• 3D Imaging Millimeter Wave Circular Synthetic Aperture Radar

      Zhang, Renyuan; Cao, Siyang; Univ Arizona, Dept Elect & Comp Engn (MDPI AG, 2017-06-17)
      In this paper, a new millimeter wave 3D imaging radar is proposed. The user just needs to move the radar along a circular track, and high resolution 3D imaging can be generated. The proposed radar uses the movement of itself to synthesize a large aperture in both the azimuth and elevation directions. It can utilize inverse Radon transform to resolve 3D imaging. To improve the sensing result, the compressed sensing approach is further investigated. The simulation and experimental result further illustrated the design. Because a single transceiver circuit is needed, a light, affordable and high resolution 3D mmWave imaging radar is illustrated in the paper.
    • 3D imaging of gems and minerals by multiphoton microscopy

      Cromey, Benjamin; Knox, Ryan J.; Kieu, Khanh; Univ Arizona, Coll Opt Sci (OPTICAL SOC AMER, 2019-02-01)
      Many optical approaches have been used to examine the composition and structure of gemstones, both recently and throughout history. The nonlinear optical behavior of different gemstones has not been investigated, and the higher order terms to the refractive index represent an unused tool for qualifying and examining a stone. We have used a multiphoton microscope to examine the nonlinear optical properties of 36 different gemstones and demonstrate that it is a useful tool for imaging them three-dimensionally up to the millimeter scale below the sample surface. The polarization dependence of second harmonic generation signals was used to examine the crystal orientations inside the minerals. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
    • 3D Local Earthquake Tomography of the Ecuadorian Margin in the Source Area of the 2016 Mw 7.8 Pedernales Earthquake

      León-Ríos, S.; Bie, L.; Agurto-Detzel, H.; Rietbrock, A.; Galve, A.; Alvarado, A.; Beck, S.; Charvis, P.; Font, Y.; Hidalgo, S.; et al. (Blackwell Publishing Ltd, 2021)
      Based on manually analyzed waveforms recorded by the permanent Ecuadorian network and our large aftershock deployment installed after the Pedernales earthquake, we derive three-dimensional Vp and Vp/Vs structures and earthquake locations for central coastal Ecuador using local earthquake tomography. Images highlight the features in the subducting and overriding plates down to 35 km depth. Vp anomalies (∼4.5–7.5 km/s) show the roughness of the incoming oceanic crust (OC). Vp/Vs varies from ∼1.75 to ∼1.94, averaging a value of 1.82 consistent with terranes of oceanic nature. We identify a low Vp (∼5.5 km/s) region extending along strike, in the marine forearc. To the North, we relate this low Vp and Vp/Vs (<1.80) region to a subducted seamount that might be part of the Carnegie Ridge (CR). To the South, the low Vp region is associated with high Vp/Vs (>1.85) which we interpret as deeply fractured, probably hydrated OC caused by the CR being subducted. These features play an important role in controlling the seismic behavior of the margin. While subducted seamounts might contribute to the nucleation of intermediate megathrust earthquakes in the northern segment, the CR seems to be the main feature controlling the seismicity in the region by promoting creeping and slow slip events offshore that can be linked to the updip limit of large megathrust earthquakes in the northern segment and the absence of them in the southern region over the instrumental period. © 2021. The Authors.
    • 3D Nanophotonic device fabrication using discrete components

      Melzer, Jeffrey E.; McLeod, Euan; Univ Arizona, Coll Opt Sci; Univ Arizona, Dept Biomed Engn (WALTER DE GRUYTER GMBH, 2020-06-06)
      Three-dimensional structure fabrication using discrete building blocks provides a versatile pathway for the creation of complex nanophotonic devices. The processing of individual components can generally support high-resolution, multiple-material, and variegated structures that are not achievable in a single step using top-down or hybrid methods. In addition, these methods are additive in nature, using minimal reagent quantities and producing little to no material waste. In this article, we review the most promising technologies that build structures using the placement of discrete components, focusing on laser-induced transfer, light-directed assembly, and inkjet printing. We discuss the underlying principles and most recent advances for each technique, as well as existing and future applications. These methods serve as adaptable platforms for the next generation of functional three-dimensional nanophotonic structures.
    • 3D propagation of relativistic solar protons through interplanetary space

      Dalla, S.; de Nolfo, G. A.; Bruno, A.; Giacalone, J.; Laitinen, T.; Thomas, S.; Battarbee, M.; Marsh, M. S.; Univ Arizona (EDP SCIENCES S A, 2020-07)
      Context. Solar energetic particles (SEPs) with energy in the GeV range can propagate to Earth from their acceleration region near the Sun and produce ground level enhancements (GLEs). The traditional approach to interpreting and modelling GLE observations assumes particle propagation which is only parallel to the magnetic field lines of interplanetary space, that is, spatially 1D propagation. Recent measurements by PAMELA have characterised SEP properties at 1 AU for the similar to 100 MeV-1 GeV range at high spectral resolution.Aims. We model the transport of GLE-energy solar protons using a 3D approach to assess the effect of the heliospheric current sheet (HCS) and drifts associated to the gradient and curvature of the Parker spiral. We derive 1 AU observables and compare the simulation results with data from PAMELA.Methods. We use a 3D test particle model including a HCS. Monoenergetic populations are studied first to obtain a qualitative picture of propagation patterns and numbers of crossings of the 1 AU sphere. Simulations for power law injection are used to derive intensity profiles and fluence spectra at 1 AU. A simulation for a specific event, GLE 71, is used for comparison purposes with PAMELA data.Results. Spatial patterns of 1 AU crossings and the average number of crossings per particle are strongly influenced by 3D effects, with significant differences between periods of A(+) and A(-) polarities. The decay time constant of 1 AU intensity profiles varies depending on the position of the observer and it is not a simple function of the mean free path as in 1D models. Energy dependent leakage from the injection flux tube is particularly important for GLE energy particles, resulting in a rollover in the spectrum.
    • 3D Simulations and MLT. I. Renzini’s Critique

      Arnett, W. David; Meakin, Casey; Hirschi, Raphael; Cristini, Andrea; Georgy, Cyril; Campbell, Simon; Scott, Laura J. A.; Kaiser, Etienne A.; Viallet, Maxime; Mocák, Miroslav; et al. (IOP PUBLISHING LTD, 2019-08-27)
      Renzini wrote an influential critique of "overshooting" in mixing-length theory (MLT), as used in stellar evolution codes, and concluded that three-dimensional fluid dynamical simulations were needed. Such simulations are now well tested. Implicit large eddy simulations connect large-scale stellar flow to a turbulent cascade at the grid scale, and allow the simulation of turbulent boundary layers, with essentially no assumptions regarding flow except the number of computational cells. Buoyant driving balances turbulent dissipation for weak stratification, as in MLT, but with the dissipation length replacing the mixing length. The turbulent kinetic energy in our computational domain shows steady pulses after 30 turnovers, with no discernible diminution; these are caused by the necessary lag in turbulent dissipation behind acceleration. Interactions between coherent turbulent structures give multi-modal behavior, which drives intermittency and fluctuations. These cause mixing, which may justify use of the instability criterion of Schwarzschild rather than the Ledoux. Chaotic shear flow of turning material at convective boundaries causes instabilities that generate waves and sculpt the composition gradients and boundary layer structures. The flow is not anelastic; wave generation is necessary at boundaries. A self-consistent approach to boundary layers can remove the need for ad hoc procedures of "convective overshooting" and "semi-convection." In Paper II, we quantify the adequacy of our numerical resolution in a novel way, determine the length scale of dissipation—the "mixing length"—without astronomical calibration, quantify agreement with the four-fifths law of Kolmogorov for weak stratification, and deal with strong stratification.
    • 3D visualization of optical ray aberration and its broadcasting to smartphones by ray aberration generator

      Hellman, Brandon; Bosset, Erica; Ender, Luke; Jafari, Naveed; McCann, Phillip; Nguyen, Chris; Summitt, Chris; Wang, Sunglin; Takashima, Yuzuru; Univ Arizona (SPIE-INT SOC OPTICAL ENGINEERING, 2017-11-27)
      The ray formalism is critical to understanding light propagation, yet current pedagogy relies on inadequate 2D representations. We present a system in which real light rays are visualized through an optical system by using a collimated laser bundle of light and a fog chamber. Implementation for remote and immersive access is enabled by leveraging a commercially available 3D viewer and gesture-based remote controlling of the tool via bi-directional communication over the Internet.

      Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica J.; Fumagalli, Mattia; Maseda, Michael V.; Leja, Joel; Franx, Marijn; et al. (IOP PUBLISHING LTD, 2016-08-11)
      We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H-140 imaging, parallel ACS G800L spectroscopy, and parallel I-814 imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to JH(IR) <= 24 (79,609 unique objects down to JH(IR) <= 26). Of these, 5459 galaxies are at z > 1.5 and 9621 are at 0.7 < z < 1.5, where Ha falls in the G141 wavelength coverage. The typical redshift error for JH(IR) <= 24 galaxies is sigma(z) approximate to 0.003 x (1 + z), i.e., one native WFC3 pixel. The 3 sigma limit for emission line fluxes of point sources is 2.1 x 10(-17) erg s(-1) cm(-2). All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.(18)
    • 3D-printed tubes with complex internal fins for heat transfer enhancement—CFD analysis and performance evaluation

      Wei, Chao; Vasquez Diaz, Gabriel Alexander; Wang, Kun; Li, Peiwen; Univ Arizona, Dept Aerosp & Mech Engn (AMER INST MATHEMATICAL SCIENCES-AIMS, 2019-12-27)
      Additive manufacturing (AM), also known as 3D printing technology, is applied to fabricate complex fin structures for heat transfer enhancement at inner surface of tubes, which conventional manufacturing technology cannot make. This work considered rectangular fins, scale fins, and delta fins with staggered alignment at the inner wall of heat transfer tubes for heat transfer enhancement of internal flows. Laminar flow convective heat transfer at 500 < Re < 2000 has been numerically studied, and heat transfer performance of the tubes with 3D-printed interrupted fins has been compared to that with conventional straight continuous fins and smooth tubes. The benefit from heat transfer enhancement and the loss due to increased pumping pressure is evaluated using the total entropy generation rate in the control volume of heat transfer tube. The heat transfer coefficient in tubes with interrupted fins in staggered arrangement can have 2.6 times of that of smooth tube and 1.4 times of that with conventional continuous straight fins. The entropy generation in the tubes with interrupted fins in staggered arrangement only has 30-50% of that of smooth tube or tube with traditional continuous straight fins. The benefit of using interrupted fins in staggered arrangement is significant.
    • 3He-rich Solar Energetic Particle Observations at the Parker Solar Probe and near Earth

      Wiedenbeck, M. E.; Bučík, R.; Mason, G. M.; Ho, G. C.; Leske, R. A.; Cohen, C. M. S.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; Desai, M. I.; et al. (IOP PUBLISHING LTD, 2020-02-03)
      The Integrated Science Investigation of the Sun (IS circle dot IS) instrument suite on the Parker Solar Probe (PSP) spacecraft is making in situ observations of energetic ions and electrons closer to the Sun than any previous mission. Using data collected during its first two orbits, which reached perihelion distances of 0.17 au, we have searched for He-3-rich solar energetic particle (SEP) events under very quiet solar minimum conditions. On 2019-110-111 (April 20-21), He-3-rich SEPs were observed at energies near 1MeV nucleon(-1) in association with energetic protons, heavy ions, and electrons. This activity was also detected by the Ultra-Low-Energy Isotope Spectrometer and the Electron, Proton, and Alpha Monitor instruments on the Advanced Composition Explorer (ACE) spacecraft located near Earth, 0.99 au from the Sun. At that time, PSP and ACE were both magnetically connected to locations near the west limb of the Sun. Remote sensing measurements showed the presence of type III radio bursts and also helical jets from this region of the Sun. This combination of observations is commonly associated with He-3-rich SEP acceleration on the Sun. AR 12738, which was located at Carrington coordinates from which numerous X-ray flares were observed over a period of more than 6 months, was identified as the source of the He-3-rich events. This region was also the source of several other SEP events detected at PSP or ACE. Aside from the period in 2019 April, IS circle dot IS did not observe any other He-3-rich SEPs during orbits 1 and 2.
    • The 4-Celled Tetrabaena socialis Nuclear Genome Reveals the Essential Components for Genetic Control of Cell Number at the Origin of Multicellularity in the Volvocine Lineage

      Featherston, Jonathan; Arakaki, Yoko; Hanschen, Erik R; Ferris, Patrick J; Michod, Richard E; Olson, Bradley J S C; Nozaki, Hisayoshi; Durand, Pierre M; Univ Arizona, Dept Ecol & Evolutionary Biol (OXFORD UNIV PRESS, 2018-04)
      Multicellularity is the premier example of a major evolutionary transition in individuality and was a foundational event in the evolution of macroscopic biodiversity. The volvocine chlorophyte lineage is well suited for studying this process. Extant members span unicellular, simple colonial, and obligate multicellular taxa with germ-soma differentiation. Here, we report the nuclear genome sequence of one of the most morphologically simple organisms in this lineage-the 4-celled colonial Tetrabaena socialis and compare this to the three other complete volvocine nuclear genomes. Using conservative estimates of gene family expansions a minimal set of expanded gene families was identified that associate with the origin of multicellularity. These families are rich in genes related to developmental processes. A subset of these families is lineage specific, which suggests that at a genomic level the evolution of multicellularity also includes lineagespecific molecular developments. Multiple points of evidence associate modifications to the ubiquitin proteasomal pathway (UPP) with the beginning of coloniality. Genes undergoing positive or accelerating selection in the multicellular volvocines were found to be enriched in components of the UPP and gene families gained at the origin of multicellularity include components of the UPP. A defining feature of colonial/multicellular life cycles is the genetic control of cell number. The genomic data presented here, which includes diversification of cell cycle genes and modifications to the UPP, align the genetic components with the evolution of this trait.
    • 4-H Youth Development Programming in Indigenous Communities: A Critical Review of Cooperative Extension Literature

      Farella, J.; Hauser, M.; Parrott, A.; Moore, J.D.; Penrod, M.; Elliott-Engel, J.; University of Arizona (Extension Journal, Inc., 2021)
      A literature review was conducted using the key words relating to Native American Youth and 4-H to assess the current state of 4-H youth programming serving First Nation/ Indigenous populations to inform future Extension initiatives. A systematic and qualitative review determined what level of focus the conducted programming efforts placed on broadly accepted elements of cultural identity as noted in the Peoplehood Model. A very small number of articles (N=13) were found pertaining to 4-H and Indigenous Communities. Fewer demonstrated emphasis on the peoplehood elements of language, place, traditional ceremony or calendars, and history. This work investigates a continuing inequity in 4-H PYD-both in service and reporting-and suggests some next steps for creating a more inclusive 4-H program for Native American/First Nation/Indigenous youth. © 2021. All Rights Reserved.
    • 4.7 THz asymmetric beam multiplexer for GUSTO

      Mirzaei, B.; Gan, Y.; Finkel, M.; Groppi, C.; Young, A.; Walker, C.; Hu, Q.; Gao, J.-R.; Steward Observatory, University of Arizona (The Optical Society, 2021)
      A full demonstration of the Fourier phase grating used as 4.7 THz local oscillator (LO) multiplexer for Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) is presented in this paper, including its design, modeling, tolerance analysis, and experimental characterizations of the angular and intensity distributions among 2 × 4 output beams and the power efficiency. A quantum cascade laser (QCL) is used to generate the input beam for evaluation of the grating performance in its all relevant aspects with an accuracy level never reported before, where good agreements with modeling results are found. This is the first asymmetric-profile grating fully modelled and characterized at a THz frequency, that further confirms the versatility of this technology for providing an intermediate optical element for feeding multiple array detectors with a single radiation source at such a scientifically interesting frequency regime. © 2021 Journal.
    • 4×2 HEB receiver at 4.7 THz for GUSTO

      Silva, Jose R.; Mirzaei, Behnam; Laauwen, Wouter; Hu, Qing; Groppi, Christopher E.; Walker, Christopher; Gao, Jian-Rong; More, Nikhil; Young, Abram; Khalatpour, Ali; et al. (SPIE-INT SOC OPTICAL ENGINEERING, 2018)
      GUSTO will be a NASA balloon borne terahertz observatory to be launched from Antarctica in late 2021 for a flight duration of 100-170 days. It aims at reviewing the life cycle of interstellar medium of our galaxy by simultaneously mapping the three brightest interstellar cooling lines: [OI] at 4.7 THz, [CII] at 1.9 THz, and [NII] at 1.4 THz; along 124 degrees of the galactic plane and through a part of the Large Magellanic Cloud. It will use three arrays of 4x2 mixers based on NbN hot electron bolometers (HEBs), which are currently the most sensitive mixers for high resolution spectroscopic astronomy at these frequencies. Here we report on the design of a novel 4.7 THz receiver for GUSTO. The receiver consists mainly of two subsystems: a 4x2 HEB quasi-optical mixer array and a 4.7 THz multi-beam LO. We describe the mixer array, which is designed as a compact monolithic unit. We show, for example, 10 potential HEB detectors with the state of the art sensitivity of 720 K measured at 2.5 THz. They have a variation in sensitivity smaller than 3%, while also meeting the LO uniformity requirements. For the multi-beam LO we demonstrate the combination of a phase grating and a single QCL at 4.7 THz, which generates 8 sub-LO beams, where the phase grating shows an efficiency of 75%. A preliminary concept for the integrated LO unit, including QCL, phase grating and beam matching optics is presented.
    • 5 kW Near-Diffraction-Limited and 8 kW High-Brightness Monolithic Continuous Wave Fiber Lasers Directly Pumped by Laser Diodes

      Fang, Qiang; Li, Jinhui; Shi, Wei; Qin, Yuguo; Xu, Yang; Meng, Xiangjie; Norwood, Robert A.; Peyghambarian, Nasser; Univ Arizona, Coll Opt Sci (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2017-10)
      Tandem pumping technique are traditionally adopted to develop > 3-kW continuous-wave (cw) Yb3+-doped fiber lasers, which are usually pumped by other fiber lasers at shorter wavelengths (1018 nm e.g.). Fiber lasers directly pumped by laser diodes have higher wall-plug efficiency and are more compact. Here we report two high brightness monolithic cw fiber laser sources at 1080 nm. Both lasers consist of a cw fiber laser oscillator and one laser-diode pumped double cladding fiber amplifier in the master oscillator-power amplifier configuration. One laser, using 30-mu m-core Yb3+-doped fiber as the gain medium, can produce > 5-kW average laser power with near diffraction-limited beam quality (M-2<1.8). The slope efficiency of the fiber amplifier with respect to the launched pump power reached 86.5%. The other laser utilized 50-mu m-core Yb3+-doped fiber as the gain medium and produced > 8-kW average laser power with high beam quality (M-2: similar to 4). The slope efficiency of the fiber amplifier with respect to the launched pump power reach 83%. To the best of our knowledge, this is the first detailed report for > 5-kW near-diffraction-limited and > 8-kW high-brightness monolithic fiber lasers directly pumped by laser diodes.
    • 5-HT1F receptor-mediated mitochondrial biogenesis for the treatment of Parkinson's disease

      Scholpa, Natalie E.; Lynn, Mary K.; Corum, Daniel; Boger, Heather A.; Schnellmann, Rick G.; Univ Arizona, Dept Pharmacol & Toxicol, Coll Pharm (WILEY, 2018-01)
      Background and PurposeParkinson's disease is characterized by progressive decline in motor function due to degeneration of nigrostriatal dopaminergic neurons, as well as other deficits including cognitive impairment and behavioural abnormalities. Mitochondrial dysfunction, leading to loss of ATP-dependent cellular functions, calcium overload, excitotoxicity and oxidative stress, is implicated in the pathophysiology of Parkinson's disease. Using the 5-HT1F receptor agonist LY344864, a known inducer of mitochondrial biogenesis (MB), we investigated the therapeutic efficacy of stimulating MB on dopaminergic neuron loss in a mouse model of Parkinson's disease. Experimental ApproachMale C57BL/6 mice underwent bilateral intrastriatal 6-hydroxydopamine or saline injections and daily treatment with 2mgkg(-1) LY344864 or vehicle for 14days beginning 7days post-lesion. Tyrosine hydroxylase immunoreactivity (TH-ir) and MB were assessed in the brains of all groups following treatment, and locomotor activity was evaluated prior to lesioning, 7days post-lesion and after treatment. Key ResultsIncreased mitochondrial DNA content and nuclear- and mitochondrial-encoded mRNA and protein expression was observed in specific brain regions of LY344864-treated naive and lesioned mice, indicating augmented MB. LY344864 attenuated TH-ir loss in the striatum and substantia nigra compared to vehicle-treated lesioned animals. LY344864 treatment also increased locomotor activity in 6-hydroxydopamine lesioned mice, while vehicle treatment had no effect. Conclusions and ImplicationsThese data revealed that LY344864-induced MB attenuates dopaminergic neuron loss and improves behavioural endpoints in this model. We suggest that stimulating MB may be beneficial for the treatment of Parkinson's disease and that the 5-HT1F receptor may be an effective therapeutic target.
    • 53-43 Ma Deformation of Eastern Tibet Revealed by Three Stages of Tectonic Rotation in the Gongjue Basin

      Zhang, Yang; Huang, Wentao; Huang, Baochun; van Hinsbergen, Douwe J. J.; Yang, Tao; Dupont-Nivet, Guillaume; Guo, Zhaojie; Univ Arizona, Dept Geosci (AMER GEOPHYSICAL UNION, 2018-05)
      The Gongjue basin from the eastern Qiangtang terrane is located in the transition region where the regional structural lineation curves from east-west-oriented in Tibet to north-south-oriented in Yunnan. In this study, we sampled the red beds in the basin from the lower Gongjue to upper Ranmugou formations for the first time covering the entire stratigraphic profile. The stratigraphic ages are bracketed within 53-43Ma by new detrital zircon U-Pb ages constraining the maximum deposition age to 52.51.5Ma. Rock magnetic and petrographic studies indicate that detrital magnetite and hematite are the magnetic carriers. Positive reversals and fold tests demonstrate that the characteristic remanent magnetization has a primary origin. The Gongjue and Ranmugou formations yield mean characteristic remanent magnetization directions of D-s/I-s=31.0 degrees/21.3 degrees and D-s/I-s=15.9 degrees/22.0 degrees, respectively. The magnetic inclination of these characteristic remanent magnetizations is significantly shallowed compared to the expected inclination for the locality. However, the elongation/inclination correction method does not provide a meaningful correction, likely because of syn-depositional rotation. Rotations relative to the Eurasian apparent polar wander path occurred in three stages: Stage I, 33.33.4 degrees clockwise rotation during the deposition of the Gongjue and lower Ranmugou formations; Stage II, 26.93.7 degrees counterclockwise rotation during deposition of the lower and middle Ranmugou formation; and Stage III, 17.73.3 degrees clockwise rotation after 43Ma. The complex rotation history recorded in the basin is possibly linked to sinistral shear along the Qiangtang block during India indentation into Asia and the early stage of the extrusion of the northwestern Indochina blocks away from eastern Tibet.
    • 6&6: A Transdisciplinary Approach to Art–Science Collaboration

      Clark, Sarah E; Magrane, Eric; Baumgartner, Thomas; Bennett, Scott E K; Bogan, Michael; Edwards, Taylor; Dimmitt, Mark A; Green, Heather; Hedgcock, Charles; Johnson, Benjamin M; et al. (OXFORD UNIV PRESS, 2020-07-29)
      Despite an historical connection between the arts and sciences, in the past century, the two disciplines have been greatly siloed. However, there is a renewed interest in collaboration across the arts and sciences to support conservation practice by understanding and communicating complex environmental, social, and cultural challenges in novel ways. 6&6 was created as a transdisciplinary art-science initiative to promote a deeper appreciation of the Sonoran Desert. Six artists and six scientists were paired to create work that explored conservation issues in the Sonoran Desert and the Gulf of California. In-depth interviews were conducted with the artists and scientists throughout the 4-year initiative to understand the impact of 6&6 on their personal and professional behaviors and outlook. The findings from this case study reveal the role that intensive, place-based, and transdisciplinary art-science programs can play in shaping narratives to better communicate the patterns and processes of nature and human-environment interactions.
    • The 6.5-m MMT Telescope: status and plans for the future

      Williams, G. Grant; Ortiz, R.; Goble, W.; Gibson, J. D.; Univ Arizona, MMT Observ; MMT Observatory (United States); MMT Observatory (United States); MMT Observatory (United States); MMT Observatory (United States) (SPIE-INT SOC OPTICAL ENGINEERING, 2016-08-08)
      The MMT Observatory, a joint venture of the Smithsonian Institution and the University of Arizona, operates the 6.5-m MMT telescope on the summit of Mount Hopkins approximately 45 miles south of Tucson, AZ. The upgraded telescope has been in routine operation for nearly fifteen years and, as such, is a very reliable and productive general purpose astronomical instrument. The telescope can be configured with one of three secondary mirrors that feed more than ten instruments at the Cassegrain focus. In this paper we provide an overview of the telescope, its current capabilities, and its performance. We will review the existing suite of instruments and their different modes of operation. We will describe some of the general operations challenges and strategies for the Observatory. Finally, we will discuss plans for the near-term future including technical upgrades, new instrumentation and routine queue operation of MMIRS and Binospec.
    • 6.5  m telescope for multi-object spectroscopy over a 3° field of view

      Eads, Ryker; Angel, Roger; Univ Arizona, Wyant Coll Opt Sci; Univ Arizona, Steward Observ (OPTICAL SOC AMER, 2020-08-01)
      Multi-object spectroscopy via independently positioned optical fibers is of growing importance in many research areas in astronomy. Currently the most powerful instrument of this type is the Dark Energy Spectroscopic Instrument (DESI), now being commissioned at the 3.8 m Mayall telescope. It has a 3.2° field of view where spectra of 5000 different objects may be recorded simultaneously. Here we present an optical design for a two-mirror 6.5 m telescope with 3.0° field of view, for an etendue 2.6 times larger than for DESI. The images are at f/3.7 for fiber matching, and -averaged over the field and elevations down to 40°-have a diameter of 0.53 arcsec for 80% encircled energy. We outline methods capable of polishing and testing the 1.56 m diameter gull-wing lens of the wide field corrector. If a 2 m diameter lens could be made, the same design could be scaled up to an 8.4 m primary for a 4.3-fold etendue advantage.