Reliability assessment approach through geospatial mapping for offshore wind energy

To meet the increased energy demands, uphold commitments made in the Paris agreement and provide energy security to its consumers, the United Kingdom is rapidly expanding its wind energy industry at offshore locations. While harnessing the improved wind resource further offshore, the industry has faced reliability challenges in the dynamic marine environment which contribute to an increase in the cost of energy. This thesis promotes the argument for location - intelligent decisions in the industry by developing a methodology to allocate a combined risk - return performance metric for offshore locations. In the absence of comprehensive spatially distributed field reliability data for offshore wind turbines, the limit state design methodology is employed to model structural damage. Exposed to stochastic loading from wind and wave regimes, offshore wind turbines are fatigue-critical structures. The aero- and hydro-dynamic loads at representative sites across eight sub-regions in the UK continental shelf are quantified by processing modelled metocean data through established aero-hydro-servo-elastic design tools. These simulated loads and the inherent material fatigue properties provide site-specific lifetime accumulated damage. Normalising this damage based on the potential energy production at each site provides an improved understanding of the feasibility of the sub-region for offshore wind deployment. Results indicate that although sheltered sub-regions display lower resource potential, they have the benefit of the reduced associated structural damage compared to more dynamic locations. A similar observation is made when the methodology is employed on a larger scale incorporating the UK continental shelf and its adjoining areas. Furthermore, not only the energy potential displays an increase with an increase in distance-to-shore, but also the damage per unit energy produced. The research outcomes of this project are useful for identifying the potential of structural reserves for lifetime extension considerations as more turbines reach their design lifetimes. Additionally, it may be used to inform design parameters, optimise siting of future installations and determine suitable maintenance strategies to improve the economic viability of offshore wind

Labour Market Dynamics in Pakistan: Evidence from the Longitudinal Data

The bulk of research on labour market conditions in Pakistan has concentrated on the economic activity rate, the number of employed persons, or the unemployment rate at a particular point in time. These stock measures of labour market situation are useful from a policy viewpoint as they give a broad indication of the dimension of the problem. For example, the recent labour force surveys show an increase in the level of open unemployment from 5.9 percent in 1997-98 to 7.8 percent in 1999-2000 [Pakistan (2001)]. There is also an emerging consensus that during the 1990s poverty has increased at the national as well as for rural and urban areas of the country [Qureshi and Arif (2001)]. Labour market is considered as the main route for establishing the link between macro policies, the resulting GDP growth and poverty alleviation [Rahman (2002)]. Interim Poverty Reduction Strategy Paper (IPRSP) and other development plans have suggested various targets of employment creation for poverty reduction. The stock measures of labour market conditions, such as unemployment rate, are considered to be inadequate from the viewpoint of developing appropriate policy responses. There is a need to gain further insights by examining the structure of labour market in terms of its dynamic components: these being the turnover of persons into and out of the labour force and turnover into and out of employment and unemployment pools

Intention to use e-government services among the academic staff in Saudi universities

E-government diffusion and usage is a global topic that concerns many countries worldwide. E-government is a way for providing services of government over online channels of communication to its citizens. Saudi Arabia has implemented a program of e-government in 2005 to encourage performance of public sectors through acquiring the benefits of Information Communication Technology (ICT) advances. This study focuses on the factors that influence intention to use e-government among the academic staff in Saudi Arabia. In addition, this study is to identify the mediating role of e-government awareness on the relationships between social influence, trust of internet and trust in intermediaries and intention to use e-government and the mediating role of perceived risk on the relationships between trust of internet and trust in intermediaries and intention to use e-government. Based on the Theory of Planned Behaviour (TPB), this study integrated these factors to examine their influences on intention to use e-government. This study utilized a quantitative approach using a survey to reflect consumers’ perspectives towards e-government usage. To examine the hypothesized model, the data were collected from the academic staff working in Saudi public universities. This study employed Partial Least Squares techniques to confirm the validity and reliability of the measurement model and to examine the structural relationships. The findings of the study confirmed the influences of social influence, e-government awareness, trust in intermediary and perceived risk on intention to use e-government. Further, awareness of e-government is influenced by social influence, trust in Internet and trust in intermediary and mediates the relationship between these factors and intention to use e-government. Trust in Internet factor emerged as significant predictor of consumers’ risk perceptions and mediates the relationship between this factor and intention to use e-government. This study has important implications for e-government practitioners, researchers and policy decision makers interested in the implementation of e-governmen

Correlation of Atrial Fibrillation with Left Atrial Volume in Patients with Mitral Stenosis. a Single Centre Study From Pakistan

Background: Rheumatic heart disease has a strong association with mitral valve stenosis. Atrial fibrillation is one of the most common complications of this condition and is a poor prognostic factor. Early detection and prompt management of atrial fibrillation can help to improve the quality of life and increase the life expectancy of the patients. We carried out this study to investigate the significance of left atrial volumetric changes in mitral stenosis and its correlation with atrial fibrillation. Methodology: We audited the data of 60 patients of rheumatic heart disease who had mitral valve stenosis. The patients were randomized into atrial fibrillation (Group A) and normal sinus rhythm (Group B). We conducted this cross-sectional analytical study at Cardiology Department, Mayo Hospital, Lahore, from 1st February 2017 to 31st January 2018. We only included those patients who consented to be a part of this study and fulfilled our predefined inclusion criteria. Left atrial volume was measured by prolate ellipse method and biplane methods on echocardiography. The Data was analyzed on SPSS v20. Results: Sixty patients were included in the study. Among the subjects, thirty-six (60%) were males, and twenty-four (40%) were females. Atrial fibrillation was noted in 43.33% of the patients of mitral valve stenosis. There was a marked difference in the mean volume of the left atrium among the two groups. We observed that the mean area of the mitral valve for Group A patients was larger than that of patients in Group B. Our study showed an inverse correlation between left atrial volume and mitral valve area among Group A patients. Conclusion: Patients of mitral stenosis are at an increased risk of developing atrial fibrillation if the left atrial volume is increasing. All patients with mitral stenosis should have routine echocardiography & measurement of left atrial volumes, so that proper treatment can be started if the left atrial volume is increasing, to prevent atrial fibrillation

Reliability assessment of tidal stream energy: significance for large-scale deployment in the UK

This is the author accepted manuscript. The final version is available from CRC PressThe UK has ambitious plans to harness its available tidal stream resource, estimated at 95TWh/year by The Crown Estate (2013). The economic viability of large-scale deployments will be largely governed by aspects of plant availability, including reliability. Using available information on environmental parameters of (pre-) consented sites across the UK, this paper explores subassembly target reliability levels for tidal stream devices. Reliability models of devices are investigated to establish the influence of environmental site conditions with regard to underlying subassembly failure rates and target reliability levels. Hence, a relia-bility-focussed perspective on the planned deployments is presented

Environmental management accounting implementation in environmentally sensitive industries in Malaysia

This research investigates the level of EMA implementation in companies within environmentally sensitive industries in Malaysia, as well as gaining insights into pressures for implementation. It was found that there are elements of environmental-related management accounting within some of the organizations in which interviews were conducted. Implementation was driven by a motivation to reduce costs rather than environmental conservation. Apart from that, companies' reactions to environmental issues stem from pressures from customers who demand environmentally sensitive workplaces, procedures and processes in the companies with which they are in business

Ocular manifestations of graft-versus-host disease

AbstractAllogeneic hematopoietic stem cell transplantation (HSCT) has evolved over the past two decades to become the standard of care for hematologic and lymphoid malignancies. Major ocular complications after allogeneic HSCT have been increasing in number and severity. Graft-versus-host disease (GVHD) remains a major cause of ocular morbidity after allogeneic HSCT. The main objective of this review is to elucidate the ocular complications in patients developing GVHD following HSCT.Ocular complications secondary to GVHD are common and include dry eye syndrome, acquisition of ocular allergy from donors with allergic disorders. Eyelid changes may occur in GVHD leading to scleroderma-like changes. Patients may develop poliosis, madarosis, vitiligo, lagophthalmos, and entropion. The cornea may show filamentary keratitis, superficial punctate keratitis, corneal ulcers, and peripheral corneal melting which may lead to perforation in severe cases. Scleritis may also occur which can be anterior or posterior. Keratoconjunctivis sicca appears to be the most common presentation of GVHD. The lacrimal glands may be involved with mononuclear cell infiltration of both the major and accessory lacrimal glands and decrease in tear production.Severe dry eye syndrome in patients with GVHD may develop conjunctival scarring, keratinization, and cicatrization of the conjunctiva.Therapy of GVHD includes systemic immunosuppression and local therapy. Surgical treatment in refractory cases includes surgical intervention to improve the manifestation of GVHD of the eye. This may include tarsorrhapy, prose lenses, punctal occlusions and corneal transplantation

Properties of Hardened Concrete Containing CBA Ash and FCS as Partial Sand Replacement

A large amount of coal bottom ash (CBA) is being discharged from thermal power plants and has been making serious environmental pollution. Meanwhile, fine coconut shell (FCS) is an agricultural waste and is available in plentiful quantities throughout tropical countries worldwide. In many countries, coconut shell is subjected to open burning which contributes significantly to CO2 and methane emissions. Both of these materials are essential to utilize the CBA and FCS to reduce environmental pollution. Therefore, this study aims to determine the properties of combination of these materials as partial sand replacement. CBA is slow in pozzolanic activity of coal bottom ash which is suitable for partial replacement sand. Meanwhile, FCS is lightweight material with high density in porous filler.  Concrete designed for 30 MPa strength at 28 days curing age and 0.50 of water-cement ratio in this study. The percentage of CBA used is 5%, 10%, 15% and 20%, while the percentage of FCS is 2%, 4%, 6% and 8% where it has been replaced by volume replacement. The specimens were cured in water for 7, 28, 56 and 90 days curing ages before compressive and splitting tensile strength test are conducted. It can be concluded that the density of the concrete decreased, compressive and splitting tensile strength show the improvement with the utilization of CBA and FCS in concrete. In addition, the percentage of water absorption increased as both of CBA and FCS absorb the water. This study shows that an optimum percentage of CBA found is 10% and FCS is 6% for this study