81 resultados para Operation of landfill
Resumo:
An affirmative action programme, established by the Fair Employment (Northern Ireland) Act 1989, has been an important attempt to ensure ‘fair participation’ in employment for both Catholics and Protestants in Northern Ireland since 1990. The programme includes detailed monitoring of the community background of employees and requires employers to undertake remedial action where fair participation is not evident. Agreements were concluded between the regulatory agency and many employers specifying what affirmative action measures were required. Based on the annual monitoring returns submitted between 1990 and 2005, this article evaluates the effectiveness of the affirmative action programme in promoting fair employment participation using fixed effects models. The analysis shows that there has been a general shift towards workforce integration in Northern Ireland but the increase of under-represented groups in agreement concerns is greater than in concerns with no agreement. The success of agreements, however, is limited to certain industrial sectors and medium-sized enterprises.
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Landfills are the primary option for waste disposal all over the world. Most of the landfill sites across the world are old and are not engineered to prevent contamination of the underlying soil and groundwater by the toxic leachate. The pollutants from landfill leachate have accumulative and detrimental effect on the ecology and food chains leading to carcinogenic effects, acute toxicity and genotoxicity among human beings. Management of this highly toxic leachate presents a challenging problem to the regulatory authorities who have set specific regulations regarding maximum limits of contaminants in treated leachate prior to disposal into the environment to ensure minimal environmental impact. There are different stages of leachate management such as monitoring of its formation and flow into the environment, identification of hazards associated with it and its treatment prior to disposal into the environment. This review focuses on: (i) leachate composition, (ii) Plume migration, (iii) Contaminant fate, (iv) Leachate plume monitoring techniques, (v) Risk assessment techniques, Hazard rating methods, mathematical modeling, and (vi) Recent innovations in leachate treatment technologies. However, due to seasonal fluctuations in leachate composition, flow rate and leachate volume, the management approaches cannot be stereotyped. Every scenario is unique and the strategy will vary accordingly. This paper lays out the choices for making an educated guess leading to the best management option.
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A new variant of Class-EF power amplifier (PA), the so-called third-harmonic-peaking Class-EF, is presented. It inherits a soft-switching operation from the Class-E PA and a low peak switch voltage from the Class-F PA. More importantly, the new topology allows operations at higher frequencies and permits deployment of large transistors which is normally prohibited since they are always accompanied with high output capacitances. Using a simple transmission-line load network, the PA is synthesized to satisfy Class-EF impedances at fundamental frequency, third harmonic, and all even harmonics as well as to simultaneously provide an impedance matching to 50-Ω load.
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Design and operation of Fe0 permeable reactive barriers (PRBs) can be improved by understanding the long-term mineralogical transformations that occur within PRBs. Changes in mineral precipitates, cementation, and corrosion of Fe0 filings within an in situ pilot-scale PRB were examined after the first 30 months of operation and compared with results of a previous study of the PRB conducted 15 months earlier using X-ray diffraction and scanning electron microscopy employing energy dispersive X-ray and backscatter electron analyses. Iron (oxy)hydroxides, aragonite, and maghemite and/or magnetite occurred throughout the cores collected 30 mo after installation. Goethite, lepidocrocite, mackinawite, aragonite, calcite, and siderite were associated with oxidized and cemented areas, while green rusts were detected in more reduced zones. Basic differences from our last detailed investigation include (i) mackinawite crystallized from amorphous FeS, (ii) aragonite transformed into calcite, (iii) akaganeite transformed to goethite and lepidocrocite, (iv) iron (oxy)hydroxides and calcium and iron carbonate minerals increased, (v) cementation was greater in the more recent study, and (vi) oxidation, corrosion, and disintegration of Fe0 filings were greater, especially in cemented areas, in the more recent study. If the degree of corrosion and cementation that was observed from 15 to 30 mo after installation continues, certain portions of the PRB (i.e., up-gradient entrance of the ground water to the Fe0 section of the PRB) may last less than five more years, thus reducing the effectiveness of the PRB to mitigate contaminants.
The Impact of the Recent Economic Recession on the operation of the NEC Contract in Northern Ireland
Resumo:
In May 2006, the NEC contract was introduced as the preferred contract for Northern Ireland public sector works. This was subsequently followed by the 2007 economic crash and ensuing recession, which continues to affect the Northern Ireland Construction Industry, to a greater extent than the remainder of the United Kingdom (UK). However, use of the NEC contract has increased during this period, particularly in the public sector. There has been debate in the literature regarding the impact of the NEC contract on adversarial behaviour, but little consideration of the impact of external economic factors on the use of the NEC contract. Using a sequential mixed method approach, the study aims to fill this gap in knowledge, through examination of the impact the economic downturn has had on the operation of the NEC contract in Northern Ireland. Qualitative and quantitative findings show that the demands placed by the NEC contract, and the effects of the economic recession, have exerted opposing forces contract implementation, thus hindering its execution. The findings can lead to a deeper understanding, in the context of both industry and academia, of situations where a lack of resources may negatively impact the operation of the NEC contract.
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Desiccation crack formation is a key process that needs to be understood in assessment of landfill cap performance under anticipated future climate change scenarios. The objectives of this study were to examine: (a) desiccation cracks and impacts that roots may have on their formation and resealing, and (b) their impacts on hydraulic conductivity under anticipated climate change precipitation scenarios. Visual observations, image analysis of thin sections and hydraulic conductivity tests were carried out on cores collected from two large-scale laboratory trial landfill cap models (∼80 × 80 × 90 cm) during a year of four simulated seasonal precipitation events. Extensive root growth in the topsoil increased percolation of water into the subsurface, and after droughts, roots grew deep into low-permeability layers through major cracks which impeded their resealing. At the end of 1 year, larger cracks had lost resealing ability and one single, large, vertical crack made the climate change precipitation model cap inefficient. Even though the normal precipitation model had developed desiccation cracks, its integrity was preserved better than the climate change precipitation model.
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Cross-border (North/South) co-operation between the Republic of Ireland and Northern Ireland was an indelible feature of the form of governance provided by the Belfast Good Friday Agreement (1998). Previous efforts to establish North/South co-operation had all foundered but the establishment and initial operation of the Agreement's cross-border institutions proved to be uncontroversial. However, during its implementation, other areas of the Agreement gave Ulster unionists more pressing cause for concern. These areas of concern included the release of paramilitary prisoners, police reform, the 'decommissioning' of Irish Republican Army (IRA) weaponry, and the unionist perception that the 'Britishness of Northern Ireland' was being actively eroded. These concerns served to emphasise and strengthen political and cultural borders between communities at a regional and local level within Northern Ireland. They also threatened the pro-Agreement unionists' contestation of unionist ideological orthodoxy, a contestation that was undertaken in an attempt to adapt the Ulster unionist identity to the shifting thresholds of the state.
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Background: TORCH (Towards a Revolution in COPD Health) is an international multicentre, randomised, placebo-controlled clinical trial of inhaled fluticasone propionate/salmeterol combination treatment and its monotherapy components for maintenance treatment of moderately to severely impaired patients with chronic obstructive pulmonary disease (COPD). The primary outcome is all-cause mortality. Cause-specific mortality and deaths related to COPD are additional outcome measures, but systematic methods for ascertainment of these outcomes have not previously been described. Methods: A Clinical Endpoint Committee (CEC) was tasked with categorising the cause of death and the relationship of deaths to COPD in a systematic, unbiased and independent manner. The key elements of the operation of the committee were the use of predefined principles of operation and definitions of cause of death and COPD-relatedness; the independent review of cases by all members with development of a consensus opinion; and a substantial infrastructure to collect medical information. Results: 911 deaths were reviewed and consensus was reached in all. Cause-specific mortality was: cardiovascular 27%, respiratory 35%, cancer 21%, other 10% and unknown 8%. 40% of deaths were definitely or probably related to COPD. Adjudications were identical in 83% of blindly re-adjudicated cases ( = 0.80). COPD-relatedness was reproduced 84% of the time ( = 0.73). The CEC adjudication was equivalent to the primary cause of death recorded by the site investigator in 52% of cases. Conclusion: A CEC can provide standardised, reliable and informative adjudication of COPD mortality that provides information which frequently differs from data collected from assessment by site investigators.
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This paper presents the basic physics underlying the operation of electron beam ion traps and sources, with the machine physics underlying their operation being described in some detail. Predictions arising from this description are compared with some diagnostic measurements.
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The tailpipe emissions from automotive engines have been subject to steadily reducing legislative limits. This reduction has been achieved through the addition of sub-systems to the basic four-stroke engine which thereby increases its complexity. To ensure the entire system functions correctly, each system and / or sub-systems needs to be continuously monitored for the presence of any faults or malfunctions. This is a requirement detailed within the On-Board Diagnostic (OBD) legislation. To date, a physical model approach has been adopted by me automotive industry for the monitoring requirement of OBD legislation. However, this approach has restrictions from the available knowledge base and computational load required. A neural network technique incorporating Multivariant Statistical Process Control (MSPC) has been proposed as an alternative method of building interrelationships between the measured variables and monitoring the correct operation of the engine. Building upon earlier work for steady state fault detection, this paper details the use of non-linear models based on an Auto-associate Neural Network (ANN) for fault detection under transient engine operation. The theory and use of the technique is shown in this paper with the application to the detection of air leaks within the inlet manifold system of a modern gasoline engine whilst operated on a pseudo-drive cycle. Copyright © 2007 by ASME.
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This article describes the work of Newry Student Unit which operates in the Southern Health and Social Care Trust. The background to the unit is outlined and its development is discussed in the context of practice learning provision in Northern Ireland. The operation of the unit in providing Family and Child Care practice learning opportunities (PLOs) for student social workers is outlined and findings from evaluation questionnaires completed by students, college tutors and team leaders are presented. The paper highlights both the advantages and disadvantages of this model of PLO provision and concludes that it is a valuable resource for practice learning. Proposals for the development of the unit are discussed and it is suggested that the model has the potential be replicated in other areas of Northern Ireland.