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UNT Theses and Dissertations
Impact of Texas High School Science Teacher Credentials on Student Performance in High School Science
Date: August 2012
Creator: George, Anna Ray Bayless
Description: A study was conducted to determine the relationship between the credentials held by science teachers who taught at a school that administered the Science Texas Assessment on Knowledge and Skills (Science TAKS), the state standardized exam in science, at grade 11 and student performance on a state standardized exam in science administered in grade 11. Years of teaching experience, teacher certification type(s), highest degree level held, teacher and school demographic information, and the percentage of students who met the passing standard on the Science TAKS were obtained through a public records request to the Texas Education Agency (TEA) and the State Board for Educator Certification (SBEC). Analysis was performed through the use of canonical correlation analysis and multiple linear regression analysis. The results of the multiple linear regression analysis indicate that a larger percentage of students met the passing standard on the Science TAKS state attended schools in which a large portion of the high school science teachers held post baccalaureate degrees, elementary and physical science certifications, and had 11-20 years of teaching experience.
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc149592/
Synthesis and Characterization of Two and Three Coordinate Gold (I) Conjugated and Rigid Metallodendrimers
Date: August 2012
Creator: Kaipa, Ushasree
Description: This dissertation is a study of two major topics that involve synthetic strategies for new classes of phosphorescent gold(I)-based metallodendrimers. The phosphorescence of organic and inorganic luminophores originates from spin-orbit coupling owing to internal or external heavy atom effects as well as metal-centered emissions. Previous work in the Omary group entailed systematically designed small molecules, metallopolymers, and unconjugated metallodendrimers that contain d10 and d8 metals, whereas this dissertation aims in part to expand such strategies to the conjugated metallodendrimer regime. In one approach novel synthetic strategies were used to make first-generation phenyl acetylene dendrimers and phosphine derivatives thereof. The phosphine dendrimers are made by tethering one of the phosphines to an unsaturated dendrimer, as such phosphine dendrimers are better chromophores and luminophores due to their structural rigidity and extended conjugation. In another approach, 2- and 3-coordinate Au(I) dendritic complexes are synthesized from these phosphine dendrimers. This study is further extended to study metallodendritic complexes with different cores, for example triphenylene-based metallodendritic complexes with six acetylene branches. The physical properties of the metallodendrimers can be modulated upon proceeding to further dendrimer generations or by using solubilizing groups on the peripheral phosphines, thus allowing better processability for thin-film fabrication as required for ...
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Permallink:digital.library.unt.edu/ark:/67531/metadc149678/
Supramolecular Solar Cells
Date: August 2012
Creator: Subbaiyan, Navaneetha Krishnan
Description: Supramolecular chemistry - chemistry of non-covalent bonds including different type of intermolecular interactions viz., ion-pairing, ion-dipole, dipole-dipole, hydrogen bonding, cation-p and Van der Waals forces. Applications based on supramolecular concepts for developing catalysts, molecular wires, rectifiers, photochemical sensors have been evolved during recent years. Mimicking natural photosynthesis to build energy harvesting devices has become important for generating energy and solar fuels that could be stored for future use. In this dissertation, supramolecular chemistry is being explored for creating light energy harvesting devices. Photosensitization of semiconductor metal oxide nanoparticles, such as titanium dioxide (TiO2) and tin oxide (SnO2,), via host-guest binding approach has been explored. In the first part, self-assembly of different porphyrin macrocyclic compounds on TiO2 layer using axial coordination approach is explored. Supramolecular dye sensitized solar cells built based on this approach exhibited Incident Photon Conversion Efficiency (IPCE) of 36% for a porphyrin-ferrocene dyad. In the second part, surface modification of SnO2 with water soluble porphyrins and phthalocyanine resulted in successful self-assembly of dimers on SnO2 surface. IPCE more than 50% from 400 - 700 nm is achieved for the supramolecular self-assembled heterodimer photocells is achieved. In summary, the axial ligation and ion-pairing method used as supramolecular tools to ...
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Permallink:digital.library.unt.edu/ark:/67531/metadc149672/
Nitrogen Derivatives of Naphthoquinone
Date: August 1952
Creator: Hall, Robert L.
Description: This thesis investigates nitrogen derivatives of naphthoquinone.
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Permallink:digital.library.unt.edu/ark:/67531/metadc130278/
Hydantoins as Anticonvulsants. V. 5-Substituted-Amino Derivatives of 5-Phenylhydantoin
Date: August 1950
Creator: Jeanes, Dewey Perry
Description: This thesis describes the preparation of 5-substituted-amino derivatives of 5-phenylhydantoin. The hydantoin derivatives are to be tested for anticonvulsant activity by the Pharmacology Department of the Eli Lilly Company of Indianapolis, Indiana.
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc130245/
Amine Derivatives of 3-chloro-5(8?)-nitro-1,4-naphthoquinone
Date: August 1952
Creator: Whitaker, Leroy, 1929-
Description: This work deals with the preparation of amine derivatives of 3-chloro-5(8?)-nitro-1,4-naphthoquinone which are to be tested for anti-tubercular activity by Parke, Davis and Company.
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc130300/
The Photochemical Reactions of 2,7-dimethyloctane
Date: June 1953
Creator: Trammell, Margaret Ruth
Description: This thesis is a study of the photochemical reactions of 2,7-dimethyloctane.
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Permallink:digital.library.unt.edu/ark:/67531/metadc130312/
Nitrogen Derivatives of Naphthoquinone
Date: June 1953
Creator: Wood, Frank M.
Description: A series of nitrogen derivatives of 1,4-naphthoquinone, which are structurally similar to the compounds of Hall, has been prepared by this worker. In general, the amido groups are those of the long-chain, fatty acids, and it is believed they will have increased physiological activity. These compounds are to be tested for medicinal activity by Parke-Davis and Company.
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Permallink:digital.library.unt.edu/ark:/67531/metadc130314/
The Adsorption of Radioactive Isotopes on Specific Precipitates
Date: August 1954
Creator: Yarbrough, Kenneth N.
Description: The purpose of this investigation is to reveal the effects of certain factors affecting adsorption on some specific precipitates. It is hoped that the choice of precipitate types will enable extension of the information gained here to other precipitates similar to those investigated.
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc130408/
The Adsorption of Radioactive Isotopes on Precipitates
Date: January 1954
Creator: Bulloch, Newman Payne
Description: This thesis concerns the investigation of radioisotopes as indicators for precipitation reactions. As a precipitate forms in the presence of a radioisotope, adsorption may take place on its surface. If this adsorption changes markedly at the stoichiometric point it will be possible to use this variation as an indicator for the reaction.
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc130352/