Description: Minimum quantity lubrication replaces the traditional method of flood cooling with small amounts of high-efficient lubrication. Limited studies have been performed to determine the characteristics of mist produced during MQL. This study investigated the mist concentration levels produced while drilling 1018 steel using a vegetable based lubricant. ANOVA was performed to determine whether speed and feed rates or their interactions have a significant effect on mist concentration levels and particle diameter. It was observed that the concentration levels obtained under all four speed and feed rate combinations studied exceeded the current OSHA and NIOSH standards.

Description: Rare earth ion doped glasses find applications in optical and photonic devices such as optical windows, laser, and optical amplifiers, and as model systems for immobilization of nuclear waste. Macroscopic properties of these materials, such as luminescence efficiency and phase stability, depend strongly on the atomic structure of these glasses. In this thesis, I have studied the atomic level structure of rare earth doped silicate and aluminophosphate glasses by using molecular dynamics simulations. Extensive comparisons with experimental diffraction and NMR data were made to validate the structure models. Insights on the local environments of rare earth ions and their clustering behaviors and their dependence on glass compositions have been obtained. In this thesis, MD simulations have been used to investigate the structure of Eu2O3-doped silica and sodium silicate glasses to understand the glass composition effect on the rare earth ions local environment and their clustering behaviors in the glass matrix, for compositions with low rare earth oxide concentration (~1mol%). It was found that Eu–O distances and coordination numbers were different in silica (2.19-2.22 Å and 4.6-4.8) from those in sodium silicate (2.32 Å and 5.8). High tendencies of Eu clustering and short Eu-Eu distances in the range 3.40-3.90 Å were ...

Description: This narrative study explores how two Taiwanese college art teachers’ lives and teaching experiences illustrate the ways they cultivate resilience and motivation to sustain professional commitments amidst challenges in their teaching careers. I use the life story interview as my methodology and a three-dimensional space approach to code and analyze my data to retell their stories about how resilience and motivation have guided them as they negotiated dilemmas in teaching. The participants’ stories demonstrate that in order to be motivated, teachers must satisfy their basic needs, which, in the language of Maslow’s need theory, include secure income, safety, love and belonging, respect, and personal accomplishment. To be resilient, art teachers need to facilitate self-efficacy as an essential belief to face challenges, and they also must gain support from family members, students, school administrators, and fellow members of professional organizations as external support resources. This study also illuminates the significance of international educational exchanges, the teaching knowledge constructed through layers of life and professional experience, and the importance of creating dialogue to address teachers’ challenges. Recommendations for future study include exploring further the relationship between motivation and resilience, specifying how gender difference affects the ways participants tell their stories, investigating how ...

Description: In 1619, Johannes Kepler published his magnum opus Harmonices mundi in which the astronomer derived distinct pitches and scales for each known planet in the solar system from calculations of various aspects of their orbital motions. This was the first theoretical realization of the ancient tradition of musica universalis (also called musica mundana), or music of the celestial bodies. It was not until the Estonian composer Urmas Sisask (b. 1960) began his compositional career by deriving his own “planetary scale,” however, that the theoretical musica universalis came into audible existence. Sisask’s work represents a distinctive musical voice among today’s choral composers, and although he is steadily gaining attention for his unique compositional style, only limited information exists about the specifics of his background, his interest in astronomy and shamanism, and the subsequent influence these interests have had on his choral music. At once traditional and modern, he bridges the gap between ancient Estonian folk song and the present. Through an application of exotic techniques including extreme repetition, ritualistically driving rhythms and sudden changes in timbre and texture; coupled with his own peculiarly crafted “planetary scale,” Urmas Sisask has created a completely unique body of work which is examined in this ...

Description: Many processes and systems in nature and society can be characterized as large numbers of discrete elements that are (usually non-uniformly) interrelated. These networks were long thought to be random, but in the late 1990s, Barabási and Albert found that an underlying structure did in fact exist in many natural and technological networks that are now referred to as scale free. Since then, researchers have gained a much deeper understanding of this particular form of complexity, largely by combining graph theory, statistical physics, and advances in computing technology. This dissertation focuses on out-of-equilibrium dynamic processes as they unfold on these complex networks. Diffusion in networks of non-interacting nodes is shown to be temporally complex, while equilibrium is represented by a stable state with Poissonian fluctuations. Scale free networks achieve equilibrium very quickly compared to regular networks, and the most efficient are those with the lowest inverse power law exponent. Temporally complex diffusion also occurs in networks with interacting nodes under a cooperative decision-making model. At a critical value of the cooperation parameter, the most efficient scale free network achieves consensus almost as quickly as the equivalent all-to-all network. This finding suggests that the ubiquity of scale free networks in nature ...