7,500 research outputs found

    Long exact sequences for de Rham cohomology of diffeological spaces

    Full text link
    In this paper we present the notion of de Rham cohomology with compact support for diffeological spaces. Moreover we shall discuss the existence of three long exact sequences. As a concrete example, we show that long exact sequences exist for the de Rham cohomology of diffeological subcartesian spaces.Comment: 12 page

    Influence of polymerisation conditions on the properties of polymer/clay nanocomposite hydrogels

    Get PDF
    Free-radical polymerisation of acrylamide derivatives in the presence of exfoliated clay platelets has recently emerged as a new technique for the synthesis of strong and tough nanocomposite hydrogels (NCHs) with a unique hybrid organic/inorganic network structure. The central intent of many research studies in the field of NCHs conducted so far was to change hydrogel properties with the introduction of various clays and variation of the clay content. Here, we demonstrate that the properties of NCHs significantly vary depending on initiating conditions used for hydrogel synthesis via in situ polymerisation in solutions of high monomer concentrations (above 1 mol L-1 ). A unique, complementary combination of real-time dynamic rheology and pulsed NMR/MRI has been used to study the influence of the composition of a redox initiating system on the gelation process and hydrogel properties. The molar ratio of the persulphate initiator to tertiary amine activator affects the polymerisation kinetics, morphology and mechanical properties of the hydrogels. We further show that activator-dominated systems tend to produce hydrogels with higher storage modulus and lower water intake. This trend is attributed to the increase in the cross-linking degree. From the analysis of the water state in NCH and hydrogels prepared with and without an organic cross-linker, it was concluded that clay platelets did not form covalent bonds with polymer molecules but contributed to the formation of a physical network. There is evidence of self-crosslinking of polymer chains during acrylamide polymerisation at high monomer concentration. The composition of the initiating system influences the number of formed self-crosslinks

    Emerging Patterns of Manufacturing Structural Change

    Get PDF
    In the past, research on changes in relative importance among broad three sectors— agriculture, industry, and service—showed general patterns of a country’s structural transformation along with economic development. However, there has been devoid of empirical studies investigating in the structural change within the manufacturing sector, which often plays a role of the engine in economic growth. Our analysis looks into the evolution of production structures prevailing at certain development stages while controlling for country-given characteristics such as size, resource endowments, and others. This can provide an industrial policy framework for structural change facilitation that can lead to sustained economic development in the long run.industrial development, growth, industrial policy, manufacturing development patterns, comparative advantage

    ON MODEL STRUCTURE FOR COREFLECTIVE SUBCATEGORIES OF A MODEL CATEGORY

    Get PDF

    Background and enhanced condensation nucleus observed by UAV around the edge of East Antarctica in summer

    Get PDF
    The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

    A Re-examination of Modality

    Get PDF
    corecore