2012 Dissertations (UMKC)
https://hdl.handle.net/10355/13615
The items in this collection are the scholarly output of UMKC graduate students.2024-03-19T05:26:16ZAb initio calculations of mechanical, thermodynamic and electronic structure properties of mullite, Iota-alumina and boron carbide
https://hdl.handle.net/10355/14307
Ab initio calculations of mechanical, thermodynamic and electronic structure properties of mullite, Iota-alumina and boron carbide
Aryal, Sita Ram
The alumino-silicate solid solution series (Al₄₊₂xSi₂-2xO₁₀-x) is an important class of ceramics. Except for the end member (x=0), Al₂SiO₅ the crystal structures of the other phases, called mullite, have partially occupied sites. Stoichiometric supercell models for the four mullite phases 3Al₂O₃ • 2SiO₂, 2Al₂O₃ • SiO₂ , 4Al₂O₃ • SiO₂ , 9Al₂O₃ • SiO₂ , and ι-Al₂O₃ (iota-alumina) are constructed starting from experimentally reported crystal structures. A large number of models were built for each phase and relaxed using the Vienna ab initio simulation package (VASP) program. The model with the lowest total energy for a given x was chosen as the representative structure for that phase. Electronic structure and mechanical properties of mullite phases were studied via first-principles calculations. Of the various phases of transition alumina, ι-Al₂O₃ is the least well known. In addition structural details have not, until now, been available. It is the end member of the aluminosilicate solid solution series with x=1. Based on a high alumina content mullite phase, a structural model for ι-Al₂O₃ is constructed. The simulated x-ray diffraction (XRD) pattern of this model agrees well with a measured XRD pattern. The ι-Al₂O₃ is a highly disordered ultra-low-density phase of alumina with a theoretical density of 2854kg=m3 . Using this theoretically constructed model, elastic, thermodynamic, electronic, and spectroscopic properties of ι-Al₂O₃ have been calculated and compared it with those of α-Al₂O₃ and γ-Al₂O₃. Boron carbide (B₄C) undergoes an amorphization under high velocity impacts. The mechanism of amorphization is not clear. Ab initio methods are used to carry out largescale uniaxial compression simulations on two polytypes of stoichiometric boron carbide (B₄C), B₁₁C-CBC, and B₁₂-CCC where B₁₁C or B₁₂ is the 12-atom icosahedron and CBC or CCC is the three-atom chain. The simulations were performed on large supercells of 180 atoms. Simulated results indicate bending of the three-atom chain leads to the amorphization of the B₁₁C-CBC(B₁₂-CCC) at a uniaxial strain s=0.23 (0.22) and with a maximum stress of 168 (151) GPa. The mechanism of amorphization is analyzed with radial pair distribution function (RPDF), total density of states (TDOS), and the distribution of effective charges on atoms.
Title from PDF of title page, viewed on May 22, 2012; Dissertation advisor: Wai-Yim Ching; Vita; Includes bibliographic references (p. 143-157); Thesis (Ph.D.)--Dept. of Physics and Dept. of Geosciences. University of Missouri--Kansas City, 2012
2012-05-22T00:00:00ZAn analysis of factors affecting implementation of literacy curriculum resources in K-2 classrooms in a Midwest suburban school district
https://hdl.handle.net/10355/16252
An analysis of factors affecting implementation of literacy curriculum resources in K-2 classrooms in a Midwest suburban school district
Elder-Hurst, Karen
This study explored teacher perceptions through a triangulation of data from surveys, interviews, and document analysis to identify how literacy curriculum implementation is affected in Kindergarten through second grade classrooms. Research was based around three questions: How do K-2 teachers perceive their professional development of the new literacy curriculum? How do K-2 teachers perceive their implementation of the new literacy curriculum? How do K-2 teachers perceive leadership support for the implementation of the new literacy curriculum? The first step in the data collection process involved sending an electronic survey to all Kindergarten, grade one and grade two teachers meeting the criteria for inclusion in the study. Demographic profiles and open-ended questions were used to collect data along with the survey questions. Six teachers (two Kindergarten, two first grade and two second grade) were interviewed using a semi-structured protocol with each interviewee. Documents were collected and included professional development guides, training schedules, and curriculum resource literature. Results indicated implementation is hindered when professional development is vague and does not provide opportunity for participants to learn, practice, and collaborate together. Implementation in the classroom is enhanced when participants receive feedback and opportunities to observe others, ask questions, and know full implementation takes time. Implementation is enhanced when leadership is supportive and listens to the needs and concerns of the participants. Providing a culture allowing for mistakes and opportunities to improve helps participants feel excited and engaged in the new learning.
Title from PDF of title page, viewed on January 4, 2013; Dissertation advisor: Donna Davis; Vita; Includes bibliographic references (p. 149-166); Thesis (Ph.D.)--School of Education. University of Missouri--Kansas City, 2012
2012-01-01T00:00:00ZChild's Play:a Collection of Three Pieces for Instruments and Fixed Electronic Media
https://hdl.handle.net/10355/45113
Child's Play:a Collection of Three Pieces for Instruments and Fixed Electronic Media
Bolte, Jason Lee, 1985-
"Child's Play" is a collection of three pieces for instruments and fixed electronic media inspired by the sounds of my daughter's toys. The first piece, "With My Eyes Shut" is for clarinet and fixed electronic media, the second piece, "Noises Everywhere" is for fixed electronic media, and the final piece, "Child's Play" is scored for flute, clarinet, cello, piano, and fixed electronic media. "With My Eyes Shut" is an exploration of a single sound produced on a plastic recorder. All of the electronic material is derived from this single sound. The piece is centered on diatonic pitch relationships and incorporates the clarinet as a motivic vehicle to progress through the piece. "Noises Everywhere" is inspired by a snippet of text from the classic children's book "Goodnight Moon" by Margaret Wise Brown, a book my daughter and I love to read at bedtime. The foundation of the piece is a recording of a Fisher-Price "Happy Apple" toy. The toy has a unique resonance that provides the overall sonic timbre and pitch material of the piece. The final piece in the collection, "Child's Play," in contras to the other works in the collection, is a rhythmically driven work. The piece is inspired by rhythmic activity produced by a child's squeaky toy. This sound makes up all of the material in the fixed electronic medium. In the piece, the instruments and fixed electronic medium share the rhythmic responsibility, creating a regular, but often syncopated texture.
Title from PDF of title page, viewed on March 9, 2015; Thesis advisor: James Mobberley; Vita; Dissertation (Conservatory of Music and Dance) University of Missouri--Kansas City, 2012
2015-03-09T00:00:00ZConformational stability of some silanes and amines from temperature dependent Infrared spectra of rare as solutions, r₀ structural parameters, ab initio calculations, and vibrational assignments
https://hdl.handle.net/10355/14609
Conformational stability of some silanes and amines from temperature dependent Infrared spectra of rare as solutions, r₀ structural parameters, ab initio calculations, and vibrational assignments
Panikar, Savitha Subash
The infrared (3600-40 cm-1) and Raman (3600-20 cm-1) spectra of numerous molecules containing silanes or amines have been recorded in the gas, liquid and solid phases. Additionally, variable temperature studies of the infrared spectra of the sample dissolved in rare gases have been recorded. After identifying the conformer(s) from these spectral data, relatively complete vibrational assignments were proposed for these form(s). These vibrational assignments were supported by normal coordinate calculations with scaled force constants from MP2(full)/6-31G(d) calculations from which the fundamental vibrational frequencies, infrared intensities, Raman activities, depolarization values and infrared band contours were predicted. Barriers to internal rotation are also reported for some of the silane molecules. Potential functions governing conformational interchange were also determined, based on torsional transitions frequencies, conformational enthalpy differences and dihedral angles. For methylsilylcyclopropane, the enthalpy difference of the sample dissolved in xenon has been determined to be 98 ± 13 cm-1 (1.17 ± 0.16 kJ mol-1) with gauche the more stable conformer. For ethylenediamine, three of the possible ten conformers have been identified, and the enthalpy differences have been determined among the most stable g′G′g′ conformer and the second stable conformer, g′G′t, to be 64 ± 6 cm-1 (0.77 ± 0.07 kJ mol-1) and the third conformer, gG′g′, to be 210 ± 19 cm-1 (2.51 ± 0.23 kJ mol-1). For 2,2-difluoroethylamine, the enthalpy differences among the most stable Tt conformer and the second stable conformer, Gg, is 83 ± 8 cm-1 (0.99 ± 0.10 kJ mol-1), the third stable conformer, Gt, is 235 ± 11 cm-1 (2.81 ± 0.13 kJ mol-1). For pyrrolidine, the envelope-equatorial conformer is determined to be more stable by 109 ± 11 cm-1 (1.30 ± 0.13 kJ mol-1) than the than the twist form. By utilizing previously determined rotational constants from microwave studies combined with structural parameters predicted from MP2(full)/6-311+G(d,p) calculations, adjusted r0 structures have been obtained for conformers of the various molecules.
Title from PDF of title page, viewed on June 12, 2012; Dissertation advisor: James R. Durig; Vita; Includes bibliographical references (p. 384-399); Thesis (Ph.D.)--Dept. of Chemistry and Dept. of Geosciences. University of Missouri--Kansas City, 2012
2012-06-12T00:00:00Z