402 research outputs found

    Artful Identifications: Crafting Survival in Japanese American Concentration Camps

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    "Artful Identifications" offers three meanings of internment art. First, internees remade locations of imprisonment into livable places of survival. Inside places were remade as internees responded to degraded living conditions by creating furniture with discarded apple crates, cardboard, tree branches and stumps, scrap pieces of wood left behind by government carpenters, and wood lifted from guarded lumber piles. Having addressed the material conditions of their living units, internees turned their attention to aesthetic matters by creating needle crafts, wood carvings, ikebana, paintings, shell art, and kobu. Dramatic changes to outside spaces of "assembly centers" and concentration camps were also critical to altering hostile settings into survivable landscapes. My second meaning positions art as a means of making connections, a framework offered with the hope of escaping utopian models of community building which overemphasize the development of common beliefs, ideas, and practices that unify people into easily surveilled groups. "Making Connections" situates the process of individuals identifying with larger collectivities in the details of everyday life, a complicated and layered process that often remains invisible to us. By sewing clothes for each other, creating artificial flowers and lapel pins as gifts, and participating in classes and exhibits, internees addressed their needs for maintaining and developing connections. "Making Connections" advances perhaps the broadest possible understanding of identity formation based on the idea of employing diverse art forms to sustain already developed relationships and creating new attachments in the context of displacement. The third meaning offered by this project is art as a mental space of survival. In the process of crafting, internees pieced together mental landscapes that allowed them to generate new ideas and alternative discourses. As recent psychoanalytic scholarship suggests, these artful identifications with loss encompassed radical political possibilities because they keep melancholic struggles alive and relevant to the present. Regardless of whether we understand these crafting examples as tools for remaking inside places, re-territorializing outside spaces, making connections, or artifacts of loss, it is clear that for Japanese Americans incarcerated in complex places of oppression, art evolved into portables spaces of resistance

    CIT-9: a fault-free, gmelinite zeolite

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    A synthetic, fault-free gmelinite (GME) zeolite is prepared using a specific organic structure-directing agent (OSDA), cis-3,5-dimethylpiperidinium. The cis-isomers align in the main 12-membered ring (MR) channel of GME. Trans-isomer OSDA leads to the small-pore zeolite SSZ-39 with the OSDA in its cages. Data from N_2-physisorption and rotation electron diffraction provide evidence for the openness of the 12 MR channel in the GME 12×8×8 pore architecture and the absence of stacking faults, respectively. CIT-9 is hydrothermally stable when K^+-exchanged, while in the absence of exchange, the material transforms into an aluminous AFI-zeolite. The process of this phase-change was followed by in situ variable temperature powder X-ray diffraction. CIT-9 has the highest Si/Al ratio reported for GME, and along with its good porosity, opens the possibility of using GME in a variety of applications including catalysis

    Shape-selective zeolite catalysis for bioplastics production

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    Biodegradable and renewable polymers, such as polylactic acid, are benign alternatives for petrochemical-based plastics. Current production of polylactic acid via its key building block lactide, the cyclic dimer of lactic acid, is inefficient in terms of energy, time, and feedstock use. We present a direct zeolite-based catalytic process, which converts lactic acid into lactide. The shape-selective properties of zeolites are essential to attain record lactide yields, outperforming those of the current multistep process by avoiding both racemization and side-product formation. The highly productive process is strengthened by facile recovery and practical reactivation of the catalyst, which remains structurally fit during at least six consecutive reactions, and by the ease of solvent and side-product recycling

    Influence of Organic Structure Directing Agent Isomer Distribution on the Synthesis of SSZ-39

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    The aluminosilicate molecular sieve with the AEI framework topology (SSZ-39) is currently of great interest for use in a number of important applications such as exhaust gas NO_x reduction and the methanol-to-olefins reaction. It is likely that advances in the synthesis of this molecular sieve will be needed for applications to proceed. Here, dimethylpiperidine based organic structure directing agents (OSDAs) are used to prepare SSZ-39, and the influence of diastereo- and structural isomeric mixtures on the synthesis of SSZ-39 is reported. Although differences in the rates of molecular sieve formation as well as preferential isomer incorporation occur, the synthesis of SSZ-39 is possible over a wide range of isomeric mixtures. These findings demonstrate that the synthesis of SSZ-39 can be accomplished with OSDA isomer mixtures that naturally occur from the synthesis of the organic precursors used to prepare the OSDAs

    Direct catalytic conversion of cellulose to liquid straight-chain alkanes

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    High yields of liquid straight-chain alkanes were obtained directly from cellulosic feedstock in a one-pot biphasic catalytic system. The catalytic reaction proceeds at elevated temperatures under hydrogen pressure in the presence of tungstosilicic acid, dissolved in the aqueous phase, and modified Ru/C, suspended in the organic phase. Tungstosilicic acid is primarily responsible for cellulose hydrolysis and dehydration steps, while the modified Ru/C selectively hydrogenates intermediates en route to the liquid alkanes. Under optimal conditions, microcrystalline cellulose is converted to 82% n-decane-soluble products, mainly n-hexane, within a few hours, with a minimum formation of gaseous and char products. The dominant route to the liquid alkanes proceeds via 5-hydroxymethylfurfural (HMF), whereas the more common pathway via sorbitol appears to be less efficient. High liquid alkane yields were possible through (i) selective conversion of cellulose to glucose and further to HMF by gradually heating the reactor, (ii) a proper hydrothermal modification of commercial Ru/C to tune its chemoselectivity to furan hydrogenation rather than glucose hydrogenation, and (iii) the use of a biphasic reaction system with optimal partitioning of the intermediates and catalytic reactions. The catalytic system is capable of converting subsequent batches of fresh cellulose, enabling accumulation of the liquid alkanes in the organic phase during subsequent runs. Its robustness is illustrated in the conversion of the raw (soft)wood sawdust

    Synthesis–Structure–Activity Relations in Fe-CHA for C–H Activation: Control of Al Distribution by Interzeolite Conversion

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    The search for structurally relevant Al-arrangements in zeolites is an important endeavor for single site catalysis. Little is known about the mechanisms and zeolite dynamics during synthesis that are responsible for creating those Al-ensembles. Here, new synthetic strategies for creating Al-hosts in small-pore zeolites suitable for divalent cation catalysis are uncovered, leading to a mechanistic proposal for Al-organization during crystallization. As such, unique synthesis-structure-activity relations are demonstrated for the partial oxidation of methane on Fe-exchanged CHA-zeolites. With modified interzeolite conversions, the divalent cation capacity of the resulting high Si SSZ-13 zeolites (Si/Al ~ 35) can be reproducibly controlled in a range between 0.04 and 0.34 CoÂČâș/Al. This capacity is a proxy for the distribution of framework aluminum in pairs and correlates with the methanol production per Al when these zeolites host the α-Fe^(II) redox active site. The uncovered IZC synthesis-structure relations paint an Al-distribution hypothesis, where incongruent dissolution of the starting USY zeolite and fast synthesis kinetics with atypical growth modes allow assembling specific Al-arrangements, resulting in a high divalent cation capacity. Prolonged synthesis times and high temperatures overcome the energetic barriers for T-atom reshuffling favoring Al-isolation. These mechanisms and the relations uncovered in this work will guide the search for relevant Al-ensembles in a range of zeolite catalysts where controlling the environment for a single active site is crucial

    CIT-9: a fault-free, gmelinite zeolite

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    A synthetic, fault-free gmelinite (GME) zeolite is prepared using a specific organic structure-directing agent (OSDA), cis-3,5-dimethylpiperidinium. The cis-isomers align in the main 12-membered ring (MR) channel of GME. Trans-isomer OSDA leads to the small-pore zeolite SSZ-39 with the OSDA in its cages. Data from N_2-physisorption and rotation electron diffraction provide evidence for the openness of the 12 MR channel in the GME 12×8×8 pore architecture and the absence of stacking faults, respectively. CIT-9 is hydrothermally stable when K^+-exchanged, while in the absence of exchange, the material transforms into an aluminous AFI-zeolite. The process of this phase-change was followed by in situ variable temperature powder X-ray diffraction. CIT-9 has the highest Si/Al ratio reported for GME, and along with its good porosity, opens the possibility of using GME in a variety of applications including catalysis

    Shape-selective zeolite catalysis for bioplastics production

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