534 research outputs found

    An investigation of failure patterns of layered specimens loaded in uniaxial compression

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    Uniaxial compressive strength for two and three-layered specimens was obtained with different thicknesses of layers and also for different length to diameter ratios. The fracture and failure pattern was studied. Shear and extension fractures were observed in the layers. Geometry and end conditions of the specimen had a great influence in the failure and fracture pattern. The uniaxial compressive strength of a layered specimen was found to be lower than the weighted average strength and either low or high when compared to the arithmetic average strength, depending on the ratio of the heights of the layers. The compressive strength of a layered specimen increases as the ratio of length to diameter decreases. The influence of the number of non-cohesive interfaces on compressive strength has also been observed. Suggestions are made for calculating the compressive strength of a layered pillar --Abstract, page ii

    Ring opening of oxiranes catalyzed by Mn-Salen immobilized mesoporous materials

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    Mn-Salen immobilized mesoporous materials were found to be efficient solid catalysts for the nucleophilic ring opening of oxiranes with TMSN3, TMSCN and aniline

    The first example of heterogeneous oxidation of secondary amines by tungstate-exchanged Mg-Al layered double hydroxides: a green protocol

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    Tungstate exchanged Mg-Al layered double hydroxides a as recyclable heterogenised catalyst along with H2O2 as an oxidant for the oxidation of sec-amines to nitrones is developed for the first time, Reactions proceed at a fast rate in aqueous media in a single step at room temperature in good to excellent yields. The heterogenised catalyst showed higher activity (TOF) over their homogeneous analogues and other heterogeneous catalysts reported so far. The obtained catalysts were well characterised by various instrumental techniques such as FT-IR spectroscopy, thermal analysis (TGA and DTA), powder XRD and chemical analysis. The catalyst can be reused for six cycles with consistent activity and selectivity

    Polymer-anchored palladium catalyst in carbonylation of organic halides - the first example of triphase catalysis

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    Polymer-anchored palladium-catalysed carbonylation of organic halides affords oxo esters in reasonable- yields under solid-liquid-solid phase transfer conditions at mild pressure and short durations

    Henry reactions catalysed by modified Mg-Al hydrotalcite: an efficient reusable solid base for selective synthesis of β-nitroalkanols

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    Henry reactions have been performed for the first time with suitably activated Mg-Al hydrotalcite as catalyst in quantitative yields in the liquid phase under mild reaction conditions and with low reaction times. Exclusive synthesis of β-nitroalkanols (3) is realised by the compatible basic Bronsted hydroxy sites of the modified hydrotalcite. Reusability with consistent activity and selectivity for a number of cycles is established indicating that the hydrated hydrotalcite employed here is a potentially eco-friendly catalyst which can replace soluble bases in commercial synthesis

    The first example of direct oxidation of sulfides to sulfones by an osmate molecular oxygen system

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    Osmate-exchanged Mg-Al layered double hydroxides catalysed the delivery of two oxygen atoms simultaneously via a 3 + 1 cycloaddition to sulfide to form sulfone directly for the first time, reminiscent of 3 + 2 cycloaddition in asymmetric dihydroxylation reactions

    Hydrotalcite-like compounds for liquid-phase oxidation of benzylic hydrocarbons

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    Is surgery the only option for unstable ankle fracture?

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    Background: Ankle fracture is one of the most common injuries in sports and daily activity. Unstable ankle fracture that are displaced fracture of the lateral malleolus and most bimalleolar or trimalleolar fractures need surgical reduction and fixation.Methods: It is a single centre study in which all unstable ankle fracture above the age of 18 and not associated with any other injury were included in the study. Following fixation patients were followed up at 6 weeks, 3 months and 6 months and functional outcome was assessed with American Orthopaedic Foot and Ankle score (AOFAS).Results: Supination external rotation injury was most common type. Mean AOFAS score at the end of six months was found to be best in supination adduction type. Posterior malleolus fixation with screw were found to have maximum AOFAS score.Conclusions: Surgical outcome in unstable ankle fracture are proved to have good functional outcome

    Overview of Cell Signaling Pathways in Cancer

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    The final authenticated version is available online at https://doi.org/10.1007/978-3-319-95228-4_12
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