851 resultados para Landscape Units


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Novel acid-terminated hyperbranched polymers (HBPs) containing adipic acid and oxazoline monomers derived from oleic and linoleic acid have been synthesized via a bulk polymerization procedure. Branching was achieved as a consequence of an acid-catalyzed opening of the oxazoline ring to produce a trifunctional monomer in situ which delivered branching levels of >45% as determined by 1H and 13C NMR spectroscopy. The HBPs were soluble in common solvents, such as CHCl3, acetone, tetrahydrofuran, dimethylformamide, and dimethyl sulfoxide and were further functionalized by addition of citronellol to afford white-spirit soluble materials that could be used in coating formulations. During end group modification, a reduction in branching levels of the HBPs (down to 12–24%) was observed, predominantly on account of oxazoline ring reformation and trans-esterification processes under the reaction conditions used. In comparison to commercial alkyd resin paint coatings, formulations of the citronellol-functionalized hyperbranched materials blended with a commercial alkyd resin exhibited dramatic decreases of the blend viscosity when the HBP content was increased. The curing characteristics of the HBP/alkyd blend formulations were studied by dynamic mechanical analysis which revealed that the new coatings cured more quickly and produced tougher materials than otherwise identical coatings prepared from only the commercial alkyd resins.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we bring together work on landscape, temporality and lay knowledges to propose new ways of understanding climate change. A focus on the familiar landscapes of everyday life offers an opportunity to examine how climate change could be researched as a relational phenomenon, understood on a local level, with distinctive spatialities and temporalities. Climate change can be observed in relation to landscape but also felt, sensed, apprehended emotionally as part of the fabric of everyday life in which acceptance, denial, resignation and action co-exist as personal and social responses to the local manifestations of a global problem.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The o-palladated, chloro-bridged dimers [Pd{2-phenylpyridine(-H)}-μ-Cl]2 and [Pd{N,N-dimethylbenzylamine(-H)}-μ-Cl]2 react with cyanuric acid in the presence of base to afford closed, chiral cage-molecules in which twelve organo-Pd(II) centers, located in pairs at the vertices of an octahedron, are linked by four tetrahedrally-arranged cyanurato(3-) ligands. Incomplete (Pd10) cages, having structures derived from the corresponding Pd12 cages by replacing one pair of organopalladium centers with two protons, have also been isolated. Reaction of [Pd{2-phenylpyridine(-H)}-μ-Cl]2 with trithiocyanuric acid gives an entirely different and more open type of cage-complex, comprising only nine organopalladium centers and three thiocyanurato(3-) ligands: cage-closure in this latter system appears to be inhibited by steric crowding of the thiocarbonyl groups.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we look at how landscape and climate change are simultaneously apprehended through institutional strategies and then negotiated through local knowledge and social relations on the ground. We argue that by examining landscapes that are practised, embodied and lived, it is possible to gain an understanding of people's actions, beliefs and values in relation to climate and climate change. This attention to cultural landscapes also enables us to ask how a variety of publics make sense of climate change, and how they are invited to do so by organisations that take responsibility for the management and preservation of landscape, such as the National Trust, Europe's biggest conservation organisation. This paper considers how the Trust makes sense of climate change via the document Shifting Shores and how its strategies are operationalised on the Lizard Peninsula, Cornwall, UK.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we show how a seemingly unremarkable object – a cattle grid – has come to presence climate change in partial and contingent ways on the Lizard Peninsula, Cornwall, UK. We identify the cattle grid as an ‘anticipatory object’ through which conservation organisations seek to manage the future and adapt to climate change, but which at the same time presences that unthought-of future for others in the landscape. We explore the ways in which the cattle grid acts to presence something that is not only absent – climate change – but has uncertain imminence. We investigate the ways in which the cattle grid make climate relevant as an embodied and experiential process, a physical and intellectual artefact, and the means to imagine climate and the ways it might change. Drawing upon interpretative approaches informed by theorisations of materiality, presence and absence to understand climate change as a social phenomenon, we go beyond a consideration of this ordinary object defined by its function to consider how the object is experienced, the processes and practices through which people relate to it, and the ways in which social meaning accumulates around it. The empirical basis for this argument is provided by in-depth interviews with local representatives of Natural England, residents and farmers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The financial crisis of 2007-2009 and the subsequent reaction of the G20 have created a new global regulatory landscape. Within the EU, change of regulatory institutions is ongoing. The research objective of this study is to understand how institutional changes to the EU regulatory landscape may affect corresponding institutionalized operational practices within financial organizations and to understand the role of agency within this process. Our motivation is to provide insight into these changes from an operational management perspective, as well as to test Thelen and Mahoney?s (2010) modes of institutional change. Consequently, the study researched implementations of an Investment Management System with a rules-based compliance module within financial organizations. The research consulted compliance and risk managers, as well as systems experts. The study suggests that prescriptive regulations are likely to create isomorphic configurations of rules-based compliance systems, which consequently will enable the institutionalization of associated compliance practices. The study reveals the ability of some agents within financial organizations to control the impact of regulatory institutions, not directly, but through the systems and processes they adopt to meet requirements. Furthermore, the research highlights the boundaries and relationships between each mode of change as future avenues of research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present an integrated palaeoecological and archaeobotanical study of pre-Columbian raised-field agriculture in the Llanos de Moxos, a vast seasonally inundated forest–savanna mosaic in the Bolivian Amazon. Phytoliths from excavated raised-field soil units, together with pollen and charcoal in sediment cores from two oxbow lakes, were analysed to provide a history of land use and agriculture at the El Cerro raised-field site. The construction of raised fields involved the removal of savanna trees, and gallery forest was cleared from the area by AD 310. Despite the low fertility of Llanos de Moxos soils, we determined that pre-Columbian raised-field agriculture sufficiently improved soil conditions for maize cultivation. Fire was used as a common management practice until AD 1300, at which point, the land-use strategy shifted towards less frequent burning of savannas and raised fields. Alongside a reduction in the use of fire, sweet potato cultivation and the exploitation of Inga fruits formed part of a mixed resource strategy from AD 1300 to 1450. The pre-Columbian impact on the landscape began to lessen around AD 1450, as shown by an increase in savanna trees and gallery forest. Although agriculture at the site began to decline prior to European arrival, the abandonment of raised fields was protracted, with evidence of sweet potato cultivation occurring as late as AD 1800.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

While it was happening, European expansion was often legitimised by evoking frontier images: pioneers setting off from the metropolis, penetrating wilderness in order to open access to resources, like minerals, living-space, and fertile lands. Central to the ideology of the frontier is the notion of 'no-man's land'. These 'pioneers', however, often had to face local inhabitants and their interpretations and uses of this land. Thus it will be argued that contestations over landscape were at the same time battles over the legitimation of European expansion, as well as over local perceptions of this process. Ideologically, contestations by Europeans and Africans become apparent in the sexualisation of landscape. This paper is based on the case study of a Valley in eastern Zimbabwe on the border with Mozambique, and more specifically of two tea estates which were established in the rainforest. Unusually late for the region, European influence in this remote area only began to become significant in the 1950s which were an important turning point regarding land and landscape in the area. These years of great change will be analysed in order to map out different strands of interest by the main parties involved. It will be demonstrated that their readings of landscape translated into contestations over land. A recent example of such a conflict will be given.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study of landscape evolution presents both new modern and palaeo process-landform data, and analyses the behaviour of the Antarctic Peninsula Ice Sheet through the Last Glacial Maximum (LGM), the Holocene and to the present day. Six sediment-landform assemblages are described and interpreted for Ulu Peninsula, James Ross Island, NE Antarctic Peninsula: (1) the Glacier Ice and Snow Assemblage; (2) the Glacigenic Assemblage, which relates to LGM sediments and comprises both erratic-poor and erratic-rich drift, deposited by cold-based and wet-based ice and ice streams respectively; (3) the Boulder Train Assemblage, deposited during a Mid-Holocene glacier readvance; (4) the Ice-cored Moraine Assemblage, found in front of small cirque glaciers; (5) the Paraglacial Assemblage including scree, pebble-boulder lags, and littoral and fluvial processes; and (6) the Periglacial Assemblage including rock glaciers, protalus ramparts, blockfields, solifluction lobes and extensive patterned ground. The interplay between glacial, paraglacial and periglacial processes in this semi-arid polar environment is important in understanding polygenetic landforms. Crucially, cold-based ice was capable of sediment and landform genesis and modification. This landsystem model can aid the interpretation of past environments, but also provides new data to aid the reconstruction of the last ice sheet to overrun James Ross Island.