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The effect of acidity and salinity level in erosion-corrosion performance of metals
Get PDFThe current study comprises an extended investigation of the effect of acidity and salinity levels on the erosion-corrosion behaviour of metallic materials used in the mining industry. In such environments, the level of both acidity and salinity significantly affects the alloys used for manufacturing either critical parts of pumps or pipelines that are subject to erosion-corrosion. The experimental approach consists of a detailed analysis with regards to the tested materials microstructure and their erosion-corrosion performance. In addition, the synergistic effects between erosion, sliding abrasion and corrosion were investigated by implementing electrochemical techniques. The post-test analysis enabled the evaluation of the materials behaviour in different hydrodynamic regions. The scope of the tested materials focused on white cast irons with either austenitic or martensitic matrix and various carbide volume fractions, whilst their erosion-corrosion performance was compared with commercial grades of stainless steel with austenitic and martensitic structure. The findings demonstrate that in neutral pH conditions and seawater the martensitic matrix and eutectic carbides are the optimum combination for the white cast irons, which are superior over the stainless steels. The increase of carbide volume fraction in conjunction with the presence of coarse/large carbides impair the erosion-corrosion performance of white cast irons. In acidic testing environment, the austenitic alloys exhibit substantially lower volume loss than the martensitic materials and this is associated with the enhanced corrosion resistance of austenitic structure. The current study extends to erosion-corrosion analysis in both neutral and very strong acidic conditions, in which two innovative alloys precipitated by σ-phase were investigated. The results illustrate that the controlled formation of σ-phase is beneficial in terms of erosion-corrosion. Furthermore, by increasing the salinity, the corrosion rates and the overall volume loss are higher on martensitic alloys with moderate corrosion resistance, whilst on austenitic or martensitic alloys with relatively good corrosion resistance the salinity has no effect.The current study comprises an extended investigation of the effect of acidity and salinity levels on the erosion-corrosion behaviour of metallic materials used in the mining industry. In such environments, the level of both acidity and salinity significantly affects the alloys used for manufacturing either critical parts of pumps or pipelines that are subject to erosion-corrosion. The experimental approach consists of a detailed analysis with regards to the tested materials microstructure and their erosion-corrosion performance. In addition, the synergistic effects between erosion, sliding abrasion and corrosion were investigated by implementing electrochemical techniques. The post-test analysis enabled the evaluation of the materials behaviour in different hydrodynamic regions. The scope of the tested materials focused on white cast irons with either austenitic or martensitic matrix and various carbide volume fractions, whilst their erosion-corrosion performance was compared with commercial grades of stainless steel with austenitic and martensitic structure. The findings demonstrate that in neutral pH conditions and seawater the martensitic matrix and eutectic carbides are the optimum combination for the white cast irons, which are superior over the stainless steels. The increase of carbide volume fraction in conjunction with the presence of coarse/large carbides impair the erosion-corrosion performance of white cast irons. In acidic testing environment, the austenitic alloys exhibit substantially lower volume loss than the martensitic materials and this is associated with the enhanced corrosion resistance of austenitic structure. The current study extends to erosion-corrosion analysis in both neutral and very strong acidic conditions, in which two innovative alloys precipitated by σ-phase were investigated. The results illustrate that the controlled formation of σ-phase is beneficial in terms of erosion-corrosion. Furthermore, by increasing the salinity, the corrosion rates and the overall volume loss are higher on martensitic alloys with moderate corrosion resistance, whilst on austenitic or martensitic alloys with relatively good corrosion resistance the salinity has no effect
Building 'in' tenant energy performance : a new method of benchmarking variations in patterns of use by building tenure
No full textTo deliver the overarching EU Energy Performance of Building Directive energy reduction targets and deliver efficient building energy performance in practice, improved methods of communicating building performance evaluation, at design and operational stage, are necessary to review (i) the impact of variation in patterns of use and its effect on overall building performance and (ii) whether the building or the occupants patterns of use are operating effectively.;The thesis aims to make contributions in these areas. The approach taken was to make the hypothesis that a new method could be developed, to ensure a fairer and more informed demonstration of a tenant's patterns of use on energy performance, which could be integrated into the existing design and evaluation process.;The new method is developed through (i) consideration of the building energy performance evaluation field and reference to current regulatory processes and guidance (ii) tested in application through evaluating the impact of variations in patterns of use on energy performance between building tenures, sharing the same building (ii) furthermore by simulating and calculating potential impacts of extreme usage patterns by demonstrating how the building would perform under minimum and maximum scenarios and (iv) critically evaluating integration into the existing energy performance evaluation process.;The new method is defined from adjustments to the articulation of occupancy capacity present in regulatory and compliance calculations, which are offered and critically reviewed. The adjustments are (i) to assess tenure energy performance scenarios with new minimum and maximum tenure occupancy load factor benchmarks (ii) measure aggregated energy use of a full-time employee defined by tenure occupancy load factors and (iii) determine occupant and building ineffective practices.;The new method of evaluating a building's energy performance range takes into account variations in patterns of use, which exist between building tenant groups to identify where the tenant group sits in relation to a set of 5 predefined benchmarks to evaluate if the building is performing badly or if in fact, it's the practices of the building users, which are inefficient.;The research demonstrates that variations in patterns of use can account for a 44% increase in energy use per m2 and 112% increase per person in commercial offices. This illustrates that the current method of predicting energy consumption patterns based on fixed occupancy and set hours of operation for a sole tenant is misleading and allows for a large margin of uncertainty unless the exact patterns of use can be established at the design stage.;The outcome of the new method is intended to contribute energy efficient building design and operation to improve energy resource efficiency in practice. This results in a new method, integrated throughout the lifecycle of the building, to support green tenancy agreements, such as the Tenant Energy Efficiency Regulations 2018 and other energy performance contracts.;The integration of the proposed new method into the existing regulatory and guidance methodologies is proposed and demonstrated. The development of the method is focused on a specific building purpose group; yet, the method could be reviewed and applied to other building groups with appropriate methods and metrics. The thesis provides foundation and motivation for further research in this area.To deliver the overarching EU Energy Performance of Building Directive energy reduction targets and deliver efficient building energy performance in practice, improved methods of communicating building performance evaluation, at design and operational stage, are necessary to review (i) the impact of variation in patterns of use and its effect on overall building performance and (ii) whether the building or the occupants patterns of use are operating effectively.;The thesis aims to make contributions in these areas. The approach taken was to make the hypothesis that a new method could be developed, to ensure a fairer and more informed demonstration of a tenant's patterns of use on energy performance, which could be integrated into the existing design and evaluation process.;The new method is developed through (i) consideration of the building energy performance evaluation field and reference to current regulatory processes and guidance (ii) tested in application through evaluating the impact of variations in patterns of use on energy performance between building tenures, sharing the same building (ii) furthermore by simulating and calculating potential impacts of extreme usage patterns by demonstrating how the building would perform under minimum and maximum scenarios and (iv) critically evaluating integration into the existing energy performance evaluation process.;The new method is defined from adjustments to the articulation of occupancy capacity present in regulatory and compliance calculations, which are offered and critically reviewed. The adjustments are (i) to assess tenure energy performance scenarios with new minimum and maximum tenure occupancy load factor benchmarks (ii) measure aggregated energy use of a full-time employee defined by tenure occupancy load factors and (iii) determine occupant and building ineffective practices.;The new method of evaluating a building's energy performance range takes into account variations in patterns of use, which exist between building tenant groups to identify where the tenant group sits in relation to a set of 5 predefined benchmarks to evaluate if the building is performing badly or if in fact, it's the practices of the building users, which are inefficient.;The research demonstrates that variations in patterns of use can account for a 44% increase in energy use per m2 and 112% increase per person in commercial offices. This illustrates that the current method of predicting energy consumption patterns based on fixed occupancy and set hours of operation for a sole tenant is misleading and allows for a large margin of uncertainty unless the exact patterns of use can be established at the design stage.;The outcome of the new method is intended to contribute energy efficient building design and operation to improve energy resource efficiency in practice. This results in a new method, integrated throughout the lifecycle of the building, to support green tenancy agreements, such as the Tenant Energy Efficiency Regulations 2018 and other energy performance contracts.;The integration of the proposed new method into the existing regulatory and guidance methodologies is proposed and demonstrated. The development of the method is focused on a specific building purpose group; yet, the method could be reviewed and applied to other building groups with appropriate methods and metrics. The thesis provides foundation and motivation for further research in this area
A human interaction approach to networking capabilities and international opportunity enactment : an exploration of German high-technology manufacturing SMEs
Get PDFThis study addresses recent calls to advance knowledge on networking capability (Mitrega et al., 2012; Grünberg-Bochard and Kreis-Hoyer, 2009; Sullivan Mort and Weerawardena, 2006) and international opportunity (Mamun, 2015; Mainela et al., 2014). Its rationale is to explore network capabilities in the enactment of international opportunities in German high-technology manufacturing SMEs in business-to-business markets. The study focuses on these capabilities and their contribution to the successful international expansion of such firms at three different business relationship levels: inter-personal, inter-organisational and country-level. Three objectives are formulated: 1) to explore the networking capabilities for German high-technology manufacturing SMEs in the successful identification and enactment of international opportunities; 2) to identify key factors that contribute to the successful enactment of international opportunities for such firms at inter-personal, inter-organisational and country levels; and 3) to develop theoretical integration between networking capabilities and international expansion of these firms. These objectives are addressed through a qualitative methodology, comprising 17 face-to-face interviews with key decision-makers and supplementary discussions with industry-experts. The originality of the study lies in its effort to integrate insights from international opportunity research with the networking capability concept. This study identifies the networking capabilities of Personal Interaction Capabilities, Interpersonal Liking Capabilities, Trust Capabilities, Capabilities to Maintain Relationships, Knowledge Exchange Capabilities, Pride as well as Cultural Familiarity; and explores the typical entrepreneurial behaviour key decision-makers display in their network relationships and corresponding human interactions. The study contributes to networking capability research by identifying a set of capabilities essential for the successful enactment of international opportunities. It also advances knowledge on how, once identified, international opportunities are enacted in dynamic and fast-moving high technology markets. The study also proposes some managerial implications in relation to entrepreneurial behaviour in networks, as well as the utilisation and development of such capabilities, and identifies some areas for future research.This study addresses recent calls to advance knowledge on networking capability (Mitrega et al., 2012; Grünberg-Bochard and Kreis-Hoyer, 2009; Sullivan Mort and Weerawardena, 2006) and international opportunity (Mamun, 2015; Mainela et al., 2014). Its rationale is to explore network capabilities in the enactment of international opportunities in German high-technology manufacturing SMEs in business-to-business markets. The study focuses on these capabilities and their contribution to the successful international expansion of such firms at three different business relationship levels: inter-personal, inter-organisational and country-level. Three objectives are formulated: 1) to explore the networking capabilities for German high-technology manufacturing SMEs in the successful identification and enactment of international opportunities; 2) to identify key factors that contribute to the successful enactment of international opportunities for such firms at inter-personal, inter-organisational and country levels; and 3) to develop theoretical integration between networking capabilities and international expansion of these firms. These objectives are addressed through a qualitative methodology, comprising 17 face-to-face interviews with key decision-makers and supplementary discussions with industry-experts. The originality of the study lies in its effort to integrate insights from international opportunity research with the networking capability concept. This study identifies the networking capabilities of Personal Interaction Capabilities, Interpersonal Liking Capabilities, Trust Capabilities, Capabilities to Maintain Relationships, Knowledge Exchange Capabilities, Pride as well as Cultural Familiarity; and explores the typical entrepreneurial behaviour key decision-makers display in their network relationships and corresponding human interactions. The study contributes to networking capability research by identifying a set of capabilities essential for the successful enactment of international opportunities. It also advances knowledge on how, once identified, international opportunities are enacted in dynamic and fast-moving high technology markets. The study also proposes some managerial implications in relation to entrepreneurial behaviour in networks, as well as the utilisation and development of such capabilities, and identifies some areas for future research
Quantification of uncertainty in sub-sea acoustic measurement, and validation of wave-current kinematics, at a tidal energy site
Get PDFStrathclyde theses - ask staff. Thesis no. : T15017As developers seek to convert the energy of the tides into electricity, sub-sea turbines must be designed to perform well in increasingly harsh conditions. Such energetic seas have historically been avoided, hence measurements taken below the surface in strong tidal currents and large waves are relatively few, and the theory behind these interactions is underdeveloped. This thesis compares measurements of subsurface velocity taken in the field, at a UK site proposed for development, to the velocity outputs of a model capable of combining waves and currents in a number of ways. In particular the interaction between waves and currents is investigated.The methodology incorporates a novel virtual velocity measurement instrument to measure the model ow,replicating the physical instruments used at sea, such that direct comparisons can be made between the two data-sets. Model and field velocities show good agreement across a range of current speeds and wave heights,with a range of metrics used to demonstrate the suitability of the model, based on linear wave-current theory,for this site. The wave-current interaction module is calibrated, with linear superposition of wave and current velocities proving a suitable representation of field velocities. Calculation of a dispersion relationship affected by mean current velocity marginally improves calibration with field data. Analysis of other sites using the tools developed will further validate this type of model, which in combination with blade element momentum theory,is able to predict pre-construction site specific loads on tidal turbines.Doppler Current Profilers (DCPs) are able to measure subsurface water particle kinematics and sea surface elevation simultaneously, however assumptions made by these instruments jeopardise detail when recording in highly energetic seas, particularly where waves and turbulent tidal currents combine. Models developed to optimise the design of tidal turbines require correct site specific inputs to accurately reflect the conditions that a turbine may encounter through its lifetime, moreover, the kinematics of these models must be accurately validated. To overcome the limitations in DCP measurements a 'Virtual' Doppler Current Profiler (VDCP)is developed (Crossley et al. 2017), enabling quantification of error in site characteristics, and 'like for like'comparisons of field and model kinematics that has never previously been documented. The numerical model developed incorporates tidal currents, waves and turbulence combined linearly to output subsurface velocity based on conditions from the field which have been averaged over ten minute intervals. The inputs are simple,time averaged characteristics (current magnitude, direction, and profile; wave height, period and direction,turbulence intensity and turbulence length-scale) and the model outputs velocities over a two dimensional grid that develops with time. The VDCP samples this ow as if it were the very instrument in the field that recorded the data used for validation. Taking into account the heading, pitch and roll of the instrument a data set directly comparable to that measured in the field is generated.The VDCP is initially used in quantifying error in wave and turbulence statistics, demonstrating a phase dependency of velocity measurements averaged between beams and providing a theoretical error for wave and turbulence characteristics sampled under a range of conditions, in order to improve tidal site characterisation. Spectral moments of the subsurface longitudinal wave orbital velocities recorded by the VDCP can be between 0.1 and 9 times those measured at a point for certain turbulent current conditions, turbulence intensity measurements may vary between 0.2 and 1.5 times the input value in low wave conditions and turbulence length scale calculations can vary by over ten times the input value, dependent on both current and wave conditions.The methodology can be used to determine a theoretical error in any site characterisation parameter for any set of wave, current and turbulence conditions.Results of the model validation using the VDCP show that the tidal ow model, and in particular the newly developed wave-current interaction module, is effective in simulating field subsurface velocities over a range of depths, for waves of up to 3m significant wave height and currents of up to 3.5ms1.;The model is effective in reproducing the wave climate using both measured and modelled surface elevation spectra, and tests, with marginal improvements, the effect of modifying the dispersion equation to account for currents. Field and model velocities compare well over the frequency range dominated by waves, showing only small underestimations in model standard deviations with respect to those from field data, at depths close to the sea surface. At the low frequency end of the modelled spectra, where large turbulent eddies dominate, there is some deviation in model accuracy, particularly during the ebb tide where recorded turbulence parameters are extremely variable,creating uncertainty due to a relatively small sample size. Between field and model velocity maxima, some scatter is observed, potentially providing uncertainty in the estimation of ultimate loads. Model and field damage equivalent velocities, used in the determination of fatigue loads, agree well. Results suggest that a linear wave-current representation of subsurface velocities at this particular tidal site is applicable. Care should be taken when interpreting this result due to the relatively small sample size, and the possibility of site specific nuances, and as such further studies are proposed.The Virtual DCP model is a novel development which has proven its usefulness in the work contained in this thesis and in the analysis of commercial field data. It is extremely versatile, adapting to a range of configurations and set up criteria such that it can be used in the quantification of DCP measurement error for a range of flow characteristics. This information is useful in the design of tidal turbines (and other sub-sea structures) as well as for oceanographic and biological processes. The tidal ow model developed extends beyond the capability of similar numerical models with the capability to model the interaction between waves and currents according to a number of different options. Combined with the VDCP, which samples from the model ow field, a system is created that can be effectively calibrated to find the best model solution to replicate flows at a tidal site measured by a 'real' DCP over a broad range of sea conditions and water depths. The purpose is to ensure that models used to predict the sub surface velocities in the field are suitable and a key question was to understand whether the linear super-position of linear wave models and a turbulent current flow provides a realistic model of the particle kinematics with a view to undertaking loads analysis of a tidal stream turbine. Comparisons of this kind have not previously been documented, and this thesis lays out the path to improved site characterisation and model validation, as well as drawing conclusions on useful methods for modelling flows impacted by waves.As developers seek to convert the energy of the tides into electricity, sub-sea turbines must be designed to perform well in increasingly harsh conditions. Such energetic seas have historically been avoided, hence measurements taken below the surface in strong tidal currents and large waves are relatively few, and the theory behind these interactions is underdeveloped. This thesis compares measurements of subsurface velocity taken in the field, at a UK site proposed for development, to the velocity outputs of a model capable of combining waves and currents in a number of ways. In particular the interaction between waves and currents is investigated.The methodology incorporates a novel virtual velocity measurement instrument to measure the model ow,replicating the physical instruments used at sea, such that direct comparisons can be made between the two data-sets. Model and field velocities show good agreement across a range of current speeds and wave heights,with a range of metrics used to demonstrate the suitability of the model, based on linear wave-current theory,for this site. The wave-current interaction module is calibrated, with linear superposition of wave and current velocities proving a suitable representation of field velocities. Calculation of a dispersion relationship affected by mean current velocity marginally improves calibration with field data. Analysis of other sites using the tools developed will further validate this type of model, which in combination with blade element momentum theory,is able to predict pre-construction site specific loads on tidal turbines.Doppler Current Profilers (DCPs) are able to measure subsurface water particle kinematics and sea surface elevation simultaneously, however assumptions made by these instruments jeopardise detail when recording in highly energetic seas, particularly where waves and turbulent tidal currents combine. Models developed to optimise the design of tidal turbines require correct site specific inputs to accurately reflect the conditions that a turbine may encounter through its lifetime, moreover, the kinematics of these models must be accurately validated. To overcome the limitations in DCP measurements a 'Virtual' Doppler Current Profiler (VDCP)is developed (Crossley et al. 2017), enabling quantification of error in site characteristics, and 'like for like'comparisons of field and model kinematics that has never previously been documented. The numerical model developed incorporates tidal currents, waves and turbulence combined linearly to output subsurface velocity based on conditions from the field which have been averaged over ten minute intervals. The inputs are simple,time averaged characteristics (current magnitude, direction, and profile; wave height, period and direction,turbulence intensity and turbulence length-scale) and the model outputs velocities over a two dimensional grid that develops with time. The VDCP samples this ow as if it were the very instrument in the field that recorded the data used for validation. Taking into account the heading, pitch and roll of the instrument a data set directly comparable to that measured in the field is generated.The VDCP is initially used in quantifying error in wave and turbulence statistics, demonstrating a phase dependency of velocity measurements averaged between beams and providing a theoretical error for wave and turbulence characteristics sampled under a range of conditions, in order to improve tidal site characterisation. Spectral moments of the subsurface longitudinal wave orbital velocities recorded by the VDCP can be between 0.1 and 9 times those measured at a point for certain turbulent current conditions, turbulence intensity measurements may vary between 0.2 and 1.5 times the input value in low wave conditions and turbulence length scale calculations can vary by over ten times the input value, dependent on both current and wave conditions.The methodology can be used to determine a theoretical error in any site characterisation parameter for any set of wave, current and turbulence conditions.Results of the model validation using the VDCP show that the tidal ow model, and in particular the newly developed wave-current interaction module, is effective in simulating field subsurface velocities over a range of depths, for waves of up to 3m significant wave height and currents of up to 3.5ms1.;The model is effective in reproducing the wave climate using both measured and modelled surface elevation spectra, and tests, with marginal improvements, the effect of modifying the dispersion equation to account for currents. Field and model velocities compare well over the frequency range dominated by waves, showing only small underestimations in model standard deviations with respect to those from field data, at depths close to the sea surface. At the low frequency end of the modelled spectra, where large turbulent eddies dominate, there is some deviation in model accuracy, particularly during the ebb tide where recorded turbulence parameters are extremely variable,creating uncertainty due to a relatively small sample size. Between field and model velocity maxima, some scatter is observed, potentially providing uncertainty in the estimation of ultimate loads. Model and field damage equivalent velocities, used in the determination of fatigue loads, agree well. Results suggest that a linear wave-current representation of subsurface velocities at this particular tidal site is applicable. Care should be taken when interpreting this result due to the relatively small sample size, and the possibility of site specific nuances, and as such further studies are proposed.The Virtual DCP model is a novel development which has proven its usefulness in the work contained in this thesis and in the analysis of commercial field data. It is extremely versatile, adapting to a range of configurations and set up criteria such that it can be used in the quantification of DCP measurement error for a range of flow characteristics. This information is useful in the design of tidal turbines (and other sub-sea structures) as well as for oceanographic and biological processes. The tidal ow model developed extends beyond the capability of similar numerical models with the capability to model the interaction between waves and currents according to a number of different options. Combined with the VDCP, which samples from the model ow field, a system is created that can be effectively calibrated to find the best model solution to replicate flows at a tidal site measured by a 'real' DCP over a broad range of sea conditions and water depths. The purpose is to ensure that models used to predict the sub surface velocities in the field are suitable and a key question was to understand whether the linear super-position of linear wave models and a turbulent current flow provides a realistic model of the particle kinematics with a view to undertaking loads analysis of a tidal stream turbine. Comparisons of this kind have not previously been documented, and this thesis lays out the path to improved site characterisation and model validation, as well as drawing conclusions on useful methods for modelling flows impacted by waves
Identifying children with characteristics of asperger syndrome in schools in Malacca, Malaysia : examining the range of characteristics of children with autism in the special education units
Get PDFThis study aims to identify children with characteristics of AS amongst children with a diagnosis of autism in special education units (SEUs) and mainstream classes in schools in Malacca, Malaysia, to examine the differences in the characteristics of children with a diagnosis of autism in the SEUs, to assess the usefulness of an information pack for parents and teachers, and to evaluate whether the identification process and the information pack for the SEUs teachers, has influenced their practice. This study was undertaken using a standardised rating scales for parents and teachers which was specifically formulated to identify individuals with AS. These findings were then compared to the children's scores in different tests (IQ, play, Theory of Mind, language and social communication) in which children with AS usually score higher and to GADS parent interview scores, which offer more information on the developmental history of each child. In the mainstream classes, the identification of children with characteristics of AS employed a screening test completed by class teachers for each child in their class. The findings indicated that it was difficult to differentiate children with characteristics of AS from children with autism. The findings also not supported the DSM-IV diagnostic criteria for AS 'no language and cognitive development delays'. Therefore it supported that autism is a spectrum and DSM 5 (2013) which has merged subtypes of autism into one umbrella diagnosis called ASD. It was also found that the social communication impairments and restricted, repetitive stereotyped patterns of behaviour could differentiate people with autism into three levels (requiring support, requiring substantial support and requiring very substantial support) as indicated in the DSM 5. The findings that children with autism have very uneven profiles with [sic] wide range of abilities indicated the importance of individualise support and focus on each child as unique.;Findings of this study should be interpreted with caution because of the small number of participants, limitation of the methodology and standardised instrument used in the study. The additional questions found that there are still lack of information regarding ASD for parents and teachers in Malaysian context. Therefore they really appreciated the information pack that have been given to them. Teachers indicated that they have [sic] higher level of understanding and expectation on children's potential learning and development after have [sic] more knowledge on ASD. It was found that there are a lot of similarities in the findings of this study when compared to research from other countries e.g. characteristics of children with ASD, estimated prevalence of children with AS and support for the new diagnostic criteria (DSM 5, 2013). Therefore more research, knowledge and awareness on children with ASD in [sic] Malaysian context could be developed from this study.This study aims to identify children with characteristics of AS amongst children with a diagnosis of autism in special education units (SEUs) and mainstream classes in schools in Malacca, Malaysia, to examine the differences in the characteristics of children with a diagnosis of autism in the SEUs, to assess the usefulness of an information pack for parents and teachers, and to evaluate whether the identification process and the information pack for the SEUs teachers, has influenced their practice. This study was undertaken using a standardised rating scales for parents and teachers which was specifically formulated to identify individuals with AS. These findings were then compared to the children's scores in different tests (IQ, play, Theory of Mind, language and social communication) in which children with AS usually score higher and to GADS parent interview scores, which offer more information on the developmental history of each child. In the mainstream classes, the identification of children with characteristics of AS employed a screening test completed by class teachers for each child in their class. The findings indicated that it was difficult to differentiate children with characteristics of AS from children with autism. The findings also not supported the DSM-IV diagnostic criteria for AS 'no language and cognitive development delays'. Therefore it supported that autism is a spectrum and DSM 5 (2013) which has merged subtypes of autism into one umbrella diagnosis called ASD. It was also found that the social communication impairments and restricted, repetitive stereotyped patterns of behaviour could differentiate people with autism into three levels (requiring support, requiring substantial support and requiring very substantial support) as indicated in the DSM 5. The findings that children with autism have very uneven profiles with [sic] wide range of abilities indicated the importance of individualise support and focus on each child as unique.;Findings of this study should be interpreted with caution because of the small number of participants, limitation of the methodology and standardised instrument used in the study. The additional questions found that there are still lack of information regarding ASD for parents and teachers in Malaysian context. Therefore they really appreciated the information pack that have been given to them. Teachers indicated that they have [sic] higher level of understanding and expectation on children's potential learning and development after have [sic] more knowledge on ASD. It was found that there are a lot of similarities in the findings of this study when compared to research from other countries e.g. characteristics of children with ASD, estimated prevalence of children with AS and support for the new diagnostic criteria (DSM 5, 2013). Therefore more research, knowledge and awareness on children with ASD in [sic] Malaysian context could be developed from this study
An analysis of trade unions in shaping favoured employment relations outcomes in the British Labour Party post-1970
Get PDFThough the contemporary political situation is unfavourable, there has been a continuing and lively debate about the efficacy of trade union affiliation to the Labour Party. This debate has primarily focused upon if trade unions are an effective mechanism for political action due to their institutional role and leverage inside the party's structures.In order to evaluate the extent of this influence, the thesis examines four legislative events, which chart the transition from two structurally different contexts - collective laissez-faireism to a liberal market economy. These events are the Social Contract (1974-79), National Minimum Wage (1998), Employment Relations Act (1999) and the Warwick Agreement (2004). The thesis uses Hamann and Kelly's (2004) four factors of influence that shape trade union decision-making as a conceptual framework: (1) economic and political institutions (2) union ideology, (3) employer, political party or state strategies and (4) strategic choices of union leaders. The research established three questions framed as propositions designed to identify structural and agency factors flowing from these four factors.Utilising this framework, the thesis will present an analysis of the constraining and optimising effects of the four factors on the ability of trade unions to attain favoured outcomes. The research found the strategic choices of union leaders to be the most important factor contributing to minimalist and more extensive employment relations frameworks. Informal processes are judged to have displaced formal processes in conjunction with coordination mechanisms as a means to offsetting environmental constraints.The thesis' observations are anchored through a unique dataset consisting of in-depth interviews from the reflections of actors who strategically influenced the behaviour of trade unions or directly engaged trade union leaders in the legislative events. The object of enquiry, that being political action by trade unions as a mechanism for delivering change, is better understood from the strategic perspective of these actors. As such, a distinctive feature of the research is its approach to case events and sources of data.Though the contemporary political situation is unfavourable, there has been a continuing and lively debate about the efficacy of trade union affiliation to the Labour Party. This debate has primarily focused upon if trade unions are an effective mechanism for political action due to their institutional role and leverage inside the party's structures.In order to evaluate the extent of this influence, the thesis examines four legislative events, which chart the transition from two structurally different contexts - collective laissez-faireism to a liberal market economy. These events are the Social Contract (1974-79), National Minimum Wage (1998), Employment Relations Act (1999) and the Warwick Agreement (2004). The thesis uses Hamann and Kelly's (2004) four factors of influence that shape trade union decision-making as a conceptual framework: (1) economic and political institutions (2) union ideology, (3) employer, political party or state strategies and (4) strategic choices of union leaders. The research established three questions framed as propositions designed to identify structural and agency factors flowing from these four factors.Utilising this framework, the thesis will present an analysis of the constraining and optimising effects of the four factors on the ability of trade unions to attain favoured outcomes. The research found the strategic choices of union leaders to be the most important factor contributing to minimalist and more extensive employment relations frameworks. Informal processes are judged to have displaced formal processes in conjunction with coordination mechanisms as a means to offsetting environmental constraints.The thesis' observations are anchored through a unique dataset consisting of in-depth interviews from the reflections of actors who strategically influenced the behaviour of trade unions or directly engaged trade union leaders in the legislative events. The object of enquiry, that being political action by trade unions as a mechanism for delivering change, is better understood from the strategic perspective of these actors. As such, a distinctive feature of the research is its approach to case events and sources of data
A generic evaluation of loads in horizontal axis wind turbines
Get PDFThousands of load calculations for wind turbine design have been calculated by manufactures, consultants and certification bodies. These have been done as required to develop and validate specific designs. However, there has not been a general systematic study of trends in loads related to key wind turbine design parameters and external operating conditions. The aim of this thesis is parameterise and quantify trends of extreme and fatigue loads based on systematic modifications of wind turbine characteristics.;This thesis is in two main parts. The first part provides an overview of loads calculation methods, flow modelling and approach adopted also considering scaling rules, comparing scaling with similarity and the scaling evident in from commercial world turbines data.;The second part presents and evaluates loading trends for extreme and fatigue loads related to systematic alterations of key wind turbine parameters. Three chapters of results investigate the load impacts of blade structural properties, rotor solidity and up-scaling respectively. The chapter on blade structural properties demonstrates that the self-weight of blades is a major component influencing loads of the blade root and hub.;The chapter on rotor solidity shows that significant load reduction can result for blade root, shaft and yaw bearing in reducing the solidity of rotor. However, the aerodynamic damping reduces with reducing solidity, which is crucial for tower base fore-aft loads; therefore the reducing rotor solidity has an adverse impact on the tower base fore-aft loads. The chapter on up-scale demonstrates that up-scaling with similarity method can give good prediction of loads with an error of ±10% and ±15% for extreme and fatigue loads of large wind turbines (up to 10MW) at the mean wind speed within power production range. Additional, the chapter of up-scaling showed that the up-scaled wind turbines reduce the sensitivity to turbulence with the size of rotor.Thousands of load calculations for wind turbine design have been calculated by manufactures, consultants and certification bodies. These have been done as required to develop and validate specific designs. However, there has not been a general systematic study of trends in loads related to key wind turbine design parameters and external operating conditions. The aim of this thesis is parameterise and quantify trends of extreme and fatigue loads based on systematic modifications of wind turbine characteristics.;This thesis is in two main parts. The first part provides an overview of loads calculation methods, flow modelling and approach adopted also considering scaling rules, comparing scaling with similarity and the scaling evident in from commercial world turbines data.;The second part presents and evaluates loading trends for extreme and fatigue loads related to systematic alterations of key wind turbine parameters. Three chapters of results investigate the load impacts of blade structural properties, rotor solidity and up-scaling respectively. The chapter on blade structural properties demonstrates that the self-weight of blades is a major component influencing loads of the blade root and hub.;The chapter on rotor solidity shows that significant load reduction can result for blade root, shaft and yaw bearing in reducing the solidity of rotor. However, the aerodynamic damping reduces with reducing solidity, which is crucial for tower base fore-aft loads; therefore the reducing rotor solidity has an adverse impact on the tower base fore-aft loads. The chapter on up-scale demonstrates that up-scaling with similarity method can give good prediction of loads with an error of ±10% and ±15% for extreme and fatigue loads of large wind turbines (up to 10MW) at the mean wind speed within power production range. Additional, the chapter of up-scaling showed that the up-scaled wind turbines reduce the sensitivity to turbulence with the size of rotor
Textural and structural characteristics of the Kestanelik epithermal vein system, NW Turkey : implications for permeability enhancement mechanisms and gold exploration in epithermal systems
Get PDFIt has long been known that faults and fracture provide a critical role in multiphase epithermal mineralization, however the mechanisms of permeability enhancement after a conduit becomes sealed up over time has been less well studied. The research in this thesis investigates the vein-scale permeability enhancement mechanisms in epithermal gold deposits through a detailed study of geology, dimensions, geometry, textures and breccias of the well-exposed Kestanelik gold deposit (NW Turkey). New mapping of the deposit and its host rocks show that the Late Eocene mineralization is associated with regional Cenozoic calc-alkaline magmatism. Vein textures and breccia components indicate repeated sealing and subsequent brecciation of wall rock and pre-existing vein infill. Kinematic analyses together with macroscopic and petrographic analyses of vein textures characterize E-W trending veins as left lateral faults, whilst NE-SW trending veins are extensional (Mode I) fractures. Although two phases of mineralization were picked up from E-W trending veins, at least three were determined from NE-SW trending veins. Cataclasite and tectonic breccia of wall rocks and early quartz, hydrothermal crackle breccias, and cement supported chaotic breccias of pre-existing vein infill, all of which are cemented by late-stage quartz, indicate that coseismic rupturing and hydraulic fracturing are two major permeability enhancement mechanisms. Faults were reactivated along the vein footwall-wall rock contact, while extensional veins were opened along their either margin. Transient local stress variation also has the potential to enhance permeability on mis-oriented surfaces and at locations where the dip changes. Constructed 3D vein geometries show subsurface vein bends are more favorable structural locations for gold to precipitate than smooth, planar segments, and the host rock schist host the majority of gold. This study emphasizes the importance of detailed structural and textural studies for gold exploration and 3D orebody modelling.It has long been known that faults and fracture provide a critical role in multiphase epithermal mineralization, however the mechanisms of permeability enhancement after a conduit becomes sealed up over time has been less well studied. The research in this thesis investigates the vein-scale permeability enhancement mechanisms in epithermal gold deposits through a detailed study of geology, dimensions, geometry, textures and breccias of the well-exposed Kestanelik gold deposit (NW Turkey). New mapping of the deposit and its host rocks show that the Late Eocene mineralization is associated with regional Cenozoic calc-alkaline magmatism. Vein textures and breccia components indicate repeated sealing and subsequent brecciation of wall rock and pre-existing vein infill. Kinematic analyses together with macroscopic and petrographic analyses of vein textures characterize E-W trending veins as left lateral faults, whilst NE-SW trending veins are extensional (Mode I) fractures. Although two phases of mineralization were picked up from E-W trending veins, at least three were determined from NE-SW trending veins. Cataclasite and tectonic breccia of wall rocks and early quartz, hydrothermal crackle breccias, and cement supported chaotic breccias of pre-existing vein infill, all of which are cemented by late-stage quartz, indicate that coseismic rupturing and hydraulic fracturing are two major permeability enhancement mechanisms. Faults were reactivated along the vein footwall-wall rock contact, while extensional veins were opened along their either margin. Transient local stress variation also has the potential to enhance permeability on mis-oriented surfaces and at locations where the dip changes. Constructed 3D vein geometries show subsurface vein bends are more favorable structural locations for gold to precipitate than smooth, planar segments, and the host rock schist host the majority of gold. This study emphasizes the importance of detailed structural and textural studies for gold exploration and 3D orebody modelling
An approach for the development and implementation of systems in complex business contexts through methodology tailoring
Get PDFSystems utilised in complex business contexts commonly need to be well integrated within the business in which they operate. There is a risk of poor acceptance, adoption, and sustainment in the business if the system does not take into account key business related considerations. Utilising DePuy Orthopaedics resource management business context as a case study, an assessment of potential System Development Methodologies (SDM) that could be utilised in the development of an IT system was carried out. It was established that no single SDM could provide the level of support that was identified as required. Further investigation of system development within complex businesses ascertained that methodology tailoring is an approach utilised to ensure that methodologies incorporate business specific complexities with a subsequent aim to ensure that developed systems are fit for purpose. However, there is little proven procedural guidance that illustrates an approach towards SDM tailoring in the complex business environment of resource management for New Product Development at DePuy. There was, therefore a gap in research and an identified need for an approach that provides the appropriate level of support for SDM tailoring for the development of systems in this complex business context.Utilising the knowledge gathered within DePuy Orthopaedics, as well as from literature in the field, methods for managing business related complexities in system development were established, developed, and formalised into an approach that addressed the tailoring of SDMs. The approach was influenced by the critical evaluation of DePuy's complex business context which aided in the creating and application of the approach.The approach was validated through its application in a business context, where it was used to develop a tailored methodology for use in developing and implementing a resource management IT system at a portfolio level. The validation proved the approach was legitimate and produced a methodology and subsequent system which were readily adopted and accepted by the company. Furthermore, the tailored methodology was evaluated by industrially based engineers with experience of systems development in a complex business context, resource management and systems engineering. From this evaluation, it was established that the tailored methodology was sound and can be said to be valid in the context that it was developed.Systems utilised in complex business contexts commonly need to be well integrated within the business in which they operate. There is a risk of poor acceptance, adoption, and sustainment in the business if the system does not take into account key business related considerations. Utilising DePuy Orthopaedics resource management business context as a case study, an assessment of potential System Development Methodologies (SDM) that could be utilised in the development of an IT system was carried out. It was established that no single SDM could provide the level of support that was identified as required. Further investigation of system development within complex businesses ascertained that methodology tailoring is an approach utilised to ensure that methodologies incorporate business specific complexities with a subsequent aim to ensure that developed systems are fit for purpose. However, there is little proven procedural guidance that illustrates an approach towards SDM tailoring in the complex business environment of resource management for New Product Development at DePuy. There was, therefore a gap in research and an identified need for an approach that provides the appropriate level of support for SDM tailoring for the development of systems in this complex business context.Utilising the knowledge gathered within DePuy Orthopaedics, as well as from literature in the field, methods for managing business related complexities in system development were established, developed, and formalised into an approach that addressed the tailoring of SDMs. The approach was influenced by the critical evaluation of DePuy's complex business context which aided in the creating and application of the approach.The approach was validated through its application in a business context, where it was used to develop a tailored methodology for use in developing and implementing a resource management IT system at a portfolio level. The validation proved the approach was legitimate and produced a methodology and subsequent system which were readily adopted and accepted by the company. Furthermore, the tailored methodology was evaluated by industrially based engineers with experience of systems development in a complex business context, resource management and systems engineering. From this evaluation, it was established that the tailored methodology was sound and can be said to be valid in the context that it was developed
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