Hannah Ruth London papers, 1919-1990.

The collection consists primarily of research notes for Ms. London's published works on portraits, miniatures and silhouettes of American Jews. The notes contain family histories of the subjects as well as information on the artists, and are arranged both by subject and artist. The collection also contains published articles on the subject by London, and photographs and lantern slides of the artwork that have been removed to the picture collection.

Letter to K. K. S. I. from London

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Copy of letter of K. K. S. I. to London regarding selection of a hazan

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Copy of letter from Portuguese congregation, London, to K. K. S. I. regarding re-burial of dead

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Letter of trustees of Portuguese congregation, London, to K. K. S. I. regarding choosing a hazan for K. K. S. I.

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Letter from London regarding Haham Haim Mudahy

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Book Review: "Engin Isin and Evelyn Ruppert, Being Digital Citizens. London: Rowman & Littlefield, 2015"

The concept of digital citizenship has become increasingly important to our understanding of the relationship between media and political action, and the possibilities for democratization, decentralization, and diversification of power offered by the Internet. In the era of the digitalization of just about everything, citizenship and its related concepts are in processes of technology-driven transformation, with important implications for the global future of democratic culture. Isin and Ruppert’s book is a timely engagement with these questions, and with the emerging notion of the “digital subject.”

The Self-Association of Graphane Is Driven by London Dispersion and Enhanced Orbital Interactions

We investigated the nature of the cohesive energy between graphane sheets via multiple CH center dot center dot center dot HC interactions, using density functional theory (DFT) including dispersion correction (Grimmes D3 approach) computations of n]graphane sigma dimers (n = 6-73). For comparison, we also evaluated the binding between graphene sheets that display prototypical pi/pi interactions. The results were analyzed using the block-localized wave function (BLW) method, which is a variant of ab initio valence bond (VB) theory. BLW interprets the intermolecular interactions in terms of frozen interaction energy (Delta E-F) composed of electrostatic and Pauli repulsion interactions, polarization (Delta E-pol), charge-transfer interaction (Delta E-CT), and dispersion effects (Delta E-disp). The BLW analysis reveals that the cohesive energy between graphane sheets is dominated by two stabilizing effects, namely intermolecular London dispersion and two-way charge transfer energy due to the sigma CH -> sigma*(HC) interactions. The shift of the electron density around the nonpolar covalent C-H bonds involved in the intermolecular interaction decreases the C-H bond lengths uniformly by 0.001 angstrom. The Delta E-CT term, which accounts for similar to 15% of the total binding energy, results in the accumulation of electron density in the interface area between two layers. This accumulated electron density thus acts as an electronic glue for the graphane layers and constitutes an important driving force in the self-association and stability of graphane under ambient conditions. Similarly, the double faced adhesive tape style of charge transfer interactions was also observed among graphene sheets in which it accounts for similar to 18% of the total binding energy. The binding energy between graphane sheets is additive and can be expressed as a sum of CH center dot center dot center dot HC interactions, or as a function of the number of C-H bonds.