Matching Items (234)
Description
The ability of musicians to perform well in multiple musical styles is increasingly common and necessary. This paper profiles two trombonists who have gone well beyond the ability to function in multiple genres, and are instead considered significant artists. Tony Baker and Alex Iles were chosen to be profiled for this project because both have achieved recognition as solo artists in the genres of classical music and jazz and have performed on international stages as soloists. They also have significant ensemble experience in both classical and jazz settings and are active teachers as well. Both hold-high profile positions that have helped grow their reputations as performers: Mr. Baker as a professor at one of the largest music schools in the United States, the University of North Texas, and Mr. Iles as a highly in-demand freelance musician in Los Angeles. This paper presents interviews with both trombonists that investigate their development as musicians and soloists in both classical music and jazz. They are asked to describe the benefits and challenges of performing at a high level in both styles, and how these have affected their musical voices. Common traits found in their responses are examined, and recommendations are created for musicians seeking stylistic versatility.
ContributorsLennex, William (Author) / Pilafian, J. Samuel (Thesis advisor) / Bush, Jeffrey (Committee member) / Ericson, John (Committee member) / Hackbarth, Glenn (Committee member) / Holbrook, Amy (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this work, I worked on the synthesis and characterization of nanowires and belts, grown using different materials, in Chemical Vapor Deposition (CVD) system with catalytic growth method. Through this thesis, I utilized the Photoluminescence (PL), Secondary Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) analyses to find out the properties of Erbium Chloride Silicate (ECS) and two segment CdS-CdSe samples. In the first part of my research, growth of very new material, Erbium Chloride Silicate (ECS), in form of core/shell Si/ECS and pure ECS nanowires, was demonstrated. This new material has very fascinating properties for new Si based photonic devices. The Erbium density in those nanowires is which is very high value compared to the other Erbium doped materials. It was shown that the luminescence peaks of ECS nanowires are very sharp and stronger than their counterparts. Furthermore, both PL and XRD peaks get sharper and stronger as growth temperature increases and this shows that crystalline quality of ECS nanowires gets better with higher temperature. In the second part, I did a very detail research for growing two segment axial nanowires or radial belts and report that the structure type mostly depends on the growth temperature. Since our final step is to create white light LEDs using single axial nanowires which have three different regions grown with distinct materials and give red, green and blue colors simultaneously, we worked on growing CdS-CdSe nanowires or belts for the first step of our aim. Those products were successfully grown and they gave two luminescence peaks with maximum 160 nm wavelength separation depending on the growth conditions. It was observed that products become more likely belt once the substrate temperature increases. Also, dominance between VLS and VS is very critical to determine the shape of the products and the substitution of CdS by CdSe is very effective; hence, CdSe growth time should be chosen accordingly. However, it was shown two segmented products can be synthesized by picking the right conditions and with very careful analyses. We also demonstrated that simultaneous two colors lasing from a single segmented belt structures is possible with strong enough-pumping-power.
ContributorsTurkdogan, Sunay (Author) / Ning, Cun-Zheng (Thesis advisor) / Tao, Meng (Committee member) / Yu, Hongbin (Committee member) / Arizona State University (Publisher)
Created2012
Description
Recently a new materials platform consisting of semiconductors grown on GaSb and InAs substrates with lattice constants close to 6.1 A was proposed by our group for various electronic and optoelectronic applications. This materials platform consists of both II-VI (MgZnCdHg)(SeTe) and III-V (InGaAl)(AsSb) compound semiconductors, which have direct bandgaps spanning the entire energy spectrum from far-IR (~0 eV) up to UV (~3.4 eV). The broad range of bandgaps and material properties make it very attractive for a wide range of applications in optoelectronics, such as solar cells, laser diodes, light emitting diodes, and photodetectors. Moreover, this novel materials system potentially offers unlimited degrees of freedom for integration of electronic and optoelectronic devices onto a single substrate while keeping the best possible materials quality with very low densities of misfit dislocations. This capability is not achievable with any other known lattice-matched semiconductors on any available substrate. In the 6.1-A materials system, the semiconductors ZnTe and GaSb are almost perfectly lattice-matched with a lattice mismatch of only 0.13%. Correspondingly, it is expected that high quality ZnTe/GaSb and GaSb/ZnTe heterostructures can be achieved with very few dislocations generated during growth. To fulfill the task, their MBE growth and material properties are carefully investigated. High quality ZnTe layers grown on various III-V substrates and GaSb grown on ZnTe are successfully achieved using MBE. It is also noticed that ZnTe and GaSb have a type-I band-edge alignment with large band offsets (delta_Ec=0.934 eV, delta_Ev=0.6 eV), which provides strong confinement for both electrons and holes. Furthermore, a large difference in refractive index is found between ZnTe and GaSb (2.7 and 3.9, respectively, at 0.7 eV), leading to excellent optical confinement of the guided optical modes in planar semiconductor lasers or distributed Bragg reflectors (DBR) for vertical-cavity surface-emitting lasers. Therefore, GaSb/ZnTe double-heterostructure and ZnTe/GaSb DBR structure are suitable for use in light emitting devices. In this thesis work, experimental demonstration of these structures with excellent structural and optical properties is reported. During the exploration on the properties of various ZnTe heterostructures, it is found that residual tensile strains exist in the thick ZnTe epilayers when they are grown on GaAs, InP, InAs and GaSb substrates. The presence of tensile strains is due to the difference in thermal expansion coefficients between the epilayers and the substrates. The defect densities in these ZnTe layers become lower as the ZnTe layer thickness increases. Growth of high quality GaSb on ZnTe can be achieved using a temperature ramp during growth. The influence of temperature ramps with different ramping rates in the optical properties of GaSb layer is studied, and the samples grown with a temperature ramp from 360 to 470 C at a rate of 33 C/min show the narrowest bound exciton emission peak with a full width at half maximum of 15 meV. ZnTe/GaSb DBR structures show excellent reflectivity properties in the mid-infrared range. A peak reflectance of 99% with a wide stopband of 480 nm centered at 2.5 um is measured from a ZnTe/GaSb DBR sample of only 7 quarter-wavelength pairs.
ContributorsFan, Jin (Author) / Zhang, Yong-Hang (Thesis advisor) / Smith, David (Committee member) / Yu, Hongbin (Committee member) / Menéndez, Jose (Committee member) / Johnson, Shane (Committee member) / Arizona State University (Publisher)
Created2012
Description
What can classical chaos do to quantum systems is a fundamental issue highly relevant to a number of branches in physics. The field of quantum chaos has been active for three decades, where the focus was on non-relativistic quantumsystems described by the Schr¨odinger equation. By developing an efficient method to solve the Dirac equation in the setting where relativistic particles can tunnel between two symmetric cavities through a potential barrier, chaotic cavities are found to suppress the spread in the tunneling rate. Tunneling rate for any given energy assumes a wide range that increases with the energy for integrable classical dynamics. However, for chaotic underlying dynamics, the spread is greatly reduced. A remarkable feature, which is a consequence of Klein tunneling, arise only in relativistc quantum systems that substantial tunneling exists even for particle energy approaching zero. Similar results are found in graphene tunneling devices, implying high relevance of relativistic quantum chaos to the development of such devices. Wave propagation through random media occurs in many physical systems, where interesting phenomena such as branched, fracal-like wave patterns can arise. The generic origin of these wave structures is currently a matter of active debate. It is of fundamental interest to develop a minimal, paradigmaticmodel that can generate robust branched wave structures. In so doing, a general observation in all situations where branched structures emerge is non-Gaussian statistics of wave intensity with an algebraic tail in the probability density function. Thus, a universal algebraic wave-intensity distribution becomes the criterion for the validity of any minimal model of branched wave patterns. Coexistence of competing species in spatially extended ecosystems is key to biodiversity in nature. Understanding the dynamical mechanisms of coexistence is a fundamental problem of continuous interest not only in evolutionary biology but also in nonlinear science. A continuous model is proposed for cyclically competing species and the effect of the interplay between the interaction range and mobility on coexistence is investigated. A transition from coexistence to extinction is uncovered with a non-monotonic behavior in the coexistence probability and switches between spiral and plane-wave patterns arise. Strong mobility can either promote or hamper coexistence, while absent in lattice-based models, can be explained in terms of nonlinear partial differential equations.
ContributorsNi, Xuan (Author) / Lai, Ying-Cheng (Thesis advisor) / Huang, Liang (Committee member) / Yu, Hongbin (Committee member) / Akis, Richard (Committee member) / Arizona State University (Publisher)
Created2012
Description
Negative bias temperature instability (NBTI) is a leading aging mechanism in modern digital and analog circuits. Recent NBTI data exhibits an excessive amount of randomness and fast recovery, which are difficult to be handled by conventional power-law model (tn). Such discrepancies further pose the challenge on long-term reliability prediction under statistical variations and Dynamic Voltage Scaling (DVS) in real circuit operation. To overcome these barriers, the modeling effort in this work (1) practically explains the aging statistics due to randomness in number of traps with log(t) model, accurately predicting the mean and variance shift; (2) proposes cycle-to-cycle model (from the first-principle of trapping) to handle aging under multiple supply voltages, predicting the non-monotonic behavior under DVS (3) presents a long-term model to estimate a tight upper bound of dynamic aging over multiple cycles, and (4) comprehensively validates the new set of aging models with 65nm statistical silicon data. Compared to previous models, the new set of aging models capture the aging variability and the essential role of the recovery phase under DVS, reducing unnecessary guard-banding during the design stage. With CMOS technology scaling, design for reliability has become an important step in the design cycle, and increased the need for efficient and accurate aging simulation methods during the design stage. NBTI induced delay shifts in logic paths are asymmetric in nature, as opposed to averaging effect due to recovery assumed in traditional aging analysis. Timing violations due to aging, in particular, are very sensitive to the standby operation regime of a digital circuit. In this report, by identifying the critical moments in circuit operation and considering the asymmetric aging effects, timing violations under NBTI effect are correctly predicted. The unique contributions of the simulation flow include: (1) accurate modeling of aging induced delay shift due to threshold voltage (Vth) shift using only the delay dependence on supply voltage from cell library; (2) simulation flow for asymmetric aging analysis is proposed and conducted at critical points in circuit operation; (3) setup and hold timing violations due to NBTI aging in logic and clock buffer are investigated in sequential circuits and (4) proposed framework is tested in VLSI applications such DDR memory circuits. This methodology is comprehensively demonstrated with ISCAS89 benchmark circuits using a 45nm Nangate standard cell library characterized using predictive technology models. Our proposed design margin assessment provides design insights and enables resilient techniques for mitigating digital circuit aging.
ContributorsVelamala, Jyothi Bhaskarr (Author) / Cao, Yu (Thesis advisor) / Clark, Lawrence (Committee member) / Chakrabarti, Chaitali (Committee member) / Yu, Hongbin (Committee member) / Arizona State University (Publisher)
Created2012
Description
A novel strain sensing procedure using an optical scanning methodology and diffraction grating is explored. The motivation behind this study is due to uneven thermal strain distribution across semiconductor chips that are composed of varying materials. Due to the unique properties of the materials and the different coefficients of thermal expansion (CTE), one can expect the material that experiences the highest strain to be the most likely failure point of the chip. As such, there is a need for a strain sensing technique that offers a very high strain sensitivity, a high spatial resolution while simultaneously achieving a large field of view. This study goes through the optical setup as well as the evolution of the optical grating in an effort to improve the strain sensitivity of this setup.
ContributorsChen, George (Co-author) / Ma, Teng (Co-author) / Liang, Hanshuang (Co-author) / Song, Zeming (Co-author) / Nguyen, Hoa (Co-author) / Yu, Hongbin (Thesis director) / Jiang, Hanqing (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
Description
The zinc oxide nanowires being grown are not developing properly and need to be fixed. In order to do this, the furnace equipment and experimental procedure must be tested until the results produced yield acceptable quality zinc oxide nanowires. After experimentation the nanowires were produced to an acceptable quality. With quality nanowires to experiment with, testing began to examine the effects of different thicknesses of aluminum dopants. Once doped and annealed, the wires were transferred to a substrate with a grid so contact points could be applied. However; the experiment was phased out once this step was half way complete due to the lab shifting to examine co-doping zinc oxide nanowires as explored in part two of this paper. The goal of co-doping zinc oxide film is to create an ideal p
type relationship for power generation, so this project focuses on altering the electrical properties of zinc oxide through doping that will allow more energy to be generated from the solar panels than current zinc oxide solar panels. The zinc oxide film doped with manganese was sputtered onto a silicon substrate. The experiment failed to create a co-doped sample because an x-ray photoelectron spectroscopy reading of the sample proved no nitrogen existed in the zinc oxide doped with manganese film. This experiment leads into this research teams work with co-doping, so instead of viewing this project as a failure it is seen as a learning experience. The research team is examining the results and creating new experiments to run to fix the problem. I currently work with my mentor Dr. Hongbin Yu and Seung Ho Ahn while doing research.
type relationship for power generation, so this project focuses on altering the electrical properties of zinc oxide through doping that will allow more energy to be generated from the solar panels than current zinc oxide solar panels. The zinc oxide film doped with manganese was sputtered onto a silicon substrate. The experiment failed to create a co-doped sample because an x-ray photoelectron spectroscopy reading of the sample proved no nitrogen existed in the zinc oxide doped with manganese film. This experiment leads into this research teams work with co-doping, so instead of viewing this project as a failure it is seen as a learning experience. The research team is examining the results and creating new experiments to run to fix the problem. I currently work with my mentor Dr. Hongbin Yu and Seung Ho Ahn while doing research.
ContributorsBull, David Sean (Author) / Yu, Hongbin (Thesis director) / Ahn, Seung Ho (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2014-05
Description
Graphene, a one atomic thick planar sheet of carbon atoms, has a zero gap band structure with a linear dispersion relation. This unique property makes graphene a favorite for physicists and engineers, who are trying to understand the mechanism of charge transport in graphene and using it as channel material for field effect transistor (FET) beyond silicon. Therefore, an in-depth exploring of these electrical properties of graphene is urgent, which is the purpose of this dissertation. In this dissertation, the charge transport and quantum capacitance of graphene were studied. Firstly, the transport properties of back-gated graphene transistor covering by high dielectric medium were systematically studied. The gate efficiency increased by up to two orders of magnitude in the presence of a high top dielectric medium, but the mobility did not change significantly. The results strongly suggested that the previously reported top dielectric medium-induced charge transport properties of graphene FETs were possibly due to the increase of gate capacitance, rather than enhancement of carrier mobility. Secondly, a direct measurement of quantum capacitance of graphene was performed. The quantum capacitance displayed a non-zero minimum at the Dirac point and a linear increase on both sides of the minimum with relatively small slopes. The findings - which were not predicted by theory for ideal graphene - suggested that scattering from charged impurities also influences the quantum capacitance. The capacitances in aqueous solutions at different ionic concentrations were also measured, which strongly suggested that the longstanding puzzle about the interfacial capacitance in carbon-based electrodes had a quantum origin. Finally, the transport and quantum capacitance of epitaxial graphene were studied simultaneously, the quantum capacitance of epitaxial graphene was extracted, which was similar to that of exfoliated graphene near the Dirac Point, but exhibited a large sub-linear behavior at high carrier density. The self-consistent theory was found to provide a reasonable description of the transport data of the epitaxial graphene device, but a more complete theory was needed to explain both the transport and quantum capacitance data.
ContributorsXia, Jilin (Author) / Tao, N.J. (Thesis advisor) / Ferry, David (Committee member) / Thornton, Trevor (Committee member) / Tsui, Raymond (Committee member) / Yu, Hongbin (Committee member) / Arizona State University (Publisher)
Created2010
Description
ABSTRACT The Orpheus Male Chorus of Phoenix occupies and maintains an historical place in the musical and civic history of the City of Phoenix and the State of Arizona. Organized in November, 1929, the Orpheus Male Chorus of Phoenix (OMC) is the only performing arts organization in Phoenix that can claim eighty-one years of continuous performance. The chorus gained popularity locally, nationally, and internationally in its first five decades. The breadth of the chorus's recognition began to decline in the latter part of the 20th century, but the chorus still retains a loyal following of audience members. This study focuses on the first fifty years of the OMC, especially the period from 1946 to 1979, the years the chorus was under the direction of Ralph Hess. Through his leadership the group's popularity and recognition reached a peak, thanks largely to his emphasis on civic responsibility, ties to service organizations, and musical ability and showmanship. No scholarly publications exist regarding this organization. Several boxes of memorabilia housed in the Arizona Historical Society Museum in Tempe, Arizona, serve as the primary source of material for this study. Concert programs supply information about concert repertoire, advertising, and chorus history. Newspaper articles from local and international press offer reviews, announcements, and media perceptions of the chorus. Information illustrating the abundant civic engagement of the OMC appears in proclamations and awards from local, state, national, and international personalities. This objective information helps propel the story forward, as do the personal letters and stories contained within the collection. Because many documents from the latter part of the 1970s are missing, the primary source information becomes more anecdotal and subjective. This study illustrates some of the ways in which the OMC went beyond mere survival to occupy a significant place in the musical life of Phoenix. Engagement in civic and social functions and support for non-profit organizations established the chorus as more than just a musical ensemble. Their pursuit under Hess of "Cultural Citizenship" earned them international recognition as civic leaders and ambassadors of goodwill.
ContributorsButler, Robert C (Author) / Schildkret, David (Thesis advisor) / Holbrook, Amy (Committee member) / Doan, Jerry (Committee member) / Arizona State University (Publisher)
Created2010
Description
ABSTRACT Many musicians, both amateur and professional alike, are continuously seeking to expand and explore their performance literature and repertory. Introducing new works into the standard repertory is an exciting endeavor for any active musician. Establishing connections, commissioning new works, and collaborating on performances can all work together toward the acceptance and success of a composer's music within an instrument community. For the flute, one such composer is Daniel Dorff (b. 1956). Dorff, a Philadelphia-based composer, has written for symphony orchestra, clarinet, contrabassoon, and others; however, his award-winning works for flute and piccolo are earning him much recognition. He has written works for such illustrious flutists as Mimi Stillman, Walfrid Kujala, and Gary Schocker; his flute works have been recorded by Laurel Zucker, Pamela Youngblood and Lois Bliss Herbine; and his pieces have been performed and premiered at each of the National Flute Association Conventions from 2004 to 2009. Despite this success, little has been written about Dorff's life, compositional style, and contributions to the flute repertory. In order to further promote the flute works of Daniel Dorff, the primary focus of this study is the creation of a compact disc recording of Dorff's most prominent works for flute: April Whirlwind, 9 Walks Down 7th Avenue, both for flute and piano, and Nocturne Caprice for solo flute. In support of this recording, the study also provides biographical information regarding Daniel Dorff, discusses his compositional methods and ideology, and presents background information, description, and performance notes for each piece. Interviews with Daniel Dorff regarding biographical and compositional details serve as the primary source for this document. Suggestions for the performance of the three flute works were gathered through interviews with prominent flutists who have studied and performed Dorff's pieces. Additional performance suggestions for Nocturne Caprice were gathered through a coaching session between the author and the composer. This project is meant to promote the flute works of Daniel Dorff and to help establish their role in the standard flute repertory.
ContributorsRich, Angela Marie (Contributor) / Novak, Gail (Pianist) (Performer) / Buck, Elizabeth Y (Thesis advisor) / Hill, Gary W. (Committee member) / Holbrook, Amy (Committee member) / Schuring, Martin (Committee member) / Arizona State University (Publisher)
Created2010