towards A Comprehensive And Integrated Sex Therapy Information System, Donald T. Mon

Dissertations

No abstract provided.

Effect Of Product Branding, Age And Sex Of Rater, And Type Of Judgement On Presentation Order Bias In Paired Comparison Taste Testing, George Webster Hunt

Dissertations

No abstract provided.

A Continuous Culture Model To Examine Factors That Affect Transduction Among Pseudomonas Aeruginosa, Jean Replicon

Dissertations

No abstract provided.

History Of The Chicago Parental School, 1902-1975, Cynthia Kay Barron

Dissertations

No abstract provided.

An Analysis Of Student Affairs Budget Allocation Practices From 1984-1988 At Urban Public Research Universities, Michael H. Ginsburg

Dissertations

No abstract provided.

Solution Options To The Problem Of Growth/Overcrowding As It Manifests Itself In Illinois' Public Schools, Teddy Stephen Struck

Dissertations

No abstract provided.

Computational Neural Networks In Chemistry: Model Free Mapping Devices For Predicting Chemical Reactivity From Molecular Structure, David Wayne Elrod

Dissertations

Computational neural networks (CNNs) are a computational paradigm inspired by the brain’s massively parallel network of highly interconnected neurons. The power of computational neural networks derives not so much from their ability to model the brain as from their ability to learn by example and to map highly complex, nonlinear functions, without the need to explicitly specify the functional relationship. Two central questions about CNNs were investigated in the context of predicting chemical reactions: (1) the mapping properties of neural networks and (2) the representation of chemical information for use in CNNs.

Chemical reactivity is here considered an example of …