Physical Sciences and Mathematics Commons^™

Reductive Dehalogenation Of Chlorinated Aromatic And Aliphatic Hydrocarbons Under Anaerobic Conditions, Monica Turner Togna

Dissertations

The process of reductive dehalogenation involves the removal of a halogen substituent from a molecule with the concurrent addition of electrons to the molecule, resulting in a more reduced and often less toxic product. Anaerobic bacteria have the potential to utilize hazardous chlorinated aromatic and aliphatic hydrocarbons as electron acceptors in metabolic reductive dehalogenation processes.

In experiments performed with chlorinated aromatic compounds a highly enriched anaerobic culture stoichiometrically converted 2,4,6-trichlorophenol (2,4,6-TCP) to 4-monochlorophenol. Dehalogenation occurred only in alkaline media (pH 8-9) at concentrations of 2,4,6-TCP up to 1 mM. Data indicated that the dehalogenating organism did not fit into any …

Scaling Up Of Water-Based Organic Reactions, Chen Gu

Dissertations

Three water-based organic reactions, Diels-Alder, epoxidation of olefins, and free-radical bromination have been investigated as an approach to pollution prevention. The first two systems were scaled-up by at least a factor of 20. These reactions are of special interest to the pharmaceutical and speciality chemical industries. The photo-induced free-radical bromination of alkanes with bromine in water was studied in a two-phase system. Experimental results show that all reactions have advantages resulting from being conducted in water, such as reaction rate acceleration, reaction selectivity increase, and the absorption of water-soluble gas byproduct by solvent water.

The effects of stirring rates, temperature, …

Effect Of Vitamin Supplementation On Biodegradation Of Aliphatic Hydrocarbons And Diesel Fuel, Susmita Guptapal

Dissertations

Bioremediation of hazardous wastes is proven to be environmentally benign and most cost effective technology when proper conditions are provided. However, commercialization of this method still requires comprehensive research to enhance the degradation rate to make the technology more acceptable for implementation. In this research a unique approach to increase the rate of biodegradation by vitamins supplementation was studied.

Five vitamins, niacin, biotin, folic acid, thiamin and pantothenic acid were selected for the present study. Different short chain (C₈ and C₉), and long chain (C₁₆ and C₁₇) aliphatic hydrocarbons and diesel fuel (a mixture …

Factors That Influence Changes In Temporal And Spatial Accumulation Of Debris On An Estuarine Shoreline, Cliftwood Beach, New Jersey, Usa, Laura Pace

Theses

A field investigation was conducted on an estuarine shoreline in Raritan Bay, New Jersey to identify the temporal and spatial distribution changes in accumulation of marine debris, and the factors that influence these changes. Methodology consists of 12-monthly collections of debris and profile data, and collection of local climatological and tide data. Debris was classified by type, length, weight, fragmentation, and probable function and weathering noted for each collected item. Wind roses were constructed to determine dominant wind speed and direction and wind characteristics for time intervals between field sampling.

Plastics are the primary component of debris; glass and styrofoam …

The Effect Of Deposition Of H2s On The Catalyst Activity Of 1.5 % Pt On [Gamma]-Al2o3, Ping Zhu

Theses

The impact of hydrogen sulfide (H₂S) pretreatment on the oxidation activity of powdered 1.5% Pt/γ-AL₂O₃ catalyst was investigated in this study. Fresh 1.5% Pt/γ-Al₂O₃ catalyst was aged with different concentrations of H₂S in air at 400 °C for 24 hours. Then, the aged and fresh catalysts were tested to determine the oxidation activity with diagnostic gases which contained either 1% propane or 1% carbon monoxide in dry air. The test results indicated that the catalysts were deactivated for carbon monoxide oxidation and promoted for propane oxidation as a function of …

Surface Phenomena On The Tin-Dioxide Polycrystalline Layers, Andrei A. Fluerasu

Theses

Polycrystalline tin-dioxide is widely used in the detection of reducing gases (such as H₂, CO, CH₄, C₂H₅OH,...) in air by measuring its conductivity changes. The advantage of gas sensors based on such sensing devices is low cost and high sensitivity. In contrast to their widespread applications and to their successful empirical research and development work, the present understanding of the chemical sensing mechanisms is still immature.

In this thesis, for gas sensors based on thick and porous tin-dioxide layers, a study of the response function upon variation of the partial pressure of …

Oodini 2.1 : An Enhanced Graphical Schema Representation For Object-Oriented Database, Rajashekar Rao

Theses

The graphical representation of an object-oriented database (OODB) schema is useful for the designers and users of a database system. The purpose of my thesis was to enhance the existing version of OOdini, an interactive graphical tool for editing an OODB schema. The new features include interactive modification and description of objects in the schema. Data structures for representing classes and attributes have been altered to incorporate object/data types as well as a descriptive string. The software has been implemented using the ObjectMaker toolkit to design our own methodology using the ObjectMaker Extension Language.

Towards Designing A Knowledge-Based Tutoring System : Sql-Tutor As An Example, Gang Zhou

Dissertations

A Knowledge-Based Tutoring System, also sometimes called an Intelligent Tutoring System, is a computer based instructional system that uses artificial intelligence techniques to help people learn some subject. The goal of the system is to provide private tutoring to its students based on their different backgrounds, requests, and interests. The system knows what subject materials it should teach, when and how to teach them, and can diagnose the mistakes made by the students and help them correct the mistakes.

The major objective of this dissertation is to investigate and develop a generic framework upon which we can build a Knowledge-Based …

Pattern Discovery In Sequence Databases : Algorithms And Applications To Dna/Protein Classification, Gung-Wei Chirn

Dissertations

Sequence databases comprise sequence data, which are linear structural descriptions of many natural entities. Approximate pattern discovery in a sequence database can lead to important conclusions or prediction of new phenomena. Traditional database technology is not suitable for accomplishing the task, and new techniques need to be developed.

In this dissertation, we propose several new techniques for discovering patterns in sequence databases. Our techniques incorporate pattern matching algorithms and novel heuristics for discovery and optimization. Experimental results of applying the techniques to both generated data and DNA/proteins show the effectiveness of the proposed techniques.

We then develop several classifiers using …

Knowledge Discovering For Document Classification Using Tree Matching In Texpros, Ching-Song Wei

Dissertations

This dissertation describes a knowledge-based system for classifying documents based upon the layout structure and conceptual information extracted from the content of the document. The spatial elements in a document are laid out in rectangular blocks which are represented by nodes in an ordered labelled tree, called the "layout structure tree" (L-S Tree). Each leaf node of a L-S Tree points to its corresponding block content. A knowledge Acquisition Tool (KAT) is devised to create a Document Sample Tree from L-S Tree, in which each of its leaves contains a node content conceptually describing its corresponding block content. Then, applying …

Integrating Hypertext With Information Systems Through Dynamic Mapping, Jiangling Wan

Dissertations

This dissertation presents a general hypertext model (GHMI) supporting integration of hypertext and information systems through dynamic mapping. Information systems integrated based on this model benefit from hypertext function-alities (such as linking, backtracking, history, guided tours, annotations, etc.) while preserving their own computation capabilities. Although systems supporting integration of hypertext and interface-oriented information systems do exist in hypertext literature, there is no existing model or system effectively supporting integration of hypertext and computation-oriented information systems. GHMI makes its major contributions by both extending and specifying the well-known Dexter Hypertext Reference Model. GHMI extends the Dexter model to overcome its limitations. …

Theory And Design Of Portable Parallel Programs For Heterogeneous Computing Systems And Networks, Ying-Chieh Wu

Dissertations

A recurring problem with high-performance computing is that advanced architectures generally achieve only a small fraction of their peak performance on many portions of real applications sets. The Amdahl's law corollary of this is that such architectures often spend most of their time on tasks (codes/algorithms and the data sets upon which they operate) for which they are unsuited. Heterogeneous Computing (HC) is needed in the mid 90's and beyond due to ever increasing super-speed requirements and the number of projects with these requirements. HC is defined as a special form of parallel and distributed computing that performs computations using …

Continuous Monitoring Of Volatile Organic Compounds Using Microtrap Based Gas Chromatographic Systems, Yonghua Xu

Dissertations

Continuous analysis allows a representative portion of a sample to flow continuously through an analytical instrument, which gives analytical information with little or no delay in time. A microtrap is a small diameter tube packed with adsorbents in series. When a gaseous sample containing volatile organic compounds (VOCs) flows through the microtrap, the VOCs can be trapped selectively by adsorbents. Then a pulse of electrical current is applied to the microtrap. This rapid heating results in a desorption that can act as a sharp injection for GC separation. Thus the microtrapped sample is the total amount of VOC present in …

Stratospheric Ozone Layer Depletion : A Computer Aided Case Study, James M. Lipuma

Theses

In industries today, there is a desire to stop pollution before it starts, through the process of pollution prevention. Unfortunately, many university level students are not exposed to the thinking process involved in environmental problem solving early enough in their academic career, if they are exposed to it at all. The goal of this thesis is to develop and to evaluate an interdisciplinary case-study about the depletion of the stratospheric ozone layer by chlorofluorocarbons (CFCs). This case-study will be used to teach first year chemistry students about environmental problem solving. The case study was assembled from existing literature according to …

Design And Fabrication Of A Miniature Pressure Sensor Head Using Direct Bonded Ultra-Thin Silicon Wafers, Chad Eugene Statler

Theses

A miniature pressure sensor head is designed and fabricated using an ultra-thin silicon membrane directly bonded to an excimer laser micromachined substrate. The pressure sensor head has its intended implementation as part of an optically interrogated device with sensitivity to pressures ranging from 0.5 to 4.0 MPa. The pressure range design is shown to be easily adjusted by tailoring the thickness of the membrane wafer. The fabrication process features numerous advantages over existing pressure sensor construction technology including a maskless procedure and no chemical etching or mechanical thinning necessary to form the membrane after bonding. An optic lever is constructed …

Degradation And Breakdown In Ultra-Thin Silicon Oxides, Christopher Franck

Theses

Emerging trends in the semiconductor device industry call for detailed knowledge of the properties of devices whose dimensions are small enough to exploit Quantum Mechanical effects. This thesis presents a complete picture of oxide degradation in MOS direct tunnel diodes (t0 <3.4 nm). It is demonstrated that for structures fabricated at different facilities and stressed with either gate or substrate injection, a universal degradation mode is revealed which is manifested as the build up of positive charge in the oxide. The data gathered demonstrates that the positive charging phenomena in sub-3.5 nm oxides is independent of oxide thickness, and is characterized by a voltage threshold and two-regime temperature dependence. Further, the catastrophic failure, or breakdown, of these oxides was studied and the strongest evidence to date is presented which links the positive charging phenomena to the oxide breakdown. This thesis concludes with the presentation of a novel device design which can exploit the properties of degradation and breakdown, in thin oxides, to achieve an EEPROM memory cell of superior endurance.

Pollution Prevention In The New Jersey Chemical Industry : Motivations And Barriers To Commitment, Judith A. Thornton

Theses

This study of the New Jersey Chemical Industry identifies the primary elements that lead to or inhibit company commitments to pollution prevention. A direct measure of facility pollution prevention commitment is developed that takes into account: organizational support attributes, past reductions achievements, current methods implementation, process reduction goals, and special environmental initiatives. The "P2 Commitment Index" allows for categorization of facilities so that the needs and interests of varying groups may be differentiated.

Higher level commitments are associated with: establishment of company pollution prevention policy, setting of prioritized facility goals, and measurement and reporting on pollution prevention progress. Facilities at …

Speciation And Determination Of Trace Lead : Methodology Development And Analysis Of Natural Waters Using Chelex-100 And Gfaas, Xidan Ma

Theses

The development of a method for speciation, preconcentration, and determination of lead was successfully conducted using Chelex-100 and graphite furnace atomic absorption spectroscopy (GFAAS). Sorption under static conditions and direct measurements in the bead slurry or after fast elution of lead from beads with HNO3 solution was used. The effects of buffers, sorption kinetics, filtration criteria, sample concentration, resin particle size and temperature program for the GFAAS were carefully studied. In this study, synthetic aqueous samples containing lead were preconcentrated under static conditions using the ion exchange resin, Chelex-100, and the resin was directly analyzed using GFAAS. The batch preconcentration …

The Reactions Of Nox With Diesel Soot Over Cu-Zsm-5 Catalyst, Shu Sun

Theses

Air pollution from the exhaust of Diesel engines consisting of relatively high concentrations of NO_x and particulates is a difficult problem to overcome because no fully effective technology to control these emission is available. The existing methods to reduce NO_x and soot can not satisfy the provisions of the 1990 CAAA (Clean Air Act Amendment). Cu-ZSM-5, a catalyst in which Cu has been ion-exchanged with H+, can catalyze the decomposition of NO to N₂ and O₂ and reduction to N₂ and O₂ with light hydrocarbons such as propene or Diesel soot in the presence …

Oxidation Of Isobutane And Isobutene Reaction Pathways And Detailed Mechanism, Chiung-Ju Chen

Theses

A reaction mechanism consisting of 248 elementary reactions and 138 species has been developed to model experimental systems - decomposition of 2,2,3,3 tetramethylbutane in the presence of oxygen and oxidation of isobutene. This elementary reaction mechanism based on two important reaction systems: tert-butyl radical with O₂ and allylic isobutenyl radical with O₂, plus their subsystems, such as isobutene + HO₂, isobutene + OH and allylic isobuteny1hydroxy + O₂. Thermochernical kinetic parameters are developed for each elementary reaction and a chemical activation kinetic analysis using quantum RiceRamsperger-Kassel (QRRK) theory for k(E) and modified strong …

Identifying And Exploiting Concurrency In Object-Based Real-Time Systems, Guohui Yu

Dissertations

The use of object-based mechanisms, i.e., abstract data types (ADTs), for constructing software systems can help to decrease development costs, increase understandability and increase maintainability. However, execution efficiency may be sacrificed due to the large number of procedure calls, and due to contention for shared ADTs in concurrent systems. Such inefficiencies are a concern in real-time applications that have stringent timing requirements. To address these issues, the potentially inefficient procedure calls are turned into a source of concurrency via asynchronous procedure calls (ARPCs), and contention for shared ADTS is reduced via ADT cloning. A framework for concurrency analysis in object-based …

Investigation Of Potential Oxygen Defect Mechanism Of Persistent Photoconductivity And Photoinduced Superconductivity In Yba2cu3ox, Denise Catherine Chew

Theses

In this thesis work, we conclude that oxygen vacancy defects play a fundamental role in the PPC/PISC mechanism and identify the oxygen defects as F centers (an oxygen vacancy which traps two electrons) or F⁺ centers. Also, the correlation between the peaks observed in the luminescence spectra and those observed in the wavelength dependence of PPC suggest that the photogeneration of charges and their annihilation via luminescent recombination occur in the same level (Cu-O chains) of the YBa₂Cu₃O_x crystal. Previous models had assigned the peaks in the PPC excitation spectrum to charge transfer in …

Construction Of Accurate Molecular Models Using Laser Stereolithography And Determination Of Nmr Spectra For Amiloride Hydrochloride And Its Free Base, Ana Deborah Ofsievich

Theses

Accurate molecular models were constructed by a rapid prototyping process, called stereolithography. This process uses a computer-controlled laser to cure and solidify a photosensitive liquid polymer. Using a computer-aided design (CAD) program, spheres of appropriate van der Waals or CPK radii were drawn and placed in the three dimensional CAD space, in accordance with the atomic coordinates obtained from quantum mechanical calculations and from neutron diffraction data. These design data were used to drive the stereolithography system where the models were built in the same shape as the CAD image. The models built for the purpose of this work consisted …

Continuous Monitoring Of Volatile Organic Compound Emissions Using Microtrap Based Injection Technique And Gas Chromatography, Wenjun Chen

Theses

A microtrap is made by packing a small diameter tubing with an adsorbent. The microtrap can be rapidly heated with a pulse of electrical current resulting in a sharp desorption that can act as an injection for GC separation. The microtrap can be used in several configurations to concentrate and inject sample in continuous, on-line monitoring system.

In this research a laboratory scale catalytic incinerator was set up and volatile organic compounds in the incinerator effluents were monitored using the microtrap based injection systems. The detection systems used were gas chromatography and nonmethane organic carbon (NMOC) analyzer. Conventional sample valve, …

The Effects Of Chromated Copper-Arsenate (Cca) Pressure-Treated Wood On Local Sediments And Benthos In A Freshwater Lake, William A. Romeo

Theses

This study looked at the sediment and benthic organism effects of exposure to a Chromated Copper-Arsenate (CCA) treated wood bulkhead in a lake environment with respect to 1) the leaching and accumulation of chromium, copper and arsenic in the nearby sediments, 2) accumulation of these metals in local benthic organisms and 3) the effects of these metals on the local benthic community structure. Sediment samples, taken at regular distances away from a CCA bulkhead and three reference areas in a freshwater lake in Wayne, NJ, were sieved to remove the fine particle fraction (<70µm) which was then analyzed for the metals of concern. Benthic organisms were sampled at the same locations, enumerated, identified, dried and also analyzed for the metals in question. Analysis of sediment metal concentrations revealed high levels of copper at all sampling locations. This was attributed to the annual addition and accumulation Of CuS0₄ added to the lake. There …