India

Banerjee, Syagnik; Lennon, Mark M.

doi:10.4018/9781591403159.ch008

Cited by 8 publications

(8 citation statements)

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“…The very low 12 C/ 13 C ratios (0.3-3) observed in novae are due to the 12 C(p, γ) 13 N(β + ) 13 C chain reaction during burning of the accreted hydrogen (José & Hernanz, 2007). These predictions of very low 12 C/ 13 C ratios are consistent with limits on the 12 C/ 13 C ratio estimated from fitting of 13 CO and 12 CO bands in the infrared spectra of several nova ejecta (Banerjee & Ashok, 2012;Banerjee et al 2016;Evans & Rawlings, 2008). Based on the composition of the WD core, we distinguish two types of novae: CO novae, for initial masses of the primary star below ~8 M , which undergo hydrogen and helium burning, leaving a carbonand oxygen-rich WD core; and ONe novae for slightly more massive stars (8-10 M ) which, in addition, undergo carbon burning, leaving an oxygen-and neon-rich WD core (José, 2016;José et al 2004).…”

Section: Lap-149: Extremely 13 C-rich Presolar Graphite From a Low-masupporting

confidence: 78%

Coordinated Analysis of Two Graphite Grains From the CO3.0 Lap 031117 Meteorite: First Identification of a Co Nova Graphite and a Presolar Iron Sulfide Subgrain

Haenecour

Floss

José

et al. 2016

ApJ

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Presolar grains constitute remnants of stars that existed before the formation of the solar system.In addition to providing direct information on the materials from which the solar system formed, these grains provide ground-truth information for models of stellar evolution and nucleosynthesis. Here we report the in-situ identification of two unique presolar graphite grains from the primitive meteorite LaPaz Icefield 031117. Based on these two graphite grains, we estimate a bulk presolar graphite abundance of 5 −3 +7 ppm in this meteorite. One of the grains (LAP-141) is characterized by an enrichment in 12 C and depletions in 33,34 S, and contains a small iron sulfide subgrain, representing the first unambiguous identification of presolar iron sulfide.The other grain (LAP-149) is extremely 13 C-rich and 15 N-poor, with one of the lowest 12 C/ 13 C ratios observed among presolar grains. Comparison of its isotopic compositions with new stellar nucleosynthesis and dust condensation models indicates an origin in the ejecta of a low-mass CO nova. Grain LAP-149 is the first putative nova grain that quantitatively best matches nova model predictions, providing the first strong evidence for graphite condensation in nova ejecta. Our discovery confirms that CO nova graphite and presolar iron sulfide contributed to the original building blocks of the solar system.

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Section: Lap-149: Extremely 13 C-rich Presolar Graphite From a Low-masupporting

confidence: 78%

Coordinated Analysis of Two Graphite Grains From the CO3.0 Lap 031117 Meteorite: First Identification of a Co Nova Graphite and a Presolar Iron Sulfide Subgrain

Haenecour

Floss

José

et al. 2016

ApJ

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“…[15] However,r elated umpolung transformations utilizing open-shell acyl radicals are still underdeveloped. [16] Until very recently,M elchiorre [16e] and Yu [16f] disclosed two ground-breaking work in which amine-catalyzed asymmetric additions to enals by acyl radicals were accomplished independently by combining with direct photoexcitation and photoredox catalysis.E ncouraged by our above success,w e planned to apply the same DCo5 complex to the visible-lightinduced asymmetric conjugated addition of enones by acyl radicals in the absence of additional photocatalyst. As highlighted in Figure 4, as eries of aryl-containing acyl radicals generated from corresponding HEs 8 can participate in this reaction, affording chiral 1,4-dicarbonyl products in good yields and enantioselectivities (9a-9g:94-> 99 %yields and up to 94:6 e.r.).…”

Section: Angewandte Chemiementioning

confidence: 99%

Exploration of a Chiral Cobalt Catalyst for Visible‐Light‐Induced Enantioselective Radical Conjugate Addition

Zhang

Jia

et al. 2019

Angewandte Chemie

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Chiral catalysts tolerating photochemical reactions are in great demand for the vast development of visible-lightinduced asymmetric synthesis.N ow,c hiral octahedral complexes based on earth-abundant metal and chiral N 4 ligands are reported. One well-defined chiral Co II -complex is shown to be an efficient catalyst in the visible-light-induced conjugated addition of enones by alkyl and acyl radicals,p roviding synthetically valued chiral ketones and 1,4-dicarbonyls in 47-> 99 %yields with up to 97:3 e.r.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

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“…In the literature, there are extremely insightful articles that offer an overview of the coherent oxide heterostructures from experimental and computational perspectives. [1][2][3]8,15,18,20,31,[47][48][49] Predominantly, there are several DFT-based computational studies in the literature that address what are presumably semi-coherent oxide interfaces in reality, but constrain them to be coherent. [32,[50][51][52][53][54][55][56] Forcing the two oxides to be coherent allows the implementation of smaller supercells to mimic the oxide heterostructures, which are tractable by DFT calculations.…”

Section: Introductionmentioning

confidence: 99%

Beyond Coherent Oxide Heterostructures: Atomic‐Scale Structure of Misfit Dislocations

Dholabhai

Uberuaga

2019

Advcd Theory and Sims

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Nanoscale design of complex oxide heterostructures and thin films is imperative as they have significant promise in novel technological applications. A coherent interface is formed in oxide heterostructures with small mismatches, and the lattice mismatch is completely compensated by elastic strain. In semi-coherent oxide heterostructures, when an epitaxial layer is grown on the substrate above the critical thickness of the film, misfit dislocations are formed to mitigate the strain between the two materials with dissimilar lattice constants. Key properties of semi-coherent oxide heterostructures are influenced or even controlled by the presence of misfit dislocations. Therefore, it is critical to understand the atomic-scale structure of semi-coherent oxide heterostructures, specifically the structure of misfit dislocations that are ubiquitous at such heterointerfaces. Numerous state-of-the-art experiments have reported emergent phenomena at semi-coherent oxide heterostructures, wherein misfit dislocations play a crucial role. However, their atomic-scale and nanoscale structure is not always discernable from experiments. Due to large system sizes, computational studies dedicated to examining misfit dislocations in semi-coherent oxide heterostructures are still in their infancy. This review aims to summarize the recent advancements and challenges involved in computational studies elucidating the atomic-scale structure of misfit dislocations in semi-coherent oxide heterostructures and motivate future computational efforts.

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India

Cited by 8 publications

References 0 publications

Coordinated Analysis of Two Graphite Grains From the CO3.0 Lap 031117 Meteorite: First Identification of a Co Nova Graphite and a Presolar Iron Sulfide Subgrain

Coordinated Analysis of Two Graphite Grains From the CO3.0 Lap 031117 Meteorite: First Identification of a Co Nova Graphite and a Presolar Iron Sulfide Subgrain

Exploration of a Chiral Cobalt Catalyst for Visible‐Light‐Induced Enantioselective Radical Conjugate Addition

Beyond Coherent Oxide Heterostructures: Atomic‐Scale Structure of Misfit Dislocations

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