62 resultados para Defect introduction and removal process

em CentAUR: Central Archive University of Reading - UK


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Despite advances in tissue culture techniques, propagation by leafy, softwood cuttings is the preferred, practical system for vegetative reproduction of many tree and shrub species. Species are frequently defined as 'difficult'- or 'easy-to-root' when propagated by conventional cuttings. Speed of rooting is often linked with ease of propagation, and slow-to-root species may be 'difficult' precisely because tissues deteriorate prior to the formation of adventitious roots. Even when roots form, limited development of these may impair the establishment of a cutting. In this study we used softwood cuttings of cashew (Anacardium occidentale), a species considered as 'difficult-to-root'. We aimed to test the hypothesis that speed, and extent of early rooting, is critical in determining success with this species; and that the potential to form adventitious roots will decrease with time in the propagation environment. Using two genotypes, initial rooting rates were examined in the presence or absence of exogenous auxin. In cuttings that formed adventitious roots, either entire roots or root tips were removed, to determine if further root formation/development was feasible. To investigate if subsequent root responses were linked to phytohormone action, a number of cuttings were also treated with either exogenous auxin (indole-3-butyric acid-IBA) or cytokinin (zeatin). Despite the reputation of Anacardium as being 'difficult-to-root', we found high rooting rates in two genotypes (AC 10 and CCP 1001). Removing adventitious roots from cuttings and returning them to the propagation environment, resulted in subsequent re-rooting. Indeed, individual cuttings could develop new adventitious roots on four to five separate occasions over a 9 week period. Data showed that rooting potential increased, not decreased with time in the propagation environment and that cutting viability was unaffected. Root expression was faster (8-15 days) after the removal of previous roots compared to when the cuttings were first stuck (21 days). Exposing cuttings to IBA at the time of preparation, improved initial rooting in AC 10, but not in CCP 1001. Application of IBA once roots had formed had little effect on subsequent development, but zeatin reduced root length and promoted root number and dry matter accumulation. These results challenge our hypothesis, and indicate that rooting potential remains high in Anacardium. The precise mechanisms that regulate the number of adventitious roots expressed, remain to be determined. Nevertheless, results indicate that rooting potential can be high in 'difficult-to-root' species, and suggest that providing supportive environments is the key to expressing this potential. (c) 2006 Elsevier B.V. All rights reserved.

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The complexity of construction projects and the fragmentation of the construction industry undertaking those projects has effectively resulted in linear, uncoordinated and highly variable project processes in the UK construction sector. Research undertaken at the University of Salford resulted in the development of an improved project process, the Process Protocol, which considers the whole lifecycle of a construction project whilst integrating its participants under a common framework. The Process Protocol identifies the various phases of a construction project with particular emphasis on what is described in the manufacturing industry as the ‘fuzzy front end’. The participants in the process are described in terms of the activities that need to be undertaken in order to achieve a successful project and process execution. In addition, the decision-making mechanisms, from a client perspective, are illustrated and the foundations for a learning organization/industry are facilitated within a consistent Process Protocol.

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Literacy as a social practice is integrally linked with social, economic and political institutions and processes. As such, it has a material base which is fundamentally constituted in power relations. Literacy is therefore interwoven with the text and context of everyday living in which multi-levelled meanings are organically produced at both individual and societal level. This paper argues that if language thus mediates social reality, then it follows that literacy defined as a social practice cannot really be addressed as a reified, neutral activity but that it should take account of the social, cultural and political processes in which literacy practices are embedded. Drawing on the work of key writers within the field, the paper foregrounds the primary role of the state in defining the forms and levels of literacy required and made available at particular moments within society. In a case-study of the social construction of literacy meanings in pre-revolutionary Iran, it explores the view that the discourse about societal literacy levels has historically constituted a key terrain in which the struggle for control over meaning has taken place. This struggle, it is argued, sets the interests of the state to maintain ideological and political control over the production of knowledge within the culture and society over and against the needs identified by the individual for personal development, empowerment and liberation. In an overall sense, the paper examines existing theoretical perspectives on societal literacy programmes in terms of the scope that they provide for analyses that encompass the multi-levelled power relations that shape and influence dominant discourses on the relative value of literacy for both the individual and society

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Numerical forecasts of the atmosphere based on the fundamental dynamical and thermodynamical equations have now been carried for almost 30 years. The very first models which were used were drastic simplifications of the governing equations and permitting only the prediction of the geostrophic wind in the middle of the troposphere based on the conservation of absolute vorticity. Since then we have seen a remarkable development in models predicting the large-scale synoptic flow. Verification carried out at NMC Washington indicates an improvement of about 40% in 24h forecasts for the 500mb geopotential since the end of the 1950’s. The most advanced models of today use the equations of motion in their more original form (i.e. primitive equations) which are better suited to predicting the atmosphere at low latitudes as well as small scale systems. The model which we have developed at the Centre, for instance, will be able to predict weather systems from a scale of 500-1000 km and a vertical extension of a few hundred millibars up to global weather systems extending through the whole depth of the atmosphere. With a grid resolution of 1.5 and 15 vertical levels and covering the whole globe it is possible to describe rather accurately the thermodynamical processes associated with cyclone development. It is further possible to incorporate sub-grid-scale processes such as radiation, exchange of sensible heat, release of latent heat etc. in order to predict the development of new weather systems and the decay of old ones. Later in this introduction I will exemplify this by showing some results of forecasts by the Centre’s model.

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The paper provides a theoretical insight into bank regulation and the process of internationalisation by examining the concepts of regulatory push and market pull within the context of Japanese bank entry into London during the 1980s. Rugman and Verbeke's [(1998). Corporate strategy and international environmental policy. Journal of International Business Studies, 29(4), 819–833] Consistency of Home and Host Government Goals model is utilised to structure the discussion, which centres on a situation where there is a conflict of goals between multinational enterprises (MNEs) and the home government but goal alignment between MNEs and the host government. As such the paper examines a relatively under-researched aspect of internationalisation and concludes that in certain circumstances internationalisation can occur despite great ‘psychic distance’. The paper also argues that although bank regulation can lead to a conflict situation it can also be conducive to the development of a strong home base and the development of firm specific advantages.

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The UK house building sector is facing dual pressures to expand supply, along with delivering against tougher Building Regulations’ requirements, predominantly in the areas of sustainability. A review of current literature has highlighted that the pressures the UK house building industry is currently under may be having a negative impact on build quality, causing an increase in defects. A review and synthesis of the current defect literature with respect to new-build housing and the wider construction sector has found that the prevailing emphasis is limited to the classification, causes, pathology and statistical analysis of defects. There is thus a need to better understand the overall impact of individual defects on key stakeholders within the new-build housing defect detection and remediation process. As part of ongoing research to develop and verify a defect impact assessment rating system, this paper seeks to contribute to our understanding of the impact of individual defects from a key stakeholder perspective by undertaking the literature review and synthesis phase. The literature review identifies the three distinct, but interrelated, dominant impact factors: cost, disruption, and health and safety. By pulling the strands of defect literature together the theoretical lens and key stakeholder sampling strategy is formed as the basis for the subsequent impact weighting development phase.

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Olive fruits of three of the most important Spanish and Italian cultivars, 'Picual', `Hojiblanca' and 'Frantoio', were harvested at bi-weekly periods during three crop seasons to study their development and ripening process. Fresh and dry weights and ripening index were determined for fruit, while dry matter, oil and moisture contents were determined in both fruit and pulp (flesh). Fruit growth rate and oil accumulation were calculated. Each olive cultivar showed a different ripening pattern, 'Hojiblanca' being the last one to maturate. Fruit weight increased, decreasing its growth rate from the middle of November. Dry matter and moisture contents decreased during ripening in pulp and fruit, 'Hojiblanca' showing the highest values for both. Oil content, when expressed on a fresh weight basis, increased in all cultivars, although for the last time period showed variations due to climatic conditions. During ripening, oil content on a dry weight basis increased in fruit, but oil biosynthesis in flesh ceased from November. Olive fruits presented lower oil and higher dry matter contents in the year of lowest rainfall. Therefore fruit harvesting should be carried out from the middle of November in order to obtain the highest oil yield and avoid natural fruit drop. (C) 2004 Society of Chemical Industry.

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Purpose – The purpose of this paper is to explore and understand the process of successful introduction of total quality management (TQM) in Poland and the way in which it impacted on identity of Polish managers. Design/methodology/approach – The study is based on a combination of ethnographic research and repertory grid interviews. Findings – The process of TQM introduction and implementation is examined through the application of translation as a model incorporating cultural and socio-economical dimensions in addition to individual and organizational levels that shaped the development of TQM in Poland. It then draws on the idea of fantasy as theorized in Lacanian psychoanalysis in order to incorporate the unconscious element of translation process which is missing from Latour’s theorization and which forms an important aspect of adoption of new technology and the emergence of a new post-transition generation of managers in Poland. The paper argues that a complex combination of contextual factors, amongst them the notion of fantasy shaped the process of translation of TQM to Poland, the identity formation of Polish managers and to the emergence of a new post-transition generation of managers in Poland. Originality/value – This paper contributes to the literature on the post-command transition by illustrating this process through the fantasy of total quality management explored in a specific socio-cultural and geographical context and by combining the idea of Latour’s translation with Lacanian fantasy.

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Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations. As part of an overall strategy to determine a long-term treatment option for AMD, a pilot passive treatment plant was constructed in 1994 at Wheal Jane Mine in Cornwall, UK. The plant consists of three separate systems, each containing aerobic reed beds, anaerobic cell and rock filters, and represents the largest European experimental facility of its kind. The systems only differ by the type of pretreatment utilised to increase the pH of the influent minewater (pH <4): lime dosed (LD), anoxic limestone drain (ALD) and lime free (LF), which receives no form of pretreatment. Historical data (1994-1997) indicate median Fe reduction between 55% and 92%, sulphate removal in the range of 3-38% and removal of target metals (cadmium, copper and zinc) below detection limits, depending on pretreatment and flow rates through the system. A new model to simulate the processes and dynamics of the wetlands systems is described, as well as the application of the model to experimental data collected at the pilot plant. The model is process based, and utilises reaction kinetic approaches based on experimental microbial techniques rather than an equilibrium approach to metal precipitation. The model is dynamic and utilises numerical integration routines to solve a set of differential equations that describe the behaviour of 20 variables over the 17 pilot plant cells on a daily basis. The model outputs at each cell boundary are evaluated and compared with the measured data, and the model is demonstrated to provide a good representation of the complex behaviour of the wetland system for a wide range of variables. (C) 2004 Elsevier B.V/ All rights reserved.

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The CAFS search engine is a real machine in a virtual machine world; it is the hardware component of ICL's CAFS system. The paper is an introduction and prelude to the set of papers in this volume on CAFS applications. It defines The CAFS system and its context together with the function of its hardware and software components. It examines CAFS' role in the broad context of application development and information systems; it highlights some techniques and applications which exploit the CAFS system. Finally, it concludes with some suggestions for possible further developments. 'Search out thy wit for secret policies And we will make thee famous through the world' Henry VI, 1:3