927 resultados para Demolition works
Resumo:
A study undertaken at the University of Liverpool has investigated the potential for using construction and demolition waste (C&DW) derived aggregate in the manufacture of a range of precast concrete products, i.e. building and paving blocks and pavement flags. Phase III, which is reported here, investigated
concrete pavement flags. This was subsequent to studies on building and paving blocks. Recycled demolition aggregate can be used to replace newly quarried limestone aggregate, usually used in coarse (6 mm) and fine (4 mm-to-dust) gradings. The first objective was, as was the case with concrete building
and paving blocks, to replicate the process used by industry in fabricating concrete pavement flags in the laboratory. The ‘‘wet’’ casting technique used by industry for making concrete flags requires a very workable mix so that the concrete flows into the mould before it is compressed. Compression squeezes out water from the top as well as the bottom of the mould. This industrial casting procedure was successfully replicated in the laboratory by using an appropriately modified cube crushing machine and a special mould typical of what is used by industry. The mould could be filled outside of the cube crushing machine and then rolled onto a steel frame and into the machine for it to be compressed. The texture and mechanical properties of the laboratory concrete flags were found to be similar to the factory ones. The experimental work involved two main series of tests, i.e. concrete flags made with concrete- and
masonry-derived aggregate. Investigation of flexural strength was required for concrete paving flags. This is different from building blocks and paving blocks which required compressive and tensile splitting strength respectively. Upper levels of replacement with recycled demolition aggregate were determined
that produced similar flexural strength to paving flags made with newly quarried aggregates, without requiring an increase in the cement content. With up to 60% of the coarse or 40% of the fine fractions replaced with concrete-derived aggregates, the target mean flexural strength of 5.0 N/mm2 was still
achieved at the age of 28 days. There was similar detrimental effect by incorporating the fine masonry-derived aggregate. A replacement level of 70% for coarse was found to be satisfactory and also conservative. However, the fine fraction replacement could only be up to 30% and even reduced to 15% when used for mixes where 60% of the coarse fraction was also masonry-derived aggregate.
Resumo:
Cross-sectional research has shown that frequency of self-disclosure to outgroup members mediates the positive relationship between intergroup friendship and outgroup attitudes. The current research investigated the relationship between self-disclosure and attitudes in more depth. New undergraduate students were asked to nominate an ingroup or outgroup friend and then report the intimacy of their disclosures to them, their anxiety and attitudes towards a series of social groups, in the first week of the semester and 6 weeks later. Intimacy of disclosure predicted more positive attitudes towards outgroups over time, but this association was only found among participants who nominated an outgroup friend. In the ingroup friend condition, a negative association was found. These associations were mediated by general intergroup anxiety. These relationships highlight the importance of integrating theories of interpersonal and intergroup relations when investigating intergroup contact. Copyright (C) 2011 John Wiley & Sons, Ltd.
Resumo:
The water and wastewater industry in the UK accounts for around 3% of total energy use and just over 1% of total UK greenhouse gas emissions. Targets for greenhouse gas emissions reduction and higher renewable energy penetration, coupled with rising energy costs, growing demand for wastewater services and tightening EU water quality requirements, have led to an increased interest in alternative wastewater treatment methods. The use of short rotation coppice (SRC) willow for the treatment of wastewater effluent is one such alternative, which brings with it the dual benefits of wastewater treatment and production of biomass for energy. In order to assess the effectiveness of SRC willow, it is important to analyse the overall energy balance in terms of energy input versus energy output. This paper carries out an energy life cycle analysis of a specific SRC willow plantation in Northern Ireland to which farmyard washings (dirty water) are applied. The system boundaries include the establishment, maintenance, and harvesting of the plantation, along with the transport and drying of the wood for biomass combustion. The analysis shows that the overall energy balance is positive, and that the direct and indirect energy demands are 12% and 8% of gross energy production respectively. The energy demands of the plantation are compared with the energy required to treat an equivalent nutrient load in a conventional wastewater treatment plant. While a conventional plant consumes 2.6 MJ/m3 , the irrigation system consumes 1.6 MJ/m3 and the net energy production of the scenario is 48 MJ/m3 .
Resumo:
Jonathan Swift wrote perceptively about the emerging commercial society
in Britain in the early eighteenth century. His particular focus was on the
financial revolution and its implications for economic and political stability
as well as for shifts of power between the landed and commercial
classes. Following his return to Ireland Swift’s focus shifted to the developmental
problems of his native country. In several pamphlets he advocated
consumption of domestic products, challenged existing political
structures and made trenchant criticisms of absenteeism and other dysfunctional
aspects of the land tenure system. Swift’s politico-economic
concerns are fully reflected in his best known work, Gulliver’s Travels but
his most pointed criticism of the emerging commercial system is contained
in A Modest Proposal. Written in the form of an economic pamphlet, A
Modest Proposal is ostensibly designed to address the problem of poverty
in Ireland. In addition to its implicit criticism of economic policy in Ireland,
the pamphlet challenges the separation of economics and morality as
evidenced in the writings of William Petty and Bernard Mandeville. Swift
parodies Petty’s political arithmetic but it is suggested here that he also
had in his sights the consequentialist reasoning present in the work of
both authors but explicitly so in Mandeville.
Keywords: financial revolution, public debt, paper credit, rationality, political
arithmetic, consequentialism, Petty (William), Mandeville (Bernard)
Resumo:
This paper explores the production and post-production techniques and tensions in designing sound for film. Considering the films of Lucrecia Martel and Sofia Coppola, amongst others, Greene and Yang will discuss how the soundtrack takes on a primary role in these films and becomes a medium for symbolism, reflection, characterisation, as well as storytelling. There will be a close examination of the processes involved in creating character-orientated soundscapes. These processes are sensitive to the effects sound has on an audience. Exploring how these filmmakers (with their sound teams) utilise the listening experience, including attention to point of audition and sound perception, this paper will critically unpick how such creative decisions are arrived at during various stages of the production process. Outlining the use of diegetic and non-diegetic sound and the potential musicality of sound effect design, issues of reverberation, noise and intent are discussed to highlight the sonic framing of these creative teams. Greene will approach these soundtracks from a production/post-production perspective, while Yang will explore the composer’s/designer’s ear.
Resumo:
Stephen B. Dobranski, Milton Quarterly 49.3 (October, 2015), 181-4:
'By addressing classical and neo-Latin works with which Milton's poems appear to engage, Haan has pursued something unattempted yet. Her erudite and engaging commentary on the Poemata is the most extensive and impressive that I have encountered in any edition ... Haan's discussion of Milton's Poemata - including the Testimonia, the one Italian and four Latin encomia by the poet's acquaintances published in 1645 and 1673 - is remarkably detailed and well-researched. In these sections, readers learn, for example, how Milton's Epitaphium Damonis borrows from both classical writers (Theocritus, Moschus) and contemporary models (Castiglione, Zanchi) while transcending all of them through a pattern of resurrection motifs. Or, readers can discover affinities between Milton's lament on the death of the Bishop of Ely and a poem by the Italian humanist Hieronymo Aleander, Jr., or learn about the connections between Milton's Elegia Quinta and George Buchanan's Maiae Calendae ... The Shorter Poems is a scholarly achievement of the highest order.'
Noam Reisner, Review of English Studies 65 (2014), 744-5:
‘Haan shines with her Neo-Latinist expertise by offering a vivid separate introduction to the Latin poems, which sets up Milton’s poemata specifically within the Neo-Latin contexts of the seventeenth century, thereby dispelling any remaining view of these poems as juvenilia (a view which results from reading the poems chronologically). … The present volume will instantly establish itself as the definitive resource for any reader interested in Milton’s shorter poems, and it is scarcely imaginable that it will ever be eclipsed or be in need of replacing. Its contribution is important in all areas, especially in providing for the first time in a single volume truly valuable documents which can teach us a lot more about Milton’s poetic development than simply reading the poems in chronological sequence. But perhaps, this edition’s greatest achievement is the way in which it succeeds in giving Milton’s Latin poems the pride of place they have long deserved as fully integral to Milton’s complete poetic imagination. Haan’s specific achievement in this regard is less in updating the translations than in providing a different context through which to look at the Latin poems themselves. Haan’s detailed commentaries set the Latin poems in a completely fresh light which looks beyond the obvious classical references and allusions, noted by Carey and many other editors, to Milton’s complex engagement with the Neo-Latin literary culture of his time. It is this aspect of the volume, more than anything else, which vindicates its essentialness.'
Resumo:
There have been considerable developments in Merseyside over the last fifteen years with regards to the commercialisation of recycled demolition aggregate. Liverpool is an urban region that at the time was undergoing regeneration. This required the demolition of old infrastructure. Subsequent reconstruction required new construction materials. A project started in 2001 to investigate the economics, practicalities and technicalities of using recycled demolition aggregates in concrete precast products. It was estimated that if all six demolition contractors around Liverpool worked round the clock (i.e. assuming there was enough feed material) they would still have found it difficult to maintain the required supplies for a single precast factory. Investment in equipment was therefore required to guarantee supply and improve the quality of the recycled demolition aggregate. The market forces and the incentives/drivers for construction companies to adopt sustainable practises have encouraged investment of several million pounds to be made in new recycling plants and has resulted in ‘urban quarries’. This paper describes the developments in recycling of construction and demolition waste over the last decade in Merseyside and shows that recycling is not only sustainable but also profitable.
Resumo:
Peak power consumption is the first order design constraint of data centers. Though peak power consumption is rarely, if ever, observed, the entire data center facility must prepare for it, leading to inefficient usage of its resources. The most prominent way for addressing this issue is to limit the power consumption of the data center IT facility far below its theoretical peak value. Many approaches have been proposed to achieve that, based on the same small set of enforcement mechanisms, but there has been no corresponding work on systematically examining the advantages and disadvantages of each such mechanism. In the absence of such a study,it is unclear what is the optimal mechanism for a given computing environment, which can lead to unnecessarily poor performance if an inappropriate scheme is used. This paper fills this gap by comparing for the first time five widely used power capping mechanisms under the same hardware/software setting. We also explore possible alternative power capping mechanisms beyond what has been previously proposed and evaluate them under the same setup. We systematically analyze the strengths and weaknesses of each mechanism, in terms of energy efficiency, overhead, and predictable behavior. We show how these mechanisms can be combined in order to implement an optimal power capping mechanism which reduces the slow down compared to the most widely used mechanism by up to 88%. Our results provide interesting insights regarding the different trade-offs of power capping techniques, which will be useful for designing and implementing highly efficient power capping in the future.