Physical Sciences and Mathematics Commons^™

Evaluation Of Carcinogenic Potential Of Benzo(Α)Pyrene And Dimethylbenzanthracene In Mouse Leukemic Cells, Mohammad Sharif Sultan Al Ulama

Theses

The carcinogenic potential of benzo[α]pyrene (B(α)P) and dimethylbenzanthracene (DMBA) was tested using mouse leukemic cell lines L-5178 R and S types in tissue culture condition. It was found that B(α)P and DMBA inhibited the synthesis of DNA of R and S types of cells to about 34%, at 10 mM concentration. While B(α)P and DMBA did not show any acute toxic effect on mouse cell line Rand S types at 1 mM concentration separately. Both R and S types of cells were allowed to grow for several days in the presence of 1 mM DMBA and B(α)P respectively. Several independent …

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.

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 …

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 …

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 …

Hepatic Cytochromes P450 Enzyme Activities Of Uae Coastal Rabbit Safi Fish Siganus Canaliculatus, Amna Mana Al-Otaiba

Theses

The cytochrome P450 dependent metabolism of benzo(a)pyrene and other xenobiotics has been investigated in liver microsomes prepared from a local marine Safi fish Siganus canaliculatus caught from the Arabian Gulf of United Arab Emirates. The Safi fish was found to have a well developed liver microsomal monooxygenase system consisting of cytochrome P450, cytochrome b5 and NADPH-cytochrome c reductase. The fish microsomal enzyme system was able to metabolise benzo(a)pyrene, 7-ethoxycoumarin and 7- ethoxyresorufin. Male fish were found to exhibit a higher monooxygenase activity than female fish. Treatment of fish with β-naphthoflavone was found to induce (2-4 fold) the activities of aryl …

Environmental Study Indoor And Outdoor Of The Abu Dhabi Compost Plant, Jaber Eidha S. Aljabri

Theses

The transformation of municipal solid waste into compost is of double interest: on the one hand, it helps to avoid the deficiencies of natural manure, and on the other it eliminates this major polluting agent which is increasing progressively as a consequence of rising populations.

Domestic waste produced per person per annum amounts to 730 kg in Abu Dhabi city. Based on a population in 1992 of 574,745, this gives a current daily refuse collection that amounts to 1120 tons. Refuse is reported to contain a high proportion of organic materials and therefore to be suitable for recycling to produce …

Fluorescent Labeling Technique And Dna Amplification By The Polymerase Chain Reaction For The Detection Of Human Malaria Parasites., Maryam Mohd Ai-Shaikh Omer Ai-Ameri

Theses

The polymerase chain reaction (PCR) and fluorescence staining based diagnosis of Malaria infection was attempted. 187 samples in two groups: 135 and 52 patients Attending the Malaria Clinic (preventive Medicine and Al-Ain Hospital, UAE) were Collected Two PCR systems; using small subunit ribosomal RNA (ssrRNA) based primers And merozoite surface antigen (MSP) based primers were assessed, taking the Giemsa Stain as the reference test.

The re sults of PCR using the merozoite surface antigen (MSP) primers specific for Pfalciparum, proved to be specific and accurate. These results were analyzed by agarose gel electrophoresis (AGE) and polyacrylamide gel electrophoresis (page) stained …

Application Of Tube Settlers In Secondary Wastewater Treatment, Abdulsalam Mohamed Saleh Kamalpoor

Theses

Secondary sedimentation is one of the most commonly used unit operations in wastewater treatment plants. It is customary designed to achieve solids separation from biologically treated effluent through clarification of biological solids and thickening of sludge. As treatment plants receive increasingly high wastewater flow, conventional sedimentation tanks suffer from overloading problems which result in poor performance. Inclined plate settlers, a form of tube settlers, may have good potential in upgrading sedimentation tanks. This study was conducted to examine the possibility of applying inclined plate settlers in secondary sedimentation in order to upgrade conventional rectangular sedimentation tanks and improve their performance. …

Environmental Management And Treatment Of Oily Water In Abu Dhabi Offshore Oil Fields, Mohamed Ali Saeed Al-Nuaimi

Theses

The purpose of this environmental case study is to evaluate the oily water treatment efficiency in the separation of oil from water in relation to the environmental impact to the marine environment. This study covers offshore oil fields production facilities in the Abu Dhabi Emirate. The study discusses the most commonly used methods in the separation of oily water disposals. It highlights in detail the different types of treatment systems currently in use at Abu Dhabi offshore oil fields production facilities. Emphasis is given to the performance of each treatment system, its deficiencies and possible areas of improvement.

The study …

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 …

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 …

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 …

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 …

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.

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 …

Extraction, Recovery And Separation Of Some Organic And Inorganic Pollutants By Polyurethane Foams And Other Extracting Agents, Mahboob Hassan Saleh

Theses

Many substances pollute the marine and air environments but non-biodegradable compounds are the most dangerous. Heavy metals and most of the pesticides are known for their high toxicity. Mercury and lead in particular tend to accumulate in liver and kidney and inhibit the biosynthesis of heme protein because of their affinity for thiol and phosphate containing ligands. Thus, it affects the permeability of the membranes of kidney, liver and brain cells. Soluble inorganic mercury (II) species can be transformed into methylmercury under aerobic conditions by the actions of microorganisms. The target organ of methylmercury in humans is the brain where …

Environmental Air Pollution Analysis In Selected Areas Of Abu Dhabi Emirate, Mahfoodh Abdulla Mohammed Darbool

Theses

There are little data available for environmental pollution, as well as air pollution and statistical information published in the United Arab Emirates. Especially, Abu Dhabi Emirate, has been the location of the UAE's most persistent and extreme levels of industrial oil waste and chemical smog and air pollutants which produces sulphur dioxide emission. In addition, has a high vehicle population, which produces carbon monoxide emission from the motor vehicle exhaust. The acute toxicity of carbon monoxide (CO) has long been recognized and well documented. The motor vehicle is by far the largest contributor to Co accounting for 55% of total …

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 …

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 …

Comparative Study Of Some Physiological And Behavioral Responses To Feed And Water Deprivation In Camels, Sheep And Goats, Huda Mohammed Shaheen

Theses

The aim of the study was to compare some physiological and biochemical responses in camels, sheep and goats when subjected to various periods of food and water deprivation. Another purpose of the study was to examine the feeding and drinking behaviour of dehydrated and starved animals when provided with food and water simultaneously. The study was performed at the Faculty of Agricultural Sciences Farm, University of United Arab Emirates, Al-Ain.

Animals were deprived of water and food for various periods; feed and water were withheld 2, 4 or 6 days in camels and 1, 2 or 3 days for sheep …

Retention And Separation Behaviour Of Chloropyrifos And Other Water Pollutants Using Polyurethane Foams, Rashed Saleh Al-Mehrazi

Theses

Heavy metals and pesticides represent a class of man-made environmental pollutants which also occur naturally in the environment. The presence of these pollutants in the industrial and agricultural wastewaters often represents a risk to the environment. Investigation of these species in the water is an important aspect of environmental pollution as human activities contributed to the progressive increase in the concentration of these compounds in the environmental as well as aquatic systems. Therefore, identification and removal (or reduction) of these species to an acceptable concentration are of prime importance.

The analytical utility of unloaded open-cell polyurethane foams and foams immobilizing …

Acidic Marine Biotoxins Implicated In Diarrhetic Shellfish Poisoning, Eoin P. Carmody

Theses

An okadaic acid (OA) etiology has been demonstrated for most outbreaks of diarrhetic shellfish poisoning (DSP) in Europe, An isomer of OA, dinophysistoxin-2 (DTX-2), has recently been found in Irish waters and, in 1991 and 1994, was the major toxin during prolonged infestations in cultivated mussels (Mytilus edulis) along the south-west coast of Ireland.

The OA class of DSP toxins have been analysed by HPLC using modified versions of three established fluorescent derivatisation methods. A ‘dual tag’ method for the confirmation of specific toxins has also been developed.

Survey work has been carried out over the past four years on …