The Three-Box Paradox Revisited

The classical three-box paradox of Kirkpatrick [J. Phys. A 36 4891 (2003)] is compared to the original quantum Three-Box paradox of Aharonov and Vaidman [J. Phys. A 24 2315 (1991)]. It is argued that the quantum Three-Box experiment is a "quantum paradox" in the sense that it is an example of a classical task which cannot be accomplished using classical means, but can be accomplished using quantum devices. It is shown that Kirkpatrick's card game is analogous to a different game with a particle in three boxes which does not contain paradoxical features.Comment: 13 pages, 4 figure

Pre- and post-selection, weak values, and contextuality

By analyzing the concept of contextuality (Bell-Kochen-Specker) in terms of pre-and-post-selection (PPS), it is possible to assign definite values to observables in a new and surprising way. Physical reasons are presented for restrictions on these assignments. When measurements are performed which do not disturb the pre- and post-selection (i.e. weak measurements), then novel experimental aspects of contextuality can be demonstrated including a proof that every PPS-paradox with definite predictions implies contextuality. Certain results of these measurements (eccentric weak values with e.g. negative values outside the spectrum), however, cannot be explained by a "classical-like" hidden variable theory.Comment: Identical content; stream-lined verbal presentatio

Engineering of coordination polymers for shape selective alkylation of large aromatics and the role of defects

Ravon, Ugo Savonnet, Marie Aguado, Sonia Domine, Marcelo E. Janneau, Erwann Farrusseng, David 1st International Conference on Metal-Organic Frameworks and Open Framework Compounds (MOFO8) OCT 08-10, 2008 Augsburg, GERMANY Sp. Iss. SIFor economic and environmental reasons, there is a strong incentive to replace of homogeneous by green and efficient heterogeneous processes in catalysis. The Friedel-Crafts alkylation of aromatics is a marking example. Numbers of homogeneous catalysts (such as HF, H2SO3, and AlCl3) have been replaced by H-form zeolites. However, large pore zeolite can not accommodate bulk aromatic molecules and/or alkylating agents avoiding the reaction to take place within the porous network. Due to their larger pore size. metal-organic frameworks (MOFs) open the doors to the alkylation of very large poly-aromatic compounds. We report different approaches for the design of acid shape selective MOFs. The first refers to a "zeolite mimetic" approach. It deals with the design of porous Zn or Al based MOF exhibiting bridging -OH species (MOF-69, MIL-53 Al) like those found in zeolites [Si-O(H)-Al]. The second approach aims at synthesizing MOF materials having structural defects to generate active catalytic centers. Two different synthetic strategies were investigated, either by fast precipitation or by the partial Substitution of dicarboxylic by mono-carboxylic acid linkers. Acid centers have been characterized by solid H-1 NMR and Diffuse Reflectance IR. The mono-alkylation of biphenyl with tert-BuCl is achieved with 100% of para-selectivity, well superior to H-MOR and H-BEA reference zeolites. (C) 2009 Elsevier Inc. All rights reserved

Natural gas treating by selective adsorption: Material science and chemical engineering interplay

Tagliabue, Marco Farrusseng, David Valencia, Susana Aguado, Sonia Ravon, Ugo Rizzo, Caterina Corma, Avelino Mirodatos, ClaudeThe paper addresses current needs in Natural Gas (NG) treating. Basic principles of Pressure Swing Adsorption (PSA) separation processes are described. A state of the art of microporous adsorbents in the frame of NG treating is given. It includes reference and advanced zeolites, carbon based materials and Metal-Organic Frameworks (MOFs). The pros and cons of each material category are discussed. Guidelines to develop on-purpose materials are given from thermodynamics and material state of the art. Finally, PSA applicability to inert (nitrogen and carbon dioxide) rejection from NG is discussed. (C) 2009 Elsevier B. V. All rights reserved

Combinatorial Synthesis and Characterization of Metal-Open Frameworks in Mild and Friendly Conditions: Application to CO2 Adsorption

MATERIAUX:INGENIERIE+URA:SAG:JPA:GBR:DFACombinatorial screening using precipitation methods at room temperature can lead to a great diversity of carboxylate based Metal Organic Frameworks (MOFs) including already known or original porous solids. The investigation of the synthesis of MOFs in different solvent and solvent mixtures includes the use of solvents such as alcohols and tetrahydrofuran (THF) which would greatly facilitate large scale production. We also show the application of Principal Component Analysis (PCA) and clustering techniques on large libraries of XRD diffraction files in order to identify classes of similar phases and peculiar phases. The combinatorial screening of 105 samples in the La/btc system has led to the identification of two phases which are solvent depending. On the La(btc) compound, the CO2 adsorption measurements reveal a guest-host interactions as supported by XRD phase transformation upon thermal treatment. The mass transport can be assigned to a "single file diffusion" regime due to the one dimensional channel porous structure associated to small pore size

Investigation of Acid Centers in MIL-53(Al, Ga) for Bronsted-Type Catalysis: In Situ FTIR and Ab Initio Molecular Modeling

Ravon, Ugo Chaplais, Gerald Chizallet, Celine Seyyedi, Behnam Bonino, Francesca Bordiga, Silvia Bats, Nicolas Farrusseng, DavidInternational audienc

Exploring Ice Age Island: Eight years of Early Prehistoric Research in the Channel Island of Jersey

International audienc