Now showing items 7772-7791 of 19641

    • Gabriel Faure's "La Bonne Chanson", Opus 61 and "La Chanson d'Eve", Opus 95: Musical diversity versus thematic unity.

      Marsh, Stephanie.; Day, Larry (The University of Arizona., 1995)
      This document is a study of the musical and literary unity Gabriel Faure applied to the La Bonne chanson, Opus 61 and La Chanson d'Eve, Opus 95. This paper further is an in depth examination of the two versions of La Bonne chanson and how Faure uses the colorful string texture to specifically illustrate thematic material as well as textual themes. The original string quintet version will be analyzed in the voicing of string accompaniment illustrating just how Faure eliminates these unifying themes in each string color juxtaposed with thematic material in the piano accompaniment as well. In the second version, which is piano/vocal, these musical themes are far less distinct to the listener due to the complex thematic texture of the accompaniment.
    • Gaetano Donizetti, Saverio Mercadante, and the Evolution and Development of the Verdi Baritone

      Roe, Charles; Krueger, Nathan Elliott; Dauphinais, Kristin; Hirst, Grayson; Roe, Charles (The University of Arizona., 2011)
      The leading baritone roles in the operas of Giuseppe Verdi, known as Verdi baritone roles, presented new challenges for the singers who first interpreted these roles. Their demanding tessitura and complex characterizations tested the skill of a generation of singers who began their careers singing the roles of Gioacchino Rossini, Gaetano Donizetti, Saverio Mercadante, Vincenzo Bellini and Giovanni Pacini in the lighter, bel canto style. The purpose of this study is to examine the careers of singers active in Italy between 1830 and 1845 and to provide insight as to which roles written before the premiere of Verdi's Nabucco contained similar vocal and characterization demands. Through examination of available Italian opera house annals, ten singers were identified by the author as precursors to the Verdi baritone, and are categorized into three groups: the pre-Verdi baritones, the transitional baritones and the established Verdi baritones. A brief biography of each singer is included, as well as an appendix for each singer that includes roles performed, dates and locations of the performances. The title role in Donizetti's Torquato Tasso and the role of Manfredo in Mercadante's Il giuramento were determined to be the roles most similar to Verdi's Nabucco. Each role is analyzed in terms of characterization and tessitura demands, and is compared using tessitura charts that account for the frequency and duration of individual pitches. The roles are divided into sections, and each section is designated by its overall range, primary tessitura, secondary tessitura, and weighted pitches. These designations provide quantifiable evidence that each role presents similar challenges for the baritone.
    • The galactic center stellar population in the near-infrared.

      Haller, Joseph William.; Rieke, Marcia J.; Black, John H.; Kennicutt, Robert C.; Olszewski, Edward W. (The University of Arizona., 1992)
      Near infrared photometry is presented for 659 stars within 2.5' of the Galactic Center from three epochs of 2.2μm and one epoch of 1.6μm observations. The data were taken with a Rockwell 64 x 64 HgCdTe IR array at the Steward Observatory 1.6m telescope and are complete to m(K) = 11.0. Additional photometry at 3.4μm for a subsample of 258 stars taken with a 58 x 62 InSb array at CTIO is also included. The sample has an average (H-K)(OBS), which is consistent with a late-type population with (H-K)₀ = 0.3 and A(V) = 31.8 mag, and luminosities several magnitudes brighter than the Baade's Window AGB. A variability analysis shows 59 stars are long period variable candidates at the 3σ level. These stars show correlations in (H-K)₀ vs. (K-L)₀ and (K-L)₀ vs. Δm(K) consistent with Mira variables on the AGB. The LPV luminosities are consistent with a population fewx10⁸ yr old which is older than the Galactic Center central cluster stars and younger than bulge stars in Baade's Window, implying the Galactic Center has repeating episodes of star formation. Observations of the CO(v = 2 ← 0) 2.3μm absorption feature taken at the CTIO 4m with the IR Spectrometer Array of the unresolved stellar emission at 9 positions within 30'' of Sgr A* are presented. It is shown that the CO band strength is highly correlated with r(SgrA*) for radii less than R(CO) ≈ 8.5'' (0.28 pc). The Galactic rotation curve has a radial gradient of -16 km s⁻¹ arcsec⁻¹ inside r(SgrA*) ≈ 10'' (0.33 pc) where it reaches a minimum. Estimates of the enclosed mass vs. radius show there is (1.7 ± 0.3) x 10⁶ M(⊙) inside r(SgrA*) = 5.2'' (0.17 pc) with a mass-to-light ratio on the order of 10. Assuming the CO absorption samples stellar emission at each projected radius, these results are strong evidence for a massive black hole at the Galactic Center.
    • GALAXY ANGULAR MOMENTUM

      Thompson, Laird Alan, 1947- (The University of Arizona., 1974)
    • Galaxy Clusters in the Dark Energy Survey

      Rozo, Eduardo; McClintock, Thomas; Behroozi, Peter; Besla, Gurtina; Cheu, Elliott; Marrone, Dan; Pinto, Phil (The University of Arizona., 2018)
      Galaxy clusters are massive dark matter halos, with masses as high as a few times 10^15 M⊙, each hosting tens to hundreds of galaxies. In its first year of data, the Dark Energy Survey has detected more than 100,000 clusters and groups. The upcoming Large Synoptic Survey Telescope is poised to discover over an order of magnitude more. Both of these surveys are well positioned to use galaxy clusters to make leading constraints on cosmological parameters. Two critical components are necessary for a cluster cosmology analysis: measurements of cluster masses, and models of the abundance of dark matter halos. In this thesis I detail two studies on these topics. First, using data from the Dark Energy Survey Year 1 data release, we constrained the masses of redMaPPer clusters using weak lensing. The normalization of the mean mass–richness scaling relation was measured with 5 percent accuracy, the most accurate measurement made to date. Second, as part of the Aemulus Project, using a suite of 40 dark matter only N-body simulations in a multi-dimensional cosmological parameter space, we developed an emulator model that interpolates between these simulations to predict the halo mass function. The mass function emulator achieves better than 1 percent accuracy at mass scales necessary to perform cluster cosmology by using Gaussian Processes to interpolate the results from simulations. This fulfills the stringent requirements of the Large Synoptic Survey Telescope. Finally, I outline ongoing efforts to improve lensing models of galaxy clusters that will enable numerous avenues for performing abundance analyses.
    • GALDOS EN LA JAULA DE LA EPOPEYA: PRIMERA SERIE DE "EPISODIOS NACIONALES." (SPAIN, NOVEL, 19TH CENTURY, EPIC, HISTORY).

      TRIVINOS-ARANEDA, SEGUNDO GILBERTO. (The University of Arizona., 1985)
      Esta disertación estudia la Primera Serie de Episodios Nacionales con el propósito de refutar la tesis sobre el carácter esencialmente épico de este grupo novelístico, particularmente la afirmación según la cual determinados Episodios tienen todas las características propias de la epopeya. El estudio en el nivel de la historia y del discurso de la serie muestra que Galdós no escribió relatos con las características de la epopeya sino novelas singularizadas por el triunfo de los protagonistas y los narradores sobre la fascinación ejercida por la "épica militar" y sobre el discurso que la exalta. El desengaño de la identificación de la guerra con la fiesta (Capítulo 2); la metamorfosis de los combatientes en monstruos o demonios; la tensión voces del individuo-voces de la familia-voces de la humanidad; los motivos del naufragio y del niño abandonado; el sistema analógico que equipara los horrores de la guerra con los horrores del infierno o de la pesadilla (Capítulo 4); el contraste entre el discurso militarista y el discurso pacifista o el predominio de las historias de hombres anónimos y célebres que sueñan con la paz y no con la guerra (Capítulo 5) son las principales constantes que muestran la distancia irreductible entre el Episodio y la Epopeya. Es posible hablar de una épica galdosiana únicamente en el caso de comprenderse por tal la escritura del martirio de los hombres y naciones en la época de la "guerra nacional" sobre la "guerra caballeresca" (Capítulo 6). Este estudio no evidencia sólo el rechazo del Episodio a la represión ejercida en la Epopeya contra las voces amorosas, pacifistas o antiheroicas. Reducir la Primera Serie a su dimensión liberadora sería, sin duda, mistificador, pues ella tiene también un reverso represivo. El análisis de las ceremonias de expulsión o censura de los deseos guerreros, libertinos, románticos o revolucionarios (Capítulo 7) permite concluir que las novelas de guerra escritas por Galdós están regidas por la característica tal vez más distintiva de la novela realista del siglo XIX: el miedo a los deseos socialmente perturbadores o peligrosos.
    • Galois groups and Greenberg's conjecture

      McCallum, William G.; Marshall, David Clark (The University of Arizona., 2000)
      We consider the structure of a certain infinite Galois group over Q(ζp) the cyclotomic field of p-th roots of unity. Namely, we consider the Galois group of the maximal p-ramified pro- p-extension. Very little is known about this group. It has a free pro-p presentation in terms of g generators and s relations where g and s may be explicitly computed in terms of the p-rank of the class group of Q(ζp). The structure of the relations in the Galois group are shown to be very closely related to the relations in a certain Iwasawa module. The main result of this dissertation shows this Iwasawa module to be torsion free for a large class of cyclotomic fields. The result is equivalent to verifying Greenberg's pseudo-null conjecture for the given class of fields. As one consequence, we provide a large class of examples of cyclotomic fields which do not admit free pro-p-extensions of maximal rank.
    • Game-Enhanced Simulation as an Approach to Experiential Learning in Business English

      Warner, Chantelle; Punyalert, Sansanee; Warner, Chantelle; Dupuy, Beatrice; Reinhardt, Jonathon (The University of Arizona., 2017)
      This dissertation aims to integrate various learning approaches, i.e., multiple literacies, experiential learning, game-enhanced learning, and global simulation, into an extracurricular module, in which it remodels traditional ways of teaching input, specifically, the lexical- and grammatical-only approaches of business English at a private university in Bangkok, Thailand. Informed by those approaches, a game-enhanced simulation was specifically designed as an experiential space for L2 learners to experience the dynamic and real business contexts of language use. A strategy-simulation video game, RollerCoaster Tycoon 3 Platinum (RCT3), was selected and used in the implementation of the pilot course. The game was embedded in a global simulation of two amusement park companies – where students worked in groups of five to form characters and socially interact with others. The global simulation involved learners in a sequence of genre-based (e.g., memoranda and business presentations) and technology-based tasks (e.g., using Gmail, Google Docs, and LinkedIn). Ten second-year students from five disciplines – Accounting, Logistics Engineering, Technology and Creative Business, Logistics Management, and Airline Business Management, participated in the study. Within this game-enhanced simulation, it turned out that each student simulated the role of a department head that was relevant to her or his discipline, for example, department heads of Financial Management, Technical Service Management, Customer Relationship Management, Legal and Operations Management, and Human Capital Management. The findings show that the learners' interactivity within the gameplay depicted the pedagogical affordances of RCT3 for a business English simulation, that is, exploratory interactivity, goal-orientedness in gameplay, goal-orientedness for roleplaying, and emergent narratives. The data present how this videogame features an interplay between two game perspectives – ludology and narratology. That is, ludic affordances in RCT3 could be activated in a narrative system: meaningful personal or emergent narrative by well-designed global simulation tasks. The simulations were established through students’ interpretation and creativity in gameplay and roleplay as related to their disciplines. Moreover, the game-enhanced simulation appeared to provide learners with an effective social context for promoting global English development and professional identity formation, which moved them beyond the learning practices of traditional coursebooks and classroom settings. Students of the study had opportunities to use professional Discourses related to their disciplines as ways to establish their desired identities within the simulated global workplace.
    • Game-Theoretic Contract Models for Equipment Leasing and Maintenance Service Outsourcing

      Liao, Haitao; Hamidi, Maryam; Son, Young-Jun; Fan, Neng; An, Lingling; Liao, Haitao (The University of Arizona., 2016)
      There is a major trend that manufacturers sell their services to customers instead of selling their products. These services can be provided through leasing, warranty, or maintenance outsourcing. In this dissertation, we have studied leasing and maintenance outsourcing services from different aspects of reliability-based maintenance, game-theoretic decision making, and inventory and supply chain management. We have studied how different interactions and relationships between the manufacturer and customer in service contracting affect the decisions they make and the profits they gain. The methods used to tackle the related decision-making processes are stochastic modeling, non-convex optimization, game-theoretical framework, and simulation. For equipment leasing, two non-cooperative game-theoretic models and a cooperative model have been developed to describe the relationships between the manufacturer (lessor) and customer (lessee). Through the lease contracts, the lessor decides on the maintenance policy of the leased equipment, and the lessee decides on the lease period and usage rate. In the non-cooperative simultaneous move scenario, the lessee and the lessor act simultaneously and independently to make their decisions. In the leader-follower non- cooperative contract, the lessor is the leader who specifies the maintenance policy first, and the lessee, as the follower, decides on the lease period and usage rate accordingly. We have next determined the total maximum profit and shown that the Nash and Stackelberg equilibria are different from the total maximum solution. As a result, the players can increase their total profit by cooperation. We have implemented the cooperative solution as an equilibrium through a nonlinear transfer-payment contract. Our results illustrate that cooperation can be regarded as a value-added strategy in establishing such lease contracts. Besides, our numerical results show that although cooperation always increases the total profit of the players, the magnitude of increase is case specific. When the lease price is low or the revenue is high, the profits in the non-cooperative contracts will be close to the cooperative alternative, while the cooperation may increase the total profit significantly in other cases. For maintenance outsourcing, we have studied different bargaining scenarios in determining the contract terms. First, we have considered the Nash bargaining solution to compute the bargaining profit of players. Next, we have considered the case where players pose threat against each other in order to increase their own bargaining position. We have determined the optimal threat strategy for each player. Our result shows that although such threatening decreases the efficiency of the contract, it can dramatically increase the profit of the player with a higher bargaining position. We have finally provided a solution to the problem of how the service agent and customer can cooperate and negotiate on the price. We have determined the discounted price as a result of negotiation. Indeed, the discounted price induces the customer to choose the total maximum maintenance policy. Our numerical examples illustrate the feasibility of using such a price-discount contract in maintenance service outsourcing. Moreover, one can see that both the customer and agent can benefit from this price-discount contract.
    • Games of Decentralized Inventory Management

      Dror, Moshe; Summerfield, Nichalin Suakkaphong; Dror, Moshe; Walker, Mark; Reynolds, Stanley S (The University of Arizona., 2010)
      Any decentralized retail or wholesale system of competing entities requires a benefit sharing arrangement when competing entities collaborate after their demands are realized. For instance, consider a distribution system similar to the observed behavior of independent car dealerships. If a dealership does not have in stock the car requested by a customer, it might consider acquiring it from a competing dealer. Such behavior raises questions about competitive procurement strategies that achieve system optimal outcomes. This dissertation consists of three main bodies of work contained respectively in chapters 2, 3, and 4. In the first work -- chapter 2, we examine a decentralized system that adopts an ex-post agreed transfer payment approach proposed by Anupindi et al. (Manuf. Serv. Oper.Manag. 4(3):349-368, 2001). In particular, we state a set of conditions on cost parameters and distributions that guarantee uniqueness of pure strategy Nash equilibrium. In the second work -- chapter 3, we introduce a multilevel graph framework that links decentralized inventory distribution models as a network of stochastic programming with recourse problems. This framework depicts independent retailers who maximize their individual expected profits, with each retailer independently procuring inventory in the ex-ante stage in response to forecasted demand and anticipated cooperative recourse action of all retailers in the system. The graph framework clarifies the modeling connection between problems in a taxonomy of decentralized inventory distribution models. This unifying perspective links the past work and shades light on future research directions. In the last work -- chapter 4, we examine and recast the biform games modeling framework as two-stage stochastic programming with recourse. Biform games modeling framework addresses two-stage games with competitive first stage and cooperative second stage without ex-ante agreement on profit sharing scheme. The two-stage stochastic programming view of biform games is demonstrated on examples from all the known examples regarding operational decision problems of competing firms from the literature. It allows an “old” mathematical methodology to showcase its versatility in modeling combined competitive and cooperative game options. In short, this dissertation provides important insights, clarifications, and strategic limitations regarding collaborations in decentralized distribution system.
    • Gamma-ray Imaging Diagnostic for Inertial Confinement Fusion

      Barber, Herbert B.; Furenlid, Lars R.; Lemieux, Daniel; Grim, Gary P.; Sasian, Jose (The University of Arizona., 2018)
      In Livermore California at the Lawrence Livermore National Laboratory exists the National Ignition Facility (NIF). The NIF’s goal is to study high-density high-temperature plasmas and try and reach thermalnuclear fusion by a method known as Inertial Confinement Fusion (ICF). This occurs when 192 UV lasers interact with the inner walls of a gold cylinder, known as a hohlraum, and produce X-rays. Inside the hohlraum consists a capsule filled with deuterium and tritium. The X-rays ablate the outer plastic shell causing an inward shockwave to compress the D-T fuel to high density and undergo nuclear fusion. The fusion reaction creates 14.1 MeV neutrons that can interact with the carbon 12 of the plastic outer shell producing 4.44 MeV gammas from 12C(n,n’γ)12C reactions. This dissertation examines and produces a prototype system to image these 4.44 MeV gammas. This is a valuable diagnostic system that can characterize the symmetry of the ablated surface, which gives information as to how symmetrically the capsule is imploding. A prototype Gamma-Ray Imaging system (GRI) was built and tested at two large facilities. The first is another ICF facility that implodes capsules but at a much lower yield. These capsules produced X-rays in the ~300-400 keV range that were successfully imaged using the GRI system. The second facility is the High Intensity Gamma Source (HIGS) at Duke University that uses a free electron laser Compton scattered off a relativistic electron packet to produce a 4.7 MeV gamma beam. A number of radiograph shadow targets were placed in the 32 mm wide gamma beam and imaged by the GRI system. The results of these two test are discussed in this dissertation. The GRI system along with the Neutron Imaging System, and other diagnostics systems, are intended to compliment each other and provide useful information that can be used to design future capsules or diagnose poor implosions. This will help NIF achieve its goal of thermonuclear fusion.
    • Gamma-ray imaging probes.

      Bartels, Peter; Wild, Walter James. (The University of Arizona., 1988)
      External nuclear medicine diagnostic imaging of early primary and metastatic lung cancer tumors is difficult due to the poor sensitivity and resolution of existing gamma cameras. Nonimaging counting detectors used for internal tumor detection give ambiguous results because distant background variations are difficult to discriminate from neighboring tumor sites. This suggests that an internal imaging nuclear medicine probe, particularly an esophageal probe, may be advantageously used to detect small tumors because of the ability to discriminate against background variations and the capability to get close to sites neighboring the esophagus. The design, theory of operation, preliminary bench tests, characterization of noise behavior and optimization of such an imaging probe is the central theme of this work. The central concept lies in the representation of the aperture shell by a sequence of binary digits. This, coupled with the mode of operation which is data encoding within an axial slice of space, leads to the fundamental imaging equation in which the coding operation is conveniently described by a circulant matrix operator. The coding/decoding process is a classic coded-aperture problem, and various estimators to achieve decoding are discussed. Some estimators require a priori information about the object (or object class) being imaged; the only unbiased estimator that does not impose this requirement is the simple inverse-matrix operator. The effects of noise on the estimate (or reconstruction) is discussed for general noise models and various codes/decoding operators. The choice of an optimal aperture for detector count times of clinical relevance is examined using a statistical class-separability formalism.
    • Gamma-ray lines from asymmetric supernovae

      Pinto, Philip A.; Hungerford, Aimee L. (The University of Arizona., 2004)
      High energy emission from supernovae provide a direct window into the quantity and distribution of radioactive elements produced in these explosions. Combining supernova explosion calculations with 3D Monte Carlo gamma-ray transport, I have studied the effect mixing and asymmetries have on the hard X-ray and gamma-ray spectra. Two types of asymmetries (bipolar and unipolar) are investigated, the parameters of which are motivated by the most recent findings from multi-dimensional core-collapse supernova simulations. These bipolar and unipolar asymmetries are imposed artificially on 1-dimensional stellar progenitor structures and their evolution is followed using a 3-dimensional smoothed particle hydrodynamics (SPH) code. Global asymmetries in the explosion enhance the outward mixing of heavy elements such as 56Ni, reducing the observable emergence time for the hard X-ray continuum and gamma-ray line emission over that of symmetrically mixed models. The details of the velocity asymmetry lead to very different nickel distributions in the outer envelope. The high energy spectra resulting from these models predict an angular variation for the correspondence between the emergence time of the hard X-ray continuum and the broadening of the gamma-line profiles. The unipolar explosion models, in particular, demonstrate that redshifted gamma-ray line profiles are attainable at epochs where gamma-ray emission arises predominantly from the outer extent of the nickel distribution. The departure from a symmetric explosion scenario manifests itself most clearly in the extended nickel, making gamma-ray line observations an ideal probe of the initial explosion asymmetry.
    • Garcilaso en Italia: arte y política en la lírica del "Príncipe de la poesía española"

      Kinkade, Richard P.; Celaya Bustamante, Gaston A.; Fiore, Robert L.; Chuffe, Eliud; Kinkade, Richard P. (The University of Arizona., 2011)
      Este estudio analiza el contenido político en la poesía lírico-amorosa del poeta Garcilaso de la Vega y las repercusiones que ha tenido en el desarrollo y evolución de la literatura y la cultura del Siglo de oro español. En esta investigación se demuestra que existen motivaciones políticas específicas en el discurso lírico de Garcilaso, poeta considerado como el más amoroso, emotivo y sincero del Renacimiento español.La aproximación analítica aquí propuesta obedece al hecho de que la crítica tradicional ha dejado de lado el reconocimiento de las implicaciones que la poesía de Garcilaso ha tenido, en términos de lo político, en este período histórico-literario. Los criterios tradicionales generales en torno a los poemas de Garcilaso han señalado que sus poemas mejores logrados han sido aquellos en donde el poeta expresa sus más profundos, emotivos y sinceros sentimientos por su dama.Uno de los cometidos de este estudio consiste en demostrar que el valor de la poesía de Garcilaso no ha sido apreciado a cabalidad debido a la utilización del criterio de sinceridad para aproximarse a ella. Asimismo, el objetivo principal de este trabajo es establecer que mediante el reconocimiento del factor político en su poesía, así como la descripción y las formas en que es presentado, es posible revalorar la trascendencia que Garcilaso tuvo dentro del contexto de la evolución de la poesía española de los siglos XVI y XVII.
    • GARNET-ORTHOPYROXENE EQUILIBRIA IN THE FMAS SYSTEM: EXPERIMENTAL AND THEORETICAL STUDIES, AND GEOLOGICAL APPLICATIONS (GEOTHERMOMETRY, GEOBAROMETRY).

      Ganguly, J.; LEE, HAN YEANG.; Damon, P.; Drake, M.; Eastoe, C.; Ruiz, J. (The University of Arizona., 1986)
      Equilibrium relations between garnet and orthopyroxene have been investigated by reversal experiments in the range of 20-45Kb and 975-1400°C in the FeO-MgO-Al₂O₃-SiO₂(FMAS) system. The Fe-Mg exchange reaction seems to have little or no compositional dependence at these conditions. The experimental results can be fitted adequately by the linear relation: ln K(D) = 2243/T°K - 0.9522 at 25Kb where K(D) = (X(Fe)/X(Mg))ᴳᵗ/(X(Fe)/X(Mg))ᴼᵖˣ. Combination of the available data for the mixing properties of garnet and V° for the Fe-Mg exchange reaction with the above experimental results yields the following geothermometric expression for the common natural assemblages that can be represented essentially within the system CaO-MnO-FeO-MgO-Al₂O₃-SiO₂. T°K = (1968 + 11P(Kb) + 1510(X(Ca)+X(Mn))ᴳᵗ)/(ln K(D) + 0.9522). The stability field of pyrope+quartz, defined by the reaction pryope+quartz=opx+sill, has been calculated as a function of P,T,X(Fe)ᴳᵗ in the FMAS system using the reversal experimental data of Perkins (1983) in the MAS system, and the present data on K(D)(Fe-Mg) between garnet and orthopyroxene. This reaction is very sensitive to pressure and compositional effects. Combination of P,T conditions for the garnet stability and that defined by (K(D)(Fe-Mg))ᴳᵗ⁻ᴼᵖˣ yields a simultaneous solution for both P and T of equilibration of garnet and orthopyroxene in the presence of Al₂SiO₅ and SiO₂. The effect of FeO on Al₂O₃ solubility in orthopyroxene in equilibrium with garnet has been determined experimentally at several pressures at 975 and 1200°C. These data have been modeled to develop a thermodynamic method for the calculation of Al₂O₃ in orthopyroxene as a function of P,T and composition. The Al₂O₃ isopleths have moderate P-T slopes, and provide virtually the only means of determining the pressure of mantle derived rocks.
    • Garnet: A graph-based octilinear mixed-signal Steiner tree routing system

      Carothers, Jo Dale; Newbould, Rexford D. (The University of Arizona., 2004)
      A compatibility graph-based, general area router for integrated circuit (IC) designs is presented. The highly flexible constraint system allows a number of modern and mixed-signal routing requirements to be handled, even for a large number of nets. The IC router can efficiently construct near-minimal Steiner trees for multi-terminal nets in both classical rectilinear, or Manhattan, geometry as well as octilinear geometries. These Steiner trees can be constructed around blockages, and in the presence of obstacles such as other nets. A method for routing trees through weighted areas is also introduced. The routing system can predict congested routing areas before routing is performed, and appropriately weight congested areas in order to reduce net congestion. Finally, a fast crosstalk violation checker can run alongside the routing engine. Each portion of the router is bounded by O(n log(n)) runtime, or less, making the entire routing process bounded by the same runtime. The system thus scales well to handle a very large number of exact routes in a fully mixed-signal aware engine, in either rectilinear or newly-introduced octilinear geometries.
    • THE GAS COMPOSITION AND VERTICAL CLOUD STRUCTURE OF JUPITER'S TROPOSPHERE DERIVED FROM FIVE MICRON SPECTROSCOPIC OBSERVATIONS.

      Larson, Harold P.; BJORAKER, GORDON LEE. (The University of Arizona., 1985)
      Spectroscopic observations of Jupiter at 5 microns were analyzed in order to derive the gas composition and vertical cloud structure for the 2 to 6 bar portion of the Jovian troposphere. Two infrared data sets were used. The first one consisted of high spectral resolution observations of Jupiter between -40 and +40 latitude acquired from the Kuiper Airborne Observatory. The second data set consisted of high spatial resolution measurements of Jupiter's belts and zones using the Voyager 1 Infrared Interferometer Spectrometer and Radiometer (IRIS). A spectrum synthesis program was used to calculate the emergent radiance from Jupiter's atmosphere between 1800 and 2250 cm⁻¹. The temperature-pressure profile and spectroscopic line parameters for seven molecules were specified. Gas mole fractions were adjusted until the calculated spectrum agreed with the observations within error limits. Molecular hydrogen is an important absorber at 5 microns. Absorption coefficients were generated as functions of frequency and temperature. Unit optical depth at 5 microns due to H₂ takes place between 5 and 7 bars in Jupiter's atmosphere. The airborne spectrum was used to infer the mole fractions of NH₃, PH₃, CH₄, CH₃D, CO, GeH₄, and H₂O for the 2 to 6 bar portion of Jupiter's troposphere. Elemental ratios were calculated and compared with model predictions. The N/H ratio is 1.5 ± 0.2 times the Lambert (1978) values for the Sun. The P/H ratio is 1.0 ± 0.1 times the Anders and Ebihara (1982) meteoritic value. The C/H ratio is 3.6 ± 0.7 times solar. The D/H ratio is 1.2 x 10⁻⁵. The mole fractions of CO and GeH₄ are (1.0 ± 0.3) x 10⁻⁹ and (7.0 ± 4) x 10⁻¹⁰, respectively. The mole fraction of H₂O was found to be the same in Jupiter's belts and zones, except for a factor of 2 depletion in the North Equatorial Belt Hot Spots. The H₂O mole fraction for the 2 to 4 bar region is (4.0 ± 1.0) x 10⁻⁶. This value increases with depth to (3.0 ± 2.0) x 10⁻⁵ at 6 bars. The H₂O ice cloud would be located near 2 bars. The O/H ratio at P = 6 bars is depleted by a factor of 40 with respect to the Sun. The thermal emission signature at 5 microns of optically thick clouds was used to develop a one-dimensional cloud model for Jupiter. The belt-to-zone variation in 5 micron flux is attributed to a massive cloud layer at 2 bars, T = 200 K, composed of NH₄SH and H₂O ice. A lower cloud at 5 bars is inconsistent with the IRIS data. Continuum absorption by H₂ determines the penetration depth at 5 microns, not a lower cloud layer.
    • Gas permeability changes in rock salt during deformation.

      Daemen, J.; Stormont, John Charles.; Farmer, I.; Harpalani, S.; Desai, C.; Kiousis, P. (The University of Arizona., 1990)
      A laboratory, field and numerical study of the changes in gas permeability which rock salt experiences during deformation is given. The laboratory tests involves gas permeability and porosity measurements coincident with hydrostatic and triaxial quasi-static, stress-rate controlled compression tests. The permeability and porosity of the as-received samples decrease significantly as a result of hydrostatic loading. These changes are largely irreversible, and are believed to "heal" or return the rock to a condition comparable to its undisturbed state. Deviatoric loading induces a dramatic change in pore structure. The permeability can increase more than 5 orders of magnitude over the initial (healed) state as the samples are loaded. The gas permeability changes are consistent with flow paths initially developing along the grain boundaries and then along axial secondary tensile cracks. The results from two sets of in situ gas permeability measurements from the underground workings of the WIPP Facility are given. The results consistently indicate that there is no measurable gas permeability prior to disturbing the rock by excavation. In the immediate vicinity of an excavation, the gas permeability can be 5 orders of magnitude greater than the undisturbed permeability. A numerical procedure to predict the in situ permeability is developed based on the results of the laboratory tests. The stress and strain fields surrounding excavations in rock salt, predicted with an elastoplastic model, are used in a model of gas permeability based on the equivalent channel model. The zone of the gas permeable rock is predicted well, but the magnitude of the gas permeability is underpredicted very near excavations. The gas permeability which develops in situ is principally a result of flow along dilated grain boundaries.
    • Gas Phase Etching of Silicon Dioxide Films

      Muscat, Anthony J.; Montano, Gerardo; Muscat, Anthony J.; Shadman, Farhang; Ogden, Kimberly (The University of Arizona., 2006)
      The gas phase etching of thermal silicon dioxide films was investigated with in situ Fourier Transformed Infrared Spectroscopy (FTIR) and ex situ X-ray Photoelectron Spectroscopy (XPS). The initiation process, the bulk etching of the oxide, and the termination mechanism were characterized as a function of reactant concentration, temperature, and pressure. The experiments were carried out in a custom made vessel with a gas panel and a data acquisition and control system (DA&C) capable of lowering flow and pressure disturbances originated by reactant introduction. The FTIR technique used to monitor the reaction in real time allowed distinguishing reactions that initiated in a gas/solid regime from reactions that started in a gas/liquid/solid regime. This study was focused on the gas/solid initiation process in order to expand the general assumption in published works that a condensed layer is previously required to initiate and sustain the reaction. It was found in this investigation that, depending on the experimental parameters, the water layer is not always a requisite for the initiation of the reaction but a consequence of the etching process. The FTIR data also showed the role in the initiation process of gas phase heterogeneous associated species, specifically (HF)H₂O and (HF)₂H₂O. After the initiation period, the experimental conditions determined the amount of water present on the surface of the sample, which in turn determined the local environment of the reaction and by extension the etching species. Reactions developing in a gas/solid regime were found to be slow, with etching rates of less than 1 °A/sec. Contrarily, reactions taking place in a gas/liquid/solid regime reached etching rates of 100 °A/sec, a maximum value determined by transport limitations. The condensed layer was found to be especially sensitive to temperature since a variation of 15 ° C changed the local environment from gas/liquid/solid to gas/solid. Finally, it was corroborated through the XPS analysis that the removal process in the gas phase leaves the silicon surfaces with high fluorine and oxygen concentrations in the form of SiFₓ and SiOH.