Physical Sciences and Mathematics Commons^™

Reaction Rate Of 17f(P,Γ)18ne And Its Implications For Nova Nucleosynthesis, Suzanne Parete-Koon

Masters Theses

The rate of the 17F(p,γ)18Ne reaction has a profound effect on the abundances of several isotopes produced during a nova outburst. In 1999 a new rate for 17F(p,γ)18Ne was determined from a measurement of the excitation function for the 1H(17F,p)17F reaction at Oak Ridge National Laboratory's (hereafter ORNL) Holifield Radioactive Ion Beam Facility[1]. This experiment yielded the first definite evidence of a Jπ =3+ state in 18Ne. This state provided a new resonance in the 17F +p capture, which could, depending on its properties, dominate the rate of 17F(p,γ)18Ne at stellar explosive temperatures. The new rate for 17F(p,γ) 18Ne was …

Pan, Ppn And Mpan Measurements And The Quantitative Relationship Of Pan And Mpan In Biogenic Hydrocarbon Conditions, Chen Wangchun

Masters Theses

Simultaneous measurements of PAN, PPN and MPAN were made during the SOS 1999 Nashville campaign at Dickson site. The PANs data at this site were rich and complex. PAN and MP AN showed obvious diurnal change but PPN did not during this period. PAN and ozone have a clear positive relationship. Due to the special location of the site, winds from different directions bring anthropogenic hydrocarbons (AHCs) or biogenic hydrocarbons (BHCs) to the site. The data showed that the influence of AHCs and BHCs on PANs compounds varied on different days. Average values of PAN/PPN and PAN/MPAN from MLR may …

Characterization Of Organo-Tin And Organo-Mercury Compounds With Electrospray Mass Spectrometry, Kan Zhu

Masters Theses

Metal-containing compounds are often found as pollutants in the environment. Obtaining speciation information about these compounds is important to understanding toxieity and bioaccumulation. Electrospray Mass Spectrometry (ESMS) is a technique that has the potential to provide rapid and direct speciation information of solution phase metal compounds. The ionization behavior of chemical species is related to their electron affinities. The higher the electron affinity, the easier it will be reduced during the ionization process. Additionally, solvent with different polarity and surface tension will also affect the ionization and reduction products. Organo-tin compounds with more alkyl groups will be ionized more efficiently, …

Adaptive Simulated Annealing: An Alternative Approach For The Error Minimization Of Neural Networks, Yuxing Sun

Masters Theses

This work introduces an alternative algorithm, simulated annealing, to minimize the prediction error from neural networks that traditionally use back-propagation methods. The simulated annealing algorithm stochastically samples the parameter space formed by weights of the neural network until a minimal error is found.

Three problems were investigated in this work: the radiator problem, the spiral problem, and the time series prediction problem. Each of them was examined using the same neural network architecture, i.e., a 2-layer network, and trained by both back-propagation and simulated annealing.

The simulated annealing algorithm consumes longer computation time in searching for the global minimum than …

Alkyl Nitrates In Dickson During The Sos 1999 Field Campaign, Mei Ma

Masters Theses

Measurements of alkyl nitrates were performed during the Southern Oxidants Study (SOS) 1999 Summer Field Campaign in Dickson, TN from June 10 to July 15, 1999. The developed GC-ECD method was tested and used successfully. Nine alkyl nitrates were measured and six alkyl nitrates were quantified. The measured alkyl nitrates expect methyl nitrate showed higher mixing ratios under northeasterly and southeasterly wind, which brought anthropogenic sources to the measurement site, and lower mixing ratios when wind came from northwest and southwest, which brought NOx and clean air, respectively. The contribution of the measured alkyl nitrates to the total oxidized nitrogen …

A Qualitative Investigation Of The Polymerization Process In The Ihss Humic Substances Extraction Procedure Using Model Phenolic Compounds, Roger J. Germay

Masters Theses

Achard (1786) extracted peat with alkali and reported obtaining dark compounds now called humic substances. These are complex, high molecular weight, polyphenolic compounds naturally occurring in soil, in fresh-water and in marine environments. They are biodegradation products of plant materials.

The International Humic Substances Society (IHSS) adapted Achard's method to separate humic substances into three fractions: (1) humic acids (HA), soluble only at high pH; (2) fulvic acids (FA), water-soluble at any pH; and (3) humin, insoluble at any pH. The IHSS method involves contact of soil with 0.1N.NaOH solution, followed by acidification with HCl.

In this study, 0.01 N. …

Surface Modification Of Diamond And Determination Of Kinetics And Mechanism Of Modification Reactions, Humera Farooq

Masters Theses

A series of photochemically modified diamond surfaces were prepared. Surface functional groups added included, chlorine, bromine, methoxy, amine, methylamine, dimethylarnine and trimethylammonium chloride. Photochemically chlorinated and brominated diamond surfaces were used as synthetic intermediates. The modified diamond surfaces were characterized by Diffuse Reflectance Infrared Spectroscopy (DRIFT) and X-ray Photoelectron Spectroscopy (XPS).

The study was mainly focused on understanding the kinetic processes and reaction mechanism of modified surfaces. The observed rate constants for surface hydrogen loss and HCl (g) evolution were found to be identical. Similar rate constants were observed for amine substitution and consumption of ammonia.

The study of action …

Apoptosis Following Peripheral Sensory Deafferentation In The Olfactory Blub Of Adult Zebrafish, Danio Rerio, Akiko M. Vankirk

Masters Theses

Removal of the olfactory organ in the adult zebrafish results in a significant decrease in volume of the ipsilateral olfactory bulb. Our lab has been investigating the potential role of apoptosis in this phenomenon. My hypothesis is that cells in the adult olfactory bulb normally undergo minimal apoptosis and that apoptosis will increase when sensory stimulation is removed. The TUNEL method allowed detection of cells undergoing DNA-fragmentation, which indicates an apoptotic response. Double-label immunohistochemistry was used to mark which apoptotic cells are neurons by using antibody to Hu, a neuron specific protein. Triple-labeling with bis-benzirnide confirmed the apoptotic nature of …

The Geochemistry Of A Leaf Composting Leachate Plume, Asylum Lake, Kalamazoo, Michigan, Eric G. Steeves

Masters Theses

Since the implementation of legislation that bans yard waste from landfills, there has been a need to characterize the impact that large scale composting has on groundwater quality. Allen (1993) and Weaver (1995) have attempted to characterize a leaf composting leachate plume located at the WMU-Asylum Lake Well Field #2 in Kalamazoo, Michigan. Allen was not able to base any conclusions on geochemical results and Weaver delineated the plume using fewer monitoring wells than are now available.

The data from twenty-one monitoring wells indicates that local groundwater is being impacted by the large-scale composting operation. The plume is characterized by …

In Situ Biosurfactant Production At Carson City Park, Michigan, Andrew J. Hudak

Masters Theses

Crude oil refining operations conducted by the Crystal Refining Company in Carson City, Michigan have led to the contamination of the soil and groundwater at Carson City Park with petroleum hydrocarbons. In situ biosurfactant production, occurring as a result of the biodegradation activities of hydrocarbon degrading microorganisms, was investigated.

Background hydrogeological and biogeochemical data were collected from the groundwater from thirteen monitoring wells at Carson City Park. Further analysis included the identification of biosurfactant producing microorganisms and biosurfactants present in the soil and groundwater.

Results showed that Pseudomonas aeruginosa was producing both monorhamnolipids and dirhamnolipids (glycolipid biosurfactants) in the contaminated …

Subaerial Paleokarst In The Upper Pennington Formation (Upper Mississippian) Limestones At Leatherwood Ford, Big South Fork, Tennessee, Sara Elizabeth Humbert

Masters Theses

The uppermost Pennington Formation (Mississippian - latest Chesterian) consists of limestone deposits, which, in some areas, contain evidence of paleokarst. A 100 m long continuous outcrop of the upper Pennington Formation was studied at Big South Fork National River and Recreation Area, in Scott County, Tennessee, using both field and petrographic methods, in order to test the hypothesis that the paleokarst is of subaerial origin.

The upper Pennington limestone section was subdivided into 4 depositional units, interpreted as recording sea-level change through the end of the Mississippian. Although there was an overall regression toward the end of the Mississippian, changes …

An Investigation Of Friedel-Crafts Alkylation Reactions In Super- And Subcritical Carbon Dioxide And Under Solventless Reaction Conditions, Kan Nie

Masters Theses

This study investigates the Friedel-Crafts alkylation reaction of triphenylmethanol with methoxybenzene (anisole) in supercritical and subcritical carbon dioxide, and under solventless reaction conditions. The reaction was initiated using trifluoroacetic acid to produce triphenylmethylcarbocation as the reaction intermediate. Isolated product yields of the Friedel-Crafts product, p-methoxytetraphenylmethane, are reported. The possibility of using the above reaction as an alternative synthesis in an undergraduate organic laboratory to teach some of the tenets of green chemistry is also presented. Additionally, we have investigated the use of benzhydrol, 9-hydroxyxanthene and 9-phenylxanthen-9- ol as potential carbocation sources for supercritical carbon dioxide synthesis and we report those …

Computational Studies Of Regularities In Bond Dissociation Enthalpies And Interactions Of Acetylthiocholine With Solvent Molecules, Wencui Zheng

Masters Theses

This thesis reports the results of two different research projects. One project is an evaluation of the feasibility of applying constant bond dissociation enthalpy ratios to neutral molecules for which one atom is from group 13 or group 17 and the other atom is from group 16. The other project attempts to validate the proposal that the aromatic residues lining the acetylcholinesterase (AChE) gorge will induce entry of acetylthiocholine (ATCh) into the gorge in a manner similar to that of the neural transmitter acetylcholine.

A total of thirty AB₂ and AB molecules have been examined, where A = B, …

The Synthesis Of 2-Indenylphenols: Potential Ligands For Transition Metals, Yoon Jae Kim

Masters Theses

The syntheses of 2-(2-indenyl)-phenol and 2-(1-indenyl)-phenol via a three-step sequence have been developed. In the first steps of the sequence, a Grignard reagent formed from 2-iodoanisole or 2-bromoanisole reacted with 1-indanone or 2-indanone in yields that ranged from 11.3% to 67.2%. The second step consisted of acid-catalyzed dehydration of the alcohol formed in step 1 to make a 2-inenyl anisole; yields in the second step were 45.2% to nearly quantitative. Finally, demethylation of the 2-indenyl anisole was achieved with AlBr₃ in ethanethiol in yields ranging from 52.9% to 0 %. Each product was characterized by ¹H and ^{13 …}

The Reactivity Of Boron And Aluminum Compounds With Silica Gel Surfaces, Jeannine M. Christensen

Masters Theses

The unmodified silica gel surface contains isolated silanols, vicinal silanols, and siloxane species. Silica gels can be thermally and/or chemically treated to obtain a desired surface. Hexamethyldisilazane (HMDS) was used to chemically modify the silica gel to obtain a surface that contains vicinal silanol groups and siloxane species. The silica gel was thermally treated at 600°C to create a surface that contains isolated silanols and siloxane species. Four types of silica gels (unmodified, 600°C, HMDS and 600°C/HMDS) were reacted with three boron compounds. The boron compounds used were boron trichloride (BCl₃), triethyl borane (B(CH₂CH₃) …

Computational Studies Of Constant Bond Dissociation Enthalpy Ratios And Novel Structures For [H3, B, C, F]+, Le Li

Masters Theses

This thesis describes two separate computational chemistry projects. The first project is a study of constant bond dissociation enthalpy ratios, and the second project is a study of the rearrangement and fragmentation processes on the singlet potential energy surface of the [H₃, B, C, F]⁺ system.

G2 and G2(MP2) enthalpies have been calculated for isoelectronic AB₂ systems with singlet-linear, singlet-nonlinear, triplet-linear, and triplet-nonlinear electronic states and geometries, and for isoelectronic AB systems with singlet and triplet electronic states. For these systems, A = B^-, Al^-, Ga^-, C, Si, Ge, N …

Linkage Isomers Of Tungsten Carbonyl Complexes Of Ph₂Pch₂Pphch₂Pph₂, Chaminda P. Gamage

Masters Theses

The linkage isomers (CO)₅W[η¹-PPh₂CH₂PPhCH₂PPh₂], 1, and (CO)₅ W[η¹-PPh(CH₂PPh₂)₂], 2, have been synthesized from the reaction of (OC)₅W(NH₂Ph) and Ph₂PCH₂PPhCH₂PPh₂. In addition, linkage isomers (CO)₅W[μ-PPh₂CH₂PPhCH₂PPh₂]-W(CO)₅, 3, and (CO)₅W{μ-PPh₂CH₂PPh[W(CO)₅] CH₂PPh₂}, 4, have been prepared. Attempts to obtain (OC)₅WPPh₂CH …

A Ring-Closing Strategy For The Synthesis Of Β,Γ-Unsaturated Δ-Lactones, Erbing Hua

Masters Theses

Spiro β,γ-unsaturated δ-lactones and fused β,γ-unsaturated δ-lactones are integral to a large number of naturally occurring compounds exhibiting a diverse range of biological activity. A new synthetic route to β,γ-unsaturated δ-lactones, consisting of a three-step sequence, has been investigated for the synthesis of these kinds of pharmacological intermediates. Ring closure of a β-hydroxy acid by dehydration, providing a 4-vinyl substituted β-lactone, and its ring expansion/rearrangement are the two key steps in this protocol. The results have proved that this new method is efficient and quite expeditious. One spiro and four fused β,γ-unsaturated δ-lactones were synthesized through this protocol albeit in …

Pentacarbonyl Derivatives Of Polydentate Phosphines, Yi Zang

Masters Theses

Four phosphines (Ph₂P)₂C=CHPPh₂, (p-tol)₂PCH₂P(p-tol)₂, (o-tol)₂PCH₂P(o-tol)₂, Ph₂PCH₂P(p-tol)₂ and their pentacarbonyltungsten complexes have been prepared and studied as part of a continuous investigation of polydentate phosphines that are coordinated as monodentate ligands. The ligand, (Ph₂P)₂C=CHPPh₂, was prepared by base-catalyzed addition of Ph₂PH to Ph₂PC=CPPh₂. Reaction of this ligand with (OC)₅WNH₂Ph led to formation …

Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado

Masters Theses

The World Wide Web has become a very popular marketing medium during the recent years. Many businesses use it extensively to publicize their products. Initially it began with static web sites. However as web sites got bigger and better, their maintenance became problematic. Just as business strategies change, so also will the orgainization of their web sites change. Hence the need of the hour is an adaptive web site (i.e. a web site that can organize itself based upon its usage). For this purpose, web usage mining techniques are used. The characteristics of the user's activity on the web site …

Constraining The Crystallization And Post-Crystallization History Of The Wallamatogus Pluton, Maine, Using Compositional Data From Garnet, Biotite And Muscovite, Joy Kathleen Drake

Masters Theses

"The Wallamatogus Pluton, Maine, exhibits systematic variation in grain size, mineralogy, and phenocryst abundance (alkali-feldspar) from the margin to the center of the pluton. Three facies are recognized: 1) outermost, seriate, coarse-grained (Owe), 2) porphyritic medium- to fine-grained (Dwp ), 3) innermost, fine-grained equigranular (Dwf). These facies are concentrically arranged and their contacts are gradational. Muscovite and biotite occur in all facies; the outer two facies contain garnet, and tourmaline. Muscovite and biotite grains within micaceous enclaves compositionally overlap primary muscovite, suggesting that they are early-crystallized accumulations. Muscovite in multiphase clusters and secondary muscovite compositionally overlap, suggesting formation during post-crystallization …