824 resultados para Contractors Selection and appointment


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The aim of the research project was to gain d complete and accurate accounting of the needs and deficiencies of materials selection and design data, with particular attention given to the feasibility of a computerised materials selection system that would include application analysis, property data and screening techniques. The project also investigates and integrates the three major aspects of materials resources, materials selection and materials recycling. Consideration of the materials resource base suggests that, though our discovery potential has increased, geologic availability is the ultimate determinant and several metals may well become scarce at the same time, thus compounding the problem of substitution. With around 2- to 20- million units of engineering materials data, the use of a computer is the only logical answer for scientific selection of materials. The system developed at Aston is used for data storage, mathematical computation and output. The system enables programs to be run in batch and interactive (on-line) mode. The program with modification can also handle such variables as quantity of mineral resources, energy cost of materials and depletion and utilisation rates of strateqic materials. The work also carries out an in-depth study of copper recycling in the U.K. and concludes that, somewhere in the region of 2 million tonnes of copper is missing from the recycling cycle. It also sets out guidelines on product design and conservation policies from the recyclability point of view.

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The research was carried out in the Aviation Division of Dunlop Limited and was initiated as a search for more diverse uses for carbon/carbon composites. An assumed communication model of adoption was refined by introducing the concept of a two way search after making cross industry comparisons of supplier and consumer behaviour. This research has examined methods of searching for new uses for advanced technology materials. Two broad approaches were adopted. First, a case history approach investigated materials that had been in a similar oosition to carbon/carbon to see how other material producing firms had tackled the problem. Second, a questionnaire survey among industrialists examined: the role and identity of material decision makers in different sized firms; the effectiveness of various information sources and channels; and the material adoption habits of different industries. The effectiveness of selected information channels was further studied by monitoring the response to publicity given to carbon/carbon. A flow chart has been developed from the results of this research which should help any material producing firm that is contemplating the introduction of a new material to the world market. Further benefit to our understanding of the innovation and adoption of new materials would accrue from work in the followino areas: "micro" type case histories; understanding more fully the role of product champions or promoters; investigating the phase difference between incremental and radical type innovations for materials; examining the relationship between the adoption rate of new materials and the advance of technology; studying the development of cost per unit function methods for material selection; and reviewing the benefits that economy of scale studies can have on material developments. These are all suggested areas for further work.

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With the competitive challenge facing business today, the need to keep cost down and quality up is a matter of survival. One way in which wire manufacturers can meet this challenge is to possess a thorough understanding of deformation, friction and lubrication during the wire drawing process, and therefore to make good decisions regarding the selection and application of lubricants as well as the die design. Friction, lubrication and die design during wire drawing thus become the subject of this study. Although theoretical and experimental investigations have been being carried out ever since the establishment of wire drawing technology, many problems remain unsolved. It is therefore necessary to conduct further research on traditional and fundamental subjects such as the mechanics of deformation, friction, lubrication and die design in wire drawing. Drawing experiments were carried out on an existing bull-block under different cross-sectional area reductions, different speeds and different lubricants. The instrumentation to measure drawing load and drawing speed was set up and connected to the wire drawing machine, together with a data acquisition system. A die box connected to the existing die holder for using dry soap lubricant was designed and tested. The experimental results in terms of drawing stress vs percentage area reduction curves under different drawing conditions were analysed and compared. The effects on drawing stress of friction, lubrication, drawing speed and pressure die nozzle are discussed. In order to determine the flow stress of the material during deformation, tensile tests were performed on an Instron universal test machine, using the wires drawn under different area reductions. A polynomial function is used to correlate the flow stress of the material with the plastic strain, on which a general computer program has been written to find out the coefficients of the stress-strain function. The residual lubricant film on the steel wire after drawing was examined both radially and longitudinally using an SEM and optical microscope. The lubricant film on the drawn wire was clearly observed. Therefore, the micro-analysis by SEM provides a way of friction and lubrication assessment in wire drawing.

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This thesis looks at the UK onshore oil and gas production industry and follows the history of a population of firms over a fifteen-year period following the industry's renaissance. It examines the linkage between firm survival, selection pressures and adaptation responses at the firm level, especially the role of discretionary adaptation, specifically exploration and exploitation strategies.Taking a Realist approach and using quantitative and qualitative methods for triangulation on a new data base derived from archival data, as well as informant interviews, it tests seven hypotheses' about post-entry survival of firms. The quantitative findings suggest that firm survival within this industry is linked to discretionary adaptation, when measured at the firm level, and to a mixture of selection and adaptation forces when measured for each firm for each individual year. The qualitative research suggests that selection factors dominate. This difference in views is unresolved. However the small, sparse population and the nature of the oil and gas industry compared with other common research contexts such as manufacturing or service firms suggests the results be treated with caution as befits a preliminary investigation. The major findings include limited support for the theory that the external environment is the major determinant of firm survival, though environment components affect firms differentially; resolution of apparent literature differences relating to the sequencing of exploration and exploitation and potential tangible evidence of coevolution. The research also finds that, though selection may be considered important by industry players, discretionary adaptation appears to play the key role, and that the key survival drivers for thispopulation are intra-industry ties, exploitation experience and a learning/experience component. Selection has a place, however, in determining the life-cycle of the firm returning to be a key survival driver at certain ages of the firm inside the industry boundary.

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UK universities are accepting increasing numbers of students whose L1 is not English on a wide range of programmes at all levels. These students require additional support and training in English, focussing on their academic disciplines. Corpora have been used in EAP since the 1980s, mainly for research, but a growing number of researchers and practitioners have been advocating the use of corpora in EAP pedagogy, and such use is gradually increasing. This paper outlines the processes and factors to be considered in the design and compilation of an EAP corpus (e.g., the selection and acquisition of texts, metadata, data annotation, software tools and outputs, web interface, and screen displays), especially one intended to be used for teaching. Such a corpus would also facilitate EAP research in terms of longitudinal studies, student progression and development, and course and materials design. The paper has been informed by the preparatory work on the EAP subcorpus of the ACORN corpus project at Aston University. © 2007 Elsevier Ltd. All rights reserved.

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Purpose – This paper aims to develop an integrated analytical approach, combining quality function deployment (QFD) and analytic hierarchy process (AHP) approach, to enhance the effectiveness of sourcing decisions. Design/methodology/approach – In the approach, QFD is used to translate the company stakeholder requirements into multiple evaluating factors for supplier selection, which are used to benchmark the suppliers. AHP is used to determine the importance of evaluating factors and preference of each supplier with respect to each selection criterion. Findings – The effectiveness of the proposed approach is demonstrated by applying it to a UK-based automobile manufacturing company. With QFD, the evaluating factors are related to the strategic intent of the company through the involvement of concerned stakeholders. This ensures successful strategic sourcing. The application of AHP ensures consistent supplier performance measurement using benchmarking approach. Research limitations/implications – The proposed integrated approach can be principally adopted in other decision-making scenarios for effective management of the supply chain. Practical implications – The proposed integrated approach can be used as a group-based decision support system for supplier selection, in which all relevant stakeholders are involved to identify various quantitative and qualitative evaluating criteria, and their importance. Originality/value – Various approaches that can deal with multiple and conflicting criteria have been adopted for the supplier selection. However, they fail to consider the impact of business objectives and the requirements of company stakeholders in the identification of evaluating criteria for strategic supplier selection. The proposed integrated approach outranks the conventional approaches to supplier selection and supplier performance measurement because the sourcing strategy and supplier selection are derived from the corporate/business strategy.

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This research aims to examine the effectiveness of Soft Systems Methodology (SSM) to enable systemic change within local goverment and local NHS environments and to examine the role of the facilitator within this process. Checkland's Mode 2 variant of Soft Systems Methodology was applied on an experimental basis in two environments, Herefordshire Health Authority and Sand well Health Authority. The Herefordshire application used SSM in the design of an Integrated Care Pathway for stroke patients. In Sandwell, SSM was deployed to assist in the design of an Infonnation Management and Technology (IM&T) Strategy for the boundary-spanning Sandwell Partnership. Both of these environments were experiencing significant organisational change as the experiments unfurled. The explicit objectives of the research were: To examine the evolution and development of SSM and to contribute to its further development. To apply the Soft Systems Methodology to change processes within the NHS. To evaluate the potential role of SSM in this wider process of change. To assess the role of the researcher as a facilitator within this process. To develop a critical framework through which the impact of SSM on change might be understood and assessed. In developing these objectives, it became apparent that there was a gap in knowledge relating to SSM. This gap concerns the evaluation of the role of the approach in the change process. The case studies highlighted issues in stakeholder selection and management; the communicative assumptions in SSM; the ambiguous role of the facilitator; and the impact of highly politicised problem environments on the effectiveness of the methodology in the process of change. An augmented variant on SSM that integrates an appropriate (social constructivist) evaluation method is outlined, together with a series of hypotheses about the operationalisation of this proposed method.

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This, the first part of a two-part article on the discretionary powers of the courts to order a sale of the family home at the request of a secured creditor, considers whether the enactment of the Trusts of Land and Appointment of Trustees Act 1996 s.15 has led judicial decision making to favour the interests of the co-owner of the home. Reviews cases heard since the coming into force of the Act, looking at the factors taken into account when balancing the interests of the creditor and debtor, including the continued need to have a family home, the availability of other assets to pay off the debt, the size of the debt and the likelihood of repayment.

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Feelings of vulnerability in driving can be considered an emotional response to risk perception and the coping strategies adopted could have implications for continued mobility. In a series of focus groups with 48 licensed drivers aged 18-75 years, expressions of vulnerability in driver coping behaviours were examined. Despite feelings of vulnerability appearing low, qualitative thematic analysis revealed a complex array of coping strategies in everyday driving including planning, use of 'co-pilots', self-regulation, avoidance and confrontive coping, i.e. intentional aggression toward other road users. The findings inform future intervention studies to enable appropriate coping strategy selection and prolong independent mobility in older adults. © 2014 Elsevier Ltd. All rights reserved.

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Research on aphasia has struggled to identify apraxia of speech (AoS) as an independent deficit affecting a processing level separate from phonological assembly and motor implementation. This is because AoS is characterized by both phonological and phonetic errors and, therefore, can be interpreted as a combination of deficits at the phonological and the motoric level rather than as an independent impairment. We apply novel psycholinguistic analyses to the perceptually phonological errors made by 24 Italian aphasic patients. We show that only patients with relative high rate (>10%) of phonetic errors make sound errors which simplify the phonology of the target. Moreover, simplifications are strongly associated with other variables indicative of articulatory difficulties - such as a predominance of errors on consonants rather than vowels -but not with other measures - such as rate of words reproduced correctly or rates of lexical errors. These results indicate that sound errors cannot arise at a single phonological level because they are different in different patients. Instead, different patterns: (1) provide evidence for separate impairments and the existence of a level of articulatory planning/programming intermediate between phonological selection and motor implementation; (2) validate AoS as an independent impairment at this level, characterized by phonetic errors and phonological simplifications; (3) support the claim that linguistic principles of complexity have an articulatory basis since they only apply in patients with associated articulatory difficulties.

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Melt processing is a critical step in the manufacture of polymer articles and is even more critical when dealing with inhomogeneous polymer-clay nanocomposites systems. The chemical composition, and in particular the clay type and its organic modification, also plays a major contribution in determining the final properties and in particular the thermal and long-term oxidative stability of the resulting polymer nanocomposites. Proper selection and tuning of the process variable should, in principle, lead to improved characteristics of the fabricated product. With multiphase systems containing inorganic nanoclays, however, this is not straightforward and it is often the case that the process conditions are chosen initially to improve one or more desired properties at the expense of others. This study assesses the influence of organo-modified clays and the processing parameters (extrusion temperature and screw speed) on the rheological and morphological characteristics of polymer nanocomposites as well as on their melt and thermo-oxidative stability. Nanocomposites (PPNCs) based on PP, maleated PP and organically modified clays were prepared in different co-rotating twin-screw extruders ranging from laboratory scale to semi-industrial scale. Results show that the amount of surfactant present in similar organo-modified clays affects differently the thermo-oxidative stability of the extruded PPNCs and that changes in processing conditions affect the clay morphology too. By choosing an appropriate set of tuned process variables for the extrusion process it would be feasible to selectively fabricate polymer-clay nanocomposites, with the desired mechanical and thermo-oxidative characteristics. © 2013 Elsevier Ltd. All rights reserved.

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The purpose of this article is to evaluate the effectiveness of learning by doing as a practical tool for managing the training of students in "Library Management" at the ULSIT, Sofia, Bulgaria, by using the creation of project 'Data Base “Bulgarian Revival Towns” (CD), financed by Bulgarian Ministry of Education, Youth and Science (1/D002/144/13.10.2011) headed by Prof. DSc Ivanka Yankova, which aims to create new information resource for the towns which will serve the needs of scientific researches. By participating in generating the an array in the database through searching, selection and digitization of documents from these period, at the same time students get an opportunity to expand their skills to work effectively in a team, finding the interdisciplinary, a causal connection between the studied items, objects and subjects and foremost – practical experience in the field of digitization, information behavior, strategies for information search, etc. This method achieves good results for the accumulation of sustainable knowledge and it generates motivation to work in the field of library and information professions.

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We analyze a business model for e-supermarkets to enable multi-product sourcing capacity through co-opetition (collaborative competition). The logistics aspect of our approach is to design and execute a network system where “premium” goods are acquired from vendors at multiple locations in the supply network and delivered to customers. Our specific goals are to: (i) investigate the role of premium product offerings in creating critical mass and profit; (ii) develop a model for the multiple-pickup single-delivery vehicle routing problem in the presence of multiple vendors; and (iii) propose a hybrid solution approach. To solve the problem introduced in this paper, we develop a hybrid metaheuristic approach that uses a Genetic Algorithm for vendor selection and allocation, and a modified savings algorithm for the capacitated VRP with multiple pickup, single delivery and time windows (CVRPMPDTW). The proposed Genetic Algorithm guides the search for optimal vendor pickup location decisions, and for each generated solution in the genetic population, a corresponding CVRPMPDTW is solved using the savings algorithm. We validate our solution approach against published VRPTW solutions and also test our algorithm with Solomon instances modified for CVRPMPDTW.

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Volunteered Service Composition (VSC) refers to the process of composing volunteered services and resources. These services are typically published to a pool of voluntary resources. Selection and composition decisions tend to encounter numerous uncertainties: service consumers and applications have little control of these services and tend to be uncertain about their level of support for the desired functionalities and non-functionalities. In this paper, we contribute to a self-awareness framework that implements two levels of awareness, Stimulus-awareness and Time-awareness. The former responds to basic changes in the environment while the latter takes into consideration the historical performance of the services. We have used volunteer service computing as an example to demonstrate the benefits that self-awareness can introduce to self-adaptation. We have compared the Stimulus-and Time-awareness approaches with a recent Ranking approach from the literature. The results show that the Time-awareness level has the advantage of satisfying higher number of requests with lower time cost.

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Production of human mesenchymal stem cells for allogeneic cell therapies requires scalable, cost-effective manufacturing processes. Microcarriers enable the culture of anchorage-dependent cells in stirred-tank bioreactors. However, no robust, transferable methodology for microcarrier selection exists, with studies providing little or no reason explaining why a microcarrier was employed. We systematically evaluated 13 microcarriers for human bone marrow-derived MSC (hBM-MSCs) expansion from three donors to establish a reproducible and transferable methodology for microcarrier selection. Monolayer studies demonstrated input cell line variability with respect to growth kinetics and metabolite flux. HBM-MSC1 underwent more cumulative population doublings over three passages in comparison to hBM-MSC2 and hBM-MSC3. In 100 mL spinner flasks, agitated conditions were significantly better than static conditions, irrespective of donor, and relative microcarrier performance was identical where the same microcarriers outperformed others with respect to growth kinetics and metabolite flux. Relative growth kinetics between donor cells on the microcarriers were the same as the monolayer study. Plastic microcarriers were selected as the optimal microcarrier for hBM-MSC expansion. HBM-MSCs were successfully harvested and characterised, demonstrating hBM-MSC immunophenotype and differentiation capacity. This approach provides a systematic method for microcarrier selection, and the findings identify potentially significant bioprocessing implications for microcarrier-based allogeneic cell therapy manufacture. Large-scale production of human bone-marrow derived mesenchymal stem cells (hBM-MSCs) requires expansion on microcarriers in agitated systems. This study demonstrates the importance of microcarrier selection and presents a systematic methodology for selection of an optimal microcarrier. The study also highlights the impact of an agitated culture environment in comparison to a static system, resulting in a significantly higher hBM-MSC yield under agitated conditions.