Thesis (M.A.)--Boston University, 1929. This item was digitized by the Internet Archive.

abstract: The fuel cell is a promising device that converts the chemical energy directly into the electrical energy without combustion process. However, the slow reaction rate of the oxygen reduction reaction (ORR) necessitates the development of cathode catalysts for low-temperature fuel cells. After a thorough literature review in Chapter 1, the thesis is divided into three parts as given below in Chapters 2-4. Chapter 2 describes the study on the Pt and Pt-Me (Me: Co, Ni) alloy nanoparticles supported on the pyrolyzed zeolitic imidazolate framework (ZIF) towards ORR. The Co-ZIF and NiCo-ZIF were synthesized by the solvothermal method and then mixed with Pt precursor. After pyrolysis and acid leaching, the PtCo/NC and PtNiCo/NC were evaluated in proton exchange membrane fuel cells (PEMFC). The peak power density exhibited > 10% and 15% for PtCo/NC and PtNiCo/NC, respectively, compared to that with commercial Pt/C catalyst under identical test conditions. Chapter 3 is the investigation of the oxygen vacancy (OV) effect in a-MnO2 as a cathode catalyst for alkaline membrane fuel cells (AMFC). The a-MnO2 nanorods were synthesized by hydrothermal method and heated at 300, 400 and 500 ℃ in the air to introduce the OV. The 400 ℃ treated material showed the best ORR performance among all other samples due to more OV in pure a-MnO2 phase. The optimized AMFC electrode showed ~ 45 mW.cm-2, which was slightly lower than that with commercial Pt/C (~60 mW.cm-2). Chapter 4 is the density functional theory (DFT) study of the protonation effect and active sites towards ORR on a-MnO2 (211) plane. The theoretically optimized oxygen adsorption and hydroxyl ion desorption energies were ~ 1.55-1.95 eV and ~ 0.98-1.45 eV, respectively, by Nørskov et al.’s calculations. All the configurations showed oxygen adsorption and hydroxyl ion desorption energies were ranging from 0.27 to 1.76 eV and 1.59 to 15.0 eV, respectively. The site which was close to two Mn ions showed the best oxygen adsorption and hydroxyl ion desorption energies improvement with the surface protonation. Based on the results given in Chapters 1-4, the major findings are summarized in Chapter 5. / Dissertation/Thesis / Doctoral Dissertation Systems Engineering 2019

Harry Partch's tuning system is an important contribution to tuning theory, and his music is original and significant. Part One of this study presents a brief biography of Partch, a discussion of his musical aesthetics (Monophony and Corporeality), and a technical summary of his tuning system. These elements are placed in historical perspective. Part Two presents a comprehensive analysis of "And on the Seventh Day Petals Fell on Petaluma," discussing the organization of formal, textural, rhythmic, linear, and tonal elements in the thirty-four "verses" of the work. Part Two concludes by showing how large-scale structure in the work is achieved through an overlay process.

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This essay analyses how social interactions influence Rachel’s racial identity development using social psychology as the theoretical approach. It also discusses how a main part of racial identity development, racial identity invalidation, which is proven to cause chronic mental health issues in multiracial individuals, is what allows Rachel to explore her black ancestry and culture.

Understanding how the Renaissance rhetorical curriculum taught style as behavior makes it possible to unite the study of women writers' identities with formal criticism. Nancy L. Christiansen shows that early modern humanists built on the Isocratean tradition of teaching rhetoric as an ethical practice because they adopted and developed lists of rhetorical figures so extensive as to encompass all human discourse, thought, and behavior. For them, knowing, selecting, and applying these various forms was the ethical practice of good judgment, also called decorum. This type of decorum plays an important role in the rhetorical function of two key texts by early modern women. Margaret Fell and Aemilia Lanyer each use a humanist notion of decorum as the virtue of good judgment to formulate their intellectual and moral authority and to argue that women can exercise the same.