Now showing items 1-20 of 75819

    • Data Products and Data Product Description- Thermal Analysis

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- TAGSAM Telemetry

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- Spectral Analysis

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- Spacecraft’

      OSIRIS-REx Asteroid Sample Return Mission (2016)
    • Data Products and Data Product Description- Sample Site Science

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- Sample Return Capsule

      OSIRIS-REx Asteroid Sample Return Mission (2013)
    • Data Products and Data Product Description- Regolith Development

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- Radio Science

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description- Image Processing

      OSIRIS-REx Asteroid Sample Return Mission (2018)
    • Data Products and Data Product Description-Dynamical Evolution

      OSIRIS-REx Asteroid Sample Return Mission (2013)
    • Data Products and Data Product Description- Carbonaceous Meteorites

      OSIRIS-REx Asteroid Sample Return Mission (2016)
    • Data Products and Data Product Description- Astrometry and Photometry

      OSIRIS-REx Asteroid Sample Return Mission (2017)
    • Data Products and Data Product Description- Asteroid Astrometry

      OSIRIS-REx Asteroid Sample Return Mission (2017)
    • Data Products and Data Product Description- Altimetry

      OSIRIS-REx Asteroid Sample Return Mission (2017)
    • Data Products and Data Product Description- Table of Contents

      OSIRIS-REx Asteroid Sample Return Mission (2019)
    • Request New Data Product

      OSIRIS-REx Asteroid Sample Return Mission (2014)
    • Level 2 and Automated L3 Approval Process

      OSIRIS-REx Asteroid Sample Return Mission (2017)
    • Development of New Organic Photoredox Catalysis Driven by Visible Light

      Wang, Wei; Zhang, Yueteng; Wondrak, Georg T.; Hulme, Christopher; Njardarson, Jon T. (The University of Arizona., 2020)
      Development of efficient and sustainable synthetic technologies for molecular construction is the central goal in modern organic synthesis. In recent decades, organocatalysis has become one of the viable tools in organic synthesis with notable features including easy manipulation, low cost, and/or less susceptible to air and moisture. Organophotoredox catalysis has merged as a front runner in organocatalysis. My Ph.D. study focuses on the development of novel visible-light mediated organic photoredox catalysis strategies for the construction of structurally diverse molecular architectures in distinct ways. In the first efforts, a metal- and oxidant-free organophotocatalytic method for preparing structurally diverse thioesters from readily accessible, abundant aldehydes, has been realized. Excited by blue light, the simple and cost-effective 9,10-phenanthrenequinone (PQ) promotes hydrogen atom transfer (HAT) to selectively generate acyl radicals from corresponding aldehydes without inducing crossover reactivity of thioesters. In situ formed acyl radicals then react with thiosulfonate S-esters to efficiently produce thioesters. The mild and efficient method exhibits excellent substrate scope and outstanding functional group tolerance. Significantly, it is proved to be useful in a late-stage functionalization of complex molecules. Direct H/D exchange at formyl groups represents the most straightforward approach to C-1 deuterated aldehydes. Along this line, a new photoredox catalytic, visible-light mediated neutral radical approach has been developed via a unique double-HAT process. Selective control of highly reactive acyl radical enables driving the formation of deuterated products when an excess of D2O is employed. The power of H/D exchange process has been demonstrated for both aromatic aldehydes and aliphatic substrates, and more important late-stage deuterium incorporation into complex structures with uniformly high deuteration level (>90%). The direct dearomatization of indoles represents the most straightforward access to indolines. However, the exiting dearomative methods largely restrict to electron-rich indoles or go through an ionic process using strong nucleophiles. Toward this end, an unprecedented organophotocatalytic process by harnessing nucleophilic radicals to react with electron-deficient indoles was developed. The preparative power of this radical-engaged strategy has been demonstrated by direct addition of in situ formed nucleophilic radicals from readily accessible feedstock carboxylic acids, into structurally diverse electrophilic indoles including (thio)ester, amide, ketone, nitrile and thus delivering a series of trans-2,3-disubstituted indolines with uniformly high stereoselectivity (> 20:1 dr). Moreover, this approach has also been successfully applied to other aromatic heterocycles such as pyrroles, benzofurans and benzothiophenes.
    • After Compatibilism: Essays on Freedom and Responsibility

      McKenna, Michael S.; Wallace, Robert Hamilton; Sartorio, Carolina; Timmons, Mark; Horgan, Terence; Nelkin, Dana K. (The University of Arizona., 2020)
      This dissertation is a series of standalone essays. Together, they form a critique of contemporary compatibilist approaches to the problem of free will and determinism, and they offer an alternative methodology for approaching questions about freedom and responsibility. Compatibilist approaches to the free will problem exist on a spectrum from the more normative to the more metaphysical. Views at the metaphysical end of the spectrum typically understand free will in terms of abilities. In Chapter 1, I argue that these views face a powerful dilemma: they either fail to explain these abilities or fail to show that these abilities are compatible with the thesis of physical determinism. Perhaps a commitment to abilities could be given up, but I argue that takes us too far afield from the intuitive way we understand ourselves as free agents. Compatibilist approaches at the normative end of the spectrum have been largely influenced by P.F. Strawson’s responsibility naturalism. Views of this sort begin by carefully attending to the features of our responsibility practices in order to glean the nature of the sort of freedom that grounds apt responsibility ascriptions. In Chapter 2, I defend a version of this view from a decisive objection: Strawsonian compatibilism seems to make evildoers exempt from moral responsibility. Nevertheless, in Chapter 3, I argue that Strawson's program cannot properly insulate itself from metaphysical concerns about abilities. The methodology may actually support a powerful form of incompatibilism about free will and determinism. This casts the entire contemporary project that draws on his work in a suspect light. Drawing lessons from these two failures, in Chapter 4, I offer a practice-based argument for realism about freedom and responsibility—the view that we really are free and responsible— that is neutral with respect to questions about the compatibility of freedom and determinism. The argument does not depend on any particular metaphysical theory of abilities or particular view of our moral practices. I argue in Chapter 5 that, given this realist framework, we have reason to think that whatever ends up being true about the abilities that characterize free and responsible agents, they will be compatible with determinism after all.