Charge density mismatch synthesis of zeolite beta in the presence of tetraethylammonium, tetramethylammonium, and sodium ions: Influence of tetraethylammonium decomposition

Park, Min Bum,Ahn, Sang Hyun,Nicholas, Christopher P.,Lewis, Gregory J.,Hong, Suk Bong Elsevier 2017 Microporous and mesoporous materials Vol.240 No.-

<P><B>Abstract</B></P> <P>The effects of a temperature change on the phase selectivity of crystallization in a tetraethylammonium (TEA<SUP>+</SUP>)-tetramethylammonium (TMA<SUP>+</SUP>)-Na<SUP> <B>+</B> </SUP> mixed structure-directing agent (SDA) system, which had been previously used in the synthesis of UZM-9 and UZM-5 at 100 and 150 °C, respectively, have been further investigated in order to shed more light on the course of charge density mismatch (CDM) syntheses of aluminosilicate zeolites. Nanocrystalline zeolite beta with a Si/Al ratio of 8.1, essentially the same ratio as that (8.0) of its initial synthesis mixture, was the phase crystallized at 155 °C, whereas heating at higher temperatures ranging from 160 to 200 °C for up to 21 days gave no crystalline products. The course of chemistry at these temperatures is highly influenced by the increasing instability of the TEA<SUP>+</SUP> SDA. The overall results of this study demonstrate that the TMA<SUP>+</SUP>, as well as the TEA<SUP>+</SUP> and Na<SUP> <B>+</B> </SUP> ions, plays an important role in the nucleation step of zeolite beta prepared here, providing another example of SDA cooperation in a CDM zeolite synthesis. An idealized charge density disproportionation model is employed to track the evolving chemistry of the aluminosilicate solids and solutions. The discrepancy between the observed solution chemistry and that expected by the model suggests the presence of undesirable reactions in the system, namely TEA<SUP>+</SUP> decomposition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanocrystalline zeolite beta was synthesized at 155 °C in the TEA<SUP>+</SUP>-TMA<SUP>+</SUP>-Na<SUP>+</SUP> SDA system. </LI> <LI> Instability of the CDM SDA TEA<SUP>+</SUP> dominates zeolite beta synthesis. </LI> <LI> TMA<SUP>+</SUP> plays an important role in the nucleation stage of zeolite beta. </LI> <LI> The crystallization of zeolite beta is another new example of CDM zeolite syntheses. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The VISTA Deep Extragalactic Observations (VIDEO) survey★

Jarvis, Matt J.,Bonfield, D. G.,Bruce, V. A.,Geach, J. E.,McAlpine, K.,McLure, R. J.,Gonzá,lez-Solares, E.,Irwin, M.,Lewis, J.,Yoldas, A. Kupcu,Andreon, S.,Cross, N. J. G.,Emerson, J. P.,Dalton, Oxford University Press 2013 Monthly notices of the Royal Astronomical Society Vol.428 No.2

Artist friendly facial animation retargeting

Seol, Yeongho,Seo, Jaewoo,Kim, Paul Hyunjin,Lewis, J. P.,Noh, Junyong Association for Computing Machinery 2011 ACM transactions on graphics Vol.30 No.6

<P>This paper presents a novel facial animation retargeting system that is carefully designed to support the animator's workflow. Observation and analysis of the animators' often preferred process of key-frame animation with blendshape models informed our research. Our retargeting system generates a similar set of blendshape weights to those that would have been produced by an animator. This is achieved by rearranging the group of blendshapes into several sequential retargeting groups and solving using a matching pursuit-like scheme inspired by a traditional key-framing approach. Meanwhile, animators typically spend a tremendous amount of time simplifying the dense weight graphs created by the retargeting. Our graph simplification technique effectively produces editable weight graphs while preserving the visual characteristics of the original retargeting. Finally, we automatically create GUI controllers to help artists perform key-framing and editing very efficiently. The set of proposed techniques greatly reduce the time and effort required by animators to achieve high quality retargeted facial animations.</P>

Formation Pathway for LTA Zeolite Crystals Synthesized via a Charge Density Mismatch Approach

Park, Min Bum,Lee, Yoorim,Zheng, Anmin,Xiao, Feng-Shou,Nicholas, Christopher P.,Lewis, Gregory J.,Hong, Suk Bong American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.6

<P>A solid understanding of the molecular-level mechanisms responsible for zeolite crystallization remains one of the most challenging issues in modern zeolite science. Here we investigated the formation pathway for high-silica LTA zeolite crystals in the simultaneous presence of tetraethylammonium (TEA<SUP>+</SUP>), tetramethylammonium (TMA<SUP>+</SUP>), and Na<SUP>+</SUP> ions as structure-directing agents (SDAs) with the goal of better understanding the charge density mismatch synthesis approach, which was designed to foster cooperation between two or more different SDAs. Nucleation was found to begin with the formation of <I>lta</I>-cages rather than the notably smaller <I>sod</I> and <I>d4r</I>-cages, with concomitant incorporation of TMA<SUP>+</SUP> and Na<SUP>+</SUP> into a very small amount of the solid phase with a low Si/Al ratio (ca. 2.5). The overall characterization results of our work demonstrate that <I>sod</I>-cages are first built around the preorganized <I>lta</I>-cages and that <I>d4r</I>-cages are in turn constructed by the progressive addition of low-molecular-weight (alumino)silicate species, which promotes the formation and growth of embryonic LTA zeolite crystals. We also show that the crystal growth may take place by a similar process in which TEA<SUP>+</SUP> is also incorporated, forming a single LTA zeolite phase with a higher Si/Al ratio (ca. 3.3).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-6/ja309831e/production/images/medium/ja-2012-09831e_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja309831e'>ACS Electronic Supporting Info</A></P>

Compression and direct manipulation of complex blendshape models

Seo, Jaewoo,Irving, Geoffrey,Lewis, J. P.,Noh, Junyong Association for Computing Machinery 2011 ACM transactions on graphics Vol.30 No.6

<P>We present a method to compress complex blendshape models and thereby enable interactive, hardware-accelerated animation of these models. Facial blendshape models in production are typically large in terms of both the resolution of the model and the number of target shapes. They are represented by a single huge blendshape matrix, whose size presents a storage burden and prevents real-time processing. To address this problem, we present a new matrix compression scheme based on a hierarchically semi-separable (HSS) representation with matrix block reordering. The compressed data are also suitable for parallel processing. An efficient GPU implementation provides very fast feedback of the resulting animation. Compared with the original data, our technique leads to a huge improvement in both storage and processing efficiency without incurring any visual artifacts. As an application, we introduce an extended version of the direct manipulation method to control a large number of facial blendshapes efficiently and intuitively.</P>

Crystallization Mechanism of Zeolite UZM-5

Park, Min Bum,Ahn, Nak Ho,Broach, Robert W.,Nicholas, Christopher P.,Lewis, Gregory J.,Hong, Suk Bong American Chemical Society 2015 Chemistry of materials Vol.27 No.5

<P>A reliable formation pathway for UZM-5 zeolite crystals in the presence of tetraethylammonium, tetramethylammonium, and Na<SUP>+</SUP> ions at 150 °C has been proposed based on the <SUP>13</SUP>C MAS NMR and IR spectra of a series of solid products recovered as a function of time during the crystallization process, as well as on the crystal structure of as-made UZM-5 determined using synchrotron powder X-ray diffraction and Rietveld analyses. The nucleation of this cage-based small-pore zeolite begins with the construction of the largest 26-hedral <I>lta</I>-cages among its four different structural units. The next step is the attachment of 14-hedral <I>wbc</I>-cages to the preorganized <I>lta</I>-cage at shared 6-rings in an appropriate orientation that will allow the growth of two <I>wbc</I>-cage layers linked by 8-hedral <I>rth</I>-cage formation along both <I>a</I> and <I>b</I> axes. The resulting interlayer space is readily converted to a layer of <I>lta</I>-cages by interconnecting two opposing <I>wbc</I>-cages, with the concomitant formation of interlayer <I>d4r</I>-cages and 8-rings. Over the outer surface of the resulting UZM-5 nuclei, which resembles one-half of an <I>lta</I>-cage, the crystal growth may take place in a self-assembled manner as described above.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2015/cmatex.2015.27.issue-5/cm504079m/production/images/medium/cm-2014-04079m_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm504079m'>ACS Electronic Supporting Info</A></P>

The Brassica/Arabidopsis Comparative Genome Browser A Novel Approach to Genome Browsing

Lewis Christopher T.,Sharpe Andrew G.,Lydiate Derek J.,Parkin Isobel A.P. The Korean Society of Plant Biotechnology 2003 Plant molecular biology and biotechnology research Vol.5 No.4

Scalable Vector Graphics (SVG) has enabled a visually appealing, browser-based application for the display of Brassica sequences relative to Arabidopsis thaliana, and there are currently more than 70,000 B. napus Expressed Sequence Tags (ESTs) displayed. The client side of this browser is based on a Custom Graphical User Interface (CGUI) library which uses SVG, a new web graphics standard, to provide windowing functionality inside the web browser. This windowing functionality, combined with asynchronous data retrieval and client side rendering overcomes two of the key technology imposed drawbacks of current web based browsers: Fixed displays and frequent page reloads. The end result is an intuitive and enjoyable browsing experience. The browser is accessible online from the Brassica / Arabidopsis Genomics Initiative (http://brassica.agr.gc.ca). Inquiries about the browser should be directed to LewisCT@agr.gc.ca.

SketchiMo : sketch-based motion editing for articulated characters

Choi, Byungkuk,i Ribera, Roger Blanco,Lewis, J. P.,Seol, Yeongho,Hong, Seokpyo,Eom, Haegwang,Jung, Sunjin,Noh, Junyong Association for Computing Machinery 2016 ACM transactions on graphics Vol.35 No.4

<P>We present SketchiMo, a novel approach for the expressive editing of articulated character motion. SketchiMo solves for the motion given a set of projective constraints that relate the sketch inputs to the unknown 3 D poses. We introduce the concept of sketch space, a contextual geometric representation of sketch targets -motion properties that are editable via sketch input-that enhances, right on the viewport, different aspects of the motion. The combination of the proposed sketch targets and space allows for seamless editing of a wide range of properties, from simple joint trajectories to local parent-child spatiotemporal relationships and more abstract properties such as coordinated motions. This is made possible by interpreting the user's input through a new sketch-based optimization engine in a uniform way. In addition, our view-dependent sketch space also serves the purpose of disambiguating the user inputs by visualizing their range of effect and transparently defining the necessary constraints to set the temporal boundaries for the optimization.</P>

Zeolite Synthesis from a Charge Density Perspective: The Charge Density Mismatch Synthesis of UZM-5 and UZM-9

Park, Min Bum,Jo, Donghui,Jeon, Him Chan,Nicholas, Christopher P.,Lewis, Gregory J.,Hong, Suk Bong American Chemical Society 2014 Chemistry of materials Vol.26 No.23

<P>A charge density model of aluminosilicate zeolite synthesis is presented. This model has been applied to the charge density mismatch (CDM) synthesis of UZM-5 and UZM-9 zeolites at 150 and 100 °C, respectively, using the same synthesis mixture that includes tetraethylammonium (TEA<SUP>+</SUP>), tetramethylammonium (TMA<SUP>+</SUP>), and Na<SUP>+</SUP> ions as structure-directing agents (SDAs). It allows a seamless description of the contributions of both the hydroxide and SDA components of the CDM barrier to zeolite synthesis. The syntheses are described as temperature-driven confrontations with the CDM barrier, resulting in disproportionation to solution and solid products with diverging charge densities. The presence of the CDM barrier and this tunable disproportionation in charge density, along with the suitable choice of SDA concentrations, allows a flexible and cooperative participation of SDAs, as the synthesis medium initially forms aluminosilicate networks that maximize Coulombic stabilization under the conditions at hand. The UZM-5 synthesis at 150 °C is characterized by much higher fractional Si and Al yields (0.85 Si and 0.94 Al vs 0.30 Si and 0.70 Al) and a higher Si/Al ratio (ca. 7 vs 3) compared to UZM-9 synthesis at 100 °C. Unlike the latter case, TEA<SUP>+</SUP> plays an important role in the nucleation of UZM-5. However, TMA<SUP>+</SUP> was found to be essential for the nucleation of both zeolites. While Na<SUP>+</SUP> is required to crystallize UZM-9, the nucleation rate of UZM-5 is about twice as fast in the absence of Na<SUP>+</SUP>. On the other hand, the crystal growth rate of this small-pore zeolite is over 10 times faster with Na<SUP>+</SUP> present, giving a considerably larger crystallite size.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-23/cm501919d/production/images/medium/cm-2014-01919d_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm501919d'>ACS Electronic Supporting Info</A></P>

Facial retargeting with automatic range of motion alignment

Ribera, Roger Blanco i,Zell, Eduard,Lewis, J. P.,Noh, Junyong,Botsch, Mario Association for Computing Machinery 2017 ACM transactions on graphics Vol.36 No.4