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 Collection: UNT Theses and Dissertations
A preliminary study on the effect of selective serotonin reuptake inhibitors on peripheral and lower brainstem auditory processing.

A preliminary study on the effect of selective serotonin reuptake inhibitors on peripheral and lower brainstem auditory processing.

Access: Use of this item is restricted to the UNT Community.
Date: May 2001
Creator: Carney, Lara E.
Description: This study compared auditory behavioral and physiologic measures in normal control subjects and subjects prescribed with a selective serotonin reuptake inhibitor (SSRI) who were yet to take the drug and those currently taking an SSRI. Test measures used were pure tone averages (PTA), acoustic reflex thresholds, uncomfortable loudness levels (UCL), otoacoustic emissions, masking level difference, temporal integration, amplitude resolution, and Beck Depression Inventory-II (BDI-II) scores. Results indicated that there was a significant difference in the amplitude resolution of the unmedicated group when compared to the medicated and the control group. There was also a significant positive correlation between dynamic range (difference between UCL and PTA) and amplitude resolution. The BDI-II revealed a significant difference between the scores of the unmedicated and the control group as well as the medicated and the control group. Although other test measures indicated differences between the groups, the differences were not statistically significant.
Contributing Partner: UNT Libraries
Preparation and Characterization of a Treated Montmorillonite Clay and Epoxy Nanocomposite

Preparation and Characterization of a Treated Montmorillonite Clay and Epoxy Nanocomposite

Date: December 2000
Creator: Butzloff, Peter Robert
Description: Montmorillonite reinforced polymers are a new development in the area of nanocomposite materials. Since reinforcement of epoxy is important to the development of high strength adhesives and composite matrices, the introduction of montmorillonite to epoxy is of interest. Compositional effects on epoxy reactivity, on molecular relaxation, and on mechanical properties were investigated. Change in reactivity was determined by Differential Scanning Calorimetry. Tensile properties at room temperature indicated improved modulus and retention of strength of the epoxy matrix but a decreased elongation to failure. Depression of dry nanocomposite glass transition was observed for nanocomposites beyond 5% by weight montmorillonite. Samples that were saturated with water showed lower moduli due to the epoxy matrix. The greatest moisture absorption rate was found at 7%, the least at 3%.
Contributing Partner: UNT Libraries
Preparation and characterization of praseodymium oxide films and powders.

Preparation and characterization of praseodymium oxide films and powders.

Access: Use of this item is restricted to the UNT Community.
Date: May 2004
Creator: Shang, Yajuan
Description: Nanocrystalline praseodymium oxide films have been successfully generated on stainless steel substrates. The electrochemical deposition was performed in the cathode compartment of a divided electrochemical cell with a regular three-electrode configuration. The green films obtained by electrodeposition were then annealed at high temperatures for 1-3 hours. X-ray diffraction revealed the fluorite structure of Pr6O11 and the crystallite size was calculated. X-ray photoelectron spectroscopy was employed to study the composition of the oxide films and also the oxidation state of Pr. Scanning electron microscopy was utilized to study the surface texture and microstructure of deposits. Fourier transform infrared spectrometery was used to investigate the composition of the films. The effects of different conditions on the green films were also studied such as different pH values of the electrolyte solution, different deposition modes, different supporting electrolytes and different applied current densities. Sintering experiments were conducted to investigate the properties of the green films. Praseodymium oxide powders were also successfully prepared by combining electrochemical methods with sintering processes. The praseodymium oxide powders were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The crystallite sizes of the powders were evaluated.
Contributing Partner: UNT Libraries
The preparation and characterization of thermo-sensitive colored hydrogel film and surfactant-free porous polystyrene three-dimensional network.

The preparation and characterization of thermo-sensitive colored hydrogel film and surfactant-free porous polystyrene three-dimensional network.

Date: December 2001
Creator: Zhou, Bo
Description: Polymer hydrogel films change their properties in response to environmental change. This remarkable phenomenon results in many potential applications of polymer hydrogel films. In this thesis colored thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogel film was prepared by firstly synthesizing polymer latex and secondarily crosslinking the nanoparticles and casting the polymers onto glass. The shape-memory effect has been observed when changing the environmental temperature. The temperature-dependent of turbidity of polymer hydrogel film was measured by HP UVVisible spectrophotometer. This intelligent hydrogel might be used in chemomechanical systems and separation devices as well as sensors. Polymer adsorption plays an important role in many products and processes. In this thesis, surfactant-free three-dimensional polystyrene (PS) nanoparticle network has been prepared. The infrared spectroscopy and solubility experiment are performed to prove the crosslinking mechanism, also the BET method was used to measure the adsorption and desorption of polystyrene network. The BET constant (C) is calculated (C=6.32). The chemically bonded polymer nanoparticle network might have potential applications as catalyst or used for chromatographic columns.
Contributing Partner: UNT Libraries
Preparation of 4-Amino-3-Hydrazino-5-Methyl-s-Triazole Dihydrochloride and Condensation Products

Preparation of 4-Amino-3-Hydrazino-5-Methyl-s-Triazole Dihydrochloride and Condensation Products

Date: August 1965
Creator: Westmoreland, Thomas D.
Description: The procedure of Takimoto, Denault, and Hotta was followed in order to prepare 4-amino-3-hydrazino-5-methyl-s-triazole hydrochloride (II) and its precursor, triamino-guanidine hydrochloride (I).
Contributing Partner: UNT Libraries
The Preparation of Academic Library Administrators

The Preparation of Academic Library Administrators

Date: December 2012
Creator: Hoffman, Starr
Description: The purpose of this quantitative study was to determine the preparation methods experienced by academic library deans and which methods they perceived to be most valuable. Rosser, Johnsrud, and Heck (2000, 2003) defined the theoretical constructs of effective academic leadership upon which this study is based. The instrument—a modified version of Greicar's (2009) Professional Preparation of Academic Deans Questionnaire—was administered online. The population was the chief administrators of academic libraries in the United States; there were 749 usable responses for a 30.4% response rate. Respondents were primarily female (61.7%), White non-Hispanic (90.0%), and born in the United States (95.7%), with a mean age of 56.4 (5.9% < 40, 11.0% > 65). The largest minority group was Black, non-Hispanic (3.9%). Many respondents held multiple advanced degrees; 90.0% held an MLS, 45.8% held a subject master's, and 18.8% held a doctorate. The instrument measured academic library deans' perceived value of various preparatory methods (formal and informal mentoring, on the job training, conferences or seminars, advanced degrees beyond the MLS, and training programs). The methods were tested for perceived effectiveness with Rosser, Johnsrud, and Heck's (2000, 2003) theoretical constructs of academic leadership. Each preparation method was measured using eight item-level variables and summed ...
Contributing Partner: UNT Libraries
Preparation of Alkoxy Derivatives of 2-Chloro-1,4-Naphthoquinone and 2-Chloro-5(8?)- Nitro-1,4-Naphthoquinone

Preparation of Alkoxy Derivatives of 2-Chloro-1,4-Naphthoquinone and 2-Chloro-5(8?)- Nitro-1,4-Naphthoquinone

Date: June 1962
Creator: Hern, Kenneth T.
Description: This paper studies the the synthesis of certain alkoxy compounds of 2,3-dichloro-1,4-naphthoquinone that can be considered chemotherapeutic agents.
Contributing Partner: UNT Libraries
Preparation of flat dendrimers and polycyclic aromatic hydrocarbons connected via 1,3,5-triethynylbenzene core.

Preparation of flat dendrimers and polycyclic aromatic hydrocarbons connected via 1,3,5-triethynylbenzene core.

Date: December 2008
Creator: Jung, Jiyoung
Description: Flat dendrimers, consisting of a hexavalent aromatic core and rigid ethynyl units locked in place by ether connections were developed based upon the divergent synthetic method. Alternating functional groups were adopted on each site of the hexa-substituted benzene, in order to avoid undesired cyclization pathways. The flat structures of conjugated dendrimers would allow investigation on the discotic liquid crystal properties. In addition, these ethylnyl dendrimers are expected to show directed energy and electron transfer with a highly conjugated system, and thus are effective in the preparation of photoreactive materials such as electronic sensors or light harvesting materials. Conjugated polycyclic aromatic hydrocarbons, consisting of naphthalene, anthracene, pyrene, and phenanthrene groups connected via 1,3,5-triethynylbenzene cores, were synthesized. These molecules exhibited luminescence properties and the π-complexation with a mercury trifunctional lewis acid are expected to enhance the phosphorescence in the presence of the heavy metal due to the spin-orbit coupling. Besides, owing to the presence of heavy metal atom in the Au (I) complexes linked by s-bonded triethynyltriphenylene luminophore, the phosphorescence occurs from a metal-centered emission. The conjugated organic luminophores have been developed to produce excellent quantum efficiencies, brightness, and long lifetimes.
Contributing Partner: UNT Libraries
Preparation of N-Substituted Hydroxylamines from Oxaziridines

Preparation of N-Substituted Hydroxylamines from Oxaziridines

Date: January 1968
Creator: Truitt, Sharon G.
Description: In many series of compounds, intensity of biological activity and chemical reactivity are proportional. Generally whenever a alkyl group replaces a reactive hydrogen atom, as would be the case for an N-substituted hydroxylamine as compared to hydroxylamine, the over-all biological activity of the resulting compound is lower than that of its nonalkylated analogue. Since toxicity and physiological activity are not proportional, this comparison can only suggest possible types of derivatives to prepare and test.
Contributing Partner: UNT Libraries
The Preparation of Pyridinium Derivatives by the Knoevenagel Condensation

The Preparation of Pyridinium Derivatives by the Knoevenagel Condensation

Date: May 1955
Creator: Miller, Eugene James
Description: An attempt is made in the work described in this paper to extend the series started by Hall and Platas by means of a Knoevenagel condensation between 3-hydroxy-1,4-naphtho-quinone-2-(4-methylpyridinium) anhydride and various aromatic aldehydes giving rise to a series of unsaturated substituents on the four position of the pyridine ring.
Contributing Partner: UNT Libraries