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Method Consisting (method + consisting)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

[Ru(0)]@SiO2 and [RuO2]@SiO2 Hybrid Nanomaterials: From Their Synthesis to Their Application as Catalytic Filters for Gas Sensors

ADVANCED FUNCTIONAL MATERIALS, Issue 23 2009
Victor Matsura
Abstract [Ru(0)]@SiO2 and [RuO2]@SiO2 hybrid nanomaterials are produced following a facile method consisting of the synthesis of size-controlled ruthenium nanoparticles as elemental bricks. This route takes advantage of the organometallic approach and the use of a bifunctional ligand for the synthesis of ruthenium nanoparticles from [Ru(COD)(COT)](COD,=,1,3-cyclooctadiene, COT,=,1,3,5-cyclooctatriene) as metal precursor and (PhCH2)2N(CH2)11O(CH2)3Si(OEt)3 (benzenemethanamine) as stabilizer. Hydrolysis and polycondensation steps via a sol,gel approach lead to the formation of the silica materials containing the metal nanoparticles. A final calcination step in air at 400,°C yields the [RuO2]@SiO2 nanocomposites. Such hybrid nanomaterials display a good dispersion of the nanoparticles inside the silica matrix and interesting porosity properties making them attractive materials for catalytic applications. This is shown by using [RuO2]@SiO2 hybrid nanomaterials as catalytic filters for gas sensors. [source]

Design approach for the hybrid underground station at Union Suare/Market Street in San Francisco.

GEOMECHANICS AND TUNNELLING, Issue 4 2009
Entwurfskonzept für eine hybride U-Bahnstation Union Square/Market Street in San Francisco
Abstract The new Central Subway extension through downtown San Francisco consists of three underground stations and 2.7 km TBMdriven twin tunnel. This paper provides a description of the preliminary analyses and design of the ground support and final lining for the Union Square\Market Street Station (UMS) along Stockton Street. This station will serve the Union Square Shopping District and connect to the BART Powell Street Station. Due to shortage of space above ground and to minimize surface disruption, the UMS station design requires a complex hybrid method consisting of a 20 m deep braced cut-and-cover box with a mined enlargement bulb below it with a height of 9.3 m and a width of 17.8 m. The majority of the UMS station will be excavated in saturated alluvial deposits. Undifferentiated old bay deposits will be encountered in the invert, underlain by dense marine sands. The groundwater varies from 5 to 10 m below ground level, so uplift of the combined bulb/box structure has to be taken into account. The Finite Element (FE) analysis of the UMS station cavern reflects the separate construction phases of the station platform box and the bulb to account for soil-structure interaction and load-sharing effects. FE analyses are used to estimate support requirements including ground improvement and to predict surface settlements. Die Erweiterung der Central Subway durch die Innenstadt von San Francisco beinhaltet drei Stationsbauwerke und 2,7 km maschinell vorgetriebene Doppelröhrentunnel. In diesem Artikel erfolgt eine Beschreibung der Voruntersuchungen und Vorbemessung der Stützmaßnahmen sowie der Innenschale der Union Square\Market Street Station (UMS) im Verlauf der Stockton Street. Diese Station soll dem Union Square Shopping Distrikt dienen und zur BART Powell Street Station verbinden. Aufgrund der beengten Platzverhältnisse und zur Minimierung der Beeinträchtigung der Oberfläche ist ein "hybrides" Konzept der UMS-Station erforderlich. Dieses besteht aus einer 20 m tiefen ausgesteiften Baugrube (Box) und einer darunterliegenden bergmännisch hergestellten Kaverne (Bulb) mit 9,3 m Höhe und 17,8 m Breite. Der Großteil der UMS-Station befindet sich in gesättigten alluvialen Ablagerungen. Undifferenziert werden alte Bucht-Ablagerungen und dichte marine Sande in der Sohle vorgefunden. Der Grundwasserspiegel variiert in einer Teufe zwischen 5 bis 10 m unter der Oberfläche, aus diesem Grund ist der Auftrieb des kombinierten Bauwerks bestehend aus Bulb und Box zu berücksichtigen. In Finite Element (FE) Berechnungen der UMS-Station werden die einzelnen Bauphasen des Stationsbauwerks, sowohl von Box als auch Bulb, modelliert, um die Wechselwirkungen von Baugrund-Bauwerk und die jeweiligen Lastumlagerungen zu berücksichtigen. Mittels FE-Berechnungen werden schließlich die notwendigen Stützmaßnahmen , diese beinhalten auch Bodenverbesserungsmaßnahmen , und die Oberflächensetzungen festgelegt. [source]

Fabrication of Polyimide-Blend Thin Films Containing Uniformly Oriented Silver Nanorods and Their Use as Flexible, Linear Polarizers

ADVANCED MATERIALS, Issue 18 2005
S. Matsuda
Fully aromatic polyimide films containing uniformly oriented Ag nanorods (see Figure) have been prepared by a simple method consisting of thermal curing and uniaxial drawing of submicrometer-scale phase-separated polyimide-blend films containing dissolved AgNO3. The films exhibit outstanding optical dichroism, over 20,dB (see inset), in the near-IR region due to the high aspect ratio of the nanorods and the high transparency of the matrix. [source]

Synthesis and cationic photopolymerization of epoxy-functional siloxane monomers and oligomers

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2003
Myoungsouk Jang
Abstract A series of difunctional silicon-containing monomers were prepared with a novel method consisting of the monohydrosilation of an ,,,-difunctional SiH-terminated siloxane with a vinyl-functional epoxide or oxetane followed by the dehydrodimerization of the resulting SiH-functional intermediate. This method used simple, readily available starting materials and could be conducted as a streamlined one-pot, two-step synthesis. This novel method was also applied to the synthesis of several epoxy,silicone oligomers. The reactivities of these new monomers and oligomers were examined with Fourier transform real-time infrared spectroscopy and optical pyrometry. Those monomers containing epoxycyclohexyl groups displayed excellent reactivity in cationic ring-opening polymerization in the presence of lipophilic onium salt photoinitiators. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3056,3073, 2003 [source]