Crack Bridging Mechanism for Glass Strengthening by Organosilane Water-Based Coatings

We used an epoxysilane/aminosilane coating deposited from an aqueous solution to strengthen flat glass. We studied film formation, interfacial and mechanical properties of the film. The film is highly cross-linked with a 6 GPa Young's modulus and good adhesion. Our results suggest that crack face bridging accounts for most of the 75 % reinforcement in this system

Origin of the Parry arc

Laboratory experiments to determine the preferred orientation of free-falling hexagonal prisms were performed at Reynolds numbers appropriate to falling ice crystals in the atmosphere. Hexagonal plates orient with their c axis vertical for aspect ratios < 0.9, whilst hexagonal columns fall with their c axis horizontal. A secondary alignment is also observed: regular hexagonal columns fall preferentially with two prism facets aligned vertically and not horizontally – the latter scenario was previously assumed to be responsible for the rare Parry arc. However, if the column is made scalene in its cross-section, it can orient such that a pair of prism facets is horizontal. This finding indicates that the development of scalene crystals may be key to the production of certain ice-crystal optical phenomen

Target Mass Monitoring and Instrumentation in the Daya Bay Antineutrino Detectors

The Daya Bay experiment measures sin^2 2{\theta}_13 using functionally identical antineutrino detectors located at distances of 300 to 2000 meters from the Daya Bay nuclear power complex. Each detector consists of three nested fluid volumes surrounded by photomultiplier tubes. These volumes are coupled to overflow tanks on top of the detector to allow for thermal expansion of the liquid. Antineutrinos are detected through the inverse beta decay reaction on the proton-rich scintillator target. A precise and continuous measurement of the detector's central target mass is achieved by monitoring the the fluid level in the overflow tanks with cameras and ultrasonic and capacitive sensors. In addition, the monitoring system records detector temperature and levelness at multiple positions. This monitoring information allows the precise determination of the detectors' effective number of target protons during data taking. We present the design, calibration, installation and in-situ tests of the Daya Bay real-time antineutrino detector monitoring sensors and readout electronics.Comment: 22 pages, 20 figures; accepted by JINST. Changes in v2: minor revisions to incorporate editorial feedback from JINS

Surface Grafting of Poly(L-glutamates). 2. Helix Orientation

In this paper the average helix orientation of surface-grafted poly(γ-benzyl L-glutamate) (PBLG), poly(γ-methyl L-glutamate) (PMLG), and poly(γ-methyl L-glutamate)-co-(γ-n-stearyl L-glutamate) (PMLGSLG 70/30) was investigated by means of FT-IR transmission spectroscopy. The theoretical relation between the average tilt angle (θ) and the absorption peak areas of three different backbone amide bands could be calculated because their transition dipole moment directions with respect to the helix axis were known. From the normalized absorptions, the average tilt angles of grafted helices of PBLG, PMLG, and PMLGSLG 70/30 were determined. The somewhat larger average angle of PMLG helices of 35 ± 5° with respect to the substrate compared to the value of 32 ± 5° of PBLG was due to the higher grafting density of PMLG. Because of the smaller helix diameter as a result of the smaller size of the methyl side group, more PMLG helices grew on the same surface area. Sterical hindrance and unfavorable polar interactions between unidirectional aligned helices forced the PMLG helices in a more upright arrangement. The even more perpendicular orientation of PMLGSLG 70/30 (48 ± 6°) could be the result of incorporation of mainly γ-methyl L-glutamate N-carboxyanhydride (MLG-NCA) monomers during the initiation step. Incorporation of the much larger γ-n-stearyl L-glutamate N-carboxyanhydride (SLG-NCA) monomers afterward lead to enlarged angles with respect to the substrate. Due to swelling, a pronounced change in helix orientation of grafted PMLGSLG 70/30 in n-hexadecane was observed, resulting in an almost perpendicular helix orientation.

Horizontally oriented plates in clouds

Horizontally oriented plates in clouds generate a sharp specular reflectance signal in the glint direction, often referred to as "subsun". This signal (amplitude and width) may be used to analyze the relative area fraction of oriented plates in the cloud top layer and their characteristic tilt angle to the horizontal. We make use of spaceborne measurements from the POLDER instrument to provide a statistical analysis of these parameters. More than half of the clouds show a detectable maximum reflectance in the glint direction, although this maximum may be rather faint. The typical effective fraction (area weighted) of oriented plates in clouds lies between 10-3 and 10-2. For those oriented plates, the characteristic tilt angle is less than 1 degree in most cases. These low fractions imply that the impact of oriented plates on the cloud albedo is insignificant. The largest proportion of clouds with horizontally oriented plates is found in the range 500-700 hPa, in agreement with typical in situ observation of plates in clouds. We propose a simple aerodynamic model that accounts for the orienting torque of the flow as the plate falls under its own gravity and the disorienting effects of Brownian motion and atmospheric turbulence. The model indicates that the horizontal plate diameters are in the range 0.1 to a few millimeters. For such sizes, Brownian forces have a negligible impact on the plate orientation. On the other hand, typical levels of atmospheric turbulence lead to tilt angles that are similar to those estimated from the glint observation

One-Pot Selective Catalytic Synthesis of Pyrrolidone Derivatives from Ethyl Levulinate and Nitro Compounds

This is the peer reviewed version of the following article: Vidal, Juan D, Climent Olmedo, María José, Corma Canós, Avelino, Concepción Heydorn, Patricia, Iborra Chornet, Sara. (2017). One-Pot Selective Catalytic Synthesis of Pyrrolidone Derivatives from Ethyl Levulinate and Nitro Compounds .ChemSusChem, 10, 1, 119-128, which has been published in final form at http://doi.org/10.1002/cssc.201601333. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] N-substituted 5-methyl-2-pyrrolidones were prepared in a one-pot process starting from ethyl levulinate and nitro compounds in the presence of a nanosized Pt-based catalyst. Pt supported on TiO2 nanotubes (Pt/TiO2-NT) catalyzed the synthesis of N-substituted 5-methyl-2-pyrrolidones through a cascade process involving the reduction of nitro compounds, formation of the intermediary imine, hydrogenation, and subsequent cyclization. A bifunctional metal acid system was a suitable catalyst for the process. Pt supported on TiO2 showed lower catalytic activity than Pt/TiO2-NT owing to the strong adsorption of nitro compounds during the first reaction step that poisoned the acidic sites and strongly decreased the rate of amination and cyclization. However, Pt/TiO2-NT with milder acid sites was less affected by the adsorption of nitro compounds and the full cascade process could proceed. The results indicate that the prepared Pt/TiO2-NT is a chemoselective and reusable catalyst that can be applied to the synthesis of a variety of N-substituted 5-methyl-2-pyrrolidones starting from nitro compounds with excellent yields in absence of an additional organic solvent under mild reaction conditions.Financial support by Consolider-Ingenio 2010 (Project Multicat), Spanish MICINN Project (CTQ-2015-67592-P), Generalitat Valenciana (Prometeo Program) and Program Severo Ochoa is gratefully acknowledged.Vidal, JD.; Climent Olmedo, MJ.; Corma Canós, A.; Concepción Heydorn, P.; Iborra Chornet, S. (2017). One-Pot Selective Catalytic Synthesis of Pyrrolidone Derivatives from Ethyl Levulinate and Nitro Compounds. ChemSusChem. 10(1):119-128. https://doi.org/10.1002/cssc.201601333S119128101Vispute, T. P., Zhang, H., Sanna, A., Xiao, R., & Huber, G. W. (2010). Renewable Chemical Commodity Feedstocks from Integrated Catalytic Processing of Pyrolysis Oils. Science, 330(6008), 1222-1227. doi:10.1126/science.1194218Climent, M. J., Corma, A., & Iborra, S. (2014). Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels. Green Chemistry, 16(2), 516. doi:10.1039/c3gc41492bCorma, A., Iborra, S., & Velty, A. (2007). Chemical Routes for the Transformation of Biomass into Chemicals. Chemical Reviews, 107(6), 2411-2502. doi:10.1021/cr050989dCliment, M. J., Corma, A., & Iborra, S. (2011). Converting carbohydrates to bulk chemicals and fine chemicals over heterogeneous catalysts. Green Chemistry, 13(3), 520. doi:10.1039/c0gc00639dGallezot, P. (2012). Conversion of biomass to selected chemical products. Chem. Soc. Rev., 41(4), 1538-1558. doi:10.1039/c1cs15147aTop Value Added Chemicals from Biomass. Results of Screening for Potential Candidates from Sugars and Synthesis Gas, Vol. 1 2004 http://www.nrel.gov/docs/fy04osti/35523.pdfBozell, J. J., & Petersen, G. R. (2010). Technology development for the production of biobased products from biorefinery carbohydrates—the US Department of Energy’s «Top 10» revisited. Green Chemistry, 12(4), 539. doi:10.1039/b922014cGürbüz, E. I., Alonso, D. M., Bond, J. Q., & Dumesic, J. A. (2011). Reactive Extraction of Levulinate Esters and Conversion to γ-Valerolactone for Production of Liquid Fuels. ChemSusChem, 4(3), 357-361. doi:10.1002/cssc.201000396L. E. Manzer E. I. Du Ponte De Nemours And Company US6743819B1 2004L. E. Manzer US20060247443A1 2006Wei, Y., Wang, C., Jiang, X., Xue, D., Li, J., & Xiao, J. (2013). Highly efficient transformation of levulinic acid into pyrrolidinones by iridium catalysed transfer hydrogenation. Chemical Communications, 49(47), 5408. doi:10.1039/c3cc41661eHuang, Y.-B., Dai, J.-J., Deng, X.-J., Qu, Y.-C., Guo, Q.-X., & Fu, Y. (2011). Ruthenium-Catalyzed Conversion of Levulinic Acid to Pyrrolidines by Reductive Amination. ChemSusChem, 4(11), 1578-1581. doi:10.1002/cssc.201100344Ortiz-Cervantes, C., Flores-Alamo, M., & García, J. J. (2016). Synthesis of pyrrolidones and quinolines from the known biomass feedstock levulinic acid and amines. Tetrahedron Letters, 57(7), 766-771. doi:10.1016/j.tetlet.2016.01.018Du, X.-L., He, L., Zhao, S., Liu, Y.-M., Cao, Y., He, H.-Y., & Fan, K.-N. (2011). Hydrogen-Independent Reductive Transformation of Carbohydrate Biomass into γ-Valerolactone and Pyrrolidone Derivatives with Supported Gold Catalysts. Angewandte Chemie International Edition, 50(34), 7815-7819. doi:10.1002/anie.201100102Du, X.-L., He, L., Zhao, S., Liu, Y.-M., Cao, Y., He, H.-Y., & Fan, K.-N. (2011). Hydrogen-Independent Reductive Transformation of Carbohydrate Biomass into γ-Valerolactone and Pyrrolidone Derivatives with Supported Gold Catalysts. Angewandte Chemie, 123(34), 7961-7965. doi:10.1002/ange.201100102Wei, Y., Wang, C., Jiang, X., Xue, D., Liu, Z.-T., & Xiao, J. (2014). Catalyst-free transformation of levulinic acid into pyrrolidinones with formic acid. Green Chem., 16(3), 1093-1096. doi:10.1039/c3gc42125bLedoux, A., Sandjong Kuigwa, L., Framery, E., & Andrioletti, B. (2015). A highly sustainable route to pyrrolidone derivatives – direct access to biosourced solvents. Green Chem., 17(6), 3251-3254. doi:10.1039/c5gc00417aL. E. Manzer E. I. Du Pont De Nemours And Company US7129362B2 2006L. E. Manzer US20060247444A1 2006Chieffi, G., Braun, M., & Esposito, D. (2015). Continuous Reductive Amination of Biomass-Derived Molecules over Carbonized Filter Paper-Supported FeNi Alloy. ChemSusChem, 8(21), 3590-3594. doi:10.1002/cssc.201500804Touchy, A. S., Hakim Siddiki, S. M. A., Kon, K., & Shimizu, K. (2014). Heterogeneous Pt Catalysts for Reductive Amination of Levulinic Acid to Pyrrolidones. ACS Catalysis, 4(9), 3045-3050. doi:10.1021/cs500757kVidal, J. D., Climent, M. J., Concepcion, P., Corma, A., Iborra, S., & Sabater, M. J. (2015). Chemicals from Biomass: Chemoselective Reductive Amination of Ethyl Levulinate with Amines. ACS Catalysis, 5(10), 5812-5821. doi:10.1021/acscatal.5b01113ChemCatChem 2016 10.1002/cctc.201600739Climent, M. J., Corma, A., & Iborra, S. (2011). Heterogeneous Catalysts for the One-Pot Synthesis of Chemicals and Fine Chemicals. Chemical Reviews, 111(2), 1072-1133. doi:10.1021/cr1002084José Climent, M., Corma, A., & Iborra, S. (2012). Homogeneous and heterogeneous catalysts for multicomponent reactions. RSC Adv., 2(1), 16-58. doi:10.1039/c1ra00807bYoshida, H., Igarashi, N., Fujita, S., Panpranot, J., & Arai, M. (2014). Influence of Crystallite Size of TiO2 Supports on the Activity of Dispersed Pt Catalysts in Liquid-Phase Selective Hydrogenation of 3-Nitrostyrene, Nitrobenzene, and Styrene. Catalysis Letters, 145(2), 606-611. doi:10.1007/s10562-014-1404-4L. E. Manzer E. I. Du Pont De Nemours And Company US6855731B2 2005L. E. Manzer E. I. Du Pont De Nemours And Company US6818593B2 2004Yang, X., Yu, X., Long, L., Wang, T., Ma, L., Wu, L., … Liao, S. (2014). Pt nanoparticles entrapped in titanate nanotubes (TNT) for phenol hydrogenation: the confinement effect of TNT. Chemical Communications, 50(21), 2794. doi:10.1039/c3cc49331hHsu, C.-Y., Chiu, T.-C., Shih, M.-H., Tsai, W.-J., Chen, W.-Y., & Lin, C.-H. (2010). Effect of Electron Density of Pt Catalysts Supported on Alkali Titanate Nanotubes in Cinnamaldehyde Hydrogenation. The Journal of Physical Chemistry C, 114(10), 4502-4510. doi:10.1021/jp9095198Chiu, T.-C., Lee, H.-Y., Li, P.-H., Chao, J.-H., & Lin, C.-H. (2013). Effects of interfacial charge and the particle size of titanate nanotube-supported Pt nanoparticles on the hydrogenation of cinnamaldehyde. Nanotechnology, 24(11), 115601. doi:10.1088/0957-4484/24/11/115601Zhu, B., Li, K., Wang, S., Zhang, S., Wu, S., & Huang, W. (2008). Influences of the H2PtCl6Solution’s pH on the Photocatalytic Activities of Platinum-Loaded TiO2Nanotubes. Journal of Dispersion Science and Technology, 29(10), 1408-1411. doi:10.1080/01932690802313311XIAO-JING, H., BAO-LIN, Z., JIAN-XUN, D., WEI-LING, Z., SHU-RONG, W., SHOU-MIN, Z., & WEI-PING, H. (2012). THE INFLUENCE OF PLATINUM ON THE STRUCTURE AND PHOTOCATALYTIC PERFORMANCE OF HYDROGEN TITANATE NANOTUBES. Journal of the Chilean Chemical Society, 57(1), 1008-1011. doi:10.4067/s0717-97072012000100012Kubo, T., Nagata, H., Takeuchi, M., Matsuoka, M., Anpo, M., & Nakahira, A. (2008). Structural evaluation and photocatalytic properties of Pt-supported titanate nanotubes. Research on Chemical Intermediates, 34(4), 339-346. doi:10.1163/156856708784040605Hadjiivanov, K. I. (1998). IR study of CO and H2O coadsorption on Ptn+/TiO2 and Pt/TiO2 samples. Journal of the Chemical Society, Faraday Transactions, 94(13), 1901-1904. doi:10.1039/a801892hShen, S., Wang, X., Ding, Q., Jin, S., Feng, Z., & Li, C. (2014). Effect of Pt cocatalyst in Pt/TiO2 studied by in situ FTIR of CO adsorption. Chinese Journal of Catalysis, 35(11), 1900-1906. doi:10.1016/s1872-2067(14)60172-8Greenler, R. G., Burch, K. D., Kretzschmar, K., Klauser, R., Bradshaw, A. M., & Hayden, B. E. (1985). Stepped single-crystal surfaces as models for small catalyst particles. Surface Science, 152-153, 338-345. doi:10.1016/0039-6028(85)90163-3Jiang, F., Zeng, L., Li, S., Liu, G., Wang, S., & Gong, J. (2014). Propane Dehydrogenation over Pt/TiO2–Al2O3 Catalysts. ACS Catalysis, 5(1), 438-447. doi:10.1021/cs501279vSerna, P., López-Haro, M., Calvino, J. J., & Corma, A. (2009). Selective hydrogenation of nitrocyclohexane to cyclohexanone oxime with H2 on decorated Pt nanoparticles. Journal of Catalysis, 263(2), 328-334. doi:10.1016/j.jcat.2009.02.025Climent, M. J., Corma, A., Iborra, S., & Santos, L. L. (2009). Multisite Solid Catalyst for Cascade Reactions: The Direct Synthesis of Benzodiazepines from Nitro Compounds. Chemistry - A European Journal, 15(35), 8834-8841. doi:10.1002/chem.200900492Climent, M. J., Corma, A., Iborra, S., & Martí, L. (2014). Process Intensification with Bifunctional Heterogeneous Catalysts: Selective One-Pot Synthesis of 2′-Aminochalcones. ACS Catalysis, 5(1), 157-166. doi:10.1021/cs5011713Corma, A., Concepción, P., & Serna, P. (2007). A Different Reaction Pathway for the Reduction of Aromatic Nitro Compounds on Gold Catalysts. Angewandte Chemie International Edition, 46(38), 7266-7269. doi:10.1002/anie.200700823Corma, A., Concepción, P., & Serna, P. (2007). A Different Reaction Pathway for the Reduction of Aromatic Nitro Compounds on Gold Catalysts. Angewandte Chemie, 119(38), 7404-7407. doi:10.1002/ange.200700823Corma, A., Serna, P., Concepción, P., & Calvino, J. J. (2008). Transforming Nonselective into Chemoselective Metal Catalysts for the Hydrogenation of Substituted Nitroaromatics. Journal of the American Chemical Society, 130(27), 8748-8753. doi:10.1021/ja800959gKasuga, T., Hiramatsu, M., Hoson, A., Sekino, T., & Niihara, K. (1998). Formation of Titanium Oxide Nanotube. Langmuir, 14(12), 3160-3163. doi:10.1021/la971381

Development of the Pediatric Quality of Life Inventory™ Eosinophilic Esophagitis Module items: qualitative methods

BACKGROUND: Currently there is no disease-specific outcome measure to assess the health-related quality of life (HRQOL) of pediatric patients with Eosinophilic Esophagitis (EoE). Therefore, the objective of this qualitative study was to further develop and finalize the items and support the content validity for the new Pediatric Quality of Life Inventory™ (PedsQL™) Eosinophilic Esophagitis Module. METHODS: Multiphase qualitative methodology was utilized in the development of the PedsQL™ EoE Module conceptual model. Focus interview transcripts of pediatric patients with EoE and their parents and expert review were previously used to develop the initial items and domains for the PedsQL™ EoE Module. In the current investigation, utilizing the respondent debriefing methodology, cognitive interviewing was conducted individually with pediatric patients with EoE and their parents on each newly developed item. RESULTS: Information from a total of 86 participants was obtained in combination from the previous investigation and the current study. From the previous 42 focus interviews, items were developed around the domain themes of symptoms, difficulties with eating food, treatment adherence, worry about symptoms and illness, feelings of being different than family and peers, and problems discussing EoE with others. In the current study’s cognitive interviewing phase, a separate cohort of 44 participants systematically reviewed and provided feedback on each item. Items were added, modified or deleted based on this feedback. Items were finalized after this feedback from patients and parents. CONCLUSIONS: Using well-established qualitative methods, the content validity of the new PedsQL™ Eosinophilic Esophagitis Module items was supported in the current investigation. In the next iterative instrument development phase, the PedsQL™ Eosinophilic Esophagitis Module is now undergoing multisite national field testing

Acrylic Target Vessels for a High-Precision Measurement of theta13 with the Daya Bay Antineutrino Detectors

This paper describes in detail the acrylic target vessels used to encapsulate the target and gamma catcher regions in the Daya Bay experiment's first pair of antineutrino detectors. We give an overview of the design, fabrication, shipping, and installation of the acrylic target vessels and their liquid overflow tanks. The acrylic quality assurance program and vessel characterization, which measures all geometric, optical, and material properties relevant to {\nu}e detection at Daya Bay are summarized. This paper is the technical reference for the Daya Bay acrylic vessels and can provide guidance in the design and use of acrylic components in future neutrino or dark matter experiments.Comment: 47 pages, 38 Figures, 14 Tables. Submitted to JINS